]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
kbuild: Update assembler calls to use proper flags and language target
authorNick Desaulniers <ndesaulniers@google.com>
Thu, 12 Jan 2023 03:05:01 +0000 (20:05 -0700)
committerMasahiro Yamada <masahiroy@kernel.org>
Thu, 26 Jan 2023 03:41:38 +0000 (12:41 +0900)
commitd5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0
tree49174312dd947dbb7321fc5672cc51b9bf1392a3
parent337ff6bb8960fdc128cabd264aaea3d42ca27a32
kbuild: Update assembler calls to use proper flags and language target

as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can
cause as-option to fail unexpectedly when CONFIG_WERROR is set, because
clang will emit -Werror,-Wunused-command-line-argument for various -m
and -f flags in KBUILD_CFLAGS for assembler sources.

Callers of as-option and as-instr should be adding flags to
KBUILD_AFLAGS / aflags-y, not KBUILD_CFLAGS / cflags-y. Use
KBUILD_AFLAGS in all macros to clear up the initial problem.

Unfortunately, -Wunused-command-line-argument can still be triggered
with clang by the presence of warning flags or macro definitions because
'-x assembler' is used, instead of '-x assembler-with-cpp', which will
consume these flags. Switch to '-x assembler-with-cpp' in places where
'-x assembler' is used, as the compiler is always used as the driver for
out of line assembler sources in the kernel.

Finally, add -Werror to these macros so that they behave consistently
whether or not CONFIG_WERROR is set.

[nathan: Reworded and expanded on problems in commit message
         Use '-x assembler-with-cpp' in a couple more places]

Link: https://github.com/ClangBuiltLinux/linux/issues/1699
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/Kconfig.include
scripts/Makefile.compiler
scripts/as-version.sh