[Bug c++/67166] New: Inconsistency between static data members and static functions when using multiple inheritance

[anders.granlund.0 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67166

            Bug ID: 67166
           Summary: Inconsistency between static data members and static
                    functions when using multiple inheritance
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anders.granlund.0 at gmail dot com
  Target Milestone: ---

Consider the following two programs:

  struct A { static const int x = 0; };
  struct B : A { using A::x; };
  struct C : B, A {};
  int main() { C::x; }


  struct A { static void x() {} };
  struct B : A { using A::x; };
  struct C : B, A {};
  int main() { C::x; }

Compile them with the following command line:

  g++ prog.cc -std=c++14 -pedantic-errors

GCC inconsistently accepts the first program, but rejects the second program
with the following error:

  prog.cc: In function 'int main()':
  prog.cc:4:16: error: reference to 'x' is ambiguous
     int main() { C::x; }
                ^
  prog.cc:1:26: note: candidates are: static void A::x()
     struct A { static void x() {} };
                          ^
  prog.cc:1:26: note:                 static void A::x()

I think GCC should consistently accept both programs just like clang does.

This is because we have no ambiguity here in the name-lookup. There is only one
entity with name x, the static member of A.

I have tried this with gcc HEAD 6.0.0 20150808 here:

http://melpon.org/wandbox/permlink/mbr1XEKQp7bF71iS
http://melpon.org/wandbox/permlink/E5iKa6GfLG2q1m0o