diff options
| author | Nick Desaulniers <ndesaulniers@google.com> | 2023-01-12 04:05:01 +0100 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2023-01-26 04:41:38 +0100 |
| commit | d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0 (patch) | |
| tree | 49174312dd947dbb7321fc5672cc51b9bf1392a3 /scripts/Kconfig.include | |
| parent | MIPS: Prefer cc-option for additions to cflags (diff) | |
| download | linux-d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0.tar.xz linux-d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0.zip | |
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>
Diffstat (limited to 'scripts/Kconfig.include')
| -rw-r--r-- | scripts/Kconfig.include | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index 274125307ebd..5a84b6443875 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -33,7 +33,7 @@ ld-option = $(success,$(LD) -v $(1)) # $(as-instr,<instr>) # Return y if the assembler supports <instr>, n otherwise -as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -) +as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler-with-cpp -o /dev/null -) # check if $(CC) and $(LD) exist $(error-if,$(failure,command -v $(CC)),C compiler '$(CC)' not found) |