Re: [PATCH v8 1/5] Provide counted_by attribute to flexible array member field (PR108896)

[Qing Zhao <qing.zhao@oracle.com>]

> On Apr 10, 2024, at 17:56, Joseph Myers <josmyers@redhat.com> wrote:
> 
> On Wed, 10 Apr 2024, Qing Zhao wrote:
> 
>> Okay, the above is very clear, thanks a lot for the explanation.
>> So, basically, for “counted-by” attribute:
>> **The following is good:
>> struct f { 
>>  int b;
>>  int c;
>>  int a[]  __attribute__ ((counted_by (b))) };
>> struct f {
>>  int b;
>>  int c;
>>  int a[] __attribute__ ((counted_by (b))) };
>> 
>> **The following should error:
>> 
>> struct f { 
>>  int b;
>>  int c;
>>  int a[]  __attribute__ ((counted_by (b))) };
>> struct f {
>>  int b;
>>  int c;
>>  int a[] __attribute__ ((counted_by (c))) };  /* error here */
>> 
>> For the same tag in different scopes case:
>> 
>> struct f { 
>>  int b;
>>  int c;
>>  int a[]  __attribute__ ((counted_by (b))) }  y0;
>> 
>> void test1(void) 
>> {   
>> struct f {
>>  int b;
>>  int c;
>>  int a[] __attribute__ ((counted_by (c))) } x;
>> 
>>  y0 = x;  /* will report incompatible type error here */
>> }
>> 
>> Are the above complete?
> 
> Yes, that looks like what should be tested (with the addition of the case 
> of same tag, different scopes, same counted_by so compatible).

Okay, thanks for the help.

Qing
> 
> -- 
> Joseph S. Myers
> josmyers@redhat.com