add GvCV_set() and GvGP_set() macros.

and make GvCV() and GvGP() rvalue-only.

This it to allow a future commit to eliminate some backref magic between
GV and CVs, which will require complete control over assignment to the
gp_cv slot.

6 files changed, 36 insertions, 28 deletions

diff --git a/gv.c b/gv.c
index 9b57364be5..56f7df6ae0 100644
--- a/gv.c
+++ b/gv.c
@@ -298,7 +298,7 @@ Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
     SvIOK_off(gv);
     isGV_with_GP_on(gv);
 
-    GvGP(gv) = Perl_newGP(aTHX_ gv);
+    GvGP_set(gv, Perl_newGP(aTHX_ gv));
     GvSTASH(gv) = stash;
     if (stash)
 	Perl_sv_add_backref(aTHX_ MUTABLE_SV(stash), MUTABLE_SV(gv));
@@ -319,7 +319,7 @@ Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
 	    cv = newCONSTSUB(stash, (name0 ? name0 : name), has_constant);
 	    /* In case op.c:S_process_special_blocks stole it: */
 	    if (!GvCV(gv))
-		GvCV(gv) = (CV *)SvREFCNT_inc_simple_NN(cv);
+		GvCV_set(gv, (CV *)SvREFCNT_inc_simple_NN(cv));
 	    assert(GvCV(gv) == cv); /* newCONSTSUB should have set this */
 	    if (name0)
 		Safefree(name0);
@@ -331,7 +331,7 @@ Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
 	} else {
 	    (void) start_subparse(0,0);	/* Create empty CV in compcv. */
 	    cv = PL_compcv;
-	    GvCV(gv) = cv;
+	    GvCV_set(gv,cv);
 	}
 	LEAVE;
 
@@ -456,7 +456,8 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
             else {
                 /* stale cache entry, junk it and move on */
 	        SvREFCNT_dec(cand_cv);
-	        GvCV(topgv) = cand_cv = NULL;
+	        GvCV_set(topgv, NULL);
+		cand_cv = NULL;
 	        GvCVGEN(topgv) = 0;
             }
         }
@@ -506,7 +507,7 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
             if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
                   if ((old_cv = GvCV(topgv))) SvREFCNT_dec(old_cv);
                   SvREFCNT_inc_simple_void_NN(cand_cv);
-                  GvCV(topgv) = cand_cv;
+                  GvCV_set(topgv, cand_cv);
                   GvCVGEN(topgv) = topgen_cmp;
             }
 	    return candidate;
@@ -521,7 +522,7 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
             if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
                   if ((old_cv = GvCV(topgv))) SvREFCNT_dec(old_cv);
                   SvREFCNT_inc_simple_void_NN(cand_cv);
-                  GvCV(topgv) = cand_cv;
+                  GvCV_set(topgv, cand_cv);
                   GvCVGEN(topgv) = topgen_cmp;
             }
             return candidate;
@@ -1705,7 +1706,7 @@ Perl_gp_free(pTHX_ GV *gv)
     if (--gp->gp_refcnt > 0) {
 	if (gp->gp_egv == gv)
 	    gp->gp_egv = 0;
-	GvGP(gv) = 0;
+	GvGP_set(gv, NULL);
         return;
     }
 
@@ -1727,7 +1728,7 @@ Perl_gp_free(pTHX_ GV *gv)
     SvREFCNT_dec(gp->gp_form);
 
     Safefree(gp);
-    GvGP(gv) = 0;
+    GvGP_set(gv, NULL);
 }
 
 int
diff --git a/gv.h b/gv.h
index ecea60dcb0..ab5c788987 100644
--- a/gv.h
+++ b/gv.h
@@ -27,10 +27,15 @@ struct gp {
 
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN) && !defined(__INTEL_COMPILER)
 #  define GvGP(gv)							\
-	(*({GV *const _gvgp = (GV *) (gv);				\
+	(0+(*({GV *const _gvgp = (GV *) (gv);				\
 	    assert(SvTYPE(_gvgp) == SVt_PVGV || SvTYPE(_gvgp) == SVt_PVLV); \
 	    assert(isGV_with_GP(_gvgp));				\
-	    &((_gvgp)->sv_u.svu_gp);}))
+	    &((_gvgp)->sv_u.svu_gp);})))
+#  define GvGP_set(gv,gp)						\
+	{GV *const _gvgp = (GV *) (gv);				\
+	    assert(SvTYPE(_gvgp) == SVt_PVGV || SvTYPE(_gvgp) == SVt_PVLV); \
+	    assert(isGV_with_GP(_gvgp));				\
+	    (_gvgp)->sv_u.svu_gp = (gp); }
 #  define GvFLAGS(gv)							\
 	(*({GV *const _gvflags = (GV *) (gv);				\
 	    assert(SvTYPE(_gvflags) == SVt_PVGV || SvTYPE(_gvflags) == SVt_PVLV); \
@@ -52,7 +57,8 @@ struct gp {
 #  define GvNAME_get(gv)	({ assert(GvNAME_HEK(gv)); (char *)HEK_KEY(GvNAME_HEK(gv)); })
 #  define GvNAMELEN_get(gv)	({ assert(GvNAME_HEK(gv)); HEK_LEN(GvNAME_HEK(gv)); })
 #else
-#  define GvGP(gv)	((gv)->sv_u.svu_gp)
+#  define GvGP(gv)	(0+(gv)->sv_u.svu_gp)
+#  define GvGP_set(gv,gp)	((gv)->sv_u.svu_gp = (gp))
 #  define GvFLAGS(gv)	(GvXPVGV(gv)->xpv_cur)
 #  define GvSTASH(gv)	(GvXPVGV(gv)->xnv_u.xgv_stash)
 #  define GvNAME_HEK(gv)	(GvXPVGV(gv)->xiv_u.xivu_namehek)
@@ -114,7 +120,8 @@ Return the SV from the GV.
 			 GvGP(gv)->gp_hv : \
 			 GvGP(gv_HVadd(gv))->gp_hv)
 
-#define GvCV(gv)	(GvGP(gv)->gp_cv)
+#define GvCV(gv)	(0+GvGP(gv)->gp_cv)
+#define GvCV_set(gv,cv)	(GvGP(gv)->gp_cv = (cv))
 #define GvCVGEN(gv)	(GvGP(gv)->gp_cvgen)
 #define GvCVu(gv)	(GvGP(gv)->gp_cvgen ? NULL : GvGP(gv)->gp_cv)
 
diff --git a/op.c b/op.c
index bb1d9a8bb4..ad94f6ef8d 100644
--- a/op.c
+++ b/op.c
@@ -6244,7 +6244,7 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
 	    CvISXSUB_on(cv);
 	}
 	else {
-	    GvCV(gv) = NULL;
+	    GvCV_set(gv, NULL);
 	    cv = newCONSTSUB(NULL, name, const_sv);
 	}
         mro_method_changed_in( /* sub Foo::Bar () { 123 } */
@@ -6309,7 +6309,7 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
     else {
 	cv = PL_compcv;
 	if (name) {
-	    GvCV(gv) = cv;
+	    GvCV_set(gv, cv);
 	    if (PL_madskills) {
 		if (strEQ(name, "import")) {
 		    PL_formfeed = MUTABLE_SV(cv);
@@ -6455,7 +6455,7 @@ S_process_special_blocks(pTHX_ const char *const fullname, GV *const gv,
 
 	    DEBUG_x( dump_sub(gv) );
 	    Perl_av_create_and_push(aTHX_ &PL_beginav, MUTABLE_SV(cv));
-	    GvCV(gv) = 0;		/* cv has been hijacked */
+	    GvCV_set(gv,0);		/* cv has been hijacked */
 	    call_list(oldscope, PL_beginav);
 
 	    PL_curcop = &PL_compiling;
@@ -6499,7 +6499,7 @@ S_process_special_blocks(pTHX_ const char *const fullname, GV *const gv,
 	} else
 	    return;
 	DEBUG_x( dump_sub(gv) );
-	GvCV(gv) = 0;		/* cv has been hijacked */
+	GvCV_set(gv,0);		/* cv has been hijacked */
     }
 }
 
@@ -6677,7 +6677,7 @@ Perl_newXS(pTHX_ const char *name, XSUBADDR_t subaddr, const char *filename)
     else {
 	cv = MUTABLE_CV(newSV_type(SVt_PVCV));
 	if (name) {
-	    GvCV(gv) = cv;
+	    GvCV_set(gv,cv);
 	    GvCVGEN(gv) = 0;
             mro_method_changed_in(GvSTASH(gv)); /* newXS */
 	}
@@ -7653,7 +7653,7 @@ Perl_ck_glob(pTHX_ OP *o)
 		newSVpvs("File::Glob"), NULL, NULL, NULL);
 	if((glob_gv = gv_fetchpvs("File::Glob::csh_glob", 0, SVt_PVCV))) {
 	    gv = gv_fetchpvs("CORE::GLOBAL::glob", 0, SVt_PVCV);
-	    GvCV(gv) = GvCV(glob_gv);
+	    GvCV_set(gv, GvCV(glob_gv));
 	    SvREFCNT_inc_void(MUTABLE_SV(GvCV(gv)));
 	    GvIMPORTED_CV_on(gv);
 	}
diff --git a/pp.c b/pp.c
index edd40841b7..0a955bb392 100644
--- a/pp.c
+++ b/pp.c
@@ -1045,7 +1045,7 @@ PP(pp_undef)
 
 	    gp_free(MUTABLE_GV(sv));
 	    Newxz(gp, 1, GP);
-	    GvGP(sv) = gp_ref(gp);
+	    GvGP_set(sv, gp_ref(gp));
 	    GvSV(sv) = newSV(0);
 	    GvLINE(sv) = CopLINE(PL_curcop);
 	    GvEGV(sv) = MUTABLE_GV(sv);
diff --git a/scope.c b/scope.c
index fb93db0c8d..e0ba9a366a 100644
--- a/scope.c
+++ b/scope.c
@@ -298,7 +298,7 @@ Perl_save_gp(pTHX_ GV *gv, I32 empty)
 	    gp->gp_sv = newSV(0);
 	}
 #endif
-	GvGP(gv) = gp;
+	GvGP_set(gv,gp);
     }
     else {
 	gp_ref(GvGP(gv));
@@ -848,7 +848,7 @@ Perl_leave_scope(pTHX_ I32 base)
 	    ptr = SSPOPPTR;
 	    gv = MUTABLE_GV(SSPOPPTR);
 	    gp_free(gv);
-	    GvGP(gv) = (GP*)ptr;
+	    GvGP_set(gv, (GP*)ptr);
             /* putting a method back into circulation ("local")*/
 	    if (GvCVu(gv) && (hv=GvSTASH(gv)) && HvENAME_get(hv))
                 mro_method_changed_in(hv);
diff --git a/sv.c b/sv.c
index def677bb29..1c5a0f14b7 100644
--- a/sv.c
+++ b/sv.c
@@ -522,7 +522,7 @@ do_clean_named_objs(pTHX_ SV *const sv)
     if ( ((obj = MUTABLE_SV(GvCV(sv)) )) && SvOBJECT(obj)) {
 	DEBUG_D((PerlIO_printf(Perl_debug_log,
 		"Cleaning named glob CV object:\n "), sv_dump(obj)));
-	GvCV(sv) = NULL;
+	GvCV_set(sv, NULL);
 	SvREFCNT_dec(obj);
     }
     SvREFCNT_dec(sv); /* undo the inc above */
@@ -3623,7 +3623,7 @@ S_glob_assign_glob(pTHX_ SV *const dstr, SV *const sstr, const int dtype)
         /* If source has method cache entry, clear it */
         if(GvCVGEN(sstr)) {
             SvREFCNT_dec(GvCV(sstr));
-            GvCV(sstr) = NULL;
+            GvCV_set(sstr, NULL);
             GvCVGEN(sstr) = 0;
         }
         /* If source has a real method, then a method is
@@ -3676,7 +3676,7 @@ S_glob_assign_glob(pTHX_ SV *const dstr, SV *const sstr, const int dtype)
     (void)SvOK_off(dstr);
     isGV_with_GP_on(dstr);
     GvINTRO_off(dstr);		/* one-shot flag */
-    GvGP(dstr) = gp_ref(GvGP(sstr));
+    GvGP_set(dstr, gp_ref(GvGP(sstr)));
     if (SvTAINTED(sstr))
 	SvTAINT(dstr);
     if (GvIMPORTED(dstr) != GVf_IMPORTED
@@ -3731,7 +3731,7 @@ S_glob_assign_ref(pTHX_ SV *const dstr, SV *const sstr)
     GvMULTI_on(dstr);
     switch (stype) {
     case SVt_PVCV:
-	location = (SV **) &GvCV(dstr);
+	location = (SV **) &(GvGP(dstr)->gp_cv); /* XXX bypassing GvCV_set */
 	import_flag = GVf_IMPORTED_CV;
 	goto common;
     case SVt_PVHV:
@@ -3757,7 +3757,7 @@ S_glob_assign_ref(pTHX_ SV *const dstr, SV *const sstr)
 		/*if (GvCVGEN(dstr) && (GvCV(dstr) != (const CV *)sref || GvCVGEN(dstr))) {*/
 		if (GvCVGEN(dstr)) {
 		    SvREFCNT_dec(GvCV(dstr));
-		    GvCV(dstr) = NULL;
+		    GvCV_set(dstr, NULL);
 		    GvCVGEN(dstr) = 0; /* Switch off cacheness. */
 		}
 	    }
@@ -4129,7 +4129,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV* sstr, const I32 flags)
 
 		if (GvGP(dstr))
 		    gp_free(MUTABLE_GV(dstr));
-		GvGP(dstr) = gp_ref(GvGP(gv));
+		GvGP_set(dstr, gp_ref(GvGP(gv)));
 
 		if (reset_isa) {
 		    HV * const stash = GvHV(dstr);
@@ -11847,7 +11847,7 @@ S_sv_dup_common(pTHX_ const SV *const sstr, CLONE_PARAMS *const param)
 		    GvSTASH(dstr) = hv_dup(GvSTASH(dstr), param);
 		    if (param->flags & CLONEf_JOIN_IN)
 			Perl_sv_add_backref(aTHX_ MUTABLE_SV(GvSTASH(dstr)), dstr);
-		    GvGP(dstr)	= gp_dup(GvGP(sstr), param);
+		    GvGP_set(dstr, gp_dup(GvGP(sstr), param));
 		    (void)GpREFCNT_inc(GvGP(dstr));
 		}
 		break;