> On Feb 23, 2023, at 5:04 PM, Qing Zhao via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>
>
>
>> On Feb 23, 2023, at 4:24 PM, Joseph Myers <jos...@codesourcery.com> wrote:
>>
>> On Thu, 23 Feb 2023, Qing Zhao via Gcc-patches wrote:
>>
>>> +@item
>>> +The structure with a C99 flexible array member is the field of
>>> +another union, for example:
>>> +
>>> +@smallexample
>>> +struct flex1 @{ int length1; char data1[]; @}
>>> +struct flex2 @{ int length2; char data2[]; @}
>>> +
>>> +union out_flex @{ struct flex1 flex_data1; struct flex2 flex_data2; @}
>>
>> I don't think this is an extension; structures with flexible array members
>> are OK in unions in standard C.
>
> Thanks for the info.
>
> Just checked the small testing case with -Wpedantic, Yes, it’s accepted
> without any warning.
> Will delete this item from the doc. And send the new patch soon.
But the following:
struct flex1 { int length1; char data1[]; };
struct flex2 { int length2; char data2[]; };
union union_flex { struct flex1 f1; struct flex2 f2; }; /* this is C standard.
*/
struct out_flex { int n; union union_flex flex_data1;}; /* this is GNU
extension. */
Should add this item into the documentation?
Qing
>
> Thanks.
>
> Qing
>>
>> --
>> Joseph S. Myers
>> jos...@codesourcery.com
