Commit ef8c4ed9 authored Sep 17, 2018 by Stefan Agner Committed by Masahiro Yamada Sep 19, 2018

kbuild: allow to use GCC toolchain not in Clang search path

When using a GCC cross toolchain which is not in a compiled in
Clang search path, Clang reverts to the system assembler and
linker. This leads to assembler or linker errors, depending on
which tool is first used for a given architecture.

It seems that Clang is not searching $PATH for a matching
assembler or linker.

Make sure that Clang picks up the correct assembler or linker by
passing the cross compilers bin directory as search path.

This allows to use Clang provided by distributions with GCC
toolchains not in /usr/bin.

Link: https://github.com/ClangBuiltLinux/linux/issues/78


Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-and-tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

parent 5a4630aa

Makefile

+5 −3

Original line number	Diff line number	Diff line
		@@ -495,13 +495,15 @@ endif
		ifeq ($(cc-name),clang)
		ifneq ($(CROSS_COMPILE),)
		CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%))
		GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
		GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
		CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR)
		GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
		endif
		ifneq ($(GCC_TOOLCHAIN),)
		CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN)
		endif
		KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
		KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC)
		KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
		KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
		KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
		KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
		endif

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