compiler: Fully stabilize result_ffi_guarantees

Author: workingjubilee

compiler/rustc_feature/src/accepted.rs

@@ -353,6 +353,9 @@ declare_features! (
 (accepted, repr_packed,"1.33.0",Some(33158)),
 /// Allows `#[repr(transparent)]` attribute on newtype structs.
 (accepted, repr_transparent,"1.28.0",Some(43036)),
+/// Allows enums like Result<T, E> to be used across FFI, if T's niche value can
+/// be used to describe E or vice-versa.
+(accepted, result_ffi_guarantees,"1.80.0",Some(110503)),
 /// Allows return-position `impl Trait` in traits.
 (accepted, return_position_impl_trait_in_trait,"1.75.0",Some(91611)),
 /// Allows code like `let x: &'static u32 = &42` to work (RFC 1414).

compiler/rustc_feature/src/unstable.rs

@@ -580,9 +580,6 @@ declare_features! (
 (incomplete, repr128,"1.16.0",Some(56071)),
 /// Allows `repr(simd)` and importing the various simd intrinsics.
 (unstable, repr_simd,"1.4.0",Some(27731)),
-/// Allows enums like Result<T, E> to be used across FFI, if T's niche value can
-/// be used to describe E or vise-versa.
-(unstable, result_ffi_guarantees,"1.80.0",Some(110503)),
 /// Allows bounding the return type of AFIT/RPITIT.
 (unstable, return_type_notation,"1.70.0",Some(109417)),
 /// Allows `extern "rust-cold"`.

compiler/rustc_lint/src/types.rs

@@ -741,10 +741,6 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
 [var_one, var_two] => match(&var_one.fields.raw[..],&var_two.fields.raw[..]){
 ([],[field]) | ([field],[]) => field.ty(tcx, args),
 ([field1],[field2]) => {
-if !tcx.features().result_ffi_guarantees{
-returnNone;
-}
-
 let ty1 = field1.ty(tcx, args);
 let ty2 = field2.ty(tcx, args);
 

tests/ui/feature-gates/feature-gate-result_ffi_guarantees.stderr

@@ -2,7 +2,6 @@
 #![deny(improper_ctypes)]
 #![feature(ptr_internals)]
 #![feature(transparent_unions)]
-#![feature(result_ffi_guarantees)]
 
 use std::num;
 

tests/ui/lint/lint-ctypes-enum.rs

@@ -1,13 +1,13 @@
 error: `extern` block uses type `U`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:69:14
+ --> $DIR/lint-ctypes-enum.rs:68:14
  |
 LL | fn uf(x: U);
  | ^ not FFI-safe
  |
  = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
  = note: enum has no representation hint
 note: the type is defined here
- --> $DIR/lint-ctypes-enum.rs:10:1
+ --> $DIR/lint-ctypes-enum.rs:9:1
  |
 LL | enum U {
  | ^^^^^^
@@ -18,51 +18,51 @@ LL | #![deny(improper_ctypes)]
  | ^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `B`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:70:14
+ --> $DIR/lint-ctypes-enum.rs:69:14
  |
 LL | fn bf(x: B);
  | ^ not FFI-safe
  |
  = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
  = note: enum has no representation hint
 note: the type is defined here
- --> $DIR/lint-ctypes-enum.rs:13:1
+ --> $DIR/lint-ctypes-enum.rs:12:1
  |
 LL | enum B {
  | ^^^^^^
 
 error: `extern` block uses type `T`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:71:14
+ --> $DIR/lint-ctypes-enum.rs:70:14
  |
 LL | fn tf(x: T);
  | ^ not FFI-safe
  |
  = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
  = note: enum has no representation hint
 note: the type is defined here
- --> $DIR/lint-ctypes-enum.rs:17:1
+ --> $DIR/lint-ctypes-enum.rs:16:1
  |
 LL | enum T {
  | ^^^^^^
 
 error: `extern` block uses type `u128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:83:31
+ --> $DIR/lint-ctypes-enum.rs:82:31
  |
 LL | fn option_nonzero_u128(x: Option<num::NonZero<u128>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:90:31
+ --> $DIR/lint-ctypes-enum.rs:89:31
  |
 LL | fn option_nonzero_i128(x: Option<num::NonZero<i128>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Option<TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:95:36
+ --> $DIR/lint-ctypes-enum.rs:94:36
  |
 LL | fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -71,7 +71,7 @@ LL | fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>
  = note: enum has no representation hint
 
 error: `extern` block uses type `Option<Rust<NonZero<u8>>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:97:28
+ --> $DIR/lint-ctypes-enum.rs:96:28
  |
 LL | fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -80,23 +80,23 @@ LL | fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
  = note: enum has no representation hint
 
 error: `extern` block uses type `u128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:107:33
+ --> $DIR/lint-ctypes-enum.rs:106:33
  |
 LL | fn result_nonzero_u128_t(x: Result<num::NonZero<u128>, ()>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:114:33
+ --> $DIR/lint-ctypes-enum.rs:113:33
  |
 LL | fn result_nonzero_i128_t(x: Result<num::NonZero<i128>, ()>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Result<TransparentUnion<NonZero<u8>>, ()>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:119:38
+ --> $DIR/lint-ctypes-enum.rs:118:38
  |
 LL | fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u8>>, ()>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -105,7 +105,7 @@ LL | fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Rust<NonZero<u8>>, ()>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:121:30
+ --> $DIR/lint-ctypes-enum.rs:120:30
  |
 LL | fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -114,7 +114,7 @@ LL | fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, U>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:125:51
+ --> $DIR/lint-ctypes-enum.rs:124:51
  |
 LL | fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>, U>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -123,7 +123,7 @@ LL | fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>,
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, B>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:127:53
+ --> $DIR/lint-ctypes-enum.rs:126:53
  |
 LL | fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>, B>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -132,7 +132,7 @@ LL | fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, NonExhaustive>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:129:51
+ --> $DIR/lint-ctypes-enum.rs:128:51
  |
 LL | fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>, NonExhaustive>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -141,7 +141,7 @@ LL | fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>,
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, Field>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:132:49
+ --> $DIR/lint-ctypes-enum.rs:131:49
  |
 LL | fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Field>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -150,7 +150,7 @@ LL | fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Fi
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Result<(), NonZero<u8>>, ()>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:134:30
+ --> $DIR/lint-ctypes-enum.rs:133:30
  |
 LL | fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -159,23 +159,23 @@ LL | fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
  = note: enum has no representation hint
 
 error: `extern` block uses type `u128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:145:33
+ --> $DIR/lint-ctypes-enum.rs:144:33
  |
 LL | fn result_nonzero_u128_e(x: Result<(), num::NonZero<u128>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `i128`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:152:33
+ --> $DIR/lint-ctypes-enum.rs:151:33
  |
 LL | fn result_nonzero_i128_e(x: Result<(), num::NonZero<i128>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
  |
  = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Result<(), TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:157:38
+ --> $DIR/lint-ctypes-enum.rs:156:38
  |
 LL | fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZero<u8>>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -184,7 +184,7 @@ LL | fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZe
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Rust<NonZero<u8>>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:159:30
+ --> $DIR/lint-ctypes-enum.rs:158:30
  |
 LL | fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -193,7 +193,7 @@ LL | fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<U, NonZero<u8>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:163:51
+ --> $DIR/lint-ctypes-enum.rs:162:51
  |
 LL | fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -202,7 +202,7 @@ LL | fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<B, NonZero<u8>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:165:53
+ --> $DIR/lint-ctypes-enum.rs:164:53
  |
 LL | fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<u8>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -211,7 +211,7 @@ LL | fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonExhaustive, NonZero<u8>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:167:51
+ --> $DIR/lint-ctypes-enum.rs:166:51
  |
 LL | fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num::NonZero<u8>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -220,7 +220,7 @@ LL | fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Field, NonZero<u8>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:170:49
+ --> $DIR/lint-ctypes-enum.rs:169:49
  |
 LL | fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<u8>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -229,7 +229,7 @@ LL | fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Result<(), NonZero<u8>>>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:172:30
+ --> $DIR/lint-ctypes-enum.rs:171:30
  |
 LL | fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -238,7 +238,7 @@ LL | fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
  = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), ()>`, which is not FFI-safe
- --> $DIR/lint-ctypes-enum.rs:174:27
+ --> $DIR/lint-ctypes-enum.rs:173:27
  |
 LL | fn result_unit_t_e(x: Result<(), ()>);
  | ^^^^^^^^^^^^^^ not FFI-safe

tests/ui/lint/lint-ctypes-enum.stderr

@@ -1,3 +1,4 @@
+//@ build-pass
 #![allow(dead_code)]
 #![deny(improper_ctypes)]
 #![feature(ptr_internals)]
@@ -18,82 +19,44 @@ struct NoField;
 
 extern"C"{
 fnresult_ref_t(x:Result<&'staticu8,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_fn_t(x:Result<extern"C"fn(),()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonnull_t(x:Result<std::ptr::NonNull<u8>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_unique_t(x:Result<std::ptr::Unique<u8>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u8_t(x:Result<num::NonZero<u8>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u16_t(x:Result<num::NonZero<u16>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u32_t(x:Result<num::NonZero<u32>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u64_t(x:Result<num::NonZero<u64>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_usize_t(x:Result<num::NonZero<usize>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i8_t(x:Result<num::NonZero<i8>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i16_t(x:Result<num::NonZero<i16>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i32_t(x:Result<num::NonZero<i32>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i64_t(x:Result<num::NonZero<i64>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_isize_t(x:Result<num::NonZero<isize>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_transparent_struct_t(x:Result<TransparentStruct<num::NonZero<u8>>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_transparent_enum_t(x:Result<TransparentEnum<num::NonZero<u8>>,()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_phantom_t(x:Result<num::NonZero<u8>, std::marker::PhantomData<()>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_1zst_exhaustive_no_variant_t(x:Result<num::NonZero<u8>,Z>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_1zst_exhaustive_no_field_t(x:Result<num::NonZero<u8>,NoField>);
-//~^ ERROR `extern` block uses type `Result
 
 fnresult_ref_e(x:Result<(),&'staticu8>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_fn_e(x:Result<(),extern"C"fn()>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonnull_e(x:Result<(), std::ptr::NonNull<u8>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_unique_e(x:Result<(), std::ptr::Unique<u8>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u8_e(x:Result<(), num::NonZero<u8>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u16_e(x:Result<(), num::NonZero<u16>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u32_e(x:Result<(), num::NonZero<u32>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_u64_e(x:Result<(), num::NonZero<u64>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_usize_e(x:Result<(), num::NonZero<usize>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i8_e(x:Result<(), num::NonZero<i8>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i16_e(x:Result<(), num::NonZero<i16>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i32_e(x:Result<(), num::NonZero<i32>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_i64_e(x:Result<(), num::NonZero<i64>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_nonzero_isize_e(x:Result<(), num::NonZero<isize>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_transparent_struct_e(x:Result<(),TransparentStruct<num::NonZero<u8>>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_transparent_enum_e(x:Result<(),TransparentEnum<num::NonZero<u8>>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_phantom_e(x:Result<num::NonZero<u8>, std::marker::PhantomData<()>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_1zst_exhaustive_no_variant_e(x:Result<Z, num::NonZero<u8>>);
-//~^ ERROR `extern` block uses type `Result
 fnresult_1zst_exhaustive_no_field_e(x:Result<NoField, num::NonZero<u8>>);
-//~^ ERROR `extern` block uses type `Result
 }
 
 pubfnmain(){}