Move the meta->isa code from UNIVERSAL::isa to mro_get_linear_isa

This is so that it can be used for PL_isarev bookkeeping as well.

This will have no effect on the speed of DFS classes. C3 classes on
which ->isa is never called will have a slight slowdown. (We could
always add an API for setting meta->isa if we want to avoid that.)

1 files changed, 1 insertions, 23 deletions

diff --git a/universal.c b/universal.c
index 37c332f140..c6dd7fc1d5 100644
--- a/universal.c
+++ b/universal.c
@@ -42,29 +42,7 @@ S_get_isa_hash(pTHX_ HV *const stash)
     PERL_ARGS_ASSERT_GET_ISA_HASH;
 
     if (!meta->isa) {
-	AV *const isa = mro_get_linear_isa(stash);
-	if (!meta->isa) {
-	    HV *const isa_hash = newHV();
-	    /* Linearisation didn't build it for us, so do it here.  */
-	    SV *const *svp = AvARRAY(isa);
-	    SV *const *const svp_end = svp + AvFILLp(isa) + 1;
-	    const HEK *canon_name = HvENAME_HEK(stash);
-	    if (!canon_name) canon_name = HvNAME_HEK(stash);
-
-	    while (svp < svp_end) {
-		(void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0);
-	    }
-
-	    (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name),
-			     HEK_LEN(canon_name), HEK_FLAGS(canon_name),
-			     HV_FETCH_ISSTORE, &PL_sv_undef,
-			     HEK_HASH(canon_name));
-	    (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0);
-
-	    SvREADONLY_on(isa_hash);
-
-	    meta->isa = isa_hash;
-	}
+	(void)mro_get_linear_isa(stash);
     }
     return meta->isa;
 }