regcomp.c: Properly dereference a ptr

[perl5.git] / mg.h

/*    mg.h
 *
 *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999,
 *    2000, 2002, 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.
 *
 */

struct mgvtbl {
    int		(*svt_get)	(pTHX_ SV *sv, MAGIC* mg);
    int		(*svt_set)	(pTHX_ SV *sv, MAGIC* mg);
    U32		(*svt_len)	(pTHX_ SV *sv, MAGIC* mg);
    int		(*svt_clear)(pTHX_ SV *sv, MAGIC* mg);
    int		(*svt_free)	(pTHX_ SV *sv, MAGIC* mg);
    int		(*svt_copy)	(pTHX_ SV *sv, MAGIC* mg,
    					SV *nsv, const char *name, I32 namlen);
    int		(*svt_dup)	(pTHX_ MAGIC *mg, CLONE_PARAMS *param);
    int		(*svt_local)(pTHX_ SV *nsv, MAGIC *mg);
};

struct magic {
    MAGIC*	mg_moremagic;
    MGVTBL*	mg_virtual;	/* pointer to magic functions */
    U16		mg_private;
    char	mg_type;
    U8		mg_flags;
    SSize_t	mg_len;
    SV*		mg_obj;
    char*	mg_ptr;
};

#define MGf_TAINTEDDIR 1        /* PERL_MAGIC_envelem only */
#define MGf_MINMATCH   1        /* PERL_MAGIC_regex_global only */
#define MGf_REQUIRE_GV 1        /* PERL_MAGIC_checkcall only */
#define MGf_REFCOUNTED 2
#define MGf_GSKIP      4	/* skip further GETs until after next SET */
#define MGf_COPY       8	/* has an svt_copy  MGVTBL entry */
#define MGf_DUP     0x10 	/* has an svt_dup   MGVTBL entry */
#define MGf_LOCAL   0x20	/* has an svt_local MGVTBL entry */
#define MGf_BYTES   0x40        /* PERL_MAGIC_regex_global only */

#define MgTAINTEDDIR(mg)	(mg->mg_flags & MGf_TAINTEDDIR)
#define MgTAINTEDDIR_on(mg)	(mg->mg_flags |= MGf_TAINTEDDIR)
#define MgTAINTEDDIR_off(mg)	(mg->mg_flags &= ~MGf_TAINTEDDIR)

#define MgPV(mg,lp)		((((int)(lp = (mg)->mg_len)) == HEf_SVKEY) ?   \
				 SvPV(MUTABLE_SV((mg)->mg_ptr),lp) :	\
				 (mg)->mg_ptr)
#define MgPV_const(mg,lp)	((((int)(lp = (mg)->mg_len)) == HEf_SVKEY) ? \
				 SvPV_const(MUTABLE_SV((mg)->mg_ptr),lp) :   \
				 (const char*)(mg)->mg_ptr)
#define MgPV_nolen_const(mg)	(((((int)(mg)->mg_len)) == HEf_SVKEY) ?	\
				 SvPV_nolen_const(MUTABLE_SV((mg)->mg_ptr)) : \
				 (const char*)(mg)->mg_ptr)

#define SvTIED_mg(sv,how) (SvRMAGICAL(sv) ? mg_find((sv),(how)) : NULL)
#define SvTIED_obj(sv,mg) \
    ((mg)->mg_obj ? (mg)->mg_obj : sv_2mortal(newRV(sv)))

#if defined(PERL_CORE) || defined(PERL_EXT)
# define MgBYTEPOS(mg,sv,pv,len) S_MgBYTEPOS(aTHX_ mg,sv,pv,len)
/* assumes get-magic and stringification have already occurred */
# define MgBYTEPOS_set(mg,sv,pv,off) (			 \
    assert_((mg)->mg_type == PERL_MAGIC_regex_global)	  \
    SvPOK(sv) && !SvGMAGICAL(sv)			   \
	? (mg)->mg_len = (off), (mg)->mg_flags |= MGf_BYTES \
	: ((mg)->mg_len = DO_UTF8(sv)			     \
	    ? (SSize_t)utf8_length((U8 *)(pv), (U8 *)(pv)+(off)) \
	    : (SSize_t)(off),					  \
	   (mg)->mg_flags &= ~MGf_BYTES))
#endif

#define whichsig(pv) whichsig_pv(pv)

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