qtdeclarative/src/qml/jsruntime/qv4engine_p.h

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**
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**
** $QT_BEGIN_LICENSE:LGPL21$
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** accordance with the commercial license agreement provided with the
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** Alternatively, this file may be used under the terms of the GNU Lesser
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#ifndef QV4ENGINE_H
#define QV4ENGINE_H

#include "qv4global_p.h"
#include "private/qv4isel_p.h"
#include "qv4managed_p.h"
#include "qv4context_p.h"
#include "qv4internalclass_p.h"
#include <private/qintrusivelist_p.h>

namespace WTF {
class BumpPointerAllocator;
class PageAllocation;
}

QT_BEGIN_NAMESPACE

class QV8Engine;
class QQmlError;
class QJSEngine;
class QQmlEngine;
class QQmlContextData;

namespace QV4 {
namespace Debugging {
class Debugger;
} // namespace Debugging
namespace Profiling {
class Profiler;
} // namespace Profiling
namespace CompiledData {
struct CompilationUnit;
}

#define CHECK_STACK_LIMITS(v4) \
    if ((v4->jsStackTop <= v4->jsStackLimit) && (reinterpret_cast<quintptr>(&v4) >= v4->cStackLimit || v4->recheckCStackLimits())) {}  \
    else \
        return v4->throwRangeError(QStringLiteral("Maximum call stack size exceeded."))


struct Q_QML_EXPORT ExecutionEngine
{
private:
    friend struct ExecutionContextSaver;
    friend struct ExecutionContext;
    friend struct Heap::ExecutionContext;
public:
    Heap::ExecutionContext *current;

    Value *jsStackTop;
    quint32 hasException;

    MemoryManager *memoryManager;
    ExecutableAllocator *executableAllocator;
    ExecutableAllocator *regExpAllocator;
    QScopedPointer<EvalISelFactory> iselFactory;

    ExecutionContext *currentContext;

    Value *jsStackLimit;
    quintptr cStackLimit;

    WTF::BumpPointerAllocator *bumperPointerAllocator; // Used by Yarr Regex engine.

    enum { JSStackLimit = 4*1024*1024 };
    WTF::PageAllocation *jsStack;
    Value *jsStackBase;

    void pushForGC(Heap::Base *m) {
        *jsStackTop = m;
        ++jsStackTop;
    }
    Heap::Base *popForGC() {
        --jsStackTop;
        return jsStackTop->heapObject();
    }
    Value *jsAlloca(int nValues) {
        Value *ptr = jsStackTop;
        jsStackTop = ptr + nValues;
        memset(ptr, 0, nValues*sizeof(Value));
        return ptr;
    }

    IdentifierTable *identifierTable;

    QV4::Debugging::Debugger *debugger;
    QV4::Profiling::Profiler *profiler;

    Object *globalObject;

    Function *globalCode;

    QJSEngine *jsEngine() const;
    QQmlEngine *qmlEngine() const;
    QV8Engine *v8Engine;

    enum JSObjects {
        RootContext,
        IntegerNull, // Has to come after the RootContext to make the context stack safe
        ObjectProto,
        ArrayProto,
        StringProto,
        NumberProto,
        BooleanProto,
        DateProto,
        FunctionProto,
        RegExpProto,
        ErrorProto,
        EvalErrorProto,
        RangeErrorProto,
        ReferenceErrorProto,
        SyntaxErrorProto,
        TypeErrorProto,
        URIErrorProto,
        VariantProto,
        SequenceProto,
        ArrayBufferProto,
        DataViewProto,
        ValueTypeProto,

        Object_Ctor,
        String_Ctor,
        Number_Ctor,
        Boolean_Ctor,
        Array_Ctor,
        Function_Ctor,
        Date_Ctor,
        RegExp_Ctor,
        Error_Ctor,
        EvalError_Ctor,
        RangeError_Ctor,
        ReferenceError_Ctor,
        SyntaxError_Ctor,
        TypeError_Ctor,
        URIError_Ctor,
        ArrayBuffer_Ctor,
        DataView_Ctor,

        Eval_Function,
        ThrowerObject,
        NJSObjects
    };
    Value *jsObjects;
    enum { NTypedArrayTypes = 9 }; // == TypedArray::NValues, avoid header dependency

    GlobalContext *rootContext() const { return reinterpret_cast<GlobalContext *>(jsObjects + RootContext); }
    FunctionObject *objectCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Object_Ctor); }
    FunctionObject *stringCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + String_Ctor); }
    FunctionObject *numberCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Number_Ctor); }
    FunctionObject *booleanCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Boolean_Ctor); }
    FunctionObject *arrayCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Array_Ctor); }
    FunctionObject *functionCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Function_Ctor); }
    FunctionObject *dateCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Date_Ctor); }
    FunctionObject *regExpCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + RegExp_Ctor); }
    FunctionObject *errorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Error_Ctor); }
    FunctionObject *evalErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + EvalError_Ctor); }
    FunctionObject *rangeErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + RangeError_Ctor); }
    FunctionObject *referenceErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + ReferenceError_Ctor); }
    FunctionObject *syntaxErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + SyntaxError_Ctor); }
    FunctionObject *typeErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + TypeError_Ctor); }
    FunctionObject *uRIErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + URIError_Ctor); }
    FunctionObject *arrayBufferCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + ArrayBuffer_Ctor); }
    FunctionObject *dataViewCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + DataView_Ctor); }
    FunctionObject *typedArrayCtors;

    Object *objectPrototype() const { return reinterpret_cast<Object *>(jsObjects + ObjectProto); }
    Object *arrayPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayProto); }
    Object *stringPrototype() const { return reinterpret_cast<Object *>(jsObjects + StringProto); }
    Object *numberPrototype() const { return reinterpret_cast<Object *>(jsObjects + NumberProto); }
    Object *booleanPrototype() const { return reinterpret_cast<Object *>(jsObjects + BooleanProto); }
    Object *datePrototype() const { return reinterpret_cast<Object *>(jsObjects + DateProto); }
    Object *functionPrototype() const { return reinterpret_cast<Object *>(jsObjects + FunctionProto); }
    Object *regExpPrototype() const { return reinterpret_cast<Object *>(jsObjects + RegExpProto); }
    Object *errorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ErrorProto); }
    Object *evalErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + EvalErrorProto); }
    Object *rangeErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + RangeErrorProto); }
    Object *referenceErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ReferenceErrorProto); }
    Object *syntaxErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + SyntaxErrorProto); }
    Object *typeErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + TypeErrorProto); }
    Object *uRIErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + URIErrorProto); }
    Object *variantPrototype() const { return reinterpret_cast<Object *>(jsObjects + VariantProto); }
    Object *sequencePrototype() const { return reinterpret_cast<Object *>(jsObjects + SequenceProto); }

    Object *arrayBufferPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayBufferProto); }
    Object *dataViewPrototype() const { return reinterpret_cast<Object *>(jsObjects + DataViewProto); }
    Object *typedArrayPrototype;

    Object *valueTypeWrapperPrototype() const { return reinterpret_cast<Object *>(jsObjects + ValueTypeProto); }

    InternalClassPool *classPool;
    InternalClass *emptyClass;

    InternalClass *arrayClass;
    InternalClass *stringClass;

    InternalClass *functionClass;
    InternalClass *simpleScriptFunctionClass;
    InternalClass *protoClass;

    InternalClass *regExpExecArrayClass;

    InternalClass *argumentsObjectClass;
    InternalClass *strictArgumentsObjectClass;

    EvalFunction *evalFunction() const { return reinterpret_cast<EvalFunction *>(jsObjects + Eval_Function); }
    FunctionObject *thrower() const { return reinterpret_cast<FunctionObject *>(jsObjects + ThrowerObject); }

    Property *argumentsAccessors;
    int nArgumentsAccessors;

    enum JSStrings {
        String_Empty,
        String_undefined,
        String_null,
        String_true,
        String_false,
        String_boolean,
        String_number,
        String_string,
        String_object,
        String_function,
        String_length,
        String_prototype,
        String_constructor,
        String_arguments,
        String_caller,
        String_callee,
        String_this,
        String___proto__,
        String_enumerable,
        String_configurable,
        String_writable,
        String_value,
        String_get,
        String_set,
        String_eval,
        String_uintMax,
        String_name,
        String_index,
        String_input,
        String_toString,
        String_destroy,
        String_valueOf,
        String_byteLength,
        String_byteOffset,
        String_buffer,
        String_lastIndex,
        NJSStrings
    };
    Value *jsStrings;

    String *id_empty() const { return reinterpret_cast<String *>(jsStrings + String_Empty); }
    String *id_undefined() const { return reinterpret_cast<String *>(jsStrings + String_undefined); }
    String *id_null() const { return reinterpret_cast<String *>(jsStrings + String_null); }
    String *id_true() const { return reinterpret_cast<String *>(jsStrings + String_true); }
    String *id_false() const { return reinterpret_cast<String *>(jsStrings + String_false); }
    String *id_boolean() const { return reinterpret_cast<String *>(jsStrings + String_boolean); }
    String *id_number() const { return reinterpret_cast<String *>(jsStrings + String_number); }
    String *id_string() const { return reinterpret_cast<String *>(jsStrings + String_string); }
    String *id_object() const { return reinterpret_cast<String *>(jsStrings + String_object); }
    String *id_function() const { return reinterpret_cast<String *>(jsStrings + String_function); }
    String *id_length() const { return reinterpret_cast<String *>(jsStrings + String_length); }
    String *id_prototype() const { return reinterpret_cast<String *>(jsStrings + String_prototype); }
    String *id_constructor() const { return reinterpret_cast<String *>(jsStrings + String_constructor); }
    String *id_arguments() const { return reinterpret_cast<String *>(jsStrings + String_arguments); }
    String *id_caller() const { return reinterpret_cast<String *>(jsStrings + String_caller); }
    String *id_callee() const { return reinterpret_cast<String *>(jsStrings + String_callee); }
    String *id_this() const { return reinterpret_cast<String *>(jsStrings + String_this); }
    String *id___proto__() const { return reinterpret_cast<String *>(jsStrings + String___proto__); }
    String *id_enumerable() const { return reinterpret_cast<String *>(jsStrings + String_enumerable); }
    String *id_configurable() const { return reinterpret_cast<String *>(jsStrings + String_configurable); }
    String *id_writable() const { return reinterpret_cast<String *>(jsStrings + String_writable); }
    String *id_value() const { return reinterpret_cast<String *>(jsStrings + String_value); }
    String *id_get() const { return reinterpret_cast<String *>(jsStrings + String_get); }
    String *id_set() const { return reinterpret_cast<String *>(jsStrings + String_set); }
    String *id_eval() const { return reinterpret_cast<String *>(jsStrings + String_eval); }
    String *id_uintMax() const { return reinterpret_cast<String *>(jsStrings + String_uintMax); }
    String *id_name() const { return reinterpret_cast<String *>(jsStrings + String_name); }
    String *id_index() const { return reinterpret_cast<String *>(jsStrings + String_index); }
    String *id_input() const { return reinterpret_cast<String *>(jsStrings + String_input); }
    String *id_toString() const { return reinterpret_cast<String *>(jsStrings + String_toString); }
    String *id_destroy() const { return reinterpret_cast<String *>(jsStrings + String_destroy); }
    String *id_valueOf() const { return reinterpret_cast<String *>(jsStrings + String_valueOf); }
    String *id_byteLength() const { return reinterpret_cast<String *>(jsStrings + String_byteLength); }
    String *id_byteOffset() const { return reinterpret_cast<String *>(jsStrings + String_byteOffset); }
    String *id_buffer() const { return reinterpret_cast<String *>(jsStrings + String_buffer); }
    String *id_lastIndex() const { return reinterpret_cast<String *>(jsStrings + String_lastIndex); }

    QSet<CompiledData::CompilationUnit*> compilationUnits;

    quint32 m_engineId;

    RegExpCache *regExpCache;

    // Scarce resources are "exceptionally high cost" QVariant types where allowing the
    // normal JavaScript GC to clean them up is likely to lead to out-of-memory or other
    // out-of-resource situations.  When such a resource is passed into JavaScript we
    // add it to the scarceResources list and it is destroyed when we return from the
    // JavaScript execution that created it.  The user can prevent this behavior by
    // calling preserve() on the object which removes it from this scarceResource list.
    class ScarceResourceData {
    public:
        ScarceResourceData(const QVariant &data = QVariant()) : data(data) {}
        QVariant data;
        QIntrusiveListNode node;
    };
    QIntrusiveList<ScarceResourceData, &ScarceResourceData::node> scarceResources;

    // Normally the JS wrappers for QObjects are stored in the QQmlData/QObjectPrivate,
    // but any time a QObject is wrapped a second time in another engine, we have to do
    // bookkeeping.
    MultiplyWrappedQObjectMap *m_multiplyWrappedQObjects;

    ExecutionEngine(EvalISelFactory *iselFactory = 0);
    ~ExecutionEngine();

    void enableDebugger();
    void enableProfiler();

    ExecutionContext *pushGlobalContext();
    void pushContext(Heap::ExecutionContext *context);
    void pushContext(ExecutionContext *context);
    void popContext();
    ExecutionContext *parentContext(ExecutionContext *context) const;

    Heap::Object *newObject();
    Heap::Object *newObject(InternalClass *internalClass, Object *prototype);

    Heap::String *newString(const QString &s = QString());
    Heap::String *newIdentifier(const QString &text);

    Heap::Object *newStringObject(const String *string);
    Heap::Object *newNumberObject(double value);
    Heap::Object *newBooleanObject(bool b);

    Heap::ArrayObject *newArrayObject(int count = 0);
    Heap::ArrayObject *newArrayObject(const QStringList &list);
    Heap::ArrayObject *newArrayObject(InternalClass *ic, Object *prototype);

    Heap::ArrayBuffer *newArrayBuffer(const QByteArray &array);
    Heap::ArrayBuffer *newArrayBuffer(size_t length);

    Heap::DateObject *newDateObject(const Value &value);
    Heap::DateObject *newDateObject(const QDateTime &dt);

    Heap::RegExpObject *newRegExpObject(const QString &pattern, int flags);
    Heap::RegExpObject *newRegExpObject(RegExp *re, bool global);
    Heap::RegExpObject *newRegExpObject(const QRegExp &re);

    Heap::Object *newErrorObject(const Value &value);
    Heap::Object *newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column);
    Heap::Object *newSyntaxErrorObject(const QString &message);
    Heap::Object *newReferenceErrorObject(const QString &message);
    Heap::Object *newReferenceErrorObject(const QString &message, const QString &fileName, int lineNumber, int columnNumber);
    Heap::Object *newTypeErrorObject(const QString &message);
    Heap::Object *newRangeErrorObject(const QString &message);
    Heap::Object *newURIErrorObject(const Value &message);

    Heap::Object *newVariantObject(const QVariant &v);

    Heap::Object *newForEachIteratorObject(Object *o);

    Heap::QmlContext *qmlContext() const;
    QObject *qmlScopeObject() const;
    ReturnedValue qmlSingletonWrapper(String *name);
    QQmlContextData *callingQmlContext() const;


    StackTrace stackTrace(int frameLimit = -1) const;
    StackFrame currentStackFrame() const;
    QUrl resolvedUrl(const QString &file);

    void requireArgumentsAccessors(int n);

    void markObjects();

    void initRootContext();

    InternalClass *newClass(const InternalClass &other);

    bool recheckCStackLimits();

    // Exception handling
    Value *exceptionValue;
    StackTrace exceptionStackTrace;

    ReturnedValue throwError(const Value &value);
    ReturnedValue catchException(StackTrace *trace = 0);

    ReturnedValue throwError(const QString &message);
    ReturnedValue throwSyntaxError(const QString &message);
    ReturnedValue throwSyntaxError(const QString &message, const QString &fileName, int lineNumber, int column);
    ReturnedValue throwTypeError();
    ReturnedValue throwTypeError(const QString &message);
    ReturnedValue throwReferenceError(const Value &value);
    ReturnedValue throwReferenceError(const QString &value, const QString &fileName, int lineNumber, int column);
    ReturnedValue throwRangeError(const Value &value);
    ReturnedValue throwRangeError(const QString &message);
    ReturnedValue throwURIError(const Value &msg);
    ReturnedValue throwUnimplemented(const QString &message);

    // Use only inside catch(...) -- will re-throw if no JS exception
    QQmlError catchExceptionAsQmlError();

    // variant conversions
    QVariant toVariant(const QV4::Value &value, int typeHint, bool createJSValueForObjects = true);
    QV4::ReturnedValue fromVariant(const QVariant &);

    QVariantMap variantMapFromJS(const QV4::Object *o);

    bool metaTypeFromJS(const Value *value, int type, void *data);
    QV4::ReturnedValue metaTypeToJS(int type, const void *data);

    void assertObjectBelongsToEngine(const Heap::Base &baseObject);
};

inline void ExecutionEngine::pushContext(Heap::ExecutionContext *context)
{
    Q_ASSERT(currentContext && context);
    Value *v = jsAlloca(2);
    v[0] = Encode(context);
    v[1] = Encode((int)(v - static_cast<Value *>(currentContext)));
    currentContext = static_cast<ExecutionContext *>(v);
    current = currentContext->d();
}

inline void ExecutionEngine::pushContext(ExecutionContext *context)
{
    pushContext(context->d());
}


inline void ExecutionEngine::popContext()
{
    Q_ASSERT(jsStackTop > currentContext);
    QV4::Value *offset = (currentContext + 1);
    Q_ASSERT(offset->isInteger());
    int o = offset->integerValue();
    Q_ASSERT(o);
    currentContext -= o;
    current = currentContext->d();
}

inline
void Heap::Base::mark(QV4::ExecutionEngine *engine)
{
    Q_ASSERT(inUse());
    if (isMarked())
        return;
#ifndef QT_NO_DEBUG
    engine->assertObjectBelongsToEngine(*this);
#endif
    setMarkBit();
    engine->pushForGC(this);
}

inline void Value::mark(ExecutionEngine *e)
{
    if (!_val)
        return;
    Managed *m = as<Managed>();
    if (m)
        m->d()->mark(e);
}



} // namespace QV4

QT_END_NAMESPACE

#endif // QV4ENGINE_H