text: /*    op.h
   *
   *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 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.
   *
   */
  
  /*
   * The fields of BASEOP are:
   *	op_next		Pointer to next ppcode to execute after this one.
   *			(Top level pre-grafted op points to first op,
   *			but this is replaced when op is grafted in, when
   *			this op will point to the real next op, and the new
   *			parent takes over role of remembering starting op.)
   *	op_ppaddr	Pointer to current ppcode's function.
   *	op_type		The type of the operation.
   *	op_opt		Whether or not the op has been optimised by the
   *			peephole optimiser.
   *	op_slabbed	allocated via opslab
   *	op_static	tell op_free() to skip PerlMemShared_free(), when
   *                      !op_slabbed.
   *	op_savefree	on savestack via SAVEFREEOP
   *	op_folded	Result/remainder of a constant fold operation.
   *	op_moresib	this op is is not the last sibling
   *	op_typechecked	Avoid type checking at run-time, already done by the compiler.
   *	op_flags	Flags common to all operations.  See OPf_* below.
   *	op_private	Flags peculiar to a particular operation (BUT,
   *			by default, set to the number of children until
   *			the operation is privatized by a check routine,
   *			which may or may not check number of children).
   */
  #include "op_reg_common.h"
  #include "opnames.h"
  
  #define OPCODE U16
  
  typedef PERL_BITFIELD16 Optype;
  
  #ifdef BASEOP_DEFINITION
  #define BASEOP BASEOP_DEFINITION
  #else
  #define BASEOP				\
      OP*		op_next;		\
      OP*		op_sibparent;		\
      OP*		(*op_ppaddr)(pTHX);	\
      PADOFFSET	op_targ;		\
      PERL_BITFIELD16 op_type:9;		\
      PERL_BITFIELD16 op_opt:1;		\
      PERL_BITFIELD16 op_slabbed:1;	\
      PERL_BITFIELD16 op_savefree:1;	\
      PERL_BITFIELD16 op_static:1;	\
      PERL_BITFIELD16 op_folded:1;	\
      PERL_BITFIELD16 op_moresib:1;       \
      PERL_BITFIELD16 op_typechecked:1;	\
      U8		op_flags;		\
      U8		op_private;             \
      U8		op_rettype;
  #endif
  
  /* Class::XSAccessor abuses this */
  #define op_spare op_typechecked
  
  /* If op_type:9 is changed to :10, also change cx_pusheval()
     Also, if the type of op_type is ever changed (e.g. to PERL_BITFIELD32)
     then all the other bit-fields before/after it should change their
     types too to let VC pack them into the same 4 byte integer.*/
  
  #define OpFLAGS(o)   (o)->op_flags
  #define OpPRIVATE(o) (o)->op_private
  #define OpTYPE(o)    (o)->op_type
  #define OpTARG(o)    (o)->op_targ
  
  /* for efficiency, requires OPf_WANT_VOID == G_VOID etc */
  #define OP_GIMME(o,dfl) \
  	((OpFLAGS(o) & OPf_WANT) ? (OpFLAGS(o) & OPf_WANT) : dfl)
  
  #define OP_GIMME_REVERSE(flags)	((flags) & G_WANT)
  
  /*
  =head1 "Gimme" Values
  
  =for apidoc Amn|U32|GIMME_V
  The XSUB-writer's equivalent to Perl's C<wantarray>.  Returns C<G_VOID>,
  C<G_SCALAR> or C<G_ARRAY> for void, scalar or list context,
  respectively.  See L<perlcall> for a usage example.
  
  =for apidoc Amn|U32|GIMME
  A backward-compatible version of C<GIMME_V> which can only return
  C<G_SCALAR> or C<G_ARRAY>; in a void context, it returns C<G_SCALAR>.
  Deprecated.  Use C<GIMME_V> instead.
  
  =cut
  */
  
  #define GIMME_V		OP_GIMME(PL_op, block_gimme())
  
  /* Public flags */
  
  #define OPf_WANT	3	/* Mask for "want" bits: */
  #define  OPf_WANT_VOID	 1	/*   Want nothing */
  #define  OPf_WANT_SCALAR 2	/*   Want single value */
  #define  OPf_WANT_LIST	 3	/*   Want list of any length */
  #define OPf_KIDS	4	/* There is a firstborn child. */
  #define OPf_PARENS	8	/* This operator was parenthesized. */
  				/*  (Or block needs explicit scope entry.) */
  #define OPf_REF		16	/* Certified reference. */
  				/*  (Return container, not containee). */
  #define OPf_MOD		32	/* Will modify (lvalue). */
  
  #define OPf_STACKED	64	/* Some arg is arriving on the stack. */
                                  /*   Indicates mutator-variant of op for those
                                   *     ops which support them, e.g. $x += 1
                                   */
  
  #define OPf_SPECIAL	128	/* Do something weird for this op: */
  				/*  On local LVAL, don't init local value. */
  				/*  On OP_SORT, subroutine is inlined. */
  				/*  On OP_NOT, inversion was implicit. */
  				/*  On OP_LEAVE, don't restore curpm, e.g.
                                   *      /(...)/ while ...>;  */
  				/*  On truncate, we truncate filehandle */
  				/*  On control verbs, we saw no label */
  				/*  On flipflop, we saw ... instead of .. */
  				/*  On UNOPs, saw bare parens, e.g. eof(). */
  				/*  On OP_CHDIR, handle (or bare parens) */
  				/*  On OP_NULL, saw a "do". */
  				/*  On OP_EXISTS, treat av as av, not avhv.  */
  				/*  On OP_(ENTER|LEAVE)EVAL, don't clear $@ */
  				/*  On regcomp, "use re 'eval'" was in scope */
  				/*  On RV2[ACGHS]V, don't create GV--in
  				    defined()*/
  				/*  On OP_DBSTATE, indicates breakpoint
  				 *    (runtime property) */
  				/*  On OP_REQUIRE, was seen as CORE::require */
  				/*  On OP_(ENTER|LEAVE)WHEN, there's
  				    no condition */
  				/*  On OP_SMARTMATCH, an implicit smartmatch */
  				/*  On OP_ANONHASH and OP_ANONLIST, create a
  				    reference to the new anon hash or array */
  				/*  On OP_HELEM, OP_MULTIDEREF and OP_HSLICE,
                                      localization will be followed by assignment,
                                      so do not wipe the target if it is special
                                      (e.g. a glob or a magic SV) */
  				/*  On OP_MATCH, OP_SUBST & OP_TRANS, the
  				    operand of a logical or conditional
  				    that was optimised away, so it should
  				    not be bound via =~ */
  				/*  On OP_CONST, from a constant CV */
  				/*  On OP_GLOB, two meanings:
  				    - Before ck_glob, called as CORE::glob
  				    - After ck_glob, use Perl glob function
  			         */
                                  /*  On OP_PADRANGE, push @_ */
                                  /*  On OP_DUMP, has no label */
                                  /*  On OP_UNSTACK, in a C-style for loop */
                                  /*  On OP_[SA]ASSIGN :const assign */
  /* There is no room in op_flags for this one, so it has its own bit-
     field member (op_folded) instead.  The flag is only used to tell
     op_convert_list to set op_folded.  */
  #define OPf_FOLDED      (1<<16)
  
  /* old names; don't use in new code, but don't break them, either */
  #define OPf_LIST	OPf_WANT_LIST
  #define OPf_KNOW	OPf_WANT
  
  #define OpKIDS(o)    (OpFLAGS(o) & OPf_KIDS)
  #define OpSPECIAL(o) (OpFLAGS(o) & OPf_SPECIAL)
  #define OpSTACKED(o) (OpFLAGS(o) & OPf_STACKED)
  #define OpPARENS(o)  (OpFLAGS(o) & OPf_PARENS)
  #define OpDEREF(o)   (OpPRIVATE(o) & OPpDEREF)
  #define OpWANT_VOID(o) ((OpFLAGS(o) & OPf_WANT) == OPf_WANT_VOID)
  #define OpWANT_SCALAR(o) ((OpFLAGS(o) & OPf_WANT) == OPf_WANT_SCALAR)
  #define OpWANT_LIST(o) ((OpFLAGS(o) & OPf_WANT) == OPf_WANT_LIST)
  
  #if !defined(PERL_CORE) && !defined(PERL_EXT)
  #  define GIMME \
         (OpFLAGS(PL_op) & OPf_WANT                                       \
  	   ? (OpWANT_LIST(PL_op)                                        \
  	      ? G_ARRAY							\
  	      : G_SCALAR)						\
  	   : dowantarray())
  #endif
  
  /* NOTE: OPp* flags are now auto-generated and defined in opcode.h,
   *       from data in regen/op_private */
  
  
  #define OPpTRANS_ALL	(OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF|OPpTRANS_IDENTICAL|OPpTRANS_SQUASH|OPpTRANS_COMPLEMENT|OPpTRANS_GROWS|OPpTRANS_DELETE)
  
  
  
  /* Mask for OP_ENTERSUB flags, the absence of which must be propagated
   in dynamic context */
  #define OPpENTERSUB_LVAL_MASK (OPpLVAL_INTRO|OPpENTERSUB_INARGS)
  
  
  /* things that can be elements of op_aux */
  typedef union  {
      PADOFFSET pad_offset;
      SV        *sv;
      IV        iv;
      UV        uv;
      char      *pv;
      SSize_t   ssize;
  } UNOP_AUX_item;
  
  #ifdef USE_ITHREADS
  #  define UNOP_AUX_item_sv(item) PAD_SVl((item)->pad_offset)
  #else
  #  define UNOP_AUX_item_sv(item) ((item)->sv)
  #endif
  
  
  struct op {
      BASEOP
  };
  
  struct unop {
      BASEOP
      OP *	op_first; /* must be first */
  };
  
  struct unop_aux {
      BASEOP
      OP  	  *op_first; /* must be first */
      UNOP_AUX_item *op_aux;
  };
  
  struct binop {
      BASEOP
      OP *	op_first; /* must be first */
      OP *	op_last;  /* must be second */
  };
  
  struct logop {
      BASEOP
      OP *	op_first; /* must be first */
      OP *	op_other;
  };
  
  struct listop {
      BASEOP
      OP *	op_first; /* must be first */
      OP *	op_last;  /* must be second */
  };
  
  struct methop {
      BASEOP
      union {
          /* op_u.op_first *must* be aligned the same as the op_first
           * field of the other op types, and op_u.op_meth_sv *must*
           * be aligned with op_sv */
          OP* op_first;   /* optree for method name */
          SV* op_meth_sv; /* static method name */
      } op_u;
  #ifdef USE_ITHREADS
      PADOFFSET op_rclass_targ; /* pad index for redirect class */
  #else
      SV*       op_rclass_sv;   /* static redirect class $o->A::meth() */
  #endif
  };
  
  struct pmop {
      BASEOP
      OP *	op_first; /* must be first */
      OP *	op_last;  /* must be second */
  #ifdef USE_ITHREADS
      PADOFFSET   op_pmoffset;
  #else
      REGEXP *    op_pmregexp;            /* compiled expression */
  #endif
      U32         op_pmflags;
      union {
  	OP *	op_pmreplroot;		/* For OP_SUBST */
  	PADOFFSET op_pmtargetoff;	/* For OP_SPLIT lex ary or thr GV */
  	GV *	op_pmtargetgv;	        /* For OP_SPLIT non-threaded GV */
      }	op_pmreplrootu;
      union {
  	OP *	op_pmreplstart;	/* Only used in OP_SUBST */
  #ifdef USE_ITHREADS
  	PADOFFSET op_pmstashoff; /* Only used in OP_MATCH, with PMf_ONCE set */
  #else
  	HV *	op_pmstash;
  #endif
      }		op_pmstashstartu;
      OP *	op_code_list;	/* list of (?{}) code blocks */
  };
  
  #ifdef USE_ITHREADS
  #define PM_GETRE(o)	(SvTYPE(PL_regex_pad[(o)->op_pmoffset]) == SVt_REGEXP \
  		 	 ? (REGEXP*)(PL_regex_pad[(o)->op_pmoffset]) : NULL)
  /* The assignment is just to enforce type safety (or at least get a warning).
   */
  /* With first class regexps not via a reference one needs to assign
     UNDEF under ithreads. (This would probably work unthreaded, but NULL
     is cheaper. I guess we could allow NULL, but the check above would get
     more complex, and we'd have an AV with (SV*)NULL in it, which feels bad */
  /* BEWARE - something that calls this macro passes (r) which has a side
     effect.  */
  #define PM_SETRE(o,r)	STMT_START {					\
                              REGEXP *const _pm_setre = (r);		\
                              assert(_pm_setre);				\
  			    PL_regex_pad[(o)->op_pmoffset] = MUTABLE_SV(_pm_setre); \
                          } STMT_END
  #else
  #define PM_GETRE(o)     ((o)->op_pmregexp)
  #define PM_SETRE(o,r)   ((o)->op_pmregexp = (r))
  #endif
  
  /* Currently these PMf flags occupy a single 32-bit word.  Not all bits are
   * currently used.  The lower bits are shared with their corresponding RXf flag
   * bits, up to but not including _RXf_PMf_SHIFT_NEXT.  The unused bits
   * immediately follow; finally the used Pmf-only (unshared) bits, so that the
   * highest bit in the word is used.  This gathers all the unused bits as a pool
   * in the middle, like so: 11111111111111110000001111111111
   * where the '1's represent used bits, and the '0's unused.  This design allows
   * us to allocate off one end of the pool if we need to add a shared bit, and
   * off the other end if we need a non-shared bit, without disturbing the other
   * bits.  This maximizes the likelihood of being able to change things without
   * breaking binary compatibility.
   *
   * To add shared bits, do so in op_reg_common.h.  This should change
   * _RXf_PMf_SHIFT_NEXT so that things won't compile.  Then come to regexp.h and
   * op.h and adjust the constant adders in the definitions of PMf_BASE_SHIFT and
   * Pmf_BASE_SHIFT down by the number of shared bits you added.  That's it.
   * Things should be binary compatible.  But if either of these gets to having
   * to subtract rather than add, leave at 0 and adjust all the entries below
   * that are in terms of this according.  But if the first one of those is
   * already PMf_BASE_SHIFT+0, there are no bits left, and a redesign is in
   * order.
   *
   * To remove unshared bits, just delete its entry.  If you're where breaking
   * binary compatibility is ok to do, you might want to adjust things to move
   * the newly opened space so that it gets absorbed into the common pool.
   *
   * To add unshared bits, first use up any gaps in the middle.  Otherwise,
   * allocate off the low end until you get to PMf_BASE_SHIFT+0.  If that isn't
   * enough, move PMf_BASE_SHIFT down (if possible) and add the new bit at the
   * other end instead; this preserves binary compatibility. */
  #define PMf_BASE_SHIFT (_RXf_PMf_SHIFT_NEXT+2)
  
  /* Set by the parser if it discovers an error, so the regex shouldn't be
   * compiled */
  #define PMf_HAS_ERROR	(1U<<(PMf_BASE_SHIFT+4))
  
  /* 'use re "taint"' in scope: taint $1 etc. if target tainted */
  #define PMf_RETAINT	(1U<<(PMf_BASE_SHIFT+5))
  
  /* match successfully only once per reset, with related flag RXf_USED in
   * re->extflags holding state.  This is used only for ?? matches, and only on
   * OP_MATCH and OP_QR */
  #define PMf_ONCE	(1U<<(PMf_BASE_SHIFT+6))
  
  /* PMf_ONCE, i.e. ?pat?, has matched successfully.  Not used under threading. */
  #define PMf_USED        (1U<<(PMf_BASE_SHIFT+7))
  
  /* subst replacement is constant */
  #define PMf_CONST	(1U<<(PMf_BASE_SHIFT+8))
  
  /* keep 1st runtime pattern forever */
  #define PMf_KEEP	(1U<<(PMf_BASE_SHIFT+9))
  
  #define PMf_GLOBAL	(1U<<(PMf_BASE_SHIFT+10)) /* pattern had a g modifier */
  
  /* don't reset pos() if //g fails */
  #define PMf_CONTINUE	(1U<<(PMf_BASE_SHIFT+11))
  
  /* evaluating replacement as expr */
  #define PMf_EVAL	(1U<<(PMf_BASE_SHIFT+12))
  
  /* Return substituted string instead of modifying it. */
  #define PMf_NONDESTRUCT	(1U<<(PMf_BASE_SHIFT+13))
  
  /* the pattern has a CV attached (currently only under qr/...(?{}).../) */
  #define PMf_HAS_CV	(1U<<(PMf_BASE_SHIFT+14))
  
  /* op_code_list is private; don't free it etc. It may well point to
   * code within another sub, with different pad etc */
  #define PMf_CODELIST_PRIVATE	(1U<<(PMf_BASE_SHIFT+15))
  
  /* the PMOP is a QR (we should be able to detect that from the op type,
   * but the regex compilation API passes just the pm flags, not the op
   * itself */
  #define PMf_IS_QR	(1U<<(PMf_BASE_SHIFT+16))
  #define PMf_USE_RE_EVAL	(1U<<(PMf_BASE_SHIFT+17)) /* use re'eval' in scope */
  
  /* See comments at the beginning of these defines about adding bits.  The
   * highest bit position should be used, so that if PMf_BASE_SHIFT gets
   * increased, the #error below will be triggered so that you will be reminded
   * to adjust things at the other end to keep the bit positions unchanged */
  #if PMf_BASE_SHIFT+17 > 31
  #   error Too many PMf_ bits used.  See above and regnodes.h for any spare in middle
  #endif
  
  #ifdef USE_ITHREADS
  
  #  define PmopSTASH(o)         ((o)->op_pmflags & PMf_ONCE                         \
                                  ? PL_stashpad[(o)->op_pmstashstartu.op_pmstashoff]   \
                                  : NULL)
  #  define PmopSTASH_set(o,hv)	\
  	(assert_((o)->op_pmflags & PMf_ONCE)				\
  	 (o)->op_pmstashstartu.op_pmstashoff =				\
  	    (hv) ? alloccopstash(hv) : 0)
  #else
  #  define PmopSTASH(o)							\
      (((o)->op_pmflags & PMf_ONCE) ? (o)->op_pmstashstartu.op_pmstash : NULL)
  #  if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
  #    define PmopSTASH_set(o,hv)		({				\
  	assert((o)->op_pmflags & PMf_ONCE);				\
  	((o)->op_pmstashstartu.op_pmstash = (hv));			\
      })
  #  else
  #    define PmopSTASH_set(o,hv)	((o)->op_pmstashstartu.op_pmstash = (hv))
  #  endif
  #endif
  #define PmopSTASHPV(o)	(PmopSTASH(o) ? HvNAME_get(PmopSTASH(o)) : NULL)
     /* op_pmstashstartu.op_pmstash is not refcounted */
  #define PmopSTASHPV_set(o,pv)	PmopSTASH_set((o), gv_stashpv(pv,GV_ADD))
  
  struct svop {
      BASEOP
      SV *	op_sv;
  };
  
  struct padop {
      BASEOP
      PADOFFSET	op_padix;
  };
  
  struct pvop {
      BASEOP
      char *	op_pv;
  };
  
  struct loop {
      BASEOP
      OP *	op_first; /* must be first */
      OP *	op_last;  /* must be second */
      OP *	op_redoop;
      OP *	op_nextop;
      OP *	op_lastop;
  };
  
  #define cUNOPx(o)	((UNOP*)(o))
  #define cUNOP_AUXx(o)	((UNOP_AUX*)(o))
  #define cBINOPx(o)	((BINOP*)(o))
  #define cLISTOPx(o)	((LISTOP*)(o))
  #define cLOGOPx(o)	((LOGOP*)(o))
  #define cPMOPx(o)	((PMOP*)(o))
  #define cSVOPx(o)	((SVOP*)(o))
  #define cPADOPx(o)	((PADOP*)(o))
  #define cPVOPx(o)	((PVOP*)(o))
  #define cCOPx(o)	((COP*)(o))
  #define cLOOPx(o)	((LOOP*)(o))
  #define cMETHOPx(o)	((METHOP*)(o))
  
  #define cUNOP		cUNOPx(PL_op)
  #define cUNOP_AUX	cUNOP_AUXx(PL_op)
  #define cBINOP		cBINOPx(PL_op)
  #define cLISTOP		cLISTOPx(PL_op)
  #define cLOGOP		cLOGOPx(PL_op)
  #define cPMOP		cPMOPx(PL_op)
  #define cSVOP		cSVOPx(PL_op)
  #define cPADOP		cPADOPx(PL_op)
  #define cPVOP		cPVOPx(PL_op)
  #define cCOP		cCOPx(PL_op)
  #define cLOOP		cLOOPx(PL_op)
  
  #define cUNOPo		cUNOPx(o)
  #define cUNOP_AUXo	cUNOP_AUXx(o)
  #define cBINOPo		cBINOPx(o)
  #define cLISTOPo	cLISTOPx(o)
  #define cLOGOPo		cLOGOPx(o)
  #define cPMOPo		cPMOPx(o)
  #define cSVOPo		cSVOPx(o)
  #define cPADOPo		cPADOPx(o)
  #define cPVOPo		cPVOPx(o)
  #define cCOPo		cCOPx(o)
  #define cLOOPo		cLOOPx(o)
  
  #define kUNOP		cUNOPx(kid)
  #define kUNOP_AUX	cUNOP_AUXx(kid)
  #define kBINOP		cBINOPx(kid)
  #define kLISTOP		cLISTOPx(kid)
  #define kLOGOP		cLOGOPx(kid)
  #define kPMOP		cPMOPx(kid)
  #define kSVOP		cSVOPx(kid)
  #define kPADOP		cPADOPx(kid)
  #define kPVOP		cPVOPx(kid)
  #define kCOP		cCOPx(kid)
  #define kLOOP		cLOOPx(kid)
  
  
  typedef enum {
      OPclass_NULL,     /*  0 */
      OPclass_BASEOP,   /*  1 */
      OPclass_UNOP,     /*  2 */
      OPclass_BINOP,    /*  3 */
      OPclass_LOGOP,    /*  4 */
      OPclass_LISTOP,   /*  5 */
      OPclass_PMOP,     /*  6 */
      OPclass_SVOP,     /*  7 */
      OPclass_PADOP,    /*  8 */
      OPclass_PVOP,     /*  9 */
      OPclass_LOOP,     /* 10 */
      OPclass_COP,      /* 11 */
      OPclass_METHOP,   /* 12 */
      OPclass_UNOP_AUX  /* 13 */
  } OPclass;
  
  
  #ifdef USE_ITHREADS
  #  define	cGVOPx_gv(o)	((GV*)PAD_SVl(cPADOPx(o)->op_padix))
  #  ifndef PERL_CORE
  #    define	IS_PADGV(v)	(v && isGV(v))
  #    define	IS_PADCONST(v) \
  	(v && (SvREADONLY(v) || (SvIsCOW(v) && !SvLEN(v))))
  #  endif
  #  define	cSVOPx_sv(v)	(cSVOPx(v)->op_sv \
  				 ? cSVOPx(v)->op_sv : PAD_SVl((v)->op_targ))
  #  define	cSVOPx_svp(v)	(cSVOPx(v)->op_sv \
  				 ? &cSVOPx(v)->op_sv : &PAD_SVl((v)->op_targ))
  #  define	cMETHOPx_rclass(v) PAD_SVl(cMETHOPx(v)->op_rclass_targ)
  #else
  #  define	cGVOPx_gv(o)	((GV*)cSVOPx(o)->op_sv)
  #  ifndef PERL_CORE
  #    define	IS_PADGV(v)	FALSE
  #    define	IS_PADCONST(v)	FALSE
  #  endif
  #  define	cSVOPx_sv(v)	(cSVOPx(v)->op_sv)
  #  define	cSVOPx_svp(v)	(&cSVOPx(v)->op_sv)
  #  define	cMETHOPx_rclass(v) (cMETHOPx(v)->op_rclass_sv)
  #endif
  
  #define IS_PADxV_OP(o)  \
        (OP_TYPE_IS_NN((o), OP_PADSV) \
      || OP_TYPE_IS_NN((o), OP_PADAV) \
      || OP_TYPE_IS_NN((o), OP_PADHV))
  #define	cMETHOPx_meth(v)	cSVOPx_sv(v)
  
  #define	cGVOP_gv		cGVOPx_gv(PL_op)
  #define	cGVOPo_gv		cGVOPx_gv(o)
  #define	kGVOP_gv		cGVOPx_gv(kid)
  #define cSVOP_sv		cSVOPx_sv(PL_op)
  #define cSVOPo_sv		cSVOPx_sv(o)
  #define kSVOP_sv		cSVOPx_sv(kid)
  
  #ifndef PERL_CORE
  #  define Nullop ((OP*)NULL)
  #endif
  
  /* See opnames.h for OA_ class and OP_IS_ tests */
  
  /* Op_REFCNT is a reference count at the head of each op tree: needed
   * since the tree is shared between threads, and between cloned closure
   * copies in the same thread. OP_REFCNT_LOCK/UNLOCK is used when modifying
   * this count.
   * The same mutex is used to protect the refcounts of the reg_trie_data
   * and reg_ac_data structures, which are shared between duplicated
   * regexes.
   */
  
  #ifdef USE_ITHREADS
  #  define OP_REFCNT_INIT		MUTEX_INIT(&PL_op_mutex)
  #  ifdef PERL_CORE
  #    define OP_REFCNT_LOCK		MUTEX_LOCK(&PL_op_mutex)
  #    define OP_REFCNT_UNLOCK		MUTEX_UNLOCK(&PL_op_mutex)
  #  else
  #    define OP_REFCNT_LOCK		op_refcnt_lock()
  #    define OP_REFCNT_UNLOCK		op_refcnt_unlock()
  #  endif
  #  define OP_REFCNT_TERM		MUTEX_DESTROY(&PL_op_mutex)
  #else
  #  define OP_REFCNT_INIT		NOOP
  #  define OP_REFCNT_LOCK		NOOP
  #  define OP_REFCNT_UNLOCK		NOOP
  #  define OP_REFCNT_TERM		NOOP
  #endif
  
  #define OpREFCNT_set(o,n)		((o)->op_targ = (n))
  #ifdef PERL_DEBUG_READONLY_OPS
  #  define OpREFCNT_inc(o)		Perl_op_refcnt_inc(aTHX_ o)
  #  define OpREFCNT_dec(o)		Perl_op_refcnt_dec(aTHX_ o)
  #else
  #  define OpREFCNT_inc(o)		((o) ? (++(o)->op_targ, (o)) : NULL)
  #  define OpREFCNT_dec(o)		(--(o)->op_targ)
  #endif
  
  /* flags used by Perl_load_module() */
  #define PERL_LOADMOD_DENY		0x1	/* no Module */
  #define PERL_LOADMOD_NOIMPORT		0x2	/* use Module () */
  #define PERL_LOADMOD_IMPORT_OPS		0x4	/* import arguments
  						   are passed as a sin-
  						   gle op tree, not a
  						   list of SVs */
  
  #define PERL_SUPPORT_STATIC_COP			/* for perlcc */
  
  #if defined(PERL_IN_PERLY_C) || defined(PERL_IN_OP_C) || defined(PERL_IN_TOKE_C)
  #define ref(o, type) doref(o, type, TRUE)
  #endif
  
  
  /* translation table attached to OP_TRANS/OP_TRANSR ops */
  
  typedef struct {
      Size_t size; /* number of entries in map[], not including final slot */
      short map[1]; /* Unwarranted chumminess */
  } OPtrans_map;
  
  
  /*
  =head1 Optree Manipulation Functions
  
  =for apidoc Am|OP*	|LINKLIST	|NN OP *o
  
  Given the root of an optree, link the tree in execution order using the
  C<op_next> pointers and return the first op executed.  If this has
  already been done, it will not be redone, and C<< o->op_next >> will be
  returned.  If C<< o->op_next >> is not already set, C<o> should be at
  least an C<UNOP>.
  
  =cut
  */
  
  #define LINKLIST(o) ((o)->op_next ? (o)->op_next : op_linklist((OP*)o))
  
  /* no longer used anywhere in core */
  #ifndef PERL_CORE
  #define cv_ckproto(cv, gv, p) \
     cv_ckproto_len_flags((cv), (gv), (p), (p) ? strlen(p) : 0, 0)
  #endif
  
  #ifdef PERL_CORE
  #  define my(o)	my_attrs((o), NULL)
  #  define OpTYPE_set(o,t) \
      STMT_START {                                 \
          OPCODE _type = (OPCODE)(t);              \
          o->op_type = _type;                      \
  	o->op_ppaddr = PL_ppaddr[_type];         \
      } STMT_END
  #endif
  
  #ifdef USE_REENTRANT_API
  #include "reentr.h"
  #endif
  
  #define NewOp(m,var,c,type)	\
  	(var = (type *) Perl_Slab_Alloc(aTHX_ c*sizeof(type)))
  #define NewOpSz(m,var,size)	\
  	(var = (OP *) Perl_Slab_Alloc(aTHX_ size))
  #define FreeOp(p) Perl_Slab_Free(aTHX_ p)
  
  /*
   * The per-CV op slabs consist of a header (the opslab struct) and a bunch
   * of space for allocating op slots, each of which consists of two pointers
   * followed by an op.  The first pointer points to the next op slot.  The
   * second points to the slab.  At the end of the slab is a null pointer,
   * so that slot->opslot_next - slot can be used to determine the size
   * of the op.
   *
   * Each CV can have multiple slabs; opslab_next points to the next slab, to
   * form a chain.  All bookkeeping is done on the first slab, which is where
   * all the op slots point.
   *
   * Freed ops are marked as freed and attached to the freed chain
   * via op_next pointers.
   *
   * When there is more than one slab, the second slab in the slab chain is
   * assumed to be the one with free space available.  It is used when allo-
   * cating an op if there are no freed ops available or big enough.
   */
  
  #ifdef PERL_CORE
  struct opslot {
      /* keep opslot_next first */
      OPSLOT *	opslot_next;		/* next slot */
      OPSLAB *	opslot_slab;		/* owner */
      OP		opslot_op;		/* the op itself */
  };
  
  struct opslab {
      OPSLOT *	opslab_first;		/* first op in this slab */
      OPSLAB *	opslab_next;		/* next slab */
      OP *	opslab_freed;		/* chain of freed ops */
      size_t	opslab_refcnt;		/* number of ops */
  # ifdef PERL_DEBUG_READONLY_OPS
      U16		opslab_size;		/* size of slab in pointers */
      bool	opslab_readonly;
  # endif
      OPSLOT	opslab_slots;		/* slots begin here */
  };
  
  # define OPSLOT_HEADER		STRUCT_OFFSET(OPSLOT, opslot_op)
  # define OPSLOT_HEADER_P	(OPSLOT_HEADER/sizeof(I32 *))
  # define OpSLOT(o)		(assert_(o->op_slabbed) \
  				 (OPSLOT *)(((char *)o)-OPSLOT_HEADER))
  # define OpSLAB(o)		OpSLOT(o)->opslot_slab
  # define OpslabREFCNT_dec(slab)      \
  	(((slab)->opslab_refcnt == 1) \
  	 ? opslab_free_nopad(slab)     \
  	 : (void)--(slab)->opslab_refcnt)
    /* Variant that does not null out the pads */
  # define OpslabREFCNT_dec_padok(slab) \
  	(((slab)->opslab_refcnt == 1)  \
  	 ? opslab_free(slab)		\
  	 : (void)--(slab)->opslab_refcnt)
  #endif
  
  struct block_hooks {
      U32	    bhk_flags;
      void    (*bhk_start)	(pTHX_ int full);
      void    (*bhk_pre_end)	(pTHX_ OP **seq);
      void    (*bhk_post_end)	(pTHX_ OP **seq);
      void    (*bhk_eval)		(pTHX_ OP *const saveop);
  };
  
  /*
  =head1 Compile-time scope hooks
  
  =for apidoc mx|U32|BhkFLAGS|BHK *hk
  Return the BHK's flags.
  
  =for apidoc mx|void *|BhkENTRY|BHK *hk|which
  Return an entry from the BHK structure.  C<which> is a preprocessor token
  indicating which entry to return.  If the appropriate flag is not set
  this will return C<NULL>.  The type of the return value depends on which
  entry you ask for.
  
  =for apidoc Amx|void|BhkENTRY_set|BHK *hk|which|void *ptr
  Set an entry in the BHK structure, and set the flags to indicate it is
  valid.  C<which> is a preprocessing token indicating which entry to set.
  The type of C<ptr> depends on the entry.
  
  =for apidoc Amx|void|BhkDISABLE|BHK *hk|which
  Temporarily disable an entry in this BHK structure, by clearing the
  appropriate flag.  C<which> is a preprocessor token indicating which
  entry to disable.
  
  =for apidoc Amx|void|BhkENABLE|BHK *hk|which
  Re-enable an entry in this BHK structure, by setting the appropriate
  flag.  C<which> is a preprocessor token indicating which entry to enable.
  This will assert (under -DDEBUGGING) if the entry doesn't contain a valid
  pointer.
  
  =for apidoc mx|void|CALL_BLOCK_HOOKS|which|arg
  Call all the registered block hooks for type C<which>.  C<which> is a
  preprocessing token; the type of C<arg> depends on C<which>.
  
  =cut
  */
  
  #define BhkFLAGS(hk)		((hk)->bhk_flags)
  
  #define BHKf_bhk_start	    0x01
  #define BHKf_bhk_pre_end    0x02
  #define BHKf_bhk_post_end   0x04
  #define BHKf_bhk_eval	    0x08
  
  #define BhkENTRY(hk, which) \
      ((BhkFLAGS(hk) & BHKf_ ## which) ? ((hk)->which) : NULL)
  
  #define BhkENABLE(hk, which) \
      STMT_START { \
  	BhkFLAGS(hk) |= BHKf_ ## which; \
  	assert(BhkENTRY(hk, which)); \
      } STMT_END
  
  #define BhkDISABLE(hk, which) \
      STMT_START { \
  	BhkFLAGS(hk) &= ~(BHKf_ ## which); \
      } STMT_END
  
  #define BhkENTRY_set(hk, which, ptr) \
      STMT_START { \
  	(hk)->which = ptr; \
  	BhkENABLE(hk, which); \
      } STMT_END
  
  #define CALL_BLOCK_HOOKS(which, arg) \
      STMT_START { \
  	if (PL_blockhooks) { \
  	    SSize_t i; \
  	    for (i = av_tindex(PL_blockhooks); i >= 0; i--) { \
  		SV *sv = AvARRAY(PL_blockhooks)[i]; \
  		BHK *hk; \
  		\
  		assert(SvIOK(sv)); \
  		if (SvUOK(sv)) \
  		    hk = INT2PTR(BHK *, SvUVX(sv)); \
  		else \
  		    hk = INT2PTR(BHK *, SvIVX(sv)); \
  		\
  		if (BhkENTRY(hk, which)) \
  		    BhkENTRY(hk, which)(aTHX_ arg); \
  	    } \
  	} \
      } STMT_END
  
  /* flags for rv2cv_op_cv */
  
  #define RV2CVOPCV_MARK_EARLY     0x00000001
  #define RV2CVOPCV_RETURN_NAME_GV 0x00000002
  #define RV2CVOPCV_RETURN_STUB    0x00000004
  #ifdef PERL_CORE /* behaviour of this flag is subject to change: */
  # define RV2CVOPCV_MAYBE_NAME_GV  0x00000008
  #endif
  #define RV2CVOPCV_FLAG_MASK      0x0000000f /* all of the above */
  
  #define op_lvalue(op,t) Perl_op_lvalue_flags(aTHX_ op,t,0)
  
  /* flags for op_lvalue_flags */
  
  #define OP_LVALUE_NO_CROAK 1
  
  /*
  =head1 Custom Operators
  
  =for apidoc Am|U32|XopFLAGS|XOP *xop
  Return the XOP's flags.
  
  =for apidoc Am||XopENTRY|XOP *xop|which
  Return a member of the XOP structure.  C<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 C<which>.  This macro evaluates its arguments more than
  once.  If you are using C<Perl_custom_op_xop> to retreive a
  C<XOP *> from a C<OP *>, use the more efficient L</XopENTRYCUSTOM> instead.
  
  =for apidoc Am||XopENTRYCUSTOM|const OP *o|which
  Exactly like C<XopENTRY(XopENTRY(Perl_custom_op_xop(aTHX_ o), which)> but more
  efficient.  The C<which> parameter is identical to L</XopENTRY>.
  
  =for apidoc Am|void|XopENTRY_set|XOP *xop|which|value
  Set a member of the XOP structure.  C<which> is a cpp token
  indicating which entry to set.  See L<perlguts/"Custom Operators">
  for details about the available members and how
  they are used.  This macro evaluates its argument
  more than once.
  
  =for apidoc Am|void|XopDISABLE|XOP *xop|which
  Temporarily disable a member of the XOP, by clearing the appropriate flag.
  
  =for apidoc Am|void|XopENABLE|XOP *xop|which
  Reenable a member of the XOP which has been disabled.
  
  =cut
  */
  
  struct custom_op {
      U32		    xop_flags;    
      const char	   *xop_name;
      const char	   *xop_desc;
      U32		    xop_class;
      void	  (*xop_peep)(pTHX_ OP *o, OP *oldop);
      const char	   *xop_type;
  };
  
  /* return value of Perl_custom_op_get_field, similar to void * then casting but
     the U32 doesn't need truncation on 64 bit platforms in the caller, also
     for easier macro writing */
  typedef union {
      const char	   *xop_name;
      const char	   *xop_desc;
      U32		    xop_class;
      void	  (*xop_peep)(pTHX_ OP *o, OP *oldop);
      XOP            *xop_ptr;
      const char	   *xop_type;
  } XOPRETANY;
  
  #define XopFLAGS(xop) ((xop)->xop_flags)
  
  #define XOPf_xop_name	0x01
  #define XOPf_xop_desc	0x02
  #define XOPf_xop_class	0x04
  #define XOPf_xop_peep	0x08
  #define XOPf_xop_type	0x10
  
  /* used by Perl_custom_op_get_field for option checking */
  typedef enum {
      XOPe_xop_ptr = 0, /* just get the XOP *, don't look inside it */
      XOPe_xop_name = XOPf_xop_name,
      XOPe_xop_desc = XOPf_xop_desc,
      XOPe_xop_class = XOPf_xop_class,
      XOPe_xop_peep = XOPf_xop_peep,
      XOPe_xop_type = XOPf_xop_type
  } xop_flags_enum;
  
  #define XOPd_xop_name	PL_op_name[OP_CUSTOM]
  #define XOPd_xop_desc	PL_op_desc[OP_CUSTOM]
  #define XOPd_xop_class	OA_BASEOP
  #define XOPd_xop_peep	((Perl_cpeep_t)0)
  #define XOPd_xop_type	PL_op_type[OP_CUSTOM]
  
  #define XopENTRY_set(xop, which, to) \
      STMT_START { \
  	(xop)->which = (to); \
  	(xop)->xop_flags |= XOPf_ ## which; \
      } STMT_END
  
  #define XopENTRY(xop, which) \
      ((XopFLAGS(xop) & XOPf_ ## which) ? (xop)->which : XOPd_ ## which)
  
  #define XopENTRYCUSTOM(o, which) \
      (Perl_custom_op_get_field(aTHX_ (o), XOPe_ ## which).which)
  
  #define XopDISABLE(xop, which) ((xop)->xop_flags &= ~XOPf_ ## which)
  #define XopENABLE(xop, which) \
      STMT_START { \
  	(xop)->xop_flags |= XOPf_ ## which; \
  	assert(XopENTRY(xop, which)); \
      } STMT_END
  
  #define Perl_custom_op_xop(x) \
      (Perl_custom_op_get_field(x, XOPe_xop_ptr).xop_ptr)
  
  /*
  =head1 Optree Manipulation Functions
  
  =for apidoc Am|const char *|OP_NAME|OP *o
  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.
  
  =for apidoc Am|const char *|OP_DESC|OP *o
  Return a short description of the provided OP.
  
  =for apidoc Am|U32|OP_CLASS|OP *o
  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 C<PL_opargs>, which does not always accurately reflect the type used;
  in v5.26 onwards, see also the function C<L</op_class>> which can do a better
  job of determining the used type.
  
  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 C<OA_>* constants from F<op.h>.
  
  =for apidoc Am|bool|OP_TYPE_IS|OP *o|Optype type
  Returns true if the given OP is not a C<NULL> pointer
  and if it is of the given type.
  
  The negation of this macro, C<OP_TYPE_ISNT> is also available
  as well as C<OP_TYPE_IS_NN> and C<OP_TYPE_ISNT_NN> which elide
  the NULL pointer check.
  
  =for apidoc Am|bool|OP_TYPE_IS_OR_WAS|OP *o|Optype type
  Returns true if the given OP is not a NULL pointer and
  if it is of the given type or used to be before being
  replaced by an OP of type OP_NULL.
  
  The negation of this macro, C<OP_TYPE_ISNT_AND_WASNT>
  is also available as well as C<OP_TYPE_IS_OR_WAS_NN>
  and C<OP_TYPE_ISNT_AND_WASNT_NN> which elide
  the C<NULL> pointer check.
  
  =for apidoc Am|bool|OpHAS_SIBLING|OP *o
  Returns true if C<o> has a sibling
  
  =for apidoc Am|OP*|OpSIBLING|OP *o
  Returns the sibling of C<o>, or C<NULL> if there is no sibling
  
  =for apidoc Am|void|OpMORESIB_set|OP *o|OP *sib
  Sets the sibling of C<o> to the non-zero value C<sib>. See also C<L</OpLASTSIB_set>>
  and C<L</OpMAYBESIB_set>>. For a higher-level interface, see
  C<L</op_sibling_splice>>.
  
  =for apidoc Am|void|OpLASTSIB_set|OP *o|OP *parent
  Marks C<o> as having no further siblings and marks
  o as having the specified parent. See also C<L</OpMORESIB_set>> and
  C<OpMAYBESIB_set>. For a higher-level interface, see
  C<L</op_sibling_splice>>.
  
  =for apidoc Am|void|OpMAYBESIB_set|OP *o|OP *sib|OP *parent
  Conditionally does C<OpMORESIB_set> or C<OpLASTSIB_set> depending on whether
  C<sib> is non-null. For a higher-level interface, see C<L</op_sibling_splice>>.
  
  =cut
  */
  
  #define OP_NAME(o) (((OP*)o)->op_type == OP_CUSTOM \
                      ? XopENTRYCUSTOM((OP*)(o), xop_name) \
  		    : PL_op_name[((OP*)o)->op_type])
  #define OP_DESC(o) ((o)->op_type == OP_CUSTOM \
                      ? XopENTRYCUSTOM(o, xop_desc) \
  		    : PL_op_desc[(o)->op_type])
  #define OP_CLASS(o) ((o)->op_type == OP_CUSTOM \
  		     ? XopENTRYCUSTOM(o, xop_class) \
  		     : (PL_opargs[(o)->op_type] & OA_CLASS_MASK))
  #define OP_TYPE_STR(o) ((o)->op_type == OP_CUSTOM \
                      ? XopENTRYCUSTOM(o, xop_type) \
  		    : PL_op_type[(o)->op_type])
  
  #define OP_TYPE_IS(o, type)      ((o) && (o)->op_type == (type))
  #define OP_TYPE_IS_NN(o, type)   ((o)->op_type == (type))
  #define OP_TYPE_ISNT(o, type)    ((o) && (o)->op_type != (type))
  #define OP_TYPE_ISNT_NN(o, type) ((o)->op_type != (type))
  
  #define OP_TYPE_WAS_NN(o, type) \
      ( (o)->op_type == OP_NULL && (o)->op_targ == (type) )
  #define OP_TYPE_IS_OR_WAS_NN(o, type) \
      ( ((o)->op_type == OP_NULL \
         ? (o)->op_targ \
         : (o)->op_type) \
        == (type) )
  #define OP_TYPE_IS_OR_WAS(o, type) \
      ( (o) && OP_TYPE_IS_OR_WAS_NN(o, type) )
  #define OP_TYPE_ISNT_AND_WASNT_NN(o, type) \
      ( ((o)->op_type == OP_NULL \
         ? (o)->op_targ \
         : (o)->op_type) \
        != (type) )
  #define OP_TYPE_ISNT_AND_WASNT(o, type) \
      ( (o) && OP_TYPE_ISNT_AND_WASNT_NN(o, type) )
  #define NO_OP_TYPE_OR_WASNT(o, type) \
      ( !(o) || OP_TYPE_ISNT_AND_WASNT_NN(o, type) )
  
  #define OpTYPECHECKED(o)	(0 + (o)->op_typechecked)
  #define OpRETTYPE(o)		(U8)(0 + (o)->op_rettype)
  #define OpRETTYPE_set(o, type)	(o)->op_rettype = (U8)(type)
  
  #define OpNEXT(o)    (o)->op_next
  #define OpFIRST(o)   cUNOPx(o)->op_first
  #define OpLAST(o)    cBINOPx(o)->op_last
  #define OpOTHER(o)   cLOGOPx(o)->op_other
  
  #define OpHAS_SIBLING(o)	(cBOOL((o)->op_moresib))
  #define OpSIBLING(o)		(0 + (o)->op_moresib ? (o)->op_sibparent : NULL)
  #define OpMORESIB_set(o, sib) ((o)->op_moresib = 1, (o)->op_sibparent = (sib))
  #define OpLASTSIB_set(o, parent) \
         ((o)->op_moresib = 0, (o)->op_sibparent = (parent))
  #define OpMAYBESIB_set(o, sib, parent) \
         ((o)->op_sibparent = ((o)->op_moresib = cBOOL(sib)) ? (OP*)(sib) : (parent))
  
  #if !defined(PERL_CORE) && !defined(PERL_EXT)
  /* for backwards compatibility only */
  #  define OP_SIBLING(o)		OpSIBLING(o)
  #endif
  
  #define newATTRSUB(f, o, p, a, b) Perl_newATTRSUB_x(aTHX_  f, o, p, a, b, FALSE)
  #define newSUB(f, o, p, b)	newATTRSUB((f), (o), (p), NULL, (b))
  
  /*
  =head1 Hook manipulation
  */
  
  #ifdef USE_ITHREADS
  #  define OP_CHECK_MUTEX_INIT		MUTEX_INIT(&PL_check_mutex)
  #  define OP_CHECK_MUTEX_LOCK		MUTEX_LOCK(&PL_check_mutex)
  #  define OP_CHECK_MUTEX_UNLOCK		MUTEX_UNLOCK(&PL_check_mutex)
  #  define OP_CHECK_MUTEX_TERM		MUTEX_DESTROY(&PL_check_mutex)
  #else
  #  define OP_CHECK_MUTEX_INIT		NOOP
  #  define OP_CHECK_MUTEX_LOCK		NOOP
  #  define OP_CHECK_MUTEX_UNLOCK		NOOP
  #  define OP_CHECK_MUTEX_TERM		NOOP
  #endif
  
  
  /* Stuff for OP_MULTDEREF/pp_multideref. */
  
  /* actions */
  
  /* Load another word of actions/flag bits. Must be 0 */
  #define MDEREF_reload                       0
  
  #define MDEREF_AV_pop_rv2av_aelem           1
  #define MDEREF_AV_gvsv_vivify_rv2av_aelem   2
  #define MDEREF_AV_padsv_vivify_rv2av_aelem  3
  #define MDEREF_AV_vivify_rv2av_aelem        4
  #define MDEREF_AV_padav_aelem               5
  #define MDEREF_AV_gvav_aelem                6
  
  #define MDEREF_HV_pop_rv2hv_helem           8
  #define MDEREF_HV_gvsv_vivify_rv2hv_helem   9
  #define MDEREF_HV_padsv_vivify_rv2hv_helem 10
  #define MDEREF_HV_vivify_rv2hv_helem       11
  #define MDEREF_HV_padhv_helem              12
  #define MDEREF_HV_gvhv_helem               13
  
  #define MDEREF_ACTION_MASK                0xf
  
  /* key / index type */
  
  #define MDEREF_INDEX_none   0x00 /* run external ops to generate index */
  #define MDEREF_INDEX_const  0x10 /* index is const PV/UV */
  #define MDEREF_INDEX_padsv  0x20 /* index is lexical var */
  #define MDEREF_INDEX_gvsv   0x30 /* index is GV */
  
  /* (MDEREF_INDEX_const|MDEREF_INDEX_padsv|MDEREF_INDEX_gvsv) */
  #define MDEREF_INDEX_MASK   0x30
  
  /* bit flags */
  
  #define MDEREF_INDEX_uoob   0x40 /* index needs no out-of-bounds check */
  #define MDEREF_FLAG_last    0x80 /* the last [ah]elem; PL_op flags apply */
  
  #define MDEREF_MASK        0x10F
  #define MDEREF_SHIFT           8
  
  /* Stuff for OP_SIGNATURE/pp_signature. */
  
  /* actions */
  
  #define SIGNATURE_reload              0 /* load another word of actions:
                                             must be zero */
  #define SIGNATURE_end                 1 /* finish */
  #define SIGNATURE_padintro            2 /* set new pad base index and range */
  #define SIGNATURE_arg                 3 /* mandatory arg */
  #define SIGNATURE_arg_default_none    4 /* $=  */
  #define SIGNATURE_arg_default_undef   5 /* $arg?,  arg with default of undef */
  #define SIGNATURE_arg_default_0       6 /* $arg=0, arg with default of 0 */
  #define SIGNATURE_arg_default_1       7 /* arg with default of 1 */
  #define SIGNATURE_arg_default_iv      8 /* arg with default of an IV */
  #define SIGNATURE_arg_default_const   9 /* arg with default of a const */
  #define SIGNATURE_arg_default_padsv  10 /* arg with default of a lex var */
  #define SIGNATURE_arg_default_gvsv   11 /* arg with default of a pkg var */
  #define SIGNATURE_arg_default_op     12 /* arg with default which is a
                                             general expression whose ops follow
                                             the signature op */
  #define SIGNATURE_array              13 /* @array parameter, slurpy or ref */
  #define SIGNATURE_hash               14 /* %hash parameter, slurpy or ref */
  
  #define SIGNATURE_ACTION_MASK       0xf
  
  /* bit flags */
  
  #define SIGNATURE_FLAG_skip        0x10  /* placeholder param */
  #define SIGNATURE_FLAG_ref         0x20
  
  #define SIGNATURE_MASK             0x3F
  #define SIGNATURE_SHIFT               6
  
  #if defined(PERL_IN_DOOP_C) || defined(PERL_IN_PP_C)
  #   define FATAL_ABOVE_FF_MSG                                       \
        "Use of strings with code points over 0xFF as arguments to "  \
        "%s operator is not allowed"
  #  define DEPRECATED_ABOVE_FF_MSG                                   \
        "Use of strings with code points over 0xFF as arguments to "  \
        "%s operator is deprecated. This will be a fatal error in "   \
        "Perl 5.32"
  #endif
  
  /* See L<perlapi/method_field_type> */
  /* Corresponding to has $field, @field or %field */
  #define METHOD_FIELD_NONE   0
  #define METHOD_FIELD_SCALAR 1
  #define METHOD_FIELD_ARRAY  2
  #define METHOD_FIELD_HASH   3
  
  /*
   * ex: set ts=8 sts=4 sw=4 et:
   */
  