summary refs log tree commit diff
path: root/Src/signals.c
blob: 81949843f72d5e75f5230e64d968aff83b31e28f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
/*
 * signals.c - signals handling code
 *
 * This file is part of zsh, the Z shell.
 *
 * Copyright (c) 1992-1997 Paul Falstad
 * All rights reserved.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and to distribute modified versions of this software for any
 * purpose, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 *
 * In no event shall Paul Falstad or the Zsh Development Group be liable
 * to any party for direct, indirect, special, incidental, or consequential
 * damages arising out of the use of this software and its documentation,
 * even if Paul Falstad and the Zsh Development Group have been advised of
 * the possibility of such damage.
 *
 * Paul Falstad and the Zsh Development Group specifically disclaim any
 * warranties, including, but not limited to, the implied warranties of
 * merchantability and fitness for a particular purpose.  The software
 * provided hereunder is on an "as is" basis, and Paul Falstad and the
 * Zsh Development Group have no obligation to provide maintenance,
 * support, updates, enhancements, or modifications.
 *
 */

#include "zsh.mdh"
#include "signals.pro"
 
/* Array describing the state of each signal: an element contains *
 * 0 for the default action or some ZSIG_* flags ored together.   */

/**/
mod_export int sigtrapped[VSIGCOUNT];

/*
 * Trap programme lists for each signal.
 *
 * If (sigtrapped[sig] & ZSIG_FUNC) is set, this isn't used.
 * The corresponding shell function is used instead.
 *
 * Otherwise, if sigtrapped[sig] is not zero, this is NULL when a signal
 * is to be ignored, and if not NULL contains the programme list to be
 * eval'd.
 */

/**/
mod_export Eprog siglists[VSIGCOUNT];

/* Total count of trapped signals */

/**/
mod_export int nsigtrapped;

/* Variables used by signal queueing */

/**/
mod_export int queueing_enabled, queue_front, queue_rear;
/**/
mod_export int signal_queue[MAX_QUEUE_SIZE];
/**/
mod_export sigset_t signal_mask_queue[MAX_QUEUE_SIZE];

/* Variables used by trap queueing */

/**/
mod_export int trap_queueing_enabled, trap_queue_front, trap_queue_rear;
/**/
mod_export int trap_queue[MAX_QUEUE_SIZE];

/* This is only used on machines that don't understand signal sets.  *
 * On SYSV machines this will represent the signals that are blocked *
 * (held) using sighold.  On machines which can't block signals at   *
 * all, we will simulate this by ignoring them and remembering them  *
 * in this variable.                                                 */
#if !defined(POSIX_SIGNALS) && !defined(BSD_SIGNALS)
static sigset_t blocked_set;
#endif

#ifdef POSIX_SIGNALS
# define signal_jmp_buf       sigjmp_buf
# define signal_setjmp(b)     sigsetjmp((b),1)
# define signal_longjmp(b,n)  siglongjmp((b),(n))
#else
# define signal_jmp_buf       jmp_buf
# define signal_setjmp(b)     setjmp(b)
# define signal_longjmp(b,n)  longjmp((b),(n))
#endif
 
#ifdef NO_SIGNAL_BLOCKING
# define signal_process(sig)  signal_ignore(sig)
# define signal_reset(sig)    install_handler(sig)
#else
# define signal_process(sig)  ;
# define signal_reset(sig)    ;
#endif

/* Install signal handler for given signal.           *
 * If possible, we want to make sure that interrupted *
 * system calls are not restarted.                    */

/**/
mod_export void
install_handler(int sig)
{
#ifdef POSIX_SIGNALS
    struct sigaction act;
 
    act.sa_handler = (SIGNAL_HANDTYPE) zhandler;
    sigemptyset(&act.sa_mask);        /* only block sig while in handler */
    act.sa_flags = 0;
# ifdef SA_INTERRUPT                  /* SunOS 4.x */
    if (interact)
        act.sa_flags |= SA_INTERRUPT; /* make sure system calls are not restarted */
# endif
    sigaction(sig, &act, (struct sigaction *)NULL);
#else
# ifdef BSD_SIGNALS
    struct sigvec vec;
 
    vec.sv_handler = (SIGNAL_HANDTYPE) zhandler;
    vec.sv_mask = sigmask(sig);    /* mask out this signal while in handler    */
#  ifdef SV_INTERRUPT
    vec.sv_flags = SV_INTERRUPT;   /* make sure system calls are not restarted */
#  endif
    sigvec(sig, &vec, (struct sigvec *)NULL);
# else
#  ifdef SYSV_SIGNALS
    /* we want sigset rather than signal because it will   *
     * block sig while in handler.  signal usually doesn't */
    sigset(sig, zhandler);
#  else  /* NO_SIGNAL_BLOCKING (bummer) */
    signal(sig, zhandler);

#  endif /* SYSV_SIGNALS  */
# endif  /* BSD_SIGNALS   */
#endif   /* POSIX_SIGNALS */
}

/* enable ^C interrupts */
 
/**/
mod_export void
intr(void)
{
    if (interact)
        install_handler(SIGINT);
}

/* disable ^C interrupts */
 
#if 0 /**/
void
nointr(void)
{
    if (interact)
        signal_ignore(SIGINT);
}
#endif
 
/* temporarily block ^C interrupts */
 
/**/
mod_export void
holdintr(void)
{
    if (interact)
        signal_block(signal_mask(SIGINT));
}

/* release ^C interrupts */
 
/**/
mod_export void
noholdintr(void)
{
    if (interact)
        signal_unblock(signal_mask(SIGINT));
}
 
/* create a signal mask containing *
 * only the given signal           */
 
/**/
sigset_t
signal_mask(int sig)
{
    sigset_t set;
 
    sigemptyset(&set);
    if (sig)
        sigaddset(&set, sig);
    return set;
}

/* Block the signals in the given signal *
 * set. Return the old signal set.       */

/**/
#ifndef BSD_SIGNALS

sigset_t
signal_block(sigset_t set)
{
    sigset_t oset;
 
#ifdef POSIX_SIGNALS
    sigprocmask(SIG_BLOCK, &set, &oset);

#else
# ifdef SYSV_SIGNALS
    int i;
 
    oset = blocked_set;
    for (i = 1; i <= NSIG; ++i) {
        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
            sigaddset(&blocked_set, i);
            sighold(i);
        }
    }
# else  /* NO_SIGNAL_BLOCKING */
/* We will just ignore signals if the system doesn't have *
 * the ability to block them.                             */
    int i;

    oset = blocked_set;
    for (i = 1; i <= NSIG; ++i) {
        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
            sigaddset(&blocked_set, i);
            signal_ignore(i);
        }
   }
# endif /* SYSV_SIGNALS */
#endif /* POSIX_SIGNALS */
 
    return oset;
}

/**/
#endif /* BSD_SIGNALS */

/* Unblock the signals in the given signal *
 * set. Return the old signal set.         */

sigset_t
signal_unblock(sigset_t set)
{
    sigset_t oset;

#ifdef POSIX_SIGNALS
    sigprocmask(SIG_UNBLOCK, &set, &oset);
#else
# ifdef BSD_SIGNALS
    sigfillset(&oset);
    oset = sigsetmask(oset);
    sigsetmask(oset & ~set);
# else
#  ifdef SYSV_SIGNALS
    int i;
 
    oset = blocked_set;
    for (i = 1; i <= NSIG; ++i) {
        if (sigismember(&set, i) && sigismember(&blocked_set, i)) {
            sigdelset(&blocked_set, i);
            sigrelse(i);
        }
    }
#  else  /* NO_SIGNAL_BLOCKING */
/* On systems that can't block signals, we are just ignoring them.  So *
 * to unblock signals, we just reenable the signal handler for them.   */
    int i;

    oset = blocked_set;
    for (i = 1; i <= NSIG; ++i) {
        if (sigismember(&set, i) && sigismember(&blocked_set, i)) {
            sigdelset(&blocked_set, i);
            install_handler(i);
        }
   }
#  endif /* SYSV_SIGNALS  */
# endif  /* BSD_SIGNALS   */
#endif   /* POSIX_SIGNALS */
 
    return oset;
}

/* set the process signal mask to *
 * be the given signal mask       */

/**/
mod_export sigset_t
signal_setmask(sigset_t set)
{
    sigset_t oset;
 
#ifdef POSIX_SIGNALS
    sigprocmask(SIG_SETMASK, &set, &oset);
#else
# ifdef BSD_SIGNALS
    oset = sigsetmask(set);
# else
#  ifdef SYSV_SIGNALS
    int i;
 
    oset = blocked_set;
    for (i = 1; i <= NSIG; ++i) {
        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
            sigaddset(&blocked_set, i);
            sighold(i);
        } else if (!sigismember(&set, i) && sigismember(&blocked_set, i)) {
            sigdelset(&blocked_set, i);
            sigrelse(i);
        }
    }
#  else  /* NO_SIGNAL_BLOCKING */
    int i;

    oset = blocked_set;
    for (i = 1; i < NSIG; ++i) {
        if (sigismember(&set, i) && !sigismember(&blocked_set, i)) {
            sigaddset(&blocked_set, i);
            signal_ignore(i);
        } else if (!sigismember(&set, i) && sigismember(&blocked_set, i)) {
            sigdelset(&blocked_set, i);
            install_handler(i);
        }
    }
#  endif /* SYSV_SIGNALS  */
# endif  /* BSD_SIGNALS   */
#endif   /* POSIX_SIGNALS */
 
    return oset;
}

#if defined(NO_SIGNAL_BLOCKING)
static int suspend_longjmp = 0;
static signal_jmp_buf suspend_jmp_buf;
#endif

/**/
int
signal_suspend(UNUSED(int sig), int wait_cmd)
{
    int ret;

#if defined(POSIX_SIGNALS) || defined(BSD_SIGNALS)
    sigset_t set;
# if defined(POSIX_SIGNALS) && defined(BROKEN_POSIX_SIGSUSPEND)
    sigset_t oset;
# endif

    sigemptyset(&set);

    /* SIGINT from the terminal driver needs to interrupt "wait"
     * and to cause traps to fire, but otherwise should not be
     * handled by the shell until after any foreground job has
     * a chance to decide whether to exit on that signal.
     */
    if (!(wait_cmd || isset(TRAPSASYNC) ||
	  (sigtrapped[SIGINT] & ~ZSIG_IGNORED)))
	sigaddset(&set, SIGINT);
#endif /* POSIX_SIGNALS || BSD_SIGNALS */

#ifdef POSIX_SIGNALS
# ifdef BROKEN_POSIX_SIGSUSPEND
    sigprocmask(SIG_SETMASK, &set, &oset);
    pause();
    sigprocmask(SIG_SETMASK, &oset, NULL);
# else /* not BROKEN_POSIX_SIGSUSPEND */
    ret = sigsuspend(&set);
# endif /* BROKEN_POSIX_SIGSUSPEND */
#else /* not POSIX_SIGNALS */
# ifdef BSD_SIGNALS
    ret = sigpause(set);
# else
#  ifdef SYSV_SIGNALS
    ret = sigpause(sig);

#  else  /* NO_SIGNAL_BLOCKING */
    /* need to use signal_longjmp to make this race-free *
     * between the child_unblock() and pause()           */
    if (signal_setjmp(suspend_jmp_buf) == 0) {
        suspend_longjmp = 1;   /* we want to signal_longjmp after catching signal */
        child_unblock();       /* do we need to do wait_cmd stuff as well?             */
        ret = pause();
    }
    suspend_longjmp = 0;       /* turn off using signal_longjmp since we are past *
                                * the pause() function.                           */
#  endif /* SYSV_SIGNALS  */
# endif  /* BSD_SIGNALS   */
#endif   /* POSIX_SIGNALS */

    return ret;
}

/* last signal we handled: race prone, or what? */
/**/
int last_signal;

/*
 * Wait for any processes that have changed state.
 *
 * The main use for this is in the SIGCHLD handler.  However,
 * we also use it to pick up status changes of jobs when
 * updating jobs.
 */
/**/
void
wait_for_processes(void)
{
    /* keep WAITING until no more child processes to reap */
    for (;;) {
	/* save the errno, since WAIT may change it */
	int old_errno = errno;
	int status;
	Job jn;
	Process pn;
	pid_t pid;
	pid_t *procsubpid = &cmdoutpid;
	int *procsubval = &cmdoutval;
	int cont = 0;
	struct execstack *es = exstack;

	/*
	 * Reap the child process.
	 * If we want usage information, we need to use wait3.
	 */
#if defined(HAVE_WAIT3) || defined(HAVE_WAITPID)
# ifdef WCONTINUED
# define WAITFLAGS (WNOHANG|WUNTRACED|WCONTINUED)
# else
# define WAITFLAGS (WNOHANG|WUNTRACED)
# endif
#endif
#ifdef HAVE_WAIT3
# ifdef HAVE_GETRUSAGE
	struct rusage ru;

	pid = wait3((void *)&status, WAITFLAGS, &ru);
# else
	pid = wait3((void *)&status, WAITFLAGS, NULL);
# endif
#else
# ifdef HAVE_WAITPID
	pid = waitpid(-1, &status, WAITFLAGS);
# else
	pid = wait(&status);
# endif
#endif

	if (!pid)  /* no more children to reap */
	    break;

	/* check if child returned was from process substitution */
	for (;;) {
	    if (pid == *procsubpid) {
		*procsubpid = 0;
		if (WIFSIGNALED(status))
		    *procsubval = (0200 | WTERMSIG(status));
		else
		    *procsubval = WEXITSTATUS(status);
		use_cmdoutval = 1;
		get_usage();
		cont = 1;
		break;
	    }
	    if (!es)
		break;
	    procsubpid = &es->cmdoutpid;
	    procsubval = &es->cmdoutval;
	    es = es->next;
	}
	if (cont)
	    continue;

	/* check for WAIT error */
	if (pid == -1) {
	    if (errno != ECHILD)
		zerr("wait failed: %e", errno);
	    /* WAIT changed errno, so restore the original */
	    errno = old_errno;
	    break;
	}

	/*
	 * Find the process and job containing this pid and
	 * update it.
	 */
	if (findproc(pid, &jn, &pn, 0)) {
#if defined(HAVE_WAIT3) && defined(HAVE_GETRUSAGE)
	    struct timezone dummy_tz;
	    gettimeofday(&pn->endtime, &dummy_tz);
	    pn->status = status;
	    pn->ti = ru;
#else
	    update_process(pn, status);
#endif
	    update_job(jn);
	} else if (findproc(pid, &jn, &pn, 1)) {
	    pn->status = status;
	    update_job(jn);
	} else {
	    /* If not found, update the shell record of time spent by
	     * children in sub processes anyway:  otherwise, this
	     * will get added on to the next found process that
	     * terminates.
	     */
	    get_usage();
	}
	/*
	 * Remember the status associated with $!, so we can
	 * wait for it even if it's exited.  This value is
	 * only used if we can't find the PID in the job table,
	 * so it doesn't matter that the value we save here isn't
	 * useful until the process has exited.
	 */
	if (pn != NULL && pid == lastpid && lastpid_status != -1L)
	    lastpid_status = lastval2;
    }
}

/* the signal handler */
 
/**/
mod_export RETSIGTYPE
zhandler(int sig)
{
    sigset_t newmask, oldmask;

#if defined(NO_SIGNAL_BLOCKING)
    int do_jump;
    signal_jmp_buf jump_to;
#endif
 
    last_signal = sig;
    signal_process(sig);
 
    sigfillset(&newmask);
    /* Block all signals temporarily           */
    oldmask = signal_block(newmask);
 
#if defined(NO_SIGNAL_BLOCKING)
    /* do we need to longjmp to signal_suspend */
    do_jump = suspend_longjmp;
    /* In case a SIGCHLD somehow arrives       */
    suspend_longjmp = 0;

    /* Traps can cause nested signal_suspend()  */
    if (sig == SIGCHLD) {
        if (do_jump) {
	    /* Copy suspend_jmp_buf                    */
            jump_to = suspend_jmp_buf;
	}
    }
#endif

    /* Are we queueing signals now?      */
    if (queueing_enabled) {
        int temp_rear = ++queue_rear % MAX_QUEUE_SIZE;

	DPUTS(temp_rear == queue_front, "BUG: signal queue full");
	/* Make sure it's not full (extremely unlikely) */
        if (temp_rear != queue_front) {
	    /* ok, not full, so add to queue   */
            queue_rear = temp_rear;
	    /* save signal caught              */
            signal_queue[queue_rear] = sig;
	    /* save current signal mask        */
            signal_mask_queue[queue_rear] = oldmask;
        }
        signal_reset(sig);
        return;
    }
 
    /* Reset signal mask, signal traps ok now */
    signal_setmask(oldmask);
 
    switch (sig) {
    case SIGCHLD:
	wait_for_processes();
        break;
 
    case SIGHUP:
        if (!handletrap(SIGHUP)) {
            stopmsg = 1;
            zexit(SIGHUP, 1);
        }
        break;
 
    case SIGINT:
        if (!handletrap(SIGINT)) {
	    if ((isset(PRIVILEGED) || isset(RESTRICTED)) &&
		isset(INTERACTIVE) && noerrexit < 0)
		zexit(SIGINT, 1);
            if (list_pipe || chline || simple_pline) {
                breaks = loops;
                errflag = 1;
		inerrflush();
		check_cursh_sig(SIGINT);
            }
        }
        break;

#ifdef SIGWINCH
    case SIGWINCH:
        adjustwinsize(1);  /* check window size and adjust */
	(void) handletrap(SIGWINCH);
        break;
#endif

    case SIGALRM:
        if (!handletrap(SIGALRM)) {
	    int idle = ttyidlegetfn(NULL);
	    int tmout = getiparam("TMOUT");
	    if (idle >= 0 && idle < tmout)
		alarm(tmout - idle);
	    else {
		errflag = noerrs = 0;
		zwarn("timeout");
		stopmsg = 1;
		zexit(SIGALRM, 1);
	    }
        }
        break;
 
    default:
        (void) handletrap(sig);
        break;
    }   /* end of switch(sig) */
 
    signal_reset(sig);

/* This is used to make signal_suspend() race-free */
#if defined(NO_SIGNAL_BLOCKING)
    if (do_jump)
        signal_longjmp(jump_to, 1);
#endif

} /* handler */

 
/* SIGHUP any jobs left running */
 
/**/
void
killrunjobs(int from_signal)
{
    int i, killed = 0;
 
    if (unset(HUP))
        return;
    for (i = 1; i <= maxjob; i++)
        if ((from_signal || i != thisjob) && (jobtab[i].stat & STAT_LOCKED) &&
            !(jobtab[i].stat & STAT_NOPRINT) &&
            !(jobtab[i].stat & STAT_STOPPED)) {
            if (jobtab[i].gleader != getpid() &&
		killpg(jobtab[i].gleader, SIGHUP) != -1)
                killed++;
        }
    if (killed)
        zwarn("warning: %d jobs SIGHUPed", killed);
}


/* send a signal to a job (simply involves kill if monitoring is on) */
 
/**/
int
killjb(Job jn, int sig)
{
    Process pn;
    int err = 0;
 
    if (jobbing) {
        if (jn->stat & STAT_SUPERJOB) {
            if (sig == SIGCONT) {
                for (pn = jobtab[jn->other].procs; pn; pn = pn->next)
                    if (killpg(pn->pid, sig) == -1)
			if (kill(pn->pid, sig) == -1 && errno != ESRCH)
			    err = -1;
 
                for (pn = jn->procs; pn->next; pn = pn->next)
                    if (kill(pn->pid, sig) == -1 && errno != ESRCH)
			err = -1;

		if (!jobtab[jn->other].procs && pn)
		    if (kill(pn->pid, sig) == -1 && errno != ESRCH)
			err = -1;

                return err;
            }
            if (killpg(jobtab[jn->other].gleader, sig) == -1 && errno != ESRCH)
		err = -1;
		
	    if (killpg(jn->gleader, sig) == -1 && errno != ESRCH)
		err = -1;

	    return err;
        }
        else
	    return killpg(jn->gleader, sig);
    }
    for (pn = jn->procs; pn; pn = pn->next)
        if ((err = kill(pn->pid, sig)) == -1 && errno != ESRCH && sig != 0)
            return -1;
    return err;
}

/*
 * List for saving traps.  We don't usually have that many traps
 * at once, so just use a linked list.
 */
struct savetrap {
    int sig, flags, local;
    void *list;
};

static LinkList savetraps;
static int dontsavetrap;

/*
 * Save the current trap by copying it.  This does nothing to
 * the existing value of sigtrapped or siglists.
 */

static void
dosavetrap(int sig, int level)
{
    struct savetrap *st;
    st = (struct savetrap *)zalloc(sizeof(*st));
    st->sig = sig;
    st->local = level;
    if ((st->flags = sigtrapped[sig]) & ZSIG_FUNC) {
	/*
	 * Get the old function: this assumes we haven't added
	 * the new one yet.
	 */
	Shfunc shf, newshf = NULL;
	if ((shf = (Shfunc)gettrapnode(sig, 1))) {
	    /* Copy the node for saving */
	    newshf = (Shfunc) zalloc(sizeof(*newshf));
	    newshf->node.nam = ztrdup(shf->node.nam);
	    newshf->node.flags = shf->node.flags;
	    newshf->funcdef = dupeprog(shf->funcdef, 0);
	    newshf->filename = ztrdup(shf->filename);
	    newshf->emulation = shf->emulation;
	    if (shf->node.flags & PM_UNDEFINED)
		newshf->funcdef->shf = newshf;
	}
#ifdef DEBUG
	else dputs("BUG: no function present with function trap flag set.");
#endif
	DPUTS(siglists[sig], "BUG: function signal has eval list, too.");
	st->list = newshf;
    } else if (sigtrapped[sig]) {
	st->list = siglists[sig] ? dupeprog(siglists[sig], 0) : NULL;
    } else {
	DPUTS(siglists[sig], "BUG: siglists not null for untrapped signal");
	st->list = NULL;
    }
    if (!savetraps)
	savetraps = znewlinklist();
    /*
     * Put this at the front of the list
     */
    zinsertlinknode(savetraps, (LinkNode)savetraps, st);
}


/*
 * Set a trap:  note this does not handle manipulation of
 * the function table for TRAPNAL functions.
 *
 * sig is the signal number.
 *
 * l is the list to be eval'd for a trap defined with the "trap"
 * builtin and should be NULL for a function trap.
 *
 * flags includes any additional flags to be or'd into sigtrapped[sig],
 * in particular ZSIG_FUNC; the basic flags will be assigned within
 * settrap.
 */

/**/
mod_export int
settrap(int sig, Eprog l, int flags)
{
    if (sig == -1)
        return 1;
    if (jobbing && (sig == SIGTTOU || sig == SIGTSTP || sig == SIGTTIN)) {
        zerr("can't trap SIG%s in interactive shells", sigs[sig]);
        return 1;
    }

    /*
     * Call unsettrap() unconditionally, to make sure trap is saved
     * if necessary.
     */
    queue_signals();
    unsettrap(sig);

    DPUTS((flags & ZSIG_FUNC) && l,
	  "BUG: trap function has passed eval list, too");
    siglists[sig] = l;
    if (!(flags & ZSIG_FUNC) && empty_eprog(l)) {
	sigtrapped[sig] = ZSIG_IGNORED;
        if (sig && sig <= SIGCOUNT &&
#ifdef SIGWINCH
            sig != SIGWINCH &&
#endif
            sig != SIGCHLD)
            signal_ignore(sig);
    } else {
	nsigtrapped++;
        sigtrapped[sig] = ZSIG_TRAPPED;
        if (sig && sig <= SIGCOUNT &&
#ifdef SIGWINCH
            sig != SIGWINCH &&
#endif
            sig != SIGCHLD)
            install_handler(sig);
    }
    /*
     * Note that introducing the locallevel does not affect whether
     * sigtrapped[sig] is zero or not, i.e. a test without a mask
     * works just the same.
     */
    sigtrapped[sig] |= (locallevel << ZSIG_SHIFT) | flags;
    unqueue_signals();
    return 0;
}

/**/
void
unsettrap(int sig)
{
    HashNode hn;

    queue_signals();
    hn = removetrap(sig);
    if (hn)
	shfunctab->freenode(hn);
    unqueue_signals();
}

/**/
HashNode
removetrap(int sig)
{
    int trapped;

    if (sig == -1 ||
	(jobbing && (sig == SIGTTOU || sig == SIGTSTP || sig == SIGTTIN)))
	return NULL;

    queue_signals();
    trapped = sigtrapped[sig];
    /*
     * Note that we save the trap here even if there isn't an existing
     * one, to aid in removing this one.  However, if there's
     * already one at the current locallevel we just overwrite it.
     */
    if (!dontsavetrap &&
	(sig == SIGEXIT ? !isset(POSIXTRAPS) : isset(LOCALTRAPS)) &&
	locallevel &&
	(!trapped || locallevel > (sigtrapped[sig] >> ZSIG_SHIFT)))
	dosavetrap(sig, locallevel);

    if (!trapped) {
	unqueue_signals();
        return NULL;
    }
    if (sigtrapped[sig] & ZSIG_TRAPPED)
	nsigtrapped--;
    sigtrapped[sig] = 0;
    if (sig == SIGINT && interact) {
	/* PWS 1995/05/16:  added test for interactive, also noholdintr() *
	 * as subshells ignoring SIGINT have it blocked from delivery     */
        intr();
	noholdintr();
    } else if (sig == SIGHUP)
        install_handler(sig);
    else if (sig && sig <= SIGCOUNT &&
#ifdef SIGWINCH
             sig != SIGWINCH &&
#endif
             sig != SIGCHLD)
        signal_default(sig);

    /*
     * At this point we free the appropriate structs.  If we don't
     * want that to happen then either the function should already have been
     * removed from shfunctab, or the entry in siglists should have been set
     * to NULL.  This is no longer necessary for saving traps as that
     * copies the structures, so here we are remove the originals.
     * That causes a little inefficiency, but a good deal more reliability.
     */
    if (trapped & ZSIG_FUNC) {
	HashNode node = gettrapnode(sig, 1);

	/*
	 * As in dosavetrap(), don't call removeshfuncnode() because
	 * that calls back into unsettrap();
	 */
	if (node)
	    removehashnode(shfunctab, node->nam);
	unqueue_signals();

	return node;
    } else if (siglists[sig]) {
	freeeprog(siglists[sig]);
	siglists[sig] = NULL;
    }
    unqueue_signals();

    return NULL;
}

/**/
void
starttrapscope(void)
{
    /* No special SIGEXIT behaviour inside another trap. */
    if (intrap)
	return;

    /*
     * SIGEXIT needs to be restored at the current locallevel,
     * so give it the next higher one. dosavetrap() is called
     * automatically where necessary.
     */
    if (sigtrapped[SIGEXIT] && !isset(POSIXTRAPS)) {
	locallevel++;
	unsettrap(SIGEXIT);
	locallevel--;
    }
}

/*
 * Reset traps after the end of a function: must be called after
 * endparamscope() so that the locallevel has been decremented.
 */

/**/
void
endtrapscope(void)
{
    LinkNode ln;
    struct savetrap *st;
    int exittr = 0;
    void *exitfn = NULL;

    /*
     * Remember the exit trap, but don't run it until
     * after all the other traps have been put back.
     * Don't do this inside another trap.
     */
    if (!intrap &&
	!isset(POSIXTRAPS) && (exittr = sigtrapped[SIGEXIT])) {
	if (exittr & ZSIG_FUNC) {
	    exitfn = removehashnode(shfunctab, "TRAPEXIT");
	} else {
	    exitfn = siglists[SIGEXIT];
	    siglists[SIGEXIT] = NULL;
	}
	if (sigtrapped[SIGEXIT] & ZSIG_TRAPPED)
	    nsigtrapped--;
	sigtrapped[SIGEXIT] = 0;
    }

    if (savetraps) {
	while ((ln = firstnode(savetraps)) &&
	       (st = (struct savetrap *) ln->dat) &&
	       st->local > locallevel) {
	    int sig = st->sig;

	    remnode(savetraps, ln);

	    if (st->flags && (st->list != NULL)) {
		/* prevent settrap from saving this */
		dontsavetrap++;
		if (st->flags & ZSIG_FUNC)
		    settrap(sig, NULL, ZSIG_FUNC);
		else
		    settrap(sig, (Eprog) st->list, 0);
		dontsavetrap--;
		/*
		 * counting of nsigtrapped should presumably be handled
		 * in settrap...
		 */
		DPUTS((sigtrapped[sig] ^ st->flags) & ZSIG_TRAPPED,
		      "BUG: settrap didn't restore correct ZSIG_TRAPPED");
		if ((sigtrapped[sig] = st->flags) & ZSIG_FUNC)
		    shfunctab->addnode(shfunctab, ((Shfunc)st->list)->node.nam,
				       (Shfunc) st->list);
	    } else if (sigtrapped[sig])
		unsettrap(sig);

	    zfree(st, sizeof(*st));
	}
    }

    if (exittr) {
	if (!isset(POSIXTRAPS))
	    dotrapargs(SIGEXIT, &exittr, exitfn);
	if (exittr & ZSIG_FUNC)
	    shfunctab->freenode((HashNode)exitfn);
	else
	    freeeprog(exitfn);
    }
    DPUTS(!locallevel && savetraps && firstnode(savetraps),
	  "BUG: still saved traps outside all function scope");
}


/*
 * Decide whether a trap needs handling.
 * If so, see if the trap should be run now or queued.
 * Return 1 if the trap has been or will be handled.
 * This only needs to be called in place of dotrap() in the
 * signal handler, since it's only while waiting for children
 * to exit that we queue traps.
 */
/**/
static int
handletrap(int sig)
{
    if (!sigtrapped[sig])
	return 0;

    if (trap_queueing_enabled)
    {
	/* Code borrowed from signal queueing */
	int temp_rear = ++trap_queue_rear % MAX_QUEUE_SIZE;

	DPUTS(temp_rear == trap_queue_front, "BUG: trap queue full");
	/* If queue is not full... */
	if (temp_rear != trap_queue_front) {
	    trap_queue_rear = temp_rear;
	    trap_queue[trap_queue_rear] = sig;
	}
	return 1;
    }

    dotrap(sig);

    if (sig == SIGALRM)
    {
	int tmout;
	/*
	 * Reset the alarm.
	 * It seems slightly more natural to do this when the
	 * trap is run, rather than when it's queued, since
	 * the user doesn't see the latter.
	 */
	if ((tmout = getiparam("TMOUT")))
	    alarm(tmout);
    }

    return 1;
}


/*
 * Queue traps if they shouldn't be run asynchronously, i.e.
 * we're not in the wait builtin and TRAPSASYNC isn't set, when
 * waiting for children to exit.
 *
 * Note that unlike signal queuing this should only be called
 * in single matching pairs and can't be nested.  It is
 * only needed when waiting for a job or process to finish.
 *
 * There is presumably a race setting this up: we shouldn't be running
 * traps between forking a foreground process and this point, either.
 */
/**/
void
queue_traps(int wait_cmd)
{
    if (!isset(TRAPSASYNC) && !wait_cmd) {
	/*
	 * Traps need to be handled synchronously, so
	 * enable queueing.
	 */
	trap_queueing_enabled = 1;
    }
}


/*
 * Disable trap queuing and run the traps.
 */
/**/
void
unqueue_traps(void)
{
    trap_queueing_enabled = 0;
    while (trap_queue_front != trap_queue_rear) {
	trap_queue_front = (trap_queue_front + 1) % MAX_QUEUE_SIZE;
	(void) handletrap(trap_queue[trap_queue_front]);
    }
}


/* Execute a trap function for a given signal, possibly
 * with non-standard sigtrapped & siglists values
 */

/* Are we already executing a trap? */
/**/
int intrap;

/* Is the current trap a function? */

/**/
int trapisfunc;

/*
 * If the current trap is not a function, at what function depth
 * did the trap get called?
 */
/**/
int traplocallevel;

/*
 * sig is the signal number.
 * *sigtr is the value to be taken as the field in sigtrapped (since
 *   that may have changed by this point if we are exiting).
 * sigfn is an Eprog with a non-function eval list, or a Shfunc
 *   with a function trap.  It may be NULL with an ignored signal.
 */

/**/
static void
dotrapargs(int sig, int *sigtr, void *sigfn)
{
    LinkList args;
    char *name, num[4];
    int obreaks = breaks;
    int oretflag = retflag;
    int isfunc;
    int traperr, new_trap_state, new_trap_return;

    /* if signal is being ignored or the trap function		      *
     * is NULL, then return					      *
     *								      *
     * Also return if errflag is set.  In fact, the code in the       *
     * function will test for this, but this way we keep status flags *
     * intact without working too hard.  Special cases (e.g. calling  *
     * a trap for SIGINT after the error flag was set) are handled    *
     * by the calling code.  (PWS 1995/06/08).			      *
     *                                                                *
     * This test is now replicated in dotrap().                       */
    if ((*sigtr & ZSIG_IGNORED) || !sigfn || errflag)
        return;

    /*
     * Never execute special (synchronous) traps inside other traps.
     * This can cause unexpected code execution when more than one
     * of these is set.
     *
     * The down side is that it's harder to debug traps.  I don't think
     * that's a big issue.
     */
    if (intrap) {
	switch (sig) {
	case SIGEXIT:
	case SIGDEBUG:
	case SIGZERR:
	    return;
	}
    }

    intrap++;
    *sigtr |= ZSIG_IGNORED;

    lexsave();
    /* execsave will save the old trap_return and trap_state */
    execsave();
    breaks = retflag = 0;
    traplocallevel = locallevel;
    runhookdef(BEFORETRAPHOOK, NULL);
    if (*sigtr & ZSIG_FUNC) {
	int osc = sfcontext, old_incompfunc = incompfunc;
	HashNode hn = gettrapnode(sig, 0);

	args = znewlinklist();
	/*
	 * In case of multiple names, try to get
	 * a hint of the name in use from the function table.
	 * In special cases, e.g. EXIT traps, the function
	 * has already been removed.  Then it's OK to
	 * use the standard name.
	 */
	if (hn) {
	    name = ztrdup(hn->nam);
	} else {
	    name = (char *) zalloc(5 + strlen(sigs[sig]));
	    sprintf(name, "TRAP%s", sigs[sig]);
	}
	zaddlinknode(args, name);
	sprintf(num, "%d", sig);
	zaddlinknode(args, num);

	trap_return = -1;	/* incremented by doshfunc */
	trap_state = TRAP_STATE_PRIMED;
	trapisfunc = isfunc = 1;

	sfcontext = SFC_SIGNAL;
	incompfunc = 0;
	doshfunc((Shfunc)sigfn, args, 1);
	sfcontext = osc;
	incompfunc= old_incompfunc;
	freelinklist(args, (FreeFunc) NULL);
	zsfree(name);
    } else {
	trap_return = -2;	/* not incremented, used at current level */
	trap_state = TRAP_STATE_PRIMED;
	trapisfunc = isfunc = 0;

	execode((Eprog)sigfn, 1, 0, "trap");
    }
    runhookdef(AFTERTRAPHOOK, NULL);

    traperr = errflag;

    /* Grab values before they are restored */
    new_trap_state = trap_state;
    new_trap_return = trap_return;

    execrestore();
    lexrestore();

    if (new_trap_state == TRAP_STATE_FORCE_RETURN &&
	/* zero return from function isn't special */
	!(isfunc && new_trap_return == 0)) {
	if (isfunc) {
	    breaks = loops;
	    errflag = 1;
	}
	lastval = new_trap_return;
	/* return triggered */
	retflag = 1;
    } else {
	if (traperr && !EMULATION(EMULATE_SH))
	    lastval = 1;
	if (try_tryflag)
	    errflag = traperr;
	breaks += obreaks;
	/* return not triggered: restore old flag */
	retflag = oretflag;
	if (breaks > loops)
	    breaks = loops;
    }

    /*
     * If zle was running while the trap was executed, see if we
     * need to restore the display.
     */
    if (zleactive && resetneeded)
	zleentry(ZLE_CMD_REFRESH);

    if (*sigtr != ZSIG_IGNORED)
	*sigtr &= ~ZSIG_IGNORED;
    intrap--;
}

/* Standard call to execute a trap for a given signal. */

/**/
void
dotrap(int sig)
{
    void *funcprog;

    if (sigtrapped[sig] & ZSIG_FUNC) {
	HashNode hn = gettrapnode(sig, 0);
	if (hn)
	    funcprog = hn;
	else {
#ifdef DEBUG
	    dputs("BUG: running function trap which has escaped.");
#endif
	    funcprog = NULL;
	}
    } else
	funcprog = siglists[sig];

    /*
     * Copied from dotrapargs().
     * (In fact, the gain from duplicating this appears to be virtually
     * zero.  Not sure why it's here.)
     */
    if ((sigtrapped[sig] & ZSIG_IGNORED) || !funcprog || errflag)
	return;

    dotrapargs(sig, sigtrapped+sig, funcprog);
}