qscriptcontextinfo.cpp

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/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtScript module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL-ONLY$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** If you have questions regarding the use of this file, please contact
** us via http://www.qt-project.org/.
**
** $QT_END_LICENSE$
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****************************************************************************/

#include "config.h"
#include "qscriptcontextinfo.h"

#include "qscriptcontext_p.h"
#include "qscriptengine.h"
#include "qscriptengine_p.h"
#include "../bridge/qscriptqobject_p.h"
#include <QtCore/qdatastream.h>
#include <QtCore/qmetaobject.h>
#include "CodeBlock.h"
#include "JSFunction.h"
#if ENABLE(JIT)
#include "MacroAssemblerCodeRef.h"
#endif

QT_BEGIN_NAMESPACE

class QScriptContextInfoPrivate
{
    Q_DECLARE_PUBLIC(QScriptContextInfo)
public:
    QScriptContextInfoPrivate();
    QScriptContextInfoPrivate(const QScriptContext *context);
    ~QScriptContextInfoPrivate();

    qint64 scriptId;
    int lineNumber;
    int columnNumber;
    QString fileName;

    QString functionName;
    QScriptContextInfo::FunctionType functionType;

    int functionStartLineNumber;
    int functionEndLineNumber;
    int functionMetaIndex;

    QStringList parameterNames;

    QBasicAtomicInt ref;

    QScriptContextInfo *q_ptr;
};

QScriptContextInfoPrivate::QScriptContextInfoPrivate()
{
    ref = 0;
    functionType = QScriptContextInfo::NativeFunction;
    functionMetaIndex = -1;
    functionStartLineNumber = -1;
    functionEndLineNumber = -1;
    scriptId = -1;
    lineNumber = -1;
    columnNumber = -1;
}

QScriptContextInfoPrivate::QScriptContextInfoPrivate(const QScriptContext *context)
{
    Q_ASSERT(context);
    ref = 0;
    functionType = QScriptContextInfo::NativeFunction;
    functionMetaIndex = -1;
    functionStartLineNumber = -1;
    functionEndLineNumber = -1;
    scriptId = -1;
    lineNumber = -1;
    columnNumber = -1;

    JSC::CallFrame *frame = const_cast<JSC::CallFrame *>(QScriptEnginePrivate::frameForContext(context));

    // Get the line number:

    //We need to know the context directly up in the backtrace, in order to get the line number, and adjust the global context
    JSC::CallFrame *rewindContext = QScriptEnginePrivate::get(context->engine())->currentFrame;
    if (QScriptEnginePrivate::contextForFrame(rewindContext) == context) {  //top context
        frame = rewindContext; //for retreiving the global context's "fake" frame
        // An agent might have provided the line number.
        lineNumber = QScript::scriptEngineFromExec(frame)->agentLineNumber;
    } else {
        // rewind the stack from the top in order to find the frame from the caller where the returnPC is stored
        while (rewindContext && QScriptEnginePrivate::contextForFrame(rewindContext->callerFrame()->removeHostCallFrameFlag()) != context)
            rewindContext = rewindContext->callerFrame()->removeHostCallFrameFlag();
        if (rewindContext) {
            frame = rewindContext->callerFrame()->removeHostCallFrameFlag(); //for retreiving the global context's "fake" frame

            JSC::Instruction *returnPC = rewindContext->returnPC();
            JSC::CodeBlock *codeBlock = frame->codeBlock();
            if (returnPC && codeBlock && QScriptEnginePrivate::hasValidCodeBlockRegister(frame)) {
#if ENABLE(JIT)
                JSC::JITCode code = codeBlock->getJITCode();
                uintptr_t jitOffset = reinterpret_cast<uintptr_t>(JSC::ReturnAddressPtr(returnPC).value()) - reinterpret_cast<uintptr_t>(code.addressForCall().executableAddress());
                // We can only use the JIT code offset if it's smaller than the JIT size;
                // otherwise calling getBytecodeIndex() is meaningless.
                if (jitOffset < code.size()) {
                    unsigned bytecodeOffset = codeBlock->getBytecodeIndex(frame, JSC::ReturnAddressPtr(returnPC));
#else
                unsigned bytecodeOffset = returnPC - codeBlock->instructions().begin();
#endif
                bytecodeOffset--; //because returnPC is on the next instruction. We want the current one
                lineNumber = codeBlock->lineNumberForBytecodeOffset(const_cast<JSC::ExecState *>(frame), bytecodeOffset);
#if ENABLE(JIT)
                }
#endif
            }
        }
    }

    // Get the filename and the scriptId:
    JSC::CodeBlock *codeBlock = frame->codeBlock();
    if (codeBlock && QScriptEnginePrivate::hasValidCodeBlockRegister(frame)) {
           JSC::SourceProvider *source = codeBlock->source();
           scriptId = source->asID();
           fileName = source->url();
    }

    // Get the others information:
    JSC::JSObject *callee = frame->callee();
    if (callee && callee->inherits(&JSC::InternalFunction::info))
        functionName = JSC::asInternalFunction(callee)->name(frame);
    if (callee && callee->inherits(&JSC::JSFunction::info)
        && !JSC::asFunction(callee)->isHostFunction()) {
        functionType = QScriptContextInfo::ScriptFunction;
        JSC::FunctionExecutable *body = JSC::asFunction(callee)->jsExecutable();
        functionStartLineNumber = body->lineNo();
        functionEndLineNumber = body->lastLine();
        for (size_t i = 0; i < body->parameterCount(); ++i)
            parameterNames.append(body->parameterName(i));
        // ### get the function name from the AST
    } else if (callee && callee->inherits(&QScript::QtFunction::info)) {
        functionType = QScriptContextInfo::QtFunction;
        // ### the slot can be overloaded -- need to get the particular overload from the context
        functionMetaIndex = static_cast<QScript::QtFunction*>(callee)->initialIndex();
        const QMetaObject *meta = static_cast<QScript::QtFunction*>(callee)->metaObject();
        if (meta != 0) {
            QMetaMethod method = meta->method(functionMetaIndex);
            QList<QByteArray> formals = method.parameterNames();
            for (int i = 0; i < formals.count(); ++i)
                parameterNames.append(QLatin1String(formals.at(i)));
        }
    }
    else if (callee && callee->inherits(&QScript::QtPropertyFunction::info)) {
        functionType = QScriptContextInfo::QtPropertyFunction;
        functionMetaIndex = static_cast<QScript::QtPropertyFunction*>(callee)->propertyIndex();
    }
}

QScriptContextInfoPrivate::~QScriptContextInfoPrivate()
{
}

QScriptContextInfo::QScriptContextInfo(const QScriptContext *context)
    : d_ptr(0)
{
    if (context) {
        d_ptr = new QScriptContextInfoPrivate(context);
        d_ptr->q_ptr = this;
    }
}

QScriptContextInfo::QScriptContextInfo(const QScriptContextInfo &other)
    : d_ptr(other.d_ptr)
{
}

QScriptContextInfo::QScriptContextInfo()
    : d_ptr(0)
{
}

QScriptContextInfo::~QScriptContextInfo()
{
}

QScriptContextInfo &QScriptContextInfo::operator=(const QScriptContextInfo &other)
{
    d_ptr = other.d_ptr;
    return *this;
}

qint64 QScriptContextInfo::scriptId() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->scriptId;
}

QString QScriptContextInfo::fileName() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return QString();
    return d->fileName;
}

int QScriptContextInfo::lineNumber() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->lineNumber;
}

int QScriptContextInfo::columnNumber() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->columnNumber;
}

QString QScriptContextInfo::functionName() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return QString();
    return d->functionName;
}

QScriptContextInfo::FunctionType QScriptContextInfo::functionType() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return NativeFunction;
    return d->functionType;
}

int QScriptContextInfo::functionStartLineNumber() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->functionStartLineNumber;
}

int QScriptContextInfo::functionEndLineNumber() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->functionEndLineNumber;
}

QStringList QScriptContextInfo::functionParameterNames() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return QStringList();
    return d->parameterNames;
}

int QScriptContextInfo::functionMetaIndex() const
{
    Q_D(const QScriptContextInfo);
    if (!d)
        return -1;
    return d->functionMetaIndex;
}

bool QScriptContextInfo::isNull() const
{
    Q_D(const QScriptContextInfo);
    return (d == 0);
}

bool QScriptContextInfo::operator==(const QScriptContextInfo &other) const
{
    Q_D(const QScriptContextInfo);
    const QScriptContextInfoPrivate *od = other.d_func();
    if (d == od)
        return true;
    if (!d || !od)
        return false;
    return ((d->scriptId == od->scriptId)
            && (d->lineNumber == od->lineNumber)
            && (d->columnNumber == od->columnNumber)
            && (d->fileName == od->fileName)
            && (d->functionName == od->functionName)
            && (d->functionType == od->functionType)
            && (d->functionStartLineNumber == od->functionStartLineNumber)
            && (d->functionEndLineNumber == od->functionEndLineNumber)
            && (d->functionMetaIndex == od->functionMetaIndex)
            && (d->parameterNames == od->parameterNames));
}

bool QScriptContextInfo::operator!=(const QScriptContextInfo &other) const
{
    return !(*this == other);
}

#ifndef QT_NO_DATASTREAM

QDataStream &operator<<(QDataStream &out, const QScriptContextInfo &info)
{
    out << info.scriptId();
    out << (qint32)info.lineNumber();
    out << (qint32)info.columnNumber();

    out << (quint32)info.functionType();
    out << (qint32)info.functionStartLineNumber();
    out << (qint32)info.functionEndLineNumber();
    out << (qint32)info.functionMetaIndex();

    out << info.fileName();
    out << info.functionName();
    out << info.functionParameterNames();

    return out;
}

Q_SCRIPT_EXPORT QDataStream &operator>>(QDataStream &in, QScriptContextInfo &info)
{
    if (!info.d_ptr) {
        info.d_ptr = new QScriptContextInfoPrivate();
    }

    in >> info.d_ptr->scriptId;

    qint32 line;
    in >> line;
    info.d_ptr->lineNumber = line;

    qint32 column;
    in >> column;
    info.d_ptr->columnNumber = column;

    quint32 ftype;
    in >> ftype;
    info.d_ptr->functionType = QScriptContextInfo::FunctionType(ftype);

    qint32 startLine;
    in >> startLine;
    info.d_ptr->functionStartLineNumber = startLine;

    qint32 endLine;
    in >> endLine;
    info.d_ptr->functionEndLineNumber = endLine;

    qint32 metaIndex;
    in >> metaIndex;
    info.d_ptr->functionMetaIndex = metaIndex;

    in >> info.d_ptr->fileName;
    in >> info.d_ptr->functionName;
    in >> info.d_ptr->parameterNames;

    return in;
}
#endif

QT_END_NAMESPACE