Revert object state & mark as unshared

Author: szymon-rd

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -23,7 +23,20 @@ object ScalaSettingCategories:
   val AdvancedSetting = "X"
   val VerboseSetting = "V"
 
-object ScalaSettings:
+type ScalaSettings = ScalaSettings.type
+
+object ScalaSettings extends SettingGroup, AllScalaSettings:
+  val settingsByCategory: Map[String, List[Setting[_]]] = 
+    allSettings.groupBy(_.category)
+      .view.mapValues(_.toList).toMap
+      .withDefaultValue(Nil)
+  def categories: List[String] = settingsByCategory.keys.toList
+  val rootSettings: List[Setting[_]] = settingsByCategory(RootSetting)
+  val warningSettings: List[Setting[_]] = settingsByCategory(WarningSetting)
+  val forkSettings: List[Setting[_]] = settingsByCategory(ForkSetting)
+  val advancedSettings: List[Setting[_]] = settingsByCategory(AdvancedSetting)
+  val verboseSettings: List[Setting[_]] = settingsByCategory(VerboseSetting)
+  val settingsByAliases: Map[String, Setting[_]] = allSettings.flatMap(s => s.aliases.map(_ -> s)).toMap
 
   private lazy val minTargetVersion = classfileVersionMap.keysIterator.map(_.toInt).min
   private lazy val maxTargetVersion = classfileVersionMap.keysIterator.map(_.toInt).max
@@ -58,19 +71,6 @@ object ScalaSettings:
     else defaultWidth
   }
 
-class ScalaSettings extends SettingGroup, AllScalaSettings:
-  val settingsByCategory: Map[String, List[Setting[_]]] = 
-    allSettings.groupBy(_.category)
-      .view.mapValues(_.toList).toMap
-      .withDefaultValue(Nil)
-  def categories: List[String] = settingsByCategory.keys.toList
-  val rootSettings: List[Setting[_]] = settingsByCategory(RootSetting)
-  val warningSettings: List[Setting[_]] = settingsByCategory(WarningSetting)
-  val forkSettings: List[Setting[_]] = settingsByCategory(ForkSetting)
-  val advancedSettings: List[Setting[_]] = settingsByCategory(AdvancedSetting)
-  val verboseSettings: List[Setting[_]] = settingsByCategory(VerboseSetting)
-  val settingsByAliases: Map[String, Setting[_]] = allSettings.flatMap(s => s.aliases.map(_ -> s)).toMap
-
 trait AllScalaSettings extends CommonScalaSettings, PluginSettings, VerboseSettings, WarningSettings, XSettings, YSettings:
   self: SettingGroup =>
 

compiler/src/dotty/tools/dotc/config/Settings.scala

@@ -8,6 +8,7 @@ import core.Contexts.*
 import dotty.tools.io.{AbstractFile, Directory, JarArchive, PlainDirectory}
 
 import annotation.tailrec
+import annotation.internal.unshared
 import collection.mutable.ArrayBuffer
 import collection.mutable
 import reflect.ClassTag
@@ -240,6 +241,7 @@ object Settings:
 
   class SettingGroup {
 
+    @unshared
     private val _allSettings = new ArrayBuffer[Setting[?]]
     def allSettings: Seq[Setting[?]] = _allSettings.toSeq
 
@@ -307,6 +309,7 @@ object Settings:
       setting
     }
 
+    @unshared
     val settingCharacters = "[a-zA-Z0-9_\\-]*".r
     def validateSetting(setting: String): String =
       assert(settingCharacters.matches(setting), s"Setting $setting contains invalid characters")

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -861,7 +861,7 @@ object Contexts {
                        with Phases.PhasesBase
                        with Plugins {
 
-    val settings: ScalaSettings = new ScalaSettings()
+    val settings: ScalaSettings = ScalaSettings
 
     /** The initial context */
     val initialCtx: Context = FreshContext.initial(this: @unchecked, settings)

compiler/test/dotty/tools/dotc/ScalaCommandTest.scala

@@ -17,7 +17,7 @@ class ScalaCommandTest:
   def temporaryFolder = _temporaryFolder
 
   @Test def `Simple one parameter`: Unit = inContext {
-    val settings = new config.ScalaSettings()
+    val settings = config.ScalaSettings
     val args = "-cp path/to/classes1:other/path/to/classes2 files".split(" ")
     val summary = ScalacCommand.distill(args, settings)()
     given SettingsState = summary.sstate
@@ -26,7 +26,7 @@ class ScalaCommandTest:
   }
 
   @Test def `Unfold @file`: Unit = inContext {
-    val settings = new config.ScalaSettings()
+    val settings = config.ScalaSettings
     val file = temporaryFolder.newFile("config")
     val writer = java.io.FileWriter(file);
     writer.write("-sourceroot myNewRoot someMoreFiles");

compiler/test/dotty/tools/dotc/config/ScalaSettingsTests.scala

@@ -67,7 +67,7 @@ class ScalaSettingsTests:
 
   @Test def `WConf setting is parsed`: Unit =
     import reporting.{Action, Diagnostic, NoExplanation}
-    val sets = new ScalaSettings()
+    val sets = ScalaSettings
     val args = List("-Wconf:cat=deprecation:s,cat=feature:e", "-Wconf:msg=a problem\\.:s")
     val sumy = ArgsSummary(sets.defaultState, args, errors = Nil, warnings = Nil)
     val proc = sets.processArguments(sumy, processAll = true, skipped = Nil)
@@ -85,7 +85,7 @@ class ScalaSettingsTests:
 
   @Test def `i18367 rightmost WConf flags take precedence over flags to the left`: Unit =
     import reporting.{Action, Diagnostic}
-    val sets = new ScalaSettings()
+    val sets = ScalaSettings
     val args = List("-Wconf:cat=deprecation:e", "-Wconf:cat=deprecation:s")
     val sumy = ArgsSummary(sets.defaultState, args, errors = Nil, warnings = Nil)
     val proc = sets.processArguments(sumy, processAll = true, skipped = Nil)