diff options
Diffstat (limited to 'compiler')
4 files changed, 101 insertions, 66 deletions
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs index 6e5a0c813ac..0aa7b117b89 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -226,7 +226,7 @@ impl Qualif for CustomEq { // because that component may be part of an enum variant (e.g., // `Option::<NonStructuralMatchTy>::Some`), in which case some values of this type may be // structural-match (`Option::None`). - traits::search_for_structural_match_violation(cx.body.span, cx.tcx, ty).is_some() + traits::search_for_structural_match_violation(cx.body.span, cx.tcx, ty, true).is_some() } fn in_adt_inherently<'tcx>( diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index f22f3f61a01..e32e0b11ba4 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -120,32 +120,37 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { } fn search_for_structural_match_violation(&self, ty: Ty<'tcx>) -> Option<String> { - traits::search_for_structural_match_violation(self.span, self.tcx(), ty).map(|non_sm_ty| { - with_no_trimmed_paths!(match non_sm_ty.kind { - traits::NonStructuralMatchTyKind::Adt(adt) => self.adt_derive_msg(adt), - traits::NonStructuralMatchTyKind::Dynamic => { - "trait objects cannot be used in patterns".to_string() - } - traits::NonStructuralMatchTyKind::Opaque => { - "opaque types cannot be used in patterns".to_string() - } - traits::NonStructuralMatchTyKind::Closure => { - "closures cannot be used in patterns".to_string() - } - traits::NonStructuralMatchTyKind::Generator => { - "generators cannot be used in patterns".to_string() - } - traits::NonStructuralMatchTyKind::Param => { - bug!("use of a constant whose type is a parameter inside a pattern") - } - traits::NonStructuralMatchTyKind::Projection => { - bug!("use of a constant whose type is a projection inside a pattern") - } - traits::NonStructuralMatchTyKind::Foreign => { - bug!("use of a value of a foreign type inside a pattern") - } - }) - }) + traits::search_for_structural_match_violation(self.span, self.tcx(), ty, true).map( + |non_sm_ty| { + with_no_trimmed_paths!(match non_sm_ty.kind { + traits::NonStructuralMatchTyKind::Adt(adt) => self.adt_derive_msg(adt), + traits::NonStructuralMatchTyKind::Dynamic => { + "trait objects cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::Opaque => { + "opaque types cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::Closure => { + "closures cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::Generator => { + "generators cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::Float => { + "floating-point numbers cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::Param => { + bug!("use of a constant whose type is a parameter inside a pattern") + } + traits::NonStructuralMatchTyKind::Projection => { + bug!("use of a constant whose type is a projection inside a pattern") + } + traits::NonStructuralMatchTyKind::Foreign => { + bug!("use of a value of a foreign type inside a pattern") + } + }) + }, + ) } fn type_marked_structural(&self, ty: Ty<'tcx>) -> bool { diff --git a/compiler/rustc_trait_selection/src/traits/structural_match.rs b/compiler/rustc_trait_selection/src/traits/structural_match.rs index 94ca138b9d2..6c0b83fbd03 100644 --- a/compiler/rustc_trait_selection/src/traits/structural_match.rs +++ b/compiler/rustc_trait_selection/src/traits/structural_match.rs @@ -26,6 +26,7 @@ pub enum NonStructuralMatchTyKind<'tcx> { Closure, Generator, Projection, + Float, } /// This method traverses the structure of `ty`, trying to find an @@ -53,12 +54,16 @@ pub enum NonStructuralMatchTyKind<'tcx> { /// For more background on why Rust has this requirement, and issues /// that arose when the requirement was not enforced completely, see /// Rust RFC 1445, rust-lang/rust#61188, and rust-lang/rust#62307. +/// +/// The floats_allowed flag is used to deny constants in floating point pub fn search_for_structural_match_violation<'tcx>( span: Span, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, + floats_allowed: bool, ) -> Option<NonStructuralMatchTy<'tcx>> { - ty.visit_with(&mut Search { tcx, span, seen: FxHashSet::default() }).break_value() + ty.visit_with(&mut Search { tcx, span, seen: FxHashSet::default(), floats_allowed }) + .break_value() } /// This method returns true if and only if `adt_ty` itself has been marked as @@ -119,6 +124,8 @@ struct Search<'tcx> { /// Tracks ADTs previously encountered during search, so that /// we will not recur on them again. seen: FxHashSet<hir::def_id::DefId>, + + floats_allowed: bool, } impl<'tcx> Search<'tcx> { @@ -192,13 +199,24 @@ impl<'tcx> TypeVisitor<'tcx> for Search<'tcx> { // for empty array. return ControlFlow::CONTINUE; } - ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str | ty::Never => { + ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Str | ty::Never => { // These primitive types are always structural match. // // `Never` is kind of special here, but as it is not inhabitable, this should be fine. return ControlFlow::CONTINUE; } + ty::Float(_) => { + if self.floats_allowed { + return ControlFlow::CONTINUE; + } else { + return ControlFlow::Break(NonStructuralMatchTy { + ty, + kind: NonStructuralMatchTyKind::Float, + }); + } + } + ty::Array(..) | ty::Slice(_) | ty::Ref(..) | ty::Tuple(..) => { // First check all contained types and then tell the caller to continue searching. return ty.super_visit_with(self); diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index f93f567fb20..5621cf2e1a4 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -824,50 +824,62 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) { } if let Some(non_structural_match_ty) = - traits::search_for_structural_match_violation(param.span, tcx, ty) + traits::search_for_structural_match_violation(param.span, tcx, ty, false) { // We use the same error code in both branches, because this is really the same // issue: we just special-case the message for type parameters to make it // clearer. - if let ty::Param(_) = ty.peel_refs().kind() { - // Const parameters may not have type parameters as their types, - // because we cannot be sure that the type parameter derives `PartialEq` - // and `Eq` (just implementing them is not enough for `structural_match`). - struct_span_err!( - tcx.sess, - hir_ty.span, - E0741, - "`{}` is not guaranteed to `#[derive(PartialEq, Eq)]`, so may not be \ - used as the type of a const parameter", - ty, - ) - .span_label( - hir_ty.span, - format!("`{}` may not derive both `PartialEq` and `Eq`", ty), - ) - .note( - "it is not currently possible to use a type parameter as the type of a \ - const parameter", - ) - .emit(); - } else { - let mut diag = struct_span_err!( - tcx.sess, - hir_ty.span, - E0741, - "`{}` must be annotated with `#[derive(PartialEq, Eq)]` to be used as \ - the type of a const parameter", - non_structural_match_ty.ty, - ); - - if ty == non_structural_match_ty.ty { - diag.span_label( + match ty.peel_refs().kind() { + ty::Param(_) => { + // Const parameters may not have type parameters as their types, + // because we cannot be sure that the type parameter derives `PartialEq` + // and `Eq` (just implementing them is not enough for `structural_match`). + struct_span_err!( + tcx.sess, hir_ty.span, - format!("`{ty}` doesn't derive both `PartialEq` and `Eq`"), - ); + E0741, + "`{ty}` is not guaranteed to `#[derive(PartialEq, Eq)]`, so may not be \ + used as the type of a const parameter", + ) + .span_label( + hir_ty.span, + format!("`{ty}` may not derive both `PartialEq` and `Eq`"), + ) + .note( + "it is not currently possible to use a type parameter as the type of a \ + const parameter", + ) + .emit(); + } + ty::Float(_) => { + struct_span_err!( + tcx.sess, + hir_ty.span, + E0741, + "`{ty}` is forbidden as the type of a const generic parameter", + ) + .note("floats do not derive `Eq` or `Ord`, which are required for const parameters") + .emit(); } + _ => { + let mut diag = struct_span_err!( + tcx.sess, + hir_ty.span, + E0741, + "`{}` must be annotated with `#[derive(PartialEq, Eq)]` to be used as \ + the type of a const parameter", + non_structural_match_ty.ty, + ); - diag.emit(); + if ty == non_structural_match_ty.ty { + diag.span_label( + hir_ty.span, + format!("`{ty}` doesn't derive both `PartialEq` and `Eq`"), + ); + } + + diag.emit(); + } } } } else { |