X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=XS.xs;h=1ad66143340ea15f7e9c8dc1813339fb2a8acb53;hb=68fe9f2928a5a423e6d31eaf4b2bf0c17c9bfb27;hp=db14fd525ecfbec52547bb2c68061a18a3c360ed;hpb=6ed110b7fc5eb75d2ec95703dbbe7cba0f03b6dc;p=gitmo%2FClass-C3-XS.git

diff --git a/XS.xs b/XS.xs
index db14fd5..1ad6614 100644
--- a/XS.xs
+++ b/XS.xs
@@ -50,6 +50,10 @@
 
 /* *********** end ppport.h stuff */
 
+#ifndef SVfARG
+#  define SVfARG(p)                      ((void*)(p))
+#endif
+
 /* Most of this code is backported from the bleadperl patch's
    mro.c, and then modified to work with Class::C3's
    internals.
@@ -231,13 +235,22 @@ __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
             /* If we had candidates, but nobody won, then the @ISA
                hierarchy is not C3-incompatible */
             if(!winner) {
+                SV *errmsg;
+                I32 i;
                 /* we have to do some cleanup before we croak */
 
+                errmsg = newSVpvf("Inconsistent hierarchy during C3 merge of class '%s':\n\t"
+                                  "current merge results [\n", stashname);
+                for (i = 0; i <= av_len(retval); i++) {
+                    SV **elem = av_fetch(retval, i, 0);
+                    sv_catpvf(errmsg, "\t\t%"SVf",\n", SVfARG(*elem));
+                }
+                sv_catpvf(errmsg, "\t]\n\tmerging failed on '%"SVf"'", SVfARG(cand));
+
                 SvREFCNT_dec(retval);
                 Safefree(heads);
 
-                Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': "
-                    "merging failed on parent '%s'", stashname, SvPV_nolen(cand));
+                croak("%"SVf, SVfARG(errmsg));
             }
         }
     }