#!perl -w
use strict;

package deprecate;
use Config;
use Carp;
use warnings;
our $VERSION = 0.01;

sub import {
    my ($package, $file, $line) = caller;
    my $expect_leaf = "$package.pm";
    $expect_leaf =~ s!::!/!g;

    foreach my $pair ([qw(sitearchexp archlibexp)],
		      [qw(sitelibexp privlibexp)]) {
	my ($site, $priv) = @Config{@$pair};
	# Just in case anyone managed to configure with trailing /s
	s!/*$!!g foreach $site, $priv;

	next if $site eq $priv;
	if ("$priv/$expect_leaf" eq $file) {
	    # This is fragile, because it
	    # 1: depends on the number of call stacks in if.pm
	    # 2: is directly poking in the internals of warnings.pm
	    my ($call_file, $call_line, $callers_bitmask) = (caller 3)[1,2,9];

	    if (defined $callers_bitmask
            	&& (vec($callers_bitmask, $warnings::Offsets{deprecated}, 1)
		    || vec($callers_bitmask, $warnings::Offsets{all}, 1))) {
		warn <<"EOM";
$package will be removed from the Perl core distribution in the next major release. Please install it from CPAN. It is being used at $call_file line $call_line
EOM
	    }
	    return;
	}
    }
}

1;