Changeset 52956 in webkit for trunk/JavaScriptCore/runtime/JSByteArray.cpp

Timestamp:

Jan 7, 2010, 4:15:05 PM (15 years ago)

Author:

[email protected]

Message:

Reviewed by Geoffrey Garen.

​https://bugs.webkit.org/show_bug.cgi?id=33057
REGRESSION(r49365): typeof(xhr.responseText) != "string" in Windows

<rdar://problem/7296920> REGRESSION: WebKit fails to start PeaceKeeper benchmark

Test: fast/js/webcore-string-comparison.html

In r49365, some code was moved from JSString.cpp to JSString.h, and as a result, WebCore
got a way to directly instantiate JSStrings over DLL borders. Since vftable for JSString was
not exported, objects created from WebCore got a different vptr, and JavaScriptCore
optimizations that relied on vptr of all JSString objects being equal failed.

• config.h: Added a JS_EXPORTCLASS macro for exporting classes. It's currently the same as JS_EXPORTDATA, but it clearly needed a new name.

• runtime/InitializeThreading.cpp: (JSC::initializeThreadingOnce):
• runtime/JSGlobalData.cpp: (JSC::JSGlobalData::storeVPtrs): (JSC::JSGlobalData::JSGlobalData): (JSC::JSGlobalData::createNonDefault): (JSC::JSGlobalData::create): (JSC::JSGlobalData::sharedInstance):
• runtime/JSGlobalData.h: Store vptrs just once, no need to repeatedly pick and copy them. This makes it possible to assert vptr correctness in object destructors (which don't have access to JSGlobalData, and even Heap::heap(this) will fail for fake objects created from storeVPtrs()).

• runtime/JSArray.cpp: (JSC::JSArray::~JSArray): Assert that vptr is what we expect it to be. It's important to assert in destructor, because MSVC changes the vptr after constructor is invoked.
• runtime/JSByteArray.cpp: (JSC::JSByteArray::~JSByteArray): Ditto.
• runtime/JSByteArray.h: Ditto.
• runtime/JSFunction.h: Ditto.
• runtime/JSFunction.cpp: (JSC::JSFunction::~JSFunction): Ditto.

• runtime/JSCell.h: (JSC::JSCell::setVPtr): Added a method to substitute vptr for another one.

• runtime/JSString.h: Export JSString class together with its vftable, and tell other libraries tp import it. This is needed on platforms that have a separate JavaScriptCore dynamic library - and on Mac, we already did the export via JavaScriptCore.exp. (JSC::JSString::~JSString): Assert tha vptr is what we expect it to be. (JSC::fixupVPtr): Store a previously saved primary vftable pointer (do nothing if building JavaScriptCore itself). (JSC::jsSingleCharacterString): Call fixupVPtr in case this is call across DLL boundary. (JSC::jsSingleCharacterSubstring): Ditto. (JSC::jsNontrivialString): Ditto. (JSC::jsString): Ditto. (JSC::jsSubstring): Ditto. (JSC::jsOwnedString): Ditto.

• JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.def: Export the new static JSGlobalData members that are used in WebCore via inline functions.

File:

• trunk/JavaScriptCore/runtime/JSByteArray.cpp (modified) (1 diff)

trunk/JavaScriptCore/runtime/JSByteArray.cpp

@@ -43 +43 @@
     putDirect(exec->globalData().propertyNames->length, jsNumber(exec, m_storage->length()), ReadOnly | DontDelete);
 }
-    
+
+#if !ASSERT_DISABLED
+JSByteArray::~JSByteArray()
+{
+    ASSERT(vptr() == JSGlobalData::jsByteArrayVPtr);
+}
+#endif
+
+
 PassRefPtr<Structure> JSByteArray::createStructure(JSValue prototype)
 {