Android.mk用法详解

男娘i 2022-01-23 00:23 183阅读 0赞

**一、[Android][].mk介绍**

Android.mk是Android提供的一种makefile文件，用来指定诸如编译生成so库名、引用的头文件目录、需要编译的.c/.cpp文件和.a静态库文件。

它的基本格式如下：

LOCAL_PATH := $(call my-dir)  
    include $(CLEAR_VARS)  
    ................  
    LOCAL_xxx       := xxx  
    LOCAL_MODULE    := hello-jni  
    LOCAL_SRC_FILES := hello-jni.c  
    LOCAL_xxx       := xxx  
    ................  
    include $(BUILD_SHARED_LIBRARY)

**二、Android.mk语法详解**

LOCAL\_PATH := $(call my-dir)   
每个Android.mk文件必须以定义LOCAL\_PATH为开始。它用于在开发tree中查找源文件。宏my-dir 则由Build System提供。返回包含Android.mk的目录路径。

include $(CLEAR\_VARS)   
CLEAR\_VARS 变量由Build System提供。并指向一个指定的GNU Makefile，由它负责清理很多LOCAL\_xxx.  
例如：LOCAL\_MODULE, LOCAL\_SRC\_FILES, LOCAL\_STATIC\_LIBRARIES等等。但不清理LOCAL\_PATH.  
这个清理动作是必须的，因为所有的编译控制文件由同一个GNU Make解析和执行，其变量是全局的。所以清理后才能避免相互影响。

LOCAL\_MODULE    := hello-jni

LOCAL\_MODULE模块必须定义，以表示Android.mk中的每一个模块。名字必须唯一且不包含空格。Build System会自动添加适当的前缀和后缀。例如，foo，要产生动态库，则生成libfoo.so. 但请注意：如果模块名被定为：libfoo.则生成libfoo.so. 不再加前缀

LOCAL\_MODULE\_PATH :=$(TARGET\_ROOT\_OUT) 指定最后生成的模块的目标地址

TARGET\_ROOT\_OUT:根文件系统，路径为out/target/product/generic/root

TARGET\_OUT:system文件系统，路径为out/target/product/generic/system

TARGET\_OUT\_DATA:data文件系统，路径为out/target/product/generic/data

除了上面的这些，NDK还提供了很多其他的TARGET\_XXX\_XXX变量，用于将生成的模块拷贝到输出目录的不同路径

默认是TARGET\_OUT

LOCAL\_SRC\_FILES := hello-jni.c

LOCAL\_SRC\_FILES变量必须包含将要打包如模块的C/C++ 源码。不必列出头文件，build System 会自动帮我们找出依赖文件。缺省的C++源码的扩展名为.cpp. 也可以修改，通过LOCAL\_CPP\_EXTENSION

include $(BUILD\_SHARED\_LIBRARY)   
BUILD\_SHARED\_LIBRARY：是Build System提供的一个变量，指向一个GNU Makefile Script。  
它负责收集自从上次调用 include $(CLEAR\_VARS)  后的所有LOCAL\_XXX信息。并决定编译为什么。

BUILD\_STATIC\_LIBRARY    ：编译为静态库。   
BUILD\_SHARED\_LIBRARY ：编译为动态库   
BUILD\_EXECUTABLE           ：编译为Native C可执行程序

BUILD\_PREBUILT                 ：该模块已经预先编译

NDK还定义了很多其他的BUILD\_XXX\_XXX变量，它们用来指定模块的生成方式。

**三、使用示例**

#编译静态库    
    LOCAL_PATH := $(call my-dir)    
    include $(CLEAR_VARS)    
    LOCAL_MODULE = libhellos    
    LOCAL_CFLAGS = $(L_CFLAGS)    
    LOCAL_SRC_FILES = hellos.c    
    LOCAL_C_INCLUDES = $(INCLUDES)    
    LOCAL_SHARED_LIBRARIES := libcutils    
    LOCAL_COPY_HEADERS_TO := libhellos    
    LOCAL_COPY_HEADERS := hellos.h    
    include $(BUILD_STATIC_LIBRARY)    
        
    #编译动态库    
    LOCAL_PATH := $(call my-dir)    
    include $(CLEAR_VARS)    
    LOCAL_MODULE = libhellod    
    LOCAL_CFLAGS = $(L_CFLAGS)    
    LOCAL_SRC_FILES = hellod.c    
    LOCAL_C_INCLUDES = $(INCLUDES)    
    LOCAL_SHARED_LIBRARIES := libcutils    
    LOCAL_COPY_HEADERS_TO := libhellod    
    LOCAL_COPY_HEADERS := hellod.h    
    include $(BUILD_SHARED_LIBRARY)    
        
    #使用静态库    
    LOCAL_PATH := $(call my-dir)    
    include $(CLEAR_VARS)    
    LOCAL_MODULE := hellos    
    LOCAL_STATIC_LIBRARIES := libhellos    
    LOCAL_SHARED_LIBRARIES :=    
    LOCAL_LDLIBS += -ldl    
    LOCAL_CFLAGS := $(L_CFLAGS)    
    LOCAL_SRC_FILES := mains.c    
    LOCAL_C_INCLUDES := $(INCLUDES)    
    include $(BUILD_EXECUTABLE)    
        
    #使用动态库    
    LOCAL_PATH := $(call my-dir)    
    include $(CLEAR_VARS)    
    LOCAL_MODULE := hellod    
    LOCAL_MODULE_TAGS := debug    
    LOCAL_SHARED_LIBRARIES := libc libcutils libhellod    
    LOCAL_LDLIBS += -ldl    
    LOCAL_CFLAGS := $(L_CFLAGS)    
    LOCAL_SRC_FILES := maind.c    
    LOCAL_C_INCLUDES := $(INCLUDES)    
    include $(BUILD_EXECUTABLE)    
      
      
    #拷贝文件到指定目录  
    LOCAL_PATH := $(call my-dir)  
    include $(CLEAR_VARS)  
    LOCAL_MODULE := bt_vendor.conf  
    LOCAL_MODULE_CLASS := ETC  
    LOCAL_MODULE_PATH := $(TARGET_OUT)/etc/bluetooth  
    LOCAL_MODULE_TAGS := eng  
    LOCAL_SRC_FILES := $(LOCAL_MODULE)  
    include $(BUILD_PREBUILT)  
      
      
    #拷贝动态库到指定目录  
    LOCAL_PATH := $(call my-dir)  
    include $(CLEAR_VARS)  
    #the data or lib you want to copy  
    LOCAL_MODULE := libxxx.so  
    LOCAL_MODULE_CLASS := SHARED_LIBRARIES  
    LOCAL_MODULE_PATH := $(ANDROID_OUT_SHARED_LIBRARIES)  
    LOCAL_SRC_FILES := lib/$(LOCAL_MODULE )  
    OVERRIDE_BUILD_MODULE_PATH := $(TARGET_OUT_INTERMEDIATE_LIBRARIES)  
    include $(BUILD_PREBUILT)

参考文章：

[http://www.cnblogs.com/wainiwann/p/3837936.html][http_www.cnblogs.com_wainiwann_p_3837936.html]

[http://blog.csdn.net/ly131420/article/details/9619269][http_blog.csdn.net_ly131420_article_details_9619269]

[http://blog.csdn.net/mawl2002/article/details/6118522][http_blog.csdn.net_mawl2002_article_details_6118522]

--------------------

本文转载自 [https://www.cnblogs.com/reality-soul/p/6893248.html][https_www.cnblogs.com_reality-soul_p_6893248.html]

[Android]: http://lib.csdn.net/base/android
[http_www.cnblogs.com_wainiwann_p_3837936.html]: http://www.cnblogs.com/wainiwann/p/3837936.html
[http_blog.csdn.net_ly131420_article_details_9619269]: http://blog.csdn.net/ly131420/article/details/9619269
[http_blog.csdn.net_mawl2002_article_details_6118522]: http://blog.csdn.net/mawl2002/article/details/6118522
[https_www.cnblogs.com_reality-soul_p_6893248.html]: https://www.cnblogs.com/reality-soul/p/6893248.html