Commit 46817c9a authored Oct 25, 2016 by Greg Hackmann Committed by Satya Durga Srinivasu Prabhala Jun 05, 2017

ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple



Android has an unusual setup where the kernel needs to target
[arch]-linux-gnu to avoid Android userspace-specific flags and
optimizations, but AOSP doesn't ship a matching binutils.

Add a new variable CLANG_TRIPLE which can override the "-target" triple
used to compile the kernel, while using a different CROSS_COMPILE to
pick the binutils/gcc installation.  For Android you'd do something
like:

  export CLANG_TRIPLE=aarch64-linux-gnu-
  export CROSS_COMPILE=aarch64-linux-android-

If you don't need something like this, leave CLANG_TRIPLE unset and it
will default to CROSS_COMPILE.

Change-Id: I6b2c100bd5d751997e142a7088a1095f35f7640c
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Git-commit: 12d62000883481ca0d4e9020be90aab8b8d47de6
Git-repo: https://android.googlesource.com/kernel/common/


[satyap@codeaurora.org: resolution of trivial merge conflicts]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

parent 96d47aed

Makefile

+2 −2

Original line number	Diff line number	Diff line
		@@ -379,7 +379,6 @@ LDFLAGS_vmlinux =
		CFLAGS_GCOV := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disable-warning,maybe-uninitialized,)
		CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)


		# Use USERINCLUDE when you must reference the UAPI directories only.
		USERINCLUDE := \
		-I$(srctree)/arch/$(hdr-arch)/include/uapi \
		@@ -699,7 +698,8 @@ KBUILD_CFLAGS += $(stackp-flag)

		ifeq ($(cc-name),clang)
		ifneq ($(CROSS_COMPILE),)
		CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%))
		CLANG_TRIPLE ?= $(CROSS_COMPILE)
		CLANG_TARGET := -target $(notdir $(CLANG_TRIPLE:%-=%))
		GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
		endif
		ifneq ($(GCC_TOOLCHAIN),)