Handle -Ykind-projector as legacy option

Author: szymon-rd

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

@@ -71,7 +71,9 @@ object Settings:
     depends: List[(Setting[?], Any)] = Nil,
     ignoreInvalidArgs: Boolean = false,
     propertyClass: Option[Class[?]] = None,
-    deprecationMsg: Option[String] = None)(private[Settings] val idx: Int) {
+    deprecationMsg: Option[String] = None,
+    // kept only for -Ykind-projector option compatibility
+    legacyArgs: Boolean = false)(private[Settings] val idx: Int) {
 
 
     assert(name.startsWith(s"-$category"), s"Setting $name does not start with category -$category")
@@ -188,7 +190,7 @@ object Settings:
           case (OptionTag, _) =>
             update(Some(propertyClass.get.getConstructor().newInstance()), args)
           case (ct, args) =>
-            val argInArgRest = !argRest.isEmpty
+            val argInArgRest = !argRest.isEmpty || (legacyArgs && choices.exists(_.contains("")))
             val argAfterParam = !argInArgRest && args.nonEmpty && (ct == IntTag || !args.head.startsWith("-"))
             if argInArgRest then
               doSetArg(argRest, args)
@@ -336,6 +338,10 @@ object Settings:
     def ChoiceSetting(category: String, name: String, helpArg: String, descr: String, choices: List[String], default: String, aliases: List[String] = Nil): Setting[String] =
       publish(Setting(category, validateAndPrependName(name), descr, default, helpArg, Some(choices), aliases = aliases.map(validateSetting)))
 
+    // Allows only args after :, but supports empty string as a choice. Used for -Ykind-projector
+    def LegacyChoiceSetting(category: String, name: String, helpArg: String, descr: String, choices: List[String], default: String, aliases: List[String] = Nil): Setting[String] =
+      publish(Setting(category, validateAndPrependName(name), descr, default, helpArg, Some(choices), aliases = aliases.map(validateSetting), legacyArgs = true))
+
     def MultiChoiceSetting(category: String, name: String, helpArg: String, descr: String, choices: List[String], default: List[String], aliases: List[String] = Nil): Setting[List[String]] =
       publish(Setting(category, validateAndPrependName(name), descr, default, helpArg, Some(choices), aliases = aliases.map(validateSetting)))
 

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

@@ -51,7 +51,7 @@ class TastyBootstrapTests {
         Properties.compilerInterface, Properties.scalaLibrary, Properties.scalaAsm,
         Properties.dottyInterfaces, Properties.jlineTerminal, Properties.jlineReader,
       ).mkString(File.pathSeparator),
-      Array("-Ycheck-reentrant", "-Ylog:checkReentrant+", "-language:postfixOps", "-Xsemanticdb")
+      Array("-Ycheck-reentrant", "-language:postfixOps", "-Xsemanticdb")
     )
 
     val libraryDirs = List(Paths.get("library/src"), Paths.get("library/src-bootstrapped"))

tests/neg/kind-projector.scala

@@ -1,4 +1,4 @@
-//> using options -Ykind-projector:enable
+//> using options -Ykind-projector
 
 package kind_projector_neg
 

tests/pos/kind-projector.scala

@@ -1,4 +1,4 @@
-//> using options -Ykind-projector:enable
+//> using options -Ykind-projector
 
 package kind_projector