Add default getter names

Plus various bug fixes and filling in missing functionality

9 files changed, 169 insertions, 57 deletions

diff --git a/compiler/src/dotty/tools/dotc/core/NameInfos.scala b/compiler/src/dotty/tools/dotc/core/NameInfos.scala
index daaa5c4e1..c5b83b0dc 100644
--- a/compiler/src/dotty/tools/dotc/core/NameInfos.scala
+++ b/compiler/src/dotty/tools/dotc/core/NameInfos.scala
@@ -2,6 +2,7 @@ package dotty.tools.dotc
 package core
 
 import Names._
+import NameOps._
 import StdNames._
 
 /** Additional info associated with a name. At a minimum its kind and
@@ -20,6 +21,7 @@ object NameInfo {
   val TermNameKind = 0
   val QualifiedKind = 1
   val ModuleClassKind = 2
+  val DefaultGetterKind = 3
 
   val qualifier: Map[String, SimpleTermName => Qualified] =
     Map("."  -> Select,
@@ -43,7 +45,7 @@ object NameInfo {
     def kind = QualifiedKind
     override def map(f: SimpleTermName => SimpleTermName): NameInfo = newLikeThis(f(name))
     def mkString(underlying: TermName) = s"$underlying$separator$name"
-    override def toString = s"$getClass($name)"
+    override def toString = s"${getClass.getSimpleName}($name)"
   }
 
   case class Select(val name: SimpleTermName) extends Qualified {
@@ -66,6 +68,19 @@ object NameInfo {
     def newLikeThis(name: SimpleTermName) = TraitSetter(name)
   }
 
+  trait Numbered extends NameInfo {
+    def num: Int
+    override def toString = s"${getClass.getSimpleName}($num)"
+  }
+
+  case class DefaultGetter(val num: Int) extends Numbered {
+    def kind = DefaultGetterKind
+    def mkString(underlying: TermName) = {
+      val prefix = if (underlying.isConstructorName) nme.DEFAULT_GETTER_INIT else underlying
+      prefix.toString + nme.DEFAULT_GETTER + (num + 1)
+    }
+  }
+
   val ModuleClass = new NameInfo {
     def kind = ModuleClassKind
     def mkString(underlying: TermName) = underlying + "$"
diff --git a/compiler/src/dotty/tools/dotc/core/NameOps.scala b/compiler/src/dotty/tools/dotc/core/NameOps.scala
index 65669a871..eb284168a 100644
--- a/compiler/src/dotty/tools/dotc/core/NameOps.scala
+++ b/compiler/src/dotty/tools/dotc/core/NameOps.scala
@@ -102,8 +102,10 @@ object NameOps {
     def isOpAssignmentName: Boolean = name match {
       case raw.NE | raw.LE | raw.GE | EMPTY =>
         false
-      case _ =>
+      case name: SimpleTermName =>
         name.length > 0 && name.last == '=' && name.head != '=' && isOperatorPart(name.head)
+      case _ =>
+        false
     }
 
     /** If the name ends with $nn where nn are
@@ -164,7 +166,8 @@ object NameOps {
     def expandedName(prefix: Name, separator: Name = nme.EXPAND_SEPARATOR): N =
       likeTyped(
         if (Config.semanticNames)
-          prefix.derived(NameInfo.qualifier(separator.toString)(name.asSimpleName))
+          prefix.derived(NameInfo.qualifier(separator.toString)(name.toSimpleName))
+            // note: expanded name may itself be expanded. For example, look at javap of scala.App.initCode
         else prefix ++ separator ++ name)
 
     def expandedName(prefix: Name): N = expandedName(prefix, nme.EXPAND_SEPARATOR)
@@ -247,7 +250,7 @@ object NameOps {
 */
     def unmangleClassName: N =
       if (Config.semanticNames && name.isSimple && name.isTypeName)
-        if (name.endsWith(MODULE_SUFFIX))
+        if (name.endsWith(MODULE_SUFFIX) && !tpnme.falseModuleClassNames.contains(name.asTypeName))
           likeTyped(name.dropRight(MODULE_SUFFIX.length).moduleClassName)
         else name
       else name
@@ -404,44 +407,60 @@ object NameOps {
       if (name.isSetterName) {
         if (name.isTraitSetterName) {
           // has form <$-separated-trait-name>$_setter_$ `name`_$eq
-          val start = name.indexOfSlice(TRAIT_SETTER_SEPARATOR) + TRAIT_SETTER_SEPARATOR.length
-          val end = name.indexOfSlice(SETTER_SUFFIX)
-          (name.slice(start, end) ++ LOCAL_SUFFIX).asTermName
+          val start = name.lastPart.indexOfSlice(TRAIT_SETTER_SEPARATOR) + TRAIT_SETTER_SEPARATOR.length
+          val end = name.lastPart.indexOfSlice(SETTER_SUFFIX)
+          name.mapLast(n => (n.slice(start, end) ++ LOCAL_SUFFIX).asSimpleName)
         } else getterName.fieldName
       }
-      else name ++ LOCAL_SUFFIX
+      else name.mapLast(n => (n ++ LOCAL_SUFFIX).asSimpleName)
 
     private def setterToGetter: TermName = {
       assert(name.endsWith(SETTER_SUFFIX), name + " is referenced as a setter but has wrong name format")
-      name.take(name.length - SETTER_SUFFIX.length).asTermName
+      name.mapLast(n => n.take(n.length - SETTER_SUFFIX.length).asSimpleName)
     }
 
     def fieldToGetter: TermName = {
       assert(name.isFieldName)
-      name.take(name.length - LOCAL_SUFFIX.length).asTermName
+      name.mapLast(n => n.take(n.length - LOCAL_SUFFIX.length).asSimpleName)
     }
 
     /** Nominally, name$default$N, encoded for <init>
      *  @param  Post the parameters position.
      *  @note Default getter name suffixes start at 1, so `pos` has to be adjusted by +1
      */
-    def defaultGetterName(pos: Int): TermName = {
-      val prefix = if (name.isConstructorName) DEFAULT_GETTER_INIT else name
-      prefix ++ DEFAULT_GETTER ++ (pos + 1).toString
-    }
+    def defaultGetterName(pos: Int): TermName =
+      if (Config.semanticNames) name.derived(NameInfo.DefaultGetter(pos))
+      else {
+        val prefix = if (name.isConstructorName) DEFAULT_GETTER_INIT else name
+        prefix ++ DEFAULT_GETTER ++ (pos + 1).toString
+      }
 
     /** Nominally, name from name$default$N, CONSTRUCTOR for <init> */
-    def defaultGetterToMethod: TermName = {
-      val p = name.indexOfSlice(DEFAULT_GETTER)
-      if (p >= 0) {
-        val q = name.take(p).asTermName
-        // i.e., if (q.decoded == CONSTRUCTOR.toString) CONSTRUCTOR else q
-        if (q == DEFAULT_GETTER_INIT) CONSTRUCTOR else q
-      } else name
+    def defaultGetterToMethod: TermName =
+      if (Config.semanticNames)
+        name rewrite {
+          case DerivedTermName(methName, NameInfo.DefaultGetter(_)) => methName
+        }
+      else mangledDefaultGetterToMethod
+
+    def mangledDefaultGetterToMethod: TermName = {
+        val p = name.indexOfSlice(DEFAULT_GETTER)
+        if (p >= 0) {
+          val q = name.take(p).asTermName
+          // i.e., if (q.decoded == CONSTRUCTOR.toString) CONSTRUCTOR else q
+          if (q == DEFAULT_GETTER_INIT) CONSTRUCTOR else q
+        } else name
     }
 
     /** If this is a default getter, its index (starting from 0), else -1 */
-    def defaultGetterIndex: Int = {
+    def defaultGetterIndex: Int =
+      if (Config.semanticNames)
+        name collect {
+          case DerivedTermName(methName, NameInfo.DefaultGetter(num)) => num
+        } getOrElse -1
+      else mangledDefaultGetterIndex
+
+    def mangledDefaultGetterIndex: Int = {
       var i = name.length
       while (i > 0 && name(i - 1).isDigit) i -= 1
       if (i > 0 && i < name.length && name.take(i).endsWith(DEFAULT_GETTER))
@@ -529,6 +548,14 @@ object NameOps {
     }
 
     def inlineAccessorName = nme.INLINE_ACCESSOR_PREFIX ++ name ++ "$"
+
+    def unmangleMethodName: TermName =
+      if (Config.semanticNames && name.isSimple) {
+        val idx = name.mangledDefaultGetterIndex
+        if (idx >= 0) name.mangledDefaultGetterToMethod.defaultGetterName(idx)
+        else name
+      }
+      else name
   }
 
   private final val FalseSuper = "$$super".toTermName
diff --git a/compiler/src/dotty/tools/dotc/core/Names.scala b/compiler/src/dotty/tools/dotc/core/Names.scala
index 84b2fab0c..22d0588f4 100644
--- a/compiler/src/dotty/tools/dotc/core/Names.scala
+++ b/compiler/src/dotty/tools/dotc/core/Names.scala
@@ -66,6 +66,9 @@ object Names {
     def asSimpleName: SimpleTermName
     def toSimpleName: SimpleTermName
     def rewrite(f: PartialFunction[Name, Name]): ThisName
+    def collect[T](f: PartialFunction[Name, T]): Option[T]
+    def mapLast(f: SimpleTermName => SimpleTermName): ThisName
+    def mapParts(f: SimpleTermName => SimpleTermName): ThisName
 
     /** A name of the same kind as this name and with same characters as given `name` */
     def likeKinded(name: Name): ThisName
@@ -88,9 +91,8 @@ object Names {
 
     /** A more efficient version of concatenation */
     def ++ (other: Name): ThisName = ++ (other.toString)
-    def ++ (other: String): ThisName
-
-    def replace(from: Char, to: Char): ThisName = likeKinded(asSimpleName.replace(from, to))
+    def ++ (other: String): ThisName = mapLast(n => termName(n.toString + other))
+    def replace(from: Char, to: Char): ThisName = mapParts(_.replace(from, to))
 
     def isEmpty: Boolean
 
@@ -198,8 +200,6 @@ object Names {
 
     def apply(n: Int) = chrs(start + n)
 
-    def ++ (other: String): SimpleTermName = termName(toString + other)
-
     private def contains(ch: Char): Boolean = {
       var i = 0
       while (i < length && chrs(start + i) != ch) i += 1
@@ -220,19 +220,29 @@ object Names {
       i > str.length
     }
 
-    override def replace(from: Char, to: Char): ThisName = {
+    override def replace(from: Char, to: Char): SimpleTermName = {
       val cs = new Array[Char](length)
       Array.copy(chrs, start, cs, 0, length)
       for (i <- 0 until length) {
         if (cs(i) == from) cs(i) = to
       }
-      likeKinded(termName(cs, 0, length))
+      termName(cs, 0, length)
     }
 
     def isSimple = true
     def asSimpleName = this
     def toSimpleName = this
-    def rewrite(f: PartialFunction[Name, Name]): ThisName = likeKinded(f(this))
+    def rewrite(f: PartialFunction[Name, Name]): ThisName =
+      if (f.isDefinedAt(this)) likeKinded(f(this)) else this
+    def collect[T](f: PartialFunction[Name, T]): Option[T] = f.lift(this)
+    def mapLast(f: SimpleTermName => SimpleTermName) = f(this)
+    def mapParts(f: SimpleTermName => SimpleTermName) = f(this)
+
+    /*def exists(p: Char => Boolean): Boolean = {
+      var i = 0
+      while (i < length && !p(chrs(start + i))) i += 1
+      i < length
+    }*/
 
     def encode: SimpleTermName =
       if (dontEncode(toTermName)) this else NameTransformer.encode(this)
@@ -254,8 +264,6 @@ object Names {
 
   class TypeName(val toTermName: TermName) extends Name {
 
-    def ++ (other: String): ThisName = toTermName.++(other).toTypeName
-
     def isEmpty = toTermName.isEmpty
 
     def encode   = toTermName.encode.toTypeName
@@ -274,6 +282,9 @@ object Names {
     def asSimpleName = toTermName.asSimpleName
     def toSimpleName = toTermName.toSimpleName
     def rewrite(f: PartialFunction[Name, Name]): ThisName = toTermName.rewrite(f).toTypeName
+    def collect[T](f: PartialFunction[Name, T]): Option[T] = toTermName.collect(f)
+    def mapLast(f: SimpleTermName => SimpleTermName) = toTermName.mapLast(f).toTypeName
+    def mapParts(f: SimpleTermName => SimpleTermName) = toTermName.mapParts(f).toTypeName
 
     def likeKinded(name: Name): TypeName = name.toTypeName
 
@@ -298,10 +309,6 @@ object Names {
       case qual: NameInfo.Qualified => qual.name
       case _ => underlying.lastPart
     }
-    def ++ (other: String): ThisName = info match {
-      case qual: NameInfo.Qualified => underlying.derived(qual.map(_ ++ other))
-      case _ => (underlying ++ other).derived(info)
-    }
     override def toString = info.mkString(underlying)
     override def debugString = s"${underlying.debugString}[$info]"
 
@@ -315,6 +322,25 @@ object Names {
         case qual: NameInfo.Qualified => this
         case _ => underlying.rewrite(f).derived(info)
       }
+
+    def collect[T](f: PartialFunction[Name, T]): Option[T] =
+      if (f.isDefinedAt(this)) Some(f(this))
+      else info match {
+        case qual: NameInfo.Qualified => None
+        case _ => underlying.collect(f)
+      }
+
+    def mapLast(f: SimpleTermName => SimpleTermName): ThisName =
+      info match {
+        case qual: NameInfo.Qualified => underlying.derived(qual.map(f))
+        case _ => underlying.mapLast(f).derived(info)
+      }
+
+    def mapParts(f: SimpleTermName => SimpleTermName): ThisName =
+      info match {
+        case qual: NameInfo.Qualified => underlying.mapParts(f).derived(qual.map(f))
+        case _ => underlying.mapParts(f).derived(info)
+      }
   }
 
   // Nametable
@@ -478,23 +504,54 @@ object Names {
   }
 
   implicit val NameOrdering: Ordering[Name] = new Ordering[Name] {
+    private def compareInfos(x: NameInfo, y: NameInfo): Int =
+      if (x.kind != y.kind) x.kind - y.kind
+      else x match {
+        case x: NameInfo.Qualified =>
+          y match {
+            case y: NameInfo.Qualified =>
+              val s = x.separator.compareTo(y.separator)
+              if (s == 0) compareSimpleNames(x.name, y.name) else s
+          }
+        case x: NameInfo.Numbered =>
+          y match {
+            case y: NameInfo.Numbered =>
+              x.num - y.num
+          }
+        case _ =>
+          assert(x == y)
+          0
+      }
+    private def compareSimpleNames(x: SimpleTermName, y: SimpleTermName): Int = {
+      val until = x.length min y.length
+      var i = 0
+      while (i < until && x(i) == y(i)) i = i + 1
+      if (i < until) {
+        if (x(i) < y(i)) -1
+        else /*(x(i) > y(i))*/ 1
+      } else {
+        x.length - y.length
+      }
+    }
+    private def compareTermNames(x: TermName, y: TermName): Int = x match {
+      case x: SimpleTermName =>
+        y match {
+          case y: SimpleTermName => compareSimpleNames(x, y)
+          case _ => -1
+        }
+      case DerivedTermName(xPre, xInfo) =>
+        y match {
+          case DerivedTermName(yPre, yInfo) =>
+            val s = compareInfos(xInfo, yInfo)
+            if (s == 0) compareTermNames(xPre, yPre) else s
+          case _ => 1
+        }
+    }
     def compare(x: Name, y: Name): Int = {
       if (x.isTermName && y.isTypeName) 1
       else if (x.isTypeName && y.isTermName) -1
       else if (x eq y) 0
-      else {
-        val until = x.length min y.length
-        var i = 0
-
-        while (i < until && x(i) == y(i)) i = i + 1
-
-        if (i < until) {
-          if (x(i) < y(i)) -1
-          else /*(x(i) > y(i))*/ 1
-        } else {
-          x.length - y.length
-        }
-      }
+      else compareTermNames(x.toTermName, y.toTermName)
     }
   }
 }
diff --git a/compiler/src/dotty/tools/dotc/core/StdNames.scala b/compiler/src/dotty/tools/dotc/core/StdNames.scala
index 9e05d4bce..1a65556ba 100644
--- a/compiler/src/dotty/tools/dotc/core/StdNames.scala
+++ b/compiler/src/dotty/tools/dotc/core/StdNames.scala
@@ -546,6 +546,11 @@ object StdNames {
     val synthSwitch: N          = "$synthSwitch"
     val _scope: N               = "$scope"
 
+    val nothingClass: N         = "Nothing$"
+    val nullClass: N            = "Null$"
+    
+    val falseModuleClassNames = Set(nothingClass, nullClass, nothingRuntimeClass, nullRuntimeClass)
+
     // unencoded operators
     object raw {
       final val AMP  : N  = "&"
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/NameBuffer.scala b/compiler/src/dotty/tools/dotc/core/tasty/NameBuffer.scala
index 7ac505a20..b45255eb8 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/NameBuffer.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/NameBuffer.scala
@@ -36,6 +36,8 @@ class NameBuffer extends TastyBuffer(10000) {
           case _: NameInfo.Expand => Expanded
         }
         tcon(nameIndex(prefix, toTasty), nameIndex(qual.name))
+      case DerivedTermName(prefix, NameInfo.DefaultGetter(num)) =>
+        DefaultGetter(nameIndex(prefix, toTasty), num)
       case name1 =>
         if (name1.isShadowedName) Shadowed(nameIndex(name1.revertShadowed, toTasty))
         else toTasty(name1.asSimpleName)
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
index 06165c6f4..d4269d6e4 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
@@ -90,7 +90,7 @@ class TreeUnpickler(reader: TastyReader, tastyName: TastyName.Table, posUnpickle
     case Shadowed(original) => toTermName(original).shadowedName
     case ModuleClass(original) => toTermName(original).moduleClassName.toTermName
     case SuperAccessor(accessed) => toTermName(accessed).superName
-    case DefaultGetter(meth, num) => ???
+    case DefaultGetter(meth, num) => toTermName(meth).defaultGetterName(num)
   }
 
   private def qualTermName(qual: NameRef, name: NameRef, sep: String) =
diff --git a/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala b/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
index a49379327..084b8d098 100644
--- a/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
@@ -433,7 +433,10 @@ class Scala2Unpickler(bytes: Array[Byte], classRoot: ClassDenotation, moduleClas
 
     val name1 = name0.adjustIfModuleClass(flags)
     val name2 = if (name1 == nme.TRAIT_CONSTRUCTOR) nme.CONSTRUCTOR else name1
-    val name = if (flags is ModuleClass) name2.unmangleClassName else name2
+    val name =
+      if (flags is ModuleClass) name2.unmangleClassName
+      else if (flags is Method) name2.asTermName.unmangleMethodName
+      else name2
 
     def isClassRoot = (name == classRoot.name) && (owner == classRoot.owner) && !(flags is ModuleClass)
     def isModuleClassRoot = (name == moduleClassRoot.name) && (owner == moduleClassRoot.owner) && (flags is Module)
diff --git a/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala b/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
index 3a301167d..b6c28f570 100644
--- a/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
@@ -18,6 +18,7 @@ import util.Positions._
 import Names._
 import collection.mutable
 import ResolveSuper._
+import config.Config
 
 /** This phase adds super accessors and method overrides where
  *  linearization differs from Java's rule for default methods in interfaces.
@@ -95,10 +96,12 @@ object ResolveSuper {
     var bcs = base.info.baseClasses.dropWhile(acc.owner != _).tail
     var sym: Symbol = NoSymbol
     val unexpandedAccName =
-      if (acc.is(ExpandedName))  // Cannot use unexpandedName because of #765. t2183.scala would fail if we did.
-        acc.name
-          .drop(acc.name.indexOfSlice(nme.EXPAND_SEPARATOR ++ nme.SUPER_PREFIX))
-          .drop(nme.EXPAND_SEPARATOR.length)
+      if (acc.is(ExpandedName))
+        if (Config.semanticNames) acc.name.unexpandedName
+        else // Cannot use unexpandedName because of #765. t2183.scala would fail if we did.
+          acc.name
+           .drop(acc.name.indexOfSlice(nme.EXPAND_SEPARATOR ++ nme.SUPER_PREFIX))
+           .drop(nme.EXPAND_SEPARATOR.length)
       else acc.name
     val SuperAccessorName(memberName) = unexpandedAccName: Name // dotty deviation: ": Name" needed otherwise pattern type is neither a subtype nor a supertype of selector type
     ctx.debuglog(i"starting rebindsuper from $base of ${acc.showLocated}: ${acc.info} in $bcs, name = $memberName")
diff --git a/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala b/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
index ebb5b605b..199fac82b 100644
--- a/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
@@ -50,10 +50,10 @@ class TreeChecker extends Phase with SymTransformer {
   private val seenModuleVals = collection.mutable.HashMap[String, Symbol]()
 
   def isValidJVMName(name: Name) =
-      !name.exists(c => c == '.' || c == ';' || c =='[' || c == '/')
+      !name.toString.exists(c => c == '.' || c == ';' || c =='[' || c == '/')
 
   def isValidJVMMethodName(name: Name) =
-      !name.exists(c => c == '.' || c == ';' || c =='[' || c == '/' || c == '<' || c == '>')
+      !name.toString.exists(c => c == '.' || c == ';' || c =='[' || c == '/' || c == '<' || c == '>')
 
   def printError(str: String)(implicit ctx: Context) = {
     ctx.echo(Console.RED + "[error] " + Console.WHITE  + str)