diff options
| author | Nick Desaulniers <ndesaulniers@google.com> | 2023-01-11 20:05:01 -0700 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2023-01-26 12:41:38 +0900 |
| commit | d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0 (patch) | |
| tree | 49174312dd947dbb7321fc5672cc51b9bf1392a3 /scripts/Makefile.compiler | |
| parent | 337ff6bb8960fdc128cabd264aaea3d42ca27a32 (diff) | |
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/Makefile.compiler')
| -rw-r--r-- | scripts/Makefile.compiler | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler index 3d8adfd34af1..7aa1fbc4aafe 100644 --- a/scripts/Makefile.compiler +++ b/scripts/Makefile.compiler @@ -29,16 +29,16 @@ try-run = $(shell set -e; \ fi) # as-option -# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) +# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,) as-option = $(call try-run,\ - $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) + $(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2)) # as-instr -# Usage: cflags-y += $(call as-instr,instr,option1,option2) +# Usage: aflags-y += $(call as-instr,instr,option1,option2) as-instr = $(call try-run,\ - printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) + printf "%b\n" "$(1)" | $(CC) -Werror $(KBUILD_AFLAGS) -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3)) # __cc-option # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) |