[Bug middle-end/51929] [4.7 Regression] ICE: verify_cgraph_node failed with -O2 -fno-guess-branch-probability -fipa-cp-clone

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51929

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-02-10 10:33:33 UTC ---
This is related to same body aliases.  The verification fails because IPA-CP
decides to cgraph_redirect_edge_callee a call_stmt that calls a same_body_alias
of B<char>::B(A, int) (__comp_ctor) to a clone of not that node (i.e. not the
same_body_alias), but of its ->thunk.alias (i.e. the alias with the actual body
of the ctor, __base_ctor).  I don't find anything wrong on that, so I've tried
to adjust just the verification:
-         function.  This ping-pong has to go, eventaully.  */
+         function.  This ping-pong has to go, eventually.  */
       && (node != cgraph_function_or_thunk_node (e->callee, NULL))
-      && !clone_of_p (node, e->callee))
+      && !clone_of_p (node, e->callee)
+      /* If decl is a same body alias of some other decl, allow e->callee to
be
+         a clone of a clone of that other decl too.  */
+      && (!node->same_body_alias
+          || !clone_of_p (cgraph_get_node (node->thunk.alias), e->callee)))

but unfortunately it just cures one of the two error: edge points to wrong
declaration: errors.