Support android builds via AGP

gradle/libs.versions.toml

@@ -4,15 +4,17 @@ kotlin = "1.8.21"
 ktlintGradle = "11.3.2"
 pluginPublish = "1.2.0"
 versionCheck = "0.46.0"
+androidGradlePlugin = "7.3.0"
 
 [plugins]
-detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt"}
-kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin"}
-ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlintGradle"}
-pluginPublish = { id = "com.gradle.plugin-publish", version.ref = "pluginPublish"}
-versionCheck = { id = "com.github.ben-manes.versions", version.ref = "versionCheck"}
+detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt" }
+kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
+ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlintGradle" }
+pluginPublish = { id = "com.gradle.plugin-publish", version.ref = "pluginPublish" }
+versionCheck = { id = "com.github.ben-manes.versions", version.ref = "versionCheck" }
 
 [libraries]
 junit = "junit:junit:4.13.2"
 truth = "com.google.truth:truth:1.1.3"
 asm = "org.ow2.asm:asm:9.4"
+androidGradlePlugin = { group = "com.android.tools.build", name = "gradle", version.ref = "androidGradlePlugin" }

plugin-build/plugin/build.gradle.kts

@@ -10,6 +10,7 @@ dependencies {
     implementation(kotlin("stdlib"))
     implementation(gradleApi())
     implementation(libs.asm)
+    implementation(libs.androidGradlePlugin)
 
     testImplementation(libs.junit)
     testImplementation(libs.truth)

plugin-build/plugin/src/main/java/com/axzae/unmeta/UnmetaClassVisitor.kt

@@ -1,35 +1,25 @@
 package com.axzae.unmeta
 
-import org.gradle.api.logging.Logger
 import org.objectweb.asm.AnnotationVisitor
 import org.objectweb.asm.ClassVisitor
 import org.objectweb.asm.Opcodes
 
 class UnmetaClassVisitor(
-    private val path: String,
+    val path: String,
     classVisitor: ClassVisitor,
-    private val logger: Logger,
 ) : ClassVisitor(Opcodes.ASM7, classVisitor), Opcodes {
 
-    var modified = false
-
-    override fun visitAnnotation(desc: String?, visible: Boolean): AnnotationVisitor? {
-        return when (desc) {
-            "Lkotlin/Metadata;" -> {
-                logger.debug("Removed @Metadata annotation from $path")
-                modified = true
-                null
-            }
+    var isModified = false
+        private set
 
+    override fun visitAnnotation(descriptor: String?, visible: Boolean): AnnotationVisitor? {
+        return when (descriptor) {
             "Lkotlin/coroutines/jvm/internal/DebugMetadata;" -> {
-                logger.debug("Removed @DebugMetadata annotation from $path")
-                modified = true
+                isModified = true
                 null
             }
 
-            else -> {
-                super.visitAnnotation(desc, visible)
-            }
+            else -> super.visitAnnotation(descriptor, visible)
         }
     }
 }

plugin-build/plugin/src/main/java/com/axzae/unmeta/UnmetaExtension.kt

@@ -1,10 +1,13 @@
 package com.axzae.unmeta
 
 import org.gradle.api.Project
+import org.gradle.api.file.RegularFileProperty
 import org.gradle.api.provider.Property
 import javax.inject.Inject
 
 const val DEFAULT_IS_ENABLED = true
+const val DEFAULT_VERBOSE = false
+const val DEFAULT_OUTPUT_FILE = "outputs/logs/unmeta.txt"
 
 @Suppress("UnnecessaryAbstractClass")
 abstract class UnmetaExtension @Inject constructor(project: Project) {
@@ -13,4 +16,10 @@ abstract class UnmetaExtension @Inject constructor(project: Project) {
 
     val isEnabled: Property<Boolean> = objects.property(Boolean::class.java)
         .convention(DEFAULT_IS_ENABLED)
+
+    val verbose: Property<Boolean> = objects.property(Boolean::class.java)
+        .convention(DEFAULT_VERBOSE)
+
+    val outputFile: RegularFileProperty = objects.fileProperty()
+        .convention(project.layout.buildDirectory.file(DEFAULT_OUTPUT_FILE))
 }

plugin-build/plugin/src/main/java/com/axzae/unmeta/UnmetaPlugin.kt

@@ -1,17 +1,25 @@
 package com.axzae.unmeta
 
+import com.android.build.api.variant.ApplicationAndroidComponentsExtension
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-
-const val EXTENSION_NAME = "unmeta"
-const val TASK_NAME = "unmetaTask"
+import org.gradle.configurationcache.extensions.capitalized
 
 abstract class UnmetaPlugin : Plugin<Project> {
     override fun apply(project: Project) {
-        val extension = project.extensions.create(EXTENSION_NAME, UnmetaExtension::class.java, project)
-
-        project.tasks.register(TASK_NAME, UnmetaTask::class.java) {
-            it.isEnabled = extension.isEnabled.get()
+        val extension = project.extensions.create("unmeta", UnmetaExtension::class.java, project)
+        val androidComponents = project.extensions.getByType(ApplicationAndroidComponentsExtension::class.java)
+        androidComponents.onVariants(androidComponents.selector().withBuildType("release")) { variant ->
+            val compileKotlinTaskName = "compile${variant.name.capitalized()}Kotlin"
+            val unmetaTask = project.tasks.create("unmeta${variant.name.capitalized()}", UnmetaTask::class.java).apply {
+                isEnabled = extension.isEnabled.get()
+                verbose.set(extension.verbose.get())
+                variantName.set(variant.name)
+                outputFile.set(extension.outputFile)
+            }
+            project.afterEvaluate {
+                project.tasks.findByName(compileKotlinTaskName)?.finalizedBy(unmetaTask)
+            }
         }
     }
 }

plugin-build/plugin/src/main/java/com/axzae/unmeta/UnmetaTask.kt

@@ -1,11 +1,17 @@
 package com.axzae.unmeta
 
 import org.gradle.api.DefaultTask
+import org.gradle.api.file.RegularFileProperty
 import org.gradle.api.plugins.BasePlugin
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.OutputFile
 import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.options.Option
 import org.objectweb.asm.ClassReader
 import org.objectweb.asm.ClassWriter
 import java.io.File
+import kotlin.system.measureTimeMillis
 
 abstract class UnmetaTask : DefaultTask() {
 
@@ -14,27 +20,54 @@ abstract class UnmetaTask : DefaultTask() {
         group = BasePlugin.BUILD_GROUP
     }
 
+    @get:Input
+    @get:Option(option = "variantName", description = "Android variant (flavor + buildType)")
+    abstract val variantName: Property<String>
+
+    @get:Input
+    @get:Option(option = "verbose", description = "Enable verbose logging")
+    abstract val verbose: Property<Boolean>
+
+    @get:OutputFile
+    abstract val outputFile: RegularFileProperty
+
+    private val fileLogger by lazy { outputFile.get().asFile }
+
     @TaskAction
     fun unmetaAction() {
         if (!isEnabled) {
-            logger.warn("unmeta is disabled")
+            log("unmeta is disabled")
             return
         }
-
-        logger.info("Start dropping @Metadata & @DebugMetadata from kotlin classes")
-        project.buildDir.listFiles()?.forEach { file -> if (file.isDirectory) dropMetadata(file) }
+        log("Start dropping @DebugMetadata from kotlin classes")
+        val executionMs = measureTimeMillis {
+            val kotlinClassesPath = project.buildDir.absolutePath + "/tmp/kotlin-classes/${variantName.get()}"
+            File(kotlinClassesPath).listFiles()?.forEach { file ->
+                if (file.isDirectory) removeAnnotation(file)
+            }
+        }
+        log("Unmeta Total Time: ${executionMs}ms")
     }
 
-    private fun dropMetadata(directory: File) {
+    private fun log(message: String) {
+        when (verbose.get()) {
+            true -> logger.lifecycle(message)
+            else -> logger.debug(message)
+        }
+        fileLogger.appendText(message + System.lineSeparator(), Charsets.UTF_8)
+    }
+
+    private fun removeAnnotation(directory: File) {
         directory.walk()
             .filter { it.path.contains("classes") && it.path.endsWith(".class") && it.isFile }
             .forEach {
                 val sourceClassBytes = it.readBytes()
                 val classReader = ClassReader(sourceClassBytes)
                 val classWriter = ClassWriter(classReader, ClassWriter.COMPUTE_MAXS)
-                val unmetaClassVisitor = UnmetaClassVisitor(it.absolutePath, classWriter, logger)
+                val unmetaClassVisitor = UnmetaClassVisitor(it.absolutePath, classWriter)
                 classReader.accept(unmetaClassVisitor, ClassReader.SKIP_DEBUG)
-                if (unmetaClassVisitor.modified) {
+                if (unmetaClassVisitor.isModified) {
+                    log("Removed @DebugMetadata annotation from ${unmetaClassVisitor.path}")
                     it.writeBytes(classWriter.toByteArray())
                 }
             }

plugin-build/settings.gradle.kts

@@ -31,6 +31,4 @@ gradleEnterprise {
     }
 }
 
-rootProject.name = ("com.axzae.unmeta")
-
 include(":plugin")

settings.gradle.kts

@@ -2,6 +2,7 @@ pluginManagement {
     repositories {
         gradlePluginPortal()
         mavenCentral()
+        google()
     }
 }