s/PERL_COPY_ON_WRITE/PERL_OLD_COPY_ON_WRITE/g

p4raw-id: //depot/perl@24755

16 files changed, 61 insertions, 61 deletions

diff --git a/dump.c b/dump.c
index ec1ead9f85..ee352b94fa 100644
--- a/dump.c
+++ b/dump.c
@@ -1281,7 +1281,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
     if ((type >= SVt_PVIV && type != SVt_PVAV && type != SVt_PVHV)
 	|| type == SVt_IV) {
 	if (SvIsUV(sv)
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	               || SvIsCOW(sv)
 #endif
 	                             )
@@ -1290,7 +1290,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 	    Perl_dump_indent(aTHX_ level, file, "  IV = %"IVdf, (IV)SvIVX(sv));
 	if (SvOOK(sv))
 	    PerlIO_printf(file, "  (OFFSET)");
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	if (SvIsCOW_shared_hash(sv))
 	    PerlIO_printf(file, "  (HASH)");
 	else if (SvIsCOW_normal(sv))
diff --git a/embed.fnc b/embed.fnc
index ee43d9028e..b34d59e6f9 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -965,7 +965,7 @@ Ap	|void	|sys_intern_init
 Ap	|char *	|custom_op_name	|NN const OP* op
 Ap	|char *	|custom_op_desc	|NN const OP* op
 
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 pMX	|int	|sv_release_IVX	|SV *sv
 #endif
 
@@ -1269,7 +1269,7 @@ s	|bool	|utf8_mg_pos	|NN SV *sv|NN MAGIC **mgp|NN STRLEN **cachep \
 s	|bool	|utf8_mg_pos_init	|NN SV *sv|NN MAGIC **mgp \
 				|NN STRLEN **cachep|I32 i|I32 offsetp \
 				|NN const U8 *s|NN const U8 *start
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 sM	|void	|sv_release_COW	|SV *sv|const char *pvx|STRLEN cur|STRLEN len \
 				|U32 hash|SV *after
 #endif
@@ -1361,7 +1361,7 @@ Apd	|char*	|sv_pvn_force_flags|SV* sv|NN STRLEN* lp|I32 flags
 Apd	|void	|sv_copypv	|NN SV* dsv|NN SV* ssv
 Ap	|char*	|my_atof2	|NN const char *s|NN NV* value
 Apn	|int	|my_socketpair	|int family|int type|int protocol|int fd[2]
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 pMXE	|SV*	|sv_setsv_cow	|SV* dsv|SV* ssv
 #endif
 
diff --git a/embed.h b/embed.h
index 6613bbb0b6..7b39af5a5c 100644
--- a/embed.h
+++ b/embed.h
@@ -1002,7 +1002,7 @@
 #endif
 #define custom_op_name		Perl_custom_op_name
 #define custom_op_desc		Perl_custom_op_desc
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 #ifdef PERL_CORE
 #define sv_release_IVX		Perl_sv_release_IVX
 #endif
@@ -1331,7 +1331,7 @@
 #define utf8_mg_pos		S_utf8_mg_pos
 #define utf8_mg_pos_init	S_utf8_mg_pos_init
 #endif
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 #ifdef PERL_CORE
 #define sv_release_COW		S_sv_release_COW
 #endif
@@ -1431,7 +1431,7 @@
 #define sv_copypv		Perl_sv_copypv
 #define my_atof2		Perl_my_atof2
 #define my_socketpair		Perl_my_socketpair
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 #if defined(PERL_CORE) || defined(PERL_EXT)
 #define sv_setsv_cow		Perl_sv_setsv_cow
 #endif
@@ -2991,7 +2991,7 @@
 #endif
 #define custom_op_name(a)	Perl_custom_op_name(aTHX_ a)
 #define custom_op_desc(a)	Perl_custom_op_desc(aTHX_ a)
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 #ifdef PERL_CORE
 #define sv_release_IVX(a)	Perl_sv_release_IVX(aTHX_ a)
 #endif
@@ -3319,7 +3319,7 @@
 #define utf8_mg_pos(a,b,c,d,e,f,g,h,i)	S_utf8_mg_pos(aTHX_ a,b,c,d,e,f,g,h,i)
 #define utf8_mg_pos_init(a,b,c,d,e,f,g)	S_utf8_mg_pos_init(aTHX_ a,b,c,d,e,f,g)
 #endif
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 #ifdef PERL_CORE
 #define sv_release_COW(a,b,c,d,e,f)	S_sv_release_COW(aTHX_ a,b,c,d,e,f)
 #endif
@@ -3419,7 +3419,7 @@
 #define sv_copypv(a,b)		Perl_sv_copypv(aTHX_ a,b)
 #define my_atof2(a,b)		Perl_my_atof2(aTHX_ a,b)
 #define my_socketpair		Perl_my_socketpair
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 #if defined(PERL_CORE) || defined(PERL_EXT)
 #define sv_setsv_cow(a,b)	Perl_sv_setsv_cow(aTHX_ a,b)
 #endif
diff --git a/ext/B/t/bytecode.t b/ext/B/t/bytecode.t
index 12450b0121..55a4c2f0ab 100644
--- a/ext/B/t/bytecode.t
+++ b/ext/B/t/bytecode.t
@@ -19,7 +19,7 @@ BEGIN {
         print "1..0 # Skip -- Perl configured without B module\n";
         exit 0;
     }
-    if ($Config{ccflags} =~ /-DPERL_COPY_ON_WRITE/) {
+    if ($Config{ccflags} =~ /-DPERL_OLD_COPY_ON_WRITE/) {
 	print "1..0 # skip - no COW for now\n";
 	exit 0;
     }
diff --git a/ext/Devel/PPPort/parts/embed.fnc b/ext/Devel/PPPort/parts/embed.fnc
index 795f3fe6c5..c33d6cd544 100644
--- a/ext/Devel/PPPort/parts/embed.fnc
+++ b/ext/Devel/PPPort/parts/embed.fnc
@@ -956,7 +956,7 @@ Ap	|void	|sys_intern_init
 Ap	|char *	|custom_op_name	|OP* op
 Ap	|char *	|custom_op_desc	|OP* op
 
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 pMX	|int	|sv_release_IVX	|SV *sv
 #endif
 
@@ -1224,7 +1224,7 @@ s	|SV*	|gv_share	|SV *sv|CLONE_PARAMS *param
 #  endif
 s	|bool	|utf8_mg_pos	|SV *sv|MAGIC **mgp|STRLEN **cachep|I32 i|I32 *offsetp|I32 uoff|U8 **sp|U8 *start|U8 *send
 s	|bool	|utf8_mg_pos_init	|SV *sv|MAGIC **mgp|STRLEN **cachep|I32 i|I32 *offsetp|U8 *s|U8 *start
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 sM	|void	|sv_release_COW	|SV *sv|char *pvx|STRLEN cur|STRLEN len \
 				|U32 hash|SV *after
 #endif
@@ -1311,7 +1311,7 @@ Apd	|char*	|sv_2pv_flags	|SV* sv|STRLEN* lp|I32 flags
 Apd	|void	|sv_copypv	|SV* dsv|SV* ssv
 Ap	|char*	|my_atof2	|const char *s|NV* value
 Apn	|int	|my_socketpair	|int family|int type|int protocol|int fd[2]
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 pMXE	|SV*	|sv_setsv_cow	|SV* dsv|SV* ssv
 #endif
 
diff --git a/makedef.pl b/makedef.pl
index 3891b02528..0174ca0dd1 100644
--- a/makedef.pl
+++ b/makedef.pl
@@ -599,7 +599,7 @@ else {
 		    )];
 }
 
-unless ($define{'PERL_COPY_ON_WRITE'}) {
+unless ($define{'PERL_OLD_COPY_ON_WRITE'}) {
     skip_symbols [qw(
 		    Perl_sv_setsv_cow
 		    Perl_sv_release_IVX
diff --git a/mg.c b/mg.c
index 819b01291d..5a224e2942 100644
--- a/mg.c
+++ b/mg.c
@@ -81,7 +81,7 @@ S_save_magic(pTHX_ I32 mgs_ix, SV *sv)
 {
     MGS* mgs;
     assert(SvMAGICAL(sv));
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     /* Turning READONLY off for a copy-on-write scalar is a bad idea.  */
     if (SvIsCOW(sv))
       sv_force_normal(sv);
@@ -2643,7 +2643,7 @@ restore_magic(pTHX_ const void *p)
 
     if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv))
     {
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	/* While magic was saved (and off) sv_setsv may well have seen
 	   this SV as a prime candidate for COW.  */
 	if (SvIsCOW(sv))
diff --git a/pad.c b/pad.c
index e4ec019ff7..e821069a8b 100644
--- a/pad.c
+++ b/pad.c
@@ -1235,7 +1235,7 @@ Perl_pad_free(pTHX_ PADOFFSET po)
 #ifdef USE_ITHREADS
 	/* SV could be a shared hash key (eg bugid #19022) */
 	if (
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    !SvIsCOW(PL_curpad[po])
 #else
 	    !SvFAKE(PL_curpad[po])
diff --git a/pp_ctl.c b/pp_ctl.c
index 0d0899a7e9..be41b9ec7b 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -233,7 +233,7 @@ PP(pp_substcont)
 	    }
 	    cx->sb_rxtainted |= RX_MATCH_TAINTED(rx);
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    if (SvIsCOW(targ)) {
 		sv_force_normal_flags(targ, SV_COW_DROP_PV);
 	    } else
@@ -308,7 +308,7 @@ Perl_rxres_save(pTHX_ void **rsp, REGEXP *rx)
     U32 i;
 
     if (!p || p[1] < rx->nparens) {
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	i = 7 + rx->nparens * 2;
 #else
 	i = 6 + rx->nparens * 2;
@@ -323,7 +323,7 @@ Perl_rxres_save(pTHX_ void **rsp, REGEXP *rx)
     *p++ = PTR2UV(RX_MATCH_COPIED(rx) ? rx->subbeg : Nullch);
     RX_MATCH_COPIED_off(rx);
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     *p++ = PTR2UV(rx->saved_copy);
     rx->saved_copy = Nullsv;
 #endif
@@ -348,7 +348,7 @@ Perl_rxres_restore(pTHX_ void **rsp, REGEXP *rx)
     RX_MATCH_COPIED_set(rx, *p);
     *p++ = 0;
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     if (rx->saved_copy)
 	SvREFCNT_dec (rx->saved_copy);
     rx->saved_copy = INT2PTR(SV*,*p);
@@ -372,7 +372,7 @@ Perl_rxres_free(pTHX_ void **rsp)
 
     if (p) {
 	Safefree(INT2PTR(char*,*p));
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	if (p[1]) {
 	    SvREFCNT_dec (INT2PTR(SV*,p[1]));
 	}
diff --git a/pp_hot.c b/pp_hot.c
index 157281863f..ecae4655e2 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1389,7 +1389,7 @@ yup:					/* Confirmed by INTUIT */
     }
     if (PL_sawampersand) {
 	I32 off;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	if (SvIsCOW(TARG) || (SvFLAGS(TARG) & CAN_COW_MASK) == CAN_COW_FLAGS) {
 	    if (DEBUG_C_TEST) {
 		PerlIO_printf(Perl_debug_log,
@@ -1405,7 +1405,7 @@ yup:					/* Confirmed by INTUIT */
 	{
 
 	    rx->subbeg = savepvn(t, strend - t);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    rx->saved_copy = Nullsv;
 #endif
 	}
@@ -1958,7 +1958,7 @@ PP(pp_subst)
     I32 oldsave = PL_savestack_ix;
     STRLEN slen;
     bool doutf8 = FALSE;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     bool is_cow;
 #endif
     SV *nsv = Nullsv;
@@ -1974,7 +1974,7 @@ PP(pp_subst)
 	EXTEND(SP,1);
     }
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     /* Awooga. Awooga. "bool" types that are actually char are dangerous,
        because they make integers such as 256 "false".  */
     is_cow = SvIsCOW(TARG) ? TRUE : FALSE;
@@ -1983,7 +1983,7 @@ PP(pp_subst)
 	sv_force_normal_flags(TARG,0);
 #endif
     if (
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	!is_cow &&
 #endif
 	(SvREADONLY(TARG)
@@ -2067,7 +2067,7 @@ PP(pp_subst)
     
     /* can do inplace substitution? */
     if (c
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	&& !is_cow
 #endif
 	&& (I32)clen <= rx->minlen && (once || !(r_flags & REXEC_COPY_STR))
@@ -2081,7 +2081,7 @@ PP(pp_subst)
 	    LEAVE_SCOPE(oldsave);
 	    RETURN;
 	}
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	if (SvIsCOW(TARG)) {
 	    assert (!force_on_match);
 	    goto have_a_cow;
@@ -2188,7 +2188,7 @@ PP(pp_subst)
 	    s = SvPV_force(TARG, len);
 	    goto force_it;
 	}
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
       have_a_cow:
 #endif
 	rxtainted |= RX_MATCH_TAINTED(rx);
@@ -2232,7 +2232,7 @@ PP(pp_subst)
 	else
 	    sv_catpvn(dstr, s, strend - s);
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	/* The match may make the string COW. If so, brilliant, because that's
 	   just saved us one malloc, copy and free - the regexp has donated
 	   the old buffer, and we malloc an entirely new one, rather than the
diff --git a/proto.h b/proto.h
index c981d7f4bf..ad7d72c20d 100644
--- a/proto.h
+++ b/proto.h
@@ -1809,7 +1809,7 @@ PERL_CALLCONV char *	Perl_custom_op_desc(pTHX_ const OP* op)
 			__attribute__nonnull__(pTHX_1);
 
 
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 PERL_CALLCONV int	Perl_sv_release_IVX(pTHX_ SV *sv);
 #endif
 
@@ -2398,7 +2398,7 @@ STATIC bool	S_utf8_mg_pos_init(pTHX_ SV *sv, MAGIC **mgp, STRLEN **cachep, I32 i
 			__attribute__nonnull__(pTHX_6)
 			__attribute__nonnull__(pTHX_7);
 
-#if defined(PERL_COPY_ON_WRITE)
+#if defined(PERL_OLD_COPY_ON_WRITE)
 STATIC void	S_sv_release_COW(pTHX_ SV *sv, const char *pvx, STRLEN cur, STRLEN len, U32 hash, SV *after);
 #endif
 #endif
@@ -2520,7 +2520,7 @@ PERL_CALLCONV char*	Perl_my_atof2(pTHX_ const char *s, NV* value)
 			__attribute__nonnull__(pTHX_2);
 
 PERL_CALLCONV int	Perl_my_socketpair(int family, int type, int protocol, int fd[2]);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 PERL_CALLCONV SV*	Perl_sv_setsv_cow(pTHX_ SV* dsv, SV* ssv);
 #endif
 
diff --git a/regcomp.c b/regcomp.c
index 638a87f3e5..b35dcf94f8 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -2900,7 +2900,7 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     r->prelen = xend - exp;
     r->precomp = savepvn(RExC_precomp, r->prelen);
     r->subbeg = NULL;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     r->saved_copy = Nullsv;
 #endif
     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
@@ -6156,7 +6156,7 @@ Perl_pregfree(pTHX_ struct regexp *r)
     if (r->offsets)             /* 20010421 MJD */
 	Safefree(r->offsets);
     RX_MATCH_COPY_FREE(r);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     if (r->saved_copy)
 	SvREFCNT_dec(r->saved_copy);
 #endif
@@ -6338,7 +6338,7 @@ Perl_save_re_context(pTHX)
     PL_reg_oldsaved = Nullch;
     SAVEI32(PL_reg_oldsavedlen);	/* old length of saved substr during match */
     PL_reg_oldsavedlen = 0;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     SAVESPTR(PL_nrs);
     PL_nrs = Nullsv;
 #endif
diff --git a/regexec.c b/regexec.c
index e740690606..8b305e8af9 100644
--- a/regexec.c
+++ b/regexec.c
@@ -2061,7 +2061,7 @@ got_it:
 	RX_MATCH_COPY_FREE(prog);
 	if (flags & REXEC_COPY_STR) {
 	    I32 i = PL_regeol - startpos + (stringarg - strbeg);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    if ((SvIsCOW(sv)
 		 || (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS)) {
 		if (DEBUG_C_TEST) {
@@ -2169,7 +2169,7 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
 		$` inside (?{}) could fail... */
 	    PL_reg_oldsaved = prog->subbeg;
 	    PL_reg_oldsavedlen = prog->sublen;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    PL_nrs = prog->saved_copy;
 #endif
 	    RX_MATCH_COPIED_off(prog);
@@ -4908,7 +4908,7 @@ restore_pos(pTHX_ void *arg)
 	if (PL_reg_oldsaved) {
 	    PL_reg_re->subbeg = PL_reg_oldsaved;
 	    PL_reg_re->sublen = PL_reg_oldsavedlen;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	    PL_reg_re->saved_copy = PL_nrs;
 #endif
 	    RX_MATCH_COPIED_on(PL_reg_re);
diff --git a/regexp.h b/regexp.h
index f5d2424086..3ff959c120 100644
--- a/regexp.h
+++ b/regexp.h
@@ -37,7 +37,7 @@ typedef struct regexp {
         struct reg_data *data;	/* Additional data. */
 	char *subbeg;		/* saved or original string 
 				   so \digit works forever. */
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
         SV *saved_copy;         /* If non-NULL, SV which is COW from original */
 #endif
         U32 *offsets;           /* offset annotations 20001228 MJD */
@@ -104,7 +104,7 @@ typedef struct regexp {
 					 ? RX_MATCH_COPIED_on(prog) \
 					 : RX_MATCH_COPIED_off(prog))
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 #define RX_MATCH_COPY_FREE(rx) \
 	STMT_START {if (rx->saved_copy) { \
 	    SV_CHECK_THINKFIRST_COW_DROP(rx->saved_copy); \
diff --git a/sv.c b/sv.c
index de411a597b..5062520ae9 100644
--- a/sv.c
+++ b/sv.c
@@ -47,7 +47,7 @@
 #define ASSERT_UTF8_CACHE(cache) NOOP
 #endif
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 #define SV_COW_NEXT_SV(sv)	INT2PTR(SV *,SvUVX(sv))
 #define SV_COW_NEXT_SV_SET(current,next)	SvUV_set(current, PTR2UV(next))
 /* This is a pessimistic view. Scalar must be purely a read-write PV to copy-
@@ -4193,7 +4193,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
 	}
 	break;
     case SVt_PVFM:
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	if ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS) {
 	    if (dtype < SVt_PVIV)
 		sv_upgrade(dstr, SVt_PVIV);
@@ -4464,7 +4464,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
 	if (
 	    /* We're not already COW  */
             ((sflags & (SVf_FAKE | SVf_READONLY)) != (SVf_FAKE | SVf_READONLY)
-#ifndef PERL_COPY_ON_WRITE
+#ifndef PERL_OLD_COPY_ON_WRITE
 	     /* or we are, but dstr isn't a suitable target.  */
 	     || (SvFLAGS(dstr) & CAN_COW_MASK) != CAN_COW_FLAGS
 #endif
@@ -4479,7 +4479,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
                  SvLEN(sstr) 	&&	  /* and really is a string */
 	    			/* and won't be needed again, potentially */
 	      !(PL_op && PL_op->op_type == OP_AASSIGN))
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
             && !((sflags & CAN_COW_MASK) == CAN_COW_FLAGS
 		 && (SvFLAGS(dstr) & CAN_COW_MASK) == CAN_COW_FLAGS
                  && SvTYPE(sstr) >= SVt_PVIV)
@@ -4493,7 +4493,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
             SvCUR_set(dstr, len);
             *SvEND(dstr) = '\0';
         } else {
-            /* If PERL_COPY_ON_WRITE is not defined, then isSwipe will always
+            /* If PERL_OLD_COPY_ON_WRITE is not defined, then isSwipe will always
                be true in here.  */
             /* Either it's a shared hash key, or it's suitable for
                copy-on-write or we can swipe the string.  */
@@ -4502,7 +4502,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
                 sv_dump(sstr);
                 sv_dump(dstr);
             }
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
             if (!isSwipe) {
                 /* I believe I should acquire a global SV mutex if
                    it's a COW sv (not a shared hash key) to stop
@@ -4534,7 +4534,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
                 /* making another shared SV.  */
                 STRLEN cur = SvCUR(sstr);
                 STRLEN len = SvLEN(sstr);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
                 if (len) {
 		    assert (SvTYPE(dstr) >= SVt_PVIV);
                     /* SvIsCOW_normal */
@@ -4655,7 +4655,7 @@ Perl_sv_setsv_mg(pTHX_ SV *dstr, register SV *sstr)
     SvSETMAGIC(dstr);
 }
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 SV *
 Perl_sv_setsv_cow(pTHX_ SV *dstr, SV *sstr)
 {
@@ -4874,7 +4874,7 @@ Perl_sv_usepvn_mg(pTHX_ register SV *sv, register char *ptr, register STRLEN len
     SvSETMAGIC(sv);
 }
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 /* Need to do this *after* making the SV normal, as we need the buffer
    pointer to remain valid until after we've copied it.  If we let go too early,
    another thread could invalidate it by unsharing last of the same hash key
@@ -4941,7 +4941,7 @@ with flags set to 0.
 void
 Perl_sv_force_normal_flags(pTHX_ register SV *sv, U32 flags)
 {
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     if (SvREADONLY(sv)) {
         /* At this point I believe I should acquire a global SV mutex.  */
 	if (SvFAKE(sv)) {
@@ -5381,7 +5381,7 @@ Perl_sv_magic(pTHX_ register SV *sv, SV *obj, int how, const char *name, I32 nam
     const MGVTBL *vtable = 0;
     MAGIC* mg;
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     if (SvIsCOW(sv))
         sv_force_normal_flags(sv, 0);
 #endif
@@ -5809,7 +5809,7 @@ Perl_sv_replace(pTHX_ register SV *sv, register SV *nsv)
     }
 	
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     if (SvIsCOW_normal(nsv)) {
 	/* We need to follow the pointers around the loop to make the
 	   previous SV point to sv, rather than nsv.  */
@@ -5979,7 +5979,7 @@ Perl_sv_clear(pTHX_ register SV *sv)
 	    else
 	        SvREFCNT_dec(SvRV(sv));
 	}
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 	else if (SvPVX_const(sv)) {
             if (SvIsCOW(sv)) {
                 /* I believe I need to grab the global SV mutex here and
@@ -10321,7 +10321,7 @@ Perl_re_dup(pTHX_ REGEXP *r, CLONE_PARAMS *param)
 	ret->subbeg  = SAVEPVN(r->subbeg, r->sublen);
     else
 	ret->subbeg = Nullch;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     ret->saved_copy = Nullsv;
 #endif
 
@@ -12389,7 +12389,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_reg_curpm	= (PMOP*)NULL;
     PL_reg_oldsaved	= Nullch;
     PL_reg_oldsavedlen	= 0;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
     PL_nrs		= Nullsv;
 #endif
     PL_reg_maxiter	= 0;
diff --git a/sv.h b/sv.h
index 6c79c1972b..d1d719d899 100644
--- a/sv.h
+++ b/sv.h
@@ -1359,13 +1359,13 @@ Like C<sv_catsv> but doesn't process magic.
 #define SV_CHECK_THINKFIRST_COW_DROP(sv) if (SvTHINKFIRST(sv)) \
 				    sv_force_normal_flags(sv, SV_COW_DROP_PV)
 
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
 #  define SvRELEASE_IVX(sv)   ((void)((SvFLAGS(sv) & (SVf_OOK|SVf_READONLY|SVf_FAKE)) \
 				&& Perl_sv_release_IVX(aTHX_ sv)))
 #  define SvIsCOW_normal(sv)	(SvIsCOW(sv) && SvLEN(sv))
 #else
 #  define SvRELEASE_IVX(sv)   SvOOK_off(sv)
-#endif /* PERL_COPY_ON_WRITE */
+#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| \