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

/*
 * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#ifndef Structure_h
#define Structure_h

#include "ClassInfo.h"
#include "Identifier.h"
#include "JSCell.h"
#include "JSType.h"
#include "JSValue.h"
#include "PropertyMapHashTable.h"
#include "PropertyNameArray.h"
#include "Protect.h"
#include "StructureTransitionTable.h"
#include "JSTypeInfo.h"
#include "UString.h"
#include "Weak.h"
#include <wtf/PassOwnPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>


namespace JSC {

    class LLIntOffsetsExtractor;
    class PropertyNameArray;
    class PropertyNameArrayData;
    class StructureChain;
    class SlotVisitor;
    class JSString;

    class Structure : public JSCell {
    public:
        friend class StructureTransitionTable;

        typedef JSCell Base;

        static Structure* create(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue prototype, const TypeInfo& typeInfo, const ClassInfo* classInfo)
        {
            ASSERT(globalData.structureStructure);
            ASSERT(classInfo);
            Structure* structure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData, globalObject, prototype, typeInfo, classInfo);
            structure->finishCreation(globalData);
            return structure;
        }

    protected:
        void finishCreation(JSGlobalData& globalData)
        {
            Base::finishCreation(globalData);
            ASSERT(m_prototype);
            ASSERT(m_prototype.isObject() || m_prototype.isNull());
        }

        void finishCreation(JSGlobalData& globalData, CreatingEarlyCellTag)
        {
            Base::finishCreation(globalData, this, CreatingEarlyCell);
            ASSERT(m_prototype);
            ASSERT(m_prototype.isNull());
            ASSERT(!globalData.structureStructure);
        }

    public:
        static void dumpStatistics();

        JS_EXPORT_PRIVATE static Structure* addPropertyTransition(JSGlobalData&, Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
        JS_EXPORT_PRIVATE static Structure* addPropertyTransitionToExistingStructure(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
        static Structure* removePropertyTransition(JSGlobalData&, Structure*, const Identifier& propertyName, size_t& offset);
        JS_EXPORT_PRIVATE static Structure* changePrototypeTransition(JSGlobalData&, Structure*, JSValue prototype);
        JS_EXPORT_PRIVATE static Structure* despecifyFunctionTransition(JSGlobalData&, Structure*, const Identifier&);
        static Structure* attributeChangeTransition(JSGlobalData&, Structure*, const Identifier& propertyName, unsigned attributes);
        static Structure* toCacheableDictionaryTransition(JSGlobalData&, Structure*);
        static Structure* toUncacheableDictionaryTransition(JSGlobalData&, Structure*);
        static Structure* sealTransition(JSGlobalData&, Structure*);
        static Structure* freezeTransition(JSGlobalData&, Structure*);
        static Structure* preventExtensionsTransition(JSGlobalData&, Structure*);

        bool isSealed(JSGlobalData&);
        bool isFrozen(JSGlobalData&);
        bool isExtensible() const { return !m_preventExtensions; }
        bool didTransition() const { return m_didTransition; }
        bool shouldGrowPropertyStorage() { return propertyStorageCapacity() == propertyStorageSize(); }
        JS_EXPORT_PRIVATE size_t suggestedNewPropertyStorageSize(); 

        Structure* flattenDictionaryStructure(JSGlobalData&, JSObject*);

        static void destroy(JSCell*);

        // These should be used with caution.  
        JS_EXPORT_PRIVATE size_t addPropertyWithoutTransition(JSGlobalData&, const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
        size_t removePropertyWithoutTransition(JSGlobalData&, const Identifier& propertyName);
        void setPrototypeWithoutTransition(JSGlobalData& globalData, JSValue prototype) { m_prototype.set(globalData, this, prototype); }
        
        bool isDictionary() const { return m_dictionaryKind != NoneDictionaryKind; }
        bool isUncacheableDictionary() const { return m_dictionaryKind == UncachedDictionaryKind; }

        // Type accessors.
        const TypeInfo& typeInfo() const { ASSERT(structure()->classInfo() == &s_info); return m_typeInfo; }
        bool isObject() const { return typeInfo().isObject(); }


        JSGlobalObject* globalObject() const { return m_globalObject.get(); }
        void setGlobalObject(JSGlobalData& globalData, JSGlobalObject* globalObject) { m_globalObject.set(globalData, this, globalObject); }
        
        JSValue storedPrototype() const { return m_prototype.get(); }
        JSValue prototypeForLookup(ExecState*) const;
        StructureChain* prototypeChain(ExecState*) const;
        static void visitChildren(JSCell*, SlotVisitor&);

        Structure* previousID() const { ASSERT(structure()->classInfo() == &s_info); return m_previous.get(); }
        bool transitivelyTransitionedFrom(Structure* structureToFind);

        void growPropertyStorageCapacity();
        unsigned propertyStorageCapacity() const { ASSERT(structure()->classInfo() == &s_info); return m_propertyStorageCapacity; }
        unsigned propertyStorageSize() const { ASSERT(structure()->classInfo() == &s_info); return (m_propertyTable ? m_propertyTable->propertyStorageSize() : static_cast<unsigned>(m_offset + 1)); }
        bool isUsingInlineStorage() const;

        size_t get(JSGlobalData&, const Identifier& propertyName);
        size_t get(JSGlobalData&, const UString& name);
        JS_EXPORT_PRIVATE size_t get(JSGlobalData&, StringImpl* propertyName, unsigned& attributes, JSCell*& specificValue);
        size_t get(JSGlobalData& globalData, const Identifier& propertyName, unsigned& attributes, JSCell*& specificValue)
        {
            ASSERT(!propertyName.isNull());
            ASSERT(structure()->classInfo() == &s_info);
            return get(globalData, propertyName.impl(), attributes, specificValue);
        }

        bool hasGetterSetterProperties() const { return m_hasGetterSetterProperties; }
        bool hasReadOnlyOrGetterSetterPropertiesExcludingProto() const { return m_hasReadOnlyOrGetterSetterPropertiesExcludingProto; }
        void setHasGetterSetterProperties(bool is__proto__)
        {
            m_hasGetterSetterProperties = true;
            if (!is__proto__)
                m_hasReadOnlyOrGetterSetterPropertiesExcludingProto = true;
        }
        void setContainsReadOnlyProperties()
        {
            m_hasReadOnlyOrGetterSetterPropertiesExcludingProto = true;
        }

        bool hasNonEnumerableProperties() const { return m_hasNonEnumerableProperties; }
        
        bool isEmpty() const { return m_propertyTable ? m_propertyTable->isEmpty() : m_offset == noOffset; }

        JS_EXPORT_PRIVATE void despecifyDictionaryFunction(JSGlobalData&, const Identifier& propertyName);
        void disableSpecificFunctionTracking() { m_specificFunctionThrashCount = maxSpecificFunctionThrashCount; }

        void setEnumerationCache(JSGlobalData&, JSPropertyNameIterator* enumerationCache); // Defined in JSPropertyNameIterator.h.
        JSPropertyNameIterator* enumerationCache(); // Defined in JSPropertyNameIterator.h.
        void getPropertyNamesFromStructure(JSGlobalData&, PropertyNameArray&, EnumerationMode);

        JSString* objectToStringValue() { return m_objectToStringValue.get(); }

        void setObjectToStringValue(JSGlobalData& globalData, const JSCell* owner, JSString* value)
        {
            m_objectToStringValue.set(globalData, owner, value);
        }

        bool staticFunctionsReified()
        {
            return m_staticFunctionReified;
        }

        void setStaticFunctionsReified()
        {
            m_staticFunctionReified = true;
        }

        const ClassInfo* classInfo() const { return m_classInfo; }

        static ptrdiff_t prototypeOffset()
        {
            return OBJECT_OFFSETOF(Structure, m_prototype);
        }

        static ptrdiff_t typeInfoFlagsOffset()
        {
            return OBJECT_OFFSETOF(Structure, m_typeInfo) + TypeInfo::flagsOffset();
        }

        static ptrdiff_t typeInfoTypeOffset()
        {
            return OBJECT_OFFSETOF(Structure, m_typeInfo) + TypeInfo::typeOffset();
        }

        static Structure* createStructure(JSGlobalData& globalData)
        {
            ASSERT(!globalData.structureStructure);
            Structure* structure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData);
            structure->finishCreation(globalData, CreatingEarlyCell);
            return structure;
        }
        
        static JS_EXPORTDATA const ClassInfo s_info;

    private:
        friend class LLIntOffsetsExtractor;
        
        JS_EXPORT_PRIVATE Structure(JSGlobalData&, JSGlobalObject*, JSValue prototype, const TypeInfo&, const ClassInfo*);
        Structure(JSGlobalData&);
        Structure(JSGlobalData&, const Structure*);

        static Structure* create(JSGlobalData& globalData, const Structure* structure)
        {
            ASSERT(globalData.structureStructure);
            Structure* newStructure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData, structure);
            newStructure->finishCreation(globalData);
            return newStructure;
        }
        
        typedef enum { 
            NoneDictionaryKind = 0,
            CachedDictionaryKind = 1,
            UncachedDictionaryKind = 2
        } DictionaryKind;
        static Structure* toDictionaryTransition(JSGlobalData&, Structure*, DictionaryKind);

        size_t putSpecificValue(JSGlobalData&, const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
        size_t remove(const Identifier& propertyName);

        void createPropertyMap(unsigned keyCount = 0);
        void checkConsistency();

        bool despecifyFunction(JSGlobalData&, const Identifier&);
        void despecifyAllFunctions(JSGlobalData&);

        PassOwnPtr<PropertyTable> copyPropertyTable(JSGlobalData&, Structure* owner);
        PassOwnPtr<PropertyTable> copyPropertyTableForPinning(JSGlobalData&, Structure* owner);
        JS_EXPORT_PRIVATE void materializePropertyMap(JSGlobalData&);
        void materializePropertyMapIfNecessary(JSGlobalData& globalData)
        {
            ASSERT(structure()->classInfo() == &s_info);
            if (!m_propertyTable && m_previous)
                materializePropertyMap(globalData);
        }
        void materializePropertyMapIfNecessaryForPinning(JSGlobalData& globalData)
        {
            ASSERT(structure()->classInfo() == &s_info);
            if (!m_propertyTable)
                materializePropertyMap(globalData);
        }

        int transitionCount() const
        {
            // Since the number of transitions is always the same as m_offset, we keep the size of Structure down by not storing both.
            return m_offset == noOffset ? 0 : m_offset + 1;
        }

        bool isValid(ExecState*, StructureChain* cachedPrototypeChain) const;
        
        void pin();

        static const int s_maxTransitionLength = 64;

        static const int noOffset = -1;

        static const unsigned maxSpecificFunctionThrashCount = 3;

        TypeInfo m_typeInfo;
        
        WriteBarrier<JSGlobalObject> m_globalObject;
        WriteBarrier<Unknown> m_prototype;
        mutable WriteBarrier<StructureChain> m_cachedPrototypeChain;

        WriteBarrier<Structure> m_previous;
        RefPtr<StringImpl> m_nameInPrevious;
        WriteBarrier<JSCell> m_specificValueInPrevious;

        const ClassInfo* m_classInfo;

        StructureTransitionTable m_transitionTable;

        WriteBarrier<JSPropertyNameIterator> m_enumerationCache;

        OwnPtr<PropertyTable> m_propertyTable;

        uint32_t m_propertyStorageCapacity;

        WriteBarrier<JSString> m_objectToStringValue;

        // m_offset does not account for anonymous slots
        int m_offset;

        unsigned m_dictionaryKind : 2;
        bool m_isPinnedPropertyTable : 1;
        bool m_hasGetterSetterProperties : 1;
        bool m_hasReadOnlyOrGetterSetterPropertiesExcludingProto : 1;
        bool m_hasNonEnumerableProperties : 1;
        unsigned m_attributesInPrevious : 7;
        unsigned m_specificFunctionThrashCount : 2;
        unsigned m_preventExtensions : 1;
        unsigned m_didTransition : 1;
        unsigned m_staticFunctionReified;
    };

    inline size_t Structure::get(JSGlobalData& globalData, const Identifier& propertyName)
    {
        ASSERT(structure()->classInfo() == &s_info);
        materializePropertyMapIfNecessary(globalData);
        if (!m_propertyTable)
            return notFound;

        PropertyMapEntry* entry = m_propertyTable->find(propertyName.impl()).first;
        return entry ? entry->offset : notFound;
    }

    inline size_t Structure::get(JSGlobalData& globalData, const UString& name)
    {
        ASSERT(structure()->classInfo() == &s_info);
        materializePropertyMapIfNecessary(globalData);
        if (!m_propertyTable)
            return notFound;

        PropertyMapEntry* entry = m_propertyTable->findWithString(name.impl()).first;
        return entry ? entry->offset : notFound;
    }
    
    inline bool JSCell::isObject() const
    {
        return m_structure->isObject();
    }

    inline bool JSCell::isString() const
    {
        return m_structure->typeInfo().type() == StringType;
    }

    inline bool JSCell::isGetterSetter() const
    {
        return m_structure->typeInfo().type() == GetterSetterType;
    }

    inline bool JSCell::isAPIValueWrapper() const
    {
        return m_structure->typeInfo().type() == APIValueWrapperType;
    }

    inline void JSCell::setStructure(JSGlobalData& globalData, Structure* structure)
    {
        ASSERT(structure->typeInfo().overridesVisitChildren() == this->structure()->typeInfo().overridesVisitChildren());
        ASSERT(structure->classInfo() == m_structure->classInfo());
        m_structure.set(globalData, this, structure);
    }

    inline const ClassInfo* JSCell::validatedClassInfo() const
    {
#if ENABLE(GC_VALIDATION)
        ASSERT(m_structure.unvalidatedGet()->classInfo() == m_classInfo);
#else
        ASSERT(m_structure->classInfo() == m_classInfo);
#endif
        return m_classInfo;
    }

    ALWAYS_INLINE void MarkStack::internalAppend(JSCell* cell)
    {
        ASSERT(!m_isCheckingForDefaultMarkViolation);
#if ENABLE(GC_VALIDATION)
        validate(cell);
#endif
        m_visitCount++;
        if (Heap::testAndSetMarked(cell) || !cell->structure())
            return;
        
        // Should never attempt to mark something that is zapped.
        ASSERT(!cell->isZapped());
        
        m_stack.append(cell);
    }

    inline StructureTransitionTable::Hash::Key StructureTransitionTable::keyForWeakGCMapFinalizer(void*, Structure* structure)
    {
        // Newer versions of the STL have an std::make_pair function that takes rvalue references.
        // When either of the parameters are bitfields, the C++ compiler will try to bind them as lvalues, which is invalid. To work around this, use unary "+" to make the parameter an rvalue.
        // See https://bugs.webkit.org/show_bug.cgi?id=59261 for more details.
        return Hash::Key(structure->m_nameInPrevious.get(), +structure->m_attributesInPrevious);
    }

    inline bool Structure::transitivelyTransitionedFrom(Structure* structureToFind)
    {
        for (Structure* current = this; current; current = current->previousID()) {
            if (current == structureToFind)
                return true;
        }
        return false;
    }

    inline JSCell::JSCell(JSGlobalData& globalData, Structure* structure)
        : m_classInfo(structure->classInfo())
        , m_structure(globalData, this, structure)
    {
    }

    inline void JSCell::finishCreation(JSGlobalData& globalData, Structure* structure, CreatingEarlyCellTag)
    {
#if ENABLE(GC_VALIDATION)
        ASSERT(globalData.isInitializingObject());
        globalData.setInitializingObjectClass(0);
        if (structure)
#endif
            m_structure.setEarlyValue(globalData, this, structure);
        m_classInfo = structure->classInfo();
        // Very first set of allocations won't have a real structure.
        ASSERT(m_structure || !globalData.structureStructure);
    }

} // namespace JSC

#endif // Structure_h
Commit	Line	Data
9dae56ea	1	/*
f9bf01c6	2	* Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
9dae56ea A	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
	14	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	15	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	16	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
	17	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	18	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	19	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	20	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	21	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	23	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
	26	#ifndef Structure_h
	27	#define Structure_h
	28
6fe7ccc8	29	#include "ClassInfo.h"
9dae56ea	30	#include "Identifier.h"
14957cd0	31	#include "JSCell.h"
9dae56ea A	32	#include "JSType.h"
	33	#include "JSValue.h"
	34	#include "PropertyMapHashTable.h"
f9bf01c6 A	35	#include "PropertyNameArray.h"
f9bf01c6 A	36	#include "Protect.h"
9dae56ea	37	#include "StructureTransitionTable.h"
f9bf01c6	38	#include "JSTypeInfo.h"
9dae56ea	39	#include "UString.h"
14957cd0 A	40	#include "Weak.h"
14957cd0 A	41	#include <wtf/PassOwnPtr.h>
9dae56ea A	42	#include <wtf/PassRefPtr.h>
	43	#include <wtf/RefCounted.h>
	44
9dae56ea A	45
	46	namespace JSC {
	47
6fe7ccc8	48	class LLIntOffsetsExtractor;
9dae56ea A	49	class PropertyNameArray;
9dae56ea A	50	class PropertyNameArrayData;
14957cd0	51	class StructureChain;
6fe7ccc8 A	52	class SlotVisitor;
6fe7ccc8 A	53	class JSString;
f9bf01c6	54
14957cd0	55	class Structure : public JSCell {
9dae56ea	56	public:
f9bf01c6	57	friend class StructureTransitionTable;
6fe7ccc8 A	58
	59	typedef JSCell Base;
	60
	61	static Structure* create(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue prototype, const TypeInfo& typeInfo, const ClassInfo* classInfo)
9dae56ea	62	{
14957cd0 A	63	ASSERT(globalData.structureStructure);
14957cd0 A	64	ASSERT(classInfo);
6fe7ccc8 A	65	Structure* structure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData, globalObject, prototype, typeInfo, classInfo);
	66	structure->finishCreation(globalData);
	67	return structure;
9dae56ea A	68	}
9dae56ea A	69
6fe7ccc8 A	70	protected:
	71	void finishCreation(JSGlobalData& globalData)
	72	{
	73	Base::finishCreation(globalData);
	74	ASSERT(m_prototype);
	75	ASSERT(m_prototype.isObject() \|\| m_prototype.isNull());
	76	}
	77
	78	void finishCreation(JSGlobalData& globalData, CreatingEarlyCellTag)
	79	{
	80	Base::finishCreation(globalData, this, CreatingEarlyCell);
	81	ASSERT(m_prototype);
	82	ASSERT(m_prototype.isNull());
	83	ASSERT(!globalData.structureStructure);
	84	}
	85
	86	public:
9dae56ea A	87	static void dumpStatistics();
9dae56ea A	88
6fe7ccc8 A	89	JS_EXPORT_PRIVATE static Structure* addPropertyTransition(JSGlobalData&, Structure, const Identifier& propertyName, unsigned attributes, JSCell specificValue, size_t& offset);
6fe7ccc8 A	90	JS_EXPORT_PRIVATE static Structure* addPropertyTransitionToExistingStructure(Structure, const Identifier& propertyName, unsigned attributes, JSCell specificValue, size_t& offset);
14957cd0	91	static Structure* removePropertyTransition(JSGlobalData&, Structure*, const Identifier& propertyName, size_t& offset);
6fe7ccc8 A	92	JS_EXPORT_PRIVATE static Structure* changePrototypeTransition(JSGlobalData&, Structure*, JSValue prototype);
	93	JS_EXPORT_PRIVATE static Structure* despecifyFunctionTransition(JSGlobalData&, Structure*, const Identifier&);
	94	static Structure* attributeChangeTransition(JSGlobalData&, Structure*, const Identifier& propertyName, unsigned attributes);
14957cd0 A	95	static Structure* toCacheableDictionaryTransition(JSGlobalData&, Structure*);
	96	static Structure* toUncacheableDictionaryTransition(JSGlobalData&, Structure*);
	97	static Structure* sealTransition(JSGlobalData&, Structure*);
	98	static Structure* freezeTransition(JSGlobalData&, Structure*);
	99	static Structure* preventExtensionsTransition(JSGlobalData&, Structure*);
	100
	101	bool isSealed(JSGlobalData&);
	102	bool isFrozen(JSGlobalData&);
	103	bool isExtensible() const { return !m_preventExtensions; }
	104	bool didTransition() const { return m_didTransition; }
6fe7ccc8 A	105	bool shouldGrowPropertyStorage() { return propertyStorageCapacity() == propertyStorageSize(); }
6fe7ccc8 A	106	JS_EXPORT_PRIVATE size_t suggestedNewPropertyStorageSize();
14957cd0 A	107
14957cd0 A	108	Structure* flattenDictionaryStructure(JSGlobalData&, JSObject*);
9dae56ea	109
6fe7ccc8	110	static void destroy(JSCell*);
9dae56ea	111
9dae56ea	112	// These should be used with caution.
6fe7ccc8	113	JS_EXPORT_PRIVATE size_t addPropertyWithoutTransition(JSGlobalData&, const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
14957cd0 A	114	size_t removePropertyWithoutTransition(JSGlobalData&, const Identifier& propertyName);
14957cd0 A	115	void setPrototypeWithoutTransition(JSGlobalData& globalData, JSValue prototype) { m_prototype.set(globalData, this, prototype); }
ba379fdc A	116
	117	bool isDictionary() const { return m_dictionaryKind != NoneDictionaryKind; }
	118	bool isUncacheableDictionary() const { return m_dictionaryKind == UncachedDictionaryKind; }
9dae56ea	119
6fe7ccc8	120	// Type accessors.
14957cd0	121	const TypeInfo& typeInfo() const { ASSERT(structure()->classInfo() == &s_info); return m_typeInfo; }
6fe7ccc8	122	bool isObject() const { return typeInfo().isObject(); }
9dae56ea	123
6fe7ccc8 A	124
	125	JSGlobalObject* globalObject() const { return m_globalObject.get(); }
	126	void setGlobalObject(JSGlobalData& globalData, JSGlobalObject* globalObject) { m_globalObject.set(globalData, this, globalObject); }
	127
14957cd0	128	JSValue storedPrototype() const { return m_prototype.get(); }
ba379fdc	129	JSValue prototypeForLookup(ExecState*) const;
9dae56ea	130	StructureChain* prototypeChain(ExecState*) const;
6fe7ccc8	131	static void visitChildren(JSCell*, SlotVisitor&);
9dae56ea	132
14957cd0	133	Structure* previousID() const { ASSERT(structure()->classInfo() == &s_info); return m_previous.get(); }
6fe7ccc8	134	bool transitivelyTransitionedFrom(Structure* structureToFind);
9dae56ea A	135
9dae56ea A	136	void growPropertyStorageCapacity();
14957cd0	137	unsigned propertyStorageCapacity() const { ASSERT(structure()->classInfo() == &s_info); return m_propertyStorageCapacity; }
6fe7ccc8	138	unsigned propertyStorageSize() const { ASSERT(structure()->classInfo() == &s_info); return (m_propertyTable ? m_propertyTable->propertyStorageSize() : static_cast<unsigned>(m_offset + 1)); }
ba379fdc	139	bool isUsingInlineStorage() const;
9dae56ea	140
14957cd0	141	size_t get(JSGlobalData&, const Identifier& propertyName);
6fe7ccc8 A	142	size_t get(JSGlobalData&, const UString& name);
6fe7ccc8 A	143	JS_EXPORT_PRIVATE size_t get(JSGlobalData&, StringImpl* propertyName, unsigned& attributes, JSCell*& specificValue);
14957cd0	144	size_t get(JSGlobalData& globalData, const Identifier& propertyName, unsigned& attributes, JSCell*& specificValue)
ba379fdc A	145	{
ba379fdc A	146	ASSERT(!propertyName.isNull());
14957cd0 A	147	ASSERT(structure()->classInfo() == &s_info);
14957cd0 A	148	return get(globalData, propertyName.impl(), attributes, specificValue);
ba379fdc A	149	}
ba379fdc A	150
9dae56ea	151	bool hasGetterSetterProperties() const { return m_hasGetterSetterProperties; }
6fe7ccc8 A	152	bool hasReadOnlyOrGetterSetterPropertiesExcludingProto() const { return m_hasReadOnlyOrGetterSetterPropertiesExcludingProto; }
	153	void setHasGetterSetterProperties(bool is__proto__)
	154	{
	155	m_hasGetterSetterProperties = true;
	156	if (!is__proto__)
	157	m_hasReadOnlyOrGetterSetterPropertiesExcludingProto = true;
	158	}
	159	void setContainsReadOnlyProperties()
	160	{
	161	m_hasReadOnlyOrGetterSetterPropertiesExcludingProto = true;
	162	}
9dae56ea	163
f9bf01c6	164	bool hasNonEnumerableProperties() const { return m_hasNonEnumerableProperties; }
f9bf01c6	165
14957cd0	166	bool isEmpty() const { return m_propertyTable ? m_propertyTable->isEmpty() : m_offset == noOffset; }
9dae56ea	167
6fe7ccc8	168	JS_EXPORT_PRIVATE void despecifyDictionaryFunction(JSGlobalData&, const Identifier& propertyName);
f9bf01c6	169	void disableSpecificFunctionTracking() { m_specificFunctionThrashCount = maxSpecificFunctionThrashCount; }
9dae56ea	170
14957cd0	171	void setEnumerationCache(JSGlobalData&, JSPropertyNameIterator* enumerationCache); // Defined in JSPropertyNameIterator.h.
f9bf01c6	172	JSPropertyNameIterator* enumerationCache(); // Defined in JSPropertyNameIterator.h.
6fe7ccc8 A	173	void getPropertyNamesFromStructure(JSGlobalData&, PropertyNameArray&, EnumerationMode);
	174
	175	JSString* objectToStringValue() { return m_objectToStringValue.get(); }
	176
	177	void setObjectToStringValue(JSGlobalData& globalData, const JSCell* owner, JSString* value)
	178	{
	179	m_objectToStringValue.set(globalData, owner, value);
	180	}
	181
	182	bool staticFunctionsReified()
	183	{
	184	return m_staticFunctionReified;
	185	}
	186
	187	void setStaticFunctionsReified()
	188	{
	189	m_staticFunctionReified = true;
	190	}
14957cd0 A	191
	192	const ClassInfo* classInfo() const { return m_classInfo; }
	193
	194	static ptrdiff_t prototypeOffset()
	195	{
	196	return OBJECT_OFFSETOF(Structure, m_prototype);
	197	}
	198
	199	static ptrdiff_t typeInfoFlagsOffset()
	200	{
	201	return OBJECT_OFFSETOF(Structure, m_typeInfo) + TypeInfo::flagsOffset();
	202	}
	203
	204	static ptrdiff_t typeInfoTypeOffset()
	205	{
	206	return OBJECT_OFFSETOF(Structure, m_typeInfo) + TypeInfo::typeOffset();
	207	}
	208
	209	static Structure* createStructure(JSGlobalData& globalData)
	210	{
	211	ASSERT(!globalData.structureStructure);
6fe7ccc8 A	212	Structure* structure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData);
	213	structure->finishCreation(globalData, CreatingEarlyCell);
	214	return structure;
14957cd0	215	}
f9bf01c6	216
14957cd0 A	217	static JS_EXPORTDATA const ClassInfo s_info;
14957cd0 A	218
ba379fdc	219	private:
6fe7ccc8 A	220	friend class LLIntOffsetsExtractor;
	221
	222	JS_EXPORT_PRIVATE Structure(JSGlobalData&, JSGlobalObject, JSValue prototype, const TypeInfo&, const ClassInfo);
14957cd0 A	223	Structure(JSGlobalData&);
14957cd0 A	224	Structure(JSGlobalData&, const Structure*);
f9bf01c6	225
14957cd0 A	226	static Structure* create(JSGlobalData& globalData, const Structure* structure)
	227	{
	228	ASSERT(globalData.structureStructure);
6fe7ccc8 A	229	Structure* newStructure = new (NotNull, allocateCell<Structure>(globalData.heap)) Structure(globalData, structure);
	230	newStructure->finishCreation(globalData);
	231	return newStructure;
14957cd0	232	}
ba379fdc A	233
	234	typedef enum {
	235	NoneDictionaryKind = 0,
	236	CachedDictionaryKind = 1,
	237	UncachedDictionaryKind = 2
	238	} DictionaryKind;
14957cd0	239	static Structure* toDictionaryTransition(JSGlobalData&, Structure*, DictionaryKind);
ba379fdc	240
14957cd0	241	size_t putSpecificValue(JSGlobalData&, const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
9dae56ea	242	size_t remove(const Identifier& propertyName);
9dae56ea	243
14957cd0	244	void createPropertyMap(unsigned keyCount = 0);
9dae56ea A	245	void checkConsistency();
9dae56ea A	246
14957cd0 A	247	bool despecifyFunction(JSGlobalData&, const Identifier&);
14957cd0 A	248	void despecifyAllFunctions(JSGlobalData&);
ba379fdc	249
14957cd0	250	PassOwnPtr<PropertyTable> copyPropertyTable(JSGlobalData&, Structure* owner);
6fe7ccc8 A	251	PassOwnPtr<PropertyTable> copyPropertyTableForPinning(JSGlobalData&, Structure* owner);
6fe7ccc8 A	252	JS_EXPORT_PRIVATE void materializePropertyMap(JSGlobalData&);
14957cd0	253	void materializePropertyMapIfNecessary(JSGlobalData& globalData)
9dae56ea	254	{
14957cd0 A	255	ASSERT(structure()->classInfo() == &s_info);
	256	if (!m_propertyTable && m_previous)
	257	materializePropertyMap(globalData);
9dae56ea	258	}
6fe7ccc8 A	259	void materializePropertyMapIfNecessaryForPinning(JSGlobalData& globalData)
	260	{
	261	ASSERT(structure()->classInfo() == &s_info);
	262	if (!m_propertyTable)
	263	materializePropertyMap(globalData);
	264	}
9dae56ea	265
6fe7ccc8	266	int transitionCount() const
9dae56ea A	267	{
	268	// Since the number of transitions is always the same as m_offset, we keep the size of Structure down by not storing both.
	269	return m_offset == noOffset ? 0 : m_offset + 1;
	270	}
4e4e5a6f	271
9dae56ea	272	bool isValid(ExecState, StructureChain cachedPrototypeChain) const;
6fe7ccc8 A	273
6fe7ccc8 A	274	void pin();
9dae56ea	275
6fe7ccc8	276	static const int s_maxTransitionLength = 64;
9dae56ea	277
6fe7ccc8	278	static const int noOffset = -1;
9dae56ea	279
f9bf01c6 A	280	static const unsigned maxSpecificFunctionThrashCount = 3;
f9bf01c6 A	281
9dae56ea	282	TypeInfo m_typeInfo;
6fe7ccc8 A	283
6fe7ccc8 A	284	WriteBarrier<JSGlobalObject> m_globalObject;
14957cd0 A	285	WriteBarrier<Unknown> m_prototype;
14957cd0 A	286	mutable WriteBarrier<StructureChain> m_cachedPrototypeChain;
9dae56ea	287
14957cd0 A	288	WriteBarrier<Structure> m_previous;
	289	RefPtr<StringImpl> m_nameInPrevious;
	290	WriteBarrier<JSCell> m_specificValueInPrevious;
9dae56ea	291
14957cd0	292	const ClassInfo* m_classInfo;
9dae56ea	293
14957cd0	294	StructureTransitionTable m_transitionTable;
9dae56ea	295
14957cd0 A	296	WriteBarrier<JSPropertyNameIterator> m_enumerationCache;
	297
	298	OwnPtr<PropertyTable> m_propertyTable;
9dae56ea	299
f9bf01c6 A	300	uint32_t m_propertyStorageCapacity;
f9bf01c6 A	301
6fe7ccc8 A	302	WriteBarrier<JSString> m_objectToStringValue;
6fe7ccc8 A	303
f9bf01c6	304	// m_offset does not account for anonymous slots
6fe7ccc8	305	int m_offset;
9dae56ea	306
ba379fdc	307	unsigned m_dictionaryKind : 2;
9dae56ea A	308	bool m_isPinnedPropertyTable : 1;
9dae56ea A	309	bool m_hasGetterSetterProperties : 1;
6fe7ccc8	310	bool m_hasReadOnlyOrGetterSetterPropertiesExcludingProto : 1;
f9bf01c6	311	bool m_hasNonEnumerableProperties : 1;
ba379fdc	312	unsigned m_attributesInPrevious : 7;
f9bf01c6	313	unsigned m_specificFunctionThrashCount : 2;
14957cd0 A	314	unsigned m_preventExtensions : 1;
14957cd0 A	315	unsigned m_didTransition : 1;
6fe7ccc8	316	unsigned m_staticFunctionReified;
9dae56ea A	317	};
9dae56ea A	318
14957cd0	319	inline size_t Structure::get(JSGlobalData& globalData, const Identifier& propertyName)
9dae56ea	320	{
14957cd0 A	321	ASSERT(structure()->classInfo() == &s_info);
14957cd0 A	322	materializePropertyMapIfNecessary(globalData);
9dae56ea	323	if (!m_propertyTable)
14957cd0	324	return notFound;
9dae56ea	325
14957cd0	326	PropertyMapEntry* entry = m_propertyTable->find(propertyName.impl()).first;
14957cd0 A	327	return entry ? entry->offset : notFound;
14957cd0 A	328	}
9dae56ea	329
6fe7ccc8 A	330	inline size_t Structure::get(JSGlobalData& globalData, const UString& name)
	331	{
	332	ASSERT(structure()->classInfo() == &s_info);
	333	materializePropertyMapIfNecessary(globalData);
	334	if (!m_propertyTable)
	335	return notFound;
	336
	337	PropertyMapEntry* entry = m_propertyTable->findWithString(name.impl()).first;
	338	return entry ? entry->offset : notFound;
	339	}
	340
14957cd0 A	341	inline bool JSCell::isObject() const
14957cd0 A	342	{
6fe7ccc8	343	return m_structure->isObject();
14957cd0	344	}
9dae56ea	345
14957cd0 A	346	inline bool JSCell::isString() const
	347	{
	348	return m_structure->typeInfo().type() == StringType;
	349	}
9dae56ea	350
6fe7ccc8	351	inline bool JSCell::isGetterSetter() const
14957cd0	352	{
6fe7ccc8	353	return m_structure->typeInfo().type() == GetterSetterType;
14957cd0	354	}
9dae56ea	355
6fe7ccc8	356	inline bool JSCell::isAPIValueWrapper() const
14957cd0	357	{
6fe7ccc8	358	return m_structure->typeInfo().type() == APIValueWrapperType;
14957cd0	359	}
9dae56ea	360
6fe7ccc8	361	inline void JSCell::setStructure(JSGlobalData& globalData, Structure* structure)
14957cd0	362	{
6fe7ccc8 A	363	ASSERT(structure->typeInfo().overridesVisitChildren() == this->structure()->typeInfo().overridesVisitChildren());
	364	ASSERT(structure->classInfo() == m_structure->classInfo());
	365	m_structure.set(globalData, this, structure);
	366	}
	367
	368	inline const ClassInfo* JSCell::validatedClassInfo() const
	369	{
	370	#if ENABLE(GC_VALIDATION)
	371	ASSERT(m_structure.unvalidatedGet()->classInfo() == m_classInfo);
	372	#else
	373	ASSERT(m_structure->classInfo() == m_classInfo);
	374	#endif
	375	return m_classInfo;
14957cd0	376	}
9dae56ea	377
14957cd0 A	378	ALWAYS_INLINE void MarkStack::internalAppend(JSCell* cell)
	379	{
	380	ASSERT(!m_isCheckingForDefaultMarkViolation);
6fe7ccc8 A	381	#if ENABLE(GC_VALIDATION)
	382	validate(cell);
	383	#endif
	384	m_visitCount++;
	385	if (Heap::testAndSetMarked(cell) \|\| !cell->structure())
14957cd0	386	return;
6fe7ccc8 A	387
	388	// Should never attempt to mark something that is zapped.
	389	ASSERT(!cell->isZapped());
	390
	391	m_stack.append(cell);
14957cd0	392	}
9dae56ea	393
14957cd0 A	394	inline StructureTransitionTable::Hash::Key StructureTransitionTable::keyForWeakGCMapFinalizer(void, Structure structure)
	395	{
	396	// Newer versions of the STL have an std::make_pair function that takes rvalue references.
	397	// When either of the parameters are bitfields, the C++ compiler will try to bind them as lvalues, which is invalid. To work around this, use unary "+" to make the parameter an rvalue.
	398	// See https://bugs.webkit.org/show_bug.cgi?id=59261 for more details.
	399	return Hash::Key(structure->m_nameInPrevious.get(), +structure->m_attributesInPrevious);
9dae56ea A	400	}
9dae56ea A	401
6fe7ccc8 A	402	inline bool Structure::transitivelyTransitionedFrom(Structure* structureToFind)
	403	{
	404	for (Structure* current = this; current; current = current->previousID()) {
	405	if (current == structureToFind)
	406	return true;
	407	}
	408	return false;
	409	}
	410
	411	inline JSCell::JSCell(JSGlobalData& globalData, Structure* structure)
	412	: m_classInfo(structure->classInfo())
	413	, m_structure(globalData, this, structure)
	414	{
	415	}
	416
	417	inline void JSCell::finishCreation(JSGlobalData& globalData, Structure* structure, CreatingEarlyCellTag)
	418	{
	419	#if ENABLE(GC_VALIDATION)
	420	ASSERT(globalData.isInitializingObject());
	421	globalData.setInitializingObjectClass(0);
	422	if (structure)
	423	#endif
	424	m_structure.setEarlyValue(globalData, this, structure);
	425	m_classInfo = structure->classInfo();
	426	// Very first set of allocations won't have a real structure.
	427	ASSERT(m_structure \|\| !globalData.structureStructure);
	428	}
	429
9dae56ea A	430	} // namespace JSC
	431
	432	#endif // Structure_h