#! /usr/local/bin/perl 

# List the symbols "imported" (ie undefined) in a .o or .a file.
# Typically used in conjunction with summarise:
#
#  imports liboskit_kern.a  | summarise str lmm osenv_ oskit_ 
#
# You might also want to uncomment the lines that filter tedious entries
# out of the output.

$nm = "nm";

foreach $f (@ARGV) {
    ($IN,$OUT) = &typeof($f);
    $IN = &diff($IN,$OUT);

# Filter that strips internal symbols out
#
#     $IN  = &zap($IN, "^FDEV_LINUX_");
#     $OUT = &zap($OUT,"^FDEV_LINUX_");
# 
#     $IN  = &zap($IN, "^OSKIT_LINUX_");
#     $OUT = &zap($OUT,"^OSKIT_LINUX_");
# 
#     $IN  = &zap($IN, "_iid\$");

    print "\t",join("\n\t",sort(keys %$IN)), "\n";
}

exit 0;

sub typeof {
    local ($filename) = @_;	
    local (%IMPORTS,%EXPORTS);
    local ($x);
    open(FILE, "$nm -pa $filename |") || die "Can't find $filename\n";
    while (<FILE>) {
	@fields = split;

	if ($fields[0] =~ /[U]/) { 
	    $IMPORTS{$fields[1]} = 1;
	}
	if ($fields[1] =~ /[ABCDGIRSTW]/) { 
	    $EXPORTS{$fields[2]} = 1;
	}
    }
    return \(%IMPORTS,%EXPORTS);
#   close <FILE>;
}

sub diff {
    local ($X,$Y) = @_;
    local ($x,%r);
    foreach $x (keys %$X) {
	$r{$x} = 1 unless exists $$Y{$x};
    }
    return \%r;
}

sub zap {
    local ($X,$patt) = @_;
    local ($x,%r);
    foreach $x (keys %$X) {
	$r{$x} = 1 unless $x =~ /$patt/;
    }
    return \%r;
}