Minor typo fix in a comment

[perl5.git] / intrpvar.h

/*   intrpvar.h 
 *
 *    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
 *    2006, 2007, 2008 by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
=head1 Per-Interpreter Variables
*/

/* These variables are per-interpreter in threaded/multiplicity builds,
 * global otherwise.

 * Don't forget to re-run embed.pl to propagate changes! */

/* New variables must be added to the very end for binary compatibility.
 * XSUB.h provides wrapper functions via perlapi.h that make this
 * irrelevant, but not all code may be expected to #include XSUB.h. */

/* Don't forget to add your variable also to perl_clone()! */

/* The 'I' prefix is only needed for vars that need appropriate #defines
 * generated when built with or without MULTIPLICITY.  It is also used
 * to generate the appropriate export list for win32.
 *
 * When building without MULTIPLICITY, these variables will be truly global.
 *
 * Important ones in the first cache line (if alignment is done right) */

PERLVAR(Istack_sp,	SV **)		/* top of the stack */
#ifdef OP_IN_REGISTER
PERLVAR(Iopsave,	OP *)
#else
PERLVAR(Iop,		OP *)		/* currently executing op */
#endif
PERLVAR(Icurpad,	SV **)		/* active pad (lexicals+tmps) */

PERLVAR(Istack_base,	SV **)
PERLVAR(Istack_max,	SV **)

PERLVAR(Iscopestack,	I32 *)		/* scopes we've ENTERed */
PERLVAR(Iscopestack_ix,	I32)
PERLVAR(Iscopestack_max,I32)

PERLVAR(Isavestack,	ANY *)		/* items that need to be restored when
					   LEAVEing scopes we've ENTERed */
PERLVAR(Isavestack_ix,	I32)
PERLVAR(Isavestack_max,	I32)

PERLVAR(Itmps_stack,	SV **)		/* mortals we've made */
PERLVARI(Itmps_ix,	I32,	-1)
PERLVARI(Itmps_floor,	I32,	-1)
PERLVAR(Itmps_max,	I32)
PERLVAR(Imodcount,	I32)		/* how much mod()ification in
					   assignment? */

PERLVAR(Imarkstack,	I32 *)		/* stack_sp locations we're
					   remembering */
PERLVAR(Imarkstack_ptr,	I32 *)
PERLVAR(Imarkstack_max,	I32 *)

PERLVAR(ISv,		SV *)		/* used to hold temporary values */
PERLVAR(IXpv,		XPV *)		/* used to hold temporary values */

/*
=for apidoc Amn|STRLEN|PL_na

A convenience variable which is typically used with C<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
C<SvPV_nolen> macro.

=cut
*/

PERLVAR(Ina,		STRLEN)		/* for use in SvPV when length is
					   Not Applicable */

/* stat stuff */
PERLVAR(Istatbuf,	Stat_t)
PERLVAR(Istatcache,	Stat_t)		/* _ */
PERLVAR(Istatgv,	GV *)
PERLVARI(Istatname,	SV *,	NULL)

#ifdef HAS_TIMES
PERLVAR(Itimesbuf,	struct tms)
#endif

/* Fields used by magic variables such as $@, $/ and so on */
PERLVAR(Icurpm,		PMOP *)		/* what to do \ interps in REs from */

/*
=for apidoc mn|SV*|PL_rs

The input record separator - C<$/> in Perl space.

=for apidoc mn|GV*|PL_last_in_gv

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

=for apidoc mn|GV*|PL_ofsgv

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

=cut
*/

PERLVAR(Irs,		SV *)		/* input record separator $/ */
PERLVAR(Ilast_in_gv,	GV *)		/* GV used in last <FH> */
PERLVAR(Iofsgv,		GV *)		/* GV of output field separator *, */
PERLVAR(Idefoutgv,	GV *)		/* default FH for output */
PERLVARI(Ichopset,	const char *, " \n-")	/* $: */
PERLVAR(Iformtarget,	SV *)
PERLVAR(Ibodytarget,	SV *)
PERLVAR(Itoptarget,	SV *)

/* Stashes */
PERLVAR(Idefstash,	HV *)		/* main symbol table */
PERLVAR(Icurstash,	HV *)		/* symbol table for current package */

PERLVAR(Irestartop,	OP *)		/* propagating an error from croak? */
PERLVAR(Icurcop,	COP *)
PERLVAR(Icurstack,	AV *)		/* THE STACK */
PERLVAR(Icurstackinfo,	PERL_SI *)	/* current stack + context */
PERLVAR(Imainstack,	AV *)		/* the stack when nothing funny is
					   happening */

PERLVAR(Itop_env,	JMPENV *)	/* ptr to current sigjmp environment */
PERLVAR(Istart_env,	JMPENV)		/* empty startup sigjmp environment */
PERLVARI(Ierrors,	SV *,	NULL)	/* outstanding queued errors */

/* statics "owned" by various functions */
PERLVAR(Ihv_fetch_ent_mh, HE*)		/* owned by hv_fetch_ent() */

PERLVAR(Ilastgotoprobe,	OP*)		/* from pp_ctl.c */

/* sort stuff */
PERLVAR(Isortcop,	OP *)		/* user defined sort routine */
PERLVAR(Isortstash,	HV *)		/* which is in some package or other */
PERLVAR(Ifirstgv,	GV *)		/* $a */
PERLVAR(Isecondgv,	GV *)		/* $b */

/* float buffer */
PERLVAR(Iefloatbuf,	char *)
PERLVAR(Iefloatsize,	STRLEN)

/* regex stuff */

PERLVAR(Iscreamfirst,	I32 *)
PERLVAR(Iscreamnext,	I32 *)
PERLVAR(Ilastscream,	SV *)

PERLVAR(Ireg_state,	struct re_save_state)

PERLVAR(Iregdummy,	regnode)	/* from regcomp.c */

PERLVARI(Idumpindent,	U16,	4)	/* number of blanks per dump
					   indentation level */


PERLVAR(Iutf8locale,	bool)		/* utf8 locale detected */
PERLVARI(Irehash_seed_set, bool, FALSE)	/* 582 hash initialized? */

PERLVARA(Icolors,6,	char *)		/* from regcomp.c */

PERLVARI(Ipeepp,	peep_t, MEMBER_TO_FPTR(Perl_peep))
					/* Pointer to peephole optimizer */

/*
=for apidoc Amn|Perl_ophook_t|PL_opfreehook

When non-C<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.

=cut
*/

PERLVARI(Iopfreehook,	Perl_ophook_t, 0) /* op_free() hook */

PERLVARI(Imaxscream,	I32,	-1)
PERLVARI(Ireginterp_cnt,I32,	 0)	/* Whether "Regexp" was interpolated. */
PERLVARI(Iwatchaddr,	char **, 0)
PERLVAR(Iwatchok,	char *)

/* the currently active slab in a chain of slabs of regmatch states,
 * and the currently active state within that slab */

PERLVARI(Iregmatch_slab, regmatch_slab *,	NULL)
PERLVAR(Iregmatch_state, regmatch_state *)

/* Put anything new that is pointer aligned here. */

PERLVAR(Idelaymagic,	U16)		/* ($<,$>) = ... */
PERLVAR(Ilocalizing,	U8)		/* are we processing a local() list? */
PERLVAR(Icolorset,	bool)		/* from regcomp.c */
PERLVARI(Idirty,	bool, FALSE)	/* in the middle of tearing things
					   down? */
PERLVAR(Iin_eval,	U8)		/* trap "fatal" errors? */
PERLVAR(Itainted,	bool)		/* using variables controlled by $< */

/* This value may be set when embedding for full cleanup  */
/* 0=none, 1=full, 2=full with checks */
/* mod_perl is special, and also assigns a meaning -1 */
PERLVARI(Iperl_destruct_level,	signed char,	0)

PERLVAR(Iperldb,	U32)

/* pseudo environmental stuff */
PERLVAR(Iorigargc,	int)
PERLVAR(Iorigargv,	char **)
PERLVAR(Ienvgv,		GV *)
PERLVAR(Iincgv,		GV *)
PERLVAR(Ihintgv,	GV *)
PERLVAR(Iorigfilename,	char *)
PERLVAR(Idiehook,	SV *)
PERLVAR(Iwarnhook,	SV *)

/* switches */
PERLVAR(Ipatchlevel,	SV *)
PERLVAR(Ilocalpatches,	const char * const *)
PERLVARI(Isplitstr,	const char *, " ")

PERLVAR(Iminus_c,	bool)
PERLVAR(Iminus_n,	bool)
PERLVAR(Iminus_p,	bool)
PERLVAR(Iminus_l,	bool)
PERLVAR(Iminus_a,	bool)
PERLVAR(Iminus_F,	bool)
PERLVAR(Idoswitches,	bool)
PERLVAR(Iminus_E,	bool)

/*

=for apidoc mn|bool|PL_dowarn

The C variable which corresponds to Perl's $^W warning variable.

=cut
*/

PERLVAR(Idowarn,	U8)
PERLVAR(Idoextract,	bool)
PERLVAR(Isawampersand,	bool)		/* must save all match strings */
PERLVAR(Iunsafe,	bool)
PERLVAR(Iexit_flags,	U8)		/* was exit() unexpected, etc. */
PERLVAR(Isrand_called,	bool)
/* Part of internal state, but makes the 16th 1 byte variable in a row.  */
PERLVAR(Itainting,	bool)		/* doing taint checks */
/* Space for a U8 */
PERLVAR(Iinplace,	char *)
PERLVAR(Ie_script,	SV *)

/* magical thingies */
PERLVAR(Ibasetime,	Time_t)		/* $^T */
PERLVAR(Iformfeed,	SV *)		/* $^L */


PERLVARI(Imaxsysfd,	I32,	MAXSYSFD)
					/* top fd to pass to subprocesses */
PERLVAR(Istatusvalue,	I32)		/* $? */
#ifdef VMS
PERLVAR(Istatusvalue_vms,U32)
#else
PERLVAR(Istatusvalue_posix,I32)
#endif

PERLVARI(Isig_pending, int,0)           /* Number if highest signal pending */
PERLVAR(Ipsig_pend, int *)		/* per-signal "count" of pending */

/* shortcuts to various I/O objects */
PERLVAR(Istdingv,	GV *)
PERLVAR(Istderrgv,	GV *)
PERLVAR(Idefgv,		GV *)
PERLVAR(Iargvgv,	GV *)
PERLVAR(Iargvoutgv,	GV *)
PERLVAR(Iargvout_stack,	AV *)

/* shortcuts to regexp stuff */
PERLVAR(Ireplgv,	GV *)

/* shortcuts to misc objects */
PERLVAR(Ierrgv,		GV *)

/* shortcuts to debugging objects */
PERLVAR(IDBgv,		GV *)
PERLVAR(IDBline,	GV *)

/*
=for apidoc mn|GV *|PL_DBsub
When Perl is run in debugging mode, with the B<-d> switch, this GV contains
the SV which holds the name of the sub being debugged.  This is the C
variable which corresponds to Perl's $DB::sub variable.  See
C<PL_DBsingle>.

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

=for apidoc mn|SV *|PL_DBtrace
Trace variable used when Perl is run in debugging mode, with the B<-d>
switch.  This is the C variable which corresponds to Perl's $DB::trace
variable.  See C<PL_DBsingle>.

=cut
*/

PERLVAR(IDBsub,		GV *)
PERLVAR(IDBsingle,	SV *)
PERLVAR(IDBtrace,	SV *)
PERLVAR(IDBsignal,	SV *)
PERLVAR(Idbargs,	AV *)		/* args to call listed by caller function */

/* symbol tables */
PERLVAR(Idebstash,	HV *)		/* symbol table for perldb package */
PERLVAR(Iglobalstash,	HV *)		/* global keyword overrides imported here */
PERLVAR(Icurstname,	SV *)		/* name of current package */
PERLVAR(Ibeginav,	AV *)		/* names of BEGIN subroutines */
PERLVAR(Iendav,		AV *)		/* names of END subroutines */
PERLVAR(Iunitcheckav,	AV *)		/* names of UNITCHECK subroutines */
PERLVAR(Icheckav,	AV *)		/* names of CHECK subroutines */
PERLVAR(Iinitav,	AV *)		/* names of INIT subroutines */
PERLVAR(Istrtab,	HV *)		/* shared string table */
PERLVARI(Isub_generation,U32,1)		/* incr to invalidate method cache */

/* funky return mechanisms */
PERLVAR(Iforkprocess,	int)		/* so do_open |- can return proc# */

/* memory management */
PERLVAR(Isv_count,	I32)		/* how many SV* are currently allocated */
PERLVAR(Isv_objcount,	I32)		/* how many objects are currently allocated */
PERLVAR(Isv_root,	SV*)		/* storage for SVs belonging to interp */
PERLVAR(Isv_arenaroot,	SV*)		/* list of areas for garbage collection */

/* subprocess state */
PERLVAR(Ifdpid,		AV *)		/* keep fd-to-pid mappings for my_popen */

/* internal state */
PERLVARI(Iop_mask,	char *,	NULL)	/* masked operations for safe evals */

/* current interpreter roots */
PERLVAR(Imain_cv,	CV *)
PERLVAR(Imain_root,	OP *)
PERLVAR(Imain_start,	OP *)
PERLVAR(Ieval_root,	OP *)
PERLVAR(Ieval_start,	OP *)

/* runtime control stuff */
PERLVARI(Icurcopdb,	COP *,	NULL)

PERLVAR(Ifilemode,	int)		/* so nextargv() can preserve mode */
PERLVAR(Ilastfd,	int)		/* what to preserve mode on */
PERLVAR(Ioldname,	char *)		/* what to preserve mode on */
PERLVAR(IArgv,		const char **)	/* stuff to free from do_aexec, vfork safe */
PERLVAR(ICmd,		char *)		/* stuff to free from do_aexec, vfork safe */
/* Elements in this array have ';' appended and are injected as a single line
   into the tokeniser. You can't put any (literal) newlines into any program
   you stuff in into this array, as the point where it's injected is expecting
   a single physical line. */
PERLVAR(Ipreambleav,	AV *)
PERLVAR(Imess_sv,	SV *)
PERLVAR(Iors_sv,	SV *)		/* output record separator $\ */
/* statics moved here for shared library purposes */
PERLVARI(Igensym,	I32,	0)	/* next symbol for getsym() to define */
PERLVARI(Icv_has_eval, bool, FALSE) /* PL_compcv includes an entereval or similar */
PERLVAR(Itaint_warn,	bool)      /* taint warns instead of dying */
PERLVARI(Ilaststype,	U16,	OP_STAT)
PERLVARI(Ilaststatval,	int,	-1)

/* interpreter atexit processing */
PERLVARI(Iexitlistlen,	I32, 0)		/* length of same */
PERLVARI(Iexitlist,	PerlExitListEntry *, NULL)
					/* list of exit functions */

/*
=for apidoc Amn|HV*|PL_modglobal

C<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.

=cut
*/

PERLVAR(Imodglobal,	HV *)		/* per-interp module data */

/* these used to be in global before 5.004_68 */
PERLVARI(Iprofiledata,	U32 *,	NULL)	/* table of ops, counts */

PERLVAR(Icompiling,	COP)		/* compiling/done executing marker */

PERLVAR(Icompcv,	CV *)		/* currently compiling subroutine */
PERLVAR(Icomppad,	AV *)		/* storage for lexically scoped temporaries */
PERLVAR(Icomppad_name,	AV *)		/* variable names for "my" variables */
PERLVAR(Icomppad_name_fill,	I32)	/* last "introduced" variable offset */
PERLVAR(Icomppad_name_floor,	I32)	/* start of vars in innermost block */

#ifdef HAVE_INTERP_INTERN
PERLVAR(Isys_intern,	struct interp_intern)
					/* platform internals */
#endif

/* more statics moved here */
PERLVAR(IDBcv,		CV *)		/* from perl.c */
PERLVARI(Igeneration,	int,	100)	/* from op.c */

PERLVARI(Iin_clean_objs,bool,    FALSE)	/* from sv.c */
PERLVARI(Iin_clean_all,	bool,    FALSE)	/* from sv.c */
PERLVAR(Inomemok,	bool)		/* let malloc context handle nomem */
PERLVARI(Isavebegin,     bool,	FALSE)	/* save BEGINs for compiler	*/

PERLVAR(Iuid,		Uid_t)		/* current real user id */
PERLVAR(Ieuid,		Uid_t)		/* current effective user id */
PERLVAR(Igid,		Gid_t)		/* current real group id */
PERLVAR(Iegid,		Gid_t)		/* current effective group id */
PERLVARI(Ian,		U32,	0)	/* malloc sequence number */
PERLVARI(Icop_seqmax,	U32,	0)	/* statement sequence number */
PERLVARI(Ievalseq,	U32,	0)	/* eval sequence number */
PERLVAR(Iorigalen,	U32)
PERLVAR(Iorigenviron,	char **)
#ifdef PERL_USES_PL_PIDSTATUS
PERLVAR(Ipidstatus,	HV *)		/* pid-to-status mappings for waitpid */
#endif
PERLVAR(Iosname,	char *)		/* operating system */

PERLVAR(Isighandlerp,	Sighandler_t)

PERLVARA(Ibody_roots,	PERL_ARENA_ROOTS_SIZE, void*) /* array of body roots */

PERLVAR(Inice_chunk,	char *)		/* a nice chunk of memory to reuse */
PERLVAR(Inice_chunk_size,	U32)	/* how nice the chunk of memory is */

PERLVARI(Imaxo,	int,	MAXO)		/* maximum number of ops */

PERLVARI(Irunops,	runops_proc_t,	MEMBER_TO_FPTR(RUNOPS_DEFAULT))

/*
=for apidoc Amn|SV|PL_sv_undef
This is the C<undef> SV.  Always refer to this as C<&PL_sv_undef>.

=for apidoc Amn|SV|PL_sv_no
This is the C<false> SV.  See C<PL_sv_yes>.  Always refer to this as
C<&PL_sv_no>.

=for apidoc Amn|SV|PL_sv_yes
This is the C<true> SV.  See C<PL_sv_no>.  Always refer to this as
C<&PL_sv_yes>.

=cut
*/

PERLVAR(Isv_undef,	SV)
PERLVAR(Isv_no,		SV)
PERLVAR(Isv_yes,	SV)

PERLVAR(Isubname,	SV *)		/* name of current subroutine */

PERLVAR(Isubline,	I32)		/* line this subroutine began on */
PERLVAR(Imin_intro_pending,	I32)	/* start of vars to introduce */

PERLVAR(Imax_intro_pending,	I32)	/* end of vars to introduce */
PERLVAR(Ipadix,		I32)		/* max used index in current "register" pad */

PERLVAR(Ipadix_floor,	I32)		/* how low may inner block reset padix */

PERLVAR(Ihints,		U32)		/* pragma-tic compile-time flags */

PERLVAR(Idebug,		VOL U32)	/* flags given to -D switch */

/* Perl_Ibreakable_sub_generation_ptr was too long for VMS, hence "gen"  */
PERLVARI(Ibreakable_sub_gen, U32, 0)

PERLVARI(Iamagic_generation,	long,	0)

#ifdef USE_LOCALE_COLLATE
PERLVAR(Icollation_name,char *)		/* Name of current collation */
PERLVAR(Icollxfrm_base,	Size_t)		/* Basic overhead in *xfrm() */
PERLVARI(Icollxfrm_mult,Size_t,	2)	/* Expansion factor in *xfrm() */
PERLVARI(Icollation_ix,	U32,	0)	/* Collation generation index */
PERLVARI(Icollation_standard, bool,	TRUE)
					/* Assume simple collation */
#endif /* USE_LOCALE_COLLATE */


#if defined (PERL_UTF8_CACHE_ASSERT) || defined (DEBUGGING)
#  define PERL___I -1
#else
#  define PERL___I 1
#endif
PERLVARI(Iutf8cache, I8, PERL___I)	/* Is the utf8 caching code enabled? */
#undef PERL___I


#ifdef USE_LOCALE_NUMERIC

PERLVARI(Inumeric_standard,	bool,	TRUE)
					/* Assume simple numerics */
PERLVARI(Inumeric_local,	bool,	TRUE)
					/* Assume local numerics */
PERLVAR(Inumeric_name,	char *)		/* Name of current numeric locale */
#endif /* !USE_LOCALE_NUMERIC */

/* utf8 character classes */
PERLVAR(Iutf8_alnum,	SV *)
PERLVAR(Iutf8_alnumc,	SV *)
PERLVAR(Iutf8_ascii,	SV *)
PERLVAR(Iutf8_alpha,	SV *)
PERLVAR(Iutf8_space,	SV *)
PERLVAR(Iutf8_cntrl,	SV *)
PERLVAR(Iutf8_graph,	SV *)
PERLVAR(Iutf8_digit,	SV *)
PERLVAR(Iutf8_upper,	SV *)
PERLVAR(Iutf8_lower,	SV *)
PERLVAR(Iutf8_print,	SV *)
PERLVAR(Iutf8_punct,	SV *)
PERLVAR(Iutf8_xdigit,	SV *)
PERLVAR(Iutf8_mark,	SV *)
PERLVAR(Iutf8_toupper,	SV *)
PERLVAR(Iutf8_totitle,	SV *)
PERLVAR(Iutf8_tolower,	SV *)
PERLVAR(Iutf8_tofold,	SV *)
PERLVAR(Ilast_swash_hv,	HV *)
PERLVAR(Ilast_swash_tmps,	U8 *)
PERLVAR(Ilast_swash_slen,	STRLEN)
PERLVARA(Ilast_swash_key,10,	U8)
PERLVAR(Ilast_swash_klen,	U8)	/* Only needs to store 0-10  */

#ifdef FCRYPT
PERLVARI(Icryptseen,	bool,	FALSE)	/* has fast crypt() been initialized? */
#endif

PERLVAR(Ipad_reset_pending,	bool)	/* reset pad on next attempted alloc */

PERLVARI(Iglob_index,	int,	0)


PERLVAR(Iparser,	yy_parser *)	/* current parser state */

/* Array of signal handlers, indexed by signal number, through which the C
   signal handler dispatches.  */
PERLVAR(Ipsig_ptr, SV**)
/* Array of names of signals, indexed by signal number, for (re)use as the first
   argument to a signal handler.   Only one block of memory is allocated for
   both psig_name and psig_ptr.  */
PERLVAR(Ipsig_name, SV**)		

#if defined(PERL_IMPLICIT_SYS)
PERLVAR(IMem,		struct IPerlMem*)
PERLVAR(IMemShared,	struct IPerlMem*)
PERLVAR(IMemParse,	struct IPerlMem*)
PERLVAR(IEnv,		struct IPerlEnv*)
PERLVAR(IStdIO,		struct IPerlStdIO*)
PERLVAR(ILIO,		struct IPerlLIO*)
PERLVAR(IDir,		struct IPerlDir*)
PERLVAR(ISock,		struct IPerlSock*)
PERLVAR(IProc,		struct IPerlProc*)
#endif

PERLVAR(Iptr_table,	PTR_TBL_t*)
PERLVARI(Ibeginav_save, AV*, NULL)	/* save BEGIN{}s when compiling */

PERLVAR(Ibody_arenas, void*) /* pointer to list of body-arenas */


#ifdef USE_LOCALE_NUMERIC

PERLVAR(Inumeric_radix_sv,	SV *)	/* The radix separator if not '.' */

#endif

#if defined(USE_ITHREADS)
PERLVAR(Iregex_pad,     SV**)		/* Shortcut into the array of
					   regex_padav */
PERLVAR(Iregex_padav,   AV*)		/* All regex objects, indexed via the
					   values in op_pmoffset of pmop.
					   Entry 0 is an SV whose PV is a
					   "packed" list of IVs listing
					   the now-free slots in the array */
#endif

#ifdef USE_REENTRANT_API
PERLVAR(Ireentrant_buffer, REENTR*)	/* here we store the _r buffers */
#endif

PERLVAR(Icustom_op_names, HV*)  /* Names of user defined ops */
PERLVAR(Icustom_op_descs, HV*)  /* Descriptions of user defined ops */

#ifdef PERLIO_LAYERS
PERLVARI(Iperlio, PerlIO *,NULL)
PERLVARI(Iknown_layers, PerlIO_list_t *,NULL)
PERLVARI(Idef_layerlist, PerlIO_list_t *,NULL)
#endif

PERLVARI(Iencoding,	SV*, NULL)		/* character encoding */

PERLVAR(Idebug_pad,	struct perl_debug_pad)	/* always needed because of the re extension */

PERLVAR(Iutf8_idstart,	SV *)
PERLVAR(Iutf8_idcont,	SV *)

PERLVAR(Isort_RealCmp,  SVCOMPARE_t)

PERLVARI(Icheckav_save, AV*, NULL)	/* save CHECK{}s when compiling */
PERLVARI(Iunitcheckav_save, AV*, NULL)	/* save UNITCHECK{}s when compiling */

PERLVARI(Iclocktick, long, 0)	/* this many times() ticks in a second */

PERLVARI(Iin_load_module, int, 0)	/* to prevent recursions in PerlIO_find_layer */

PERLVAR(Iunicode, U32)	/* Unicode features: $ENV{PERL_UNICODE} or -C */

PERLVAR(Isignals, U32)	/* Using which pre-5.8 signals */

PERLVAR(Ireentrant_retint, int)	/* Integer return value from reentrant functions */

PERLVAR(Istashcache,	HV *)		/* Cache to speed up S_method_common */

/* Hooks to shared SVs and locks. */
PERLVARI(Isharehook,	share_proc_t,	MEMBER_TO_FPTR(Perl_sv_nosharing))
PERLVARI(Ilockhook,	share_proc_t,	MEMBER_TO_FPTR(Perl_sv_nosharing))
#ifdef NO_MATHOMS
#  define PERL_UNLOCK_HOOK Perl_sv_nosharing
#else
/* This reference ensures that the mathoms are linked with perl */
#  define PERL_UNLOCK_HOOK Perl_sv_nounlocking
#endif
PERLVARI(Iunlockhook,	share_proc_t,	MEMBER_TO_FPTR(PERL_UNLOCK_HOOK))

PERLVARI(Ithreadhook,	thrhook_proc_t,	MEMBER_TO_FPTR(Perl_nothreadhook))

PERLVARI(Ihash_seed, UV, 0)		/* Hash initializer */

PERLVARI(Irehash_seed, UV, 0)		/* 582 hash initializer */

PERLVARI(Iisarev, HV*, NULL) /* Reverse map of @ISA dependencies */

/* The last unconditional member of the interpreter structure when 5.10.0 was
   released. The offset of the end of this is baked into a global variable in 
   any shared perl library which will allow a sanity test in future perl
   releases.  */
#define PERL_LAST_5_10_0_INTERP_MEMBER	Iisarev

#ifdef PERL_IMPLICIT_CONTEXT
PERLVARI(Imy_cxt_size, int, 0)		/* size of PL_my_cxt_list */
PERLVARI(Imy_cxt_list, void **, NULL) /* per-module array of MY_CXT pointers */
#  ifdef PERL_GLOBAL_STRUCT_PRIVATE
PERLVARI(Imy_cxt_keys, const char **, NULL) /* per-module array of pointers to MY_CXT_KEY constants */
#  endif
#endif

#ifdef PERL_TRACK_MEMPOOL
/* For use with the memory debugging code in util.c  */
PERLVAR(Imemory_debug_header, struct perl_memory_debug_header)
#endif

#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
/* File descriptor to talk to the child which dumps scalars.  */
PERLVARI(Idumper_fd, int, -1)
#endif

/* Stores the PPID */
#ifdef THREADS_HAVE_PIDS
PERLVARI(Ippid,		IV,		0)
#endif

#ifdef PERL_MAD
PERLVARI(Imadskills,	bool, FALSE)	/* preserve all syntactic info */
					/* (MAD = Misc Attribute Decoration) */
PERLVARI(Ixmlfp, PerlIO *,NULL)
#endif

#ifdef PL_OP_SLAB_ALLOC
PERLVAR(IOpPtr,I32 **)
PERLVARI(IOpSpace,I32,0)
PERLVAR(IOpSlab,I32 *)
#endif

#ifdef PERL_DEBUG_READONLY_OPS
PERLVARI(Islabs, I32**, NULL)	/* Array of slabs that have been allocated */
PERLVARI(Islab_count, U32, 0)	/* Size of the array */
#endif

/* Can shared object be destroyed */
PERLVARI(Idestroyhook, destroyable_proc_t, MEMBER_TO_FPTR(Perl_sv_destroyable))

#ifdef DEBUG_LEAKING_SCALARS
PERLVARI(Isv_serial, U32, 0) /* SV serial number, used in sv.c */
#endif

/* Register of known Method Resolution Orders.
   What this actually points to is an implementation detail (it may change to
   a structure incorporating a reference count - use mro_get_from_name to
   retrieve a C<struct mro_alg *>  */
PERLVAR(Iregistered_mros, HV *)

/* If you are adding a U8 or U16, check to see if there are 'Space' comments
 * above on where there are gaps which currently will be structure padding.  */

/* Within a stable branch, new variables must be added to the very end, before
 * this comment, for binary compatibility (the offsets of the old members must
 *  not change).
 * (Don't forget to add your variable also to perl_clone()!)
 * XSUB.h provides wrapper functions via perlapi.h that make this
 * irrelevant, but not all code may be expected to #include XSUB.h.
 */