diff options
| -rw-r--r-- | src/librustc_mir/borrow_check/error_reporting.rs | 82 | ||||
| -rw-r--r-- | src/test/ui/not-copy-closure.nll.stderr | 6 |
2 files changed, 49 insertions, 39 deletions
diff --git a/src/librustc_mir/borrow_check/error_reporting.rs b/src/librustc_mir/borrow_check/error_reporting.rs index ad8abe16415..474e67ac11a 100644 --- a/src/librustc_mir/borrow_check/error_reporting.rs +++ b/src/librustc_mir/borrow_check/error_reporting.rs @@ -123,7 +123,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { Origin::Mir, ); - self.add_closure_invoked_twice_with_moved_variable_suggestion( + self.add_moved_or_invoked_closure_note( context.loc, used_place, &mut err, @@ -1329,7 +1329,8 @@ enum StorageDeadOrDrop<'tcx> { impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { - /// Adds a suggestion when a closure is invoked twice with a moved variable. + /// Adds a suggestion when a closure is invoked twice with a moved variable or when a closure + /// is moved after being invoked. /// /// ```text /// note: closure cannot be invoked more than once because it moves the variable `dict` out of @@ -1339,30 +1340,18 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { /// LL | for (key, value) in dict { /// | ^^^^ /// ``` - pub(super) fn add_closure_invoked_twice_with_moved_variable_suggestion( + pub(super) fn add_moved_or_invoked_closure_note( &self, location: Location, place: &Place<'tcx>, diag: &mut DiagnosticBuilder<'_>, ) { + debug!("add_moved_or_invoked_closure_note: location={:?} place={:?}", location, place); let mut target = place.local(); - debug!( - "add_closure_invoked_twice_with_moved_variable_suggestion: location={:?} place={:?} \ - target={:?}", - location, place, target, - ); for stmt in &self.mir[location.block].statements[location.statement_index..] { - debug!( - "add_closure_invoked_twice_with_moved_variable_suggestion: stmt={:?} \ - target={:?}", - stmt, target, - ); + debug!("add_moved_or_invoked_closure_note: stmt={:?} target={:?}", stmt, target); if let StatementKind::Assign(into, box Rvalue::Use(from)) = &stmt.kind { - debug!( - "add_closure_invoked_twice_with_moved_variable_suggestion: into={:?} \ - from={:?}", - into, from, - ); + debug!("add_fnonce_closure_note: into={:?} from={:?}", into, from); match from { Operand::Copy(ref place) | Operand::Move(ref place) if target == place.local() => @@ -1372,12 +1361,9 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { } } - + // Check if we are attempting to call a closure after it has been invoked. let terminator = self.mir[location.block].terminator(); - debug!( - "add_closure_invoked_twice_with_moved_variable_suggestion: terminator={:?}", - terminator, - ); + debug!("add_moved_or_invoked_closure_note: terminator={:?}", terminator); if let TerminatorKind::Call { func: Operand::Constant(box Constant { literal: ty::LazyConst::Evaluated(ty::Const { @@ -1389,7 +1375,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { args, .. } = &terminator.kind { - debug!("add_closure_invoked_twice_with_moved_variable_suggestion: id={:?}", id); + debug!("add_moved_or_invoked_closure_note: id={:?}", id); if self.infcx.tcx.parent(id) == self.infcx.tcx.lang_items().fn_once_trait() { let closure = match args.first() { Some(Operand::Copy(ref place)) | @@ -1397,33 +1383,51 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { place.local().unwrap(), _ => return, }; - debug!( - "add_closure_invoked_twice_with_moved_variable_suggestion: closure={:?}", - closure, - ); - if let ty::TyKind::Closure(did, _substs) = self.mir.local_decls[closure].ty.sty { - let node_id = match self.infcx.tcx.hir().as_local_node_id(did) { - Some(node_id) => node_id, - _ => return, - }; + debug!("add_moved_or_invoked_closure_note: closure={:?}", closure); + if let ty::TyKind::Closure(did, _) = self.mir.local_decls[closure].ty.sty { + let node_id = self.infcx.tcx.hir().as_local_node_id(did).unwrap(); let hir_id = self.infcx.tcx.hir().node_to_hir_id(node_id); - if let Some(( - span, name - )) = self.infcx.tcx.typeck_tables_of(did).closure_kind_origins().get(hir_id) { + if let Some((span, name)) = self.infcx.tcx.typeck_tables_of(did) + .closure_kind_origins() + .get(hir_id) + { diag.span_note( *span, &format!( - "closure cannot be invoked more than once because it \ - moves the variable `{}` out of its environment", - name, + "closure cannot be invoked more than once because it moves the \ + variable `{}` out of its environment", + name, ), ); + return; } } } } + + // Check if we are just moving a closure after it has been invoked. + if let Some(target) = target { + if let ty::TyKind::Closure(did, _) = self.mir.local_decls[target].ty.sty { + let node_id = self.infcx.tcx.hir().as_local_node_id(did).unwrap(); + let hir_id = self.infcx.tcx.hir().node_to_hir_id(node_id); + + if let Some((span, name)) = self.infcx.tcx.typeck_tables_of(did) + .closure_kind_origins() + .get(hir_id) + { + diag.span_note( + *span, + &format!( + "closure cannot be moved more than once as it is not `Copy` due to \ + moving the variable `{}` out of its environment", + name + ), + ); + } + } + } } /// End-user visible description of `place` if one can be found. If the diff --git a/src/test/ui/not-copy-closure.nll.stderr b/src/test/ui/not-copy-closure.nll.stderr index 2f295315a08..1a65bcf4473 100644 --- a/src/test/ui/not-copy-closure.nll.stderr +++ b/src/test/ui/not-copy-closure.nll.stderr @@ -5,6 +5,12 @@ LL | let b = hello; | ----- value moved here LL | let c = hello; //~ ERROR use of moved value: `hello` [E0382] | ^^^^^ value used here after move + | +note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `a` out of its environment + --> $DIR/not-copy-closure.rs:6:9 + | +LL | a += 1; + | ^ error: aborting due to previous error |