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CONTENTS

NAME

perlintern - autogenerated documentation of purely internal Perl functions

DESCRIPTION

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!

It has the same sections as perlapi, though some may be empty.

AV Handling

AvFILLp

If the array av is empty, this returns -1; otherwise it returns the maximum value of the indices of all the array elements which are currently defined in av. It does not handle magic, hence the p private indication in its name.

    SSize_t  AvFILLp(AV* av)

Callback Functions

There are only public API items currently in Callback Functions

Casting

There are only public API items currently in Casting

Character case changing

There are only public API items currently in Character case changing

Character classification

There are only public API items currently in Character classification

Compiler and Preprocessor information

There are only public API items currently in Compiler and Preprocessor information

Compiler directives

There are only public API items currently in Compiler directives

Compile-time scope hooks

BhkENTRY

NOTE: BhkENTRY 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 return NULL. The type of the return value depends on which entry you ask for.

    void *  BhkENTRY(BHK *hk, which)
BhkFLAGS

NOTE: BhkFLAGS is experimental and may change or be removed without notice.

Return the BHK's flags.

    U32  BhkFLAGS(BHK *hk)
CALL_BLOCK_HOOKS

NOTE: CALL_BLOCK_HOOKS is experimental and may change or be removed without notice.

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)

Concurrency

There are only public API items currently in Concurrency

COP Hint Hashes

There are only public API items currently in COP Hint Hashes

Custom Operators

core_prototype

This function assigns the prototype of the named core function to sv, or to a new mortal SV if sv is NULL. It returns the modified sv, or NULL if the core function has no prototype. code is a code as returned by keyword(). It must not be equal to 0.

    SV *  core_prototype(SV *sv, const char *name, const int code,
                         int * const opnum)

CV Handling

CvWEAKOUTSIDE

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 by CvOUTSIDE in the one specific instance that the parent has a & pad slot pointing back to us. In this case, we set the CvWEAKOUTSIDE 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 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 CvOUTSIDEs 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)
docatch

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

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)

Debugging

free_c_backtrace

Deallocates a backtrace received from get_c_backtrace.

    void  free_c_backtrace(Perl_c_backtrace* bt)
get_c_backtrace

Collects the backtrace (aka "stacktrace") into a single linear malloced buffer, which the caller must Perl_free_c_backtrace().

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)
PL_DBsingle

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".

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    SV *  PL_DBsingle
PL_DBsub

When 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".

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    GV *  PL_DBsub
PL_DBtrace

Trace 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".

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    SV *  PL_DBtrace

Display functions

There are only public API items currently in Display functions

Embedding and Interpreter Cloning

cv_dump

dump the contents of a CV

    void  cv_dump(const CV *cv, const char *title)
cv_forget_slab

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 and CvROOT attached, it has finished its job, so it can forget the slab.

    void  cv_forget_slab(CV *cv)
do_dump_pad

Dump the contents of a padlist

    void  do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist,
                      int full)
pad_alloc_name

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 and ourstash and the padadd_STATE flag get added to name. 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)
pad_block_start

Update the pad compilation state variables on entry to a new block.

    void  pad_block_start(int full)
pad_check_dup

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.

    void  pad_check_dup(PADNAME *name, U32 flags, const HV *ourstash)
pad_findlex

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 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 prototypes 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)
pad_fixup_inner_anons

For any anon CVs in the pad, change CvOUTSIDE of that CV from old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be moved to a pre-existing CV struct.

    void  pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv,
                                CV *new_cv)
pad_free

Free the SV at offset po in the current pad.

    void  pad_free(PADOFFSET po)
pad_leavemy

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.

    OP *  pad_leavemy()
padlist_dup

Duplicates a pad.

    PADLIST *  padlist_dup(PADLIST *srcpad, CLONE_PARAMS *param)
padname_dup

Duplicates a pad name.

    PADNAME *  padname_dup(PADNAME *src, CLONE_PARAMS *param)
padnamelist_dup

Duplicates a pad name list.

    PADNAMELIST *  padnamelist_dup(PADNAMELIST *srcpad,
                                   CLONE_PARAMS *param)
pad_push

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.

    void  pad_push(PADLIST *padlist, int depth)
pad_reset

Mark all the current temporaries for reuse

    void  pad_reset()
pad_setsv

Set the value at offset po in the current (compiling or executing) pad. Use the macro PAD_SETSV() rather than calling this function directly.

    void  pad_setsv(PADOFFSET po, SV* sv)
pad_sv

Get the value at offset po in the current (compiling or executing) pad. Use macro PAD_SV instead of calling this function directly.

    SV*  pad_sv(PADOFFSET po)
pad_swipe

Abandon the tmp in the current pad at offset po and replace with a new one.

    void  pad_swipe(PADOFFSET po, bool refadjust)

Errno

dSAVEDERRNO

Declare variables needed to save errno and any operating system specific error number.

    void  dSAVEDERRNO
dSAVE_ERRNO

Declare variables needed to save errno and any operating system specific error number, and save them for optional later restoration by RESTORE_ERRNO.

    void  dSAVE_ERRNO
RESTORE_ERRNO

Restore errno and any operating system specific error number that was saved by dSAVE_ERRNO or RESTORE_ERRNO.

    void  RESTORE_ERRNO
SAVE_ERRNO

Save errno and any operating system specific error number for optional later restoration by RESTORE_ERRNO. Requires dSAVEDERRNO or dSAVE_ERRNO in scope.

    void  SAVE_ERRNO
SETERRNO

Set errno, and on VMS set vaxc$errno.

    void  SETERRNO(int errcode, int vmserrcode)

Exception Handling (simple) Macros

There are only public API items currently in Exception Handling (simple) Macros

Filesystem configuration values

There are only public API items currently in Filesystem configuration values

Floating point configuration values

There are only public API items currently in Floating point configuration values

Formats

There are only public API items currently in Formats

General Configuration

There are only public API items currently in General Configuration

Global Variables

There are only public API items currently in Global Variables

GV Handling

gv_try_downgrade

NOTE: gv_try_downgrade is experimental and may change or be removed without notice.

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)

Hook manipulation

There are only public API items currently in Hook manipulation

HV Handling

hv_ename_add

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.

    void  hv_ename_add(HV *hv, const char *name, U32 len, U32 flags)
hv_ename_delete

Removes a name from a stash's internal list of effective names. If this is the name returned by HvENAME, 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.

    void  hv_ename_delete(HV *hv, const char *name, U32 len,
                          U32 flags)
refcounted_he_chain_2hv

Generates and returns a HV * representing the content of a refcounted_he chain. flags is currently unused and must be zero.

    HV *  refcounted_he_chain_2hv(const struct refcounted_he *c,
                                  U32 flags)
refcounted_he_fetch_pv

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)
refcounted_he_fetch_pvn

Search along a refcounted_he chain for an entry with the key 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. 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)
refcounted_he_fetch_pvs

Like "refcounted_he_fetch_pvn", but takes a literal string instead of a string/length pair, and no precomputed hash.

    SV *  refcounted_he_fetch_pvs(const struct refcounted_he *chain,
                                  "key", U32 flags)
refcounted_he_fetch_sv

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)
refcounted_he_free

Decrements the reference count of a refcounted_he by one. If the reference count reaches zero the structure's memory is freed, which (recursively) causes a reduction of its parent refcounted_he's reference count. It is safe to pass a null pointer to this function: no action occurs in this case.

    void  refcounted_he_free(struct refcounted_he *he)
refcounted_he_inc

Increment the reference count of a refcounted_he. The pointer to the refcounted_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)
refcounted_he_new_pv

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)
refcounted_he_new_pvn

Creates a new refcounted_he. This consists of a single key/value pair and a reference to an existing refcounted_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 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)
refcounted_he_new_pvs

Like "refcounted_he_new_pvn", but takes a literal string instead of a string/length pair, and no precomputed hash.

    struct refcounted_he *  refcounted_he_new_pvs(
                                         struct refcounted_he *parent,
                                         "key", SV *value, U32 flags)
refcounted_he_new_sv

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)

Input/Output

PL_last_in_gv

The GV which was last used for a filehandle input operation. (<FH>)

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    GV*  PL_last_in_gv
PL_ofsgv

The glob containing the output field separator - *, in Perl space.

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    GV*  PL_ofsgv
PL_rs

The input record separator - $/ in Perl space.

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    SV*  PL_rs
start_glob

NOTE: start_glob is experimental and may change or be removed without notice.

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: start_glob must be explicitly called as Perl_start_glob with an aTHX_ parameter.

    PerlIO*  Perl_start_glob(pTHX_ SV *tmpglob, IO *io)

Integer configuration values

There are only public API items currently in Integer configuration values

Lexer interface

validate_proto

NOTE: validate_proto is experimental and may change or be removed without notice.

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)

Locales

There are only public API items currently in Locales

Magic

magic_clearhint

Triggered by a delete from %^H, records the key to PL_compiling.cop_hints_hash.

    int  magic_clearhint(SV* sv, MAGIC* mg)
magic_clearhints

Triggered by clearing %^H, resets PL_compiling.cop_hints_hash.

    int  magic_clearhints(SV* sv, MAGIC* mg)
magic_methcall

Invoke a magic method (like FETCH).

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: magic_methcall 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, ...)
magic_sethint

Triggered by a store to %^H, records the key/value pair to PL_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.

    int  magic_sethint(SV* sv, MAGIC* mg)
mg_localize

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).

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)

Memory Management

There are only public API items currently in Memory Management

MRO

mro_get_linear_isa_dfs

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 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)
mro_isa_changed_in

Takes the necessary steps (cache invalidations, mostly) when the @ISA of the given package has changed. Invoked by the setisa magic, should not need to invoke directly.

    void  mro_isa_changed_in(HV* stash)
mro_package_moved

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 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)

Multicall Functions

There are only public API items currently in Multicall Functions

Numeric Functions

grok_atoUV

parse a string, looking for a decimal unsigned integer.

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)
isinfnansv

Checks whether the argument would be either an infinity or NaN when used as a number, but is careful not to trigger non-numeric or uninitialized warnings. it assumes the caller has done SvGETMAGIC(sv) already.

    bool  isinfnansv(SV *sv)

Optree construction

There are only public API items currently in Optree construction

Optree Manipulation Functions

finalize_optree

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 normal ck_xxx functions and makes the tree thread-safe.

    void  finalize_optree(OP* o)
newATTRSUB_x

Construct a Perl subroutine, also performing some surrounding jobs.

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)
newXS_len_flags

Construct an XS subroutine, also performing some surrounding jobs.

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)
optimize_optree

This function applies some optimisations to the optree in top-down order. It is called before the peephole optimizer, which processes ops in execution order. Note that finalize_optree() also does a top-down scan, but is called *after* the peephole optimizer.

    void  optimize_optree(OP* o)
traverse_op_tree

Return the next op in a depth-first traversal of the op tree, returning NULL when the traversal is complete.

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)

Pack and Unpack

There are only public API items currently in Pack and Unpack

Pad Data Structures

CX_CURPAD_SAVE

Save the current pad in the given context block structure.

    void  CX_CURPAD_SAVE(struct context)
CX_CURPAD_SV

Access the SV at offset po 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)
PAD_BASE_SV

Get the value from slot po in the base (DEPTH=1) pad of a padlist

    SV *  PAD_BASE_SV(PADLIST padlist, PADOFFSET po)
PAD_CLONE_VARS

Clone the state variables associated with running and compiling pads.

    void  PAD_CLONE_VARS(PerlInterpreter *proto_perl,
                         CLONE_PARAMS* param)
PAD_COMPNAME_FLAGS

Return the flags for the current compiling pad name at offset po. Assumes a valid slot entry.

    U32  PAD_COMPNAME_FLAGS(PADOFFSET po)
PAD_COMPNAME_GEN

The generation number of the name at offset po in the current compiling pad (lvalue).

    STRLEN  PAD_COMPNAME_GEN(PADOFFSET po)
PAD_COMPNAME_GEN_set

Sets the generation number of the name at offset po in the current ling pad (lvalue) to gen.

    STRLEN  PAD_COMPNAME_GEN_set(PADOFFSET po, int gen)
PAD_COMPNAME_OURSTASH

Return the stash associated with an our variable. Assumes the slot entry is a valid our lexical.

    HV *  PAD_COMPNAME_OURSTASH(PADOFFSET po)
PAD_COMPNAME_PV

Return the name of the current compiling pad name at offset po. Assumes a valid slot entry.

    char *  PAD_COMPNAME_PV(PADOFFSET po)
PAD_COMPNAME_TYPE

Return the type (stash) of the current compiling pad name at offset po. Must be a valid name. Returns null if not typed.

    HV *  PAD_COMPNAME_TYPE(PADOFFSET po)
PadnameIsOUR

Whether this is an "our" variable.

    bool  PadnameIsOUR(PADNAME * pn)
PadnameIsSTATE

Whether this is a "state" variable.

    bool  PadnameIsSTATE(PADNAME * pn)
PadnameOURSTASH

The stash in which this "our" variable was declared.

    HV *  PadnameOURSTASH(PADNAME * pn)
PadnameOUTER

Whether this entry belongs to an outer pad. Entries for which this is true are often referred to as 'fake'.

    bool  PadnameOUTER(PADNAME * pn)
PadnameTYPE

The stash associated with a typed lexical. This returns the %Foo:: hash for my Foo $bar.

    HV *  PadnameTYPE(PADNAME * pn)
PAD_RESTORE_LOCAL

Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()

    void  PAD_RESTORE_LOCAL(PAD *opad)
PAD_SAVE_LOCAL

Save the current pad to the local variable opad, then make the current pad equal to npad

    void  PAD_SAVE_LOCAL(PAD *opad, PAD *npad)
PAD_SAVE_SETNULLPAD

Save the current pad then set it to null.

    void  PAD_SAVE_SETNULLPAD()
PAD_SETSV

Set the slot at offset po in the current pad to sv

    SV *  PAD_SETSV(PADOFFSET po, SV* sv)
PAD_SET_CUR

Set the current pad to be pad n 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);
    void  PAD_SET_CUR(PADLIST padlist, I32 n)
PAD_SET_CUR_NOSAVE

like PAD_SET_CUR, but without the save

    void  PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)
PAD_SV

Get the value at offset po in the current pad

    SV *  PAD_SV(PADOFFSET po)
PAD_SVl

Lightweight and lvalue version of PAD_SV. Get or set the value at offset po in the current pad. Unlike PAD_SV, does not print diagnostics with -DX. For internal use only.

    SV *  PAD_SVl(PADOFFSET po)
SAVECLEARSV

Clear the pointed to pad value on scope exit. (i.e. the runtime action of my)

    void  SAVECLEARSV(SV **svp)
SAVECOMPPAD

save PL_comppad and PL_curpad

    void  SAVECOMPPAD()
SAVEPADSV

Save a pad slot (used to restore after an iteration)

    void  SAVEPADSV(PADOFFSET po)

Password and Group access

There are only public API items currently in Password and Group access

Paths to system commands

There are only public API items currently in Paths to system commands

Prototype information

There are only public API items currently in Prototype information

REGEXP Functions

There are only public API items currently in REGEXP Functions

Signals

There are only public API items currently in Signals

Site configuration

There are only public API items currently in Site configuration

Sockets configuration values

There are only public API items currently in Sockets configuration values

Source Filters

There are only public API items currently in Source Filters

Stack Manipulation Macros

djSP

Declare Just SP. This is actually identical to dSP, and declares a local copy of perl's stack pointer, available via the SP macro. See "SP" in perlapi. (Available for backward source code compatibility with the old (Perl 5.005) thread model.)

    djSP();
LVRET

True if this op will be the return value of an lvalue subroutine

String Handling

delimcpy_no_escape

Copy a source buffer to a destination buffer, stopping at (but not including) the first occurrence in the source of the delimiter byte, delim. The source is the bytes between from and from_end - 1. Similarly, the dest is to up to to_end.

The number of bytes copied is written to *retlen.

Returns the position of delim in the from buffer, but if there is no such occurrence before from_end, then from_end is returned, and the entire buffer from .. from_end - 1 is copied.

If there is room in the destination available after the copy, an extra terminating safety NUL byte is appended (not included in the returned length).

The error case is if the destination buffer is not large enough to accommodate everything that should be copied. In this situation, a value larger than to_end - to is written to *retlen, and as much of the source as fits will be written to the destination. Not having room for the safety NUL is not considered an error.

    char*  delimcpy_no_escape(char* to, const char* to_end,
                              const char* from, const char* from_end,
                              const int delim, I32* retlen)
quadmath_format_needed

quadmath_format_needed() returns true if the format string seems to contain at least one non-Q-prefixed %[efgaEFGA] format specifier, or returns false otherwise.

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

quadmath_snprintf() is very strict about its format string and will fail, returning -1, if the format is invalid. It accepts exactly one format spec.

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)

SV Flags

SVt_INVLIST

Type flag for scalars. See "svtype" in perlapi.

SV Handling

PL_Sv

A scratch pad SV for whatever temporary use you need. Chiefly used as a fallback by macros on platforms where "PERL_USE_GCC_BRACE_GROUPS" in perlapi> is unavailable, and which would otherwise would evaluate their SV parameter more than once.

    PL_Sv
sv_2bool

This macro is only used by sv_true() or its macro equivalent, and only if the latter's argument is neither SvPOK, SvIOK nor SvNOK. It calls sv_2bool_flags with the SV_GMAGIC flag.

    bool  sv_2bool(SV *const sv)
sv_2bool_flags

This function is only used by sv_true() and friends, and only if the latter's argument is neither SvPOK, SvIOK nor SvNOK. If the flags contain SV_GMAGIC, then it does an mg_get() first.

    bool  sv_2bool_flags(SV *sv, I32 flags)
sv_2num

NOTE: sv_2num 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)
sv_2pvbyte_nolen

Return a pointer to the byte-encoded representation of the SV. May cause the SV to be downgraded from UTF-8 as a side-effect.

Usually accessed via the SvPVbyte_nolen macro.

    char*  sv_2pvbyte_nolen(SV* sv)
sv_2pvutf8_nolen

Return a pointer to the UTF-8-encoded representation of the SV. May cause the SV to be upgraded to UTF-8 as a side-effect.

Usually accessed via the SvPVutf8_nolen macro.

    char*  sv_2pvutf8_nolen(SV* sv)
sv_2pv_flags

Returns a pointer to the string value of an SV, and sets *lp to its length. If flags has the SV_GMAGIC bit set, does an mg_get() first. Coerces sv to a string if necessary. Normally invoked via the SvPV_flags macro. sv_2pv() and sv_2pv_nomg usually end up here too.

    char*  sv_2pv_flags(SV *const sv, STRLEN *const lp,
                        const U32 flags)
sv_2pv_nolen

Like sv_2pv(), but doesn't return the length too. You should usually use the macro wrapper SvPV_nolen(sv) instead.

    char*  sv_2pv_nolen(SV* sv)
sv_add_arena

Given a chunk of memory, link it to the head of the list of arenas, and split it into a list of free SVs.

    void  sv_add_arena(char *const ptr, const U32 size,
                       const U32 flags)
sv_clean_all

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.

    I32  sv_clean_all()
sv_clean_objs

Attempt to destroy all objects not yet freed.

    void  sv_clean_objs()
sv_free_arenas

Deallocate the memory used by all arenas. Note that all the individual SV heads and bodies within the arenas must already have been freed.

    void  sv_free_arenas()
sv_grow

Expands the character buffer in the SV. If necessary, uses sv_unref and upgrades the SV to SVt_PV. Returns a pointer to the character buffer. Use the SvGROW wrapper instead.

    char*  sv_grow(SV *const sv, STRLEN newlen)
sv_iv

DEPRECATED! It is planned to remove sv_iv from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvIVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    IV  sv_iv(SV* sv)
sv_newref

Increment an SV's reference count. Use the SvREFCNT_inc() wrapper instead.

    SV*  sv_newref(SV *const sv)
sv_nv

DEPRECATED! It is planned to remove sv_nv from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvNVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    NV  sv_nv(SV* sv)
sv_pv

Use the SvPV_nolen macro instead

    char*  sv_pv(SV *sv)
sv_pvbyte

Use SvPVbyte_nolen instead.

    char*  sv_pvbyte(SV *sv)
sv_pvbyten

DEPRECATED! It is planned to remove sv_pvbyten from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvPVbyte macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    char*  sv_pvbyten(SV *sv, STRLEN *lp)
sv_pvbyten_force

The backend for the SvPVbytex_force macro. Always use the macro instead. If the SV cannot be downgraded from UTF-8, this croaks.

    char*  sv_pvbyten_force(SV *const sv, STRLEN *const lp)
sv_pvn

DEPRECATED! It is planned to remove sv_pvn from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvPV macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    char*  sv_pvn(SV *sv, STRLEN *lp)
sv_pvn_force

Get a sensible string out of the SV somehow. A private implementation of the SvPV_force macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    char*  sv_pvn_force(SV* sv, STRLEN* lp)
sv_pvutf8

Use the SvPVutf8_nolen macro instead

    char*  sv_pvutf8(SV *sv)
sv_pvutf8n

DEPRECATED! It is planned to remove sv_pvutf8n from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvPVutf8 macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    char*  sv_pvutf8n(SV *sv, STRLEN *lp)
sv_pvutf8n_force

The backend for the SvPVutf8x_force macro. Always use the macro instead.

    char*  sv_pvutf8n_force(SV *const sv, STRLEN *const lp)
sv_taint

Taint an SV. Use SvTAINTED_on instead.

    void  sv_taint(SV* sv)
sv_tainted

Test an SV for taintedness. Use SvTAINTED instead.

    bool  sv_tainted(SV *const sv)
SvTHINKFIRST

A quick flag check to see whether an sv should be passed to sv_force_normal to be "downgraded" before SvIVX or SvPVX can be modified directly.

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)
sv_true

Returns true if the SV has a true value by Perl's rules. Use the SvTRUE macro instead, which may call sv_true() or may instead use an in-line version.

    I32  sv_true(SV *const sv)
sv_untaint

Untaint an SV. Use SvTAINTED_off instead.

    void  sv_untaint(SV *const sv)
sv_uv

DEPRECATED! It is planned to remove sv_uv from a future release of Perl. Do not use it for new code; remove it from existing code.

A private implementation of the SvUVx macro for compilers which can't cope with complex macro expressions. Always use the macro instead.

    UV  sv_uv(SV* sv)

Time

There are only public API items currently in Time

Typedef names

There are only public API items currently in Typedef names

Unicode Support

bytes_from_utf8_loc

NOTE: bytes_from_utf8_loc is experimental and may change or be removed without notice.

Like "bytes_from_utf8" in perlapi(), but takes an extra parameter, a pointer to where to store the location of the first character in "s" that cannot be converted to non-UTF8.

If that parameter is NULL, this function behaves identically to bytes_from_utf8.

Otherwise if *is_utf8p is 0 on input, the function behaves identically to bytes_from_utf8, except it also sets *first_non_downgradable to NULL.

Otherwise, the function returns a newly created NUL-terminated string containing the non-UTF8 equivalent of the convertible first portion of "s". *lenp is set to its length, not including the terminating NUL. If the entire input string was converted, *is_utf8p is set to a FALSE value, and *first_non_downgradable is set to NULL.

Otherwise, *first_non_downgradable is set to point to the first byte of the first character in the original string that wasn't converted. *is_utf8p is unchanged. Note that the new string may have length 0.

Another way to look at it is, if *first_non_downgradable is non-NULL and *is_utf8p is TRUE, this function starts at the beginning of "s" and converts as many characters in it as possible stopping at the first one it finds that can't be converted to non-UTF-8. *first_non_downgradable is set to point to that. The function returns the portion that could be converted in a newly created NUL-terminated string, and *lenp is set to its length, not including the terminating NUL. If the very first character in the original could not be converted, *lenp will be 0, and the new string will contain just a single NUL. If the entire input string was converted, *is_utf8p is set to FALSE and *first_non_downgradable is set to NULL.

Upon successful return, the number of variants in the converted portion of the string can be computed by having saved the value of *lenp before the call, and subtracting the after-call value of *lenp from it.

    U8*  bytes_from_utf8_loc(const U8 *s, STRLEN *lenp,
                             bool *is_utf8p,
                             const U8 ** first_unconverted)
find_uninit_var

NOTE: find_uninit_var 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 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)
isSCRIPT_RUN

Returns a bool as to whether or not the sequence of bytes from s up to but not including send form a "script run". utf8_target is TRUE iff the sequence starting at s is to be treated as UTF-8. To be precise, except for two degenerate cases given below, this function returns TRUE iff all code points in it come from any combination of three "scripts" given by the Unicode "Script Extensions" property: Common, Inherited, and possibly one other. Additionally all decimal digits must come from the same consecutive sequence of 10.

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)
is_utf8_non_invariant_string

Returns TRUE if "is_utf8_invariant_string" in perlapi returns FALSE for the first len bytes of the string s, but they are, nonetheless, legal Perl-extended UTF-8; otherwise returns FALSE.

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)
report_uninit

Print appropriate "Use of uninitialized variable" warning.

    void  report_uninit(const SV *uninit_sv)
utf8n_to_uvuni

DEPRECATED! It is planned to remove utf8n_to_uvuni from a future release of Perl. Do not use it for new code; remove it from existing code.

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)
utf8_to_uvuni

DEPRECATED! It is planned to remove utf8_to_uvuni from a future release of Perl. Do not use it for new code; remove it from existing code.

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)
utf8_to_uvuni_buf

DEPRECATED! It is planned to remove utf8_to_uvuni_buf from a future release of Perl. Do not use it for new code; remove it from existing code.

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)
uvoffuni_to_utf8_flags

THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Instead, Almost all code should use "uvchr_to_utf8" in perlapi or "uvchr_to_utf8_flags" in perlapi.

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)
uvuni_to_utf8_flags

DEPRECATED! It is planned to remove uvuni_to_utf8_flags from a future release of Perl. Do not use it for new code; remove it from existing code.

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)
valid_utf8_to_uvchr

Like "utf8_to_uvchr_buf" in perlapi, but should only be called when it is known that the next character in the input UTF-8 string s is well-formed (e.g., it passes "isUTF8_CHAR" in perlapi. Surrogates, non-character code points, and non-Unicode code points are allowed.

    UV  valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
variant_under_utf8_count

This function looks at the sequence of bytes between s and e, which are assumed to be encoded in ASCII/Latin1, and returns how many of them would change should the string be translated into UTF-8. Due to the nature of UTF-8, each of these would occupy two bytes instead of the single one in the input string. Thus, this function returns the precise number of bytes the string would expand by when translated to UTF-8.

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)

Utility Functions

There are only public API items currently in Utility Functions

Versioning

There are only public API items currently in Versioning

Warning and Dieing

PL_dowarn

The C variable that roughly corresponds to Perl's $^W warning variable. However, $^W is treated as a boolean, whereas PL_dowarn is a collection of flag bits.

On threaded perls, each thread has an independent copy of this variable; each initialized at creation time with the current value of the creating thread's copy.

    U8  PL_dowarn

XS

There are only public API items currently in XS

Undocumented elements

The following functions are currently undocumented. If you use one of them, you may wish to consider creating and submitting documentation for it.

AUTHORS

The autodocumentation system was originally added to the Perl core by Benjamin Stuhl. Documentation is by whoever was kind enough to document their functions.

SEE ALSO

config.h, perlapi, perlapio, perlcall, perlclib, perlfilter, perlguts, perlinterp, perliol, perlmroapi, perlreguts, perlxs