1 /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <stddef.h>
19 #include <errno.h>
20 #include <unistd.h>
21 #include <string.h>
22 #include <confstr.h>
23 #include "../version.h"
24
25 #define NEED_SPEC_ARRAY 0
26 #include <posix-conf-vars.h>
27
28 /* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
29 of BUF with the value corresponding to NAME and zero-terminate BUF.
30 Return the number of bytes required to hold NAME's entire value. */
31 size_t
32 __confstr (int name, char *buf, size_t len)
33 {
34 const char *string = "";
35 size_t string_len = 1;
36
37 /* Note that this buffer must be large enough for the longest strings
38 used below. */
39 char restenvs[4 * sizeof "POSIX_V7_LPBIG_OFFBIG"];
40
41 switch (name)
42 {
43 case _CS_PATH:
44 {
45 static const char cs_path[] = CS_PATH;
46 string = cs_path;
47 string_len = sizeof (cs_path);
48 }
49 break;
50
51 /* For _CS_V7_WIDTH_RESTRICTED_ENVS, _CS_V6_WIDTH_RESTRICTED_ENVS
52 and _CS_V5_WIDTH_RESTRICTED_ENVS:
53
54 We have to return a newline-separated list of names of
55 programming environments in which the widths of blksize_t,
56 cc_t, mode_t, nfds_t, pid_t, ptrdiff_t, size_t, speed_t,
57 ssize_t, suseconds_t, tcflag_t, useconds_t, wchar_t, and
58 wint_t types are no greater than the width of type long.
59
60 Currently this means all environments that the system allows. */
61
62 #define START_ENV_GROUP(VERSION) \
63 case _CS_##VERSION##_WIDTH_RESTRICTED_ENVS: \
64 string_len = 0;
65
66 #define END_ENV_GROUP(VERSION) \
67 restenvs[string_len++] = '\0'; \
68 string = restenvs; \
69 break;
70
71 #define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
72 /* Empty. */
73
74 #define KNOWN_PRESENT_ENV_STRING(STR) \
75 if (string_len > 0) \
76 restenvs[string_len++] = '\n'; \
77 memcpy (restenvs + string_len, STR, \
78 sizeof STR - 1); \
79 string_len += sizeof STR - 1;
80
81 #define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
82 KNOWN_PRESENT_ENV_STRING (#ENV_PREFIX "_" #SUFFIX)
83
84 #define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
85 if (__sysconf (_SC_##SC_PREFIX##_##SUFFIX) > 0) \
86 { \
87 KNOWN_PRESENT_ENVIRONMENT (SC_PREFIX, ENV_PREFIX, SUFFIX) \
88 }
89
90 #include "posix-envs.def"
91
92 #undef START_ENV_GROUP
93 #undef END_ENV_GROUP
94 #undef KNOWN_ABSENT_ENVIRONMENT
95 #undef KNOWN_PRESENT_ENV_STRING
96 #undef KNOWN_PRESENT_ENVIRONMENT
97 #undef UNKNOWN_ENVIRONMENT
98
99 case _CS_XBS5_ILP32_OFF32_CFLAGS:
100 case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
101 case _CS_POSIX_V7_ILP32_OFF32_CFLAGS:
102 #ifdef __ILP32_OFF32_CFLAGS
103 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32)
104 # error "__ILP32_OFF32_CFLAGS should not be defined"
105 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
106 if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
107 break;
108 # endif
109 string = __ILP32_OFF32_CFLAGS;
110 string_len = sizeof (__ILP32_OFF32_CFLAGS);
111 #endif
112 break;
113
114 case _CS_XBS5_ILP32_OFFBIG_CFLAGS:
115 case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
116 case _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS:
117 #ifdef __ILP32_OFFBIG_CFLAGS
118 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
119 # error "__ILP32_OFFBIG_CFLAGS should not be defined"
120 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
121 if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
122 break;
123 # endif
124 string = __ILP32_OFFBIG_CFLAGS;
125 string_len = sizeof (__ILP32_OFFBIG_CFLAGS);
126 #endif
127 break;
128
129 case _CS_XBS5_LP64_OFF64_CFLAGS:
130 case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
131 case _CS_POSIX_V7_LP64_OFF64_CFLAGS:
132 #ifdef __LP64_OFF64_CFLAGS
133 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
134 # error "__LP64_OFF64_CFLAGS should not be defined"
135 # elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
136 if (__sysconf (_SC_V7_LP64_OFF64) < 0)
137 break;
138 # endif
139 string = __LP64_OFF64_CFLAGS;
140 string_len = sizeof (__LP64_OFF64_CFLAGS);
141 #endif
142 break;
143
144 case _CS_XBS5_ILP32_OFF32_LDFLAGS:
145 case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
146 case _CS_POSIX_V7_ILP32_OFF32_LDFLAGS:
147 #ifdef __ILP32_OFF32_LDFLAGS
148 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32 )
149 # error "__ILP32_OFF32_LDFLAGS should not be defined"
150 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
151 if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
152 break;
153 # endif
154 string = __ILP32_OFF32_LDFLAGS;
155 string_len = sizeof (__ILP32_OFF32_LDFLAGS);
156 #endif
157 break;
158
159 case _CS_XBS5_ILP32_OFFBIG_LDFLAGS:
160 case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
161 case _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS:
162 #ifdef __ILP32_OFFBIG_LDFLAGS
163 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
164 # error "__ILP32_OFFBIG_LDFLAGS should not be defined"
165 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
166 if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
167 break;
168 # endif
169 string = __ILP32_OFFBIG_LDFLAGS;
170 string_len = sizeof (__ILP32_OFFBIG_LDFLAGS);
171 #endif
172 break;
173
174 case _CS_XBS5_LP64_OFF64_LDFLAGS:
175 case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
176 case _CS_POSIX_V7_LP64_OFF64_LDFLAGS:
177 #ifdef __LP64_OFF64_LDFLAGS
178 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
179 # error "__LP64_OFF64_LDFLAGS should not be defined"
180 # elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
181 if (__sysconf (_SC_V7_LP64_OFF64) < 0)
182 break;
183 # endif
184 string = __LP64_OFF64_LDFLAGS;
185 string_len = sizeof (__LP64_OFF64_LDFLAGS);
186 #endif
187 break;
188
189 case _CS_LFS_CFLAGS:
190 case _CS_LFS_LINTFLAGS:
191 #if (CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFF32) \
192 && CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFFBIG))
193 # define __LFS_CFLAGS "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
194 /* Signal that we want the new ABI. */
195 string = __LFS_CFLAGS;
196 string_len = sizeof (__LFS_CFLAGS);
197 #endif
198 break;
199
200 case _CS_LFS_LDFLAGS:
201 case _CS_LFS_LIBS:
202 /* No special libraries or linker flags needed. */
203 break;
204
205 case _CS_LFS64_CFLAGS:
206 case _CS_LFS64_LINTFLAGS:
207 #define __LFS64_CFLAGS "-D_LARGEFILE64_SOURCE"
208 string = __LFS64_CFLAGS;
209 string_len = sizeof (__LFS64_CFLAGS);
210 break;
211
212 case _CS_LFS64_LDFLAGS:
213 case _CS_LFS64_LIBS:
214 /* No special libraries or linker flags needed. */
215 break;
216
217 case _CS_XBS5_ILP32_OFF32_LIBS:
218 case _CS_XBS5_ILP32_OFF32_LINTFLAGS:
219 case _CS_XBS5_ILP32_OFFBIG_LIBS:
220 case _CS_XBS5_ILP32_OFFBIG_LINTFLAGS:
221 case _CS_XBS5_LP64_OFF64_LIBS:
222 case _CS_XBS5_LP64_OFF64_LINTFLAGS:
223 case _CS_XBS5_LPBIG_OFFBIG_CFLAGS:
224 case _CS_XBS5_LPBIG_OFFBIG_LDFLAGS:
225 case _CS_XBS5_LPBIG_OFFBIG_LIBS:
226 case _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS:
227
228 case _CS_POSIX_V6_ILP32_OFF32_LIBS:
229 case _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS:
230 case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
231 case _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS:
232 case _CS_POSIX_V6_LP64_OFF64_LIBS:
233 case _CS_POSIX_V6_LP64_OFF64_LINTFLAGS:
234 case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
235 case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
236 case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
237 case _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS:
238
239 case _CS_POSIX_V7_ILP32_OFF32_LIBS:
240 case _CS_POSIX_V7_ILP32_OFF32_LINTFLAGS:
241 case _CS_POSIX_V7_ILP32_OFFBIG_LIBS:
242 case _CS_POSIX_V7_ILP32_OFFBIG_LINTFLAGS:
243 case _CS_POSIX_V7_LP64_OFF64_LIBS:
244 case _CS_POSIX_V7_LP64_OFF64_LINTFLAGS:
245 case _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS:
246 case _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS:
247 case _CS_POSIX_V7_LPBIG_OFFBIG_LIBS:
248 case _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS:
249 /* GNU libc does not require special actions to use LFS functions. */
250 break;
251
252 case _CS_GNU_LIBC_VERSION:
253 string = "glibc " VERSION;
254 string_len = sizeof ("glibc " VERSION);
255 break;
256
257 case _CS_GNU_LIBPTHREAD_VERSION:
258 #ifdef LIBPTHREAD_VERSION
259 string = LIBPTHREAD_VERSION;
260 string_len = sizeof LIBPTHREAD_VERSION;
261 break;
262 #else
263 /* No thread library. */
264 __set_errno (EINVAL);
265 return 0;
266 #endif
267
268 case _CS_V6_ENV:
269 case _CS_V7_ENV:
270 /* Maybe something else is needed in future. */
271 string = "POSIXLY_CORRECT=1";
272 string_len = sizeof ("POSIXLY_CORRECT=1");
273 break;
274
275 default:
276 __set_errno (EINVAL);
277 return 0;
278 }
279
280 if (len > 0 && buf != NULL)
281 {
282 if (string_len <= len)
283 memcpy (buf, string, string_len);
284 else
285 {
286 memcpy (buf, string, len - 1);
287 buf[len - 1] = '\0';
288 }
289 }
290 return string_len;
291 }
292 libc_hidden_def (__confstr)
293 libc_hidden_def (confstr)
294 weak_alias (__confstr, confstr)