#!/usr/bin/perl -w
# by Hagen Fritsch
# Released under the terms of the GPL
# Generates a depency tree in dot-format based upon c-files.
# Requires gcc to compile the c-sources to asm-files for a simple
# parsing process...
#
# usage: perl $0 *.c | springgraph > graph.png

my %dep = ();
foreach(@ARGV) {
	system("gcc -S '$_'");
	/^(.+)\.c$/i;
	my $curname = 'none';
	open(FILE, "$1.s") || die $!;
	while(<FILE>) {
		if(/^([^\.\s].+?):/) {
			$curname = $1;
			$dep{$curname} = ();
		}
		if(/call\s+(.+)/) {
			$dep{$curname}{$1} = 1 if(!exists $dep{$curname}{$1});
		}
	}
	close(FILE);
}
print <<"EOT";
digraph "source tree" {
    overlap=scale;
    size="8,10";
    ratio="fill";
    fontsize="16";
    fontname="Helvetica";
    clusterrank="local";
EOT

foreach my $d (keys %dep) {
	foreach(keys %{$dep{$d}}) {
		print STDERR "Warning: Symbol $_ unknown.\n" if(!exists $dep{$_});
		print "\t\"$d\" -> \"$_\"\n";
	}
}
print "}\n";