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      1 # ===========================================================================
      2 #       http://www.gnu.org/software/autoconf-archive/ax_gcc_option.html
      3 # ===========================================================================
      4 #
      5 # OBSOLETE MACRO
      6 #
      7 #   Deprecated in favor of AX_C_CHECK_FLAG, AX_CXX_CHECK_FLAG,
      8 #   AX_CPP_CHECK_FLAG, AX_CXXCPP_CHECK_FLAG and AX_LD_CHECK_FLAG.
      9 #
     10 # SYNOPSIS
     11 #
     12 #   AX_GCC_OPTION(OPTION,EXTRA-OPTIONS,TEST-PROGRAM,ACTION-IF-SUCCESSFUL,ACTION-IF-NOT-SUCCESFUL)
     13 #
     14 # DESCRIPTION
     15 #
     16 #   AX_GCC_OPTION checks wheter gcc accepts the passed OPTION. If it accepts
     17 #   the OPTION then ACTION-IF-SUCCESSFUL will be executed, otherwise
     18 #   ACTION-IF-UNSUCCESSFUL.
     19 #
     20 #   A typical usage should be the following one:
     21 #
     22 #     AX_GCC_OPTION([-fomit-frame-pointer],[],[],[
     23 #       AC_MSG_NOTICE([The option is supported])],[
     24 #       AC_MSG_NOTICE([No luck this time])
     25 #     ])
     26 #
     27 #   The macro doesn't discriminate between languages so, if you are testing
     28 #   for an option that works for C++ but not for C you should use '-x c++'
     29 #   as EXTRA-OPTIONS:
     30 #
     31 #     AX_GCC_OPTION([-fno-rtti],[-x c++],[],[ ... ],[ ... ])
     32 #
     33 #   OPTION is tested against the following code:
     34 #
     35 #     int main()
     36 #     {
     37 #             return 0;
     38 #     }
     39 #
     40 #   The optional TEST-PROGRAM comes handy when the default main() is not
     41 #   suited for the option being checked
     42 #
     43 #   So, if you need to test for -fstrict-prototypes option you should
     44 #   probably use the macro as follows:
     45 #
     46 #     AX_GCC_OPTION([-fstrict-prototypes],[-x c++],[
     47 #       int main(int argc, char ** argv)
     48 #       {
     49 #               (void) argc;
     50 #               (void) argv;
     51 #
     52 #               return 0;
     53 #       }
     54 #     ],[ ... ],[ ... ])
     55 #
     56 #   Note that the macro compiles but doesn't link the test program so it is
     57 #   not suited for checking options that are passed to the linker, like:
     58 #
     59 #     -Wl,-L<a-library-path>
     60 #
     61 #   In order to avoid such kind of problems you should think about usinguse
     62 #   the AX_*_CHECK_FLAG family macros
     63 #
     64 # LICENSE
     65 #
     66 #   Copyright (c) 2008 Francesco Salvestrini <salvestrini (a] users.sourceforge.net>
     67 #   Copyright (c) 2008 Bogdan Drozdowski <bogdandr (a] op.pl>
     68 #
     69 #   This program is free software; you can redistribute it and/or modify it
     70 #   under the terms of the GNU General Public License as published by the
     71 #   Free Software Foundation; either version 2 of the License, or (at your
     72 #   option) any later version.
     73 #
     74 #   This program is distributed in the hope that it will be useful, but
     75 #   WITHOUT ANY WARRANTY; without even the implied warranty of
     76 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
     77 #   Public License for more details.
     78 #
     79 #   You should have received a copy of the GNU General Public License along
     80 #   with this program. If not, see <http://www.gnu.org/licenses/>.
     81 #
     82 #   As a special exception, the respective Autoconf Macro's copyright owner
     83 #   gives unlimited permission to copy, distribute and modify the configure
     84 #   scripts that are the output of Autoconf when processing the Macro. You
     85 #   need not follow the terms of the GNU General Public License when using
     86 #   or distributing such scripts, even though portions of the text of the
     87 #   Macro appear in them. The GNU General Public License (GPL) does govern
     88 #   all other use of the material that constitutes the Autoconf Macro.
     89 #
     90 #   This special exception to the GPL applies to versions of the Autoconf
     91 #   Macro released by the Autoconf Archive. When you make and distribute a
     92 #   modified version of the Autoconf Macro, you may extend this special
     93 #   exception to the GPL to apply to your modified version as well.
     94 
     95 #serial 13
     96 
     97 AC_DEFUN([AX_GCC_OPTION], [
     98   AC_REQUIRE([AC_PROG_CC])
     99 
    100   AC_MSG_CHECKING([if gcc accepts $1 option])
    101 
    102   AS_IF([ test "x$GCC" = "xyes" ],[
    103     AS_IF([ test -z "$3" ],[
    104       ax_gcc_option_test="int main()
    105 {
    106 	return 0;
    107 }"
    108     ],[
    109       ax_gcc_option_test="$3"
    110     ])
    111 
    112     # Dump the test program to file
    113     cat <<EOF > conftest.c
    114 $ax_gcc_option_test
    115 EOF
    116 
    117     # Dump back the file to the log, useful for debugging purposes
    118     AC_TRY_COMMAND(cat conftest.c 1>&AS_MESSAGE_LOG_FD)
    119 
    120     AS_IF([ AC_TRY_COMMAND($CC $2 $1 -c conftest.c 1>&AS_MESSAGE_LOG_FD) ],[
    121 		AC_MSG_RESULT([yes])
    122 	$4
    123     ],[
    124 		AC_MSG_RESULT([no])
    125 	$5
    126     ])
    127   ],[
    128     AC_MSG_RESULT([no gcc available])
    129   ])
    130 ])
    131