Fix ParamForwarder under non-separate compilation

compiler/src/dotty/tools/dotc/transform/ParamForwarding.scala

@@ -48,7 +48,7 @@ class ParamForwarding(thisTransformer: DenotTransformer) {
         val candidate = sym.owner.asClass.superClass
           .info.decl(sym.name).suchThat(_ is (ParamAccessor, butNot = Mutable)).symbol
         if (candidate.isAccessibleFrom(currentClass.thisType, superAccess = true)) candidate
-        else if (candidate is Method) inheritedAccessor(candidate)
+        else if (candidate.exists) inheritedAccessor(candidate)
         else NoSymbol
       }
       def forwardParamAccessor(stat: Tree): Tree = {

tests/run/paramForwarding.check

@@ -13,4 +13,4 @@ NonVal:
 X:
 private final int X.theValue$$local
 Y:
-private final int Y.theValue$$local
+

tests/run/paramForwarding.scala

@@ -36,8 +36,8 @@ class NonVal(theValue: Int) extends A(theValue) {
 // X.theValue() which overrides A.theValue()
 class X(override val theValue: Int) extends NonVal(0)
 
-// Y contains a field Y.theValue$$local accessible using the getter
-// Y.theValue() which overrides A.theValue()
+// Y does not contains a field Y.theValue$$local, it contains
+// a getter Y.theValue() which only calls super.theValue()
 class Y(override val theValue: Int) extends NonVal(theValue)
 
 

tests/run/paramForwarding_separate/A_1.scala

@@ -1,3 +1,8 @@
-class A(val member: Int)
+class A(val member: Int) {
+  def getAMember = member
+}
+
+class SubA(member: Int) extends A(member) {
+  def getSubAMember = member
+}
 
-class SubA(member: Int) extends A(member)

tests/run/paramForwarding_separate/B_2.scala

@@ -1,4 +1,6 @@
-class B(member: Int) extends SubA(member)
+class B(member: Int) extends SubA(member) {
+  def getMember = member
+}
 
 object Test {
   def printFields(cls: Class[_]) =

tests/run/paramForwarding_together.check

@@ -0,0 +1,6 @@
+# Fields in A:
+private final int A.member$$local
+# Fields in SubA:
+
+# Fields in B:
+

tests/run/paramForwarding_together.scala

@@ -0,0 +1,29 @@
+class A(val member: Int) {
+  def getAMember = member
+}
+
+class SubA(member: Int) extends A(member) {
+  def getSubAMember = member
+}
+
+class B(member: Int) extends SubA(member) {
+  def getBMember = member
+}
+
+object Test {
+  def printFields(cls: Class[_]) =
+    println(cls.getDeclaredFields.map(_.toString).sorted.deep.mkString("\n"))
+
+  def main(args: Array[String]): Unit = {
+    val a = new A(10)
+    val subA = new SubA(11)
+    val b = new B(12)
+
+    println("# Fields in A:")
+    printFields(classOf[A])
+    println("# Fields in SubA:")
+    printFields(classOf[SubA])
+    println("# Fields in B:")
+    printFields(classOf[B])
+  }
+}

tests/run/paramForwarding_together_b.check

@@ -0,0 +1,6 @@
+# Fields in A:
+private final int A.member$$local
+# Fields in SubA:
+
+# Fields in B:
+

tests/run/paramForwarding_together_b.scala

@@ -0,0 +1,30 @@
+class B(member: Int) extends SubA(member) {
+  def getBMember = member
+}
+
+class SubA(member: Int) extends A(member) {
+  def getSubAMember = member
+}
+
+class A(val member: Int) {
+  def getAMember = member
+}
+
+
+object Test {
+  def printFields(cls: Class[_]) =
+    println(cls.getDeclaredFields.map(_.toString).sorted.deep.mkString("\n"))
+
+  def main(args: Array[String]): Unit = {
+    val a = new A(10)
+    val subA = new SubA(11)
+    val b = new B(12)
+
+    println("# Fields in A:")
+    printFields(classOf[A])
+    println("# Fields in SubA:")
+    printFields(classOf[SubA])
+    println("# Fields in B:")
+    printFields(classOf[B])
+  }
+}