Support profiler stack sampling in any situation.

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 172 matching lines @@
   // Get the top handler from the current stack iterator.
   inline StackHandler* top_handler() const;
 
   // Compute the stack frame type for the given state.
   static Type ComputeType(State* state);
 
  private:
   const StackFrameIterator* iterator_;
   State state_;
 
+  // Fill in the state of the calling frame.
+  virtual void ComputeCallerState(State* state) const = 0;
+
   // Get the type and the state of the calling frame.
-  virtual Type GetCallerState(State* state) const = 0;
+  virtual Type GetCallerState(State* state) const;
 
   // Cooking/uncooking support.
   void Cook();
   void Uncook();
 
   friend class StackFrameIterator;
   friend class StackHandlerIterator;
+  friend class SafeStackFrameIterator;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StackFrame);
 };
 
 
 // Entry frames are used to enter JavaScript execution from C.
 class EntryFrame: public StackFrame {
  public:
   virtual Type type() const { return ENTRY; }
 
   virtual Code* code() const;
 
   // Garbage collection support.
   virtual void Iterate(ObjectVisitor* v) const;
 
   static EntryFrame* cast(StackFrame* frame) {
     ASSERT(frame->is_entry());
     return static_cast<EntryFrame*>(frame);
   }
 
  protected:
   explicit EntryFrame(StackFrameIterator* iterator) : StackFrame(iterator) { }
 
   // The caller stack pointer for entry frames is always zero. The
   // real information about the caller frame is available through the
   // link to the top exit frame.
   virtual Address GetCallerStackPointer() const { return 0; }
 
  private:
+  virtual void ComputeCallerState(State* state) const;
   virtual Type GetCallerState(State* state) const;
 
   friend class StackFrameIterator;
 };
 
 
 class EntryConstructFrame: public EntryFrame {
  public:
   virtual Type type() const { return ENTRY_CONSTRUCT; }
 
@@ skipping 32 matching lines @@
   // 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);
 
  protected:
   explicit ExitFrame(StackFrameIterator* iterator) : StackFrame(iterator) { }
 
   virtual Address GetCallerStackPointer() const;
 
  private:
-  virtual Type GetCallerState(State* state) const;
+  virtual void ComputeCallerState(State* state) const;
 
   friend class StackFrameIterator;
 };
 
 
 class ExitDebugFrame: public ExitFrame {
  public:
   virtual Type type() const { return EXIT_DEBUG; }
 
   virtual Code* code() const;
@@ skipping 27 matching lines @@
 
   static StandardFrame* cast(StackFrame* frame) {
     ASSERT(frame->is_standard());
     return static_cast<StandardFrame*>(frame);
   }
 
  protected:
   explicit StandardFrame(StackFrameIterator* iterator)
       : StackFrame(iterator) { }
 
-  virtual Type GetCallerState(State* state) const;
+  virtual void ComputeCallerState(State* state) const;
 
   // Accessors.
   inline Address caller_sp() const;
   inline Address caller_fp() const;
   inline Address caller_pc() const;
 
   // Computes the address of the PC field in the standard frame given
   // by the provided frame pointer.
   static inline Address ComputePCAddress(Address fp);
 
@@ skipping 19 matching lines @@
  private:
   friend class StackFrame;
 };
 
 
 class JavaScriptFrame: public StandardFrame {
  public:
   virtual Type type() const { return JAVA_SCRIPT; }
 
   // Accessors.
+  inline bool is_at_function() const;
   inline Object* function() const;
   inline Object* receiver() const;
   inline void set_receiver(Object* value);
 
   // Access the parameters.
   Object* GetParameter(int index) const;
   int ComputeParametersCount() const;
 
   // Temporary way of getting access to the number of parameters
   // passed on the stack by the caller. Once argument adaptor frames
@@ skipping 25 matching lines @@
     return static_cast<JavaScriptFrame*>(frame);
   }
 
  protected:
   explicit JavaScriptFrame(StackFrameIterator* iterator)
       : StandardFrame(iterator) { }
 
   virtual Address GetCallerStackPointer() const;
 
  private:
+  inline Object* function_slot_object() const;
+
   friend class StackFrameIterator;
 };
 
 
 // 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:
   // This sentinel value is temporarily used to distinguish arguments
@@ skipping 76 matching lines @@
 
 
 class StackFrameIterator BASE_EMBEDDED {
  public:
   // An iterator that iterates over the current thread's stack.
   StackFrameIterator();
 
   // An iterator that iterates over a given thread's stack.
   explicit StackFrameIterator(ThreadLocalTop* thread);
 
-  // An iterator that conditionally resets itself on init.
-  explicit StackFrameIterator(bool reset);
+  // An iterator that can start from a given FP address.
+  // If use_top, then work as usual, if fp isn't NULL, use it,
+  // otherwise, do nothing.
+  StackFrameIterator(bool use_top, Address fp, Address sp);
 
   StackFrame* frame() const {
     ASSERT(!done());
     return frame_;
   }
 
   bool done() const { return frame_ == NULL; }
-  void Advance();
+  void Advance() { (this->*advance_)(); }
 
   // Go back to the first frame.
   void Reset();
 
  private:
 #define DECLARE_SINGLETON(ignore, type) type type##_;
   STACK_FRAME_TYPE_LIST(DECLARE_SINGLETON)
 #undef DECLARE_SINGLETON
   StackFrame* frame_;
   StackHandler* handler_;
   ThreadLocalTop* thread_;
+  Address fp_;
+  Address sp_;
+  void (StackFrameIterator::*advance_)();
 
   StackHandler* handler() const {
     ASSERT(!done());
     return handler_;
   }
 
   // Get the type-specific frame singleton in a given state.
   StackFrame* SingletonFor(StackFrame::Type type, StackFrame::State* state);
+  // A helper function, can return a NULL pointer.
+  StackFrame* SingletonFor(StackFrame::Type type);
+
+  void AdvanceWithHandler();
+  void AdvanceWithoutHandler();
 
   friend class StackFrame;
+  friend class SafeStackFrameIterator;
   DISALLOW_COPY_AND_ASSIGN(StackFrameIterator);
 };
 
 
 // Iterator that supports iterating through all JavaScript frames.
 template<typename Iterator>
 class JavaScriptFrameIteratorTemp BASE_EMBEDDED {
  public:
   JavaScriptFrameIteratorTemp() { if (!done()) Advance(); }
 
   explicit JavaScriptFrameIteratorTemp(ThreadLocalTop* thread) :
       iterator_(thread) {
     if (!done()) Advance();
   }
 
   // Skip frames until the frame with the given id is reached.
   explicit JavaScriptFrameIteratorTemp(StackFrame::Id id);
 
-  explicit JavaScriptFrameIteratorTemp(Address low_bound, Address high_bound) :
-      iterator_(low_bound, high_bound) { if (!done()) Advance(); }
+  JavaScriptFrameIteratorTemp(Address fp, Address sp,
+                              Address low_bound, Address high_bound) :
+      iterator_(fp, sp, low_bound, high_bound) {
+    if (!done()) Advance();
+  }
 
   inline JavaScriptFrame* frame() const;
 
   bool done() const { return iterator_.done(); }
   void Advance();
 
   // Advance to the frame holding the arguments for the current
   // frame. This only affects the current frame if it has adapted
   // arguments.
   void AdvanceToArgumentsFrame();
@@ skipping 15 matching lines @@
 // functions in runtime.js.
 class StackTraceFrameIterator: public JavaScriptFrameIterator {
  public:
   StackTraceFrameIterator();
   void Advance();
 };
 
 
 class SafeStackFrameIterator BASE_EMBEDDED {
  public:
-  explicit SafeStackFrameIterator(Address low_bound, Address high_bound);
+  SafeStackFrameIterator(Address fp, Address sp,
+                         Address low_bound, Address high_bound);
 
   StackFrame* frame() const {
     ASSERT(is_working_iterator_);
     return iterator_.frame();
   }
 
   bool done() const { return iteration_done_ ? true : iterator_.done(); }
 
   void Advance();
   void Reset();
 
  private:
-  static bool IsInBounds(
+  static bool IsWithinBounds(
       Address low_bound, Address high_bound, Address addr) {
     return low_bound <= addr && addr <= high_bound;
   }
-  bool IsGoodStackAddress(Address addr) const {
-    return IsInBounds(low_bound_, high_bound_, addr);
+  bool IsValidStackAddress(Address addr) const {
+    return IsWithinBounds(low_bound_, high_bound_, addr);
   }
+  bool IsValidFrame(StackFrame* frame) const;
+  bool IsValidCaller(StackFrame* frame);
 
   Address low_bound_;
   Address high_bound_;
+  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>
     SafeJavaScriptFrameIterator;
 
 
 class SafeStackTraceFrameIterator: public SafeJavaScriptFrameIterator {
  public:
-  explicit SafeStackTraceFrameIterator(Address low_bound, Address high_bound);
+  explicit SafeStackTraceFrameIterator(Address fp, Address sp,
+                                       Address low_bound, Address high_bound);
   void Advance();
 };
 #endif
 
 
 class StackFrameLocator BASE_EMBEDDED {
  public:
   // Find the nth JavaScript frame on the stack. The caller must
   // guarantee that such a frame exists.
   JavaScriptFrame* FindJavaScriptFrame(int n);
 
  private:
   StackFrameIterator iterator_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_