Source/JavaScriptCore/runtime/Lookup.h - WebKit - Git at Google

 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #ifndef Lookup_h
 #define Lookup_h

 #include "BatchedTransitionOptimizer.h"
 #include "CallFrame.h"
 #include "CustomGetterSetter.h"
 #include "Identifier.h"
 #include "IdentifierInlines.h"
 #include "Intrinsic.h"
 #include "JSGlobalObject.h"
 #include "PropertySlot.h"
 #include "PutPropertySlot.h"
 #include <wtf/Assertions.h>

 namespace JSC {

 struct CompactHashIndex {
     const int16_t value;
     const int16_t next;
 };

 // FIXME: There is no reason this get function can't be simpler.
 // ie. typedef JSValue (*GetFunction)(ExecState*, JSObject* baseObject)
 typedef PropertySlot::GetValueFunc GetFunction;
 typedef PutPropertySlot::PutValueFunc PutFunction;
 typedef FunctionExecutable* (*BuiltinGenerator)(VM&);

 // Hash table generated by the create_hash_table script.
 struct HashTableValue {
     const char* m_key; // property name
     unsigned m_attributes; // JSObject attributes
     Intrinsic m_intrinsic;
     intptr_t m_value1;
     intptr_t m_value2;

     unsigned attributes() const { return m_attributes; }

     Intrinsic intrinsic() const { ASSERT(m_attributes & Function); return m_intrinsic; }
     BuiltinGenerator builtinGenerator() const { ASSERT(m_attributes & Builtin); return reinterpret_cast<BuiltinGenerator>(m_value1); }
     NativeFunction function() const { ASSERT(m_attributes & Function); return reinterpret_cast<NativeFunction>(m_value1); }
     unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_value2); }

     GetFunction propertyGetter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<GetFunction>(m_value1); }
     PutFunction propertyPutter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<PutFunction>(m_value2); }

     intptr_t constantInteger() const { ASSERT(m_attributes & ConstantInteger); return m_value1; }

     intptr_t lexerValue() const { ASSERT(!m_attributes); return m_value1; }
 };

 struct HashTable {
     mutable int numberOfValues;
     int indexMask;
     bool hasSetterOrReadonlyProperties;

     const HashTableValue* values; // Fixed values generated by script.
     mutable const char** keys; // Table allocated at runtime.
     const CompactHashIndex* index;

     ALWAYS_INLINE HashTable copy() const
     {
         // Don't copy dynamic table since it's thread specific.
         HashTable result = { numberOfValues, indexMask, hasSetterOrReadonlyProperties, values, 0, index };
         return result;
     }

     ALWAYS_INLINE void initializeIfNeeded() const
     {
         if (!keys)
             createTable();
     }

     JS_EXPORT_PRIVATE void deleteTable() const;

     // Find an entry in the table, and return the entry.
     ALWAYS_INLINE const HashTableValue* entry(PropertyName propertyName) const
     {
         initializeIfNeeded();

         StringImpl* impl = propertyName.uid();
         if (!impl)
             return 0;

         ASSERT(keys);

         int indexEntry = impl->existingHash() & indexMask;
         int valueIndex = index[indexEntry].value;
         if (valueIndex == -1)
             return 0;

         while (true) {
             if (WTF::equal(impl, keys[valueIndex]))
                 return &values[valueIndex];

             indexEntry = index[indexEntry].next;
             if (indexEntry == -1)
                 return nullptr;
             valueIndex = index[indexEntry].value;
             ASSERT(valueIndex != -1);
         };
     }

     class ConstIterator {
     public:
         ConstIterator(const HashTable* table, int position)
             : m_table(table)
             , m_position(position)
         {
             skipInvalidKeys();
         }

         const HashTableValue* value()
         {
             return &m_table->values[m_position];
         }

         const char* key()
         {
             return m_table->keys[m_position];
         }

         const HashTableValue* operator->()
         {
             return value();
         }

         bool operator!=(const ConstIterator& other)
         {
             ASSERT(m_table == other.m_table);
             return m_position != other.m_position;
         }

         ConstIterator& operator++()
         {
             ASSERT(m_position < m_table->numberOfValues);
             ++m_position;
             skipInvalidKeys();
             return *this;
         }

     private:
         void skipInvalidKeys()
         {
             ASSERT(m_position <= m_table->numberOfValues);
             while (m_position < m_table->numberOfValues && !m_table->keys[m_position])
                 ++m_position;
             ASSERT(m_position <= m_table->numberOfValues);
         }

         const HashTable* m_table;
         int m_position;
     };

     ConstIterator begin() const
     {
         initializeIfNeeded();
         return ConstIterator(this, 0);
     }
     ConstIterator end() const
     {
         initializeIfNeeded();
         return ConstIterator(this, numberOfValues);
     }

 private:
     // Convert the hash table keys to identifiers.
     JS_EXPORT_PRIVATE void createTable() const;
 };

 JS_EXPORT_PRIVATE bool setUpStaticFunctionSlot(ExecState*, const HashTableValue*, JSObject* thisObject, PropertyName, PropertySlot&);

 /**
  * This method does it all (looking in the hashtable, checking for function
  * overrides, creating the function or retrieving from cache, calling
  * getValueProperty in case of a non-function property, forwarding to parent if
  * unknown property).
  */
 template <class ThisImp, class ParentImp>
 inline bool getStaticPropertySlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
 {
     const HashTableValue* entry = table.entry(propertyName);

     if (!entry) // not found, forward to parent
         return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

     if (entry->attributes() & BuiltinOrFunction)
         return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);

     if (entry->attributes() & ConstantInteger) {
         slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger()));
         return true;
     }

     slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
     return true;
 }

 /**
  * Simplified version of getStaticPropertySlot in case there are only functions.
  * Using this instead of getStaticPropertySlot allows 'this' to avoid implementing
  * a dummy getValueProperty.
  */
 template <class ParentImp>
 inline bool getStaticFunctionSlot(ExecState* exec, const HashTable& table, JSObject* thisObj, PropertyName propertyName, PropertySlot& slot)
 {
     if (ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot))
         return true;

     const HashTableValue* entry = table.entry(propertyName);
     if (!entry)
         return false;

     return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);
 }

 /**
  * Simplified version of getStaticPropertySlot in case there are no functions, only "values".
  * Using this instead of getStaticPropertySlot removes the need for a FuncImp class.
  */
 template <class ThisImp, class ParentImp>
 inline bool getStaticValueSlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
 {
     const HashTableValue* entry = table.entry(propertyName);

     if (!entry) // not found, forward to parent
         return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

     ASSERT(!(entry->attributes() & BuiltinOrFunction));

     if (entry->attributes() & ConstantInteger) {
         slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger()));
         return true;
     }

     slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
     return true;
 }

 inline void putEntry(ExecState* exec, const HashTableValue* entry, JSObject* base, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 {
     // If this is a function put it as an override property.
     if (entry->attributes() & BuiltinOrFunction) {
         if (JSObject* thisObject = jsDynamicCast<JSObject*>(slot.thisValue()))
             thisObject->putDirect(exec->vm(), propertyName, value);
     } else if (!(entry->attributes() & ReadOnly)) {
         entry->propertyPutter()(exec, base, JSValue::encode(slot.thisValue()), JSValue::encode(value));
         slot.setCustomProperty(base, entry->propertyPutter());
     } else if (slot.isStrictMode())
         throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
 }

 /**
  * This one is for "put".
  * It looks up a hash entry for the property to be set.  If an entry
  * is found it sets the value and returns true, else it returns false.
  */
 inline bool lookupPut(ExecState* exec, PropertyName propertyName, JSObject* base, JSValue value, const HashTable& table, PutPropertySlot& slot)
 {
     const HashTableValue* entry = table.entry(propertyName);

     if (!entry)
         return false;

     putEntry(exec, entry, base, propertyName, value, slot);
     return true;
 }

 template<unsigned numberOfValues>
 inline void reifyStaticProperties(VM& vm, const HashTableValue (&values)[numberOfValues], JSObject& thisObj)
 {
     BatchedTransitionOptimizer transitionOptimizer(vm, &thisObj);
     for (auto& value : values) {
         if (!value.m_key)
             continue;

         Identifier propertyName(&vm, reinterpret_cast<const LChar*>(value.m_key), strlen(value.m_key));
         if (value.attributes() & Builtin) {
             thisObj.putDirectBuiltinFunction(vm, thisObj.globalObject(), propertyName, value.builtinGenerator()(vm), value.attributes());
             continue;
         }

         if (value.attributes() & Function) {
             thisObj.putDirectNativeFunction(vm, thisObj.globalObject(), propertyName, value.functionLength(),
                 value.function(), value.intrinsic(), value.attributes());
             continue;
         }

         if (value.attributes() & ConstantInteger) {
             thisObj.putDirect(vm, propertyName, jsNumber(value.constantInteger()), value.attributes());
             continue;
         }

         if (value.attributes() & Accessor) {
             RELEASE_ASSERT_NOT_REACHED();
             continue;
         }

         CustomGetterSetter* customGetterSetter = CustomGetterSetter::create(vm, value.propertyGetter(), value.propertyPutter());
         thisObj.putDirectCustomAccessor(vm, propertyName, customGetterSetter, value.attributes());
     }
 }

 } // namespace JSC

 #endif // Lookup_h
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#ifndef Lookup_h
	#define Lookup_h

	#include "BatchedTransitionOptimizer.h"
	#include "CallFrame.h"
	#include "CustomGetterSetter.h"
	#include "Identifier.h"
	#include "IdentifierInlines.h"
	#include "Intrinsic.h"
	#include "JSGlobalObject.h"
	#include "PropertySlot.h"
	#include "PutPropertySlot.h"
	#include <wtf/Assertions.h>

	namespace JSC {

	struct CompactHashIndex {
	const int16_t value;
	const int16_t next;
	};

	// FIXME: There is no reason this get function can't be simpler.
	// ie. typedef JSValue (GetFunction)(ExecState, JSObject* baseObject)
	typedef PropertySlot::GetValueFunc GetFunction;
	typedef PutPropertySlot::PutValueFunc PutFunction;
	typedef FunctionExecutable* (*BuiltinGenerator)(VM&);

	// Hash table generated by the create_hash_table script.
	struct HashTableValue {
	const char* m_key; // property name
	unsigned m_attributes; // JSObject attributes
	Intrinsic m_intrinsic;
	intptr_t m_value1;
	intptr_t m_value2;

	unsigned attributes() const { return m_attributes; }

	Intrinsic intrinsic() const { ASSERT(m_attributes & Function); return m_intrinsic; }
	BuiltinGenerator builtinGenerator() const { ASSERT(m_attributes & Builtin); return reinterpret_cast<BuiltinGenerator>(m_value1); }
	NativeFunction function() const { ASSERT(m_attributes & Function); return reinterpret_cast<NativeFunction>(m_value1); }
	unsigned char functionLength() const { ASSERT(m_attributes & Function); return static_cast<unsigned char>(m_value2); }

	GetFunction propertyGetter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<GetFunction>(m_value1); }
	PutFunction propertyPutter() const { ASSERT(!(m_attributes & BuiltinOrFunctionOrConstant)); return reinterpret_cast<PutFunction>(m_value2); }

	intptr_t constantInteger() const { ASSERT(m_attributes & ConstantInteger); return m_value1; }

	intptr_t lexerValue() const { ASSERT(!m_attributes); return m_value1; }
	};

	struct HashTable {
	mutable int numberOfValues;
	int indexMask;
	bool hasSetterOrReadonlyProperties;

	const HashTableValue* values; // Fixed values generated by script.
	mutable const char** keys; // Table allocated at runtime.
	const CompactHashIndex* index;

	ALWAYS_INLINE HashTable copy() const
	{
	// Don't copy dynamic table since it's thread specific.
	HashTable result = { numberOfValues, indexMask, hasSetterOrReadonlyProperties, values, 0, index };
	return result;
	}

	ALWAYS_INLINE void initializeIfNeeded() const
	{
	if (!keys)
	createTable();
	}

	JS_EXPORT_PRIVATE void deleteTable() const;

	// Find an entry in the table, and return the entry.
	ALWAYS_INLINE const HashTableValue* entry(PropertyName propertyName) const
	{
	initializeIfNeeded();

	StringImpl* impl = propertyName.uid();
	if (!impl)
	return 0;

	ASSERT(keys);

	int indexEntry = impl->existingHash() & indexMask;
	int valueIndex = index[indexEntry].value;
	if (valueIndex == -1)
	return 0;

	while (true) {
	if (WTF::equal(impl, keys[valueIndex]))
	return &values[valueIndex];

	indexEntry = index[indexEntry].next;
	if (indexEntry == -1)
	return nullptr;
	valueIndex = index[indexEntry].value;
	ASSERT(valueIndex != -1);
	};
	}

	class ConstIterator {
	public:
	ConstIterator(const HashTable* table, int position)
	: m_table(table)
	, m_position(position)
	{
	skipInvalidKeys();
	}

	const HashTableValue* value()
	{
	return &m_table->values[m_position];
	}

	const char* key()
	{
	return m_table->keys[m_position];
	}

	const HashTableValue* operator->()
	{
	return value();
	}

	bool operator!=(const ConstIterator& other)
	{
	ASSERT(m_table == other.m_table);
	return m_position != other.m_position;
	}

	ConstIterator& operator++()
	{
	ASSERT(m_position < m_table->numberOfValues);
	++m_position;
	skipInvalidKeys();
	return *this;
	}

	private:
	void skipInvalidKeys()
	{
	ASSERT(m_position <= m_table->numberOfValues);
	while (m_position < m_table->numberOfValues && !m_table->keys[m_position])
	++m_position;
	ASSERT(m_position <= m_table->numberOfValues);
	}

	const HashTable* m_table;
	int m_position;
	};

	ConstIterator begin() const
	{
	initializeIfNeeded();
	return ConstIterator(this, 0);
	}
	ConstIterator end() const
	{
	initializeIfNeeded();
	return ConstIterator(this, numberOfValues);
	}

	private:
	// Convert the hash table keys to identifiers.
	JS_EXPORT_PRIVATE void createTable() const;
	};

	JS_EXPORT_PRIVATE bool setUpStaticFunctionSlot(ExecState, const HashTableValue, JSObject* thisObject, PropertyName, PropertySlot&);

	/**
	* This method does it all (looking in the hashtable, checking for function
	* overrides, creating the function or retrieving from cache, calling
	* getValueProperty in case of a non-function property, forwarding to parent if
	* unknown property).
	*/
	template <class ThisImp, class ParentImp>
	inline bool getStaticPropertySlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	const HashTableValue* entry = table.entry(propertyName);

	if (!entry) // not found, forward to parent
	return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

	if (entry->attributes() & BuiltinOrFunction)
	return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);

	if (entry->attributes() & ConstantInteger) {
	slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger()));
	return true;
	}

	slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
	return true;
	}

	/**
	* Simplified version of getStaticPropertySlot in case there are only functions.
	* Using this instead of getStaticPropertySlot allows 'this' to avoid implementing
	* a dummy getValueProperty.
	*/
	template <class ParentImp>
	inline bool getStaticFunctionSlot(ExecState* exec, const HashTable& table, JSObject* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	if (ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot))
	return true;

	const HashTableValue* entry = table.entry(propertyName);
	if (!entry)
	return false;

	return setUpStaticFunctionSlot(exec, entry, thisObj, propertyName, slot);
	}

	/**
	* Simplified version of getStaticPropertySlot in case there are no functions, only "values".
	* Using this instead of getStaticPropertySlot removes the need for a FuncImp class.
	*/
	template <class ThisImp, class ParentImp>
	inline bool getStaticValueSlot(ExecState* exec, const HashTable& table, ThisImp* thisObj, PropertyName propertyName, PropertySlot& slot)
	{
	const HashTableValue* entry = table.entry(propertyName);

	if (!entry) // not found, forward to parent
	return ParentImp::getOwnPropertySlot(thisObj, exec, propertyName, slot);

	ASSERT(!(entry->attributes() & BuiltinOrFunction));

	if (entry->attributes() & ConstantInteger) {
	slot.setValue(thisObj, entry->attributes(), jsNumber(entry->constantInteger()));
	return true;
	}

	slot.setCacheableCustom(thisObj, entry->attributes(), entry->propertyGetter());
	return true;
	}

	inline void putEntry(ExecState* exec, const HashTableValue* entry, JSObject* base, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
	{
	// If this is a function put it as an override property.
	if (entry->attributes() & BuiltinOrFunction) {
	if (JSObject* thisObject = jsDynamicCast<JSObject*>(slot.thisValue()))
	thisObject->putDirect(exec->vm(), propertyName, value);
	} else if (!(entry->attributes() & ReadOnly)) {
	entry->propertyPutter()(exec, base, JSValue::encode(slot.thisValue()), JSValue::encode(value));
	slot.setCustomProperty(base, entry->propertyPutter());
	} else if (slot.isStrictMode())
	throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
	}

	/**
	* This one is for "put".
	* It looks up a hash entry for the property to be set. If an entry
	* is found it sets the value and returns true, else it returns false.
	*/
	inline bool lookupPut(ExecState* exec, PropertyName propertyName, JSObject* base, JSValue value, const HashTable& table, PutPropertySlot& slot)
	{
	const HashTableValue* entry = table.entry(propertyName);

	if (!entry)
	return false;

	putEntry(exec, entry, base, propertyName, value, slot);
	return true;
	}

	template<unsigned numberOfValues>
	inline void reifyStaticProperties(VM& vm, const HashTableValue (&values)[numberOfValues], JSObject& thisObj)
	{
	BatchedTransitionOptimizer transitionOptimizer(vm, &thisObj);
	for (auto& value : values) {
	if (!value.m_key)
	continue;

	Identifier propertyName(&vm, reinterpret_cast<const LChar*>(value.m_key), strlen(value.m_key));
	if (value.attributes() & Builtin) {
	thisObj.putDirectBuiltinFunction(vm, thisObj.globalObject(), propertyName, value.builtinGenerator()(vm), value.attributes());
	continue;
	}

	if (value.attributes() & Function) {
	thisObj.putDirectNativeFunction(vm, thisObj.globalObject(), propertyName, value.functionLength(),
	value.function(), value.intrinsic(), value.attributes());
	continue;
	}

	if (value.attributes() & ConstantInteger) {
	thisObj.putDirect(vm, propertyName, jsNumber(value.constantInteger()), value.attributes());
	continue;
	}

	if (value.attributes() & Accessor) {
	RELEASE_ASSERT_NOT_REACHED();
	continue;
	}

	CustomGetterSetter* customGetterSetter = CustomGetterSetter::create(vm, value.propertyGetter(), value.propertyPutter());
	thisObj.putDirectCustomAccessor(vm, propertyName, customGetterSetter, value.attributes());
	}
	}

	} // namespace JSC

	#endif // Lookup_h