int AvFILLp(AV* av)
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 return "NULL". The type of the return value depends on which entry you ask for.
void * BhkENTRY(BHK *hk, which)
Return the BHK's flags.
U32 BhkFLAGS(BHK *hk)
Call all the registered block hooks for type "which". "which" is a preprocessing token; the type of "arg" depends on "which".
void CALL_BLOCK_HOOKS(which, arg)
SV * core_prototype(SV *sv, const char *name,
const int code,
int * const opnum)
0 is used as continue inside eval,
3 is used for a die caught by an inner eval - continue inner loop
See cop.h: je_mustcatch, when set at any runlevel to TRUE, means eval ops must establish a local jmpenv to handle exception traps.
OP* docatch(Perl_ppaddr_t firstpp)
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 has "CvWEAKOUTSIDE" 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 $a is executed, the "eval '$x'" causes the chain of "CvOUTSIDE"s 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's "CvOUTSIDE" 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, eg "undef &foo". In this case, its refcount may not have reached zero, but we still delete its pad and its "CvROOT" etc. Since various children may still have their "CvOUTSIDE" pointing at this undefined CV, we keep its own "CvOUTSIDE" 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->();
bool CvWEAKOUTSIDE(CV *cv)
void cv_dump(const CV *cv, const char *title)
void cv_forget_slab(CV *cv)
void do_dump_pad(I32 level, PerlIO *file,
PADLIST *padlist, int full)
PADOFFSET pad_alloc_name(PADNAME *name, U32 flags,
HV *typestash, HV *ourstash)
void pad_block_start(int full)
* 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.
void pad_check_dup(PADNAME *name, U32 flags,
const HV *ourstash)
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 current "cop_seq" to match against. If "warn" is true, print appropriate warnings. The "out_"* 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 the "PARENT_FAKELEX_FLAGS" field of a fake pad name.
Note that "pad_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 in "xpadn_low" 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)
void pad_fixup_inner_anons(PADLIST *padlist,
CV *old_cv, CV *new_cv)
void pad_free(PADOFFSET po)
OP * pad_leavemy()
PADLIST * padlist_dup(PADLIST *srcpad,
CLONE_PARAMS *param)
PADNAME * padname_dup(PADNAME *src, CLONE_PARAMS *param)
PADNAMELIST * padnamelist_dup(PADNAMELIST *srcpad,
CLONE_PARAMS *param)
void pad_push(PADLIST *padlist, int depth)
void pad_reset()
void pad_swipe(PADOFFSET po, bool refadjust)
void dSAVEDERRNO
void dSAVE_ERRNO
void RESTORE_ERRNO
void SAVE_ERRNO
void SETERRNO(int errcode, int vmserrcode)
If the typeglob "gv" 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 that "gv" 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.
If "gv" is a completely empty typeglob, it is deleted from the stash.
If "gv" 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.
void gv_try_downgrade(GV* gv)
This is called when a stash is assigned to a new location in the symbol table.
void hv_ename_add(HV *hv, const char *name, U32 len,
U32 flags)
This is called when a stash is deleted from the symbol table.
void hv_ename_delete(HV *hv, const char *name,
U32 len, U32 flags)
HV * refcounted_he_chain_2hv(
const struct refcounted_he *c, U32 flags
)
SV * refcounted_he_fetch_pv(
const struct refcounted_he *chain,
const char *key, U32 hash, U32 flags
)
SV * refcounted_he_fetch_pvn(
const struct refcounted_he *chain,
const char *keypv, STRLEN keylen, U32 hash,
U32 flags
)
SV * refcounted_he_fetch_pvs(
const struct refcounted_he *chain, "key",
U32 flags
)
SV * refcounted_he_fetch_sv(
const struct refcounted_he *chain, SV *key,
U32 hash, U32 flags
)
void refcounted_he_free(struct refcounted_he *he)
struct refcounted_he * refcounted_he_inc(
struct refcounted_he *he
)
struct refcounted_he * refcounted_he_new_pv(
struct refcounted_he *parent,
const char *key, U32 hash,
SV *value, U32 flags
)
The new key is specified by "keypv" and "keylen". If "flags" has the "REFCOUNTED_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 the "refcounted_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 the "refcounted_he" chain to be attached to the new "refcounted_he". This function takes ownership of one reference to "parent", and returns one reference to the new "refcounted_he".
struct refcounted_he * refcounted_he_new_pvn(
struct refcounted_he *parent,
const char *keypv,
STRLEN keylen, U32 hash,
SV *value, U32 flags
)
struct refcounted_he * refcounted_he_new_pvs(
struct refcounted_he *parent,
"key", SV *value, U32 flags
)
struct refcounted_he * refcounted_he_new_sv(
struct refcounted_he *parent,
SV *key, U32 hash, SV *value,
U32 flags
)
Function called by "do_readline" to spawn a glob (or do the glob inside perl on VMS). This code used to be inline, but now perl uses "File::Glob" this glob starter is only used by miniperl during the build process, or when PERL_EXTERNAL_GLOB is defined. Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up.
NOTE: this function must be explicitly called as Perl_start_glob with an aTHX_ parameter.
PerlIO* Perl_start_glob(pTHX_ SV *tmpglob, IO *io)
This function performs syntax checking on a prototype, "proto". If "warn" is true, any illegal characters or mismatched brackets will trigger illegalproto warnings, declaring that they were detected in the prototype for "name".
The return value is "true" if this is a valid prototype, and "false" if it is not, regardless of whether "warn" was "true" or "false".
Note that "NULL" is a valid "proto" and will always return "true".
bool validate_proto(SV *name, SV *proto, bool warn,
bool curstash)
int magic_clearhint(SV* sv, MAGIC* mg)
int magic_clearhints(SV* sv, MAGIC* mg)
"sv" and "mg" 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.
The "flags" can be:
G_DISCARD invoke method with G_DISCARD flag and don't
return a value
G_UNDEF_FILL fill the stack with argc pointers to
PL_sv_undef
The arguments themselves are any values following the "flags" argument.
Returns the SV (if any) returned by the method, or "NULL" on failure.
NOTE: this function must be explicitly called as Perl_magic_methcall with an aTHX_ parameter.
SV* Perl_magic_methcall(pTHX_ SV *sv,
const MAGIC *mg, SV *meth,
U32 flags, U32 argc, ...)
int magic_sethint(SV* sv, MAGIC* mg)
If "setmagic" 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.
void mg_localize(SV* sv, SV* nsv, bool setmagic)
void free_c_backtrace(Perl_c_backtrace* bt)
Scans the frames back by "depth + skip", then drops the "skip" innermost, returning at most "depth" frames.
Perl_c_backtrace* get_c_backtrace(int max_depth,
int skip)
The format specifier detection is not complete printf-syntax detection, but it should catch most common cases.
If true is returned, those arguments should in theory be processed with "quadmath_snprintf()", but in case there is more than one such format specifier (see ``quadmath_format_valid''), and if there is anything else beyond that one (even just a single byte), they cannot be processed because "quadmath_snprintf()" is very strict, accepting only one format spec, and nothing else. In this case, the code should probably fail.
bool quadmath_format_needed(const char* format)
"quadmath_format_valid()" checks that the intended single spec looks sane: begins with "%", has only one "%", ends with "[efgaEFGA]", and has "Q" before it. This is not a full ``printf syntax check'', just the basics.
Returns true if it is valid, false if not.
See also ``quadmath_format_needed''.
bool quadmath_format_valid(const char* format)
You are responsible for "SvREFCNT_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)
void mro_isa_changed_in(HV* stash)
This can also be called with a null first argument to indicate that "oldstash" 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 in "stash".
It also sets the effective names ("HvENAME") on all the stashes as appropriate.
If the "gv" is present and is not in the symbol table, then this function simply returns. This checked will be skipped if "flags & 1".
void mro_package_moved(HV * const stash,
HV * const oldstash,
const GV * const gv,
U32 flags)
On entry, "pv" points to the beginning of the string; "valptr" points to a UV that will receive the converted value, if found; "endptr" is either NULL or points to a variable that points to one byte beyond the point in "pv" that this routine should examine. If "endptr" is NULL, "pv" is assumed to be NUL-terminated.
Returns FALSE if "pv" doesn't represent a valid unsigned integer value (with no leading zeros). Otherwise it returns TRUE, and sets *valptr to that value.
If you constrain the portion of "pv" that is looked at by this function (by passing a non-NULL "endptr"), and if the intial bytes of that portion form a valid value, it will return TRUE, setting *endptr to the byte following the final digit of the value. But if there is no constraint at what's looked at, all of "pv" must be valid in order for TRUE to be returned. *endptr is unchanged from its value on input if FALSE is returned;
The only characters this accepts are the decimal digits '0'..'9'.
As opposed to atoi(3) or strtol(3), "grok_atoUV" does NOT allow optional leading whitespace, nor negative inputs. If such features are required, the calling code needs to explicitly implement those.
Note that this function returns FALSE for inputs that would overflow a UV, or have leading zeros. Thus a single 0 is accepted, but not 00 nor 01, 002, etc.
Background: "atoi" has severe problems with illegal inputs, it cannot be used for incremental parsing, and therefore should be avoided "atoi" and "strtol" are also affected by locale settings, which can also be seen as a bug (global state controlled by user environment).
bool grok_atoUV(const char* pv, UV* valptr,
const char** endptr)
bool isinfnansv(SV *sv)
Instead use ``utf8_to_uvchr_buf'' in perlapi, or rarely, ``utf8n_to_uvchr'' in perlapi.
This function was useful for code that wanted to handle both EBCDIC and ASCII platforms with Unicode properties, but starting in Perl v5.20, the distinctions between the platforms have mostly been made invisible to most code, so this function is quite unlikely to be what you want. If you do need this precise functionality, use instead "NATIVE_TO_UNI(utf8_to_uvchr_buf(...))" or "NATIVE_TO_UNI(utf8n_to_uvchr(...))".
UV utf8n_to_uvuni(const U8 *s, STRLEN curlen,
STRLEN *retlen, U32 flags)
Returns the Unicode code point of the first character in the string "s" which is assumed to be in UTF-8 encoding; "retlen" will be set to the length, in bytes, of that character.
Some, but not all, UTF-8 malformations are detected, and in fact, some malformed input could cause reading beyond the end of the input buffer, which is one reason why this function is deprecated. The other is that only in extremely limited circumstances should the Unicode versus native code point be of any interest to you. See ``utf8_to_uvuni_buf'' for alternatives.
If "s" points to one of the detected malformations, and UTF8 warnings are enabled, zero is returned and *retlen is set (if "retlen" doesn't point to NULL) to -1. If those warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if not) is silently returned, and *retlen is set (if "retlen" isn't NULL) so that ("s" + *retlen) is the next possible position in "s" that could begin a non-malformed character. See ``utf8n_to_uvchr'' in perlapi for details on when the REPLACEMENT CHARACTER is returned.
UV utf8_to_uvuni(const U8 *s, STRLEN *retlen)
Instead you almost certainly want to use ``uvchr_to_utf8'' in perlapi or ``uvchr_to_utf8_flags'' in perlapi.
This function is a deprecated synonym for ``uvoffuni_to_utf8_flags'', which itself, while not deprecated, should be used only in isolated circumstances. These functions were useful for code that wanted to handle both EBCDIC and ASCII platforms with Unicode properties, but starting in Perl v5.20, the distinctions between the platforms have mostly been made invisible to most code, so this function is quite unlikely to be what you want.
U8* uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)
void finalize_optree(OP* o)
This function is expected to be called in a Perl compilation context, and some aspects of the subroutine are taken from global variables associated with compilation. In particular, "PL_compcv" represents the subroutine that is currently being compiled. It must be non-null when this function is called, and some aspects of the subroutine being constructed are taken from it. The constructed subroutine may actually be a reuse of the "PL_compcv" object, but will not necessarily be so.
If "block" is null then the subroutine will have no body, and for the time being it will be an error to call it. This represents a forward subroutine declaration such as "sub foo ($$);". If "block" is non-null then it provides the Perl code of the subroutine body, which will be executed when the subroutine is called. This body includes any argument unwrapping code resulting from a subroutine signature or similar. The pad use of the code must correspond to the pad attached to "PL_compcv". The code is not expected to include a "leavesub" or "leavesublv" op; this function will add such an op. "block" is consumed by this function and will become part of the constructed subroutine.
"proto" specifies the subroutine's prototype, unless one is supplied as an attribute (see below). If "proto" is null, then the subroutine will not have a prototype. If "proto" is non-null, it must point to a "const" op whose value is a string, and the subroutine will have that string as its prototype. If a prototype is supplied as an attribute, the attribute takes precedence over "proto", but in that case "proto" should preferably be null. In any case, "proto" is consumed by this function.
"attrs" supplies attributes to be applied the subroutine. A handful of attributes take effect by built-in means, being applied to "PL_compcv" immediately when seen. Other attributes are collected up and attached to the subroutine by this route. "attrs" may be null to supply no attributes, or point to a "const" op for a single attribute, or point to a "list" op whose children apart from the "pushmark" are "const" ops for one or more attributes. Each "const" op must be a string, giving the attribute name optionally followed by parenthesised arguments, in the manner in which attributes appear in Perl source. The attributes will be applied to the sub by this function. "attrs" is consumed by this function.
If "o_is_gv" is false and "o" is null, then the subroutine will be anonymous. If "o_is_gv" is false and "o" is non-null, then "o" must point to a "const" op, which will be consumed by this function, and its string value supplies a name for the subroutine. The name may be qualified or unqualified, and if it is unqualified then a default stash will be selected in some manner. If "o_is_gv" is true, then "o" doesn't point to an "OP" at all, but is instead a cast pointer to a "GV" by which the subroutine will be named.
If there is already a subroutine of the specified name, then the new sub will either replace the existing one in the glob or be merged with the existing one. A warning may be generated about redefinition.
If the subroutine has one of a few special names, such as "BEGIN" or "END", then it will be claimed by the appropriate queue for automatic running of phase-related subroutines. In this case the relevant glob will be left not containing any subroutine, even if it did contain one before. In the case of "BEGIN", the subroutine will be executed and the reference to it disposed of before this function returns.
The function returns a pointer to the constructed subroutine. If the sub is anonymous then ownership of one counted reference to the subroutine is transferred to the caller. If the sub is named then the caller does not get ownership of a reference. In most such cases, where the sub has a non-phase name, the sub will be alive at the point it is returned by virtue of being contained in the glob that names it. A phase-named subroutine will usually be alive by virtue of the reference owned by the phase's automatic run queue. But a "BEGIN" subroutine, having already been executed, will quite likely have been destroyed already by the time this function returns, making it erroneous for the caller to make any use of the returned pointer. It is the caller's responsibility to ensure that it knows which of these situations applies.
CV* newATTRSUB_x(I32 floor, OP *o, OP *proto,
OP *attrs, OP *block, bool o_is_gv)
The subroutine will have the entry point "subaddr". It will have the prototype specified by the nul-terminated string "proto", or no prototype if "proto" is null. The prototype string is copied; the caller can mutate the supplied string afterwards. If "filename" is non-null, it must be a nul-terminated filename, and the subroutine will have its "CvFILE" set accordingly. By default "CvFILE" is set to point directly to the supplied string, which must be static. If "flags" has the "XS_DYNAMIC_FILENAME" bit set, then a copy of the string will be taken instead.
Other aspects of the subroutine will be left in their default state. If anything else needs to be done to the subroutine for it to function correctly, it is the caller's responsibility to do that after this function has constructed it. However, beware of the subroutine potentially being destroyed before this function returns, as described below.
If "name" is null then the subroutine will be anonymous, with its "CvGV" referring to an "__ANON__" glob. If "name" is non-null then the subroutine will be named accordingly, referenced by the appropriate glob. "name" is a string of length "len" bytes giving a sigilless symbol name, in UTF-8 if "flags" has the "SVf_UTF8" bit set and in Latin-1 otherwise. The name may be either qualified or unqualified, with the stash defaulting in the same manner as for "gv_fetchpvn_flags". "flags" may contain flag bits understood by "gv_fetchpvn_flags" with the same meaning as they have there, such as "GV_ADDWARN". The symbol is always added to the stash if necessary, with "GV_ADDMULTI" semantics.
If there is already a subroutine of the specified name, then the new sub will replace the existing one in the glob. A warning may be generated about the redefinition. If the old subroutine was "CvCONST" then the decision about whether to warn is influenced by an expectation about whether the new subroutine will become a constant of similar value. That expectation is determined by "const_svp". (Note that the call to this function doesn't make the new subroutine "CvCONST" in any case; that is left to the caller.) If "const_svp" is null then it indicates that the new subroutine will not become a constant. If "const_svp" is non-null then it indicates that the new subroutine will become a constant, and it points to an "SV*" that provides the constant value that the subroutine will have.
If the subroutine has one of a few special names, such as "BEGIN" or "END", then it will be claimed by the appropriate queue for automatic running of phase-related subroutines. In this case the relevant glob will be left not containing any subroutine, even if it did contain one before. In the case of "BEGIN", the subroutine will be executed and the reference to it disposed of before this function returns, and also before its prototype is set. If a "BEGIN" subroutine would not be sufficiently constructed by this function to be ready for execution then the caller must prevent this happening by giving the subroutine a different name.
The function returns a pointer to the constructed subroutine. If the sub is anonymous then ownership of one counted reference to the subroutine is transferred to the caller. If the sub is named then the caller does not get ownership of a reference. In most such cases, where the sub has a non-phase name, the sub will be alive at the point it is returned by virtue of being contained in the glob that names it. A phase-named subroutine will usually be alive by virtue of the reference owned by the phase's automatic run queue. But a "BEGIN" subroutine, having already been executed, will quite likely have been destroyed already by the time this function returns, making it erroneous for the caller to make any use of the returned pointer. It is the caller's responsibility to ensure that it knows which of these situations applies.
CV * newXS_len_flags(const char *name, STRLEN len,
XSUBADDR_t subaddr,
const char *const filename,
const char *const proto,
SV **const_svp, U32 flags)
void optimize_optree(OP* o)
The initial call must supply the root of the tree as both top and o.
For now it's static, but it may be exposed to the API in the future.
OP* traverse_op_tree(OP* top, OP* o)
void CX_CURPAD_SAVE(struct context)
SV * CX_CURPAD_SV(struct context, PADOFFSET po)
SV * PAD_BASE_SV(PADLIST padlist, PADOFFSET po)
void PAD_CLONE_VARS(PerlInterpreter *proto_perl,
CLONE_PARAMS* param)
U32 PAD_COMPNAME_FLAGS(PADOFFSET po)
STRLEN PAD_COMPNAME_GEN(PADOFFSET po)
HV * PAD_COMPNAME_OURSTASH(PADOFFSET po)
char * PAD_COMPNAME_PV(PADOFFSET po)
HV * PAD_COMPNAME_TYPE(PADOFFSET po)
bool PadnameIsOUR(PADNAME * pn)
bool PadnameIsSTATE(PADNAME * pn)
HV * PadnameOURSTASH()
bool PadnameOUTER(PADNAME * pn)
HV * PadnameTYPE(PADNAME * pn)
void PAD_RESTORE_LOCAL(PAD *opad)
void PAD_SAVE_LOCAL(PAD *opad, PAD *npad)
void PAD_SAVE_SETNULLPAD()
SV * PAD_SETSV(PADOFFSET po, SV* sv)
SAVECOMPPAD();
PAD_SET_CUR_NOSAVE(padlist,n);
void PAD_SET_CUR(PADLIST padlist, I32 n)
void PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)
SV * PAD_SV(PADOFFSET po)
SV * PAD_SVl(PADOFFSET po)
void SAVECLEARSV(SV **svp)
void SAVECOMPPAD()
XXX DAPM it would make more sense to make the arg a PADOFFSET
void SAVEPADSV(PADOFFSET po)
SV * PL_DBsingle
GV * PL_DBsub
SV * PL_DBtrace
U8 PL_dowarn
GV* PL_last_in_gv
GV* PL_ofsgv
SV* PL_rs
djSP();
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 arenas
PL_sv_root pointer to list of free SV structures
PL_body_arenas head of linked-list of body arenas
PL_body_roots[] array of pointers to list of free bodies of svtype
arrays are indexed by the svtype needed
A 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, and
then do a final sweep, cursing any
objects that remain. Called once from
perl_destruct(), prior to calling sv_clean_all()
below.
sv_clean_all() / do_clean_all()
SvREFCNT_dec(sv) each remaining SV, possibly
triggering an sv_free(). It also sets the
SVf_BREAK flag on the SV to indicate that the
refcnt has been artificially lowered, and thus
stopping sv_free() from giving spurious warnings
about SVs which unexpectedly have a refcnt
of zero. called repeatedly from perl_destruct()
until there are no SVs left.
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)
void sv_add_arena(char *const ptr, const U32 size,
const U32 flags)
I32 sv_clean_all()
void sv_clean_objs()
void sv_free_arenas()
For example, if your scalar is a reference and you want to modify the "SvIVX" slot, you can't just do "SvROK_off", as that will leak the referent.
This is used internally by various sv-modifying functions, such as "sv_setsv", "sv_setiv" and "sv_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 cases "sv_force_normal" does nothing.
U32 SvTHINKFIRST(SV *sv)
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 matches "uninit_sv". So roughly speaking, if a unary operator (such as "OP_COS") generates a warning, then following the direct child of the op may yield an "OP_PADSV" or "OP_GV" that gives the name of the undefined variable. On the other hand, with "OP_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 that "PL_op" is the OP that originally triggered the error, and that "PL_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)
For example, if all the characters in the sequence are Greek, or Common, or Inherited, this function will return TRUE, provided any decimal digits in it are from the same block of digits in Common. (These are the ASCII digits ``0''..``9'' and additionally a block for full width forms of these, and several others used in mathematical notation.) For scripts (unlike Greek) that have their own digits defined this will accept either digits from that set or from one of the Common digit sets, but not a combination of the two. Some scripts, such as Arabic, have more than one set of digits. All digits must come from the same set for this function to return TRUE.
*ret_script, if "ret_script" is not NULL, will on return of TRUE contain the script found, using the "SCX_enum" typedef. Its value will be "SCX_INVALID" if the function returns FALSE.
If the sequence is empty, TRUE is returned, but *ret_script (if asked for) will be "SCX_INVALID".
If the sequence contains a single code point which is unassigned to a character in the version of Unicode being used, the function will return TRUE, and the script will be "SCX_Unknown". Any other combination of unassigned code points in the input sequence will result in the function treating the input as not being a script run.
The returned script will be "SCX_Inherited" iff all the code points in it are from the Inherited script.
Otherwise, the returned script will be "SCX_Common" iff all the code points in it are from the Inherited or Common scripts.
bool isSCRIPT_RUN(const U8 *s, const U8 *send,
const bool utf8_target)
A TRUE return means that at least one code point represented by the sequence either is a wide character not representable as a single byte, or the representation differs depending on whether the sequence is encoded in UTF-8 or not.
See also ""is_utf8_invariant_string" in perlapi", ""is_utf8_string" in perlapi"
bool is_utf8_non_invariant_string(const U8* const s,
STRLEN len)
void report_uninit(const SV *uninit_sv)
Only in very rare circumstances should code need to be dealing in Unicode (as opposed to native) code points. In those few cases, use "NATIVE_TO_UNI(utf8_to_uvchr_buf(...))" instead. If you are not absolutely sure this is one of those cases, then assume it isn't and use plain "utf8_to_uvchr_buf" instead.
Returns the Unicode (not-native) code point of the first character in the string "s" which is assumed to be in UTF-8 encoding; "send" points to 1 beyond the end of "s". "retlen" will be set to the length, in bytes, of that character.
If "s" does not point to a well-formed UTF-8 character and UTF8 warnings are enabled, zero is returned and *retlen is set (if "retlen" isn't NULL) to -1. If those warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if not) is silently returned, and *retlen is set (if "retlen" isn't NULL) so that ("s" + *retlen) is the next possible position in "s" that could begin a non-malformed character. See ``utf8n_to_uvchr'' in perlapi for details on when the REPLACEMENT CHARACTER is returned.
UV utf8_to_uvuni_buf(const U8 *s, const U8 *send,
STRLEN *retlen)
This function is like them, but the input is a strict Unicode (as opposed to native) code point. Only in very rare circumstances should code not be using the native code point.
For details, see the description for ``uvchr_to_utf8_flags'' in perlapi.
U8* uvoffuni_to_utf8_flags(U8 *d, UV uv,
const UV flags)
UV valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
Unlike most of the other functions that have "utf8" in their name, the input to this function is NOT a UTF-8-encoded string. The function name is slightly odd to emphasize this.
This function is internal to Perl because khw thinks that any XS code that would want this is probably operating too close to the internals. Presenting a valid use case could change that.
See also ""is_utf8_invariant_string" in perlapi" and ""is_utf8_invariant_string_loc" in perlapi",
Size_t variant_under_utf8_count(const U8* const s,
const U8* const e)