From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38035) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKLrg-0003CK-IV for qemu-devel@nongnu.org; Wed, 29 Jul 2015 03:33:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZKLrd-0006XQ-9d for qemu-devel@nongnu.org; Wed, 29 Jul 2015 03:33:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53145) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKLrd-0006XI-4P for qemu-devel@nongnu.org; Wed, 29 Jul 2015 03:33:21 -0400 From: Markus Armbruster References: <1435782155-31412-1-git-send-email-armbru@redhat.com> <1435782155-31412-8-git-send-email-armbru@redhat.com> <55B7E15D.50902@redhat.com> Date: Wed, 29 Jul 2015 09:33:17 +0200 In-Reply-To: <55B7E15D.50902@redhat.com> (Eric Blake's message of "Tue, 28 Jul 2015 14:09:01 -0600") Message-ID: <87lhdzju4i.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH RFC v2 07/47] qapi: Generate a nicer struct for flat unions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: kwolf@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com Eric Blake writes: > On 07/01/2015 02:21 PM, Markus Armbruster wrote: >> The struct generated for a flat union is weird: the members of its >> base are at the end, except for the union tag, which is renamed to >> 'kind' and put at the beginning. > > The renaming to 'kind' was a bug waiting to happen. Consider this > example, which is broken before your series: > > diff --git i/tests/qapi-schema/qapi-schema-test.json > w/tests/qapi-schema/qapi-schema-test.json > index c7eaa86..12c09e3 100644 > --- i/tests/qapi-schema/qapi-schema-test.json > +++ w/tests/qapi-schema/qapi-schema-test.json > @@ -37,7 +37,7 @@ > 'data': { 'string1': 'str', 'string2': 'str' } } > > { 'struct': 'UserDefUnionBase', > - 'data': { 'string': 'str', 'enum1': 'EnumOne' } } > + 'data': { 'kind': 'str', 'enum1': 'EnumOne' } } > > { 'union': 'UserDefFlatUnion', > 'base': 'UserDefUnionBase', > > > leading to this compilation error during 'make check-unit': > > In file included from tests/test-qmp-output-visitor.c:17:0: > tests/test-qapi-types.h:617:11: error: duplicate member =E2=80=98kind=E2= =80=99 > char *kind; > ^ > tests/test-qapi-types.h:631:11: error: duplicate member =E2=80=98kind=E2= =80=99 > char *kind; > ^ > > Therefore, it might be worth mentioning that avoiding the rename to > 'kind' is a bug fix, not just a nicer struct :) Cool! I'll work (a variation of) this test case into my series.