Merge pull request scala#38 from noti0na1/dotty-explicit-nulls

Merge Changes from Dotty Upstream

Author: abeln

community-build/community-projects/scalatest

@@ -208,16 +208,13 @@ abstract class Positioned(implicit @constructorOnly src: SourceFile) extends Pro
       case tree: DefDef if tree.mods.is(Extension) =>
         tree.vparamss match {
           case vparams1 :: vparams2 :: rest if !isLeftAssoc(tree.name) =>
-            check(vparams2)
             check(tree.tparams)
+            check(vparams2)
             check(vparams1)
             check(rest)
-          case vparams1 :: rest =>
-            check(vparams1)
-            check(tree.tparams)
-            check(rest)
           case _ =>
             check(tree.tparams)
+            check(tree.vparamss)
         }
         check(tree.tpt)
         check(tree.rhs)

community-build/community-projects/shapeless

@@ -368,7 +368,8 @@ object Trees {
               // name (e.g. in a comment) before finding the real definition.
               // To make this behavior more robust we'd have to change the trees for definitions to contain
               // a fully positioned Ident in place of a name.
-              val idx = source.content().indexOfSlice(realName, point)
+              val contents = if source.exists then source.content() else Array.empty[Char]
+              val idx = contents.indexOfSlice(realName, point)
               if (idx >= 0) idx
               else point // use `point` anyway. This is important if no source exists so scanning fails
             }
@@ -754,9 +755,10 @@ object Trees {
     def unforced: LazyTree[T] = preRhs
     protected def force(x: Tree[T @uncheckedVariance]): Unit = preRhs = x
 
-    override def disableOverlapChecks = rawMods.is(Given)
-      // disable order checks for implicit aliases since their given clause follows
-      // their for clause, but the two appear swapped in the DefDef.
+    override def disableOverlapChecks = rawMods.is(Extension)
+      // disable order checks for extension methods as long as we parse
+      // type parameters both before and after the leading parameter section.
+      // TODO drop this once syntax of type parameters has settled.
   }
 
   /** mods class name template     or
@@ -789,10 +791,6 @@ object Trees {
 
     def parents: List[Tree[T]] = parentsOrDerived // overridden by DerivingTemplate
     def derived: List[untpd.Tree] = Nil           // overridden by DerivingTemplate
-
-    override def disableOverlapChecks = true
-      // disable overlaps checks since templates of instance definitions have their
-      // `given` clause come last, which means that the constructor span can contain the parent spans.
   }
 
 

compiler/src/dotty/tools/dotc/ast/Positioned.scala

@@ -182,6 +182,8 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
 
     case class Opaque()(implicit @constructorOnly src: SourceFile) extends Mod(Flags.Opaque)
 
+    case class Open()(implicit @constructorOnly src: SourceFile) extends Mod(Flags.Open)
+
     case class Override()(implicit @constructorOnly src: SourceFile) extends Mod(Flags.Override)
 
     case class Abstract()(implicit @constructorOnly src: SourceFile) extends Mod(Flags.Abstract)

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -205,7 +205,7 @@ trait ConstraintHandling[AbstractContext] {
     else
       isSubType(tp1, tp2)
 
-  @forceInline final def inFrozenConstraint[T](op: => T): T = {
+  inline final def inFrozenConstraint[T](op: => T): T = {
     val savedFrozen = frozenConstraint
     val savedLambda = caseLambda
     frozenConstraint = true

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -170,8 +170,8 @@ object Decorators {
       }
   }
 
-  implicit object reportDeco {
-    def (x: T) reporting[T](
+  implicit class reportDeco[T](x: T) extends AnyVal {
+    def reporting(
         op: (given WrappedResult[T]) => String,
         printer: config.Printers.Printer = config.Printers.default): T = {
       printer.println(op(given WrappedResult(x)))

compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala

@@ -43,10 +43,10 @@ class Definitions {
     ctx.newSymbol(owner, name, flags | Permanent, info)
 
   private def newClassSymbol(owner: Symbol, name: TypeName, flags: FlagSet, infoFn: ClassSymbol => Type) =
-    ctx.newClassSymbol(owner, name, flags | Permanent | NoInits, infoFn)
+    ctx.newClassSymbol(owner, name, flags | Permanent | NoInits | Open, infoFn)
 
   private def enterCompleteClassSymbol(owner: Symbol, name: TypeName, flags: FlagSet, parents: List[TypeRef], decls: Scope = newScope) =
-    ctx.newCompleteClassSymbol(owner, name, flags | Permanent | NoInits, parents, decls).entered
+    ctx.newCompleteClassSymbol(owner, name, flags | Permanent | NoInits | Open, parents, decls).entered
 
   private def enterTypeField(cls: ClassSymbol, name: TypeName, flags: FlagSet, scope: MutableScope) =
     scope.enter(newSymbol(cls, name, flags, TypeBounds.empty))
@@ -279,7 +279,7 @@ class Definitions {
     val cls = ctx.requiredClass("java.lang.Object")
     assert(!cls.isCompleted, "race for completing java.lang.Object")
     cls.info = ClassInfo(cls.owner.thisType, cls, AnyType :: Nil, newScope)
-    cls.setFlag(NoInits)
+    cls.setFlag(NoInits | JavaDefined)
 
     // The companion object doesn't really exist, so it needs to be marked as
     // absent. Here we need to set it before completing attempt to load Object's
@@ -780,7 +780,6 @@ class Definitions {
   @tu lazy val DeprecatedAnnot: ClassSymbol = ctx.requiredClass("scala.deprecated")
   @tu lazy val ImplicitAmbiguousAnnot: ClassSymbol = ctx.requiredClass("scala.annotation.implicitAmbiguous")
   @tu lazy val ImplicitNotFoundAnnot: ClassSymbol = ctx.requiredClass("scala.annotation.implicitNotFound")
-  @tu lazy val ForceInlineAnnot: ClassSymbol = ctx.requiredClass("scala.forceInline")
   @tu lazy val InlineParamAnnot: ClassSymbol = ctx.requiredClass("scala.annotation.internal.InlineParam")
   @tu lazy val InvariantBetweenAnnot: ClassSymbol = ctx.requiredClass("scala.annotation.internal.InvariantBetween")
   @tu lazy val MainAnnot: ClassSymbol = ctx.requiredClass("scala.main")

compiler/src/dotty/tools/dotc/core/Decorators.scala

@@ -37,7 +37,7 @@ object Flags {
       else {
         val tbits = x.bits & y.bits & KINDFLAGS
         if (tbits == 0)
-          assert(false, s"illegal flagset combination: $x and $y")
+          assert(false, s"illegal flagset combination: ${x.flagsString} and ${y.flagsString}")
         FlagSet(tbits | ((x.bits | y.bits) & ~KINDFLAGS))
       }
 
@@ -237,8 +237,8 @@ object Flags {
   /** A value or variable accessor (getter or setter) */
   val (AccessorOrSealed @ _, Accessor @ _, Sealed @ _) = newFlags(11, "<accessor>", "sealed")
 
-  /** A mutable var */
-  val (_, Mutable @ _, _) = newFlags(12, "mutable")
+  /** A mutable var, an open class */
+  val (MutableOrOpen @ __, Mutable @ _, Open @ _) = newFlags(12, "mutable", "open")
 
   /** Symbol is local to current class (i.e. private[this] or protected[this]
    *  pre: Private or Protected are also set
@@ -422,7 +422,7 @@ object Flags {
     commonFlags(Private, Protected, Final, Case, Implicit, Given, Override, JavaStatic)
 
   val TypeSourceModifierFlags: FlagSet =
-    CommonSourceModifierFlags.toTypeFlags | Abstract | Sealed | Opaque
+    CommonSourceModifierFlags.toTypeFlags | Abstract | Sealed | Opaque | Open
 
   val TermSourceModifierFlags: FlagSet =
     CommonSourceModifierFlags.toTermFlags | Inline | AbsOverride | Lazy | Erased
@@ -439,7 +439,7 @@ object Flags {
   val FromStartFlags: FlagSet = commonFlags(
     Module, Package, Deferred, Method, Case,
     HigherKinded, Param, ParamAccessor,
-    Scala2ExistentialCommon, Mutable, Opaque, Touched, JavaStatic,
+    Scala2ExistentialCommon, MutableOrOpen, Opaque, Touched, JavaStatic,
     OuterOrCovariant, LabelOrContravariant, CaseAccessor,
     Extension, NonMember, Implicit, Given, Permanent, Synthetic,
     SuperAccessorOrScala2x, Inline, Macro)
@@ -513,12 +513,16 @@ object Flags {
   /** Flags retained in export forwarders */
   val RetainedExportFlags = Given | Implicit | Extension
 
+  /** Flags that apply only to classes */
+  val ClassOnlyFlags = Sealed | Open | Abstract.toTypeFlags
+
 // ------- Other flag sets -------------------------------------
 
   val AbstractFinal: FlagSet                 = Abstract | Final
   val AbstractOverride: FlagSet              = Abstract | Override
   val AbstractSealed: FlagSet                = Abstract | Sealed
   val AbstractOrTrait: FlagSet               = Abstract | Trait
+  val EffectivelyOpenFlags                   = Abstract | JavaDefined | Open | Scala2x | Trait
   val PrivateAccessor: FlagSet               = Accessor | Private
   val AccessorOrSynthetic: FlagSet           = Accessor | Synthetic
   val EnumCase: FlagSet                      = Case | Enum

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -368,8 +368,8 @@ object StdNames {
     val TypeApply: N            = "TypeApply"
     val TypeRef: N              = "TypeRef"
     val UNIT : N                = "UNIT"
-    val add_ : N                = "add"
     val acc: N                  = "acc"
+    val adhocExtensions: N      = "adhocExtensions"
     val annotation: N           = "annotation"
     val any2stringadd: N        = "any2stringadd"
     val anyHash: N              = "anyHash"
@@ -507,6 +507,7 @@ object StdNames {
     val nullExpr: N             = "nullExpr"
     val ofDim: N                = "ofDim"
     val opaque: N               = "opaque"
+    val open: N                 = "open"
     val ordinal: N              = "ordinal"
     val ordinalDollar: N        = "$ordinal"
     val ordinalDollar_ : N      = "_$ordinal"

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -926,17 +926,10 @@ object SymDenotations {
     /** Is this a Scala 2 macro */
     final def isScala2Macro(implicit ctx: Context): Boolean = is(Macro) && symbol.owner.is(Scala2x)
 
-    /** An erased value or an inline method, excluding @forceInline annotated methods.
-     *  The latter have to be kept around to get to parity with Scala.
-     *  This is necessary at least until we have full bootstrap. Right now
-     *  dotty-bootstrapped involves running the Dotty compiler compiled with Scala 2 with
-     *  a Dotty runtime library compiled with Dotty. If we erase @forceInline annotated
-     *  methods, this means that the support methods in dotty.runtime.LazyVals vanish.
-     *  But they are needed for running the lazy val implementations in the Scala-2 compiled compiler.
+    /** An erased value or an inline method.
      */
     def isEffectivelyErased(implicit ctx: Context): Boolean =
-      is(Erased) ||
-      isInlineMethod && unforcedAnnotation(defn.ForceInlineAnnot).isEmpty
+      is(Erased) || isInlineMethod
 
     /** ()T and => T types should be treated as equivalent for this symbol.
      *  Note: For the moment, we treat Scala-2 compiled symbols as loose matching,
@@ -1079,6 +1072,12 @@ object SymDenotations {
     final def isEffectivelyFinal(implicit ctx: Context): Boolean =
       isOneOf(EffectivelyFinalFlags) || !owner.isClass || owner.isOneOf(FinalOrModuleClass) || owner.isAnonymousClass
 
+    /** A class is effectively sealed if has the `final` or `sealed` modifier, or it
+     *  is defined in Scala 3 and is neither abstract nor open.
+     */
+    final def isEffectivelySealed(given Context): Boolean =
+      isOneOf(FinalOrSealed) || isClass && !isOneOf(EffectivelyOpenFlags)
+
     /** The class containing this denotation which has the given effective name. */
     final def enclosingClassNamed(name: Name)(implicit ctx: Context): Symbol = {
       val cls = enclosingClass
@@ -1377,16 +1376,16 @@ object SymDenotations {
      */
     def typeParamCreationFlags: FlagSet = TypeParam
 
-    override def toString: String = {
-      val kindString =
-        if (myFlags.is(ModuleClass)) "module class"
-        else if (isClass) "class"
-        else if (isType) "type"
-        else if (myFlags.is(Module)) "module"
-        else if (myFlags.is(Method)) "method"
-        else "val"
-      s"$kindString $name"
-    }
+    def kindString: String =
+      if myFlags.is(ModuleClass) then "module class"
+      else if myFlags.is(Trait)  then "trait"
+      else if isClass            then "class"
+      else if isType             then "type"
+      else if myFlags.is(Module) then "module"
+      else if myFlags.is(Method) then "method"
+      else                            "val"
+
+    override def toString: String = s"$kindString $name"
 
     // ----- Sanity checks and debugging */
 

compiler/src/dotty/tools/dotc/core/StdNames.scala

@@ -908,6 +908,6 @@ object Symbols {
     override def toString: String = value.asScala.toString()
   }
 
-  @forceInline def newMutableSymbolMap[T]: MutableSymbolMap[T] =
+  inline def newMutableSymbolMap[T]: MutableSymbolMap[T] =
     new MutableSymbolMap(new java.util.IdentityHashMap[Symbol, T]())
 }

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -4523,7 +4523,7 @@ object Types {
   abstract class VariantTraversal {
     protected[core] var variance: Int = 1
 
-    @forceInline protected def atVariance[T](v: Int)(op: => T): T = {
+    inline protected def atVariance[T](v: Int)(op: => T): T = {
       val saved = variance
       variance = v
       val res = op

compiler/src/dotty/tools/dotc/core/Symbols.scala

@@ -211,6 +211,7 @@ Standard-Section: "ASTs" TopLevelStat*
                   EXTENSION                                                        -- An extension method
                   PARAMsetter                                                      -- The setter part `x_=` of a var parameter `x` which itself is pickled as a PARAM
                   EXPORTED                                                         -- An export forwarder
+                  OPEN                                                             -- an open class
                   Annotation
 
   Annotation    = ANNOTATION     Length tycon_Type fullAnnotation_Term             -- An annotation, given (class) type of constructor, and full application tree
@@ -332,6 +333,7 @@ object TastyFormat {
   final val GIVEN = 37
   final val PARAMsetter = 38
   final val EXPORTED = 39
+  final val OPEN = 40
 
   // Cat. 2:    tag Nat
 
@@ -460,7 +462,7 @@ object TastyFormat {
 
   /** Useful for debugging */
   def isLegalTag(tag: Int): Boolean =
-    firstSimpleTreeTag <= tag && tag <= EXPORTED ||
+    firstSimpleTreeTag <= tag && tag <= OPEN ||
     firstNatTreeTag <= tag && tag <= RENAMED ||
     firstASTTreeTag <= tag && tag <= BOUNDED ||
     firstNatASTTreeTag <= tag && tag <= NAMEDARG ||
@@ -505,6 +507,7 @@ object TastyFormat {
        | GIVEN
        | PARAMsetter
        | EXPORTED
+       | OPEN
        | ANNOTATION
        | PRIVATEqualified
        | PROTECTEDqualified => true
@@ -565,6 +568,7 @@ object TastyFormat {
     case GIVEN => "GIVEN"
     case PARAMsetter => "PARAMsetter"
     case EXPORTED => "EXPORTED"
+    case OPEN => "OPEN"
 
     case SHAREDterm => "SHAREDterm"
     case SHAREDtype => "SHAREDtype"

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -669,6 +669,7 @@ class TreePickler(pickler: TastyPickler) {
       if (flags.is(Covariant)) writeModTag(COVARIANT)
       if (flags.is(Contravariant)) writeModTag(CONTRAVARIANT)
       if (flags.is(Opaque)) writeModTag(OPAQUE)
+      if (flags.is(Open)) writeModTag(OPEN)
     }
   }
 

compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala

@@ -631,6 +631,7 @@ class TreeUnpickler(reader: TastyReader,
           case GIVEN => addFlag(Given)
           case PARAMsetter => addFlag(ParamAccessor)
           case EXPORTED => addFlag(Exported)
+          case OPEN => addFlag(Open)
           case PRIVATEqualified =>
             readByte()
             privateWithin = readWithin(ctx)
@@ -890,9 +891,9 @@ class TreeUnpickler(reader: TastyReader,
           untpd.ValDef(readName(), readTpt(), EmptyTree).withType(NoType)
         }
         else EmptyValDef
+      cls.setNoInitsFlags(parentsKind(parents), bodyFlags)
       cls.info = ClassInfo(cls.owner.thisType, cls, parentTypes, cls.unforcedDecls,
         if (self.isEmpty) NoType else self.tpt.tpe)
-      cls.setNoInitsFlags(parentsKind(parents), bodyFlags)
       val constr = readIndexedDef().asInstanceOf[DefDef]
       val mappedParents = parents.map(_.changeOwner(localDummy, constr.symbol))