Refactoring PropertyCallbackInfo & FunctionCallbackInfo, step 1.

src/stub-cache.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
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@@ skipping 1260 matching lines @@
   // TODO(rossberg): Support symbols in the API.
   if (name_handle->IsSymbol())
     return isolate->heap()->no_interceptor_result_sentinel();
   Handle<String> name = Handle<String>::cast(name_handle);
 
   Address getter_address = v8::ToCData<Address>(interceptor_info->getter());
   v8::NamedPropertyGetterCallback getter =
       FUNCTION_CAST<v8::NamedPropertyGetterCallback>(getter_address);
   ASSERT(getter != NULL);
 
-  Handle<JSObject> receiver =
-      args.at<JSObject>(kArgsOffset - PCA::kThisIndex);
-  Handle<JSObject> holder =
-      args.at<JSObject>(kArgsOffset - PCA::kHolderIndex);
+  int this_index = kArgsOffset - PCA::kThisIndex;
+  int holder_index = kArgsOffset - PCA::kHolderIndex;
+  if (PCA::kThisIndex < PCA::kReturnValueOffset)

[Michael Starzinger, 2013/09/11 09:55:19]

Instead of overlaying the indices used for the arguments object here with PCA,
we should just use a separate set of constant that describes the layout.
Decouples those two things and avoids this magic "minus 2" computation. I would
put the index constant into stub-cache.h either at the top-level or into the
StubCompiler class.

[marja, 2013/09/11 16:35:32]

Done.

+      this_index -= 2;
+  if (PCA::kHolderIndex < PCA::kReturnValueOffset)
+      holder_index -= 2;
+  Handle<JSObject> receiver = args.at<JSObject>(this_index);
+  Handle<JSObject> holder = args.at<JSObject>(holder_index);
   PropertyCallbackArguments callback_args(isolate,
                                           interceptor_info->data(),
                                           *receiver,
                                           *holder);
   {
     // Use the interceptor getter.
     HandleScope scope(isolate);
     v8::Handle<v8::Value> r =
         callback_args.Call(getter, v8::Utils::ToLocal(name));
     RETURN_IF_SCHEDULED_EXCEPTION(isolate);
@@ skipping 28 matching lines @@
 
 static MaybeObject* LoadWithInterceptor(Arguments* args,
                                         PropertyAttributes* attrs) {
   typedef PropertyCallbackArguments PCA;
   static const int kArgsOffset = kAccessorInfoOffsetInInterceptorArgs;
   Handle<Name> name_handle = args->at<Name>(0);
   Handle<InterceptorInfo> interceptor_info = args->at<InterceptorInfo>(1);
   ASSERT(kArgsOffset == 2);
   // No ReturnValue in interceptors.
   ASSERT_EQ(kArgsOffset + PCA::kArgsLength - 2, args->length());
-  Handle<JSObject> receiver_handle =
-      args->at<JSObject>(kArgsOffset - PCA::kThisIndex);
-  Handle<JSObject> holder_handle =
-      args->at<JSObject>(kArgsOffset - PCA::kHolderIndex);
+  int this_index = kArgsOffset - PCA::kThisIndex;
+  int holder_index = kArgsOffset - PCA::kHolderIndex;
+  if (PCA::kThisIndex < PCA::kReturnValueOffset)
+      this_index -= 2;
+  if (PCA::kHolderIndex < PCA::kReturnValueOffset)
+      holder_index -= 2;
+  Handle<JSObject> receiver_handle = args->at<JSObject>(this_index);
+  Handle<JSObject> holder_handle = args->at<JSObject>(holder_index);
 
   Isolate* isolate = receiver_handle->GetIsolate();
 
   // TODO(rossberg): Support symbols in the API.
   if (name_handle->IsSymbol())
     return holder_handle->GetPropertyPostInterceptor(
         *receiver_handle, *name_handle, attrs);
   Handle<String> name = Handle<String>::cast(name_handle);
 
   Address getter_address = v8::ToCData<Address>(interceptor_info->getter());
@@ skipping 914 matching lines @@
           Handle<FunctionTemplateInfo>(
               FunctionTemplateInfo::cast(signature->receiver()));
     }
   }
 
   is_simple_api_call_ = true;
 }
 
 
 } }  // namespace v8::internal