On Mon, Aug 13, 2018 at 8:11 PM, Jeff King <peff@xxxxxxxx> wrote:
> On Mon, Aug 13, 2018 at 01:17:18PM +0100, Ramsay Jones wrote:
>
>> >>> +struct island_bitmap {
>> >>> + uint32_t refcount;
>> >>> + uint32_t bits[];
>> >>
>> >> Use FLEX_ARRAY here? We are slowly moving toward requiring
>> >> certain C99 features, but I can't remember a flex array
>> >> weather-balloon patch.
>> >
>> > This was already discussed by Junio and Peff there:
>> >
>> > https://public-inbox.org/git/20180727130229.GB18599@xxxxxxxxxxxxxxxxxxxxx/
>>
>> That is a fine discussion, without a firm conclusion, but I don't
>> think you can simply do nothing here:
>>
>> $ cat -n junk.c
>> 1 #include <stdint.h>
>> 2
>> 3 struct island_bitmap {
>> 4 uint32_t refcount;
>> 5 uint32_t bits[];
>> 6 };
>> 7
>> $ gcc --std=c89 --pedantic -c junk.c
>> junk.c:5:11: warning: ISO C90 does not support flexible array members [-Wpedantic]
>> uint32_t bits[];
>> ^~~~
>> $ gcc --std=c99 --pedantic -c junk.c
>
> Right, whether we use the FLEX_ALLOC macros or not, this needs to be
> declared with FLEX_ARRAY, not an empty "[]".
Ok, it will use FLEX_ARRAY in the reroll I will send soon.
Thanks Ramsay and Peff!
