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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** This file is part of Qt Creator.
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** 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
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****************************************************************************/

#ifndef EXTENSIONCONTEXT_H
#define EXTENSIONCONTEXT_H

#include "common.h"
#include "iinterfacepointer.h"

#include <memory>
#include <map>

class LocalsSymbolGroup;
class WatchesSymbolGroup;
class OutputCallback;

// Global singleton with context.
// Caches a symbolgroup per frame and thread as long as the session is accessible.
class ExtensionContext {
    ExtensionContext(const ExtensionContext&);
    ExtensionContext& operator=(const ExtensionContext&);

    ExtensionContext();
public:
    enum { maxStackFrames = 200 };

    // Key used to report stop reason in StopReasonMap
    static const char *stopReasonKeyC;
    static const char *breakPointStopReasonC;  // pre-defined stop reasons
    // Map of parameters reported with the next stop as GDBMI
    typedef std::map<std::string, std::string> StopReasonMap;

    ~ExtensionContext();

    static ExtensionContext &instance();
    // Call from DLL initialization.
    HRESULT initialize(PULONG Version, PULONG Flags);

    // Hook up our Event and Output callbacks that report exceptions and events.
    // Call this from the first extension command that gets a client.
    // Does not work when called from initialization.
    void hookCallbacks(CIDebugClient *client);
    // Undo hooking.
    void unhookCallbacks();

     // CDB has a limitation on output, so, long messages need to be split (empirically ca 10KB)
    static const size_t outputChunkSize = 10240;
    /* Report output in standardized format understood by Qt Creator.
     * '<qtcreatorcdbext>|R|<token>|remainingChunks|<serviceName>|<one-line-output>'.
     * Char code is 'R' command reply, 'N' command fail, 'E' event notification,
     * 'X' exception, error. If the message is larger than outputChunkSize,
     * it needs to be split up in chunks, remainingChunks needs to indicate the number
     * of the following chunks (0 for just one chunk). */
    bool report(char code, int remainingChunks, int token, const char *serviceName, PCSTR Format, ...);
    // Convenience for reporting potentially long messages in chunks
    bool reportLong(char code, int token, const char *serviceName, const std::string &message);
    ULONG executionStatus() const;
    // Call from notify handler, tell engine about state.
    void notifyState(ULONG Notify);
    // register as '.idle_cmd' to notify creator about stop
    void notifyIdleCommand(CIDebugClient *client);

    // Return symbol group for frame (cached as long as frame/thread do not change).
    LocalsSymbolGroup *symbolGroup(CIDebugSymbols *symbols, ULONG threadId, int frame, std::string *errorMessage);
    int symbolGroupFrame() const;
    void discardSymbolGroup();

    WatchesSymbolGroup *watchesSymbolGroup(CIDebugSymbols *symbols, std::string *errorMessage);
    WatchesSymbolGroup *watchesSymbolGroup() const; // Do not create.
    void discardWatchesSymbolGroup();

    // Set a stop reason to be reported with the next idle notification (exception).
    void setStopReason(const StopReasonMap &, const std::string &reason = std::string());

    void startRecordingOutput();
    std::wstring stopRecordingOutput();
    // Execute a function call and record the output.
    bool call(const std::string &functionCall, std::wstring *output, std::string *errorMessage);

    CIDebugClient *hookedClient() const { return m_hookedClient; }

private:
    bool isInitialized() const;

    IInterfacePointer<CIDebugControl> m_control;
    std::auto_ptr<LocalsSymbolGroup> m_symbolGroup;
    std::auto_ptr<WatchesSymbolGroup> m_watchesSymbolGroup;

    CIDebugClient *m_hookedClient;
    IDebugEventCallbacks *m_oldEventCallback;
    IDebugOutputCallbacksWide *m_oldOutputCallback;
    IDebugEventCallbacks *m_creatorEventCallback;
    OutputCallback *m_creatorOutputCallback;

    StopReasonMap m_stopReason;
    bool m_stateNotification;
};

// Context for extension commands to be instantiated on stack in a command handler.
// Provides the IDebug objects on demand.
class ExtensionCommandContext
{
    ExtensionCommandContext(const ExtensionCommandContext&);
    ExtensionCommandContext &operator=(const ExtensionCommandContext&);
public:
    explicit ExtensionCommandContext(CIDebugClient *Client);
    ~ExtensionCommandContext();

    // For accessing outside commands. Might return 0, based on the
    // assumption that there is only once instance active.
    static ExtensionCommandContext *instance();

    CIDebugControl *control();
    CIDebugSymbols *symbols();
    CIDebugSystemObjects *systemObjects();
    CIDebugAdvanced *advanced();
    CIDebugRegisters *registers();
    CIDebugDataSpaces *dataSpaces();

    ULONG threadId();

private:
    static ExtensionCommandContext *m_instance;

    CIDebugClient *m_client;
    IInterfacePointer<CIDebugControl> m_control;
    IInterfacePointer<CIDebugSymbols> m_symbols;
    IInterfacePointer<CIDebugAdvanced> m_advanced;
    IInterfacePointer<CIDebugSystemObjects> m_systemObjects;
    IInterfacePointer<CIDebugRegisters> m_registers;
    IInterfacePointer<CIDebugDataSpaces> m_dataSpaces;
};

#endif // EXTENSIONCONTEXT_H
