Unify target and host Java compilation

This changes tries to reconcile drift between
transform-java-to-classes.jar which is used to build java for the
target with transform-host-java-to-package which is used for the
host. Several packages such as libcore are built both ways and the
drift between these rules was making it hard to make common changes to
things such as warning options.

The new compile-javac definition tries to include as much as possible
from the two previous definitions. Some conflicts it sorts out:
- hardwired -g vs PRIVATE_JAVAC_DEBUG_FLAGS
- consistent order of arguments
- moving PRIVATE_JAVAC_FLAGS to end to allow override of arguments
- xlint_unchecked is always conditional based on LOCAL_WARNINGS_ENABLE

Now what differs between the two is clear in the
transform-java-to-classes and transform-host-java-to-package
definitions. Notable differences:
- the target case supplies a bootclasspath while the host case does not.
- .class files are cleaned up after jaring in the target case,
  but in the cost case they are left for the sake of the vm-tests target
  which expects them to be present. That should probably be fixed in the future.
- PRIVATE_EXTRA_JAR_ARGS used to package resources into the jar only
  happens for the host. Its handled by add-java-resources-to-package for the
  target after dxing.

Change-Id: I2fb28f688fbb632102ca63448c2ac911db0477ae

core/definitions.mk

@@ -1402,35 +1402,48 @@ define unzip-jar-files
   done
 endef
 
-# below we write the list of java files to java-source-list to avoid argument
-# list length problems with Cygwin we filter out duplicate java file names
-# because eclipse's compiler doesn't like them.
-define transform-java-to-classes.jar
-@echo "target Java: $(PRIVATE_MODULE) ($(PRIVATE_CLASS_INTERMEDIATES_DIR))"
+# Common definition to invoke javac on the host and target.
+#
+# Some historical notes:
+# - below we write the list of java files to java-source-list to avoid argument
+#   list length problems with Cygwin
+# - we filter out duplicate java file names because eclipse's compiler
+#   doesn't like them.
+#
+# $(1): javac
+# $(2): bootclasspath
+define compile-java
 $(hide) rm -f $@
 $(hide) rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR)
+$(hide) mkdir -p $(dir $@)
 $(hide) mkdir -p $(PRIVATE_CLASS_INTERMEDIATES_DIR)
-$(call unzip-jar-files,$(PRIVATE_STATIC_JAVA_LIBRARIES), \
-    $(PRIVATE_CLASS_INTERMEDIATES_DIR))
+$(call unzip-jar-files,$(PRIVATE_STATIC_JAVA_LIBRARIES),$(PRIVATE_CLASS_INTERMEDIATES_DIR))
 $(call dump-words-to-file,$(PRIVATE_JAVA_SOURCES),$(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list)
 $(hide) if [ -d "$(PRIVATE_SOURCE_INTERMEDIATES_DIR)" ]; then \
 	    find $(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name '*.java' >> $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list; \
 fi
-$(hide) tr ' ' '\n' < $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list \
-    | sort -u > $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list-uniq
-$(hide) $(TARGET_JAVAC) -encoding ascii $(PRIVATE_BOOTCLASSPATH) \
+$(hide) tr ' ' '\n' < $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))java-source-list \
+    | sort -u > $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))java-source-list-uniq
+$(hide) $(1) -encoding ascii \
+    $(strip $(PRIVATE_JAVAC_DEBUG_FLAGS)) \
+    $(if $(findstring true,$(LOCAL_WARNINGS_ENABLE)),$(xlint_unchecked),) \
+    $(2) \
     $(addprefix -classpath ,$(strip \
         $(call normalize-path-list,$(PRIVATE_ALL_JAVA_LIBRARIES)))) \
-    $(PRIVATE_JAVACFLAGS) $(strip $(PRIVATE_JAVAC_DEBUG_FLAGS)) \
-	$(if $(findstring true,$(LOCAL_WARNINGS_ENABLE)),$(xlint_unchecked),) \
+    $(if $(findstring true,$(LOCAL_WARNINGS_ENABLE)),$(xlint_unchecked),) \
     -extdirs "" -d $(PRIVATE_CLASS_INTERMEDIATES_DIR) \
-    \@$(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list-uniq \
+    $(PRIVATE_JAVACFLAGS) \
+    \@$(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))java-source-list-uniq \
     || ( rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR) ; exit 41 )
 $(hide) rm -f $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list
 $(hide) rm -f $(dir $(PRIVATE_CLASS_INTERMEDIATES_DIR))/java-source-list-uniq
-$(hide) mkdir -p $(dir $@)
 $(hide) jar $(if $(strip $(PRIVATE_JAR_MANIFEST)),-cfm,-cf) \
     $@ $(PRIVATE_JAR_MANIFEST) -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) .
+endef
+
+define transform-java-to-classes.jar
+@echo "target Java: $(PRIVATE_MODULE) ($(PRIVATE_CLASS_INTERMEDIATES_DIR))"
+$(call compile-java,$(TARGET_JAVAC),$(PRIVATE_BOOTCLASSPATH))
 $(hide) rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR)
 endef
 
@@ -1553,31 +1566,12 @@ endef
 # new prebuilt rules to work, we should change this to copy the
 # resources to the out directory and then copy the resources.
 
-# Note: not using aapt tool for this because we aren't making
-# an android package for the host.
+# Note: we intentionally don't clean PRIVATE_CLASS_INTERMEDIATES_DIR
+# in transform-java-to-classes for the sake of vm-tests.
 define transform-host-java-to-package
 @echo "host Java: $(PRIVATE_MODULE) ($(PRIVATE_CLASS_INTERMEDIATES_DIR))"
-@rm -f $@
-@rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR)
-@mkdir -p $(dir $@)
-@mkdir -p $(PRIVATE_CLASS_INTERMEDIATES_DIR)
-$(call unzip-jar-files,$(PRIVATE_STATIC_JAVA_LIBRARIES), \
-    $(PRIVATE_CLASS_INTERMEDIATES_DIR))
-$(call dump-words-to-file,$(sort\
-	$(PRIVATE_JAVA_SOURCES)),\
-	$(PRIVATE_INTERMEDIATES_DIR)/java-source-list-uniq)
-$(hide) $(HOST_JAVAC) -encoding ascii -g \
-	$(PRIVATE_JAVACFLAGS) $(xlint_unchecked) \
-	$(addprefix -classpath ,$(strip \
-		$(call normalize-path-list,$(PRIVATE_ALL_JAVA_LIBRARIES)))) \
-	-extdirs "" -d $(PRIVATE_CLASS_INTERMEDIATES_DIR)\
-        \@$(PRIVATE_INTERMEDIATES_DIR)/java-source-list-uniq || \
-	( rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR) ; exit 41 )
-$(hide) rm -f $(PRIVATE_INTERMEDIATES_DIR)/java-source-list
-$(hide) rm -f $(PRIVATE_INTERMEDIATES_DIR)/java-source-list-uniq
-$(hide) jar $(if $(strip $(PRIVATE_JAR_MANIFEST)),-cfm,-cf) \
-    $@ $(PRIVATE_JAR_MANIFEST) $(PRIVATE_EXTRA_JAR_ARGS) \
-    -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) .
+$(call compile-java,$(HOST_JAVAC),)
+$(hide) if [ ! -z "$(PRIVATE_EXTRA_JAR_ARGS)" ]; then jar uf $@ $(PRIVATE_EXTRA_JAR_ARGS); fi
 endef
 
 ###########################################################