android - Gradle:独立于 SDK 构建目标更改 NDK 构建目标

Question

过去我在 NDK 项目中使用 eclipse，Android.mk 文件非常适合用 API 级别 9 编译 NDK，同时让应用程序 (SDK) 在 API 级别 22 上编译。但似乎这是不可能的当使用带有 Android Studio 1.3 RC1 的实验性 Gradle 构建系统 (2.5) 时。

如何才能在 API 级别 9 上仅编译 NDK？

我的典型 Android.mk 文件如下所示:

APP_PLATFORM := android-9
APP_STL := stlport_static
APP_ABI := all

# Enable c++11 extentions in source code
APP_CPPFLAGS += -std=c++11

#Enable optimalization in release mode
APP_OPTIM := release

我的新 gradle 文件如下所示:

apply plugin: 'com.android.model.application'

model {
    android {
        compileSdkVersion = 22
        buildToolsVersion = "23.0.0 rc3"

        defaultConfig.with {
            applicationId = "com.example"
            minSdkVersion.apiLevel = 9
            targetSdkVersion.apiLevel = 22
            versionCode = 1
            versionName = "1.0"
        }
    }

    android.ndk {
        moduleName = "NativeLibrary"
        cppFlags   += "-I${file("src/main/jni/some_folder")}".toString()
        cppFlags   += "-std=c++11"

        //What should be added here to compile the NDK on API 9???

        CFlags += "-DNDEBUG"
        CFlags += "-fvisibility=hidden"
        cppFlags += "-fvisibility=hidden"

        ldLibs     += ["log"]
        stl         = "stlport_static"
    }

    android.buildTypes {
        release {
            isMinifyEnabled = true
            proguardFiles += file('D:/path/proguard-rules.pro')
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:support-v4:22.2.0'
}

我调查了 Gradle 源代码，似乎 NDK 构建目标被硬编码为与 compileSdkVersion 相同。有没有办法避免或改变这种行为？

NdkCompile.groovy (创建文件)

// target
IAndroidTarget target = getPlugin().loadedSdkParser.target
if (!target.isPlatform()) {
    target = target.parent
}
commands.add("APP_PLATFORM=" + target.hashString())

Sdk.groovy (目标是从 compileSdkVersion 中获取的)

public SdkParser loadParser() {
    checkNotNull(extension, "Extension has not been set")

    // call getParser to ensure it's created.
    SdkParser theParser = getParser()

    if (!isSdkParserInitialized) {
        String target = extension.getCompileSdkVersion()
        if (target == null) {
            throw new IllegalArgumentException("android.compileSdkVersion is missing!")
        }

        FullRevision buildToolsRevision = extension.buildToolsRevision
        if (buildToolsRevision == null) {
            throw new IllegalArgumentException("android.buildToolsVersion is missing!")
        }

        theParser.initParser(target, buildToolsRevision, logger)

        isSdkParserInitialized = true
    }

    return theParser
}

Answer 1

如果您使用的是实验性插件版本 0.4。你可以设置

android.ndk {
   platformVersion = "19"
}