glibc/posix/confstr.c

295 lines
8.8 KiB
C

/* Copyright (C) 1991-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <stddef.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <confstr.h>
#include "../version.h"
#define NEED_SPEC_ARRAY 0
#include <posix-conf-vars.h>
/* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
of BUF with the value corresponding to NAME and zero-terminate BUF.
Return the number of bytes required to hold NAME's entire value. */
size_t
__confstr (int name, char *buf, size_t len)
{
const char *string = "";
size_t string_len = 1;
/* Note that this buffer must be large enough for the longest strings
used below. */
char restenvs[4 * sizeof "POSIX_V7_LPBIG_OFFBIG"];
switch (name)
{
case _CS_PATH:
{
static const char cs_path[] = CS_PATH;
string = cs_path;
string_len = sizeof (cs_path);
}
break;
/* For _CS_V7_WIDTH_RESTRICTED_ENVS, _CS_V6_WIDTH_RESTRICTED_ENVS
and _CS_V5_WIDTH_RESTRICTED_ENVS:
We have to return a newline-separated list of names of
programming environments in which the widths of blksize_t,
cc_t, mode_t, nfds_t, pid_t, ptrdiff_t, size_t, speed_t,
ssize_t, suseconds_t, tcflag_t, useconds_t, wchar_t, and
wint_t types are no greater than the width of type long.
Currently this means all environments that the system allows. */
#define START_ENV_GROUP(VERSION) \
case _CS_##VERSION##_WIDTH_RESTRICTED_ENVS: \
string_len = 0;
#define END_ENV_GROUP(VERSION) \
restenvs[string_len++] = '\0'; \
string = restenvs; \
break;
#define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
/* Empty. */
#define KNOWN_PRESENT_ENV_STRING(STR) \
if (string_len > 0) \
restenvs[string_len++] = '\n'; \
memcpy (restenvs + string_len, STR, \
sizeof STR - 1); \
string_len += sizeof STR - 1;
#define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
KNOWN_PRESENT_ENV_STRING (#ENV_PREFIX "_" #SUFFIX)
#define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
if (__sysconf (_SC_##SC_PREFIX##_##SUFFIX) > 0) \
{ \
KNOWN_PRESENT_ENVIRONMENT (SC_PREFIX, ENV_PREFIX, SUFFIX) \
}
#include "posix-envs.def"
#undef START_ENV_GROUP
#undef END_ENV_GROUP
#undef KNOWN_ABSENT_ENVIRONMENT
#undef KNOWN_PRESENT_ENV_STRING
#undef KNOWN_PRESENT_ENVIRONMENT
#undef UNKNOWN_ENVIRONMENT
case _CS_XBS5_ILP32_OFF32_CFLAGS:
case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
case _CS_POSIX_V7_ILP32_OFF32_CFLAGS:
#ifdef __ILP32_OFF32_CFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32)
# error "__ILP32_OFF32_CFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
break;
# endif
string = __ILP32_OFF32_CFLAGS;
string_len = sizeof (__ILP32_OFF32_CFLAGS);
#endif
break;
case _CS_XBS5_ILP32_OFFBIG_CFLAGS:
case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
case _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS:
#ifdef __ILP32_OFFBIG_CFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
# error "__ILP32_OFFBIG_CFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
break;
# endif
string = __ILP32_OFFBIG_CFLAGS;
string_len = sizeof (__ILP32_OFFBIG_CFLAGS);
#endif
break;
case _CS_XBS5_LP64_OFF64_CFLAGS:
case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
case _CS_POSIX_V7_LP64_OFF64_CFLAGS:
#ifdef __LP64_OFF64_CFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
# error "__LP64_OFF64_CFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
if (__sysconf (_SC_V7_LP64_OFF64) < 0)
break;
# endif
string = __LP64_OFF64_CFLAGS;
string_len = sizeof (__LP64_OFF64_CFLAGS);
#endif
break;
case _CS_XBS5_ILP32_OFF32_LDFLAGS:
case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
case _CS_POSIX_V7_ILP32_OFF32_LDFLAGS:
#ifdef __ILP32_OFF32_LDFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFF32 )
# error "__ILP32_OFF32_LDFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFF32)
if (__sysconf (_SC_V7_ILP32_OFF32) < 0)
break;
# endif
string = __ILP32_OFF32_LDFLAGS;
string_len = sizeof (__ILP32_OFF32_LDFLAGS);
#endif
break;
case _CS_XBS5_ILP32_OFFBIG_LDFLAGS:
case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
case _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS:
#ifdef __ILP32_OFFBIG_LDFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_ILP32_OFFBIG)
# error "__ILP32_OFFBIG_LDFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_ILP32_OFFBIG)
if (__sysconf (_SC_V7_ILP32_OFFBIG) < 0)
break;
# endif
string = __ILP32_OFFBIG_LDFLAGS;
string_len = sizeof (__ILP32_OFFBIG_LDFLAGS);
#endif
break;
case _CS_XBS5_LP64_OFF64_LDFLAGS:
case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
case _CS_POSIX_V7_LP64_OFF64_LDFLAGS:
#ifdef __LP64_OFF64_LDFLAGS
# if CONF_IS_DEFINED_UNSET (_POSIX_V7_LP64_OFF64)
# error "__LP64_OFF64_LDFLAGS should not be defined"
# elif CONF_IS_UNDEFINED (_POSIX_V7_LP64_OFF64)
if (__sysconf (_SC_V7_LP64_OFF64) < 0)
break;
# endif
string = __LP64_OFF64_LDFLAGS;
string_len = sizeof (__LP64_OFF64_LDFLAGS);
#endif
break;
case _CS_LFS_CFLAGS:
case _CS_LFS_LINTFLAGS:
#if (CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFF32) \
&& CONF_IS_DEFINED_SET (_POSIX_V6_ILP32_OFFBIG))
# define __LFS_CFLAGS "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
/* Signal that we want the new ABI. */
string = __LFS_CFLAGS;
string_len = sizeof (__LFS_CFLAGS);
#endif
break;
case _CS_LFS_LDFLAGS:
case _CS_LFS_LIBS:
/* No special libraries or linker flags needed. */
break;
case _CS_LFS64_CFLAGS:
case _CS_LFS64_LINTFLAGS:
#define __LFS64_CFLAGS "-D_LARGEFILE64_SOURCE"
string = __LFS64_CFLAGS;
string_len = sizeof (__LFS64_CFLAGS);
break;
case _CS_LFS64_LDFLAGS:
case _CS_LFS64_LIBS:
/* No special libraries or linker flags needed. */
break;
case _CS_XBS5_ILP32_OFF32_LIBS:
case _CS_XBS5_ILP32_OFF32_LINTFLAGS:
case _CS_XBS5_ILP32_OFFBIG_LIBS:
case _CS_XBS5_ILP32_OFFBIG_LINTFLAGS:
case _CS_XBS5_LP64_OFF64_LIBS:
case _CS_XBS5_LP64_OFF64_LINTFLAGS:
case _CS_XBS5_LPBIG_OFFBIG_CFLAGS:
case _CS_XBS5_LPBIG_OFFBIG_LDFLAGS:
case _CS_XBS5_LPBIG_OFFBIG_LIBS:
case _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS:
case _CS_POSIX_V6_ILP32_OFF32_LIBS:
case _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS:
case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
case _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS:
case _CS_POSIX_V6_LP64_OFF64_LIBS:
case _CS_POSIX_V6_LP64_OFF64_LINTFLAGS:
case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
case _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS:
case _CS_POSIX_V7_ILP32_OFF32_LIBS:
case _CS_POSIX_V7_ILP32_OFF32_LINTFLAGS:
case _CS_POSIX_V7_ILP32_OFFBIG_LIBS:
case _CS_POSIX_V7_ILP32_OFFBIG_LINTFLAGS:
case _CS_POSIX_V7_LP64_OFF64_LIBS:
case _CS_POSIX_V7_LP64_OFF64_LINTFLAGS:
case _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS:
case _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS:
case _CS_POSIX_V7_LPBIG_OFFBIG_LIBS:
case _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS:
/* GNU libc does not require special actions to use LFS functions. */
break;
case _CS_GNU_LIBC_VERSION:
string = "glibc " VERSION;
string_len = sizeof ("glibc " VERSION);
break;
case _CS_GNU_LIBPTHREAD_VERSION:
#ifdef LIBPTHREAD_VERSION
string = LIBPTHREAD_VERSION;
string_len = sizeof LIBPTHREAD_VERSION;
break;
#else
/* No thread library. */
__set_errno (EINVAL);
return 0;
#endif
case _CS_V6_ENV:
case _CS_V7_ENV:
/* Maybe something else is needed in future. */
string = "POSIXLY_CORRECT=1";
string_len = sizeof ("POSIXLY_CORRECT=1");
break;
default:
__set_errno (EINVAL);
return 0;
}
if (len > 0 && buf != NULL)
{
if (string_len <= len)
memcpy (buf, string, string_len);
else
{
memcpy (buf, string, len - 1);
buf[len - 1] = '\0';
}
}
return string_len;
}
libc_hidden_def (__confstr)
libc_hidden_def (confstr)
weak_alias (__confstr, confstr)