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ax_cflags_strict_prototypes

Synopsis

AX_CFLAGS_STRICT_PROTOTYPES [(shellvar [,default, [A/NA]]

Description

Try to find a compiler option that requires strict prototypes.

The sanity check is done by looking at sys/signal.h which has a set of macro-definitions SIG_DFL and SIG_IGN that are cast to the local signal-handler type. If that signal-handler type is not fully qualified then the system headers are not seen as strictly prototype clean.

For the GNU CC compiler it will be -fstrict-prototypes -Wstrict-prototypes The result is added to the shellvar being CFLAGS by default.

DEFAULTS:

 - $1 shell-variable-to-add-to : CFLAGS
 - $2 add-value-if-not-found : nothing
 - $3 action-if-found : add value to shellvariable
 - $4 action-if-not-found : nothing

Author

Guido U. Draheim <guidod@gmx.de>

Last Modified

2006-12-12

M4 Source Code

AC_DEFUN([AX_CFLAGS_STRICT_PROTOTYPES],[dnl
AS_VAR_PUSHDEF([FLAGS],[CFLAGS])dnl
AS_VAR_PUSHDEF([VAR],[ac_cv_cflags_strict_prototypes])dnl
AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for strict prototypes],
VAR,[VAR="no, unknown"
 AC_LANG_SAVE
 AC_LANG_C
 ac_save_[]FLAGS="$[]FLAGS"
for ac_arg dnl
in "-pedantic % -fstrict-prototypes -Wstrict-prototypes" dnl   GCC
   "-pedantic % -Wstrict-prototypes" dnl try to warn atleast
   "-pedantic % -Wmissing-prototypes" dnl or another warning
   "-pedantic % -Werror-implicit-function-declaration" dnl
   "-pedantic % -Wimplicit-function-declaration" dnl
   #
do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
   AC_TRY_COMPILE([],[return 0;],
   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
done
case ".$VAR" in
   .|.no|.no,*) ;;
   *) # sanity check with signal() from sys/signal.h
    cp config.log config.tmp
    AC_TRY_COMPILE([#include <signal.h>],[
    if (signal (SIGINT, SIG_IGN) == SIG_DFL) return 1;
    if (signal (SIGINT, SIG_IGN) != SIG_DFL) return 2;],
    dnl the original did use test -n `$CC testprogram.c`
    [if test `diff config.log config.tmp | grep -i warning | wc -l` != 0
then if test `diff config.log config.tmp | grep -i warning | wc -l` != 1
then VAR="no, suppressed, signal.h," ; fi ; fi],
    [VAR="no, suppressed, signal.h"])
    rm config.tmp
  ;;
esac
 FLAGS="$ac_save_[]FLAGS"
 AC_LANG_RESTORE
])
case ".$VAR" in
     .ok|.ok,*) m4_ifvaln($3,$3) ;;
   .|.no|.no,*) m4_ifvaln($4,$4,[m4_ifval($2,[
        AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $2"])
                      m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $2"])]) ;;
   *) 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_STRICT_PROTOTYPES],[dnl
AS_VAR_PUSHDEF([FLAGS],[CXXFLAGS])dnl
AS_VAR_PUSHDEF([VAR],[ac_cv_cxxflags_strict_prototypes])dnl
AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for strict prototypes],
VAR,[VAR="no, unknown"
 AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 ac_save_[]FLAGS="$[]FLAGS"
for ac_arg dnl
in "-pedantic -Werror % -fstrict-prototypes -Wstrict-prototypes" dnl   GCC
   "-pedantic -Werror % -Wstrict-prototypes" dnl try to warn atleast
   "-pedantic -Werror % -Wmissing-prototypes" dnl try to warn atleast
   "-pedantic -Werror % -Werror-implicit-function-declaration" dnl
   "-pedantic -Werror % -Wimplicit-function-declaration" dnl
   "-pedantic % -Wstrict-prototypes %% no, unsupported in C++" dnl oops
   #
do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
   AC_TRY_COMPILE([],[return 0;],
   [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
done
case ".$VAR" in
   .|.no|.no,*) ;;
   *) # sanity check with signal() from sys/signal.h
    cp config.log config.tmp
    AC_TRY_COMPILE([#include <signal.h>],[
    if (signal (SIGINT, SIG_IGN) == SIG_DFL) return 1;
    if (signal (SIGINT, SIG_IGN) != SIG_DFL) return 2;],
    dnl the original did use test -n `$CC testprogram.c`
    [if test `diff config.log config.tmp | grep -i warning | wc -l` != 0
then if test `diff config.log config.tmp | grep -i warning | wc -l` != 1
then VAR="no, suppressed, signal.h," ; fi ; fi],
    [VAR="no, suppressed, signal.h"])
    rm config.tmp
  ;;
esac
 FLAGS="$ac_save_[]FLAGS"
 AC_LANG_RESTORE
])
case ".$VAR" in
     .ok|.ok,*) m4_ifvaln($3,$3) ;;
   .|.no|.no,*) m4_ifvaln($4,$4,[m4_ifval($2,[
        AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $2"])
                      m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $2"])]) ;;
   *) 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
])

License

Copyright © 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.