PC World Komputer 2010 April/PCWorld0410.iso/hity wydania/Ubuntu 9.10 PL/karmelkowy-koliberek-desktop-9.10-i386-PL.iso/casper/filesystem.squashfs/usr/src/linux-headers-2.6.31-14/scripts/headerdep.pl

Perl Script | 2009-09-09 | 4KB | 194 lines

#! /usr/bin/perl
#
# Detect cycles in the header file dependency graph
# Vegard Nossum <[e-mail]>
#

use strict;
use warnings;

use Getopt::Long;

my $opt_all;
my @opt_include;
my $opt_graph;

&Getopt::Long::Configure(qw(bundling pass_through));
&GetOptions(
    help    => \&help,
    version    => \&version,

    all    => \$opt_all,
    "I=s"    => \@opt_include,
    graph    => \$opt_graph,
);

push @opt_include, 'include';
my %deps = ();
my %linenos = ();

my @headers = grep { strip($_) } @ARGV;

parse_all(@headers);

if($opt_graph) {
    graph();
} else {
    detect_cycles(@headers);
}


sub help {
    print "Usage: $0 [options] file...\n";
    print "\n";
    print "Options:\n";
    print "  --all\n";
    print "  --graph\n";
    print "\n";
    print "  -I includedir\n";
    print "\n";
    print "To make nice graphs, try:\n";
    print "  $0 --graph include/linux/kernel.h | dot -Tpng -o graph.png\n";
    exit;
}

sub version {
    print "headerdep version 2\n";
    exit;
}

# Get a file name that is relative to our include paths
sub strip {
    my $filename = shift;

    for my $i (@opt_include) {
        my $stripped = $filename;
        $stripped =~ s/^$i\///;

        return $stripped if $stripped ne $filename;
    }

    return $filename;
}

# Search for the file name in the list of include paths
sub search {
    my $filename = shift;
    return $filename if -f $filename;

    for my $i (@opt_include) {
        my $path = "$i/$filename";
        return $path if -f $path;
    }

    return undef;
}

sub parse_all {
    # Parse all the headers.
    my @queue = @_;
    while(@queue) {
        my $header = pop @queue;
        next if exists $deps{$header};

        $deps{$header} = [] unless exists $deps{$header};

        my $path = search($header);
        next unless $path;

        open(my $file, '<', $path) or die($!);
        chomp(my @lines = <$file>);
        close($file);

        for my $i (0 .. $#lines) {
            my $line = $lines[$i];
            if(my($dep) = ($line =~ m/^#\s*include\s*<(.*?)>/)) {
                push @queue, $dep;
                push @{$deps{$header}}, [$i + 1, $dep];
            }
        }
    }
}

sub print_cycle {
    # $cycle[n] includes $cycle[n + 1];
    # $cycle[-1] will be the culprit
    my $cycle = shift;

    # Adjust the line numbers
    for my $i (0 .. $#$cycle - 1) {
        $cycle->[$i]->[0] = $cycle->[$i + 1]->[0];
    }
    $cycle->[-1]->[0] = 0;

    my $first = shift @$cycle;
    my $last = pop @$cycle;

    my $msg = "In file included";
    printf "%s from %s,\n", $msg, $last->[1] if defined $last;

    for my $header (reverse @$cycle) {
        printf "%s from %s:%d%s\n",
            " " x length $msg,
            $header->[1], $header->[0],
            $header->[1] eq $last->[1] ? ' <-- here' : '';
    }

    printf "%s:%d: warning: recursive header inclusion\n",
        $first->[1], $first->[0];
}

# Find and print the smallest cycle starting in the specified node.
sub detect_cycles {
    my @queue = map { [[0, $_]] } @_;
    while(@queue) {
        my $top = pop @queue;
        my $name = $top->[-1]->[1];

        for my $dep (@{$deps{$name}}) {
            my $chain = [@$top, [$dep->[0], $dep->[1]]];

            # If the dep already exists in the chain, we have a
            # cycle...
            if(grep { $_->[1] eq $dep->[1] } @$top) {
                print_cycle($chain);
                next if $opt_all;
                return;
            }

            push @queue, $chain;
        }
    }
}

sub mangle {
    $_ = shift;
    s/\//__/g;
    s/\./_/g;
    s/-/_/g;
    $_;
}

# Output dependency graph in GraphViz language.
sub graph {
    print "digraph {\n";

    print "\t/* vertices */\n";
    for my $header (keys %deps) {
        printf "\t%s [label=\"%s\"];\n",
            mangle($header), $header;
    }

    print "\n";

    print "\t/* edges */\n";
    for my $header (keys %deps) {
        for my $dep (@{$deps{$header}}) {
            printf "\t%s -> %s;\n",
                mangle($header), mangle($dep->[1]);
        }
    }

    print "}\n";
}