Merge pull request #11098 from dotty-staging/fix-#11081

Tighten condition when to check enum constructors

Author: odersky

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -1180,7 +1180,7 @@ trait Checking {
    */
   def checkEnumCaseRefsLegal(cdef: TypeDef, enumCtx: Context)(using Context): Unit = {
 
-    def checkCaseOrDefault(stat: Tree, caseCtx: Context) = {
+    def checkEnumCaseOrDefault(stat: Tree, caseCtx: Context) = {
 
       def check(tree: Tree) = {
         // allow access to `sym` if a typedIdent just outside the enclosing enum
@@ -1193,7 +1193,7 @@ trait Checking {
         checkRefsLegal(tree, cdef.symbol, allowAccess, "enum case")
       }
 
-      if (stat.symbol.is(Case))
+      if (stat.symbol.isAllOf(EnumCase))
         stat match {
           case TypeDef(_, Template(DefDef(_, paramss, _, _), parents, _, _)) =>
             paramss.foreach(_.foreach(check))
@@ -1207,7 +1207,7 @@ trait Checking {
             }
           case _ =>
         }
-      else if (stat.symbol.is(Module) && stat.symbol.linkedClass.is(Case))
+      else if (stat.symbol.is(Module) && stat.symbol.linkedClass.isAllOf(EnumCase))
         stat match {
           case TypeDef(_, impl: Template) =>
             for ((defaultGetter @
@@ -1219,16 +1219,16 @@ trait Checking {
 
     cdef.rhs match {
       case impl: Template =>
-        def isCase(stat: Tree) = stat match {
-          case _: ValDef | _: TypeDef => stat.symbol.is(Case)
+        def isEnumCase(stat: Tree) = stat match {
+          case _: ValDef | _: TypeDef => stat.symbol.isAllOf(EnumCase)
           case _ => false
         }
         val cases =
-          for (stat <- impl.body if isCase(stat))
+          for (stat <- impl.body if isEnumCase(stat))
           yield untpd.ImportSelector(untpd.Ident(stat.symbol.name.toTermName))
         val caseImport: Import = Import(ref(cdef.symbol), cases)
         val caseCtx = enumCtx.importContext(caseImport, caseImport.symbol)
-        for (stat <- impl.body) checkCaseOrDefault(stat, caseCtx)
+        for (stat <- impl.body) checkEnumCaseOrDefault(stat, caseCtx)
       case _ =>
     }
   }

tests/neg/i11081.scala

@@ -0,0 +1,6 @@
+enum Outer:
+  case Foo(u: Unavailable) // error
+  case Bar(u: DefinitelyNotAvailable) // error
+object Outer:
+  class Unavailable(i: Int)
+  case class DefinitelyNotAvailable()

tests/pos/i11081.scala

@@ -0,0 +1,6 @@
+enum Outer:
+  case Foo
+object Outer:
+  trait Bar
+  case class Baz(bar: Bar)
+  case class Bam(bar: Bar = new Bar() {})