Android 编译流程解析01-AppPlugin初始化

简介

Android编译由Gradle插件来完成。
在平时开发中，我们都知道，添加以下Gradle插件，我们就可以编译Android项目。

dependencies {         classpath 'com.android.tools.build:gradle:3.0.1'}apply plugin: 'com.android.application' //主项目apply plugin: 'com.android.library' //Library

那我们要如何看到com.android.tools.build:gradle的源码呢?
我们可以在app的gradle引入

compileOnly "com.android.tools.build:gradle:3.0.1"

然后就可以在External Libraries中，看到源码了。
Android 编译流程解析01-AppPlugin初始化_第1张图片
接着，我们来看下com.android.application.properties

implementation-class=com.android.build.gradle.AppPlugin

可以看到，AppPlugin这个类，即com.android.application的入口是AppPlugin

public class AppPlugin extends BasePlugin implements Plugin<Project> {     //...}

我们来看其中的apply方法

@Overridepublic void apply(@NonNull Project project) {         super.apply(project);}

可以看到，其调用了父类BasePlugin，我们来看BasePlugin的apply方法

protected void apply(@NonNull Project project) {      // We run by default in headless mode, so the JVM doesn't steal focus.    System.setProperty("java.awt.headless", "true");    project.getPluginManager().apply(AndroidBasePlugin.class);    checkPluginVersion();    TaskInputHelper.enableBypass();    this.project = project;    this.projectOptions = new ProjectOptions(project);    ExecutionConfigurationUtil.setThreadPoolSize(projectOptions);    checkPathForErrors();    checkModulesForErrors();    PluginInitializer.initialize(project, projectOptions);    ProfilerInitializer.init(project, projectOptions);    //获得threadRecorder    threadRecorder = ThreadRecorder.get();    ProcessProfileWriter.getProject(project.getPath())            .setAndroidPluginVersion(Version.ANDROID_GRADLE_PLUGIN_VERSION)            .setAndroidPlugin(getAnalyticsPluginType())            .setPluginGeneration(GradleBuildProject.PluginGeneration.FIRST);//记录一个方法的耗时，内部会调用configureProject()    threadRecorder.record(            ExecutionType.BASE_PLUGIN_PROJECT_CONFIGURE,            project.getPath(),            null,            this::configureProject);//记录一个方法的耗时，内部会调用configureExtension()    threadRecorder.record(            ExecutionType.BASE_PLUGIN_PROJECT_BASE_EXTENSION_CREATION,            project.getPath(),            null,            this::configureExtension);//记录一个方法的耗时，内部会调用createTasks()    threadRecorder.record(            ExecutionType.BASE_PLUGIN_PROJECT_TASKS_CREATION,            project.getPath(),            null,            this::createTasks);}

可以看到，这里主要执行了三个方法: configureProject()、configureExtension、createTasks()

configureProject

该方法用来配置我们的Project

private void configureProject() {             extraModelInfo = new ExtraModelInfo(projectOptions, project.getLogger());        checkGradleVersion();//创建SdkHandler，SdkHandler需要用到android.jar这个包        sdkHandler = new SdkHandler(project, getLogger());        if (!project.getGradle().getStartParameter().isOffline()                && projectOptions.get(BooleanOption.ENABLE_SDK_DOWNLOAD)                && !projectOptions.get(BooleanOption.IDE_INVOKED_FROM_IDE)) {                 SdkLibData sdkLibData = SdkLibData.download(getDownloader(), getSettingsController());            sdkHandler.setSdkLibData(sdkLibData);        }//创建一个构建的对象 AndroidBuilder        androidBuilder = new AndroidBuilder(                project == project.getRootProject() ? project.getName() : project.getPath(),                creator,                new GradleProcessExecutor(project),                new GradleJavaProcessExecutor(project),                extraModelInfo,                getLogger(),                isVerbose());//创建一个构建的对象 DataBindingBuilder        dataBindingBuilder = new DataBindingBuilder();        dataBindingBuilder.setPrintMachineReadableOutput(                extraModelInfo.getErrorFormatMode() ==                        ExtraModelInfo.ErrorFormatMode.MACHINE_PARSABLE);//关联Java和Jacoco(单元测试) Plugin        // Apply the Java and Jacoco plugins.        project.getPlugins().apply(JavaBasePlugin.class);        project.getPlugins().apply(JacocoPlugin.class);        project.getTasks()                .getByName("assemble")                .setDescription(                        "Assembles all variants of all applications and secondary packages.");        // call back on execution. This is called after the whole build is done (not        // after the current project is done).        // This is will be called for each (android) projects though, so this should support        // being called 2+ times.        project.getGradle()                .addBuildListener(                        new BuildListener() {                                 @Override                            public void buildStarted(Gradle gradle) {                                     TaskInputHelper.enableBypass();                            }                            @Override                            public void settingsEvaluated(Settings settings) {     }                            @Override                            public void projectsLoaded(Gradle gradle) {     }                            @Override                            public void projectsEvaluated(Gradle gradle) {     }                            @Override                            public void buildFinished(BuildResult buildResult) {                                     // Do not run buildFinished for included project in composite build.                                if (buildResult.getGradle().getParent() != null) {                                         return;                                }                                ExecutorSingleton.shutdown();                                sdkHandler.unload();                                threadRecorder.record(                                        ExecutionType.BASE_PLUGIN_BUILD_FINISHED,                                        project.getPath(),                                        null,                                        () -> {                                             //清除缓存                                            PreDexCache.getCache()                                                    .clear(                                                            FileUtils.join(                                                                    project.getRootProject()                                                                            .getBuildDir(),                                                                    FD_INTERMEDIATES,                                                                    "dex-cache",                                                                    "cache.xml"),                                                            getLogger());                                            Main.clearInternTables();                                        });                            }                        });        project.getGradle()                .getTaskGraph()                .addTaskExecutionGraphListener(                        taskGraph -> {                                 TaskInputHelper.disableBypass();                            for (Task task : taskGraph.getAllTasks()) {                                     if (task instanceof TransformTask) {                                         Transform transform = ((TransformTask) task).getTransform();                                    if (transform instanceof DexTransform) {                                             PreDexCache.getCache()                                                .load(                                                        FileUtils.join(                                                                project.getRootProject()                                                                        .getBuildDir(),                                                                FD_INTERMEDIATES,                                                                "dex-cache",                                                                "cache.xml"));                                        break;                                    }                                }                            }                        });    }

configureExtension

配置Extension扩展，也就是我们平时通过android{}来进行配置的内容

private void configureExtension() {     //创建4个对象容器//buildType节点   final NamedDomainObjectContainer<BuildType> buildTypeContainer =           project.container(                   BuildType.class,                   new BuildTypeFactory(instantiator, project, extraModelInfo));   //productFlavor节点   final NamedDomainObjectContainer<ProductFlavor> productFlavorContainer =           project.container(                   ProductFlavor.class,                   new ProductFlavorFactory(                           instantiator, project, project.getLogger(), extraModelInfo));//签名   final NamedDomainObjectContainer<SigningConfig> signingConfigContainer =           project.container(SigningConfig.class, new SigningConfigFactory(instantiator));//VariantOutput，变体，比如debug、release、也可和productFlavor组合   final NamedDomainObjectContainer<BaseVariantOutput> buildOutputs =           project.container(BaseVariantOutput.class);   project.getExtensions().add("buildOutputs", buildOutputs);//创建Extension   extension =           createExtension(                   project,                   projectOptions,                   instantiator,                   androidBuilder,                   sdkHandler,                   buildTypeContainer,                   productFlavorContainer,                   signingConfigContainer,                   buildOutputs,                   extraModelInfo);   ndkHandler =           new NdkHandler(                   project.getRootDir(),                   null, /* compileSkdVersion, this will be set in afterEvaluate */                   "gcc",                   "" /*toolchainVersion*/,                   false /* useUnifiedHeaders */);   @Nullable   FileCache buildCache = BuildCacheUtils.createBuildCacheIfEnabled(project, projectOptions);   GlobalScope globalScope =           new GlobalScope(                   project,                   projectOptions,                   androidBuilder,                   extension,                   sdkHandler,                   ndkHandler,                   registry,                   buildCache);   variantFactory = createVariantFactory(globalScope, instantiator, androidBuilder, extension);//创建taskManager，会管理我们Task的创建   taskManager =           createTaskManager(                   globalScope,                   project,                   projectOptions,                   androidBuilder,                   dataBindingBuilder,                   extension,                   sdkHandler,                   ndkHandler,                   registry,                   threadRecorder);//创建variantManager   variantManager =           new VariantManager(                   globalScope,                   project,                   projectOptions,                   androidBuilder,                   extension,                   variantFactory,                   taskManager,                   threadRecorder);   registerModels(registry, globalScope, variantManager, extension, extraModelInfo);   // map the whenObjectAdded callbacks on the containers.   signingConfigContainer.whenObjectAdded(variantManager::addSigningConfig);   buildTypeContainer.whenObjectAdded(           buildType -> {                    SigningConfig signingConfig =                       signingConfigContainer.findByName(BuilderConstants.DEBUG);               buildType.init(signingConfig);               variantManager.addBuildType(buildType);           });   productFlavorContainer.whenObjectAdded(variantManager::addProductFlavor);   // map whenObjectRemoved on the containers to throw an exception.   signingConfigContainer.whenObjectRemoved(           new UnsupportedAction("Removing signingConfigs is not supported."));   buildTypeContainer.whenObjectRemoved(           new UnsupportedAction("Removing build types is not supported."));   productFlavorContainer.whenObjectRemoved(           new UnsupportedAction("Removing product flavors is not supported."));   // create default Objects, signingConfig first as its used by the BuildTypes.   variantFactory.createDefaultComponents(           buildTypeContainer, productFlavorContainer, signingConfigContainer);}

createTasks

该方法用来创建一系列Task

private void createTasks() {     //记录耗时，并调用createTasksBeforeEvaluate()//createTasksBeforeEvaluate会创建很多Task，但是都是和系统相关的//比如卸载应用，系统检测，连接设备等 threadRecorder.record(            ExecutionType.TASK_MANAGER_CREATE_TASKS,            project.getPath(),            null,            () ->                    taskManager.createTasksBeforeEvaluate(                            new TaskContainerAdaptor(project.getTasks())));    project.afterEvaluate( //afterEvaluate调用时，项目已经配置好了            project ->            //记录耗时，并调用createAndroidTasks()来创建Task，不同的productFlavor、buildTypes创建的task也不同                    threadRecorder.record(                            ExecutionType.BASE_PLUGIN_CREATE_ANDROID_TASKS,                            project.getPath(),                            null,                            () -> createAndroidTasks(false)));}

来看createAndroidTasks()

//...threadRecorder.record(ExecutionType.VARIANT_MANAGER_CREATE_ANDROID_TASKS,    project.getPath(),    null,    () -> {         //调用variantManager的createAndroidTasks()        variantManager.createAndroidTasks();        ApiObjectFactory apiObjectFactory =                new ApiObjectFactory(                        androidBuilder,                        extension,                        variantFactory,                        instantiator,                        project.getObjects());        for (VariantScope variantScope : variantManager.getVariantScopes()) {                 BaseVariantData variantData = variantScope.getVariantData();                  apiObjectFactory.create(variantData);              }          });//...

来看variantManager.createAndroidTasks()

public void createAndroidTasks() {             variantFactory.validateModel(this);        variantFactory.preVariantWork(project);        final TaskFactory tasks = new TaskContainerAdaptor(project.getTasks());        if (variantScopes.isEmpty()) {                 recorder.record(                    ExecutionType.VARIANT_MANAGER_CREATE_VARIANTS,                    project.getPath(),                    null /*variantName*/,                    //创建出所有的variant变体                    this::populateVariantDataList);        }        // Create top level test tasks.        recorder.record(                ExecutionType.VARIANT_MANAGER_CREATE_TESTS_TASKS,                project.getPath(),                null /*variantName*/,                //创建测试使用的方法                () -> taskManager.createTopLevelTestTasks(tasks, !productFlavors.isEmpty()));        for (final VariantScope variantScope : variantScopes) {                 recorder.record(                    ExecutionType.VARIANT_MANAGER_CREATE_TASKS_FOR_VARIANT,                    project.getPath(),                    variantScope.getFullVariantName(),                    //根据Variant变体创建出相应的一堆Task                    () -> createTasksForVariantData(tasks, variantScope));        }//创建依赖报告、签名报告的Task        taskManager.createReportTasks(tasks, variantScopes);    }

来看createTasksForVariantData

public void createTasksForVariantData(final TaskFactory tasks, final VariantScope variantScope) {     final BaseVariantData variantData = variantScope.getVariantData();final VariantType variantType = variantData.getType();final GradleVariantConfiguration variantConfig = variantScope.getVariantConfiguration();//添加assemble开头的一系列Taskfinal BuildTypeData buildTypeData = buildTypes.get(variantConfig.getBuildType().getName());if (buildTypeData.getAssembleTask() == null) {     buildTypeData.setAssembleTask(taskManager.createAssembleTask(tasks, buildTypeData));}tasks.named("assemble", new Action<Task>() {     @Overridepublic void execute(Task task) {     assert buildTypeData.getAssembleTask() != null;task.dependsOn(buildTypeData.getAssembleTask().getName());}});createAssembleTaskForVariantData(tasks, variantData);//是否是测试的Taskif (variantType.isForTesting()) {     //...} else {     //创建一堆TasktaskManager.createTasksForVariantScope(tasks, variantScope);}}

可以看到，最终会调用createTasksForVariantScope()

@Overridepublic void createTasksForVariantScope(@NonNull final TaskFactory tasks, @NonNull final VariantScope variantScope) {     BaseVariantData variantData = variantScope.getVariantData();assert variantData instanceof ApplicationVariantData;createAnchorTasks(tasks, variantScope);//检查Manifest是否符合规范 -> PreBuildTaskcreateCheckManifestTask(tasks, variantScope);handleMicroApp(tasks, variantScope);// Create all current streams (dependencies mostly at this point)createDependencyStreams(tasks, variantScope);// Add a task to publish the applicationId.createApplicationIdWriterTask(tasks, variantScope);// Add a task to process the manifest(s)recorder.record(//合并ManifestExecutionType.APP_TASK_MANAGER_CREATE_MERGE_MANIFEST_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createMergeApkManifestsTask(tasks, variantScope));// Add a task to create the res valuesrecorder.record(//生成res valuesExecutionType.APP_TASK_MANAGER_CREATE_GENERATE_RES_VALUES_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createGenerateResValuesTask(tasks, variantScope));// Add a task to compile renderscript files.recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_CREATE_RENDERSCRIPT_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createRenderscriptTask(tasks, variantScope));// Add a task to merge the resource folders//合并Resource文件recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_MERGE_RESOURCES_TASK,project.getPath(),variantScope.getFullVariantName(),(Recorder.VoidBlock) () -> createMergeResourcesTask(tasks, variantScope, true));// Add a task to merge the asset foldersrecorder.record(//合并Assert文件ExecutionType.APP_TASK_MANAGER_CREATE_MERGE_ASSETS_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createMergeAssetsTask(tasks, variantScope, null));// Add a task to create the BuildConfig classrecorder.record(//创建BuildConfig.javaExecutionType.APP_TASK_MANAGER_CREATE_BUILD_CONFIG_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createBuildConfigTask(tasks, variantScope));recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_PROCESS_RES_TASK,project.getPath(),variantScope.getFullVariantName(),() -> {     // Add a task to process the Android Resources and generate source filescreateApkProcessResTask(tasks, variantScope);// Add a task to process the java resourcescreateProcessJavaResTask(tasks, variantScope);});recorder.record(//创建AIDLExecutionType.APP_TASK_MANAGER_CREATE_AIDL_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createAidlTask(tasks, variantScope));recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_SHADER_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createShaderTask(tasks, variantScope));// Add NDK tasksif (!isComponentModelPlugin()) {     recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_NDK_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createNdkTasks(tasks, variantScope));} else {     if (variantData.compileTask != null) {     variantData.compileTask.dependsOn(getNdkBuildable(variantData));} else {     variantScope.getCompileTask().dependsOn(tasks, getNdkBuildable(variantData));}}variantScope.setNdkBuildable(getNdkBuildable(variantData));// Add external native build tasksrecorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_EXTERNAL_NATIVE_BUILD_TASK,project.getPath(),variantScope.getFullVariantName(),() -> {     createExternalNativeBuildJsonGenerators(variantScope);createExternalNativeBuildTasks(tasks, variantScope);});// Add a task to merge the jni libs foldersrecorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_MERGE_JNILIBS_FOLDERS_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createMergeJniLibFoldersTasks(tasks, variantScope));// Add data binding tasks if enabledcreateDataBindingTasksIfNecessary(tasks, variantScope);// Add a compile taskrecorder.record(//编译代码ExecutionType.APP_TASK_MANAGER_CREATE_COMPILE_TASK,project.getPath(),variantScope.getFullVariantName(),() -> addCompileTask(tasks, variantScope));createStripNativeLibraryTask(tasks, variantScope);if (variantScope.getOutputScope().getMultiOutputPolicy().equals(MultiOutputPolicy.SPLITS)) {     if (extension.getBuildToolsRevision().getMajor() < 21) {     throw new RuntimeException("Pure splits can only be used with buildtools 21 and later");}recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_SPLIT_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createSplitTasks(tasks, variantScope));}recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_PACKAGING_TASK,project.getPath(),variantScope.getFullVariantName(),() -> {     AndroidTask<BuildInfoWriterTask> buildInfoWriterTask =createInstantRunPackagingTasks(tasks, variantScope);createPackagingTask(tasks, variantScope, buildInfoWriterTask);});// create the lint tasks.recorder.record(ExecutionType.APP_TASK_MANAGER_CREATE_LINT_TASK,project.getPath(),variantScope.getFullVariantName(),() -> createLintTasks(tasks, variantScope));}

可以看到，这里创建了很多的Task。
至此，我们对AppPlugin的初始化工作有了一定的了解。
下篇文章我们来详见讲解下AppPlugin中的Task。

Android 编译流程解析系列
Android 编译流程解析01-AppPlugin初始化
Android 编译流程解析02-相关Task解析
Android 编译流程解析03-手动编译Apk

简介

configureProject

configureExtension

createTasks

更多相关文章

随机推荐