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3f98fbb3 RGS |
1 | -*- buffer-read-only: t -*- |
2 | ||
3 | !!!!!!! DO NOT EDIT THIS FILE !!!!!!! | |
4 | This file is built by autodoc.pl extracting documentation from the C source | |
5 | files. | |
6 | ||
954c1994 GS |
7 | =head1 NAME |
8 | ||
1c846c1f | 9 | perlintern - autogenerated documentation of purely B<internal> |
954c1994 GS |
10 | Perl functions |
11 | ||
12 | =head1 DESCRIPTION | |
d8c40edc | 13 | X<internal Perl functions> X<interpreter functions> |
954c1994 | 14 | |
1c846c1f | 15 | This file is the autogenerated documentation of functions in the |
4375e838 | 16 | Perl interpreter that are documented using Perl's internal documentation |
1c846c1f | 17 | format but are not marked as part of the Perl API. In other words, |
954c1994 GS |
18 | B<they are not for use in extensions>! |
19 | ||
a8586c98 | 20 | |
7dafbf52 DM |
21 | =head1 CV reference counts and CvOUTSIDE |
22 | ||
23 | =over 8 | |
24 | ||
25 | =item CvWEAKOUTSIDE | |
d8c40edc | 26 | X<CvWEAKOUTSIDE> |
7dafbf52 DM |
27 | |
28 | Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing | |
29 | CV (if any). Because pointers to anonymous sub prototypes are | |
30 | stored in C<&> pad slots, it is a possible to get a circular reference, | |
31 | with the parent pointing to the child and vice-versa. To avoid the | |
32 | ensuing memory leak, we do not increment the reference count of the CV | |
33 | pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent | |
34 | has a C<&> pad slot pointing back to us. In this case, we set the | |
35 | C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what | |
36 | circumstances we should decrement the refcount of the parent when freeing | |
37 | the child. | |
38 | ||
28a5cf3b | 39 | There is a further complication with non-closure anonymous subs (i.e. those |
7dafbf52 DM |
40 | that do not refer to any lexicals outside that sub). In this case, the |
41 | anonymous prototype is shared rather than being cloned. This has the | |
42 | consequence that the parent may be freed while there are still active | |
43 | children, eg | |
44 | ||
45 | BEGIN { $a = sub { eval '$x' } } | |
46 | ||
47 | In this case, the BEGIN is freed immediately after execution since there | |
48 | are no active references to it: the anon sub prototype has | |
49 | C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same | |
50 | CV, so it doesn't contribute to BEGIN's refcount either. When $a is | |
51 | executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, | |
52 | and the freed BEGIN is accessed. | |
53 | ||
54 | To avoid this, whenever a CV and its associated pad is freed, any | |
55 | C<&> entries in the pad are explicitly removed from the pad, and if the | |
56 | refcount of the pointed-to anon sub is still positive, then that | |
57 | child's C<CvOUTSIDE> is set to point to its grandparent. This will only | |
58 | occur in the single specific case of a non-closure anon prototype | |
59 | having one or more active references (such as C<$a> above). | |
60 | ||
61 | One other thing to consider is that a CV may be merely undefined | |
62 | rather than freed, eg C<undef &foo>. In this case, its refcount may | |
63 | not have reached zero, but we still delete its pad and its C<CvROOT> etc. | |
64 | Since various children may still have their C<CvOUTSIDE> pointing at this | |
65 | undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that | |
66 | the chain of lexical scopes is unbroken. For example, the following | |
67 | should print 123: | |
68 | ||
69 | my $x = 123; | |
70 | sub tmp { sub { eval '$x' } } | |
71 | my $a = tmp(); | |
72 | undef &tmp; | |
73 | print $a->(); | |
74 | ||
75 | bool CvWEAKOUTSIDE(CV *cv) | |
76 | ||
77 | =for hackers | |
78 | Found in file cv.h | |
79 | ||
80 | ||
81 | =back | |
82 | ||
dd2155a4 DM |
83 | =head1 Functions in file pad.h |
84 | ||
85 | ||
86 | =over 8 | |
87 | ||
88 | =item CX_CURPAD_SAVE | |
d8c40edc | 89 | X<CX_CURPAD_SAVE> |
dd2155a4 DM |
90 | |
91 | Save the current pad in the given context block structure. | |
92 | ||
93 | void CX_CURPAD_SAVE(struct context) | |
94 | ||
95 | =for hackers | |
96 | Found in file pad.h | |
97 | ||
98 | =item CX_CURPAD_SV | |
d8c40edc | 99 | X<CX_CURPAD_SV> |
dd2155a4 DM |
100 | |
101 | Access the SV at offset po in the saved current pad in the given | |
102 | context block structure (can be used as an lvalue). | |
103 | ||
f3548bdc | 104 | SV * CX_CURPAD_SV(struct context, PADOFFSET po) |
dd2155a4 DM |
105 | |
106 | =for hackers | |
107 | Found in file pad.h | |
108 | ||
d8c40edc AT |
109 | =item PAD_BASE_SV |
110 | X<PAD_BASE_SV> | |
dd2155a4 DM |
111 | |
112 | Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist | |
113 | ||
d8c40edc | 114 | SV * PAD_BASE_SV(PADLIST padlist, PADOFFSET po) |
dd2155a4 DM |
115 | |
116 | =for hackers | |
117 | Found in file pad.h | |
118 | ||
119 | =item PAD_CLONE_VARS | |
d8c40edc | 120 | X<PAD_CLONE_VARS> |
dd2155a4 DM |
121 | |
122 | |CLONE_PARAMS* param | |
123 | Clone the state variables associated with running and compiling pads. | |
124 | ||
125 | void PAD_CLONE_VARS(PerlInterpreter *proto_perl \) | |
126 | ||
127 | =for hackers | |
128 | Found in file pad.h | |
129 | ||
130 | =item PAD_COMPNAME_FLAGS | |
d8c40edc | 131 | X<PAD_COMPNAME_FLAGS> |
dd2155a4 DM |
132 | |
133 | Return the flags for the current compiling pad name | |
134 | at offset C<po>. Assumes a valid slot entry. | |
135 | ||
136 | U32 PAD_COMPNAME_FLAGS(PADOFFSET po) | |
137 | ||
138 | =for hackers | |
139 | Found in file pad.h | |
140 | ||
141 | =item PAD_COMPNAME_GEN | |
d8c40edc | 142 | X<PAD_COMPNAME_GEN> |
dd2155a4 DM |
143 | |
144 | The generation number of the name at offset C<po> in the current | |
00a0d662 | 145 | compiling pad (lvalue). Note that C<SvUVX> is hijacked for this purpose. |
dd2155a4 DM |
146 | |
147 | STRLEN PAD_COMPNAME_GEN(PADOFFSET po) | |
148 | ||
149 | =for hackers | |
150 | Found in file pad.h | |
151 | ||
27da23d5 | 152 | =item PAD_COMPNAME_GEN_set |
d8c40edc | 153 | X<PAD_COMPNAME_GEN_set> |
27da23d5 JH |
154 | |
155 | Sets the generation number of the name at offset C<po> in the current | |
00a0d662 | 156 | ling pad (lvalue) to C<gen>. Note that C<SvUV_set> is hijacked for this purpose. |
27da23d5 JH |
157 | |
158 | STRLEN PAD_COMPNAME_GEN_set(PADOFFSET po, int gen) | |
159 | ||
160 | =for hackers | |
161 | Found in file pad.h | |
162 | ||
dd2155a4 | 163 | =item PAD_COMPNAME_OURSTASH |
d8c40edc | 164 | X<PAD_COMPNAME_OURSTASH> |
dd2155a4 DM |
165 | |
166 | Return the stash associated with an C<our> variable. | |
167 | Assumes the slot entry is a valid C<our> lexical. | |
168 | ||
169 | HV * PAD_COMPNAME_OURSTASH(PADOFFSET po) | |
170 | ||
171 | =for hackers | |
172 | Found in file pad.h | |
173 | ||
174 | =item PAD_COMPNAME_PV | |
d8c40edc | 175 | X<PAD_COMPNAME_PV> |
dd2155a4 DM |
176 | |
177 | Return the name of the current compiling pad name | |
178 | at offset C<po>. Assumes a valid slot entry. | |
179 | ||
180 | char * PAD_COMPNAME_PV(PADOFFSET po) | |
181 | ||
182 | =for hackers | |
183 | Found in file pad.h | |
184 | ||
185 | =item PAD_COMPNAME_TYPE | |
d8c40edc | 186 | X<PAD_COMPNAME_TYPE> |
dd2155a4 DM |
187 | |
188 | Return the type (stash) of the current compiling pad name at offset | |
189 | C<po>. Must be a valid name. Returns null if not typed. | |
190 | ||
191 | HV * PAD_COMPNAME_TYPE(PADOFFSET po) | |
192 | ||
193 | =for hackers | |
194 | Found in file pad.h | |
195 | ||
196 | =item PAD_DUP | |
d8c40edc | 197 | X<PAD_DUP> |
dd2155a4 DM |
198 | |
199 | Clone a padlist. | |
200 | ||
201 | void PAD_DUP(PADLIST dstpad, PADLIST srcpad, CLONE_PARAMS* param) | |
202 | ||
203 | =for hackers | |
204 | Found in file pad.h | |
205 | ||
f3548bdc | 206 | =item PAD_RESTORE_LOCAL |
d8c40edc | 207 | X<PAD_RESTORE_LOCAL> |
f3548bdc DM |
208 | |
209 | Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL() | |
210 | ||
211 | void PAD_RESTORE_LOCAL(PAD *opad) | |
212 | ||
213 | =for hackers | |
214 | Found in file pad.h | |
215 | ||
216 | =item PAD_SAVE_LOCAL | |
d8c40edc | 217 | X<PAD_SAVE_LOCAL> |
f3548bdc DM |
218 | |
219 | Save the current pad to the local variable opad, then make the | |
220 | current pad equal to npad | |
221 | ||
222 | void PAD_SAVE_LOCAL(PAD *opad, PAD *npad) | |
223 | ||
224 | =for hackers | |
225 | Found in file pad.h | |
226 | ||
dd2155a4 | 227 | =item PAD_SAVE_SETNULLPAD |
d8c40edc | 228 | X<PAD_SAVE_SETNULLPAD> |
dd2155a4 DM |
229 | |
230 | Save the current pad then set it to null. | |
231 | ||
232 | void PAD_SAVE_SETNULLPAD() | |
233 | ||
234 | =for hackers | |
235 | Found in file pad.h | |
236 | ||
d8c40edc AT |
237 | =item PAD_SETSV |
238 | X<PAD_SETSV> | |
dd2155a4 DM |
239 | |
240 | Set the slot at offset C<po> in the current pad to C<sv> | |
241 | ||
d8c40edc | 242 | SV * PAD_SETSV(PADOFFSET po, SV* sv) |
dd2155a4 DM |
243 | |
244 | =for hackers | |
245 | Found in file pad.h | |
246 | ||
d8c40edc AT |
247 | =item PAD_SET_CUR |
248 | X<PAD_SET_CUR> | |
dd2155a4 DM |
249 | |
250 | Set the current pad to be pad C<n> in the padlist, saving | |
f54ba1c2 DM |
251 | the previous current pad. NB currently this macro expands to a string too |
252 | long for some compilers, so it's best to replace it with | |
253 | ||
254 | SAVECOMPPAD(); | |
255 | PAD_SET_CUR_NOSAVE(padlist,n); | |
256 | ||
dd2155a4 | 257 | |
d8c40edc | 258 | void PAD_SET_CUR(PADLIST padlist, I32 n) |
dd2155a4 DM |
259 | |
260 | =for hackers | |
261 | Found in file pad.h | |
262 | ||
d8c40edc AT |
263 | =item PAD_SET_CUR_NOSAVE |
264 | X<PAD_SET_CUR_NOSAVE> | |
bf9cdc68 RG |
265 | |
266 | like PAD_SET_CUR, but without the save | |
267 | ||
d8c40edc | 268 | void PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n) |
bf9cdc68 RG |
269 | |
270 | =for hackers | |
271 | Found in file pad.h | |
272 | ||
d8c40edc AT |
273 | =item PAD_SV |
274 | X<PAD_SV> | |
dd2155a4 DM |
275 | |
276 | Get the value at offset C<po> in the current pad | |
277 | ||
d8c40edc | 278 | void PAD_SV(PADOFFSET po) |
dd2155a4 DM |
279 | |
280 | =for hackers | |
281 | Found in file pad.h | |
282 | ||
d8c40edc AT |
283 | =item PAD_SVl |
284 | X<PAD_SVl> | |
dd2155a4 DM |
285 | |
286 | Lightweight and lvalue version of C<PAD_SV>. | |
287 | Get or set the value at offset C<po> in the current pad. | |
288 | Unlike C<PAD_SV>, does not print diagnostics with -DX. | |
289 | For internal use only. | |
290 | ||
d8c40edc | 291 | SV * PAD_SVl(PADOFFSET po) |
dd2155a4 DM |
292 | |
293 | =for hackers | |
294 | Found in file pad.h | |
295 | ||
d8c40edc AT |
296 | =item SAVECLEARSV |
297 | X<SAVECLEARSV> | |
dd2155a4 | 298 | |
28a5cf3b | 299 | Clear the pointed to pad value on scope exit. (i.e. the runtime action of 'my') |
dd2155a4 | 300 | |
d8c40edc | 301 | void SAVECLEARSV(SV **svp) |
dd2155a4 DM |
302 | |
303 | =for hackers | |
304 | Found in file pad.h | |
305 | ||
306 | =item SAVECOMPPAD | |
d8c40edc | 307 | X<SAVECOMPPAD> |
dd2155a4 DM |
308 | |
309 | save PL_comppad and PL_curpad | |
310 | ||
dd2155a4 | 311 | |
dd2155a4 DM |
312 | |
313 | ||
314 | ||
f3548bdc | 315 | void SAVECOMPPAD() |
dd2155a4 DM |
316 | |
317 | =for hackers | |
318 | Found in file pad.h | |
319 | ||
d8c40edc AT |
320 | =item SAVEPADSV |
321 | X<SAVEPADSV> | |
dd2155a4 DM |
322 | |
323 | Save a pad slot (used to restore after an iteration) | |
324 | ||
f3548bdc | 325 | XXX DAPM it would make more sense to make the arg a PADOFFSET |
d8c40edc | 326 | void SAVEPADSV(PADOFFSET po) |
dd2155a4 DM |
327 | |
328 | =for hackers | |
329 | Found in file pad.h | |
330 | ||
331 | ||
332 | =back | |
333 | ||
a3985cdc DM |
334 | =head1 Functions in file pp_ctl.c |
335 | ||
336 | ||
337 | =over 8 | |
338 | ||
339 | =item find_runcv | |
d8c40edc | 340 | X<find_runcv> |
a3985cdc DM |
341 | |
342 | Locate the CV corresponding to the currently executing sub or eval. | |
d819b83a DM |
343 | If db_seqp is non_null, skip CVs that are in the DB package and populate |
344 | *db_seqp with the cop sequence number at the point that the DB:: code was | |
345 | entered. (allows debuggers to eval in the scope of the breakpoint rather | |
324092c6 | 346 | than in the scope of the debugger itself). |
a3985cdc | 347 | |
d819b83a | 348 | CV* find_runcv(U32 *db_seqp) |
a3985cdc DM |
349 | |
350 | =for hackers | |
351 | Found in file pp_ctl.c | |
352 | ||
353 | ||
354 | =back | |
355 | ||
a4f1a029 | 356 | =head1 Global Variables |
78f9721b | 357 | |
a4f1a029 | 358 | =over 8 |
78f9721b | 359 | |
2eb25c99 | 360 | =item PL_DBsingle |
d8c40edc | 361 | X<PL_DBsingle> |
2eb25c99 JH |
362 | |
363 | When Perl is run in debugging mode, with the B<-d> switch, this SV is a | |
364 | boolean which indicates whether subs are being single-stepped. | |
365 | Single-stepping is automatically turned on after every step. This is the C | |
366 | variable which corresponds to Perl's $DB::single variable. See | |
367 | C<PL_DBsub>. | |
368 | ||
369 | SV * PL_DBsingle | |
370 | ||
371 | =for hackers | |
372 | Found in file intrpvar.h | |
373 | ||
374 | =item PL_DBsub | |
d8c40edc | 375 | X<PL_DBsub> |
2eb25c99 JH |
376 | |
377 | When Perl is run in debugging mode, with the B<-d> switch, this GV contains | |
378 | the SV which holds the name of the sub being debugged. This is the C | |
379 | variable which corresponds to Perl's $DB::sub variable. See | |
380 | C<PL_DBsingle>. | |
381 | ||
382 | GV * PL_DBsub | |
383 | ||
384 | =for hackers | |
385 | Found in file intrpvar.h | |
386 | ||
387 | =item PL_DBtrace | |
d8c40edc | 388 | X<PL_DBtrace> |
2eb25c99 JH |
389 | |
390 | Trace variable used when Perl is run in debugging mode, with the B<-d> | |
391 | switch. This is the C variable which corresponds to Perl's $DB::trace | |
392 | variable. See C<PL_DBsingle>. | |
393 | ||
394 | SV * PL_DBtrace | |
395 | ||
396 | =for hackers | |
397 | Found in file intrpvar.h | |
398 | ||
399 | =item PL_dowarn | |
d8c40edc | 400 | X<PL_dowarn> |
2eb25c99 JH |
401 | |
402 | The C variable which corresponds to Perl's $^W warning variable. | |
403 | ||
404 | bool PL_dowarn | |
405 | ||
406 | =for hackers | |
407 | Found in file intrpvar.h | |
408 | ||
409 | =item PL_last_in_gv | |
d8c40edc | 410 | X<PL_last_in_gv> |
2eb25c99 JH |
411 | |
412 | The GV which was last used for a filehandle input operation. (C<< <FH> >>) | |
413 | ||
414 | GV* PL_last_in_gv | |
415 | ||
416 | =for hackers | |
417 | Found in file thrdvar.h | |
418 | ||
419 | =item PL_ofs_sv | |
d8c40edc | 420 | X<PL_ofs_sv> |
2eb25c99 JH |
421 | |
422 | The output field separator - C<$,> in Perl space. | |
423 | ||
424 | SV* PL_ofs_sv | |
425 | ||
426 | =for hackers | |
427 | Found in file thrdvar.h | |
428 | ||
429 | =item PL_rs | |
d8c40edc | 430 | X<PL_rs> |
2eb25c99 JH |
431 | |
432 | The input record separator - C<$/> in Perl space. | |
433 | ||
434 | SV* PL_rs | |
435 | ||
436 | =for hackers | |
437 | Found in file thrdvar.h | |
438 | ||
645c22ef | 439 | |
a4f1a029 | 440 | =back |
645c22ef | 441 | |
a4f1a029 NIS |
442 | =head1 GV Functions |
443 | ||
444 | =over 8 | |
445 | ||
446 | =item is_gv_magical | |
d8c40edc | 447 | X<is_gv_magical> |
a4f1a029 NIS |
448 | |
449 | Returns C<TRUE> if given the name of a magical GV. | |
450 | ||
451 | Currently only useful internally when determining if a GV should be | |
452 | created even in rvalue contexts. | |
453 | ||
454 | C<flags> is not used at present but available for future extension to | |
455 | allow selecting particular classes of magical variable. | |
456 | ||
766f8916 MHM |
457 | Currently assumes that C<name> is NUL terminated (as well as len being valid). |
458 | This assumption is met by all callers within the perl core, which all pass | |
459 | pointers returned by SvPV. | |
460 | ||
7fc63493 AL |
461 | bool is_gv_magical(const char *name, STRLEN len, U32 flags) |
462 | ||
463 | =for hackers | |
464 | Found in file gv.c | |
465 | ||
466 | =item is_gv_magical_sv | |
d8c40edc | 467 | X<is_gv_magical_sv> |
7fc63493 AL |
468 | |
469 | Returns C<TRUE> if given the name of a magical GV. Calls is_gv_magical. | |
470 | ||
471 | bool is_gv_magical_sv(SV *name, U32 flags) | |
645c22ef DM |
472 | |
473 | =for hackers | |
a4f1a029 NIS |
474 | Found in file gv.c |
475 | ||
476 | ||
477 | =back | |
478 | ||
b3ca2e83 NC |
479 | =head1 Hash Manipulation Functions |
480 | ||
481 | =over 8 | |
482 | ||
bd95ae50 SH |
483 | =item refcounted_he_chain_2hv |
484 | X<refcounted_he_chain_2hv> | |
485 | ||
486 | Generates an returns a C<HV *> by walking up the tree starting at the passed | |
487 | in C<struct refcounted_he *>. | |
488 | ||
489 | HV * refcounted_he_chain_2hv(const struct refcounted_he *c) | |
490 | ||
491 | =for hackers | |
492 | Found in file hv.c | |
493 | ||
b3ca2e83 NC |
494 | =item refcounted_he_free |
495 | X<refcounted_he_free> | |
496 | ||
497 | Decrements the reference count of the passed in C<struct refcounted_he *> | |
498 | by one. If the reference count reaches zero the structure's memory is freed, | |
499 | and C<refcounted_he_free> iterates onto the parent node. | |
500 | ||
501 | void refcounted_he_free(struct refcounted_he *he) | |
502 | ||
503 | =for hackers | |
504 | Found in file hv.c | |
505 | ||
506 | =item refcounted_he_new | |
507 | X<refcounted_he_new> | |
508 | ||
ec2a1de7 NC |
509 | Creates a new C<struct refcounted_he>. As S<key> is copied, and value is |
510 | stored in a compact form, all references remain the property of the caller. | |
511 | The C<struct refcounted_he> is returned with a reference count of 1. | |
b3ca2e83 | 512 | |
b46c265e | 513 | struct refcounted_he * refcounted_he_new(struct refcounted_he *const parent, SV *const key, SV *const value) |
b3ca2e83 NC |
514 | |
515 | =for hackers | |
516 | Found in file hv.c | |
517 | ||
518 | ||
519 | =back | |
520 | ||
a4f1a029 NIS |
521 | =head1 IO Functions |
522 | ||
523 | =over 8 | |
645c22ef | 524 | |
a8586c98 | 525 | =item start_glob |
d8c40edc | 526 | X<start_glob> |
a8586c98 JH |
527 | |
528 | Function called by C<do_readline> to spawn a glob (or do the glob inside | |
529 | perl on VMS). This code used to be inline, but now perl uses C<File::Glob> | |
bd16a5f0 | 530 | this glob starter is only used by miniperl during the build process. |
a8586c98 JH |
531 | Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up. |
532 | ||
533 | PerlIO* start_glob(SV* pattern, IO *io) | |
534 | ||
535 | =for hackers | |
536 | Found in file doio.c | |
537 | ||
a4f1a029 NIS |
538 | |
539 | =back | |
540 | ||
0cbee0a4 DM |
541 | =head1 Magical Functions |
542 | ||
543 | =over 8 | |
544 | ||
b3ca2e83 NC |
545 | =item magic_sethint |
546 | X<magic_sethint> | |
547 | ||
c28fe1ec NC |
548 | Triggered by a delete from %^H, records the key to |
549 | C<PL_compiling.cop_hints_hash>. | |
b3ca2e83 NC |
550 | |
551 | int magic_sethint(SV* sv, MAGIC* mg) | |
552 | ||
553 | =for hackers | |
554 | Found in file mg.c | |
555 | ||
0cbee0a4 | 556 | =item mg_localize |
d8c40edc | 557 | X<mg_localize> |
0cbee0a4 DM |
558 | |
559 | Copy some of the magic from an existing SV to new localized version of | |
560 | that SV. Container magic (eg %ENV, $1, tie) gets copied, value magic | |
561 | doesn't (eg taint, pos). | |
562 | ||
563 | void mg_localize(SV* sv, SV* nsv) | |
564 | ||
565 | =for hackers | |
566 | Found in file mg.c | |
567 | ||
568 | ||
569 | =back | |
570 | ||
a4f1a029 NIS |
571 | =head1 Pad Data Structures |
572 | ||
573 | =over 8 | |
574 | ||
575 | =item CvPADLIST | |
d8c40edc | 576 | X<CvPADLIST> |
a4f1a029 NIS |
577 | |
578 | CV's can have CvPADLIST(cv) set to point to an AV. | |
579 | ||
580 | For these purposes "forms" are a kind-of CV, eval""s are too (except they're | |
581 | not callable at will and are always thrown away after the eval"" is done | |
b5c19bd7 DM |
582 | executing). Require'd files are simply evals without any outer lexical |
583 | scope. | |
a4f1a029 NIS |
584 | |
585 | XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad, | |
586 | but that is really the callers pad (a slot of which is allocated by | |
587 | every entersub). | |
588 | ||
589 | The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items | |
f3548bdc | 590 | is managed "manual" (mostly in pad.c) rather than normal av.c rules. |
a4f1a029 NIS |
591 | The items in the AV are not SVs as for a normal AV, but other AVs: |
592 | ||
593 | 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather | |
594 | the "static type information" for lexicals. | |
595 | ||
596 | The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that | |
597 | depth of recursion into the CV. | |
598 | The 0'th slot of a frame AV is an AV which is @_. | |
599 | other entries are storage for variables and op targets. | |
600 | ||
601 | During compilation: | |
a6d05634 TM |
602 | C<PL_comppad_name> is set to the names AV. |
603 | C<PL_comppad> is set to the frame AV for the frame CvDEPTH == 1. | |
604 | C<PL_curpad> is set to the body of the frame AV (i.e. AvARRAY(PL_comppad)). | |
a4f1a029 | 605 | |
f3548bdc DM |
606 | During execution, C<PL_comppad> and C<PL_curpad> refer to the live |
607 | frame of the currently executing sub. | |
608 | ||
609 | Iterating over the names AV iterates over all possible pad | |
a4f1a029 NIS |
610 | items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having |
611 | &PL_sv_undef "names" (see pad_alloc()). | |
612 | ||
613 | Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names. | |
614 | The rest are op targets/GVs/constants which are statically allocated | |
615 | or resolved at compile time. These don't have names by which they | |
616 | can be looked up from Perl code at run time through eval"" like | |
617 | my/our variables can be. Since they can't be looked up by "name" | |
618 | but only by their index allocated at compile time (which is usually | |
619 | in PL_op->op_targ), wasting a name SV for them doesn't make sense. | |
620 | ||
621 | The SVs in the names AV have their PV being the name of the variable. | |
00a0d662 NC |
622 | xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for |
623 | which the name is valid. For typed lexicals name SV is SVt_PVMG and SvSTASH | |
624 | points at the type. For C<our> lexicals, the type is also SVt_PVMG, with the | |
44a2ac75 | 625 | SvOURSTASH slot pointing at the stash of the associated global (so that |
00a0d662 NC |
626 | duplicate C<our> declarations in the same package can be detected). SvUVX is |
627 | sometimes hijacked to store the generation number during compilation. | |
a4f1a029 | 628 | |
b5c19bd7 DM |
629 | If SvFAKE is set on the name SV, then that slot in the frame AV is |
630 | a REFCNT'ed reference to a lexical from "outside". In this case, | |
00a0d662 NC |
631 | the name SV does not use xlow and xhigh to store a cop_seq range, since it is |
632 | in scope throughout. Instead xhigh stores some flags containing info about | |
b5c19bd7 | 633 | the real lexical (is it declared in an anon, and is it capable of being |
00a0d662 | 634 | instantiated multiple times?), and for fake ANONs, xlow contains the index |
b5c19bd7 DM |
635 | within the parent's pad where the lexical's value is stored, to make |
636 | cloning quicker. | |
a4f1a029 | 637 | |
a6d05634 | 638 | If the 'name' is '&' the corresponding entry in frame AV |
a4f1a029 NIS |
639 | is a CV representing a possible closure. |
640 | (SvFAKE and name of '&' is not a meaningful combination currently but could | |
641 | become so if C<my sub foo {}> is implemented.) | |
642 | ||
5c3943b6 RGS |
643 | Note that formats are treated as anon subs, and are cloned each time |
644 | write is called (if necessary). | |
645 | ||
2814eb74 PJ |
646 | The flag SVf_PADSTALE is cleared on lexicals each time the my() is executed, |
647 | and set on scope exit. This allows the 'Variable $x is not available' warning | |
648 | to be generated in evals, such as | |
649 | ||
650 | { my $x = 1; sub f { eval '$x'} } f(); | |
651 | ||
a4f1a029 NIS |
652 | AV * CvPADLIST(CV *cv) |
653 | ||
654 | =for hackers | |
dd2155a4 DM |
655 | Found in file pad.c |
656 | ||
657 | =item cv_clone | |
d8c40edc | 658 | X<cv_clone> |
dd2155a4 DM |
659 | |
660 | Clone a CV: make a new CV which points to the same code etc, but which | |
ad63d80f | 661 | has a newly-created pad built by copying the prototype pad and capturing |
dd2155a4 DM |
662 | any outer lexicals. |
663 | ||
664 | CV* cv_clone(CV* proto) | |
665 | ||
666 | =for hackers | |
667 | Found in file pad.c | |
668 | ||
669 | =item cv_dump | |
d8c40edc | 670 | X<cv_dump> |
dd2155a4 DM |
671 | |
672 | dump the contents of a CV | |
673 | ||
e1ec3a88 | 674 | void cv_dump(const CV *cv, const char *title) |
dd2155a4 DM |
675 | |
676 | =for hackers | |
677 | Found in file pad.c | |
678 | ||
679 | =item do_dump_pad | |
d8c40edc | 680 | X<do_dump_pad> |
dd2155a4 DM |
681 | |
682 | Dump the contents of a padlist | |
683 | ||
684 | void do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full) | |
685 | ||
686 | =for hackers | |
687 | Found in file pad.c | |
688 | ||
689 | =item intro_my | |
d8c40edc | 690 | X<intro_my> |
dd2155a4 DM |
691 | |
692 | "Introduce" my variables to visible status. | |
693 | ||
694 | U32 intro_my() | |
695 | ||
696 | =for hackers | |
697 | Found in file pad.c | |
698 | ||
699 | =item pad_add_anon | |
d8c40edc | 700 | X<pad_add_anon> |
dd2155a4 DM |
701 | |
702 | Add an anon code entry to the current compiling pad | |
703 | ||
704 | PADOFFSET pad_add_anon(SV* sv, OPCODE op_type) | |
705 | ||
706 | =for hackers | |
707 | Found in file pad.c | |
708 | ||
709 | =item pad_add_name | |
d8c40edc | 710 | X<pad_add_name> |
dd2155a4 | 711 | |
b5c19bd7 DM |
712 | Create a new name and associated PADMY SV in the current pad; return the |
713 | offset. | |
dd2155a4 DM |
714 | If C<typestash> is valid, the name is for a typed lexical; set the |
715 | name's stash to that value. | |
716 | If C<ourstash> is valid, it's an our lexical, set the name's | |
44a2ac75 | 717 | SvOURSTASH to that value |
dd2155a4 | 718 | |
dd2155a4 DM |
719 | If fake, it means we're cloning an existing entry |
720 | ||
952306ac | 721 | PADOFFSET pad_add_name(const char *name, HV* typestash, HV* ourstash, bool clone, bool state) |
dd2155a4 DM |
722 | |
723 | =for hackers | |
724 | Found in file pad.c | |
725 | ||
726 | =item pad_alloc | |
d8c40edc | 727 | X<pad_alloc> |
dd2155a4 DM |
728 | |
729 | Allocate a new my or tmp pad entry. For a my, simply push a null SV onto | |
730 | the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards | |
324092c6 | 731 | for a slot which has no name and no active value. |
dd2155a4 DM |
732 | |
733 | PADOFFSET pad_alloc(I32 optype, U32 tmptype) | |
734 | ||
735 | =for hackers | |
736 | Found in file pad.c | |
737 | ||
738 | =item pad_block_start | |
d8c40edc | 739 | X<pad_block_start> |
dd2155a4 DM |
740 | |
741 | Update the pad compilation state variables on entry to a new block | |
742 | ||
743 | void pad_block_start(int full) | |
744 | ||
745 | =for hackers | |
746 | Found in file pad.c | |
747 | ||
748 | =item pad_check_dup | |
d8c40edc | 749 | X<pad_check_dup> |
dd2155a4 DM |
750 | |
751 | Check for duplicate declarations: report any of: | |
752 | * a my in the current scope with the same name; | |
753 | * an our (anywhere in the pad) with the same name and the same stash | |
754 | as C<ourstash> | |
755 | C<is_our> indicates that the name to check is an 'our' declaration | |
756 | ||
e1ec3a88 | 757 | void pad_check_dup(const char* name, bool is_our, const HV* ourstash) |
dd2155a4 DM |
758 | |
759 | =for hackers | |
760 | Found in file pad.c | |
761 | ||
762 | =item pad_findlex | |
d8c40edc | 763 | X<pad_findlex> |
dd2155a4 DM |
764 | |
765 | Find a named lexical anywhere in a chain of nested pads. Add fake entries | |
b5c19bd7 DM |
766 | in the inner pads if it's found in an outer one. |
767 | ||
768 | Returns the offset in the bottom pad of the lex or the fake lex. | |
769 | cv is the CV in which to start the search, and seq is the current cop_seq | |
770 | to match against. If warn is true, print appropriate warnings. The out_* | |
771 | vars return values, and so are pointers to where the returned values | |
772 | should be stored. out_capture, if non-null, requests that the innermost | |
773 | instance of the lexical is captured; out_name_sv is set to the innermost | |
774 | matched namesv or fake namesv; out_flags returns the flags normally | |
775 | associated with the IVX field of a fake namesv. | |
776 | ||
777 | Note that pad_findlex() is recursive; it recurses up the chain of CVs, | |
778 | then comes back down, adding fake entries as it goes. It has to be this way | |
00a0d662 | 779 | because fake namesvs in anon protoypes have to store in xlow the index into |
b5c19bd7 DM |
780 | the parent pad. |
781 | ||
e1ec3a88 | 782 | PADOFFSET pad_findlex(const char *name, const CV* cv, U32 seq, int warn, SV** out_capture, SV** out_name_sv, int *out_flags) |
dd2155a4 DM |
783 | |
784 | =for hackers | |
785 | Found in file pad.c | |
786 | ||
787 | =item pad_findmy | |
d8c40edc | 788 | X<pad_findmy> |
dd2155a4 | 789 | |
ad63d80f | 790 | Given a lexical name, try to find its offset, first in the current pad, |
dd2155a4 | 791 | or failing that, in the pads of any lexically enclosing subs (including |
ad63d80f JP |
792 | the complications introduced by eval). If the name is found in an outer pad, |
793 | then a fake entry is added to the current pad. | |
dd2155a4 DM |
794 | Returns the offset in the current pad, or NOT_IN_PAD on failure. |
795 | ||
e1ec3a88 | 796 | PADOFFSET pad_findmy(const char* name) |
dd2155a4 DM |
797 | |
798 | =for hackers | |
799 | Found in file pad.c | |
800 | ||
801 | =item pad_fixup_inner_anons | |
d8c40edc | 802 | X<pad_fixup_inner_anons> |
dd2155a4 DM |
803 | |
804 | For any anon CVs in the pad, change CvOUTSIDE of that CV from | |
7dafbf52 DM |
805 | old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be |
806 | moved to a pre-existing CV struct. | |
dd2155a4 DM |
807 | |
808 | void pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv) | |
809 | ||
810 | =for hackers | |
811 | Found in file pad.c | |
812 | ||
813 | =item pad_free | |
d8c40edc | 814 | X<pad_free> |
dd2155a4 | 815 | |
d7f8936a | 816 | Free the SV at offset po in the current pad. |
dd2155a4 DM |
817 | |
818 | void pad_free(PADOFFSET po) | |
819 | ||
820 | =for hackers | |
821 | Found in file pad.c | |
822 | ||
823 | =item pad_leavemy | |
d8c40edc | 824 | X<pad_leavemy> |
dd2155a4 DM |
825 | |
826 | Cleanup at end of scope during compilation: set the max seq number for | |
827 | lexicals in this scope and warn of any lexicals that never got introduced. | |
828 | ||
829 | void pad_leavemy() | |
830 | ||
831 | =for hackers | |
832 | Found in file pad.c | |
833 | ||
834 | =item pad_new | |
d8c40edc | 835 | X<pad_new> |
dd2155a4 | 836 | |
ad63d80f | 837 | Create a new compiling padlist, saving and updating the various global |
dd2155a4 DM |
838 | vars at the same time as creating the pad itself. The following flags |
839 | can be OR'ed together: | |
840 | ||
841 | padnew_CLONE this pad is for a cloned CV | |
842 | padnew_SAVE save old globals | |
843 | padnew_SAVESUB also save extra stuff for start of sub | |
844 | ||
c7c737cb | 845 | PADLIST* pad_new(int flags) |
dd2155a4 DM |
846 | |
847 | =for hackers | |
848 | Found in file pad.c | |
849 | ||
850 | =item pad_push | |
d8c40edc | 851 | X<pad_push> |
dd2155a4 DM |
852 | |
853 | Push a new pad frame onto the padlist, unless there's already a pad at | |
26019298 AL |
854 | this depth, in which case don't bother creating a new one. Then give |
855 | the new pad an @_ in slot zero. | |
dd2155a4 | 856 | |
26019298 | 857 | void pad_push(PADLIST *padlist, int depth) |
dd2155a4 DM |
858 | |
859 | =for hackers | |
860 | Found in file pad.c | |
861 | ||
862 | =item pad_reset | |
d8c40edc | 863 | X<pad_reset> |
dd2155a4 DM |
864 | |
865 | Mark all the current temporaries for reuse | |
866 | ||
867 | void pad_reset() | |
868 | ||
869 | =for hackers | |
870 | Found in file pad.c | |
871 | ||
872 | =item pad_setsv | |
d8c40edc | 873 | X<pad_setsv> |
dd2155a4 DM |
874 | |
875 | Set the entry at offset po in the current pad to sv. | |
876 | Use the macro PAD_SETSV() rather than calling this function directly. | |
877 | ||
878 | void pad_setsv(PADOFFSET po, SV* sv) | |
879 | ||
880 | =for hackers | |
881 | Found in file pad.c | |
882 | ||
883 | =item pad_swipe | |
d8c40edc | 884 | X<pad_swipe> |
dd2155a4 DM |
885 | |
886 | Abandon the tmp in the current pad at offset po and replace with a | |
887 | new one. | |
888 | ||
889 | void pad_swipe(PADOFFSET po, bool refadjust) | |
890 | ||
891 | =for hackers | |
892 | Found in file pad.c | |
893 | ||
894 | =item pad_tidy | |
d8c40edc | 895 | X<pad_tidy> |
dd2155a4 DM |
896 | |
897 | Tidy up a pad after we've finished compiling it: | |
898 | * remove most stuff from the pads of anonsub prototypes; | |
899 | * give it a @_; | |
900 | * mark tmps as such. | |
901 | ||
902 | void pad_tidy(padtidy_type type) | |
903 | ||
904 | =for hackers | |
905 | Found in file pad.c | |
906 | ||
907 | =item pad_undef | |
d8c40edc | 908 | X<pad_undef> |
dd2155a4 DM |
909 | |
910 | Free the padlist associated with a CV. | |
911 | If parts of it happen to be current, we null the relevant | |
912 | PL_*pad* global vars so that we don't have any dangling references left. | |
913 | We also repoint the CvOUTSIDE of any about-to-be-orphaned | |
a3985cdc | 914 | inner subs to the outer of this cv. |
dd2155a4 | 915 | |
7dafbf52 DM |
916 | (This function should really be called pad_free, but the name was already |
917 | taken) | |
918 | ||
a3985cdc | 919 | void pad_undef(CV* cv) |
dd2155a4 DM |
920 | |
921 | =for hackers | |
922 | Found in file pad.c | |
a4f1a029 NIS |
923 | |
924 | ||
925 | =back | |
926 | ||
927 | =head1 Stack Manipulation Macros | |
928 | ||
929 | =over 8 | |
930 | ||
931 | =item djSP | |
d8c40edc | 932 | X<djSP> |
a4f1a029 NIS |
933 | |
934 | Declare Just C<SP>. This is actually identical to C<dSP>, and declares | |
935 | a local copy of perl's stack pointer, available via the C<SP> macro. | |
936 | See C<SP>. (Available for backward source code compatibility with the | |
937 | old (Perl 5.005) thread model.) | |
938 | ||
939 | djSP; | |
940 | ||
941 | =for hackers | |
942 | Found in file pp.h | |
943 | ||
944 | =item LVRET | |
d8c40edc | 945 | X<LVRET> |
a4f1a029 NIS |
946 | |
947 | True if this op will be the return value of an lvalue subroutine | |
948 | ||
949 | =for hackers | |
950 | Found in file pp.h | |
951 | ||
952 | ||
953 | =back | |
954 | ||
955 | =head1 SV Manipulation Functions | |
956 | ||
957 | =over 8 | |
958 | ||
645c22ef | 959 | =item sv_add_arena |
d8c40edc | 960 | X<sv_add_arena> |
645c22ef DM |
961 | |
962 | Given a chunk of memory, link it to the head of the list of arenas, | |
963 | and split it into a list of free SVs. | |
964 | ||
965 | void sv_add_arena(char* ptr, U32 size, U32 flags) | |
966 | ||
967 | =for hackers | |
968 | Found in file sv.c | |
969 | ||
970 | =item sv_clean_all | |
d8c40edc | 971 | X<sv_clean_all> |
645c22ef DM |
972 | |
973 | Decrement the refcnt of each remaining SV, possibly triggering a | |
974 | cleanup. This function may have to be called multiple times to free | |
8fb26106 | 975 | SVs which are in complex self-referential hierarchies. |
645c22ef DM |
976 | |
977 | I32 sv_clean_all() | |
978 | ||
979 | =for hackers | |
980 | Found in file sv.c | |
981 | ||
982 | =item sv_clean_objs | |
d8c40edc | 983 | X<sv_clean_objs> |
645c22ef DM |
984 | |
985 | Attempt to destroy all objects not yet freed | |
986 | ||
987 | void sv_clean_objs() | |
988 | ||
989 | =for hackers | |
990 | Found in file sv.c | |
991 | ||
992 | =item sv_free_arenas | |
d8c40edc | 993 | X<sv_free_arenas> |
645c22ef DM |
994 | |
995 | Deallocate the memory used by all arenas. Note that all the individual SV | |
996 | heads and bodies within the arenas must already have been freed. | |
997 | ||
998 | void sv_free_arenas() | |
999 | ||
1000 | =for hackers | |
1001 | Found in file sv.c | |
1002 | ||
a4f1a029 | 1003 | |
954c1994 GS |
1004 | =back |
1005 | ||
979f2922 TS |
1006 | =head1 Unicode Support |
1007 | ||
1008 | =over 8 | |
1009 | ||
1010 | =item find_uninit_var | |
1011 | X<find_uninit_var> | |
1012 | ||
1013 | Find the name of the undefined variable (if any) that caused the operator o | |
1014 | to issue a "Use of uninitialized value" warning. | |
1015 | If match is true, only return a name if it's value matches uninit_sv. | |
1016 | So roughly speaking, if a unary operator (such as OP_COS) generates a | |
1017 | warning, then following the direct child of the op may yield an | |
1018 | OP_PADSV or OP_GV that gives the name of the undefined variable. On the | |
1019 | other hand, with OP_ADD there are two branches to follow, so we only print | |
1020 | the variable name if we get an exact match. | |
1021 | ||
1022 | The name is returned as a mortal SV. | |
1023 | ||
1024 | Assumes that PL_op is the op that originally triggered the error, and that | |
1025 | PL_comppad/PL_curpad points to the currently executing pad. | |
1026 | ||
1027 | SV* find_uninit_var(OP* obase, SV* uninit_sv, bool top) | |
1028 | ||
1029 | =for hackers | |
1030 | Found in file sv.c | |
1031 | ||
1032 | =item report_uninit | |
1033 | X<report_uninit> | |
1034 | ||
1035 | Print appropriate "Use of uninitialized variable" warning | |
1036 | ||
1037 | void report_uninit(SV* uninit_sv) | |
1038 | ||
1039 | =for hackers | |
1040 | Found in file sv.c | |
1041 | ||
1042 | ||
1043 | =back | |
1044 | ||
954c1994 GS |
1045 | =head1 AUTHORS |
1046 | ||
1c846c1f NIS |
1047 | The autodocumentation system was originally added to the Perl core by |
1048 | Benjamin Stuhl. Documentation is by whoever was kind enough to | |
954c1994 GS |
1049 | document their functions. |
1050 | ||
1051 | =head1 SEE ALSO | |
1052 | ||
1053 | perlguts(1), perlapi(1) | |
1054 | ||
3f98fbb3 RGS |
1055 | =cut |
1056 | ||
1057 | ex: set ro: |