Allow all settings to be helping

4 files changed, 11 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/CompilerCommand.scala b/src/compiler/scala/tools/nsc/CompilerCommand.scala
index 9b8e9fa330..3879d7b425 100644
--- a/src/compiler/scala/tools/nsc/CompilerCommand.scala
+++ b/src/compiler/scala/tools/nsc/CompilerCommand.scala
@@ -107,7 +107,7 @@ class CompilerCommand(arguments: List[String], val settings: Settings) {
     else {
       val sb = new StringBuilder
       allSettings foreach {
-        case s: MultiChoiceSetting[_] if s.isHelping => sb append s.help
+        case s if s.isHelping => sb append s.help
         case _ =>
       }
       sb.toString
diff --git a/src/compiler/scala/tools/nsc/settings/AbsSettings.scala b/src/compiler/scala/tools/nsc/settings/AbsSettings.scala
index 060a24d8d4..08fa56d8e9 100644
--- a/src/compiler/scala/tools/nsc/settings/AbsSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/AbsSettings.scala
@@ -88,6 +88,12 @@ trait AbsSettings extends scala.reflect.internal.settings.AbsSettings {
     /** Issue error and return */
     def errorAndValue[T](msg: String, x: T): T = { errorFn(msg) ; x }
 
+    /** If this method returns true, print the [[help]] message and exit. */
+    def isHelping: Boolean = false
+
+    /** 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.
diff --git a/src/compiler/scala/tools/nsc/settings/MutableSettings.scala b/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
index 9cc8faf8c2..45b21f6126 100644
--- a/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
@@ -748,9 +748,9 @@ class MutableSettings(val errorFn: String => Unit)
 
     def contains(choice: domain.Value): Boolean = value contains choice
 
-    def isHelping: Boolean = sawHelp
+    override def isHelping: Boolean = sawHelp
 
-    def help: String = {
+    override def help: String = {
       val choiceLength = choices.map(_.length).max + 1
       val formatStr = s"  %-${choiceLength}s %s"
       choices.zipAll(descriptions, "", "").map {
diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
index dae8539c66..6a164f0e1d 100644
--- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
@@ -38,8 +38,8 @@ trait ScalaSettings extends AbsScalaSettings
   /** If any of these settings is enabled, the compiler should print a message and exit.  */
   def infoSettings = List[Setting](version, help, Xhelp, Yhelp, showPlugins, showPhases, genPhaseGraph)
 
-  /** Any -multichoice:help? Nicer if any option could report that it had help to offer. */
-  private def multihelp = allSettings exists { case s: MultiChoiceSetting[_] => s.isHelping case _ => false }
+  /** Any -option:help? */
+  private def multihelp = allSettings exists { case s => s.isHelping case _ => false }
 
   /** Is an info setting set? */
   def isInfo = (infoSettings exists (_.isSetByUser)) || multihelp