Use colon arg uniformly

src/compiler/scala/tools/nsc/settings/AbsSettings.scala

@@ -20,7 +20,7 @@ package settings
 
 trait AbsSettings extends scala.reflect.internal.settings.AbsSettings {
   type Setting <: AbsSetting      // Fix to the concrete Setting type
-  type ResultOfTryToSet           // List[String] in mutable, (Settings, List[String]) in immutable
+  type ResultOfTryToSet           // List[String] in MutableSettings
   def errorFn: String => Unit
   protected def allSettings: scala.collection.Map[String, Setting]
 
@@ -66,14 +66,6 @@ trait AbsSettings extends scala.reflect.internal.settings.AbsSettings {
     /* For tools which need to populate lists of available choices */
     def choices : List[String] = Nil
 
-    /** In mutable Settings, these return the same object with a var set.
-     *  In immutable, of course they will return a new object, which means
-     *  we can't use "this.type", at least not in a non-casty manner, which
-     *  is unfortunate because we lose type information without it.
-     *
-     *  ...but now they're this.type because of scala/bug#3462.  The immutable
-     *  side doesn't exist yet anyway.
-     */
     def withAbbreviation(name: String): this.type
     def withHelpSyntax(help: String): this.type
     def withDeprecationMessage(msg: String): this.type
@@ -101,19 +93,17 @@ trait AbsSettings extends scala.reflect.internal.settings.AbsSettings {
     /** The help message to be printed if [[isHelping]]. */
     def help: String = ""
 
-    /** After correct Setting has been selected, tryToSet is called with the
-     *  remainder of the command line.  It consumes any applicable arguments and
-     *  returns the unconsumed ones.
+    /** Setting is presented the remaining command line arguments.
+     *  It should consume any applicable args and return the rest,
+     *  or `None` on error.
      */
     protected[nsc] def tryToSet(args: List[String]): Option[ResultOfTryToSet]
 
-    /** Commands which can take lists of arguments in form -Xfoo:bar,baz override
-     *  this method and accept them as a list.  It returns List[String] for
-     *  consistency with tryToSet, and should return its incoming arguments
-     *  unmodified on failure, and Nil on success.
+    /** Setting is presented arguments in form -Xfoo:bar,baz.
+     *  It should consume all the arguments and return an empty list,
+     *  or `None` on error. Unconsumed args may error.
      */
-    protected[nsc] def tryToSetColon(args: List[String]): Option[ResultOfTryToSet] =
-      errorAndValue(s"'$name' does not accept multiple arguments", None)
+    protected[nsc] def tryToSetColon(args: List[String]): Option[ResultOfTryToSet]
 
     /** Attempt to set from a properties file style property value.
      *  Currently used by Eclipse SDT only.

src/compiler/scala/tools/nsc/settings/MutableSettings.scala

@@ -398,11 +398,19 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
 
     def errorMsg() = errorFn(s"invalid setting for $name $getValidText")
 
-    def tryToSet(args: List[String]) =
-      if (args.isEmpty) errorAndValue("missing argument", None)
-      else parseArgument(args.head) match {
-        case Some(i)  => value = i ; Some(args.tail)
-        case None     => errorMsg() ; None
+    def tryToSet(args: List[String]): Option[ResultOfTryToSet] =
+      args match {
+        case h :: rest =>
+          parseArgument(h) match {
+            case Some(i) => value = i; Some(rest)
+            case None    => errorMsg(); None
+          }
+        case Nil => errorAndValue("missing argument", None)
+      }
+    def tryToSetColon(args: List[String]): Option[ResultOfTryToSet] =
+      args match {
+        case Nil | _ :: Nil => tryToSet(args)
+        case _              => errorAndValue("too many arguments", None)
       }
 
     def unparse: List[String] =
@@ -452,6 +460,7 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
       case _  =>
         None
     }
+    def tryToSetColon(args: List[String]): Option[ResultOfTryToSet] = errorAndValue(s"bad argument for $name", None)
     override def respondsTo(token: String) = token startsWith prefix
     def unparse: List[String] = value
   }
@@ -475,6 +484,11 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
       case "help" :: rest if helpText.nonEmpty => sawHelp = true ; Some(rest)
       case h :: rest                           => value = h ; Some(rest)
     }
+    def tryToSetColon(args: List[String]): Option[ResultOfTryToSet] =
+      args match {
+        case Nil | _ :: Nil => tryToSet(args)
+        case _              => errorAndValue("too many arguments", None)
+      }
     def unparse: List[String] = if (value == default) Nil else List(name, value)
 
     override def isHelping: Boolean = sawHelp
@@ -498,15 +512,15 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
 
     // This method is invoked if there are no colonated args. In this case the default value is
     // used. No arguments are consumed.
-    override def tryToSet(args: List[String]) = {
+    def tryToSet(args: List[String]) = {
       default match {
         case Some(d) => value = d
         case None => errorFn(s"$name requires an argument, the syntax is $helpSyntax")
       }
       Some(args)
     }
 
-    override def tryToSetColon(args: List[String]) = args match {
+    def tryToSetColon(args: List[String]) = args match {
       case x :: xs  => value = ScalaVersion(x, errorFn); Some(xs)
       case nil      => Some(nil)
     }
@@ -678,7 +692,7 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
     }
 
     def tryToSet(args: List[String])                  = tryToSetArgs(args, halting = true)
-    override def tryToSetColon(args: List[String])    = tryToSetArgs(args, halting = false)
+    def tryToSetColon(args: List[String])    = tryToSetArgs(args, halting = false)
     override def tryToSetFromPropertyValue(s: String) = tryToSet(s.trim.split(',').toList) // used from ide
 
     /** Try to set args, handling "help" and default.
@@ -805,7 +819,7 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
       Some(rest)
     }
     def tryToSet(args: List[String])                  = tryToSetArgs(args, halting = true)
-    override def tryToSetColon(args: List[String])    = tryToSetArgs(args, halting = false)
+    def tryToSetColon(args: List[String])    = tryToSetArgs(args, halting = false)
     override def tryToSetFromPropertyValue(s: String) = tryToSet(s.trim.split(',').toList) // used from ide
 
     def clear(): Unit         = (v = Nil)
@@ -851,9 +865,13 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
     override def isHelping = sawHelp
     override def help = usageErrorMessage
 
-    def tryToSet(args: List[String]) = errorAndValue(usageErrorMessage, None)
+    def tryToSet(args: List[String]) =
+      args match {
+        case Nil | Optionlike() :: _ => errorAndValue(usageErrorMessage, None)
+        case arg :: rest             => tryToSetColon(List(arg)).map(_ => rest)
+      }
 
-    override def tryToSetColon(args: List[String]) = args map _preSetHook match {
+    def tryToSetColon(args: List[String]) = args map _preSetHook match {
       case Nil                            => errorAndValue(usageErrorMessage, None)
       case List("help")                   => sawHelp = true; SomeOfNil
       case List(x) if choices contains x  => value = x ; SomeOfNil
@@ -916,7 +934,7 @@ class MutableSettings(val errorFn: String => Unit, val pathFactory: PathFactory)
 
     private def splitDefault = default.split(',').toList
 
-    override def tryToSetColon(args: List[String]) = try {
+    def tryToSetColon(args: List[String]) = try {
       args match {
         case Nil  => if (default == "") errorAndValue("missing phase", None)
                      else tryToSetColon(splitDefault)

test/files/neg/t12543.check

@@ -0,0 +1,4 @@
+t12543.scala:10: error: value of is not a member of object java.util.List
+    val ss = java.util.List.of("Hello", who)
+                            ^
+1 error

test/files/neg/t12543.scala

@@ -0,0 +1,17 @@
+
+// scalac: -Werror -release 8
+
+import scala.jdk.CollectionConverters._
+//import jdk.CollectionConverters._  // scala/bug/issues/12566
+import sun._
+
+object HelloWorld {
+  def main(args: Array[String]) = {
+    val ss = java.util.List.of("Hello", who)
+    println(ss.asScala.mkString("", ", ", "!"))
+  }
+}
+
+object sun {
+  val who = "world"
+}