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 Functions in file pp_ctl.c
226 Locate the CV corresponding to the currently executing sub or eval.
231 Found in file pp_ctl.c
236 =head1 Global Variables
242 When Perl is run in debugging mode, with the B<-d> switch, this SV is a
243 boolean which indicates whether subs are being single-stepped.
244 Single-stepping is automatically turned on after every step. This is the C
245 variable which corresponds to Perl's $DB::single variable. See
251 Found in file intrpvar.h
255 When Perl is run in debugging mode, with the B<-d> switch, this GV contains
256 the SV which holds the name of the sub being debugged. This is the C
257 variable which corresponds to Perl's $DB::sub variable. See
263 Found in file intrpvar.h
267 Trace variable used when Perl is run in debugging mode, with the B<-d>
268 switch. This is the C variable which corresponds to Perl's $DB::trace
269 variable. See C<PL_DBsingle>.
274 Found in file intrpvar.h
278 The C variable which corresponds to Perl's $^W warning variable.
283 Found in file intrpvar.h
287 The GV which was last used for a filehandle input operation. (C<< <FH> >>)
292 Found in file thrdvar.h
296 The output field separator - C<$,> in Perl space.
301 Found in file thrdvar.h
305 The input record separator - C<$/> in Perl space.
310 Found in file thrdvar.h
321 Returns C<TRUE> if given the name of a magical GV.
323 Currently only useful internally when determining if a GV should be
324 created even in rvalue contexts.
326 C<flags> is not used at present but available for future extension to
327 allow selecting particular classes of magical variable.
329 bool is_gv_magical(char *name, STRLEN len, U32 flags)
343 Function called by C<do_readline> to spawn a glob (or do the glob inside
344 perl on VMS). This code used to be inline, but now perl uses C<File::Glob>
345 this glob starter is only used by miniperl during the build process.
346 Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up.
348 PerlIO* start_glob(SV* pattern, IO *io)
356 =head1 Pad Data Structures
362 CV's can have CvPADLIST(cv) set to point to an AV.
364 For these purposes "forms" are a kind-of CV, eval""s are too (except they're
365 not callable at will and are always thrown away after the eval"" is done
368 XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad,
369 but that is really the callers pad (a slot of which is allocated by
372 The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items
373 is managed "manual" (mostly in pad.c) rather than normal av.c rules.
374 The items in the AV are not SVs as for a normal AV, but other AVs:
376 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather
377 the "static type information" for lexicals.
379 The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that
380 depth of recursion into the CV.
381 The 0'th slot of a frame AV is an AV which is @_.
382 other entries are storage for variables and op targets.
385 C<PL_comppad_name> is set the the the names AV.
386 C<PL_comppad> is set the the frame AV for the frame CvDEPTH == 1.
387 C<PL_curpad> is set the body of the frame AV (i.e. AvARRAY(PL_comppad)).
389 During execution, C<PL_comppad> and C<PL_curpad> refer to the live
390 frame of the currently executing sub.
392 Iterating over the names AV iterates over all possible pad
393 items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having
394 &PL_sv_undef "names" (see pad_alloc()).
396 Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names.
397 The rest are op targets/GVs/constants which are statically allocated
398 or resolved at compile time. These don't have names by which they
399 can be looked up from Perl code at run time through eval"" like
400 my/our variables can be. Since they can't be looked up by "name"
401 but only by their index allocated at compile time (which is usually
402 in PL_op->op_targ), wasting a name SV for them doesn't make sense.
404 The SVs in the names AV have their PV being the name of the variable.
405 NV+1..IV inclusive is a range of cop_seq numbers for which the name is
406 valid. For typed lexicals name SV is SVt_PVMG and SvSTASH points at the
407 type. For C<our> lexicals, the type is SVt_PVGV, and GvSTASH points at the
408 stash of the associated global (so that duplicate C<our> delarations in the
409 same package can be detected). SvCUR is sometimes hijacked to
410 store the generation number during compilation.
412 If SvFAKE is set on the name SV then slot in the frame AVs are
413 a REFCNT'ed references to a lexical from "outside". In this case,
414 the name SV does not have a cop_seq range, since it is in scope
417 If the 'name' is '&' the the corresponding entry in frame AV
418 is a CV representing a possible closure.
419 (SvFAKE and name of '&' is not a meaningful combination currently but could
420 become so if C<my sub foo {}> is implemented.)
422 AV * CvPADLIST(CV *cv)
429 Clone a CV: make a new CV which points to the same code etc, but which
430 has a newly-created pad built by copying the prototype pad and capturing
433 CV* cv_clone(CV* proto)
440 dump the contents of a CV
442 void cv_dump(CV *cv, char *title)
449 Dump the contents of a padlist
451 void do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full)
458 "Introduce" my variables to visible status.
467 Add an anon code entry to the current compiling pad
469 PADOFFSET pad_add_anon(SV* sv, OPCODE op_type)
476 Create a new name in the current pad at the specified offset.
477 If C<typestash> is valid, the name is for a typed lexical; set the
478 name's stash to that value.
479 If C<ourstash> is valid, it's an our lexical, set the name's
480 GvSTASH to that value
482 Also, if the name is @.. or %.., create a new array or hash for that slot
484 If fake, it means we're cloning an existing entry
486 PADOFFSET pad_add_name(char *name, HV* typestash, HV* ourstash, bool clone)
493 Allocate a new my or tmp pad entry. For a my, simply push a null SV onto
494 the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards
495 for a slot which has no name and and no active value.
497 PADOFFSET pad_alloc(I32 optype, U32 tmptype)
502 =item pad_block_start
504 Update the pad compilation state variables on entry to a new block
506 void pad_block_start(int full)
513 Check for duplicate declarations: report any of:
514 * a my in the current scope with the same name;
515 * an our (anywhere in the pad) with the same name and the same stash
517 C<is_our> indicates that the name to check is an 'our' declaration
519 void pad_check_dup(char* name, bool is_our, HV* ourstash)
526 Find a named lexical anywhere in a chain of nested pads. Add fake entries
527 in the inner pads if it's found in an outer one. innercv is the CV *inside*
528 the chain of outer CVs to be searched. If newoff is non-null, this is a
529 run-time cloning: don't add fake entries, just find the lexical and add a
530 ref to it at newoff in the current pad.
532 PADOFFSET pad_findlex(char* name, PADOFFSET newoff, CV* innercv)
539 Given a lexical name, try to find its offset, first in the current pad,
540 or failing that, in the pads of any lexically enclosing subs (including
541 the complications introduced by eval). If the name is found in an outer pad,
542 then a fake entry is added to the current pad.
543 Returns the offset in the current pad, or NOT_IN_PAD on failure.
545 PADOFFSET pad_findmy(char* name)
550 =item pad_fixup_inner_anons
552 For any anon CVs in the pad, change CvOUTSIDE of that CV from
553 old_cv to new_cv if necessary.
555 void pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv)
562 Free the SV at offet po in the current pad.
564 void pad_free(PADOFFSET po)
571 Cleanup at end of scope during compilation: set the max seq number for
572 lexicals in this scope and warn of any lexicals that never got introduced.
581 Create a new compiling padlist, saving and updating the various global
582 vars at the same time as creating the pad itself. The following flags
583 can be OR'ed together:
585 padnew_CLONE this pad is for a cloned CV
586 padnew_SAVE save old globals
587 padnew_SAVESUB also save extra stuff for start of sub
589 PADLIST* pad_new(padnew_flags flags)
596 Push a new pad frame onto the padlist, unless there's already a pad at
597 this depth, in which case don't bother creating a new one.
598 If has_args is true, give the new pad an @_ in slot zero.
600 void pad_push(PADLIST *padlist, int depth, int has_args)
607 Mark all the current temporaries for reuse
616 Set the entry at offset po in the current pad to sv.
617 Use the macro PAD_SETSV() rather than calling this function directly.
619 void pad_setsv(PADOFFSET po, SV* sv)
626 Abandon the tmp in the current pad at offset po and replace with a
629 void pad_swipe(PADOFFSET po, bool refadjust)
636 Tidy up a pad after we've finished compiling it:
637 * remove most stuff from the pads of anonsub prototypes;
641 void pad_tidy(padtidy_type type)
648 Free the padlist associated with a CV.
649 If parts of it happen to be current, we null the relevant
650 PL_*pad* global vars so that we don't have any dangling references left.
651 We also repoint the CvOUTSIDE of any about-to-be-orphaned
652 inner subs to the outer of this cv.
654 void pad_undef(CV* cv)
662 =head1 Stack Manipulation Macros
668 Declare Just C<SP>. This is actually identical to C<dSP>, and declares
669 a local copy of perl's stack pointer, available via the C<SP> macro.
670 See C<SP>. (Available for backward source code compatibility with the
671 old (Perl 5.005) thread model.)
680 True if this op will be the return value of an lvalue subroutine
688 =head1 SV Manipulation Functions
694 Print appropriate "Use of uninitialized variable" warning
703 Given a chunk of memory, link it to the head of the list of arenas,
704 and split it into a list of free SVs.
706 void sv_add_arena(char* ptr, U32 size, U32 flags)
713 Decrement the refcnt of each remaining SV, possibly triggering a
714 cleanup. This function may have to be called multiple times to free
715 SVs which are in complex self-referential hierarchies.
724 Attempt to destroy all objects not yet freed
733 Deallocate the memory used by all arenas. Note that all the individual SV
734 heads and bodies within the arenas must already have been freed.
736 void sv_free_arenas()
746 The autodocumentation system was originally added to the Perl core by
747 Benjamin Stuhl. Documentation is by whoever was kind enough to
748 document their functions.
752 perlguts(1), perlapi(1)