[wasm] Stack inspection support for asm.js frames

src/frames.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_FRAMES_H_
 #define V8_FRAMES_H_
 
 #include "src/allocation.h"
 #include "src/handles.h"
 #include "src/safepoint-table.h"
@@ skipping 716 matching lines @@
 
 class StandardFrame : public StackFrame {
  public:
   // Testers.
   bool is_standard() const override { return true; }
 
   // Accessors.
   virtual Object* receiver() const;
   virtual Script* script() const;
   virtual Object* context() const;
+  virtual int position() const;
 
   // Access the expressions in the stack frame including locals.
   inline Object* GetExpression(int index) const;
   inline void SetExpression(int index, Object* value);
   int ComputeExpressionsCount() const;
 
   // Access the parameters.
   virtual Object* GetParameter(int index) const;
   virtual int ComputeParametersCount() const;
 
@@ skipping 203 matching lines @@
   friend class StackFrameIteratorBase;
 
   Object* StackSlotAt(int index) const;
 };
 
 
 class InterpretedFrame : public JavaScriptFrame {
  public:
   Type type() const override { return INTERPRETED; }
 
+  // Accessors.
+  int position() const override;
+
   // Lookup exception handler for current {pc}, returns -1 if none found.
   int LookupExceptionHandlerInTable(
       int* data, HandlerTable::CatchPrediction* prediction) override;
 
   // Returns the current offset into the bytecode stream.
   int GetBytecodeOffset() const;
 
   // Updates the current offset into the bytecode stream, mainly used for stack
   // unwinding to continue execution at a different bytecode offset.
   void PatchBytecodeOffset(int new_offset);
@@ skipping 90 matching lines @@
   // returns the stack slot count of the entire frame.
   int LookupExceptionHandlerInTable(int* data);
 
   // Determine the code for the frame.
   Code* unchecked_code() const override;
 
   // Accessors.
   Object* wasm_obj() const;
   uint32_t function_index() const;
   Script* script() const override;
+  int position() const override;
 
   static WasmFrame* cast(StackFrame* frame) {
     DCHECK(frame->is_wasm());
     return static_cast<WasmFrame*>(frame);
   }
 
  protected:
   inline explicit WasmFrame(StackFrameIteratorBase* iterator);
 
   Address GetCallerStackPointer() const override;
@@ skipping 241 matching lines @@
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FRAMES_H_