#!/usr/bin/perl -w
use warnings;
use strict;
my ($tag, %list);
while (<DATA>){
  next unless /./;
  if (/^(\w+)/){
    $tag = $1;
    next;
  }
  if (/^-- (\w+)/){
    push @{$list{$tag}}, $1;
  }
}

print "get_call_chains\n";
print "---------------\n";
for my $call_chain ( get_call_chains("main") ){
    print join(" ", @$call_chain),"\n";
}
print "\n\n";
print "print_call_chains\n";
print "-----------------\n";
print_call_chains("main");

sub get_call_chains {
    my $root = shift;

    my @calls;
    if( exists $list{$root} ){
        for (@{$list{$root}}){
            push @calls,  get_call_chains($_);
        }
    }
    else {
        @calls = ([]);
    }

    unshift @$_, $root for @calls;

    return @calls
}

sub print_call_chains {
    my @stack = @_;

    my $current = $stack[$#stack];
    if(exists $list{$current})
    {
        for (@{$list{$current}}){
            print_call_chains(@stack, $_);
        }
    }
    else {
        print join(" ", @stack),"\n";
    }
}
__END__

main
-- check
-- check1

check
-- computing
-- net

check1
-- computing2
-- net2

computing
-- community