[interpreter] Translate exception handlers into graph.

src/compiler/bytecode-graph-builder.h

Index: src/compiler/bytecode-graph-builder.h
diff --git a/src/compiler/bytecode-graph-builder.h b/src/compiler/bytecode-graph-builder.h
index 9c8c3f9e956439433cc36425271990585119e677..77053595228fdc3bbf155f9d2e93cc164e002867 100644
--- a/src/compiler/bytecode-graph-builder.h
+++ b/src/compiler/bytecode-graph-builder.h
@@ -175,6 +175,9 @@ class BytecodeGraphBuilder {
   void MergeEnvironmentsOfForwardBranches(int source_offset);
   void BuildLoopHeaderForBackwardBranches(int source_offset);
 
+  // Simulates entry and exit of exception handlers.
+  void EnterAndExitExceptionHandlers(int current_offset);
+
   // Attaches a frame state to |node| for the entry to the function.
   void PrepareEntryFrameState(Node* node);
 
@@ -182,6 +185,16 @@ class BytecodeGraphBuilder {
   // new nodes.
   static const int kInputBufferSizeIncrement = 64;
 
+  // An abstract representation for an exception handler that is being
+  // entered and exited while the graph builder is iterating over the
+  // underlying bytecode. The exception handlers within the bytecode are
+  // well scoped, hence will form a stack during iteration.
+  struct ExceptionHandler {
+    int start_offset_;    // Start offset of the handled area in the bytecode.
+    int end_offset_;      // End offset of the handled area in the bytecode.
+    int handler_offset_;  // Handler entry offset within the bytecode.
+  };
+
   // Field accessors
   CommonOperatorBuilder* common() const { return jsgraph_->common(); }
   Zone* graph_zone() const { return graph()->zone(); }
@@ -192,6 +205,9 @@ class BytecodeGraphBuilder {
   const Handle<BytecodeArray>& bytecode_array() const {
     return bytecode_array_;
   }
+  const Handle<HandlerTable>& exception_handler_table() const {
+    return exception_handler_table_;
+  }
   const FrameStateFunctionInfo* frame_state_function_info() const {
     return frame_state_function_info_;
   }
@@ -214,7 +230,7 @@ class BytecodeGraphBuilder {
     return branch_analysis_;
   }
 
-  void set_branch_analysis(const BytecodeBranchAnalysis* branch_analysis) {
+  void set_branch_analysis(BytecodeBranchAnalysis* branch_analysis) {
     branch_analysis_ = branch_analysis;
   }
 
@@ -227,12 +243,12 @@ class BytecodeGraphBuilder {
   CompilationInfo* info_;
   JSGraph* jsgraph_;
   Handle<BytecodeArray> bytecode_array_;
+  Handle<HandlerTable> exception_handler_table_;
   const FrameStateFunctionInfo* frame_state_function_info_;
   const interpreter::BytecodeArrayIterator* bytecode_iterator_;
-  const BytecodeBranchAnalysis* branch_analysis_;
+  BytecodeBranchAnalysis* branch_analysis_;  // TODO(mstarzinger): Make const.
   Environment* environment_;
 
-
   // Merge environments are snapshots of the environment at a particular
   // bytecode offset to be merged into a later environment.
   ZoneMap<int, Environment*> merge_environments_;
@@ -241,6 +257,10 @@ class BytecodeGraphBuilder {
   // where it is known there are back branches, ie a loop header.
   ZoneMap<int, Environment*> loop_header_environments_;
 
+  // Exception handlers currently entered by the iteration.
+  ZoneStack<ExceptionHandler> exception_handlers_;
+  int current_exception_handler_;
+
   // Temporary storage for building node input lists.
   int input_buffer_size_;
   Node** input_buffer_;