Commit 5d15d2e0 authored Oct 25, 2016 by Greg Hackmann

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: I85d63599c6ab8ed458071cdf9197d85b1f7f150b
Signed-off-by: Greg Hackmann <ghackmann@google.com>

parent c3d5669e

Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -701,7 +701,8 @@ 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),)