FreeBSD/Linux Kernel Cross Reference
sys/contrib/libsodium/m4/ax_check_define.m4

     # ===========================================================================
     #     https://www.gnu.org/software/autoconf-archive/ax_check_define.html
     # ===========================================================================
     #
     # SYNOPSIS
     #
     #   AC_CHECK_DEFINE([symbol], [ACTION-IF-FOUND], [ACTION-IF-NOT])
     #   AX_CHECK_DEFINE([includes],[symbol], [ACTION-IF-FOUND], [ACTION-IF-NOT])
     #
    # DESCRIPTION
    #
    #   Complements AC_CHECK_FUNC but it does not check for a function but for a
    #   define to exist. Consider a usage like:
    #
    #    AC_CHECK_DEFINE(__STRICT_ANSI__, CFLAGS="$CFLAGS -D_XOPEN_SOURCE=500")
    #
    # LICENSE
    #
    #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
    #
    #   This program is free software; you can redistribute it and/or modify it
    #   under the terms of the GNU General Public License as published by the
    #   Free Software Foundation; either version 3 of the License, or (at your
    #   option) any later version.
    #
    #   This program 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 General
    #   Public License for more details.
    #
    #   You should have received a copy of the GNU General Public License along
    #   with this program. If not, see <https://www.gnu.org/licenses/>.
    #
    #   As a special exception, the respective Autoconf Macro's copyright owner
    #   gives unlimited permission to copy, distribute and modify the configure
    #   scripts that are the output of Autoconf when processing the Macro. You
    #   need not follow the terms of the GNU General Public License when using
    #   or distributing such scripts, even though portions of the text of the
    #   Macro appear in them. The GNU General Public License (GPL) does govern
    #   all other use of the material that constitutes the Autoconf Macro.
    #
    #   This special exception to the GPL applies to versions of the Autoconf
    #   Macro released by the Autoconf Archive. When you make and distribute a
    #   modified version of the Autoconf Macro, you may extend this special
    #   exception to the GPL to apply to your modified version as well.
    
    #serial 9
    
    AU_ALIAS([AC_CHECK_DEFINED], [AC_CHECK_DEFINE])
    AC_DEFUN([AC_CHECK_DEFINE],[
    AS_VAR_PUSHDEF([ac_var],[ac_cv_defined_$1])dnl
    AC_CACHE_CHECK([for $1 defined], ac_var,
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
      #ifdef $1
      int ok;
      #else
      choke me
      #endif
    ]])],[AS_VAR_SET(ac_var, yes)],[AS_VAR_SET(ac_var, no)]))
    AS_IF([test AS_VAR_GET(ac_var) != "no"], [$2], [$3])dnl
    AS_VAR_POPDEF([ac_var])dnl
    ])
    
    AU_ALIAS([AX_CHECK_DEFINED], [AX_CHECK_DEFINE])
    AC_DEFUN([AX_CHECK_DEFINE],[
    AS_VAR_PUSHDEF([ac_var],[ac_cv_defined_$2_$1])dnl
    AC_CACHE_CHECK([for $2 defined in $1], ac_var,
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <$1>]], [[
      #ifdef $2
      int ok;
      #else
      choke me
      #endif
    ]])],[AS_VAR_SET(ac_var, yes)],[AS_VAR_SET(ac_var, no)]))
    AS_IF([test AS_VAR_GET(ac_var) != "no"], [$3], [$4])dnl
    AS_VAR_POPDEF([ac_var])dnl
    ])
    
    AC_DEFUN([AX_CHECK_FUNC],
    [AS_VAR_PUSHDEF([ac_var], [ac_cv_func_$2])dnl
    AC_CACHE_CHECK([for $2], ac_var,
    dnl AC_LANG_FUNC_LINK_TRY
    [AC_LINK_IFELSE([AC_LANG_PROGRAM([$1
                    #undef $2
                    char $2 ();],[
                    char (*f) () = $2;
                    return f != $2; ])],
                    [AS_VAR_SET(ac_var, yes)],
                    [AS_VAR_SET(ac_var, no)])])
    AS_IF([test AS_VAR_GET(ac_var) = yes], [$3], [$4])dnl
    AS_VAR_POPDEF([ac_var])dnl
    ])# AC_CHECK_FUNC

Cache object: fecb623038b0d87d515c5fb014a0cf27