1 # =========================================================================== 2 # https://www.gnu.org/software/autoconf-archive/ax_c___attribute__.html 3 # =========================================================================== 4 # 5 # SYNOPSIS 6 # 7 # AX_C___ATTRIBUTE__ 8 # 9 # DESCRIPTION 10 # 11 # Provides a test for the compiler support of __attribute__ extensions. 12 # Defines HAVE___ATTRIBUTE__ if it is found. 13 # 14 # LICENSE 15 # 16 # Copyright (c) 2008 Stepan Kasal <skasal (a] redhat.com> 17 # Copyright (c) 2008 Christian Haggstrom 18 # Copyright (c) 2008 Ryan McCabe <ryan (a] numb.org> 19 # 20 # This program is free software; you can redistribute it and/or modify it 21 # under the terms of the GNU General Public License as published by the 22 # Free Software Foundation; either version 2 of the License, or (at your 23 # option) any later version. 24 # 25 # This program is distributed in the hope that it will be useful, but 26 # WITHOUT ANY WARRANTY; without even the implied warranty of 27 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 28 # Public License for more details. 29 # 30 # You should have received a copy of the GNU General Public License along 31 # with this program. If not, see <https://www.gnu.org/licenses/>. 32 # 33 # As a special exception, the respective Autoconf Macro's copyright owner 34 # gives unlimited permission to copy, distribute and modify the configure 35 # scripts that are the output of Autoconf when processing the Macro. You 36 # need not follow the terms of the GNU General Public License when using 37 # or distributing such scripts, even though portions of the text of the 38 # Macro appear in them. The GNU General Public License (GPL) does govern 39 # all other use of the material that constitutes the Autoconf Macro. 40 # 41 # This special exception to the GPL applies to versions of the Autoconf 42 # Macro released by the Autoconf Archive. When you make and distribute a 43 # modified version of the Autoconf Macro, you may extend this special 44 # exception to the GPL to apply to your modified version as well. 45 46 #serial 9 47 48 AC_DEFUN([AX_C___ATTRIBUTE__], [ 49 AC_CACHE_CHECK([for __attribute__], [ax_cv___attribute__], 50 [AC_COMPILE_IFELSE( 51 [AC_LANG_PROGRAM( 52 [[#include <stdlib.h> 53 static void foo(void) __attribute__ ((unused)); 54 static void 55 foo(void) { 56 exit(1); 57 } 58 ]], [])], 59 [ax_cv___attribute__=yes], 60 [ax_cv___attribute__=no] 61 ) 62 ]) 63 if test "$ax_cv___attribute__" = "yes"; then 64 AC_DEFINE([HAVE___ATTRIBUTE__], 1, [define if your compiler has __attribute__]) 65 fi 66 ]) 67
