#!/usr/bin/env python

# Copyright (c) 2018, Ulf Magnusson
# SPDX-License-Identifier: ISC

# Works like 'make allnoconfig'. Verified by the test suite to generate
# identical output to 'make allnoconfig' for all ARCHes.
#
# See the examples/allnoconfig_walk.py example script for another variant.
#
# The default output filename is '.config'. A different filename can be passed
# in the KCONFIG_CONFIG environment variable.
#
# Usage for the Linux kernel:
#
#   $ make [ARCH=<arch>] scriptconfig SCRIPT=Kconfiglib/allnoconfig.py

import kconfiglib

def main():
    kconf = kconfiglib.standard_kconfig()

    # Avoid warnings that would otherwise get printed by Kconfiglib for the
    # following:
    #
    # 1. Assigning a value to a symbol without a prompt, which never has any
    #    effect
    #
    # 2. Assigning values invalid for the type (only bool/tristate symbols
    #    accept 0/1/2, for n/m/y). The assignments will be ignored for other
    #    symbol types, which is what we want.
    kconf.disable_warnings()
    for sym in kconf.unique_defined_syms:
        sym.set_value(2 if sym.is_allnoconfig_y else 0)
    kconf.enable_warnings()

    kconfiglib.load_allconfig(kconf, "allno.config")

    kconf.write_config(kconfiglib.standard_config_filename())

if __name__ == "__main__":
    main()