Added Debugging/FPE.h

SET( headers

         FPE.h

         MemoryUsage.h

         StackBacktrace.h

)

/***************************************************************************

                          MeshConfigBase.h  -  description

                             -------------------

    begin                : Nov 6, 2016

    copyright            : (C) 2016 by Tomas Oberhuber et al.

    email                : tomas.oberhuber@fjfi.cvut.cz

 ***************************************************************************/

/* See Copyright Notice in tnl/Copyright */

#pragma once

#include <cfenv>

#include <signal.h>

#include <TNL/Debugging/StackBacktrace.h>

namespace TNL {

namespace Debugging {

void printStackBacktraceAndAbort( int sig = 0 )

{

   if( sig == SIGSEGV )

      fprintf(stderr, "Invalid memory reference, printing backtrace and aborting...\n");

   else if( sig == SIGFPE ) {

      /*

       * Unfortunately it is not possible to get the floating-point exception type

       * from a signal handler. Otherwise, it would be done this way:

       *

       *    fprintf(stderr, "Floating-point exception");

       *    if(fetestexcept(FE_DIVBYZERO))  fprintf(stderr, " FE_DIVBYZERO");

       *    if(fetestexcept(FE_INEXACT))    fprintf(stderr, " FE_INEXACT");

       *    if(fetestexcept(FE_INVALID))    fprintf(stderr, " FE_INVALID");

       *    if(fetestexcept(FE_OVERFLOW))   fprintf(stderr, " FE_OVERFLOW");

       *    if(fetestexcept(FE_UNDERFLOW))  fprintf(stderr, " FE_UNDERFLOW");

       *    fprintf(stderr, " occurred, printing backtrace and aborting...\n");

       */

      fprintf(stderr, "Floating-point exception occurred, printing backtrace and aborting...\n");

   }

   else

      fprintf( stderr, "Aborting due to signal %d...\n", sig );

   printStackBacktrace();

   abort();

}

/*

 * Registers handler for SIGSEGV and SIGFPE signals and enables conversion of

 * floating-point exceptions into SIGFPE. This is useful e.g. for tracing where

 * NANs occurred. Example usage:

 *

 * int main()

 * {

 *    #ifndef NDEBUG

 *       registerFloatingPointExceptionTracking()

 *    #endif

 *    [start some computation here...]

 * }

 */

void trackFloatingPointExceptions()

{

   signal( SIGSEGV, printStackBacktraceAndAbort );

   signal( SIGFPE,  printStackBacktraceAndAbort );

   feenableexcept( FE_ALL_EXCEPT & ~FE_INEXACT );

}

} // namespace Debugging

} // namespace TNL