Reject non-local jumps.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.body_builder;
 
 import '../parser/parser.dart' show FormalParameterType, optional;
 
 import '../parser/error_kind.dart' show ErrorKind;
 
@@ skipping 253 matching lines @@
     push(switchScope ?? NullValue.SwitchScope);
     switchScope = scope;
   }
 
   void exitSwitchScope() {
     switchScope = pop();
   }
 
   @override
   JumpTarget createJumpTarget(JumpTargetKind kind, int charOffset) {
-    return new JumpTarget(kind, member, charOffset);
+    return new JumpTarget(kind, functionNestingLevel, member, charOffset);
   }
 
   @override
   void endMetadata(Token beginToken, Token periodBeforeName, Token endToken) {
     debugEvent("Metadata");
     pop(); // Arguments.
     popIfNotNull(periodBeforeName); // Postfix.
     pop(); // Type arguments.
     pop(); // Expression or type name (depends on arguments).
     // TODO(ahe): Implement metadata on local declarations.
@@ skipping 1633 matching lines @@
     debugEvent("Label");
     Identifier identifier = pop();
     push(new Label(identifier.name));
   }
 
   @override
   void beginLabeledStatement(Token token, int labelCount) {
     debugEvent("beginLabeledStatement");
     List<Label> labels = popList(labelCount);
     enterLocalScope();
-    LabelTarget target = new LabelTarget(member, token.charOffset);
+    LabelTarget target =
+        new LabelTarget(member, functionNestingLevel, token.charOffset);
     for (Label label in labels) {
       scope.declareLabel(label.name, target);
     }
     push(target);
   }
 
   @override
   void endLabeledStatement(int labelCount) {
     debugEvent("LabeledStatement");
     Statement statement = popStatement();
@@ skipping 171 matching lines @@
       target = scope.lookupLabel(identifier.name);
     }
     if (target == null && name == null) {
       push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
           "No target of break.", breakKeyword.charOffset));
     } else if (target == null ||
         target is! JumpTarget ||
         !target.isBreakTarget) {
       push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
           "Can't break to '$name'.", breakKeyword.next.charOffset));
+    } else if (target.functionNestingLevel != functionNestingLevel) {
+      push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
+          "Can't break to '$name' in a different function.",
+          breakKeyword.next.charOffset));
     } else {
       BreakStatement statement = new BreakStatement(null)
         ..fileOffset = breakKeyword.charOffset;
       target.addBreak(statement);
       push(statement);
     }
   }
 
   @override
   void handleContinueStatement(
@@ skipping 25 matching lines @@
         push(statement);
         return;
       }
     }
     if (target == null) {
       push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
           "No target of continue.", continueKeyword.charOffset));
     } else if (!target.isContinueTarget) {
       push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
           "Can't continue at '$name'.", continueKeyword.next.charOffset));
+    } else if (target.functionNestingLevel != functionNestingLevel) {
+      push(compileTimeErrorInLoopOrSwitch = buildCompileTimeErrorStatement(
+          "Can't continue at '$name' in a different function.",
+          continueKeyword.next.charOffset));
     } else {
       BreakStatement statement = new BreakStatement(null)
         ..fileOffset = continueKeyword.charOffset;
       target.addContinue(statement);
       push(statement);
     }
   }
 
   @override
   void endTypeVariable(Token token, Token extendsOrSuper) {
@@ skipping 335 matching lines @@
     return accessor.buildPostfixIncrement(binaryOperator, charOffset,
         voidContext: true, interfaceTarget: interfaceTarget);
   }
 }
 
 class JumpTarget extends Builder {
   final List<Statement> users = <Statement>[];
 
   final JumpTargetKind kind;
 
-  JumpTarget(this.kind, MemberBuilder member, int charOffset)
+  final int functionNestingLevel;
+
+  JumpTarget(this.kind, this.functionNestingLevel, MemberBuilder member,
+      int charOffset)
       : super(member, charOffset, member.fileUri);
 
   bool get isBreakTarget => kind == JumpTargetKind.Break;
 
   bool get isContinueTarget => kind == JumpTargetKind.Continue;
 
   bool get isGotoTarget => kind == JumpTargetKind.Goto;
 
   bool get hasUsers => users.isNotEmpty;
 
@@ skipping 35 matching lines @@
     }
     users.clear();
   }
 }
 
 class LabelTarget extends Builder implements JumpTarget {
   final JumpTarget breakTarget;
 
   final JumpTarget continueTarget;
 
-  LabelTarget(MemberBuilder member, int charOffset)
-      : breakTarget = new JumpTarget(JumpTargetKind.Break, member, charOffset),
-        continueTarget =
-            new JumpTarget(JumpTargetKind.Continue, member, charOffset),
+  final int functionNestingLevel;
+
+  LabelTarget(MemberBuilder member, this.functionNestingLevel, int charOffset)
+      : breakTarget = new JumpTarget(
+            JumpTargetKind.Break, functionNestingLevel, member, charOffset),
+        continueTarget = new JumpTarget(
+            JumpTargetKind.Continue, functionNestingLevel, member, charOffset),
         super(member, charOffset, member.fileUri);
 
   bool get hasUsers => breakTarget.hasUsers || continueTarget.hasUsers;
 
   List<Statement> get users => internalError("Unsupported operation.");
 
   JumpTargetKind get kind => internalError("Unsupported operation.");
 
   bool get isBreakTarget => true;
 
@@ skipping 131 matching lines @@
   } else if (node is PrefixBuilder) {
     return node.name;
   } else if (node is ThisAccessor) {
     return node.isSuper ? "super" : "this";
   } else if (node is BuilderAccessor) {
     return node.plainNameForRead;
   } else {
     return internalError("Unhandled: ${node.runtimeType}");
   }
 }