linux-config-merge

#!/usr/bin/perl -w

#
# © Copyright 2008 by Geert Uytterhoeven
#
# This file is subject to the terms and conditions of the GNU General Public
# License.
#

%ops = ( "and" => 0, "or" => 0 );

sub usage()
{
    my $name = $0;
    $name =~ s@.*/@@g;
    @ops = sort keys %ops;
    die <<EOF;

Usage: $name <op> <config> ...

Valid ops are: @ops
EOF
}

%symbols = ();
%settings = ();
%versions = ();

sub read_config()
{
    my $file = $_[0];

    open(IN, "<$file") or die "Cannot open config file $file,";
    while (defined($line = <IN>)) {
	chomp($line);
	if (($symbol, $val) = $line =~ /(CONFIG_[A-Za-z0-9_]+)(.*)/) {
	    $val =~ s/^=//;
	    $val =~ s/ is not set/n/;
	    $symbols{$symbol} = $symbol;
	    $settings{$file}{$symbol} = $val;
	} elsif (($version) = $line =~/Linux kernel version: (.*)/) {
	    $versions{$file} = $version;
	}
    }
    close(IN);
}

sub symbol_and()
{
    my $a = $_[0];
    my $b = $_[1];

    return 'n' if ($a eq 'n' or $b eq 'n');
    return 'm' if ($a eq 'm' or $b eq 'm');
    return 'y' if ($a eq 'y' or $b eq 'y');
    print "Cannot compare \"$a\" and \"$b\"\n";
    return $a;
}

sub symbol_or()
{
    my $a = $_[0];
    my $b = $_[1];

    return 'y' if ($a eq 'y' or $b eq 'y');
    return 'm' if ($a eq 'm' or $b eq 'm');
    return 'n' if ($a eq 'n' or $b eq 'n');
    print "Cannot compare \"$a\" and \"$b\"\n";
    return $a;
}

&usage if scalar(@ARGV) < 2;

$op = shift @ARGV;
&usage if !defined($ops{$op});

for $file (@ARGV) {
    &read_config($file);
}

$version = $versions{$ARGV[0]};
for $file (@ARGV) {
    if ($versions{$file} ne $version) {
	print "$file: version $versions{$file} != $version\n";
    }
}

for $symbol (sort keys %symbols) {
    if ($op eq 'and') {
	$res = 'y';
	for $file (@ARGV) {
	    if (!defined($settings{$file}{$symbol})) {
		$res = 'n';
	    } else {
		$res = &symbol_and($res, $settings{$file}{$symbol});
	    }
	    last if $res eq 'n';
	}
    } elsif ($op eq 'or') {
	$res = 'n';
	for $file (@ARGV) {
	    next if !defined($settings{$file}{$symbol});
	    $res = &symbol_or($res, $settings{$file}{$symbol});
	    last if $res eq 'y';
	}
    }
    if ($res eq 'n') {
	print "# $symbol is not set\n";
    } elsif ($res eq 'm' or $res eq 'y') {
	print "$symbol=$res\n";
    } else {
	print "$symbol=\"$res\"\n";
    }
}