On Thu, May 25, 2017 at 9:03 AM, Nathan Sidwell <nat...@acm.org> wrote: > Anyway, this implementation introduces LOOKUP_SEEN_P and LOOKUP_FOUND_P to > directly mark the DECL node. Hence determination is now O(1) rather than > O(N^2). We still have a vector to recall which decls we need to unmark at > the end of the lookup. We need two markers on a class, because depending on > how we found it we may need to search additional things about it. (These two > maker bits will be used in later changes too.) > > One quirk is that ADL can be recursive. ADL can cause template > instantiation, which can in turn cause a different ADL to happen. The new > testcase is an example of this. So, we need to detect this and undo/redo > the outer DECL marking during the inner ADL. Thus implementing a simple > chain of ADLs and using their record of which decls got marked to undo/redo. > The fiddly bit there is recording whether LOOKUP_FOUND_P was set or not > (LOOKUP_SEEN_P will be). To record that I simply push those DECLS with > lookup_found_p set onto the stack. They'll thus appear twice, and we can > infer from the second sighting that it had FOUND_P set (and pop the stack). > The recursion is a rare event, so we optimize the non-recursive case.
Sounds like it would make sense to use a hash_set rather than flags on the decls. Jason
