Refactor JavaScriptFrame::function() to return a JSFunction* and remove associated casts.

src/isolate.cc

 // Copyright 2012 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 604 matching lines @@
 // for the stack trace to be collected.  The first time a construct
 // call to this function is encountered it is skipped.  The seen_caller
 // in/out parameter is used to remember if the caller has been seen
 // yet.
 static bool IsVisibleInStackTrace(StackFrame* raw_frame,
                                   Object* caller,
                                   bool* seen_caller) {
   // Only display JS frames.
   if (!raw_frame->is_java_script()) return false;
   JavaScriptFrame* frame = JavaScriptFrame::cast(raw_frame);
-  Object* raw_fun = frame->function();
-  // Not sure when this can happen but skip it just in case.
-  if (!raw_fun->IsJSFunction()) return false;
-  if ((raw_fun == caller) && !(*seen_caller)) {
+  JSFunction* fun = frame->function();
+  if ((fun == caller) && !(*seen_caller)) {
     *seen_caller = true;
     return false;
   }
   // Skip all frames until we've seen the caller.
   if (!(*seen_caller)) return false;
   // Also, skip non-visible built-in functions and any call with the builtins
   // object as receiver, so as to not reveal either the builtins object or
   // an internal function.
   // The --builtins-in-stack-traces command line flag allows including
   // internal call sites in the stack trace for debugging purposes.
   if (!FLAG_builtins_in_stack_traces) {
-    JSFunction* fun = JSFunction::cast(raw_fun);
     if (frame->receiver()->IsJSBuiltinsObject() ||
         (fun->IsBuiltin() && !fun->shared()->native())) {
       return false;
     }
   }
   return true;
 }
 
 
 Handle<JSArray> Isolate::CaptureSimpleStackTrace(Handle<JSObject> error_object,
@@ skipping 543 matching lines @@
 
 void Isolate::PrintCurrentStackTrace(FILE* out) {
   StackTraceFrameIterator it(this);
   while (!it.done()) {
     HandleScope scope(this);
     // Find code position if recorded in relocation info.
     JavaScriptFrame* frame = it.frame();
     int pos = frame->LookupCode()->SourcePosition(frame->pc());
     Handle<Object> pos_obj(Smi::FromInt(pos), this);
     // Fetch function and receiver.
-    Handle<JSFunction> fun(JSFunction::cast(frame->function()));
+    Handle<JSFunction> fun(frame->function());
     Handle<Object> recv(frame->receiver(), this);
     // Advance to the next JavaScript frame and determine if the
     // current frame is the top-level frame.
     it.Advance();
     Handle<Object> is_top_level = it.done()
         ? factory()->true_value()
         : factory()->false_value();
     // Generate and print stack trace line.
     Handle<String> line =
         Execution::GetStackTraceLine(recv, fun, pos_obj, is_top_level);
     if (line->length() > 0) {
       line->PrintOn(out);
       PrintF(out, "\n");
     }
   }
 }
 
 
 void Isolate::ComputeLocation(MessageLocation* target) {
   *target = MessageLocation(Handle<Script>(heap_.empty_script()), -1, -1);
   StackTraceFrameIterator it(this);
   if (!it.done()) {
     JavaScriptFrame* frame = it.frame();
-    JSFunction* fun = JSFunction::cast(frame->function());
+    JSFunction* fun = frame->function();
     Object* script = fun->shared()->script();
     if (script->IsScript() &&
         !(Script::cast(script)->source()->IsUndefined())) {
       int pos = frame->LookupCode()->SourcePosition(frame->pc());
       // Compute the location from the function and the reloc info.
       Handle<Script> casted_script(Script::cast(script));
       *target = MessageLocation(casted_script, pos, pos + 1);
     }
   }
 }
@@ skipping 1269 matching lines @@
 
 #ifdef DEBUG
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                       \
 const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
 ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
 ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
 } }  // namespace v8::internal