/*
 * Exception
 *  Handles odd errors in Steel programs
 *
 * 1.00 (24 September 1991)
 *
 * © 1991-1998 Straylight
 */

/*----- Licensing note ----------------------------------------------------*
 *
 * This file is part of Straylight's Steel library.
 *
 * Steel 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, or (at your option)
 * any later version.
 *
 * Steel 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 Steel.  If not, write to the Free Software Foundation,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef __exception_h
#define __exception_h

#ifndef __setjmp_h
#include <setjmp.h>
#endif

#ifndef __dll_h
  #include "dll.h"
#endif

typedef struct
{
  jmp_buf j;
  int sp;
}
exception_handler;

/*
 * int exception_registerHandler(exception_handler env)
 *
 * Use
 *  Registers the current point as being a sensible place to go after an
 *  exception.  This is implemented as a macro for the simple reason that 
 *  things tend to go a tad wrong if you define your jmp_bufs in a function
 *  and then return.
 *
 * Parameters
 *  exception_handler env == an undefined variable of the type jmp_buf.
 */

#ifndef exception_registerHandler
#define exception_registerHandler(exc)                                     \
  (                                                                        \
    ( exc.sp=_dll_setjmp() ),                                              \
    ( exception__registerHandler((exc.j),setjmp(exc.j)) ?                  \
      (_dll_longjmped(exc.sp),1) :                                         \
      0)                                                                  \
  )
#endif


/*
 * void exception_generate(char *message,...)
 *
 * Use
 *  Generates an ArmenLib exception, to be handled in an appropriate manner.
 *
 * Parameters
 *  char *message == printf()-type format string
 */

void exception_generate(char *message,...);


/*
 * int exception__registerHandler(jmp_buf handler)
 *
 * Use
 *  This routine is for the use of exception segment only, and should not
 *  be called from your code.
 */

int exception__registerHandler(jmp_buf handler,int result);

#endif