Move hashCode and ## to Scrutable

Author: odersky

compiler/src/dotty/tools/backend/jvm/scalaPrimitives.scala

@@ -151,7 +151,7 @@ class DottyPrimitives(ictx: Context) {
     addPrimitive(defn.Any_!=, NE)
     addPrimitive(defn.Scrutable_isInstanceOf, IS)
     addPrimitive(defn.Any_asInstanceOf, AS)
-    addPrimitive(defn.Any_##, HASH)
+    addPrimitive(defn.Scrutable_##, HASH)
 
     // java.lang.Object
     addPrimitive(defn.Object_eq, ID)

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

@@ -284,14 +284,14 @@ class Definitions {
     @tu lazy val Any_== : TermSymbol          = enterMethod(AnyClass, nme.EQ, methOfAny(BooleanType), Final)
     @tu lazy val Any_!= : TermSymbol          = enterMethod(AnyClass, nme.NE, methOfAny(BooleanType), Final)
     @tu lazy val Any_equals: TermSymbol       = enterMethod(AnyClass, nme.equals_, methOfAny(BooleanType))
-    @tu lazy val Any_hashCode: TermSymbol     = enterMethod(AnyClass, nme.hashCode_, MethodType(Nil, IntType))
     @tu lazy val Any_toString: TermSymbol     = enterMethod(AnyClass, nme.toString_, MethodType(Nil, StringType))
-    @tu lazy val Any_## : TermSymbol          = enterMethod(AnyClass, nme.HASHHASH, ExprType(IntType), Final)
     @tu lazy val Any_asInstanceOf: TermSymbol = enterT1ParameterlessMethod(AnyClass, nme.asInstanceOf_, _.paramRefs(0), Final)
     @tu lazy val Any_typeTest: TermSymbol     = enterT1ParameterlessMethod(AnyClass, nme.isInstanceOfPM, _ => BooleanType, Final | Synthetic | Artifact)
     @tu lazy val Any_typeCast: TermSymbol     = enterT1ParameterlessMethod(AnyClass, nme.asInstanceOfPM, _.paramRefs(0), Final | Synthetic | Artifact | StableRealizable)
       // generated by pattern matcher and explicit nulls, eliminated by erasure
 
+    @tu lazy val Scrutable_hashCode: TermSymbol     = enterMethod(ScrutableClass, nme.hashCode_, MethodType(Nil, IntType))
+    @tu lazy val Scrutable_## : TermSymbol          = enterMethod(ScrutableClass, nme.HASHHASH, ExprType(IntType), Final)
     @tu lazy val Scrutable_isInstanceOf: TermSymbol = enterT1ParameterlessMethod(ScrutableClass, nme.isInstanceOf_, _ => BooleanType, Final)
 
     /** def getClass[A >: this.type](): Class[? <: A] */
@@ -302,10 +302,11 @@ class Definitions {
           Final,
           bounds = TypeBounds.lower(ScrutableClass.thisType))
 
-    def AnyMethods: List[TermSymbol] = List(Any_==, Any_!=, Any_equals, Any_hashCode,
-      Any_toString, Any_##, Scrutable_isInstanceOf, Any_asInstanceOf, Any_typeTest, Any_typeCast)
+    def AnyMethods: List[TermSymbol] =
+      List(Any_==, Any_!=, Any_equals, Any_toString, Any_asInstanceOf, Any_typeTest, Any_typeCast)
 
-    def ScrutableMethods: List[TermSymbol] = List(Scrutable_getClass, Scrutable_isInstanceOf)
+    def ScrutableMethods: List[TermSymbol] =
+      List(Scrutable_getClass, Scrutable_isInstanceOf, Scrutable_hashCode, Scrutable_##)
 
     @tu lazy val ScrutableMethodNames = ScrutableMethods.map(_.name)
 
@@ -442,8 +443,8 @@ class Definitions {
         Object_finalize, Object_notify, Object_notifyAll, Object_wait, Object_waitL, Object_waitLI)
 
   /** Methods in Object, Scrutable, and Any that do not have a side effect */
-  @tu lazy val pureMethods: List[TermSymbol] = List(Any_==, Any_!=, Any_equals, Any_hashCode,
-    Any_toString, Any_##, Scrutable_getClass, Scrutable_isInstanceOf, Any_typeTest, Object_eq, Object_ne)
+  @tu lazy val pureMethods: List[TermSymbol] = List(Any_==, Any_!=, Any_equals, Scrutable_hashCode,
+    Any_toString, Scrutable_##, Scrutable_getClass, Scrutable_isInstanceOf, Any_typeTest, Object_eq, Object_ne)
 
   @tu lazy val AnyKindClass: ClassSymbol = {
     val cls = newCompleteClassSymbol(ScalaPackageClass, tpnme.AnyKind, AbstractFinal | Permanent, Nil)

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

@@ -35,7 +35,7 @@ class InterceptedMethods extends MiniPhase {
     transformRefTree(tree)
 
   private def transformRefTree(tree: RefTree)(using Context): Tree =
-    if (tree.symbol.isTerm && (defn.Any_## eq tree.symbol)) {
+    if (tree.symbol.isTerm && (defn.Scrutable_## eq tree.symbol)) {
       val qual = tree match {
         case id: Ident => tpd.desugarIdentPrefix(id)
         case sel: Select => sel.qualifier

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

@@ -174,7 +174,7 @@ class SuperAccessors(thisPhase: DenotTransformer) {
     sym.isTypeTestOrCast ||
     (sym eq defn.Any_==) ||
     (sym eq defn.Any_!=) ||
-    (sym eq defn.Any_##)
+    (sym eq defn.Scrutable_##)
 
   /** Transform select node, adding super and protected accessors as needed */
   def transformSelect(tree: Tree, targs: List[Tree])(using Context): Tree = {

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

@@ -62,7 +62,7 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
 
   private def initSymbols(using Context) =
     if (myValueSymbols.isEmpty) {
-      myValueSymbols = List(defn.Any_hashCode, defn.Any_equals)
+      myValueSymbols = List(defn.Scrutable_hashCode, defn.Any_equals)
       myCaseSymbols = myValueSymbols ++ List(defn.Any_toString, defn.Product_canEqual,
         defn.Product_productArity, defn.Product_productPrefix, defn.Product_productElement,
         defn.Product_productElementName)
@@ -285,7 +285,10 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
      */
     def valueHashCodeBody(using Context): Tree = {
       assert(accessors.nonEmpty)
-      ref(accessors.head).select(nme.hashCode_).ensureApplied
+      ref(accessors.head)
+        .ensureConforms(defn.ScrutableType)
+        .select(nme.hashCode_)
+        .ensureApplied
     }
 
     /** The class
@@ -344,7 +347,12 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
       val acc = newSymbol(ctx.owner, nme.acc, Mutable | Synthetic, defn.IntType, coord = ctx.owner.span)
       val accDef = ValDef(acc, Literal(Constant(0xcafebabe)))
       val mixPrefix = Assign(ref(acc),
-        ref(defn.staticsMethod("mix")).appliedTo(ref(acc), This(clazz).select(defn.Product_productPrefix).select(defn.Any_hashCode).appliedToNone))
+        ref(defn.staticsMethod("mix")).appliedTo(
+          ref(acc),
+          This(clazz)
+            .select(defn.Product_productPrefix)
+            .select(defn.Scrutable_hashCode)
+            .appliedToNone))
       val mixes = for (accessor <- accessors) yield
         Assign(ref(acc), ref(defn.staticsMethod("mix")).appliedTo(ref(acc), hashImpl(accessor)))
       val finish = ref(defn.staticsMethod("finalizeHash")).appliedTo(ref(acc), Literal(Constant(accessors.size)))

compiler/src/dotty/tools/dotc/transform/sjs/PrepJSInterop.scala

@@ -604,7 +604,7 @@ class PrepJSInterop extends MacroTransform with IdentityDenotTransformer { thisP
               "  if you want to define a method named \"equals\" in JavaScript, use a different name and add @JSName(\"equals\").",
               sym)
 
-        case nme.hashCode_ if sym.info.matches(defn.Any_hashCode.info) =>
+        case nme.hashCode_ if sym.info.matches(defn.Scrutable_hashCode.info) =>
           report.error(
               "error overriding method hashCode(): Int in a JS class;\n" +
               "  method hashCode(): Int is considered final in trait js.Any;\n" +

tests/run/t6534.scala

@@ -1,5 +1,5 @@
-trait Foo extends Any { override def equals(x: Any) = false }
-trait Ding extends Any { override def hashCode = -1 }
+trait Foo extends Scrutable { override def equals(x: Any) = false }
+trait Ding extends Scrutable { override def hashCode = -1 }
 
 class Bippy1(val x: Int) extends AnyVal with Foo { }  // warn
 class Bippy2(val x: Int) extends AnyVal with Ding { } // warn