Optimize codenarc task on rerun (#11677)

refactor: Apply normalization on every project

perf: Insulate the BuildTimeInstrumentationPlugin from changes using a ClasspathNormalizer

BuildTimeInstrumentationPlugin install a post-processing step onto
normal compile tasks.

Flow:
1. It creates a resolvable `buildTimeInstrumentationPlugin`
   configuration
2. For each main `compileJava` / `compileGroovy` / `compileScala` task,
   it registers that configuration as a **compile-task input**
3. Then appends a `doLast("instrumentClasses", ...)` action to
   post-process compiled classes. That action runs Byte Buddy plugins
   against the compiled class output.

If any input for that task changes, the whole compile task reruns.

In particular the Byte Buddy plugins are tracked via

```kotlin
inputs.files(project.configurations.named(BUILD_TIME_INSTRUMENTATION_PLUGIN_CONFIGURATION))
```

In particular instrumentation plugins rely on instrumentation plugins
coming from `agent-tooling` project which also happens to have a version
file

```Gradle
subProj.configurations.named('buildTimeInstrumentationPlugin') {
  it.dependencies.add(subProj.dependencies.project(
    path: ':dd-java-agent:agent-tooling',
    configuration: 'buildTimeInstrumentationToolingPlugins'
    ))
```

Before the normalizer, Gradle hashed the full jar contents of the
build-time instrumentation plugin classpath. And as such the jars on
that configuration changed only because their generated *.version
changed after a new Git commit. And as such invalidated the task output.

Adding the normalizer to this input only teaches Gradle to use the
normalizaton declared in the project to ignore the version file on
this input.

Important nuance: `ClasspathNormalizer` is better than
`CompileClasspathNormalizer` here. These are Byte Buddy plugins executed
at build time, so method-body/resource changes in those plugin jars
can change generated bytecode. We only want to ignore the known
volatile version resource.

---

Before this change the compile task amounted to a significant part when
only the commit version changed

```
327.901s  compile*
 10.486s  codenarcTest
  9.576s  *Jar
  8.217s  process*Resources
  2.208s  expandAgentShadowJar*
  2.032s  generate*Index
  1.241s  writeVersionNumberFile
```

After this change
```
14.780s  compile*              # up-to-date checking, not recompilation
 7.469s  process*Resources
 6.194s  *Jar
 5.056s  codenarcTest
 2.233s  writeVersionNumberFile
 1.847s  generate*Index
 0.899s  expandAgentShadowJar*
```

Co-authored-by: brice.dutheil <brice.dutheil@datadoghq.com>

Author: bric3

build.gradle.kts

@@ -66,6 +66,13 @@ val compileTask = tasks.register("compile")
 allprojects {
   group = "com.datadoghq"
 
+  normalization {
+    runtimeClasspath {
+      // Let's ignore only version files generated by dd-trace-java.version-file
+      ignore("**/*.version")
+    }
+  }
+
   if (isCI.isPresent) {
     layout.buildDirectory = providers.provider {
       val newProjectCIPath = projectDir.path.replace(

buildSrc/src/main/kotlin/datadog/gradle/plugin/instrument/BuildTimeInstrumentationPlugin.kt

@@ -3,6 +3,7 @@ package datadog.gradle.plugin.instrument
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.logging.Logging
+import org.gradle.api.tasks.ClasspathNormalizer
 import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.SourceSetContainer
 import org.gradle.api.tasks.compile.AbstractCompile
@@ -115,6 +116,8 @@ class BuildTimeInstrumentationPlugin : Plugin<Project> {
           BUILD_TIME_INSTRUMENTATION_PLUGIN_CONFIGURATION
         )
         inputs.files(project.configurations.named(BUILD_TIME_INSTRUMENTATION_PLUGIN_CONFIGURATION))
+          .withPropertyName(BUILD_TIME_INSTRUMENTATION_PLUGIN_CONFIGURATION)
+          .withNormalizer(ClasspathNormalizer::class.java)
 
         // Compute optional Java version.
         val match = Regex("compileMain_(.+)Java").matchEntire(compileTaskName)

buildSrc/src/main/kotlin/datadog/gradle/plugin/version/WriteVersionFilePlugin.kt

@@ -10,17 +10,8 @@ class WriteVersionFilePlugin : Plugin<Project> {
   override fun apply(target: Project) {
     target.pluginManager.apply("java")
 
-    val versionFileName = "${target.name}.version"
     val writeVersionFile = target.tasks.register<WriteVersionFile>("writeVersionNumberFile")
 
-    // Keep volatile generated version metadata from invalidating @Classpath consumers such as CodeNarc.
-    // https://docs.gradle.org/current/userguide/build_cache_concepts.html#runtime_classpath_normalization
-    target.normalization {
-      runtimeClasspath {
-        ignore(versionFileName)
-      }
-    }
-
     target.the<JavaPluginExtension>().sourceSets.named("main") {
       resources.srcDir(writeVersionFile)
     }

buildSrc/src/test/kotlin/datadog/gradle/plugin/version/WriteVersionFilePluginTest.kt

@@ -125,65 +125,6 @@ class WriteVersionFilePluginTest : VersionPluginsFixture() {
     assertThat(versionFile).doesNotExist()
   }
 
-  @Test
-  fun `generated version file is ignored in runtime classpath normalization`() {
-    writeSettings(
-      """
-      rootProject.name = "my-lib"
-      """
-    )
-    writeRootProject(
-      """
-      import org.gradle.api.DefaultTask
-      import org.gradle.api.file.ConfigurableFileCollection
-      import org.gradle.api.file.RegularFileProperty
-      import org.gradle.api.tasks.Classpath
-      import org.gradle.api.tasks.InputFiles
-      import org.gradle.api.tasks.OutputFile
-      import org.gradle.api.tasks.TaskAction
-
-      plugins {
-        id("dd-trace-java.version-file")
-      }
-
-      version = "1.2.3"
-
-      tasks.named<datadog.gradle.plugin.version.WriteVersionFile>("writeVersionNumberFile") {
-        gitHash.set(providers.gradleProperty("gitHash").orElse("abc12345"))
-      }
-
-      abstract class ClasspathProbe : DefaultTask() {
-        @get:InputFiles
-        @get:Classpath
-        val classpath: ConfigurableFileCollection = project.objects.fileCollection()
-
-        @get:OutputFile
-        val outputFile: RegularFileProperty = project.objects.fileProperty()
-
-        @TaskAction
-        fun probe() {
-          outputFile.get().asFile.writeText("probed")
-        }
-      }
-
-      tasks.register<ClasspathProbe>("classpathProbe") {
-        dependsOn("processResources")
-        classpath.from(sourceSets.main.get().runtimeClasspath)
-        outputFile.set(layout.buildDirectory.file("classpath-probe/output.txt"))
-      }
-      """
-    )
-
-    assertThat(run("classpathProbe", "-PgitHash=abc12345").task(":classpathProbe")?.outcome)
-      .isEqualTo(TaskOutcome.SUCCESS)
-
-    val result = run("classpathProbe", "-PgitHash=def67890")
-
-    assertThat(generatedVersionFile).hasContent("1.2.3~def67890")
-    assertThat(result.task(":writeVersionNumberFile")?.outcome).isEqualTo(TaskOutcome.SUCCESS)
-    assertThat(result.task(":classpathProbe")?.outcome).isEqualTo(TaskOutcome.UP_TO_DATE)
-  }
-
   private fun assertVersionFile(
     expectedContentRegex: String,
     task: String = ":writeVersionNumberFile",