perf doc: Fix doc.dep

#!/usr/bin/perl

my %include = ();

my %included = ();

for my $text (<*.txt>) {

    open I, '<', $text || die "cannot read: $text";

    while (<I>) {

	if (/^include::/) {

	    chomp;

	    s/^include::\s*//;

	    s/\[\]//;

	    $include{$text}{$_} = 1;

	    $included{$_} = 1;

	}

    }

    close I;

}

# Do we care about chained includes???

my $changed = 1;

while ($changed) {

    $changed = 0;

    while (my ($text, $included) = each %include) {

	for my $i (keys %$included) {

	    # $text has include::$i; if $i includes $j

	    # $text indirectly includes $j.

	    if (exists $include{$i}) {

		for my $j (keys %{$include{$i}}) {

		    if (!exists $include{$text}{$j}) {

			$include{$text}{$j} = 1;

			$included{$j} = 1;

			$changed = 1;

		    }

		}

	    }

	}

    }

}

while (my ($text, $included) = each %include) {

    if (! exists $included{$text} &&

	(my $base = $text) =~ s/\.txt$//) {

	print "$base.html $base.xml : ", join(" ", keys %$included), "\n";

    }

}