forked from Minki/linux
231ad7f409
We get constant feedback that the command line invocation of make is too long when compiling with LLVM. CROSS_COMPILE is helpful when a toolchain has a prefix of the target triple, or is an absolute path outside of $PATH. Since a Clang binary is generally multi-targeted, we can infer a given target from SRCARCH/ARCH. If CROSS_COMPILE is not set, simply set --target= for CLANG_FLAGS, KBUILD_CFLAGS, and KBUILD_AFLAGS based on $SRCARCH. Previously, we'd cross compile via: $ ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make LLVM=1 LLVM_IAS=1 Now: $ ARCH=arm64 make LLVM=1 LLVM_IAS=1 For native builds (not involving cross compilation) we now explicitly specify a target triple rather than rely on the implicit host triple. Link: https://github.com/ClangBuiltLinux/linux/issues/1399 Suggested-by: Arnd Bergmann <arnd@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Suggested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Arnd Bergmann <arnd@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
36 lines
1.3 KiB
Makefile
36 lines
1.3 KiB
Makefile
# Individual arch/{arch}/Makefiles should use -EL/-EB to set intended
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# endianness and -m32/-m64 to set word size based on Kconfigs instead of
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# relying on the target triple.
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CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi
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CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu
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CLANG_TARGET_FLAGS_hexagon := hexagon-linux-musl
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CLANG_TARGET_FLAGS_m68k := m68k-linux-gnu
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CLANG_TARGET_FLAGS_mips := mipsel-linux-gnu
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CLANG_TARGET_FLAGS_powerpc := powerpc64le-linux-gnu
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CLANG_TARGET_FLAGS_riscv := riscv64-linux-gnu
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CLANG_TARGET_FLAGS_s390 := s390x-linux-gnu
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CLANG_TARGET_FLAGS_x86 := x86_64-linux-gnu
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CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(SRCARCH))
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ifeq ($(CROSS_COMPILE),)
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ifeq ($(CLANG_TARGET_FLAGS),)
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$(error Specify CROSS_COMPILE or add '--target=' option to scripts/Makefile.clang)
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else
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CLANG_FLAGS += --target=$(CLANG_TARGET_FLAGS)
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endif # CLANG_TARGET_FLAGS
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else
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CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
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endif # CROSS_COMPILE
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ifeq ($(LLVM_IAS),1)
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CLANG_FLAGS += -integrated-as
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else
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CLANG_FLAGS += -no-integrated-as
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GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
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CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
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endif
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CLANG_FLAGS += -Werror=unknown-warning-option
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KBUILD_CFLAGS += $(CLANG_FLAGS)
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KBUILD_AFLAGS += $(CLANG_FLAGS)
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export CLANG_FLAGS
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