trap.c revision 3f54fd611f536639ec30dd53c48e5ec1897cc7d9
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1984-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* make signal traps
*/
#include "make.h"
#include <sig.h>
#undef trap
#if defined(SIGIOT) && SIGIOT == SIGEMT
#undef SIGIOT
#endif
struct Alarms_s; typedef struct Alarms_s Alarms_t;
struct Alarms_s
{
Alarms_t* next;
Rule_t* rule;
Seconds_t time;
};
static int signals[] = /* signals to catch */
{
SIGHUP,
SIGINT,
SIGALRM,
SIGTERM,
SIGPIPE,
#ifdef SIGILL
SIGILL,
#endif
#ifdef SIGIOT
SIGIOT,
#endif
#ifdef SIGEMT
SIGEMT,
#endif
#if !DEBUG
SIGQUIT,
#ifdef SIGBUS
SIGBUS,
#endif
#ifdef SIGSEGV
SIGSEGV,
#endif
#endif
#ifdef SIGUSR1
SIGUSR1,
#endif
#ifdef SIGUSR2
SIGUSR2,
#endif
};
static struct Trap_s
{
int* caught; /* caught signals */
Alarms_t* alarms; /* sorted alarm list */
Alarms_t* freealarms; /* free alarm list */
} trap;
/*
* catch and mark interrupts
*/
static void
interrupt(register int sig)
{
signal(sig, sig == SIGPIPE ? SIG_IGN : interrupt);
trap.caught[sig] = 1;
state.caught = 1;
}
/*
* (re)initialize wakeup rule pointers
*/
void
initwakeup(int repeat)
{
register Alarms_t* a;
NoP(repeat);
for (a = trap.alarms; a; a = a->next)
a->rule = makerule(a->rule->name);
}
/*
* set next wakeup time
*/
static void
setwakeup(void)
{
register Seconds_t t;
register Seconds_t now;
int level;
now = CURSECS;
if (!trap.alarms)
t = 0;
else if (trap.alarms->time <= now)
t = 1;
else
t = trap.alarms->time - now;
alarm(t);
sfsprintf(tmpname, MAXNAME, "%lu", t ? (now + t) : t);
setvar(internal.alarm->name, fmtelapsed(t, 1), 0);
if (error_info.trace <= (level = (state.test & 0x00010000) ? 2 : CMDTRACE))
{
register Alarms_t* a;
if (a = trap.alarms)
{
error(level, "ALARM TIME RULE");
do
{
error(level, "%6s %s %s", fmtelapsed((a->time >= now) ? (a->time - now) : 0, 1), timestr(tmxsns(a->time, 0)), a->rule->name);
} while (a = a->next);
}
else
error(level, "ALARM -- NONE");
}
}
/*
* wakeup in t seconds and make rules in p
* t==0 to drop alarms for list p, all for p==0
*/
void
wakeup(Seconds_t t, register List_t* p)
{
register Alarms_t* a;
register Alarms_t* z;
register Alarms_t* x;
Alarms_t* alarms;
Seconds_t now;
alarms = trap.alarms;
now = CURSECS;
if (t)
{
t += now;
if (!p)
p = cons(catrule(external.interrupt, ".", fmtsignal(-SIGALRM), 1), NiL);
}
if (p)
{
do
{
x = 0;
for (z = 0, a = trap.alarms; a; z = a, a = a->next)
if (a->rule == p->rule)
{
x = a;
if (z)
z->next = a->next;
else
trap.alarms = a->next;
break;
}
if (t)
{
if (!x)
{
if (x = trap.freealarms)
trap.freealarms = trap.freealarms->next;
else
x = newof(0, Alarms_t, 1, 0);
x->rule = p->rule;
}
x->time = t;
x->next = 0;
for (z = 0, a = trap.alarms; a; z = a, a = a->next)
if (t <= a->time)
{
x->next = a;
break;
}
if (z)
z->next = x;
else
trap.alarms = x;
}
} while (p = p->next);
}
else if (a = trap.alarms)
{
trap.alarms = 0;
while (x = a->next)
a = x;
a->next = trap.freealarms;
trap.freealarms = a;
}
if (trap.alarms != alarms)
setwakeup();
}
/*
* initialize the traps
*/
void
inittrap(void)
{
register int i;
memfatal();
trap.caught = newof(0, int, sig_info.sigmax + 1, 0);
for (i = 0; i < elementsof(signals); i++)
if (signal(signals[i], interrupt) == SIG_IGN)
signal(signals[i], SIG_IGN);
}
/*
* handle interrupts
* called by trap() in safe regions
* 0 returned if no interrupts to handle
*/
int
handle(void)
{
register int sig;
register Rule_t* r;
register Alarms_t* a;
char* s;
char* w;
Var_t* v;
Seconds_t t;
if (!state.caught)
return 0;
while (state.caught)
{
state.caught = 0;
for (sig = 1; sig <= sig_info.sigmax; sig++)
if (trap.caught[sig])
{
trap.caught[sig] = 0;
/*
* flush the output streams
*/
sfsync(sfstderr);
sfsync(sfstdout);
/*
* continue if already in finish
*/
if (state.finish)
{
if (!state.interrupt)
state.interrupt = sig;
for (sig = 1; sig <= sig_info.sigmax; sig++)
trap.caught[sig] = 0;
return 0;
}
/*
* check user trap (some cannot be trapped)
*/
w = 0;
if (!state.compileonly)
switch (sig)
{
case SIGALRM:
s = fmtsignal(-sig);
t = CURSECS;
while ((a = trap.alarms) && a->time <= t)
{
trap.alarms = a->next;
r = a->rule;
a->next = trap.freealarms;
trap.freealarms = a;
maketop(r, (P_dontcare|P_force|P_ignore|P_repeat)|((r->property & P_make)?0:P_foreground), s);
}
setwakeup();
continue;
default:
s = fmtsignal(-sig);
if ((r = catrule(external.interrupt, ".", s, 0)) || (r = getrule(external.interrupt)))
{
if (!(r->property & P_functional))
v = setvar(external.interrupt, s, 0);
maketop(r, (P_dontcare|P_force|P_ignore|P_repeat)|((r->property & P_make)?0:P_foreground), s);
if (r->property & P_functional)
v = getvar(r->name);
w = v->value;
if (r->status == EXISTS && (streq(w, s) || streq(w, "continue")))
{
message((-1, "trap %s handler %s status CONTINUE return %s", s, r->name, w));
continue;
}
message((-1, "trap %s handler %s status TERMINATE return %s", s, r->name, w));
}
/*FALLTHROUGH*/
#ifdef SIGILL
case SIGILL:
#endif
#ifdef SIGIOT
case SIGIOT:
#endif
#ifdef SIGEMT
case SIGEMT:
#endif
#ifdef SIGBUS
case SIGBUS:
#endif
#ifdef SIGSEGV
case SIGSEGV:
#endif
break;
}
/*
* terminate outstanding jobs
*/
terminate();
/*
* the interpreter resumes without exit
*/
if (state.interpreter)
{
if (state.waiting)
return 1;
longjmp(state.resume.label, 1);
}
/*
* if external.interrupt=""|"exit" then exit
* otherwise terminate via original signal
*/
if (w && (!*w || streq(w, "exit")))
state.interrupt = 0;
else if (!state.interrupt)
state.interrupt = sig;
finish(3);
/*
* shouldn't get here
*/
exit(3);
}
}
return 1;
}