Remove custom best effort directory path

backend/src/main/scala/bloop/BloopClassFileManager.scala

@@ -214,17 +214,34 @@ final class BloopClassFileManager(
         ) => {
           clientTracer.traceTaskVerbose("copy new products to external classes dir") { _ =>
             val config = ParallelOps.CopyConfiguration(5, CopyMode.ReplaceExisting, Set.empty)
-            ParallelOps
-              .copyDirectories(config)(
-                newClassesDir,
-                clientExternalClassesDir.underlying,
-                inputs.ioScheduler,
-                enableCancellation = false
-              )
-              .map { walked =>
-                readOnlyCopyDenylist.++=(walked.target)
+            val clientExternalBestEffortDir =
+              clientExternalClassesDir.underlying.resolve("META-INF/best-effort")
+
+            // Deletes all previous best-effort artifacts to get rid of all of the outdated ones.
+            // Since best effort compilation is not affected by incremental compilation,
+            // all relevant files are always produced by the compiler. Because of this,
+            // we can always delete all previous files and copy newly created ones
+            // without losing anything in the process.
+            val deleteClientExternalBestEffortDir =
+              Task {
+                if (Files.exists(clientExternalBestEffortDir)) {
+                  BloopPaths.delete(AbsolutePath(clientExternalBestEffortDir))
+                }
                 ()
-              }
+              }.memoize
+
+            deleteClientExternalBestEffortDir *>
+              ParallelOps
+                .copyDirectories(config)(
+                  newClassesDir,
+                  clientExternalClassesDir.underlying,
+                  inputs.ioScheduler,
+                  enableCancellation = false
+                )
+                .map { walked =>
+                  readOnlyCopyDenylist.++=(walked.target)
+                  ()
+                }
           }
         }
       )

backend/src/main/scala/bloop/CompileProducts.scala

@@ -32,7 +32,6 @@ import xsbti.compile.PreviousResult
 case class CompileProducts(
     readOnlyClassesDir: Path,
     newClassesDir: Path,
-    bestEffortDepDir: Option[Path],
     resultForDependentCompilationsInSameRun: PreviousResult,
     resultForFutureCompilationRuns: PreviousResult,
     invalidatedCompileProducts: Set[File],

backend/src/main/scala/bloop/Compiler.scala

@@ -22,7 +22,6 @@ import bloop.reporter.ZincReporter
 import bloop.task.Task
 import bloop.tracing.BraveTracer
 import bloop.util.AnalysisUtils
-import bloop.util.BestEffortDirs
 import bloop.util.CacheHashCode
 import bloop.util.UUIDUtil
 
@@ -71,7 +70,6 @@ case class CompileOutPaths(
     analysisOut: AbsolutePath,
     genericClassesDir: AbsolutePath,
     externalClassesDir: AbsolutePath,
-    bestEffortDirs: Option[BestEffortDirs],
     internalReadOnlyClassesDir: AbsolutePath
 ) {
   // Don't change the internals of this method without updating how they are cleaned up
@@ -229,7 +227,7 @@ object Compiler {
       compileInputs: CompileInputs,
       isBestEffortMode: Boolean,
       isBestEffortDep: Boolean
-  ): Task[Result] = { // TODO improve
+  ): Task[Result] = {
     val logger = compileInputs.logger
     val tracer = compileInputs.tracer
     val compileOut = compileInputs.out
@@ -240,9 +238,6 @@ object Compiler {
     val readOnlyClassesDirPath = readOnlyClassesDir.toString
     val newClassesDir = compileOut.internalNewClassesDir.underlying
     val newClassesDirPath = newClassesDir.toString
-    val bestEffortBuildDir = compileOut.bestEffortDirs.map(_.buildDir.underlying)
-    val bestEffortDepDir = compileOut.bestEffortDirs.map(_.depDir.underlying)
-    bestEffortBuildDir.foreach(dir => if (!Files.exists(dir)) Files.createDirectories(dir))
 
     logger.debug(s"External classes directory ${externalClassesDirPath}")
     logger.debug(s"Read-only classes directory ${readOnlyClassesDirPath}")
@@ -385,7 +380,7 @@ object Compiler {
       clientTracer.traceTaskVerbose(descriptionMsg) { _ =>
         Task.defer {
           clientLogger.debug(descriptionMsg)
-          val denyList = 
+          val denyList =
             if (invalidate) {
               val invalidatedClassFiles =
                 allInvalidatedClassFilesForProject.iterator.map(_.toPath).toSet
@@ -446,7 +441,7 @@ object Compiler {
       .doOnCancel(Task(cancel()))
       .map {
         case Success(_) if cancelPromise.isCompleted => handleCancellation
-        case Success(result) if isBestEffortMode && isBestEffortDep =>
+        case Success(_) if isBestEffortMode && isBestEffortDep =>
           handleBestEffortSuccess(
             compileInputs,
             compileOut,
@@ -462,7 +457,8 @@ object Compiler {
             None
           )
         case Failure(cause: xsbti.CompileFailed) if isBestEffortMode =>
-          // copies required files to a bsp directory !!!
+          // Copies required files to a bsp directory.
+          // For the Success case this is done by the enclosing method
           fileManager.complete(true)
           handleBestEffortSuccess(
             compileInputs,
@@ -515,7 +511,6 @@ object Compiler {
             val products = CompileProducts(
               readOnlyClassesDir,
               readOnlyClassesDir,
-              bestEffortDepDir,
               noOpPreviousResult,
               noOpPreviousResult,
               Set(),
@@ -531,7 +526,12 @@ object Compiler {
               ): Task[Unit] = Task.defer {
                 clientLogger.debug(s"Triggering background tasks for $clientClassesDir")
                 val updateClientState =
-                  updateExternalClassesDirWithReadOnly(clientClassesDir, clientTracer, clientLogger, true)
+                  updateExternalClassesDirWithReadOnly(
+                    clientClassesDir,
+                    clientTracer,
+                    clientLogger,
+                    true
+                  )
 
                 val writeAnalysisIfMissing = {
                   if (compileOut.analysisOut.exists) Task.unit
@@ -544,16 +544,7 @@ object Compiler {
                 }
 
                 val deleteNewClassesDir = Task(BloopPaths.delete(AbsolutePath(newClassesDir)))
-                val deleteBestEffortDirsTasks = compileOut.bestEffortDirs match {
-                  case Some(BestEffortDirs(buildDir, depDir)) =>
-                    List(Task(BloopPaths.delete(buildDir)), Task(BloopPaths.delete(depDir)))
-                  case None => List(Task.unit)
-                }
-                val allTasks = List(
-                  deleteNewClassesDir,
-                  updateClientState,
-                  writeAnalysisIfMissing
-                ) ++ deleteBestEffortDirsTasks
+                val allTasks = List(deleteNewClassesDir, updateClientState, writeAnalysisIfMissing)
                 Task
                   .gatherUnordered(allTasks)
                   .map(_ => ())
@@ -633,14 +624,8 @@ object Compiler {
                       }
                     }
                   }
-                  val deleteBestEffortDirsTasks =
-                    compileOut.bestEffortDirs match { // TODO duplicate
-                      case Some(BestEffortDirs(buildDir, depDir)) =>
-                        List(Task(BloopPaths.delete(buildDir)), Task(BloopPaths.delete(depDir)))
-                      case None => List(Task.unit)
-                    }
                   Task
-                    .gatherUnordered(List(firstTask, secondTask) ++ deleteBestEffortDirsTasks)
+                    .gatherUnordered(List(firstTask, secondTask))
                     .map(_ => ())
                 }
 
@@ -651,7 +636,6 @@ object Compiler {
             val products = CompileProducts(
               readOnlyClassesDir,
               newClassesDir,
-              bestEffortDepDir,
               resultForDependentCompilationsInSameRun,
               resultForFutureCompilationRuns,
               allInvalidated.toSet,
@@ -681,13 +665,6 @@ object Compiler {
                 toBackgroundTasks(backgroundTasksForFailedCompilation.toList)
               Result.Failed(failedProblems, None, elapsed, backgroundTasks, None)
             case t: Throwable =>
-              compileOut.bestEffortDirs.foreach {
-                case BestEffortDirs(buildDir, _) =>
-                  logger.info(
-                    "Unsuccessful best effort compilation. No best effort artifacts were created."
-                  )
-                  BloopPaths.delete(buildDir)
-              }
               t.printStackTrace()
               val backgroundTasks =
                 toBackgroundTasks(backgroundTasksForFailedCompilation.toList)
@@ -698,7 +675,7 @@ object Compiler {
 
   /**
    * Handles successful Best Effort compilation.
-   * Does not persist incrementalCompilation analysis.
+   * Does not persist incremental compilation analysis.
    */
   def handleBestEffortSuccess(
       compileInputs: CompileInputs,
@@ -720,7 +697,6 @@ object Compiler {
     val readOnlyClassesDir = compileOut.internalReadOnlyClassesDir.underlying
     val readOnlyClassesDirPath = readOnlyClassesDir.toString
     val newClassesDir = compileOut.internalNewClassesDir.underlying
-    val bestEffortBuildDir = compileOut.bestEffortDirs.map(_.buildDir.underlying)
     val sourcesWithFatal = reporter.getSourceFilesWithFatalWarnings
     val reportedFatalWarnings = isFatalWarningsEnabled && sourcesWithFatal.nonEmpty
     val code = if (reportedFatalWarnings) bsp.StatusCode.Error else bsp.StatusCode.Ok
@@ -732,47 +708,20 @@ object Compiler {
       Some(compileOut.analysisOut)
     )
 
-    // TODO remove
-    val products = compileOut.bestEffortDirs.map {
-      case BestEffortDirs(buildDir, depDir) =>
-        // For Best Effort, delete previous dep directory contents and update with new ones
-        if (Files.exists(depDir.underlying)) BloopPaths.delete(depDir)
-        if (!Files.exists(depDir.underlying)) Files.createDirectories(depDir.underlying)
-        java.nio.file.Files
-          .walk(buildDir.underlying)
-          .forEach { srcFile =>
-            val targetFile =
-              depDir.underlying.resolve(buildDir.underlying.relativize(srcFile))
-            if (Files.isDirectory(srcFile)) {
-              logger.info("copying " + srcFile)
-              Files.createDirectories(targetFile)
-            } else if (Files.isRegularFile(srcFile)) {
-              logger.info("copying file  " + srcFile)
-              Files.copy(
-                srcFile,
-                targetFile,
-                java.nio.file.StandardCopyOption.REPLACE_EXISTING
-              )
-            }
-          }
-        BloopPaths.delete(buildDir)
-
-        val noOpPreviousResult =
-          updatePreviousResultWithRecentClasspathHashes(
-            compileInputs.previousResult,
-            uniqueInputs
-          )
+    val noOpPreviousResult =
+      updatePreviousResultWithRecentClasspathHashes(
+        compileInputs.previousResult,
+        uniqueInputs
+      )
 
-        CompileProducts(
-          readOnlyClassesDir,
-          newClassesDir,
-          bestEffortBuildDir,
-          noOpPreviousResult,
-          noOpPreviousResult,
-          Set.empty,
-          Map.empty
-        )
-    }.get
+    val products = CompileProducts(
+      readOnlyClassesDir,
+      newClassesDir,
+      noOpPreviousResult,
+      noOpPreviousResult,
+      Set.empty,
+      Map.empty
+    )
 
     // Delete all those class files that were invalidated in the external classes dir
     val allInvalidated =

frontend/src/it/scala/bloop/CommunityBuild.scala

@@ -132,7 +132,7 @@ abstract class CommunityBuild(val buildpressHomeDir: AbsolutePath) {
         resources = Nil,
         compileSetup = Config.CompileSetup.empty,
         genericClassesDir = dummyClassesDir,
-        bestEffortDirs = None,
+        isBestEffort = false,
         scalacOptions = Nil,
         javacOptions = Nil,
         sources = Nil,

frontend/src/main/scala/bloop/bsp/BloopBspServices.scala

@@ -793,8 +793,7 @@ final class BloopBspServices(
               fullClasspath.toList,
               javaOptions,
               workingDirectory,
-              environmentVariables,
-              None
+              environmentVariables
             )
           }).toList
           Task.now((state, Right(environmentEntries)))
@@ -1261,10 +1260,7 @@ final class BloopBspServices(
               target = target,
               options = project.scalacOptions.toList,
               classpath = classpath,
-              classDirectory = classesDir,
-              bestEffortDirectory = project.bestEffortDirs.map(bestEffortDirs =>
-                bsp.Uri(bestEffortDirs.depDir.toBspUri)
-              )
+              classDirectory = classesDir
             )
         }.toList
       )

frontend/src/main/scala/bloop/data/Project.scala

@@ -24,7 +24,6 @@ import bloop.io.ByteHasher
 import bloop.logging.DebugFilter
 import bloop.logging.Logger
 import bloop.task.Task
-import bloop.util.BestEffortDirs
 
 import com.typesafe.config.ConfigException
 import com.typesafe.config.ConfigFactory
@@ -44,7 +43,7 @@ final case class Project(
     resources: List[AbsolutePath],
     compileSetup: Config.CompileSetup,
     genericClassesDir: AbsolutePath,
-    bestEffortDirs: Option[BestEffortDirs],
+    isBestEffort: Boolean,
     scalacOptions: List[String],
     javacOptions: List[String],
     sources: List[AbsolutePath],
@@ -378,7 +377,7 @@ object Project {
       compileResources,
       setup,
       AbsolutePath(project.classesDir),
-      None,
+      false,
       scala.map(_.options).getOrElse(Nil),
       project.java.map(_.options).getOrElse(Nil),
       project.sources.map(AbsolutePath.apply),
@@ -441,9 +440,6 @@ object Project {
       logger: Logger
   ): Project = {
     val workspaceDir = project.workspaceDirectory.getOrElse(configDir.getParent)
-    val bestEffortBaseDir = project.genericClassesDir.getParent.resolve("best-effort")
-    val bestEffortBuildDir = bestEffortBaseDir.resolve("build")
-    val bestEffortDepDir = bestEffortBaseDir.resolve("dep")
     val isDotty = project.scalaInstance.exists(_.isDotty)
 
     def isAtLeastScala3M3(version: String) = {
@@ -457,13 +453,11 @@ object Project {
     }
 
     def enableBestEffortFlag(options: List[String]): List[String] = {
-      val bestEffortDirOpt = "-Ybest-effort-dir"
+      val bestEffortOpt = "-Ybest-effort"
       val withBETastyOpt = "-Ywith-best-effort-tasty"
-      if (!Files.exists(bestEffortBaseDir.underlying))
-        Files.createDirectories(bestEffortBaseDir.underlying)
       val optsWithDir =
-        if (options.exists(opt => opt.startsWith(bestEffortDirOpt))) options
-        else options ++ List(bestEffortDirOpt, bestEffortBuildDir.toString)
+        if (options.contains(bestEffortOpt)) options
+        else options :+ bestEffortOpt
       val optsWithBETasty =
         if (optsWithDir.contains(withBETastyOpt)) optsWithDir
         else options :+ withBETastyOpt
@@ -576,7 +570,7 @@ object Project {
         val options = enableBestEffortFlag(withEnabledJavaSemanticDb.scalacOptions)
 
         project.copy(
-          bestEffortDirs = Some(BestEffortDirs(bestEffortBuildDir, bestEffortDepDir)),
+          isBestEffort = true,
           scalacOptions = options
         )
       } else withEnabledJavaSemanticDb

frontend/src/main/scala/bloop/engine/caches/ResultsCache.scala

@@ -255,7 +255,6 @@ object ResultsCache {
                         CompileProducts(
                           classesDir,
                           classesDir,
-                          p.bestEffortDirs.map(_.buildDir.underlying),
                           r,
                           r,
                           Set.empty,