[mLib] / exc.c

/* -*-c-*-
 *
 * $Id: exc.c,v 1.3 1999/05/06 19:51:35 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 1.3  1999/05/06 19:51:35  mdw
 * Reformatted the LGPL notice a little bit.
 *
 * 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	*
0bd98442	3	* $Id: exc.c,v 1.3 1999/05/06 19:51:35 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
0bd98442	25	* License along with mLib; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
0875b58f	28	*/
	29
	30	/----- Revision history --------------------------------------------------
	31	*
	32	* $Log: exc.c,v $
0bd98442	33	* Revision 1.3 1999/05/06 19:51:35 mdw
	34	* Reformatted the LGPL notice a little bit.
	35	*
c846879c	36	* Revision 1.2 1999/05/05 18:50:31 mdw
	37	* Change licensing conditions to LGPL.
	38	*
	39	* Revision 1.1.1.1 1998/06/17 23:44:42 mdw
	40	* Initial version of mLib
0875b58f	41	*
	42	*/
	43
	44	#include <stdarg.h>
	45	#include <stdlib.h>
	46	#include <stdio.h>
	47
	48	#include "exc.h"
	49
	50	/----- Global variables --------------------------------------------------/
	51
	52	__exc_hnd *__exc_list = 0;
	53
	54	/----- Functions ---------------------------------------------------------/
	55
	56	/* --- @exc__duff@ --- *
	57	*
	58	* Arguments: @exc_extype type@ = type of duff exception
	59	* @exc_exval val@ = extra data supplied
	60	*
	61	* Returns: Doesn't
	62	*
	63	* Use: Default handler when everything goes wrong.
	64	*/
	65
	66	static void exc__duff(exc_extype type, exc_exval val)
	67	{
	68	fprintf(stderr, "fatal error: uncaught exception (type = %lu)\n", type);
	69	abort();
	70	}
	71
	72	/* --- @exc__duffproc@ --- *
	73	*
	74	* Current handler when there are no more exceptions left.
	75	*/
	76
	77	static exc__uncaught exc__duffproc = exc__duff;
	78
	79	/* --- @exc_uncaught@ --- *
	80	*
	81	* Arguments: @void (*proc)(exc_extype type, exc_exval val) = new handler
	82	*
	83	* Returns: Pointer to the old handler value.
	84	*
	85	* Use: Sets the handler for uncaught exceptions.
	86	*/
	87
	88	exc__uncaught exc_uncaught(exc__uncaught proc)
	89	{
	90	exc__uncaught p = exc__duffproc;
	91	if (proc)
	92	exc__duffproc = proc;
	93	return (p);
	94	}
	95
	96	/* --- @__exc_throw@ --- *
	97	*
	98	* Arguments: @exc_extype type@ = type of exception to throw
	99	*
	100	* Returns: Doesn't
	101	*
	102	* Use: NOT FOR USER CONSUMPTION. Reads an appropriate exception
	103	* value and throws an exception.
	104	*/
105
106	void __exc_throw(exc_extype type, ...)
107	{
108	va_list ap;
109	exc_exval v;
110
111	va_start(ap, type);
112	switch (type & 0xC0) {
113	case EXC_NOVAL:
114	v.i = 0;
115	break;
116	case EXC_INTVAL:
117	v.i = va_arg(ap, int);
118	break;
119	case EXC_PTRVAL:
120	v.p = va_arg(ap, void *);
121	break;
122	case EXC_STRVAL:
123	v.s = va_arg(ap, char *);
124	break;
125	}
126	va_end(ap);
127	__exc_rethrow(type, v);
128	}
129
130	/* --- @__exc_rethrow@ --- *
131	*
132	* Arguments: @exc_extype type@ = type of exception to throw
133	* @exc_exval val@ = value of exception to throw
134	*
135	* Returns: Doesn't
136	*
137	* Use: NOT FOR USER CONSUMPTION. Does the donkey-work of raising
138	* an exception.
139	*/
140
141	void __exc_rethrow(exc_extype type, exc_exval val)
142	{
143	__exc_hnd *p = __exc_list;
144	if (!p)
145	exc__duffproc(type, val);
146	p->type = type;
147	p->val = val;
148	__exc_list = p->next;
149	longjmp(p->buf, type);
150	}
151
152	/----- That's all, folks -------------------------------------------------/