/****************************************************************************
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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the V4VM module of the Qt Toolkit.
**
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** ensure the GNU Lesser General Public License version 2.1 requirements
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** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
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****************************************************************************/

#ifndef DEBUGGING_H
#define DEBUGGING_H

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

#include <QHash>

QT_BEGIN_NAMESPACE

namespace QQmlJS {

namespace V4IR {
struct BasicBlock;
struct Function;
} // namespace IR

namespace Debugging {

class Debugger;

struct FunctionDebugInfo { // TODO: use opaque d-pointers here
    QString name;
    unsigned startLine, startColumn;

    FunctionDebugInfo(V4IR::Function *function):
        startLine(0), startColumn(0)
    {
        if (function->name)
            name = *function->name;
    }

    void setSourceLocation(unsigned line, unsigned column)
    { startLine = line; startColumn = column; }
};

class FunctionState
{
public:
    FunctionState(VM::ExecutionContext *context);
    virtual ~FunctionState();

    virtual VM::Value *argument(unsigned idx);
    virtual VM::Value *local(unsigned idx);
    virtual VM::Value *temp(unsigned idx) = 0;

    VM::ExecutionContext *context() const
    { return _context; }

    Debugger *debugger() const
    { return _context->engine->debugger; }

private:
    VM::ExecutionContext *_context;
};

struct CallInfo
{
    VM::ExecutionContext *context;
    VM::FunctionObject *function;
    FunctionState *state;

    CallInfo(VM::ExecutionContext *context = 0, VM::FunctionObject *function = 0, FunctionState *state = 0)
        : context(context)
        , function(function)
        , state(state)
    {}
};

class Q_V4_EXPORT Debugger
{
public:
    Debugger(VM::ExecutionEngine *_engine);
    ~Debugger();

public: // compile-time interface
    void addFunction(V4IR::Function *function);
    void setSourceLocation(V4IR::Function *function, unsigned line, unsigned column);
    void mapFunction(VM::Function *vmf, V4IR::Function *irf);

public: // run-time querying interface
    FunctionDebugInfo *debugInfo(VM::FunctionObject *function) const;
    QString name(VM::FunctionObject *function) const;

public: // execution hooks
    void aboutToCall(VM::FunctionObject *function, VM::ExecutionContext *context);
    void justLeft(VM::ExecutionContext *context);
    void enterFunction(FunctionState *state);
    void leaveFunction(FunctionState *state);
    void aboutToThrow(const VM::Value &value);

public: // debugging hooks
    FunctionState *currentState() const;
    const char *currentArg(unsigned idx) const;
    const char *currentLocal(unsigned idx) const;
    const char *currentTemp(unsigned idx) const;
    void printStackTrace() const;

private:
    int callIndex(VM::ExecutionContext *context);
    V4IR::Function *irFunction(VM::Function *vmf) const;

private: // TODO: use opaque d-pointers here
    VM::ExecutionEngine *_engine;
    QHash<V4IR::Function *, FunctionDebugInfo *> _functionInfo;
    QHash<VM::Function *, V4IR::Function *> _vmToIr;
    QVector<CallInfo> _callStack;
};

} // namespace Debugging
} // namespace QQmlJS

QT_END_NAMESPACE

#endif // DEBUGGING_H