[mLib] / exc.c

/* -*-c-*-
 *
 * $Id: exc.c,v 1.2 1999/05/05 18:50:31 mdw Exp $
 *
 * Structured exception handling in C
 *
 * (c) 1998 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * mLib 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 Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------*
 *
 * $Log: exc.c,v $
 * Revision 1.2  1999/05/05 18:50:31  mdw
 * Change licensing conditions to LGPL.
 *
 * Revision 1.1.1.1  1998/06/17 23:44:42  mdw
 * Initial version of mLib
 *
 */

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

#include "exc.h"

/*----- Global variables --------------------------------------------------*/

__exc_hnd *__exc_list = 0;

/*----- Functions ---------------------------------------------------------*/

/* --- @exc__duff@ --- *
 *
 * Arguments:	@exc_extype type@ = type of duff exception
 *		@exc_exval val@ = extra data supplied
 *
 * Returns:	Doesn't
 *
 * Use:		Default handler when everything goes wrong.
 */

static void exc__duff(exc_extype type, exc_exval val)
{
  fprintf(stderr, "fatal error: uncaught exception (type = %lu)\n", type);
  abort();
}

/* --- @exc__duffproc@ --- *
 *
 * Current handler when there are no more exceptions left.
 */

static exc__uncaught exc__duffproc = exc__duff;

/* --- @exc_uncaught@ --- *
 *
 * Arguments:	@void (*proc)(exc_extype type, exc_exval val) = new handler
 *
 * Returns:	Pointer to the old handler value.
 *
 * Use:		Sets the handler for uncaught exceptions.
 */

exc__uncaught exc_uncaught(exc__uncaught proc)
{
  exc__uncaught p = exc__duffproc;
  if (proc)
    exc__duffproc = proc;
  return (p);
}

/* --- @__exc_throw@ --- *
 *
 * Arguments:	@exc_extype type@ = type of exception to throw
 *
 * Returns:	Doesn't
 *
 * Use:		NOT FOR USER CONSUMPTION.  Reads an appropriate exception
 *		value and throws an exception.
 */

void __exc_throw(exc_extype type, ...)
{
  va_list ap;
  exc_exval v;

  va_start(ap, type);
  switch (type & 0xC0) {
    case EXC_NOVAL:
      v.i = 0;
      break;
    case EXC_INTVAL:
      v.i = va_arg(ap, int);
      break;
    case EXC_PTRVAL:
      v.p = va_arg(ap, void *);
      break;
    case EXC_STRVAL:
      v.s = va_arg(ap, char *);
      break;
  }
  va_end(ap);
  __exc_rethrow(type, v);
}

/* --- @__exc_rethrow@ --- *
 *
 * Arguments:	@exc_extype type@ = type of exception to throw
 *		@exc_exval val@ = value of exception to throw
 *
 * Returns:	Doesn't
 *
 * Use:		NOT FOR USER CONSUMPTION.  Does the donkey-work of raising
 *		an exception.
 */

void __exc_rethrow(exc_extype type, exc_exval val)
{
  __exc_hnd *p = __exc_list;
  if (!p)
    exc__duffproc(type, val);
  p->type = type;
  p->val = val;
  __exc_list = p->next;
  longjmp(p->buf, type);
}  

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
0875b58f	1	/* --c--
0875b58f	2	*
c846879c	3	* $Id: exc.c,v 1.2 1999/05/05 18:50:31 mdw Exp $
0875b58f	4	*
	5	* Structured exception handling in C
	6	*
	7	* (c) 1998 Straylight/Edgeware
	8	*/
	9
c846879c	10	/----- Licensing notice --------------------------------------------------
0875b58f	11	*
	12	* This file is part of the mLib utilities library.
	13	*
	14	* mLib is free software; you can redistribute it and/or modify
c846879c	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
	18	*
0875b58f	19	* mLib is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
c846879c	22	* GNU Library General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU Library General Public
	25	* License along with mLib; if not, write to the Free Software
	26	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
0875b58f	27	*/
	28
	29	/----- Revision history --------------------------------------------------
	30	*
	31	* $Log: exc.c,v $
c846879c	32	* Revision 1.2 1999/05/05 18:50:31 mdw
	33	* Change licensing conditions to LGPL.
	34	*
	35	* Revision 1.1.1.1 1998/06/17 23:44:42 mdw
	36	* Initial version of mLib
0875b58f	37	*
	38	*/
	39
	40	#include <stdarg.h>
	41	#include <stdlib.h>
	42	#include <stdio.h>
	43
	44	#include "exc.h"
	45
	46	/----- Global variables --------------------------------------------------/
	47
	48	__exc_hnd *__exc_list = 0;
	49
	50	/----- Functions ---------------------------------------------------------/
	51
	52	/* --- @exc__duff@ --- *
	53	*
	54	* Arguments: @exc_extype type@ = type of duff exception
	55	* @exc_exval val@ = extra data supplied
	56	*
	57	* Returns: Doesn't
	58	*
	59	* Use: Default handler when everything goes wrong.
	60	*/
	61
	62	static void exc__duff(exc_extype type, exc_exval val)
	63	{
	64	fprintf(stderr, "fatal error: uncaught exception (type = %lu)\n", type);
	65	abort();
	66	}
	67
	68	/* --- @exc__duffproc@ --- *
	69	*
	70	* Current handler when there are no more exceptions left.
	71	*/
	72
	73	static exc__uncaught exc__duffproc = exc__duff;
	74
	75	/* --- @exc_uncaught@ --- *
	76	*
	77	* Arguments: @void (*proc)(exc_extype type, exc_exval val) = new handler
	78	*
	79	* Returns: Pointer to the old handler value.
	80	*
	81	* Use: Sets the handler for uncaught exceptions.
	82	*/
	83
	84	exc__uncaught exc_uncaught(exc__uncaught proc)
	85	{
	86	exc__uncaught p = exc__duffproc;
	87	if (proc)
	88	exc__duffproc = proc;
	89	return (p);
	90	}
	91
	92	/* --- @__exc_throw@ --- *
	93	*
	94	* Arguments: @exc_extype type@ = type of exception to throw
	95	*
	96	* Returns: Doesn't
	97	*
	98	* Use: NOT FOR USER CONSUMPTION. Reads an appropriate exception
	99	* value and throws an exception.
	100	*/
101
102	void __exc_throw(exc_extype type, ...)
103	{
104	va_list ap;
105	exc_exval v;
106
107	va_start(ap, type);
108	switch (type & 0xC0) {
109	case EXC_NOVAL:
110	v.i = 0;
111	break;
112	case EXC_INTVAL:
113	v.i = va_arg(ap, int);
114	break;
115	case EXC_PTRVAL:
116	v.p = va_arg(ap, void *);
117	break;
118	case EXC_STRVAL:
119	v.s = va_arg(ap, char *);
120	break;
121	}
122	va_end(ap);
123	__exc_rethrow(type, v);
124	}
125
126	/* --- @__exc_rethrow@ --- *
127	*
128	* Arguments: @exc_extype type@ = type of exception to throw
129	* @exc_exval val@ = value of exception to throw
130	*
131	* Returns: Doesn't
132	*
133	* Use: NOT FOR USER CONSUMPTION. Does the donkey-work of raising
134	* an exception.
135	*/
136
137	void __exc_rethrow(exc_extype type, exc_exval val)
138	{
139	__exc_hnd *p = __exc_list;
140	if (!p)
141	exc__duffproc(type, val);
142	p->type = type;
143	p->val = val;
144	__exc_list = p->next;
145	longjmp(p->buf, type);
146	}
147
148	/----- That's all, folks -------------------------------------------------/