JavaScriptCore-584.tar.gz

[apple/javascriptcore.git] / runtime / JSString.h

diff --git a/runtime/JSString.h b/runtime/JSString.h
index e4baa73aba9809c7c753808f5fad107899304c40..af03025170e0e743bd4e1f671736eab4119362bf 100644 (file)
--- a/runtime/JSString.h
+++ b/runtime/JSString.h
@@ -23,10 +23,11 @@
 #ifndef JSString_h
 #define JSString_h
 
 #ifndef JSString_h
 #define JSString_h
 

-#include "CommonIdentifiers.h"

 #include "CallFrame.h"
 #include "CallFrame.h"

+#include "CommonIdentifiers.h"

 #include "Identifier.h"
 #include "JSNumberCell.h"
 #include "Identifier.h"
 #include "JSNumberCell.h"

+#include "PropertyDescriptor.h"

 #include "PropertySlot.h"
 
 namespace JSC {
 #include "PropertySlot.h"
 
 namespace JSC {


@@ -58,14 +59,117 @@ namespace JSC {
     JSString* jsOwnedString(JSGlobalData*, const UString&); 
     JSString* jsOwnedString(ExecState*, const UString&); 
 
     JSString* jsOwnedString(JSGlobalData*, const UString&); 
     JSString* jsOwnedString(ExecState*, const UString&); 
 

-    class JSString : public JSCell {
-        friend class JIT;
-        friend class Interpreter;
+    typedef void (*JSStringFinalizerCallback)(JSString*, void* context);
+    JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);

 
 

+    class JS_EXPORTCLASS JSString : public JSCell {

     public:
     public:

-        JSString(JSGlobalData* globalData, const UString& value)
+        friend class JIT;
+        friend class JSGlobalData;
+
+        // A Rope is a string composed of a set of substrings.
+        class Rope : public RefCounted<Rope> {
+        public:
+            // A Rope is composed from a set of smaller strings called Fibers.
+            // Each Fiber in a rope is either UString::Rep or another Rope.
+            class Fiber {
+            public:
+                Fiber() : m_value(0) {}
+                Fiber(UString::Rep* string) : m_value(reinterpret_cast<intptr_t>(string)) {}
+                Fiber(Rope* rope) : m_value(reinterpret_cast<intptr_t>(rope) | 1) {}
+
+                Fiber(void* nonFiber) : m_value(reinterpret_cast<intptr_t>(nonFiber)) {}
+
+                void deref()
+                {
+                    if (isRope())
+                        rope()->deref();
+                    else
+                        string()->deref();
+                }
+
+                Fiber& ref()
+                {
+                    if (isString())
+                        string()->ref();
+                    else
+                        rope()->ref();
+                    return *this;
+                }
+
+                unsigned refAndGetLength()
+                {
+                    if (isString()) {
+                        UString::Rep* rep = string();
+                        return rep->ref()->size();
+                    } else {
+                        Rope* r = rope();
+                        r->ref();
+                        return r->stringLength();
+                    }
+                }
+
+                bool isRope() { return m_value & 1; }
+                Rope* rope() { return reinterpret_cast<Rope*>(m_value & ~1); }
+                bool isString() { return !isRope(); }
+                UString::Rep* string() { return reinterpret_cast<UString::Rep*>(m_value); }
+
+                void* nonFiber() { return reinterpret_cast<void*>(m_value); }
+            private:
+                intptr_t m_value;
+            };
+
+            // Creates a Rope comprising of 'ropeLength' Fibers.
+            // The Rope is constructed in an uninitialized state - initialize must be called for each Fiber in the Rope.
+            static PassRefPtr<Rope> createOrNull(unsigned ropeLength)
+            {
+                void* allocation;
+                if (tryFastMalloc(sizeof(Rope) + (ropeLength - 1) * sizeof(Fiber)).getValue(allocation))
+                    return adoptRef(new (allocation) Rope(ropeLength));
+                return 0;
+            }
+
+            ~Rope();
+            void destructNonRecursive();
+
+            void append(unsigned &index, Fiber& fiber)
+            {
+                m_fibers[index++] = fiber;
+                m_stringLength += fiber.refAndGetLength();
+            }
+            void append(unsigned &index, const UString& string)
+            {
+                UString::Rep* rep = string.rep();
+                m_fibers[index++] = Fiber(rep);
+                m_stringLength += rep->ref()->size();
+            }
+            void append(unsigned& index, JSString* jsString)
+            {
+                if (jsString->isRope()) {
+                    for (unsigned i = 0; i < jsString->m_ropeLength; ++i)
+                        append(index, jsString->m_fibers[i]);
+                } else
+                    append(index, jsString->string());
+            }
+
+            unsigned ropeLength() { return m_ropeLength; }
+            unsigned stringLength() { return m_stringLength; }
+            Fiber& fibers(unsigned index) { return m_fibers[index]; }
+
+        private:
+            Rope(unsigned ropeLength) : m_ropeLength(ropeLength), m_stringLength(0) {}
+            void* operator new(size_t, void* inPlace) { return inPlace; }
+            
+            unsigned m_ropeLength;
+            unsigned m_stringLength;
+            Fiber m_fibers[1];
+        };
+
+        ALWAYS_INLINE JSString(JSGlobalData* globalData, const UString& value)

             : JSCell(globalData->stringStructure.get())
             : JSCell(globalData->stringStructure.get())

+            , m_stringLength(value.size())

             , m_value(value)
             , m_value(value)

+            , m_ropeLength(0)

         {
             Heap::heap(this)->reportExtraMemoryCost(value.cost());
         }
         {
             Heap::heap(this)->reportExtraMemoryCost(value.cost());
         }


@@ -73,34 +177,168 @@ namespace JSC {
         enum HasOtherOwnerType { HasOtherOwner };
         JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
             : JSCell(globalData->stringStructure.get())
         enum HasOtherOwnerType { HasOtherOwner };
         JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
             : JSCell(globalData->stringStructure.get())

+            , m_stringLength(value.size())

             , m_value(value)
             , m_value(value)

+            , m_ropeLength(0)

         {
         }
         JSString(JSGlobalData* globalData, PassRefPtr<UString::Rep> value, HasOtherOwnerType)
             : JSCell(globalData->stringStructure.get())
         {
         }
         JSString(JSGlobalData* globalData, PassRefPtr<UString::Rep> value, HasOtherOwnerType)
             : JSCell(globalData->stringStructure.get())

+            , m_stringLength(value->size())

             , m_value(value)
             , m_value(value)

+            , m_ropeLength(0)

         {
         }
         {
         }

-        
-        const UString& value() const { return m_value; }
+        JSString(JSGlobalData* globalData, PassRefPtr<JSString::Rope> rope)
+            : JSCell(globalData->stringStructure.get())
+            , m_stringLength(rope->stringLength())
+            , m_ropeLength(1)
+        {
+            m_fibers[0] = rope.releaseRef();
+        }
+        // This constructor constructs a new string by concatenating s1 & s2.
+        // This should only be called with ropeLength <= 3.
+        JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, JSString* s2)
+            : JSCell(globalData->stringStructure.get())
+            , m_stringLength(s1->length() + s2->length())
+            , m_ropeLength(ropeLength)
+        {
+            ASSERT(ropeLength <= s_maxInternalRopeLength);
+            unsigned index = 0;
+            appendStringInConstruct(index, s1);
+            appendStringInConstruct(index, s2);
+            ASSERT(ropeLength == index);
+        }
+        // This constructor constructs a new string by concatenating s1 & s2.
+        // This should only be called with ropeLength <= 3.
+        JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, const UString& u2)
+            : JSCell(globalData->stringStructure.get())
+            , m_stringLength(s1->length() + u2.size())
+            , m_ropeLength(ropeLength)
+        {
+            ASSERT(ropeLength <= s_maxInternalRopeLength);
+            unsigned index = 0;
+            appendStringInConstruct(index, s1);
+            appendStringInConstruct(index, u2);
+            ASSERT(ropeLength == index);
+        }
+        // This constructor constructs a new string by concatenating s1 & s2.
+        // This should only be called with ropeLength <= 3.
+        JSString(JSGlobalData* globalData, unsigned ropeLength, const UString& u1, JSString* s2)
+            : JSCell(globalData->stringStructure.get())
+            , m_stringLength(u1.size() + s2->length())
+            , m_ropeLength(ropeLength)
+        {
+            ASSERT(ropeLength <= s_maxInternalRopeLength);
+            unsigned index = 0;
+            appendStringInConstruct(index, u1);
+            appendStringInConstruct(index, s2);
+            ASSERT(ropeLength == index);
+        }
+        // This constructor constructs a new string by concatenating v1, v2 & v3.
+        // This should only be called with ropeLength <= 3 ... which since every
+        // value must require a ropeLength of at least one implies that the length
+        // for each value must be exactly 1!
+        JSString(ExecState* exec, JSValue v1, JSValue v2, JSValue v3)
+            : JSCell(exec->globalData().stringStructure.get())
+            , m_stringLength(0)
+            , m_ropeLength(s_maxInternalRopeLength)
+        {
+            unsigned index = 0;
+            appendValueInConstructAndIncrementLength(exec, index, v1);
+            appendValueInConstructAndIncrementLength(exec, index, v2);
+            appendValueInConstructAndIncrementLength(exec, index, v3);
+            ASSERT(index == s_maxInternalRopeLength);
+        }
+
+        JSString(JSGlobalData* globalData, const UString& value, JSStringFinalizerCallback finalizer, void* context)
+            : JSCell(globalData->stringStructure.get())
+            , m_stringLength(value.size())
+            , m_value(value)
+            , m_ropeLength(0)
+        {
+            // nasty hack because we can't union non-POD types
+            m_fibers[0] = reinterpret_cast<void*>(reinterpret_cast<ptrdiff_t>(finalizer));
+            m_fibers[1] = context;
+            Heap::heap(this)->reportExtraMemoryCost(value.cost());
+        }
+
+        ~JSString()
+        {
+            ASSERT(vptr() == JSGlobalData::jsStringVPtr);
+            for (unsigned i = 0; i < m_ropeLength; ++i)
+                m_fibers[i].deref();
+
+            if (!m_ropeLength && m_fibers[0].nonFiber()) {
+                JSStringFinalizerCallback finalizer = reinterpret_cast<JSStringFinalizerCallback>(m_fibers[0].nonFiber());
+                finalizer(this, m_fibers[1].nonFiber());
+            }
+        }
+
+        const UString& value(ExecState* exec) const
+        {
+            if (isRope())
+                resolveRope(exec);
+            return m_value;
+        }
+        const UString tryGetValue() const
+        {
+            if (isRope())
+                UString();
+            return m_value;
+        }
+        unsigned length() { return m_stringLength; }

 
         bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
 
         bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);

+        bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);

 
 

-        bool canGetIndex(unsigned i) { return i < static_cast<unsigned>(m_value.size()); }
-        JSString* getIndex(JSGlobalData*, unsigned);
+        bool canGetIndex(unsigned i) { return i < m_stringLength; }
+        JSString* getIndex(ExecState*, unsigned);

 
 

-        static PassRefPtr<Structure> createStructure(JSValuePtr proto) { return Structure::create(proto, TypeInfo(StringType, NeedsThisConversion)); }
+        static PassRefPtr<Structure> createStructure(JSValue proto) { return Structure::create(proto, TypeInfo(StringType, OverridesGetOwnPropertySlot | NeedsThisConversion), AnonymousSlotCount); }

 
     private:
         enum VPtrStealingHackType { VPtrStealingHack };
         JSString(VPtrStealingHackType) 
             : JSCell(0)
 
     private:
         enum VPtrStealingHackType { VPtrStealingHack };
         JSString(VPtrStealingHackType) 
             : JSCell(0)

+            , m_ropeLength(0)

         {
         }
 
         {
         }
 

-        virtual JSValuePtr toPrimitive(ExecState*, PreferredPrimitiveType) const;
-        virtual bool getPrimitiveNumber(ExecState*, double& number, JSValuePtr& value);
+        void resolveRope(ExecState*) const;
+
+        void appendStringInConstruct(unsigned& index, const UString& string)
+        {
+            m_fibers[index++] = Rope::Fiber(string.rep()->ref());
+        }
+
+        void appendStringInConstruct(unsigned& index, JSString* jsString)
+        {
+            if (jsString->isRope()) {
+                for (unsigned i = 0; i < jsString->m_ropeLength; ++i)
+                    m_fibers[index++] = jsString->m_fibers[i].ref();
+            } else
+                appendStringInConstruct(index, jsString->string());
+        }
+
+        void appendValueInConstructAndIncrementLength(ExecState* exec, unsigned& index, JSValue v)
+        {
+            if (v.isString()) {
+                ASSERT(asCell(v)->isString());
+                JSString* s = static_cast<JSString*>(asCell(v));
+                ASSERT(s->ropeLength() == 1);
+                appendStringInConstruct(index, s);
+                m_stringLength += s->length();
+            } else {
+                UString u(v.toString(exec));
+                m_fibers[index++] = Rope::Fiber(u.rep()->ref());
+                m_stringLength += u.size();
+            }
+        }
+
+        virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
+        virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue& value);

         virtual bool toBoolean(ExecState*) const;
         virtual double toNumber(ExecState*) const;
         virtual JSObject* toObject(ExecState*) const;
         virtual bool toBoolean(ExecState*) const;
         virtual double toNumber(ExecState*) const;
         virtual JSObject* toObject(ExecState*) const;


@@ -113,13 +351,41 @@ namespace JSC {
         // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
         virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
         // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
         virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);

-
-        UString m_value;
+        virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
+
+        static const unsigned s_maxInternalRopeLength = 3;
+
+        // A string is represented either by a UString or a Rope.
+        unsigned m_stringLength;
+        mutable UString m_value;
+        mutable unsigned m_ropeLength;
+        mutable Rope::Fiber m_fibers[s_maxInternalRopeLength];
+
+        bool isRope() const { return m_ropeLength; }
+        UString& string() { ASSERT(!isRope()); return m_value; }
+        unsigned ropeLength() { return m_ropeLength ? m_ropeLength : 1; }
+
+        friend JSValue jsString(ExecState* exec, JSString* s1, JSString* s2);
+        friend JSValue jsString(ExecState* exec, const UString& u1, JSString* s2);
+        friend JSValue jsString(ExecState* exec, JSString* s1, const UString& u2);
+        friend JSValue jsString(ExecState* exec, Register* strings, unsigned count);
+        friend JSValue jsString(ExecState* exec, JSValue thisValue, const ArgList& args);
+        friend JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);

     };
 
     };
 

-    JSString* asString(JSValuePtr);
+    JSString* asString(JSValue);
+
+    // When an object is created from a different DLL, MSVC changes vptr to a "local" one right after invoking a constructor,
+    // see <http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212>.
+    // This breaks isJSString(), and we don't need that hack anyway, so we change vptr back to primary one.
+    // The below function must be called by any inline function that invokes a JSString constructor.
+#if COMPILER(MSVC) && !defined(BUILDING_JavaScriptCore)
+    inline JSString* fixupVPtr(JSGlobalData* globalData, JSString* string) { string->setVPtr(globalData->jsStringVPtr); return string; }
+#else
+    inline JSString* fixupVPtr(JSGlobalData*, JSString* string) { return string; }
+#endif

 
 

-    inline JSString* asString(JSValuePtr value)
+    inline JSString* asString(JSValue value)

     {
         ASSERT(asCell(value)->isString());
         return static_cast<JSString*>(asCell(value));
     {
         ASSERT(asCell(value)->isString());
         return static_cast<JSString*>(asCell(value));


@@ -134,7 +400,7 @@ namespace JSC {
     {
         if (c <= 0xFF)
             return globalData->smallStrings.singleCharacterString(globalData, c);
     {
         if (c <= 0xFF)
             return globalData->smallStrings.singleCharacterString(globalData, c);

-        return new (globalData) JSString(globalData, UString(&c, 1));
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(&c, 1)));

     }
 
     inline JSString* jsSingleCharacterSubstring(JSGlobalData* globalData, const UString& s, unsigned offset)
     }
 
     inline JSString* jsSingleCharacterSubstring(JSGlobalData* globalData, const UString& s, unsigned offset)


@@ -143,7 +409,7 @@ namespace JSC {
         UChar c = s.data()[offset];
         if (c <= 0xFF)
             return globalData->smallStrings.singleCharacterString(globalData, c);
         UChar c = s.data()[offset];
         if (c <= 0xFF)
             return globalData->smallStrings.singleCharacterString(globalData, c);

-        return new (globalData) JSString(globalData, UString::Rep::create(s.rep(), offset, 1));
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UString::Rep::create(s.rep(), offset, 1))));

     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)
     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)


@@ -151,19 +417,67 @@ namespace JSC {
         ASSERT(s);
         ASSERT(s[0]);
         ASSERT(s[1]);
         ASSERT(s);
         ASSERT(s[0]);
         ASSERT(s[1]);

-        return new (globalData) JSString(globalData, s);
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));

     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
     {
         ASSERT(s.size() > 1);
     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
     {
         ASSERT(s.size() > 1);

-        return new (globalData) JSString(globalData, s);
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));

     }
 
     }
 

-    inline JSString* JSString::getIndex(JSGlobalData* globalData, unsigned i)
+    inline JSString* JSString::getIndex(ExecState* exec, unsigned i)

     {
         ASSERT(canGetIndex(i));
     {
         ASSERT(canGetIndex(i));

-        return jsSingleCharacterSubstring(globalData, m_value, i);
+        return jsSingleCharacterSubstring(&exec->globalData(), value(exec), i);
+    }
+
+    inline JSString* jsString(JSGlobalData* globalData, const UString& s)
+    {
+        int size = s.size();
+        if (!size)
+            return globalData->smallStrings.emptyString(globalData);
+        if (size == 1) {
+            UChar c = s.data()[0];
+            if (c <= 0xFF)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
+    }
+
+    inline JSString* jsStringWithFinalizer(ExecState* exec, const UString& s, JSStringFinalizerCallback callback, void* context)
+    {
+        ASSERT(s.size() && (s.size() > 1 || s.data()[0] > 0xFF));
+        JSGlobalData* globalData = &exec->globalData();
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, s, callback, context));
+    }
+
+    inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
+    {
+        ASSERT(offset <= static_cast<unsigned>(s.size()));
+        ASSERT(length <= static_cast<unsigned>(s.size()));
+        ASSERT(offset + length <= static_cast<unsigned>(s.size()));
+        if (!length)
+            return globalData->smallStrings.emptyString(globalData);
+        if (length == 1) {
+            UChar c = s.data()[offset];
+            if (c <= 0xFF)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UString::Rep::create(s.rep(), offset, length)), JSString::HasOtherOwner));
+    }
+
+    inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
+    {
+        int size = s.size();
+        if (!size)
+            return globalData->smallStrings.emptyString(globalData);
+        if (size == 1) {
+            UChar c = s.data()[0];
+            if (c <= 0xFF)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        return fixupVPtr(globalData, new (globalData) JSString(globalData, s, JSString::HasOtherOwner));

     }
 
     inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
     }
 
     inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }


@@ -178,14 +492,14 @@ namespace JSC {
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
     {
         if (propertyName == exec->propertyNames().length) {
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
     {
         if (propertyName == exec->propertyNames().length) {

-            slot.setValue(jsNumber(exec, m_value.size()));
+            slot.setValue(jsNumber(exec, m_stringLength));

             return true;
         }
 
         bool isStrictUInt32;
         unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
             return true;
         }
 
         bool isStrictUInt32;
         unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);

-        if (isStrictUInt32 && i < static_cast<unsigned>(m_value.size())) {
-            slot.setValue(jsSingleCharacterSubstring(exec, m_value, i));
+        if (isStrictUInt32 && i < m_stringLength) {
+            slot.setValue(jsSingleCharacterSubstring(exec, value(exec), i));

             return true;
         }
 
             return true;
         }
 


@@ -194,19 +508,61 @@ namespace JSC {
         
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {
         
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {

-        if (propertyName < static_cast<unsigned>(m_value.size())) {
-            slot.setValue(jsSingleCharacterSubstring(exec, m_value, propertyName));
+        if (propertyName < m_stringLength) {
+            slot.setValue(jsSingleCharacterSubstring(exec, value(exec), propertyName));

             return true;
         }
 
         return false;
     }
 
             return true;
         }
 
         return false;
     }
 

+    inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
+

     // --- JSValue inlines ----------------------------
 
     // --- JSValue inlines ----------------------------
 

-    inline JSString* JSValuePtr::toThisJSString(ExecState* exec)
+    inline JSString* JSValue::toThisJSString(ExecState* exec)
+    {
+        return isCell() ? asCell()->toThisJSString(exec) : jsString(exec, toString(exec));
+    }
+
+    inline UString JSValue::toString(ExecState* exec) const
+    {
+        if (isString())
+            return static_cast<JSString*>(asCell())->value(exec);
+        if (isInt32())
+            return exec->globalData().numericStrings.add(asInt32());
+        if (isDouble())
+            return exec->globalData().numericStrings.add(asDouble());
+        if (isTrue())
+            return "true";
+        if (isFalse())
+            return "false";
+        if (isNull())
+            return "null";
+        if (isUndefined())
+            return "undefined";
+        ASSERT(isCell());
+        return asCell()->toString(exec);
+    }
+
+    inline UString JSValue::toPrimitiveString(ExecState* exec) const

     {
     {

-        return JSImmediate::isImmediate(asValue()) ? jsString(exec, JSImmediate::toString(asValue())) : asCell()->toThisJSString(exec);
+        if (isString())
+            return static_cast<JSString*>(asCell())->value(exec);
+        if (isInt32())
+            return exec->globalData().numericStrings.add(asInt32());
+        if (isDouble())
+            return exec->globalData().numericStrings.add(asDouble());
+        if (isTrue())
+            return "true";
+        if (isFalse())
+            return "false";
+        if (isNull())
+            return "null";
+        if (isUndefined())
+            return "undefined";
+        ASSERT(isCell());
+        return asCell()->toPrimitive(exec, NoPreference).toString(exec);

     }
 
 } // namespace JSC
     }
 
 } // namespace JSC