Commit | Line | Data |
40aef9d6 |
1 | package namespace::clean; |
04312494 |
2 | # ABSTRACT: Keep imports and functions out of your namespace |
40aef9d6 |
3 | |
4 | use warnings; |
5 | use strict; |
6 | |
8177960a |
7 | use vars qw( $STORAGE_VAR ); |
9887772b |
8 | use Package::Stash; |
40aef9d6 |
9 | |
d87b7435 |
10 | our $VERSION = '0.21_01'; |
fa84e425 |
11 | |
8177960a |
12 | $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; |
40aef9d6 |
13 | |
9887772b |
14 | BEGIN { |
1cd61d2e |
15 | |
7b026c56 |
16 | use warnings; |
17 | use strict; |
18 | |
1cd61d2e |
19 | # when changing also change in Makefile.PL |
20 | my $b_h_eos_req = '0.07'; |
21 | |
9bb3eaa2 |
22 | if (! $ENV{NAMESPACE_CLEAN_USE_PP} and eval { |
9887772b |
23 | require B::Hooks::EndOfScope; |
1cd61d2e |
24 | B::Hooks::EndOfScope->VERSION($b_h_eos_req); |
9887772b |
25 | 1 |
26 | } ) { |
27 | B::Hooks::EndOfScope->import('on_scope_end'); |
28 | } |
29 | else { |
30 | eval <<'PP' or die $@; |
31 | |
1cd61d2e |
32 | use Tie::Hash (); |
33 | |
34 | { |
35 | package namespace::clean::_TieHintHash; |
36 | |
7b026c56 |
37 | use warnings; |
38 | use strict; |
39 | |
1cd61d2e |
40 | use base 'Tie::ExtraHash'; |
41 | } |
42 | |
9887772b |
43 | { |
44 | package namespace::clean::_ScopeGuard; |
45 | |
7b026c56 |
46 | use warnings; |
47 | use strict; |
48 | |
9887772b |
49 | sub arm { bless [ $_[1] ] } |
50 | |
51 | sub DESTROY { $_[0]->[0]->() } |
52 | } |
53 | |
9887772b |
54 | |
55 | sub on_scope_end (&) { |
56 | $^H |= 0x020000; |
57 | |
58 | if( my $stack = tied( %^H ) ) { |
1cd61d2e |
59 | if ( (my $c = ref $stack) ne 'namespace::clean::_TieHintHash') { |
60 | die <<EOE; |
61 | ======================================================================== |
62 | !!! F A T A L E R R O R !!! |
63 | |
64 | foreign tie() of %^H detected |
65 | ======================================================================== |
66 | |
67 | namespace::clean is currently operating in pure-perl fallback mode, because |
68 | your system is lacking the necessary dependency B::Hooks::EndOfScope $b_h_eos_req. |
69 | In this mode namespace::clean expects to be able to tie() the hinthash %^H, |
70 | however it is apparently already tied by means unknown to the tie-class |
71 | $c |
72 | |
73 | Since this is a no-win situation execution will abort here and now. Please |
74 | try to find out which other module is relying on hinthash tie() ability, |
75 | and file a bug for both the perpetrator and namespace::clean, so that the |
76 | authors can figure out an acceptable way of moving forward. |
77 | |
78 | EOE |
79 | } |
9887772b |
80 | push @$stack, namespace::clean::_ScopeGuard->arm(shift); |
81 | } |
82 | else { |
656ec55b |
83 | my %old_contents = %^H; |
84 | %^H = (); |
1cd61d2e |
85 | tie( %^H, 'namespace::clean::_TieHintHash', namespace::clean::_ScopeGuard->arm(shift) ); |
656ec55b |
86 | $^H{$_} = $old_contents{$_} for keys %old_contents; |
9887772b |
87 | } |
88 | } |
89 | |
90 | 1; |
91 | |
92 | PP |
93 | |
94 | } |
95 | } |
96 | |
09e4e594 |
97 | =head1 NAME |
98 | |
99 | namespace::clean - Keep imports and functions out of your namespace |
100 | |
40aef9d6 |
101 | =head1 SYNOPSIS |
102 | |
103 | package Foo; |
104 | use warnings; |
105 | use strict; |
106 | |
6c0ece9b |
107 | use Carp qw(croak); # 'croak' will be removed |
40aef9d6 |
108 | |
6c0ece9b |
109 | sub bar { 23 } # 'bar' will be removed |
40aef9d6 |
110 | |
6c0ece9b |
111 | # remove all previously defined functions |
40aef9d6 |
112 | use namespace::clean; |
113 | |
6c0ece9b |
114 | sub baz { bar() } # 'baz' still defined, 'bar' still bound |
40aef9d6 |
115 | |
6c0ece9b |
116 | # begin to collection function names from here again |
9b680ffe |
117 | no namespace::clean; |
118 | |
6c0ece9b |
119 | sub quux { baz() } # 'quux' will be removed |
9b680ffe |
120 | |
6c0ece9b |
121 | # remove all functions defined after the 'no' unimport |
9b680ffe |
122 | use namespace::clean; |
123 | |
6c0ece9b |
124 | # Will print: 'No', 'No', 'Yes' and 'No' |
40aef9d6 |
125 | print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n"; |
126 | print +(__PACKAGE__->can('bar') ? 'Yes' : 'No'), "\n"; |
127 | print +(__PACKAGE__->can('baz') ? 'Yes' : 'No'), "\n"; |
9b680ffe |
128 | print +(__PACKAGE__->can('quux') ? 'Yes' : 'No'), "\n"; |
40aef9d6 |
129 | |
130 | 1; |
131 | |
132 | =head1 DESCRIPTION |
133 | |
de673bbf |
134 | =head2 Keeping packages clean |
135 | |
40aef9d6 |
136 | When you define a function, or import one, into a Perl package, it will |
137 | naturally also be available as a method. This does not per se cause |
138 | problems, but it can complicate subclassing and, for example, plugin |
04312494 |
139 | classes that are included via multiple inheritance by loading them as |
6c0ece9b |
140 | base classes. |
40aef9d6 |
141 | |
142 | The C<namespace::clean> pragma will remove all previously declared or |
143 | imported symbols at the end of the current package's compile cycle. |
6c0ece9b |
144 | Functions called in the package itself will still be bound by their |
145 | name, but they won't show up as methods on your class or instances. |
146 | |
147 | By unimporting via C<no> you can tell C<namespace::clean> to start |
148 | collecting functions for the next C<use namespace::clean;> specification. |
40aef9d6 |
149 | |
53e92ec5 |
150 | You can use the C<-except> flag to tell C<namespace::clean> that you |
472d4b1e |
151 | don't want it to remove a certain function or method. A common use would |
152 | be a module exporting an C<import> method along with some functions: |
53e92ec5 |
153 | |
154 | use ModuleExportingImport; |
155 | use namespace::clean -except => [qw( import )]; |
156 | |
472d4b1e |
157 | If you just want to C<-except> a single sub, you can pass it directly. |
158 | For more than one value you have to use an array reference. |
159 | |
271df965 |
160 | =head2 Explicitly removing functions when your scope is compiled |
de673bbf |
161 | |
271df965 |
162 | It is also possible to explicitly tell C<namespace::clean> what packages |
de673bbf |
163 | to remove when the surrounding scope has finished compiling. Here is an |
164 | example: |
165 | |
166 | package Foo; |
167 | use strict; |
168 | |
169 | # blessed NOT available |
170 | |
171 | sub my_class { |
172 | use Scalar::Util qw( blessed ); |
173 | use namespace::clean qw( blessed ); |
174 | |
175 | # blessed available |
176 | return blessed shift; |
177 | } |
178 | |
179 | # blessed NOT available |
180 | |
1a1be5dc |
181 | =head2 Moose |
182 | |
183 | When using C<namespace::clean> together with L<Moose> you want to keep |
184 | the installed C<meta> method. So your classes should look like: |
185 | |
186 | package Foo; |
187 | use Moose; |
188 | use namespace::clean -except => 'meta'; |
189 | ... |
190 | |
191 | Same goes for L<Moose::Role>. |
192 | |
fcfe7810 |
193 | =head2 Cleaning other packages |
194 | |
195 | You can tell C<namespace::clean> that you want to clean up another package |
196 | instead of the one importing. To do this you have to pass in the C<-cleanee> |
197 | option like this: |
198 | |
199 | package My::MooseX::namespace::clean; |
200 | use strict; |
201 | |
202 | use namespace::clean (); # no cleanup, just load |
203 | |
204 | sub import { |
205 | namespace::clean->import( |
206 | -cleanee => scalar(caller), |
207 | -except => 'meta', |
208 | ); |
209 | } |
210 | |
211 | If you don't care about C<namespace::clean>s discover-and-C<-except> logic, and |
212 | just want to remove subroutines, try L</clean_subroutines>. |
213 | |
fa84e425 |
214 | =head1 METHODS |
215 | |
216 | =head2 clean_subroutines |
40aef9d6 |
217 | |
fcfe7810 |
218 | This exposes the actual subroutine-removal logic. |
219 | |
220 | namespace::clean->clean_subroutines($cleanee, qw( subA subB )); |
221 | |
222 | will remove C<subA> and C<subB> from C<$cleanee>. Note that this will remove the |
223 | subroutines B<immediately> and not wait for scope end. If you want to have this |
224 | effect at a specific time (e.g. C<namespace::clean> acts on scope compile end) |
225 | it is your responsibility to make sure it runs at that time. |
40aef9d6 |
226 | |
227 | =cut |
228 | |
80e4e267 |
229 | # Constant to optimise away the unused code branches |
230 | use constant RENAME_SUB => $] > 5.008_008_9 && $] < 5.013_006_1; |
231 | { no strict; delete ${__PACKAGE__."::"}{RENAME_SUB} } |
232 | |
233 | # In perl 5.8.9-5.12, it assumes that sub_fullname($sub) can |
234 | # always be used to find the CV again. |
235 | # In perl 5.8.8 and 5.14, it assumes that the name of the glob |
236 | # passed to entersub can be used to find the CV. |
237 | # since we are deleting the glob where the subroutine was originally |
238 | # defined, those assumptions no longer hold. |
239 | # |
240 | # So in 5.8.9-5.12 we need to move it elsewhere and point the |
241 | # CV's name to the new glob. |
242 | # |
243 | # In 5.8.8 and 5.14 we move it elsewhere and rename the |
244 | # original glob by assigning the new glob back to it. |
017bd598 |
245 | my $sub_utils_loaded; |
80e4e267 |
246 | my $DebuggerFixup = sub { |
017bd598 |
247 | my ($f, $sub, $cleanee_stash, $deleted_stash) = @_; |
248 | |
80e4e267 |
249 | if (RENAME_SUB) { |
250 | if (! defined $sub_utils_loaded ) { |
251 | $sub_utils_loaded = do { |
b3279c1c |
252 | |
253 | # when changing version also change in Makefile.PL |
80e4e267 |
254 | my $sn_ver = 0.04; |
255 | eval { require Sub::Name; Sub::Name->VERSION($sn_ver) } |
256 | or die "Sub::Name $sn_ver required when running under -d or equivalent: $@"; |
017bd598 |
257 | |
b3279c1c |
258 | # when changing version also change in Makefile.PL |
80e4e267 |
259 | my $si_ver = 0.04; |
260 | eval { require Sub::Identify; Sub::Identify->VERSION($si_ver) } |
261 | or die "Sub::Identify $si_ver required when running under -d or equivalent: $@"; |
fcfe7810 |
262 | |
80e4e267 |
263 | 1; |
264 | } ? 1 : 0; |
265 | } |
017bd598 |
266 | |
80e4e267 |
267 | if ( Sub::Identify::sub_fullname($sub) eq ($cleanee_stash->name . "::$f") ) { |
268 | my $new_fq = $deleted_stash->name . "::$f"; |
269 | Sub::Name::subname($new_fq, $sub); |
270 | $deleted_stash->add_symbol("&$f", $sub); |
271 | } |
272 | } |
273 | else { |
017bd598 |
274 | $deleted_stash->add_symbol("&$f", $sub); |
275 | } |
276 | }; |
277 | |
278 | my $RemoveSubs = sub { |
de673bbf |
279 | my $cleanee = shift; |
280 | my $store = shift; |
16d8eca5 |
281 | my $cleanee_stash = Package::Stash->new($cleanee); |
017bd598 |
282 | my $deleted_stash; |
283 | |
de673bbf |
284 | SYMBOL: |
285 | for my $f (@_) { |
017bd598 |
286 | |
de673bbf |
287 | # ignore already removed symbols |
288 | next SYMBOL if $store->{exclude}{ $f }; |
de673bbf |
289 | |
017bd598 |
290 | my $sub = $cleanee_stash->get_symbol("&$f") |
291 | or next SYMBOL; |
226432f6 |
292 | |
80e4e267 |
293 | my $need_debugger_fixup = |
294 | $^P |
295 | && |
296 | ref(my $globref = \$cleanee_stash->namespace->{$f}) eq 'GLOB' |
297 | ; |
298 | |
299 | if ($need_debugger_fixup) { |
300 | # convince the Perl debugger to work |
301 | # see the comment on top of $DebuggerFixup |
302 | $DebuggerFixup->( |
303 | $f, |
304 | $sub, |
305 | $cleanee_stash, |
306 | $deleted_stash ||= Package::Stash->new("namespace::clean::deleted::$cleanee"), |
307 | ); |
de673bbf |
308 | } |
d6aecfbf |
309 | |
d64ad6f8 |
310 | my @symbols = map { |
311 | my $name = $_ . $f; |
312 | my $def = $cleanee_stash->get_symbol($name); |
313 | defined($def) ? [$name, $def] : () |
ad4b1a60 |
314 | } '$', '@', '%', ''; |
d64ad6f8 |
315 | |
c86d6ae2 |
316 | $cleanee_stash->remove_glob($f); |
d64ad6f8 |
317 | |
80e4e267 |
318 | # if this perl needs no renaming trick we need to |
319 | # rename the original glob after the fact |
320 | # (see commend of $DebuggerFixup |
321 | if (!RENAME_SUB && $need_debugger_fixup) { |
322 | *$globref = $deleted_stash->namespace->{$f}; |
323 | } |
324 | |
d64ad6f8 |
325 | $cleanee_stash->add_symbol(@$_) for @symbols; |
de673bbf |
326 | } |
327 | }; |
53e92ec5 |
328 | |
fcfe7810 |
329 | sub clean_subroutines { |
330 | my ($nc, $cleanee, @subs) = @_; |
331 | $RemoveSubs->($cleanee, {}, @subs); |
332 | } |
333 | |
fa84e425 |
334 | =head2 import |
fcfe7810 |
335 | |
336 | Makes a snapshot of the current defined functions and installs a |
337 | L<B::Hooks::EndOfScope> hook in the current scope to invoke the cleanups. |
338 | |
339 | =cut |
340 | |
de673bbf |
341 | sub import { |
342 | my ($pragma, @args) = @_; |
53e92ec5 |
343 | |
de673bbf |
344 | my (%args, $is_explicit); |
fcfe7810 |
345 | |
346 | ARG: |
347 | while (@args) { |
348 | |
349 | if ($args[0] =~ /^\-/) { |
350 | my $key = shift @args; |
351 | my $value = shift @args; |
352 | $args{ $key } = $value; |
353 | } |
354 | else { |
355 | $is_explicit++; |
356 | last ARG; |
357 | } |
9b680ffe |
358 | } |
359 | |
fcfe7810 |
360 | my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; |
de673bbf |
361 | if ($is_explicit) { |
aa2aafae |
362 | on_scope_end { |
de673bbf |
363 | $RemoveSubs->($cleanee, {}, @args); |
aa2aafae |
364 | }; |
9b680ffe |
365 | } |
de673bbf |
366 | else { |
367 | |
368 | # calling class, all current functions and our storage |
369 | my $functions = $pragma->get_functions($cleanee); |
370 | my $store = $pragma->get_class_store($cleanee); |
16d8eca5 |
371 | my $stash = Package::Stash->new($cleanee); |
de673bbf |
372 | |
373 | # except parameter can be array ref or single value |
374 | my %except = map {( $_ => 1 )} ( |
375 | $args{ -except } |
376 | ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } ) |
377 | : () |
378 | ); |
379 | |
380 | # register symbols for removal, if they have a CODE entry |
381 | for my $f (keys %$functions) { |
382 | next if $except{ $f }; |
c86d6ae2 |
383 | next unless $stash->has_symbol("&$f"); |
de673bbf |
384 | $store->{remove}{ $f } = 1; |
385 | } |
386 | |
387 | # register EOF handler on first call to import |
388 | unless ($store->{handler_is_installed}) { |
aa2aafae |
389 | on_scope_end { |
de673bbf |
390 | $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} }); |
aa2aafae |
391 | }; |
de673bbf |
392 | $store->{handler_is_installed} = 1; |
393 | } |
394 | |
395 | return 1; |
396 | } |
9b680ffe |
397 | } |
398 | |
fa84e425 |
399 | =head2 unimport |
9b680ffe |
400 | |
401 | This method will be called when you do a |
402 | |
403 | no namespace::clean; |
404 | |
405 | It will start a new section of code that defines functions to clean up. |
406 | |
407 | =cut |
408 | |
409 | sub unimport { |
fcfe7810 |
410 | my ($pragma, %args) = @_; |
9b680ffe |
411 | |
6c0ece9b |
412 | # the calling class, the current functions and our storage |
fcfe7810 |
413 | my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; |
9b680ffe |
414 | my $functions = $pragma->get_functions($cleanee); |
415 | my $store = $pragma->get_class_store($cleanee); |
416 | |
6c0ece9b |
417 | # register all unknown previous functions as excluded |
9b680ffe |
418 | for my $f (keys %$functions) { |
419 | next if $store->{remove}{ $f } |
420 | or $store->{exclude}{ $f }; |
421 | $store->{exclude}{ $f } = 1; |
422 | } |
423 | |
424 | return 1; |
425 | } |
426 | |
fa84e425 |
427 | =head2 get_class_store |
9b680ffe |
428 | |
04312494 |
429 | This returns a reference to a hash in a passed package containing |
6c0ece9b |
430 | information about function names included and excluded from removal. |
9b680ffe |
431 | |
432 | =cut |
433 | |
434 | sub get_class_store { |
435 | my ($pragma, $class) = @_; |
16d8eca5 |
436 | my $stash = Package::Stash->new($class); |
5460fcfb |
437 | my $var = "%$STORAGE_VAR"; |
c86d6ae2 |
438 | $stash->add_symbol($var, {}) |
439 | unless $stash->has_symbol($var); |
440 | return $stash->get_symbol($var); |
40aef9d6 |
441 | } |
442 | |
fa84e425 |
443 | =head2 get_functions |
40aef9d6 |
444 | |
445 | Takes a class as argument and returns all currently defined functions |
446 | in it as a hash reference with the function name as key and a typeglob |
447 | reference to the symbol as value. |
448 | |
449 | =cut |
450 | |
451 | sub get_functions { |
452 | my ($pragma, $class) = @_; |
453 | |
16d8eca5 |
454 | my $stash = Package::Stash->new($class); |
40aef9d6 |
455 | return { |
c86d6ae2 |
456 | map { $_ => $stash->get_symbol("&$_") } |
457 | $stash->list_all_symbols('CODE') |
40aef9d6 |
458 | }; |
459 | } |
460 | |
6c0ece9b |
461 | =head1 IMPLEMENTATION DETAILS |
462 | |
04312494 |
463 | This module works through the effect that a |
6c0ece9b |
464 | |
465 | delete $SomePackage::{foo}; |
466 | |
467 | will remove the C<foo> symbol from C<$SomePackage> for run time lookups |
468 | (e.g., method calls) but will leave the entry alive to be called by |
472d4b1e |
469 | already resolved names in the package itself. C<namespace::clean> will |
470 | restore and therefor in effect keep all glob slots that aren't C<CODE>. |
6c0ece9b |
471 | |
472 | A test file has been added to the perl core to ensure that this behaviour |
473 | will be stable in future releases. |
474 | |
475 | Just for completeness sake, if you want to remove the symbol completely, |
476 | use C<undef> instead. |
477 | |
9887772b |
478 | =head1 CAVEATS |
479 | |
480 | This module is fully functional in a pure-perl environment, where |
c8e3fb7e |
481 | L<B::Hooks::EndOfScope> (with the XS dependency L<Variable::Magic>), may |
482 | not be available. However in this case this module falls back to a |
9887772b |
483 | L<tie()|perlfunc/tie> of L<%^H|perlvar/%^H> which may or may not interfere |
484 | with some crack you may be doing independently of namespace::clean. |
485 | |
c8e3fb7e |
486 | If you want to ensure that your codebase is protected from this unlikely |
487 | clash, you need to explicitly depend on L<B::Hooks::EndOfScope>. |
488 | |
40aef9d6 |
489 | =head1 SEE ALSO |
490 | |
705fe1b1 |
491 | L<B::Hooks::EndOfScope> |
40aef9d6 |
492 | |
04312494 |
493 | =head1 THANKS |
40aef9d6 |
494 | |
04312494 |
495 | Many thanks to Matt S Trout for the inspiration on the whole idea. |
40aef9d6 |
496 | |
fa84e425 |
497 | =head1 AUTHORS |
498 | |
499 | =over |
500 | |
501 | =item * |
502 | |
503 | Robert 'phaylon' Sedlacek <rs@474.at> |
504 | |
505 | =item * |
506 | |
507 | Florian Ragwitz <rafl@debian.org> |
508 | |
509 | =item * |
510 | |
511 | Jesse Luehrs <doy@tozt.net> |
512 | |
513 | =item * |
514 | |
515 | Peter Rabbitson <ribasushi@cpan.org> |
516 | |
517 | =back |
518 | |
519 | =head1 COPYRIGHT AND LICENSE |
520 | |
521 | This software is copyright (c) 2011 by Robert 'phaylon' Sedlacek. |
522 | |
523 | This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. |
524 | |
40aef9d6 |
525 | =cut |
526 | |
de673bbf |
527 | no warnings; |
528 | 'Danger! Laws of Thermodynamics may not apply.' |