op.h

/*    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.
 *
 *			See the comments in S_clear_yystack() for more
 *			details on the following three flags:
 *
 *	op_latefree	tell op_free() to clear this op (and free any kids)
 *			but not yet deallocate the struct. This means that
 *			the op may be safely op_free()d multiple times
 *	op_latefreed	an op_latefree op has been op_free()d
 *	op_attached	this op (sub)tree has been attached to a CV
 *
 *	op_spare	three spare bits!
 *	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"

#define OPCODE U16

#ifdef PERL_MAD
#  define MADPROP_IN_BASEOP	MADPROP*	op_madprop;
#else
#  define MADPROP_IN_BASEOP
#endif

typedef PERL_BITFIELD16 Optype;

#ifdef BASEOP_DEFINITION
#define BASEOP BASEOP_DEFINITION
#else
#define BASEOP				\
    OP*		op_next;		\
    OP*		op_sibling;		\
    OP*		(*op_ppaddr)(pTHX);	\
    MADPROP_IN_BASEOP			\
    PADOFFSET	op_targ;		\
    PERL_BITFIELD16 op_type:9;		\
    PERL_BITFIELD16 op_opt:1;		\
    PERL_BITFIELD16 op_latefree:1;	\
    PERL_BITFIELD16 op_latefreed:1;	\
    PERL_BITFIELD16 op_attached:1;	\
    PERL_BITFIELD16 op_spare:3;		\
    U8		op_flags;		\
    U8		op_private;
#endif

/* If op_type:9 is changed to :10, also change PUSHEVAL in cop.h.
   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 OP_GIMME(op,dfl) \
	(((op)->op_flags & OPf_WANT) == OPf_WANT_VOID   ? G_VOID   : \
	 ((op)->op_flags & OPf_WANT) == OPf_WANT_SCALAR ? G_SCALAR : \
	 ((op)->op_flags & OPf_WANT) == OPf_WANT_LIST   ? G_ARRAY   : \
	 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. */
#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. */
				/*  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_ENTERSUB || OP_NULL, saw a "do". */
				/*  On OP_EXISTS, treat av as av, not avhv.  */
				/*  On OP_(ENTER|LEAVE)EVAL, don't clear $@ */
				/*  On pushre, rx is used as part of split, e.g. split " " */
				/*  On regcomp, "use re 'eval'" was in scope */
				/*  On OP_READLINE, was <$filehandle> */
				/*  On RV2[ACGHS]V, don't create GV--in
				    defined()*/
				/*  On OP_DBSTATE, indicates breakpoint
				 *    (runtime property) */
				/*  On OP_AELEMFAST, indicates pad var */
				/*  On OP_REQUIRE, was seen as CORE::require */
				/*  On OP_ENTERWHEN, there's no condition */
				/*  On OP_BREAK, an implicit break */
				/*  On OP_SMARTMATCH, an implicit smartmatch */
				/*  On OP_ANONHASH and OP_ANONLIST, create a
				    reference to the new anon hash or array */
				/*  On OP_ENTER, store caller context */
				/*  On OP_HELEM 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, use Perl glob function */

/* 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 GIMME \
	  (PL_op->op_flags & OPf_WANT					\
	   ? ((PL_op->op_flags & OPf_WANT) == OPf_WANT_LIST		\
	      ? G_ARRAY							\
	      : G_SCALAR)						\
	   : dowantarray())

/* NOTE: OP_NEXTSTATE and OP_DBSTATE (i.e. COPs) carry lower
 * bits of PL_hints in op_private */

/* Private for lvalues */
#define OPpLVAL_INTRO	128	/* Lvalue must be localized or lvalue sub */

/* Private for OP_LEAVE, OP_LEAVESUB, OP_LEAVESUBLV and OP_LEAVEWRITE */
#define OPpREFCOUNTED		64	/* op_targ carries a refcount */

/* Private for OP_AASSIGN */
#define OPpASSIGN_COMMON	64	/* Left & right have syms in common. */

/* Private for OP_SASSIGN */
#define OPpASSIGN_BACKWARDS	64	/* Left & right switched. */
#define OPpASSIGN_CV_TO_GV	128	/* Possible optimisation for constants. */

/* Private for OP_MATCH and OP_SUBST{,CONST} */
#define OPpRUNTIME		64	/* Pattern coming in on the stack */

/* Private for OP_TRANS */
#define OPpTRANS_FROM_UTF	1
#define OPpTRANS_TO_UTF		2
#define OPpTRANS_IDENTICAL	4	/* right side is same as left */
#define OPpTRANS_SQUASH		8
    /* 16 is used for OPpTARGET_MY */
#define OPpTRANS_COMPLEMENT	32
#define OPpTRANS_GROWS		64
#define OPpTRANS_DELETE		128
#define OPpTRANS_ALL	(OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF|OPpTRANS_IDENTICAL|OPpTRANS_SQUASH|OPpTRANS_COMPLEMENT|OPpTRANS_GROWS|OPpTRANS_DELETE)

/* Private for OP_REPEAT */
#define OPpREPEAT_DOLIST	64	/* List replication. */

/* Private for OP_RV2GV, OP_RV2SV, OP_AELEM, OP_HELEM, OP_PADSV */
#define OPpDEREF		(32|64)	/* autovivify: Want ref to something: */
#define OPpDEREF_AV		32	/*   Want ref to AV. */
#define OPpDEREF_HV		64	/*   Want ref to HV. */
#define OPpDEREF_SV		(32|64)	/*   Want ref to SV. */
/* Private for OP_RV2SV, OP_RV2AV, OP_RV2AV */
#define OPpDEREFed		4	/* prev op was OPpDEREF */
  /* OP_ENTERSUB only */
#define OPpENTERSUB_DB		16	/* Debug subroutine. */
#define OPpENTERSUB_HASTARG	32	/* Called from OP tree. */
#define OPpENTERSUB_NOMOD	64	/* Immune to op_lvalue() for :attrlist. */
  /* OP_ENTERSUB and OP_RV2CV only */
#define OPpENTERSUB_AMPER	8	/* Used & form to call. */
#define OPpENTERSUB_NOPAREN	128	/* bare sub call (without parens) */
#define OPpENTERSUB_INARGS	4	/* Lval used as arg to a sub. */
  /* OP_GV only */
#define OPpEARLY_CV		32	/* foo() called before sub foo was parsed */
  /* OP_?ELEM only */
#define OPpLVAL_DEFER		16	/* Defer creation of array/hash elem */
  /* OP_RV2?V, OP_GVSV, OP_ENTERITER only */
#define OPpOUR_INTRO		16	/* Variable was in an our() */
  /* OP_RV2[AGH]V, OP_PAD[AH]V, OP_[AH]ELEM */
#define OPpMAYBE_LVSUB		8	/* We might be an lvalue to return */
  /* OP_PADSV only */
#define OPpPAD_STATE		16	/* is a "state" pad */
  /* for OP_RV2?V, lower bits carry hints (currently only HINT_STRICT_REFS) */

  /* OP_RV2GV only */
#define OPpDONT_INIT_GV		4	/* Call gv_fetchpv with GV_NOINIT */
/* (Therefore will return whatever is currently in the symbol table, not
   guaranteed to be a PVGV)  */

  /* OP_RV2CV only */
#define OPpMAY_RETURN_CONSTANT	1	/* If a constant sub, return the constant */

/* Private for OPs with TARGLEX */
  /* (lower bits may carry MAXARG) */
#define OPpTARGET_MY		16	/* Target is PADMY. */

/* Private for OP_ENTERITER and OP_ITER */
#define OPpITER_REVERSED	4	/* for (reverse ...) */
#define OPpITER_DEF		8	/* for $_ or for my $_ */

/* Private for OP_CONST */
#define	OPpCONST_NOVER		2	/* no 6; */
#define	OPpCONST_SHORTCIRCUIT	4	/* eg the constant 5 in (5 || foo) */
#define	OPpCONST_STRICT		8	/* bareword subject to strict 'subs' */
#define OPpCONST_ENTERED	16	/* Has been entered as symbol. */
#define OPpCONST_ARYBASE	32	/* Was a $[ translated to constant. */
#define OPpCONST_BARE		64	/* Was a bare word (filehandle?). */
#define OPpCONST_WARNING	128	/* Was a $^W translated to constant. */

/* Private for OP_FLIP/FLOP */
#define OPpFLIP_LINENUM		64	/* Range arg potentially a line num. */

/* Private for OP_LIST */
#define OPpLIST_GUESSED		64	/* Guessed that pushmark was needed. */

/* Private for OP_DELETE */
#define OPpSLICE		64	/* Operating on a list of keys */
/* Also OPpLVAL_INTRO (128) */

/* Private for OP_EXISTS */
#define OPpEXISTS_SUB		64	/* Checking for &sub, not {} or [].  */

/* Private for OP_SORT */
#define OPpSORT_NUMERIC		1	/* Optimized away { $a <=> $b } */
#define OPpSORT_INTEGER		2	/* Ditto while under "use integer" */
#define OPpSORT_REVERSE		4	/* Reversed sort */
#define OPpSORT_INPLACE		8	/* sort in-place; eg @a = sort @a */
#define OPpSORT_DESCEND		16	/* Descending sort */
#define OPpSORT_QSORT		32	/* Use quicksort (not mergesort) */
#define OPpSORT_STABLE		64	/* Use a stable algorithm */

/* Private for OP_REVERSE */
#define OPpREVERSE_INPLACE	8	/* reverse in-place (@a = reverse @a) */

/* Private for OP_OPEN and OP_BACKTICK */
#define OPpOPEN_IN_RAW		16	/* binmode(F,":raw") on input fh */
#define OPpOPEN_IN_CRLF		32	/* binmode(F,":crlf") on input fh */
#define OPpOPEN_OUT_RAW		64	/* binmode(F,":raw") on output fh */
#define OPpOPEN_OUT_CRLF	128	/* binmode(F,":crlf") on output fh */

/* Private for OP_EXIT, HUSH also for OP_DIE */
#define OPpHUSH_VMSISH		64	/* hush DCL exit msg vmsish mode*/
#define OPpEXIT_VMSISH		128	/* exit(0) vs. exit(1) vmsish mode*/

/* Private for OP_FTXXX */
#define OPpFT_ACCESS		2	/* use filetest 'access' */
#define OPpFT_STACKED		4	/* stacked filetest, as in "-f -x $f" */

/* Private for OP_(MAP|GREP)(WHILE|START) */
#define OPpGREP_LEX		2	/* iterate over lexical $_ */
    
/* Private for OP_ENTEREVAL */
#define OPpEVAL_HAS_HH		2	/* Does it have a copy of %^H */
    
struct op {
    BASEOP
};

struct unop {
    BASEOP
    OP *	op_first;
};

struct binop {
    BASEOP
    OP *	op_first;
    OP *	op_last;
};

struct logop {
    BASEOP
    OP *	op_first;
    OP *	op_other;
};

struct listop {
    BASEOP
    OP *	op_first;
    OP *	op_last;
};

struct pmop {
    BASEOP
    OP *	op_first;
    OP *	op_last;
#ifdef USE_ITHREADS
    IV          op_pmoffset;
#else
    REGEXP *    op_pmregexp;            /* compiled expression */
#endif
    U32         op_pmflags;
    union {
	OP *	op_pmreplroot;		/* For OP_SUBST */
#ifdef USE_ITHREADS
	PADOFFSET  op_pmtargetoff;	/* For OP_PUSHRE */
#else
	GV *	op_pmtargetgv;
#endif
    }	op_pmreplrootu;
    union {
	OP *	op_pmreplstart;	/* Only used in OP_SUBST */
#ifdef USE_ITHREADS
	char *	op_pmstashpv;	/* Only used in OP_MATCH, with PMf_ONCE set */
#else
	HV *	op_pmstash;
#endif
    }		op_pmstashstartu;
};

#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
   &PL_sv_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

/* Leave some space, so future bit allocations can go either in the shared or
 * unshared area without affecting binary compatibility */
#define PMf_BASE_SHIFT (_RXf_PMf_SHIFT_NEXT+6)

/* 'use re "taint"' in scope: taint $1 etc. if target tainted */
#define PMf_RETAINT	(1<<(PMf_BASE_SHIFT+0))

/* 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	(1<<(PMf_BASE_SHIFT+1))

/* replacement contains variables */
#define PMf_MAYBE_CONST (1<<(PMf_BASE_SHIFT+2))

/* PMf_ONCE has matched successfully.  Not used under threading. */
#define PMf_USED        (1<<(PMf_BASE_SHIFT+3))

/* subst replacement is constant */
#define PMf_CONST	(1<<(PMf_BASE_SHIFT+4))

/* keep 1st runtime pattern forever */
#define PMf_KEEP	(1<<(PMf_BASE_SHIFT+5))

#define PMf_GLOBAL	(1<<(PMf_BASE_SHIFT+6))	/* pattern had a g modifier */

/* don't reset pos() if //g fails */
#define PMf_CONTINUE	(1<<(PMf_BASE_SHIFT+7))

/* evaluating replacement as expr */
#define PMf_EVAL	(1<<(PMf_BASE_SHIFT+8))

/* Return substituted string instead of modifying it. */
#define PMf_NONDESTRUCT	(1<<(PMf_BASE_SHIFT+9))

#if PMf_BASE_SHIFT+9 > 31
#   error Too many PMf_ bits used.  See above and regnodes.h for any spare in middle
#endif

#ifdef USE_ITHREADS

#  define PmopSTASHPV(o)						\
    (((o)->op_pmflags & PMf_ONCE) ? (o)->op_pmstashstartu.op_pmstashpv : NULL)
#  if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
#    define PmopSTASHPV_set(o,pv)	({				\
	assert((o)->op_pmflags & PMf_ONCE);				\
	((o)->op_pmstashstartu.op_pmstashpv = savesharedpv(pv));	\
    })
#  else
#    define PmopSTASHPV_set(o,pv)					\
    ((o)->op_pmstashstartu.op_pmstashpv = savesharedpv(pv))
#  endif
#  define PmopSTASH(o)		(PmopSTASHPV(o) \
				 ? gv_stashpv((o)->op_pmstashstartu.op_pmstashpv,GV_ADD) : NULL)
#  define PmopSTASH_set(o,hv)	PmopSTASHPV_set(o, ((hv) ? HvNAME_get(hv) : NULL))
#  define PmopSTASH_free(o)	PerlMemShared_free(PmopSTASHPV(o))

#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
#  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))
/* Note that if this becomes non-empty, then S_forget_pmop in op.c will need
   changing */
#  define PmopSTASH_free(o)    
#endif

struct svop {
    BASEOP
    SV *	op_sv;
};

struct padop {
    BASEOP
    PADOFFSET	op_padix;
};

struct pvop {
    BASEOP
    char *	op_pv;
};

struct loop {
    BASEOP
    OP *	op_first;
    OP *	op_last;
    OP *	op_redoop;
    OP *	op_nextop;
    OP *	op_lastop;
};

#define cUNOPx(o)	((UNOP*)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 cUNOP		cUNOPx(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 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 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)


#ifdef USE_ITHREADS
#  define	cGVOPx_gv(o)	((GV*)PAD_SVl(cPADOPx(o)->op_padix))
#  define	IS_PADGV(v)	(v && SvTYPE(v) == SVt_PVGV && isGV_with_GP(v) \
				 && GvIN_PAD(v))
#  define	IS_PADCONST(v)	(v && SvREADONLY(v))
#  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))
#else
#  define	cGVOPx_gv(o)	((GV*)cSVOPx(o)->op_sv)
#  define	IS_PADGV(v)	FALSE
#  define	IS_PADCONST(v)	FALSE
#  define	cSVOPx_sv(v)	(cSVOPx(v)->op_sv)
#  define	cSVOPx_svp(v)	(&cSVOPx(v)->op_sv)
#endif

#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

/* Lowest byte-and-a-bit of PL_opargs */
#define OA_MARK 1
#define OA_FOLDCONST 2
#define OA_RETSCALAR 4
#define OA_TARGET 8
#define OA_TARGLEX 16
#define OA_OTHERINT 32
#define OA_DANGEROUS 64
#define OA_DEFGV 128

/* The next 4 bits encode op class information */
#define OCSHIFT 8

#define OA_CLASS_MASK (15 << OCSHIFT)

#define OA_BASEOP (0 << OCSHIFT)
#define OA_UNOP (1 << OCSHIFT)
#define OA_BINOP (2 << OCSHIFT)
#define OA_LOGOP (3 << OCSHIFT)
#define OA_LISTOP (4 << OCSHIFT)
#define OA_PMOP (5 << OCSHIFT)
#define OA_SVOP (6 << OCSHIFT)
#define OA_PADOP (7 << OCSHIFT)
#define OA_PVOP_OR_SVOP (8 << OCSHIFT)
#define OA_LOOP (9 << OCSHIFT)
#define OA_COP (10 << OCSHIFT)
#define OA_BASEOP_OR_UNOP (11 << OCSHIFT)
#define OA_FILESTATOP (12 << OCSHIFT)
#define OA_LOOPEXOP (13 << OCSHIFT)

#define OASHIFT 12

/* Remaining nybbles of PL_opargs */
#define OA_SCALAR 1
#define OA_LIST 2
#define OA_AVREF 3
#define OA_HVREF 4
#define OA_CVREF 5
#define OA_FILEREF 6
#define OA_SCALARREF 7
#define OA_OPTIONAL 8

/* 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	/* use Module (...) */

#if defined(PERL_IN_PERLY_C) || defined(PERL_IN_OP_C)
#define ref(o, type) doref(o, type, TRUE)
#endif

/*
=head1 Optree Manipulation Functions

=for apidoc Am|OP*|LINKLIST|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, I<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((cv), (gv), (p), (p) ? strlen(p) : 0)
#endif

#ifdef PERL_CORE
#  define my(o)	my_attrs((o), NULL)
#endif

#ifdef USE_REENTRANT_API
#include "reentr.h"
#endif

#if defined(PL_OP_SLAB_ALLOC)
#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)
#else
#define NewOp(m, var, c, type)	\
	(var = (MEM_WRAP_CHECK_(c,type) \
	 (type*)PerlMemShared_calloc(c, sizeof(type))))
#define NewOpSz(m, var, size)	\
	(var = (OP*)PerlMemShared_calloc(1, size))
#define FreeOp(p) PerlMemShared_free(p)
#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. I<which> is a preprocessor token
indicating which entry to return. If the appropriate flag is not set
this will return NULL. The type of the return value depends on which
entry you ask for.

=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. I<which> is a preprocessing token indicating which entry to set.
The type of I<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. I<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. I<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 I<which>. I<which> is a
preprocessing token; the type of I<arg> depends on I<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) { \
	    I32 i; \
	    for (i = av_len(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

/*
=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. I<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 I<which>.

=for apidoc Am|void|XopENTRY_set|XOP *xop|which|value
Set a member of the XOP structure. I<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.

=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);
};

#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 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 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 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

/*
=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 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.

=cut
*/

#define OP_NAME(o) ((o)->op_type == OP_CUSTOM \
		    ? XopENTRY(Perl_custom_op_xop(aTHX_ o), xop_name) \
		    : PL_op_name[(o)->op_type])
#define OP_DESC(o) ((o)->op_type == OP_CUSTOM \
		    ? XopENTRY(Perl_custom_op_xop(aTHX_ o), xop_desc) \
		    : PL_op_desc[(o)->op_type])
#define OP_CLASS(o) ((o)->op_type == OP_CUSTOM \
		     ? XopENTRY(Perl_custom_op_xop(aTHX_ o), xop_class) \
		     : (PL_opargs[(o)->op_type] & OA_CLASS_MASK))

#define newSUB(f, o, p, b)	Perl_newATTRSUB(aTHX_ (f), (o), (p), NULL, (b))

#ifdef PERL_MAD
#  define MAD_NULL 1
#  define MAD_PV 2
#  define MAD_OP 3
#  define MAD_SV 4

struct madprop {
    MADPROP* mad_next;
    void *mad_val;
    U32 mad_vlen;
/*    short mad_count; */
    char mad_key;
    char mad_type;
};

struct token {
    I32 tk_type;
    YYSTYPE tk_lval;
    MADPROP* tk_mad;
};
#endif

/*
 * Values that can be held by mad_key :
 * ^       unfilled head spot
 * ,       literal ,
 * ;       literal ; (blank if implicit ; at end of block)
 * :       literal : from ?: or attr list
 * +       unary +
 * ?       literal ? from ?:
 * (       literal (
 * )       literal )
 * [       literal [
 * ]       literal ]
 * {       literal {
 * }       literal }
 * @       literal @ sigil
 * $       literal $ sigil
 * *       literal * sigil
 * !       use is source filtered
 * &       & or sub
 * #       whitespace/comment following ; or }
 * #       $# sigil
 * 1       1st ; from for(;;)
 * 1       retired protasis
 * 2       2nd ; from for(;;)
 * 2       retired apodosis
 * 3       C-style for list
 * a       sub or var attributes
 * a       non-method arrow operator
 * A       method arrow operator
 * A       use import args
 * b       format block
 * B       retired stub block
 * C       constant conditional op
 * d       declarator
 * D       do block
 * e       unreached "else" (see C)
 * e       expression producing E
 * E       tr/E/R/, /E/
 * f       folded constant op
 * F       peg op for format
 * g       op was forced to be a word
 * i       if/unless modifier
 * I       if/elsif/unless statement
 * k       local declarator
 * K       retired kid op
 * l       last index of array ($#foo)
 * L       label
 * m       modifier on regex
 * n       sub or format name
 * o       current operator/declarator name
 * o       else/continue
 * O       generic optimized op
 * p       peg to hold extra whitespace at statement level
 * P       peg op for package declaration
 * q       opening quote
 * =       quoted material
 * Q       closing quote
 * Q       optimized qw//
 * r       expression producing R
 * R       tr/E/R/ s/E/R/
 * s       sub signature
 * S       use import stub (no import)
 * S       retired sort block
 * t       unreached "then" (see C)
 * U       use import op
 * v       private sv of for loop
 * V       use version
 * w       while/until modifier
 * W       while/for statement
 * x       optimized qw
 * X       random thing
 * _       whitespace/comments preceding anything else
 * ~       =~ operator
 */

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 *
 * ex: set ts=8 sts=4 sw=4 noet:
 */