[Bug c++/103499] New: C++20 modules error: invalid use of non-static member function

["oleg at smolsky dot net" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103499

            Bug ID: 103499
           Summary: C++20 modules error: invalid use of non-static member
                    function
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: oleg at smolsky dot net
  Target Milestone: ---

There seems to be a bug when exporting a class hierarchy from a module. Here is
the GCC11 output:

/opt/gcc-11/bin/g++ -std=c++20 -fmodules-ts -c -o main.o main.cpp
main.cpp: In function ‘int main()’:
main.cpp:6:12: error: invalid use of non-static member function ‘virtual
Derived@task::~Derived()’
    6 |     delete p;

$ cat task.cpp
export module task;

#include "b.h"
#include "d.h"

$ cat b.h
#pragma once

export struct Base {
  virtual ~Base() = default;

  void DoStuff();
};

$ cat d.h
#include "b.h"

export struct Derived : Base {
  ~Derived();
};

$ cat main.cpp
import task;

int main() {
    auto p = new Derived;
    p->DoStuff();
    delete p;
}