[interpreter] First implementation of stack unwinding.

src/frames.cc

Index: src/frames.cc
diff --git a/src/frames.cc b/src/frames.cc
index d60ab29c4e62c2e60cc52a7b1cf54378076ed8e3..3cf1dd82464010aafc47aeabf258e89d0e2212f8 100644
--- a/src/frames.cc
+++ b/src/frames.cc
@@ -1128,6 +1128,31 @@ Object* OptimizedFrame::StackSlotAt(int index) const {
 }
 
 
+int InterpretedFrame::LookupExceptionHandlerInTable(
+    int* stack_slots, HandlerTable::CatchPrediction* prediction) {
+  BytecodeArray* bytecode = function()->shared()->bytecode_array();
+  HandlerTable* table = HandlerTable::cast(bytecode->handler_table());
+  int pc_offset = GetBytecodeOffset() + 1;  // Point after current bytecode.
+  return table->LookupRange(pc_offset, stack_slots, prediction);
+}
+
+
+int InterpretedFrame::GetBytecodeOffset() const {
+  STATIC_ASSERT(InterpreterFrameConstants::kBytecodeOffsetFromFp ==
+                StandardFrameConstants::kExpressionsOffset - kPointerSize);
+  int raw_offset = Smi::cast(GetExpression(1))->value();

[rmcilroy, 2016/01/20 08:52:13]

Nit - could you pull the '1' out to a constant somewhere? It would just make
things easier if we need to change the frame layout later.

[Michael Starzinger, 2016/01/20 11:45:27]

Done. Added the constant to the InterpreterFrameConstants class.

+  return raw_offset - BytecodeArray::kHeaderSize + kHeapObjectTag;
+}
+
+
+void InterpretedFrame::PatchBytecodeOffset(int new_offset) {
+  STATIC_ASSERT(InterpreterFrameConstants::kBytecodeOffsetFromFp ==
+                StandardFrameConstants::kExpressionsOffset - kPointerSize);
+  int raw_offset = new_offset + BytecodeArray::kHeaderSize - kHeapObjectTag;
+  SetExpression(1, Smi::FromInt(raw_offset));
+}
+
+
 int ArgumentsAdaptorFrame::GetNumberOfIncomingArguments() const {
   return Smi::cast(GetExpression(0))->value();
 }