Add support for [PutForwards] IDL extended attribute

Source/bindings/scripts/code_generator_v8.pm

 # Copyright (C) 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
 # Copyright (C) 2006 Anders Carlsson <andersca@mac.com>
 # Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
 # Copyright (C) 2006 Alexey Proskuryakov <ap@webkit.org>
 # Copyright (C) 2006 Apple Computer, Inc.
 # Copyright (C) 2007, 2008, 2009, 2012 Google Inc.
 # Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
 # Copyright (C) Research In Motion Limited 2010. All rights reserved.
 # Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
 # Copyright (C) 2012 Ericsson AB. All rights reserved.
@@ skipping 1101 matching lines @@
 sub HasCustomMethod
 {
     my $attrExt = shift;
     return $attrExt->{"Custom"};
 }
 
 sub IsReadonly
 {
     my $attribute = shift;
     my $attrExt = $attribute->extendedAttributes;
-    return $attribute->isReadOnly && !$attrExt->{"Replaceable"};
+    return $attribute->isReadOnly && !$attrExt->{"Replaceable"} && !$attrExt->{"PutForwards"};
 }
 
 sub GetV8ClassName
 {
     my $interface = shift;
     return "V8" . $interface->name;
 }
 
 sub GetImplName
 {
@@ skipping 649 matching lines @@
         $code .= "    ${v8ClassName}::${attrName}AttributeSetterCustom(name, value, info);\n";
     } else {
         $code .= "    ${implClassName}V8Internal::${attrName}AttributeSetter${forMainWorldSuffix}(name, value, info);\n";
     }
     $code .= "    TRACE_EVENT_SET_SAMPLING_STATE(\"V8\", \"Execution\");\n";
     $code .= "}\n\n";
     $code .= "#endif // ${conditionalString}\n\n" if $conditionalString;
     $implementation{nameSpaceInternal}->add($code);
 }
 
+sub FindAttributeWithName
+{
+    my $interface = shift;
+    my $attrName = shift;
+
+    foreach my $attribute (@{$interface->attributes}) {
+        if ($attribute->name eq $attrName) {
+            return $attribute;
+        }
+    }
+}
+
 sub GenerateNormalAttributeSetter
 {
     my $attribute = shift;
     my $interface = shift;
     my $forMainWorldSuffix = shift;
 
     my $interfaceName = $interface->name;
     my $implClassName = GetImplName($interface);
     my $v8ClassName = GetV8ClassName($interface);
     my $attrName = $attribute->name;
@@ skipping 41 matching lines @@
             $code .= "        setDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet(\"${attrName}\", \"${interfaceName}\", \"The attribute is read-only.\"), info.GetIsolate());\n";
             $code .= "        return;\n";
             $code .= "    }\n";
             $code .= "    $svgWrappedNativeType& impInstance = wrapper->propertyReference();\n";
             $code .= "    $svgWrappedNativeType* imp = &impInstance;\n";
         }
     } elsif ($attrExt->{"OnProto"}) {
         $code .= <<END;
     ${implClassName}* imp = ${v8ClassName}::toNative(info.Holder());
 END
+    } elsif($attrExt->{"PutForwards"}) {
+        my $destinationAttrName = $attrExt->{"PutForwards"};
+        my $destinationInterface = ParseInterface($attrType);
+        die "[PutForwards=x] value must be a wrapper type" unless $destinationInterface;
+        my $destinationAttribute = FindAttributeWithName($destinationInterface, $destinationAttrName);
+        die "[PutForwards=x] could not find $destinationAttrName in interface $attrType" unless $destinationAttribute;
+        $code .= <<END;
+    ${implClassName}* proxyImp = ${v8ClassName}::toNative(info.Holder());
+    ${attrType}* imp = proxyImp->${attrName}();
+    if (!imp)
+        return;
+END
+        # Override attribute and fall through to forward setter call.
+        $attribute = $destinationAttribute;
+        $attrName = $attribute->name;
+        $attrType = $attribute->type;
+        $attrExt = $attribute->extendedAttributes;
     } else {
         my $reflect = $attribute->extendedAttributes->{"Reflect"};
         if ($reflect && InheritsInterface($interface, "Node") && $attrType eq "DOMString") {
             # Generate super-compact call for regular attribute setter:
             my $contentAttributeName = $reflect eq "VALUE_IS_MISSING" ? lc $attrName : $reflect;
             my $namespace = NamespaceForAttributeName($interfaceName, $contentAttributeName);
             my $mode = GetV8StringResourceMode($attribute->extendedAttributes);
             AddToImplIncludes("${namespace}.h");
             $code .= "    Element* imp = V8Element::toNative(info.Holder());\n";
             $code .= "    V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<$mode>, stringResource, value);\n";
@@ skipping 4327 matching lines @@
     my $interface = shift;
 
     return 1 if $interface->extendedAttributes->{"CustomToV8"};
     return 1 if $interface->extendedAttributes->{"SpecialWrapFor"};
     return 1 if InheritsInterface($interface, "Document");
 
     return 0;
 }
 
 1;