remove JavaEnumValue from AfterLoadFlags

Author: noti0na1

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -450,12 +450,7 @@ object Flags {
    *  is completed)
    */
   val AfterLoadFlags: FlagSet = commonFlags(
-    FromStartFlags, AccessFlags, Final, AccessorOrSealed, LazyOrTrait, SelfName, JavaDefined,
-    // We would like to add JavaEnumValue to this set so that we can correctly
-    // detect it in JavaNullInterop. However, JavaEnumValue is not initialized at this
-    // point, so we just make sure that all the "primitive" flags contained in JavaEnumValue
-    // are mentioned here as well.
-    Enum, StableRealizable)
+    FromStartFlags, AccessFlags, Final, AccessorOrSealed, LazyOrTrait, SelfName, JavaDefined)
 
   /** A value that's unstable unless complemented with a Stable flag */
   val UnstableValueFlags: FlagSet = Mutable | Method

compiler/src/dotty/tools/dotc/core/JavaNullInterop.scala

@@ -52,12 +52,12 @@ object JavaNullInterop {
    *
    *  But the selection can throw an NPE if the returned value is `null`.
    */
-  def nullifyMember(sym: Symbol, tp: Type)(implicit ctx: Context): Type = {
+  def nullifyMember(sym: Symbol, tp: Type, isEnum: Boolean)(implicit ctx: Context): Type = {
     assert(ctx.explicitNulls)
     assert(sym.is(JavaDefined), "can only nullify java-defined members")
 
     // Some special cases when nullifying the type
-    if (sym.name == nme.TYPE_ || sym.isAllOf(Flags.JavaEnumValue))
+    if (isEnum || sym.name == nme.TYPE_)
       // Don't nullify the `TYPE` field in every class and Java enum instances
       tp
     else if (sym.name == nme.toString_ || sym.isConstructor || hasNotNullAnnot(sym))

compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

@@ -287,7 +287,7 @@ class ClassfileParser(
         if (denot.is(Flags.Method) && (jflags & JAVA_ACC_VARARGS) != 0)
           denot.info = arrayToRepeated(denot.info)
 
-        if (ctx.explicitNulls) denot.info = JavaNullInterop.nullifyMember(denot.symbol, denot.info)
+        if (ctx.explicitNulls) denot.info = JavaNullInterop.nullifyMember(denot.symbol, denot.info, isEnum)
 
         // seal java enums
         if (isEnum) {

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

@@ -1421,7 +1421,7 @@ class Namer { typer: Typer =>
     }
     val memTpe = paramFn(checkSimpleKinded(typedAheadType(mdef.tpt, tptProto)).tpe)
     if (ctx.explicitNulls && mdef.mods.is(JavaDefined))
-      JavaNullInterop.nullifyMember(sym, memTpe)
+      JavaNullInterop.nullifyMember(sym, memTpe, mdef.mods.isAllOf(JavaEnumValue))
     else memTpe
   }
 

tests/explicit-nulls/pos-separate/interop-enum-src/Day_1.java

@@ -0,0 +1,6 @@
+
+public enum Day_1 {
+	SUN,
+	MON,
+	TUE
+}

tests/explicit-nulls/pos-separate/interop-enum-src/Planet_2.java

@@ -0,0 +1,19 @@
+public enum Planet_2 {
+    MERCURY (3.303e+23, 2.4397e6),
+    VENUS   (4.869e+24, 6.0518e6),
+    EARTH   (5.976e+24, 6.37814e6),
+    MARS    (6.421e+23, 3.3972e6),
+    JUPITER (1.9e+27,   7.1492e7),
+    SATURN  (5.688e+26, 6.0268e7),
+    URANUS  (8.686e+25, 2.5559e7),
+    NEPTUNE (1.024e+26, 2.4746e7);
+
+    private final double mass;   // in kilograms
+    private final double radius; // in meters
+    Planet_2(double mass, double radius) {
+        this.mass = mass;
+        this.radius = radius;
+    }
+    private double mass() { return mass; }
+    private double radius() { return radius; }
+}

tests/explicit-nulls/pos-separate/interop-enum-src/S_3.scala

@@ -0,0 +1,6 @@
+
+// Verify that enum values aren't nullified.
+class S {
+  val d: Day_1 = Day_1.MON
+  val p: Planet_2 = Planet_2.MARS
+}

tests/explicit-nulls/pos/widen-nullable-union.scala

@@ -33,4 +33,10 @@ class Test {
     val y = x
     val _: AnyRef | Null = y
   }
+
+  locally {
+    val x: (A | Null) & (Null | B) = ???
+    val y = x
+    val _: (A & B) | Null = y
+  }
 }