Support host multilib build

This change basically ported our target multilib to the host side.
It supports 2 host build modes: x86 and x86_64 multilib build.
For now you need to set "BUILD_HOST_64bit=true" to switch to x86_64
multilib build. Later we'll default to x86_64 build and have a flag
to force 32-bit only build, which may be needed by SDK build.

In host module definition, like in target ones, you can use the
following
LOCAL variables to set up multilib configuration:
LOCAL_MULTILIB: can be "both", "first", "32" or "64".
It also supports the same set of arch or 32-vs-64 specific LOCAL
variables.
By default, it builds only for the first arch.

To keep path compatibility, in x86_64 build files are still output to
out/host/linux-x86; Both 32-bit and 64-bit executables are in
out/host/linux-86/bin;
In x86_64 build 32-bit shared libraries are installed to
out/host/linux-x86/lib32
and 64-bit shared libraries are installed to out/host/linux-x86/lib;
32-bit object files are output to out/host/linux-x86/obj32 and 64-bit
object files
are output to out/host/linux-x86/obj.

Bug: 13751317
Change-Id: I6044f83b7db369a33e05209e8c588eb6dc83409f

1 files changed, 39 insertions, 25 deletions

diff --git a/core/host_executable.mk b/core/host_executable.mk
index ffb35d2..874bf87 100644
--- a/core/host_executable.mk
+++ b/core/host_executable.mk
@@ -1,33 +1,47 @@
-###########################################################
-## Standard rules for building an executable file.
-##
-## Additional inputs from base_rules.make:
-## None.
-###########################################################
-
-LOCAL_IS_HOST_MODULE := true
-ifeq ($(strip $(LOCAL_MODULE_CLASS)),)
-LOCAL_MODULE_CLASS := EXECUTABLES
-endif
-ifeq ($(strip $(LOCAL_MODULE_SUFFIX)),)
-LOCAL_MODULE_SUFFIX := $(HOST_EXECUTABLE_SUFFIX)
-endif
 
-$(call host-executable-hook)
+my_prefix := HOST_
+include $(BUILD_SYSTEM)/multilib.mk
+
+ifndef my_module_multilib
+# By default we only build host module for the first arch.
+my_module_multilib := first
+endif
 
-skip_build_from_source :=
-ifdef LOCAL_PREBUILT_MODULE_FILE
-ifeq (,$(call if-build-from-source,$(LOCAL_MODULE),$(LOCAL_PATH)))
-include $(BUILD_SYSTEM)/prebuilt_internal.mk
-skip_build_from_source := true
+ifeq ($(my_module_multilib),both)
+ifeq ($(LOCAL_MODULE_PATH_32)$(LOCAL_MODULE_STEM_32),)
+$(error $(LOCAL_PATH): LOCAL_MODULE_STEM_32 or LOCAL_MODULE_PATH_32 is required for LOCAL_MULTILIB := both for module $(LOCAL_MODULE))
 endif
+ifeq ($(LOCAL_MODULE_PATH_64)$(LOCAL_MODULE_STEM_64),)
+$(error $(LOCAL_PATH): LOCAL_MODULE_STEM_64 or LOCAL_MODULE_PATH_64 is required for LOCAL_MULTILIB := both for module $(LOCAL_MODULE))
 endif
+else #!LOCAL_MULTILIB == both
+LOCAL_NO_2ND_ARCH_MODULE_SUFFIX := true
+endif
+
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+include $(BUILD_SYSTEM)/module_arch_supported.mk
 
-ifndef skip_build_from_source
+ifeq ($(my_module_arch_supported),true)
+include $(BUILD_SYSTEM)/host_executable_internal.mk
+endif
 
-include $(BUILD_SYSTEM)/binary.mk
+ifdef HOST_2ND_ARCH
+LOCAL_2ND_ARCH_VAR_PREFIX := $(HOST_2ND_ARCH_VAR_PREFIX)
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+ifeq ($(my_module_arch_supported),true)
+# Build for HOST_2ND_ARCH
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_MODULE_STEM :=
+LOCAL_BUILT_MODULE_STEM :=
+LOCAL_INSTALLED_MODULE_STEM :=
+LOCAL_INTERMEDIATE_TARGETS :=
 
-$(LOCAL_BUILT_MODULE): $(all_objects) $(all_libraries)
-	$(transform-host-o-to-executable)
+include $(BUILD_SYSTEM)/host_executable_internal.mk
+endif
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+endif  # HOST_2ND_ARCH
 
-endif  # skip_build_from_source
+LOCAL_NO_2ND_ARCH_MODULE_SUFFIX :=
+my_module_arch_supported :=