fix: wrong trait import suggestion for T:

[rust.git] / compiler / rustc_typeck / src / check / method / suggest.rs

diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index c2cb233f5b84cfa142a433db644762a95b1ba418..e6560ca4d9b90e7827e30827220cb075ade931cc 100644 (file)
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -5,6 +5,7 @@
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{
     pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed,
+    MultiSpan,
 };
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -17,7 +18,7 @@
 use rustc_middle::ty::ToPolyTraitRef;
 use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeFoldable};
 use rustc_span::symbol::{kw, sym, Ident};
-use rustc_span::{lev_distance, source_map, ExpnKind, FileName, MacroKind, MultiSpan, Span};
+use rustc_span::{lev_distance, source_map, ExpnKind, FileName, MacroKind, Span};
 use rustc_trait_selection::traits::error_reporting::on_unimplemented::InferCtxtExt as _;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::{
@@ -1879,9 +1880,15 @@ fn suggest_traits_to_import(
                                 };
                             let sp = hir.span(id);
                             let sp = if let Some(first_bound) = has_bounds {
-                                // `sp` only covers `T`, change it so that it covers
-                                // `T:` when appropriate
                                 sp.until(first_bound.span())
+                            } else if let Some(colon_sp) =
+                                // If the generic param is declared with a colon but without bounds:
+                                // fn foo<T:>(t: T) { ... }
+                                param.colon_span_for_suggestions(
+                                    self.inh.tcx.sess.source_map(),
+                                )
+                            {
+                                sp.to(colon_sp)
                             } else {
                                 sp
                             };