diff options
Diffstat (limited to 'compiler/rustc_lint/src')
| -rw-r--r-- | compiler/rustc_lint/src/nonstandard_style.rs | 10 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/types.rs | 96 |
2 files changed, 68 insertions, 38 deletions
diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs index a3e7c84584d..d1138e8f1fa 100644 --- a/compiler/rustc_lint/src/nonstandard_style.rs +++ b/compiler/rustc_lint/src/nonstandard_style.rs @@ -422,6 +422,16 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase { } } + fn check_ty(&mut self, cx: &LateContext<'_>, ty: &hir::Ty<'_, hir::AmbigArg>) { + if let hir::TyKind::BareFn(hir::BareFnTy { param_idents, .. }) = &ty.kind { + for param_ident in *param_idents { + if let Some(param_ident) = param_ident { + self.check_snake_case(cx, "variable", param_ident); + } + } + } + } + fn check_trait_item(&mut self, cx: &LateContext<'_>, item: &hir::TraitItem<'_>) { if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(param_idents)) = item.kind { self.check_snake_case(cx, "trait method", &item.ident); diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index 7b6a723b0b4..f1c06dfe6ce 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -755,10 +755,10 @@ declare_lint! { /// *subsequent* fields of the associated structs to use an alignment value /// where the floating-point type is aligned on a 4-byte boundary. /// - /// The power alignment rule for structs needed for C compatibility is - /// unimplementable within `repr(C)` in the compiler without building in - /// handling of references to packed fields and infectious nested layouts, - /// so a warning is produced in these situations. + /// Effectively, subsequent floating-point fields act as-if they are `repr(packed(4))`. This + /// would be unsound to do in a `repr(C)` type without all the restrictions that come with + /// `repr(packed)`. Rust instead chooses a layout that maintains soundness of Rust code, at the + /// expense of incompatibility with C code. /// /// ### Example /// @@ -790,8 +790,10 @@ declare_lint! { /// - offset_of!(Floats, a) == 0 /// - offset_of!(Floats, b) == 8 /// - offset_of!(Floats, c) == 12 - /// However, rust currently aligns `c` at offset_of!(Floats, c) == 16. - /// Thus, a warning should be produced for the above struct in this case. + /// + /// However, Rust currently aligns `c` at `offset_of!(Floats, c) == 16`. + /// Using offset 12 would be unsound since `f64` generally must be 8-aligned on this target. + /// Thus, a warning is produced for the above struct. USES_POWER_ALIGNMENT, Warn, "Structs do not follow the power alignment rule under repr(C)" @@ -878,25 +880,36 @@ fn ty_is_known_nonnull<'tcx>( } ty::Pat(base, pat) => { ty_is_known_nonnull(tcx, typing_env, *base, mode) - || Option::unwrap_or_default( - try { - match **pat { - ty::PatternKind::Range { start, end } => { - let start = start.try_to_value()?.try_to_bits(tcx, typing_env)?; - let end = end.try_to_value()?.try_to_bits(tcx, typing_env)?; - - // This also works for negative numbers, as we just need - // to ensure we aren't wrapping over zero. - start > 0 && end >= start - } - } - }, - ) + || pat_ty_is_known_nonnull(tcx, typing_env, *pat) } _ => false, } } +fn pat_ty_is_known_nonnull<'tcx>( + tcx: TyCtxt<'tcx>, + typing_env: ty::TypingEnv<'tcx>, + pat: ty::Pattern<'tcx>, +) -> bool { + Option::unwrap_or_default( + try { + match *pat { + ty::PatternKind::Range { start, end } => { + let start = start.try_to_value()?.try_to_bits(tcx, typing_env)?; + let end = end.try_to_value()?.try_to_bits(tcx, typing_env)?; + + // This also works for negative numbers, as we just need + // to ensure we aren't wrapping over zero. + start > 0 && end >= start + } + ty::PatternKind::Or(patterns) => { + patterns.iter().all(|pat| pat_ty_is_known_nonnull(tcx, typing_env, pat)) + } + } + }, + ) +} + /// Given a non-null scalar (or transparent) type `ty`, return the nullable version of that type. /// If the type passed in was not scalar, returns None. fn get_nullable_type<'tcx>( @@ -1038,13 +1051,29 @@ pub(crate) fn repr_nullable_ptr<'tcx>( } None } - ty::Pat(base, pat) => match **pat { - ty::PatternKind::Range { .. } => get_nullable_type(tcx, typing_env, *base), - }, + ty::Pat(base, pat) => get_nullable_type_from_pat(tcx, typing_env, *base, *pat), _ => None, } } +fn get_nullable_type_from_pat<'tcx>( + tcx: TyCtxt<'tcx>, + typing_env: ty::TypingEnv<'tcx>, + base: Ty<'tcx>, + pat: ty::Pattern<'tcx>, +) -> Option<Ty<'tcx>> { + match *pat { + ty::PatternKind::Range { .. } => get_nullable_type(tcx, typing_env, base), + ty::PatternKind::Or(patterns) => { + let first = get_nullable_type_from_pat(tcx, typing_env, base, patterns[0])?; + for &pat in &patterns[1..] { + assert_eq!(first, get_nullable_type_from_pat(tcx, typing_env, base, pat)?); + } + Some(first) + } + } +} + impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { /// Check if the type is array and emit an unsafe type lint. fn check_for_array_ty(&mut self, sp: Span, ty: Ty<'tcx>) -> bool { @@ -1628,15 +1657,13 @@ impl ImproperCTypesDefinitions { cx: &LateContext<'tcx>, ty: Ty<'tcx>, ) -> bool { + assert!(cx.tcx.sess.target.os == "aix"); // Structs (under repr(C)) follow the power alignment rule if: // - the first field of the struct is a floating-point type that // is greater than 4-bytes, or // - the first field of the struct is an aggregate whose // recursively first field is a floating-point type greater than // 4 bytes. - if cx.tcx.sess.target.os != "aix" { - return false; - } if ty.is_floating_point() && ty.primitive_size(cx.tcx).bytes() > 4 { return true; } else if let Adt(adt_def, _) = ty.kind() @@ -1674,21 +1701,14 @@ impl ImproperCTypesDefinitions { && !adt_def.all_fields().next().is_none() { let struct_variant_data = item.expect_struct().1; - for (index, ..) in struct_variant_data.fields().iter().enumerate() { + for field_def in struct_variant_data.fields().iter().skip(1) { // Struct fields (after the first field) are checked for the // power alignment rule, as fields after the first are likely // to be the fields that are misaligned. - if index != 0 { - let first_field_def = struct_variant_data.fields()[index]; - let def_id = first_field_def.def_id; - let ty = cx.tcx.type_of(def_id).instantiate_identity(); - if self.check_arg_for_power_alignment(cx, ty) { - cx.emit_span_lint( - USES_POWER_ALIGNMENT, - first_field_def.span, - UsesPowerAlignment, - ); - } + let def_id = field_def.def_id; + let ty = cx.tcx.type_of(def_id).instantiate_identity(); + if self.check_arg_for_power_alignment(cx, ty) { + cx.emit_span_lint(USES_POWER_ALIGNMENT, field_def.span, UsesPowerAlignment); } } } |