On Mon, Feb 28, 2022 at 11:27:43AM +0100, Arnd Bergmann wrote:
From: Arnd Bergmann arnd@arndb.de
During a patch discussion, Linus brought up the option of changing the C standard version from gnu89 to gnu99, which allows using variable declaration inside of a for() loop. While the C99, C11 and later standards introduce many other features, most of these are already available in gnu89 as GNU extensions as well.
The downside is that backporting affected patches to older kernel branches now fails with error messages such as
mm/kfence/core.c: In function ‘kfence_init_pool’: mm/kfence/core.c:595:2: error: ‘for’ loop initial declarations are only allowed in C99 or C11 mode
Just something to keep in mind when writing patches.
Guenter