Revert "regen/regcharclass.pl: Make more EBCDIC-friendly"

[perl5.git] / sv.h

diff --git a/sv.h b/sv.h
index 475da61..abcfbb6 100644 (file)
--- a/sv.h
+++ b/sv.h
@@ -57,7 +57,8 @@ typeglob has been assigned.  Assigning to it again will stop it from being
 a typeglob.  SVt_PVLV represents a scalar that delegates to another scalar
 behind the scenes.  It is used, e.g., for the return value of C<substr> and
 for tied hash and array elements.  It can hold any scalar value, including
 a typeglob.  SVt_PVLV represents a scalar that delegates to another scalar
 behind the scenes.  It is used, e.g., for the return value of C<substr> and
 for tied hash and array elements.  It can hold any scalar value, including

-a typeglob. SVt_REGEXP is for regular expressions.  SVt_INVLIST is for Perl
+a typeglob.  SVt_REGEXP is for regular
+expressions.  SVt_INVLIST is for Perl

 core internal use only.
 
 SVt_PVMG represents a "normal" scalar (not a typeglob, regular expression,
 core internal use only.
 
 SVt_PVMG represents a "normal" scalar (not a typeglob, regular expression,


@@ -120,8 +121,14 @@ Type flag for formats.  See L</svtype>.
 Type flag for I/O objects.  See L</svtype>.
 
 =cut
 Type flag for I/O objects.  See L</svtype>.
 
 =cut

+
+  These are ordered so that the simpler types have a lower value; SvUPGRADE
+  doesn't allow you to upgrade from a higher numbered type to a lower numbered
+  one; also there is code that assumes that anything that has as a PV component
+  has a type numbered >= SVt_PV.

 */
 
 */
 

+

 typedef enum {
        SVt_NULL,       /* 0 */
        /* BIND was here, before INVLIST replaced it.  */
 typedef enum {
        SVt_NULL,       /* 0 */
        /* BIND was here, before INVLIST replaced it.  */


@@ -154,7 +161,7 @@ typedef enum {
 
 #ifndef PERL_CORE
 /* Although Fast Boyer Moore tables are now being stored in PVGVs, for most
 
 #ifndef PERL_CORE
 /* Although Fast Boyer Moore tables are now being stored in PVGVs, for most

-   purposes eternal code wanting to consider PVBM probably needs to think of
+   purposes external code wanting to consider PVBM probably needs to think of

    PVMG instead.  */
 #  define SVt_PVBM     SVt_PVMG
 /* Anything wanting to create a reference from clean should ensure that it has
    PVMG instead.  */
 #  define SVt_PVBM     SVt_PVMG
 /* Anything wanting to create a reference from clean should ensure that it has


@@ -291,7 +298,7 @@ to return a meaningful value, or check for NULLness, so it's smaller
 and faster.
 
 =for apidoc Am|void|SvREFCNT_dec|SV* sv
 and faster.
 
 =for apidoc Am|void|SvREFCNT_dec|SV* sv

-Decrements the reference count of the given SV. I<sv> may be NULL.
+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>
 
 =for apidoc Am|void|SvREFCNT_dec_NN|SV* sv
 Same as SvREFCNT_dec, but can only be used if you know I<sv>


@@ -354,6 +361,7 @@ perform the upgrade if necessary.  See C<svtype>.
                                       subroutine in another package. Set the
                                       GvIMPORTED_CV_on() if it needs to be
                                       expanded to a real GV */
                                       subroutine in another package. Set the
                                       GvIMPORTED_CV_on() if it needs to be
                                       expanded to a real GV */

+#define SVpad_NAMELIST SVp_SCREAM  /* AV is a padnamelist */

 #define SVf_IsCOW      0x00010000  /* copy on write (shared hash key if
                                       SvLEN == 0) */
 #define SVs_PADTMP     0x00020000  /* in use as tmp; only if ! SVs_PADMY */
 #define SVf_IsCOW      0x00010000  /* copy on write (shared hash key if
                                       SvLEN == 0) */
 #define SVs_PADTMP     0x00020000  /* in use as tmp; only if ! SVs_PADMY */


@@ -397,21 +405,24 @@ perform the upgrade if necessary.  See C<svtype>.
 
 #define SVf_AMAGIC     0x10000000  /* has magical overloaded methods */
 
 
 #define SVf_AMAGIC     0x10000000  /* has magical overloaded methods */
 

+/* note that SVf_AMAGIC is now only set on stashes, so this bit is free
+ * for non-HV SVs */
+

 /* Ensure this value does not clash with the GV_ADD* flags in gv.h: */
 #define SVf_UTF8        0x20000000  /* SvPV is UTF-8 encoded
                                       This is also set on RVs whose overloaded
                                       stringification is UTF-8. This might
                                       only happen as a side effect of SvPV() */
 /* Ensure this value does not clash with the GV_ADD* flags in gv.h: */
 #define SVf_UTF8        0x20000000  /* SvPV is UTF-8 encoded
                                       This is also set on RVs whose overloaded
                                       stringification is UTF-8. This might
                                       only happen as a side effect of SvPV() */

-                                          
-
-/* Some private flags. */
+/* PVHV */
+#define SVphv_SHAREKEYS 0x20000000  /* PVHV keys live on shared string table */

 
 /* PVAV could probably use 0x2000000 without conflict. I assume that PVFM can
    be UTF-8 encoded, and PVCVs could well have UTF-8 prototypes. PVIOs haven't
    been restructured, so sometimes get used as string buffers.  */
 
 
 /* PVAV could probably use 0x2000000 without conflict. I assume that PVFM can
    be UTF-8 encoded, and PVCVs could well have UTF-8 prototypes. PVIOs haven't
    been restructured, so sometimes get used as string buffers.  */
 

-/* PVHV */
-#define SVphv_SHAREKEYS 0x20000000  /* PVHV keys live on shared string table */
+
+/* Some private flags. */
+

 
 /* PVNV, PVMG only, and only used in pads. Should be safe to test on any scalar
    SV, as the core is careful to avoid setting both.
 
 /* PVNV, PVMG only, and only used in pads. Should be safe to test on any scalar
    SV, as the core is careful to avoid setting both.


@@ -470,7 +481,6 @@ union _xnvu {
        U32 xlow;
        U32 xhigh;
     }      xpad_cop_seq;       /* used by pad.c for cop_sequence */
        U32 xlow;
        U32 xhigh;
     }      xpad_cop_seq;       /* used by pad.c for cop_sequence */

-    I32            xbm_useful;

 };
 
 union _xivu {
 };
 
 union _xivu {


@@ -483,7 +493,7 @@ union _xmgu {
     MAGIC*  xmg_magic;         /* linked list of magicalness */
     HV*            xmg_ourstash;       /* Stash for our (when SvPAD_OUR is true) */
     STRLEN  xmg_hash_index;    /* used while freeing hash entries */
     MAGIC*  xmg_magic;         /* linked list of magicalness */
     HV*            xmg_ourstash;       /* Stash for our (when SvPAD_OUR is true) */
     STRLEN  xmg_hash_index;    /* used while freeing hash entries */

-};
+};                             /* also used by PadnamelistMAXNAMED */

 
 struct xpv {
     _XPV_HEAD;
 
 struct xpv {
     _XPV_HEAD;


@@ -520,7 +530,10 @@ struct xpvlv {
     _XPV_HEAD;
     union _xivu xiv_u;
     union _xnvu xnv_u;
     _XPV_HEAD;
     union _xivu xiv_u;
     union _xnvu xnv_u;

-    STRLEN     xlv_targoff;
+    union {
+       STRLEN  xlvu_targoff;
+       SSize_t xlvu_stargoff;
+    } xlv_targoff_u;

     STRLEN     xlv_targlen;
     SV*                xlv_targ;
     char       xlv_type;       /* k=keys .=pos x=substr v=vec /=join/re
     STRLEN     xlv_targlen;
     SV*                xlv_targ;
     char       xlv_type;       /* k=keys .=pos x=substr v=vec /=join/re


@@ -528,6 +541,15 @@ struct xpvlv {
     char       xlv_flags;      /* 1 = negative offset  2 = negative len */
 };
 
     char       xlv_flags;      /* 1 = negative offset  2 = negative len */
 };
 

+#define xlv_targoff xlv_targoff_u.xlvu_targoff
+
+struct xpvinvlist {
+    _XPV_HEAD;
+    IV          prev_index;
+    STRLEN     iterator;
+    bool       is_offset;      /* */
+};
+

 /* This structure works in 3 ways - regular scalar, GV with GP, or fast
    Boyer-Moore.  */
 struct xpvgv {
 /* This structure works in 3 ways - regular scalar, GV with GP, or fast
    Boyer-Moore.  */
 struct xpvgv {


@@ -628,7 +650,7 @@ double.  Checks the B<private> setting.  Use C<SvNIOK> instead.
 Unsets the NV/IV status of an SV.
 
 =for apidoc Am|U32|SvOK|SV* sv
 Unsets the NV/IV status of an SV.
 
 =for apidoc Am|U32|SvOK|SV* sv

-Returns a U32 value indicating whether the value is defined. This is
+Returns a U32 value indicating whether the value is defined.  This is

 only meaningful for scalars.
 
 =for apidoc Am|U32|SvIOKp|SV* sv
 only meaningful for scalars.
 
 =for apidoc Am|U32|SvIOKp|SV* sv


@@ -734,7 +756,8 @@ Only use when you are sure SvNOK is true.  See also C<SvNV()>.
 
 =for apidoc Am|char*|SvPVX|SV* sv
 Returns a pointer to the physical string in the SV.  The SV must contain a
 
 =for apidoc Am|char*|SvPVX|SV* sv
 Returns a pointer to the physical string in the SV.  The SV must contain a

-string. Prior to 5.9.3 it is not safe to execute this macro unless the SV's
+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
 type >= SVt_PV.
 
 This is also used to store the name of an autoloaded subroutine in an XS


@@ -750,7 +773,7 @@ attributable to C<SvOOK>.  See C<SvCUR>.
 =for apidoc Am|char*|SvEND|SV* sv
 Returns a pointer to the spot just after the last character in
 the string which is in the SV, where there is usually a trailing
 =for apidoc Am|char*|SvEND|SV* sv
 Returns a pointer to the spot just after the last character in
 the string which is in the SV, where there is usually a trailing

-null (even though Perl scalars do not strictly require it).
+C<NUL> byte (even though Perl scalars do not strictly require it).

 See C<SvCUR>.  Access the character as *(SvEND(sv)).
 
 Warning: If C<SvCUR> is equal to C<SvLEN>, then C<SvEND> points to
 See C<SvCUR>.  Access the character as *(SvEND(sv)).
 
 Warning: If C<SvCUR> is equal to C<SvLEN>, then C<SvEND> points to


@@ -936,6 +959,7 @@ in gv.h: */
 #define HvAMAGIC_off(hv)       (SvFLAGS(hv) &=~ SVf_AMAGIC)
 
 
 #define HvAMAGIC_off(hv)       (SvFLAGS(hv) &=~ SVf_AMAGIC)
 
 

+/* "nog" means "doesn't have get magic" */

 #define SvPOK_nog(sv)          ((SvFLAGS(sv) & (SVf_POK|SVs_GMG)) == SVf_POK)
 #define SvIOK_nog(sv)          ((SvFLAGS(sv) & (SVf_IOK|SVs_GMG)) == SVf_IOK)
 #define SvUOK_nog(sv)          ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV|SVs_GMG)) == (SVf_IOK|SVf_IVisUV))
 #define SvPOK_nog(sv)          ((SvFLAGS(sv) & (SVf_POK|SVs_GMG)) == SVf_POK)
 #define SvIOK_nog(sv)          ((SvFLAGS(sv) & (SVf_IOK|SVs_GMG)) == SVf_IOK)
 #define SvUOK_nog(sv)          ((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV|SVs_GMG)) == (SVf_IOK|SVf_IVisUV))


@@ -1060,27 +1084,30 @@ sv_force_normal does nothing.
 
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
 #  define SvVALID(sv)          ({ const SV *const _svvalid = (const SV*)(sv); \
 
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
 #  define SvVALID(sv)          ({ const SV *const _svvalid = (const SV*)(sv); \

-                                  if (SvFLAGS(_svvalid) & SVpbm_VALID) \
+                                  if (SvFLAGS(_svvalid) & SVpbm_VALID && !SvSCREAM(_svvalid)) \

                                       assert(!isGV_with_GP(_svvalid)); \
                                   (SvFLAGS(_svvalid) & SVpbm_VALID);   \
                                })
 #  define SvVALID_on(sv)       ({ SV *const _svvalid = MUTABLE_SV(sv); \
                                   assert(!isGV_with_GP(_svvalid));     \
                                       assert(!isGV_with_GP(_svvalid)); \
                                   (SvFLAGS(_svvalid) & SVpbm_VALID);   \
                                })
 #  define SvVALID_on(sv)       ({ SV *const _svvalid = MUTABLE_SV(sv); \
                                   assert(!isGV_with_GP(_svvalid));     \

+                                  assert(!SvSCREAM(_svvalid));         \

                                   (SvFLAGS(_svvalid) |= SVpbm_VALID);  \
                                })
 #  define SvVALID_off(sv)      ({ SV *const _svvalid = MUTABLE_SV(sv); \
                                   assert(!isGV_with_GP(_svvalid));     \
                                   (SvFLAGS(_svvalid) |= SVpbm_VALID);  \
                                })
 #  define SvVALID_off(sv)      ({ SV *const _svvalid = MUTABLE_SV(sv); \
                                   assert(!isGV_with_GP(_svvalid));     \

+                                  assert(!SvSCREAM(_svvalid));         \

                                   (SvFLAGS(_svvalid) &= ~SVpbm_VALID); \
                                })
 
 #  define SvTAIL(sv)   ({ const SV *const _svtail = (const SV *)(sv);  \
                                   (SvFLAGS(_svvalid) &= ~SVpbm_VALID); \
                                })
 
 #  define SvTAIL(sv)   ({ const SV *const _svtail = (const SV *)(sv);  \

-                           assert(SvTYPE(_svtail) != SVt_PVAV);                \
-                           assert(SvTYPE(_svtail) != SVt_PVHV);                \
+                           assert(SvTYPE(_svtail) != SVt_PVAV);        \
+                           assert(SvTYPE(_svtail) != SVt_PVHV);        \
+                           assert(!SvSCREAM(_svtail));                 \

                            (SvFLAGS(sv) & (SVpbm_TAIL|SVpbm_VALID))    \
                                == (SVpbm_TAIL|SVpbm_VALID);            \
                        })
 #else
                            (SvFLAGS(sv) & (SVpbm_TAIL|SVpbm_VALID))    \
                                == (SVpbm_TAIL|SVpbm_VALID);            \
                        })
 #else

-#  define SvVALID(sv)          (SvFLAGS(sv) & SVpbm_VALID)
+#  define SvVALID(sv)          ((SvFLAGS(sv) & SVpbm_VALID) && !SvSCREAM(sv))

 #  define SvVALID_on(sv)       (SvFLAGS(sv) |= SVpbm_VALID)
 #  define SvVALID_off(sv)      (SvFLAGS(sv) &= ~SVpbm_VALID)
 #  define SvTAIL(sv)       ((SvFLAGS(sv) & (SVpbm_TAIL|SVpbm_VALID))   \
 #  define SvVALID_on(sv)       (SvFLAGS(sv) |= SVpbm_VALID)
 #  define SvVALID_off(sv)      (SvFLAGS(sv) &= ~SVpbm_VALID)
 #  define SvTAIL(sv)       ((SvFLAGS(sv) & (SVpbm_TAIL|SVpbm_VALID))   \


@@ -1335,7 +1362,7 @@ sv_force_normal does nothing.
                     assert(SvTYPE(sv) >= SVt_PV);                      \
                     if (SvLEN(sv)) {                                   \
                         assert(!SvROK(sv));                            \
                     assert(SvTYPE(sv) >= SVt_PV);                      \
                     if (SvLEN(sv)) {                                   \
                         assert(!SvROK(sv));                            \

-                        if(SvOOK(sv)) {                                \
+                        if(UNLIKELY(SvOOK(sv))) {                      \

                             STRLEN zok;                                \
                             SvOOK_offset(sv, zok);                     \
                             SvPV_set(sv, SvPVX_mutable(sv) - zok);     \
                             STRLEN zok;                                \
                             SvOOK_offset(sv, zok);                     \
                             SvPV_set(sv, SvPVX_mutable(sv) - zok);     \


@@ -1367,13 +1394,13 @@ sv_force_normal does nothing.
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
 #  define BmUSEFUL(sv)                                                 \
        (*({ SV *const _bmuseful = MUTABLE_SV(sv);                      \
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
 #  define BmUSEFUL(sv)                                                 \
        (*({ SV *const _bmuseful = MUTABLE_SV(sv);                      \

-           assert(SvTYPE(_bmuseful) == SVt_PVMG);                      \
+           assert(SvTYPE(_bmuseful) >= SVt_PVIV);                      \

            assert(SvVALID(_bmuseful));                                 \
            assert(SvVALID(_bmuseful));                                 \

-           assert(!SvNOK(_bmuseful));                                  \
-           &(((XPVMG*) SvANY(_bmuseful))->xnv_u.xbm_useful);           \
+           assert(!SvIOK(_bmuseful));                                  \
+           &(((XPVIV*) SvANY(_bmuseful))->xiv_u.xivu_iv);              \

         }))
 #else
         }))
 #else

-#  define BmUSEFUL(sv)         ((XPVMG*) SvANY(sv))->xnv_u.xbm_useful
+#  define BmUSEFUL(sv)          ((XPVIV*) SvANY(sv))->xiv_u.xivu_iv

 
 #endif
 
 
 #endif
 


@@ -1387,6 +1414,7 @@ sv_force_normal does nothing.
 #define LvTYPE(sv)     ((XPVLV*)  SvANY(sv))->xlv_type
 #define LvTARG(sv)     ((XPVLV*)  SvANY(sv))->xlv_targ
 #define LvTARGOFF(sv)  ((XPVLV*)  SvANY(sv))->xlv_targoff
 #define LvTYPE(sv)     ((XPVLV*)  SvANY(sv))->xlv_type
 #define LvTARG(sv)     ((XPVLV*)  SvANY(sv))->xlv_targ
 #define LvTARGOFF(sv)  ((XPVLV*)  SvANY(sv))->xlv_targoff

+#define LvSTARGOFF(sv) ((XPVLV*)  SvANY(sv))->xlv_targoff_u.xlvu_stargoff

 #define LvTARGLEN(sv)  ((XPVLV*)  SvANY(sv))->xlv_targlen
 #define LvFLAGS(sv)    ((XPVLV*)  SvANY(sv))->xlv_flags
 
 #define LvTARGLEN(sv)  ((XPVLV*)  SvANY(sv))->xlv_targlen
 #define LvFLAGS(sv)    ((XPVLV*)  SvANY(sv))->xlv_flags
 


@@ -1431,7 +1459,7 @@ Marks an SV as tainted if tainting is enabled.
 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
 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
+unconditionally untainting the value.  Untainting should be done in the

 standard perl fashion, via a carefully crafted regexp, rather than directly
 untainting variables.
 
 standard perl fashion, via a carefully crafted regexp, rather than directly
 untainting variables.
 


@@ -1447,18 +1475,18 @@ attention to precisely which outputs are influenced by which inputs.
 
 #define sv_taint(sv)     sv_magic((sv), NULL, PERL_MAGIC_taint, NULL, 0)
 
 
 #define sv_taint(sv)     sv_magic((sv), NULL, PERL_MAGIC_taint, NULL, 0)
 

-#if NO_TAINT_SUPPORT
+#ifdef NO_TAINT_SUPPORT

 #   define SvTAINTED(sv) 0
 #else
 #   define SvTAINTED(sv)         (SvMAGICAL(sv) && sv_tainted(sv))
 #endif
 #   define SvTAINTED(sv) 0
 #else
 #   define SvTAINTED(sv)         (SvMAGICAL(sv) && sv_tainted(sv))
 #endif

-#define SvTAINTED_on(sv)  STMT_START{ if(TAINTING_get){sv_taint(sv);}   }STMT_END
-#define SvTAINTED_off(sv) STMT_START{ if(TAINTING_get){sv_untaint(sv);} }STMT_END
+#define SvTAINTED_on(sv)  STMT_START{ if(UNLIKELY(TAINTING_get)){sv_taint(sv);}   }STMT_END
+#define SvTAINTED_off(sv) STMT_START{ if(UNLIKELY(TAINTING_get)){sv_untaint(sv);} }STMT_END

 
 #define SvTAINT(sv)                    \
     STMT_START {                       \
 
 #define SvTAINT(sv)                    \
     STMT_START {                       \

-       if (TAINTING_get) {             \
-           if (TAINT_get)              \
+       if (UNLIKELY(TAINTING_get)) {   \
+           if (UNLIKELY(TAINT_get))    \

                SvTAINTED_on(sv);       \
        }                               \
     } STMT_END
                SvTAINTED_on(sv);       \
        }                               \
     } STMT_END


@@ -1470,7 +1498,7 @@ 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
 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
+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)">.
 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)">.


@@ -1481,13 +1509,15 @@ 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
 the SV if the SV does not contain a string.  The SV may cache the
 =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.  The SV may cache the

-stringified version becoming C<SvPOK>.  Handles 'get' magic.  See also
-C<SvPVx> for a version which guarantees to evaluate sv only once.
+stringified version becoming C<SvPOK>.  Handles 'get' magic.  The
+C<len> variable will be set to the length of the string (this is a macro, so
+don't use C<&len>). 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
 
 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
+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
 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


@@ -1594,8 +1624,8 @@ Like C<SvPV>, but converts sv to byte representation first if necessary.
 Guarantees to evaluate sv only once; use the more efficient C<SvPVbyte>
 otherwise.
 
 Guarantees to evaluate sv only once; use the more efficient C<SvPVbyte>
 otherwise.
 

-=for apidoc Am|bool|SvIsCOW|SV* sv
-Returns a boolean indicating whether the SV is Copy-On-Write (either shared
+=for apidoc Am|U32|SvIsCOW|SV* sv
+Returns a U32 value indicating whether the SV is Copy-On-Write (either shared

 hash key scalars, or full Copy On Write scalars if 5.9.0 is configured for
 COW).
 
 hash key scalars, or full Copy On Write scalars if 5.9.0 is configured for
 COW).
 


@@ -1677,6 +1707,7 @@ Like sv_utf8_upgrade, but doesn't do magic on C<sv>.
     (SvPOK_nog(sv) \
      ? SvPVX(sv) : sv_2pv_flags(sv, 0, SV_GMAGIC))
 
     (SvPOK_nog(sv) \
      ? SvPVX(sv) : sv_2pv_flags(sv, 0, SV_GMAGIC))
 

+/* "_nomg" in these defines means no mg_get() */

 #define SvPV_nomg_nolen(sv) \
     (SvPOK_nog(sv) \
      ? SvPVX(sv) : sv_2pv_flags(sv, 0, 0))
 #define SvPV_nomg_nolen(sv) \
     (SvPOK_nog(sv) \
      ? SvPVX(sv) : sv_2pv_flags(sv, 0, 0))


@@ -1727,9 +1758,9 @@ Like sv_utf8_upgrade, but doesn't do magic on C<sv>.
 #define SvPVutf8x_force(sv, lp) sv_pvutf8n_force(sv, &lp)
 #define SvPVbytex_force(sv, lp) sv_pvbyten_force(sv, &lp)
 
 #define SvPVutf8x_force(sv, lp) sv_pvutf8n_force(sv, &lp)
 #define SvPVbytex_force(sv, lp) sv_pvbyten_force(sv, &lp)
 

-#define SvTRUE(sv)        ((sv) && (SvGMAGICAL(sv) ? sv_2bool(sv) : SvTRUE_common(sv, sv_2bool_nomg(sv))))
-#define SvTRUE_nomg(sv)   ((sv) && (                                SvTRUE_common(sv, sv_2bool_nomg(sv))))
-#define SvTRUE_NN(sv)              (SvGMAGICAL(sv) ? sv_2bool(sv) : SvTRUE_common(sv, sv_2bool_nomg(sv)))
+#define SvTRUE(sv)        (LIKELY(sv) && (UNLIKELY(SvGMAGICAL(sv)) ? sv_2bool(sv) : SvTRUE_common(sv, sv_2bool_nomg(sv))))
+#define SvTRUE_nomg(sv)   (LIKELY(sv) && (                                SvTRUE_common(sv, sv_2bool_nomg(sv))))
+#define SvTRUE_NN(sv)              (UNLIKELY(SvGMAGICAL(sv)) ? sv_2bool(sv) : SvTRUE_common(sv, sv_2bool_nomg(sv)))

 #define SvTRUE_nomg_NN(sv) (                                        SvTRUE_common(sv, sv_2bool_nomg(sv)))
 #define SvTRUE_common(sv,fallback) (                   \
       !SvOK(sv)                                                \
 #define SvTRUE_nomg_NN(sv) (                                        SvTRUE_common(sv, sv_2bool_nomg(sv)))
 #define SvTRUE_common(sv,fallback) (                   \
       !SvOK(sv)                                                \


@@ -1880,12 +1911,6 @@ mg.c:1024: warning: left-hand operand of comma expression has no effect
    /* 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)
    /* 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
 #   define CAN_COW_MASK        (SVf_POK|SVf_ROK|SVp_POK|SVf_FAKE| \
                         SVf_OOK|SVf_BREAK|SVf_READONLY)
 #  endif


@@ -1954,12 +1979,11 @@ mg.c:1024: warning: left-hand operand of comma expression has no effect
 #define sv_catpvn_nomg_maybeutf8(dsv, sstr, slen, is_utf8) \
        sv_catpvn_flags(dsv, sstr, slen, (is_utf8)?SV_CATUTF8:SV_CATBYTES)
 
 #define sv_catpvn_nomg_maybeutf8(dsv, sstr, slen, is_utf8) \
        sv_catpvn_flags(dsv, sstr, slen, (is_utf8)?SV_CATUTF8:SV_CATBYTES)
 

-#ifdef PERL_CORE
+#if defined(PERL_CORE) || defined(PERL_EXT)

 # define sv_or_pv_len_utf8(sv, pv, bytelen)          \
     (SvGAMAGIC(sv)                                    \
        ? utf8_length((U8 *)(pv), (U8 *)(pv)+(bytelen)) \
        : sv_len_utf8(sv))
 # define sv_or_pv_len_utf8(sv, pv, bytelen)          \
     (SvGAMAGIC(sv)                                    \
        ? utf8_length((U8 *)(pv), (U8 *)(pv)+(bytelen)) \
        : sv_len_utf8(sv))

-# define sv_or_pv_pos_u2b(sv,s,p,lp) S_sv_or_pv_pos_u2b(aTHX_ sv,s,p,lp)

 #endif
 
 /*
 #endif
 
 /*


@@ -1989,7 +2013,7 @@ after modifying a scalar, in case it is a magical variable like C<$|>
 or a tied variable (it calls C<STORE>).  This macro evaluates its
 argument more than once.
 
 or a tied variable (it calls C<STORE>).  This macro evaluates its
 argument more than once.
 

-=for apidoc Am|void|SvSetSV|SV* dsb|SV* ssv
+=for apidoc Am|void|SvSetSV|SV* dsv|SV* ssv

 Calls C<sv_setsv> if dsv is not the same as ssv.  May evaluate arguments
 more than once.
 
 Calls C<sv_setsv> if dsv is not the same as ssv.  May evaluate arguments
 more than once.
 


@@ -1997,7 +2021,7 @@ more than once.
 Calls a non-destructive version of C<sv_setsv> if dsv is not the same as
 ssv.  May evaluate arguments more than once.
 
 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|SvSetMagicSV|SV* dsb|SV* ssv
+=for apidoc Am|void|SvSetMagicSV|SV* dsv|SV* ssv

 Like C<SvSetSV>, but does any set magic required afterwards.
 
 =for apidoc Am|void|SvSetMagicSV_nosteal|SV* dsv|SV* ssv
 Like C<SvSetSV>, but does any set magic required afterwards.
 
 =for apidoc Am|void|SvSetMagicSV_nosteal|SV* dsv|SV* ssv


@@ -2020,8 +2044,9 @@ has been loaded.
 =for apidoc Am|char *|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
 =for apidoc Am|char *|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. SV must be of type >= SVt_PV. One
+C<NUL> character).  Calls C<sv_grow> to perform the expansion if necessary.
+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
 alternative is to call C<sv_grow> if you are not sure of the type of SV.
 
 =cut


@@ -2032,19 +2057,19 @@ alternative is to call C<sv_grow> if you are not sure of the type of SV.
 #define SvUNLOCK(sv) PL_unlockhook(aTHX_ sv)
 #define SvDESTROYABLE(sv) PL_destroyhook(aTHX_ sv)
 
 #define SvUNLOCK(sv) PL_unlockhook(aTHX_ sv)
 #define SvDESTROYABLE(sv) PL_destroyhook(aTHX_ sv)
 

-#define SvGETMAGIC(x) ((void)(SvGMAGICAL(x) && mg_get(x)))
-#define SvSETMAGIC(x) STMT_START { if (SvSMAGICAL(x)) mg_set(x); } STMT_END
+#define SvGETMAGIC(x) ((void)(UNLIKELY(SvGMAGICAL(x)) && mg_get(x)))
+#define SvSETMAGIC(x) STMT_START { if (UNLIKELY(SvSMAGICAL(x))) mg_set(x); } STMT_END

 
 #define SvSetSV_and(dst,src,finally) \
        STMT_START {                                    \
 
 #define SvSetSV_and(dst,src,finally) \
        STMT_START {                                    \

-           if ((dst) != (src)) {                       \
+           if (LIKELY((dst) != (src))) {               \

                sv_setsv(dst, src);                     \
                finally;                                \
            }                                           \
        } STMT_END
 #define SvSetSV_nosteal_and(dst,src,finally) \
        STMT_START {                                    \
                sv_setsv(dst, src);                     \
                finally;                                \
            }                                           \
        } STMT_END
 #define SvSetSV_nosteal_and(dst,src,finally) \
        STMT_START {                                    \

-           if ((dst) != (src)) {                       \
+           if (LIKELY((dst) != (src))) {                       \

                sv_setsv_flags(dst, src, SV_GMAGIC | SV_NOSTEAL | SV_DO_COW_SVSETSV);   \
                finally;                                \
            }                                           \
                sv_setsv_flags(dst, src, SV_GMAGIC | SV_NOSTEAL | SV_DO_COW_SVSETSV);   \
                finally;                                \
            }                                           \


@@ -2112,7 +2137,7 @@ See also C<PL_sv_yes> and C<PL_sv_no>.
         == (SVt_PVLV|SVf_FAKE))
 
 
         == (SVt_PVLV|SVf_FAKE))
 
 

-#ifdef PERL_NEW_COPY_ON_WRITE
+#ifdef PERL_ANY_COW

 # define SvGROW(sv,len) \
        (SvIsCOW(sv) || SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
 #else
 # define SvGROW(sv,len) \
        (SvIsCOW(sv) || SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
 #else


@@ -2138,7 +2163,8 @@ struct clone_params {
 /*
 =for apidoc Am|SV*|newSVpvn_utf8|NULLOK const char* s|STRLEN len|U32 utf8
 
 /*
 =for apidoc Am|SV*|newSVpvn_utf8|NULLOK const char* s|STRLEN len|U32 utf8
 

-Creates a new SV and copies a string into it.  If utf8 is true, calls
+Creates a new SV and copies a string (which may contain C<NUL> (C<\0>)
+characters) into it.  If utf8 is true, calls

 C<SvUTF8_on> on the new SV.  Implemented as a wrapper around C<newSVpvn_flags>.
 
 =cut
 C<SvUTF8_on> on the new SV.  Implemented as a wrapper around C<newSVpvn_flags>.
 
 =cut