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1 | package namespace::clean; |
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2 | |
3 | use warnings; |
4 | use strict; |
5 | |
62a21612 |
6 | our $VERSION = '0.25'; |
727a1a2f |
7 | our $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; |
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8 | |
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9 | use B::Hooks::EndOfScope 'on_scope_end'; |
9887772b |
10 | |
acb1d694 |
11 | # FIXME This is a crock of shit, needs to go away |
12 | # currently here to work around https://rt.cpan.org/Ticket/Display.html?id=74151 |
13 | # kill with fire when PS::XS is *finally* fixed |
14 | BEGIN { |
15 | my $provider; |
16 | |
17 | if ( $] < 5.008007 ) { |
18 | require Package::Stash::PP; |
19 | $provider = 'Package::Stash::PP'; |
20 | } |
21 | else { |
22 | require Package::Stash; |
23 | $provider = 'Package::Stash'; |
24 | } |
25 | eval <<"EOS" or die $@; |
26 | |
27 | sub stash_for (\$) { |
28 | $provider->new(\$_[0]); |
29 | } |
30 | |
31 | 1; |
32 | |
33 | EOS |
34 | } |
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35 | |
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36 | use namespace::clean::_Util qw( DEBUGGER_NEEDS_CV_RENAME DEBUGGER_NEEDS_CV_PIVOT ); |
80e4e267 |
37 | |
64c1bcfc |
38 | # Debugger fixup necessary before perl 5.15.5 |
39 | # |
80e4e267 |
40 | # In perl 5.8.9-5.12, it assumes that sub_fullname($sub) can |
41 | # always be used to find the CV again. |
42 | # In perl 5.8.8 and 5.14, it assumes that the name of the glob |
43 | # passed to entersub can be used to find the CV. |
44 | # since we are deleting the glob where the subroutine was originally |
45 | # defined, those assumptions no longer hold. |
46 | # |
47 | # So in 5.8.9-5.12 we need to move it elsewhere and point the |
48 | # CV's name to the new glob. |
49 | # |
50 | # In 5.8.8 and 5.14 we move it elsewhere and rename the |
51 | # original glob by assigning the new glob back to it. |
017bd598 |
52 | my $sub_utils_loaded; |
80e4e267 |
53 | my $DebuggerFixup = sub { |
017bd598 |
54 | my ($f, $sub, $cleanee_stash, $deleted_stash) = @_; |
55 | |
df4cbc4e |
56 | if (DEBUGGER_NEEDS_CV_RENAME) { |
57 | # |
58 | # Note - both get_subname and set_subname are only compiled when CV_RENAME |
59 | # is true ( the 5.8.9 ~ 5.12 range ). On other perls this entire block is |
60 | # constant folded away, and so are the definitions in ::_Util |
61 | # |
62 | # Do not be surprised that they are missing without DEBUGGER_NEEDS_CV_RENAME |
63 | # |
64 | namespace::clean::_Util::get_subname( $sub ) eq ( $cleanee_stash->name . "::$f" ) |
65 | and |
66 | $deleted_stash->add_symbol( |
67 | "&$f", |
68 | namespace::clean::_Util::set_subname( $deleted_stash->name . "::$f", $sub ), |
69 | ); |
80e4e267 |
70 | } |
71 | else { |
017bd598 |
72 | $deleted_stash->add_symbol("&$f", $sub); |
73 | } |
74 | }; |
75 | |
76 | my $RemoveSubs = sub { |
de673bbf |
77 | my $cleanee = shift; |
78 | my $store = shift; |
acb1d694 |
79 | my $cleanee_stash = stash_for($cleanee); |
017bd598 |
80 | my $deleted_stash; |
81 | |
de673bbf |
82 | SYMBOL: |
83 | for my $f (@_) { |
017bd598 |
84 | |
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85 | # ignore already removed symbols |
86 | next SYMBOL if $store->{exclude}{ $f }; |
de673bbf |
87 | |
017bd598 |
88 | my $sub = $cleanee_stash->get_symbol("&$f") |
89 | or next SYMBOL; |
226432f6 |
90 | |
80e4e267 |
91 | my $need_debugger_fixup = |
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92 | ( DEBUGGER_NEEDS_CV_RENAME or DEBUGGER_NEEDS_CV_PIVOT ) |
64c1bcfc |
93 | && |
80e4e267 |
94 | $^P |
95 | && |
96 | ref(my $globref = \$cleanee_stash->namespace->{$f}) eq 'GLOB' |
97 | ; |
98 | |
df4cbc4e |
99 | if ($need_debugger_fixup) { |
80e4e267 |
100 | # convince the Perl debugger to work |
101 | # see the comment on top of $DebuggerFixup |
102 | $DebuggerFixup->( |
103 | $f, |
104 | $sub, |
105 | $cleanee_stash, |
acb1d694 |
106 | $deleted_stash ||= stash_for("namespace::clean::deleted::$cleanee"), |
80e4e267 |
107 | ); |
de673bbf |
108 | } |
d6aecfbf |
109 | |
d64ad6f8 |
110 | my @symbols = map { |
111 | my $name = $_ . $f; |
112 | my $def = $cleanee_stash->get_symbol($name); |
113 | defined($def) ? [$name, $def] : () |
ad4b1a60 |
114 | } '$', '@', '%', ''; |
d64ad6f8 |
115 | |
c86d6ae2 |
116 | $cleanee_stash->remove_glob($f); |
d64ad6f8 |
117 | |
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118 | # if this perl needs no renaming trick we need to |
119 | # rename the original glob after the fact |
120 | # (see commend of $DebuggerFixup |
df4cbc4e |
121 | if (DEBUGGER_NEEDS_CV_PIVOT && $need_debugger_fixup) { |
80e4e267 |
122 | *$globref = $deleted_stash->namespace->{$f}; |
123 | } |
124 | |
d64ad6f8 |
125 | $cleanee_stash->add_symbol(@$_) for @symbols; |
de673bbf |
126 | } |
127 | }; |
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128 | |
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129 | sub clean_subroutines { |
130 | my ($nc, $cleanee, @subs) = @_; |
131 | $RemoveSubs->($cleanee, {}, @subs); |
132 | } |
133 | |
de673bbf |
134 | sub import { |
135 | my ($pragma, @args) = @_; |
53e92ec5 |
136 | |
de673bbf |
137 | my (%args, $is_explicit); |
fcfe7810 |
138 | |
139 | ARG: |
140 | while (@args) { |
141 | |
142 | if ($args[0] =~ /^\-/) { |
143 | my $key = shift @args; |
144 | my $value = shift @args; |
145 | $args{ $key } = $value; |
146 | } |
147 | else { |
148 | $is_explicit++; |
149 | last ARG; |
150 | } |
9b680ffe |
151 | } |
152 | |
fcfe7810 |
153 | my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; |
de673bbf |
154 | if ($is_explicit) { |
aa2aafae |
155 | on_scope_end { |
de673bbf |
156 | $RemoveSubs->($cleanee, {}, @args); |
aa2aafae |
157 | }; |
9b680ffe |
158 | } |
de673bbf |
159 | else { |
160 | |
161 | # calling class, all current functions and our storage |
162 | my $functions = $pragma->get_functions($cleanee); |
163 | my $store = $pragma->get_class_store($cleanee); |
acb1d694 |
164 | my $stash = stash_for($cleanee); |
de673bbf |
165 | |
166 | # except parameter can be array ref or single value |
167 | my %except = map {( $_ => 1 )} ( |
168 | $args{ -except } |
169 | ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } ) |
170 | : () |
171 | ); |
172 | |
173 | # register symbols for removal, if they have a CODE entry |
174 | for my $f (keys %$functions) { |
175 | next if $except{ $f }; |
c86d6ae2 |
176 | next unless $stash->has_symbol("&$f"); |
de673bbf |
177 | $store->{remove}{ $f } = 1; |
178 | } |
179 | |
180 | # register EOF handler on first call to import |
181 | unless ($store->{handler_is_installed}) { |
aa2aafae |
182 | on_scope_end { |
de673bbf |
183 | $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} }); |
aa2aafae |
184 | }; |
de673bbf |
185 | $store->{handler_is_installed} = 1; |
186 | } |
187 | |
188 | return 1; |
189 | } |
9b680ffe |
190 | } |
191 | |
9b680ffe |
192 | sub unimport { |
fcfe7810 |
193 | my ($pragma, %args) = @_; |
9b680ffe |
194 | |
6c0ece9b |
195 | # the calling class, the current functions and our storage |
fcfe7810 |
196 | my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; |
9b680ffe |
197 | my $functions = $pragma->get_functions($cleanee); |
198 | my $store = $pragma->get_class_store($cleanee); |
199 | |
6c0ece9b |
200 | # register all unknown previous functions as excluded |
9b680ffe |
201 | for my $f (keys %$functions) { |
202 | next if $store->{remove}{ $f } |
203 | or $store->{exclude}{ $f }; |
204 | $store->{exclude}{ $f } = 1; |
205 | } |
206 | |
207 | return 1; |
208 | } |
209 | |
9b680ffe |
210 | sub get_class_store { |
211 | my ($pragma, $class) = @_; |
acb1d694 |
212 | my $stash = stash_for($class); |
5460fcfb |
213 | my $var = "%$STORAGE_VAR"; |
c86d6ae2 |
214 | $stash->add_symbol($var, {}) |
215 | unless $stash->has_symbol($var); |
216 | return $stash->get_symbol($var); |
40aef9d6 |
217 | } |
218 | |
40aef9d6 |
219 | sub get_functions { |
220 | my ($pragma, $class) = @_; |
221 | |
acb1d694 |
222 | my $stash = stash_for($class); |
40aef9d6 |
223 | return { |
c86d6ae2 |
224 | map { $_ => $stash->get_symbol("&$_") } |
225 | $stash->list_all_symbols('CODE') |
40aef9d6 |
226 | }; |
227 | } |
228 | |
b3b7a821 |
229 | 'Danger! Laws of Thermodynamics may not apply.' |
230 | |
231 | __END__ |
232 | |
233 | =head1 NAME |
234 | |
235 | namespace::clean - Keep imports and functions out of your namespace |
236 | |
237 | =head1 SYNOPSIS |
238 | |
239 | package Foo; |
240 | use warnings; |
241 | use strict; |
242 | |
243 | use Carp qw(croak); # 'croak' will be removed |
244 | |
245 | sub bar { 23 } # 'bar' will be removed |
246 | |
247 | # remove all previously defined functions |
248 | use namespace::clean; |
249 | |
250 | sub baz { bar() } # 'baz' still defined, 'bar' still bound |
251 | |
252 | # begin to collection function names from here again |
253 | no namespace::clean; |
254 | |
255 | sub quux { baz() } # 'quux' will be removed |
256 | |
257 | # remove all functions defined after the 'no' unimport |
258 | use namespace::clean; |
259 | |
260 | # Will print: 'No', 'No', 'Yes' and 'No' |
261 | print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n"; |
262 | print +(__PACKAGE__->can('bar') ? 'Yes' : 'No'), "\n"; |
263 | print +(__PACKAGE__->can('baz') ? 'Yes' : 'No'), "\n"; |
264 | print +(__PACKAGE__->can('quux') ? 'Yes' : 'No'), "\n"; |
265 | |
266 | 1; |
267 | |
268 | =head1 DESCRIPTION |
269 | |
270 | =head2 Keeping packages clean |
271 | |
272 | When you define a function, or import one, into a Perl package, it will |
273 | naturally also be available as a method. This does not per se cause |
274 | problems, but it can complicate subclassing and, for example, plugin |
275 | classes that are included via multiple inheritance by loading them as |
276 | base classes. |
277 | |
278 | The C<namespace::clean> pragma will remove all previously declared or |
279 | imported symbols at the end of the current package's compile cycle. |
280 | Functions called in the package itself will still be bound by their |
281 | name, but they won't show up as methods on your class or instances. |
282 | |
283 | By unimporting via C<no> you can tell C<namespace::clean> to start |
284 | collecting functions for the next C<use namespace::clean;> specification. |
285 | |
286 | You can use the C<-except> flag to tell C<namespace::clean> that you |
287 | don't want it to remove a certain function or method. A common use would |
288 | be a module exporting an C<import> method along with some functions: |
289 | |
290 | use ModuleExportingImport; |
291 | use namespace::clean -except => [qw( import )]; |
292 | |
293 | If you just want to C<-except> a single sub, you can pass it directly. |
294 | For more than one value you have to use an array reference. |
295 | |
296 | =head2 Explicitly removing functions when your scope is compiled |
297 | |
298 | It is also possible to explicitly tell C<namespace::clean> what packages |
299 | to remove when the surrounding scope has finished compiling. Here is an |
300 | example: |
301 | |
302 | package Foo; |
303 | use strict; |
304 | |
305 | # blessed NOT available |
306 | |
307 | sub my_class { |
308 | use Scalar::Util qw( blessed ); |
309 | use namespace::clean qw( blessed ); |
310 | |
311 | # blessed available |
312 | return blessed shift; |
313 | } |
314 | |
315 | # blessed NOT available |
316 | |
317 | =head2 Moose |
318 | |
319 | When using C<namespace::clean> together with L<Moose> you want to keep |
320 | the installed C<meta> method. So your classes should look like: |
321 | |
322 | package Foo; |
323 | use Moose; |
324 | use namespace::clean -except => 'meta'; |
325 | ... |
326 | |
327 | Same goes for L<Moose::Role>. |
328 | |
329 | =head2 Cleaning other packages |
330 | |
331 | You can tell C<namespace::clean> that you want to clean up another package |
332 | instead of the one importing. To do this you have to pass in the C<-cleanee> |
333 | option like this: |
334 | |
335 | package My::MooseX::namespace::clean; |
336 | use strict; |
337 | |
338 | use namespace::clean (); # no cleanup, just load |
339 | |
340 | sub import { |
341 | namespace::clean->import( |
342 | -cleanee => scalar(caller), |
343 | -except => 'meta', |
344 | ); |
345 | } |
346 | |
347 | If you don't care about C<namespace::clean>s discover-and-C<-except> logic, and |
348 | just want to remove subroutines, try L</clean_subroutines>. |
349 | |
350 | =head1 METHODS |
351 | |
352 | =head2 clean_subroutines |
353 | |
354 | This exposes the actual subroutine-removal logic. |
355 | |
356 | namespace::clean->clean_subroutines($cleanee, qw( subA subB )); |
357 | |
358 | will remove C<subA> and C<subB> from C<$cleanee>. Note that this will remove the |
359 | subroutines B<immediately> and not wait for scope end. If you want to have this |
360 | effect at a specific time (e.g. C<namespace::clean> acts on scope compile end) |
361 | it is your responsibility to make sure it runs at that time. |
362 | |
363 | =head2 import |
364 | |
365 | Makes a snapshot of the current defined functions and installs a |
366 | L<B::Hooks::EndOfScope> hook in the current scope to invoke the cleanups. |
367 | |
368 | |
369 | =head2 unimport |
370 | |
371 | This method will be called when you do a |
372 | |
373 | no namespace::clean; |
374 | |
375 | It will start a new section of code that defines functions to clean up. |
376 | |
377 | =head2 get_class_store |
378 | |
379 | This returns a reference to a hash in a passed package containing |
380 | information about function names included and excluded from removal. |
381 | |
382 | =head2 get_functions |
383 | |
384 | Takes a class as argument and returns all currently defined functions |
385 | in it as a hash reference with the function name as key and a typeglob |
386 | reference to the symbol as value. |
387 | |
6c0ece9b |
388 | =head1 IMPLEMENTATION DETAILS |
389 | |
04312494 |
390 | This module works through the effect that a |
6c0ece9b |
391 | |
392 | delete $SomePackage::{foo}; |
393 | |
394 | will remove the C<foo> symbol from C<$SomePackage> for run time lookups |
395 | (e.g., method calls) but will leave the entry alive to be called by |
472d4b1e |
396 | already resolved names in the package itself. C<namespace::clean> will |
397 | restore and therefor in effect keep all glob slots that aren't C<CODE>. |
6c0ece9b |
398 | |
399 | A test file has been added to the perl core to ensure that this behaviour |
400 | will be stable in future releases. |
401 | |
402 | Just for completeness sake, if you want to remove the symbol completely, |
403 | use C<undef> instead. |
404 | |
40aef9d6 |
405 | =head1 SEE ALSO |
406 | |
705fe1b1 |
407 | L<B::Hooks::EndOfScope> |
40aef9d6 |
408 | |
04312494 |
409 | =head1 THANKS |
40aef9d6 |
410 | |
04312494 |
411 | Many thanks to Matt S Trout for the inspiration on the whole idea. |
40aef9d6 |
412 | |
fa84e425 |
413 | =head1 AUTHORS |
414 | |
415 | =over |
416 | |
417 | =item * |
418 | |
419 | Robert 'phaylon' Sedlacek <rs@474.at> |
420 | |
421 | =item * |
422 | |
423 | Florian Ragwitz <rafl@debian.org> |
424 | |
425 | =item * |
426 | |
427 | Jesse Luehrs <doy@tozt.net> |
428 | |
429 | =item * |
430 | |
431 | Peter Rabbitson <ribasushi@cpan.org> |
432 | |
b2e54862 |
433 | =item * |
434 | |
435 | Father Chrysostomos <sprout@cpan.org> |
436 | |
fa84e425 |
437 | =back |
438 | |
439 | =head1 COPYRIGHT AND LICENSE |
440 | |
b2e54862 |
441 | This software is copyright (c) 2011 by L</AUTHORS> |
fa84e425 |
442 | |
443 | This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. |