Process correctly stepping into function calls

src/debug.cc

 // 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 1242 matching lines @@
 
 
 void Debug::SetBreak(StackFrame::Id break_frame_id, int break_id) {
   thread_local_.break_frame_id_ = break_frame_id;
   thread_local_.break_id_ = break_id;
 }
 
 
 // Handle stepping into a function.
 void Debug::HandleStepIn(Handle<JSFunction> function,
+                         Handle<Object> holder,
                          Address fp,
                          bool is_constructor) {
   // If the frame pointer is not supplied by the caller find it.
   if (fp == 0) {
     StackFrameIterator it;
     it.Advance();
     // For constructor functions skip another frame.
     if (is_constructor) {
       ASSERT(it.frame()->is_construct());
       it.Advance();
     }
     fp = it.frame()->fp();
   }
 
   // Flood the function with one-shot break points if it is called from where
   // step into was requested.
   if (fp == Debug::step_in_fp()) {
     // Don't allow step into functions in the native context.
     if (function->context()->global() != Top::context()->builtins()) {
       if (function->shared()->code() ==
           Builtins::builtin(Builtins::FunctionApply) ||
           function->shared()->code() ==
           Builtins::builtin(Builtins::FunctionCall)) {
         // Handle function.apply and function.call separately to flood the
         // function to be called and not the code for Builtins::FunctionApply or
-        // Builtins::FunctionCall. At the point of the call IC to call either
-        // Builtins::FunctionApply or Builtins::FunctionCall the expression
-        // stack has the following content:
-        //   symbol "apply" or "call"
-        //   function apply or call was called on
-        //   receiver for apply or call (first parameter to apply or call)
-        //   ... further arguments to apply or call.
-        JavaScriptFrameIterator it;
-        ASSERT(it.frame()->fp() == fp);
-        ASSERT(it.frame()->GetExpression(1)->IsJSFunction());
-        if (it.frame()->GetExpression(1)->IsJSFunction()) {
-          Handle<JSFunction>
-              actual_function(JSFunction::cast(it.frame()->GetExpression(1)));
-          Handle<SharedFunctionInfo> actual_shared(actual_function->shared());
-          Debug::FloodWithOneShot(actual_shared);
+        // Builtins::FunctionCall. The receiver of call/apply is the target
+        // function.
+        if (!holder.is_null() && holder->IsJSFunction()) {
+          Handle<SharedFunctionInfo> shared_info(
+              JSFunction::cast(*holder)->shared());
+          Debug::FloodWithOneShot(shared_info);
         }
       } else {
         Debug::FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared()));
       }
     }
   }
 }
 
 
 void Debug::ClearStepping() {
@@ skipping 1235 matching lines @@
 
 
 void LockingCommandMessageQueue::Clear() {
   ScopedLock sl(lock_);
   queue_.Clear();
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal