diff options
Diffstat (limited to 'target/linux/generic/backport-5.10/005-v5.17-02-Kbuild-move-to-std-gnu11.patch')
| -rw-r--r-- | target/linux/generic/backport-5.10/005-v5.17-02-Kbuild-move-to-std-gnu11.patch | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.10/005-v5.17-02-Kbuild-move-to-std-gnu11.patch b/target/linux/generic/backport-5.10/005-v5.17-02-Kbuild-move-to-std-gnu11.patch new file mode 100644 index 0000000000..7938fe5026 --- /dev/null +++ b/target/linux/generic/backport-5.10/005-v5.17-02-Kbuild-move-to-std-gnu11.patch @@ -0,0 +1,60 @@ +From b810c8e719ea082e47c7a8f7cf878bc84fa2455d Mon Sep 17 00:00:00 2001 +From: Arnd Bergmann <arnd@arndb.de> +Date: Tue, 8 Mar 2022 22:56:14 +0100 +Subject: [PATCH 2/3] Kbuild: move to -std=gnu11 + +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. + +An earlier attempt to do this when gcc-5 started defaulting to +-std=gnu11 failed because at the time that caused warnings about +designated initializers with older compilers. Now that gcc-5.1 is +the minimum compiler version used for building kernels, that is no +longer a concern. Similarly, the behavior of 'inline' functions changes +between gnu89 using gnu_inline behavior and gnu11 using standard c99+ +behavior, but this was taken care of by defining 'inline' to include +__attribute__((gnu_inline)) in order to allow building with clang a +while ago. + +Nathan Chancellor reported a new -Wdeclaration-after-statement +warning that appears in a system header on arm, this still needs a +workaround. + +The differences between gnu99, gnu11, gnu1x and gnu17 are fairly +minimal and mainly impact warnings at the -Wpedantic level that the +kernel never enables. Between these, gnu11 is the newest version +that is supported by all supported compiler versions, though it is +only the default on gcc-5, while all other supported versions of +gcc or clang default to gnu1x/gnu17. + +Link: https://lore.kernel.org/lkml/CAHk-=wiyCH7xeHcmiFJ-YgXUy2Jaj7pnkdKpcovt8fYbVFW3TA@mail.gmail.com/ +Link: https://github.com/ClangBuiltLinux/linux/issues/1603 +Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> +Acked-by: Marco Elver <elver@google.com> +Acked-by: Jani Nikula <jani.nikula@intel.com> +Acked-by: David Sterba <dsterba@suse.com> +Tested-by: Sedat Dilek <sedat.dilek@gmail.com> +Reviewed-by: Alex Shi <alexs@kernel.org> +Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> +Reviewed-by: Miguel Ojeda <ojeda@kernel.org> +Signed-off-by: Arnd Bergmann <arnd@arndb.de> +Reviewed-by: Nathan Chancellor <nathan@kernel.org> +Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> +--- + Makefile | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/Makefile ++++ b/Makefile +@@ -498,7 +498,7 @@ KBUILD_CFLAGS := -Wall -Wundef -Werror + -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \ + -Werror=implicit-function-declaration -Werror=implicit-int \ + -Werror=return-type -Wno-format-security \ +- -std=gnu89 ++ -std=gnu11 + KBUILD_CPPFLAGS := -D__KERNEL__ + KBUILD_AFLAGS_KERNEL := + KBUILD_CFLAGS_KERNEL := |