Android.mk

#projectconfig library

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE_TAGS := optional

LOCAL_MODULE := projectconfig

LOCAL_MODULE_CLASS := JAVA_LIBRARIES

JAVAOPTFILEPATH := $(call local-intermediates-dir)
JAVAOPTFILE := $(JAVAOPTFILEPATH)/ProjectConfig.java

FEATUREOPTION_PATH := $(LOCAL_PATH)

$(JAVAOPTFILE): $(FEATUREOPTION_PATH)/javaoptgen.pl $(FEATUREOPTION_PATH)/DefaultConfig.pm device/reallytek/$(TARGET_DEVICE)/ProjectConfig.mk

$(hide) echo gen $@ ...
$(hide) perl $(FEATUREOPTION_PATH)/javaoptgen.pl $(FEATUREOPTION_PATH)/DefaultConfig.pm device/reallytek/$(TARGET_DEVICE)/ProjectConfig.mk $(JAVAOPTFILEPATH)

ALLJAVAOPTFILES := $(JAVAOPTFILE)

LOCAL_GENERATED_SOURCES += $(JAVAOPTFILE)

# Always use the latest prebuilt Android library.
LOCAL_SDK_VERSION := 19

include $(BUILD_JAVA_LIBRARY)

LOCAL_PATH:= $(call my-dir)

my-dir由编译系统提供，返回的是文件的当前路径

include $(CLEAR_VARS)

$ ( CLEAR _ VARS )指的是clear_vars.mk，脚本会清空所有LOCAL_xxx的变量，不影响后面这些变量的使用，除了LOCAL_PATH。我的理解是执行此.mk文件之前将上一次的.mk变量清空。

LOCAL_MODULE_TAGS := optional

取值范围有user debug eng tests optional等，optional表示该模块在所有版本下都编译

LOCAL_MODULE := projectconfig

生成的模块名，=$(LOCAL_PACKAGE_NAME)，

LOCAL_MODULE_CLASS := JAVA_LIBRARIES

指定编译之后放置的位置

include $(BUILD_JAVA_LIBRARY)

引入编译成可执行文件的规则