perlintern - autogenerated documentation of purelyinternal Perl functions
This file is the autogenerated documentation of functions in the Perl interpreter that are documented using Perl's internal documentation format but are not marked as part of the Perl API. In other words,they are not for use in extensions!
NOTE: this function is experimental and may change or be removed without notice.
Return an entry from the BHK structure.which is a preprocessor token indicating which entry to return. If the appropriate flag is not set this will returnNULL. The type of the return value depends on which entry you ask for.
void *BhkENTRY(BHK *hk, which)NOTE: this function is experimental and may change or be removed without notice.
Return the BHK's flags.
U32BhkFLAGS(BHK *hk)NOTE: this function is experimental and may change or be removed without notice.
Call all the registered block hooks for typewhich.which is a preprocessing token; the type ofarg depends onwhich.
voidCALL_BLOCK_HOOKS(which, arg)This function assigns the prototype of the named core function tosv, or to a new mortal SV ifsv isNULL. It returns the modifiedsv, orNULL if the core function has no prototype.code is a code as returned bykeyword(). It must not be equal to 0.
SV *core_prototype(SV *sv, const char *name, const int code, int * const opnum)Check for the cases 0 or 3 of cur_env.je_ret, only used inside an eval context.
0 is used as continue inside eval,
3 is used for a die caught by an inner eval - continue inner loop
Seecop.h: je_mustcatch, when set at any runlevel to TRUE, means eval ops must establish a local jmpenv to handle exception traps.
OP*docatch(OP *o)Each CV has a pointer,CvOUTSIDE(), to its lexically enclosing CV (if any). Because pointers to anonymous sub prototypes are stored in& pad slots, it is a possible to get a circular reference, with the parent pointing to the child and vice-versa. To avoid the ensuing memory leak, we do not increment the reference count of the CV pointed to byCvOUTSIDE in theone specific instance that the parent has a& pad slot pointing back to us. In this case, we set theCvWEAKOUTSIDE flag in the child. This allows us to determine under what circumstances we should decrement the refcount of the parent when freeing the child.
There is a further complication with non-closure anonymous subs (i.e. those that do not refer to any lexicals outside that sub). In this case, the anonymous prototype is shared rather than being cloned. This has the consequence that the parent may be freed while there are still active children,e.g.,
BEGIN { $a = sub { eval '$x' } }In this case, the BEGIN is freed immediately after execution since there are no active references to it: the anon sub prototype hasCvWEAKOUTSIDE set since it's not a closure, and $a points to the same CV, so it doesn't contribute to BEGIN's refcount either. When $a is executed, theeval '$x' causes the chain ofCvOUTSIDEs to be followed, and the freed BEGIN is accessed.
To avoid this, whenever a CV and its associated pad is freed, any& entries in the pad are explicitly removed from the pad, and if the refcount of the pointed-to anon sub is still positive, then that child'sCvOUTSIDE is set to point to its grandparent. This will only occur in the single specific case of a non-closure anon prototype having one or more active references (such as$a above).
One other thing to consider is that a CV may be merely undefined rather than freed, egundef &foo. In this case, its refcount may not have reached zero, but we still delete its pad and itsCvROOT etc. Since various children may still have theirCvOUTSIDE pointing at this undefined CV, we keep its ownCvOUTSIDE for the time being, so that the chain of lexical scopes is unbroken. For example, the following should print 123:
my $x = 123; sub tmp { sub { eval '$x' } } my $a = tmp(); undef &tmp; print $a->();boolCvWEAKOUTSIDE(CV *cv)dump the contents of a CV
voidcv_dump(CV *cv, const char *title)When a CV has a reference count on its slab (CvSLABBED), it is responsible for making sure it is freed. (Hence, no two CVs should ever have a reference count on the same slab.) The CV only needs to reference the slab during compilation. Once it is compiled andCvROOT attached, it has finished its job, so it can forget the slab.
voidcv_forget_slab(CV *cv)Dump the contents of a padlist
voiddo_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full)Allocates a place in the currently-compiling pad (via"pad_alloc" in perlapi) and then stores a name for that entry.name is adopted and becomes the name entry; it must already contain the name string.typestash andourstash and thepadadd_STATE flag get added toname. None of the other processing of"pad_add_name_pvn" in perlapi is done. Returns the offset of the allocated pad slot.
PADOFFSET pad_alloc_name(PADNAME *name, U32 flags, HV *typestash, HV *ourstash)Update the pad compilation state variables on entry to a new block.
voidpad_block_start(int full)Check for duplicate declarations: report any of:
* a 'my' in the current scope with the same name;* an 'our' (anywhere in the pad) with the same name and the same stash as 'ourstash'is_our indicates that the name to check is an"our" declaration.
voidpad_check_dup(PADNAME *name, U32 flags, const HV *ourstash)Find a named lexical anywhere in a chain of nested pads. Add fake entries in the inner pads if it's found in an outer one.
Returns the offset in the bottom pad of the lex or the fake lex.cv is the CV in which to start the search, and seq is the currentcop_seq to match against. Ifwarn is true, print appropriate warnings. Theout_* vars return values, and so are pointers to where the returned values should be stored.out_capture, if non-null, requests that the innermost instance of the lexical is captured;out_name is set to the innermost matched pad name or fake pad name;out_flags returns the flags normally associated with thePARENT_FAKELEX_FLAGS field of a fake pad name.
Note thatpad_findlex() is recursive; it recurses up the chain of CVs, then comes back down, adding fake entries as it goes. It has to be this way because fake names in anon protoypes have to store inxlow the index into the parent pad.
PADOFFSET pad_findlex(const char *namepv, STRLEN namelen, U32 flags, const CV* cv, U32 seq, int warn, SV** out_capture, PADNAME** out_name, int *out_flags)For any anon CVs in the pad, changeCvOUTSIDE of that CV fromold_cv tonew_cv if necessary. Needed when a newly-compiled CV has to be moved to a pre-existing CV struct.
voidpad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv)Free the SV at offset po in the current pad.
voidpad_free(PADOFFSET po)Cleanup at end of scope during compilation: set the max seq number for lexicals in this scope and warn of any lexicals that never got introduced.
voidpad_leavemy()Duplicates a pad.
PADLIST * padlist_dup(PADLIST *srcpad, CLONE_PARAMS *param)Duplicates a pad name.
PADNAME * padname_dup(PADNAME *src, CLONE_PARAMS *param)Duplicates a pad name list.
PADNAMELIST * padnamelist_dup(PADNAMELIST *srcpad, CLONE_PARAMS *param)Push a new pad frame onto the padlist, unless there's already a pad at this depth, in which case don't bother creating a new one. Then give the new pad an@_ in slot zero.
voidpad_push(PADLIST *padlist, int depth)Mark all the current temporaries for reuse
voidpad_reset()Abandon the tmp in the current pad at offsetpo and replace with a new one.
voidpad_swipe(PADOFFSET po, bool refadjust)NOTE: this function is experimental and may change or be removed without notice.
If the typeglobgv can be expressed more succinctly, by having something other than a real GV in its place in the stash, replace it with the optimised form. Basic requirements for this are thatgv is a real typeglob, is sufficiently ordinary, and is only referenced from its package. This function is meant to be used when a GV has been looked up in part to see what was there, causing upgrading, but based on what was found it turns out that the real GV isn't required after all.
Ifgv is a completely empty typeglob, it is deleted from the stash.
Ifgv is a typeglob containing only a sufficiently-ordinary constant sub, the typeglob is replaced with a scalar-reference placeholder that more compactly represents the same thing.
voidgv_try_downgrade(GV* gv)Adds a name to a stash's internal list of effective names. See"hv_ename_delete".
This is called when a stash is assigned to a new location in the symbol table.
voidhv_ename_add(HV *hv, const char *name, U32 len, U32 flags)Removes a name from a stash's internal list of effective names. If this is the name returned byHvENAME, then another name in the list will take its place (HvENAME will use it).
This is called when a stash is deleted from the symbol table.
voidhv_ename_delete(HV *hv, const char *name, U32 len, U32 flags)Generates and returns aHV * representing the content of arefcounted_he chain.flags is currently unused and must be zero.
HV *refcounted_he_chain_2hv( const struct refcounted_he *c, U32 flags)Like"refcounted_he_fetch_pvn", but takes a nul-terminated string instead of a string/length pair.
SV *refcounted_he_fetch_pv( const struct refcounted_he *chain, const char *key, U32 hash, U32 flags)Search along arefcounted_he chain for an entry with the key specified bykeypv andkeylen. Ifflags has theREFCOUNTED_HE_KEY_UTF8 bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1.hash is a precomputed hash of the key string, or zero if it has not been precomputed. Returns a mortal scalar representing the value associated with the key, or&PL_sv_placeholder if there is no value associated with the key.
SV *refcounted_he_fetch_pvn( const struct refcounted_he *chain, const char *keypv, STRLEN keylen, U32 hash, U32 flags)Like"refcounted_he_fetch_pvn", but takes aNUL-terminated literal string instead of a string/length pair, and no precomputed hash.
SV *refcounted_he_fetch_pvs( const struct refcounted_he *chain, const char *key, U32 flags)Like"refcounted_he_fetch_pvn", but takes a Perl scalar instead of a string/length pair.
SV *refcounted_he_fetch_sv( const struct refcounted_he *chain, SV *key, U32 hash, U32 flags)Decrements the reference count of arefcounted_he by one. If the reference count reaches zero the structure's memory is freed, which (recursively) causes a reduction of its parentrefcounted_he's reference count. It is safe to pass a null pointer to this function: no action occurs in this case.
voidrefcounted_he_free(struct refcounted_he *he)Increment the reference count of arefcounted_he. The pointer to therefcounted_he is also returned. It is safe to pass a null pointer to this function: no action occurs and a null pointer is returned.
struct refcounted_he * refcounted_he_inc( struct refcounted_he *he )Like"refcounted_he_new_pvn", but takes a nul-terminated string instead of a string/length pair.
struct refcounted_he * refcounted_he_new_pv( struct refcounted_he *parent, const char *key, U32 hash, SV *value, U32 flags )Creates a newrefcounted_he. This consists of a single key/value pair and a reference to an existingrefcounted_he chain (which may be empty), and thus forms a longer chain. When using the longer chain, the new key/value pair takes precedence over any entry for the same key further along the chain.
The new key is specified bykeypv andkeylen. Ifflags has theREFCOUNTED_HE_KEY_UTF8 bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1.hash is a precomputed hash of the key string, or zero if it has not been precomputed.
value is the scalar value to store for this key.value is copied by this function, which thus does not take ownership of any reference to it, and later changes to the scalar will not be reflected in the value visible in therefcounted_he. Complex types of scalar will not be stored with referential integrity, but will be coerced to strings.value may be either null or&PL_sv_placeholder to indicate that no value is to be associated with the key; this, as with any non-null value, takes precedence over the existence of a value for the key further along the chain.
parent points to the rest of therefcounted_he chain to be attached to the newrefcounted_he. This function takes ownership of one reference toparent, and returns one reference to the newrefcounted_he.
struct refcounted_he * refcounted_he_new_pvn( struct refcounted_he *parent, const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags )Like"refcounted_he_new_pvn", but takes aNUL-terminated literal string instead of a string/length pair, and no precomputed hash.
struct refcounted_he * refcounted_he_new_pvs( struct refcounted_he *parent, const char *key, SV *value, U32 flags )Like"refcounted_he_new_pvn", but takes a Perl scalar instead of a string/length pair.
struct refcounted_he * refcounted_he_new_sv( struct refcounted_he *parent, SV *key, U32 hash, SV *value, U32 flags )NOTE: this function is experimental and may change or be removed without notice.
Function called bydo_readline to spawn a glob (or do the glob inside perl on VMS). This code used to be inline, but now perl usesFile::Glob this glob starter is only used by miniperl during the build process, or when PERL_EXTERNAL_GLOB is defined. Moving it away shrinkspp_hot.c; shrinkingpp_hot.c helps speed perl up.
PerlIO*start_glob(SV *tmpglob, IO *io)NOTE: this function is experimental and may change or be removed without notice.
This function performs syntax checking on a prototype,proto. Ifwarn is true, any illegal characters or mismatched brackets will trigger illegalproto warnings, declaring that they were detected in the prototype forname.
The return value istrue if this is a valid prototype, andfalse if it is not, regardless of whetherwarn wastrue orfalse.
Note thatNULL is a validproto and will always returntrue.
NOTE: the perl_ form of this function is deprecated.
boolvalidate_proto(SV *name, SV *proto, bool warn)Triggered by a delete from%^H, records the key toPL_compiling.cop_hints_hash.
intmagic_clearhint(SV* sv, MAGIC* mg)Triggered by clearing%^H, resetsPL_compiling.cop_hints_hash.
intmagic_clearhints(SV* sv, MAGIC* mg)Invoke a magic method (like FETCH).
sv andmg are the tied thingy and the tie magic.
meth is the name of the method to call.
argc is the number of args (in addition to $self) to pass to the method.
Theflags can be:
G_DISCARD invoke method with G_DISCARD flag and don't return a valueG_UNDEF_FILL fill the stack with argc pointers to PL_sv_undefThe arguments themselves are any values following theflags argument.
Returns the SV (if any) returned by the method, orNULL on failure.
SV*magic_methcall(SV *sv, const MAGIC *mg, SV *meth, U32 flags, U32 argc, ...)Triggered by a store to%^H, records the key/value pair toPL_compiling.cop_hints_hash. It is assumed that hints aren't storing anything that would need a deep copy. Maybe we should warn if we find a reference.
intmagic_sethint(SV* sv, MAGIC* mg)Copy some of the magic from an existing SV to new localized version of that SV. Container magic (e.g.,%ENV,$1,tie) gets copied, value magic doesn't (e.g.,taint,pos).
Ifsetmagic is false then no set magic will be called on the new (empty) SV. This typically means that assignment will soon follow (e.g.'local $x = $y'), and that will handle the magic.
voidmg_localize(SV* sv, SV* nsv, bool setmagic)Deallocates a backtrace received from get_c_bracktrace.
voidfree_c_backtrace(Perl_c_backtrace* bt)Collects the backtrace (aka "stacktrace") into a single linear malloced buffer, which the callermustPerl_free_c_backtrace().
Scans the frames back bydepth + skip, then drops theskip innermost, returning at mostdepth frames.
Perl_c_backtrace* get_c_backtrace(int max_depth, int skip)Returns the Depth-First Search linearization of@ISA the given stash. The return value is a read-only AV*.level should be 0 (it is used internally in this function's recursion).
You are responsible forSvREFCNT_inc() on the return value if you plan to store it anywhere semi-permanently (otherwise it might be deleted out from under you the next time the cache is invalidated).
AV*mro_get_linear_isa_dfs(HV* stash, U32 level)Takes the necessary steps (cache invalidations, mostly) when the@ISA of the given package has changed. Invoked by thesetisa magic, should not need to invoke directly.
voidmro_isa_changed_in(HV* stash)Call this function to signal to a stash that it has been assigned to another spot in the stash hierarchy.stash is the stash that has been assigned.oldstash is the stash it replaces, if any.gv is the glob that is actually being assigned to.
This can also be called with a null first argument to indicate thatoldstash has been deleted.
This function invalidates isa caches on the old stash, on all subpackages nested inside it, and on the subclasses of all those, including non-existent packages that have corresponding entries instash.
It also sets the effective names (HvENAME) on all the stashes as appropriate.
If thegv is present and is not in the symbol table, then this function simply returns. This checked will be skipped ifflags & 1.
voidmro_package_moved(HV * const stash, HV * const oldstash, const GV * const gv, U32 flags)This function finalizes the optree. Should be called directly after the complete optree is built. It does some additional checking which can't be done in the normalck_xxx functions and makes the tree thread-safe.
voidfinalize_optree(OP* o)Save the current pad in the given context block structure.
voidCX_CURPAD_SAVE(struct context)Access the SV at offsetpo in the saved current pad in the given context block structure (can be used as an lvalue).
SV *CX_CURPAD_SV(struct context, PADOFFSET po)Get the value from slotpo in the base (DEPTH=1) pad of a padlist
SV *PAD_BASE_SV(PADLIST padlist, PADOFFSET po)Clone the state variables associated with running and compiling pads.
voidPAD_CLONE_VARS(PerlInterpreter *proto_perl, CLONE_PARAMS* param)Return the flags for the current compiling pad name at offsetpo. Assumes a valid slot entry.
U32PAD_COMPNAME_FLAGS(PADOFFSET po)The generation number of the name at offsetpo in the current compiling pad (lvalue).
STRLENPAD_COMPNAME_GEN(PADOFFSET po)Sets the generation number of the name at offsetpo in the current ling pad (lvalue) togen. STRLEN PAD_COMPNAME_GEN_set(PADOFFSET po, int gen)
Return the stash associated with anour variable. Assumes the slot entry is a validour lexical.
HV *PAD_COMPNAME_OURSTASH(PADOFFSET po)Return the name of the current compiling pad name at offsetpo. Assumes a valid slot entry.
char *PAD_COMPNAME_PV(PADOFFSET po)Return the type (stash) of the current compiling pad name at offsetpo. Must be a valid name. Returns null if not typed.
HV *PAD_COMPNAME_TYPE(PADOFFSET po)Whether this is an "our" variable.
boolPadnameIsOUR(PADNAME pn)Whether this is a "state" variable.
boolPadnameIsSTATE(PADNAME pn)The stash in which this "our" variable was declared.
HV *PadnameOURSTASH()Whether this entry belongs to an outer pad. Entries for which this is true are often referred to as 'fake'.
boolPadnameOUTER(PADNAME pn)The stash associated with a typed lexical. This returns the%Foo:: hash formy Foo $bar.
HV *PadnameTYPE(PADNAME pn)Restore the old pad saved into the local variableopad byPAD_SAVE_LOCAL()
voidPAD_RESTORE_LOCAL(PAD *opad)Save the current pad to the local variableopad, then make the current pad equal tonpad
voidPAD_SAVE_LOCAL(PAD *opad, PAD *npad)Save the current pad then set it to null.
voidPAD_SAVE_SETNULLPAD()Set the slot at offsetpo in the current pad tosv
SV *PAD_SETSV(PADOFFSET po, SV* sv)Set the current pad to be padn in the padlist, saving the previous current pad. NB currently this macro expands to a string too long for some compilers, so it's best to replace it with
SAVECOMPPAD(); PAD_SET_CUR_NOSAVE(padlist,n);voidPAD_SET_CUR(PADLIST padlist, I32 n)like PAD_SET_CUR, but without the save
voidPAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)Get the value at offsetpo in the current pad
SV *PAD_SV(PADOFFSET po)Lightweight and lvalue version ofPAD_SV. Get or set the value at offsetpo in the current pad. UnlikePAD_SV, does not print diagnostics with -DX. For internal use only.
SV *PAD_SVl(PADOFFSET po)Clear the pointed to pad value on scope exit. (i.e. the runtime action ofmy)
voidSAVECLEARSV(SV **svp)savePL_comppad andPL_curpad
voidSAVECOMPPAD()Save a pad slot (used to restore after an iteration)
XXX DAPM it would make more sense to make the arg a PADOFFSET void SAVEPADSV(PADOFFSET po)
When Perl is run in debugging mode, with the-d switch, this SV is a boolean which indicates whether subs are being single-stepped. Single-stepping is automatically turned on after every step. This is the C variable which corresponds to Perl's $DB::single variable. See"PL_DBsub".
SV *PL_DBsingleWhen Perl is run in debugging mode, with the-d switch, this GV contains the SV which holds the name of the sub being debugged. This is the C variable which corresponds to Perl's $DB::sub variable. See"PL_DBsingle".
GV *PL_DBsubTrace variable used when Perl is run in debugging mode, with the-d switch. This is the C variable which corresponds to Perl's $DB::trace variable. See"PL_DBsingle".
SV *PL_DBtraceThe C variable which corresponds to Perl's$^W warning variable.
boolPL_dowarnThe GV which was last used for a filehandle input operation. (<FH>)
GV*PL_last_in_gvThe glob containing the output field separator -*, in Perl space.
GV*PL_ofsgvThe input record separator -$/ in Perl space.
SV*PL_rsDeclare JustSP. This is actually identical todSP, and declares a local copy of perl's stack pointer, available via theSP macro. See"SP" in perlapi. (Available for backward source code compatibility with the old (Perl 5.005) thread model.)
djSP;True if this op will be the return value of an lvalue subroutine
NOTE: this function is experimental and may change or be removed without notice.
Return an SV with the numeric value of the source SV, doing any necessary reference or overload conversion. The caller is expected to have handled get-magic already.
SV*sv_2num(SV *const sv)Copies a stringified representation of the source SV into the destination SV. Automatically performs any necessarymg_get and coercion of numeric values into strings. Guaranteed to preserveUTF8 flag even from overloaded objects. Similar in nature tosv_2pv[_flags] but operates directly on an SV instead of just the string. Mostly usessv_2pv_flags to do its work, except when that would lose the UTF-8'ness of the PV.
voidsv_copypv(SV *const dsv, SV *const ssv)An SV (or AV, HV, etc.) is allocated in two parts: the head (struct sv, av, hv...) contains type and reference count information, and for many types, a pointer to the body (struct xrv, xpv, xpviv...), which contains fields specific to each type. Some types store all they need in the head, so don't have a body.
In all but the most memory-paranoid configurations (ex: PURIFY), heads and bodies are allocated out of arenas, which by default are approximately 4K chunks of memory parcelled up into N heads or bodies. Sv-bodies are allocated by their sv-type, guaranteeing size consistency needed to allocate safely from arrays.
For SV-heads, the first slot in each arena is reserved, and holds a link to the next arena, some flags, and a note of the number of slots. Snaked through each arena chain is a linked list of free items; when this becomes empty, an extra arena is allocated and divided up into N items which are threaded into the free list.
SV-bodies are similar, but they use arena-sets by default, which separate the link and info from the arena itself, and reclaim the 1st slot in the arena. SV-bodies are further described later.
The following global variables are associated with arenas:
PL_sv_arenaroot pointer to list of SV arenasPL_sv_root pointer to list of free SV structuresPL_body_arenas head of linked-list of body arenasPL_body_roots[] array of pointers to list of free bodies of svtype arrays are indexed by the svtype neededA few special SV heads are not allocated from an arena, but are instead directly created in the interpreter structure, eg PL_sv_undef. The size of arenas can be changed from the default by setting PERL_ARENA_SIZE appropriately at compile time.
The SV arena serves the secondary purpose of allowing still-live SVs to be located and destroyed during final cleanup.
At the lowest level, the macros new_SV() and del_SV() grab and free an SV head. (If debugging with -DD, del_SV() calls the function S_del_sv() to return the SV to the free list with error checking.) new_SV() calls more_sv() / sv_add_arena() to add an extra arena if the free list is empty. SVs in the free list have their SvTYPE field set to all ones.
At the time of very final cleanup, sv_free_arenas() is called from perl_destruct() to physically free all the arenas allocated since the start of the interpreter.
The function visit() scans the SV arenas list, and calls a specified function for each SV it finds which is still live - ie which has an SvTYPE other than all 1's, and a non-zero SvREFCNT. visit() is used by the following functions (specified as [function that calls visit()] / [function called by visit() for each SV]):
sv_report_used() / do_report_used()dump all remaining SVs (debugging aid) sv_clean_objs() / do_clean_objs(),do_clean_named_objs(), do_clean_named_io_objs(),do_curse()Attempt to free all objects pointed to by RVs,try to do the same for all objects indir-ectly referenced by typeglobs too, andthen do a final sweep, cursing anyobjects that remain. Called once fromperl_destruct(), prior to calling sv_clean_all()below. sv_clean_all() / do_clean_all()SvREFCNT_dec(sv) each remaining SV, possiblytriggering an sv_free(). It also sets theSVf_BREAK flag on the SV to indicate that therefcnt has been artificially lowered, and thusstopping sv_free() from giving spurious warningsabout SVs which unexpectedly have a refcntof zero. called repeatedly from perl_destruct()until there are no SVs left.Given a chunk of memory, link it to the head of the list of arenas, and split it into a list of free SVs.
voidsv_add_arena(char *const ptr, const U32 size, const U32 flags)Decrement the refcnt of each remaining SV, possibly triggering a cleanup. This function may have to be called multiple times to free SVs which are in complex self-referential hierarchies.
I32sv_clean_all()Attempt to destroy all objects not yet freed.
voidsv_clean_objs()Deallocate the memory used by all arenas. Note that all the individual SV heads and bodies within the arenas must already have been freed.
voidsv_free_arenas()A quick flag check to see whether ansv should be passed tosv_force_normal to be "downgraded" beforeSvIVX orSvPVX can be modified directly.
For example, if your scalar is a reference and you want to modify theSvIVX slot, you can't just doSvROK_off, as that will leak the referent.
This is used internally by various sv-modifying functions, such assv_setsv,sv_setiv andsv_pvn_force.
One case that this does not handle is a gv without SvFAKE set. After
if (SvTHINKFIRST(gv)) sv_force_normal(gv);it will still be a gv.
SvTHINKFIRST sometimes produces false positives. In those casessv_force_normal does nothing.
U32SvTHINKFIRST(SV *sv)NOTE: this function is experimental and may change or be removed without notice.
Find the name of the undefined variable (if any) that caused the operator to issue a "Use of uninitialized value" warning. If match is true, only return a name if its value matchesuninit_sv. So roughly speaking, if a unary operator (such asOP_COS) generates a warning, then following the direct child of the op may yield anOP_PADSV orOP_GV that gives the name of the undefined variable. On the other hand, withOP_ADD there are two branches to follow, so we only print the variable name if we get an exact match.desc_p points to a string pointer holding the description of the op. This may be updated if needed.
The name is returned as a mortal SV.
Assumes thatPL_op is the OP that originally triggered the error, and thatPL_comppad/PL_curpad points to the currently executing pad.
SV*find_uninit_var(const OP *const obase, const SV *const uninit_sv, bool match, const char **desc_p)Print appropriate "Use of uninitialized variable" warning.
voidreport_uninit(const SV *uninit_sv)The following functions are currently undocumented. If you use one of them, you may wish to consider creating and submitting documentation for it.
The autodocumentation system was originally added to the Perl core by Benjamin Stuhl. Documentation is by whoever was kind enough to document their functions.
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