The types are:
SVt_NULL
- SVt_BIND (unused)
SVt_IV
SVt_NV
SVt_RV
typedef enum {
SVt_NULL, /* 0 */
- SVt_BIND, /* 1 */
+ SVt_DUMMY, /* 1 */
SVt_IV, /* 2 */
SVt_NV, /* 3 */
/* RV was here, before it was merged with IV. */
Returns the value of the object's reference count.
=for apidoc Am|SV*|SvREFCNT_inc|SV* sv
-Increments the reference count of the given SV.
+Increments the reference count of the given SV, returning the SV.
All of the following SvREFCNT_inc* macros are optimized versions of
SvREFCNT_inc, and can be replaced with SvREFCNT_inc.
and faster.
=for apidoc Am|void|SvREFCNT_dec|SV* sv
-Decrements the reference count of the given SV.
+Decrements the reference count of the given SV. I<sv> may be NULL.
+
+=for apidoc Am|void|SvREFCNT_dec_NN|SV* sv
+Same as SvREFCNT_dec, but can only be used if you know I<sv>
+is not NULL. Since we don't have to check the NULLness, it's faster
+and smaller.
=for apidoc Am|svtype|SvTYPE|SV* sv
Returns the type of the SV. See C<svtype>.
#define SvREFCNT_inc_simple_void_NN(sv) (void)(++SvREFCNT(MUTABLE_SV(sv)))
#define SvREFCNT_dec(sv) S_SvREFCNT_dec(aTHX_ MUTABLE_SV(sv))
+#define SvREFCNT_dec_NN(sv) S_SvREFCNT_dec_NN(aTHX_ MUTABLE_SV(sv))
#define SVTYPEMASK 0xff
#define SvTYPE(sv) ((svtype)((sv)->sv_flags & SVTYPEMASK))
them all by using a consistent macro. */
#define SvIS_FREED(sv) ((sv)->sv_flags == SVTYPEMASK)
-#define SvUPGRADE(sv, mt) (SvTYPE(sv) >= (mt) || (sv_upgrade(sv, mt), 1))
+/* this is defined in this peculiar way to avoid compiler warnings.
+ * See the <20121213131428.GD1842@iabyn.com> thread in p5p */
+#define SvUPGRADE(sv, mt) \
+ ((void)(SvTYPE(sv) >= (mt) || (sv_upgrade(sv, mt),1)))
#define SVf_IOK 0x00000100 /* has valid public integer value */
#define SVf_NOK 0x00000200 /* has valid public numeric value */
Tells an SV that it is an integer and disables all other OK bits.
=for apidoc Am|void|SvIOK_only_UV|SV* sv
-Tells and SV that it is an unsigned integer and disables all other OK bits.
+Tells an SV that it is an unsigned integer and disables all other OK bits.
=for apidoc Am|bool|SvIOK_UV|SV* sv
-Returns a boolean indicating whether the SV contains an unsigned integer.
+Returns a boolean indicating whether the SV contains an integer that must be
+interpreted as unsigned. A non-negative integer whose value is within the
+range of both an IV and a UV may be be flagged as either SvUOK or SVIOK.
=for apidoc Am|bool|SvUOK|SV* sv
-Returns a boolean indicating whether the SV contains an unsigned integer.
+Returns a boolean indicating whether the SV contains an integer that must be
+interpreted as unsigned. A non-negative integer whose value is within the
+range of both an IV and a UV may be be flagged as either SvUOK or SVIOK.
=for apidoc Am|bool|SvIOK_notUV|SV* sv
Returns a boolean indicating whether the SV contains a signed integer.
=for apidoc Am|char*|SvPVX|SV* sv
Returns a pointer to the physical string in the SV. The SV must contain a
-string.
+string. Prior to 5.9.3 it is not safe to execute this macro unless the SV's
+type >= SVt_PV.
This is also used to store the name of an autoloaded subroutine in an XS
AUTOLOAD routine. See L<perlguts/Autoloading with XSUBs>.
Set the value of the NV pointer in sv to val. See C<SvIV_set>.
=for apidoc Am|void|SvPV_set|SV* sv|char* val
-Set the value of the PV pointer in sv to val. See C<SvIV_set>.
+Set the value of the PV pointer in sv to val. See also C<SvIV_set>.
+
+Beware that the existing pointer may be involved in copy-on-write or other
+mischief, so do C<SvOOK_off(sv)> and use C<sv_force_normal> or
+C<SvPV_force> (or check the SvIsCOW flag) first to make sure this
+modification is safe.
=for apidoc Am|void|SvUV_set|SV* sv|UV val
Set the value of the UV pointer in sv to val. See C<SvIV_set>.
#define assert_not_ROK(sv) assert_(!SvROK(sv) || !SvRV(sv))
#define assert_not_glob(sv) assert_(!isGV_with_GP(sv))
-#define SvOK(sv) ((SvTYPE(sv) == SVt_BIND) \
- ? (SvFLAGS(SvRV(sv)) & SVf_OK \
- || isREGEXP(SvRV(sv))) \
- : (SvFLAGS(sv) & SVf_OK \
- || isREGEXP(sv)))
+#define SvOK(sv) (SvFLAGS(sv) & SVf_OK || isREGEXP(sv))
#define SvOK_off(sv) (assert_not_ROK(sv) assert_not_glob(sv) \
SvFLAGS(sv) &= ~(SVf_OK| \
SVf_IVisUV|SVf_UTF8), \
=for apidoc Am|U32|SvUTF8|SV* sv
Returns a U32 value indicating the UTF-8 status of an SV. If things are set-up
properly, this indicates whether or not the SV contains UTF-8 encoded data.
-Call this after SvPV() in case any call to string overloading updates the
-internal flag.
+You should use this I<after> a call to SvPV() or one of its variants, in
+case any call to string overloading updates the internal flag.
=for apidoc Am|void|SvUTF8_on|SV *sv
Turn on the UTF-8 status of an SV (the data is not changed, just the flag).
/*
=for apidoc Am|char*|SvPV_force|SV* sv|STRLEN len
Like C<SvPV> but will force the SV into containing a string (C<SvPOK>), and
-only a string (C<SvPOK_only>), by hook or by crook. You want force if you are
+only a string (C<SvPOK_only>), by hook or by crook. You need force if you are
going to update the C<SvPVX> directly. Processes get magic.
+Note that coercing an arbitrary scalar into a plain PV will potentially
+strip useful data from it. For example if the SV was C<SvROK>, then the
+referent will have its reference count decremented, and the SV itself may
+be converted to an C<SvPOK> scalar with a string buffer containing a value
+such as C<"ARRAY(0x1234)">.
+
=for apidoc Am|char*|SvPV_force_nomg|SV* sv|STRLEN len
-Like C<SvPV> but will force the SV into containing a string (C<SvPOK>), and
-only a string (C<SvPOK_only>), by hook or by crook. You want force if you are
-going to update the C<SvPVX> directly. Doesn't process get magic.
+Like C<SvPV_force>, but doesn't process get magic.
=for apidoc Am|char*|SvPV|SV* sv|STRLEN len
Returns a pointer to the string in the SV, or a stringified form of
stringified version becoming C<SvPOK>. Handles 'get' magic. See also
C<SvPVx> for a version which guarantees to evaluate sv only once.
+Note that there is no guarantee that the return value of C<SvPV()> is
+equal to C<SvPVX(sv)>, or that C<SvPVX(sv)> contains valid data, or that
+successive calls to C<SvPV(sv)) will return the same pointer value each
+time. This is due to the way that things like overloading and
+Copy-On-Write are handled. In these cases, the return value may point to
+a temporary buffer or similar. If you absolutely need the SvPVX field to
+be valid (for example, if you intend to write to it), then see
+L</SvPV_force>.
+
=for apidoc Am|char*|SvPVx|SV* sv|STRLEN len
A version of C<SvPV> which guarantees to evaluate C<sv> only once.
Only use this if C<sv> is an expression with side effects, otherwise use the
Like C<SvPV> but doesn't process magic.
=for apidoc Am|char*|SvPV_nolen|SV* sv
-Returns a pointer to the string in the SV, or a stringified form of
-the SV if the SV does not contain a string. The SV may cache the
-stringified form becoming C<SvPOK>. Handles 'get' magic.
+Like C<SvPV> but doesn't set a length variable.
=for apidoc Am|char*|SvPV_nomg_nolen|SV* sv
Like C<SvPV_nolen> but doesn't process magic.
=for apidoc Am|UV|SvUVx|SV* sv
Coerces the given SV to an unsigned integer and
-returns it. Guarantees to C<sv> only once. Only
+returns it. Guarantees to evaluate C<sv> only once. Only
use this if C<sv> is an expression with side effects,
otherwise use the more efficient C<SvUV>.
# define SvPVbytex_nolen(sv) ({SV *_sv = (sv); SvPVbyte_nolen(_sv); })
# define SvTRUEx(sv) ({SV *_sv = (sv); SvTRUE(_sv); })
# define SvTRUEx_nomg(sv) ({SV *_sv = (sv); SvTRUE_nomg(_sv); })
-# define SvPVXtrue(sv) \
- ({XPV *nxpv; \
- (nxpv = (XPV*)SvANY(sv)) \
- && (nxpv->xpv_cur > 1 \
- || (nxpv->xpv_cur && *(sv)->sv_u.svu_pv != '0'));})
#else /* __GNUC__ */
# define SvPVbytex_nolen(sv) ((PL_Sv = (sv)), SvPVbyte_nolen(PL_Sv))
# define SvTRUEx(sv) ((PL_Sv = (sv)), SvTRUE(PL_Sv))
# define SvTRUEx_nomg(sv) ((PL_Sv = (sv)), SvTRUE_nomg(PL_Sv))
-# define SvPVXtrue(sv) \
- ((PL_Xpv = (XPV*)SvANY(PL_Sv = (sv))) \
- && (PL_Xpv->xpv_cur > 1 \
- || (PL_Xpv->xpv_cur && *PL_Sv->sv_u.svu_pv != '0')))
#endif /* __GNU__ */
+#define SvPVXtrue(sv) ( \
+ ((XPV*)SvANY((sv))) \
+ && ( \
+ ((XPV*)SvANY((sv)))->xpv_cur > 1 \
+ || ( \
+ ((XPV*)SvANY((sv)))->xpv_cur \
+ && *(sv)->sv_u.svu_pv != '0' \
+ ) \
+ ) \
+)
+
#define SvIsCOW(sv) (SvFLAGS(sv) & SVf_IsCOW)
#define SvIsCOW_on(sv) (SvFLAGS(sv) |= SVf_IsCOW)
#define SvIsCOW_off(sv) (SvFLAGS(sv) &= ~SVf_IsCOW)
((SvIsCOW(sv) ? sv_force_normal_flags(sv, 0) : (void) 0), 0)
# define SvIsCOW_normal(sv) (SvIsCOW(sv) && SvLEN(sv))
# define SvRELEASE_IVX_(sv) SvRELEASE_IVX(sv),
+# define SvCANCOW(sv) \
+ (SvIsCOW(sv) || (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS)
+/* This is a pessimistic view. Scalar must be purely a read-write PV to copy-
+ on-write. */
+# define CAN_COW_MASK (SVs_OBJECT|SVs_GMG|SVs_SMG|SVs_RMG|SVf_IOK|SVf_NOK| \
+ SVf_POK|SVf_ROK|SVp_IOK|SVp_NOK|SVp_POK|SVf_FAKE| \
+ SVf_OOK|SVf_BREAK|SVf_READONLY)
#else
# define SvRELEASE_IVX(sv) 0
/* This little game brought to you by the need to shut this warning up:
mg.c:1024: warning: left-hand operand of comma expression has no effect
*/
# define SvRELEASE_IVX_(sv) /**/
+# ifdef PERL_NEW_COPY_ON_WRITE
+# define SvCANCOW(sv) \
+ (SvIsCOW(sv) \
+ ? SvLEN(sv) ? CowREFCNT(sv) != SV_COW_REFCNT_MAX : 1 \
+ : (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS \
+ && SvCUR(sv)+1 < SvLEN(sv))
+ /* Note: To allow 256 COW "copies", a refcnt of 0 means 1. */
+# define CowREFCNT(sv) (*(U8 *)(SvPVX(sv)+SvLEN(sv)-1))
+# define SV_COW_REFCNT_MAX ((1 << sizeof(U8)*8) - 1)
+# ifndef SV_COW_THRESHOLD
+# define SV_COW_THRESHOLD 0 /* min string length for cow */
+# endif
+# ifndef SV_COWBUF_THRESHOLD
+# define SV_COWBUF_THRESHOLD 1250 /* min string length for cow */
+# endif /* over existing buffer */
+# define CAN_COW_MASK (SVf_POK|SVf_ROK|SVp_POK|SVf_FAKE| \
+ SVf_OOK|SVf_BREAK|SVf_READONLY)
+# endif
#endif /* PERL_OLD_COPY_ON_WRITE */
-#define CAN_COW_MASK (SVs_OBJECT|SVs_GMG|SVs_SMG|SVs_RMG|SVf_IOK|SVf_NOK| \
- SVf_POK|SVf_ROK|SVp_IOK|SVp_NOK|SVp_POK|SVf_FAKE| \
- SVf_OOK|SVf_BREAK|SVf_READONLY)
#define CAN_COW_FLAGS (SVp_POK|SVf_POK)
#define SV_CHECK_THINKFIRST(sv) if (SvTHINKFIRST(sv)) \
Expands the character buffer in the SV so that it has room for the
indicated number of bytes (remember to reserve space for an extra trailing
NUL character). Calls C<sv_grow> to perform the expansion if necessary.
-Returns a pointer to the character buffer.
+Returns a pointer to the character buffer. SV must be of type >= SVt_PV. One
+alternative is to call C<sv_grow> if you are not sure of the type of SV.
=cut
*/
#define SvPEEK(sv) ""
#endif
-#define SvIMMORTAL(sv) ((sv)==&PL_sv_undef || (sv)==&PL_sv_yes || (sv)==&PL_sv_no || (sv)==&PL_sv_placeholder)
+#define SvIMMORTAL(sv) (SvREADONLY(sv) && ((sv)==&PL_sv_undef || (sv)==&PL_sv_yes || (sv)==&PL_sv_no || (sv)==&PL_sv_placeholder))
+
+#ifdef DEBUGGING
+ /* exercise the immortal resurrection code in sv_free2() */
+# define SvREFCNT_IMMORTAL 1000
+#else
+# define SvREFCNT_IMMORTAL ((~(U32)0)/2)
+#endif
/*
=for apidoc Am|SV *|boolSV|bool b
== (SVt_PVLV|SVf_FAKE))
-#define SvGROW(sv,len) (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
+#ifdef PERL_NEW_COPY_ON_WRITE
+# define SvGROW(sv,len) \
+ (SvIsCOW(sv) || SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
+#else
+# define SvGROW(sv,len) (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
+#endif
#define SvGROW_mutable(sv,len) \
(SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX_mutable(sv))
#define Sv_Grow sv_grow
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