diff options
| -rw-r--r-- | compiler/rustc_typeck/src/check/compare_method.rs | 66 | ||||
| -rw-r--r-- | src/test/ui/const-generics/issue-86820.rs | 25 | ||||
| -rw-r--r-- | src/test/ui/const-generics/issue-86820.stderr | 15 |
3 files changed, 106 insertions, 0 deletions
diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs index 12d0c14a3d5..d3586888155 100644 --- a/compiler/rustc_typeck/src/check/compare_method.rs +++ b/compiler/rustc_typeck/src/check/compare_method.rs @@ -66,6 +66,10 @@ crate fn compare_impl_method<'tcx>( { return; } + + if let Err(ErrorReported) = compare_const_param_types(tcx, impl_m, trait_m, trait_item_span) { + return; + } } fn compare_predicate_entailment<'tcx>( @@ -929,6 +933,68 @@ fn compare_synthetic_generics<'tcx>( if error_found { Err(ErrorReported) } else { Ok(()) } } +fn compare_const_param_types<'tcx>( + tcx: TyCtxt<'tcx>, + impl_m: &ty::AssocItem, + trait_m: &ty::AssocItem, + trait_item_span: Option<Span>, +) -> Result<(), ErrorReported> { + let const_params_of = |def_id| { + tcx.generics_of(def_id).params.iter().filter_map(|param| match param.kind { + GenericParamDefKind::Const { .. } => Some(param.def_id), + _ => None, + }) + }; + let const_params_impl = const_params_of(impl_m.def_id); + let const_params_trait = const_params_of(trait_m.def_id); + + for (const_param_impl, const_param_trait) in iter::zip(const_params_impl, const_params_trait) { + let impl_ty = tcx.type_of(const_param_impl); + let trait_ty = tcx.type_of(const_param_trait); + if impl_ty != trait_ty { + let (impl_span, impl_ident) = match tcx.hir().get_if_local(const_param_impl) { + Some(hir::Node::GenericParam(hir::GenericParam { span, name, .. })) => ( + span, + match name { + hir::ParamName::Plain(ident) => Some(ident), + _ => None, + }, + ), + other => bug!( + "expected GenericParam, found {:?}", + other.map_or_else(|| "nothing".to_string(), |n| format!("{:?}", n)) + ), + }; + let trait_span = match tcx.hir().get_if_local(const_param_trait) { + Some(hir::Node::GenericParam(hir::GenericParam { span, .. })) => Some(span), + _ => None, + }; + let mut err = struct_span_err!( + tcx.sess, + *impl_span, + E0053, + "method `{}` has an incompatible const parameter type for trait", + trait_m.ident + ); + err.span_note( + trait_span.map_or_else(|| trait_item_span.unwrap_or(*impl_span), |span| *span), + &format!( + "the const parameter{} has type `{}`, but the declaration \ + in trait `{}` has type `{}`", + &impl_ident.map_or_else(|| "".to_string(), |ident| format!(" `{}`", ident)), + impl_ty, + tcx.def_path_str(trait_m.def_id), + trait_ty + ), + ); + err.emit(); + return Err(ErrorReported); + } + } + + Ok(()) +} + crate fn compare_const_impl<'tcx>( tcx: TyCtxt<'tcx>, impl_c: &ty::AssocItem, diff --git a/src/test/ui/const-generics/issue-86820.rs b/src/test/ui/const-generics/issue-86820.rs new file mode 100644 index 00000000000..04650403c6b --- /dev/null +++ b/src/test/ui/const-generics/issue-86820.rs @@ -0,0 +1,25 @@ +// Regression test for the ICE described in #86820. + +#![allow(unused,dead_code)] +use std::ops::BitAnd; + +const C: fn() = || is_set(); +fn is_set() { + 0xffu8.bit::<0>(); +} + +trait Bits { + fn bit<const I : u8>(self) -> bool; + //~^ NOTE: the const parameter `I` has type `usize`, but the declaration in trait `Bits::bit` has type `u8` +} + +impl Bits for u8 { + fn bit<const I : usize>(self) -> bool { + //~^ ERROR: method `bit` has an incompatible const parameter type for trait [E0053] + let i = 1 << I; + let mask = u8::from(i); + mask & self == mask + } +} + +fn main() {} diff --git a/src/test/ui/const-generics/issue-86820.stderr b/src/test/ui/const-generics/issue-86820.stderr new file mode 100644 index 00000000000..f4396f2f2b0 --- /dev/null +++ b/src/test/ui/const-generics/issue-86820.stderr @@ -0,0 +1,15 @@ +error[E0053]: method `bit` has an incompatible const parameter type for trait + --> $DIR/issue-86820.rs:17:18 + | +LL | fn bit<const I : usize>(self) -> bool { + | ^ + | +note: the const parameter `I` has type `usize`, but the declaration in trait `Bits::bit` has type `u8` + --> $DIR/issue-86820.rs:12:18 + | +LL | fn bit<const I : u8>(self) -> bool; + | ^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0053`. |