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PERLAPI(1)			 Perl Programmers Reference Guide		       PERLAPI(1)

NAME
       perlapi - autogenerated documentation for the perl public API

DESCRIPTION
       This file contains the documentation of the perl public API generated by embed.pl,
       specifically a listing of functions, macros, flags, and variables that may be used by
       extension writers.  At the end is a list of functions which have yet to be documented.
       The interfaces of those are subject to change without notice.  Any functions not listed
       here are not part of the public API, and should not be used by extension writers at all.
       For these reasons, blindly using functions listed in proto.h is to be avoided when writing
       extensions.

       Note that all Perl API global variables must be referenced with the "PL_" prefix.  Some
       macros are provided for compatibility with the older, unadorned names, but this support
       may be disabled in a future release.

       Perl was originally written to handle US-ASCII only (that is characters whose ordinal
       numbers are in the range 0 - 127).  And documentation and comments may still use the term
       ASCII, when sometimes in fact the entire range from 0 - 255 is meant.

       Note that Perl can be compiled and run under EBCDIC (See perlebcdic) or ASCII.  Most of
       the documentation (and even comments in the code) ignore the EBCDIC possibility.  For
       almost all purposes the differences are transparent.  As an example, under EBCDIC, instead
       of UTF-8, UTF-EBCDIC is used to encode Unicode strings, and so whenever this documentation
       refers to "utf8" (and variants of that name, including in function names), it also
       (essentially transparently) means "UTF-EBCDIC".	But the ordinals of characters differ
       between ASCII, EBCDIC, and the UTF- encodings, and a string encoded in UTF-EBCDIC may
       occupy more bytes than in UTF-8.

       Also, on some EBCDIC machines, functions that are documented as operating on US-ASCII (or
       Basic Latin in Unicode terminology) may in fact operate on all 256 characters in the
       EBCDIC range, not just the subset corresponding to US-ASCII.

       The listing below is alphabetical, case insensitive.

"Gimme" Values
       GIMME   A backward-compatible version of "GIMME_V" which can only return "G_SCALAR" or
	       "G_ARRAY"; in a void context, it returns "G_SCALAR".  Deprecated.  Use "GIMME_V"
	       instead.

		       U32     GIMME

       GIMME_V The XSUB-writer's equivalent to Perl's "wantarray".  Returns "G_VOID", "G_SCALAR"
	       or "G_ARRAY" for void, scalar or list context, respectively. See perlcall for a
	       usage example.

		       U32     GIMME_V

       G_ARRAY Used to indicate list context.  See "GIMME_V", "GIMME" and perlcall.

       G_DISCARD
	       Indicates that arguments returned from a callback should be discarded.  See
	       perlcall.

       G_EVAL  Used to force a Perl "eval" wrapper around a callback.  See perlcall.

       G_NOARGS
	       Indicates that no arguments are being sent to a callback.  See perlcall.

       G_SCALAR
	       Used to indicate scalar context.  See "GIMME_V", "GIMME", and perlcall.

       G_VOID  Used to indicate void context.  See "GIMME_V" and perlcall.

Array Manipulation Functions
       AvFILL  Same as "av_len()".  Deprecated, use "av_len()" instead.

		       int     AvFILL(AV* av)

       av_clear
	       Clears an array, making it empty.  Does not free the memory the av uses to store
	       its list of scalars.  If any destructors are triggered as a result, the av itself
	       may be freed when this function returns.

	       Perl equivalent: "@myarray = ();".

		       void    av_clear(AV *av)

       av_create_and_push
	       Push an SV onto the end of the array, creating the array if necessary.  A small
	       internal helper function to remove a commonly duplicated idiom.

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

		       void    av_create_and_push(AV **const avp,
						  SV *const val)

       av_create_and_unshift_one
	       Unshifts an SV onto the beginning of the array, creating the array if necessary.
	       A small internal helper function to remove a commonly duplicated idiom.

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

		       SV**    av_create_and_unshift_one(AV **const avp,
							 SV *const val)

       av_delete
	       Deletes the element indexed by "key" from the array, makes the element mortal, and
	       returns it.  If "flags" equals "G_DISCARD", the element is freed and null is
	       returned.  Perl equivalent: "my $elem = delete($myarray[$idx]);" for the
	       non-"G_DISCARD" version and a void-context "delete($myarray[$idx]);" for the
	       "G_DISCARD" version.

		       SV*     av_delete(AV *av, I32 key, I32 flags)

       av_exists
	       Returns true if the element indexed by "key" has been initialized.

	       This relies on the fact that uninitialized array elements are set to &PL_sv_undef.

	       Perl equivalent: "exists($myarray[$key])".

		       bool    av_exists(AV *av, I32 key)

       av_extend
	       Pre-extend an array.  The "key" is the index to which the array should be
	       extended.

		       void    av_extend(AV *av, I32 key)

       av_fetch
	       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*".

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied arrays.

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

		       SV**    av_fetch(AV *av, I32 key, I32 lval)

       av_fill Set the highest index in the array to the given number, equivalent to Perl's
	       "$#array = $fill;".

	       The number of elements in the an array will be "fill + 1" after av_fill() returns.
	       If the array was previously shorter, then the additional elements appended are set
	       to "PL_sv_undef".  If the array was longer, then the excess elements are freed.
	       "av_fill(av, -1)" is the same as "av_clear(av)".

		       void    av_fill(AV *av, I32 fill)

       av_len  Returns the highest index in the array.	The number of elements in the array is
	       "av_len(av) + 1".  Returns -1 if the array is empty.

	       The Perl equivalent for this is $#myarray.

		       I32     av_len(AV *av)

       av_make Creates a new AV and populates it with a list of SVs.  The SVs are copied into the
	       array, so they may be freed after the call to av_make.  The new AV will have a
	       reference count of 1.

	       Perl equivalent: "my @new_array = ($scalar1, $scalar2, $scalar3...);"

		       AV*     av_make(I32 size, SV **strp)

       av_pop  Pops an SV off the end of the array.  Returns &PL_sv_undef if the array is empty.

	       Perl equivalent: "pop(@myarray);"

		       SV*     av_pop(AV *av)

       av_push Pushes an SV onto the end of the array.	The array will grow automatically to
	       accommodate the addition.  This takes ownership of one reference count.

	       Perl equivalent: "push @myarray, $elem;".

		       void    av_push(AV *av, SV *val)

       av_shift
	       Shifts an SV off the beginning of the array.  Returns &PL_sv_undef if the array is
	       empty.

	       Perl equivalent: "shift(@myarray);"

		       SV*     av_shift(AV *av)

       av_store
	       Stores an SV in an array.  The array index is specified as "key".  The return
	       value will be NULL if the operation failed or if the value did not need to be
	       actually stored within the array (as in the case of tied arrays). Otherwise, 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, and decrementing it if the function returned NULL.

	       Approximate Perl equivalent: "$myarray[$key] = $val;".

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied arrays.

		       SV**    av_store(AV *av, I32 key, SV *val)

       av_undef
	       Undefines the array.  Frees the memory used by the av to store its list of
	       scalars.  If any destructors are triggered as a result, the av itself may be
	       freed.

		       void    av_undef(AV *av)

       av_unshift
	       Unshift the given number of "undef" values onto the beginning of the array.  The
	       array will grow automatically to accommodate the addition.  You must then use
	       "av_store" to assign values to these new elements.

	       Perl equivalent: "unshift @myarray, ( (undef) x $n );"

		       void    av_unshift(AV *av, I32 num)

       get_av  Returns the AV of the specified Perl global or package array with the given name
	       (so it won't work on lexical variables).  "flags" are passed to "gv_fetchpv". If
	       "GV_ADD" is set and the Perl variable does not exist then it will be created.  If
	       "flags" is zero and the variable does not exist then NULL is returned.

	       Perl equivalent: "@{"$name"}".

	       NOTE: the perl_ form of this function is deprecated.

		       AV*     get_av(const char *name, I32 flags)

       newAV   Creates a new AV.  The reference count is set to 1.

	       Perl equivalent: "my @array;".

		       AV*     newAV()

       sortsv  Sort an array. Here is an example:

		   sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale);

	       Currently this always uses mergesort. See sortsv_flags for a more flexible
	       routine.

		       void    sortsv(SV** array, size_t num_elts,
				      SVCOMPARE_t cmp)

       sortsv_flags
	       Sort an array, with various options.

		       void    sortsv_flags(SV** array, size_t num_elts,
					    SVCOMPARE_t cmp, U32 flags)

Callback Functions
       call_argv
	       Performs a callback to the specified named and package-scoped Perl subroutine with
	       "argv" (a NULL-terminated array of strings) as arguments. See perlcall.

	       Approximate Perl equivalent: "&{"$sub_name"}(@$argv)".

	       NOTE: the perl_ form of this function is deprecated.

		       I32     call_argv(const char* sub_name, I32 flags,
					 char** argv)

       call_method
	       Performs a callback to the specified Perl method.  The blessed object must be on
	       the stack.  See perlcall.

	       NOTE: the perl_ form of this function is deprecated.

		       I32     call_method(const char* methname, I32 flags)

       call_pv Performs a callback to the specified Perl sub.  See perlcall.

	       NOTE: the perl_ form of this function is deprecated.

		       I32     call_pv(const char* sub_name, I32 flags)

       call_sv Performs a callback to the Perl sub whose name is in the SV.  See perlcall.

	       NOTE: the perl_ form of this function is deprecated.

		       I32     call_sv(SV* sv, VOL I32 flags)

       ENTER   Opening bracket on a callback.  See "LEAVE" and perlcall.

			       ENTER;

       eval_pv Tells Perl to "eval" the given string and return an SV* result.

	       NOTE: the perl_ form of this function is deprecated.

		       SV*     eval_pv(const char* p, I32 croak_on_error)

       eval_sv Tells Perl to "eval" the string in the SV. It supports the same flags as
	       "call_sv", with the obvious exception of G_EVAL. See perlcall.

	       NOTE: the perl_ form of this function is deprecated.

		       I32     eval_sv(SV* sv, I32 flags)

       FREETMPS
	       Closing bracket for temporaries on a callback.  See "SAVETMPS" and perlcall.

			       FREETMPS;

       LEAVE   Closing bracket on a callback.  See "ENTER" and perlcall.

			       LEAVE;

       SAVETMPS
	       Opening bracket for temporaries on a callback.  See "FREETMPS" and perlcall.

			       SAVETMPS;

Character case changing
       toLOWER Converts the specified character to lowercase in the platform's native character
	       set, if possible; otherwise returns the input character itself.

		       char    toLOWER(char ch)

       toUPPER Converts the specified character to uppercase in the platform's native character
	       set, if possible; otherwise returns the input character itself.

		       char    toUPPER(char ch)

Character classes
       There are three variants for all the functions in this section.	The base ones operate
       using the character set of the platform Perl is running on.  The ones with an "_A" suffix
       operate on the ASCII character set, and the ones with an "_L1" suffix operate on the full
       Latin1 character set.  All are unaffected by locale and by "use bytes".

       For ASCII platforms, the base function with no suffix and the one with the "_A" suffix are
       identical.  The function with the "_L1" suffix imposes the Latin-1 character set onto the
       platform.  That is, the code points that are ASCII are unaffected, since ASCII is a subset
       of Latin-1.  But the non-ASCII code points are treated as if they are Latin-1 characters.
       For example, "isSPACE_L1()" will return true when called with the code point 0xA0, which
       is the Latin-1 NO-BREAK SPACE.

       For EBCDIC platforms, the base function with no suffix and the one with the "_L1" suffix
       should be identical, since, as of this writing, the EBCDIC code pages that Perl knows
       about all are equivalent to Latin-1.  The function that ends in an "_A" suffix will not
       return true unless the specified character also has an ASCII equivalent.

       isALPHA Returns a boolean indicating whether the specified character is an alphabetic
	       character in the platform's native character set.  See the top of this section for
	       an explanation of variants "isALPHA_A" and "isALPHA_L1".

		       bool    isALPHA(char ch)

       isASCII Returns a boolean indicating whether the specified character is one of the 128
	       characters in the ASCII character set.  On non-ASCII platforms, it is if this
	       character corresponds to an ASCII character.  Variants "isASCII_A()" and
	       "isASCII_L1()" are identical to "isASCII()".

		       bool    isASCII(char ch)

       isDIGIT Returns a boolean indicating whether the specified character is a digit in the
	       platform's native character set.  Variants "isDIGIT_A" and "isDIGIT_L1" are
	       identical to "isDIGIT".

		       bool    isDIGIT(char ch)

       isLOWER Returns a boolean indicating whether the specified character is a lowercase
	       character in the platform's native character set.  See the top of this section for
	       an explanation of variants "isLOWER_A" and "isLOWER_L1".

		       bool    isLOWER(char ch)

       isOCTAL Returns a boolean indicating whether the specified character is an octal digit,
	       [0-7] in the platform's native character set.  Variants "isOCTAL_A" and
	       "isOCTAL_L1" are identical to "isOCTAL".

		       bool    isOCTAL(char ch)

       isSPACE Returns a boolean indicating whether the specified character is a whitespace
	       character in the platform's native character set.  This is the same as what "\s"
	       matches in a regular expression.  See the top of this section for an explanation
	       of variants "isSPACE_A" and "isSPACE_L1".

		       bool    isSPACE(char ch)

       isUPPER Returns a boolean indicating whether the specified character is an uppercase
	       character in the platform's native character set.  See the top of this section for
	       an explanation of variants "isUPPER_A" and "isUPPER_L1".

		       bool    isUPPER(char ch)

       isWORDCHAR
	       Returns a boolean indicating whether the specified character is a character that
	       is any of: alphabetic, numeric, or an underscore.  This is the same as what "\w"
	       matches in a regular expression.  "isALNUM()" is a synonym provided for backward
	       compatibility.  Note that it does not have the standard C language meaning of
	       alphanumeric, since it matches an underscore and the standard meaning does not.
	       See the top of this section for an explanation of variants "isWORDCHAR_A" and
	       "isWORDCHAR_L1".

		       bool    isWORDCHAR(char ch)

       isXDIGIT
	       Returns a boolean indicating whether the specified character is a hexadecimal
	       digit, [0-9A-Fa-f].  Variants "isXDIGIT_A()" and "isXDIGIT_L1()" are identical to
	       "isXDIGIT()".

		       bool    isXDIGIT(char ch)

Cloning an interpreter
       perl_clone
	       Create and return a new interpreter by cloning the current one.

	       perl_clone takes these flags as parameters:

	       CLONEf_COPY_STACKS - is used to, well, copy the stacks also, without it we only
	       clone the data and zero the stacks, with it we copy the stacks and the new perl
	       interpreter is ready to run at the exact same point as the previous one.  The
	       pseudo-fork code uses COPY_STACKS while the threads->create doesn't.

	       CLONEf_KEEP_PTR_TABLE - perl_clone keeps a ptr_table with the pointer of the old
	       variable as a key and the new variable as a value, this allows it to check if
	       something has been cloned and not clone it again but rather just use the value and
	       increase the refcount.  If KEEP_PTR_TABLE is not set then perl_clone will kill the
	       ptr_table using the function "ptr_table_free(PL_ptr_table); PL_ptr_table = NULL;",
	       reason to keep it around is if you want to dup some of your own variable who are
	       outside the graph perl scans, example of this code is in threads.xs create.

	       CLONEf_CLONE_HOST - This is a win32 thing, it is ignored on unix, it tells perls
	       win32host code (which is c++) to clone itself, this is needed on win32 if you want
	       to run two threads at the same time, if you just want to do some stuff in a
	       separate perl interpreter and then throw it away and return to the original one,
	       you don't need to do anything.

		       PerlInterpreter* perl_clone(
					    PerlInterpreter *proto_perl,
					    UV flags
					)

Compile-time scope hooks
       BhkDISABLE
	       Temporarily disable an entry in this BHK structure, by clearing the appropriate
	       flag. which is a preprocessor token indicating which entry to disable.

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

		       void    BhkDISABLE(BHK *hk, which)

       BhkENABLE
	       Re-enable an entry in this BHK structure, by setting the appropriate flag. which
	       is a preprocessor token indicating which entry to enable.  This will assert (under
	       -DDEBUGGING) if the entry doesn't contain a valid pointer.

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

		       void    BhkENABLE(BHK *hk, which)

       BhkENTRY_set
	       Set an entry in the BHK structure, and set the flags to indicate it is valid.
	       which is a preprocessing token indicating which entry to set.  The type of ptr
	       depends on the entry.

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

		       void    BhkENTRY_set(BHK *hk, which, void *ptr)

       blockhook_register
	       Register a set of hooks to be called when the Perl lexical scope changes at
	       compile time. See "Compile-time scope hooks" in perlguts.

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

	       NOTE: this function must be explicitly called as Perl_blockhook_register with an
	       aTHX_ parameter.

		       void    Perl_blockhook_register(pTHX_ BHK *hk)

COP Hint Hashes
       cophh_2hv
	       Generates and returns a standard Perl hash representing the full set of key/value
	       pairs in the cop hints hash cophh.  flags is currently unused and must be zero.

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

		       HV *    cophh_2hv(const COPHH *cophh, U32 flags)

       cophh_copy
	       Make and return a complete copy of the cop hints hash cophh.

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

		       COPHH * cophh_copy(COPHH *cophh)

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

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

		       COPHH * cophh_delete_pv(const COPHH *cophh,
					       const char *key, U32 hash,
					       U32 flags)

       cophh_delete_pvn
	       Delete a key and its associated value from the cop hints hash cophh, and returns
	       the modified hash.  The returned hash pointer is in general not the same as the
	       hash pointer that was passed in.  The input hash is consumed by the function, and
	       the pointer to it must not be subsequently used.  Use "cophh_copy" if you need
	       both hashes.

	       The key is specified by keypv and keylen.  If flags has the "COPHH_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.

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

		       COPHH * cophh_delete_pvn(COPHH *cophh,
						const char *keypv,
						STRLEN keylen, U32 hash,
						U32 flags)

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

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

		       COPHH * cophh_delete_pvs(const COPHH *cophh,
						const char *key, U32 flags)

       cophh_delete_sv
	       Like "cophh_delete_pvn", but takes a Perl scalar instead of a string/length pair.

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

		       COPHH * cophh_delete_sv(const COPHH *cophh, SV *key,
					       U32 hash, U32 flags)

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

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

		       SV *    cophh_fetch_pv(const COPHH *cophh,
					      const char *key, U32 hash,
					      U32 flags)

       cophh_fetch_pvn
	       Look up the entry in the cop hints hash cophh with the key specified by keypv and
	       keylen.	If flags has the "COPHH_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 copy of the value associated with the key, or &PL_sv_placeholder if there
	       is no value associated with the key.

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

		       SV *    cophh_fetch_pvn(const COPHH *cophh,
					       const char *keypv,
					       STRLEN keylen, U32 hash,
					       U32 flags)

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

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

		       SV *    cophh_fetch_pvs(const COPHH *cophh,
					       const char *key, U32 flags)

       cophh_fetch_sv
	       Like "cophh_fetch_pvn", but takes a Perl scalar instead of a string/length pair.

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

		       SV *    cophh_fetch_sv(const COPHH *cophh, SV *key,
					      U32 hash, U32 flags)

       cophh_free
	       Discard the cop hints hash cophh, freeing all resources associated with it.

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

		       void    cophh_free(COPHH *cophh)

       cophh_new_empty
	       Generate and return a fresh cop hints hash containing no entries.

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

		       COPHH * cophh_new_empty()

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

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

		       COPHH * cophh_store_pv(const COPHH *cophh,
					      const char *key, U32 hash,
					      SV *value, U32 flags)

       cophh_store_pvn
	       Stores a value, associated with a key, in the cop hints hash cophh, and returns
	       the modified hash.  The returned hash pointer is in general not the same as the
	       hash pointer that was passed in.  The input hash is consumed by the function, and
	       the pointer to it must not be subsequently used.  Use "cophh_copy" if you need
	       both hashes.

	       The key is specified by keypv and keylen.  If flags has the "COPHH_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 cop hints
	       hash.  Complex types of scalar will not be stored with referential integrity, but
	       will be coerced to strings.

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

		       COPHH * cophh_store_pvn(COPHH *cophh, const char *keypv,
					       STRLEN keylen, U32 hash,
					       SV *value, U32 flags)

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

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

		       COPHH * cophh_store_pvs(const COPHH *cophh,
					       const char *key, SV *value,
					       U32 flags)

       cophh_store_sv
	       Like "cophh_store_pvn", but takes a Perl scalar instead of a string/length pair.

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

		       COPHH * cophh_store_sv(const COPHH *cophh, SV *key,
					      U32 hash, SV *value, U32 flags)

COP Hint Reading
       cop_hints_2hv
	       Generates and returns a standard Perl hash representing the full set of hint
	       entries in the cop cop.	flags is currently unused and must be zero.

		       HV *    cop_hints_2hv(const COP *cop, U32 flags)

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

		       SV *    cop_hints_fetch_pv(const COP *cop,
						  const char *key, U32 hash,
						  U32 flags)

       cop_hints_fetch_pvn
	       Look up the hint entry in the cop cop with the key specified by keypv and keylen.
	       If flags has the "COPHH_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
	       copy of the value associated with the key, or &PL_sv_placeholder if there is no
	       value associated with the key.

		       SV *    cop_hints_fetch_pvn(const COP *cop,
						   const char *keypv,
						   STRLEN keylen, U32 hash,
						   U32 flags)

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

		       SV *    cop_hints_fetch_pvs(const COP *cop,
						   const char *key, U32 flags)

       cop_hints_fetch_sv
	       Like "cop_hints_fetch_pvn", but takes a Perl scalar instead of a string/length
	       pair.

		       SV *    cop_hints_fetch_sv(const COP *cop, SV *key,
						  U32 hash, U32 flags)

Custom Operators
       custom_op_register
	       Register a custom op. See "Custom Operators" in perlguts.

	       NOTE: this function must be explicitly called as Perl_custom_op_register with an
	       aTHX_ parameter.

		       void    Perl_custom_op_register(pTHX_
						       Perl_ppaddr_t ppaddr,
						       const XOP *xop)

       custom_op_xop
	       Return the XOP structure for a given custom op. This function should be considered
	       internal to OP_NAME and the other access macros: use them instead.

	       NOTE: this function must be explicitly called as Perl_custom_op_xop with an aTHX_
	       parameter.

		       const XOP * Perl_custom_op_xop(pTHX_ const OP *o)

       XopDISABLE
	       Temporarily disable a member of the XOP, by clearing the appropriate flag.

		       void    XopDISABLE(XOP *xop, which)

       XopENABLE
	       Reenable a member of the XOP which has been disabled.

		       void    XopENABLE(XOP *xop, which)

       XopENTRY
	       Return a member of the XOP structure. which is a cpp token indicating which entry
	       to return. If the member is not set this will return a default value. The return
	       type depends on which.

			       XopENTRY(XOP *xop, which)

       XopENTRY_set
	       Set a member of the XOP structure. which is a cpp token indicating which entry to
	       set. See "Custom Operators" in perlguts for details about the available members
	       and how they are used.

		       void    XopENTRY_set(XOP *xop, which, value)

       XopFLAGS
	       Return the XOP's flags.

		       U32     XopFLAGS(XOP *xop)

CV Manipulation Functions
       CvSTASH Returns the stash of the CV. A stash is the symbol table hash, containing the
	       package-scoped variables in the package where the subroutine was defined.  For
	       more information, see perlguts.

	       This also has a special use with XS AUTOLOAD subs.  See "Autoloading with XSUBs"
	       in perlguts.

		       HV*     CvSTASH(CV* cv)

       get_cv  Uses "strlen" to get the length of "name", then calls "get_cvn_flags".

	       NOTE: the perl_ form of this function is deprecated.

		       CV*     get_cv(const char* name, I32 flags)

       get_cvn_flags
	       Returns the CV of the specified Perl subroutine.  "flags" are passed to
	       "gv_fetchpvn_flags". If "GV_ADD" is set and the Perl subroutine does not exist
	       then it will be declared (which has the same effect as saying "sub name;").  If
	       "GV_ADD" is not set and the subroutine does not exist then NULL is returned.

	       NOTE: the perl_ form of this function is deprecated.

		       CV*     get_cvn_flags(const char* name, STRLEN len,
					     I32 flags)

Embedding Functions
       cv_clone
	       Clone a CV, making a lexical closure.  proto supplies the prototype of the
	       function: its code, pad structure, and other attributes.  The prototype is
	       combined with a capture of outer lexicals to which the code refers, which are
	       taken from the currently-executing instance of the immediately surrounding code.

		       CV *    cv_clone(CV *proto)

       cv_undef
	       Clear out all the active components of a CV. This can happen either by an explicit
	       "undef &foo", or by the reference count going to zero.  In the former case, we
	       keep the CvOUTSIDE pointer, so that any anonymous children can still follow the
	       full lexical scope chain.

		       void    cv_undef(CV* cv)

       find_rundefsv
	       Find and return the variable that is named $_ in the lexical scope of the
	       currently-executing function.  This may be a lexical $_, or will otherwise be the
	       global one.

		       SV *    find_rundefsv()

       find_rundefsvoffset
	       Find the position of the lexical $_ in the pad of the currently-executing
	       function.  Returns the offset in the current pad, or "NOT_IN_PAD" if there is no
	       lexical $_ in scope (in which case the global one should be used instead).
	       "find_rundefsv" is likely to be more convenient.

	       NOTE: the perl_ form of this function is deprecated.

		       PADOFFSET find_rundefsvoffset()

       load_module
	       Loads the module whose name is pointed to by the string part of name.  Note that
	       the actual module name, not its filename, should be given.  Eg, "Foo::Bar" instead
	       of "Foo/Bar.pm".  flags can be any of PERL_LOADMOD_DENY, PERL_LOADMOD_NOIMPORT, or
	       PERL_LOADMOD_IMPORT_OPS (or 0 for no flags). ver, if specified and not NULL,
	       provides version semantics similar to "use Foo::Bar VERSION".  The optional
	       trailing SV* arguments can be used to specify arguments to the module's import()
	       method, similar to "use Foo::Bar VERSION LIST".	They must be terminated with a
	       final NULL pointer.  Note that this list can only be omitted when the
	       PERL_LOADMOD_NOIMPORT flag has been used.  Otherwise at least a single NULL
	       pointer to designate the default import list is required.

	       The reference count for each specified "SV*" parameter is decremented.

		       void    load_module(U32 flags, SV* name, SV* ver, ...)

       nothreadhook
	       Stub that provides thread hook for perl_destruct when there are no threads.

		       int     nothreadhook()

       pad_add_anon
	       Allocates a place in the currently-compiling pad (via "pad_alloc") for an
	       anonymous function that is lexically scoped inside the currently-compiling
	       function.  The function func is linked into the pad, and its "CvOUTSIDE" link to
	       the outer scope is weakened to avoid a reference loop.

	       optype should be an opcode indicating the type of operation that the pad entry is
	       to support.  This doesn't affect operational semantics, but is used for debugging.

		       PADOFFSET pad_add_anon(CV *func, I32 optype)

       pad_add_name_pv
	       Exactly like "pad_add_name_pvn", but takes a nul-terminated string instead of a
	       string/length pair.

		       PADOFFSET pad_add_name_pv(const char *name, U32 flags,
						 HV *typestash, HV *ourstash)

       pad_add_name_pvn
	       Allocates a place in the currently-compiling pad for a named lexical variable.
	       Stores the name and other metadata in the name part of the pad, and makes
	       preparations to manage the variable's lexical scoping.  Returns the offset of the
	       allocated pad slot.

	       namepv/namelen specify the variable's name, including leading sigil.  If typestash
	       is non-null, the name is for a typed lexical, and this identifies the type.  If
	       ourstash is non-null, it's a lexical reference to a package variable, and this
	       identifies the package.	The following flags can be OR'ed together:

		   padadd_OUR	       redundantly specifies if it's a package var
		   padadd_STATE        variable will retain value persistently
		   padadd_NO_DUP_CHECK skip check for lexical shadowing

		       PADOFFSET pad_add_name_pvn(const char *namepv,
						  STRLEN namelen, U32 flags,
						  HV *typestash, HV *ourstash)

       pad_add_name_sv
	       Exactly like "pad_add_name_pvn", but takes the name string in the form of an SV
	       instead of a string/length pair.

		       PADOFFSET pad_add_name_sv(SV *name, U32 flags,
						 HV *typestash, HV *ourstash)

       pad_alloc
	       Allocates a place in the currently-compiling pad, returning the offset of the
	       allocated pad slot.  No name is initially attached to the pad slot.  tmptype is a
	       set of flags indicating the kind of pad entry required, which will be set in the
	       value SV for the allocated pad entry:

		   SVs_PADMY	named lexical variable ("my", "our", "state")
		   SVs_PADTMP	unnamed temporary store

	       optype should be an opcode indicating the type of operation that the pad entry is
	       to support.  This doesn't affect operational semantics, but is used for debugging.

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

		       PADOFFSET pad_alloc(I32 optype, U32 tmptype)

       pad_compname_type
	       Looks up the type of the lexical variable at position po in the currently-
	       compiling pad.  If the variable is typed, the stash of the class to which it is
	       typed is returned.  If not, "NULL" is returned.

		       HV *    pad_compname_type(PADOFFSET po)

       pad_findmy_pv
	       Exactly like "pad_findmy_pvn", but takes a nul-terminated string instead of a
	       string/length pair.

		       PADOFFSET pad_findmy_pv(const char *name, U32 flags)

       pad_findmy_pvn
	       Given the name of a lexical variable, find its position in the currently-compiling
	       pad.  namepv/namelen specify the variable's name, including leading sigil.  flags
	       is reserved and must be zero.  If it is not in the current pad but appears in the
	       pad of any lexically enclosing scope, then a pseudo-entry for it is added in the
	       current pad.  Returns the offset in the current pad, or "NOT_IN_PAD" if no such
	       lexical is in scope.

		       PADOFFSET pad_findmy_pvn(const char *namepv,
						STRLEN namelen, U32 flags)

       pad_findmy_sv
	       Exactly like "pad_findmy_pvn", but takes the name string in the form of an SV
	       instead of a string/length pair.

		       PADOFFSET pad_findmy_sv(SV *name, U32 flags)

       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_tidy
	       Tidy up a pad at the end of compilation of the code to which it belongs.  Jobs
	       performed here are: remove most stuff from the pads of anonsub prototypes; give it
	       a @_; mark temporaries as such.	type indicates the kind of subroutine:

		   padtidy_SUB	      ordinary subroutine
		   padtidy_SUBCLONE   prototype for lexical closure
		   padtidy_FORMAT     format

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

		       void    pad_tidy(padtidy_type type)

       perl_alloc
	       Allocates a new Perl interpreter.  See perlembed.

		       PerlInterpreter* perl_alloc()

       perl_construct
	       Initializes a new Perl interpreter.  See perlembed.

		       void    perl_construct(PerlInterpreter *my_perl)

       perl_destruct
	       Shuts down a Perl interpreter.  See perlembed.

		       int     perl_destruct(PerlInterpreter *my_perl)

       perl_free
	       Releases a Perl interpreter.  See perlembed.

		       void    perl_free(PerlInterpreter *my_perl)

       perl_parse
	       Tells a Perl interpreter to parse a Perl script.  See perlembed.

		       int     perl_parse(PerlInterpreter *my_perl,
					  XSINIT_t xsinit, int argc,
					  char** argv, char** env)

       perl_run
	       Tells a Perl interpreter to run.  See perlembed.

		       int     perl_run(PerlInterpreter *my_perl)

       require_pv
	       Tells Perl to "require" the file named by the string argument.  It is analogous to
	       the Perl code "eval "require '$file'"".	It's even implemented that way; consider
	       using load_module instead.

	       NOTE: the perl_ form of this function is deprecated.

		       void    require_pv(const char* pv)

Functions in file dump.c
       pv_display
	       Similar to

		 pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE);

	       except that an additional "\0" will be appended to the string when len > cur and
	       pv[cur] is "\0".

	       Note that the final string may be up to 7 chars longer than pvlim.

		       char*   pv_display(SV *dsv, const char *pv, STRLEN cur,
					  STRLEN len, STRLEN pvlim)

       pv_escape
	       Escapes at most the first "count" chars of pv and puts the results into dsv such
	       that the size of the escaped string will not exceed "max" chars and will not
	       contain any incomplete escape sequences.

	       If flags contains PERL_PV_ESCAPE_QUOTE then any double quotes in the string will
	       also be escaped.

	       Normally the SV will be cleared before the escaped string is prepared, but when
	       PERL_PV_ESCAPE_NOCLEAR is set this will not occur.

	       If PERL_PV_ESCAPE_UNI is set then the input string is treated as Unicode, if
	       PERL_PV_ESCAPE_UNI_DETECT is set then the input string is scanned using
	       "is_utf8_string()" to determine if it is Unicode.

	       If PERL_PV_ESCAPE_ALL is set then all input chars will be output using "\x01F1"
	       style escapes, otherwise if PERL_PV_ESCAPE_NONASCII is set, only chars above 127
	       will be escaped using this style; otherwise, only chars above 255 will be so
	       escaped; other non printable chars will use octal or common escaped patterns like
	       "\n". Otherwise, if PERL_PV_ESCAPE_NOBACKSLASH then all chars below 255 will be
	       treated as printable and will be output as literals.

	       If PERL_PV_ESCAPE_FIRSTCHAR is set then only the first char of the string will be
	       escaped, regardless of max. If the output is to be in hex, then it will be
	       returned as a plain hex sequence. Thus the output will either be a single char, an
	       octal escape sequence, a special escape like "\n" or a hex value.

	       If PERL_PV_ESCAPE_RE is set then the escape char used will be a '%' and not a
	       '\\'. This is because regexes very often contain backslashed sequences, whereas
	       '%' is not a particularly common character in patterns.

	       Returns a pointer to the escaped text as held by dsv.

		       char*   pv_escape(SV *dsv, char const * const str,
					 const STRLEN count, const STRLEN max,
					 STRLEN * const escaped,
					 const U32 flags)

       pv_pretty
	       Converts a string into something presentable, handling escaping via pv_escape()
	       and supporting quoting and ellipses.

	       If the PERL_PV_PRETTY_QUOTE flag is set then the result will be double quoted with
	       any double quotes in the string escaped. Otherwise if the PERL_PV_PRETTY_LTGT flag
	       is set then the result be wrapped in angle brackets.

	       If the PERL_PV_PRETTY_ELLIPSES flag is set and not all characters in string were
	       output then an ellipsis "..." will be appended to the string. Note that this
	       happens AFTER it has been quoted.

	       If start_color is non-null then it will be inserted after the opening quote (if
	       there is one) but before the escaped text. If end_color is non-null then it will
	       be inserted after the escaped text but before any quotes or ellipses.

	       Returns a pointer to the prettified text as held by dsv.

		       char*   pv_pretty(SV *dsv, char const * const str,
					 const STRLEN count, const STRLEN max,
					 char const * const start_color,
					 char const * const end_color,
					 const U32 flags)

Functions in file mathoms.c
       custom_op_desc
	       Return the description of a given custom op. This was once used by the OP_DESC
	       macro, but is no longer: it has only been kept for compatibility, and should not
	       be used.

		       const char * custom_op_desc(const OP *o)

       custom_op_name
	       Return the name for a given custom op. This was once used by the OP_NAME macro,
	       but is no longer: it has only been kept for compatibility, and should not be used.

		       const char * custom_op_name(const OP *o)

       gv_fetchmethod
	       See "gv_fetchmethod_autoload".

		       GV*     gv_fetchmethod(HV* stash, const char* name)

       pack_cat
	       The engine implementing pack() Perl function. Note: parameters next_in_list and
	       flags are not used. This call should not be used; use packlist instead.

		       void    pack_cat(SV *cat, const char *pat,
					const char *patend, SV **beglist,
					SV **endlist, SV ***next_in_list,
					U32 flags)

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

	       Usually accessed via the "SvPVbyte_nolen" macro.

		       char*   sv_2pvbyte_nolen(SV* sv)

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

	       Usually accessed via the "SvPVutf8_nolen" macro.

		       char*   sv_2pvutf8_nolen(SV* sv)

       sv_2pv_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_catpvn_mg
	       Like "sv_catpvn", but also handles 'set' magic.

		       void    sv_catpvn_mg(SV *sv, const char *ptr,
					    STRLEN len)

       sv_catsv_mg
	       Like "sv_catsv", but also handles 'set' magic.

		       void    sv_catsv_mg(SV *dsv, SV *ssv)

       sv_force_normal
	       Undo various types of fakery on an SV: if the PV is a shared string, make a
	       private copy; if we're a ref, stop refing; if we're a glob, downgrade to an xpvmg.
	       See also "sv_force_normal_flags".

		       void    sv_force_normal(SV *sv)

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

		       IV      sv_iv(SV* sv)

       sv_nolocking
	       Dummy routine which "locks" an SV when there is no locking module present.  Exists
	       to avoid test for a NULL function pointer and because it could potentially warn
	       under some level of strict-ness.

	       "Superseded" by sv_nosharing().

		       void    sv_nolocking(SV *sv)

       sv_nounlocking
	       Dummy routine which "unlocks" an SV when there is no locking module present.
	       Exists to avoid test for a NULL function pointer and because it could potentially
	       warn under some level of strict-ness.

	       "Superseded" by sv_nosharing().

		       void    sv_nounlocking(SV *sv)

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

		       NV      sv_nv(SV* sv)

       sv_pv   Use the "SvPV_nolen" macro instead

		       char*   sv_pv(SV *sv)

       sv_pvbyte
	       Use "SvPVbyte_nolen" instead.

		       char*   sv_pvbyte(SV *sv)

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

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

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

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

       sv_pvutf8
	       Use the "SvPVutf8_nolen" macro instead

		       char*   sv_pvutf8(SV *sv)

       sv_pvutf8n
	       A private implementation of the "SvPVutf8" macro for compilers which can't cope
	       with complex macro expressions. Always use the macro instead.

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

       sv_taint
	       Taint an SV. Use "SvTAINTED_on" instead.

		       void    sv_taint(SV* sv)

       sv_unref
	       Unsets the RV status of the SV, and decrements the reference count of whatever was
	       being referenced by the RV.  This can almost be thought of as a reversal of
	       "newSVrv".  This is "sv_unref_flags" with the "flag" being zero.  See "SvROK_off".

		       void    sv_unref(SV* sv)

       sv_usepvn
	       Tells an SV to use "ptr" to find its string value. Implemented by calling
	       "sv_usepvn_flags" with "flags" of 0, hence does not handle 'set' magic. See
	       "sv_usepvn_flags".

		       void    sv_usepvn(SV* sv, char* ptr, STRLEN len)

       sv_usepvn_mg
	       Like "sv_usepvn", but also handles 'set' magic.

		       void    sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)

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

		       UV      sv_uv(SV* sv)

       unpack_str
	       The engine implementing unpack() Perl function. Note: parameters strbeg, new_s and
	       ocnt are not used. This call should not be used, use unpackstring instead.

		       I32     unpack_str(const char *pat, const char *patend,
					  const char *s, const char *strbeg,
					  const char *strend, char **new_s,
					  I32 ocnt, U32 flags)

Functions in file op.c
       op_contextualize
	       Applies a syntactic context to an op tree representing an expression.  o is the op
	       tree, and context must be "G_SCALAR", "G_ARRAY", or "G_VOID" to specify the
	       context to apply.  The modified op tree is returned.

		       OP *    op_contextualize(OP *o, I32 context)

Functions in file perl.h
       PERL_SYS_INIT
	       Provides system-specific tune up of the C runtime environment necessary to run
	       Perl interpreters. This should be called only once, before creating any Perl
	       interpreters.

		       void    PERL_SYS_INIT(int argc, char** argv)

       PERL_SYS_INIT3
	       Provides system-specific tune up of the C runtime environment necessary to run
	       Perl interpreters. This should be called only once, before creating any Perl
	       interpreters.

		       void    PERL_SYS_INIT3(int argc, char** argv,
					      char** env)

       PERL_SYS_TERM
	       Provides system-specific clean up of the C runtime environment after running Perl
	       interpreters. This should be called only once, after freeing any remaining Perl
	       interpreters.

		       void    PERL_SYS_TERM()

Functions in file pp_ctl.c
       caller_cx
	       The XSUB-writer's equivalent of caller(). The returned "PERL_CONTEXT" structure
	       can be interrogated to find all the information returned to Perl by "caller". Note
	       that XSUBs don't get a stack frame, so "caller_cx(0, NULL)" will return
	       information for the immediately-surrounding Perl code.

	       This function skips over the automatic calls to &DB::sub made on the behalf of the
	       debugger. If the stack frame requested was a sub called by "DB::sub", the return
	       value will be the frame for the call to "DB::sub", since that has the correct line
	       number/etc. for the call site. If dbcxp is non-"NULL", it will be set to a pointer
	       to the frame for the sub call itself.

		       const PERL_CONTEXT * caller_cx(
						I32 level,
						const PERL_CONTEXT **dbcxp
					    )

       find_runcv
	       Locate the CV corresponding to the currently executing sub or eval.  If db_seqp is
	       non_null, skip CVs that are in the DB package and populate *db_seqp with the cop
	       sequence number at the point that the DB:: code was entered. (allows debuggers to
	       eval in the scope of the breakpoint rather than in the scope of the debugger
	       itself).

		       CV*     find_runcv(U32 *db_seqp)

Functions in file pp_pack.c
       packlist
	       The engine implementing pack() Perl function.

		       void    packlist(SV *cat, const char *pat,
					const char *patend, SV **beglist,
					SV **endlist)

       unpackstring
	       The engine implementing unpack() Perl function. "unpackstring" puts the extracted
	       list items on the stack and returns the number of elements.  Issue "PUTBACK"
	       before and "SPAGAIN" after the call to this function.

		       I32     unpackstring(const char *pat,
					    const char *patend, const char *s,
					    const char *strend, U32 flags)

Functions in file pp_sys.c
       setdefout
	       Sets PL_defoutgv, the default file handle for output, to the passed in typeglob.
	       As PL_defoutgv "owns" a reference on its typeglob, the reference count of the
	       passed in typeglob is increased by one, and the reference count of the typeglob
	       that PL_defoutgv points to is decreased by one.

		       void    setdefout(GV* gv)

Functions in file utf8.h
       ibcmp_utf8
	       This is a synonym for (! foldEQ_utf8())

		       I32     ibcmp_utf8(const char *s1, char **pe1, UV l1,
					  bool u1, const char *s2, char **pe2,
					  UV l2, bool u2)

Functions in file util.h
       ibcmp   This is a synonym for (! foldEQ())

		       I32     ibcmp(const char* a, const char* b, I32 len)

       ibcmp_locale
	       This is a synonym for (! foldEQ_locale())

		       I32     ibcmp_locale(const char* a, const char* b,
					    I32 len)

Global Variables
       PL_check
	       Array, indexed by opcode, of functions that will be called for the "check" phase
	       of optree building during compilation of Perl code.  For most (but not all) types
	       of op, once the op has been initially built and populated with child ops it will
	       be filtered through the check function referenced by the appropriate element of
	       this array.  The new op is passed in as the sole argument to the check function,
	       and the check function returns the completed op.  The check function may (as the
	       name suggests) check the op for validity and signal errors.  It may also
	       initialise or modify parts of the ops, or perform more radical surgery such as
	       adding or removing child ops, or even throw the op away and return a different op
	       in its place.

	       This array of function pointers is a convenient place to hook into the compilation
	       process.  An XS module can put its own custom check function in place of any of
	       the standard ones, to influence the compilation of a particular type of op.
	       However, a custom check function must never fully replace a standard check
	       function (or even a custom check function from another module).	A module
	       modifying checking must instead wrap the preexisting check function.  A custom
	       check function must be selective about when to apply its custom behaviour.  In the
	       usual case where it decides not to do anything special with an op, it must chain
	       the preexisting op function.  Check functions are thus linked in a chain, with the
	       core's base checker at the end.

	       For thread safety, modules should not write directly to this array.  Instead, use
	       the function "wrap_op_checker".

       PL_keyword_plugin
	       Function pointer, pointing at a function used to handle extended keywords.  The
	       function should be declared as

		       int keyword_plugin_function(pTHX_
			       char *keyword_ptr, STRLEN keyword_len,
			       OP **op_ptr)

	       The function is called from the tokeniser, whenever a possible keyword is seen.
	       "keyword_ptr" points at the word in the parser's input buffer, and "keyword_len"
	       gives its length; it is not null-terminated.  The function is expected to examine
	       the word, and possibly other state such as %^H, to decide whether it wants to
	       handle it as an extended keyword.  If it does not, the function should return
	       "KEYWORD_PLUGIN_DECLINE", and the normal parser process will continue.

	       If the function wants to handle the keyword, it first must parse anything
	       following the keyword that is part of the syntax introduced by the keyword.  See
	       "Lexer interface" for details.

	       When a keyword is being handled, the plugin function must build a tree of "OP"
	       structures, representing the code that was parsed.  The root of the tree must be
	       stored in *op_ptr.  The function then returns a constant indicating the syntactic
	       role of the construct that it has parsed: "KEYWORD_PLUGIN_STMT" if it is a
	       complete statement, or "KEYWORD_PLUGIN_EXPR" if it is an expression.  Note that a
	       statement construct cannot be used inside an expression (except via "do BLOCK" and
	       similar), and an expression is not a complete statement (it requires at least a
	       terminating semicolon).

	       When a keyword is handled, the plugin function may also have (compile-time) side
	       effects.  It may modify "%^H", define functions, and so on.  Typically, if side
	       effects are the main purpose of a handler, it does not wish to generate any ops to
	       be included in the normal compilation.  In this case it is still required to
	       supply an op tree, but it suffices to generate a single null op.

	       That's how the *PL_keyword_plugin function needs to behave overall.
	       Conventionally, however, one does not completely replace the existing handler
	       function.  Instead, take a copy of "PL_keyword_plugin" before assigning your own
	       function pointer to it.	Your handler function should look for keywords that it is
	       interested in and handle those.	Where it is not interested, it should call the
	       saved plugin function, passing on the arguments it received.  Thus
	       "PL_keyword_plugin" actually points at a chain of handler functions, all of which
	       have an opportunity to handle keywords, and only the last function in the chain
	       (built into the Perl core) will normally return "KEYWORD_PLUGIN_DECLINE".

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

GV Functions
       GvSV    Return the SV from the GV.

		       SV*     GvSV(GV* gv)

       gv_const_sv
	       If "gv" is a typeglob whose subroutine entry is a constant sub eligible for
	       inlining, or "gv" is a placeholder reference that would be promoted to such a
	       typeglob, then returns the value returned by the sub.  Otherwise, returns NULL.

		       SV*     gv_const_sv(GV* gv)

       gv_fetchmeth
	       Like "gv_fetchmeth_pvn", but lacks a flags parameter.

		       GV*     gv_fetchmeth(HV* stash, const char* name,
					    STRLEN len, I32 level)

       gv_fetchmethod_autoload
	       Returns the glob which contains the subroutine to call to invoke the method on the
	       "stash".  In fact in the presence of autoloading this may be the glob for
	       "AUTOLOAD".  In this case the corresponding variable $AUTOLOAD is already setup.

	       The third parameter of "gv_fetchmethod_autoload" determines whether AUTOLOAD
	       lookup is performed if the given method is not present: non-zero means yes, look
	       for AUTOLOAD; zero means no, don't look for AUTOLOAD.  Calling "gv_fetchmethod" is
	       equivalent to calling "gv_fetchmethod_autoload" with a non-zero "autoload"
	       parameter.

	       These functions grant "SUPER" token as a prefix of the method name. Note that if
	       you want to keep the returned glob for a long time, you need to check for it being
	       "AUTOLOAD", since at the later time the call may load a different subroutine due
	       to $AUTOLOAD changing its value. Use the glob created via a side effect to do
	       this.

	       These functions have the same side-effects and as "gv_fetchmeth" with "level==0".
	       "name" should be writable if contains ':' or ' ''. The warning against passing the
	       GV returned by "gv_fetchmeth" to "call_sv" apply equally to these functions.

		       GV*     gv_fetchmethod_autoload(HV* stash,
						       const char* name,
						       I32 autoload)

       gv_fetchmeth_autoload
	       This is the old form of "gv_fetchmeth_pvn_autoload", which has no flags parameter.

		       GV*     gv_fetchmeth_autoload(HV* stash,
						     const char* name,
						     STRLEN len, I32 level)

       gv_fetchmeth_pv
	       Exactly like "gv_fetchmeth_pvn", but takes a nul-terminated string instead of a
	       string/length pair.

		       GV*     gv_fetchmeth_pv(HV* stash, const char* name,
					       I32 level, U32 flags)

       gv_fetchmeth_pvn
	       Returns the glob with the given "name" and a defined subroutine or "NULL".  The
	       glob lives in the given "stash", or in the stashes accessible via @ISA and
	       UNIVERSAL::.

	       The argument "level" should be either 0 or -1.  If "level==0", as a side-effect
	       creates a glob with the given "name" in the given "stash" which in the case of
	       success contains an alias for the subroutine, and sets up caching info for this
	       glob.

	       Currently, the only significant value for "flags" is SVf_UTF8.

	       This function grants "SUPER" token as a postfix of the stash name. The GV returned
	       from "gv_fetchmeth" may be a method cache entry, which is not visible to Perl
	       code.  So when calling "call_sv", you should not use the GV directly; instead, you
	       should use the method's CV, which can be obtained from the GV with the "GvCV"
	       macro.

		       GV*     gv_fetchmeth_pvn(HV* stash, const char* name,
						STRLEN len, I32 level,
						U32 flags)

       gv_fetchmeth_pvn_autoload
	       Same as gv_fetchmeth_pvn(), but looks for autoloaded subroutines too.  Returns a
	       glob for the subroutine.

	       For an autoloaded subroutine without a GV, will create a GV even if "level < 0".
	       For an autoloaded subroutine without a stub, GvCV() of the result may be zero.

	       Currently, the only significant value for "flags" is SVf_UTF8.

		       GV*     gv_fetchmeth_pvn_autoload(HV* stash,
							 const char* name,
							 STRLEN len, I32 level,
							 U32 flags)

       gv_fetchmeth_pv_autoload
	       Exactly like "gv_fetchmeth_pvn_autoload", but takes a nul-terminated string
	       instead of a string/length pair.

		       GV*     gv_fetchmeth_pv_autoload(HV* stash,
							const char* name,
							I32 level, U32 flags)

       gv_fetchmeth_sv
	       Exactly like "gv_fetchmeth_pvn", but takes the name string in the form of an SV
	       instead of a string/length pair.

		       GV*     gv_fetchmeth_sv(HV* stash, SV* namesv,
					       I32 level, U32 flags)

       gv_fetchmeth_sv_autoload
	       Exactly like "gv_fetchmeth_pvn_autoload", but takes the name string in the form of
	       an SV instead of a string/length pair.

		       GV*     gv_fetchmeth_sv_autoload(HV* stash, SV* namesv,
							I32 level, U32 flags)

       gv_init The old form of gv_init_pvn().  It does not work with UTF8 strings, as it has no
	       flags parameter.  If the "multi" parameter is set, the GV_ADDMULTI flag will be
	       passed to gv_init_pvn().

		       void    gv_init(GV* gv, HV* stash, const char* name,
				       STRLEN len, int multi)

       gv_init_pv
	       Same as gv_init_pvn(), but takes a nul-terminated string for the name instead of
	       separate char * and length parameters.

		       void    gv_init_pv(GV* gv, HV* stash, const char* name,
					  U32 flags)

       gv_init_pvn
	       Converts a scalar into a typeglob.  This is an incoercible typeglob; assigning a
	       reference to it will assign to one of its slots, instead of overwriting it as
	       happens with typeglobs created by SvSetSV.  Converting any scalar that is SvOK()
	       may produce unpredictable results and is reserved for perl's internal use.

	       "gv" is the scalar to be converted.

	       "stash" is the parent stash/package, if any.

	       "name" and "len" give the name.	The name must be unqualified; that is, it must
	       not include the package name.  If "gv" is a stash element, it is the caller's
	       responsibility to ensure that the name passed to this function matches the name of
	       the element.  If it does not match, perl's internal bookkeeping will get out of
	       sync.

	       "flags" can be set to SVf_UTF8 if "name" is a UTF8 string, or the return value of
	       SvUTF8(sv).  It can also take the GV_ADDMULTI flag, which means to pretend that
	       the GV has been seen before (i.e., suppress "Used once" warnings).

		       void    gv_init_pvn(GV* gv, HV* stash, const char* name,
					   STRLEN len, U32 flags)

       gv_init_sv
	       Same as gv_init_pvn(), but takes an SV * for the name instead of separate char *
	       and length parameters.  "flags" is currently unused.

		       void    gv_init_sv(GV* gv, HV* stash, SV* namesv,
					  U32 flags)

       gv_stashpv
	       Returns a pointer to the stash for a specified package.	Uses "strlen" to
	       determine the length of "name", then calls "gv_stashpvn()".

		       HV*     gv_stashpv(const char* name, I32 flags)

       gv_stashpvn
	       Returns a pointer to the stash for a specified package.	The "namelen" parameter
	       indicates the length of the "name", in bytes.  "flags" is passed to
	       "gv_fetchpvn_flags()", so if set to "GV_ADD" then the package will be created if
	       it does not already exist.  If the package does not exist and "flags" is 0 (or any
	       other setting that does not create packages) then NULL is returned.

		       HV*     gv_stashpvn(const char* name, U32 namelen,
					   I32 flags)

       gv_stashpvs
	       Like "gv_stashpvn", but takes a literal string instead of a string/length pair.

		       HV*     gv_stashpvs(const char* name, I32 create)

       gv_stashsv
	       Returns a pointer to the stash for a specified package.	See "gv_stashpvn".

		       HV*     gv_stashsv(SV* sv, I32 flags)

Handy Values
       Nullav  Null AV pointer.

	       (deprecated - use "(AV *)NULL" instead)

       Nullch  Null character pointer. (No longer available when "PERL_CORE" is defined.)

       Nullcv  Null CV pointer.

	       (deprecated - use "(CV *)NULL" instead)

       Nullhv  Null HV pointer.

	       (deprecated - use "(HV *)NULL" instead)

       Nullsv  Null SV pointer. (No longer available when "PERL_CORE" is defined.)

Hash Manipulation Functions
       cop_fetch_label
	       Returns the label attached to a cop.  The flags pointer may be set to "SVf_UTF8"
	       or 0.

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

		       const char * cop_fetch_label(COP *const cop,
						    STRLEN *len, U32 *flags)

       cop_store_label
	       Save a label into a "cop_hints_hash". You need to set flags to "SVf_UTF8" for a
	       utf-8 label.

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

		       void    cop_store_label(COP *const cop,
					       const char *label, STRLEN len,
					       U32 flags)

       get_hv  Returns the HV of the specified Perl hash.  "flags" are passed to "gv_fetchpv". If
	       "GV_ADD" is set and the Perl variable does not exist then it will be created.  If
	       "flags" is zero and the variable does not exist then NULL is returned.

	       NOTE: the perl_ form of this function is deprecated.

		       HV*     get_hv(const char *name, I32 flags)

       HEf_SVKEY
	       This flag, used in the length slot of hash entries and magic structures, specifies
	       the structure contains an "SV*" pointer where a "char*" pointer is to be expected.
	       (For information only--not to be used).

       HeHASH  Returns the computed hash stored in the hash entry.

		       U32     HeHASH(HE* he)

       HeKEY   Returns the actual pointer stored in the key slot of the hash entry. The pointer
	       may be either "char*" or "SV*", depending on the value of "HeKLEN()".  Can be
	       assigned to.  The "HePV()" or "HeSVKEY()" macros are usually preferable for
	       finding the value of a key.

		       void*   HeKEY(HE* he)

       HeKLEN  If this is negative, and amounts to "HEf_SVKEY", it indicates the entry holds an
	       "SV*" key.  Otherwise, holds the actual length of the key.  Can be assigned to.
	       The "HePV()" macro is usually preferable for finding key lengths.

		       STRLEN  HeKLEN(HE* he)

       HePV    Returns the key slot of the hash entry as a "char*" value, doing any necessary
	       dereferencing of possibly "SV*" keys.  The length of the string is placed in "len"
	       (this is a macro, so do not use &len).  If you do not care about what the length
	       of the key is, you may use the global variable "PL_na", though this is rather less
	       efficient than using a local variable.  Remember though, that hash keys in perl
	       are free to contain embedded nulls, so using "strlen()" or similar is not a good
	       way to find the length of hash keys. This is very similar to the "SvPV()" macro
	       described elsewhere in this document. See also "HeUTF8".

	       If you are using "HePV" to get values to pass to "newSVpvn()" to create a new SV,
	       you should consider using "newSVhek(HeKEY_hek(he))" as it is more efficient.

		       char*   HePV(HE* he, STRLEN len)

       HeSVKEY Returns the key as an "SV*", or "NULL" if the hash entry does not contain an "SV*"
	       key.

		       SV*     HeSVKEY(HE* he)

       HeSVKEY_force
	       Returns the key as an "SV*".  Will create and return a temporary mortal "SV*" if
	       the hash entry contains only a "char*" key.

		       SV*     HeSVKEY_force(HE* he)

       HeSVKEY_set
	       Sets the key to a given "SV*", taking care to set the appropriate flags to
	       indicate the presence of an "SV*" key, and returns the same "SV*".

		       SV*     HeSVKEY_set(HE* he, SV* sv)

       HeUTF8  Returns whether the "char *" value returned by "HePV" is encoded in UTF-8, doing
	       any necessary dereferencing of possibly "SV*" keys.  The value returned will be 0
	       or non-0, not necessarily 1 (or even a value with any low bits set), so do not
	       blindly assign this to a "bool" variable, as "bool" may be a typedef for "char".

		       char*   HeUTF8(HE* he)

       HeVAL   Returns the value slot (type "SV*") stored in the hash entry.

		       SV*     HeVAL(HE* he)

       HvENAME Returns the effective name of a stash, or NULL if there is none. The effective
	       name represents a location in the symbol table where this stash resides. It is
	       updated automatically when packages are aliased or deleted.  A stash that is no
	       longer in the symbol table has no effective name. This name is preferable to
	       "HvNAME" for use in MRO linearisations and isa caches.

		       char*   HvENAME(HV* stash)

       HvENAMELEN
	       Returns the length of the stash's effective name.

		       STRLEN  HvENAMELEN(HV *stash)

       HvENAMEUTF8
	       Returns true if the effective name is in UTF8 encoding.

		       unsigned char HvENAMEUTF8(HV *stash)

       HvNAME  Returns the package name of a stash, or NULL if "stash" isn't a stash.  See
	       "SvSTASH", "CvSTASH".

		       char*   HvNAME(HV* stash)

       HvNAMELEN
	       Returns the length of the stash's name.

		       STRLEN  HvNAMELEN(HV *stash)

       HvNAMEUTF8
	       Returns true if the name is in UTF8 encoding.

		       unsigned char HvNAMEUTF8(HV *stash)

       hv_assert
	       Check that a hash is in an internally consistent state.

		       void    hv_assert(HV *hv)

       hv_clear
	       Frees the all the elements of a hash, leaving it empty.	The XS equivalent of
	       "%hash = ()".  See also "hv_undef".

	       If any destructors are triggered as a result, the hv itself may be freed.

		       void    hv_clear(HV *hv)

       hv_clear_placeholders
	       Clears any placeholders from a hash.  If a restricted hash has any of its keys
	       marked as readonly and the key is subsequently deleted, the key is not actually
	       deleted but is marked by assigning it a value of &PL_sv_placeholder.  This tags it
	       so it will be ignored by future operations such as iterating over the hash, but
	       will still allow the hash to have a value reassigned to the key at some future
	       point.  This function clears any such placeholder keys from the hash.  See
	       Hash::Util::lock_keys() for an example of its use.

		       void    hv_clear_placeholders(HV *hv)

       hv_copy_hints_hv
	       A specialised version of "newHVhv" for copying "%^H".  ohv must be a pointer to a
	       hash (which may have "%^H" magic, but should be generally non-magical), or "NULL"
	       (interpreted as an empty hash).	The content of ohv is copied to a new hash, which
	       has the "%^H"-specific magic added to it.  A pointer to the new hash is returned.

		       HV *    hv_copy_hints_hv(HV *ohv)

       hv_delete
	       Deletes a key/value pair in the hash.  The value's SV is removed from the hash,
	       made mortal, and returned to the caller.  The absolute value of "klen" is the
	       length of the key.  If "klen" is negative the key is assumed to be in
	       UTF-8-encoded Unicode.  The "flags" value will normally be zero; if set to
	       G_DISCARD then NULL will be returned.  NULL will also be returned if the key is
	       not found.

		       SV*     hv_delete(HV *hv, const char *key, I32 klen,
					 I32 flags)

       hv_delete_ent
	       Deletes a key/value pair in the hash.  The value SV is removed from the hash, made
	       mortal, and returned to the caller.  The "flags" value will normally be zero; if
	       set to G_DISCARD then NULL will be returned.  NULL will also be returned if the
	       key is not found.  "hash" can be a valid precomputed hash value, or 0 to ask for
	       it to be computed.

		       SV*     hv_delete_ent(HV *hv, SV *keysv, I32 flags,
					     U32 hash)

       hv_exists
	       Returns a boolean indicating whether the specified hash key exists.  The absolute
	       value of "klen" is the length of the key.  If "klen" is negative the key is
	       assumed to be in UTF-8-encoded Unicode.

		       bool    hv_exists(HV *hv, const char *key, I32 klen)

       hv_exists_ent
	       Returns a boolean indicating whether the specified hash key exists.  "hash" can be
	       a valid precomputed hash value, or 0 to ask for it to be computed.

		       bool    hv_exists_ent(HV *hv, SV *keysv, U32 hash)

       hv_fetch
	       Returns the SV which corresponds to the specified key in the hash.  The absolute
	       value of "klen" is the length of the key.  If "klen" is negative the key is
	       assumed to be in UTF-8-encoded Unicode.	If "lval" is set then the fetch will be
	       part of a store.  Check that the return value is non-null before dereferencing it
	       to an "SV*".

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied hashes.

		       SV**    hv_fetch(HV *hv, const char *key, I32 klen,
					I32 lval)

       hv_fetchs
	       Like "hv_fetch", but takes a literal string instead of a string/length pair.

		       SV**    hv_fetchs(HV* tb, const char* key, I32 lval)

       hv_fetch_ent
	       Returns the hash entry which corresponds to the specified key in the hash.  "hash"
	       must be a valid precomputed hash number for the given "key", or 0 if you want the
	       function to compute it.	IF "lval" is set then the fetch will be part of a store.
	       Make sure the return value is non-null before accessing it.  The return value when
	       "hv" is a tied hash is a pointer to a static location, so be sure to make a copy
	       of the structure if you need to store it somewhere.

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied hashes.

		       HE*     hv_fetch_ent(HV *hv, SV *keysv, I32 lval,
					    U32 hash)

       hv_fill Returns the number of hash buckets that happen to be in use. This function is
	       wrapped by the macro "HvFILL".

	       Previously this value was stored in the HV structure, rather than being calculated
	       on demand.

		       STRLEN  hv_fill(HV const *const hv)

       hv_iterinit
	       Prepares a starting point to traverse a hash table.  Returns the number of keys in
	       the hash (i.e. the same as "HvUSEDKEYS(hv)").  The return value is currently only
	       meaningful for hashes without tie magic.

	       NOTE: Before version 5.004_65, "hv_iterinit" used to return the number of hash
	       buckets that happen to be in use.  If you still need that esoteric value, you can
	       get it through the macro "HvFILL(hv)".

		       I32     hv_iterinit(HV *hv)

       hv_iterkey
	       Returns the key from the current position of the hash iterator.	See
	       "hv_iterinit".

		       char*   hv_iterkey(HE* entry, I32* retlen)

       hv_iterkeysv
	       Returns the key as an "SV*" from the current position of the hash iterator.  The
	       return value will always be a mortal copy of the key.  Also see "hv_iterinit".

		       SV*     hv_iterkeysv(HE* entry)

       hv_iternext
	       Returns entries from a hash iterator.  See "hv_iterinit".

	       You may call "hv_delete" or "hv_delete_ent" on the hash entry that the iterator
	       currently points to, without losing your place or invalidating your iterator.
	       Note that in this case the current entry is deleted from the hash with your
	       iterator holding the last reference to it.  Your iterator is flagged to free the
	       entry on the next call to "hv_iternext", so you must not discard your iterator
	       immediately else the entry will leak - call "hv_iternext" to trigger the resource
	       deallocation.

		       HE*     hv_iternext(HV *hv)

       hv_iternextsv
	       Performs an "hv_iternext", "hv_iterkey", and "hv_iterval" in one operation.

		       SV*     hv_iternextsv(HV *hv, char **key, I32 *retlen)

       hv_iternext_flags
	       Returns entries from a hash iterator.  See "hv_iterinit" and "hv_iternext".  The
	       "flags" value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is set the
	       placeholders keys (for restricted hashes) will be returned in addition to normal
	       keys. By default placeholders are automatically skipped over.  Currently a
	       placeholder is implemented with a value that is &PL_sv_placeholder.  Note that the
	       implementation of placeholders and restricted hashes may change, and the
	       implementation currently is insufficiently abstracted for any change to be tidy.

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

		       HE*     hv_iternext_flags(HV *hv, I32 flags)

       hv_iterval
	       Returns the value from the current position of the hash iterator.  See
	       "hv_iterkey".

		       SV*     hv_iterval(HV *hv, HE *entry)

       hv_magic
	       Adds magic to a hash.  See "sv_magic".

		       void    hv_magic(HV *hv, GV *gv, int how)

       hv_scalar
	       Evaluates the hash in scalar context and returns the result. Handles magic when
	       the hash is tied.

		       SV*     hv_scalar(HV *hv)

       hv_store
	       Stores an SV in a hash.	The hash key is specified as "key" and the absolute value
	       of "klen" is the length of the key.  If "klen" is negative the key is assumed to
	       be in UTF-8-encoded Unicode.  The "hash" parameter is the precomputed hash value;
	       if it is zero then Perl will compute it.

	       The return value will be NULL if the operation failed or if the value did not need
	       to be actually stored within the hash (as in the case of tied hashes).  Otherwise
	       it can be dereferenced to get the original "SV*".  Note that the caller is
	       responsible for suitably incrementing the reference count of "val" before the
	       call, and decrementing it if the function returned NULL.  Effectively a successful
	       hv_store takes ownership of one reference to "val".  This is usually what you
	       want; a newly created SV has a reference count of one, so if all your code does is
	       create SVs then store them in a hash, hv_store will own the only reference to the
	       new SV, and your code doesn't need to do anything further to tidy up.  hv_store is
	       not implemented as a call to hv_store_ent, and does not create a temporary SV for
	       the key, so if your key data is not already in SV form then use hv_store in
	       preference to hv_store_ent.

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied hashes.

		       SV**    hv_store(HV *hv, const char *key, I32 klen,
					SV *val, U32 hash)

       hv_stores
	       Like "hv_store", but takes a literal string instead of a string/length pair and
	       omits the hash parameter.

		       SV**    hv_stores(HV* tb, const char* key,
					 NULLOK SV* val)

       hv_store_ent
	       Stores "val" in a hash.	The hash key is specified as "key".  The "hash" parameter
	       is the precomputed hash value; if it is zero then Perl will compute it.	The
	       return value is the new hash entry so created.  It will be NULL if the operation
	       failed or if the value did not need to be actually stored within the hash (as in
	       the case of tied hashes).  Otherwise the contents of the return value can be
	       accessed using the "He?" macros described here.	Note that the caller is
	       responsible for suitably incrementing the reference count of "val" before the
	       call, and decrementing it if the function returned NULL.  Effectively a successful
	       hv_store_ent takes ownership of one reference to "val".	This is usually what you
	       want; a newly created SV has a reference count of one, so if all your code does is
	       create SVs then store them in a hash, hv_store will own the only reference to the
	       new SV, and your code doesn't need to do anything further to tidy up.  Note that
	       hv_store_ent only reads the "key"; unlike "val" it does not take ownership of it,
	       so maintaining the correct reference count on "key" is entirely the caller's
	       responsibility.	hv_store is not implemented as a call to hv_store_ent, and does
	       not create a temporary SV for the key, so if your key data is not already in SV
	       form then use hv_store in preference to hv_store_ent.

	       See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
	       information on how to use this function on tied hashes.

		       HE*     hv_store_ent(HV *hv, SV *key, SV *val, U32 hash)

       hv_undef
	       Undefines the hash.  The XS equivalent of "undef(%hash)".

	       As well as freeing all the elements of the hash (like hv_clear()), this also frees
	       any auxiliary data and storage associated with the hash.

	       If any destructors are triggered as a result, the hv itself may be freed.

	       See also "hv_clear".

		       void    hv_undef(HV *hv)

       newHV   Creates a new HV.  The reference count is set to 1.

		       HV*     newHV()

Hook manipulation
       wrap_op_checker
	       Puts a C function into the chain of check functions for a specified op type.  This
	       is the preferred way to manipulate the "PL_check" array.  opcode specifies which
	       type of op is to be affected.  new_checker is a pointer to the C function that is
	       to be added to that opcode's check chain, and old_checker_p points to the storage
	       location where a pointer to the next function in the chain will be stored.  The
	       value of new_pointer is written into the "PL_check" array, while the value
	       previously stored there is written to *old_checker_p.

	       "PL_check" is global to an entire process, and a module wishing to hook op
	       checking may find itself invoked more than once per process, typically in
	       different threads.  To handle that situation, this function is idempotent.  The
	       location *old_checker_p must initially (once per process) contain a null pointer.
	       A C variable of static duration (declared at file scope, typically also marked
	       "static" to give it internal linkage) will be implicitly initialised
	       appropriately, if it does not have an explicit initialiser.  This function will
	       only actually modify the check chain if it finds *old_checker_p to be null.  This
	       function is also thread safe on the small scale.  It uses appropriate locking to
	       avoid race conditions in accessing "PL_check".

	       When this function is called, the function referenced by new_checker must be ready
	       to be called, except for *old_checker_p being unfilled.	In a threading situation,
	       new_checker may be called immediately, even before this function has returned.
	       *old_checker_p will always be appropriately set before new_checker is called.  If
	       new_checker decides not to do anything special with an op that it is given (which
	       is the usual case for most uses of op check hooking), it must chain the check
	       function referenced by *old_checker_p.

	       If you want to influence compilation of calls to a specific subroutine, then use
	       "cv_set_call_checker" rather than hooking checking of all "entersub" ops.

		       void    wrap_op_checker(Optype opcode,
					       Perl_check_t new_checker,
					       Perl_check_t *old_checker_p)

Lexer interface
       lex_bufutf8
	       Indicates whether the octets in the lexer buffer ("PL_parser->linestr") should be
	       interpreted as the UTF-8 encoding of Unicode characters.  If not, they should be
	       interpreted as Latin-1 characters.  This is analogous to the "SvUTF8" flag for
	       scalars.

	       In UTF-8 mode, it is not guaranteed that the lexer buffer actually contains valid
	       UTF-8.  Lexing code must be robust in the face of invalid encoding.

	       The actual "SvUTF8" flag of the "PL_parser->linestr" scalar is significant, but
	       not the whole story regarding the input character encoding.  Normally, when a file
	       is being read, the scalar contains octets and its "SvUTF8" flag is off, but the
	       octets should be interpreted as UTF-8 if the "use utf8" pragma is in effect.
	       During a string eval, however, the scalar may have the "SvUTF8" flag on, and in
	       this case its octets should be interpreted as UTF-8 unless the "use bytes" pragma
	       is in effect.  This logic may change in the future; use this function instead of
	       implementing the logic yourself.

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

		       bool    lex_bufutf8()

       lex_discard_to
	       Discards the first part of the "PL_parser->linestr" buffer, up to ptr.  The
	       remaining content of the buffer will be moved, and all pointers into the buffer
	       updated appropriately.  ptr must not be later in the buffer than the position of
	       "PL_parser->bufptr": it is not permitted to discard text that has yet to be lexed.

	       Normally it is not necessarily to do this directly, because it suffices to use the
	       implicit discarding behaviour of "lex_next_chunk" and things based on it.
	       However, if a token stretches across multiple lines, and the lexing code has kept
	       multiple lines of text in the buffer for that purpose, then after completion of
	       the token it would be wise to explicitly discard the now-unneeded earlier lines,
	       to avoid future multi-line tokens growing the buffer without bound.

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

		       void    lex_discard_to(char *ptr)

       lex_grow_linestr
	       Reallocates the lexer buffer ("PL_parser->linestr") to accommodate at least len
	       octets (including terminating NUL).  Returns a pointer to the reallocated buffer.
	       This is necessary before making any direct modification of the buffer that would
	       increase its length.  "lex_stuff_pvn" provides a more convenient way to insert
	       text into the buffer.

	       Do not use "SvGROW" or "sv_grow" directly on "PL_parser->linestr"; this function
	       updates all of the lexer's variables that point directly into the buffer.

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

		       char *  lex_grow_linestr(STRLEN len)

       lex_next_chunk
	       Reads in the next chunk of text to be lexed, appending it to "PL_parser->linestr".
	       This should be called when lexing code has looked to the end of the current chunk
	       and wants to know more.	It is usual, but not necessary, for lexing to have
	       consumed the entirety of the current chunk at this time.

	       If "PL_parser->bufptr" is pointing to the very end of the current chunk (i.e., the
	       current chunk has been entirely consumed), normally the current chunk will be
	       discarded at the same time that the new chunk is read in.  If flags includes
	       "LEX_KEEP_PREVIOUS", the current chunk will not be discarded.  If the current
	       chunk has not been entirely consumed, then it will not be discarded regardless of
	       the flag.

	       Returns true if some new text was added to the buffer, or false if the buffer has
	       reached the end of the input text.

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

		       bool    lex_next_chunk(U32 flags)

       lex_peek_unichar
	       Looks ahead one (Unicode) character in the text currently being lexed.  Returns
	       the codepoint (unsigned integer value) of the next character, or -1 if lexing has
	       reached the end of the input text.  To consume the peeked character, use
	       "lex_read_unichar".

	       If the next character is in (or extends into) the next chunk of input text, the
	       next chunk will be read in.  Normally the current chunk will be discarded at the
	       same time, but if flags includes "LEX_KEEP_PREVIOUS" then the current chunk will
	       not be discarded.

	       If the input is being interpreted as UTF-8 and a UTF-8 encoding error is
	       encountered, an exception is generated.

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

		       I32     lex_peek_unichar(U32 flags)

       lex_read_space
	       Reads optional spaces, in Perl style, in the text currently being lexed.  The
	       spaces may include ordinary whitespace characters and Perl-style comments.
	       "#line" directives are processed if encountered.  "PL_parser->bufptr" is moved
	       past the spaces, so that it points at a non-space character (or the end of the
	       input text).

	       If spaces extend into the next chunk of input text, the next chunk will be read
	       in.  Normally the current chunk will be discarded at the same time, but if flags
	       includes "LEX_KEEP_PREVIOUS" then the current chunk will not be discarded.

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

		       void    lex_read_space(U32 flags)

       lex_read_to
	       Consume text in the lexer buffer, from "PL_parser->bufptr" up to ptr.  This
	       advances "PL_parser->bufptr" to match ptr, performing the correct bookkeeping
	       whenever a newline character is passed.	This is the normal way to consume lexed
	       text.

	       Interpretation of the buffer's octets can be abstracted out by using the slightly
	       higher-level functions "lex_peek_unichar" and "lex_read_unichar".

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

		       void    lex_read_to(char *ptr)

       lex_read_unichar
	       Reads the next (Unicode) character in the text currently being lexed.  Returns the
	       codepoint (unsigned integer value) of the character read, and moves
	       "PL_parser->bufptr" past the character, or returns -1 if lexing has reached the
	       end of the input text.  To non-destructively examine the next character, use
	       "lex_peek_unichar" instead.

	       If the next character is in (or extends into) the next chunk of input text, the
	       next chunk will be read in.  Normally the current chunk will be discarded at the
	       same time, but if flags includes "LEX_KEEP_PREVIOUS" then the current chunk will
	       not be discarded.

	       If the input is being interpreted as UTF-8 and a UTF-8 encoding error is
	       encountered, an exception is generated.

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

		       I32     lex_read_unichar(U32 flags)

       lex_start
	       Creates and initialises a new lexer/parser state object, supplying a context in
	       which to lex and parse from a new source of Perl code.  A pointer to the new state
	       object is placed in "PL_parser".  An entry is made on the save stack so that upon
	       unwinding the new state object will be destroyed and the former value of
	       "PL_parser" will be restored.  Nothing else need be done to clean up the parsing
	       context.

	       The code to be parsed comes from line and rsfp.	line, if non-null, provides a
	       string (in SV form) containing code to be parsed.  A copy of the string is made,
	       so subsequent modification of line does not affect parsing.  rsfp, if non-null,
	       provides an input stream from which code will be read to be parsed.  If both are
	       non-null, the code in line comes first and must consist of complete lines of
	       input, and rsfp supplies the remainder of the source.

	       The flags parameter is reserved for future use.	Currently it is only used by perl
	       internally, so extensions should always pass zero.

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

		       void    lex_start(SV *line, PerlIO *rsfp, U32 flags)

       lex_stuff_pv
	       Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after
	       the current lexing point ("PL_parser->bufptr"), reallocating the buffer if
	       necessary.  This means that lexing code that runs later will see the characters as
	       if they had appeared in the input.  It is not recommended to do this as part of
	       normal parsing, and most uses of this facility run the risk of the inserted
	       characters being interpreted in an unintended manner.

	       The string to be inserted is represented by octets starting at pv and continuing
	       to the first nul.  These octets are interpreted as either UTF-8 or Latin-1,
	       according to whether the "LEX_STUFF_UTF8" flag is set in flags.	The characters
	       are recoded for the lexer buffer, according to how the buffer is currently being
	       interpreted ("lex_bufutf8").  If it is not convenient to nul-terminate a string to
	       be inserted, the "lex_stuff_pvn" function is more appropriate.

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

		       void    lex_stuff_pv(const char *pv, U32 flags)

       lex_stuff_pvn
	       Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after
	       the current lexing point ("PL_parser->bufptr"), reallocating the buffer if
	       necessary.  This means that lexing code that runs later will see the characters as
	       if they had appeared in the input.  It is not recommended to do this as part of
	       normal parsing, and most uses of this facility run the risk of the inserted
	       characters being interpreted in an unintended manner.

	       The string to be inserted is represented by len octets starting at pv.  These
	       octets are interpreted as either UTF-8 or Latin-1, according to whether the
	       "LEX_STUFF_UTF8" flag is set in flags.  The characters are recoded for the lexer
	       buffer, according to how the buffer is currently being interpreted
	       ("lex_bufutf8").  If a string to be inserted is available as a Perl scalar, the
	       "lex_stuff_sv" function is more convenient.

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

		       void    lex_stuff_pvn(const char *pv, STRLEN len,
					     U32 flags)

       lex_stuff_pvs
	       Like "lex_stuff_pvn", but takes a literal string instead of a string/length pair.

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

		       void    lex_stuff_pvs(const char *pv, U32 flags)

       lex_stuff_sv
	       Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after
	       the current lexing point ("PL_parser->bufptr"), reallocating the buffer if
	       necessary.  This means that lexing code that runs later will see the characters as
	       if they had appeared in the input.  It is not recommended to do this as part of
	       normal parsing, and most uses of this facility run the risk of the inserted
	       characters being interpreted in an unintended manner.

	       The string to be inserted is the string value of sv.  The characters are recoded
	       for the lexer buffer, according to how the buffer is currently being interpreted
	       ("lex_bufutf8").  If a string to be inserted is not already a Perl scalar, the
	       "lex_stuff_pvn" function avoids the need to construct a scalar.

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

		       void    lex_stuff_sv(SV *sv, U32 flags)

       lex_unstuff
	       Discards text about to be lexed, from "PL_parser->bufptr" up to ptr.  Text
	       following ptr will be moved, and the buffer shortened.  This hides the discarded
	       text from any lexing code that runs later, as if the text had never appeared.

	       This is not the normal way to consume lexed text.  For that, use "lex_read_to".

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

		       void    lex_unstuff(char *ptr)

       parse_arithexpr
	       Parse a Perl arithmetic expression.  This may contain operators of precedence down
	       to the bit shift operators.  The expression must be followed (and thus terminated)
	       either by a comparison or lower-precedence operator or by something that would
	       normally terminate an expression such as semicolon.  If flags includes
	       "PARSE_OPTIONAL" then the expression is optional, otherwise it is mandatory.  It
	       is up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
	       correctly set to reflect the source of the code to be parsed and the lexical
	       context for the expression.

	       The op tree representing the expression is returned.  If an optional expression is
	       absent, a null pointer is returned, otherwise the pointer will be non-null.

	       If an error occurs in parsing or compilation, in most cases a valid op tree is
	       returned anyway.  The error is reflected in the parser state, normally resulting
	       in a single exception at the top level of parsing which covers all the compilation
	       errors that occurred.  Some compilation errors, however, will throw an exception
	       immediately.

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

		       OP *    parse_arithexpr(U32 flags)

       parse_barestmt
	       Parse a single unadorned Perl statement.  This may be a normal imperative
	       statement or a declaration that has compile-time effect.  It does not include any
	       label or other affixture.  It is up to the caller to ensure that the dynamic
	       parser state ("PL_parser" et al) is correctly set to reflect the source of the
	       code to be parsed and the lexical context for the statement.

	       The op tree representing the statement is returned.  This may be a null pointer if
	       the statement is null, for example if it was actually a subroutine definition
	       (which has compile-time side effects).  If not null, it will be ops directly
	       implementing the statement, suitable to pass to "newSTATEOP".  It will not
	       normally include a "nextstate" or equivalent op (except for those embedded in a
	       scope contained entirely within the statement).

	       If an error occurs in parsing or compilation, in most cases a valid op tree (most
	       likely null) is returned anyway.  The error is reflected in the parser state,
	       normally resulting in a single exception at the top level of parsing which covers
	       all the compilation errors that occurred.  Some compilation errors, however, will
	       throw an exception immediately.

	       The flags parameter is reserved for future use, and must always be zero.

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

		       OP *    parse_barestmt(U32 flags)

       parse_block
	       Parse a single complete Perl code block.  This consists of an opening brace, a
	       sequence of statements, and a closing brace.  The block constitutes a lexical
	       scope, so "my" variables and various compile-time effects can be contained within
	       it.  It is up to the caller to ensure that the dynamic parser state ("PL_parser"
	       et al) is correctly set to reflect the source of the code to be parsed and the
	       lexical context for the statement.

	       The op tree representing the code block is returned.  This is always a real op,
	       never a null pointer.  It will normally be a "lineseq" list, including "nextstate"
	       or equivalent ops.  No ops to construct any kind of runtime scope are included by
	       virtue of it being a block.

	       If an error occurs in parsing or compilation, in most cases a valid op tree (most
	       likely null) is returned anyway.  The error is reflected in the parser state,
	       normally resulting in a single exception at the top level of parsing which covers
	       all the compilation errors that occurred.  Some compilation errors, however, will
	       throw an exception immediately.

	       The flags parameter is reserved for future use, and must always be zero.

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

		       OP *    parse_block(U32 flags)

       parse_fullexpr
	       Parse a single complete Perl expression.  This allows the full expression grammar,
	       including the lowest-precedence operators such as "or".	The expression must be
	       followed (and thus terminated) by a token that an expression would normally be
	       terminated by: end-of-file, closing bracketing punctuation, semicolon, or one of
	       the keywords that signals a postfix expression-statement modifier.  If flags
	       includes "PARSE_OPTIONAL" then the expression is optional, otherwise it is
	       mandatory.  It is up to the caller to ensure that the dynamic parser state
	       ("PL_parser" et al) is correctly set to reflect the source of the code to be
	       parsed and the lexical context for the expression.

	       The op tree representing the expression is returned.  If an optional expression is
	       absent, a null pointer is returned, otherwise the pointer will be non-null.

	       If an error occurs in parsing or compilation, in most cases a valid op tree is
	       returned anyway.  The error is reflected in the parser state, normally resulting
	       in a single exception at the top level of parsing which covers all the compilation
	       errors that occurred.  Some compilation errors, however, will throw an exception
	       immediately.

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

		       OP *    parse_fullexpr(U32 flags)

       parse_fullstmt
	       Parse a single complete Perl statement.	This may be a normal imperative statement
	       or a declaration that has compile-time effect, and may include optional labels.
	       It is up to the caller to ensure that the dynamic parser state ("PL_parser" et al)
	       is correctly set to reflect the source of the code to be parsed and the lexical
	       context for the statement.

	       The op tree representing the statement is returned.  This may be a null pointer if
	       the statement is null, for example if it was actually a subroutine definition
	       (which has compile-time side effects).  If not null, it will be the result of a
	       "newSTATEOP" call, normally including a "nextstate" or equivalent op.

	       If an error occurs in parsing or compilation, in most cases a valid op tree (most
	       likely null) is returned anyway.  The error is reflected in the parser state,
	       normally resulting in a single exception at the top level of parsing which covers
	       all the compilation errors that occurred.  Some compilation errors, however, will
	       throw an exception immediately.

	       The flags parameter is reserved for future use, and must always be zero.

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

		       OP *    parse_fullstmt(U32 flags)

       parse_label
	       Parse a single label, possibly optional, of the type that may prefix a Perl
	       statement.  It is up to the caller to ensure that the dynamic parser state
	       ("PL_parser" et al) is correctly set to reflect the source of the code to be
	       parsed.	If flags includes "PARSE_OPTIONAL" then the label is optional, otherwise
	       it is mandatory.

	       The name of the label is returned in the form of a fresh scalar.  If an optional
	       label is absent, a null pointer is returned.

	       If an error occurs in parsing, which can only occur if the label is mandatory, a
	       valid label is returned anyway.	The error is reflected in the parser state,
	       normally resulting in a single exception at the top level of parsing which covers
	       all the compilation errors that occurred.

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

		       SV *    parse_label(U32 flags)

       parse_listexpr
	       Parse a Perl list expression.  This may contain operators of precedence down to
	       the comma operator.  The expression must be followed (and thus terminated) either
	       by a low-precedence logic operator such as "or" or by something that would
	       normally terminate an expression such as semicolon.  If flags includes
	       "PARSE_OPTIONAL" then the expression is optional, otherwise it is mandatory.  It
	       is up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
	       correctly set to reflect the source of the code to be parsed and the lexical
	       context for the expression.

	       The op tree representing the expression is returned.  If an optional expression is
	       absent, a null pointer is returned, otherwise the pointer will be non-null.

	       If an error occurs in parsing or compilation, in most cases a valid op tree is
	       returned anyway.  The error is reflected in the parser state, normally resulting
	       in a single exception at the top level of parsing which covers all the compilation
	       errors that occurred.  Some compilation errors, however, will throw an exception
	       immediately.

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

		       OP *    parse_listexpr(U32 flags)

       parse_stmtseq
	       Parse a sequence of zero or more Perl statements.  These may be normal imperative
	       statements, including optional labels, or declarations that have compile-time
	       effect, or any mixture thereof.	The statement sequence ends when a closing brace
	       or end-of-file is encountered in a place where a new statement could have validly
	       started.  It is up to the caller to ensure that the dynamic parser state
	       ("PL_parser" et al) is correctly set to reflect the source of the code to be
	       parsed and the lexical context for the statements.

	       The op tree representing the statement sequence is returned.  This may be a null
	       pointer if the statements were all null, for example if there were no statements
	       or if there were only subroutine definitions (which have compile-time side
	       effects).  If not null, it will be a "lineseq" list, normally including
	       "nextstate" or equivalent ops.

	       If an error occurs in parsing or compilation, in most cases a valid op tree is
	       returned anyway.  The error is reflected in the parser state, normally resulting
	       in a single exception at the top level of parsing which covers all the compilation
	       errors that occurred.  Some compilation errors, however, will throw an exception
	       immediately.

	       The flags parameter is reserved for future use, and must always be zero.

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

		       OP *    parse_stmtseq(U32 flags)

       parse_termexpr
	       Parse a Perl term expression.  This may contain operators of precedence down to
	       the assignment operators.  The expression must be followed (and thus terminated)
	       either by a comma or lower-precedence operator or by something that would normally
	       terminate an expression such as semicolon.  If flags includes "PARSE_OPTIONAL"
	       then the expression is optional, otherwise it is mandatory.  It is up to the
	       caller to ensure that the dynamic parser state ("PL_parser" et al) is correctly
	       set to reflect the source of the code to be parsed and the lexical context for the
	       expression.

	       The op tree representing the expression is returned.  If an optional expression is
	       absent, a null pointer is returned, otherwise the pointer will be non-null.

	       If an error occurs in parsing or compilation, in most cases a valid op tree is
	       returned anyway.  The error is reflected in the parser state, normally resulting
	       in a single exception at the top level of parsing which covers all the compilation
	       errors that occurred.  Some compilation errors, however, will throw an exception
	       immediately.

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

		       OP *    parse_termexpr(U32 flags)

       PL_parser
	       Pointer to a structure encapsulating the state of the parsing operation currently
	       in progress.  The pointer can be locally changed to perform a nested parse without
	       interfering with the state of an outer parse.  Individual members of "PL_parser"
	       have their own documentation.

       PL_parser->bufend
	       Direct pointer to the end of the chunk of text currently being lexed, the end of
	       the lexer buffer.  This is equal to "SvPVX(PL_parser->linestr) +
	       SvCUR(PL_parser->linestr)".  A NUL character (zero octet) is always located at the
	       end of the buffer, and does not count as part of the buffer's contents.

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

       PL_parser->bufptr
	       Points to the current position of lexing inside the lexer buffer.  Characters
	       around this point may be freely examined, within the range delimited by
	       "SvPVX("PL_parser->linestr")" and "PL_parser->bufend".  The octets of the buffer
	       may be intended to be interpreted as either UTF-8 or Latin-1, as indicated by
	       "lex_bufutf8".

	       Lexing code (whether in the Perl core or not) moves this pointer past the
	       characters that it consumes.  It is also expected to perform some bookkeeping
	       whenever a newline character is consumed.  This movement can be more conveniently
	       performed by the function "lex_read_to", which handles newlines appropriately.

	       Interpretation of the buffer's octets can be abstracted out by using the slightly
	       higher-level functions "lex_peek_unichar" and "lex_read_unichar".

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

       PL_parser->linestart
	       Points to the start of the current line inside the lexer buffer.  This is useful
	       for indicating at which column an error occurred, and not much else.  This must be
	       updated by any lexing code that consumes a newline; the function "lex_read_to"
	       handles this detail.

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

       PL_parser->linestr
	       Buffer scalar containing the chunk currently under consideration of the text
	       currently being lexed.  This is always a plain string scalar (for which "SvPOK" is
	       true).  It is not intended to be used as a scalar by normal scalar means; instead
	       refer to the buffer directly by the pointer variables described below.

	       The lexer maintains various "char*" pointers to things in the "PL_parser->linestr"
	       buffer.	If "PL_parser->linestr" is ever reallocated, all of these pointers must
	       be updated.  Don't attempt to do this manually, but rather use "lex_grow_linestr"
	       if you need to reallocate the buffer.

	       The content of the text chunk in the buffer is commonly exactly one complete line
	       of input, up to and including a newline terminator, but there are situations where
	       it is otherwise.  The octets of the buffer may be intended to be interpreted as
	       either UTF-8 or Latin-1.  The function "lex_bufutf8" tells you which.  Do not use
	       the "SvUTF8" flag on this scalar, which may disagree with it.

	       For direct examination of the buffer, the variable "PL_parser->bufend" points to
	       the end of the buffer.  The current lexing position is pointed to by
	       "PL_parser->bufptr".  Direct use of these pointers is usually preferable to
	       examination of the scalar through normal scalar means.

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

Magical Functions
       mg_clear
	       Clear something magical that the SV represents.	See "sv_magic".

		       int     mg_clear(SV* sv)

       mg_copy Copies the magic from one SV to another.  See "sv_magic".

		       int     mg_copy(SV *sv, SV *nsv, const char *key,
				       I32 klen)

       mg_find Finds the magic pointer for type matching the SV.  See "sv_magic".

		       MAGIC*  mg_find(const SV* sv, int type)

       mg_findext
	       Finds the magic pointer of "type" with the given "vtbl" for the "SV".  See
	       "sv_magicext".

		       MAGIC*  mg_findext(const SV* sv, int type,
					  const MGVTBL *vtbl)

       mg_free Free any magic storage used by the SV.  See "sv_magic".

		       int     mg_free(SV* sv)

       mg_free_type
	       Remove any magic of type how from the SV sv.  See "sv_magic".

		       void    mg_free_type(SV *sv, int how)

       mg_get  Do magic before a value is retrieved from the SV.  See "sv_magic".

		       int     mg_get(SV* sv)

       mg_length
	       Report on the SV's length.  See "sv_magic".

		       U32     mg_length(SV* sv)

       mg_magical
	       Turns on the magical status of an SV.  See "sv_magic".

		       void    mg_magical(SV* sv)

       mg_set  Do magic after a value is assigned to the SV.  See "sv_magic".

		       int     mg_set(SV* sv)

       SvGETMAGIC
	       Invokes "mg_get" on an SV if it has 'get' magic.  This macro evaluates its
	       argument more than once.

		       void    SvGETMAGIC(SV* sv)

       SvLOCK  Arranges for a mutual exclusion lock to be obtained on sv if a suitable module has
	       been loaded.

		       void    SvLOCK(SV* sv)

       SvSETMAGIC
	       Invokes "mg_set" on an SV if it has 'set' magic.  This macro evaluates its
	       argument more than once.

		       void    SvSETMAGIC(SV* sv)

       SvSetMagicSV
	       Like "SvSetSV", but does any set magic required afterwards.

		       void    SvSetMagicSV(SV* dsb, SV* ssv)

       SvSetMagicSV_nosteal
	       Like "SvSetSV_nosteal", but does any set magic required afterwards.

		       void    SvSetMagicSV_nosteal(SV* dsv, SV* ssv)

       SvSetSV Calls "sv_setsv" if dsv is not the same as ssv.	May evaluate arguments more than
	       once.

		       void    SvSetSV(SV* dsb, SV* ssv)

       SvSetSV_nosteal
	       Calls a non-destructive version of "sv_setsv" if dsv is not the same as ssv.  May
	       evaluate arguments more than once.

		       void    SvSetSV_nosteal(SV* dsv, SV* ssv)

       SvSHARE Arranges for sv to be shared between threads if a suitable module has been loaded.

		       void    SvSHARE(SV* sv)

       SvUNLOCK
	       Releases a mutual exclusion lock on sv if a suitable module has been loaded.

		       void    SvUNLOCK(SV* sv)

Memory Management
       Copy    The XSUB-writer's interface to the C "memcpy" function.	The "src" is the source,
	       "dest" is the destination, "nitems" is the number of items, and "type" is the
	       type.  May fail on overlapping copies.  See also "Move".

		       void    Copy(void* src, void* dest, int nitems, type)

       CopyD   Like "Copy" but returns dest. Useful for encouraging compilers to tail-call
	       optimise.

		       void *  CopyD(void* src, void* dest, int nitems, type)

       Move    The XSUB-writer's interface to the C "memmove" function.  The "src" is the source,
	       "dest" is the destination, "nitems" is the number of items, and "type" is the
	       type.  Can do overlapping moves.  See also "Copy".

		       void    Move(void* src, void* dest, int nitems, type)

       MoveD   Like "Move" but returns dest. Useful for encouraging compilers to tail-call
	       optimise.

		       void *  MoveD(void* src, void* dest, int nitems, type)

       Newx    The XSUB-writer's interface to the C "malloc" function.

	       In 5.9.3, Newx() and friends replace the older New() API, and drops the first
	       parameter, x, a debug aid which allowed callers to identify themselves.	This aid
	       has been superseded by a new build option, PERL_MEM_LOG (see "PERL_MEM_LOG" in
	       perlhacktips).  The older API is still there for use in XS modules supporting
	       older perls.

		       void    Newx(void* ptr, int nitems, type)

       Newxc   The XSUB-writer's interface to the C "malloc" function, with cast.  See also
	       "Newx".

		       void    Newxc(void* ptr, int nitems, type, cast)

       Newxz   The XSUB-writer's interface to the C "malloc" function.	The allocated memory is
	       zeroed with "memzero".  See also "Newx".

		       void    Newxz(void* ptr, int nitems, type)

       Poison  PoisonWith(0xEF) for catching access to freed memory.

		       void    Poison(void* dest, int nitems, type)

       PoisonFree
	       PoisonWith(0xEF) for catching access to freed memory.

		       void    PoisonFree(void* dest, int nitems, type)

       PoisonNew
	       PoisonWith(0xAB) for catching access to allocated but uninitialized memory.

		       void    PoisonNew(void* dest, int nitems, type)

       PoisonWith
	       Fill up memory with a byte pattern (a byte repeated over and over again) that
	       hopefully catches attempts to access uninitialized memory.

		       void    PoisonWith(void* dest, int nitems, type,
					  U8 byte)

       Renew   The XSUB-writer's interface to the C "realloc" function.

		       void    Renew(void* ptr, int nitems, type)

       Renewc  The XSUB-writer's interface to the C "realloc" function, with cast.

		       void    Renewc(void* ptr, int nitems, type, cast)

       Safefree
	       The XSUB-writer's interface to the C "free" function.

		       void    Safefree(void* ptr)

       savepv  Perl's version of "strdup()". Returns a pointer to a newly allocated string which
	       is a duplicate of "pv". The size of the string is determined by "strlen()". The
	       memory allocated for the new string can be freed with the "Safefree()" function.

		       char*   savepv(const char* pv)

       savepvn Perl's version of what "strndup()" would be if it existed. Returns a pointer to a
	       newly allocated string which is a duplicate of the first "len" bytes from "pv",
	       plus a trailing NUL byte. The memory allocated for the new string can be freed
	       with the "Safefree()" function.

		       char*   savepvn(const char* pv, I32 len)

       savepvs Like "savepvn", but takes a literal string instead of a string/length pair.

		       char*   savepvs(const char* s)

       savesharedpv
	       A version of "savepv()" which allocates the duplicate string in memory which is
	       shared between threads.

		       char*   savesharedpv(const char* pv)

       savesharedpvn
	       A version of "savepvn()" which allocates the duplicate string in memory which is
	       shared between threads. (With the specific difference that a NULL pointer is not
	       acceptable)

		       char*   savesharedpvn(const char *const pv,
					     const STRLEN len)

       savesharedpvs
	       A version of "savepvs()" which allocates the duplicate string in memory which is
	       shared between threads.

		       char*   savesharedpvs(const char* s)

       savesharedsvpv
	       A version of "savesharedpv()" which allocates the duplicate string in memory which
	       is shared between threads.

		       char*   savesharedsvpv(SV *sv)

       savesvpv
	       A version of "savepv()"/"savepvn()" which gets the string to duplicate from the
	       passed in SV using "SvPV()"

		       char*   savesvpv(SV* sv)

       StructCopy
	       This is an architecture-independent macro to copy one structure to another.

		       void    StructCopy(type src, type dest, type)

       Zero    The XSUB-writer's interface to the C "memzero" function.  The "dest" is the
	       destination, "nitems" is the number of items, and "type" is the type.

		       void    Zero(void* dest, int nitems, type)

       ZeroD   Like "Zero" but returns dest. Useful for encouraging compilers to tail-call
	       optimise.

		       void *  ZeroD(void* dest, int nitems, type)

Miscellaneous Functions
       fbm_compile
	       Analyses the string in order to make fast searches on it using fbm_instr() -- the
	       Boyer-Moore algorithm.

		       void    fbm_compile(SV* sv, U32 flags)

       fbm_instr
	       Returns the location of the SV in the string delimited by "str" and "strend".  It
	       returns "NULL" if the string can't be found.  The "sv" does not have to be
	       fbm_compiled, but the search will not be as fast then.

		       char*   fbm_instr(unsigned char* big,
					 unsigned char* bigend, SV* littlestr,
					 U32 flags)

       foldEQ  Returns true if the leading len bytes of the strings s1 and s2 are the same case-
	       insensitively; false otherwise.	Uppercase and lowercase ASCII range bytes match
	       themselves and their opposite case counterparts.  Non-cased and non-ASCII range
	       bytes match only themselves.

		       I32     foldEQ(const char* a, const char* b, I32 len)

       foldEQ_locale
	       Returns true if the leading len bytes of the strings s1 and s2 are the same case-
	       insensitively in the current locale; false otherwise.

		       I32     foldEQ_locale(const char* a, const char* b,
					     I32 len)

       form    Takes a sprintf-style format pattern and conventional (non-SV) arguments and
	       returns the formatted string.

		   (char *) Perl_form(pTHX_ const char* pat, ...)

	       can be used any place a string (char *) is required:

		   char * s = Perl_form("%d.%d",major,minor);

	       Uses a single private buffer so if you want to format several strings you must
	       explicitly copy the earlier strings away (and free the copies when you are done).

		       char*   form(const char* pat, ...)

       getcwd_sv
	       Fill the sv with current working directory

		       int     getcwd_sv(SV* sv)

       mess    Take a sprintf-style format pattern and argument list.  These are used to generate
	       a string message.  If the message does not end with a newline, then it will be
	       extended with some indication of the current location in the code, as described
	       for "mess_sv".

	       Normally, the resulting message is returned in a new mortal SV.	During global
	       destruction a single SV may be shared between uses of this function.

		       SV *    mess(const char *pat, ...)

       mess_sv Expands a message, intended for the user, to include an indication of the current
	       location in the code, if the message does not already appear to be complete.

	       "basemsg" is the initial message or object.  If it is a reference, it will be used
	       as-is and will be the result of this function.  Otherwise it is used as a string,
	       and if it already ends with a newline, it is taken to be complete, and the result
	       of this function will be the same string.  If the message does not end with a
	       newline, then a segment such as "at foo.pl line 37" will be appended, and possibly
	       other clauses indicating the current state of execution.  The resulting message
	       will end with a dot and a newline.

	       Normally, the resulting message is returned in a new mortal SV.	During global
	       destruction a single SV may be shared between uses of this function.  If "consume"
	       is true, then the function is permitted (but not required) to modify and return
	       "basemsg" instead of allocating a new SV.

		       SV *    mess_sv(SV *basemsg, bool consume)

       my_snprintf
	       The C library "snprintf" functionality, if available and standards-compliant (uses
	       "vsnprintf", actually).	However, if the "vsnprintf" is not available, will
	       unfortunately use the unsafe "vsprintf" which can overrun the buffer (there is an
	       overrun check, but that may be too late).  Consider using "sv_vcatpvf" instead, or
	       getting "vsnprintf".

		       int     my_snprintf(char *buffer, const Size_t len,
					   const char *format, ...)

       my_sprintf
	       The C library "sprintf", wrapped if necessary, to ensure that it will return the
	       length of the string written to the buffer. Only rare pre-ANSI systems need the
	       wrapper function - usually this is a direct call to "sprintf".

		       int     my_sprintf(char *buffer, const char *pat, ...)

       my_vsnprintf
	       The C library "vsnprintf" if available and standards-compliant.	However, if if
	       the "vsnprintf" is not available, will unfortunately use the unsafe "vsprintf"
	       which can overrun the buffer (there is an overrun check, but that may be too
	       late).  Consider using "sv_vcatpvf" instead, or getting "vsnprintf".

		       int     my_vsnprintf(char *buffer, const Size_t len,
					    const char *format, va_list ap)

       new_version
	       Returns a new version object based on the passed in SV:

		   SV *sv = new_version(SV *ver);

	       Does not alter the passed in ver SV.  See "upg_version" if you want to upgrade the
	       SV.

		       SV*     new_version(SV *ver)

       prescan_version
	       Validate that a given string can be parsed as a version object, but doesn't
	       actually perform the parsing.  Can use either strict or lax validation rules.  Can
	       optionally set a number of hint variables to save the parsing code some time when
	       tokenizing.

		       const char* prescan_version(const char *s, bool strict,
						   const char** errstr,
						   bool *sqv,
						   int *ssaw_decimal,
						   int *swidth, bool *salpha)

       scan_version
	       Returns a pointer to the next character after the parsed version string, as well
	       as upgrading the passed in SV to an RV.

	       Function must be called with an already existing SV like

		   sv = newSV(0);
		   s = scan_version(s, SV *sv, bool qv);

	       Performs some preprocessing to the string to ensure that it has the correct
	       characteristics of a version.  Flags the object if it contains an underscore
	       (which denotes this is an alpha version).  The boolean qv denotes that the version
	       should be interpreted as if it had multiple decimals, even if it doesn't.

		       const char* scan_version(const char *s, SV *rv, bool qv)

       strEQ   Test two strings to see if they are equal.  Returns true or false.

		       bool    strEQ(char* s1, char* s2)

       strGE   Test two strings to see if the first, "s1", is greater than or equal to the
	       second, "s2".  Returns true or false.

		       bool    strGE(char* s1, char* s2)

       strGT   Test two strings to see if the first, "s1", is greater than the second, "s2".
	       Returns true or false.

		       bool    strGT(char* s1, char* s2)

       strLE   Test two strings to see if the first, "s1", is less than or equal to the second,
	       "s2".  Returns true or false.

		       bool    strLE(char* s1, char* s2)

       strLT   Test two strings to see if the first, "s1", is less than the second, "s2".
	       Returns true or false.

		       bool    strLT(char* s1, char* s2)

       strNE   Test two strings to see if they are different.  Returns true or false.

		       bool    strNE(char* s1, char* s2)

       strnEQ  Test two strings to see if they are equal.  The "len" parameter indicates the
	       number of bytes to compare.  Returns true or false. (A wrapper for "strncmp").

		       bool    strnEQ(char* s1, char* s2, STRLEN len)

       strnNE  Test two strings to see if they are different.  The "len" parameter indicates the
	       number of bytes to compare.  Returns true or false. (A wrapper for "strncmp").

		       bool    strnNE(char* s1, char* s2, STRLEN len)

       sv_destroyable
	       Dummy routine which reports that object can be destroyed when there is no sharing
	       module present.	It ignores its single SV argument, and returns 'true'.	Exists to
	       avoid test for a NULL function pointer and because it could potentially warn under
	       some level of strict-ness.

		       bool    sv_destroyable(SV *sv)

       sv_nosharing
	       Dummy routine which "shares" an SV when there is no sharing module present.  Or
	       "locks" it. Or "unlocks" it. In other words, ignores its single SV argument.
	       Exists to avoid test for a NULL function pointer and because it could potentially
	       warn under some level of strict-ness.

		       void    sv_nosharing(SV *sv)

       upg_version
	       In-place upgrade of the supplied SV to a version object.

		   SV *sv = upg_version(SV *sv, bool qv);

	       Returns a pointer to the upgraded SV.  Set the boolean qv if you want to force
	       this SV to be interpreted as an "extended" version.

		       SV*     upg_version(SV *ver, bool qv)

       vcmp    Version object aware cmp.  Both operands must already have been converted into
	       version objects.

		       int     vcmp(SV *lhv, SV *rhv)

       vmess   "pat" and "args" are a sprintf-style format pattern and encapsulated argument
	       list.  These are used to generate a string message.  If the message does not end
	       with a newline, then it will be extended with some indication of the current
	       location in the code, as described for "mess_sv".

	       Normally, the resulting message is returned in a new mortal SV.	During global
	       destruction a single SV may be shared between uses of this function.

		       SV *    vmess(const char *pat, va_list *args)

       vnormal Accepts a version object and returns the normalized string representation.  Call
	       like:

		   sv = vnormal(rv);

	       NOTE: you can pass either the object directly or the SV contained within the RV.

	       The SV returned has a refcount of 1.

		       SV*     vnormal(SV *vs)

       vnumify Accepts a version object and returns the normalized floating point representation.
	       Call like:

		   sv = vnumify(rv);

	       NOTE: you can pass either the object directly or the SV contained within the RV.

	       The SV returned has a refcount of 1.

		       SV*     vnumify(SV *vs)

       vstringify
	       In order to maintain maximum compatibility with earlier versions of Perl, this
	       function will return either the floating point notation or the multiple dotted
	       notation, depending on whether the original version contained 1 or more dots,
	       respectively.

	       The SV returned has a refcount of 1.

		       SV*     vstringify(SV *vs)

       vverify Validates that the SV contains valid internal structure for a version object.  It
	       may be passed either the version object (RV) or the hash itself (HV).  If the
	       structure is valid, it returns the HV.  If the structure is invalid, it returns
	       NULL.

		   SV *hv = vverify(sv);

	       Note that it only confirms the bare minimum structure (so as not to get confused
	       by derived classes which may contain additional hash entries):

		       SV*     vverify(SV *vs)

MRO Functions
       mro_get_linear_isa
	       Returns the mro linearisation for the given stash.  By default, this will be
	       whatever "mro_get_linear_isa_dfs" returns unless some other MRO is in effect for
	       the stash.  The return value is a read-only AV*.

	       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(HV* stash)

       mro_method_changed_in
	       Invalidates method caching on any child classes of the given stash, so that they
	       might notice the changes in this one.

	       Ideally, all instances of "PL_sub_generation++" in perl source outside of mro.c
	       should be replaced by calls to this.

	       Perl automatically handles most of the common ways a method might be redefined.
	       However, there are a few ways you could change a method in a stash without the
	       cache code noticing, in which case you need to call this method afterwards:

	       1) Directly manipulating the stash HV entries from XS code.

	       2) Assigning a reference to a readonly scalar constant into a stash entry in order
	       to create a constant subroutine (like constant.pm does).

	       This same method is available from pure perl via,
	       "mro::method_changed_in(classname)".

		       void    mro_method_changed_in(HV* stash)

       mro_register
	       Registers a custom mro plugin.  See perlmroapi for details.

		       void    mro_register(const struct mro_alg *mro)

Multicall Functions
       dMULTICALL
	       Declare local variables for a multicall. See "LIGHTWEIGHT CALLBACKS" in perlcall.

			       dMULTICALL;

       MULTICALL
	       Make a lightweight callback. See "LIGHTWEIGHT CALLBACKS" in perlcall.

			       MULTICALL;

       POP_MULTICALL
	       Closing bracket for a lightweight callback.  See "LIGHTWEIGHT CALLBACKS" in
	       perlcall.

			       POP_MULTICALL;

       PUSH_MULTICALL
	       Opening bracket for a lightweight callback.  See "LIGHTWEIGHT CALLBACKS" in
	       perlcall.

			       PUSH_MULTICALL;

Numeric functions
       grok_bin
	       converts a string representing a binary number to numeric form.

	       On entry start and *len give the string to scan, *flags gives conversion flags,
	       and result should be NULL or a pointer to an NV.  The scan stops at the end of the
	       string, or the first invalid character.	Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
	       in *flags, encountering an invalid character will also trigger a warning.  On
	       return *len is set to the length of the scanned string, and *flags gives output
	       flags.

	       If the value is <= "UV_MAX" it is returned as a UV, the output flags are clear,
	       and nothing is written to *result. If the value is > UV_MAX "grok_bin" returns
	       UV_MAX, sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes the
	       value to *result (or the value is discarded if result is NULL).

	       The binary number may optionally be prefixed with "0b" or "b" unless
	       "PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry. If
	       "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the binary number may use '_'
	       characters to separate digits.

		       UV      grok_bin(const char* start, STRLEN* len_p,
					I32* flags, NV *result)

       grok_hex
	       converts a string representing a hex number to numeric form.

	       On entry start and *len give the string to scan, *flags gives conversion flags,
	       and result should be NULL or a pointer to an NV.  The scan stops at the end of the
	       string, or the first invalid character.	Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
	       in *flags, encountering an invalid character will also trigger a warning.  On
	       return *len is set to the length of the scanned string, and *flags gives output
	       flags.

	       If the value is <= UV_MAX it is returned as a UV, the output flags are clear, and
	       nothing is written to *result. If the value is > UV_MAX "grok_hex" returns UV_MAX,
	       sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes the value to
	       *result (or the value is discarded if result is NULL).

	       The hex number may optionally be prefixed with "0x" or "x" unless
	       "PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry. If
	       "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the hex number may use '_'
	       characters to separate digits.

		       UV      grok_hex(const char* start, STRLEN* len_p,
					I32* flags, NV *result)

       grok_number
	       Recognise (or not) a number.  The type of the number is returned (0 if
	       unrecognised), otherwise it is a bit-ORed combination of IS_NUMBER_IN_UV,
	       IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT, IS_NUMBER_NEG,
	       IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).

	       If the value of the number can fit an in UV, it is returned in the *valuep
	       IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV
	       will never be set unless *valuep is valid, but *valuep may have been assigned to
	       during processing even though IS_NUMBER_IN_UV is not set on return.  If valuep is
	       NULL, IS_NUMBER_IN_UV will be set for the same cases as when valuep is non-NULL,
	       but no actual assignment (or SEGV) will occur.

	       IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were seen
	       (in which case *valuep gives the true value truncated to an integer), and
	       IS_NUMBER_NEG if the number is negative (in which case *valuep holds the absolute
	       value).	IS_NUMBER_IN_UV is not set if e notation was used or the number is larger
	       than a UV.

		       int     grok_number(const char *pv, STRLEN len,
					   UV *valuep)

       grok_numeric_radix
	       Scan and skip for a numeric decimal separator (radix).

		       bool    grok_numeric_radix(const char **sp,
						  const char *send)

       grok_oct
	       converts a string representing an octal number to numeric form.

	       On entry start and *len give the string to scan, *flags gives conversion flags,
	       and result should be NULL or a pointer to an NV.  The scan stops at the end of the
	       string, or the first invalid character.	Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
	       in *flags, encountering an 8 or 9 will also trigger a warning.  On return *len is
	       set to the length of the scanned string, and *flags gives output flags.

	       If the value is <= UV_MAX it is returned as a UV, the output flags are clear, and
	       nothing is written to *result. If the value is > UV_MAX "grok_oct" returns UV_MAX,
	       sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes the value to
	       *result (or the value is discarded if result is NULL).

	       If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the octal number may use
	       '_' characters to separate digits.

		       UV      grok_oct(const char* start, STRLEN* len_p,
					I32* flags, NV *result)

       Perl_signbit
	       Return a non-zero integer if the sign bit on an NV is set, and 0 if it is not.

	       If Configure detects this system has a signbit() that will work with our NVs, then
	       we just use it via the #define in perl.h.  Otherwise, fall back on this
	       implementation.	As a first pass, this gets everything right except -0.0.  Alas,
	       catching -0.0 is the main use for this function, so this is not too helpful yet.
	       Still, at least we have the scaffolding in place to support other systems, should
	       that prove useful.

	       Configure notes:  This function is called 'Perl_signbit' instead of a plain
	       'signbit' because it is easy to imagine a system having a signbit() function or
	       macro that doesn't happen to work with our particular choice of NVs.  We shouldn't
	       just re-#define signbit as Perl_signbit and expect the standard system headers to
	       be happy.  Also, this is a no-context function (no pTHX_) because Perl_signbit()
	       is usually re-#defined in perl.h as a simple macro call to the system's signbit().
	       Users should just always call Perl_signbit().

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

		       int     Perl_signbit(NV f)

       scan_bin
	       For backwards compatibility. Use "grok_bin" instead.

		       NV      scan_bin(const char* start, STRLEN len,
					STRLEN* retlen)

       scan_hex
	       For backwards compatibility. Use "grok_hex" instead.

		       NV      scan_hex(const char* start, STRLEN len,
					STRLEN* retlen)

       scan_oct
	       For backwards compatibility. Use "grok_oct" instead.

		       NV      scan_oct(const char* start, STRLEN len,
					STRLEN* retlen)

Optree construction
       newASSIGNOP
	       Constructs, checks, and returns an assignment op.  left and right supply the
	       parameters of the assignment; they are consumed by this function and become part
	       of the constructed op tree.

	       If optype is "OP_ANDASSIGN", "OP_ORASSIGN", or "OP_DORASSIGN", then a suitable
	       conditional optree is constructed.  If optype is the opcode of a binary operator,
	       such as "OP_BIT_OR", then an op is constructed that performs the binary operation
	       and assigns the result to the left argument.  Either way, if optype is non-zero
	       then flags has no effect.

	       If optype is zero, then a plain scalar or list assignment is constructed.  Which
	       type of assignment it is is automatically determined.  flags gives the eight bits
	       of "op_flags", except that "OPf_KIDS" will be set automatically, and, shifted up
	       eight bits, the eight bits of "op_private", except that the bit with value 1 or 2
	       is automatically set as required.

		       OP *    newASSIGNOP(I32 flags, OP *left, I32 optype,
					   OP *right)

       newBINOP
	       Constructs, checks, and returns an op of any binary type.  type is the opcode.
	       flags gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
	       automatically, and, shifted up eight bits, the eight bits of "op_private", except
	       that the bit with value 1 or 2 is automatically set as required.  first and last
	       supply up to two ops to be the direct children of the binary op; they are consumed
	       by this function and become part of the constructed op tree.

		       OP *    newBINOP(I32 type, I32 flags, OP *first,
					OP *last)

       newCONDOP
	       Constructs, checks, and returns a conditional-expression ("cond_expr") op.  flags
	       gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
	       automatically, and, shifted up eight bits, the eight bits of "op_private", except
	       that the bit with value 1 is automatically set.	first supplies the expression
	       selecting between the two branches, and trueop and falseop supply the branches;
	       they are consumed by this function and become part of the constructed op tree.

		       OP *    newCONDOP(I32 flags, OP *first, OP *trueop,
					 OP *falseop)

       newFOROP
	       Constructs, checks, and returns an op tree expressing a "foreach" loop (iteration
	       through a list of values).  This is a heavyweight loop, with structure that allows
	       exiting the loop by "last" and suchlike.

	       sv optionally supplies the variable that will be aliased to each item in turn; if
	       null, it defaults to $_ (either lexical or global).  expr supplies the list of
	       values to iterate over.	block supplies the main body of the loop, and cont
	       optionally supplies a "continue" block that operates as a second half of the body.
	       All of these optree inputs are consumed by this function and become part of the
	       constructed op tree.

	       flags gives the eight bits of "op_flags" for the "leaveloop" op and, shifted up
	       eight bits, the eight bits of "op_private" for the "leaveloop" op, except that (in
	       both cases) some bits will be set automatically.

		       OP *    newFOROP(I32 flags, OP *sv, OP *expr, OP *block,
					OP *cont)

       newGIVENOP
	       Constructs, checks, and returns an op tree expressing a "given" block.  cond
	       supplies the expression that will be locally assigned to a lexical variable, and
	       block supplies the body of the "given" construct; they are consumed by this
	       function and become part of the constructed op tree.  defsv_off is the pad offset
	       of the scalar lexical variable that will be affected.

		       OP *    newGIVENOP(OP *cond, OP *block,
					  PADOFFSET defsv_off)

       newGVOP Constructs, checks, and returns an op of any type that involves an embedded
	       reference to a GV.  type is the opcode.	flags gives the eight bits of "op_flags".
	       gv identifies the GV that the op should reference; calling this function does not
	       transfer ownership of any reference to it.

		       OP *    newGVOP(I32 type, I32 flags, GV *gv)

       newLISTOP
	       Constructs, checks, and returns an op of any list type.	type is the opcode.
	       flags gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
	       automatically if required.  first and last supply up to two ops to be direct
	       children of the list op; they are consumed by this function and become part of the
	       constructed op tree.

		       OP *    newLISTOP(I32 type, I32 flags, OP *first,
					 OP *last)

       newLOGOP
	       Constructs, checks, and returns a logical (flow control) op.  type is the opcode.
	       flags gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
	       automatically, and, shifted up eight bits, the eight bits of "op_private", except
	       that the bit with value 1 is automatically set.	first supplies the expression
	       controlling the flow, and other supplies the side (alternate) chain of ops; they
	       are consumed by this function and become part of the constructed op tree.

		       OP *    newLOGOP(I32 type, I32 flags, OP *first,
					OP *other)

       newLOOPEX
	       Constructs, checks, and returns a loop-exiting op (such as "goto" or "last").
	       type is the opcode.  label supplies the parameter determining the target of the
	       op; it is consumed by this function and become part of the constructed op tree.

		       OP *    newLOOPEX(I32 type, OP *label)

       newLOOPOP
	       Constructs, checks, and returns an op tree expressing a loop.  This is only a loop
	       in the control flow through the op tree; it does not have the heavyweight loop
	       structure that allows exiting the loop by "last" and suchlike.  flags gives the
	       eight bits of "op_flags" for the top-level op, except that some bits will be set
	       automatically as required.  expr supplies the expression controlling loop
	       iteration, and block supplies the body of the loop; they are consumed by this
	       function and become part of the constructed op tree.  debuggable is currently
	       unused and should always be 1.

		       OP *    newLOOPOP(I32 flags, I32 debuggable, OP *expr,
					 OP *block)

       newNULLLIST
	       Constructs, checks, and returns a new "stub" op, which represents an empty list
	       expression.

		       OP *    newNULLLIST()

       newOP   Constructs, checks, and returns an op of any base type (any type that has no extra
	       fields).  type is the opcode.  flags gives the eight bits of "op_flags", and,
	       shifted up eight bits, the eight bits of "op_private".

		       OP *    newOP(I32 type, I32 flags)

       newPADOP
	       Constructs, checks, and returns an op of any type that involves a reference to a
	       pad element.  type is the opcode.  flags gives the eight bits of "op_flags".  A
	       pad slot is automatically allocated, and is populated with sv; this function takes
	       ownership of one reference to it.

	       This function only exists if Perl has been compiled to use ithreads.

		       OP *    newPADOP(I32 type, I32 flags, SV *sv)

       newPMOP Constructs, checks, and returns an op of any pattern matching type.  type is the
	       opcode.	flags gives the eight bits of "op_flags" and, shifted up eight bits, the
	       eight bits of "op_private".

		       OP *    newPMOP(I32 type, I32 flags)

       newPVOP Constructs, checks, and returns an op of any type that involves an embedded
	       C-level pointer (PV).  type is the opcode.  flags gives the eight bits of
	       "op_flags".  pv supplies the C-level pointer, which must have been allocated using
	       "PerlMemShared_malloc"; the memory will be freed when the op is destroyed.

		       OP *    newPVOP(I32 type, I32 flags, char *pv)

       newRANGE
	       Constructs and returns a "range" op, with subordinate "flip" and "flop" ops.
	       flags gives the eight bits of "op_flags" for the "flip" op and, shifted up eight
	       bits, the eight bits of "op_private" for both the "flip" and "range" ops, except
	       that the bit with value 1 is automatically set.	left and right supply the
	       expressions controlling the endpoints of the range; they are consumed by this
	       function and become part of the constructed op tree.

		       OP *    newRANGE(I32 flags, OP *left, OP *right)

       newSLICEOP
	       Constructs, checks, and returns an "lslice" (list slice) op.  flags gives the
	       eight bits of "op_flags", except that "OPf_KIDS" will be set automatically, and,
	       shifted up eight bits, the eight bits of "op_private", except that the bit with
	       value 1 or 2 is automatically set as required.  listval and subscript supply the
	       parameters of the slice; they are consumed by this function and become part of the
	       constructed op tree.

		       OP *    newSLICEOP(I32 flags, OP *subscript,
					  OP *listval)

       newSTATEOP
	       Constructs a state op (COP).  The state op is normally a "nextstate" op, but will
	       be a "dbstate" op if debugging is enabled for currently-compiled code.  The state
	       op is populated from "PL_curcop" (or "PL_compiling").  If label is non-null, it
	       supplies the name of a label to attach to the state op; this function takes
	       ownership of the memory pointed at by label, and will free it.  flags gives the
	       eight bits of "op_flags" for the state op.

	       If o is null, the state op is returned.	Otherwise the state op is combined with o
	       into a "lineseq" list op, which is returned.  o is consumed by this function and
	       becomes part of the returned op tree.

		       OP *    newSTATEOP(I32 flags, char *label, OP *o)

       newSVOP Constructs, checks, and returns an op of any type that involves an embedded SV.
	       type is the opcode.  flags gives the eight bits of "op_flags".  sv gives the SV to
	       embed in the op; this function takes ownership of one reference to it.

		       OP *    newSVOP(I32 type, I32 flags, SV *sv)

       newUNOP Constructs, checks, and returns an op of any unary type.  type is the opcode.
	       flags gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
	       automatically if required, and, shifted up eight bits, the eight bits of
	       "op_private", except that the bit with value 1 is automatically set.  first
	       supplies an optional op to be the direct child of the unary op; it is consumed by
	       this function and become part of the constructed op tree.

		       OP *    newUNOP(I32 type, I32 flags, OP *first)

       newWHENOP
	       Constructs, checks, and returns an op tree expressing a "when" block.  cond
	       supplies the test expression, and block supplies the block that will be executed
	       if the test evaluates to true; they are consumed by this function and become part
	       of the constructed op tree.  cond will be interpreted DWIMically, often as a
	       comparison against $_, and may be null to generate a "default" block.

		       OP *    newWHENOP(OP *cond, OP *block)

       newWHILEOP
	       Constructs, checks, and returns an op tree expressing a "while" loop.  This is a
	       heavyweight loop, with structure that allows exiting the loop by "last" and
	       suchlike.

	       loop is an optional preconstructed "enterloop" op to use in the loop; if it is
	       null then a suitable op will be constructed automatically.  expr supplies the
	       loop's controlling expression.  block supplies the main body of the loop, and cont
	       optionally supplies a "continue" block that operates as a second half of the body.
	       All of these optree inputs are consumed by this function and become part of the
	       constructed op tree.

	       flags gives the eight bits of "op_flags" for the "leaveloop" op and, shifted up
	       eight bits, the eight bits of "op_private" for the "leaveloop" op, except that (in
	       both cases) some bits will be set automatically.  debuggable is currently unused
	       and should always be 1.	has_my can be supplied as true to force the loop body to
	       be enclosed in its own scope.

		       OP *    newWHILEOP(I32 flags, I32 debuggable,
					  LOOP *loop, OP *expr, OP *block,
					  OP *cont, I32 has_my)

Optree Manipulation Functions
       ck_entersub_args_list
	       Performs the default fixup of the arguments part of an "entersub" op tree.  This
	       consists of applying list context to each of the argument ops.  This is the
	       standard treatment used on a call marked with "&", or a method call, or a call
	       through a subroutine reference, or any other call where the callee can't be
	       identified at compile time, or a call where the callee has no prototype.

		       OP *    ck_entersub_args_list(OP *entersubop)

       ck_entersub_args_proto
	       Performs the fixup of the arguments part of an "entersub" op tree based on a
	       subroutine prototype.  This makes various modifications to the argument ops, from
	       applying context up to inserting "refgen" ops, and checking the number and
	       syntactic types of arguments, as directed by the prototype.  This is the standard
	       treatment used on a subroutine call, not marked with "&", where the callee can be
	       identified at compile time and has a prototype.

	       protosv supplies the subroutine prototype to be applied to the call.  It may be a
	       normal defined scalar, of which the string value will be used.  Alternatively, for
	       convenience, it may be a subroutine object (a "CV*" that has been cast to "SV*")
	       which has a prototype.  The prototype supplied, in whichever form, does not need
	       to match the actual callee referenced by the op tree.

	       If the argument ops disagree with the prototype, for example by having an
	       unacceptable number of arguments, a valid op tree is returned anyway.  The error
	       is reflected in the parser state, normally resulting in a single exception at the
	       top level of parsing which covers all the compilation errors that occurred.  In
	       the error message, the callee is referred to by the name defined by the namegv
	       parameter.

		       OP *    ck_entersub_args_proto(OP *entersubop,
						      GV *namegv, SV *protosv)

       ck_entersub_args_proto_or_list
	       Performs the fixup of the arguments part of an "entersub" op tree either based on
	       a subroutine prototype or using default list-context processing.  This is the
	       standard treatment used on a subroutine call, not marked with "&", where the
	       callee can be identified at compile time.

	       protosv supplies the subroutine prototype to be applied to the call, or indicates
	       that there is no prototype.  It may be a normal scalar, in which case if it is
	       defined then the string value will be used as a prototype, and if it is undefined
	       then there is no prototype.  Alternatively, for convenience, it may be a
	       subroutine object (a "CV*" that has been cast to "SV*"), of which the prototype
	       will be used if it has one.  The prototype (or lack thereof) supplied, in
	       whichever form, does not need to match the actual callee referenced by the op
	       tree.

	       If the argument ops disagree with the prototype, for example by having an
	       unacceptable number of arguments, a valid op tree is returned anyway.  The error
	       is reflected in the parser state, normally resulting in a single exception at the
	       top level of parsing which covers all the compilation errors that occurred.  In
	       the error message, the callee is referred to by the name defined by the namegv
	       parameter.

		       OP *    ck_entersub_args_proto_or_list(OP *entersubop,
							      GV *namegv,
							      SV *protosv)

       cv_const_sv
	       If "cv" is a constant sub eligible for inlining. returns the constant value
	       returned by the sub.  Otherwise, returns NULL.

	       Constant subs can be created with "newCONSTSUB" or as described in "Constant
	       Functions" in perlsub.

		       SV*     cv_const_sv(const CV *const cv)

       cv_get_call_checker
	       Retrieves the function that will be used to fix up a call to cv.  Specifically,
	       the function is applied to an "entersub" op tree for a subroutine call, not marked
	       with "&", where the callee can be identified at compile time as cv.

	       The C-level function pointer is returned in *ckfun_p, and an SV argument for it is
	       returned in *ckobj_p.  The function is intended to be called in this manner:

		   entersubop = (*ckfun_p)(aTHX_ entersubop, namegv, (*ckobj_p));

	       In this call, entersubop is a pointer to the "entersub" op, which may be replaced
	       by the check function, and namegv is a GV supplying the name that should be used
	       by the check function to refer to the callee of the "entersub" op if it needs to
	       emit any diagnostics.  It is permitted to apply the check function in non-standard
	       situations, such as to a call to a different subroutine or to a method call.

	       By default, the function is Perl_ck_entersub_args_proto_or_list, and the SV
	       parameter is cv itself.	This implements standard prototype processing.	It can be
	       changed, for a particular subroutine, by "cv_set_call_checker".

		       void    cv_get_call_checker(CV *cv,
						   Perl_call_checker *ckfun_p,
						   SV **ckobj_p)

       cv_set_call_checker
	       Sets the function that will be used to fix up a call to cv.  Specifically, the
	       function is applied to an "entersub" op tree for a subroutine call, not marked
	       with "&", where the callee can be identified at compile time as cv.

	       The C-level function pointer is supplied in ckfun, and an SV argument for it is
	       supplied in ckobj.  The function is intended to be called in this manner:

		   entersubop = ckfun(aTHX_ entersubop, namegv, ckobj);

	       In this call, entersubop is a pointer to the "entersub" op, which may be replaced
	       by the check function, and namegv is a GV supplying the name that should be used
	       by the check function to refer to the callee of the "entersub" op if it needs to
	       emit any diagnostics.  It is permitted to apply the check function in non-standard
	       situations, such as to a call to a different subroutine or to a method call.

	       The current setting for a particular CV can be retrieved by "cv_get_call_checker".

		       void    cv_set_call_checker(CV *cv,
						   Perl_call_checker ckfun,
						   SV *ckobj)

       LINKLIST
	       Given the root of an optree, link the tree in execution order using the "op_next"
	       pointers and return the first op executed. If this has already been done, it will
	       not be redone, and "o->op_next" will be returned. If "o->op_next" is not already
	       set, o should be at least an "UNOP".

		       OP*     LINKLIST(OP *o)

       newCONSTSUB
	       See "newCONSTSUB_flags".

		       CV*     newCONSTSUB(HV* stash, const char* name, SV* sv)

       newCONSTSUB_flags
	       Creates a constant sub equivalent to Perl "sub FOO () { 123 }" which is eligible
	       for inlining at compile-time.

	       Currently, the only useful value for "flags" is SVf_UTF8.

	       Passing NULL for SV creates a constant sub equivalent to "sub BAR () {}", which
	       won't be called if used as a destructor, but will suppress the overhead of a call
	       to "AUTOLOAD".  (This form, however, isn't eligible for inlining at compile time.)

		       CV*     newCONSTSUB_flags(HV* stash, const char* name,
						 STRLEN len, U32 flags, SV* sv)

       newXS   Used by "xsubpp" to hook up XSUBs as Perl subs.	filename needs to be static
	       storage, as it is used directly as CvFILE(), without a copy being made.

       op_append_elem
	       Append an item to the list of ops contained directly within a list-type op,
	       returning the lengthened list.  first is the list-type op, and last is the op to
	       append to the list.  optype specifies the intended opcode for the list.	If first
	       is not already a list of the right type, it will be upgraded into one.  If either
	       first or last is null, the other is returned unchanged.

		       OP *    op_append_elem(I32 optype, OP *first, OP *last)

       op_append_list
	       Concatenate the lists of ops contained directly within two list-type ops,
	       returning the combined list.  first and last are the list-type ops to concatenate.
	       optype specifies the intended opcode for the list.  If either first or last is not
	       already a list of the right type, it will be upgraded into one.	If either first
	       or last is null, the other is returned unchanged.

		       OP *    op_append_list(I32 optype, OP *first, OP *last)

       OP_CLASS
	       Return the class of the provided OP: that is, which of the *OP structures it uses.
	       For core ops this currently gets the information out of PL_opargs, which does not
	       always accurately reflect the type used.  For custom ops the type is returned from
	       the registration, and it is up to the registree to ensure it is accurate. The
	       value returned will be one of the OA_* constants from op.h.

		       U32     OP_CLASS(OP *o)

       OP_DESC Return a short description of the provided OP.

		       const char * OP_DESC(OP *o)

       op_linklist
	       This function is the implementation of the "LINKLIST" macro. It should not be
	       called directly.

		       OP*     op_linklist(OP *o)

       op_lvalue
	       Propagate lvalue ("modifiable") context to an op and its children.  type
	       represents the context type, roughly based on the type of op that would do the
	       modifying, although "local()" is represented by OP_NULL, because it has no op type
	       of its own (it is signalled by a flag on the lvalue op).

	       This function detects things that can't be modified, such as "$x+1", and generates
	       errors for them. For example, "$x+1 = 2" would cause it to be called with an op of
	       type OP_ADD and a "type" argument of OP_SASSIGN.

	       It also flags things that need to behave specially in an lvalue context, such as
	       "$$x = 5" which might have to vivify a reference in $x.

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

		       OP *    op_lvalue(OP *o, I32 type)

       OP_NAME Return the name of the provided OP. For core ops this looks up the name from the
	       op_type; for custom ops from the op_ppaddr.

		       const char * OP_NAME(OP *o)

       op_prepend_elem
	       Prepend an item to the list of ops contained directly within a list-type op,
	       returning the lengthened list.  first is the op to prepend to the list, and last
	       is the list-type op.  optype specifies the intended opcode for the list.  If last
	       is not already a list of the right type, it will be upgraded into one.  If either
	       first or last is null, the other is returned unchanged.

		       OP *    op_prepend_elem(I32 optype, OP *first, OP *last)

       op_scope
	       Wraps up an op tree with some additional ops so that at runtime a dynamic scope
	       will be created.  The original ops run in the new dynamic scope, and then,
	       provided that they exit normally, the scope will be unwound.  The additional ops
	       used to create and unwind the dynamic scope will normally be an "enter"/"leave"
	       pair, but a "scope" op may be used instead if the ops are simple enough to not
	       need the full dynamic scope structure.

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

		       OP *    op_scope(OP *o)

       rv2cv_op_cv
	       Examines an op, which is expected to identify a subroutine at runtime, and
	       attempts to determine at compile time which subroutine it identifies.  This is
	       normally used during Perl compilation to determine whether a prototype can be
	       applied to a function call.  cvop is the op being considered, normally an "rv2cv"
	       op.  A pointer to the identified subroutine is returned, if it could be determined
	       statically, and a null pointer is returned if it was not possible to determine
	       statically.

	       Currently, the subroutine can be identified statically if the RV that the "rv2cv"
	       is to operate on is provided by a suitable "gv" or "const" op.  A "gv" op is
	       suitable if the GV's CV slot is populated.  A "const" op is suitable if the
	       constant value must be an RV pointing to a CV.  Details of this process may change
	       in future versions of Perl.  If the "rv2cv" op has the "OPpENTERSUB_AMPER" flag
	       set then no attempt is made to identify the subroutine statically: this flag is
	       used to suppress compile-time magic on a subroutine call, forcing it to use
	       default runtime behaviour.

	       If flags has the bit "RV2CVOPCV_MARK_EARLY" set, then the handling of a GV
	       reference is modified.  If a GV was examined and its CV slot was found to be
	       empty, then the "gv" op has the "OPpEARLY_CV" flag set.	If the op is not
	       optimised away, and the CV slot is later populated with a subroutine having a
	       prototype, that flag eventually triggers the warning "called too early to check
	       prototype".

	       If flags has the bit "RV2CVOPCV_RETURN_NAME_GV" set, then instead of returning a
	       pointer to the subroutine it returns a pointer to the GV giving the most
	       appropriate name for the subroutine in this context.  Normally this is just the
	       "CvGV" of the subroutine, but for an anonymous ("CvANON") subroutine that is
	       referenced through a GV it will be the referencing GV.  The resulting "GV*" is
	       cast to "CV*" to be returned.  A null pointer is returned as usual if there is no
	       statically-determinable subroutine.

		       CV *    rv2cv_op_cv(OP *cvop, U32 flags)

Pad Data Structures
       CvPADLIST
	       CV's can have CvPADLIST(cv) set to point to an AV.  This is the CV's scratchpad,
	       which stores lexical variables and opcode temporary and per-thread values.

	       For these purposes "forms" are a kind-of CV, eval""s are too (except they're not
	       callable at will and are always thrown away after the eval"" is done executing).
	       Require'd files are simply evals without any outer lexical scope.

	       XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad, but that
	       is really the callers pad (a slot of which is allocated by every entersub).

	       The CvPADLIST AV has the REFCNT of its component items managed "manually" (mostly
	       in pad.c) rather than by normal av.c rules.  So we turn off AvREAL just before
	       freeing it, to let av.c know not to touch the entries.  The items in the AV are
	       not SVs as for a normal AV, but other AVs:

	       0'th Entry of the CvPADLIST is an AV which represents the "names" or rather the
	       "static type information" for lexicals.

	       The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that
	       depth of recursion into the CV.	The 0'th slot of a frame AV is an AV which is @_.
	       other entries are storage for variables and op targets.

	       Iterating over the names AV iterates over all possible pad items. Pad slots that
	       are SVs_PADTMP (targets/GVs/constants) end up having &PL_sv_undef "names" (see
	       pad_alloc()).

	       Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names.  The rest are
	       op targets/GVs/constants which are statically allocated or resolved at compile
	       time.  These don't have names by which they can be looked up from Perl code at run
	       time through eval"" like my/our variables can be.  Since they can't be looked up
	       by "name" but only by their index allocated at compile time (which is usually in
	       PL_op->op_targ), wasting a name SV for them doesn't make sense.

	       The SVs in the names AV have their PV being the name of the variable.
	       xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for which
	       the name is valid (accessed through the macros COP_SEQ_RANGE_LOW and _HIGH).
	       During compilation, these fields may hold the special value PERL_PADSEQ_INTRO to
	       indicate various stages:

		  COP_SEQ_RANGE_LOW	   _HIGH
		  -----------------	   -----
		  PERL_PADSEQ_INTRO	       0   variable not yet introduced:   { my ($x
		  valid-seq#   PERL_PADSEQ_INTRO   variable in scope:		  { my ($x)
		  valid-seq#	      valid-seq#   compilation of scope complete: { my ($x) }

	       For typed lexicals name SV is SVt_PVMG and SvSTASH points at the type.  For "our"
	       lexicals, the type is also SVt_PVMG, with the SvOURSTASH slot pointing at the
	       stash of the associated global (so that duplicate "our" declarations in the same
	       package can be detected).  SvUVX is sometimes hijacked to store the generation
	       number during compilation.

	       If SvFAKE is set on the name SV, then that slot in the frame AV is a REFCNT'ed
	       reference to a lexical from "outside". In this case, the name SV does not use xlow
	       and xhigh to store a cop_seq range, since it is in scope throughout. Instead xhigh
	       stores some flags containing info about the real lexical (is it declared in an
	       anon, and is it capable of being instantiated multiple times?), and for fake
	       ANONs, xlow contains the index within the parent's pad where the lexical's value
	       is stored, to make cloning quicker.

	       If the 'name' is '&' the corresponding entry in frame AV is a CV representing a
	       possible closure.  (SvFAKE and name of '&' is not a meaningful combination
	       currently but could become so if "my sub foo {}" is implemented.)

	       Note that formats are treated as anon subs, and are cloned each time write is
	       called (if necessary).

	       The flag SVs_PADSTALE is cleared on lexicals each time the my() is executed, and
	       set on scope exit. This allows the 'Variable $x is not available' warning to be
	       generated in evals, such as

		   { my $x = 1; sub f { eval '$x'} } f();

	       For state vars, SVs_PADSTALE is overloaded to mean 'not yet initialised'

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

		       PADLIST * CvPADLIST(CV *cv)

       pad_add_name_pvs
	       Exactly like "pad_add_name_pvn", but takes a literal string instead of a
	       string/length pair.

		       PADOFFSET pad_add_name_pvs(const char *name, U32 flags,
						  HV *typestash, HV *ourstash)

       pad_findmy_pvs
	       Exactly like "pad_findmy_pvn", but takes a literal string instead of a
	       string/length pair.

		       PADOFFSET pad_findmy_pvs(const char *name, U32 flags)

       pad_new Create a new padlist, updating the global variables for the currently-compiling
	       padlist to point to the new padlist.  The following flags can be OR'ed together:

		   padnew_CLONE        this pad is for a cloned CV
		   padnew_SAVE	       save old globals on the save stack
		   padnew_SAVESUB      also save extra stuff for start of sub

		       PADLIST * pad_new(int flags)

       PL_comppad
	       During compilation, this points to the array containing the values part of the pad
	       for the currently-compiling code.  (At runtime a CV may have many such value
	       arrays; at compile time just one is constructed.)  At runtime, this points to the
	       array containing the currently-relevant values for the pad for the currently-
	       executing code.

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

       PL_comppad_name
	       During compilation, this points to the array containing the names part of the pad
	       for the currently-compiling code.

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

       PL_curpad
	       Points directly to the body of the "PL_comppad" array.  (I.e., this is
	       "AvARRAY(PL_comppad)".)

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

Per-Interpreter Variables
       PL_modglobal
	       "PL_modglobal" is a general purpose, interpreter global HV for use by extensions
	       that need to keep information on a per-interpreter basis.  In a pinch, it can also
	       be used as a symbol table for extensions to share data among each other.  It is a
	       good idea to use keys prefixed by the package name of the extension that owns the
	       data.

		       HV*     PL_modglobal

       PL_na   A convenience variable which is typically used with "SvPV" when one doesn't care
	       about the length of the string.	It is usually more efficient to either declare a
	       local variable and use that instead or to use the "SvPV_nolen" macro.

		       STRLEN  PL_na

       PL_opfreehook
	       When non-"NULL", the function pointed by this variable will be called each time an
	       OP is freed with the corresponding OP as the argument.  This allows extensions to
	       free any extra attribute they have locally attached to an OP.  It is also assured
	       to first fire for the parent OP and then for its kids.

	       When you replace this variable, it is considered a good practice to store the
	       possibly previously installed hook and that you recall it inside your own.

		       Perl_ophook_t   PL_opfreehook

       PL_peepp
	       Pointer to the per-subroutine peephole optimiser.  This is a function that gets
	       called at the end of compilation of a Perl subroutine (or equivalently independent
	       piece of Perl code) to perform fixups of some ops and to perform small-scale
	       optimisations.  The function is called once for each subroutine that is compiled,
	       and is passed, as sole parameter, a pointer to the op that is the entry point to
	       the subroutine.	It modifies the op tree in place.

	       The peephole optimiser should never be completely replaced.  Rather, add code to
	       it by wrapping the existing optimiser.  The basic way to do this can be seen in
	       "Compile pass 3: peephole optimization" in perlguts.  If the new code wishes to
	       operate on ops throughout the subroutine's structure, rather than just at the top
	       level, it is likely to be more convenient to wrap the "PL_rpeepp" hook.

		       peep_t  PL_peepp

       PL_rpeepp
	       Pointer to the recursive peephole optimiser.  This is a function that gets called
	       at the end of compilation of a Perl subroutine (or equivalently independent piece
	       of Perl code) to perform fixups of some ops and to perform small-scale
	       optimisations.  The function is called once for each chain of ops linked through
	       their "op_next" fields; it is recursively called to handle each side chain.  It is
	       passed, as sole parameter, a pointer to the op that is at the head of the chain.
	       It modifies the op tree in place.

	       The peephole optimiser should never be completely replaced.  Rather, add code to
	       it by wrapping the existing optimiser.  The basic way to do this can be seen in
	       "Compile pass 3: peephole optimization" in perlguts.  If the new code wishes to
	       operate only on ops at a subroutine's top level, rather than throughout the
	       structure, it is likely to be more convenient to wrap the "PL_peepp" hook.

		       peep_t  PL_rpeepp

       PL_sv_no
	       This is the "false" SV.	See "PL_sv_yes".  Always refer to this as &PL_sv_no.

		       SV      PL_sv_no

       PL_sv_undef
	       This is the "undef" SV.	Always refer to this as &PL_sv_undef.

		       SV      PL_sv_undef

       PL_sv_yes
	       This is the "true" SV.  See "PL_sv_no".	Always refer to this as &PL_sv_yes.

		       SV      PL_sv_yes

REGEXP Functions
       SvRX    Convenience macro to get the REGEXP from a SV. This is approximately equivalent to
	       the following snippet:

		   if (SvMAGICAL(sv))
		       mg_get(sv);
		   if (SvROK(sv))
		       sv = MUTABLE_SV(SvRV(sv));
		   if (SvTYPE(sv) == SVt_REGEXP)
		       return (REGEXP*) sv;

	       NULL will be returned if a REGEXP* is not found.

		       REGEXP * SvRX(SV *sv)

       SvRXOK  Returns a boolean indicating whether the SV (or the one it references) is a
	       REGEXP.

	       If you want to do something with the REGEXP* later use SvRX instead and check for
	       NULL.

		       bool    SvRXOK(SV* sv)

Simple Exception Handling Macros
       dXCPT   Set up necessary local variables for exception handling.  See "Exception Handling"
	       in perlguts.

			       dXCPT;

       XCPT_CATCH
	       Introduces a catch block.  See "Exception Handling" in perlguts.

       XCPT_RETHROW
	       Rethrows a previously caught exception.	See "Exception Handling" in perlguts.

			       XCPT_RETHROW;

       XCPT_TRY_END
	       Ends a try block.  See "Exception Handling" in perlguts.

       XCPT_TRY_START
	       Starts a try block.  See "Exception Handling" in perlguts.

Stack Manipulation Macros
       dMARK   Declare a stack marker variable, "mark", for the XSUB.  See "MARK" and
	       "dORIGMARK".

			       dMARK;

       dORIGMARK
	       Saves the original stack mark for the XSUB.  See "ORIGMARK".

			       dORIGMARK;

       dSP     Declares a local copy of perl's stack pointer for the XSUB, available via the "SP"
	       macro.  See "SP".

			       dSP;

       EXTEND  Used to extend the argument stack for an XSUB's return values. Once used,
	       guarantees that there is room for at least "nitems" to be pushed onto the stack.

		       void    EXTEND(SP, int nitems)

       MARK    Stack marker variable for the XSUB.  See "dMARK".

       mPUSHi  Push an integer onto the stack.	The stack must have room for this element.  Does
	       not use "TARG".	See also "PUSHi", "mXPUSHi" and "XPUSHi".

		       void    mPUSHi(IV iv)

       mPUSHn  Push a double onto the stack.  The stack must have room for this element.  Does
	       not use "TARG".	See also "PUSHn", "mXPUSHn" and "XPUSHn".

		       void    mPUSHn(NV nv)

       mPUSHp  Push a string onto the stack.  The stack must have room for this element.  The
	       "len" indicates the length of the string.  Does not use "TARG".	See also "PUSHp",
	       "mXPUSHp" and "XPUSHp".

		       void    mPUSHp(char* str, STRLEN len)

       mPUSHs  Push an SV onto the stack and mortalizes the SV.  The stack must have room for
	       this element.  Does not use "TARG".  See also "PUSHs" and "mXPUSHs".

		       void    mPUSHs(SV* sv)

       mPUSHu  Push an unsigned integer onto the stack.  The stack must have room for this
	       element.  Does not use "TARG".  See also "PUSHu", "mXPUSHu" and "XPUSHu".

		       void    mPUSHu(UV uv)

       mXPUSHi Push an integer onto the stack, extending the stack if necessary.  Does not use
	       "TARG".	See also "XPUSHi", "mPUSHi" and "PUSHi".

		       void    mXPUSHi(IV iv)

       mXPUSHn Push a double onto the stack, extending the stack if necessary.	Does not use
	       "TARG".	See also "XPUSHn", "mPUSHn" and "PUSHn".

		       void    mXPUSHn(NV nv)

       mXPUSHp Push a string onto the stack, extending the stack if necessary.	The "len"
	       indicates the length of the string.  Does not use "TARG".  See also "XPUSHp",
	       "mPUSHp" and "PUSHp".

		       void    mXPUSHp(char* str, STRLEN len)

       mXPUSHs Push an SV onto the stack, extending the stack if necessary and mortalizes the SV.
	       Does not use "TARG".  See also "XPUSHs" and "mPUSHs".

		       void    mXPUSHs(SV* sv)

       mXPUSHu Push an unsigned integer onto the stack, extending the stack if necessary.  Does
	       not use "TARG".	See also "XPUSHu", "mPUSHu" and "PUSHu".

		       void    mXPUSHu(UV uv)

       ORIGMARK
	       The original stack mark for the XSUB.  See "dORIGMARK".

       POPi    Pops an integer off the stack.

		       IV      POPi

       POPl    Pops a long off the stack.

		       long    POPl

       POPn    Pops a double off the stack.

		       NV      POPn

       POPp    Pops a string off the stack. Deprecated. New code should use POPpx.

		       char*   POPp

       POPpbytex
	       Pops a string off the stack which must consist of bytes i.e. characters < 256.

		       char*   POPpbytex

       POPpx   Pops a string off the stack.

		       char*   POPpx

       POPs    Pops an SV off the stack.

		       SV*     POPs

       PUSHi   Push an integer onto the stack.	The stack must have room for this element.
	       Handles 'set' magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be called to
	       declare it.  Do not call multiple "TARG"-oriented macros to return lists from
	       XSUB's - see "mPUSHi" instead.  See also "XPUSHi" and "mXPUSHi".

		       void    PUSHi(IV iv)

       PUSHMARK
	       Opening bracket for arguments on a callback.  See "PUTBACK" and perlcall.

		       void    PUSHMARK(SP)

       PUSHmortal
	       Push a new mortal SV onto the stack.  The stack must have room for this element.
	       Does not use "TARG".  See also "PUSHs", "XPUSHmortal" and "XPUSHs".

		       void    PUSHmortal()

       PUSHn   Push a double onto the stack.  The stack must have room for this element.  Handles
	       'set' magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare
	       it.  Do not call multiple "TARG"-oriented macros to return lists from XSUB's - see
	       "mPUSHn" instead.  See also "XPUSHn" and "mXPUSHn".

		       void    PUSHn(NV nv)

       PUSHp   Push a string onto the stack.  The stack must have room for this element.  The
	       "len" indicates the length of the string.  Handles 'set' magic.	Uses "TARG", so
	       "dTARGET" or "dXSTARG" should be called to declare it.  Do not call multiple
	       "TARG"-oriented macros to return lists from XSUB's - see "mPUSHp" instead.  See
	       also "XPUSHp" and "mXPUSHp".

		       void    PUSHp(char* str, STRLEN len)

       PUSHs   Push an SV onto the stack.  The stack must have room for this element.  Does not
	       handle 'set' magic.  Does not use "TARG".  See also "PUSHmortal", "XPUSHs" and
	       "XPUSHmortal".

		       void    PUSHs(SV* sv)

       PUSHu   Push an unsigned integer onto the stack.  The stack must have room for this
	       element.  Handles 'set' magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be
	       called to declare it.  Do not call multiple "TARG"-oriented macros to return lists
	       from XSUB's - see "mPUSHu" instead.  See also "XPUSHu" and "mXPUSHu".

		       void    PUSHu(UV uv)

       PUTBACK Closing bracket for XSUB arguments.  This is usually handled by "xsubpp".  See
	       "PUSHMARK" and perlcall for other uses.

			       PUTBACK;

       SP      Stack pointer.  This is usually handled by "xsubpp".  See "dSP" and "SPAGAIN".

       SPAGAIN Refetch the stack pointer.  Used after a callback.  See perlcall.

			       SPAGAIN;

       XPUSHi  Push an integer onto the stack, extending the stack if necessary.  Handles 'set'
	       magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it.  Do
	       not call multiple "TARG"-oriented macros to return lists from XSUB's - see
	       "mXPUSHi" instead.  See also "PUSHi" and "mPUSHi".

		       void    XPUSHi(IV iv)

       XPUSHmortal
	       Push a new mortal SV onto the stack, extending the stack if necessary.  Does not
	       use "TARG".  See also "XPUSHs", "PUSHmortal" and "PUSHs".

		       void    XPUSHmortal()

       XPUSHn  Push a double onto the stack, extending the stack if necessary.	Handles 'set'
	       magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it.  Do
	       not call multiple "TARG"-oriented macros to return lists from XSUB's - see
	       "mXPUSHn" instead.  See also "PUSHn" and "mPUSHn".

		       void    XPUSHn(NV nv)

       XPUSHp  Push a string onto the stack, extending the stack if necessary.	The "len"
	       indicates the length of the string.  Handles 'set' magic.  Uses "TARG", so
	       "dTARGET" or "dXSTARG" should be called to declare it.  Do not call multiple
	       "TARG"-oriented macros to return lists from XSUB's - see "mXPUSHp" instead.  See
	       also "PUSHp" and "mPUSHp".

		       void    XPUSHp(char* str, STRLEN len)

       XPUSHs  Push an SV onto the stack, extending the stack if necessary.  Does not handle
	       'set' magic.  Does not use "TARG".  See also "XPUSHmortal", "PUSHs" and
	       "PUSHmortal".

		       void    XPUSHs(SV* sv)

       XPUSHu  Push an unsigned integer onto the stack, extending the stack if necessary.
	       Handles 'set' magic.  Uses "TARG", so "dTARGET" or "dXSTARG" should be called to
	       declare it.  Do not call multiple "TARG"-oriented macros to return lists from
	       XSUB's - see "mXPUSHu" instead.	See also "PUSHu" and "mPUSHu".

		       void    XPUSHu(UV uv)

       XSRETURN
	       Return from XSUB, indicating number of items on the stack.  This is usually
	       handled by "xsubpp".

		       void    XSRETURN(int nitems)

       XSRETURN_EMPTY
	       Return an empty list from an XSUB immediately.

			       XSRETURN_EMPTY;

       XSRETURN_IV
	       Return an integer from an XSUB immediately.  Uses "XST_mIV".

		       void    XSRETURN_IV(IV iv)

       XSRETURN_NO
	       Return &PL_sv_no from an XSUB immediately.  Uses "XST_mNO".

			       XSRETURN_NO;

       XSRETURN_NV
	       Return a double from an XSUB immediately.  Uses "XST_mNV".

		       void    XSRETURN_NV(NV nv)

       XSRETURN_PV
	       Return a copy of a string from an XSUB immediately.  Uses "XST_mPV".

		       void    XSRETURN_PV(char* str)

       XSRETURN_UNDEF
	       Return &PL_sv_undef from an XSUB immediately.  Uses "XST_mUNDEF".

			       XSRETURN_UNDEF;

       XSRETURN_UV
	       Return an integer from an XSUB immediately.  Uses "XST_mUV".

		       void    XSRETURN_UV(IV uv)

       XSRETURN_YES
	       Return &PL_sv_yes from an XSUB immediately.  Uses "XST_mYES".

			       XSRETURN_YES;

       XST_mIV Place an integer into the specified position "pos" on the stack.  The value is
	       stored in a new mortal SV.

		       void    XST_mIV(int pos, IV iv)

       XST_mNO Place &PL_sv_no into the specified position "pos" on the stack.

		       void    XST_mNO(int pos)

       XST_mNV Place a double into the specified position "pos" on the stack.  The value is
	       stored in a new mortal SV.

		       void    XST_mNV(int pos, NV nv)

       XST_mPV Place a copy of a string into the specified position "pos" on the stack.  The
	       value is stored in a new mortal SV.

		       void    XST_mPV(int pos, char* str)

       XST_mUNDEF
	       Place &PL_sv_undef into the specified position "pos" on the stack.

		       void    XST_mUNDEF(int pos)

       XST_mYES
	       Place &PL_sv_yes into the specified position "pos" on the stack.

		       void    XST_mYES(int pos)

SV Flags
       svtype  An enum of flags for Perl types.  These are found in the file sv.h in the "svtype"
	       enum.  Test these flags with the "SvTYPE" macro.

       SVt_IV  Integer type flag for scalars.  See "svtype".

       SVt_NV  Double type flag for scalars.  See "svtype".

       SVt_PV  Pointer type flag for scalars.  See "svtype".

       SVt_PVAV
	       Type flag for arrays.  See "svtype".

       SVt_PVCV
	       Type flag for code refs.  See "svtype".

       SVt_PVHV
	       Type flag for hashes.  See "svtype".

       SVt_PVMG
	       Type flag for blessed scalars.  See "svtype".

SV Manipulation Functions
       boolSV  Returns a true SV if "b" is a true value, or a false SV if "b" is 0.

	       See also "PL_sv_yes" and "PL_sv_no".

		       SV *    boolSV(bool b)

       croak_xs_usage
	       A specialised variant of "croak()" for emitting the usage message for xsubs

		   croak_xs_usage(cv, "eee_yow");

	       works out the package name and subroutine name from "cv", and then calls
	       "croak()". Hence if "cv" is &ouch::awk, it would call "croak" as:

		   Perl_croak(aTHX_ "Usage: %"SVf"::%"SVf"(%s)", "ouch" "awk", "eee_yow");

		       void    croak_xs_usage(const CV *const cv,
					      const char *const params)

       get_sv  Returns the SV of the specified Perl scalar.  "flags" are passed to "gv_fetchpv".
	       If "GV_ADD" is set and the Perl variable does not exist then it will be created.
	       If "flags" is zero and the variable does not exist then NULL is returned.

	       NOTE: the perl_ form of this function is deprecated.

		       SV*     get_sv(const char *name, I32 flags)

       newRV_inc
	       Creates an RV wrapper for an SV.  The reference count for the original SV is
	       incremented.

		       SV*     newRV_inc(SV* sv)

       newSVpvn_utf8
	       Creates a new SV and copies a string into it.  If utf8 is true, calls "SvUTF8_on"
	       on the new SV.  Implemented as a wrapper around "newSVpvn_flags".

		       SV*     newSVpvn_utf8(NULLOK const char* s, STRLEN len,
					     U32 utf8)

       SvCUR   Returns the length of the string which is in the SV.  See "SvLEN".

		       STRLEN  SvCUR(SV* sv)

       SvCUR_set
	       Set the current length of the string which is in the SV.  See "SvCUR" and
	       "SvIV_set".

		       void    SvCUR_set(SV* sv, STRLEN len)

       SvEND   Returns a pointer to the spot just after the last character in the string which is
	       in the SV, where there is usually a trailing null (even though Perl scalars do not
	       strictly require it).  See "SvCUR".  Access the character as *(SvEND(sv)).

	       Warning: If "SvCUR" is equal to "SvLEN", then "SvEND" points to unallocated
	       memory.

		       char*   SvEND(SV* sv)

       SvGAMAGIC
	       Returns true if the SV has get magic or overloading.  If either is true then the
	       scalar is active data, and has the potential to return a new value every time it
	       is accessed.  Hence you must be careful to only read it once per user logical
	       operation and work with that returned value.  If neither is true then the scalar's
	       value cannot change unless written to.

		       U32     SvGAMAGIC(SV* sv)

       SvGROW  Expands the character buffer in the SV so that it has room for the indicated
	       number of bytes (remember to reserve space for an extra trailing NUL character).
	       Calls "sv_grow" to perform the expansion if necessary.  Returns a pointer to the
	       character buffer.

		       char *  SvGROW(SV* sv, STRLEN len)

       SvIOK   Returns a U32 value indicating whether the SV contains an integer.

		       U32     SvIOK(SV* sv)

       SvIOKp  Returns a U32 value indicating whether the SV contains an integer.  Checks the
	       private setting.  Use "SvIOK" instead.

		       U32     SvIOKp(SV* sv)

       SvIOK_notUV
	       Returns a boolean indicating whether the SV contains a signed integer.

		       bool    SvIOK_notUV(SV* sv)

       SvIOK_off
	       Unsets the IV status of an SV.

		       void    SvIOK_off(SV* sv)

       SvIOK_on
	       Tells an SV that it is an integer.

		       void    SvIOK_on(SV* sv)

       SvIOK_only
	       Tells an SV that it is an integer and disables all other OK bits.

		       void    SvIOK_only(SV* sv)

       SvIOK_only_UV
	       Tells and SV that it is an unsigned integer and disables all other OK bits.

		       void    SvIOK_only_UV(SV* sv)

       SvIOK_UV
	       Returns a boolean indicating whether the SV contains an unsigned integer.

		       bool    SvIOK_UV(SV* sv)

       SvIsCOW Returns a boolean indicating whether the SV is Copy-On-Write (either shared hash
	       key scalars, or full Copy On Write scalars if 5.9.0 is configured for COW).

		       bool    SvIsCOW(SV* sv)

       SvIsCOW_shared_hash
	       Returns a boolean indicating whether the SV is Copy-On-Write shared hash key
	       scalar.

		       bool    SvIsCOW_shared_hash(SV* sv)

       SvIV    Coerces the given SV to an integer and returns it.  See "SvIVx" for a version
	       which guarantees to evaluate sv only once.

		       IV      SvIV(SV* sv)

       SvIVX   Returns the raw value in the SV's IV slot, without checks or conversions.  Only
	       use when you are sure SvIOK is true.  See also "SvIV()".

		       IV      SvIVX(SV* sv)

       SvIVx   Coerces the given SV to an integer and returns it.  Guarantees to evaluate "sv"
	       only once.  Only use this if "sv" is an expression with side effects, otherwise
	       use the more efficient "SvIV".

		       IV      SvIVx(SV* sv)

       SvIV_nomg
	       Like "SvIV" but doesn't process magic.

		       IV      SvIV_nomg(SV* sv)

       SvIV_set
	       Set the value of the IV pointer in sv to val.  It is possible to perform the same
	       function of this macro with an lvalue assignment to "SvIVX".  With future Perls,
	       however, it will be more efficient to use "SvIV_set" instead of the lvalue
	       assignment to "SvIVX".

		       void    SvIV_set(SV* sv, IV val)

       SvLEN   Returns the size of the string buffer in the SV, not including any part
	       attributable to "SvOOK".  See "SvCUR".

		       STRLEN  SvLEN(SV* sv)

       SvLEN_set
	       Set the actual length of the string which is in the SV.	See "SvIV_set".

		       void    SvLEN_set(SV* sv, STRLEN len)

       SvMAGIC_set
	       Set the value of the MAGIC pointer in sv to val.  See "SvIV_set".

		       void    SvMAGIC_set(SV* sv, MAGIC* val)

       SvNIOK  Returns a U32 value indicating whether the SV contains a number, integer or
	       double.

		       U32     SvNIOK(SV* sv)

       SvNIOKp Returns a U32 value indicating whether the SV contains a number, integer or
	       double.	Checks the private setting.  Use "SvNIOK" instead.

		       U32     SvNIOKp(SV* sv)

       SvNIOK_off
	       Unsets the NV/IV status of an SV.

		       void    SvNIOK_off(SV* sv)

       SvNOK   Returns a U32 value indicating whether the SV contains a double.

		       U32     SvNOK(SV* sv)

       SvNOKp  Returns a U32 value indicating whether the SV contains a double.  Checks the
	       private setting.  Use "SvNOK" instead.

		       U32     SvNOKp(SV* sv)

       SvNOK_off
	       Unsets the NV status of an SV.

		       void    SvNOK_off(SV* sv)

       SvNOK_on
	       Tells an SV that it is a double.

		       void    SvNOK_on(SV* sv)

       SvNOK_only
	       Tells an SV that it is a double and disables all other OK bits.

		       void    SvNOK_only(SV* sv)

       SvNV    Coerce the given SV to a double and return it.  See "SvNVx" for a version which
	       guarantees to evaluate sv only once.

		       NV      SvNV(SV* sv)

       SvNVX   Returns the raw value in the SV's NV slot, without checks or conversions.  Only
	       use when you are sure SvNOK is true.  See also "SvNV()".

		       NV      SvNVX(SV* sv)

       SvNVx   Coerces the given SV to a double and returns it.  Guarantees to evaluate "sv" only
	       once.  Only use this if "sv" is an expression with side effects, otherwise use the
	       more efficient "SvNV".

		       NV      SvNVx(SV* sv)

       SvNV_nomg
	       Like "SvNV" but doesn't process magic.

		       NV      SvNV_nomg(SV* sv)

       SvNV_set
	       Set the value of the NV pointer in sv to val.  See "SvIV_set".

		       void    SvNV_set(SV* sv, NV val)

       SvOK    Returns a U32 value indicating whether the value is defined. This is only
	       meaningful for scalars.

		       U32     SvOK(SV* sv)

       SvOOK   Returns a U32 indicating whether the pointer to the string buffer is offset.  This
	       hack is used internally to speed up removal of characters from the beginning of a
	       SvPV.  When SvOOK is true, then the start of the allocated string buffer is
	       actually "SvOOK_offset()" bytes before SvPVX.  This offset used to be stored in
	       SvIVX, but is now stored within the spare part of the buffer.

		       U32     SvOOK(SV* sv)

       SvOOK_offset
	       Reads into len the offset from SvPVX back to the true start of the allocated
	       buffer, which will be non-zero if "sv_chop" has been used to efficiently remove
	       characters from start of the buffer.  Implemented as a macro, which takes the
	       address of len, which must be of type "STRLEN".	Evaluates sv more than once.
	       Sets len to 0 if "SvOOK(sv)" is false.

		       void    SvOOK_offset(NN SV*sv, STRLEN len)

       SvPOK   Returns a U32 value indicating whether the SV contains a character string.

		       U32     SvPOK(SV* sv)

       SvPOKp  Returns a U32 value indicating whether the SV contains a character string.  Checks
	       the private setting.  Use "SvPOK" instead.

		       U32     SvPOKp(SV* sv)

       SvPOK_off
	       Unsets the PV status of an SV.

		       void    SvPOK_off(SV* sv)

       SvPOK_on
	       Tells an SV that it is a string.

		       void    SvPOK_on(SV* sv)

       SvPOK_only
	       Tells an SV that it is a string and disables all other OK bits.	Will also turn
	       off the UTF-8 status.

		       void    SvPOK_only(SV* sv)

       SvPOK_only_UTF8
	       Tells an SV that it is a string and disables all other OK bits, and leaves the
	       UTF-8 status as it was.

		       void    SvPOK_only_UTF8(SV* sv)

       SvPV    Returns a pointer to the string in the SV, or a stringified form of the SV if the
	       SV does not contain a string.  The SV may cache the stringified version becoming
	       "SvPOK".  Handles 'get' magic.  See also "SvPVx" for a version which guarantees to
	       evaluate sv only once.

		       char*   SvPV(SV* sv, STRLEN len)

       SvPVbyte
	       Like "SvPV", but converts sv to byte representation first if necessary.

		       char*   SvPVbyte(SV* sv, STRLEN len)

       SvPVbytex
	       Like "SvPV", but converts sv to byte representation first if necessary.
	       Guarantees to evaluate sv only once; use the more efficient "SvPVbyte" otherwise.

		       char*   SvPVbytex(SV* sv, STRLEN len)

       SvPVbytex_force
	       Like "SvPV_force", but converts sv to byte representation first if necessary.
	       Guarantees to evaluate sv only once; use the more efficient "SvPVbyte_force"
	       otherwise.

		       char*   SvPVbytex_force(SV* sv, STRLEN len)

       SvPVbyte_force
	       Like "SvPV_force", but converts sv to byte representation first if necessary.

		       char*   SvPVbyte_force(SV* sv, STRLEN len)

       SvPVbyte_nolen
	       Like "SvPV_nolen", but converts sv to byte representation first if necessary.

		       char*   SvPVbyte_nolen(SV* sv)

       SvPVutf8
	       Like "SvPV", but converts sv to utf8 first if necessary.

		       char*   SvPVutf8(SV* sv, STRLEN len)

       SvPVutf8x
	       Like "SvPV", but converts sv to utf8 first if necessary.  Guarantees to evaluate
	       sv only once; use the more efficient "SvPVutf8" otherwise.

		       char*   SvPVutf8x(SV* sv, STRLEN len)

       SvPVutf8x_force
	       Like "SvPV_force", but converts sv to utf8 first if necessary.  Guarantees to
	       evaluate sv only once; use the more efficient "SvPVutf8_force" otherwise.

		       char*   SvPVutf8x_force(SV* sv, STRLEN len)

       SvPVutf8_force
	       Like "SvPV_force", but converts sv to utf8 first if necessary.

		       char*   SvPVutf8_force(SV* sv, STRLEN len)

       SvPVutf8_nolen
	       Like "SvPV_nolen", but converts sv to utf8 first if necessary.

		       char*   SvPVutf8_nolen(SV* sv)

       SvPVX   Returns a pointer to the physical string in the SV.  The SV must contain a string.

	       This is also used to store the name of an autoloaded subroutine in an XS AUTOLOAD
	       routine.  See "Autoloading with XSUBs" in perlguts.

		       char*   SvPVX(SV* sv)

       SvPVx   A version of "SvPV" which guarantees to evaluate "sv" only once.  Only use this if
	       "sv" is an expression with side effects, otherwise use the more efficient "SvPV".

		       char*   SvPVx(SV* sv, STRLEN len)

       SvPV_force
	       Like "SvPV" but will force the SV into containing just a string ("SvPOK_only").
	       You want force if you are going to update the "SvPVX" directly.

		       char*   SvPV_force(SV* sv, STRLEN len)

       SvPV_force_nomg
	       Like "SvPV" but will force the SV into containing just a string ("SvPOK_only").
	       You want force if you are going to update the "SvPVX" directly.	Doesn't process
	       magic.

		       char*   SvPV_force_nomg(SV* sv, STRLEN len)

       SvPV_nolen
	       Returns a pointer to the string in the SV, or a stringified form of the SV if the
	       SV does not contain a string.  The SV may cache the stringified form becoming
	       "SvPOK".  Handles 'get' magic.

		       char*   SvPV_nolen(SV* sv)

       SvPV_nomg
	       Like "SvPV" but doesn't process magic.

		       char*   SvPV_nomg(SV* sv, STRLEN len)

       SvPV_nomg_nolen
	       Like "SvPV_nolen" but doesn't process magic.

		       char*   SvPV_nomg_nolen(SV* sv)

       SvPV_set
	       Set the value of the PV pointer in sv to val.  See "SvIV_set".

		       void    SvPV_set(SV* sv, char* val)

       SvREFCNT
	       Returns the value of the object's reference count.

		       U32     SvREFCNT(SV* sv)

       SvREFCNT_dec
	       Decrements the reference count of the given SV.

		       void    SvREFCNT_dec(SV* sv)

       SvREFCNT_inc
	       Increments the reference count of the given SV.

	       All of the following SvREFCNT_inc* macros are optimized versions of SvREFCNT_inc,
	       and can be replaced with SvREFCNT_inc.

		       SV*     SvREFCNT_inc(SV* sv)

       SvREFCNT_inc_NN
	       Same as SvREFCNT_inc, but can only be used if you know sv is not NULL.  Since we
	       don't have to check the NULLness, it's faster and smaller.

		       SV*     SvREFCNT_inc_NN(SV* sv)

       SvREFCNT_inc_simple
	       Same as SvREFCNT_inc, but can only be used with expressions without side effects.
	       Since we don't have to store a temporary value, it's faster.

		       SV*     SvREFCNT_inc_simple(SV* sv)

       SvREFCNT_inc_simple_NN
	       Same as SvREFCNT_inc_simple, but can only be used if you know sv is not NULL.
	       Since we don't have to check the NULLness, it's faster and smaller.

		       SV*     SvREFCNT_inc_simple_NN(SV* sv)

       SvREFCNT_inc_simple_void
	       Same as SvREFCNT_inc_simple, but can only be used if you don't need the return
	       value.  The macro doesn't need to return a meaningful value.

		       void    SvREFCNT_inc_simple_void(SV* sv)

       SvREFCNT_inc_simple_void_NN
	       Same as SvREFCNT_inc, but can only be used if you don't need the return value, and
	       you know that sv is not NULL.  The macro doesn't need to return a meaningful
	       value, or check for NULLness, so it's smaller and faster.

		       void    SvREFCNT_inc_simple_void_NN(SV* sv)

       SvREFCNT_inc_void
	       Same as SvREFCNT_inc, but can only be used if you don't need the return value.
	       The macro doesn't need to return a meaningful value.

		       void    SvREFCNT_inc_void(SV* sv)

       SvREFCNT_inc_void_NN
	       Same as SvREFCNT_inc, but can only be used if you don't need the return value, and
	       you know that sv is not NULL.  The macro doesn't need to return a meaningful
	       value, or check for NULLness, so it's smaller and faster.

		       void    SvREFCNT_inc_void_NN(SV* sv)

       SvROK   Tests if the SV is an RV.

		       U32     SvROK(SV* sv)

       SvROK_off
	       Unsets the RV status of an SV.

		       void    SvROK_off(SV* sv)

       SvROK_on
	       Tells an SV that it is an RV.

		       void    SvROK_on(SV* sv)

       SvRV    Dereferences an RV to return the SV.

		       SV*     SvRV(SV* sv)

       SvRV_set
	       Set the value of the RV pointer in sv to val.  See "SvIV_set".

		       void    SvRV_set(SV* sv, SV* val)

       SvSTASH Returns the stash of the SV.

		       HV*     SvSTASH(SV* sv)

       SvSTASH_set
	       Set the value of the STASH pointer in sv to val.  See "SvIV_set".

		       void    SvSTASH_set(SV* sv, HV* val)

       SvTAINT Taints an SV if tainting is enabled, and if some input to the current expression
	       is tainted--usually a variable, but possibly also implicit inputs such as locale
	       settings.  "SvTAINT" propagates that taintedness to the outputs of an expression
	       in a pessimistic fashion; i.e., without paying attention to precisely which
	       outputs are influenced by which inputs.

		       void    SvTAINT(SV* sv)

       SvTAINTED
	       Checks to see if an SV is tainted.  Returns TRUE if it is, FALSE if not.

		       bool    SvTAINTED(SV* sv)

       SvTAINTED_off
	       Untaints an SV.	Be very careful with this routine, as it short-circuits some of
	       Perl's fundamental security features.  XS module authors should not use this
	       function unless they fully understand all the implications of unconditionally
	       untainting the value. Untainting should be done in the standard perl fashion, via
	       a carefully crafted regexp, rather than directly untainting variables.

		       void    SvTAINTED_off(SV* sv)

       SvTAINTED_on
	       Marks an SV as tainted if tainting is enabled.

		       void    SvTAINTED_on(SV* sv)

       SvTRUE  Returns a boolean indicating whether Perl would evaluate the SV as true or false.
	       See SvOK() for a defined/undefined test.  Handles 'get' magic unless the scalar is
	       already SvPOK, SvIOK or SvNOK (the public, not the private flags).

		       bool    SvTRUE(SV* sv)

       SvTRUE_nomg
	       Returns a boolean indicating whether Perl would evaluate the SV as true or false.
	       See SvOK() for a defined/undefined test.  Does not handle 'get' magic.

		       bool    SvTRUE_nomg(SV* sv)

       SvTYPE  Returns the type of the SV.  See "svtype".

		       svtype  SvTYPE(SV* sv)

       SvUOK   Returns a boolean indicating whether the SV contains an unsigned integer.

		       bool    SvUOK(SV* sv)

       SvUPGRADE
	       Used to upgrade an SV to a more complex form.  Uses "sv_upgrade" to perform the
	       upgrade if necessary.  See "svtype".

		       void    SvUPGRADE(SV* sv, svtype type)

       SvUTF8  Returns a U32 value indicating the UTF-8 status of an SV.  If things are set-up
	       properly, this indicates whether or not the SV contains UTF-8 encoded data.  Call
	       this after SvPV() in case any call to string overloading updates the internal
	       flag.

		       U32     SvUTF8(SV* sv)

       SvUTF8_off
	       Unsets the UTF-8 status of an SV (the data is not changed, just the flag).  Do not
	       use frivolously.

		       void    SvUTF8_off(SV *sv)

       SvUTF8_on
	       Turn on the UTF-8 status of an SV (the data is not changed, just the flag).  Do
	       not use frivolously.

		       void    SvUTF8_on(SV *sv)

       SvUV    Coerces the given SV to an unsigned integer and returns it.  See "SvUVx" for a
	       version which guarantees to evaluate sv only once.

		       UV      SvUV(SV* sv)

       SvUVX   Returns the raw value in the SV's UV slot, without checks or conversions.  Only
	       use when you are sure SvIOK is true.  See also "SvUV()".

		       UV      SvUVX(SV* sv)

       SvUVx   Coerces the given SV to an unsigned integer and returns it.  Guarantees to "sv"
	       only once.  Only use this if "sv" is an expression with side effects, otherwise
	       use the more efficient "SvUV".

		       UV      SvUVx(SV* sv)

       SvUV_nomg
	       Like "SvUV" but doesn't process magic.

		       UV      SvUV_nomg(SV* sv)

       SvUV_set
	       Set the value of the UV pointer in sv to val.  See "SvIV_set".

		       void    SvUV_set(SV* sv, UV val)

       SvVOK   Returns a boolean indicating whether the SV contains a v-string.

		       bool    SvVOK(SV* sv)

       sv_catpvn_nomg
	       Like "sv_catpvn" but doesn't process magic.

		       void    sv_catpvn_nomg(SV* sv, const char* ptr,
					      STRLEN len)

       sv_catpv_nomg
	       Like "sv_catpv" but doesn't process magic.

		       void    sv_catpv_nomg(SV* sv, const char* ptr)

       sv_catsv_nomg
	       Like "sv_catsv" but doesn't process magic.

		       void    sv_catsv_nomg(SV* dsv, SV* ssv)

       sv_derived_from
	       Exactly like "sv_derived_from_pv", but doesn't take a "flags" parameter.

		       bool    sv_derived_from(SV* sv, const char *const name)

       sv_derived_from_pv
	       Exactly like "sv_derived_from_pvn", but takes a nul-terminated string instead of a
	       string/length pair.

		       bool    sv_derived_from_pv(SV* sv,
						  const char *const name,
						  U32 flags)

       sv_derived_from_pvn
	       Returns a boolean indicating whether the SV is derived from the specified class at
	       the C level.  To check derivation at the Perl level, call "isa()" as a normal Perl
	       method.

	       Currently, the only significant value for "flags" is SVf_UTF8.

		       bool    sv_derived_from_pvn(SV* sv,
						   const char *const name,
						   const STRLEN len, U32 flags)

       sv_derived_from_sv
	       Exactly like "sv_derived_from_pvn", but takes the name string in the form of an SV
	       instead of a string/length pair.

		       bool    sv_derived_from_sv(SV* sv, SV *namesv,
						  U32 flags)

       sv_does Like "sv_does_pv", but doesn't take a "flags" parameter.

		       bool    sv_does(SV* sv, const char *const name)

       sv_does_pv
	       Like "sv_does_sv", but takes a nul-terminated string instead of an SV.

		       bool    sv_does_pv(SV* sv, const char *const name,
					  U32 flags)

       sv_does_pvn
	       Like "sv_does_sv", but takes a string/length pair instead of an SV.

		       bool    sv_does_pvn(SV* sv, const char *const name,
					   const STRLEN len, U32 flags)

       sv_does_sv
	       Returns a boolean indicating whether the SV performs a specific, named role.  The
	       SV can be a Perl object or the name of a Perl class.

		       bool    sv_does_sv(SV* sv, SV* namesv, U32 flags)

       sv_report_used
	       Dump the contents of all SVs not yet freed (debugging aid).

		       void    sv_report_used()

       sv_setsv_nomg
	       Like "sv_setsv" but doesn't process magic.

		       void    sv_setsv_nomg(SV* dsv, SV* ssv)

       sv_utf8_upgrade_nomg
	       Like sv_utf8_upgrade, but doesn't do magic on "sv".

		       STRLEN  sv_utf8_upgrade_nomg(NN SV *sv)

SV-Body Allocation
       looks_like_number
	       Test if the content of an SV looks like a number (or is a number).  "Inf" and
	       "Infinity" are treated as numbers (so will not issue a non-numeric warning), even
	       if your atof() doesn't grok them.  Get-magic is ignored.

		       I32     looks_like_number(SV *const sv)

       newRV_noinc
	       Creates an RV wrapper for an SV.  The reference count for the original SV is not
	       incremented.

		       SV*     newRV_noinc(SV *const sv)

       newSV   Creates a new SV.  A non-zero "len" parameter indicates the number of bytes of
	       preallocated string space the SV should have.  An extra byte for a trailing NUL is
	       also reserved.  (SvPOK is not set for the SV even if string space is allocated.)
	       The reference count for the new SV is set to 1.

	       In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first parameter,
	       x, a debug aid which allowed callers to identify themselves.  This aid has been
	       superseded by a new build option, PERL_MEM_LOG (see "PERL_MEM_LOG" in
	       perlhacktips).  The older API is still there for use in XS modules supporting
	       older perls.

		       SV*     newSV(const STRLEN len)

       newSVhek
	       Creates a new SV from the hash key structure.  It will generate scalars that point
	       to the shared string table where possible.  Returns a new (undefined) SV if the
	       hek is NULL.

		       SV*     newSVhek(const HEK *const hek)

       newSViv Creates a new SV and copies an integer into it.	The reference count for the SV is
	       set to 1.

		       SV*     newSViv(const IV i)

       newSVnv Creates a new SV and copies a floating point value into it.  The reference count
	       for the SV is set to 1.

		       SV*     newSVnv(const NV n)

       newSVpv Creates a new SV and copies a string into it.  The reference count for the SV is
	       set to 1.  If "len" is zero, Perl will compute the length using strlen().  For
	       efficiency, consider using "newSVpvn" instead.

		       SV*     newSVpv(const char *const s, const STRLEN len)

       newSVpvf
	       Creates a new SV and initializes it with the string formatted like "sprintf".

		       SV*     newSVpvf(const char *const pat, ...)

       newSVpvn
	       Creates a new SV and copies a buffer into it, which may contain NUL characters
	       ("\0") and other binary data.  The reference count for the SV is set to 1.  Note
	       that if "len" is zero, Perl will create a zero length (Perl) string.  You are
	       responsible for ensuring that the source buffer is at least "len" bytes long.  If
	       the "buffer" argument is NULL the new SV will be undefined.

		       SV*     newSVpvn(const char *const s, const STRLEN len)

       newSVpvn_flags
	       Creates a new SV and copies a string into it.  The reference count for the SV is
	       set to 1.  Note that if "len" is zero, Perl will create a zero length string.  You
	       are responsible for ensuring that the source string is at least "len" bytes long.
	       If the "s" argument is NULL the new SV will be undefined.  Currently the only flag
	       bits accepted are "SVf_UTF8" and "SVs_TEMP".  If "SVs_TEMP" is set, then
	       "sv_2mortal()" is called on the result before returning.  If "SVf_UTF8" is set,
	       "s" is considered to be in UTF-8 and the "SVf_UTF8" flag will be set on the new
	       SV.  "newSVpvn_utf8()" is a convenience wrapper for this function, defined as

		   #define newSVpvn_utf8(s, len, u)		       \
		       newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)

		       SV*     newSVpvn_flags(const char *const s,
					      const STRLEN len,
					      const U32 flags)

       newSVpvn_share
	       Creates a new SV with its SvPVX_const pointing to a shared string in the string
	       table.  If the string does not already exist in the table, it is created first.
	       Turns on READONLY and FAKE.  If the "hash" parameter is non-zero, that value is
	       used; otherwise the hash is computed.  The string's hash can later be retrieved
	       from the SV with the "SvSHARED_HASH()" macro.  The idea here is that as the string
	       table is used for shared hash keys these strings will have SvPVX_const == HeKEY
	       and hash lookup will avoid string compare.

		       SV*     newSVpvn_share(const char* s, I32 len, U32 hash)

       newSVpvs
	       Like "newSVpvn", but takes a literal string instead of a string/length pair.

		       SV*     newSVpvs(const char* s)

       newSVpvs_flags
	       Like "newSVpvn_flags", but takes a literal string instead of a string/length pair.

		       SV*     newSVpvs_flags(const char* s, U32 flags)

       newSVpvs_share
	       Like "newSVpvn_share", but takes a literal string instead of a string/length pair
	       and omits the hash parameter.

		       SV*     newSVpvs_share(const char* s)

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

		       SV*     newSVpv_share(const char* s, U32 hash)

       newSVrv Creates a new SV for the RV, "rv", to point to.	If "rv" is not an RV then it will
	       be upgraded to one.  If "classname" is non-null then the new SV will be blessed in
	       the specified package.  The new SV is returned and its reference count is 1.

		       SV*     newSVrv(SV *const rv,
				       const char *const classname)

       newSVsv Creates a new SV which is an exact duplicate of the original SV.  (Uses
	       "sv_setsv".)

		       SV*     newSVsv(SV *const old)

       newSVuv Creates a new SV and copies an unsigned integer into it.  The reference count for
	       the SV is set to 1.

		       SV*     newSVuv(const UV u)

       newSV_type
	       Creates a new SV, of the type specified.  The reference count for the new SV is
	       set to 1.

		       SV*     newSV_type(const svtype type)

       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 *const sv, const I32 flags)

       sv_2cv  Using various gambits, try to get a CV from an SV; in addition, try if possible to
	       set *st and *gvp to the stash and GV associated with it.  The flags in "lref" are
	       passed to gv_fetchsv.

		       CV*     sv_2cv(SV* sv, HV **const st, GV **const gvp,
				      const I32 lref)

       sv_2io  Using various gambits, try to get an IO from an SV: the IO slot if its a GV; or
	       the recursive result if we're an RV; or the IO slot of the symbol named after the
	       PV if we're a string.

	       'Get' magic is ignored on the sv passed in, but will be called on "SvRV(sv)" if sv
	       is an RV.

		       IO*     sv_2io(SV *const sv)

       sv_2iv_flags
	       Return the integer value of an SV, doing any necessary string conversion.  If
	       flags includes SV_GMAGIC, does an mg_get() first.  Normally used via the
	       "SvIV(sv)" and "SvIVx(sv)" macros.

		       IV      sv_2iv_flags(SV *const sv, const I32 flags)

       sv_2mortal
	       Marks an existing SV as mortal.	The SV will be destroyed "soon", either by an
	       explicit call to FREETMPS, or by an implicit call at places such as statement
	       boundaries.  SvTEMP() is turned on which means that the SV's string buffer can be
	       "stolen" if this SV is copied.  See also "sv_newmortal" and "sv_mortalcopy".

		       SV*     sv_2mortal(SV *const sv)

       sv_2nv_flags
	       Return the num value of an SV, doing any necessary string or integer conversion.
	       If flags includes SV_GMAGIC, does an mg_get() first.  Normally used via the
	       "SvNV(sv)" and "SvNVx(sv)" macros.

		       NV      sv_2nv_flags(SV *const sv, const I32 flags)

       sv_2pvbyte
	       Return a pointer to the byte-encoded representation of the SV, and set *lp to its
	       length.	May cause the SV to be downgraded from UTF-8 as a side-effect.

	       Usually accessed via the "SvPVbyte" macro.

		       char*   sv_2pvbyte(SV *sv, STRLEN *const lp)

       sv_2pvutf8
	       Return a pointer to the UTF-8-encoded representation of the SV, and set *lp to its
	       length.	May cause the SV to be upgraded to UTF-8 as a side-effect.

	       Usually accessed via the "SvPVutf8" macro.

		       char*   sv_2pvutf8(SV *sv, STRLEN *const lp)

       sv_2pv_flags
	       Returns a pointer to the string value of an SV, and sets *lp to its length.  If
	       flags includes SV_GMAGIC, does an mg_get() first.  Coerces sv to a string if
	       necessary.  Normally invoked via the "SvPV_flags" macro.  "sv_2pv()" and
	       "sv_2pv_nomg" usually end up here too.

		       char*   sv_2pv_flags(SV *const sv, STRLEN *const lp,
					    const I32 flags)

       sv_2uv_flags
	       Return the unsigned integer value of an SV, doing any necessary string conversion.
	       If flags includes SV_GMAGIC, does an mg_get() first.  Normally used via the
	       "SvUV(sv)" and "SvUVx(sv)" macros.

		       UV      sv_2uv_flags(SV *const sv, const I32 flags)

       sv_backoff
	       Remove any string offset.  You should normally use the "SvOOK_off" macro wrapper
	       instead.

		       int     sv_backoff(SV *const sv)

       sv_bless
	       Blesses an SV into a specified package.	The SV must be an RV.  The package must
	       be designated by its stash (see "gv_stashpv()").  The reference count of the SV is
	       unaffected.

		       SV*     sv_bless(SV *const sv, HV *const stash)

       sv_catpv
	       Concatenates the string onto the end of the string which is in the SV.  If the SV
	       has the UTF-8 status set, then the bytes appended should be valid UTF-8.  Handles
	       'get' magic, but not 'set' magic.  See "sv_catpv_mg".

		       void    sv_catpv(SV *const sv, const char* ptr)

       sv_catpvf
	       Processes its arguments like "sprintf" and appends the formatted output to an SV.
	       If the appended data contains "wide" characters (including, but not limited to,
	       SVs with a UTF-8 PV formatted with %s, and characters >255 formatted with %c), the
	       original SV might get upgraded to UTF-8.  Handles 'get' magic, but not 'set'
	       magic.  See "sv_catpvf_mg".  If the original SV was UTF-8, the pattern should be
	       valid UTF-8; if the original SV was bytes, the pattern should be too.

		       void    sv_catpvf(SV *const sv, const char *const pat,
					 ...)

       sv_catpvf_mg
	       Like "sv_catpvf", but also handles 'set' magic.

		       void    sv_catpvf_mg(SV *const sv,
					    const char *const pat, ...)

       sv_catpvn
	       Concatenates the string onto the end of the string which is in the SV.  The "len"
	       indicates number of bytes to copy.  If the SV has the UTF-8 status set, then the
	       bytes appended should be valid UTF-8.  Handles 'get' magic, but not 'set' magic.
	       See "sv_catpvn_mg".

		       void    sv_catpvn(SV *dsv, const char *sstr, STRLEN len)

       sv_catpvn_flags
	       Concatenates the string onto the end of the string which is in the SV.  The "len"
	       indicates number of bytes to copy.  If the SV has the UTF-8 status set, then the
	       bytes appended should be valid UTF-8.  If "flags" has the "SV_SMAGIC" bit set,
	       will "mg_set" on "dsv" afterwards if appropriate.  "sv_catpvn" and
	       "sv_catpvn_nomg" are implemented in terms of this function.

		       void    sv_catpvn_flags(SV *const dstr,
					       const char *sstr,
					       const STRLEN len,
					       const I32 flags)

       sv_catpvs
	       Like "sv_catpvn", but takes a literal string instead of a string/length pair.

		       void    sv_catpvs(SV* sv, const char* s)

       sv_catpvs_flags
	       Like "sv_catpvn_flags", but takes a literal string instead of a string/length
	       pair.

		       void    sv_catpvs_flags(SV* sv, const char* s,
					       I32 flags)

       sv_catpvs_mg
	       Like "sv_catpvn_mg", but takes a literal string instead of a string/length pair.

		       void    sv_catpvs_mg(SV* sv, const char* s)

       sv_catpvs_nomg
	       Like "sv_catpvn_nomg", but takes a literal string instead of a string/length pair.

		       void    sv_catpvs_nomg(SV* sv, const char* s)

       sv_catpv_flags
	       Concatenates the string onto the end of the string which is in the SV.  If the SV
	       has the UTF-8 status set, then the bytes appended should be valid UTF-8.  If
	       "flags" has the "SV_SMAGIC" bit set, will "mg_set" on the modified SV if
	       appropriate.

		       void    sv_catpv_flags(SV *dstr, const char *sstr,
					      const I32 flags)

       sv_catpv_mg
	       Like "sv_catpv", but also handles 'set' magic.

		       void    sv_catpv_mg(SV *const sv, const char *const ptr)

       sv_catsv
	       Concatenates the string from SV "ssv" onto the end of the string in SV "dsv".
	       Modifies "dsv" but not "ssv".  Handles 'get' magic, but not 'set' magic.  See
	       "sv_catsv_mg".

		       void    sv_catsv(SV *dstr, SV *sstr)

       sv_catsv_flags
	       Concatenates the string from SV "ssv" onto the end of the string in SV "dsv".
	       Modifies "dsv" but not "ssv".  If "flags" has "SV_GMAGIC" bit set, will "mg_get"
	       on the "ssv", if appropriate, before reading it.  If the "flags" contain
	       "SV_SMAGIC", "mg_set" will be called on the modified SV afterward, if appropriate.
	       "sv_catsv" and "sv_catsv_nomg" are implemented in terms of this function.

		       void    sv_catsv_flags(SV *const dsv, SV *const ssv,
					      const I32 flags)

       sv_chop Efficient removal of characters from the beginning of the string buffer.
	       SvPOK(sv) must be true and the "ptr" must be a pointer to somewhere inside the
	       string buffer.  The "ptr" becomes the first character of the adjusted string.
	       Uses the "OOK hack".

	       Beware: after this function returns, "ptr" and SvPVX_const(sv) may no longer refer
	       to the same chunk of data.

	       The unfortunate similarity of this function's name to that of Perl's "chop"
	       operator is strictly coincidental.  This function works from the left; "chop"
	       works from the right.

		       void    sv_chop(SV *const sv, const char *const ptr)

       sv_clear
	       Clear an SV: call any destructors, free up any memory used by the body, and free
	       the body itself.  The SV's head is not freed, although its type is set to all 1's
	       so that it won't inadvertently be assumed to be live during global destruction
	       etc.  This function should only be called when REFCNT is zero.  Most of the time
	       you'll want to call "sv_free()" (or its macro wrapper "SvREFCNT_dec") instead.

		       void    sv_clear(SV *const orig_sv)

       sv_cmp  Compares the strings in two SVs.  Returns -1, 0, or 1 indicating whether the
	       string in "sv1" is less than, equal to, or greater than the string in "sv2".  Is
	       UTF-8 and 'use bytes' aware, handles get magic, and will coerce its args to
	       strings if necessary.  See also "sv_cmp_locale".

		       I32     sv_cmp(SV *const sv1, SV *const sv2)

       sv_cmp_flags
	       Compares the strings in two SVs.  Returns -1, 0, or 1 indicating whether the
	       string in "sv1" is less than, equal to, or greater than the string in "sv2".  Is
	       UTF-8 and 'use bytes' aware and will coerce its args to strings if necessary.  If
	       the flags include SV_GMAGIC, it handles get magic.  See also
	       "sv_cmp_locale_flags".

		       I32     sv_cmp_flags(SV *const sv1, SV *const sv2,
					    const U32 flags)

       sv_cmp_locale
	       Compares the strings in two SVs in a locale-aware manner.  Is UTF-8 and 'use
	       bytes' aware, handles get magic, and will coerce its args to strings if necessary.
	       See also "sv_cmp".

		       I32     sv_cmp_locale(SV *const sv1, SV *const sv2)

       sv_cmp_locale_flags
	       Compares the strings in two SVs in a locale-aware manner.  Is UTF-8 and 'use
	       bytes' aware and will coerce its args to strings if necessary.  If the flags
	       contain SV_GMAGIC, it handles get magic.  See also "sv_cmp_flags".

		       I32     sv_cmp_locale_flags(SV *const sv1,
						   SV *const sv2,
						   const U32 flags)

       sv_collxfrm
	       This calls "sv_collxfrm_flags" with the SV_GMAGIC flag.	See "sv_collxfrm_flags".

		       char*   sv_collxfrm(SV *const sv, STRLEN *const nxp)

       sv_collxfrm_flags
	       Add Collate Transform magic to an SV if it doesn't already have it.  If the flags
	       contain SV_GMAGIC, it handles get-magic.

	       Any scalar variable may carry PERL_MAGIC_collxfrm magic that contains the scalar
	       data of the variable, but transformed to such a format that a normal memory
	       comparison can be used to compare the data according to the locale settings.

		       char*   sv_collxfrm_flags(SV *const sv,
						 STRLEN *const nxp,
						 I32 const flags)

       sv_copypv
	       Copies a stringified representation of the source SV into the destination SV.
	       Automatically performs any necessary mg_get and coercion of numeric values into
	       strings.  Guaranteed to preserve UTF8 flag even from overloaded objects.  Similar
	       in nature to sv_2pv[_flags] but operates directly on an SV instead of just the
	       string.	Mostly uses sv_2pv_flags to do its work, except when that would lose the
	       UTF-8'ness of the PV.

		       void    sv_copypv(SV *const dsv, SV *const ssv)

       sv_dec  Auto-decrement of the value in the SV, doing string to numeric conversion if
	       necessary.  Handles 'get' magic and operator overloading.

		       void    sv_dec(SV *const sv)

       sv_dec_nomg
	       Auto-decrement of the value in the SV, doing string to numeric conversion if
	       necessary.  Handles operator overloading.  Skips handling 'get' magic.

		       void    sv_dec_nomg(SV *const sv)

       sv_eq   Returns a boolean indicating whether the strings in the two SVs are identical.  Is
	       UTF-8 and 'use bytes' aware, handles get magic, and will coerce its args to
	       strings if necessary.

		       I32     sv_eq(SV* sv1, SV* sv2)

       sv_eq_flags
	       Returns a boolean indicating whether the strings in the two SVs are identical.  Is
	       UTF-8 and 'use bytes' aware and coerces its args to strings if necessary.  If the
	       flags include SV_GMAGIC, it handles get-magic, too.

		       I32     sv_eq_flags(SV* sv1, SV* sv2, const U32 flags)

       sv_force_normal_flags
	       Undo various types of fakery on an SV: if the PV is a shared string, make a
	       private copy; if we're a ref, stop refing; if we're a glob, downgrade to an xpvmg;
	       if we're a copy-on-write scalar, this is the on-write time when we do the copy,
	       and is also used locally.  If "SV_COW_DROP_PV" is set then a copy-on-write scalar
	       drops its PV buffer (if any) and becomes SvPOK_off rather than making a copy.
	       (Used where this scalar is about to be set to some other value.)  In addition, the
	       "flags" parameter gets passed to "sv_unref_flags()" when unreffing.
	       "sv_force_normal" calls this function with flags set to 0.

		       void    sv_force_normal_flags(SV *const sv,
						     const U32 flags)

       sv_free Decrement an SV's reference count, and if it drops to zero, call "sv_clear" to
	       invoke destructors and free up any memory used by the body; finally, deallocate
	       the SV's head itself.  Normally called via a wrapper macro "SvREFCNT_dec".

		       void    sv_free(SV *const sv)

       sv_gets Get a line from the filehandle and store it into the SV, optionally appending to
	       the currently-stored string.

		       char*   sv_gets(SV *const sv, PerlIO *const fp,
				       I32 append)

       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_inc  Auto-increment of the value in the SV, doing string to numeric conversion if
	       necessary.  Handles 'get' magic and operator overloading.

		       void    sv_inc(SV *const sv)

       sv_inc_nomg
	       Auto-increment of the value in the SV, doing string to numeric conversion if
	       necessary.  Handles operator overloading.  Skips handling 'get' magic.

		       void    sv_inc_nomg(SV *const sv)

       sv_insert
	       Inserts a string at the specified offset/length within the SV.  Similar to the
	       Perl substr() function.	Handles get magic.

		       void    sv_insert(SV *const bigstr, const STRLEN offset,
					 const STRLEN len,
					 const char *const little,
					 const STRLEN littlelen)

       sv_insert_flags
	       Same as "sv_insert", but the extra "flags" are passed to the "SvPV_force_flags"
	       that applies to "bigstr".

		       void    sv_insert_flags(SV *const bigstr,
					       const STRLEN offset,
					       const STRLEN len,
					       const char *const little,
					       const STRLEN littlelen,
					       const U32 flags)

       sv_isa  Returns a boolean indicating whether the SV is blessed into the specified class.
	       This does not check for subtypes; use "sv_derived_from" to verify an inheritance
	       relationship.

		       int     sv_isa(SV* sv, const char *const name)

       sv_isobject
	       Returns a boolean indicating whether the SV is an RV pointing to a blessed object.
	       If the SV is not an RV, or if the object is not blessed, then this will return
	       false.

		       int     sv_isobject(SV* sv)

       sv_len  Returns the length of the string in the SV.  Handles magic and type coercion.  See
	       also "SvCUR", which gives raw access to the xpv_cur slot.

		       STRLEN  sv_len(SV *const sv)

       sv_len_utf8
	       Returns the number of characters in the string in an SV, counting wide UTF-8 bytes
	       as a single character.  Handles magic and type coercion.

		       STRLEN  sv_len_utf8(SV *const sv)

       sv_magic
	       Adds magic to an SV.  First upgrades "sv" to type "SVt_PVMG" if necessary, then
	       adds a new magic item of type "how" to the head of the magic list.

	       See "sv_magicext" (which "sv_magic" now calls) for a description of the handling
	       of the "name" and "namlen" arguments.

	       You need to use "sv_magicext" to add magic to SvREADONLY SVs and also to add more
	       than one instance of the same 'how'.

		       void    sv_magic(SV *const sv, SV *const obj,
					const int how, const char *const name,
					const I32 namlen)

       sv_magicext
	       Adds magic to an SV, upgrading it if necessary.	Applies the supplied vtable and
	       returns a pointer to the magic added.

	       Note that "sv_magicext" will allow things that "sv_magic" will not.  In
	       particular, you can add magic to SvREADONLY SVs, and add more than one instance of
	       the same 'how'.

	       If "namlen" is greater than zero then a "savepvn" copy of "name" is stored, if
	       "namlen" is zero then "name" is stored as-is and - as another special case - if
	       "(name && namlen == HEf_SVKEY)" then "name" is assumed to contain an "SV*" and is
	       stored as-is with its REFCNT incremented.

	       (This is now used as a subroutine by "sv_magic".)

		       MAGIC * sv_magicext(SV *const sv, SV *const obj,
					   const int how,
					   const MGVTBL *const vtbl,
					   const char *const name,
					   const I32 namlen)

       sv_mortalcopy
	       Creates a new SV which is a copy of the original SV (using "sv_setsv").	The new
	       SV is marked as mortal.	It will be destroyed "soon", either by an explicit call
	       to FREETMPS, or by an implicit call at places such as statement boundaries.  See
	       also "sv_newmortal" and "sv_2mortal".

		       SV*     sv_mortalcopy(SV *const oldsv)

       sv_newmortal
	       Creates a new null SV which is mortal.  The reference count of the SV is set to 1.
	       It will be destroyed "soon", either by an explicit call to FREETMPS, or by an
	       implicit call at places such as statement boundaries.  See also "sv_mortalcopy"
	       and "sv_2mortal".

		       SV*     sv_newmortal()

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

		       SV*     sv_newref(SV *const sv)

       sv_pos_b2u
	       Converts the value pointed to by offsetp from a count of bytes from the start of
	       the string, to a count of the equivalent number of UTF-8 chars.	Handles magic and
	       type coercion.

		       void    sv_pos_b2u(SV *const sv, I32 *const offsetp)

       sv_pos_u2b
	       Converts the value pointed to by offsetp from a count of UTF-8 chars from the
	       start of the string, to a count of the equivalent number of bytes; if lenp is non-
	       zero, it does the same to lenp, but this time starting from the offset, rather
	       than from the start of the string.  Handles magic and type coercion.

	       Use "sv_pos_u2b_flags" in preference, which correctly handles strings longer than
	       2Gb.

		       void    sv_pos_u2b(SV *const sv, I32 *const offsetp,
					  I32 *const lenp)

       sv_pos_u2b_flags
	       Converts the value pointed to by offsetp from a count of UTF-8 chars from the
	       start of the string, to a count of the equivalent number of bytes; if lenp is non-
	       zero, it does the same to lenp, but this time starting from the offset, rather
	       than from the start of the string.  Handles type coercion.  flags is passed to
	       "SvPV_flags", and usually should be "SV_GMAGIC|SV_CONST_RETURN" to handle magic.

		       STRLEN  sv_pos_u2b_flags(SV *const sv, STRLEN uoffset,
						STRLEN *const lenp, U32 flags)

       sv_pvbyten_force
	       The backend for the "SvPVbytex_force" macro.  Always use the macro instead.

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

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

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

       sv_pvn_force_flags
	       Get a sensible string out of the SV somehow.  If "flags" has "SV_GMAGIC" bit set,
	       will "mg_get" on "sv" if appropriate, else not.	"sv_pvn_force" and
	       "sv_pvn_force_nomg" are implemented in terms of this function.  You normally want
	       to use the various wrapper macros instead: see "SvPV_force" and "SvPV_force_nomg"

		       char*   sv_pvn_force_flags(SV *const sv,
						  STRLEN *const lp,
						  const I32 flags)

       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_reftype
	       Returns a string describing what the SV is a reference to.

		       const char* sv_reftype(const SV *const sv, const int ob)

       sv_replace
	       Make the first argument a copy of the second, then delete the original.	The
	       target SV physically takes over ownership of the body of the source SV and
	       inherits its flags; however, the target keeps any magic it owns, and any magic in
	       the source is discarded.  Note that this is a rather specialist SV copying
	       operation; most of the time you'll want to use "sv_setsv" or one of its many macro
	       front-ends.

		       void    sv_replace(SV *const sv, SV *const nsv)

       sv_reset
	       Underlying implementation for the "reset" Perl function.  Note that the perl-level
	       function is vaguely deprecated.

		       void    sv_reset(const char* s, HV *const stash)

       sv_rvweaken
	       Weaken a reference: set the "SvWEAKREF" flag on this RV; give the referred-to SV
	       "PERL_MAGIC_backref" magic if it hasn't already; and push a back-reference to this
	       RV onto the array of backreferences associated with that magic.	If the RV is
	       magical, set magic will be called after the RV is cleared.

		       SV*     sv_rvweaken(SV *const sv)

       sv_setiv
	       Copies an integer into the given SV, upgrading first if necessary.  Does not
	       handle 'set' magic.  See also "sv_setiv_mg".

		       void    sv_setiv(SV *const sv, const IV num)

       sv_setiv_mg
	       Like "sv_setiv", but also handles 'set' magic.

		       void    sv_setiv_mg(SV *const sv, const IV i)

       sv_setnv
	       Copies a double into the given SV, upgrading first if necessary.  Does not handle
	       'set' magic.  See also "sv_setnv_mg".

		       void    sv_setnv(SV *const sv, const NV num)

       sv_setnv_mg
	       Like "sv_setnv", but also handles 'set' magic.

		       void    sv_setnv_mg(SV *const sv, const NV num)

       sv_setpv
	       Copies a string into an SV.  The string must be null-terminated.  Does not handle
	       'set' magic.  See "sv_setpv_mg".

		       void    sv_setpv(SV *const sv, const char *const ptr)

       sv_setpvf
	       Works like "sv_catpvf" but copies the text into the SV instead of appending it.
	       Does not handle 'set' magic.  See "sv_setpvf_mg".

		       void    sv_setpvf(SV *const sv, const char *const pat,
					 ...)

       sv_setpvf_mg
	       Like "sv_setpvf", but also handles 'set' magic.

		       void    sv_setpvf_mg(SV *const sv,
					    const char *const pat, ...)

       sv_setpviv
	       Copies an integer into the given SV, also updating its string value.  Does not
	       handle 'set' magic.  See "sv_setpviv_mg".

		       void    sv_setpviv(SV *const sv, const IV num)

       sv_setpviv_mg
	       Like "sv_setpviv", but also handles 'set' magic.

		       void    sv_setpviv_mg(SV *const sv, const IV iv)

       sv_setpvn
	       Copies a string into an SV.  The "len" parameter indicates the number of bytes to
	       be copied.  If the "ptr" argument is NULL the SV will become undefined.	Does not
	       handle 'set' magic.  See "sv_setpvn_mg".

		       void    sv_setpvn(SV *const sv, const char *const ptr,
					 const STRLEN len)

       sv_setpvn_mg
	       Like "sv_setpvn", but also handles 'set' magic.

		       void    sv_setpvn_mg(SV *const sv,
					    const char *const ptr,
					    const STRLEN len)

       sv_setpvs
	       Like "sv_setpvn", but takes a literal string instead of a string/length pair.

		       void    sv_setpvs(SV* sv, const char* s)

       sv_setpvs_mg
	       Like "sv_setpvn_mg", but takes a literal string instead of a string/length pair.

		       void    sv_setpvs_mg(SV* sv, const char* s)

       sv_setpv_mg
	       Like "sv_setpv", but also handles 'set' magic.

		       void    sv_setpv_mg(SV *const sv, const char *const ptr)

       sv_setref_iv
	       Copies an integer into a new SV, optionally blessing the SV.  The "rv" argument
	       will be upgraded to an RV.  That RV will be modified to point to the new SV.  The
	       "classname" argument indicates the package for the blessing.  Set "classname" to
	       "NULL" to avoid the blessing.  The new SV will have a reference count of 1, and
	       the RV will be returned.

		       SV*     sv_setref_iv(SV *const rv,
					    const char *const classname,
					    const IV iv)

       sv_setref_nv
	       Copies a double into a new SV, optionally blessing the SV.  The "rv" argument will
	       be upgraded to an RV.  That RV will be modified to point to the new SV.	The
	       "classname" argument indicates the package for the blessing.  Set "classname" to
	       "NULL" to avoid the blessing.  The new SV will have a reference count of 1, and
	       the RV will be returned.

		       SV*     sv_setref_nv(SV *const rv,
					    const char *const classname,
					    const NV nv)

       sv_setref_pv
	       Copies a pointer into a new SV, optionally blessing the SV.  The "rv" argument
	       will be upgraded to an RV.  That RV will be modified to point to the new SV.  If
	       the "pv" argument is NULL then "PL_sv_undef" will be placed into the SV.  The
	       "classname" argument indicates the package for the blessing.  Set "classname" to
	       "NULL" to avoid the blessing.  The new SV will have a reference count of 1, and
	       the RV will be returned.

	       Do not use with other Perl types such as HV, AV, SV, CV, because those objects
	       will become corrupted by the pointer copy process.

	       Note that "sv_setref_pvn" copies the string while this copies the pointer.

		       SV*     sv_setref_pv(SV *const rv,
					    const char *const classname,
					    void *const pv)

       sv_setref_pvn
	       Copies a string into a new SV, optionally blessing the SV.  The length of the
	       string must be specified with "n".  The "rv" argument will be upgraded to an RV.
	       That RV will be modified to point to the new SV.  The "classname" argument
	       indicates the package for the blessing.	Set "classname" to "NULL" to avoid the
	       blessing.  The new SV will have a reference count of 1, and the RV will be
	       returned.

	       Note that "sv_setref_pv" copies the pointer while this copies the string.

		       SV*     sv_setref_pvn(SV *const rv,
					     const char *const classname,
					     const char *const pv,
					     const STRLEN n)

       sv_setref_pvs
	       Like "sv_setref_pvn", but takes a literal string instead of a string/length pair.

		       SV *    sv_setref_pvs(const char* s)

       sv_setref_uv
	       Copies an unsigned integer into a new SV, optionally blessing the SV.  The "rv"
	       argument will be upgraded to an RV.  That RV will be modified to point to the new
	       SV.  The "classname" argument indicates the package for the blessing.  Set
	       "classname" to "NULL" to avoid the blessing.  The new SV will have a reference
	       count of 1, and the RV will be returned.

		       SV*     sv_setref_uv(SV *const rv,
					    const char *const classname,
					    const UV uv)

       sv_setsv
	       Copies the contents of the source SV "ssv" into the destination SV "dsv".  The
	       source SV may be destroyed if it is mortal, so don't use this function if the
	       source SV needs to be reused.  Does not handle 'set' magic.  Loosely speaking, it
	       performs a copy-by-value, obliterating any previous content of the destination.

	       You probably want to use one of the assortment of wrappers, such as "SvSetSV",
	       "SvSetSV_nosteal", "SvSetMagicSV" and "SvSetMagicSV_nosteal".

		       void    sv_setsv(SV *dstr, SV *sstr)

       sv_setsv_flags
	       Copies the contents of the source SV "ssv" into the destination SV "dsv".  The
	       source SV may be destroyed if it is mortal, so don't use this function if the
	       source SV needs to be reused.  Does not handle 'set' magic.  Loosely speaking, it
	       performs a copy-by-value, obliterating any previous content of the destination.
	       If the "flags" parameter has the "SV_GMAGIC" bit set, will "mg_get" on "ssv" if
	       appropriate, else not.  If the "flags" parameter has the "NOSTEAL" bit set then
	       the buffers of temps will not be stolen.  <sv_setsv> and "sv_setsv_nomg" are
	       implemented in terms of this function.

	       You probably want to use one of the assortment of wrappers, such as "SvSetSV",
	       "SvSetSV_nosteal", "SvSetMagicSV" and "SvSetMagicSV_nosteal".

	       This is the primary function for copying scalars, and most other copy-ish
	       functions and macros use this underneath.

		       void    sv_setsv_flags(SV *dstr, SV *sstr,
					      const I32 flags)

       sv_setsv_mg
	       Like "sv_setsv", but also handles 'set' magic.

		       void    sv_setsv_mg(SV *const dstr, SV *const sstr)

       sv_setuv
	       Copies an unsigned integer into the given SV, upgrading first if necessary.  Does
	       not handle 'set' magic.	See also "sv_setuv_mg".

		       void    sv_setuv(SV *const sv, const UV num)

       sv_setuv_mg
	       Like "sv_setuv", but also handles 'set' magic.

		       void    sv_setuv_mg(SV *const sv, const UV u)

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

		       bool    sv_tainted(SV *const 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_unmagic
	       Removes all magic of type "type" from an SV.

		       int     sv_unmagic(SV *const sv, const int type)

       sv_unmagicext
	       Removes all magic of type "type" with the specified "vtbl" from an SV.

		       int     sv_unmagicext(SV *const sv, const int type,
					     MGVTBL *vtbl)

       sv_unref_flags
	       Unsets the RV status of the SV, and decrements the reference count of whatever was
	       being referenced by the RV.  This can almost be thought of as a reversal of
	       "newSVrv".  The "cflags" argument can contain "SV_IMMEDIATE_UNREF" to force the
	       reference count to be decremented (otherwise the decrementing is conditional on
	       the reference count being different from one or the reference being a readonly
	       SV).  See "SvROK_off".

		       void    sv_unref_flags(SV *const ref, const U32 flags)

       sv_untaint
	       Untaint an SV.  Use "SvTAINTED_off" instead.

		       void    sv_untaint(SV *const sv)

       sv_upgrade
	       Upgrade an SV to a more complex form.  Generally adds a new body type to the SV,
	       then copies across as much information as possible from the old body.  It croaks
	       if the SV is already in a more complex form than requested.  You generally want to
	       use the "SvUPGRADE" macro wrapper, which checks the type before calling
	       "sv_upgrade", and hence does not croak.	See also "svtype".

		       void    sv_upgrade(SV *const sv, svtype new_type)

       sv_usepvn_flags
	       Tells an SV to use "ptr" to find its string value.  Normally the string is stored
	       inside the SV but sv_usepvn allows the SV to use an outside string.  The "ptr"
	       should point to memory that was allocated by "malloc".  It must be the start of a
	       mallocked block of memory, and not a pointer to the middle of it.  The string
	       length, "len", must be supplied.  By default this function will realloc (i.e.
	       move) the memory pointed to by "ptr", so that pointer should not be freed or used
	       by the programmer after giving it to sv_usepvn, and neither should any pointers
	       from "behind" that pointer (e.g. ptr + 1) be used.

	       If "flags" & SV_SMAGIC is true, will call SvSETMAGIC.  If "flags" &
	       SV_HAS_TRAILING_NUL is true, then "ptr[len]" must be NUL, and the realloc will be
	       skipped (i.e. the buffer is actually at least 1 byte longer than "len", and
	       already meets the requirements for storing in "SvPVX").

		       void    sv_usepvn_flags(SV *const sv, char* ptr,
					       const STRLEN len,
					       const U32 flags)

       sv_utf8_decode
	       If the PV of the SV is an octet sequence in UTF-8 and contains a multiple-byte
	       character, the "SvUTF8" flag is turned on so that it looks like a character.  If
	       the PV contains only single-byte characters, the "SvUTF8" flag stays off.  Scans
	       PV for validity and returns false if the PV is invalid UTF-8.

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

		       bool    sv_utf8_decode(SV *const sv)

       sv_utf8_downgrade
	       Attempts to convert the PV of an SV from characters to bytes.  If the PV contains
	       a character that cannot fit in a byte, this conversion will fail; in this case,
	       either returns false or, if "fail_ok" is not true, croaks.

	       This is not as a general purpose Unicode to byte encoding interface: use the
	       Encode extension for that.

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

		       bool    sv_utf8_downgrade(SV *const sv,
						 const bool fail_ok)

       sv_utf8_encode
	       Converts the PV of an SV to UTF-8, but then turns the "SvUTF8" flag off so that it
	       looks like octets again.

		       void    sv_utf8_encode(SV *const sv)

       sv_utf8_upgrade
	       Converts the PV of an SV to its UTF-8-encoded form.  Forces the SV to string form
	       if it is not already.  Will "mg_get" on "sv" if appropriate.  Always sets the
	       SvUTF8 flag to avoid future validity checks even if the whole string is the same
	       in UTF-8 as not.  Returns the number of bytes in the converted string

	       This is not as a general purpose byte encoding to Unicode interface: use the
	       Encode extension for that.

		       STRLEN  sv_utf8_upgrade(SV *sv)

       sv_utf8_upgrade_flags
	       Converts the PV of an SV to its UTF-8-encoded form.  Forces the SV to string form
	       if it is not already.  Always sets the SvUTF8 flag to avoid future validity checks
	       even if all the bytes are invariant in UTF-8.  If "flags" has "SV_GMAGIC" bit set,
	       will "mg_get" on "sv" if appropriate, else not.	Returns the number of bytes in
	       the converted string "sv_utf8_upgrade" and "sv_utf8_upgrade_nomg" are implemented
	       in terms of this function.

	       This is not as a general purpose byte encoding to Unicode interface: use the
	       Encode extension for that.

		       STRLEN  sv_utf8_upgrade_flags(SV *const sv,
						     const I32 flags)

       sv_utf8_upgrade_nomg
	       Like sv_utf8_upgrade, but doesn't do magic on "sv".

		       STRLEN  sv_utf8_upgrade_nomg(SV *sv)

       sv_vcatpvf
	       Processes its arguments like "vsprintf" and appends the formatted output to an SV.
	       Does not handle 'set' magic.  See "sv_vcatpvf_mg".

	       Usually used via its frontend "sv_catpvf".

		       void    sv_vcatpvf(SV *const sv, const char *const pat,
					  va_list *const args)

       sv_vcatpvfn
	       Processes its arguments like "vsprintf" and appends the formatted output to an SV.
	       Uses an array of SVs if the C style variable argument list is missing (NULL).
	       When running with taint checks enabled, indicates via "maybe_tainted" if results
	       are untrustworthy (often due to the use of locales).

	       Usually used via one of its frontends "sv_vcatpvf" and "sv_vcatpvf_mg".

		       void    sv_vcatpvfn(SV *const sv, const char *const pat,
					   const STRLEN patlen,
					   va_list *const args,
					   SV **const svargs, const I32 svmax,
					   bool *const maybe_tainted)

       sv_vcatpvf_mg
	       Like "sv_vcatpvf", but also handles 'set' magic.

	       Usually used via its frontend "sv_catpvf_mg".

		       void    sv_vcatpvf_mg(SV *const sv,
					     const char *const pat,
					     va_list *const args)

       sv_vsetpvf
	       Works like "sv_vcatpvf" but copies the text into the SV instead of appending it.
	       Does not handle 'set' magic.  See "sv_vsetpvf_mg".

	       Usually used via its frontend "sv_setpvf".

		       void    sv_vsetpvf(SV *const sv, const char *const pat,
					  va_list *const args)

       sv_vsetpvfn
	       Works like "sv_vcatpvfn" but copies the text into the SV instead of appending it.

	       Usually used via one of its frontends "sv_vsetpvf" and "sv_vsetpvf_mg".

		       void    sv_vsetpvfn(SV *const sv, const char *const pat,
					   const STRLEN patlen,
					   va_list *const args,
					   SV **const svargs, const I32 svmax,
					   bool *const maybe_tainted)

       sv_vsetpvf_mg
	       Like "sv_vsetpvf", but also handles 'set' magic.

	       Usually used via its frontend "sv_setpvf_mg".

		       void    sv_vsetpvf_mg(SV *const sv,
					     const char *const pat,
					     va_list *const args)

Unicode Support
       bytes_cmp_utf8
	       Compares the sequence of characters (stored as octets) in "b", "blen" with the
	       sequence of characters (stored as UTF-8) in "u", "ulen". Returns 0 if they are
	       equal, -1 or -2 if the first string is less than the second string, +1 or +2 if
	       the first string is greater than the second string.

	       -1 or +1 is returned if the shorter string was identical to the start of the
	       longer string. -2 or +2 is returned if the was a difference between characters
	       within the strings.

		       int     bytes_cmp_utf8(const U8 *b, STRLEN blen,
					      const U8 *u, STRLEN ulen)

       bytes_from_utf8
	       Converts a string "s" of length "len" from UTF-8 into native byte encoding.
	       Unlike "utf8_to_bytes" but like "bytes_to_utf8", returns a pointer to the newly-
	       created string, and updates "len" to contain the new length.  Returns the original
	       string if no conversion occurs, "len" is unchanged. Do nothing if "is_utf8" points
	       to 0. Sets "is_utf8" to 0 if "s" is converted or consisted entirely of characters
	       that are invariant in utf8 (i.e., US-ASCII on non-EBCDIC machines).

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

		       U8*     bytes_from_utf8(const U8 *s, STRLEN *len,
					       bool *is_utf8)

       bytes_to_utf8
	       Converts a string "s" of length "len" bytes from the native encoding into UTF-8.
	       Returns a pointer to the newly-created string, and sets "len" to reflect the new
	       length in bytes.

	       A NUL character will be written after the end of the string.

	       If you want to convert to UTF-8 from encodings other than the native (Latin1 or
	       EBCDIC), see "sv_recode_to_utf8"().

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

		       U8*     bytes_to_utf8(const U8 *s, STRLEN *len)

       foldEQ_utf8
	       Returns true if the leading portions of the strings "s1" and "s2" (either or both
	       of which may be in UTF-8) are the same case-insensitively; false otherwise.  How
	       far into the strings to compare is determined by other input parameters.

	       If "u1" is true, the string "s1" is assumed to be in UTF-8-encoded Unicode;
	       otherwise it is assumed to be in native 8-bit encoding.	Correspondingly for "u2"
	       with respect to "s2".

	       If the byte length "l1" is non-zero, it says how far into "s1" to check for fold
	       equality.  In other words, "s1"+"l1" will be used as a goal to reach.  The scan
	       will not be considered to be a match unless the goal is reached, and scanning
	       won't continue past that goal.  Correspondingly for "l2" with respect to "s2".

	       If "pe1" is non-NULL and the pointer it points to is not NULL, that pointer is
	       considered an end pointer beyond which scanning of "s1" will not continue under
	       any circumstances.  This means that if both "l1" and "pe1" are specified, and
	       "pe1" is less than "s1"+"l1", the match will never be successful because it can
	       never get as far as its goal (and in fact is asserted against).	Correspondingly
	       for "pe2" with respect to "s2".

	       At least one of "s1" and "s2" must have a goal (at least one of "l1" and "l2" must
	       be non-zero), and if both do, both have to be reached for a successful match.
	       Also, if the fold of a character is multiple characters, all of them must be
	       matched (see tr21 reference below for 'folding').

	       Upon a successful match, if "pe1" is non-NULL, it will be set to point to the
	       beginning of the next character of "s1" beyond what was matched.  Correspondingly
	       for "pe2" and "s2".

	       For case-insensitiveness, the "casefolding" of Unicode is used instead of
	       upper/lowercasing both the characters, see
	       <http://www.unicode.org/unicode/reports/tr21/> (Case Mappings).

		       I32     foldEQ_utf8(const char *s1, char **pe1, UV l1,
					   bool u1, const char *s2, char **pe2,
					   UV l2, bool u2)

       is_ascii_string
	       Returns true if the first "len" bytes of the string "s" are the same whether or
	       not the string is encoded in UTF-8 (or UTF-EBCDIC on EBCDIC machines).  That is,
	       if they are invariant.  On ASCII-ish machines, only ASCII characters fit this
	       definition, hence the function's name.

	       If "len" is 0, it will be calculated using strlen(s).

	       See also "is_utf8_string"(), "is_utf8_string_loclen"(), and
	       "is_utf8_string_loc"().

		       bool    is_ascii_string(const U8 *s, STRLEN len)

       is_utf8_char
	       DEPRECATED!

	       Tests if some arbitrary number of bytes begins in a valid UTF-8 character.  Note
	       that an INVARIANT (i.e. ASCII on non-EBCDIC machines) character is a valid UTF-8
	       character.  The actual number of bytes in the UTF-8 character will be returned if
	       it is valid, otherwise 0.

	       This function is deprecated due to the possibility that malformed input could
	       cause reading beyond the end of the input buffer.  Use "is_utf8_char_buf" instead.

		       STRLEN  is_utf8_char(const U8 *s)

       is_utf8_char_buf
	       Returns the number of bytes that comprise the first UTF-8 encoded character in
	       buffer "buf".  "buf_end" should point to one position beyond the end of the
	       buffer.	0 is returned if "buf" does not point to a complete, valid UTF-8 encoded
	       character.

	       Note that an INVARIANT character (i.e. ASCII on non-EBCDIC machines) is a valid
	       UTF-8 character.

		       STRLEN  is_utf8_char_buf(const U8 *buf,
						const U8 *buf_end)

       is_utf8_string
	       Returns true if the first "len" bytes of string "s" form a valid UTF-8 string,
	       false otherwise.  If "len" is 0, it will be calculated using strlen(s) (which
	       means if you use this option, that "s" has to have a terminating NUL byte).  Note
	       that all characters being ASCII constitute 'a valid UTF-8 string'.

	       See also "is_ascii_string"(), "is_utf8_string_loclen"(), and
	       "is_utf8_string_loc"().

		       bool    is_utf8_string(const U8 *s, STRLEN len)

       is_utf8_string_loc
	       Like "is_utf8_string" but stores the location of the failure (in the case of
	       "utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success")
	       in the "ep".

	       See also "is_utf8_string_loclen"() and "is_utf8_string"().

		       bool    is_utf8_string_loc(const U8 *s, STRLEN len,
						  const U8 **p)

       is_utf8_string_loclen
	       Like "is_utf8_string"() but stores the location of the failure (in the case of
	       "utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success")
	       in the "ep", and the number of UTF-8 encoded characters in the "el".

	       See also "is_utf8_string_loc"() and "is_utf8_string"().

		       bool    is_utf8_string_loclen(const U8 *s, STRLEN len,
						     const U8 **ep, STRLEN *el)

       pv_uni_display
	       Build to the scalar "dsv" a displayable version of the string "spv", length "len",
	       the displayable version being at most "pvlim" bytes long (if longer, the rest is
	       truncated and "..." will be appended).

	       The "flags" argument can have UNI_DISPLAY_ISPRINT set to display isPRINT()able
	       characters as themselves, UNI_DISPLAY_BACKSLASH to display the \\[nrfta\\] as the
	       backslashed versions (like '\n') (UNI_DISPLAY_BACKSLASH is preferred over
	       UNI_DISPLAY_ISPRINT for \\).  UNI_DISPLAY_QQ (and its alias UNI_DISPLAY_REGEX)
	       have both UNI_DISPLAY_BACKSLASH and UNI_DISPLAY_ISPRINT turned on.

	       The pointer to the PV of the "dsv" is returned.

		       char*   pv_uni_display(SV *dsv, const U8 *spv,
					      STRLEN len, STRLEN pvlim,
					      UV flags)

       sv_cat_decode
	       The encoding is assumed to be an Encode object, the PV of the ssv is assumed to be
	       octets in that encoding and decoding the input starts from the position which (PV
	       + *offset) pointed to.  The dsv will be concatenated the decoded UTF-8 string from
	       ssv.  Decoding will terminate when the string tstr appears in decoding output or
	       the input ends on the PV of the ssv.  The value which the offset points will be
	       modified to the last input position on the ssv.

	       Returns TRUE if the terminator was found, else returns FALSE.

		       bool    sv_cat_decode(SV* dsv, SV *encoding, SV *ssv,
					     int *offset, char* tstr, int tlen)

       sv_recode_to_utf8
	       The encoding is assumed to be an Encode object, on entry the PV of the sv is
	       assumed to be octets in that encoding, and the sv will be converted into Unicode
	       (and UTF-8).

	       If the sv already is UTF-8 (or if it is not POK), or if the encoding is not a
	       reference, nothing is done to the sv.  If the encoding is not an "Encode::XS"
	       Encoding object, bad things will happen.  (See lib/encoding.pm and Encode.)

	       The PV of the sv is returned.

		       char*   sv_recode_to_utf8(SV* sv, SV *encoding)

       sv_uni_display
	       Build to the scalar "dsv" a displayable version of the scalar "sv", the
	       displayable version being at most "pvlim" bytes long (if longer, the rest is
	       truncated and "..." will be appended).

	       The "flags" argument is as in "pv_uni_display"().

	       The pointer to the PV of the "dsv" is returned.

		       char*   sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim,
					      UV flags)

       to_utf8_case
	       The "p" contains the pointer to the UTF-8 string encoding the character that is
	       being converted.  This routine assumes that the character at "p" is well-formed.

	       The "ustrp" is a pointer to the character buffer to put the conversion result to.
	       The "lenp" is a pointer to the length of the result.

	       The "swashp" is a pointer to the swash to use.

	       Both the special and normal mappings are stored in lib/unicore/To/Foo.pl, and
	       loaded by SWASHNEW, using lib/utf8_heavy.pl.  The "special" (usually, but not
	       always, a multicharacter mapping), is tried first.

	       The "special" is a string like "utf8::ToSpecLower", which means the hash
	       %utf8::ToSpecLower.  The access to the hash is through Perl_to_utf8_case().

	       The "normal" is a string like "ToLower" which means the swash %utf8::ToLower.

		       UV      to_utf8_case(const U8 *p, U8* ustrp,
					    STRLEN *lenp, SV **swashp,
					    const char *normal,
					    const char *special)

       to_utf8_fold
	       Convert the UTF-8 encoded character at "p" to its foldcase version and store that
	       in UTF-8 in "ustrp" and its length in bytes in "lenp".  Note that the "ustrp"
	       needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the foldcase version may be
	       longer than the original character (up to three characters).

	       The first character of the foldcased version is returned (but note, as explained
	       above, that there may be more.)

	       The character at "p" is assumed by this routine to be well-formed.

		       UV      to_utf8_fold(const U8 *p, U8* ustrp,
					    STRLEN *lenp)

       to_utf8_lower
	       Convert the UTF-8 encoded character at "p" to its lowercase version and store that
	       in UTF-8 in ustrp and its length in bytes in "lenp".  Note that the "ustrp" needs
	       to be at least UTF8_MAXBYTES_CASE+1 bytes since the lowercase version may be
	       longer than the original character.

	       The first character of the lowercased version is returned (but note, as explained
	       above, that there may be more.)

	       The character at "p" is assumed by this routine to be well-formed.

		       UV      to_utf8_lower(const U8 *p, U8* ustrp,
					     STRLEN *lenp)

       to_utf8_title
	       Convert the UTF-8 encoded character at "p" to its titlecase version and store that
	       in UTF-8 in "ustrp" and its length in bytes in "lenp".  Note that the "ustrp"
	       needs to be at least UTF8_MAXBYTES_CASE+1 bytes since the titlecase version may be
	       longer than the original character.

	       The first character of the titlecased version is returned (but note, as explained
	       above, that there may be more.)

	       The character at "p" is assumed by this routine to be well-formed.

		       UV      to_utf8_title(const U8 *p, U8* ustrp,
					     STRLEN *lenp)

       to_utf8_upper
	       Convert the UTF-8 encoded character at "p" to its uppercase version and store that
	       in UTF-8 in "ustrp" and its length in bytes in "lenp".  Note that the ustrp needs
	       to be at least UTF8_MAXBYTES_CASE+1 bytes since the uppercase version may be
	       longer than the original character.

	       The first character of the uppercased version is returned (but note, as explained
	       above, that there may be more.)

	       The character at "p" is assumed by this routine to be well-formed.

		       UV      to_utf8_upper(const U8 *p, U8* ustrp,
					     STRLEN *lenp)

       utf8n_to_uvchr
	       Returns the native character value 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.

	       "length" and "flags" are the same as "utf8n_to_uvuni"().

		       UV      utf8n_to_uvchr(const U8 *s, STRLEN curlen,
					      STRLEN *retlen, U32 flags)

       utf8n_to_uvuni
	       Bottom level UTF-8 decode routine.  Returns the code point value of the first
	       character in the string "s", which is assumed to be in UTF-8 (or UTF-EBCDIC)
	       encoding, and no longer than "curlen" bytes; *retlen (if "retlen" isn't NULL) will
	       be set to the length, in bytes, of that character.

	       The value of "flags" determines the behavior when "s" does not point to a well-
	       formed UTF-8 character.	If "flags" is 0, when a malformation is found, zero is
	       returned and *retlen is set so that ("s" + *retlen) is the next possible position
	       in "s" that could begin a non-malformed character.  Also, if UTF-8 warnings
	       haven't been lexically disabled, a warning is raised.

	       Various ALLOW flags can be set in "flags" to allow (and not warn on) individual
	       types of malformations, such as the sequence being overlong (that is, when there
	       is a shorter sequence that can express the same code point; overlong sequences are
	       expressly forbidden in the UTF-8 standard due to potential security issues).
	       Another malformation example is the first byte of a character not being a legal
	       first byte.  See utf8.h for the list of such flags.  For allowed 0 length strings,
	       this function returns 0; for allowed overlong sequences, the computed code point
	       is returned; for all other allowed malformations, the Unicode REPLACEMENT
	       CHARACTER is returned, as these have no determinable reasonable value.

	       The UTF8_CHECK_ONLY flag overrides the behavior when a non-allowed (by other
	       flags) malformation is found.  If this flag is set, the routine assumes that the
	       caller will raise a warning, and this function will silently just set "retlen" to
	       "-1" and return zero.

	       Certain code points are considered problematic.	These are Unicode surrogates,
	       Unicode non-characters, and code points above the Unicode maximum of 0x10FFFF.  By
	       default these are considered regular code points, but certain situations warrant
	       special handling for them.  If "flags" contains UTF8_DISALLOW_ILLEGAL_INTERCHANGE,
	       all three classes are treated as malformations and handled as such.  The flags
	       UTF8_DISALLOW_SURROGATE, UTF8_DISALLOW_NONCHAR, and UTF8_DISALLOW_SUPER (meaning
	       above the legal Unicode maximum) can be set to disallow these categories
	       individually.

	       The flags UTF8_WARN_ILLEGAL_INTERCHANGE, UTF8_WARN_SURROGATE, UTF8_WARN_NONCHAR,
	       and UTF8_WARN_SUPER will cause warning messages to be raised for their respective
	       categories, but otherwise the code points are considered valid (not
	       malformations).	To get a category to both be treated as a malformation and raise
	       a warning, specify both the WARN and DISALLOW flags.  (But note that warnings are
	       not raised if lexically disabled nor if UTF8_CHECK_ONLY is also specified.)

	       Very large code points (above 0x7FFF_FFFF) are considered more problematic than
	       the others that are above the Unicode legal maximum.  There are several reasons:
	       they requre at least 32 bits to represent them on ASCII platforms, are not
	       representable at all on EBCDIC platforms, and the original UTF-8 specification
	       never went above this number (the current 0x10FFFF limit was imposed later).  (The
	       smaller ones, those that fit into 32 bits, are representable by a UV on ASCII
	       platforms, but not by an IV, which means that the number of operations that can be
	       performed on them is quite restricted.)	The UTF-8 encoding on ASCII platforms for
	       these large code points begins with a byte containing 0xFE or 0xFF.  The
	       UTF8_DISALLOW_FE_FF flag will cause them to be treated as malformations, while
	       allowing smaller above-Unicode code points.  (Of course UTF8_DISALLOW_SUPER will
	       treat all above-Unicode code points, including these, as malformations.)
	       Similarly, UTF8_WARN_FE_FF acts just like the other WARN flags, but applies just
	       to these code points.

	       All other code points corresponding to Unicode characters, including private use
	       and those yet to be assigned, are never considered malformed and never warn.

	       Most code should use "utf8_to_uvchr_buf"() rather than call this directly.

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

       utf8_distance
	       Returns the number of UTF-8 characters between the UTF-8 pointers "a" and "b".

	       WARNING: use only if you *know* that the pointers point inside the same UTF-8
	       buffer.

		       IV      utf8_distance(const U8 *a, const U8 *b)

       utf8_hop
	       Return the UTF-8 pointer "s" displaced by "off" characters, either forward or
	       backward.

	       WARNING: do not use the following unless you *know* "off" is within the UTF-8 data
	       pointed to by "s" *and* that on entry "s" is aligned on the first byte of
	       character or just after the last byte of a character.

		       U8*     utf8_hop(const U8 *s, I32 off)

       utf8_length
	       Return the length of the UTF-8 char encoded string "s" in characters.  Stops at
	       "e" (inclusive).  If "e < s" or if the scan would end up past "e", croaks.

		       STRLEN  utf8_length(const U8* s, const U8 *e)

       utf8_to_bytes
	       Converts a string "s" of length "len" from UTF-8 into native byte encoding.
	       Unlike "bytes_to_utf8", this over-writes the original string, and updates "len" to
	       contain the new length.	Returns zero on failure, setting "len" to -1.

	       If you need a copy of the string, see "bytes_from_utf8".

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

		       U8*     utf8_to_bytes(U8 *s, STRLEN *len)

       utf8_to_uvchr
	       DEPRECATED!

	       Returns the native 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 why this
	       function is deprecated.	Use "utf8_to_uvchr_buf" instead.

	       If "s" points to one of the detected malformations, and UTF8 warnings are enabled,
	       zero is returned and *retlen is set (if "retlen" isn't NULL) to -1.  If those
	       warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT
	       CHARACTER, if not) is silently returned, and *retlen is set (if "retlen" isn't
	       NULL) so that ("s" + *retlen) is the next possible position in "s" that could
	       begin a non-malformed character.  See "utf8n_to_uvuni" for details on when the
	       REPLACEMENT CHARACTER is returned.

		       UV      utf8_to_uvchr(const U8 *s, STRLEN *retlen)

       utf8_to_uvchr_buf
	       Returns the native code point of the first character in the string "s" which is
	       assumed to be in UTF-8 encoding; "send" points to 1 beyond the end of "s".
	       *retlen will be set to the length, in bytes, of that character.

	       If "s" does not point to a well-formed UTF-8 character and UTF8 warnings are
	       enabled, zero is returned and *retlen is set (if "retlen" isn't NULL) to -1.  If
	       those warnings are off, the computed value if well-defined (or the Unicode
	       REPLACEMENT CHARACTER, if not) is silently returned, and *retlen is set (if
	       "retlen" isn't NULL) so that ("s" + *retlen) is the next possible position in "s"
	       that could begin a non-malformed character.  See "utf8n_to_uvuni" for details on
	       when the REPLACEMENT CHARACTER is returned.

		       UV      utf8_to_uvchr_buf(const U8 *s, const U8 *send,
						 STRLEN *retlen)

       utf8_to_uvuni
	       DEPRECATED!

	       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.

	       This function should only be used when the returned UV is considered an index into
	       the Unicode semantic tables (e.g. swashes).

	       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 why this
	       function is deprecated.	Use "utf8_to_uvuni_buf" instead.

	       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_uvuni" for details on
	       when the REPLACEMENT CHARACTER is returned.

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

       utf8_to_uvuni_buf
	       Returns the Unicode code point of the first character in the string "s" which is
	       assumed to be in UTF-8 encoding; "send" points to 1 beyond the end of "s".
	       "retlen" will be set to the length, in bytes, of that character.

	       This function should only be used when the returned UV is considered an index into
	       the Unicode semantic tables (e.g. swashes).

	       If "s" does not point to a well-formed UTF-8 character and UTF8 warnings are
	       enabled, zero is returned and *retlen is set (if "retlen" isn't NULL) to -1.  If
	       those warnings are off, the computed value if well-defined (or the Unicode
	       REPLACEMENT CHARACTER, if not) is silently returned, and *retlen is set (if
	       "retlen" isn't NULL) so that ("s" + *retlen) is the next possible position in "s"
	       that could begin a non-malformed character.  See "utf8n_to_uvuni" for details on
	       when the REPLACEMENT CHARACTER is returned.

		       UV      utf8_to_uvuni_buf(const U8 *s, const U8 *send,
						 STRLEN *retlen)

       uvchr_to_utf8
	       Adds the UTF-8 representation of the Native code point "uv" to the end of the
	       string "d"; "d" should have at least "UTF8_MAXBYTES+1" free bytes available. The
	       return value is the pointer to the byte after the end of the new character. In
	       other words,

		   d = uvchr_to_utf8(d, uv);

	       is the recommended wide native character-aware way of saying

		   *(d++) = uv;

		       U8*     uvchr_to_utf8(U8 *d, UV uv)

       uvuni_to_utf8_flags
	       Adds the UTF-8 representation of the code point "uv" to the end of the string "d";
	       "d" should have at least "UTF8_MAXBYTES+1" free bytes available. The return value
	       is the pointer to the byte after the end of the new character. In other words,

		   d = uvuni_to_utf8_flags(d, uv, flags);

	       or, in most cases,

		   d = uvuni_to_utf8(d, uv);

	       (which is equivalent to)

		   d = uvuni_to_utf8_flags(d, uv, 0);

	       This is the recommended Unicode-aware way of saying

		   *(d++) = uv;

	       This function will convert to UTF-8 (and not warn) even code points that aren't
	       legal Unicode or are problematic, unless "flags" contains one or more of the
	       following flags:

	       If "uv" is a Unicode surrogate code point and UNICODE_WARN_SURROGATE is set, the
	       function will raise a warning, provided UTF8 warnings are enabled.  If instead
	       UNICODE_DISALLOW_SURROGATE is set, the function will fail and return NULL.  If
	       both flags are set, the function will both warn and return NULL.

	       The UNICODE_WARN_NONCHAR and UNICODE_DISALLOW_NONCHAR flags correspondingly affect
	       how the function handles a Unicode non-character.  And, likewise for the
	       UNICODE_WARN_SUPER and UNICODE_DISALLOW_SUPER flags, and code points that are
	       above the Unicode maximum of 0x10FFFF.  Code points above 0x7FFF_FFFF (which are
	       even less portable) can be warned and/or disallowed even if other above-Unicode
	       code points are accepted by the UNICODE_WARN_FE_FF and UNICODE_DISALLOW_FE_FF
	       flags.

	       And finally, the flag UNICODE_WARN_ILLEGAL_INTERCHANGE selects all four of the
	       above WARN flags; and UNICODE_DISALLOW_ILLEGAL_INTERCHANGE selects all four
	       DISALLOW flags.

		       U8*     uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)

Variables created by ";xsubpp" and "xsubpp" internal functions
       ax      Variable which is setup by "xsubpp" to indicate the stack base offset, used by the
	       "ST", "XSprePUSH" and "XSRETURN" macros.  The "dMARK" macro must be called prior
	       to setup the "MARK" variable.

		       I32     ax

       CLASS   Variable which is setup by "xsubpp" to indicate the class name for a C++ XS
	       constructor.  This is always a "char*".	See "THIS".

		       char*   CLASS

       dAX     Sets up the "ax" variable.  This is usually handled automatically by "xsubpp" by
	       calling "dXSARGS".

			       dAX;

       dAXMARK Sets up the "ax" variable and stack marker variable "mark".  This is usually
	       handled automatically by "xsubpp" by calling "dXSARGS".

			       dAXMARK;

       dITEMS  Sets up the "items" variable.  This is usually handled automatically by "xsubpp"
	       by calling "dXSARGS".

			       dITEMS;

       dUNDERBAR
	       Sets up any variable needed by the "UNDERBAR" macro. It used to define
	       "padoff_du", but it is currently a noop. However, it is strongly advised to still
	       use it for ensuring past and future compatibility.

			       dUNDERBAR;

       dXSARGS Sets up stack and mark pointers for an XSUB, calling dSP and dMARK.  Sets up the
	       "ax" and "items" variables by calling "dAX" and "dITEMS".  This is usually handled
	       automatically by "xsubpp".

			       dXSARGS;

       dXSI32  Sets up the "ix" variable for an XSUB which has aliases.  This is usually handled
	       automatically by "xsubpp".

			       dXSI32;

       items   Variable which is setup by "xsubpp" to indicate the number of items on the stack.
	       See "Variable-length Parameter Lists" in perlxs.

		       I32     items

       ix      Variable which is setup by "xsubpp" to indicate which of an XSUB's aliases was
	       used to invoke it.  See "The ALIAS: Keyword" in perlxs.

		       I32     ix

       newXSproto
	       Used by "xsubpp" to hook up XSUBs as Perl subs.	Adds Perl prototypes to the subs.

       RETVAL  Variable which is setup by "xsubpp" to hold the return value for an XSUB. This is
	       always the proper type for the XSUB. See "The RETVAL Variable" in perlxs.

		       (whatever)      RETVAL

       ST      Used to access elements on the XSUB's stack.

		       SV*     ST(int ix)

       THIS    Variable which is setup by "xsubpp" to designate the object in a C++ XSUB.  This
	       is always the proper type for the C++ object.  See "CLASS" and "Using XS With C++"
	       in perlxs.

		       (whatever)      THIS

       UNDERBAR
	       The SV* corresponding to the $_ variable. Works even if there is a lexical $_ in
	       scope.

       XS      Macro to declare an XSUB and its C parameter list.  This is handled by "xsubpp".
	       It is the same as using the more explicit XS_EXTERNAL macro.

       XS_APIVERSION_BOOTCHECK
	       Macro to verify that the perl api version an XS module has been compiled against
	       matches the api version of the perl interpreter it's being loaded into.

			       XS_APIVERSION_BOOTCHECK;

       XS_EXTERNAL
	       Macro to declare an XSUB and its C parameter list explicitly exporting the
	       symbols.

       XS_INTERNAL
	       Macro to declare an XSUB and its C parameter list without exporting the symbols.
	       This is handled by "xsubpp" and generally preferable over exporting the XSUB
	       symbols unnecessarily.

       XS_VERSION
	       The version identifier for an XS module.  This is usually handled automatically by
	       "ExtUtils::MakeMaker".  See "XS_VERSION_BOOTCHECK".

       XS_VERSION_BOOTCHECK
	       Macro to verify that a PM module's $VERSION variable matches the XS module's
	       "XS_VERSION" variable.  This is usually handled automatically by "xsubpp".  See
	       "The VERSIONCHECK: Keyword" in perlxs.

			       XS_VERSION_BOOTCHECK;

Warning and Dieing
       croak   This is an XS interface to Perl's "die" function.

	       Take a sprintf-style format pattern and argument list.  These are used to generate
	       a string message.  If the message does not end with a newline, then it will be
	       extended with some indication of the current location in the code, as described
	       for "mess_sv".

	       The error message will be used as an exception, by default returning control to
	       the nearest enclosing "eval", but subject to modification by a $SIG{__DIE__}
	       handler.  In any case, the "croak" function never returns normally.

	       For historical reasons, if "pat" is null then the contents of "ERRSV" ($@) will be
	       used as an error message or object instead of building an error message from
	       arguments.  If you want to throw a non-string object, or build an error message in
	       an SV yourself, it is preferable to use the "croak_sv" function, which does not
	       involve clobbering "ERRSV".

		       void    croak(const char *pat, ...)

       croak_no_modify
	       Exactly equivalent to "Perl_croak(aTHX_ "%s", PL_no_modify)", but generates terser
	       object code than using "Perl_croak". Less code used on exception code paths
	       reduces CPU cache pressure.

		       void    croak_no_modify()

       croak_sv
	       This is an XS interface to Perl's "die" function.

	       "baseex" is the error message or object.  If it is a reference, it will be used
	       as-is.  Otherwise it is used as a string, and if it does not end with a newline
	       then it will be extended with some indication of the current location in the code,
	       as described for "mess_sv".

	       The error message or object will be used as an exception, by default returning
	       control to the nearest enclosing "eval", but subject to modification by a
	       $SIG{__DIE__} handler.  In any case, the "croak_sv" function never returns
	       normally.

	       To die with a simple string message, the "croak" function may be more convenient.

		       void    croak_sv(SV *baseex)

       die     Behaves the same as "croak", except for the return type.  It should be used only
	       where the "OP *" return type is required.  The function never actually returns.

		       OP *    die(const char *pat, ...)

       die_sv  Behaves the same as "croak_sv", except for the return type.  It should be used
	       only where the "OP *" return type is required.  The function never actually
	       returns.

		       OP *    die_sv(SV *baseex)

       vcroak  This is an XS interface to Perl's "die" function.

	       "pat" and "args" are a sprintf-style format pattern and encapsulated argument
	       list.  These are used to generate a string message.  If the message does not end
	       with a newline, then it will be extended with some indication of the current
	       location in the code, as described for "mess_sv".

	       The error message will be used as an exception, by default returning control to
	       the nearest enclosing "eval", but subject to modification by a $SIG{__DIE__}
	       handler.  In any case, the "croak" function never returns normally.

	       For historical reasons, if "pat" is null then the contents of "ERRSV" ($@) will be
	       used as an error message or object instead of building an error message from
	       arguments.  If you want to throw a non-string object, or build an error message in
	       an SV yourself, it is preferable to use the "croak_sv" function, which does not
	       involve clobbering "ERRSV".

		       void    vcroak(const char *pat, va_list *args)

       vwarn   This is an XS interface to Perl's "warn" function.

	       "pat" and "args" are a sprintf-style format pattern and encapsulated argument
	       list.  These are used to generate a string message.  If the message does not end
	       with a newline, then it will be extended with some indication of the current
	       location in the code, as described for "mess_sv".

	       The error message or object will by default be written to standard error, but this
	       is subject to modification by a $SIG{__WARN__} handler.

	       Unlike with "vcroak", "pat" is not permitted to be null.

		       void    vwarn(const char *pat, va_list *args)

       warn    This is an XS interface to Perl's "warn" function.

	       Take a sprintf-style format pattern and argument list.  These are used to generate
	       a string message.  If the message does not end with a newline, then it will be
	       extended with some indication of the current location in the code, as described
	       for "mess_sv".

	       The error message or object will by default be written to standard error, but this
	       is subject to modification by a $SIG{__WARN__} handler.

	       Unlike with "croak", "pat" is not permitted to be null.

		       void    warn(const char *pat, ...)

       warn_sv This is an XS interface to Perl's "warn" function.

	       "baseex" is the error message or object.  If it is a reference, it will be used
	       as-is.  Otherwise it is used as a string, and if it does not end with a newline
	       then it will be extended with some indication of the current location in the code,
	       as described for "mess_sv".

	       The error message or object will by default be written to standard error, but this
	       is subject to modification by a $SIG{__WARN__} handler.

	       To warn with a simple string message, the "warn" function may be more convenient.

		       void    warn_sv(SV *baseex)

Undocumented functions
       The following functions have been flagged as part of the public API, but are currently
       undocumented. Use them at your own risk, as the interfaces are subject to change.

       If you use one of them, you may wish to consider creating and submitting documentation for
       it. If your patch is accepted, this will indicate that the interface is stable (unless it
       is explicitly marked otherwise).

       GetVars
       Gv_AMupdate
       PerlIO_clearerr
       PerlIO_close
       PerlIO_context_layers
       PerlIO_eof
       PerlIO_error
       PerlIO_fileno
       PerlIO_fill
       PerlIO_flush
       PerlIO_get_base
       PerlIO_get_bufsiz
       PerlIO_get_cnt
       PerlIO_get_ptr
       PerlIO_read
       PerlIO_seek
       PerlIO_set_cnt
       PerlIO_set_ptrcnt
       PerlIO_setlinebuf
       PerlIO_stderr
       PerlIO_stdin
       PerlIO_stdout
       PerlIO_tell
       PerlIO_unread
       PerlIO_write
       Slab_Alloc
       Slab_Free
       _is_utf8_quotemeta
       amagic_call
       amagic_deref_call
       any_dup
       atfork_lock
       atfork_unlock
       av_arylen_p
       av_iter_p
       block_gimme
       call_atexit
       call_list
       calloc
       cast_i32
       cast_iv
       cast_ulong
       cast_uv
       ck_warner
       ck_warner_d
       ckwarn
       ckwarn_d
       clone_params_del
       clone_params_new
       croak_nocontext
       csighandler
       cx_dump
       cx_dup
       cxinc
       deb
       deb_nocontext
       debop
       debprofdump
       debstack
       debstackptrs
       delimcpy
       despatch_signals
       die_nocontext
       dirp_dup
       do_aspawn
       do_binmode
       do_close
       do_gv_dump
       do_gvgv_dump
       do_hv_dump
       do_join
       do_magic_dump
       do_op_dump
       do_open
       do_open9
       do_openn
       do_pmop_dump
       do_spawn
       do_spawn_nowait
       do_sprintf
       do_sv_dump
       doing_taint
       doref
       dounwind
       dowantarray
       dump_all
       dump_eval
       dump_fds
       dump_form
       dump_indent
       dump_mstats
       dump_packsubs
       dump_sub
       dump_vindent
       filter_add
       filter_del
       filter_read
       foldEQ_latin1
       form_nocontext
       fp_dup
       fprintf_nocontext
       free_global_struct
       free_tmps
       get_context
       get_mstats
       get_op_descs
       get_op_names
       get_ppaddr
       get_vtbl
       gp_dup
       gp_free
       gp_ref
       gv_AVadd
       gv_HVadd
       gv_IOadd
       gv_SVadd
       gv_add_by_type
       gv_autoload4
       gv_autoload_pv
       gv_autoload_pvn
       gv_autoload_sv
       gv_check
       gv_dump
       gv_efullname
       gv_efullname3
       gv_efullname4
       gv_fetchfile
       gv_fetchfile_flags
       gv_fetchpv
       gv_fetchpvn_flags
       gv_fetchsv
       gv_fullname
       gv_fullname3
       gv_fullname4
       gv_handler
       gv_name_set
       he_dup
       hek_dup
       hv_common
       hv_common_key_len
       hv_delayfree_ent
       hv_eiter_p
       hv_eiter_set
       hv_free_ent
       hv_ksplit
       hv_name_set
       hv_placeholders_get
       hv_placeholders_p
       hv_placeholders_set
       hv_riter_p
       hv_riter_set
       init_global_struct
       init_i18nl10n
       init_i18nl14n
       init_stacks
       init_tm
       instr
       is_lvalue_sub
       is_uni_alnum
       is_uni_alnum_lc
       is_uni_alpha
       is_uni_alpha_lc
       is_uni_ascii
       is_uni_ascii_lc
       is_uni_cntrl
       is_uni_cntrl_lc
       is_uni_digit
       is_uni_digit_lc
       is_uni_graph
       is_uni_graph_lc
       is_uni_idfirst
       is_uni_idfirst_lc
       is_uni_lower
       is_uni_lower_lc
       is_uni_print
       is_uni_print_lc
       is_uni_punct
       is_uni_punct_lc
       is_uni_space
       is_uni_space_lc
       is_uni_upper
       is_uni_upper_lc
       is_uni_xdigit
       is_uni_xdigit_lc
       is_utf8_alnum
       is_utf8_alpha
       is_utf8_ascii
       is_utf8_cntrl
       is_utf8_digit
       is_utf8_graph
       is_utf8_idcont
       is_utf8_idfirst
       is_utf8_lower
       is_utf8_mark
       is_utf8_perl_space
       is_utf8_perl_word
       is_utf8_posix_digit
       is_utf8_print
       is_utf8_punct
       is_utf8_space
       is_utf8_upper
       is_utf8_xdigit
       is_utf8_xidcont
       is_utf8_xidfirst
       leave_scope
       load_module_nocontext
       magic_dump
       malloc
       markstack_grow
       mess_nocontext
       mfree
       mg_dup
       mg_size
       mini_mktime
       moreswitches
       mro_get_from_name
       mro_get_private_data
       mro_set_mro
       mro_set_private_data
       my_atof
       my_atof2
       my_bcopy
       my_bzero
       my_chsize
       my_cxt_index
       my_cxt_init
       my_dirfd
       my_exit
       my_failure_exit
       my_fflush_all
       my_fork
       my_htonl
       my_lstat
       my_memcmp
       my_memset
       my_ntohl
       my_pclose
       my_popen
       my_popen_list
       my_setenv
       my_socketpair
       my_stat
       my_strftime
       my_strlcat
       my_strlcpy
       my_swap
       newANONATTRSUB
       newANONHASH
       newANONLIST
       newANONSUB
       newATTRSUB
       newAVREF
       newCVREF
       newFORM
       newGVREF
       newGVgen
       newGVgen_flags
       newHVREF
       newHVhv
       newIO
       newMYSUB
       newPROG
       newRV
       newSUB
       newSVREF
       newSVpvf_nocontext
       new_collate
       new_ctype
       new_numeric
       new_stackinfo
       ninstr
       op_dump
       op_free
       op_null
       op_refcnt_lock
       op_refcnt_unlock
       parser_dup
       perl_alloc_using
       perl_clone_using
       pmop_dump
       pop_scope
       pregcomp
       pregexec
       pregfree
       pregfree2
       printf_nocontext
       ptr_table_clear
       ptr_table_fetch
       ptr_table_free
       ptr_table_new
       ptr_table_split
       ptr_table_store
       push_scope
       re_compile
       re_dup_guts
       re_intuit_start
       re_intuit_string
       realloc
       reentrant_free
       reentrant_init
       reentrant_retry
       reentrant_size
       ref
       reg_named_buff_all
       reg_named_buff_exists
       reg_named_buff_fetch
       reg_named_buff_firstkey
       reg_named_buff_nextkey
       reg_named_buff_scalar
       regclass_swash
       regdump
       regdupe_internal
       regexec_flags
       regfree_internal
       reginitcolors
       regnext
       repeatcpy
       rninstr
       rsignal
       rsignal_state
       runops_debug
       runops_standard
       rvpv_dup
       safesyscalloc
       safesysfree
       safesysmalloc
       safesysrealloc
       save_I16
       save_I32
       save_I8
       save_adelete
       save_aelem
       save_aelem_flags
       save_alloc
       save_aptr
       save_ary
       save_bool
       save_clearsv
       save_delete
       save_destructor
       save_destructor_x
       save_freeop
       save_freepv
       save_freesv
       save_generic_pvref
       save_generic_svref
       save_gp
       save_hash
       save_hdelete
       save_helem
       save_helem_flags
       save_hints
       save_hptr
       save_int
       save_item
       save_iv
       save_list
       save_long
       save_mortalizesv
       save_nogv
       save_op
       save_padsv_and_mortalize
       save_pptr
       save_pushi32ptr
       save_pushptr
       save_pushptrptr
       save_re_context
       save_scalar
       save_set_svflags
       save_shared_pvref
       save_sptr
       save_svref
       save_vptr
       savestack_grow
       savestack_grow_cnt
       scan_num
       scan_vstring
       screaminstr
       seed
       set_context
       set_numeric_local
       set_numeric_radix
       set_numeric_standard
       share_hek
       si_dup
       ss_dup
       stack_grow
       start_subparse
       stashpv_hvname_match
       str_to_version
       sv_2iv
       sv_2pv
       sv_2uv
       sv_catpvf_mg_nocontext
       sv_catpvf_nocontext
       sv_compile_2op
       sv_dump
       sv_dup
       sv_dup_inc
       sv_peek
       sv_pvn_nomg
       sv_setpvf_mg_nocontext
       sv_setpvf_nocontext
       sv_utf8_upgrade_flags_grow
       swash_fetch
       swash_init
       sys_init
       sys_init3
       sys_intern_clear
       sys_intern_dup
       sys_intern_init
       sys_term
       taint_env
       taint_proper
       tmps_grow
       to_uni_fold
       to_uni_lower
       to_uni_lower_lc
       to_uni_title
       to_uni_title_lc
       to_uni_upper
       to_uni_upper_lc
       unlnk
       unsharepvn
       utf16_to_utf8
       utf16_to_utf8_reversed
       uvchr_to_utf8_flags
       uvuni_to_utf8
       vdeb
       vform
       vload_module
       vnewSVpvf
       vwarner
       warn_nocontext
       warner
       warner_nocontext
       whichsig
       whichsig_pv
       whichsig_pvn
       whichsig_sv

AUTHORS
       Until May 1997, this document was maintained by Jeff Okamoto <okamoto@corp.hp.com>.  It is
       now maintained as part of Perl itself.

       With lots of help and suggestions from Dean Roehrich, Malcolm Beattie, Andreas Koenig,
       Paul Hudson, Ilya Zakharevich, Paul Marquess, Neil Bowers, Matthew Green, Tim Bunce,
       Spider Boardman, Ulrich Pfeifer, Stephen McCamant, and Gurusamy Sarathy.

       API Listing originally by Dean Roehrich <roehrich@cray.com>.

       Updated to be autogenerated from comments in the source by Benjamin Stuhl.

SEE ALSO
       perlguts, perlxs, perlxstut, perlintern

perl v5.16.3				    2014-06-17				       PERLAPI(1)
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