-*- mode: Pod; buffer-read-only: t -*-
!!!!!!!   DO NOT EDIT THIS FILE   !!!!!!!
This file is built by autodoc.pl extracting documentation from the C source
files.
Any changes made here will be lost!

=head1 NAME

perlintern - autogenerated documentation of purely B<internal>
Perl functions

=head1 DESCRIPTION
X<internal Perl functions> X<interpreter functions>

This file is the autogenerated documentation of functions in the
Perl interpreter that are documented using Perl's internal documentation
format but are not marked as part of the Perl API.  In other words,
B<they are not for use in extensions>!

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



=head1 AV Handling

=over 4

=item C<av_fetch_simple>
X<av_fetch_simple>

This is a cut-down version of av_fetch that assumes that the array is
very straightforward - no magic, not readonly, and AvREAL - and that
C<key> is not negative. This function MUST NOT be used in situations
where any of those assumptions may not hold.

Returns the SV at the specified index in the array.  The C<key> is the
index.  If lval is true, you are guaranteed to get a real SV back (in case
it wasn't real before), which you can then modify.  Check that the return
value is non-null before dereferencing it to a C<SV*>.

The rough perl equivalent is C<$myarray[$key]>.

=over 3

 SV **       av_fetch_simple(      AV *av, SSize_t key, I32 lval)
 SV **  Perl_av_fetch_simple(pTHX_ AV *av, SSize_t key, I32 lval)

=back

=back

=for hackers
Declared at embed.fnc, line 916; documented at inline.h, line 124

=over 4

=item C<av_new_alloc>
X<av_new_alloc>

This implements L<perlapi/C<newAV_alloc_x>>
and L<perlapi/C<newAV_alloc_xz>>, which are the public API for this
functionality.

Creates a new AV and allocates its SV* array.

This is similar to, but more efficient than doing:

    AV *av = newAV();
    av_extend(av, key);

The size parameter is used to pre-allocate a SV* array large enough to
hold at least elements C<0..(size-1)>.  C<size> must be at least 1.

The C<zeroflag> parameter controls whether or not the array is NULL
initialized.

=over 3

 AV *       av_new_alloc(SSize_t size,
                          bool zeroflag                          )
 AV *  Perl_av_new_alloc(pTHX_ SSize_t size,
                          bool zeroflag                          )

=back

=back

=for hackers
Declared at embed.fnc, line 926; documented at inline.h, line 170

=over 4

=item C<av_store_simple>
X<av_store_simple>

This is a cut-down version of av_store that assumes that the array is
very straightforward - no magic, not readonly, and AvREAL - and that
C<key> is not negative. This function MUST NOT be used in situations
where any of those assumptions may not hold.

Stores an SV in an array.  The array index is specified as C<key>. It
can be dereferenced to get the C<SV*> that was stored there (= C<val>)).

Note that the caller is responsible for suitably incrementing the reference
count of C<val> before the call.

Approximate Perl equivalent: C<splice(@myarray, $key, 1, $val)>.

=over 3

 SV **       av_store_simple(      AV *av, SSize_t key, SV *val)
 SV **  Perl_av_store_simple(pTHX_ AV *av, SSize_t key, SV *val)

=back

=back

=for hackers
Declared at embed.fnc, line 944; documented at inline.h, line 78

=over 4

=item C<AvFILLp>
X<AvFILLp>

If the array C<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
C<av>.  It does not handle magic, hence the C<p> private indication in its name.

=over 3

 SSize_t  AvFILLp(AV* av)

=back

=back

=for hackers
Declared and documented at av.h, line 74

=head1 Callback Functions
X<SAVEf_KEEPOLDELEM>X<SAVEf_SETMAGIC>

=over 4

=item C<dowantarray>
X<dowantarray>

C<B<DEPRECATED!>>  It is planned to remove C<dowantarray>
from a future release of Perl.  Do not use it for
new code; remove it from existing code.

Implements the deprecated L<perlapi/C<GIMME>>.

=over 3

 U8       dowantarray()
 U8  Perl_dowantarray(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 1347; documented at pp_ctl.c, line 1634

=over 4

=item C<leave_scope>
X<leave_scope>

Implements C<LEAVE_SCOPE> which you should use instead.

=over 3

 void       leave_scope(      I32 base)
 void  Perl_leave_scope(pTHX_ I32 base)

=back

=back

=for hackers
Declared at embed.fnc, line 2002; documented at scope.c, line 1176

=over 4

=item C<magic_freedestruct>
X<magic_freedestruct>

This function is called via magic to implement the
C<mortal_destructor_sv()> and C<mortal_destructor_x()> functions. It
should not be called directly and has no user serviceable parts.

=over 3

 int       magic_freedestruct(      SV *sv, MAGIC *mg)
 int  Perl_magic_freedestruct(pTHX_ SV *sv, MAGIC *mg)

=back

=back

=for hackers
Declared at embed.fnc, line 2087; documented at scope.c, line 2041

=over 4

=item C<mortal_svfunc_x>

=item C<MORTALSVFUNC_X>
X<mortal_svfunc_x>X<MORTALSVFUNC_X>

These are synonymous.

They each arrange for a C function reference to be called at the
B<end of the current statement> with the arguments provided. It is a
wrapper around C<mortal_destructor_sv()> which ensures that the latter
function is called appropriately.

Be aware that there is a significant difference in timing between the
I<end of the current statement> and the I<end of the current pseudo
block>. If you are looking for a mechanism to trigger a function at the
end of the B<current pseudo block> you should look at
L<perlapi/C<SAVEDESTRUCTOR_X>> instead of this function.

=over 3

 void       mortal_svfunc_x(      SVFUNC_t f, SV *p)
 void  Perl_mortal_svfunc_x(pTHX_ SVFUNC_t f, SV *p)
 void       MORTALSVFUNC_X (      SVFUNC_t f, SV *p)

=back

=back

=for hackers
mortal_svfunc_x declared at embed.fnc, line 2263; all in group documented at scope.c, line 2025
MORTALSVFUNC_X declared at scope.c, line 2026

=over 4

=item C<pop_scope>
X<pop_scope>

Implements L<perlapi/C<LEAVE>>

=over 3

 void       pop_scope()
 void  Perl_pop_scope(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2813; documented at scope.c, line 160

=over 4

=item C<push_scope>
X<push_scope>

Implements L<perlapi/C<ENTER>>

=over 3

 void       push_scope()
 void  Perl_push_scope(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2847; documented at scope.c, line 131

=over 4

=item C<save_adelete>
X<save_adelete>

Implements C<SAVEADELETE>.

=over 3

 void       save_adelete(      AV *av, SSize_t key)
 void  Perl_save_adelete(pTHX_ AV *av, SSize_t key)

=back

=back

=for hackers
Declared at embed.fnc, line 3127; documented at scope.c, line 918

=over 4

=item C<save_freercpv>
X<save_freercpv>

Implements C<SAVEFREERCPV>.

Saves and frees a refcounted string. Calls rcpv_free()
on the argument when the current pseudo block is finished.

=over 3

 void       save_freercpv(      char *rcpv)
 void  Perl_save_freercpv(pTHX_ char *rcpv)

=back

=back

=for hackers
Declared at embed.fnc, line 3154; documented at scope.c, line 409

=over 4

=item C<save_generic_pvref>
X<save_generic_pvref>

Implements C<SAVEGENERICPV>.

Like save_pptr(), but also Safefree()s the new value if it is different
from the old one.  Can be used to restore a global char* to its prior
contents, freeing new value.

=over 3

 void       save_generic_pvref(      char **str)
 void  Perl_save_generic_pvref(pTHX_ char **str)

=back

=back

=for hackers
Declared at embed.fnc, line 3156; documented at scope.c, line 428

=over 4

=item C<save_generic_svref>
X<save_generic_svref>

Implements C<SAVEGENERICSV>.

Like save_sptr(), but also SvREFCNT_dec()s the new value.  Can be used to
restore a global SV to its prior contents, freeing new value.

=over 3

 void       save_generic_svref(      SV **sptr)
 void  Perl_save_generic_svref(pTHX_ SV **sptr)

=back

=back

=for hackers
Declared at embed.fnc, line 3158; documented at scope.c, line 369

=over 4

=item C<save_hdelete>
X<save_hdelete>

Implements C<SAVEHDELETE>.

=over 3

 void       save_hdelete(      HV *hv, SV *keysv)
 void  Perl_save_hdelete(pTHX_ HV *hv, SV *keysv)

=back

=back

=for hackers
Declared at embed.fnc, line 3163; documented at scope.c, line 894

=over 4

=item C<save_hints>
X<save_hints>

Implements C<SAVEHINTS>.

=over 3

 void       save_hints()
 void  Perl_save_hints(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3173; documented at scope.c, line 967

=over 4

=item C<save_op>
X<save_op>

Implements C<SAVEOP>.

=over 3

 void       save_op()
 void  Perl_save_op(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3184; documented at scope.h, line 316

=over 4

=item C<save_padsv>
X<save_padsv>

Saves the value in the pad at the given index to be restored on scope exit.
Before this value is restored back in, whatever is currently there has its
reference count decremented by one.

=over 3

 void       save_padsv(      PADOFFSET padix)
 void  Perl_save_padsv(pTHX_ PADOFFSET padix)

=back

=back

=for hackers
Declared at embed.fnc, line 3185; documented at scope.c, line 856

=over 4

=item C<save_padsv_and_mortalize>
X<save_padsv_and_mortalize>

Implements C<SAVEPADSVANDMORTALIZE>.

=over 3

 void       save_padsv_and_mortalize(      PADOFFSET off)
 void  Perl_save_padsv_and_mortalize(pTHX_ PADOFFSET off)

=back

=back

=for hackers
Declared at embed.fnc, line 3186; documented at scope.c, line 761

=over 4

=item C<save_pushptr>
X<save_pushptr>

The refcnt of object C<ptr> will be decremented at the end of the current
I<pseudo-block>.  C<type> gives the type of C<ptr>, expressed as one of the
constants in F<scope.h> whose name begins with C<SAVEt_>.

This is the underlying implementation of several macros, like
C<SAVEFREESV>.

=over 3

 void       save_pushptr(      void * const ptr, const int type)
 void  Perl_save_pushptr(pTHX_ void * const ptr, const int type)

=back

=back

=for hackers
Declared at embed.fnc, line 3192; documented at scope.c, line 801

=over 4

=item C<save_rcpv>
X<save_rcpv>

Implements C<SAVERCPV>.

Saves and restores a refcounted string, similar to what
save_generic_svref would do for a SV*. Can be used to restore
a refcounted string to its previous state. Performs the 
appropriate refcount counting so that nothing should leak
or be prematurely freed.

=over 3

 void       save_rcpv(      char **prcpv)
 void  Perl_save_rcpv(pTHX_ char **prcpv)

=back

=back

=for hackers
Declared at embed.fnc, line 3201; documented at scope.c, line 389

=over 4

=item C<save_scalar_at>
X<save_scalar_at>

A helper function for localizing the SV referenced by C<*sptr>.

If C<SAVEf_KEEPOLDELEM> is set in in C<flags>, the function returns the input
scalar untouched.

Otherwise it replaces C<*sptr> with a new C<undef> scalar, and returns that.
The new scalar will have the old one's magic (if any) copied to it.
If there is such magic, and C<SAVEf_SETMAGIC> is set in in C<flags>, 'set'
magic will be processed on the new scalar.  If unset, 'set' magic will be
skipped.  The latter typically means that assignment will soon follow (I<e.g.>,
S<C<'local $x = $y'>>), and that will handle the magic.

=over 3

 SV *  save_scalar_at(SV **sptr, const U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 6148; documented at scope.c, line 300

=over 4

=item C<save_set_svflags>
X<save_set_svflags>

Implements C<SAVESETSVFLAGS>.

Set the SvFLAGS specified by mask to the values in val

=over 3

 void       save_set_svflags(      SV *sv, U32 mask, U32 val)
 void  Perl_save_set_svflags(pTHX_ SV *sv, U32 mask, U32 val)

=back

=back

=for hackers
Declared at embed.fnc, line 3204; documented at scope.c, line 471

=over 4

=item C<save_shared_pvref>
X<save_shared_pvref>

Implements C<SAVESHAREDPV>.

Like save_generic_pvref(), but uses PerlMemShared_free() rather than Safefree().
Can be used to restore a shared global char* to its prior
contents, freeing new value.

=over 3

 void       save_shared_pvref(      char **str)
 void  Perl_save_shared_pvref(pTHX_ char **str)

=back

=back

=for hackers
Declared at embed.fnc, line 3213; documented at scope.c, line 449

=over 4

=item C<save_vptr>
X<save_vptr>

Implements C<SAVEVPTR>.

=over 3

 void       save_vptr(      void *ptr)
 void  Perl_save_vptr(pTHX_ void *ptr)

=back

=back

=for hackers
Declared at embed.fnc, line 3224; documented at scope.c, line 736

=head1 Casting
X<NUM2PTR>

There are currently no internal API items in Casting

=head1 Character case changing

There are currently no internal API items in Character case changing

=head1 Character classification


This section is about functions (really macros) that classify characters
into types, such as punctuation versus alphabetic, etc.  Most of these are
analogous to regular expression character classes.  (See
L<perlrecharclass/POSIX Character Classes>.)  There are several variants for
each class.  (Not all macros have all variants; each item below lists the
ones valid for it.)  None are affected by C<use bytes>, and only the ones
with C<LC> in the name are affected by the current locale.

The base function, e.g., C<isALPHA()>, takes any signed or unsigned value,
treating it as a code point, and returns a boolean as to whether or not the
character represented by it is (or on non-ASCII platforms, corresponds to) an
ASCII character in the named class based on platform, Unicode, and Perl rules.
If the input is a number that doesn't fit in an octet, FALSE is returned.

Variant C<isI<FOO>_A> (e.g., C<isALPHA_A()>) is identical to the base function
with no suffix C<"_A">.  This variant is used to emphasize by its name that
only ASCII-range characters can return TRUE.

Variant C<isI<FOO>_L1> imposes the Latin-1 (or EBCDIC equivalent) character set
onto the platform.  That is, the code points that are ASCII are unaffected,
since ASCII is a subset of Latin-1.  But the non-ASCII code points are treated
as if they are Latin-1 characters.  For example, C<isWORDCHAR_L1()> will return
true when called with the code point 0xDF, which is a word character in both
ASCII and EBCDIC (though it represents different characters in each).
If the input is a number that doesn't fit in an octet, FALSE is returned.
(Perl's documentation uses a colloquial definition of Latin-1, to include all
code points below 256.)

Variant C<isI<FOO>_uvchr> is exactly like the C<isI<FOO>_L1> variant, for
inputs below 256, but if the code point is larger than 255, Unicode rules are
used to determine if it is in the character class.  For example,
C<isWORDCHAR_uvchr(0x100)> returns TRUE, since 0x100 is LATIN CAPITAL LETTER A
WITH MACRON in Unicode, and is a word character.

Variants C<isI<FOO>_utf8> and C<isI<FOO>_utf8_safe> are like C<isI<FOO>_uvchr>,
but are used for UTF-8 encoded strings.  The two forms are different names for
the same thing.  Each call to one of these classifies the first character of
the string starting at C<p>.  The second parameter, C<e>, points to anywhere in
the string beyond the first character, up to one byte past the end of the
entire string.  Although both variants are identical, the suffix C<_safe> in
one name emphasizes that it will not attempt to read beyond S<C<e - 1>>,
provided that the constraint S<C<s E<lt> e>> is true (this is asserted for in
C<-DDEBUGGING> builds).  If the UTF-8 for the input character is malformed in
some way, the program may croak, or the function may return FALSE, at the
discretion of the implementation, and subject to change in future releases.

Variant C<isI<FOO>_LC> is like the C<isI<FOO>_A> and C<isI<FOO>_L1> variants,
but the result is based on the current locale, which is what C<LC> in the name
stands for.  If Perl can determine that the current locale is a UTF-8 locale,
it uses the published Unicode rules; otherwise, it uses the C library function
that gives the named classification.  For example, C<isDIGIT_LC()> when not in
a UTF-8 locale returns the result of calling C<isdigit()>.  FALSE is always
returned if the input won't fit into an octet.  On some platforms where the C
library function is known to be defective, Perl changes its result to follow
the POSIX standard's rules.

Variant C<isI<FOO>_LC_uvchr> acts exactly like C<isI<FOO>_LC> for inputs less
than 256, but for larger ones it returns the Unicode classification of the code
point.

Variants C<isI<FOO>_LC_utf8> and C<isI<FOO>_LC_utf8_safe> are like
C<isI<FOO>_LC_uvchr>, but are used for UTF-8 encoded strings.  The two forms
are different names for the same thing.  Each call to one of these classifies
the first character of the string starting at C<p>.  The second parameter,
C<e>, points to anywhere in the string beyond the first character, up to one
byte past the end of the entire string.  Although both variants are identical,
the suffix C<_safe> in one name emphasizes that it will not attempt to read
beyond S<C<e - 1>>, provided that the constraint S<C<s E<lt> e>> is true (this
is asserted for in C<-DDEBUGGING> builds).  If the UTF-8 for the input
character is malformed in some way, the program may croak, or the function may
return FALSE, at the discretion of the implementation, and subject to change in
future releases.


=over 4

=item C<CC_mask_>
X<CC_mask_>

This translates C<classnum> into a bit pattern to use in conjunction with
entries in C<PL_charclass[]>, and operations such is C<L</Perl_isCC_by_bit>>.
C<classnum> is one of the classes defined in F<handy.h> for this purpose.

=over 3

 U32  CC_mask_(U8 c, U8 classnum)

=back

=back

=for hackers
Declared and documented at handy.h, line 1640

=over 4

=item C<Perl_isCC_by_bit>
X<Perl_isCC_by_bit>

Returns a boolean as to whether or not the character C<c> in the Latin1 range
is a member of the class(es) given by C<bit_pattern>, as formed by
C<L</CC_mask_>>.

=over 3

 bool  Perl_isCC_by_bit(U8 c, U32 bit_pattern)

=back

=back

=for hackers
Declared and documented at handy.h, line 1646

=head1 Compiler and Preprocessor information

There are currently no internal API items in Compiler and Preprocessor information

=head1 Compiler directives

=over 4

=item C<PREVENT_LVALUE>
X<PREVENT_LVALUE>

This returns its input C<x>, but forces a compilation error if called from an
lvalue context.  Its main use is to be placed in a macro that otherwise could 
be used to change the value of C<x>, but doing so is undesirable.

A common example is when there are getter and setter macros for C<x>, and the
setter has error checking that shouldn't be short circuited.  Wrapping C<x>
with this macro in the getter call forces the setter one to be used to change
C<x>.

=over 3

 bool  PREVENT_LVALUE(x)

=back

=back

=for hackers
Declared and documented at handy.h, line 1444

=head1 Compile-time scope hooks

=over 4

=item C<BhkENTRY>
X<BhkENTRY>

NOTE: C<BhkENTRY> is B<experimental> and may change or be
removed without notice.

Return an entry from the BHK structure.  C<which> is a preprocessor token
indicating which entry to return.  If the appropriate flag is not set
this will return C<NULL>.  The type of the return value depends on which
entry you ask for.

=over 3

 void *  BhkENTRY(BHK *hk, token which)

=back

=back

=for hackers
Declared and documented at op.h, line 805

=over 4

=item C<BhkFLAGS>
X<BhkFLAGS>

NOTE: C<BhkFLAGS> is B<experimental> and may change or be
removed without notice.

Return the BHK's flags.

=over 3

 U32  BhkFLAGS(BHK *hk)

=back

=back

=for hackers
Declared and documented at op.h, line 802

=over 4

=item C<CALL_BLOCK_HOOKS>
X<CALL_BLOCK_HOOKS>

NOTE: C<CALL_BLOCK_HOOKS> is B<experimental> and may change or be
removed without notice.

Call all the registered block hooks for type C<which>.  C<which> is a
preprocessing token; the type of C<arg> depends on C<which>.

=over 3

 void  CALL_BLOCK_HOOKS(token which, arg)

=back

=back

=for hackers
Declared and documented at op.h, line 827

=head1 Concurrency

=over 4

=item C<CVf_SLABBED>

=item C<CvROOT>

=item C<CvSTART>

=item C<CX_CUR>

=item C<CX_LEAVE_SCOPE>

=item C<CX_POP>

=item C<cx_type>

=item C<CXt_BLOCK>

=item C<CXt_EVAL>

=item C<CXt_FORMAT>

=item C<CXt_GIVEN>

=item C<CXt_LOOP_ARY>

=item C<CXt_LOOP_LAZYIV>

=item C<CXt_LOOP_LAZYSV>

=item C<CXt_LOOP_LIST>

=item C<CXt_LOOP_PLAIN>

=item C<CXt_NULL>

=item C<CXt_SUB>

=item C<CXt_SUBST>

=item C<CXt_WHEN>

=item C<CXINC>

=item C<cxstack>

=item C<cxstack_ix>

=item C<CXt_BLOCK*>

=item C<CXt_EVAL*>

=item C<CXt_FORMAT*>

=item C<CXt_GIVEN*>

=item C<CXt_LOOP_ARY*>

=item C<CXt_LOOP_LAZYIV*>

=item C<CXt_LOOP_LAZYSV*>

=item C<CXt_LOOP_LIST*>

=item C<CXt_LOOP_PLAIN*>

=item C<CXt_NULL*>

=item C<CXt_SUB*>

=item C<CXt_SUBST*>

=item C<CXt_WHEN*>

=item C<dounwind>

Described in L<perlguts>.

=over 3

 OP *                 CvROOT        (      CV * sv)
 OP *                 CvSTART       (      CV * sv)
                      CX_CUR        ()
 void                 CX_LEAVE_SCOPE(      PERL_CONTEXT* cx)
 void                 CX_POP        (      PERL_CONTEXT* cx)
 PERL_CONTEXT *       cxstack
 I32                  cxstack_ix
 void                 dounwind      (      I32 cxix)
 void            Perl_dounwind      (pTHX_ I32 cxix)

=back

=back

=for hackers
CVf_SLABBED all in group documented at pod/perlguts.pod, line 5257
CvROOT 
CvSTART 
CX_CUR 
CX_LEAVE_SCOPE 
CX_POP 
cx_type 
CXt_BLOCK 
CXt_EVAL 
CXt_FORMAT 
CXt_GIVEN 
CXt_LOOP_ARY 
CXt_LOOP_LAZYIV 
CXt_LOOP_LAZYSV 
CXt_LOOP_LIST 
CXt_LOOP_PLAIN 
CXt_NULL 
CXt_SUB 
CXt_SUBST 
CXt_WHEN 
CXINC 
cxstack 
cxstack_ix 
dounwind declared at embed.fnc, line 1335

=over 4

=item C<my_fork>
X<my_fork>

This is for the use of C<PerlProc_fork> as a wrapper for the C library
L<fork(2)> on some platforms to hide some platform quirks.  It should not be
used except through C<PerlProc_fork>.

=over 3

 Pid_t       my_fork()
 Pid_t  Perl_my_fork()

=back

=back

=for hackers
Declared at embed.fnc, line 2315; documented at util.c, line 2819

=over 4

=item C<PERL_CONTEXT>

Described in L<perlguts>.

=back

=for hackers
Documented at pod/perlguts.pod, line 4341

=head1 COPs and Hint Hashes

There are currently no internal API items in COPs and Hint Hashes

=head1 Custom Operators

=over 4

=item C<core_prototype>
X<core_prototype>

This function assigns the prototype of the named core function to C<sv>, or
to a new mortal SV if C<sv> is C<NULL>.  It returns the modified C<sv>, or
C<NULL> if the core function has no prototype.  C<code> is a code as returned
by C<keyword()>.  It must not be equal to 0.  C<opnum> should be either C<NULL>
or the address of a variable that will be set to the op number corresponding to
C<name>, if any.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 1087; documented at op.c, line 16585

=head1 CV Handling

This section documents functions to manipulate CVs which are
code-values, meaning subroutines.  For more information, see
L<perlguts>.


=over 4

=item C<CvREFCOUNTED_ANYSV>
X<CvREFCOUNTED_ANYSV>

If true, indicates that the C<CvXSUBANY(cv).any_sv> member contains an SV
pointer whose reference count should be decremented when the CV itself is
freed.  In addition, C<cv_clone()> will increment the reference count, and
C<sv_dup()> will duplicate the entire pointed-to SV if this flag is set.

Any CV that wraps an XSUB has an C<ANY> union that the XSUB function is free
to use for its own purposes.  It may be the case that the code wishes to store
an SV in the C<any_sv> member of this union.  By setting this flag, this SV
reference will be properly reclaimed or duplicated when the CV itself is.

=over 3

 bool  CvREFCOUNTED_ANYSV(CV *cv)

=back

=back

=for hackers
Declared and documented at cv.h, line 257

=over 4

=item C<CvREFCOUNTED_ANYSV_off>
X<CvREFCOUNTED_ANYSV_off>

Helper macro to turn off the C<CvREFCOUNTED_ANYSV> flag.

=over 3

 void  CvREFCOUNTED_ANYSV_off(CV *cv)

=back

=back

=for hackers
Declared and documented at cv.h, line 273

=over 4

=item C<CvREFCOUNTED_ANYSV_on>
X<CvREFCOUNTED_ANYSV_on>

Helper macro to turn on the C<CvREFCOUNTED_ANYSV> flag.

=over 3

 void  CvREFCOUNTED_ANYSV_on(CV *cv)

=back

=back

=for hackers
Declared and documented at cv.h, line 269

=over 4

=item C<CvWEAKOUTSIDE>
X<CvWEAKOUTSIDE>

Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
CV (if any).  Because pointers to anonymous sub prototypes are
stored in C<&> 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 C<CvOUTSIDE> in the I<one specific instance> that the parent
has a C<&> pad slot pointing back to us.  In this case, we set the
C<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, I<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
C<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 $a is
executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
and the freed BEGIN is accessed.

To avoid this, whenever a CV and its associated pad is freed, any
C<&> 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 C<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 C<$a> above).

One other thing to consider is that a CV may be merely undefined
rather than freed, eg C<undef &foo>.  In this case, its refcount may
not have reached zero, but we still delete its pad and its C<CvROOT> etc.
Since various children may still have their C<CvOUTSIDE> pointing at this
undefined CV, we keep its own C<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->();

=over 3

 bool  CvWEAKOUTSIDE(CV *cv)

=back

=back

=for hackers
Declared and documented at cv.h, line 336

=over 4

=item C<docatch>
X<docatch>

Interpose, for the current op and RUNOPS loop,

    - a new JMPENV stack catch frame, and
    - an inner RUNOPS loop to run all the remaining ops following the
      current PL_op.

Then handle any exceptions raised while in that loop.
For a caught eval at this level, re-enter the loop with the specified
restart op (i.e. the op following the OP_LEAVETRY etc); otherwise re-throw
the exception.

docatch() is intended to be used like this:

    PP(pp_entertry)
    {
        if (CATCH_GET)
            return docatch(Perl_pp_entertry);

        ... rest of function ...
        return PL_op->op_next;
    }

If a new catch frame isn't needed, the op behaves normally. Otherwise it
calls docatch(), which recursively calls pp_entertry(), this time with
CATCH_GET() false, so the rest of the body of the entertry is run. Then
docatch() calls CALLRUNOPS() which executes all the ops following the
entertry. When the loop finally finishes, control returns to docatch(),
which pops the JMPENV and returns to the parent pp_entertry(), which
itself immediately returns. Note that *all* subsequent ops are run within
the inner RUNOPS loop, not just the body of the eval. For example, in

    sub TIEARRAY { eval {1}; my $x }
    tie @a, "main";

at the point the 'my' is executed, the C stack will look something like:

    #10 main()
    #9  perl_run()              # JMPENV_PUSH level 1 here
    #8  S_run_body()
    #7  Perl_runops_standard()  # main RUNOPS loop
    #6  Perl_pp_tie()
    #5  Perl_call_sv()
    #4  Perl_runops_standard()  # unguarded RUNOPS loop: no new JMPENV
    #3  Perl_pp_entertry()
    #2  S_docatch()             # JMPENV_PUSH level 2 here
    #1  Perl_runops_standard()  # docatch()'s RUNOPs loop
    #0  Perl_pp_padsv()

Basically, any section of the perl core which starts a RUNOPS loop may
make a promise that it will catch any exceptions and restart the loop if
necessary. If it's not prepared to do that (like call_sv() isn't), then
it sets CATCH_GET() to true, so that any later eval-like code knows to
set up a new handler and loop (via docatch()).

See L<perlinterp/"Exception handing"> for further details.

=over 3

 OP *  docatch(Perl_ppaddr_t firstpp)

=back

=back

=for hackers
Declared at embed.fnc, line 5374; documented at pp_ctl.c, line 3876

=head1 Debugging

=over 4

=item C<comma_aDEPTH>
X<comma_aDEPTH>

Some functions when compiled under DEBUGGING take an extra final argument named
C<depth>, indicating the C stack depth.  This argument is omitted otherwise.
This macro expands to either S<C<, depth>> under DEBUGGING, or to nothing at
all when not under DEBUGGING, reducing the number of C<#ifdef>'s in the code.

The program is responsible for maintaining the correct value for C<depth>.

=back

=for hackers
Declared and documented at perl.h, line 69

=over 4

=item C<comma_pDEPTH>
X<comma_pDEPTH>

This is used in the prototype declarations for functions that take a
L</C<comma_aDEPTH>> final parameter, much like L<C<pTHX_>|perlguts/Background
and MULTIPLICITY> is used in functions that take a thread context initial
parameter.

=back

=for hackers
Declared and documented at perl.h, line 77

=over 4

=item C<debop>
X<debop>

Implements B<-Dt> perl command line option on OP C<o>.

=over 3

 I32       debop(      const OP *o)
 I32  Perl_debop(pTHX_ const OP *o)

=back

=back

=for hackers
Declared at embed.fnc, line 1182; documented at dump.c, line 3621

=over 4

=item C<debprof>
X<debprof>

Called to indicate that C<o> was executed, for profiling purposes under the
C<-DP> command line option.

=over 3

 void  debprof(const OP *o)

=back

=back

=for hackers
Declared at embed.fnc, line 4693; documented at dump.c, line 3900

=over 4

=item C<debprofdump>
X<debprofdump>

Dumps the contents of the data collected by the C<-DP> perl command line
option.

=over 3

 void       debprofdump()
 void  Perl_debprofdump(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 1183; documented at dump.c, line 3921

=over 4

=item C<debug_aDEPTH>
X<debug_aDEPTH>

Same as L</C<comma_aDEPTH>> but with no leading argument. Intended for
functions with no normal arguments, and used by L</C<comma_aDEPTH>> itself.

=back

=for hackers
Declared and documented at perl.h, line 83

=over 4

=item C<DEBUG_L_FLAG>

Described in L<perlguts>.

=over 3

 U32  DEBUG_L_FLAG

=back

=back

=for hackers
Documented at pod/perlguts.pod, line 2967

=over 4

=item C<debug_pDEPTH>
X<debug_pDEPTH>

Same as L</C<comma_pDEPTH>> but with no leading argument. Intended for
functions with no normal arguments, and used by L</C<comma_pDEPTH>> itself.

=back

=for hackers
Declared and documented at perl.h, line 87

=over 4

=item C<free_c_backtrace>
X<free_c_backtrace>

Deallocates a backtrace received from get_c_backtrace.

=over 3

 void  free_c_backtrace(Perl_c_backtrace *bt)

=back

=back

=for hackers
Declared at embed.fnc, line 6604; documented at util.c, line 6642

=over 4

=item C<get_c_backtrace>
X<get_c_backtrace>

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

Scans the frames back by S<C<depth + skip>>, then drops the C<skip> innermost,
returning at most C<depth> frames.

=over 3

 Perl_c_backtrace *       get_c_backtrace(      int max_depth,
                                                int skip)
 Perl_c_backtrace *  Perl_get_c_backtrace(pTHX_ int max_depth,
                                                int skip)

=back

=back

=for hackers
Declared at embed.fnc, line 6606; documented at util.c, line 6397

=over 4

=item C<PL_DBsingle>
X<PL_DBsingle>

When Perl is run in debugging mode, with the B<-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
L<perlapi/C<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.

=over 3

 SV *  PL_DBsingle

=back

=back

=for hackers
Declared and documented at intrpvar.h, line 564

=over 4

=item C<PL_DBtrace>
X<PL_DBtrace>

Trace variable used when Perl is run in debugging mode, with the B<-d>
switch.  This is the C variable which corresponds to Perl's $DB::trace
variable.  See C<L</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.

=over 3

 SV *  PL_DBtrace

=back

=back

=for hackers
Declared and documented at intrpvar.h, line 575

=over 4

=item C<runops_debug>

=item C<runops_standard>

Described in L<perlguts>.

=over 3

 int       runops_debug   ()
 int  Perl_runops_debug   (pTHX)
 int       runops_standard()
 int  Perl_runops_standard(pTHX)

=back

=back

=for hackers
runops_debug declared at embed.fnc, line 3114; all in group documented at pod/perlguts.pod, line 2753
runops_standard declared at embed.fnc, line 3115

=head1 Declaration and Initialization of Globals

Global variables are defined and initialized in one place, but
referred to from multiple files.  They need to be defined and any
initialization done in that one place, but extern declarations
made for them in each file that may refer to them.  Note that
there is no harm in declaring a global and not using it.

Perl has a mechanism that allows both purposes to be served while
minimizing code duplication.  F<EXTERN.h> and F<INTERN.h> define
the same relatively few macros, but their definitions are
different.  In F<EXTERN.h>, the macros expand to
declarations of the globals as external to the file.  In
F<INTERN.h> they actually cause the space to be allocated and
possibly initialized.

Most files will follow this paradigm:

    #include "EXTERN.h"
    ...
    #include "perl.h">

This causes every global symbol that is referred to in F<perl.h>
and every file it includes (which is nearly every top level Perl
header file) to be declared as external.

The very few files that define globals will instead do

    #include "INTERN.h"
    ...
    #include "perl.h">
    include the file

It doesn't work for a file to both define some globals and refer
to others as externs.  That is, you can only include one of
F<INTERN.h> and F<EXTERN.h>.

This section documents the macros that are defined in these two
header files.  F<perl.h> has many uses of them that can serve as
paradigms for you.


=over 4

=item C<dEXT*>

=item C<dEXTCONST*>

Described under C<L</EXT>>

=back

=over 4

=item C<DOINIT>
X<DOINIT>

This is defined in F<INTERN.h>, undefined in F<EXTERN.h>

Most of the time you can use C<L</INIT>> to initialize your data structures.
But not always.  In such cases, you can do the following:

 #ifdef DOINIT
    ... do the declaration and definition ...
 #else
    declaration only
 #endif

A typical reason for needing this is when the definition includes #ifdef's.
You can't put that portably in a call to C<INIT>, as a macro generally can't
itself contain preprocessor directives.

=over 3

 #ifdef  DOINIT

=back

=back

=for hackers
Declared and documented at INTERN.h, line 89

=over 4

=item C<EXT>

=item C<EXTCONST>

=item C<dEXT>

=item C<dEXTCONST>
X<dEXT>X<dEXTCONST>X<EXT>X<EXTCONST>

These each designate a global variable.  The C<CONST> forms indicate that it is
constant.

Use them like this:

 Include either EXTERN.h or INTERN.h, but not both
 ...
 #include "perl.h"
 ...
 EXT char PL_WARN_ALL  INIT(0);
 EXTCONST U8 PL_revision  INIT(PERL_REVISION);

This will handle everything for you regarding whether they are to actually be
defined and initialized or just declared C<extern>.

If the initialization is complex, you may have to use C<L</DOINIT>>.

If some constants you wish to reference will not become defined by #including
F<perl.h>, instead use C<dEXT> and C<dEXTCONST> for them and include whatever
files you need to to get them.  This is currently very rare, and should be
avoided.

=back

=for hackers
EXT declared at INTERN.h, line 13; all in group documented at INTERN.h, line 13
EXTCONST 
dEXT 
dEXTCONST 

=over 4

=item C<INIT>
X<INIT>

Macro to initialize something, used like so:

 EXTCONST char PL_memory_wrap[]  INIT("panic: memory wrap");

It expands to nothing in F<EXTERN.h>.

=over 3

   INIT(const_expr)

=back

=back

=for hackers
Declared and documented at INTERN.h, line 75

=head1 Display functions

=over 4

=item C<sv_peek>
X<sv_peek>

Implements C<SvPEEK>

=over 3

 char *       sv_peek(      SV *sv)
 char *  Perl_sv_peek(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3567; documented at dump.c, line 447

=head1 Embedding, Threads, and Interpreter Cloning

=over 4

=item C<cv_dump>
X<cv_dump>

dump the contents of a CV

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 5278; documented at pad.c, line 1917

=over 4

=item C<cv_forget_slab>
X<cv_forget_slab>

When a CV has a reference count on its slab (C<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 C<CvROOT> attached, it has
finished its job, so it can forget the slab.

=over 3

 void       cv_forget_slab(      CV *cv)
 void  Perl_cv_forget_slab(pTHX_ CV *cv)

=back

=back

=for hackers
Declared at embed.fnc, line 1145; documented at pad.c, line 499

=over 4

=item C<do_dump_pad>
X<do_dump_pad>

Dump the contents of a padlist

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 1227; documented at pad.c, line 1845

=over 4

=item C<get_context>
X<get_context>

Implements L<perlapi/C<PERL_GET_CONTEXT>>, which you should use instead.

=over 3

 void *       get_context()
 void *  Perl_get_context()

=back

=back

=for hackers
Declared at embed.fnc, line 6787; documented at inline.h, line 5139

=over 4

=item C<noshutdownhook>
X<noshutdownhook>

Stub that provides shutdown hook.

=over 3

 void       noshutdownhook()
 void  Perl_noshutdownhook()

=back

=back

=for hackers
Declared at embed.fnc, line 2614; documented at perl.c, line 488

=over 4

=item C<pad_alloc_name>
X<pad_alloc_name>

Allocates a place in the currently-compiling
pad (via L<perlapi/pad_alloc>) and
then stores a name for that entry.  C<name> is adopted and
becomes the name entry; it must already contain the name
string.  C<typestash> and C<ourstash> and the C<padadd_STATE>
flag gets added to C<name>.
None of the other processing of L<perlapi/pad_add_name_pvn>
is done.  Returns the offset of the allocated pad slot.

=over 3

 PADOFFSET  pad_alloc_name(PADNAME *name, U32 flags,
                           NOCHECK HV *typestash, HV *ourstash)

=back

=back

=for hackers
Declared at embed.fnc, line 5259; documented at pad.c, line 543

=over 4

=item C<pad_block_start>
X<pad_block_start>

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

=over 3

 void       pad_block_start(      int full)
 void  Perl_pad_block_start(pTHX_ int full)

=back

=back

=for hackers
Declared at embed.fnc, line 2697; documented at pad.c, line 1447

=over 4

=item C<pad_check_dup>
X<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'

C<is_our> indicates that the name to check is an C<"our"> declaration.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 5264; documented at pad.c, line 885

=over 4

=item C<pad_findlex>
X<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.
C<cv> is the CV in which to start the search, and seq is the current C<cop_seq>
to match against.  If C<warn> is true, print appropriate warnings.  The C<out_>*
vars return values, and so are pointers to where the returned values
should be stored.  C<out_capture>, if non-null, requests that the innermost
instance of the lexical is captured; C<out_name> is set to the innermost
matched pad name or fake pad name; C<out_flags> returns the flags normally
associated with the C<PARENT_FAKELEX_FLAGS> field of a fake pad name.

Note that C<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 C<xpadn_low> the
index into the parent pad.

=over 3

 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)

=back

=back

=for hackers
Declared at embed.fnc, line 5267; documented at pad.c, line 1093

=over 4

=item C<pad_fixup_inner_anons>
X<pad_fixup_inner_anons>

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

=over 3

 void       pad_fixup_inner_anons(      PADLIST *padlist,
                                        CV *old_cv, CV *new_cv)
 void  Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist,
                                        CV *old_cv, CV *new_cv)

=back

=back

=for hackers
Declared at embed.fnc, line 2706; documented at pad.c, line 2402

=over 4

=item C<pad_free>
X<pad_free>

Free the SV at offset po in the current pad.

=over 3

 void       pad_free(      PADOFFSET po)
 void  Perl_pad_free(pTHX_ PADOFFSET po)

=back

=back

=for hackers
Declared at embed.fnc, line 2710; documented at pad.c, line 1805

=over 4

=item C<pad_leavemy>
X<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.

=over 3

 OP *       pad_leavemy()
 OP *  Perl_pad_leavemy(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2711; documented at pad.c, line 1537

=over 4

=item C<pad_push>
X<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 C<@_> in slot zero.

=over 3

 void       pad_push(      PADLIST *padlist, int depth)
 void  Perl_pad_push(pTHX_ PADLIST *padlist, int depth)

=back

=back

=for hackers
Declared at embed.fnc, line 2728; documented at pad.c, line 2475

=over 4

=item C<pad_reset>
X<pad_reset>

Mark all the current temporaries for reuse

=over 3

 void  pad_reset()

=back

=back

=for hackers
Declared at embed.fnc, line 5276; documented at pad.c, line 1649

=over 4

=item C<pad_setsv>
X<pad_setsv>

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

=over 3

 void       pad_setsv(      PADOFFSET po, SV *sv)
 void  Perl_pad_setsv(pTHX_ PADOFFSET po, SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 4242; documented at pad.c, line 1422

=over 4

=item C<pad_sv>
X<pad_sv>

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

=over 3

 SV *       pad_sv(      PADOFFSET po)
 SV *  Perl_pad_sv(pTHX_ PADOFFSET po)

=back

=back

=for hackers
Declared at embed.fnc, line 4244; documented at pad.c, line 1397

=over 4

=item C<pad_swipe>
X<pad_swipe>

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

=over 3

 void       pad_swipe(      PADOFFSET po, bool refadjust)
 void  Perl_pad_swipe(pTHX_ PADOFFSET po, bool refadjust)

=back

=back

=for hackers
Declared at embed.fnc, line 2730; documented at pad.c, line 1595

=over 4

=item C<padlist_dup>
X<padlist_dup>

Duplicates a pad.

=over 3

 PADLIST *       padlist_dup(      PADLIST *srcpad,
                                   CLONE_PARAMS *param)
 PADLIST *  Perl_padlist_dup(pTHX_ PADLIST *srcpad,
                                   CLONE_PARAMS *param)

=back

=back

=for hackers
Declared at embed.fnc, line 6659; documented at pad.c, line 2556

=over 4

=item C<padname_dup>
X<padname_dup>

Duplicates a pad name.

=over 3

 PADNAME *       padname_dup(      PADNAME *src,
                                   CLONE_PARAMS *param)
 PADNAME *  Perl_padname_dup(pTHX_ PADNAME *src,
                                   CLONE_PARAMS *param)

=back

=back

=for hackers
Declared at embed.fnc, line 6661; documented at pad.c, line 2927

=over 4

=item C<padnamelist_dup>
X<padnamelist_dup>

Duplicates a pad name list.

=over 3

 PADNAMELIST *       padnamelist_dup(      PADNAMELIST *srcpad,
                                           CLONE_PARAMS *param)
 PADNAMELIST *  Perl_padnamelist_dup(pTHX_ PADNAMELIST *srcpad,
                                           CLONE_PARAMS *param)

=back

=back

=for hackers
Declared at embed.fnc, line 6663; documented at pad.c, line 2791

=over 4

=item C<set_context>
X<set_context>

Implements L<perlapi/C<PERL_SET_CONTEXT>>, which you should use instead.

=over 3

 void       set_context(void *t)
 void  Perl_set_context(void *t)

=back

=back

=for hackers
Declared at embed.fnc, line 3264; documented at util.c, line 3603

=over 4

=item C<si_dup>
X<si_dup>

Duplicate a stack info structure, returning a pointer to the cloned object.

=over 3

 PERL_SI *       si_dup(      PERL_SI *si, CLONE_PARAMS *param)
 PERL_SI *  Perl_si_dup(pTHX_ PERL_SI *si, CLONE_PARAMS *param)

=back

=back

=for hackers
Declared at embed.fnc, line 6680; documented at sv.c, line 16012

=over 4

=item C<ss_dup>
X<ss_dup>

Duplicate the save stack, returning a pointer to the cloned object.

=over 3

 ANY *       ss_dup(      PerlInterpreter *proto_perl,
                          CLONE_PARAMS *param)
 ANY *  Perl_ss_dup(pTHX_ PerlInterpreter *proto_perl,
                          CLONE_PARAMS *param)

=back

=back

=for hackers
Declared at embed.fnc, line 6682; documented at sv.c, line 16109

=head1 Errno

=over 4

=item C<dSAVE_ERRNO>
X<dSAVE_ERRNO>

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

=over 3

 void  dSAVE_ERRNO

=back

=back

=for hackers
Declared and documented at perl.h, line 1838

=over 4

=item C<dSAVEDERRNO>
X<dSAVEDERRNO>

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

=over 3

 void  dSAVEDERRNO

=back

=back

=for hackers
Declared and documented at perl.h, line 1833

=over 4

=item C<RESTORE_ERRNO>
X<RESTORE_ERRNO>

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

=over 3

 void  RESTORE_ERRNO

=back

=back

=for hackers
Declared and documented at perl.h, line 1850

=over 4

=item C<SAVE_ERRNO>
X<SAVE_ERRNO>

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

=over 3

 void  SAVE_ERRNO

=back

=back

=for hackers
Declared and documented at perl.h, line 1844

=over 4

=item C<SETERRNO>
X<SETERRNO>

Set C<errno>, and on VMS set C<vaxc$errno>.

=over 3

 void  SETERRNO(int errcode, int vmserrcode)

=back

=back

=for hackers
Declared and documented at perl.h, line 1829

=head1 Exception Handling (simple) Macros

There are currently no internal API items in Exception Handling (simple) Macros

=head1 Filesystem configuration values

There are currently no internal API items in Filesystem configuration values

=head1 Floating point

There are currently no internal API items in Floating point

=head1 General Configuration

There are currently no internal API items in General Configuration

=head1 Global Variables

There are currently no internal API items in Global Variables

=head1 GV Handling and Stashes
X<GV_CACHE_ONLY>


A GV is a structure which corresponds to a Perl typeglob, I<i.e.>, *foo.
It is a structure that holds a pointer to a scalar, an array, a hash etc,
corresponding to $foo, @foo, %foo.

GVs are usually found as values in stashes (symbol table hashes) where
Perl stores its global variables.

A B<stash> is a hash that contains all variables that are defined
within a package.  See L<perlguts/Stashes and Globs>


=over 4

=item C<amagic_applies>
X<amagic_applies>

Check C<sv> to see if the overloaded (active magic) operation C<method>
applies to it. If the sv is not SvROK or it is not an object then returns
false, otherwise checks if the object is blessed into a class supporting
overloaded operations, and returns true if a call to amagic_call() with
this SV and the given method would trigger an amagic operation, including
via the overload fallback rules or via nomethod. Thus a call like:

    amagic_applies(sv, string_amg, AMG_unary)

would return true for an object with overloading set up in any of the
following ways:

    use overload q("") => sub { ... };
    use overload q(0+) => sub { ... }, fallback => 1;

and could be used to tell if a given object would stringify to something
other than the normal default ref stringification.

Note that the fact that this function returns TRUE does not mean you
can successfully perform the operation with amagic_call(), for instance
any overloaded method might throw a fatal exception,  however if this
function returns FALSE you can be confident that it will NOT perform
the given overload operation.

C<method> is an integer enum, one of the values found in F<overload.h>,
for instance C<string_amg>.

C<flags> should be set to AMG_unary for unary operations.

=over 3

 bool       amagic_applies(      SV *sv, int method, int flags)
 bool  Perl_amagic_applies(pTHX_ SV *sv, int method, int flags)

=back

=back

=for hackers
Declared at embed.fnc, line 856; documented at gv.c, line 3426

=over 4

=item C<gp_dup>
X<gp_dup>

Duplicate a typeglob, returning a pointer to the cloned object.

=over 3

 GP *       gp_dup(      GP * const gp,
                         CLONE_PARAMS * const param)
 GP *  Perl_gp_dup(pTHX_ GP * const gp,
                         CLONE_PARAMS * const param)

=back

=back

=for hackers
Declared at embed.fnc, line 6643; documented at sv.c, line 14985

=over 4

=item C<gv_handler>
X<gv_handler>

Implements C<StashHANDLER>, which you should use instead

=over 3

 CV *       gv_handler(      HV *stash, I32 id)
 CV *  Perl_gv_handler(pTHX_ HV *stash, I32 id)

=back

=back

=for hackers
Declared at embed.fnc, line 1645; documented at gv.c, line 3315

=over 4

=item C<gv_stashsvpvn_cached>
X<gv_stashsvpvn_cached>

Returns a pointer to the stash for a specified package, possibly
cached.  Implements both L<perlapi/C<gv_stashpvn>> and
L<perlapi/C<gv_stashsv>>.

Requires one of either C<namesv> or C<namepv> to be non-null.

If the flag C<GV_CACHE_ONLY> is set, return the stash only if found in the
cache; see L<perlapi/C<gv_stashpvn>> for details on the other C<flags>.

Note it is strongly preferred for C<namesv> to be non-null, for performance
reasons.

=over 3

 HV *       gv_stashsvpvn_cached(SV *namesv, const char *name,
                          U32 namelen,
                          I32 flags                              )
 HV *  Perl_gv_stashsvpvn_cached(pTHX_ SV *namesv,
                          const char *name, U32 namelen,
                          I32 flags                              )

=back

=back

=for hackers
Declared at embed.fnc, line 4773; documented at gv.c, line 1689

=over 4

=item C<gv_try_downgrade>
X<gv_try_downgrade>

NOTE: C<gv_try_downgrade> is B<experimental> and may change or be
removed without notice.

If the typeglob C<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 C<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 C<gv> is a completely empty typeglob, it is deleted from the stash.

If C<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.

=over 3

 void       gv_try_downgrade(      GV *gv)
 void  Perl_gv_try_downgrade(pTHX_ GV *gv)

=back

=back

=for hackers
Declared at embed.fnc, line 1683; documented at gv.c, line 4345

=head1 Hook manipulation

There are currently no internal API items in Hook manipulation

=head1 HV Handling
X<HvNAME_get>


A HV structure represents a Perl hash.  It consists mainly of an array
of pointers, each of which points to a linked list of HE structures.  The
array is indexed by the hash function of the key, so each linked list
represents all the hash entries with the same hash value.  Each HE contains
a pointer to the actual value, plus a pointer to a HEK structure which
holds the key and hash value.


=over 4

=item C<hv_eiter_p>
X<hv_eiter_p>

Implements C<HvEITER> which you should use instead.

=over 3

 HE **  Perl_hv_eiter_p(pTHX_ HV *hv)

=back

=back

=for hackers
Declared at embed.fnc, line 1724; documented at hv.c, line 2568

=over 4

=item C<hv_eiter_set>
X<hv_eiter_set>

Implements C<HvEITER_set> which you should use instead.

=over 3

 void  Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter)

=back

=back

=for hackers
Declared at embed.fnc, line 1725; documented at hv.c, line 2632

=over 4

=item C<hv_ename_add>
X<hv_ename_add>

Adds a name to a stash's internal list of effective names.  See
C<L</hv_ename_delete>>.

This is called when a stash is assigned to a new location in the symbol
table.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 1727; documented at hv.c, line 2778

=over 4

=item C<hv_ename_delete>
X<hv_ename_delete>

Removes a name from a stash's internal list of effective names.  If this is
the name returned by C<HvENAME>, then another name in the list will take
its place (C<HvENAME> will use it).

This is called when a stash is deleted from the symbol table.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 1731; documented at hv.c, line 2841

=over 4

=item C<hv_fill>
X<hv_fill>

Returns the number of hash buckets that happen to be in use.

This function implements the L<C<HvFILL> macro|perlapi/HvFILL> which you should
use instead.

As of perl 5.25 this function is used only for debugging
purposes, and the number of used hash buckets is not
in any way cached, thus this function can be costly
to execute as it must iterate over all the buckets in the
hash.

=over 3

 STRLEN  Perl_hv_fill(pTHX_ HV * const hv)

=back

=back

=for hackers
Declared at embed.fnc, line 1749; documented at hv.c, line 2426

=over 4

=item C<hv_placeholders_get>
X<hv_placeholders_get>

Implements C<HvPLACEHOLDERS_get>, which you should use instead.

=over 3

 I32  Perl_hv_placeholders_get(pTHX_ const HV *hv)

=back

=back

=for hackers
Declared at embed.fnc, line 1774; documented at hv.c, line 3530

=over 4

=item C<hv_placeholders_set>
X<hv_placeholders_set>

Implements C<HvPLACEHOLDERS_set>, which you should use instead.

=over 3

 void  Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)

=back

=back

=for hackers
Declared at embed.fnc, line 1778; documented at hv.c, line 3549

=over 4

=item C<hv_riter_p>
X<hv_riter_p>

Implements C<HvRITER> which you should use instead.

=over 3

 I32 *  Perl_hv_riter_p(pTHX_ HV *hv)

=back

=back

=for hackers
Declared at embed.fnc, line 1785; documented at hv.c, line 2549

=over 4

=item C<hv_riter_set>
X<hv_riter_set>

Implements C<HvRITER_set> which you should use instead.

=over 3

 void  Perl_hv_riter_set(pTHX_ HV *hv, I32 riter)

=back

=back

=for hackers
Declared at embed.fnc, line 1786; documented at hv.c, line 2587

=over 4

=item C<refcounted_he_chain_2hv>
X<refcounted_he_chain_2hv>

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

=over 3

 HV *       refcounted_he_chain_2hv(const struct refcounted_he *c,
                                    U32 flags)
 HV *  Perl_refcounted_he_chain_2hv(pTHX_
                                    const struct refcounted_he *c,
                                    U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 2890; documented at hv.c, line 3614

=over 4

=item C<refcounted_he_fetch_pv>

=item C<refcounted_he_fetch_pvn>

=item C<refcounted_he_fetch_pvs>

=item C<refcounted_he_fetch_sv>
X<refcounted_he_fetch_pv>X<refcounted_he_fetch_pvn>
X<refcounted_he_fetch_pvs>X<refcounted_he_fetch_sv>

These each search along a C<refcounted_he> C<chain> for an entry with the
specified key.  The return depends on the C<REFCOUNTED_HE_EXISTS> bit in
C<flags>.  If unset, a mortal scalar representing the value associated with
the key is returned, or C<&PL_sv_placeholder> if there is no value associated
with the key.  If set, and there is such a value C<&PL_yes> is returned; if no
such value, NULL is returned.

C<hash> is a precomputed hash of the key string, or zero if it has not been
precomputed

The forms differ only in how the key is specified.

In C<refcounted_he_fetch_pv>, C<key> specifies the key as a C language
NUL-terminated string.

In C<refcounted_he_fetch_pvs>, the key is a C language string literal, enclosed
in double quotes.

In C<refcounted_he_fetch_pvn>, C<key> points to the first byte of the string
specifying the key, and an additional parameter, C<keylen>, specifies its
length in bytes.  Hence, C<key> may contain embedded-NUL characters.

In C<refcounted_he_fetch_sv>, C<*key> is an SV, and the key is the PV
extracted from that using L<perlapi/C<SvPV_const>>.

=over 3

 SV *       refcounted_he_fetch_pv (
                               const struct refcounted_he *chain,
                                const char *key, U32 hash,
                                U32 flags)
 SV *  Perl_refcounted_he_fetch_pv (pTHX_
                                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 *  Perl_refcounted_he_fetch_pvn(pTHX_
                                const struct refcounted_he *chain,
                                const char *keypv, STRLEN keylen,
                                U32 hash, U32 flags)
 SV *       refcounted_he_fetch_pvs(
                               const struct refcounted_he *chain,
                                const char *key, U32 hash,
                                U32 flags)
 SV *       refcounted_he_fetch_sv (
                               const struct refcounted_he *chain,
                                SV *key, U32 hash, U32 flags)
 SV *  Perl_refcounted_he_fetch_sv (pTHX_
                                const struct refcounted_he *chain,
                                SV *key, U32 hash, U32 flags)

=back

=back

=for hackers
refcounted_he_fetch_pv declared at embed.fnc, line 2893; all in group documented at hv.c, line 3727
refcounted_he_fetch_pvn declared at embed.fnc, line 2898
refcounted_he_fetch_pvs declared at hv.c, line 3729
refcounted_he_fetch_sv declared at embed.fnc, line 2904

=over 4

=item C<refcounted_he_free>
X<refcounted_he_free>

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

=over 3

 void       refcounted_he_free(      struct refcounted_he *he)
 void  Perl_refcounted_he_free(pTHX_ struct refcounted_he *he)

=back

=back

=for hackers
Declared at embed.fnc, line 2909; documented at hv.c, line 3991

=over 4

=item C<refcounted_he_inc>
X<refcounted_he_inc>

Increment the reference count of a C<refcounted_he>.  The pointer to the
C<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.

=over 3

 struct refcounted_he *       refcounted_he_inc(
                                        struct refcounted_he *he)
 struct refcounted_he *  Perl_refcounted_he_inc(pTHX_
                                         struct refcounted_he *he)

=back

=back

=for hackers
Declared at embed.fnc, line 2911; documented at hv.c, line 4029

=over 4

=item C<refcounted_he_new_pv>

=item C<refcounted_he_new_pvn>

=item C<refcounted_he_new_pvs>

=item C<refcounted_he_new_sv>
X<refcounted_he_new_pv>X<refcounted_he_new_pvn>X<refcounted_he_new_pvs>
X<refcounted_he_new_sv>

These each create a new C<refcounted_he>.  This consists of a single key/value
pair and a reference to an existing C<refcounted_he> chain (which may be
empty), thus forming 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.

C<hash> is a precomputed hash of the key string, or zero if it has not been
precomputed.  C<refcounted_he_new_pvs> doesn't have a C<hash> parameter, as
that is determinable at compile time.

The forms otherwise differ only in how the key is specified.

The new key is specified by C<keypv> and C<keylen>.  If C<flags> has
the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
as UTF-8, otherwise they are interpreted as Latin-1.

C<value> is the scalar value to store for this key.  C<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 C<refcounted_he>.  Complex types of scalar will not
be stored with referential integrity, but will be coerced to strings.
C<value> may be either NULL or C<&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.

C<parent> points to the rest of the C<refcounted_he> chain to be
attached to the new C<refcounted_he>.  This function takes ownership
of one reference to C<parent>, and returns one reference to the new
C<refcounted_he>.

=over 3

 struct refcounted_he *       refcounted_he_new_pv (
                                    struct refcounted_he *parent,
                                     const char *key, U32 hash,
                                     SV *value, U32 flags)
 struct refcounted_he *  Perl_refcounted_he_new_pv (pTHX_
                                     struct refcounted_he *parent,
                                     const char *key, U32 hash,
                                     SV *value, U32 flags)
 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 *  Perl_refcounted_he_new_pvn(pTHX_
                                     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,
                                     const char *key, U32 hash,
                                     SV *value, U32 flags)
 struct refcounted_he *       refcounted_he_new_sv (
                                    struct refcounted_he *parent,
                                     SV *key, U32 hash, SV *value,
                                     U32 flags)
 struct refcounted_he *  Perl_refcounted_he_new_sv (pTHX_
                                     struct refcounted_he *parent,
                                     SV *key, U32 hash, SV *value,
                                     U32 flags)

=back

=back

=for hackers
refcounted_he_new_pv declared at embed.fnc, line 2913; all in group documented at hv.c, line 3839
refcounted_he_new_pvn declared at embed.fnc, line 2919
refcounted_he_new_pvs declared at hv.c, line 3841
refcounted_he_new_sv declared at embed.fnc, line 2926

=over 4

=item C<unsharepvn>
X<unsharepvn>

If no one has access to shared string C<str> with length C<len>, free it.

C<len> and C<hash> must both be valid for C<str>.

=over 3

 void       unsharepvn(      const char *sv, I32 len, U32 hash)
 void  Perl_unsharepvn(pTHX_ const char *sv, I32 len, U32 hash)

=back

=back

=for hackers
Declared at embed.fnc, line 3950; documented at hv.c, line 3263

=head1 Input/Output

=over 4

=item C<dirp_dup>
X<dirp_dup>

Duplicate a directory handle, returning a pointer to the cloned object.

=over 3

 DIR *       dirp_dup(      DIR * const dp,
                            CLONE_PARAMS * const param)
 DIR *  Perl_dirp_dup(pTHX_ DIR * const dp,
                            CLONE_PARAMS * const param)

=back

=back

=for hackers
Declared at embed.fnc, line 6638; documented at sv.c, line 14943

=over 4

=item C<fp_dup>
X<fp_dup>

Duplicate a file handle, returning a pointer to the cloned object.

=over 3

 PerlIO *       fp_dup(      PerlIO * const fp, const char type,
                             CLONE_PARAMS * const param)
 PerlIO *  Perl_fp_dup(pTHX_ PerlIO * const fp, const char type,
                             CLONE_PARAMS * const param)

=back

=back

=for hackers
Declared at embed.fnc, line 6640; documented at sv.c, line 14907

=over 4

=item C<my_fflush_all>
X<my_fflush_all>

Implements C<PERL_FLUSHALL_FOR_CHILD> on some platforms.

=over 3

 I32       my_fflush_all()
 I32  Perl_my_fflush_all(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2314; documented at util.c, line 3726

=over 4

=item C<my_mkostemp>
X<my_mkostemp>

The C library C<L<mkostemp(3)>> if available, or a Perl implementation of it.

=over 3

 int  Perl_my_mkostemp(char *templte, int flags)

=back

=back

=for hackers
Declared at embed.fnc, line 4262; documented at util.c, line 5931

=over 4

=item C<my_mkstemp>
X<my_mkstemp>

The C library C<L<mkstemp(3)>> if available, or a Perl implementation of it.

=over 3

 int  Perl_my_mkstemp(char *templte)

=back

=back

=for hackers
Declared at embed.fnc, line 4266; documented at util.c, line 5949

=over 4

=item C<PL_last_in_gv>
X<PL_last_in_gv>

The GV which was last used for a filehandle input operation.  (C<< <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.

=over 3

 GV*  PL_last_in_gv

=back

=back

=for hackers
Declared and documented at intrpvar.h, line 294

=over 4

=item C<PL_ofsgv>
X<PL_ofsgv>

The glob containing the output field separator - C<*,> 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.

=over 3

 GV*  PL_ofsgv

=back

=back

=for hackers
Declared and documented at intrpvar.h, line 303

=over 4

=item C<PL_rs>
X<PL_rs>

The input record separator - C<$/> 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.

=over 3

 SV*  PL_rs

=back

=back

=for hackers
Declared and documented at intrpvar.h, line 285

=over 4

=item C<start_glob>
X<start_glob>

NOTE: C<start_glob> is B<experimental> and may change or be
removed without notice.

Function called by C<do_readline> to spawn a glob (or do the glob inside
perl on VMS).  This code used to be inline, but now perl uses C<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 F<pp_hot.c>; shrinking F<pp_hot.c> helps speed perl up.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 3304; documented at doio.c, line 3437

=over 4

=item C<USE_STDIO>

Described in L<perlapio>.

=over 3

 #ifdef  USE_STDIO

=back

=back

=for hackers
Documented at pod/perlapio.pod, line 157

=head1 Integer

=over 4

=item C<ABS_IV_MIN>
X<ABS_IV_MIN>

Returns the absolute value of L<perlapi/C<IV_MIN>>, suitable for use in a UV

=over 3

 UV  ABS_IV_MIN

=back

=back

=for hackers
Declared and documented at handy.h, line 3282

=over 4

=item C<NEGATE_2IV>
X<NEGATE_2IV>

Returns the negative value of C<uv>, which must be non-negative, for use in an
IV.  The results are undefined if that value would be less than
L<perlapi/C<IV_MIN>>.  This macro is needed because naively saying C<-uv> gives
undefined behavior when C<uv> is equal to C<L</ABS_IV_MIN>>.

=over 3

 IV  NEGATE_2IV(UV uv)

=back

=back

=for hackers
Declared and documented at handy.h, line 3292

=over 4

=item C<NEGATE_2UV>
X<NEGATE_2UV>

Returns the absolute value of C<iv>, which must be negative, while avoiding
undefined behavior even if C<iv> is L<perlapi/C<IV_MIN>>.

=over 3

 UV  NEGATE_2UV(IV iv)

=back

=back

=for hackers
Declared and documented at handy.h, line 3267

=head1 I/O Formats

There are currently no internal API items in I/O Formats

=head1 Lexer interface


This is the lower layer of the Perl parser, managing characters and tokens.


=over 4

=item C<validate_proto>
X<validate_proto>

NOTE: C<validate_proto> is B<experimental> and may change or be
removed without notice.

This function performs syntax checking on a prototype, C<proto>.
If C<warn> is true, any illegal characters or mismatched brackets
will trigger illegalproto warnings, declaring that they were
detected in the prototype for C<name>.

The return value is C<true> if this is a valid prototype, and
C<false> if it is not, regardless of whether C<warn> was C<true> or
C<false>.

Note that C<NULL> is a valid C<proto> and will always return C<true>.

=over 3

 bool       validate_proto(      SV *name, SV *proto, bool warn,
                                 bool curstash)
 bool  Perl_validate_proto(pTHX_ SV *name, SV *proto, bool warn,
                                 bool curstash)

=back

=back

=for hackers
Declared at embed.fnc, line 4132; documented at toke.c, line 1810

=head1 Locales

There are currently no internal API items in Locales

=head1 Magic


"Magic" is special data attached to SV structures in order to give them
"magical" properties.  When any Perl code tries to read from, or assign to,
an SV marked as magical, it calls the 'get' or 'set' function associated
with that SV's magic.  A get is called prior to reading an SV, in order to
give it a chance to update its internal value (get on $. writes the line
number of the last read filehandle into the SV's IV slot), while
set is called after an SV has been written to, in order to allow it to make
use of its changed value (set on $/ copies the SV's new value to the
PL_rs global variable).

Magic is implemented as a linked list of MAGIC structures attached to the
SV.  Each MAGIC struct holds the type of the magic, a pointer to an array
of functions that implement the get(), set(), length() etc functions,
plus space for some flags and pointers.  For example, a tied variable has
a MAGIC structure that contains a pointer to the object associated with the
tie.


=over 4

=item C<magic_clearhint>
X<magic_clearhint>

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

=over 3

 int       magic_clearhint(      SV *sv, MAGIC *mg)
 int  Perl_magic_clearhint(pTHX_ SV *sv, MAGIC *mg)

=back

=back

=for hackers
Declared at embed.fnc, line 2058; documented at mg.c, line 3979

=over 4

=item C<magic_clearhints>
X<magic_clearhints>

Triggered by clearing C<%^H>, resets C<PL_compiling.cop_hints_hash>.

=over 3

 int       magic_clearhints(      SV *sv, MAGIC *mg)
 int  Perl_magic_clearhints(pTHX_ SV *sv, MAGIC *mg)

=back

=back

=for hackers
Declared at embed.fnc, line 2060; documented at mg.c, line 4007

=over 4

=item C<magic_methcall>
X<magic_methcall>

Invoke a magic method (like FETCH).

C<sv> and C<mg> are the tied thingy and the tie magic.

C<meth> is the name of the method to call.

C<argc> is the number of args (in addition to $self) to pass to the method.

The C<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 C<flags> argument.

Returns the SV (if any) returned by the method, or C<NULL> on failure.

=over 3

 SV *       magic_methcall(      SV *sv, const MAGIC *mg,
                                 SV *meth, U32 flags, U32 argc,
                                 ...)
 SV *  Perl_magic_methcall(pTHX_ SV *sv, const MAGIC *mg,
                                 SV *meth, U32 flags, U32 argc,
                                 ...)

=back

=back

=for hackers
Declared at embed.fnc, line 2126; documented at mg.c, line 2114

=over 4

=item C<magic_sethint>
X<magic_sethint>

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

=over 3

 int       magic_sethint(      SV *sv, MAGIC *mg)
 int  Perl_magic_sethint(pTHX_ SV *sv, MAGIC *mg)

=back

=back

=for hackers
Declared at embed.fnc, line 2169; documented at mg.c, line 3946

=over 4

=item C<mg_dup>
X<mg_dup>

Duplicate a chain of magic, returning a pointer to the cloned object.

=over 3

 MAGIC *       mg_dup(      MAGIC *mg, CLONE_PARAMS * const param)
 MAGIC *  Perl_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS * const param)

=back

=back

=for hackers
Declared at embed.fnc, line 6650; documented at sv.c, line 15029

=over 4

=item C<mg_localize>
X<mg_localize>

Copy some of the magic from an existing SV to new localized version of that
SV.  Container magic (I<e.g.>, C<%ENV>, C<$1>, C<tie>)
gets copied, value magic doesn't (I<e.g.>,
C<taint>, C<pos>).

If C<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. S<C<'local $x = $y'>>),
and that will handle the magic.

=over 3

 void       mg_localize(      SV *sv, SV *nsv, bool setmagic)
 void  Perl_mg_localize(pTHX_ SV *sv, SV *nsv, bool setmagic)

=back

=back

=for hackers
Declared at embed.fnc, line 2242; documented at mg.c, line 469

=head1 Memory Management

=over 4

=item C<calloc>
X<calloc>

Implements L<perlapi/C<Newxz>> which you should use instead.

=over 3

 Malloc_t  Perl_calloc(MEM_SIZE elements, MEM_SIZE size)

=back

=back

=for hackers
Declared at embed.fnc, line 1008; documented at malloc.c, line 2089

=over 4

=item C<malloc>
X<malloc>

Implements L<perlapi/C<Newx>> which you should use instead.

=over 3

 Malloc_t  Perl_malloc(MEM_SIZE nbytes)

=back

=back

=for hackers
Declared at embed.fnc, line 2212; documented at malloc.c, line 1215

=over 4

=item C<mfree>
X<mfree>

Implements L<perlapi/C<Safefree>> which you should use instead.

=over 3

 Free_t  Perl_mfree(Malloc_t where)

=back

=back

=for hackers
Declared at embed.fnc, line 2221; documented at malloc.c, line 1790

=over 4

=item C<realloc>
X<realloc>

Implements L<perlapi/C<Renew>> which you should use instead.

=over 3

 Malloc_t  Perl_realloc(Malloc_t where, MEM_SIZE nbytes)

=back

=back

=for hackers
Declared at embed.fnc, line 2879; documented at malloc.c, line 1887

=head1 MRO


These functions are related to the method resolution order of perl classes
Also see L<perlmroapi>.


=over 4

=item C<mro_get_linear_isa_dfs>
X<mro_get_linear_isa_dfs>

Returns the Depth-First Search linearization of C<@ISA>
the given stash.  The return value is a read-only AV*
whose elements are string SVs giving class names.
C<level> should be 0 (it is used internally in this
function's recursion).

You are responsible for C<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).

=over 3

 AV *  mro_get_linear_isa_dfs(HV *stash, U32 level)

=back

=back

=for hackers
Declared at embed.fnc, line 5103; documented at mro_core.c, line 221

=over 4

=item C<mro_isa_changed_in>
X<mro_isa_changed_in>

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

=over 3

 void       mro_isa_changed_in(      HV *stash)
 void  Perl_mro_isa_changed_in(pTHX_ HV *stash)

=back

=back

=for hackers
Declared at embed.fnc, line 2274; documented at mro_core.c, line 490

=over 4

=item C<mro_package_moved>
X<mro_package_moved>

Call this function to signal to a stash that it has been assigned to
another spot in the stash hierarchy.  C<stash> is the stash that has been
assigned.  C<oldstash> is the stash it replaces, if any.  C<gv> is the glob
that is actually being assigned to.

This can also be called with a null first argument to
indicate that C<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 C<stash>.

It also sets the effective names (C<HvENAME>) on all the stashes as
appropriate.

If the C<gv> is present and is not in the symbol table, then this function
simply returns.  This checked will be skipped if C<flags & 1>.

=over 3

 void       mro_package_moved(      HV * const stash,
                                    HV * const oldstash,
                                    const GV * const gv,
                                    U32 flags)
 void  Perl_mro_package_moved(pTHX_ HV * const stash,
                                    HV * const oldstash,
                                    const GV * const gv,
                                    U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 2281; documented at mro_core.c, line 741

=head1 Multicall Functions

There are currently no internal API items in Multicall Functions

=head1 Numeric Functions

=over 4

=item C<grok_uint_by_base>
X<grok_uint_by_base>

Parses a string purportedly containing ASCII digit characters in the numeric
base passed in as 'base', and translates it to a non-negative integer, if
possible, which it returns.  The base is any of 2, 8, 10, or 16.  The string
to be parsed starts at 'start' and has length *len_p bytes.  If *len_p is 0, 0
is returned without complaint.

It stops parsing when it reaches *len_p bytes, or at the first illegal
character.  Legal characters include any digit in the given base and, if
permitted by flags, underscores in restricted positions. It returns in
*len_p the actual number of bytes parsed.  If it stopped parsing early,
it raises a warning unless the caller has set the PERL_SCAN_SILENT_ILLDIGIT
bit in *flags.  The flag is cleared if no illegal character is found,
otherwise it will remain set on output.

If the resultant integer won't fit in a UV, UV_MAX is returned, and *flags
will contain the PERL_SCAN_NUMBER_OVERFLOWED bit. If 'approximation' is not
NULL, an NV approximation to the full integer will be placed into
*approximation.  And for bases 2, 8, 16, it raises a warning unless the
caller has set the PERL_SCAN_SILENT_OVERFLOW bit in *flags.

Note that *approximation is not changed unless overflow occurs.

For non-base10 operations, by default, a warning is raised for numbers
that don't overflow but exceed 32 bits in width.  This is suppressed if
the caller has set the PERL_SCAN_SILENT_NON_PORTABLE bit in *flags.

The function can silently accept (and otherwise ignore) underscores as well as
digits if the caller has set the PERL_SCAN_ALLOW_UNDERSCORES bit in *flags.
These are a single underscore between any two digits, and additionally an
initial underscore.

The function takes great care to make any overflowing approximation as
accurate as possible given the platform's limitations.

Attention has been paid to maximizing performance, but some compromises
have been made because it is the unification of grok_bin, grok_oct,
grok_hex and grok_decimal (if that existed).  The unification was done
because over time, patches had been applied to one or another of the
individual functions, causing them to drift apart.  Another solution
would be to have a regen script that starts with a single template and
customizes each one.  Here are the compromises that could matter.

=over

=item *

Each digit calculation uses XDIGIT_VALUE(), which, to accomodate hex values,
has extra bit operations not otherwise needed.  This macro replaces a
subtraction with 2 shifts, 2 additions, and 3 masks

=item *

To accommodate base 10, each digit calculation uses an integer multiply and an
addition instead of a bitwise shift and 'or'.

=item *

The main switch() statement could have more case statements for non-hex bases.

=back

There is a special mode that functions as an alternative to overflowing.  It
is triggered by the caller setting PERL_SCAN_DISCARD_INSTEAD_OF_OVERFLOW into
*flags.  Should overflow otherwise occur, subsequent digits are instead simply
discarded, while rounding the result towards even.  *approximation is not
changed if this flag is set.

=over 3

 UV       grok_uint_by_base(      const char * const start,
                                  STRLEN *len_p, I32 *flags,
                                  NV *approximation,
                                  uint_fast8_t base,
                                  const U32 lookup_bit,
                                  uint_fast8_t offset)
 UV  Perl_grok_uint_by_base(pTHX_ const char * const start,
                                  STRLEN *len_p, I32 *flags,
                                  NV *approximation,
                                  uint_fast8_t base,
                                  const U32 lookup_bit,
                                  uint_fast8_t offset)

=back

=back

=for hackers
Declared at embed.fnc, line 1529; documented at numeric.c, line 327

=over 4

=item C<isEVEN>

=item C<isODD>
X<isEVEN>X<isODD>

These return a boolean as to whether or not the integer value given by the
argument is even or odd, respectively.

=over 3

 bool  isEVEN(UV a)
 bool  isODD (UV a)

=back

=back

=for hackers
isEVEN declared at handy.h, line 339; all in group documented at handy.h, line 339
isODD declared at handy.h, line 340

=over 4

=item C<isinfnansv>
X<isinfnansv>

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

Note that this always accepts trailing garbage (similar to C<grok_number_flags>
with C<PERL_SCAN_TRAILING>), so C<"inferior"> and C<"NAND gates"> will
return true.

=over 3

 bool       isinfnansv(      SV *sv)
 bool  Perl_isinfnansv(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 1875; documented at numeric.c, line 2089

=over 4

=item C<isODD*>

Described under C<L</isEVEN>>

=back

=over 4

=item C<S_perl_hash_siphash_1_3>
X<S_perl_hash_siphash_1_3>

Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.

Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 32 bit hash.

The following code should return 0x2976B3A1

    char seed[] = "Call me Ishmael.";
    char in[] = "It is not down on any map; true places never are.";
    U32 hash = S_perl_hash_siphash_1_3(
                (const U8*)seed, (const U8*)in, sizeof(in)-1);

=over 3

 U64  S_perl_hash_siphash_1_3(const unsigned char * const seed,
                              const unsigned char *in,
                              const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 106

=over 4

=item C<S_perl_hash_siphash_1_3_with_state>
X<S_perl_hash_siphash_1_3_with_state>

Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.

Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 32 bit hash.

The following code should return 0x2976B3A1

    U8 state[32];
    char seed[] = "Call me Ishmael.";
    S_perl_siphash_seed_state((const U8*)seed, state);

    char in[] = "It is not down on any map; true places never are.";
    U32 hash = S_perl_hash_siphash_1_3_with_state(
                state, (const U8*)in, sizeof(in)-1);

=over 3

 U32  S_perl_hash_siphash_1_3_with_state(
                               const unsigned char * const state,
                                const unsigned char *in,
                                const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 68

=over 4

=item C<S_perl_hash_siphash_1_3_with_state_64>
X<S_perl_hash_siphash_1_3_with_state_64>

Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.

Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 64 bit hash.

The following code should return 0xB70339FD9E758A5C

    U8 state[32];
    char seed[] = "Call me Ishmael.";
    S_perl_siphash_seed_state((const U8*)seed, state);

    char in[] = "It is not down on any map; true places never are.";
    U64 hash = S_perl_hash_siphash_1_3_with_state_64(
                state, (const U8*)in, sizeof(in)-1);

=over 3

 U64  S_perl_hash_siphash_1_3_with_state_64(
                               const unsigned char * const state,
                                const unsigned char *in,
                                const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 47

=over 4

=item C<S_perl_hash_siphash_1_3_64>
X<S_perl_hash_siphash_1_3_64>

Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.

Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 64 bit hash.

The following code should return 0xB70339FD9E758A5C

    char seed[] = "Call me Ishmael.";
    char in[] = "It is not down on any map; true places never are.";
    U64 hash = S_perl_hash_siphash_1_3_64(
                (const U8*)seed, (const U8*)in, sizeof(in)-1);

=over 3

 U64  S_perl_hash_siphash_1_3_64(const unsigned char * const seed,
                                 const unsigned char *in,
                                 const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 89

=over 4

=item C<S_perl_hash_siphash_2_4>
X<S_perl_hash_siphash_2_4>

Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.

Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 32 bit hash.

The following code should return 0x6421D9AA

    char seed[] = "Call me Ishmael.";
    char in[] = "It is not down on any map; true places never are.";
    U32 hash = S_perl_hash_siphash_2_4(
                (const U8*)seed, (const U8*)in, sizeof(in)-1);

=over 3

 U32  S_perl_hash_siphash_2_4(const unsigned char * const seed,
                              const unsigned char *in,
                              const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 182

=over 4

=item C<S_perl_hash_siphash_2_4_with_state>
X<S_perl_hash_siphash_2_4_with_state>

Implements the variant of Siphash which performs 2 round function
per block, and 4 as part of the finalizer.

Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 32 bit hash.

The following code should return 0x6421D9AA

    U8 state[32];
    char seed[] = "Call me Ishmael.";
    S_perl_siphash_seed_state((const U8*)seed, state);

    char in[] = "It is not down on any map; true places never are.";
    U32 hash = S_perl_hash_siphash_2_4_with_state(
                state, (const U8*)in, sizeof(in)-1);

=over 3

 U32  S_perl_hash_siphash_2_4_with_state(
                               const unsigned char * const state,
                                const unsigned char *in,
                                const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 144

=over 4

=item C<S_perl_hash_siphash_2_4_with_state_64>
X<S_perl_hash_siphash_2_4_with_state_64>

Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.

Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 64 bit hash.

The following code should return 0x1E84CF1D7AA516B7

    U8 state[32];
    char seed[] = "Call me Ishmael.";
    S_perl_siphash_seed_state((const U8*)seed, state);

    char in[] = "It is not down on any map; true places never are.";
    U64 hash = S_perl_hash_siphash_2_4_with_state_64(
                state, (const U8*)in, sizeof(in)-1);

=over 3

 U64  S_perl_hash_siphash_2_4_with_state_64(
                               const unsigned char * const state,
                                const unsigned char *in,
                                const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 123

=over 4

=item C<S_perl_hash_siphash_2_4_64>
X<S_perl_hash_siphash_2_4_64>

Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.

Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 64 bit hash.

The following code should return 0x1E84CF1D7AA516B7

    char seed[] = "Call me Ishmael.";
    char in[] = "It is not down on any map; true places never are.";
    U64 hash = S_perl_hash_siphash_2_4_64(
                (const U8*)seed, (const U8*)in, sizeof(in)-1);

=over 3

 U64  S_perl_hash_siphash_2_4_64(const unsigned char * const seed,
                                 const unsigned char *in,
                                 const STRLEN inlen
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 165

=over 4

=item C<S_perl_siphash_seed_state>
X<S_perl_siphash_seed_state>

Takes a 16 byte seed and converts it into a 32 byte state buffer. The
contents of state_buf will be overwritten.

If you need to hash a lot of things, then you can use this to process
the seed once, and then reuse the state over and over.

The siphash functions which take a seed argument will call this function
implicitly every time they are used. Those which take a state argument
require the seed to be converted into a state before they are used.

See the various _with_state siphash functions for a usage example.

=over 3

 void  S_perl_siphash_seed_state(
                            const unsigned char * const seed_buf,
                             unsigned char * state_buf
)

=back

=back

=for hackers
Declared and documented at perl_siphash.h, line 31

=head1 Optrees
X<OP_LVALUE_NO_CROAK>

=over 4

=item C<new_block_statement>
X<new_block_statement>

Returns a C<OP *> representing block as statement.
Block is a loop that happens once.

Available since: v5.44

=over 3

 OP *       new_block_statement(      OP *block, OP *cont)
 OP *  Perl_new_block_statement(pTHX_ OP *block, OP *cont)

=back

=back

=for hackers
Declared at embed.fnc, line 2398; documented at op.c, line 4805

=over 4

=item C<newATTRSUB_x>
X<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, C<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 C<PL_compcv> object, but will not necessarily be so.

If C<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 S<C<sub foo ($$);>>.  If C<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 C<PL_compcv>.  The code is not expected to include a C<leavesub> or
C<leavesublv> op; this function will add such an op.  C<block> is consumed
by this function and will become part of the constructed subroutine.

C<proto> specifies the subroutine's prototype, unless one is supplied
as an attribute (see below).  If C<proto> is null, then the subroutine
will not have a prototype.  If C<proto> is non-null, it must point to a
C<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 C<proto>, but in that case C<proto> should
preferably be null.  In any case, C<proto> is consumed by this function.

C<attrs> supplies attributes to be applied the subroutine.  A handful of
attributes take effect by built-in means, being applied to C<PL_compcv>
immediately when seen.  Other attributes are collected up and attached
to the subroutine by this route.  C<attrs> may be null to supply no
attributes, or point to a C<const> op for a single attribute, or point
to a C<list> op whose children apart from the C<pushmark> are C<const>
ops for one or more attributes.  Each C<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.  C<attrs> is consumed by
this function.

If C<o_is_gv> is false and C<o> is null, then the subroutine will
be anonymous.  If C<o_is_gv> is false and C<o> is non-null, then C<o>
must point to a C<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 C<o_is_gv> is true, then C<o>
doesn't point to an C<OP> at all, but is instead a cast pointer to a C<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 C<BEGIN> or
C<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 C<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 C<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.

=over 3

 CV *       newATTRSUB_x(      I32 floor, OP *o, OP *proto,
                               OP *attrs, OP *block, bool o_is_gv)
 CV *  Perl_newATTRSUB_x(pTHX_ I32 floor, OP *o, OP *proto,
                               OP *attrs, OP *block, bool o_is_gv)

=back

=back

=for hackers
Declared at embed.fnc, line 2381; documented at op.c, line 11433

=over 4

=item C<newFORM>
X<newFORM>

Constructs, checks, and returns a format op.

=over 3

 void       newFORM(      I32 floor, OP *o, OP *block)
 void  Perl_newFORM(pTHX_ I32 floor, OP *o, OP *block)

=back

=back

=for hackers
Declared at embed.fnc, line 2419; documented at op.c, line 12633

=over 4

=item C<newMYSUB>
X<newMYSUB>

Construct a Perl lexical subroutine, also performing some surrounding jobs, and
returning a pointer to the constructed subroutine.

Similar in action to L<perlintern/C<newATTRSUB_x>>.

=over 3

 CV *       newMYSUB(      I32 floor, OP *o, OP *proto, OP *attrs,
                           OP *block)
 CV *  Perl_newMYSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs,
                           OP *block)

=back

=back

=for hackers
Declared at embed.fnc, line 2467; documented at op.c, line 11062

=over 4

=item C<newXS_len_flags>
X<newXS_len_flags>

Construct an XS subroutine, also performing some surrounding jobs.

The subroutine will have the entry point C<subaddr>.  It will have
the prototype specified by the nul-terminated string C<proto>, or
no prototype if C<proto> is null.  The prototype string is copied;
the caller can mutate the supplied string afterwards.  If C<filename>
is non-null, it must be a nul-terminated filename, and the subroutine
will have its C<CvFILE> set accordingly.  By default C<CvFILE> is set to
point directly to the supplied string, which must be static.  If C<flags>
has the C<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 C<name> is null then the subroutine will be anonymous, with its
C<CvGV> referring to an C<__ANON__> glob.  If C<name> is non-null then the
subroutine will be named accordingly, referenced by the appropriate glob.
C<name> is a string of length C<len> bytes giving a sigilless symbol name,
in UTF-8 if C<flags> has the C<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 C<gv_fetchpvn_flags>.  C<flags> may contain
flag bits understood by C<gv_fetchpvn_flags> with the same meaning as
they have there, such as C<GV_ADDWARN>.  The symbol is always added to
the stash if necessary, with C<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 C<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 C<const_svp>.  (Note that the call to
this function doesn't make the new subroutine C<CvCONST> in any case;
that is left to the caller.)  If C<const_svp> is null then it indicates
that the new subroutine will not become a constant.  If C<const_svp>
is non-null then it indicates that the new subroutine will become a
constant, and it points to an C<SV*> that provides the constant value
that the subroutine will have.

If the subroutine has one of a few special names, such as C<BEGIN> or
C<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 C<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 C<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 C<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.

=over 3

 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)
 CV *  Perl_newXS_len_flags(pTHX_ const char *name, STRLEN len,
                                  XSUBADDR_t subaddr,
                                  const char * const filename,
                                  const char * const proto,
                                  SV ** const_svp, U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 2596; documented at op.c, line 12437

=over 4

=item C<op_lvalue_flags>
X<op_lvalue_flags>

This is a non-API lower-level interface to L<perlapi/C<op_lvalue>>, whose
flags param has these bits:

=over

=item OP_LVALUE_NO_CROAK

return rather than croaking on error

=back

=over 3

 OP *  Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 2646; documented at op.c, line 3172

=over 4

=item C<op_refcnt_lock>
X<op_refcnt_lock>

Implements the C<OP_REFCNT_LOCK> macro which you should use instead.

=over 3

 void       op_refcnt_lock()
 void  Perl_op_refcnt_lock(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2655; documented at op.c, line 1544

=over 4

=item C<op_refcnt_unlock>
X<op_refcnt_unlock>

Implements the C<OP_REFCNT_UNLOCK> macro which you should use instead.

=over 3

 void       op_refcnt_unlock()
 void  Perl_op_refcnt_unlock(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 2656; documented at op.c, line 1562

=over 4

=item C<package>
X<package>

Function sets current stash name and if $version is not NULL, sets it as C<$VERSION>.

It combines former C<package> and C<package_version> into single call.

=over 3

 void       package(      OP *name, OP *version)
 void  Perl_package(pTHX_ OP *name, OP *version)

=back

=back

=for hackers
Declared at embed.fnc, line 2669; documented at op.c, line 8442

=over 4

=item C<traverse_op_tree>
X<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.

=over 3

 OP *  traverse_op_tree(OP *top, OP *o)

=back

=back

=for hackers
Declared at embed.fnc, line 5285; documented at peep.c, line 1204

=head1 Pack and Unpack

There are currently no internal API items in Pack and Unpack

=head1 Pad Data Structures

=over 4

=item C<CX_CURPAD_SAVE>
X<CX_CURPAD_SAVE>

Save the current pad in the given context block structure.

=over 3

 void  CX_CURPAD_SAVE(struct context)

=back

=back

=for hackers
Declared and documented at pad.h, line 448

=over 4

=item C<CX_CURPAD_SV>
X<CX_CURPAD_SV>

Access the SV at offset C<po> in the saved current pad in the given
context block structure (can be used as an lvalue).

=over 3

 SV *  CX_CURPAD_SV(struct context, PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 451

=over 4

=item C<PAD_BASE_SV>
X<PAD_BASE_SV>

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

=over 3

 SV *  PAD_BASE_SV(PADLIST padlist, PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 295

=over 4

=item C<PAD_CLONE_VARS>
X<PAD_CLONE_VARS>

Clone the state variables associated with running and compiling pads.

=over 3

 void  PAD_CLONE_VARS(PerlInterpreter *proto_perl,
                      CLONE_PARAMS* param)

=back

=back

=for hackers
Declared and documented at pad.h, line 508

=over 4

=item C<PAD_COMPNAME_FLAGS>
X<PAD_COMPNAME_FLAGS>

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

=over 3

 U32  PAD_COMPNAME_FLAGS(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 463

=over 4

=item C<PAD_COMPNAME_GEN>
X<PAD_COMPNAME_GEN>

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

=over 3

 STRLEN  PAD_COMPNAME_GEN(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 479

=over 4

=item C<PAD_COMPNAME_GEN_set>
X<PAD_COMPNAME_GEN_set>

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

=over 3

 STRLEN  PAD_COMPNAME_GEN_set(PADOFFSET po, int gen)

=back

=back

=for hackers
Declared and documented at pad.h, line 483

=over 4

=item C<PAD_COMPNAME_OURSTASH>
X<PAD_COMPNAME_OURSTASH>

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

=over 3

 HV *  PAD_COMPNAME_OURSTASH(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 475

=over 4

=item C<PAD_COMPNAME_PV>
X<PAD_COMPNAME_PV>

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

=over 3

 char *  PAD_COMPNAME_PV(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 467

=over 4

=item C<PAD_COMPNAME_TYPE>
X<PAD_COMPNAME_TYPE>

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

=over 3

 HV *  PAD_COMPNAME_TYPE(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 471

=over 4

=item C<PAD_RESTORE_LOCAL>
X<PAD_RESTORE_LOCAL>

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

=over 3

 void  PAD_RESTORE_LOCAL(PAD *opad)

=back

=back

=for hackers
Declared and documented at pad.h, line 317

=over 4

=item C<PAD_SAVE_LOCAL>
X<PAD_SAVE_LOCAL>

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

=over 3

 void  PAD_SAVE_LOCAL(PAD *opad, PAD *npad)

=back

=back

=for hackers
Declared and documented at pad.h, line 313

=over 4

=item C<PAD_SAVE_SETNULLPAD>
X<PAD_SAVE_SETNULLPAD>

Save the current pad then set it to null.

=over 3

 void  PAD_SAVE_SETNULLPAD()

=back

=back

=for hackers
Declared and documented at pad.h, line 310

=over 4

=item C<PAD_SET_CUR>
X<PAD_SET_CUR>

Set the current pad to be pad C<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);

=over 3

 void  PAD_SET_CUR(PADLIST padlist, I32 n)

=back

=back

=for hackers
Declared and documented at pad.h, line 298

=over 4

=item C<PAD_SET_CUR_NOSAVE>
X<PAD_SET_CUR_NOSAVE>

like PAD_SET_CUR, but without the save

=over 3

 void  PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)

=back

=back

=for hackers
Declared and documented at pad.h, line 307

=over 4

=item C<PAD_SETSV>
X<PAD_SETSV>

Set the slot at offset C<po> in the current pad to C<sv>

=over 3

 SV *  PAD_SETSV(PADOFFSET po, SV* sv)

=back

=back

=for hackers
Declared and documented at pad.h, line 283

=over 4

=item C<PAD_SV>
X<PAD_SV>

Get the value at offset C<po> in the current pad

=over 3

 SV *  PAD_SV(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 286

=over 4

=item C<PAD_SVl>
X<PAD_SVl>

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

=over 3

 SV *  PAD_SVl(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 289

=over 4

=item C<PadnameIsFIELD>
X<PadnameIsFIELD>

Whether this is a "field" variable.  PADNAMEs where this is true will
have additional information available via C<PadnameFIELDINFO>.

=over 3

 bool  PadnameIsFIELD(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 265

=over 4

=item C<PadnameIsOUR>
X<PadnameIsOUR>

Whether this is an "our" variable.

=over 3

 bool  PadnameIsOUR(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 252

=over 4

=item C<PadnameIsSTATE>
X<PadnameIsSTATE>

Whether this is a "state" variable.

=over 3

 bool  PadnameIsSTATE(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 262

=over 4

=item C<PadnameOURSTASH>
X<PadnameOURSTASH>

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

=over 3

 HV *  PadnameOURSTASH(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 255

=over 4

=item C<PadnameOUTER>
X<PadnameOUTER>

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

=over 3

 bool  PadnameOUTER(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 258

=over 4

=item C<PadnameTYPE>
X<PadnameTYPE>

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

=over 3

 HV *  PadnameTYPE(PADNAME * pn)

=back

=back

=for hackers
Declared and documented at pad.h, line 269

=over 4

=item C<SAVECLEARSV>
X<SAVECLEARSV>

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

=over 3

 void  SAVECLEARSV(SV **svp)

=back

=back

=for hackers
Declared and documented at pad.h, line 192

=over 4

=item C<SAVECOMPPAD>
X<SAVECOMPPAD>

save C<PL_comppad> and C<PL_curpad>

=over 3

 void  SAVECOMPPAD()

=back

=back

=for hackers
Declared and documented at pad.h, line 196

=over 4

=item C<SAVEPADSVANDMORTALIZE>
X<SAVEPADSVANDMORTALIZE>

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

=over 3

 void  SAVEPADSVANDMORTALIZE(PADOFFSET po)

=back

=back

=for hackers
Declared and documented at pad.h, line 185

=head1 Password and Group access

There are currently no internal API items in Password and Group access

=head1 Paths to system commands

There are currently no internal API items in Paths to system commands

=head1 Prototype information

There are currently no internal API items in Prototype information

=head1 Reference-counted stack manipulation

There are currently no internal API items in Reference-counted stack manipulation

=head1 REGEXP Functions
X<RX_OFFSp>

=over 4

=item C<regnode>

Described in L<perlreguts>.

=back

=for hackers
Documented at pod/perlreguts.pod, line 114

=head1 Reports and Formats

There are currently no internal API items in Reports and Formats

=head1 Signals

There are currently no internal API items in Signals

=head1 Site configuration

There are currently no internal API items in Site configuration

=head1 Sockets configuration values

There are currently no internal API items in Sockets configuration values

=head1 Source Filters

=over 4

=item C<parse_ident_msg>
X<parse_ident_msg>

Parse the string pointed to by '*s' (whose upper bound is 's_end') looking for
a normal identifier whose first character matches \p{XID_Start} followed by any
number of characters which match \p{XID_Continue}.

It returns a pointer to the first character in 's' beyond the next such
identifier, or NULL if a serious error was found in the parsed string.
Currently the only such serious error is that the identifier is too long for
the perl interpreter to handle (the maximum is guaranteed to be at least 255
characters).

If 'error_detail' is not NULL, when a serious error is found, it creates a
mortal hash containing details of the error, as follows:

=over 3

 char *       parse_ident_msg(      const char *s,
                                    const char *end, bool is_utf8,
                                    HV **failure_details,
                                    U32 flags)
 char *  Perl_parse_ident_msg(pTHX_ const char *s,
                                    const char *end, bool is_utf8,
                                    HV **failure_details,
                                    U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 2739; documented at toke.c, line 10889

=head1 Stack Manipulation Macros

=over 4

=item C<djSP>
X<djSP>

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

=over 3

   djSP;

=back

=back

=for hackers
Declared and documented at pp.h, line 82

=over 4

=item C<LVRET>
X<LVRET>

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

=back

=for hackers
Declared and documented at pp.h, line 714

=over 4

=item C<save_alloc>
X<save_alloc>

Implements L<perlapi/C<SSNEW>> and kin, which should be used instead of this
function.

=over 3

 SSize_t       save_alloc(      SSize_t size, I32 pad)
 SSize_t  Perl_save_alloc(pTHX_ SSize_t size, I32 pad)

=back

=back

=for hackers
Declared at embed.fnc, line 3137; documented at scope.c, line 1142

=head1 String Handling

See also C<L</Unicode Support>>.


=over 4

=item C<delimcpy_no_escape>
X<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, C<delim>.  The source
is the bytes between S<C<from> and C<from_end> - 1>.  Similarly, the dest is
C<to> up to C<to_end>.

The number of bytes copied is written to C<*retlen>.

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

If there is room in the destination available after the copy, an extra
terminating safety C<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
S<C<to_end> - C<to>> is written to C<*retlen>, and as much of the source as
fits will be written to the destination.  Not having room for the safety C<NUL>
is not considered an error.

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 1201; documented at util.c, line 598

=over 4

=item C<quadmath_format_needed>
X<quadmath_format_needed>

C<quadmath_format_needed()> returns true if the C<format> string seems to
contain at least one non-Q-prefixed C<%[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 B<should> in theory be processed
with C<quadmath_snprintf()>, but in case there is more than one such
format specifier (see L</quadmath_format_valid>), and if there is
anything else beyond that one (even just a single byte), they
B<cannot> be processed because C<quadmath_snprintf()> is very strict,
accepting only one format spec, and nothing else.
In this case, the code should probably fail.

=over 3

 bool       quadmath_format_needed(const char *format)
 bool  Perl_quadmath_format_needed(const char *format)

=back

=back

=for hackers
Declared at embed.fnc, line 6770; documented at util.c, line 5170

=over 4

=item C<quadmath_format_valid>
X<quadmath_format_valid>

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

C<quadmath_format_valid()> checks that the intended single spec looks
sane: begins with C<%>, has only one C<%>, ends with C<[efgaEFGA]>,
and has C<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 L</quadmath_format_needed>.

=over 3

 bool       quadmath_format_valid(const char *format)
 bool  Perl_quadmath_format_valid(const char *format)

=back

=back

=for hackers
Declared at embed.fnc, line 6772; documented at util.c, line 5132

=head1 SV Flags

=over 4

=item C<SVt_INVLIST>
X<SVt_INVLIST>

Type flag for scalars.  See L<perlapi/svtype>.

=back

=for hackers
Declared and documented at sv.h, line 101

=head1 SV Handling
X<SV_FORCE_OVERLOAD>X<SV_GMAGIC>X<SV_SKIP_OVERLOAD>

=over 4

=item C<PL_Sv>
X<PL_Sv>

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

B<BUT BEWARE>, if this is used in a situation where something that is using it
is in a call stack with something else that is using it, this variable would
get zapped, leading to hard-to-diagnose errors.

These days using an inline function is generally preferred instead.

=back

=for hackers
Declared and documented at intrpvar.h, line 232

=over 4

=item C<sv_add_arena>
X<sv_add_arena>

=for_apidoc_flag SVf_FAKE

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

=over 3

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

=back

=back

=for hackers
Declared at embed.fnc, line 6190; documented at sv.c, line 333

=over 4

=item C<sv_clean_all>
X<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.

=over 3

 SSize_t       sv_clean_all()
 SSize_t  Perl_sv_clean_all(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3383; documented at sv.c, line 589

=over 4

=item C<sv_clean_objs>
X<sv_clean_objs>

Attempt to destroy all objects not yet freed.

=over 3

 void       sv_clean_objs()
 void  Perl_sv_clean_objs(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3385; documented at sv.c, line 539

=over 4

=item C<sv_free_arenas>
X<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.

=over 3

 void       sv_free_arenas()
 void  Perl_sv_free_arenas(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3461; documented at sv.c, line 703

=over 4

=item C<sv_grow>
X<sv_grow>

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

=over 3

 char *       sv_grow(      SV * const sv, STRLEN newlen)
 char *  Perl_sv_grow(pTHX_ SV * const sv, STRLEN newlen)

=back

=back

=for hackers
Declared at embed.fnc, line 3467; documented at sv.c, line 1394

=over 4

=item C<sv_grow_fresh>
X<sv_grow_fresh>

A cut-down version of sv_grow intended only for when sv is a freshly-minted
SVt_PV, SVt_PVIV, SVt_PVNV, or SVt_PVMG. i.e. sv has the default flags, has
never been any other type, and does not have an existing string. Basically,
just assigns a char buffer and returns a pointer to it.

=over 3

 char *       sv_grow_fresh(      SV * const sv, STRLEN newlen)
 char *  Perl_sv_grow_fresh(pTHX_ SV * const sv, STRLEN newlen)

=back

=back

=for hackers
Declared at embed.fnc, line 3469; documented at sv.c, line 1488

=over 4

=item C<sv_newref>
X<sv_newref>

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

=over 3

 SV *       sv_newref(      SV * const sv)
 SV *  Perl_sv_newref(pTHX_ SV * const sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3520; documented at sv.c, line 7821

=over 4

=item C<sv_numcmp_common>
X<sv_numcmp_common>

Handles the common parts of the L<perlapi/sv_numeq>, sv_numne,
sv_numlt, sv_numle, sv_numge, sv_numgt, sv_numcmp APIs.

C<method> should be the C<*_amg> constant for the operator being
handled, such as C<eq_amg> for numeric equality.

C<flags> takes the same flags as the numeric comparison APIs.

This includes:

=over

=item *

treating possible NULL C<*sv1> and C<*sv2> arguments as undef.

=item *

calling get magic

=item *

handling the pain of overloading, including numericizing the SVs if
there is no numeric overload, but there is a numeric "0+" overload.

=back

If there is operator overloading this function will populate
C<*result> with the SV returned by the overloading and return true.
The caller will need to convert this to an integer for sv_numcmp() or
to bool for the rest of the APIs.

If there is no operator overloading, this function will return true.
Before returning it will convert C<*sv1> and C<*sv2> to numbers if
they are references so do_cmp() can be used safely.

=over 3

 bool  sv_numcmp_common(SV **sv1, SV **sv2, const U32 flags,
                        int method, SV **result)

=back

=back

=for hackers
Declared at embed.fnc, line 6197; documented at sv.c, line 8776

=over 4

=item C<sv_pv>
X<sv_pv>

Use the C<SvPV_nolen> macro instead

=over 3

 char *       sv_pv(      SV *sv)
 char *  Perl_sv_pv(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3584; documented at sv.h, line 2271

=over 4

=item C<sv_pvbyte>
X<sv_pvbyte>

Use C<SvPVbyte_nolen> instead.

=over 3

 char *       sv_pvbyte(      SV *sv)
 char *  Perl_sv_pvbyte(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3587; documented at sv.h, line 2289

=over 4

=item C<sv_pvbyten_force>
X<sv_pvbyten_force>

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

=over 3

 char *       sv_pvbyten_force(      SV * const sv,
                                     STRLEN * const lp)
 char *  Perl_sv_pvbyten_force(pTHX_ SV * const sv,
                                     STRLEN * const lp)

=back

=back

=for hackers
Declared at embed.fnc, line 3592; documented at sv.c, line 11372

=over 4

=item C<sv_pvn_force>
X<sv_pvn_force>

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

=over 3

 char *       sv_pvn_force(      SV *sv, STRLEN *lp)
 char *  Perl_sv_pvn_force(pTHX_ SV *sv, STRLEN *lp)

=back

=back

=for hackers
Declared at embed.fnc, line 3611; documented at sv.c, line 11303

=over 4

=item C<sv_pvutf8>
X<sv_pvutf8>

Use the C<SvPVutf8_nolen> macro instead

=over 3

 char *       sv_pvutf8(      SV *sv)
 char *  Perl_sv_pvutf8(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3620; documented at sv.h, line 2280

=over 4

=item C<sv_pvutf8n_force>
X<sv_pvutf8n_force>

The backend for the C<SvPVutf8x_force> macro.  Always use the macro
instead.

=over 3

 char *       sv_pvutf8n_force(      SV * const sv,
                                     STRLEN * const lp)
 char *  Perl_sv_pvutf8n_force(pTHX_ SV * const sv,
                                     STRLEN * const lp)

=back

=back

=for hackers
Declared at embed.fnc, line 3625; documented at sv.c, line 11392

=over 4

=item C<sv_tainted>
X<sv_tainted>

Test an SV for taintedness.  Use C<SvTAINTED> instead.

=over 3

 bool       sv_tainted(      SV * const sv)
 bool  Perl_sv_tainted(pTHX_ SV * const sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3771; documented at sv.c, line 11936

=over 4

=item C<sv_true>
X<sv_true>

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

=over 3

 I32       sv_true(      SV * const sv)
 I32  Perl_sv_true(pTHX_ SV * const sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3773; documented at sv.c, line 11265

=over 4

=item C<sv_untaint>
X<sv_untaint>

Untaint an SV.  Use C<SvTAINTED_off> instead.

=over 3

 void       sv_untaint(      SV * const sv)
 void  Perl_sv_untaint(pTHX_ SV * const sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3790; documented at sv.c, line 11915

=over 4

=item C<sv_2bool>
X<sv_2bool>

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

=over 3

 bool       sv_2bool(      SV * const sv)
 bool  Perl_sv_2bool(pTHX_ SV * const sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3339; documented at sv.c, line 3411

=over 4

=item C<sv_2bool_flags>
X<sv_2bool_flags>

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

=over 3

 bool       sv_2bool_flags(      SV *sv, I32 flags)
 bool  Perl_sv_2bool_flags(pTHX_ SV *sv, I32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 3340; documented at sv.c, line 3417

=over 4

=item C<sv_2num_flags>

=item C<sv_2num>
X<sv_2num>X<sv_2num_flags>

NOTE: C<sv_2num_flags> is B<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.

For sv_2num_flags() you can set the following flags:

=over

=item *

C<SV_SKIP_OVERLOAD> - avoid any numeric context overloading.

=item *

C<SV_FORCE_OVERLOAD> - use numeric context overloading even if
disabled in hints by C<no overloading;>.

=back

=over 3

 SV *       sv_2num_flags(      SV * const sv, int flags)
 SV *  Perl_sv_2num_flags(pTHX_ SV * const sv, int flags)
 SV *       sv_2num      (      SV * const sv)
 SV *  Perl_sv_2num      (pTHX_ SV * const sv)

=back

=back

=for hackers
sv_2num_flags declared at embed.fnc, line 3534; all in group documented at sv.c, line 2789
sv_2num declared at embed.fnc, line 3523

=over 4

=item C<sv_2pv_nolen>
X<sv_2pv_nolen>

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

=over 3

 char *       sv_2pv_nolen(      SV *sv)
 char *  Perl_sv_2pv_nolen(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3617; documented at sv.h, line 2330

=over 4

=item C<sv_2pvbyte_nolen>
X<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 C<SvPVbyte_nolen> macro.

=over 3

 char *       sv_2pvbyte_nolen(      SV *sv)
 char *  Perl_sv_2pvbyte_nolen(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3599; documented at sv.h, line 2341

=over 4

=item C<sv_2pvutf8_nolen>
X<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 C<SvPVutf8_nolen> macro.

=over 3

 char *       sv_2pvutf8_nolen(      SV *sv)
 char *  Perl_sv_2pvutf8_nolen(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3632; documented at sv.h, line 2354

=over 4

=item C<SvTHINKFIRST>
X<SvTHINKFIRST>

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

For example, if your scalar is a reference and you want to modify the C<SvIVX>
slot, you can't just do C<SvROK_off>, as that will leak the referent.

This is used internally by various sv-modifying functions, such as
C<sv_setsv>, C<sv_setiv> and C<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.

C<SvTHINKFIRST> sometimes produces false positives.  In those cases
C<sv_force_normal> does nothing.

=over 3

 U32  SvTHINKFIRST(SV *sv)

=back

=back

=for hackers
Declared and documented at sv.h, line 1288

=head1 Tainting

=over 4

=item C<sv_taint>
X<sv_taint>

Taint an SV.  Use C<SvTAINTED_on> instead.

=over 3

 void       sv_taint(      SV *sv)
 void  Perl_sv_taint(pTHX_ SV *sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3770; documented at sv.h, line 1785

=over 4

=item C<TAINT>
X<TAINT>

If we aren't in taint checking mode, do nothing;
otherwise indicate to L</C<TAINT_set>> and L</C<TAINT_PROPER>> that some
unspecified element is tainted.

=over 3

 void  TAINT

=back

=back

=for hackers
Declared and documented at perl.h, line 971

=over 4

=item C<TAINT_ENV>
X<TAINT_ENV>

Looks at several components of L<C<%ENV>|perlvar/%ENV> for taintedness, and
calls L</C<taint_proper>> if any are tainted.  The components it searches are
things like C<$PATH>.

=over 3

 void  TAINT_ENV()

=back

=back

=for hackers
Declared and documented at perl.h, line 986

=over 4

=item C<taint_env>
X<taint_env>

Implements the L</TAINT_ENV> macro, which you should generally use instead.

=over 3

 void       taint_env()
 void  Perl_taint_env(pTHX)

=back

=back

=for hackers
Declared at embed.fnc, line 3878; documented at taint.c, line 92

=over 4

=item C<TAINT_get>
X<TAINT_get>

Returns a boolean as to whether some element is tainted or not.

=over 3

 bool  TAINT_get

=back

=back

=for hackers
Declared and documented at perl.h, line 1003

=over 4

=item C<TAINT_IF>
X<TAINT_IF>

If C<c> evaluates to true, call L</C<TAINT>> to indicate that something is
tainted; otherwise do nothing.

=over 3

 void  TAINT_IF(bool c)

=back

=back

=for hackers
Declared and documented at perl.h, line 981

=over 4

=item C<TAINT_NOT>
X<TAINT_NOT>

Remove any taintedness previously set by, I<e.g.>, C<TAINT>.

=over 3

 void  TAINT_NOT

=back

=back

=for hackers
Declared and documented at perl.h, line 977

=over 4

=item C<TAINT_PROPER>
X<TAINT_PROPER>

If no element is tainted, do nothing;
otherwise output a message (containing C<s>) that indicates there is a
tainting violation.  If such violations are fatal, it croaks.

=over 3

 void  TAINT_PROPER(const char * s)

=back

=back

=for hackers
Declared and documented at perl.h, line 992

=over 4

=item C<taint_proper>
X<taint_proper>

Implements the L</TAINT_PROPER> macro, which you should generally use instead.

=over 3

 void       taint_proper(      const char *f,
                               const char * const s)
 void  Perl_taint_proper(pTHX_ const char *f,
                               const char * const s)

=back

=back

=for hackers
Declared at embed.fnc, line 3879; documented at taint.c, line 27

=over 4

=item C<TAINT_set>
X<TAINT_set>

If C<s> is true, L</C<TAINT_get>> returns true;
If C<s> is false, L</C<TAINT_get>> returns false;

=over 3

 void  TAINT_set(bool s)

=back

=back

=for hackers
Declared and documented at perl.h, line 998

=over 4

=item C<TAINT_WARN_get>
X<TAINT_WARN_get>

Returns false if tainting violations are fatal;
Returns true if they're just warnings

=over 3

 bool  TAINT_WARN_get

=back

=back

=for hackers
Declared and documented at perl.h, line 1015

=over 4

=item C<TAINT_WARN_set>
X<TAINT_WARN_set>

C<s> being true indicates L</C<TAINT_WARN_get>> should return that tainting
violations are just warnings

C<s> being false indicates L</C<TAINT_WARN_get>> should return that tainting
violations are fatal.

=over 3

 void  TAINT_WARN_set(bool s)

=back

=back

=for hackers
Declared and documented at perl.h, line 1020

=over 4

=item C<TAINTING_get>
X<TAINTING_get>

Returns a boolean as to whether taint checking is enabled or not.

=over 3

 bool  TAINTING_get

=back

=back

=for hackers
Declared and documented at perl.h, line 1007

=over 4

=item C<TAINTING_set>
X<TAINTING_set>

Turn taint checking mode off/on

=over 3

 void  TAINTING_set(bool s)

=back

=back

=for hackers
Declared and documented at perl.h, line 1011

=head1 Time

There are currently no internal API items in Time

=head1 Typedef names

There are currently no internal API items in Typedef names

=head1 Unicode Support

L<perlguts/Unicode Support> has an introduction to this API.

See also C<L</Character classification>>,
C<L</Character case changing>>,
and C<L</String Handling>>.
Various functions outside this section also work specially with
Unicode.  Search for the string "utf8" in this document.


=over 4

=item C<invlist_highest_range_start>
X<invlist_highest_range_start>

Returns the lowest code point of the highest range in the inversion list
given by its parameter.

This API has an ambiguity: it returns 0 either when the lowest such
point is actually 0 or when the list is empty.  If this distinction matters to
you, check for emptiness before calling this function.

=over 3

 UV  invlist_highest_range_start(SV * const invlist)

=back

=back

=for hackers
Declared at embed.fnc, line 5542; documented at invlist_inline.h, line 179

=over 4

=item C<invlist_lowest>
X<invlist_lowest>

Returns the lowest code point that matches an inversion list.

This API has an ambiguity, as it returns 0 under either the lowest is actually
0, or if the list is empty.  If this distinction matters to you, check for
emptiness before calling this function

=over 3

 UV  invlist_lowest(SV * const invlist)

=back

=back

=for hackers
Declared at embed.fnc, line 5546; documented at invlist_inline.h, line 371

=over 4

=item C<is_utf8_non_invariant_string>
X<is_utf8_non_invariant_string>

Returns TRUE if L<perlapi/is_utf8_invariant_string> returns FALSE for the first
C<len> bytes of the string C<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 C<L<perlapi/is_utf8_invariant_string>>.

=over 3

 bool       is_utf8_non_invariant_string(const U8 * const s,
                                         STRLEN len)
 bool  Perl_is_utf8_non_invariant_string(const U8 * const s,
                                         STRLEN len)

=back

=back

=for hackers
Declared at embed.fnc, line 4421; documented at inline.h, line 2204

=over 4

=item C<isSCRIPT_RUN>
X<isSCRIPT_RUN>

Returns a bool as to whether or not the sequence of bytes from C<s> up to but
not including C<send> form a "script run".  C<utf8_target> is true iff the
sequence starting at C<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.

C<*ret_script>, if C<ret_script> is not NULL, will on return of true
contain the script found, using the C<SCX_enum> typedef.  Its value will be
C<SCX_INVALID> if the function returns false.

If the sequence is empty, true is returned, but C<*ret_script> (if asked for)
will be C<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 C<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 C<SCX_Inherited> iff all the code points in it are
from the Inherited script.

Otherwise, the returned script will be C<SCX_Common> iff all the code points in
it are from the Inherited or Common scripts.

=over 3

 bool       isSCRIPT_RUN(      const U8 *s, const U8 *send,
                               const bool utf8_target)
 bool  Perl_isSCRIPT_RUN(pTHX_ const U8 *s, const U8 *send,
                               const bool utf8_target)

=back

=back

=for hackers
Declared at embed.fnc, line 4418; documented at regexec.c, line 11725

=over 4

=item C<UNI_DISPLAY_TR>
X<UNI_DISPLAY_TR>

This is an extra flag for L<perlapi/sv_uni_display> which is for internal use
only.  It displays an operand of the tr/// operation.  These operands have a
peculiar, deliberate UTF-8 malformation which this flag enables the proper
handling of.  It turns on ISPRINT and BACKSLASH as well.

=back

=for hackers
Declared and documented at utf8.c, line 4785

=over 4

=item C<utf8_to_uvuni>
X<utf8_to_uvuni>

C<B<DEPRECATED!>>  It is planned to remove C<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 C<s>
which is assumed to be in UTF-8 encoding; C<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.

If C<s> points to one of the detected malformations, and UTF8 warnings are
enabled, zero is returned and C<*retlen> is set (if C<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 C<*retlen>
is set (if C<retlen> isn't NULL) so that (S<C<s> + C<*retlen>>) is the
next possible position in C<s> that could begin a non-malformed character.
See L<perlapi/utf8n_to_uvchr> for details on when the REPLACEMENT CHARACTER is returned.

=over 3

 UV       utf8_to_uvuni(      const U8 *s, STRLEN *retlen)
 UV  Perl_utf8_to_uvuni(pTHX_ const U8 *s, STRLEN *retlen)

=back

=back

=for hackers
Declared at embed.fnc, line 4090; documented at mathoms.c, line 118

=over 4

=item C<utf8n_to_uvuni>
X<utf8n_to_uvuni>

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

Instead use L<perlapi/utf8_to_uv>, or rarely, L<perlapi/utf8_to_uv_flags>.

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 L<perlapi/C<utf8_to_uv>> or
L<perlapi/C<utf8_to_uv_flags>> to calculate the native code point, and then
convert to Unicode using L<perlapi/C<NATIVE_TO_UNI>>.

=over 3

 UV       utf8n_to_uvuni(      const U8 *s, STRLEN curlen,
                               STRLEN *retlen, U32 flags)
 UV  Perl_utf8n_to_uvuni(pTHX_ const U8 *s, STRLEN curlen,
                               STRLEN *retlen, U32 flags)

=back

=back

=for hackers
Declared at embed.fnc, line 4005; documented at mathoms.c, line 162

=over 4

=item C<uvoffuni_to_utf8_flags>
X<uvoffuni_to_utf8_flags>

THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
Instead, B<Almost all code should use L<perlapi/uv_to_utf8> or
L<perlapi/uv_to_utf8_flags>>.

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 L<perlapi/uv_to_utf8_flags>.

=over 3

 U8 *       uvoffuni_to_utf8_flags(      U8 *d, UV uv, UV flags)
 U8 *  Perl_uvoffuni_to_utf8_flags(pTHX_ U8 *d, UV uv, UV flags)

=back

=back

=for hackers
Declared at embed.fnc, line 4110; documented at utf8.h, line 143

=over 4

=item C<valid_utf8_to_uv>

=item C<valid_utf8_to_uvchr>
X<valid_utf8_to_uv>X<valid_utf8_to_uvchr>

These are synonymous.

These are like C<L<perlapi/utf8_to_uv>>, but should only be called when it is
known that the next character in the input UTF-8 string C<s> is well-formed
(I<e.g.>, it passes C<L<perlapi/isUTF8_CHAR>>.  Surrogates, non-character code
points, and non-Unicode code points are allowed.

The only use for these is that they should run slightly faster than
C<utf8_to_uv> because no error checking is done.

The C<_uv> form is slightly preferred so as to have a consistent spelling with
the other C<_uv> forms that are definitely preferred over the older and
problematic C<_uvchr> forms.

=over 3

 UV       valid_utf8_to_uv   (const U8 *s, STRLEN *retlen)
 UV  Perl_valid_utf8_to_uv   (const U8 *s, STRLEN *retlen)
 UV       valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
 UV  Perl_valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)

=back

=back

=for hackers
valid_utf8_to_uv declared at embed.fnc, line 4146; all in group documented at inline.h, line 1357
valid_utf8_to_uvchr declared at embed.fnc, line 4149

=over 4

=item C<variant_under_utf8_count>
X<variant_under_utf8_count>

This function looks at the sequence of bytes between C<s> and C<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 C<utf8> in their name, the input
to this function is NOT a UTF-8-encoded string.  The function name is slightly
I<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
C<L<perlapi/is_utf8_invariant_string>>
and
C<L<perlapi/is_utf8_invariant_string_loc>>,

=over 3

 Size_t  variant_under_utf8_count(const U8 * const s,
                                  const U8 * const e)

=back

=back

=for hackers
Declared at embed.fnc, line 4429; documented at inline.h, line 2122

=head1 Utility Functions

=over 4

=item C<my_popen_list>
X<my_popen_list>

Implementing function on some systems for PerlProc_popen_list()

=over 3

 PerlIO *       my_popen_list(      const char *mode, int n,
                                    SV **args)
 PerlIO *  Perl_my_popen_list(pTHX_ const char *mode, int n,
                                    SV **args)

=back

=back

=for hackers
Declared at embed.fnc, line 2323; documented at util.c, line 2444

=over 4

=item C<my_socketpair>
X<my_socketpair>

Emulates L<socketpair(2)> on systems that don't have it, but which do have
enough functionality for the emulation.

=over 3

 int       my_socketpair(int family, int type, int protocol,
                         int fd[2])
 int  Perl_my_socketpair(int family, int type, int protocol,
                         int fd[2])

=back

=back

=for hackers
Declared at embed.fnc, line 2333; documented at util.c, line 4403

=head1 Versioning

There are currently no internal API items in Versioning

=head1 Warning and Dieing


In all these calls, the C<U32 wI<n>> parameters are warning category
constants.  You can see the ones currently available in
L<warnings/Category Hierarchy>, just capitalize all letters in the names
and prefix them by C<WARN_>.  So, for example, the category C<void> used in a
perl program becomes C<WARN_VOID> when used in XS code and passed to one of
the calls below.


=over 4

=item C<deprecate>

=item C<deprecate_disappears_in>

=item C<deprecate_fatal_in>
X<deprecate>X<deprecate_disappears_in>X<deprecate_fatal_in>

These each are wrappers around Perl_ck_warner_d() to produce a deprecated
warning in the single category given by C<category>, with an appropriate
message.

They differ in the details of the message output, but all use as a base, the
C<message> argument, which must be a literal C string enclosed in
double-quotes.

In plain C<deprecate>, the string " is deprecated" will automatically be
added to the end of C<message>, yielding

 <message> is deprecated

The other two take a third argument C<when>, which is a literal C string in the
form like "5.40".  C<when> indicates in what release the axe is scheduled to
fall.

In C<<deprecate_disappears_in>, the actual message output will be of the form:

 <message> is deprecated, and will disappear in Perl <when>

In C<deprecate_fatal_in>, the message will be of the form:

 <message> is deprecated, and will become fatal in Perl <when>

=over 3

   deprecate              (U32 category, "message")
   deprecate_disappears_in(U32 category, "when", "message")
   deprecate_fatal_in     (U32 category, "when", "message")

=back

=back

=for hackers
deprecate declared at handy.h, line 3104; all in group documented at handy.h, line 3104
deprecate_disappears_in declared at handy.h, line 3105
deprecate_fatal_in declared at handy.h, line 3106

=over 4

=item C<find_uninit_var>
X<find_uninit_var>

NOTE: C<find_uninit_var> is B<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 C<uninit_sv>.
So roughly speaking, if a unary operator (such as C<OP_COS>) generates a
warning, then following the direct child of the op may yield an
C<OP_PADSV> or C<OP_GV> that gives the name of the undefined variable.  On the
other hand, with C<OP_ADD> there are two branches to follow, so we only print
the variable name if we get an exact match.
C<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 C<PL_op> is the OP that originally triggered the error, and that
C<PL_comppad>/C<PL_curpad> points to the currently executing pad.

=over 3

 SV *  find_uninit_var(const OP * const obase,
                       const SV * const uninit_sv, bool match,
                       const char **desc_p)

=back

=back

=for hackers
Declared at embed.fnc, line 6175; documented at sv.c, line 17736

=over 4

=item C<report_uninit>
X<report_uninit>

Print appropriate "Use of uninitialized variable" warning.

=over 3

 void       report_uninit(      const SV *uninit_sv)
 void  Perl_report_uninit(pTHX_ const SV *uninit_sv)

=back

=back

=for hackers
Declared at embed.fnc, line 3027; documented at sv.c, line 18534

=head1 XS


F<xsubpp> compiles XS code into C.  See L<perlutil/xsubpp>.

=for comment
Some variables below are flagged with 'u' because Devel::PPPort can't currently
readily test them as they spring into existence by compiling with xsubpp.


=over 4

=item C<api_version_assert>
X<api_version_assert>

Used by the PERL_API_VERSION_CHECK macro to compare the perl the
object was built with and the perl that C<libperl> was built with.

This can be used to ensure that these match and produces a more
diagnosable than random crashes and mis-behaviour.

=over 3

 void       api_version_assert(size_t interp_size,
                               void *v_my_perl,
                               const char *api_version)
 void  Perl_api_version_assert(size_t interp_size,
                               void *v_my_perl,
                               const char *api_version)

=back

=back

=for hackers
Declared at embed.fnc, line 869; documented at util.c, line 5741

=over 4

=item C<my_cxt_init>
X<my_cxt_init>

Implements the L<perlxs/C<MY_CXT_INIT>> macro, which you should use instead.

The first time a module is loaded, the global C<PL_my_cxt_index> is incremented,
and that value is assigned to that module's static C<my_cxt_index> (whose
address is passed as an arg).  Then, for each interpreter this function is
called for, it makes sure a C<void*> slot is available to hang the static data
off, by allocating or extending the interpreter's C<PL_my_cxt_list> array

=over 3

 void *  Perl_my_cxt_init(pTHX_ int *indexp, size_t size)

=back

=back

=for hackers
Declared at embed.fnc, line 4360; documented at util.c, line 5440

=over 4

=item C<my_cxt_t>

Described in L<perlxs>.

=back

=for hackers
Documented at dist/ExtUtils-ParseXS/lib/perlxs.pod, line 4799

=head1 Undocumented elements


This section lists the elements that are otherwise undocumented.  If you use
any of them, please consider creating and submitting documentation for it.

Experimental and deprecated undocumented elements are listed separately at the
end.


X<abort_execution>X<add_above_Latin1_folds>X<add_cp_to_invlist>
X<add_range_to_invlist_>X<allocmy>X<amagic_cmp>X<amagic_cmp_desc>
X<amagic_cmp_locale>X<amagic_cmp_locale_desc>X<amagic_i_ncmp>
X<amagic_i_ncmp_desc>X<amagic_is_enabled>X<amagic_ncmp>X<amagic_ncmp_desc>
X<any_dup>X<append_utf8_from_native_byte>X<apply>X<atfork_child>
X<atfork_lock>X<atfork_unlock>X<av_arylen_p>X<av_extend_guts>X<av_iter_p>
X<av_nonelem>X<av_reify>X<AvFILL_>X<bind_match>X<block_gimme>
X<boot_core_builtin>X<boot_core_mro>X<boot_core_PerlIO>
X<boot_core_UNIVERSAL>X<build_infix_plugin>X<byte_dump_string_>
X<call_list>X<cando>X<capture_clear>X<cast_iv>X<cast_i32>X<cast_ulong>
X<cast_uv>X<check_hash_fields_and_hekify>X<check_regnode_after>
X<check_utf8_print>X<ck_aassign>X<ck_anoncode>X<ck_anonhash>X<ck_backtick>
X<ck_bitop>X<ck_classname>X<ck_cmp>X<ck_concat>X<ck_defined>X<ck_delete>
X<ck_each>X<ck_entersub_args_core>X<ck_eof>X<ck_eval>X<ck_exec>
X<ck_exists>X<ck_ftst>X<ck_fun>X<ck_glob>X<ck_grep>X<ck_helemexistsor>
X<ck_index>X<ck_isa>X<ck_join>X<ck_length>X<ck_lfun>X<ck_listiob>
X<ck_match>X<ck_method>X<ck_null>X<ck_open>X<ck_prototype>X<ck_readline>
X<ck_refassign>X<ck_repeat>X<ck_require>X<ck_return>X<ck_rfun>
X<ck_rvconst>X<ck_sassign>X<ck_scmp>X<ck_select>X<ck_shift>
X<ck_smartmatch>X<ck_sort>X<ck_spair>X<ck_split>X<ck_stringify>X<ck_subr>
X<ck_substr>X<ck_svconst>X<ck_tell>X<ck_trunc>X<ck_trycatch>X<ckwarn>
X<ckwarn_d>X<class_add_ADJUST>X<class_add_field>X<class_apply_attributes>
X<class_apply_field_attributes>X<class_prepare_initfield_parse>
X<class_prepare_method_parse>X<class_seal_stash>X<class_set_field_defop>
X<class_setup_stash>X<class_wrap_method_body>X<clear_defarray>
X<closest_cop>X<cmp_desc>X<cmp_locale_desc>X<cmpchain_extend>
X<cmpchain_finish>X<cmpchain_start>X<cntrl_to_mnemonic>
X<construct_ahocorasick_from_trie>X<cop_file_avn>X<coresub_op>
X<croak_caller>X<croak_kw_unless_class>X<croak_memory_wrap>X<croak_no_mem>
X<croak_no_mem_ext>X<croak_popstack>X<csighandler>X<csighandler1>
X<csighandler3>X<current_re_engine>X<custom_op_get_field>X<cv_clone_into>
X<cv_const_sv_or_av>X<cv_undef_flags>X<cvgv_from_hek>X<cvgv_set>
X<cvstash_set>X<cx_dump>X<cx_dup>X<cxinc>X<deb_stack_all>X<debstackptrs>
X<debug_hash_seed>X<debug_peep>X<debug_show_study_flags>X<debug_studydata>
X<defelem_target>X<despatch_signals>X<die_unwind>X<do_aexec>X<do_aexec5>
X<do_aspawn>X<do_eof>X<do_exec>X<do_exec3>X<do_gv_dump>X<do_gvgv_dump>
X<do_hv_dump>X<do_ipcctl>X<do_ipcget>X<do_magic_dump>X<do_msgrcv>
X<do_msgsnd>X<do_ncmp>X<do_op_dump>X<do_pmop_dump>X<do_print>
X<do_readline>X<do_seek>X<do_semop>X<do_shmio>X<do_spawn>
X<do_spawn_nowait>X<do_sv_dump>X<do_sysseek>X<do_tell>X<do_trans>
X<do_uniprop_match>X<do_vecget>X<do_vecset>X<do_vop>X<does_utf8_overflow>
X<dofile>X<doing_taint>X<doref>X<drand48_init_r>X<drand48_r>
X<dtrace_probe_call>X<dtrace_probe_load>X<dtrace_probe_op>
X<dtrace_probe_phase>X<dump_all_perl>X<dump_indent>X<dump_packsubs_perl>
X<dump_sub_perl>X<dump_sv_child>X<dump_vindent>X<dumpuntil>X<dup_warnings>
X<find_first_differing_byte_pos>X<find_lexical_cv>X<find_runcv_where>
X<find_script>X<finish_export_lexical>X<foldEQ_latin1>
X<foldEQ_latin1_s2_folded>X<foldEQ_utf8_flags>X<force_locale_unlock>
X<force_out_malformed_utf8_message_>X<form_alien_digit_msg>
X<form_cp_too_large_msg>X<free_tied_hv_pool>X<free_tmps>
X<get_and_check_backslash_N_name>X<get_ANYOFHbbm_contents>
X<get_ANYOFM_contents>X<get_db_sub>X<get_debug_opts>
X<get_deprecated_property_msg>X<get_extended_os_errno>X<get_hash_seed>
X<get_invlist_iter_addr>X<get_invlist_offset_addr>
X<get_invlist_previous_index_addr>X<get_mstats>X<get_prop_definition>
X<get_prop_values>X<get_re_gclass_aux_data>X<get_regclass_aux_data>
X<get_regex_charset_name>X<get_win32_message_utf8ness>X<getenv_len>
X<gimme_V>X<gp_free>X<gp_ref>X<grok_bin_hex>X<grok_bslash_c>
X<grok_bslash_o>X<grok_bslash_x>X<gv_check>X<gv_fetchmeth_internal>
X<gv_override>X<gv_setref>X<gv_stashpvn_internal>X<he_dup>X<hek_dup>
X<hfree_next_entry>X<hv_auxalloc>X<hv_common>X<hv_common_key_len>
X<hv_delayfree_ent>X<hv_free_ent>X<hv_placeholders_p>X<hv_pushkv>
X<hv_rand_set>X<hv_undef_flags>X<import_builtin_bundle>
X<infix_plugin_standard>X<init_argv_symbols>X<init_constants>
X<init_dbargs>X<init_debugger>X<init_i18nl10n>X<init_named_cv>
X<init_stacks>X<init_tm>X<init_uniprops>X<inverse_folds_>X<invert>
X<invlist_array>X<invlist_array_init_>X<invlist_clear>X<invlist_clone>
X<invlist_contains_cp_>X<invlist_contents>X<invlist_dump_>
X<invlist_extend>X<invlist_highest>X<invlist_intersection_>
X<invlist_intersection_maybe_complement_2nd_>X<invlist_invert_>
X<invlist_is_iterating>X<invlist_iterfinish>X<invlist_iterinit>
X<invlist_iternext>X<invlist_len_>X<invlist_max>X<invlist_previous_index>
X<invlist_search_>X<invlist_set_len>X<invlist_set_previous_index>
X<invlist_subtract_>X<invlist_trim>X<invlist_union_>
X<invlist_union_maybe_complement_2nd_>X<invlistEQ_>X<invmap_dump>
X<invoke_exception_hook>X<io_close>X<is_grapheme>X<is_in_locale_category_>
X<is_invlist>X<is_standard_filehandle_name>X<is_uni_FOO_>
X<is_uni_perl_idcont_>X<is_uni_perl_idstart_>X<is_utf8_char_helper_>
X<is_utf8_FF_helper_>X<is_utf8_FOO_>X<is_utf8_overlong>
X<is_utf8_perl_idcont_>X<is_utf8_perl_idstart_>X<isFF_overlong>X<jmaybe>
X<join_exact>X<keyword>X<keyword_plugin_standard>X<list>X<load_charnames>
X<load_mathoms>X<locale_panic>X<localize>X<long_valid_utf8_to_uv>
X<lossless_NV_to_IV>X<lsbit_pos32>X<lsbit_pos64>X<magic_clear_all_env>
X<magic_cleararylen_p>X<magic_clearenv>X<magic_clearhook>
X<magic_clearhookall>X<magic_clearisa>X<magic_clearpack>X<magic_clearsig>
X<magic_copycallchecker>X<magic_existspack>X<magic_freearylen_p>
X<magic_freecollxfrm>X<magic_freemglob>X<magic_freeovrld>X<magic_freeutf8>
X<magic_get>X<magic_getarylen>X<magic_getdebugvar>X<magic_getdefelem>
X<magic_getnkeys>X<magic_getpack>X<magic_getpos>X<magic_getsig>
X<magic_getsubstr>X<magic_gettaint>X<magic_getuvar>X<magic_getvec>
X<magic_killbackrefs>X<magic_nextpack>X<magic_regdata_cnt>
X<magic_regdatum_get>X<magic_regdatum_set>X<magic_scalarpack>X<magic_set>
X<magic_set_all_env>X<magic_setarylen>X<magic_setcollxfrm>
X<magic_setdbline>X<magic_setdebugvar>X<magic_setdefelem>X<magic_setenv>
X<magic_sethook>X<magic_sethookall>X<magic_setisa>X<magic_setlvref>
X<magic_setmglob>X<magic_setnkeys>X<magic_setnonelem>X<magic_setpack>
X<magic_setpos>X<magic_setregexp>X<magic_setsig>X<magic_setsigall>
X<magic_setsubstr>X<magic_settaint>X<magic_setutf8>X<magic_setuvar>
X<magic_setvec>X<magic_sizepack>X<magic_wipepack>X<make_trie>
X<malloc_good_size>X<malloced_size>X<markstack_grow>X<mbtowc_>
X<mem_collxfrm_>X<mem_log_alloc>X<mem_log_del_sv>X<mem_log_free>
X<mem_log_new_sv>X<mem_log_realloc>X<mg_find_mglob>X<mg_free_struct>
X<mg_size>X<mode_from_discipline>X<more_bodies>X<more_sv>X<moreswitches>
X<mortal_getenv>X<mortalized_pv_copy>X<mro_get_private_data>
X<mro_meta_dup>X<mro_meta_init>X<msbit_pos32>X<msbit_pos64>
X<multiconcat_stringify>X<multideref_stringify>X<my_atof2>X<my_atof3>
X<my_attrs>X<my_clearenv>X<my_lstat>X<my_lstat_flags>X<my_memrchr>
X<my_mkostemp_cloexec>X<my_mkstemp_cloexec>X<my_stat>X<my_stat_flags>
X<my_strerror>X<my_unexec>X<new_invlist_>X<new_invlist_C_array_>
X<new_stackinfo>X<new_stackinfo_flags>X<new_sv>X<newMETHOP_internal>
X<newPROG>X<newSTUB>X<newSVavdefelem>X<newXS_deffile>X<nextargv>
X<no_bareword_allowed>X<no_bareword_filehandle>X<noperl_die>
X<notify_parser_that_encoding_changed>X<oopsAV>X<oopsHV>X<op_integerize>
X<op_prune_chain_head>X<op_relocate_sv>X<op_std_init>X<op_varname>
X<opmethod_stash>X<opslab_force_free>X<opslab_free>X<opslab_free_nopad>
X<opslab_slot_offset>X<output_non_portable>X<pad_add_weakref>
X<padlist_store>X<padname_free>X<PadnameIN_SCOPE>X<padnamelist_free>
X<parse_unicode_opts>X<parser_dup>X<parser_free>
X<parser_free_nexttoke_ops>X<path_is_searchable>X<peep>X<perl_alloc_using>
X<perl_clone_using>X<PerlEnv_putenv>X<PerlIO_context_layers>
X<PerlIO_restore_errno>X<PerlIO_save_errno>X<PerlLIO_dup_cloexec>
X<PerlLIO_dup2_cloexec>X<PerlLIO_open_cloexec>X<PerlLIO_open3_cloexec>
X<PerlProc_pipe_cloexec>X<PerlSock_accept_cloexec>
X<PerlSock_socket_cloexec>X<PerlSock_socketpair_cloexec>
X<perly_sighandler>X<pmruntime>X<POPMARK>
X<populate_anyof_bitmap_from_invlist>X<populate_bitmap_from_invlist>
X<populate_invlist_from_bitmap>X<populate_isa>X<pregfree>X<pregfree2>
X<prepare_export_lexical>X<re_exec_indentf>X<re_indentf>X<re_intuit_start>
X<re_intuit_string>X<re_op_compile>X<re_printf>X<ReANY>X<reentrant_free>
X<reentrant_init>X<reentrant_retry>X<reentrant_size>X<ref>X<reg_add_data>
X<reg_named_buff>X<reg_named_buff_all>X<reg_named_buff_exists>
X<reg_named_buff_fetch>X<reg_named_buff_firstkey>X<reg_named_buff_iter>
X<reg_named_buff_nextkey>X<reg_named_buff_scalar>
X<reg_numbered_buff_fetch>X<reg_numbered_buff_fetch_flags>
X<reg_numbered_buff_length>X<reg_numbered_buff_store>X<reg_qr_package>
X<reg_skipcomment>X<reg_temp_copy>X<regcurly>X<regdump>X<regdupe_internal>
X<regexec_flags>X<regfree_internal>X<reginitcolors>X<regnext>
X<regnode_after>X<regprop>X<release_RExC_state>X<report_evil_fh>
X<report_redefined_cv>X<report_wrongway_fh>X<resume_compcv>X<rpeep>
X<rsignal_restore>X<rsignal_save>X<rvpv_dup>X<rxres_save>X<same_dirent>
X<save_bool>X<save_clearsv>X<save_delete>X<save_destructor>
X<save_destructor_x>X<save_freeop>X<save_freepv>X<save_freesv>X<save_int>
X<save_iv>X<save_I8>X<save_I16>X<save_I32>X<save_mortalizesv>X<save_pptr>
X<save_pushi32ptr>X<save_pushptrptr>X<save_re_context>X<save_sptr>
X<save_strlen>X<savestack_grow>X<savestack_grow_cnt>X<sawparens>X<scalar>
X<scalarvoid>X<scan_commit>X<scan_num>X<seed>X<set_ANYOF_arg>
X<set_caret_X>X<set_numeric_standard>X<set_numeric_underlying>
X<set_padlist>X<setfd_cloexec>X<setfd_cloexec_for_nonsysfd>
X<setfd_cloexec_or_inhexec_by_sysfdness>X<setfd_inhexec>
X<setfd_inhexec_for_sysfd>X<setup_canned_invlist_>X<share_hek>
X<should_warn_nl>X<should_we_output_Debug_r>X<sighandler>X<sighandler1>
X<sighandler3>X<single_1bit_pos32>X<single_1bit_pos64>X<size_to_psize>
X<Slab_Alloc>X<Slab_Free>X<Slab_to_ro>X<Slab_to_rw>X<softref2xv>
X<sortsv_flags_impl>X<ssc_init>X<stack_grow>X<str_to_version>X<strxfrm>
X<study_chunk>X<sub_crush_depth>X<subsignature_append_fence_op>
X<subsignature_append_named>X<subsignature_append_positional>
X<subsignature_append_slurpy>X<subsignature_finish>X<subsignature_start>
X<sv_add_backref>X<sv_buf_to_ro>X<sv_can_swipe_pv_buf>X<sv_del_backref>
X<sv_i_ncmp>X<sv_i_ncmp_desc>X<sv_magicext_mglob>X<sv_mark_arenas>
X<sv_ncmp>X<sv_ncmp_desc>X<sv_only_taint_gmagic>X<sv_or_pv_pos_u2b>
X<sv_pvbyten_force_wrapper>X<sv_pvutf8n_force_wrapper>X<sv_resetpvn>
X<sv_sethek>X<sv_sweep_arenas>X<sv_unglob>X<sv_2iv>X<sv_2uv>X<SvPV_helper>
X<SvTRUE_common>X<switch_locale_context>X<sys_init>X<sys_init3>
X<sys_intern_clear>X<sys_intern_dup>X<sys_intern_init>X<sys_term>
X<tied_method>X<tmps_grow_p>X<to_fold_latin1_>X<to_uni_fold>
X<to_uni_fold_flags_>X<to_uni_lower>X<to_uni_title>X<to_uni_upper>
X<to_upper_title_latin1_>X<to_utf8_fold_flags_>X<to_utf8_lower_flags_>
X<to_utf8_title_flags_>X<to_utf8_upper_flags_>X<TOPMARK>
X<translate_substr_offsets>X<try_amagic_bin>X<try_amagic_un>X<unlnk>
X<unshare_hek>X<unwind_paren>X<utf8_to_bytes_>X<utf8_to_uv_msgs_helper_>
X<utf16_to_utf8>X<utf16_to_utf8_base>X<utf16_to_utf8_reversed>X<utilize>
X<uvoffuni_to_utf8_flags_msgs>X<variant_byte_number>X<varname>
X<vivify_defelem>X<vivify_ref>X<wait4pid>X<warn_elem_scalar_context>
X<warn_problematic_locale>X<was_lvalue_sub>X<watch>
X<win32_croak_not_implemented>X<write_to_stderr>X<xs_boot_epilog>
X<XS_builtin_indexed>X<xs_handshake>X<yyerror>X<yyerror_pv>X<yyerror_pvn>
X<yylex>X<yyparse>X<yyquit>X<yyunlex>

 abort_execution
 add_above_Latin1_folds
 add_cp_to_invlist
 add_range_to_invlist_
 allocmy
 amagic_cmp
 amagic_cmp_desc
 amagic_cmp_locale
 amagic_cmp_locale_desc
 amagic_i_ncmp
 amagic_i_ncmp_desc
 amagic_is_enabled
 amagic_ncmp
 amagic_ncmp_desc
 any_dup
 append_utf8_from_native_byte
 apply
 atfork_child
 atfork_lock
 atfork_unlock
 av_arylen_p
 av_extend_guts
 av_iter_p
 av_nonelem
 av_reify
 AvFILL_
 bind_match
 block_gimme
 boot_core_builtin
 boot_core_mro
 boot_core_PerlIO
 boot_core_UNIVERSAL
 build_infix_plugin
 byte_dump_string_
 call_list
 cando
 capture_clear
 cast_iv
 cast_i32
 cast_ulong
 cast_uv
 check_hash_fields_and_hekify
 check_regnode_after
 check_utf8_print
 ck_aassign
 ck_anoncode
 ck_anonhash
 ck_backtick
 ck_bitop
 ck_classname
 ck_cmp
 ck_concat
 ck_defined
 ck_delete
 ck_each
 ck_entersub_args_core
 ck_eof
 ck_eval
 ck_exec
 ck_exists
 ck_ftst
 ck_fun
 ck_glob
 ck_grep
 ck_helemexistsor
 ck_index
 ck_isa
 ck_join
 ck_length
 ck_lfun
 ck_listiob
 ck_match
 ck_method
 ck_null
 ck_open
 ck_prototype
 ck_readline
 ck_refassign
 ck_repeat
 ck_require
 ck_return
 ck_rfun
 ck_rvconst
 ck_sassign
 ck_scmp
 ck_select
 ck_shift
 ck_smartmatch
 ck_sort
 ck_spair
 ck_split
 ck_stringify
 ck_subr
 ck_substr
 ck_svconst
 ck_tell
 ck_trunc
 ck_trycatch
 ckwarn
 ckwarn_d
 class_add_ADJUST
 class_add_field
 class_apply_attributes
 class_apply_field_attributes
 class_prepare_initfield_parse
 class_prepare_method_parse
 class_seal_stash
 class_set_field_defop
 class_setup_stash
 class_wrap_method_body
 clear_defarray
 closest_cop
 cmp_desc
 cmp_locale_desc
 cmpchain_extend
 cmpchain_finish
 cmpchain_start
 cntrl_to_mnemonic
 construct_ahocorasick_from_trie
 cop_file_avn
 coresub_op
 croak_caller
 croak_kw_unless_class
 croak_memory_wrap
 croak_no_mem
 croak_no_mem_ext
 croak_popstack
 csighandler
 csighandler1
 csighandler3
 current_re_engine
 custom_op_get_field
 cv_clone_into
 cv_const_sv_or_av
 cv_undef_flags
 cvgv_from_hek
 cvgv_set
 cvstash_set
 cx_dump
 cx_dup
 cxinc
 deb_stack_all
 debstackptrs
 debug_hash_seed
 debug_peep
 debug_show_study_flags
 debug_studydata
 defelem_target
 despatch_signals
 die_unwind
 do_aexec
 do_aexec5
 do_aspawn
 do_eof
 do_exec
 do_exec3
 do_gv_dump
 do_gvgv_dump
 do_hv_dump
 do_ipcctl
 do_ipcget
 do_magic_dump
 do_msgrcv
 do_msgsnd
 do_ncmp
 do_op_dump
 do_pmop_dump
 do_print
 do_readline
 do_seek
 do_semop
 do_shmio
 do_spawn
 do_spawn_nowait
 do_sv_dump
 do_sysseek
 do_tell
 do_trans
 do_uniprop_match
 do_vecget
 do_vecset
 do_vop
 does_utf8_overflow
 dofile
 doing_taint
 doref
 drand48_init_r
 drand48_r
 dtrace_probe_call
 dtrace_probe_load
 dtrace_probe_op
 dtrace_probe_phase
 dump_all_perl
 dump_indent
 dump_packsubs_perl
 dump_sub_perl
 dump_sv_child
 dump_vindent
 dumpuntil
 dup_warnings
 find_first_differing_byte_pos
 find_lexical_cv
 find_runcv_where
 find_script
 finish_export_lexical
 foldEQ_latin1
 foldEQ_latin1_s2_folded
 foldEQ_utf8_flags
 force_locale_unlock
 force_out_malformed_utf8_message_
 form_alien_digit_msg
 form_cp_too_large_msg
 free_tied_hv_pool
 free_tmps
 get_and_check_backslash_N_name
 get_ANYOFHbbm_contents
 get_ANYOFM_contents
 get_db_sub
 get_debug_opts
 get_deprecated_property_msg
 get_extended_os_errno
 get_hash_seed
 get_invlist_iter_addr
 get_invlist_offset_addr
 get_invlist_previous_index_addr
 get_mstats
 get_prop_definition
 get_prop_values
 get_re_gclass_aux_data
 get_regclass_aux_data
 get_regex_charset_name
 get_win32_message_utf8ness
 getenv_len
 gimme_V
 gp_free
 gp_ref
 grok_bin_hex
 grok_bslash_c
 grok_bslash_o
 grok_bslash_x
 gv_check
 gv_fetchmeth_internal
 gv_override
 gv_setref
 gv_stashpvn_internal
 he_dup
 hek_dup
 hfree_next_entry
 hv_auxalloc
 hv_common
 hv_common_key_len
 hv_delayfree_ent
 hv_free_ent
 hv_placeholders_p
 hv_pushkv
 hv_rand_set
 hv_undef_flags
 import_builtin_bundle
 infix_plugin_standard
 init_argv_symbols
 init_constants
 init_dbargs
 init_debugger
 init_i18nl10n
 init_named_cv
 init_stacks
 init_tm
 init_uniprops
 inverse_folds_
 invert
 invlist_array
 invlist_array_init_
 invlist_clear
 invlist_clone
 invlist_contains_cp_
 invlist_contents
 invlist_dump_
 invlist_extend
 invlist_highest
 invlist_intersection_
 invlist_intersection_maybe_complement_2nd_
 invlist_invert_
 invlist_is_iterating
 invlist_iterfinish
 invlist_iterinit
 invlist_iternext
 invlist_len_
 invlist_max
 invlist_previous_index
 invlist_search_
 invlist_set_len
 invlist_set_previous_index
 invlist_subtract_
 invlist_trim
 invlist_union_
 invlist_union_maybe_complement_2nd_
 invlistEQ_
 invmap_dump
 invoke_exception_hook
 io_close
 is_grapheme
 is_in_locale_category_
 is_invlist
 is_standard_filehandle_name
 is_uni_FOO_
 is_uni_perl_idcont_
 is_uni_perl_idstart_
 is_utf8_char_helper_
 is_utf8_FF_helper_
 is_utf8_FOO_
 is_utf8_overlong
 is_utf8_perl_idcont_
 is_utf8_perl_idstart_
 isFF_overlong
 jmaybe
 join_exact
 keyword
 keyword_plugin_standard
 list
 load_charnames
 load_mathoms
 locale_panic
 localize
 long_valid_utf8_to_uv
 lossless_NV_to_IV
 lsbit_pos32
 lsbit_pos64
 magic_clear_all_env
 magic_cleararylen_p
 magic_clearenv
 magic_clearhook
 magic_clearhookall
 magic_clearisa
 magic_clearpack
 magic_clearsig
 magic_copycallchecker
 magic_existspack
 magic_freearylen_p
 magic_freecollxfrm
 magic_freemglob
 magic_freeovrld
 magic_freeutf8
 magic_get
 magic_getarylen
 magic_getdebugvar
 magic_getdefelem
 magic_getnkeys
 magic_getpack
 magic_getpos
 magic_getsig
 magic_getsubstr
 magic_gettaint
 magic_getuvar
 magic_getvec
 magic_killbackrefs
 magic_nextpack
 magic_regdata_cnt
 magic_regdatum_get
 magic_regdatum_set
 magic_scalarpack
 magic_set
 magic_set_all_env
 magic_setarylen
 magic_setcollxfrm
 magic_setdbline
 magic_setdebugvar
 magic_setdefelem
 magic_setenv
 magic_sethook
 magic_sethookall
 magic_setisa
 magic_setlvref
 magic_setmglob
 magic_setnkeys
 magic_setnonelem
 magic_setpack
 magic_setpos
 magic_setregexp
 magic_setsig
 magic_setsigall
 magic_setsubstr
 magic_settaint
 magic_setutf8
 magic_setuvar
 magic_setvec
 magic_sizepack
 magic_wipepack
 make_trie
 malloc_good_size
 malloced_size
 markstack_grow
 mbtowc_
 mem_collxfrm_
 mem_log_alloc
 mem_log_del_sv
 mem_log_free
 mem_log_new_sv
 mem_log_realloc
 mg_find_mglob
 mg_free_struct
 mg_size
 mode_from_discipline
 more_bodies
 more_sv
 moreswitches
 mortal_getenv
 mortalized_pv_copy
 mro_get_private_data
 mro_meta_dup
 mro_meta_init
 msbit_pos32
 msbit_pos64
 multiconcat_stringify
 multideref_stringify
 my_atof2
 my_atof3
 my_attrs
 my_clearenv
 my_lstat
 my_lstat_flags
 my_memrchr
 my_mkostemp_cloexec
 my_mkstemp_cloexec
 my_stat
 my_stat_flags
 my_strerror
 my_unexec
 new_invlist_
 new_invlist_C_array_
 new_stackinfo
 new_stackinfo_flags
 new_sv
 newMETHOP_internal
 newPROG
 newSTUB
 newSVavdefelem
 newXS_deffile
 nextargv
 no_bareword_allowed
 no_bareword_filehandle
 noperl_die
 notify_parser_that_encoding_changed
 oopsAV
 oopsHV
 op_integerize
 op_prune_chain_head
 op_relocate_sv
 op_std_init
 op_varname
 opmethod_stash
 opslab_force_free
 opslab_free
 opslab_free_nopad
 opslab_slot_offset
 output_non_portable
 pad_add_weakref
 padlist_store
 padname_free
 PadnameIN_SCOPE
 padnamelist_free
 parse_unicode_opts
 parser_dup
 parser_free
 parser_free_nexttoke_ops
 path_is_searchable
 peep
 perl_alloc_using
 perl_clone_using
 PerlEnv_putenv
 PerlIO_context_layers
 PerlIO_restore_errno
 PerlIO_save_errno
 PerlLIO_dup_cloexec
 PerlLIO_dup2_cloexec
 PerlLIO_open_cloexec
 PerlLIO_open3_cloexec
 PerlProc_pipe_cloexec
 PerlSock_accept_cloexec
 PerlSock_socket_cloexec
 PerlSock_socketpair_cloexec
 perly_sighandler
 pmruntime
 POPMARK
 populate_anyof_bitmap_from_invlist
 populate_bitmap_from_invlist
 populate_invlist_from_bitmap
 populate_isa
 pregfree
 pregfree2
 prepare_export_lexical
 re_exec_indentf
 re_indentf
 re_intuit_start
 re_intuit_string
 re_op_compile
 re_printf
 ReANY
 reentrant_free
 reentrant_init
 reentrant_retry
 reentrant_size
 ref
 reg_add_data
 reg_named_buff
 reg_named_buff_all
 reg_named_buff_exists
 reg_named_buff_fetch
 reg_named_buff_firstkey
 reg_named_buff_iter
 reg_named_buff_nextkey
 reg_named_buff_scalar
 reg_numbered_buff_fetch
 reg_numbered_buff_fetch_flags
 reg_numbered_buff_length
 reg_numbered_buff_store
 reg_qr_package
 reg_skipcomment
 reg_temp_copy
 regcurly
 regdump
 regdupe_internal
 regexec_flags
 regfree_internal
 reginitcolors
 regnext
 regnode_after
 regprop
 release_RExC_state
 report_evil_fh
 report_redefined_cv
 report_wrongway_fh
 resume_compcv
 rpeep
 rsignal_restore
 rsignal_save
 rvpv_dup
 rxres_save
 same_dirent
 save_bool
 save_clearsv
 save_delete
 save_destructor
 save_destructor_x
 save_freeop
 save_freepv
 save_freesv
 save_int
 save_iv
 save_I8
 save_I16
 save_I32
 save_mortalizesv
 save_pptr
 save_pushi32ptr
 save_pushptrptr
 save_re_context
 save_sptr
 save_strlen
 savestack_grow
 savestack_grow_cnt
 sawparens
 scalar
 scalarvoid
 scan_commit
 scan_num
 seed
 set_ANYOF_arg
 set_caret_X
 set_numeric_standard
 set_numeric_underlying
 set_padlist
 setfd_cloexec
 setfd_cloexec_for_nonsysfd
 setfd_cloexec_or_inhexec_by_sysfdness
 setfd_inhexec
 setfd_inhexec_for_sysfd
 setup_canned_invlist_
 share_hek
 should_warn_nl
 should_we_output_Debug_r
 sighandler
 sighandler1
 sighandler3
 single_1bit_pos32
 single_1bit_pos64
 size_to_psize
 Slab_Alloc
 Slab_Free
 Slab_to_ro
 Slab_to_rw
 softref2xv
 sortsv_flags_impl
 ssc_init
 stack_grow
 str_to_version
 strxfrm
 study_chunk
 sub_crush_depth
 subsignature_append_fence_op
 subsignature_append_named
 subsignature_append_positional
 subsignature_append_slurpy
 subsignature_finish
 subsignature_start
 sv_add_backref
 sv_buf_to_ro
 sv_can_swipe_pv_buf
 sv_del_backref
 sv_i_ncmp
 sv_i_ncmp_desc
 sv_magicext_mglob
 sv_mark_arenas
 sv_ncmp
 sv_ncmp_desc
 sv_only_taint_gmagic
 sv_or_pv_pos_u2b
 sv_pvbyten_force_wrapper
 sv_pvutf8n_force_wrapper
 sv_resetpvn
 sv_sethek
 sv_sweep_arenas
 sv_unglob
 sv_2iv
 sv_2uv
 SvPV_helper
 SvTRUE_common
 switch_locale_context
 sys_init
 sys_init3
 sys_intern_clear
 sys_intern_dup
 sys_intern_init
 sys_term
 tied_method
 tmps_grow_p
 to_fold_latin1_
 to_uni_fold
 to_uni_fold_flags_
 to_uni_lower
 to_uni_title
 to_uni_upper
 to_upper_title_latin1_
 to_utf8_fold_flags_
 to_utf8_lower_flags_
 to_utf8_title_flags_
 to_utf8_upper_flags_
 TOPMARK
 translate_substr_offsets
 try_amagic_bin
 try_amagic_un
 unlnk
 unshare_hek
 unwind_paren
 utf8_to_bytes_
 utf8_to_uv_msgs_helper_
 utf16_to_utf8
 utf16_to_utf8_base
 utf16_to_utf8_reversed
 utilize
 uvoffuni_to_utf8_flags_msgs
 variant_byte_number
 varname
 vivify_defelem
 vivify_ref
 wait4pid
 warn_elem_scalar_context
 warn_problematic_locale
 was_lvalue_sub
 watch
 win32_croak_not_implemented
 write_to_stderr
 xs_boot_epilog
 XS_builtin_indexed
 xs_handshake
 yyerror
 yyerror_pv
 yyerror_pvn
 yylex
 yyparse
 yyquit
 yyunlex

Next are the experimental undocumented elements


X<alloc_LOGOP>X<av_remove_offset>X<clear_defarray_simple>
X<create_eval_scope>X<cv_ckproto_len_flags>X<cx_popblock>X<cx_popeval>
X<cx_popformat>X<cx_popgiven>X<cx_poploop>X<cx_popsub>X<cx_popsub_args>
X<cx_popsub_common>X<cx_popwhen>X<cx_pushblock>X<cx_pusheval>
X<cx_pushformat>X<cx_pushgiven>X<cx_pushloop_for>X<cx_pushloop_plain>
X<cx_pushsub>X<cx_pushtry>X<cx_pushwhen>X<cx_topblock>X<delete_eval_scope>
X<do_open_raw>X<do_open6>X<emulate_cop_io>X<expected_size>X<get_re_arg>
X<get_vtbl>X<hv_backreferences_p>X<hv_kill_backrefs>
X<new_warnings_bitfield>X<newGP>X<op_refcnt_dec>X<op_refcnt_inc>
X<op_unscope>X<pop_stackinfo>X<pp_wrap>X<push_stackinfo>X<rpp_free_2_>
X<rpp_obliterate_stack_to>X<rpp_replace_2_1_COMMON>X<runops_wrap>
X<scan_str>X<scan_word>X<skipspace_flags>X<sv_free2>X<sv_kill_backrefs>
X<sv_setpv_freshbuf>X<sv_setsv_cow>X<switch_argstack>X<utf8_to_utf16_base>
X<xs_wrap>

 alloc_LOGOP            cx_pushloop_plain      pop_stackinfo
 av_remove_offset       cx_pushsub             pp_wrap
 clear_defarray_simple  cx_pushtry             push_stackinfo
 create_eval_scope      cx_pushwhen            rpp_free_2_
 cv_ckproto_len_flags   cx_topblock            rpp_obliterate_stack_to
 cx_popblock            delete_eval_scope      rpp_replace_2_1_COMMON
 cx_popeval             do_open_raw            runops_wrap
 cx_popformat           do_open6               scan_str
 cx_popgiven            emulate_cop_io         scan_word
 cx_poploop             expected_size          skipspace_flags
 cx_popsub              get_re_arg             sv_free2
 cx_popsub_args         get_vtbl               sv_kill_backrefs
 cx_popsub_common       hv_backreferences_p    sv_setpv_freshbuf
 cx_popwhen             hv_kill_backrefs       sv_setsv_cow
 cx_pushblock           new_warnings_bitfield  switch_argstack
 cx_pusheval            newGP                  utf8_to_utf16_base
 cx_pushformat          op_refcnt_dec          xs_wrap
 cx_pushgiven           op_refcnt_inc          
 cx_pushloop_for        op_unscope             

Finally are the deprecated undocumented elements.
Do not use any for new code; remove all occurrences of all of these from
existing code.


X<get_no_modify>X<get_opargs>X<get_ppaddr>X<uvuni_to_utf8>

 get_no_modify  get_opargs  get_ppaddr  uvuni_to_utf8  


=head1 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.

=head1 SEE ALSO

F<config.h>, L<perlapi>, L<perlapio>, L<perlcall>, L<perlclib>, L<perlembed>, L<perlfilter>, L<perlguts>, L<perlhacktips>, L<perlinterp>, L<perliol>, L<perlmroapi>, L<perlreapi>, L<perlreguts>, L<perlxs>

=cut

ex: set ro ft=pod:
