Remove Opaque Ptr macro: define_opaque_nonnulls

We still retain RawMessage and RawArena, but drop the macro for readability.

In lieu of invoking define_opaque_nonnulls, we spell out RawMessage and RawArena by hand.

PiperOrigin-RevId: 559906043

rust/internal.rs

@@ -32,22 +32,54 @@
 //! exposed to through the `protobuf` path but must be public for use by
 //! generated code.
 
-use crate::macros::define_opaque_nonnulls;
 pub use crate::vtable::{
     new_vtable_field_entry, BytesMutVTable, BytesOptionalMutVTable, RawVTableMutator,
 };
+use std::ptr::NonNull;
 use std::slice;
 
 /// Used to protect internal-only items from being used accidentally.
 pub struct Private;
 
-define_opaque_nonnulls!(
-    /// A raw pointer to the underlying arena for this runtime.
-    pub type RawArena = NonNull<RawArenaData>;
+/// Defines a set of opaque, unique, non-accessible pointees.
+///
+/// The [Rustonomicon][nomicon] currently recommends a zero-sized struct,
+/// though this should use [`extern type`] when that is stabilized.
+/// [nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
+/// [`extern type`]: https://github.com/rust-lang/rust/issues/43467
+mod _opaque_pointees {
+    /// Opaque pointee for [`RawMessage`]
+    ///
+    /// This type is not meant to be dereferenced in Rust code.
+    /// It is only meant to provide type safety for raw pointers
+    /// which are manipulated behind FFI.
+    ///
+    /// [`RawMessage`]: super::RawMessage
+    #[repr(C)]
+    pub struct RawMessageData {
+        _data: [u8; 0],
+        _marker: std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
+    }
+
+    /// Opaque pointee for [`RawArena`]
+    ///
+    /// This type is not meant to be dereferenced in Rust code.
+    /// It is only meant to provide type safety for raw pointers
+    /// which are manipulated behind FFI.
+    ///
+    /// [`RawArena`]: super::RawArena
+    #[repr(C)]
+    pub struct RawArenaData {
+        _data: [u8; 0],
+        _marker: std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
+    }
+}
+
+/// A raw pointer to the underlying message for this runtime.
+pub type RawMessage = NonNull<_opaque_pointees::RawMessageData>;
 
-    /// A raw pointer to the underlying message for this runtime.
-    pub type RawMessage = NonNull<RawMessageData>;
-);
+/// A raw pointer to the underlying arena for this runtime.
+pub type RawArena = NonNull<_opaque_pointees::RawArenaData>;
 
 /// Represents an ABI-stable version of `NonNull<[u8]>`/`string_view` (a
 /// borrowed slice of bytes) for FFI use only.

rust/macros.rs

@@ -30,45 +30,6 @@
 
 //! Runtime-internal macros
 
-/// Defines a set of opaque pointers and a unique non-accessible pointees.
-///
-/// This provides a type safety benefit over using `NonNull<u8>` everywhere.
-/// The [Rustonomicon][nomicon] currently recommends a zero-sized struct,
-/// though this should use [`extern type`] when that is stabilized.
-///
-/// Because this defines a new private module, it can only be called once per
-/// module.
-///
-/// [nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
-/// [`extern type`]: https://github.com/rust-lang/rust/issues/43467
-macro_rules! define_opaque_nonnulls {
-    ($($(#[$meta:meta])* $vis:vis type $name:ident = NonNull<$raw_name:ident>;)*) => {
-        mod _opaque_pointees {
-            $(
-                #[doc = concat!("Opaque pointee for [`", stringify!($name), "`][pointer]")]
-                ///
-                /// This type is not meant to be dereferenced in Rust code.
-                /// It is only meant to provide type safety for raw pointers
-                /// which are manipulated behind FFI.
-                #[doc = concat!("[pointer]: super::", stringify!($name))]
-                #[repr(C)]
-                pub struct $raw_name {
-                    _data: [u8; 0],
-                    _marker: ::std::marker::PhantomData<(*mut u8, ::std::marker::PhantomPinned)>,
-                }
-            )*
-        }
-        $(
-            $(#[$meta])*
-            ///
-            /// This is an opaque pointer used for FFI:
-            /// do not dereference this type in Rust code.
-            $vis type $name = ::std::ptr::NonNull<_opaque_pointees::$raw_name>;
-        )*
-    };
-}
-pub(crate) use define_opaque_nonnulls;
-
 /// Defines a `impl SettableValue<$proxied> for SomeType` body that forwards to
 /// another implementation.
 ///