It "works" for the cases that I currently care about but I have to say that I am uneasy about adding -Werror to the cc-option test in this way. Suppose that one of the *other* flags that is implicitly passed to the compiler by cc-option - eg something that was explicitly specified in $(KBUILD_CFLAGS) - triggers a warning. In that case all calls to cc-option will silently fail because of the -Werror and valid options will not be detected correctly. If everyone is OK with that because "it shouldn't normally ever happen" then that is fine, but if does result in a subtle change from existing behavior (and a trap that I almost immediately fell into after applying a similar patch). On Wed, Apr 5, 2017 at 12:01 PM, Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote: > Hi Masahiro, > > El Thu, Apr 06, 2017 at 03:08:26AM +0900 Masahiro Yamada ha dit: > >> 2017-03-17 9:15 GMT+09:00 Michael Davidson <md@xxxxxxxxxx>: >> > Unfortunately, while clang generates a warning about these flags >> > being unsupported it still exits with a status of 0 so we have >> > to explicitly disable them instead of just using a cc-option check. >> > >> > Signed-off-by: Michael Davidson <md@xxxxxxxxxx> >> >> >> Instead, does the following work for you? >> https://patchwork.kernel.org/patch/9657285/ > > Thanks for the pointer, I was about to give this change (or rather its > ancestor) a rework myself :) > >> You need to use >> $(call cc-option, ...) >> for -falign-jumps=1 and -falign-loops=1 > > I can confirm that this works. > > Thanks > > Matthias
