/* Copyright (C) 1991-2018 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

   <http://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)