Changeset 95167 in webkit for trunk/Source/JavaScriptCore/runtime/JSString.h

Timestamp:

Sep 14, 2011, 10:15:16 PM (14 years ago)

Author:

[email protected]

Message:

Make JSCell::toBoolean non-virtual
​https://bugs.webkit.org/show_bug.cgi?id=67727

Reviewed by Sam Weinig.

JSCell::toBoolean now manually performs the toBoolean check for objects and strings (where
before it was simply virtual and would crash if its implementation was called).
Its descendants in JSObject and JSString have also been made non-virtual. JSCell now
explicitly covers all cases of toBoolean, so having a virtual implementation of
JSCell::toBoolean is no longer necessary. This is part of a larger process of un-virtualizing JSCell.

• JavaScriptCore.exp:
• JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.def:
• runtime/JSCell.cpp:
• runtime/JSCell.h:
• runtime/JSNotAnObject.cpp:
• runtime/JSNotAnObject.h:
• runtime/JSObject.h:
• runtime/JSString.h:

(JSC::JSCell::toBoolean):
(JSC::JSValue::toBoolean):

• runtime/StringObjectThatMasqueradesAsUndefined.h:

File:

• trunk/Source/JavaScriptCore/runtime/JSString.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/runtime/JSString.h

@@ -63 +63 @@
     public:
         friend class JIT;
+        friend class JSCell;
         friend class JSGlobalData;
+        friend class JSValue;
         friend class SpecializedThunkJIT;
         friend struct ThunkHelpers;
@@ -495 +497 @@
         virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
         virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue& value);
-        virtual bool toBoolean(ExecState*) const;
+        bool toBoolean(ExecState*) const;
         virtual double toNumber(ExecState*) const;
         virtual JSObject* toObject(ExecState*, JSGlobalObject*) const;
@@ -681 +683 @@
     inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
 
+    inline bool JSCell::toBoolean(ExecState* exec) const
+    {
+        if (isString()) 
+            return static_cast<const JSString*>(this)->toBoolean(exec);
+        return !structure()->typeInfo().masqueradesAsUndefined();
+    }
+
     // --- JSValue inlines ----------------------------
+    
+    inline bool JSValue::toBoolean(ExecState* exec) const
+    {
+        if (isInt32())
+            return asInt32();
+        if (isDouble())
+            return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
+        if (isCell())
+            return asCell()->toBoolean(exec);
+        return isTrue(); // false, null, and undefined all convert to false.
+    }
 
     inline UString JSValue::toString(ExecState* exec) const