Fix determining of JS lower stack bottom used in profiler's JS stack tracer to work with Chromium.

src/top.h

Index: src/top.h
diff --git a/src/top.h b/src/top.h
index 8e928ed6313645acb389ed7ebdafc6dc7e5922f7..dcaeec50cab21a167c2cabdda725cfb4b2d4e114 100644
--- a/src/top.h
+++ b/src/top.h
@@ -65,6 +65,9 @@ class ThreadLocalTop BASE_EMBEDDED {
   // Stack.
   Address c_entry_fp_;  // the frame pointer of the top c entry frame
   Address handler_;   // try-blocks are chained through the stack
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  Address js_entry_sp_;  // the stack pointer of the bottom js entry frame
+#endif
   bool stack_is_cooked_;
   inline bool stack_is_cooked() { return stack_is_cooked_; }
   inline void set_stack_is_cooked(bool value) { stack_is_cooked_ = value; }
@@ -76,9 +79,16 @@ class ThreadLocalTop BASE_EMBEDDED {
   v8::FailedAccessCheckCallback failed_access_check_callback_;
 };
 
+#ifdef ENABLE_LOGGING_AND_PROFILING
+#define JS_ENTRY_SP_ADDRESS(C) C(js_entry_sp_address)
+#else
+#define JS_ENTRY_SP_ADDRESS(C)
+#endif
+
 #define TOP_ADDRESS_LIST(C) \

[Søren Thygesen Gjesse, 2009/06/02 09:00:25]

How about making two lists TOP_ADDRESS_LIST_ALWAYS and
TOP_ADDRESS_LIST_PROFILING? See builtinsh.h and runtime.h where there is a
separate list for debugger related stuff (in runtime.h there is two _ALWAYS
lists due to Visual C++ choking on long macros).

[Mikhail Naganov, 2009/06/02 09:32:32]

Good idea. Done.

   C(handler_address)                   \
   C(c_entry_fp_address)                \
+  JS_ENTRY_SP_ADDRESS(C)               \
   C(context_address)                   \
   C(pending_exception_address)         \
   C(external_caught_exception_address)
@@ -179,6 +189,16 @@ class Top {
   }
   static inline Address* handler_address() { return &thread_local_.handler_; }
 
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  // Bottom JS entry (see StackTracer::Trace in log.cc).
+  static Address js_entry_sp(ThreadLocalTop* thread) {
+    return thread->js_entry_sp_;
+  }
+  static inline Address* js_entry_sp_address() {
+    return &thread_local_.js_entry_sp_;
+  }
+#endif
+
   // Generated code scratch locations.
   static void* formal_count_address() { return &thread_local_.formal_count_; }