Revise qualified names

1. Fix problem in fullNameSeparated
2. Revise expandedName operations

8 files changed, 63 insertions, 87 deletions

diff --git a/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala b/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
index 10288a4be..7ef6b7ef9 100644
--- a/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
+++ b/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
@@ -557,8 +557,7 @@ class DottyBackendInterface(outputDirectory: AbstractFile, val superCallsMap: Ma
     def fullName: String = sym.showFullName
     def simpleName: Name = sym.name
     def javaSimpleName: Name = toDenot(sym).name // addModuleSuffix(simpleName.dropLocal)
-    def javaBinaryName: Name = toDenot(sym).fullNameSeparated("/").unmangleClassName // addModuleSuffix(fullNameInternal('/'))
-      // We use `unmangleClassName` so that `stripModuleClassSuffix` works as expected.
+    def javaBinaryName: Name = javaClassName.replace('.', '/').toTermName // TODO: can we make this a string? addModuleSuffix(fullNameInternal('/'))
     def javaClassName: String = toDenot(sym).fullName.toString// addModuleSuffix(fullNameInternal('.')).toString
     def name: Name = sym.name
     def rawname: Name = {
diff --git a/compiler/src/dotty/tools/dotc/core/NameKinds.scala b/compiler/src/dotty/tools/dotc/core/NameKinds.scala
index eea5aefe3..381bb3fc0 100644
--- a/compiler/src/dotty/tools/dotc/core/NameKinds.scala
+++ b/compiler/src/dotty/tools/dotc/core/NameKinds.scala
@@ -14,8 +14,8 @@ import collection.mutable
 object NameKinds {
 
   @sharable private val simpleNameKinds = new mutable.HashMap[Int, ClassifiedNameKind]
+  @sharable private val qualifiedNameKinds = new mutable.HashMap[Int, QualifiedNameKind]
   @sharable private val uniqueNameKinds = new mutable.HashMap[String, UniqueNameKind]
-  @sharable private val qualifiedNameKinds = new mutable.HashMap[String, QualifiedNameKind]
 
   abstract class NameInfo extends DotClass {
     def kind: NameKind
@@ -83,8 +83,18 @@ object NameKinds {
       override def map(f: SimpleTermName => SimpleTermName): NameInfo = new QualInfo(f(name))
       override def toString = s"$infoString $name"
     }
-    def apply(qual: TermName, name: SimpleTermName) =
+    def apply(qual: TermName, name: SimpleTermName): TermName =
       qual.derived(new QualInfo(name))
+
+    /** Overloaded version used only for ExpandedName and TraitSetterName.
+     *  Needed because the suffix of an expanded name may itself be expanded.
+     *  For example, look at javap of scala.App.initCode
+     */
+    def apply(qual: TermName, name: TermName): TermName = name rewrite {
+      case name: SimpleTermName => apply(qual, name)
+      case AnyQualifiedName(_, _) => apply(qual, name.toSimpleName)
+    }
+
     def unapply(name: DerivedTermName): Option[(TermName, SimpleTermName)] = name match {
       case DerivedTermName(qual, info: this.QualInfo) => Some((qual, info.name))
       case _ => None
@@ -96,7 +106,7 @@ object NameKinds {
       s"$underlying$separator${info.name}"
     def infoString = s"Qualified $separator"
 
-    qualifiedNameKinds(separator) = this
+    qualifiedNameKinds(tag) = this
   }
 
   object AnyQualifiedName {
@@ -150,8 +160,8 @@ object NameKinds {
   }
 
   val QualifiedName           = new QualifiedNameKind(QUALIFIED, ".")
-  val FlattenedName           = new QualifiedNameKind(FLATTENED, "$")
-  val TraitSetterName         = new QualifiedNameKind(TRAITSETTER, str.TRAIT_SETTER_SEPARATOR)
+  val FlatName                = new QualifiedNameKind(FLATTENED, "$")
+  val ExpandPrefixName        = new QualifiedNameKind(EXPANDPREFIX, "$")
 
   val ExpandedName = new QualifiedNameKind(EXPANDED, str.EXPAND_SEPARATOR) {
     private val FalseSuper = "$$super".toTermName
@@ -172,6 +182,8 @@ object NameKinds {
     }
   }
 
+  val TraitSetterName         = new QualifiedNameKind(TRAITSETTER, str.TRAIT_SETTER_SEPARATOR)
+
   val UniqueName = new UniqueNameKind("$") {
     override def mkString(underlying: TermName, info: ThisInfo) =
       if (underlying.isEmpty) "$" + info.num + "$" else super.mkString(underlying, info)
@@ -260,7 +272,7 @@ object NameKinds {
   val Scala2MethodNameKinds: List[NameKind] =
     List(DefaultGetterName, ProtectedAccessorName, ProtectedSetterName)
 
-  def simpleNameKindOfTag         : collection.Map[Int, ClassifiedNameKind]   = simpleNameKinds
-  def qualifiedNameKindOfSeparator: collection.Map[String, QualifiedNameKind] = qualifiedNameKinds
-  def uniqueNameKindOfSeparator   : collection.Map[String, UniqueNameKind]    = uniqueNameKinds
+  def simpleNameKindOfTag      : collection.Map[Int, ClassifiedNameKind] = simpleNameKinds
+  def qualifiedNameKindOfTag   : collection.Map[Int, QualifiedNameKind]  = qualifiedNameKinds
+  def uniqueNameKindOfSeparator: collection.Map[String, UniqueNameKind]  = uniqueNameKinds
 }
\ No newline at end of file
diff --git a/compiler/src/dotty/tools/dotc/core/NameOps.scala b/compiler/src/dotty/tools/dotc/core/NameOps.scala
index 8d5344d8a..01ce4807c 100644
--- a/compiler/src/dotty/tools/dotc/core/NameOps.scala
+++ b/compiler/src/dotty/tools/dotc/core/NameOps.scala
@@ -59,10 +59,8 @@ object NameOps {
     def isStaticConstructorName = name == STATIC_CONSTRUCTOR
     def isImplClassName = name endsWith IMPL_CLASS_SUFFIX
     def isLocalDummyName = name startsWith LOCALDUMMY_PREFIX
-    def isLoopHeaderLabel = (name startsWith WHILE_PREFIX) || (name startsWith DO_WHILE_PREFIX)
     def isReplWrapperName = name.toSimpleName containsSlice INTERPRETER_IMPORT_WRAPPER
     def isSetterName = name endsWith SETTER_SUFFIX
-    def isSingletonName = name endsWith SINGLETON_SUFFIX
     def isImportName = name startsWith IMPORT
     def isFieldName = name endsWith LOCAL_SUFFIX
     def isScala2LocalSuffix = name.endsWith(" ")
@@ -110,8 +108,16 @@ object NameOps {
     /** Convert this module class name to corresponding source module name */
     def sourceModuleName: TermName = name.toTermName.exclude(ModuleClassName)
 
-    /** If name ends in module class suffix, drop it */
-    def stripModuleClassSuffix: Name = name.exclude(ModuleClassName)
+    /** If name ends in module class suffix, drop it. This
+     *  method needs to work on mangled as well as unmangled names because
+     *  it is also called from the backend.
+     */
+    def stripModuleClassSuffix: Name = name match {
+      case name: SimpleTermName if name.endsWith("$") =>
+        name.unmangleClassName.exclude(ModuleClassName)
+      case _ =>
+        name.exclude(ModuleClassName)
+    }
 
     /** If flags is a ModuleClass but not a Package, add module class suffix */
     def adjustIfModuleClass(flags: Flags.FlagSet): N = likeTyped {
@@ -122,43 +128,17 @@ object NameOps {
     /** The superaccessor for method with given name */
     def superName: TermName = SuperAccessorName(name.toTermName)
 
-    /** The expanded name of `name` relative to given class `base`.
-     */
-    def expandedName(base: Symbol, separator: Name)(implicit ctx: Context): N =
-      expandedName(if (base.name.is(ExpandedName)) base.name else base.fullNameSeparated("$"), separator)
-
-    def expandedName(base: Symbol)(implicit ctx: Context): N = expandedName(base, nme.EXPAND_SEPARATOR)
-
-    /** The expanded name of `name` relative to `basename` with given `separator`
-     */
-    def expandedName(prefix: Name, separator: Name = nme.EXPAND_SEPARATOR): N =
-      likeTyped {
-        def qualify(name: SimpleTermName) =
-          qualifiedNameKindOfSeparator(separator.toString)(prefix.toTermName, name)
-        name rewrite {
-          case name: SimpleTermName =>
-            qualify(name)
-          case AnyQualifiedName(_, _) =>
-            // Note: an expanded name may itself be expanded. For example, look at javap of scala.App.initCode
-            qualify(name.toSimpleName)
-        }
-      }
-
-    def expandedName(prefix: Name): N = expandedName(prefix, nme.EXPAND_SEPARATOR)
+    def expandedName(base: Symbol, kind: QualifiedNameKind = ExpandedName)(implicit ctx: Context): N = {
+      val prefix =
+        if (base.name.is(ExpandedName)) base.name else base.fullNameSeparated(ExpandPrefixName)
+      likeTyped { kind(prefix.toTermName, name.toTermName) }
+    }
 
     /** Revert the expanded name. */
     def unexpandedName: N = likeTyped {
       name.rewrite { case ExpandedName(_, unexp) => unexp }
     }
 
-    def expandedPrefix: N = likeTyped { name.exclude(ExpandedName) }
-
-    def expandedPrefixOfMangled: N = {
-      val idx = name.lastIndexOfSlice(nme.EXPAND_SEPARATOR)
-      assert(idx >= 0)
-      likeTyped(name.take(idx))
-    }
-
     def implClassName: N = likeTyped(name ++ tpnme.IMPL_CLASS_SUFFIX)
 
     def errorName: N = likeTyped(name ++ nme.ERROR)
diff --git a/compiler/src/dotty/tools/dotc/core/StdNames.scala b/compiler/src/dotty/tools/dotc/core/StdNames.scala
index 7dd569d04..51821c51b 100644
--- a/compiler/src/dotty/tools/dotc/core/StdNames.scala
+++ b/compiler/src/dotty/tools/dotc/core/StdNames.scala
@@ -124,7 +124,6 @@ object StdNames {
     val PACKAGE: N                    = "package"
     val PACKAGE_CLS: N                = "package$"
     val ROOT: N                       = "<root>"
-    val SINGLETON_SUFFIX: N           = ".type"
     val SPECIALIZED_SUFFIX: N         = "$sp"
     val SUPER_PREFIX: N               = "super$"
     val WHILE_PREFIX: N               = "while$"
diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index 3d0b306c0..f4682bf7d 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -383,20 +383,18 @@ object SymDenotations {
     /** The encoded full path name of this denotation, where outer names and inner names
      *  are separated by `separator` strings.
      *  Never translates expansions of operators back to operator symbol.
-     *  Drops package objects. Represents terms in the owner chain by a simple `~`.
+     *  Drops package objects. Represents each term in the owner chain by a simple `~`.
      *  (Note: scalac uses nothing to represent terms, which can cause name clashes
      *   between same-named definitions in different enclosing methods. Before this commit
      *   we used `$' but this can cause ambiguities with the class separator '$').
      *  A separator "" means "flat name"; the real separator in this case is "$" and
      *  enclosing packages do not form part of the name.
      */
-    def fullNameSeparated(separator: String)(implicit ctx: Context): Name = {
-      val stopAtPackage = separator.isEmpty
-      val sep = if (stopAtPackage) "$" else separator
+    def fullNameSeparated(kind: QualifiedNameKind)(implicit ctx: Context): Name =
       if (symbol == NoSymbol ||
           owner == NoSymbol ||
           owner.isEffectiveRoot ||
-          stopAtPackage && owner.is(PackageClass)) name
+          kind == FlatName && owner.is(PackageClass)) name
       else {
         var filler = ""
         var encl = owner
@@ -404,34 +402,25 @@ object SymDenotations {
           encl = encl.owner
           filler += "~"
         }
-        var prefix = encl.fullNameSeparated(separator)
-        val fn =
-          if (qualifiedNameKindOfSeparator.contains(sep)) {
-            if (sep == "$")
-              // duplicate scalac's behavior: don't write a double '$$' for module class members.
-              prefix = prefix.exclude(ModuleClassName)
-            name rewrite {
-              case n: SimpleTermName =>
-                val n1 = if (filler.isEmpty) n else termName(filler ++ n)
-                qualifiedNameKindOfSeparator(sep)(prefix.toTermName, n1)
-            }
-          }
-          else {
-            val sep1 =
-              if (owner.is(ModuleClass, butNot = Package) && sep == "$") ""
-              else sep
-            // duplicate scalac's behavior: don't write a double '$$' for module class members.
-            prefix ++ sep1 ++ name
-          }
+        var prefix = encl.fullNameSeparated(kind)
+        if (kind.separator == "$")
+          // duplicate scalac's behavior: don't write a double '$$' for module class members.
+          prefix = prefix.exclude(ModuleClassName)
+        def qualify(n: SimpleTermName) =
+          kind(prefix.toTermName, if (filler.isEmpty) n else termName(filler ++ n))
+        val fn = name rewrite {
+          case name: SimpleTermName => qualify(name)
+          case name @ AnyQualifiedName(_, _) => qualify(name.toSimpleName)
+        }
         if (isType) fn.toTypeName else fn.toTermName
       }
-    }
+
 
     /** The encoded flat name of this denotation, where joined names are separated by `separator` characters. */
-    def flatName(implicit ctx: Context): Name = fullNameSeparated("")
+    def flatName(implicit ctx: Context): Name = fullNameSeparated(FlatName)
 
     /** `fullName` where `.' is the separator character */
-    def fullName(implicit ctx: Context): Name = fullNameSeparated(".")
+    def fullName(implicit ctx: Context): Name = fullNameSeparated(QualifiedName)
 
     // ----- Tests -------------------------------------------------
 
@@ -1763,13 +1752,13 @@ object SymDenotations {
       }
     }
 
-    private[this] var fullNameCache: SimpleMap[String, Name] = SimpleMap.Empty
-    override final def fullNameSeparated(separator: String)(implicit ctx: Context): Name = {
-      val cached = fullNameCache(separator)
+    private[this] var fullNameCache: SimpleMap[QualifiedNameKind, Name] = SimpleMap.Empty
+    override final def fullNameSeparated(kind: QualifiedNameKind)(implicit ctx: Context): Name = {
+      val cached = fullNameCache(kind)
       if (cached != null) cached
       else {
-        val fn = super.fullNameSeparated(separator)
-        fullNameCache = fullNameCache.updated(separator, fn)
+        val fn = super.fullNameSeparated(kind)
+        fullNameCache = fullNameCache.updated(kind, fn)
         fn
       }
     }
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala b/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
index f7e61c924..ec59e711a 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala
@@ -223,8 +223,9 @@ object TastyFormat {
   final val UTF8 = 1
   final val QUALIFIED = 2
   final val FLATTENED = 3
+  final val EXPANDPREFIX = 5
   final val EXPANDED = 4
-  final val TRAITSETTER = 5
+  final val TRAITSETTER = 6
   final val UNIQUE = 10
   final val DEFAULTGETTER = 11
   final val VARIANT = 12
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala
index a14691ed5..835222727 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala
@@ -49,12 +49,8 @@ class TastyUnpickler(reader: TastyReader) {
       case UTF8 =>
         goto(end)
         termName(bytes, start.index, length)
-      case QUALIFIED =>
-        QualifiedName(readName(), readName().asSimpleName)
-      case FLATTENED =>
-        FlattenedName(readName(), readName().asSimpleName)
-      case EXPANDED =>
-        ExpandedName(readName(), readName().asSimpleName)
+      case QUALIFIED | FLATTENED | EXPANDED | EXPANDPREFIX =>
+        qualifiedNameKindOfTag(tag)(readName(), readName().asSimpleName)
       case UNIQUE =>
         val separator = readName().toString
         val num = readNat()
diff --git a/compiler/src/dotty/tools/dotc/transform/AugmentScala2Traits.scala b/compiler/src/dotty/tools/dotc/transform/AugmentScala2Traits.scala
index a8d82045e..f2ffaff5d 100644
--- a/compiler/src/dotty/tools/dotc/transform/AugmentScala2Traits.scala
+++ b/compiler/src/dotty/tools/dotc/transform/AugmentScala2Traits.scala
@@ -14,7 +14,7 @@ import DenotTransformers._
 import Annotations._
 import StdNames._
 import NameOps._
-import NameKinds._
+import NameKinds.{ExpandedName, TraitSetterName}
 import ast.Trees._
 
 /** This phase augments Scala2 traits with implementation classes and with additional members
@@ -74,7 +74,7 @@ class AugmentScala2Traits extends MiniPhaseTransform with IdentityDenotTransform
       def traitSetter(getter: TermSymbol) =
         getter.copy(
           name = getter.ensureNotPrivate.name
-                  .expandedName(getter.owner, nme.TRAIT_SETTER_SEPARATOR)
+                  .expandedName(getter.owner, TraitSetterName)
                   .asTermName.setterName,
           flags = Method | Accessor,
           info = MethodType(getter.info.resultType :: Nil, defn.UnitType))