Change labeled statement to use visitSubGraph for its body instead of marking its "exit block" spec…

frog/leg/ssa/builder.dart

 // Copyright (c) 2012, 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.
 
 class Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2216 matching lines @@
       return;
     }
     LocalsHandler beforeLocals = new LocalsHandler.from(localsHandler);
     assert(targetElement.isBreakTarget);
     BreakHandler handler = new BreakHandler(this, targetElement);
     // Introduce a new basic block.
     HBasicBlock entryBlock = graph.addNewBlock();
     goto(current, entryBlock);
     open(entryBlock);
     visit(body);
+    SubGraph bodyGraph = new SubGraph(entryBlock, lastOpenedBlock);
     if (isAborted()) {
       compiler.unimplemented(
           "SsaBuilder for labeled statement with aborting body", node: node);
     }
 
     HBasicBlock joinBlock = graph.addNewBlock();
     List<LocalsHandler> breakLocals = <LocalsHandler>[];
     handler.forEachBreak((HBreak breakInstruction, LocalsHandler locals) {
       breakInstruction.block.addSuccessor(joinBlock);
       breakLocals.add(locals);
     });
     bool hasBreak = breakLocals.length > 0;
     if (!isAborted()) {
       goto(current, joinBlock);
       breakLocals.add(localsHandler);
     }
     open(joinBlock);
     localsHandler = beforeLocals.mergeMultiple(breakLocals, joinBlock);
 
     if (hasBreak) {
       // There was at least one reachable break, so the label is needed.
       HLabeledBlockInformation blockInfo =
-          new HLabeledBlockInformation(entryBlock, current,
-                                       handler.labels());
+          new HLabeledBlockInformation(bodyGraph, joinBlock, handler.labels());
       handler.close();

[ngeoffray, 2012/03/05 14:12:48]

Any reason why the close is between the creation and setter of the blockInfo?

[Lasse Reichstein Nielsen, 2012/03/05 14:16:49]

No. It just needs to be after handler.labels() is called.
I'll move it further down.

-      // Mark both entry and exit with the information. You can
-      // tell which one is which by comparing with blockInfo.start/end.
-      // It doesn't matter which merge block we use, they won't be generating
-      // any code, so put the end-marker on the last join block.
       entryBlock.labeledBlockInformation = blockInfo;
-      current.labeledBlockInformation = blockInfo;
     }
   }
 
   visitLiteralMap(LiteralMap node) {
     generateUnimplemented('literal map not implemented', isExpression: true);
   }
 
   visitLiteralMapEntry(LiteralMapEntry node) {
     compiler.unimplemented('SsaBuilder.visitLiteralMapEntry', node: node);
   }
@@ skipping 121 matching lines @@
     // Normally, we would call [close] here. However, then we hit
     // another unimplemented feature: aborting loop body. Simply
     // calling [add] does not work as it asserts that the instruction
     // isn't a control flow instruction. So we inline parts of [add].
     current.addAfter(current.last, new HThrow(message));
     if (isExpression) {
       stack.add(graph.addNewLiteralNull());
     }
   }
 }