Clean up the PR

Author: szymon-rd

Diff for: compiler/src/dotty/tools/backend/jvm/BackendUtils.scala

@@ -186,4 +186,4 @@ object BackendUtils {
     "21" -> asm.Opcodes.V21,
     "22" -> asm.Opcodes.V22,
   )
-}
+}

Diff for: compiler/src/dotty/tools/dotc/Driver.scala

@@ -10,7 +10,6 @@ import dotty.tools.io.AbstractFile
 import reporting.*
 import core.Decorators.*
 import config.Feature
-import dotty.tools.dotc.config.ScalaSettings
 
 import scala.util.control.NonFatal
 import fromtasty.{TASTYCompiler, TastyFileUtil}

Diff for: compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -298,8 +298,8 @@ private sealed trait WarningSettings:
   val Wshadow: Setting[List[ChoiceWithHelp[String]]] = MultiChoiceHelpSetting(
     WarningSetting,
     name = "Wshadow",
-    helpArg = "advanced warning",
-    descr = "Enable or disable specific `lint` warnings",
+    helpArg = "warning",
+    descr = "Enable or disable specific `shadow` warnings",
     choices = List(
       ChoiceWithHelp("all", ""),
       ChoiceWithHelp("private-shadow", "Warn if a private field or class parameter shadows a superclass field"),
@@ -358,7 +358,7 @@ private sealed trait XSettings:
   val XmacroSettings: Setting[List[String]] = MultiStringSetting(AdvancedSetting, "Xmacro-settings", "setting1,setting2,..settingN", "List of settings which exposed to the macros")
 
   // Deprecated
-  val Xlint: Setting[_] = DeprecatedSetting(AdvancedSetting, "Xlint", "Enable or disable specific warnings", "Use -Wshadow to enable shadowing lints or -W:<opt> to enable specific sets of warnings.")
+  val Xlint: Setting[_] = DeprecatedSetting(AdvancedSetting, "Xlint", "Enable or disable specific warnings", "Use -Wshadow to enable shadowing lints.")
 
 end XSettings
 

Diff for: compiler/src/dotty/tools/dotc/config/Settings.scala

@@ -77,7 +77,7 @@ object Settings:
 
 
     assert(name.startsWith(s"-$category"), s"Setting $name does not start with category -$category")
-    assert(!choices.contains(""), s"Empty string is not supported as a choice for setting $name")
+    assert(legacyArgs || !choices.exists(_.contains("")), s"Empty string is not supported as a choice for setting $name")
     // Without the following assertion, it would be easy to mistakenly try to pass a file to a setting that ignores invalid args.
     // Example: -opt Main.scala would be interpreted as -opt:Main.scala, and the source file would be ignored.
     assert(!(summon[ClassTag[T]] == ListTag && ignoreInvalidArgs), s"Ignoring invalid args is not supported for multivalue settings: $name")