build/aclocal/ax_func_which_gethostbyname_r.m4

   1 dnl @synopsis AX_FUNC_WHICH_GETHOSTBYNAME_R
   2 dnl
   3 dnl Determines which historical variant of the gethostbyname_r() call
   4 dnl (taking three, five, or six arguments) is available on the system
   5 dnl and defines one of the following macros accordingly:
   6 dnl
   7 dnl   HAVE_FUNC_GETHOSTBYNAME_R_6
   8 dnl   HAVE_FUNC_GETHOSTBYNAME_R_5
   9 dnl   HAVE_FUNC_GETHOSTBYNAME_R_3
  10 dnl
  11 dnl If used in conjunction with gethostname.c, the API demonstrated in
  12 dnl test.c can be used regardless of which gethostbyname_r() is
  13 dnl available. These example files can be found at
  14 dnl http://www.csn.ul.ie/~caolan/publink/gethostbyname_r
  15 dnl
  16 dnl based on David Arnold's autoconf suggestion in the threads faq
  17 dnl
  18 dnl Originally named "AC_caolan_FUNC_WHICH_GETHOSTBYNAME_R". Rewritten
  19 dnl for Autoconf 2.5x by Daniel Richard G.
  20 dnl
  21 dnl @category InstalledPackages
  22 dnl @author Caolan McNamara <caolan@skynet.ie>
  23 dnl @author Daniel Richard G. <skunk@iskunk.org>
  24 dnl @version 2005-01-21
  25 dnl @license GPLWithACException
  26
  27 AC_DEFUN([AX_FUNC_WHICH_GETHOSTBYNAME_R], [
  28
  29     AC_LANG_PUSH(C)
  30     AC_MSG_CHECKING([how many arguments gethostbyname_r() takes])
  31
  32     AC_CACHE_VAL(ac_cv_func_which_gethostbyname_r, [
  33
  34 ################################################################
  35
  36 ac_cv_func_which_gethostbyname_r=unknown
  37
  38 #
  39 # ONE ARGUMENT (sanity check)
  40 #
  41
  42 # This should fail, as there is no variant of gethostbyname_r() that takes
  43 # a single argument. If it actually compiles, then we can assume that
  44 # netdb.h is not declaring the function, and the compiler is thereby
  45 # assuming an implicit prototype. In which case, we're out of luck.
  46 #
  47 AC_COMPILE_IFELSE(
  48     AC_LANG_PROGRAM(
  49         [[#include <netdb.h>]],
  50         [[
  51             char *name = "www.gnu.org";
  52             (void)gethostbyname_r(name) /* ; */
  53         ]]),
  54     ac_cv_func_which_gethostbyname_r=no)
  55
  56 #
  57 # SIX ARGUMENTS
  58 # (e.g. Linux)
  59 #
  60
  61 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
  62
  63 AC_COMPILE_IFELSE(
  64     AC_LANG_PROGRAM(
  65         [[#include <netdb.h>]],
  66         [[
  67             char *name = "www.gnu.org";
  68             struct hostent ret, *retp;
  69             char buf@<:@1024@:>@;
  70             int buflen = 1024;
  71             int my_h_errno;
  72             (void)gethostbyname_r(name, &ret, buf, buflen, &retp, &my_h_errno) /* ; */
  73         ]]),
  74     ac_cv_func_which_gethostbyname_r=six)
  75
  76 fi
  77
  78 #
  79 # FIVE ARGUMENTS
  80 # (e.g. Solaris)
  81 #
  82
  83 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
  84
  85 AC_COMPILE_IFELSE(
  86     AC_LANG_PROGRAM(
  87         [[#include <netdb.h>]],
  88         [[
  89             char *name = "www.gnu.org";
  90             struct hostent ret;
  91             char buf@<:@1024@:>@;
  92             int buflen = 1024;
  93             int my_h_errno;
  94             (void)gethostbyname_r(name, &ret, buf, buflen, &my_h_errno) /* ; */
  95         ]]),
  96     ac_cv_func_which_gethostbyname_r=five)
  97
  98 fi
  99
 100 #
 101 # THREE ARGUMENTS
 102 # (e.g. AIX, HP-UX, Tru64)
 103 #
 104
 105 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
 106
 107 AC_COMPILE_IFELSE(
 108     AC_LANG_PROGRAM(
 109         [[#include <netdb.h>]],
 110         [[
 111             char *name = "www.gnu.org";
 112             struct hostent ret;
 113             struct hostent_data data;
 114             (void)gethostbyname_r(name, &ret, &data) /* ; */
 115         ]]),
 116     ac_cv_func_which_gethostbyname_r=three)
 117
 118 fi
 119
 120 ################################################################
 121
 122 ]) dnl end AC_CACHE_VAL
 123
 124 case "$ac_cv_func_which_gethostbyname_r" in
 125     three)
 126     AC_MSG_RESULT([three])
 127     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_3)
 128     ;;
 129
 130     five)
 131     AC_MSG_RESULT([five])
 132     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_5)
 133     ;;
 134
 135     six)
 136     AC_MSG_RESULT([six])
 137     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_6)
 138     ;;
 139
 140     no)
 141     AC_MSG_RESULT([cannot find function declaration in netdb.h])
 142     ;;
 143
 144     unknown)
 145     AC_MSG_RESULT([can't tell])
 146     ;;
 147
 148     *)
 149     AC_MSG_ERROR([internal error])
 150     ;;
 151 esac
 152
 153 AC_LANG_POP(C)
 154
 155 ]) dnl end AC_DEFUN