Re: [C++ PATCH] Only allow __label__ at the beginning of compound statements as documented (PR c++/32121)

[Chris Lattner <clattner at apple dot com>]

On Sep 28, 2007, at 12:02 PM, Tom Tromey wrote:

> > > > > > "Jakub" == Jakub Jelinek <jakub@redhat.com> writes:
>
> Jakub> Until GCC 3.3 we allowed it only at the beginning of the block
> Jakub> even for C++ and it is documented that way.
>
> Yeah.  If it changed back then, then perhaps people are using it.  I
> wonder.
>
> Anyway I'm just trying to look at it from a language design point of
> view.  I couldn't think of a reason to restrict this, particularly for
> C99/C++, where the parallel construct for variables works fine.

It's hard to handle code like this both correctly and efficiently:

void foo() {
  l:
    {
       goto l;
       __label__ l;
       l:
    }
}