Provided by: perl-doc_5.40.0-8_all bug

NAME

       perlintern - autogenerated documentation of purely internal Perl functions

DESCRIPTION

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

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

AV Handling

       "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 "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 "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 "SV*".

           The rough perl equivalent is $myarray[$key].

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

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

            SSize_t  AvFILLp(AV* av)

       "av_new_alloc"
           This implements ""newAV_alloc_x"" in perlapi and ""newAV_alloc_xz"" in perlapi, 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 "0..(size-1)".  "size" must be at least 1.

           The "zeroflag" parameter controls whether or not the array is NULL initialized.

            AV *  av_new_alloc(SSize_t size, bool zeroflag)

       "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 "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 "key". It can be
           dereferenced to get the "SV*" that was stored there (= "val")).

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

           Approximate Perl equivalent: "splice(@myarray, $key, 1, $val)".

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

Callback Functions

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

           Implements the deprecated ""GIMME"" in perlapi.

            U8  dowantarray()

       "leave_scope"
           Implements "LEAVE_SCOPE" which you should use instead.

            void  leave_scope(I32 base)

       "magic_freedestruct"
           This function is called via magic to implement the mortal_destructor_sv() and
           mortal_destructor_x() functions. It should not be called directly and has no user
           servicable parts.

            int  magic_freedestruct(SV *sv, MAGIC *mg)

       "mortal_svfunc_x"
           This function arranges for a C function reference to be called at the end of the
           current statement with the arguments provided. It is a wrapper around
           mortal_destructor_sv() which ensures that the latter function is called appropriately.

           Be aware that there is a signficant difference in timing between the end of the
           current statement and the end of the current pseudo block. If you are looking for a
           mechanism to trigger a function at the end of the current pseudo block you should look
           at ""SAVEDESTRUCTOR_X"" in perlapi instead of this function.

            void  mortal_svfunc_x(SVFUNC_t f, SV *p)

       "pop_scope"
           Implements ""LEAVE"" in perlapi

            void  pop_scope()

       "push_scope"
           Implements ""ENTER"" in perlapi

            void  push_scope()

       "save_adelete"
           Implements "SAVEADELETE".

            void  save_adelete(AV *av, SSize_t key)

       "save_freercpv"
           Implements "SAVEFREERCPV".

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

            void  save_freercpv(char *rcpv)

       "save_generic_pvref"
           Implements "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.

            void  save_generic_pvref(char **str)

       "save_generic_svref"
           Implements "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.

            void  save_generic_svref(SV **sptr)

       "save_hdelete"
           Implements "SAVEHDELETE".

            void  save_hdelete(HV *hv, SV *keysv)

       "save_hints"
           Implements "SAVEHINTS".

            void  save_hints()

       "save_op"
           Implements "SAVEOP".

            void  save_op()

       "save_padsv_and_mortalize"
           Implements "SAVEPADSVANDMORTALIZE".

            void  save_padsv_and_mortalize(PADOFFSET off)

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

           This is the underlying implementation of several macros, like "SAVEFREESV".

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

       "save_rcpv"
           Implements "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.

            void  save_rcpv(char **prcpv)

       "save_scalar_at"
           A helper function for localizing the SV referenced by *sptr.

           If "SAVEf_KEEPOLDELEM" is set in in "flags", the function returns the input scalar
           untouched.

           Otherwise it replaces *sptr with a new "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 "SAVEf_SETMAGIC" is set in in "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 (e.g., 'local $x = $y'), and that will handle the magic.

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

       "save_set_svflags"
           Implements "SAVESETSVFLAGS".

           Set the SvFLAGS specified by mask to the values in val

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

       "save_shared_pvref"
           Implements "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.

            void  save_shared_pvref(char **str)

       "save_vptr"
           Implements "SAVEVPTR".

            void  save_vptr(void *ptr)

Casting

       There are currently no internal API items in Casting

Character case changing

       There are currently no internal API items in Character case changing

Character classification

       There are currently no internal API items in Character classification

Compiler and Preprocessor information

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

Compiler directives

       There are currently no internal API items in Compiler directives

Compile-time scope hooks

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

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

            void *  BhkENTRY(BHK *hk, token which)

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

           Return the BHK's flags.

            U32  BhkFLAGS(BHK *hk)

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

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

            void  CALL_BLOCK_HOOKS(token which, arg)

Concurrency

       "CVf_SLABBED"
       "CvROOT"
       "CvSTART"
           Described in perlguts.

       "CX_CUR"
           Described in perlguts.

              CX_CUR()

       "CXINC"
           Described in perlguts.

       "CX_LEAVE_SCOPE"
           Described in perlguts.

            void  CX_LEAVE_SCOPE(PERL_CONTEXT* cx)

       "CX_POP"
           Described in perlguts.

            void  CX_POP(PERL_CONTEXT* cx)

       "cxstack"
           Described in perlguts.

       "cxstack_ix"
           Described in perlguts.

       "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"
           Described in perlguts.

       "cx_type"
           Described in perlguts.

       "dounwind"
           Described in perlguts.

            void  dounwind(I32 cxix)

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

            Pid_t  my_fork()

       "PERL_CONTEXT"
           Described in perlguts.

COPs and Hint Hashes

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

Custom Operators

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

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

CV Handling

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

           Any CV that wraps an XSUB has an "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
           "any_sv" member of this union.  By setting this flag, this SV reference will be
           properly reclaimed or duplicated when the CV itself is.

            bool  CvREFCOUNTED_ANYSV(CV *cv)

       "CvREFCOUNTED_ANYSV_off"
           Helper macro to turn off the "CvREFCOUNTED_ANYSV" flag.

            void  CvREFCOUNTED_ANYSV_off(CV *cv)

       "CvREFCOUNTED_ANYSV_on"
           Helper macro to turn on the "CvREFCOUNTED_ANYSV" flag.

            void  CvREFCOUNTED_ANYSV_on(CV *cv)

       "CvWEAKOUTSIDE"
           Each CV has a pointer, CvOUTSIDE(), to its lexically enclosing CV (if any).  Because
           pointers to anonymous sub prototypes are stored in "&" pad slots, it is a possible to
           get a circular reference, with the parent pointing to the child and vice-versa.  To
           avoid the ensuing memory leak, we do not increment the reference count of the CV
           pointed to by "CvOUTSIDE" in the one specific instance that the parent has a "&" pad
           slot pointing back to us.  In this case, we set the "CvWEAKOUTSIDE" flag in the child.
           This allows us to determine under what circumstances we should decrement the refcount
           of the parent when freeing the child.

           There is a further complication with non-closure anonymous subs (i.e. those that do
           not refer to any lexicals outside that sub).  In this case, the anonymous prototype is
           shared rather than being cloned.  This has the consequence that the parent may be
           freed while there are still active children, e.g.,

               BEGIN { $a = sub { eval '$x' } }

           In this case, the BEGIN is freed immediately after execution since there are no active
           references to it: the anon sub prototype has "CvWEAKOUTSIDE" set since it's not a
           closure, and $a points to the same CV, so it doesn't contribute to BEGIN's refcount
           either.  When $a is executed, the "eval '$x'" causes the chain of "CvOUTSIDE"s to be
           followed, and the freed BEGIN is accessed.

           To avoid this, whenever a CV and its associated pad is freed, any "&" entries in the
           pad are explicitly removed from the pad, and if the refcount of the pointed-to anon
           sub is still positive, then that child's "CvOUTSIDE" is set to point to its
           grandparent.  This will only occur in the single specific case of a non-closure anon
           prototype having one or more active references (such as $a above).

           One other thing to consider is that a CV may be merely undefined rather than freed, eg
           "undef &foo".  In this case, its refcount may not have reached zero, but we still
           delete its pad and its "CvROOT" etc.  Since various children may still have their
           "CvOUTSIDE" pointing at this undefined CV, we keep its own "CvOUTSIDE" for the time
           being, so that the chain of lexical scopes is unbroken.  For example, the following
           should print 123:

               my $x = 123;
               sub tmp { sub { eval '$x' } }
               my $a = tmp();
               undef &tmp;
               print  $a->();

            bool  CvWEAKOUTSIDE(CV *cv)

       "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 "Exception handing" in perlinterp for further details.

            OP *  docatch(Perl_ppaddr_t firstpp)

Debugging

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

           The program is responsible for maintaining the correct value for "depth".

              comma_aDEPTH

       "comma_pDEPTH"
           This is used in the prototype declarations for functions that take a ""comma_aDEPTH""
           final parameter, much like "pTHX_" is used in functions that take a thread context
           initial parameter.

       "debop"
           Implements -Dt perl command line option on OP "o".

            I32  debop(const OP *o)

       "debprof"
           Called to indicate that "o" was executed, for profiling purposes under the "-DP"
           command line option.

            void  debprof(const OP *o)

       "debprofdump"
           Dumps the contents of the data collected by the "-DP" perl command line option.

            void  debprofdump()

       "debug_aDEPTH"
           Same as ""comma_aDEPTH"" but with no leading argument. Intended for functions with no
           normal arguments, and used by ""comma_aDEPTH"" itself.

              debug_aDEPTH

       "debug_pDEPTH"
           Same as ""comma_pDEPTH"" but with no leading argument. Intended for functions with no
           normal arguments, and used by ""comma_pDEPTH"" itself.

              debug_pDEPTH

       "free_c_backtrace"
           Deallocates a backtrace received from get_c_backtrace.

            void  free_c_backtrace(Perl_c_backtrace *bt)

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

           Scans the frames back by "depth + skip", then drops the "skip" innermost, returning at
           most "depth" frames.

            Perl_c_backtrace *  get_c_backtrace(int max_depth, int skip)

       "PL_DBsingle"
           When Perl is run in debugging mode, with the -d switch, this SV is a boolean which
           indicates whether subs are being single-stepped.  Single-stepping is automatically
           turned on after every step.  This is the C variable which corresponds to Perl's
           $DB::single variable.  See "PL_DBsub".

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

            SV *  PL_DBsingle

       "PL_DBsub"
           When Perl is run in debugging mode, with the -d switch, this GV contains the SV which
           holds the name of the sub being debugged.  This is the C variable which corresponds to
           Perl's $DB::sub variable.  See "PL_DBsingle".

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

            GV *  PL_DBsub

       "PL_DBtrace"
           Trace variable used when Perl is run in debugging mode, with the -d switch.  This is
           the C variable which corresponds to Perl's $DB::trace variable.  See "PL_DBsingle".

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

            SV *  PL_DBtrace

       "runops_debug"
           Described in perlguts.

            int  runops_debug()

       "runops_standard"
           Described in perlguts.

            int  runops_standard()

Display functions

       "sv_peek"
           Implements "SvPEEK"

            char *  sv_peek(SV *sv)

Embedding, Threads, and Interpreter Cloning

       "cv_dump"
           dump the contents of a CV

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

       "cv_forget_slab"
           When a CV has a reference count on its slab ("CvSLABBED"), it is responsible for
           making sure it is freed.  (Hence, no two CVs should ever have a reference count on the
           same slab.)  The CV only needs to reference the slab during compilation.  Once it is
           compiled and "CvROOT" attached, it has finished its job, so it can forget the slab.

            void  cv_forget_slab(CV *cv)

       "do_dump_pad"
           Dump the contents of a padlist

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

       "get_context"
           Implements ""PERL_GET_CONTEXT"" in perlapi, which you should use instead.

            void *  get_context()

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

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

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

            void  pad_block_start(int full)

       "pad_check_dup"
           Check for duplicate declarations: report any of:

                * a 'my' in the current scope with the same name;
                * an 'our' (anywhere in the pad) with the same name and the
                  same stash as 'ourstash'

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

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

       "pad_findlex"
           Find a named lexical anywhere in a chain of nested pads.  Add fake entries in the
           inner pads if it's found in an outer one.

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

           Note that pad_findlex() is recursive; it recurses up the chain of CVs, then comes back
           down, adding fake entries as it goes.  It has to be this way because fake names in
           anon prototypes have to store in "xpadn_low" the index into the parent pad.

            PADOFFSET  pad_findlex(const char *namepv, STRLEN namelen,
                                   U32 flags, const CV *cv, U32 seq, int warn,
                                   SV **out_capture, PADNAME **out_name,
                                   int *out_flags)

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

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

       "pad_free"
           Free the SV at offset po in the current pad.

            void  pad_free(PADOFFSET po)

       "pad_leavemy"
           Cleanup at end of scope during compilation: set the max seq number for lexicals in
           this scope and warn of any lexicals that never got introduced.

            OP *  pad_leavemy()

       "padlist_dup"
           Duplicates a pad.

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

       "padname_dup"
           Duplicates a pad name.

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

       "padnamelist_dup"
           Duplicates a pad name list.

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

       "pad_push"
           Push a new pad frame onto the padlist, unless there's already a pad at this depth, in
           which case don't bother creating a new one.  Then give the new pad an @_ in slot zero.

            void  pad_push(PADLIST *padlist, int depth)

       "pad_reset"
           Mark all the current temporaries for reuse

            void  pad_reset()

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

            void  pad_setsv(PADOFFSET po, SV *sv)

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

            SV *  pad_sv(PADOFFSET po)

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

            void  pad_swipe(PADOFFSET po, bool refadjust)

       "set_context"
           Implements ""PERL_SET_CONTEXT"" in perlapi, which you should use instead.

            void  set_context(void *t)

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

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

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

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

Errno

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

            void  dSAVEDERRNO

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

            void  dSAVE_ERRNO

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

            void  RESTORE_ERRNO

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

            void  SAVE_ERRNO

       "SETERRNO"
           Set "errno", and on VMS set "vaxc$errno".

            void  SETERRNO(int errcode, int vmserrcode)

Exception Handling (simple) Macros

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

Filesystem configuration values

       There are currently no internal API items in Filesystem configuration values

Floating point

       There are currently no internal API items in Floating point

General Configuration

       There are currently no internal API items in General Configuration

Global Variables

       There are currently no internal API items in Global Variables

GV Handling and Stashes

       "amagic_applies"
           Check "sv" to see if the overloaded (active magic) operation "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 succesfully
           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.

           "method" is an integer enum, one of the values found in overload.h, for instance
           "string_amg".

           "flags" should be set to AMG_unary for unary operations.

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

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

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

       "gv_handler"
           Implements "StashHANDLER", which you should use instead

            CV *  gv_handler(HV *stash, I32 id)

       "gv_stashsvpvn_cached"
           Returns a pointer to the stash for a specified package, possibly cached.  Implements
           both ""gv_stashpvn"" in perlapi and ""gv_stashsv"" in perlapi.

           Requires one of either "namesv" or "namepv" to be non-null.

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

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

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

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

           If the typeglob "gv" can be expressed more succinctly, by having something other than
           a real GV in its place in the stash, replace it with the optimised form.  Basic
           requirements for this are that "gv" is a real typeglob, is sufficiently ordinary, and
           is only referenced from its package.  This function is meant to be used when a GV has
           been looked up in part to see what was there, causing upgrading, but based on what was
           found it turns out that the real GV isn't required after all.

           If "gv" is a completely empty typeglob, it is deleted from the stash.

           If "gv" is a typeglob containing only a sufficiently-ordinary constant sub, the
           typeglob is replaced with a scalar-reference placeholder that more compactly
           represents the same thing.

            void  gv_try_downgrade(GV *gv)

Hook manipulation

       There are currently no internal API items in Hook manipulation

HV Handling

       "hv_eiter_p"
           Implements "HvEITER" which you should use instead.

           NOTE: "hv_eiter_p" must be explicitly called as "Perl_hv_eiter_p" with an "aTHX_"
           parameter.

            HE **  Perl_hv_eiter_p(pTHX_ HV *hv)

       "hv_eiter_set"
           Implements "HvEITER_set" which you should use instead.

           NOTE: "hv_eiter_set" must be explicitly called as "Perl_hv_eiter_set" with an "aTHX_"
           parameter.

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

       "hv_ename_add"
           Adds a name to a stash's internal list of effective names.  See "hv_ename_delete".

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

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

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

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

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

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

           This function implements the "HvFILL" macro 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.

           NOTE: "hv_fill" must be explicitly called as "Perl_hv_fill" with an "aTHX_" parameter.

            STRLEN  Perl_hv_fill(pTHX_ HV * const hv)

       "hv_placeholders_get"
           Implements "HvPLACEHOLDERS_get", which you should use instead.

           NOTE: "hv_placeholders_get" must be explicitly called as "Perl_hv_placeholders_get"
           with an "aTHX_" parameter.

            I32  Perl_hv_placeholders_get(pTHX_ const HV *hv)

       "hv_placeholders_set"
           Implements "HvPLACEHOLDERS_set", which you should use instead.

           NOTE: "hv_placeholders_set" must be explicitly called as "Perl_hv_placeholders_set"
           with an "aTHX_" parameter.

            void  Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)

       "hv_riter_p"
           Implements "HvRITER" which you should use instead.

           NOTE: "hv_riter_p" must be explicitly called as "Perl_hv_riter_p" with an "aTHX_"
           parameter.

            I32 *  Perl_hv_riter_p(pTHX_ HV *hv)

       "hv_riter_set"
           Implements "HvRITER_set" which you should use instead.

           NOTE: "hv_riter_set" must be explicitly called as "Perl_hv_riter_set" with an "aTHX_"
           parameter.

            void  Perl_hv_riter_set(pTHX_ HV *hv, I32 riter)

       "refcounted_he_chain_2hv"
           Generates and returns a "HV *" representing the content of a "refcounted_he" chain.
           "flags" is currently unused and must be zero.

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

       "refcounted_he_fetch_pv"
           Like "refcounted_he_fetch_pvn", but takes a nul-terminated string instead of a
           string/length pair.

            SV *  refcounted_he_fetch_pv(const struct refcounted_he *chain,
                                         const char *key, U32 hash, U32 flags)

       "refcounted_he_fetch_pvn"
           Search along a "refcounted_he" chain for an entry with the key specified by "keypv"
           and "keylen".  If "flags" has the "REFCOUNTED_HE_KEY_UTF8" bit set, the key octets are
           interpreted as UTF-8, otherwise they are interpreted as Latin-1.  "hash" is a
           precomputed hash of the key string, or zero if it has not been precomputed.  Returns a
           mortal scalar representing the value associated with the key, or &PL_sv_placeholder if
           there is no value associated with the key.

            SV *  refcounted_he_fetch_pvn(const struct refcounted_he *chain,
                                          const char *keypv, STRLEN keylen,
                                          U32 hash, U32 flags)

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

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

       "refcounted_he_fetch_sv"
           Like "refcounted_he_fetch_pvn", but takes a Perl scalar instead of a string/length
           pair.

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

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

            void  refcounted_he_free(struct refcounted_he *he)

       "refcounted_he_inc"
           Increment the reference count of a "refcounted_he".  The pointer to the
           "refcounted_he" is also returned.  It is safe to pass a null pointer to this function:
           no action occurs and a null pointer is returned.

            struct refcounted_he *  refcounted_he_inc(
                                                     struct refcounted_he *he)

       "refcounted_he_new_pv"
           Like "refcounted_he_new_pvn", but takes a nul-terminated string instead of a
           string/length pair.

            struct refcounted_he *  refcounted_he_new_pv(
                                                 struct refcounted_he *parent,
                                                 const char *key, U32 hash,
                                                 SV *value, U32 flags)

       "refcounted_he_new_pvn"
           Creates a new "refcounted_he".  This consists of a single key/value pair and a
           reference to an existing "refcounted_he" chain (which may be empty), and thus forms a
           longer chain.  When using the longer chain, the new key/value pair takes precedence
           over any entry for the same key further along the chain.

           The new key is specified by "keypv" and "keylen".  If "flags" has the
           "REFCOUNTED_HE_KEY_UTF8" bit set, the key octets are interpreted as UTF-8, otherwise
           they are interpreted as Latin-1.  "hash" is a precomputed hash of the key string, or
           zero if it has not been precomputed.

           "value" is the scalar value to store for this key.  "value" is copied by this
           function, which thus does not take ownership of any reference to it, and later changes
           to the scalar will not be reflected in the value visible in the "refcounted_he".
           Complex types of scalar will not be stored with referential integrity, but will be
           coerced to strings.  "value" may be either null or &PL_sv_placeholder to indicate that
           no value is to be associated with the key; this, as with any non-null value, takes
           precedence over the existence of a value for the key further along the chain.

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

            struct refcounted_he *  refcounted_he_new_pvn(
                                                 struct refcounted_he *parent,
                                                 const char *keypv,
                                                 STRLEN keylen, U32 hash,
                                                 SV *value, U32 flags)

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

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

       "refcounted_he_new_sv"
           Like "refcounted_he_new_pvn", but takes a Perl scalar instead of a string/length pair.

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

       "unsharepvn"
           If no one has access to shared string "str" with length "len", free it.

           "len" and "hash" must both be valid for "str".

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

Input/Output

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

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

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

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

       "my_fflush_all"
           Implements "PERL_FLUSHALL_FOR_CHILD" on some platforms.

            I32  my_fflush_all()

       "my_mkostemp"
           The C library mkostemp(3) if available, or a Perl implementation of it.

           NOTE: "my_mkostemp" must be explicitly called as "Perl_my_mkostemp" .

            int  Perl_my_mkostemp(char *templte, int flags)

       "my_mkstemp"
           The C library mkstemp(3) if available, or a Perl implementation of it.

           NOTE: "my_mkstemp" must be explicitly called as "Perl_my_mkstemp" .

            int  Perl_my_mkstemp(char *templte)

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

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

            GV*  PL_last_in_gv

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

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

            GV*  PL_ofsgv

       "PL_rs"
           The input record separator - $/ in Perl space.

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

            SV*  PL_rs

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

           Function called by "do_readline" to spawn a glob (or do the glob inside perl on VMS).
           This code used to be inline, but now perl uses "File::Glob" this glob starter is only
           used by miniperl during the build process, or when PERL_EXTERNAL_GLOB is defined.
           Moving it away shrinks pp_hot.c; shrinking pp_hot.c helps speed perl up.

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

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

Integer

       There are currently no internal API items in Integer

I/O Formats

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

Lexer interface

       "resume_compcv_and_save"
           Resumes a buffer previously suspended by the "suspend_compcv" function, in a way that
           will be re-suspended at the end of the scope so it can be used again later.  This
           should be used within an "ENTER"/"LEAVE" scoped pair.

            void  resume_compcv_and_save(struct suspended_compcv *buffer)

       "resume_compcv_final"
           Resumes the parser state previously saved using the "suspend_compcv" function for a
           final time before being compiled into a full CV.  This should be used within an
           "ENTER"/"LEAVE" scoped pair.

            void  resume_compcv_final(struct suspended_compcv *buffer)

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

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

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

           Note that "NULL" is a valid "proto" and will always return "true".

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

Locales

       There are currently no internal API items in Locales

Magic

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

            int  magic_clearhint(SV *sv, MAGIC *mg)

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

            int  magic_clearhints(SV *sv, MAGIC *mg)

       "magic_methcall"
           Invoke a magic method (like FETCH).

           "sv" and "mg" are the tied thingy and the tie magic.

           "meth" is the name of the method to call.

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

           The "flags" can be:

               G_DISCARD     invoke method with G_DISCARD flag and don't
                             return a value
               G_UNDEF_FILL  fill the stack with argc pointers to
                             PL_sv_undef

           The arguments themselves are any values following the "flags" argument.

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

           NOTE: "magic_methcall" must be explicitly called as "Perl_magic_methcall" with an
           "aTHX_" parameter.

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

       "magic_sethint"
           Triggered by a store to "%^H", records the key/value pair to
           "PL_compiling.cop_hints_hash".  It is assumed that hints aren't storing anything that
           would need a deep copy.  Maybe we should warn if we find a reference.

            int  magic_sethint(SV *sv, MAGIC *mg)

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

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

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

           If "setmagic" is false then no set magic will be called on the new (empty) SV.  This
           typically means that assignment will soon follow (e.g. 'local $x = $y'), and that will
           handle the magic.

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

Memory Management

       "calloc"
           Implements ""Newxz"" in perlapi which you should use instead.

           NOTE: "calloc" must be explicitly called as "Perl_calloc" .

            Malloc_t  Perl_calloc(MEM_SIZE elements, MEM_SIZE size)

       "malloc"
           Implements ""Newx"" in perlapi which you should use instead.

           NOTE: "malloc" must be explicitly called as "Perl_malloc" .

            Malloc_t  Perl_malloc(MEM_SIZE nbytes)

       "mfree"
           Implements ""Safefree"" in perlapi which you should use instead.

           NOTE: "mfree" must be explicitly called as "Perl_mfree" .

            Free_t  Perl_mfree(Malloc_t where)

       "realloc"
           Implements ""Renew"" in perlapi which you should use instead.

           NOTE: "realloc" must be explicitly called as "Perl_realloc" .

            Malloc_t  Perl_realloc(Malloc_t where, MEM_SIZE nbytes)

MRO

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

           You are responsible for SvREFCNT_inc() on the return value if you plan to store it
           anywhere semi-permanently (otherwise it might be deleted out from under you the next
           time the cache is invalidated).

            AV *  mro_get_linear_isa_dfs(HV *stash, U32 level)

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

            void  mro_isa_changed_in(HV *stash)

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

           This can also be called with a null first argument to indicate that "oldstash" has
           been deleted.

           This function invalidates isa caches on the old stash, on all subpackages nested
           inside it, and on the subclasses of all those, including non-existent packages that
           have corresponding entries in "stash".

           It also sets the effective names ("HvENAME") on all the stashes as appropriate.

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

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

Multicall Functions

       There are currently no internal API items in Multicall Functions

Numeric Functions

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

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

            bool  isinfnansv(SV *sv)

Optrees

       "newATTRSUB_x"
           Construct a Perl subroutine, also performing some surrounding jobs.

           This function is expected to be called in a Perl compilation context, and some aspects
           of the subroutine are taken from global variables associated with compilation.  In
           particular, "PL_compcv" represents the subroutine that is currently being compiled.
           It must be non-null when this function is called, and some aspects of the subroutine
           being constructed are taken from it.  The constructed subroutine may actually be a
           reuse of the "PL_compcv" object, but will not necessarily be so.

           If "block" is null then the subroutine will have no body, and for the time being it
           will be an error to call it.  This represents a forward subroutine declaration such as
           "sub foo ($$);".  If "block" is non-null then it provides the Perl code of the
           subroutine body, which will be executed when the subroutine is called.  This body
           includes any argument unwrapping code resulting from a subroutine signature or
           similar.  The pad use of the code must correspond to the pad attached to "PL_compcv".
           The code is not expected to include a "leavesub" or "leavesublv" op; this function
           will add such an op.  "block" is consumed by this function and will become part of the
           constructed subroutine.

           "proto" specifies the subroutine's prototype, unless one is supplied as an attribute
           (see below).  If "proto" is null, then the subroutine will not have a prototype.  If
           "proto" is non-null, it must point to a "const" op whose value is a string, and the
           subroutine will have that string as its prototype.  If a prototype is supplied as an
           attribute, the attribute takes precedence over "proto", but in that case "proto"
           should preferably be null.  In any case, "proto" is consumed by this function.

           "attrs" supplies attributes to be applied the subroutine.  A handful of attributes
           take effect by built-in means, being applied to "PL_compcv" immediately when seen.
           Other attributes are collected up and attached to the subroutine by this route.
           "attrs" may be null to supply no attributes, or point to a "const" op for a single
           attribute, or point to a "list" op whose children apart from the "pushmark" are
           "const" ops for one or more attributes.  Each "const" op must be a string, giving the
           attribute name optionally followed by parenthesised arguments, in the manner in which
           attributes appear in Perl source.  The attributes will be applied to the sub by this
           function.  "attrs" is consumed by this function.

           If "o_is_gv" is false and "o" is null, then the subroutine will be anonymous.  If
           "o_is_gv" is false and "o" is non-null, then "o" must point to a "const" OP, which
           will be consumed by this function, and its string value supplies a name for the
           subroutine.  The name may be qualified or unqualified, and if it is unqualified then a
           default stash will be selected in some manner.  If "o_is_gv" is true, then "o" doesn't
           point to an "OP" at all, but is instead a cast pointer to a "GV" by which the
           subroutine will be named.

           If there is already a subroutine of the specified name, then the new sub will either
           replace the existing one in the glob or be merged with the existing one.  A warning
           may be generated about redefinition.

           If the subroutine has one of a few special names, such as "BEGIN" or "END", then it
           will be claimed by the appropriate queue for automatic running of phase-related
           subroutines.  In this case the relevant glob will be left not containing any
           subroutine, even if it did contain one before.  In the case of "BEGIN", the subroutine
           will be executed and the reference to it disposed of before this function returns.

           The function returns a pointer to the constructed subroutine.  If the sub is anonymous
           then ownership of one counted reference to the subroutine is transferred to the
           caller.  If the sub is named then the caller does not get ownership of a reference.
           In most such cases, where the sub has a non-phase name, the sub will be alive at the
           point it is returned by virtue of being contained in the glob that names it.  A phase-
           named subroutine will usually be alive by virtue of the reference owned by the phase's
           automatic run queue.  But a "BEGIN" subroutine, having already been executed, will
           quite likely have been destroyed already by the time this function returns, making it
           erroneous for the caller to make any use of the returned pointer.  It is the caller's
           responsibility to ensure that it knows which of these situations applies.

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

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

           Similar in action to ""newATTRSUB_x"" in perlintern.

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

       "newXS_len_flags"
           Construct an XS subroutine, also performing some surrounding jobs.

           The subroutine will have the entry point "subaddr".  It will have the prototype
           specified by the nul-terminated string "proto", or no prototype if "proto" is null.
           The prototype string is copied; the caller can mutate the supplied string afterwards.
           If "filename" is non-null, it must be a nul-terminated filename, and the subroutine
           will have its "CvFILE" set accordingly.  By default "CvFILE" is set to point directly
           to the supplied string, which must be static.  If "flags" has the
           "XS_DYNAMIC_FILENAME" bit set, then a copy of the string will be taken instead.

           Other aspects of the subroutine will be left in their default state.  If anything else
           needs to be done to the subroutine for it to function correctly, it is the caller's
           responsibility to do that after this function has constructed it.  However, beware of
           the subroutine potentially being destroyed before this function returns, as described
           below.

           If "name" is null then the subroutine will be anonymous, with its "CvGV" referring to
           an "__ANON__" glob.  If "name" is non-null then the subroutine will be named
           accordingly, referenced by the appropriate glob.  "name" is a string of length "len"
           bytes giving a sigilless symbol name, in UTF-8 if "flags" has the "SVf_UTF8" bit set
           and in Latin-1 otherwise.  The name may be either qualified or unqualified, with the
           stash defaulting in the same manner as for "gv_fetchpvn_flags".  "flags" may contain
           flag bits understood by "gv_fetchpvn_flags" with the same meaning as they have there,
           such as "GV_ADDWARN".  The symbol is always added to the stash if necessary, with
           "GV_ADDMULTI" semantics.

           If there is already a subroutine of the specified name, then the new sub will replace
           the existing one in the glob.  A warning may be generated about the redefinition.  If
           the old subroutine was "CvCONST" then the decision about whether to warn is influenced
           by an expectation about whether the new subroutine will become a constant of similar
           value.  That expectation is determined by "const_svp".  (Note that the call to this
           function doesn't make the new subroutine "CvCONST" in any case; that is left to the
           caller.)  If "const_svp" is null then it indicates that the new subroutine will not
           become a constant.  If "const_svp" is non-null then it indicates that the new
           subroutine will become a constant, and it points to an "SV*" that provides the
           constant value that the subroutine will have.

           If the subroutine has one of a few special names, such as "BEGIN" or "END", then it
           will be claimed by the appropriate queue for automatic running of phase-related
           subroutines.  In this case the relevant glob will be left not containing any
           subroutine, even if it did contain one before.  In the case of "BEGIN", the subroutine
           will be executed and the reference to it disposed of before this function returns, and
           also before its prototype is set.  If a "BEGIN" subroutine would not be sufficiently
           constructed by this function to be ready for execution then the caller must prevent
           this happening by giving the subroutine a different name.

           The function returns a pointer to the constructed subroutine.  If the sub is anonymous
           then ownership of one counted reference to the subroutine is transferred to the
           caller.  If the sub is named then the caller does not get ownership of a reference.
           In most such cases, where the sub has a non-phase name, the sub will be alive at the
           point it is returned by virtue of being contained in the glob that names it.  A phase-
           named subroutine will usually be alive by virtue of the reference owned by the phase's
           automatic run queue.  But a "BEGIN" subroutine, having already been executed, will
           quite likely have been destroyed already by the time this function returns, making it
           erroneous for the caller to make any use of the returned pointer.  It is the caller's
           responsibility to ensure that it knows which of these situations applies.

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

       "op_refcnt_lock"
           Implements the "OP_REFCNT_LOCK" macro which you should use instead.

            void  op_refcnt_lock()

       "op_refcnt_unlock"
           Implements the "OP_REFCNT_UNLOCK" macro which you should use instead.

            void  op_refcnt_unlock()

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

           The initial call must supply the root of the tree as both top and o.

           For now it's static, but it may be exposed to the API in the future.

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

Pack and Unpack

       There are currently no internal API items in Pack and Unpack

Pad Data Structures

       "CX_CURPAD_SAVE"
           Save the current pad in the given context block structure.

            void  CX_CURPAD_SAVE(struct context)

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

            SV *  CX_CURPAD_SV(struct context, PADOFFSET po)

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

            SV *  PAD_BASE_SV(PADLIST padlist, PADOFFSET po)

       "PAD_CLONE_VARS"
           Clone the state variables associated with running and compiling pads.

            void  PAD_CLONE_VARS(PerlInterpreter *proto_perl,
                                 CLONE_PARAMS* param)

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

            U32  PAD_COMPNAME_FLAGS(PADOFFSET po)

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

            STRLEN  PAD_COMPNAME_GEN(PADOFFSET po)

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

            STRLEN  PAD_COMPNAME_GEN_set(PADOFFSET po, int gen)

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

            HV *  PAD_COMPNAME_OURSTASH(PADOFFSET po)

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

            char *  PAD_COMPNAME_PV(PADOFFSET po)

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

            HV *  PAD_COMPNAME_TYPE(PADOFFSET po)

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

            bool  PadnameIsFIELD(PADNAME * pn)

       "PadnameIsOUR"
           Whether this is an "our" variable.

            bool  PadnameIsOUR(PADNAME * pn)

       "PadnameIsSTATE"
           Whether this is a "state" variable.

            bool  PadnameIsSTATE(PADNAME * pn)

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

            HV *  PadnameOURSTASH(PADNAME * pn)

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

            bool  PadnameOUTER(PADNAME * pn)

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

            HV *  PadnameTYPE(PADNAME * pn)

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

            void  PAD_RESTORE_LOCAL(PAD *opad)

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

            void  PAD_SAVE_LOCAL(PAD *opad, PAD *npad)

       "PAD_SAVE_SETNULLPAD"
           Save the current pad then set it to null.

            void  PAD_SAVE_SETNULLPAD()

       "PAD_SET_CUR"
           Set the current pad to be pad "n" in the padlist, saving the previous current pad.  NB
           currently this macro expands to a string too long for some compilers, so it's best to
           replace it with

               SAVECOMPPAD();
               PAD_SET_CUR_NOSAVE(padlist,n);

            void  PAD_SET_CUR(PADLIST padlist, I32 n)

       "PAD_SET_CUR_NOSAVE"
           like PAD_SET_CUR, but without the save

            void  PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)

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

            SV *  PAD_SETSV(PADOFFSET po, SV* sv)

       "PAD_SV"
           Get the value at offset "po" in the current pad

            SV *  PAD_SV(PADOFFSET po)

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

            SV *  PAD_SVl(PADOFFSET po)

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

            void  SAVECLEARSV(SV **svp)

       "SAVECOMPPAD"
           save "PL_comppad" and "PL_curpad"

            void  SAVECOMPPAD()

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

            void  SAVEPADSV(PADOFFSET po)

Password and Group access

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

Paths to system commands

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

Prototype information

       There are currently no internal API items in Prototype information

Reference-counted stack manipulation

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

REGEXP Functions

       "regnode"
           Described in perlreguts.

Reports and Formats

       There are currently no internal API items in Reports and Formats

Signals

       There are currently no internal API items in Signals

Site configuration

       There are currently no internal API items in Site configuration

Sockets configuration values

       There are currently no internal API items in Sockets configuration values

Source Filters

       There are currently no internal API items in Source Filters

Stack Manipulation Macros

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

              djSP();

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

       "save_alloc"
           Implements ""SSNEW"" in perlapi and kin, which should be used instead of this
           function.

            SSize_t  save_alloc(SSize_t size, I32 pad)

String Handling

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

           The number of bytes copied is written to *retlen.

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

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

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

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

       "my_cxt_init"
           Implements the ""MY_CXT_INIT"" in perlxs macro, which you should use instead.

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

           NOTE: "my_cxt_init" must be explicitly called as "Perl_my_cxt_init" with an "aTHX_"
           parameter.

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

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

           The format specifier detection is not complete printf-syntax detection, but it should
           catch most common cases.

           If true is returned, those arguments should in theory be processed with
           quadmath_snprintf(), but in case there is more than one such format specifier (see
           "quadmath_format_valid"), and if there is anything else beyond that one (even just a
           single byte), they cannot be processed because quadmath_snprintf() is very strict,
           accepting only one format spec, and nothing else.  In this case, the code should
           probably fail.

            bool  quadmath_format_needed(const char *format)

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

           quadmath_format_valid() checks that the intended single spec looks sane: begins with
           "%", has only one "%", ends with "[efgaEFGA]", and has "Q" before it.  This is not a
           full "printf syntax check", just the basics.

           Returns true if it is valid, false if not.

           See also "quadmath_format_needed".

            bool  quadmath_format_valid(const char *format)

SV Flags

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

SV Handling

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

           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.

              PL_Sv

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

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

       "sv_2bool"
           This macro is only used by sv_true() or its macro equivalent, and only if the latter's
           argument is neither "SvPOK", "SvIOK" nor "SvNOK".  It calls "sv_2bool_flags" with the
           "SV_GMAGIC" flag.

            bool  sv_2bool(SV * const sv)

       "sv_2bool_flags"
           This function is only used by sv_true() and friends,  and only if the latter's
           argument is neither "SvPOK", "SvIOK" nor "SvNOK".  If the flags contain "SV_GMAGIC",
           then it does an mg_get() first.

            bool  sv_2bool_flags(SV *sv, I32 flags)

       "sv_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.

            SSize_t  sv_clean_all()

       "sv_clean_objs"
           Attempt to destroy all objects not yet freed.

            void  sv_clean_objs()

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

            void  sv_free_arenas()

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

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

       "sv_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.

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

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

            SV *  sv_newref(SV * const sv)

       "sv_2num"
           NOTE: "sv_2num" is experimental and may change or be removed without notice.

           Return an SV with the numeric value of the source SV, doing any necessary reference or
           overload conversion.  The caller is expected to have handled get-magic already.

            SV *  sv_2num(SV * const sv)

       "sv_pv"
           Use the "SvPV_nolen" macro instead

            char *  sv_pv(SV *sv)

       "sv_pvbyte"
           Use "SvPVbyte_nolen" instead.

            char *  sv_pvbyte(SV *sv)

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

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

       "sv_2pvbyte_nolen"
           Return a pointer to the byte-encoded representation of the SV.  May cause the SV to be
           downgraded from UTF-8 as a side-effect.

           Usually accessed via the "SvPVbyte_nolen" macro.

            char *  sv_2pvbyte_nolen(SV *sv)

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

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

       "sv_2pv_nolen"
           Like sv_2pv(), but doesn't return the length too.  You should usually use the macro
           wrapper SvPV_nolen(sv) instead.

            char *  sv_2pv_nolen(SV *sv)

       "sv_pvutf8n_force"
           The backend for the "SvPVutf8x_force" macro.  Always use the macro instead.

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

       "sv_2pvutf8_nolen"
           Return a pointer to the UTF-8-encoded representation of the SV.  May cause the SV to
           be upgraded to UTF-8 as a side-effect.

           Usually accessed via the "SvPVutf8_nolen" macro.

            char *  sv_2pvutf8_nolen(SV *sv)

       "sv_pvutf8"
           Use the "SvPVutf8_nolen" macro instead

            char *  sv_pvutf8(SV *sv)

       "sv_tainted"
           Test an SV for taintedness.  Use "SvTAINTED" instead.

            bool  sv_tainted(SV * const sv)

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

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

           This is used internally by various sv-modifying functions, such as "sv_setsv",
           "sv_setiv" and "sv_pvn_force".

           One case that this does not handle is a gv without SvFAKE set.  After

               if (SvTHINKFIRST(gv)) sv_force_normal(gv);

           it will still be a gv.

           "SvTHINKFIRST" sometimes produces false positives.  In those cases "sv_force_normal"
           does nothing.

            U32  SvTHINKFIRST(SV *sv)

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

            I32  sv_true(SV * const sv)

       "sv_untaint"
           Untaint an SV.  Use "SvTAINTED_off" instead.

            void  sv_untaint(SV * const sv)

Tainting

       "sv_taint"
           Taint an SV.  Use "SvTAINTED_on" instead.

            void  sv_taint(SV *sv)

       "TAINT"
           If we aren't in taint checking mode, do nothing; otherwise indicate to ""TAINT_set""
           and ""TAINT_PROPER"" that some unspecified element is tainted.

            void  TAINT()

       "TAINT_ENV"
           Looks at several components of %ENV for taintedness, and calls ""taint_proper"" if any
           are tainted.  The components it searches are things like $PATH.

            void  TAINT_ENV

       "taint_env"
           Implements the "TAINT_ENV" macro, which you should generally use instead.

            void  taint_env()

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

            bool  TAINT_get()

       "TAINT_IF"
           If "c" evaluates to true, call ""TAINT"" to indicate that something is tainted;
           otherwise do nothing.

            void  TAINT_IF(bool c)

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

            bool  TAINTING_get()

       "TAINTING_set"
           Turn taint checking mode off/on

            void  TAINTING_set(bool s)

       "TAINT_NOT"
           Remove any taintedness previously set by, e.g., "TAINT".

            void  TAINT_NOT()

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

            void  TAINT_PROPER(const char * s)

       "taint_proper"
           Implements the "TAINT_PROPER" macro, which you should generally use instead.

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

       "TAINT_set"
           If "s" is true, ""TAINT_get"" returns true; If "s" is false, ""TAINT_get"" returns
           false;

            void  TAINT_set(bool s)

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

            bool  TAINT_WARN_get()

       "TAINT_WARN_set"
           "s" being true indicates ""TAINT_WARN_get"" should return that tainting violations are
           just warnings

           "s" being false indicates ""TAINT_WARN_get"" should return that tainting violations
           are fatal.

            void  TAINT_WARN_set(bool s)

Time

       There are currently no internal API items in Time

Typedef names

       There are currently no internal API items in Typedef names

Unicode Support

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

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

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

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

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

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

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

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

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

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

           Find the name of the undefined variable (if any) that caused the operator to issue a
           "Use of uninitialized value" warning.  If match is true, only return a name if its
           value matches "uninit_sv".  So roughly speaking, if a unary operator (such as
           "OP_COS") generates a warning, then following the direct child of the op may yield an
           "OP_PADSV" or "OP_GV" that gives the name of the undefined variable.  On the other
           hand, with "OP_ADD" there are two branches to follow, so we only print the variable
           name if we get an exact match.  "desc_p" points to a string pointer holding the
           description of the op.  This may be updated if needed.

           The name is returned as a mortal SV.

           Assumes that "PL_op" is the OP that originally triggered the error, and that
           "PL_comppad"/"PL_curpad" points to the currently executing pad.

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

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

           For example, if all the characters in the sequence are Greek, or Common, or Inherited,
           this function will return TRUE, provided any decimal digits in it are from the same
           block of digits in Common.  (These are the ASCII digits "0".."9" and additionally a
           block for full width forms of these, and several others used in mathematical
           notation.)   For scripts (unlike Greek) that have their own digits defined this will
           accept either digits from that set or from one of the Common digit sets, but not a
           combination of the two.  Some scripts, such as Arabic, have more than one set of
           digits.  All digits must come from the same set for this function to return TRUE.

           *ret_script, if "ret_script" is not NULL, will on return of TRUE contain the script
           found, using the "SCX_enum" typedef.  Its value will be "SCX_INVALID" if the function
           returns FALSE.

           If the sequence is empty, TRUE is returned, but *ret_script (if asked for) will be
           "SCX_INVALID".

           If the sequence contains a single code point which is unassigned to a character in the
           version of Unicode being used, the function will return TRUE, and the script will be
           "SCX_Unknown".  Any other combination of unassigned code points in the input sequence
           will result in the function treating the input as not being a script run.

           The returned script will be "SCX_Inherited" iff all the code points in it are from the
           Inherited script.

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

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

       "is_utf8_non_invariant_string"
           Returns TRUE if "is_utf8_invariant_string" in perlapi returns FALSE for the first
           "len" bytes of the string "s", but they are, nonetheless, legal Perl-extended UTF-8;
           otherwise returns FALSE.

           A TRUE return means that at least one code point represented by the sequence either is
           a wide character not representable as a single byte, or the representation differs
           depending on whether the sequence is encoded in UTF-8 or not.

           See also ""is_utf8_invariant_string" in perlapi", ""is_utf8_string" in perlapi"

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

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

           Instead use "utf8_to_uvchr_buf" in perlapi, or rarely, "utf8n_to_uvchr" in perlapi.

           This function was useful for code that wanted to handle both EBCDIC and ASCII
           platforms with Unicode properties, but starting in Perl v5.20, the distinctions
           between the platforms have mostly been made invisible to most code, so this function
           is quite unlikely to be what you want.  If you do need this precise functionality, use
           instead "NATIVE_TO_UNI(utf8_to_uvchr_buf(...))"  or
           "NATIVE_TO_UNI(utf8n_to_uvchr(...))".

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

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

           Returns the Unicode code point of the first character in the string "s" which is
           assumed to be in UTF-8 encoding; "retlen" will be set to the length, in bytes, of that
           character.

           Some, but not all, UTF-8 malformations are detected, and in fact, some malformed input
           could cause reading beyond the end of the input buffer, which is one reason why this
           function is deprecated.  The other is that only in extremely limited circumstances
           should the Unicode versus native code point be of any interest to you.

           If "s" points to one of the detected malformations, and UTF8 warnings are enabled,
           zero is returned and *retlen is set (if "retlen" doesn't point to NULL) to -1.  If
           those warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT
           CHARACTER, if not) is silently returned, and *retlen is set (if "retlen" isn't NULL)
           so that ("s" + *retlen) is the next possible position in "s" that could begin a non-
           malformed character.  See "utf8n_to_uvchr" in perlapi for details on when the
           REPLACEMENT CHARACTER is returned.

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

       "uvoffuni_to_utf8_flags"
           THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.  Instead, Almost
           all code should use "uvchr_to_utf8" in perlapi or "uvchr_to_utf8_flags" in perlapi.

           This function is like them, but the input is a strict Unicode (as opposed to native)
           code point.  Only in very rare circumstances should code not be using the native code
           point.

           For details, see the description for "uvchr_to_utf8_flags" in perlapi.

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

       "valid_utf8_to_uvchr"
           Like ""utf8_to_uvchr_buf" in perlapi", but should only be called when it is known that
           the next character in the input UTF-8 string "s" is well-formed (e.g., it passes
           ""isUTF8_CHAR" in perlapi".  Surrogates, non-character code points, and non-Unicode
           code points are allowed.

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

       "variant_under_utf8_count"
           This function looks at the sequence of bytes between "s" and "e", which are assumed to
           be encoded in ASCII/Latin1, and returns how many of them would change should the
           string be translated into UTF-8.  Due to the nature of UTF-8, each of these would
           occupy two bytes instead of the single one in the input string.  Thus, this function
           returns the precise number of bytes the string would expand by when translated to
           UTF-8.

           Unlike most of the other functions that have "utf8" in their name, the input to this
           function is NOT a UTF-8-encoded string.  The function name is slightly odd to
           emphasize this.

           This function is internal to Perl because khw thinks that any XS code that would want
           this is probably operating too close to the internals.  Presenting a valid use case
           could change that.

           See also ""is_utf8_invariant_string" in perlapi" and ""is_utf8_invariant_string_loc"
           in perlapi",

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

Utility Functions

       "my_popen_list"
           Implementing function on some systems for PerlProc_popen_list()

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

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

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

Versioning

       There are currently no internal API items in Versioning

Warning and Dieing

       "deprecate"
           Wrapper around Perl_ck_warner_d() to produce a deprecated warning in the given
           category with an appropriate message. The "message" argument must be a C string. The
           string " is deprecated" will automatically be added to the end of the "message".

              deprecate(U32 category, "message")

       "deprecate_disappears_in"
           Wrapper around Perl_ck_warner_d() to produce a deprecated warning in the given
           category with an appropriate message that the construct referred to by the message
           will disappear in a specific release.  The "when" and "message" arguments must be a C
           string.  The "when" string is expected to be of the form "5.40", with no minor element
           in the version.  The actual message output will be the result of the following
           expression "message " is deprecated, and will disappear in Perl " when" which is why
           "message" and "when" must be literal C strings.

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

       "deprecate_fatal_in"
           Wrapper around Perl_ck_warner_d() to produce a deprecated warning in the given
           category with an appropriate message that the construct referred to by the message
           will become fatal in a specific release.  The "when" and "message" arguments must be a
           C string.  The "when" string is expected to be of the form "5.40", with no minor
           element in the version.  The actual message output will be the result of the following
           expression "message " is deprecated, and will become fatal in Perl " when" which is
           why "message" and "when" must be literal C strings.

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

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

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

            U8  PL_dowarn

       "report_uninit"
           Print appropriate "Use of uninitialized variable" warning.

            void  report_uninit(const SV *uninit_sv)

XS

       There are currently no internal API items in XS

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.

        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_lock
        atfork_unlock
        av_arylen_p
        av_extend_guts
        av_iter_p
        av_nonelem
        av_reify
        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_anoncode
        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_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
        cmpchain_extend
        cmpchain_finish
        cmpchain_start
        cmp_desc
        cmp_locale_desc
        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
        cvgv_from_hek
        cvgv_set
        cvstash_set
        cv_undef_flags
        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
        does_utf8_overflow
        do_exec
        do_exec3
        dofile
        do_gv_dump
        do_gvgv_dump
        do_hv_dump
        doing_taint
        do_ipcctl
        do_ipcget
        do_magic_dump
        do_msgrcv
        do_msgsnd
        do_ncmp
        do_op_dump
        do_pmop_dump
        do_print
        do_readline
        doref
        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
        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
        dumpuntil
        dump_vindent
        dup_warnings
        find_first_differing_byte_pos
        find_lexical_cv
        find_runcv_where
        find_script
        finish_export_lexical
        foldEQ_latin1_s2_folded
        foldEQ_latin1
        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
        getenv_len
        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_regclass_aux_data
        get_re_gclass_aux_data
        get_regex_charset_name
        get_win32_message_utf8ness
        gp_free
        gp_ref
        grok_bin_oct_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
        _invlistEQ
        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
        invmap_dump
        invoke_exception_hook
        io_close
        isFF_overlong
        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_common
        is_utf8_FF_helper_
        _is_utf8_FOO
        is_utf8_overlong
        _is_utf8_perl_idcont
        _is_utf8_perl_idstart
        jmaybe
        join_exact
        keyword
        keyword_plugin_standard
        list
        load_charnames
        locale_panic
        localize
        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
        malloced_size
        malloc_good_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_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
        newFORM
        _new_invlist
        _new_invlist_C_array
        newMETHOP_internal
        newPROG
        new_stackinfo
        new_stackinfo_flags
        newSTUB
        newSVavdefelem
        newXS_deffile
        nextargv
        no_bareword_allowed
        no_bareword_filehandle
        noperl_die
        notify_parser_that_changed_to_utf8
        oopsAV
        oopsHV
        op_clear
        op_integerize
        op_lvalue_flags
        opmethod_stash
        op_prune_chain_head
        op_relocate_sv
        opslab_force_free
        opslab_free
        opslab_free_nopad
        op_std_init
        op_varname
        package
        package_version
        pad_add_weakref
        padlist_store
        padname_free
        PadnameIN_SCOPE
        padnamelist_free
        parser_dup
        parser_free
        parser_free_nexttoke_ops
        parse_unicode_opts
        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
        ptr_hash
        qerror
        ReANY
        reentrant_free
        reentrant_init
        reentrant_retry
        reentrant_size
        re_exec_indentf
        ref
        reg_add_data
        regcurly
        regdump
        regdupe_internal
        regexec_flags
        regfree_internal
        reginitcolors
        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
        regnext
        regnode_after
        reg_numbered_buff_fetch
        reg_numbered_buff_fetch_flags
        reg_numbered_buff_length
        reg_numbered_buff_store
        regprop
        reg_qr_package
        reg_skipcomment
        reg_temp_copy
        re_indentf
        re_intuit_start
        re_intuit_string
        re_op_compile
        report_evil_fh
        report_redefined_cv
        report_wrongway_fh
        re_printf
        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
        savestack_grow
        savestack_grow_cnt
        save_strlen
        sawparens
        scalar
        scalarvoid
        scan_commit
        scan_num
        seed
        set_ANYOF_arg
        set_caret_X
        setfd_cloexec
        setfd_cloexec_for_nonsysfd
        setfd_cloexec_or_inhexec_by_sysfdness
        setfd_inhexec
        setfd_inhexec_for_sysfd
        set_numeric_standard
        set_numeric_underlying
        set_padlist
        _setup_canned_invlist
        share_hek
        should_warn_nl
        should_we_output_Debug_r
        sighandler
        sighandler1
        sighandler3
        single_1bit_pos32
        single_1bit_pos64
        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
        sv_add_backref
        sv_buf_to_ro
        sv_del_backref
        sv_i_ncmp
        sv_i_ncmp_desc
        sv_2iv
        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
        SvTRUE_common
        sv_unglob
        sv_2uv
        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
        TOPMARK
        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
        translate_substr_offsets
        try_amagic_bin
        try_amagic_un
        uiv_2buf
        unlnk
        unshare_hek
        unwind_paren
        _utf8n_to_uvchr_msgs_helper
        utf16_to_utf8_base
        utf16_to_utf8_reversed
        utf16_to_utf8
        utf8_to_uvchr_buf_helper
        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_handshake
        yyerror
        yyerror_pv
        yyerror_pvn
        yylex
        yyparse
        yyquit
        yyunlex

       Next are the experimental undocumented elements

        alloc_LOGOP            gimme_V
        av_remove_offset       hv_backreferences_p
        clear_defarray_simple  hv_kill_backrefs
        create_eval_scope      invlist_highest_range_start
        cv_ckproto_len_flags   invlist_lowest
        cx_popblock            newGP
        cx_popeval             new_warnings_bitfield
        cx_popformat           op_refcnt_dec
        cx_popgiven            op_refcnt_inc
        cx_poploop             op_unscope
        cx_popsub              pop_stackinfo
        cx_popsub_args         pp_wrap
        cx_popsub_common       push_stackinfo
        cx_popwhen             rpp_free_2_
        cx_pushblock           rpp_obliterate_stack_to
        cx_pusheval            rpp_replace_2_1_COMMON
        cx_pushformat          runops_wrap
        cx_pushgiven           scan_str
        cx_pushloop_for        scan_word
        cx_pushloop_plain      scan_word6
        cx_pushsub             skipspace_flags
        cx_pushtry             sv_free2
        cx_pushwhen            sv_kill_backrefs
        cx_topblock            sv_setpv_freshbuf
        delete_eval_scope      sv_setsv_cow
        do_open_raw            sv_strftime_ints
        do_open6               switch_argstack
        emulate_cop_io         utf8_to_utf16_base
        get_re_arg             xs_wrap
        get_vtbl

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

        get_no_modify  get_opargs  get_ppaddr  uvuni_to_utf8

AUTHORS

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

SEE ALSO

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