diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs index 132e2ddee2953..039034e57f456 100644 --- a/compiler/rustc_feature/src/unstable.rs +++ b/compiler/rustc_feature/src/unstable.rs @@ -581,6 +581,9 @@ 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 to be used across FFI, if T's niche value can + /// be used to describe E or vise-versa. + (unstable, result_ffi_guarantees, "CURRENT_RUSTC_VERSION", Some(110503)), /// Allows bounding the return type of AFIT/RPITIT. (incomplete, return_type_notation, "1.70.0", Some(109417)), /// Allows `extern "rust-cold"`. diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index 13b6054586cd5..f9f766f832af7 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -1101,6 +1101,32 @@ fn get_nullable_type<'tcx>( }) } +/// A type is niche-optimization candidate iff: +/// - Is a zero-sized type with alignment 1 (a “1-ZST”). +/// - Has no fields. +/// - Does not have the `#[non_exhaustive]` attribute. +fn is_niche_optimization_candidate<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + ty: Ty<'tcx>, +) -> bool { + if tcx.layout_of(param_env.and(ty)).is_ok_and(|layout| !layout.is_1zst()) { + return false; + } + + match ty.kind() { + ty::Adt(ty_def, _) => { + let non_exhaustive = ty_def.is_variant_list_non_exhaustive(); + let empty = (ty_def.is_struct() && ty_def.all_fields().next().is_none()) + || (ty_def.is_enum() && ty_def.variants().is_empty()); + + !non_exhaustive && empty + } + ty::Tuple(tys) => tys.is_empty(), + _ => false, + } +} + /// Check if this enum can be safely exported based on the "nullable pointer optimization". If it /// can, return the type that `ty` can be safely converted to, otherwise return `None`. /// Currently restricted to function pointers, boxes, references, `core::num::NonZero`, @@ -1117,6 +1143,22 @@ pub(crate) fn repr_nullable_ptr<'tcx>( let field_ty = match &ty_def.variants().raw[..] { [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 { + return None; + } + + let ty1 = field1.ty(tcx, args); + let ty2 = field2.ty(tcx, args); + + if is_niche_optimization_candidate(tcx, param_env, ty1) { + ty2 + } else if is_niche_optimization_candidate(tcx, param_env, ty2) { + ty1 + } else { + return None; + } + } _ => return None, }, _ => return None, @@ -1202,7 +1244,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { args: GenericArgsRef<'tcx>, ) -> FfiResult<'tcx> { use FfiResult::*; - let transparent_with_all_zst_fields = if def.repr().transparent() { if let Some(field) = transparent_newtype_field(self.cx.tcx, variant) { // Transparent newtypes have at most one non-ZST field which needs to be checked.. @@ -1329,27 +1370,29 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { return FfiSafe; } + if def.is_variant_list_non_exhaustive() && !def.did().is_local() { + return FfiUnsafe { + ty, + reason: fluent::lint_improper_ctypes_non_exhaustive, + help: None, + }; + } + // Check for a repr() attribute to specify the size of the // discriminant. if !def.repr().c() && !def.repr().transparent() && def.repr().int.is_none() { - // Special-case types like `Option`. - if repr_nullable_ptr(self.cx.tcx, self.cx.param_env, ty, self.mode) - .is_none() + // Special-case types like `Option` and `Result` + if let Some(ty) = + repr_nullable_ptr(self.cx.tcx, self.cx.param_env, ty, self.mode) { - return FfiUnsafe { - ty, - reason: fluent::lint_improper_ctypes_enum_repr_reason, - help: Some(fluent::lint_improper_ctypes_enum_repr_help), - }; + return self.check_type_for_ffi(cache, ty); } - } - if def.is_variant_list_non_exhaustive() && !def.did().is_local() { return FfiUnsafe { ty, - reason: fluent::lint_improper_ctypes_non_exhaustive, - help: None, + reason: fluent::lint_improper_ctypes_enum_repr_reason, + help: Some(fluent::lint_improper_ctypes_enum_repr_help), }; } diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 8d38867ab1f99..b9d5e13256338 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -1510,6 +1510,7 @@ symbols! { require, residual, result, + result_ffi_guarantees, resume, return_position_impl_trait_in_trait, return_type_notation, diff --git a/src/doc/unstable-book/src/language-features/result-ffi-guarantees.md b/src/doc/unstable-book/src/language-features/result-ffi-guarantees.md new file mode 100644 index 0000000000000..dc9c196524ed4 --- /dev/null +++ b/src/doc/unstable-book/src/language-features/result-ffi-guarantees.md @@ -0,0 +1,14 @@ +# `result_ffi_guarantees` + +The tracking issue for this feature is: [#110503] + +[#110503]: https://github.com/rust-lang/rust/issues/110503 + +------------------------ + +This feature adds the possibility of using `Result` in FFI if T's niche +value can be used to describe E or vise-versa. + +See [RFC 3391] for more information. + +[RFC 3391]: https://github.com/rust-lang/rfcs/blob/master/text/3391-result_ffi_guarantees.md diff --git a/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.rs b/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.rs new file mode 100644 index 0000000000000..dda317aecc3c3 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.rs @@ -0,0 +1,99 @@ +#![allow(dead_code)] +#![deny(improper_ctypes)] +#![feature(ptr_internals)] + +use std::num; + +enum Z {} + +#[repr(transparent)] +struct TransparentStruct(T, std::marker::PhantomData); + +#[repr(transparent)] +enum TransparentEnum { + Variant(T, std::marker::PhantomData), +} + +struct NoField; + +extern "C" { + fn result_ref_t(x: Result<&'static u8, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_fn_t(x: Result); + //~^ ERROR `extern` block uses type `Result + fn result_nonnull_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_unique_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u8_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u16_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u32_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u64_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_usize_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i8_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i16_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i32_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i64_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_isize_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_transparent_struct_t(x: Result>, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_transparent_enum_t(x: Result>, ()>); + //~^ ERROR `extern` block uses type `Result + fn result_phantom_t(x: Result, std::marker::PhantomData<()>>); + //~^ ERROR `extern` block uses type `Result + fn result_1zst_exhaustive_no_variant_t(x: Result, Z>); + //~^ ERROR `extern` block uses type `Result + fn result_1zst_exhaustive_no_field_t(x: Result, NoField>); + //~^ ERROR `extern` block uses type `Result + + fn result_ref_e(x: Result<(), &'static u8>); + //~^ ERROR `extern` block uses type `Result + fn result_fn_e(x: Result<(), extern "C" fn()>); + //~^ ERROR `extern` block uses type `Result + fn result_nonnull_e(x: Result<(), std::ptr::NonNull>); + //~^ ERROR `extern` block uses type `Result + fn result_unique_e(x: Result<(), std::ptr::Unique>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u8_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u16_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u32_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_u64_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_usize_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i8_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i16_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i32_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_i64_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_nonzero_isize_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `Result + fn result_transparent_struct_e(x: Result<(), TransparentStruct>>); + //~^ ERROR `extern` block uses type `Result + fn result_transparent_enum_e(x: Result<(), TransparentEnum>>); + //~^ ERROR `extern` block uses type `Result + fn result_phantom_e(x: Result, std::marker::PhantomData<()>>); + //~^ ERROR `extern` block uses type `Result + fn result_1zst_exhaustive_no_variant_e(x: Result>); + //~^ ERROR `extern` block uses type `Result + fn result_1zst_exhaustive_no_field_e(x: Result>); + //~^ ERROR `extern` block uses type `Result +} + +pub fn main() {} diff --git a/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.stderr b/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.stderr new file mode 100644 index 0000000000000..94416eb99c878 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-result_ffi_guarantees.stderr @@ -0,0 +1,349 @@ +error: `extern` block uses type `Result<&u8, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:20:24 + | +LL | fn result_ref_t(x: Result<&'static u8, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^ 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 lint level is defined here + --> $DIR/feature-gate-result_ffi_guarantees.rs:2:9 + | +LL | #![deny(improper_ctypes)] + | ^^^^^^^^^^^^^^^ + +error: `extern` block uses type `Result`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:22:23 + | +LL | fn result_fn_t(x: Result); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:24:28 + | +LL | fn result_nonnull_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:26:27 + | +LL | fn result_unique_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:28:31 + | +LL | fn result_nonzero_u8_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:30:32 + | +LL | fn result_nonzero_u16_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:32:32 + | +LL | fn result_nonzero_u32_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:34:32 + | +LL | fn result_nonzero_u64_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:36:34 + | +LL | fn result_nonzero_usize_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:38:31 + | +LL | fn result_nonzero_i8_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:40:32 + | +LL | fn result_nonzero_i16_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:42:32 + | +LL | fn result_nonzero_i32_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:44:32 + | +LL | fn result_nonzero_i64_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:46:34 + | +LL | fn result_nonzero_isize_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:48:39 + | +LL | fn result_transparent_struct_t(x: Result>, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>, ()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:50:37 + | +LL | fn result_transparent_enum_t(x: Result>, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, PhantomData<()>>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:52:28 + | +LL | fn result_phantom_t(x: Result, std::marker::PhantomData<()>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, Z>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:54:47 + | +LL | fn result_1zst_exhaustive_no_variant_t(x: Result, Z>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, NoField>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:56:45 + | +LL | fn result_1zst_exhaustive_no_field_t(x: Result, NoField>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), &u8>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:59:24 + | +LL | fn result_ref_e(x: Result<(), &'static u8>); + | ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), extern "C" fn()>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:61:23 + | +LL | fn result_fn_e(x: Result<(), extern "C" fn()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonNull>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:63:28 + | +LL | fn result_nonnull_e(x: Result<(), std::ptr::NonNull>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), Unique>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:65:27 + | +LL | fn result_unique_e(x: Result<(), std::ptr::Unique>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:67:31 + | +LL | fn result_nonzero_u8_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:69:32 + | +LL | fn result_nonzero_u16_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:71:32 + | +LL | fn result_nonzero_u32_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:73:32 + | +LL | fn result_nonzero_u64_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:75:34 + | +LL | fn result_nonzero_usize_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:77:31 + | +LL | fn result_nonzero_i8_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:79:32 + | +LL | fn result_nonzero_i16_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:81:32 + | +LL | fn result_nonzero_i32_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:83:32 + | +LL | fn result_nonzero_i64_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:85:34 + | +LL | fn result_nonzero_isize_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), TransparentStruct>>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:87:39 + | +LL | fn result_transparent_struct_e(x: Result<(), TransparentStruct>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), TransparentEnum>>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:89:37 + | +LL | fn result_transparent_enum_e(x: Result<(), TransparentEnum>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, PhantomData<()>>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:91:28 + | +LL | fn result_phantom_e(x: Result, std::marker::PhantomData<()>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:93:47 + | +LL | fn result_1zst_exhaustive_no_variant_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/feature-gate-result_ffi_guarantees.rs:95:45 + | +LL | fn result_1zst_exhaustive_no_field_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: aborting due to 38 previous errors + diff --git a/tests/ui/lint/lint-ctypes-enum.rs b/tests/ui/lint/lint-ctypes-enum.rs index c60290f8553a7..cb8e9e8067513 100644 --- a/tests/ui/lint/lint-ctypes-enum.rs +++ b/tests/ui/lint/lint-ctypes-enum.rs @@ -2,6 +2,7 @@ #![deny(improper_ctypes)] #![feature(ptr_internals)] #![feature(transparent_unions)] +#![feature(result_ffi_guarantees)] use std::num; @@ -55,38 +56,123 @@ union TransparentUnion { struct Rust(T); +struct NoField; + +#[repr(transparent)] +struct Field(()); + +#[non_exhaustive] +enum NonExhaustive {} + extern "C" { - fn zf(x: Z); - fn uf(x: U); //~ ERROR `extern` block uses type `U` - fn bf(x: B); //~ ERROR `extern` block uses type `B` - fn tf(x: T); //~ ERROR `extern` block uses type `T` - fn repr_c(x: ReprC); - fn repr_u8(x: U8); - fn repr_isize(x: Isize); - fn option_ref(x: Option<&'static u8>); - fn option_fn(x: Option); - fn nonnull(x: Option>); - fn unique(x: Option>); - fn nonzero_u8(x: Option>); - fn nonzero_u16(x: Option>); - fn nonzero_u32(x: Option>); - fn nonzero_u64(x: Option>); - fn nonzero_u128(x: Option>); - //~^ ERROR `extern` block uses type `u128` - fn nonzero_usize(x: Option>); - fn nonzero_i8(x: Option>); - fn nonzero_i16(x: Option>); - fn nonzero_i32(x: Option>); - fn nonzero_i64(x: Option>); - fn nonzero_i128(x: Option>); - //~^ ERROR `extern` block uses type `i128` - fn nonzero_isize(x: Option>); - fn transparent_struct(x: Option>>); - fn transparent_enum(x: Option>>); - fn transparent_union(x: Option>>); - //~^ ERROR `extern` block uses type - fn repr_rust(x: Option>>); //~ ERROR `extern` block uses type - fn no_result(x: Result<(), num::NonZero>); //~ ERROR `extern` block uses type + fn zf(x: Z); + fn uf(x: U); //~ ERROR `extern` block uses type `U` + fn bf(x: B); //~ ERROR `extern` block uses type `B` + fn tf(x: T); //~ ERROR `extern` block uses type `T` + fn repr_c(x: ReprC); + fn repr_u8(x: U8); + fn repr_isize(x: Isize); + fn option_ref(x: Option<&'static u8>); + fn option_fn(x: Option); + fn option_nonnull(x: Option>); + fn option_unique(x: Option>); + fn option_nonzero_u8(x: Option>); + fn option_nonzero_u16(x: Option>); + fn option_nonzero_u32(x: Option>); + fn option_nonzero_u64(x: Option>); + fn option_nonzero_u128(x: Option>); + //~^ ERROR `extern` block uses type `u128` + fn option_nonzero_usize(x: Option>); + fn option_nonzero_i8(x: Option>); + fn option_nonzero_i16(x: Option>); + fn option_nonzero_i32(x: Option>); + fn option_nonzero_i64(x: Option>); + fn option_nonzero_i128(x: Option>); + //~^ ERROR `extern` block uses type `i128` + fn option_nonzero_isize(x: Option>); + fn option_transparent_struct(x: Option>>); + fn option_transparent_enum(x: Option>>); + fn option_transparent_union(x: Option>>); + //~^ ERROR `extern` block uses type + fn option_repr_rust(x: Option>>); //~ ERROR `extern` block uses type + + fn result_ref_t(x: Result<&'static u8, ()>); + fn result_fn_t(x: Result); + fn result_nonnull_t(x: Result, ()>); + fn result_unique_t(x: Result, ()>); + fn result_nonzero_u8_t(x: Result, ()>); + fn result_nonzero_u16_t(x: Result, ()>); + fn result_nonzero_u32_t(x: Result, ()>); + fn result_nonzero_u64_t(x: Result, ()>); + fn result_nonzero_u128_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `u128` + fn result_nonzero_usize_t(x: Result, ()>); + fn result_nonzero_i8_t(x: Result, ()>); + fn result_nonzero_i16_t(x: Result, ()>); + fn result_nonzero_i32_t(x: Result, ()>); + fn result_nonzero_i64_t(x: Result, ()>); + fn result_nonzero_i128_t(x: Result, ()>); + //~^ ERROR `extern` block uses type `i128` + fn result_nonzero_isize_t(x: Result, ()>); + fn result_transparent_struct_t(x: Result>, ()>); + fn result_transparent_enum_t(x: Result>, ()>); + fn result_transparent_union_t(x: Result>, ()>); + //~^ ERROR `extern` block uses type + fn result_repr_rust_t(x: Result>, ()>); + //~^ ERROR `extern` block uses type + fn result_phantom_t(x: Result, std::marker::PhantomData<()>>); + fn result_1zst_exhaustive_no_variant_t(x: Result, Z>); + fn result_1zst_exhaustive_single_variant_t(x: Result, U>); + //~^ ERROR `extern` block uses type + fn result_1zst_exhaustive_multiple_variant_t(x: Result, B>); + //~^ ERROR `extern` block uses type + fn result_1zst_non_exhaustive_no_variant_t(x: Result, NonExhaustive>); + //~^ ERROR `extern` block uses type + fn result_1zst_exhaustive_no_field_t(x: Result, NoField>); + fn result_1zst_exhaustive_single_field_t(x: Result, Field>); + //~^ ERROR `extern` block uses type + fn result_cascading_t(x: Result>, ()>); + //~^ ERROR `extern` block uses type + + fn result_ref_e(x: Result<(), &'static u8>); + fn result_fn_e(x: Result<(), extern "C" fn()>); + fn result_nonnull_e(x: Result<(), std::ptr::NonNull>); + fn result_unique_e(x: Result<(), std::ptr::Unique>); + fn result_nonzero_u8_e(x: Result<(), num::NonZero>); + fn result_nonzero_u16_e(x: Result<(), num::NonZero>); + fn result_nonzero_u32_e(x: Result<(), num::NonZero>); + fn result_nonzero_u64_e(x: Result<(), num::NonZero>); + fn result_nonzero_u128_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `u128` + fn result_nonzero_usize_e(x: Result<(), num::NonZero>); + fn result_nonzero_i8_e(x: Result<(), num::NonZero>); + fn result_nonzero_i16_e(x: Result<(), num::NonZero>); + fn result_nonzero_i32_e(x: Result<(), num::NonZero>); + fn result_nonzero_i64_e(x: Result<(), num::NonZero>); + fn result_nonzero_i128_e(x: Result<(), num::NonZero>); + //~^ ERROR `extern` block uses type `i128` + fn result_nonzero_isize_e(x: Result<(), num::NonZero>); + fn result_transparent_struct_e(x: Result<(), TransparentStruct>>); + fn result_transparent_enum_e(x: Result<(), TransparentEnum>>); + fn result_transparent_union_e(x: Result<(), TransparentUnion>>); + //~^ ERROR `extern` block uses type + fn result_repr_rust_e(x: Result<(), Rust>>); + //~^ ERROR `extern` block uses type + fn result_phantom_e(x: Result, std::marker::PhantomData<()>>); + fn result_1zst_exhaustive_no_variant_e(x: Result>); + fn result_1zst_exhaustive_single_variant_e(x: Result>); + //~^ ERROR `extern` block uses type + fn result_1zst_exhaustive_multiple_variant_e(x: Result>); + //~^ ERROR `extern` block uses type + fn result_1zst_non_exhaustive_no_variant_e(x: Result>); + //~^ ERROR `extern` block uses type + fn result_1zst_exhaustive_no_field_e(x: Result>); + fn result_1zst_exhaustive_single_field_e(x: Result>); + //~^ ERROR `extern` block uses type + fn result_cascading_e(x: Result<(), Result<(), num::NonZero>>); + //~^ ERROR `extern` block uses type + fn result_unit_t_e(x: Result<(), ()>); + //~^ ERROR `extern` block uses type } pub fn main() {} diff --git a/tests/ui/lint/lint-ctypes-enum.stderr b/tests/ui/lint/lint-ctypes-enum.stderr index 103fda8d40253..bba5b09b69cc9 100644 --- a/tests/ui/lint/lint-ctypes-enum.stderr +++ b/tests/ui/lint/lint-ctypes-enum.stderr @@ -1,13 +1,13 @@ error: `extern` block uses type `U`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:60:13 + --> $DIR/lint-ctypes-enum.rs:69:14 | -LL | fn uf(x: U); - | ^ not FFI-safe +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:9:1 + --> $DIR/lint-ctypes-enum.rs:10:1 | LL | enum U { | ^^^^^^ @@ -18,75 +18,233 @@ LL | #![deny(improper_ctypes)] | ^^^^^^^^^^^^^^^ error: `extern` block uses type `B`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:61:13 + --> $DIR/lint-ctypes-enum.rs:70:14 | -LL | fn bf(x: B); - | ^ not FFI-safe +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:12:1 + --> $DIR/lint-ctypes-enum.rs:13:1 | LL | enum B { | ^^^^^^ error: `extern` block uses type `T`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:62:13 + --> $DIR/lint-ctypes-enum.rs:71:14 | -LL | fn tf(x: T); - | ^ not FFI-safe +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:16:1 + --> $DIR/lint-ctypes-enum.rs:17:1 | LL | enum T { | ^^^^^^ error: `extern` block uses type `u128`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:74:23 + --> $DIR/lint-ctypes-enum.rs:83:31 | -LL | fn nonzero_u128(x: Option>); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe +LL | fn option_nonzero_u128(x: Option>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ 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:81:23 + --> $DIR/lint-ctypes-enum.rs:90:31 | -LL | fn nonzero_i128(x: Option>); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe +LL | fn option_nonzero_i128(x: Option>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe | = note: 128-bit integers don't currently have a known stable ABI error: `extern` block uses type `Option>>`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:86:28 + --> $DIR/lint-ctypes-enum.rs:95:36 | -LL | fn transparent_union(x: Option>>); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe +LL | fn option_transparent_union(x: Option>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe | = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum = note: enum has no representation hint error: `extern` block uses type `Option>>`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:88:20 + --> $DIR/lint-ctypes-enum.rs:97:28 | -LL | fn repr_rust(x: Option>>); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe +LL | fn option_repr_rust(x: Option>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe | = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum = note: enum has no representation hint -error: `extern` block uses type `Result<(), NonZero>`, which is not FFI-safe - --> $DIR/lint-ctypes-enum.rs:89:20 +error: `extern` block uses type `u128`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:107:33 + | +LL | fn result_nonzero_u128_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 + | +LL | fn result_nonzero_i128_t(x: Result, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = note: 128-bit integers don't currently have a known stable ABI + +error: `extern` block uses type `Result>, ()>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:119:38 + | +LL | fn result_transparent_union_t(x: Result>, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>, ()>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:121:30 + | +LL | fn result_repr_rust_t(x: Result>, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, U>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:125:51 + | +LL | fn result_1zst_exhaustive_single_variant_t(x: Result, 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 + +error: `extern` block uses type `Result, B>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:127:53 + | +LL | fn result_1zst_exhaustive_multiple_variant_t(x: Result, 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 + +error: `extern` block uses type `Result, NonExhaustive>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:129:51 + | +LL | fn result_1zst_non_exhaustive_no_variant_t(x: Result, NonExhaustive>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result, Field>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:132:49 + | +LL | fn result_1zst_exhaustive_single_field_t(x: Result, Field>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>, ()>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:134:30 + | +LL | fn result_cascading_t(x: Result>, ()>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `u128`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:145:33 + | +LL | fn result_nonzero_u128_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 + | +LL | fn result_nonzero_i128_e(x: Result<(), num::NonZero>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = note: 128-bit integers don't currently have a known stable ABI + +error: `extern` block uses type `Result<(), TransparentUnion>>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:157:38 + | +LL | fn result_transparent_union_e(x: Result<(), TransparentUnion>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), Rust>>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:159:30 + | +LL | fn result_repr_rust_e(x: Result<(), Rust>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:163:51 + | +LL | fn result_1zst_exhaustive_single_variant_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:165:53 + | +LL | fn result_1zst_exhaustive_multiple_variant_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:167:51 + | +LL | fn result_1zst_non_exhaustive_no_variant_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:170:49 + | +LL | fn result_1zst_exhaustive_single_field_e(x: Result>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), Result<(), NonZero>>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:172:30 + | +LL | fn result_cascading_e(x: Result<(), Result<(), num::NonZero>>); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe + | + = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum + = note: enum has no representation hint + +error: `extern` block uses type `Result<(), ()>`, which is not FFI-safe + --> $DIR/lint-ctypes-enum.rs:174:27 | -LL | fn no_result(x: Result<(), num::NonZero>); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe +LL | fn result_unit_t_e(x: Result<(), ()>); + | ^^^^^^^^^^^^^^ not FFI-safe | = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum = note: enum has no representation hint -error: aborting due to 8 previous errors +error: aborting due to 26 previous errors