Reduce overhead on wiring task inputs to Android layouts

^KT-53118 In Progress

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/AbstractKotlinAndroidGradleTests.kt

@@ -1027,12 +1027,12 @@ abstract class AbstractKotlinAndroidGradleTests : BaseGradleIT() {
 
         project.projectDir.resolve("app/build.gradle").appendText(
             """
-        |
-        |androidExtensions {
-            |    experimental = true
             |
-        }
-        """.trimMargin()
+            |androidExtensions {
+            |    experimental = true
+            |}
+            |
+            """.trimMargin()
         )
 
         project.build("assembleDebug") {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/AndroidProjectHandler.kt

@@ -9,7 +9,6 @@ package org.jetbrains.kotlin.gradle.plugin
 import com.android.build.api.attributes.BuildTypeAttr
 import com.android.build.gradle.*
 import com.android.build.gradle.api.*
-import com.android.build.gradle.tasks.MergeResources
 import org.gradle.api.InvalidUserCodeException
 import org.gradle.api.NamedDomainObjectCollection
 import org.gradle.api.Project
@@ -18,7 +17,6 @@ import org.gradle.api.artifacts.component.ProjectComponentIdentifier
 import org.gradle.api.attributes.Attribute
 import org.gradle.api.attributes.Category
 import org.gradle.api.file.ConfigurableFileTree
-import org.gradle.api.file.FileCollection
 import org.gradle.api.file.SourceDirectorySet
 import org.gradle.api.logging.Logging
 import org.gradle.api.plugins.InvalidPluginException
@@ -375,43 +373,6 @@ internal fun forEachVariant(project: Project, action: (BaseVariant) -> Unit) {
     }
 }
 
-internal fun BaseVariant.getResDirectories(): FileCollection {
-    val getAllResourcesMethod =
-        this::class.java.methods.firstOrNull { it.name == "getAllRawAndroidResources" }
-    if (getAllResourcesMethod != null) {
-        val allResources = getAllResourcesMethod.invoke(this) as FileCollection
-        return allResources
-    }
-
-    val project = mergeResources.project
-    return project.files(Callable { mergeResources?.computeResourceSetList0() ?: emptyList() })
-}
-
-//TODO A public API is expected for this purpose. Once it is available, use the public API
-private fun MergeResources.computeResourceSetList0(): List<File>? {
-    val computeResourceSetListMethod = MergeResources::class.java.declaredMethods
-        .firstOrNull { it.name == "computeResourceSetList" && it.parameterCount == 0 } ?: return null
-
-    val oldIsAccessible = computeResourceSetListMethod.isAccessible
-    try {
-        computeResourceSetListMethod.isAccessible = true
-
-        val resourceSets = computeResourceSetListMethod.invoke(this) as? Iterable<*>
-
-        return resourceSets
-            ?.mapNotNull { resourceSet ->
-                val getSourceFiles = resourceSet?.javaClass?.methods?.find { it.name == "getSourceFiles" && it.parameterCount == 0 }
-                val files = getSourceFiles?.invoke(resourceSet)
-                @Suppress("UNCHECKED_CAST")
-                files as? Iterable<File>
-            }
-            ?.flatten()
-
-    } finally {
-        computeResourceSetListMethod.isAccessible = oldIsAccessible
-    }
-}
-
 /** Filter for the AGP test variant classpath artifacts. */
 class AndroidTestedVariantArtifactsFilter(
     private val artifactCollection: ArtifactCollection,

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/internal/AndroidSubplugin.kt

@@ -13,12 +13,10 @@ import com.android.build.gradle.api.TestVariant
 import com.android.build.gradle.internal.variant.TestVariantData
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.api.file.FileCollection
+import org.gradle.api.file.ConfigurableFileTree
 import org.gradle.api.provider.Provider
-import org.gradle.api.tasks.PathSensitivity
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.tooling.provider.model.ToolingModelBuilderRegistry
-import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.model.builder.KotlinAndroidExtensionModelBuilder
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
@@ -130,31 +128,30 @@ class AndroidSubplugin : KotlinCompilerPluginSupportPlugin {
                 )
             )
             kotlinCompilation.compileKotlinTaskProvider.configure {
-                it.androidLayoutResourceFiles.from(getLayoutDirectories(project, sourceSet.res.srcDirs))
+                it.androidLayoutResourceFiles.from(
+                    sourceSet.res.sourceDirectoryTrees.layoutDirectories
+                )
             }
         }
 
         addVariant(mainSourceSet)
 
-        val flavorSourceSets = androidExtension.productFlavors
-            .mapNotNull { androidExtension.sourceSets.findByName(it.name) }
-
-        for (sourceSet in flavorSourceSets) {
-            addVariant(sourceSet)
+        androidExtension.productFlavors.configureEach { flavor ->
+            androidExtension.sourceSets.findByName(flavor.name)?.let {
+                addVariant(it)
+            }
         }
 
         return project.provider { wrapPluginOptions(pluginOptions, "configuration") }
     }
 
-    private fun getLayoutDirectories(project: Project, resDirectories: Iterable<File>): FileCollection {
-        fun isLayoutDirectory(file: File) = file.name == "layout" || file.name.startsWith("layout-")
-
-        return project.files(Callable {
-            resDirectories.flatMap { resDir ->
-                (resDir.listFiles(::isLayoutDirectory)).orEmpty().asList()
+    private val List<ConfigurableFileTree>.layoutDirectories
+        get() = map { tree ->
+            tree.matching {
+                it.include("**/layout/**")
+                it.include("**/layout-*/**")
             }
-        })
-    }
+        }
 
     private fun applyExperimental(
         kotlinCompile: TaskProvider<out KotlinCompile>,
@@ -178,55 +175,39 @@ class AndroidSubplugin : KotlinCompilerPluginSupportPlugin {
         val mainSourceSet = androidExtension.sourceSets.getByName("main")
         pluginOptions += SubpluginOption("package", getApplicationPackage(androidExtension, project, mainSourceSet))
 
-        fun addVariant(name: String, resDirectories: FileCollection) {
+        fun addVariant(name: String, resDirectories: List<ConfigurableFileTree>) {
             val optionValue = lazy {
                 buildString {
                     append(name)
                     append(';')
-                    resDirectories.joinTo(this, separator = ";") { it.canonicalPath }
+                    resDirectories.map { it.dir }.joinTo(this, separator = ";") { it.canonicalPath }
                 }
             }
             pluginOptions += CompositeSubpluginOption(
                 "variant", optionValue, listOf(
                     SubpluginOption("variantName", name),
                     // use INTERNAL option kind since the resources are tracked as sources (see below)
-                    FilesSubpluginOption("resDirs", resDirectories)
+                    FilesSubpluginOption(
+                        "resDirs",
+                        resDirectories.map { it.dir }
+                    )
                 )
             )
 
             kotlinCompile.configure {
-                it.inputs.files(getLayoutDirectories(project, resDirectories))
-                    .withPathSensitivity(PathSensitivity.RELATIVE)
-                    .withPropertyName("androidExtensionLayoutsFrom$name")
-                    .skipWhenEmpty(true)
-                    .run {
-                        if (GradleVersion.current() >= GradleVersion.version("6.8")) {
-                            ignoreEmptyDirectories()
-                        } else {
-                            this!!
-                        }
-                    }
+                it.androidLayoutResourceFiles.from(resDirectories.layoutDirectories)
             }
         }
 
         fun addSourceSetAsVariant(name: String) {
             val sourceSet = androidExtension.sourceSets.findByName(name) ?: return
-            val srcDirs = sourceSet.res.srcDirs.toList()
+            val srcDirs = sourceSet.res.sourceDirectoryTrees
             if (srcDirs.isNotEmpty()) {
-                addVariant(sourceSet.name, project.files(srcDirs))
+                addVariant(sourceSet.name, srcDirs)
             }
         }
 
-        val resDirectoriesForAllVariants = mutableListOf<FileCollection>()
-
-        forEachVariant(project) { variant ->
-            if (getTestedVariantData(variant) != null) return@forEachVariant
-            resDirectoriesForAllVariants += variant.getResDirectories()
-        }
-
-        val commonResDirectories = getCommonResDirectories(project, resDirectoriesForAllVariants)
-
-        addVariant("main", commonResDirectories)
+        addSourceSetAsVariant("main")
 
         getVariantComponentNames(variantData)?.let { (variantName, flavorName, buildTypeName) ->
             addSourceSetAsVariant(buildTypeName)
@@ -252,19 +233,6 @@ class AndroidSubplugin : KotlinCompilerPluginSupportPlugin {
 
     private data class VariantComponentNames(val variantName: String, val flavorName: String, val buildTypeName: String)
 
-    private fun getCommonResDirectories(project: Project, resDirectories: List<FileCollection>): FileCollection {
-        val lazyFiles = lazy {
-            if (resDirectories.isEmpty()) {
-                emptySet<File>()
-            } else {
-                resDirectories.first().toMutableSet().apply {
-                    resDirectories.drop(1).forEach { retainAll(it) }
-                }
-            }
-        }
-        return project.files(Callable { lazyFiles.value })
-    }
-
     private fun getApplicationPackage(androidExtension: BaseExtension, project: Project, mainSourceSet: AndroidSourceSet): String {
         val manifestFile = mainSourceSet.manifest.srcFile
         val applicationPackage = getApplicationPackage(androidExtension, manifestFile)