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** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtQml module of the Qt Toolkit.
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#ifndef DEBUGGING_H
#define DEBUGGING_H

#include "qv4global_p.h"
#include "qv4engine_p.h"
#include "qv4context_p.h"

#include <QHash>
#include <QThread>
#include <QMutex>
#include <QWaitCondition>

QT_BEGIN_NAMESPACE

namespace QV4 {

struct Function;

namespace Debugging {

class DebuggerAgent;

class Q_QML_EXPORT Debugger
{
public:
    struct VarInfo {
        enum Type {
            Invalid = 0,
            Undefined = 1,
            Null,
            Number,
            String,
            Bool,
            Object
        };

        QString name;
        QVariant value;
        Type type;

        VarInfo(): type(Invalid) {}
        VarInfo(const QString &name, const QVariant &value, Type type)
            : name(name), value(value), type(type)
        {}

        bool isValid() const { return type != Invalid; }
    };

    enum State {
        Running,
        Paused
    };

    Debugger(ExecutionEngine *engine);
    ~Debugger();

    void attachToAgent(DebuggerAgent *agent);
    void detachFromAgent();

    void pause();
    void resume();

    State state() const { return m_state; }

    void addBreakPoint(const QString &fileName, int lineNumber);
    void removeBreakPoint(const QString &fileName, int lineNumber);

    struct ExecutionState
    {
        ExecutionState() : lineNumber(-1), function(0) {}
        QString fileName;
        int lineNumber;
        Function *function;
    };

    ExecutionState currentExecutionState(const uchar *code = 0) const;

    bool pauseAtNextOpportunity() const {
        return m_pauseRequested || m_havePendingBreakPoints;
    }
    void setPendingBreakpoints(Function *function);

    QVector<StackFrame> stackTrace(int frameLimit = -1) const;
    QList<VarInfo> retrieveArgumentsFromContext(const QStringList &path, int frame = 0);
    QList<VarInfo> retrieveLocalsFromContext(const QStringList &path, int frame = 0);

public: // compile-time interface
    void maybeBreakAtInstruction(const uchar *code, bool breakPointHit);

public: // execution hooks
    void aboutToThrow(const ValueRef value);

private:
    // requires lock to be held
    void pauseAndWait();

    void applyPendingBreakPoints();

    QList<Debugger::VarInfo> retrieveFromValue(const ObjectRef o, const QStringList &path) const;
    void convert(ValueRef v, QVariant *varValue, VarInfo::Type *type) const;

    struct BreakPoints : public QHash<QString, QList<int> >
    {
        void add(const QString &fileName, int lineNumber);
        bool remove(const QString &fileName, int lineNumber);
        bool contains(const QString &fileName, int lineNumber) const;
        void applyToFunction(Function *function, bool removeBreakPoints);
    };

    QV4::ExecutionEngine *m_engine;
    DebuggerAgent *m_agent;
    QMutex m_lock;
    QWaitCondition m_runningCondition;
    State m_state;
    bool m_pauseRequested;
    bool m_havePendingBreakPoints;
    BreakPoints m_pendingBreakPointsToAdd;
    BreakPoints m_pendingBreakPointsToAddToFutureCode;
    BreakPoints m_pendingBreakPointsToRemove;
    const uchar *m_currentInstructionPointer;
};

class Q_QML_EXPORT DebuggerAgent : public QObject
{
    Q_OBJECT
public:
    ~DebuggerAgent();

    void addDebugger(Debugger *debugger);
    void removeDebugger(Debugger *debugger);

    void pause(Debugger *debugger) const;
    void pauseAll() const;
    void resumeAll() const;
    void addBreakPoint(const QString &fileName, int lineNumber) const;
    void removeBreakPoint(const QString &fileName, int lineNumber) const;

    Q_INVOKABLE virtual void debuggerPaused(QV4::Debugging::Debugger *debugger) = 0;

protected:
    QList<Debugger *> m_debuggers;
};

} // namespace Debugging
} // namespace QV4

QT_END_NAMESPACE

Q_DECLARE_METATYPE(QV4::Debugging::Debugger*)

#endif // DEBUGGING_H