# Goals stdlib prelude.
# Copyright (C) 2019 Richard W.M. Jones
# Copyright (C) 2019 Red Hat Inc.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# This file is included first and automatically in all Goalfiles
# (unless you use --no-prelude).  It contains standard goals and
# tactics.

# The only tactic that ‘make’ has.
tactic *file (filename) = {
    # Rebuild if the target file doesn't exist at all.
    test -f %filename || exit 99

    # Otherwise rebuild if it is older than any dependency.
    for f in %<; do
        test %filename -ot "$f" && exit 99 || exit 0
    done
}

# This is a simpler tactic than the above since it will
# rebuild if the file is missing, but not if it is older.
tactic *exists (filename) = {
    test -f %filename || exit 99
}