Merging upstream version 127.0.

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

61 files changed, 5783 insertions, 0 deletions

diff --git a/third_party/rust/zerocopy-derive/tests/enum_as_bytes.rs b/third_party/rust/zerocopy-derive/tests/enum_as_bytes.rs
new file mode 100644
index 0000000000..e305bc4cea
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/enum_as_bytes.rs
@@ -0,0 +1,101 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use {static_assertions::assert_impl_all, zerocopy::AsBytes};
+
+// An enum is `AsBytes` if if has a defined repr.
+
+#[derive(AsBytes)]
+#[repr(C)]
+enum C {
+    A,
+}
+
+assert_impl_all!(C: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(u8)]
+enum U8 {
+    A,
+}
+
+assert_impl_all!(U8: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(u16)]
+enum U16 {
+    A,
+}
+
+assert_impl_all!(U16: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(u32)]
+enum U32 {
+    A,
+}
+
+assert_impl_all!(U32: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(u64)]
+enum U64 {
+    A,
+}
+
+assert_impl_all!(U64: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(usize)]
+enum Usize {
+    A,
+}
+
+assert_impl_all!(Usize: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(i8)]
+enum I8 {
+    A,
+}
+
+assert_impl_all!(I8: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(i16)]
+enum I16 {
+    A,
+}
+
+assert_impl_all!(I16: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(i32)]
+enum I32 {
+    A,
+}
+
+assert_impl_all!(I32: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(i64)]
+enum I64 {
+    A,
+}
+
+assert_impl_all!(I64: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(isize)]
+enum Isize {
+    A,
+}
+
+assert_impl_all!(Isize: AsBytes);
diff --git a/third_party/rust/zerocopy-derive/tests/enum_from_zeroes.rs b/third_party/rust/zerocopy-derive/tests/enum_from_zeroes.rs
new file mode 100644
index 0000000000..c6bb675f52
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/enum_from_zeroes.rs
@@ -0,0 +1,35 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+mod util;
+
+use {static_assertions::assert_impl_all, zerocopy::FromZeroes};
+
+#[derive(FromZeroes)]
+enum Foo {
+    A,
+}
+
+assert_impl_all!(Foo: FromZeroes);
+
+#[derive(FromZeroes)]
+enum Bar {
+    A = 0,
+}
+
+assert_impl_all!(Bar: FromZeroes);
+
+#[derive(FromZeroes)]
+enum Baz {
+    A = 1,
+    B = 0,
+}
+
+assert_impl_all!(Baz: FromZeroes);
diff --git a/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs b/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs
new file mode 100644
index 0000000000..49a6765e53
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/enum_known_layout.rs
@@ -0,0 +1,46 @@
+// Copyright 2022 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![allow(warnings)]
+
+mod util;
+
+use {core::marker::PhantomData, static_assertions::assert_impl_all, zerocopy::KnownLayout};
+
+#[derive(KnownLayout)]
+enum Foo {
+    A,
+}
+
+assert_impl_all!(Foo: KnownLayout);
+
+#[derive(KnownLayout)]
+enum Bar {
+    A = 0,
+}
+
+assert_impl_all!(Bar: KnownLayout);
+
+#[derive(KnownLayout)]
+enum Baz {
+    A = 1,
+    B = 0,
+}
+
+assert_impl_all!(Baz: KnownLayout);
+
+// Deriving `KnownLayout` should work if the enum has bounded parameters.
+
+#[derive(KnownLayout)]
+#[repr(C)]
+enum WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + KnownLayout>
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + KnownLayout,
+{
+    Variant([T; N], PhantomData<&'a &'b ()>),
+}
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: KnownLayout);
diff --git a/third_party/rust/zerocopy-derive/tests/enum_unaligned.rs b/third_party/rust/zerocopy-derive/tests/enum_unaligned.rs
new file mode 100644
index 0000000000..152ce276b8
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/enum_unaligned.rs
@@ -0,0 +1,47 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use {static_assertions::assert_impl_all, zerocopy::Unaligned};
+
+// An enum is `Unaligned` if:
+// - No `repr(align(N > 1))`
+// - `repr(u8)` or `repr(i8)`
+
+#[derive(Unaligned)]
+#[repr(u8)]
+enum Foo {
+    A,
+}
+
+assert_impl_all!(Foo: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(i8)]
+enum Bar {
+    A,
+}
+
+assert_impl_all!(Bar: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(u8, align(1))]
+enum Baz {
+    A,
+}
+
+assert_impl_all!(Baz: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(i8, align(1))]
+enum Blah {
+    B,
+}
+
+assert_impl_all!(Blah: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/hygiene.rs b/third_party/rust/zerocopy-derive/tests/hygiene.rs
new file mode 100644
index 0000000000..b7b838d6c3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/hygiene.rs
@@ -0,0 +1,43 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+// Make sure that macro hygiene will ensure that when we reference "zerocopy",
+// that will work properly even if they've renamed the crate and have not
+// imported its traits.
+
+#![allow(warnings)]
+
+extern crate zerocopy as _zerocopy;
+
+#[macro_use]
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use static_assertions::assert_impl_all;
+
+#[derive(
+    _zerocopy::KnownLayout, _zerocopy::FromZeroes, _zerocopy::FromBytes, _zerocopy::Unaligned,
+)]
+#[repr(C)]
+struct TypeParams<'a, T, I: Iterator> {
+    a: T,
+    c: I::Item,
+    d: u8,
+    e: PhantomData<&'a [u8]>,
+    f: PhantomData<&'static str>,
+    g: PhantomData<String>,
+}
+
+assert_impl_all!(
+    TypeParams<'static, (), IntoIter<()>>:
+        _zerocopy::KnownLayout,
+        _zerocopy::FromZeroes,
+        _zerocopy::FromBytes,
+        _zerocopy::Unaligned
+);
diff --git a/third_party/rust/zerocopy-derive/tests/paths_and_modules.rs b/third_party/rust/zerocopy-derive/tests/paths_and_modules.rs
new file mode 100644
index 0000000000..a01983b097
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/paths_and_modules.rs
@@ -0,0 +1,38 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned};
+
+// Ensure that types that are use'd and types that are referenced by path work.
+
+mod foo {
+    use zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned};
+
+    #[derive(FromZeroes, FromBytes, AsBytes, Unaligned)]
+    #[repr(C)]
+    pub struct Foo {
+        foo: u8,
+    }
+
+    #[derive(FromZeroes, FromBytes, AsBytes, Unaligned)]
+    #[repr(C)]
+    pub struct Bar {
+        bar: u8,
+    }
+}
+
+use foo::Foo;
+
+#[derive(FromZeroes, FromBytes, AsBytes, Unaligned)]
+#[repr(C)]
+struct Baz {
+    foo: Foo,
+    bar: foo::Bar,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/priv_in_pub.rs b/third_party/rust/zerocopy-derive/tests/priv_in_pub.rs
new file mode 100644
index 0000000000..5f7d8749d3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/priv_in_pub.rs
@@ -0,0 +1,24 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+use zerocopy::{AsBytes, FromBytes, FromZeroes, KnownLayout, Unaligned};
+
+// These derives do not result in E0446 as of Rust 1.59.0, because of
+// https://github.com/rust-lang/rust/pull/90586.
+//
+// This change eliminates one of the major downsides of emitting `where`
+// bounds for field types (i.e., the emission of E0446 for private field
+// types).
+
+#[derive(KnownLayout, AsBytes, FromZeroes, FromBytes, Unaligned)]
+#[repr(C)]
+pub struct Public(Private);
+
+#[derive(KnownLayout, AsBytes, FromZeroes, FromBytes, Unaligned)]
+#[repr(C)]
+struct Private(());
diff --git a/third_party/rust/zerocopy-derive/tests/struct_as_bytes.rs b/third_party/rust/zerocopy-derive/tests/struct_as_bytes.rs
new file mode 100644
index 0000000000..3c71bf07b5
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/struct_as_bytes.rs
@@ -0,0 +1,161 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+mod util;
+
+use std::{marker::PhantomData, mem::ManuallyDrop, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::AsBytes};
+
+use self::util::AU16;
+
+// A struct is `AsBytes` if:
+// - all fields are `AsBytes`
+// - `repr(C)` or `repr(transparent)` and
+//   - no padding (size of struct equals sum of size of field types)
+// - `repr(packed)`
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct CZst;
+
+assert_impl_all!(CZst: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct C {
+    a: u8,
+    b: u8,
+    c: AU16,
+}
+
+assert_impl_all!(C: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(transparent)]
+struct Transparent {
+    a: u8,
+    b: CZst,
+}
+
+assert_impl_all!(Transparent: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(transparent)]
+struct TransparentGeneric<T: ?Sized> {
+    a: CZst,
+    b: T,
+}
+
+assert_impl_all!(TransparentGeneric<u64>: AsBytes);
+assert_impl_all!(TransparentGeneric<[u64]>: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+struct CZstPacked;
+
+assert_impl_all!(CZstPacked: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+struct CPacked {
+    a: u8,
+    // NOTE: The `u16` type is not guaranteed to have alignment 2, although it
+    // does on many platforms. However, to fix this would require a custom type
+    // with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not
+    // allowed to transitively contain `#[repr(align(...))]` types. Thus, we
+    // have no choice but to use `u16` here. Luckily, these tests run in CI on
+    // platforms on which `u16` has alignment 2, so this isn't that big of a
+    // deal.
+    b: u16,
+}
+
+assert_impl_all!(CPacked: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed(2))]
+// The same caveats as for CPacked apply - we're assuming u64 is at least
+// 4-byte aligned by default. Without packed(2), this should fail, as there
+// would be padding between a/b assuming u64 is 4+ byte aligned.
+struct CPacked2 {
+    a: u16,
+    b: u64,
+}
+
+assert_impl_all!(CPacked2: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+struct CPackedGeneric<T, U: ?Sized> {
+    t: T,
+    // Unsized types stored in `repr(packed)` structs must not be dropped
+    // because dropping them in-place might be unsound depending on the
+    // alignment of the outer struct. Sized types can be dropped by first being
+    // moved to an aligned stack variable, but this isn't possible with unsized
+    // types.
+    u: ManuallyDrop<U>,
+}
+
+assert_impl_all!(CPackedGeneric<u8, AU16>: AsBytes);
+assert_impl_all!(CPackedGeneric<u8, [AU16]>: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(packed)]
+struct Packed {
+    a: u8,
+    // NOTE: The `u16` type is not guaranteed to have alignment 2, although it
+    // does on many platforms. However, to fix this would require a custom type
+    // with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not
+    // allowed to transitively contain `#[repr(align(...))]` types. Thus, we
+    // have no choice but to use `u16` here. Luckily, these tests run in CI on
+    // platforms on which `u16` has alignment 2, so this isn't that big of a
+    // deal.
+    b: u16,
+}
+
+assert_impl_all!(Packed: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(packed)]
+struct PackedGeneric<T, U: ?Sized> {
+    t: T,
+    // Unsized types stored in `repr(packed)` structs must not be dropped
+    // because dropping them in-place might be unsound depending on the
+    // alignment of the outer struct. Sized types can be dropped by first being
+    // moved to an aligned stack variable, but this isn't possible with unsized
+    // types.
+    u: ManuallyDrop<U>,
+}
+
+assert_impl_all!(PackedGeneric<u8, AU16>: AsBytes);
+assert_impl_all!(PackedGeneric<u8, [AU16]>: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(transparent)]
+struct Unsized {
+    a: [u8],
+}
+
+assert_impl_all!(Unsized: AsBytes);
+
+// Deriving `AsBytes` should work if the struct has bounded parameters.
+
+#[derive(AsBytes)]
+#[repr(transparent)]
+struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + AsBytes>(
+    [T; N],
+    PhantomData<&'a &'b ()>,
+)
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + AsBytes;
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: AsBytes);
diff --git a/third_party/rust/zerocopy-derive/tests/struct_from_bytes.rs b/third_party/rust/zerocopy-derive/tests/struct_from_bytes.rs
new file mode 100644
index 0000000000..98f03d1640
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/struct_from_bytes.rs
@@ -0,0 +1,79 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{FromBytes, FromZeroes},
+};
+
+use crate::util::AU16;
+
+// A struct is `FromBytes` if:
+// - all fields are `FromBytes`
+
+#[derive(FromZeroes, FromBytes)]
+struct Zst;
+
+assert_impl_all!(Zst: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+struct One {
+    a: u8,
+}
+
+assert_impl_all!(One: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+struct Two {
+    a: u8,
+    b: Zst,
+}
+
+assert_impl_all!(Two: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+struct Unsized {
+    a: [u8],
+}
+
+assert_impl_all!(Unsized: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+struct TypeParams<'a, T: ?Sized, I: Iterator> {
+    a: I::Item,
+    b: u8,
+    c: PhantomData<&'a [u8]>,
+    d: PhantomData<&'static str>,
+    e: PhantomData<String>,
+    f: T,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: FromBytes);
+assert_impl_all!(TypeParams<'static, AU16, IntoIter<()>>: FromBytes);
+assert_impl_all!(TypeParams<'static, [AU16], IntoIter<()>>: FromBytes);
+
+// Deriving `FromBytes` should work if the struct has bounded parameters.
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(transparent)]
+struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + FromBytes>(
+    [T; N],
+    PhantomData<&'a &'b ()>,
+)
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + FromBytes;
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: FromBytes);
diff --git a/third_party/rust/zerocopy-derive/tests/struct_from_zeroes.rs b/third_party/rust/zerocopy-derive/tests/struct_from_zeroes.rs
new file mode 100644
index 0000000000..75d824594b
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/struct_from_zeroes.rs
@@ -0,0 +1,77 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+#[macro_use]
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::FromZeroes};
+
+use crate::util::AU16;
+
+// A struct is `FromZeroes` if:
+// - all fields are `FromZeroes`
+
+#[derive(FromZeroes)]
+struct Zst;
+
+assert_impl_all!(Zst: FromZeroes);
+
+#[derive(FromZeroes)]
+struct One {
+    a: bool,
+}
+
+assert_impl_all!(One: FromZeroes);
+
+#[derive(FromZeroes)]
+struct Two {
+    a: bool,
+    b: Zst,
+}
+
+assert_impl_all!(Two: FromZeroes);
+
+#[derive(FromZeroes)]
+struct Unsized {
+    a: [u8],
+}
+
+assert_impl_all!(Unsized: FromZeroes);
+
+#[derive(FromZeroes)]
+struct TypeParams<'a, T: ?Sized, I: Iterator> {
+    a: I::Item,
+    b: u8,
+    c: PhantomData<&'a [u8]>,
+    d: PhantomData<&'static str>,
+    e: PhantomData<String>,
+    f: T,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: FromZeroes);
+assert_impl_all!(TypeParams<'static, AU16, IntoIter<()>>: FromZeroes);
+assert_impl_all!(TypeParams<'static, [AU16], IntoIter<()>>: FromZeroes);
+
+// Deriving `FromZeroes` should work if the struct has bounded parameters.
+
+#[derive(FromZeroes)]
+#[repr(transparent)]
+struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + FromZeroes>(
+    [T; N],
+    PhantomData<&'a &'b ()>,
+)
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + FromZeroes;
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: FromZeroes);
diff --git a/third_party/rust/zerocopy-derive/tests/struct_known_layout.rs b/third_party/rust/zerocopy-derive/tests/struct_known_layout.rs
new file mode 100644
index 0000000000..68d1284de9
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/struct_known_layout.rs
@@ -0,0 +1,65 @@
+// Copyright 2022 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![allow(warnings)]
+
+#[macro_use]
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{DstLayout, KnownLayout},
+};
+
+use crate::util::AU16;
+
+#[derive(KnownLayout)]
+struct Zst;
+
+assert_impl_all!(Zst: KnownLayout);
+
+#[derive(KnownLayout)]
+struct One {
+    a: bool,
+}
+
+assert_impl_all!(One: KnownLayout);
+
+#[derive(KnownLayout)]
+struct Two {
+    a: bool,
+    b: Zst,
+}
+
+assert_impl_all!(Two: KnownLayout);
+
+#[derive(KnownLayout)]
+struct TypeParams<'a, T, I: Iterator> {
+    a: I::Item,
+    b: u8,
+    c: PhantomData<&'a [u8]>,
+    d: PhantomData<&'static str>,
+    e: PhantomData<String>,
+    f: T,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: KnownLayout);
+assert_impl_all!(TypeParams<'static, AU16, IntoIter<()>>: KnownLayout);
+
+// Deriving `KnownLayout` should work if the struct has bounded parameters.
+
+#[derive(KnownLayout)]
+#[repr(C)]
+struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + KnownLayout>(
+    [T; N],
+    PhantomData<&'a &'b ()>,
+)
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + KnownLayout;
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: KnownLayout);
diff --git a/third_party/rust/zerocopy-derive/tests/struct_unaligned.rs b/third_party/rust/zerocopy-derive/tests/struct_unaligned.rs
new file mode 100644
index 0000000000..a7db4322a6
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/struct_unaligned.rs
@@ -0,0 +1,100 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::Unaligned};
+
+use crate::util::AU16;
+
+// A struct is `Unaligned` if:
+// - `repr(align)` is no more than 1 and either
+//   - `repr(C)` or `repr(transparent)` and
+//     - all fields Unaligned
+//   - `repr(packed)`
+
+#[derive(Unaligned)]
+#[repr(C)]
+struct Foo {
+    a: u8,
+}
+
+assert_impl_all!(Foo: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct Bar {
+    a: u8,
+}
+
+assert_impl_all!(Bar: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(packed)]
+struct Baz {
+    // NOTE: The `u16` type is not guaranteed to have alignment 2, although it
+    // does on many platforms. However, to fix this would require a custom type
+    // with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not
+    // allowed to transitively contain `#[repr(align(...))]` types. Thus, we
+    // have no choice but to use `u16` here. Luckily, these tests run in CI on
+    // platforms on which `u16` has alignment 2, so this isn't that big of a
+    // deal.
+    a: u16,
+}
+
+assert_impl_all!(Baz: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(C, align(1))]
+struct FooAlign {
+    a: u8,
+}
+
+assert_impl_all!(FooAlign: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct Unsized {
+    a: [u8],
+}
+
+assert_impl_all!(Unsized: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(C)]
+struct TypeParams<'a, T: ?Sized, I: Iterator> {
+    a: I::Item,
+    b: u8,
+    c: PhantomData<&'a [u8]>,
+    d: PhantomData<&'static str>,
+    e: PhantomData<String>,
+    f: T,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: Unaligned);
+assert_impl_all!(TypeParams<'static, u8, IntoIter<()>>: Unaligned);
+assert_impl_all!(TypeParams<'static, [u8], IntoIter<()>>: Unaligned);
+
+// Deriving `Unaligned` should work if the struct has bounded parameters.
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + Unaligned>(
+    [T; N],
+    PhantomData<&'a &'b ()>,
+)
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + Unaligned;
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/trybuild.rs b/third_party/rust/zerocopy-derive/tests/trybuild.rs
new file mode 100644
index 0000000000..3ea1c3bfb8
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/trybuild.rs
@@ -0,0 +1,19 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[test]
+#[cfg_attr(miri, ignore)]
+fn ui() {
+    let version = testutil::ToolchainVersion::extract_from_pwd().unwrap();
+    // See the doc comment on this method for an explanation of what this does
+    // and why we store source files in different directories.
+    let source_files_dirname = version.get_ui_source_files_dirname_and_maybe_print_warning();
+
+    let t = trybuild::TestCases::new();
+    t.compile_fail(format!("tests/{source_files_dirname}/*.rs"));
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.rs
new file mode 100644
index 0000000000..2084d921bf
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.rs
@@ -0,0 +1,40 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use core::marker::PhantomData;
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned},
+};
+
+use self::util::NotZerocopy;
+
+fn main() {}
+
+// Test generic transparent structs
+
+#[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+#[repr(transparent)]
+struct TransparentStruct<T> {
+    inner: T,
+    _phantom: PhantomData<()>,
+}
+
+// It should be legal to derive these traits on a transparent struct, but it
+// must also ensure the traits are only implemented when the inner type
+// implements them.
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.stderr
new file mode 100644
index 0000000000..3b228b1551
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/derive_transparent.stderr
@@ -0,0 +1,71 @@
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-msrv/derive_transparent.rs:37:1
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+note: required because of the requirements on the impl of `FromZeroes` for `TransparentStruct<NotZerocopy>`
+  --> tests/ui-msrv/derive_transparent.rs:27:19
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                   ^^^^^^^^^^
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-msrv/derive_transparent.rs:37:1
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `_::{closure#0}::assert_impl_all`
+   = note: this error originates in the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-msrv/derive_transparent.rs:38:1
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+note: required because of the requirements on the impl of `FromBytes` for `TransparentStruct<NotZerocopy>`
+  --> tests/ui-msrv/derive_transparent.rs:27:31
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                               ^^^^^^^^^
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-msrv/derive_transparent.rs:38:1
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `_::{closure#0}::assert_impl_all`
+   = note: this error originates in the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-msrv/derive_transparent.rs:39:1
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+note: required because of the requirements on the impl of `AsBytes` for `TransparentStruct<NotZerocopy>`
+  --> tests/ui-msrv/derive_transparent.rs:27:10
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |          ^^^^^^^
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-msrv/derive_transparent.rs:39:1
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `_::{closure#0}::assert_impl_all`
+   = note: this error originates in the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: Unaligned` is not satisfied
+  --> tests/ui-msrv/derive_transparent.rs:40:1
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unaligned` is not implemented for `NotZerocopy`
+   |
+note: required because of the requirements on the impl of `Unaligned` for `TransparentStruct<NotZerocopy>`
+  --> tests/ui-msrv/derive_transparent.rs:27:42
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                                          ^^^^^^^^^
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-msrv/derive_transparent.rs:40:1
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `_::{closure#0}::assert_impl_all`
+   = note: this error originates in the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.rs
new file mode 100644
index 0000000000..31d5679d19
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.rs
@@ -0,0 +1,194 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+//
+// Generic errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr("foo")]
+enum Generic1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(foo)]
+enum Generic2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(transparent)]
+enum Generic3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u8, u16)]
+enum Generic4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+enum Generic5 {
+    A,
+}
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+enum FromZeroes1 {
+    A(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes2 {
+    A,
+    B(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes3 {
+    A = 1,
+    B,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(C)]
+enum FromBytes1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(usize)]
+enum FromBytes2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(isize)]
+enum FromBytes3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u32)]
+enum FromBytes4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i32)]
+enum FromBytes5 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u64)]
+enum FromBytes6 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i64)]
+enum FromBytes7 {
+    A,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+enum Unaligned1 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u16)]
+enum Unaligned2 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i16)]
+enum Unaligned3 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u32)]
+enum Unaligned4 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i32)]
+enum Unaligned5 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u64)]
+enum Unaligned6 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i64)]
+enum Unaligned7 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(usize)]
+enum Unaligned8 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(isize)]
+enum Unaligned9 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u8, align(2))]
+enum Unaligned10 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i8, align(2))]
+enum Unaligned11 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+enum Unaligned12 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+enum Unaligned13 {
+    A,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.stderr
new file mode 100644
index 0000000000..39bde3f9e3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum.stderr
@@ -0,0 +1,199 @@
+error: unrecognized representation hint
+  --> tests/ui-msrv/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error: unrecognized representation hint
+  --> tests/ui-msrv/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+
+error: unsupported representation for deriving FromBytes, AsBytes, or Unaligned on an enum
+  --> tests/ui-msrv/enum.rs:31:8
+   |
+31 | #[repr(transparent)]
+   |        ^^^^^^^^^^^
+
+error: conflicting representation hints
+  --> tests/ui-msrv/enum.rs:37:1
+   |
+37 | #[repr(u8, u16)]
+   | ^
+
+error: must have a non-align #[repr(...)] attribute in order to guarantee this type's memory layout
+  --> tests/ui-msrv/enum.rs:42:22
+   |
+42 | #[derive(FromZeroes, FromBytes)]
+   |                      ^^^^^^^^^
+   |
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-msrv/enum.rs:52:1
+   |
+52 | / enum FromZeroes1 {
+53 | |     A(u8),
+54 | | }
+   | |_^
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-msrv/enum.rs:57:1
+   |
+57 | / enum FromZeroes2 {
+58 | |     A,
+59 | |     B(u8),
+60 | | }
+   | |_^
+
+error: FromZeroes only supported on enums with a variant that has a discriminant of `0`
+  --> tests/ui-msrv/enum.rs:63:1
+   |
+63 | / enum FromZeroes3 {
+64 | |     A = 1,
+65 | |     B,
+66 | | }
+   | |_^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-msrv/enum.rs:73:8
+   |
+73 | #[repr(C)]
+   |        ^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-msrv/enum.rs:79:8
+   |
+79 | #[repr(usize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-msrv/enum.rs:85:8
+   |
+85 | #[repr(isize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-msrv/enum.rs:91:8
+   |
+91 | #[repr(u32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-msrv/enum.rs:97:8
+   |
+97 | #[repr(i32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-msrv/enum.rs:103:8
+    |
+103 | #[repr(u64)]
+    |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-msrv/enum.rs:109:8
+    |
+109 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:119:8
+    |
+119 | #[repr(C)]
+    |        ^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:125:8
+    |
+125 | #[repr(u16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:131:8
+    |
+131 | #[repr(i16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:137:8
+    |
+137 | #[repr(u32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:143:8
+    |
+143 | #[repr(i32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:149:8
+    |
+149 | #[repr(u64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:155:8
+    |
+155 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:161:8
+    |
+161 | #[repr(usize)]
+    |        ^^^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-msrv/enum.rs:167:8
+    |
+167 | #[repr(isize)]
+    |        ^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-msrv/enum.rs:173:12
+    |
+173 | #[repr(u8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-msrv/enum.rs:179:12
+    |
+179 | #[repr(i8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-msrv/enum.rs:185:18
+    |
+185 | #[repr(align(1), align(2))]
+    |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-msrv/enum.rs:191:8
+    |
+191 | #[repr(align(2), align(4))]
+    |        ^^^^^^^^
+
+error[E0565]: meta item in `repr` must be an identifier
+  --> tests/ui-msrv/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error[E0552]: unrecognized representation hint
+  --> tests/ui-msrv/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+
+error[E0566]: conflicting representation hints
+  --> tests/ui-msrv/enum.rs:37:8
+   |
+37 | #[repr(u8, u16)]
+   |        ^^  ^^^
+   |
+   = note: `#[deny(conflicting_repr_hints)]` on by default
+   = 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 #68585 <https://github.com/rust-lang/rust/issues/68585>
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.rs
new file mode 100644
index 0000000000..1b1bed31f3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.rs
@@ -0,0 +1,272 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+#[derive(FromBytes)]
+#[repr(u8)]
+enum Foo {
+    Variant0,
+    Variant1,
+    Variant2,
+    Variant3,
+    Variant4,
+    Variant5,
+    Variant6,
+    Variant7,
+    Variant8,
+    Variant9,
+    Variant10,
+    Variant11,
+    Variant12,
+    Variant13,
+    Variant14,
+    Variant15,
+    Variant16,
+    Variant17,
+    Variant18,
+    Variant19,
+    Variant20,
+    Variant21,
+    Variant22,
+    Variant23,
+    Variant24,
+    Variant25,
+    Variant26,
+    Variant27,
+    Variant28,
+    Variant29,
+    Variant30,
+    Variant31,
+    Variant32,
+    Variant33,
+    Variant34,
+    Variant35,
+    Variant36,
+    Variant37,
+    Variant38,
+    Variant39,
+    Variant40,
+    Variant41,
+    Variant42,
+    Variant43,
+    Variant44,
+    Variant45,
+    Variant46,
+    Variant47,
+    Variant48,
+    Variant49,
+    Variant50,
+    Variant51,
+    Variant52,
+    Variant53,
+    Variant54,
+    Variant55,
+    Variant56,
+    Variant57,
+    Variant58,
+    Variant59,
+    Variant60,
+    Variant61,
+    Variant62,
+    Variant63,
+    Variant64,
+    Variant65,
+    Variant66,
+    Variant67,
+    Variant68,
+    Variant69,
+    Variant70,
+    Variant71,
+    Variant72,
+    Variant73,
+    Variant74,
+    Variant75,
+    Variant76,
+    Variant77,
+    Variant78,
+    Variant79,
+    Variant80,
+    Variant81,
+    Variant82,
+    Variant83,
+    Variant84,
+    Variant85,
+    Variant86,
+    Variant87,
+    Variant88,
+    Variant89,
+    Variant90,
+    Variant91,
+    Variant92,
+    Variant93,
+    Variant94,
+    Variant95,
+    Variant96,
+    Variant97,
+    Variant98,
+    Variant99,
+    Variant100,
+    Variant101,
+    Variant102,
+    Variant103,
+    Variant104,
+    Variant105,
+    Variant106,
+    Variant107,
+    Variant108,
+    Variant109,
+    Variant110,
+    Variant111,
+    Variant112,
+    Variant113,
+    Variant114,
+    Variant115,
+    Variant116,
+    Variant117,
+    Variant118,
+    Variant119,
+    Variant120,
+    Variant121,
+    Variant122,
+    Variant123,
+    Variant124,
+    Variant125,
+    Variant126,
+    Variant127,
+    Variant128,
+    Variant129,
+    Variant130,
+    Variant131,
+    Variant132,
+    Variant133,
+    Variant134,
+    Variant135,
+    Variant136,
+    Variant137,
+    Variant138,
+    Variant139,
+    Variant140,
+    Variant141,
+    Variant142,
+    Variant143,
+    Variant144,
+    Variant145,
+    Variant146,
+    Variant147,
+    Variant148,
+    Variant149,
+    Variant150,
+    Variant151,
+    Variant152,
+    Variant153,
+    Variant154,
+    Variant155,
+    Variant156,
+    Variant157,
+    Variant158,
+    Variant159,
+    Variant160,
+    Variant161,
+    Variant162,
+    Variant163,
+    Variant164,
+    Variant165,
+    Variant166,
+    Variant167,
+    Variant168,
+    Variant169,
+    Variant170,
+    Variant171,
+    Variant172,
+    Variant173,
+    Variant174,
+    Variant175,
+    Variant176,
+    Variant177,
+    Variant178,
+    Variant179,
+    Variant180,
+    Variant181,
+    Variant182,
+    Variant183,
+    Variant184,
+    Variant185,
+    Variant186,
+    Variant187,
+    Variant188,
+    Variant189,
+    Variant190,
+    Variant191,
+    Variant192,
+    Variant193,
+    Variant194,
+    Variant195,
+    Variant196,
+    Variant197,
+    Variant198,
+    Variant199,
+    Variant200,
+    Variant201,
+    Variant202,
+    Variant203,
+    Variant204,
+    Variant205,
+    Variant206,
+    Variant207,
+    Variant208,
+    Variant209,
+    Variant210,
+    Variant211,
+    Variant212,
+    Variant213,
+    Variant214,
+    Variant215,
+    Variant216,
+    Variant217,
+    Variant218,
+    Variant219,
+    Variant220,
+    Variant221,
+    Variant222,
+    Variant223,
+    Variant224,
+    Variant225,
+    Variant226,
+    Variant227,
+    Variant228,
+    Variant229,
+    Variant230,
+    Variant231,
+    Variant232,
+    Variant233,
+    Variant234,
+    Variant235,
+    Variant236,
+    Variant237,
+    Variant238,
+    Variant239,
+    Variant240,
+    Variant241,
+    Variant242,
+    Variant243,
+    Variant244,
+    Variant245,
+    Variant246,
+    Variant247,
+    Variant248,
+    Variant249,
+    Variant250,
+    Variant251,
+    Variant252,
+    Variant253,
+    Variant254,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.stderr
new file mode 100644
index 0000000000..ff828dccba
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/enum_from_bytes_u8_too_few.stderr
@@ -0,0 +1,11 @@
+error: FromBytes only supported on repr(u8) enum with 256 variants
+   --> tests/ui-msrv/enum_from_bytes_u8_too_few.rs:15:1
+    |
+15  | / #[repr(u8)]
+16  | | enum Foo {
+17  | |     Variant0,
+18  | |     Variant1,
+...   |
+271 | |     Variant254,
+272 | | }
+    | |_^
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.rs
new file mode 100644
index 0000000000..cd65a6ed2c
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.rs
@@ -0,0 +1,75 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::{NotZerocopy, AU16};
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+struct FromZeroes1 {
+    value: NotZerocopy,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromBytes)]
+struct FromBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned1 {
+    aligned: AU16,
+}
+
+// This specifically tests a bug we had in an old version of the code in which
+// the trait bound would only be enforced for the first field's type.
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned2 {
+    unaligned: u8,
+    aligned: AU16,
+}
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct Unaligned3 {
+    aligned: AU16,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.stderr
new file mode 100644
index 0000000000..39dbcd1866
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/late_compile_pass.stderr
@@ -0,0 +1,74 @@
+warning: unused import: `zerocopy::KnownLayout`
+  --> tests/ui-msrv/late_compile_pass.rs:16:5
+   |
+16 | use zerocopy::KnownLayout;
+   |     ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unused_imports)]` on by default
+
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:28:10
+   |
+28 | #[derive(FromZeroes)]
+   |          ^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `FromZeroes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `FromBytes1: FromZeroes` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromZeroes` is not implemented for `FromBytes1`
+   |
+note: required by a bound in `FromBytes`
+  --> $WORKSPACE/src/lib.rs
+   |
+   | pub unsafe trait FromBytes: FromZeroes {
+   |                             ^^^^^^^^^^ required by this bound in `FromBytes`
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:46:10
+   |
+46 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:56:10
+   |
+56 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:64:10
+   |
+64 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-msrv/late_compile_pass.rs:71:10
+   |
+71 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.rs
new file mode 100644
index 0000000000..e0c4bc578d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.rs
@@ -0,0 +1,61 @@
+// Copyright 2023 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// KnownLayout errors
+//
+
+fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              N |        N |      KL04 |
+#[derive(KnownLayout)]
+struct KL04<T: ?Sized>(u8, T);
+
+fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              Y |        N |      KL06 |
+#[derive(KnownLayout)]
+struct KL06<T: ?Sized + KnownLayout>(u8, T);
+
+fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        N |      KL12 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL12<T: ?Sized>(u8, T);
+
+fn test_kl12<T: ?Sized>(kl: &KL12<T>) {
+    assert_kl(kl)
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        Y |      KL13 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL13<T>(u8, T);
+
+fn test_kl13<T>(t: T) -> impl KnownLayout {
+    KL13(0u8, t)
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.stderr
new file mode 100644
index 0000000000..5aa2cde0aa
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/mid_compile_pass.stderr
@@ -0,0 +1,104 @@
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-msrv/mid_compile_pass.rs:59:26
+   |
+59 | fn test_kl13<T>(t: T) -> impl KnownLayout {
+   |                          ^^^^^^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `T`
+   |
+note: required because of the requirements on the impl of `KnownLayout` for `KL13<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:55:10
+   |
+55 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider restricting type parameter `T`
+   |
+59 | fn test_kl13<T: zerocopy::KnownLayout>(t: T) -> impl KnownLayout {
+   |               +++++++++++++++++++++++
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-msrv/mid_compile_pass.rs:31:15
+   |
+30 | fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+   |              - this type parameter needs to be `std::marker::Sized`
+31 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL04<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:28:8
+   |
+28 | struct KL04<T: ?Sized>(u8, T);
+   |        ^^^^
+note: required because of the requirements on the impl of `KnownLayout` for `KL04<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:27:10
+   |
+27 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^
+note: required by a bound in `assert_kl`
+  --> tests/ui-msrv/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+30 - fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+30 + fn test_kl04<T>(kl: &KL04<T>) {
+   |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-msrv/mid_compile_pass.rs:40:15
+   |
+39 | fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+   |              - this type parameter needs to be `std::marker::Sized`
+40 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL06<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:37:8
+   |
+37 | struct KL06<T: ?Sized + KnownLayout>(u8, T);
+   |        ^^^^
+note: required because of the requirements on the impl of `KnownLayout` for `KL06<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^
+note: required by a bound in `assert_kl`
+  --> tests/ui-msrv/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+39 - fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+39 + fn test_kl06<T: KnownLayout>(kl: &KL06<T>) {
+   |
+
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-msrv/mid_compile_pass.rs:50:15
+   |
+50 |     assert_kl(kl)
+   |     --------- ^^ the trait `KnownLayout` is not implemented for `T`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because of the requirements on the impl of `KnownLayout` for `KL12<T>`
+  --> tests/ui-msrv/mid_compile_pass.rs:45:10
+   |
+45 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^
+note: required by a bound in `assert_kl`
+  --> tests/ui-msrv/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider further restricting this bound
+   |
+49 | fn test_kl12<T: ?Sized + zerocopy::KnownLayout>(kl: &KL12<T>) {
+   |                        +++++++++++++++++++++++
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.rs
new file mode 100644
index 0000000000..c76dc7f952
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.rs
@@ -0,0 +1,99 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use zerocopy::KnownLayout;
+
+use self::util::AU16;
+
+fn main() {}
+
+//
+// KnownLayout errors
+//
+
+struct NotKnownLayout;
+
+struct NotKnownLayoutDst([u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              N |        N |      KL00 |
+#[derive(KnownLayout)]
+struct KL00(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              Y |        N |      KL02 |
+#[derive(KnownLayout)]
+struct KL02(u8, [u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        N |      KL08 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL08(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        Y |      KL09 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL09(NotKnownLayout, NotKnownLayout);
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1<T>(T);
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes2 {
+    foo: u8,
+    bar: AU16,
+}
+
+#[derive(AsBytes)]
+#[repr(C, packed(2))]
+struct AsBytes3 {
+    foo: u8,
+    // We'd prefer to use AU64 here, but you can't use aligned types in
+    // packed structs.
+    bar: u64,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+struct Unaligned1;
+
+#[derive(Unaligned)]
+#[repr(transparent, align(2))]
+struct Unaligned2 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+struct Unaligned3;
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4;
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5;
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.stderr
new file mode 100644
index 0000000000..f4a435d5f5
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/struct.stderr
@@ -0,0 +1,113 @@
+error: unsupported on generic structs that are not repr(transparent) or repr(packed)
+  --> tests/ui-msrv/struct.rs:55:10
+   |
+55 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/struct.rs:80:11
+   |
+80 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/struct.rs:84:21
+   |
+84 | #[repr(transparent, align(2))]
+   |                     ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/struct.rs:90:16
+   |
+90 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/struct.rs:94:18
+   |
+94 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/struct.rs:98:8
+   |
+98 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0692]: transparent struct cannot have other repr hints
+  --> tests/ui-msrv/struct.rs:84:8
+   |
+84 | #[repr(transparent, align(2))]
+   |        ^^^^^^^^^^^  ^^^^^^^^
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-msrv/struct.rs:31:10
+   |
+31 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL00`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL00`
+  --> tests/ui-msrv/struct.rs:32:8
+   |
+32 | struct KL00(u8, NotKnownLayoutDst);
+   |        ^^^^
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-msrv/struct.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL02`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL02`
+  --> tests/ui-msrv/struct.rs:37:8
+   |
+37 | struct KL02(u8, [u8]);
+   |        ^^^^
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayoutDst: KnownLayout` is not satisfied
+  --> tests/ui-msrv/struct.rs:41:10
+   |
+41 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayoutDst`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayout: KnownLayout` is not satisfied
+  --> tests/ui-msrv/struct.rs:47:10
+   |
+47 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayout`
+   |
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-msrv/struct.rs:59:10
+   |
+59 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the following implementations were found:
+             <HasPadding<T, VALUE> as ShouldBe<VALUE>>
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes3, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-msrv/struct.rs:66:10
+   |
+66 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes3, true>`
+   |
+   = help: the following implementations were found:
+             <HasPadding<T, VALUE> as ShouldBe<VALUE>>
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/union.rs b/third_party/rust/zerocopy-derive/tests/ui-msrv/union.rs
new file mode 100644
index 0000000000..8938e78478
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/union.rs
@@ -0,0 +1,73 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::AU16;
+use std::mem::ManuallyDrop;
+
+fn main() {}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes1<T> {
+    foo: ManuallyDrop<T>,
+}
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes2 {
+    foo: u8,
+    bar: [u8; 2],
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+union Unaligned1 {
+    foo: i16,
+    bar: AU16,
+}
+
+// Transparent unions are unstable; see issue #60405
+// <https://github.com/rust-lang/rust/issues/60405> for more information.
+
+// #[derive(Unaligned)]
+// #[repr(transparent, align(2))]
+// union Unaligned2 {
+//     foo: u8,
+// }
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+union Unaligned3 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5 {
+    foo: u8,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-msrv/union.stderr b/third_party/rust/zerocopy-derive/tests/ui-msrv/union.stderr
new file mode 100644
index 0000000000..3e13059211
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-msrv/union.stderr
@@ -0,0 +1,42 @@
+error: unsupported on types with type parameters
+  --> tests/ui-msrv/union.rs:24:10
+   |
+24 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/union.rs:42:11
+   |
+42 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/union.rs:58:16
+   |
+58 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/union.rs:64:18
+   |
+64 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-msrv/union.rs:70:8
+   |
+70 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-msrv/union.rs:30:10
+   |
+30 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the following implementations were found:
+             <HasPadding<T, VALUE> as ShouldBe<VALUE>>
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.rs
new file mode 100644
index 0000000000..2084d921bf
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.rs
@@ -0,0 +1,40 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use core::marker::PhantomData;
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned},
+};
+
+use self::util::NotZerocopy;
+
+fn main() {}
+
+// Test generic transparent structs
+
+#[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+#[repr(transparent)]
+struct TransparentStruct<T> {
+    inner: T,
+    _phantom: PhantomData<()>,
+}
+
+// It should be legal to derive these traits on a transparent struct, but it
+// must also ensure the traits are only implemented when the inner type
+// implements them.
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.stderr
new file mode 100644
index 0000000000..f214877dfb
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/derive_transparent.stderr
@@ -0,0 +1,111 @@
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-nightly/derive_transparent.rs:37:18
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `FromZeroes`
+  --> tests/ui-nightly/derive_transparent.rs:27:19
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                   ^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-nightly/derive_transparent.rs:37:1
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `FromZeroes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-nightly/derive_transparent.rs:38:18
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromBytes`:
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+             usize
+             u8
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `FromBytes`
+  --> tests/ui-nightly/derive_transparent.rs:27:31
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                               ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-nightly/derive_transparent.rs:38:1
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `FromBytes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-nightly/derive_transparent.rs:39:18
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `AsBytes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `AsBytes`
+  --> tests/ui-nightly/derive_transparent.rs:27:10
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |          ^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-nightly/derive_transparent.rs:39:1
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `AsBytes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: Unaligned` is not satisfied
+  --> tests/ui-nightly/derive_transparent.rs:40:18
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unaligned` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             TransparentStruct<T>
+             U16<O>
+             U32<O>
+             U64<O>
+             U128<O>
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `Unaligned`
+  --> tests/ui-nightly/derive_transparent.rs:27:42
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                                          ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-nightly/derive_transparent.rs:40:1
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `Unaligned` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.rs
new file mode 100644
index 0000000000..31d5679d19
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.rs
@@ -0,0 +1,194 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+//
+// Generic errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr("foo")]
+enum Generic1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(foo)]
+enum Generic2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(transparent)]
+enum Generic3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u8, u16)]
+enum Generic4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+enum Generic5 {
+    A,
+}
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+enum FromZeroes1 {
+    A(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes2 {
+    A,
+    B(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes3 {
+    A = 1,
+    B,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(C)]
+enum FromBytes1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(usize)]
+enum FromBytes2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(isize)]
+enum FromBytes3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u32)]
+enum FromBytes4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i32)]
+enum FromBytes5 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u64)]
+enum FromBytes6 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i64)]
+enum FromBytes7 {
+    A,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+enum Unaligned1 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u16)]
+enum Unaligned2 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i16)]
+enum Unaligned3 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u32)]
+enum Unaligned4 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i32)]
+enum Unaligned5 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u64)]
+enum Unaligned6 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i64)]
+enum Unaligned7 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(usize)]
+enum Unaligned8 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(isize)]
+enum Unaligned9 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u8, align(2))]
+enum Unaligned10 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i8, align(2))]
+enum Unaligned11 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+enum Unaligned12 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+enum Unaligned13 {
+    A,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.stderr
new file mode 100644
index 0000000000..a4d5edf35f
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum.stderr
@@ -0,0 +1,201 @@
+error: unrecognized representation hint
+  --> tests/ui-nightly/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error: unrecognized representation hint
+  --> tests/ui-nightly/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+
+error: unsupported representation for deriving FromBytes, AsBytes, or Unaligned on an enum
+  --> tests/ui-nightly/enum.rs:31:8
+   |
+31 | #[repr(transparent)]
+   |        ^^^^^^^^^^^
+
+error: conflicting representation hints
+  --> tests/ui-nightly/enum.rs:37:8
+   |
+37 | #[repr(u8, u16)]
+   |        ^^^^^^^
+
+error: must have a non-align #[repr(...)] attribute in order to guarantee this type's memory layout
+  --> tests/ui-nightly/enum.rs:42:22
+   |
+42 | #[derive(FromZeroes, FromBytes)]
+   |                      ^^^^^^^^^
+   |
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-nightly/enum.rs:52:1
+   |
+52 | / enum FromZeroes1 {
+53 | |     A(u8),
+54 | | }
+   | |_^
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-nightly/enum.rs:57:1
+   |
+57 | / enum FromZeroes2 {
+58 | |     A,
+59 | |     B(u8),
+60 | | }
+   | |_^
+
+error: FromZeroes only supported on enums with a variant that has a discriminant of `0`
+  --> tests/ui-nightly/enum.rs:63:1
+   |
+63 | / enum FromZeroes3 {
+64 | |     A = 1,
+65 | |     B,
+66 | | }
+   | |_^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-nightly/enum.rs:73:8
+   |
+73 | #[repr(C)]
+   |        ^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-nightly/enum.rs:79:8
+   |
+79 | #[repr(usize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-nightly/enum.rs:85:8
+   |
+85 | #[repr(isize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-nightly/enum.rs:91:8
+   |
+91 | #[repr(u32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-nightly/enum.rs:97:8
+   |
+97 | #[repr(i32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-nightly/enum.rs:103:8
+    |
+103 | #[repr(u64)]
+    |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-nightly/enum.rs:109:8
+    |
+109 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:119:8
+    |
+119 | #[repr(C)]
+    |        ^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:125:8
+    |
+125 | #[repr(u16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:131:8
+    |
+131 | #[repr(i16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:137:8
+    |
+137 | #[repr(u32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:143:8
+    |
+143 | #[repr(i32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:149:8
+    |
+149 | #[repr(u64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:155:8
+    |
+155 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:161:8
+    |
+161 | #[repr(usize)]
+    |        ^^^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-nightly/enum.rs:167:8
+    |
+167 | #[repr(isize)]
+    |        ^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-nightly/enum.rs:173:12
+    |
+173 | #[repr(u8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-nightly/enum.rs:179:12
+    |
+179 | #[repr(i8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-nightly/enum.rs:185:18
+    |
+185 | #[repr(align(1), align(2))]
+    |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-nightly/enum.rs:191:8
+    |
+191 | #[repr(align(2), align(4))]
+    |        ^^^^^^^^
+
+error[E0565]: meta item in `repr` must be an identifier
+  --> tests/ui-nightly/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error[E0552]: unrecognized representation hint
+  --> tests/ui-nightly/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+   |
+   = help: valid reprs are `Rust` (default), `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`
+
+error[E0566]: conflicting representation hints
+  --> tests/ui-nightly/enum.rs:37:8
+   |
+37 | #[repr(u8, u16)]
+   |        ^^  ^^^
+   |
+   = 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 #68585 <https://github.com/rust-lang/rust/issues/68585>
+   = note: `#[deny(conflicting_repr_hints)]` on by default
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.rs
new file mode 100644
index 0000000000..1b1bed31f3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.rs
@@ -0,0 +1,272 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+#[derive(FromBytes)]
+#[repr(u8)]
+enum Foo {
+    Variant0,
+    Variant1,
+    Variant2,
+    Variant3,
+    Variant4,
+    Variant5,
+    Variant6,
+    Variant7,
+    Variant8,
+    Variant9,
+    Variant10,
+    Variant11,
+    Variant12,
+    Variant13,
+    Variant14,
+    Variant15,
+    Variant16,
+    Variant17,
+    Variant18,
+    Variant19,
+    Variant20,
+    Variant21,
+    Variant22,
+    Variant23,
+    Variant24,
+    Variant25,
+    Variant26,
+    Variant27,
+    Variant28,
+    Variant29,
+    Variant30,
+    Variant31,
+    Variant32,
+    Variant33,
+    Variant34,
+    Variant35,
+    Variant36,
+    Variant37,
+    Variant38,
+    Variant39,
+    Variant40,
+    Variant41,
+    Variant42,
+    Variant43,
+    Variant44,
+    Variant45,
+    Variant46,
+    Variant47,
+    Variant48,
+    Variant49,
+    Variant50,
+    Variant51,
+    Variant52,
+    Variant53,
+    Variant54,
+    Variant55,
+    Variant56,
+    Variant57,
+    Variant58,
+    Variant59,
+    Variant60,
+    Variant61,
+    Variant62,
+    Variant63,
+    Variant64,
+    Variant65,
+    Variant66,
+    Variant67,
+    Variant68,
+    Variant69,
+    Variant70,
+    Variant71,
+    Variant72,
+    Variant73,
+    Variant74,
+    Variant75,
+    Variant76,
+    Variant77,
+    Variant78,
+    Variant79,
+    Variant80,
+    Variant81,
+    Variant82,
+    Variant83,
+    Variant84,
+    Variant85,
+    Variant86,
+    Variant87,
+    Variant88,
+    Variant89,
+    Variant90,
+    Variant91,
+    Variant92,
+    Variant93,
+    Variant94,
+    Variant95,
+    Variant96,
+    Variant97,
+    Variant98,
+    Variant99,
+    Variant100,
+    Variant101,
+    Variant102,
+    Variant103,
+    Variant104,
+    Variant105,
+    Variant106,
+    Variant107,
+    Variant108,
+    Variant109,
+    Variant110,
+    Variant111,
+    Variant112,
+    Variant113,
+    Variant114,
+    Variant115,
+    Variant116,
+    Variant117,
+    Variant118,
+    Variant119,
+    Variant120,
+    Variant121,
+    Variant122,
+    Variant123,
+    Variant124,
+    Variant125,
+    Variant126,
+    Variant127,
+    Variant128,
+    Variant129,
+    Variant130,
+    Variant131,
+    Variant132,
+    Variant133,
+    Variant134,
+    Variant135,
+    Variant136,
+    Variant137,
+    Variant138,
+    Variant139,
+    Variant140,
+    Variant141,
+    Variant142,
+    Variant143,
+    Variant144,
+    Variant145,
+    Variant146,
+    Variant147,
+    Variant148,
+    Variant149,
+    Variant150,
+    Variant151,
+    Variant152,
+    Variant153,
+    Variant154,
+    Variant155,
+    Variant156,
+    Variant157,
+    Variant158,
+    Variant159,
+    Variant160,
+    Variant161,
+    Variant162,
+    Variant163,
+    Variant164,
+    Variant165,
+    Variant166,
+    Variant167,
+    Variant168,
+    Variant169,
+    Variant170,
+    Variant171,
+    Variant172,
+    Variant173,
+    Variant174,
+    Variant175,
+    Variant176,
+    Variant177,
+    Variant178,
+    Variant179,
+    Variant180,
+    Variant181,
+    Variant182,
+    Variant183,
+    Variant184,
+    Variant185,
+    Variant186,
+    Variant187,
+    Variant188,
+    Variant189,
+    Variant190,
+    Variant191,
+    Variant192,
+    Variant193,
+    Variant194,
+    Variant195,
+    Variant196,
+    Variant197,
+    Variant198,
+    Variant199,
+    Variant200,
+    Variant201,
+    Variant202,
+    Variant203,
+    Variant204,
+    Variant205,
+    Variant206,
+    Variant207,
+    Variant208,
+    Variant209,
+    Variant210,
+    Variant211,
+    Variant212,
+    Variant213,
+    Variant214,
+    Variant215,
+    Variant216,
+    Variant217,
+    Variant218,
+    Variant219,
+    Variant220,
+    Variant221,
+    Variant222,
+    Variant223,
+    Variant224,
+    Variant225,
+    Variant226,
+    Variant227,
+    Variant228,
+    Variant229,
+    Variant230,
+    Variant231,
+    Variant232,
+    Variant233,
+    Variant234,
+    Variant235,
+    Variant236,
+    Variant237,
+    Variant238,
+    Variant239,
+    Variant240,
+    Variant241,
+    Variant242,
+    Variant243,
+    Variant244,
+    Variant245,
+    Variant246,
+    Variant247,
+    Variant248,
+    Variant249,
+    Variant250,
+    Variant251,
+    Variant252,
+    Variant253,
+    Variant254,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.stderr
new file mode 100644
index 0000000000..50cf0e7cb8
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/enum_from_bytes_u8_too_few.stderr
@@ -0,0 +1,11 @@
+error: FromBytes only supported on repr(u8) enum with 256 variants
+   --> tests/ui-nightly/enum_from_bytes_u8_too_few.rs:15:1
+    |
+15  | / #[repr(u8)]
+16  | | enum Foo {
+17  | |     Variant0,
+18  | |     Variant1,
+...   |
+271 | |     Variant254,
+272 | | }
+    | |_^
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.rs
new file mode 100644
index 0000000000..cd65a6ed2c
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.rs
@@ -0,0 +1,75 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::{NotZerocopy, AU16};
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+struct FromZeroes1 {
+    value: NotZerocopy,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromBytes)]
+struct FromBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned1 {
+    aligned: AU16,
+}
+
+// This specifically tests a bug we had in an old version of the code in which
+// the trait bound would only be enforced for the first field's type.
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned2 {
+    unaligned: u8,
+    aligned: AU16,
+}
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct Unaligned3 {
+    aligned: AU16,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.stderr
new file mode 100644
index 0000000000..3c45dc4e84
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/late_compile_pass.stderr
@@ -0,0 +1,150 @@
+warning: unused import: `zerocopy::KnownLayout`
+  --> tests/ui-nightly/late_compile_pass.rs:16:5
+   |
+16 | use zerocopy::KnownLayout;
+   |     ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unused_imports)]` on by default
+
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:28:10
+   |
+28 | #[derive(FromZeroes)]
+   |          ^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `FromZeroes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromBytes`:
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+             usize
+             u8
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `FromBytes1: FromZeroes` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromZeroes` is not implemented for `FromBytes1`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required by a bound in `FromBytes`
+  --> $WORKSPACE/src/lib.rs
+   |
+   | pub unsafe trait FromBytes: FromZeroes {
+   |                             ^^^^^^^^^^ required by this bound in `FromBytes`
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:46:10
+   |
+46 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `AsBytes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:56:10
+   |
+56 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:64:10
+   |
+64 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-nightly/late_compile_pass.rs:71:10
+   |
+71 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.rs
new file mode 100644
index 0000000000..e0c4bc578d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.rs
@@ -0,0 +1,61 @@
+// Copyright 2023 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// KnownLayout errors
+//
+
+fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              N |        N |      KL04 |
+#[derive(KnownLayout)]
+struct KL04<T: ?Sized>(u8, T);
+
+fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              Y |        N |      KL06 |
+#[derive(KnownLayout)]
+struct KL06<T: ?Sized + KnownLayout>(u8, T);
+
+fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        N |      KL12 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL12<T: ?Sized>(u8, T);
+
+fn test_kl12<T: ?Sized>(kl: &KL12<T>) {
+    assert_kl(kl)
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        Y |      KL13 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL13<T>(u8, T);
+
+fn test_kl13<T>(t: T) -> impl KnownLayout {
+    KL13(0u8, t)
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.stderr
new file mode 100644
index 0000000000..7fd758c8fe
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/mid_compile_pass.stderr
@@ -0,0 +1,104 @@
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-nightly/mid_compile_pass.rs:59:26
+   |
+59 | fn test_kl13<T>(t: T) -> impl KnownLayout {
+   |                          ^^^^^^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `T`
+   |
+note: required for `KL13<T>` to implement `KnownLayout`
+  --> tests/ui-nightly/mid_compile_pass.rs:55:10
+   |
+55 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider restricting type parameter `T`
+   |
+59 | fn test_kl13<T: zerocopy::KnownLayout>(t: T) -> impl KnownLayout {
+   |               +++++++++++++++++++++++
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-nightly/mid_compile_pass.rs:31:15
+   |
+30 | fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+   |              - this type parameter needs to be `Sized`
+31 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL04<T>`
+  --> tests/ui-nightly/mid_compile_pass.rs:28:8
+   |
+28 | struct KL04<T: ?Sized>(u8, T);
+   |        ^^^^
+note: required for `KL04<T>` to implement `KnownLayout`
+  --> tests/ui-nightly/mid_compile_pass.rs:27:10
+   |
+27 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-nightly/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+30 - fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+30 + fn test_kl04<T>(kl: &KL04<T>) {
+   |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-nightly/mid_compile_pass.rs:40:15
+   |
+39 | fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+   |              - this type parameter needs to be `Sized`
+40 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL06<T>`
+  --> tests/ui-nightly/mid_compile_pass.rs:37:8
+   |
+37 | struct KL06<T: ?Sized + KnownLayout>(u8, T);
+   |        ^^^^
+note: required for `KL06<T>` to implement `KnownLayout`
+  --> tests/ui-nightly/mid_compile_pass.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-nightly/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+39 - fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+39 + fn test_kl06<T: KnownLayout>(kl: &KL06<T>) {
+   |
+
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-nightly/mid_compile_pass.rs:50:15
+   |
+50 |     assert_kl(kl)
+   |     --------- ^^ the trait `KnownLayout` is not implemented for `T`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required for `KL12<T>` to implement `KnownLayout`
+  --> tests/ui-nightly/mid_compile_pass.rs:45:10
+   |
+45 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-nightly/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider further restricting this bound
+   |
+49 | fn test_kl12<T: ?Sized + zerocopy::KnownLayout>(kl: &KL12<T>) {
+   |                        +++++++++++++++++++++++
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.rs
new file mode 100644
index 0000000000..c76dc7f952
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.rs
@@ -0,0 +1,99 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use zerocopy::KnownLayout;
+
+use self::util::AU16;
+
+fn main() {}
+
+//
+// KnownLayout errors
+//
+
+struct NotKnownLayout;
+
+struct NotKnownLayoutDst([u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              N |        N |      KL00 |
+#[derive(KnownLayout)]
+struct KL00(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              Y |        N |      KL02 |
+#[derive(KnownLayout)]
+struct KL02(u8, [u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        N |      KL08 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL08(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        Y |      KL09 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL09(NotKnownLayout, NotKnownLayout);
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1<T>(T);
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes2 {
+    foo: u8,
+    bar: AU16,
+}
+
+#[derive(AsBytes)]
+#[repr(C, packed(2))]
+struct AsBytes3 {
+    foo: u8,
+    // We'd prefer to use AU64 here, but you can't use aligned types in
+    // packed structs.
+    bar: u64,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+struct Unaligned1;
+
+#[derive(Unaligned)]
+#[repr(transparent, align(2))]
+struct Unaligned2 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+struct Unaligned3;
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4;
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5;
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.stderr
new file mode 100644
index 0000000000..c3abcbd182
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/struct.stderr
@@ -0,0 +1,143 @@
+error: unsupported on generic structs that are not repr(transparent) or repr(packed)
+  --> tests/ui-nightly/struct.rs:55:10
+   |
+55 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/struct.rs:80:11
+   |
+80 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/struct.rs:84:21
+   |
+84 | #[repr(transparent, align(2))]
+   |                     ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/struct.rs:90:16
+   |
+90 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/struct.rs:94:18
+   |
+94 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/struct.rs:98:8
+   |
+98 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0692]: transparent struct cannot have other repr hints
+  --> tests/ui-nightly/struct.rs:84:8
+   |
+84 | #[repr(transparent, align(2))]
+   |        ^^^^^^^^^^^  ^^^^^^^^
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-nightly/struct.rs:31:10
+   |
+31 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL00`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL00`
+  --> tests/ui-nightly/struct.rs:32:8
+   |
+32 | struct KL00(u8, NotKnownLayoutDst);
+   |        ^^^^
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-nightly/struct.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL02`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL02`
+  --> tests/ui-nightly/struct.rs:37:8
+   |
+37 | struct KL02(u8, [u8]);
+   |        ^^^^
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayoutDst: KnownLayout` is not satisfied
+  --> tests/ui-nightly/struct.rs:41:10
+   |
+41 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayoutDst`
+   |
+   = help: the following other types implement trait `KnownLayout`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayout: KnownLayout` is not satisfied
+  --> tests/ui-nightly/struct.rs:47:10
+   |
+47 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayout`
+   |
+   = help: the following other types implement trait `KnownLayout`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-nightly/struct.rs:59:10
+   |
+59 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the trait `ShouldBe<true>` is implemented for `HasPadding<AsBytes2, true>`
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes3, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-nightly/struct.rs:66:10
+   |
+66 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes3, true>`
+   |
+   = help: the trait `ShouldBe<true>` is implemented for `HasPadding<AsBytes3, true>`
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0587]: type has conflicting packed and align representation hints
+  --> tests/ui-nightly/struct.rs:91:1
+   |
+91 | struct Unaligned3;
+   | ^^^^^^^^^^^^^^^^^
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/union.rs b/third_party/rust/zerocopy-derive/tests/ui-nightly/union.rs
new file mode 100644
index 0000000000..8938e78478
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/union.rs
@@ -0,0 +1,73 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::AU16;
+use std::mem::ManuallyDrop;
+
+fn main() {}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes1<T> {
+    foo: ManuallyDrop<T>,
+}
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes2 {
+    foo: u8,
+    bar: [u8; 2],
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+union Unaligned1 {
+    foo: i16,
+    bar: AU16,
+}
+
+// Transparent unions are unstable; see issue #60405
+// <https://github.com/rust-lang/rust/issues/60405> for more information.
+
+// #[derive(Unaligned)]
+// #[repr(transparent, align(2))]
+// union Unaligned2 {
+//     foo: u8,
+// }
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+union Unaligned3 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5 {
+    foo: u8,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-nightly/union.stderr b/third_party/rust/zerocopy-derive/tests/ui-nightly/union.stderr
new file mode 100644
index 0000000000..afc4e8c18d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-nightly/union.stderr
@@ -0,0 +1,48 @@
+error: unsupported on types with type parameters
+  --> tests/ui-nightly/union.rs:24:10
+   |
+24 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/union.rs:42:11
+   |
+42 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/union.rs:58:16
+   |
+58 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/union.rs:64:18
+   |
+64 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-nightly/union.rs:70:8
+   |
+70 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-nightly/union.rs:30:10
+   |
+30 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the trait `ShouldBe<true>` is implemented for `HasPadding<AsBytes2, true>`
+   = help: see issue #48214
+   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0587]: type has conflicting packed and align representation hints
+  --> tests/ui-nightly/union.rs:59:1
+   |
+59 | union Unaligned3 {
+   | ^^^^^^^^^^^^^^^^
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.rs
new file mode 100644
index 0000000000..2084d921bf
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.rs
@@ -0,0 +1,40 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use core::marker::PhantomData;
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned},
+};
+
+use self::util::NotZerocopy;
+
+fn main() {}
+
+// Test generic transparent structs
+
+#[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+#[repr(transparent)]
+struct TransparentStruct<T> {
+    inner: T,
+    _phantom: PhantomData<()>,
+}
+
+// It should be legal to derive these traits on a transparent struct, but it
+// must also ensure the traits are only implemented when the inner type
+// implements them.
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.stderr
new file mode 100644
index 0000000000..f24dd4866d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/derive_transparent.stderr
@@ -0,0 +1,111 @@
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-stable/derive_transparent.rs:37:18
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `FromZeroes`
+  --> tests/ui-stable/derive_transparent.rs:27:19
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                   ^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-stable/derive_transparent.rs:37:1
+   |
+37 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromZeroes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `FromZeroes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-stable/derive_transparent.rs:38:18
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromBytes`:
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+             usize
+             u8
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `FromBytes`
+  --> tests/ui-stable/derive_transparent.rs:27:31
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                               ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-stable/derive_transparent.rs:38:1
+   |
+38 | assert_impl_all!(TransparentStruct<NotZerocopy>: FromBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `FromBytes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-stable/derive_transparent.rs:39:18
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `AsBytes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `AsBytes`
+  --> tests/ui-stable/derive_transparent.rs:27:10
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |          ^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-stable/derive_transparent.rs:39:1
+   |
+39 | assert_impl_all!(TransparentStruct<NotZerocopy>: AsBytes);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `AsBytes` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: Unaligned` is not satisfied
+  --> tests/ui-stable/derive_transparent.rs:40:18
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unaligned` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             TransparentStruct<T>
+             U16<O>
+             U32<O>
+             U64<O>
+             U128<O>
+           and $N others
+note: required for `TransparentStruct<NotZerocopy>` to implement `Unaligned`
+  --> tests/ui-stable/derive_transparent.rs:27:42
+   |
+27 | #[derive(AsBytes, FromZeroes, FromBytes, Unaligned)]
+   |                                          ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `_::{closure#0}::assert_impl_all`
+  --> tests/ui-stable/derive_transparent.rs:40:1
+   |
+40 | assert_impl_all!(TransparentStruct<NotZerocopy>: Unaligned);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `assert_impl_all`
+   = note: this error originates in the derive macro `Unaligned` which comes from the expansion of the macro `assert_impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/enum.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/enum.rs
new file mode 100644
index 0000000000..31d5679d19
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/enum.rs
@@ -0,0 +1,194 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+//
+// Generic errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr("foo")]
+enum Generic1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(foo)]
+enum Generic2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(transparent)]
+enum Generic3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u8, u16)]
+enum Generic4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+enum Generic5 {
+    A,
+}
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+enum FromZeroes1 {
+    A(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes2 {
+    A,
+    B(u8),
+}
+
+#[derive(FromZeroes)]
+enum FromZeroes3 {
+    A = 1,
+    B,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(C)]
+enum FromBytes1 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(usize)]
+enum FromBytes2 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(isize)]
+enum FromBytes3 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u32)]
+enum FromBytes4 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i32)]
+enum FromBytes5 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(u64)]
+enum FromBytes6 {
+    A,
+}
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(i64)]
+enum FromBytes7 {
+    A,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+enum Unaligned1 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u16)]
+enum Unaligned2 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i16)]
+enum Unaligned3 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u32)]
+enum Unaligned4 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i32)]
+enum Unaligned5 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u64)]
+enum Unaligned6 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i64)]
+enum Unaligned7 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(usize)]
+enum Unaligned8 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(isize)]
+enum Unaligned9 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(u8, align(2))]
+enum Unaligned10 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(i8, align(2))]
+enum Unaligned11 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+enum Unaligned12 {
+    A,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+enum Unaligned13 {
+    A,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/enum.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/enum.stderr
new file mode 100644
index 0000000000..a47ce9c4ba
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/enum.stderr
@@ -0,0 +1,201 @@
+error: unrecognized representation hint
+  --> tests/ui-stable/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error: unrecognized representation hint
+  --> tests/ui-stable/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+
+error: unsupported representation for deriving FromBytes, AsBytes, or Unaligned on an enum
+  --> tests/ui-stable/enum.rs:31:8
+   |
+31 | #[repr(transparent)]
+   |        ^^^^^^^^^^^
+
+error: conflicting representation hints
+  --> tests/ui-stable/enum.rs:37:1
+   |
+37 | #[repr(u8, u16)]
+   | ^
+
+error: must have a non-align #[repr(...)] attribute in order to guarantee this type's memory layout
+  --> tests/ui-stable/enum.rs:42:22
+   |
+42 | #[derive(FromZeroes, FromBytes)]
+   |                      ^^^^^^^^^
+   |
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-stable/enum.rs:52:1
+   |
+52 | / enum FromZeroes1 {
+53 | |     A(u8),
+54 | | }
+   | |_^
+
+error: only C-like enums can implement FromZeroes
+  --> tests/ui-stable/enum.rs:57:1
+   |
+57 | / enum FromZeroes2 {
+58 | |     A,
+59 | |     B(u8),
+60 | | }
+   | |_^
+
+error: FromZeroes only supported on enums with a variant that has a discriminant of `0`
+  --> tests/ui-stable/enum.rs:63:1
+   |
+63 | / enum FromZeroes3 {
+64 | |     A = 1,
+65 | |     B,
+66 | | }
+   | |_^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-stable/enum.rs:73:8
+   |
+73 | #[repr(C)]
+   |        ^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-stable/enum.rs:79:8
+   |
+79 | #[repr(usize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-stable/enum.rs:85:8
+   |
+85 | #[repr(isize)]
+   |        ^^^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-stable/enum.rs:91:8
+   |
+91 | #[repr(u32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+  --> tests/ui-stable/enum.rs:97:8
+   |
+97 | #[repr(i32)]
+   |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-stable/enum.rs:103:8
+    |
+103 | #[repr(u64)]
+    |        ^^^
+
+error: FromBytes requires repr of "u8", "u16", "i8", or "i16"
+   --> tests/ui-stable/enum.rs:109:8
+    |
+109 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:119:8
+    |
+119 | #[repr(C)]
+    |        ^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:125:8
+    |
+125 | #[repr(u16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:131:8
+    |
+131 | #[repr(i16)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:137:8
+    |
+137 | #[repr(u32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:143:8
+    |
+143 | #[repr(i32)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:149:8
+    |
+149 | #[repr(u64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:155:8
+    |
+155 | #[repr(i64)]
+    |        ^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:161:8
+    |
+161 | #[repr(usize)]
+    |        ^^^^^
+
+error: Unaligned requires repr of "u8" or "i8", and no alignment (i.e., repr(align(N > 1)))
+   --> tests/ui-stable/enum.rs:167:8
+    |
+167 | #[repr(isize)]
+    |        ^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-stable/enum.rs:173:12
+    |
+173 | #[repr(u8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-stable/enum.rs:179:12
+    |
+179 | #[repr(i8, align(2))]
+    |            ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-stable/enum.rs:185:18
+    |
+185 | #[repr(align(1), align(2))]
+    |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+   --> tests/ui-stable/enum.rs:191:8
+    |
+191 | #[repr(align(2), align(4))]
+    |        ^^^^^^^^
+
+error[E0565]: meta item in `repr` must be an identifier
+  --> tests/ui-stable/enum.rs:19:8
+   |
+19 | #[repr("foo")]
+   |        ^^^^^
+
+error[E0552]: unrecognized representation hint
+  --> tests/ui-stable/enum.rs:25:8
+   |
+25 | #[repr(foo)]
+   |        ^^^
+   |
+   = help: valid reprs are `Rust` (default), `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`
+
+error[E0566]: conflicting representation hints
+  --> tests/ui-stable/enum.rs:37:8
+   |
+37 | #[repr(u8, u16)]
+   |        ^^  ^^^
+   |
+   = 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 #68585 <https://github.com/rust-lang/rust/issues/68585>
+   = note: `#[deny(conflicting_repr_hints)]` on by default
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.rs
new file mode 100644
index 0000000000..1b1bed31f3
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.rs
@@ -0,0 +1,272 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+fn main() {}
+
+#[derive(FromBytes)]
+#[repr(u8)]
+enum Foo {
+    Variant0,
+    Variant1,
+    Variant2,
+    Variant3,
+    Variant4,
+    Variant5,
+    Variant6,
+    Variant7,
+    Variant8,
+    Variant9,
+    Variant10,
+    Variant11,
+    Variant12,
+    Variant13,
+    Variant14,
+    Variant15,
+    Variant16,
+    Variant17,
+    Variant18,
+    Variant19,
+    Variant20,
+    Variant21,
+    Variant22,
+    Variant23,
+    Variant24,
+    Variant25,
+    Variant26,
+    Variant27,
+    Variant28,
+    Variant29,
+    Variant30,
+    Variant31,
+    Variant32,
+    Variant33,
+    Variant34,
+    Variant35,
+    Variant36,
+    Variant37,
+    Variant38,
+    Variant39,
+    Variant40,
+    Variant41,
+    Variant42,
+    Variant43,
+    Variant44,
+    Variant45,
+    Variant46,
+    Variant47,
+    Variant48,
+    Variant49,
+    Variant50,
+    Variant51,
+    Variant52,
+    Variant53,
+    Variant54,
+    Variant55,
+    Variant56,
+    Variant57,
+    Variant58,
+    Variant59,
+    Variant60,
+    Variant61,
+    Variant62,
+    Variant63,
+    Variant64,
+    Variant65,
+    Variant66,
+    Variant67,
+    Variant68,
+    Variant69,
+    Variant70,
+    Variant71,
+    Variant72,
+    Variant73,
+    Variant74,
+    Variant75,
+    Variant76,
+    Variant77,
+    Variant78,
+    Variant79,
+    Variant80,
+    Variant81,
+    Variant82,
+    Variant83,
+    Variant84,
+    Variant85,
+    Variant86,
+    Variant87,
+    Variant88,
+    Variant89,
+    Variant90,
+    Variant91,
+    Variant92,
+    Variant93,
+    Variant94,
+    Variant95,
+    Variant96,
+    Variant97,
+    Variant98,
+    Variant99,
+    Variant100,
+    Variant101,
+    Variant102,
+    Variant103,
+    Variant104,
+    Variant105,
+    Variant106,
+    Variant107,
+    Variant108,
+    Variant109,
+    Variant110,
+    Variant111,
+    Variant112,
+    Variant113,
+    Variant114,
+    Variant115,
+    Variant116,
+    Variant117,
+    Variant118,
+    Variant119,
+    Variant120,
+    Variant121,
+    Variant122,
+    Variant123,
+    Variant124,
+    Variant125,
+    Variant126,
+    Variant127,
+    Variant128,
+    Variant129,
+    Variant130,
+    Variant131,
+    Variant132,
+    Variant133,
+    Variant134,
+    Variant135,
+    Variant136,
+    Variant137,
+    Variant138,
+    Variant139,
+    Variant140,
+    Variant141,
+    Variant142,
+    Variant143,
+    Variant144,
+    Variant145,
+    Variant146,
+    Variant147,
+    Variant148,
+    Variant149,
+    Variant150,
+    Variant151,
+    Variant152,
+    Variant153,
+    Variant154,
+    Variant155,
+    Variant156,
+    Variant157,
+    Variant158,
+    Variant159,
+    Variant160,
+    Variant161,
+    Variant162,
+    Variant163,
+    Variant164,
+    Variant165,
+    Variant166,
+    Variant167,
+    Variant168,
+    Variant169,
+    Variant170,
+    Variant171,
+    Variant172,
+    Variant173,
+    Variant174,
+    Variant175,
+    Variant176,
+    Variant177,
+    Variant178,
+    Variant179,
+    Variant180,
+    Variant181,
+    Variant182,
+    Variant183,
+    Variant184,
+    Variant185,
+    Variant186,
+    Variant187,
+    Variant188,
+    Variant189,
+    Variant190,
+    Variant191,
+    Variant192,
+    Variant193,
+    Variant194,
+    Variant195,
+    Variant196,
+    Variant197,
+    Variant198,
+    Variant199,
+    Variant200,
+    Variant201,
+    Variant202,
+    Variant203,
+    Variant204,
+    Variant205,
+    Variant206,
+    Variant207,
+    Variant208,
+    Variant209,
+    Variant210,
+    Variant211,
+    Variant212,
+    Variant213,
+    Variant214,
+    Variant215,
+    Variant216,
+    Variant217,
+    Variant218,
+    Variant219,
+    Variant220,
+    Variant221,
+    Variant222,
+    Variant223,
+    Variant224,
+    Variant225,
+    Variant226,
+    Variant227,
+    Variant228,
+    Variant229,
+    Variant230,
+    Variant231,
+    Variant232,
+    Variant233,
+    Variant234,
+    Variant235,
+    Variant236,
+    Variant237,
+    Variant238,
+    Variant239,
+    Variant240,
+    Variant241,
+    Variant242,
+    Variant243,
+    Variant244,
+    Variant245,
+    Variant246,
+    Variant247,
+    Variant248,
+    Variant249,
+    Variant250,
+    Variant251,
+    Variant252,
+    Variant253,
+    Variant254,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.stderr
new file mode 100644
index 0000000000..5edbabc47d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/enum_from_bytes_u8_too_few.stderr
@@ -0,0 +1,11 @@
+error: FromBytes only supported on repr(u8) enum with 256 variants
+   --> tests/ui-stable/enum_from_bytes_u8_too_few.rs:15:1
+    |
+15  | / #[repr(u8)]
+16  | | enum Foo {
+17  | |     Variant0,
+18  | |     Variant1,
+...   |
+271 | |     Variant254,
+272 | | }
+    | |_^
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.rs
new file mode 100644
index 0000000000..cd65a6ed2c
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.rs
@@ -0,0 +1,75 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::{NotZerocopy, AU16};
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// FromZeroes errors
+//
+
+#[derive(FromZeroes)]
+struct FromZeroes1 {
+    value: NotZerocopy,
+}
+
+//
+// FromBytes errors
+//
+
+#[derive(FromBytes)]
+struct FromBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1 {
+    value: NotZerocopy,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned1 {
+    aligned: AU16,
+}
+
+// This specifically tests a bug we had in an old version of the code in which
+// the trait bound would only be enforced for the first field's type.
+#[derive(Unaligned)]
+#[repr(C)]
+struct Unaligned2 {
+    unaligned: u8,
+    aligned: AU16,
+}
+
+#[derive(Unaligned)]
+#[repr(transparent)]
+struct Unaligned3 {
+    aligned: AU16,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.stderr
new file mode 100644
index 0000000000..808054ab4d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/late_compile_pass.stderr
@@ -0,0 +1,144 @@
+warning: unused import: `zerocopy::KnownLayout`
+  --> tests/ui-stable/late_compile_pass.rs:16:5
+   |
+16 | use zerocopy::KnownLayout;
+   |     ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unused_imports)]` on by default
+
+error[E0277]: the trait bound `NotZerocopy: FromZeroes` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:28:10
+   |
+28 | #[derive(FromZeroes)]
+   |          ^^^^^^^^^^ the trait `FromZeroes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `FromZeroes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: FromBytes` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `FromBytes`:
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+             usize
+             u8
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `FromBytes1: FromZeroes` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:37:10
+   |
+37 | #[derive(FromBytes)]
+   |          ^^^^^^^^^ the trait `FromZeroes` is not implemented for `FromBytes1`
+   |
+   = help: the following other types implement trait `FromZeroes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+note: required by a bound in `FromBytes`
+  --> $WORKSPACE/src/lib.rs
+   |
+   | pub unsafe trait FromBytes: FromZeroes {
+   |                             ^^^^^^^^^^ required by this bound in `FromBytes`
+   = note: this error originates in the derive macro `FromBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotZerocopy: AsBytes` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:46:10
+   |
+46 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `AsBytes` is not implemented for `NotZerocopy`
+   |
+   = help: the following other types implement trait `AsBytes`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:56:10
+   |
+56 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:64:10
+   |
+64 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `AU16: Unaligned` is not satisfied
+  --> tests/ui-stable/late_compile_pass.rs:71:10
+   |
+71 | #[derive(Unaligned)]
+   |          ^^^^^^^^^ the trait `Unaligned` is not implemented for `AU16`
+   |
+   = help: the following other types implement trait `Unaligned`:
+             bool
+             i8
+             u8
+             Unaligned1
+             Unaligned2
+             Unaligned3
+             U16<O>
+             U32<O>
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `Unaligned` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.rs
new file mode 100644
index 0000000000..e0c4bc578d
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.rs
@@ -0,0 +1,61 @@
+// Copyright 2023 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+extern crate zerocopy;
+
+use zerocopy::KnownLayout;
+
+fn main() {}
+
+// These tests cause errors which are generated by a later compilation pass than
+// the other errors we generate, and so if they're compiled in the same file,
+// the compiler will never get to that pass, and so we won't get the errors.
+
+//
+// KnownLayout errors
+//
+
+fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              N |        N |      KL04 |
+#[derive(KnownLayout)]
+struct KL04<T: ?Sized>(u8, T);
+
+fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        Y |              Y |        N |      KL06 |
+#[derive(KnownLayout)]
+struct KL06<T: ?Sized + KnownLayout>(u8, T);
+
+fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+    assert_kl(kl);
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        N |      KL12 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL12<T: ?Sized>(u8, T);
+
+fn test_kl12<T: ?Sized>(kl: &KL12<T>) {
+    assert_kl(kl)
+}
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        Y |              N |        Y |      KL13 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL13<T>(u8, T);
+
+fn test_kl13<T>(t: T) -> impl KnownLayout {
+    KL13(0u8, t)
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.stderr
new file mode 100644
index 0000000000..f39bcdb170
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/mid_compile_pass.stderr
@@ -0,0 +1,104 @@
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-stable/mid_compile_pass.rs:59:26
+   |
+59 | fn test_kl13<T>(t: T) -> impl KnownLayout {
+   |                          ^^^^^^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `T`
+   |
+note: required for `KL13<T>` to implement `KnownLayout`
+  --> tests/ui-stable/mid_compile_pass.rs:55:10
+   |
+55 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider restricting type parameter `T`
+   |
+59 | fn test_kl13<T: zerocopy::KnownLayout>(t: T) -> impl KnownLayout {
+   |               +++++++++++++++++++++++
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-stable/mid_compile_pass.rs:31:15
+   |
+30 | fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+   |              - this type parameter needs to be `Sized`
+31 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL04<T>`
+  --> tests/ui-stable/mid_compile_pass.rs:28:8
+   |
+28 | struct KL04<T: ?Sized>(u8, T);
+   |        ^^^^
+note: required for `KL04<T>` to implement `KnownLayout`
+  --> tests/ui-stable/mid_compile_pass.rs:27:10
+   |
+27 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-stable/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+30 - fn test_kl04<T: ?Sized>(kl: &KL04<T>) {
+30 + fn test_kl04<T>(kl: &KL04<T>) {
+   |
+
+error[E0277]: the size for values of type `T` cannot be known at compilation time
+  --> tests/ui-stable/mid_compile_pass.rs:40:15
+   |
+39 | fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+   |              - this type parameter needs to be `Sized`
+40 |     assert_kl(kl);
+   |     --------- ^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required because it appears within the type `KL06<T>`
+  --> tests/ui-stable/mid_compile_pass.rs:37:8
+   |
+37 | struct KL06<T: ?Sized + KnownLayout>(u8, T);
+   |        ^^^^
+note: required for `KL06<T>` to implement `KnownLayout`
+  --> tests/ui-stable/mid_compile_pass.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-stable/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+39 - fn test_kl06<T: ?Sized + KnownLayout>(kl: &KL06<T>) {
+39 + fn test_kl06<T: KnownLayout>(kl: &KL06<T>) {
+   |
+
+error[E0277]: the trait bound `T: KnownLayout` is not satisfied
+  --> tests/ui-stable/mid_compile_pass.rs:50:15
+   |
+50 |     assert_kl(kl)
+   |     --------- ^^ the trait `KnownLayout` is not implemented for `T`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required for `KL12<T>` to implement `KnownLayout`
+  --> tests/ui-stable/mid_compile_pass.rs:45:10
+   |
+45 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
+note: required by a bound in `assert_kl`
+  --> tests/ui-stable/mid_compile_pass.rs:23:26
+   |
+23 | fn assert_kl<T: ?Sized + KnownLayout>(_: &T) {}
+   |                          ^^^^^^^^^^^ required by this bound in `assert_kl`
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider further restricting this bound
+   |
+49 | fn test_kl12<T: ?Sized + zerocopy::KnownLayout>(kl: &KL12<T>) {
+   |                        +++++++++++++++++++++++
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/struct.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/struct.rs
new file mode 100644
index 0000000000..c76dc7f952
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/struct.rs
@@ -0,0 +1,99 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use zerocopy::KnownLayout;
+
+use self::util::AU16;
+
+fn main() {}
+
+//
+// KnownLayout errors
+//
+
+struct NotKnownLayout;
+
+struct NotKnownLayoutDst([u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              N |        N |      KL00 |
+#[derive(KnownLayout)]
+struct KL00(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          N |        N |              Y |        N |      KL02 |
+#[derive(KnownLayout)]
+struct KL02(u8, [u8]);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        N |      KL08 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL08(u8, NotKnownLayoutDst);
+
+// | `repr(C)`? | generic? | `KnownLayout`? | `Sized`? | Type Name |
+// |          Y |        N |              N |        Y |      KL09 |
+#[derive(KnownLayout)]
+#[repr(C)]
+struct KL09(NotKnownLayout, NotKnownLayout);
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes1<T>(T);
+
+#[derive(AsBytes)]
+#[repr(C)]
+struct AsBytes2 {
+    foo: u8,
+    bar: AU16,
+}
+
+#[derive(AsBytes)]
+#[repr(C, packed(2))]
+struct AsBytes3 {
+    foo: u8,
+    // We'd prefer to use AU64 here, but you can't use aligned types in
+    // packed structs.
+    bar: u64,
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+struct Unaligned1;
+
+#[derive(Unaligned)]
+#[repr(transparent, align(2))]
+struct Unaligned2 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+struct Unaligned3;
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4;
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5;
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/struct.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/struct.stderr
new file mode 100644
index 0000000000..a93d7c45b0
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/struct.stderr
@@ -0,0 +1,131 @@
+error: unsupported on generic structs that are not repr(transparent) or repr(packed)
+  --> tests/ui-stable/struct.rs:55:10
+   |
+55 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/struct.rs:80:11
+   |
+80 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/struct.rs:84:21
+   |
+84 | #[repr(transparent, align(2))]
+   |                     ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/struct.rs:90:16
+   |
+90 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/struct.rs:94:18
+   |
+94 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/struct.rs:98:8
+   |
+98 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0692]: transparent struct cannot have other repr hints
+  --> tests/ui-stable/struct.rs:84:8
+   |
+84 | #[repr(transparent, align(2))]
+   |        ^^^^^^^^^^^  ^^^^^^^^
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-stable/struct.rs:31:10
+   |
+31 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL00`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL00`
+  --> tests/ui-stable/struct.rs:32:8
+   |
+32 | struct KL00(u8, NotKnownLayoutDst);
+   |        ^^^^
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> tests/ui-stable/struct.rs:36:10
+   |
+36 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: within `KL02`, the trait `Sized` is not implemented for `[u8]`
+note: required because it appears within the type `KL02`
+  --> tests/ui-stable/struct.rs:37:8
+   |
+37 | struct KL02(u8, [u8]);
+   |        ^^^^
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayoutDst: KnownLayout` is not satisfied
+  --> tests/ui-stable/struct.rs:41:10
+   |
+41 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayoutDst`
+   |
+   = help: the following other types implement trait `KnownLayout`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NotKnownLayout: KnownLayout` is not satisfied
+  --> tests/ui-stable/struct.rs:47:10
+   |
+47 | #[derive(KnownLayout)]
+   |          ^^^^^^^^^^^ the trait `KnownLayout` is not implemented for `NotKnownLayout`
+   |
+   = help: the following other types implement trait `KnownLayout`:
+             bool
+             char
+             isize
+             i8
+             i16
+             i32
+             i64
+             i128
+           and $N others
+   = help: see issue #48214
+   = note: this error originates in the derive macro `KnownLayout` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-stable/struct.rs:59:10
+   |
+59 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the trait `ShouldBe<VALUE>` is implemented for `HasPadding<T, VALUE>`
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `HasPadding<AsBytes3, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-stable/struct.rs:66:10
+   |
+66 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes3, true>`
+   |
+   = help: the trait `ShouldBe<VALUE>` is implemented for `HasPadding<T, VALUE>`
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/union.rs b/third_party/rust/zerocopy-derive/tests/ui-stable/union.rs
new file mode 100644
index 0000000000..8938e78478
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/union.rs
@@ -0,0 +1,73 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#[macro_use]
+extern crate zerocopy;
+
+#[path = "../util.rs"]
+mod util;
+
+use self::util::AU16;
+use std::mem::ManuallyDrop;
+
+fn main() {}
+
+//
+// AsBytes errors
+//
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes1<T> {
+    foo: ManuallyDrop<T>,
+}
+
+#[derive(AsBytes)]
+#[repr(C)]
+union AsBytes2 {
+    foo: u8,
+    bar: [u8; 2],
+}
+
+//
+// Unaligned errors
+//
+
+#[derive(Unaligned)]
+#[repr(C, align(2))]
+union Unaligned1 {
+    foo: i16,
+    bar: AU16,
+}
+
+// Transparent unions are unstable; see issue #60405
+// <https://github.com/rust-lang/rust/issues/60405> for more information.
+
+// #[derive(Unaligned)]
+// #[repr(transparent, align(2))]
+// union Unaligned2 {
+//     foo: u8,
+// }
+
+#[derive(Unaligned)]
+#[repr(packed, align(2))]
+union Unaligned3 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(1), align(2))]
+struct Unaligned4 {
+    foo: u8,
+}
+
+#[derive(Unaligned)]
+#[repr(align(2), align(4))]
+struct Unaligned5 {
+    foo: u8,
+}
diff --git a/third_party/rust/zerocopy-derive/tests/ui-stable/union.stderr b/third_party/rust/zerocopy-derive/tests/ui-stable/union.stderr
new file mode 100644
index 0000000000..8d5cbbbd66
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/ui-stable/union.stderr
@@ -0,0 +1,41 @@
+error: unsupported on types with type parameters
+  --> tests/ui-stable/union.rs:24:10
+   |
+24 | #[derive(AsBytes)]
+   |          ^^^^^^^
+   |
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/union.rs:42:11
+   |
+42 | #[repr(C, align(2))]
+   |           ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/union.rs:58:16
+   |
+58 | #[repr(packed, align(2))]
+   |                ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/union.rs:64:18
+   |
+64 | #[repr(align(1), align(2))]
+   |                  ^^^^^^^^
+
+error: cannot derive Unaligned with repr(align(N > 1))
+  --> tests/ui-stable/union.rs:70:8
+   |
+70 | #[repr(align(2), align(4))]
+   |        ^^^^^^^^
+
+error[E0277]: the trait bound `HasPadding<AsBytes2, true>: ShouldBe<false>` is not satisfied
+  --> tests/ui-stable/union.rs:30:10
+   |
+30 | #[derive(AsBytes)]
+   |          ^^^^^^^ the trait `ShouldBe<false>` is not implemented for `HasPadding<AsBytes2, true>`
+   |
+   = help: the trait `ShouldBe<VALUE>` is implemented for `HasPadding<T, VALUE>`
+   = help: see issue #48214
+   = note: this error originates in the derive macro `AsBytes` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/third_party/rust/zerocopy-derive/tests/union_as_bytes.rs b/third_party/rust/zerocopy-derive/tests/union_as_bytes.rs
new file mode 100644
index 0000000000..84f51817f2
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/union_as_bytes.rs
@@ -0,0 +1,75 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::AsBytes};
+
+// A union is `AsBytes` if:
+// - all fields are `AsBytes`
+// - `repr(C)` or `repr(transparent)` and
+//   - no padding (size of union equals size of each field type)
+// - `repr(packed)`
+
+#[derive(AsBytes, Clone, Copy)]
+#[repr(C)]
+union CZst {
+    a: (),
+}
+
+assert_impl_all!(CZst: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C)]
+union C {
+    a: u8,
+    b: u8,
+}
+
+assert_impl_all!(C: AsBytes);
+
+// Transparent unions are unstable; see issue #60405
+// <https://github.com/rust-lang/rust/issues/60405> for more information.
+
+// #[derive(AsBytes)]
+// #[repr(transparent)]
+// union Transparent {
+//     a: u8,
+//     b: CZst,
+// }
+
+// is_as_bytes!(Transparent);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+union CZstPacked {
+    a: (),
+}
+
+assert_impl_all!(CZstPacked: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+union CPacked {
+    a: u8,
+    b: i8,
+}
+
+assert_impl_all!(CPacked: AsBytes);
+
+#[derive(AsBytes)]
+#[repr(C, packed)]
+union CMultibytePacked {
+    a: i32,
+    b: u32,
+    c: f32,
+}
+
+assert_impl_all!(CMultibytePacked: AsBytes);
diff --git a/third_party/rust/zerocopy-derive/tests/union_from_bytes.rs b/third_party/rust/zerocopy-derive/tests/union_from_bytes.rs
new file mode 100644
index 0000000000..4635735ef1
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/union_from_bytes.rs
@@ -0,0 +1,72 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {
+    static_assertions::assert_impl_all,
+    zerocopy::{FromBytes, FromZeroes},
+};
+
+// A union is `FromBytes` if:
+// - all fields are `FromBytes`
+
+#[derive(Clone, Copy, FromZeroes, FromBytes)]
+union Zst {
+    a: (),
+}
+
+assert_impl_all!(Zst: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+union One {
+    a: u8,
+}
+
+assert_impl_all!(One: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+union Two {
+    a: u8,
+    b: Zst,
+}
+
+assert_impl_all!(Two: FromBytes);
+
+#[derive(FromZeroes, FromBytes)]
+union TypeParams<'a, T: Copy, I: Iterator>
+where
+    I::Item: Copy,
+{
+    a: T,
+    c: I::Item,
+    d: u8,
+    e: PhantomData<&'a [u8]>,
+    f: PhantomData<&'static str>,
+    g: PhantomData<String>,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: FromBytes);
+
+// Deriving `FromBytes` should work if the union has bounded parameters.
+
+#[derive(FromZeroes, FromBytes)]
+#[repr(C)]
+union WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + FromBytes>
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + Copy + FromBytes,
+{
+    a: [T; N],
+    b: PhantomData<&'a &'b ()>,
+}
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: FromBytes);
diff --git a/third_party/rust/zerocopy-derive/tests/union_from_zeroes.rs b/third_party/rust/zerocopy-derive/tests/union_from_zeroes.rs
new file mode 100644
index 0000000000..935fc1563b
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/union_from_zeroes.rs
@@ -0,0 +1,72 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+#[macro_use]
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::FromZeroes};
+
+// A union is `FromZeroes` if:
+// - all fields are `FromZeroes`
+
+#[derive(Clone, Copy, FromZeroes)]
+union Zst {
+    a: (),
+}
+
+assert_impl_all!(Zst: FromZeroes);
+
+#[derive(FromZeroes)]
+union One {
+    a: bool,
+}
+
+assert_impl_all!(One: FromZeroes);
+
+#[derive(FromZeroes)]
+union Two {
+    a: bool,
+    b: Zst,
+}
+
+assert_impl_all!(Two: FromZeroes);
+
+#[derive(FromZeroes)]
+union TypeParams<'a, T: Copy, I: Iterator>
+where
+    I::Item: Copy,
+{
+    a: T,
+    c: I::Item,
+    d: u8,
+    e: PhantomData<&'a [u8]>,
+    f: PhantomData<&'static str>,
+    g: PhantomData<String>,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: FromZeroes);
+
+// Deriving `FromZeroes` should work if the union has bounded parameters.
+
+#[derive(FromZeroes)]
+#[repr(C)]
+union WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + FromZeroes>
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + Copy + FromZeroes,
+{
+    a: [T; N],
+    b: PhantomData<&'a &'b ()>,
+}
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: FromZeroes);
diff --git a/third_party/rust/zerocopy-derive/tests/union_known_layout.rs b/third_party/rust/zerocopy-derive/tests/union_known_layout.rs
new file mode 100644
index 0000000000..337ab4afef
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/union_known_layout.rs
@@ -0,0 +1,65 @@
+// Copyright 2022 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![allow(warnings)]
+
+#[macro_use]
+mod util;
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::KnownLayout};
+
+#[derive(Clone, Copy, KnownLayout)]
+union Zst {
+    a: (),
+}
+
+assert_impl_all!(Zst: KnownLayout);
+
+#[derive(KnownLayout)]
+union One {
+    a: bool,
+}
+
+assert_impl_all!(One: KnownLayout);
+
+#[derive(KnownLayout)]
+union Two {
+    a: bool,
+    b: Zst,
+}
+
+assert_impl_all!(Two: KnownLayout);
+
+#[derive(KnownLayout)]
+union TypeParams<'a, T: Copy, I: Iterator>
+where
+    I::Item: Copy,
+{
+    a: T,
+    c: I::Item,
+    d: u8,
+    e: PhantomData<&'a [u8]>,
+    f: PhantomData<&'static str>,
+    g: PhantomData<String>,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: KnownLayout);
+
+// Deriving `KnownLayout` should work if the union has bounded parameters.
+
+#[derive(KnownLayout)]
+#[repr(C)]
+union WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + KnownLayout>
+where
+    'a: 'b,
+    'b: 'a,
+    T: 'a + 'b + Copy + KnownLayout,
+{
+    a: [T; N],
+    b: PhantomData<&'a &'b ()>,
+}
+
+assert_impl_all!(WithParams<'static, 'static, 42, u8>: KnownLayout);
diff --git a/third_party/rust/zerocopy-derive/tests/union_unaligned.rs b/third_party/rust/zerocopy-derive/tests/union_unaligned.rs
new file mode 100644
index 0000000000..5ba3ac76ac
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/union_unaligned.rs
@@ -0,0 +1,77 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+#![allow(warnings)]
+
+use std::{marker::PhantomData, option::IntoIter};
+
+use {static_assertions::assert_impl_all, zerocopy::Unaligned};
+
+// A union is `Unaligned` if:
+// - `repr(align)` is no more than 1 and either
+//   - `repr(C)` or `repr(transparent)` and
+//     - all fields `Unaligned`
+//   - `repr(packed)`
+
+#[derive(Unaligned)]
+#[repr(C)]
+union Foo {
+    a: u8,
+}
+
+assert_impl_all!(Foo: Unaligned);
+
+// Transparent unions are unstable; see issue #60405
+// <https://github.com/rust-lang/rust/issues/60405> for more information.
+
+// #[derive(Unaligned)]
+// #[repr(transparent)]
+// union Bar {
+//     a: u8,
+// }
+
+// is_unaligned!(Bar);
+
+#[derive(Unaligned)]
+#[repr(packed)]
+union Baz {
+    // NOTE: The `u16` type is not guaranteed to have alignment 2, although it
+    // does on many platforms. However, to fix this would require a custom type
+    // with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not
+    // allowed to transitively contain `#[repr(align(...))]` types. Thus, we
+    // have no choice but to use `u16` here. Luckily, these tests run in CI on
+    // platforms on which `u16` has alignment 2, so this isn't that big of a
+    // deal.
+    a: u16,
+}
+
+assert_impl_all!(Baz: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(C, align(1))]
+union FooAlign {
+    a: u8,
+}
+
+assert_impl_all!(FooAlign: Unaligned);
+
+#[derive(Unaligned)]
+#[repr(C)]
+union TypeParams<'a, T: Copy, I: Iterator>
+where
+    I::Item: Copy,
+{
+    a: T,
+    c: I::Item,
+    d: u8,
+    e: PhantomData<&'a [u8]>,
+    f: PhantomData<&'static str>,
+    g: PhantomData<String>,
+}
+
+assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: Unaligned);
diff --git a/third_party/rust/zerocopy-derive/tests/util.rs b/third_party/rust/zerocopy-derive/tests/util.rs
new file mode 100644
index 0000000000..a8656fb20f
--- /dev/null
+++ b/third_party/rust/zerocopy-derive/tests/util.rs
@@ -0,0 +1,20 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+use zerocopy::{AsBytes, FromBytes, FromZeroes, KnownLayout};
+
+/// A type that doesn't implement any zerocopy traits.
+pub struct NotZerocopy<T = ()>(T);
+
+/// A `u16` with alignment 2.
+///
+/// Though `u16` has alignment 2 on some platforms, it's not guaranteed. By
+/// contrast, `AU16` is guaranteed to have alignment 2.
+#[derive(KnownLayout, FromZeroes, FromBytes, AsBytes, Copy, Clone)]
+#[repr(C, align(2))]
+pub struct AU16(u16);