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#include "jsdebuggeragent.h"

#include <QtCore/qcoreapplication.h>
#include <QtCore/qset.h>
#include <QtScript/qscriptengine.h>
#include <QtScript/QScriptContextInfo>
#include <QtCore/QDebug>
#include <QtCore/QUrl>

QT_BEGIN_NAMESPACE

/*!
  Constructs a new agent for the given \a engine. The agent will
  report debugging-related events (e.g. step completion) to the given
  \a backend.
*/
JSDebuggerAgent::JSDebuggerAgent(QScriptEngine *engine)
    : QDeclarativeDebugService("JSDebugger"), QScriptEngineAgent(engine)
{}

/*!
  Destroys this QScriptDebuggerAgent.
*/
JSDebuggerAgent::~JSDebuggerAgent()
{}

/*!
  \reimp
*/
void JSDebuggerAgent::scriptLoad(qint64 id, const QString & program,
                                      const QString &fileName, int )
{
    Q_UNUSED(program);
    filenames.insert(id, QUrl(fileName).toLocalFile());
}

/*!
  \reimp
*/
void JSDebuggerAgent::scriptUnload(qint64 id)
{
    filenames.remove(id);
}

/*!
  \reimp
*/
void JSDebuggerAgent::contextPush()
{
}

/*!
  \reimp
*/
void JSDebuggerAgent::contextPop()
{
}

/*!
  \reimp
*/
void JSDebuggerAgent::functionEntry(qint64 scriptId)
{
    Q_UNUSED(scriptId);
    stepDepth++;
}

/*!
  \reimp
*/
void JSDebuggerAgent::functionExit(qint64 scriptId, const QScriptValue &returnValue)
{
    Q_UNUSED(scriptId);
    Q_UNUSED(returnValue);
    stepDepth--;
}

/*!
  \reimp
*/
void JSDebuggerAgent::positionChange(qint64 scriptId,
                                   int lineNumber, int columnNumber)
{
    Q_UNUSED(columnNumber);

    if(state == Stopped)
        return; //no re-entrency

    // check breakpoints
    if (!breakpointList.isEmpty()) {
        QHash<qint64, QString>::const_iterator it = filenames.constFind(scriptId);
        if (it == filenames.constEnd()) {
            // It is possible that the scripts are loaded before the agent is attached
            QString filename = QUrl(QScriptContextInfo(engine()->currentContext()).fileName()).toLocalFile();
            QPair<QString, qint32> key = qMakePair(filename, lineNumber);
            it = filenames.insert(scriptId, filename);
        }
        QPair<QString, qint32> key = qMakePair(*it, lineNumber);
        if (breakpointList.contains(key)) {
            stopped();
            return;
        }
    }


    switch (state) {
    case NoState:
    case Stopped:
        // Do nothing
        break;

    case SteppingOutState:
        if (stepDepth >= 0)
            break;
        //fallthough
    case SteppingOverState:
        if (stepDepth > 0)
            break;
        //fallthough
    case SteppingIntoState:
        stopped();
        break;
    }

}

/*!
  \reimp
*/
void JSDebuggerAgent::exceptionThrow(qint64 scriptId,
                                   const QScriptValue &exception,
                                   bool hasHandler)
{
    Q_UNUSED(scriptId);
    Q_UNUSED(exception);
    Q_UNUSED(hasHandler);
/* ... */
}

/*!
  \reimp
*/
void JSDebuggerAgent::exceptionCatch(qint64 scriptId,
                                          const QScriptValue &exception)
{
    Q_UNUSED(scriptId);
    Q_UNUSED(exception);
}

void JSDebuggerAgent::messageReceived(const QByteArray& message)
{
    QDataStream ds(message);
    QByteArray command;
    ds >> command;
    if (command == "BREAKPOINTS") {
        ds >> breakpointList;
    } else if (command == "WATCH_EXPRESSIONS") {
        ds >> watchExpressions;
    } else if (command == "STEPOVER") {
        stepDepth = 0;
        state = SteppingOverState;
        continueExec();
    } else if (command == "STEPINTO" || command == "INTERRUPT") {
        stepDepth = 0;
        state = SteppingIntoState;
        continueExec();
    } else if (command == "STEPOUT") {
        stepDepth = 0;
        state = SteppingOutState;
        continueExec();
    } else if (command == "CONTINUE") {
        state = NoState;
        continueExec();
    } else if (command == "EXEC") {
        State oldState = state;
        state = Stopped;
        QByteArray id;
        QString expr;
        ds >> id >> expr;

        QVariant val = engine()->evaluate(expr).toVariant();
        // Clear any exceptions occurred during locals evaluation.
        engine()->clearExceptions();

        QByteArray reply;
        QDataStream rs(&reply, QIODevice::WriteOnly);
        rs << QByteArray("RESULT") << id << expr << val;
        sendMessage(reply);
        state = oldState;

    } else {
        qDebug() << Q_FUNC_INFO << "Unknown command" << command;
    }

    QDeclarativeDebugService::messageReceived(message);
}

void JSDebuggerAgent::stopped()
{
    state = Stopped;
    QList<QPair<QString, QPair<QString, qint32> > > backtrace;

    for (QScriptContext* ctx = engine()->currentContext(); ctx; ctx = ctx->parentContext()) {
        QScriptContextInfo info(ctx);

        QString functionName = info.functionName();
        if (functionName.isEmpty()) {
            if (ctx->parentContext()) {
                switch (info.functionType()) {
                case QScriptContextInfo::ScriptFunction:
                    functionName = QLatin1String("<anonymous>");
                    break;
                case QScriptContextInfo::NativeFunction:
                    functionName = QLatin1String("<native>");
                    break;
                case QScriptContextInfo::QtFunction:
                case QScriptContextInfo::QtPropertyFunction:
                    functionName = QLatin1String("<native slot>");
                    break;
                }
            } else {
                functionName = QLatin1String("<global>");
            }
        }
        backtrace.append(qMakePair(functionName, qMakePair( QUrl(info.fileName()).toLocalFile(), info.lineNumber() ) ) );
    }
    QList<QPair<QString, QVariant> > watches;
    foreach (const QString &expr, watchExpressions) {
        watches << qMakePair(expr,  engine()->evaluate(expr).toVariant());
    }

    // Clear any exceptions occurred during locals evaluation.
    engine()->clearExceptions();


    QByteArray reply;
    QDataStream rs(&reply, QIODevice::WriteOnly);
    rs << QByteArray("STOPPED") << backtrace << watches;
    sendMessage(reply);

    loop.exec(QEventLoop::ExcludeUserInputEvents);
}

void JSDebuggerAgent::continueExec()
{
    loop.quit();
}

void JSDebuggerAgent::enabledChanged(bool on)
{
    engine()->setAgent(on ? this : 0);
    QDeclarativeDebugService::enabledChanged(on);
}

QT_END_NAMESPACE