construct/m4/charybdis.m4

AC_DEFUN([AC_DEFINE_DIR], [
  test "x$prefix" = xNONE && prefix="$ac_default_prefix"
  test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
  last_ac_define_dir=`eval echo [$]$2`
  ac_define_dir=`eval echo [$]last_ac_define_dir`
  ac_define_dir_counter=0
  while test "x[$]last_ac_define_dir" != "x[$]ac_define_dir"; do
    last_ac_define_dir="[$]ac_define_dir"
    ac_define_dir=`eval echo [$]last_ac_define_dir`
    AS_VAR_ARITH([ac_define_dir_counter], [$ac_define_dir_counter + 1])
    AS_VAR_IF([ac_define_dir_counter], [128],
	[AC_MSG_ERROR([detected recusive directory expansion when expanding $1=[$]$2: [$]ac_define_dir])
	break])
  done
  $1="$ac_define_dir"
  AC_SUBST($1)
  ifelse($3, ,
    AC_DEFINE_UNQUOTED($1, "$ac_define_dir"),
    AC_DEFINE_UNQUOTED($1, "$ac_define_dir", $3))
])

AC_DEFUN([AC_SUBST_DIR], [
        ifelse($2,,,$1="[$]$2")
        $1=`(
            test "x$prefix" = xNONE && prefix="$ac_default_prefix"
            test "x$exec_prefix" = xNONE && exec_prefix="${prefix}"
            eval echo \""[$]$1"\"
        )`
        AC_SUBST($1)
])

dnl CHARYBDIS_C_GCC_TRY_FLAGS(<warnings>,<cachevar>)
AC_DEFUN([CHARYBDIS_C_GCC_TRY_FLAGS],[
 AC_MSG_CHECKING([GCC flag(s) $1])
 if test "${GCC-no}" = yes
 then
  AC_CACHE_VAL($2,[
   oldcflags="${CFLAGS-}"
   CFLAGS="${CFLAGS-} ${CWARNS} $1 -Werror"
   AC_TRY_COMPILE([
#include <string.h>
#include <stdio.h>
int main(void);
],[
    (void)strcmp("a","b"); fprintf(stdout,"test ok\n");
], [$2=yes], [$2=no])
   CFLAGS="${oldcflags}"])
  if test "x$$2" = xyes; then
   CWARNS="${CWARNS}$1 "
   AC_MSG_RESULT(ok)  
  else
   $2=''
   AC_MSG_RESULT(no)
  fi
 else
  AC_MSG_RESULT(no, not using GCC)
 fi
])