man > PERLINTERN(1)

PERLINTERN(1)                     Perl Programmers Reference Guide                     PERLINTERN(1)

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
           SAVEDESTRUCTORX() 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
           get added to "name".  None of the other processing of "pad_add_name_pvn"  in  perlapi  is
           done.  Returns the offset of the allocated pad slot.

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

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

            void  pad_block_start(int full)

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

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

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

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

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

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

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

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

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

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

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

            void  pad_free(PADOFFSET po)

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

            OP *  pad_leavemy()

       "padlist_dup"
           Duplicates a pad.

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

       "padname_dup"
           Duplicates a pad name.

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

       "padnamelist_dup"
           Duplicates a pad name list.

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

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

            void  pad_push(PADLIST *padlist, int depth)

       "pad_reset"
           Mark all the current temporaries for reuse

            void  pad_reset()

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

            void  pad_setsv(PADOFFSET po, SV *sv)

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

            SV *  pad_sv(PADOFFSET po)

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

            void  pad_swipe(PADOFFSET po, bool refadjust)

       "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)

       "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

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.

            I32  sv_clean_all()

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

            void  sv_clean_objs()

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

            void  sv_free_arenas()

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

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

       "sv_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_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_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
        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
        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_ssc_worth_it
        _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_strftime8_temp
        my_unexec
        newFORM
        _new_invlist
        _new_invlist_C_array
        newMETHOP_internal
        newMYSUB
        newPROG
        new_stackinfo
        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
        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_finalize
        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_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
        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
        uvuni_to_utf8
        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           cx_pushloop_for              invlist_lowest
        create_eval_scope     cx_pushloop_plain            newGP
        cv_ckproto_len_flags  cx_pushsub                   new_warnings_bitfield
        cx_popblock           cx_pushtry                   op_refcnt_dec
        cx_popeval            cx_pushwhen                  op_refcnt_inc
        cx_popformat          cx_topblock                  op_unscope
        cx_popgiven           delete_eval_scope            scan_str
        cx_poploop            do_open_raw                  scan_word
        cx_popsub             do_open6                     scan_word6
        cx_popsub_args        emulate_cop_io               skipspace_flags
        cx_popsub_common      get_re_arg                   sv_free2
        cx_popwhen            get_vtbl                     sv_kill_backrefs
        cx_pushblock          gimme_V                      sv_setpv_freshbuf
        cx_pusheval           hv_backreferences_p          sv_setsv_cow
        cx_pushformat         hv_kill_backrefs             utf8_to_utf16_base
        cx_pushgiven          invlist_highest_range_start

       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

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

perl v5.38.2                                 2026-08-18                                PERLINTERN(1)
PERLINTERN(1) □✕
NAME DESCRIPTION Callback Functions Casting Character case changing Character classification Compiler and Preprocessor information Compiler directives Compile-time scope hooks Concurrency Custom Operators Debugging Display functions Embedding, Threads, and Interpreter Cloning Errno Exception Handling (simple) Macros Filesystem configuration values Floating point General Configuration Global Variables Hook manipulation Input/Output Integer Lexer interface Locales Magic Memory Management MRO Multicall Functions Numeric Functions Optrees Pad Data Structures Password and Group access Paths to system commands Prototype information Reports and Formats Signals Site configuration Sockets configuration values Source Filters Stack Manipulation Macros String Handling Tainting Time Typedef names Unicode Support Utility Functions Versioning Warning and Dieing Undocumented elements AUTHORS SEE ALSO

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