aaron.ballman added a comment. In D133574#3816066 <https://reviews.llvm.org/D133574#3816066>, @nathanchance wrote:
> In D133574#3815951 <https://reviews.llvm.org/D133574#3815951>, @aaron.ballman > wrote: > >> LGTM, thank you! Please don't land until you have some indication from the >> kernel folks that this won't be super disruptive for them. CC >> @nickdesaulniers and @nathanchance for awareness. > > Thank you a lot for the heads up! I see an in-flight change around this from > YingChi on the mailing list: > > https://lore.kernel.org/20220925153151.2467884-1...@inclyc.cn/ > > It would be good to have that change accepted into a maintainer's tree and on > its way to mainline (Linus's tree) and by extension, the stable releases > before merging this into main, as we and several other groups are actively > testing all Linux branches with LLVM main to catch other regressions and this > error would require patching of our CI, which we can definitely do but prefer > to avoid because of the maintenance overhead (we try to carry zero patches at > all times). I don't think there's a rush to land this immediately, so we can definitely wait for you to give the all-clear. > I am still running my set of builds against the kernel with this LLVM change > and the aforementioned Linux change but I do see another error: > > drivers/media/platform/nvidia/tegra-vde/v4l2.c:816:49: error: '' cannot be > defined in 'offsetof' > ctx = kzalloc(offsetof(struct tegra_ctx, > ctrls[ARRAY_SIZE(ctrl_cfgs)]), > ^ > include/linux/kernel.h:55:59: note: expanded from macro 'ARRAY_SIZE' > #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + > __must_be_array(arr)) > ^ > include/linux/compiler.h:240:28: note: expanded from macro '__must_be_array' > #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) > ^ > include/linux/build_bug.h:16:44: note: expanded from macro > 'BUILD_BUG_ON_ZERO' > #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) > ^ > 1 error generated. > > I will report back with any additional problems found. Oh wow, that's a fun one for a few reasons. 1) Oops, we print `''` instead of mention that it's an anonymous struct, 2) that structure is actually declared in the scope surrounding the `sizeof` so it is technically being defined within `offsetof`, but 3) The standard requirement is "If the specified type defines a new type or if the specified member is a bit-field, the behavior is undefined." where "type" is the first parameter of the `offsetof` macro and this example does not define a new type there. So I *think* this situation is actually a false positive. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D133574/new/ https://reviews.llvm.org/D133574 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
