This is the mail archive of the
mailing list for the GCC project.
Re: intermodule and comptypes - need some help
Geoff Keating <email@example.com> writes:
> "Zack Weinberg" <firstname.lastname@example.org> writes:
>> A patch I'm working on has, as a side effect, that (in intermodule
>> mode) duplicate_decls may encounter two declarations from different
>> translation units at any time, not just during
> I'd be interested to hear more details about how this happens.
The basic concept is, there's a scope (currently called
external_scope) which holds all TREE_PUBLIC declarations and possibly
some other things. This scope is 'outer' to the file scope, and
persists across translation units. Declarations in there are
invisible until a duplicate declaration of the same thing is
The details are complicated, but I think the result winds up being
more straightforward and less buggy than what we have now. If, that
is, I can make it work.
> I expect that at some point, some type gets created without the right
> context. This would never have mattered before because nothing ever
> looked at the context of types (except in the objc compiler and then
> only in pretty special circumstances).
Thanks for the hint. The predicate I wrote *should* work, then?
> If bootstrapping GCC is getting to be a pain, you might find the
> attached testcase helpful; you can modify it by assigning between x_1
> and x_2 in the different translation units, the assignment is valid in
> -6b but invalid (and requires a diagnostic) in -6a, and yet as written
> the two files are valid ISO C.
This is helpful, thanks, but it doesn't tickle the problem I am
seeing. The problem is like this:
debug.h:127: error: conflicting types for 'dwarf_debug_hooks'
dwarfout.c:1275: error: previous declaration of 'dwarf_debug_hooks'
and, using your hint, I think I've tracked it to BLOCK_SUPERCONTEXT of
the block that's DECL_INITIAL of each translation_unit_decl not
getting initialized properly. The types being handed to my predicate
*seem* to have the right TYPE_CONTEXTs.