[Bug c++/123235] New: [modules] ADL search for decl-reachable entities doesn't complete types

[nshead at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123235

            Bug ID: 123235
           Summary: [modules] ADL search for decl-reachable entities
                    doesn't complete types
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nshead at gcc dot gnu.org
            Blocks: 103524
  Target Milestone: ---

Consider:

// a.cpp
module;
namespace C {
  struct G {};
  void qux(int, void*);
}
template <typename T> struct H : C::G {};
export module M;
template <typename T> void foo(T t) {
  H<int>* h;
  qux(t, h);
}

// b.cpp
module M;
void test() {
  foo(0);
}

This should find C::qux as a decl-reachable entity by
https://eel.is/c++draft/module.global.frag#2.3 since ADL should consider the
associated entities of base class H<int>::G.  Currently we do not however and
qux is discarded.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103524
[Bug 103524] [meta-bug] modules issue