posix/confstr.c

   1 /* Copyright (C) 1991-2015 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    <http://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 (name, buf, len)
  33      int name;
  34      char *buf;
  35      size_t len;
  36 {
  37   const char *string = "";
  38   size_t string_len = 1;
  39
  40   /* Note that this buffer must be large enough for the longest strings
  41      used below.  */
  42   char restenvs[4 * sizeof "POSIX_V7_LPBIG_OFFBIG"];
  43
  44   switch (name)
  45     {
  46     case _CS_PATH:
  47       {
  48         static const char cs_path[] = CS_PATH;
  49         string = cs_path;
  50         string_len = sizeof (cs_path);
  51       }
  52       break;
  53
  54       /* For _CS_V7_WIDTH_RESTRICTED_ENVS, _CS_V6_WIDTH_RESTRICTED_ENVS
  55          and _CS_V5_WIDTH_RESTRICTED_ENVS:
  56
  57          We have to return a newline-separated list of names of
  58          programming environments in which the widths of blksize_t,
  59          cc_t, mode_t, nfds_t, pid_t, ptrdiff_t, size_t, speed_t,
  60          ssize_t, suseconds_t, tcflag_t, useconds_t, wchar_t, and
  61          wint_t types are no greater than the width of type long.
  62
  63          Currently this means all environments that the system allows.  */
  64
  65 #define START_ENV_GROUP(VERSION)                \
  66     case _CS_##VERSION##_WIDTH_RESTRICTED_ENVS: \
  67       string_len = 0;
  68
  69 #define END_ENV_GROUP(VERSION)                  \
  70       restenvs[string_len++] = '\0';            \
  71       string = restenvs;                        \
  72       break;
  73
  74 #define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
  75       /* Empty.  */
  76
  77 #define KNOWN_PRESENT_ENV_STRING(STR)           \
  78       if (string_len > 0)                       \
  79         restenvs[string_len++] = '\n';          \
  80       memcpy (restenvs + string_len, STR,       \
  81               sizeof STR - 1);                  \
  82       string_len += sizeof STR - 1;
  83
  84 #define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)        \
  85       KNOWN_PRESENT_ENV_STRING (#ENV_PREFIX "_" #SUFFIX)
  86
  87 #define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)              \
  88       if (__sysconf (_SC_##SC_PREFIX##_##SUFFIX) > 0)                   \
  89         {                                                               \
  90           KNOWN_PRESENT_ENVIRONMENT (SC_PREFIX, ENV_PREFIX, SUFFIX)     \
  91         }
  92
  93 #include "posix-envs.def"
  94
  95 #undef START_ENV_GROUP
  96 #undef END_ENV_GROUP
  97 #undef KNOWN_ABSENT_ENVIRONMENT
  98 #undef KNOWN_PRESENT_ENV_STRING
  99 #undef KNOWN_PRESENT_ENVIRONMENT
 100 #undef UNKNOWN_ENVIRONMENT
 101
 102     case _CS_XBS5_ILP32_OFF32_CFLAGS:
 103     case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
 104     case _CS_POSIX_V7_ILP32_OFF32_CFLAGS:
 105 #ifdef __ILP32_OFF32_CFLAGS
 106 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32)
 107 #  error "__ILP32_OFF32_CFLAGS should not be defined"
 108 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
 109       if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
 110         break;
 111 # endif
 112       string = __ILP32_OFF32_CFLAGS;
 113       string_len = sizeof (__ILP32_OFF32_CFLAGS);
 114 #endif
 115       break;
 116
 117     case _CS_XBS5_ILP32_OFFBIG_CFLAGS:
 118     case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
 119     case _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS:
 120 #ifdef __ILP32_OFFBIG_CFLAGS
 121 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
 122 #  error "__ILP32_OFFBIG_CFLAGS should not be defined"
 123 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
 124       if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
 125         break;
 126 # endif
 127       string = __ILP32_OFFBIG_CFLAGS;
 128       string_len = sizeof (__ILP32_OFFBIG_CFLAGS);
 129 #endif
 130       break;
 131
 132     case _CS_XBS5_LP64_OFF64_CFLAGS:
 133     case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
 134     case _CS_POSIX_V7_LP64_OFF64_CFLAGS:
 135 #ifdef __LP64_OFF64_CFLAGS
 136 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
 137 #  error "__LP64_OFF64_CFLAGS should not be defined"
 138 # elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
 139       if (__sysconf (_SC_V7_LP64_OFF64) < 0)
 140         break;
 141 # endif
 142       string = __LP64_OFF64_CFLAGS;
 143       string_len = sizeof (__LP64_OFF64_CFLAGS);
 144 #endif
 145       break;
 146
 147     case _CS_XBS5_ILP32_OFF32_LDFLAGS:
 148     case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
 149     case _CS_POSIX_V7_ILP32_OFF32_LDFLAGS:
 150 #ifdef __ILP32_OFF32_LDFLAGS
 151 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32 )
 152 #  error "__ILP32_OFF32_LDFLAGS should not be defined"
 153 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
 154       if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
 155         break;
 156 # endif
 157       string = __ILP32_OFF32_LDFLAGS;
 158       string_len = sizeof (__ILP32_OFF32_LDFLAGS);
 159 #endif
 160       break;
 161
 162     case _CS_XBS5_ILP32_OFFBIG_LDFLAGS:
 163     case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
 164     case _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS:
 165 #ifdef __ILP32_OFFBIG_LDFLAGS
 166 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
 167 #  error "__ILP32_OFFBIG_LDFLAGS should not be defined"
 168 # elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
 169       if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
 170         break;
 171 # endif
 172       string = __ILP32_OFFBIG_LDFLAGS;
 173       string_len = sizeof (__ILP32_OFFBIG_LDFLAGS);
 174 #endif
 175       break;
 176
 177     case _CS_XBS5_LP64_OFF64_LDFLAGS:
 178     case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
 179     case _CS_POSIX_V7_LP64_OFF64_LDFLAGS:
 180 #ifdef __LP64_OFF64_LDFLAGS
 181 # if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
 182 #  error "__LP64_OFF64_LDFLAGS should not be defined"
 183 # elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
 184       if (__sysconf (_SC_V7_LP64_OFF64) < 0)
 185         break;
 186 # endif
 187       string = __LP64_OFF64_LDFLAGS;
 188       string_len = sizeof (__LP64_OFF64_LDFLAGS);
 189 #endif
 190       break;
 191
 192     case _CS_LFS_CFLAGS:
 193     case _CS_LFS_LINTFLAGS:
 194 #if (CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFF32) \
 195      && CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFFBIG))
 196 # define __LFS_CFLAGS "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
 197       /* Signal that we want the new ABI.  */
 198       string = __LFS_CFLAGS;
 199       string_len = sizeof (__LFS_CFLAGS);
 200 #endif
 201       break;
 202
 203     case _CS_LFS_LDFLAGS:
 204     case _CS_LFS_LIBS:
 205       /* No special libraries or linker flags needed.  */
 206       break;
 207
 208     case _CS_LFS64_CFLAGS:
 209     case _CS_LFS64_LINTFLAGS:
 210 #define __LFS64_CFLAGS "-D_LARGEFILE64_SOURCE"
 211       string = __LFS64_CFLAGS;
 212       string_len = sizeof (__LFS64_CFLAGS);
 213       break;
 214
 215     case _CS_LFS64_LDFLAGS:
 216     case _CS_LFS64_LIBS:
 217       /* No special libraries or linker flags needed.  */
 218       break;
 219
 220     case _CS_XBS5_ILP32_OFF32_LIBS:
 221     case _CS_XBS5_ILP32_OFF32_LINTFLAGS:
 222     case _CS_XBS5_ILP32_OFFBIG_LIBS:
 223     case _CS_XBS5_ILP32_OFFBIG_LINTFLAGS:
 224     case _CS_XBS5_LP64_OFF64_LIBS:
 225     case _CS_XBS5_LP64_OFF64_LINTFLAGS:
 226     case _CS_XBS5_LPBIG_OFFBIG_CFLAGS:
 227     case _CS_XBS5_LPBIG_OFFBIG_LDFLAGS:
 228     case _CS_XBS5_LPBIG_OFFBIG_LIBS:
 229     case _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS:
 230
 231     case _CS_POSIX_V6_ILP32_OFF32_LIBS:
 232     case _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS:
 233     case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
 234     case _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS:
 235     case _CS_POSIX_V6_LP64_OFF64_LIBS:
 236     case _CS_POSIX_V6_LP64_OFF64_LINTFLAGS:
 237     case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
 238     case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
 239     case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
 240     case _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS:
 241
 242     case _CS_POSIX_V7_ILP32_OFF32_LIBS:
 243     case _CS_POSIX_V7_ILP32_OFF32_LINTFLAGS:
 244     case _CS_POSIX_V7_ILP32_OFFBIG_LIBS:
 245     case _CS_POSIX_V7_ILP32_OFFBIG_LINTFLAGS:
 246     case _CS_POSIX_V7_LP64_OFF64_LIBS:
 247     case _CS_POSIX_V7_LP64_OFF64_LINTFLAGS:
 248     case _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS:
 249     case _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS:
 250     case _CS_POSIX_V7_LPBIG_OFFBIG_LIBS:
 251     case _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS:
 252       /* GNU libc does not require special actions to use LFS functions.  */
 253       break;
 254
 255     case _CS_GNU_LIBC_VERSION:
 256       string = "glibc " VERSION;
 257       string_len = sizeof ("glibc " VERSION);
 258       break;
 259
 260     case _CS_GNU_LIBPTHREAD_VERSION:
 261 #ifdef LIBPTHREAD_VERSION
 262       string = LIBPTHREAD_VERSION;
 263       string_len = sizeof LIBPTHREAD_VERSION;
 264       break;
 265 #else
 266       /* No thread library.  */
 267       __set_errno (EINVAL);
 268       return 0;
 269 #endif
 270
 271     case _CS_V6_ENV:
 272     case _CS_V7_ENV:
 273       /* Maybe something else is needed in future.  */
 274       string = "POSIXLY_CORRECT=1";
 275       string_len = sizeof ("POSIXLY_CORRECT=1");
 276       break;
 277
 278     default:
 279       __set_errno (EINVAL);
 280       return 0;
 281     }
 282
 283   if (len > 0 && buf != NULL)
 284     {
 285       if (string_len <= len)
 286         memcpy (buf, string, string_len);
 287       else
 288         {
 289           memcpy (buf, string, len - 1);
 290           buf[len - 1] = '\0';
 291         }
 292     }
 293   return string_len;
 294 }
 295 libc_hidden_def (confstr)