target/linux/generic/backport-5.15/005-v5.17-03-Kbuild-use-std-gnu11-for-KBUILD_USERCFLAGS.patch

   1 From 40337d6f3d677aee7ad3052ae662d3f53dd4d5cb Mon Sep 17 00:00:00 2001
   2 From: Arnd Bergmann <arnd@arndb.de>
   3 Date: Tue, 8 Mar 2022 22:56:15 +0100
   4 Subject: [PATCH 3/3] Kbuild: use -std=gnu11 for KBUILD_USERCFLAGS
   5
   6 As we change the C language standard for the kernel from gnu89 to
   7 gnu11, it makes sense to also update the version for user space
   8 compilation.
   9
  10 Some users have older native compilers than what they use for
  11 kernel builds, so I considered using gnu99 as the default version
  12 for wider compatibility with gcc-4.6 and earlier.
  13
  14 However, testing with older compilers showed that we already require
  15 HOSTCC version 5.1 as well because a lot of host tools include
  16 linux/compiler.h that uses __has_attribute():
  17
  18   CC      tools/objtool/exec-cmd.o
  19 In file included from tools/include/linux/compiler_types.h:36:0,
  20                  from tools/include/linux/compiler.h:5,
  21                  from exec-cmd.c:2:
  22 tools/include/linux/compiler-gcc.h:19:5: error: "__has_attribute" is not defined [-Werror=undef]
  23
  24 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
  25 Reviewed-by: Nathan Chancellor <nathan@kernel.org>
  26 Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
  27 Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
  28 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
  29 ---
  30  Makefile | 2 +-
  31  1 file changed, 1 insertion(+), 1 deletion(-)
  32
  33 --- a/Makefile
  34 +++ b/Makefile
  35 @@ -433,7 +433,7 @@ endif
  36  HOSTPKG_CONFIG = pkg-config
  37
  38  export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
  39 -                             -O2 -fomit-frame-pointer -std=gnu89 \
  40 +                             -O2 -fomit-frame-pointer -std=gnu11 \
  41                               -Wdeclaration-after-statement
  42  export KBUILD_USERLDFLAGS :=
  43