Make TypeParamCreation flags depend on owner

Type params should have different flags, depending on whether they are
owned by a method or a class. Only class type parameters are marked Deferred,
protected, and Local.

6 files changed, 13 insertions, 6 deletions

diff --git a/src/dotty/tools/dotc/core/Definitions.scala b/src/dotty/tools/dotc/core/Definitions.scala
index 5e335e240..d04a26883 100644
--- a/src/dotty/tools/dotc/core/Definitions.scala
+++ b/src/dotty/tools/dotc/core/Definitions.scala
@@ -37,7 +37,7 @@ class Definitions {
     scope.enter(newSymbol(cls, name, flags, TypeBounds.empty))
 
   private def newTypeParam(cls: ClassSymbol, name: TypeName, flags: FlagSet, scope: MutableScope) =
-    newTypeField(cls, name, flags | TypeParamCreationFlags, scope)
+    newTypeField(cls, name, flags | ClassTypeParamCreationFlags, scope)
 
   private def newSyntheticTypeParam(cls: ClassSymbol, scope: MutableScope, paramFlags: FlagSet, suffix: String = "T0") =
     newTypeParam(cls, suffix.toTypeName.expandedName(cls), ExpandedName | paramFlags, scope)
diff --git a/src/dotty/tools/dotc/core/Flags.scala b/src/dotty/tools/dotc/core/Flags.scala
index b68e7dc42..c467a553f 100644
--- a/src/dotty/tools/dotc/core/Flags.scala
+++ b/src/dotty/tools/dotc/core/Flags.scala
@@ -452,8 +452,8 @@ object Flags {
   /** The flags of the self symbol */
   final val SelfSymFlags = Private | Local | Deferred
 
-  /** The flags of a type parameter */
-  final val TypeParamCreationFlags = TypeParam | Deferred | Protected | Local
+  /** The flags of a class type parameter */
+  final def ClassTypeParamCreationFlags = TypeParam | Deferred | Protected | Local
 
   /** Flags that can apply to both a module val and a module class, except those that
     *  are added at creation anyway
diff --git a/src/dotty/tools/dotc/core/SymDenotations.scala b/src/dotty/tools/dotc/core/SymDenotations.scala
index f55817505..7d1948784 100644
--- a/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -828,6 +828,11 @@ object SymDenotations {
       else if (this is Contravariant) -1
       else 0
 
+    /** The flags to be used for a type parameter owned by this symbol.
+     *  Overridden by ClassDenotation.
+     */
+    def typeParamCreationFlags: FlagSet = TypeParam
+
     override def toString = {
       val kindString =
         if (myFlags is ModuleClass) "module class"
@@ -1080,6 +1085,8 @@ object SymDenotations {
           (symbol eq defn.NothingClass) ||
             (symbol eq defn.NullClass) && (base ne defn.NothingClass))
 
+    final override def typeParamCreationFlags = ClassTypeParamCreationFlags
+
     private[this] var myMemberFingerPrint: FingerPrint = FingerPrint.unknown
 
     private def computeMemberFingerPrint(implicit ctx: Context): FingerPrint = {
diff --git a/src/dotty/tools/dotc/core/Symbols.scala b/src/dotty/tools/dotc/core/Symbols.scala
index 9d60c9985..ab083a128 100644
--- a/src/dotty/tools/dotc/core/Symbols.scala
+++ b/src/dotty/tools/dotc/core/Symbols.scala
@@ -251,7 +251,7 @@ trait Symbols { this: Context =>
     val tparams = tparamBuf.toList
     val bounds = boundsFn(trefBuf.toList)
     for ((name, tparam, bound) <- (names, tparams, bounds).zipped)
-      tparam.denot = SymDenotation(tparam, owner, name, flags | TypeParamCreationFlags, bound)
+      tparam.denot = SymDenotation(tparam, owner, name, flags | owner.typeParamCreationFlags, bound)
     tparams
   }
 
diff --git a/src/dotty/tools/dotc/core/pickling/ClassfileParser.scala b/src/dotty/tools/dotc/core/pickling/ClassfileParser.scala
index f2b81072a..59658c9c1 100644
--- a/src/dotty/tools/dotc/core/pickling/ClassfileParser.scala
+++ b/src/dotty/tools/dotc/core/pickling/ClassfileParser.scala
@@ -353,7 +353,7 @@ class ClassfileParser(
         val tpname = subName(':'.==).toTypeName
         val expname = if (owner.isClass) tpname.expandedName(owner) else tpname
         val s = ctx.newSymbol(
-          owner, expname, Flags.TypeParamCreationFlags,
+          owner, expname, owner.typeParamCreationFlags,
           typeParamCompleter(index), coord = indexCoord(index))
         if (owner.isClass) owner.asClass.enter(s, owner.decls)
         tparams = tparams + (tpname -> s)
diff --git a/src/dotty/tools/dotc/core/pickling/UnPickler.scala b/src/dotty/tools/dotc/core/pickling/UnPickler.scala
index 5b41d1382..36b2c99bf 100644
--- a/src/dotty/tools/dotc/core/pickling/UnPickler.scala
+++ b/src/dotty/tools/dotc/core/pickling/UnPickler.scala
@@ -453,7 +453,7 @@ class UnPickler(bytes: Array[Byte], classRoot: ClassDenotation, moduleClassRoot:
         var flags1 = flags
         if (flags is TypeParam) {
           name1 = name1.expandedName(owner)
-          flags1 |= TypeParamCreationFlags | ExpandedName
+          flags1 |= owner.typeParamCreationFlags | ExpandedName
         }
         ctx.newSymbol(owner, name1, flags1, localMemberUnpickler, coord = start)
       case CLASSsym =>