Auto merge of rust-lang#116713 - estebank:issue-116703, r=compiler-er…

…rors Properly account for self ty in method disambiguation suggestion Fix rust-lang#116703.
rust-lang-ci · Oct 18, 2023 · b9832e7 · b9832e7
2 parents 862bba6 + 890e92f
commit b9832e7
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Showing 31 changed files with 588 additions and 98 deletions.
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -1018,7 +1018,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     }
                     err.span_suggestions(
                         span,
-                        "use the fully-qualified path",
+                        "use fully-qualified syntax",
                         suggestions,
                         Applicability::MachineApplicable,
                     );
@@ -1190,7 +1190,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     } else {
                         err.span_suggestion_verbose(
                             span.with_hi(assoc_name.span.lo()),
-                            "use fully qualified syntax to disambiguate",
+                            "use fully-qualified syntax to disambiguate",
                             format!("<{ty_param_name} as {}>::", bound.print_only_trait_path()),
                             Applicability::MaybeIncorrect,
                         );

diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -1260,6 +1260,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Dynamic limit to avoid hiding just one candidate, which is silly.
         let limit = if sources.len() == 5 { 5 } else { 4 };
 
+        let mut suggs = vec![];
         for (idx, source) in sources.iter().take(limit).enumerate() {
             match *source {
                 CandidateSource::Impl(impl_did) => {
@@ -1322,7 +1323,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let path = self.tcx.def_path_str(trait_ref.skip_binder().def_id);
 
                         let ty = match item.kind {
-                            ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty,
+                            ty::AssocKind::Const | ty::AssocKind::Type => impl_ty,
                             ty::AssocKind::Fn => self
                                 .tcx
                                 .fn_sig(item.def_id)
@@ -1334,19 +1335,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 .copied()
                                 .unwrap_or(rcvr_ty),
                         };
-                        print_disambiguation_help(
+                        if let Some(sugg) = print_disambiguation_help(
                             item_name,
                             args,
                             err,
                             path,
                             ty,
+                            Some(impl_ty),
                             item.kind,
                             self.tcx.def_kind_descr(item.kind.as_def_kind(), item.def_id),
                             sugg_span,
                             idx,
                             self.tcx.sess.source_map(),
                             item.fn_has_self_parameter,
-                        );
+                        ) {
+                            suggs.push(sugg);
+                        }
                     }
                 }
                 CandidateSource::Trait(trait_did) => {
@@ -1370,23 +1374,34 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     };
                     if let Some(sugg_span) = sugg_span {
                         let path = self.tcx.def_path_str(trait_did);
-                        print_disambiguation_help(
+                        if let Some(sugg) = print_disambiguation_help(
                             item_name,
                             args,
                             err,
                             path,
                             rcvr_ty,
+                            None,
                             item.kind,
                             self.tcx.def_kind_descr(item.kind.as_def_kind(), item.def_id),
                             sugg_span,
                             idx,
                             self.tcx.sess.source_map(),
                             item.fn_has_self_parameter,
-                        );
+                        ) {
+                            suggs.push(sugg);
+                        }
                     }
                 }
             }
         }
+        if !suggs.is_empty() && let Some(span) = sugg_span {
+            err.span_suggestions(
+                span.with_hi(item_name.span.lo()),
+                "use fully-qualified syntax to disambiguate",
+                suggs,
+                Applicability::MachineApplicable,
+            );
+        }
         if sources.len() > limit {
             err.note(format!("and {} others", sources.len() - limit));
         }
@@ -3146,52 +3161,51 @@ fn print_disambiguation_help<'tcx>(
     err: &mut Diagnostic,
     trait_name: String,
     rcvr_ty: Ty<'_>,
+    impl_self_ty: Option<Ty<'_>>,
     kind: ty::AssocKind,
     def_kind_descr: &'static str,
     span: Span,
     candidate: Option<usize>,
     source_map: &source_map::SourceMap,
     fn_has_self_parameter: bool,
-) {
-    let mut applicability = Applicability::MachineApplicable;
-    let (span, sugg) = if let (
-        ty::AssocKind::Fn,
-        Some(MethodCallComponents { receiver, args, .. }),
-    ) = (kind, args)
-    {
-        let args = format!(
-            "({}{})",
-            rcvr_ty.ref_mutability().map_or("", |mutbl| mutbl.ref_prefix_str()),
-            std::iter::once(receiver)
-                .chain(args.iter())
-                .map(|arg| source_map.span_to_snippet(arg.span).unwrap_or_else(|_| {
-                    applicability = Applicability::HasPlaceholders;
-                    "_".to_owned()
-                }))
-                .collect::<Vec<_>>()
-                .join(", "),
-        );
-        let trait_name = if !fn_has_self_parameter {
-            format!("<{rcvr_ty} as {trait_name}>")
+) -> Option<String> {
+    Some(
+        if let (ty::AssocKind::Fn, Some(MethodCallComponents { receiver, args, .. })) = (kind, args)
+        {
+            let args = format!(
+                "({}{})",
+                rcvr_ty.ref_mutability().map_or("", |mutbl| mutbl.ref_prefix_str()),
+                std::iter::once(receiver)
+                    .chain(args.iter())
+                    .map(|arg| source_map
+                        .span_to_snippet(arg.span)
+                        .unwrap_or_else(|_| { "_".to_owned() }))
+                    .collect::<Vec<_>>()
+                    .join(", "),
+            );
+            let trait_name = if !fn_has_self_parameter && let Some(impl_self_ty) = impl_self_ty {
+            format!("<{impl_self_ty} as {trait_name}>")
         } else {
             trait_name
         };
-        (span, format!("{trait_name}::{item_name}{args}"))
-    } else {
-        (span.with_hi(item_name.span.lo()), format!("<{rcvr_ty} as {trait_name}>::"))
-    };
-    err.span_suggestion_verbose(
-        span,
-        format!(
-            "disambiguate the {} for {}",
-            def_kind_descr,
-            if let Some(candidate) = candidate {
-                format!("candidate #{candidate}")
-            } else {
-                "the candidate".to_string()
-            },
-        ),
-        sugg,
-        applicability,
-    );
+            err.span_suggestion_verbose(
+                span,
+                format!(
+                    "disambiguate the {def_kind_descr} for {}",
+                    if let Some(candidate) = candidate {
+                        format!("candidate #{candidate}")
+                    } else {
+                        "the candidate".to_string()
+                    },
+                ),
+                format!("{trait_name}::{item_name}{args}"),
+                Applicability::HasPlaceholders,
+            );
+            return None;
+        } else if let Some(impl_self_ty) = impl_self_ty {
+            format!("<{impl_self_ty} as {trait_name}>::")
+        } else {
+            format!("{trait_name}::")
+        },
+    )
 }
diff --git a/tests/ui/associated-consts/associated-const-ambiguity-report.stderr b/tests/ui/associated-consts/associated-const-ambiguity-report.stderr
@@ -14,14 +14,12 @@ note: candidate #2 is defined in an impl of the trait `Bar` for the type `i32`
    |
 LL |     const ID: i32 = 3;
    |     ^^^^^^^^^^^^^
-help: disambiguate the associated constant for candidate #1
-   |
-LL | const X: i32 = <i32 as Foo>::ID;
-   |                ~~~~~~~~~~~~~~
-help: disambiguate the associated constant for candidate #2
+help: use fully-qualified syntax to disambiguate
    |
 LL | const X: i32 = <i32 as Bar>::ID;
    |                ~~~~~~~~~~~~~~
+LL | const X: i32 = <i32 as Foo>::ID;
+   |                ~~~~~~~~~~~~~~
 
 error: aborting due to previous error
 

diff --git a/tests/ui/associated-inherent-types/issue-109071.no_gate.stderr b/tests/ui/associated-inherent-types/issue-109071.no_gate.stderr
@@ -33,7 +33,7 @@ error[E0223]: ambiguous associated type
   --> $DIR/issue-109071.rs:15:22
    |
 LL |     fn T() -> Option<Self::Item> {}
-   |                      ^^^^^^^^^^ help: use the fully-qualified path: `<Windows<T> as IntoIterator>::Item`
+   |                      ^^^^^^^^^^ help: use fully-qualified syntax: `<Windows<T> as IntoIterator>::Item`
 
 error: aborting due to 4 previous errors
 

diff --git a/...sociated-inherent-types/not-found-self-type-differs-shadowing-trait-item.uncovered.stderr b/...sociated-inherent-types/not-found-self-type-differs-shadowing-trait-item.uncovered.stderr
@@ -2,7 +2,7 @@ error[E0223]: ambiguous associated type
   --> $DIR/not-found-self-type-differs-shadowing-trait-item.rs:28:12
    |
 LL |     let _: S::<bool>::Pr = ();
-   |            ^^^^^^^^^^^^^ help: use the fully-qualified path: `<S<bool> as Tr>::Pr`
+   |            ^^^^^^^^^^^^^ help: use fully-qualified syntax: `<S<bool> as Tr>::Pr`
 
 error: aborting due to previous error
 

diff --git a/tests/ui/associated-item/ambiguous-associated-type-with-generics.stderr b/tests/ui/associated-item/ambiguous-associated-type-with-generics.stderr
@@ -2,7 +2,7 @@ error[E0223]: ambiguous associated type
   --> $DIR/ambiguous-associated-type-with-generics.rs:13:13
    |
 LL |     let _x: <dyn Trait<i32>>::Ty;
-   |             ^^^^^^^^^^^^^^^^^^^^ help: use the fully-qualified path: `<dyn Trait<i32> as Assoc>::Ty`
+   |             ^^^^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<dyn Trait<i32> as Assoc>::Ty`
 
 error: aborting due to previous error
 

diff --git a/tests/ui/associated-item/associated-item-duplicate-names-3.stderr b/tests/ui/associated-item/associated-item-duplicate-names-3.stderr
@@ -13,7 +13,7 @@ error[E0223]: ambiguous associated type
   --> $DIR/associated-item-duplicate-names-3.rs:18:12
    |
 LL |     let x: Baz::Bar = 5;
-   |            ^^^^^^^^ help: use the fully-qualified path: `<Baz as Foo>::Bar`
+   |            ^^^^^^^^ help: use fully-qualified syntax: `<Baz as Foo>::Bar`
 
 error: aborting due to 2 previous errors
 

diff --git a/...i/associated-types/associated-type-projection-ambig-between-bound-and-where-clause.stderr b/...i/associated-types/associated-type-projection-ambig-between-bound-and-where-clause.stderr
@@ -10,11 +10,11 @@ LL |     type Color;
 LL | fn a<C:Vehicle+Box>(_: C::Color) {
    |                        ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn a<C:Vehicle+Box>(_: <C as Box>::Color) {
    |                        ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn a<C:Vehicle+Box>(_: <C as Vehicle>::Color) {
    |                        ~~~~~~~~~~~~~~~~
@@ -31,11 +31,11 @@ LL |     type Color;
 LL | fn b<C>(_: C::Color) where C : Vehicle+Box {
    |            ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn b<C>(_: <C as Box>::Color) where C : Vehicle+Box {
    |            ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn b<C>(_: <C as Vehicle>::Color) where C : Vehicle+Box {
    |            ~~~~~~~~~~~~~~~~
@@ -52,11 +52,11 @@ LL |     type Color;
 LL | fn c<C>(_: C::Color) where C : Vehicle, C : Box {
    |            ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn c<C>(_: <C as Box>::Color) where C : Vehicle, C : Box {
    |            ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn c<C>(_: <C as Vehicle>::Color) where C : Vehicle, C : Box {
    |            ~~~~~~~~~~~~~~~~
@@ -73,11 +73,11 @@ LL |     type Color;
 LL |     fn e(&self, _: X::Color) where X : Box;
    |                    ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn e(&self, _: <X as Box>::Color) where X : Box;
    |                    ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn e(&self, _: <X as Vehicle>::Color) where X : Box;
    |                    ~~~~~~~~~~~~~~~~
@@ -94,11 +94,11 @@ LL |     type Color;
 LL |     fn f(&self, _: X::Color) where X : Box { }
    |                    ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn f(&self, _: <X as Box>::Color) where X : Box { }
    |                    ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn f(&self, _: <X as Vehicle>::Color) where X : Box { }
    |                    ~~~~~~~~~~~~~~~~
@@ -115,11 +115,11 @@ LL |     type Color;
 LL |     fn d(&self, _: X::Color) where X : Box { }
    |                    ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn d(&self, _: <X as Box>::Color) where X : Box { }
    |                    ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL |     fn d(&self, _: <X as Vehicle>::Color) where X : Box { }
    |                    ~~~~~~~~~~~~~~~~

diff --git a/tests/ui/associated-types/associated-type-projection-from-multiple-supertraits.stderr b/tests/ui/associated-types/associated-type-projection-from-multiple-supertraits.stderr
@@ -18,11 +18,11 @@ LL |     type Color;
 LL | fn dent<C:BoxCar>(c: C, color: C::Color) {
    |                                ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn dent<C:BoxCar>(c: C, color: <C as Vehicle>::Color) {
    |                                ~~~~~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn dent<C:BoxCar>(c: C, color: <C as Box>::Color) {
    |                                ~~~~~~~~~~~~
@@ -71,11 +71,11 @@ LL |     type Color;
 LL | fn paint<C:BoxCar>(c: C, d: C::Color) {
    |                             ^^^^^^^^ ambiguous associated type `Color`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn paint<C:BoxCar>(c: C, d: <C as Vehicle>::Color) {
    |                             ~~~~~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | fn paint<C:BoxCar>(c: C, d: <C as Box>::Color) {
    |                             ~~~~~~~~~~~~

diff --git a/tests/ui/associated-types/associated-types-in-ambiguous-context.stderr b/tests/ui/associated-types/associated-types-in-ambiguous-context.stderr
@@ -13,15 +13,15 @@ error[E0223]: ambiguous associated type
   --> $DIR/associated-types-in-ambiguous-context.rs:22:17
    |
 LL | trait Foo where Foo::Assoc: Bar {
-   |                 ^^^^^^^^^^ help: use the fully-qualified path: `<Self as Foo>::Assoc`
+   |                 ^^^^^^^^^^ help: use fully-qualified syntax: `<Self as Foo>::Assoc`
 
 error[E0223]: ambiguous associated type
   --> $DIR/associated-types-in-ambiguous-context.rs:27:10
    |
 LL | type X = std::ops::Deref::Target;
    |          ^^^^^^^^^^^^^^^^^^^^^^^
    |
-help: use the fully-qualified path
+help: use fully-qualified syntax
    |
 LL | type X = <CString as Deref>::Target;
    |          ~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -37,7 +37,7 @@ error[E0223]: ambiguous associated type
   --> $DIR/associated-types-in-ambiguous-context.rs:13:23
    |
 LL |     fn grab(&self) -> Grab::Value;
-   |                       ^^^^^^^^^^^ help: use the fully-qualified path: `<Self as Grab>::Value`
+   |                       ^^^^^^^^^^^ help: use fully-qualified syntax: `<Self as Grab>::Value`
 
 error[E0223]: ambiguous associated type
   --> $DIR/associated-types-in-ambiguous-context.rs:16:22

diff --git a/tests/ui/associated-types/associated-types-path-1.stderr b/tests/ui/associated-types/associated-types-path-1.stderr
@@ -16,11 +16,11 @@ LL |     type A;
 LL | pub fn f2<T: Foo + Bar>(a: T, x: T::A) {}
    |                                  ^^^^ ambiguous associated type `A`
    |
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | pub fn f2<T: Foo + Bar>(a: T, x: <T as Bar>::A) {}
    |                                  ~~~~~~~~~~~~
-help: use fully qualified syntax to disambiguate
+help: use fully-qualified syntax to disambiguate
    |
 LL | pub fn f2<T: Foo + Bar>(a: T, x: <T as Foo>::A) {}
    |                                  ~~~~~~~~~~~~