From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35197)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1Yc8ji-0005k1-7p
	for qemu-devel@nongnu.org; Sun, 29 Mar 2015 04:38:27 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1Yc8jf-0000lU-1t
	for qemu-devel@nongnu.org; Sun, 29 Mar 2015 04:38:26 -0400
Received: from mx1.redhat.com ([209.132.183.28]:53793)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1Yc8je-0000lM-Ph
	for qemu-devel@nongnu.org; Sun, 29 Mar 2015 04:38:22 -0400
From: Markus Armbruster <armbru@redhat.com>
References: <1427227433-5030-1-git-send-email-eblake@redhat.com>
	<1427227433-5030-17-git-send-email-eblake@redhat.com>
	<87wq22ubb8.fsf@blackfin.pond.sub.org> <5515B553.2010606@redhat.com>
Date: Sun, 29 Mar 2015 10:38:17 +0200
In-Reply-To: <5515B553.2010606@redhat.com> (Eric Blake's message of "Fri, 27
	Mar 2015 13:53:55 -0600")
Message-ID: <87h9t45hc6.fsf@blackfin.pond.sub.org>
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: [Qemu-devel] [PATCH v5 16/28] qapi: Better error messages for
	duplicated expressions
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Eric Blake <eblake@redhat.com>
Cc: kwolf@redhat.com, famz@redhat.com, qemu-devel@nongnu.org, wenchaoqemu@gmail.com, lcapitulino@redhat.com

Eric Blake <eblake@redhat.com> writes:

> On 03/27/2015 01:52 AM, Markus Armbruster wrote:
>> One more...
>> 
>> Eric Blake <eblake@redhat.com> writes:
>> 
>> [...]
>>> diff --git a/scripts/qapi.py b/scripts/qapi.py
>>> index 90eb3bc..5d0dc91 100644
>>> --- a/scripts/qapi.py
>>> +++ b/scripts/qapi.py
>> [...]
>>> @@ -560,12 +585,22 @@ def type_name(name):
>>>          return c_list_type(name[0])
>>>      return name
>>>
>>> -enum_types = []
>>> -struct_types = []
>>> -union_types = []
>>> +def add_name(name, info, meta, implicit = False):
>>> +    global all_names
>>> +    if name in all_names:
>>> +        raise QAPIExprError(info,
>>> +                            "%s '%s' is already defined"
>>> +                            %(all_names[name], name))
>> 
>> We say "struct 'Foo'", and expect the user to know that 'struct' means
>> 'complex type'.  It'll do, it's just a development tool.
>
> In fact, I considered making it "type 'Foo'", to match that the item is
> declared with { 'type':'Foo' ...} and not { 'struct':'Foo' ...}.  But
> type is an ambiguous word.  I'm half tempted to do a global
> search-and-replace of s/'type'/'struct'/ in the json files, since
> 'union' is also a type.  Obviously as its own patch.

No objections.  The churn will be a bit annoying with git-blame, but I'd
prefer that to continuing with confusing terminology.

>> 
>> I'm not really happy with 'complex type', though.  Isn't a union type
>> complex, too?  Anyway, we can clean up our confused terminology later;
>> this series is long enough.
>
> Hmm. If I _do_ the global rename, then we have a nice hierarchy:
>
> type  -  simple type: built-in, enum
>       -  alternate
>       -  complex type: struct, union

Indeed.

The odd in-between-ness of alternate here is additional justification
for you separating it from union.