From 4c219af48b1e64222a71af333caf574deb5e1b2f Mon Sep 17 00:00:00 2001 From: Stefan Agner <stefan@agner.ch> Date: Wed, 5 Dec 2018 16:45:26 -0800 Subject: [PATCH] kbuild: allow to use GCC toolchain not in Clang search path (commit ef8c4ed9db80261f397f0c0bf723684601ae3b52 upstream) 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 $PATH for a matching assembler or linker. Make sure that Clang picks up the correct assembler or linker by passing the cross compilers bin directory as search path. This allows to use Clang provided by distributions with GCC toolchains not in /usr/bin. Link: https://github.com/ClangBuiltLinux/linux/issues/78 Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-and-tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> [ND: adjusted to context, due to adjusting the context of my previous backport of upstream's ae6b289a3789] Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- Makefile | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index c62b2b5297249..ae53662eb7815 100644 --- a/Makefile +++ b/Makefile @@ -512,13 +512,15 @@ endif ifeq ($(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_CPPFLAGS += $(call cc-option,-Qunused-arguments,) KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable) KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)