Add split support for AAPT2

AAPT2 allows the declaration of a split path, so that build systems
don't need to guess the auto-generated name.

Construct the split path we want from the configurations passed in to
LOCAL_PACKAGE_SPLITS.

Bug:30445078
Change-Id: I06a4148b283d0c6751751ba116e9482c3a6eae5d

core/aapt2.mk

@@ -1,20 +1,25 @@
 ######################################
 # Compile resource with AAPT2
 # Input variables:
-# full_android_manifest,
+# - full_android_manifest
-# my_res_resources, my_overlay_resources,
+# - my_res_resources
-# my_compiled_res_base_dir, my_res_package,
+# - my_overlay_resources
-# R_file_stamp, proguard_options_file
+# - my_compiled_res_base_dir
-# my_generated_res_dirs: Resources generated during the build process and we have to compile them in a single run of aapt2.
+# - my_res_package
-# my_generated_res_dirs_deps: the dependency to use for my_generated_res_dirs.
+# - R_file_stamp
+# - proguard_options_file
+# - my_generated_res_dirs: Resources generated during the build process and we have to compile them in a single run of aapt2.
+# - my_generated_res_dirs_deps: the dependency to use for my_generated_res_dirs.
+# - my_apk_split_configs: The configurations for which to generate splits.
+# - built_apk_splits: The paths where AAPT should generate the splits.
 #
 # Output variables:
-# my_res_resources_flat, my_overlay_resources_flat,
+# - my_res_resources_flat
-# my_generated_resources_flata
+# - my_overlay_resources_flat
+# - my_generated_resources_flata
 #
 ######################################
 
-
 # Compile all the resource files.
 my_res_resources_flat := \
   $(foreach r, $(my_res_resources),\
@@ -52,6 +57,11 @@ ifneq ($(my_static_library_resources),)
 $(my_res_package): PRIVATE_AAPT_FLAGS += --auto-add-overlay
 endif
 
+ifneq ($(my_apk_split_configs),)
+# Join the Split APK paths with their configuration, separated by a ':'.
+$(my_res_package): PRIVATE_AAPT_FLAGS += $(addprefix --split ,$(join $(built_apk_splits),$(addprefix :,$(my_apk_split_configs))))
+endif
+
 $(my_res_package): PRIVATE_RES_FLAT := $(my_res_resources_flat)
 $(my_res_package): PRIVATE_OVERLAY_FLAT := $(my_static_library_resources) $(my_generated_resources_flata) $(my_overlay_resources_flat)
 $(my_res_package): PRIVATE_SHARED_ANDROID_LIBRARIES := $(my_shared_library_resources)

core/package_internal.mk

@@ -75,10 +75,6 @@ ifeq ($(filter tests, $(LOCAL_MODULE_TAGS)),)
 LOCAL_AAPT_FLAGS := $(LOCAL_AAPT_FLAGS) -z
 endif
 
-ifdef LOCAL_PACKAGE_SPLITS
-LOCAL_AAPT_FLAGS += $(addprefix --split ,$(LOCAL_PACKAGE_SPLITS))
-endif
-
 need_compile_asset :=
 ifeq (,$(LOCAL_ASSET_DIR))
 LOCAL_ASSET_DIR := $(LOCAL_PATH)/assets
@@ -163,6 +159,10 @@ all_resources := $(strip \
        ) \
      ))
 
+ifdef LOCAL_PACKAGE_SPLITS
+LOCAL_AAPT_FLAGS += $(addprefix --split ,$(LOCAL_PACKAGE_SPLITS))
+endif
+
 endif  # LOCAL_USE_AAPT2
 
 ifneq ($(all_resources),)
@@ -171,7 +171,6 @@ endif
 
 all_res_assets := $(strip $(all_assets) $(all_resources))
 
-
 # If no assets or resources were found, clear the directory variables so
 # we don't try to build them.
 ifneq (true,$(need_compile_asset))
@@ -325,6 +324,20 @@ $(built_dex_intermediate) : $(data_binding_stamp)
 endif  # LOCAL_DATA_BINDING
 
 ifeq ($(need_compile_res),true)
+
+###############################
+## APK splits
+built_apk_splits :=
+installed_apk_splits :=
+my_apk_split_configs :=
+
+ifdef LOCAL_PACKAGE_SPLITS
+my_apk_split_configs := $(LOCAL_PACKAGE_SPLITS)
+my_split_suffixes := $(subst $(comma),_,$(my_apk_split_configs))
+built_apk_splits := $(foreach s,$(my_split_suffixes),$(built_module_path)/package_$(s).apk)
+installed_apk_splits := $(foreach s,$(my_split_suffixes),$(my_module_path)/$(LOCAL_MODULE)_$(s).apk)
+endif
+
 ifdef LOCAL_USE_AAPT2
 my_compiled_res_base_dir := $(intermediates)/flat-res
 my_generated_res_dirs := $(rs_generated_res_dir)
@@ -548,12 +561,6 @@ endif
 ###############################
 ## APK splits
 ifdef LOCAL_PACKAGE_SPLITS
-# LOCAL_PACKAGE_SPLITS is a list of resource labels.
-# aapt will convert comma inside resource lable to underscore in the file names.
-my_split_suffixes := $(subst $(comma),_,$(LOCAL_PACKAGE_SPLITS))
-built_apk_splits := $(foreach s,$(my_split_suffixes),$(built_module_path)/package_$(s).apk)
-installed_apk_splits := $(foreach s,$(my_split_suffixes),$(my_module_path)/$(LOCAL_MODULE)_$(s).apk)
-
 # The splits should have been built in the same command building the base apk.
 # This rule just runs signing.
 # Note that we explicily check the existence of the split apk and remove the