X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=sv.h;h=5500d2b46b7a37247e1c05a24b4642eea96d0f66;hb=5a49ee455a6d068697635b12375f31af98486866;hp=1374c87a5c29e40610fe3939c9947d5a12345aa9;hpb=f83ee824cada302b23f7337a82f3b9d44bde7629;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/sv.h b/sv.h
index 1374c87..5500d2b 100644
--- a/sv.h
+++ b/sv.h
@@ -1,6 +1,6 @@
 /*    sv.h
  *
- *    Copyright (c) 1991-1999, Larry Wall
+ *    Copyright (c) 1991-2000, 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.
@@ -11,6 +11,35 @@
 #undef sv_flags		/* Convex has this in <signal.h> for sigvec() */
 #endif
 
+/*
+=for apidoc AmU||svtype
+An enum of flags for Perl types.  These are found in the file B<sv.h> 
+in the C<svtype> enum.  Test these flags with the C<SvTYPE> macro.
+
+=for apidoc AmU||SVt_PV
+Pointer type flag for scalars.  See C<svtype>.
+
+=for apidoc AmU||SVt_IV
+Integer type flag for scalars.  See C<svtype>.
+
+=for apidoc AmU||SVt_NV
+Double type flag for scalars.  See C<svtype>.
+
+=for apidoc AmU||SVt_PVMG
+Type flag for blessed scalars.  See C<svtype>.
+
+=for apidoc AmU||SVt_PVAV
+Type flag for arrays.  See C<svtype>.
+
+=for apidoc AmU||SVt_PVHV
+Type flag for hashes.  See C<svtype>.
+
+=for apidoc AmU||SVt_PVCV
+Type flag for code refs.  See C<svtype>.
+
+=cut
+*/
+
 typedef enum {
 	SVt_NULL,	/* 0 */
 	SVt_IV,		/* 1 */
@@ -68,27 +97,52 @@ struct io {
     U32		sv_flags;	/* what we are */
 };
 
+/*
+=for apidoc Am|U32|SvREFCNT|SV* sv
+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.
+
+=for apidoc Am|void|SvREFCNT_dec|SV* sv
+Decrements the reference count of the given SV.
+
+=for apidoc Am|svtype|SvTYPE|SV* sv
+Returns the type of the SV.  See C<svtype>.
+
+=for apidoc Am|void|SvUPGRADE|SV* sv|svtype type
+Used to upgrade an SV to a more complex form.  Uses C<sv_upgrade> to
+perform the upgrade if necessary.  See C<svtype>.
+
+=cut
+*/
+
 #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 */
+#  if defined(VMS)
+#    define ATOMIC_INC(count) __ATOMIC_INCREMENT_LONG(&count)
+#    define ATOMIC_DEC_AND_TEST(res,count) res=(1==__ATOMIC_DECREMENT_LONG(&count))
+ #  else
+#    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 */
+#  endif /* VMS */
 #else
 #  define ATOMIC_INC(count) (++count)
 #  define ATOMIC_DEC_AND_TEST(res, count) (res = (--count == 0))
@@ -104,7 +158,12 @@ struct io {
     })
 #else
 #  if defined(CRIPPLED_CC) || defined(USE_THREADS)
-#    define SvREFCNT_inc(sv) sv_newref((SV*)sv)
+#    if defined(VMS) && defined(__ALPHA)
+#      define SvREFCNT_inc(sv) \
+          (PL_Sv=(SV*)(sv), (PL_Sv && __ATOMIC_INCREMENT_LONG(&(SvREFCNT(PL_Sv)))), (SV *)PL_Sv)
+#    else
+#      define SvREFCNT_inc(sv) sv_newref((SV*)sv)
+#    endif
 #  else
 #    define SvREFCNT_inc(sv)	\
 	((PL_Sv=(SV*)(sv)), (PL_Sv && ATOMIC_INC(SvREFCNT(PL_Sv))), (SV*)PL_Sv)
@@ -156,6 +215,7 @@ struct io {
 
 /* Some private flags. */
 
+/* SVpad_OUR may be set on SVt_PV{NV,MG,GV} types */
 #define SVpad_OUR	0x80000000	/* pad name is "our" instead of "my" */
 
 #define SVf_IVisUV	0x80000000	/* use XPVUV instead of XPVIV */
@@ -303,7 +363,19 @@ struct xpvio {
 
     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 */
+    /* Cray addresses everything by word boundaries (64 bits) and
+     * code and data pointers cannot be mixed (which is exactly what
+     * Perl_filter_add() tries to do with the dirp), hence the following
+     * union trick (as suggested by Gurusamy Sarathy).
+     * For further information see Geir Johansen's problem report titled
+       [ID 20000612.002] Perl problem on Cray system
+     * The any pointer (known as IoANY()) will also be a good place
+     * to hang any IO disciplines to.
+     */
+    union {
+	DIR *	xiou_dirp;	/* for opendir, readdir, etc */
+	void *	xiou_any;	/* for alignment */
+    } xio_dirpu;
     long	xio_lines;	/* $. */
     long	xio_page;	/* $% */
     long	xio_page_len;	/* $= */
@@ -318,6 +390,8 @@ struct xpvio {
     char	xio_type;
     char	xio_flags;
 };
+#define xio_dirp	xio_dirpu.xiou_dirp
+#define xio_any		xio_dirpu.xiou_any
 
 #define IOf_ARGV	1	/* this fp iterates over ARGV */
 #define IOf_START	2	/* check for null ARGV and substitute '-' */
@@ -329,6 +403,124 @@ struct xpvio {
 
 /* The following macros define implementation-independent predicates on SVs. */
 
+/*
+=for apidoc Am|bool|SvNIOK|SV* sv
+Returns a boolean indicating whether the SV contains a number, integer or
+double.
+
+=for apidoc Am|bool|SvNIOKp|SV* sv
+Returns a boolean indicating whether the SV contains a number, integer or
+double.  Checks the B<private> setting.  Use C<SvNIOK>.
+
+=for apidoc Am|void|SvNIOK_off|SV* sv
+Unsets the NV/IV status of an SV.
+
+=for apidoc Am|bool|SvOK|SV* sv
+Returns a boolean indicating whether the value is an SV.
+
+=for apidoc Am|bool|SvIOKp|SV* sv
+Returns a boolean indicating whether the SV contains an integer.  Checks
+the B<private> setting.  Use C<SvIOK>.
+
+=for apidoc Am|bool|SvNOKp|SV* sv
+Returns a boolean indicating whether the SV contains a double.  Checks the
+B<private> setting.  Use C<SvNOK>.
+
+=for apidoc Am|bool|SvPOKp|SV* sv
+Returns a boolean indicating whether the SV contains a character string.
+Checks the B<private> setting.  Use C<SvPOK>.
+
+=for apidoc Am|bool|SvIOK|SV* sv
+Returns a boolean indicating whether the SV contains an integer.
+
+=for apidoc Am|void|SvIOK_on|SV* sv
+Tells an SV that it is an integer.
+
+=for apidoc Am|void|SvIOK_off|SV* sv
+Unsets the IV status of an SV.
+
+=for apidoc Am|void|SvIOK_only|SV* sv
+Tells an SV that it is an integer and disables all other OK bits.
+
+=for apidoc Am|bool|SvNOK|SV* sv
+Returns a boolean indicating whether the SV contains a double.
+
+=for apidoc Am|void|SvNOK_on|SV* sv
+Tells an SV that it is a double.
+
+=for apidoc Am|void|SvNOK_off|SV* sv
+Unsets the NV status of an SV.
+
+=for apidoc Am|void|SvNOK_only|SV* sv
+Tells an SV that it is a double and disables all other OK bits.
+
+=for apidoc Am|bool|SvPOK|SV* sv
+Returns a boolean indicating whether the SV contains a character
+string.
+
+=for apidoc Am|void|SvPOK_on|SV* sv
+Tells an SV that it is a string.
+
+=for apidoc Am|void|SvPOK_off|SV* sv
+Unsets the PV status of an SV.
+
+=for apidoc Am|void|SvPOK_only|SV* sv
+Tells an SV that it is a string and disables all other OK bits.
+
+=for apidoc Am|bool|SvOOK|SV* sv
+Returns a boolean indicating whether the SvIVX is a valid offset value for
+the SvPVX.  This hack is used internally to speed up removal of characters
+from the beginning of a SvPV.  When SvOOK is true, then the start of the
+allocated string buffer is really (SvPVX - SvIVX).
+
+=for apidoc Am|bool|SvROK|SV* sv
+Tests if the SV is an RV.
+
+=for apidoc Am|void|SvROK_on|SV* sv
+Tells an SV that it is an RV.
+
+=for apidoc Am|void|SvROK_off|SV* sv
+Unsets the RV status of an SV.
+
+=for apidoc Am|SV*|SvRV|SV* sv
+Dereferences an RV to return the SV.
+
+=for apidoc Am|IV|SvIVX|SV* sv
+Returns the integer which is stored in the SV, assuming SvIOK is
+true.
+
+=for apidoc Am|UV|SvUVX|SV* sv
+Returns the unsigned integer which is stored in the SV, assuming SvIOK is
+true.
+
+=for apidoc Am|NV|SvNVX|SV* sv
+Returns the double which is stored in the SV, assuming SvNOK is
+true.
+
+=for apidoc Am|char*|SvPVX|SV* sv
+Returns a pointer to the string in the SV.  The SV must contain a
+string.
+
+=for apidoc Am|STRLEN|SvCUR|SV* sv
+Returns the length of the string which is in the SV.  See C<SvLEN>.
+
+=for apidoc Am|STRLEN|SvLEN|SV* sv
+Returns the size of the string buffer in the SV, not including any part
+attributable to C<SvOOK>.  See C<SvCUR>.
+
+=for apidoc Am|char*|SvEND|SV* sv
+Returns a pointer to the last character in the string which is in the SV.
+See C<SvCUR>.  Access the character as *(SvEND(sv)).
+
+=for apidoc Am|HV*|SvSTASH|SV* sv
+Returns the stash of the SV.
+
+=for apidoc Am|void|SvCUR_set|SV* sv|STRLEN len
+Set the length of the string which is in the SV.  See C<SvCUR>.
+
+=cut
+*/
+
 #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| \
@@ -336,26 +528,27 @@ struct xpvio {
 
 #define SvOK(sv)		(SvFLAGS(sv) & SVf_OK)
 #define SvOK_off(sv)		(SvFLAGS(sv) &=	~(SVf_OK|SVf_AMAGIC|	\
-						  SVf_IVisUV),		\
+						  SVf_IVisUV|SVf_UTF8),	\
 							SvOOK_off(sv))
-#define SvOK_off_exc_UV(sv)	(SvFLAGS(sv) &=	~(SVf_OK|SVf_AMAGIC),	\
+#define SvOK_off_exc_UV(sv)	(SvFLAGS(sv) &=	~(SVf_OK|SVf_AMAGIC|	\
+						  SVf_UTF8),		\
 							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 SvIOKp_on(sv)		((void)SvOOK_off(sv), SvFLAGS(sv) |= SVp_IOK)
 #define SvNOKp(sv)		(SvFLAGS(sv) & SVp_NOK)
 #define SvNOKp_on(sv)		(SvFLAGS(sv) |= SVp_NOK)
 #define SvPOKp(sv)		(SvFLAGS(sv) & SVp_POK)
 #define SvPOKp_on(sv)		(SvFLAGS(sv) |= SVp_POK)
 
 #define SvIOK(sv)		(SvFLAGS(sv) & SVf_IOK)
-#define SvIOK_on(sv)		(SvOOK_off(sv), \
+#define SvIOK_on(sv)		((void)SvOOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
 #define SvIOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_IOK|SVp_IOK|SVf_IVisUV))
-#define SvIOK_only(sv)		(SvOK_off(sv), \
+#define SvIOK_only(sv)		((void)SvOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
-#define SvIOK_only_UV(sv)	(SvOK_off_exc_UV(sv), \
+#define SvIOK_only_UV(sv)	((void)SvOK_off_exc_UV(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
 
 #define SvIOK_UV(sv)		((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV))	\
@@ -370,7 +563,7 @@ struct xpvio {
 #define SvNOK(sv)		(SvFLAGS(sv) & SVf_NOK)
 #define SvNOK_on(sv)		(SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
 #define SvNOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_NOK|SVp_NOK))
-#define SvNOK_only(sv)		(SvOK_off(sv), \
+#define SvNOK_only(sv)		((void)SvOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
 
 #define SvUTF8(sv)		(SvFLAGS(sv) & SVf_UTF8)
@@ -380,11 +573,15 @@ struct xpvio {
 #define SvPOK(sv)		(SvFLAGS(sv) & SVf_POK)
 #define SvPOK_on(sv)		(SvFLAGS(sv) |= (SVf_POK|SVp_POK))
 #define SvPOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_POK|SVp_POK))
-#define SvPOK_only(sv)		(SvFLAGS(sv) &= ~(SVf_OK|SVf_AMAGIC|SVf_IVisUV),	\
+#define SvPOK_only(sv)		(SvFLAGS(sv) &= ~(SVf_OK|SVf_AMAGIC|	\
+						  SVf_IVisUV|SVf_UTF8),	\
+				    SvFLAGS(sv) |= (SVf_POK|SVp_POK))
+#define SvPOK_only_UTF8(sv)	(SvFLAGS(sv) &= ~(SVf_OK|SVf_AMAGIC|	\
+						  SVf_IVisUV),		\
 				    SvFLAGS(sv) |= (SVf_POK|SVp_POK))
 
 #define SvOOK(sv)		(SvFLAGS(sv) & SVf_OOK)
-#define SvOOK_on(sv)		(SvIOK_off(sv), SvFLAGS(sv) |= SVf_OOK)
+#define SvOOK_on(sv)		((void)SvIOK_off(sv), SvFLAGS(sv) |= SVf_OOK)
 #define SvOOK_off(sv)		(SvOOK(sv) && sv_backoff(sv))
 
 #define SvFAKE(sv)		(SvFLAGS(sv) & SVf_FAKE)
@@ -415,6 +612,8 @@ struct xpvio {
 #define SvAMAGIC_on(sv)		(SvFLAGS(sv) |= SVf_AMAGIC)
 #define SvAMAGIC_off(sv)	(SvFLAGS(sv) &= ~SVf_AMAGIC)
 
+#define SvGAMAGIC(sv)           (SvFLAGS(sv) & (SVs_GMG|SVf_AMAGIC)) 
+
 /*
 #define Gv_AMG(stash) \
         (HV_AMAGICmb(stash) && \
@@ -522,6 +721,7 @@ struct xpvio {
 #define IoIFP(sv)	((XPVIO*)  SvANY(sv))->xio_ifp
 #define IoOFP(sv)	((XPVIO*)  SvANY(sv))->xio_ofp
 #define IoDIRP(sv)	((XPVIO*)  SvANY(sv))->xio_dirp
+#define IoANY(sv)	((XPVIO*)  SvANY(sv))->xio_any
 #define IoLINES(sv)	((XPVIO*)  SvANY(sv))->xio_lines
 #define IoPAGE(sv)	((XPVIO*)  SvANY(sv))->xio_page
 #define IoPAGE_LEN(sv)	((XPVIO*)  SvANY(sv))->xio_page_len
@@ -536,6 +736,38 @@ struct xpvio {
 #define IoTYPE(sv)	((XPVIO*)  SvANY(sv))->xio_type
 #define IoFLAGS(sv)	((XPVIO*)  SvANY(sv))->xio_flags
 
+/* IoTYPE(sv) is a single character telling the type of I/O connection. */
+#define IoTYPE_RDONLY	'<'
+#define IoTYPE_WRONLY	'>'
+#define IoTYPE_RDWR	'+'
+#define IoTYPE_APPEND 	'a'
+#define IoTYPE_PIPE	'|'
+#define IoTYPE_STD	'-'	/* stdin or stdout */
+#define IoTYPE_SOCKET	's'
+#define IoTYPE_CLOSED	' '
+
+/*
+=for apidoc Am|bool|SvTAINTED|SV* sv
+Checks to see if an SV is tainted. Returns TRUE if it is, FALSE if
+not.
+
+=for apidoc Am|void|SvTAINTED_on|SV* sv
+Marks an SV as tainted.
+
+=for apidoc Am|void|SvTAINTED_off|SV* sv
+Untaints an SV. Be I<very> careful with this routine, as it short-circuits
+some of Perl's fundamental security features. XS module authors should not
+use this function unless they fully understand all the implications of
+unconditionally untainting the value. Untainting should be done in the
+standard perl fashion, via a carefully crafted regexp, rather than directly
+untainting variables.
+
+=for apidoc Am|void|SvTAINT|SV* sv
+Taints an SV if tainting is enabled
+
+=cut
+*/
+
 #define SvTAINTED(sv)	  (SvMAGICAL(sv) && sv_tainted(sv))
 #define SvTAINTED_on(sv)  STMT_START{ if(PL_tainting){sv_taint(sv);}   }STMT_END
 #define SvTAINTED_off(sv) STMT_START{ if(PL_tainting){sv_untaint(sv);} }STMT_END
@@ -549,6 +781,35 @@ struct xpvio {
 	}				\
     } STMT_END
 
+/*
+=for apidoc Am|char*|SvPV_force|SV* sv|STRLEN len
+Like <SvPV> but will force the SV into becoming a string (SvPOK).  You want
+force if you are going to update the SvPVX directly.
+
+=for apidoc Am|char*|SvPV|SV* sv|STRLEN len
+Returns a pointer to the string in the SV, or a stringified form of the SV
+if the SV does not contain a string.  Handles 'get' 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.  Handles 'get' magic.
+
+=for apidoc Am|IV|SvIV|SV* sv
+Coerces the given SV to an integer and returns it.
+
+=for apidoc Am|NV|SvNV|SV* sv
+Coerce the given SV to a double and return it.
+
+=for apidoc Am|UV|SvUV|SV* sv
+Coerces the given SV to an unsigned integer and returns it.
+
+=for apidoc Am|bool|SvTRUE|SV* sv
+Returns a boolean indicating whether Perl would evaluate the SV as true or
+false, defined or undefined.  Does not handle 'get' magic.
+
+=cut
+*/
+
 #define SvPV_force(sv, lp) sv_pvn_force(sv, &lp)
 #define SvPV(sv, lp) sv_pvn(sv, &lp)
 #define SvPV_nolen(sv) sv_pv(sv)
@@ -675,8 +936,7 @@ struct xpvio {
     :    SvPOK(sv)						\
 	?   (({XPV *nxpv = (XPV*)SvANY(sv);			\
 	     nxpv &&						\
-	     (*nxpv->xpv_pv > '0' ||				\
-	      nxpv->xpv_cur > 1 ||				\
+	     (nxpv->xpv_cur > 1 ||				\
 	      (nxpv->xpv_cur && *nxpv->xpv_pv != '0')); })	\
 	     ? 1						\
 	     : 0)						\
@@ -711,8 +971,7 @@ struct xpvio {
     ? 0								\
     :    SvPOK(sv)						\
 	?   ((PL_Xpv = (XPV*)SvANY(sv)) &&			\
-	     (*PL_Xpv->xpv_pv > '0' ||				\
-	      PL_Xpv->xpv_cur > 1 ||				\
+	     (PL_Xpv->xpv_cur > 1 ||				\
 	      (PL_Xpv->xpv_cur && *PL_Xpv->xpv_pv != '0'))	\
 	     ? 1						\
 	     : 0)						\
@@ -727,10 +986,45 @@ struct xpvio {
 #endif /* !__GNU__ */
 #endif /* !CRIPPLED_CC */
 
+/*
+=for apidoc Am|SV*|newRV_inc|SV* sv
+
+Creates an RV wrapper for an SV.  The reference count for the original SV is
+incremented.
+
+=cut
+*/
+
 #define newRV_inc(sv)	newRV(sv)
 
 /* the following macros update any magic values this sv is associated with */
 
+/*
+=for apidoc Am|void|SvGETMAGIC|SV* sv
+Invokes C<mg_get> on an SV if it has 'get' magic.  This macro evaluates its
+argument more than once.
+
+=for apidoc Am|void|SvSETMAGIC|SV* sv
+Invokes C<mg_set> on an SV if it has 'set' magic.  This macro evaluates its
+argument more than once.
+
+=for apidoc Am|void|SvSetSV|SV* dsb|SV* ssv
+Calls C<sv_setsv> if dsv is not the same as ssv.  May evaluate arguments
+more than once.
+
+=for apidoc Am|void|SvSetSV_nosteal|SV* dsv|SV* ssv
+Calls a non-destructive version of C<sv_setsv> if dsv is not the same as
+ssv. May evaluate arguments more than once.
+
+=for apidoc Am|void|SvGROW|SV* sv|STRLEN len
+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.
+
+=cut
+*/
+
 #define SvGETMAGIC(x) STMT_START { if (SvGMAGICAL(x)) mg_get(x); } STMT_END
 #define SvSETMAGIC(x) STMT_START { if (SvSMAGICAL(x)) mg_set(x); } STMT_END
 
@@ -776,3 +1070,4 @@ struct xpvio {
 
 #define SvGROW(sv,len) (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
 #define Sv_Grow sv_grow
+