Andrew Sutton <andrew.n.sut...@gmail.com> writes: | > Internally, we want to always store the canonical form of a decl, not the | > source-level form -- the current g++ AST isn't prepared for that (I wish | > it was, but it isn't.) This allows for simple comparison and other | > semantics processing. | | Agreed. But without some source-level annotations in the tree, I don't | think I can generate the diagnostics that programmer's might otherwise | expect. I'd have to emit the internal representation.
Do you have examples where we don't do or we can't do the obvious thing in terms of diagnostics? The source-level information has to sit above the current AST representation; not mixed with it -- it doesn't expect and isn't prepared for redundancy. | >> I think we want constraints for: | >> | >> * FUNCTION_DECL | >> * TEMPLATE_DECL | >> * TYPE_DECL | >> * TEMPLATE_PARM_DECL | > | > Well, thinking more about it, I believe we want it only for | > * TEMPLATE_DECL | > * TEMPLATE_PARM_DECL. | > | > The FUNCTION_DECL and the TYPE_DECL gets their constraints | > from the abstract instantiation of the associated TEMPLATE_DECL. | | If those constraints are cached, I don't see any other place to put | them except in the template info. Exactly. | On the other hand, it seems like the only place we actually need to | worry about is with non-template member functions. Member function of templates are temploids, so no worry there either. (Internally, they act and are represented like templates.) | I think I can just grab the requirements and arguments and check them | without caching them in the template_info. I think we need to remember them for duplicate_decls or other routines that either check or use ODR-derived properties. | I'll have to experiment. | | We still don't have nodes specific to TEMPLTAE_DECL or | TEMPLATE_PARM_DECL though. A tree with TREE_CODE equal to TEMPLATE_DECL or TEMPLATE_PARM_DECL is just that. What we do is to use all unused- tree slots. Or are you suggesting we have exhausted all available pre-defined slots on such nodes? | It seems like lang_decl_min is the only | place to put this where it will be avilable to both. We have to try hard to avoid growing lang_decl_min. -- Gaby
