package namespace::clean;
-=head1 NAME
-
-namespace::clean - Keep imports out of your namespace
-
-=cut
-
use warnings;
use strict;
-use vars qw( $VERSION $STORAGE_VAR );
-use Symbol qw( qualify_to_ref );
-use Filter::EOF;
+use vars qw( $STORAGE_VAR );
+use Package::Stash;
-=head1 VERSION
+our $VERSION = '0.21_01';
-0.02
+$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
-=cut
+# FIXME - all of this buggery will migrate to B::H::EOS soon
+BEGIN {
+ # when changing also change in Makefile.PL
+ my $b_h_eos_req = '0.07';
+
+ if (! $ENV{NAMESPACE_CLEAN_USE_PP} and eval {
+ require B::Hooks::EndOfScope;
+ B::Hooks::EndOfScope->VERSION($b_h_eos_req);
+ 1
+ } ) {
+ B::Hooks::EndOfScope->import('on_scope_end');
+ }
+ elsif ($] < 5.009_003_9) {
+ require namespace::clean::_PP_OSE_5_8;
+ *on_scope_end = \&namespace::clean::_PP_OSE_5_8::on_scope_end;
+ }
+ else {
+ require namespace::clean::_PP_OSE;
+ *on_scope_end = \&namespace::clean::_PP_OSE::on_scope_end;
+ }
+}
-$VERSION = 0.02;
-$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
+=head1 NAME
+
+namespace::clean - Keep imports and functions out of your namespace
=head1 SYNOPSIS
use warnings;
use strict;
- use Carp qw(croak); # will be removed
+ use Carp qw(croak); # 'croak' will be removed
- sub bar { 23 } # will be removed
+ sub bar { 23 } # 'bar' will be removed
+ # remove all previously defined functions
use namespace::clean;
- sub baz { bar() } # still defined, 'bar' still bound
+ sub baz { bar() } # 'baz' still defined, 'bar' still bound
+ # begin to collection function names from here again
no namespace::clean;
- sub quux { baz() } # will be removed again
+ sub quux { baz() } # 'quux' will be removed
+ # remove all functions defined after the 'no' unimport
use namespace::clean;
- ### Will print:
- # No
- # No
- # Yes
- # No
+ # Will print: 'No', 'No', 'Yes' and 'No'
print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n";
print +(__PACKAGE__->can('bar') ? 'Yes' : 'No'), "\n";
print +(__PACKAGE__->can('baz') ? 'Yes' : 'No'), "\n";
=head1 DESCRIPTION
+=head2 Keeping packages clean
+
When you define a function, or import one, into a Perl package, it will
naturally also be available as a method. This does not per se cause
problems, but it can complicate subclassing and, for example, plugin
-classes that are included by loading them as base classes.
+classes that are included via multiple inheritance by loading them as
+base classes.
The C<namespace::clean> pragma will remove all previously declared or
imported symbols at the end of the current package's compile cycle.
-This means that functions are already bound by their name, and calls to
-them still work. But they will not be available as methods on your class
-or instances.
+Functions called in the package itself will still be bound by their
+name, but they won't show up as methods on your class or instances.
+
+By unimporting via C<no> you can tell C<namespace::clean> to start
+collecting functions for the next C<use namespace::clean;> specification.
+
+You can use the C<-except> flag to tell C<namespace::clean> that you
+don't want it to remove a certain function or method. A common use would
+be a module exporting an C<import> method along with some functions:
+
+ use ModuleExportingImport;
+ use namespace::clean -except => [qw( import )];
+
+If you just want to C<-except> a single sub, you can pass it directly.
+For more than one value you have to use an array reference.
+
+=head2 Explicitly removing functions when your scope is compiled
+
+It is also possible to explicitly tell C<namespace::clean> what packages
+to remove when the surrounding scope has finished compiling. Here is an
+example:
+
+ package Foo;
+ use strict;
+
+ # blessed NOT available
+
+ sub my_class {
+ use Scalar::Util qw( blessed );
+ use namespace::clean qw( blessed );
+
+ # blessed available
+ return blessed shift;
+ }
+
+ # blessed NOT available
+
+=head2 Moose
+
+When using C<namespace::clean> together with L<Moose> you want to keep
+the installed C<meta> method. So your classes should look like:
+
+ package Foo;
+ use Moose;
+ use namespace::clean -except => 'meta';
+ ...
+
+Same goes for L<Moose::Role>.
+
+=head2 Cleaning other packages
+
+You can tell C<namespace::clean> that you want to clean up another package
+instead of the one importing. To do this you have to pass in the C<-cleanee>
+option like this:
+
+ package My::MooseX::namespace::clean;
+ use strict;
+
+ use namespace::clean (); # no cleanup, just load
+
+ sub import {
+ namespace::clean->import(
+ -cleanee => scalar(caller),
+ -except => 'meta',
+ );
+ }
+
+If you don't care about C<namespace::clean>s discover-and-C<-except> logic, and
+just want to remove subroutines, try L</clean_subroutines>.
=head1 METHODS
-You shouldn't need to call any of these. Just C<use> the package at the
-appropriate place.
+=head2 clean_subroutines
-=head2 import
+This exposes the actual subroutine-removal logic.
+
+ namespace::clean->clean_subroutines($cleanee, qw( subA subB ));
-Makes a snapshot of the current defined functions and registers a
-L<Filter::EOF> cleanup routine to remove those symbols from the package
-at the end of the compile-time.
+will remove C<subA> and C<subB> from C<$cleanee>. Note that this will remove the
+subroutines B<immediately> and not wait for scope end. If you want to have this
+effect at a specific time (e.g. C<namespace::clean> acts on scope compile end)
+it is your responsibility to make sure it runs at that time.
=cut
-sub import {
- my ($pragma) = @_;
+# Constant to optimise away the unused code branches
+use constant FIXUP_NEEDED => $] < 5.015_005_1;
+use constant FIXUP_RENAME_SUB => $] > 5.008_008_9 && $] < 5.013_006_1;
+{
+ no strict;
+ delete ${__PACKAGE__."::"}{FIXUP_NEEDED};
+ delete ${__PACKAGE__."::"}{FIXUP_RENAME_SUB};
+}
- my $cleanee = caller;
- my $functions = $pragma->get_functions($cleanee);
- my $store = $pragma->get_class_store($cleanee);
-
- for my $f (keys %$functions) {
- next unless $functions->{ $f }
- and *{ $functions->{ $f } }{CODE};
- $store->{remove}{ $f } = 1;
+# Debugger fixup necessary before perl 5.15.5
+#
+# In perl 5.8.9-5.12, it assumes that sub_fullname($sub) can
+# always be used to find the CV again.
+# In perl 5.8.8 and 5.14, it assumes that the name of the glob
+# passed to entersub can be used to find the CV.
+# since we are deleting the glob where the subroutine was originally
+# defined, those assumptions no longer hold.
+#
+# So in 5.8.9-5.12 we need to move it elsewhere and point the
+# CV's name to the new glob.
+#
+# In 5.8.8 and 5.14 we move it elsewhere and rename the
+# original glob by assigning the new glob back to it.
+my $sub_utils_loaded;
+my $DebuggerFixup = sub {
+ my ($f, $sub, $cleanee_stash, $deleted_stash) = @_;
+
+ if (FIXUP_RENAME_SUB) {
+ if (! defined $sub_utils_loaded ) {
+ $sub_utils_loaded = do {
+
+ # when changing version also change in Makefile.PL
+ my $sn_ver = 0.04;
+ eval { require Sub::Name; Sub::Name->VERSION($sn_ver) }
+ or die "Sub::Name $sn_ver required when running under -d or equivalent: $@";
+
+ # when changing version also change in Makefile.PL
+ my $si_ver = 0.04;
+ eval { require Sub::Identify; Sub::Identify->VERSION($si_ver) }
+ or die "Sub::Identify $si_ver required when running under -d or equivalent: $@";
+
+ 1;
+ } ? 1 : 0;
}
- unless ($store->{handler_is_installed}) {
- Filter::EOF->on_eof_call(sub {
- for my $f (keys %{ $store->{remove} }) {
- next if $store->{exclude}{ $f };
- no strict 'refs';
- delete ${ "${cleanee}::" }{ $f };
- }
- });
- $store->{handler_is_installed} = 1;
+ if ( Sub::Identify::sub_fullname($sub) eq ($cleanee_stash->name . "::$f") ) {
+ my $new_fq = $deleted_stash->name . "::$f";
+ Sub::Name::subname($new_fq, $sub);
+ $deleted_stash->add_symbol("&$f", $sub);
}
+ }
+ else {
+ $deleted_stash->add_symbol("&$f", $sub);
+ }
+};
+
+my $RemoveSubs = sub {
+ my $cleanee = shift;
+ my $store = shift;
+ my $cleanee_stash = Package::Stash->new($cleanee);
+ my $deleted_stash;
+
+ SYMBOL:
+ for my $f (@_) {
+
+ # ignore already removed symbols
+ next SYMBOL if $store->{exclude}{ $f };
+
+ my $sub = $cleanee_stash->get_symbol("&$f")
+ or next SYMBOL;
+
+ my $need_debugger_fixup =
+ FIXUP_NEEDED
+ &&
+ $^P
+ &&
+ ref(my $globref = \$cleanee_stash->namespace->{$f}) eq 'GLOB'
+ ;
+
+ if (FIXUP_NEEDED && $need_debugger_fixup) {
+ # convince the Perl debugger to work
+ # see the comment on top of $DebuggerFixup
+ $DebuggerFixup->(
+ $f,
+ $sub,
+ $cleanee_stash,
+ $deleted_stash ||= Package::Stash->new("namespace::clean::deleted::$cleanee"),
+ );
+ }
+
+ my @symbols = map {
+ my $name = $_ . $f;
+ my $def = $cleanee_stash->get_symbol($name);
+ defined($def) ? [$name, $def] : ()
+ } '$', '@', '%', '';
+
+ $cleanee_stash->remove_glob($f);
+
+ # if this perl needs no renaming trick we need to
+ # rename the original glob after the fact
+ # (see commend of $DebuggerFixup
+ if (FIXUP_NEEDED && !FIXUP_RENAME_SUB && $need_debugger_fixup) {
+ *$globref = $deleted_stash->namespace->{$f};
+ }
+
+ $cleanee_stash->add_symbol(@$_) for @symbols;
+ }
+};
- return 1;
+sub clean_subroutines {
+ my ($nc, $cleanee, @subs) = @_;
+ $RemoveSubs->($cleanee, {}, @subs);
+}
+
+=head2 import
+
+Makes a snapshot of the current defined functions and installs a
+L<B::Hooks::EndOfScope> hook in the current scope to invoke the cleanups.
+
+=cut
+
+sub import {
+ my ($pragma, @args) = @_;
+
+ my (%args, $is_explicit);
+
+ ARG:
+ while (@args) {
+
+ if ($args[0] =~ /^\-/) {
+ my $key = shift @args;
+ my $value = shift @args;
+ $args{ $key } = $value;
+ }
+ else {
+ $is_explicit++;
+ last ARG;
+ }
+ }
+
+ my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller;
+ if ($is_explicit) {
+ on_scope_end {
+ $RemoveSubs->($cleanee, {}, @args);
+ };
+ }
+ else {
+
+ # calling class, all current functions and our storage
+ my $functions = $pragma->get_functions($cleanee);
+ my $store = $pragma->get_class_store($cleanee);
+ my $stash = Package::Stash->new($cleanee);
+
+ # except parameter can be array ref or single value
+ my %except = map {( $_ => 1 )} (
+ $args{ -except }
+ ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } )
+ : ()
+ );
+
+ # register symbols for removal, if they have a CODE entry
+ for my $f (keys %$functions) {
+ next if $except{ $f };
+ next unless $stash->has_symbol("&$f");
+ $store->{remove}{ $f } = 1;
+ }
+
+ # register EOF handler on first call to import
+ unless ($store->{handler_is_installed}) {
+ on_scope_end {
+ $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} });
+ };
+ $store->{handler_is_installed} = 1;
+ }
+
+ return 1;
+ }
}
=head2 unimport
=cut
sub unimport {
- my ($pragma) = @_;
+ my ($pragma, %args) = @_;
- my $cleanee = caller;
+ # the calling class, the current functions and our storage
+ my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller;
my $functions = $pragma->get_functions($cleanee);
my $store = $pragma->get_class_store($cleanee);
+ # register all unknown previous functions as excluded
for my $f (keys %$functions) {
next if $store->{remove}{ $f }
or $store->{exclude}{ $f };
=head2 get_class_store
-This returns a reference to a hash in your package containing information
-about function names included and excluded from removal.
+This returns a reference to a hash in a passed package containing
+information about function names included and excluded from removal.
=cut
sub get_class_store {
my ($pragma, $class) = @_;
- no strict 'refs';
- return \%{ "${class}::${STORAGE_VAR}" };
+ my $stash = Package::Stash->new($class);
+ my $var = "%$STORAGE_VAR";
+ $stash->add_symbol($var, {})
+ unless $stash->has_symbol($var);
+ return $stash->get_symbol($var);
}
=head2 get_functions
sub get_functions {
my ($pragma, $class) = @_;
+ my $stash = Package::Stash->new($class);
return {
- map { @$_ }
- grep { *{ $_->[1] }{CODE} }
- map { [$_, qualify_to_ref( $_, $class )] }
- grep { $_ !~ /::$/ }
- do { no strict 'refs'; keys %{ "${class}::" } }
+ map { $_ => $stash->get_symbol("&$_") }
+ $stash->list_all_symbols('CODE')
};
}
+=head1 IMPLEMENTATION DETAILS
+
+This module works through the effect that a
+
+ delete $SomePackage::{foo};
+
+will remove the C<foo> symbol from C<$SomePackage> for run time lookups
+(e.g., method calls) but will leave the entry alive to be called by
+already resolved names in the package itself. C<namespace::clean> will
+restore and therefor in effect keep all glob slots that aren't C<CODE>.
+
+A test file has been added to the perl core to ensure that this behaviour
+will be stable in future releases.
+
+Just for completeness sake, if you want to remove the symbol completely,
+use C<undef> instead.
+
=head1 SEE ALSO
-L<Filter::EOF>
+L<B::Hooks::EndOfScope>
+
+=head1 THANKS
+
+Many thanks to Matt S Trout for the inspiration on the whole idea.
+
+=head1 AUTHORS
+
+=over
+
+=item *
+
+Robert 'phaylon' Sedlacek <rs@474.at>
+
+=item *
+
+Florian Ragwitz <rafl@debian.org>
+
+=item *
+
+Jesse Luehrs <doy@tozt.net>
+
+=item *
+
+Peter Rabbitson <ribasushi@cpan.org>
+
+=item *
+
+Father Chrysostomos <sprout@cpan.org>
-=head1 AUTHOR AND COPYRIGHT
+=back
-Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
-Matt S Trout for the inspiration on the whole idea.
+=head1 COPYRIGHT AND LICENSE
-=head1 LICENSE
+This software is copyright (c) 2011 by L</AUTHORS>
-This program is free software; you can redistribute it and/or modify
-it under the same terms as perl itself.
+This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
=cut
-1;
+no warnings;
+'Danger! Laws of Thermodynamics may not apply.'
projects / p5sagit/namespace-clean.git / blobdiff