From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 573DB385661E; Wed, 28 Jun 2023 08:46:22 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 573DB385661E
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1687941982;
	bh=ZqeacN9rJgxQ9wLpkxw1DR9pg+RicQJcEBOtjUWdYDM=;
	h=From:To:Subject:Date:From;
	b=qkumtPShzvYsGnorPWSeDE5iHdrOtkBLVC6AiblmdXclr+7x+UNI0vI+F7RI3pKWe
	 T2iatgL8Vh9oIcRoUFoHq1UwzxpTsicxQNKtjV+dLLoNW4C9j14GgD6hhANNz7hLv2
	 zTFq+GtJte5qqZ7OxpuSQHEnyu+bQGZIsohnCs7o=
From: "iains at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/110447] New: [modules] unexpected attachment of GMF decls
 to a named module.
Date: Wed, 28 Jun 2023 08:46:20 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: iains at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-110447-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110447

            Bug ID: 110447
           Summary: [modules] unexpected attachment of GMF decls to a
                    named module.
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: iains at gcc dot gnu.org
  Target Milestone: ---

While trying to compare behaviour of GCC and clang ....

=3D=3D=3D=3D

Foo.cpp:

module;

#include <iostream>

export module Foo;

export void
my_hello (const char *str)
{
 std::cout << str << std::endl;
}

=3D=3D=3D=3D
pr61465.cpp:

import Foo; // assume module 'foo' contain the declarations from `<iostream=
>`
#include <iostream>

int main(int argc, char *argv[])
{
    std::cout << "Test\n";
    my_hello ("and we used Foo");
    return 0;
}

=3D=3D=3D=3D

g++ -std=3Dc++20 -fmodules-ts Foo.cpp -c
g++ -std=3Dc++20 -fmodules-ts pr6145-main.cpp Foo.o -o t -flang-info-module=
-cmi

...

In module imported at pr6145-main.cpp:1:1:
Foo: note: reading CMI =E2=80=98gcm.cache/Foo.gcm=E2=80=99

<snip include stack traceback>
/usr/include/runetype.h:111:20: error: conflicting declaration =E2=80=98_Ru=
neLocale
_DefaultRuneLocale=E2=80=99

<snip include stack traceback>
/usr/include/runetype.h:111:20: note: previous declaration as =E2=80=98_Run=
eLocale@Foo
_DefaultRuneLocale@Foo=E2=80=99

=3D=3D=3D=3D

NOTE: iostream is _not_ built as a header unit in this case (if we do that =
the
problem disappears).

----

What seems wrong here is that the _RuneLocale symbol appears to be attached=
 to
Foo - but ir should be part of the GMF of Foo and not visible to importers
(although potentially reachable if used in the module purview of Foo).

unless i miss something?=