X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnamespace%2Fclean.pm;h=19f4519ddfc59fc15e332ad01761fe8a58d69d74;hb=a6b490abbada8789fcd7dc51b677c48984e8df17;hp=76bb92ebd3ae9d4a77c284b5db9967c619221d1a;hpb=226432f602f11579ef0d87d70bbe31547bbd66aa;p=p5sagit%2Fnamespace-clean.git diff --git a/lib/namespace/clean.pm b/lib/namespace/clean.pm index 76bb92e..19f4519 100644 --- a/lib/namespace/clean.pm +++ b/lib/namespace/clean.pm @@ -1,28 +1,237 @@ 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) +# -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); +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); + } -=head1 VERSION + my @symbols = map { + my $name = $_ . $f; + my $def = $cleanee_stash->get_symbol($name); + defined($def) ? [$name, $def] : () + } '$', '@', '%', ''; -0.11 + $cleanee_stash->remove_glob($f); -=cut + # 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}; -$VERSION = '0.11'; -$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; + $cleanee_stash->add_symbol(@$_) 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; + } + } + + 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 %{ $store->{remove} }); + }; + + return 1; + } +} + +sub unimport { + my ($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 @@ -62,7 +271,7 @@ $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 +292,33 @@ 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 +=head3 Late binding caveat + +Note that the L 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 style of +the C built-in invocation. The following example will not work, because +C does not try to resolve the function name to an actual code reference +until B. + + use MyApp::Utils 'my_sorter'; + use namespace::clean; + + my @sorted = sort my_sorter @list; -It is also possible to explicitely tell C what packages +You need to work around this by forcing a compile-time resolution like so: + + use MyApp::Utils 'sorter'; + use namespace::clean; + + my $my_sorter_cref = \&sorter; + + my @sorted = sort $my_sorter_cref @list; + +=head2 Explicitly removing functions when your scope is compiled + +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 +372,6 @@ 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. @@ -155,130 +383,11 @@ 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. -=cut - -my $RemoveSubs = sub { - - my $cleanee = shift; - my $store = shift; - SYMBOL: - for my $f (@_) { - my $fq = "${cleanee}::$f"; - - # ignore already removed symbols - next SYMBOL if $store->{exclude}{ $f }; - no strict 'refs'; - - next SYMBOL unless exists ${ "${cleanee}::" }{ $f }; - - if (ref(\${ "${cleanee}::" }{ $f }) eq 'GLOB') { - # convince the Perl debugger to work - # it assumes that sub_fullname($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; - } - - local *__tmp; - - # keep original value to restore non-code slots - { no warnings 'uninitialized'; # fix possible unimports - *__tmp = *{ ${ "${cleanee}::" }{ $f } }; - delete ${ "${cleanee}::" }{ $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 }; - } - } - else { - # A non-glob in the stash is assumed to stand for some kind - # of function. So far they all do, but the core might change - # this some day. Watch perl5-porters. - delete ${ "${cleanee}::" }{ $f }; - } - } -}; - -sub clean_subroutines { - my ($nc, $cleanee, @subs) = @_; - $RemoveSubs->($cleanee, {}, @subs); -} - =head2 import Makes a snapshot of the current defined functions and installs a L 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); - - # 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 $functions->{ $f } - and *{ $functions->{ $f } }{CODE}; - $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} }); - }; - $store->{handler_is_installed} = 1; - } - - return 1; - } -} =head2 unimport @@ -288,68 +397,20 @@ This method will be called when you do a It will start a new section of code that defines functions to clean up. -=cut - -sub unimport { - my ($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}{ $f } = 1; - } - - return 1; -} - =head2 get_class_store -This returns a reference to a hash in a passed package containing +This returns a reference to a hash in a passed package containing information about function names included and excluded from removal. -=cut - -sub get_class_store { - my ($pragma, $class) = @_; - no strict 'refs'; - return \%{ "${class}::${STORAGE_VAR}" }; -} - =head2 get_functions Takes a class as argument and returns all currently defined functions in it as a hash reference with the function name as key and a typeglob reference to the symbol as value. -=cut - -sub get_functions { - my ($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 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}; @@ -368,17 +429,38 @@ use C instead. 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 * -no warnings; -'Danger! Laws of Thermodynamics may not apply.' +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.