Re: ToT glibc build problem with ToT GCC

[Carlos O'Donell <carlos at redhat dot com>]

On 8/29/19 1:28 PM, Martin Sebor wrote:
> A longer term solution is to replace the array with a suitably
> aligned char buffer and write the data into it, e.g., like this:
> 
>   union {
>     struct charseq replace[2];
>     char buf[sizeof (struct charseq) * 2];
>   } u;
> 
>   u.replace[0].nbytes = 1;
>   const char s[] = "?";
>   memcpy (u.buf + offsetof (struct charseq, bytes), "?", 2);
> 
> This is still iffy but it won't trigger an out-of-bounds warning.
> This code should still be flagged for the declaration of an object
> with an internal zero-length array, so that will need to be dealt
> with when such a warning is introduced (e.g., by suppressing
> the warning).

Why is this iffy? This is the kind of solution I was thinking of using.

The alternative is an entirely new type that has a non-zero-length
array that can be used for static object allocation like this, but then
you need to cast between them in a safe way?

-- 
Cheers,
Carlos.