Re: fun with declarations and definitions

From: Christopher Li <sparse@chrisli.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Derek M Jones <derek@knosof.co.uk>, linux-sparse@vger.kernel.org
Subject: Re: fun with declarations and definitions
Date: Sun, 8 Feb 2009 23:52:23 -0800	[thread overview]
Message-ID: <70318cbf0902082352n32450ca2g87c847bb035baf15@mail.gmail.com> (raw)
In-Reply-To: <20090206053655.GS28946@ZenIV.linux.org.uk>

On Thu, Feb 5, 2009 at 9:36 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Thu, Feb 05, 2009 at 09:19:21PM +0000, Al Viro wrote:
>> IOW, direct_declarator() (which doubles for direct-abstract-declarator) should
>> have more than one-bit indication of which case we've got.  Right now it's
>> done by "have we passed a non-NULL ident ** to store the identifier being
>> declared"; that's not enough.  What we need is explicit 'is that a part of
>> parameter declaration' flag; then the rule turns into
>>       if (p && *p)
>>               fn = 1; /* we'd seen identifier already, can't be nested */
>>       else if match_op(next, ')')
>>               fn = 1; /* empty list can't be direct-declarator or
>>                        * direct-abstract-declarator */
>>       else
>>               fn = (in_parameter && lookup_type(next));
>
> Umm...  It's a bit more subtle (p goes NULL after the nested one is
> handled), so we need to keep track of "don't allow nested declarator from
> that point on" explicitly.  Patch follows:
>
> Subject: [PATCH] Handle nested declarators vs. parameter lists correctly
>
> Seeing a typedef name after ( means that we have a parameter-type-list
> only if we are parsing a parameter declaration or a typename; otherwise
> it might very well be a redeclaration (e.g. int (T); when T had been a
> typedef in outer scope).

The patch looks great. Applied.

Chris