X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnamespace%2Fclean.pm;h=e80413b2ab1f9969d18774bdbc8b7876e7048cc4;hb=18377f5b;hp=ac82f8b08c37ca597c9bacdf71540f3efb769df4;hpb=6c0ece9ba4e73a0f83be4fc6e92072995fd21696;p=p5sagit%2Fnamespace-clean.git diff --git a/lib/namespace/clean.pm b/lib/namespace/clean.pm index ac82f8b..e80413b 100644 --- a/lib/namespace/clean.pm +++ b/lib/namespace/clean.pm @@ -1,26 +1,232 @@ package namespace::clean; -=head1 NAME +use warnings; +use strict; -namespace::clean - Keep imports and functions out of your namespace +our $VERSION = '0.25'; +$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; -use vars qw( $VERSION $STORAGE_VAR ); -use Symbol qw( qualify_to_ref ); -use Filter::EOF; + if ( $] < 5.008007 ) { + require Package::Stash::PP; + $provider = 'Package::Stash::PP'; + } + else { + require Package::Stash; + $provider = 'Package::Stash'; + } + eval <<"EOS" or die $@; -=head1 VERSION +sub stash_for (\$) { + $provider->new(\$_[0]); +} -0.03 +1; -=cut +EOS +} + +use namespace::clean::_Util qw( DEBUGGER_NEEDS_CV_RENAME DEBUGGER_NEEDS_CV_PIVOT ); + +# Built-in debugger CV-retrieval fixups necessary before perl 5.15.5: +# since we are deleting the glob where the subroutine was originally +# defined, the assumptions below no longer hold. +# +# In 5.8.9 ~ 5.13.5 (inclusive) the debugger assumes that a CV can +# always be found under sub_fullname($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 +# +# 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 + && + 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); +} + +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 { + $is_explicit++; + last ARG; + } + } -$VERSION = 0.03; -$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; + 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}{ $f } = 1; + } + + # register EOF handler on first call to import + unless ($store->{handler_is_installed}) { + on_scope_end { + $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} }); + }; + $store->{handler_is_installed} = 1; + } + + return 1; + } +} + +sub unimport { + my ($pragma, %args) = @_; + + # 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 }; + $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 @@ -55,10 +261,12 @@ $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; =head1 DESCRIPTION +=head2 Keeping packages clean + When you define a function, or import one, into a Perl package, it will naturally also be available as a method. This does not per se cause problems, but it can complicate subclassing and, for example, plugin -classes that are included via multiple inheritance by loading them as +classes that are included via multiple inheritance by loading them as base classes. The C pragma will remove all previously declared or @@ -69,91 +277,101 @@ name, but they won't show up as methods on your class or instances. By unimporting via C you can tell C to start collecting functions for the next C specification. -=head1 METHODS +You can use the C<-except> flag to tell C that you +don't want it to remove a certain function or method. A common use would +be a module exporting an C method along with some functions: -You shouldn't need to call any of these. Just C the package at the -appropriate place. + use ModuleExportingImport; + use namespace::clean -except => [qw( import )]; -=cut +If you just want to C<-except> a single sub, you can pass it directly. +For more than one value you have to use an array reference. -=head2 import +=head2 Explicitly removing functions when your scope is compiled -Makes a snapshot of the current defined functions and registers a -L cleanup routine to remove those symbols at the end -of the compile-time. +It is also possible to explicitly tell C what packages +to remove when the surrounding scope has finished compiling. Here is an +example: -=cut + package Foo; + use strict; -sub import { - my ($pragma) = @_; + # blessed NOT available - # calling class, all current functions and our storage - my $cleanee = caller; - my $functions = $pragma->get_functions($cleanee); - my $store = $pragma->get_class_store($cleanee); - - # register symbols for removal, if they have a CODE entry - for my $f (keys %$functions) { - next unless $functions->{ $f } - and *{ $functions->{ $f } }{CODE}; - $store->{remove}{ $f } = 1; - } + sub my_class { + use Scalar::Util qw( blessed ); + use namespace::clean qw( blessed ); - # register EOF handler on first call to import - unless ($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 }; - } - }); - $store->{handler_is_installed} = 1; - } + # blessed available + return blessed shift; + } - return 1; -} + # blessed NOT available -=head2 unimport +=head2 Moose -This method will be called when you do a +When using C together with L you want to keep +the installed C method. So your classes should look like: - no namespace::clean; + package Foo; + use Moose; + use namespace::clean -except => 'meta'; + ... -It will start a new section of code that defines functions to clean up. +Same goes for L. -=cut +=head2 Cleaning other packages -sub unimport { - my ($pragma) = @_; +You can tell C 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: - # 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); + package My::MooseX::namespace::clean; + use strict; - # register all unknown previous functions as excluded - for my $f (keys %$functions) { - next if $store->{remove}{ $f } - or $store->{exclude}{ $f }; - $store->{exclude}{ $f } = 1; - } + use namespace::clean (); # no cleanup, just load - return 1; -} + sub import { + namespace::clean->import( + -cleanee => scalar(caller), + -except => 'meta', + ); + } -=head2 get_class_store +If you don't care about Cs discover-and-C<-except> logic, and +just want to remove subroutines, try L. -This returns a reference to a hash in a passed package containing -information about function names included and excluded from removal. +=head1 METHODS -=cut +=head2 clean_subroutines -sub get_class_store { - my ($pragma, $class) = @_; - no strict 'refs'; - return \%{ "${class}::${STORAGE_VAR}" }; -} +This exposes the actual subroutine-removal logic. + + namespace::clean->clean_subroutines($cleanee, qw( subA subB )); + +will remove C and C from C<$cleanee>. Note that this will remove the +subroutines B and not wait for scope end. If you want to have this +effect at a specific time (e.g. C acts on scope compile end) +it is your responsibility to make sure it runs at that time. + +=head2 import + +Makes a snapshot of the current defined functions and installs a +L hook in the current scope to invoke the cleanups. + + +=head2 unimport + +This method will be called when you do a + + no namespace::clean; + +It will start a new section of code that defines functions to clean up. + +=head2 get_class_store + +This returns a reference to a hash in a passed package containing +information about function names included and excluded from removal. =head2 get_functions @@ -161,29 +379,16 @@ Takes a class as argument and returns all currently defined functions in it as a hash reference with the function name as key and a typeglob reference to the symbol as value. -=cut - -sub get_functions { - my ($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 $SomePackage::{foo}; will remove the C symbol from C<$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. +already resolved names in the package itself. C will +restore and therefor in effect keep all glob slots that aren't C. A test file has been added to the perl core to ensure that this behaviour will be stable in future releases. @@ -193,18 +398,40 @@ use C instead. =head1 SEE ALSO -L +L -=head1 AUTHOR AND COPYRIGHT +=head1 THANKS -Robert 'phaylon' Sedlacek Crs@474.atE>, 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 + +=item * + +Florian Ragwitz + +=item * + +Jesse Luehrs + +=item * + +Peter Rabbitson + +=item * + +Father Chrysostomos + +=back + +=head1 COPYRIGHT AND LICENSE + +This software is copyright (c) 2011 by L + +This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.