[Gradle] Remove old classpath snapshot transformation

Leave only the implementation via the build tools API in order to reduce compiler dependencies.
THe old implementation expects to have many of compiler modules (through `kotlin-compiler-embeddable`) in the plugin runtime classpath
#KT-61449 In Progress

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/transforms/ClasspathEntrySnapshotTransform.kt

@@ -1,105 +0,0 @@
-/*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.gradle.internal.transforms
-
-import org.gradle.api.artifacts.transform.*
-import org.gradle.api.file.DirectoryProperty
-import org.gradle.api.file.FileSystemLocation
-import org.gradle.api.provider.Property
-import org.gradle.api.provider.Provider
-import org.gradle.api.tasks.Classpath
-import org.gradle.api.tasks.Internal
-import org.jetbrains.kotlin.build.report.metrics.*
-import org.jetbrains.kotlin.gradle.report.BuildMetricsService
-import org.jetbrains.kotlin.buildtools.api.jvm.ClassSnapshotGranularity
-import org.jetbrains.kotlin.buildtools.api.jvm.ClassSnapshotGranularity.CLASS_LEVEL
-import org.jetbrains.kotlin.buildtools.api.jvm.ClassSnapshotGranularity.CLASS_MEMBER_LEVEL
-import org.jetbrains.kotlin.incremental.classpathDiff.ClasspathEntrySnapshotExternalizer
-import org.jetbrains.kotlin.incremental.classpathDiff.ClasspathEntrySnapshotter
-import org.jetbrains.kotlin.incremental.storage.saveToFile
-import java.io.File
-
-/** Transform to create a snapshot of a classpath entry (directory or jar). */
-@CacheableTransform
-abstract class ClasspathEntrySnapshotTransform : TransformAction<ClasspathEntrySnapshotTransform.Parameters> {
-
-    abstract class Parameters : TransformParameters {
-        @get:Internal
-        abstract val gradleUserHomeDir: DirectoryProperty
-
-        @get:Internal
-        abstract val buildMetricsService: Property<BuildMetricsService>
-    }
-
-    @get:Classpath
-    @get:InputArtifact
-    abstract val inputArtifact: Provider<FileSystemLocation>
-
-    override fun transform(outputs: TransformOutputs) {
-        val classpathEntryInputDirOrJar = inputArtifact.get().asFile
-        val snapshotOutputFile = outputs.file(classpathEntryInputDirOrJar.name.replace('.', '_') + "-snapshot.bin")
-
-        val granularity = getClassSnapshotGranularity(classpathEntryInputDirOrJar, parameters.gradleUserHomeDir.get().asFile)
-
-        val buildMetricsReporterService = parameters.buildMetricsService.orNull
-        val metricsReporter = buildMetricsReporterService?.let { BuildMetricsReporterImpl() } ?: DoNothingBuildMetricsReporter
-
-        val startTimeMs = System.currentTimeMillis()
-        var failureMessage: String? = null
-        try {
-            doTransform(classpathEntryInputDirOrJar, snapshotOutputFile, granularity, metricsReporter)
-        } catch (e: Throwable) {
-            failureMessage = e.message
-            throw e
-        } finally {
-            buildMetricsReporterService?.addTransformMetrics(
-                transformPath = "${ClasspathEntrySnapshotTransform::class.simpleName} for ${classpathEntryInputDirOrJar.path}",
-                transformClass = ClasspathEntrySnapshotTransform::class.java,
-                isKotlinTransform = true,
-                startTimeMs = startTimeMs,
-                totalTimeMs = System.currentTimeMillis() - startTimeMs,
-                buildMetrics = metricsReporter.getMetrics(),
-                failureMessage = failureMessage
-            )
-        }
-    }
-
-    /**
-     * Determines the [ClassSnapshotGranularity] when taking a snapshot of the given [classpathEntryDirOrJar].
-     *
-     * As mentioned in [ClassSnapshotGranularity]'s kdoc, we will take [CLASS_LEVEL] snapshots for classes that are infrequently changed
-     * (e.g., external libraries which are typically stored/transformed inside the Gradle user home, or a few hard-coded cases), and take
-     * [CLASS_MEMBER_LEVEL] snapshots for the others.
-     */
-    private fun getClassSnapshotGranularity(classpathEntryDirOrJar: File, gradleUserHomeDir: File): ClassSnapshotGranularity {
-        return if (
-            classpathEntryDirOrJar.startsWith(gradleUserHomeDir) ||
-            classpathEntryDirOrJar.name == "android.jar"
-        ) CLASS_LEVEL
-        else CLASS_MEMBER_LEVEL
-    }
-
-    private fun doTransform(
-        classpathEntryInputDirOrJar: File, snapshotOutputFile: File,
-        granularity: ClassSnapshotGranularity, metrics: BuildMetricsReporter<GradleBuildTime, GradleBuildPerformanceMetric>
-    ) {
-        metrics.measure(GradleBuildTime.CLASSPATH_ENTRY_SNAPSHOT_TRANSFORM) {
-            val snapshot = ClasspathEntrySnapshotter.snapshot(classpathEntryInputDirOrJar, granularity, metrics)
-            metrics.measure(GradleBuildTime.SAVE_CLASSPATH_ENTRY_SNAPSHOT) {
-                ClasspathEntrySnapshotExternalizer.saveToFile(snapshotOutputFile, snapshot)
-            }
-        }
-
-        metrics.addMetric(GradleBuildPerformanceMetric.CLASSPATH_ENTRY_SNAPSHOT_TRANSFORM_EXECUTION_COUNT, 1)
-        if (classpathEntryInputDirOrJar.extension.equals("jar", ignoreCase = true)) {
-            metrics.addMetric(GradleBuildPerformanceMetric.JAR_CLASSPATH_ENTRY_SIZE, classpathEntryInputDirOrJar.length())
-            metrics.addMetric(GradleBuildPerformanceMetric.JAR_CLASSPATH_ENTRY_SNAPSHOT_SIZE, snapshotOutputFile.length())
-        } else {
-            // Only compute the size of the snapshot, not the size of the input directory as walking the file tree has a small overhead
-            metrics.addMetric(GradleBuildPerformanceMetric.DIRECTORY_CLASSPATH_ENTRY_SNAPSHOT_SIZE, snapshotOutputFile.length())
-        }
-    }
-}

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/configuration/KotlinCompileConfig.kt

@@ -15,7 +15,6 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinJvmProjectExtension
 import org.jetbrains.kotlin.gradle.dsl.KotlinTopLevelExtension
 import org.jetbrains.kotlin.gradle.internal.ClassLoadersCachingBuildService
 import org.jetbrains.kotlin.gradle.internal.transforms.BuildToolsApiClasspathEntrySnapshotTransform
-import org.jetbrains.kotlin.gradle.internal.transforms.ClasspathEntrySnapshotTransform
 import org.jetbrains.kotlin.gradle.plugin.BUILD_TOOLS_API_CLASSPATH_CONFIGURATION_NAME
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilationInfo
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
@@ -23,7 +22,6 @@ import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmCompilation
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinWithJavaCompilation
 import org.jetbrains.kotlin.gradle.utils.markResolvable
 import org.jetbrains.kotlin.gradle.plugin.tcsOrNull
-import org.jetbrains.kotlin.gradle.report.BuildMetricsService
 import org.jetbrains.kotlin.gradle.tasks.DefaultKotlinJavaToolchain
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import org.jetbrains.kotlin.gradle.utils.providerWithLazyConvention
@@ -36,9 +34,8 @@ internal open class BaseKotlinCompileConfig<TASK : KotlinCompile> : AbstractKotl
         configureTaskProvider { taskProvider ->
             val useClasspathSnapshot = propertiesProvider.useClasspathSnapshot
             val classpathConfiguration = if (useClasspathSnapshot) {
-                val runKotlinCompilerViaBuildToolsApi = propertiesProvider.runKotlinCompilerViaBuildToolsApi
                 val jvmToolchain = taskProvider.flatMap { it.defaultKotlinJavaToolchain }
-                registerTransformsOnce(project, jvmToolchain, runKotlinCompilerViaBuildToolsApi)
+                registerTransformsOnce(project, jvmToolchain)
                 // Note: Creating configurations should be done during build configuration, not task configuration, to avoid issues with
                 // composite builds (e.g., https://issuetracker.google.com/183952598).
                 project.configurations.detachedConfiguration(
@@ -120,34 +117,13 @@ internal open class BaseKotlinCompileConfig<TASK : KotlinCompile> : AbstractKotl
     private fun registerTransformsOnce(
         project: Project,
         jvmToolchain: Provider<DefaultKotlinJavaToolchain>,
-        runKotlinCompilerViaBuildToolsApi: Boolean,
     ) {
         if (project.extensions.extraProperties.has(TRANSFORMS_REGISTERED)) {
             return
         }
         project.extensions.extraProperties[TRANSFORMS_REGISTERED] = true
 
-        if (runKotlinCompilerViaBuildToolsApi) {
-            registerBuildToolsApiTransformations(project, jvmToolchain)
-        } else {
-            registerOldTransformations(project)
-        }
-    }
-
-    private fun registerOldTransformations(project: Project) {
-        val buildMetricsService = BuildMetricsService.registerIfAbsent(project)
-        project.dependencies.registerTransform(ClasspathEntrySnapshotTransform::class.java) {
-            it.from.attribute(ARTIFACT_TYPE_ATTRIBUTE, JAR_ARTIFACT_TYPE)
-            it.to.attribute(ARTIFACT_TYPE_ATTRIBUTE, CLASSPATH_ENTRY_SNAPSHOT_ARTIFACT_TYPE)
-            it.parameters.gradleUserHomeDir.set(project.gradle.gradleUserHomeDir)
-            buildMetricsService?.apply { it.parameters.buildMetricsService.set(this) }
-        }
-        project.dependencies.registerTransform(ClasspathEntrySnapshotTransform::class.java) {
-            it.from.attribute(ARTIFACT_TYPE_ATTRIBUTE, DIRECTORY_ARTIFACT_TYPE)
-            it.to.attribute(ARTIFACT_TYPE_ATTRIBUTE, CLASSPATH_ENTRY_SNAPSHOT_ARTIFACT_TYPE)
-            it.parameters.gradleUserHomeDir.set(project.gradle.gradleUserHomeDir)
-            buildMetricsService?.apply { it.parameters.buildMetricsService.set(this) }
-        }
+        registerBuildToolsApiTransformations(project, jvmToolchain)
     }
 
     private fun TransformSpec<BuildToolsApiClasspathEntrySnapshotTransform.Parameters>.configureCommonParameters(