Re: RFC: Deprecate (a little bit) of C++ attribute syntax

[Mark Mitchell <mark at codesourcery dot com>]

--On Wednesday, August 14, 2002 02:08:17 AM +0200 Gabriel Dos Reis 
<gdr@integrable-solutions.net> wrote:

> Mark Mitchell <mark@codesourcery.com> writes:
>
> | Currently, the C++ front end accepts this syntax:
> |
> |   int x (3) __attribute__((unused));
>
> [...]
>
> | Therefore, I'm proposing deprecating this syntax in GCC 3.3 and
> | removing it in GCC 3.4 (with the new parser).
>
> |  I'm not sure if I can
> | get the old parser to actually warn about this (it's confused and
> | thinks the parenthesized initializer is part of the declarator, but
> | there is then later magic to untangle that!)
>
> Do you think it is the same reason why it seems to ignore
> attributes for nested typedef-names? I.e. in
>
>    struct A {
>       struct X { } __attribute__((__aligned__(4)));
>       typedef struct { } Y __attribute__((__aligned__(4)));
>    };
That's probably caused by something else -- but it could well be related.
> I mostly agree with all of yours suggestions -- as you know, I've been
> working on the attribute stuff these days.  The oddity you mention may
> be more prenicious.  Consider:
>
>    template<typename T>
>       struct X { } __attribute__((__aligned__(__alignof__(T))));
>
> This may, at first sight, look innocent, but it doesn't do the obvious
> thing one thinks of.
Again, similar -- but different.  (I was only worrying about the
parenthesized initializer case.)

The attributes after the curly brace case is interesting too, though.

This syntax (unlike the one I mentioned) has been supported by the C
front end for a long time, which makes it much harder to deprecate in
C++.

Thanks,

--
Mark Mitchell                mark@codesourcery.com
CodeSourcery, LLC            http://www.codesourcery.com