Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH] ARM: Drop '-mthumb' from AFLAGS_ISA | Date | Mon, 14 Nov 2022 15:57:20 -0700 |
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When building with CONFIG_THUMB2_KERNEL=y + a version of clang from Debian, the following warning occurs frequently:
<built-in>:383:9: warning: '__thumb2__' macro redefined [-Wmacro-redefined] #define __thumb2__ 2 ^ <built-in>:353:9: note: previous definition is here #define __thumb2__ 1 ^ 1 warning generated.
Debian carries a downstream patch that changes the default CPU of the arm-linux-gnueabihf target from 'arm1176jzf-s' (v6) to 'cortex-a7' (v7). As a result, '-mthumb' defines both '__thumb__' and '__thumb2__'. The define of '__thumb2__' via the command line was purposefully added to catch a situation like this.
In a similar vein as commit 26b12e084bce ("ARM: 9264/1: only use -mtp=cp15 for the compiler"), do not add '-mthumb' to AFLAGS_ISA, as it is already passed to the assembler via '-Wa,-mthumb' and '__thumb2__' is already defined for preprocessing.
Fixes: 1d2e9b67b001 ("ARM: 9265/1: pass -march= only to compiler") Link: htps://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/blob/17354b030ac4252ff6c5e9d01f4eba28bd406b2d/debian/patches/930008-arm.diff Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- arch/arm/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 357f0d9b8607..d1ebb746ff40 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -131,8 +131,9 @@ endif AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W) ifeq ($(CONFIG_THUMB2_KERNEL),y) -CFLAGS_ISA :=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN) +CFLAGS_ISA :=-Wa,-mimplicit-it=always $(AFLAGS_NOWARN) AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2 +CFLAGS_ISA +=-mthumb else CFLAGS_ISA :=$(call cc-option,-marm,) $(AFLAGS_NOWARN) AFLAGS_ISA :=$(CFLAGS_ISA) base-commit: 0c52591d22e99759da3793f19249bbf45ad742bd -- 2.38.1
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