sv.h

ARM上的如果你对底层感兴趣

/*    sv.h
 *
 *    Copyright (c) 1991-1997, Larry Wall
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

#ifdef sv_flags
#undef sv_flags		/* Convex has this in <signal.h> for sigvec() */
#endif

typedef enum {
	SVt_NULL,	/* 0 */
	SVt_IV,		/* 1 */
	SVt_NV,		/* 2 */
	SVt_RV,		/* 3 */
	SVt_PV,		/* 4 */
	SVt_PVIV,	/* 5 */
	SVt_PVNV,	/* 6 */
	SVt_PVMG,	/* 7 */
	SVt_PVBM,	/* 8 */
	SVt_PVLV,	/* 9 */
	SVt_PVAV,	/* 10 */
	SVt_PVHV,	/* 11 */
	SVt_PVCV,	/* 12 */
	SVt_PVGV,	/* 13 */
	SVt_PVFM,	/* 14 */
	SVt_PVIO	/* 15 */
} svtype;

/* Using C's structural equivalence to help emulate C++ inheritance here... */

struct sv {
    void*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

struct gv {
    XPVGV*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

struct cv {
    XPVCV*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

struct av {
    XPVAV*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

struct hv {
    XPVHV*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

struct io {
    XPVIO*	sv_any;		/* pointer to something */
    U32		sv_refcnt;	/* how many references to us */
    U32		sv_flags;	/* what we are */
};

#define SvANY(sv)	(sv)->sv_any
#define SvFLAGS(sv)	(sv)->sv_flags
#define SvREFCNT(sv)	(sv)->sv_refcnt

#ifdef USE_THREADS

#  ifdef EMULATE_ATOMIC_REFCOUNTS
#    define ATOMIC_INC(count) STMT_START {	\
	MUTEX_LOCK(&PL_svref_mutex);		\
	++count;				\
	MUTEX_UNLOCK(&PL_svref_mutex);		\
     } STMT_END
#    define ATOMIC_DEC_AND_TEST(res,count) STMT_START {	\
	MUTEX_LOCK(&PL_svref_mutex);			\
	res = (--count == 0);				\
	MUTEX_UNLOCK(&PL_svref_mutex);			\
     } STMT_END
#  else
#    define ATOMIC_INC(count) atomic_inc(&count)
#    define ATOMIC_DEC_AND_TEST(res,count) (res = atomic_dec_and_test(&count))
#  endif /* EMULATE_ATOMIC_REFCOUNTS */
#else
#  define ATOMIC_INC(count) (++count)
#  define ATOMIC_DEC_AND_TEST(res, count) (res = (--count == 0))
#endif /* USE_THREADS */

#ifdef __GNUC__
#  define SvREFCNT_inc(sv)		\
    ({					\
	SV *nsv = (SV*)(sv);		\
	if (nsv)			\
	     ATOMIC_INC(SvREFCNT(nsv));	\
	nsv;				\
    })
#else
#  if defined(CRIPPLED_CC) || defined(USE_THREADS)
#    define SvREFCNT_inc(sv) sv_newref((SV*)sv)
#  else
#    define SvREFCNT_inc(sv)	\
	((PL_Sv=(SV*)(sv)), (PL_Sv && ATOMIC_INC(SvREFCNT(PL_Sv))), (SV*)PL_Sv)
#  endif
#endif

#define SvREFCNT_dec(sv)	sv_free((SV*)sv)

#define SVTYPEMASK	0xff
#define SvTYPE(sv)	((sv)->sv_flags & SVTYPEMASK)

#define SvUPGRADE(sv, mt) (SvTYPE(sv) >= mt || sv_upgrade(sv, mt))

#define SVs_PADBUSY	0x00000100	/* reserved for tmp or my already */
#define SVs_PADTMP	0x00000200	/* in use as tmp */
#define SVs_PADMY	0x00000400	/* in use a "my" variable */
#define SVs_TEMP	0x00000800	/* string is stealable? */
#define SVs_OBJECT	0x00001000	/* is "blessed" */
#define SVs_GMG		0x00002000	/* has magical get method */
#define SVs_SMG		0x00004000	/* has magical set method */
#define SVs_RMG		0x00008000	/* has random magical methods */

#define SVf_IOK		0x00010000	/* has valid public integer value */
#define SVf_NOK		0x00020000	/* has valid public numeric value */
#define SVf_POK		0x00040000	/* has valid public pointer value */
#define SVf_ROK		0x00080000	/* has a valid reference pointer */

#define SVf_FAKE	0x00100000	/* glob or lexical is just a copy */
#define SVf_OOK		0x00200000	/* has valid offset value */
#define SVf_BREAK	0x00400000	/* refcnt is artificially low */
#define SVf_READONLY	0x00800000	/* may not be modified */

#define SVf_THINKFIRST	(SVf_READONLY|SVf_ROK)

#define SVp_IOK		0x01000000	/* has valid non-public integer value */
#define SVp_NOK		0x02000000	/* has valid non-public numeric value */
#define SVp_POK		0x04000000	/* has valid non-public pointer value */
#define SVp_SCREAM	0x08000000	/* has been studied? */

#define SVf_OK		(SVf_IOK|SVf_NOK|SVf_POK|SVf_ROK| \
			 SVp_IOK|SVp_NOK|SVp_POK)

#ifdef OVERLOAD
#define SVf_AMAGIC    0x10000000      /* has magical overloaded methods */
#else
#define SVf_AMAGIC    0               /* can be or-ed without effect */
#endif /* OVERLOAD */

#define PRIVSHIFT 8

/* Some private flags. */

#define SVpfm_COMPILED	0x80000000

#define SVpbm_VALID	0x80000000
#define SVpbm_TAIL	0x40000000

#define SVphv_SHAREKEYS 0x20000000	/* keys live on shared string table */
#define SVphv_LAZYDEL	0x40000000	/* entry in xhv_eiter must be deleted */

struct xrv {
    SV *	xrv_rv;		/* pointer to another SV */
};

struct xpv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
};

struct xpviv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
};

struct xpvuv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    UV		xuv_uv;		/* unsigned value or pv offset */
};

struct xpvnv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
};

/* These structure must match the beginning of struct xpvhv in hv.h. */
struct xpvmg {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */
};

struct xpvlv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */

    STRLEN	xlv_targoff;
    STRLEN	xlv_targlen;
    SV*		xlv_targ;
    char	xlv_type;
};

struct xpvgv {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */

    GP*		xgv_gp;
    char*	xgv_name;
    STRLEN	xgv_namelen;
    HV*		xgv_stash;
    U8		xgv_flags;
};

struct xpvbm {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */

    I32		xbm_useful;	/* is this constant pattern being useful? */
    U16		xbm_previous;	/* how many characters in string before rare? */
    U8		xbm_rare;	/* rarest character in string */
};

/* This structure much match XPVCV */

typedef U16 cv_flags_t;

struct xpvfm {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */

    HV *	xcv_stash;
    OP *	xcv_start;
    OP *	xcv_root;
    void      (*xcv_xsub)_((CV* _CPERLproto));
    ANY		xcv_xsubany;
    GV *	xcv_gv;
    GV *	xcv_filegv;
    long	xcv_depth;		/* >= 2 indicates recursive call */
    AV *	xcv_padlist;
    CV *	xcv_outside;
#ifdef USE_THREADS
    perl_mutex *xcv_mutexp;	/* protects xcv_owner */
    struct perl_thread *xcv_owner;	/* current owner thread */
#endif /* USE_THREADS */
    cv_flags_t	xcv_flags;

    I32		xfm_lines;
};

struct xpvio {
    char *	xpv_pv;		/* pointer to malloced string */
    STRLEN	xpv_cur;	/* length of xpv_pv as a C string */
    STRLEN	xpv_len;	/* allocated size */
    IV		xiv_iv;		/* integer value or pv offset */
    double	xnv_nv;		/* numeric value, if any */
    MAGIC*	xmg_magic;	/* linked list of magicalness */
    HV*		xmg_stash;	/* class package */

    PerlIO *	xio_ifp;	/* ifp and ofp are normally the same */
    PerlIO *	xio_ofp;	/* but sockets need separate streams */
    DIR *	xio_dirp;	/* for opendir, readdir, etc */
    long	xio_lines;	/* $. */
    long	xio_page;	/* $% */
    long	xio_page_len;	/* $= */
    long	xio_lines_left;	/* $- */
    char *	xio_top_name;	/* $^ */
    GV *	xio_top_gv;	/* $^ */
    char *	xio_fmt_name;	/* $~ */
    GV *	xio_fmt_gv;	/* $~ */
    char *	xio_bottom_name;/* $^B */
    GV *	xio_bottom_gv;	/* $^B */
    short	xio_subprocess;	/* -| or |- */
    char	xio_type;
    char	xio_flags;
};

#define IOf_ARGV 1	/* this fp iterates over ARGV */
#define IOf_START 2	/* check for null ARGV and substitute '-' */
#define IOf_FLUSH 4	/* this fp wants a flush after write op */
#define IOf_DIDTOP 8	/* just did top of form */
#define IOf_UNTAINT 16  /* consider this fp (and it's data) "safe" */

/* The following macros define implementation-independent predicates on SVs. */

#define SvNIOK(sv)		(SvFLAGS(sv) & (SVf_IOK|SVf_NOK))
#define SvNIOKp(sv)		(SvFLAGS(sv) & (SVp_IOK|SVp_NOK))
#define SvNIOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK| \
						  SVp_IOK|SVp_NOK))

#define SvOK(sv)		(SvFLAGS(sv) & SVf_OK)
#define SvOK_off(sv)		(SvFLAGS(sv) &=	~(SVf_OK|SVf_AMAGIC),	\
							SvOOK_off(sv))

#define SvOKp(sv)		(SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK))
#define SvIOKp(sv)		(SvFLAGS(sv) & SVp_IOK)
#define SvIOKp_on(sv)		(SvOOK_off(sv), SvFLAGS(sv) |= SVp_IOK)
#define SvNOKp(sv)		(SvFLAGS(sv) & SVp_NOK)