[compiler] Instruct the JavaBuilder to not run without outright disabling it

#SCL-22172 fixed

- By providing a unique Java compiler id that does not match any Java compiler implementation in the platform, we are able to tell the JPS JavaBuilder to not run in Zinc Scala projects, without disabling it.
- This also prevents the disabling of the KotlinBuilder in Zinc Scala projects, although, we need to do a bit more work to make this fully supported, as Zinc does not guarantee incremental compilation support for Scala and Kotlin.
- This change prevents the disabling of the GradleResourcesBuilder in gradle Scala projects that use the Zinc incremental compiler.

Author: vasilmkd

scala/compiler-jps/src/org/jetbrains/jps/incremental/scala/InitialScalaBuilder.scala

@@ -7,6 +7,7 @@ import org.jetbrains.jps.builders.DirtyFilesHolder
 import org.jetbrains.jps.builders.java.{JavaBuilderUtil, JavaSourceRootDescriptor}
 import org.jetbrains.jps.builders.storage.BuildDataCorruptedException
 import org.jetbrains.jps.incremental._
+import org.jetbrains.jps.model.java.JpsJavaExtensionService
 import org.jetbrains.jps.model.module.JpsModule
 import org.jetbrains.plugins.scala.compiler.data.IncrementalityType
 
@@ -31,6 +32,21 @@ class InitialScalaBuilder extends ModuleLevelBuilder(BuilderCategory.INITIAL) {
       val previousIncrementalityType = readIncrementalityType(context)
       val incrementalityType = ScalaBuilder.projectSettings(context).getIncrementalityType
 
+      if (incrementalityType == IncrementalityType.SBT) {
+        // The project uses the Zinc incremental compiler. The Zinc incremental compiler compiles both Scala and Java
+        // sources. For that reason, it is important that the JavaBuilder does not run for our project. However,
+        // disabling the JavaBuilder through the JavaBuilder.IS_ENABLED global key is not ideal. There are other
+        // JPS builders who are also implicitly disabled by this action, such as the KotlinBuilder and the
+        // GradleResourcesBuilder. Thus, we want to instruct the JavaBuilder to not run for our project, but keep it
+        // enabled, such that the other builders can run. This can be achieved through the Java Compiler ID mechanism.
+        // We set the Java Compiler ID to our custom Zinc ID, an ID which is unique to the Scala plugin and for which
+        // a compiler does not exist in the IDEA Platform. In this case, the JavaBuilder will not have a compiler
+        // instance to run, and therefore it will not do anything in our project, but remain officially enabled.
+        val project = context.getProjectDescriptor.getProject
+        val configuration = JpsJavaExtensionService.getInstance().getCompilerConfiguration(project)
+        configuration.setJavaCompilerId(ZincCompilerId)
+      }
+
       previousIncrementalityType match {
         case _ if JavaBuilderUtil.isForcedRecompilationAllJavaModules(context) =>
           // Forced rebuild, save current incremental compiler setting to disk and continue.
@@ -156,4 +172,10 @@ object InitialScalaBuilder {
     storeScalaModules(context, result)
     result
   }
+
+  /**
+   * A unique compiler id (in the IntelliJ Platform), which does not match any other Java compiler implementation
+   * provided by the platform.
+   */
+  private final val ZincCompilerId = "scala_Zinc"
 }

scala/compiler-jps/src/org/jetbrains/jps/incremental/scala/SbtBuilder.scala

@@ -8,7 +8,6 @@ import org.jetbrains.jps.incremental.ModuleLevelBuilder.{ExitCode => JpsExitCode
 
 import java.io.File
 import org.jetbrains.jps.incremental._
-import org.jetbrains.jps.incremental.java.JavaBuilder
 import org.jetbrains.jps.incremental.messages.ProgressMessage
 import org.jetbrains.jps.incremental.scala.InitialScalaBuilder.isScalaProject
 import org.jetbrains.jps.incremental.scala.SbtBuilder._
@@ -24,12 +23,6 @@ import _root_.scala.jdk.CollectionConverters._
 class SbtBuilder extends ModuleLevelBuilder(BuilderCategory.TRANSLATOR) {
   override def getPresentableName: String = JpsBundle.message("sbt.builder.presentable.name")
 
-  override def buildStarted(context: CompileContext): Unit = {
-    if (isEnabled(context)) {
-      JavaBuilder.IS_ENABLED.set(context, false)
-    }
-  }
-
   override def build(context: CompileContext,
                      chunk: ModuleChunk,
                      dirtyFilesHolder: DirtyFilesHolder,