Refactor llvm_config.mk and support the 2nd arch

1. Following the setup of gcc in build/core/combo/,
we added the [HOST|TARGET]_<arch>.mk clang config files,
and load only the configs needed by the current product.
2. Added support for the 2nd arch.

Change-Id: I2a383418a9688a050b39492f8e489d40eeeb5f2d
diff --git a/core/clang/HOST_x86.mk b/core/clang/HOST_x86.mk
new file mode 100644
index 0000000..f38f04e
--- /dev/null
+++ b/core/clang/HOST_x86.mk
@@ -0,0 +1,55 @@
+
+include $(BUILD_SYSTEM)/clang/x86.mk
+
+ifeq ($(HOST_OS),linux)
+CLANG_CONFIG_x86_HOST_TRIPLE := i686-linux-gnu
+endif
+ifeq ($(HOST_OS),darwin)
+CLANG_CONFIG_x86_HOST_TRIPLE := i686-apple-darwin
+endif
+ifeq ($(HOST_OS),windows)
+CLANG_CONFIG_x86_HOST_TRIPLE := i686-pc-mingw32
+endif
+
+CLANG_CONFIG_x86_HOST_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_x86_HOST_TRIPLE) \
+
+CLANG_CONFIG_x86_HOST_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_HOST_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_x86_HOST_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_x86_HOST_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_x86_HOST_TRIPLE) \
+
+
+define convert-to-host-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-x86-flags,\
+  $(filter-out $(CLANG_CONFIG_x86_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+CLANG_HOST_GLOBAL_CFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_x86_HOST_EXTRA_CFLAGS)
+
+CLANG_HOST_GLOBAL_CPPFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_x86_HOST_EXTRA_CPPFLAGS)
+
+CLANG_HOST_GLOBAL_LDFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_x86_HOST_EXTRA_LDFLAGS)
diff --git a/core/clang/HOST_x86_64.mk b/core/clang/HOST_x86_64.mk
new file mode 100644
index 0000000..ea33a46
--- /dev/null
+++ b/core/clang/HOST_x86_64.mk
@@ -0,0 +1,55 @@
+
+include $(BUILD_SYSTEM)/clang/x86_64.mk
+
+ifeq ($(HOST_OS),linux)
+CLANG_CONFIG_x86_64_HOST_TRIPLE := x86_64-linux-gnu
+endif
+ifeq ($(HOST_OS),darwin)
+CLANG_CONFIG_x86_64_HOST_TRIPLE := x86_64-apple-darwin
+endif
+ifeq ($(HOST_OS),windows)
+CLANG_CONFIG_x86_64_HOST_TRIPLE := x86_64-pc-mingw64
+endif
+
+CLANG_CONFIG_x86_64_HOST_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_x86_64_HOST_TRIPLE) \
+
+CLANG_CONFIG_x86_64_HOST_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_64_HOST_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_x86_64_HOST_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_x86_64_HOST_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_HOST_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_x86_64_HOST_TRIPLE) \
+
+
+define convert-to-host-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-x86_64-flags,\
+  $(filter-out $(CLANG_CONFIG_x86_64_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+CLANG_HOST_GLOBAL_CFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_x86_64_HOST_EXTRA_CFLAGS)
+
+CLANG_HOST_GLOBAL_CPPFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_x86_64_HOST_EXTRA_CPPFLAGS)
+
+CLANG_HOST_GLOBAL_LDFLAGS := \
+  $(call convert-to-host-clang-flags,$(HOST_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_x86_64_HOST_EXTRA_LDFLAGS)
diff --git a/core/clang/TARGET_arm.mk b/core/clang/TARGET_arm.mk
new file mode 100644
index 0000000..373f276
--- /dev/null
+++ b/core/clang/TARGET_arm.mk
@@ -0,0 +1,53 @@
+
+include $(BUILD_SYSTEM)/clang/arm.mk
+
+CLANG_CONFIG_arm_TARGET_TRIPLE := arm-linux-androideabi
+CLANG_CONFIG_arm_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/$(CLANG_CONFIG_arm_TARGET_TRIPLE)/bin
+
+CLANG_CONFIG_arm_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_arm_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_arm_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_arm_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_arm_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_arm_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_arm_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_arm_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_arm_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_arm_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_arm_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_arm_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_arm_TARGET_TOOLCHAIN_PREFIX)
+
+
+define $(clang_2nd_arch_prefix)convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-arm-flags,\
+  $(filter-out $(CLANG_CONFIG_arm_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_arm_TARGET_EXTRA_CFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_arm_TARGET_EXTRA_CPPFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_arm_TARGET_EXTRA_LDFLAGS)
+
+$(clang_2nd_arch_prefix)RS_TRIPLE := armv7-none-linux-gnueabi
diff --git a/core/clang/TARGET_arm64.mk b/core/clang/TARGET_arm64.mk
new file mode 100644
index 0000000..16027fa
--- /dev/null
+++ b/core/clang/TARGET_arm64.mk
@@ -0,0 +1,54 @@
+
+include $(BUILD_SYSTEM)/clang/arm64.mk
+
+CLANG_CONFIG_arm64_TARGET_TRIPLE := aarch64-linux-androideabi
+CLANG_CONFIG_arm64_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/$(CLANG_CONFIG_arm64_TARGET_TRIPLE)/bin
+
+CLANG_CONFIG_arm64_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_arm64_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_arm64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_arm64_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_arm64_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_arm64_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_arm64_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_arm64_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_arm64_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_arm64_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_arm64_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_arm64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_arm64_TARGET_TOOLCHAIN_PREFIX)
+
+
+define convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-arm64-flags,\
+  $(filter-out $(CLANG_CONFIG_arm64_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_arm64_TARGET_EXTRA_CFLAGS)
+
+CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_arm64_TARGET_EXTRA_CPPFLAGS)
+
+CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_arm64_TARGET_EXTRA_LDFLAGS)
+
+$(warning Incorrect arm64 RS_TRIPLE, fix me!)
+RS_TRIPLE := armv7-none-linux-gnueabi
diff --git a/core/clang/TARGET_mips.mk b/core/clang/TARGET_mips.mk
new file mode 100644
index 0000000..215a8ae
--- /dev/null
+++ b/core/clang/TARGET_mips.mk
@@ -0,0 +1,53 @@
+
+include $(BUILD_SYSTEM)/clang/mips.mk
+
+CLANG_CONFIG_mips_TARGET_TRIPLE := mipsel-linux-android
+CLANG_CONFIG_mips_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/$(CLANG_CONFIG_mips_TARGET_TRIPLE)/bin
+
+CLANG_CONFIG_mips_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_mips_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_mips_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_mips_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_mips_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_mips_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_mips_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_mips_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_mips_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_mips_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_mips_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_mips_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_mips_TARGET_TOOLCHAIN_PREFIX)
+
+
+define $(clang_2nd_arch_prefix)convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-mips-flags,\
+  $(filter-out $(CLANG_CONFIG_mips_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_mips_TARGET_EXTRA_CFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$(clang_2nd_arch_prefix)$(TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_mips_TARGET_EXTRA_CPPFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_mips_TARGET_EXTRA_LDFLAGS)
+
+$(clang_2nd_arch_prefix)RS_TRIPLE := mipsel-unknown-linux
diff --git a/core/clang/TARGET_mips64.mk b/core/clang/TARGET_mips64.mk
new file mode 100644
index 0000000..b2e536c
--- /dev/null
+++ b/core/clang/TARGET_mips64.mk
@@ -0,0 +1,53 @@
+
+include $(BUILD_SYSTEM)/clang/mips64.mk
+
+CLANG_CONFIG_mips64_TARGET_TRIPLE := mips64el-linux-android
+CLANG_CONFIG_mips64_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/$(CLANG_CONFIG_mips64_TARGET_TRIPLE)/bin
+
+CLANG_CONFIG_mips64_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_mips64_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_mips64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_mips64_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_mips64_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_mips64_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_mips64_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_mips64_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_mips64_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_mips64_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_mips64_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_mips64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_mips64_TARGET_TOOLCHAIN_PREFIX)
+
+
+define convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-mips64-flags,\
+  $(filter-out $(CLANG_CONFIG_mips64_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_mips64_TARGET_EXTRA_CFLAGS)
+
+CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_mips64_TARGET_EXTRA_CPPFLAGS)
+
+CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_mips64_TARGET_EXTRA_LDFLAGS)
+
+RS_TRIPLE := mips64el-unknown-linux
diff --git a/core/clang/TARGET_x86.mk b/core/clang/TARGET_x86.mk
new file mode 100644
index 0000000..0178093
--- /dev/null
+++ b/core/clang/TARGET_x86.mk
@@ -0,0 +1,53 @@
+
+include $(BUILD_SYSTEM)/clang/x86.mk
+
+CLANG_CONFIG_x86_TARGET_TRIPLE := i686-linux-android
+CLANG_CONFIG_x86_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/x86_64-linux-android/bin
+
+CLANG_CONFIG_x86_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_x86_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_x86_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_x86_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_x86_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_x86_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_x86_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_x86_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_x86_TARGET_TOOLCHAIN_PREFIX)
+
+
+define $(clang_2nd_arch_prefix)convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-x86-flags,\
+  $(filter-out $(CLANG_CONFIG_x86_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_x86_TARGET_EXTRA_CFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_x86_TARGET_EXTRA_CPPFLAGS)
+
+$(clang_2nd_arch_prefix)CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call $(clang_2nd_arch_prefix)convert-to-clang-flags,$($(clang_2nd_arch_prefix)TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_x86_TARGET_EXTRA_LDFLAGS)
+
+$(clang_2nd_arch_prefix)RS_TRIPLE := i686-unknown-linux
diff --git a/core/clang/TARGET_x86_64.mk b/core/clang/TARGET_x86_64.mk
new file mode 100644
index 0000000..14944bd
--- /dev/null
+++ b/core/clang/TARGET_x86_64.mk
@@ -0,0 +1,53 @@
+
+include $(BUILD_SYSTEM)/clang/x86_64.mk
+
+CLANG_CONFIG_x86_64_TARGET_TRIPLE := x86_64-linux-android
+CLANG_CONFIG_x86_64_TARGET_TOOLCHAIN_PREFIX := \
+  $(TARGET_TOOLCHAIN_ROOT)/$(CLANG_CONFIG_x86_64_TARGET_TRIPLE)/bin
+
+CLANG_CONFIG_x86_64_TARGET_EXTRA_ASFLAGS := \
+  $(CLANG_CONFIG_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_ASFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_ASFLAGS) \
+  -target $(CLANG_CONFIG_x86_64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_x86_64_TARGET_TOOLCHAIN_PREFIX)
+
+CLANG_CONFIG_x86_64_TARGET_EXTRA_CFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_CFLAGS) \
+  $(CLANG_CONFIG_x86_64_TARGET_EXTRA_ASFLAGS)
+
+CLANG_CONFIG_x86_64_TARGET_EXTRA_CPPFLAGS := \
+  $(CLANG_CONFIG_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_CPPFLAGS) \
+
+CLANG_CONFIG_x86_64_TARGET_EXTRA_LDFLAGS := \
+  $(CLANG_CONFIG_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_TARGET_EXTRA_LDFLAGS) \
+  $(CLANG_CONFIG_x86_64_EXTRA_LDFLAGS) \
+  -target $(CLANG_CONFIG_x86_64_TARGET_TRIPLE) \
+  -B$(CLANG_CONFIG_x86_64_TARGET_TOOLCHAIN_PREFIX)
+
+
+define convert-to-clang-flags
+  $(strip \
+  $(call subst-clang-incompatible-x86_64-flags,\
+  $(filter-out $(CLANG_CONFIG_x86_64_UNKNOWN_CFLAGS),\
+  $(1))))
+endef
+
+CLANG_TARGET_GLOBAL_CFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CFLAGS)) \
+  $(CLANG_CONFIG_x86_64_TARGET_EXTRA_CFLAGS)
+
+CLANG_TARGET_GLOBAL_CPPFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_CPPFLAGS)) \
+  $(CLANG_CONFIG_x86_64_TARGET_EXTRA_CPPFLAGS)
+
+CLANG_TARGET_GLOBAL_LDFLAGS := \
+  $(call convert-to-clang-flags,$(TARGET_GLOBAL_LDFLAGS)) \
+  $(CLANG_CONFIG_x86_64_TARGET_EXTRA_LDFLAGS)
+
+RS_TRIPLE := x86_64-unknown-linux
diff --git a/core/clang/arm.mk b/core/clang/arm.mk
new file mode 100644
index 0000000..28d87bb
--- /dev/null
+++ b/core/clang/arm.mk
@@ -0,0 +1,27 @@
+# Clang flags for arm arch, target or host.
+
+CLANG_CONFIG_arm_EXTRA_ASFLAGS :=
+
+CLANG_CONFIG_arm_EXTRA_CFLAGS := \
+  -mllvm -arm-enable-ehabi
+
+CLANG_CONFIG_arm_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_arm_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -mthumb-interwork \
+  -fgcse-after-reload \
+  -frerun-cse-after-loop \
+  -frename-registers \
+  -fno-builtin-sin \
+  -fno-strict-volatile-bitfields \
+  -fno-align-jumps \
+  -Wa,--noexecstack
+
+define subst-clang-incompatible-arm-flags
+  $(subst -march=armv5te,-march=armv5t,\
+  $(subst -march=armv5e,-march=armv5,\
+  $(subst -mcpu=cortex-a15,-march=armv7-a,\
+  $(1))))
+endef
diff --git a/core/clang/arm64.mk b/core/clang/arm64.mk
new file mode 100644
index 0000000..a52a662
--- /dev/null
+++ b/core/clang/arm64.mk
@@ -0,0 +1,29 @@
+# Clang flags for arm64 arch, target or host.
+
+$(warning Untested arm64 clang flags, fix me!)
+
+CLANG_CONFIG_arm64_EXTRA_ASFLAGS :=
+
+CLANG_CONFIG_arm64_EXTRA_CFLAGS := \
+  -mllvm -arm-enable-ehabi
+
+CLANG_CONFIG_arm64_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_arm64_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -mthumb-interwork \
+  -fgcse-after-reload \
+  -frerun-cse-after-loop \
+  -frename-registers \
+  -fno-builtin-sin \
+  -fno-strict-volatile-bitfields \
+  -fno-align-jumps \
+  -Wa,--noexecstack
+
+define subst-clang-incompatible-arm64-flags
+  $(subst -march=armv5te,-march=armv5t,\
+  $(subst -march=armv5e,-march=armv5,\
+  $(subst -mcpu=cortex-a15,-march=armv7-a,\
+  $(1))))
+endef
diff --git a/core/clang/config.mk b/core/clang/config.mk
new file mode 100644
index 0000000..d134a8d
--- /dev/null
+++ b/core/clang/config.mk
@@ -0,0 +1,60 @@
+
+CLANG := $(HOST_OUT_EXECUTABLES)/clang$(HOST_EXECUTABLE_SUFFIX)
+CLANG_CXX := $(HOST_OUT_EXECUTABLES)/clang++$(HOST_EXECUTABLE_SUFFIX)
+LLVM_AS := $(HOST_OUT_EXECUTABLES)/llvm-as$(HOST_EXECUTABLE_SUFFIX)
+LLVM_LINK := $(HOST_OUT_EXECUTABLES)/llvm-link$(HOST_EXECUTABLE_SUFFIX)
+
+# Clang flags for all host or target rules
+CLANG_CONFIG_EXTRA_ASFLAGS :=
+CLANG_CONFIG_EXTRA_CFLAGS :=
+CLANG_CONFIG_EXTRA_CPPFLAGS :=
+CLANG_CONFIG_EXTRA_LDFLAGS :=
+
+CLANG_CONFIG_EXTRA_CFLAGS := \
+  -D__compiler_offsetof=__builtin_offsetof
+
+CLANG_CONFIG_UNKNOWN_CFLAGS := \
+  -funswitch-loops \
+  -Wno-psabi \
+  -Wno-unused-but-set-variable \
+  -Wno-unused-but-set-parameter
+
+# Clang flags for all host rules
+CLANG_CONFIG_HOST_EXTRA_ASFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_CFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_CPPFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_LDFLAGS :=
+
+# Clang flags for all target rules
+CLANG_CONFIG_TARGET_EXTRA_ASFLAGS :=
+CLANG_CONFIG_TARGET_EXTRA_CFLAGS := -nostdlibinc
+CLANG_CONFIG_TARGET_EXTRA_CPPFLAGS := -nostdlibinc
+CLANG_CONFIG_TARGET_EXTRA_LDFLAGS :=
+
+# HOST config
+include $(BUILD_SYSTEM)/clang/HOST_$(HOST_ARCH).mk
+
+# TARGET config
+clang_2nd_arch_prefix :=
+include $(BUILD_SYSTEM)/clang/TARGET_$(TARGET_ARCH).mk
+
+# TARGET_2ND_ARCH config
+ifdef TARGET_2ND_ARCH
+clang_2nd_arch_prefix := $(TARGET_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/clang/TARGET_$(TARGET_2ND_ARCH).mk
+endif
+
+
+# Clang compiler-specific libc headers
+CLANG_CONFIG_EXTRA_HOST_C_INCLUDES := external/clang/lib/include
+CLANG_CONFIG_EXTRA_TARGET_C_INCLUDES := external/clang/lib/include $(TARGET_OUT_HEADERS)/clang
+
+# Address sanitizer clang config
+ADDRESS_SANITIZER_CONFIG_EXTRA_CFLAGS := -fsanitize=address
+ADDRESS_SANITIZER_CONFIG_EXTRA_LDFLAGS := -Wl,-u,__asan_preinit
+ADDRESS_SANITIZER_CONFIG_EXTRA_SHARED_LIBRARIES := libdl libasan_preload
+ADDRESS_SANITIZER_CONFIG_EXTRA_STATIC_LIBRARIES := libasan
+
+# This allows us to use the superset of functionality that compiler-rt
+# provides to Clang (for supporting features like -ftrapv).
+COMPILER_RT_CONFIG_EXTRA_STATIC_LIBRARIES := libcompiler_rt-extras
diff --git a/core/clang/mips.mk b/core/clang/mips.mk
new file mode 100644
index 0000000..cef7823
--- /dev/null
+++ b/core/clang/mips.mk
@@ -0,0 +1,28 @@
+# Clang flags for mips arch, target or host.
+
+CLANG_CONFIG_mips_EXTRA_ASFLAGS :=
+CLANG_CONFIG_mips_EXTRA_CFLAGS :=
+CLANG_CONFIG_mips_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_mips_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -EL \
+  -mips32 \
+  -mips32r2 \
+  -mhard-float \
+  -fno-strict-volatile-bitfields \
+  -fgcse-after-reload \
+  -frerun-cse-after-loop \
+  -frename-registers \
+  -march=mips32r2 \
+  -mtune=mips32r2 \
+  -march=mips32 \
+  -mtune=mips32 \
+  -msynci \
+  -mno-fused-madd
+
+# We don't have any mips flags to substitute yet.
+define subst-clang-incompatible-mips-flags
+  $(1)
+endef
diff --git a/core/clang/mips64.mk b/core/clang/mips64.mk
new file mode 100644
index 0000000..9d1117b
--- /dev/null
+++ b/core/clang/mips64.mk
@@ -0,0 +1,30 @@
+# Clang flags for mips64 arch, target or host.
+
+$(warning Untested mips64 clang flags, fix me!)
+
+CLANG_CONFIG_mips64_EXTRA_ASFLAGS :=
+CLANG_CONFIG_mips64_EXTRA_CFLAGS :=
+CLANG_CONFIG_mips64_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_mips64_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -EL \
+  -mips32 \
+  -mips32r2 \
+  -mhard-float \
+  -fno-strict-volatile-bitfields \
+  -fgcse-after-reload \
+  -frerun-cse-after-loop \
+  -frename-registers \
+  -march=mips32r2 \
+  -mtune=mips32r2 \
+  -march=mips32 \
+  -mtune=mips32 \
+  -msynci \
+  -mno-fused-madd
+
+# We don't have any mips64 flags to substitute yet.
+define subst-clang-incompatible-mips64-flags
+  $(1)
+endef
diff --git a/core/clang/x86.mk b/core/clang/x86.mk
new file mode 100644
index 0000000..69c3fb2
--- /dev/null
+++ b/core/clang/x86.mk
@@ -0,0 +1,19 @@
+# Clang flags for x86 arch, target or host.
+
+CLANG_CONFIG_x86_EXTRA_ASFLAGS := \
+  -msse3
+CLANG_CONFIG_x86_EXTRA_CFLAGS :=
+CLANG_CONFIG_x86_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_x86_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -finline-limit=300 \
+  -fno-inline-functions-called-once \
+  -mfpmath=sse \
+  -mbionic
+
+# We don't have any x86 flags to substitute yet.
+define subst-clang-incompatible-x86-flags
+  $(1)
+endef
diff --git a/core/clang/x86_64.mk b/core/clang/x86_64.mk
new file mode 100644
index 0000000..cba10d4
--- /dev/null
+++ b/core/clang/x86_64.mk
@@ -0,0 +1,18 @@
+# Clang flags for x86_64 arch, target or host.
+
+CLANG_CONFIG_x86_64_EXTRA_ASFLAGS :=
+CLANG_CONFIG_x86_64_EXTRA_CFLAGS :=
+CLANG_CONFIG_x86_64_EXTRA_LDFLAGS :=
+
+# Include common unknown flags
+CLANG_CONFIG_x86_64_UNKNOWN_CFLAGS := \
+  $(CLANG_CONFIG_UNKNOWN_CFLAGS) \
+  -finline-limit=300 \
+  -fno-inline-functions-called-once \
+  -mfpmath=sse \
+  -mbionic
+
+# We don't have any x86_64 flags to substitute yet.
+define subst-clang-incompatible-x86_64-flags
+  $(1)
+endef