ack/lang/m2/libm2/sigtrp.c
2018-06-25 22:22:37 +02:00

85 lines
1.8 KiB
C

/*
(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/*
Module: Mapping of Unix signals to EM traps
(only when not using the MON instruction)
Author: Ceriel J.H. Jacobs
Version: $Id$
*/
#if !defined(__em22) && !defined(__em24) && !defined(__em44)
#define EM_trap(n) TRP(n) /* define to whatever is needed to cause the trap */
#include "libm2.h"
#include <signal.h>
#include <errno.h>
int __signo;
static int __traps[] = {
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
};
static void __ctchsig(int signo)
{
signal(signo, __ctchsig);
#ifdef __BSD4_2
sigsetmask(sigblock(0) & ~(1 << (signo - 1)));
#endif
__signo = signo;
EM_trap(__traps[signo]);
}
int sigtrp(int trapno, int signo)
{
/* Let Unix signal signo cause EM trap trapno to occur.
If trapno = -2, restore default,
If trapno = -3, ignore.
Return old trapnumber.
Careful, this could be -2 or -3; But return value of -1
indicates failure, with error number in errno.
*/
extern int errno;
void (*ctch)(int) = __ctchsig;
void (*oldctch)(int);
int oldtrap;
if (signo <= 0 || signo >= sizeof(__traps) / sizeof(__traps[0]))
{
errno = EINVAL;
return -1;
}
if (trapno == -3)
ctch = SIG_IGN;
else if (trapno == -2)
ctch = SIG_DFL;
else if (trapno >= 0 && trapno <= 252)
;
else
{
errno = EINVAL;
return -1;
}
oldtrap = __traps[signo];
if ((oldctch = signal(signo, ctch)) == (void (*)()) - 1) /* errno set by signal */
return -1;
else if (oldctch == SIG_IGN)
{
signal(signo, SIG_IGN);
}
else
__traps[signo] = trapno;
return oldtrap;
}
#endif