/*

* Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:    Logging macros

*

*/

#ifndef GLXTRACER_H

#define GLXTRACER_H

/**

 * This file has been copied from the forum nokia wiki and renamed to glxtracer.h

 * http://wiki.forum.nokia.com/index.php/Trace_Function_Enter%2C_Exit_and_Leave

 */

#include <e32base.h>

// Define tracer logging method

// 0    = Logging off

// 1    = Log to RDebug

// 2    = Log to file (RFileLogger)

#define TRACER_LOG_METHOD 0

// ============================================================================

// Logging off, define empty macros and skip all the rest

#if TRACER_LOG_METHOD == 0

    #define TRACER(func)    

    #define TRACER_RET(func,format)

#else                       // Logging on

    // Macro to print function entry, exit and leave. 

    // Example: TRACER("CMyClass::MyFunction");

    #define TRACER(func) TTracer function_tracer( _S(func), _S("") );

    // Macro to print function return value in addition to entry, exit 

    // and leave conditions Second parameter is a formatting string used 

    // to print the return value Example to print an integer return value:

    // TRACER_RET("CMyclass::MyFunction", "%d");

    #define TRACER_RET(func,format) TTracer func_tracer( _S(func), _S(format) );

    #if TRACER_LOG_METHOD == 1      // Print to RDebug

        #include <e32debug.h>

        #define TRACER_PRINT(a)         RDebug::Print(a,&iFunc);

        #define TRACER_PRINT_RET(a,b)   RDebug::Print(a,&iFunc,b);

    #elif TRACER_LOG_METHOD == 2    // Print to file

        #include <flogger.h>

        _LIT( KLogDir,  "tracer" );     // Log directory: C:\logs\tracer

        _LIT( KLogFile, "tracer.txt" ); // Log file: c:\logs\tracer\tracer.txt

        #define TRACER_PRINT(a)         RFileLogger::WriteFormat(KLogDir, \

                            KLogFile,EFileLoggingModeAppend,a,&iFunc);

        #define TRACER_PRINT_RET(a,b)   RFileLogger::WriteFormat(KLogDir, \

                            KLogFile,EFileLoggingModeAppend,a,&iFunc,b);

    #endif

    _LIT( KLogEnter,    "%S: ENTER" );

    _LIT( KLogExit,     "%S: EXIT" );

    _LIT( KLogLeave,    "%S: LEAVE!" );

    _LIT( KLogExitRet,  "%S: EXIT, Returning " );

    /**

     * Simple tracer class that logs function enter, exit or leave

     */

    class TTracer

        {

    public:

        /**

         * inline constructor to write log of entering a function

         */

        TTracer( const TText* aFunc, const TText* aRetFormat )

            : iFunc( aFunc )

            , iRetFormat( aRetFormat )

            {

            TRACER_PRINT( KLogEnter );

            }

        /**

         * inline destructor to write log of exiting a function 

         * normally or with a leave

         */

        ~TTracer()

            {

            if ( std::uncaught_exception() ) // Leave is an exception

                {

                // The function exited with a leave

                TRACER_PRINT( KLogLeave );

                }

            else

                {

                // The function exited normally

                if ( iRetFormat.Length() == 0 )

                    {

                    TRACER_PRINT( KLogExit );

                    }

                else

                    {

                    // Log the return value

                    #ifdef __WINS__

                        TInt32 retVal = 0;

                        // The assembly bit. This needs to be reimplemented

                        // for every target. 

                        _asm( mov retVal, ebx );

                        TBuf<100> format( KLogExitRet );

                        format.Append( iRetFormat );

                        TRACER_PRINT_RET( format, retVal );

                    #else

                        TRACER_PRINT( KLogExit );

                    #endif

                    }

                }

            }

    private:

        /** 

         * Pointer descriptor to function signature that is to be logged.

         */

        TPtrC iFunc;

        /**

         * Formatting string used to print the function return value

         */

        TPtrC iRetFormat;

        };

#endif // TRACER_LOG_METHOD == 0

#endif // GLXTRACER_H