Switch-implementation.

frog/leg/ssa/nodes.dart

 // Copyright (c) 2011, 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.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBailoutTarget(HBailoutTarget node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
@@ skipping 124 matching lines @@
     blocks.add(block);
     assert(blocks[id] === block);
   }
 
   HBasicBlock addNewBlock() {
     HBasicBlock result = new HBasicBlock();
     addBlock(result);
     return result;
   }
 
-  HBasicBlock addNewLoopHeaderBlock(List<SourceString> labels) {
+  HBasicBlock addNewLoopHeaderBlock(List<LabelElement> labels) {
     HBasicBlock result = addNewBlock();
     result.loopInformation = new HLoopInformation(result, labels);
     return result;
   }
 
   static HType mapConstantTypeToSsaType(Constant constant) {
     if (constant.isNull()) return HType.UNKNOWN;
     if (constant.isBool()) return HType.BOOLEAN;
     if (constant.isInt()) return HType.INTEGER;
     if (constant.isDouble()) return HType.DOUBLE;
@@ skipping 158 matching lines @@
 }
 
 class SubGraph {
   // The first and last block of the sub-graph.
   final HBasicBlock start;
   final HBasicBlock end;
 
   const SubGraph(this.start, this.end);
 
   bool contains(HBasicBlock block) {
+    assert(start !== null);
+    assert(end !== null);
+    assert(block !== null);
     return start.id <= block.id && block.id <= end.id;
   }
 }
 
 class HInstructionList {
   HInstruction first = null;
   HInstruction last = null;
 
   bool isEmpty() {
     return first === null;
@@ skipping 80 matching lines @@
   HLabeledBlockInformation labeledBlockInformation = null;
   HBasicBlock parentLoopHeader = null;
   List<HBailoutTarget> bailouts;
 
   final List<HBasicBlock> predecessors;
   List<HBasicBlock> successors;
 
   HBasicBlock dominator = null;
   final List<HBasicBlock> dominatedBlocks;
 
-  // For recognizing labeled statements.
-  List<SourceString> labels;
-
   HBasicBlock() : this.withId(null);
   HBasicBlock.withId(this.id)
       : phis = new HInstructionList(),
         predecessors = <HBasicBlock>[],
         successors = const <HBasicBlock>[],
         dominatedBlocks = <HBasicBlock>[],
         bailouts = <HBailoutTarget>[];
 
   int hashCode() => id;
 
@@ skipping 215 matching lines @@
   }
 }
 
 class HBlockInformation {
   // Just a marker class.
 }
 
 class HLabeledBlockInformation extends HBlockInformation {
   final SubGraph body;
   final HBasicBlock joinBlock;
-  final List<SourceString> labels;
-  HLabeledBlockInformation(this.body, this.joinBlock, this.labels);
+  final List<LabelElement> labels;
+  final StatementElement target;
+
+  HLabeledBlockInformation(this.body, this.joinBlock,
+                           List<LabelElement> labels) :
+      this.labels = labels, this.target = labels[0].target;
+
+  // For creating block information when there are no explicit labels.
+  HLabeledBlockInformation.implicit(this.body, this.joinBlock, this.target) :
+      this.labels = const<LabelElement>[];
+
+  bool get isSwitch() => target is SwitchStatementElement;
 }
 
 class HLoopInformation extends HBlockInformation {
   final HBasicBlock header;
   final List<HBasicBlock> blocks;
   final List<HBasicBlock> backEdges;
-  final List<SourceString> labels;
+  final List<LabelElement> labels;
 
   HLoopInformation(this.header, this.labels)
       : blocks = new List<HBasicBlock>(),
         backEdges = new List<HBasicBlock>();
 
   void addBackEdge(HBasicBlock predecessor) {
     backEdges.add(predecessor);
     addBlock(predecessor);
   }
 
@@ skipping 919 matching lines @@
   accept(HVisitor visitor) => visitor.visitExit(this);
 }
 
 class HGoto extends HControlFlow {
   HGoto() : super(const <HInstruction>[]);
   toString() => 'goto';
   accept(HVisitor visitor) => visitor.visitGoto(this);
 }
 
 class HBreak extends HGoto {
-  final SourceString label;
-  HBreak([this.label]);
-  toString() => 'break';
+  // Target is either a LabelElement or a StatementElement.
+  final StatementElement target;
+  final LabelElement label;
+  HBreak(this.target) : label = null;
+  HBreak.toLabel(LabelElement label) : label = label, target = label.target;
+  toString() => (target is LabelElement) ? 'break ${label.labelName}' : 'break';
   accept(HVisitor visitor) => visitor.visitBreak(this);
 }
 
 class HTry extends HControlFlow {
   HParameterValue exception;
   HBasicBlock finallyBlock;
   HTry() : super(const <HInstruction>[]);
   toString() => 'try';
   accept(HVisitor visitor) => visitor.visitTry(this);
   HBasicBlock get joinBlock() => this.block.successors.last();
@@ skipping 499 matching lines @@
 class HIfBlockInformation {
   final HIf branch;
   final SubGraph thenGraph;
   final SubGraph elseGraph;
   final HBasicBlock joinBlock;
   HIfBlockInformation(this.branch,
                       this.thenGraph,
                       this.elseGraph,
                       this.joinBlock);
 }