diff --git a/core/Makefile b/core/Makefile
index 5bc6322..4ef0d89 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -31,12 +31,13 @@
     $(if $(filter $(unique_product_copy_files_pairs),$(cf)),,\
         $(eval unique_product_copy_files_pairs += $(cf))))
 unique_product_copy_files_destinations :=
+product_copy_files_ignored :=
 $(foreach cf,$(unique_product_copy_files_pairs), \
     $(eval _src := $(call word-colon,1,$(cf))) \
     $(eval _dest := $(call word-colon,2,$(cf))) \
     $(call check-product-copy-files,$(cf)) \
     $(if $(filter $(unique_product_copy_files_destinations),$(_dest)), \
-        $(info PRODUCT_COPY_FILES $(cf) ignored.), \
+        $(eval product_copy_files_ignored += $(cf)), \
         $(eval _fulldest := $(call append-path,$(PRODUCT_OUT),$(_dest))) \
         $(if $(filter %.xml,$(_dest)),\
             $(eval $(call copy-xml-file-checked,$(_src),$(_fulldest))),\
@@ -45,6 +46,14 @@
                 $(eval $(call copy-one-file,$(_src),$(_fulldest))))) \
         $(eval ALL_DEFAULT_INSTALLED_MODULES += $(_fulldest)) \
         $(eval unique_product_copy_files_destinations += $(_dest))))
+
+# Dump a list of overriden (and ignored PRODUCT_COPY_FILES entries)
+$(file >$(PRODUCT_OUT)/product_copy_files_ignored.txt,$(subst $(space),$(newline),$(strip $(product_copy_files_ignored))))
+ifdef dist_goal
+$(file >$(DIST_DIR)/logs/product_copy_files_ignored.txt,$(subst $(space),$(newline),$(strip $(product_copy_files_ignored))))
+endif
+
+product_copy_files_ignored :=
 unique_product_copy_files_pairs :=
 unique_product_copy_files_destinations :=
 
@@ -1213,15 +1222,15 @@
 
 # $(1): output file
 define build-recoveryimage-target
-  @echo ----- Making recovery image ------
+  # Making recovery image
   $(hide) mkdir -p $(TARGET_RECOVERY_OUT)
   $(hide) mkdir -p $(TARGET_RECOVERY_ROOT_OUT)/etc $(TARGET_RECOVERY_ROOT_OUT)/sdcard $(TARGET_RECOVERY_ROOT_OUT)/tmp
-  @echo Copying baseline ramdisk...
+  # Copying baseline ramdisk...
   # Use rsync because "cp -Rf" fails to overwrite broken symlinks on Mac.
   $(hide) rsync -a --exclude=etc --exclude=sdcard $(IGNORE_RECOVERY_SEPOLICY) $(IGNORE_CACHE_LINK) $(TARGET_ROOT_OUT) $(TARGET_RECOVERY_OUT)
   # Copy adbd from system/bin to recovery/root/sbin
   $(hide) cp -f $(TARGET_OUT_EXECUTABLES)/adbd $(TARGET_RECOVERY_ROOT_OUT)/sbin/adbd
-  @echo Modifying ramdisk contents...
+  # Modifying ramdisk contents...
   $(if $(BOARD_RECOVERY_KERNEL_MODULES), \
     $(call build-image-kernel-modules,$(BOARD_RECOVERY_KERNEL_MODULES),$(TARGET_RECOVERY_ROOT_OUT),,$(call intermediates-dir-for,PACKAGING,depmod_recovery)))
   # Removes $(TARGET_RECOVERY_ROOT_OUT)/init*.rc EXCEPT init.recovery*.rc.
@@ -1273,7 +1282,6 @@
   $(if $(filter true,$(BOARD_USES_RECOVERY_AS_BOOT)), \
     $(hide) $(call assert-max-image-size,$(1),$(BOARD_BOOTIMAGE_PARTITION_SIZE)), \
     $(hide) $(call assert-max-image-size,$(1),$(BOARD_RECOVERYIMAGE_PARTITION_SIZE)))
-  @echo ----- Made recovery image: $(1) --------
 endef
 
 ADBD := $(TARGET_OUT_EXECUTABLES)/adbd
diff --git a/core/aapt2.mk b/core/aapt2.mk
index 8bb2d4b..c582e30 100644
--- a/core/aapt2.mk
+++ b/core/aapt2.mk
@@ -108,3 +108,13 @@
 
 	cp $@ $(PRIVATE_RESOURCE_EXPORT_PACKAGE)
 endif
+
+# Clear inputs only used in this file, so that they're not re-used during the next build
+my_res_resources :=
+my_overlay_resources :=
+my_compiled_res_base_dir :=
+my_asset_dirs :=
+my_full_asset_paths :=
+my_apk_split_configs :=
+my_generated_res_dirs :=
+my_generated_res_dirs_deps :=
diff --git a/core/config.mk b/core/config.mk
index 232f1d0..05fb926 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -546,7 +546,7 @@
   ZIPALIGN := $(prebuilt_sdk_tools_bin)/zipalign
 endif # TARGET_BUILD_APPS || TARGET_BUILD_PDK
 
-R8_COMPAT_PROGUARD_JAR := prebuilts/r8/compatproguard-master.jar
+R8_COMPAT_PROGUARD := $(HOST_OUT_EXECUTABLES)/r8-compat-proguard
 
 ifeq (,$(TARGET_BUILD_APPS))
   # Use RenderScript prebuilts for unbundled builds but not PDK builds
@@ -665,14 +665,28 @@
 
 COLUMN:= column
 
-# Path to tools.jar, or empty if EXPERIMENTAL_USE_OPENJDK9 is set
+ifeq ($(EXPERIMENTAL_USE_OPENJDK9),)
+USE_OPENJDK9 :=
+TARGET_OPENJDK9 :=
+else ifeq ($(EXPERIMENTAL_USE_OPENJDK9),false)
+USE_OPENJDK9 :=
+TARGET_OPENJDK9 :=
+else ifeq ($(EXPERIMENTAL_USE_OPENJDK9),1.8)
+USE_OPENJDK9 := true
+TARGET_OPENJDK9 :=
+else ifeq ($(EXPERIMENTAL_USE_OPENJDK9),true)
+USE_OPENJDK9 := true
+TARGET_OPENJDK9 := true
+endif
+
+# Path to tools.jar, or empty if USE_OPENJDK9 is unset
 HOST_JDK_TOOLS_JAR :=
 # TODO: Remove HOST_JDK_TOOLS_JAR and all references to it once OpenJDK 8
-# toolchains are no longer supported (i.e. when what is now
-# EXPERIMENTAL_USE_OPENJDK9 becomes the standard). http://b/38418220
-ifeq ($(EXPERIMENTAL_USE_OPENJDK9),)
+# toolchains are no longer supported (i.e. when USE_OPENJDK9 is enforced).
+# http://b/38418220
+ifndef USE_OPENJDK9
 HOST_JDK_TOOLS_JAR := $(ANDROID_JAVA_TOOLCHAIN)/../lib/tools.jar
-endif # ifeq ($(EXPERIMENTAL_USE_OPENJDK9),)
+endif # ifndef USE_OPENJDK9
 
 # It's called md5 on Mac OS and md5sum on Linux
 ifeq ($(HOST_OS),darwin)
@@ -709,9 +723,6 @@
 # PRODUCT_FULL_TREBLE
 $(foreach req,$(requirements),$(eval \
     $(req) := $(if $($(req)_OVERRIDE),$($(req)_OVERRIDE),$(PRODUCT_FULL_TREBLE))))
-# If the requirement is false for any reason, then it's not PRODUCT_FULL_TREBLE
-$(foreach req,$(requirements),$(eval \
-    PRODUCT_FULL_TREBLE := $(if $(filter false,$($(req))),false,$(PRODUCT_FULL_TREBLE))))
 
 .KATI_READONLY := \
     $(requirements) \
diff --git a/core/definitions.mk b/core/definitions.mk
index c7799b0..13bd47c 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2381,7 +2381,7 @@
 @rm -rf $(dir $@)/desugar_dumped_classes
 @mkdir $(dir $@)/desugar_dumped_classes
 $(hide) $(JAVA) \
-    $(if $(EXPERIMENTAL_USE_OPENJDK9),--add-opens java.base/java.lang.invoke=ALL-UNNAMED,) \
+    $(if $(USE_OPENJDK9),--add-opens java.base/java.lang.invoke=ALL-UNNAMED,) \
     -Djdk.internal.lambda.dumpProxyClasses=$(abspath $(dir $@))/desugar_dumped_classes \
     -jar $(DESUGAR) \
     $(addprefix --bootclasspath_entry ,$(PRIVATE_BOOTCLASSPATH)) \
@@ -2774,7 +2774,7 @@
 ###########################################################
 ## Commands to call Proguard
 ###########################################################
-ifeq ($(EXPERIMENTAL_USE_OPENJDK9),true)
+ifdef TARGET_OPENJDK9
 define transform-jar-to-proguard
 @echo Skipping Proguard: $<$(PRIVATE_PROGUARD_INJAR_FILTERS) $@
 $(hide) cp '$<' $@
@@ -2795,7 +2795,7 @@
 ###########################################################
 define transform-jar-to-dex-r8
 @echo R8: $@
-$(hide) $(JAVA) -jar $(R8_COMPAT_PROGUARD_JAR) -injars '$<$(PRIVATE_PROGUARD_INJAR_FILTERS)' \
+$(hide) $(R8_COMPAT_PROGUARD) -injars '$<$(PRIVATE_PROGUARD_INJAR_FILTERS)' \
     --min-api $(PRIVATE_MIN_SDK_VERSION) \
     --force-proguard-compatibility --output $(subst classes.dex,,$@) \
     $(PRIVATE_PROGUARD_FLAGS) \
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 45b8af0..2bac984 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -91,8 +91,11 @@
 $(full_target): PRIVATE_SOURCE_PATH := $(call normalize-path-list,$(LOCAL_DROIDDOC_SOURCE_PATH))
 $(full_target): PRIVATE_JAVA_FILES := $(filter %.java,$(full_src_files))
 $(full_target): PRIVATE_JAVA_FILES += $(addprefix $($(my_prefix)OUT_COMMON_INTERMEDIATES)/, $(filter %.java,$(LOCAL_INTERMEDIATE_SOURCES)))
+$(full_target): PRIVATE_SRCJARS := $(LOCAL_SRCJARS)
 $(full_target): PRIVATE_SOURCE_INTERMEDIATES_DIR := $(intermediates.COMMON)/src
+$(full_target): PRIVATE_SRCJAR_INTERMEDIATES_DIR := $(intermediates.COMMON)/srcjars
 $(full_target): PRIVATE_SRC_LIST_FILE := $(intermediates.COMMON)/droiddoc-src-list
+$(full_target): PRIVATE_SRCJAR_LIST_FILE := $(intermediates.COMMON)/droiddoc-srcjar-list
 
 ifneq ($(strip $(LOCAL_ADDITIONAL_JAVA_DIR)),)
 $(full_target): PRIVATE_ADDITIONAL_JAVA_DIR := $(LOCAL_ADDITIONAL_JAVA_DIR)
@@ -173,17 +176,21 @@
         $(droiddoc) \
         $(html_dir_files) \
         $(full_java_libs) \
+        $(EXTRACT_SRCJARS) \
+        $(LOCAL_SRCJARS) \
         $(LOCAL_ADDITIONAL_DEPENDENCIES)
 	@echo Docs droiddoc: $(PRIVATE_OUT_DIR)
 	$(hide) mkdir -p $(dir $@)
-	$(addprefix $(hide) rm -rf ,$(PRIVATE_STUB_OUT_DIR))
+	$(hide) rm -rf $(PRIVATE_STUB_OUT_DIR) $(PRIVATE_SRCJAR_INTERMEDIATES_DIR)
 	$(call prepare-doc-source-list,$(PRIVATE_SRC_LIST_FILE),$(PRIVATE_JAVA_FILES), \
 			$(PRIVATE_SOURCE_INTERMEDIATES_DIR) $(PRIVATE_ADDITIONAL_JAVA_DIR))
+	$(EXTRACT_SRCJARS) $(PRIVATE_SRCJAR_INTERMEDIATES_DIR) $(PRIVATE_SRCJAR_LIST_FILE) $(PRIVATE_SRCJARS)
 	$(hide) ( \
 		$(JAVADOC) \
                 -encoding UTF-8 \
                 -source 1.8 \
                 \@$(PRIVATE_SRC_LIST_FILE) \
+                \@$(PRIVATE_SRCJAR_LIST_FILE) \
                 -J-Xmx1600m \
                 -J-XX:-OmitStackTraceInFastThrow \
                 -XDignore.symbol.file \
@@ -213,7 +220,7 @@
 ##
 ##
 
-ifneq ($(EXPERIMENTAL_USE_OPENJDK9),)
+ifdef USE_OPENJDK9
 # For OpenJDK 9 we use --patch-module to define the core libraries code.
 # TODO(tobiast): Reorganize this when adding proper support for OpenJDK 9
 # modules. Here we treat all code in core libraries as being in java.base
@@ -223,17 +230,19 @@
 # For OpenJDK 8 we can use -bootclasspath to define the core libraries code.
 $(full_target): PRIVATE_BOOTCLASSPATH_ARG := $(addprefix -bootclasspath ,$(PRIVATE_BOOTCLASSPATH))
 endif
-
-$(full_target): $(full_src_files) $(full_java_libs)
+$(full_target): $(full_src_files) $(full_java_libs) $(EXTRACT_SRCJARS) $(LOCAL_SRCJARS) $(LOCAL_ADDITIONAL_DEPENDENCIES)
 	@echo Docs javadoc: $(PRIVATE_OUT_DIR)
 	@mkdir -p $(dir $@)
+	rm -rf $(PRIVATE_SRCJAR_INTERMEDIATES_DIR)
 	$(call prepare-doc-source-list,$(PRIVATE_SRC_LIST_FILE),$(PRIVATE_JAVA_FILES), \
 			$(PRIVATE_SOURCE_INTERMEDIATES_DIR) $(PRIVATE_ADDITIONAL_JAVA_DIR))
+	$(EXTRACT_SRCJARS) $(PRIVATE_SRCJAR_INTERMEDIATES_DIR) $(PRIVATE_SRCJAR_LIST_FILE) $(PRIVATE_SRCJARS)
 	$(hide) ( \
 		$(JAVADOC) \
                 -encoding UTF-8 \
                 $(PRIVATE_DROIDDOC_OPTIONS) \
                 \@$(PRIVATE_SRC_LIST_FILE) \
+                \@$(PRIVATE_SRCJAR_LIST_FILE) \
                 -J-Xmx1024m \
                 -XDignore.symbol.file \
                 -Xdoclint:none \
diff --git a/core/java.mk b/core/java.mk
index 71bed38..9143bc1 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -555,7 +555,9 @@
 
 $(eval $(call copy-one-file,$(full_classes_jarjar_jar),$(full_classes_jar)))
 
-ifeq ($(EXPERIMENTAL_USE_OPENJDK9),true)
+# Temporarily enable --multi-dex until proguard supports v53 class files
+# ( http://b/67673860 ) or we move away from proguard altogether.
+ifdef TARGET_OPENJDK9
 LOCAL_DX_FLAGS := $(filter-out --multi-dex,$(LOCAL_DX_FLAGS)) --multi-dex
 endif
 
@@ -752,7 +754,7 @@
 $(built_dex_intermediate): PRIVATE_PROGUARD_INJAR_FILTERS := $(proguard_injar_filters)
 $(built_dex_intermediate): PRIVATE_EXTRA_INPUT_JAR := $(extra_input_jar)
 $(built_dex_intermediate): PRIVATE_PROGUARD_FLAGS := $(legacy_proguard_flags) $(common_proguard_flags) $(LOCAL_PROGUARD_FLAGS)
-$(built_dex_intermediate) : $(full_classes_proguard_jar) $(extra_input_jar) $(my_support_library_sdk_raise) $(common_proguard_flag_files) $(proguard_flag_files) $(legacy_proguard_lib_deps) $(R8_COMPAT_PROGUARD_JAR)
+$(built_dex_intermediate) : $(full_classes_proguard_jar) $(extra_input_jar) $(my_support_library_sdk_raise) $(common_proguard_flag_files) $(proguard_flag_files) $(legacy_proguard_lib_deps) $(R8_COMPAT_PROGUARD)
 	$(transform-jar-to-dex-r8)
 endif # USE_R8
 endif # LOCAL_PROGUARD_ENABLED
diff --git a/core/java_common.mk b/core/java_common.mk
index 37de700..6ae1415 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -23,8 +23,7 @@
     # TODO(ccross): allow 1.9 for current and unbundled once we have SDK system modules
     LOCAL_JAVA_LANGUAGE_VERSION := 1.8
   else
-    # DEFAULT_JAVA_LANGUAGE_VERSION is 1.8 unless EXPERIMENTAL_USE_OPENJDK9=true
-    # in which case it is 1.9
+    # DEFAULT_JAVA_LANGUAGE_VERSION is 1.8, unless TARGET_OPENJDK9 in which case it is 1.9
     LOCAL_JAVA_LANGUAGE_VERSION := $(DEFAULT_JAVA_LANGUAGE_VERSION)
   endif
 endif
diff --git a/tools/generate-notice-files.py b/tools/generate-notice-files.py
index adbf7c2..b754174 100755
--- a/tools/generate-notice-files.py
+++ b/tools/generate-notice-files.py
@@ -253,15 +253,12 @@
 
     filesets = [sorted(files_with_same_hash[md5]) for md5 in sorted(files_with_same_hash.keys())]
 
-    print "Combining NOTICE files into text"
     combine_notice_files_text(filesets, input_dir, txt_output_file, file_title)
 
     if html_output_file is not None:
-        print "Combining NOTICE files into HTML"
         combine_notice_files_html(filesets, input_dir, html_output_file)
 
     if xml_output_file is not None:
-        print "Combining NOTICE files into XML"
         combine_notice_files_xml(files_with_same_hash, input_dir, xml_output_file)
 
 if __name__ == "__main__":
diff --git a/tools/java-event-log-tags.py b/tools/java-event-log-tags.py
index f364751..37cd712 100755
--- a/tools/java-event-log-tags.py
+++ b/tools/java-event-log-tags.py
@@ -51,30 +51,37 @@
     print >> sys.stderr, "unhandled option %s" % (o,)
     sys.exit(1)
 
-if len(args) != 2:
-  print "need exactly two input files, not %d" % (len(args),)
+if len(args) != 1 and len(args) != 2:
+  print "need one or two input files, not %d" % (len(args),)
   print __doc__
   sys.exit(1)
 
 fn = args[0]
 tagfile = event_log_tags.TagFile(fn)
 
-# Load the merged tag file (which should have numbers assigned for all
-# tags.  Use the numbers from the merged file to fill in any missing
-# numbers from the input file.
-merged_fn = args[1]
-merged_tagfile = event_log_tags.TagFile(merged_fn)
-merged_by_name = dict([(t.tagname, t) for t in merged_tagfile.tags])
-for t in tagfile.tags:
-  if t.tagnum is None:
-    if t.tagname in merged_by_name:
-      t.tagnum = merged_by_name[t.tagname].tagnum
-    else:
-      # We're building something that's not being included in the
-      # product, so its tags don't appear in the merged file.  Assign
-      # them all an arbitrary number so we can emit the java and
-      # compile the (unused) package.
-      t.tagnum = 999999
+if len(args) > 1:
+  # Load the merged tag file (which should have numbers assigned for all
+  # tags.  Use the numbers from the merged file to fill in any missing
+  # numbers from the input file.
+  merged_fn = args[1]
+  merged_tagfile = event_log_tags.TagFile(merged_fn)
+  merged_by_name = dict([(t.tagname, t) for t in merged_tagfile.tags])
+  for t in tagfile.tags:
+    if t.tagnum is None:
+      if t.tagname in merged_by_name:
+        t.tagnum = merged_by_name[t.tagname].tagnum
+      else:
+        # We're building something that's not being included in the
+        # product, so its tags don't appear in the merged file.  Assign
+        # them all an arbitrary number so we can emit the java and
+        # compile the (unused) package.
+        t.tagnum = 999999
+else:
+  # Not using the merged tag file, so all tags must have manually assigned
+  # numbers
+  for t in tagfile.tags:
+    if t.tagnum is None:
+      tagfilef.AddError("tag \"%s\" has no number" % (tagname,), tag.linenum)
 
 if "java_package" not in tagfile.options:
   tagfile.AddError("java_package option not specified", linenum=0)
diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index a388f8a..e11f5a6 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -195,8 +195,9 @@
     else:
       hi = i
 
-  print("Adjusted partition size for verity, partition_size: {},"
-        " verity_size: {}".format(result, verity_size))
+  if OPTIONS.verbose:
+    print("Adjusted partition size for verity, partition_size: {},"
+          " verity_size: {}".format(result, verity_size))
   AdjustPartitionSizeForVerity.results[key] = (result, verity_size)
   return (result, verity_size)
 
@@ -257,7 +258,7 @@
   return True
 
 def Append(target, file_to_append, error_message):
-  print "appending %s to %s" % (file_to_append, target)
+  # appending file_to_append to target
   with open(target, "a") as out_file:
     with open(file_to_append, "r") as input_file:
       for line in input_file:
@@ -535,9 +536,9 @@
 
   try:
     if fs_type.startswith("ext4"):
-      (ext4fs_output, exit_code) = RunCommand(build_command, True)
+      (ext4fs_output, exit_code) = RunCommand(build_command)
     else:
-      (_, exit_code) = RunCommand(build_command, True)
+      (_, exit_code) = RunCommand(build_command)
   finally:
     if in_dir != origin_in:
       # Clean up temporary directories and files.
diff --git a/tools/warn.py b/tools/warn.py
index 44ad368..cc63de4 100755
--- a/tools/warn.py
+++ b/tools/warn.py
@@ -1807,6 +1807,7 @@
      'patterns': [r".*: warning: In file included from .+,"]},
 
     # warnings from clang-tidy
+    group_tidy_warn_pattern('android'),
     group_tidy_warn_pattern('cert'),
     group_tidy_warn_pattern('clang-diagnostic'),
     group_tidy_warn_pattern('cppcoreguidelines'),