Remove mutation check

Author: iSwapna

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -470,7 +470,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             );
         }
 
-        let mut internal_mutation_in_method = false;
         if let SelfSource::MethodCall(rcvr_expr) = source {
             self.suggest_fn_call(&mut err, rcvr_expr, rcvr_ty, |output_ty| {
                 let call_expr =
@@ -484,7 +483,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
                 probe.is_ok()
             });
-            internal_mutation_in_method = true;
             self.note_internal_mutation_in_method(
                 &mut err,
                 rcvr_expr,
@@ -1242,13 +1240,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         }
         // Only if an appropriate error source is not found, check method chain for possible candiates
-        let error_source_not_found =
-            unsatisfied_predicates.is_empty() && !internal_mutation_in_method;
+        let error_source_not_found = unsatisfied_predicates.is_empty();         
         if error_source_not_found && let Mode::MethodCall = mode && let SelfSource::MethodCall(mut rcvr_expr) = source {
         while let hir::ExprKind::MethodCall(_path_segment, parent_expr, _args, method_span) =
         rcvr_expr.kind
             {
-                print!("rcvr_expr {:?}", rcvr_expr);
                 let prev_ty = self.resolve_vars_if_possible(
                     self.typeck_results
                         .borrow()
@@ -1262,13 +1258,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     IsSuggestion(true),
                     prev_ty,
                     rcvr_expr.hir_id,
-                    ProbeScope::AllTraits,) {
+                    ProbeScope::TraitsInScope,) {
                         err.span_label(method_span, format!("{item_kind} `{item_name}` is available on `{prev_ty}`"));
                     }
                     rcvr_expr = parent_expr;
 
             }
         }
+    
         self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_name, expected);
         return Some(err);
     }

tests/ui/structs/method-chain-expression-failure.stderr

@@ -5,7 +5,9 @@ LL | struct D;
    | -------- method `foo` not found for this struct
 ...
 LL |     A.b().c().d().foo();
-   |                   ^^^ method not found in `D`
+   |           ---     ^^^ method not found in `D`
+   |           |
+   |           method `foo` is available on `&B`
 
 error: aborting due to previous error
 

tests/ui/suggestions/chain-method-call-mutation-in-place.stderr

@@ -18,7 +18,10 @@ error[E0599]: no method named `sort` found for unit type `()` in the current sco
   --> $DIR/chain-method-call-mutation-in-place.rs:3:72
    |
 LL |     vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
-   |                                                                        ^^^^ method not found in `()`
+   |                   -----------                       ------------------ ^^^^ method not found in `()`
+   |                   |                                 |
+   |                   |                                 method `sort` is available on `&mut [i32]`
+   |                   method `sort` is available on `Vec<i32>`
    |
 note: method `sort_by_key` modifies its receiver in-place, it is not meant to be used in method chains.
   --> $DIR/chain-method-call-mutation-in-place.rs:3:53