diff options
Diffstat (limited to 'compiler/rustc_lint/src')
| -rw-r--r-- | compiler/rustc_lint/src/lib.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/lints.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/reference_casting.rs (renamed from compiler/rustc_lint/src/cast_ref_to_mut.rs) | 15 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/types.rs | 104 |
4 files changed, 62 insertions, 69 deletions
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index 5e3f057d428..602071a55e5 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -50,7 +50,6 @@ extern crate tracing; mod array_into_iter; pub mod builtin; -mod cast_ref_to_mut; mod context; mod deref_into_dyn_supertrait; mod drop_forget_useless; @@ -77,6 +76,7 @@ mod opaque_hidden_inferred_bound; mod pass_by_value; mod passes; mod redundant_semicolon; +mod reference_casting; mod traits; mod types; mod unused; @@ -98,7 +98,6 @@ use rustc_span::Span; use array_into_iter::ArrayIntoIter; use builtin::*; -use cast_ref_to_mut::*; use deref_into_dyn_supertrait::*; use drop_forget_useless::*; use enum_intrinsics_non_enums::EnumIntrinsicsNonEnums; @@ -117,6 +116,7 @@ use noop_method_call::*; use opaque_hidden_inferred_bound::*; use pass_by_value::*; use redundant_semicolon::*; +use reference_casting::*; use traits::*; use types::*; use unused::*; @@ -216,7 +216,7 @@ late_lint_methods!( BoxPointers: BoxPointers, PathStatements: PathStatements, LetUnderscore: LetUnderscore, - CastRefToMut: CastRefToMut, + InvalidReferenceCasting: InvalidReferenceCasting, // Depends on referenced function signatures in expressions UnusedResults: UnusedResults, NonUpperCaseGlobals: NonUpperCaseGlobals, diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 0613ef2c5e9..9260237fbee 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -737,10 +737,10 @@ pub enum InvalidFromUtf8Diag { }, } -// cast_ref_to_mut.rs +// reference_casting.rs #[derive(LintDiagnostic)] -#[diag(lint_cast_ref_to_mut)] -pub struct CastRefToMutDiag; +#[diag(lint_invalid_reference_casting)] +pub struct InvalidReferenceCastingDiag; // hidden_unicode_codepoints.rs #[derive(LintDiagnostic)] diff --git a/compiler/rustc_lint/src/cast_ref_to_mut.rs b/compiler/rustc_lint/src/reference_casting.rs index 84308d48c10..db8d7302a25 100644 --- a/compiler/rustc_lint/src/cast_ref_to_mut.rs +++ b/compiler/rustc_lint/src/reference_casting.rs @@ -3,15 +3,16 @@ use rustc_hir::{Expr, ExprKind, MutTy, TyKind, UnOp}; use rustc_middle::ty; use rustc_span::sym; -use crate::{lints::CastRefToMutDiag, LateContext, LateLintPass, LintContext}; +use crate::{lints::InvalidReferenceCastingDiag, LateContext, LateLintPass, LintContext}; declare_lint! { - /// The `cast_ref_to_mut` lint checks for casts of `&T` to `&mut T` + /// The `invalid_reference_casting` lint checks for casts of `&T` to `&mut T` /// without using interior mutability. /// /// ### Example /// /// ```rust,compile_fail + /// # #![deny(invalid_reference_casting)] /// fn x(r: &i32) { /// unsafe { /// *(r as *const i32 as *mut i32) += 1; @@ -28,14 +29,14 @@ declare_lint! { /// /// `UnsafeCell` is the only way to obtain aliasable data that is considered /// mutable. - CAST_REF_TO_MUT, - Deny, + INVALID_REFERENCE_CASTING, + Allow, "casts of `&T` to `&mut T` without interior mutability" } -declare_lint_pass!(CastRefToMut => [CAST_REF_TO_MUT]); +declare_lint_pass!(InvalidReferenceCasting => [INVALID_REFERENCE_CASTING]); -impl<'tcx> LateLintPass<'tcx> for CastRefToMut { +impl<'tcx> LateLintPass<'tcx> for InvalidReferenceCasting { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { let ExprKind::Unary(UnOp::Deref, e) = &expr.kind else { return; }; @@ -66,7 +67,7 @@ impl<'tcx> LateLintPass<'tcx> for CastRefToMut { let e = e.peel_blocks(); if let ty::Ref(..) = cx.typeck_results().node_type(e.hir_id).kind() { - cx.emit_spanned_lint(CAST_REF_TO_MUT, expr.span, CastRefToMutDiag); + cx.emit_spanned_lint(INVALID_REFERENCE_CASTING, expr.span, InvalidReferenceCastingDiag); } } } diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index 2509d493a4c..ed4fb98605c 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -963,12 +963,12 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { substs: SubstsRef<'tcx>, ) -> FfiResult<'tcx> { let field_ty = field.ty(self.cx.tcx, substs); - if field_ty.has_opaque_types() { - self.check_type_for_ffi(cache, field_ty) - } else { - let field_ty = self.cx.tcx.normalize_erasing_regions(self.cx.param_env, field_ty); - self.check_type_for_ffi(cache, field_ty) - } + let field_ty = self + .cx + .tcx + .try_normalize_erasing_regions(self.cx.param_env, field_ty) + .unwrap_or(field_ty); + self.check_type_for_ffi(cache, field_ty) } /// Checks if the given `VariantDef`'s field types are "ffi-safe". @@ -982,39 +982,43 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { ) -> FfiResult<'tcx> { use FfiResult::*; - let transparent_safety = def.repr().transparent().then(|| { - // Can assume that at most one field is not a ZST, so only check - // that field's type for FFI-safety. + let transparent_with_all_zst_fields = if def.repr().transparent() { if let Some(field) = transparent_newtype_field(self.cx.tcx, variant) { - return self.check_field_type_for_ffi(cache, field, substs); + // Transparent newtypes have at most one non-ZST field which needs to be checked.. + match self.check_field_type_for_ffi(cache, field, substs) { + FfiUnsafe { ty, .. } if ty.is_unit() => (), + r => return r, + } + + false } else { - // All fields are ZSTs; this means that the type should behave - // like (), which is FFI-unsafe... except if all fields are PhantomData, - // which is tested for below - FfiUnsafe { ty, reason: fluent::lint_improper_ctypes_struct_zst, help: None } + // ..or have only ZST fields, which is FFI-unsafe (unless those fields are all + // `PhantomData`). + true } - }); - // We can't completely trust repr(C) markings; make sure the fields are - // actually safe. + } else { + false + }; + + // 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 { - match self.check_field_type_for_ffi(cache, &field, substs) { - FfiSafe => { - all_phantom = false; - } - FfiPhantom(..) if !def.repr().transparent() && def.is_enum() => { - return FfiUnsafe { - ty, - reason: fluent::lint_improper_ctypes_enum_phantomdata, - help: None, - }; - } - FfiPhantom(..) => {} - r => return transparent_safety.unwrap_or(r), + all_phantom &= match self.check_field_type_for_ffi(cache, &field, substs) { + FfiSafe => false, + // `()` fields are FFI-safe! + FfiUnsafe { ty, .. } if ty.is_unit() => false, + FfiPhantom(..) => true, + r @ FfiUnsafe { .. } => return r, } } - if all_phantom { FfiPhantom(ty) } else { transparent_safety.unwrap_or(FfiSafe) } + if all_phantom { + FfiPhantom(ty) + } else if transparent_with_all_zst_fields { + FfiUnsafe { ty, reason: fluent::lint_improper_ctypes_struct_zst, help: None } + } else { + FfiSafe + } } /// Checks if the given type is "ffi-safe" (has a stable, well-defined @@ -1217,25 +1221,19 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { } let sig = tcx.erase_late_bound_regions(sig); - if !sig.output().is_unit() { - let r = self.check_type_for_ffi(cache, sig.output()); - match r { - FfiSafe => {} - _ => { - return r; - } - } - } for arg in sig.inputs() { - let r = self.check_type_for_ffi(cache, *arg); - match r { + match self.check_type_for_ffi(cache, *arg) { FfiSafe => {} - _ => { - return r; - } + r => return r, } } - FfiSafe + + let ret_ty = sig.output(); + if ret_ty.is_unit() { + return FfiSafe; + } + + self.check_type_for_ffi(cache, ret_ty) } ty::Foreign(..) => FfiSafe, @@ -1317,7 +1315,8 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { if let Some(ty) = self .cx .tcx - .normalize_erasing_regions(self.cx.param_env, ty) + .try_normalize_erasing_regions(self.cx.param_env, ty) + .unwrap_or(ty) .visit_with(&mut ProhibitOpaqueTypes) .break_value() { @@ -1335,16 +1334,12 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { is_static: bool, is_return_type: bool, ) { - // We have to check for opaque types before `normalize_erasing_regions`, - // which will replace opaque types with their underlying concrete type. if self.check_for_opaque_ty(sp, ty) { // We've already emitted an error due to an opaque type. return; } - // it is only OK to use this function because extern fns cannot have - // any generic types right now: - let ty = self.cx.tcx.normalize_erasing_regions(self.cx.param_env, ty); + let ty = self.cx.tcx.try_normalize_erasing_regions(self.cx.param_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 @@ -1354,7 +1349,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { } // Don't report FFI errors for unit return types. This check exists here, and not in - // `check_foreign_fn` (where it would make more sense) so that normalization has definitely + // the caller (where it would make more sense) so that normalization has definitely // happened. if is_return_type && ty.is_unit() { return; @@ -1370,9 +1365,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { None, ); } - // If `ty` is a `repr(transparent)` newtype, and the non-zero-sized type is a generic - // argument, which after substitution, is `()`, then this branch can be hit. - FfiResult::FfiUnsafe { ty, .. } if is_return_type && ty.is_unit() => {} FfiResult::FfiUnsafe { ty, reason, help } => { self.emit_ffi_unsafe_type_lint(ty, sp, reason, help); } |