| From foo@baz Wed Nov 21 18:50:25 CET 2018 |
| From: Behan Webster <behanw@converseincode.com> |
| Date: Fri, 21 Apr 2017 11:20:01 -0700 |
| Subject: kbuild: Add better clang cross build support |
| |
| From: Behan Webster <behanw@converseincode.com> |
| |
| commit 785f11aa595bc3d4e74096cbd598ada54ecc0d81 upstream. |
| |
| 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 <behanw@converseincode.com> |
| Reviewed-by: Jan-Simon Mรถller <dl9pf@gmx.de> |
| Reviewed-by: Mark Charlebois <charlebm@gmail.com> |
| Signed-off-by: Greg Hackmann <ghackmann@google.com> |
| Signed-off-by: Matthias Kaehlcke <mka@chromium.org> |
| Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> |
| Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| Makefile | 9 +++++++++ |
| 1 file changed, 9 insertions(+) |
| |
| --- a/Makefile |
| +++ b/Makefile |
| @@ -704,6 +704,15 @@ 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) |
