Support break and labeled statements.

frog/leg/ssa/nodes.dart

Index: frog/leg/ssa/nodes.dart
diff --git a/frog/leg/ssa/nodes.dart b/frog/leg/ssa/nodes.dart
index 0d7b4f125531863bd126db9ae7059388157619cf..0f7a144aa028939606ce04e4d9d55d334db0b521 100644
--- a/frog/leg/ssa/nodes.dart
+++ b/frog/leg/ssa/nodes.dart
@@ -11,6 +11,7 @@ interface HVisitor<R> {
   R visitBitXor(HBitXor node);
   R visitBoolify(HBoolify node);
   R visitBoundsCheck(HBoundsCheck node);
+  R visitBreak(HBreak node);
   R visitDivide(HDivide node);
   R visitEquals(HEquals node);
   R visitExit(HExit node);
@@ -135,9 +136,9 @@ class HGraph {
     return result;
   }
 
-  HBasicBlock addNewLoopHeaderBlock() {
+  HBasicBlock addNewLoopHeaderBlock(List<SourceString> labels) {
     HBasicBlock result = addNewBlock();
-    result.loopInformation = new HLoopInformation(result);
+    result.loopInformation = new HLoopInformation(result, labels);
     return result;
   }
 
@@ -207,6 +208,7 @@ class HBaseVisitor extends HGraphVisitor implements HVisitor {
   visitBailoutTarget(HBailoutTarget node) => visitInstruction(node);
   visitBoolify(HBoolify node) => visitInstruction(node);
   visitBoundsCheck(HBoundsCheck node) => visitCheck(node);
+  visitBreak(HBreak node) => visitGoto(node);
   visitCheck(HCheck node) => visitInstruction(node);
   visitDivide(HDivide node) => visitBinaryArithmetic(node);
   visitEquals(HEquals node) => visitRelational(node);
@@ -349,7 +351,7 @@ class HBasicBlock extends HInstructionList {
 
   HInstructionList phis;
 
-  HLoopInformation loopInformation = null;
+  HBlockInformation blockInformation = null;

[Lasse Reichstein Nielsen, 2012/02/20 13:56:16]

I store both loop information and labeled block information here, depending on
what the block represents. Accessors below check the type before returning it.

[floitsch, 2012/02/20 19:01:54]

I would prefer two fields. This way we could get rid of the marker-class too.

[Lasse Reichstein Nielsen, 2012/02/21 13:53:56]

Done.

   HBasicBlock parentLoopHeader = null;
   List<HBailoutTarget> bailouts;
 
@@ -359,6 +361,11 @@ class HBasicBlock extends HInstructionList {
   HBasicBlock dominator = null;
   final List<HBasicBlock> dominatedBlocks;
 
+  // For recognizing labeled statements.
+  List<SourceString> labels;
+
+  bool isBlockEnd;
+
   HBasicBlock() : this.withId(null);
   HBasicBlock.withId(this.id)
       : phis = new HInstructionList(),
@@ -371,9 +378,35 @@ class HBasicBlock extends HInstructionList {
   bool isOpen() => status == STATUS_OPEN;
   bool isClosed() => status == STATUS_CLOSED;
 
-  bool isLoopHeader() => loopInformation !== null;
+  bool isLoopHeader() => blockInformation is HLoopInformation;
+  bool hasLabeledBlockInformation() =>
+      blockInformation is HLabeledBlockInformation;
   bool hasBailouts() => !bailouts.isEmpty();
 
+  void set loopInformation(HLoopInformation info) {
+    assert(this.blockInformation === null);
+    blockInformation = info;
+  }
+
+  void set labeledBlockInformation(HLabeledBlockInformation info) {
+    assert(this.blockInformation === null);
+    blockInformation = info;
+  }
+
+  HLoopInformation get loopInformation() {
+    if (blockInformation is HLoopInformation) {
+      return blockInformation;
+    }
+    return null;
+  }
+
+  HLabeledBlockInformation get labeledBlockInformation() {
+    if (blockInformation is HLabeledBlockInformation) {
+      return blockInformation;
+    }
+    return null;
+  }
+
   void open() {
     assert(isNew());
     status = STATUS_OPEN;
@@ -583,12 +616,24 @@ class HBasicBlock extends HInstructionList {
   }
 }
 
-class HLoopInformation {
+class HBlockInformation {
+  // Just a marker class.
+}
+
+class HLabeledBlockInformation extends HBlockInformation {
+  final HBasicBlock start;
+  final HBasicBlock end;
+  final List<SourceString> labels;
+  HLabeledBlockInformation(this.start, this.end, this.labels);
+}
+
+class HLoopInformation extends HBlockInformation {
   final HBasicBlock header;
   final List<HBasicBlock> blocks;
   final List<HBasicBlock> backEdges;
+  final List<SourceString> labels;
 
-  HLoopInformation(this.header)
+  HLoopInformation(this.header, this.labels)
       : blocks = new List<HBasicBlock>(),
         backEdges = new List<HBasicBlock>();
 
@@ -1634,6 +1679,13 @@ class HGoto extends HControlFlow {
   accept(HVisitor visitor) => visitor.visitGoto(this);
 }
 
+class HBreak extends HGoto {
+  final SourceString label;
+  HBreak([this.label]);
+  toString() => 'break';
+  accept(HVisitor visitor) => visitor.visitBreak(this);
+}
+
 class HTry extends HControlFlow {
   HParameterValue exception;
   HBasicBlock finallyBlock;