Bug 838691 part 1. Add support in Prefable for calling a function to determine whether a property should be exposed in a WebIDL binding. r=peterv

dom/bindings/BindingUtils.cpp

@@ -185,7 +185,7 @@ DefinePrefable(JSContext* cx, JSObject* obj, Prefable<T>* props)
   MOZ_ASSERT(props->specs);
   do {
     // Define if enabled
-    if (props->enabled) {
+    if (props->isEnabled(cx, obj)) {
       if (!Define(cx, obj, props->specs)) {
         return false;
       }
@@ -698,12 +698,12 @@ XrayResolveOwnProperty(JSContext* cx, JSObject* wrapper, JSObject* obj, jsid id,
 }
 
 static bool
-XrayResolveAttribute(JSContext* cx, JSObject* wrapper, jsid id,
+XrayResolveAttribute(JSContext* cx, JSObject* wrapper, JSObject* obj, jsid id,
                      Prefable<JSPropertySpec>* attributes, jsid* attributeIds,
                      JSPropertySpec* attributeSpecs, JSPropertyDescriptor* desc)
 {
   for (; attributes->specs; ++attributes) {
-    if (attributes->enabled) {
+    if (attributes->isEnabled(cx, obj)) {
       // Set i to be the index into our full list of ids/specs that we're
       // looking at now.
       size_t i = attributes->specs - attributeSpecs;
@@ -747,7 +747,7 @@ XrayResolveAttribute(JSContext* cx, JSObject* wrapper, jsid id,
 }
 
 static bool
-XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
+XrayResolveProperty(JSContext* cx, JSObject* wrapper, JSObject* obj, jsid id,
                     JSPropertyDescriptor* desc, DOMObjectType type,
                     const NativeProperties* nativeProperties)
 {
@@ -766,7 +766,7 @@ XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
   if (methods) {
     Prefable<JSFunctionSpec>* method;
     for (method = methods; method->specs; ++method) {
-      if (method->enabled) {
+      if (method->isEnabled(cx, obj)) {
         // Set i to be the index into our full list of ids/specs that we're
         // looking at now.
         size_t i = method->specs - methodsSpecs;
@@ -795,7 +795,7 @@ XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
 
   if (type == eInterface) {
     if (nativeProperties->staticAttributes) {
-      if (!XrayResolveAttribute(cx, wrapper, id,
+      if (!XrayResolveAttribute(cx, wrapper, obj, id,
                                 nativeProperties->staticAttributes,
                                 nativeProperties->staticAttributeIds,
                                 nativeProperties->staticAttributeSpecs, desc)) {
@@ -807,7 +807,7 @@ XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
     }
   } else {
     if (nativeProperties->attributes) {
-      if (!XrayResolveAttribute(cx, wrapper, id,
+      if (!XrayResolveAttribute(cx, wrapper, obj, id,
                                 nativeProperties->attributes,
                                 nativeProperties->attributeIds,
                                 nativeProperties->attributeSpecs, desc)) {
@@ -818,7 +818,7 @@ XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
       }
     }
     if (nativeProperties->unforgeableAttributes) {
-      if (!XrayResolveAttribute(cx, wrapper, id,
+      if (!XrayResolveAttribute(cx, wrapper, obj, id,
                                 nativeProperties->unforgeableAttributes,
                                 nativeProperties->unforgeableAttributeIds,
                                 nativeProperties->unforgeableAttributeSpecs,
@@ -834,7 +834,7 @@ XrayResolveProperty(JSContext* cx, JSObject* wrapper, jsid id,
   if (nativeProperties->constants) {
     Prefable<ConstantSpec>* constant;
     for (constant = nativeProperties->constants; constant->specs; ++constant) {
-      if (constant->enabled) {
+      if (constant->isEnabled(cx, obj)) {
         // Set i to be the index into our full list of ids/specs that we're
         // looking at now.
         size_t i = constant->specs - nativeProperties->constantSpecs;
@@ -901,7 +901,7 @@ XrayResolveNativeProperty(JSContext* cx, JSObject* wrapper,
     nativePropertyHooks->mNativeProperties;
 
   if (nativeProperties.regular &&
-      !XrayResolveProperty(cx, wrapper, id, desc, type,
+      !XrayResolveProperty(cx, wrapper, obj, id, desc, type,
                            nativeProperties.regular)) {
     return false;
   }
@@ -909,7 +909,7 @@ XrayResolveNativeProperty(JSContext* cx, JSObject* wrapper,
   if (!desc->obj &&
       nativeProperties.chromeOnly &&
       xpc::AccessCheck::isChrome(js::GetObjectCompartment(wrapper)) &&
-      !XrayResolveProperty(cx, wrapper, id, desc, type,
+      !XrayResolveProperty(cx, wrapper, obj, id, desc, type,
                            nativeProperties.chromeOnly)) {
     return false;
   }
@@ -951,12 +951,13 @@ XrayResolveNativeProperty(JSContext* cx, JSObject* wrapper, JSObject* obj,
 }
 
 bool
-XrayEnumerateAttributes(Prefable<JSPropertySpec>* attributes,
+XrayEnumerateAttributes(JSContext* cx, JSObject* wrapper, JSObject* obj,
+                        Prefable<JSPropertySpec>* attributes,
                         jsid* attributeIds, JSPropertySpec* attributeSpecs,
                         unsigned flags, JS::AutoIdVector& props)
 {
   for (; attributes->specs; ++attributes) {
-    if (attributes->enabled) {
+    if (attributes->isEnabled(cx, obj)) {
       // Set i to be the index into our full list of ids/specs that we're
       // looking at now.
       size_t i = attributes->specs - attributeSpecs;
@@ -973,7 +974,8 @@ XrayEnumerateAttributes(Prefable<JSPropertySpec>* attributes,
 }
 
 bool
-XrayEnumerateProperties(unsigned flags, JS::AutoIdVector& props,
+XrayEnumerateProperties(JSContext* cx, JSObject* wrapper, JSObject* obj,
+                        unsigned flags, JS::AutoIdVector& props,
                         DOMObjectType type,
                         const NativeProperties* nativeProperties)
 {
@@ -992,7 +994,7 @@ XrayEnumerateProperties(unsigned flags, JS::AutoIdVector& props,
   if (methods) {
     Prefable<JSFunctionSpec>* method;
     for (method = methods; method->specs; ++method) {
-      if (method->enabled) {
+      if (method->isEnabled(cx, obj)) {
         // Set i to be the index into our full list of ids/specs that we're
         // looking at now.
         size_t i = method->specs - methodsSpecs;
@@ -1009,7 +1011,8 @@ XrayEnumerateProperties(unsigned flags, JS::AutoIdVector& props,
 
   if (type == eInterface) {
     if (nativeProperties->staticAttributes &&
-        !XrayEnumerateAttributes(nativeProperties->staticAttributes,
+        !XrayEnumerateAttributes(cx, wrapper, obj,
+                                 nativeProperties->staticAttributes,
                                  nativeProperties->staticAttributeIds,
                                  nativeProperties->staticAttributeSpecs,
                                  flags, props)) {
@@ -1017,14 +1020,16 @@ XrayEnumerateProperties(unsigned flags, JS::AutoIdVector& props,
     }
   } else {
     if (nativeProperties->attributes &&
-        !XrayEnumerateAttributes(nativeProperties->attributes,
+        !XrayEnumerateAttributes(cx, wrapper, obj,
+                                 nativeProperties->attributes,
                                  nativeProperties->attributeIds,
                                  nativeProperties->attributeSpecs,
                                  flags, props)) {
       return false;
     }
     if (nativeProperties->unforgeableAttributes &&
-        !XrayEnumerateAttributes(nativeProperties->unforgeableAttributes,
+        !XrayEnumerateAttributes(cx, wrapper, obj,
+                                 nativeProperties->unforgeableAttributes,
                                  nativeProperties->unforgeableAttributeIds,
                                  nativeProperties->unforgeableAttributeSpecs,
                                  flags, props)) {
@@ -1035,7 +1040,7 @@ XrayEnumerateProperties(unsigned flags, JS::AutoIdVector& props,
   if (nativeProperties->constants) {
     Prefable<ConstantSpec>* constant;
     for (constant = nativeProperties->constants; constant->specs; ++constant) {
-      if (constant->enabled) {
+      if (constant->isEnabled(cx, obj)) {
         // Set i to be the index into our full list of ids/specs that we're
         // looking at now.
         size_t i = constant->specs - nativeProperties->constantSpecs;
@@ -1074,13 +1079,15 @@ XrayEnumerateNativeProperties(JSContext* cx, JSObject* wrapper,
     nativePropertyHooks->mNativeProperties;
 
   if (nativeProperties.regular &&
-      !XrayEnumerateProperties(flags, props, type, nativeProperties.regular)) {
+      !XrayEnumerateProperties(cx, wrapper, obj, flags, props, type,
+                               nativeProperties.regular)) {
     return false;
   }
 
   if (nativeProperties.chromeOnly &&
       xpc::AccessCheck::isChrome(js::GetObjectCompartment(wrapper)) &&
-      !XrayEnumerateProperties(flags, props, type, nativeProperties.chromeOnly)) {
+      !XrayEnumerateProperties(cx, wrapper, obj, flags, props, type,
+                               nativeProperties.chromeOnly)) {
     return false;
   }
 

dom/bindings/Codegen.py

@@ -1086,7 +1086,7 @@ class PropertyDefiner:
         specs = []
         prefableSpecs = []
 
-        prefableTemplate = '  { true, &%s[%d] }'
+        prefableTemplate = '  { true, nullptr, &%s[%d] }'
         prefCacheTemplate = '&%s[%d].enabled'
         def switchToPref(props, pref):
             # Remember the info about where our pref-controlled

dom/bindings/DOMJSClass.h

@@ -62,10 +62,22 @@ struct ConstantSpec
   JS::Value value;
 };
 
+typedef bool (*PropertyEnabled)(JSContext* cx, JSObject* global);
+
 template<typename T>
 struct Prefable {
+  inline bool isEnabled(JSContext* cx, JSObject* obj) {
+    return enabled &&
+      (!enabledFunc ||
+       enabledFunc(cx, js::GetGlobalForObjectCrossCompartment(obj)));
+  }
+
   // A boolean indicating whether this set of specs is enabled
   bool enabled;
+  // A function pointer to a function that can say the property is disabled
+  // even if "enabled" is set to true.  If the pointer is null the value of
+  // "enabled" is used as-is.
+  PropertyEnabled enabledFunc;
   // Array of specs, terminated in whatever way is customary for T.
   // Null to indicate a end-of-array for Prefable, when such an
   // indicator is needed.