allow customising ty::TraitRef's printing behavior

fix clippy

allow customising ty::TraitRef's printing behavior

fix clippy

stylistic fix

4 files changed, 14 insertions, 12 deletions

diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index 6e723cdc999..90db1fe3195 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -737,7 +737,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                         let is_try = self.tcx.sess.source_map().span_to_snippet(span)
                             .map(|s| &s == "?")
                             .unwrap_or(false);
-                        let is_from = format!("{}", trait_ref).starts_with("std::convert::From<");
+                        let is_from =
+                            format!("{}", trait_ref.print_only_trait_path())
+                            .starts_with("std::convert::From<");
                         let (message, note) = if is_try && is_from {
                             (Some(format!(
                                 "`?` couldn't convert the error to `{}`",
@@ -768,7 +770,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                                 format!(
                                     "{}the trait `{}` is not implemented for `{}`",
                                     pre_message,
-                                    trait_ref,
+                                    trait_ref.print_only_trait_path(),
                                     trait_ref.self_ty(),
                                 )
                             };
@@ -1189,7 +1191,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 if param_ty => {
                     // Missing generic type parameter bound.
                     let param_name = self_ty.to_string();
-                    let constraint = trait_ref.to_string();
+                    let constraint = trait_ref.print_only_trait_path().to_string();
                     if suggest_constraining_type_param(
                         generics,
                         &mut err,
@@ -1416,7 +1418,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     let msg = format!(
                         "the trait bound `{}: {}` is not satisfied",
                         found,
-                        obligation.parent_trait_ref.skip_binder(),
+                        obligation.parent_trait_ref.skip_binder().print_only_trait_path(),
                     );
                     if has_custom_message {
                         err.note(&msg);
@@ -1430,7 +1432,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     }
                     err.span_label(span, &format!(
                         "expected an implementor of trait `{}`",
-                        obligation.parent_trait_ref.skip_binder(),
+                        obligation.parent_trait_ref.skip_binder().print_only_trait_path(),
                     ));
                     err.span_suggestion(
                         span,
@@ -1562,7 +1564,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     } else {
                         err.note(&format!(
                             "`{}` is implemented for `{:?}`, but not for `{:?}`",
-                            trait_ref,
+                            trait_ref.print_only_trait_path(),
                             trait_type,
                             trait_ref.skip_binder().self_ty(),
                         ));
@@ -2226,7 +2228,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
             err.span_note(span, &format!(
                 "future does not implement `{}` as this value is used across an await",
-                trait_ref,
+                trait_ref.print_only_trait_path(),
             ));
 
             // Add a note for the item obligation that remains - normally a note pointing to the
@@ -2409,7 +2411,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 let parent_trait_ref = self.resolve_vars_if_possible(&data.parent_trait_ref);
                 err.note(
                     &format!("required because of the requirements on the impl of `{}` for `{}`",
-                             parent_trait_ref,
+                             parent_trait_ref.print_only_trait_path(),
                              parent_trait_ref.skip_binder().self_ty()));
                 let parent_predicate = parent_trait_ref.to_predicate();
                 self.note_obligation_cause_code(err,
diff --git a/src/librustc/traits/select.rs b/src/librustc/traits/select.rs
index 283fa56d11f..5f324527a27 100644
--- a/src/librustc/traits/select.rs
+++ b/src/librustc/traits/select.rs
@@ -1044,7 +1044,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         let trait_ref = stack.obligation.predicate.skip_binder().trait_ref;
                         let self_ty = trait_ref.self_ty();
                         let cause = IntercrateAmbiguityCause::DownstreamCrate {
-                            trait_desc: trait_ref.to_string(),
+                            trait_desc: trait_ref.print_only_trait_path().to_string(),
                             self_desc: if self_ty.has_concrete_skeleton() {
                                 Some(self_ty.to_string())
                             } else {
@@ -1386,7 +1386,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     if !candidate_set.ambiguous && no_candidates_apply {
                         let trait_ref = stack.obligation.predicate.skip_binder().trait_ref;
                         let self_ty = trait_ref.self_ty();
-                        let trait_desc = trait_ref.to_string();
+                        let trait_desc = trait_ref.print_only_trait_path().to_string();
                         let self_desc = if self_ty.has_concrete_skeleton() {
                             Some(self_ty.to_string())
                         } else {
diff --git a/src/librustc/traits/specialize/mod.rs b/src/librustc/traits/specialize/mod.rs
index 475037f54ba..88a2db3dc62 100644
--- a/src/librustc/traits/specialize/mod.rs
+++ b/src/librustc/traits/specialize/mod.rs
@@ -417,7 +417,7 @@ fn to_pretty_impl_header(tcx: TyCtxt<'_>, impl_def_id: DefId) -> Option<String>
         w.push('>');
     }
 
-    write!(w, " {} for {}", trait_ref, tcx.type_of(impl_def_id)).unwrap();
+    write!(w, " {} for {}", trait_ref.print_only_trait_path(), tcx.type_of(impl_def_id)).unwrap();
 
     // The predicates will contain default bounds like `T: Sized`. We need to
     // remove these bounds, and add `T: ?Sized` to any untouched type parameters.
diff --git a/src/librustc/traits/specialize/specialization_graph.rs b/src/librustc/traits/specialize/specialization_graph.rs
index d945c756f66..b8ddf6078bd 100644
--- a/src/librustc/traits/specialize/specialization_graph.rs
+++ b/src/librustc/traits/specialize/specialization_graph.rs
@@ -146,7 +146,7 @@ impl<'tcx> Children {
                 let self_ty = trait_ref.self_ty();
                 OverlapError {
                     with_impl: possible_sibling,
-                    trait_desc: trait_ref.to_string(),
+                    trait_desc: trait_ref.print_only_trait_path().to_string(),
                     // Only report the `Self` type if it has at least
                     // some outer concrete shell; otherwise, it's
                     // not adding much information.