op.h

/*    op.h
 *
 *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 2003, 2004, 2005 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_static	Whether or not the op is statically defined.
 *			This flag is used by the B::C compiler backend
 *			and indicates that the op should not be freed.
 *	op_spare	Five 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).
 */

#ifdef DEBUGGING_OPS
#define OPCODE opcode
#else
#define OPCODE U16
#endif

#ifdef BASEOP_DEFINITION
#define BASEOP BASEOP_DEFINITION
#else
#define BASEOP				\
    OP*		op_next;		\
    OP*		op_sibling;		\
    OP*		(CPERLscope(*op_ppaddr))(pTHX);		\
    PADOFFSET	op_targ;		\
    unsigned	op_type:9;		\
    unsigned	op_opt:1;		\
    unsigned	op_static:1;		\
    unsigned	op_spare:5;		\
    U8		op_flags;		\
    U8		op_private;
#endif

#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)

/*
=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.

=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 $@ */
				/*  On OP_ENTERITER, loop var is per-thread */
				/*  On pushre, re is /\s+/ imp. by split " " */
				/*  On regcomp, "use re 'eval'" was in scope */
				/*  On OP_READLINE, was <$filehandle> */
				/*  On RV2[SG]V, don't create GV--in defined()*/
				/*  On OP_DBSTATE, indicates breakpoint
				 *    (runtime property) */
				/*  On OP_AELEMFAST, indiciates pad var */

/* 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, OP_DBSTATE, and OP_SETSTATE (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. */

/* 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. */
  /* OP_ENTERSUB only */
#define OPpENTERSUB_DB		16	/* Debug subroutine. */
#define OPpENTERSUB_HASTARG	32	/* Called from OP tree. */
#define OPpENTERSUB_NOMOD	64	/* Immune to mod() for :attrlist. */
  /* 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[AH]V, OP_PAD[AH]V, OP_[AH]ELEM */
#define OPpMAYBE_LVSUB		8	/* We might be an lvalue to return */
  /* for OP_RV2?V, lower bits carry hints (currently only HINT_STRICT_REFS) */

/* 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 ...) */

/* Private for OP_CONST */
#define	OPpCONST_SHORTCIRCUIT	4	/* eg the constant 5 in (5 || foo) */
#define	OPpCONST_STRICT		8	/* bearword 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 */

/* 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 */
/* Private for OP_THREADSV */
#define OPpDONE_SVREF		64	/* Been through newSVREF once */

/* 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 of OP_FTXXX */
#define OPpFT_ACCESS		2	/* use filetest 'access' */
#define OPpFT_STACKED		4	/* stacked filetest, as in "-f -x $f" */
#define OP_IS_FILETEST_ACCESS(op) 		\
	(((op)->op_type) == OP_FTRREAD  ||	\
	 ((op)->op_type) == OP_FTRWRITE ||	\
	 ((op)->op_type) == OP_FTREXEC  ||	\
	 ((op)->op_type) == OP_FTEREAD  ||	\
	 ((op)->op_type) == OP_FTEWRITE ||	\
	 ((op)->op_type) == OP_FTEEXEC)

/* Private for OP_(MAP|GREP)(WHILE|START) */
#define OPpGREP_LEX		2	/* iterate over lexical $_ */
    
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;
    OP *	op_pmreplroot; /* (type is really union {OP*,GV*,PADOFFSET}) */
    OP *	op_pmreplstart;
    PMOP *	op_pmnext;		/* list of all scanpats */
#ifdef USE_ITHREADS
    IV          op_pmoffset;
#else
    REGEXP *    op_pmregexp;            /* compiled expression */
#endif
    U32		op_pmflags;
    U32		op_pmpermflags;
    U8		op_pmdynflags;
#ifdef USE_ITHREADS
    char *	op_pmstashpv;
#else
    HV *	op_pmstash;
#endif
};

#ifdef USE_ITHREADS
#define PM_GETRE(o)     (INT2PTR(REGEXP*,SvIVX(PL_regex_pad[(o)->op_pmoffset])))
#define PM_SETRE(o,r)   STMT_START { SV* sv = PL_regex_pad[(o)->op_pmoffset]; sv_setiv(sv, PTR2IV(r)); } STMT_END
#define PM_GETRE_SAFE(o) (PL_regex_pad ? PM_GETRE(o) : (REGEXP*)0)
#define PM_SETRE_SAFE(o,r) if (PL_regex_pad) PM_SETRE(o,r)
#else
#define PM_GETRE(o)     ((o)->op_pmregexp)
#define PM_SETRE(o,r)   ((o)->op_pmregexp = (r))
#define PM_GETRE_SAFE PM_GETRE
#define PM_SETRE_SAFE PM_SETRE
#endif

#define PMdf_USED	0x01		/* pm has been used once already */
#define PMdf_TAINTED	0x02		/* pm compiled from tainted pattern */
#define PMdf_UTF8	0x04		/* pm compiled from utf8 data */
#define PMdf_DYN_UTF8	0x08

#define PMdf_CMP_UTF8	(PMdf_UTF8|PMdf_DYN_UTF8)

#define PMf_RETAINT	0x0001		/* taint $1 etc. if target tainted */
#define PMf_ONCE	0x0002		/* use pattern only once per reset */
#define PMf_UNUSED	0x0004		/* free for use */
#define PMf_MAYBE_CONST	0x0008		/* replacement contains variables */
#define PMf_SKIPWHITE	0x0010		/* skip leading whitespace for split */
#define PMf_WHITE	0x0020		/* pattern is \s+ */
#define PMf_CONST	0x0040		/* subst replacement is constant */
#define PMf_KEEP	0x0080		/* keep 1st runtime pattern forever */
#define PMf_GLOBAL	0x0100		/* pattern had a g modifier */
#define PMf_CONTINUE	0x0200		/* don't reset pos() if //g fails */
#define PMf_EVAL	0x0400		/* evaluating replacement as expr */
#define PMf_LOCALE	0x0800		/* use locale for character types */
#define PMf_MULTILINE	0x1000		/* assume multiple lines */
#define PMf_SINGLELINE	0x2000		/* assume single line */
#define PMf_FOLD	0x4000		/* case insensitivity */
#define PMf_EXTENDED	0x8000		/* chuck embedded whitespace */

/* mask of bits stored in regexp->reganch */
#define PMf_COMPILETIME	(PMf_MULTILINE|PMf_SINGLELINE|PMf_LOCALE|PMf_FOLD|PMf_EXTENDED)

#ifdef USE_ITHREADS

#  define PmopSTASHPV(o)	((o)->op_pmstashpv)
#  define PmopSTASHPV_set(o,pv)	(PmopSTASHPV(o) = savesharedpv(pv))
#  define PmopSTASH(o)		(PmopSTASHPV(o) \
				 ? gv_stashpv(PmopSTASHPV(o),GV_ADD) : Nullhv)
#  define PmopSTASH_set(o,hv)	PmopSTASHPV_set(o, ((hv) ? HvNAME(hv) : Nullch))
#  define PmopSTASH_free(o)	PerlMemShared_free(PmopSTASHPV(o))

#else
#  define PmopSTASH(o)		((o)->op_pmstash)
#  define PmopSTASH_set(o,hv)	((o)->op_pmstash = (hv))
#  define PmopSTASHPV(o)	(PmopSTASH(o) ? HvNAME(PmopSTASH(o)) : Nullch)
   /* op_pmstash is not refcounted */
#  define PmopSTASHPV_set(o,pv)	PmopSTASH_set((o), gv_stashpv(pv,GV_ADD))
#  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 && 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)

#define Nullop Null(OP*)

/* 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_RETINTEGER 16
#define OA_OTHERINT 32
#define OA_DANGEROUS 64
#define OA_DEFGV 128
#define OA_TARGLEX 256

/* The next 4 bits encode op class information */
#define OCSHIFT 9

#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 13

/* 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

#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))
#define OpREFCNT_inc(o)			((o) ? (++(o)->op_targ, (o)) : Nullop)
#define OpREFCNT_dec(o)			(--(o)->op_targ)

/* flags used by Perl_load_module() */
#define PERL_LOADMOD_DENY		0x1
#define PERL_LOADMOD_NOIMPORT		0x2
#define PERL_LOADMOD_IMPORT_OPS		0x4

#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_ m,c*sizeof(type)))
#define NewOpSz(m,var,size)	\
	(var = (OP *) Perl_Slab_Alloc(aTHX_ m,size))
#define FreeOp(p) Perl_Slab_Free(aTHX_ p)
#else
#define NewOp(m, var, c, type) Newz(m, var, c, type)
#define NewOpSz(m, var, size)	\
	(var = (OP*)safemalloc(size), memzero(var, size))
#define FreeOp(p) Safefree(p)
#endif