Re: [PATCH][next] zd1211rw/zd_usb.h: Replace zero-length array with flexible-array member

Jes Sorensen
2020-03-10T22:34:37Z

On 3/10/20 6:31 PM, Gustavo A. R. Silva wrote:
>
>
> On 3/10/20 5:20 PM, Jes Sorensen wrote:
>> On 3/10/20 6:13 PM, Gustavo A. R. Silva wrote:
>>>
>>>
>>> On 3/10/20 5:07 PM, Jes Sorensen wrote:
>>>> As I stated in my previous answer, this seems more code churn than an
>>>> actual fix. If this is a real problem, shouldn't the work be put into
>>>> fixing the compiler to handle foo[0] instead? It seems that is where the
>>>> real value would be.
>>>
>>> Yeah. But, unfortunately, I'm not a compiler guy, so I'm not able to fix the
>>> compiler as you suggest. And I honestly don't see what is so annoying/disturbing
>>> about applying a patch that removes the 0 from foo[0] when it brings benefit
>>> to the whole codebase.
>>
>> My point is that it adds what seems like unnecessary churn, which is not
>> a benefit, and it doesn't improve the generated code.
>>
>
> As an example of one of the benefits of this is that the compiler won't trigger
> a warning in the following case:
>
> struct boo {
> int stuff;
> struct foo array[0];
> int morestuff;
> };
>
> The result of the code above is an undefined behavior.
>
> On the other hand in the case below, the compiles does trigger a warning:
>
> struct boo {
> int stuff;
> struct foo array[];
> int morestuff;
> };

Right, this just underlines my prior argument, that this should be fixed
in the compiler.

Jes