xref: /openbsd-src/gnu/usr.bin/perl/lib/deprecate.pm (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1package deprecate;
2use strict;
3use warnings;
4our $VERSION = 0.02;
5
6# our %Config can ignore %Config::Config, e.g. for testing
7our %Config;
8unless (%Config) { require Config; *Config = \%Config::Config; }
9
10# This isn't a public API. It's internal to code maintained by the perl-porters
11# If you would like it to be a public API, please send a patch with
12# documentation and tests. Until then, it may change without warning.
13sub __loaded_from_core {
14    my ($package, $file, $expect_leaf) = @_;
15
16    foreach my $pair ([qw(sitearchexp archlibexp)],
17		      [qw(sitelibexp privlibexp)]) {
18	my ($site, $priv) = @Config{@$pair};
19	if ($^O eq 'VMS') {
20	    for my $d ($site, $priv) { $d = VMS::Filespec::unixify($d) };
21	}
22	# Just in case anyone managed to configure with trailing /s
23	s!/*$!!g foreach $site, $priv;
24
25	next if $site eq $priv;
26	if (uc("$priv/$expect_leaf") eq uc($file)) {
27	    return 1;
28	}
29    }
30    return 0;
31}
32
33sub import {
34    my ($package, $file) = caller;
35
36    my $expect_leaf = "$package.pm";
37    $expect_leaf =~ s!::!/!g;
38
39    if (__loaded_from_core($package, $file, $expect_leaf)) {
40	my $call_depth=1;
41	my @caller;
42	while (@caller = caller $call_depth++) {
43	    last if $caller[7]			# use/require
44		and $caller[6] eq $expect_leaf;	# the package file
45	}
46	unless (@caller) {
47	    require Carp;
48	    Carp::cluck(<<"EOM");
49Can't find use/require $expect_leaf in caller stack
50EOM
51	    return;
52	}
53
54	# This is fragile, because it
55	# is directly poking in the internals of warnings.pm
56	my ($call_file, $call_line, $callers_bitmask) = @caller[1,2,9];
57
58	if (defined $callers_bitmask
59	    && (vec($callers_bitmask, $warnings::Offsets{deprecated}, 1)
60		|| vec($callers_bitmask, $warnings::Offsets{all}, 1))) {
61	    warn <<"EOM";
62$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.
63EOM
64	}
65    }
66}
67
681;
69
70__END__
71
72=head1 NAME
73
74deprecate - Perl pragma for deprecating the core version of a module
75
76=head1 SYNOPSIS
77
78    use deprecate;	# always deprecate the module in which this occurs
79
80    use if $] > 5.010, 'deprecate';	# conditionally deprecate the module
81
82
83=head1 DESCRIPTION
84
85This module is used using C<use deprecate;> (or something that calls
86C<< deprecate->import() >>, for example C<use if COND, deprecate;>).
87
88If the module that includes C<use deprecate> is located in a core library
89directory, a deprecation warning is issued, encouraging the user to use
90the version on CPAN.  If that module is located in a site library, it is
91the CPAN version, and no warning is issued.
92
93=head2 EXPORT
94
95None by default.  The only method is C<import>, called by C<use deprecate;>.
96
97
98=head1 SEE ALSO
99
100First example to C<use deprecate;> was L<Switch>.
101
102
103=head1 AUTHOR
104
105Original version by Nicholas Clark
106
107
108=head1 COPYRIGHT AND LICENSE
109
110Copyright (C) 2009, 2011
111
112This library is free software; you can redistribute it and/or modify
113it under the same terms as Perl itself, either Perl version 5.10.0 or,
114at your option, any later version of Perl 5 you may have available.
115
116
117=cut
118