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     )],
  55     ac_cv_func_which_gethostbyname_r=no
  56     )
  57
  58 #
  59 # SIX ARGUMENTS
  60 # (e.g. Linux)
  61 #
  62
  63 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
  64
  65 AC_COMPILE_IFELSE(
  66     [AC_LANG_PROGRAM(
  67         [[#include <netdb.h>]],
  68         [[
  69             char *name = "www.gnu.org";
  70             struct hostent ret, *retp;
  71             char buf@<:@1024@:>@;
  72             int buflen = 1024;
  73             int my_h_errno;
  74             (void)gethostbyname_r(name, &ret, buf, buflen, &retp, &my_h_errno) /* ; */
  75         ]]
  76     )],
  77     ac_cv_func_which_gethostbyname_r=six
  78     )
  79
  80 fi
  81
  82 #
  83 # FIVE ARGUMENTS
  84 # (e.g. Solaris)
  85 #
  86
  87 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
  88
  89 AC_COMPILE_IFELSE(
  90     [AC_LANG_PROGRAM(
  91         [[#include <netdb.h>]],
  92         [[
  93             char *name = "www.gnu.org";
  94             struct hostent ret;
  95             char buf@<:@1024@:>@;
  96             int buflen = 1024;
  97             int my_h_errno;
  98             (void)gethostbyname_r(name, &ret, buf, buflen, &my_h_errno) /* ; */
  99         ]]
 100     )],
 101     ac_cv_func_which_gethostbyname_r=five
 102     )
 103
 104 fi
 105
 106 #
 107 # THREE ARGUMENTS
 108 # (e.g. AIX, HP-UX, Tru64)
 109 #
 110
 111 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
 112
 113 AC_COMPILE_IFELSE(
 114     [AC_LANG_PROGRAM(
 115         [[#include <netdb.h>]],
 116         [[
 117             char *name = "www.gnu.org";
 118             struct hostent ret;
 119             struct hostent_data data;
 120             (void)gethostbyname_r(name, &ret, &data) /* ; */
 121         ]]
 122     )],
 123     ac_cv_func_which_gethostbyname_r=three
 124     )
 125
 126 fi
 127
 128 ################################################################
 129
 130 ]) dnl end AC_CACHE_VAL
 131
 132 case "$ac_cv_func_which_gethostbyname_r" in
 133     three)
 134     AC_MSG_RESULT([three])
 135     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_3)
 136     ;;
 137
 138     five)
 139     AC_MSG_RESULT([five])
 140     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_5)
 141     ;;
 142
 143     six)
 144     AC_MSG_RESULT([six])
 145     AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_6)
 146     ;;
 147
 148     no)
 149     AC_MSG_RESULT([cannot find function declaration in netdb.h])
 150     ;;
 151
 152     unknown)
 153     AC_MSG_RESULT([can't tell])
 154     ;;
 155
 156     *)
 157     AC_MSG_ERROR([internal error])
 158     ;;
 159 esac
 160
 161 AC_LANG_POP(C)
 162
 163 ]) dnl end AC_DEFUN