package namespace::clean;
-=head1 NAME
+use warnings;
+use strict;
-namespace::clean - Keep imports and functions out of your namespace
+our $VERSION = '0.26';
+$VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases
-=cut
+our $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
-use warnings;
-use strict;
+use B::Hooks::EndOfScope 'on_scope_end';
+
+# FIXME This is a crock of shit, needs to go away
+# currently here to work around https://rt.cpan.org/Ticket/Display.html?id=74151
+# kill with fire when PS::XS is *finally* fixed
+BEGIN {
+ my $provider;
+
+ if ( "$]" < 5.008007 ) {
+ require Package::Stash::PP;
+ $provider = 'Package::Stash::PP';
+ }
+ else {
+ require Package::Stash;
+ $provider = 'Package::Stash';
+ }
+ eval <<"EOS" or die $@;
+
+sub stash_for (\$) {
+ $provider->new(\$_[0]);
+}
+
+1;
+
+EOS
+}
+
+use namespace::clean::_Util qw( DEBUGGER_NEEDS_CV_RENAME DEBUGGER_NEEDS_CV_PIVOT );
+
+# Built-in debugger CV-retrieval fixups necessary before perl 5.15.5:
+# since we are deleting the glob where the subroutine was originally
+# defined, the assumptions below no longer hold.
+#
+# In 5.8.9 ~ 5.13.5 (inclusive) the debugger assumes that a CV can
+# always be found under sub_fullname($sub)
+# Workaround: use sub naming to properly name the sub hidden in the package's
+# deleted-stash
+#
+# In the rest of the range ( ... ~ 5.8.8 and 5.13.6 ~ 5.15.4 ) the debugger
+# assumes the name of the glob passed to entersub can be used to find the CV
+# Workaround: realias the original glob to the deleted-stash slot
+#
+# While the errors manifest themselves inside perl5db.pl, they are caused by
+# problems inside the interpreter. If enabled ($^P & 0x01) and existent,
+# the DB::sub sub will be called by the interpreter for any sub call rather
+# that call the sub directly. It is provided the real sub to call in $DB::sub,
+# but the value given has the issues described above. We only have to enable
+# the workaround if DB::sub will be used.
+#
+# Can not tie constants to the current value of $^P directly,
+# as the debugger can be enabled during runtime (kinda dubious)
+#
+
+my $RemoveSubs = sub {
+ my $cleanee = shift;
+ my $store = shift;
+ my $cleanee_stash = stash_for($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 =
+ ( DEBUGGER_NEEDS_CV_RENAME or DEBUGGER_NEEDS_CV_PIVOT )
+ &&
+ $^P & 0x01
+ &&
+ defined &DB::sub
+ &&
+ ref(my $globref = \$cleanee_stash->namespace->{$f}) eq 'GLOB'
+ &&
+ ( $deleted_stash ||= stash_for("namespace::clean::deleted::$cleanee") )
+ ;
+
+ # convince the Perl debugger to work
+ # see the comment on top
+ if ( DEBUGGER_NEEDS_CV_RENAME and $need_debugger_fixup ) {
+ #
+ # Note - both get_subname and set_subname are only compiled when CV_RENAME
+ # is true ( the 5.8.9 ~ 5.12 range ). On other perls this entire block is
+ # constant folded away, and so are the definitions in ::_Util
+ #
+ # Do not be surprised that they are missing without DEBUGGER_NEEDS_CV_RENAME
+ #
+ namespace::clean::_Util::get_subname( $sub ) eq ( $cleanee_stash->name . "::$f" )
+ and
+ $deleted_stash->add_symbol(
+ "&$f",
+ namespace::clean::_Util::set_subname( $deleted_stash->name . "::$f", $sub ),
+ );
+ }
+ elsif ( DEBUGGER_NEEDS_CV_PIVOT and $need_debugger_fixup ) {
+ $deleted_stash->add_symbol("&$f", $sub);
+ }
+
+ 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
+ DEBUGGER_NEEDS_CV_PIVOT
+ and
+ $need_debugger_fixup
+ and
+ *$globref = $deleted_stash->namespace->{$f};
+
+ $cleanee_stash->add_symbol(@$_) for @symbols;
+ }
+};
+
+sub clean_subroutines {
+ my ($nc, $cleanee, @subs) = @_;
+ $RemoveSubs->($cleanee, {}, @subs);
+}
-use vars qw( $VERSION $STORAGE_VAR );
-use Symbol qw( qualify_to_ref );
-use Filter::EOF;
+sub import {
+ my ($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;
+ }
+ }
-=head1 VERSION
+ 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 $stash = stash_for($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;
+ }
+
+ on_scope_end {
+ $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} });
+ };
+
+ return 1;
+ }
+}
-0.06
+sub unimport {
+ my ($pragma, %args) = @_;
-=cut
+ # 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);
-$VERSION = 0.06;
-$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
+ # register all unknown previous functions as excluded
+ for my $f (keys %$functions) {
+ next if $store->{remove}{ $f }
+ or $store->{exclude}{ $f };
+ $store->{exclude}{ $f } = 1;
+ }
+
+ return 1;
+}
+
+sub get_class_store {
+ my ($pragma, $class) = @_;
+ my $stash = stash_for($class);
+ my $var = "%$STORAGE_VAR";
+ $stash->add_symbol($var, {})
+ unless $stash->has_symbol($var);
+ return $stash->get_symbol($var);
+}
+
+sub get_functions {
+ my ($pragma, $class) = @_;
+
+ my $stash = stash_for($class);
+ return {
+ map { $_ => $stash->get_symbol("&$_") }
+ $stash->list_all_symbols('CODE')
+ };
+}
+
+'Danger! Laws of Thermodynamics may not apply.'
+
+__END__
+
+=head1 NAME
+
+namespace::clean - Keep imports and functions out of your namespace
=head1 SYNOPSIS
=head1 DESCRIPTION
+=head2 Keeping packages clean
+
When you define a function, or import one, into a Perl package, it will
naturally also be available as a method. This does not per se cause
problems, but it can complicate subclassing and, for example, plugin
-classes that are included via multiple inheritance by loading them as
+classes that are included via multiple inheritance by loading them as
base classes.
The C<namespace::clean> pragma will remove all previously declared or
If you just want to C<-except> a single sub, you can pass it directly.
For more than one value you have to use an array reference.
-=head1 METHODS
+=head3 Late binding caveat
-You shouldn't need to call any of these. Just C<use> the package at the
-appropriate place.
+Note that the L<technique used by this module|/IMPLEMENTATION DETAILS> relies
+on perl having resolved all names to actual code references during the
+compilation of a scope. While this is almost always what the interpreter does,
+there are some exceptions, notably the L<sort SUBNAME|perlfunc/sort> style of
+the C<sort> built-in invocation. The following example will not work, because
+C<sort> does not try to resolve the function name to an actual code reference
+until B<runtime>.
-=cut
+ use MyApp::Utils 'my_sorter';
+ use namespace::clean;
-=head2 import
+ my @sorted = sort my_sorter @list;
-Makes a snapshot of the current defined functions and registers a
-L<Filter::EOF> cleanup routine to remove those symbols at the end
-of the compile-time.
+You need to work around this by forcing a compile-time resolution like so:
-=cut
+ use MyApp::Utils 'sorter';
+ use namespace::clean;
-sub import {
- my ($pragma, %args) = @_;
+ my $my_sorter_cref = \&sorter;
- # calling class, all current functions and our storage
- my $cleanee = caller;
- my $functions = $pragma->get_functions($cleanee);
- my $store = $pragma->get_class_store($cleanee);
+ my @sorted = sort $my_sorter_cref @list;
- # except parameter can be array ref or single value
- my %except = map {( $_ => 1 )} (
- $args{ -except }
- ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } )
- : ()
- );
+=head2 Explicitly removing functions when your scope is compiled
- # register symbols for removal, if they have a CODE entry
- for my $f (keys %$functions) {
- next if $except{ $f };
- next unless $functions->{ $f }
- and *{ $functions->{ $f } }{CODE};
- $store->{remove}{ $f } = 1;
- }
+It is also possible to explicitly tell C<namespace::clean> what packages
+to remove when the surrounding scope has finished compiling. Here is an
+example:
- # register EOF handler on first call to import
- unless ($store->{handler_is_installed}) {
- Filter::EOF->on_eof_call(sub {
- SYMBOL:
- for my $f (keys %{ $store->{remove} }) {
-
- # ignore already removed symbols
- next SYMBOL if $store->{exclude}{ $f };
- no strict 'refs';
-
- # keep original value to restore non-code slots
- { no warnings 'uninitialized'; # fix possible unimports
- local *__tmp = *{ ${ "${cleanee}::" }{ $f } };
- delete ${ "${cleanee}::" }{ $f };
- }
-
- SLOT:
- # restore non-code slots to symbol
- for my $t (qw( SCALAR ARRAY HASH IO FORMAT )) {
- next SLOT unless defined *__tmp{ $t };
- *{ "${cleanee}::$f" } = *__tmp{ $t };
- }
- }
- });
- $store->{handler_is_installed} = 1;
- }
+ package Foo;
+ use strict;
- return 1;
-}
+ # blessed NOT available
-=head2 unimport
+ sub my_class {
+ use Scalar::Util qw( blessed );
+ use namespace::clean qw( blessed );
-This method will be called when you do a
+ # blessed available
+ return blessed shift;
+ }
- no namespace::clean;
+ # blessed NOT available
-It will start a new section of code that defines functions to clean up.
+=head2 Moose
-=cut
+When using C<namespace::clean> together with L<Moose> you want to keep
+the installed C<meta> method. So your classes should look like:
-sub unimport {
- my ($pragma) = @_;
+ package Foo;
+ use Moose;
+ use namespace::clean -except => 'meta';
+ ...
- # the calling class, the current functions and our storage
- my $cleanee = caller;
- my $functions = $pragma->get_functions($cleanee);
- my $store = $pragma->get_class_store($cleanee);
+Same goes for L<Moose::Role>.
- # register all unknown previous functions as excluded
- for my $f (keys %$functions) {
- next if $store->{remove}{ $f }
- or $store->{exclude}{ $f };
- $store->{exclude}{ $f } = 1;
- }
+=head2 Cleaning other packages
- return 1;
-}
+You can tell C<namespace::clean> that you want to clean up another package
+instead of the one importing. To do this you have to pass in the C<-cleanee>
+option like this:
-=head2 get_class_store
+ package My::MooseX::namespace::clean;
+ use strict;
-This returns a reference to a hash in a passed package containing
-information about function names included and excluded from removal.
+ use namespace::clean (); # no cleanup, just load
-=cut
+ sub import {
+ namespace::clean->import(
+ -cleanee => scalar(caller),
+ -except => 'meta',
+ );
+ }
+
+If you don't care about C<namespace::clean>s discover-and-C<-except> logic, and
+just want to remove subroutines, try L</clean_subroutines>.
+
+=head1 METHODS
+
+=head2 clean_subroutines
+
+This exposes the actual subroutine-removal logic.
+
+ namespace::clean->clean_subroutines($cleanee, qw( subA subB ));
+
+will remove C<subA> and C<subB> from C<$cleanee>. Note that this will remove the
+subroutines B<immediately> and not wait for scope end. If you want to have this
+effect at a specific time (e.g. C<namespace::clean> acts on scope compile end)
+it is your responsibility to make sure it runs at that time.
+
+=head2 import
+
+Makes a snapshot of the current defined functions and installs a
+L<B::Hooks::EndOfScope> hook in the current scope to invoke the cleanups.
-sub get_class_store {
- my ($pragma, $class) = @_;
- no strict 'refs';
- return \%{ "${class}::${STORAGE_VAR}" };
-}
+
+=head2 unimport
+
+This method will be called when you do a
+
+ no namespace::clean;
+
+It will start a new section of code that defines functions to clean up.
+
+=head2 get_class_store
+
+This returns a reference to a hash in a passed package containing
+information about function names included and excluded from removal.
=head2 get_functions
in it as a hash reference with the function name as key and a typeglob
reference to the symbol as value.
-=cut
-
-sub get_functions {
- my ($pragma, $class) = @_;
-
- return {
- map { @$_ } # key => value
- grep { *{ $_->[1] }{CODE} } # only functions
- map { [$_, qualify_to_ref( $_, $class )] } # get globref
- grep { $_ !~ /::$/ } # no packages
- do { no strict 'refs'; keys %{ "${class}::" } } # symbol entries
- };
-}
-
=head1 IMPLEMENTATION DETAILS
-This module works through the effect that a
+This module works through the effect that a
delete $SomePackage::{foo};
=head1 SEE ALSO
-L<Filter::EOF>
+L<B::Hooks::EndOfScope>
-=head1 AUTHOR AND COPYRIGHT
+=head1 THANKS
-Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
-Matt S Trout for the inspiration on the whole idea.
+Many thanks to Matt S Trout for the inspiration on the whole idea.
-=head1 LICENSE
+=head1 AUTHORS
-This program is free software; you can redistribute it and/or modify
-it under the same terms as perl itself.
+=over
-=cut
+=item *
-1;
+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>
+
+=back
+
+=head1 COPYRIGHT AND LICENSE
+
+This software is copyright (c) 2011 by L</AUTHORS>
+
+This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
projects / p5sagit/namespace-clean.git / blobdiff