build/aclocal/ax_gcc_option.m4

   1 # ===========================================================================
   2 #             http://autoconf-archive.cryp.to/ax_gcc_option.html
   3 # ===========================================================================
   4 #
   5 # SYNOPSIS
   6 #
   7 #   AX_GCC_OPTION(OPTION,EXTRA-OPTIONS,TEST-PROGRAM,ACTION-IF-SUCCESSFUL,ACTION-IF-NOT-SUCCESFUL)
   8 #
   9 # DESCRIPTION
  10 #
  11 #   AX_GCC_OPTION checks wheter gcc accepts the passed OPTION. If it accepts
  12 #   the OPTION then ACTION-IF-SUCCESSFUL will be executed, otherwise
  13 #   ACTION-IF-UNSUCCESSFUL.
  14 #
  15 #   NOTE: This macro will be obsoleted by AX_C_CHECK_FLAG AX_CXX_CHECK_FLAG,
  16 #   AX_CPP_CHECK_FLAG, AX_CXXCPP_CHECK_FLAG and AX_LD_CHECK_FLAG.
  17 #
  18 #   A typical usage should be the following one:
  19 #
  20 #     AX_GCC_OPTION([-fomit-frame-pointer],[],[],[
  21 #       AC_MSG_NOTICE([The option is supported])],[
  22 #       AC_MSG_NOTICE([No luck this time])
  23 #     ])
  24 #
  25 #   The macro doesn't discriminate between languages so, if you are testing
  26 #   for an option that works for C++ but not for C you should use '-x c++'
  27 #   as EXTRA-OPTIONS:
  28 #
  29 #     AX_GCC_OPTION([-fno-rtti],[-x c++],[],[ ... ],[ ... ])
  30 #
  31 #   OPTION is tested against the following code:
  32 #
  33 #     int main()
  34 #     {
  35 #             return 0;
  36 #     }
  37 #
  38 #   The optional TEST-PROGRAM comes handy when the default main() is not
  39 #   suited for the option being checked
  40 #
  41 #   So, if you need to test for -fstrict-prototypes option you should
  42 #   probably use the macro as follows:
  43 #
  44 #     AX_GCC_OPTION([-fstrict-prototypes],[-x c++],[
  45 #       int main(int argc, char ** argv)
  46 #       {
  47 #               (void) argc;
  48 #               (void) argv;
  49 #
  50 #               return 0;
  51 #       }
  52 #     ],[ ... ],[ ... ])
  53 #
  54 #   Note that the macro compiles but doesn't link the test program so it is
  55 #   not suited for checking options that are passed to the linker, like:
  56 #
  57 #     -Wl,-L<a-library-path>
  58 #
  59 #   In order to avoid such kind of problems you should think about usinguse
  60 #   the AX_*_CHECK_FLAG family macros
  61 #
  62 # LAST MODIFICATION
  63 #
  64 #   2008-04-12
  65 #
  66 # COPYLEFT
  67 #
  68 #   Copyright (c) 2008 Francesco Salvestrini <salvestrini@users.sourceforge.net>
  69 #   Copyright (c) 2008 Bogdan Drozdowski <bogdandr@op.pl>
  70 #
  71 #   This program is free software; you can redistribute it and/or modify it
  72 #   under the terms of the GNU General Public License as published by the
  73 #   Free Software Foundation; either version 2 of the License, or (at your
  74 #   option) any later version.
  75 #
  76 #   This program is distributed in the hope that it will be useful, but
  77 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  78 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  79 #   Public License for more details.
  80 #
  81 #   You should have received a copy of the GNU General Public License along
  82 #   with this program. If not, see <http://www.gnu.org/licenses/>.
  83 #
  84 #   As a special exception, the respective Autoconf Macro's copyright owner
  85 #   gives unlimited permission to copy, distribute and modify the configure
  86 #   scripts that are the output of Autoconf when processing the Macro. You
  87 #   need not follow the terms of the GNU General Public License when using
  88 #   or distributing such scripts, even though portions of the text of the
  89 #   Macro appear in them. The GNU General Public License (GPL) does govern
  90 #   all other use of the material that constitutes the Autoconf Macro.
  91 #
  92 #   This special exception to the GPL applies to versions of the Autoconf
  93 #   Macro released by the Autoconf Macro Archive. When you make and
  94 #   distribute a modified version of the Autoconf Macro, you may extend this
  95 #   special exception to the GPL to apply to your modified version as well.
  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 ])