From c90c6bfac6dfd6a7367f718df370b6a19756efe5 Mon Sep 17 00:00:00 2001 From: Behan Webster Date: Fri, 21 Apr 2017 11:20:01 -0700 Subject: [PATCH] UPSTREAM: kbuild: Add better clang cross build support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add cross target to CC if using clang. Also add custom gcc toolchain path for fallback gcc tools. Clang will fallback to using things like ld, as, and libgcc if (respectively) one of the llvm linkers isn't available, the integrated assembler is turned off, or an appropriately cross-compiled version of compiler-rt isn't available. To this end, you can specify the path to this fallback gcc toolchain with GCC_TOOLCHAIN. Signed-off-by: Behan Webster Reviewed-by: Jan-Simon Möller Reviewed-by: Mark Charlebois Signed-off-by: Greg Hackmann Signed-off-by: Matthias Kaehlcke Signed-off-by: Masahiro Yamada (cherry picked from commit 785f11aa595bc3d4e74096cbd598ada54ecc0d81) --- Makefile | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Makefile b/Makefile index feab5f5a507c..6595969ed89b 100644 --- a/Makefile +++ b/Makefile @@ -699,6 +699,15 @@ endif KBUILD_CFLAGS += $(stackp-flag) ifeq ($(cc-name),clang) +ifneq ($(CROSS_COMPILE),) +CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%)) +GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..) +endif +ifneq ($(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_CPPFLAGS += $(call cc-option,-Qunused-arguments,) KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,) KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)