3 perlintern - autogenerated documentation of purely B<internal>
8 This file is the autogenerated documentation of functions in the
9 Perl interpreter that are documented using Perl's internal documentation
10 format but are not marked as part of the Perl API. In other words,
11 B<they are not for use in extensions>!
14 =head1 Functions in file pad.h
21 Save the current pad in the given context block structure.
23 void CX_CURPAD_SAVE(struct context)
30 Access the SV at offset po in the saved current pad in the given
31 context block structure (can be used as an lvalue).
33 SV * CX_CURPAD_SV(struct context, PADOFFSET po)
40 Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
42 SV * PAD_BASE_SV (PADLIST padlist, PADOFFSET po)
50 Clone the state variables associated with running and compiling pads.
52 void PAD_CLONE_VARS(PerlInterpreter *proto_perl \)
57 =item PAD_COMPNAME_FLAGS
59 Return the flags for the current compiling pad name
60 at offset C<po>. Assumes a valid slot entry.
62 U32 PAD_COMPNAME_FLAGS(PADOFFSET po)
67 =item PAD_COMPNAME_GEN
69 The generation number of the name at offset C<po> in the current
70 compiling pad (lvalue). Note that C<SvCUR> is hijacked for this purpose.
72 STRLEN PAD_COMPNAME_GEN(PADOFFSET po)
77 =item PAD_COMPNAME_OURSTASH
79 Return the stash associated with an C<our> variable.
80 Assumes the slot entry is a valid C<our> lexical.
82 HV * PAD_COMPNAME_OURSTASH(PADOFFSET po)
89 Return the name of the current compiling pad name
90 at offset C<po>. Assumes a valid slot entry.
92 char * PAD_COMPNAME_PV(PADOFFSET po)
97 =item PAD_COMPNAME_TYPE
99 Return the type (stash) of the current compiling pad name at offset
100 C<po>. Must be a valid name. Returns null if not typed.
102 HV * PAD_COMPNAME_TYPE(PADOFFSET po)
111 void PAD_DUP(PADLIST dstpad, PADLIST srcpad, CLONE_PARAMS* param)
116 =item PAD_RESTORE_LOCAL
118 Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()
120 void PAD_RESTORE_LOCAL(PAD *opad)
127 Save the current pad to the local variable opad, then make the
128 current pad equal to npad
130 void PAD_SAVE_LOCAL(PAD *opad, PAD *npad)
135 =item PAD_SAVE_SETNULLPAD
137 Save the current pad then set it to null.
139 void PAD_SAVE_SETNULLPAD()
146 Set the slot at offset C<po> in the current pad to C<sv>
148 SV * PAD_SETSV (PADOFFSET po, SV* sv)
155 Set the current pad to be pad C<n> in the padlist, saving
156 the previous current pad.
158 void PAD_SET_CUR (PADLIST padlist, I32 n)
165 Get the value at offset C<po> in the current pad
167 void PAD_SV (PADOFFSET po)
174 Lightweight and lvalue version of C<PAD_SV>.
175 Get or set the value at offset C<po> in the current pad.
176 Unlike C<PAD_SV>, does not print diagnostics with -DX.
177 For internal use only.
179 SV * PAD_SVl (PADOFFSET po)
186 Clear the pointed to pad value on scope exit. (ie the runtime action of 'my')
188 void SAVECLEARSV (SV **svp)
195 save PL_comppad and PL_curpad
208 Save a pad slot (used to restore after an iteration)
210 XXX DAPM it would make more sense to make the arg a PADOFFSET
211 void SAVEPADSV (PADOFFSET po)
219 =head1 Global Variables
225 When Perl is run in debugging mode, with the B<-d> switch, this SV is a
226 boolean which indicates whether subs are being single-stepped.
227 Single-stepping is automatically turned on after every step. This is the C
228 variable which corresponds to Perl's $DB::single variable. See
234 Found in file intrpvar.h
238 When Perl is run in debugging mode, with the B<-d> switch, this GV contains
239 the SV which holds the name of the sub being debugged. This is the C
240 variable which corresponds to Perl's $DB::sub variable. See
246 Found in file intrpvar.h
250 Trace variable used when Perl is run in debugging mode, with the B<-d>
251 switch. This is the C variable which corresponds to Perl's $DB::trace
252 variable. See C<PL_DBsingle>.
257 Found in file intrpvar.h
261 The C variable which corresponds to Perl's $^W warning variable.
266 Found in file intrpvar.h
270 The GV which was last used for a filehandle input operation. (C<< <FH> >>)
275 Found in file thrdvar.h
279 The output field separator - C<$,> in Perl space.
284 Found in file thrdvar.h
288 The input record separator - C<$/> in Perl space.
293 Found in file thrdvar.h
304 Returns C<TRUE> if given the name of a magical GV.
306 Currently only useful internally when determining if a GV should be
307 created even in rvalue contexts.
309 C<flags> is not used at present but available for future extension to
310 allow selecting particular classes of magical variable.
312 bool is_gv_magical(char *name, STRLEN len, U32 flags)
326 Function called by C<do_readline> to spawn a glob (or do the glob inside
327 perl on VMS). This code used to be inline, but now perl uses C<File::Glob>
328 this glob starter is only used by miniperl during the build process.
329 Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up.
331 PerlIO* start_glob(SV* pattern, IO *io)
339 =head1 Pad Data Structures
345 CV's can have CvPADLIST(cv) set to point to an AV.
347 For these purposes "forms" are a kind-of CV, eval""s are too (except they're
348 not callable at will and are always thrown away after the eval"" is done
351 XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad,
352 but that is really the callers pad (a slot of which is allocated by
355 The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items
356 is managed "manual" (mostly in pad.c) rather than normal av.c rules.
357 The items in the AV are not SVs as for a normal AV, but other AVs:
359 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather
360 the "static type information" for lexicals.
362 The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that
363 depth of recursion into the CV.
364 The 0'th slot of a frame AV is an AV which is @_.
365 other entries are storage for variables and op targets.
368 C<PL_comppad_name> is set the the the names AV.
369 C<PL_comppad> is set the the frame AV for the frame CvDEPTH == 1.
370 C<PL_curpad> is set the body of the frame AV (i.e. AvARRAY(PL_comppad)).
372 During execution, C<PL_comppad> and C<PL_curpad> refer to the live
373 frame of the currently executing sub.
375 Iterating over the names AV iterates over all possible pad
376 items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having
377 &PL_sv_undef "names" (see pad_alloc()).
379 Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names.
380 The rest are op targets/GVs/constants which are statically allocated
381 or resolved at compile time. These don't have names by which they
382 can be looked up from Perl code at run time through eval"" like
383 my/our variables can be. Since they can't be looked up by "name"
384 but only by their index allocated at compile time (which is usually
385 in PL_op->op_targ), wasting a name SV for them doesn't make sense.
387 The SVs in the names AV have their PV being the name of the variable.
388 NV+1..IV inclusive is a range of cop_seq numbers for which the name is
389 valid. For typed lexicals name SV is SVt_PVMG and SvSTASH points at the
390 type. For C<our> lexicals, the type is SVt_PVGV, and GvSTASH points at the
391 stash of the associated global (so that duplicate C<our> delarations in the
392 same package can be detected). SvCUR is sometimes hijacked to
393 store the generation number during compilation.
395 If SvFAKE is set on the name SV then slot in the frame AVs are
396 a REFCNT'ed references to a lexical from "outside".
398 If the 'name' is '&' the the corresponding entry in frame AV
399 is a CV representing a possible closure.
400 (SvFAKE and name of '&' is not a meaningful combination currently but could
401 become so if C<my sub foo {}> is implemented.)
403 AV * CvPADLIST(CV *cv)
410 Clone a CV: make a new CV which points to the same code etc, but which
411 has a newly-created pad built by copying the prototype pad and capturing
414 CV* cv_clone(CV* proto)
421 dump the contents of a CV
423 void cv_dump(CV *cv, char *title)
430 Dump the contents of a padlist
432 void do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full)
439 "Introduce" my variables to visible status.
448 Add an anon code entry to the current compiling pad
450 PADOFFSET pad_add_anon(SV* sv, OPCODE op_type)
457 Create a new name in the current pad at the specified offset.
458 If C<typestash> is valid, the name is for a typed lexical; set the
459 name's stash to that value.
460 If C<ourstash> is valid, it's an our lexical, set the name's
461 GvSTASH to that value
463 Also, if the name is @.. or %.., create a new array or hash for that slot
465 If fake, it means we're cloning an existing entry
467 PADOFFSET pad_add_name(char *name, HV* typestash, HV* ourstash, bool clone)
474 Allocate a new my or tmp pad entry. For a my, simply push a null SV onto
475 the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards
476 for a slot which has no name and and no active value.
478 PADOFFSET pad_alloc(I32 optype, U32 tmptype)
483 =item pad_block_start
485 Update the pad compilation state variables on entry to a new block
487 void pad_block_start(int full)
494 Check for duplicate declarations: report any of:
495 * a my in the current scope with the same name;
496 * an our (anywhere in the pad) with the same name and the same stash
498 C<is_our> indicates that the name to check is an 'our' declaration
500 void pad_check_dup(char* name, bool is_our, HV* ourstash)
507 Find a named lexical anywhere in a chain of nested pads. Add fake entries
508 in the inner pads if its found in an outer one.
510 If flags == FINDLEX_NOSEARCH we don't bother searching outer contexts.
512 PADOFFSET pad_findlex(char* name, PADOFFSET newoff, U32 seq, CV* startcv, I32 cx_ix, I32 saweval, U32 flags)
519 Given a lexical name, try to find its offset, first in the current pad,
520 or failing that, in the pads of any lexically enclosing subs (including
521 the complications introduced by eval). If the name is found in an outer pad,
522 then a fake entry is added to the current pad.
523 Returns the offset in the current pad, or NOT_IN_PAD on failure.
525 PADOFFSET pad_findmy(char* name)
530 =item pad_fixup_inner_anons
532 For any anon CVs in the pad, change CvOUTSIDE of that CV from
533 old_cv to new_cv if necessary.
535 void pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv)
542 Free the SV at offet po in the current pad.
544 void pad_free(PADOFFSET po)
551 Cleanup at end of scope during compilation: set the max seq number for
552 lexicals in this scope and warn of any lexicals that never got introduced.
561 Create a new compiling padlist, saving and updating the various global
562 vars at the same time as creating the pad itself. The following flags
563 can be OR'ed together:
565 padnew_CLONE this pad is for a cloned CV
566 padnew_SAVE save old globals
567 padnew_SAVESUB also save extra stuff for start of sub
569 PADLIST* pad_new(padnew_flags flags)
576 Push a new pad frame onto the padlist, unless there's already a pad at
577 this depth, in which case don't bother creating a new one.
578 If has_args is true, give the new pad an @_ in slot zero.
580 void pad_push(PADLIST *padlist, int depth, int has_args)
587 Mark all the current temporaries for reuse
596 Set the entry at offset po in the current pad to sv.
597 Use the macro PAD_SETSV() rather than calling this function directly.
599 void pad_setsv(PADOFFSET po, SV* sv)
606 Abandon the tmp in the current pad at offset po and replace with a
609 void pad_swipe(PADOFFSET po, bool refadjust)
616 Tidy up a pad after we've finished compiling it:
617 * remove most stuff from the pads of anonsub prototypes;
621 void pad_tidy(padtidy_type type)
628 Free the padlist associated with a CV.
629 If parts of it happen to be current, we null the relevant
630 PL_*pad* global vars so that we don't have any dangling references left.
631 We also repoint the CvOUTSIDE of any about-to-be-orphaned
632 inner subs to outercv.
634 void pad_undef(CV* cv, CV* outercv)
642 =head1 Stack Manipulation Macros
648 Declare Just C<SP>. This is actually identical to C<dSP>, and declares
649 a local copy of perl's stack pointer, available via the C<SP> macro.
650 See C<SP>. (Available for backward source code compatibility with the
651 old (Perl 5.005) thread model.)
660 True if this op will be the return value of an lvalue subroutine
668 =head1 SV Manipulation Functions
674 Print appropriate "Use of uninitialized variable" warning
683 Given a chunk of memory, link it to the head of the list of arenas,
684 and split it into a list of free SVs.
686 void sv_add_arena(char* ptr, U32 size, U32 flags)
693 Decrement the refcnt of each remaining SV, possibly triggering a
694 cleanup. This function may have to be called multiple times to free
695 SVs which are in complex self-referential hierarchies.
704 Attempt to destroy all objects not yet freed
713 Deallocate the memory used by all arenas. Note that all the individual SV
714 heads and bodies within the arenas must already have been freed.
716 void sv_free_arenas()
726 The autodocumentation system was originally added to the Perl core by
727 Benjamin Stuhl. Documentation is by whoever was kind enough to
728 document their functions.
732 perlguts(1), perlapi(1)