Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

287 files changed, 23514 insertions, 0 deletions

diff --git a/third_party/rust/pin-project-internal/.cargo-checksum.json b/third_party/rust/pin-project-internal/.cargo-checksum.json
new file mode 100644
index 0000000000..db974b518b
--- /dev/null
+++ b/third_party/rust/pin-project-internal/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"ae1169ef7f2dc32d4b461732284ad5d66019fd3d2a5897254c240759b61e675d","LICENSE-APACHE":"0d542e0c8804e39aa7f37eb00da5a762149dc682d7829451287e11b938e94594","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","src/lib.rs":"3c1b4ae774d0c05d74997e5f88fe43d95162df14f5eaf6ebbf03ca92b2ebdf7d","src/pin_project/args.rs":"903be7b22a2eda4ed59d890feb75bd4c98e243b4faaa809aff0621d15cd06431","src/pin_project/attribute.rs":"3e392493e875f0c935525579ba9bd888d8e00b57b3d6594b7fde040c31790784","src/pin_project/derive.rs":"0060e78285d89f5807126eb7f3d8a721dd4592a9e070ca0cda2f6cf2bf34e27b","src/pin_project/mod.rs":"83e6fc982a8c136811332512abc7d368e5d09b94f245de5d19490f835e85943a","src/pinned_drop.rs":"f3d386e00ce2fe25fc817ac57f07569f9e43a519e12d977db39f4c239be4dcf4","src/utils.rs":"24372d39be74fb9b6728bca08d74ed0a8ed7915de97ada6b20ebb6243ae6eed0"},"package":"069bdb1e05adc7a8990dce9cc75370895fbe4e3d58b9b73bf1aee56359344a55"}
\ No newline at end of file
diff --git a/third_party/rust/pin-project-internal/Cargo.toml b/third_party/rust/pin-project-internal/Cargo.toml
new file mode 100644
index 0000000000..b2f5450923
--- /dev/null
+++ b/third_party/rust/pin-project-internal/Cargo.toml
@@ -0,0 +1,51 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+rust-version = "1.37"
+name = "pin-project-internal"
+version = "1.0.12"
+description = """
+Implementation detail of the `pin-project` crate.
+"""
+keywords = [
+    "pin",
+    "macros",
+    "attribute",
+]
+categories = [
+    "no-std",
+    "rust-patterns",
+]
+license = "Apache-2.0 OR MIT"
+repository = "https://github.com/taiki-e/pin-project"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[lib]
+proc-macro = true
+
+[dependencies.proc-macro2]
+version = "1"
+
+[dependencies.quote]
+version = "1"
+
+[dependencies.syn]
+version = "1.0.56"
+features = [
+    "full",
+    "visit-mut",
+]
+
+[dev-dependencies]
diff --git a/third_party/rust/pin-project-internal/LICENSE-APACHE b/third_party/rust/pin-project-internal/LICENSE-APACHE
new file mode 100644
index 0000000000..f433b1a53f
--- /dev/null
+++ b/third_party/rust/pin-project-internal/LICENSE-APACHE
@@ -0,0 +1,177 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
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+      of your accepting any such warranty or additional liability.
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+   END OF TERMS AND CONDITIONS
diff --git a/third_party/rust/pin-project-internal/LICENSE-MIT b/third_party/rust/pin-project-internal/LICENSE-MIT
new file mode 100644
index 0000000000..31aa79387f
--- /dev/null
+++ b/third_party/rust/pin-project-internal/LICENSE-MIT
@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/pin-project-internal/src/lib.rs b/third_party/rust/pin-project-internal/src/lib.rs
new file mode 100644
index 0000000000..07683c417e
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/lib.rs
@@ -0,0 +1,584 @@
+//! Implementation detail of the `pin-project` crate. - **do not use directly**
+
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_variables)
+    )
+))]
+#![forbid(unsafe_code)]
+#![warn(rust_2018_idioms, single_use_lifetimes, unreachable_pub)]
+#![warn(clippy::pedantic)]
+#![allow(
+    clippy::needless_doctest_main,
+    clippy::similar_names,
+    clippy::single_match_else,
+    clippy::too_many_lines,
+    clippy::unnested_or_patterns
+)]
+
+// older compilers require explicit `extern crate`.
+#[allow(unused_extern_crates)]
+extern crate proc_macro;
+
+#[macro_use]
+mod utils;
+
+mod pin_project;
+mod pinned_drop;
+
+use proc_macro::TokenStream;
+
+/// An attribute that creates projection types covering all the fields of
+/// struct or enum.
+///
+/// This attribute creates projection types according to the following rules:
+///
+/// - For the fields that use `#[pin]` attribute, create the pinned reference to
+///   the field.
+/// - For the other fields, create a normal reference to the field.
+///
+/// And the following methods are implemented on the original type:
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// # type Projection<'a> = &'a ();
+/// # type ProjectionRef<'a> = &'a ();
+/// # trait Dox {
+/// fn project(self: Pin<&mut Self>) -> Projection<'_>;
+/// fn project_ref(self: Pin<&Self>) -> ProjectionRef<'_>;
+/// # }
+/// ```
+///
+/// By passing an argument with the same name as the method to the attribute,
+/// you can name the projection type returned from the method. This allows you
+/// to use pattern matching on the projected types.
+///
+/// ```rust
+/// # use pin_project::pin_project;
+/// # use std::pin::Pin;
+/// #[pin_project(project = EnumProj)]
+/// enum Enum<T> {
+///     Variant(#[pin] T),
+/// }
+///
+/// impl<T> Enum<T> {
+///     fn method(self: Pin<&mut Self>) {
+///         let this: EnumProj<'_, T> = self.project();
+///         match this {
+///             EnumProj::Variant(x) => {
+///                 let _: Pin<&mut T> = x;
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// Note that the projection types returned by `project` and `project_ref` have
+/// an additional lifetime at the beginning of generics.
+///
+/// ```text
+/// let this: EnumProj<'_, T> = self.project();
+///                    ^^
+/// ```
+///
+/// The visibility of the projected types and projection methods is based on the
+/// original type. However, if the visibility of the original type is `pub`, the
+/// visibility of the projected types and the projection methods is downgraded
+/// to `pub(crate)`.
+///
+/// # Safety
+///
+/// This attribute is completely safe. In the absence of other `unsafe` code
+/// *that you write*, it is impossible to cause [undefined
+/// behavior][undefined-behavior] with this attribute.
+///
+/// This is accomplished by enforcing the four requirements for pin projection
+/// stated in [the Rust documentation][pin-projection]:
+///
+/// 1. The struct must only be [`Unpin`] if all the structural fields are
+///    [`Unpin`].
+///
+///    To enforce this, this attribute will automatically generate an [`Unpin`]
+///    implementation for you, which will require that all structurally pinned
+///    fields be [`Unpin`].
+///
+///    If you attempt to provide an [`Unpin`] impl, the blanket impl will then
+///    apply to your type, causing a compile-time error due to the conflict with
+///    the second impl.
+///
+///    If you wish to provide a manual [`Unpin`] impl, you can do so via the
+///    [`UnsafeUnpin`][unsafe-unpin] argument.
+///
+/// 2. The destructor of the struct must not move structural fields out of its
+///    argument.
+///
+///    To enforce this, this attribute will generate code like this:
+///
+///    ```rust
+///    struct MyStruct {}
+///    trait MyStructMustNotImplDrop {}
+///    # #[allow(unknown_lints, drop_bounds)]
+///    impl<T: Drop> MyStructMustNotImplDrop for T {}
+///    impl MyStructMustNotImplDrop for MyStruct {}
+///    ```
+///
+///    If you attempt to provide an [`Drop`] impl, the blanket impl will then
+///    apply to your type, causing a compile-time error due to the conflict with
+///    the second impl.
+///
+///    If you wish to provide a custom [`Drop`] impl, you can annotate an impl
+///    with [`#[pinned_drop]`][pinned-drop]. This impl takes a pinned version of
+///    your struct - that is, [`Pin`]`<&mut MyStruct>` where `MyStruct` is the
+///    type of your struct.
+///
+///    You can call `.project()` on this type as usual, along with any other
+///    methods you have defined. Because your code is never provided with
+///    a `&mut MyStruct`, it is impossible to move out of pin-projectable
+///    fields in safe code in your destructor.
+///
+/// 3. You must make sure that you uphold the [`Drop`
+///    guarantee][drop-guarantee]: once your struct is pinned, the memory that
+///    contains the content is not overwritten or deallocated without calling
+///    the content's destructors.
+///
+///    Safe code doesn't need to worry about this - the only way to violate
+///    this requirement is to manually deallocate memory (which is `unsafe`),
+///    or to overwrite a field with something else.
+///    Because your custom destructor takes [`Pin`]`<&mut MyStruct>`, it's
+///    impossible to obtain a mutable reference to a pin-projected field in safe
+///    code.
+///
+/// 4. You must not offer any other operations that could lead to data being
+///    moved out of the structural fields when your type is pinned.
+///
+///    As with requirement 3, it is impossible for safe code to violate this.
+///    This crate ensures that safe code can never obtain a mutable reference to
+///    `#[pin]` fields, which prevents you from ever moving out of them in safe
+///    code.
+///
+/// Pin projections are also incompatible with [`#[repr(packed)]`][repr-packed]
+/// types. Attempting to use this attribute on a `#[repr(packed)]` type results
+/// in a compile-time error.
+///
+/// # Examples
+///
+/// `#[pin_project]` can be used on structs and enums.
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project]
+/// struct Struct<T, U> {
+///     #[pin]
+///     pinned: T,
+///     unpinned: U,
+/// }
+///
+/// impl<T, U> Struct<T, U> {
+///     fn method(self: Pin<&mut Self>) {
+///         let this = self.project();
+///         let _: Pin<&mut T> = this.pinned;
+///         let _: &mut U = this.unpinned;
+///     }
+/// }
+/// ```
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project]
+/// struct TupleStruct<T, U>(#[pin] T, U);
+///
+/// impl<T, U> TupleStruct<T, U> {
+///     fn method(self: Pin<&mut Self>) {
+///         let this = self.project();
+///         let _: Pin<&mut T> = this.0;
+///         let _: &mut U = this.1;
+///     }
+/// }
+/// ```
+///
+/// To use `#[pin_project]` on enums, you need to name the projection type
+/// returned from the method.
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project(project = EnumProj)]
+/// enum Enum<T, U> {
+///     Tuple(#[pin] T),
+///     Struct { field: U },
+///     Unit,
+/// }
+///
+/// impl<T, U> Enum<T, U> {
+///     fn method(self: Pin<&mut Self>) {
+///         match self.project() {
+///             EnumProj::Tuple(x) => {
+///                 let _: Pin<&mut T> = x;
+///             }
+///             EnumProj::Struct { field } => {
+///                 let _: &mut U = field;
+///             }
+///             EnumProj::Unit => {}
+///         }
+///     }
+/// }
+/// ```
+///
+/// When `#[pin_project]` is used on enums, only named projection types and
+/// methods are generated because there is no way to access variants of
+/// projected types without naming it.
+/// For example, in the above example, only the `project` method is generated,
+/// and the `project_ref` method is not generated.
+/// (When `#[pin_project]` is used on structs, both methods are always generated.)
+///
+/// ```rust,compile_fail,E0599
+/// # use pin_project::pin_project;
+/// # use std::pin::Pin;
+/// #
+/// # #[pin_project(project = EnumProj)]
+/// # enum Enum<T, U> {
+/// #     Tuple(#[pin] T),
+/// #     Struct { field: U },
+/// #     Unit,
+/// # }
+/// #
+/// impl<T, U> Enum<T, U> {
+///     fn call_project_ref(self: Pin<&Self>) {
+///         let _this = self.project_ref();
+///         //~^ ERROR no method named `project_ref` found for struct `Pin<&Enum<T, U>>` in the current scope
+///     }
+/// }
+/// ```
+///
+/// If you want to call `.project()` multiple times or later use the
+/// original [`Pin`] type, it needs to use [`.as_mut()`][`Pin::as_mut`] to avoid
+/// consuming the [`Pin`].
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project]
+/// struct Struct<T> {
+///     #[pin]
+///     field: T,
+/// }
+///
+/// impl<T> Struct<T> {
+///     fn call_project_twice(mut self: Pin<&mut Self>) {
+///         // `project` consumes `self`, so reborrow the `Pin<&mut Self>` via `as_mut`.
+///         self.as_mut().project();
+///         self.as_mut().project();
+///     }
+/// }
+/// ```
+///
+/// # `!Unpin`
+///
+/// If you want to ensure that [`Unpin`] is not implemented, use the `!Unpin`
+/// argument to `#[pin_project]`.
+///
+/// ```rust
+/// use pin_project::pin_project;
+///
+/// #[pin_project(!Unpin)]
+/// struct Struct<T> {
+///     field: T,
+/// }
+/// ```
+///
+/// This is equivalent to using `#[pin]` attribute for the [`PhantomPinned`]
+/// field.
+///
+/// ```rust
+/// use std::marker::PhantomPinned;
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project]
+/// struct Struct<T> {
+///     field: T,
+///     #[pin] // <------ This `#[pin]` is required to make `Struct` to `!Unpin`.
+///     _pin: PhantomPinned,
+/// }
+/// ```
+///
+/// Note that using [`PhantomPinned`] without `#[pin]` attribute has no effect.
+///
+/// # `UnsafeUnpin`
+///
+/// If you want to implement [`Unpin`] manually, you must use the `UnsafeUnpin`
+/// argument to `#[pin_project]`.
+///
+/// ```rust
+/// use pin_project::{pin_project, UnsafeUnpin};
+///
+/// #[pin_project(UnsafeUnpin)]
+/// struct Struct<T, U> {
+///     #[pin]
+///     pinned: T,
+///     unpinned: U,
+/// }
+///
+/// unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+/// ```
+///
+/// Note the usage of the unsafe [`UnsafeUnpin`] trait, instead of the usual
+/// [`Unpin`] trait. [`UnsafeUnpin`] behaves exactly like [`Unpin`], except that
+/// is unsafe to implement. This unsafety comes from the fact that pin
+/// projections are being used. If you implement [`UnsafeUnpin`], you must
+/// ensure that it is only implemented when all pin-projected fields implement
+/// [`Unpin`].
+///
+/// See [`UnsafeUnpin`] trait for more details.
+///
+/// # `#[pinned_drop]`
+///
+/// In order to correctly implement pin projections, a type's [`Drop`] impl must
+/// not move out of any structurally pinned fields. Unfortunately,
+/// [`Drop::drop`] takes `&mut Self`, not [`Pin`]`<&mut Self>`.
+///
+/// To ensure that this requirement is upheld, the `#[pin_project]` attribute
+/// will provide a [`Drop`] impl for you. This [`Drop`] impl will delegate to
+/// an impl block annotated with `#[pinned_drop]` if you use the `PinnedDrop`
+/// argument to `#[pin_project]`.
+///
+/// This impl block acts just like a normal [`Drop`] impl,
+/// except for the following two:
+///
+/// - `drop` method takes [`Pin`]`<&mut Self>`
+/// - Name of the trait is `PinnedDrop`.
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// pub trait PinnedDrop {
+///     fn drop(self: Pin<&mut Self>);
+/// }
+/// ```
+///
+/// `#[pin_project]` implements the actual [`Drop`] trait via `PinnedDrop` you
+/// implemented. To drop a type that implements `PinnedDrop`, use the [`drop`]
+/// function just like dropping a type that directly implements [`Drop`].
+///
+/// In particular, it will never be called more than once, just like
+/// [`Drop::drop`].
+///
+/// For example:
+///
+/// ```rust
+/// use std::{fmt::Debug, pin::Pin};
+///
+/// use pin_project::{pin_project, pinned_drop};
+///
+/// #[pin_project(PinnedDrop)]
+/// struct PrintOnDrop<T: Debug, U: Debug> {
+///     #[pin]
+///     pinned_field: T,
+///     unpin_field: U,
+/// }
+///
+/// #[pinned_drop]
+/// impl<T: Debug, U: Debug> PinnedDrop for PrintOnDrop<T, U> {
+///     fn drop(self: Pin<&mut Self>) {
+///         println!("Dropping pinned field: {:?}", self.pinned_field);
+///         println!("Dropping unpin field: {:?}", self.unpin_field);
+///     }
+/// }
+///
+/// fn main() {
+///     let _x = PrintOnDrop { pinned_field: true, unpin_field: 40 };
+/// }
+/// ```
+///
+/// See also [`#[pinned_drop]`][macro@pinned_drop] attribute.
+///
+/// # `project_replace` method
+///
+/// In addition to the `project` and `project_ref` methods which are always
+/// provided when you use the `#[pin_project]` attribute, there is a third
+/// method, `project_replace` which can be useful in some situations. It is
+/// equivalent to [`Pin::set`], except that the unpinned fields are moved and
+/// returned, instead of being dropped in-place.
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// # type ProjectionOwned = ();
+/// # trait Dox {
+/// fn project_replace(self: Pin<&mut Self>, other: Self) -> ProjectionOwned;
+/// # }
+/// ```
+///
+/// The `ProjectionOwned` type is identical to the `Self` type, except that
+/// all pinned fields have been replaced by equivalent [`PhantomData`] types.
+///
+/// This method is opt-in, because it is only supported for [`Sized`] types, and
+/// because it is incompatible with the [`#[pinned_drop]`][pinned-drop]
+/// attribute described above. It can be enabled by using
+/// `#[pin_project(project_replace)]`.
+///
+/// For example:
+///
+/// ```rust
+/// use std::{marker::PhantomData, pin::Pin};
+///
+/// use pin_project::pin_project;
+///
+/// #[pin_project(project_replace)]
+/// struct Struct<T, U> {
+///     #[pin]
+///     pinned_field: T,
+///     unpinned_field: U,
+/// }
+///
+/// impl<T, U> Struct<T, U> {
+///     fn method(self: Pin<&mut Self>, other: Self) {
+///         let this = self.project_replace(other);
+///         let _: U = this.unpinned_field;
+///         let _: PhantomData<T> = this.pinned_field;
+///     }
+/// }
+/// ```
+///
+/// By passing the value to the `project_replace` argument, you can name the
+/// returned type of the `project_replace` method. This is necessary whenever
+/// destructuring the return type of the `project_replace` method, and work in exactly
+/// the same way as the `project` and `project_ref` arguments.
+///
+/// ```rust
+/// use pin_project::pin_project;
+///
+/// #[pin_project(project_replace = EnumProjOwn)]
+/// enum Enum<T, U> {
+///     A {
+///         #[pin]
+///         pinned_field: T,
+///         unpinned_field: U,
+///     },
+///     B,
+/// }
+///
+/// let mut x = Box::pin(Enum::A { pinned_field: 42, unpinned_field: "hello" });
+///
+/// match x.as_mut().project_replace(Enum::B) {
+///     EnumProjOwn::A { unpinned_field, .. } => assert_eq!(unpinned_field, "hello"),
+///     EnumProjOwn::B => unreachable!(),
+/// }
+/// ```
+///
+/// [`PhantomData`]: core::marker::PhantomData
+/// [`PhantomPinned`]: core::marker::PhantomPinned
+/// [`Pin::as_mut`]: core::pin::Pin::as_mut
+/// [`Pin::set`]: core::pin::Pin::set
+/// [`Pin`]: core::pin::Pin
+/// [`UnsafeUnpin`]: https://docs.rs/pin-project/1/pin_project/trait.UnsafeUnpin.html
+/// [drop-guarantee]: core::pin#drop-guarantee
+/// [pin-projection]: core::pin#projections-and-structural-pinning
+/// [pinned-drop]: macro@pin_project#pinned_drop
+/// [repr-packed]: https://doc.rust-lang.org/nomicon/other-reprs.html#reprpacked
+/// [undefined-behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
+/// [unsafe-unpin]: macro@pin_project#unsafeunpin
+#[proc_macro_attribute]
+pub fn pin_project(args: TokenStream, input: TokenStream) -> TokenStream {
+    pin_project::attribute(&args.into(), input.into()).into()
+}
+
+/// An attribute used for custom implementations of [`Drop`].
+///
+/// This attribute is used in conjunction with the `PinnedDrop` argument to
+/// the [`#[pin_project]`][macro@pin_project] attribute.
+///
+/// The impl block annotated with this attribute acts just like a normal
+/// [`Drop`] impl, except for the following two:
+///
+/// - `drop` method takes [`Pin`]`<&mut Self>`
+/// - Name of the trait is `PinnedDrop`.
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// pub trait PinnedDrop {
+///     fn drop(self: Pin<&mut Self>);
+/// }
+/// ```
+///
+/// `#[pin_project]` implements the actual [`Drop`] trait via `PinnedDrop` you
+/// implemented. To drop a type that implements `PinnedDrop`, use the [`drop`]
+/// function just like dropping a type that directly implements [`Drop`].
+///
+/// In particular, it will never be called more than once, just like
+/// [`Drop::drop`].
+///
+/// # Examples
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project::{pin_project, pinned_drop};
+///
+/// #[pin_project(PinnedDrop)]
+/// struct PrintOnDrop {
+///     #[pin]
+///     field: u8,
+/// }
+///
+/// #[pinned_drop]
+/// impl PinnedDrop for PrintOnDrop {
+///     fn drop(self: Pin<&mut Self>) {
+///         println!("Dropping: {}", self.field);
+///     }
+/// }
+///
+/// fn main() {
+///     let _x = PrintOnDrop { field: 50 };
+/// }
+/// ```
+///
+/// See also ["pinned-drop" section of `#[pin_project]` attribute][pinned-drop].
+///
+/// # Why `#[pinned_drop]` attribute is needed?
+///
+/// Implementing `PinnedDrop::drop` is safe, but calling it is not safe.
+/// This is because destructors can be called multiple times in safe code and
+/// [double dropping is unsound][rust-lang/rust#62360].
+///
+/// Ideally, it would be desirable to be able to forbid manual calls in
+/// the same way as [`Drop::drop`], but the library cannot do it. So, by using
+/// macros and replacing them with private traits like the following,
+/// this crate prevent users from calling `PinnedDrop::drop` in safe code.
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// pub trait PinnedDrop {
+///     unsafe fn drop(self: Pin<&mut Self>);
+/// }
+/// ```
+///
+/// This allows implementing [`Drop`] safely using `#[pinned_drop]`.
+/// Also by using the [`drop`] function just like dropping a type that directly
+/// implements [`Drop`], can drop safely a type that implements `PinnedDrop`.
+///
+/// [rust-lang/rust#62360]: https://github.com/rust-lang/rust/pull/62360
+/// [`Pin`]: core::pin::Pin
+/// [pinned-drop]: macro@pin_project#pinned_drop
+#[proc_macro_attribute]
+pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
+    let input = syn::parse_macro_input!(input);
+    pinned_drop::attribute(&args.into(), input).into()
+}
+
+// Not public API.
+#[doc(hidden)]
+#[proc_macro_derive(__PinProjectInternalDerive, attributes(pin))]
+pub fn __pin_project_internal_derive(input: TokenStream) -> TokenStream {
+    pin_project::derive(input.into()).into()
+}
diff --git a/third_party/rust/pin-project-internal/src/pin_project/args.rs b/third_party/rust/pin-project-internal/src/pin_project/args.rs
new file mode 100644
index 0000000000..d0d4f362f5
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/pin_project/args.rs
@@ -0,0 +1,254 @@
+use proc_macro2::{Span, TokenStream};
+use quote::quote;
+use syn::{
+    parse::{Parse, ParseStream},
+    spanned::Spanned,
+    Attribute, Error, Ident, Result, Token,
+};
+
+use super::PIN;
+use crate::utils::{ParseBufferExt, SliceExt};
+
+pub(super) fn parse_args(attrs: &[Attribute]) -> Result<Args> {
+    // `(__private(<args>))` -> `<args>`
+    struct Input(Option<TokenStream>);
+
+    impl Parse for Input {
+        fn parse(input: ParseStream<'_>) -> Result<Self> {
+            Ok(Self((|| {
+                let content = input.parenthesized().ok()?;
+                let private = content.parse::<Ident>().ok()?;
+                if private == "__private" {
+                    content.parenthesized().ok()?.parse::<TokenStream>().ok()
+                } else {
+                    None
+                }
+            })()))
+        }
+    }
+
+    if let Some(attr) = attrs.find("pin_project") {
+        bail!(attr, "duplicate #[pin_project] attribute");
+    }
+
+    let mut attrs = attrs.iter().filter(|attr| attr.path.is_ident(PIN));
+
+    let prev = if let Some(attr) = attrs.next() {
+        (attr, syn::parse2::<Input>(attr.tokens.clone()).unwrap().0)
+    } else {
+        // This only fails if another macro removes `#[pin]`.
+        bail!(TokenStream::new(), "#[pin_project] attribute has been removed");
+    };
+
+    if let Some(attr) = attrs.next() {
+        let (prev_attr, prev_res) = &prev;
+        // As the `#[pin]` attribute generated by `#[pin_project]`
+        // has the same span as `#[pin_project]`, it is possible
+        // that a useless error message will be generated.
+        // So, use the span of `prev_attr` if it is not a valid attribute.
+        let res = syn::parse2::<Input>(attr.tokens.clone()).unwrap().0;
+        let span = match (prev_res, res) {
+            (Some(_), _) => attr,
+            (None, _) => prev_attr,
+        };
+        bail!(span, "duplicate #[pin] attribute");
+    }
+    // This `unwrap` only fails if another macro removes `#[pin]` and inserts own `#[pin]`.
+    syn::parse2(prev.1.unwrap())
+}
+
+pub(super) struct Args {
+    /// `PinnedDrop` argument.
+    pub(super) pinned_drop: Option<Span>,
+    /// `UnsafeUnpin` or `!Unpin` argument.
+    pub(super) unpin_impl: UnpinImpl,
+    /// `project = <ident>` argument.
+    pub(super) project: Option<Ident>,
+    /// `project_ref = <ident>` argument.
+    pub(super) project_ref: Option<Ident>,
+    /// `project_replace [= <ident>]` argument.
+    pub(super) project_replace: ProjReplace,
+}
+
+impl Parse for Args {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        mod kw {
+            syn::custom_keyword!(Unpin);
+        }
+
+        /// Parses `= <value>` in `<name> = <value>` and returns value and span of name-value pair.
+        fn parse_value(
+            input: ParseStream<'_>,
+            name: &Ident,
+            has_prev: bool,
+        ) -> Result<(Ident, TokenStream)> {
+            if input.is_empty() {
+                bail!(name, "expected `{0} = <identifier>`, found `{0}`", name);
+            }
+            let eq_token: Token![=] = input.parse()?;
+            if input.is_empty() {
+                let span = quote!(#name #eq_token);
+                bail!(span, "expected `{0} = <identifier>`, found `{0} =`", name);
+            }
+            let value: Ident = input.parse()?;
+            let span = quote!(#name #value);
+            if has_prev {
+                bail!(span, "duplicate `{}` argument", name);
+            }
+            Ok((value, span))
+        }
+
+        let mut pinned_drop = None;
+        let mut unsafe_unpin = None;
+        let mut not_unpin = None;
+        let mut project = None;
+        let mut project_ref = None;
+        let mut project_replace_value = None;
+        let mut project_replace_span = None;
+
+        while !input.is_empty() {
+            if input.peek(Token![!]) {
+                let bang: Token![!] = input.parse()?;
+                if input.is_empty() {
+                    bail!(bang, "expected `!Unpin`, found `!`");
+                }
+                let unpin: kw::Unpin = input.parse()?;
+                let span = quote!(#bang #unpin);
+                if not_unpin.replace(span.span()).is_some() {
+                    bail!(span, "duplicate `!Unpin` argument");
+                }
+            } else {
+                let token = input.parse::<Ident>()?;
+                match &*token.to_string() {
+                    "PinnedDrop" => {
+                        if pinned_drop.replace(token.span()).is_some() {
+                            bail!(token, "duplicate `PinnedDrop` argument");
+                        }
+                    }
+                    "UnsafeUnpin" => {
+                        if unsafe_unpin.replace(token.span()).is_some() {
+                            bail!(token, "duplicate `UnsafeUnpin` argument");
+                        }
+                    }
+                    "project" => {
+                        project = Some(parse_value(input, &token, project.is_some())?.0);
+                    }
+                    "project_ref" => {
+                        project_ref = Some(parse_value(input, &token, project_ref.is_some())?.0);
+                    }
+                    "project_replace" => {
+                        if input.peek(Token![=]) {
+                            let (value, span) =
+                                parse_value(input, &token, project_replace_span.is_some())?;
+                            project_replace_value = Some(value);
+                            project_replace_span = Some(span.span());
+                        } else if project_replace_span.is_some() {
+                            bail!(token, "duplicate `project_replace` argument");
+                        } else {
+                            project_replace_span = Some(token.span());
+                        }
+                    }
+                    "Replace" => {
+                        bail!(
+                            token,
+                            "`Replace` argument was removed, use `project_replace` argument instead"
+                        );
+                    }
+                    _ => bail!(token, "unexpected argument: {}", token),
+                }
+            }
+
+            if input.is_empty() {
+                break;
+            }
+            let _: Token![,] = input.parse()?;
+        }
+
+        if project.is_some() || project_ref.is_some() {
+            if project == project_ref {
+                bail!(
+                    project_ref,
+                    "name `{}` is already specified by `project` argument",
+                    project_ref.as_ref().unwrap()
+                );
+            }
+            if let Some(ident) = &project_replace_value {
+                if project == project_replace_value {
+                    bail!(ident, "name `{}` is already specified by `project` argument", ident);
+                } else if project_ref == project_replace_value {
+                    bail!(ident, "name `{}` is already specified by `project_ref` argument", ident);
+                }
+            }
+        }
+
+        if let Some(span) = pinned_drop {
+            if project_replace_span.is_some() {
+                return Err(Error::new(
+                    span,
+                    "arguments `PinnedDrop` and `project_replace` are mutually exclusive",
+                ));
+            }
+        }
+        let project_replace = match (project_replace_span, project_replace_value) {
+            (None, _) => ProjReplace::None,
+            (Some(span), Some(ident)) => ProjReplace::Named { ident, span },
+            (Some(span), None) => ProjReplace::Unnamed { span },
+        };
+        let unpin_impl = match (unsafe_unpin, not_unpin) {
+            (None, None) => UnpinImpl::Default,
+            (Some(span), None) => UnpinImpl::Unsafe(span),
+            (None, Some(span)) => UnpinImpl::Negative(span),
+            (Some(span), Some(_)) => {
+                return Err(Error::new(
+                    span,
+                    "arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive",
+                ));
+            }
+        };
+
+        Ok(Self { pinned_drop, unpin_impl, project, project_ref, project_replace })
+    }
+}
+
+/// `UnsafeUnpin` or `!Unpin` argument.
+#[derive(Clone, Copy)]
+pub(super) enum UnpinImpl {
+    Default,
+    /// `UnsafeUnpin`.
+    Unsafe(Span),
+    /// `!Unpin`.
+    Negative(Span),
+}
+
+/// `project_replace [= <ident>]` argument.
+pub(super) enum ProjReplace {
+    None,
+    /// `project_replace`.
+    Unnamed {
+        span: Span,
+    },
+    /// `project_replace = <ident>`.
+    #[allow(dead_code)] // false positive that fixed in Rust 1.38
+    Named {
+        span: Span,
+        ident: Ident,
+    },
+}
+
+impl ProjReplace {
+    /// Return the span of this argument.
+    pub(super) fn span(&self) -> Option<Span> {
+        match self {
+            Self::None => None,
+            Self::Named { span, .. } | Self::Unnamed { span, .. } => Some(*span),
+        }
+    }
+
+    pub(super) fn ident(&self) -> Option<&Ident> {
+        if let Self::Named { ident, .. } = self {
+            Some(ident)
+        } else {
+            None
+        }
+    }
+}
diff --git a/third_party/rust/pin-project-internal/src/pin_project/attribute.rs b/third_party/rust/pin-project-internal/src/pin_project/attribute.rs
new file mode 100644
index 0000000000..7adfc07d59
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/pin_project/attribute.rs
@@ -0,0 +1,65 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::{
+    parse::{Parse, ParseStream},
+    Attribute, Result, Token, Visibility,
+};
+
+use super::PIN;
+use crate::utils::SliceExt;
+
+// To generate the correct `Unpin` implementation and the projection methods,
+// we need to collect the types of the pinned fields.
+// However, since proc-macro-attribute is applied before `cfg` and `cfg_attr`
+// on fields, we cannot be collecting field types properly at this timing.
+// So instead of generating the `Unpin` implementation and the projection
+// methods here, delegate their processing to proc-macro-derive.
+//
+// At this stage, only attributes are parsed and the following attributes are
+// added to the attributes of the item.
+// - `#[derive(InternalDerive)]` - An internal helper macro that does the above
+//   processing.
+// - `#[pin(__private(#args))]` - Pass the argument of `#[pin_project]` to
+//   proc-macro-derive (`InternalDerive`).
+
+pub(super) fn parse_attribute(args: &TokenStream, input: TokenStream) -> Result<TokenStream> {
+    let Input { attrs, body } = syn::parse2(input)?;
+
+    Ok(quote! {
+        #(#attrs)*
+        #[derive(::pin_project::__private::__PinProjectInternalDerive)]
+        // Use `__private` to prevent users from trying to control `InternalDerive`
+        // manually. `__private` does not guarantee compatibility between patch
+        // versions, so it should be sufficient for this purpose in most cases.
+        #[pin(__private(#args))]
+        #body
+    })
+}
+
+#[allow(dead_code)] // false positive that fixed in Rust 1.39
+struct Input {
+    attrs: Vec<Attribute>,
+    body: TokenStream,
+}
+
+impl Parse for Input {
+    fn parse(input: ParseStream<'_>) -> Result<Self> {
+        let attrs = input.call(Attribute::parse_outer)?;
+
+        let ahead = input.fork();
+        let _vis: Visibility = ahead.parse()?;
+        if !ahead.peek(Token![struct]) && !ahead.peek(Token![enum]) {
+            // If we check this only on proc-macro-derive, it may generate unhelpful error
+            // messages. So it is preferable to be able to detect it here.
+            bail!(
+                input.parse::<TokenStream>()?,
+                "#[pin_project] attribute may only be used on structs or enums"
+            );
+        } else if let Some(attr) = attrs.find(PIN) {
+            bail!(attr, "#[pin] attribute may only be used on fields of structs or variants");
+        } else if let Some(attr) = attrs.find("pin_project") {
+            bail!(attr, "duplicate #[pin_project] attribute");
+        }
+        Ok(Self { attrs, body: input.parse()? })
+    }
+}
diff --git a/third_party/rust/pin-project-internal/src/pin_project/derive.rs b/third_party/rust/pin-project-internal/src/pin_project/derive.rs
new file mode 100644
index 0000000000..fd2375dc3b
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/pin_project/derive.rs
@@ -0,0 +1,1127 @@
+use proc_macro2::{Delimiter, Group, Span, TokenStream};
+use quote::{format_ident, quote, quote_spanned, ToTokens};
+use syn::{
+    parse_quote, token, visit_mut::VisitMut, Attribute, Data, DataEnum, DeriveInput, Error, Field,
+    Fields, FieldsNamed, FieldsUnnamed, Generics, Ident, Index, Lifetime, LifetimeDef, Meta,
+    MetaList, MetaNameValue, NestedMeta, Result, Token, Type, Variant, Visibility, WhereClause,
+};
+
+use super::{
+    args::{parse_args, Args, ProjReplace, UnpinImpl},
+    PIN,
+};
+use crate::utils::{
+    determine_lifetime_name, determine_visibility, insert_lifetime_and_bound, ReplaceReceiver,
+    SliceExt, Variants,
+};
+
+pub(super) fn parse_derive(input: TokenStream) -> Result<TokenStream> {
+    let mut input: DeriveInput = syn::parse2(input)?;
+
+    let mut cx;
+    let mut generate = GenerateTokens::default();
+
+    let ident = &input.ident;
+    let ty_generics = input.generics.split_for_impl().1;
+    let self_ty = parse_quote!(#ident #ty_generics);
+    let mut visitor = ReplaceReceiver(&self_ty);
+    visitor.visit_generics_mut(&mut input.generics);
+    visitor.visit_data_mut(&mut input.data);
+
+    match &input.data {
+        Data::Struct(data) => {
+            cx = Context::new(&input.attrs, &input.vis, ident, &mut input.generics, Struct)?;
+            parse_struct(&mut cx, &data.fields, &mut generate)?;
+        }
+        Data::Enum(data) => {
+            cx = Context::new(&input.attrs, &input.vis, ident, &mut input.generics, Enum)?;
+            parse_enum(&mut cx, data, &mut generate)?;
+        }
+        Data::Union(_) => {
+            bail!(input, "#[pin_project] attribute may only be used on structs or enums");
+        }
+    }
+
+    Ok(generate.into_tokens(&cx))
+}
+
+#[derive(Default)]
+struct GenerateTokens {
+    exposed: TokenStream,
+    scoped: TokenStream,
+}
+
+impl GenerateTokens {
+    fn extend(&mut self, expose: bool, tokens: TokenStream) {
+        if expose {
+            self.exposed.extend(tokens);
+        } else {
+            self.scoped.extend(tokens);
+        }
+    }
+
+    fn into_tokens(self, cx: &Context<'_>) -> TokenStream {
+        let mut tokens = self.exposed;
+        let scoped = self.scoped;
+
+        let unpin_impl = make_unpin_impl(cx);
+        let drop_impl = make_drop_impl(cx);
+        let allowed_lints = global_allowed_lints();
+
+        tokens.extend(quote! {
+            // All items except projected types are generated inside a `const` scope.
+            // This makes it impossible for user code to refer to these types.
+            // However, this prevents Rustdoc from displaying docs for any
+            // of our types. In particular, users cannot see the
+            // automatically generated `Unpin` impl for the '__UnpinStruct' types
+            //
+            // Previously, we provided a flag to correctly document the
+            // automatically generated `Unpin` impl by using def-site hygiene,
+            // but it is now removed.
+            //
+            // Refs:
+            // - https://github.com/rust-lang/rust/issues/63281
+            // - https://github.com/taiki-e/pin-project/pull/53#issuecomment-525906867
+            // - https://github.com/taiki-e/pin-project/pull/70
+            #allowed_lints
+            #[allow(unused_qualifications)]
+            #[allow(clippy::semicolon_if_nothing_returned)]
+            #[allow(clippy::use_self)]
+            #[allow(clippy::used_underscore_binding)]
+            const _: () = {
+                #[allow(unused_extern_crates)]
+                extern crate pin_project as _pin_project;
+                #scoped
+                #unpin_impl
+                #drop_impl
+            };
+        });
+        tokens
+    }
+}
+
+/// Returns attributes that should be applied to all generated code.
+fn global_allowed_lints() -> TokenStream {
+    quote! {
+        #[allow(box_pointers)] // This lint warns use of the `Box` type.
+        #[allow(deprecated)]
+        #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+        #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+        #[allow(unreachable_pub)] // This lint warns `pub` field in private struct.
+        #[allow(unused_tuple_struct_fields)]
+        // This lint warns of `clippy::*` generated by external macros.
+        // We allow this lint for compatibility with older compilers.
+        #[allow(clippy::unknown_clippy_lints)]
+        #[allow(clippy::pattern_type_mismatch)]
+        #[allow(clippy::redundant_pub_crate)] // This lint warns `pub(crate)` field in private struct.
+        #[allow(clippy::type_repetition_in_bounds)] // https://github.com/rust-lang/rust-clippy/issues/4326
+    }
+}
+
+/// Returns attributes used on projected types.
+fn proj_allowed_lints(cx: &Context<'_>) -> (TokenStream, TokenStream, TokenStream) {
+    let large_enum_variant = if cx.kind == Enum {
+        Some(quote! {
+            #[allow(variant_size_differences)]
+            #[allow(clippy::large_enum_variant)]
+        })
+    } else {
+        None
+    };
+    let global_allowed_lints = global_allowed_lints();
+    let proj_mut_allowed_lints = if cx.project { Some(&global_allowed_lints) } else { None };
+    let proj_mut = quote! {
+        #proj_mut_allowed_lints
+        #[allow(dead_code)] // This lint warns unused fields/variants.
+        #[allow(clippy::mut_mut)] // This lint warns `&mut &mut <ty>`.
+    };
+    let proj_ref_allowed_lints = if cx.project_ref { Some(&global_allowed_lints) } else { None };
+    let proj_ref = quote! {
+        #proj_ref_allowed_lints
+        #[allow(dead_code)] // This lint warns unused fields/variants.
+        #[allow(clippy::ref_option_ref)] // This lint warns `&Option<&<ty>>`.
+    };
+    let proj_own_allowed_lints =
+        if cx.project_replace.ident().is_some() { Some(&global_allowed_lints) } else { None };
+    let proj_own = quote! {
+        #proj_own_allowed_lints
+        #[allow(dead_code)] // This lint warns unused fields/variants.
+        #large_enum_variant
+    };
+    (proj_mut, proj_ref, proj_own)
+}
+
+struct Context<'a> {
+    /// The original type.
+    orig: OriginalType<'a>,
+    /// The projected types.
+    proj: ProjectedType,
+    /// Types of the pinned fields.
+    pinned_fields: Vec<&'a Type>,
+    /// Kind of the original type: struct or enum
+    kind: TypeKind,
+
+    /// `PinnedDrop` argument.
+    pinned_drop: Option<Span>,
+    /// `UnsafeUnpin` or `!Unpin` argument.
+    unpin_impl: UnpinImpl,
+    /// `project` argument.
+    project: bool,
+    /// `project_ref` argument.
+    project_ref: bool,
+    /// `project_replace [= <ident>]` argument.
+    project_replace: ProjReplace,
+}
+
+impl<'a> Context<'a> {
+    fn new(
+        attrs: &'a [Attribute],
+        vis: &'a Visibility,
+        ident: &'a Ident,
+        generics: &'a mut Generics,
+        kind: TypeKind,
+    ) -> Result<Self> {
+        let Args { pinned_drop, unpin_impl, project, project_ref, project_replace } =
+            parse_args(attrs)?;
+
+        if let Some(name) = [project.as_ref(), project_ref.as_ref(), project_replace.ident()]
+            .iter()
+            .filter_map(Option::as_ref)
+            .find(|name| **name == ident)
+        {
+            bail!(name, "name `{}` is the same as the original type name", name);
+        }
+
+        let mut lifetime_name = String::from("'pin");
+        determine_lifetime_name(&mut lifetime_name, generics);
+        let lifetime = Lifetime::new(&lifetime_name, Span::call_site());
+
+        let ty_generics = generics.split_for_impl().1;
+        let ty_generics_as_generics = parse_quote!(#ty_generics);
+        let mut proj_generics = generics.clone();
+        let pred = insert_lifetime_and_bound(
+            &mut proj_generics,
+            lifetime.clone(),
+            &ty_generics_as_generics,
+            ident,
+        );
+        let mut where_clause = generics.make_where_clause().clone();
+        where_clause.predicates.push(pred);
+
+        let own_ident = project_replace
+            .ident()
+            .cloned()
+            .unwrap_or_else(|| format_ident!("__{}ProjectionOwned", ident));
+
+        Ok(Self {
+            kind,
+            pinned_drop,
+            unpin_impl,
+            project: project.is_some(),
+            project_ref: project_ref.is_some(),
+            project_replace,
+            proj: ProjectedType {
+                vis: determine_visibility(vis),
+                mut_ident: project.unwrap_or_else(|| format_ident!("__{}Projection", ident)),
+                ref_ident: project_ref.unwrap_or_else(|| format_ident!("__{}ProjectionRef", ident)),
+                own_ident,
+                lifetime,
+                generics: proj_generics,
+                where_clause,
+            },
+            orig: OriginalType { attrs, vis, ident, generics },
+            pinned_fields: Vec::new(),
+        })
+    }
+}
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+enum TypeKind {
+    Enum,
+    Struct,
+}
+
+use TypeKind::{Enum, Struct};
+
+struct OriginalType<'a> {
+    /// Attributes of the original type.
+    attrs: &'a [Attribute],
+    /// Visibility of the original type.
+    vis: &'a Visibility,
+    /// Name of the original type.
+    ident: &'a Ident,
+    /// Generics of the original type.
+    generics: &'a Generics,
+}
+
+struct ProjectedType {
+    /// Visibility of the projected types.
+    vis: Visibility,
+    /// Name of the projected type returned by `project` method.
+    mut_ident: Ident,
+    /// Name of the projected type returned by `project_ref` method.
+    ref_ident: Ident,
+    /// Name of the projected type returned by `project_replace` method.
+    own_ident: Ident,
+    /// Lifetime on the generated projected types.
+    lifetime: Lifetime,
+    /// Generics of the projected types.
+    generics: Generics,
+    /// `where` clause of the projected types. This has an additional
+    /// bound generated by `insert_lifetime_and_bound`
+    where_clause: WhereClause,
+}
+
+struct ProjectedVariants {
+    proj_variants: TokenStream,
+    proj_ref_variants: TokenStream,
+    proj_own_variants: TokenStream,
+    proj_arms: TokenStream,
+    proj_ref_arms: TokenStream,
+    proj_own_arms: TokenStream,
+}
+
+#[derive(Default)]
+struct ProjectedFields {
+    proj_pat: TokenStream,
+    proj_body: TokenStream,
+    proj_own_body: TokenStream,
+    proj_fields: TokenStream,
+    proj_ref_fields: TokenStream,
+    proj_own_fields: TokenStream,
+}
+
+fn validate_struct(ident: &Ident, fields: &Fields) -> Result<()> {
+    if fields.is_empty() {
+        let msg = "#[pin_project] attribute may not be used on structs with zero fields";
+        if let Fields::Unit = fields {
+            bail!(ident, msg)
+        }
+        bail!(fields, msg)
+    }
+    Ok(())
+}
+
+fn validate_enum(brace_token: token::Brace, variants: &Variants) -> Result<()> {
+    if variants.is_empty() {
+        return Err(Error::new(
+            brace_token.span,
+            "#[pin_project] attribute may not be used on enums without variants",
+        ));
+    }
+    let has_field = variants.iter().try_fold(false, |has_field, v| {
+        if let Some((_, e)) = &v.discriminant {
+            bail!(e, "#[pin_project] attribute may not be used on enums with discriminants");
+        } else if let Some(attr) = v.attrs.find(PIN) {
+            bail!(attr, "#[pin] attribute may only be used on fields of structs or variants");
+        } else if v.fields.is_empty() {
+            Ok(has_field)
+        } else {
+            Ok(true)
+        }
+    })?;
+    if has_field {
+        Ok(())
+    } else {
+        bail!(variants, "#[pin_project] attribute may not be used on enums with zero fields");
+    }
+}
+
+fn parse_struct<'a>(
+    cx: &mut Context<'a>,
+    fields: &'a Fields,
+    generate: &mut GenerateTokens,
+) -> Result<()> {
+    // Do this first for a better error message.
+    let packed_check = ensure_not_packed(&cx.orig, Some(fields))?;
+
+    validate_struct(cx.orig.ident, fields)?;
+
+    let ProjectedFields {
+        proj_pat,
+        proj_body,
+        proj_fields,
+        proj_ref_fields,
+        proj_own_fields,
+        proj_own_body,
+    } = match fields {
+        Fields::Named(_) => visit_fields(cx, None, fields, Delimiter::Brace)?,
+        Fields::Unnamed(_) => visit_fields(cx, None, fields, Delimiter::Parenthesis)?,
+        Fields::Unit => unreachable!(),
+    };
+
+    let proj_ident = &cx.proj.mut_ident;
+    let proj_ref_ident = &cx.proj.ref_ident;
+    let proj_own_ident = &cx.proj.own_ident;
+    let vis = &cx.proj.vis;
+    let mut orig_generics = cx.orig.generics.clone();
+    let orig_where_clause = orig_generics.where_clause.take();
+    let proj_generics = &cx.proj.generics;
+    let proj_where_clause = &cx.proj.where_clause;
+
+    // For tuple structs, we need to generate `(T1, T2) where Foo: Bar`
+    // For non-tuple structs, we need to generate `where Foo: Bar { field1: T }`
+    let (where_clause_fields, where_clause_ref_fields, where_clause_own_fields) = match fields {
+        Fields::Named(_) => (
+            quote!(#proj_where_clause #proj_fields),
+            quote!(#proj_where_clause #proj_ref_fields),
+            quote!(#orig_where_clause #proj_own_fields),
+        ),
+        Fields::Unnamed(_) => (
+            quote!(#proj_fields #proj_where_clause;),
+            quote!(#proj_ref_fields #proj_where_clause;),
+            quote!(#proj_own_fields #orig_where_clause;),
+        ),
+        Fields::Unit => unreachable!(),
+    };
+
+    let (proj_attrs, proj_ref_attrs, proj_own_attrs) = proj_allowed_lints(cx);
+    generate.extend(cx.project, quote! {
+        #proj_attrs
+        #vis struct #proj_ident #proj_generics #where_clause_fields
+    });
+    generate.extend(cx.project_ref, quote! {
+        #proj_ref_attrs
+        #vis struct #proj_ref_ident #proj_generics #where_clause_ref_fields
+    });
+    if cx.project_replace.span().is_some() {
+        generate.extend(cx.project_replace.ident().is_some(), quote! {
+            #proj_own_attrs
+            #vis struct #proj_own_ident #orig_generics #where_clause_own_fields
+        });
+    }
+
+    let proj_mut_body = quote! {
+        let Self #proj_pat = self.get_unchecked_mut();
+        #proj_ident #proj_body
+    };
+    let proj_ref_body = quote! {
+        let Self #proj_pat = self.get_ref();
+        #proj_ref_ident #proj_body
+    };
+    let proj_own_body = quote! {
+        let Self #proj_pat = &mut *__self_ptr;
+        #proj_own_body
+    };
+    generate.extend(false, make_proj_impl(cx, &proj_mut_body, &proj_ref_body, &proj_own_body));
+
+    generate.extend(false, packed_check);
+    Ok(())
+}
+
+fn parse_enum<'a>(
+    cx: &mut Context<'a>,
+    DataEnum { brace_token, variants, .. }: &'a DataEnum,
+    generate: &mut GenerateTokens,
+) -> Result<()> {
+    if let ProjReplace::Unnamed { span } = &cx.project_replace {
+        return Err(Error::new(
+            *span,
+            "`project_replace` argument requires a value when used on enums",
+        ));
+    }
+
+    // #[repr(packed)] cannot be apply on enums and will be rejected by rustc.
+    // However, we should not rely on the behavior of rustc that rejects this.
+    // https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+    //
+    // Do this first for a better error message.
+    ensure_not_packed(&cx.orig, None)?;
+
+    validate_enum(*brace_token, variants)?;
+
+    let ProjectedVariants {
+        proj_variants,
+        proj_ref_variants,
+        proj_own_variants,
+        proj_arms,
+        proj_ref_arms,
+        proj_own_arms,
+    } = visit_variants(cx, variants)?;
+
+    let proj_ident = &cx.proj.mut_ident;
+    let proj_ref_ident = &cx.proj.ref_ident;
+    let proj_own_ident = &cx.proj.own_ident;
+    let vis = &cx.proj.vis;
+    let mut orig_generics = cx.orig.generics.clone();
+    let orig_where_clause = orig_generics.where_clause.take();
+    let proj_generics = &cx.proj.generics;
+    let proj_where_clause = &cx.proj.where_clause;
+
+    let (proj_attrs, proj_ref_attrs, proj_own_attrs) = proj_allowed_lints(cx);
+    if cx.project {
+        generate.extend(true, quote! {
+            #proj_attrs
+            #vis enum #proj_ident #proj_generics #proj_where_clause {
+                #proj_variants
+            }
+        });
+    }
+    if cx.project_ref {
+        generate.extend(true, quote! {
+            #proj_ref_attrs
+            #vis enum #proj_ref_ident #proj_generics #proj_where_clause {
+                #proj_ref_variants
+            }
+        });
+    }
+    if cx.project_replace.ident().is_some() {
+        generate.extend(true, quote! {
+            #proj_own_attrs
+            #vis enum #proj_own_ident #orig_generics #orig_where_clause {
+                #proj_own_variants
+            }
+        });
+    }
+
+    let proj_mut_body = quote! {
+        match self.get_unchecked_mut() {
+            #proj_arms
+        }
+    };
+    let proj_ref_body = quote! {
+        match self.get_ref() {
+            #proj_ref_arms
+        }
+    };
+    let proj_own_body = quote! {
+        match &mut *__self_ptr {
+            #proj_own_arms
+        }
+    };
+    generate.extend(false, make_proj_impl(cx, &proj_mut_body, &proj_ref_body, &proj_own_body));
+
+    Ok(())
+}
+
+fn visit_variants<'a>(cx: &mut Context<'a>, variants: &'a Variants) -> Result<ProjectedVariants> {
+    let mut proj_variants = TokenStream::new();
+    let mut proj_ref_variants = TokenStream::new();
+    let mut proj_own_variants = TokenStream::new();
+    let mut proj_arms = TokenStream::new();
+    let mut proj_ref_arms = TokenStream::new();
+    let mut proj_own_arms = TokenStream::new();
+
+    for Variant { ident, fields, .. } in variants {
+        let ProjectedFields {
+            proj_pat,
+            proj_body,
+            proj_fields,
+            proj_ref_fields,
+            proj_own_fields,
+            proj_own_body,
+        } = match fields {
+            Fields::Named(_) => visit_fields(cx, Some(ident), fields, Delimiter::Brace)?,
+            Fields::Unnamed(_) => visit_fields(cx, Some(ident), fields, Delimiter::Parenthesis)?,
+            Fields::Unit => ProjectedFields {
+                proj_own_body: proj_own_body(cx, Some(ident), None, &[]),
+                ..Default::default()
+            },
+        };
+
+        let proj_ident = &cx.proj.mut_ident;
+        let proj_ref_ident = &cx.proj.ref_ident;
+        proj_variants.extend(quote! {
+            #ident #proj_fields,
+        });
+        proj_ref_variants.extend(quote! {
+            #ident #proj_ref_fields,
+        });
+        proj_own_variants.extend(quote! {
+            #ident #proj_own_fields,
+        });
+        proj_arms.extend(quote! {
+            Self::#ident #proj_pat => #proj_ident::#ident #proj_body,
+        });
+        proj_ref_arms.extend(quote! {
+            Self::#ident #proj_pat => #proj_ref_ident::#ident #proj_body,
+        });
+        proj_own_arms.extend(quote! {
+            Self::#ident #proj_pat => { #proj_own_body }
+        });
+    }
+
+    Ok(ProjectedVariants {
+        proj_variants,
+        proj_ref_variants,
+        proj_own_variants,
+        proj_arms,
+        proj_ref_arms,
+        proj_own_arms,
+    })
+}
+
+fn visit_fields<'a>(
+    cx: &mut Context<'a>,
+    variant_ident: Option<&Ident>,
+    fields: &'a Fields,
+    delim: Delimiter,
+) -> Result<ProjectedFields> {
+    fn surround(delim: Delimiter, tokens: TokenStream) -> TokenStream {
+        Group::new(delim, tokens).into_token_stream()
+    }
+
+    let mut proj_pat = TokenStream::new();
+    let mut proj_body = TokenStream::new();
+    let mut proj_fields = TokenStream::new();
+    let mut proj_ref_fields = TokenStream::new();
+    let mut proj_own_fields = TokenStream::new();
+    let mut proj_move = TokenStream::new();
+    let mut pinned_bindings = Vec::with_capacity(fields.len());
+
+    for (i, Field { attrs, vis, ident, colon_token, ty }) in fields.iter().enumerate() {
+        let binding = ident.clone().unwrap_or_else(|| format_ident!("_{}", i));
+        proj_pat.extend(quote!(#binding,));
+        let lifetime = &cx.proj.lifetime;
+        if attrs.position_exact(PIN)?.is_some() {
+            proj_fields.extend(quote! {
+                #vis #ident #colon_token ::pin_project::__private::Pin<&#lifetime mut (#ty)>,
+            });
+            proj_ref_fields.extend(quote! {
+                #vis #ident #colon_token ::pin_project::__private::Pin<&#lifetime (#ty)>,
+            });
+            proj_own_fields.extend(quote! {
+                #vis #ident #colon_token ::pin_project::__private::PhantomData<#ty>,
+            });
+            proj_body.extend(quote! {
+                #ident #colon_token _pin_project::__private::Pin::new_unchecked(#binding),
+            });
+            proj_move.extend(quote! {
+                #ident #colon_token _pin_project::__private::PhantomData,
+            });
+
+            cx.pinned_fields.push(ty);
+            pinned_bindings.push(binding);
+        } else {
+            proj_fields.extend(quote! {
+                #vis #ident #colon_token &#lifetime mut (#ty),
+            });
+            proj_ref_fields.extend(quote! {
+                #vis #ident #colon_token &#lifetime (#ty),
+            });
+            proj_own_fields.extend(quote! {
+                #vis #ident #colon_token #ty,
+            });
+            proj_body.extend(quote! {
+                #binding,
+            });
+            proj_move.extend(quote! {
+                #ident #colon_token _pin_project::__private::ptr::read(#binding),
+            });
+        }
+    }
+
+    let proj_pat = surround(delim, proj_pat);
+    let proj_body = surround(delim, proj_body);
+    let proj_fields = surround(delim, proj_fields);
+    let proj_ref_fields = surround(delim, proj_ref_fields);
+    let proj_own_fields = surround(delim, proj_own_fields);
+
+    let proj_move = Group::new(delim, proj_move);
+    let proj_own_body = proj_own_body(cx, variant_ident, Some(&proj_move), &pinned_bindings);
+
+    Ok(ProjectedFields {
+        proj_pat,
+        proj_body,
+        proj_own_body,
+        proj_fields,
+        proj_ref_fields,
+        proj_own_fields,
+    })
+}
+
+/// Generates the processing that `project_replace` does for the struct or each variant.
+///
+/// Note: `pinned_fields` must be in declaration order.
+fn proj_own_body(
+    cx: &Context<'_>,
+    variant_ident: Option<&Ident>,
+    proj_move: Option<&Group>,
+    pinned_fields: &[Ident],
+) -> TokenStream {
+    let ident = &cx.proj.own_ident;
+    let proj_own = match variant_ident {
+        Some(variant_ident) => quote!(#ident::#variant_ident),
+        None => quote!(#ident),
+    };
+
+    // The fields of the struct and the active enum variant are dropped
+    // in declaration order.
+    // Refs: https://doc.rust-lang.org/reference/destructors.html
+    let pinned_fields = pinned_fields.iter().rev();
+
+    quote! {
+        // First, extract all the unpinned fields.
+        let __result = #proj_own #proj_move;
+
+        // Now create guards to drop all the pinned fields.
+        //
+        // Due to a compiler bug (https://github.com/rust-lang/rust/issues/47949)
+        // this must be in its own scope, or else `__result` will not be dropped
+        // if any of the destructors panic.
+        {
+            #(
+                let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(#pinned_fields);
+            )*
+        }
+
+        // Finally, return the result.
+        __result
+    }
+}
+
+/// Creates `Unpin` implementation for the original type.
+///
+/// The kind of `Unpin` impl generated depends on `unpin_impl` field:
+/// - `UnpinImpl::Unsafe` - Implements `Unpin` via `UnsafeUnpin` impl.
+/// - `UnpinImpl::Negative` - Generates `Unpin` impl with bounds that will never be true.
+/// - `UnpinImpl::Default` - Generates `Unpin` impl that requires `Unpin` for all pinned fields.
+fn make_unpin_impl(cx: &Context<'_>) -> TokenStream {
+    match cx.unpin_impl {
+        UnpinImpl::Unsafe(span) => {
+            let mut proj_generics = cx.proj.generics.clone();
+            let orig_ident = cx.orig.ident;
+            let lifetime = &cx.proj.lifetime;
+
+            // Make the error message highlight `UnsafeUnpin` argument.
+            proj_generics.make_where_clause().predicates.push(parse_quote_spanned! { span =>
+                _pin_project::__private::Wrapper<#lifetime, Self>: _pin_project::UnsafeUnpin
+            });
+
+            let (impl_generics, _, where_clause) = proj_generics.split_for_impl();
+            let ty_generics = cx.orig.generics.split_for_impl().1;
+
+            quote_spanned! { span =>
+                impl #impl_generics _pin_project::__private::Unpin for #orig_ident #ty_generics
+                #where_clause
+                {
+                }
+            }
+        }
+        UnpinImpl::Negative(span) => {
+            let mut proj_generics = cx.proj.generics.clone();
+            let orig_ident = cx.orig.ident;
+            let lifetime = &cx.proj.lifetime;
+
+            proj_generics.make_where_clause().predicates.push(parse_quote! {
+                _pin_project::__private::Wrapper<
+                    #lifetime, _pin_project::__private::PhantomPinned
+                >: _pin_project::__private::Unpin
+            });
+
+            let (proj_impl_generics, _, proj_where_clause) = proj_generics.split_for_impl();
+            let ty_generics = cx.orig.generics.split_for_impl().1;
+
+            // For interoperability with `forbid(unsafe_code)`, `unsafe` token should be
+            // call-site span.
+            let unsafety = <Token![unsafe]>::default();
+            quote_spanned! { span =>
+                impl #proj_impl_generics _pin_project::__private::Unpin
+                    for #orig_ident #ty_generics
+                #proj_where_clause
+                {
+                }
+
+                // Generate a dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+                //
+                // To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
+                // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
+                // impl, they'll get a "conflicting implementations of trait" error when
+                // coherence checks are run.
+                #[doc(hidden)]
+                #unsafety impl #proj_impl_generics _pin_project::UnsafeUnpin
+                    for #orig_ident #ty_generics
+                #proj_where_clause
+                {
+                }
+            }
+        }
+        UnpinImpl::Default => {
+            let mut full_where_clause = cx.orig.generics.where_clause.clone().unwrap();
+
+            // Generate a field in our new struct for every
+            // pinned field in the original type.
+            let fields = cx.pinned_fields.iter().enumerate().map(|(i, ty)| {
+                let field_ident = format_ident!("__field{}", i);
+                quote!(#field_ident: #ty)
+            });
+
+            // We could try to determine the subset of type parameters
+            // and lifetimes that are actually used by the pinned fields
+            // (as opposed to those only used by unpinned fields).
+            // However, this would be tricky and error-prone, since
+            // it's possible for users to create types that would alias
+            // with generic parameters (e.g. 'struct T').
+            //
+            // Instead, we generate a use of every single type parameter
+            // and lifetime used in the original struct. For type parameters,
+            // we generate code like this:
+            //
+            // ```rust
+            // struct AlwaysUnpin<T: ?Sized>(PhantomData<T>) {}
+            // impl<T: ?Sized> Unpin for AlwaysUnpin<T> {}
+            //
+            // ...
+            // _field: AlwaysUnpin<(A, B, C)>
+            // ```
+            //
+            // This ensures that any unused type parameters
+            // don't end up with `Unpin` bounds.
+            let lifetime_fields = cx.orig.generics.lifetimes().enumerate().map(
+                |(i, LifetimeDef { lifetime, .. })| {
+                    let field_ident = format_ident!("__lifetime{}", i);
+                    quote!(#field_ident: &#lifetime ())
+                },
+            );
+
+            let orig_ident = cx.orig.ident;
+            let struct_ident = format_ident!("__{}", orig_ident);
+            let vis = cx.orig.vis;
+            let lifetime = &cx.proj.lifetime;
+            let type_params = cx.orig.generics.type_params().map(|t| &t.ident);
+            let proj_generics = &cx.proj.generics;
+            let (proj_impl_generics, proj_ty_generics, _) = proj_generics.split_for_impl();
+            let (_, ty_generics, where_clause) = cx.orig.generics.split_for_impl();
+
+            full_where_clause.predicates.push(parse_quote! {
+                #struct_ident #proj_ty_generics: _pin_project::__private::Unpin
+            });
+
+            quote! {
+                // This needs to have the same visibility as the original type,
+                // due to the limitations of the 'public in private' error.
+                //
+                // Our goal is to implement the public trait `Unpin` for
+                // a potentially public user type. Because of this, rust
+                // requires that any types mentioned in the where clause of
+                // our `Unpin` impl also be public. This means that our generated
+                // `__UnpinStruct` type must also be public.
+                // However, we ensure that the user can never actually reference
+                // this 'public' type by creating this type in the inside of `const`.
+                #[allow(missing_debug_implementations)]
+                #vis struct #struct_ident #proj_generics #where_clause {
+                    __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+                        #lifetime, (#(_pin_project::__private::PhantomData<#type_params>),*)
+                    >,
+
+                    #(#fields,)*
+                    #(#lifetime_fields,)*
+                }
+
+                impl #proj_impl_generics _pin_project::__private::Unpin
+                    for #orig_ident #ty_generics
+                #full_where_clause
+                {
+                }
+
+                // Generate a dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+                //
+                // To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
+                // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
+                // impl, they'll get a "conflicting implementations of trait" error when
+                // coherence checks are run.
+                #[doc(hidden)]
+                unsafe impl #proj_impl_generics _pin_project::UnsafeUnpin
+                    for #orig_ident #ty_generics
+                #full_where_clause
+                {
+                }
+            }
+        }
+    }
+}
+
+/// Creates `Drop` implementation for the original type.
+///
+/// The kind of `Drop` impl generated depends on `pinned_drop` field:
+/// - `Some` - implements `Drop` via `PinnedDrop` impl.
+/// - `None` - generates code that ensures that `Drop` trait is not implemented,
+///            instead of generating `Drop` impl.
+fn make_drop_impl(cx: &Context<'_>) -> TokenStream {
+    let ident = cx.orig.ident;
+    let (impl_generics, ty_generics, where_clause) = cx.orig.generics.split_for_impl();
+
+    if let Some(span) = cx.pinned_drop {
+        // For interoperability with `forbid(unsafe_code)`, `unsafe` token should be
+        // call-site span.
+        let unsafety = <Token![unsafe]>::default();
+        quote_spanned! { span =>
+            impl #impl_generics _pin_project::__private::Drop for #ident #ty_generics
+            #where_clause
+            {
+                fn drop(&mut self) {
+                    #unsafety {
+                        // Safety - we're in 'drop', so we know that 'self' will
+                        // never move again.
+                        let __pinned_self = _pin_project::__private::Pin::new_unchecked(self);
+                        // We call `pinned_drop` only once. Since `PinnedDrop::drop`
+                        // is an unsafe method and a private API, it is never called again in safe
+                        // code *unless the user uses a maliciously crafted macro*.
+                        _pin_project::__private::PinnedDrop::drop(__pinned_self);
+                    }
+                }
+            }
+        }
+    } else {
+        // If the user does not provide a `PinnedDrop` impl,
+        // we need to ensure that they don't provide a `Drop` impl of their
+        // own.
+        // Based on https://github.com/upsuper/assert-impl/blob/f503255b292ab0ba8d085b657f4065403cfa46eb/src/lib.rs#L80-L87
+        //
+        // We create a new identifier for each struct, so that the traits
+        // for different types do not conflict with each other.
+        //
+        // Another approach would be to provide an empty Drop impl,
+        // which would conflict with a user-provided Drop impl.
+        // However, this would trigger the compiler's special handling
+        // of Drop types (e.g. fields cannot be moved out of a Drop type).
+        // This approach prevents the creation of needless Drop impls,
+        // giving users more flexibility.
+        let trait_ident = format_ident!("{}MustNotImplDrop", ident);
+
+        quote! {
+            // There are two possible cases:
+            // 1. The user type does not implement Drop. In this case,
+            // the first blanked impl will not apply to it. This code
+            // will compile, as there is only one impl of MustNotImplDrop for the user type
+            // 2. The user type does impl Drop. This will make the blanket impl applicable,
+            // which will then conflict with the explicit MustNotImplDrop impl below.
+            // This will result in a compilation error, which is exactly what we want.
+            trait #trait_ident {}
+            #[allow(clippy::drop_bounds, drop_bounds)]
+            impl<T: _pin_project::__private::Drop> #trait_ident for T {}
+            impl #impl_generics #trait_ident for #ident #ty_generics #where_clause {}
+
+            // Generate a dummy impl of `PinnedDrop`, to ensure that the user cannot implement it.
+            // Since the user did not pass `PinnedDrop` to `#[pin_project]`, any `PinnedDrop`
+            // impl will not actually be called. Unfortunately, we can't detect this situation
+            // directly from either the `#[pin_project]` or `#[pinned_drop]` attributes, since
+            // we don't know what other attributes/impl may exist.
+            //
+            // To ensure that users don't accidentally write a non-functional `PinnedDrop`
+            // impls, we emit one ourselves. If the user ends up writing a `PinnedDrop` impl,
+            // they'll get a "conflicting implementations of trait" error when coherence
+            // checks are run.
+            #[doc(hidden)]
+            impl #impl_generics _pin_project::__private::PinnedDrop for #ident #ty_generics
+            #where_clause
+            {
+                unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+            }
+        }
+    }
+}
+
+/// Creates an implementation of the projection methods.
+///
+/// On structs, both the `project` and `project_ref` methods are always generated,
+/// and the `project_replace` method is only generated if `ProjReplace::span` is `Some`.
+///
+/// On enums, only methods that the returned projected type is named will be generated.
+fn make_proj_impl(
+    cx: &Context<'_>,
+    proj_body: &TokenStream,
+    proj_ref_body: &TokenStream,
+    proj_own_body: &TokenStream,
+) -> TokenStream {
+    let vis = &cx.proj.vis;
+    let lifetime = &cx.proj.lifetime;
+    let orig_ident = cx.orig.ident;
+    let proj_ident = &cx.proj.mut_ident;
+    let proj_ref_ident = &cx.proj.ref_ident;
+    let proj_own_ident = &cx.proj.own_ident;
+
+    let orig_ty_generics = cx.orig.generics.split_for_impl().1;
+    let proj_ty_generics = cx.proj.generics.split_for_impl().1;
+    let (impl_generics, ty_generics, where_clause) = cx.orig.generics.split_for_impl();
+    // TODO: For enums and project_replace, dead_code warnings should not be
+    // allowed because methods are not generated unless explicitly specified.
+    // However, there is currently no good way to allow warnings for generated
+    // code, so we allow warnings for all methods for now.
+    let allow_dead_code = quote! { #[allow(dead_code)] };
+
+    let mut project = Some(quote! {
+        #allow_dead_code
+        #vis fn project<#lifetime>(
+            self: _pin_project::__private::Pin<&#lifetime mut Self>,
+        ) -> #proj_ident #proj_ty_generics {
+            unsafe {
+                #proj_body
+            }
+        }
+    });
+    let mut project_ref = Some(quote! {
+        #allow_dead_code
+        #[allow(clippy::missing_const_for_fn)]
+        #vis fn project_ref<#lifetime>(
+            self: _pin_project::__private::Pin<&#lifetime Self>,
+        ) -> #proj_ref_ident #proj_ty_generics {
+            unsafe {
+                #proj_ref_body
+            }
+        }
+    });
+    let mut project_replace = cx.project_replace.span().map(|span| {
+        // It is enough to only set the span of the signature.
+        let sig = quote_spanned! { span =>
+            #allow_dead_code
+            #vis fn project_replace(
+                self: _pin_project::__private::Pin<&mut Self>,
+                __replacement: Self,
+            ) -> #proj_own_ident #orig_ty_generics
+        };
+        quote! {
+            #sig {
+                unsafe {
+                    let __self_ptr: *mut Self = self.get_unchecked_mut();
+
+                    // Destructors will run in reverse order, so next create a guard to overwrite
+                    // `self` with the replacement value without calling destructors.
+                    let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                        __self_ptr,
+                        __replacement,
+                    );
+
+                    #proj_own_body
+                }
+            }
+        }
+    });
+
+    if cx.kind == Enum {
+        if !cx.project {
+            project = None;
+        }
+        if !cx.project_ref {
+            project_ref = None;
+        }
+        if cx.project_replace.ident().is_none() {
+            project_replace = None;
+        }
+    }
+
+    quote! {
+        impl #impl_generics #orig_ident #ty_generics #where_clause {
+            #project
+            #project_ref
+            #project_replace
+        }
+    }
+}
+
+/// Checks that the `[repr(packed)]` attribute is not included.
+///
+/// This currently does two checks:
+/// - Checks the attributes of structs to ensure there is no `[repr(packed)]`.
+/// - Generates a function that borrows fields without an unsafe block and
+///   forbidding `unaligned_references` lint.
+fn ensure_not_packed(orig: &OriginalType<'_>, fields: Option<&Fields>) -> Result<TokenStream> {
+    for meta in orig.attrs.iter().filter_map(|attr| attr.parse_meta().ok()) {
+        if let Meta::List(list) = meta {
+            if list.path.is_ident("repr") {
+                for repr in list.nested.iter() {
+                    match repr {
+                        NestedMeta::Meta(Meta::Path(path))
+                        | NestedMeta::Meta(Meta::List(MetaList { path, .. }))
+                        | NestedMeta::Meta(Meta::NameValue(MetaNameValue { path, .. })) => {
+                            if path.is_ident("packed") {
+                                let msg = if fields.is_none() {
+                                    // #[repr(packed)] cannot be apply on enums and will be rejected by rustc.
+                                    // However, we should not rely on the behavior of rustc that rejects this.
+                                    // https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+                                    "#[repr(packed)] attribute should be applied to a struct or union"
+                                } else if let NestedMeta::Meta(Meta::NameValue(..)) = repr {
+                                    // #[repr(packed = "")] is not valid format of #[repr(packed)] and will be
+                                    // rejected by rustc.
+                                    // However, we should not rely on the behavior of rustc that rejects this.
+                                    // https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+                                    "#[repr(packed)] attribute should not be name-value pair"
+                                } else {
+                                    "#[pin_project] attribute may not be used on #[repr(packed)] types"
+                                };
+                                bail!(repr, msg);
+                            }
+                        }
+                        NestedMeta::Lit(..) => {}
+                    }
+                }
+            }
+        }
+    }
+
+    let fields = match fields {
+        Some(fields) => fields,
+        None => return Ok(TokenStream::new()),
+    };
+
+    // Workaround for https://github.com/taiki-e/pin-project/issues/32
+    // Through the tricky use of proc macros, it's possible to bypass
+    // the above check for the `repr` attribute.
+    // To ensure that it's impossible to use pin projections on a `#[repr(packed)]`
+    // struct, we generate code like this:
+    //
+    // ```rust
+    // #[forbid(unaligned_references)]
+    // fn assert_not_repr_packed(val: &MyStruct) {
+    //     let _field1 = &val.field1;
+    //     let _field2 = &val.field2;
+    //     ...
+    //     let _fieldn = &val.fieldn;
+    // }
+    // ```
+    //
+    // Taking a reference to a packed field is UB, and applying
+    // `#[forbid(unaligned_references)]` makes sure that doing this is a hard error.
+    //
+    // If the struct ends up having `#[repr(packed)]` applied somehow,
+    // this will generate an (unfriendly) error message. Under all reasonable
+    // circumstances, we'll detect the `#[repr(packed)]` attribute, and generate
+    // a much nicer error above.
+    //
+    // There is one exception: If the type of a struct field has an alignment of 1
+    // (e.g. u8), it is always safe to take a reference to it, even if the struct
+    // is `#[repr(packed)]`. If the struct is composed entirely of types of
+    // alignment 1, our generated method will not trigger an error if the
+    // struct is `#[repr(packed)]`.
+    //
+    // Fortunately, this should have no observable consequence - `#[repr(packed)]`
+    // is essentially a no-op on such a type. Nevertheless, we include a test
+    // to ensure that the compiler doesn't ever try to copy the fields on
+    // such a struct when trying to drop it - which is reason we prevent
+    // `#[repr(packed)]` in the first place.
+    //
+    // See also https://github.com/taiki-e/pin-project/pull/34.
+    //
+    // Note:
+    // - Lint-based tricks aren't perfect, but they're much better than nothing:
+    //   https://github.com/taiki-e/pin-project-lite/issues/26
+    //
+    // - Enable both unaligned_references and safe_packed_borrows lints
+    //   because unaligned_references lint does not exist in older compilers:
+    //   https://github.com/taiki-e/pin-project-lite/pull/55
+    //   https://github.com/rust-lang/rust/pull/82525
+    let mut field_refs = vec![];
+    match fields {
+        Fields::Named(FieldsNamed { named, .. }) => {
+            for Field { ident, .. } in named {
+                field_refs.push(quote!(&this.#ident));
+            }
+        }
+        Fields::Unnamed(FieldsUnnamed { unnamed, .. }) => {
+            for (index, _) in unnamed.iter().enumerate() {
+                let index = Index::from(index);
+                field_refs.push(quote!(&this.#index));
+            }
+        }
+        Fields::Unit => {}
+    }
+
+    let (impl_generics, ty_generics, where_clause) = orig.generics.split_for_impl();
+    let ident = orig.ident;
+    Ok(quote! {
+        #[forbid(unaligned_references, safe_packed_borrows)]
+        fn __assert_not_repr_packed #impl_generics (this: &#ident #ty_generics) #where_clause {
+            #(let _ = #field_refs;)*
+        }
+    })
+}
diff --git a/third_party/rust/pin-project-internal/src/pin_project/mod.rs b/third_party/rust/pin-project-internal/src/pin_project/mod.rs
new file mode 100644
index 0000000000..2dce78f37f
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/pin_project/mod.rs
@@ -0,0 +1,17 @@
+mod args;
+mod attribute;
+mod derive;
+
+use proc_macro2::TokenStream;
+use syn::Error;
+
+/// The annotation for pinned type.
+const PIN: &str = "pin";
+
+pub(crate) fn attribute(args: &TokenStream, input: TokenStream) -> TokenStream {
+    attribute::parse_attribute(args, input).unwrap_or_else(Error::into_compile_error)
+}
+
+pub(crate) fn derive(input: TokenStream) -> TokenStream {
+    derive::parse_derive(input).unwrap_or_else(Error::into_compile_error)
+}
diff --git a/third_party/rust/pin-project-internal/src/pinned_drop.rs b/third_party/rust/pin-project-internal/src/pinned_drop.rs
new file mode 100644
index 0000000000..912989dd41
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/pinned_drop.rs
@@ -0,0 +1,226 @@
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote, ToTokens};
+use syn::{
+    parse_quote, spanned::Spanned, visit_mut::VisitMut, Error, FnArg, GenericArgument, ImplItem,
+    ItemImpl, Pat, PatIdent, Path, PathArguments, Result, ReturnType, Signature, Token, Type,
+    TypePath, TypeReference,
+};
+
+use crate::utils::{parse_as_empty, prepend_underscore_to_self, ReplaceReceiver, SliceExt};
+
+pub(crate) fn attribute(args: &TokenStream, mut input: ItemImpl) -> TokenStream {
+    let res = (|| -> Result<()> {
+        parse_as_empty(args)?;
+        validate_impl(&input)?;
+        expand_impl(&mut input);
+        Ok(())
+    })();
+
+    if let Err(e) = res {
+        let mut tokens = e.to_compile_error();
+        if let Type::Path(self_ty) = &*input.self_ty {
+            let (impl_generics, _, where_clause) = input.generics.split_for_impl();
+
+            // Generate a dummy impl of `PinnedDrop`.
+            // In many cases, `#[pinned_drop] impl` is declared after `#[pin_project]`.
+            // Therefore, if `pinned_drop` compile fails, you will also get an error
+            // about `PinnedDrop` not being implemented.
+            // This can be prevented to some extent by generating a dummy
+            // `PinnedDrop` implementation.
+            // We already know that we will get a compile error, so this won't
+            // accidentally compile successfully.
+            //
+            // However, if `input.self_ty` is not Type::Path, there is a high possibility that
+            // the type does not exist (since #[pin_project] can only be used on struct/enum
+            // definitions), so do not generate a dummy impl.
+            tokens.extend(quote! {
+                impl #impl_generics ::pin_project::__private::PinnedDrop for #self_ty
+                #where_clause
+                {
+                    unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+            });
+        }
+        tokens
+    } else {
+        input.into_token_stream()
+    }
+}
+
+/// Validates the signature of given `PinnedDrop` impl.
+fn validate_impl(item: &ItemImpl) -> Result<()> {
+    const INVALID_ITEM: &str =
+        "#[pinned_drop] may only be used on implementation for the `PinnedDrop` trait";
+
+    if let Some(attr) = item.attrs.find("pinned_drop") {
+        bail!(attr, "duplicate #[pinned_drop] attribute");
+    }
+
+    if let Some((_, path, _)) = &item.trait_ {
+        if !path.is_ident("PinnedDrop") {
+            bail!(path, INVALID_ITEM);
+        }
+    } else {
+        bail!(item.self_ty, INVALID_ITEM);
+    }
+
+    if item.unsafety.is_some() {
+        bail!(item.unsafety, "implementing the trait `PinnedDrop` is not unsafe");
+    }
+    if item.items.is_empty() {
+        bail!(item, "not all trait items implemented, missing: `drop`");
+    }
+
+    match &*item.self_ty {
+        Type::Path(_) => {}
+        ty => {
+            bail!(ty, "implementing the trait `PinnedDrop` on this type is unsupported");
+        }
+    }
+
+    item.items.iter().enumerate().try_for_each(|(i, item)| match item {
+        ImplItem::Const(item) => {
+            bail!(item, "const `{}` is not a member of trait `PinnedDrop`", item.ident)
+        }
+        ImplItem::Type(item) => {
+            bail!(item, "type `{}` is not a member of trait `PinnedDrop`", item.ident)
+        }
+        ImplItem::Method(method) => {
+            validate_sig(&method.sig)?;
+            if i == 0 {
+                Ok(())
+            } else {
+                bail!(method, "duplicate definitions with name `drop`")
+            }
+        }
+        _ => unreachable!("unexpected ImplItem"),
+    })
+}
+
+/// Validates the signature of given `PinnedDrop::drop` method.
+///
+/// The correct signature is: `(mut) self: (<path>::)Pin<&mut Self>`
+fn validate_sig(sig: &Signature) -> Result<()> {
+    fn get_ty_path(ty: &Type) -> Option<&Path> {
+        if let Type::Path(TypePath { qself: None, path }) = ty {
+            Some(path)
+        } else {
+            None
+        }
+    }
+
+    const INVALID_ARGUMENT: &str = "method `drop` must take an argument `self: Pin<&mut Self>`";
+
+    if sig.ident != "drop" {
+        bail!(sig.ident, "method `{}` is not a member of trait `PinnedDrop", sig.ident,);
+    }
+
+    if let ReturnType::Type(_, ty) = &sig.output {
+        match &**ty {
+            Type::Tuple(ty) if ty.elems.is_empty() => {}
+            _ => bail!(ty, "method `drop` must return the unit type"),
+        }
+    }
+
+    match sig.inputs.len() {
+        1 => {}
+        0 => return Err(Error::new(sig.paren_token.span, INVALID_ARGUMENT)),
+        _ => bail!(sig.inputs, INVALID_ARGUMENT),
+    }
+
+    if let Some(FnArg::Typed(arg)) = sig.receiver() {
+        // (mut) self: <path>
+        if let Some(path) = get_ty_path(&arg.ty) {
+            let ty = path.segments.last().unwrap();
+            if let PathArguments::AngleBracketed(args) = &ty.arguments {
+                // (mut) self: (<path>::)<ty><&mut <elem>..>
+                if let Some(GenericArgument::Type(Type::Reference(TypeReference {
+                    mutability: Some(_),
+                    elem,
+                    ..
+                }))) = args.args.first()
+                {
+                    // (mut) self: (<path>::)Pin<&mut Self>
+                    if args.args.len() == 1
+                        && ty.ident == "Pin"
+                        && get_ty_path(elem).map_or(false, |path| path.is_ident("Self"))
+                    {
+                        if sig.unsafety.is_some() {
+                            bail!(sig.unsafety, "implementing the method `drop` is not unsafe");
+                        }
+                        return Ok(());
+                    }
+                }
+            }
+        }
+    }
+
+    bail!(sig.inputs[0], INVALID_ARGUMENT)
+}
+
+// from:
+//
+// fn drop(self: Pin<&mut Self>) {
+//     // ...
+// }
+//
+// into:
+//
+// unsafe fn drop(self: Pin<&mut Self>) {
+//     fn __drop_inner<T>(__self: Pin<&mut Foo<'_, T>>) {
+//         fn __drop_inner() {}
+//         // ...
+//     }
+//     __drop_inner(self);
+// }
+//
+fn expand_impl(item: &mut ItemImpl) {
+    fn get_arg_pat(arg: &mut FnArg) -> Option<&mut PatIdent> {
+        if let FnArg::Typed(arg) = arg {
+            if let Pat::Ident(ident) = &mut *arg.pat {
+                return Some(ident);
+            }
+        }
+        None
+    }
+
+    // `PinnedDrop` is a private trait and should not appear in docs.
+    item.attrs.push(parse_quote!(#[doc(hidden)]));
+
+    let path = &mut item.trait_.as_mut().unwrap().1;
+    *path = parse_quote_spanned! { path.span() =>
+        ::pin_project::__private::PinnedDrop
+    };
+
+    let method =
+        if let ImplItem::Method(method) = &mut item.items[0] { method } else { unreachable!() };
+
+    // `fn drop(mut self: Pin<&mut Self>)` -> `fn __drop_inner<T>(mut __self: Pin<&mut Receiver>)`
+    let drop_inner = {
+        let mut drop_inner = method.clone();
+        let ident = format_ident!("__drop_inner");
+        // Add a dummy `__drop_inner` function to prevent users call outer `__drop_inner`.
+        drop_inner.block.stmts.insert(0, parse_quote!(fn #ident() {}));
+        drop_inner.sig.ident = ident;
+        drop_inner.sig.generics = item.generics.clone();
+        let self_pat = get_arg_pat(&mut drop_inner.sig.inputs[0]).unwrap();
+        prepend_underscore_to_self(&mut self_pat.ident);
+        let self_ty = if let Type::Path(ty) = &*item.self_ty { ty } else { unreachable!() };
+        let mut visitor = ReplaceReceiver(self_ty);
+        visitor.visit_signature_mut(&mut drop_inner.sig);
+        visitor.visit_block_mut(&mut drop_inner.block);
+        drop_inner
+    };
+
+    // `fn drop(mut self: Pin<&mut Self>)` -> `unsafe fn drop(self: Pin<&mut Self>)`
+    method.sig.unsafety = Some(<Token![unsafe]>::default());
+    let self_pat = get_arg_pat(&mut method.sig.inputs[0]).unwrap();
+    self_pat.mutability = None;
+    let self_token = &self_pat.ident;
+
+    method.block.stmts = parse_quote! {
+        #[allow(clippy::needless_pass_by_value)] // This lint does not warn the receiver.
+        #drop_inner
+        __drop_inner(#self_token);
+    };
+}
diff --git a/third_party/rust/pin-project-internal/src/utils.rs b/third_party/rust/pin-project-internal/src/utils.rs
new file mode 100644
index 0000000000..27373efbae
--- /dev/null
+++ b/third_party/rust/pin-project-internal/src/utils.rs
@@ -0,0 +1,402 @@
+use std::{iter::FromIterator, mem};
+
+use proc_macro2::{Group, Spacing, Span, TokenStream, TokenTree};
+use quote::{quote, quote_spanned, ToTokens};
+use syn::{
+    parse::{Parse, ParseBuffer, ParseStream},
+    parse_quote,
+    punctuated::Punctuated,
+    token,
+    visit_mut::{self, VisitMut},
+    Attribute, ExprPath, ExprStruct, Generics, Ident, Item, Lifetime, LifetimeDef, Macro, PatPath,
+    PatStruct, PatTupleStruct, Path, PathArguments, PredicateType, QSelf, Result, Token, Type,
+    TypeParamBound, TypePath, Variant, Visibility, WherePredicate,
+};
+
+pub(crate) type Variants = Punctuated<Variant, Token![,]>;
+
+macro_rules! format_err {
+    ($span:expr, $msg:expr $(,)?) => {
+        syn::Error::new_spanned(&$span as &dyn quote::ToTokens, &$msg as &dyn std::fmt::Display)
+    };
+    ($span:expr, $($tt:tt)*) => {
+        format_err!($span, format!($($tt)*))
+    };
+}
+
+macro_rules! bail {
+    ($($tt:tt)*) => {
+        return Err(format_err!($($tt)*))
+    };
+}
+
+macro_rules! parse_quote_spanned {
+    ($span:expr => $($tt:tt)*) => {
+        syn::parse2(quote::quote_spanned!($span => $($tt)*)).unwrap_or_else(|e| panic!("{}", e))
+    };
+}
+
+/// Determines the lifetime names. Ensure it doesn't overlap with any existing
+/// lifetime names.
+pub(crate) fn determine_lifetime_name(lifetime_name: &mut String, generics: &mut Generics) {
+    struct CollectLifetimes(Vec<String>);
+
+    impl VisitMut for CollectLifetimes {
+        fn visit_lifetime_def_mut(&mut self, def: &mut LifetimeDef) {
+            self.0.push(def.lifetime.to_string());
+        }
+    }
+
+    debug_assert!(lifetime_name.starts_with('\''));
+
+    let mut lifetimes = CollectLifetimes(Vec::new());
+    lifetimes.visit_generics_mut(generics);
+
+    while lifetimes.0.iter().any(|name| name.starts_with(&**lifetime_name)) {
+        lifetime_name.push('_');
+    }
+}
+
+/// Like `insert_lifetime`, but also generates a bound of the form
+/// `OriginalType<A, B>: 'lifetime`. Used when generating the definition
+/// of a projection type
+pub(crate) fn insert_lifetime_and_bound(
+    generics: &mut Generics,
+    lifetime: Lifetime,
+    orig_generics: &Generics,
+    orig_ident: &Ident,
+) -> WherePredicate {
+    insert_lifetime(generics, lifetime.clone());
+
+    let orig_type: Type = parse_quote!(#orig_ident #orig_generics);
+    let mut punct = Punctuated::new();
+    punct.push(TypeParamBound::Lifetime(lifetime));
+
+    WherePredicate::Type(PredicateType {
+        lifetimes: None,
+        bounded_ty: orig_type,
+        colon_token: <Token![:]>::default(),
+        bounds: punct,
+    })
+}
+
+/// Inserts a `lifetime` at position `0` of `generics.params`.
+pub(crate) fn insert_lifetime(generics: &mut Generics, lifetime: Lifetime) {
+    generics.lt_token.get_or_insert_with(<Token![<]>::default);
+    generics.gt_token.get_or_insert_with(<Token![>]>::default);
+    generics.params.insert(0, LifetimeDef::new(lifetime).into());
+}
+
+/// Determines the visibility of the projected types and projection methods.
+///
+/// If given visibility is `pub`, returned visibility is `pub(crate)`.
+/// Otherwise, returned visibility is the same as given visibility.
+pub(crate) fn determine_visibility(vis: &Visibility) -> Visibility {
+    if let Visibility::Public(token) = vis {
+        parse_quote_spanned!(token.pub_token.span => pub(crate))
+    } else {
+        vis.clone()
+    }
+}
+
+/// Checks if `tokens` is an empty `TokenStream`.
+///
+/// This is almost equivalent to `syn::parse2::<Nothing>()`, but produces
+/// a better error message and does not require ownership of `tokens`.
+pub(crate) fn parse_as_empty(tokens: &TokenStream) -> Result<()> {
+    if tokens.is_empty() {
+        Ok(())
+    } else {
+        bail!(tokens, "unexpected token: `{}`", tokens)
+    }
+}
+
+pub(crate) fn respan<T>(node: &T, span: Span) -> T
+where
+    T: ToTokens + Parse,
+{
+    let tokens = node.to_token_stream();
+    let respanned = respan_tokens(tokens, span);
+    syn::parse2(respanned).unwrap()
+}
+
+fn respan_tokens(tokens: TokenStream, span: Span) -> TokenStream {
+    tokens
+        .into_iter()
+        .map(|mut token| {
+            token.set_span(span);
+            token
+        })
+        .collect()
+}
+
+// =================================================================================================
+// extension traits
+
+pub(crate) trait SliceExt {
+    fn position_exact(&self, ident: &str) -> Result<Option<usize>>;
+    fn find(&self, ident: &str) -> Option<&Attribute>;
+}
+
+impl SliceExt for [Attribute] {
+    /// # Errors
+    ///
+    /// - There are multiple specified attributes.
+    /// - The `Attribute::tokens` field of the specified attribute is not empty.
+    fn position_exact(&self, ident: &str) -> Result<Option<usize>> {
+        self.iter()
+            .try_fold((0, None), |(i, mut prev), attr| {
+                if attr.path.is_ident(ident) {
+                    if prev.replace(i).is_some() {
+                        bail!(attr, "duplicate #[{}] attribute", ident);
+                    }
+                    parse_as_empty(&attr.tokens)?;
+                }
+                Ok((i + 1, prev))
+            })
+            .map(|(_, pos)| pos)
+    }
+
+    fn find(&self, ident: &str) -> Option<&Attribute> {
+        self.iter().position(|attr| attr.path.is_ident(ident)).map(|i| &self[i])
+    }
+}
+
+pub(crate) trait ParseBufferExt<'a> {
+    fn parenthesized(self) -> Result<ParseBuffer<'a>>;
+}
+
+impl<'a> ParseBufferExt<'a> for ParseStream<'a> {
+    fn parenthesized(self) -> Result<ParseBuffer<'a>> {
+        let content;
+        let _: token::Paren = syn::parenthesized!(content in self);
+        Ok(content)
+    }
+}
+
+impl<'a> ParseBufferExt<'a> for ParseBuffer<'a> {
+    fn parenthesized(self) -> Result<ParseBuffer<'a>> {
+        let content;
+        let _: token::Paren = syn::parenthesized!(content in self);
+        Ok(content)
+    }
+}
+
+// =================================================================================================
+// visitors
+
+// Replace `self`/`Self` with `__self`/`self_ty`.
+// Based on:
+// - https://github.com/dtolnay/async-trait/blob/0.1.35/src/receiver.rs
+// - https://github.com/dtolnay/async-trait/commit/6029cbf375c562ca98fa5748e9d950a8ff93b0e7
+
+pub(crate) struct ReplaceReceiver<'a>(pub(crate) &'a TypePath);
+
+impl ReplaceReceiver<'_> {
+    fn self_ty(&self, span: Span) -> TypePath {
+        respan(self.0, span)
+    }
+
+    fn self_to_qself(&self, qself: &mut Option<QSelf>, path: &mut Path) {
+        if path.leading_colon.is_some() {
+            return;
+        }
+
+        let first = &path.segments[0];
+        if first.ident != "Self" || !first.arguments.is_empty() {
+            return;
+        }
+
+        if path.segments.len() == 1 {
+            self.self_to_expr_path(path);
+            return;
+        }
+
+        let span = first.ident.span();
+        *qself = Some(QSelf {
+            lt_token: Token![<](span),
+            ty: Box::new(self.self_ty(span).into()),
+            position: 0,
+            as_token: None,
+            gt_token: Token![>](span),
+        });
+
+        path.leading_colon = Some(**path.segments.pairs().next().unwrap().punct().unwrap());
+
+        let segments = mem::replace(&mut path.segments, Punctuated::new());
+        path.segments = segments.into_pairs().skip(1).collect();
+    }
+
+    fn self_to_expr_path(&self, path: &mut Path) {
+        if path.leading_colon.is_some() {
+            return;
+        }
+
+        let first = &path.segments[0];
+        if first.ident != "Self" || !first.arguments.is_empty() {
+            return;
+        }
+
+        let self_ty = self.self_ty(first.ident.span());
+        let variant = mem::replace(path, self_ty.path);
+        for segment in &mut path.segments {
+            if let PathArguments::AngleBracketed(bracketed) = &mut segment.arguments {
+                if bracketed.colon2_token.is_none() && !bracketed.args.is_empty() {
+                    bracketed.colon2_token = Some(<Token![::]>::default());
+                }
+            }
+        }
+        if variant.segments.len() > 1 {
+            path.segments.push_punct(<Token![::]>::default());
+            path.segments.extend(variant.segments.into_pairs().skip(1));
+        }
+    }
+
+    fn visit_token_stream(&self, tokens: &mut TokenStream) -> bool {
+        let mut out = Vec::new();
+        let mut modified = false;
+        let mut iter = tokens.clone().into_iter().peekable();
+        while let Some(tt) = iter.next() {
+            match tt {
+                TokenTree::Ident(mut ident) => {
+                    modified |= prepend_underscore_to_self(&mut ident);
+                    if ident == "Self" {
+                        modified = true;
+                        let self_ty = self.self_ty(ident.span());
+                        match iter.peek() {
+                            Some(TokenTree::Punct(p))
+                                if p.as_char() == ':' && p.spacing() == Spacing::Joint =>
+                            {
+                                let next = iter.next().unwrap();
+                                match iter.peek() {
+                                    Some(TokenTree::Punct(p)) if p.as_char() == ':' => {
+                                        let span = ident.span();
+                                        out.extend(quote_spanned!(span=> <#self_ty>));
+                                    }
+                                    _ => out.extend(quote!(#self_ty)),
+                                }
+                                out.push(next);
+                            }
+                            _ => out.extend(quote!(#self_ty)),
+                        }
+                    } else {
+                        out.push(TokenTree::Ident(ident));
+                    }
+                }
+                TokenTree::Group(group) => {
+                    let mut content = group.stream();
+                    modified |= self.visit_token_stream(&mut content);
+                    let mut new = Group::new(group.delimiter(), content);
+                    new.set_span(group.span());
+                    out.push(TokenTree::Group(new));
+                }
+                other => out.push(other),
+            }
+        }
+        if modified {
+            *tokens = TokenStream::from_iter(out);
+        }
+        modified
+    }
+}
+
+impl VisitMut for ReplaceReceiver<'_> {
+    // `Self` -> `Receiver`
+    fn visit_type_mut(&mut self, ty: &mut Type) {
+        if let Type::Path(node) = ty {
+            if node.qself.is_none() && node.path.is_ident("Self") {
+                *ty = self.self_ty(node.path.segments[0].ident.span()).into();
+            } else {
+                self.visit_type_path_mut(node);
+            }
+        } else {
+            visit_mut::visit_type_mut(self, ty);
+        }
+    }
+
+    // `Self::Assoc` -> `<Receiver>::Assoc`
+    fn visit_type_path_mut(&mut self, ty: &mut TypePath) {
+        if ty.qself.is_none() {
+            self.self_to_qself(&mut ty.qself, &mut ty.path);
+        }
+        visit_mut::visit_type_path_mut(self, ty);
+    }
+
+    // `Self::method` -> `<Receiver>::method`
+    fn visit_expr_path_mut(&mut self, expr: &mut ExprPath) {
+        if expr.qself.is_none() {
+            self.self_to_qself(&mut expr.qself, &mut expr.path);
+        }
+        visit_mut::visit_expr_path_mut(self, expr);
+    }
+
+    fn visit_expr_struct_mut(&mut self, expr: &mut ExprStruct) {
+        self.self_to_expr_path(&mut expr.path);
+        visit_mut::visit_expr_struct_mut(self, expr);
+    }
+
+    fn visit_pat_path_mut(&mut self, pat: &mut PatPath) {
+        if pat.qself.is_none() {
+            self.self_to_qself(&mut pat.qself, &mut pat.path);
+        }
+        visit_mut::visit_pat_path_mut(self, pat);
+    }
+
+    fn visit_pat_struct_mut(&mut self, pat: &mut PatStruct) {
+        self.self_to_expr_path(&mut pat.path);
+        visit_mut::visit_pat_struct_mut(self, pat);
+    }
+
+    fn visit_pat_tuple_struct_mut(&mut self, pat: &mut PatTupleStruct) {
+        self.self_to_expr_path(&mut pat.path);
+        visit_mut::visit_pat_tuple_struct_mut(self, pat);
+    }
+
+    fn visit_path_mut(&mut self, path: &mut Path) {
+        if path.segments.len() == 1 {
+            // Replace `self`, but not `self::function`.
+            prepend_underscore_to_self(&mut path.segments[0].ident);
+        }
+        for segment in &mut path.segments {
+            self.visit_path_arguments_mut(&mut segment.arguments);
+        }
+    }
+
+    fn visit_item_mut(&mut self, item: &mut Item) {
+        match item {
+            // Visit `macro_rules!` because locally defined macros can refer to `self`.
+            Item::Macro(item) if item.mac.path.is_ident("macro_rules") => {
+                self.visit_macro_mut(&mut item.mac);
+            }
+            // Otherwise, do not recurse into nested items.
+            _ => {}
+        }
+    }
+
+    fn visit_macro_mut(&mut self, mac: &mut Macro) {
+        // We can't tell in general whether `self` inside a macro invocation
+        // refers to the self in the argument list or a different self
+        // introduced within the macro. Heuristic: if the macro input contains
+        // `fn`, then `self` is more likely to refer to something other than the
+        // outer function's self argument.
+        if !contains_fn(mac.tokens.clone()) {
+            self.visit_token_stream(&mut mac.tokens);
+        }
+    }
+}
+
+fn contains_fn(tokens: TokenStream) -> bool {
+    tokens.into_iter().any(|tt| match tt {
+        TokenTree::Ident(ident) => ident == "fn",
+        TokenTree::Group(group) => contains_fn(group.stream()),
+        _ => false,
+    })
+}
+
+pub(crate) fn prepend_underscore_to_self(ident: &mut Ident) -> bool {
+    let modified = ident == "self";
+    if modified {
+        *ident = Ident::new("__self", ident.span());
+    }
+    modified
+}
diff --git a/third_party/rust/pin-project-lite/.cargo-checksum.json b/third_party/rust/pin-project-lite/.cargo-checksum.json
new file mode 100644
index 0000000000..249c55e4be
--- /dev/null
+++ b/third_party/rust/pin-project-lite/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGELOG.md":"0da6eac8d8957a8aea735942d2e6e226b5cb178a363fe77b87c23272f2e63b1c","Cargo.toml":"b0b0099d5e8af1ffbe68c0b4e367a00602dbf1acab35f8c956129918b17a5425","LICENSE-APACHE":"0d542e0c8804e39aa7f37eb00da5a762149dc682d7829451287e11b938e94594","LICENSE-MIT":"23f18e03dc49df91622fe2a76176497404e46ced8a715d9d2b67a7446571cca3","README.md":"609412221520fc16f47e76131927e4dd11aef38f7c69d92a1116130654f0ee90","src/lib.rs":"7b76a04ae98aa1e9ee85b9a2e1f054384b39df74cdfb375ff46649af8ec4b5b3","tests/README.md":"71fc84264ec08d2b7f1c74c1ba5140a376121b72145cc630b616e6f2536aeafa","tests/auxiliary/mod.rs":"7e263e987e09b77e384f734384a00a71c5b70230bb1b5376446ef003a8da9372","tests/compiletest.rs":"f764ff03c73c8a21c35ee30cf851b9266b2987e88d646d9bd086fc71944eb945","tests/drop_order.rs":"2cb31a8cd5cf4d9a4ba9faf25f99f0e85f9bd7b4778649f843d9c617c6af43fc","tests/expand/default/enum.expanded.rs":"c4db8e05cfe6eab3be39301abf77689f79fdaff52605350a2aee464b2756180e","tests/expand/default/enum.rs":"493d5752c4baa87ed4c48bd41b8e5e263fd5e3f43c4f9195818ef6d26951f63e","tests/expand/default/struct.expanded.rs":"c158632984eaf6ab8ae60b76ff2bf32b20ba10a3cbc4237c9a6ea28c614cdb01","tests/expand/default/struct.rs":"5a6e57d9b6d00cfd4e1e69f37ce0c9d5165a21230d0363f0791665b1015870ce","tests/expand/multifields/enum.expanded.rs":"8bba6a5a2279469bf94c486a6efb2f8c9ed965b716d66ac0660662e11ca0bddb","tests/expand/multifields/enum.rs":"9c79270a7d6d1d42cf8194b579d79e7d44a3fd003243742f0a568ecf0a4f3be3","tests/expand/multifields/struct.expanded.rs":"46ac58981d4ee4eba61b879ba62b313ceac59f9a223ae4984450f72a9173cbd2","tests/expand/multifields/struct.rs":"17f0447d522d48f14d516808bd66baacebdf3ac38188df72f649702a893cda68","tests/expand/naming/enum-all.expanded.rs":"c4db8e05cfe6eab3be39301abf77689f79fdaff52605350a2aee464b2756180e","tests/expand/naming/enum-all.rs":"493d5752c4baa87ed4c48bd41b8e5e263fd5e3f43c4f9195818ef6d26951f63e","tests/expand/naming/enum-mut.expanded.rs":"ce1a12428d3906c8d98516b3afdcbbbda64776e2f0c039e90f3de8f734ab1878","tests/expand/naming/enum-mut.rs":"c1ff4ade049ebbceb2acb99dbc1af5db14de3ba9710ea1ff1b64348766a9e080","tests/expand/naming/enum-none.expanded.rs":"cf8ea074b8079af453a2f98e2217704e96174433e4ac0e07577f9242ad3d5de2","tests/expand/naming/enum-none.rs":"ff22be4ecf4168e2bc68ab249a0ed809a37e3b8e840ef8977d24209ef28ac839","tests/expand/naming/enum-ref.expanded.rs":"277e9642e49f4dc312ea09b4d9f8012994662f565529865102be0fe1657c2b13","tests/expand/naming/enum-ref.rs":"394cbd5d872449e9226cd0834ce7117c395a582567584218dabbef4eb2c1fbac","tests/expand/naming/struct-all.expanded.rs":"807c74c57928e068725fa8272a1d1c671401ed213ce8abf1a405a35b1fb47673","tests/expand/naming/struct-all.rs":"c13c0aacee85b8fca58f85d2d75d2e3907b3e7642f8710ed8c8e54d6015881cc","tests/expand/naming/struct-mut.expanded.rs":"f08b34f7d49ad45ae0a1ae8b64995d63e7e4eed2910a912f6c622a0b8e410b89","tests/expand/naming/struct-mut.rs":"9a7752a6d30e0b7033f3577a72676676900a642cdaf59f942179d1f2a8ba2bb0","tests/expand/naming/struct-none.expanded.rs":"c158632984eaf6ab8ae60b76ff2bf32b20ba10a3cbc4237c9a6ea28c614cdb01","tests/expand/naming/struct-none.rs":"5a6e57d9b6d00cfd4e1e69f37ce0c9d5165a21230d0363f0791665b1015870ce","tests/expand/naming/struct-ref.expanded.rs":"dabc3fda847ab2f4e4ca0ec6f6dc4da43f8de087117dcafb3c15780cebc7af45","tests/expand/naming/struct-ref.rs":"33c4fd344b65650dee44087ada31d4b5acd9d122123360fb7d41718c46699574","tests/expand/pinned_drop/enum.expanded.rs":"56d709a0cfc0c951fe303bf2b034e7fae4fc5271b9a11ade9c6a9c20c89471b3","tests/expand/pinned_drop/enum.rs":"d7e087b6852338fabe7edf39529c8f893a426b4d0c6aba2d2a6be0d95f739cdc","tests/expand/pinned_drop/struct.expanded.rs":"c9b26224339f126ce5f0d36cd8d6c6e84970bf39b94dc11bc42743ad5bdba6be","tests/expand/pinned_drop/struct.rs":"164a25e12b9898c093b5dee2c47a40dd549e6f49ba1c6bb22f4e4c4b98fe76b2","tests/expand/pub/enum.expanded.rs":"56c81c0535f8fb9b83662fc3753f7c07b96eb12392669bb1ae23ffc82b7c4a2c","tests/expand/pub/enum.rs":"5b60dd354a489b0326f5c4f1026b89d1471ddbb45906bc3046a65425c4e5e160","tests/expand/pub/struct.expanded.rs":"525c52bf7185493046618ee0dc1b18bdc0c0a56383f5c7b11c98738211d024a7","tests/expand/pub/struct.rs":"15b7940ce0ad1d5d133dde1870319f2f96a000bfcf29508b8cce1a62876cbd80","tests/expandtest.rs":"898df948c7ee82df0e0823cbde16ccc2b9dba455475665e6d2c7c0a84493e9fb","tests/include/basic.rs":"9e399b682bc74c899d26924c2cab52a911f7392e29300defb6521e561fafafe4","tests/lint.rs":"513ffda15a1e8e64076e8a1b7db709d5de8eebaf7952839974056e99afedde82","tests/proper_unpin.rs":"57a9e8c9029ba7920ec23670b66758916e067c9cecf4d3f8b0035bec25cdb570","tests/test.rs":"8d0ee300af17535dc7fd488433630911ddc3147a3e3ccf0b9dce9f0ccdb10dc3","tests/ui/pin_project/conflict-drop.rs":"55e6809b5f59dd81e32c2c89b742c0c76db6b099a1d2621e5b882c0d20f92837","tests/ui/pin_project/conflict-drop.stderr":"d22314903c031c1dad5fba81b8819fd9a1459ed4f750534032eaa3296db9e4ac","tests/ui/pin_project/conflict-unpin.rs":"51b3b6720fa581b63167d6ac941a1ea1bf739b09954931b2bc2f7abe2d934f26","te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\ No newline at end of file
diff --git a/third_party/rust/pin-project-lite/CHANGELOG.md b/third_party/rust/pin-project-lite/CHANGELOG.md
new file mode 100644
index 0000000000..127e467989
--- /dev/null
+++ b/third_party/rust/pin-project-lite/CHANGELOG.md
@@ -0,0 +1,222 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+This project adheres to [Semantic Versioning](https://semver.org).
+
+<!--
+Note: In this file, do not use the hard wrap in the middle of a sentence for compatibility with GitHub comment style markdown rendering.
+-->
+
+## [Unreleased]
+
+## [0.2.9] - 2022-04-26
+
+- Improve compile time of `pin_project!` calls. (#71, thanks @nnethercote)
+
+## [0.2.8] - 2021-12-31
+
+- Fix handling of trailing commas in `PinnedDrop` impl. ([#64](https://github.com/taiki-e/pin-project-lite/pull/64), thanks @Michael-J-Ward)
+
+## [0.2.7] - 2021-06-26
+
+- [Support custom Drop implementation.](https://github.com/taiki-e/pin-project-lite/pull/25) See [#25](https://github.com/taiki-e/pin-project-lite/pull/25) for details.
+
+## [0.2.6] - 2021-03-04
+
+- Support item attributes in any order. ([#57](https://github.com/taiki-e/pin-project-lite/pull/57), thanks @SabrinaJewson)
+
+## [0.2.5] - 2021-03-02
+
+- [Prepare for removal of `safe_packed_borrows` lint.](https://github.com/taiki-e/pin-project-lite/pull/55) See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+## [0.2.4] - 2021-01-11
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- Add `project_replace`. ([#43](https://github.com/taiki-e/pin-project-lite/pull/43), thanks @Marwes)
+
+## [0.2.3] - 2021-01-09
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Suppress `clippy::unknown_clippy_lints` lint in generated code.](https://github.com/taiki-e/pin-project-lite/pull/47)
+
+## [0.2.2] - 2021-01-09
+
+**Note:** This release has been yanked.** See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Suppress `clippy::ref_option_ref` lint in generated code.](https://github.com/taiki-e/pin-project-lite/pull/45)
+
+## [0.2.1] - 2021-01-05
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- Exclude unneeded files from crates.io.
+
+## [0.2.0] - 2020-11-13
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [`pin_project!` macro now supports enums.](https://github.com/taiki-e/pin-project-lite/pull/28)
+
+  To use `pin_project!` on enums, you need to name the projection type returned from the method.
+
+  ```rust
+  use pin_project_lite::pin_project;
+  use std::pin::Pin;
+
+  pin_project! {
+      #[project = EnumProj]
+      enum Enum<T, U> {
+          Variant { #[pin] pinned: T, unpinned: U },
+      }
+  }
+
+  impl<T, U> Enum<T, U> {
+      fn method(self: Pin<&mut Self>) {
+          match self.project() {
+              EnumProj::Variant { pinned, unpinned } => {
+                  let _: Pin<&mut T> = pinned;
+                  let _: &mut U = unpinned;
+              }
+          }
+      }
+  }
+  ```
+
+- [Support naming the projection types.](https://github.com/taiki-e/pin-project-lite/pull/28)
+
+  By passing an attribute with the same name as the method, you can name the projection type returned from the method:
+
+  ```rust
+  use pin_project_lite::pin_project;
+  use std::pin::Pin;
+
+  pin_project! {
+      #[project = StructProj]
+      struct Struct<T> {
+          #[pin]
+          field: T,
+      }
+  }
+
+  fn func<T>(x: Pin<&mut Struct<T>>) {
+      let StructProj { field } = x.project();
+      let _: Pin<&mut T> = field;
+  }
+  ```
+
+## [0.1.12] - 2021-03-02
+
+- [Prepare for removal of `safe_packed_borrows` lint.](https://github.com/taiki-e/pin-project-lite/pull/55) See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+## [0.1.11] - 2020-10-20
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- Suppress `clippy::redundant_pub_crate` lint in generated code.
+
+- Documentation improvements.
+
+## [0.1.10] - 2020-10-01
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- Suppress `drop_bounds` lint, which will be added to rustc in the future. See [taiki-e/pin-project#272](https://github.com/taiki-e/pin-project/issues/272) for more details.
+
+## [0.1.9] - 2020-09-29
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Fix trailing comma support in generics.](https://github.com/taiki-e/pin-project-lite/pull/32)
+
+## [0.1.8] - 2020-09-26
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Fix compatibility of generated code with `forbid(future_incompatible)`.](https://github.com/taiki-e/pin-project-lite/pull/30)
+
+  Note: This does not guarantee compatibility with `forbid(future_incompatible)` in the future.
+  If rustc adds a new lint, we may not be able to keep this.
+
+## [0.1.7] - 2020-06-04
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Support `?Sized` bounds in where clauses.](https://github.com/taiki-e/pin-project-lite/pull/22)
+
+- [Fix lifetime inference error when an associated type is used in fields.](https://github.com/taiki-e/pin-project-lite/pull/20)
+
+- Suppress `clippy::used_underscore_binding` lint in generated code.
+
+- Documentation improvements.
+
+## [0.1.6] - 2020-05-31
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Support lifetime bounds in where clauses.](https://github.com/taiki-e/pin-project-lite/pull/18)
+
+- Documentation improvements.
+
+## [0.1.5] - 2020-05-07
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Support overwriting the name of `core` crate.](https://github.com/taiki-e/pin-project-lite/pull/14)
+
+## [0.1.4] - 2020-01-20
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Support ?Sized bounds in generic parameters.](https://github.com/taiki-e/pin-project-lite/pull/9)
+
+## [0.1.3] - 2020-01-20
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [Support lifetime bounds in generic parameters.](https://github.com/taiki-e/pin-project-lite/pull/7)
+
+## [0.1.2] - 2020-01-05
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- Support recognizing default generic parameters. ([#6](https://github.com/taiki-e/pin-project-lite/pull/6), thanks @kennytm)
+
+## [0.1.1] - 2019-11-15
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+- [`pin_project!` macro now determines the visibility of the projection type/method is based on the original type.](https://github.com/taiki-e/pin-project-lite/pull/5)
+
+## [0.1.0] - 2019-10-22
+
+**Note:** This release has been yanked. See [#55](https://github.com/taiki-e/pin-project-lite/pull/55) for details.
+
+Initial release
+
+[Unreleased]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.9...HEAD
+[0.2.9]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.8...v0.2.9
+[0.2.8]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.7...v0.2.8
+[0.2.7]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.6...v0.2.7
+[0.2.6]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.5...v0.2.6
+[0.2.5]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.4...v0.2.5
+[0.2.4]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.3...v0.2.4
+[0.2.3]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.2...v0.2.3
+[0.2.2]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.1...v0.2.2
+[0.2.1]: https://github.com/taiki-e/pin-project-lite/compare/v0.2.0...v0.2.1
+[0.2.0]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.11...v0.2.0
+[0.1.12]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.11...v0.1.12
+[0.1.11]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.10...v0.1.11
+[0.1.10]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.9...v0.1.10
+[0.1.9]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.8...v0.1.9
+[0.1.8]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.7...v0.1.8
+[0.1.7]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.6...v0.1.7
+[0.1.6]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.5...v0.1.6
+[0.1.5]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.4...v0.1.5
+[0.1.4]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.3...v0.1.4
+[0.1.3]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.2...v0.1.3
+[0.1.2]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.1...v0.1.2
+[0.1.1]: https://github.com/taiki-e/pin-project-lite/compare/v0.1.0...v0.1.1
+[0.1.0]: https://github.com/taiki-e/pin-project-lite/releases/tag/v0.1.0
diff --git a/third_party/rust/pin-project-lite/Cargo.toml b/third_party/rust/pin-project-lite/Cargo.toml
new file mode 100644
index 0000000000..8a9436d877
--- /dev/null
+++ b/third_party/rust/pin-project-lite/Cargo.toml
@@ -0,0 +1,45 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+rust-version = "1.37"
+name = "pin-project-lite"
+version = "0.2.9"
+exclude = [
+    "/.*",
+    "/tools",
+]
+description = """
+A lightweight version of pin-project written with declarative macros.
+"""
+keywords = [
+    "pin",
+    "macros",
+]
+categories = [
+    "no-std",
+    "rust-patterns",
+]
+license = "Apache-2.0 OR MIT"
+repository = "https://github.com/taiki-e/pin-project-lite"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dev-dependencies.rustversion]
+version = "1"
+
+[dev-dependencies.static_assertions]
+version = "1"
+
+[dev-dependencies.trybuild]
+version = "1.0.49"
diff --git a/third_party/rust/pin-project-lite/LICENSE-APACHE b/third_party/rust/pin-project-lite/LICENSE-APACHE
new file mode 100644
index 0000000000..f433b1a53f
--- /dev/null
+++ b/third_party/rust/pin-project-lite/LICENSE-APACHE
@@ -0,0 +1,177 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+   END OF TERMS AND CONDITIONS
diff --git a/third_party/rust/pin-project-lite/LICENSE-MIT b/third_party/rust/pin-project-lite/LICENSE-MIT
new file mode 100644
index 0000000000..31aa79387f
--- /dev/null
+++ b/third_party/rust/pin-project-lite/LICENSE-MIT
@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/pin-project-lite/README.md b/third_party/rust/pin-project-lite/README.md
new file mode 100644
index 0000000000..78adb7e364
--- /dev/null
+++ b/third_party/rust/pin-project-lite/README.md
@@ -0,0 +1,125 @@
+# pin-project-lite
+
+[![crates.io](https://img.shields.io/crates/v/pin-project-lite?style=flat-square&logo=rust)](https://crates.io/crates/pin-project-lite)
+[![docs.rs](https://img.shields.io/badge/docs.rs-pin--project--lite-blue?style=flat-square)](https://docs.rs/pin-project-lite)
+[![license](https://img.shields.io/badge/license-Apache--2.0_OR_MIT-blue?style=flat-square)](#license)
+[![rustc](https://img.shields.io/badge/rustc-1.37+-blue?style=flat-square&logo=rust)](https://www.rust-lang.org)
+[![build status](https://img.shields.io/github/workflow/status/taiki-e/pin-project-lite/CI/main?style=flat-square&logo=github)](https://github.com/taiki-e/pin-project-lite/actions)
+
+A lightweight version of [pin-project] written with declarative macros.
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+pin-project-lite = "0.2"
+```
+
+*Compiler support: requires rustc 1.37+*
+
+## Examples
+
+[`pin_project!`] macro creates a projection type covering all the fields of
+struct.
+
+```rust
+use std::pin::Pin;
+
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+impl<T, U> Struct<T, U> {
+    fn method(self: Pin<&mut Self>) {
+        let this = self.project();
+        let _: Pin<&mut T> = this.pinned; // Pinned reference to the field
+        let _: &mut U = this.unpinned; // Normal reference to the field
+    }
+}
+```
+
+To use [`pin_project!`] on enums, you need to name the projection type
+returned from the method.
+
+```rust
+use std::pin::Pin;
+
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = EnumProj]
+    enum Enum<T, U> {
+        Variant { #[pin] pinned: T, unpinned: U },
+    }
+}
+
+impl<T, U> Enum<T, U> {
+    fn method(self: Pin<&mut Self>) {
+        match self.project() {
+            EnumProj::Variant { pinned, unpinned } => {
+                let _: Pin<&mut T> = pinned;
+                let _: &mut U = unpinned;
+            }
+        }
+    }
+}
+```
+
+## [pin-project] vs pin-project-lite
+
+Here are some similarities and differences compared to [pin-project].
+
+### Similar: Safety
+
+pin-project-lite guarantees safety in much the same way as [pin-project].
+Both are completely safe unless you write other unsafe code.
+
+### Different: Minimal design
+
+This library does not tackle as expansive of a range of use cases as
+[pin-project] does. If your use case is not already covered, please use
+[pin-project].
+
+### Different: No proc-macro related dependencies
+
+This is the **only** reason to use this crate. However, **if you already
+have proc-macro related dependencies in your crate's dependency graph, there
+is no benefit from using this crate.** (Note: There is almost no difference
+in the amount of code generated between [pin-project] and pin-project-lite.)
+
+### Different: No useful error messages
+
+This macro does not handle any invalid input. So error messages are not to
+be useful in most cases. If you do need useful error messages, then upon
+error you can pass the same input to [pin-project] to receive a helpful
+description of the compile error.
+
+### Different: No support for custom Unpin implementation
+
+pin-project supports this by [`UnsafeUnpin`][unsafe-unpin] and [`!Unpin`][not-unpin].
+
+### Different: No support for tuple structs and tuple variants
+
+pin-project supports this.
+
+[`pin_project!`]: https://docs.rs/pin-project-lite/0.2/pin_project_lite/macro.pin_project.html
+[not-unpin]: https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#unpin
+[pin-project]: https://github.com/taiki-e/pin-project
+[unsafe-unpin]: https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#unsafeunpin
+
+## License
+
+Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
+[MIT license](LICENSE-MIT) at your option.
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall
+be dual licensed as above, without any additional terms or conditions.
diff --git a/third_party/rust/pin-project-lite/src/lib.rs b/third_party/rust/pin-project-lite/src/lib.rs
new file mode 100644
index 0000000000..f5ecc990d6
--- /dev/null
+++ b/third_party/rust/pin-project-lite/src/lib.rs
@@ -0,0 +1,1559 @@
+//! A lightweight version of [pin-project] written with declarative macros.
+//!
+//! # Examples
+//!
+//! [`pin_project!`] macro creates a projection type covering all the fields of struct.
+//!
+//! ```rust
+//! use std::pin::Pin;
+//!
+//! use pin_project_lite::pin_project;
+//!
+//! pin_project! {
+//!     struct Struct<T, U> {
+//!         #[pin]
+//!         pinned: T,
+//!         unpinned: U,
+//!     }
+//! }
+//!
+//! impl<T, U> Struct<T, U> {
+//!     fn method(self: Pin<&mut Self>) {
+//!         let this = self.project();
+//!         let _: Pin<&mut T> = this.pinned; // Pinned reference to the field
+//!         let _: &mut U = this.unpinned; // Normal reference to the field
+//!     }
+//! }
+//! ```
+//!
+//! To use [`pin_project!`] on enums, you need to name the projection type
+//! returned from the method.
+//!
+//! ```rust
+//! use std::pin::Pin;
+//!
+//! use pin_project_lite::pin_project;
+//!
+//! pin_project! {
+//!     #[project = EnumProj]
+//!     enum Enum<T, U> {
+//!         Variant { #[pin] pinned: T, unpinned: U },
+//!     }
+//! }
+//!
+//! impl<T, U> Enum<T, U> {
+//!     fn method(self: Pin<&mut Self>) {
+//!         match self.project() {
+//!             EnumProj::Variant { pinned, unpinned } => {
+//!                 let _: Pin<&mut T> = pinned;
+//!                 let _: &mut U = unpinned;
+//!             }
+//!         }
+//!     }
+//! }
+//! ```
+//!
+//! # [pin-project] vs pin-project-lite
+//!
+//! Here are some similarities and differences compared to [pin-project].
+//!
+//! ## Similar: Safety
+//!
+//! pin-project-lite guarantees safety in much the same way as [pin-project].
+//! Both are completely safe unless you write other unsafe code.
+//!
+//! ## Different: Minimal design
+//!
+//! This library does not tackle as expansive of a range of use cases as
+//! [pin-project] does. If your use case is not already covered, please use
+//! [pin-project].
+//!
+//! ## Different: No proc-macro related dependencies
+//!
+//! This is the **only** reason to use this crate. However, **if you already
+//! have proc-macro related dependencies in your crate's dependency graph, there
+//! is no benefit from using this crate.** (Note: There is almost no difference
+//! in the amount of code generated between [pin-project] and pin-project-lite.)
+//!
+//! ## Different: No useful error messages
+//!
+//! This macro does not handle any invalid input. So error messages are not to
+//! be useful in most cases. If you do need useful error messages, then upon
+//! error you can pass the same input to [pin-project] to receive a helpful
+//! description of the compile error.
+//!
+//! ## Different: No support for custom Unpin implementation
+//!
+//! pin-project supports this by [`UnsafeUnpin`][unsafe-unpin] and [`!Unpin`][not-unpin].
+//!
+//! ## Different: No support for tuple structs and tuple variants
+//!
+//! pin-project supports this.
+//!
+//! [not-unpin]: https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#unpin
+//! [pin-project]: https://github.com/taiki-e/pin-project
+//! [unsafe-unpin]: https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#unsafeunpin
+
+#![no_std]
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_variables)
+    )
+))]
+#![warn(rust_2018_idioms, single_use_lifetimes, unreachable_pub)]
+#![warn(clippy::default_trait_access, clippy::wildcard_imports)]
+
+/// A macro that creates a projection type covering all the fields of struct.
+///
+/// This macro creates a projection type according to the following rules:
+///
+/// - For the field that uses `#[pin]` attribute, makes the pinned reference to the field.
+/// - For the other fields, makes the unpinned reference to the field.
+///
+/// And the following methods are implemented on the original type:
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// # type Projection<'a> = &'a ();
+/// # type ProjectionRef<'a> = &'a ();
+/// # trait Dox {
+/// fn project(self: Pin<&mut Self>) -> Projection<'_>;
+/// fn project_ref(self: Pin<&Self>) -> ProjectionRef<'_>;
+/// # }
+/// ```
+///
+/// By passing an attribute with the same name as the method to the macro,
+/// you can name the projection type returned from the method. This allows you
+/// to use pattern matching on the projected types.
+///
+/// ```rust
+/// # use pin_project_lite::pin_project;
+/// # use std::pin::Pin;
+/// pin_project! {
+///     #[project = EnumProj]
+///     enum Enum<T> {
+///         Variant { #[pin] field: T },
+///     }
+/// }
+///
+/// impl<T> Enum<T> {
+///     fn method(self: Pin<&mut Self>) {
+///         let this: EnumProj<'_, T> = self.project();
+///         match this {
+///             EnumProj::Variant { field } => {
+///                 let _: Pin<&mut T> = field;
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// By passing the `#[project_replace = MyProjReplace]` attribute you may create an additional
+/// method which allows the contents of `Pin<&mut Self>` to be replaced while simultaneously moving
+/// out all unpinned fields in `Self`.
+///
+/// ```rust
+/// # use std::pin::Pin;
+/// # type MyProjReplace = ();
+/// # trait Dox {
+/// fn project_replace(self: Pin<&mut Self>, replacement: Self) -> MyProjReplace;
+/// # }
+/// ```
+///
+/// Also, note that the projection types returned by `project` and `project_ref` have
+/// an additional lifetime at the beginning of generics.
+///
+/// ```text
+/// let this: EnumProj<'_, T> = self.project();
+///                    ^^
+/// ```
+///
+/// The visibility of the projected types and projection methods is based on the
+/// original type. However, if the visibility of the original type is `pub`, the
+/// visibility of the projected types and the projection methods is downgraded
+/// to `pub(crate)`.
+///
+/// # Safety
+///
+/// `pin_project!` macro guarantees safety in much the same way as [pin-project] crate.
+/// Both are completely safe unless you write other unsafe code.
+///
+/// See [pin-project] crate for more details.
+///
+/// # Examples
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project_lite::pin_project;
+///
+/// pin_project! {
+///     struct Struct<T, U> {
+///         #[pin]
+///         pinned: T,
+///         unpinned: U,
+///     }
+/// }
+///
+/// impl<T, U> Struct<T, U> {
+///     fn method(self: Pin<&mut Self>) {
+///         let this = self.project();
+///         let _: Pin<&mut T> = this.pinned; // Pinned reference to the field
+///         let _: &mut U = this.unpinned; // Normal reference to the field
+///     }
+/// }
+/// ```
+///
+/// To use `pin_project!` on enums, you need to name the projection type
+/// returned from the method.
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project_lite::pin_project;
+///
+/// pin_project! {
+///     #[project = EnumProj]
+///     enum Enum<T> {
+///         Struct {
+///             #[pin]
+///             field: T,
+///         },
+///         Unit,
+///     }
+/// }
+///
+/// impl<T> Enum<T> {
+///     fn method(self: Pin<&mut Self>) {
+///         match self.project() {
+///             EnumProj::Struct { field } => {
+///                 let _: Pin<&mut T> = field;
+///             }
+///             EnumProj::Unit => {}
+///         }
+///     }
+/// }
+/// ```
+///
+/// If you want to call the `project()` method multiple times or later use the
+/// original [`Pin`] type, it needs to use [`.as_mut()`][`Pin::as_mut`] to avoid
+/// consuming the [`Pin`].
+///
+/// ```rust
+/// use std::pin::Pin;
+///
+/// use pin_project_lite::pin_project;
+///
+/// pin_project! {
+///     struct Struct<T> {
+///         #[pin]
+///         field: T,
+///     }
+/// }
+///
+/// impl<T> Struct<T> {
+///     fn call_project_twice(mut self: Pin<&mut Self>) {
+///         // `project` consumes `self`, so reborrow the `Pin<&mut Self>` via `as_mut`.
+///         self.as_mut().project();
+///         self.as_mut().project();
+///     }
+/// }
+/// ```
+///
+/// # `!Unpin`
+///
+/// If you want to ensure that [`Unpin`] is not implemented, use `#[pin]`
+/// attribute for a [`PhantomPinned`] field.
+///
+/// ```rust
+/// use std::marker::PhantomPinned;
+///
+/// use pin_project_lite::pin_project;
+///
+/// pin_project! {
+///     struct Struct<T> {
+///         field: T,
+///         #[pin] // <------ This `#[pin]` is required to make `Struct` to `!Unpin`.
+///         _pin: PhantomPinned,
+///     }
+/// }
+/// ```
+///
+/// Note that using [`PhantomPinned`] without `#[pin]` attribute has no effect.
+///
+/// [`PhantomPinned`]: core::marker::PhantomPinned
+/// [`Pin::as_mut`]: core::pin::Pin::as_mut
+/// [`Pin`]: core::pin::Pin
+/// [pin-project]: https://github.com/taiki-e/pin-project
+#[macro_export]
+macro_rules! pin_project {
+    ($($tt:tt)*) => {
+        $crate::__pin_project_internal! {
+            [][][][]
+            $($tt)*
+        }
+    };
+}
+
+// limitations:
+// - no support for tuple structs and tuple variant (wontfix).
+// - no support for multiple trait/lifetime bounds.
+// - no support for `Self` in where clauses. (wontfix)
+// - no support for overlapping lifetime names. (wontfix)
+// - no interoperability with other field attributes.
+// - no useful error messages. (wontfix)
+// etc...
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_expand {
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$proj_vis:vis]
+        [$(#[$attrs:meta])* $vis:vis $struct_ty_ident:ident $ident:ident]
+        [$($def_generics:tt)*]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $($body_data:tt)*
+        }
+        $(impl $($pinned_drop:tt)*)?
+    ) => {
+        $crate::__pin_project_reconstruct! {
+            [$(#[$attrs])* $vis $struct_ty_ident $ident]
+            [$($def_generics)*] [$($impl_generics)*]
+            [$($ty_generics)*] [$(where $($where_clause)*)?]
+            {
+                $($body_data)*
+            }
+        }
+
+        $crate::__pin_project_make_proj_ty! {
+            [$($proj_mut_ident)?]
+            [$proj_vis $struct_ty_ident $ident]
+            [__pin_project_make_proj_field_mut]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            {
+                $($body_data)*
+            }
+        }
+        $crate::__pin_project_make_proj_ty! {
+            [$($proj_ref_ident)?]
+            [$proj_vis $struct_ty_ident $ident]
+            [__pin_project_make_proj_field_ref]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            {
+                $($body_data)*
+            }
+        }
+        $crate::__pin_project_make_proj_replace_ty! {
+            [$($proj_replace_ident)?]
+            [$proj_vis $struct_ty_ident]
+            [__pin_project_make_proj_field_replace]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            {
+                $($body_data)*
+            }
+        }
+
+        $crate::__pin_project_constant! {
+            [$(#[$attrs])* $vis $struct_ty_ident $ident]
+            [$($proj_mut_ident)?] [$($proj_ref_ident)?] [$($proj_replace_ident)?]
+            [$proj_vis]
+            [$($def_generics)*] [$($impl_generics)*]
+            [$($ty_generics)*] [$(where $($where_clause)*)?]
+            {
+                $($body_data)*
+            }
+            $(impl $($pinned_drop)*)?
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_constant {
+    (
+        [$(#[$attrs:meta])* $vis:vis struct $ident:ident]
+        [$($proj_mut_ident:ident)?] [$($proj_ref_ident:ident)?] [$($proj_replace_ident:ident)?]
+        [$proj_vis:vis]
+        [$($def_generics:tt)*]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident: $field_ty:ty
+            ),+ $(,)?
+        }
+        $(impl $($pinned_drop:tt)*)?
+    ) => {
+        #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+        #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+        // This lint warns of `clippy::*` generated by external macros.
+        // We allow this lint for compatibility with older compilers.
+        #[allow(clippy::unknown_clippy_lints)]
+        #[allow(clippy::redundant_pub_crate)] // This lint warns `pub(crate)` field in private struct.
+        #[allow(clippy::used_underscore_binding)]
+        const _: () = {
+            $crate::__pin_project_make_proj_ty! {
+                [$($proj_mut_ident)? Projection]
+                [$proj_vis struct $ident]
+                [__pin_project_make_proj_field_mut]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                {
+                    $(
+                        $(#[$pin])?
+                        $field_vis $field: $field_ty
+                    ),+
+                }
+            }
+            $crate::__pin_project_make_proj_ty! {
+                [$($proj_ref_ident)? ProjectionRef]
+                [$proj_vis struct $ident]
+                [__pin_project_make_proj_field_ref]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                {
+                    $(
+                        $(#[$pin])?
+                        $field_vis $field: $field_ty
+                    ),+
+                }
+            }
+
+            impl <$($impl_generics)*> $ident <$($ty_generics)*>
+            $(where
+                $($where_clause)*)?
+            {
+                $crate::__pin_project_struct_make_proj_method! {
+                    [$($proj_mut_ident)? Projection]
+                    [$proj_vis]
+                    [project get_unchecked_mut mut]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $(#[$pin])?
+                            $field_vis $field
+                        ),+
+                    }
+                }
+                $crate::__pin_project_struct_make_proj_method! {
+                    [$($proj_ref_ident)? ProjectionRef]
+                    [$proj_vis]
+                    [project_ref get_ref]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $(#[$pin])?
+                            $field_vis $field
+                        ),+
+                    }
+                }
+                $crate::__pin_project_struct_make_proj_replace_method! {
+                    [$($proj_replace_ident)?]
+                    [$proj_vis]
+                    [ProjectionReplace]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $(#[$pin])?
+                            $field_vis $field
+                        ),+
+                    }
+                }
+            }
+
+            $crate::__pin_project_make_unpin_impl! {
+                [$vis $ident]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                $(
+                    $field: $crate::__pin_project_make_unpin_bound!(
+                        $(#[$pin])? $field_ty
+                    )
+                ),+
+            }
+
+            $crate::__pin_project_make_drop_impl! {
+                [$ident]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                $(impl $($pinned_drop)*)?
+            }
+
+            // Ensure that it's impossible to use pin projections on a #[repr(packed)] struct.
+            //
+            // Taking a reference to a packed field is UB, and applying
+            // `#[forbid(unaligned_references)]` makes sure that doing this is a hard error.
+            //
+            // If the struct ends up having #[repr(packed)] applied somehow,
+            // this will generate an (unfriendly) error message. Under all reasonable
+            // circumstances, we'll detect the #[repr(packed)] attribute, and generate
+            // a much nicer error above.
+            //
+            // See https://github.com/taiki-e/pin-project/pull/34 for more details.
+            //
+            // Note:
+            // - Lint-based tricks aren't perfect, but they're much better than nothing:
+            //   https://github.com/taiki-e/pin-project-lite/issues/26
+            //
+            // - Enable both unaligned_references and safe_packed_borrows lints
+            //   because unaligned_references lint does not exist in older compilers:
+            //   https://github.com/taiki-e/pin-project-lite/pull/55
+            //   https://github.com/rust-lang/rust/pull/82525
+            #[forbid(unaligned_references, safe_packed_borrows)]
+            fn __assert_not_repr_packed <$($impl_generics)*> (this: &$ident <$($ty_generics)*>)
+            $(where
+                $($where_clause)*)?
+            {
+                $(
+                    let _ = &this.$field;
+                )+
+            }
+        };
+    };
+    (
+        [$(#[$attrs:meta])* $vis:vis enum $ident:ident]
+        [$($proj_mut_ident:ident)?] [$($proj_ref_ident:ident)?] [$($proj_replace_ident:ident)?]
+        [$proj_vis:vis]
+        [$($def_generics:tt)*]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$variant_attrs:meta])*
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident: $field_ty:ty
+                    ),+ $(,)?
+                })?
+            ),+ $(,)?
+        }
+        $(impl $($pinned_drop:tt)*)?
+    ) => {
+        #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+        // This lint warns of `clippy::*` generated by external macros.
+        // We allow this lint for compatibility with older compilers.
+        #[allow(clippy::unknown_clippy_lints)]
+        #[allow(clippy::used_underscore_binding)]
+        const _: () = {
+            impl <$($impl_generics)*> $ident <$($ty_generics)*>
+            $(where
+                $($where_clause)*)?
+            {
+                $crate::__pin_project_enum_make_proj_method! {
+                    [$($proj_mut_ident)?]
+                    [$proj_vis]
+                    [project get_unchecked_mut mut]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $variant $({
+                                $(
+                                    $(#[$pin])?
+                                    $field
+                                ),+
+                            })?
+                        ),+
+                    }
+                }
+                $crate::__pin_project_enum_make_proj_method! {
+                    [$($proj_ref_ident)?]
+                    [$proj_vis]
+                    [project_ref get_ref]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $variant $({
+                                $(
+                                    $(#[$pin])?
+                                    $field
+                                ),+
+                            })?
+                        ),+
+                    }
+                }
+                $crate::__pin_project_enum_make_proj_replace_method! {
+                    [$($proj_replace_ident)?]
+                    [$proj_vis]
+                    [$($ty_generics)*]
+                    {
+                        $(
+                            $variant $({
+                                $(
+                                    $(#[$pin])?
+                                    $field
+                                ),+
+                            })?
+                        ),+
+                    }
+                }
+            }
+
+            $crate::__pin_project_make_unpin_impl! {
+                [$vis $ident]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                $(
+                    $variant: ($(
+                        $(
+                            $crate::__pin_project_make_unpin_bound!(
+                                $(#[$pin])? $field_ty
+                            )
+                        ),+
+                    )?)
+                ),+
+            }
+
+            $crate::__pin_project_make_drop_impl! {
+                [$ident]
+                [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+                $(impl $($pinned_drop)*)?
+            }
+
+            // We don't need to check for '#[repr(packed)]',
+            // since it does not apply to enums.
+        };
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_reconstruct {
+    (
+        [$(#[$attrs:meta])* $vis:vis struct $ident:ident]
+        [$($def_generics:tt)*] [$($impl_generics:tt)*]
+        [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident: $field_ty:ty
+            ),+ $(,)?
+        }
+    ) => {
+        $(#[$attrs])*
+        $vis struct $ident $($def_generics)*
+        $(where
+            $($where_clause)*)?
+        {
+            $(
+                $field_vis $field: $field_ty
+            ),+
+        }
+    };
+    (
+        [$(#[$attrs:meta])* $vis:vis enum $ident:ident]
+        [$($def_generics:tt)*] [$($impl_generics:tt)*]
+        [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$variant_attrs:meta])*
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident: $field_ty:ty
+                    ),+ $(,)?
+                })?
+            ),+ $(,)?
+        }
+    ) => {
+        $(#[$attrs])*
+        $vis enum $ident $($def_generics)*
+        $(where
+            $($where_clause)*)?
+        {
+            $(
+                $(#[$variant_attrs])*
+                $variant $({
+                    $(
+                        $field: $field_ty
+                    ),+
+                })?
+            ),+
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_ty {
+    ([] $($field:tt)*) => {};
+    (
+        [$proj_ty_ident:ident $default_ident:ident]
+        [$proj_vis:vis struct $ident:ident]
+        $($field:tt)*
+    ) => {};
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis struct $ident:ident]
+        [$__pin_project_make_proj_field:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident: $field_ty:ty
+            ),+ $(,)?
+        }
+    ) => {
+        $crate::__pin_project_make_proj_ty_body! {
+            [$proj_ty_ident]
+            [$proj_vis struct $ident]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            [
+                $(
+                    $field_vis $field: $crate::$__pin_project_make_proj_field!(
+                        $(#[$pin])? $field_ty
+                    )
+                ),+
+            ]
+        }
+    };
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis enum $ident:ident]
+        [$__pin_project_make_proj_field:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$variant_attrs:meta])*
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident: $field_ty:ty
+                    ),+ $(,)?
+                })?
+            ),+ $(,)?
+        }
+    ) => {
+        $crate::__pin_project_make_proj_ty_body! {
+            [$proj_ty_ident]
+            [$proj_vis enum $ident]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            [
+                $(
+                    $variant $({
+                        $(
+                            $field: $crate::$__pin_project_make_proj_field!(
+                                $(#[$pin])? $field_ty
+                            )
+                        ),+
+                    })?
+                ),+
+            ]
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_ty_body {
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis $struct_ty_ident:ident $ident:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        [$($body_data:tt)+]
+    ) => {
+        #[allow(dead_code)] // This lint warns unused fields/variants.
+        #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+        // This lint warns of `clippy::*` generated by external macros.
+        // We allow this lint for compatibility with older compilers.
+        #[allow(clippy::unknown_clippy_lints)]
+        #[allow(clippy::mut_mut)] // This lint warns `&mut &mut <ty>`. (only needed for project)
+        #[allow(clippy::redundant_pub_crate)] // This lint warns `pub(crate)` field in private struct.
+        #[allow(clippy::ref_option_ref)] // This lint warns `&Option<&<ty>>`. (only needed for project_ref)
+        #[allow(clippy::type_repetition_in_bounds)] // https://github.com/rust-lang/rust-clippy/issues/4326
+        $proj_vis $struct_ty_ident $proj_ty_ident <'__pin, $($impl_generics)*>
+        where
+            $ident <$($ty_generics)*>: '__pin
+            $(, $($where_clause)*)?
+        {
+            $($body_data)+
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_replace_ty {
+    ([] $($field:tt)*) => {};
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis struct]
+        [$__pin_project_make_proj_field:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident: $field_ty:ty
+            ),+ $(,)?
+        }
+    ) => {
+        $crate::__pin_project_make_proj_replace_ty_body! {
+            [$proj_ty_ident]
+            [$proj_vis struct]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            [
+                $(
+                    $field_vis $field: $crate::$__pin_project_make_proj_field!(
+                        $(#[$pin])? $field_ty
+                    )
+                ),+
+            ]
+        }
+    };
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis enum]
+        [$__pin_project_make_proj_field:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        {
+            $(
+                $(#[$variant_attrs:meta])*
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident: $field_ty:ty
+                    ),+ $(,)?
+                })?
+            ),+ $(,)?
+        }
+    ) => {
+        $crate::__pin_project_make_proj_replace_ty_body! {
+            [$proj_ty_ident]
+            [$proj_vis enum]
+            [$($impl_generics)*] [$($ty_generics)*] [$(where $($where_clause)*)?]
+            [
+                $(
+                    $variant $({
+                        $(
+                            $field: $crate::$__pin_project_make_proj_field!(
+                                $(#[$pin])? $field_ty
+                            )
+                        ),+
+                    })?
+                ),+
+            ]
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_replace_ty_body {
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis $struct_ty_ident:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        [$($body_data:tt)+]
+    ) => {
+        #[allow(dead_code)] // This lint warns unused fields/variants.
+        #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+        #[allow(clippy::mut_mut)] // This lint warns `&mut &mut <ty>`. (only needed for project)
+        #[allow(clippy::redundant_pub_crate)] // This lint warns `pub(crate)` field in private struct.
+        #[allow(clippy::type_repetition_in_bounds)] // https://github.com/rust-lang/rust-clippy/issues/4326
+        $proj_vis $struct_ty_ident $proj_ty_ident <$($impl_generics)*>
+        where
+            $($($where_clause)*)?
+        {
+            $($body_data)+
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_replace_block {
+    (
+        [$($proj_path:tt)+]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident
+            ),+
+        }
+    ) => {
+        let result = $($proj_path)* {
+            $(
+                $field: $crate::__pin_project_make_replace_field_proj!(
+                    $(#[$pin])? $field
+                )
+            ),+
+        };
+
+        {
+            ( $(
+                $crate::__pin_project_make_unsafe_drop_in_place_guard!(
+                    $(#[$pin])? $field
+                ),
+            )* );
+        }
+
+        result
+    };
+    ([$($proj_path:tt)+]) => { $($proj_path)* };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_struct_make_proj_method {
+    ([] $($variant:tt)*) => {};
+    (
+        [$proj_ty_ident:ident $_ignored_default_arg:ident]
+        [$proj_vis:vis]
+        [$method_ident:ident $get_method:ident $($mut:ident)?]
+        [$($ty_generics:tt)*]
+        $($variant:tt)*
+    ) => {
+        $crate::__pin_project_struct_make_proj_method! {
+            [$proj_ty_ident]
+            [$proj_vis]
+            [$method_ident $get_method $($mut)?]
+            [$($ty_generics)*]
+            $($variant)*
+        }
+    };
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis]
+        [$method_ident:ident $get_method:ident $($mut:ident)?]
+        [$($ty_generics:tt)*]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident
+            ),+
+        }
+    ) => {
+        $proj_vis fn $method_ident<'__pin>(
+            self: $crate::__private::Pin<&'__pin $($mut)? Self>,
+        ) -> $proj_ty_ident <'__pin, $($ty_generics)*> {
+            unsafe {
+                let Self { $($field),* } = self.$get_method();
+                $proj_ty_ident {
+                    $(
+                        $field: $crate::__pin_project_make_unsafe_field_proj!(
+                            $(#[$pin])? $field
+                        )
+                    ),+
+                }
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_struct_make_proj_replace_method {
+    ([] $($field:tt)*) => {};
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis]
+        [$_proj_ty_ident:ident]
+        [$($ty_generics:tt)*]
+        {
+            $(
+                $(#[$pin:ident])?
+                $field_vis:vis $field:ident
+            ),+
+        }
+    ) => {
+        $proj_vis fn project_replace(
+            self: $crate::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> $proj_ty_ident <$($ty_generics)*> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+
+                // Destructors will run in reverse order, so next create a guard to overwrite
+                // `self` with the replacement value without calling destructors.
+                let __guard = $crate::__private::UnsafeOverwriteGuard::new(__self_ptr, replacement);
+
+                let Self { $($field),* } = &mut *__self_ptr;
+
+                $crate::__pin_project_make_proj_replace_block! {
+                    [$proj_ty_ident]
+                    {
+                        $(
+                            $(#[$pin])?
+                            $field
+                        ),+
+                    }
+                }
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_enum_make_proj_method {
+    ([] $($variant:tt)*) => {};
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis]
+        [$method_ident:ident $get_method:ident $($mut:ident)?]
+        [$($ty_generics:tt)*]
+        {
+            $(
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident
+                    ),+
+                })?
+            ),+
+        }
+    ) => {
+        $proj_vis fn $method_ident<'__pin>(
+            self: $crate::__private::Pin<&'__pin $($mut)? Self>,
+        ) -> $proj_ty_ident <'__pin, $($ty_generics)*> {
+            unsafe {
+                match self.$get_method() {
+                    $(
+                        Self::$variant $({
+                            $($field),+
+                        })? => {
+                            $proj_ty_ident::$variant $({
+                                $(
+                                    $field: $crate::__pin_project_make_unsafe_field_proj!(
+                                        $(#[$pin])? $field
+                                    )
+                                ),+
+                            })?
+                        }
+                    ),+
+                }
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_enum_make_proj_replace_method {
+    ([] $($field:tt)*) => {};
+    (
+        [$proj_ty_ident:ident]
+        [$proj_vis:vis]
+        [$($ty_generics:tt)*]
+        {
+            $(
+                $variant:ident $({
+                    $(
+                        $(#[$pin:ident])?
+                        $field:ident
+                    ),+
+                })?
+            ),+
+        }
+    ) => {
+        $proj_vis fn project_replace(
+            self: $crate::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> $proj_ty_ident <$($ty_generics)*> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+
+                // Destructors will run in reverse order, so next create a guard to overwrite
+                // `self` with the replacement value without calling destructors.
+                let __guard = $crate::__private::UnsafeOverwriteGuard::new(__self_ptr, replacement);
+
+                match &mut *__self_ptr {
+                    $(
+                        Self::$variant $({
+                            $($field),+
+                        })? => {
+                            $crate::__pin_project_make_proj_replace_block! {
+                                [$proj_ty_ident :: $variant]
+                                $({
+                                    $(
+                                        $(#[$pin])?
+                                        $field
+                                    ),+
+                                })?
+                            }
+                        }
+                    ),+
+                }
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_unpin_impl {
+    (
+        [$vis:vis $ident:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+        $($field:tt)*
+    ) => {
+        // Automatically create the appropriate conditional `Unpin` implementation.
+        //
+        // Basically this is equivalent to the following code:
+        // ```rust
+        // impl<T, U> Unpin for Struct<T, U> where T: Unpin {}
+        // ```
+        //
+        // However, if struct is public and there is a private type field,
+        // this would cause an E0446 (private type in public interface).
+        //
+        // When RFC 2145 is implemented (rust-lang/rust#48054),
+        // this will become a lint, rather then a hard error.
+        //
+        // As a workaround for this, we generate a new struct, containing all of the pinned
+        // fields from our #[pin_project] type. This struct is declared within
+        // a function, which makes it impossible to be named by user code.
+        // This guarantees that it will use the default auto-trait impl for Unpin -
+        // that is, it will implement Unpin iff all of its fields implement Unpin.
+        // This type can be safely declared as 'public', satisfying the privacy
+        // checker without actually allowing user code to access it.
+        //
+        // This allows users to apply the #[pin_project] attribute to types
+        // regardless of the privacy of the types of their fields.
+        //
+        // See also https://github.com/taiki-e/pin-project/pull/53.
+        #[allow(non_snake_case)]
+        $vis struct __Origin <'__pin, $($impl_generics)*>
+        $(where
+            $($where_clause)*)?
+        {
+            __dummy_lifetime: $crate::__private::PhantomData<&'__pin ()>,
+            $($field)*
+        }
+        impl <'__pin, $($impl_generics)*> $crate::__private::Unpin for $ident <$($ty_generics)*>
+        where
+            __Origin <'__pin, $($ty_generics)*>: $crate::__private::Unpin
+            $(, $($where_clause)*)?
+        {
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_drop_impl {
+    (
+        [$_ident:ident]
+        [$($_impl_generics:tt)*] [$($_ty_generics:tt)*] [$(where $($_where_clause:tt)*)?]
+        impl $(<
+            $( $lifetime:lifetime $(: $lifetime_bound:lifetime)? ),* $(,)?
+            $( $generics:ident
+                $(: $generics_bound:path)?
+                $(: ?$generics_unsized_bound:path)?
+                $(: $generics_lifetime_bound:lifetime)?
+            ),*
+        >)? PinnedDrop for $self_ty:ty
+        $(where
+            $( $where_clause_ty:ty
+                $(: $where_clause_bound:path)?
+                $(: ?$where_clause_unsized_bound:path)?
+                $(: $where_clause_lifetime_bound:lifetime)?
+            ),* $(,)?
+        )?
+        {
+            fn drop($($arg:ident)+: Pin<&mut Self>) {
+                $($tt:tt)*
+            }
+        }
+    ) => {
+        impl $(<
+            $( $lifetime $(: $lifetime_bound)? ,)*
+            $( $generics
+                $(: $generics_bound)?
+                $(: ?$generics_unsized_bound)?
+                $(: $generics_lifetime_bound)?
+            ),*
+        >)? $crate::__private::Drop for $self_ty
+        $(where
+            $( $where_clause_ty
+                $(: $where_clause_bound)?
+                $(: ?$where_clause_unsized_bound)?
+                $(: $where_clause_lifetime_bound)?
+            ),*
+        )?
+        {
+            fn drop(&mut self) {
+                // Implementing `__DropInner::__drop_inner` is safe, but calling it is not safe.
+                // This is because destructors can be called multiple times in safe code and
+                // [double dropping is unsound](https://github.com/rust-lang/rust/pull/62360).
+                //
+                // `__drop_inner` is defined as a safe method, but this is fine since
+                // `__drop_inner` is not accessible by the users and we call `__drop_inner` only
+                // once.
+                //
+                // Users can implement [`Drop`] safely using `pin_project!` and can drop a
+                // type that implements `PinnedDrop` using the [`drop`] function safely.
+                fn __drop_inner $(<
+                    $( $lifetime $(: $lifetime_bound)? ,)*
+                    $( $generics
+                        $(: $generics_bound)?
+                        $(: ?$generics_unsized_bound)?
+                        $(: $generics_lifetime_bound)?
+                    ),*
+                >)? (
+                    $($arg)+: $crate::__private::Pin<&mut $self_ty>,
+                )
+                $(where
+                    $( $where_clause_ty
+                        $(: $where_clause_bound)?
+                        $(: ?$where_clause_unsized_bound)?
+                        $(: $where_clause_lifetime_bound)?
+                    ),*
+                )?
+                {
+                    // A dummy `__drop_inner` function to prevent users call outer `__drop_inner`.
+                    fn __drop_inner() {}
+                    $($tt)*
+                }
+
+                // Safety - we're in 'drop', so we know that 'self' will
+                // never move again.
+                let pinned_self: $crate::__private::Pin<&mut Self>
+                    = unsafe { $crate::__private::Pin::new_unchecked(self) };
+                // We call `__drop_inner` only once. Since `__DropInner::__drop_inner`
+                // is not accessible by the users, it is never called again.
+                __drop_inner(pinned_self);
+            }
+        }
+    };
+    (
+        [$ident:ident]
+        [$($impl_generics:tt)*] [$($ty_generics:tt)*] [$(where $($where_clause:tt)*)?]
+    ) => {
+        // Ensure that struct does not implement `Drop`.
+        //
+        // There are two possible cases:
+        // 1. The user type does not implement Drop. In this case,
+        // the first blanked impl will not apply to it. This code
+        // will compile, as there is only one impl of MustNotImplDrop for the user type
+        // 2. The user type does impl Drop. This will make the blanket impl applicable,
+        // which will then conflict with the explicit MustNotImplDrop impl below.
+        // This will result in a compilation error, which is exactly what we want.
+        trait MustNotImplDrop {}
+        #[allow(clippy::drop_bounds, drop_bounds)]
+        impl<T: $crate::__private::Drop> MustNotImplDrop for T {}
+        impl <$($impl_generics)*> MustNotImplDrop for $ident <$($ty_generics)*>
+        $(where
+            $($where_clause)*)?
+        {
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_unpin_bound {
+    (#[pin] $field_ty:ty) => {
+        $field_ty
+    };
+    ($field_ty:ty) => {
+        $crate::__private::AlwaysUnpin<$field_ty>
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_unsafe_field_proj {
+    (#[pin] $field:ident) => {
+        $crate::__private::Pin::new_unchecked($field)
+    };
+    ($field:ident) => {
+        $field
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_replace_field_proj {
+    (#[pin] $field:ident) => {
+        $crate::__private::PhantomData
+    };
+    ($field:ident) => {
+        $crate::__private::ptr::read($field)
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_unsafe_drop_in_place_guard {
+    (#[pin] $field:ident) => {
+        $crate::__private::UnsafeDropInPlaceGuard::new($field)
+    };
+    ($field:ident) => {
+        ()
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_field_mut {
+    (#[pin] $field_ty:ty) => {
+        $crate::__private::Pin<&'__pin mut ($field_ty)>
+    };
+    ($field_ty:ty) => {
+        &'__pin mut ($field_ty)
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_field_ref {
+    (#[pin] $field_ty:ty) => {
+        $crate::__private::Pin<&'__pin ($field_ty)>
+    };
+    ($field_ty:ty) => {
+        &'__pin ($field_ty)
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_make_proj_field_replace {
+    (#[pin] $field_ty:ty) => {
+        $crate::__private::PhantomData<$field_ty>
+    };
+    ($field_ty:ty) => {
+        $field_ty
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_internal {
+    // parsing proj_mut_ident
+    (
+        []
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+
+        #[project = $proj_mut_ident:ident]
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_internal! {
+            [$proj_mut_ident]
+            [$($proj_ref_ident)?]
+            [$($proj_replace_ident)?]
+            [$($attrs)*]
+            $($tt)*
+        }
+    };
+    // parsing proj_ref_ident
+    (
+        [$($proj_mut_ident:ident)?]
+        []
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+
+        #[project_ref = $proj_ref_ident:ident]
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_internal! {
+            [$($proj_mut_ident)?]
+            [$proj_ref_ident]
+            [$($proj_replace_ident)?]
+            [$($attrs)*]
+            $($tt)*
+        }
+    };
+    // parsing proj_replace_ident
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        []
+        [$($attrs:tt)*]
+
+        #[project_replace = $proj_replace_ident:ident]
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_internal! {
+            [$($proj_mut_ident)?]
+            [$($proj_ref_ident)?]
+            [$proj_replace_ident]
+            [$($attrs)*]
+            $($tt)*
+        }
+    };
+    // this is actually part of a recursive step that picks off a single non-`pin_project_lite` attribute
+    // there could be more to parse
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+
+        #[$($attr:tt)*]
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_internal! {
+            [$($proj_mut_ident)?]
+            [$($proj_ref_ident)?]
+            [$($proj_replace_ident)?]
+            [$($attrs)* #[$($attr)*]]
+            $($tt)*
+        }
+    };
+    // now determine visibility
+    // if public, downgrade
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+        pub $struct_ty_ident:ident $ident:ident
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_parse_generics! {
+            [$($proj_mut_ident)?]
+            [$($proj_ref_ident)?]
+            [$($proj_replace_ident)?]
+            [$($attrs)*]
+            [pub $struct_ty_ident $ident pub(crate)]
+            $($tt)*
+        }
+    };
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+        $vis:vis $struct_ty_ident:ident $ident:ident
+        $($tt:tt)*
+    ) => {
+        $crate::__pin_project_parse_generics! {
+            [$($proj_mut_ident)?]
+            [$($proj_ref_ident)?]
+            [$($proj_replace_ident)?]
+            [$($attrs)*]
+            [$vis $struct_ty_ident $ident $vis]
+            $($tt)*
+        }
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __pin_project_parse_generics {
+    (
+        [$($proj_mut_ident:ident)?]
+        [$($proj_ref_ident:ident)?]
+        [$($proj_replace_ident:ident)?]
+        [$($attrs:tt)*]
+        [$vis:vis $struct_ty_ident:ident $ident:ident $proj_ty_vis:vis]
+        $(<
+            $( $lifetime:lifetime $(: $lifetime_bound:lifetime)? ),* $(,)?
+            $( $generics:ident
+                $(: $generics_bound:path)?
+                $(: ?$generics_unsized_bound:path)?
+                $(: $generics_lifetime_bound:lifetime)?
+                $(= $generics_default:ty)?
+            ),* $(,)?
+        >)?
+        $(where
+            $( $where_clause_ty:ty
+                $(: $where_clause_bound:path)?
+                $(: ?$where_clause_unsized_bound:path)?
+                $(: $where_clause_lifetime_bound:lifetime)?
+            ),* $(,)?
+        )?
+        {
+            $($body_data:tt)*
+        }
+        $(impl $($pinned_drop:tt)*)?
+    ) => {
+        $crate::__pin_project_expand! {
+            [$($proj_mut_ident)?]
+            [$($proj_ref_ident)?]
+            [$($proj_replace_ident)?]
+            [$proj_ty_vis]
+            [$($attrs)* $vis $struct_ty_ident $ident]
+            [$(<
+                $( $lifetime $(: $lifetime_bound)? ,)*
+                $( $generics
+                    $(: $generics_bound)?
+                    $(: ?$generics_unsized_bound)?
+                    $(: $generics_lifetime_bound)?
+                    $(= $generics_default)?
+                ),*
+            >)?]
+            [$(
+                $( $lifetime $(: $lifetime_bound)? ,)*
+                $( $generics
+                    $(: $generics_bound)?
+                    $(: ?$generics_unsized_bound)?
+                    $(: $generics_lifetime_bound)?
+                ),*
+            )?]
+            [$( $( $lifetime ,)* $( $generics ),* )?]
+            [$(where $( $where_clause_ty
+                $(: $where_clause_bound)?
+                $(: ?$where_clause_unsized_bound)?
+                $(: $where_clause_lifetime_bound)?
+            ),* )?]
+            {
+                $($body_data)*
+            }
+            $(impl $($pinned_drop)*)?
+        }
+    };
+}
+
+#[doc(hidden)]
+pub mod __private {
+    use core::mem::ManuallyDrop;
+    #[doc(hidden)]
+    pub use core::{
+        marker::{PhantomData, Unpin},
+        ops::Drop,
+        pin::Pin,
+        ptr,
+    };
+
+    // This is an internal helper struct used by `pin_project!`.
+    #[doc(hidden)]
+    pub struct AlwaysUnpin<T: ?Sized>(PhantomData<T>);
+
+    impl<T: ?Sized> Unpin for AlwaysUnpin<T> {}
+
+    // This is an internal helper used to ensure a value is dropped.
+    #[doc(hidden)]
+    pub struct UnsafeDropInPlaceGuard<T: ?Sized>(*mut T);
+
+    impl<T: ?Sized> UnsafeDropInPlaceGuard<T> {
+        #[doc(hidden)]
+        pub unsafe fn new(ptr: *mut T) -> Self {
+            Self(ptr)
+        }
+    }
+
+    impl<T: ?Sized> Drop for UnsafeDropInPlaceGuard<T> {
+        fn drop(&mut self) {
+            unsafe {
+                ptr::drop_in_place(self.0);
+            }
+        }
+    }
+
+    // This is an internal helper used to ensure a value is overwritten without
+    // its destructor being called.
+    #[doc(hidden)]
+    pub struct UnsafeOverwriteGuard<T> {
+        target: *mut T,
+        value: ManuallyDrop<T>,
+    }
+
+    impl<T> UnsafeOverwriteGuard<T> {
+        #[doc(hidden)]
+        pub unsafe fn new(target: *mut T, value: T) -> Self {
+            Self { target, value: ManuallyDrop::new(value) }
+        }
+    }
+
+    impl<T> Drop for UnsafeOverwriteGuard<T> {
+        fn drop(&mut self) {
+            unsafe {
+                ptr::write(self.target, ptr::read(&*self.value));
+            }
+        }
+    }
+}
diff --git a/third_party/rust/pin-project-lite/tests/README.md b/third_party/rust/pin-project-lite/tests/README.md
new file mode 100644
index 0000000000..47216165df
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/README.md
@@ -0,0 +1,46 @@
+# Tests
+
+Many of the tests in this repository are based on [pin-project's tests](https://github.com/taiki-e/pin-project/tree/HEAD/tests).
+
+To run all tests, run the following command:
+
+```sh
+cargo +nightly test --all
+```
+
+## UI tests (`ui`, `compiletest.rs`)
+
+This checks errors detected by the macro or the Rust compiler in the resulting
+expanded code.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test compiletest
+```
+
+Locally, this test updates the files in the `ui` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`ui` directory after running the test, please commit them.
+
+See also [`trybuild` documentation](https://docs.rs/trybuild).
+
+## Expansion tests (`expand`, `expandtest.rs`)
+
+Similar to ui tests, but instead of checking the compiler output, this checks
+the code generated by macros.
+
+See pin-project's [examples](https://github.com/taiki-e/pin-project/tree/HEAD/examples)
+for descriptions of what the generated code does, and why it needs to be generated.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test expandtest
+```
+
+Locally, this test updates the files in the `expand` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`expand` directory after running the test, please commit them.
+
+See also [`macrotest` documentation](https://docs.rs/macrotest).
diff --git a/third_party/rust/pin-project-lite/tests/auxiliary/mod.rs b/third_party/rust/pin-project-lite/tests/auxiliary/mod.rs
new file mode 100644
index 0000000000..1457099160
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/auxiliary/mod.rs
@@ -0,0 +1,12 @@
+#![allow(dead_code, unused_macros)]
+
+macro_rules! assert_unpin {
+    ($ty:ty) => {
+        static_assertions::assert_impl_all!($ty: Unpin);
+    };
+}
+macro_rules! assert_not_unpin {
+    ($ty:ty) => {
+        static_assertions::assert_not_impl_all!($ty: Unpin);
+    };
+}
diff --git a/third_party/rust/pin-project-lite/tests/compiletest.rs b/third_party/rust/pin-project-lite/tests/compiletest.rs
new file mode 100644
index 0000000000..70d2358943
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/compiletest.rs
@@ -0,0 +1,15 @@
+#![cfg(not(miri))]
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn ui() {
+    if env::var_os("CI").is_none() {
+        env::set_var("TRYBUILD", "overwrite");
+    }
+
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/**/*.rs");
+}
diff --git a/third_party/rust/pin-project-lite/tests/drop_order.rs b/third_party/rust/pin-project-lite/tests/drop_order.rs
new file mode 100644
index 0000000000..6e5deaf154
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/drop_order.rs
@@ -0,0 +1,169 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+// Refs: https://doc.rust-lang.org/reference/destructors.html
+
+use std::{cell::Cell, panic, pin::Pin, thread};
+
+use pin_project_lite::pin_project;
+
+struct D<'a>(&'a Cell<usize>, usize);
+
+impl Drop for D<'_> {
+    fn drop(&mut self) {
+        if !thread::panicking() {
+            let old = self.0.replace(self.1);
+            assert_eq!(old, self.1 - 1);
+        }
+    }
+}
+
+pin_project! {
+#[project = StructPinnedProj]
+#[project_ref = StructPinnedProjRef]
+#[project_replace = StructPinnedProjReplace]
+struct StructPinned<'a> {
+    #[pin]
+    f1: D<'a>,
+    #[pin]
+    f2: D<'a>,
+}
+}
+
+pin_project! {
+#[project = StructUnpinnedProj]
+#[project_ref = StructUnpinnedProjRef]
+#[project_replace = StructUnpinnedProjReplace]
+struct StructUnpinned<'a> {
+    f1: D<'a>,
+    f2: D<'a>,
+}
+}
+
+pin_project! {
+#[project_replace = EnumProjReplace]
+enum Enum<'a> {
+    #[allow(dead_code)] // false positive that fixed in Rust 1.38
+    StructPinned {
+        #[pin]
+        f1: D<'a>,
+        #[pin]
+        f2: D<'a>,
+    },
+    #[allow(dead_code)] // false positive that fixed in Rust 1.38
+    StructUnpinned {
+        f1: D<'a>,
+        f2: D<'a>,
+    },
+}
+}
+
+#[test]
+fn struct_pinned() {
+    {
+        let c = Cell::new(0);
+        let _x = StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(StructPinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+#[test]
+fn struct_unpinned() {
+    {
+        let c = Cell::new(0);
+        let _x = StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(StructUnpinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+#[test]
+fn enum_struct() {
+    {
+        let c = Cell::new(0);
+        let _x = Enum::StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::StructPinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+
+    {
+        let c = Cell::new(0);
+        let _x = Enum::StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::StructUnpinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+// https://github.com/rust-lang/rust/issues/47949
+// https://github.com/taiki-e/pin-project/pull/194#discussion_r419098111
+#[allow(clippy::many_single_char_names)]
+#[test]
+fn project_replace_panic() {
+    pin_project! {
+    #[project_replace = SProjReplace]
+    struct S<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+    }
+
+    struct D<'a>(&'a mut bool, bool);
+    impl Drop for D<'_> {
+        fn drop(&mut self) {
+            *self.0 = true;
+            if self.1 {
+                panic!();
+            }
+        }
+    }
+
+    let (mut a, mut b, mut c, mut d) = (false, false, false, false);
+    let res = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let mut x = S { pinned: D(&mut a, true), unpinned: D(&mut b, false) };
+        let _y = Pin::new(&mut x)
+            .project_replace(S { pinned: D(&mut c, false), unpinned: D(&mut d, false) });
+        // Previous `x.pinned` was dropped and panicked when `project_replace` is
+        // called, so this is unreachable.
+        unreachable!();
+    }));
+    assert!(res.is_err());
+    assert!(a);
+    assert!(b);
+    assert!(c);
+    assert!(d);
+
+    let (mut a, mut b, mut c, mut d) = (false, false, false, false);
+    let res = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let mut x = S { pinned: D(&mut a, false), unpinned: D(&mut b, true) };
+        {
+            let _y = Pin::new(&mut x)
+                .project_replace(S { pinned: D(&mut c, false), unpinned: D(&mut d, false) });
+            // `_y` (previous `x.unpinned`) live to the end of this scope, so
+            // this is not unreachable.
+            // unreachable!();
+        }
+        unreachable!();
+    }));
+    assert!(res.is_err());
+    assert!(a);
+    assert!(b);
+    assert!(c);
+    assert!(d);
+}
diff --git a/third_party/rust/pin-project-lite/tests/expand/default/enum.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/default/enum.expanded.rs
new file mode 100644
index 0000000000..eae0aac85e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/default/enum.expanded.rs
@@ -0,0 +1,127 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProj<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjRef<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjReplace<T, U> {
+    Struct {
+        pinned: ::pin_project_lite::__private::PhantomData<T>,
+        unpinned: U,
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> EnumProj<'__pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => EnumProj::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> EnumProjRef<'__pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => EnumProjRef::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+        fn project_replace(
+            self: ::pin_project_lite::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> EnumProjReplace<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = ::pin_project_lite::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned, unpinned } => {
+                        let result = EnumProjReplace::Struct {
+                            pinned: ::pin_project_lite::__private::PhantomData,
+                            unpinned: ::pin_project_lite::__private::ptr::read(unpinned),
+                        };
+                        {
+                            (
+                                ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned),
+                                (),
+                            );
+                        }
+                        result
+                    }
+                    Self::Unit => EnumProjReplace::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/default/enum.rs b/third_party/rust/pin-project-lite/tests/expand/default/enum.rs
new file mode 100644
index 0000000000..90d6860a81
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/default/enum.rs
@@ -0,0 +1,17 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = EnumProj]
+    #[project_ref = EnumProjRef]
+    #[project_replace = EnumProjReplace]
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/default/struct.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/default/struct.expanded.rs
new file mode 100644
index 0000000000..8ab318cfb8
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/default/struct.expanded.rs
@@ -0,0 +1,84 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Projection {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjectionRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/default/struct.rs b/third_party/rust/pin-project-lite/tests/expand/default/struct.rs
new file mode 100644
index 0000000000..e5447c70a6
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/default/struct.rs
@@ -0,0 +1,11 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/multifields/enum.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/multifields/enum.expanded.rs
new file mode 100644
index 0000000000..fca0febcda
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/multifields/enum.expanded.rs
@@ -0,0 +1,88 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct {
+        pinned1: T,
+        pinned2: T,
+        unpinned1: U,
+        unpinned2: U,
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjReplace<T, U> {
+    Struct {
+        pinned1: ::pin_project_lite::__private::PhantomData<T>,
+        pinned2: ::pin_project_lite::__private::PhantomData<T>,
+        unpinned1: U,
+        unpinned2: U,
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project_replace(
+            self: ::pin_project_lite::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> EnumProjReplace<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = ::pin_project_lite::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct {
+                        pinned1,
+                        pinned2,
+                        unpinned1,
+                        unpinned2,
+                    } => {
+                        let result = EnumProjReplace::Struct {
+                            pinned1: ::pin_project_lite::__private::PhantomData,
+                            pinned2: ::pin_project_lite::__private::PhantomData,
+                            unpinned1: ::pin_project_lite::__private::ptr::read(unpinned1),
+                            unpinned2: ::pin_project_lite::__private::ptr::read(unpinned2),
+                        };
+                        {
+                            (
+                                ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned1),
+                                ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned2),
+                                (),
+                                (),
+                            );
+                        }
+                        result
+                    }
+                    Self::Unit => EnumProjReplace::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (
+            T,
+            T,
+            ::pin_project_lite::__private::AlwaysUnpin<U>,
+            ::pin_project_lite::__private::AlwaysUnpin<U>,
+        ),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/multifields/enum.rs b/third_party/rust/pin-project-lite/tests/expand/multifields/enum.rs
new file mode 100644
index 0000000000..c713362ad6
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/multifields/enum.rs
@@ -0,0 +1,18 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+#[project_replace = EnumProjReplace]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned1: T,
+        #[pin]
+        pinned2: T,
+        unpinned1: U,
+        unpinned2: U,
+    },
+    Unit,
+}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/multifields/struct.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/multifields/struct.expanded.rs
new file mode 100644
index 0000000000..4320f68438
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/multifields/struct.expanded.rs
@@ -0,0 +1,152 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned1: T,
+    pinned2: T,
+    unpinned1: U,
+    unpinned2: U,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProjReplace<T, U> {
+    pinned1: ::pin_project_lite::__private::PhantomData<T>,
+    pinned2: ::pin_project_lite::__private::PhantomData<T>,
+    unpinned1: U,
+    unpinned2: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned1: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        pinned2: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned1: &'__pin mut (U),
+        unpinned2: &'__pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned1: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        pinned2: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned1: &'__pin (U),
+        unpinned2: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self {
+                    pinned1,
+                    pinned2,
+                    unpinned1,
+                    unpinned2,
+                } = self.get_unchecked_mut();
+                Projection {
+                    pinned1: ::pin_project_lite::__private::Pin::new_unchecked(pinned1),
+                    pinned2: ::pin_project_lite::__private::Pin::new_unchecked(pinned2),
+                    unpinned1: unpinned1,
+                    unpinned2: unpinned2,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self {
+                    pinned1,
+                    pinned2,
+                    unpinned1,
+                    unpinned2,
+                } = self.get_ref();
+                ProjectionRef {
+                    pinned1: ::pin_project_lite::__private::Pin::new_unchecked(pinned1),
+                    pinned2: ::pin_project_lite::__private::Pin::new_unchecked(pinned2),
+                    unpinned1: unpinned1,
+                    unpinned2: unpinned2,
+                }
+            }
+        }
+        fn project_replace(
+            self: ::pin_project_lite::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> StructProjReplace<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = ::pin_project_lite::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    replacement,
+                );
+                let Self {
+                    pinned1,
+                    pinned2,
+                    unpinned1,
+                    unpinned2,
+                } = &mut *__self_ptr;
+                let result = StructProjReplace {
+                    pinned1: ::pin_project_lite::__private::PhantomData,
+                    pinned2: ::pin_project_lite::__private::PhantomData,
+                    unpinned1: ::pin_project_lite::__private::ptr::read(unpinned1),
+                    unpinned2: ::pin_project_lite::__private::ptr::read(unpinned2),
+                };
+                {
+                    (
+                        ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned1),
+                        ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned2),
+                        (),
+                        (),
+                    );
+                }
+                result
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned1: T,
+        pinned2: T,
+        unpinned1: ::pin_project_lite::__private::AlwaysUnpin<U>,
+        unpinned2: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned1;
+        let _ = &this.pinned2;
+        let _ = &this.unpinned1;
+        let _ = &this.unpinned2;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/multifields/struct.rs b/third_party/rust/pin-project-lite/tests/expand/multifields/struct.rs
new file mode 100644
index 0000000000..a1d45d168e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/multifields/struct.rs
@@ -0,0 +1,15 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+#[project_replace = StructProjReplace]
+struct Struct<T, U> {
+    #[pin]
+    pinned1: T,
+    #[pin]
+    pinned2: T,
+    unpinned1: U,
+    unpinned2: U,
+}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.expanded.rs
new file mode 100644
index 0000000000..eae0aac85e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.expanded.rs
@@ -0,0 +1,127 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProj<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjRef<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjReplace<T, U> {
+    Struct {
+        pinned: ::pin_project_lite::__private::PhantomData<T>,
+        unpinned: U,
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> EnumProj<'__pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => EnumProj::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> EnumProjRef<'__pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => EnumProjRef::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+        fn project_replace(
+            self: ::pin_project_lite::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> EnumProjReplace<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = ::pin_project_lite::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned, unpinned } => {
+                        let result = EnumProjReplace::Struct {
+                            pinned: ::pin_project_lite::__private::PhantomData,
+                            unpinned: ::pin_project_lite::__private::ptr::read(unpinned),
+                        };
+                        {
+                            (
+                                ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned),
+                                (),
+                            );
+                        }
+                        result
+                    }
+                    Self::Unit => EnumProjReplace::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.rs
new file mode 100644
index 0000000000..90d6860a81
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-all.rs
@@ -0,0 +1,17 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = EnumProj]
+    #[project_ref = EnumProjRef]
+    #[project_replace = EnumProjReplace]
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.expanded.rs
new file mode 100644
index 0000000000..7c4d6afbf9
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.expanded.rs
@@ -0,0 +1,57 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProj<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> EnumProj<'__pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => EnumProj::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.rs
new file mode 100644
index 0000000000..69beecd1d9
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-mut.rs
@@ -0,0 +1,15 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = EnumProj]
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.expanded.rs
new file mode 100644
index 0000000000..28ce97da7b
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.expanded.rs
@@ -0,0 +1,26 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {}
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.rs
new file mode 100644
index 0000000000..b2e3f9d76a
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-none.rs
@@ -0,0 +1,14 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.expanded.rs
new file mode 100644
index 0000000000..a1a013bda4
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.expanded.rs
@@ -0,0 +1,57 @@
+use pin_project_lite::pin_project;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjRef<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> EnumProjRef<'__pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => EnumProjRef::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.rs b/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.rs
new file mode 100644
index 0000000000..480d592d68
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/enum-ref.rs
@@ -0,0 +1,15 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project_ref = EnumProjRef]
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.expanded.rs
new file mode 100644
index 0000000000..b91c24eb2a
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.expanded.rs
@@ -0,0 +1,117 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProj<'__pin, T, U>
+where
+    Struct<T, U>: '__pin,
+{
+    pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+    unpinned: &'__pin mut (U),
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProjRef<'__pin, T, U>
+where
+    Struct<T, U>: '__pin,
+{
+    pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+    unpinned: &'__pin (U),
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProjReplace<T, U> {
+    pinned: ::pin_project_lite::__private::PhantomData<T>,
+    unpinned: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> StructProj<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                StructProj {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> StructProjRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                StructProjRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_replace(
+            self: ::pin_project_lite::__private::Pin<&mut Self>,
+            replacement: Self,
+        ) -> StructProjReplace<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = ::pin_project_lite::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    replacement,
+                );
+                let Self { pinned, unpinned } = &mut *__self_ptr;
+                let result = StructProjReplace {
+                    pinned: ::pin_project_lite::__private::PhantomData,
+                    unpinned: ::pin_project_lite::__private::ptr::read(unpinned),
+                };
+                {
+                    (
+                        ::pin_project_lite::__private::UnsafeDropInPlaceGuard::new(pinned),
+                        (),
+                    );
+                }
+                result
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.rs
new file mode 100644
index 0000000000..cb087530fe
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-all.rs
@@ -0,0 +1,14 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = StructProj]
+    #[project_ref = StructProjRef]
+    #[project_replace = StructProjReplace]
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.expanded.rs
new file mode 100644
index 0000000000..aaa41cd080
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.expanded.rs
@@ -0,0 +1,84 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProj<'__pin, T, U>
+where
+    Struct<T, U>: '__pin,
+{
+    pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+    unpinned: &'__pin mut (U),
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> StructProj<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                StructProj {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjectionRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.rs
new file mode 100644
index 0000000000..59db44530a
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-mut.rs
@@ -0,0 +1,12 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = StructProj]
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.expanded.rs
new file mode 100644
index 0000000000..8ab318cfb8
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.expanded.rs
@@ -0,0 +1,84 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Projection {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjectionRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.rs
new file mode 100644
index 0000000000..e5447c70a6
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-none.rs
@@ -0,0 +1,11 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.expanded.rs
new file mode 100644
index 0000000000..3d97ab8fae
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.expanded.rs
@@ -0,0 +1,84 @@
+use pin_project_lite::pin_project;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+struct StructProjRef<'__pin, T, U>
+where
+    Struct<T, U>: '__pin,
+{
+    pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+    unpinned: &'__pin (U),
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Projection {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> StructProjRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                StructProjRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.rs b/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.rs
new file mode 100644
index 0000000000..6821af8274
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/naming/struct-ref.rs
@@ -0,0 +1,12 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project_ref = StructProjRef]
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.expanded.rs
new file mode 100644
index 0000000000..665ff63386
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.expanded.rs
@@ -0,0 +1,95 @@
+use pin_project_lite::pin_project;
+use std::pin::Pin;
+enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProj<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+enum EnumProjRef<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> EnumProj<'__pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => EnumProj::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> EnumProjRef<'__pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => EnumProjRef::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    impl<T, U> ::pin_project_lite::__private::Drop for Enum<T, U> {
+        fn drop(&mut self) {
+            fn __drop_inner<T, U>(this: ::pin_project_lite::__private::Pin<&mut Enum<T, U>>) {
+                fn __drop_inner() {}
+                let _ = this;
+            }
+            let pinned_self: ::pin_project_lite::__private::Pin<&mut Self> =
+                unsafe { ::pin_project_lite::__private::Pin::new_unchecked(self) };
+            __drop_inner(pinned_self);
+        }
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.rs b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.rs
new file mode 100644
index 0000000000..1855cb7a16
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/enum.rs
@@ -0,0 +1,22 @@
+use pin_project_lite::pin_project;
+use std::pin::Pin;
+
+pin_project! {
+    #[project = EnumProj]
+    #[project_ref = EnumProjRef]
+    enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+    impl<T, U> PinnedDrop for Enum<T, U> {
+        fn drop(this: Pin<&mut Self>) {
+            let _ = this;
+        }
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.expanded.rs
new file mode 100644
index 0000000000..5b82b7a19c
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.expanded.rs
@@ -0,0 +1,92 @@
+use pin_project_lite::pin_project;
+use std::pin::Pin;
+struct Struct<T, U> {
+    pinned: T,
+    unpinned: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Projection {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjectionRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    impl<T, U> ::pin_project_lite::__private::Drop for Struct<T, U> {
+        fn drop(&mut self) {
+            fn __drop_inner<T, U>(this: ::pin_project_lite::__private::Pin<&mut Struct<T, U>>) {
+                fn __drop_inner() {}
+                let _ = this;
+            }
+            let pinned_self: ::pin_project_lite::__private::Pin<&mut Self> =
+                unsafe { ::pin_project_lite::__private::Pin::new_unchecked(self) };
+            __drop_inner(pinned_self);
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.rs b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.rs
new file mode 100644
index 0000000000..0cc7567690
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pinned_drop/struct.rs
@@ -0,0 +1,17 @@
+use pin_project_lite::pin_project;
+use std::pin::Pin;
+
+pin_project! {
+    struct Struct<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+    impl<T, U> PinnedDrop for Struct<T, U> {
+        fn drop(this: Pin<&mut Self>) {
+            let _ = this;
+        }
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pub/enum.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/pub/enum.expanded.rs
new file mode 100644
index 0000000000..6f190cba08
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pub/enum.expanded.rs
@@ -0,0 +1,87 @@
+use pin_project_lite::pin_project;
+pub enum Enum<T, U> {
+    Struct { pinned: T, unpinned: U },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+pub(crate) enum EnumProj<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        unpinned: &'__pin mut (U),
+    },
+    Unit,
+}
+#[allow(dead_code)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::mut_mut)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::ref_option_ref)]
+#[allow(clippy::type_repetition_in_bounds)]
+pub(crate) enum EnumProjRef<'__pin, T, U>
+where
+    Enum<T, U>: '__pin,
+{
+    Struct {
+        pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        unpinned: &'__pin (U),
+    },
+    Unit,
+}
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    impl<T, U> Enum<T, U> {
+        pub(crate) fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> EnumProj<'__pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => EnumProj::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        pub(crate) fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> EnumProjRef<'__pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => EnumProjRef::Struct {
+                        pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                        unpinned: unpinned,
+                    },
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    pub struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        Struct: (T, ::pin_project_lite::__private::AlwaysUnpin<U>),
+        Unit: (),
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Enum<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Enum<T, U> {}
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pub/enum.rs b/third_party/rust/pin-project-lite/tests/expand/pub/enum.rs
new file mode 100644
index 0000000000..d3968afdf2
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pub/enum.rs
@@ -0,0 +1,16 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    #[project = EnumProj]
+    #[project_ref = EnumProjRef]
+    pub enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pub/struct.expanded.rs b/third_party/rust/pin-project-lite/tests/expand/pub/struct.expanded.rs
new file mode 100644
index 0000000000..7b5826d149
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pub/struct.expanded.rs
@@ -0,0 +1,84 @@
+use pin_project_lite::pin_project;
+pub struct Struct<T, U> {
+    pub pinned: T,
+    pub unpinned: U,
+}
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    pub(crate) struct Projection<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pub pinned: ::pin_project_lite::__private::Pin<&'__pin mut (T)>,
+        pub unpinned: &'__pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(single_use_lifetimes)]
+    #[allow(clippy::unknown_clippy_lints)]
+    #[allow(clippy::mut_mut)]
+    #[allow(clippy::redundant_pub_crate)]
+    #[allow(clippy::ref_option_ref)]
+    #[allow(clippy::type_repetition_in_bounds)]
+    pub(crate) struct ProjectionRef<'__pin, T, U>
+    where
+        Struct<T, U>: '__pin,
+    {
+        pub pinned: ::pin_project_lite::__private::Pin<&'__pin (T)>,
+        pub unpinned: &'__pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        pub(crate) fn project<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
+        ) -> Projection<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Projection {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+        pub(crate) fn project_ref<'__pin>(
+            self: ::pin_project_lite::__private::Pin<&'__pin Self>,
+        ) -> ProjectionRef<'__pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjectionRef {
+                    pinned: ::pin_project_lite::__private::Pin::new_unchecked(pinned),
+                    unpinned: unpinned,
+                }
+            }
+        }
+    }
+    #[allow(non_snake_case)]
+    pub struct __Origin<'__pin, T, U> {
+        __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
+        pinned: T,
+        unpinned: ::pin_project_lite::__private::AlwaysUnpin<U>,
+    }
+    impl<'__pin, T, U> ::pin_project_lite::__private::Unpin for Struct<T, U> where
+        __Origin<'__pin, T, U>: ::pin_project_lite::__private::Unpin
+    {
+    }
+    trait MustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
+    impl<T, U> MustNotImplDrop for Struct<T, U> {}
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expand/pub/struct.rs b/third_party/rust/pin-project-lite/tests/expand/pub/struct.rs
new file mode 100644
index 0000000000..6659096909
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expand/pub/struct.rs
@@ -0,0 +1,11 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    pub struct Struct<T, U> {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/expandtest.rs b/third_party/rust/pin-project-lite/tests/expandtest.rs
new file mode 100644
index 0000000000..3f0d5c1121
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/expandtest.rs
@@ -0,0 +1,43 @@
+#![cfg(not(miri))]
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::{
+    env,
+    process::{Command, ExitStatus, Stdio},
+};
+
+const PATH: &str = "tests/expand/**/*.rs";
+
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn expandtest() {
+    let is_ci = env::var_os("CI").is_some();
+    let cargo = &*env::var("CARGO").unwrap_or_else(|_| "cargo".into());
+    if !has_command(&[cargo, "expand"]) || !has_command(&[cargo, "fmt"]) {
+        if is_ci {
+            panic!("expandtest requires rustfmt and cargo-expand");
+        }
+        return;
+    }
+
+    let args = &["--all-features"];
+    if is_ci {
+        macrotest::expand_without_refresh_args(PATH, args);
+    } else {
+        env::set_var("MACROTEST", "overwrite");
+        macrotest::expand_args(PATH, args);
+    }
+}
+
+fn has_command(command: &[&str]) -> bool {
+    Command::new(command[0])
+        .args(&command[1..])
+        .arg("--version")
+        .stdin(Stdio::null())
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .as_ref()
+        .map(ExitStatus::success)
+        .unwrap_or(false)
+}
diff --git a/third_party/rust/pin-project-lite/tests/include/basic.rs b/third_party/rust/pin-project-lite/tests/include/basic.rs
new file mode 100644
index 0000000000..25121f210b
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/include/basic.rs
@@ -0,0 +1,35 @@
+// default pin_project! is completely safe.
+
+::pin_project_lite::pin_project! {
+    #[derive(Debug)]
+    pub struct DefaultStruct<T, U> {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+}
+
+::pin_project_lite::pin_project! {
+    #[project = DefaultStructProj]
+    #[project_ref = DefaultStructProjRef]
+    #[derive(Debug)]
+    pub struct DefaultStructNamed<T, U> {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+}
+
+::pin_project_lite::pin_project! {
+    #[project = DefaultEnumProj]
+    #[project_ref = DefaultEnumProjRef]
+    #[derive(Debug)]
+    pub enum DefaultEnum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Unit,
+    }
+}
diff --git a/third_party/rust/pin-project-lite/tests/lint.rs b/third_party/rust/pin-project-lite/tests/lint.rs
new file mode 100644
index 0000000000..852f940bcf
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/lint.rs
@@ -0,0 +1,263 @@
+// Check interoperability with rustc and clippy lints.
+
+#![forbid(unsafe_code)]
+// for old compilers
+#![allow(unknown_lints)]
+#![warn(nonstandard_style, rust_2018_idioms, unused)]
+// Note: This does not guarantee compatibility with forbidding these lints in the future.
+// If rustc adds a new lint, we may not be able to keep this.
+#![forbid(future_incompatible, rust_2018_compatibility, rust_2021_compatibility)]
+// lints forbidden as a part of future_incompatible, rust_2018_compatibility, and rust_2021_compatibility are not included in the list below.
+// elided_lifetimes_in_paths, explicit_outlives_requirements, unused_extern_crates:  as a part of rust_2018_idioms
+// unsafe_op_in_unsafe_fn: requires Rust 1.52. and, we don't generate unsafe fn.
+// non_exhaustive_omitted_patterns: unstable
+// unstable_features: no way to generate #![feature(..)] by macros, expect for unstable inner attribute. and this lint is deprecated: https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unstable-features
+// unused_crate_dependencies, must_not_suspend: unrelated
+// unsafe_code: checked in forbid_unsafe module
+#![warn(
+    box_pointers,
+    deprecated_in_future,
+    fuzzy_provenance_casts,
+    lossy_provenance_casts,
+    macro_use_extern_crate,
+    meta_variable_misuse,
+    missing_abi,
+    missing_copy_implementations,
+    missing_debug_implementations,
+    missing_docs,
+    non_ascii_idents,
+    noop_method_call,
+    single_use_lifetimes,
+    trivial_casts,
+    trivial_numeric_casts,
+    unreachable_pub,
+    unused_import_braces,
+    unused_lifetimes,
+    unused_qualifications,
+    unused_results,
+    variant_size_differences
+)]
+#![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::restriction)]
+#![allow(clippy::blanket_clippy_restriction_lints)] // this is a test, so enable all restriction lints intentionally.
+#![allow(clippy::exhaustive_structs, clippy::exhaustive_enums, clippy::single_char_lifetime_names)] // TODO
+
+pub mod basic {
+    include!("include/basic.rs");
+}
+
+pub mod box_pointers {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct {
+            #[pin]
+            pub p: Box<isize>,
+            pub u: Box<isize>,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum {
+            Struct {
+                #[pin]
+                p: Box<isize>,
+                u: Box<isize>,
+            },
+            Unit,
+        }
+    }
+}
+
+pub mod explicit_outlives_requirements {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct<'a, T, U>
+        where
+            T: ?Sized,
+            U: ?Sized,
+        {
+            #[pin]
+            pub pinned: &'a mut T,
+            pub unpinned: &'a mut U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum<'a, T, U>
+        where
+            T: ?Sized,
+            U: ?Sized,
+        {
+            Struct {
+                #[pin]
+                pinned: &'a mut T,
+                unpinned: &'a mut U,
+            },
+            Unit,
+        }
+    }
+}
+
+pub mod variant_size_differences {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[allow(missing_debug_implementations, missing_copy_implementations)] // https://github.com/rust-lang/rust/pull/74060
+        #[allow(variant_size_differences)] // for the type itself
+        #[allow(clippy::large_enum_variant)] // for the type itself
+        pub enum Enum {
+            V1 { f: u8 },
+            V2 { f: [u8; 1024] },
+        }
+    }
+}
+
+pub mod clippy_mut_mut {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct<'a, T, U> {
+            #[pin]
+            pub pinned: &'a mut T,
+            pub unpinned: &'a mut U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum<'a, T, U> {
+            Struct {
+                #[pin]
+                pinned: &'a mut T,
+                unpinned: &'a mut U,
+            },
+            Unit,
+        }
+    }
+}
+
+#[allow(unreachable_pub)]
+mod clippy_redundant_pub_crate {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct<T, U> {
+            #[pin]
+            pub pinned: T,
+            pub unpinned: U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum<T, U> {
+            Struct {
+                #[pin]
+                pinned: T,
+                unpinned: U,
+            },
+            Unit,
+        }
+    }
+}
+
+#[allow(clippy::use_self)]
+pub mod clippy_type_repetition_in_bounds {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct<T, U>
+        where
+            Struct<T, U>: Sized,
+        {
+            #[pin]
+            pub pinned: T,
+            pub unpinned: U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum<T, U>
+        where
+            Enum<T, U>: Sized,
+        {
+            Struct {
+                #[pin]
+                pinned: T,
+                unpinned: U,
+            },
+            Unit,
+        }
+    }
+}
+
+pub mod clippy_used_underscore_binding {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        #[derive(Debug)]
+        pub struct Struct<T, U> {
+            #[pin]
+            pub _pinned: T,
+            pub _unpinned: U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Debug)]
+        pub enum Enum<T, U> {
+            Struct {
+                #[pin]
+                _pinned: T,
+                _unpinned: U,
+            },
+        }
+    }
+}
+
+pub mod clippy_ref_option_ref {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        pub struct Struct<'a> {
+            #[pin]
+            pub _pinned: Option<&'a ()>,
+            pub _unpinned: Option<&'a ()>,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        pub enum Enum<'a> {
+            Struct {
+                #[pin]
+                _pinned: Option<&'a ()>,
+                _unpinned: Option<&'a ()>,
+            },
+        }
+    }
+}
diff --git a/third_party/rust/pin-project-lite/tests/proper_unpin.rs b/third_party/rust/pin-project-lite/tests/proper_unpin.rs
new file mode 100644
index 0000000000..668e975ba9
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/proper_unpin.rs
@@ -0,0 +1,67 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+#[macro_use]
+mod auxiliary;
+
+pub mod default {
+    use std::marker::PhantomPinned;
+
+    use pin_project_lite::pin_project;
+
+    struct Inner<T> {
+        f: T,
+    }
+
+    assert_unpin!(Inner<()>);
+    assert_not_unpin!(Inner<PhantomPinned>);
+
+    pin_project! {
+        struct Struct<T, U> {
+            #[pin]
+            f1: Inner<T>,
+            f2: U,
+        }
+    }
+
+    assert_unpin!(Struct<(), ()>);
+    assert_unpin!(Struct<(), PhantomPinned>);
+    assert_not_unpin!(Struct<PhantomPinned, ()>);
+    assert_not_unpin!(Struct<PhantomPinned, PhantomPinned>);
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum<T, U> {
+            V1 {
+                #[pin]
+                f1: Inner<T>,
+                f2: U,
+            },
+        }
+    }
+
+    assert_unpin!(Enum<(), ()>);
+    assert_unpin!(Enum<(), PhantomPinned>);
+    assert_not_unpin!(Enum<PhantomPinned, ()>);
+    assert_not_unpin!(Enum<PhantomPinned, PhantomPinned>);
+
+    pin_project! {
+        struct TrivialBounds {
+            #[pin]
+            f: PhantomPinned,
+        }
+    }
+
+    assert_not_unpin!(TrivialBounds);
+
+    pin_project! {
+        struct PinRef<'a, T, U> {
+            #[pin]
+            f1: &'a mut Inner<T>,
+            f2: U,
+        }
+    }
+
+    assert_unpin!(PinRef<'_, PhantomPinned, PhantomPinned>);
+}
diff --git a/third_party/rust/pin-project-lite/tests/test.rs b/third_party/rust/pin-project-lite/tests/test.rs
new file mode 100644
index 0000000000..ed9b75c42c
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/test.rs
@@ -0,0 +1,695 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+#[macro_use]
+mod auxiliary;
+
+use core::{
+    marker::{PhantomData, PhantomPinned},
+    pin::Pin,
+};
+
+use pin_project_lite::pin_project;
+
+#[test]
+fn projection() {
+    pin_project! {
+        #[project = StructProj]
+        #[project_ref = StructProjRef]
+        #[project_replace = StructProjReplace]
+        #[derive(Default)]
+        struct Struct<T, U> {
+            #[pin]
+            f1: T,
+            f2: U,
+        }
+    }
+
+    let mut s = Struct { f1: 1, f2: 2 };
+    let mut s_orig = Pin::new(&mut s);
+    let s = s_orig.as_mut().project();
+
+    let _: Pin<&mut i32> = s.f1;
+    assert_eq!(*s.f1, 1);
+    let _: &mut i32 = s.f2;
+    assert_eq!(*s.f2, 2);
+
+    assert_eq!(s_orig.as_ref().f1, 1);
+    assert_eq!(s_orig.as_ref().f2, 2);
+
+    let mut s = Struct { f1: 1, f2: 2 };
+    let mut s = Pin::new(&mut s);
+    {
+        let StructProj { f1, f2 } = s.as_mut().project();
+        let _: Pin<&mut i32> = f1;
+        let _: &mut i32 = f2;
+    }
+    {
+        let StructProjRef { f1, f2 } = s.as_ref().project_ref();
+        let _: Pin<&i32> = f1;
+        let _: &i32 = f2;
+    }
+
+    {
+        let StructProjReplace { f1: PhantomData, f2 } =
+            s.as_mut().project_replace(Struct::default());
+        assert_eq!(f2, 2);
+        let StructProj { f1, f2 } = s.project();
+        assert_eq!(*f1, 0);
+        assert_eq!(*f2, 0);
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[project_replace = EnumProjReplace]
+        #[derive(Eq, PartialEq, Debug)]
+        enum Enum<C, D> {
+            Struct {
+                #[pin]
+                f1: C,
+                f2: D,
+            },
+            Unit,
+        }
+    }
+
+    let mut e = Enum::Struct { f1: 1, f2: 2 };
+    let mut e = Pin::new(&mut e);
+
+    match e.as_mut().project() {
+        EnumProj::Struct { f1, f2 } => {
+            let _: Pin<&mut i32> = f1;
+            assert_eq!(*f1, 1);
+            let _: &mut i32 = f2;
+            assert_eq!(*f2, 2);
+        }
+        EnumProj::Unit => unreachable!(),
+    }
+
+    assert_eq!(&*e, &Enum::Struct { f1: 1, f2: 2 });
+
+    if let EnumProj::Struct { f1, f2 } = e.as_mut().project() {
+        let _: Pin<&mut i32> = f1;
+        assert_eq!(*f1, 1);
+        let _: &mut i32 = f2;
+        assert_eq!(*f2, 2);
+    }
+
+    if let EnumProjReplace::Struct { f1: PhantomData, f2 } = e.as_mut().project_replace(Enum::Unit)
+    {
+        assert_eq!(f2, 2);
+    }
+}
+
+#[test]
+fn enum_project_set() {
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        #[derive(Eq, PartialEq, Debug)]
+        enum Enum {
+            V1 { #[pin] f: u8 },
+            V2 { f: bool },
+        }
+    }
+
+    let mut e = Enum::V1 { f: 25 };
+    let mut e_orig = Pin::new(&mut e);
+    let e_proj = e_orig.as_mut().project();
+
+    match e_proj {
+        EnumProj::V1 { f } => {
+            let new_e = Enum::V2 { f: f.as_ref().get_ref() == &25 };
+            e_orig.set(new_e);
+        }
+        EnumProj::V2 { .. } => unreachable!(),
+    }
+
+    assert_eq!(e, Enum::V2 { f: true });
+}
+
+#[test]
+fn where_clause() {
+    pin_project! {
+        struct Struct<T>
+        where
+            T: Copy,
+        {
+            f: T,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum<T>
+        where
+            T: Copy,
+        {
+            V { f: T },
+        }
+    }
+}
+
+#[test]
+fn where_clause_and_associated_type_field() {
+    pin_project! {
+        struct Struct1<I>
+        where
+            I: Iterator,
+        {
+            #[pin]
+            f1: I,
+            f2: I::Item,
+        }
+    }
+
+    pin_project! {
+        struct Struct2<I, J>
+        where
+            I: Iterator<Item = J>,
+        {
+            #[pin]
+            f1: I,
+            f2: J,
+        }
+    }
+
+    pin_project! {
+        pub struct Struct3<T>
+        where
+            T: 'static,
+        {
+            f: T,
+        }
+    }
+
+    trait Static: 'static {}
+
+    impl<T> Static for Struct3<T> {}
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum<I>
+        where
+            I: Iterator,
+        {
+            V1 { #[pin] f: I },
+            V2 { f: I::Item },
+        }
+    }
+}
+
+#[test]
+fn derive_copy() {
+    pin_project! {
+        #[derive(Clone, Copy)]
+        struct Struct<T> {
+            f: T,
+        }
+    }
+
+    fn is_copy<T: Copy>() {}
+
+    is_copy::<Struct<u8>>();
+}
+
+#[test]
+fn move_out() {
+    struct NotCopy;
+
+    pin_project! {
+        struct Struct {
+            f: NotCopy,
+        }
+    }
+
+    let x = Struct { f: NotCopy };
+    let _val: NotCopy = x.f;
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum {
+            V { f: NotCopy },
+        }
+    }
+
+    let x = Enum::V { f: NotCopy };
+    #[allow(clippy::infallible_destructuring_match)]
+    let _val: NotCopy = match x {
+        Enum::V { f } => f,
+    };
+}
+
+#[test]
+fn trait_bounds_on_type_generics() {
+    pin_project! {
+        pub struct Struct1<'a, T: ?Sized> {
+            f: &'a mut T,
+        }
+    }
+
+    pin_project! {
+        pub struct Struct2<'a, T: ::core::fmt::Debug> {
+            f: &'a mut T,
+        }
+    }
+
+    pin_project! {
+        pub struct Struct3<'a, T: core::fmt::Debug> {
+            f: &'a mut T,
+        }
+    }
+
+    // pin_project! {
+    //     pub struct Struct4<'a, T: core::fmt::Debug + core::fmt::Display> {
+    //         f: &'a mut T,
+    //     }
+    // }
+
+    // pin_project! {
+    //     pub struct Struct5<'a, T: core::fmt::Debug + ?Sized> {
+    //         f: &'a mut T,
+    //     }
+    // }
+
+    pin_project! {
+        pub struct Struct6<'a, T: core::fmt::Debug = [u8; 16]> {
+            f: &'a mut T,
+        }
+    }
+
+    let _: Struct6<'_> = Struct6 { f: &mut [0_u8; 16] };
+
+    pin_project! {
+        pub struct Struct7<T: 'static> {
+            f: T,
+        }
+    }
+
+    trait Static: 'static {}
+
+    impl<T> Static for Struct7<T> {}
+
+    pin_project! {
+        pub struct Struct8<'a, 'b: 'a> {
+            f1: &'a u8,
+            f2: &'b u8,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum<'a, T: ?Sized> {
+            V { f: &'a mut T },
+        }
+    }
+}
+
+#[test]
+fn private_type_in_public_type() {
+    pin_project! {
+        pub struct PublicStruct<T> {
+            #[pin]
+            inner: PrivateStruct<T>,
+        }
+    }
+
+    struct PrivateStruct<T>(T);
+}
+
+#[allow(clippy::needless_lifetimes)]
+#[test]
+fn lifetime_project() {
+    pin_project! {
+        struct Struct1<T, U> {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        }
+    }
+
+    pin_project! {
+        struct Struct2<'a, T, U> {
+            #[pin]
+            pinned: &'a T,
+            unpinned: U,
+        }
+    }
+
+    pin_project! {
+        #[project = EnumProj]
+        #[project_ref = EnumProjRef]
+        enum Enum<T, U> {
+            V {
+                #[pin]
+                pinned: T,
+                unpinned: U,
+            },
+        }
+    }
+
+    impl<T, U> Struct1<T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut T> {
+            self.project().pinned
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut T> {
+            self.project().pinned
+        }
+    }
+
+    impl<'b, T, U> Struct2<'b, T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a &'b T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut &'b T> {
+            self.project().pinned
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&&'b T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut &'b T> {
+            self.project().pinned
+        }
+    }
+
+    impl<T, U> Enum<T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a T> {
+            match self.project_ref() {
+                EnumProjRef::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut T> {
+            match self.project() {
+                EnumProj::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&T> {
+            match self.project_ref() {
+                EnumProjRef::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut T> {
+            match self.project() {
+                EnumProj::V { pinned, .. } => pinned,
+            }
+        }
+    }
+}
+
+mod visibility {
+    use pin_project_lite::pin_project;
+
+    pin_project! {
+        pub(crate) struct S {
+            pub f: u8,
+        }
+    }
+}
+
+#[test]
+fn visibility() {
+    let mut x = visibility::S { f: 0 };
+    let x = Pin::new(&mut x);
+    let y = x.as_ref().project_ref();
+    let _: &u8 = y.f;
+    let y = x.project();
+    let _: &mut u8 = y.f;
+}
+
+#[test]
+fn trivial_bounds() {
+    pin_project! {
+        pub struct NoGenerics {
+            #[pin]
+            f: PhantomPinned,
+        }
+    }
+
+    assert_not_unpin!(NoGenerics);
+}
+
+#[test]
+fn dst() {
+    pin_project! {
+        pub struct Struct1<T: ?Sized> {
+            f: T,
+        }
+    }
+
+    let mut x = Struct1 { f: 0_u8 };
+    let x: Pin<&mut Struct1<dyn core::fmt::Debug>> = Pin::new(&mut x as _);
+    let _: &mut (dyn core::fmt::Debug) = x.project().f;
+
+    pin_project! {
+        pub struct Struct2<T: ?Sized> {
+            #[pin]
+            f: T,
+        }
+    }
+
+    let mut x = Struct2 { f: 0_u8 };
+    let x: Pin<&mut Struct2<dyn core::fmt::Debug + Unpin>> = Pin::new(&mut x as _);
+    let _: Pin<&mut (dyn core::fmt::Debug + Unpin)> = x.project().f;
+
+    pin_project! {
+        struct Struct3<T>
+        where
+            T: ?Sized,
+        {
+            f: T,
+        }
+    }
+
+    pin_project! {
+        struct Struct4<T>
+        where
+            T: ?Sized,
+        {
+            #[pin]
+            f: T,
+        }
+    }
+
+    pin_project! {
+        struct Struct11<'a, T: ?Sized, U: ?Sized> {
+            f1: &'a mut T,
+            f2: U,
+        }
+    }
+}
+
+#[test]
+fn dyn_type() {
+    pin_project! {
+        struct Struct1 {
+            f: dyn core::fmt::Debug,
+        }
+    }
+
+    pin_project! {
+        struct Struct2 {
+            #[pin]
+            f: dyn core::fmt::Debug,
+        }
+    }
+
+    pin_project! {
+        struct Struct3 {
+            f: dyn core::fmt::Debug + Send,
+        }
+    }
+
+    pin_project! {
+        struct Struct4 {
+            #[pin]
+            f: dyn core::fmt::Debug + Send,
+        }
+    }
+}
+
+#[test]
+fn no_infer_outlives() {
+    trait Trait<X> {
+        type Y;
+    }
+
+    struct Struct1<A>(A);
+
+    impl<X, T> Trait<X> for Struct1<T> {
+        type Y = Option<T>;
+    }
+
+    pin_project! {
+        struct Struct2<A, B> {
+            _f: <Struct1<A> as Trait<B>>::Y,
+        }
+    }
+}
+
+// https://github.com/taiki-e/pin-project-lite/issues/31
+#[test]
+fn trailing_comma() {
+    pub trait T {}
+
+    pin_project! {
+        pub struct S1<
+            A: T,
+            B: T,
+        > {
+            f: (A, B),
+        }
+    }
+
+    pin_project! {
+        pub struct S2<
+            A,
+            B,
+        >
+        where
+            A: T,
+            B: T,
+        {
+            f: (A, B),
+        }
+    }
+
+    pin_project! {
+        #[allow(explicit_outlives_requirements)]
+        pub struct S3<
+            'a,
+            A: 'a,
+            B: 'a,
+        > {
+            f: &'a (A, B),
+        }
+    }
+
+    // pin_project! {
+    //     pub struct S4<
+    //         'a,
+    //         'b: 'a, // <-----
+    //     > {
+    //         f: &'a &'b (),
+    //     }
+    // }
+}
+
+#[test]
+fn attrs() {
+    pin_project! {
+        /// dox1
+        #[derive(Clone)]
+        #[project = StructProj]
+        #[project_ref = StructProjRef]
+        /// dox2
+        #[derive(Debug)]
+        /// dox3
+        struct Struct {
+            // TODO
+            // /// dox4
+            f: ()
+        }
+    }
+
+    pin_project! {
+        #[project = Enum1Proj]
+        #[project_ref = Enum1ProjRef]
+        enum Enum1 {
+            #[cfg(not(any()))]
+            V {
+                f: ()
+            },
+        }
+    }
+
+    pin_project! {
+        /// dox1
+        #[derive(Clone)]
+        #[project = Enum2Proj]
+        #[project_ref = Enum2ProjRef]
+        /// dox2
+        #[derive(Debug)]
+        /// dox3
+        enum Enum2 {
+            /// dox4
+            V1 {
+                // TODO
+                // /// dox5
+                f: ()
+            },
+            /// dox6
+            V2,
+        }
+    }
+}
+
+#[test]
+fn pinned_drop() {
+    pin_project! {
+        pub struct Struct1<'a> {
+            was_dropped: &'a mut bool,
+            #[pin]
+            field: u8,
+        }
+        impl PinnedDrop for Struct1<'_> {
+            fn drop(this: Pin<&mut Self>) {
+                **this.project().was_dropped = true;
+            }
+        }
+    }
+
+    let mut was_dropped = false;
+    drop(Struct1 { was_dropped: &mut was_dropped, field: 42 });
+    assert!(was_dropped);
+
+    pin_project! {
+        pub struct Struct2<'a> {
+            was_dropped: &'a mut bool,
+            #[pin]
+            field: u8,
+        }
+        impl PinnedDrop for Struct2<'_> {
+            fn drop(mut this: Pin<&mut Self>) {
+                **this.as_mut().project().was_dropped = true;
+            }
+        }
+    }
+
+    trait Service<Request> {
+        type Error;
+    }
+
+    pin_project! {
+        struct Struct3<'a, T, Request>
+        where
+            T: Service<Request>,
+            T::Error: std::error::Error,
+        {
+            was_dropped: &'a mut bool,
+            #[pin]
+            field: T,
+            req: Request,
+        }
+
+        impl<T, Request> PinnedDrop for Struct3<'_, T, Request>
+        where
+            T: Service<Request>,
+            T::Error: std::error::Error,
+        {
+            fn drop(mut this: Pin<&mut Self>) {
+                **this.as_mut().project().was_dropped = true;
+            }
+        }
+    }
+}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.rs
new file mode 100644
index 0000000000..870059d62f
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.rs
@@ -0,0 +1,15 @@
+use pin_project_lite::pin_project;
+
+pin_project! { //~ ERROR E0119
+    struct Foo<T, U> {
+        #[pin]
+        future: T,
+        field: U,
+    }
+}
+
+impl<T, U> Drop for Foo<T, U> {
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.stderr
new file mode 100644
index 0000000000..66872bd4bd
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-drop.stderr
@@ -0,0 +1,16 @@
+error[E0119]: conflicting implementations of trait `_::MustNotImplDrop` for type `Foo<_, _>`
+ --> tests/ui/pin_project/conflict-drop.rs:3:1
+  |
+3 | / pin_project! { //~ ERROR E0119
+4 | |     struct Foo<T, U> {
+5 | |         #[pin]
+6 | |         future: T,
+7 | |         field: U,
+8 | |     }
+9 | | }
+  | | ^
+  | | |
+  | |_first implementation here
+  |   conflicting implementation for `Foo<_, _>`
+  |
+  = note: this error originates in the macro `$crate::__pin_project_make_drop_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.rs
new file mode 100644
index 0000000000..f702f064de
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.rs
@@ -0,0 +1,40 @@
+use pin_project_lite::pin_project;
+
+// The same implementation.
+
+pin_project! { //~ ERROR E0119
+    struct Foo<T, U> {
+        #[pin]
+        future: T,
+        field: U,
+    }
+}
+
+// conflicting implementations
+impl<T, U> Unpin for Foo<T, U> where T: Unpin {} // Conditional Unpin impl
+
+// The implementation that under different conditions.
+
+pin_project! { //~ ERROR E0119
+    struct Bar<T, U> {
+        #[pin]
+        future: T,
+        field: U,
+    }
+}
+
+// conflicting implementations
+impl<T, U> Unpin for Bar<T, U> {} // Non-conditional Unpin impl
+
+pin_project! { //~ ERROR E0119
+    struct Baz<T, U> {
+        #[pin]
+        future: T,
+        field: U,
+    }
+}
+
+// conflicting implementations
+impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {} // Conditional Unpin impl
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.stderr
new file mode 100644
index 0000000000..bd30fafdd3
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/conflict-unpin.stderr
@@ -0,0 +1,50 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Foo<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:5:1
+   |
+5  | / pin_project! { //~ ERROR E0119
+6  | |     struct Foo<T, U> {
+7  | |         #[pin]
+8  | |         future: T,
+9  | |         field: U,
+10 | |     }
+11 | | }
+   | |_^ conflicting implementation for `Foo<_, _>`
+...
+14 |   impl<T, U> Unpin for Foo<T, U> where T: Unpin {} // Conditional Unpin impl
+   |   --------------------------------------------- first implementation here
+   |
+   = note: this error originates in the macro `$crate::__pin_project_make_unpin_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Bar<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:18:1
+   |
+18 | / pin_project! { //~ ERROR E0119
+19 | |     struct Bar<T, U> {
+20 | |         #[pin]
+21 | |         future: T,
+22 | |         field: U,
+23 | |     }
+24 | | }
+   | |_^ conflicting implementation for `Bar<_, _>`
+...
+27 |   impl<T, U> Unpin for Bar<T, U> {} // Non-conditional Unpin impl
+   |   ------------------------------ first implementation here
+   |
+   = note: this error originates in the macro `$crate::__pin_project_make_unpin_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Baz<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:29:1
+   |
+29 | / pin_project! { //~ ERROR E0119
+30 | |     struct Baz<T, U> {
+31 | |         #[pin]
+32 | |         future: T,
+33 | |         field: U,
+34 | |     }
+35 | | }
+   | |_^ conflicting implementation for `Baz<_, _>`
+...
+38 |   impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {} // Conditional Unpin impl
+   |   -------------------------------------------- first implementation here
+   |
+   = note: this error originates in the macro `$crate::__pin_project_make_unpin_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.rs
new file mode 100644
index 0000000000..64b397a37e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.rs
@@ -0,0 +1,93 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Generics1<T: 'static : Sized> { //~ ERROR no rules expected the token `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics2<T: 'static : ?Sized> { //~ ERROR no rules expected the token `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct Generics6<T: ?Sized : Sized> { //~ ERROR no rules expected the token `Sized`
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause1<T>
+    where
+        T: 'static : Sized //~ ERROR no rules expected the token `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause2<T>
+    where
+        T: 'static : ?Sized //~ ERROR no rules expected the token `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause3<T>
+    where
+        T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause4<T>
+    where
+        T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause5<T>
+    where
+        T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+    {
+        field: T,
+    }
+}
+
+pin_project! {
+    struct WhereClause6<T>
+    where
+        T: ?Sized : Sized //~ ERROR no rules expected the token `Sized`
+    {
+        field: T,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.stderr
new file mode 100644
index 0000000000..40e79bf928
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid-bounds.stderr
@@ -0,0 +1,428 @@
+error: no rules expected the token `:`
+ --> tests/ui/pin_project/invalid-bounds.rs:4:33
+  |
+4 |     struct Generics1<T: 'static : Sized> { //~ ERROR no rules expected the token `:`
+  |                                 ^ no rules expected this token in macro call
+
+error: no rules expected the token `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:10:33
+   |
+10 |     struct Generics2<T: 'static : ?Sized> { //~ ERROR no rules expected the token `:`
+   |                                 ^ no rules expected this token in macro call
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+17 | |         field: T,
+18 | |     }
+19 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+17 | |         field: T,
+18 | |     }
+19 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, `=`, or `>`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+17 | |         field: T,
+18 | |     }
+19 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     struct Generics3<T: Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+17 | |         field: T,
+18 | |     }
+19 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+23 | |         field: T,
+24 | |     }
+25 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+23 | |         field: T,
+24 | |     }
+25 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, `=`, or `>`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+23 | |         field: T,
+24 | |     }
+25 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     struct Generics4<T: ?Sized : 'static> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+23 | |         field: T,
+24 | |     }
+25 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:27:1
+   |
+27 | / pin_project! {
+28 | |     struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+29 | |         field: T,
+30 | |     }
+31 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:27:1
+   |
+27 | / pin_project! {
+28 | |     struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+29 | |         field: T,
+30 | |     }
+31 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, `=`, or `>`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:27:1
+   |
+27 | / pin_project! {
+28 | |     struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+29 | |         field: T,
+30 | |     }
+31 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, `=`, or `>`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:27:1
+   |
+27 | / pin_project! {
+28 | |     struct Generics5<T: Sized : ?Sized> { //~ ERROR expected one of `+`, `,`, `=`, or `>`, found `:`
+29 | |         field: T,
+30 | |     }
+31 | | }
+   | | ^
+   | | |
+   | | expected one of `+`, `,`, `=`, or `>`
+   | |_unexpected token
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `Sized`
+  --> tests/ui/pin_project/invalid-bounds.rs:34:34
+   |
+34 |     struct Generics6<T: ?Sized : Sized> { //~ ERROR no rules expected the token `Sized`
+   |                                  ^^^^^ no rules expected this token in macro call
+
+error: no rules expected the token `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:42:20
+   |
+42 |         T: 'static : Sized //~ ERROR no rules expected the token `:`
+   |                    ^ no rules expected this token in macro call
+
+error: no rules expected the token `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:51:20
+   |
+51 |         T: 'static : ?Sized //~ ERROR no rules expected the token `:`
+   |                    ^ no rules expected this token in macro call
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:57:1
+   |
+57 | / pin_project! {
+58 | |     struct WhereClause3<T>
+59 | |     where
+60 | |         T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+63 | |     }
+64 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, or `{`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:57:1
+   |
+57 | / pin_project! {
+58 | |     struct WhereClause3<T>
+59 | |     where
+60 | |         T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+63 | |     }
+64 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, or `{`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:57:1
+   |
+57 | / pin_project! {
+58 | |     struct WhereClause3<T>
+59 | |     where
+60 | |         T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+63 | |     }
+64 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:57:1
+   |
+57 | / pin_project! {
+58 | |     struct WhereClause3<T>
+59 | |     where
+60 | |         T: Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+63 | |     }
+64 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:66:1
+   |
+66 | / pin_project! {
+67 | |     struct WhereClause4<T>
+68 | |     where
+69 | |         T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+72 | |     }
+73 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, or `{`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:66:1
+   |
+66 | / pin_project! {
+67 | |     struct WhereClause4<T>
+68 | |     where
+69 | |         T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+72 | |     }
+73 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, or `{`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:66:1
+   |
+66 | / pin_project! {
+67 | |     struct WhereClause4<T>
+68 | |     where
+69 | |         T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+72 | |     }
+73 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:66:1
+   |
+66 | / pin_project! {
+67 | |     struct WhereClause4<T>
+68 | |     where
+69 | |         T: ?Sized : 'static //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+72 | |     }
+73 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:75:1
+   |
+75 | / pin_project! {
+76 | |     struct WhereClause5<T>
+77 | |     where
+78 | |         T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+81 | |     }
+82 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected one of `+`, `,`, or `{`, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:75:1
+   |
+75 | / pin_project! {
+76 | |     struct WhereClause5<T>
+77 | |     where
+78 | |         T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+81 | |     }
+82 | | }
+   | | ^
+   | | |
+   | |_expected one of `+`, `,`, or `{`
+   |   unexpected token
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:75:1
+   |
+75 | / pin_project! {
+76 | |     struct WhereClause5<T>
+77 | |     where
+78 | |         T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+81 | |     }
+82 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected `{` after struct name, found `:`
+  --> tests/ui/pin_project/invalid-bounds.rs:75:1
+   |
+75 | / pin_project! {
+76 | |     struct WhereClause5<T>
+77 | |     where
+78 | |         T: Sized : ?Sized //~ ERROR expected `where`, or `{` after struct name, found `:`
+...  |
+81 | |     }
+82 | | }
+   | | ^
+   | | |
+   | |_expected `{` after struct name
+   |   in this macro invocation
+   |
+   = note: this error originates in the macro `$crate::__pin_project_parse_generics` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `Sized`
+  --> tests/ui/pin_project/invalid-bounds.rs:87:21
+   |
+87 |         T: ?Sized : Sized //~ ERROR no rules expected the token `Sized`
+   |                     ^^^^^ no rules expected this token in macro call
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.rs
new file mode 100644
index 0000000000..e0ea61d4f7
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.rs
@@ -0,0 +1,25 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct A<T> {
+        #[pin()] //~ ERROR no rules expected the token `(`
+        pinned: T,
+    }
+}
+
+pin_project! {
+    #[pin] //~ ERROR cannot find attribute `pin` in this scope
+    struct B<T> {
+        pinned: T,
+    }
+}
+
+pin_project! {
+    struct C<T> {
+        #[pin]
+        #[pin] //~ ERROR no rules expected the token `#`
+        pinned: T,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.stderr
new file mode 100644
index 0000000000..623a886722
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/invalid.stderr
@@ -0,0 +1,59 @@
+error: no rules expected the token `struct`
+ --> tests/ui/pin_project/invalid.rs:3:1
+  |
+3 | / pin_project! {
+4 | |     struct A<T> {
+5 | |         #[pin()] //~ ERROR no rules expected the token `(`
+6 | |         pinned: T,
+7 | |     }
+8 | | }
+  | |_^ no rules expected this token in macro call
+  |
+  = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `struct`
+ --> tests/ui/pin_project/invalid.rs:3:1
+  |
+3 | / pin_project! {
+4 | |     struct A<T> {
+5 | |         #[pin()] //~ ERROR no rules expected the token `(`
+6 | |         pinned: T,
+7 | |     }
+8 | | }
+  | |_^ no rules expected this token in macro call
+  |
+  = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `struct`
+  --> tests/ui/pin_project/invalid.rs:17:1
+   |
+17 | / pin_project! {
+18 | |     struct C<T> {
+19 | |         #[pin]
+20 | |         #[pin] //~ ERROR no rules expected the token `#`
+21 | |         pinned: T,
+22 | |     }
+23 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `struct`
+  --> tests/ui/pin_project/invalid.rs:17:1
+   |
+17 | / pin_project! {
+18 | |     struct C<T> {
+19 | |         #[pin]
+20 | |         #[pin] //~ ERROR no rules expected the token `#`
+21 | |         pinned: T,
+22 | |     }
+23 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot find attribute `pin` in this scope
+  --> tests/ui/pin_project/invalid.rs:11:7
+   |
+11 |     #[pin] //~ ERROR cannot find attribute `pin` in this scope
+   |       ^^^
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.rs
new file mode 100644
index 0000000000..117c18d74c
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.rs
@@ -0,0 +1,10 @@
+use pin_project_lite::pin_project;
+
+pin_project! { //~ ERROR E0263,E0496
+    pub struct Foo<'__pin, T> {
+        #[pin]
+        field: &'__pin mut T,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.stderr
new file mode 100644
index 0000000000..35074d0753
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_lifetime_names.stderr
@@ -0,0 +1,75 @@
+error[E0263]: lifetime name `'__pin` declared twice in the same scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:4:20
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ^^^^^^ declared twice
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_- previous declaration here
+
+error[E0263]: lifetime name `'__pin` declared twice in the same scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:4:20
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ^^^^^^ declared twice
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_- previous declaration here
+
+error[E0263]: lifetime name `'__pin` declared twice in the same scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:4:20
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ^^^^^^ declared twice
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_- previous declaration here
+
+error[E0496]: lifetime name `'__pin` shadows a lifetime name that is already in scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:3:1
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ------ first declared here
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_^ lifetime `'__pin` already in scope
+  |
+  = note: this error originates in the macro `$crate::__pin_project_struct_make_proj_method` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0496]: lifetime name `'__pin` shadows a lifetime name that is already in scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:3:1
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ------ first declared here
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_^ lifetime `'__pin` already in scope
+  |
+  = note: this error originates in the macro `$crate::__pin_project_struct_make_proj_method` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0263]: lifetime name `'__pin` declared twice in the same scope
+ --> tests/ui/pin_project/overlapping_lifetime_names.rs:4:20
+  |
+3 | / pin_project! { //~ ERROR E0263,E0496
+4 | |     pub struct Foo<'__pin, T> {
+  | |                    ^^^^^^ declared twice
+5 | |         #[pin]
+6 | |         field: &'__pin mut T,
+7 | |     }
+8 | | }
+  | |_- previous declaration here
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.rs
new file mode 100644
index 0000000000..25131d17d1
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.rs
@@ -0,0 +1,20 @@
+use std::marker::PhantomPinned;
+
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Foo<T> {
+        #[pin]
+        inner: T,
+    }
+}
+
+struct __Origin {}
+
+impl Unpin for __Origin {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Foo<PhantomPinned>>(); //~ ERROR E0277
+}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.stderr
new file mode 100644
index 0000000000..303e7cbb58
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/overlapping_unpin_struct.stderr
@@ -0,0 +1,33 @@
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:19:5
+   |
+19 |     is_unpin::<Foo<PhantomPinned>>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ within `_::__Origin<'_, PhantomPinned>`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `_::__Origin<'_, PhantomPinned>`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:5:1
+   |
+5  | / pin_project! {
+6  | |     struct Foo<T> {
+7  | |         #[pin]
+8  | |         inner: T,
+9  | |     }
+10 | | }
+   | |_^
+note: required because of the requirements on the impl of `Unpin` for `Foo<PhantomPinned>`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:5:1
+   |
+5  | / pin_project! {
+6  | |     struct Foo<T> {
+7  | |         #[pin]
+8  | |         inner: T,
+9  | |     }
+10 | | }
+   | |_^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:16:16
+   |
+16 | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+   = note: this error originates in the macro `$crate::__pin_project_make_unpin_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.rs
new file mode 100644
index 0000000000..50afb118c8
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.rs
@@ -0,0 +1,21 @@
+#![allow(unaligned_references)]
+
+use pin_project_lite::pin_project;
+
+pin_project! { //~ ERROR reference to packed field is unaligned
+    #[repr(packed, C)]
+    struct Packed {
+        #[pin]
+        field: u16,
+    }
+}
+
+pin_project! { //~ ERROR reference to packed field is unaligned
+    #[repr(packed(2))]
+    struct PackedN {
+        #[pin]
+        field: u32,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.stderr
new file mode 100644
index 0000000000..81fb4f1fcc
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/packed.stderr
@@ -0,0 +1,57 @@
+error: reference to packed field is unaligned
+  --> tests/ui/pin_project/packed.rs:5:1
+   |
+5  | / pin_project! { //~ ERROR reference to packed field is unaligned
+6  | |     #[repr(packed, C)]
+7  | |     struct Packed {
+8  | |         #[pin]
+9  | |         field: u16,
+10 | |     }
+11 | | }
+   | |_^
+   |
+note: the lint level is defined here
+  --> tests/ui/pin_project/packed.rs:5:1
+   |
+5  | / pin_project! { //~ ERROR reference to packed field is unaligned
+6  | |     #[repr(packed, C)]
+7  | |     struct Packed {
+8  | |         #[pin]
+9  | |         field: u16,
+10 | |     }
+11 | | }
+   | |_^
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
+   = note: fields of packed structs are not properly aligned, and creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
+   = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
+   = note: this error originates in the macro `$crate::__pin_project_constant` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: reference to packed field is unaligned
+  --> tests/ui/pin_project/packed.rs:13:1
+   |
+13 | / pin_project! { //~ ERROR reference to packed field is unaligned
+14 | |     #[repr(packed(2))]
+15 | |     struct PackedN {
+16 | |         #[pin]
+17 | |         field: u32,
+18 | |     }
+19 | | }
+   | |_^
+   |
+note: the lint level is defined here
+  --> tests/ui/pin_project/packed.rs:13:1
+   |
+13 | / pin_project! { //~ ERROR reference to packed field is unaligned
+14 | |     #[repr(packed(2))]
+15 | |     struct PackedN {
+16 | |         #[pin]
+17 | |         field: u32,
+18 | |     }
+19 | | }
+   | |_^
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
+   = note: fields of packed structs are not properly aligned, and creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
+   = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
+   = note: this error originates in the macro `$crate::__pin_project_constant` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.rs
new file mode 100644
index 0000000000..984cc2a219
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.rs
@@ -0,0 +1,12 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Foo {
+        #[pin]
+        inner: u8,
+    }
+}
+
+impl Unpin for __Origin {} //~ ERROR E0412,E0321
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.stderr
new file mode 100644
index 0000000000..4eb6eff96f
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/unpin_sneaky.stderr
@@ -0,0 +1,11 @@
+error[E0412]: cannot find type `__Origin` in this scope
+  --> tests/ui/pin_project/unpin_sneaky.rs:10:16
+   |
+10 | impl Unpin for __Origin {} //~ ERROR E0412,E0321
+   |                ^^^^^^^^ not found in this scope
+
+error[E0321]: cross-crate traits with a default impl, like `Unpin`, can only be implemented for a struct/enum type, not `[type error]`
+  --> tests/ui/pin_project/unpin_sneaky.rs:10:1
+   |
+10 | impl Unpin for __Origin {} //~ ERROR E0412,E0321
+   | ^^^^^^^^^^^^^^^^^^^^^^^ can't implement cross-crate trait with a default impl for non-struct/enum type
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.rs b/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.rs
new file mode 100644
index 0000000000..2f80836275
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.rs
@@ -0,0 +1,27 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    struct Struct1 {} //~ ERROR no rules expected the token `}`
+}
+
+pin_project! {
+    struct Struct2(); //~ ERROR no rules expected the token `(`
+}
+
+pin_project! {
+    struct Struct3; //~ ERROR no rules expected the token `;`
+}
+
+pin_project! {
+    enum Enum { //~ ERROR no rules expected the token `enum`
+        A(u8)
+    }
+}
+
+pin_project! {
+    union Union { //~ ERROR no rules expected the token `union`
+        x: u8,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.stderr b/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.stderr
new file mode 100644
index 0000000000..a7d215a43e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pin_project/unsupported.stderr
@@ -0,0 +1,79 @@
+error: no rules expected the token `}`
+ --> tests/ui/pin_project/unsupported.rs:3:1
+  |
+3 | / pin_project! {
+4 | |     struct Struct1 {} //~ ERROR no rules expected the token `}`
+5 | | }
+  | |_^ no rules expected this token in macro call
+  |
+  = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `}`
+ --> tests/ui/pin_project/unsupported.rs:3:1
+  |
+3 | / pin_project! {
+4 | |     struct Struct1 {} //~ ERROR no rules expected the token `}`
+5 | | }
+  | |_^ no rules expected this token in macro call
+  |
+  = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `(`
+ --> tests/ui/pin_project/unsupported.rs:8:19
+  |
+8 |     struct Struct2(); //~ ERROR no rules expected the token `(`
+  |                   ^ no rules expected this token in macro call
+
+error: no rules expected the token `;`
+  --> tests/ui/pin_project/unsupported.rs:12:19
+   |
+12 |     struct Struct3; //~ ERROR no rules expected the token `;`
+   |                   ^ no rules expected this token in macro call
+
+error: no rules expected the token `enum`
+  --> tests/ui/pin_project/unsupported.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     enum Enum { //~ ERROR no rules expected the token `enum`
+17 | |         A(u8)
+18 | |     }
+19 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `enum`
+  --> tests/ui/pin_project/unsupported.rs:15:1
+   |
+15 | / pin_project! {
+16 | |     enum Enum { //~ ERROR no rules expected the token `enum`
+17 | |         A(u8)
+18 | |     }
+19 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `union`
+  --> tests/ui/pin_project/unsupported.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     union Union { //~ ERROR no rules expected the token `union`
+23 | |         x: u8,
+24 | |     }
+25 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: no rules expected the token `union`
+  --> tests/ui/pin_project/unsupported.rs:21:1
+   |
+21 | / pin_project! {
+22 | |     union Union { //~ ERROR no rules expected the token `union`
+23 | |         x: u8,
+24 | |     }
+25 | | }
+   | |_^ no rules expected this token in macro call
+   |
+   = note: this error originates in the macro `$crate::__pin_project_expand` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.rs b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.rs
new file mode 100644
index 0000000000..609b3bebad
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.rs
@@ -0,0 +1,17 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    pub struct S {
+        #[pin]
+        field: u8,
+    }
+    impl PinnedDrop for S {
+        fn drop(this: Pin<&mut Self>) {
+            __drop_inner(this);
+        }
+    }
+}
+
+fn main() {
+    let _x = S { field: 0 };
+}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.stderr b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.stderr
new file mode 100644
index 0000000000..597f67c84f
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.stderr
@@ -0,0 +1,22 @@
+error[E0061]: this function takes 0 arguments but 1 argument was supplied
+  --> tests/ui/pinned_drop/call-drop-inner.rs:10:13
+   |
+10 |             __drop_inner(this);
+   |             ^^^^^^^^^^^^ ---- argument unexpected
+   |
+note: function defined here
+  --> tests/ui/pinned_drop/call-drop-inner.rs:3:1
+   |
+3  | / pin_project! {
+4  | |     pub struct S {
+5  | |         #[pin]
+6  | |         field: u8,
+...  |
+12 | |     }
+13 | | }
+   | |_^
+   = note: this error originates in the macro `$crate::__pin_project_make_drop_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: remove the extra argument
+   |
+10 |             __drop_inner();
+   |             ~~~~~~~~~~~~~~
diff --git a/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.rs b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.rs
new file mode 100644
index 0000000000..68b01b265e
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.rs
@@ -0,0 +1,26 @@
+use pin_project_lite::pin_project;
+
+// In `Drop` impl, the implementor must specify the same requirement as type definition.
+
+struct DropImpl<T> {
+    f: T,
+}
+
+impl<T: Unpin> Drop for DropImpl<T> {
+    //~^ ERROR E0367
+    fn drop(&mut self) {}
+}
+
+pin_project! {
+    //~^ ERROR E0367
+    struct PinnedDropImpl<T> {
+        #[pin]
+        f: T,
+    }
+
+    impl<T: Unpin> PinnedDrop for PinnedDropImpl<T> {
+        fn drop(_this: Pin<&mut Self>) {}
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.stderr b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.stderr
new file mode 100644
index 0000000000..d70009c97a
--- /dev/null
+++ b/third_party/rust/pin-project-lite/tests/ui/pinned_drop/conditional-drop-impl.stderr
@@ -0,0 +1,38 @@
+error[E0367]: `Drop` impl requires `T: Unpin` but the struct it is implemented for does not
+ --> tests/ui/pinned_drop/conditional-drop-impl.rs:9:9
+  |
+9 | impl<T: Unpin> Drop for DropImpl<T> {
+  |         ^^^^^
+  |
+note: the implementor must specify the same requirement
+ --> tests/ui/pinned_drop/conditional-drop-impl.rs:5:1
+  |
+5 | / struct DropImpl<T> {
+6 | |     f: T,
+7 | | }
+  | |_^
+
+error[E0367]: `Drop` impl requires `T: Unpin` but the struct it is implemented for does not
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:14:1
+   |
+14 | / pin_project! {
+15 | |     //~^ ERROR E0367
+16 | |     struct PinnedDropImpl<T> {
+17 | |         #[pin]
+...  |
+23 | |     }
+24 | | }
+   | |_^
+   |
+note: the implementor must specify the same requirement
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:14:1
+   |
+14 | / pin_project! {
+15 | |     //~^ ERROR E0367
+16 | |     struct PinnedDropImpl<T> {
+17 | |         #[pin]
+...  |
+23 | |     }
+24 | | }
+   | |_^
+   = note: this error originates in the macro `$crate::__pin_project_make_drop_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/.cargo-checksum.json b/third_party/rust/pin-project/.cargo-checksum.json
new file mode 100644
index 0000000000..6c1292f80c
--- /dev/null
+++ b/third_party/rust/pin-project/.cargo-checksum.json
@@ -0,0 +1 @@
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t-unpin.rs":"a22831379eb1f2d597d5f8088130f7c91add5ec69bade962d555d1b49145f56a","tests/ui/unsafe_unpin/conflict-unpin.stderr":"d5bd3f04d069d30491244e03e8520c05c71ec7bc3b9e2fdec8dc1c8e5a3d8d8f","tests/ui/unstable-features/README.md":"f9dcf95e9c68fe15345f493a3fb4f54726d36c76d1a5a1e2c9dfa25540d4b642","tests/ui/unstable-features/marker_trait_attr-feature-gate.rs":"35596063ddbc8a289182c3a18d98d595583e6a0b2b3324d3eec4f416de06ea4b","tests/ui/unstable-features/marker_trait_attr-feature-gate.stderr":"9e22be3282c29e976ae39f48b6bd866ef6fb45694867800991d445dc1cecb8ca","tests/ui/unstable-features/marker_trait_attr.rs":"f2a5275a5b80249d2a0e7a4e9e7d3f573ffd5f2a183dfced314e91a7d7945007","tests/ui/unstable-features/marker_trait_attr.stderr":"fbfd1b4f4a4daed395da86d31c5f305eaa026d111df2cd2a62fa2ed66ebf7b67","tests/ui/unstable-features/negative_impls.rs":"b913f3d818cc4d91efe4b82dd08b72acff89b97d7e56a33d8106c93f1de6a81d","tests/ui/unstable-features/negative_impls.stderr":"8af35392f3db6ed3e326f03ea9e9050138b59ea559ab92760a3c12db208c2805","tests/ui/unstable-features/overlapping_marker_traits-feature-gate.rs":"dc6b854cc60ea03344f8ca3fa518a2bdc0b9aa69f2368162f4b6ad24d31bc4f0","tests/ui/unstable-features/overlapping_marker_traits-feature-gate.stderr":"9d4e7b12b19fafb2eb0b924c924ce563d99f6b787ed7663b4a2e66e6e9d3e1b6","tests/ui/unstable-features/overlapping_marker_traits.rs":"8af0d8a5afe9dcaa02fa67b394d376f9933cc99361d68f64185769326700bf7c","tests/ui/unstable-features/overlapping_marker_traits.stderr":"ed49c06dcdc05160b9cf8bdc450b27d3bb981c96e271cda1fa977d205ef5b0c8","tests/ui/unstable-features/trivial_bounds-feature-gate.rs":"658aab9de2e52a54b9e4731faae6a87172b1b4b78f3853c9fd4b565066b74e64","tests/ui/unstable-features/trivial_bounds-feature-gate.stderr":"f95c11b531c1d2bc9d7a7d64d70bc62217608498ed468ed6cc6acd03d70205ca","tests/ui/unstable-features/trivial_bounds.rs":"b12e91f4f24b841bb83b4831849795999a2095b25ab62c8966948ed03da3d327","tests/ui/unstable-features/trivial_bounds.stderr":"96d4f84e3a14064a495a57e32fe31b1c3fc819253a95c83b2a2e5ae48bd4fdc3","tests/unsafe_unpin.rs":"5ec1a97b7a54fe1cdc72f8e2c71ea8101caa0426d286532946c324be4eabead8"},"package":"ad29a609b6bcd67fee905812e544992d216af9d755757c05ed2d0e15a74c6ecc"}
\ No newline at end of file
diff --git a/third_party/rust/pin-project/CHANGELOG.md b/third_party/rust/pin-project/CHANGELOG.md
new file mode 100644
index 0000000000..76e245fa05
--- /dev/null
+++ b/third_party/rust/pin-project/CHANGELOG.md
@@ -0,0 +1,758 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+This project adheres to [Semantic Versioning](https://semver.org).
+
+<!--
+Note: In this file, do not use the hard wrap in the middle of a sentence for compatibility with GitHub comment style markdown rendering.
+-->
+
+## [Unreleased]
+
+## [1.0.12] - 2022-08-15
+
+- Suppress `unused_tuple_struct_fields` lint in generated code.
+
+## [1.0.11] - 2022-07-02
+
+- [Suppress `dead_code` lint in generated code.](https://github.com/taiki-e/pin-project/pull/346)
+
+## [1.0.10] - 2021-12-31
+
+- Revert the increase of the minimal version of `syn` that was done in 1.0.9.
+
+## [1.0.9] - 2021-12-26
+
+- [Prevent abuse of private module.](https://github.com/taiki-e/pin-project/pull/336)
+
+- Update minimal version of `syn` to 1.0.84.
+
+## [1.0.8] - 2021-07-21
+
+- [Suppress `clippy::use_self` and `clippy::type_repetition_in_bounds` lints in generated code.](https://github.com/taiki-e/pin-project/pull/331)
+
+## [1.0.7] - 2021-04-16
+
+- [Fix compile error when using `self::` as prefix of path inside `#[pinned_drop]` impl.](https://github.com/taiki-e/pin-project/pull/326)
+
+## [1.0.6] - 2021-03-25
+
+- [Suppress `clippy::semicolon_if_nothing_returned` lint in generated code.](https://github.com/taiki-e/pin-project/pull/318)
+
+## [1.0.5] - 2021-02-03
+
+- [Suppress `deprecated` lint in generated code.](https://github.com/taiki-e/pin-project/pull/313)
+
+## [1.0.4] - 2021-01-09
+
+- [Suppress `clippy::ref_option_ref` lint in generated code.](https://github.com/taiki-e/pin-project/pull/308)
+
+## [1.0.3] - 2021-01-05
+
+- Exclude unneeded files from crates.io.
+
+## [1.0.2] - 2020-11-18
+
+- [Suppress `clippy::unknown_clippy_lints` lint in generated code.](https://github.com/taiki-e/pin-project/pull/303)
+
+## [1.0.1] - 2020-10-15
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/commit/ddcd88079ba2d82857c365f2a3543ad146ade54c).
+
+- [Fix warnings when `#[pin_project]` attribute used within `macro_rules!` macros.](https://github.com/taiki-e/pin-project/pull/298)
+
+## [1.0.0] - 2020-10-13
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/commit/ddcd88079ba2d82857c365f2a3543ad146ade54c).
+
+- [Remove deprecated `#[project]`, `#[project_ref]`, and `#[project_replace]` attributes.](https://github.com/taiki-e/pin-project/pull/265)
+
+  Name the projected type by passing an argument with the same name as the method to the `#[pin_project]` attribute instead:
+
+  ```diff
+  - #[pin_project]
+  + #[pin_project(project = EnumProj)]
+    enum Enum<T> {
+        Variant(#[pin] T),
+    }
+
+  - #[project]
+    fn func<T>(x: Pin<&mut Enum<T>>) {
+  -     #[project]
+        match x.project() {
+  -         Enum::Variant(_) => { /* ... */ }
+  +         EnumProj::Variant(_) => { /* ... */ }
+        }
+    }
+  ```
+
+- [Remove deprecated `Replace` argument from `#[pin_project]` attribute.](https://github.com/taiki-e/pin-project/pull/266) Use `project_replace` argument instead.
+
+- [Optimize code generation when used on enums.](https://github.com/taiki-e/pin-project/pull/270)
+
+- [Raise the minimum supported Rust version of this crate from Rust 1.34 to Rust 1.37.](https://github.com/taiki-e/pin-project/pull/292)
+
+- Suppress `explicit_outlives_requirements`, `box_pointers`, `clippy::large_enum_variant`, `clippy::pattern_type_mismatch`, `clippy::implicit_return`, and `clippy::redundant_pub_crate` lints in generated code. ([#276](https://github.com/taiki-e/pin-project/pull/276), [#277](https://github.com/taiki-e/pin-project/pull/277), [#284](https://github.com/taiki-e/pin-project/pull/284))
+
+- Diagnostic improvements.
+
+Changes since the 1.0.0-alpha.1 release:
+
+- [Fix drop order of pinned fields in `project_replace`.](https://github.com/taiki-e/pin-project/pull/287)
+
+- Update minimal version of `syn` to 1.0.44.
+
+## [1.0.0-alpha.1] - 2020-09-22
+
+- [Remove deprecated `#[project]`, `#[project_ref]`, and `#[project_replace]` attributes.](https://github.com/taiki-e/pin-project/pull/265)
+
+  Name the projected type by passing an argument with the same name as the method to the `#[pin_project]` attribute instead:
+
+  ```diff
+  - #[pin_project]
+  + #[pin_project(project = EnumProj)]
+    enum Enum<T> {
+        Variant(#[pin] T),
+    }
+
+  - #[project]
+    fn func<T>(x: Pin<&mut Enum<T>>) {
+  -     #[project]
+        match x.project() {
+  -         Enum::Variant(_) => { /* ... */ }
+  +         EnumProj::Variant(_) => { /* ... */ }
+        }
+    }
+  ```
+
+- [Remove deprecated `Replace` argument from `#[pin_project]` attribute.](https://github.com/taiki-e/pin-project/pull/266) Use `project_replace` argument instead.
+
+- [Optimize code generation when used on enums.](https://github.com/taiki-e/pin-project/pull/270)
+
+- Suppress `explicit_outlives_requirements`, `box_pointers`, `clippy::large_enum_variant`, `clippy::pattern_type_mismatch`, and `clippy::implicit_return` lints in generated code. ([#276](https://github.com/taiki-e/pin-project/pull/276), [#277](https://github.com/taiki-e/pin-project/pull/277))
+
+- Diagnostic improvements.
+
+See also [tracking issue for 1.0 release](https://github.com/taiki-e/pin-project/issues/264).
+
+## [0.4.30] - 2022-07-02
+
+- [Suppress `dead_code` lint in generated code.](https://github.com/taiki-e/pin-project/pull/347)
+
+## [0.4.29] - 2021-12-26
+
+- [Fix compile error with `syn` 1.0.84 and later.](https://github.com/taiki-e/pin-project/pull/335)
+
+## [0.4.28] - 2021-03-28
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix `unused_must_use` warning on unused borrows, which will be added to rustc in the future.](https://github.com/taiki-e/pin-project/pull/322) See [#322](https://github.com/taiki-e/pin-project/pull/322) for more details.
+
+  (Note: 1.0 does not have this problem.)
+
+## [0.4.27] - 2020-10-11
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- Update minimal version of `syn` to 1.0.44.
+
+## [0.4.26] - 2020-10-04
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix drop order of pinned fields in `project_replace`.](https://github.com/taiki-e/pin-project/pull/287)
+
+## [0.4.25] - 2020-10-01
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Suppress `drop_bounds` lint, which will be added to rustc in the future.](https://github.com/taiki-e/pin-project/pull/273) See [#272](https://github.com/taiki-e/pin-project/issues/272) for more details.
+
+  (Note: 1.0.0-alpha.1 already contains this change.)
+
+## [0.4.24] - 2020-09-26
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix compatibility of generated code with `forbid(future_incompatible)`.](https://github.com/taiki-e/pin-project/pull/282)
+
+  Note: This does not guarantee compatibility with `forbid(future_incompatible)` in the future.
+  If rustc adds a new lint, we may not be able to keep this.
+
+## [0.4.23] - 2020-07-27
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix compile error with `?Sized` type parameters.](https://github.com/taiki-e/pin-project/pull/263)
+
+## [0.4.22] - 2020-06-14
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- Documentation improvements.
+
+## [0.4.21] - 2020-06-13
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Deprecated `#[project]`, `#[project_ref]`, and `#[project_replace]` attributes due to some unfixable limitations.](https://github.com/taiki-e/pin-project/pull/244)
+
+  Consider naming the projected type by passing an argument with the same name as the method to the `#[pin_project]` attribute instead.
+
+  ```rust
+  #[pin_project(project = EnumProj)]
+  enum Enum<T> {
+      Variant(#[pin] T),
+  }
+
+  fn func<T>(x: Pin<&mut Enum<T>>) {
+      match x.project() {
+          EnumProj::Variant(y) => {
+              let _: Pin<&mut T> = y;
+          }
+      }
+  }
+  ```
+
+  See [#225](https://github.com/taiki-e/pin-project/pull/225) for more details.
+
+- [Support `Self` in fields and generics in type definitions.](https://github.com/taiki-e/pin-project/pull/245)
+
+- [Fix errors involving *"`self` value is a keyword only available in methods with `self` parameter"* in apparently correct code.](https://github.com/taiki-e/pin-project/pull/250)
+
+- Diagnostic improvements.
+
+## [0.4.20] - 2020-06-07
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [You can now use `project_replace` argument without Replace argument.](https://github.com/taiki-e/pin-project/pull/243)
+  This used to require you to specify both.
+
+  ```diff
+  - #[pin_project(Replace, project_replace = EnumProjOwn)]
+  + #[pin_project(project_replace = EnumProjOwn)]
+    enum Enum<T> {
+        Variant(#[pin] T)
+    }
+  ```
+
+- [Make `project_replace` argument an alias for `Replace` argument so that it can be used without a value.](https://github.com/taiki-e/pin-project/pull/243)
+
+  ```rust
+  #[pin_project(project_replace)]
+  enum Enum<T> {
+      Variant(#[pin] T)
+  }
+  ```
+
+  *The `Replace` argument will be deprecated in the future.*
+
+- [Suppress `unreachable_pub` lint in generated code.](https://github.com/taiki-e/pin-project/pull/240)
+
+## [0.4.19] - 2020-06-04
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Suppress `unused_results` lint in generated code.](https://github.com/taiki-e/pin-project/pull/239)
+
+## [0.4.18] - 2020-06-04
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Support `Self` in more syntax positions inside `#[pinned_drop]` impl.](https://github.com/taiki-e/pin-project/pull/230)
+
+- [Suppress `clippy::type_repetition_in_bounds` and `clippy::used_underscore_binding` lints in generated code.](https://github.com/taiki-e/pin-project/pull/233)
+
+- Documentation improvements.
+
+- Diagnostic improvements.
+
+## [0.4.17] - 2020-05-18
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Support naming the projection types.](https://github.com/taiki-e/pin-project/pull/202)
+
+  By passing an argument with the same name as the method to the attribute, you can name the projection type returned from the method:
+
+  ```rust
+  #[pin_project(project = EnumProj)]
+  enum Enum<T> {
+      Variant(#[pin] T),
+  }
+
+  fn func<T>(x: Pin<&mut Enum<T>>) {
+      match x.project() {
+          EnumProj::Variant(y) => {
+              let _: Pin<&mut T> = y;
+          }
+      }
+  }
+  ```
+
+## [0.4.16] - 2020-05-11
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix an issue that users can call internal function generated by `#[pinned_drop]`.](https://github.com/taiki-e/pin-project/pull/223)
+
+## [0.4.15] - 2020-05-10
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [`#[project]` attribute can now handle all `project*` attributes in that scope with one wrapper attribute.](https://github.com/taiki-e/pin-project/pull/220)
+
+## [0.4.14] - 2020-05-09
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Add `!Unpin` option to `#[pin_project]` attribute for guarantee the type is `!Unpin`.](https://github.com/taiki-e/pin-project/pull/219)
+
+  ```rust
+  #[pin_project(!Unpin)]
+  struct Struct<T, U> {
+      field: T,
+  }
+  ```
+
+  This is equivalent to use `#[pin]` attribute for `PhantomPinned` field.
+
+  ```rust
+  #[pin_project]
+  struct Struct<T, U> {
+      field: T,
+      #[pin] // Note that using `PhantomPinned` without `#[pin]` attribute has no effect.
+      _pin: PhantomPinned,
+  }
+  ```
+
+  *[Note: This raises the minimum supported Rust version of this crate from Rust 1.33 to Rust 1.34.](https://github.com/taiki-e/pin-project/pull/219#pullrequestreview-408644187)*
+
+- [Fix an issue where duplicate `#[project]` attributes were ignored.](https://github.com/taiki-e/pin-project/pull/218)
+
+- [Suppress `single_use_lifetimes` lint in generated code.](https://github.com/taiki-e/pin-project/pull/217)
+
+- [Support overlapping lifetime names in HRTB.](https://github.com/taiki-e/pin-project/pull/217)
+
+- [Hide generated items from --document-private-items.](https://github.com/taiki-e/pin-project/pull/211) See [#211](https://github.com/taiki-e/pin-project/pull/211) for details.
+
+- Documentation improvements.
+
+## [0.4.13] - 2020-05-07
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix a regression in 0.4.11.](https://github.com/taiki-e/pin-project/pull/207)
+
+  Changes from [0.4.10](https://github.com/taiki-e/pin-project/releases/tag/v0.4.10) and [0.4.12](https://github.com/taiki-e/pin-project/releases/tag/v0.4.12):
+
+  - [Fix an issue that `#[project]` on non-statement expression does not work without unstable features.](https://github.com/taiki-e/pin-project/pull/197)
+
+  - [Support overwriting the name of core crate.](https://github.com/taiki-e/pin-project/pull/199)
+
+  - [Suppress `clippy::needless_pass_by_value` lint in generated code of `#[pinned_drop]`.](https://github.com/taiki-e/pin-project/pull/200)
+
+  - Documentation improvements.
+
+  - Diagnostic improvements.
+
+## [0.4.12] - 2020-05-07
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- A release to avoid [a regression in 0.4.11](https://github.com/taiki-e/pin-project/issues/206). No code changes from [0.4.10](https://github.com/taiki-e/pin-project/releases/tag/v0.4.10).
+
+## [0.4.11] - 2020-05-07
+
+**Note:** This release has been yanked. See [#206](https://github.com/taiki-e/pin-project/issues/206) for details.
+
+- [Fix an issue that `#[project]` on non-statement expression does not work without unstable features.](https://github.com/taiki-e/pin-project/pull/197)
+
+- [Support overwriting the name of core crate.](https://github.com/taiki-e/pin-project/pull/199)
+
+- [Suppress `clippy::needless_pass_by_value` lint in generated code of `#[pinned_drop]`.](https://github.com/taiki-e/pin-project/pull/200)
+
+- Documentation improvements.
+
+- Diagnostic improvements.
+
+## [0.4.10] - 2020-05-04
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Add `project_replace` method and `#[project_replace]` attribute.](https://github.com/taiki-e/pin-project/pull/194)
+  `project_replace` method is optional and can be enabled by passing the `Replace` argument to `#[pin_project]` attribute.
+  See [the documentation](https://docs.rs/pin-project/0.4/pin_project/attr.pin_project.html#project_replace) for more details.
+
+- [Support `Self` and `self` in more syntax positions inside `#[pinned_drop]` impl.](https://github.com/taiki-e/pin-project/pull/190)
+
+- [Hide all generated items except for projected types from calling code.](https://github.com/taiki-e/pin-project/pull/192) See [#192](https://github.com/taiki-e/pin-project/pull/192) for details.
+
+## [0.4.9] - 2020-04-14
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix lifetime inference error when associated types are used in fields.](https://github.com/taiki-e/pin-project/pull/188)
+
+- [Fix compile error with tuple structs with `where` clauses.](https://github.com/taiki-e/pin-project/pull/186)
+
+- [`#[project]` attribute can now be used for `if let` expressions.](https://github.com/taiki-e/pin-project/pull/181)
+
+## [0.4.8] - 2020-01-27
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Ensure that users cannot implement `PinnedDrop` without proper attribute argument.](https://github.com/taiki-e/pin-project/pull/180)
+
+- [Fix use of `Self` in expression position inside `#[pinned_drop]` impl.](https://github.com/taiki-e/pin-project/pull/177)
+
+## [0.4.7] - 2020-01-20
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix support for lifetime bounds.](https://github.com/taiki-e/pin-project/pull/176)
+
+## [0.4.6] - 2019-11-20
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix compile error when there is `Self` in the where clause.](https://github.com/taiki-e/pin-project/pull/169)
+
+## [0.4.5] - 2019-10-21
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix compile error with `dyn` types.](https://github.com/taiki-e/pin-project/pull/158)
+
+## [0.4.4] - 2019-10-17
+
+**Note:** This release has been yanked because it [failed to compile with syn 1.0.84 and later](https://github.com/taiki-e/pin-project/pull/335).
+
+- [Fix an issue where `PinnedDrop` implementations can call unsafe code without an unsafe block.](https://github.com/taiki-e/pin-project/pull/149)
+
+## [0.4.3] - 2019-10-15
+
+**Note:** This release has been yanked. See [#148](https://github.com/taiki-e/pin-project/pull/148) for details.
+
+- [`#[pin_project]` can now interoperate with `#[cfg_attr()]`.](https://github.com/taiki-e/pin-project/pull/135)
+
+- [`#[pin_project]` can now interoperate with `#[cfg()]` on tuple structs and tuple variants.](https://github.com/taiki-e/pin-project/pull/135)
+
+- [Fix support for DSTs(Dynamically Sized Types) on `#[pin_project(UnsafeUnpin)]`](https://github.com/taiki-e/pin-project/pull/120)
+
+- Diagnostic improvements.
+
+## [0.4.2] - 2019-09-29
+
+**Note:** This release has been yanked. See [#148](https://github.com/taiki-e/pin-project/pull/148) for details.
+
+- [Fix support for DSTs(Dynamically Sized Types).](https://github.com/taiki-e/pin-project/pull/113)
+
+## [0.4.1] - 2019-09-26
+
+**Note:** This release has been yanked. See [#148](https://github.com/taiki-e/pin-project/pull/148) for details.
+
+- [Fix an issue that caused an error when using `#[pin_project]` on a type that has `#[pin]` + `!Unpin` field with no generics or lifetime.](https://github.com/taiki-e/pin-project/pull/111)
+
+## [0.4.0] - 2019-09-25
+
+**Note:** This release has been yanked. See [#148](https://github.com/taiki-e/pin-project/pull/148) for details.
+
+- [**Pin projection has become a safe operation.**](https://github.com/taiki-e/pin-project/pull/18) In the absence of other unsafe code that you write, it is impossible to cause undefined behavior.
+
+- `#[unsafe_project]` attribute has been replaced with `#[pin_project]` attribute. ([#18](https://github.com/taiki-e/pin-project/pull/18), [#33](https://github.com/taiki-e/pin-project/pull/33))
+
+- [The `Unpin` argument has been removed - an `Unpin` impl is now generated by default.](https://github.com/taiki-e/pin-project/pull/18)
+
+- Drop impls must be specified with `#[pinned_drop]` instead of via a normal `Drop` impl. ([#18](https://github.com/taiki-e/pin-project/pull/18), [#33](https://github.com/taiki-e/pin-project/pull/33), [#86](https://github.com/taiki-e/pin-project/pull/86))
+
+- [`Unpin` impls must be specified with an impl of `UnsafeUnpin`, instead of implementing the normal `Unpin` trait.](https://github.com/taiki-e/pin-project/pull/18)
+
+- [`#[pin_project]` attribute now determines the visibility of the projection type/method is based on the original type.](https://github.com/taiki-e/pin-project/pull/96)
+
+- [`#[pin_project]` can now be used for public type with private field types.](https://github.com/taiki-e/pin-project/pull/53)
+
+- [`#[pin_project]` can now interoperate with `#[cfg()]`.](https://github.com/taiki-e/pin-project/pull/77)
+
+- [Add `project_ref` method to `#[pin_project]` types.](https://github.com/taiki-e/pin-project/pull/93)
+
+- [Add `#[project_ref]` attribute.](https://github.com/taiki-e/pin-project/pull/93)
+
+- [Remove "project_attr" feature and always enable `#[project]` attribute.](https://github.com/taiki-e/pin-project/pull/94)
+
+- [`#[project]` attribute can now be used for `impl` blocks.](https://github.com/taiki-e/pin-project/pull/46)
+
+- [`#[project]` attribute can now be used for `use` statements.](https://github.com/taiki-e/pin-project/pull/85)
+
+- [`#[project]` attribute now supports `match` expressions at the position of the initializer expression of `let` expressions.](https://github.com/taiki-e/pin-project/pull/51)
+
+Changes since the 0.4.0-beta.1 release:
+
+- [Fix an issue that caused an error when using `#[pin_project(UnsafeUnpin)]` and not providing a manual `UnsafeUnpin` implementation on a type with no generics or lifetime.](https://github.com/taiki-e/pin-project/pull/107)
+
+## [0.4.0-beta.1] - 2019-09-21
+
+- [Change the argument type of project method back to `self: Pin<&mut Self>`.](https://github.com/taiki-e/pin-project/pull/90)
+
+- [Remove "project_attr" feature and always enable `#[project]` attribute.](https://github.com/taiki-e/pin-project/pull/94)
+
+- [Remove "renamed" feature.](https://github.com/taiki-e/pin-project/pull/100)
+
+- [`#[project]` attribute can now be used for `use` statements.](https://github.com/taiki-e/pin-project/pull/85)
+
+- [Add `project_ref` method and `#[project_ref]` attribute.](https://github.com/taiki-e/pin-project/pull/93)
+
+- [`#[pin_project]` attribute now determines the visibility of the projection type/method is based on the original type.](https://github.com/taiki-e/pin-project/pull/96)
+
+## [0.4.0-alpha.11] - 2019-09-11
+
+- [Change #[pinned_drop] to trait implementation.](https://github.com/taiki-e/pin-project/pull/86)
+
+  ```rust
+  #[pinned_drop]
+  impl<T> PinnedDrop for Foo<'_, T> {
+      fn drop(mut self: Pin<&mut Self>) {
+          **self.project().was_dropped = true;
+      }
+  }
+  ```
+
+- Add some examples and generated code.
+
+- Diagnostic improvements.
+
+## [0.4.0-alpha.10] - 2019-09-07
+
+- [`#[pin_project]` can now interoperate with `#[cfg()]`.](https://github.com/taiki-e/pin-project/pull/77)
+
+- Documentation improvements.
+
+## [0.4.0-alpha.9] - 2019-09-05
+
+- [Add `project_into` method to `#[pin_project]` types](https://github.com/taiki-e/pin-project/pull/69). This can be useful when returning a pin projection from a method.
+
+  ```rust
+  fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut T> {
+      self.project_into().pinned
+  }
+  ```
+
+- [Prevent `UnpinStruct` from appearing in the document by default.](https://github.com/taiki-e/pin-project/pull/71) See [#71](https://github.com/taiki-e/pin-project/pull/71) for more details.
+
+## [0.4.0-alpha.8] - 2019-09-03
+
+- [Improve document of generated code.](https://github.com/taiki-e/pin-project/pull/62). Also added an option to control the document of generated code. See [#62](https://github.com/taiki-e/pin-project/pull/62) for more details.
+
+- [Diagnostic improvements.](https://github.com/taiki-e/pin-project/pull/61)
+
+## [0.4.0-alpha.7] - 2019-09-02
+
+- [Suppress `dead_code` lint in generated types.](https://github.com/taiki-e/pin-project/pull/57)
+
+## [0.4.0-alpha.6] - 2019-09-01
+
+- [Allow using `#[pin_project]` type with private field types](https://github.com/taiki-e/pin-project/pull/53)
+
+## [0.4.0-alpha.5] - 2019-08-24
+
+- [`#[project]` attribute now supports `match` expressions at the position of the initializer expression of `let` expressions.](https://github.com/taiki-e/pin-project/pull/51)
+
+## [0.4.0-alpha.4] - 2019-08-23
+
+- Suppress `clippy::drop_bounds` lint in generated code.
+
+## [0.4.0-alpha.3] - 2019-08-23
+
+- [Change `project` method generated by `#[pin_project]` attribute to take an `&mut Pin<&mut Self>` argument.](https://github.com/taiki-e/pin-project/pull/47)
+
+- [`#[project]` attribute can now be used for impl blocks.](https://github.com/taiki-e/pin-project/pull/46)
+
+- [`#[pin_project]` attribute can now detect that the type used does not have its own drop implementation without actually implementing drop.](https://github.com/taiki-e/pin-project/pull/48) This removed some restrictions.
+
+## [0.4.0-alpha.2] - 2019-08-13
+
+- Update `proc-macro2`, `syn`, and `quote` to 1.0.
+
+## [0.4.0-alpha.1] - 2019-08-11
+
+- **Pin projection has become a safe operation.**
+
+- `#[unsafe_project]` has been replaced with `#[pin_project]`.
+
+- The `Unpin` argument has been removed - an `Unpin` impl is now generated by default.
+
+- Drop impls must be specified with `#[pinned_drop]` instead of via a normal `Drop` impl.
+
+- `Unpin` impls must be specified with an impl of `UnsafeUnpin`, instead of implementing the normal `Unpin` trait.
+
+- Make `#[project]` attribute disabled by default.
+
+See also [tracking issue for 0.4 release](https://github.com/taiki-e/pin-project/issues/21).
+
+## [0.3.5] - 2019-08-14
+
+- Update `proc-macro2`, `syn`, and `quote` to 1.0.
+
+## [0.3.4] - 2019-07-21
+
+- Diagnostic improvements.
+
+## [0.3.3] - 2019-07-15
+
+**Note:** This release has been yanked. See [#16](https://github.com/taiki-e/pin-project/issues/16) for details.
+
+- Diagnostic improvements.
+
+## [0.3.2] - 2019-03-30
+
+- Avoid suffixes on tuple index.
+
+## [0.3.1] - 2019-03-02
+
+- Documentation improvements.
+
+- Update minimum `syn` version to 0.15.22.
+
+## [0.3.0] - 2019-02-20
+
+- Remove `unsafe_fields` attribute.
+
+- Remove `unsafe_variants` attribute.
+
+## [0.2.2] - 2019-02-20
+
+- Fix a bug that generates incorrect code for the some structures with trait bounds on type generics.
+
+## [0.2.1] - 2019-02-20
+
+- Fix a bug that generates incorrect code for the structures with where clause and associated type fields.
+
+## [0.2.0] - 2019-02-11
+
+- Make `unsafe_fields` optional.
+
+- Documentation improvements.
+
+## [0.1.8] - 2019-02-02
+
+- Add the feature to create projected enums to `unsafe_project`.
+
+- Add `project` attribute to support pattern matching.
+
+## [0.1.7] - 2019-01-19
+
+- Fix documentation.
+
+## [0.1.6] - 2019-01-19
+
+- `unsafe_fields` can now opt-out.
+
+- Add `unsafe_variants` attribute. This attribute is available if pin-project is built with the "unsafe_variants" feature.
+
+## [0.1.5] - 2019-01-17
+
+- Add support for tuple struct to `unsafe_project`.
+
+## [0.1.4] - 2019-01-12
+
+- Add options for automatically implementing `Unpin` to both `unsafe_project` and `unsafe_fields`.
+
+## [0.1.3] - 2019-01-11
+
+- Fix dependencies.
+
+- Add `unsafe_fields` attribute.
+
+## [0.1.2] - 2019-01-09
+
+- Documentation improvements.
+
+## [0.1.1] - 2019-01-08
+
+- Rename from `unsafe_pin_project` to `unsafe_project`.
+
+## [0.1.0] - 2019-01-08
+
+**Note:** This release has been yanked.
+
+Initial release
+
+[Unreleased]: https://github.com/taiki-e/pin-project/compare/v1.0.12...HEAD
+[1.0.12]: https://github.com/taiki-e/pin-project/compare/v1.0.11...v1.0.12
+[1.0.11]: https://github.com/taiki-e/pin-project/compare/v1.0.10...v1.0.11
+[1.0.10]: https://github.com/taiki-e/pin-project/compare/v1.0.9...v1.0.10
+[1.0.9]: https://github.com/taiki-e/pin-project/compare/v1.0.8...v1.0.9
+[1.0.8]: https://github.com/taiki-e/pin-project/compare/v1.0.7...v1.0.8
+[1.0.7]: https://github.com/taiki-e/pin-project/compare/v1.0.6...v1.0.7
+[1.0.6]: https://github.com/taiki-e/pin-project/compare/v1.0.5...v1.0.6
+[1.0.5]: https://github.com/taiki-e/pin-project/compare/v1.0.4...v1.0.5
+[1.0.4]: https://github.com/taiki-e/pin-project/compare/v1.0.3...v1.0.4
+[1.0.3]: https://github.com/taiki-e/pin-project/compare/v1.0.2...v1.0.3
+[1.0.2]: https://github.com/taiki-e/pin-project/compare/v1.0.1...v1.0.2
+[1.0.1]: https://github.com/taiki-e/pin-project/compare/v1.0.0...v1.0.1
+[1.0.0]: https://github.com/taiki-e/pin-project/compare/v1.0.0-alpha.1...v1.0.0
+[1.0.0-alpha.1]: https://github.com/taiki-e/pin-project/compare/v0.4.23...v1.0.0-alpha.1
+[0.4.30]: https://github.com/taiki-e/pin-project/compare/v0.4.29...v0.4.30
+[0.4.29]: https://github.com/taiki-e/pin-project/compare/v0.4.28...v0.4.29
+[0.4.28]: https://github.com/taiki-e/pin-project/compare/v0.4.27...v0.4.28
+[0.4.27]: https://github.com/taiki-e/pin-project/compare/v0.4.26...v0.4.27
+[0.4.26]: https://github.com/taiki-e/pin-project/compare/v0.4.25...v0.4.26
+[0.4.25]: https://github.com/taiki-e/pin-project/compare/v0.4.24...v0.4.25
+[0.4.24]: https://github.com/taiki-e/pin-project/compare/v0.4.23...v0.4.24
+[0.4.23]: https://github.com/taiki-e/pin-project/compare/v0.4.22...v0.4.23
+[0.4.22]: https://github.com/taiki-e/pin-project/compare/v0.4.21...v0.4.22
+[0.4.21]: https://github.com/taiki-e/pin-project/compare/v0.4.20...v0.4.21
+[0.4.20]: https://github.com/taiki-e/pin-project/compare/v0.4.19...v0.4.20
+[0.4.19]: https://github.com/taiki-e/pin-project/compare/v0.4.18...v0.4.19
+[0.4.18]: https://github.com/taiki-e/pin-project/compare/v0.4.17...v0.4.18
+[0.4.17]: https://github.com/taiki-e/pin-project/compare/v0.4.16...v0.4.17
+[0.4.16]: https://github.com/taiki-e/pin-project/compare/v0.4.15...v0.4.16
+[0.4.15]: https://github.com/taiki-e/pin-project/compare/v0.4.14...v0.4.15
+[0.4.14]: https://github.com/taiki-e/pin-project/compare/v0.4.13...v0.4.14
+[0.4.13]: https://github.com/taiki-e/pin-project/compare/v0.4.11...v0.4.13
+[0.4.12]: https://github.com/taiki-e/pin-project/compare/v0.4.10...v0.4.12
+[0.4.11]: https://github.com/taiki-e/pin-project/compare/v0.4.10...v0.4.11
+[0.4.10]: https://github.com/taiki-e/pin-project/compare/v0.4.9...v0.4.10
+[0.4.9]: https://github.com/taiki-e/pin-project/compare/v0.4.8...v0.4.9
+[0.4.8]: https://github.com/taiki-e/pin-project/compare/v0.4.7...v0.4.8
+[0.4.7]: https://github.com/taiki-e/pin-project/compare/v0.4.6...v0.4.7
+[0.4.6]: https://github.com/taiki-e/pin-project/compare/v0.4.5...v0.4.6
+[0.4.5]: https://github.com/taiki-e/pin-project/compare/v0.4.4...v0.4.5
+[0.4.4]: https://github.com/taiki-e/pin-project/compare/v0.4.3...v0.4.4
+[0.4.3]: https://github.com/taiki-e/pin-project/compare/v0.4.2...v0.4.3
+[0.4.2]: https://github.com/taiki-e/pin-project/compare/v0.4.1...v0.4.2
+[0.4.1]: https://github.com/taiki-e/pin-project/compare/v0.4.0...v0.4.1
+[0.4.0]: https://github.com/taiki-e/pin-project/compare/v0.4.0-beta.1...v0.4.0
+[0.4.0-beta.1]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.11...v0.4.0-beta.1
+[0.4.0-alpha.11]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.10...v0.4.0-alpha.11
+[0.4.0-alpha.10]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.9...v0.4.0-alpha.10
+[0.4.0-alpha.9]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.8...v0.4.0-alpha.9
+[0.4.0-alpha.8]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.7...v0.4.0-alpha.8
+[0.4.0-alpha.7]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.6...v0.4.0-alpha.7
+[0.4.0-alpha.6]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.5...v0.4.0-alpha.6
+[0.4.0-alpha.5]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.4...v0.4.0-alpha.5
+[0.4.0-alpha.4]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.3...v0.4.0-alpha.4
+[0.4.0-alpha.3]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.2...v0.4.0-alpha.3
+[0.4.0-alpha.2]: https://github.com/taiki-e/pin-project/compare/v0.4.0-alpha.1...v0.4.0-alpha.2
+[0.4.0-alpha.1]: https://github.com/taiki-e/pin-project/compare/v0.3.5...v0.4.0-alpha.1
+[0.3.5]: https://github.com/taiki-e/pin-project/compare/v0.3.4...v0.3.5
+[0.3.4]: https://github.com/taiki-e/pin-project/compare/v0.3.3...v0.3.4
+[0.3.3]: https://github.com/taiki-e/pin-project/compare/v0.3.2...v0.3.3
+[0.3.2]: https://github.com/taiki-e/pin-project/compare/v0.3.1...v0.3.2
+[0.3.1]: https://github.com/taiki-e/pin-project/compare/v0.3.0...v0.3.1
+[0.3.0]: https://github.com/taiki-e/pin-project/compare/v0.2.2...v0.3.0
+[0.2.2]: https://github.com/taiki-e/pin-project/compare/v0.2.1...v0.2.2
+[0.2.1]: https://github.com/taiki-e/pin-project/compare/v0.2.0...v0.2.1
+[0.2.0]: https://github.com/taiki-e/pin-project/compare/v0.1.8...v0.2.0
+[0.1.8]: https://github.com/taiki-e/pin-project/compare/v0.1.7...v0.1.8
+[0.1.7]: https://github.com/taiki-e/pin-project/compare/v0.1.6...v0.1.7
+[0.1.6]: https://github.com/taiki-e/pin-project/compare/v0.1.5...v0.1.6
+[0.1.5]: https://github.com/taiki-e/pin-project/compare/v0.1.4...v0.1.5
+[0.1.4]: https://github.com/taiki-e/pin-project/compare/v0.1.3...v0.1.4
+[0.1.3]: https://github.com/taiki-e/pin-project/compare/v0.1.2...v0.1.3
+[0.1.2]: https://github.com/taiki-e/pin-project/compare/v0.1.1...v0.1.2
+[0.1.1]: https://github.com/taiki-e/pin-project/compare/v0.1.0...v0.1.1
+[0.1.0]: https://github.com/taiki-e/pin-project/releases/tag/v0.1.0
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new file mode 100644
index 0000000000..502ac21268
--- /dev/null
+++ b/third_party/rust/pin-project/Cargo.lock
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new file mode 100644
index 0000000000..9ad85ba371
--- /dev/null
+++ b/third_party/rust/pin-project/Cargo.toml
@@ -0,0 +1,54 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
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+name = "pin-project"
+version = "1.0.12"
+exclude = [
+    "/.*",
+    "/ci",
+    "/tools",
+]
+description = """
+A crate for safe and ergonomic pin-projection.
+"""
+readme = "README.md"
+keywords = [
+    "pin",
+    "macros",
+    "attribute",
+]
+categories = [
+    "no-std",
+    "rust-patterns",
+]
+license = "Apache-2.0 OR MIT"
+repository = "https://github.com/taiki-e/pin-project"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies.pin-project-internal]
+version = "=1.0.12"
+
+[dev-dependencies.macrotest]
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+
+[dev-dependencies.rustversion]
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+
+[dev-dependencies.static_assertions]
+version = "1"
+
+[dev-dependencies.trybuild]
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diff --git a/third_party/rust/pin-project/LICENSE-APACHE b/third_party/rust/pin-project/LICENSE-APACHE
new file mode 100644
index 0000000000..f433b1a53f
--- /dev/null
+++ b/third_party/rust/pin-project/LICENSE-APACHE
@@ -0,0 +1,177 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
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+      any Contribution intentionally submitted for inclusion in the Work
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+   6. Trademarks. This License does not grant permission to use the trade
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+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
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+      defend, and hold each Contributor harmless for any liability
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+
+   END OF TERMS AND CONDITIONS
diff --git a/third_party/rust/pin-project/LICENSE-MIT b/third_party/rust/pin-project/LICENSE-MIT
new file mode 100644
index 0000000000..31aa79387f
--- /dev/null
+++ b/third_party/rust/pin-project/LICENSE-MIT
@@ -0,0 +1,23 @@
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/pin-project/README.md b/third_party/rust/pin-project/README.md
new file mode 100644
index 0000000000..0a306540c6
--- /dev/null
+++ b/third_party/rust/pin-project/README.md
@@ -0,0 +1,99 @@
+# pin-project
+
+[![crates.io](https://img.shields.io/crates/v/pin-project?style=flat-square&logo=rust)](https://crates.io/crates/pin-project)
+[![docs.rs](https://img.shields.io/badge/docs.rs-pin--project-blue?style=flat-square&logo=docs.rs)](https://docs.rs/pin-project)
+[![license](https://img.shields.io/badge/license-Apache--2.0_OR_MIT-blue?style=flat-square)](#license)
+[![rustc](https://img.shields.io/badge/rustc-1.37+-blue?style=flat-square&logo=rust)](https://www.rust-lang.org)
+[![build status](https://img.shields.io/github/workflow/status/taiki-e/pin-project/CI/main?style=flat-square&logo=github)](https://github.com/taiki-e/pin-project/actions)
+
+A crate for safe and ergonomic [pin-projection].
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+pin-project = "1"
+```
+
+*Compiler support: requires rustc 1.37+*
+
+## Examples
+
+[`#[pin_project]`][`pin_project`] attribute creates projection types
+covering all the fields of struct or enum.
+
+```rust
+use pin_project::pin_project;
+use std::pin::Pin;
+
+#[pin_project]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+impl<T, U> Struct<T, U> {
+    fn method(self: Pin<&mut Self>) {
+        let this = self.project();
+        let _: Pin<&mut T> = this.pinned; // Pinned reference to the field
+        let _: &mut U = this.unpinned; // Normal reference to the field
+    }
+}
+```
+
+[*code like this will be generated*][struct-default-expanded]
+
+To use `#[pin_project]` on enums, you need to name the projection type
+returned from the method.
+
+```rust
+use pin_project::pin_project;
+use std::pin::Pin;
+
+#[pin_project(project = EnumProj)]
+enum Enum<T, U> {
+    Pinned(#[pin] T),
+    Unpinned(U),
+}
+
+impl<T, U> Enum<T, U> {
+    fn method(self: Pin<&mut Self>) {
+        match self.project() {
+            EnumProj::Pinned(x) => {
+                let _: Pin<&mut T> = x;
+            }
+            EnumProj::Unpinned(y) => {
+                let _: &mut U = y;
+            }
+        }
+    }
+}
+```
+
+[*code like this will be generated*][enum-default-expanded]
+
+See [documentation](https://docs.rs/pin-project) for more details, and
+see [examples] directory for more examples and generated code.
+
+## Related Projects
+
+- [pin-project-lite]: A lightweight version of pin-project written with declarative macros.
+
+[`pin_project`]: https://docs.rs/pin-project/1/pin_project/attr.pin_project.html
+[enum-default-expanded]: examples/enum-default-expanded.rs
+[examples]: examples/README.md
+[pin-project-lite]: https://github.com/taiki-e/pin-project-lite
+[pin-projection]: https://doc.rust-lang.org/std/pin/index.html#projections-and-structural-pinning
+[struct-default-expanded]: examples/struct-default-expanded.rs
+
+## License
+
+Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
+[MIT license](LICENSE-MIT) at your option.
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall
+be dual licensed as above, without any additional terms or conditions.
diff --git a/third_party/rust/pin-project/examples/README.md b/third_party/rust/pin-project/examples/README.md
new file mode 100644
index 0000000000..0f30a7fc82
--- /dev/null
+++ b/third_party/rust/pin-project/examples/README.md
@@ -0,0 +1,39 @@
+# Examples and generated code of each feature of pin-project
+
+### Basic usage of `#[pin_project]` on structs
+
+- [example](struct-default.rs)
+- [generated code](struct-default-expanded.rs)
+
+### Basic usage of `#[pin_project]` on enums
+
+- [example](enum-default.rs)
+- [generated code](enum-default-expanded.rs)
+
+### Manual implementation of `Unpin` by `UnsafeUnpin`
+
+- [example](unsafe_unpin.rs)
+- [generated code](unsafe_unpin-expanded.rs)
+- [`UnsafeUnpin` documentation](https://docs.rs/pin-project/1/pin_project/trait.UnsafeUnpin.html)
+
+### Manual implementation of `Drop` by `#[pinned_drop]`
+
+- [example](pinned_drop.rs)
+- [generated code](pinned_drop-expanded.rs)
+- [`#[pinned_drop]` documentation](https://docs.rs/pin-project/1/pin_project/attr.pinned_drop.html)
+
+### `project_replace()` method
+
+- [example](project_replace.rs)
+- [generated code](project_replace-expanded.rs)
+- [`project_replace()` documentation](https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#project_replace-method)
+
+### Ensure `!Unpin` by `#[pin_project(!Unpin)]`
+
+- [example](not_unpin.rs)
+- [generated code](not_unpin-expanded.rs)
+- [`!Unpin` documentation](https://docs.rs/pin-project/1/pin_project/attr.pin_project.html#unpin)
+
+Note: These generated code examples are the little simplified version of the
+actual generated code. See [expansion tests](../tests#expansion-tests-expand-expandtestrs) if you
+want to see the exact version of the actual generated code.
diff --git a/third_party/rust/pin-project/examples/enum-default-expanded.rs b/third_party/rust/pin-project/examples/enum-default-expanded.rs
new file mode 100644
index 0000000000..459ca39b03
--- /dev/null
+++ b/third_party/rust/pin-project/examples/enum-default-expanded.rs
@@ -0,0 +1,101 @@
+// Original code (./enum-default.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::pin_project;
+//
+// #[pin_project(project = EnumProj)]
+// enum Enum<T, U> {
+//     Pinned(#[pin] T),
+//     Unpinned(U),
+// }
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(
+    clippy::needless_lifetimes,
+    clippy::just_underscores_and_digits,
+    clippy::used_underscore_binding
+)]
+
+use pin_project::pin_project;
+
+// #[pin_project(project = EnumProj)]
+enum Enum<T, U> {
+    Pinned(/* #[pin] */ T),
+    Unpinned(U),
+}
+
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Pinned(::pin_project::__private::Pin<&'pin mut (T)>),
+    Unpinned(&'pin mut (U)),
+}
+
+const _: () = {
+    // When `#[pin_project]` is used on enums, only named projection types and
+    // methods are generated because there is no way to access variants of
+    // projected types without naming it.
+    // (When `#[pin_project]` is used on structs, both methods are always generated.)
+
+    impl<T, U> Enum<T, U> {
+        fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Pinned(_0) => {
+                        EnumProj::Pinned(::pin_project::__private::Pin::new_unchecked(_0))
+                    }
+                    Self::Unpinned(_0) => EnumProj::Unpinned(_0),
+                }
+            }
+        }
+    }
+
+    // Automatically create the appropriate conditional `Unpin` implementation.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/53.
+    // for details.
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: ::pin_project::__private::AlwaysUnpin<
+            'pin,
+            (::pin_project::__private::PhantomData<T>, ::pin_project::__private::PhantomData<U>),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> ::pin_project::__private::Unpin for Enum<T, U> where
+        __Enum<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+    // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Enum<T, U> where
+        __Enum<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+
+    // Ensure that enum does not implement `Drop`.
+    //
+    // See ./struct-default-expanded.rs for details.
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+    // write a non-functional `PinnedDrop` impls.
+    #[doc(hidden)]
+    impl<T, U> ::pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+    }
+
+    // We don't need to check for `#[repr(packed)]`,
+    // since it does not apply to enums.
+};
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/enum-default.rs b/third_party/rust/pin-project/examples/enum-default.rs
new file mode 100644
index 0000000000..bd3f2e636c
--- /dev/null
+++ b/third_party/rust/pin-project/examples/enum-default.rs
@@ -0,0 +1,13 @@
+// See ./enum-default-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use pin_project::pin_project;
+
+#[pin_project(project = EnumProj)]
+enum Enum<T, U> {
+    Pinned(#[pin] T),
+    Unpinned(U),
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/not_unpin-expanded.rs b/third_party/rust/pin-project/examples/not_unpin-expanded.rs
new file mode 100644
index 0000000000..5700c120a5
--- /dev/null
+++ b/third_party/rust/pin-project/examples/not_unpin-expanded.rs
@@ -0,0 +1,125 @@
+// Original code (./not_unpin.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::pin_project;
+//
+// #[pin_project(!Unpin)]
+// pub struct Struct<T, U> {
+//     #[pin]
+//     pinned: T,
+//     unpinned: U,
+// }
+//
+// fn main() {
+//     fn _is_unpin<T: Unpin>() {}
+//     // _is_unpin::<Struct<(), ()>>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned
+// }
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes)]
+
+use pin_project::pin_project;
+
+// #[pin_project(!Unpin)]
+pub struct Struct<T, U> {
+    // #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+const _: () = {
+    pub(crate) struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    pub(crate) struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+
+    impl<T, U> Struct<T, U> {
+        pub(crate) fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        pub(crate) fn project_ref<'pin>(
+            self: ::pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+
+    // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+    // struct.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
+    // for details.
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+
+    // Create `Unpin` impl that has trivial `Unpin` bounds.
+    //
+    // See https://github.com/taiki-e/pin-project/issues/102#issuecomment-540472282
+    // for details.
+    impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
+        ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>:
+            ::pin_project::__private::Unpin
+    {
+    }
+    // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+    //
+    // To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
+    // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
+    // impl, they'll get a "conflicting implementations of trait" error when
+    // coherence checks are run.
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct<T, U> where
+        ::pin_project::__private::Wrapper<'pin, ::pin_project::__private::PhantomPinned>:
+            ::pin_project::__private::Unpin
+    {
+    }
+
+    // Ensure that struct does not implement `Drop`.
+    //
+    // See ./struct-default-expanded.rs for details.
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+    // write a non-functional `PinnedDrop` impls.
+    #[doc(hidden)]
+    impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+
+fn main() {
+    fn _is_unpin<T: Unpin>() {}
+    // _is_unpin::<Struct<(), ()>>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned
+}
diff --git a/third_party/rust/pin-project/examples/not_unpin.rs b/third_party/rust/pin-project/examples/not_unpin.rs
new file mode 100644
index 0000000000..2ad72a87f2
--- /dev/null
+++ b/third_party/rust/pin-project/examples/not_unpin.rs
@@ -0,0 +1,17 @@
+// See ./not_unpin-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use pin_project::pin_project;
+
+#[pin_project(!Unpin)]
+pub struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {
+    fn _is_unpin<T: Unpin>() {}
+    // _is_unpin::<Struct<(), ()>>(); //~ ERROR `std::marker::PhantomPinned` cannot be unpinned
+}
diff --git a/third_party/rust/pin-project/examples/pinned_drop-expanded.rs b/third_party/rust/pin-project/examples/pinned_drop-expanded.rs
new file mode 100644
index 0000000000..82207b60b1
--- /dev/null
+++ b/third_party/rust/pin-project/examples/pinned_drop-expanded.rs
@@ -0,0 +1,154 @@
+// Original code (./pinned_drop.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use std::pin::Pin;
+//
+// use pin_project::{pin_project, pinned_drop};
+//
+// #[pin_project(PinnedDrop)]
+// pub struct Struct<'a, T> {
+//     was_dropped: &'a mut bool,
+//     #[pin]
+//     field: T,
+// }
+//
+// #[pinned_drop]
+// fn drop_Struct<T>(mut this: Pin<&mut Struct<'_, T>>) {
+//     **this.project().was_dropped = true;
+// }
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes, clippy::mut_mut)]
+
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+// #[pin_project(PinnedDrop)]
+pub struct Struct<'a, T> {
+    was_dropped: &'a mut bool,
+    // #[pin]
+    field: T,
+}
+
+const _: () = {
+    pub(crate) struct __StructProjection<'pin, 'a, T>
+    where
+        Struct<'a, T>: 'pin,
+    {
+        was_dropped: &'pin mut (&'a mut bool),
+        field: ::pin_project::__private::Pin<&'pin mut (T)>,
+    }
+    pub(crate) struct __StructProjectionRef<'pin, 'a, T>
+    where
+        Struct<'a, T>: 'pin,
+    {
+        was_dropped: &'pin (&'a mut bool),
+        field: ::pin_project::__private::Pin<&'pin (T)>,
+    }
+
+    impl<'a, T> Struct<'a, T> {
+        pub(crate) fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, 'a, T> {
+            unsafe {
+                let Self { was_dropped, field } = self.get_unchecked_mut();
+                __StructProjection {
+                    was_dropped,
+                    field: ::pin_project::__private::Pin::new_unchecked(field),
+                }
+            }
+        }
+        pub(crate) fn project_ref<'pin>(
+            self: ::pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, 'a, T> {
+            unsafe {
+                let Self { was_dropped, field } = self.get_ref();
+                __StructProjectionRef {
+                    was_dropped,
+                    field: ::pin_project::__private::Pin::new_unchecked(field),
+                }
+            }
+        }
+    }
+
+    // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+    // struct.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
+    // for details.
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<'a, T>(this: &Struct<'a, T>) {
+        let _ = &this.was_dropped;
+        let _ = &this.field;
+    }
+
+    impl<'a, T> ::pin_project::__private::Drop for Struct<'a, T> {
+        fn drop(&mut self) {
+            // Safety - we're in 'drop', so we know that 'self' will
+            // never move again.
+            let pinned_self = unsafe { ::pin_project::__private::Pin::new_unchecked(self) };
+            // We call `pinned_drop` only once. Since `PinnedDrop::drop`
+            // is an unsafe method and a private API, it is never called again in safe
+            // code *unless the user uses a maliciously crafted macro*.
+            unsafe {
+                ::pin_project::__private::PinnedDrop::drop(pinned_self);
+            }
+        }
+    }
+
+    // Automatically create the appropriate conditional `Unpin` implementation.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/53.
+    // for details.
+    pub struct __Struct<'pin, 'a, T> {
+        __pin_project_use_generics: ::pin_project::__private::AlwaysUnpin<'pin, (T)>,
+        __field0: T,
+        __lifetime0: &'a (),
+    }
+    impl<'pin, 'a, T> ::pin_project::__private::Unpin for Struct<'a, T> where
+        __Struct<'pin, 'a, T>: ::pin_project::__private::Unpin
+    {
+    }
+    // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+    #[doc(hidden)]
+    unsafe impl<'pin, 'a, T> ::pin_project::UnsafeUnpin for Struct<'a, T> where
+        __Struct<'pin, 'a, T>: ::pin_project::__private::Unpin
+    {
+    }
+};
+
+// Implementing `PinnedDrop::drop` is safe, but calling it is not safe.
+// This is because destructors can be called multiple times in safe code and
+// [double dropping is unsound](https://github.com/rust-lang/rust/pull/62360).
+//
+// Ideally, it would be desirable to be able to forbid manual calls in
+// the same way as `Drop::drop`, but the library cannot do it. So, by using
+// macros and replacing them with private traits, we prevent users from
+// calling `PinnedDrop::drop`.
+//
+// Users can implement [`Drop`] safely using `#[pinned_drop]` and can drop a
+// type that implements `PinnedDrop` using the [`drop`] function safely.
+// **Do not call or implement this trait directly.**
+#[doc(hidden)]
+impl<T> ::pin_project::__private::PinnedDrop for Struct<'_, T> {
+    // Since calling it twice on the same object would be UB,
+    // this method is unsafe.
+    unsafe fn drop(self: Pin<&mut Self>) {
+        #[allow(clippy::needless_pass_by_value)]
+        fn __drop_inner<T>(__self: Pin<&mut Struct<'_, T>>) {
+            // A dummy `__drop_inner` function to prevent users call outer `__drop_inner`.
+            fn __drop_inner() {}
+
+            **__self.project().was_dropped = true;
+        }
+        __drop_inner(self);
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/pinned_drop.rs b/third_party/rust/pin-project/examples/pinned_drop.rs
new file mode 100644
index 0000000000..6fb87193f6
--- /dev/null
+++ b/third_party/rust/pin-project/examples/pinned_drop.rs
@@ -0,0 +1,23 @@
+// See ./pinned_drop-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop)]
+pub struct Struct<'a, T> {
+    was_dropped: &'a mut bool,
+    #[pin]
+    field: T,
+}
+
+#[pinned_drop]
+impl<T> PinnedDrop for Struct<'_, T> {
+    fn drop(self: Pin<&mut Self>) {
+        **self.project().was_dropped = true;
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/project_replace-expanded.rs b/third_party/rust/pin-project/examples/project_replace-expanded.rs
new file mode 100644
index 0000000000..445e5705e1
--- /dev/null
+++ b/third_party/rust/pin-project/examples/project_replace-expanded.rs
@@ -0,0 +1,156 @@
+// Original code (./struct-default.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::pin_project;
+//
+// #[pin_project(project_replace)]
+// struct Struct<T, U> {
+//     #[pin]
+//     pinned: T,
+//     unpinned: U,
+// }
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes)]
+
+use pin_project::pin_project;
+
+// #[pin_project(project_replace)]
+struct Struct<T, U> {
+    // #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+const _: () = {
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    struct __StructProjectionOwned<T, U> {
+        pinned: ::pin_project::__private::PhantomData<T>,
+        unpinned: U,
+    }
+
+    impl<T, U> Struct<T, U> {
+        fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        fn project_ref<'pin>(
+            self: ::pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        fn project_replace(
+            self: ::pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> __StructProjectionOwned<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+
+                // Destructors will run in reverse order, so next create a guard to overwrite
+                // `self` with the replacement value without calling destructors.
+                let __guard =
+                    ::pin_project::__private::UnsafeOverwriteGuard::new(__self_ptr, __replacement);
+
+                let Self { pinned, unpinned } = &mut *__self_ptr;
+
+                // First, extract all the unpinned fields
+                let __result = __StructProjectionOwned {
+                    pinned: ::pin_project::__private::PhantomData,
+                    unpinned: ::pin_project::__private::ptr::read(unpinned),
+                };
+
+                // Now create guards to drop all the pinned fields
+                //
+                // Due to a compiler bug (https://github.com/rust-lang/rust/issues/47949)
+                // this must be in its own scope, or else `__result` will not be dropped
+                // if any of the destructors panic.
+                {
+                    let __guard = ::pin_project::__private::UnsafeDropInPlaceGuard::new(pinned);
+                }
+
+                // Finally, return the result
+                __result
+            }
+        }
+    }
+
+    // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+    // struct.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
+    // for details.
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+
+    // Automatically create the appropriate conditional `Unpin` implementation.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/53.
+    // for details.
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: ::pin_project::__private::AlwaysUnpin<
+            'pin,
+            (::pin_project::__private::PhantomData<T>, ::pin_project::__private::PhantomData<U>),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
+        __Struct<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+    // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct<T, U> where
+        __Struct<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+
+    // Ensure that struct does not implement `Drop`.
+    //
+    // See ./struct-default-expanded.rs for details.
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+    // write a non-functional `PinnedDrop` impls.
+    #[doc(hidden)]
+    impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/project_replace.rs b/third_party/rust/pin-project/examples/project_replace.rs
new file mode 100644
index 0000000000..99cec18472
--- /dev/null
+++ b/third_party/rust/pin-project/examples/project_replace.rs
@@ -0,0 +1,14 @@
+// See ./struct-default-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use pin_project::pin_project;
+
+#[pin_project(project_replace)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/struct-default-expanded.rs b/third_party/rust/pin-project/examples/struct-default-expanded.rs
new file mode 100644
index 0000000000..d6610993d3
--- /dev/null
+++ b/third_party/rust/pin-project/examples/struct-default-expanded.rs
@@ -0,0 +1,155 @@
+// Original code (./struct-default.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::pin_project;
+//
+// #[pin_project]
+// struct Struct<T, U> {
+//     #[pin]
+//     pinned: T,
+//     unpinned: U,
+// }
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes)]
+
+use pin_project::pin_project;
+
+// #[pin_project]
+struct Struct<T, U> {
+    // #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+const _: () = {
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+
+    impl<T, U> Struct<T, U> {
+        fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        fn project_ref<'pin>(
+            self: ::pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+
+    // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+    // struct.
+    //
+    // Taking a reference to a packed field is UB, and applying
+    // `#[forbid(unaligned_references)]` makes sure that doing this is a hard error.
+    //
+    // If the struct ends up having #[repr(packed)] applied somehow,
+    // this will generate an (unfriendly) error message. Under all reasonable
+    // circumstances, we'll detect the #[repr(packed)] attribute, and generate
+    // a much nicer error above.
+    //
+    // See https://github.com/taiki-e/pin-project/pull/34 for more details.
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+
+    // Automatically create the appropriate conditional `Unpin` implementation.
+    //
+    // Basically this is equivalent to the following code:
+    //
+    // ```rust
+    // impl<T, U> Unpin for Struct<T, U> where T: Unpin {}
+    // ```
+    //
+    // However, if struct is public and there is a private type field,
+    // this would cause an E0446 (private type in public interface).
+    //
+    // When RFC 2145 is implemented (rust-lang/rust#48054),
+    // this will become a lint, rather then a hard error.
+    //
+    // As a workaround for this, we generate a new struct, containing all of
+    // the pinned fields from our #[pin_project] type. This struct is declared
+    // within a function, which makes it impossible to be named by user code.
+    // This guarantees that it will use the default auto-trait impl for Unpin -
+    // that is, it will implement Unpin iff all of its fields implement Unpin.
+    // This type can be safely declared as 'public', satisfying the privacy
+    // checker without actually allowing user code to access it.
+    //
+    // This allows users to apply the #[pin_project] attribute to types
+    // regardless of the privacy of the types of their fields.
+    //
+    // See also https://github.com/taiki-e/pin-project/pull/53.
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: ::pin_project::__private::AlwaysUnpin<
+            'pin,
+            (::pin_project::__private::PhantomData<T>, ::pin_project::__private::PhantomData<U>),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
+        __Struct<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+    // A dummy impl of `UnsafeUnpin`, to ensure that the user cannot implement it.
+    //
+    // To ensure that users don't accidentally write a non-functional `UnsafeUnpin`
+    // impls, we emit one ourselves. If the user ends up writing an `UnsafeUnpin`
+    // impl, they'll get a "conflicting implementations of trait" error when
+    // coherence checks are run.
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> ::pin_project::UnsafeUnpin for Struct<T, U> where
+        __Struct<'pin, T, U>: ::pin_project::__private::Unpin
+    {
+    }
+
+    // Ensure that struct does not implement `Drop`.
+    //
+    // If you attempt to provide an Drop impl, the blanket impl will
+    // then apply to your type, causing a compile-time error due to
+    // the conflict with the second impl.
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+    // write a non-functional `PinnedDrop` impls.
+    #[doc(hidden)]
+    impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/struct-default.rs b/third_party/rust/pin-project/examples/struct-default.rs
new file mode 100644
index 0000000000..46808a5827
--- /dev/null
+++ b/third_party/rust/pin-project/examples/struct-default.rs
@@ -0,0 +1,14 @@
+// See ./struct-default-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use pin_project::pin_project;
+
+#[pin_project]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs b/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
new file mode 100644
index 0000000000..e9c7abcedd
--- /dev/null
+++ b/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
@@ -0,0 +1,107 @@
+// Original code (./unsafe_unpin.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::{pin_project, UnsafeUnpin};
+//
+// #[pin_project(UnsafeUnpin)]
+// pub struct Struct<T, U> {
+//     #[pin]
+//     pinned: T,
+//     unpinned: U,
+// }
+//
+// unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes)]
+
+use pin_project::{pin_project, UnsafeUnpin};
+
+// #[pin_project(UnsafeUnpin)]
+pub struct Struct<T, U> {
+    // #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+const _: () = {
+    pub(crate) struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    pub(crate) struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+
+    impl<T, U> Struct<T, U> {
+        pub(crate) fn project<'pin>(
+            self: ::pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        pub(crate) fn project_ref<'pin>(
+            self: ::pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+
+    // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+    // struct.
+    //
+    // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
+    // for details.
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+
+    // Implement `Unpin` via `UnsafeUnpin`.
+    impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
+        ::pin_project::__private::Wrapper<'pin, Self>: ::pin_project::UnsafeUnpin
+    {
+    }
+
+    // Ensure that struct does not implement `Drop`.
+    //
+    // See ./struct-default-expanded.rs for details.
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+    // write a non-functional `PinnedDrop` impls.
+    #[doc(hidden)]
+    impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/examples/unsafe_unpin.rs b/third_party/rust/pin-project/examples/unsafe_unpin.rs
new file mode 100644
index 0000000000..5ec0cd22ba
--- /dev/null
+++ b/third_party/rust/pin-project/examples/unsafe_unpin.rs
@@ -0,0 +1,16 @@
+// See ./unsafe_unpin-expanded.rs for generated code.
+
+#![allow(dead_code)]
+
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(UnsafeUnpin)]
+pub struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/src/lib.rs b/third_party/rust/pin-project/src/lib.rs
new file mode 100644
index 0000000000..5fa9298011
--- /dev/null
+++ b/third_party/rust/pin-project/src/lib.rs
@@ -0,0 +1,315 @@
+//! A crate for safe and ergonomic [pin-projection].
+//!
+//! # Examples
+//!
+//! [`#[pin_project]`][`pin_project`] attribute creates projection types
+//! covering all the fields of struct or enum.
+//!
+//! ```rust
+//! use std::pin::Pin;
+//!
+//! use pin_project::pin_project;
+//!
+//! #[pin_project]
+//! struct Struct<T, U> {
+//!     #[pin]
+//!     pinned: T,
+//!     unpinned: U,
+//! }
+//!
+//! impl<T, U> Struct<T, U> {
+//!     fn method(self: Pin<&mut Self>) {
+//!         let this = self.project();
+//!         let _: Pin<&mut T> = this.pinned; // Pinned reference to the field
+//!         let _: &mut U = this.unpinned; // Normal reference to the field
+//!     }
+//! }
+//! ```
+//!
+//! [*code like this will be generated*][struct-default-expanded]
+//!
+//! To use `#[pin_project]` on enums, you need to name the projection type
+//! returned from the method.
+//!
+//! ```rust
+//! use std::pin::Pin;
+//!
+//! use pin_project::pin_project;
+//!
+//! #[pin_project(project = EnumProj)]
+//! enum Enum<T, U> {
+//!     Pinned(#[pin] T),
+//!     Unpinned(U),
+//! }
+//!
+//! impl<T, U> Enum<T, U> {
+//!     fn method(self: Pin<&mut Self>) {
+//!         match self.project() {
+//!             EnumProj::Pinned(x) => {
+//!                 let _: Pin<&mut T> = x;
+//!             }
+//!             EnumProj::Unpinned(y) => {
+//!                 let _: &mut U = y;
+//!             }
+//!         }
+//!     }
+//! }
+//! ```
+//!
+//! [*code like this will be generated*][enum-default-expanded]
+//!
+//! See [`#[pin_project]`][`pin_project`] attribute for more details, and
+//! see [examples] directory for more examples and generated code.
+//!
+//! [examples]: https://github.com/taiki-e/pin-project/blob/HEAD/examples/README.md
+//! [enum-default-expanded]: https://github.com/taiki-e/pin-project/blob/HEAD/examples/enum-default-expanded.rs
+//! [pin-projection]: core::pin#projections-and-structural-pinning
+//! [struct-default-expanded]: https://github.com/taiki-e/pin-project/blob/HEAD/examples/struct-default-expanded.rs
+
+#![no_std]
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_variables)
+    )
+))]
+#![warn(missing_docs, rust_2018_idioms, single_use_lifetimes, unreachable_pub)]
+#![warn(
+    clippy::pedantic,
+    // lints for public library
+    clippy::alloc_instead_of_core,
+    clippy::exhaustive_enums,
+    clippy::exhaustive_structs,
+    clippy::std_instead_of_alloc,
+    clippy::std_instead_of_core,
+    // lints that help writing unsafe code
+    clippy::default_union_representation,
+    clippy::trailing_empty_array,
+    clippy::transmute_undefined_repr,
+    clippy::undocumented_unsafe_blocks,
+)]
+#![allow(clippy::needless_doctest_main)]
+
+#[doc(inline)]
+pub use pin_project_internal::pin_project;
+#[doc(inline)]
+pub use pin_project_internal::pinned_drop;
+
+/// A trait used for custom implementations of [`Unpin`].
+///
+/// This trait is used in conjunction with the `UnsafeUnpin` argument to
+/// the [`#[pin_project]`][macro@pin_project] attribute.
+///
+/// # Safety
+///
+/// The Rust [`Unpin`] trait is safe to implement - by itself,
+/// implementing it cannot lead to [undefined behavior][undefined-behavior].
+/// Undefined behavior can only occur when other unsafe code is used.
+///
+/// It turns out that using pin projections, which requires unsafe code,
+/// imposes additional requirements on an [`Unpin`] impl. Normally, all of this
+/// unsafety is contained within this crate, ensuring that it's impossible for
+/// you to violate any of the guarantees required by pin projection.
+///
+/// However, things change if you want to provide a custom [`Unpin`] impl
+/// for your `#[pin_project]` type. As stated in [the Rust
+/// documentation][pin-projection], you must be sure to only implement [`Unpin`]
+/// when all of your `#[pin]` fields (i.e. structurally pinned fields) are also
+/// [`Unpin`].
+///
+/// To help highlight this unsafety, the `UnsafeUnpin` trait is provided.
+/// Implementing this trait is logically equivalent to implementing [`Unpin`] -
+/// this crate will generate an [`Unpin`] impl for your type that 'forwards' to
+/// your `UnsafeUnpin` impl. However, this trait is `unsafe` - since your type
+/// uses structural pinning (otherwise, you wouldn't be using this crate!),
+/// you must be sure that your `UnsafeUnpin` impls follows all of
+/// the requirements for an [`Unpin`] impl of a structurally-pinned type.
+///
+/// Note that if you specify `#[pin_project(UnsafeUnpin)]`, but do *not*
+/// provide an impl of `UnsafeUnpin`, your type will never implement [`Unpin`].
+/// This is effectively the same thing as adding a [`PhantomPinned`] to your
+/// type.
+///
+/// Since this trait is `unsafe`, impls of it will be detected by the
+/// `unsafe_code` lint, and by tools like [`cargo geiger`][cargo-geiger].
+///
+/// # Examples
+///
+/// An `UnsafeUnpin` impl which, in addition to requiring that structurally
+/// pinned fields be [`Unpin`], imposes an additional requirement:
+///
+/// ```rust
+/// use pin_project::{pin_project, UnsafeUnpin};
+///
+/// #[pin_project(UnsafeUnpin)]
+/// struct Struct<K, V> {
+///     #[pin]
+///     field_1: K,
+///     field_2: V,
+/// }
+///
+/// unsafe impl<K, V> UnsafeUnpin for Struct<K, V> where K: Unpin + Clone {}
+/// ```
+///
+/// [`PhantomPinned`]: core::marker::PhantomPinned
+/// [cargo-geiger]: https://github.com/rust-secure-code/cargo-geiger
+/// [pin-projection]: core::pin#projections-and-structural-pinning
+/// [undefined-behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
+pub unsafe trait UnsafeUnpin {}
+
+// Not public API.
+#[doc(hidden)]
+pub mod __private {
+    use core::mem::ManuallyDrop;
+    #[doc(hidden)]
+    pub use core::{
+        marker::{PhantomData, PhantomPinned, Unpin},
+        ops::Drop,
+        pin::Pin,
+        ptr,
+    };
+
+    #[doc(hidden)]
+    pub use pin_project_internal::__PinProjectInternalDerive;
+
+    use super::UnsafeUnpin;
+
+    // An internal trait used for custom implementations of [`Drop`].
+    //
+    // **Do not call or implement this trait directly.**
+    //
+    // # Why this trait is private and `#[pinned_drop]` attribute is needed?
+    //
+    // Implementing `PinnedDrop::drop` is safe, but calling it is not safe.
+    // This is because destructors can be called multiple times in safe code and
+    // [double dropping is unsound][rust-lang/rust#62360].
+    //
+    // Ideally, it would be desirable to be able to forbid manual calls in
+    // the same way as [`Drop::drop`], but the library cannot do it. So, by using
+    // macros and replacing them with private traits,
+    // this crate prevent users from calling `PinnedDrop::drop` in safe code.
+    //
+    // This allows implementing [`Drop`] safely using `#[pinned_drop]`.
+    // Also by using the [`drop`] function just like dropping a type that directly
+    // implements [`Drop`], can drop safely a type that implements `PinnedDrop`.
+    //
+    // [rust-lang/rust#62360]: https://github.com/rust-lang/rust/pull/62360
+    #[doc(hidden)]
+    pub trait PinnedDrop {
+        #[doc(hidden)]
+        unsafe fn drop(self: Pin<&mut Self>);
+    }
+
+    // This is an internal helper struct used by `pin-project-internal`.
+    // This allows us to force an error if the user tries to provide
+    // a regular `Unpin` impl when they specify the `UnsafeUnpin` argument.
+    // This is why we need Wrapper:
+    //
+    // Supposed we have the following code:
+    //
+    // ```rust
+    // #[pin_project(UnsafeUnpin)]
+    // struct MyStruct<T> {
+    //     #[pin] field: T
+    // }
+    //
+    // impl<T> Unpin for MyStruct<T> where MyStruct<T>: UnsafeUnpin {} // generated by pin-project-internal
+    // impl<T> Unpin for MyStruct<T> where T: Copy // written by the user
+    // ```
+    //
+    // We want this code to be rejected - the user is completely bypassing
+    // `UnsafeUnpin`, and providing an unsound Unpin impl in safe code!
+    //
+    // Unfortunately, the Rust compiler will accept the above code.
+    // Because MyStruct is declared in the same crate as the user-provided impl,
+    // the compiler will notice that `MyStruct<T>: UnsafeUnpin` never holds.
+    //
+    // The solution is to introduce the `Wrapper` struct, which is defined
+    // in the `pin-project` crate.
+    //
+    // We now have code that looks like this:
+    //
+    // ```rust
+    // impl<T> Unpin for MyStruct<T> where Wrapper<MyStruct<T>>: UnsafeUnpin {} // generated by pin-project-internal
+    // impl<T> Unpin for MyStruct<T> where T: Copy // written by the user
+    // ```
+    //
+    // We also have `unsafe impl<T> UnsafeUnpin for Wrapper<T> where T: UnsafeUnpin {}`
+    // in the `pin-project` crate.
+    //
+    // Now, our generated impl has a bound involving a type defined in another
+    // crate - Wrapper. This will cause rust to conservatively assume that
+    // `Wrapper<MyStruct<T>>: UnsafeUnpin` holds, in the interest of preserving
+    // forwards compatibility (in case such an impl is added for Wrapper<T> in
+    // a new version of the crate).
+    //
+    // This will cause rust to reject any other `Unpin` impls for MyStruct<T>,
+    // since it will assume that our generated impl could potentially apply in
+    // any situation.
+    //
+    // This achieves the desired effect - when the user writes
+    // `#[pin_project(UnsafeUnpin)]`, the user must either provide no impl of
+    // `UnsafeUnpin` (which is equivalent to making the type never implement
+    // Unpin), or provide an impl of `UnsafeUnpin`. It is impossible for them to
+    // provide an impl of `Unpin`
+    #[doc(hidden)]
+    pub struct Wrapper<'a, T: ?Sized>(PhantomData<&'a ()>, T);
+
+    // SAFETY: `T` implements UnsafeUnpin.
+    unsafe impl<T: ?Sized + UnsafeUnpin> UnsafeUnpin for Wrapper<'_, T> {}
+
+    // This is an internal helper struct used by `pin-project-internal`.
+    //
+    // See https://github.com/taiki-e/pin-project/pull/53 for more details.
+    #[doc(hidden)]
+    pub struct AlwaysUnpin<'a, T>(PhantomData<&'a ()>, PhantomData<T>);
+
+    impl<T> Unpin for AlwaysUnpin<'_, T> {}
+
+    // This is an internal helper used to ensure a value is dropped.
+    #[doc(hidden)]
+    pub struct UnsafeDropInPlaceGuard<T: ?Sized>(*mut T);
+
+    impl<T: ?Sized> UnsafeDropInPlaceGuard<T> {
+        #[doc(hidden)]
+        pub unsafe fn new(ptr: *mut T) -> Self {
+            Self(ptr)
+        }
+    }
+
+    impl<T: ?Sized> Drop for UnsafeDropInPlaceGuard<T> {
+        fn drop(&mut self) {
+            // SAFETY: the caller of `UnsafeDropInPlaceGuard::new` must guarantee
+            // that `ptr` is valid for drop when this guard is destructed.
+            unsafe {
+                ptr::drop_in_place(self.0);
+            }
+        }
+    }
+
+    // This is an internal helper used to ensure a value is overwritten without
+    // its destructor being called.
+    #[doc(hidden)]
+    pub struct UnsafeOverwriteGuard<T> {
+        target: *mut T,
+        value: ManuallyDrop<T>,
+    }
+
+    impl<T> UnsafeOverwriteGuard<T> {
+        #[doc(hidden)]
+        pub unsafe fn new(target: *mut T, value: T) -> Self {
+            Self { target, value: ManuallyDrop::new(value) }
+        }
+    }
+
+    impl<T> Drop for UnsafeOverwriteGuard<T> {
+        fn drop(&mut self) {
+            // SAFETY: the caller of `UnsafeOverwriteGuard::new` must guarantee
+            // that `target` is valid for writes when this guard is destructed.
+            unsafe {
+                ptr::write(self.target, ptr::read(&*self.value));
+            }
+        }
+    }
+}
diff --git a/third_party/rust/pin-project/tests/README.md b/third_party/rust/pin-project/tests/README.md
new file mode 100644
index 0000000000..b109e71534
--- /dev/null
+++ b/third_party/rust/pin-project/tests/README.md
@@ -0,0 +1,44 @@
+# Tests
+
+To run all tests, run the following command:
+
+```sh
+cargo +nightly test --all
+```
+
+## UI tests (`ui`, `compiletest.rs`)
+
+This checks errors detected by the macro or the Rust compiler in the resulting
+expanded code.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test compiletest
+```
+
+Locally, this test updates the files in the `ui` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`ui` directory after running the test, please commit them.
+
+See also [`trybuild` documentation](https://docs.rs/trybuild).
+
+## Expansion tests (`expand`, `expandtest.rs`)
+
+Similar to ui tests, but instead of checking the compiler output, this checks
+the code generated by macros.
+
+See [examples](../examples/README.md) for descriptions of what the generated
+code does, and why it needs to be generated.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test expandtest
+```
+
+Locally, this test updates the files in the `expand` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`expand` directory after running the test, please commit them.
+
+See also [`macrotest` documentation](https://docs.rs/macrotest).
diff --git a/third_party/rust/pin-project/tests/auxiliary/mod.rs b/third_party/rust/pin-project/tests/auxiliary/mod.rs
new file mode 100644
index 0000000000..1457099160
--- /dev/null
+++ b/third_party/rust/pin-project/tests/auxiliary/mod.rs
@@ -0,0 +1,12 @@
+#![allow(dead_code, unused_macros)]
+
+macro_rules! assert_unpin {
+    ($ty:ty) => {
+        static_assertions::assert_impl_all!($ty: Unpin);
+    };
+}
+macro_rules! assert_not_unpin {
+    ($ty:ty) => {
+        static_assertions::assert_not_impl_all!($ty: Unpin);
+    };
+}
diff --git a/third_party/rust/pin-project/tests/cfg.rs b/third_party/rust/pin-project/tests/cfg.rs
new file mode 100644
index 0000000000..2f5387b671
--- /dev/null
+++ b/third_party/rust/pin-project/tests/cfg.rs
@@ -0,0 +1,184 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+// Refs: https://doc.rust-lang.org/reference/attributes.html
+
+#[macro_use]
+mod auxiliary;
+
+use std::{marker::PhantomPinned, pin::Pin};
+
+use pin_project::pin_project;
+
+struct Always;
+
+// Use this type to check that `cfg(any())` is working properly.
+struct Never(PhantomPinned);
+
+#[test]
+fn cfg() {
+    // structs
+
+    #[pin_project(project_replace)]
+    struct SameName {
+        #[cfg(not(any()))]
+        #[pin]
+        inner: Always,
+        #[cfg(any())]
+        #[pin]
+        inner: Never,
+    }
+
+    assert_unpin!(SameName);
+
+    let _ = SameName { inner: Always };
+
+    #[pin_project(project_replace)]
+    struct DifferentName {
+        #[cfg(not(any()))]
+        #[pin]
+        a: Always,
+        #[cfg(any())]
+        #[pin]
+        n: Never,
+    }
+
+    assert_unpin!(DifferentName);
+
+    let _ = DifferentName { a: Always };
+
+    #[pin_project(project_replace)]
+    struct TupleStruct(
+        #[cfg(not(any()))]
+        #[pin]
+        Always,
+        #[cfg(any())]
+        #[pin]
+        Never,
+    );
+
+    assert_unpin!(TupleStruct);
+
+    let _ = TupleStruct(Always);
+
+    // enums
+
+    #[pin_project(
+        project = VariantProj,
+        project_ref = VariantProjRef,
+        project_replace = VariantProjOwn,
+    )]
+    enum Variant {
+        #[cfg(not(any()))]
+        Inner(#[pin] Always),
+        #[cfg(any())]
+        Inner(#[pin] Never),
+
+        #[cfg(not(any()))]
+        A(#[pin] Always),
+        #[cfg(any())]
+        N(#[pin] Never),
+    }
+
+    assert_unpin!(Variant);
+
+    let _ = Variant::Inner(Always);
+    let _ = Variant::A(Always);
+
+    #[pin_project(
+        project = FieldProj,
+        project_ref = FieldProjRef,
+        project_replace = FieldProjOwn,
+    )]
+    enum Field {
+        SameName {
+            #[cfg(not(any()))]
+            #[pin]
+            inner: Always,
+            #[cfg(any())]
+            #[pin]
+            inner: Never,
+        },
+        DifferentName {
+            #[cfg(not(any()))]
+            #[pin]
+            a: Always,
+            #[cfg(any())]
+            #[pin]
+            n: Never,
+        },
+        TupleVariant(
+            #[cfg(not(any()))]
+            #[pin]
+            Always,
+            #[cfg(any())]
+            #[pin]
+            Never,
+        ),
+    }
+
+    assert_unpin!(Field);
+
+    let _ = Field::SameName { inner: Always };
+    let _ = Field::DifferentName { a: Always };
+    let _ = Field::TupleVariant(Always);
+}
+
+#[test]
+fn cfg_attr() {
+    #[pin_project(project_replace)]
+    struct SameCfg {
+        #[cfg(not(any()))]
+        #[cfg_attr(not(any()), pin)]
+        inner: Always,
+        #[cfg(any())]
+        #[cfg_attr(any(), pin)]
+        inner: Never,
+    }
+
+    assert_unpin!(SameCfg);
+
+    let mut x = SameCfg { inner: Always };
+    let x = Pin::new(&mut x).project();
+    let _: Pin<&mut Always> = x.inner;
+
+    #[pin_project(project_replace)]
+    struct DifferentCfg {
+        #[cfg(not(any()))]
+        #[cfg_attr(any(), pin)]
+        inner: Always,
+        #[cfg(any())]
+        #[cfg_attr(not(any()), pin)]
+        inner: Never,
+    }
+
+    assert_unpin!(DifferentCfg);
+
+    let mut x = DifferentCfg { inner: Always };
+    let x = Pin::new(&mut x).project();
+    let _: &mut Always = x.inner;
+
+    #[cfg_attr(not(any()), pin_project)]
+    struct Foo<T> {
+        #[cfg_attr(not(any()), pin)]
+        inner: T,
+    }
+
+    assert_unpin!(Foo<()>);
+    assert_not_unpin!(Foo<PhantomPinned>);
+
+    let mut x = Foo { inner: 0_u8 };
+    let x = Pin::new(&mut x).project();
+    let _: Pin<&mut u8> = x.inner;
+}
+
+#[test]
+fn cfg_attr_any_packed() {
+    // Since `cfg(any())` can never be true, it is okay for this to pass.
+    #[pin_project(project_replace)]
+    #[cfg_attr(any(), repr(packed))]
+    struct Struct {
+        #[pin]
+        f: u32,
+    }
+}
diff --git a/third_party/rust/pin-project/tests/compiletest.rs b/third_party/rust/pin-project/tests/compiletest.rs
new file mode 100644
index 0000000000..b06e1e8fad
--- /dev/null
+++ b/third_party/rust/pin-project/tests/compiletest.rs
@@ -0,0 +1,16 @@
+#![cfg(not(miri))]
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn ui() {
+    if env::var_os("CI").is_none() {
+        env::set_var("TRYBUILD", "overwrite");
+    }
+
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/**/*.rs");
+    t.pass("tests/run-pass/**/*.rs");
+}
diff --git a/third_party/rust/pin-project/tests/drop_order.rs b/third_party/rust/pin-project/tests/drop_order.rs
new file mode 100644
index 0000000000..8ced56e75a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/drop_order.rs
@@ -0,0 +1,162 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+// Refs: https://doc.rust-lang.org/reference/destructors.html
+
+use std::{cell::Cell, pin::Pin, thread};
+
+use pin_project::pin_project;
+
+struct D<'a>(&'a Cell<usize>, usize);
+
+impl Drop for D<'_> {
+    fn drop(&mut self) {
+        if !thread::panicking() {
+            let old = self.0.replace(self.1);
+            assert_eq!(old, self.1 - 1);
+        }
+    }
+}
+
+#[pin_project(project_replace)]
+struct StructPinned<'a> {
+    #[pin]
+    f1: D<'a>,
+    #[pin]
+    f2: D<'a>,
+}
+
+#[pin_project(project_replace)]
+struct StructUnpinned<'a> {
+    f1: D<'a>,
+    f2: D<'a>,
+}
+
+#[pin_project(project_replace)]
+struct TuplePinned<'a>(#[pin] D<'a>, #[pin] D<'a>);
+
+#[pin_project(project_replace)]
+struct TupleUnpinned<'a>(D<'a>, D<'a>);
+
+#[pin_project(project_replace = EnumProj)]
+enum Enum<'a> {
+    #[allow(dead_code)] // false positive that fixed in Rust 1.38
+    StructPinned {
+        #[pin]
+        f1: D<'a>,
+        #[pin]
+        f2: D<'a>,
+    },
+    #[allow(dead_code)] // false positive that fixed in Rust 1.38
+    StructUnpinned {
+        f1: D<'a>,
+        f2: D<'a>,
+    },
+    TuplePinned(#[pin] D<'a>, #[pin] D<'a>),
+    TupleUnpinned(D<'a>, D<'a>),
+}
+
+#[test]
+fn struct_pinned() {
+    {
+        let c = Cell::new(0);
+        let _x = StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(StructPinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+#[test]
+fn struct_unpinned() {
+    {
+        let c = Cell::new(0);
+        let _x = StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(StructUnpinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+#[test]
+fn tuple_pinned() {
+    {
+        let c = Cell::new(0);
+        let _x = TuplePinned(D(&c, 1), D(&c, 2));
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = TuplePinned(D(&c, 1), D(&c, 2));
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(TuplePinned(D(&c, 3), D(&c, 4)));
+    }
+}
+
+#[test]
+fn tuple_unpinned() {
+    {
+        let c = Cell::new(0);
+        let _x = TupleUnpinned(D(&c, 1), D(&c, 2));
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = TupleUnpinned(D(&c, 1), D(&c, 2));
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(TupleUnpinned(D(&c, 3), D(&c, 4)));
+    }
+}
+
+#[test]
+fn enum_struct() {
+    {
+        let c = Cell::new(0);
+        let _x = Enum::StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::StructPinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::StructPinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+
+    {
+        let c = Cell::new(0);
+        let _x = Enum::StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::StructUnpinned { f1: D(&c, 1), f2: D(&c, 2) };
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::StructUnpinned { f1: D(&c, 3), f2: D(&c, 4) });
+    }
+}
+
+#[test]
+fn enum_tuple() {
+    {
+        let c = Cell::new(0);
+        let _x = Enum::TuplePinned(D(&c, 1), D(&c, 2));
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::TuplePinned(D(&c, 1), D(&c, 2));
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::TuplePinned(D(&c, 3), D(&c, 4)));
+    }
+
+    {
+        let c = Cell::new(0);
+        let _x = Enum::TupleUnpinned(D(&c, 1), D(&c, 2));
+    }
+    {
+        let c = Cell::new(0);
+        let mut x = Enum::TupleUnpinned(D(&c, 1), D(&c, 2));
+        let y = Pin::new(&mut x);
+        let _z = y.project_replace(Enum::TupleUnpinned(D(&c, 3), D(&c, 4)));
+    }
+}
diff --git a/third_party/rust/pin-project/tests/expand/default/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/default/enum.expanded.rs
new file mode 100644
index 0000000000..490bf2e453
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/enum.expanded.rs
@@ -0,0 +1,145 @@
+use pin_project::pin_project;
+#[pin(__private(project = EnumProj, project_ref = EnumProjRef))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/default/enum.rs b/third_party/rust/pin-project/tests/expand/default/enum.rs
new file mode 100644
index 0000000000..ff056150ad
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/enum.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project = EnumProj, project_ref = EnumProjRef)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/default/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/default/struct.expanded.rs
new file mode 100644
index 0000000000..0005d863c4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/struct.expanded.rs
@@ -0,0 +1,104 @@
+use pin_project::pin_project;
+#[pin(__private())]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/default/struct.rs b/third_party/rust/pin-project/tests/expand/default/struct.rs
new file mode 100644
index 0000000000..474f0a1161
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/struct.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/default/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/default/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..1c5e3b08be
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/tuple_struct.expanded.rs
@@ -0,0 +1,98 @@
+use pin_project::pin_project;
+#[pin(__private())]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/default/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/default/tuple_struct.rs
new file mode 100644
index 0000000000..398b14f3a5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/default/tuple_struct.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/multifields/enum.expanded.rs
new file mode 100644
index 0000000000..8223de3418
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/enum.expanded.rs
@@ -0,0 +1,268 @@
+use pin_project::pin_project;
+#[pin(
+    __private(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn
+    )
+)]
+enum Enum<T, U> {
+    Struct { #[pin] pinned1: T, #[pin] pinned2: T, unpinned1: U, unpinned2: U },
+    Tuple(#[pin] T, #[pin] T, U, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned1: ::pin_project::__private::Pin<&'pin mut (T)>,
+        pinned2: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned1: &'pin mut (U),
+        unpinned2: &'pin mut (U),
+    },
+    Tuple(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+        &'pin mut (U),
+    ),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned1: ::pin_project::__private::Pin<&'pin (T)>,
+        pinned2: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned1: &'pin (U),
+        unpinned2: &'pin (U),
+    },
+    Tuple(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+        &'pin (U),
+    ),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(variant_size_differences)]
+#[allow(clippy::large_enum_variant)]
+enum EnumProjOwn<T, U> {
+    Struct {
+        pinned1: ::pin_project::__private::PhantomData<T>,
+        pinned2: ::pin_project::__private::PhantomData<T>,
+        unpinned1: U,
+        unpinned2: U,
+    },
+    Tuple(
+        ::pin_project::__private::PhantomData<T>,
+        ::pin_project::__private::PhantomData<T>,
+        U,
+        U,
+    ),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned1, pinned2, unpinned1, unpinned2 } => {
+                        EnumProj::Struct {
+                            pinned1: _pin_project::__private::Pin::new_unchecked(
+                                pinned1,
+                            ),
+                            pinned2: _pin_project::__private::Pin::new_unchecked(
+                                pinned2,
+                            ),
+                            unpinned1,
+                            unpinned2,
+                        }
+                    }
+                    Self::Tuple(_0, _1, _2, _3) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _pin_project::__private::Pin::new_unchecked(_1),
+                            _2,
+                            _3,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned1, pinned2, unpinned1, unpinned2 } => {
+                        EnumProjRef::Struct {
+                            pinned1: _pin_project::__private::Pin::new_unchecked(
+                                pinned1,
+                            ),
+                            pinned2: _pin_project::__private::Pin::new_unchecked(
+                                pinned2,
+                            ),
+                            unpinned1,
+                            unpinned2,
+                        }
+                    }
+                    Self::Tuple(_0, _1, _2, _3) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _pin_project::__private::Pin::new_unchecked(_1),
+                            _2,
+                            _3,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> EnumProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned1, pinned2, unpinned1, unpinned2 } => {
+                        let __result = EnumProjOwn::Struct {
+                            pinned1: _pin_project::__private::PhantomData,
+                            pinned2: _pin_project::__private::PhantomData,
+                            unpinned1: _pin_project::__private::ptr::read(unpinned1),
+                            unpinned2: _pin_project::__private::ptr::read(unpinned2),
+                        };
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                pinned2,
+                            );
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                pinned1,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Tuple(_0, _1, _2, _3) => {
+                        let __result = EnumProjOwn::Tuple(
+                            _pin_project::__private::PhantomData,
+                            _pin_project::__private::PhantomData,
+                            _pin_project::__private::ptr::read(_2),
+                            _pin_project::__private::ptr::read(_3),
+                        );
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                _1,
+                            );
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                _0,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Unit => {
+                        let __result = EnumProjOwn::Unit;
+                        {}
+                        __result
+                    }
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+        __field2: T,
+        __field3: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/enum.rs b/third_party/rust/pin-project/tests/expand/multifields/enum.rs
new file mode 100644
index 0000000000..754d48c9f9
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/enum.rs
@@ -0,0 +1,17 @@
+use pin_project::pin_project;
+
+#[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned1: T,
+        #[pin]
+        pinned2: T,
+        unpinned1: U,
+        unpinned2: U,
+    },
+    Tuple(#[pin] T, #[pin] T, U, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/multifields/struct.expanded.rs
new file mode 100644
index 0000000000..df8dc92575
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/struct.expanded.rs
@@ -0,0 +1,155 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace))]
+struct Struct<T, U> {
+    #[pin]
+    pinned1: T,
+    #[pin]
+    pinned2: T,
+    unpinned1: U,
+    unpinned2: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned1: ::pin_project::__private::Pin<&'pin mut (T)>,
+        pinned2: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned1: &'pin mut (U),
+        unpinned2: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned1: ::pin_project::__private::Pin<&'pin (T)>,
+        pinned2: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned1: &'pin (U),
+        unpinned2: &'pin (U),
+    }
+    #[allow(dead_code)]
+    struct __StructProjectionOwned<T, U> {
+        pinned1: ::pin_project::__private::PhantomData<T>,
+        pinned2: ::pin_project::__private::PhantomData<T>,
+        unpinned1: U,
+        unpinned2: U,
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned1, pinned2, unpinned1, unpinned2 } = self
+                    .get_unchecked_mut();
+                __StructProjection {
+                    pinned1: _pin_project::__private::Pin::new_unchecked(pinned1),
+                    pinned2: _pin_project::__private::Pin::new_unchecked(pinned2),
+                    unpinned1,
+                    unpinned2,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned1, pinned2, unpinned1, unpinned2 } = self.get_ref();
+                __StructProjectionRef {
+                    pinned1: _pin_project::__private::Pin::new_unchecked(pinned1),
+                    pinned2: _pin_project::__private::Pin::new_unchecked(pinned2),
+                    unpinned1,
+                    unpinned2,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> __StructProjectionOwned<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self { pinned1, pinned2, unpinned1, unpinned2 } = &mut *__self_ptr;
+                let __result = __StructProjectionOwned {
+                    pinned1: _pin_project::__private::PhantomData,
+                    pinned2: _pin_project::__private::PhantomData,
+                    unpinned1: _pin_project::__private::ptr::read(unpinned1),
+                    unpinned2: _pin_project::__private::ptr::read(unpinned2),
+                };
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        pinned2,
+                    );
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        pinned1,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned1;
+        let _ = &this.pinned2;
+        let _ = &this.unpinned1;
+        let _ = &this.unpinned2;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/struct.rs b/third_party/rust/pin-project/tests/expand/multifields/struct.rs
new file mode 100644
index 0000000000..3b319bf813
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/struct.rs
@@ -0,0 +1,13 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace)]
+struct Struct<T, U> {
+    #[pin]
+    pinned1: T,
+    #[pin]
+    pinned2: T,
+    unpinned1: U,
+    unpinned2: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..0c85f9a605
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.expanded.rs
@@ -0,0 +1,145 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace))]
+struct TupleStruct<T, U>(#[pin] T, #[pin] T, U, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    struct __TupleStructProjectionOwned<T, U>(
+        ::pin_project::__private::PhantomData<T>,
+        ::pin_project::__private::PhantomData<T>,
+        U,
+        U,
+    );
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1, _2, _3) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _pin_project::__private::Pin::new_unchecked(_1),
+                    _2,
+                    _3,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1, _2, _3) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _pin_project::__private::Pin::new_unchecked(_1),
+                    _2,
+                    _3,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> __TupleStructProjectionOwned<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self(_0, _1, _2, _3) = &mut *__self_ptr;
+                let __result = __TupleStructProjectionOwned(
+                    _pin_project::__private::PhantomData,
+                    _pin_project::__private::PhantomData,
+                    _pin_project::__private::ptr::read(_2),
+                    _pin_project::__private::ptr::read(_3),
+                );
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        _1,
+                    );
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        _0,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+        let _ = &this.2;
+        let _ = &this.3;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.rs
new file mode 100644
index 0000000000..bc92eee52c
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/multifields/tuple_struct.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace)]
+struct TupleStruct<T, U>(#[pin] T, #[pin] T, U, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-all.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/enum-all.expanded.rs
new file mode 100644
index 0000000000..8dbe768ef3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-all.expanded.rs
@@ -0,0 +1,204 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj, project_ref = ProjRef, project_replace = ProjOwn))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum Proj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum ProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(variant_size_differences)]
+#[allow(clippy::large_enum_variant)]
+enum ProjOwn<T, U> {
+    Struct { pinned: ::pin_project::__private::PhantomData<T>, unpinned: U },
+    Tuple(::pin_project::__private::PhantomData<T>, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        Proj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        Proj::Tuple(_pin_project::__private::Pin::new_unchecked(_0), _1)
+                    }
+                    Self::Unit => Proj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        ProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        ProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => ProjRef::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned, unpinned } => {
+                        let __result = ProjOwn::Struct {
+                            pinned: _pin_project::__private::PhantomData,
+                            unpinned: _pin_project::__private::ptr::read(unpinned),
+                        };
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                pinned,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Tuple(_0, _1) => {
+                        let __result = ProjOwn::Tuple(
+                            _pin_project::__private::PhantomData,
+                            _pin_project::__private::ptr::read(_1),
+                        );
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                _0,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Unit => {
+                        let __result = ProjOwn::Unit;
+                        {}
+                        __result
+                    }
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-all.rs b/third_party/rust/pin-project/tests/expand/naming/enum-all.rs
new file mode 100644
index 0000000000..dd513e6c36
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-all.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj, project_ref = ProjRef, project_replace = ProjOwn)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-mut.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/enum-mut.expanded.rs
new file mode 100644
index 0000000000..c6916ece85
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-mut.expanded.rs
@@ -0,0 +1,99 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum Proj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        Proj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        Proj::Tuple(_pin_project::__private::Pin::new_unchecked(_0), _1)
+                    }
+                    Self::Unit => Proj::Unit,
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-mut.rs b/third_party/rust/pin-project/tests/expand/naming/enum-mut.rs
new file mode 100644
index 0000000000..818276f39c
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-mut.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-none.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/enum-none.expanded.rs
new file mode 100644
index 0000000000..46477d1e9d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-none.expanded.rs
@@ -0,0 +1,56 @@
+use pin_project::pin_project;
+#[pin(__private())]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {}
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-none.rs b/third_party/rust/pin-project/tests/expand/naming/enum-none.rs
new file mode 100644
index 0000000000..a87438db38
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-none.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-own.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/enum-own.expanded.rs
new file mode 100644
index 0000000000..ddeb00c4b5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-own.expanded.rs
@@ -0,0 +1,119 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace = ProjOwn))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(variant_size_differences)]
+#[allow(clippy::large_enum_variant)]
+enum ProjOwn<T, U> {
+    Struct { pinned: ::pin_project::__private::PhantomData<T>, unpinned: U },
+    Tuple(::pin_project::__private::PhantomData<T>, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned, unpinned } => {
+                        let __result = ProjOwn::Struct {
+                            pinned: _pin_project::__private::PhantomData,
+                            unpinned: _pin_project::__private::ptr::read(unpinned),
+                        };
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                pinned,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Tuple(_0, _1) => {
+                        let __result = ProjOwn::Tuple(
+                            _pin_project::__private::PhantomData,
+                            _pin_project::__private::ptr::read(_1),
+                        );
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                _0,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Unit => {
+                        let __result = ProjOwn::Unit;
+                        {}
+                        __result
+                    }
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-own.rs b/third_party/rust/pin-project/tests/expand/naming/enum-own.rs
new file mode 100644
index 0000000000..cf886974db
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-own.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace = ProjOwn)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-ref.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/enum-ref.expanded.rs
new file mode 100644
index 0000000000..1a49584e75
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-ref.expanded.rs
@@ -0,0 +1,100 @@
+use pin_project::pin_project;
+#[pin(__private(project_ref = ProjRef))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum ProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        ProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        ProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => ProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/enum-ref.rs b/third_party/rust/pin-project/tests/expand/naming/enum-ref.rs
new file mode 100644
index 0000000000..b1ff805ce5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/enum-ref.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project_ref = ProjRef)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-all.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/struct-all.expanded.rs
new file mode 100644
index 0000000000..e598a4f354
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-all.expanded.rs
@@ -0,0 +1,163 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj, project_ref = ProjRef, project_replace = ProjOwn))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+struct Proj<'pin, T, U>
+where
+    Struct<T, U>: 'pin,
+{
+    pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+    unpinned: &'pin mut (U),
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+struct ProjRef<'pin, T, U>
+where
+    Struct<T, U>: 'pin,
+{
+    pinned: ::pin_project::__private::Pin<&'pin (T)>,
+    unpinned: &'pin (U),
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+struct ProjOwn<T, U> {
+    pinned: ::pin_project::__private::PhantomData<T>,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Proj {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self { pinned, unpinned } = &mut *__self_ptr;
+                let __result = ProjOwn {
+                    pinned: _pin_project::__private::PhantomData,
+                    unpinned: _pin_project::__private::ptr::read(unpinned),
+                };
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        pinned,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-all.rs b/third_party/rust/pin-project/tests/expand/naming/struct-all.rs
new file mode 100644
index 0000000000..c229ba4e0e
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-all.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj, project_ref = ProjRef, project_replace = ProjOwn)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-mut.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/struct-mut.expanded.rs
new file mode 100644
index 0000000000..88782ee253
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-mut.expanded.rs
@@ -0,0 +1,114 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+struct Proj<'pin, T, U>
+where
+    Struct<T, U>: 'pin,
+{
+    pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+    unpinned: &'pin mut (U),
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                Proj {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-mut.rs b/third_party/rust/pin-project/tests/expand/naming/struct-mut.rs
new file mode 100644
index 0000000000..2f554d324d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-mut.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-none.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/struct-none.expanded.rs
new file mode 100644
index 0000000000..0005d863c4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-none.expanded.rs
@@ -0,0 +1,104 @@
+use pin_project::pin_project;
+#[pin(__private())]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-none.rs b/third_party/rust/pin-project/tests/expand/naming/struct-none.rs
new file mode 100644
index 0000000000..474f0a1161
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-none.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-own.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/struct-own.expanded.rs
new file mode 100644
index 0000000000..cc248628a9
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-own.expanded.rs
@@ -0,0 +1,143 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace = ProjOwn))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+struct ProjOwn<T, U> {
+    pinned: ::pin_project::__private::PhantomData<T>,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self { pinned, unpinned } = &mut *__self_ptr;
+                let __result = ProjOwn {
+                    pinned: _pin_project::__private::PhantomData,
+                    unpinned: _pin_project::__private::ptr::read(unpinned),
+                };
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        pinned,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-own.rs b/third_party/rust/pin-project/tests/expand/naming/struct-own.rs
new file mode 100644
index 0000000000..4924362ba0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-own.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace = ProjOwn)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-ref.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/struct-ref.expanded.rs
new file mode 100644
index 0000000000..e392f6f9c3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-ref.expanded.rs
@@ -0,0 +1,114 @@
+use pin_project::pin_project;
+#[pin(__private(project_ref = ProjRef))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+struct ProjRef<'pin, T, U>
+where
+    Struct<T, U>: 'pin,
+{
+    pinned: ::pin_project::__private::Pin<&'pin (T)>,
+    unpinned: &'pin (U),
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                ProjRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/struct-ref.rs b/third_party/rust/pin-project/tests/expand/naming/struct-ref.rs
new file mode 100644
index 0000000000..4e29a162d4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/struct-ref.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(project_ref = ProjRef)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.expanded.rs
new file mode 100644
index 0000000000..8c148ed95b
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.expanded.rs
@@ -0,0 +1,148 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj, project_ref = ProjRef, project_replace = ProjOwn))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+struct Proj<'pin, T, U>(
+    ::pin_project::__private::Pin<&'pin mut (T)>,
+    &'pin mut (U),
+)
+where
+    TupleStruct<T, U>: 'pin;
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+struct ProjRef<'pin, T, U>(
+    ::pin_project::__private::Pin<&'pin (T)>,
+    &'pin (U),
+)
+where
+    TupleStruct<T, U>: 'pin;
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+struct ProjOwn<T, U>(::pin_project::__private::PhantomData<T>, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                Proj(_pin_project::__private::Pin::new_unchecked(_0), _1)
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                ProjRef(_pin_project::__private::Pin::new_unchecked(_0), _1)
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self(_0, _1) = &mut *__self_ptr;
+                let __result = ProjOwn(
+                    _pin_project::__private::PhantomData,
+                    _pin_project::__private::ptr::read(_1),
+                );
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        _0,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.rs
new file mode 100644
index 0000000000..0d95cb0080
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-all.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj, project_ref = ProjRef, project_replace = ProjOwn)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.expanded.rs
new file mode 100644
index 0000000000..79c790100d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.expanded.rs
@@ -0,0 +1,105 @@
+use pin_project::pin_project;
+#[pin(__private(project = Proj))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+struct Proj<'pin, T, U>(
+    ::pin_project::__private::Pin<&'pin mut (T)>,
+    &'pin mut (U),
+)
+where
+    TupleStruct<T, U>: 'pin;
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> Proj<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                Proj(_pin_project::__private::Pin::new_unchecked(_0), _1)
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.rs
new file mode 100644
index 0000000000..e9779a6cad
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-mut.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project = Proj)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.expanded.rs
new file mode 100644
index 0000000000..1c5e3b08be
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.expanded.rs
@@ -0,0 +1,98 @@
+use pin_project::pin_project;
+#[pin(__private())]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.rs
new file mode 100644
index 0000000000..398b14f3a5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-none.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.expanded.rs
new file mode 100644
index 0000000000..37e4c34373
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.expanded.rs
@@ -0,0 +1,134 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace = ProjOwn))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+struct ProjOwn<T, U>(::pin_project::__private::PhantomData<T>, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> ProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self(_0, _1) = &mut *__self_ptr;
+                let __result = ProjOwn(
+                    _pin_project::__private::PhantomData,
+                    _pin_project::__private::ptr::read(_1),
+                );
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        _0,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.rs
new file mode 100644
index 0000000000..a15ad4094a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-own.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace = ProjOwn)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.expanded.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.expanded.rs
new file mode 100644
index 0000000000..8c8686808c
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.expanded.rs
@@ -0,0 +1,105 @@
+use pin_project::pin_project;
+#[pin(__private(project_ref = ProjRef))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+struct ProjRef<'pin, T, U>(
+    ::pin_project::__private::Pin<&'pin (T)>,
+    &'pin (U),
+)
+where
+    TupleStruct<T, U>: 'pin;
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> ProjRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                ProjRef(_pin_project::__private::Pin::new_unchecked(_0), _1)
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.rs b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.rs
new file mode 100644
index 0000000000..cc61edfb79
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/naming/tuple_struct-ref.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project_ref = ProjRef)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/not_unpin/enum.expanded.rs
new file mode 100644
index 0000000000..98e7bbe16d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/enum.expanded.rs
@@ -0,0 +1,139 @@
+use pin_project::pin_project;
+#[pin(__private(!Unpin, project = EnumProj, project_ref = EnumProjRef))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/enum.rs b/third_party/rust/pin-project/tests/expand/not_unpin/enum.rs
new file mode 100644
index 0000000000..ac0b3b80c0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/enum.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(!Unpin, project = EnumProj, project_ref = EnumProjRef)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/not_unpin/struct.expanded.rs
new file mode 100644
index 0000000000..420f21aaaf
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/struct.expanded.rs
@@ -0,0 +1,99 @@
+use pin_project::pin_project;
+#[pin(__private(!Unpin))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/struct.rs b/third_party/rust/pin-project/tests/expand/not_unpin/struct.rs
new file mode 100644
index 0000000000..233e6d41f8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/struct.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(!Unpin)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..99621f496d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.expanded.rs
@@ -0,0 +1,93 @@
+use pin_project::pin_project;
+#[pin(__private(!Unpin))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        _pin_project::__private::Wrapper<
+            'pin,
+            _pin_project::__private::PhantomPinned,
+        >: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.rs
new file mode 100644
index 0000000000..c8065db6ad
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/not_unpin/tuple_struct.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(!Unpin)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/enum.expanded.rs
new file mode 100644
index 0000000000..1a8e746127
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/enum.expanded.rs
@@ -0,0 +1,157 @@
+use std::pin::Pin;
+use pin_project::{pin_project, pinned_drop};
+#[pin(__private(PinnedDrop, project = EnumProj, project_ref = EnumProjRef))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    impl<T, U> _pin_project::__private::Drop for Enum<T, U> {
+        fn drop(&mut self) {
+            unsafe {
+                let __pinned_self = _pin_project::__private::Pin::new_unchecked(self);
+                _pin_project::__private::PinnedDrop::drop(__pinned_self);
+            }
+        }
+    }
+};
+#[doc(hidden)]
+impl<T, U> ::pin_project::__private::PinnedDrop for Enum<T, U> {
+    unsafe fn drop(self: Pin<&mut Self>) {
+        #[allow(clippy::needless_pass_by_value)]
+        fn __drop_inner<T, U>(__self: Pin<&mut Enum<T, U>>) {
+            fn __drop_inner() {}
+            let _ = __self;
+        }
+        __drop_inner(self);
+    }
+}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/enum.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/enum.rs
new file mode 100644
index 0000000000..c162ef6b2b
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/enum.rs
@@ -0,0 +1,23 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop, project = EnumProj, project_ref = EnumProjRef)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+#[pinned_drop]
+impl<T, U> PinnedDrop for Enum<T, U> {
+    fn drop(self: Pin<&mut Self>) {
+        let _ = self;
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/struct.expanded.rs
new file mode 100644
index 0000000000..d21440d347
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/struct.expanded.rs
@@ -0,0 +1,116 @@
+use std::pin::Pin;
+use pin_project::{pin_project, pinned_drop};
+#[pin(__private(PinnedDrop))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    impl<T, U> _pin_project::__private::Drop for Struct<T, U> {
+        fn drop(&mut self) {
+            unsafe {
+                let __pinned_self = _pin_project::__private::Pin::new_unchecked(self);
+                _pin_project::__private::PinnedDrop::drop(__pinned_self);
+            }
+        }
+    }
+};
+#[doc(hidden)]
+impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+    unsafe fn drop(self: Pin<&mut Self>) {
+        #[allow(clippy::needless_pass_by_value)]
+        fn __drop_inner<T, U>(__self: Pin<&mut Struct<T, U>>) {
+            fn __drop_inner() {}
+            let _ = __self;
+        }
+        __drop_inner(self);
+    }
+}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/struct.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/struct.rs
new file mode 100644
index 0000000000..691d3cb4a0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/struct.rs
@@ -0,0 +1,19 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+#[pinned_drop]
+impl<T, U> PinnedDrop for Struct<T, U> {
+    fn drop(self: Pin<&mut Self>) {
+        let _ = self;
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..9a614ae551
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.expanded.rs
@@ -0,0 +1,110 @@
+use std::pin::Pin;
+use pin_project::{pin_project, pinned_drop};
+#[pin(__private(PinnedDrop))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    impl<T, U> _pin_project::__private::Drop for TupleStruct<T, U> {
+        fn drop(&mut self) {
+            unsafe {
+                let __pinned_self = _pin_project::__private::Pin::new_unchecked(self);
+                _pin_project::__private::PinnedDrop::drop(__pinned_self);
+            }
+        }
+    }
+};
+#[doc(hidden)]
+impl<T, U> ::pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+    unsafe fn drop(self: Pin<&mut Self>) {
+        #[allow(clippy::needless_pass_by_value)]
+        fn __drop_inner<T, U>(__self: Pin<&mut TupleStruct<T, U>>) {
+            fn __drop_inner() {}
+            let _ = __self;
+        }
+        __drop_inner(self);
+    }
+}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.rs
new file mode 100644
index 0000000000..1f4917c221
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pinned_drop/tuple_struct.rs
@@ -0,0 +1,15 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+#[pinned_drop]
+impl<T, U> PinnedDrop for TupleStruct<T, U> {
+    fn drop(self: Pin<&mut Self>) {
+        let _ = self;
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/project_replace/enum.expanded.rs
new file mode 100644
index 0000000000..178cb99758
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/enum.expanded.rs
@@ -0,0 +1,119 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace = EnumProjOwn))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(variant_size_differences)]
+#[allow(clippy::large_enum_variant)]
+enum EnumProjOwn<T, U> {
+    Struct { pinned: ::pin_project::__private::PhantomData<T>, unpinned: U },
+    Tuple(::pin_project::__private::PhantomData<T>, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> EnumProjOwn<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                match &mut *__self_ptr {
+                    Self::Struct { pinned, unpinned } => {
+                        let __result = EnumProjOwn::Struct {
+                            pinned: _pin_project::__private::PhantomData,
+                            unpinned: _pin_project::__private::ptr::read(unpinned),
+                        };
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                pinned,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Tuple(_0, _1) => {
+                        let __result = EnumProjOwn::Tuple(
+                            _pin_project::__private::PhantomData,
+                            _pin_project::__private::ptr::read(_1),
+                        );
+                        {
+                            let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                                _0,
+                            );
+                        }
+                        __result
+                    }
+                    Self::Unit => {
+                        let __result = EnumProjOwn::Unit;
+                        {}
+                        __result
+                    }
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/enum.rs b/third_party/rust/pin-project/tests/expand/project_replace/enum.rs
new file mode 100644
index 0000000000..d737f649bf
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/enum.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace = EnumProjOwn)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/project_replace/struct.expanded.rs
new file mode 100644
index 0000000000..45839a2857
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/struct.expanded.rs
@@ -0,0 +1,133 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    #[allow(dead_code)]
+    struct __StructProjectionOwned<T, U> {
+        pinned: ::pin_project::__private::PhantomData<T>,
+        unpinned: U,
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> __StructProjectionOwned<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self { pinned, unpinned } = &mut *__self_ptr;
+                let __result = __StructProjectionOwned {
+                    pinned: _pin_project::__private::PhantomData,
+                    unpinned: _pin_project::__private::ptr::read(unpinned),
+                };
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        pinned,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/struct.rs b/third_party/rust/pin-project/tests/expand/project_replace/struct.rs
new file mode 100644
index 0000000000..5865526a58
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/struct.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..cdee3d149e
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.expanded.rs
@@ -0,0 +1,127 @@
+use pin_project::pin_project;
+#[pin(__private(project_replace))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    struct __TupleStructProjectionOwned<T, U>(
+        ::pin_project::__private::PhantomData<T>,
+        U,
+    );
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        fn project_replace(
+            self: _pin_project::__private::Pin<&mut Self>,
+            __replacement: Self,
+        ) -> __TupleStructProjectionOwned<T, U> {
+            unsafe {
+                let __self_ptr: *mut Self = self.get_unchecked_mut();
+                let __guard = _pin_project::__private::UnsafeOverwriteGuard::new(
+                    __self_ptr,
+                    __replacement,
+                );
+                let Self(_0, _1) = &mut *__self_ptr;
+                let __result = __TupleStructProjectionOwned(
+                    _pin_project::__private::PhantomData,
+                    _pin_project::__private::ptr::read(_1),
+                );
+                {
+                    let __guard = _pin_project::__private::UnsafeDropInPlaceGuard::new(
+                        _0,
+                    );
+                }
+                __result
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.rs
new file mode 100644
index 0000000000..c4d05f5faa
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/project_replace/tuple_struct.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/pub/enum.expanded.rs
new file mode 100644
index 0000000000..90be268005
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/enum.expanded.rs
@@ -0,0 +1,145 @@
+use pin_project::pin_project;
+#[pin(__private(project = EnumProj, project_ref = EnumProjRef))]
+pub enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+pub(crate) enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+pub(crate) enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        pub(crate) fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        pub(crate) fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    #[allow(missing_debug_implementations)]
+    pub struct __Enum<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+        __field1: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Enum<T, U>
+    where
+        __Enum<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/enum.rs b/third_party/rust/pin-project/tests/expand/pub/enum.rs
new file mode 100644
index 0000000000..7c8577fd1b
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/enum.rs
@@ -0,0 +1,14 @@
+use pin_project::pin_project;
+
+#[pin_project(project = EnumProj, project_ref = EnumProjRef)]
+pub enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/pub/struct.expanded.rs
new file mode 100644
index 0000000000..ca31f3d768
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/struct.expanded.rs
@@ -0,0 +1,104 @@
+use pin_project::pin_project;
+#[pin(__private())]
+pub struct Struct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    pub(crate) struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pub pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        pub unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    pub(crate) struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pub pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        pub unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        pub(crate) fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        pub(crate) fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    #[allow(missing_debug_implementations)]
+    pub struct __Struct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for Struct<T, U>
+    where
+        __Struct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/struct.rs b/third_party/rust/pin-project/tests/expand/pub/struct.rs
new file mode 100644
index 0000000000..f50d1e9272
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/struct.rs
@@ -0,0 +1,10 @@
+use pin_project::pin_project;
+
+#[pin_project]
+pub struct Struct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/pub/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..5c7efbf23d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/tuple_struct.expanded.rs
@@ -0,0 +1,98 @@
+use pin_project::pin_project;
+#[pin(__private())]
+pub struct TupleStruct<T, U>(#[pin] pub T, pub U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    pub(crate) struct __TupleStructProjection<'pin, T, U>(
+        pub ::pin_project::__private::Pin<&'pin mut (T)>,
+        pub &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    pub(crate) struct __TupleStructProjectionRef<'pin, T, U>(
+        pub ::pin_project::__private::Pin<&'pin (T)>,
+        pub &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        pub(crate) fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        pub(crate) fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    #[allow(missing_debug_implementations)]
+    pub struct __TupleStruct<'pin, T, U> {
+        __pin_project_use_generics: _pin_project::__private::AlwaysUnpin<
+            'pin,
+            (
+                _pin_project::__private::PhantomData<T>,
+                _pin_project::__private::PhantomData<U>,
+            ),
+        >,
+        __field0: T,
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    #[doc(hidden)]
+    unsafe impl<'pin, T, U> _pin_project::UnsafeUnpin for TupleStruct<T, U>
+    where
+        __TupleStruct<'pin, T, U>: _pin_project::__private::Unpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/pub/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/pub/tuple_struct.rs
new file mode 100644
index 0000000000..5756aafcc8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/pub/tuple_struct.rs
@@ -0,0 +1,6 @@
+use pin_project::pin_project;
+
+#[pin_project]
+pub struct TupleStruct<T, U>(#[pin] pub T, pub U);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.expanded.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.expanded.rs
new file mode 100644
index 0000000000..1f88cccae6
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.expanded.rs
@@ -0,0 +1,129 @@
+use pin_project::{pin_project, UnsafeUnpin};
+#[pin(__private(UnsafeUnpin, project = EnumProj, project_ref = EnumProjRef))]
+enum Enum<T, U> {
+    Struct { #[pin] pinned: T, unpinned: U },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::mut_mut)]
+enum EnumProj<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    },
+    Tuple(::pin_project::__private::Pin<&'pin mut (T)>, &'pin mut (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(dead_code)]
+#[allow(clippy::ref_option_ref)]
+enum EnumProjRef<'pin, T, U>
+where
+    Enum<T, U>: 'pin,
+{
+    Struct { pinned: ::pin_project::__private::Pin<&'pin (T)>, unpinned: &'pin (U) },
+    Tuple(::pin_project::__private::Pin<&'pin (T)>, &'pin (U)),
+    Unit,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    impl<T, U> Enum<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> EnumProj<'pin, T, U> {
+            unsafe {
+                match self.get_unchecked_mut() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProj::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProj::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProj::Unit,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> EnumProjRef<'pin, T, U> {
+            unsafe {
+                match self.get_ref() {
+                    Self::Struct { pinned, unpinned } => {
+                        EnumProjRef::Struct {
+                            pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                            unpinned,
+                        }
+                    }
+                    Self::Tuple(_0, _1) => {
+                        EnumProjRef::Tuple(
+                            _pin_project::__private::Pin::new_unchecked(_0),
+                            _1,
+                        )
+                    }
+                    Self::Unit => EnumProjRef::Unit,
+                }
+            }
+        }
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
+    where
+        _pin_project::__private::Wrapper<'pin, Self>: _pin_project::UnsafeUnpin,
+    {}
+    trait EnumMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> EnumMustNotImplDrop for T {}
+    impl<T, U> EnumMustNotImplDrop for Enum<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Enum<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+unsafe impl<T: Unpin, U> UnsafeUnpin for Enum<T, U> {}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.rs
new file mode 100644
index 0000000000..d368d7132b
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/enum.rs
@@ -0,0 +1,16 @@
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(UnsafeUnpin, project = EnumProj, project_ref = EnumProjRef)]
+enum Enum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Enum<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.expanded.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.expanded.rs
new file mode 100644
index 0000000000..5fa7271572
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.expanded.rs
@@ -0,0 +1,89 @@
+use pin_project::{pin_project, UnsafeUnpin};
+#[pin(__private(UnsafeUnpin))]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __StructProjection<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+        unpinned: &'pin mut (U),
+    }
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __StructProjectionRef<'pin, T, U>
+    where
+        Struct<T, U>: 'pin,
+    {
+        pinned: ::pin_project::__private::Pin<&'pin (T)>,
+        unpinned: &'pin (U),
+    }
+    impl<T, U> Struct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __StructProjection<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_unchecked_mut();
+                __StructProjection {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __StructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self { pinned, unpinned } = self.get_ref();
+                __StructProjectionRef {
+                    pinned: _pin_project::__private::Pin::new_unchecked(pinned),
+                    unpinned,
+                }
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+        let _ = &this.pinned;
+        let _ = &this.unpinned;
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
+    where
+        _pin_project::__private::Wrapper<'pin, Self>: _pin_project::UnsafeUnpin,
+    {}
+    trait StructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> StructMustNotImplDrop for T {}
+    impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for Struct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.rs
new file mode 100644
index 0000000000..b0851b1ad6
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/struct.rs
@@ -0,0 +1,12 @@
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(UnsafeUnpin)]
+struct Struct<T, U> {
+    #[pin]
+    pinned: T,
+    unpinned: U,
+}
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.expanded.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.expanded.rs
new file mode 100644
index 0000000000..de4e9269cb
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.expanded.rs
@@ -0,0 +1,83 @@
+use pin_project::{pin_project, UnsafeUnpin};
+#[pin(__private(UnsafeUnpin))]
+struct TupleStruct<T, U>(#[pin] T, U);
+#[allow(box_pointers)]
+#[allow(deprecated)]
+#[allow(explicit_outlives_requirements)]
+#[allow(single_use_lifetimes)]
+#[allow(unreachable_pub)]
+#[allow(unused_tuple_struct_fields)]
+#[allow(clippy::unknown_clippy_lints)]
+#[allow(clippy::pattern_type_mismatch)]
+#[allow(clippy::redundant_pub_crate)]
+#[allow(clippy::type_repetition_in_bounds)]
+#[allow(unused_qualifications)]
+#[allow(clippy::semicolon_if_nothing_returned)]
+#[allow(clippy::use_self)]
+#[allow(clippy::used_underscore_binding)]
+const _: () = {
+    #[allow(unused_extern_crates)]
+    extern crate pin_project as _pin_project;
+    #[allow(dead_code)]
+    #[allow(clippy::mut_mut)]
+    struct __TupleStructProjection<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin mut (T)>,
+        &'pin mut (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    #[allow(dead_code)]
+    #[allow(clippy::ref_option_ref)]
+    struct __TupleStructProjectionRef<'pin, T, U>(
+        ::pin_project::__private::Pin<&'pin (T)>,
+        &'pin (U),
+    )
+    where
+        TupleStruct<T, U>: 'pin;
+    impl<T, U> TupleStruct<T, U> {
+        #[allow(dead_code)]
+        fn project<'pin>(
+            self: _pin_project::__private::Pin<&'pin mut Self>,
+        ) -> __TupleStructProjection<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_unchecked_mut();
+                __TupleStructProjection(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+        #[allow(dead_code)]
+        #[allow(clippy::missing_const_for_fn)]
+        fn project_ref<'pin>(
+            self: _pin_project::__private::Pin<&'pin Self>,
+        ) -> __TupleStructProjectionRef<'pin, T, U> {
+            unsafe {
+                let Self(_0, _1) = self.get_ref();
+                __TupleStructProjectionRef(
+                    _pin_project::__private::Pin::new_unchecked(_0),
+                    _1,
+                )
+            }
+        }
+    }
+    #[forbid(unaligned_references, safe_packed_borrows)]
+    fn __assert_not_repr_packed<T, U>(this: &TupleStruct<T, U>) {
+        let _ = &this.0;
+        let _ = &this.1;
+    }
+    impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
+    where
+        _pin_project::__private::Wrapper<'pin, Self>: _pin_project::UnsafeUnpin,
+    {}
+    trait TupleStructMustNotImplDrop {}
+    #[allow(clippy::drop_bounds, drop_bounds)]
+    impl<T: _pin_project::__private::Drop> TupleStructMustNotImplDrop for T {}
+    impl<T, U> TupleStructMustNotImplDrop for TupleStruct<T, U> {}
+    #[doc(hidden)]
+    impl<T, U> _pin_project::__private::PinnedDrop for TupleStruct<T, U> {
+        unsafe fn drop(self: _pin_project::__private::Pin<&mut Self>) {}
+    }
+};
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.rs b/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.rs
new file mode 100644
index 0000000000..964617a1c9
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expand/unsafe_unpin/tuple_struct.rs
@@ -0,0 +1,8 @@
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(UnsafeUnpin)]
+struct TupleStruct<T, U>(#[pin] T, U);
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/expandtest.rs b/third_party/rust/pin-project/tests/expandtest.rs
new file mode 100644
index 0000000000..4feec1a484
--- /dev/null
+++ b/third_party/rust/pin-project/tests/expandtest.rs
@@ -0,0 +1,43 @@
+#![cfg(not(miri))]
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::{
+    env,
+    process::{Command, ExitStatus, Stdio},
+};
+
+const PATH: &str = "tests/expand/**/*.rs";
+
+#[rustversion::attr(not(nightly), ignore)]
+#[test]
+fn expandtest() {
+    let is_ci = env::var_os("CI").is_some();
+    let cargo = &*env::var("CARGO").unwrap_or_else(|_| "cargo".into());
+    if !has_command(&[cargo, "expand"]) {
+        if is_ci {
+            panic!("expandtest requires cargo-expand");
+        }
+        return;
+    }
+
+    let args = &["--all-features"];
+    if is_ci {
+        macrotest::expand_without_refresh_args(PATH, args);
+    } else {
+        env::set_var("MACROTEST", "overwrite");
+        macrotest::expand_args(PATH, args);
+    }
+}
+
+fn has_command(command: &[&str]) -> bool {
+    Command::new(command[0])
+        .args(&command[1..])
+        .arg("--version")
+        .stdin(Stdio::null())
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .as_ref()
+        .map(ExitStatus::success)
+        .unwrap_or(false)
+}
diff --git a/third_party/rust/pin-project/tests/include/basic-safe-part.rs b/third_party/rust/pin-project/tests/include/basic-safe-part.rs
new file mode 100644
index 0000000000..0b7c43e873
--- /dev/null
+++ b/third_party/rust/pin-project/tests/include/basic-safe-part.rs
@@ -0,0 +1,193 @@
+// default #[pin_project], PinnedDrop, project_replace, !Unpin, and UnsafeUnpin without UnsafeUnpin impl are completely safe.
+
+#[::pin_project::pin_project]
+#[derive(Debug)]
+pub struct DefaultStruct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project(
+    project = DefaultStructNamedProj,
+    project_ref = DefaultStructNamedProjRef,
+)]
+#[derive(Debug)]
+pub struct DefaultStructNamed<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project]
+#[derive(Debug)]
+pub struct DefaultTupleStruct<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    project = DefaultTupleStructNamedProj,
+    project_ref = DefaultTupleStructNamedProjRef,
+)]
+#[derive(Debug)]
+pub struct DefaultTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    project = DefaultEnumProj,
+    project_ref = DefaultEnumProjRef,
+)]
+#[derive(Debug)]
+pub enum DefaultEnum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+#[::pin_project::pin_project(PinnedDrop)]
+#[derive(Debug)]
+pub struct PinnedDropStruct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pinned_drop]
+impl<T, U> PinnedDrop for PinnedDropStruct<T, U> {
+    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+}
+
+#[::pin_project::pin_project(PinnedDrop)]
+#[derive(Debug)]
+pub struct PinnedDropTupleStruct<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pinned_drop]
+impl<T, U> PinnedDrop for PinnedDropTupleStruct<T, U> {
+    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+}
+
+#[::pin_project::pin_project(
+    PinnedDrop,
+    project = PinnedDropEnumProj,
+    project_ref = PinnedDropEnumProjRef,
+)]
+#[derive(Debug)]
+pub enum PinnedDropEnum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+#[::pin_project::pinned_drop]
+impl<T, U> PinnedDrop for PinnedDropEnum<T, U> {
+    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+}
+
+#[::pin_project::pin_project(project_replace)]
+#[derive(Debug)]
+pub struct ReplaceStruct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project(
+    project = ReplaceStructNamedProj,
+    project_ref = ReplaceStructNamedProjRef,
+    project_replace = ReplaceStructNamedProjOwn,
+)]
+#[derive(Debug)]
+pub struct ReplaceStructNamed<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project(project_replace)]
+#[derive(Debug)]
+pub struct ReplaceTupleStruct<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    project = ReplaceTupleStructNamedProj,
+    project_ref = ReplaceTupleStructNamedProjRef,
+    project_replace = ReplaceTupleStructNamedProjOwn,
+)]
+#[derive(Debug)]
+pub struct ReplaceTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    project = ReplaceEnumProj,
+    project_ref = ReplaceEnumProjRef,
+    project_replace = ReplaceEnumProjOwn,
+)]
+#[derive(Debug)]
+pub enum ReplaceEnum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+#[::pin_project::pin_project(UnsafeUnpin)]
+#[derive(Debug)]
+pub struct UnsafeUnpinStruct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project(UnsafeUnpin)]
+#[derive(Debug)]
+pub struct UnsafeUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    UnsafeUnpin,
+    project = UnsafeUnpinEnumProj,
+    project_ref = UnsafeUnpinEnumProjRef,
+)]
+#[derive(Debug)]
+pub enum UnsafeUnpinEnum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
+
+#[::pin_project::pin_project(!Unpin)]
+#[derive(Debug)]
+pub struct NotUnpinStruct<T, U> {
+    #[pin]
+    pub pinned: T,
+    pub unpinned: U,
+}
+
+#[::pin_project::pin_project(!Unpin)]
+#[derive(Debug)]
+pub struct NotUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+#[::pin_project::pin_project(
+    !Unpin,
+    project = NotUnpinEnumProj,
+    project_ref = NotUnpinEnumProjRef,
+)]
+#[derive(Debug)]
+pub enum NotUnpinEnum<T, U> {
+    Struct {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    },
+    Tuple(#[pin] T, U),
+    Unit,
+}
diff --git a/third_party/rust/pin-project/tests/include/basic.rs b/third_party/rust/pin-project/tests/include/basic.rs
new file mode 100644
index 0000000000..57cbaeb86b
--- /dev/null
+++ b/third_party/rust/pin-project/tests/include/basic.rs
@@ -0,0 +1,17 @@
+include!("basic-safe-part.rs");
+
+#[allow(clippy::undocumented_unsafe_blocks)]
+unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+    ::pin_project::UnsafeUnpin for UnsafeUnpinStruct<T, U>
+{
+}
+#[allow(clippy::undocumented_unsafe_blocks)]
+unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+    ::pin_project::UnsafeUnpin for UnsafeUnpinTupleStruct<T, U>
+{
+}
+#[allow(clippy::undocumented_unsafe_blocks)]
+unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+    ::pin_project::UnsafeUnpin for UnsafeUnpinEnum<T, U>
+{
+}
diff --git a/third_party/rust/pin-project/tests/lint.rs b/third_party/rust/pin-project/tests/lint.rs
new file mode 100644
index 0000000000..35f05d50f4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/lint.rs
@@ -0,0 +1,1190 @@
+// Check interoperability with rustc and clippy lints.
+
+// for old compilers
+#![allow(unknown_lints)]
+#![warn(nonstandard_style, rust_2018_idioms, unused)]
+// Note: This does not guarantee compatibility with forbidding these lints in the future.
+// If rustc adds a new lint, we may not be able to keep this.
+#![forbid(future_incompatible, rust_2018_compatibility, rust_2021_compatibility)]
+// lints forbidden as a part of future_incompatible, rust_2018_compatibility, and rust_2021_compatibility are not included in the list below.
+// elided_lifetimes_in_paths, explicit_outlives_requirements, unused_extern_crates:  as a part of rust_2018_idioms
+// unsafe_op_in_unsafe_fn: requires Rust 1.52. and, we don't generate unsafe fn.
+// non_exhaustive_omitted_patterns: unstable
+// unstable_features: no way to generate #![feature(..)] by macros, expect for unstable inner attribute. and this lint is deprecated: https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unstable-features
+// unused_crate_dependencies, must_not_suspend: unrelated
+// unsafe_code: checked in forbid_unsafe module
+#![warn(
+    box_pointers,
+    deprecated_in_future,
+    fuzzy_provenance_casts,
+    lossy_provenance_casts,
+    macro_use_extern_crate,
+    meta_variable_misuse,
+    missing_abi,
+    missing_copy_implementations,
+    missing_debug_implementations,
+    missing_docs,
+    non_ascii_idents,
+    noop_method_call,
+    single_use_lifetimes,
+    trivial_casts,
+    trivial_numeric_casts,
+    unreachable_pub,
+    unused_import_braces,
+    unused_lifetimes,
+    unused_qualifications,
+    unused_results,
+    unused_tuple_struct_fields,
+    variant_size_differences
+)]
+#![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::restriction)]
+#![allow(clippy::blanket_clippy_restriction_lints)] // this is a test, so enable all restriction lints intentionally.
+#![allow(clippy::exhaustive_structs, clippy::exhaustive_enums, clippy::single_char_lifetime_names)] // TODO
+
+pub mod basic {
+    include!("include/basic.rs");
+
+    pub mod inside_macro {
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[::pin_project::pin_project]
+                #[derive(Debug)]
+                pub struct DefaultStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(
+                    project = DefaultStructNamedProj,
+                    project_ref = DefaultStructNamedProjRef,
+                )]
+                #[derive(Debug)]
+                pub struct DefaultStructNamed<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project]
+                #[derive(Debug)]
+                pub struct DefaultTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = DefaultTupleStructNamedProj,
+                    project_ref = DefaultTupleStructNamedProjRef,
+                )]
+                #[derive(Debug)]
+                pub struct DefaultTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = DefaultEnumProj,
+                    project_ref = DefaultEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum DefaultEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(PinnedDrop)]
+                #[derive(Debug)]
+                pub struct PinnedDropStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropStruct<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(PinnedDrop)]
+                #[derive(Debug)]
+                pub struct PinnedDropTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropTupleStruct<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(
+                    PinnedDrop,
+                    project = PinnedDropEnumProj,
+                    project_ref = PinnedDropEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum PinnedDropEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropEnum<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct ReplaceStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(
+                    project = ReplaceStructNamedProj,
+                    project_ref = ReplaceStructNamedProjRef,
+                    project_replace = ReplaceStructNamedProjOwn,
+                )]
+                #[derive(Debug)]
+                pub struct ReplaceStructNamed<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct ReplaceTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = ReplaceTupleStructNamedProj,
+                    project_ref = ReplaceTupleStructNamedProjRef,
+                    project_replace = ReplaceTupleStructNamedProjOwn,
+                )]
+                #[derive(Debug)]
+                pub struct ReplaceTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = ReplaceEnumProj,
+                    project_ref = ReplaceEnumProjRef,
+                    project_replace = ReplaceEnumProjOwn,
+                )]
+                #[derive(Debug)]
+                pub enum ReplaceEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(UnsafeUnpin)]
+                #[derive(Debug)]
+                pub struct UnsafeUnpinStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(UnsafeUnpin)]
+                #[derive(Debug)]
+                pub struct UnsafeUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    UnsafeUnpin,
+                    project = UnsafeUnpinEnumProj,
+                    project_ref = UnsafeUnpinEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum UnsafeUnpinEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(!Unpin)]
+                #[derive(Debug)]
+                pub struct NotUnpinStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(!Unpin)]
+                #[derive(Debug)]
+                pub struct NotUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    !Unpin,
+                    project = NotUnpinEnumProj,
+                    project_ref = NotUnpinEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum NotUnpinEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[allow(clippy::undocumented_unsafe_blocks)]
+                unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+                    ::pin_project::UnsafeUnpin for UnsafeUnpinStruct<T, U>
+                {
+                }
+                #[allow(clippy::undocumented_unsafe_blocks)]
+                unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+                    ::pin_project::UnsafeUnpin for UnsafeUnpinTupleStruct<T, U>
+                {
+                }
+                #[allow(clippy::undocumented_unsafe_blocks)]
+                unsafe impl<T: ::pin_project::__private::Unpin, U: ::pin_project::__private::Unpin>
+                    ::pin_project::UnsafeUnpin for UnsafeUnpinEnum<T, U>
+                {
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod forbid_unsafe {
+    #![forbid(unsafe_code)]
+
+    include!("include/basic-safe-part.rs");
+
+    pub mod inside_macro {
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[::pin_project::pin_project]
+                #[derive(Debug)]
+                pub struct DefaultStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(
+                    project = DefaultStructNamedProj,
+                    project_ref = DefaultStructNamedProjRef,
+                )]
+                #[derive(Debug)]
+                pub struct DefaultStructNamed<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project]
+                #[derive(Debug)]
+                pub struct DefaultTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = DefaultTupleStructNamedProj,
+                    project_ref = DefaultTupleStructNamedProjRef,
+                )]
+                #[derive(Debug)]
+                pub struct DefaultTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = DefaultEnumProj,
+                    project_ref = DefaultEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum DefaultEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(PinnedDrop)]
+                #[derive(Debug)]
+                pub struct PinnedDropStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropStruct<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(PinnedDrop)]
+                #[derive(Debug)]
+                pub struct PinnedDropTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropTupleStruct<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(
+                    PinnedDrop,
+                    project = PinnedDropEnumProj,
+                    project_ref = PinnedDropEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum PinnedDropEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pinned_drop]
+                impl<T, U> PinnedDrop for PinnedDropEnum<T, U> {
+                    fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+                }
+
+                #[::pin_project::pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct ReplaceStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(
+                    project = ReplaceStructNamedProj,
+                    project_ref = ReplaceStructNamedProjRef,
+                    project_replace = ReplaceStructNamedProjOwn,
+                )]
+                #[derive(Debug)]
+                pub struct ReplaceStructNamed<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct ReplaceTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = ReplaceTupleStructNamedProj,
+                    project_ref = ReplaceTupleStructNamedProjRef,
+                    project_replace = ReplaceTupleStructNamedProjOwn,
+                )]
+                #[derive(Debug)]
+                pub struct ReplaceTupleStructNamed<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    project = ReplaceEnumProj,
+                    project_ref = ReplaceEnumProjRef,
+                    project_replace = ReplaceEnumProjOwn,
+                )]
+                #[derive(Debug)]
+                pub enum ReplaceEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(UnsafeUnpin)]
+                #[derive(Debug)]
+                pub struct UnsafeUnpinStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(UnsafeUnpin)]
+                #[derive(Debug)]
+                pub struct UnsafeUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    UnsafeUnpin,
+                    project = UnsafeUnpinEnumProj,
+                    project_ref = UnsafeUnpinEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum UnsafeUnpinEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+
+                #[::pin_project::pin_project(!Unpin)]
+                #[derive(Debug)]
+                pub struct NotUnpinStruct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[::pin_project::pin_project(!Unpin)]
+                #[derive(Debug)]
+                pub struct NotUnpinTupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[::pin_project::pin_project(
+                    !Unpin,
+                    project = NotUnpinEnumProj,
+                    project_ref = NotUnpinEnumProjRef,
+                )]
+                #[derive(Debug)]
+                pub enum NotUnpinEnum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod box_pointers {
+    use pin_project::pin_project;
+
+    #[allow(box_pointers)] // for the type itself
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct Struct {
+        #[pin]
+        pub p: Box<isize>,
+        pub u: Box<isize>,
+    }
+
+    #[allow(box_pointers)] // for the type itself
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct TupleStruct(#[pin] pub Box<isize>, pub Box<isize>);
+
+    #[allow(box_pointers)] // for the type itself
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    #[derive(Debug)]
+    pub enum Enum {
+        Struct {
+            #[pin]
+            p: Box<isize>,
+            u: Box<isize>,
+        },
+        Tuple(#[pin] Box<isize>, Box<isize>),
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[allow(box_pointers)] // for the type itself
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct Struct {
+                    #[pin]
+                    pub p: Box<isize>,
+                    pub u: Box<isize>,
+                }
+
+                #[allow(box_pointers)] // for the type itself
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct TupleStruct(#[pin] pub Box<isize>, pub Box<isize>);
+
+                #[allow(box_pointers)] // for the type itself
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                #[derive(Debug)]
+                pub enum Enum {
+                    Struct {
+                        #[pin]
+                        p: Box<isize>,
+                        u: Box<isize>,
+                    },
+                    Tuple(#[pin] Box<isize>, Box<isize>),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod deprecated {
+    use pin_project::pin_project;
+
+    #[allow(deprecated)] // for the type itself
+    #[pin_project(project_replace)]
+    #[derive(Debug, Clone, Copy)]
+    #[deprecated]
+    pub struct Struct {
+        #[deprecated]
+        #[pin]
+        pub p: (),
+        #[deprecated]
+        pub u: (),
+    }
+
+    #[allow(deprecated)] // for the type itself
+    #[pin_project(project_replace)]
+    #[derive(Debug, Clone, Copy)]
+    #[deprecated]
+    pub struct TupleStruct(
+        #[deprecated]
+        #[pin]
+        pub (),
+        #[deprecated] pub (),
+    );
+
+    #[allow(deprecated)] // for the type itself
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    #[derive(Debug, Clone, Copy)]
+    #[deprecated]
+    pub enum Enum {
+        #[deprecated]
+        Struct {
+            #[deprecated]
+            #[pin]
+            p: (),
+            #[deprecated]
+            u: (),
+        },
+        #[deprecated]
+        Tuple(
+            #[deprecated]
+            #[pin]
+            (),
+            #[deprecated] (),
+        ),
+        #[deprecated]
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[allow(deprecated)] // for the type itself
+                #[pin_project(project_replace)]
+                #[derive(Debug, Clone, Copy)]
+                #[deprecated]
+                pub struct Struct {
+                    #[deprecated]
+                    #[pin]
+                    pub p: (),
+                    #[deprecated]
+                    pub u: (),
+                }
+
+                #[allow(deprecated)] // for the type itself
+                #[pin_project(project_replace)]
+                #[derive(Debug, Clone, Copy)]
+                #[deprecated]
+                pub struct TupleStruct(
+                    #[deprecated]
+                    #[pin]
+                    pub (),
+                    #[deprecated] pub (),
+                );
+
+                #[allow(deprecated)] // for the type itself
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                #[derive(Debug, Clone, Copy)]
+                #[deprecated]
+                pub enum Enum {
+                    #[deprecated]
+                    Struct {
+                        #[deprecated]
+                        #[pin]
+                        p: (),
+                        #[deprecated]
+                        u: (),
+                    },
+                    #[deprecated]
+                    Tuple(
+                        #[deprecated]
+                        #[pin]
+                        (),
+                        #[deprecated] (),
+                    ),
+                    #[deprecated]
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod explicit_outlives_requirements {
+    use pin_project::pin_project;
+
+    #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct Struct<'a, T, U>
+    where
+        T: ?Sized,
+        U: ?Sized,
+    {
+        #[pin]
+        pub pinned: &'a mut T,
+        pub unpinned: &'a mut U,
+    }
+
+    #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct TupleStruct<'a, T, U>(#[pin] pub &'a mut T, pub &'a mut U)
+    where
+        T: ?Sized,
+        U: ?Sized;
+
+    #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    #[derive(Debug)]
+    pub enum Enum<'a, T, U>
+    where
+        T: ?Sized,
+        U: ?Sized,
+    {
+        Struct {
+            #[pin]
+            pinned: &'a mut T,
+            unpinned: &'a mut U,
+        },
+        Tuple(#[pin] &'a mut T, &'a mut U),
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct Struct<'a, T, U>
+                where
+                    T: ?Sized,
+                    U: ?Sized,
+                {
+                    #[pin]
+                    pub pinned: &'a mut T,
+                    pub unpinned: &'a mut U,
+                }
+
+                #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct TupleStruct<'a, T, U>(#[pin] pub &'a mut T, pub &'a mut U)
+                where
+                    T: ?Sized,
+                    U: ?Sized;
+
+                #[allow(explicit_outlives_requirements)] // for the type itself: https://github.com/rust-lang/rust/issues/60993
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                #[derive(Debug)]
+                pub enum Enum<'a, T, U>
+                where
+                    T: ?Sized,
+                    U: ?Sized,
+                {
+                    Struct {
+                        #[pin]
+                        pinned: &'a mut T,
+                        unpinned: &'a mut U,
+                    },
+                    Tuple(#[pin] &'a mut T, &'a mut U),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+pub mod single_use_lifetimes {
+    use pin_project::pin_project;
+
+    #[allow(unused_lifetimes)]
+    pub trait Trait<'a> {}
+
+    #[allow(unused_lifetimes)] // for the type itself
+    #[allow(single_use_lifetimes)] // for the type itself: https://github.com/rust-lang/rust/issues/55058
+    #[pin_project(project_replace)]
+    pub struct Hrtb<'pin___, T>
+    where
+        for<'pin> &'pin T: Unpin,
+        T: for<'pin> Trait<'pin>,
+        for<'pin, 'pin_, 'pin__> &'pin &'pin_ &'pin__ T: Unpin,
+    {
+        #[pin]
+        _f: &'pin___ mut T,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[allow(unused_lifetimes)]
+                pub trait Trait<'a> {}
+
+                #[allow(unused_lifetimes)] // for the type itself
+                #[allow(single_use_lifetimes)] // for the type itself: https://github.com/rust-lang/rust/issues/55058
+                #[pin_project(project_replace)]
+                pub struct Hrtb<'pin___, T>
+                where
+                    for<'pin> &'pin T: Unpin,
+                    T: for<'pin> Trait<'pin>,
+                    for<'pin, 'pin_, 'pin__> &'pin &'pin_ &'pin__ T: Unpin,
+                {
+                    #[pin]
+                    _f: &'pin___ mut T,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod variant_size_differences {
+    use pin_project::pin_project;
+
+    #[allow(missing_debug_implementations, missing_copy_implementations)] // https://github.com/rust-lang/rust/pull/74060
+    #[allow(variant_size_differences)] // for the type itself
+    #[allow(clippy::large_enum_variant)] // for the type itself
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    pub enum Enum {
+        V1(u8),
+        V2([u8; 1024]),
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[allow(missing_debug_implementations, missing_copy_implementations)] // https://github.com/rust-lang/rust/pull/74060
+                #[allow(variant_size_differences)] // for the type itself
+                #[allow(clippy::large_enum_variant)] // for the type itself
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                pub enum Enum {
+                    V1(u8),
+                    V2([u8; 1024]),
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+pub mod clippy_mut_mut {
+    use pin_project::pin_project;
+
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct Struct<'a, T, U> {
+        #[pin]
+        pub pinned: &'a mut T,
+        pub unpinned: &'a mut U,
+    }
+
+    #[pin_project(project_replace)]
+    #[derive(Debug)]
+    pub struct TupleStruct<'a, T, U>(#[pin] &'a mut T, &'a mut U);
+
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    #[derive(Debug)]
+    pub enum Enum<'a, T, U> {
+        Struct {
+            #[pin]
+            pinned: &'a mut T,
+            unpinned: &'a mut U,
+        },
+        Tuple(#[pin] &'a mut T, &'a mut U),
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct Struct<'a, T, U> {
+                    #[pin]
+                    pub pinned: &'a mut T,
+                    pub unpinned: &'a mut U,
+                }
+
+                #[pin_project(project_replace)]
+                #[derive(Debug)]
+                pub struct TupleStruct<'a, T, U>(#[pin] &'a mut T, &'a mut U);
+
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                #[derive(Debug)]
+                pub enum Enum<'a, T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: &'a mut T,
+                        unpinned: &'a mut U,
+                    },
+                    Tuple(#[pin] &'a mut T, &'a mut U),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+#[allow(unreachable_pub)]
+mod clippy_redundant_pub_crate {
+    use pin_project::pin_project;
+
+    #[pin_project(project_replace)]
+    pub struct Struct<T, U> {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct TupleStruct<T, U>(#[pin] pub T, pub U);
+
+    #[allow(dead_code)]
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    pub enum Enum<T, U> {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Tuple(#[pin] T, U),
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[allow(clippy::redundant_pub_crate)]
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[pin_project(project_replace)]
+                pub struct Struct<T, U> {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[pin_project(project_replace)]
+                pub struct TupleStruct<T, U>(#[pin] pub T, pub U);
+
+                #[allow(dead_code)]
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                pub enum Enum<T, U> {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+pub mod clippy_type_repetition_in_bounds {
+    use pin_project::pin_project;
+
+    #[pin_project(project_replace)]
+    pub struct Struct<T, U>
+    where
+        Self: Sized,
+    {
+        #[pin]
+        pub pinned: T,
+        pub unpinned: U,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct TupleStruct<T, U>(#[pin] T, U)
+    where
+        Self: Sized;
+
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    pub enum Enum<T, U>
+    where
+        Self: Sized,
+    {
+        Struct {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+        Tuple(#[pin] T, U),
+        Unit,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[pin_project(project_replace)]
+                pub struct Struct<T, U>
+                where
+                    Self: Sized,
+                {
+                    #[pin]
+                    pub pinned: T,
+                    pub unpinned: U,
+                }
+
+                #[pin_project(project_replace)]
+                pub struct TupleStruct<T, U>(#[pin] T, U)
+                where
+                    Self: Sized;
+
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                pub enum Enum<T, U>
+                where
+                    Self: Sized,
+                {
+                    Struct {
+                        #[pin]
+                        pinned: T,
+                        unpinned: U,
+                    },
+                    Tuple(#[pin] T, U),
+                    Unit,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+pub mod clippy_use_self {
+    use pin_project::pin_project;
+
+    pub trait Trait {
+        type Assoc;
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Generics<T: Trait<Assoc = Self>>
+    where
+        Self: Trait<Assoc = Self>,
+    {
+        _f: T,
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        use super::Trait;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[pin_project(project_replace)]
+                pub struct Generics<T: Trait<Assoc = Self>>
+                where
+                    Self: Trait<Assoc = Self>,
+                {
+                    _f: T,
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+pub mod clippy_used_underscore_binding {
+    use pin_project::pin_project;
+
+    #[pin_project(project_replace)]
+    pub struct Struct<T, U> {
+        #[pin]
+        pub _pinned: T,
+        pub _unpinned: U,
+    }
+
+    #[pin_project(
+        project = EnumProj,
+        project_ref = EnumProjRef,
+        project_replace = EnumProjOwn,
+    )]
+    pub enum Enum<T, U> {
+        Struct {
+            #[pin]
+            _pinned: T,
+            _unpinned: U,
+        },
+    }
+
+    pub mod inside_macro {
+        use pin_project::pin_project;
+
+        #[rustfmt::skip]
+        macro_rules! mac {
+            () => {
+                #[pin_project(project_replace)]
+                pub struct Struct<T, U> {
+                    #[pin]
+                    pub _pinned: T,
+                    pub _unpinned: U,
+                }
+
+                #[pin_project(
+                    project = EnumProj,
+                    project_ref = EnumProjRef,
+                    project_replace = EnumProjOwn,
+                )]
+                pub enum Enum<T, U> {
+                    Struct {
+                        #[pin]
+                        _pinned: T,
+                        _unpinned: U,
+                    },
+                }
+            };
+        }
+
+        mac!();
+    }
+}
+
+#[allow(missing_debug_implementations)]
+pub mod clippy_ref_option_ref {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    pub struct Struct<'a> {
+        #[pin]
+        pub _pinned: Option<&'a ()>,
+        pub _unpinned: Option<&'a ()>,
+    }
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef)]
+    pub enum Enum<'a> {
+        Struct {
+            #[pin]
+            _pinned: Option<&'a ()>,
+            _unpinned: Option<&'a ()>,
+        },
+    }
+}
diff --git a/third_party/rust/pin-project/tests/pin_project.rs b/third_party/rust/pin-project/tests/pin_project.rs
new file mode 100644
index 0000000000..aa08056e81
--- /dev/null
+++ b/third_party/rust/pin-project/tests/pin_project.rs
@@ -0,0 +1,887 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+#[macro_use]
+mod auxiliary;
+
+use std::{
+    marker::{PhantomData, PhantomPinned},
+    panic,
+    pin::Pin,
+};
+
+use pin_project::{pin_project, pinned_drop, UnsafeUnpin};
+
+#[test]
+fn projection() {
+    #[pin_project(
+        project = StructProj,
+        project_ref = StructProjRef,
+        project_replace = StructProjOwn,
+    )]
+    struct Struct<T, U> {
+        #[pin]
+        f1: T,
+        f2: U,
+    }
+
+    let mut s = Struct { f1: 1, f2: 2 };
+    let mut s_orig = Pin::new(&mut s);
+    let s = s_orig.as_mut().project();
+
+    let _: Pin<&mut i32> = s.f1;
+    assert_eq!(*s.f1, 1);
+    let _: &mut i32 = s.f2;
+    assert_eq!(*s.f2, 2);
+
+    assert_eq!(s_orig.as_ref().f1, 1);
+    assert_eq!(s_orig.as_ref().f2, 2);
+
+    let mut s = Struct { f1: 1, f2: 2 };
+    let mut s = Pin::new(&mut s);
+    {
+        let StructProj { f1, f2 } = s.as_mut().project();
+        let _: Pin<&mut i32> = f1;
+        let _: &mut i32 = f2;
+    }
+    {
+        let StructProjRef { f1, f2 } = s.as_ref().project_ref();
+        let _: Pin<&i32> = f1;
+        let _: &i32 = f2;
+    }
+    {
+        let StructProjOwn { f1, f2 } = s.as_mut().project_replace(Struct { f1: 3, f2: 4 });
+        let _: PhantomData<i32> = f1;
+        let _: i32 = f2;
+        assert_eq!(f2, 2);
+        assert_eq!(s.f1, 3);
+        assert_eq!(s.f2, 4);
+    }
+
+    #[pin_project(project_replace)]
+    struct TupleStruct<T, U>(#[pin] T, U);
+
+    let mut s = TupleStruct(1, 2);
+    let s = Pin::new(&mut s).project();
+
+    let _: Pin<&mut i32> = s.0;
+    assert_eq!(*s.0, 1);
+    let _: &mut i32 = s.1;
+    assert_eq!(*s.1, 2);
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    #[derive(Eq, PartialEq, Debug)]
+    enum Enum<A, B, C, D> {
+        Tuple(#[pin] A, B),
+        Struct {
+            #[pin]
+            f1: C,
+            f2: D,
+        },
+        Unit,
+    }
+
+    let mut e = Enum::Tuple(1, 2);
+    let mut e = Pin::new(&mut e);
+
+    match e.as_mut().project() {
+        EnumProj::Tuple(x, y) => {
+            let x: Pin<&mut i32> = x;
+            assert_eq!(*x, 1);
+            let y: &mut i32 = y;
+            assert_eq!(*y, 2);
+        }
+        EnumProj::Struct { f1, f2 } => {
+            let _: Pin<&mut i32> = f1;
+            let _: &mut i32 = f2;
+            unreachable!();
+        }
+        EnumProj::Unit => unreachable!(),
+    }
+
+    assert_eq!(&*e, &Enum::Tuple(1, 2));
+
+    let mut e = Enum::Struct { f1: 3, f2: 4 };
+    let mut e = Pin::new(&mut e);
+
+    match e.as_mut().project() {
+        EnumProj::Tuple(x, y) => {
+            let _: Pin<&mut i32> = x;
+            let _: &mut i32 = y;
+            unreachable!();
+        }
+        EnumProj::Struct { f1, f2 } => {
+            let _: Pin<&mut i32> = f1;
+            assert_eq!(*f1, 3);
+            let _: &mut i32 = f2;
+            assert_eq!(*f2, 4);
+        }
+        EnumProj::Unit => unreachable!(),
+    }
+
+    if let EnumProj::Struct { f1, f2 } = e.as_mut().project() {
+        let _: Pin<&mut i32> = f1;
+        assert_eq!(*f1, 3);
+        let _: &mut i32 = f2;
+        assert_eq!(*f2, 4);
+    }
+}
+
+#[test]
+fn enum_project_set() {
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    #[derive(Eq, PartialEq, Debug)]
+    enum Enum {
+        V1(#[pin] u8),
+        V2(bool),
+    }
+
+    let mut e = Enum::V1(25);
+    let mut e_orig = Pin::new(&mut e);
+    let e_proj = e_orig.as_mut().project();
+
+    match e_proj {
+        EnumProj::V1(val) => {
+            let new_e = Enum::V2(val.as_ref().get_ref() == &25);
+            e_orig.set(new_e);
+        }
+        EnumProj::V2(_) => unreachable!(),
+    }
+
+    assert_eq!(e, Enum::V2(true));
+}
+
+#[test]
+fn where_clause() {
+    #[pin_project]
+    struct Struct<T>
+    where
+        T: Copy,
+    {
+        f: T,
+    }
+
+    #[pin_project]
+    struct TupleStruct<T>(T)
+    where
+        T: Copy;
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum<T>
+    where
+        T: Copy,
+    {
+        V(T),
+    }
+}
+
+#[test]
+fn where_clause_and_associated_type_field() {
+    #[pin_project(project_replace)]
+    struct Struct1<I>
+    where
+        I: Iterator,
+    {
+        #[pin]
+        f1: I,
+        f2: I::Item,
+    }
+
+    #[pin_project(project_replace)]
+    struct Struct2<I, J>
+    where
+        I: Iterator<Item = J>,
+    {
+        #[pin]
+        f1: I,
+        f2: J,
+    }
+
+    #[pin_project(project_replace)]
+    struct Struct3<T>
+    where
+        T: 'static,
+    {
+        f: T,
+    }
+
+    trait Static: 'static {}
+
+    impl<T> Static for Struct3<T> {}
+
+    #[pin_project(project_replace)]
+    struct TupleStruct<I>(#[pin] I, I::Item)
+    where
+        I: Iterator;
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum<I>
+    where
+        I: Iterator,
+    {
+        V1(#[pin] I),
+        V2(I::Item),
+    }
+}
+
+#[test]
+fn derive_copy() {
+    #[pin_project(project_replace)]
+    #[derive(Clone, Copy)]
+    struct Struct<T> {
+        f: T,
+    }
+
+    fn is_copy<T: Copy>() {}
+
+    is_copy::<Struct<u8>>();
+}
+
+#[test]
+fn move_out() {
+    struct NotCopy;
+
+    #[pin_project(project_replace)]
+    struct Struct {
+        f: NotCopy,
+    }
+
+    let x = Struct { f: NotCopy };
+    let _val: NotCopy = x.f;
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum {
+        V(NotCopy),
+    }
+
+    let x = Enum::V(NotCopy);
+    #[allow(clippy::infallible_destructuring_match)]
+    let _val: NotCopy = match x {
+        Enum::V(val) => val,
+    };
+}
+
+#[test]
+fn trait_bounds_on_type_generics() {
+    #[pin_project(project_replace)]
+    pub struct Struct1<'a, T: ?Sized> {
+        f: &'a mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct2<'a, T: ::core::fmt::Debug> {
+        f: &'a mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct3<'a, T: core::fmt::Debug> {
+        f: &'a mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct4<'a, T: core::fmt::Debug + core::fmt::Display> {
+        f: &'a mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct5<'a, T: core::fmt::Debug + ?Sized> {
+        f: &'a mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct6<'a, T: core::fmt::Debug = [u8; 16]> {
+        f: &'a mut T,
+    }
+
+    let _: Struct6<'_> = Struct6 { f: &mut [0_u8; 16] };
+
+    #[pin_project(project_replace)]
+    pub struct Struct7<T: 'static> {
+        f: T,
+    }
+
+    trait Static: 'static {}
+
+    impl<T> Static for Struct7<T> {}
+
+    #[pin_project(project_replace)]
+    pub struct Struct8<'a, 'b: 'a> {
+        f1: &'a u8,
+        f2: &'b u8,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct TupleStruct<'a, T: ?Sized>(&'a mut T);
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum<'a, T: ?Sized> {
+        V(&'a mut T),
+    }
+}
+
+#[test]
+fn overlapping_lifetime_names() {
+    #[pin_project(project_replace)]
+    pub struct Struct1<'pin, T> {
+        #[pin]
+        f: &'pin mut T,
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct2<'pin, 'pin_, 'pin__> {
+        #[pin]
+        f: &'pin &'pin_ &'pin__ (),
+    }
+
+    pub trait Trait<'a> {}
+
+    #[allow(single_use_lifetimes)] // https://github.com/rust-lang/rust/issues/55058
+    #[pin_project(project_replace)]
+    pub struct Hrtb<'pin___, T>
+    where
+        for<'pin> &'pin T: Unpin,
+        T: for<'pin> Trait<'pin>,
+        for<'pin, 'pin_, 'pin__> &'pin &'pin_ &'pin__ T: Unpin,
+    {
+        #[pin]
+        f: &'pin___ mut T,
+    }
+
+    #[pin_project(PinnedDrop)]
+    pub struct PinnedDropStruct<'pin> {
+        #[pin]
+        f: &'pin (),
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for PinnedDropStruct<'_> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(UnsafeUnpin)]
+    pub struct UnsafeUnpinStruct<'pin> {
+        #[pin]
+        f: &'pin (),
+    }
+
+    unsafe impl UnsafeUnpin for UnsafeUnpinStruct<'_> {}
+
+    #[pin_project(!Unpin)]
+    pub struct NotUnpinStruct<'pin> {
+        #[pin]
+        f: &'pin (),
+    }
+}
+
+#[test]
+fn combine() {
+    #[pin_project(PinnedDrop, UnsafeUnpin)]
+    pub struct PinnedDropWithUnsafeUnpin<T> {
+        #[pin]
+        f: T,
+    }
+
+    #[pinned_drop]
+    impl<T> PinnedDrop for PinnedDropWithUnsafeUnpin<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    unsafe impl<T: Unpin> UnsafeUnpin for PinnedDropWithUnsafeUnpin<T> {}
+
+    #[pin_project(PinnedDrop, !Unpin)]
+    pub struct PinnedDropWithNotUnpin<T> {
+        #[pin]
+        f: T,
+    }
+
+    #[pinned_drop]
+    impl<T> PinnedDrop for PinnedDropWithNotUnpin<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(UnsafeUnpin, project_replace)]
+    pub struct UnsafeUnpinWithReplace<T> {
+        #[pin]
+        f: T,
+    }
+
+    unsafe impl<T: Unpin> UnsafeUnpin for UnsafeUnpinWithReplace<T> {}
+
+    #[pin_project(!Unpin, project_replace)]
+    pub struct NotUnpinWithReplace<T> {
+        #[pin]
+        f: T,
+    }
+}
+
+#[test]
+fn private_type_in_public_type() {
+    #[pin_project(project_replace)]
+    pub struct PublicStruct<T> {
+        #[pin]
+        inner: PrivateStruct<T>,
+    }
+
+    struct PrivateStruct<T>(T);
+}
+
+#[allow(clippy::needless_lifetimes)]
+#[test]
+fn lifetime_project() {
+    #[pin_project(project_replace)]
+    struct Struct1<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+
+    #[pin_project(project_replace)]
+    struct Struct2<'a, T, U> {
+        #[pin]
+        pinned: &'a T,
+        unpinned: U,
+    }
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum<T, U> {
+        V {
+            #[pin]
+            pinned: T,
+            unpinned: U,
+        },
+    }
+
+    impl<T, U> Struct1<T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut T> {
+            self.project().pinned
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut T> {
+            self.project().pinned
+        }
+    }
+
+    impl<'b, T, U> Struct2<'b, T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a &'b T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut &'b T> {
+            self.project().pinned
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&&'b T> {
+            self.project_ref().pinned
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut &'b T> {
+            self.project().pinned
+        }
+    }
+
+    impl<T, U> Enum<T, U> {
+        fn get_pin_ref<'a>(self: Pin<&'a Self>) -> Pin<&'a T> {
+            match self.project_ref() {
+                EnumProjRef::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_mut<'a>(self: Pin<&'a mut Self>) -> Pin<&'a mut T> {
+            match self.project() {
+                EnumProj::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_ref_elided(self: Pin<&Self>) -> Pin<&T> {
+            match self.project_ref() {
+                EnumProjRef::V { pinned, .. } => pinned,
+            }
+        }
+        fn get_pin_mut_elided(self: Pin<&mut Self>) -> Pin<&mut T> {
+            match self.project() {
+                EnumProj::V { pinned, .. } => pinned,
+            }
+        }
+    }
+}
+
+mod visibility {
+    use pin_project::pin_project;
+
+    #[pin_project(project_replace)]
+    pub(crate) struct S {
+        pub f: u8,
+    }
+}
+
+#[test]
+fn visibility() {
+    let mut x = visibility::S { f: 0 };
+    let x = Pin::new(&mut x);
+    let y = x.as_ref().project_ref();
+    let _: &u8 = y.f;
+    let y = x.project();
+    let _: &mut u8 = y.f;
+}
+
+#[test]
+fn trivial_bounds() {
+    #[pin_project(project_replace)]
+    pub struct NoGenerics {
+        #[pin]
+        f: PhantomPinned,
+    }
+
+    assert_not_unpin!(NoGenerics);
+}
+
+#[test]
+fn dst() {
+    #[pin_project]
+    struct Struct1<T: ?Sized> {
+        f: T,
+    }
+
+    let mut x = Struct1 { f: 0_u8 };
+    let x: Pin<&mut Struct1<dyn core::fmt::Debug>> = Pin::new(&mut x as _);
+    let _: &mut (dyn core::fmt::Debug) = x.project().f;
+
+    #[pin_project]
+    struct Struct2<T: ?Sized> {
+        #[pin]
+        f: T,
+    }
+
+    let mut x = Struct2 { f: 0_u8 };
+    let x: Pin<&mut Struct2<dyn core::fmt::Debug + Unpin>> = Pin::new(&mut x as _);
+    let _: Pin<&mut (dyn core::fmt::Debug + Unpin)> = x.project().f;
+
+    #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+    #[pin_project]
+    struct Struct3<T>
+    where
+        T: ?Sized,
+    {
+        f: T,
+    }
+
+    #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+    #[pin_project]
+    struct Struct4<T>
+    where
+        T: ?Sized,
+    {
+        #[pin]
+        f: T,
+    }
+
+    #[pin_project(UnsafeUnpin)]
+    struct Struct5<T: ?Sized> {
+        f: T,
+    }
+
+    #[pin_project(UnsafeUnpin)]
+    struct Struct6<T: ?Sized> {
+        #[pin]
+        f: T,
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Struct7<T: ?Sized> {
+        f: T,
+    }
+
+    #[pinned_drop]
+    impl<T: ?Sized> PinnedDrop for Struct7<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Struct8<T: ?Sized> {
+        #[pin]
+        f: T,
+    }
+
+    #[pinned_drop]
+    impl<T: ?Sized> PinnedDrop for Struct8<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(!Unpin)]
+    struct Struct9<T: ?Sized> {
+        f: T,
+    }
+
+    #[pin_project(!Unpin)]
+    struct Struct10<T: ?Sized> {
+        #[pin]
+        f: T,
+    }
+
+    #[pin_project]
+    struct Struct11<'a, T: ?Sized, U: ?Sized> {
+        f1: &'a mut T,
+        f2: U,
+    }
+
+    #[pin_project]
+    struct TupleStruct1<T: ?Sized>(T);
+
+    #[pin_project]
+    struct TupleStruct2<T: ?Sized>(#[pin] T);
+
+    #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+    #[pin_project]
+    struct TupleStruct3<T>(T)
+    where
+        T: ?Sized;
+
+    #[allow(explicit_outlives_requirements)] // https://github.com/rust-lang/rust/issues/60993
+    #[pin_project]
+    struct TupleStruct4<T>(#[pin] T)
+    where
+        T: ?Sized;
+
+    #[pin_project(UnsafeUnpin)]
+    struct TupleStruct5<T: ?Sized>(T);
+
+    #[pin_project(UnsafeUnpin)]
+    struct TupleStruct6<T: ?Sized>(#[pin] T);
+
+    #[pin_project(PinnedDrop)]
+    struct TupleStruct7<T: ?Sized>(T);
+
+    #[pinned_drop]
+    impl<T: ?Sized> PinnedDrop for TupleStruct7<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct TupleStruct8<T: ?Sized>(#[pin] T);
+
+    #[pinned_drop]
+    impl<T: ?Sized> PinnedDrop for TupleStruct8<T> {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(!Unpin)]
+    struct TupleStruct9<T: ?Sized>(T);
+
+    #[pin_project(!Unpin)]
+    struct TupleStruct10<T: ?Sized>(#[pin] T);
+
+    #[pin_project]
+    struct TupleStruct11<'a, T: ?Sized, U: ?Sized>(&'a mut T, U);
+}
+
+#[test]
+fn dyn_type() {
+    #[pin_project]
+    struct Struct1 {
+        f: dyn core::fmt::Debug,
+    }
+
+    #[pin_project]
+    struct Struct2 {
+        #[pin]
+        f: dyn core::fmt::Debug,
+    }
+
+    #[pin_project]
+    struct Struct3 {
+        f: dyn core::fmt::Debug + Send,
+    }
+
+    #[pin_project]
+    struct Struct4 {
+        #[pin]
+        f: dyn core::fmt::Debug + Send,
+    }
+
+    #[pin_project]
+    struct TupleStruct1(dyn core::fmt::Debug);
+
+    #[pin_project]
+    struct TupleStruct2(#[pin] dyn core::fmt::Debug);
+
+    #[pin_project]
+    struct TupleStruct3(dyn core::fmt::Debug + Send);
+
+    #[pin_project]
+    struct TupleStruct4(#[pin] dyn core::fmt::Debug + Send);
+}
+
+#[test]
+fn parse_self() {
+    macro_rules! mac {
+        ($($tt:tt)*) => {
+            $($tt)*
+        };
+    }
+
+    pub trait Trait {
+        type Assoc;
+    }
+
+    #[allow(clippy::type_repetition_in_bounds)]
+    #[pin_project(project_replace)]
+    pub struct Generics<T: Trait<Assoc = Self>>
+    where
+        Self: Trait<Assoc = Self>,
+        <Self as Trait>::Assoc: Sized,
+        mac!(Self): Trait<Assoc = mac!(Self)>,
+    {
+        _f: T,
+    }
+
+    impl<T: Trait<Assoc = Self>> Trait for Generics<T> {
+        type Assoc = Self;
+    }
+
+    #[pin_project(project_replace)]
+    pub struct Struct {
+        _f1: Box<Self>,
+        _f2: Box<<Self as Trait>::Assoc>,
+        _f3: Box<mac!(Self)>,
+        _f4: [(); Self::ASSOC],
+        _f5: [(); Self::assoc()],
+        _f6: [(); mac!(Self::assoc())],
+    }
+
+    impl Struct {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Struct {
+        type Assoc = Self;
+    }
+
+    #[pin_project(project_replace)]
+    struct Tuple(
+        Box<Self>,
+        Box<<Self as Trait>::Assoc>,
+        Box<mac!(Self)>,
+        [(); Self::ASSOC],
+        [(); Self::assoc()],
+        [(); mac!(Self::assoc())],
+    );
+
+    impl Tuple {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Tuple {
+        type Assoc = Self;
+    }
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef, project_replace = EnumProjOwn)]
+    enum Enum {
+        Struct {
+            _f1: Box<Self>,
+            _f2: Box<<Self as Trait>::Assoc>,
+            _f3: Box<mac!(Self)>,
+            _f4: [(); Self::ASSOC],
+            _f5: [(); Self::assoc()],
+            _f6: [(); mac!(Self::assoc())],
+        },
+        Tuple(
+            Box<Self>,
+            Box<<Self as Trait>::Assoc>,
+            Box<mac!(Self)>,
+            [(); Self::ASSOC],
+            [(); Self::assoc()],
+            [(); mac!(Self::assoc())],
+        ),
+    }
+
+    impl Enum {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Enum {
+        type Assoc = Self;
+    }
+}
+
+#[test]
+fn no_infer_outlives() {
+    trait Trait<X> {
+        type Y;
+    }
+
+    struct Struct1<A>(A);
+
+    impl<X, T> Trait<X> for Struct1<T> {
+        type Y = Option<T>;
+    }
+
+    #[pin_project(project_replace)]
+    struct Struct2<A, B> {
+        _f: <Struct1<A> as Trait<B>>::Y,
+    }
+}
+
+// https://github.com/rust-lang/rust/issues/47949
+// https://github.com/taiki-e/pin-project/pull/194#discussion_r419098111
+#[allow(clippy::many_single_char_names)]
+#[test]
+fn project_replace_panic() {
+    #[pin_project(project_replace)]
+    struct S<T, U> {
+        #[pin]
+        pinned: T,
+        unpinned: U,
+    }
+
+    struct D<'a>(&'a mut bool, bool);
+    impl Drop for D<'_> {
+        fn drop(&mut self) {
+            *self.0 = true;
+            if self.1 {
+                panic!();
+            }
+        }
+    }
+
+    let (mut a, mut b, mut c, mut d) = (false, false, false, false);
+    let res = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let mut x = S { pinned: D(&mut a, true), unpinned: D(&mut b, false) };
+        let _y = Pin::new(&mut x)
+            .project_replace(S { pinned: D(&mut c, false), unpinned: D(&mut d, false) });
+        // Previous `x.pinned` was dropped and panicked when `project_replace` is
+        // called, so this is unreachable.
+        unreachable!();
+    }));
+    assert!(res.is_err());
+    assert!(a);
+    assert!(b);
+    assert!(c);
+    assert!(d);
+
+    let (mut a, mut b, mut c, mut d) = (false, false, false, false);
+    let res = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let mut x = S { pinned: D(&mut a, false), unpinned: D(&mut b, true) };
+        {
+            let _y = Pin::new(&mut x)
+                .project_replace(S { pinned: D(&mut c, false), unpinned: D(&mut d, false) });
+            // `_y` (previous `x.unpinned`) live to the end of this scope, so
+            // this is not unreachable.
+            // unreachable!();
+        }
+        unreachable!();
+    }));
+    assert!(res.is_err());
+    assert!(a);
+    assert!(b);
+    assert!(c);
+    assert!(d);
+}
diff --git a/third_party/rust/pin-project/tests/pinned_drop.rs b/third_party/rust/pin-project/tests/pinned_drop.rs
new file mode 100644
index 0000000000..99273c4234
--- /dev/null
+++ b/third_party/rust/pin-project/tests/pinned_drop.rs
@@ -0,0 +1,284 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[test]
+fn safe_project() {
+    #[pin_project(PinnedDrop)]
+    pub struct Struct<'a> {
+        was_dropped: &'a mut bool,
+        #[pin]
+        field: u8,
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for Struct<'_> {
+        fn drop(self: Pin<&mut Self>) {
+            **self.project().was_dropped = true;
+        }
+    }
+
+    let mut was_dropped = false;
+    drop(Struct { was_dropped: &mut was_dropped, field: 42 });
+    assert!(was_dropped);
+}
+
+#[test]
+fn self_call() {
+    #[pin_project(PinnedDrop)]
+    pub struct S<T>(T);
+
+    trait Trait {
+        fn self_ref(&self) {}
+        fn self_pin_ref(self: Pin<&Self>) {}
+        fn self_mut(&mut self) {}
+        fn self_pin_mut(self: Pin<&mut Self>) {}
+        fn assoc_fn(_this: Pin<&mut Self>) {}
+    }
+
+    impl<T> Trait for S<T> {}
+
+    #[pinned_drop]
+    impl<T> PinnedDrop for S<T> {
+        fn drop(mut self: Pin<&mut Self>) {
+            self.self_ref();
+            self.as_ref().self_pin_ref();
+            self.self_mut();
+            self.as_mut().self_pin_mut();
+            Self::assoc_fn(self.as_mut());
+            <Self>::assoc_fn(self.as_mut());
+        }
+    }
+}
+
+#[test]
+fn self_ty() {
+    #[pin_project(PinnedDrop)]
+    pub struct Struct {
+        pub f: (),
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for Struct {
+        #[allow(irrefutable_let_patterns)]
+        #[allow(clippy::match_single_binding)]
+        fn drop(mut self: Pin<&mut Self>) {
+            // expr
+            let _: Self = Self { f: () };
+
+            // pat
+            match *self {
+                Self { f: () } => {}
+            }
+            if let Self { f: () } = *self {}
+            let Self { f: () } = *self;
+        }
+    }
+
+    #[pin_project(PinnedDrop)]
+    pub struct TupleStruct(());
+
+    #[pinned_drop]
+    impl PinnedDrop for TupleStruct {
+        #[allow(irrefutable_let_patterns)]
+        fn drop(mut self: Pin<&mut Self>) {
+            // expr
+            let _: Self = Self(());
+
+            // pat
+            match *self {
+                Self(_) => {}
+            }
+            if let Self(_) = *self {}
+            let Self(_) = *self;
+        }
+    }
+
+    #[pin_project(PinnedDrop, project = EnumProj, project_ref = EnumProjRef)]
+    pub enum Enum {
+        Struct { f: () },
+        Tuple(()),
+        Unit,
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for Enum {
+        fn drop(mut self: Pin<&mut Self>) {
+            // expr
+            let _: Self = Self::Struct { f: () };
+            let _: Self = Self::Tuple(());
+            let _: Self = Self::Unit;
+
+            // pat
+            match *self {
+                Self::Struct { f: () } => {}
+                Self::Tuple(_) => {}
+                Self::Unit => {}
+            }
+            if let Self::Struct { f: () } = *self {}
+            if let Self::Tuple(_) = *self {}
+            if let Self::Unit = *self {}
+        }
+    }
+}
+
+#[test]
+fn self_inside_macro_containing_fn() {
+    macro_rules! mac {
+        ($($tt:tt)*) => {
+            $($tt)*
+        };
+    }
+
+    #[pin_project(PinnedDrop)]
+    pub struct S(());
+
+    #[pinned_drop]
+    impl PinnedDrop for S {
+        fn drop(self: Pin<&mut Self>) {
+            mac!({
+                impl S {
+                    pub fn _f(self) -> Self {
+                        self
+                    }
+                }
+            });
+        }
+    }
+}
+
+// See also `ui/pinned_drop/self.rs`.
+#[rustversion::since(1.40)] // https://github.com/rust-lang/rust/pull/64690
+#[test]
+fn self_inside_macro_def() {
+    #[pin_project(PinnedDrop)]
+    pub struct S(());
+
+    #[pinned_drop]
+    impl PinnedDrop for S {
+        fn drop(self: Pin<&mut Self>) {
+            macro_rules! mac {
+                () => {{
+                    let _ = self;
+                    let _ = Self(());
+                }};
+            }
+            mac!();
+        }
+    }
+}
+
+#[test]
+fn self_arg_inside_macro_call() {
+    #[pin_project(PinnedDrop)]
+    struct Struct {
+        f: (),
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for Struct {
+        fn drop(self: Pin<&mut Self>) {
+            let _: Vec<_> = vec![self.f];
+        }
+    }
+}
+
+#[test]
+fn self_ty_inside_macro_call() {
+    macro_rules! mac {
+        ($($tt:tt)*) => {
+            $($tt)*
+        };
+    }
+
+    #[pin_project(PinnedDrop)]
+    pub struct Struct<T: Send>
+    where
+        mac!(Self): Send,
+    {
+        _f: T,
+    }
+
+    impl<T: Send> Struct<T> {
+        const ASSOC1: usize = 1;
+        fn assoc1() {}
+    }
+
+    trait Trait {
+        type Assoc2;
+        const ASSOC2: usize;
+        fn assoc2();
+    }
+
+    impl<T: Send> Trait for Struct<T> {
+        type Assoc2 = u8;
+        const ASSOC2: usize = 2;
+        fn assoc2() {}
+    }
+
+    #[pinned_drop]
+    impl<T: Send> PinnedDrop for Struct<T>
+    where
+        mac!(Self): Send,
+    {
+        #[allow(path_statements)]
+        #[allow(clippy::no_effect)]
+        fn drop(self: Pin<&mut Self>) {
+            // inherent items
+            mac!(Self::ASSOC1;);
+            mac!(<Self>::ASSOC1;);
+            mac!(Self::assoc1(););
+            mac!(<Self>::assoc1(););
+
+            // trait items
+            mac!(let _: <Self as Trait>::Assoc2;);
+            mac!(Self::ASSOC2;);
+            mac!(<Self>::ASSOC2;);
+            mac!(<Self as Trait>::ASSOC2;);
+            mac!(Self::assoc2(););
+            mac!(<Self>::assoc2(););
+            mac!(<Self as Trait>::assoc2(););
+        }
+    }
+}
+
+#[test]
+fn inside_macro() {
+    #[pin_project(PinnedDrop)]
+    struct S(());
+
+    macro_rules! mac {
+        ($expr:expr) => {
+            #[pinned_drop]
+            impl PinnedDrop for S {
+                fn drop(self: Pin<&mut Self>) {
+                    let _ = $expr;
+                }
+            }
+        };
+    }
+
+    mac!(1);
+}
+
+pub mod self_path {
+    use super::*;
+
+    #[pin_project(PinnedDrop)]
+    pub struct S<T: Unpin>(T);
+
+    fn f() {}
+
+    #[pinned_drop]
+    impl<T: Unpin> PinnedDrop for self::S<T> {
+        fn drop(mut self: Pin<&mut Self>) {
+            self::f();
+            let _: self::S<()> = self::S(());
+            let _: self::S<Pin<&mut Self>> = self::S(self.as_mut());
+            let self::S(()) = self::S(());
+            let self::S(&mut Self(_)) = self::S(&mut *self);
+        }
+    }
+}
diff --git a/third_party/rust/pin-project/tests/proper_unpin.rs b/third_party/rust/pin-project/tests/proper_unpin.rs
new file mode 100644
index 0000000000..0ba3ce3b5d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/proper_unpin.rs
@@ -0,0 +1,153 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+#[macro_use]
+mod auxiliary;
+
+pub mod default {
+    use std::marker::PhantomPinned;
+
+    use pin_project::pin_project;
+
+    struct Inner<T> {
+        f: T,
+    }
+
+    assert_unpin!(Inner<()>);
+    assert_not_unpin!(Inner<PhantomPinned>);
+
+    #[pin_project]
+    struct Struct<T, U> {
+        #[pin]
+        f1: Inner<T>,
+        f2: U,
+    }
+
+    assert_unpin!(Struct<(), ()>);
+    assert_unpin!(Struct<(), PhantomPinned>);
+    assert_not_unpin!(Struct<PhantomPinned, ()>);
+    assert_not_unpin!(Struct<PhantomPinned, PhantomPinned>);
+
+    #[pin_project(project = EnumProj, project_ref = EnumProjRef)]
+    enum Enum<T, U> {
+        V1 {
+            #[pin]
+            f1: Inner<T>,
+            f2: U,
+        },
+    }
+
+    assert_unpin!(Enum<(), ()>);
+    assert_unpin!(Enum<(), PhantomPinned>);
+    assert_not_unpin!(Enum<PhantomPinned, ()>);
+    assert_not_unpin!(Enum<PhantomPinned, PhantomPinned>);
+
+    #[pin_project]
+    struct TrivialBounds {
+        #[pin]
+        f: PhantomPinned,
+    }
+
+    assert_not_unpin!(TrivialBounds);
+
+    #[pin_project]
+    struct PinRef<'a, T, U> {
+        #[pin]
+        f1: &'a mut Inner<T>,
+        f2: U,
+    }
+
+    assert_unpin!(PinRef<'_, PhantomPinned, PhantomPinned>);
+}
+
+pub mod cfg {
+    use std::marker::PhantomPinned;
+
+    use pin_project::pin_project;
+
+    #[pin_project]
+    struct Foo<T> {
+        #[cfg(any())]
+        #[pin]
+        f: T,
+        #[cfg(not(any()))]
+        f: T,
+    }
+
+    assert_unpin!(Foo<PhantomPinned>);
+
+    #[pin_project]
+    struct Bar<T> {
+        #[cfg(any())]
+        f: T,
+        #[cfg(not(any()))]
+        #[pin]
+        f: T,
+    }
+
+    assert_unpin!(Bar<()>);
+    assert_not_unpin!(Bar<PhantomPinned>);
+}
+
+pub mod cfg_attr {
+    use std::marker::PhantomPinned;
+
+    use pin_project::pin_project;
+
+    #[cfg_attr(any(), pin_project)]
+    struct Foo<T> {
+        f: T,
+    }
+
+    assert_unpin!(Foo<()>);
+    assert_not_unpin!(Foo<PhantomPinned>);
+
+    #[cfg_attr(not(any()), pin_project)]
+    struct Bar<T> {
+        #[cfg_attr(not(any()), pin)]
+        f: T,
+    }
+
+    assert_unpin!(Bar<()>);
+    assert_not_unpin!(Bar<PhantomPinned>);
+}
+
+// pin_project(!Unpin)
+pub mod not_unpin {
+    use std::marker::PhantomPinned;
+
+    use pin_project::pin_project;
+
+    struct Inner<T> {
+        f: T,
+    }
+
+    #[pin_project(!Unpin)]
+    struct Struct<T, U> {
+        #[pin]
+        inner: Inner<T>,
+        other: U,
+    }
+
+    assert_not_unpin!(Struct<(), ()>);
+    assert_not_unpin!(Struct<(), PhantomPinned>);
+    assert_not_unpin!(Struct<PhantomPinned, ()>);
+    assert_not_unpin!(Struct<PhantomPinned, PhantomPinned>);
+
+    #[pin_project(!Unpin)]
+    struct TrivialBounds {
+        #[pin]
+        f: PhantomPinned,
+    }
+
+    assert_not_unpin!(TrivialBounds);
+
+    #[pin_project(!Unpin)]
+    struct PinRef<'a, T, U> {
+        #[pin]
+        inner: &'a mut Inner<T>,
+        other: U,
+    }
+
+    assert_not_unpin!(PinRef<'_, (), ()>);
+}
diff --git a/third_party/rust/pin-project/tests/repr_packed.rs b/third_party/rust/pin-project/tests/repr_packed.rs
new file mode 100644
index 0000000000..be7cab975f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/repr_packed.rs
@@ -0,0 +1,52 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+// unaligned_references did not exist in older compilers and safe_packed_borrows was removed in the latest compilers.
+// https://github.com/rust-lang/rust/pull/82525
+#![allow(unknown_lints, renamed_and_removed_lints)]
+#![forbid(unaligned_references, safe_packed_borrows)]
+
+use std::cell::Cell;
+
+// Ensure that the compiler doesn't copy the fields
+// of #[repr(packed)] types during drop, if the field has alignment 1
+// (that is, any reference to the field is guaranteed to have proper alignment)
+// We are currently unable to statically prevent the usage of #[pin_project]
+// on #[repr(packed)] types composed entirely of fields of alignment 1.
+// This shouldn't lead to undefined behavior, as long as the compiler doesn't
+// try to move the field anyway during drop.
+//
+// This tests validates that the compiler is doing what we expect.
+#[test]
+fn weird_repr_packed() {
+    // We keep track of the field address during
+    // drop using a thread local, to avoid changing
+    // the layout of our #[repr(packed)] type.
+    thread_local! {
+        static FIELD_ADDR: Cell<usize> = Cell::new(0);
+    }
+
+    #[repr(packed)]
+    struct Struct {
+        field: u8,
+    }
+
+    impl Drop for Struct {
+        fn drop(&mut self) {
+            FIELD_ADDR.with(|f| {
+                f.set(&self.field as *const u8 as usize);
+            });
+        }
+    }
+
+    #[allow(clippy::let_and_return)]
+    let field_addr = {
+        // We let this field drop by going out of scope,
+        // rather than explicitly calling drop(foo).
+        // Calling drop(foo) causes 'foo' to be moved
+        // into the 'drop' function, resulting in a different
+        // address.
+        let x = Struct { field: 27 };
+        let field_addr = &x.field as *const u8 as usize;
+        field_addr
+    };
+    assert_eq!(field_addr, FIELD_ADDR.with(Cell::get));
+}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.rs b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.rs
new file mode 100644
index 0000000000..e36cc9593a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.rs
@@ -0,0 +1,11 @@
+use std::pin::Pin;
+
+#[cfg_attr(any(), pin_project::pin_project)]
+struct Foo<T> {
+    f: T,
+}
+
+fn main() {
+    let mut x = Foo { f: 0_u8 };
+    let _ = Pin::new(&mut x).project(); //~ ERROR E0599
+}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.stderr b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.stderr
new file mode 100644
index 0000000000..0393c143fe
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-resolve.stderr
@@ -0,0 +1,5 @@
+error[E0599]: no method named `project` found for struct `Pin<&mut Foo<u8>>` in the current scope
+  --> tests/ui/cfg/cfg_attr-resolve.rs:10:30
+   |
+10 |     let _ = Pin::new(&mut x).project(); //~ ERROR E0599
+   |                              ^^^^^^^ method not found in `Pin<&mut Foo<u8>>`
diff --git a/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.rs b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.rs
new file mode 100644
index 0000000000..1b9664b544
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.rs
@@ -0,0 +1,25 @@
+use std::pin::Pin;
+
+use pin_project::pin_project;
+
+#[cfg_attr(not(any()), pin_project)]
+struct Foo<T> {
+    #[cfg_attr(any(), pin)]
+    f: T,
+}
+
+#[cfg_attr(not(any()), pin_project)]
+struct Bar<T> {
+    #[cfg_attr(not(any()), pin)]
+    f: T,
+}
+
+fn main() {
+    let mut x = Foo { f: 0_u8 };
+    let x = Pin::new(&mut x).project();
+    let _: Pin<&mut u8> = x.f; //~ ERROR E0308
+
+    let mut x = Bar { f: 0_u8 };
+    let x = Pin::new(&mut x).project();
+    let _: &mut u8 = x.f; //~ ERROR E0308
+}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.stderr b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.stderr
new file mode 100644
index 0000000000..366d9c74cb
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/cfg_attr-type-mismatch.stderr
@@ -0,0 +1,23 @@
+error[E0308]: mismatched types
+  --> tests/ui/cfg/cfg_attr-type-mismatch.rs:20:27
+   |
+20 |     let _: Pin<&mut u8> = x.f; //~ ERROR E0308
+   |            ------------   ^^^ expected struct `Pin`, found `&mut u8`
+   |            |
+   |            expected due to this
+   |
+   = note:         expected struct `Pin<&mut u8>`
+           found mutable reference `&mut u8`
+
+error[E0308]: mismatched types
+  --> tests/ui/cfg/cfg_attr-type-mismatch.rs:24:22
+   |
+24 |     let _: &mut u8 = x.f; //~ ERROR E0308
+   |            -------   ^^^
+   |            |         |
+   |            |         expected `&mut u8`, found struct `Pin`
+   |            |         help: consider mutably borrowing here: `&mut x.f`
+   |            expected due to this
+   |
+   = note: expected mutable reference `&mut u8`
+                         found struct `Pin<&mut u8>`
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.rs b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.rs
new file mode 100644
index 0000000000..7e19952b6d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.rs
@@ -0,0 +1,15 @@
+use auxiliary_macro::hidden_repr;
+use pin_project::pin_project;
+
+#[pin_project]
+#[hidden_repr(packed)] //~ ERROR may not be used on #[repr(packed)] types
+struct S {
+    #[cfg(not(any()))]
+    #[pin]
+    f: u32,
+    #[cfg(any())]
+    #[pin]
+    f: u8,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.stderr b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.stderr
new file mode 100644
index 0000000000..4f3acc3494
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-1.stderr
@@ -0,0 +1,5 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+ --> tests/ui/cfg/packed_sneaky-span-issue-1.rs:5:15
+  |
+5 | #[hidden_repr(packed)] //~ ERROR may not be used on #[repr(packed)] types
+  |               ^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.rs b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.rs
new file mode 100644
index 0000000000..fcea76bab8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.rs
@@ -0,0 +1,15 @@
+use auxiliary_macro::hidden_repr;
+use pin_project::pin_project;
+
+#[pin_project]
+#[hidden_repr(packed)] //~ ERROR may not be used on #[repr(packed)] types
+struct S {
+    #[cfg(any())]
+    #[pin]
+    f: u32,
+    #[cfg(not(any()))]
+    #[pin]
+    f: u8,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.stderr b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.stderr
new file mode 100644
index 0000000000..cc2795ac68
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky-span-issue-2.stderr
@@ -0,0 +1,5 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+ --> tests/ui/cfg/packed_sneaky-span-issue-2.rs:5:15
+  |
+5 | #[hidden_repr(packed)] //~ ERROR may not be used on #[repr(packed)] types
+  |               ^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.rs b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.rs
new file mode 100644
index 0000000000..0b01dc90e2
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.rs
@@ -0,0 +1,12 @@
+use auxiliary_macro::hidden_repr_cfg_not_any;
+use pin_project::pin_project;
+
+// `#[hidden_repr_cfg_not_any(packed)]` generates `#[cfg_attr(not(any()), repr(packed))]`.
+#[pin_project]
+#[hidden_repr_cfg_not_any(packed)] //~ ERROR may not be used on #[repr(packed)] types
+struct S {
+    #[pin]
+    f: u32,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.stderr b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.stderr
new file mode 100644
index 0000000000..a54c2ec2d2
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/packed_sneaky.stderr
@@ -0,0 +1,5 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+ --> tests/ui/cfg/packed_sneaky.rs:6:27
+  |
+6 | #[hidden_repr_cfg_not_any(packed)] //~ ERROR may not be used on #[repr(packed)] types
+  |                           ^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/cfg/unsupported.rs b/third_party/rust/pin-project/tests/ui/cfg/unsupported.rs
new file mode 100644
index 0000000000..b950d4b828
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/unsupported.rs
@@ -0,0 +1,11 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct S {
+    //~^ ERROR may not be used on structs with zero fields
+    #[cfg(any())]
+    #[pin]
+    f: u8,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/cfg/unsupported.stderr b/third_party/rust/pin-project/tests/ui/cfg/unsupported.stderr
new file mode 100644
index 0000000000..e1c871c011
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/cfg/unsupported.stderr
@@ -0,0 +1,11 @@
+error: #[pin_project] attribute may not be used on structs with zero fields
+ --> tests/ui/cfg/unsupported.rs:4:10
+  |
+4 |   struct S {
+  |  __________^
+5 | |     //~^ ERROR may not be used on structs with zero fields
+6 | |     #[cfg(any())]
+7 | |     #[pin]
+8 | |     f: u8,
+9 | | }
+  | |_^
diff --git a/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.rs b/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.rs
new file mode 100644
index 0000000000..8985f37103
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.rs
@@ -0,0 +1,30 @@
+use pin_project::pin_project;
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T, U> Unpin for Foo<T, U> where T: Unpin {}
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T, U> Unpin for Bar<T, U> {}
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Baz<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.stderr b/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.stderr
new file mode 100644
index 0000000000..d79fbfb9e3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/not_unpin/conflict-unpin.stderr
@@ -0,0 +1,26 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Foo<_, _>`
+  --> tests/ui/not_unpin/conflict-unpin.rs:3:15
+   |
+3  | #[pin_project(!Unpin)] //~ ERROR E0119
+   |               ^^^^^^ conflicting implementation for `Foo<_, _>`
+...
+10 | impl<T, U> Unpin for Foo<T, U> where T: Unpin {}
+   | ------------------------------ first implementation here
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Bar<_, _>`
+  --> tests/ui/not_unpin/conflict-unpin.rs:12:15
+   |
+12 | #[pin_project(!Unpin)] //~ ERROR E0119
+   |               ^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+19 | impl<T, U> Unpin for Bar<T, U> {}
+   | ------------------------------ first implementation here
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Baz<_, _>`
+  --> tests/ui/not_unpin/conflict-unpin.rs:21:15
+   |
+21 | #[pin_project(!Unpin)] //~ ERROR E0119
+   |               ^^^^^^ conflicting implementation for `Baz<_, _>`
+...
+28 | impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {}
+   | -------------------------------------------- first implementation here
diff --git a/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.rs b/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.rs
new file mode 100644
index 0000000000..2c078c71ff
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.rs
@@ -0,0 +1,30 @@
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T, U> UnsafeUnpin for Foo<T, U> where T: Unpin {}
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T, U> UnsafeUnpin for Bar<T, U> {}
+
+#[pin_project(!Unpin)] //~ ERROR E0119
+struct Baz<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T: Unpin, U: Unpin> UnsafeUnpin for Baz<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.stderr b/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.stderr
new file mode 100644
index 0000000000..93f225eb75
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/not_unpin/impl-unsafe-unpin.stderr
@@ -0,0 +1,32 @@
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Foo<_, _>`
+  --> tests/ui/not_unpin/impl-unsafe-unpin.rs:3:1
+   |
+3  | #[pin_project(!Unpin)] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Foo<_, _>`
+...
+10 | unsafe impl<T, U> UnsafeUnpin for Foo<T, U> where T: Unpin {}
+   | ------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Bar<_, _>`
+  --> tests/ui/not_unpin/impl-unsafe-unpin.rs:12:1
+   |
+12 | #[pin_project(!Unpin)] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+19 | unsafe impl<T, U> UnsafeUnpin for Bar<T, U> {}
+   | ------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Baz<_, _>`
+  --> tests/ui/not_unpin/impl-unsafe-unpin.rs:21:1
+   |
+21 | #[pin_project(!Unpin)] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Baz<_, _>`
+...
+28 | unsafe impl<T: Unpin, U: Unpin> UnsafeUnpin for Baz<T, U> {}
+   | --------------------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.rs b/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.rs
new file mode 100644
index 0000000000..045e79664d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.rs
@@ -0,0 +1,20 @@
+use std::marker::PhantomPinned;
+
+use auxiliary_macro::add_pin_attr;
+use pin_project::pin_project;
+
+#[pin_project]
+#[add_pin_attr(struct)] //~ ERROR duplicate #[pin] attribute
+struct Foo {
+    #[pin]
+    f: PhantomPinned,
+}
+
+#[add_pin_attr(struct)] //~ ERROR #[pin] attribute may only be used on fields of structs or variants
+#[pin_project]
+struct Bar {
+    #[pin]
+    f: PhantomPinned,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.stderr b/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.stderr
new file mode 100644
index 0000000000..6fb88e8059
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/add-attr-to-struct.stderr
@@ -0,0 +1,15 @@
+error: duplicate #[pin] attribute
+ --> tests/ui/pin_project/add-attr-to-struct.rs:7:1
+  |
+7 | #[add_pin_attr(struct)] //~ ERROR duplicate #[pin] attribute
+  | ^^^^^^^^^^^^^^^^^^^^^^^
+  |
+  = note: this error originates in the attribute macro `add_pin_attr` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: #[pin] attribute may only be used on fields of structs or variants
+  --> tests/ui/pin_project/add-attr-to-struct.rs:13:1
+   |
+13 | #[add_pin_attr(struct)] //~ ERROR #[pin] attribute may only be used on fields of structs or variants
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the attribute macro `add_pin_attr` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.rs b/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.rs
new file mode 100644
index 0000000000..c415f9c904
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.rs
@@ -0,0 +1,23 @@
+use auxiliary_macro::add_pinned_field;
+use pin_project::pin_project;
+
+fn is_unpin<T: Unpin>() {}
+
+#[pin_project]
+#[add_pinned_field]
+struct Foo {
+    #[pin]
+    f: u32,
+}
+
+#[add_pinned_field]
+#[pin_project]
+struct Bar {
+    #[pin]
+    f: u32,
+}
+
+fn main() {
+    is_unpin::<Foo>(); //~ ERROR E0277
+    is_unpin::<Bar>(); //~ ERROR E0277
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.stderr b/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.stderr
new file mode 100644
index 0000000000..d0832cced8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/add-pinned-field.stderr
@@ -0,0 +1,52 @@
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/add-pinned-field.rs:21:5
+   |
+21 |     is_unpin::<Foo>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^^^ within `__Foo<'_>`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `__Foo<'_>`
+  --> tests/ui/pin_project/add-pinned-field.rs:8:8
+   |
+8  | struct Foo {
+   |        ^^^
+note: required because of the requirements on the impl of `Unpin` for `Foo`
+  --> tests/ui/pin_project/add-pinned-field.rs:6:1
+   |
+6  | #[pin_project]
+   | ^^^^^^^^^^^^^^
+7  | #[add_pinned_field]
+8  | struct Foo {
+   |        ^^^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/add-pinned-field.rs:4:16
+   |
+4  | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/add-pinned-field.rs:22:5
+   |
+22 |     is_unpin::<Bar>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^^^ within `__Bar<'_>`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `__Bar<'_>`
+  --> tests/ui/pin_project/add-pinned-field.rs:15:8
+   |
+15 | struct Bar {
+   |        ^^^
+note: required because of the requirements on the impl of `Unpin` for `Bar`
+  --> tests/ui/pin_project/add-pinned-field.rs:14:1
+   |
+14 | #[pin_project]
+   | ^^^^^^^^^^^^^^
+15 | struct Bar {
+   |        ^^^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/add-pinned-field.rs:4:16
+   |
+4  | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.rs b/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.rs
new file mode 100644
index 0000000000..4fdb118d06
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.rs
@@ -0,0 +1,32 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T, U> Drop for Foo<T, U> {
+    fn drop(&mut self) {}
+}
+
+#[pin_project(PinnedDrop)] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+#[pinned_drop]
+impl<T, U> PinnedDrop for Bar<T, U> {
+    fn drop(self: Pin<&mut Self>) {}
+}
+
+impl<T, U> Drop for Bar<T, U> {
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.stderr b/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.stderr
new file mode 100644
index 0000000000..4ae628da75
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/conflict-drop.stderr
@@ -0,0 +1,19 @@
+error[E0119]: conflicting implementations of trait `_::FooMustNotImplDrop` for type `Foo<_, _>`
+ --> tests/ui/pin_project/conflict-drop.rs:5:1
+  |
+5 | #[pin_project] //~ ERROR E0119
+  | ^^^^^^^^^^^^^^
+  | |
+  | first implementation here
+  | conflicting implementation for `Foo<_, _>`
+  |
+  = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `std::ops::Drop` for type `Bar<_, _>`
+  --> tests/ui/pin_project/conflict-drop.rs:16:15
+   |
+16 | #[pin_project(PinnedDrop)] //~ ERROR E0119
+   |               ^^^^^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+28 | impl<T, U> Drop for Bar<T, U> {
+   | ----------------------------- first implementation here
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.rs b/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.rs
new file mode 100644
index 0000000000..f58c45e09f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.rs
@@ -0,0 +1,37 @@
+use pin_project::pin_project;
+
+// The same implementation.
+
+#[pin_project] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+// conflicting implementations
+impl<T, U> Unpin for Foo<T, U> where T: Unpin {} // Conditional Unpin impl
+
+// The implementation that under different conditions.
+
+#[pin_project] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+// conflicting implementations
+impl<T, U> Unpin for Bar<T, U> {} // Non-conditional Unpin impl
+
+#[pin_project] //~ ERROR E0119
+struct Baz<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+// conflicting implementations
+impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {} // Conditional Unpin impl
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.stderr b/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.stderr
new file mode 100644
index 0000000000..7df5db272f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/conflict-unpin.stderr
@@ -0,0 +1,32 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Foo<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:5:1
+   |
+5  | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Foo<_, _>`
+...
+13 | impl<T, U> Unpin for Foo<T, U> where T: Unpin {} // Conditional Unpin impl
+   | ------------------------------ first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Bar<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:17:1
+   |
+17 | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+25 | impl<T, U> Unpin for Bar<T, U> {} // Non-conditional Unpin impl
+   | ------------------------------ first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Baz<_, _>`
+  --> tests/ui/pin_project/conflict-unpin.rs:27:1
+   |
+27 | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Baz<_, _>`
+...
+35 | impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {} // Conditional Unpin impl
+   | -------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.rs b/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.rs
new file mode 100644
index 0000000000..562c9b64f6
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.rs
@@ -0,0 +1,30 @@
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T, U> UnsafeUnpin for Foo<T, U> where T: Unpin {}
+
+#[pin_project] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T, U> UnsafeUnpin for Bar<T, U> {}
+
+#[pin_project] //~ ERROR E0119
+struct Baz<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+unsafe impl<T: Unpin, U: Unpin> UnsafeUnpin for Baz<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.stderr b/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.stderr
new file mode 100644
index 0000000000..9554b9b5df
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/impl-unsafe-unpin.stderr
@@ -0,0 +1,32 @@
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Foo<_, _>`
+  --> tests/ui/pin_project/impl-unsafe-unpin.rs:3:1
+   |
+3  | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Foo<_, _>`
+...
+10 | unsafe impl<T, U> UnsafeUnpin for Foo<T, U> where T: Unpin {}
+   | ------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Bar<_, _>`
+  --> tests/ui/pin_project/impl-unsafe-unpin.rs:12:1
+   |
+12 | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+19 | unsafe impl<T, U> UnsafeUnpin for Bar<T, U> {}
+   | ------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0119]: conflicting implementations of trait `_::_pin_project::UnsafeUnpin` for type `Baz<_, _>`
+  --> tests/ui/pin_project/impl-unsafe-unpin.rs:21:1
+   |
+21 | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Baz<_, _>`
+...
+28 | unsafe impl<T: Unpin, U: Unpin> UnsafeUnpin for Baz<T, U> {}
+   | --------------------------------------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.rs b/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.rs
new file mode 100644
index 0000000000..7926e61a63
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.rs
@@ -0,0 +1,30 @@
+/// Only named projected types can be imported.
+/// See visibility.rs for named projected types.
+
+mod pub_ {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    pub struct Default(());
+
+    #[pin_project(project_replace)]
+    pub struct Replace(());
+}
+#[allow(unused_imports)]
+pub mod use_ {
+    #[rustfmt::skip]
+    use crate::pub_::__DefaultProjection; //~ ERROR E0432
+    #[rustfmt::skip]
+    use crate::pub_::__DefaultProjectionRef; //~ ERROR E0432
+    #[rustfmt::skip]
+    use crate::pub_::__ReplaceProjection; //~ ERROR E0432
+    #[rustfmt::skip]
+    use crate::pub_::__ReplaceProjectionOwned; //~ ERROR E0432
+    #[rustfmt::skip]
+    use crate::pub_::__ReplaceProjectionRef; //~ ERROR E0432
+
+    // Confirm that the visibility of the original type is not changed.
+    pub use crate::pub_::{Default, Replace};
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.stderr b/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.stderr
new file mode 100644
index 0000000000..260a35a5c0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/import_unnamed.stderr
@@ -0,0 +1,29 @@
+error[E0432]: unresolved import `crate::pub_::__DefaultProjection`
+  --> tests/ui/pin_project/import_unnamed.rs:16:9
+   |
+16 |     use crate::pub_::__DefaultProjection; //~ ERROR E0432
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `__DefaultProjection` in `pub_`
+
+error[E0432]: unresolved import `crate::pub_::__DefaultProjectionRef`
+  --> tests/ui/pin_project/import_unnamed.rs:18:9
+   |
+18 |     use crate::pub_::__DefaultProjectionRef; //~ ERROR E0432
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `__DefaultProjectionRef` in `pub_`
+
+error[E0432]: unresolved import `crate::pub_::__ReplaceProjection`
+  --> tests/ui/pin_project/import_unnamed.rs:20:9
+   |
+20 |     use crate::pub_::__ReplaceProjection; //~ ERROR E0432
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `__ReplaceProjection` in `pub_`
+
+error[E0432]: unresolved import `crate::pub_::__ReplaceProjectionOwned`
+  --> tests/ui/pin_project/import_unnamed.rs:22:9
+   |
+22 |     use crate::pub_::__ReplaceProjectionOwned; //~ ERROR E0432
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `__ReplaceProjectionOwned` in `pub_`
+
+error[E0432]: unresolved import `crate::pub_::__ReplaceProjectionRef`
+  --> tests/ui/pin_project/import_unnamed.rs:24:9
+   |
+24 |     use crate::pub_::__ReplaceProjectionRef; //~ ERROR E0432
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `__ReplaceProjectionRef` in `pub_`
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/invalid.rs b/third_party/rust/pin-project/tests/ui/pin_project/invalid.rs
new file mode 100644
index 0000000000..d39a1fd4c9
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/invalid.rs
@@ -0,0 +1,280 @@
+mod pin_argument {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    struct Struct {
+        #[pin()] //~ ERROR unexpected token
+        f: (),
+    }
+
+    #[pin_project]
+    struct TupleStruct(#[pin(foo)] ()); //~ ERROR unexpected token
+
+    #[pin_project]
+    enum EnumTuple {
+        V(#[pin(foo)] ()), //~ ERROR unexpected token
+    }
+
+    #[pin_project]
+    enum EnumStruct {
+        V {
+            #[pin(foo)] //~ ERROR unexpected token
+            f: (),
+        },
+    }
+}
+
+mod pin_attribute {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    struct DuplicateStruct {
+        #[pin]
+        #[pin] //~ ERROR duplicate #[pin] attribute
+        f: (),
+    }
+
+    #[pin_project]
+    struct DuplicateTupleStruct(
+        #[pin]
+        #[pin]
+        (),
+        //~^^ ERROR duplicate #[pin] attribute
+    );
+
+    #[pin_project]
+    enum DuplicateEnumTuple {
+        V(
+            #[pin]
+            #[pin]
+            (),
+            //~^^ ERROR duplicate #[pin] attribute
+        ),
+    }
+
+    #[pin_project]
+    enum DuplicateEnumStruct {
+        V {
+            #[pin]
+            #[pin] //~ ERROR duplicate #[pin] attribute
+            f: (),
+        },
+    }
+}
+
+mod pin_item {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    #[pin] //~ ERROR may only be used on fields of structs or variants
+    struct Struct {
+        #[pin]
+        f: (),
+    }
+
+    #[pin_project]
+    enum Variant {
+        #[pin] //~ ERROR may only be used on fields of structs or variants
+        V(()),
+    }
+
+    #[pin_project]
+    #[pin] //~ ERROR may only be used on fields of structs or variants
+    enum Enum {
+        V(()),
+    }
+}
+
+mod pin_project_argument {
+    use pin_project::pin_project;
+
+    #[pin_project(Replace)] //~ ERROR `Replace` argument was removed, use `project_replace` argument instead
+    struct RemovedReplace(#[pin] ());
+
+    #[pin_project(UnsafeUnpin,,)] //~ ERROR expected identifier
+    struct Unexpected1(#[pin] ());
+
+    #[pin_project(Foo)] //~ ERROR unexpected argument
+    struct Unexpected2(#[pin] ());
+
+    #[pin_project(,UnsafeUnpin)] //~ ERROR expected identifier
+    struct Unexpected3(#[pin] ());
+
+    #[pin_project()] // Ok
+    struct Unexpected4(#[pin] ());
+
+    #[pin_project(PinnedDrop PinnedDrop)] //~ ERROR expected `,`
+    struct Unexpected5(#[pin] ());
+
+    #[pin_project(PinnedDrop, PinnedDrop)] //~ ERROR duplicate `PinnedDrop` argument
+    struct DuplicatePinnedDrop(#[pin] ());
+
+    #[pin_project(UnsafeUnpin, UnsafeUnpin)] //~ ERROR duplicate `UnsafeUnpin` argument
+    struct DuplicateUnsafeUnpin(#[pin] ());
+
+    #[pin_project(!Unpin, !Unpin)] //~ ERROR duplicate `!Unpin` argument
+    struct DuplicateNotUnpin(#[pin] ());
+
+    #[pin_project(PinnedDrop, UnsafeUnpin, UnsafeUnpin)] //~ ERROR duplicate `UnsafeUnpin` argument
+    struct Duplicate3(#[pin] ());
+
+    #[pin_project(PinnedDrop, UnsafeUnpin, PinnedDrop, UnsafeUnpin)] //~ ERROR duplicate `PinnedDrop` argument
+    struct Duplicate4(#[pin] ());
+
+    #[pin_project(project = A, project = B)] //~ ERROR duplicate `project` argument
+    struct DuplicateProject(#[pin] ());
+
+    #[pin_project(project = A, project_ref = A, project = B)] //~ ERROR duplicate `project` argument
+    struct DuplicateProject2(#[pin] ());
+
+    #[pin_project(project_ref = A, project_ref = B)] //~ ERROR duplicate `project_ref` argument
+    struct DuplicateProjectRef(#[pin] ());
+
+    #[pin_project(project_replace = A, project_replace = B)] //~ ERROR duplicate `project_replace` argument
+    struct DuplicateProjectReplace1(#[pin] ());
+
+    #[pin_project(project_replace, project_replace = B)] //~ ERROR duplicate `project_replace` argument
+    struct DuplicateProjectReplace2(#[pin] ());
+
+    #[pin_project(project_replace = A, project_replace)] //~ ERROR duplicate `project_replace` argument
+    struct DuplicateProjectReplace3(#[pin] ());
+
+    #[pin_project(project_replace = A)] // Ok
+    struct ProjectReplaceWithoutReplace(#[pin] ());
+
+    #[pin_project(PinnedDrop, project_replace)] //~ ERROR arguments `PinnedDrop` and `project_replace` are mutually exclusive
+    struct PinnedDropWithProjectReplace1(#[pin] ());
+
+    #[pin_project(project_replace, UnsafeUnpin, PinnedDrop)] //~ ERROR arguments `PinnedDrop` and `project_replace` are mutually exclusive
+    struct PinnedDropWithProjectReplace2(#[pin] ());
+
+    #[pin_project(UnsafeUnpin, !Unpin)] //~ ERROR arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+    struct UnsafeUnpinWithNotUnpin1(#[pin] ());
+
+    #[pin_project(!Unpin, PinnedDrop, UnsafeUnpin)] //~ ERROR arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+    struct UnsafeUnpinWithNotUnpin2(#[pin] ());
+
+    #[pin_project(!)] //~ ERROR expected `!Unpin`, found `!`
+    struct NotUnpin1(#[pin] ());
+
+    #[pin_project(Unpin)] //~ ERROR unexpected argument
+    struct NotUnpin2(#[pin] ());
+
+    #[pin_project(project)] //~ ERROR expected `project = <identifier>`, found `project`
+    struct Project1(#[pin] ());
+
+    #[pin_project(project = )] //~ ERROR expected `project = <identifier>`, found `project =`
+    struct Project2(#[pin] ());
+
+    #[pin_project(project = !)] //~ ERROR expected identifier
+    struct Project3(#[pin] ());
+
+    #[pin_project(project_ref)] //~ ERROR expected `project_ref = <identifier>`, found `project_ref`
+    struct ProjectRef1(#[pin] ());
+
+    #[pin_project(project_ref = )] //~ ERROR expected `project_ref = <identifier>`, found `project_ref =`
+    struct ProjectRef2(#[pin] ());
+
+    #[pin_project(project_ref = !)] //~ ERROR expected identifier
+    struct ProjectRef3(#[pin] ());
+
+    #[pin_project(project_replace)] // Ok
+    struct ProjectReplace1(#[pin] ());
+
+    #[pin_project(project_replace = )] //~ ERROR expected `project_replace = <identifier>`, found `project_replace =`
+    struct ProjectReplace2(#[pin] ());
+
+    #[pin_project(project_replace = !)] //~ ERROR expected identifier
+    struct ProjectReplace3(#[pin] ());
+
+    #[pin_project(project_replace)] //~ ERROR `project_replace` argument requires a value when used on enums
+    enum ProjectReplaceEnum {
+        V(#[pin] ()),
+    }
+}
+
+mod pin_project_conflict_naming {
+    use pin_project::pin_project;
+
+    #[pin_project(project = OrigAndProj)] //~ ERROR name `OrigAndProj` is the same as the original type name
+    struct OrigAndProj(#[pin] ());
+
+    #[pin_project(project_ref = OrigAndProjRef)] //~ ERROR name `OrigAndProjRef` is the same as the original type name
+    struct OrigAndProjRef(#[pin] ());
+
+    #[pin_project(project_replace = OrigAndProjOwn)] //~ ERROR name `OrigAndProjOwn` is the same as the original type name
+    struct OrigAndProjOwn(#[pin] ());
+
+    #[pin_project(project = A, project_ref = A)] //~ ERROR name `A` is already specified by `project` argument
+    struct ProjAndProjRef(#[pin] ());
+
+    #[pin_project(project = A, project_replace = A)] //~ ERROR name `A` is already specified by `project` argument
+    struct ProjAndProjOwn(#[pin] ());
+
+    #[pin_project(project_ref = A, project_replace = A)] //~ ERROR name `A` is already specified by `project_ref` argument
+    struct ProjRefAndProjOwn(#[pin] ());
+}
+
+mod pin_project_attribute {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    #[pin_project] //~ ERROR duplicate #[pin_project] attribute
+    struct Duplicate(#[pin] ());
+}
+
+mod pin_project_item {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    struct Struct {} //~ ERROR may not be used on structs with zero fields
+
+    #[pin_project]
+    struct TupleStruct(); //~ ERROR may not be used on structs with zero fields
+
+    #[pin_project]
+    struct UnitStruct; //~ ERROR may not be used on structs with zero fields
+
+    #[pin_project]
+    enum EnumEmpty {} //~ ERROR may not be used on enums without variants
+
+    #[pin_project]
+    enum EnumDiscriminant {
+        V = 2, //~ ERROR may not be used on enums with discriminants
+    }
+
+    #[pin_project]
+    enum EnumZeroFields {
+        Unit, //~ ERROR may not be used on enums with zero fields
+        Tuple(),
+        Struct {},
+    }
+
+    #[pin_project]
+    union Union {
+        //~^ ERROR may only be used on structs or enums
+        f: (),
+    }
+
+    #[pin_project]
+    impl Impl {} //~ ERROR may only be used on structs or enums
+}
+
+// #[repr(packed)] is always detected first, even on unsupported structs.
+mod pin_project_item_packed {
+    use pin_project::pin_project;
+
+    #[pin_project]
+    #[repr(packed)]
+    struct Struct {} //~ ERROR may not be used on #[repr(packed)] types
+
+    #[pin_project]
+    #[repr(packed)]
+    struct TupleStruct(); //~ ERROR may not be used on #[repr(packed)] types
+
+    #[pin_project]
+    #[repr(packed)]
+    struct UnitStruct; //~ ERROR may not be used on #[repr(packed)] types
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/invalid.stderr b/third_party/rust/pin-project/tests/ui/pin_project/invalid.stderr
new file mode 100644
index 0000000000..c43d363de8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/invalid.stderr
@@ -0,0 +1,364 @@
+error: unexpected token: `()`
+ --> tests/ui/pin_project/invalid.rs:6:14
+  |
+6 |         #[pin()] //~ ERROR unexpected token
+  |              ^^
+
+error: unexpected token: `(foo)`
+  --> tests/ui/pin_project/invalid.rs:11:29
+   |
+11 |     struct TupleStruct(#[pin(foo)] ()); //~ ERROR unexpected token
+   |                             ^^^^^
+
+error: unexpected token: `(foo)`
+  --> tests/ui/pin_project/invalid.rs:15:16
+   |
+15 |         V(#[pin(foo)] ()), //~ ERROR unexpected token
+   |                ^^^^^
+
+error: unexpected token: `(foo)`
+  --> tests/ui/pin_project/invalid.rs:21:18
+   |
+21 |             #[pin(foo)] //~ ERROR unexpected token
+   |                  ^^^^^
+
+error: duplicate #[pin] attribute
+  --> tests/ui/pin_project/invalid.rs:33:9
+   |
+33 |         #[pin] //~ ERROR duplicate #[pin] attribute
+   |         ^^^^^^
+
+error: duplicate #[pin] attribute
+  --> tests/ui/pin_project/invalid.rs:40:9
+   |
+40 |         #[pin]
+   |         ^^^^^^
+
+error: duplicate #[pin] attribute
+  --> tests/ui/pin_project/invalid.rs:49:13
+   |
+49 |             #[pin]
+   |             ^^^^^^
+
+error: duplicate #[pin] attribute
+  --> tests/ui/pin_project/invalid.rs:59:13
+   |
+59 |             #[pin] //~ ERROR duplicate #[pin] attribute
+   |             ^^^^^^
+
+error: #[pin] attribute may only be used on fields of structs or variants
+  --> tests/ui/pin_project/invalid.rs:69:5
+   |
+69 |     #[pin] //~ ERROR may only be used on fields of structs or variants
+   |     ^^^^^^
+
+error: #[pin] attribute may only be used on fields of structs or variants
+  --> tests/ui/pin_project/invalid.rs:77:9
+   |
+77 |         #[pin] //~ ERROR may only be used on fields of structs or variants
+   |         ^^^^^^
+
+error: #[pin] attribute may only be used on fields of structs or variants
+  --> tests/ui/pin_project/invalid.rs:82:5
+   |
+82 |     #[pin] //~ ERROR may only be used on fields of structs or variants
+   |     ^^^^^^
+
+error: `Replace` argument was removed, use `project_replace` argument instead
+  --> tests/ui/pin_project/invalid.rs:91:19
+   |
+91 |     #[pin_project(Replace)] //~ ERROR `Replace` argument was removed, use `project_replace` argument instead
+   |                   ^^^^^^^
+
+error: expected identifier
+  --> tests/ui/pin_project/invalid.rs:94:31
+   |
+94 |     #[pin_project(UnsafeUnpin,,)] //~ ERROR expected identifier
+   |                               ^
+
+error: unexpected argument: Foo
+  --> tests/ui/pin_project/invalid.rs:97:19
+   |
+97 |     #[pin_project(Foo)] //~ ERROR unexpected argument
+   |                   ^^^
+
+error: expected identifier
+   --> tests/ui/pin_project/invalid.rs:100:19
+    |
+100 |     #[pin_project(,UnsafeUnpin)] //~ ERROR expected identifier
+    |                   ^
+
+error: expected `,`
+   --> tests/ui/pin_project/invalid.rs:106:30
+    |
+106 |     #[pin_project(PinnedDrop PinnedDrop)] //~ ERROR expected `,`
+    |                              ^^^^^^^^^^
+
+error: duplicate `PinnedDrop` argument
+   --> tests/ui/pin_project/invalid.rs:109:31
+    |
+109 |     #[pin_project(PinnedDrop, PinnedDrop)] //~ ERROR duplicate `PinnedDrop` argument
+    |                               ^^^^^^^^^^
+
+error: duplicate `UnsafeUnpin` argument
+   --> tests/ui/pin_project/invalid.rs:112:32
+    |
+112 |     #[pin_project(UnsafeUnpin, UnsafeUnpin)] //~ ERROR duplicate `UnsafeUnpin` argument
+    |                                ^^^^^^^^^^^
+
+error: duplicate `!Unpin` argument
+   --> tests/ui/pin_project/invalid.rs:115:27
+    |
+115 |     #[pin_project(!Unpin, !Unpin)] //~ ERROR duplicate `!Unpin` argument
+    |                           ^^^^^^
+
+error: duplicate `UnsafeUnpin` argument
+   --> tests/ui/pin_project/invalid.rs:118:44
+    |
+118 |     #[pin_project(PinnedDrop, UnsafeUnpin, UnsafeUnpin)] //~ ERROR duplicate `UnsafeUnpin` argument
+    |                                            ^^^^^^^^^^^
+
+error: duplicate `PinnedDrop` argument
+   --> tests/ui/pin_project/invalid.rs:121:44
+    |
+121 |     #[pin_project(PinnedDrop, UnsafeUnpin, PinnedDrop, UnsafeUnpin)] //~ ERROR duplicate `PinnedDrop` argument
+    |                                            ^^^^^^^^^^
+
+error: duplicate `project` argument
+   --> tests/ui/pin_project/invalid.rs:124:32
+    |
+124 |     #[pin_project(project = A, project = B)] //~ ERROR duplicate `project` argument
+    |                                ^^^^^^^^^^^
+
+error: duplicate `project` argument
+   --> tests/ui/pin_project/invalid.rs:127:49
+    |
+127 |     #[pin_project(project = A, project_ref = A, project = B)] //~ ERROR duplicate `project` argument
+    |                                                 ^^^^^^^^^^^
+
+error: duplicate `project_ref` argument
+   --> tests/ui/pin_project/invalid.rs:130:36
+    |
+130 |     #[pin_project(project_ref = A, project_ref = B)] //~ ERROR duplicate `project_ref` argument
+    |                                    ^^^^^^^^^^^^^^^
+
+error: duplicate `project_replace` argument
+   --> tests/ui/pin_project/invalid.rs:133:40
+    |
+133 |     #[pin_project(project_replace = A, project_replace = B)] //~ ERROR duplicate `project_replace` argument
+    |                                        ^^^^^^^^^^^^^^^^^^^
+
+error: duplicate `project_replace` argument
+   --> tests/ui/pin_project/invalid.rs:136:36
+    |
+136 |     #[pin_project(project_replace, project_replace = B)] //~ ERROR duplicate `project_replace` argument
+    |                                    ^^^^^^^^^^^^^^^^^^^
+
+error: duplicate `project_replace` argument
+   --> tests/ui/pin_project/invalid.rs:139:40
+    |
+139 |     #[pin_project(project_replace = A, project_replace)] //~ ERROR duplicate `project_replace` argument
+    |                                        ^^^^^^^^^^^^^^^
+
+error: arguments `PinnedDrop` and `project_replace` are mutually exclusive
+   --> tests/ui/pin_project/invalid.rs:145:19
+    |
+145 |     #[pin_project(PinnedDrop, project_replace)] //~ ERROR arguments `PinnedDrop` and `project_replace` are mutually exclusive
+    |                   ^^^^^^^^^^
+
+error: arguments `PinnedDrop` and `project_replace` are mutually exclusive
+   --> tests/ui/pin_project/invalid.rs:148:49
+    |
+148 |     #[pin_project(project_replace, UnsafeUnpin, PinnedDrop)] //~ ERROR arguments `PinnedDrop` and `project_replace` are mutually exclusive
+    |                                                 ^^^^^^^^^^
+
+error: arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+   --> tests/ui/pin_project/invalid.rs:151:19
+    |
+151 |     #[pin_project(UnsafeUnpin, !Unpin)] //~ ERROR arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+    |                   ^^^^^^^^^^^
+
+error: arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+   --> tests/ui/pin_project/invalid.rs:154:39
+    |
+154 |     #[pin_project(!Unpin, PinnedDrop, UnsafeUnpin)] //~ ERROR arguments `UnsafeUnpin` and `!Unpin` are mutually exclusive
+    |                                       ^^^^^^^^^^^
+
+error: expected `!Unpin`, found `!`
+   --> tests/ui/pin_project/invalid.rs:157:19
+    |
+157 |     #[pin_project(!)] //~ ERROR expected `!Unpin`, found `!`
+    |                   ^
+
+error: unexpected argument: Unpin
+   --> tests/ui/pin_project/invalid.rs:160:19
+    |
+160 |     #[pin_project(Unpin)] //~ ERROR unexpected argument
+    |                   ^^^^^
+
+error: expected `project = <identifier>`, found `project`
+   --> tests/ui/pin_project/invalid.rs:163:19
+    |
+163 |     #[pin_project(project)] //~ ERROR expected `project = <identifier>`, found `project`
+    |                   ^^^^^^^
+
+error: expected `project = <identifier>`, found `project =`
+   --> tests/ui/pin_project/invalid.rs:166:19
+    |
+166 |     #[pin_project(project = )] //~ ERROR expected `project = <identifier>`, found `project =`
+    |                   ^^^^^^^^^
+
+error: expected identifier
+   --> tests/ui/pin_project/invalid.rs:169:29
+    |
+169 |     #[pin_project(project = !)] //~ ERROR expected identifier
+    |                             ^
+
+error: expected `project_ref = <identifier>`, found `project_ref`
+   --> tests/ui/pin_project/invalid.rs:172:19
+    |
+172 |     #[pin_project(project_ref)] //~ ERROR expected `project_ref = <identifier>`, found `project_ref`
+    |                   ^^^^^^^^^^^
+
+error: expected `project_ref = <identifier>`, found `project_ref =`
+   --> tests/ui/pin_project/invalid.rs:175:19
+    |
+175 |     #[pin_project(project_ref = )] //~ ERROR expected `project_ref = <identifier>`, found `project_ref =`
+    |                   ^^^^^^^^^^^^^
+
+error: expected identifier
+   --> tests/ui/pin_project/invalid.rs:178:33
+    |
+178 |     #[pin_project(project_ref = !)] //~ ERROR expected identifier
+    |                                 ^
+
+error: expected `project_replace = <identifier>`, found `project_replace =`
+   --> tests/ui/pin_project/invalid.rs:184:19
+    |
+184 |     #[pin_project(project_replace = )] //~ ERROR expected `project_replace = <identifier>`, found `project_replace =`
+    |                   ^^^^^^^^^^^^^^^^^
+
+error: expected identifier
+   --> tests/ui/pin_project/invalid.rs:187:37
+    |
+187 |     #[pin_project(project_replace = !)] //~ ERROR expected identifier
+    |                                     ^
+
+error: `project_replace` argument requires a value when used on enums
+   --> tests/ui/pin_project/invalid.rs:190:19
+    |
+190 |     #[pin_project(project_replace)] //~ ERROR `project_replace` argument requires a value when used on enums
+    |                   ^^^^^^^^^^^^^^^
+
+error: name `OrigAndProj` is the same as the original type name
+   --> tests/ui/pin_project/invalid.rs:199:29
+    |
+199 |     #[pin_project(project = OrigAndProj)] //~ ERROR name `OrigAndProj` is the same as the original type name
+    |                             ^^^^^^^^^^^
+
+error: name `OrigAndProjRef` is the same as the original type name
+   --> tests/ui/pin_project/invalid.rs:202:33
+    |
+202 |     #[pin_project(project_ref = OrigAndProjRef)] //~ ERROR name `OrigAndProjRef` is the same as the original type name
+    |                                 ^^^^^^^^^^^^^^
+
+error: name `OrigAndProjOwn` is the same as the original type name
+   --> tests/ui/pin_project/invalid.rs:205:37
+    |
+205 |     #[pin_project(project_replace = OrigAndProjOwn)] //~ ERROR name `OrigAndProjOwn` is the same as the original type name
+    |                                     ^^^^^^^^^^^^^^
+
+error: name `A` is already specified by `project` argument
+   --> tests/ui/pin_project/invalid.rs:208:46
+    |
+208 |     #[pin_project(project = A, project_ref = A)] //~ ERROR name `A` is already specified by `project` argument
+    |                                              ^
+
+error: name `A` is already specified by `project` argument
+   --> tests/ui/pin_project/invalid.rs:211:50
+    |
+211 |     #[pin_project(project = A, project_replace = A)] //~ ERROR name `A` is already specified by `project` argument
+    |                                                  ^
+
+error: name `A` is already specified by `project_ref` argument
+   --> tests/ui/pin_project/invalid.rs:214:54
+    |
+214 |     #[pin_project(project_ref = A, project_replace = A)] //~ ERROR name `A` is already specified by `project_ref` argument
+    |                                                      ^
+
+error: duplicate #[pin_project] attribute
+   --> tests/ui/pin_project/invalid.rs:222:5
+    |
+222 |     #[pin_project] //~ ERROR duplicate #[pin_project] attribute
+    |     ^^^^^^^^^^^^^^
+
+error: #[pin_project] attribute may not be used on structs with zero fields
+   --> tests/ui/pin_project/invalid.rs:230:19
+    |
+230 |     struct Struct {} //~ ERROR may not be used on structs with zero fields
+    |                   ^^
+
+error: #[pin_project] attribute may not be used on structs with zero fields
+   --> tests/ui/pin_project/invalid.rs:233:23
+    |
+233 |     struct TupleStruct(); //~ ERROR may not be used on structs with zero fields
+    |                       ^^
+
+error: #[pin_project] attribute may not be used on structs with zero fields
+   --> tests/ui/pin_project/invalid.rs:236:12
+    |
+236 |     struct UnitStruct; //~ ERROR may not be used on structs with zero fields
+    |            ^^^^^^^^^^
+
+error: #[pin_project] attribute may not be used on enums without variants
+   --> tests/ui/pin_project/invalid.rs:239:20
+    |
+239 |     enum EnumEmpty {} //~ ERROR may not be used on enums without variants
+    |                    ^^
+
+error: #[pin_project] attribute may not be used on enums with discriminants
+   --> tests/ui/pin_project/invalid.rs:243:13
+    |
+243 |         V = 2, //~ ERROR may not be used on enums with discriminants
+    |             ^
+
+error: #[pin_project] attribute may not be used on enums with zero fields
+   --> tests/ui/pin_project/invalid.rs:248:9
+    |
+248 | /         Unit, //~ ERROR may not be used on enums with zero fields
+249 | |         Tuple(),
+250 | |         Struct {},
+    | |__________________^
+
+error: #[pin_project] attribute may only be used on structs or enums
+   --> tests/ui/pin_project/invalid.rs:254:5
+    |
+254 | /     union Union {
+255 | |         //~^ ERROR may only be used on structs or enums
+256 | |         f: (),
+257 | |     }
+    | |_____^
+
+error: #[pin_project] attribute may only be used on structs or enums
+   --> tests/ui/pin_project/invalid.rs:260:5
+    |
+260 |     impl Impl {} //~ ERROR may only be used on structs or enums
+    |     ^^^^^^^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+   --> tests/ui/pin_project/invalid.rs:268:12
+    |
+268 |     #[repr(packed)]
+    |            ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+   --> tests/ui/pin_project/invalid.rs:272:12
+    |
+272 |     #[repr(packed)]
+    |            ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+   --> tests/ui/pin_project/invalid.rs:276:12
+    |
+276 |     #[repr(packed)]
+    |            ^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.rs b/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.rs
new file mode 100644
index 0000000000..abfd5d1344
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.rs
@@ -0,0 +1,19 @@
+use std::marker::PhantomPinned;
+
+use pin_project::pin_project;
+
+#[pin_project]
+struct S<T> {
+    #[pin]
+    f: T,
+}
+
+struct __S {}
+
+impl Unpin for __S {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<S<PhantomPinned>>(); //~ ERROR E0277
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.stderr b/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.stderr
new file mode 100644
index 0000000000..1bd200d9c8
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/overlapping_unpin_struct.stderr
@@ -0,0 +1,25 @@
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:18:5
+   |
+18 |     is_unpin::<S<PhantomPinned>>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ within `_::__S<'_, PhantomPinned>`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `_::__S<'_, PhantomPinned>`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:6:8
+   |
+6  | struct S<T> {
+   |        ^
+note: required because of the requirements on the impl of `Unpin` for `S<PhantomPinned>`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:5:1
+   |
+5  | #[pin_project]
+   | ^^^^^^^^^^^^^^
+6  | struct S<T> {
+   |        ^^^^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/overlapping_unpin_struct.rs:15:16
+   |
+15 | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.rs b/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.rs
new file mode 100644
index 0000000000..890fd5b8de
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.rs
@@ -0,0 +1,32 @@
+// https://discord.com/channels/273534239310479360/512792629516173323/870075511009857617
+
+extern crate pin_project as pin_project_orig;
+extern crate self as pin_project;
+
+pub use ::pin_project_orig::*;
+mod __private {
+    pub use ::pin_project_orig::__private::*;
+    pub trait Drop {}
+}
+
+use std::{marker::PhantomPinned, mem};
+
+#[pin_project] //~ ERROR conflicting implementations of trait `_::FooMustNotImplDrop`
+struct S {
+    #[pin]
+    f: (u8, PhantomPinned),
+}
+
+impl Drop for S {
+    fn drop(&mut self) {
+        let prev = &self.f.0 as *const _ as usize;
+        let moved = mem::take(&mut self.f); // move pinned field
+        let moved = &moved.0 as *const _ as usize;
+        assert_eq!(prev, moved); // panic
+    }
+}
+
+fn main() {
+    let mut x = Box::pin(S { f: (1, PhantomPinned) });
+    let _f = x.as_mut().project().f; // first mutable access
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.stderr b/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.stderr
new file mode 100644
index 0000000000..8a3fb9b61a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/override-priv-mod.stderr
@@ -0,0 +1,10 @@
+error[E0119]: conflicting implementations of trait `_::SMustNotImplDrop` for type `S`
+  --> tests/ui/pin_project/override-priv-mod.rs:14:1
+   |
+14 | #[pin_project] //~ ERROR conflicting implementations of trait `_::FooMustNotImplDrop`
+   | ^^^^^^^^^^^^^^
+   | |
+   | first implementation here
+   | conflicting implementation for `S`
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.rs
new file mode 100644
index 0000000000..023c08d14f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.rs
@@ -0,0 +1,24 @@
+use pin_project::pin_project;
+
+// #[repr(packed)] cannot be apply on enums and will be rejected by rustc.
+// However, we should not rely on the behavior of rustc that rejects this.
+// https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+
+#[repr(packed)] //~ ERROR E0517
+enum E1 {
+    V(()),
+}
+
+#[pin_project]
+#[repr(packed)] //~ ERROR E0517
+enum E2 {
+    V(()),
+}
+
+#[repr(packed)] //~ ERROR E0517
+#[pin_project]
+enum E3 {
+    V(()),
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.stderr
new file mode 100644
index 0000000000..1872211206
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed-enum.stderr
@@ -0,0 +1,42 @@
+error: #[repr(packed)] attribute should be applied to a struct or union
+  --> tests/ui/pin_project/packed-enum.rs:13:8
+   |
+13 | #[repr(packed)] //~ ERROR E0517
+   |        ^^^^^^
+
+error: #[repr(packed)] attribute should be applied to a struct or union
+  --> tests/ui/pin_project/packed-enum.rs:18:8
+   |
+18 | #[repr(packed)] //~ ERROR E0517
+   |        ^^^^^^
+
+error[E0517]: attribute should be applied to a struct or union
+  --> tests/ui/pin_project/packed-enum.rs:7:8
+   |
+7  |   #[repr(packed)] //~ ERROR E0517
+   |          ^^^^^^
+8  | / enum E1 {
+9  | |     V(()),
+10 | | }
+   | |_- not a struct or union
+
+error[E0517]: attribute should be applied to a struct or union
+  --> tests/ui/pin_project/packed-enum.rs:13:8
+   |
+13 |   #[repr(packed)] //~ ERROR E0517
+   |          ^^^^^^
+14 | / enum E2 {
+15 | |     V(()),
+16 | | }
+   | |_- not a struct or union
+
+error[E0517]: attribute should be applied to a struct or union
+  --> tests/ui/pin_project/packed-enum.rs:18:8
+   |
+18 |   #[repr(packed)] //~ ERROR E0517
+   |          ^^^^^^
+19 |   #[pin_project]
+20 | / enum E3 {
+21 | |     V(()),
+22 | | }
+   | |_- not a struct or union
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.rs
new file mode 100644
index 0000000000..dedc4030fa
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.rs
@@ -0,0 +1,27 @@
+use pin_project::pin_project;
+
+// #[repr(packed = "")] is not valid format of #[repr(packed)] and will be
+// rejected by rustc.
+// However, we should not rely on the behavior of rustc that rejects this.
+// https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+
+// https://github.com/taiki-e/pin-project/pull/324#discussion_r612388001
+// https://github.com/rust-lang/rust/issues/83921
+// #[repr(packed = "")] //~ ERROR E0552
+// struct S1 {
+//     f: (),
+// }
+
+#[pin_project]
+#[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+struct S2 {
+    f: (),
+}
+
+#[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+#[pin_project]
+struct S3 {
+    f: (),
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.stderr
new file mode 100644
index 0000000000..d8b2194713
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed-name-value.stderr
@@ -0,0 +1,23 @@
+error: #[repr(packed)] attribute should not be name-value pair
+  --> tests/ui/pin_project/packed-name-value.rs:16:8
+   |
+16 | #[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+   |        ^^^^^^^^^^^
+
+error: #[repr(packed)] attribute should not be name-value pair
+  --> tests/ui/pin_project/packed-name-value.rs:21:8
+   |
+21 | #[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+   |        ^^^^^^^^^^^
+
+error[E0693]: incorrect `repr(packed)` attribute format
+  --> tests/ui/pin_project/packed-name-value.rs:16:8
+   |
+16 | #[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+   |        ^^^^^^^^^^^ help: use parentheses instead: `packed()`
+
+error[E0693]: incorrect `repr(packed)` attribute format
+  --> tests/ui/pin_project/packed-name-value.rs:21:8
+   |
+21 | #[repr(packed = "")] //~ ERROR attribute should not be name-value pair
+   |        ^^^^^^^^^^^ help: use parentheses instead: `packed()`
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed.rs
new file mode 100644
index 0000000000..dd3ebfd638
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed.rs
@@ -0,0 +1,33 @@
+use pin_project::pin_project;
+
+#[pin_project]
+#[repr(packed, C)] //~ ERROR may not be used on #[repr(packed)] types
+struct Packed1 {
+    #[pin]
+    f: u8,
+}
+
+// Test putting 'repr' before the 'pin_project' attribute
+#[repr(packed, C)] //~ ERROR may not be used on #[repr(packed)] types
+#[pin_project]
+struct Packed2 {
+    #[pin]
+    f: u8,
+}
+
+#[pin_project]
+#[repr(packed(2))] //~ ERROR may not be used on #[repr(packed)] types
+struct PackedN1 {
+    #[pin]
+    f: u32,
+}
+
+// Test putting 'repr' before the 'pin_project' attribute
+#[repr(packed(2))] //~ ERROR may not be used on #[repr(packed)] types
+#[pin_project]
+struct PackedN2 {
+    #[pin]
+    f: u32,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed.stderr
new file mode 100644
index 0000000000..25ea5f43e4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed.stderr
@@ -0,0 +1,23 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+ --> tests/ui/pin_project/packed.rs:4:8
+  |
+4 | #[repr(packed, C)] //~ ERROR may not be used on #[repr(packed)] types
+  |        ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed.rs:11:8
+   |
+11 | #[repr(packed, C)] //~ ERROR may not be used on #[repr(packed)] types
+   |        ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed.rs:19:8
+   |
+19 | #[repr(packed(2))] //~ ERROR may not be used on #[repr(packed)] types
+   |        ^^^^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed.rs:26:8
+   |
+26 | #[repr(packed(2))] //~ ERROR may not be used on #[repr(packed)] types
+   |        ^^^^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.rs
new file mode 100644
index 0000000000..83a46122cc
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.rs
@@ -0,0 +1,41 @@
+use std::pin::Pin;
+
+use auxiliary_macro::{hidden_repr, hidden_repr2};
+use pin_project::{pin_project, pinned_drop, UnsafeUnpin};
+
+#[pin_project] //~ ERROR may not be used on #[repr(packed)] types
+#[hidden_repr(packed)]
+struct A {
+    #[pin]
+    f: u32,
+}
+
+#[hidden_repr2]
+#[pin_project] //~ ERROR may not be used on #[repr(packed)] types
+struct B {
+    #[pin]
+    f: u32,
+}
+
+#[pin_project(UnsafeUnpin)] //~ ERROR may not be used on #[repr(packed)] types
+#[hidden_repr(packed)]
+struct C {
+    #[pin]
+    f: u32,
+}
+
+unsafe impl UnsafeUnpin for C {}
+
+#[pin_project(PinnedDrop)] //~ ERROR may not be used on #[repr(packed)] types
+#[hidden_repr(packed)]
+struct D {
+    #[pin]
+    f: u32,
+}
+
+#[pinned_drop]
+impl PinnedDrop for D {
+    fn drop(self: Pin<&mut Self>) {}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.stderr
new file mode 100644
index 0000000000..0746e1a21c
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-1.stderr
@@ -0,0 +1,25 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+ --> tests/ui/pin_project/packed_sneaky-1.rs:7:15
+  |
+7 | #[hidden_repr(packed)]
+  |               ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed_sneaky-1.rs:13:1
+   |
+13 | #[hidden_repr2]
+   | ^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the attribute macro `hidden_repr2` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed_sneaky-1.rs:21:15
+   |
+21 | #[hidden_repr(packed)]
+   |               ^^^^^^
+
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed_sneaky-1.rs:30:15
+   |
+30 | #[hidden_repr(packed)]
+   |               ^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.rs
new file mode 100644
index 0000000000..b098358e6f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.rs
@@ -0,0 +1,12 @@
+use auxiliary_macro::hidden_repr_macro;
+use pin_project::pin_project;
+
+hidden_repr_macro! { //~ ERROR may not be used on #[repr(packed)] types
+    #[pin_project]
+    struct B {
+        #[pin]
+        f: u32,
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.stderr
new file mode 100644
index 0000000000..d643052fda
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-2.stderr
@@ -0,0 +1,13 @@
+error: #[pin_project] attribute may not be used on #[repr(packed)] types
+  --> tests/ui/pin_project/packed_sneaky-2.rs:4:1
+   |
+4  | / hidden_repr_macro! { //~ ERROR may not be used on #[repr(packed)] types
+5  | |     #[pin_project]
+6  | |     struct B {
+7  | |         #[pin]
+8  | |         f: u32,
+9  | |     }
+10 | | }
+   | |_^
+   |
+   = note: this error originates in the macro `hidden_repr_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.rs
new file mode 100644
index 0000000000..d3f00f3d23
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.rs
@@ -0,0 +1,32 @@
+use auxiliary_macro::{hidden_repr_macro, HiddenRepr};
+use pin_project::pin_project;
+
+hidden_repr_macro! {} //~ ERROR expected item after attributes
+#[pin_project]
+struct S1 {
+    #[pin]
+    f: u32,
+}
+
+macro_rules! hidden_repr_macro2 {
+    () => {
+        #[repr(packed)] //~ ERROR expected item after attributes
+    };
+}
+
+hidden_repr_macro2! {}
+#[pin_project]
+struct S2 {
+    #[pin]
+    f: u32,
+}
+
+#[derive(HiddenRepr)] //~ ERROR expected item after attributes
+struct S3 {}
+#[pin_project]
+struct S4 {
+    #[pin]
+    f: u32,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.stderr
new file mode 100644
index 0000000000..c97f18b75a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-3.stderr
@@ -0,0 +1,32 @@
+error: expected item after attributes
+ --> tests/ui/pin_project/packed_sneaky-3.rs:4:1
+  |
+4 | hidden_repr_macro! {} //~ ERROR expected item after attributes
+  | ^^^^^^^^^^^^^^^^^^^^^
+  |
+  = note: this error originates in the macro `hidden_repr_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected item after attributes
+  --> tests/ui/pin_project/packed_sneaky-3.rs:13:9
+   |
+13 |         #[repr(packed)] //~ ERROR expected item after attributes
+   |         ^^^^^^^^^^^^^^^
+...
+17 | hidden_repr_macro2! {}
+   | ---------------------- in this macro invocation
+   |
+   = note: this error originates in the macro `hidden_repr_macro2` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: expected item after attributes
+  --> tests/ui/pin_project/packed_sneaky-3.rs:24:10
+   |
+24 | #[derive(HiddenRepr)] //~ ERROR expected item after attributes
+   |          ^^^^^^^^^^
+   |
+   = note: this error originates in the derive macro `HiddenRepr` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: proc-macro derive produced unparseable tokens
+  --> tests/ui/pin_project/packed_sneaky-3.rs:24:10
+   |
+24 | #[derive(HiddenRepr)] //~ ERROR expected item after attributes
+   |          ^^^^^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.rs b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.rs
new file mode 100644
index 0000000000..fb954baf15
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.rs
@@ -0,0 +1,15 @@
+// https://github.com/taiki-e/pin-project/issues/342
+
+#![allow(unaligned_references)]
+
+use auxiliary_macro::hidden_repr2;
+use pin_project::pin_project;
+
+#[pin_project] //~ ERROR reference to packed field is unaligned
+#[hidden_repr2]
+struct A {
+    #[pin]
+    f: u32,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.stderr b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.stderr
new file mode 100644
index 0000000000..8072ce2f5f
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/packed_sneaky-4.stderr
@@ -0,0 +1,16 @@
+error: reference to packed field is unaligned
+ --> tests/ui/pin_project/packed_sneaky-4.rs:8:1
+  |
+8 | #[pin_project] //~ ERROR reference to packed field is unaligned
+  | ^^^^^^^^^^^^^^
+  |
+note: the lint level is defined here
+ --> tests/ui/pin_project/packed_sneaky-4.rs:8:1
+  |
+8 | #[pin_project] //~ ERROR reference to packed field is unaligned
+  | ^^^^^^^^^^^^^^
+  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+  = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
+  = note: fields of packed structs are not properly aligned, and creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
+  = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
+  = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.rs b/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.rs
new file mode 100644
index 0000000000..15a82a9a92
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.rs
@@ -0,0 +1,23 @@
+// Even if allows private_in_public, these are errors.
+
+#![allow(private_in_public)]
+
+pub enum PublicEnum {
+    V(PrivateEnum), //~ ERROR E0446
+}
+
+enum PrivateEnum {
+    V(u8),
+}
+
+mod foo {
+    pub(crate) enum CrateEnum {
+        V(PrivateEnum), //~ ERROR E0446
+    }
+
+    enum PrivateEnum {
+        V(u8),
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.stderr b/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.stderr
new file mode 100644
index 0000000000..c93b265916
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/private_in_public-enum.stderr
@@ -0,0 +1,17 @@
+error[E0446]: private type `PrivateEnum` in public interface
+ --> tests/ui/pin_project/private_in_public-enum.rs:6:7
+  |
+6 |     V(PrivateEnum), //~ ERROR E0446
+  |       ^^^^^^^^^^^ can't leak private type
+...
+9 | enum PrivateEnum {
+  | ---------------- `PrivateEnum` declared as private
+
+error[E0446]: private type `foo::PrivateEnum` in public interface
+  --> tests/ui/pin_project/private_in_public-enum.rs:15:11
+   |
+15 |         V(PrivateEnum), //~ ERROR E0446
+   |           ^^^^^^^^^^^ can't leak private type
+...
+18 |     enum PrivateEnum {
+   |     ---------------- `foo::PrivateEnum` declared as private
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.rs b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.rs
new file mode 100644
index 0000000000..20dde12bd3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.rs
@@ -0,0 +1,11 @@
+use pin_project::pin_project;
+
+#[pin_project(project_replace)] //~ ERROR E0277
+struct Struct<T: ?Sized> {
+    f: T,
+}
+
+#[pin_project(project_replace)] //~ ERROR E0277
+struct TupleStruct<T: ?Sized>(T);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.stderr b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.stderr
new file mode 100644
index 0000000000..042b499434
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized.stderr
@@ -0,0 +1,118 @@
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+ --> tests/ui/pin_project/project_replace_unsized.rs:3:15
+  |
+3 | #[pin_project(project_replace)] //~ ERROR E0277
+  |               ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+4 | struct Struct<T: ?Sized> {
+  |               - this type parameter needs to be `std::marker::Sized`
+  |
+note: required because it appears within the type `Struct<T>`
+ --> tests/ui/pin_project/project_replace_unsized.rs:4:8
+  |
+4 | struct Struct<T: ?Sized> {
+  |        ^^^^^^
+  = help: unsized fn params are gated as an unstable feature
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+  |
+4 - struct Struct<T: ?Sized> {
+4 + struct Struct<T> {
+  |
+help: function arguments must have a statically known size, borrowed types always have a known size
+  |
+3 | #[pin_project(&project_replace)] //~ ERROR E0277
+  |               +
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+   --> tests/ui/pin_project/project_replace_unsized.rs:3:1
+    |
+3   | #[pin_project(project_replace)] //~ ERROR E0277
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+4   | struct Struct<T: ?Sized> {
+    |               - this type parameter needs to be `std::marker::Sized`
+    |
+note: required because it appears within the type `Struct<T>`
+   --> tests/ui/pin_project/project_replace_unsized.rs:4:8
+    |
+4   | struct Struct<T: ?Sized> {
+    |        ^^^^^^
+note: required by a bound in `UnsafeOverwriteGuard::<T>::new`
+   --> src/lib.rs
+    |
+    |     impl<T> UnsafeOverwriteGuard<T> {
+    |          ^ required by this bound in `UnsafeOverwriteGuard::<T>::new`
+    = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+    |
+4   - struct Struct<T: ?Sized> {
+4   + struct Struct<T> {
+    |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+    --> tests/ui/pin_project/project_replace_unsized.rs:5:5
+     |
+3    | #[pin_project(project_replace)] //~ ERROR E0277
+     | ------------------------------- required by a bound introduced by this call
+4    | struct Struct<T: ?Sized> {
+     |               - this type parameter needs to be `std::marker::Sized`
+5    |     f: T,
+     |     ^ doesn't have a size known at compile-time
+     |
+note: required by a bound in `std::ptr::read`
+    --> $RUST/core/src/ptr/mod.rs
+     |
+     | pub const unsafe fn read<T>(src: *const T) -> T {
+     |                          ^ required by this bound in `std::ptr::read`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+     |
+4    - struct Struct<T: ?Sized> {
+4    + struct Struct<T> {
+     |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+ --> tests/ui/pin_project/project_replace_unsized.rs:8:15
+  |
+8 | #[pin_project(project_replace)] //~ ERROR E0277
+  |               ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+9 | struct TupleStruct<T: ?Sized>(T);
+  |                    - this type parameter needs to be `std::marker::Sized`
+  |
+note: required because it appears within the type `TupleStruct<T>`
+ --> tests/ui/pin_project/project_replace_unsized.rs:9:8
+  |
+9 | struct TupleStruct<T: ?Sized>(T);
+  |        ^^^^^^^^^^^
+  = help: unsized fn params are gated as an unstable feature
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+  |
+9 - struct TupleStruct<T: ?Sized>(T);
+9 + struct TupleStruct<T>(T);
+  |
+help: function arguments must have a statically known size, borrowed types always have a known size
+  |
+8 | #[pin_project(&project_replace)] //~ ERROR E0277
+  |               +
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+   --> tests/ui/pin_project/project_replace_unsized.rs:8:1
+    |
+8   | #[pin_project(project_replace)] //~ ERROR E0277
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+9   | struct TupleStruct<T: ?Sized>(T);
+    |                    - this type parameter needs to be `std::marker::Sized`
+    |
+note: required because it appears within the type `TupleStruct<T>`
+   --> tests/ui/pin_project/project_replace_unsized.rs:9:8
+    |
+9   | struct TupleStruct<T: ?Sized>(T);
+    |        ^^^^^^^^^^^
+note: required by a bound in `UnsafeOverwriteGuard::<T>::new`
+   --> src/lib.rs
+    |
+    |     impl<T> UnsafeOverwriteGuard<T> {
+    |          ^ required by this bound in `UnsafeOverwriteGuard::<T>::new`
+    = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+    |
+9   - struct TupleStruct<T: ?Sized>(T);
+9   + struct TupleStruct<T>(T);
+    |
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.rs b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.rs
new file mode 100644
index 0000000000..e0fa25bf7d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.rs
@@ -0,0 +1,13 @@
+#![feature(unsized_fn_params)]
+
+use pin_project::pin_project;
+
+#[pin_project(project_replace)] //~ ERROR E0277
+struct Struct<T: ?Sized> {
+    f: T,
+}
+
+#[pin_project(project_replace)] //~ ERROR E0277
+struct TupleStruct<T: ?Sized>(T);
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.stderr b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.stderr
new file mode 100644
index 0000000000..10fad081aa
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/project_replace_unsized_fn_params.stderr
@@ -0,0 +1,112 @@
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+ --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:6:8
+  |
+6 | struct Struct<T: ?Sized> {
+  |        ^^^^^^^-^^^^^^^^^
+  |        |      |
+  |        |      this type parameter needs to be `std::marker::Sized`
+  |        doesn't have a size known at compile-time
+  |
+note: required because it appears within the type `__StructProjectionOwned<T>`
+ --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:6:8
+  |
+6 | struct Struct<T: ?Sized> {
+  |        ^^^^^^
+  = note: the return type of a function must have a statically known size
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+  |
+6 - struct Struct<T: ?Sized> {
+6 + struct Struct<T> {
+  |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+   --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:5:1
+    |
+5   | #[pin_project(project_replace)] //~ ERROR E0277
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+6   | struct Struct<T: ?Sized> {
+    |               - this type parameter needs to be `std::marker::Sized`
+    |
+note: required because it appears within the type `Struct<T>`
+   --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:6:8
+    |
+6   | struct Struct<T: ?Sized> {
+    |        ^^^^^^
+note: required by a bound in `UnsafeOverwriteGuard::<T>::new`
+   --> src/lib.rs
+    |
+    |     impl<T> UnsafeOverwriteGuard<T> {
+    |          ^ required by this bound in `UnsafeOverwriteGuard::<T>::new`
+    = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+    |
+6   - struct Struct<T: ?Sized> {
+6   + struct Struct<T> {
+    |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+    --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:7:5
+     |
+5    | #[pin_project(project_replace)] //~ ERROR E0277
+     | ------------------------------- required by a bound introduced by this call
+6    | struct Struct<T: ?Sized> {
+     |               - this type parameter needs to be `std::marker::Sized`
+7    |     f: T,
+     |     ^ doesn't have a size known at compile-time
+     |
+note: required by a bound in `std::ptr::read`
+    --> $RUST/core/src/ptr/mod.rs
+     |
+     | pub const unsafe fn read<T>(src: *const T) -> T {
+     |                          ^ required by this bound in `std::ptr::read`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+     |
+6    - struct Struct<T: ?Sized> {
+6    + struct Struct<T> {
+     |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:11:8
+   |
+11 | struct TupleStruct<T: ?Sized>(T);
+   |        ^^^^^^^^^^^^-^^^^^^^^^
+   |        |           |
+   |        |           this type parameter needs to be `std::marker::Sized`
+   |        doesn't have a size known at compile-time
+   |
+note: required because it appears within the type `__TupleStructProjectionOwned<T>`
+  --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:11:8
+   |
+11 | struct TupleStruct<T: ?Sized>(T);
+   |        ^^^^^^^^^^^
+   = note: the return type of a function must have a statically known size
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+11 - struct TupleStruct<T: ?Sized>(T);
+11 + struct TupleStruct<T>(T);
+   |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+   --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:10:1
+    |
+10  | #[pin_project(project_replace)] //~ ERROR E0277
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+11  | struct TupleStruct<T: ?Sized>(T);
+    |                    - this type parameter needs to be `std::marker::Sized`
+    |
+note: required because it appears within the type `TupleStruct<T>`
+   --> tests/ui/pin_project/project_replace_unsized_fn_params.rs:11:8
+    |
+11  | struct TupleStruct<T: ?Sized>(T);
+    |        ^^^^^^^^^^^
+note: required by a bound in `UnsafeOverwriteGuard::<T>::new`
+   --> src/lib.rs
+    |
+    |     impl<T> UnsafeOverwriteGuard<T> {
+    |          ^ required by this bound in `UnsafeOverwriteGuard::<T>::new`
+    = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+    |
+11  - struct TupleStruct<T: ?Sized>(T);
+11  + struct TupleStruct<T>(T);
+    |
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.rs b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.rs
new file mode 100644
index 0000000000..fd14da37c1
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.rs
@@ -0,0 +1,33 @@
+use std::{marker::PhantomPinned, pin::Pin};
+
+use auxiliary_macro::remove_attr;
+use pin_project::pin_project;
+
+fn is_unpin<T: Unpin>() {}
+
+#[pin_project]
+#[remove_attr(field_all)]
+struct A {
+    #[pin]
+    f: PhantomPinned,
+}
+
+#[remove_attr(field_all)]
+#[pin_project]
+struct B {
+    #[pin]
+    f: PhantomPinned,
+}
+
+fn main() {
+    is_unpin::<A>();
+    is_unpin::<B>();
+
+    let mut x = A { f: PhantomPinned };
+    let x = Pin::new(&mut x).project();
+    let _: Pin<&mut PhantomPinned> = x.f; //~ ERROR E0308
+
+    let mut x = B { f: PhantomPinned };
+    let x = Pin::new(&mut x).project();
+    let _: Pin<&mut PhantomPinned> = x.f; //~ ERROR E0308
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.stderr b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.stderr
new file mode 100644
index 0000000000..697cd63549
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-field.stderr
@@ -0,0 +1,21 @@
+error[E0308]: mismatched types
+  --> tests/ui/pin_project/remove-attr-from-field.rs:28:38
+   |
+28 |     let _: Pin<&mut PhantomPinned> = x.f; //~ ERROR E0308
+   |            -----------------------   ^^^ expected struct `Pin`, found `&mut PhantomPinned`
+   |            |
+   |            expected due to this
+   |
+   = note:         expected struct `Pin<&mut PhantomPinned>`
+           found mutable reference `&mut PhantomPinned`
+
+error[E0308]: mismatched types
+  --> tests/ui/pin_project/remove-attr-from-field.rs:32:38
+   |
+32 |     let _: Pin<&mut PhantomPinned> = x.f; //~ ERROR E0308
+   |            -----------------------   ^^^ expected struct `Pin`, found `&mut PhantomPinned`
+   |            |
+   |            expected due to this
+   |
+   = note:         expected struct `Pin<&mut PhantomPinned>`
+           found mutable reference `&mut PhantomPinned`
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.rs b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.rs
new file mode 100644
index 0000000000..cbe5aba234
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.rs
@@ -0,0 +1,47 @@
+use std::{marker::PhantomPinned, pin::Pin};
+
+use auxiliary_macro::remove_attr;
+use pin_project::pin_project;
+
+fn is_unpin<T: Unpin>() {}
+
+#[pin_project]
+#[remove_attr(struct_all)]
+struct A {
+    #[pin] //~ ERROR cannot find attribute `pin` in this scope
+    f: PhantomPinned,
+}
+
+#[remove_attr(struct_all)]
+#[pin_project]
+struct B {
+    #[pin] //~ ERROR cannot find attribute `pin` in this scope
+    f: PhantomPinned,
+}
+
+#[pin_project] //~ ERROR has been removed
+#[remove_attr(struct_pin)]
+struct C {
+    f: PhantomPinned,
+}
+
+#[remove_attr(struct_pin)]
+#[pin_project] // Ok
+struct D {
+    f: PhantomPinned,
+}
+
+fn main() {
+    is_unpin::<A>(); //~ ERROR E0277
+    is_unpin::<B>(); //~ ERROR E0277
+    is_unpin::<D>(); // Ok
+
+    let mut x = A { f: PhantomPinned };
+    let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+
+    let mut x = B { f: PhantomPinned };
+    let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+
+    let mut x = D { f: PhantomPinned };
+    let _ = Pin::new(&mut x).project(); //~ Ok
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.stderr b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.stderr
new file mode 100644
index 0000000000..1a9cd42ce2
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/remove-attr-from-struct.stderr
@@ -0,0 +1,107 @@
+error: #[pin_project] attribute has been removed
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:22:1
+   |
+22 | #[pin_project] //~ ERROR has been removed
+   | ^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot find attribute `pin` in this scope
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:18:7
+   |
+18 |     #[pin] //~ ERROR cannot find attribute `pin` in this scope
+   |       ^^^
+
+error: cannot find attribute `pin` in this scope
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:11:7
+   |
+11 |     #[pin] //~ ERROR cannot find attribute `pin` in this scope
+   |       ^^^
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:35:5
+   |
+35 |     is_unpin::<A>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^ within `A`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `A`
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:10:8
+   |
+10 | struct A {
+   |        ^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:6:16
+   |
+6  | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:36:5
+   |
+36 |     is_unpin::<B>(); //~ ERROR E0277
+   |     ^^^^^^^^^^^^^ within `B`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `B`
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:17:8
+   |
+17 | struct B {
+   |        ^
+note: required by a bound in `is_unpin`
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:6:16
+   |
+6  | fn is_unpin<T: Unpin>() {}
+   |                ^^^^^ required by this bound in `is_unpin`
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+   --> tests/ui/pin_project/remove-attr-from-struct.rs:40:22
+    |
+40  |     let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+    |             -------- ^^^^^^ within `A`, the trait `Unpin` is not implemented for `PhantomPinned`
+    |             |
+    |             required by a bound introduced by this call
+    |
+    = note: consider using `Box::pin`
+note: required because it appears within the type `A`
+   --> tests/ui/pin_project/remove-attr-from-struct.rs:10:8
+    |
+10  | struct A {
+    |        ^
+note: required by a bound in `Pin::<P>::new`
+   --> $RUST/core/src/pin.rs
+    |
+    | impl<P: Deref<Target: Unpin>> Pin<P> {
+    |                       ^^^^^ required by this bound in `Pin::<P>::new`
+
+error[E0599]: no method named `project` found for struct `Pin<&mut A>` in the current scope
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:40:30
+   |
+40 |     let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+   |                              ^^^^^^^ method not found in `Pin<&mut A>`
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+   --> tests/ui/pin_project/remove-attr-from-struct.rs:43:22
+    |
+43  |     let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+    |             -------- ^^^^^^ within `B`, the trait `Unpin` is not implemented for `PhantomPinned`
+    |             |
+    |             required by a bound introduced by this call
+    |
+    = note: consider using `Box::pin`
+note: required because it appears within the type `B`
+   --> tests/ui/pin_project/remove-attr-from-struct.rs:17:8
+    |
+17  | struct B {
+    |        ^
+note: required by a bound in `Pin::<P>::new`
+   --> $RUST/core/src/pin.rs
+    |
+    | impl<P: Deref<Target: Unpin>> Pin<P> {
+    |                       ^^^^^ required by this bound in `Pin::<P>::new`
+
+error[E0599]: no method named `project` found for struct `Pin<&mut B>` in the current scope
+  --> tests/ui/pin_project/remove-attr-from-struct.rs:43:30
+   |
+43 |     let _ = Pin::new(&mut x).project(); //~ ERROR E0277,E0599
+   |                              ^^^^^^^ method not found in `Pin<&mut B>`
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.rs b/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.rs
new file mode 100644
index 0000000000..de8181cb9d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.rs
@@ -0,0 +1,26 @@
+#![deny(renamed_and_removed_lints)]
+#![deny(safe_packed_borrows)] //~ ERROR has been renamed to `unaligned_references`
+#![allow(unaligned_references)]
+
+// This lint was removed in https://github.com/rust-lang/rust/pull/82525 (nightly-2021-03-28).
+// Refs:
+// - https://github.com/rust-lang/rust/pull/82525
+// - https://github.com/rust-lang/rust/issues/46043
+
+#[repr(packed)]
+struct Packed {
+    f: u32,
+}
+
+#[repr(packed(2))]
+struct PackedN {
+    f: u32,
+}
+
+fn main() {
+    let a = Packed { f: 1 };
+    let _ = &a.f;
+
+    let b = PackedN { f: 1 };
+    let _ = &b.f;
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.stderr b/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.stderr
new file mode 100644
index 0000000000..f483b6d3ce
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/safe_packed_borrows.stderr
@@ -0,0 +1,11 @@
+error: lint `safe_packed_borrows` has been renamed to `unaligned_references`
+ --> tests/ui/pin_project/safe_packed_borrows.rs:2:9
+  |
+2 | #![deny(safe_packed_borrows)] //~ ERROR has been renamed to `unaligned_references`
+  |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `unaligned_references`
+  |
+note: the lint level is defined here
+ --> tests/ui/pin_project/safe_packed_borrows.rs:1:9
+  |
+1 | #![deny(renamed_and_removed_lints)]
+  |         ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.rs b/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.rs
new file mode 100644
index 0000000000..eaf185d2a3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.rs
@@ -0,0 +1,21 @@
+#![forbid(unaligned_references)]
+
+// Refs: https://github.com/rust-lang/rust/issues/82523
+
+#[repr(packed)]
+struct Packed {
+    f: u32,
+}
+
+#[repr(packed(2))]
+struct PackedN {
+    f: u32,
+}
+
+fn main() {
+    let a = Packed { f: 1 };
+    let _ = &a.f; //~ ERROR reference to packed field is unaligned
+
+    let b = PackedN { f: 1 };
+    let _ = &b.f; //~ ERROR reference to packed field is unaligned
+}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.stderr b/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.stderr
new file mode 100644
index 0000000000..8d5ddfc591
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/unaligned_references.stderr
@@ -0,0 +1,26 @@
+error: reference to packed field is unaligned
+  --> tests/ui/pin_project/unaligned_references.rs:17:13
+   |
+17 |     let _ = &a.f; //~ ERROR reference to packed field is unaligned
+   |             ^^^^
+   |
+note: the lint level is defined here
+  --> tests/ui/pin_project/unaligned_references.rs:1:11
+   |
+1  | #![forbid(unaligned_references)]
+   |           ^^^^^^^^^^^^^^^^^^^^
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
+   = note: fields of packed structs are not properly aligned, and creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
+   = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
+
+error: reference to packed field is unaligned
+  --> tests/ui/pin_project/unaligned_references.rs:20:13
+   |
+20 |     let _ = &b.f; //~ ERROR reference to packed field is unaligned
+   |             ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
+   = note: fields of packed structs are not properly aligned, and creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
+   = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.rs b/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.rs
new file mode 100644
index 0000000000..3f5f32be69
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.rs
@@ -0,0 +1,11 @@
+use pin_project::pin_project;
+
+#[pin_project]
+struct S {
+    #[pin]
+    f: u8,
+}
+
+impl Unpin for __S {} //~ ERROR E0412,E0321
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.stderr b/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.stderr
new file mode 100644
index 0000000000..82c2aa5b91
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/unpin_sneaky.stderr
@@ -0,0 +1,5 @@
+error[E0412]: cannot find type `__S` in this scope
+ --> tests/ui/pin_project/unpin_sneaky.rs:9:16
+  |
+9 | impl Unpin for __S {} //~ ERROR E0412,E0321
+  |                ^^^ not found in this scope
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/visibility.rs b/third_party/rust/pin-project/tests/ui/pin_project/visibility.rs
new file mode 100644
index 0000000000..fdff5a6783
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/visibility.rs
@@ -0,0 +1,49 @@
+/// Only named projected types can be imported.
+/// See import_unnamed.rs for unnamed projected types.
+
+mod pub_ {
+    use pin_project::pin_project;
+
+    #[pin_project(project = DProj, project_ref = DProjRef)]
+    pub struct Default(());
+
+    #[pin_project(project = RProj, project_ref = RProjRef, project_replace = RProjOwn)]
+    pub struct Replace(());
+}
+pub mod pub_use {
+    #[rustfmt::skip]
+    pub use crate::pub_::DProj; //~ ERROR E0365
+    #[rustfmt::skip]
+    pub use crate::pub_::DProjRef; //~ ERROR E0365
+    #[rustfmt::skip]
+    pub use crate::pub_::RProj; //~ ERROR E0365
+    #[rustfmt::skip]
+    pub use crate::pub_::RProjOwn; //~ ERROR E0365
+    #[rustfmt::skip]
+    pub use crate::pub_::RProjRef; //~ ERROR E0365
+
+    // Confirm that the visibility of the original type is not changed.
+    pub use crate::pub_::{Default, Replace};
+}
+pub mod pub_use2 {
+    // Ok
+    #[allow(unused_imports)]
+    pub(crate) use crate::pub_::{DProj, DProjRef, RProj, RProjOwn, RProjRef};
+}
+
+mod pub_crate {
+    use pin_project::pin_project;
+
+    #[pin_project(project = DProj, project_ref = DProjRef)]
+    pub(crate) struct Default(());
+
+    #[pin_project(project = RProj, project_ref = RProjRef, project_replace = RProjOwn)]
+    pub(crate) struct Replace(());
+}
+pub mod pub_crate_use {
+    // Ok
+    #[allow(unused_imports)]
+    pub(crate) use crate::pub_crate::{DProj, DProjRef, RProj, RProjOwn, RProjRef};
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pin_project/visibility.stderr b/third_party/rust/pin-project/tests/ui/pin_project/visibility.stderr
new file mode 100644
index 0000000000..4d1b7229a6
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pin_project/visibility.stderr
@@ -0,0 +1,39 @@
+error[E0365]: `DProj` is only public within the crate, and cannot be re-exported outside
+  --> tests/ui/pin_project/visibility.rs:15:13
+   |
+15 |     pub use crate::pub_::DProj; //~ ERROR E0365
+   |             ^^^^^^^^^^^^^^^^^^ re-export of crate public `DProj`
+   |
+   = note: consider declaring type or module `DProj` with `pub`
+
+error[E0365]: `DProjRef` is only public within the crate, and cannot be re-exported outside
+  --> tests/ui/pin_project/visibility.rs:17:13
+   |
+17 |     pub use crate::pub_::DProjRef; //~ ERROR E0365
+   |             ^^^^^^^^^^^^^^^^^^^^^ re-export of crate public `DProjRef`
+   |
+   = note: consider declaring type or module `DProjRef` with `pub`
+
+error[E0365]: `RProj` is only public within the crate, and cannot be re-exported outside
+  --> tests/ui/pin_project/visibility.rs:19:13
+   |
+19 |     pub use crate::pub_::RProj; //~ ERROR E0365
+   |             ^^^^^^^^^^^^^^^^^^ re-export of crate public `RProj`
+   |
+   = note: consider declaring type or module `RProj` with `pub`
+
+error[E0365]: `RProjOwn` is only public within the crate, and cannot be re-exported outside
+  --> tests/ui/pin_project/visibility.rs:21:13
+   |
+21 |     pub use crate::pub_::RProjOwn; //~ ERROR E0365
+   |             ^^^^^^^^^^^^^^^^^^^^^ re-export of crate public `RProjOwn`
+   |
+   = note: consider declaring type or module `RProjOwn` with `pub`
+
+error[E0365]: `RProjRef` is only public within the crate, and cannot be re-exported outside
+  --> tests/ui/pin_project/visibility.rs:23:13
+   |
+23 |     pub use crate::pub_::RProjRef; //~ ERROR E0365
+   |             ^^^^^^^^^^^^^^^^^^^^^ re-export of crate public `RProjRef`
+   |
+   = note: consider declaring type or module `RProjRef` with `pub`
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.rs
new file mode 100644
index 0000000000..9f89942b21
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.rs
@@ -0,0 +1,17 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop)]
+struct Struct {
+    f: bool,
+}
+
+#[pinned_drop]
+impl PinnedDrop for Struct {
+    fn drop(mut self: Pin<&mut Self>) {
+        __drop_inner(__self);
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.stderr
new file mode 100644
index 0000000000..e3ceebd502
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/call-drop-inner.stderr
@@ -0,0 +1,16 @@
+error[E0061]: this function takes 0 arguments but 1 argument was supplied
+  --> tests/ui/pinned_drop/call-drop-inner.rs:13:9
+   |
+13 |         __drop_inner(__self);
+   |         ^^^^^^^^^^^^ ------ argument of type `Pin<&mut Struct>` unexpected
+   |
+note: function defined here
+  --> tests/ui/pinned_drop/call-drop-inner.rs:10:1
+   |
+10 | #[pinned_drop]
+   | ^^^^^^^^^^^^^^
+   = note: this error originates in the attribute macro `pinned_drop` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: remove the extra argument
+   |
+13 |         __drop_inner();
+   |         ~~~~~~~~~~~~~~
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.rs
new file mode 100644
index 0000000000..23d756d4dc
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.rs
@@ -0,0 +1,27 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+// In `Drop` impl, the implementor must specify the same requirement as type definition.
+
+struct DropImpl<T> {
+    f: T,
+}
+
+impl<T: Unpin> Drop for DropImpl<T> {
+    //~^ ERROR E0367
+    fn drop(&mut self) {}
+}
+
+#[pin_project(PinnedDrop)] //~ ERROR E0277
+struct PinnedDropImpl<T> {
+    #[pin]
+    f: T,
+}
+
+#[pinned_drop]
+impl<T: Unpin> PinnedDrop for PinnedDropImpl<T> {
+    fn drop(self: Pin<&mut Self>) {}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.stderr
new file mode 100644
index 0000000000..0587765709
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/conditional-drop-impl.stderr
@@ -0,0 +1,28 @@
+error[E0367]: `Drop` impl requires `T: Unpin` but the struct it is implemented for does not
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:11:9
+   |
+11 | impl<T: Unpin> Drop for DropImpl<T> {
+   |         ^^^^^
+   |
+note: the implementor must specify the same requirement
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:7:1
+   |
+7  | struct DropImpl<T> {
+   | ^^^^^^^^^^^^^^^^^^
+
+error[E0277]: `T` cannot be unpinned
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:16:15
+   |
+16 | #[pin_project(PinnedDrop)] //~ ERROR E0277
+   |               ^^^^^^^^^^ the trait `Unpin` is not implemented for `T`
+   |
+   = note: consider using `Box::pin`
+note: required because of the requirements on the impl of `PinnedDrop` for `PinnedDropImpl<T>`
+  --> tests/ui/pinned_drop/conditional-drop-impl.rs:23:16
+   |
+23 | impl<T: Unpin> PinnedDrop for PinnedDropImpl<T> {
+   |                ^^^^^^^^^^     ^^^^^^^^^^^^^^^^^
+help: consider restricting type parameter `T`
+   |
+17 | struct PinnedDropImpl<T: std::marker::Unpin> {
+   |                        ++++++++++++++++++++
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.rs
new file mode 100644
index 0000000000..e31f46f262
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.rs
@@ -0,0 +1,9 @@
+use pin_project::pin_project;
+
+#[pin_project(PinnedDrop)] //~ ERROR E0277
+struct Struct {
+    #[pin]
+    f: u8,
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.stderr
new file mode 100644
index 0000000000..ef8a7bf4b4
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/forget-pinned-drop-impl.stderr
@@ -0,0 +1,5 @@
+error[E0277]: the trait bound `Struct: PinnedDrop` is not satisfied
+ --> tests/ui/pinned_drop/forget-pinned-drop-impl.rs:3:15
+  |
+3 | #[pin_project(PinnedDrop)] //~ ERROR E0277
+  |               ^^^^^^^^^^ the trait `PinnedDrop` is not implemented for `Struct`
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.rs
new file mode 100644
index 0000000000..783167fc0d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.rs
@@ -0,0 +1,14 @@
+// by-ref binding `ref (mut) self` and sub-patterns `@` are not allowed in receivers (rejected by rustc).
+
+use std::pin::Pin;
+
+struct S {}
+
+impl S {
+    fn take_ref_self(ref self: Pin<&mut Self>) {} //~ ERROR expected identifier, found keyword `self`
+    fn take_ref_mut_self(ref mut self: Pin<&mut Self>) {} //~ ERROR expected identifier, found keyword `self`
+
+    fn self_subpat(self @ S {}: Self) {} //~ ERROR expected one of `)`, `,`, or `:`, found `@`
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.stderr
new file mode 100644
index 0000000000..464be5e5b5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid-self.stderr
@@ -0,0 +1,25 @@
+error: expected identifier, found keyword `self`
+ --> tests/ui/pinned_drop/invalid-self.rs:8:26
+  |
+8 |     fn take_ref_self(ref self: Pin<&mut Self>) {} //~ ERROR expected identifier, found keyword `self`
+  |                          ^^^^ expected identifier, found keyword
+
+error: expected identifier, found keyword `self`
+ --> tests/ui/pinned_drop/invalid-self.rs:9:34
+  |
+9 |     fn take_ref_mut_self(ref mut self: Pin<&mut Self>) {} //~ ERROR expected identifier, found keyword `self`
+  |                                  ^^^^ expected identifier, found keyword
+
+error: expected parameter name, found `@`
+  --> tests/ui/pinned_drop/invalid-self.rs:11:25
+   |
+11 |     fn self_subpat(self @ S {}: Self) {} //~ ERROR expected one of `)`, `,`, or `:`, found `@`
+   |                         ^ expected parameter name
+
+error: expected one of `)`, `,`, or `:`, found `@`
+  --> tests/ui/pinned_drop/invalid-self.rs:11:25
+   |
+11 |     fn self_subpat(self @ S {}: Self) {} //~ ERROR expected one of `)`, `,`, or `:`, found `@`
+   |                        -^ expected one of `)`, `,`, or `:`
+   |                        |
+   |                        help: missing `,`
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.rs
new file mode 100644
index 0000000000..fdadf8a516
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.rs
@@ -0,0 +1,231 @@
+mod argument {
+    use std::pin::Pin;
+
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct UnexpectedArg1(());
+
+    #[pinned_drop(foo)] //~ ERROR unexpected token
+    impl PinnedDrop for UnexpectedArg1 {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct UnexpectedArg2(());
+
+    #[pinned_drop()] // Ok
+    impl PinnedDrop for UnexpectedArg2 {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+}
+
+mod attribute {
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct Duplicate(());
+
+    #[pinned_drop]
+    #[pinned_drop] //~ ERROR duplicate #[pinned_drop] attribute
+    impl PinnedDrop for Duplicate {
+        fn drop(self: Pin<&mut Self>) {}
+    }
+}
+
+mod item {
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct TraitImpl(());
+
+    #[pinned_drop]
+    impl Drop for TraitImpl {} //~ ERROR may only be used on implementation for the `PinnedDrop` trait
+
+    #[pin_project(PinnedDrop)]
+    struct InherentImpl(());
+
+    #[pinned_drop]
+    impl InherentImpl {} //~ ERROR may only be used on implementation for the `PinnedDrop` trait
+
+    #[pinned_drop]
+    fn func(_: Pin<&mut ()>) {} //~ ERROR expected `impl`
+}
+
+mod unsafety {
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct Impl(());
+
+    #[pinned_drop]
+    unsafe impl PinnedDrop for Impl {
+        //~^ ERROR implementing the trait `PinnedDrop` is not unsafe
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Method(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Method {
+        unsafe fn drop(self: Pin<&mut Self>) {} //~ ERROR implementing the method `drop` is not unsafe
+    }
+}
+
+mod assoc_item {
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct Empty(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Empty {} //~ ERROR not all trait items implemented, missing: `drop`
+
+    #[pin_project(PinnedDrop)]
+    struct Const1(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Const1 {
+        const A: u8 = 0; //~ ERROR const `A` is not a member of trait `PinnedDrop`
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Const2(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Const2 {
+        fn drop(self: Pin<&mut Self>) {}
+        const A: u8 = 0; //~ ERROR const `A` is not a member of trait `PinnedDrop`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Type1(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Type1 {
+        type A = u8; //~ ERROR type `A` is not a member of trait `PinnedDrop`
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Type2(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Type2 {
+        fn drop(self: Pin<&mut Self>) {}
+        type A = u8; //~ ERROR type `A` is not a member of trait `PinnedDrop`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct Duplicate(());
+
+    #[pinned_drop]
+    impl PinnedDrop for Duplicate {
+        fn drop(self: Pin<&mut Self>) {}
+        fn drop(self: Pin<&mut Self>) {} //~ ERROR duplicate definitions with name `drop`
+    }
+}
+
+mod method {
+    use std::pin::Pin;
+
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    struct RetUnit(());
+
+    #[pinned_drop]
+    impl PinnedDrop for RetUnit {
+        fn drop(self: Pin<&mut Self>) -> () {} // Ok
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct RetTy(());
+
+    #[pinned_drop]
+    impl PinnedDrop for RetTy {
+        fn drop(self: Pin<&mut Self>) -> Self {} //~ ERROR method `drop` must return the unit type
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct NoArg(());
+
+    #[pinned_drop]
+    impl PinnedDrop for NoArg {
+        fn drop() {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct MultiArg(());
+
+    #[pinned_drop]
+    impl PinnedDrop for MultiArg {
+        fn drop(self: Pin<&mut Self>, _: ()) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct InvalidArg1(());
+
+    #[pinned_drop]
+    impl PinnedDrop for InvalidArg1 {
+        fn drop(&mut self) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct InvalidArg2(());
+
+    #[pinned_drop]
+    impl PinnedDrop for InvalidArg2 {
+        fn drop(_: Pin<&mut Self>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct InvalidArg3(());
+
+    #[pinned_drop]
+    impl PinnedDrop for InvalidArg3 {
+        fn drop(self: Pin<&Self>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct InvalidArg4(());
+
+    #[pinned_drop]
+    impl PinnedDrop for InvalidArg4 {
+        fn drop(self: Pin<&mut ()>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    }
+
+    #[pin_project(PinnedDrop)]
+    struct InvalidName(());
+
+    #[pinned_drop]
+    impl PinnedDrop for InvalidName {
+        fn pinned_drop(self: Pin<&mut Self>) {} //~ ERROR method `pinned_drop` is not a member of trait `PinnedDrop
+    }
+}
+
+mod self_ty {
+    use pin_project::pinned_drop;
+
+    #[pinned_drop]
+    impl PinnedDrop for () {
+        //~^ ERROR implementing the trait `PinnedDrop` on this type is unsupported
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for &mut A {
+        //~^ ERROR implementing the trait `PinnedDrop` on this type is unsupported
+        fn drop(self: Pin<&mut Self>) {}
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for [A] {
+        //~^ ERROR implementing the trait `PinnedDrop` on this type is unsupported
+        fn drop(self: Pin<&mut Self>) {}
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.stderr
new file mode 100644
index 0000000000..d509964b24
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/invalid.stderr
@@ -0,0 +1,143 @@
+error: unexpected token: `foo`
+ --> tests/ui/pinned_drop/invalid.rs:9:19
+  |
+9 |     #[pinned_drop(foo)] //~ ERROR unexpected token
+  |                   ^^^
+
+error: duplicate #[pinned_drop] attribute
+  --> tests/ui/pinned_drop/invalid.rs:30:5
+   |
+30 |     #[pinned_drop] //~ ERROR duplicate #[pinned_drop] attribute
+   |     ^^^^^^^^^^^^^^
+
+error: #[pinned_drop] may only be used on implementation for the `PinnedDrop` trait
+  --> tests/ui/pinned_drop/invalid.rs:43:10
+   |
+43 |     impl Drop for TraitImpl {} //~ ERROR may only be used on implementation for the `PinnedDrop` trait
+   |          ^^^^
+
+error: #[pinned_drop] may only be used on implementation for the `PinnedDrop` trait
+  --> tests/ui/pinned_drop/invalid.rs:49:10
+   |
+49 |     impl InherentImpl {} //~ ERROR may only be used on implementation for the `PinnedDrop` trait
+   |          ^^^^^^^^^^^^
+
+error: expected `impl`
+  --> tests/ui/pinned_drop/invalid.rs:52:5
+   |
+52 |     fn func(_: Pin<&mut ()>) {} //~ ERROR expected `impl`
+   |     ^^
+
+error: implementing the trait `PinnedDrop` is not unsafe
+  --> tests/ui/pinned_drop/invalid.rs:62:5
+   |
+62 |     unsafe impl PinnedDrop for Impl {
+   |     ^^^^^^
+
+error: implementing the method `drop` is not unsafe
+  --> tests/ui/pinned_drop/invalid.rs:72:9
+   |
+72 |         unsafe fn drop(self: Pin<&mut Self>) {} //~ ERROR implementing the method `drop` is not unsafe
+   |         ^^^^^^
+
+error: not all trait items implemented, missing: `drop`
+  --> tests/ui/pinned_drop/invalid.rs:83:5
+   |
+83 |     impl PinnedDrop for Empty {} //~ ERROR not all trait items implemented, missing: `drop`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: const `A` is not a member of trait `PinnedDrop`
+  --> tests/ui/pinned_drop/invalid.rs:90:9
+   |
+90 |         const A: u8 = 0; //~ ERROR const `A` is not a member of trait `PinnedDrop`
+   |         ^^^^^^^^^^^^^^^^
+
+error: const `A` is not a member of trait `PinnedDrop`
+   --> tests/ui/pinned_drop/invalid.rs:100:9
+    |
+100 |         const A: u8 = 0; //~ ERROR const `A` is not a member of trait `PinnedDrop`
+    |         ^^^^^^^^^^^^^^^^
+
+error: type `A` is not a member of trait `PinnedDrop`
+   --> tests/ui/pinned_drop/invalid.rs:108:9
+    |
+108 |         type A = u8; //~ ERROR type `A` is not a member of trait `PinnedDrop`
+    |         ^^^^^^^^^^^^
+
+error: type `A` is not a member of trait `PinnedDrop`
+   --> tests/ui/pinned_drop/invalid.rs:118:9
+    |
+118 |         type A = u8; //~ ERROR type `A` is not a member of trait `PinnedDrop`
+    |         ^^^^^^^^^^^^
+
+error: duplicate definitions with name `drop`
+   --> tests/ui/pinned_drop/invalid.rs:127:9
+    |
+127 |         fn drop(self: Pin<&mut Self>) {} //~ ERROR duplicate definitions with name `drop`
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: method `drop` must return the unit type
+   --> tests/ui/pinned_drop/invalid.rs:149:42
+    |
+149 |         fn drop(self: Pin<&mut Self>) -> Self {} //~ ERROR method `drop` must return the unit type
+    |                                          ^^^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:157:16
+    |
+157 |         fn drop() {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                ^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:165:17
+    |
+165 |         fn drop(self: Pin<&mut Self>, _: ()) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:173:17
+    |
+173 |         fn drop(&mut self) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                 ^^^^^^^^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:181:17
+    |
+181 |         fn drop(_: Pin<&mut Self>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                 ^^^^^^^^^^^^^^^^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:189:17
+    |
+189 |         fn drop(self: Pin<&Self>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                 ^^^^^^^^^^^^^^^^
+
+error: method `drop` must take an argument `self: Pin<&mut Self>`
+   --> tests/ui/pinned_drop/invalid.rs:197:17
+    |
+197 |         fn drop(self: Pin<&mut ()>) {} //~ ERROR method `drop` must take an argument `self: Pin<&mut Self>`
+    |                 ^^^^^^^^^^^^^^^^^^
+
+error: method `pinned_drop` is not a member of trait `PinnedDrop
+   --> tests/ui/pinned_drop/invalid.rs:205:12
+    |
+205 |         fn pinned_drop(self: Pin<&mut Self>) {} //~ ERROR method `pinned_drop` is not a member of trait `PinnedDrop
+    |            ^^^^^^^^^^^
+
+error: implementing the trait `PinnedDrop` on this type is unsupported
+   --> tests/ui/pinned_drop/invalid.rs:213:25
+    |
+213 |     impl PinnedDrop for () {
+    |                         ^^
+
+error: implementing the trait `PinnedDrop` on this type is unsupported
+   --> tests/ui/pinned_drop/invalid.rs:219:25
+    |
+219 |     impl PinnedDrop for &mut A {
+    |                         ^^^^^^
+
+error: implementing the trait `PinnedDrop` on this type is unsupported
+   --> tests/ui/pinned_drop/invalid.rs:225:25
+    |
+225 |     impl PinnedDrop for [A] {
+    |                         ^^^
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.rs
new file mode 100644
index 0000000000..391f2901ed
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.rs
@@ -0,0 +1,17 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project]
+struct S {
+    #[pin]
+    f: u8,
+}
+
+#[pinned_drop]
+impl PinnedDrop for S {
+    //~^ ERROR E0119
+    fn drop(self: Pin<&mut Self>) {}
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.stderr
new file mode 100644
index 0000000000..254225454a
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/pinned-drop-no-attr-arg.stderr
@@ -0,0 +1,8 @@
+error[E0119]: conflicting implementations of trait `_::_pin_project::__private::PinnedDrop` for type `S`
+  --> tests/ui/pinned_drop/pinned-drop-no-attr-arg.rs:12:1
+   |
+5  | #[pin_project]
+   | -------------- first implementation here
+...
+12 | impl PinnedDrop for S {
+   | ^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `S`
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/self.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/self.rs
new file mode 100644
index 0000000000..ff634022e5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/self.rs
@@ -0,0 +1,58 @@
+pub mod self_in_macro_def {
+    use std::pin::Pin;
+
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    pub struct S {
+        f: (),
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for S {
+        fn drop(self: Pin<&mut Self>) {
+            macro_rules! t {
+                () => {{
+                    let _ = self; //~ ERROR E0434
+
+                    fn f(self: ()) {} //~ ERROR `self` parameter is only allowed in associated functions
+                }};
+            }
+            t!();
+        }
+    }
+}
+
+pub mod self_span {
+    use std::pin::Pin;
+
+    use pin_project::{pin_project, pinned_drop};
+
+    #[pin_project(PinnedDrop)]
+    pub struct S {
+        f: (),
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for S {
+        fn drop(self: Pin<&mut Self>) {
+            let _: () = self; //~ ERROR E0308
+            let _: Self = Self; //~ ERROR E0423
+        }
+    }
+
+    #[pin_project(PinnedDrop)]
+    pub enum E {
+        V { f: () },
+    }
+
+    #[pinned_drop]
+    impl PinnedDrop for E {
+        fn drop(self: Pin<&mut Self>) {
+            let _: () = self; //~ ERROR E0308
+            let _: Self = Self::V; //~ ERROR E0533
+        }
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/self.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/self.stderr
new file mode 100644
index 0000000000..a19d5a0db3
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/self.stderr
@@ -0,0 +1,62 @@
+error: `self` parameter is only allowed in associated functions
+  --> tests/ui/pinned_drop/self.rs:18:26
+   |
+18 |                     fn f(self: ()) {} //~ ERROR `self` parameter is only allowed in associated functions
+   |                          ^^^^ not semantically valid as function parameter
+...
+21 |             t!();
+   |             ---- in this macro invocation
+   |
+   = note: associated functions are those in `impl` or `trait` definitions
+   = note: this error originates in the macro `t` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0434]: can't capture dynamic environment in a fn item
+  --> tests/ui/pinned_drop/self.rs:16:29
+   |
+16 |                     let _ = self; //~ ERROR E0434
+   |                             ^^^^
+...
+21 |             t!();
+   |             ---- in this macro invocation
+   |
+   = help: use the `|| { ... }` closure form instead
+   = note: this error originates in the macro `t` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0423]: expected value, found struct `S`
+  --> tests/ui/pinned_drop/self.rs:40:27
+   |
+32 | /     pub struct S {
+33 | |         f: (),
+34 | |     }
+   | |_____- `S` defined here
+...
+40 |               let _: Self = Self; //~ ERROR E0423
+   |                             ^^^^ help: use struct literal syntax instead: `S { f: val }`
+
+error[E0308]: mismatched types
+  --> tests/ui/pinned_drop/self.rs:39:25
+   |
+39 |             let _: () = self; //~ ERROR E0308
+   |                    --   ^^^^ expected `()`, found struct `Pin`
+   |                    |
+   |                    expected due to this
+   |
+   = note: expected unit type `()`
+                 found struct `Pin<&mut self_span::S>`
+
+error[E0308]: mismatched types
+  --> tests/ui/pinned_drop/self.rs:52:25
+   |
+52 |             let _: () = self; //~ ERROR E0308
+   |                    --   ^^^^ expected `()`, found struct `Pin`
+   |                    |
+   |                    expected due to this
+   |
+   = note: expected unit type `()`
+                 found struct `Pin<&mut E>`
+
+error[E0533]: expected unit struct, unit variant or constant, found struct variant `E::V`
+  --> tests/ui/pinned_drop/self.rs:53:27
+   |
+53 |             let _: Self = Self::V; //~ ERROR E0533
+   |                           ^^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.rs b/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.rs
new file mode 100644
index 0000000000..3ee2b56c37
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.rs
@@ -0,0 +1,18 @@
+use std::pin::Pin;
+
+use pin_project::{pin_project, pinned_drop};
+
+#[pin_project(PinnedDrop)]
+struct S {
+    #[pin]
+    f: u8,
+}
+
+#[pinned_drop]
+impl PinnedDrop for S {
+    fn drop(self: Pin<&mut Self>) {
+        self.project().f.get_unchecked_mut(); //~ ERROR call to unsafe function is unsafe and requires unsafe function or block [E0133]
+    }
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.stderr b/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.stderr
new file mode 100644
index 0000000000..9f7dd440a5
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/pinned_drop/unsafe-call.stderr
@@ -0,0 +1,7 @@
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> tests/ui/pinned_drop/unsafe-call.rs:14:9
+   |
+14 |         self.project().f.get_unchecked_mut(); //~ ERROR call to unsafe function is unsafe and requires unsafe function or block [E0133]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
diff --git a/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.rs b/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.rs
new file mode 100644
index 0000000000..ac9d1f8682
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.rs
@@ -0,0 +1,30 @@
+use pin_project::pin_project;
+
+#[pin_project(UnsafeUnpin)] //~ ERROR E0119
+struct Foo<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T, U> Unpin for Foo<T, U> where T: Unpin {}
+
+#[pin_project(UnsafeUnpin)] //~ ERROR E0119
+struct Bar<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T, U> Unpin for Bar<T, U> {}
+
+#[pin_project(UnsafeUnpin)] //~ ERROR E0119
+struct Baz<T, U> {
+    #[pin]
+    f1: T,
+    f2: U,
+}
+
+impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.stderr b/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.stderr
new file mode 100644
index 0000000000..0e89b03a28
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unsafe_unpin/conflict-unpin.stderr
@@ -0,0 +1,32 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Foo<_, _>`
+  --> tests/ui/unsafe_unpin/conflict-unpin.rs:3:15
+   |
+3  | #[pin_project(UnsafeUnpin)] //~ ERROR E0119
+   |               ^^^^^^^^^^^ conflicting implementation for `Foo<_, _>`
+...
+10 | impl<T, U> Unpin for Foo<T, U> where T: Unpin {}
+   | ------------------------------ first implementation here
+   |
+   = note: upstream crates may add a new impl of trait `_::_pin_project::UnsafeUnpin` for type `_::_pin_project::__private::Wrapper<'_, Foo<_, _>>` in future versions
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Bar<_, _>`
+  --> tests/ui/unsafe_unpin/conflict-unpin.rs:12:15
+   |
+12 | #[pin_project(UnsafeUnpin)] //~ ERROR E0119
+   |               ^^^^^^^^^^^ conflicting implementation for `Bar<_, _>`
+...
+19 | impl<T, U> Unpin for Bar<T, U> {}
+   | ------------------------------ first implementation here
+   |
+   = note: upstream crates may add a new impl of trait `_::_pin_project::UnsafeUnpin` for type `_::_pin_project::__private::Wrapper<'_, Bar<_, _>>` in future versions
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Baz<_, _>`
+  --> tests/ui/unsafe_unpin/conflict-unpin.rs:21:15
+   |
+21 | #[pin_project(UnsafeUnpin)] //~ ERROR E0119
+   |               ^^^^^^^^^^^ conflicting implementation for `Baz<_, _>`
+...
+28 | impl<T: Unpin, U: Unpin> Unpin for Baz<T, U> {}
+   | -------------------------------------------- first implementation here
+   |
+   = note: upstream crates may add a new impl of trait `_::_pin_project::UnsafeUnpin` for type `_::_pin_project::__private::Wrapper<'_, Baz<_, _>>` in future versions
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/README.md b/third_party/rust/pin-project/tests/ui/unstable-features/README.md
new file mode 100644
index 0000000000..96f370ca77
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/README.md
@@ -0,0 +1,7 @@
+# UI tests for unstable features
+
+These tests check how the guarantees and features provided by pin-project
+interact with unstable language features.
+
+The names of the files contained in this directory need to begin with the name
+of the feature.
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.rs b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.rs
new file mode 100644
index 0000000000..542250bd90
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.rs
@@ -0,0 +1,20 @@
+// Note: If you change this test, change 'marker_trait_attr.rs' at the same time.
+
+use std::marker::PhantomPinned;
+
+use pin_project::pin_project;
+
+#[pin_project] //~ ERROR E0119
+struct Struct<T> {
+    #[pin]
+    f: T,
+}
+
+// unsound Unpin impl
+impl<T> Unpin for Struct<T> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Struct<PhantomPinned>>()
+}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.stderr
new file mode 100644
index 0000000000..3412f2e224
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr-feature-gate.stderr
@@ -0,0 +1,10 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Struct<_>`
+  --> tests/ui/unstable-features/marker_trait_attr-feature-gate.rs:7:1
+   |
+7  | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Struct<_>`
+...
+14 | impl<T> Unpin for Struct<T> {}
+   | --------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.rs b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.rs
new file mode 100644
index 0000000000..9c8e6643e0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.rs
@@ -0,0 +1,26 @@
+// Note: If you change this test, change 'marker_trait_attr-feature-gate.rs' at the same time.
+
+// marker_trait_attr
+// Tracking issue: https://github.com/rust-lang/rust/issues/29864
+#![feature(marker_trait_attr)]
+
+// See https://github.com/taiki-e/pin-project/issues/105#issuecomment-535355974
+
+use std::marker::PhantomPinned;
+
+use pin_project::pin_project;
+
+#[pin_project] //~ ERROR E0119
+struct Struct<T> {
+    #[pin]
+    f: T,
+}
+
+// unsound Unpin impl
+impl<T> Unpin for Struct<T> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Struct<PhantomPinned>>()
+}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.stderr
new file mode 100644
index 0000000000..2b68c80ffb
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/marker_trait_attr.stderr
@@ -0,0 +1,10 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Struct<_>`
+  --> tests/ui/unstable-features/marker_trait_attr.rs:13:1
+   |
+13 | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Struct<_>`
+...
+20 | impl<T> Unpin for Struct<T> {}
+   | --------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.rs b/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.rs
new file mode 100644
index 0000000000..96056423a0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.rs
@@ -0,0 +1,23 @@
+#![feature(negative_impls)]
+#![deny(suspicious_auto_trait_impls)]
+
+// https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/design.20meeting.3A.20backlog.20bonanza/near/269471299
+// https://github.com/taiki-e/pin-project/issues/340
+
+#[pin_project::pin_project]
+struct Foo<Pinned, Unpinned> {
+    #[pin]
+    pinned: Pinned,
+
+    unpinned: Unpinned,
+}
+
+struct MyPhantomPinned {}
+impl !Unpin for MyPhantomPinned {}
+impl Unpin for Foo<MyPhantomPinned, ()> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Foo<MyPhantomPinned, ()>>()
+}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.stderr
new file mode 100644
index 0000000000..0d99e2bf69
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/negative_impls.stderr
@@ -0,0 +1,19 @@
+error: cross-crate traits with a default impl, like `Unpin`, should not be specialized
+  --> tests/ui/unstable-features/negative_impls.rs:17:1
+   |
+17 | impl Unpin for Foo<MyPhantomPinned, ()> {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> tests/ui/unstable-features/negative_impls.rs:2:9
+   |
+2  | #![deny(suspicious_auto_trait_impls)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #93367 <https://github.com/rust-lang/rust/issues/93367>
+   = note: `MyPhantomPinned` is not a generic parameter
+note: try using the same sequence of generic parameters as the struct definition
+  --> tests/ui/unstable-features/negative_impls.rs:8:1
+   |
+8  | struct Foo<Pinned, Unpinned> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.rs b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.rs
new file mode 100644
index 0000000000..012c8709bd
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.rs
@@ -0,0 +1,20 @@
+// Note: If you change this test, change 'overlapping_marker_traits.rs' at the same time.
+
+use std::marker::PhantomPinned;
+
+use pin_project::pin_project;
+
+#[pin_project] //~ ERROR E0119
+struct Struct<T> {
+    #[pin]
+    f: T,
+}
+
+// unsound Unpin impl
+impl<T> Unpin for Struct<T> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Struct<PhantomPinned>>()
+}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.stderr
new file mode 100644
index 0000000000..918d804d0e
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits-feature-gate.stderr
@@ -0,0 +1,10 @@
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Struct<_>`
+  --> tests/ui/unstable-features/overlapping_marker_traits-feature-gate.rs:7:1
+   |
+7  | #[pin_project] //~ ERROR E0119
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Struct<_>`
+...
+14 | impl<T> Unpin for Struct<T> {}
+   | --------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.rs b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.rs
new file mode 100644
index 0000000000..8dc27c1dba
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.rs
@@ -0,0 +1,30 @@
+// Note: If you change this test, change 'overlapping_marker_traits-feature-gate.rs' at the same time.
+
+// This feature could break the guarantee for Unpin provided by pin-project,
+// but was removed in https://github.com/rust-lang/rust/pull/68544 (nightly-2020-02-06).
+// Refs:
+// - https://github.com/rust-lang/rust/issues/29864#issuecomment-515780867
+// - https://github.com/taiki-e/pin-project/issues/105
+
+// overlapping_marker_traits
+// Tracking issue: https://github.com/rust-lang/rust/issues/29864
+#![feature(overlapping_marker_traits)]
+
+use std::marker::PhantomPinned;
+
+use pin_project::pin_project;
+
+#[pin_project]
+struct Struct<T> {
+    #[pin]
+    f: T,
+}
+
+// unsound Unpin impl
+impl<T> Unpin for Struct<T> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Struct<PhantomPinned>>()
+}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.stderr
new file mode 100644
index 0000000000..3e8411d4b0
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/overlapping_marker_traits.stderr
@@ -0,0 +1,18 @@
+error[E0557]: feature has been removed
+  --> tests/ui/unstable-features/overlapping_marker_traits.rs:11:12
+   |
+11 | #![feature(overlapping_marker_traits)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^ feature has been removed
+   |
+   = note: removed in favor of `#![feature(marker_trait_attr)]`
+
+error[E0119]: conflicting implementations of trait `std::marker::Unpin` for type `Struct<_>`
+  --> tests/ui/unstable-features/overlapping_marker_traits.rs:17:1
+   |
+17 | #[pin_project]
+   | ^^^^^^^^^^^^^^ conflicting implementation for `Struct<_>`
+...
+24 | impl<T> Unpin for Struct<T> {}
+   | --------------------------- first implementation here
+   |
+   = note: this error originates in the derive macro `::pin_project::__private::__PinProjectInternalDerive` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.rs b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.rs
new file mode 100644
index 0000000000..f8467b082e
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.rs
@@ -0,0 +1,53 @@
+// Note: If you change this test, change 'trivial_bounds.rs' at the same time.
+
+mod phantom_pinned {
+    use std::marker::{PhantomData, PhantomPinned};
+
+    struct A(PhantomPinned);
+
+    impl Unpin for A where PhantomPinned: Unpin {} //~ ERROR E0277
+
+    struct Wrapper<T>(T);
+
+    impl<T> Unpin for Wrapper<T> where T: Unpin {}
+
+    struct B(PhantomPinned);
+
+    impl Unpin for B where Wrapper<PhantomPinned>: Unpin {} //~ ERROR E0277
+
+    struct WrapperWithLifetime<'a, T>(PhantomData<&'a ()>, T);
+
+    impl<T> Unpin for WrapperWithLifetime<'_, T> where T: Unpin {}
+
+    struct C(PhantomPinned);
+
+    impl<'a> Unpin for C where WrapperWithLifetime<'a, PhantomPinned>: Unpin {} // Ok
+}
+
+mod inner {
+    use std::marker::{PhantomData, PhantomPinned};
+
+    struct Inner(PhantomPinned);
+
+    struct A(Inner);
+
+    impl Unpin for A where Inner: Unpin {} //~ ERROR E0277
+
+    struct Wrapper<T>(T);
+
+    impl<T> Unpin for Wrapper<T> where T: Unpin {}
+
+    struct B(Inner);
+
+    impl Unpin for B where Wrapper<Inner>: Unpin {} //~ ERROR E0277
+
+    struct WrapperWithLifetime<'a, T>(PhantomData<&'a ()>, T);
+
+    impl<T> Unpin for WrapperWithLifetime<'_, T> where T: Unpin {}
+
+    struct C(Inner);
+
+    impl<'a> Unpin for C where WrapperWithLifetime<'a, Inner>: Unpin {} // Ok
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.stderr
new file mode 100644
index 0000000000..2e316585ed
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds-feature-gate.stderr
@@ -0,0 +1,59 @@
+error[E0277]: `PhantomPinned` cannot be unpinned
+ --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:8:28
+  |
+8 |     impl Unpin for A where PhantomPinned: Unpin {} //~ ERROR E0277
+  |                            ^^^^^^^^^^^^^^^^^^^^ the trait `Unpin` is not implemented for `PhantomPinned`
+  |
+  = note: consider using `Box::pin`
+  = help: see issue #48214
+  = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:16:28
+   |
+16 |     impl Unpin for B where Wrapper<PhantomPinned>: Unpin {} //~ ERROR E0277
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because of the requirements on the impl of `Unpin` for `phantom_pinned::Wrapper<PhantomPinned>`
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:12:13
+   |
+12 |     impl<T> Unpin for Wrapper<T> where T: Unpin {}
+   |             ^^^^^     ^^^^^^^^^^
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:34:28
+   |
+34 |     impl Unpin for A where Inner: Unpin {} //~ ERROR E0277
+   |                            ^^^^^^^^^^^^ within `Inner`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `Inner`
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:30:12
+   |
+30 |     struct Inner(PhantomPinned);
+   |            ^^^^^
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+
+error[E0277]: `PhantomPinned` cannot be unpinned
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:42:28
+   |
+42 |     impl Unpin for B where Wrapper<Inner>: Unpin {} //~ ERROR E0277
+   |                            ^^^^^^^^^^^^^^^^^^^^^ within `Inner`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |
+   = note: consider using `Box::pin`
+note: required because it appears within the type `Inner`
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:30:12
+   |
+30 |     struct Inner(PhantomPinned);
+   |            ^^^^^
+note: required because of the requirements on the impl of `Unpin` for `inner::Wrapper<Inner>`
+  --> tests/ui/unstable-features/trivial_bounds-feature-gate.rs:38:13
+   |
+38 |     impl<T> Unpin for Wrapper<T> where T: Unpin {}
+   |             ^^^^^     ^^^^^^^^^^
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.rs b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.rs
new file mode 100644
index 0000000000..41f885d4e7
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.rs
@@ -0,0 +1,38 @@
+// Note: If you change this test, change 'trivial_bounds-feature-gate.rs' at the same time.
+
+// trivial_bounds
+// Tracking issue: https://github.com/rust-lang/rust/issues/48214
+#![feature(trivial_bounds)]
+#![deny(trivial_bounds)]
+
+use std::marker::{PhantomData, PhantomPinned};
+
+fn inner() {
+    struct Inner(PhantomPinned);
+
+    struct A(PhantomPinned);
+
+    impl Unpin for A where PhantomPinned: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+
+    struct B(Inner);
+
+    impl Unpin for B where Inner: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+
+    struct Wrapper<T>(T);
+
+    impl<T> Unpin for Wrapper<T> where T: Unpin {}
+
+    struct C(Inner);
+
+    impl Unpin for C where Wrapper<Inner>: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+
+    struct WrapperWithLifetime<'a, T>(PhantomData<&'a ()>, T);
+
+    impl<T> Unpin for WrapperWithLifetime<'_, T> where T: Unpin {}
+
+    struct D(Inner);
+
+    impl<'a> Unpin for D where WrapperWithLifetime<'a, Inner>: Unpin {} // Ok
+}
+
+fn main() {}
diff --git a/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.stderr b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.stderr
new file mode 100644
index 0000000000..23f45c738d
--- /dev/null
+++ b/third_party/rust/pin-project/tests/ui/unstable-features/trivial_bounds.stderr
@@ -0,0 +1,23 @@
+error: trait bound PhantomPinned: Unpin does not depend on any type or lifetime parameters
+  --> tests/ui/unstable-features/trivial_bounds.rs:15:43
+   |
+15 |     impl Unpin for A where PhantomPinned: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+   |                                           ^^^^^
+   |
+note: the lint level is defined here
+  --> tests/ui/unstable-features/trivial_bounds.rs:6:9
+   |
+6  | #![deny(trivial_bounds)]
+   |         ^^^^^^^^^^^^^^
+
+error: trait bound Inner: Unpin does not depend on any type or lifetime parameters
+  --> tests/ui/unstable-features/trivial_bounds.rs:19:35
+   |
+19 |     impl Unpin for B where Inner: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+   |                                   ^^^^^
+
+error: trait bound Wrapper<Inner>: Unpin does not depend on any type or lifetime parameters
+  --> tests/ui/unstable-features/trivial_bounds.rs:27:44
+   |
+27 |     impl Unpin for C where Wrapper<Inner>: Unpin {} //~ ERROR Unpin does not depend on any type or lifetime parameters
+   |                                            ^^^^^
diff --git a/third_party/rust/pin-project/tests/unsafe_unpin.rs b/third_party/rust/pin-project/tests/unsafe_unpin.rs
new file mode 100644
index 0000000000..8b6411c775
--- /dev/null
+++ b/third_party/rust/pin-project/tests/unsafe_unpin.rs
@@ -0,0 +1,50 @@
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+#![allow(dead_code)]
+
+#[macro_use]
+mod auxiliary;
+
+use std::marker::PhantomPinned;
+
+use pin_project::{pin_project, UnsafeUnpin};
+
+#[pin_project(UnsafeUnpin)]
+pub struct Blah<T, U> {
+    f1: U,
+    #[pin]
+    f2: T,
+}
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Blah<T, U> {}
+
+assert_unpin!(Blah<(), ()>);
+assert_unpin!(Blah<(), PhantomPinned>);
+assert_not_unpin!(Blah<PhantomPinned, ()>);
+assert_not_unpin!(Blah<PhantomPinned, PhantomPinned>);
+
+#[pin_project(UnsafeUnpin)]
+struct OverlappingLifetimeNames<'pin, T, U> {
+    #[pin]
+    f1: U,
+    #[pin]
+    f2: Option<T>,
+    f3: &'pin (),
+}
+
+unsafe impl<T: Unpin, U: Unpin> UnsafeUnpin for OverlappingLifetimeNames<'_, T, U> {}
+
+assert_unpin!(OverlappingLifetimeNames<'_, (), ()>);
+assert_not_unpin!(OverlappingLifetimeNames<'_, PhantomPinned, ()>);
+assert_not_unpin!(OverlappingLifetimeNames<'_, (), PhantomPinned>);
+assert_not_unpin!(OverlappingLifetimeNames<'_, PhantomPinned, PhantomPinned>);
+
+#[test]
+fn trivial_bounds() {
+    #[pin_project(UnsafeUnpin)]
+    pub struct NotImplementUnsafUnpin {
+        #[pin]
+        f: PhantomPinned,
+    }
+
+    assert_not_unpin!(NotImplementUnsafUnpin);
+}