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2905fb35 |
1 | package Package::Stash::PP; |
f10f6217 |
2 | use strict; |
3 | use warnings; |
2905fb35 |
4 | # ABSTRACT: pure perl implementation of the Package::Stash API |
f10f6217 |
5 | |
7ef54f40 |
6 | use B; |
f10f6217 |
7 | use Carp qw(confess); |
eb53b1bd |
8 | use Scalar::Util qw(blessed reftype weaken); |
dc378b60 |
9 | use Symbol; |
10 | # before 5.12, assigning to the ISA glob would make it lose its magical ->isa |
11 | # powers |
12 | use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012); |
36cbfbad |
13 | # before 5.10, stashes don't ever seem to drop to a refcount of zero, so |
14 | # weakening them isn't helpful |
15 | use constant BROKEN_WEAK_STASH => ($] < 5.010); |
7ef54f40 |
16 | # before 5.10, the scalar slot was always treated as existing if the |
17 | # glob existed |
18 | use constant BROKEN_SCALAR_INITIALIZATION => ($] < 5.010); |
d93368f6 |
19 | # add_method on anon stashes triggers rt.perl #1804 otherwise |
20 | # fixed in perl commit v5.13.3-70-g0fe688f |
21 | use constant BROKEN_GLOB_ASSIGNMENT => ($] < 5.013004); |
f4979588 |
22 | |
f4979588 |
23 | =head1 SYNOPSIS |
24 | |
2905fb35 |
25 | use Package::Stash; |
f4979588 |
26 | |
27 | =head1 DESCRIPTION |
28 | |
2905fb35 |
29 | This is a backend for L<Package::Stash> implemented in pure perl, for those without a compiler or who would like to use this inline in scripts. |
f4979588 |
30 | |
31 | =cut |
32 | |
f10f6217 |
33 | sub new { |
34 | my $class = shift; |
e55970bc |
35 | my ($package) = @_; |
774f4f10 |
36 | |
91a61819 |
37 | if (!defined($package) || (ref($package) && reftype($package) ne 'HASH')) { |
774f4f10 |
38 | confess "Package::Stash->new must be passed the name of the " |
39 | . "package to access"; |
40 | } |
91a61819 |
41 | elsif (ref($package) && reftype($package) eq 'HASH') { |
d93368f6 |
42 | confess "The PP implementation of Package::Stash does not support " |
43 | . "anonymous stashes before perl 5.14" |
44 | if BROKEN_GLOB_ASSIGNMENT; |
45 | |
91a61819 |
46 | return bless { |
47 | 'namespace' => $package, |
48 | }, $class; |
774f4f10 |
49 | } |
91a61819 |
50 | elsif ($package =~ /\A[0-9A-Z_a-z]+(?:::[0-9A-Z_a-z]+)*\z/) { |
51 | return bless { |
52 | 'package' => $package, |
53 | }, $class; |
54 | } |
55 | else { |
ed131e41 |
56 | confess "$package is not a module name"; |
57 | } |
774f4f10 |
58 | |
f10f6217 |
59 | } |
60 | |
61 | sub name { |
2905fb35 |
62 | confess "Can't call name as a class method" |
63 | unless blessed($_[0]); |
91a61819 |
64 | confess "Can't get the name of an anonymous package" |
65 | unless defined($_[0]->{package}); |
f10f6217 |
66 | return $_[0]->{package}; |
67 | } |
68 | |
69 | sub namespace { |
2905fb35 |
70 | confess "Can't call namespace as a class method" |
71 | unless blessed($_[0]); |
eb53b1bd |
72 | |
36cbfbad |
73 | if (BROKEN_WEAK_STASH) { |
eb53b1bd |
74 | no strict 'refs'; |
36cbfbad |
75 | return \%{$_[0]->name . '::'}; |
eb53b1bd |
76 | } |
36cbfbad |
77 | else { |
78 | return $_[0]->{namespace} if defined $_[0]->{namespace}; |
eb53b1bd |
79 | |
36cbfbad |
80 | { |
81 | no strict 'refs'; |
82 | $_[0]->{namespace} = \%{$_[0]->name . '::'}; |
83 | } |
84 | |
85 | weaken($_[0]->{namespace}); |
eb53b1bd |
86 | |
36cbfbad |
87 | return $_[0]->{namespace}; |
88 | } |
f10f6217 |
89 | } |
90 | |
91 | { |
92 | my %SIGIL_MAP = ( |
93 | '$' => 'SCALAR', |
94 | '@' => 'ARRAY', |
95 | '%' => 'HASH', |
96 | '&' => 'CODE', |
56a29840 |
97 | '' => 'IO', |
f10f6217 |
98 | ); |
99 | |
100 | sub _deconstruct_variable_name { |
101 | my ($self, $variable) = @_; |
102 | |
6a42a16c |
103 | my @ret; |
104 | if (ref($variable) eq 'HASH') { |
105 | @ret = @{$variable}{qw[name sigil type]}; |
106 | } |
107 | else { |
108 | (defined $variable && length $variable) |
109 | || confess "You must pass a variable name"; |
110 | |
111 | my $sigil = substr($variable, 0, 1, ''); |
112 | |
113 | if (exists $SIGIL_MAP{$sigil}) { |
114 | @ret = ($variable, $sigil, $SIGIL_MAP{$sigil}); |
115 | } |
116 | else { |
117 | @ret = ("${sigil}${variable}", '', $SIGIL_MAP{''}); |
118 | } |
119 | } |
f10f6217 |
120 | |
875d2d1d |
121 | # XXX in pure perl, this will access things in inner packages, |
122 | # in xs, this will segfault - probably look more into this at |
123 | # some point |
6a42a16c |
124 | ($ret[0] !~ /::/) |
875d2d1d |
125 | || confess "Variable names may not contain ::"; |
126 | |
6a42a16c |
127 | return @ret; |
f10f6217 |
128 | } |
129 | } |
130 | |
3634ce60 |
131 | sub _valid_for_type { |
132 | my $self = shift; |
133 | my ($value, $type) = @_; |
134 | if ($type eq 'HASH' || $type eq 'ARRAY' |
135 | || $type eq 'IO' || $type eq 'CODE') { |
136 | return reftype($value) eq $type; |
137 | } |
138 | else { |
139 | my $ref = reftype($value); |
d173d3a3 |
140 | return !defined($ref) || $ref eq 'SCALAR' || $ref eq 'REF' || $ref eq 'LVALUE' || $ref eq 'REGEXP' || $ref eq 'VSTRING'; |
3634ce60 |
141 | } |
142 | } |
143 | |
2905fb35 |
144 | sub add_symbol { |
640de369 |
145 | my ($self, $variable, $initial_value, %opts) = @_; |
f10f6217 |
146 | |
6a42a16c |
147 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
148 | |
3634ce60 |
149 | if (@_ > 2) { |
150 | $self->_valid_for_type($initial_value, $type) |
151 | || confess "$initial_value is not of type $type"; |
3634ce60 |
152 | |
4ada57e0 |
153 | # cheap fail-fast check for PERLDBf_SUBLINE and '&' |
154 | if ($^P and $^P & 0x10 && $sigil eq '&') { |
640de369 |
155 | my $filename = $opts{filename}; |
156 | my $first_line_num = $opts{first_line_num}; |
4ada57e0 |
157 | |
640de369 |
158 | (undef, $filename, $first_line_num) = caller |
4ada57e0 |
159 | if not defined $filename; |
640de369 |
160 | |
161 | my $last_line_num = $opts{last_line_num} || ($first_line_num ||= 0); |
4ada57e0 |
162 | |
163 | # http://perldoc.perl.org/perldebguts.html#Debugger-Internals |
50419d91 |
164 | $DB::sub{$self->name . '::' . $name} = "$filename:$first_line_num-$last_line_num"; |
4ada57e0 |
165 | } |
166 | } |
f10f6217 |
167 | |
d93368f6 |
168 | if (BROKEN_GLOB_ASSIGNMENT) { |
169 | if (@_ > 2) { |
170 | no strict 'refs'; |
171 | *{ $self->name . '::' . $name } = ref $initial_value |
172 | ? $initial_value : \$initial_value; |
173 | } |
174 | else { |
175 | no strict 'refs'; |
176 | *{ $self->name . '::' . $name }; |
177 | } |
178 | } |
179 | else { |
180 | my $namespace = $self->namespace; |
181 | $namespace->{$name} ||= *{ Symbol::gensym() }; |
0f40e41f |
182 | |
d93368f6 |
183 | if (@_ > 2) { |
184 | *{ $namespace->{$name} } = ref $initial_value |
185 | ? $initial_value : \$initial_value; |
186 | } |
0f40e41f |
187 | } |
f10f6217 |
188 | } |
189 | |
2905fb35 |
190 | sub remove_glob { |
f10f6217 |
191 | my ($self, $name) = @_; |
65b8253b |
192 | delete $self->namespace->{$name}; |
f10f6217 |
193 | } |
194 | |
2905fb35 |
195 | sub has_symbol { |
f10f6217 |
196 | my ($self, $variable) = @_; |
197 | |
6a42a16c |
198 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
199 | |
200 | my $namespace = $self->namespace; |
201 | |
202 | return unless exists $namespace->{$name}; |
203 | |
204 | my $entry_ref = \$namespace->{$name}; |
205 | if (reftype($entry_ref) eq 'GLOB') { |
f7543739 |
206 | if ($type eq 'SCALAR') { |
7ef54f40 |
207 | if (BROKEN_SCALAR_INITIALIZATION) { |
208 | return defined ${ *{$entry_ref}{$type} }; |
209 | } |
210 | else { |
211 | return B::svref_2object($entry_ref)->SV->isa('B::SV'); |
212 | } |
f7543739 |
213 | } |
214 | else { |
215 | return defined *{$entry_ref}{$type}; |
216 | } |
f10f6217 |
217 | } |
218 | else { |
219 | # a symbol table entry can be -1 (stub), string (stub with prototype), |
220 | # or reference (constant) |
221 | return $type eq 'CODE'; |
222 | } |
223 | } |
224 | |
2905fb35 |
225 | sub get_symbol { |
e55803fc |
226 | my ($self, $variable, %opts) = @_; |
f10f6217 |
227 | |
6a42a16c |
228 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
229 | |
230 | my $namespace = $self->namespace; |
231 | |
7486ccf3 |
232 | if (!exists $namespace->{$name}) { |
dc378b60 |
233 | if ($opts{vivify}) { |
234 | if ($type eq 'ARRAY') { |
235 | if (BROKEN_ISA_ASSIGNMENT) { |
2905fb35 |
236 | $self->add_symbol( |
dc378b60 |
237 | $variable, |
238 | $name eq 'ISA' ? () : ([]) |
239 | ); |
240 | } |
241 | else { |
2905fb35 |
242 | $self->add_symbol($variable, []); |
dc378b60 |
243 | } |
244 | } |
245 | elsif ($type eq 'HASH') { |
2905fb35 |
246 | $self->add_symbol($variable, {}); |
dc378b60 |
247 | } |
248 | elsif ($type eq 'SCALAR') { |
2905fb35 |
249 | $self->add_symbol($variable); |
dc378b60 |
250 | } |
251 | elsif ($type eq 'IO') { |
2905fb35 |
252 | $self->add_symbol($variable, Symbol::geniosym); |
dc378b60 |
253 | } |
254 | elsif ($type eq 'CODE') { |
255 | confess "Don't know how to vivify CODE variables"; |
256 | } |
257 | else { |
258 | confess "Unknown type $type in vivication"; |
259 | } |
5d3589c8 |
260 | } |
e55803fc |
261 | else { |
4723417a |
262 | return undef; |
e55803fc |
263 | } |
30d1a098 |
264 | } |
f10f6217 |
265 | |
266 | my $entry_ref = \$namespace->{$name}; |
267 | |
268 | if (ref($entry_ref) eq 'GLOB') { |
269 | return *{$entry_ref}{$type}; |
270 | } |
271 | else { |
272 | if ($type eq 'CODE') { |
d6213159 |
273 | # XXX we should really be able to support arbitrary anonymous |
274 | # stashes here... (not just via Package::Anon) |
d93368f6 |
275 | if (!BROKEN_GLOB_ASSIGNMENT |
276 | && blessed($namespace) |
277 | && $namespace->isa('Package::Anon')) { |
d6213159 |
278 | # ->can will call gv_init for us |
279 | $namespace->bless(\(my $foo))->can($name); |
280 | return *{ $namespace->{$name} }{CODE}; |
281 | } |
282 | else { |
283 | no strict 'refs'; |
284 | return \&{ $self->name . '::' . $name }; |
285 | } |
f10f6217 |
286 | } |
287 | else { |
288 | return undef; |
289 | } |
290 | } |
291 | } |
292 | |
2905fb35 |
293 | sub get_or_add_symbol { |
e55803fc |
294 | my $self = shift; |
2905fb35 |
295 | $self->get_symbol(@_, vivify => 1); |
e55803fc |
296 | } |
297 | |
2905fb35 |
298 | sub remove_symbol { |
f10f6217 |
299 | my ($self, $variable) = @_; |
300 | |
6a42a16c |
301 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
302 | |
303 | # FIXME: |
9a3d1390 |
304 | # no doubt this is grossly inefficient and |
f10f6217 |
305 | # could be done much easier and faster in XS |
306 | |
b1a00d0e |
307 | my ($scalar_desc, $array_desc, $hash_desc, $code_desc, $io_desc) = ( |
f10f6217 |
308 | { sigil => '$', type => 'SCALAR', name => $name }, |
309 | { sigil => '@', type => 'ARRAY', name => $name }, |
310 | { sigil => '%', type => 'HASH', name => $name }, |
311 | { sigil => '&', type => 'CODE', name => $name }, |
b1a00d0e |
312 | { sigil => '', type => 'IO', name => $name }, |
f10f6217 |
313 | ); |
314 | |
b1a00d0e |
315 | my ($scalar, $array, $hash, $code, $io); |
f10f6217 |
316 | if ($type eq 'SCALAR') { |
2905fb35 |
317 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
318 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
319 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
320 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
321 | } |
322 | elsif ($type eq 'ARRAY') { |
7ef54f40 |
323 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
324 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
325 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
326 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
327 | } |
328 | elsif ($type eq 'HASH') { |
7ef54f40 |
329 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
330 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
331 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
332 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
333 | } |
334 | elsif ($type eq 'CODE') { |
7ef54f40 |
335 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
336 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
337 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
338 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
b1a00d0e |
339 | } |
340 | elsif ($type eq 'IO') { |
7ef54f40 |
341 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
342 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
343 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
344 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
f10f6217 |
345 | } |
346 | else { |
347 | confess "This should never ever ever happen"; |
348 | } |
349 | |
2905fb35 |
350 | $self->remove_glob($name); |
f10f6217 |
351 | |
7ef54f40 |
352 | $self->add_symbol($scalar_desc => $scalar) if defined $scalar; |
2905fb35 |
353 | $self->add_symbol($array_desc => $array) if defined $array; |
354 | $self->add_symbol($hash_desc => $hash) if defined $hash; |
355 | $self->add_symbol($code_desc => $code) if defined $code; |
356 | $self->add_symbol($io_desc => $io) if defined $io; |
f10f6217 |
357 | } |
358 | |
2905fb35 |
359 | sub list_all_symbols { |
f10f6217 |
360 | my ($self, $type_filter) = @_; |
361 | |
362 | my $namespace = $self->namespace; |
363 | return keys %{$namespace} unless defined $type_filter; |
364 | |
365 | # NOTE: |
9a3d1390 |
366 | # or we can filter based on |
f10f6217 |
367 | # type (SCALAR|ARRAY|HASH|CODE) |
368 | if ($type_filter eq 'CODE') { |
369 | return grep { |
25c87f5c |
370 | # any non-typeglob in the symbol table is a constant or stub |
371 | ref(\$namespace->{$_}) ne 'GLOB' |
372 | # regular subs are stored in the CODE slot of the typeglob |
d1f721b3 |
373 | || defined(*{$namespace->{$_}}{CODE}) |
374 | } keys %{$namespace}; |
375 | } |
376 | elsif ($type_filter eq 'SCALAR') { |
377 | return grep { |
7ef54f40 |
378 | BROKEN_SCALAR_INITIALIZATION |
379 | ? (ref(\$namespace->{$_}) eq 'GLOB' |
380 | && defined(${*{$namespace->{$_}}{'SCALAR'}})) |
381 | : (do { |
382 | my $entry = \$namespace->{$_}; |
383 | ref($entry) eq 'GLOB' |
384 | && B::svref_2object($entry)->SV->isa('B::SV') |
385 | }) |
d1f721b3 |
386 | } keys %{$namespace}; |
387 | } |
388 | else { |
389 | return grep { |
390 | ref(\$namespace->{$_}) eq 'GLOB' |
391 | && defined(*{$namespace->{$_}}{$type_filter}) |
f10f6217 |
392 | } keys %{$namespace}; |
f10f6217 |
393 | } |
394 | } |
f4979588 |
395 | |
2905fb35 |
396 | sub get_all_symbols { |
397 | my ($self, $type_filter) = @_; |
398 | |
399 | my $namespace = $self->namespace; |
400 | return { %{$namespace} } unless defined $type_filter; |
401 | |
402 | return { |
403 | map { $_ => $self->get_symbol({name => $_, type => $type_filter}) } |
404 | $self->list_all_symbols($type_filter) |
405 | } |
406 | } |
407 | |
0992f4ec |
408 | =head1 BUGS |
409 | |
2905fb35 |
410 | =over 4 |
411 | |
2905fb35 |
412 | =item * remove_symbol also replaces the associated typeglob |
413 | |
414 | This can cause unexpected behavior when doing manipulation at compile time - |
415 | removing subroutines will still allow them to be called from within the package |
416 | as subroutines (although they will not be available as methods). This can be |
417 | considered a feature in some cases (this is how L<namespace::clean> works, for |
418 | instance), but should not be relied upon - use C<remove_glob> directly if you |
419 | want this behavior. |
420 | |
cdb543b5 |
421 | =item * Some minor memory leaks |
422 | |
423 | The pure perl implementation has a couple minor memory leaks (see the TODO |
424 | tests in t/20-leaks.t) that I'm having a hard time tracking down - these may be |
425 | core perl bugs, it's hard to tell. |
426 | |
2905fb35 |
427 | =back |
0992f4ec |
428 | |
429 | Please report any bugs through RT: email |
430 | C<bug-package-stash at rt.cpan.org>, or browse to |
431 | L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Package-Stash>. |
432 | |
f4979588 |
433 | =head1 SEE ALSO |
434 | |
f4979588 |
435 | =over 4 |
436 | |
988beb41 |
437 | =item * L<Class::MOP::Package> |
f4979588 |
438 | |
988beb41 |
439 | This module is a factoring out of code that used to live here |
f4979588 |
440 | |
441 | =back |
442 | |
0992f4ec |
443 | =head1 SUPPORT |
444 | |
445 | You can find this documentation for this module with the perldoc command. |
446 | |
447 | perldoc Package::Stash |
448 | |
449 | You can also look for information at: |
450 | |
451 | =over 4 |
452 | |
453 | =item * AnnoCPAN: Annotated CPAN documentation |
454 | |
455 | L<http://annocpan.org/dist/Package-Stash> |
456 | |
457 | =item * CPAN Ratings |
458 | |
459 | L<http://cpanratings.perl.org/d/Package-Stash> |
460 | |
461 | =item * RT: CPAN's request tracker |
462 | |
463 | L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Package-Stash> |
464 | |
465 | =item * Search CPAN |
466 | |
467 | L<http://search.cpan.org/dist/Package-Stash> |
468 | |
469 | =back |
470 | |
471 | =head1 AUTHOR |
472 | |
473 | Jesse Luehrs <doy at tozt dot net> |
474 | |
475 | Mostly copied from code from L<Class::MOP::Package>, by Stevan Little and the |
476 | Moose Cabal. |
477 | |
a912fc4b |
478 | =begin Pod::Coverage |
479 | |
480 | BROKEN_ISA_ASSIGNMENT |
481 | add_symbol |
482 | get_all_symbols |
483 | get_or_add_symbol |
484 | get_symbol |
485 | has_symbol |
486 | list_all_symbols |
487 | name |
488 | namespace |
489 | new |
490 | remove_glob |
491 | |
492 | =end Pod::Coverage |
493 | |
f4979588 |
494 | =cut |
495 | |
496 | 1; |