On 1/7/21 11:47 AM, Jakub Jelinek wrote:
> In GCC10 cp_walk_subtrees has been changed to walk template arguments.
> As the following testcase, that changed the mangling of some functions.

Argh.

> I believe the previous behavior that find_abi_tags_r doesn't recurse into
> template args has been the correct one, but setting *walk_subtrees = 0
> for the types and handling the types subtree walking manually in
> find_abi_tags_r looks too hard, there are a lot of subtrees and details what
> should and shouldn't be walked, both in tree.c (walk_type_fields there,
> which is static) and in cp_walk_subtrees itself.
> 
> The following patch abuses the fact that *walk_subtrees is an int to
> tell cp_walk_subtrees it shouldn't walk the template args.
> 
> Another option would be to have two separate cp_walk_subtrees-like
> callbacks, one that wouldn't walk into template args and the other
> that would and then would tail call the other one, and
> cp_walk_tree_without_duplicates but call walk_tree_1 directly or use
> some other macro.

I like the idea to use *walk_subtrees to distinguish between walking 
syntactic subtrees and walking type-identity subtrees.  But it should be 
more general; how does this look to you?

Jason