#!/usr/bin/perl

use Modern::Perl;
require File::Temp;


my $cob = qr{^cob=/(?:usr/)?lib};
my $ob = qr{^ob=/(?:usr/)?lib/};
my $calls = qr{^calls=};

open (my $fh, '<', $ARGV[0]) or die $!;
my $tmp = File::Temp->new(UNLINK => 1);

###
## Skip all external libraries, as defined by $ob
while (readline $fh) {
    if (/$ob/ ) {
        # skip the entire ob= section we don't need.
        0 while defined($_ = readline $fh) && !/^ob=/;

        # put the last line back, we read too far
        seek($fh, -length($_), 1);
    } else {
        print $tmp $_;
    }
}
close ($fh);

###
## Skip all calls to external libraries, as defined by $cob
my $tmpname = $tmp->filename;
open ($tmp, '<', $tmpname) or die $!;
while (readline $tmp) {
    if (/$cob/) {

        # skip until we find a line starting with calls=
        # skip that line too
        0 while defined($_ = readline $tmp) && !/$calls/;

        # then we skip until we either hit ^word= or an empty line.
        # In other words: skip all lines that start with 0x
        0 while defined($_ = readline $tmp) && /^0x/;

        # put the last line back, we read too far
        seek($tmp, -length($_), 1);

    }  else {
       print;
    }
}