Support union return type for anonymous named/indexed getter

Source/bindings/scripts/CodeGeneratorV8.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 1624 matching lines @@
 END
     } elsif ($attribute->signature->type eq "SerializedScriptValue" && $attrExt->{"CachedAttribute"}) {
         my $getterFunc = ToMethodName($attribute->signature->name);
         $code .= <<END;
     RefPtr<SerializedScriptValue> serialized = imp->${getterFunc}();
     value = serialized ? serialized->deserialize() : v8::Handle<v8::Value>(v8Null(info.GetIsolate()));
     info.Holder()->SetHiddenValue(propertyName, value);
     return value;
 END
     } else {
-        $code .= "    return " . NativeToJSValue($attribute->signature, $expression, "info.Holder()", "info.GetIsolate()", "info", "imp", "ReturnUnsafeHandle", $forMainWorldSuffix).";\n";
+        $code .= "    return " . NativeToJSValue($attribute->signature->type, $attribute->signature->extendedAttributes, $expression, "info.Holder()", "info.GetIsolate()", "info", "imp", "ReturnUnsafeHandle", $forMainWorldSuffix).";\n";

[haraken, 2013/05/15 12:09:43]

You can pass $attribute->signature instead of passing
$attribute->signature->type and $attribute->signature->extendedAttributes.

     }
 
     $code .= "}\n\n";  # end of getter
     $code .= "#endif // ${conditionalString}\n\n" if $conditionalString;
     $implementation{nameSpaceInternal}->add($code);
 }
 
 sub ShouldKeepAttributeAlive
 {
     my ($interface, $attribute, $returnType) = @_;
@@ skipping 1490 matching lines @@
         $code .= "    } else {\n";
         $code .= "        ${conditional}$template->Set(v8::String::NewSymbol(\"$name\"), v8::FunctionTemplate::New(${implClassName}V8Internal::${name}MethodCallback, v8Undefined(), ${signature}, $functionLength)$property_attributes);\n";
         $code .= "    }\n";
     } else {
         $code .= "    ${conditional}$template->Set(v8::String::NewSymbol(\"$name\"), v8::FunctionTemplate::New(${implClassName}V8Internal::${name}MethodCallback, v8Undefined(), ${signature}, $functionLength)$property_attributes);\n";
     }
     $code .= "#endif // ${conditionalString}\n" if $conditionalString;
     return $code;
 }
 
+sub GetIsNullExpression
+{
+    my $type = shift;
+    my $variableName = shift;
+    if (IsRefPtrType($type)) {
+        return "!${variableName}";
+    } else {
+        return "${variableName}.isNull()";
+    }
+}
+
+sub GetReturnJSValueStatements

[haraken, 2013/05/15 12:09:43]

This looks like a duplication of NativeToJSValue(). I think you anyway need to
merge GetReturnJSValueStatements() with NativeToJSValue() at some point where
you want to kill more custom bindings by introducing UnionTypes. So, can we
avoid the duplication now?

+{
+    my $type = shift;
+    my $extendedAttributes = shift;
+    my $value = shift; # expression of native value
+    my $getCreationContext = shift;
+    my $getIsolate = shift;
+    my $getHolderContainer = shift;
+    my $getHolderContainerArg = $getHolderContainer ? ", $getHolderContainer" : "";
+    my $getScriptWrappable = shift;
+    my $getScriptWrappableArg = $getScriptWrappable ? ", $getScriptWrappable" : "";
+    my $returnHandleType = shift;
+    my $returnHandleTypeArg = $returnHandleType ? ", $returnHandleType" : "";
+    my $forMainWorldSuffix = shift;
+
+    # Union type
+    if (ref $type) {

[haraken, 2013/05/15 12:09:43]

'ref $type' is hard to understand. Let's implement a helper method
IsUnionType().

+        my $types = $type->unionType->unionMemberTypes;
+        die "Currently only 2 values of non-union type is supported as union type.\n" unless scalar(@$types)==2 && scalar(grep {ref $_} @$types)==0;
+        my $code = "";
+        for my $i (0 .. scalar(@$types)-1) {
+            my $unionMemberType = $types->[$i];
+            my $jsValue = NativeToJSValue($unionMemberType, $extendedAttributes, "$value.enabledValue${i}()", $getCreationContext, $getIsolate, $getHolderContainer, $getScriptWrappable, $returnHandleType, $forMainWorldSuffix);
+            $code .= <<END;
+    if (${value}.enabledValue${i}())
+        return ${jsValue};
+END
+        }
+        $code .= <<END;
+    return v8Undefined();
+END
+        return $code;
+    } else {
+        my $jsValue = NativeToJSValue($type, $extendedAttributes, $value, $getCreationContext, $getIsolate, $getHolderContainer, $getScriptWrappable, $returnHandleType, $forMainWorldSuffix);
+        return "    return ${jsValue};";
+    }
+}
+
 sub GenerateImplementationIndexedProperty
 {
     my $interface = shift;
     my $interfaceName = $interface->name;
     my $implClassName = GetImplClassName($interface);
     my $v8ClassName = GetV8ClassName($interface);
 
     my $indexedGetterfunction = GetIndexedGetterFunction($interface);
     my $hasCustomIndexedSetter = $interface->extendedAttributes->{"CustomIndexedSetter"};
     my $hasCustomIndexedGetter = $interface->extendedAttributes->{"CustomIndexedGetter"};
@@ skipping 27 matching lines @@
     my $code = "";
     $code .= "    desc->${setOn}Template()->SetIndexedPropertyHandler(${v8ClassName}::indexedPropertyGetter";
     $code .= $hasCustomIndexedSetter ? ", ${v8ClassName}::indexedPropertySetter" : ", 0";
     $code .= ", 0"; # IndexedPropertyQuery -- not being used at the moment.
     $code .= $hasDeleter ? ", ${v8ClassName}::indexedPropertyDeleter" : ", 0";
     $code .= ", nodeCollectionIndexedPropertyEnumerator<${implClassName}>" if $hasEnumerator;
     $code .= ");\n";
 
     if ($indexedGetterfunction && !$hasCustomIndexedGetter) {
         my $returnType = $indexedGetterfunction->signature->type;
+        my $nativeType = GetNativeType($returnType);
         my $methodName = $indexedGetterfunction->signature->name;
         $methodName ||= $indexedGetterfunction->signature->extendedAttributes->{"ImplementedAs"};
         AddToImplIncludes("bindings/v8/V8Collection.h");
-        my $jsValue = "";
-        my $nativeType = GetNativeType($returnType);
-        my $isNull = "";
-
-        if (IsRefPtrType($returnType)) {
-            AddToImplIncludes("V8$returnType.h");
-            $isNull = "!element";
-            $jsValue = NativeToJSValue($indexedGetterfunction->signature, "element.release()", "info.Holder()", "info.GetIsolate()", "info", "collection", "", "");
-        } else {
-            $isNull = "element.isNull()";
-            $jsValue = NativeToJSValue($indexedGetterfunction->signature, "element", "info.Holder()", "info.GetIsolate()");
-        }
+        my $nativeExpression = "element";
+        $nativeExpression .= ".release()" if (IsRefPtrType($returnType));
+        my $isNull = GetIsNullExpression($returnType, "element");
+        my $returnJSValueStatements = GetReturnJSValueStatements($returnType, $indexedGetterfunction->signature->extendedAttributes, $nativeExpression, "info.Holder()", "info.GetIsolate()", "info", "collection", "", "");
 
         $implementation{nameSpaceWebCore}->add(<<END);
 v8::Handle<v8::Value> ${v8ClassName}::indexedPropertyGetter(uint32_t index, const v8::AccessorInfo& info)
 {
     ASSERT(V8DOMWrapper::maybeDOMWrapper(info.Holder()));
     ${implClassName}* collection = toNative(info.Holder());
     $nativeType element = collection->$methodName(index);
-    if ($isNull)
+    if (${isNull})
         return v8Undefined();
-    return $jsValue;
+$returnJSValueStatements
 }
 
 END
     }
     return $code;
 }
 
 sub GenerateImplementationNamedPropertyGetter
 {
     my $interface = shift;
 
     my $subCode = "";
     my $interfaceName = $interface->name;
     my $implClassName = GetImplClassName($interface);
     my $v8ClassName = GetV8ClassName($interface);
 
     my $namedGetterFunction = GetNamedGetterFunction($interface);
     my $hasCustomNamedGetter = $interface->extendedAttributes->{"CustomNamedGetter"};
 
     if ($namedGetterFunction && !$hasCustomNamedGetter) {
+        $subCode .= <<END;
+    desc->InstanceTemplate()->SetNamedPropertyHandler(${v8ClassName}::namedPropertyGetter, 0, 0, 0, 0);
+END
         my $returnType = $namedGetterFunction->signature->type;
+        my $nativeType = GetNativeType($namedGetterFunction->signature->type);
         my $methodName = $namedGetterFunction->signature->name;
         $methodName ||= $namedGetterFunction->signature->extendedAttributes->{"ImplementedAs"};
         AddToImplIncludes("bindings/v8/V8Collection.h");
-        $subCode .= <<END;
-    desc->InstanceTemplate()->SetNamedPropertyHandler(${v8ClassName}::namedPropertyGetter, 0, 0, 0, 0);
-END
-        my $jsValue = "";
-        my $nativeType = GetNativeType($returnType);
-        my $isNull = "";
-
-        if (IsRefPtrType($returnType)) {
-            AddToImplIncludes("V8$returnType.h");
-            $isNull = "!element";
-            $jsValue = NativeToJSValue($namedGetterFunction->signature, "element.release()", "info.Holder()", "info.GetIsolate()", "info", "collection", "", "");
-        } else {
-            $isNull = "element.isNull()";
-            $jsValue = NativeToJSValue($namedGetterFunction->signature, "element", "info.Holder()", "info.GetIsolate()");
-        }
+        my $nativeExpression = "element";
+        $nativeExpression .= ".release()" if (IsRefPtrType($returnType));
+        my $isNull = GetIsNullExpression($returnType, "element");
+        my $returnJSValueStatements = GetReturnJSValueStatements($returnType, $namedGetterFunction->signature->extendedAttributes, $nativeExpression, "info.Holder()", "info.GetIsolate()", "info", "collection", "", "");
 
         $implementation{nameSpaceWebCore}->add(<<END);
 v8::Handle<v8::Value> ${v8ClassName}::namedPropertyGetter(v8::Local<v8::String> name, const v8::AccessorInfo& info)
 {
     if (!info.Holder()->GetRealNamedPropertyInPrototypeChain(name).IsEmpty())
         return v8Undefined();
     if (info.Holder()->HasRealNamedCallbackProperty(name))
         return v8Undefined();
 
     ASSERT(V8DOMWrapper::maybeDOMWrapper(info.Holder()));
     ${implClassName}* collection = toNative(info.Holder());
     AtomicString propertyName = toWebCoreAtomicString(name);
     ${nativeType} element = collection->${methodName}(propertyName);
     if (${isNull})
         return v8Undefined();
-    return ${jsValue};
+$returnJSValueStatements
 }
 
 END
     }
 
     if ($hasCustomNamedGetter) {
         my $hasCustomNamedSetter = $interface->extendedAttributes->{"CustomNamedSetter"};
         my $hasDeleter = $interface->extendedAttributes->{"CustomDeleteProperty"};
         my $hasEnumerator = $interface->extendedAttributes->{"CustomEnumerateProperty"};
         my $setOn = "Instance";
@@ skipping 899 matching lines @@
             $code .= "        return true;\n\n";
             $code .= "    v8::HandleScope handleScope;\n\n";
             $code .= "    v8::Handle<v8::Context> v8Context = toV8Context(scriptExecutionContext(), m_world.get());\n";
             $code .= "    if (v8Context.IsEmpty())\n";
             $code .= "        return true;\n\n";
             $code .= "    v8::Context::Scope scope(v8Context);\n\n";
 
             @args = ();
             foreach my $param (@params) {
                 my $paramName = $param->name;
-                $code .= "    v8::Handle<v8::Value> ${paramName}Handle = " . NativeToJSValue($param, $paramName, "v8::Handle<v8::Object>()", "v8Context->GetIsolate()", "") . ";\n";
+                $code .= "    v8::Handle<v8::Value> ${paramName}Handle = " . NativeToJSValue($param->type, $param->extendedAttributes, $paramName, "v8::Handle<v8::Object>()", "v8Context->GetIsolate()", "") . ";\n";
                 $code .= "    if (${paramName}Handle.IsEmpty()) {\n";
                 $code .= "        if (!isScriptControllerTerminating())\n";
                 $code .= "            CRASH();\n";
                 $code .= "        return true;\n";
                 $code .= "    }\n";
                 push(@args, "        ${paramName}Handle");
             }
 
             if (scalar(@args) > 0) {
                 $code .= "\n    v8::Handle<v8::Value> argv[] = {\n";
@@ skipping 352 matching lines @@
     # If the implementing class is a POD type, commit changes
     if (IsSVGTypeNeedingTearOff($interfaceName) and not $interfaceName =~ /List$/) {
         $code .= $indent . "wrapper->commitChange();\n";
     }
 
     $return .= ".release()" if ($returnIsRef);
 
     my $nativeValue;
     # FIXME: Update for all ScriptWrappables.
     if (IsDOMNodeType($interfaceName)) {
-        $nativeValue = NativeToJSValue($function->signature, $return, "args.Holder()", "args.GetIsolate()", "args", "imp", "ReturnUnsafeHandle", $forMainWorldSuffix);
+        $nativeValue = NativeToJSValue($function->signature->type, $function->signature->extendedAttributes, $return, "args.Holder()", "args.GetIsolate()", "args", "imp", "ReturnUnsafeHandle", $forMainWorldSuffix);
     } else {
-        $nativeValue = NativeToJSValue($function->signature, $return, "args.Holder()", "args.GetIsolate()", 0, 0, "ReturnUnsafeHandle", $forMainWorldSuffix);
+        $nativeValue = NativeToJSValue($function->signature->type, $function->signature->extendedAttributes, $return, "args.Holder()", "args.GetIsolate()", 0, 0, "ReturnUnsafeHandle", $forMainWorldSuffix);
     }
 
     $code .= $indent . "return " . $nativeValue . ";\n";
 
     return $code;
 }
 
 sub GetNativeTypeFromSignature
 {
     my $signature = shift;
@@ skipping 54 matching lines @@
     return "double" if $type eq "Date";
     return "ScriptValue" if $type eq "any";
     return "Dictionary" if $type eq "Dictionary";
 
     return "RefPtr<DOMStringList>" if $type eq "DOMStringList";
     return "RefPtr<MediaQueryListListener>" if $type eq "MediaQueryListListener";
     return "RefPtr<NodeFilter>" if $type eq "NodeFilter";
     return "RefPtr<SerializedScriptValue>" if $type eq "SerializedScriptValue";
     return "RefPtr<XPathNSResolver>" if $type eq "XPathNSResolver";
 
+    # Union type
+    if (ref $type) {
+        my $types = $type->unionType->unionMemberTypes;
+        die "Currently only 2 values of non-union type is supported as union type.\n" unless scalar(@$types)==2 && scalar(grep {ref $_} @$types)==0;

[haraken, 2013/05/15 12:09:43]

Nit: 'scalar(@$types) == 2' would be enough in practice. (For correctness, you
need to check a lot of more things, such as whether a given type is a RefPtr)

+        return "WTF::UnionType2<" . (join ", ", @$types) . ">";
+    }
+
     # We need to check [ImplementedBy] extended attribute for wrapper types.
     if (IsWrapperType($type)) {
         my $interface = ParseInterface($type);
         my $implClassName = GetImplClassName($interface);
         return $isParameter ? "${implClassName}*" : "RefPtr<${implClassName}>";
     }
     return "RefPtr<${type}>" if IsRefPtrType($type) and not $isParameter;
 
     my $arrayType = GetArrayType($type);
     my $sequenceType = GetSequenceType($type);
@@ skipping 308 matching lines @@
     return 1 if $type =~ /^SVG.*Element$/;
 
     return 1 if $type eq 'TestNode';
 
     return 0;
 }
 
 
 sub NativeToJSValue
 {
-    my $signature = shift;
-    my $value = shift;
+    my $type = shift;
+    my $extendedAttributes = shift;
+    my $value = shift; # expression of native value

[haraken, 2013/05/15 12:09:43]

$value => $nativeValue

     my $getCreationContext = shift;
     my $getIsolate = shift;
     die "An Isolate is mandatory for native value => JS value conversion." unless $getIsolate;
     my $getHolderContainer = shift;
     my $getHolderContainerArg = $getHolderContainer ? ", $getHolderContainer" : "";
     my $getScriptWrappable = shift;
     my $getScriptWrappableArg = $getScriptWrappable ? ", $getScriptWrappable" : "";
     my $returnHandleType = shift;
     my $returnHandleTypeArg = $returnHandleType ? ", $returnHandleType" : "";
     my $forMainWorldSuffix = shift;
 
-    my $type = $signature->type;
+    # Union type
+    if (ref $type) {
+        my $types = $type->unionType->unionMemberTypes;
+        die "JSValue of UnionType can not be obtained as expression. use GetCreateJSValueStatements() instead.\n";
+    }
 
     return "v8Boolean($value, $getIsolate)" if $type eq "boolean";
     return "v8Undefined()" if $type eq "void";     # equivalent to v8Undefined()
 
     # HTML5 says that unsigned reflected attributes should be in the range
     # [0, 2^31). When a value isn't in this range, a default value (or 0)
     # should be returned instead.
-    if ($signature->extendedAttributes->{"Reflect"} and ($type eq "unsigned long" or $type eq "unsigned short")) {
+    if ($extendedAttributes->{"Reflect"} and ($type eq "unsigned long" or $type eq "unsigned short")) {
         $value =~ s/getUnsignedIntegralAttribute/getIntegralAttribute/g;
         return "v8UnsignedInteger(std::max(0, " . $value . "), $getIsolate)";
     }
 
     # For all the types where we use 'int' as the representation type,
     # we use v8Integer() which has a fast small integer conversion check.
     my $nativeType = GetNativeType($type);
     return "v8Integer($value, $getIsolate)" if $nativeType eq "int";
     return "v8UnsignedInteger($value, $getIsolate)" if $nativeType eq "unsigned";
 
     return "v8DateOrNull($value, $getIsolate)" if $type eq "Date";
     # long long and unsigned long long are not representable in ECMAScript.
     return "v8::Number::New(static_cast<double>($value))" if $type eq "long long" or $type eq "unsigned long long" or $type eq "DOMTimeStamp";
     return "v8::Number::New($value)" if IsPrimitiveType($type);
     return "$value.v8Value()" if $nativeType eq "ScriptValue";
 
     if ($type eq "DOMString" or IsEnumType($type)) {
-        my $conv = $signature->extendedAttributes->{"TreatReturnedNullStringAs"};
+        my $conv = $extendedAttributes->{"TreatReturnedNullStringAs"};
         if (defined $conv) {
             return "v8StringOrNull($value, $getIsolate$returnHandleTypeArg)" if $conv eq "Null";
             return "v8StringOrUndefined($value, $getIsolate$returnHandleTypeArg)" if $conv eq "Undefined";
 
             die "Unknown value for TreatReturnedNullStringAs extended attribute";
         }
         return "v8String($value, $getIsolate$returnHandleTypeArg)";
     }
 
     my $arrayType = GetArrayType($type);
@@ skipping 308 matching lines @@
 
 sub IsRefPtrType
 {
     my $type = shift;
 
     return 0 if IsPrimitiveType($type);
     return 0 if GetArrayType($type);
     return 0 if GetSequenceType($type);
     return 0 if $type eq "DOMString";
     return 0 if IsEnumType($type);
+    return 0 if ref $type; # Union
 
     return 1;
 }
 
 sub GetSVGTypeNeedingTearOff
 {
     my $type = shift;
 
     return $svgTypeNeedingTearOff{$type} if exists $svgTypeNeedingTearOff{$type};
     return undef;
@@ skipping 326 matching lines @@
         if ($currentInterface->extendedAttributes->{$extendedAttribute}) {
             $found = 1;
         }
         return 1 if $found;
     }, 0);
 
     return $found;
 }
 
 1;