diff --git a/compiler/rustc_lint/src/types/improper_ctypes.rs b/compiler/rustc_lint/src/types/improper_ctypes.rs index 9f10cba64cd43..865112219cc2d 100644 --- a/compiler/rustc_lint/src/types/improper_ctypes.rs +++ b/compiler/rustc_lint/src/types/improper_ctypes.rs @@ -138,6 +138,17 @@ declare_lint_pass!(ImproperCTypesLint => [ USES_POWER_ALIGNMENT ]); +/// Getting the (normalized) type out of a field (for, e.g., an enum variant or a tuple). +#[inline] +fn get_type_from_field<'tcx>( + cx: &LateContext<'tcx>, + field: &ty::FieldDef, + args: GenericArgsRef<'tcx>, +) -> Ty<'tcx> { + let field_ty = field.ty(cx.tcx, args); + cx.tcx.try_normalize_erasing_regions(cx.typing_env(), field_ty).unwrap_or(field_ty) +} + /// Check a variant of a non-exhaustive enum for improper ctypes /// /// We treat `#[non_exhaustive] enum` as "ensure that code will compile if new variants are added". @@ -365,22 +376,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { Self { cx, base_ty, base_fn_mode, cache: FxHashSet::default() } } - /// Checks if the given field's type is "ffi-safe". - fn check_field_type_for_ffi( - &mut self, - state: VisitorState, - field: &ty::FieldDef, - args: GenericArgsRef<'tcx>, - ) -> FfiResult<'tcx> { - let field_ty = field.ty(self.cx.tcx, args); - let field_ty = self - .cx - .tcx - .try_normalize_erasing_regions(self.cx.typing_env(), field_ty) - .unwrap_or(field_ty); - self.visit_type(state, field_ty) - } - /// Checks if the given `VariantDef`'s field types are "ffi-safe". fn check_variant_for_ffi( &mut self, @@ -394,7 +389,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { let transparent_with_all_zst_fields = if def.repr().transparent() { if let Some(field) = super::transparent_newtype_field(self.cx.tcx, variant) { // Transparent newtypes have at most one non-ZST field which needs to be checked.. - match self.check_field_type_for_ffi(state, field, args) { + let field_ty = get_type_from_field(self.cx, field, args); + match self.visit_type(state, field_ty) { FfiUnsafe { ty, .. } if ty.is_unit() => (), r => return r, } @@ -412,7 +408,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { // We can't completely trust `repr(C)` markings, so make sure the fields are actually safe. let mut all_phantom = !variant.fields.is_empty(); for field in &variant.fields { - all_phantom &= match self.check_field_type_for_ffi(state, field, args) { + let field_ty = get_type_from_field(self.cx, field, args); + all_phantom &= match self.visit_type(state, field_ty) { FfiSafe => false, // `()` fields are FFI-safe! FfiUnsafe { ty, .. } if ty.is_unit() => false, @@ -721,22 +718,11 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { } } - if let Some(ty) = self - .cx - .tcx - .try_normalize_erasing_regions(self.cx.typing_env(), ty) - .unwrap_or(ty) - .visit_with(&mut ProhibitOpaqueTypes) - .break_value() - { - Some(FfiResult::FfiUnsafe { - ty, - reason: msg!("opaque types have no C equivalent"), - help: None, - }) - } else { - None - } + ty.visit_with(&mut ProhibitOpaqueTypes).break_value().map(|ty| FfiResult::FfiUnsafe { + ty, + reason: msg!("opaque types have no C equivalent"), + help: None, + }) } /// Check if the type is array and emit an unsafe type lint. @@ -754,12 +740,11 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { /// Determine the FFI-safety of a single (MIR) type, given the context of how it is used. fn check_type(&mut self, state: VisitorState, ty: Ty<'tcx>) -> FfiResult<'tcx> { + let ty = self.cx.tcx.try_normalize_erasing_regions(self.cx.typing_env(), ty).unwrap_or(ty); if let Some(res) = self.visit_for_opaque_ty(ty) { return res; } - let ty = self.cx.tcx.try_normalize_erasing_regions(self.cx.typing_env(), ty).unwrap_or(ty); - // C doesn't really support passing arrays by value - the only way to pass an array by value // is through a struct. So, first test that the top level isn't an array, and then // recursively check the types inside.