> On Thu, 20 Mar 2014, Martin Jambor wrote: > > > Hi, > > > > On Thu, Mar 20, 2014 at 07:40:56PM +0100, Jakub Jelinek wrote: > > > On Thu, Mar 20, 2014 at 05:07:32PM +0100, Martin Jambor wrote: > > > > in the PR, verifier claims an edge is pointing to a wrong declaration > > > > even though it has successfully verified the edge multiple times > > > > before. The reason is that symtab_remove_unreachable_nodes decides to > > > > "remove the body" of a node and also clear any information that it is > > > > an alias of another in the process (more detailed analysis in comment > > > > #9 of the bug). > > > > > > > > In bugzilla Honza wrote that "silencing the verifier" is the way to > > > > go. Either we can dedicate a new flag in each cgraph_node or > > > > symtab_node just for the purpose of verification or do something more > > > > hackish like the patch below which re-uses the former_clone_of field > > > > for this purpose. Since clones are always private nodes, they should > > > > always either survive removal of unreachable nodes or be completely > > > > killed by it and should never enter the in_border zombie state. > > > > Therefore their former_clone_of must always be NULL. So I added a new > > > > special value, error_mark_node, to mark this zombie state and taught > > > > the verifier to be happy with such nodes. > > > > > > > > Bootstrapped and tested on x86_64-linux. What do you think? > > > > > > Don't we have like 22 spare bits in cgraph_node and 20 spare bits in > > > symtab_node? I'd find it clearer if you just used a new flag to mark the > > > zombie nodes. Though, I'll let Richard or Honza to decide, don't feel > > > strongly about it. > > > > > > > I guess you are right, here is the proper version which is currently > > undergoing bootstrap and testing. > > I agree with Jakub, the following variant is ok.
With the extra bit, you probably will need to LTO pickle it, too. I would go with just clerning the thunk flag: this makes thunk to behave like external function that is safe to do. (I am back in civilization from Alaska camping, will catch up with email early next week) Honza
