#!/usr/bin/perl -W

%include = ();

die "Usage: scandeps prefix object_dirs -- sources" if (@ARGV < 4);

$prefix = shift @ARGV;
$prefix = $prefix;  # silence warning

@objdirs = ();
while (($z = shift @ARGV) ne "--") {
	push @objdirs, $z;
}

# scan all files for relevant #include lines
foreach my $file (@ARGV) {
	open FILE, "<$file" or die "Failed to open $file: $!";
	while (my $line = <FILE>) {
		if ($line =~ m|#include "$prefix/?([^"]+)"|) {
			$include{$file}{$1} = 1;
		}
	}
	close FILE;
}

# output dependencies
foreach my $file (@ARGV) {
	next unless $file =~ m|([^/]+)[.]c$|;
	%deps = ();
	search_deps($file);
	foreach my $z (@objdirs) {
		print "$z/$1.o ";
	}
	print ": $file ";
	foreach my $z (sort keys %deps) { print "$z " }
	print "\n";
}


sub search_deps {
	my $file = shift;
	return unless exists $include{$file};
	foreach my $z (keys %{$include{$file}}) {
		next if exists $deps{$z};
		$deps{$z} = 1;
		search_deps($z);
	}
}