Support IDL attributes limited to only known values.

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 1486 matching lines @@
         }
         $code .= <<END;
     ${implClassName}* imp = ${v8ClassName}::toNative(holder);
 END
     } else {
         my $reflect = $attribute->extendedAttributes->{"Reflect"};
         my $url = $attribute->extendedAttributes->{"URL"};
         if ($reflect && !$url && InheritsInterface($interface, "Node") && $attrType eq "DOMString") {
             # Generate super-compact call for regular attribute getter:
             my ($functionName, @arguments) = GetterExpression($interfaceName, $attribute);
+            my $getterExpression = "imp->${functionName}(" . join(", ", @arguments) . ")";
             $code .= "    Element* imp = V8Element::toNative(info.Holder());\n";
-            $code .= "    v8SetReturnValueString(info, imp->${functionName}(" . join(", ", @arguments) . "), info.GetIsolate());\n";
+            if ($attribute->extendedAttributes->{"ReflectOnly"}) {
+                $code .= "    String resultValue = ${getterExpression};\n";
+                $code .= GenerateReflectOnlyCheck($attribute->extendedAttributes->{"ReflectOnly"}, "    ");
+                $getterExpression = "resultValue";
+            }
+            $code .= "    v8SetReturnValueString(info, ${getterExpression}, info.GetIsolate());\n";
             $code .= "}\n";
             $code .= "#endif // ${conditionalString}\n" if $conditionalString;
             $code .= "\n";
             $implementation{nameSpaceInternal}->add($code);
             return;
             # Skip the rest of the function!
         }
         my $imp = 0;
         if ($attrCached) {
             $imp = 1;
@@ skipping 4170 matching lines @@
         return "${indent}v8SetReturnValue(${getCallbackInfo}, v8DateOrNull($nativeValue, $getIsolate));" if $isReturnValue;
         return "$indent$receiver v8DateOrNull($nativeValue, $getIsolate);"
     }
 
     # long long and unsigned long long are not representable in ECMAScript.
     if ($type eq "long long" or $type eq "unsigned long long" or $type eq "DOMTimeStamp") {
         return "${indent}v8SetReturnValue(${getCallbackInfo}, static_cast<double>($nativeValue));" if $isReturnValue;
         return "$indent$receiver v8::Number::New($getIsolate, static_cast<double>($nativeValue));";
     }
 
+    if ($type eq "DOMString" && $extendedAttributes->{"ReflectOnly"}) {
+        my $code = "${indent}String resultValue = ${nativeValue};\n";
+        $code .= GenerateReflectOnlyCheck($extendedAttributes->{"ReflectOnly"}, ${indent});
+        return "${code}${indent}v8SetReturnValueString(${getCallbackInfo}, resultValue, $getIsolate);" if $isReturnValue;
+        return "${code}$indent$receiver resultValue";
+    }
+
     my $conv = $extendedAttributes->{"TreatReturnedNullStringAs"};
     if (($type eq "DOMString" || IsEnumType($type)) && $isReturnValue) {
         my $functionSuffix = "";
         if (defined $conv) {
             if ($conv eq "Null") {
                 $functionSuffix = "OrNull";
             } elsif ($conv eq "Undefined") {
                 $functionSuffix = "OrUndefined";
             } else {
                 die "Unknown value for TreatReturnedNullStringAs extended attribute";
@@ skipping 527 matching lines @@
                 my $implementedByImplName = GetImplNameFromImplementedBy($constant->extendedAttributes->{"ImplementedBy"});
                 push(@checks, "    COMPILE_ASSERT($value == " . $implementedByImplName . "::$name, TheValueOf${implClassName}_${name}DoesntMatchWithImplementation);\n");
             } else {
                 push(@checks, "    COMPILE_ASSERT($value == ${implClassName}::$name, TheValueOf${implClassName}_${name}DoesntMatchWithImplementation);\n");
             }
         }
     }
     return @checks;
 }
 
+sub GenerateReflectOnlyCheck
+{
+    my $knownValueString = shift;
+    my $indent = shift;
+
+    my @knownValues = split(quotemeta("|"), $knownValueString);
+
+    # Attribute is limited to only known values: check that the attribute
+    # value is one of those..and if not, set it to the empty string.
+    # ( http://www.whatwg.org/specs/web-apps/current-work/#limited-to-only-known-values )
+    #
+    AddToImplIncludes("wtf/text/WTFString.h");

[haraken, 2014/01/06 13:13:02]

This won't be needed.

[sof, 2014/01/06 13:45:33]

Done.

+    my @normalizeAttributeCode = ();
+    my $code = "";
+    my $prefix = "";
+    foreach my $knownValue (@knownValues) {
+        push(@normalizeAttributeCode, "${indent}${prefix}if (equalIgnoringCase(resultValue, \"$knownValue\")) {");
+        push(@normalizeAttributeCode, "${indent}        resultValue = \"$knownValue\";");
+        if (!$prefix) {
+            $prefix = "    } else ";
+        }
+    }
+    my $normalizeAttributeValue = join("\n", @normalizeAttributeCode);
+    $code .= <<END;
+${indent}if (!resultValue.isEmpty()) {

[haraken, 2014/01/06 13:13:02]

This empty check won't be needed.

[sof, 2014/01/06 13:15:56]

It is useful to check for early though (rather than spin through N names & have
it bottom out in the unknown value case.)

[sof, 2014/01/06 13:45:33]

Done.

+${indent}${normalizeAttributeValue}
+${indent}    } else {
+${indent}        resultValue = "";
+${indent}    }
+${indent}}
+END
+        return "${code}";
+}
+
 sub ExtendedAttributeContains
 {
     my $extendedAttributeValue = shift;
     return 0 unless $extendedAttributeValue;
     my $keyword = shift;
 
     my @extendedAttributeValues = split /\s*(\&|\|)\s*/, $extendedAttributeValue;
     return grep { $_ eq $keyword } @extendedAttributeValues;
 }
 
@@ skipping 51 matching lines @@
 
     foreach my $parameter (@{$function->parameters}) {
         if ($parameter->type eq "SerializedScriptValue") {
             return 1;
         }
     }
     return 0;
 }
 
 1;