Enhance SafeStackFrameIterator to avoid triggering assertions in debug mode.

src/frames.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 184 matching lines @@
 
 
   // Printing support.
   enum PrintMode { OVERVIEW, DETAILS };
   virtual void Print(StringStream* accumulator,
                      PrintMode mode,
                      int index) const { }
 
  protected:
   struct State {
+    State() : sp(NULL), fp(NULL), pc_address(NULL) { }
     Address sp;
     Address fp;
     Address* pc_address;
   };
 
   explicit StackFrame(StackFrameIterator* iterator) : iterator_(iterator) { }
   virtual ~StackFrame() { }
 
   // Compute the stack pointer for the calling frame.
   virtual Address GetCallerStackPointer() const = 0;
@@ skipping 96 matching lines @@
 
   static ExitFrame* cast(StackFrame* frame) {
     ASSERT(frame->is_exit());
     return static_cast<ExitFrame*>(frame);
   }
 
   // Compute the state and type of an exit frame given a frame
   // pointer. Used when constructing the first stack frame seen by an
   // iterator and the frames following entry frames.
   static Type GetStateForFramePointer(Address fp, State* state);
+  static Address ComputeStackPointer(Address fp);
+  static void FillState(Address fp, Address sp, State* state);
 
  protected:
   explicit ExitFrame(StackFrameIterator* iterator) : StackFrame(iterator) { }
 
   virtual Address GetCallerStackPointer() const;
 
  private:
   virtual void ComputeCallerState(State* state) const;
 
   friend class StackFrameIterator;
@@ skipping 105 matching lines @@
  protected:
   explicit JavaScriptFrame(StackFrameIterator* iterator)
       : StandardFrame(iterator) { }
 
   virtual Address GetCallerStackPointer() const;
 
  private:
   inline Object* function_slot_object() const;
 
   friend class StackFrameIterator;
+  friend class StackTracer;
 };
 
 
 // Arguments adaptor frames are automatically inserted below
 // JavaScript frames when the actual number of parameters does not
 // match the formal number of parameters.
 class ArgumentsAdaptorFrame: public JavaScriptFrame {
  public:
   virtual Type type() const { return ARGUMENTS_ADAPTOR; }
 
@@ skipping 191 matching lines @@
   void Reset();
 
   static bool is_active() { return active_count_ > 0; }
 
   static bool IsWithinBounds(
       Address low_bound, Address high_bound, Address addr) {
     return low_bound <= addr && addr <= high_bound;
   }
 
  private:
+  class StackAddressValidator {
+   public:
+    StackAddressValidator(Address low_bound, Address high_bound)
+        : low_bound_(low_bound), high_bound_(high_bound) { }
+    bool IsValid(Address addr) const {
+      return IsWithinBounds(low_bound_, high_bound_, addr);
+    }
+   private:
+    Address low_bound_;
+    Address high_bound_;
+  };
+
+  class ExitFrameValidator {
+   public:
+    explicit ExitFrameValidator(const StackAddressValidator& validator)
+        : validator_(validator) { }
+    ExitFrameValidator(Address low_bound, Address high_bound)
+        : validator_(low_bound, high_bound) { }
+    bool IsValidFP(Address fp);
+   private:
+    StackAddressValidator validator_;
+  };
+
   bool IsValidStackAddress(Address addr) const {
-    return IsWithinBounds(low_bound_, high_bound_, addr);
+    return stack_validator_.IsValid(addr);
   }
   bool CanIterateHandles(StackFrame* frame, StackHandler* handler);
   bool IsValidFrame(StackFrame* frame) const;
   bool IsValidCaller(StackFrame* frame);
+  static bool IsValidTop(Address low_bound, Address high_bound);
 
   // This is a nasty hack to make sure the active count is incremented
   // before the constructor for the embedded iterator is invoked. This
   // is needed because the constructor will start looking at frames
   // right away and we need to make sure it doesn't start inspecting
   // heap objects.
   class ActiveCountMaintainer BASE_EMBEDDED {
    public:
     ActiveCountMaintainer() { active_count_++; }
     ~ActiveCountMaintainer() { active_count_--; }
   };
 
   ActiveCountMaintainer maintainer_;
   static int active_count_;
-  Address low_bound_;
-  Address high_bound_;
+  StackAddressValidator stack_validator_;
   const bool is_valid_top_;
   const bool is_valid_fp_;
   const bool is_working_iterator_;
   bool iteration_done_;
   StackFrameIterator iterator_;
 };
 
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 typedef JavaScriptFrameIteratorTemp<SafeStackFrameIterator>
@@ skipping 20 matching lines @@
 };
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap();
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_