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954c1994 |
1 | =head1 NAME |
2 | |
1c846c1f |
3 | perlintern - autogenerated documentation of purely B<internal> |
954c1994 |
4 | Perl functions |
5 | |
6 | =head1 DESCRIPTION |
d8c40edc |
7 | X<internal Perl functions> X<interpreter functions> |
954c1994 |
8 | |
1c846c1f |
9 | This file is the autogenerated documentation of functions in the |
4375e838 |
10 | Perl interpreter that are documented using Perl's internal documentation |
1c846c1f |
11 | format but are not marked as part of the Perl API. In other words, |
954c1994 |
12 | B<they are not for use in extensions>! |
13 | |
a8586c98 |
14 | |
7dafbf52 |
15 | =head1 CV reference counts and CvOUTSIDE |
16 | |
17 | =over 8 |
18 | |
19 | =item CvWEAKOUTSIDE |
d8c40edc |
20 | X<CvWEAKOUTSIDE> |
7dafbf52 |
21 | |
22 | Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing |
23 | CV (if any). Because pointers to anonymous sub prototypes are |
24 | stored in C<&> pad slots, it is a possible to get a circular reference, |
25 | with the parent pointing to the child and vice-versa. To avoid the |
26 | ensuing memory leak, we do not increment the reference count of the CV |
27 | pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent |
28 | has a C<&> pad slot pointing back to us. In this case, we set the |
29 | C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what |
30 | circumstances we should decrement the refcount of the parent when freeing |
31 | the child. |
32 | |
28a5cf3b |
33 | There is a further complication with non-closure anonymous subs (i.e. those |
7dafbf52 |
34 | that do not refer to any lexicals outside that sub). In this case, the |
35 | anonymous prototype is shared rather than being cloned. This has the |
36 | consequence that the parent may be freed while there are still active |
37 | children, eg |
38 | |
39 | BEGIN { $a = sub { eval '$x' } } |
40 | |
41 | In this case, the BEGIN is freed immediately after execution since there |
42 | are no active references to it: the anon sub prototype has |
43 | C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same |
44 | CV, so it doesn't contribute to BEGIN's refcount either. When $a is |
45 | executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, |
46 | and the freed BEGIN is accessed. |
47 | |
48 | To avoid this, whenever a CV and its associated pad is freed, any |
49 | C<&> entries in the pad are explicitly removed from the pad, and if the |
50 | refcount of the pointed-to anon sub is still positive, then that |
51 | child's C<CvOUTSIDE> is set to point to its grandparent. This will only |
52 | occur in the single specific case of a non-closure anon prototype |
53 | having one or more active references (such as C<$a> above). |
54 | |
55 | One other thing to consider is that a CV may be merely undefined |
56 | rather than freed, eg C<undef &foo>. In this case, its refcount may |
57 | not have reached zero, but we still delete its pad and its C<CvROOT> etc. |
58 | Since various children may still have their C<CvOUTSIDE> pointing at this |
59 | undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that |
60 | the chain of lexical scopes is unbroken. For example, the following |
61 | should print 123: |
62 | |
63 | my $x = 123; |
64 | sub tmp { sub { eval '$x' } } |
65 | my $a = tmp(); |
66 | undef &tmp; |
67 | print $a->(); |
68 | |
69 | bool CvWEAKOUTSIDE(CV *cv) |
70 | |
71 | =for hackers |
72 | Found in file cv.h |
73 | |
74 | |
75 | =back |
76 | |
dd2155a4 |
77 | =head1 Functions in file pad.h |
78 | |
79 | |
80 | =over 8 |
81 | |
82 | =item CX_CURPAD_SAVE |
d8c40edc |
83 | X<CX_CURPAD_SAVE> |
dd2155a4 |
84 | |
85 | Save the current pad in the given context block structure. |
86 | |
87 | void CX_CURPAD_SAVE(struct context) |
88 | |
89 | =for hackers |
90 | Found in file pad.h |
91 | |
92 | =item CX_CURPAD_SV |
d8c40edc |
93 | X<CX_CURPAD_SV> |
dd2155a4 |
94 | |
95 | Access the SV at offset po in the saved current pad in the given |
96 | context block structure (can be used as an lvalue). |
97 | |
f3548bdc |
98 | SV * CX_CURPAD_SV(struct context, PADOFFSET po) |
dd2155a4 |
99 | |
100 | =for hackers |
101 | Found in file pad.h |
102 | |
d8c40edc |
103 | =item PAD_BASE_SV |
104 | X<PAD_BASE_SV> |
dd2155a4 |
105 | |
106 | Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist |
107 | |
d8c40edc |
108 | SV * PAD_BASE_SV(PADLIST padlist, PADOFFSET po) |
dd2155a4 |
109 | |
110 | =for hackers |
111 | Found in file pad.h |
112 | |
113 | =item PAD_CLONE_VARS |
d8c40edc |
114 | X<PAD_CLONE_VARS> |
dd2155a4 |
115 | |
116 | |CLONE_PARAMS* param |
117 | Clone the state variables associated with running and compiling pads. |
118 | |
119 | void PAD_CLONE_VARS(PerlInterpreter *proto_perl \) |
120 | |
121 | =for hackers |
122 | Found in file pad.h |
123 | |
124 | =item PAD_COMPNAME_FLAGS |
d8c40edc |
125 | X<PAD_COMPNAME_FLAGS> |
dd2155a4 |
126 | |
127 | Return the flags for the current compiling pad name |
128 | at offset C<po>. Assumes a valid slot entry. |
129 | |
130 | U32 PAD_COMPNAME_FLAGS(PADOFFSET po) |
131 | |
132 | =for hackers |
133 | Found in file pad.h |
134 | |
135 | =item PAD_COMPNAME_GEN |
d8c40edc |
136 | X<PAD_COMPNAME_GEN> |
dd2155a4 |
137 | |
138 | The generation number of the name at offset C<po> in the current |
139 | compiling pad (lvalue). Note that C<SvCUR> is hijacked for this purpose. |
140 | |
141 | STRLEN PAD_COMPNAME_GEN(PADOFFSET po) |
142 | |
143 | =for hackers |
144 | Found in file pad.h |
145 | |
27da23d5 |
146 | =item PAD_COMPNAME_GEN_set |
d8c40edc |
147 | X<PAD_COMPNAME_GEN_set> |
27da23d5 |
148 | |
149 | Sets the generation number of the name at offset C<po> in the current |
150 | ling pad (lvalue) to C<gen>. Note that C<SvCUR_set> is hijacked for this purpose. |
151 | |
152 | STRLEN PAD_COMPNAME_GEN_set(PADOFFSET po, int gen) |
153 | |
154 | =for hackers |
155 | Found in file pad.h |
156 | |
dd2155a4 |
157 | =item PAD_COMPNAME_OURSTASH |
d8c40edc |
158 | X<PAD_COMPNAME_OURSTASH> |
dd2155a4 |
159 | |
160 | Return the stash associated with an C<our> variable. |
161 | Assumes the slot entry is a valid C<our> lexical. |
162 | |
163 | HV * PAD_COMPNAME_OURSTASH(PADOFFSET po) |
164 | |
165 | =for hackers |
166 | Found in file pad.h |
167 | |
168 | =item PAD_COMPNAME_PV |
d8c40edc |
169 | X<PAD_COMPNAME_PV> |
dd2155a4 |
170 | |
171 | Return the name of the current compiling pad name |
172 | at offset C<po>. Assumes a valid slot entry. |
173 | |
174 | char * PAD_COMPNAME_PV(PADOFFSET po) |
175 | |
176 | =for hackers |
177 | Found in file pad.h |
178 | |
179 | =item PAD_COMPNAME_TYPE |
d8c40edc |
180 | X<PAD_COMPNAME_TYPE> |
dd2155a4 |
181 | |
182 | Return the type (stash) of the current compiling pad name at offset |
183 | C<po>. Must be a valid name. Returns null if not typed. |
184 | |
185 | HV * PAD_COMPNAME_TYPE(PADOFFSET po) |
186 | |
187 | =for hackers |
188 | Found in file pad.h |
189 | |
190 | =item PAD_DUP |
d8c40edc |
191 | X<PAD_DUP> |
dd2155a4 |
192 | |
193 | Clone a padlist. |
194 | |
195 | void PAD_DUP(PADLIST dstpad, PADLIST srcpad, CLONE_PARAMS* param) |
196 | |
197 | =for hackers |
198 | Found in file pad.h |
199 | |
f3548bdc |
200 | =item PAD_RESTORE_LOCAL |
d8c40edc |
201 | X<PAD_RESTORE_LOCAL> |
f3548bdc |
202 | |
203 | Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL() |
204 | |
205 | void PAD_RESTORE_LOCAL(PAD *opad) |
206 | |
207 | =for hackers |
208 | Found in file pad.h |
209 | |
210 | =item PAD_SAVE_LOCAL |
d8c40edc |
211 | X<PAD_SAVE_LOCAL> |
f3548bdc |
212 | |
213 | Save the current pad to the local variable opad, then make the |
214 | current pad equal to npad |
215 | |
216 | void PAD_SAVE_LOCAL(PAD *opad, PAD *npad) |
217 | |
218 | =for hackers |
219 | Found in file pad.h |
220 | |
dd2155a4 |
221 | =item PAD_SAVE_SETNULLPAD |
d8c40edc |
222 | X<PAD_SAVE_SETNULLPAD> |
dd2155a4 |
223 | |
224 | Save the current pad then set it to null. |
225 | |
226 | void PAD_SAVE_SETNULLPAD() |
227 | |
228 | =for hackers |
229 | Found in file pad.h |
230 | |
d8c40edc |
231 | =item PAD_SETSV |
232 | X<PAD_SETSV> |
dd2155a4 |
233 | |
234 | Set the slot at offset C<po> in the current pad to C<sv> |
235 | |
d8c40edc |
236 | SV * PAD_SETSV(PADOFFSET po, SV* sv) |
dd2155a4 |
237 | |
238 | =for hackers |
239 | Found in file pad.h |
240 | |
d8c40edc |
241 | =item PAD_SET_CUR |
242 | X<PAD_SET_CUR> |
dd2155a4 |
243 | |
244 | Set the current pad to be pad C<n> in the padlist, saving |
f54ba1c2 |
245 | the previous current pad. NB currently this macro expands to a string too |
246 | long for some compilers, so it's best to replace it with |
247 | |
248 | SAVECOMPPAD(); |
249 | PAD_SET_CUR_NOSAVE(padlist,n); |
250 | |
dd2155a4 |
251 | |
d8c40edc |
252 | void PAD_SET_CUR(PADLIST padlist, I32 n) |
dd2155a4 |
253 | |
254 | =for hackers |
255 | Found in file pad.h |
256 | |
d8c40edc |
257 | =item PAD_SET_CUR_NOSAVE |
258 | X<PAD_SET_CUR_NOSAVE> |
bf9cdc68 |
259 | |
260 | like PAD_SET_CUR, but without the save |
261 | |
d8c40edc |
262 | void PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n) |
bf9cdc68 |
263 | |
264 | =for hackers |
265 | Found in file pad.h |
266 | |
d8c40edc |
267 | =item PAD_SV |
268 | X<PAD_SV> |
dd2155a4 |
269 | |
270 | Get the value at offset C<po> in the current pad |
271 | |
d8c40edc |
272 | void PAD_SV(PADOFFSET po) |
dd2155a4 |
273 | |
274 | =for hackers |
275 | Found in file pad.h |
276 | |
d8c40edc |
277 | =item PAD_SVl |
278 | X<PAD_SVl> |
dd2155a4 |
279 | |
280 | Lightweight and lvalue version of C<PAD_SV>. |
281 | Get or set the value at offset C<po> in the current pad. |
282 | Unlike C<PAD_SV>, does not print diagnostics with -DX. |
283 | For internal use only. |
284 | |
d8c40edc |
285 | SV * PAD_SVl(PADOFFSET po) |
dd2155a4 |
286 | |
287 | =for hackers |
288 | Found in file pad.h |
289 | |
d8c40edc |
290 | =item SAVECLEARSV |
291 | X<SAVECLEARSV> |
dd2155a4 |
292 | |
28a5cf3b |
293 | Clear the pointed to pad value on scope exit. (i.e. the runtime action of 'my') |
dd2155a4 |
294 | |
d8c40edc |
295 | void SAVECLEARSV(SV **svp) |
dd2155a4 |
296 | |
297 | =for hackers |
298 | Found in file pad.h |
299 | |
300 | =item SAVECOMPPAD |
d8c40edc |
301 | X<SAVECOMPPAD> |
dd2155a4 |
302 | |
303 | save PL_comppad and PL_curpad |
304 | |
dd2155a4 |
305 | |
dd2155a4 |
306 | |
307 | |
308 | |
f3548bdc |
309 | void SAVECOMPPAD() |
dd2155a4 |
310 | |
311 | =for hackers |
312 | Found in file pad.h |
313 | |
d8c40edc |
314 | =item SAVEPADSV |
315 | X<SAVEPADSV> |
dd2155a4 |
316 | |
317 | Save a pad slot (used to restore after an iteration) |
318 | |
f3548bdc |
319 | XXX DAPM it would make more sense to make the arg a PADOFFSET |
d8c40edc |
320 | void SAVEPADSV(PADOFFSET po) |
dd2155a4 |
321 | |
322 | =for hackers |
323 | Found in file pad.h |
324 | |
325 | |
326 | =back |
327 | |
a3985cdc |
328 | =head1 Functions in file pp_ctl.c |
329 | |
330 | |
331 | =over 8 |
332 | |
333 | =item find_runcv |
d8c40edc |
334 | X<find_runcv> |
a3985cdc |
335 | |
336 | Locate the CV corresponding to the currently executing sub or eval. |
d819b83a |
337 | If db_seqp is non_null, skip CVs that are in the DB package and populate |
338 | *db_seqp with the cop sequence number at the point that the DB:: code was |
339 | entered. (allows debuggers to eval in the scope of the breakpoint rather |
324092c6 |
340 | than in the scope of the debugger itself). |
a3985cdc |
341 | |
d819b83a |
342 | CV* find_runcv(U32 *db_seqp) |
a3985cdc |
343 | |
344 | =for hackers |
345 | Found in file pp_ctl.c |
346 | |
347 | |
348 | =back |
349 | |
a4f1a029 |
350 | =head1 Global Variables |
78f9721b |
351 | |
a4f1a029 |
352 | =over 8 |
78f9721b |
353 | |
2eb25c99 |
354 | =item PL_DBsingle |
d8c40edc |
355 | X<PL_DBsingle> |
2eb25c99 |
356 | |
357 | When Perl is run in debugging mode, with the B<-d> switch, this SV is a |
358 | boolean which indicates whether subs are being single-stepped. |
359 | Single-stepping is automatically turned on after every step. This is the C |
360 | variable which corresponds to Perl's $DB::single variable. See |
361 | C<PL_DBsub>. |
362 | |
363 | SV * PL_DBsingle |
364 | |
365 | =for hackers |
366 | Found in file intrpvar.h |
367 | |
368 | =item PL_DBsub |
d8c40edc |
369 | X<PL_DBsub> |
2eb25c99 |
370 | |
371 | When Perl is run in debugging mode, with the B<-d> switch, this GV contains |
372 | the SV which holds the name of the sub being debugged. This is the C |
373 | variable which corresponds to Perl's $DB::sub variable. See |
374 | C<PL_DBsingle>. |
375 | |
376 | GV * PL_DBsub |
377 | |
378 | =for hackers |
379 | Found in file intrpvar.h |
380 | |
381 | =item PL_DBtrace |
d8c40edc |
382 | X<PL_DBtrace> |
2eb25c99 |
383 | |
384 | Trace variable used when Perl is run in debugging mode, with the B<-d> |
385 | switch. This is the C variable which corresponds to Perl's $DB::trace |
386 | variable. See C<PL_DBsingle>. |
387 | |
388 | SV * PL_DBtrace |
389 | |
390 | =for hackers |
391 | Found in file intrpvar.h |
392 | |
393 | =item PL_dowarn |
d8c40edc |
394 | X<PL_dowarn> |
2eb25c99 |
395 | |
396 | The C variable which corresponds to Perl's $^W warning variable. |
397 | |
398 | bool PL_dowarn |
399 | |
400 | =for hackers |
401 | Found in file intrpvar.h |
402 | |
403 | =item PL_last_in_gv |
d8c40edc |
404 | X<PL_last_in_gv> |
2eb25c99 |
405 | |
406 | The GV which was last used for a filehandle input operation. (C<< <FH> >>) |
407 | |
408 | GV* PL_last_in_gv |
409 | |
410 | =for hackers |
411 | Found in file thrdvar.h |
412 | |
413 | =item PL_ofs_sv |
d8c40edc |
414 | X<PL_ofs_sv> |
2eb25c99 |
415 | |
416 | The output field separator - C<$,> in Perl space. |
417 | |
418 | SV* PL_ofs_sv |
419 | |
420 | =for hackers |
421 | Found in file thrdvar.h |
422 | |
423 | =item PL_rs |
d8c40edc |
424 | X<PL_rs> |
2eb25c99 |
425 | |
426 | The input record separator - C<$/> in Perl space. |
427 | |
428 | SV* PL_rs |
429 | |
430 | =for hackers |
431 | Found in file thrdvar.h |
432 | |
645c22ef |
433 | |
a4f1a029 |
434 | =back |
645c22ef |
435 | |
a4f1a029 |
436 | =head1 GV Functions |
437 | |
438 | =over 8 |
439 | |
440 | =item is_gv_magical |
d8c40edc |
441 | X<is_gv_magical> |
a4f1a029 |
442 | |
443 | Returns C<TRUE> if given the name of a magical GV. |
444 | |
445 | Currently only useful internally when determining if a GV should be |
446 | created even in rvalue contexts. |
447 | |
448 | C<flags> is not used at present but available for future extension to |
449 | allow selecting particular classes of magical variable. |
450 | |
766f8916 |
451 | Currently assumes that C<name> is NUL terminated (as well as len being valid). |
452 | This assumption is met by all callers within the perl core, which all pass |
453 | pointers returned by SvPV. |
454 | |
7fc63493 |
455 | bool is_gv_magical(const char *name, STRLEN len, U32 flags) |
456 | |
457 | =for hackers |
458 | Found in file gv.c |
459 | |
460 | =item is_gv_magical_sv |
d8c40edc |
461 | X<is_gv_magical_sv> |
7fc63493 |
462 | |
463 | Returns C<TRUE> if given the name of a magical GV. Calls is_gv_magical. |
464 | |
465 | bool is_gv_magical_sv(SV *name, U32 flags) |
645c22ef |
466 | |
467 | =for hackers |
a4f1a029 |
468 | Found in file gv.c |
469 | |
470 | |
471 | =back |
472 | |
b3ca2e83 |
473 | =head1 Hash Manipulation Functions |
474 | |
475 | =over 8 |
476 | |
477 | =item refcounted_he_chain_2hv |
478 | X<refcounted_he_chain_2hv> |
479 | |
480 | Generates an returns a C<HV *> by walking up the tree starting at the passed |
481 | in C<struct refcounted_he *>. |
482 | |
483 | HV * refcounted_he_chain_2hv(const struct refcounted_he *c) |
484 | |
485 | =for hackers |
486 | Found in file hv.c |
487 | |
a24d89c9 |
488 | =item refcounted_he_copy |
489 | X<refcounted_he_copy> |
490 | |
491 | Copies a chain of C<struct refcounted_he *>. Used by C<pp_entereval>. |
492 | |
493 | struct refcounted_he * refcounted_he_copy(const struct refcounted_he *he) |
494 | |
495 | =for hackers |
496 | Found in file hv.c |
497 | |
b3ca2e83 |
498 | =item refcounted_he_dup |
499 | X<refcounted_he_dup> |
500 | |
501 | Duplicates the C<struct refcounted_he *> for a new thread. |
502 | |
503 | struct refcounted_he * refcounted_he_dup(const struct refcounted_he *const he, CLONE_PARAMS* param) |
504 | |
505 | =for hackers |
506 | Found in file hv.c |
507 | |
508 | =item refcounted_he_free |
509 | X<refcounted_he_free> |
510 | |
511 | Decrements the reference count of the passed in C<struct refcounted_he *> |
512 | by one. If the reference count reaches zero the structure's memory is freed, |
513 | and C<refcounted_he_free> iterates onto the parent node. |
514 | |
515 | void refcounted_he_free(struct refcounted_he *he) |
516 | |
517 | =for hackers |
518 | Found in file hv.c |
519 | |
520 | =item refcounted_he_new |
521 | X<refcounted_he_new> |
522 | |
523 | Creates a new C<struct refcounted_he>. Assumes ownership of one reference |
524 | to I<value>. As S<key> is copied into a shared hash key, all references remain |
525 | the property of the caller. The C<struct refcounted_he> is returned with a |
526 | reference count of 1. |
527 | |
a24d89c9 |
528 | struct refcounted_he * refcounted_he_new(struct refcounted_he *const parent, SV *key, SV *value) |
b3ca2e83 |
529 | |
530 | =for hackers |
531 | Found in file hv.c |
532 | |
533 | |
534 | =back |
535 | |
a4f1a029 |
536 | =head1 IO Functions |
537 | |
538 | =over 8 |
645c22ef |
539 | |
a8586c98 |
540 | =item start_glob |
d8c40edc |
541 | X<start_glob> |
a8586c98 |
542 | |
543 | Function called by C<do_readline> to spawn a glob (or do the glob inside |
544 | perl on VMS). This code used to be inline, but now perl uses C<File::Glob> |
bd16a5f0 |
545 | this glob starter is only used by miniperl during the build process. |
a8586c98 |
546 | Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up. |
547 | |
548 | PerlIO* start_glob(SV* pattern, IO *io) |
549 | |
550 | =for hackers |
551 | Found in file doio.c |
552 | |
a4f1a029 |
553 | |
554 | =back |
555 | |
0cbee0a4 |
556 | =head1 Magical Functions |
557 | |
558 | =over 8 |
559 | |
b3ca2e83 |
560 | =item magic_sethint |
561 | X<magic_sethint> |
562 | |
563 | Triggered by a delete from %^H, records the key to C<PL_compiling.cop_hints>. |
564 | |
565 | int magic_sethint(SV* sv, MAGIC* mg) |
566 | |
567 | =for hackers |
568 | Found in file mg.c |
569 | |
0cbee0a4 |
570 | =item mg_localize |
d8c40edc |
571 | X<mg_localize> |
0cbee0a4 |
572 | |
573 | Copy some of the magic from an existing SV to new localized version of |
574 | that SV. Container magic (eg %ENV, $1, tie) gets copied, value magic |
575 | doesn't (eg taint, pos). |
576 | |
577 | void mg_localize(SV* sv, SV* nsv) |
578 | |
579 | =for hackers |
580 | Found in file mg.c |
581 | |
582 | |
583 | =back |
584 | |
a4f1a029 |
585 | =head1 Pad Data Structures |
586 | |
587 | =over 8 |
588 | |
589 | =item CvPADLIST |
d8c40edc |
590 | X<CvPADLIST> |
a4f1a029 |
591 | |
592 | CV's can have CvPADLIST(cv) set to point to an AV. |
593 | |
594 | For these purposes "forms" are a kind-of CV, eval""s are too (except they're |
595 | not callable at will and are always thrown away after the eval"" is done |
b5c19bd7 |
596 | executing). Require'd files are simply evals without any outer lexical |
597 | scope. |
a4f1a029 |
598 | |
599 | XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad, |
600 | but that is really the callers pad (a slot of which is allocated by |
601 | every entersub). |
602 | |
603 | The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items |
f3548bdc |
604 | is managed "manual" (mostly in pad.c) rather than normal av.c rules. |
a4f1a029 |
605 | The items in the AV are not SVs as for a normal AV, but other AVs: |
606 | |
607 | 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather |
608 | the "static type information" for lexicals. |
609 | |
610 | The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that |
611 | depth of recursion into the CV. |
612 | The 0'th slot of a frame AV is an AV which is @_. |
613 | other entries are storage for variables and op targets. |
614 | |
615 | During compilation: |
a6d05634 |
616 | C<PL_comppad_name> is set to the names AV. |
617 | C<PL_comppad> is set to the frame AV for the frame CvDEPTH == 1. |
618 | C<PL_curpad> is set to the body of the frame AV (i.e. AvARRAY(PL_comppad)). |
a4f1a029 |
619 | |
f3548bdc |
620 | During execution, C<PL_comppad> and C<PL_curpad> refer to the live |
621 | frame of the currently executing sub. |
622 | |
623 | Iterating over the names AV iterates over all possible pad |
a4f1a029 |
624 | items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having |
625 | &PL_sv_undef "names" (see pad_alloc()). |
626 | |
627 | Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names. |
628 | The rest are op targets/GVs/constants which are statically allocated |
629 | or resolved at compile time. These don't have names by which they |
630 | can be looked up from Perl code at run time through eval"" like |
631 | my/our variables can be. Since they can't be looked up by "name" |
632 | but only by their index allocated at compile time (which is usually |
633 | in PL_op->op_targ), wasting a name SV for them doesn't make sense. |
634 | |
635 | The SVs in the names AV have their PV being the name of the variable. |
dd2155a4 |
636 | NV+1..IV inclusive is a range of cop_seq numbers for which the name is |
637 | valid. For typed lexicals name SV is SVt_PVMG and SvSTASH points at the |
b37c2d43 |
638 | type. For C<our> lexicals, the type is also SVt_PVGV, with the MAGIC slot |
639 | pointing at the stash of the associated global (so that duplicate C<our> |
640 | declarations in the same package can be detected). SvCUR is sometimes |
641 | hijacked to store the generation number during compilation. |
a4f1a029 |
642 | |
b5c19bd7 |
643 | If SvFAKE is set on the name SV, then that slot in the frame AV is |
644 | a REFCNT'ed reference to a lexical from "outside". In this case, |
645 | the name SV does not use NVX and IVX to store a cop_seq range, since it is |
646 | in scope throughout. Instead IVX stores some flags containing info about |
647 | the real lexical (is it declared in an anon, and is it capable of being |
648 | instantiated multiple times?), and for fake ANONs, NVX contains the index |
649 | within the parent's pad where the lexical's value is stored, to make |
650 | cloning quicker. |
a4f1a029 |
651 | |
a6d05634 |
652 | If the 'name' is '&' the corresponding entry in frame AV |
a4f1a029 |
653 | is a CV representing a possible closure. |
654 | (SvFAKE and name of '&' is not a meaningful combination currently but could |
655 | become so if C<my sub foo {}> is implemented.) |
656 | |
5c3943b6 |
657 | Note that formats are treated as anon subs, and are cloned each time |
658 | write is called (if necessary). |
659 | |
2814eb74 |
660 | The flag SVf_PADSTALE is cleared on lexicals each time the my() is executed, |
661 | and set on scope exit. This allows the 'Variable $x is not available' warning |
662 | to be generated in evals, such as |
663 | |
664 | { my $x = 1; sub f { eval '$x'} } f(); |
665 | |
a4f1a029 |
666 | AV * CvPADLIST(CV *cv) |
667 | |
668 | =for hackers |
dd2155a4 |
669 | Found in file pad.c |
670 | |
671 | =item cv_clone |
d8c40edc |
672 | X<cv_clone> |
dd2155a4 |
673 | |
674 | Clone a CV: make a new CV which points to the same code etc, but which |
ad63d80f |
675 | has a newly-created pad built by copying the prototype pad and capturing |
dd2155a4 |
676 | any outer lexicals. |
677 | |
678 | CV* cv_clone(CV* proto) |
679 | |
680 | =for hackers |
681 | Found in file pad.c |
682 | |
683 | =item cv_dump |
d8c40edc |
684 | X<cv_dump> |
dd2155a4 |
685 | |
686 | dump the contents of a CV |
687 | |
e1ec3a88 |
688 | void cv_dump(const CV *cv, const char *title) |
dd2155a4 |
689 | |
690 | =for hackers |
691 | Found in file pad.c |
692 | |
693 | =item do_dump_pad |
d8c40edc |
694 | X<do_dump_pad> |
dd2155a4 |
695 | |
696 | Dump the contents of a padlist |
697 | |
698 | void do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full) |
699 | |
700 | =for hackers |
701 | Found in file pad.c |
702 | |
703 | =item intro_my |
d8c40edc |
704 | X<intro_my> |
dd2155a4 |
705 | |
706 | "Introduce" my variables to visible status. |
707 | |
708 | U32 intro_my() |
709 | |
710 | =for hackers |
711 | Found in file pad.c |
712 | |
713 | =item pad_add_anon |
d8c40edc |
714 | X<pad_add_anon> |
dd2155a4 |
715 | |
716 | Add an anon code entry to the current compiling pad |
717 | |
718 | PADOFFSET pad_add_anon(SV* sv, OPCODE op_type) |
719 | |
720 | =for hackers |
721 | Found in file pad.c |
722 | |
723 | =item pad_add_name |
d8c40edc |
724 | X<pad_add_name> |
dd2155a4 |
725 | |
b5c19bd7 |
726 | Create a new name and associated PADMY SV in the current pad; return the |
727 | offset. |
dd2155a4 |
728 | If C<typestash> is valid, the name is for a typed lexical; set the |
729 | name's stash to that value. |
730 | If C<ourstash> is valid, it's an our lexical, set the name's |
b37c2d43 |
731 | OURSTASH to that value |
dd2155a4 |
732 | |
dd2155a4 |
733 | If fake, it means we're cloning an existing entry |
734 | |
e1ec3a88 |
735 | PADOFFSET pad_add_name(const char *name, HV* typestash, HV* ourstash, bool clone) |
dd2155a4 |
736 | |
737 | =for hackers |
738 | Found in file pad.c |
739 | |
740 | =item pad_alloc |
d8c40edc |
741 | X<pad_alloc> |
dd2155a4 |
742 | |
743 | Allocate a new my or tmp pad entry. For a my, simply push a null SV onto |
744 | the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards |
324092c6 |
745 | for a slot which has no name and no active value. |
dd2155a4 |
746 | |
747 | PADOFFSET pad_alloc(I32 optype, U32 tmptype) |
748 | |
749 | =for hackers |
750 | Found in file pad.c |
751 | |
752 | =item pad_block_start |
d8c40edc |
753 | X<pad_block_start> |
dd2155a4 |
754 | |
755 | Update the pad compilation state variables on entry to a new block |
756 | |
757 | void pad_block_start(int full) |
758 | |
759 | =for hackers |
760 | Found in file pad.c |
761 | |
762 | =item pad_check_dup |
d8c40edc |
763 | X<pad_check_dup> |
dd2155a4 |
764 | |
765 | Check for duplicate declarations: report any of: |
766 | * a my in the current scope with the same name; |
767 | * an our (anywhere in the pad) with the same name and the same stash |
768 | as C<ourstash> |
769 | C<is_our> indicates that the name to check is an 'our' declaration |
770 | |
e1ec3a88 |
771 | void pad_check_dup(const char* name, bool is_our, const HV* ourstash) |
dd2155a4 |
772 | |
773 | =for hackers |
774 | Found in file pad.c |
775 | |
776 | =item pad_findlex |
d8c40edc |
777 | X<pad_findlex> |
dd2155a4 |
778 | |
779 | Find a named lexical anywhere in a chain of nested pads. Add fake entries |
b5c19bd7 |
780 | in the inner pads if it's found in an outer one. |
781 | |
782 | Returns the offset in the bottom pad of the lex or the fake lex. |
783 | cv is the CV in which to start the search, and seq is the current cop_seq |
784 | to match against. If warn is true, print appropriate warnings. The out_* |
785 | vars return values, and so are pointers to where the returned values |
786 | should be stored. out_capture, if non-null, requests that the innermost |
787 | instance of the lexical is captured; out_name_sv is set to the innermost |
788 | matched namesv or fake namesv; out_flags returns the flags normally |
789 | associated with the IVX field of a fake namesv. |
790 | |
791 | Note that pad_findlex() is recursive; it recurses up the chain of CVs, |
792 | then comes back down, adding fake entries as it goes. It has to be this way |
793 | because fake namesvs in anon protoypes have to store in NVX the index into |
794 | the parent pad. |
795 | |
e1ec3a88 |
796 | PADOFFSET pad_findlex(const char *name, const CV* cv, U32 seq, int warn, SV** out_capture, SV** out_name_sv, int *out_flags) |
dd2155a4 |
797 | |
798 | =for hackers |
799 | Found in file pad.c |
800 | |
801 | =item pad_findmy |
d8c40edc |
802 | X<pad_findmy> |
dd2155a4 |
803 | |
ad63d80f |
804 | Given a lexical name, try to find its offset, first in the current pad, |
dd2155a4 |
805 | or failing that, in the pads of any lexically enclosing subs (including |
ad63d80f |
806 | the complications introduced by eval). If the name is found in an outer pad, |
807 | then a fake entry is added to the current pad. |
dd2155a4 |
808 | Returns the offset in the current pad, or NOT_IN_PAD on failure. |
809 | |
e1ec3a88 |
810 | PADOFFSET pad_findmy(const char* name) |
dd2155a4 |
811 | |
812 | =for hackers |
813 | Found in file pad.c |
814 | |
815 | =item pad_fixup_inner_anons |
d8c40edc |
816 | X<pad_fixup_inner_anons> |
dd2155a4 |
817 | |
818 | For any anon CVs in the pad, change CvOUTSIDE of that CV from |
7dafbf52 |
819 | old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be |
820 | moved to a pre-existing CV struct. |
dd2155a4 |
821 | |
822 | void pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv) |
823 | |
824 | =for hackers |
825 | Found in file pad.c |
826 | |
827 | =item pad_free |
d8c40edc |
828 | X<pad_free> |
dd2155a4 |
829 | |
d7f8936a |
830 | Free the SV at offset po in the current pad. |
dd2155a4 |
831 | |
832 | void pad_free(PADOFFSET po) |
833 | |
834 | =for hackers |
835 | Found in file pad.c |
836 | |
837 | =item pad_leavemy |
d8c40edc |
838 | X<pad_leavemy> |
dd2155a4 |
839 | |
840 | Cleanup at end of scope during compilation: set the max seq number for |
841 | lexicals in this scope and warn of any lexicals that never got introduced. |
842 | |
843 | void pad_leavemy() |
844 | |
845 | =for hackers |
846 | Found in file pad.c |
847 | |
848 | =item pad_new |
d8c40edc |
849 | X<pad_new> |
dd2155a4 |
850 | |
ad63d80f |
851 | Create a new compiling padlist, saving and updating the various global |
dd2155a4 |
852 | vars at the same time as creating the pad itself. The following flags |
853 | can be OR'ed together: |
854 | |
855 | padnew_CLONE this pad is for a cloned CV |
856 | padnew_SAVE save old globals |
857 | padnew_SAVESUB also save extra stuff for start of sub |
858 | |
c7c737cb |
859 | PADLIST* pad_new(int flags) |
dd2155a4 |
860 | |
861 | =for hackers |
862 | Found in file pad.c |
863 | |
864 | =item pad_push |
d8c40edc |
865 | X<pad_push> |
dd2155a4 |
866 | |
867 | Push a new pad frame onto the padlist, unless there's already a pad at |
26019298 |
868 | this depth, in which case don't bother creating a new one. Then give |
869 | the new pad an @_ in slot zero. |
dd2155a4 |
870 | |
26019298 |
871 | void pad_push(PADLIST *padlist, int depth) |
dd2155a4 |
872 | |
873 | =for hackers |
874 | Found in file pad.c |
875 | |
876 | =item pad_reset |
d8c40edc |
877 | X<pad_reset> |
dd2155a4 |
878 | |
879 | Mark all the current temporaries for reuse |
880 | |
881 | void pad_reset() |
882 | |
883 | =for hackers |
884 | Found in file pad.c |
885 | |
886 | =item pad_setsv |
d8c40edc |
887 | X<pad_setsv> |
dd2155a4 |
888 | |
889 | Set the entry at offset po in the current pad to sv. |
890 | Use the macro PAD_SETSV() rather than calling this function directly. |
891 | |
892 | void pad_setsv(PADOFFSET po, SV* sv) |
893 | |
894 | =for hackers |
895 | Found in file pad.c |
896 | |
897 | =item pad_swipe |
d8c40edc |
898 | X<pad_swipe> |
dd2155a4 |
899 | |
900 | Abandon the tmp in the current pad at offset po and replace with a |
901 | new one. |
902 | |
903 | void pad_swipe(PADOFFSET po, bool refadjust) |
904 | |
905 | =for hackers |
906 | Found in file pad.c |
907 | |
908 | =item pad_tidy |
d8c40edc |
909 | X<pad_tidy> |
dd2155a4 |
910 | |
911 | Tidy up a pad after we've finished compiling it: |
912 | * remove most stuff from the pads of anonsub prototypes; |
913 | * give it a @_; |
914 | * mark tmps as such. |
915 | |
916 | void pad_tidy(padtidy_type type) |
917 | |
918 | =for hackers |
919 | Found in file pad.c |
920 | |
921 | =item pad_undef |
d8c40edc |
922 | X<pad_undef> |
dd2155a4 |
923 | |
924 | Free the padlist associated with a CV. |
925 | If parts of it happen to be current, we null the relevant |
926 | PL_*pad* global vars so that we don't have any dangling references left. |
927 | We also repoint the CvOUTSIDE of any about-to-be-orphaned |
a3985cdc |
928 | inner subs to the outer of this cv. |
dd2155a4 |
929 | |
7dafbf52 |
930 | (This function should really be called pad_free, but the name was already |
931 | taken) |
932 | |
a3985cdc |
933 | void pad_undef(CV* cv) |
dd2155a4 |
934 | |
935 | =for hackers |
936 | Found in file pad.c |
a4f1a029 |
937 | |
938 | |
939 | =back |
940 | |
941 | =head1 Stack Manipulation Macros |
942 | |
943 | =over 8 |
944 | |
945 | =item djSP |
d8c40edc |
946 | X<djSP> |
a4f1a029 |
947 | |
948 | Declare Just C<SP>. This is actually identical to C<dSP>, and declares |
949 | a local copy of perl's stack pointer, available via the C<SP> macro. |
950 | See C<SP>. (Available for backward source code compatibility with the |
951 | old (Perl 5.005) thread model.) |
952 | |
953 | djSP; |
954 | |
955 | =for hackers |
956 | Found in file pp.h |
957 | |
958 | =item LVRET |
d8c40edc |
959 | X<LVRET> |
a4f1a029 |
960 | |
961 | True if this op will be the return value of an lvalue subroutine |
962 | |
963 | =for hackers |
964 | Found in file pp.h |
965 | |
966 | |
967 | =back |
968 | |
969 | =head1 SV Manipulation Functions |
970 | |
971 | =over 8 |
972 | |
645c22ef |
973 | =item sv_add_arena |
d8c40edc |
974 | X<sv_add_arena> |
645c22ef |
975 | |
976 | Given a chunk of memory, link it to the head of the list of arenas, |
977 | and split it into a list of free SVs. |
978 | |
979 | void sv_add_arena(char* ptr, U32 size, U32 flags) |
980 | |
981 | =for hackers |
982 | Found in file sv.c |
983 | |
984 | =item sv_clean_all |
d8c40edc |
985 | X<sv_clean_all> |
645c22ef |
986 | |
987 | Decrement the refcnt of each remaining SV, possibly triggering a |
988 | cleanup. This function may have to be called multiple times to free |
8fb26106 |
989 | SVs which are in complex self-referential hierarchies. |
645c22ef |
990 | |
991 | I32 sv_clean_all() |
992 | |
993 | =for hackers |
994 | Found in file sv.c |
995 | |
996 | =item sv_clean_objs |
d8c40edc |
997 | X<sv_clean_objs> |
645c22ef |
998 | |
999 | Attempt to destroy all objects not yet freed |
1000 | |
1001 | void sv_clean_objs() |
1002 | |
1003 | =for hackers |
1004 | Found in file sv.c |
1005 | |
1006 | =item sv_free_arenas |
d8c40edc |
1007 | X<sv_free_arenas> |
645c22ef |
1008 | |
1009 | Deallocate the memory used by all arenas. Note that all the individual SV |
1010 | heads and bodies within the arenas must already have been freed. |
1011 | |
1012 | void sv_free_arenas() |
1013 | |
1014 | =for hackers |
1015 | Found in file sv.c |
1016 | |
a4f1a029 |
1017 | |
954c1994 |
1018 | =back |
1019 | |
979f2922 |
1020 | =head1 Unicode Support |
1021 | |
1022 | =over 8 |
1023 | |
1024 | =item find_uninit_var |
1025 | X<find_uninit_var> |
1026 | |
1027 | Find the name of the undefined variable (if any) that caused the operator o |
1028 | to issue a "Use of uninitialized value" warning. |
1029 | If match is true, only return a name if it's value matches uninit_sv. |
1030 | So roughly speaking, if a unary operator (such as OP_COS) generates a |
1031 | warning, then following the direct child of the op may yield an |
1032 | OP_PADSV or OP_GV that gives the name of the undefined variable. On the |
1033 | other hand, with OP_ADD there are two branches to follow, so we only print |
1034 | the variable name if we get an exact match. |
1035 | |
1036 | The name is returned as a mortal SV. |
1037 | |
1038 | Assumes that PL_op is the op that originally triggered the error, and that |
1039 | PL_comppad/PL_curpad points to the currently executing pad. |
1040 | |
1041 | SV* find_uninit_var(OP* obase, SV* uninit_sv, bool top) |
1042 | |
1043 | =for hackers |
1044 | Found in file sv.c |
1045 | |
1046 | =item report_uninit |
1047 | X<report_uninit> |
1048 | |
1049 | Print appropriate "Use of uninitialized variable" warning |
1050 | |
1051 | void report_uninit(SV* uninit_sv) |
1052 | |
1053 | =for hackers |
1054 | Found in file sv.c |
1055 | |
1056 | |
1057 | =back |
1058 | |
954c1994 |
1059 | =head1 AUTHORS |
1060 | |
1c846c1f |
1061 | The autodocumentation system was originally added to the Perl core by |
1062 | Benjamin Stuhl. Documentation is by whoever was kind enough to |
954c1994 |
1063 | document their functions. |
1064 | |
1065 | =head1 SEE ALSO |
1066 | |
1067 | perlguts(1), perlapi(1) |
1068 | |