Remove -Y settings that are no longer used in 2.12

Added a deprecation warning for `-optimize`.

Later we'll also graduate `-Yopt` to `-opt`, probably for 2.12.0-M5.

10 files changed, 36 insertions, 98 deletions

diff --git a/src/compiler/scala/tools/nsc/Reporting.scala b/src/compiler/scala/tools/nsc/Reporting.scala
index e11cba466e..5bdbf4bb6a 100644
--- a/src/compiler/scala/tools/nsc/Reporting.scala
+++ b/src/compiler/scala/tools/nsc/Reporting.scala
@@ -26,27 +26,30 @@ trait Reporting extends scala.reflect.internal.Reporting { self: ast.Positions w
   protected def PerRunReporting = new PerRunReporting
   class PerRunReporting extends PerRunReportingBase {
     /** Collects for certain classes of warnings during this run. */
-    private class ConditionalWarning(what: String, option: Settings#BooleanSetting)(reRunFlag: String = option.name) {
+    private class ConditionalWarning(what: String, doReport: () => Boolean, setting: Settings#Setting) {
+      def this(what: String, booleanSetting: Settings#BooleanSetting) {
+        this(what, () => booleanSetting, booleanSetting)
+      }
       val warnings = mutable.LinkedHashMap[Position, String]()
       def warn(pos: Position, msg: String) =
-        if (option) reporter.warning(pos, msg)
+        if (doReport()) reporter.warning(pos, msg)
         else if (!(warnings contains pos)) warnings += ((pos, msg))
       def summarize() =
-        if (warnings.nonEmpty && (option.isDefault || option)) {
+        if (warnings.nonEmpty && (setting.isDefault || doReport())) {
           val numWarnings  = warnings.size
           val warningVerb  = if (numWarnings == 1) "was" else "were"
           val warningCount = countElementsAsString(numWarnings, s"$what warning")
 
-          reporter.warning(NoPosition, s"there $warningVerb $warningCount; re-run with $reRunFlag for details")
+          reporter.warning(NoPosition, s"there $warningVerb $warningCount; re-run with ${setting.name} for details")
         }
     }
 
     // This change broke sbt; I gave it the thrilling name of uncheckedWarnings0 so
     // as to recover uncheckedWarnings for its ever-fragile compiler interface.
-    private val _deprecationWarnings    = new ConditionalWarning("deprecation", settings.deprecation)()
-    private val _uncheckedWarnings      = new ConditionalWarning("unchecked", settings.unchecked)()
-    private val _featureWarnings        = new ConditionalWarning("feature", settings.feature)()
-    private val _inlinerWarnings        = new ConditionalWarning("inliner", settings.YinlinerWarnings)(if (settings.isBCodeActive) settings.YoptWarnings.name else settings.YinlinerWarnings.name)
+    private val _deprecationWarnings    = new ConditionalWarning("deprecation", settings.deprecation)
+    private val _uncheckedWarnings      = new ConditionalWarning("unchecked", settings.unchecked)
+    private val _featureWarnings        = new ConditionalWarning("feature", settings.feature)
+    private val _inlinerWarnings        = new ConditionalWarning("inliner", () => !settings.YoptWarningsSummaryOnly, settings.YoptWarnings)
     private val _allConditionalWarnings = List(_deprecationWarnings, _uncheckedWarnings, _featureWarnings, _inlinerWarnings)
 
     // TODO: remove in favor of the overload that takes a Symbol, give that argument a default (NoSymbol)
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index 831a0412cd..d4715471f6 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -2811,11 +2811,6 @@ self =>
             if (mods.isTrait) (Modifiers(Flags.TRAIT), List())
             else (accessModifierOpt(), paramClauses(name, classContextBounds, ofCaseClass = mods.isCase))
           var mods1 = mods
-          if (mods.isTrait) {
-            if (settings.YvirtClasses && in.token == SUBTYPE) mods1 |= Flags.DEFERRED
-          } else if (in.token == SUBTYPE) {
-            syntaxError("classes are not allowed to be virtual", skipIt = false)
-          }
           val template = templateOpt(mods1, name, constrMods withAnnotations constrAnnots, vparamss, tstart)
           val result = gen.mkClassDef(mods1, name, tparams, template)
           // Context bounds generate implicit parameters (part of the template) with types
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index f423f3c7fe..2698225a06 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -60,10 +60,7 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
   def isAnonymousOrLocalClass(classSym: Symbol): Boolean = {
     assert(classSym.isClass, s"not a class: $classSym")
     val r = exitingPickler(classSym.isAnonymousClass) || !classSym.originalOwner.isClass
-    if (r && settings.Ybackend.value == "GenBCode") {
-      // this assertion only holds in GenBCode. lambda lift renames symbols and may accidentally
-      // introduce `$lambda` into a class name, making `isDelambdafyFunction` true. under GenBCode
-      // we prevent this, see `nonAnon` in LambdaLift.
+    if (r) {
       // phase travel necessary: after flatten, the name includes the name of outer classes.
       // if some outer name contains $lambda, a non-lambda class is considered lambda.
       assert(exitingPickler(!classSym.isDelambdafyFunction), classSym.name)
diff --git a/src/compiler/scala/tools/nsc/settings/FscSettings.scala b/src/compiler/scala/tools/nsc/settings/FscSettings.scala
index fffbb4333f..d6013e0b00 100644
--- a/src/compiler/scala/tools/nsc/settings/FscSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/FscSettings.scala
@@ -37,9 +37,7 @@ class FscSettings(error: String => Unit) extends Settings(error) {
   /** If a setting (other than a PathSetting) represents a path or paths.
    *  For use in absolutization.
    */
-  private def holdsPath = Set[Settings#Setting](
-    d, dependencyfile, pluginsDir, Ygenjavap
-  )
+  private def holdsPath = Set[Settings#Setting](d, dependencyfile, pluginsDir)
 
   override def processArguments(arguments: List[String], processAll: Boolean): (Boolean, List[String]) = {
     val (r, args) = super.processArguments(arguments, processAll)
diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
index 1446d22217..c524121646 100644
--- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
@@ -34,9 +34,6 @@ trait ScalaSettings extends AbsScalaSettings
   /** Enabled under -Xfuture. */
   protected def futureSettings = List[BooleanSetting]()
 
-  /** Enabled under -optimise. */
-  def optimiseSettings = List[BooleanSetting](inline, inlineHandlers, Xcloselim, Xdce, YconstOptimization)
-
   /** 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)
 
@@ -167,18 +164,10 @@ trait ScalaSettings extends AbsScalaSettings
   val browse          = PhasesSetting     ("-Ybrowse", "Browse the abstract syntax tree after")
   val check           = PhasesSetting     ("-Ycheck", "Check the tree at the end of")
   val Yshow           = PhasesSetting     ("-Yshow", "(Requires -Xshow-class or -Xshow-object) Show after")
-  val Xcloselim       = BooleanSetting    ("-Yclosure-elim", "Perform closure elimination.")
-  val YconstOptimization  = BooleanSetting    ("-Yconst-opt", "Perform optimization with constant values.")
   val Ycompacttrees   = BooleanSetting    ("-Ycompact-trees", "Use compact tree printer when displaying trees.")
   val noCompletion    = BooleanSetting    ("-Yno-completion", "Disable tab-completion in the REPL.")
-  val Xdce            = BooleanSetting    ("-Ydead-code", "Perform dead code elimination.")
   val debug           = BooleanSetting    ("-Ydebug", "Increase the quantity of debugging output.")
-  //val doc           = BooleanSetting    ("-Ydoc", "Generate documentation")
   val termConflict    = ChoiceSetting     ("-Yresolve-term-conflict", "strategy", "Resolve term conflicts", List("package", "object", "error"), "error")
-  val inline          = BooleanSetting    ("-Yinline", "Perform inlining when possible.")
-  val inlineHandlers  = BooleanSetting    ("-Yinline-handlers", "Perform exception handler inlining when possible.")
-  val YinlinerWarnings= BooleanSetting    ("-Yinline-warnings", "Emit inlining warnings. (Normally suppressed due to high volume)")
-  val Xlinearizer     = ChoiceSetting     ("-Ylinearizer", "which", "Linearizer to use", List("normal", "dfs", "rpo", "dump"), "rpo")
   val log             = PhasesSetting     ("-Ylog", "Log operations during")
   val Ylogcp          = BooleanSetting    ("-Ylog-classpath", "Output information about what classpath is being applied.")
   val Ynogenericsig   = BooleanSetting    ("-Yno-generic-signatures", "Suppress generation of generic signatures for Java.")
@@ -195,7 +184,6 @@ trait ScalaSettings extends AbsScalaSettings
   val Yshowsymkinds   = BooleanSetting    ("-Yshow-symkinds", "Print abbreviated symbol kinds next to symbol names.")
   val Yshowsymowners  = BooleanSetting    ("-Yshow-symowners", "Print owner identifiers next to symbol names.")
   val skip            = PhasesSetting     ("-Yskip", "Skip")
-  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 stopAfter       = PhasesSetting     ("-Ystop-after", "Stop after") withAbbreviation ("-stop") // backward compat
@@ -214,10 +202,6 @@ trait ScalaSettings extends AbsScalaSettings
   val YclasspathImpl  = ChoiceSetting     ("-YclasspathImpl", "implementation", "Choose classpath scanning method.", List(ClassPathRepresentationType.Recursive, ClassPathRepresentationType.Flat), ClassPathRepresentationType.Recursive)
   val YdisableFlatCpCaching  = BooleanSetting    ("-YdisableFlatCpCaching", "Do not cache flat classpath representation of classpath elements from jars across compiler instances.")
 
-  val YvirtClasses    = false // too embryonic to even expose as a -Y //BooleanSetting    ("-Yvirtual-classes", "Support virtual classes")
-  val YdisableUnreachablePrevention = BooleanSetting("-Ydisable-unreachable-prevention", "Disable the prevention of unreachable blocks in code generation.")
-  val YnoLoadImplClass = BooleanSetting   ("-Yno-load-impl-class", "Do not load $class.class files.")
-
   val exposeEmptyPackage = BooleanSetting ("-Yexpose-empty-package", "Internal only: expose the empty package.").internalOnly()
   val Ydelambdafy        = ChoiceSetting  ("-Ydelambdafy", "strategy", "Strategy used for translating lambdas into JVM code.", List("inline", "method"), "method")
 
@@ -304,10 +288,9 @@ trait ScalaSettings extends AbsScalaSettings
     helpArg = "warning",
     descr = "Enable optimizer warnings",
     domain = YoptWarningsChoices,
-    default = Some(List(YoptWarningsChoices.atInlineFailed.name))) withPostSetHook (self => {
-    if (self.value subsetOf Set(YoptWarningsChoices.none, YoptWarningsChoices.atInlineFailedSummary)) YinlinerWarnings.value = false
-    else YinlinerWarnings.value = true
-  })
+    default = Some(List(YoptWarningsChoices.atInlineFailed.name)))
+
+  def YoptWarningsSummaryOnly = YoptWarnings.value subsetOf Set(YoptWarningsChoices.none, YoptWarningsChoices.atInlineFailedSummary)
 
   def YoptWarningEmitAtInlineFailed =
     !YoptWarnings.isSetByUser ||
@@ -352,22 +335,15 @@ trait ScalaSettings extends AbsScalaSettings
     str => Some(if(str.equalsIgnoreCase("off")) Int.MaxValue else str.toInt))
   val Yquasiquotedebug        = BooleanSetting("-Yquasiquote-debug", "Trace quasiquote-related activities.")
 
-  // TODO 2.12 Remove
-  val Yinferdebug             = BooleanSetting("-Yinfer-debug", "Trace type inference and implicit search.") withDeprecationMessage("Use -Ytyper-debug") enabling(List(Ytyperdebug))
-
   /** Groups of Settings.
    */
   val future        = BooleanSetting("-Xfuture", "Turn on future language features.") enablingIfNotSetByUser futureSettings
-  val optimise      = BooleanSetting("-optimise", "Generates faster bytecode by applying optimisations to the program") withAbbreviation "-optimize" enablingIfNotSetByUser optimiseSettings
-  val nooptimise    = BooleanSetting("-Ynooptimise", "Clears all the flags set by -optimise. Useful for testing optimizations in isolation.") withAbbreviation "-Ynooptimize" disabling optimise::optimiseSettings
+  val optimise      = BooleanSetting("-optimise", "Compiler flag for the optimizer in Scala 2.11")
+    .withAbbreviation("-optimize")
+    .withDeprecationMessage("In 2.12, -optimise enables -Yopt:l:classpath. Check -Yopt:help for using the Scala 2.12 optimizer.")
+    .withPostSetHook(_ => Yopt.tryToSet(List(YoptChoices.lClasspath.name)))
   val Xexperimental = BooleanSetting("-Xexperimental", "Enable experimental extensions.") enablingIfNotSetByUser experimentalSettings
 
-  /**
-   * Settings motivated by GenBCode
-   */
-  val Ybackend = ChoiceSetting ("-Ybackend", "choice of bytecode emitter", "Choice of bytecode emitter.",
-                                List("GenBCode"),
-                                "GenBCode")
   // Feature extensions
   val XmacroSettings          = MultiStringSetting("-Xmacro-settings", "option", "Custom settings for macros.")
 
@@ -391,8 +367,6 @@ trait ScalaSettings extends AbsScalaSettings
   /** Test whether this is scaladoc we're looking at */
   def isScaladoc = false
 
-  def isBCodeActive = Ybackend.value == "GenBCode"
-
   object MacroExpand {
     val None = "none"
     val Normal = "normal"
@@ -400,20 +374,18 @@ trait ScalaSettings extends AbsScalaSettings
   }
 
   def conflictWarning: Option[String] = {
-    def oldOptimiseFlagsInGenBCode: Option[String] = {
-      val optFlags: List[Setting] = if (optimise.value) List(optimise) else optimiseSettings.filter(_.value)
-      if (isBCodeActive && optFlags.nonEmpty) {
-        val msg = s"""Compiler settings for the 2.11 optimizer (${optFlags.map(_.name).mkString(", ")}) are incompatible with -Ybackend:GenBCode (which is the default in 2.12).
-                     |The optimizer settings are ignored. See -Yopt:help for enabling the new optimizer in 2.12.""".stripMargin
-        Some(msg)
-      } else
-        None
-    }
+    // See cd878232b5 for an example how to warn about conflicting settings
 
-    List(oldOptimiseFlagsInGenBCode /*, moreToCome */).flatten match {
+    /*
+    def checkSomeConflict: Option[String] = ...
+
+    List(/* checkSomeConflict, ... */).flatten match {
       case Nil => None
       case warnings => Some("Conflicting compiler settings were detected. Some settings will be ignored.\n" + warnings.mkString("\n"))
     }
+    */
+
+    None
   }
 }
 
diff --git a/src/compiler/scala/tools/nsc/transform/CleanUp.scala b/src/compiler/scala/tools/nsc/transform/CleanUp.scala
index 112dedce81..0fb6213d36 100644
--- a/src/compiler/scala/tools/nsc/transform/CleanUp.scala
+++ b/src/compiler/scala/tools/nsc/transform/CleanUp.scala
@@ -21,16 +21,8 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL {
   val phaseName: String = "cleanup"
 
   /* used in GenBCode: collects ClassDef symbols owning a main(Array[String]) method */
-  private var entryPoints: List[Symbol] = null
-  def getEntryPoints: List[Symbol] = {
-    assert(settings.isBCodeActive, "Candidate Java entry points are collected here only when GenBCode in use.")
-    entryPoints sortBy ("" + _.fullName) // For predictably ordered error messages.
-  }
-
-  override def newPhase(prev: scala.tools.nsc.Phase): StdPhase = {
-    entryPoints = if (settings.isBCodeActive) Nil else null;
-    super.newPhase(prev)
-  }
+  private var entryPoints: List[Symbol] = Nil
+  def getEntryPoints: List[Symbol] = entryPoints sortBy ("" + _.fullName) // For predictably ordered error messages.
 
   protected def newTransformer(unit: CompilationUnit): Transformer =
     new CleanUpTransformer(unit)
@@ -378,11 +370,7 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL {
     }
 
     override def transform(tree: Tree): Tree = tree match {
-
-      case _: ClassDef
-      if (entryPoints != null) &&
-         genBCode.isJavaEntryPoint(tree.symbol, currentUnit)
-      =>
+      case _: ClassDef if genBCode.isJavaEntryPoint(tree.symbol, currentUnit) =>
         // collecting symbols for entry points here (as opposed to GenBCode where they are used)
         // has the advantage of saving an additional pass over all ClassDefs.
         entryPoints ::= tree.symbol
diff --git a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
index f15d05f7df..9825efdc67 100644
--- a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
+++ b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
@@ -570,8 +570,6 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre
   // The functional interface that can be used to adapt the lambda target method `target` to the
   // given function type. Returns `NoSymbol` if the compiler settings are unsuitable.
   private def java8CompatFunctionalInterface(target: Symbol, functionType: Type): (Symbol, Boolean) = {
-    val canUseLambdaMetafactory = settings.isBCodeActive
-
     val sym = functionType.typeSymbol
     val pack = currentRun.runDefinitions.Scala_Java8_CompatPackage
     val name1 = specializeTypes.specializedFunctionName(sym, functionType.typeArgs)
@@ -583,6 +581,6 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre
     } else {
       pack.info.decl(name1.toTypeName.prepend("J"))
     }
-    (if (canUseLambdaMetafactory) functionalInterface else NoSymbol, isSpecialized)
+    (functionalInterface, isSpecialized)
   }
 }
diff --git a/src/compiler/scala/tools/nsc/transform/LambdaLift.scala b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala
index f6e2dd68f0..a372136781 100644
--- a/src/compiler/scala/tools/nsc/transform/LambdaLift.scala
+++ b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala
@@ -246,9 +246,8 @@ abstract class LambdaLift extends InfoTransform {
       }
 
       // make sure that the name doesn't make the symbol accidentally `isAnonymousClass` (et.al) by
-      // introducing `$anon` in its name. to be cautious, we don't make this change in the default
-      // backend under 2.11.x, so only in GenBCode.
-      def nonAnon(s: String) = if (settings.Ybackend.value == "GenBCode") nme.ensureNonAnon(s) else s
+      // introducing `$anon` in its name.
+      def nonAnon(s: String) = nme.ensureNonAnon(s)
 
       def newName(sym: Symbol): Name = {
         val originalName = sym.name
diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
index 7cd05b56c3..eea1f53cbc 100644
--- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala
+++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
@@ -236,10 +236,7 @@ abstract class UnCurry extends InfoTransform
             !(specialized =:= fun.tpe)
           }
 
-          def canUseDelamdafyMethod = (
-               (inConstructorFlag == 0) // Avoiding synthesizing code prone to SI-6666, SI-8363 by using old-style lambda translation
-            && (!isSpecialized || settings.isBCodeActive) // DelambdafyTransformer currently only emits generic FunctionN-s, use the old style in the meantime
-          )
+          def canUseDelamdafyMethod = inConstructorFlag == 0 // Avoiding synthesizing code prone to SI-6666, SI-8363 by using old-style lambda translation
           if (inlineFunctionExpansion || !canUseDelamdafyMethod) {
             val parents = addSerializable(abstractFunctionForFunctionType(fun.tpe))
             val anonClass = fun.symbol.owner newAnonymousFunctionClass(fun.pos, inConstructorFlag) addAnnotation SerialVersionUIDAnnotation
diff --git a/src/compiler/scala/tools/util/PathResolver.scala b/src/compiler/scala/tools/util/PathResolver.scala
index 42b939f18b..1c9167b2ea 100644
--- a/src/compiler/scala/tools/util/PathResolver.scala
+++ b/src/compiler/scala/tools/util/PathResolver.scala
@@ -167,12 +167,6 @@ object PathResolver {
       |}""".asLines
   }
 
-  // used in PathResolver constructor
-  private object NoImplClassJavaContext extends JavaContext {
-    override def isValidName(name: String): Boolean =
-      !ReflectionUtils.scalacShouldntLoadClassfile(name)
-  }
-
   @deprecated("This method is no longer used be scalap and will be deleted", "2.11.5")
   def fromPathString(path: String, context: JavaContext = DefaultJavaContext): JavaClassPath = {
     val s = new Settings()
@@ -313,10 +307,7 @@ abstract class PathResolverBase[BaseClassPathType <: ClassFileLookup[AbstractFil
 class PathResolver(settings: Settings, context: JavaContext)
   extends PathResolverBase[ClassPath[AbstractFile], JavaClassPath](settings, context) {
 
-  def this(settings: Settings) =
-    this(settings,
-      if (settings.YnoLoadImplClass) PathResolver.NoImplClassJavaContext
-      else DefaultJavaContext)
+  def this(settings: Settings) = this(settings, DefaultJavaContext)
 
   override protected def computeResult(): JavaClassPath =
     new JavaClassPath(containers.toIndexedSeq, context)