[Bug ipa/69589] [6 Regression] ICE in initialize_node_lattices, at ipa-cp.c:971

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69589

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org

--- Comment #10 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Hello from China and thanks for the analysis,
(gdb) p node->debug()
_ZN2JS3ubi20PreComputedEdgeRangeD2Ev/73127 (__base_dtor ) @0x7ffff5666e60
  Type: function definition analyzed
  Visibility: prevailing_def_ironly artificial
  Aux: @0x2a89e30  References: 
  Referring: 
  Read from file: Unified_cpp_js_src35.o
  Availability: local
  First run: 0
  Function flags: local merged_comdat unlikely_executed
  Called by: 
  Calls:
the node is local and not externally visible....

          /* If any symbol in a comdat group is reachable, force
             all externally visible symbols in the same comdat
             group to be reachable as well.  Comdat-local symbols
             can be discarded if all uses were inlined.  */
          if (node->same_comdat_group)
            {
              symtab_node *next;
              for (next = node->same_comdat_group;
                   next != node;
                   next = next->same_comdat_group)
                if (!next->comdat_local_p ()
                    && !reachable.add (next))
                  enqueue_node (next, &first, &reachable);
            }

This loop explicitly skips comdat_local_p. In general local flag should imply
comdat_local_p on comdat symbols. It should be possible to add gcc_assert that
the node is never local when enqueue_node is called here.

In your second dump the node is still externally visible and !local, so it may
be necessary to lookup when it becomes local and why it is not removed
afterwards?  I think only whole_program_visibility pass brings nodes local, so
you may want to breakpoint in the remove_unreachable_nodes call that is done
just before ipa-cp.

Honza