-Ystatistics accepts a list of phases, cleanups in MultiChoiceSetting

MultiChoiceSetting and Xlint with its deprecated aliases is now a bit
simpler, but there's still room for improvement, as noted in comments.

9 files changed, 192 insertions, 163 deletions

diff --git a/src/compiler/scala/tools/nsc/Global.scala b/src/compiler/scala/tools/nsc/Global.scala
index 82ffb35c3f..452081cff1 100644
--- a/src/compiler/scala/tools/nsc/Global.scala
+++ b/src/compiler/scala/tools/nsc/Global.scala
@@ -1372,7 +1372,7 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
           runCheckers()
 
         // output collected statistics
-        if (settings.Ystatistics)
+        if (settings.YstatisticsEnabled)
           statistics.print(phase)
 
         advancePhase()
diff --git a/src/compiler/scala/tools/nsc/MainBench.scala b/src/compiler/scala/tools/nsc/MainBench.scala
index 03190a63f3..eb56c8a230 100644
--- a/src/compiler/scala/tools/nsc/MainBench.scala
+++ b/src/compiler/scala/tools/nsc/MainBench.scala
@@ -24,7 +24,7 @@ object MainBench extends Driver with EvalLoop {
     var start = System.nanoTime()
     for (i <- 0 until NIter) {
       if (i == NIter-1) {
-        theCompiler.settings.Ystatistics.value = true
+        theCompiler.settings.YstatisticsPhases.value = theCompiler.settings.YstatisticsPhases.default.get
         Statistics.enabled = true
       }
       process(args)
diff --git a/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala b/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
index 8df3969c49..351eb23c4c 100644
--- a/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
+++ b/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
@@ -283,7 +283,7 @@ abstract class Inliners extends SubComponent {
       }
 
     val tfa   = new analysis.MTFAGrowable()
-    tfa.stat  = global.settings.Ystatistics.value
+    tfa.stat  = global.settings.YstatisticsEnabled
     val staleOut      = new mutable.ListBuffer[BasicBlock]
     val splicedBlocks = mutable.Set.empty[BasicBlock]
     val staleIn       = mutable.Set.empty[BasicBlock]
diff --git a/src/compiler/scala/tools/nsc/settings/AbsScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/AbsScalaSettings.scala
index d0b8fd70ed..cd2cb183b3 100644
--- a/src/compiler/scala/tools/nsc/settings/AbsScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/AbsScalaSettings.scala
@@ -29,7 +29,7 @@ trait AbsScalaSettings {
   def ChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], default: String): ChoiceSetting
   def IntSetting(name: String, descr: String, default: Int, range: Option[(Int, Int)], parser: String => Option[Int]): IntSetting
   def MultiStringSetting(name: String, helpArg: String, descr: String): MultiStringSetting
-  def MultiChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], default: Option[() => Unit])(helper: MultiChoiceSetting => String): MultiChoiceSetting
+  def MultiChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], descriptions: List[String], default: Option[List[String]]): MultiChoiceSetting
   def OutputSetting(outputDirs: OutputDirs, default: String): OutputSetting
   def PathSetting(name: String, descr: String, default: String): PathSetting
   def PhasesSetting(name: String, descr: String, default: String): PhasesSetting
diff --git a/src/compiler/scala/tools/nsc/settings/MutableSettings.scala b/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
index f26192f88a..b9b9257d63 100644
--- a/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/MutableSettings.scala
@@ -209,12 +209,11 @@ class MutableSettings(val errorFn: String => Unit)
   def BooleanSetting(name: String, descr: String) = add(new BooleanSetting(name, descr))
   def ChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], default: String) =
     add(new ChoiceSetting(name, helpArg, descr, choices, default))
-  def IntSetting(name: String, descr: String, default: Int, range: Option[(Int, Int)], parser: String => Option[Int]) = add(new IntSetting(name, descr, default, range, parser))
+  def IntSetting(name: String, descr: String, default: Int, range: Option[(Int, Int)], parser: String => Option[Int]) =
+    add(new IntSetting(name, descr, default, range, parser))
   def MultiStringSetting(name: String, arg: String, descr: String) = add(new MultiStringSetting(name, arg, descr))
-  def MultiChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], default: Option[() => Unit] = None)(
-      helper: MultiChoiceSetting => String = _ => choices.mkString(f"$descr:%n", f"%n  ", f"%n")
-  ) =
-    add(new MultiChoiceSetting(name, helpArg, descr, choices, default, helper))
+  def MultiChoiceSetting(name: String, helpArg: String, descr: String, choices: List[String], descriptions: List[String], default: Option[List[String]] = None) =
+    add(new MultiChoiceSetting(name, helpArg, descr, choices, descriptions, default))
   def OutputSetting(outputDirs: OutputDirs, default: String) = add(new OutputSetting(outputDirs, default))
   def PhasesSetting(name: String, descr: String, default: String = "") = add(new PhasesSetting(name, descr, default))
   def StringSetting(name: String, arg: String, descr: String, default: String) = add(new StringSetting(name, arg, descr, default))
@@ -553,57 +552,132 @@ class MutableSettings(val errorFn: String => Unit)
       }
   }
 
-  /** A setting that receives any combination of enumerated values,
-   *  including "_" to mean all values and "help" for verbose info.
-   *  In non-colonated mode, stops consuming args at the first
-   *  non-value, instead of at the next option, as for a multi-string.
+  /**
+   * A setting that receives multiple values. There are two modes
+   *   - choosing: the setting has a list of allowed chioces.
+   *     - These choices can be positive or negative, for exmample "-option:positive,-negative"
+   *     - If an option is both enabled positively and negatively, the positive wins
+   *     - The choice "_" enables all choices that have not explicitly been disabled
+   *
+   *   - !choosing: the setting accumulates all arguments.
+   *
+   * Arguments can be provided in colonated or non-colonated mode, i.e. "-option a b" or
+   * "-option:a,b". Note that arguments starting with a "-" can only be provided in colonated mode,
+   * otherwise they are interpreted as a new option.
+   *
+   * In colonated and choosing mode, the setting stops consuming arguments at the first non-choice,
+   * i.e. "-option a b c" only consumes "a" and "b" if "c" is not a valid choice.
+   *
+   * @param name         command-line setting name, eg "-Xlint"
+   * @param arg          description of the kind of arguments that need to be passed, eg "warning"
+   * @param descr        description of the setting
+   * @param choices      a list of allowed arguments. if empty, accepts any argument that doesn't start with "-"
+   * @param descriptions a description for each choice (for the help message), may be empty if no descriptions are necessary
+   * @param default      default arguments, if none are provided
    */
   class MultiChoiceSetting private[nsc](
     name: String,
     arg: String,
     descr: String,
     override val choices: List[String],
-    val default: Option[() => Unit],
-    helper: MultiChoiceSetting => String
+    val descriptions: List[String],
+    val default: Option[List[String]]
   ) extends MultiStringSetting(name, s"_,$arg,-$arg", s"$descr: `_' for all, `$name:help' to list") {
 
     private def badChoice(s: String, n: String) = errorFn(s"'$s' is not a valid choice for '$name'")
-    private def choosing = choices.nonEmpty
+    private def choosing = choices.nonEmpty // choices are known, error on invalid args
     private def isChoice(s: String) = (s == "_") || (choices contains (s stripPrefix "-"))
 
     private var sawHelp  = false
     private var sawAll   = false
-    private val adderAll = () => sawAll = true
-    private val noargs   = () => errorFn(s"'$name' requires an option. See '$name:help'.")
+
+    private def pos(s: String) = s stripPrefix "-"
+
+    /**
+     * This override takes care of including all possible choices in case the "_" argument was
+     * passed. It adds the choices that have not explicitly been enabled or disabled. This ensures
+     * that "this contains x" is consistent with "this.value contains x".
+     *
+     * The explicitly enabled / disabled options are stored in the underlying value [[v]], disabled
+     * ones are stored as "-arg".
+     *
+     * The fact that value and v are not the same leaks in some cases. For example, you should never
+     * use "value += arg", because that expands to "value = value + arg". In case sawAll is true,
+     * this would propagate all choices enabled by sawAll into the underlying v.
+     *
+     * Instead of "value += arg", you should use "this.add(arg)". I haven't found a good way to
+     * enforce that.
+     */
+    override def value: List[String] = {
+      if (!sawAll) v
+      else {
+        // add only those choices which have not explicitly been enabled or disabled.
+        val fromAll = choices.filterNot(c => v.exists(pos(_) == c))
+        v ++ fromAll
+      }
+    }
+
+    /**
+     * Add an argument to the list of values.
+     */
+    def add(arg: String) = {
+      if (choosing && !isChoice(arg)) badChoice(arg, name)
+      if (arg == "_") {
+        sawAll = true
+        value = v // the value_= setter has side effects, make sure to execute them.
+      } else {
+        val posArg = pos(arg)
+        if (arg == posArg) {
+          // positive overrides existing negative. so we filter existing (pos or neg), and add the arg
+          value = v.filterNot(pos(_) == posArg) :+ arg
+        } else {
+          // negative arg is only added if the arg doesn't exist yet (pos or neg)
+          if (!v.exists(pos(_) == posArg)) value = v :+ arg // not value += arg, see doc of the "value" getter
+        }
+      }
+    }
 
     override protected def tts(args: List[String], halting: Boolean) = {
       val added = collection.mutable.ListBuffer.empty[String]
+
       def tryArg(arg: String) = arg match {
-        case "_" if choosing               => addAll()
         case "help" if choosing            => sawHelp = true
-        case s if !choosing || isChoice(s) => added += s
+        case s if !choosing || isChoice(s) => added += s // this case also adds "_"
         case s                             => badChoice(s, name)
       }
+
+      // if "halting" is true, the args were not specified as , separated after a :
+      // but space separated after a space. we stop consuming args when seeing
+      //   - an arg starting with a "-", that is a new option
+      //   - if the choices are known (choosing), on the first non-choice
       def stoppingAt(arg: String) = (arg startsWith "-") || (choosing && !isChoice(arg))
+
       def loop(args: List[String]): List[String] = args match {
         case arg :: _ if halting && stoppingAt(arg) => args
         case arg :: rest                            => tryArg(arg) ; loop(rest)
         case Nil                                    => Nil
       }
+
       val rest = loop(args)
-      if (rest.size == args.size)
-        (default getOrElse noargs)()   // if no arg consumed, trigger default action or error
-      else
-        value ++= added.toList         // update all new settings at once
+      if (rest.size == args.size) default match { // if no arg consumed, use defaults or error
+        case Some(defaults) => defaults foreach add
+        case None => errorFn(s"'$name' requires an option. See '$name:help'.")
+      } else {
+        added.toList foreach add
+      }
+
       Some(rest)
     }
 
     def isHelping: Boolean = sawHelp
-    def help: String       = helper(this)
-    def addAll(): Unit     = (default getOrElse adderAll)()
 
-    // the semantics is: s is enabled, i.e., either s or (_ but not -s)
-    override def contains(s: String) = isChoice(s) && (value contains s) || (sawAll && !(value contains s"-$s"))
+    def help: String = {
+      val choiceLength = choices.map(_.length).max + 1
+      val formatStr = s"  %-${choiceLength}s %s"
+      choices.zipAll(descriptions, "", "").map {
+        case (arg, descr) => formatStr.format(arg, descr)
+      } mkString (f"$descr%n", f"%n", "")
+    }
   }
 
   /** A setting that accumulates all strings supplied to it,
diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
index 8e69598614..1609aa5ff7 100644
--- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
@@ -84,13 +84,9 @@ trait ScalaSettings extends AbsScalaSettings
       name    = "-language",
       helpArg = "feature",
       descr   = description,
-      choices = features map (_._1)
-    ) { s =>
-      val helpline: ((String, String)) => String = {
-        case (name, text) => f"  $name%-25s $text%n"
-      }
-      features map helpline mkString (f"$description:%n", "", f"%n")
-    }
+      choices = features map (_._1),
+      descriptions = features map (_._2)
+    )
   }
 
   /*
@@ -193,7 +189,6 @@ trait ScalaSettings extends AbsScalaSettings
   val Ygenjavap       = StringSetting     ("-Ygen-javap", "dir", "Generate a parallel output directory of .javap files.", "")
   val Ygenasmp        = StringSetting     ("-Ygen-asmp",  "dir", "Generate a parallel output directory of .asmp files (ie ASM Textifier output).", "")
   val Ydumpclasses    = StringSetting     ("-Ydump-classes", "dir", "Dump the generated bytecode to .class files (useful for reflective compilation that utilizes in-memory classloaders).", "")
-  val Ystatistics     = BooleanSetting    ("-Ystatistics", "Print compiler statistics.") andThen (scala.reflect.internal.util.Statistics.enabled = _)
   val stopAfter       = PhasesSetting     ("-Ystop-after", "Stop after") withAbbreviation ("-stop") // backward compat
   val stopBefore      = PhasesSetting     ("-Ystop-before", "Stop before")
   val Yrangepos       = BooleanSetting    ("-Yrangepos", "Use range positions for syntax trees.")
@@ -217,6 +212,20 @@ trait ScalaSettings extends AbsScalaSettings
 
   private def removalIn212 = "This flag is scheduled for removal in 2.12. If you have a case where you need this flag then please report a bug."
 
+  val YstatisticsPhases = {
+    val phases = List("parser", "typer", "patmat", "erasure", "cleanup")
+    val description = "Print compiler statistics for specific phases"
+    MultiChoiceSetting(
+      name = "-Ystatistics",
+      helpArg = "phase",
+      descr = description,
+      choices = phases,
+      descriptions = Nil,
+      default = Some(List("_"))) withPostSetHook { _ => scala.reflect.internal.util.Statistics.enabled = true }
+  }
+
+  def YstatisticsEnabled = YstatisticsPhases.value.nonEmpty
+
   /** Area-specific debug output.
    */
   val Ydocdebug               = BooleanSetting("-Ydoc-debug", "Trace all scaladoc activity.")
diff --git a/src/compiler/scala/tools/nsc/settings/Warnings.scala b/src/compiler/scala/tools/nsc/settings/Warnings.scala
index 4c37633301..771543ec77 100644
--- a/src/compiler/scala/tools/nsc/settings/Warnings.scala
+++ b/src/compiler/scala/tools/nsc/settings/Warnings.scala
@@ -17,145 +17,93 @@ trait Warnings {
   // Warning semantics.
   val fatalWarnings = BooleanSetting("-Xfatal-warnings", "Fail the compilation if there are any warnings.")
 
-  // These additional warnings are all so noisy as to be useless in their
-  // present form, but have the potential to offer useful info.
-  protected def allWarnings = lintWarnings ++ List(
-    warnDeadCode,
-    warnValueDiscard,
-    warnNumericWiden,
-    warnUnused,           // SI-7712, SI-7707 warnUnused not quite ready for prime-time
-    warnUnusedImport,     // currently considered too noisy for general use
-    warnValueOverrides    // currently turned off as experimental
-  )
-  // These warnings should be pretty quiet unless you're doing
-  // something inadvisable.
-  protected def lintWarnings = List(
-    warnInaccessible,
-    warnNullaryOverride,
-    warnNullaryUnit,
-    warnAdaptedArgs,
-    warnInferAny,
-    warnMissingInterpolator,
-    warnDocDetached,
-    warnPrivateShadow,
-    warnTypeParameterShadow,
-    warnPolyImplicitOverload,
-    warnOptionImplicit,
-    warnDelayedInit,
-    warnByNameRightAssociative,
-    warnPackageObjectClasses,
-    warnUnsoundMatch
-  )
-
-  // Individual warnings. They can be set with -Ywarn.
-  private def nonlintflag(name: String, text: String): BooleanSetting = BooleanSetting(name, text)
-
-  val warnDeadCode         = nonlintflag("-Ywarn-dead-code",
-                             "Warn when dead code is identified.")
-  val warnValueDiscard     = nonlintflag("-Ywarn-value-discard",
-                             "Warn when non-Unit expression results are unused.")
-  val warnNumericWiden     = nonlintflag("-Ywarn-numeric-widen",
-                             "Warn when numerics are widened.")
-  val warnUnused           = nonlintflag("-Ywarn-unused",
-                             "Warn when local and private vals, vars, defs, and types are are unused")
-  val warnUnusedImport     = nonlintflag("-Ywarn-unused-import",
-                             "Warn when imports are unused")
-
-  // Lint warnings that have no -Y avatar, created with new instead of the autoregistering factory method.
-  // They evaluate true if set to true or else are unset but -Xlint is true
-  private def lintflag(name: String, text: String): BooleanSetting =
-    new BooleanSetting(name, text) {
-      override def value = if (isSetByUser) super.value else xlint
-    }
+  // Non-lint warnings
 
-  val warnAdaptedArgs          = lintflag("adapted-args",
-                                 "Warn if an argument list is modified to match the receiver.")
-  val warnNullaryUnit          = lintflag("nullary-unit",
-                                 "Warn when nullary methods return Unit.")
-  val warnInaccessible         = lintflag("inaccessible",
-                                "Warn about inaccessible types in method signatures.")
-  val warnNullaryOverride      = lintflag("nullary-override",
-                                "Warn when non-nullary `def f()' overrides nullary `def f'.")
-  val warnInferAny             = lintflag("infer-any",
-                                "Warn when a type argument is inferred to be `Any`.")
-  val warnMissingInterpolator  = lintflag("missing-interpolator",
-                                "A string literal appears to be missing an interpolator id.")
-  val warnDocDetached          = lintflag("doc-detached",
-                                "A ScalaDoc comment appears to be detached from its element.")
-  val warnPrivateShadow        = lintflag("private-shadow",
-                                "A private field (or class parameter) shadows a superclass field.")
-  val warnTypeParameterShadow  = lintflag("type-parameter-shadow",
-                                "A local type parameter shadows a type already in scope.")
-  val warnPolyImplicitOverload = lintflag("poly-implicit-overload",
-                                "Parameterized overloaded implicit methods are not visible as view bounds")
-  val warnOptionImplicit       = lintflag("option-implicit",
-                                "Option.apply used implicit view.")
-  val warnDelayedInit          = lintflag("delayedinit-select",
-                                "Selecting member of DelayedInit")
-  val warnByNameRightAssociative = lintflag("by-name-right-associative",
-                                "By-name parameter of right associative operator")
-  val warnPackageObjectClasses = lintflag("package-object-classes",
-                                "Class or object defined in package object")
-  val warnUnsoundMatch         = lintflag("unsound-match",
-                                "Pattern match may not be typesafe")
+  val warnDeadCode         = BooleanSetting("-Ywarn-dead-code", "Warn when dead code is identified.")
+  val warnValueDiscard     = BooleanSetting("-Ywarn-value-discard", "Warn when non-Unit expression results are unused.")
+  val warnNumericWiden     = BooleanSetting("-Ywarn-numeric-widen", "Warn when numerics are widened.")
+  // SI-7712, SI-7707 warnUnused not quite ready for prime-time
+  val warnUnused           = BooleanSetting("-Ywarn-unused", "Warn when local and private vals, vars, defs, and types are are unused.")
+  // currently considered too noisy for general use
+  val warnUnusedImport     = BooleanSetting("-Ywarn-unused-import", "Warn when imports are unused.")
 
   // Experimental lint warnings that are turned off, but which could be turned on programmatically.
   // These warnings are said to blind those who dare enable them.
   // They are not activated by -Xlint and can't be enabled on the command line.
-  val warnValueOverrides = {
-    val flag = lintflag("value-overrides", "Generated value class method overrides an implementation")
+  val warnValueOverrides = { // currently turned off as experimental. creaded using constructor (new BS), so not available on the command line.
+  val flag = new BooleanSetting("value-overrides", "Generated value class method overrides an implementation")
     flag.value = false
     flag
   }
 
-  // The Xlint warning group.
-  private val xlint = new BooleanSetting("-Zunused", "True if -Xlint or -Xlint:_")
-  // On -Xlint or -Xlint:_, set xlint, otherwise set the lint warning unless already set true
-  val lint = {
-    val description = "Enable or disable specific warnings"
-    val choices     = (lintWarnings map (_.name)).sorted
-    MultiChoiceSetting(
-      name    = "-Xlint",
-      helpArg = "warning",
-      descr   = description,
-      choices = choices,
-      default = Some(() => xlint.value = true)
-    ) { s =>
-      def helpline(n: String) = lintWarnings.find(_.name == n).map(w => f"  ${w.name}%-25s ${w.helpDescription}%n")
-      choices flatMap (helpline(_)) mkString (f"$description:%n", "", f"%n")
-    } withPostSetHook { x =>
-      val Neg = "-"
-      def setPolitely(b: BooleanSetting, v: Boolean) = if (!b.isSetByUser || !b) b.value = v
-      def set(w: String, v: Boolean) = lintWarnings find (_.name == w) foreach (setPolitely(_, v))
-      def propagate(ss: List[String]): Unit = ss match {
-        case w :: rest => if (w startsWith Neg) set(w stripPrefix Neg, false) else set(w, true) ; propagate(rest)
-        case Nil       => ()
-      }
-      propagate(x.value)
-    }
-  }
+  // Lint warnings
+
+  def warnAdaptedArgs            = lint contains "adapted-args"
+  def warnNullaryUnit            = lint contains "nullary-unit"
+  def warnInaccessible           = lint contains "inaccessible"
+  def warnNullaryOverride        = lint contains "nullary-override"
+  def warnInferAny               = lint contains "infer-any"
+  def warnMissingInterpolator    = lint contains "missing-interpolator"
+  def warnDocDetached            = lint contains "doc-detached"
+  def warnPrivateShadow          = lint contains "private-shadow"
+  def warnTypeParameterShadow    = lint contains "type-parameter-shadow"
+  def warnPolyImplicitOverload   = lint contains "poly-implicit-overload"
+  def warnOptionImplicit         = lint contains "option-implicit"
+  def warnDelayedInit            = lint contains "delayedinit-select"
+  def warnByNameRightAssociative = lint contains "by-name-right-associative"
+  def warnPackageObjectClasses   = lint contains "package-object-classes"
+  def warnUnsoundMatch           = lint contains "unsound-match"
 
   // Lint warnings that are currently -Y, but deprecated in that usage
   @deprecated("Use warnAdaptedArgs", since="2.11.2")
-  val YwarnAdaptedArgs      = BooleanSetting("-Ywarn-adapted-args",
-                             "Warn if an argument list is modified to match the receiver.") enabling List(warnAdaptedArgs)
-                             //withDeprecationMessage "Enable -Xlint:adapted-args"
+  def YwarnAdaptedArgs = warnAdaptedArgs
   @deprecated("Use warnNullaryUnit", since="2.11.2")
-  val YwarnNullaryUnit      = BooleanSetting("-Ywarn-nullary-unit",
-                             "Warn when nullary methods return Unit.") enabling List(warnNullaryUnit)
-                             //withDeprecationMessage "Enable -Xlint:nullary-unit"
+  def YwarnNullaryUnit = warnNullaryUnit
   @deprecated("Use warnInaccessible", since="2.11.2")
-  val YwarnInaccessible     = BooleanSetting("-Ywarn-inaccessible",
-                             "Warn about inaccessible types in method signatures.") enabling List(warnInaccessible)
-                             //withDeprecationMessage "Enable -Xlint:inaccessible"
+  def YwarnInaccessible = warnInaccessible
   @deprecated("Use warnNullaryOverride", since="2.11.2")
-  val YwarnNullaryOverride  = BooleanSetting("-Ywarn-nullary-override",
-                             "Warn when non-nullary `def f()' overrides nullary `def f'.") enabling List(warnNullaryOverride)
-                             //withDeprecationMessage "Enable -Xlint:nullary-override"
+  def YwarnNullaryOverride = warnNullaryOverride
   @deprecated("Use warnInferAny", since="2.11.2")
-  val YwarnInferAny         = BooleanSetting("-Ywarn-infer-any",
-                             "Warn when a type argument is inferred to be `Any`.") enabling List(warnInferAny)
-                             //withDeprecationMessage "Enable -Xlint:infer-any"
+  def YwarnInferAny = warnInferAny
+
+  // The Xlint warning group.
+  val lint: MultiChoiceSetting = {
+    val description = "Enable or disable specific warnings"
+
+    val choices = List(
+      ("adapted-args",              "Warn if an argument list is modified to match the receiver.",               true),
+      ("nullary-unit",              "Warn when nullary methods return Unit.",                                    true),
+      ("inaccessible",              "Warn about inaccessible types in method signatures.",                       true),
+      ("nullary-override",          "Warn when non-nullary `def f()' overrides nullary `def f'.",                true),
+      ("infer-any",                 "Warn when a type argument is inferred to be `Any`.",                        true),
+      ("missing-interpolator",      "A string literal appears to be missing an interpolator id.",                false),
+      ("doc-detached",              "A ScalaDoc comment appears to be detached from its element.",               false),
+      ("private-shadow",            "A private field (or class parameter) shadows a superclass field.",          false),
+      ("type-parameter-shadow",     "A local type parameter shadows a type already in scope.",                   false),
+      ("poly-implicit-overload",    "Parameterized overloaded implicit methods are not visible as view bounds.", false),
+      ("option-implicit",           "Option.apply used implicit view.",                                          false),
+      ("delayedinit-select",        "Selecting member of DelayedInit",                                           false),
+      ("by-name-right-associative", "By-name parameter of right associative operator.",                          false),
+      ("package-object-classes",    "Class or object defined in package object.",                                false),
+      ("unsound-match",             "Pattern match may not be typesafe.",                                        false)
+    ).sorted
+
+    for (c <- choices.filter(_._3)) {
+      BooleanSetting("-Ywarn-"+ c._1, c._2) withPostSetHook { s =>
+        if (s) lint.add(c._1)
+        else lint.add("-" + c._1)
+      } // withDeprecationMessage s"Enable -Xlint:${c._1}"
+    }
+
+    MultiChoiceSetting(
+      name         = "-Xlint",
+      helpArg      = "warning",
+      descr        = description,
+      choices      = choices map (_._1),
+      descriptions = choices map (_._2),
+      default      = Some(List("_"))
+    )
+  }
 
   private lazy val warnSelectNullable = BooleanSetting("-Xcheck-null", "This option is obsolete and does nothing.")
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index fb7651ffd6..421021163e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -552,7 +552,7 @@ trait Infer extends Checkable {
         }
         case _ => context.tree.pos
       }
-      if (settings.warnInferAny.value && context.reportErrors && canWarnAboutAny) {
+      if (settings.warnInferAny && context.reportErrors && canWarnAboutAny) {
         foreachWithIndex(targs) ((targ, idx) =>
           targ.typeSymbol match {
             case sym @ (AnyClass | AnyValClass) =>
diff --git a/src/compiler/scala/tools/nsc/util/StatisticsInfo.scala b/src/compiler/scala/tools/nsc/util/StatisticsInfo.scala
index 225f6ca68e..a5d579dc37 100644
--- a/src/compiler/scala/tools/nsc/util/StatisticsInfo.scala
+++ b/src/compiler/scala/tools/nsc/util/StatisticsInfo.scala
@@ -14,12 +14,10 @@ abstract class StatisticsInfo {
   import global._
   import scala.reflect.internal.TreesStats.nodeByType
 
-  val phasesShown = List("parser", "typer", "patmat", "erasure", "cleanup")
-
   val retainedCount  = Statistics.newCounter("#retained tree nodes")
   val retainedByType = Statistics.newByClass("#retained tree nodes by type")(Statistics.newCounter(""))
 
-  def print(phase: Phase) = if (phasesShown contains phase.name) {
+  def print(phase: Phase) = if (settings.YstatisticsPhases contains phase.name) {
     inform("*** Cumulative statistics at phase " + phase)
     retainedCount.value = 0
     for (c <- retainedByType.keys)