Rework print_disambiguation_help

Author: compiler-errors

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -34,7 +34,7 @@ use rustc_middle::ty::{self, GenericArgKind, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::DefIdSet;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Symbol;
-use rustc_span::{edit_distance, source_map, ExpnKind, FileName, MacroKind, Span};
+use rustc_span::{edit_distance, ExpnKind, FileName, MacroKind, Span};
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::OnUnimplementedNote;
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::TypeErrCtxtExt as _;
@@ -1320,39 +1320,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  }
  if let Some(sugg_span) = sugg_span
  && let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did)
- {
- let path = self.tcx.def_path_str(trait_ref.skip_binder().def_id);
-
- let ty = match item.kind {
- ty::AssocKind::Const | ty::AssocKind::Type => impl_ty,
- ty::AssocKind::Fn => self
- .tcx
- .fn_sig(item.def_id)
- .instantiate_identity()
- .inputs()
- .skip_binder()
- .get(0)
- .filter(|ty| ty.is_ref() && !rcvr_ty.is_ref())
- .copied()
- .unwrap_or(rcvr_ty),
- };
- if let Some(sugg) = print_disambiguation_help(
- item_name,
- args,
- self_source,
+ && let Some(sugg) = print_disambiguation_help(
+ self.tcx,
  err,
- path,
- ty,
- Some(impl_ty),
- item.kind,
- self.tcx.def_kind_descr(item.kind.as_def_kind(), item.def_id),
- sugg_span,
+ self_source,
+ args,
+ trait_ref.instantiate(
+  self.tcx,
+  self.fresh_args_for_item(sugg_span, impl_did)
+ ).with_self_ty(self.tcx, rcvr_ty),
  idx,
- self.tcx.sess.source_map(),
- item.fn_has_self_parameter,
- ) {
-  suggs.push(sugg);
- }
+ sugg_span,
+ item,
+ )
+ {
+ suggs.push(sugg);
  }
  }
  CandidateSource::Trait(trait_did) => {
@@ -1374,25 +1356,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  err.span_note(item_span, msg);
  None
  };
- if let Some(sugg_span) = sugg_span {
- let path = self.tcx.def_path_str(trait_did);
- if let Some(sugg) = print_disambiguation_help(
- item_name,
- args,
- self_source,
+ if let Some(sugg_span) = sugg_span
+ && let Some(sugg) = print_disambiguation_help(
+ self.tcx,
  err,
- path,
- rcvr_ty,
- None,
- item.kind,
- self.tcx.def_kind_descr(item.kind.as_def_kind(), item.def_id),
- sugg_span,
+ self_source,
+ args,
+ ty::TraitRef::new(
+ self.tcx,
+ trait_did,
+ self.fresh_args_for_item(sugg_span, trait_did)
+ ).with_self_ty(self.tcx, rcvr_ty),
  idx,
- self.tcx.sess.source_map(),
- item.fn_has_self_parameter,
- ) {
-  suggs.push(sugg);
- }
+ sugg_span,
+ item,
+ )
+ {
+ suggs.push(sugg);
  }
  }
  }
@@ -3263,59 +3243,59 @@ pub fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> {
 }
 
 fn print_disambiguation_help<'tcx>(
- item_name: Ident,
- args: Option<&'tcx [hir::Expr<'tcx>]>,
- source: SelfSource<'tcx>,
+ tcx: TyCtxt<'tcx>,
  err: &mut Diagnostic,
- trait_name: String,
- rcvr_ty: Ty<'_>,
- impl_self_ty: Option<Ty<'_>>,
- kind: ty::AssocKind,
- def_kind_descr: &'static str,
+ source: SelfSource<'tcx>,
+ args: Option<&'tcx [hir::Expr<'tcx>]>,
+ trait_ref: ty::TraitRef<'tcx>,
+ candidate_idx: Option<usize>,
  span: Span,
- candidate: Option<usize>,
- source_map: &source_map::SourceMap,
- fn_has_self_parameter: bool,
+ item: ty::AssocItem,
 ) -> Option<String> {
+ let trait_ref = if item.fn_has_self_parameter {
+ trait_ref.print_only_trait_name().to_string()
+ } else {
+ format!("<{} as {}>", trait_ref.args[0], trait_ref.print_only_trait_name())
+ };
  Some(
- if matches!(kind, ty::AssocKind::Fn)
+ if matches!(item.kind, ty::AssocKind::Fn)
  && let SelfSource::MethodCall(receiver) = source
  && let Some(args) = args
  {
+ let def_kind_descr = tcx.def_kind_descr(item.kind.as_def_kind(), item.def_id);
+ let item_name = item.ident(tcx);
+ let rcvr_ref = tcx.fn_sig(item.def_id).skip_binder().skip_binder().inputs()[0]
+ .ref_mutability()
+ .map_or("", |mutbl| mutbl.ref_prefix_str());
  let args = format!(
  "({}{})",
- rcvr_ty.ref_mutability().map_or("", |mutbl| mutbl.ref_prefix_str()),
+ rcvr_ref,
  std::iter::once(receiver)
  .chain(args.iter())
- .map(|arg| source_map
+ .map(|arg| tcx
+ .sess
+ .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
- };
  err.span_suggestion_verbose(
  span,
  format!(
  "disambiguate the {def_kind_descr} for {}",
- if let Some(candidate) = candidate {
+ if let Some(candidate) = candidate_idx {
  format!("candidate #{candidate}")
  } else {
  "the candidate".to_string()
  },
  ),
- format!("{trait_name}::{item_name}{args}"),
+ format!("{trait_ref}::{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}::")
+ format!("{trait_ref}::")
  },
  )
 }

tests/ui/methods/disambiguate-multiple-blanket-impl.stderr

@@ -29,10 +29,10 @@ LL | fn foo(&self) {}
  | ^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | <T as A>::foo(&s);
- | ~~~~~~~~~~
-LL | <T as B>::foo(&s);
- | ~~~~~~~~~~
+LL | A::foo(&s);
+ | ~~~
+LL | B::foo(&s);
+ | ~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/disambiguate-multiple-blanket-impl.rs:33:8
@@ -52,9 +52,9 @@ LL | const CONST: usize = 2;
  | ^^^^^^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | <T as A>::CONST;
+LL | <S as A>::CONST;
  | ~~~~~~~~~~
-LL | <T as B>::CONST;
+LL | <S as B>::CONST;
  | ~~~~~~~~~~
 
 error: aborting due to 3 previous errors

tests/ui/methods/disambiguate-multiple-impl.stderr

@@ -29,10 +29,10 @@ LL | fn foo(&self) {}
  | ^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | <S as A>::foo(&s);
- | ~~~~~~~~~~
-LL | <S as B>::foo(&s);
- | ~~~~~~~~~~
+LL | A::foo(&s);
+ | ~~~
+LL | B::foo(&s);
+ | ~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/disambiguate-multiple-impl.rs:34:16

tests/ui/methods/disambiguate-multiple-trait-2.stderr

@@ -37,12 +37,12 @@ LL | fn foo(&self);
  | ^^^^^^^^^^^^^^
 help: disambiguate the method for candidate #1
  |
-LL | A::foo(t);
- | ~~~~~~~~~
+LL | A::foo(&t);
+ | ~~~~~~~~~~
 help: disambiguate the method for candidate #2
  |
-LL | B::foo(t);
- | ~~~~~~~~~
+LL | B::foo(&t);
+ | ~~~~~~~~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/disambiguate-multiple-trait-2.rs:20:16
@@ -62,10 +62,10 @@ LL | const CONST: usize;
  | ^^^^^^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | let _ = A::CONST;
- | ~~~
-LL | let _ = B::CONST;
- | ~~~
+LL | let _ = <T as A>::CONST;
+ | ~~~~~~~~~~
+LL | let _ = <T as B>::CONST;
+ | ~~~~~~~~~~
 
 error[E0223]: ambiguous associated type
  --> $DIR/disambiguate-multiple-trait-2.rs:52:12
@@ -98,10 +98,10 @@ LL | fn foo(&self) {}
  | ^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | <T as A>::foo(&s);
- | ~~~~~~~~~~
-LL | <T as B>::foo(&s);
- | ~~~~~~~~~~
+LL | A::foo(&s);
+ | ~~~
+LL | B::foo(&s);
+ | ~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/disambiguate-multiple-trait-2.rs:49:16
@@ -121,9 +121,9 @@ LL | const CONST: usize = 1;
  | ^^^^^^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | let _ = <T as A>::CONST;
+LL | let _ = <S as A>::CONST;
  | ~~~~~~~~~~
-LL | let _ = <T as B>::CONST;
+LL | let _ = <S as B>::CONST;
  | ~~~~~~~~~~
 
 error: aborting due to 6 previous errors

tests/ui/methods/disambiguate-multiple-trait.stderr

@@ -29,10 +29,10 @@ LL | fn foo(&self) {}
  | ^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | <T as A>::foo(&s);
- | ~~~~~~~~~~
-LL | <T as B>::foo(&s);
- | ~~~~~~~~~~
+LL | A::foo(&s);
+ | ~~~
+LL | B::foo(&s);
+ | ~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/disambiguate-multiple-trait.rs:27:16
@@ -52,9 +52,9 @@ LL | const CONST: usize = 2;
  | ^^^^^^^^^^^^^^^^^^
 help: use fully-qualified syntax to disambiguate
  |
-LL | let _ = <T as A>::CONST;
+LL | let _ = <S as A>::CONST;
  | ~~~~~~~~~~
-LL | let _ = <T as B>::CONST;
+LL | let _ = <S as B>::CONST;
  | ~~~~~~~~~~
 
 error: aborting due to 3 previous errors

tests/ui/methods/method-ambig-two-traits-from-bounds.stderr

@@ -16,12 +16,12 @@ LL | trait B { fn foo(&self); }
  | ^^^^^^^^^^^^^^
 help: disambiguate the method for candidate #1
  |
-LL | A::foo(t);
- | ~~~~~~~~~
+LL | A::foo(&t);
+ | ~~~~~~~~~~
 help: disambiguate the method for candidate #2
  |
-LL | B::foo(t);
- | ~~~~~~~~~
+LL | B::foo(&t);
+ | ~~~~~~~~~~
 
 error: aborting due to previous error
 

tests/ui/methods/method-deref-to-same-trait-object-with-separate-params.stderr

@@ -54,8 +54,8 @@ LL | let z = NuisanceFoo::foo(x);
  | ~~~~~~~~~~~~~~~~~~~
 help: disambiguate the method for candidate #3
  |
-LL | let z = FinalFoo::foo(x);
- | ~~~~~~~~~~~~~~~~
+LL | let z = FinalFoo::foo(&x);
+ | ~~~~~~~~~~~~~~~~~
 
 error[E0308]: mismatched types
  --> $DIR/method-deref-to-same-trait-object-with-separate-params.rs:139:24

tests/ui/span/issue-37767.stderr

@@ -16,12 +16,12 @@ LL | fn foo(&mut self) {}
  | ^^^^^^^^^^^^^^^^^
 help: disambiguate the method for candidate #1
  |
-LL | A::foo(&a)
- | ~~~~~~~~~~
+LL | A::foo(&mut a)
+ | ~~~~~~~~~~~~~~
 help: disambiguate the method for candidate #2
  |
-LL | B::foo(&a)
- | ~~~~~~~~~~
+LL | B::foo(&mut a)
+ | ~~~~~~~~~~~~~~
 
 error[E0034]: multiple applicable items in scope
  --> $DIR/issue-37767.rs:22:7