/*
* Copyright (C) 2007 Eric Seidel <eric@webkit.org>
- * Copyright (C) 2007, 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2007, 2008, 2009, 2014 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
#ifndef JSGlobalObject_h
#define JSGlobalObject_h
+#include "ArrayAllocationProfile.h"
+#include "ConstantMode.h"
#include "JSArray.h"
-#include "JSGlobalData.h"
-#include "JSVariableObject.h"
+#include "JSArrayBufferPrototype.h"
+#include "JSClassRef.h"
+#include "JSProxy.h"
+#include "JSSegmentedVariableObject.h"
#include "JSWeakObjectMapRefInternal.h"
-#include "NativeFunctionWrapper.h"
#include "NumberPrototype.h"
+#include "SpecialPointer.h"
#include "StringPrototype.h"
+#include "StructureChain.h"
+#include "StructureRareDataInlines.h"
+#include "VM.h"
+#include "Watchpoint.h"
+#include <JavaScriptCore/JSBase.h>
+#include <array>
#include <wtf/HashSet.h>
#include <wtf/OwnPtr.h>
+#include <wtf/PassRefPtr.h>
#include <wtf/RandomNumber.h>
+struct OpaqueJSClass;
+struct OpaqueJSClassContextData;
+
+namespace Inspector {
+class JSGlobalObjectInspectorController;
+}
+
namespace JSC {
- class ArrayPrototype;
- class BooleanPrototype;
- class DatePrototype;
- class Debugger;
- class ErrorConstructor;
- class FunctionPrototype;
- class GlobalCodeBlock;
- class GlobalEvalFunction;
- class NativeErrorConstructor;
- class ProgramCodeBlock;
- class PrototypeFunction;
- class RegExpConstructor;
- class RegExpPrototype;
- class RegisterFile;
-
- struct ActivationStackNode;
- struct HashTable;
-
- typedef Vector<ExecState*, 16> ExecStateStack;
+class ArrayPrototype;
+class BooleanPrototype;
+class ConsoleClient;
+class Debugger;
+class ErrorConstructor;
+class ErrorPrototype;
+class EvalCodeBlock;
+class EvalExecutable;
+class FunctionCodeBlock;
+class FunctionExecutable;
+class FunctionPrototype;
+class GetterSetter;
+class GlobalCodeBlock;
+class InputCursor;
+class JSGlobalObjectDebuggable;
+class JSPromiseConstructor;
+class JSPromisePrototype;
+class JSStack;
+class LLIntOffsetsExtractor;
+class Microtask;
+class NativeErrorConstructor;
+class ObjectConstructor;
+class ProgramCodeBlock;
+class ProgramExecutable;
+class RegExpConstructor;
+class RegExpPrototype;
+class SourceCode;
+struct ActivationStackNode;
+struct HashTable;
+
+#define DEFINE_STANDARD_BUILTIN(macro, upperName, lowerName) macro(upperName, lowerName, lowerName, JS ## upperName, upperName)
- class JSGlobalObject : public JSVariableObject {
- protected:
- using JSVariableObject::JSVariableObjectData;
- typedef HashSet<RefPtr<OpaqueJSWeakObjectMap> > WeakMapSet;
-
- struct JSGlobalObjectData : public JSVariableObjectData {
- // We use an explicit destructor function pointer instead of a
- // virtual destructor because we want to avoid adding a vtable
- // pointer to this struct. Adding a vtable pointer would force the
- // compiler to emit costly pointer fixup code when casting from
- // JSVariableObjectData* to JSGlobalObjectData*.
- typedef void (*Destructor)(void*);
-
- JSGlobalObjectData(Destructor destructor)
- : JSVariableObjectData(&symbolTable, 0)
- , destructor(destructor)
- , registerArraySize(0)
- , globalScopeChain(NoScopeChain())
- , regExpConstructor(0)
- , errorConstructor(0)
- , evalErrorConstructor(0)
- , rangeErrorConstructor(0)
- , referenceErrorConstructor(0)
- , syntaxErrorConstructor(0)
- , typeErrorConstructor(0)
- , URIErrorConstructor(0)
- , evalFunction(0)
- , callFunction(0)
- , applyFunction(0)
- , objectPrototype(0)
- , functionPrototype(0)
- , arrayPrototype(0)
- , booleanPrototype(0)
- , stringPrototype(0)
- , numberPrototype(0)
- , datePrototype(0)
- , regExpPrototype(0)
- , methodCallDummy(0)
- , weakRandom(static_cast<unsigned>(randomNumber() * (std::numeric_limits<unsigned>::max() + 1.0)))
- {
- }
-
- Destructor destructor;
-
- size_t registerArraySize;
-
- JSGlobalObject* next;
- JSGlobalObject* prev;
-
- Debugger* debugger;
-
- ScopeChain globalScopeChain;
- Register globalCallFrame[RegisterFile::CallFrameHeaderSize];
-
- int recursion;
-
- RegExpConstructor* regExpConstructor;
- ErrorConstructor* errorConstructor;
- NativeErrorConstructor* evalErrorConstructor;
- NativeErrorConstructor* rangeErrorConstructor;
- NativeErrorConstructor* referenceErrorConstructor;
- NativeErrorConstructor* syntaxErrorConstructor;
- NativeErrorConstructor* typeErrorConstructor;
- NativeErrorConstructor* URIErrorConstructor;
-
- GlobalEvalFunction* evalFunction;
- NativeFunctionWrapper* callFunction;
- NativeFunctionWrapper* applyFunction;
-
- ObjectPrototype* objectPrototype;
- FunctionPrototype* functionPrototype;
- ArrayPrototype* arrayPrototype;
- BooleanPrototype* booleanPrototype;
- StringPrototype* stringPrototype;
- NumberPrototype* numberPrototype;
- DatePrototype* datePrototype;
- RegExpPrototype* regExpPrototype;
-
- JSObject* methodCallDummy;
-
- RefPtr<Structure> argumentsStructure;
- RefPtr<Structure> arrayStructure;
- RefPtr<Structure> booleanObjectStructure;
- RefPtr<Structure> callbackConstructorStructure;
- RefPtr<Structure> callbackFunctionStructure;
- RefPtr<Structure> callbackObjectStructure;
- RefPtr<Structure> dateStructure;
- RefPtr<Structure> emptyObjectStructure;
- RefPtr<Structure> errorStructure;
- RefPtr<Structure> functionStructure;
- RefPtr<Structure> numberObjectStructure;
- RefPtr<Structure> prototypeFunctionStructure;
- RefPtr<Structure> regExpMatchesArrayStructure;
- RefPtr<Structure> regExpStructure;
- RefPtr<Structure> stringObjectStructure;
-
- SymbolTable symbolTable;
- unsigned profileGroup;
-
- RefPtr<JSGlobalData> globalData;
-
- HashSet<GlobalCodeBlock*> codeBlocks;
- WeakMapSet weakMaps;
- WeakRandom weakRandom;
- };
-
- public:
- void* operator new(size_t, JSGlobalData*);
-
- explicit JSGlobalObject()
- : JSVariableObject(JSGlobalObject::createStructure(jsNull()), new JSGlobalObjectData(destroyJSGlobalObjectData))
- {
- init(this);
- }
+#define FOR_EACH_SIMPLE_BUILTIN_TYPE_WITH_CONSTRUCTOR(macro) \
+ macro(Set, set, set, JSSet, Set) \
+ macro(Map, map, map, JSMap, Map) \
+ macro(Date, date, date, DateInstance, Date) \
+ macro(String, string, stringObject, StringObject, String) \
+ macro(Boolean, boolean, booleanObject, BooleanObject, Boolean) \
+ macro(Number, number, numberObject, NumberObject, Number) \
+ macro(Error, error, error, ErrorInstance, Error) \
+ macro(JSArrayBuffer, arrayBuffer, arrayBuffer, JSArrayBuffer, ArrayBuffer) \
+ DEFINE_STANDARD_BUILTIN(macro, WeakMap, weakMap) \
- protected:
- JSGlobalObject(NonNullPassRefPtr<Structure> structure, JSGlobalObjectData* data, JSObject* thisValue)
- : JSVariableObject(structure, data)
- {
- init(thisValue);
- }
+#define FOR_EACH_SIMPLE_BUILTIN_TYPE(macro) \
+ FOR_EACH_SIMPLE_BUILTIN_TYPE_WITH_CONSTRUCTOR(macro) \
+ DEFINE_STANDARD_BUILTIN(macro, ArrayIterator, arrayIterator) \
+ DEFINE_STANDARD_BUILTIN(macro, ArgumentsIterator, argumentsIterator) \
+ DEFINE_STANDARD_BUILTIN(macro, MapIterator, mapIterator) \
+ DEFINE_STANDARD_BUILTIN(macro, SetIterator, setIterator) \
- public:
- virtual ~JSGlobalObject();
-
- virtual void markChildren(MarkStack&);
-
- virtual bool getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&);
- virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
- virtual bool hasOwnPropertyForWrite(ExecState*, const Identifier&);
- virtual void put(ExecState*, const Identifier&, JSValue, PutPropertySlot&);
- virtual void putWithAttributes(ExecState*, const Identifier& propertyName, JSValue value, unsigned attributes);
-
- virtual void defineGetter(ExecState*, const Identifier& propertyName, JSObject* getterFunc, unsigned attributes);
- virtual void defineSetter(ExecState*, const Identifier& propertyName, JSObject* setterFunc, unsigned attributes);
-
- // Linked list of all global objects that use the same JSGlobalData.
- JSGlobalObject*& head() { return d()->globalData->head; }
- JSGlobalObject* next() { return d()->next; }
-
- // The following accessors return pristine values, even if a script
- // replaces the global object's associated property.
-
- RegExpConstructor* regExpConstructor() const { return d()->regExpConstructor; }
-
- ErrorConstructor* errorConstructor() const { return d()->errorConstructor; }
- NativeErrorConstructor* evalErrorConstructor() const { return d()->evalErrorConstructor; }
- NativeErrorConstructor* rangeErrorConstructor() const { return d()->rangeErrorConstructor; }
- NativeErrorConstructor* referenceErrorConstructor() const { return d()->referenceErrorConstructor; }
- NativeErrorConstructor* syntaxErrorConstructor() const { return d()->syntaxErrorConstructor; }
- NativeErrorConstructor* typeErrorConstructor() const { return d()->typeErrorConstructor; }
- NativeErrorConstructor* URIErrorConstructor() const { return d()->URIErrorConstructor; }
-
- GlobalEvalFunction* evalFunction() const { return d()->evalFunction; }
-
- ObjectPrototype* objectPrototype() const { return d()->objectPrototype; }
- FunctionPrototype* functionPrototype() const { return d()->functionPrototype; }
- ArrayPrototype* arrayPrototype() const { return d()->arrayPrototype; }
- BooleanPrototype* booleanPrototype() const { return d()->booleanPrototype; }
- StringPrototype* stringPrototype() const { return d()->stringPrototype; }
- NumberPrototype* numberPrototype() const { return d()->numberPrototype; }
- DatePrototype* datePrototype() const { return d()->datePrototype; }
- RegExpPrototype* regExpPrototype() const { return d()->regExpPrototype; }
-
- JSObject* methodCallDummy() const { return d()->methodCallDummy; }
-
- Structure* argumentsStructure() const { return d()->argumentsStructure.get(); }
- Structure* arrayStructure() const { return d()->arrayStructure.get(); }
- Structure* booleanObjectStructure() const { return d()->booleanObjectStructure.get(); }
- Structure* callbackConstructorStructure() const { return d()->callbackConstructorStructure.get(); }
- Structure* callbackFunctionStructure() const { return d()->callbackFunctionStructure.get(); }
- Structure* callbackObjectStructure() const { return d()->callbackObjectStructure.get(); }
- Structure* dateStructure() const { return d()->dateStructure.get(); }
- Structure* emptyObjectStructure() const { return d()->emptyObjectStructure.get(); }
- Structure* errorStructure() const { return d()->errorStructure.get(); }
- Structure* functionStructure() const { return d()->functionStructure.get(); }
- Structure* numberObjectStructure() const { return d()->numberObjectStructure.get(); }
- Structure* prototypeFunctionStructure() const { return d()->prototypeFunctionStructure.get(); }
- Structure* regExpMatchesArrayStructure() const { return d()->regExpMatchesArrayStructure.get(); }
- Structure* regExpStructure() const { return d()->regExpStructure.get(); }
- Structure* stringObjectStructure() const { return d()->stringObjectStructure.get(); }
-
- void setProfileGroup(unsigned value) { d()->profileGroup = value; }
- unsigned profileGroup() const { return d()->profileGroup; }
-
- Debugger* debugger() const { return d()->debugger; }
- void setDebugger(Debugger* debugger) { d()->debugger = debugger; }
-
- virtual bool supportsProfiling() const { return false; }
-
- int recursion() { return d()->recursion; }
- void incRecursion() { ++d()->recursion; }
- void decRecursion() { --d()->recursion; }
-
- ScopeChain& globalScopeChain() { return d()->globalScopeChain; }
- virtual bool isGlobalObject() const { return true; }
+#define DECLARE_SIMPLE_BUILTIN_TYPE(capitalName, lowerName, properName, instanceType, jsName) \
+ class JS ## capitalName; \
+ class capitalName ## Prototype; \
+ class capitalName ## Constructor;
- virtual ExecState* globalExec();
+FOR_EACH_SIMPLE_BUILTIN_TYPE(DECLARE_SIMPLE_BUILTIN_TYPE)
- virtual bool shouldInterruptScriptBeforeTimeout() const { return false; }
- virtual bool shouldInterruptScript() const { return true; }
+#undef DECLARE_SIMPLE_BUILTIN_TYPE
- virtual bool allowsAccessFrom(const JSGlobalObject*) const { return true; }
+typedef Vector<ExecState*, 16> ExecStateStack;
- virtual bool isDynamicScope(bool& requiresDynamicChecks) const;
+struct GlobalObjectMethodTable {
+ typedef bool (*AllowsAccessFromFunctionPtr)(const JSGlobalObject*, ExecState*);
+ AllowsAccessFromFunctionPtr allowsAccessFrom;
- HashSet<GlobalCodeBlock*>& codeBlocks() { return d()->codeBlocks; }
+ typedef bool (*SupportsProfilingFunctionPtr)(const JSGlobalObject*);
+ SupportsProfilingFunctionPtr supportsProfiling;
- void copyGlobalsFrom(RegisterFile&);
- void copyGlobalsTo(RegisterFile&);
-
- void resetPrototype(JSValue prototype);
+ typedef bool (*SupportsRichSourceInfoFunctionPtr)(const JSGlobalObject*);
+ SupportsRichSourceInfoFunctionPtr supportsRichSourceInfo;
- JSGlobalData* globalData() { return d()->globalData.get(); }
- JSGlobalObjectData* d() const { return static_cast<JSGlobalObjectData*>(JSVariableObject::d); }
+ typedef bool (*ShouldInterruptScriptFunctionPtr)(const JSGlobalObject*);
+ ShouldInterruptScriptFunctionPtr shouldInterruptScript;
- static PassRefPtr<Structure> createStructure(JSValue prototype)
- {
- return Structure::create(prototype, TypeInfo(ObjectType, StructureFlags), AnonymousSlotCount);
- }
+ typedef bool (*JavaScriptExperimentsEnabledFunctionPtr)(const JSGlobalObject*);
+ JavaScriptExperimentsEnabledFunctionPtr javaScriptExperimentsEnabled;
- void registerWeakMap(OpaqueJSWeakObjectMap* map)
- {
- d()->weakMaps.add(map);
- }
+ typedef void (*QueueTaskToEventLoopFunctionPtr)(const JSGlobalObject*, PassRefPtr<Microtask>);
+ QueueTaskToEventLoopFunctionPtr queueTaskToEventLoop;
+
+ typedef bool (*ShouldInterruptScriptBeforeTimeoutPtr)(const JSGlobalObject*);
+ ShouldInterruptScriptBeforeTimeoutPtr shouldInterruptScriptBeforeTimeout;
+};
- void deregisterWeakMap(OpaqueJSWeakObjectMap* map)
+class JSGlobalObject : public JSSegmentedVariableObject {
+private:
+ typedef HashSet<RefPtr<OpaqueJSWeakObjectMap>> WeakMapSet;
+ typedef HashMap<OpaqueJSClass*, std::unique_ptr<OpaqueJSClassContextData>> OpaqueJSClassDataMap;
+
+ struct JSGlobalObjectRareData {
+ JSGlobalObjectRareData()
+ : profileGroup(0)
{
- d()->weakMaps.remove(map);
}
- double weakRandomNumber() { return d()->weakRandom.get(); }
- protected:
+ WeakMapSet weakMaps;
+ unsigned profileGroup;
+
+ OpaqueJSClassDataMap opaqueJSClassData;
+ };
- static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesMarkChildren | OverridesGetPropertyNames | JSVariableObject::StructureFlags;
+protected:
+ Register m_globalCallFrame[JSStack::CallFrameHeaderSize];
+
+ WriteBarrier<JSObject> m_globalThis;
+
+ WriteBarrier<RegExpConstructor> m_regExpConstructor;
+ WriteBarrier<ErrorConstructor> m_errorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_evalErrorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_rangeErrorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_referenceErrorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_syntaxErrorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_typeErrorConstructor;
+ WriteBarrier<NativeErrorConstructor> m_URIErrorConstructor;
+#if ENABLE(PROMISES)
+ WriteBarrier<JSPromiseConstructor> m_promiseConstructor;
+#endif
+ WriteBarrier<ObjectConstructor> m_objectConstructor;
+
+ WriteBarrier<JSFunction> m_evalFunction;
+ WriteBarrier<JSFunction> m_callFunction;
+ WriteBarrier<JSFunction> m_applyFunction;
+ WriteBarrier<GetterSetter> m_throwTypeErrorGetterSetter;
+
+ WriteBarrier<ObjectPrototype> m_objectPrototype;
+ WriteBarrier<FunctionPrototype> m_functionPrototype;
+ WriteBarrier<ArrayPrototype> m_arrayPrototype;
+ WriteBarrier<RegExpPrototype> m_regExpPrototype;
+#if ENABLE(PROMISES)
+ WriteBarrier<JSPromisePrototype> m_promisePrototype;
+#endif
- struct GlobalPropertyInfo {
- GlobalPropertyInfo(const Identifier& i, JSValue v, unsigned a)
- : identifier(i)
- , value(v)
- , attributes(a)
- {
- }
+ WriteBarrier<Structure> m_withScopeStructure;
+ WriteBarrier<Structure> m_strictEvalActivationStructure;
+ WriteBarrier<Structure> m_activationStructure;
+ WriteBarrier<Structure> m_nameScopeStructure;
+ WriteBarrier<Structure> m_argumentsStructure;
+
+ // Lists the actual structures used for having these particular indexing shapes.
+ WriteBarrier<Structure> m_originalArrayStructureForIndexingShape[NumberOfIndexingShapes];
+ // Lists the structures we should use during allocation for these particular indexing shapes.
+ WriteBarrier<Structure> m_arrayStructureForIndexingShapeDuringAllocation[NumberOfIndexingShapes];
+
+ WriteBarrier<Structure> m_callbackConstructorStructure;
+ WriteBarrier<Structure> m_callbackFunctionStructure;
+ WriteBarrier<Structure> m_callbackObjectStructure;
+#if JSC_OBJC_API_ENABLED
+ WriteBarrier<Structure> m_objcCallbackFunctionStructure;
+ WriteBarrier<Structure> m_objcWrapperObjectStructure;
+#endif
+ WriteBarrier<Structure> m_nullPrototypeObjectStructure;
+ WriteBarrier<Structure> m_functionStructure;
+ WriteBarrier<Structure> m_boundFunctionStructure;
+ WriteBarrier<Structure> m_namedFunctionStructure;
+ PropertyOffset m_functionNameOffset;
+ WriteBarrier<Structure> m_privateNameStructure;
+ WriteBarrier<Structure> m_regExpMatchesArrayStructure;
+ WriteBarrier<Structure> m_regExpStructure;
+ WriteBarrier<Structure> m_consoleStructure;
+ WriteBarrier<Structure> m_internalFunctionStructure;
+
+ WriteBarrier<Structure> m_iteratorResultStructure;
- const Identifier identifier;
- JSValue value;
- unsigned attributes;
- };
- void addStaticGlobals(GlobalPropertyInfo*, int count);
+#if ENABLE(PROMISES)
+ WriteBarrier<Structure> m_promiseStructure;
+#endif // ENABLE(PROMISES)
- private:
- static void destroyJSGlobalObjectData(void*);
+#define DEFINE_STORAGE_FOR_SIMPLE_TYPE(capitalName, lowerName, properName, instanceType, jsName) \
+ WriteBarrier<capitalName ## Prototype> m_ ## lowerName ## Prototype; \
+ WriteBarrier<Structure> m_ ## properName ## Structure;
- // FIXME: Fold reset into init.
- void init(JSObject* thisValue);
- void reset(JSValue prototype);
+ FOR_EACH_SIMPLE_BUILTIN_TYPE(DEFINE_STORAGE_FOR_SIMPLE_TYPE)
- void setRegisters(Register* registers, Register* registerArray, size_t count);
+#undef DEFINE_STORAGE_FOR_SIMPLE_TYPE
- void* operator new(size_t); // can only be allocated with JSGlobalData
+ struct TypedArrayData {
+ WriteBarrier<JSObject> prototype;
+ WriteBarrier<Structure> structure;
};
+
+ std::array<TypedArrayData, NUMBER_OF_TYPED_ARRAY_TYPES> m_typedArrays;
+
+ void* m_specialPointers[Special::TableSize]; // Special pointers used by the LLInt and JIT.
+
+ String m_name;
+
+ Debugger* m_debugger;
+
+ VM& m_vm;
+
+#if ENABLE(WEB_REPLAY)
+ RefPtr<InputCursor> m_inputCursor;
+#endif
+
+#if ENABLE(REMOTE_INSPECTOR)
+ std::unique_ptr<Inspector::JSGlobalObjectInspectorController> m_inspectorController;
+ std::unique_ptr<JSGlobalObjectDebuggable> m_inspectorDebuggable;
+#endif
+
+ RefPtr<WatchpointSet> m_masqueradesAsUndefinedWatchpoint;
+ RefPtr<WatchpointSet> m_havingABadTimeWatchpoint;
+ RefPtr<WatchpointSet> m_varInjectionWatchpoint;
+
+ OwnPtr<JSGlobalObjectRareData> m_rareData;
+
+ WeakRandom m_weakRandom;
+
+ bool m_evalEnabled;
+ String m_evalDisabledErrorMessage;
+ bool m_experimentsEnabled;
+ ConsoleClient* m_consoleClient;
- JSGlobalObject* asGlobalObject(JSValue);
+ static JS_EXPORTDATA const GlobalObjectMethodTable s_globalObjectMethodTable;
+ const GlobalObjectMethodTable* m_globalObjectMethodTable;
- inline JSGlobalObject* asGlobalObject(JSValue value)
+ void createRareDataIfNeeded()
{
- ASSERT(asObject(value)->isGlobalObject());
- return static_cast<JSGlobalObject*>(asObject(value));
+ if (m_rareData)
+ return;
+ m_rareData = adoptPtr(new JSGlobalObjectRareData);
}
+
+public:
+ typedef JSSegmentedVariableObject Base;
- inline void JSGlobalObject::setRegisters(Register* registers, Register* registerArray, size_t count)
+ static JSGlobalObject* create(VM& vm, Structure* structure)
{
- JSVariableObject::setRegisters(registers, registerArray);
- d()->registerArraySize = count;
+ JSGlobalObject* globalObject = new (NotNull, allocateCell<JSGlobalObject>(vm.heap)) JSGlobalObject(vm, structure);
+ globalObject->finishCreation(vm);
+ vm.heap.addFinalizer(globalObject, destroy);
+ return globalObject;
}
- inline void JSGlobalObject::addStaticGlobals(GlobalPropertyInfo* globals, int count)
+ DECLARE_EXPORT_INFO;
+
+ bool hasDebugger() const { return m_debugger; }
+ bool hasProfiler() const { return globalObjectMethodTable()->supportsProfiling(this); }
+
+protected:
+ JS_EXPORT_PRIVATE explicit JSGlobalObject(VM&, Structure*, const GlobalObjectMethodTable* = 0);
+
+ void finishCreation(VM& vm)
{
- size_t oldSize = d()->registerArraySize;
- size_t newSize = oldSize + count;
- Register* registerArray = new Register[newSize];
- if (d()->registerArray)
- memcpy(registerArray + count, d()->registerArray.get(), oldSize * sizeof(Register));
- setRegisters(registerArray + newSize, registerArray, newSize);
-
- for (int i = 0, index = -static_cast<int>(oldSize) - 1; i < count; ++i, --index) {
- GlobalPropertyInfo& global = globals[i];
- ASSERT(global.attributes & DontDelete);
- SymbolTableEntry newEntry(index, global.attributes);
- symbolTable().add(global.identifier.ustring().rep(), newEntry);
- registerAt(index) = global.value;
- }
+ Base::finishCreation(vm);
+ structure()->setGlobalObject(vm, this);
+ m_experimentsEnabled = m_globalObjectMethodTable->javaScriptExperimentsEnabled(this);
+ init();
+ setGlobalThis(vm, JSProxy::create(vm, JSProxy::createStructure(vm, this, prototype(), PureForwardingProxyType), this));
}
- inline bool JSGlobalObject::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
+ void finishCreation(VM& vm, JSObject* thisValue)
{
- if (JSVariableObject::getOwnPropertySlot(exec, propertyName, slot))
- return true;
- return symbolTableGet(propertyName, slot);
+ Base::finishCreation(vm);
+ structure()->setGlobalObject(vm, this);
+ m_experimentsEnabled = m_globalObjectMethodTable->javaScriptExperimentsEnabled(this);
+ init();
+ setGlobalThis(vm, thisValue);
}
- inline bool JSGlobalObject::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
+ struct NewGlobalVar {
+ int registerNumber;
+ VariableWatchpointSet* set;
+ };
+ NewGlobalVar addGlobalVar(const Identifier&, ConstantMode);
+
+public:
+ JS_EXPORT_PRIVATE ~JSGlobalObject();
+ JS_EXPORT_PRIVATE static void destroy(JSCell*);
+ // We don't need a destructor because we use a finalizer instead.
+ static const bool needsDestruction = false;
+
+ JS_EXPORT_PRIVATE static void visitChildren(JSCell*, SlotVisitor&);
+
+ JS_EXPORT_PRIVATE static bool getOwnPropertySlot(JSObject*, ExecState*, PropertyName, PropertySlot&);
+ bool hasOwnPropertyForWrite(ExecState*, PropertyName);
+ JS_EXPORT_PRIVATE static void put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&);
+
+ JS_EXPORT_PRIVATE static void defineGetter(JSObject*, ExecState*, PropertyName, JSObject* getterFunc, unsigned attributes);
+ JS_EXPORT_PRIVATE static void defineSetter(JSObject*, ExecState*, PropertyName, JSObject* setterFunc, unsigned attributes);
+ JS_EXPORT_PRIVATE static bool defineOwnProperty(JSObject*, ExecState*, PropertyName, const PropertyDescriptor&, bool shouldThrow);
+
+ // We use this in the code generator as we perform symbol table
+ // lookups prior to initializing the properties
+ bool symbolTableHasProperty(PropertyName);
+
+ void addVar(ExecState* exec, const Identifier& propertyName)
{
- if (symbolTableGet(propertyName, descriptor))
- return true;
- return JSVariableObject::getOwnPropertyDescriptor(exec, propertyName, descriptor);
+ if (!hasProperty(exec, propertyName))
+ addGlobalVar(propertyName, IsVariable);
}
-
- inline bool JSGlobalObject::hasOwnPropertyForWrite(ExecState* exec, const Identifier& propertyName)
+ void addConst(ExecState* exec, const Identifier& propertyName)
{
- PropertySlot slot;
- if (JSVariableObject::getOwnPropertySlot(exec, propertyName, slot))
- return true;
- bool slotIsWriteable;
- return symbolTableGet(propertyName, slot, slotIsWriteable);
+ if (!hasProperty(exec, propertyName))
+ addGlobalVar(propertyName, IsConstant);
}
+ void addFunction(ExecState*, const Identifier&, JSValue);
+
+ // The following accessors return pristine values, even if a script
+ // replaces the global object's associated property.
+
+ RegExpConstructor* regExpConstructor() const { return m_regExpConstructor.get(); }
+
+ ErrorConstructor* errorConstructor() const { return m_errorConstructor.get(); }
+ ObjectConstructor* objectConstructor() const { return m_objectConstructor.get(); }
+ NativeErrorConstructor* evalErrorConstructor() const { return m_evalErrorConstructor.get(); }
+ NativeErrorConstructor* rangeErrorConstructor() const { return m_rangeErrorConstructor.get(); }
+ NativeErrorConstructor* referenceErrorConstructor() const { return m_referenceErrorConstructor.get(); }
+ NativeErrorConstructor* syntaxErrorConstructor() const { return m_syntaxErrorConstructor.get(); }
+ NativeErrorConstructor* typeErrorConstructor() const { return m_typeErrorConstructor.get(); }
+ NativeErrorConstructor* URIErrorConstructor() const { return m_URIErrorConstructor.get(); }
+#if ENABLE(PROMISES)
+ JSPromiseConstructor* promiseConstructor() const { return m_promiseConstructor.get(); }
+#endif
- inline JSValue Structure::prototypeForLookup(ExecState* exec) const
+ JSFunction* evalFunction() const { return m_evalFunction.get(); }
+ JSFunction* callFunction() const { return m_callFunction.get(); }
+ JSFunction* applyFunction() const { return m_applyFunction.get(); }
+ GetterSetter* throwTypeErrorGetterSetter(VM& vm)
{
- if (typeInfo().type() == ObjectType)
- return m_prototype;
-
-#if USE(JSVALUE32)
- if (typeInfo().type() == StringType)
- return exec->lexicalGlobalObject()->stringPrototype();
-
- ASSERT(typeInfo().type() == NumberType);
- return exec->lexicalGlobalObject()->numberPrototype();
-#else
- ASSERT(typeInfo().type() == StringType);
- return exec->lexicalGlobalObject()->stringPrototype();
-#endif
+ if (!m_throwTypeErrorGetterSetter)
+ createThrowTypeError(vm);
+ return m_throwTypeErrorGetterSetter.get();
}
- inline StructureChain* Structure::prototypeChain(ExecState* exec) const
+ ObjectPrototype* objectPrototype() const { return m_objectPrototype.get(); }
+ FunctionPrototype* functionPrototype() const { return m_functionPrototype.get(); }
+ ArrayPrototype* arrayPrototype() const { return m_arrayPrototype.get(); }
+ BooleanPrototype* booleanPrototype() const { return m_booleanPrototype.get(); }
+ StringPrototype* stringPrototype() const { return m_stringPrototype.get(); }
+ NumberPrototype* numberPrototype() const { return m_numberPrototype.get(); }
+ DatePrototype* datePrototype() const { return m_datePrototype.get(); }
+ RegExpPrototype* regExpPrototype() const { return m_regExpPrototype.get(); }
+ ErrorPrototype* errorPrototype() const { return m_errorPrototype.get(); }
+#if ENABLE(PROMISES)
+ JSPromisePrototype* promisePrototype() const { return m_promisePrototype.get(); }
+#endif
+
+ Structure* withScopeStructure() const { return m_withScopeStructure.get(); }
+ Structure* strictEvalActivationStructure() const { return m_strictEvalActivationStructure.get(); }
+ Structure* activationStructure() const { return m_activationStructure.get(); }
+ Structure* nameScopeStructure() const { return m_nameScopeStructure.get(); }
+ Structure* argumentsStructure() const { return m_argumentsStructure.get(); }
+ Structure* originalArrayStructureForIndexingType(IndexingType indexingType) const
{
- // We cache our prototype chain so our clients can share it.
- if (!isValid(exec, m_cachedPrototypeChain.get())) {
- JSValue prototype = prototypeForLookup(exec);
- m_cachedPrototypeChain = StructureChain::create(prototype.isNull() ? 0 : asObject(prototype)->structure());
- }
- return m_cachedPrototypeChain.get();
+ ASSERT(indexingType & IsArray);
+ return m_originalArrayStructureForIndexingShape[(indexingType & IndexingShapeMask) >> IndexingShapeShift].get();
+ }
+ Structure* arrayStructureForIndexingTypeDuringAllocation(IndexingType indexingType) const
+ {
+ ASSERT(indexingType & IsArray);
+ return m_arrayStructureForIndexingShapeDuringAllocation[(indexingType & IndexingShapeMask) >> IndexingShapeShift].get();
+ }
+ Structure* arrayStructureForProfileDuringAllocation(ArrayAllocationProfile* profile) const
+ {
+ return arrayStructureForIndexingTypeDuringAllocation(ArrayAllocationProfile::selectIndexingTypeFor(profile));
+ }
+
+ bool isOriginalArrayStructure(Structure* structure)
+ {
+ return originalArrayStructureForIndexingType(structure->indexingType() | IsArray) == structure;
}
+
+ Structure* booleanObjectStructure() const { return m_booleanObjectStructure.get(); }
+ Structure* callbackConstructorStructure() const { return m_callbackConstructorStructure.get(); }
+ Structure* callbackFunctionStructure() const { return m_callbackFunctionStructure.get(); }
+ Structure* callbackObjectStructure() const { return m_callbackObjectStructure.get(); }
+#if JSC_OBJC_API_ENABLED
+ Structure* objcCallbackFunctionStructure() const { return m_objcCallbackFunctionStructure.get(); }
+ Structure* objcWrapperObjectStructure() const { return m_objcWrapperObjectStructure.get(); }
+#endif
+ Structure* dateStructure() const { return m_dateStructure.get(); }
+ Structure* nullPrototypeObjectStructure() const { return m_nullPrototypeObjectStructure.get(); }
+ Structure* errorStructure() const { return m_errorStructure.get(); }
+ Structure* functionStructure() const { return m_functionStructure.get(); }
+ Structure* boundFunctionStructure() const { return m_boundFunctionStructure.get(); }
+ Structure* namedFunctionStructure() const { return m_namedFunctionStructure.get(); }
+ PropertyOffset functionNameOffset() const { return m_functionNameOffset; }
+ Structure* numberObjectStructure() const { return m_numberObjectStructure.get(); }
+ Structure* privateNameStructure() const { return m_privateNameStructure.get(); }
+ Structure* internalFunctionStructure() const { return m_internalFunctionStructure.get(); }
+ Structure* mapStructure() const { return m_mapStructure.get(); }
+ Structure* regExpMatchesArrayStructure() const { return m_regExpMatchesArrayStructure.get(); }
+ Structure* regExpStructure() const { return m_regExpStructure.get(); }
+ Structure* setStructure() const { return m_setStructure.get(); }
+ Structure* stringObjectStructure() const { return m_stringObjectStructure.get(); }
+ Structure* iteratorResultStructure() const { return m_iteratorResultStructure.get(); }
+ static ptrdiff_t iteratorResultStructureOffset() { return OBJECT_OFFSETOF(JSGlobalObject, m_iteratorResultStructure); }
+
+#if ENABLE(PROMISES)
+ Structure* promiseStructure() const { return m_promiseStructure.get(); }
+#endif // ENABLE(PROMISES)
+
+ JS_EXPORT_PRIVATE void setRemoteDebuggingEnabled(bool);
+ JS_EXPORT_PRIVATE bool remoteDebuggingEnabled() const;
+
+#if ENABLE(WEB_REPLAY)
+ JS_EXPORT_PRIVATE void setInputCursor(PassRefPtr<InputCursor>);
+ InputCursor& inputCursor() const { return *m_inputCursor; }
+#endif
+
+#if ENABLE(REMOTE_INSPECTOR)
+ Inspector::JSGlobalObjectInspectorController& inspectorController() const { return *m_inspectorController.get(); }
+ JSGlobalObjectDebuggable& inspectorDebuggable() { return *m_inspectorDebuggable.get(); }
+#endif
+
+ JS_EXPORT_PRIVATE void setConsoleClient(ConsoleClient* consoleClient) { m_consoleClient = consoleClient; }
+ ConsoleClient* consoleClient() const { return m_consoleClient; }
+
+ void setName(const String&);
+ const String& name() const { return m_name; }
+
+ JSArrayBufferPrototype* arrayBufferPrototype() const { return m_arrayBufferPrototype.get(); }
+
+#define DEFINE_ACCESSORS_FOR_SIMPLE_TYPE(capitalName, lowerName, properName, instanceType, jsName) \
+ Structure* properName ## Structure() { return m_ ## properName ## Structure.get(); }
+
+ FOR_EACH_SIMPLE_BUILTIN_TYPE(DEFINE_ACCESSORS_FOR_SIMPLE_TYPE)
+
+#undef DEFINE_ACCESSORS_FOR_SIMPLE_TYPE
- inline bool Structure::isValid(ExecState* exec, StructureChain* cachedPrototypeChain) const
+ Structure* typedArrayStructure(TypedArrayType type) const
{
- if (!cachedPrototypeChain)
+ return m_typedArrays[toIndex(type)].structure.get();
+ }
+ bool isOriginalTypedArrayStructure(Structure* structure)
+ {
+ TypedArrayType type = structure->classInfo()->typedArrayStorageType;
+ if (type == NotTypedArray)
return false;
-
- JSValue prototype = prototypeForLookup(exec);
- RefPtr<Structure>* cachedStructure = cachedPrototypeChain->head();
- while(*cachedStructure && !prototype.isNull()) {
- if (asObject(prototype)->structure() != *cachedStructure)
- return false;
- ++cachedStructure;
- prototype = asObject(prototype)->prototype();
- }
- return prototype.isNull() && !*cachedStructure;
+ return typedArrayStructure(type) == structure;
}
- inline JSGlobalObject* ExecState::dynamicGlobalObject()
+ void* actualPointerFor(Special::Pointer pointer)
{
- if (this == lexicalGlobalObject()->globalExec())
- return lexicalGlobalObject();
-
- // For any ExecState that's not a globalExec, the
- // dynamic global object must be set since code is running
- ASSERT(globalData().dynamicGlobalObject);
- return globalData().dynamicGlobalObject;
+ ASSERT(pointer < Special::TableSize);
+ return m_specialPointers[pointer];
}
- inline JSObject* constructEmptyObject(ExecState* exec)
+ WatchpointSet* masqueradesAsUndefinedWatchpoint() { return m_masqueradesAsUndefinedWatchpoint.get(); }
+ WatchpointSet* havingABadTimeWatchpoint() { return m_havingABadTimeWatchpoint.get(); }
+ WatchpointSet* varInjectionWatchpoint() { return m_varInjectionWatchpoint.get(); }
+
+ bool isHavingABadTime() const
{
- return new (exec) JSObject(exec->lexicalGlobalObject()->emptyObjectStructure());
+ return m_havingABadTimeWatchpoint->hasBeenInvalidated();
}
-
- inline JSObject* constructEmptyObject(ExecState* exec, JSGlobalObject* globalObject)
- {
- return new (exec) JSObject(globalObject->emptyObjectStructure());
+
+ void haveABadTime(VM&);
+
+ bool objectPrototypeIsSane();
+ bool arrayPrototypeChainIsSane();
+ bool stringPrototypeChainIsSane();
+
+ void setProfileGroup(unsigned value) { createRareDataIfNeeded(); m_rareData->profileGroup = value; }
+ unsigned profileGroup() const
+ {
+ if (!m_rareData)
+ return 0;
+ return m_rareData->profileGroup;
}
- inline JSArray* constructEmptyArray(ExecState* exec)
+ Debugger* debugger() const { return m_debugger; }
+ void setDebugger(Debugger* debugger) { m_debugger = debugger; }
+
+ const GlobalObjectMethodTable* globalObjectMethodTable() const { return m_globalObjectMethodTable; }
+
+ static bool allowsAccessFrom(const JSGlobalObject*, ExecState*) { return true; }
+ static bool supportsProfiling(const JSGlobalObject*) { return false; }
+ static bool supportsRichSourceInfo(const JSGlobalObject*) { return true; }
+
+ JS_EXPORT_PRIVATE ExecState* globalExec();
+
+ static bool shouldInterruptScript(const JSGlobalObject*) { return true; }
+ static bool shouldInterruptScriptBeforeTimeout(const JSGlobalObject*) { return false; }
+ static bool javaScriptExperimentsEnabled(const JSGlobalObject*) { return false; }
+
+ void queueMicrotask(PassRefPtr<Microtask>);
+
+ bool evalEnabled() const { return m_evalEnabled; }
+ const String& evalDisabledErrorMessage() const { return m_evalDisabledErrorMessage; }
+ void setEvalEnabled(bool enabled, const String& errorMessage = String())
{
- return new (exec) JSArray(exec->lexicalGlobalObject()->arrayStructure());
+ m_evalEnabled = enabled;
+ m_evalDisabledErrorMessage = errorMessage;
}
-
- inline JSArray* constructEmptyArray(ExecState* exec, JSGlobalObject* globalObject)
+
+ void resetPrototype(VM&, JSValue prototype);
+
+ VM& vm() const { return m_vm; }
+ JSObject* globalThis() const;
+
+ static Structure* createStructure(VM& vm, JSValue prototype)
{
- return new (exec) JSArray(globalObject->arrayStructure());
+ return Structure::create(vm, 0, prototype, TypeInfo(GlobalObjectType, StructureFlags), info());
}
- inline JSArray* constructEmptyArray(ExecState* exec, unsigned initialLength)
+ void registerWeakMap(OpaqueJSWeakObjectMap* map)
{
- return new (exec) JSArray(exec->lexicalGlobalObject()->arrayStructure(), initialLength);
+ createRareDataIfNeeded();
+ m_rareData->weakMaps.add(map);
}
- inline JSArray* constructArray(ExecState* exec, JSValue singleItemValue)
+ void unregisterWeakMap(OpaqueJSWeakObjectMap* map)
{
- MarkedArgumentBuffer values;
- values.append(singleItemValue);
- return new (exec) JSArray(exec->lexicalGlobalObject()->arrayStructure(), values);
+ if (m_rareData)
+ m_rareData->weakMaps.remove(map);
}
- inline JSArray* constructArray(ExecState* exec, const ArgList& values)
+ OpaqueJSClassDataMap& opaqueJSClassData()
{
- return new (exec) JSArray(exec->lexicalGlobalObject()->arrayStructure(), values);
+ createRareDataIfNeeded();
+ return m_rareData->opaqueJSClassData;
}
- class DynamicGlobalObjectScope : public Noncopyable {
- public:
- DynamicGlobalObjectScope(CallFrame* callFrame, JSGlobalObject* dynamicGlobalObject)
- : m_dynamicGlobalObjectSlot(callFrame->globalData().dynamicGlobalObject)
- , m_savedDynamicGlobalObject(m_dynamicGlobalObjectSlot)
- {
- if (!m_dynamicGlobalObjectSlot) {
- m_dynamicGlobalObjectSlot = dynamicGlobalObject;
+ double weakRandomNumber() { return m_weakRandom.get(); }
+ unsigned weakRandomInteger() { return m_weakRandom.getUint32(); }
- // Reset the date cache between JS invocations to force the VM
- // to observe time zone changes.
- callFrame->globalData().resetDateCache();
- }
- }
+ UnlinkedProgramCodeBlock* createProgramCodeBlock(CallFrame*, ProgramExecutable*, JSObject** exception);
+ UnlinkedEvalCodeBlock* createEvalCodeBlock(CallFrame*, EvalExecutable*);
+
+protected:
+
+ static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesVisitChildren | OverridesGetPropertyNames | Base::StructureFlags;
- ~DynamicGlobalObjectScope()
+ struct GlobalPropertyInfo {
+ GlobalPropertyInfo(const Identifier& i, JSValue v, unsigned a)
+ : identifier(i)
+ , value(v)
+ , attributes(a)
{
- m_dynamicGlobalObjectSlot = m_savedDynamicGlobalObject;
}
- private:
- JSGlobalObject*& m_dynamicGlobalObjectSlot;
- JSGlobalObject* m_savedDynamicGlobalObject;
+ const Identifier identifier;
+ JSValue value;
+ unsigned attributes;
};
+ JS_EXPORT_PRIVATE void addStaticGlobals(GlobalPropertyInfo*, int count);
+
+ JS_EXPORT_PRIVATE static JSC::JSValue toThis(JSC::JSCell*, JSC::ExecState*, ECMAMode);
+
+private:
+ friend class LLIntOffsetsExtractor;
+
+ JS_EXPORT_PRIVATE void setGlobalThis(VM&, JSObject* globalThis);
+
+ // FIXME: Fold reset into init.
+ JS_EXPORT_PRIVATE void init();
+ void reset(JSValue prototype);
+
+ void createThrowTypeError(VM&);
+
+ JS_EXPORT_PRIVATE static void clearRareData(JSCell*);
+};
+
+JSGlobalObject* asGlobalObject(JSValue);
+
+inline JSGlobalObject* asGlobalObject(JSValue value)
+{
+ ASSERT(asObject(value)->isGlobalObject());
+ return jsCast<JSGlobalObject*>(asObject(value));
+}
+
+inline bool JSGlobalObject::hasOwnPropertyForWrite(ExecState* exec, PropertyName propertyName)
+{
+ PropertySlot slot(this);
+ if (Base::getOwnPropertySlot(this, exec, propertyName, slot))
+ return true;
+ bool slotIsWriteable;
+ return symbolTableGet(this, propertyName, slot, slotIsWriteable);
+}
+
+inline bool JSGlobalObject::symbolTableHasProperty(PropertyName propertyName)
+{
+ SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.uid());
+ return !entry.isNull();
+}
+
+inline JSArray* constructEmptyArray(ExecState* exec, ArrayAllocationProfile* profile, JSGlobalObject* globalObject, unsigned initialLength = 0)
+{
+ return ArrayAllocationProfile::updateLastAllocationFor(profile, JSArray::create(exec->vm(), initialLength >= MIN_SPARSE_ARRAY_INDEX ? globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithArrayStorage) : globalObject->arrayStructureForProfileDuringAllocation(profile), initialLength));
+}
+
+inline JSArray* constructEmptyArray(ExecState* exec, ArrayAllocationProfile* profile, unsigned initialLength = 0)
+{
+ return constructEmptyArray(exec, profile, exec->lexicalGlobalObject(), initialLength);
+}
+
+inline JSArray* constructArray(ExecState* exec, ArrayAllocationProfile* profile, JSGlobalObject* globalObject, const ArgList& values)
+{
+ return ArrayAllocationProfile::updateLastAllocationFor(profile, constructArray(exec, globalObject->arrayStructureForProfileDuringAllocation(profile), values));
+}
+
+inline JSArray* constructArray(ExecState* exec, ArrayAllocationProfile* profile, const ArgList& values)
+{
+ return constructArray(exec, profile, exec->lexicalGlobalObject(), values);
+}
+
+inline JSArray* constructArray(ExecState* exec, ArrayAllocationProfile* profile, JSGlobalObject* globalObject, const JSValue* values, unsigned length)
+{
+ return ArrayAllocationProfile::updateLastAllocationFor(profile, constructArray(exec, globalObject->arrayStructureForProfileDuringAllocation(profile), values, length));
+}
+
+inline JSArray* constructArray(ExecState* exec, ArrayAllocationProfile* profile, const JSValue* values, unsigned length)
+{
+ return constructArray(exec, profile, exec->lexicalGlobalObject(), values, length);
+}
+
+inline JSArray* constructArrayNegativeIndexed(ExecState* exec, ArrayAllocationProfile* profile, JSGlobalObject* globalObject, const JSValue* values, unsigned length)
+{
+ return ArrayAllocationProfile::updateLastAllocationFor(profile, constructArrayNegativeIndexed(exec, globalObject->arrayStructureForProfileDuringAllocation(profile), values, length));
+}
+
+inline JSArray* constructArrayNegativeIndexed(ExecState* exec, ArrayAllocationProfile* profile, const JSValue* values, unsigned length)
+{
+ return constructArrayNegativeIndexed(exec, profile, exec->lexicalGlobalObject(), values, length);
+}
+
+inline JSObject* JSScope::globalThis()
+{
+ return globalObject()->globalThis();
+}
+
+inline JSObject* JSGlobalObject::globalThis() const
+{
+ return m_globalThis.get();
+}
} // namespace JSC
projects / apple / javascriptcore.git / blobdiff