diff options
4 files changed, 55 insertions, 14 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index 761b217c78f..6eb6164846c 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -730,7 +730,10 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { }; let found_did = match *found_trait_ty.kind() { - ty::Closure(did, _) | ty::Foreign(did) | ty::FnDef(did, _) => Some(did), + ty::Closure(did, _) + | ty::Foreign(did) + | ty::FnDef(did, _) + | ty::Generator(did, ..) => Some(did), ty::Adt(def, _) => Some(def.did), _ => None, }; diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index 9371ff3405e..362a5f47ffe 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -1250,33 +1250,40 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { trait_ref: ty::PolyTraitRef<'tcx>, ) -> String { let inputs = trait_ref.skip_binder().substs.type_at(1); - let sig = if let ty::Tuple(inputs) = inputs.kind() { - tcx.mk_fn_sig( - inputs.iter().map(|k| k.expect_ty()), - tcx.mk_ty_infer(ty::TyVar(ty::TyVid::from_u32(0))), - false, - hir::Unsafety::Normal, - abi::Abi::Rust, - ) - } else { - tcx.mk_fn_sig( + let sig = match inputs.kind() { + ty::Tuple(inputs) + if tcx.fn_trait_kind_from_lang_item(trait_ref.def_id()).is_some() => + { + tcx.mk_fn_sig( + inputs.iter().map(|k| k.expect_ty()), + tcx.mk_ty_infer(ty::TyVar(ty::TyVid::from_u32(0))), + false, + hir::Unsafety::Normal, + abi::Abi::Rust, + ) + } + _ => tcx.mk_fn_sig( std::iter::once(inputs), tcx.mk_ty_infer(ty::TyVar(ty::TyVid::from_u32(0))), false, hir::Unsafety::Normal, abi::Abi::Rust, - ) + ), }; trait_ref.rebind(sig).to_string() } - let argument_is_closure = expected_ref.skip_binder().substs.type_at(0).is_closure(); + let argument_kind = match expected_ref.skip_binder().substs.type_at(0) { + t if t.is_closure() => "closure", + t if t.is_generator() => "generator", + _ => "function", + }; let mut err = struct_span_err!( self.tcx.sess, span, E0631, "type mismatch in {} arguments", - if argument_is_closure { "closure" } else { "function" } + argument_kind ); let found_str = format!("expected signature of `{}`", build_fn_sig_string(self.tcx, found)); diff --git a/src/test/ui/generator/issue-88653.rs b/src/test/ui/generator/issue-88653.rs new file mode 100644 index 00000000000..ce9159b53e0 --- /dev/null +++ b/src/test/ui/generator/issue-88653.rs @@ -0,0 +1,19 @@ +// Regression test for #88653, where a confusing warning about a +// type mismatch in generator arguments was issued. + +#![feature(generators, generator_trait)] + +use std::ops::Generator; + +fn foo(bar: bool) -> impl Generator<(bool,)> { +//~^ ERROR: type mismatch in generator arguments [E0631] +//~| NOTE: expected signature of `fn((bool,)) -> _` + |bar| { + //~^ NOTE: found signature of `fn(bool) -> _` + if bar { + yield bar; + } + } +} + +fn main() {} diff --git a/src/test/ui/generator/issue-88653.stderr b/src/test/ui/generator/issue-88653.stderr new file mode 100644 index 00000000000..5bd8ad129fe --- /dev/null +++ b/src/test/ui/generator/issue-88653.stderr @@ -0,0 +1,12 @@ +error[E0631]: type mismatch in generator arguments + --> $DIR/issue-88653.rs:8:22 + | +LL | fn foo(bar: bool) -> impl Generator<(bool,)> { + | ^^^^^^^^^^^^^^^^^^^^^^^ expected signature of `fn((bool,)) -> _` +... +LL | |bar| { + | ----- found signature of `fn(bool) -> _` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0631`. |