#!/usr/bin/perl

# GPL Paul Slootman <paul@wurtel.demon.nl> 1998
#     Peter Marschall <peter@adpm.de> 2012
#
# script to convert .config as generated by 'make menuconfig' into
# scripts/autoconf.h ans scripts/autoconf.mk, so that one can edit
# .config by hand and then non-interactively create a configuration
# ready for building. Useful for package building (I'm thinking Debian
# or Red Hat here).

open(IN,  "<.config")  or  die "Can't open .config: $!\n";
open(OUT_H, ">scripts/autoconf.h")  or  die "Can't open scripts/autoconf.h: $!\n";
open(OUT_MK, ">scripts/autoconf.mk")  or  die "Can't open scripts/autoconf.mk: $!\n";

while (my $line = <IN>) {
    chomp($line);

    if ($line =~ /^#\s*$/o) {				# empty comment line; ignore for autoconf.h
        printf OUT_MK "%s\n", $line;
    }
    elsif ($line =~ /^\s*$/o) {				# empty line; echo
        print OUT_H "\n";
        printf OUT_MK "%s\n", $line;
    }
    elsif ($line =~ /^# ([^\s]+) is not set/o) {	# unset variables
        my $var = $1;

        printf OUT_H "#undef  %s\n", $var;
        printf OUT_MK "%s\n", $line;
    }
    elsif ($line =~ /^#\s+([^\s].*)\s*/o) {		# comment
        my $comment = $1;

        $line =~ s/(make menuconfig)/'$1' and '$0'/
            if ($line =~/Automatically generated by/);

        printf OUT_H "/*\n * %s\n */\n", $comment;
        print OUT_H "#define AUTOCONF_INCLUDED\n"
             if ($line =~/Automatically generated by/);
        printf OUT_MK "# %s\n", $comment;
    }
    elsif ($line =~ /(\w+)=(.*)/o) {			# assignment
        my ($var,$val) = ($1,$2);

        if ($val =~ /^(?:y|yes|true|on)$/io) {		# boolean TRUE value
            printf OUT_H "#define %-32s 1\n", $var;
            printf OUT_MK "%-32s = y\n", $var;
        }
        elsif ($val =~ /^(?:n|no|false|off)$/io) {	# boolean FALSE value; like unset variable
            printf OUT_H "#undef  %s\n", $var;
            printf OUT_MK "# %s is not set\n", $var;
        }
        elsif ($val =~ /^(['"])(.*)\1$/o) {		# string value
            my $str = $2;

            printf OUT_H "#define %-32s \"%s\"\n", $var, $str;
            printf OUT_MK "%-32s = %s\n", $var, $str;
        }
        elsif ($val =~ /^(-?\d+)$/) {			# numeric value
            my $num = $1;

            printf OUT_H "#define %-32s (%s)\n", $var, $num;
            printf OUT_MK "%-32s = %s\n", $var, $num;
        }
        else {
            die "Unexpected input in .config at line $.: $line\n";
        }
    }
    else {
        die "Unexpected input in .config at line $.: $line\n";
    }
}

close(IN);
close(OUT_H);
close(OUT_MK);
exit(0);