Hi At the moment I have a --with argument that is off by default and I would like to change this so that is on by default and users will need to configure using --without-arg or --with-arg=no to disable the feature, essentially adding a lot of strict warning flags. I currently define the option using: AC_DEFUN([LAL_WITH_GCC_FLAGS], [AC_ARG_WITH( [gcc_flags], AC_HELP_STRING([--with-gcc-flags],[turn on strict gcc warning flags]), [ if test -n "${with_gcc_flags}" then lal_gcc_flags="-g3 -O4 -Wall -W -Wmissing-prototypes -Wstrict-prototypes -Wshadow -Wpointer-arith -Wcast-qual -Wcast-align -Wwrite-strings -fno-common -Wnested-externs -Wno-format-zero-length" case $host_cpu-$host_os in *i386-darwin*) lal_gcc_flags="${lal_gcc_flags} -pedantic" ;; *) lal_gcc_flags="${lal_gcc_flags} -pedantic-errors" ;; esac else lal_gcc_flags="" fi ], [ lal_gcc_flags="" ] ) ]) and then call it in configure.ac with: LAL_WITH_GCC_FLAGS then just before AC_OUTPUT, so that the flags don't interfere with compiler tests, I have the following: if test "$GCC" = yes; then CFLAGS="$CFLAGS $lal_gcc_flags" fi So to modify this to be on by default I am planning to just add the flags in the "action-if-not-given" section of AC_ARG_WITH? Is this the best way to accomplish this or is there a better way to use default with args? Cheers Adam _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf