Account for closures

Author: estebank

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -167,7 +167,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 );
             }
 
-            self.add_moved_or_invoked_closure_note(location, used_place, &mut err);
+            let closure = self.add_moved_or_invoked_closure_note(location, used_place, &mut err);
 
             let mut is_loop_move = false;
             let mut in_pattern = false;
@@ -193,7 +193,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 }
 
                 if !seen_spans.contains(&move_span) {
-                    self.suggest_ref_or_clone(mpi, move_span, &mut err, &mut in_pattern);
+                    if !closure {
+                        self.suggest_ref_or_clone(mpi, move_span, &mut err, &mut in_pattern);
+                    }
 
                     self.explain_captures(
                         &mut err,

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -70,7 +70,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         location: Location,
         place: PlaceRef<'tcx>,
         diag: &mut Diagnostic,
-    ) {
+    ) -> bool {
         debug!("add_moved_or_invoked_closure_note: location={:?} place={:?}", location, place);
         let mut target = place.local_or_deref_local();
         for stmt in &self.body[location.block].statements[location.statement_index..] {
@@ -106,7 +106,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         {
                             place.local_or_deref_local().unwrap()
                         }
-                        _ => return,
+                        _ => return false,
                     };
 
                     debug!("add_moved_or_invoked_closure_note: closure={:?}", closure);
@@ -125,7 +125,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                     ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                                 ),
                             );
-                            return;
+                            return true;
                         }
                     }
                 }
@@ -149,9 +149,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                         ),
                     );
+                    return true;
                 }
             }
         }
+        false
     }
 
     /// End-user visible description of `place` if one can be found.

src/test/ui/closure_context/issue-42065.stderr

@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     debug_dump_dict();
    |     ^^^^^^^^^^^^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     debug_dump_dict.clone()();
-   |                    ++++++++
 
 error: aborting due to previous error
 

src/test/ui/moves/borrow-closures-instead-of-move.stderr

@@ -58,13 +58,6 @@ note: closure cannot be moved more than once as it is not `Copy` due to moving t
    |
 LL |         x += 1;
    |         ^
-note: consider changing this parameter type in function `takes_fnonce` to borrow instead if owning the value isn't necessary
-  --> $DIR/borrow-closures-instead-of-move.rs:34:20
-   |
-LL | fn takes_fnonce(_: impl FnOnce()) {}
-   |    ------------    ^^^^^^^^^^^^^ this parameter takes ownership of the value
-   |    |
-   |    in this function
 help: consider mutably borrowing `closure`
    |
 LL |     takes_fnonce(&mut closure);

src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr

@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     tick.clone()();
-   |         ++++++++
 
 error: aborting due to previous error
 

src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr

@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     tick.clone()();
-   |         ++++++++
 
 error: aborting due to previous error