Android.bp 编译java库和C库实例

利用Android.bp来编译so库

在SimpleHook模块中，我们使用了以下构建脚本来建议Android.bp

cc_library {
 
    name："libsecAI",
    host_supported: true,
    
    shared_libs:[
        "libnativehelper",
        "libart",
        "liblog",
    ],
    
    local_include_dirs:[
        "include",
    ],
    
    arch:{
        arm: {
            srcs: [
                "AIHook.cpp",
                "HookPage.cpp",
            ],
        },
        arm64:{
            srcs: [
                    "AIHook.cpp",
                    "HookPage.cpp",
                ],
        },  
    },
    
    cppflags：[
        "-DART_STACK_OVERFLOW_GAP_arm=8912",
        "-DART_STACK_OVERFLOW_GAP_arm64=8912",
        "-DART_STACK_OVERFLOW_GAP_mips=16384",
        "-DART_STACK_OVERFLOW_GAP_mips64=16384",
        "-DART_STACK_OVERFLOW_GAP_x86=16384",
        "-DART_STACK_OVERFLOW_GAP_x86_64=20480",
        "-DIMT_SIZE=43",
    ],
    cpp_std:"c++17",

}

可以看出，Android.bp文件的语法与json文件的形式很类似。这里cc_library是用来生成native库的(so包)，常用的属性：

• name： 指定了生成的lib包的名字
• host_supported：当该模块依赖的某个模块中存在该属性，则依赖它的模块都需要配置该属性
• local_include_dirs：项目内的头文件目录依赖，这里是相对路径
• cppflag：编译的flag选项，示例中定义了一些工程依赖的宏的定义
• cpp_std: 指定了编译器依赖的语言编译标准
• arch: 用来指定需要的目标编译平台，诸如arm， arm64，x86等，在srcs中指定需要依赖的源码文件（以相对文件的形式给出）
• srcs：常见的还可以直接在最外层用srcs属性配置工程源码文件
• include_dirs: 指定依赖的头文件，这里的头文件可以为模块外的头文件，以相对整个Android工程路径给出。
• export_include_dirs: 是否将头文件导出；这使得依赖该模块的模块无需再引用依赖模块的头文件目录。

利用Android.bp来编译Java库

来看下framework模块的bp文件

java_library {
    name: "framework",

    srcs: [
        // From build/make/core/pathmap.mk FRAMEWORK_BASE_SUBDIRS
        "core/java/**/*.java",
        "graphics/java/**/*.java",
        "location/java/**/*.java",
        "lowpan/java/**/*.java",
      .....

        ":framework-javastream-protos",

        "core/java/android/accessibilityservice/IAccessibilityServiceConnection.aidl",
        "core/java/android/accessibilityservice/IAccessibilityServiceClient.aidl",
       
        "media/java/android/media/session/ISessionControllerCallback.aidl",
       ......

        ":framework-statslog-gen",
    ],

    aidl: {
        export_include_dirs: [
            // From build/make/core/pathmap.mk FRAMEWORK_BASE_SUBDIRS
            "core/java",
            "graphics/java",
            "location/java",
            "lowpan/java",
            "media/java",
            "media/mca/effect/java",
            "media/mca/filterfw/java",
            "media/mca/filterpacks/java",
            "drm/java",
            "opengl/java",
            "sax/java",
            "telecomm/java",
            "telephony/java",
            "wifi/java",
            "keystore/java",
            "rs/java",
        ],

        include_dirs: [
            "system/update_engine/binder_bindings",     
            "system/bt/binder",
            "system/security/keystore/binder",
        ],
    },

    exclude_srcs: [
        // See comment on framework-atb-backward-compatibility module below
        "core/java/android/content/pm/AndroidTestBaseUpdater.java",
        // See comment on framework-oahl-backward-compatibility module below
        "core/java/android/content/pm/OrgApacheHttpLegacyUpdater.java",
    ],

    no_framework_libs: true,
    libs: [
        "conscrypt",
        "okhttp",
        "bouncycastle",
        "ext",
    ],

    static_libs: [
        "framework-protos",
        "android.hidl.base-V1.0-java",
        "android.hardware.cas-V1.0-java",     
    ],

    // Loaded with System.loadLibrary by android.view.textclassifier
    required: [
        "libtextclassifier",
        "libmedia2_jni",
    ],

    javac_shard_size: 150,

    dxflags: [
        "--core-library",
        "--multi-dex",
    ],
}

首先java_library说明了编译的是java库，另外还可能有java_library_static，file_group等属性,这里面有好多属性，我们重点关注几个选项。

• name：指定了模块名
• static_libs:指定了依赖的静态库（将被打入到jar中）
• libs: 共享库
• srcs：指定模块中含有的java代码，这里也可以指定aidl文件。这里通过 "core/java/**/*.java",这种写法来覆盖某个路径下的所有java文件
• aidl： 一般我们会在这里面指定aidl文件相对路径