flightgear/src/Main/bootstrap.cxx

// bootstrap.cxx -- bootstrap routines: main()
//
// Written by Curtis Olson, started May 1997.
//
// Copyright (C) 1997 - 2002  Curtis L. Olson  - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#if defined(__linux__) && defined(__i386__)
#  include <fpu_control.h>
#  include <signal.h>
#endif

#include <stdlib.h>
#include <stdio.h>

#include <simgear/compiler.h>
#include <simgear/structure/exception.hxx>
#include <simgear/debug/logstream.hxx>

#include STL_IOSTREAM
SG_USING_STD(cerr);
SG_USING_STD(endl);

#include "main.hxx"
#include "globals.hxx"


#ifdef HAVE_WINDOWS_H
#  include <windows.h>
#  include <float.h>
#endif

#include "fg_os.hxx"

#ifdef macintosh
#  include <console.h>		// -dw- for command line dialog
#endif

// foreward declaration.
void fgExitCleanup();

#if defined(__linux__) && defined(__i386__)

static void handleFPE (int);

static void
initFPE ()
{
    fpu_control_t fpe_flags = 0;
    _FPU_GETCW(fpe_flags);
//     fpe_flags &= ~_FPU_MASK_IM;	// invalid operation
//     fpe_flags &= ~_FPU_MASK_DM;	// denormalized operand
//     fpe_flags &= ~_FPU_MASK_ZM;	// zero-divide
//     fpe_flags &= ~_FPU_MASK_OM;	// overflow
//     fpe_flags &= ~_FPU_MASK_UM;	// underflow
//     fpe_flags &= ~_FPU_MASK_PM;	// precision (inexact result)
    _FPU_SETCW(fpe_flags);
    signal(SIGFPE, handleFPE);
}

static void
handleFPE (int num)
{
  initFPE();
  SG_LOG(SG_GENERAL, SG_ALERT, "Floating point interrupt (SIGFPE)");
}
#endif

#ifdef __APPLE__

typedef struct
{
  int  lo;
  int  hi;
} PSN;

extern "C" {
  short CPSGetCurrentProcess(PSN *psn);
  short CPSSetProcessName (PSN *psn, char *processname);
  short CPSEnableForegroundOperation(PSN *psn, int _arg2, int _arg3, int _arg4, int _arg5);
  short CPSSetFrontProcess(PSN *psn);
};

#define CPSEnableFG(psn) CPSEnableForegroundOperation(psn,0x03,0x3C,0x2C,0x1103)

#endif

#ifdef _MSC_VER
int main ( int argc, char **argv );
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                             LPSTR lpCmdLine, int nCmdShow) {

  main( __argc, __argv );
}
#endif

#if defined( sgi )
#include <sys/fpu.h>

/*
    set the special "flush zero" bit (FS, bit 24) in the Control Status
    Register of the FPU of R4k and beyond so that the result of any
    underflowing operation will be clamped to zero, and no exception of
    any kind will be generated on the CPU.  This has no effect on an
    R3000.

    the FS bit is inherited by processes fork()ed out of this one,
    but it is not inherited across an exec().  so anytime you exec()
    a process, you must re-set the FS bit in that process.
  */
void flush_fpe(void)
{
    union fpc_csr f;
    f.fc_word = get_fpc_csr();
    f.fc_struct.flush = 1;
    set_fpc_csr(f.fc_word);
}
#endif

int _bootstrap_OSInit;

// Main entry point; catch any exceptions that have made it this far.
int main ( int argc, char **argv ) {

    _bootstrap_OSInit = 0;

    // Enable floating-point exceptions for Linux/x86
#if defined(__linux__) && defined(__i386__)
    initFPE();
#endif

#if defined(sgi)
    flush_fpe();
#endif

    // Enable floating-point exceptions for Windows
#if defined( _MSC_VER ) && defined( DEBUG )
    // Christian, we should document what this does
    _control87( _EM_INEXACT, _MCW_EM );
#endif

#if defined( HAVE_BC5PLUS )
    _control87(MCW_EM, MCW_EM);  /* defined in float.h */
#endif

    // Keyboard focus hack
#if defined(__APPLE__) && !defined(OSX_BUNDLE)
    {
      PSN psn;

      fgOSInit (&argc, argv);
      _bootstrap_OSInit++;

      CPSGetCurrentProcess(&psn);
      CPSSetProcessName(&psn, "FlightGear");
      CPSEnableFG(&psn);
      CPSSetFrontProcess(&psn);
    }
#endif

    // FIXME: add other, more specific
    // exceptions.
    try {
        atexit(fgExitCleanup);
        fgMainInit(argc, argv);
    } catch (sg_throwable &t) {
                            // We must use cerr rather than
                            // logging, since logging may be
                            // disabled.
        cerr << "Fatal error: " << t.getFormattedMessage()
             << "\n (received from " << t.getOrigin() << ')' << endl;
    } catch (...) {
        cerr << "Unknown exception in the main loop. Aborting..." << endl;
        perror("Possible cause");
    }

    return 0;
}

// do some clean up on exit.  Specifically we want to call alutExit()
// which happens in the sound manager destructor.
void fgExitCleanup() {

    if (_bootstrap_OSInit != 0)
        fgSetMouseCursor(MOUSE_CURSOR_POINTER);

    if (globals)
        delete globals;
}