Changeset 95205 in webkit

Timestamp:

Sep 15, 2011 11:47:20 AM (13 years ago)

Author:

barraclough@apple.com

Message:

devirtualize preventExtensions
​https://bugs.webkit.org/show_bug.cgi?id=68176

Reviewed by Oliver Hunt.

This is virtual due to problems in JSFunction putting the prototype
property, but we can fix this problem a different way, just setting
the checkReadOnly flag to false in the put.

• runtime/JSFunction.cpp:

(JSC::JSFunction::getOwnPropertySlot):

• runtime/JSFunction.h:
• runtime/JSObject.h:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/JSFunction.cpp (modified) (2 diffs)
• runtime/JSFunction.h (modified) (1 diff)
• runtime/JSObject.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-09-15  Gavin Barraclough  <barraclough@apple.com>
+
+        devirtualize preventExtensions
+        https://bugs.webkit.org/show_bug.cgi?id=68176
+
+        Reviewed by Oliver Hunt.
+
+        This is virtual due to problems in JSFunction putting the prototype
+        property, but we can fix this problem a different way, just setting
+        the checkReadOnly flag to false in the put.
+
+        * runtime/JSFunction.cpp:
+        (JSC::JSFunction::getOwnPropertySlot):
+        * runtime/JSFunction.h:
+        * runtime/JSObject.h:
+
 2011-09-15  Geoffrey Garen  <ggaren@apple.com>
 

trunk/Source/JavaScriptCore/runtime/JSFunction.cpp

@@ -176 +176 @@
 }
 
-static inline WriteBarrierBase<Unknown>* createPrototypeProperty(JSGlobalData& globalData, JSGlobalObject* globalObject, JSFunction* function)
-{
-    ASSERT(!function->isHostFunction());
-
-    ExecState* exec = globalObject->globalExec();
-    if (WriteBarrierBase<Unknown>* location = function->getDirectLocation(globalData, exec->propertyNames().prototype))
-        return location;
-    JSObject* prototype = constructEmptyObject(exec, globalObject->emptyObjectStructure());
-    prototype->putDirect(globalData, exec->propertyNames().constructor, function, DontEnum);
-    function->putDirect(globalData, exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
-    return function->getDirectLocation(exec->globalData(), exec->propertyNames().prototype);
-}
-
-void JSFunction::preventExtensions(JSGlobalData& globalData)
-{
-    if (!isHostFunction())
-        createPrototypeProperty(globalData, scope()->globalObject.get(), this);
-    JSObject::preventExtensions(globalData);
-}
-
 bool JSFunction::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
 {
@@ -204 +184 @@
         WriteBarrierBase<Unknown>* location = getDirectLocation(exec->globalData(), propertyName);
 
-        if (!location)
-            location = createPrototypeProperty(exec->globalData(), scope()->globalObject.get(), this);
+        if (!location) {
+            JSObject* prototype = constructEmptyObject(exec, globalObject()->emptyObjectStructure());
+            prototype->putDirect(exec->globalData(), exec->propertyNames().constructor, this, DontEnum);
+            PutPropertySlot slot;
+            putDirect(exec->globalData(), exec->propertyNames().prototype, prototype, DontDelete | DontEnum, false, slot);
+            location = getDirectLocation(exec->globalData(), exec->propertyNames().prototype);
+        }
 
         slot.setValue(this, location->get(), offsetForLocation(location));

trunk/Source/JavaScriptCore/runtime/JSFunction.h

@@ -149 +149 @@
         bool isHostFunctionNonInline() const;
 
-        virtual void preventExtensions(JSGlobalData&);
         virtual bool getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&);
         virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);

trunk/Source/JavaScriptCore/runtime/JSObject.h

@@ -212 +212 @@
         void seal(JSGlobalData&);
         void freeze(JSGlobalData&);
-        virtual void preventExtensions(JSGlobalData&);
+        void preventExtensions(JSGlobalData&);
         bool isSealed(JSGlobalData& globalData) { return m_structure->isSealed(globalData); }
         bool isFrozen(JSGlobalData& globalData) { return m_structure->isFrozen(globalData); }