X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnamespace%2Fclean.pm;h=1e6d51af071b7d54d8109ef8aced866a1df00ea6;hb=656ec55b51c454ca3d8a06a728a4f6c06d6db5d5;hp=a23e6e97bb7020f27588bb2e99cda9a0508df7e1;hpb=07fbef3daa75ec3d7339aa3d0daf16dfd46a5a84;p=p5sagit%2Fnamespace-clean.git diff --git a/lib/namespace/clean.pm b/lib/namespace/clean.pm index a23e6e9..1e6d51a 100644 --- a/lib/namespace/clean.pm +++ b/lib/namespace/clean.pm @@ -1,28 +1,102 @@ package namespace::clean; +# ABSTRACT: Keep imports and functions out of your namespace -=head1 NAME +use warnings; +use strict; -namespace::clean - Keep imports and functions out of your namespace +use vars qw( $STORAGE_VAR ); +use Package::Stash; -=cut +our $VERSION = '0.21'; -use warnings; -use strict; +$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; -use vars qw( $VERSION $STORAGE_VAR $SCOPE_HOOK_KEY $SCOPE_EXPLICIT ); -use Symbol qw( qualify_to_ref gensym ); -use B::Hooks::EndOfScope; -use Sub::Identify qw(sub_fullname); -use Sub::Name qw(subname); +BEGIN { -=head1 VERSION + use warnings; + use strict; -0.11 + # when changing also change in Makefile.PL + my $b_h_eos_req = '0.07'; -=cut + 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'); + } + else { + eval <<'PP' or die $@; + + use Tie::Hash (); + + { + package namespace::clean::_TieHintHash; + + use warnings; + use strict; + + use base 'Tie::ExtraHash'; + } + + { + package namespace::clean::_ScopeGuard; + + use warnings; + use strict; + + sub arm { bless [ $_[1] ] } -$VERSION = '0.11'; -$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; + sub DESTROY { $_[0]->[0]->() } + } + + + sub on_scope_end (&) { + $^H |= 0x020000; + + if( my $stack = tied( %^H ) ) { + if ( (my $c = ref $stack) ne 'namespace::clean::_TieHintHash') { + die <arm(shift); + } + else { + my %old_contents = %^H; + %^H = (); + tie( %^H, 'namespace::clean::_TieHintHash', namespace::clean::_ScopeGuard->arm(shift) ); + $^H{$_} = $old_contents{$_} for keys %old_contents; + } + } + + 1; + +PP + + } +} + +=head1 NAME + +namespace::clean - Keep imports and functions out of your namespace =head1 SYNOPSIS @@ -62,7 +136,7 @@ $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; 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 pragma will remove all previously declared or @@ -83,9 +157,9 @@ be a module exporting an C method along with some functions: 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 Explicitely removing functions when your scope is compiled +=head2 Explicitly removing functions when your scope is compiled -It is also possible to explicitely tell C what packages +It is also possible to explicitly tell C what packages to remove when the surrounding scope has finished compiling. Here is an example: @@ -139,11 +213,6 @@ just want to remove subroutines, try L. =head1 METHODS -You shouldn't need to call any of these. Just C the package at the -appropriate place. - -=cut - =head2 clean_subroutines This exposes the actual subroutine-removal logic. @@ -157,46 +226,103 @@ it is your responsibility to make sure it runs at that time. =cut -my $RemoveSubs = sub { +# Constant to optimise away the unused code branches +use constant RENAME_SUB => $] > 5.008_008_9 && $] < 5.013_006_1; +{ no strict; delete ${__PACKAGE__."::"}{RENAME_SUB} } + +# In perl 5.8.9-5.12, it assumes that sub_fullname($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 (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: $@"; + + 1; + } ? 1 : 0; + } + if ( Sub::Identify::sub_fullname($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 (@_) { - my $fq = "${cleanee}::$f"; # ignore already removed symbols next SYMBOL if $store->{exclude}{ $f }; - no strict 'refs'; - - # convince the Perl debugger to work - # it assumes that sub_fullname($sub) can always be used to find the CV again - # since we are deleting the glob where the subroutine was originally - # defined, that assumption no longer holds, so we need to move it - # elsewhere and point the CV's name to the new glob. - my $sub = \&$fq; - if ( sub_fullname($sub) eq $fq ) { - my $new_fq = "namespace::clean::deleted::$fq"; - subname($new_fq, $sub); - *{$new_fq} = $sub; + + my $sub = $cleanee_stash->get_symbol("&$f") + or next SYMBOL; + + my $need_debugger_fixup = + $^P + && + ref(my $globref = \$cleanee_stash->namespace->{$f}) eq 'GLOB' + ; + + if ($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"), + ); } - local *__tmp; + my @symbols = map { + my $name = $_ . $f; + my $def = $cleanee_stash->get_symbol($name); + defined($def) ? [$name, $def] : () + } '$', '@', '%', ''; - # keep original value to restore non-code slots - { no warnings 'uninitialized'; # fix possible unimports - *__tmp = *{ ${ "${cleanee}::" }{ $f } }; - delete ${ "${cleanee}::" }{ $f }; - } + $cleanee_stash->remove_glob($f); - SLOT: - # restore non-code slots to symbol. - # omit the FORMAT slot, since perl erroneously puts it into the - # SCALAR slot of the new glob. - for my $t (qw( SCALAR ARRAY HASH IO )) { - next SLOT unless defined *__tmp{ $t }; - *{ "${cleanee}::$f" } = *__tmp{ $t }; + # if this perl needs no renaming trick we need to + # rename the original glob after the fact + # (see commend of $DebuggerFixup + if (!RENAME_SUB && $need_debugger_fixup) { + *$globref = $deleted_stash->namespace->{$f}; } + + $cleanee_stash->add_symbol(@$_) for @symbols; } }; @@ -242,6 +368,7 @@ sub import { # 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 )} ( @@ -253,8 +380,7 @@ sub import { # 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}; + next unless $stash->has_symbol("&$f"); $store->{remove}{ $f } = 1; } @@ -300,15 +426,18 @@ sub unimport { =head2 get_class_store -This returns a reference to a hash in a passed package containing +This returns a reference to a hash in a passed package containing information about function names included and excluded from removal. =cut sub get_class_store { my ($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 @@ -322,24 +451,16 @@ reference to the symbol as value. sub get_functions { my ($pragma, $class) = @_; + my $stash = Package::Stash->new($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 + map { $_ => $stash->get_symbol("&$_") } + $stash->list_all_symbols('CODE') }; } -=head1 BUGS - -C will clobber any formats that have the same name as -a deleted sub. This is due to a bug in perl that makes it impossible to -re-assign the FORMAT ref into a new glob. - =head1 IMPLEMENTATION DETAILS -This module works through the effect that a +This module works through the effect that a delete $SomePackage::{foo}; @@ -354,19 +475,52 @@ will be stable in future releases. Just for completeness sake, if you want to remove the symbol completely, use C instead. +=head1 CAVEATS + +This module is fully functional in a pure-perl environment, where +L (with the XS dependency L), may +not be available. However in this case this module falls back to a +L of L<%^H|perlvar/%^H> which may or may not interfere +with some crack you may be doing independently of namespace::clean. + +If you want to ensure that your codebase is protected from this unlikely +clash, you need to explicitly depend on L. + =head1 SEE ALSO L -=head1 AUTHOR AND COPYRIGHT +=head1 THANKS + +Many thanks to Matt S Trout for the inspiration on the whole idea. + +=head1 AUTHORS + +=over + +=item * + +Robert 'phaylon' Sedlacek + +=item * + +Florian Ragwitz + +=item * + +Jesse Luehrs + +=item * + +Peter Rabbitson + +=back -Robert 'phaylon' Sedlacek Crs@474.atE>, 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 Robert 'phaylon' Sedlacek. -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