##### http://autoconf-archive.cryp.to/ax_cflags_gcc_option.html

#

# SYNOPSIS

#

#   AX_CFLAGS_GCC_OPTION (optionflag [,[shellvar][,[A][,[NA]]])

#

# DESCRIPTION

#

#   AX_CFLAGS_GCC_OPTION(-fvomit-frame) would show a message as like

#   "checking CFLAGS for gcc -fvomit-frame ... yes" and adds the

#   optionflag to CFLAGS if it is understood. You can override the

#   shellvar-default of CFLAGS of course. The order of arguments stems

#   from the explicit macros like AX_CFLAGS_WARN_ALL.

#

#   The cousin AX_CXXFLAGS_GCC_OPTION would check for an option to add

#   to CXXFLAGS - and it uses the autoconf setup for C++ instead of C

#   (since it is possible to use different compilers for C and C++).

#

#   The macro is a lot simpler than any special AX_CFLAGS_* macro (or

#   ac_cxx_rtti.m4 macro) but allows to check for arbitrary options.

#   However, if you use this macro in a few places, it would be great

#   if you would make up a new function-macro and submit it to the

#   ac-archive.

#

#     - $1 option-to-check-for : required ("-option" as non-value)

#     - $2 shell-variable-to-add-to : CFLAGS (or CXXFLAGS in the other case)

#     - $3 action-if-found : add value to shellvariable

#     - $4 action-if-not-found : nothing

#

#   note: in earlier versions, $1-$2 were swapped. We try to detect the

#   situation and accept a $2=~/-/ as being the old

#   option-to-check-for.

#

#   also: there are other variants that emerged from the original macro

#   variant which did just test an option to be possibly added.

#   However, some compilers accept an option silently, or possibly for

#   just another option that was not intended. Therefore, we have to do

#   a generic test for a compiler family. For gcc we check "-pedantic"

#   being accepted which is also understood by compilers who just want

#   to be compatible with gcc even when not being made from gcc

#   sources.

#

#   see also:

#

#         AX_CFLAGS_SUN_OPTION               AX_CFLAGS_HPUX_OPTION

#         AX_CFLAGS_AIX_OPTION               AX_CFLAGS_IRIX_OPTION

#

# LAST MODIFICATION

#

#   2006-12-12

#

# COPYLEFT

#

#   Copyright (c) 2006 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 2 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, write to the Free Software

#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA

#   02111-1307, USA.

#

#   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 Macro 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.

AC_DEFUN([AX_CFLAGS_GCC_OPTION_OLD], [dnl

AS_VAR_PUSHDEF([FLAGS],[CFLAGS])dnl

AS_VAR_PUSHDEF([VAR],[ac_cv_cflags_gcc_option_$2])dnl

AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for gcc m4_ifval($2,$2,-option)],

VAR,[VAR="no, unknown"

 AC_LANG_SAVE

 AC_LANG_C

 ac_save_[]FLAGS="$[]FLAGS"

for ac_arg dnl

in "-pedantic -Werror % m4_ifval($2,$2,-option)"  dnl   GCC

   "-pedantic % m4_ifval($2,$2,-option) %% no, obsolete"  dnl new GCC

   #

do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`

   AC_TRY_COMPILE([],[return 0;],

   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])

done

 FLAGS="$ac_save_[]FLAGS"

 AC_LANG_RESTORE

])

case ".$VAR" in

     .ok|.ok,*) m4_ifvaln($3,$3) ;;

   .|.no|.no,*) m4_ifvaln($4,$4) ;;

   *) m4_ifvaln($3,$3,[

   if echo " $[]m4_ifval($1,$1,FLAGS) " | grep " $VAR " 2>&1 >/dev/null

   then AC_RUN_LOG([: m4_ifval($1,$1,FLAGS) does contain $VAR])

   else AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"])

                      m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"

   fi ]) ;;

esac

AS_VAR_POPDEF([VAR])dnl

AS_VAR_POPDEF([FLAGS])dnl

])

dnl the only difference - the LANG selection... and the default FLAGS

AC_DEFUN([AX_CXXFLAGS_GCC_OPTION_OLD], [dnl

AS_VAR_PUSHDEF([FLAGS],[CXXFLAGS])dnl

AS_VAR_PUSHDEF([VAR],[ac_cv_cxxflags_gcc_option_$2])dnl

AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for gcc m4_ifval($2,$2,-option)],

VAR,[VAR="no, unknown"

 AC_LANG_SAVE

 AC_LANG_CPLUSPLUS

 ac_save_[]FLAGS="$[]FLAGS"

for ac_arg dnl

in "-pedantic -Werror % m4_ifval($2,$2,-option)"  dnl   GCC

   "-pedantic % m4_ifval($2,$2,-option) %% no, obsolete"  dnl new GCC

   #

do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`

   AC_TRY_COMPILE([],[return 0;],

   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])

done

 FLAGS="$ac_save_[]FLAGS"

 AC_LANG_RESTORE

])

case ".$VAR" in

     .ok|.ok,*) m4_ifvaln($3,$3) ;;

   .|.no|.no,*) m4_ifvaln($4,$4) ;;

   *) m4_ifvaln($3,$3,[

   if echo " $[]m4_ifval($1,$1,FLAGS) " | grep " $VAR " 2>&1 >/dev/null

   then AC_RUN_LOG([: m4_ifval($1,$1,FLAGS) does contain $VAR])

   else AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"])

                      m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"

   fi ]) ;;

esac

AS_VAR_POPDEF([VAR])dnl

AS_VAR_POPDEF([FLAGS])dnl

])

dnl -------------------------------------------------------------------------

AC_DEFUN([AX_CFLAGS_GCC_OPTION_NEW], [dnl

AS_VAR_PUSHDEF([FLAGS],[CFLAGS])dnl

AS_VAR_PUSHDEF([VAR],[ac_cv_cflags_gcc_option_$1])dnl

AC_CACHE_CHECK([m4_ifval($2,$2,FLAGS) for gcc m4_ifval($1,$1,-option)],

VAR,[VAR="no, unknown"

 AC_LANG_SAVE

 AC_LANG_C

 ac_save_[]FLAGS="$[]FLAGS"

for ac_arg dnl

in "-pedantic -Werror % m4_ifval($1,$1,-option)"  dnl   GCC

   "-pedantic % m4_ifval($1,$1,-option) %% no, obsolete"  dnl new GCC

   #

do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`

   AC_TRY_COMPILE([],[return 0;],

   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])

done

 FLAGS="$ac_save_[]FLAGS"

 AC_LANG_RESTORE

])

case ".$VAR" in

     .ok|.ok,*) m4_ifvaln($3,$3) ;;

   .|.no|.no,*) m4_ifvaln($4,$4) ;;

   *) m4_ifvaln($3,$3,[

   if echo " $[]m4_ifval($2,$2,FLAGS) " | grep " $VAR " 2>&1 >/dev/null

   then AC_RUN_LOG([: m4_ifval($2,$2,FLAGS) does contain $VAR])

   else AC_RUN_LOG([: m4_ifval($2,$2,FLAGS)="$m4_ifval($2,$2,FLAGS) $VAR"])

                      m4_ifval($2,$2,FLAGS)="$m4_ifval($2,$2,FLAGS) $VAR"

   fi ]) ;;

esac

AS_VAR_POPDEF([VAR])dnl

AS_VAR_POPDEF([FLAGS])dnl

])

dnl the only difference - the LANG selection... and the default FLAGS

AC_DEFUN([AX_CXXFLAGS_GCC_OPTION_NEW], [dnl

AS_VAR_PUSHDEF([FLAGS],[CXXFLAGS])dnl

AS_VAR_PUSHDEF([VAR],[ac_cv_cxxflags_gcc_option_$1])dnl

AC_CACHE_CHECK([m4_ifval($2,$2,FLAGS) for gcc m4_ifval($1,$1,-option)],

VAR,[VAR="no, unknown"

 AC_LANG_SAVE

 AC_LANG_CPLUSPLUS

 ac_save_[]FLAGS="$[]FLAGS"

for ac_arg dnl

in "-pedantic -Werror % m4_ifval($1,$1,-option)"  dnl   GCC

   "-pedantic % m4_ifval($1,$1,-option) %% no, obsolete"  dnl new GCC

   #

do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`

   AC_TRY_COMPILE([],[return 0;],

   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])

done

 FLAGS="$ac_save_[]FLAGS"

 AC_LANG_RESTORE

])

case ".$VAR" in

     .ok|.ok,*) m4_ifvaln($3,$3) ;;

   .|.no|.no,*) m4_ifvaln($4,$4) ;;

   *) m4_ifvaln($3,$3,[

   if echo " $[]m4_ifval($2,$2,FLAGS) " | grep " $VAR " 2>&1 >/dev/null

   then AC_RUN_LOG([: m4_ifval($2,$2,FLAGS) does contain $VAR])

   else AC_RUN_LOG([: m4_ifval($2,$2,FLAGS)="$m4_ifval($2,$2,FLAGS) $VAR"])

                      m4_ifval($2,$2,FLAGS)="$m4_ifval($2,$2,FLAGS) $VAR"

   fi ]) ;;

esac

AS_VAR_POPDEF([VAR])dnl

AS_VAR_POPDEF([FLAGS])dnl

])

AC_DEFUN([AX_CFLAGS_GCC_OPTION],[ifelse(m4_bregexp([$2],[-]),-1,

[AX_CFLAGS_GCC_OPTION_NEW($@)],[AX_CFLAGS_GCC_OPTION_OLD($@)])])

AC_DEFUN([AX_CXXFLAGS_GCC_OPTION],[ifelse(m4_bregexp([$2],[-]),-1,

[AX_CXXFLAGS_GCC_OPTION_NEW($@)],[AX_CXXFLAGS_GCC_OPTION_OLD($@)])])