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Subject: Re: [C++ Patch] PR 67065 ("Missing diagnostics for ill-formed program with main variable instead of function")
To: Ville Voutilainen <ville.voutilainen@gmail.com>,        "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,        Jason Merrill <jason@redhat.com>
References: <CAFk2RUZWCBcBOQtTh3s-HTkiny==Wmi2XUOAxrpd3+t1_GCa-g@mail.gmail.com>
From: Paolo Carlini <paolo.carlini@oracle.com>
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Date: Wed, 19 Aug 2015 20:28:00 -0000
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Hi Ville,

On 08/19/2015 10:12 PM, Ville Voutilainen wrote:
>> submitter noticed that, in violation of [basic.start.main], we don't reject
>> as ill-formed the declaration of a 'main' variable in the global namespace.
>> Not a big deal IMHO, but the below simple check works well for me on x86_64-linux.
> Just fyi, gcc accepts
>
> decltype(main) x;
>
> decltype(sizeof(decltype(main)*)) x;
>
> which are "uses" of main and also violate [basic.start.main]/3.
"good" to know. In my experience sometimes the front end appears to 
so-to-speak pre-declare entities. For instance I filed a while ago 
c++/48396. Not sure if in practice the exact same code is involved...

Paolo.