From: Arnd Bergmann <arnd@xxxxxxxx> As we change the C language standard for the kernel from gnu89 to gnu11, it makes sense to also update the version for user space compilation. Some users have older native compilers than what they use for kernel builds, so I considered using gnu99 as the default version for wider compatibility with gcc-4.6 and earlier. However, testing with older compilers showed that we already require HOSTCC version 5.1 as well because a lot of host tools include linux/compiler.h that uses __has_attribute(): CC tools/objtool/exec-cmd.o In file included from tools/include/linux/compiler_types.h:36:0, from tools/include/linux/compiler.h:5, from exec-cmd.c:2: tools/include/linux/compiler-gcc.h:19:5: error: "__has_attribute" is not defined [-Werror=undef] Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 1ba8dc523952..e0b11ddd0760 100644 --- a/Makefile +++ b/Makefile @@ -432,7 +432,7 @@ HOSTCXX = g++ endif KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu89 \ + -O2 -fomit-frame-pointer -std=gnu11 \ -Wdeclaration-after-statement KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS) KBUILD_USERLDFLAGS := $(USERLDFLAGS) -- 2.29.2