1 /* Extended support for using signal values.
2 Written by Fred Fish. fnf@cygnus.com
3 This file is in the public domain. */
4
5 #include "config.h"
6 #include "ansidecl.h"
7 #include "libiberty.h"
8
9 /* We need to declare sys_siglist, because even if the system provides
10 it we can't assume that it is declared in <signal.h> (for example,
11 SunOS provides sys_siglist, but it does not declare it in any
12 header file). However, we can't declare sys_siglist portably,
13 because on some systems it is declared with const and on some
14 systems it is declared without const. If we were using autoconf,
15 we could work out the right declaration. Until, then we just
16 ignore any declaration in the system header files, and always
17 declare it ourselves. With luck, this will always work. */
18 #define sys_siglist no_such_symbol
19 #define sys_nsig sys_nsig__no_such_symbol
20
21 #include <stdio.h>
22 #include <signal.h>
23
24 /* Routines imported from standard C runtime libraries. */
25
26 #ifdef HAVE_STDLIB_H
27 #include <stdlib.h>
28 #else
29 extern void *malloc ();
30 #endif
31
32 #ifdef HAVE_STRING_H
33 #include <string.h>
34 #else
35 extern void *memset ();
36 #endif
37
38 /* Undefine the macro we used to hide the definition of sys_siglist
39 found in the system header files. */
40 #undef sys_siglist
41 #undef sys_nsig
42
43 #ifndef NULL
44 # define NULL (void *) 0
45 #endif
46
47 #ifndef MAX
48 # define MAX(a,b) ((a) > (b) ? (a) : (b))
49 #endif
50
51 static void init_signal_tables (void);
52
53 /* Translation table for signal values.
54
55 Note that this table is generally only accessed when it is used at runtime
56 to initialize signal name and message tables that are indexed by signal
57 value.
58
59 Not all of these signals will exist on all systems. This table is the only
60 thing that should have to be updated as new signal numbers are introduced.
61 It's sort of ugly, but at least its portable. */
62
63 struct signal_info
64 {
65 const int value; /* The numeric value from <signal.h> */
66 const char *const name; /* The equivalent symbolic value */
67 #ifndef HAVE_SYS_SIGLIST
68 const char *const msg; /* Short message about this value */
69 #endif
70 };
71
72 #ifndef HAVE_SYS_SIGLIST
73 # define ENTRY(value, name, msg) {value, name, msg}
74 #else
75 # define ENTRY(value, name, msg) {value, name}
76 #endif
77
78 static const struct signal_info signal_table[] =
79 {
80 #if defined (SIGHUP)
81 ENTRY(SIGHUP, "SIGHUP", "Hangup"),
82 #endif
83 #if defined (SIGINT)
84 ENTRY(SIGINT, "SIGINT", "Interrupt"),
85 #endif
86 #if defined (SIGQUIT)
87 ENTRY(SIGQUIT, "SIGQUIT", "Quit"),
88 #endif
89 #if defined (SIGILL)
90 ENTRY(SIGILL, "SIGILL", "Illegal instruction"),
91 #endif
92 #if defined (SIGTRAP)
93 ENTRY(SIGTRAP, "SIGTRAP", "Trace/breakpoint trap"),
94 #endif
95 /* Put SIGIOT before SIGABRT, so that if SIGIOT==SIGABRT then SIGABRT
96 overrides SIGIOT. SIGABRT is in ANSI and POSIX.1, and SIGIOT isn't. */
97 #if defined (SIGIOT)
98 ENTRY(SIGIOT, "SIGIOT", "IOT trap"),
99 #endif
100 #if defined (SIGABRT)
101 ENTRY(SIGABRT, "SIGABRT", "Aborted"),
102 #endif
103 #if defined (SIGEMT)
104 ENTRY(SIGEMT, "SIGEMT", "Emulation trap"),
105 #endif
106 #if defined (SIGFPE)
107 ENTRY(SIGFPE, "SIGFPE", "Arithmetic exception"),
108 #endif
109 #if defined (SIGKILL)
110 ENTRY(SIGKILL, "SIGKILL", "Killed"),
111 #endif
112 #if defined (SIGBUS)
113 ENTRY(SIGBUS, "SIGBUS", "Bus error"),
114 #endif
115 #if defined (SIGSEGV)
116 ENTRY(SIGSEGV, "SIGSEGV", "Segmentation fault"),
117 #endif
118 #if defined (SIGSYS)
119 ENTRY(SIGSYS, "SIGSYS", "Bad system call"),
120 #endif
121 #if defined (SIGPIPE)
122 ENTRY(SIGPIPE, "SIGPIPE", "Broken pipe"),
123 #endif
124 #if defined (SIGALRM)
125 ENTRY(SIGALRM, "SIGALRM", "Alarm clock"),
126 #endif
127 #if defined (SIGTERM)
128 ENTRY(SIGTERM, "SIGTERM", "Terminated"),
129 #endif
130 #if defined (SIGUSR1)
131 ENTRY(SIGUSR1, "SIGUSR1", "User defined signal 1"),
132 #endif
133 #if defined (SIGUSR2)
134 ENTRY(SIGUSR2, "SIGUSR2", "User defined signal 2"),
135 #endif
136 /* Put SIGCLD before SIGCHLD, so that if SIGCLD==SIGCHLD then SIGCHLD
137 overrides SIGCLD. SIGCHLD is in POXIX.1 */
138 #if defined (SIGCLD)
139 ENTRY(SIGCLD, "SIGCLD", "Child status changed"),
140 #endif
141 #if defined (SIGCHLD)
142 ENTRY(SIGCHLD, "SIGCHLD", "Child status changed"),
143 #endif
144 #if defined (SIGPWR)
145 ENTRY(SIGPWR, "SIGPWR", "Power fail/restart"),
146 #endif
147 #if defined (SIGWINCH)
148 ENTRY(SIGWINCH, "SIGWINCH", "Window size changed"),
149 #endif
150 #if defined (SIGURG)
151 ENTRY(SIGURG, "SIGURG", "Urgent I/O condition"),
152 #endif
153 #if defined (SIGIO)
154 /* "I/O pending" has also been suggested, but is misleading since the
155 signal only happens when the process has asked for it, not everytime
156 I/O is pending. */
157 ENTRY(SIGIO, "SIGIO", "I/O possible"),
158 #endif
159 #if defined (SIGPOLL)
160 ENTRY(SIGPOLL, "SIGPOLL", "Pollable event occurred"),
161 #endif
162 #if defined (SIGSTOP)
163 ENTRY(SIGSTOP, "SIGSTOP", "Stopped (signal)"),
164 #endif
165 #if defined (SIGTSTP)
166 ENTRY(SIGTSTP, "SIGTSTP", "Stopped (user)"),
167 #endif
168 #if defined (SIGCONT)
169 ENTRY(SIGCONT, "SIGCONT", "Continued"),
170 #endif
171 #if defined (SIGTTIN)
172 ENTRY(SIGTTIN, "SIGTTIN", "Stopped (tty input)"),
173 #endif
174 #if defined (SIGTTOU)
175 ENTRY(SIGTTOU, "SIGTTOU", "Stopped (tty output)"),
176 #endif
177 #if defined (SIGVTALRM)
178 ENTRY(SIGVTALRM, "SIGVTALRM", "Virtual timer expired"),
179 #endif
180 #if defined (SIGPROF)
181 ENTRY(SIGPROF, "SIGPROF", "Profiling timer expired"),
182 #endif
183 #if defined (SIGXCPU)
184 ENTRY(SIGXCPU, "SIGXCPU", "CPU time limit exceeded"),
185 #endif
186 #if defined (SIGXFSZ)
187 ENTRY(SIGXFSZ, "SIGXFSZ", "File size limit exceeded"),
188 #endif
189 #if defined (SIGWIND)
190 ENTRY(SIGWIND, "SIGWIND", "SIGWIND"),
191 #endif
192 #if defined (SIGPHONE)
193 ENTRY(SIGPHONE, "SIGPHONE", "SIGPHONE"),
194 #endif
195 #if defined (SIGLOST)
196 ENTRY(SIGLOST, "SIGLOST", "Resource lost"),
197 #endif
198 #if defined (SIGWAITING)
199 ENTRY(SIGWAITING, "SIGWAITING", "Process's LWPs are blocked"),
200 #endif
201 #if defined (SIGLWP)
202 ENTRY(SIGLWP, "SIGLWP", "Signal LWP"),
203 #endif
204 #if defined (SIGDANGER)
205 ENTRY(SIGDANGER, "SIGDANGER", "Swap space dangerously low"),
206 #endif
207 #if defined (SIGGRANT)
208 ENTRY(SIGGRANT, "SIGGRANT", "Monitor mode granted"),
209 #endif
210 #if defined (SIGRETRACT)
211 ENTRY(SIGRETRACT, "SIGRETRACT", "Need to relinguish monitor mode"),
212 #endif
213 #if defined (SIGMSG)
214 ENTRY(SIGMSG, "SIGMSG", "Monitor mode data available"),
215 #endif
216 #if defined (SIGSOUND)
217 ENTRY(SIGSOUND, "SIGSOUND", "Sound completed"),
218 #endif
219 #if defined (SIGSAK)
220 ENTRY(SIGSAK, "SIGSAK", "Secure attention"),
221 #endif
222 ENTRY(0, NULL, NULL)
223 };
224
225 /* Translation table allocated and initialized at runtime. Indexed by the
226 signal value to find the equivalent symbolic value. */
227
228 static const char **signal_names;
229 static int num_signal_names = 0;
230
231 /* Translation table allocated and initialized at runtime, if it does not
232 already exist in the host environment. Indexed by the signal value to find
233 the descriptive string.
234
235 We don't export it for use in other modules because even though it has the
236 same name, it differs from other implementations in that it is dynamically
237 initialized rather than statically initialized. */
238
239 #ifndef HAVE_SYS_SIGLIST
240
241 static int sys_nsig;
242 static const char **sys_siglist;
243
244 #else
245
246 #ifdef NSIG
247 static int sys_nsig = NSIG;
248 #else
249 #ifdef _NSIG
250 static int sys_nsig = _NSIG;
251 #endif
252 #endif
253 extern const char * const sys_siglist[];
254
255 #endif
256
257
258 /*
259
260 NAME
261
262 init_signal_tables -- initialize the name and message tables
263
264 SYNOPSIS
265
266 static void init_signal_tables ();
267
268 DESCRIPTION
269
270 Using the signal_table, which is initialized at compile time, generate
271 the signal_names and the sys_siglist (if needed) tables, which are
272 indexed at runtime by a specific signal value.
273
274 BUGS
275
276 The initialization of the tables may fail under low memory conditions,
277 in which case we don't do anything particularly useful, but we don't
278 bomb either. Who knows, it might succeed at a later point if we free
279 some memory in the meantime. In any case, the other routines know
280 how to deal with lack of a table after trying to initialize it. This
281 may or may not be considered to be a bug, that we don't specifically
282 warn about this particular failure mode.
283
284 */
285
286 static void
287 init_signal_tables (void)
288 {
289 const struct signal_info *eip;
290 int nbytes;
291
292 /* If we haven't already scanned the signal_table once to find the maximum
293 signal value, then go find it now. */
294
295 if (num_signal_names == 0)
296 {
297 for (eip = signal_table; eip -> name != NULL; eip++)
298 {
299 if (eip -> value >= num_signal_names)
300 {
301 num_signal_names = eip -> value + 1;
302 }
303 }
304 }
305
306 /* Now attempt to allocate the signal_names table, zero it out, and then
307 initialize it from the statically initialized signal_table. */
308
309 if (signal_names == NULL)
310 {
311 nbytes = num_signal_names * sizeof (char *);
312 if ((signal_names = (const char **) malloc (nbytes)) != NULL)
313 {
314 memset (signal_names, 0, nbytes);
315 for (eip = signal_table; eip -> name != NULL; eip++)
316 {
317 signal_names[eip -> value] = eip -> name;
318 }
319 }
320 }
321
322 #ifndef HAVE_SYS_SIGLIST
323
324 /* Now attempt to allocate the sys_siglist table, zero it out, and then
325 initialize it from the statically initialized signal_table. */
326
327 if (sys_siglist == NULL)
328 {
329 nbytes = num_signal_names * sizeof (char *);
330 if ((sys_siglist = (const char **) malloc (nbytes)) != NULL)
331 {
332 memset (sys_siglist, 0, nbytes);
333 sys_nsig = num_signal_names;
334 for (eip = signal_table; eip -> name != NULL; eip++)
335 {
336 sys_siglist[eip -> value] = eip -> msg;
337 }
338 }
339 }
340
341 #endif
342
343 }
344
345
346 /*
347
348 @deftypefn Extension int signo_max (void)
349
350 Returns the maximum signal value for which a corresponding symbolic
351 name or message is available. Note that in the case where we use the
352 @code{sys_siglist} supplied by the system, it is possible for there to
353 be more symbolic names than messages, or vice versa. In fact, the
354 manual page for @code{psignal(3b)} explicitly warns that one should
355 check the size of the table (@code{NSIG}) before indexing it, since
356 new signal codes may be added to the system before they are added to
357 the table. Thus @code{NSIG} might be smaller than value implied by
358 the largest signo value defined in @code{<signal.h>}.
359
360 We return the maximum value that can be used to obtain a meaningful
361 symbolic name or message.
362
363 @end deftypefn
364
365 */
366
367 int
368 signo_max (void)
369 {
370 int maxsize;
371
372 if (signal_names == NULL)
373 {
374 init_signal_tables ();
375 }
376 maxsize = MAX (sys_nsig, num_signal_names);
377 return (maxsize - 1);
378 }
379
380
381 /*
382
383 @deftypefn Supplemental {const char *} strsignal (int @var{signo})
384
385 Maps an signal number to an signal message string, the contents of
386 which are implementation defined. On systems which have the external
387 variable @code{sys_siglist}, these strings will be the same as the
388 ones used by @code{psignal()}.
389
390 If the supplied signal number is within the valid range of indices for
391 the @code{sys_siglist}, but no message is available for the particular
392 signal number, then returns the string @samp{Signal @var{num}}, where
393 @var{num} is the signal number.
394
395 If the supplied signal number is not a valid index into
396 @code{sys_siglist}, returns @code{NULL}.
397
398 The returned string is only guaranteed to be valid only until the next
399 call to @code{strsignal}.
400
401 @end deftypefn
402
403 */
404
405 #ifndef HAVE_STRSIGNAL
406
407 char *
408 strsignal (int signo)
409 {
410 char *msg;
411 static char buf[32];
412
413 #ifndef HAVE_SYS_SIGLIST
414
415 if (signal_names == NULL)
416 {
417 init_signal_tables ();
418 }
419
420 #endif
421
422 if ((signo < 0) || (signo >= sys_nsig))
423 {
424 /* Out of range, just return NULL */
425 msg = NULL;
426 }
427 else if ((sys_siglist == NULL) || (sys_siglist[signo] == NULL))
428 {
429 /* In range, but no sys_siglist or no entry at this index. */
430 sprintf (buf, "Signal %d", signo);
431 msg = buf;
432 }
433 else
434 {
435 /* In range, and a valid message. Just return the message. We
436 can safely cast away const, since POSIX says the user must
437 not modify the result. */
438 msg = (char *) sys_siglist[signo];
439 }
440
441 return (msg);
442 }
443
444 #endif /* ! HAVE_STRSIGNAL */
445
446 /*
447
448 @deftypefn Extension {const char*} strsigno (int @var{signo})
449
450 Given an signal number, returns a pointer to a string containing the
451 symbolic name of that signal number, as found in @code{<signal.h>}.
452
453 If the supplied signal number is within the valid range of indices for
454 symbolic names, but no name is available for the particular signal
455 number, then returns the string @samp{Signal @var{num}}, where
456 @var{num} is the signal number.
457
458 If the supplied signal number is not within the range of valid
459 indices, then returns @code{NULL}.
460
461 The contents of the location pointed to are only guaranteed to be
462 valid until the next call to @code{strsigno}.
463
464 @end deftypefn
465
466 */
467
468 const char *
469 strsigno (int signo)
470 {
471 const char *name;
472 static char buf[32];
473
474 if (signal_names == NULL)
475 {
476 init_signal_tables ();
477 }
478
479 if ((signo < 0) || (signo >= num_signal_names))
480 {
481 /* Out of range, just return NULL */
482 name = NULL;
483 }
484 else if ((signal_names == NULL) || (signal_names[signo] == NULL))
485 {
486 /* In range, but no signal_names or no entry at this index. */
487 sprintf (buf, "Signal %d", signo);
488 name = (const char *) buf;
489 }
490 else
491 {
492 /* In range, and a valid name. Just return the name. */
493 name = signal_names[signo];
494 }
495
496 return (name);
497 }
498
499
500 /*
501
502 @deftypefn Extension int strtosigno (const char *@var{name})
503
504 Given the symbolic name of a signal, map it to a signal number. If no
505 translation is found, returns 0.
506
507 @end deftypefn
508
509 */
510
511 int
512 strtosigno (const char *name)
513 {
514 int signo = 0;
515
516 if (name != NULL)
517 {
518 if (signal_names == NULL)
519 {
520 init_signal_tables ();
521 }
522 for (signo = 0; signo < num_signal_names; signo++)
523 {
524 if ((signal_names[signo] != NULL) &&
525 (strcmp (name, signal_names[signo]) == 0))
526 {
527 break;
528 }
529 }
530 if (signo == num_signal_names)
531 {
532 signo = 0;
533 }
534 }
535 return (signo);
536 }
537
538
539 /*
540
541 @deftypefn Supplemental void psignal (int @var{signo}, char *@var{message})
542
543 Print @var{message} to the standard error, followed by a colon,
544 followed by the description of the signal specified by @var{signo},
545 followed by a newline.
546
547 @end deftypefn
548
549 */
550
551 #ifndef HAVE_PSIGNAL
552
553 void
554 psignal (int signo, char *message)
555 {
556 if (signal_names == NULL)
557 {
558 init_signal_tables ();
559 }
560 if ((signo <= 0) || (signo >= sys_nsig))
561 {
562 fprintf (stderr, "%s: unknown signal\n", message);
563 }
564 else
565 {
566 fprintf (stderr, "%s: %s\n", message, sys_siglist[signo]);
567 }
568 }
569
570 #endif /* ! HAVE_PSIGNAL */
571
572
573 /* A simple little main that does nothing but print all the signal translations
574 if MAIN is defined and this file is compiled and linked. */
575
576 #ifdef MAIN
577
578 #include <stdio.h>
579
580 int
581 main (void)
582 {
583 int signo;
584 int maxsigno;
585 const char *name;
586 const char *msg;
587
588 maxsigno = signo_max ();
589 printf ("%d entries in names table.\n", num_signal_names);
590 printf ("%d entries in messages table.\n", sys_nsig);
591 printf ("%d is max useful index.\n", maxsigno);
592
593 /* Keep printing values until we get to the end of *both* tables, not
594 *either* table. Note that knowing the maximum useful index does *not*
595 relieve us of the responsibility of testing the return pointer for
596 NULL. */
597
598 for (signo = 0; signo <= maxsigno; signo++)
599 {
600 name = strsigno (signo);
601 name = (name == NULL) ? "<NULL>" : name;
602 msg = strsignal (signo);
603 msg = (msg == NULL) ? "<NULL>" : msg;
604 printf ("%-4d%-18s%s\n", signo, name, msg);
605 }
606
607 return 0;
608 }
609
610 #endif