//
// ********************************************************************
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//
//
// $Id: G4FPEDetection.hh,v 1.2 2006/11/15 16:00:18 gcosmo Exp $
// GEANT4 tag $Name: geant4-09-03 $
//
// 
// -*- C++ -*-
//
// -----------------------------------------------------------------------
// This global method should be used on LINUX platforms with gcc compiler
// for activating NaN detection and FPE signals, and forcing abortion of
// the application at the time these are detected.
// Meant to be used for debug purposes, can be activated by compiling the
// "run" module with the flag G4FPE_DEBUG set in the environment.
// -----------------------------------------------------------------------

#ifndef G4FPEDetection_h
#define G4FPEDetection_h 1

#ifdef __linux__
#ifdef __GNUC__
  #include <features.h>
  #include <fenv.h>
  #include <csignal>

  #include <iostream>

  struct sigaction termaction, oldaction;

  void TerminationSignalHandler(int sig)
  {
    std::cerr << "ERROR: " << sig;
    std::string message;
    switch (SIGFPE)
    {
      case FPE_INTDIV:
        message = "Integer divide by zero.";
        break;
      case FPE_INTOVF:
        message = "Integer overflow.";
        break;
      case FPE_FLTDIV:
        message = "Floating point divide by zero.";
        break;
      case FPE_FLTOVF:
        message = "Floating point overflow.";
        break;
      case FPE_FLTUND:
        message = "Floating point underflow.";
        break;
      case FPE_FLTRES:
        message = "Floating point inexact result.";
        break;
      case FPE_FLTINV:
        message = "Floating point invalid operation.";
        break;
      case FPE_FLTSUB:
        message = "Subscript out of range.";
        break;
      default:
        message = "Unknown error.";
        break;
    }
    std::cerr << " - " << message << std::endl;

    ::abort();
  }

  void InvalidOperationDetection()
  {
    std::cout << std::endl
              << "        "
              << "############################################" << std::endl
              << "        "
              << "!!! WARNING - FPE detection is activated !!!" << std::endl
              << "        "
              << "############################################" << std::endl;

    (void) feenableexcept( FE_DIVBYZERO );
    (void) feenableexcept( FE_INVALID );
    //(void) feenableexcept( FE_OVERFLOW );
    //(void) feenableexcept( FE_UNDERFLOW );

    sigset_t *def_set;
    def_set=&termaction.sa_mask;
    sigfillset(def_set);
    sigdelset(def_set,SIGFPE);
    termaction.sa_handler=TerminationSignalHandler;
    termaction.sa_flags=0;
    sigaction(SIGFPE, &termaction,&oldaction);
  }
#endif
#else
  void InvalidOperationDetection() {;}
#endif

#endif
