gnulib/import/m4/strerror_r.m4

   1 # strerror_r.m4 serial 18
   2 dnl Copyright (C) 2002, 2007-2016 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 AC_DEFUN([gl_FUNC_STRERROR_R],
   8 [
   9   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
  10   AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
  11
  12   dnl Persuade Solaris <string.h> to declare strerror_r().
  13   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  14
  15   dnl Some systems don't declare strerror_r() if _THREAD_SAFE and _REENTRANT
  16   dnl are not defined.
  17   AC_CHECK_DECL([strerror_r],
  18     [HAVE_DECL_STRERROR_R=1], [HAVE_DECL_STRERROR_R=0])
  19   AC_DEFINE_UNQUOTED([HAVE_DECL_STRERROR_R_ORIG], [$HAVE_DECL_STRERROR_R],
  20     [Define to 1 if you have the declaration of 'strerror_r' in the system include files, or to 0 otherwise.])
  21
  22   if test $ac_cv_func_strerror_r = yes; then
  23     if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
  24       if test $gl_cv_func_strerror_r_posix_signature = yes; then
  25         case "$gl_cv_func_strerror_r_works" in
  26           dnl The system's strerror_r has bugs.  Replace it.
  27           *no) REPLACE_STRERROR_R=1 ;;
  28         esac
  29       else
  30         dnl The system's strerror_r() has a wrong signature. Replace it.
  31         REPLACE_STRERROR_R=1
  32       fi
  33     else
  34       dnl The system's strerror_r() cannot know about the new errno values we
  35       dnl add to <errno.h>, or any fix for strerror(0). Replace it.
  36       REPLACE_STRERROR_R=1
  37     fi
  38   fi
  39
  40   # Overwrite the findings of AC_FUNC_STRERROR_R (for code that uses that).
  41   AC_REQUIRE([AC_FUNC_STRERROR_R])
  42 ])
  43
  44 # If this module is in use, we unconditionally want POSIX semantics; so
  45 # replace autoconf's macro with a version that does not probe
  46 AC_DEFUN([AC_FUNC_STRERROR_R], [
  47   AC_DEFINE([HAVE_DECL_STRERROR_R], [1],
  48     [Define to 1, since you should have the declaration of strerror_r.])
  49   AC_DEFINE([HAVE_STRERROR_R], [1],
  50     [Define to 1, since you should have the function strerror_r.])
  51   AC_DEFINE([STRERROR_R_CHAR_P], [0],
  52     [Define to 0, since strerror_r should not return char *.])
  53 ])
  54
  55 # Prerequisites of lib/strerror_r.c.
  56 AC_DEFUN([gl_PREREQ_STRERROR_R], [
  57   dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
  58   AC_CHECK_FUNCS_ONCE([__xpg_strerror_r])
  59   AC_CHECK_FUNCS_ONCE([catgets])
  60   AC_CHECK_FUNCS_ONCE([snprintf])
  61 ])
  62
  63 # Detect if strerror_r works, but without affecting whether a replacement
  64 # strerror_r will be used.
  65 AC_DEFUN([gl_FUNC_STRERROR_R_WORKS],
  66 [
  67   AC_REQUIRE([gl_HEADER_ERRNO_H])
  68   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  69   AC_REQUIRE([gl_FUNC_STRERROR_0])
  70
  71   AC_CHECK_FUNC([strerror_r])
  72   if test $ac_cv_func_strerror_r = yes; then
  73     if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
  74       dnl The POSIX prototype is:  int strerror_r (int, char *, size_t);
  75       dnl glibc, Cygwin:           char *strerror_r (int, char *, size_t);
  76       dnl AIX 5.1, OSF/1 5.1:      int strerror_r (int, char *, int);
  77       AC_CACHE_CHECK([for strerror_r with POSIX signature],
  78         [gl_cv_func_strerror_r_posix_signature],
  79         [AC_COMPILE_IFELSE(
  80            [AC_LANG_PROGRAM(
  81               [[#include <string.h>
  82                 int strerror_r (int, char *, size_t);
  83               ]],
  84               [])],
  85            [gl_cv_func_strerror_r_posix_signature=yes],
  86            [gl_cv_func_strerror_r_posix_signature=no])
  87         ])
  88       if test $gl_cv_func_strerror_r_posix_signature = yes; then
  89         dnl AIX 6.1 strerror_r fails by returning -1, not an error number.
  90         dnl HP-UX 11.31 strerror_r always fails when the buffer length argument
  91         dnl is less than 80.
  92         dnl FreeBSD 8.s strerror_r claims failure on 0
  93         dnl Mac OS X 10.5 strerror_r treats 0 like -1
  94         dnl Solaris 10 strerror_r corrupts errno on failure
  95         AC_CACHE_CHECK([whether strerror_r works],
  96           [gl_cv_func_strerror_r_works],
  97           [AC_RUN_IFELSE(
  98              [AC_LANG_PROGRAM(
  99                 [[#include <errno.h>
 100                   #include <string.h>
 101                 ]],
 102                 [[int result = 0;
 103                   char buf[79];
 104                   if (strerror_r (EACCES, buf, 0) < 0)
 105                     result |= 1;
 106                   errno = 0;
 107                   if (strerror_r (EACCES, buf, sizeof buf) != 0)
 108                     result |= 2;
 109                   strcpy (buf, "Unknown");
 110                   if (strerror_r (0, buf, sizeof buf) != 0)
 111                     result |= 4;
 112                   if (errno)
 113                     result |= 8;
 114                   if (strstr (buf, "nknown") || strstr (buf, "ndefined"))
 115                     result |= 0x10;
 116                   errno = 0;
 117                   *buf = 0;
 118                   if (strerror_r (-3, buf, sizeof buf) < 0)
 119                     result |= 0x20;
 120                   if (errno)
 121                     result |= 0x40;
 122                   if (!*buf)
 123                     result |= 0x80;
 124                   return result;
 125                 ]])],
 126              [gl_cv_func_strerror_r_works=yes],
 127              [gl_cv_func_strerror_r_works=no],
 128              [
 129 changequote(,)dnl
 130               case "$host_os" in
 131                        # Guess no on AIX.
 132                 aix*)  gl_cv_func_strerror_r_works="guessing no";;
 133                        # Guess no on HP-UX.
 134                 hpux*) gl_cv_func_strerror_r_works="guessing no";;
 135                        # Guess no on BSD variants.
 136                 *bsd*)  gl_cv_func_strerror_r_works="guessing no";;
 137                        # Guess yes otherwise.
 138                 *)     gl_cv_func_strerror_r_works="guessing yes";;
 139               esac
 140 changequote([,])dnl
 141              ])
 142           ])
 143       else
 144         dnl The system's strerror() has a wrong signature.
 145         dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
 146         AC_CHECK_FUNCS_ONCE([__xpg_strerror_r])
 147         dnl In glibc < 2.14, __xpg_strerror_r does not populate buf on failure.
 148         dnl In cygwin < 1.7.10, __xpg_strerror_r clobbers strerror's buffer.
 149         if test $ac_cv_func___xpg_strerror_r = yes; then
 150           AC_CACHE_CHECK([whether __xpg_strerror_r works],
 151             [gl_cv_func_strerror_r_works],
 152             [AC_RUN_IFELSE(
 153                [AC_LANG_PROGRAM(
 154                   [[#include <errno.h>
 155                     #include <string.h>
 156                     extern
 157                     #ifdef __cplusplus
 158                     "C"
 159                     #endif
 160                     int __xpg_strerror_r(int, char *, size_t);
 161                   ]],
 162                   [[int result = 0;
 163                     char buf[256] = "^";
 164                     char copy[256];
 165                     char *str = strerror (-1);
 166                     strcpy (copy, str);
 167                     if (__xpg_strerror_r (-2, buf, 1) == 0)
 168                       result |= 1;
 169                     if (*buf)
 170                       result |= 2;
 171                     __xpg_strerror_r (-2, buf, 256);
 172                     if (strcmp (str, copy))
 173                       result |= 4;
 174                     return result;
 175                   ]])],
 176                [gl_cv_func_strerror_r_works=yes],
 177                [gl_cv_func_strerror_r_works=no],
 178                [dnl Guess no on all platforms that have __xpg_strerror_r,
 179                 dnl at least until fixed glibc and cygwin are more common.
 180                 gl_cv_func_strerror_r_works="guessing no"
 181                ])
 182             ])
 183         fi
 184       fi
 185     fi
 186   fi
 187 ])