Add check-configs.pl script from Paul Bolle

We can run this once per RC (or somewhat frequently) to keep the split
config-* files clean of dead Kconfig options

scripts/check-configs.pl

@@ -0,0 +1,83 @@
+# By Paul Bolle October 2014.
+#
+# Contributed to the public domain by its author.
+
+use 5.016;
+use warnings;
+use autodie;
+
+use File::Find;
+
+my @Kconfigs;
+
+my $Kconfigre = qr/Kconfig.*/;
+my $configre = qr/^\s*(menu)?config\s+(?<config>(\w+))$/;
+my $CONFIG_re = qr/\bCONFIG_(?<CONFIG_>(\w+))/;
+
+sub match {
+	push( @Kconfigs, $File::Find::name ) if ($_ =~ $Kconfigre);
+}
+
+sub parse_kconfig {
+	my ($path) = @_;
+
+	my @ret;
+
+	open( my $kconfig, "<", $path );
+	my $slurp = do { local $/ = undef; <$kconfig> };
+	close( $kconfig );
+	my @lines = split ( /\n/, $slurp );
+	foreach my $line (@lines) {
+		if ($line =~ /$configre/) {
+			push( @ret, $+{config} );
+		}
+	}
+
+	@ret;
+}
+
+sub parse_shipped {
+	my ($path) = @_;
+
+	my @ret;
+
+	open( my $shipped, "<", $path );
+	my $slurp = do { local $/ = undef; <$shipped> };
+	close( $shipped );
+	my @lines = split ( /\n/, $slurp );
+	my $i = 1;
+	foreach my $line (@lines) {
+		if ($line =~ /$CONFIG_re/) {
+			push( @ret, [$i, $+{CONFIG_}] );
+		}
+		$i++;
+	}
+
+	@ret;
+}
+
+exit main ( @ARGV );
+
+sub main {
+	my %configs;
+
+	find( \&match, @_ );
+
+	foreach my $Kconfig (@Kconfigs) {
+		my (@tmp) = parse_kconfig( $Kconfig );
+		foreach my $config ( @tmp ) {
+			$configs{ $config }++;
+		}
+	}
+
+	foreach my $shipped (glob("config-*")) {
+		my (@tmp) = parse_shipped( $shipped );
+		foreach my $ref ( @tmp ) {
+			say( STDERR "$shipped:$ref->[0]: No Kconfig symbol matches 'CONFIG_$ref->[1]'" )
+				unless (grep( /$ref->[1]/, keys( %configs )));
+		}
+	}
+
+	0;
+}
+