Auto merge of #2738 - RalfJung:rustup, r=RalfJung

Rustup

3 files changed, 28 insertions, 10 deletions

diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index f4a6a08df1c..cf635996268 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -576,7 +576,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 // Ensure there is at most one `self` in the list
                 let self_spans = items
                     .iter()
-                    .filter_map(|&(ref use_tree, _)| {
+                    .filter_map(|(use_tree, _)| {
                         if let ast::UseTreeKind::Simple(..) = use_tree.kind {
                             if use_tree.ident().name == kw::SelfLower {
                                 return Some(use_tree.span);
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 49bbe37ee43..600308b6508 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -277,11 +277,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 let override_suggestion =
                     if ["true", "false"].contains(&item_str.to_string().to_lowercase().as_str()) {
                         let item_typo = item_str.to_string().to_lowercase();
-                        Some((
-                            item_span,
-                            "you may want to use a bool value instead",
-                            format!("{}", item_typo),
-                        ))
+                        Some((item_span, "you may want to use a bool value instead", item_typo))
                     // FIXME(vincenzopalazzo): make the check smarter,
                     // and maybe expand with levenshtein distance checks
                     } else if item_str.as_str() == "printf" {
@@ -2324,7 +2320,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                         let message = format!("consider introducing lifetime `{}` here", name);
                         should_continue = suggest(err, false, span, &message, sugg);
                     } else {
-                        let message = format!("consider introducing a named lifetime parameter");
+                        let message = "consider introducing a named lifetime parameter";
                         should_continue = suggest(err, false, span, &message, sugg);
                     }
                 }
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 24e4b5bdd3f..2182b736937 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -1491,7 +1491,7 @@ impl<'a> Resolver<'a> {
             label_res_map: self.label_res_map.clone(),
             lifetimes_res_map: self.lifetimes_res_map.clone(),
             extra_lifetime_params_map: self.extra_lifetime_params_map.clone(),
-            next_node_id: self.next_node_id.clone(),
+            next_node_id: self.next_node_id,
             node_id_to_def_id: self.node_id_to_def_id.clone(),
             def_id_to_node_id: self.def_id_to_node_id.clone(),
             trait_map: self.trait_map.clone(),
@@ -1686,6 +1686,24 @@ impl<'a> Resolver<'a> {
             .or_insert_with(|| self.arenas.alloc_name_resolution())
     }
 
+    /// Test if AmbiguityError ambi is any identical to any one inside ambiguity_errors
+    fn matches_previous_ambiguity_error(&mut self, ambi: &AmbiguityError<'_>) -> bool {
+        for ambiguity_error in &self.ambiguity_errors {
+            // if the span location and ident as well as its span are the same
+            if ambiguity_error.kind == ambi.kind
+                && ambiguity_error.ident == ambi.ident
+                && ambiguity_error.ident.span == ambi.ident.span
+                && ambiguity_error.b1.span == ambi.b1.span
+                && ambiguity_error.b2.span == ambi.b2.span
+                && ambiguity_error.misc1 == ambi.misc1
+                && ambiguity_error.misc2 == ambi.misc2
+            {
+                return true;
+            }
+        }
+        false
+    }
+
     fn record_use(
         &mut self,
         ident: Ident,
@@ -1693,14 +1711,18 @@ impl<'a> Resolver<'a> {
         is_lexical_scope: bool,
     ) {
         if let Some((b2, kind)) = used_binding.ambiguity {
-            self.ambiguity_errors.push(AmbiguityError {
+            let ambiguity_error = AmbiguityError {
                 kind,
                 ident,
                 b1: used_binding,
                 b2,
                 misc1: AmbiguityErrorMisc::None,
                 misc2: AmbiguityErrorMisc::None,
-            });
+            };
+            if !self.matches_previous_ambiguity_error(&ambiguity_error) {
+                // avoid dumplicated span information to be emitt out
+                self.ambiguity_errors.push(ambiguity_error);
+            }
         }
         if let NameBindingKind::Import { import, binding, ref used } = used_binding.kind {
             // Avoid marking `extern crate` items that refer to a name from extern prelude,