1 /* Copyright (C) 1991, 1994-2002, 2005, 2008-2023 Free Software Foundation,
2 Inc.
3 This file is part of the GNU C Library.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #ifndef _LIBC
19 # include <config.h>
20 #endif
21
22 /* Specification. */
23 #include <string.h>
24
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28
29 #ifdef _LIBC
30 # include <libintl.h>
31 #else /* !_LIBC */
32 # include "gettext.h"
33 # define _(msgid) gettext (msgid)
34 # define N_(msgid) gettext_noop (msgid)
35 #endif /* _LIBC */
36
37 #ifdef _LIBC
38 # include <bits/libc-lock.h>
39 #else /* !_LIBC */
40 # include "glthread/lock.h"
41 # include "glthread/tls.h"
42 # define __libc_once_define(CLASS, NAME) gl_once_define (CLASS, NAME)
43 # define __libc_once(NAME, INIT) gl_once ((NAME), (INIT))
44 # define __libc_key_t gl_tls_key_t
45 # define __libc_getspecific(NAME) gl_tls_get ((NAME))
46 # define __libc_setspecific(NAME, POINTER) gl_tls_set ((NAME), (POINTER))
47 # define __snprintf snprintf
48 #endif /* _LIBC */
49
50 #ifdef _LIBC
51
52 /* Defined in siglist.c. */
53 extern const char *const _sys_siglist[];
54 extern const char *const _sys_siglist_internal[] attribute_hidden;
55
56 #else /* !_LIBC */
57
58 /* NetBSD declares sys_siglist in unistd.h. */
59 # if HAVE_UNISTD_H
60 # include <unistd.h>
61 # endif
62
63 # define INTUSE(x) (x)
64
65 # if HAVE_DECL_SYS_SIGLIST
66 # undef _sys_siglist
67 # define _sys_siglist sys_siglist
68 # else /* !HAVE_DECL_SYS_SIGLIST */
69 # ifndef NSIG
70 # define NSIG 32
71 # endif /* NSIG */
72 # if !HAVE_DECL__SYS_SIGLIST
73 static const char *_sys_siglist[NSIG];
74 # endif
75 # endif /* !HAVE_DECL_SYS_SIGLIST */
76
77 #endif /* _LIBC */
78
79 static __libc_key_t key;
80
81 /* If nonzero the key allocation failed and we should better use a
82 static buffer than fail. */
83 #define BUFFERSIZ 100
84 static char local_buf[BUFFERSIZ];
85 static char *static_buf;
86
87 /* Destructor for the thread-specific data. */
88 static void init (void);
89 static void free_key_mem (void *mem);
90 static char *getbuffer (void);
91
92
93 /* Return a string describing the meaning of the signal number SIGNUM. */
94 char *
95 strsignal (int signum)
96 {
97 const char *desc;
98 __libc_once_define (static, once);
99
100 /* If we have not yet initialized the buffer do it now. */
101 __libc_once (once, init);
102
103 if (
104 #ifdef SIGRTMIN
105 (signum >= SIGRTMIN && signum <= SIGRTMAX) ||
106 #endif
107 signum < 0 || signum >= NSIG
108 || (desc = INTUSE(_sys_siglist)[signum]) == NULL)
109 {
110 char *buffer = getbuffer ();
111 int len;
112 #ifdef SIGRTMIN
113 if (signum >= SIGRTMIN && signum <= SIGRTMAX)
114 len = __snprintf (buffer, BUFFERSIZ - 1, _("Real-time signal %d"),
115 signum - (int) SIGRTMIN);
116 else
117 #endif
118 len = __snprintf (buffer, BUFFERSIZ - 1, _("Unknown signal %d"),
119 signum);
120 if (len >= BUFFERSIZ)
121 buffer = NULL;
122 else
123 buffer[len] = '\0';
124
125 return buffer;
126 }
127
128 return (char *) _(desc);
129 }
130
131
132 /* Initialize buffer. */
133 static void
134 init (void)
135 {
136 #ifdef _LIBC
137 if (__libc_key_create (&key, free_key_mem))
138 /* Creating the key failed. This means something really went
139 wrong. In any case use a static buffer which is better than
140 nothing. */
141 static_buf = local_buf;
142 #else /* !_LIBC */
143 gl_tls_key_init (key, free_key_mem);
144
145 # if !HAVE_DECL_SYS_SIGLIST
146 memset (_sys_siglist, 0, NSIG * sizeof *_sys_siglist);
147
148 /* No need to use a do {} while (0) here since init_sig(...) must expand
149 to a complete statement. (We cannot use the ISO C99 designated array
150 initializer syntax since it is not supported by ANSI C compilers and
151 since some signal numbers might exceed NSIG.) */
152 # define init_sig(sig, abbrev, desc) \
153 if (sig >= 0 && sig < NSIG) \
154 _sys_siglist[sig] = desc;
155
156 # include "siglist.h"
157
158 # undef init_sig
159
160 # endif /* !HAVE_DECL_SYS_SIGLIST */
161 #endif /* !_LIBC */
162 }
163
164
165 /* Free the thread specific data, this is done if a thread terminates. */
166 static void
167 free_key_mem (void *mem)
168 {
169 free (mem);
170 __libc_setspecific (key, NULL);
171 }
172
173
174 /* Return the buffer to be used. */
175 static char *
176 getbuffer (void)
177 {
178 char *result;
179
180 if (static_buf != NULL)
181 result = static_buf;
182 else
183 {
184 /* We don't use the static buffer and so we have a key. Use it
185 to get the thread-specific buffer. */
186 result = __libc_getspecific (key);
187 if (result == NULL)
188 {
189 /* No buffer allocated so far. */
190 result = malloc (BUFFERSIZ);
191 if (result == NULL)
192 /* No more memory available. We use the static buffer. */
193 result = local_buf;
194 else
195 __libc_setspecific (key, result);
196 }
197 }
198
199 return result;
200 }