Allow forcing AAPT2 on

Building with FORCE_AAPT2=true will turn on AAPT2 for all modules
unless they set LOCAL_USE_AAPT2 := false.  The build system will
attempt to rewrite common AAPT patterns into AAPT2 patterns,
including removing --extra-packages for support library packages,
removing LOCAL_RESOURCE_DIR point to support library resources,
adding a default empty manifest file if it doesn't exist, and
converting LOCAL_STATIC_JAVA_AAR_LIBRARIES to
LOCAL_STATIC_ANDROID_LIBRARIES.

Bug: 79481102
Test: m checkbuild
Change-Id: I8d9d55fe4d5d5c965c64b0407efe74e0afc35c3a
diff --git a/core/force_aapt2.mk b/core/force_aapt2.mk
new file mode 100644
index 0000000..655ccf5
--- /dev/null
+++ b/core/force_aapt2.mk
@@ -0,0 +1,63 @@
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Including this makefile will force AAPT2 on if FORCE_AAPT2==true,
+# rewriting some properties to convert standard AAPT usage to AAPT2.
+
+ifeq ($(FORCE_AAPT2),true)
+  ifneq ($(LOCAL_USE_AAPT2),true)
+    # Force AAPT2 on
+    LOCAL_USE_AAPT2 := true
+    # Move LOCAL_STATIC_JAVA_AAR_LIBRARIES to LOCAL_STATIC_ANDROID_LIBRARIES
+    LOCAL_STATIC_ANDROID_LIBRARIES := $(strip $(LOCAL_STATIC_ANDROID_LIBRARIES) $(LOCAL_STATIC_JAVA_AAR_LIBRARIES))
+    LOCAL_STATIC_JAVA_AAR_LIBRARIES :=
+    # Filter out support library resources
+    LOCAL_RESOURCE_DIR := $(filter-out \
+      prebuilts/sdk/current/% \
+      frameworks/support/%,\
+        $(LOCAL_RESOURCE_DIR))
+    # Filter out unnecessary aapt flags
+    LOCAL_AAPT_FLAGS := $(subst --extra-packages=,--extra-packages$(space), \
+      $(filter-out \
+        --extra-packages=android.support.% \
+        --extra-packages=androidx.% \
+        --auto-add-overlay,\
+          $(subst --extra-packages$(space),--extra-packages=,$(LOCAL_AAPT_FLAGS))))
+
+    # AAPT2 is pickier about missing resources.  Support library may have references to resources
+    # added in current, so always treat LOCAL_SDK_VERSION as LOCAL_SDK_RES_VERSION := current.
+    ifdef LOCAL_SDK_VERSION
+      LOCAL_SDK_RES_VERSION := current
+    endif
+
+    ifeq (,$(strip $(LOCAL_MANIFEST_FILE)$(LOCAL_FULL_MANIFEST_FILE)))
+      ifeq (,$(wildcard $(LOCAL_PATH)/AndroidManifest.xml))
+        # work around missing manifests by creating a default one
+        $(call pretty-warning, Missing manifest file)
+        LOCAL_FULL_MANIFEST_FILE := $(call local-intermediates-dir,COMMON)/DefaultManifest.xml
+        $(call create-default-manifest-file,$(LOCAL_FULL_MANIFEST_FILE))
+      endif
+    endif
+  endif
+endif
+
+ifneq ($(LOCAL_USE_AAPT2),true)
+  ifneq ($(LOCAL_USE_AAPT2),false)
+    ifneq ($(LOCAL_USE_AAPT2),)
+      $(call pretty-error,Invalid value for LOCAL_USE_AAPT2: "$(LOCAL_USE_AAPT2)")
+    endif
+  endif
+endif