[Bug ada/53008] abort in _ITM_getTMCloneSafe

["patrick.marlier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53008

--- Comment #8 from Patrick Marlier <patrick.marlier at gmail dot com> 2012-05-22 15:58:53 UTC ---
Aldy,

Actually the problem is different that my first thought and it is a real bug.
The problem is well described into the 'testcase for gcc testsuite'.
In the testcase, you have a static function foo which is transaction_safe so a
clone is created. This function foo is assigned to a transaction_safe function
pointer and this function pointer is used in a transaction. However this
tm-clone foo is never referenced so it is removed by
ipa.c:cgraph_remove_unreachable_nodes().
One way to fix the problem is force the output of the clone as following:

Index: trans-mem.c
===================================================================
--- trans-mem.c (revision 187371)
+++ trans-mem.c (working copy)
@@ -4330,7 +4330,8 @@ ipa_tm_create_version_alias (struct cgraph_node *n

   record_tm_clone_pair (old_decl, new_decl);

-  if (info->old_node->symbol.force_output)
+  if (info->old_node->symbol.force_output
+      || ipa_ref_list_first_referring (&info->old_node->symbol.ref_list))
     ipa_tm_mark_force_output_node (new_node);
   return false;
 }
@@ -4383,7 +4384,8 @@ ipa_tm_create_version (struct cgraph_node *old_nod
   record_tm_clone_pair (old_decl, new_decl);

   cgraph_call_function_insertion_hooks (new_node);
-  if (old_node->symbol.force_output)
+  if (old_node->symbol.force_output
+      || ipa_ref_list_first_referring (&old_node->symbol.ref_list))
     ipa_tm_mark_force_output_node (new_node);

   /* Do the same thing, but for any aliases of the original node.  */

However, I am not sure it is really the way to go. Probably we should add the
references from the orginal function to the tm-clone?

Thanks,
Patrick