From 3e25bcb02093bad56beb1dff6be7dd0d80115fb1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Sat, 10 Dec 2022 17:39:00 -0800 Subject: [PATCH] Mention implementations that satisfy the trait --- .../src/traits/error_reporting/mod.rs | 21 +++++++++++++++++-- .../generic_arg_infer/issue-91614.stderr | 6 ++++++ .../issue-72787.min.stderr | 2 ++ src/test/ui/lifetimes/issue-34979.stderr | 1 + src/test/ui/traits/issue-77982.stderr | 10 ++++++++- src/test/ui/traits/issue-85735.stderr | 3 +++ 6 files changed, 40 insertions(+), 3 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 28351d5ff882..64821b5686a9 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -980,6 +980,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { trait_ref, obligation.cause.body_id, &mut err, + true, ) { // This is *almost* equivalent to // `obligation.cause.code().peel_derives()`, but it gives us the @@ -1015,6 +1016,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { trait_ref, obligation.cause.body_id, &mut err, + true, ); } } @@ -1432,6 +1434,7 @@ trait InferCtxtPrivExt<'tcx> { trait_ref: ty::PolyTraitRef<'tcx>, body_id: hir::HirId, err: &mut Diagnostic, + other: bool, ) -> bool; /// Gets the parent trait chain start @@ -1887,7 +1890,9 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { trait_ref: ty::PolyTraitRef<'tcx>, body_id: hir::HirId, err: &mut Diagnostic, + other: bool, ) -> bool { + let other = if other { "other " } else { "" }; let report = |mut candidates: Vec>, err: &mut Diagnostic| { candidates.sort(); candidates.dedup(); @@ -1938,7 +1943,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { candidates.dedup(); let end = if candidates.len() <= 9 { candidates.len() } else { 8 }; err.help(&format!( - "the following other types implement trait `{}`:{}{}", + "the following {other}types implement trait `{}`:{}{}", trait_ref.print_only_trait_path(), candidates[..end].join(""), if len > 9 { format!("\nand {} others", len - 8) } else { String::new() } @@ -2179,7 +2184,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { trait_ref.skip_binder().substs.types().any(|t| !t.is_ty_infer()); // It doesn't make sense to talk about applicable impls if there are more // than a handful of them. - if impls.len() > 1 && impls.len() < 5 && has_non_region_infer { + if impls.len() > 1 && impls.len() < 10 && has_non_region_infer { self.annotate_source_of_ambiguity(&mut err, &impls, predicate); } else { if self.tainted_by_errors().is_some() { @@ -2187,6 +2192,18 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { return; } err.note(&format!("cannot satisfy `{}`", predicate)); + let impl_candidates = self.find_similar_impl_candidates( + predicate.to_opt_poly_trait_pred().unwrap(), + ); + if impl_candidates.len() < 10 { + self.report_similar_impl_candidates( + impl_candidates, + trait_ref, + body_id.map(|id| id.hir_id).unwrap_or(obligation.cause.body_id), + &mut err, + false, + ); + } } } _ => { diff --git a/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr b/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr index 688db695fa84..2cfc6f61f1a5 100644 --- a/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr +++ b/src/test/ui/const-generics/generic_arg_infer/issue-91614.stderr @@ -5,6 +5,12 @@ LL | let y = Mask::<_, _>::splat(false); | ^ ------------------- type must be known at this point | = note: cannot satisfy `_: MaskElement` + = help: the following types implement trait `MaskElement`: + i16 + i32 + i64 + i8 + isize note: required by a bound in `Mask::::splat` --> $SRC_DIR/core/src/../../portable-simd/crates/core_simd/src/masks.rs:LL:COL | diff --git a/src/test/ui/const-generics/generic_const_exprs/issue-72787.min.stderr b/src/test/ui/const-generics/generic_const_exprs/issue-72787.min.stderr index 4d0d0253f1b6..e0444042614b 100644 --- a/src/test/ui/const-generics/generic_const_exprs/issue-72787.min.stderr +++ b/src/test/ui/const-generics/generic_const_exprs/issue-72787.min.stderr @@ -41,6 +41,7 @@ LL | IsLessOrEqual: True, | ^^^^ | = note: cannot satisfy `IsLessOrEqual: True` + = help: the trait `True` is implemented for `IsLessOrEqual` error[E0283]: type annotations needed: cannot satisfy `IsLessOrEqual: True` --> $DIR/issue-72787.rs:21:26 @@ -49,6 +50,7 @@ LL | IsLessOrEqual: True, | ^^^^ | = note: cannot satisfy `IsLessOrEqual: True` + = help: the trait `True` is implemented for `IsLessOrEqual` error: aborting due to 6 previous errors diff --git a/src/test/ui/lifetimes/issue-34979.stderr b/src/test/ui/lifetimes/issue-34979.stderr index 5832c4d173c1..a332c6547b83 100644 --- a/src/test/ui/lifetimes/issue-34979.stderr +++ b/src/test/ui/lifetimes/issue-34979.stderr @@ -5,6 +5,7 @@ LL | &'a (): Foo, | ^^^ | = note: cannot satisfy `&'a (): Foo` + = help: the trait `Foo` is implemented for `&'a T` error: aborting due to previous error diff --git a/src/test/ui/traits/issue-77982.stderr b/src/test/ui/traits/issue-77982.stderr index b6a04585583c..be7397fdb12d 100644 --- a/src/test/ui/traits/issue-77982.stderr +++ b/src/test/ui/traits/issue-77982.stderr @@ -46,7 +46,15 @@ LL | let ips: Vec<_> = (0..100_000).map(|_| u32::from(0u32.into())).collect( | | | required by a bound introduced by this call | - = note: cannot satisfy `u32: From<_>` + = note: multiple `impl`s satisfying `u32: From<_>` found in the following crates: `core`, `std`: + - impl From for u32; + - impl From for u32; + - impl From for u32; + - impl From for u32; + - impl From for u32; + - impl From for u32; + - impl From for T; + - impl From for T; help: try using a fully qualified path to specify the expected types | LL | let ips: Vec<_> = (0..100_000).map(|_| u32::from(>::into(0u32))).collect(); diff --git a/src/test/ui/traits/issue-85735.stderr b/src/test/ui/traits/issue-85735.stderr index fa280135beb2..930708f9ad80 100644 --- a/src/test/ui/traits/issue-85735.stderr +++ b/src/test/ui/traits/issue-85735.stderr @@ -5,6 +5,9 @@ LL | T: FnMut(&'a ()), | ^^^^^^^^^^^^^ | = note: cannot satisfy `T: FnMut<(&'a (),)>` + = help: the following types implement trait `FnMut`: + &F + &mut F error: aborting due to previous error