Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 262 insertions, 0 deletions

diff --git a/third_party/rust/bitflags/src/external.rs b/third_party/rust/bitflags/src/external.rs
new file mode 100644
index 0000000000..efeaa82796
--- /dev/null
+++ b/third_party/rust/bitflags/src/external.rs
@@ -0,0 +1,262 @@
+//! Conditional trait implementations for external libraries.
+
+/*
+How do I support a new external library?
+
+Let's say we want to add support for `my_library`.
+
+First, we create a module under `external`, like `serde` with any specialized code.
+Ideally, any utilities in here should just work off the `Flags` trait and maybe a
+few other assumed bounds.
+
+Next, re-export the library from the `__private` module here.
+
+Next, define a macro like so:
+
+```rust
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(feature = "serde")]
+macro_rules! __impl_external_bitflags_my_library {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {
+        // Implementation goes here
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(not(feature = "my_library"))]
+macro_rules! __impl_external_bitflags_my_library {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {};
+}
+```
+
+Note that the macro is actually defined twice; once for when the `my_library` feature
+is available, and once for when it's not. This is because the `__impl_external_bitflags_my_library`
+macro is called in an end-user's library, not in `bitflags`. In an end-user's library we don't
+know whether or not a particular feature of `bitflags` is enabled, so we unconditionally call
+the macro, where the body of that macro depends on the feature flag.
+
+Now, we add our macro call to the `__impl_external_bitflags` macro body:
+
+```rust
+__impl_external_bitflags_my_library! {
+    $InternalBitFlags: $T, $PublicBitFlags {
+        $(
+            $(#[$inner $($args)*])*
+            const $Flag;
+        )*
+    }
+}
+```
+*/
+
+pub(crate) mod __private {
+    #[cfg(feature = "serde")]
+    pub use serde;
+
+    #[cfg(feature = "arbitrary")]
+    pub use arbitrary;
+
+    #[cfg(feature = "bytemuck")]
+    pub use bytemuck;
+}
+
+/// Implements traits from external libraries for the internal bitflags type.
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+macro_rules! __impl_external_bitflags {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {
+        // Any new library traits impls should be added here
+        // Use `serde` as an example: generate code when the feature is available,
+        // and a no-op when it isn't
+
+        __impl_external_bitflags_serde! {
+            $InternalBitFlags: $T, $PublicBitFlags {
+                $(
+                    $(#[$inner $($args)*])*
+                    const $Flag;
+                )*
+            }
+        }
+
+        __impl_external_bitflags_arbitrary! {
+            $InternalBitFlags: $T, $PublicBitFlags {
+                $(
+                    $(#[$inner $($args)*])*
+                    const $Flag;
+                )*
+            }
+        }
+
+        __impl_external_bitflags_bytemuck! {
+            $InternalBitFlags: $T, $PublicBitFlags {
+                $(
+                    $(#[$inner $($args)*])*
+                    const $Flag;
+                )*
+            }
+        }
+    };
+}
+
+#[cfg(feature = "serde")]
+pub mod serde;
+
+/// Implement `Serialize` and `Deserialize` for the internal bitflags type.
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(feature = "serde")]
+macro_rules! __impl_external_bitflags_serde {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {
+        impl $crate::__private::serde::Serialize for $InternalBitFlags {
+            fn serialize<S: $crate::__private::serde::Serializer>(
+                &self,
+                serializer: S,
+            ) -> $crate::__private::core::result::Result<S::Ok, S::Error> {
+                $crate::serde::serialize(
+                    &$PublicBitFlags::from_bits_retain(self.bits()),
+                    serializer,
+                )
+            }
+        }
+
+        impl<'de> $crate::__private::serde::Deserialize<'de> for $InternalBitFlags {
+            fn deserialize<D: $crate::__private::serde::Deserializer<'de>>(
+                deserializer: D,
+            ) -> $crate::__private::core::result::Result<Self, D::Error> {
+                let flags: $PublicBitFlags = $crate::serde::deserialize(deserializer)?;
+
+                Ok(flags.0)
+            }
+        }
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(not(feature = "serde"))]
+macro_rules! __impl_external_bitflags_serde {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {};
+}
+
+#[cfg(feature = "arbitrary")]
+pub mod arbitrary;
+
+#[cfg(feature = "bytemuck")]
+mod bytemuck;
+
+/// Implement `Arbitrary` for the internal bitflags type.
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(feature = "arbitrary")]
+macro_rules! __impl_external_bitflags_arbitrary {
+    (
+            $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+                $(
+                    $(#[$inner:ident $($args:tt)*])*
+                    const $Flag:tt;
+                )*
+            }
+    ) => {
+        impl<'a> $crate::__private::arbitrary::Arbitrary<'a> for $InternalBitFlags {
+            fn arbitrary(
+                u: &mut $crate::__private::arbitrary::Unstructured<'a>,
+            ) -> $crate::__private::arbitrary::Result<Self> {
+                $crate::arbitrary::arbitrary::<$PublicBitFlags>(u).map(|flags| flags.0)
+            }
+        }
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(not(feature = "arbitrary"))]
+macro_rules! __impl_external_bitflags_arbitrary {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {};
+}
+
+/// Implement `Pod` and `Zeroable` for the internal bitflags type.
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(feature = "bytemuck")]
+macro_rules! __impl_external_bitflags_bytemuck {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {
+        // SAFETY: $InternalBitFlags is guaranteed to have the same ABI as $T,
+        // and $T implements Pod
+        unsafe impl $crate::__private::bytemuck::Pod for $InternalBitFlags where
+            $T: $crate::__private::bytemuck::Pod
+        {
+        }
+
+        // SAFETY: $InternalBitFlags is guaranteed to have the same ABI as $T,
+        // and $T implements Zeroable
+        unsafe impl $crate::__private::bytemuck::Zeroable for $InternalBitFlags where
+            $T: $crate::__private::bytemuck::Zeroable
+        {
+        }
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+#[cfg(not(feature = "bytemuck"))]
+macro_rules! __impl_external_bitflags_bytemuck {
+    (
+        $InternalBitFlags:ident: $T:ty, $PublicBitFlags:ident {
+            $(
+                $(#[$inner:ident $($args:tt)*])*
+                const $Flag:tt;
+            )*
+        }
+    ) => {};
+}