Hi Jan,
On Thu, Oct 08, 2020 at 04:33:04PM +0200, Jan Engelhardt wrote:
[...]
> Anyway, gcc-10/C mode does not reject embedding (and a number of maintainers
> have made it abundantly clear in the past they don't care if UAPI uses anti-C++
> "features"). Nonreject example:
>
> » cat x.c
> struct a2 {
> int x;
> int z[];
> };
> struct m {
> struct a2 y;
> long q;
> };
> » gcc -Wall -std=c11 -c -w -v x.c
> GNU C11 (SUSE Linux) version 10.2.1 20200825 [revision c0746a1beb1ba073c7981eb09f55b3d993b32e5c] (x86_64-suse-linux)
No need to pass '-w', gcc seems to accept the above unless one passes
'-pedantic' and thereby enables strict ISO C mode:
| % gcc -Wall -pedantic -std=c11 -c x.c
| x.c:6:19: warning: invalid use of structure with flexible array member [-Wpedantic]
| 6 | struct a2 y;
| | ^
While the question of whether kernel UAPI headers should adhere to
strict ISO C or not may be debatable, my motivation for working around
the situation in user space comes from Gustavo's complaints when I tried
to convert the relevant struct members into flexible arrays. He
apparently is a burnt child looking at commit 1e6e9d0f4859e ("uapi:
revert flexible-array conversions").
Cheers, Phil
