From 366f06a27a4604f4bd279a444d3fc7cbc3979ac6 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Thu, 23 Nov 2023 12:38:47 +0100
Subject: [PATCH 1/3] Refactor some tuple methods

 - Move from Definitions to TypeUtils
 - Unify TypeUtils.tupleElementTypes and Definitions.tupleTypes. They do
   the same thing.

I'd like to move more things out of Definitions and into TypeUtils and SymUtils.
Then I'd like to move these files to the core package, and make their operations
accessible automatically by having the companion objects of Types and Symbols inherit
from them. This is a first step into that direction.
---
 .../dotty/tools/dotc/core/Definitions.scala   | 20 -------
 .../tools/dotc/printing/RefinedPrinter.scala  |  2 +-
 .../dotc/transform/TupleOptimizations.scala   | 12 ++--
 .../tools/dotc/transform/TypeUtils.scala      | 55 +++++++++++++------
 .../dotty/tools/dotc/typer/Synthesizer.scala  |  2 +-
 .../src/dotty/tools/dotc/typer/Typer.scala    |  6 +-
 6 files changed, 50 insertions(+), 47 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/core/Definitions.scala b/compiler/src/dotty/tools/dotc/core/Definitions.scala
index 1a99c19baaf4..9c1f45e7818b 100644
--- a/compiler/src/dotty/tools/dotc/core/Definitions.scala
+++ b/compiler/src/dotty/tools/dotc/core/Definitions.scala
@@ -1749,26 +1749,6 @@ class Definitions {
     else TypeOps.nestedPairs(elems)
   }
 
-  def tupleTypes(tp: Type, bound: Int = Int.MaxValue)(using Context): Option[List[Type]] = {
-    @tailrec def rec(tp: Type, acc: List[Type], bound: Int): Option[List[Type]] = tp.normalized.dealias match {
-      case _ if bound < 0 => Some(acc.reverse)
-      case tp: AppliedType if PairClass == tp.classSymbol => rec(tp.args(1), tp.args.head :: acc, bound - 1)
-      case tp: AppliedType if isTupleNType(tp) => Some(acc.reverse ::: tp.args)
-      case tp: TermRef if tp.symbol == defn.EmptyTupleModule => Some(acc.reverse)
-      case _ => None
-    }
-    rec(tp.stripTypeVar, Nil, bound)
-  }
-
-  def isSmallGenericTuple(tp: Type)(using Context): Boolean =
-    if tp.derivesFrom(defn.PairClass) && !defn.isTupleNType(tp.widenDealias) then
-      // If this is a generic tuple we need to cast it to make the TupleN/ members accessible.
-      // This works only for generic tuples of known size up to 22.
-      defn.tupleTypes(tp.widenTermRefExpr) match
-        case Some(elems) if elems.length <= Definitions.MaxTupleArity => true
-        case _ => false
-    else false
-
   def isProductSubType(tp: Type)(using Context): Boolean = tp.derivesFrom(ProductClass)
 
   /** Is `tp` (an alias) of either a scala.FunctionN or a scala.ContextFunctionN
diff --git a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
index 73c83f847061..6c61740e5b63 100644
--- a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
+++ b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
@@ -235,7 +235,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
 
     def appliedText(tp: Type): Text = tp match
       case tp @ AppliedType(tycon, args) =>
-        tp.tupleElementTypes match
+        tp.tupleElementTypesUpTo(200, normalize = false) match
           case Some(types) if types.size >= 2 && !printDebug => toTextTuple(types)
           case _ =>
             val tsym = tycon.typeSymbol
diff --git a/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala b/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
index fee7bb19e0be..5cdb13429a32 100644
--- a/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
@@ -10,9 +10,9 @@ import StdNames.*
 import Symbols.*
 import MegaPhase.*
 import Types.*
+import transform.TypeUtils.*
 import dotty.tools.dotc.ast.tpd
 
-
 /** Optimize generic operations on tuples */
 class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
   import tpd.*
@@ -33,7 +33,7 @@ class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
 
   private def transformTupleCons(tree: tpd.Apply)(using Context): Tree = {
     val head :: tail :: Nil = tree.args: @unchecked
-    defn.tupleTypes(tree.tpe.widenTermRefExpr.dealias) match {
+    tree.tpe.widenTermRefExpr.tupleElementTypes match {
       case Some(tpes) =>
         // Generate a the tuple directly with TupleN+1.apply
         val size = tpes.size
@@ -61,7 +61,7 @@ class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
 
   private def transformTupleTail(tree: tpd.Apply)(using Context): Tree = {
     val Apply(_, tup :: Nil) = tree: @unchecked
-    defn.tupleTypes(tup.tpe.widenTermRefExpr.dealias, MaxTupleArity + 1) match {
+    tup.tpe.widenTermRefExpr.tupleElementTypesUpTo(MaxTupleArity + 1) match {
       case Some(tpes) =>
         // Generate a the tuple directly with TupleN-1.apply
         val size = tpes.size
@@ -104,7 +104,7 @@ class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
 
   private def transformTupleConcat(tree: tpd.Apply)(using Context): Tree = {
     val Apply(_, self :: that :: Nil) = tree: @unchecked
-    (defn.tupleTypes(self.tpe.widenTermRefExpr.dealias), defn.tupleTypes(that.tpe.widenTermRefExpr.dealias)) match {
+    (self.tpe.widenTermRefExpr.tupleElementTypes, that.tpe.widenTermRefExpr.tupleElementTypes) match {
       case (Some(tpes1), Some(tpes2)) =>
         // Generate a the tuple directly with TupleN+M.apply
         val n = tpes1.size
@@ -139,7 +139,7 @@ class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
 
   private def transformTupleApply(tree: tpd.Apply)(using Context): Tree = {
     val Apply(_, tup :: nTree :: Nil) = tree: @unchecked
-    (defn.tupleTypes(tup.tpe.widenTermRefExpr.dealias), nTree.tpe) match {
+    (tup.tpe.widenTermRefExpr.tupleElementTypes, nTree.tpe) match {
       case (Some(tpes), nTpe: ConstantType) =>
         // Get the element directly with TupleM._n+1 or TupleXXL.productElement(n)
         val size = tpes.size
@@ -166,7 +166,7 @@ class TupleOptimizations extends MiniPhase with IdentityDenotTransformer {
 
   private def transformTupleToArray(tree: tpd.Apply)(using Context): Tree = {
     val Apply(_, tup :: Nil) = tree: @unchecked
-    defn.tupleTypes(tup.tpe.widen, MaxTupleArity) match {
+    tup.tpe.widen.tupleElementTypesUpTo(MaxTupleArity) match {
       case Some(tpes) =>
         val size = tpes.size
         if (size == 0)
diff --git a/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala b/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala
index 90f6e2795f12..99c8e2fc7518 100644
--- a/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala
@@ -45,22 +45,45 @@ object TypeUtils {
       case ps => ps.reduceLeft(AndType(_, _))
     }
 
-    /** The element types of this tuple type, which can be made up of EmptyTuple, TupleX and `*:` pairs */
-    def tupleElementTypes(using Context): Option[List[Type]] = self.dealias match {
-      case AppliedType(tycon, hd :: tl :: Nil) if tycon.isRef(defn.PairClass) =>
-        tl.tupleElementTypes.map(hd :: _)
-      case self: SingletonType =>
-        if self.termSymbol == defn.EmptyTupleModule then Some(Nil) else None
-      case AndType(tp1, tp2) =>
-        // We assume that we have the following property:
-        // (T1, T2, ..., Tn) & (U1, U2, ..., Un) = (T1 & U1, T2 & U2, ..., Tn & Un)
-        tp1.tupleElementTypes.zip(tp2.tupleElementTypes).map { case (t1, t2) => t1.intersect(t2) }
-      case OrType(tp1, tp2) =>
-        None // We can't combine the type of two tuples
-      case _ =>
-        if defn.isTupleClass(self.typeSymbol) then Some(self.dealias.argInfos)
-        else None
-    }
+    /** The element types of this tuple type, which can be made up of EmptyTuple, TupleX and `*:` pairs
+     */
+    def tupleElementTypes(using Context): Option[List[Type]] =
+      tupleElementTypesUpTo(Int.MaxValue)
+
+    /** The element types of this tuple type, which can be made up of EmptyTuple, TupleX and `*:` pairs
+     *  @param bound     The maximum number of elements that needs generating minus 1
+     *                   The generation will stop once more than bound elems have been generated
+     *  @param normalize If true, normalize and dealias at each step.
+     *                   If false, never normalize and dealias only to find *:
+     *                   and EmptyTuple types. This is useful for printing.
+     */
+    def tupleElementTypesUpTo(bound: Int, normalize: Boolean = true)(using Context): Option[List[Type]] =
+      def recur(tp: Type, bound: Int): Option[List[Type]] =
+        if bound < 0 then Some(Nil)
+        else (if normalize then tp.normalized else tp).dealias match
+          case AppliedType(tycon, hd :: tl :: Nil) if tycon.isRef(defn.PairClass) =>
+            recur(tl, bound - 1).map(hd :: _)
+          case tp: AppliedType if defn.isTupleNType(tp) && normalize =>
+            Some(tp.args)  // if normalize is set, use the dealiased tuple
+                           // otherwise rely on the default case below to print unaliased tuples.
+          case tp: SingletonType =>
+            if tp.termSymbol == defn.EmptyTupleModule then Some(Nil) else None
+          case _ =>
+            if defn.isTupleClass(tp.typeSymbol) && !normalize then Some(tp.dealias.argInfos)
+            else None
+      recur(self.stripTypeVar, bound)
+
+    /** Is this a generic tuple that would fit into the range 1..22,
+     *  but is not already an instance of one of Tuple1..22?
+     *  In this case we need to cast it to make the TupleN/ members accessible.
+     *  This works only for generic tuples of known size up to 22.
+     */
+    def isSmallGenericTuple(using Context): Boolean =
+      self.derivesFrom(defn.PairClass)
+      && !defn.isTupleNType(self.widenDealias)
+      && self.widenTermRefExpr.tupleElementTypesUpTo(Definitions.MaxTupleArity).match
+          case Some(elems) if elems.length <= Definitions.MaxTupleArity => true
+          case _ => false
 
     /** The `*:` equivalent of an instance of a Tuple class */
     def toNestedPairs(using Context): Type =
diff --git a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
index 7c008870760d..d322176fa56d 100644
--- a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
@@ -119,7 +119,7 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
             // TupledFunction[?, (...) => R]
             tupled.functionArgInfos match
               case tupledArgs :: funRet :: Nil =>
-                defn.tupleTypes(tupledArgs.dealias) match
+                tupledArgs.tupleElementTypes match
                   case Some(funArgs) if functionTypeEqual(tupled, funArgs, funRet, fun) =>
                     // TupledFunction[?, ((...funArgs...)) => funRet]
                     funArgs.size
diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala
index 3d61ac0a51f3..6647b1050670 100644
--- a/compiler/src/dotty/tools/dotc/typer/Typer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala
@@ -707,8 +707,8 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
        // There's a second trial where we try to instantiate all type variables in `qual.tpe.widen`,
        // but that is done only after we search for extension methods or conversions.
       typedSelect(tree, pt, qual)
-    else if defn.isSmallGenericTuple(qual.tpe) then
-      val elems = defn.tupleTypes(qual.tpe.widenTermRefExpr).getOrElse(Nil)
+    else if qual.tpe.isSmallGenericTuple then
+      val elems = qual.tpe.widenTermRefExpr.tupleElementTypes.getOrElse(Nil)
       typedSelect(tree, pt, qual.cast(defn.tupleType(elems)))
     else
       val tree1 = tryExtensionOrConversion(
@@ -729,7 +729,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
             if checkedType1.exists then
               gadts.println(i"Member selection healed by GADT approximation")
               finish(tree1, qual1, checkedType1)
-            else if defn.isSmallGenericTuple(qual1.tpe) then
+            else if qual1.tpe.isSmallGenericTuple then
               gadts.println(i"Tuple member selection healed by GADT approximation")
               typedSelect(tree, pt, qual1)
             else

From 6793291700e141cb153f25b410d03393bf590747 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Thu, 23 Nov 2023 15:12:58 +0100
Subject: [PATCH 2/3] Refactor TypeUtils

 = Move to core package. It was for historical reasons in transform because
   it was originally intended as a collection of type operations that were
   were useful in transform phases. But it's now used from everywhere.
 - Make a base class of Types, so that it does not need to be imported explicitly.
---
 compiler/src/dotty/tools/dotc/ast/tpd.scala                  | 1 -
 compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala  | 1 -
 compiler/src/dotty/tools/dotc/core/SymDenotations.scala      | 1 -
 compiler/src/dotty/tools/dotc/core/TypeApplications.scala    | 1 -
 compiler/src/dotty/tools/dotc/core/TypeComparer.scala        | 1 -
 compiler/src/dotty/tools/dotc/core/TypeErasure.scala         | 2 --
 .../src/dotty/tools/dotc/{transform => core}/TypeUtils.scala | 5 ++---
 compiler/src/dotty/tools/dotc/core/Types.scala               | 3 +--
 compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala  | 1 -
 compiler/src/dotty/tools/dotc/transform/AccessProxies.scala  | 1 -
 compiler/src/dotty/tools/dotc/transform/Erasure.scala        | 1 -
 .../src/dotty/tools/dotc/transform/ExtensionMethods.scala    | 1 -
 compiler/src/dotty/tools/dotc/transform/FirstTransform.scala | 1 -
 .../dotty/tools/dotc/transform/FullParameterization.scala    | 1 -
 .../src/dotty/tools/dotc/transform/GenericSignatures.scala   | 1 -
 .../src/dotty/tools/dotc/transform/ParamForwarding.scala     | 2 +-
 compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala | 1 -
 compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala | 2 +-
 .../src/dotty/tools/dotc/transform/TupleOptimizations.scala  | 1 -
 compiler/src/dotty/tools/dotc/transform/patmat/Space.scala   | 1 -
 compiler/src/dotty/tools/dotc/typer/Applications.scala       | 1 -
 compiler/src/dotty/tools/dotc/typer/Checking.scala           | 1 -
 compiler/src/dotty/tools/dotc/typer/ConstFold.scala          | 1 -
 compiler/src/dotty/tools/dotc/typer/Dynamic.scala            | 1 -
 compiler/src/dotty/tools/dotc/typer/Implicits.scala          | 1 -
 compiler/src/dotty/tools/dotc/typer/Inferencing.scala        | 1 -
 compiler/src/dotty/tools/dotc/typer/Namer.scala              | 1 -
 compiler/src/dotty/tools/dotc/typer/Synthesizer.scala        | 1 -
 compiler/src/dotty/tools/dotc/typer/Typer.scala              | 1 -
 29 files changed, 5 insertions(+), 33 deletions(-)
 rename compiler/src/dotty/tools/dotc/{transform => core}/TypeUtils.scala (99%)

diff --git a/compiler/src/dotty/tools/dotc/ast/tpd.scala b/compiler/src/dotty/tools/dotc/ast/tpd.scala
index 6f54f342dcb2..9ac123618ca2 100644
--- a/compiler/src/dotty/tools/dotc/ast/tpd.scala
+++ b/compiler/src/dotty/tools/dotc/ast/tpd.scala
@@ -5,7 +5,6 @@ package ast
 import dotty.tools.dotc.transform.{ExplicitOuter, Erasure}
 import typer.ProtoTypes
 import transform.SymUtils.*
-import transform.TypeUtils.*
 import core.*
 import Scopes.newScope
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, Flags.*, NameOps.*
diff --git a/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala b/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala
index 8857e1750e20..6be6ec94c1c3 100644
--- a/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala
+++ b/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala
@@ -10,7 +10,6 @@ import Flags.*
 import config.Config
 import config.Printers.typr
 import typer.ProtoTypes.{newTypeVar, representedParamRef}
-import transform.TypeUtils.isTransparent
 import UnificationDirection.*
 import NameKinds.AvoidNameKind
 import util.SimpleIdentitySet
diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index e18e1463f3ae..1ead0cee2858 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -23,7 +23,6 @@ import scala.util.control.NonFatal
 import config.Config
 import reporting.*
 import collection.mutable
-import transform.TypeUtils.*
 import cc.{CapturingType, derivedCapturingType}
 
 import scala.annotation.internal.sharable
diff --git a/compiler/src/dotty/tools/dotc/core/TypeApplications.scala b/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
index f16c04bc35b6..f1edd7cd8f8b 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
@@ -12,7 +12,6 @@ import Names.*
 import StdNames.nme
 import Flags.{Module, Provisional}
 import dotty.tools.dotc.config.Config
-import dotty.tools.dotc.transform.TypeUtils.isErasedValueType
 
 object TypeApplications {
 
diff --git a/compiler/src/dotty/tools/dotc/core/TypeComparer.scala b/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
index be55347649b3..a12a544616a1 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
@@ -16,7 +16,6 @@ import TypeErasure.{erasedLub, erasedGlb}
 import TypeApplications.*
 import Variances.{Variance, variancesConform}
 import Constants.Constant
-import transform.TypeUtils.*
 import transform.SymUtils.*
 import scala.util.control.NonFatal
 import typer.ProtoTypes.constrained
diff --git a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
index bdee683c8c8f..8b648c37e4ed 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
@@ -9,7 +9,6 @@ import TypeOps.makePackageObjPrefixExplicit
 import backend.sjs.JSDefinitions
 import transform.ExplicitOuter.*
 import transform.ValueClasses.*
-import transform.TypeUtils.*
 import transform.ContextFunctionResults.*
 import unpickleScala2.Scala2Erasure
 import Decorators.*
@@ -404,7 +403,6 @@ object TypeErasure {
       tp1 // After erasure, T | Nothing is just T and C | Null is just C, if C is a reference type.
     else tp1 match {
       case JavaArrayType(elem1) =>
-        import dotty.tools.dotc.transform.TypeUtils.*
         tp2 match {
           case JavaArrayType(elem2) =>
             if (elem1.isPrimitiveValueType || elem2.isPrimitiveValueType)
diff --git a/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala b/compiler/src/dotty/tools/dotc/core/TypeUtils.scala
similarity index 99%
rename from compiler/src/dotty/tools/dotc/transform/TypeUtils.scala
rename to compiler/src/dotty/tools/dotc/core/TypeUtils.scala
index 99c8e2fc7518..5df9379cb606 100644
--- a/compiler/src/dotty/tools/dotc/transform/TypeUtils.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeUtils.scala
@@ -1,13 +1,12 @@
 package dotty.tools
 package dotc
-package transform
+package core
 
-import core.*
 import TypeErasure.ErasedValueType
 import Types.*, Contexts.*, Symbols.*, Flags.*, Decorators.*
 import Names.Name
 
-object TypeUtils {
+class TypeUtils {
   /** A decorator that provides methods on types
    *  that are needed in the transformer pipeline.
    */
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
index c3fd07017cd0..e806254bc477 100644
--- a/compiler/src/dotty/tools/dotc/core/Types.scala
+++ b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -43,9 +43,8 @@ import scala.annotation.internal.sharable
 import scala.annotation.threadUnsafe
 
 import dotty.tools.dotc.transform.SymUtils.*
-import dotty.tools.dotc.transform.TypeUtils.isErasedClass
 
-object Types {
+object Types extends TypeUtils {
 
   @sharable private var nextId = 0
 
diff --git a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
index 6c61740e5b63..7e3ec3927af6 100644
--- a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
+++ b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
@@ -23,7 +23,6 @@ import Trees.*
 import TypeApplications.*
 import NameKinds.{WildcardParamName, DefaultGetterName}
 import util.Chars.isOperatorPart
-import transform.TypeUtils.*
 import transform.SymUtils.*
 import config.{Config, Feature}
 
diff --git a/compiler/src/dotty/tools/dotc/transform/AccessProxies.scala b/compiler/src/dotty/tools/dotc/transform/AccessProxies.scala
index c5ffde140bd6..237db90b315f 100644
--- a/compiler/src/dotty/tools/dotc/transform/AccessProxies.scala
+++ b/compiler/src/dotty/tools/dotc/transform/AccessProxies.scala
@@ -9,7 +9,6 @@ import Flags.*
 import Names.*
 import NameOps.*
 import Decorators.*
-import TypeUtils.*
 import Types.*
 import util.Spans.Span
 import config.Printers.transforms
diff --git a/compiler/src/dotty/tools/dotc/transform/Erasure.scala b/compiler/src/dotty/tools/dotc/transform/Erasure.scala
index 5f0854d31455..cf99711d92c2 100644
--- a/compiler/src/dotty/tools/dotc/transform/Erasure.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Erasure.scala
@@ -29,7 +29,6 @@ import dotty.tools.dotc.ast.{tpd, untpd}
 import ast.TreeTypeMap
 import dotty.tools.dotc.core.{Constants, Flags}
 import ValueClasses.*
-import TypeUtils.*
 import ContextFunctionResults.*
 import ExplicitOuter.*
 import core.Mode
diff --git a/compiler/src/dotty/tools/dotc/transform/ExtensionMethods.scala b/compiler/src/dotty/tools/dotc/transform/ExtensionMethods.scala
index 66b6759d9900..f0d1c687df8e 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExtensionMethods.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExtensionMethods.scala
@@ -15,7 +15,6 @@ import SymDenotations.*, Symbols.*, StdNames.*, Denotations.*
 import TypeErasure.{ valueErasure, ErasedValueType }
 import NameKinds.{ExtMethName, BodyRetainerName}
 import Decorators.*
-import TypeUtils.*
 
 /**
  * Perform Step 1 in the inline classes SIP: Creates extension methods for all
diff --git a/compiler/src/dotty/tools/dotc/transform/FirstTransform.scala b/compiler/src/dotty/tools/dotc/transform/FirstTransform.scala
index ce14d3d3c457..b5bc43ee762c 100644
--- a/compiler/src/dotty/tools/dotc/transform/FirstTransform.scala
+++ b/compiler/src/dotty/tools/dotc/transform/FirstTransform.scala
@@ -16,7 +16,6 @@ import DenotTransformers.*
 import NameOps.*
 import NameKinds.OuterSelectName
 import StdNames.*
-import TypeUtils.isErasedValueType
 import config.Feature
 import inlines.Inlines.inInlineMethod
 
diff --git a/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala b/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
index 7258b532d87a..dbb4c72ab311 100644
--- a/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
+++ b/compiler/src/dotty/tools/dotc/transform/FullParameterization.scala
@@ -6,7 +6,6 @@ import Types.*
 import Contexts.*
 import Symbols.*
 import Decorators.*
-import TypeUtils.*
 import StdNames.nme
 import ast.*
 
diff --git a/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala b/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
index 88297e88ce7d..22ca97c7129a 100644
--- a/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
+++ b/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
@@ -15,7 +15,6 @@ import core.TypeErasure.{erasedGlb, erasure, fullErasure, isGenericArrayElement,
 import core.Types.*
 import core.classfile.ClassfileConstants
 import SymUtils.*
-import TypeUtils.*
 import config.Printers.transforms
 import reporting.trace
 import java.lang.StringBuilder
diff --git a/compiler/src/dotty/tools/dotc/transform/ParamForwarding.scala b/compiler/src/dotty/tools/dotc/transform/ParamForwarding.scala
index 82ba3b7a1b7f..5c038cee2617 100644
--- a/compiler/src/dotty/tools/dotc/transform/ParamForwarding.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ParamForwarding.scala
@@ -3,7 +3,7 @@ package dotc
 package transform
 
 import core.*
-import Contexts.*, Types.*, Symbols.*, Flags.*, TypeUtils.*, DenotTransformers.*, StdNames.*
+import Contexts.*, Types.*, Symbols.*, Flags.*, DenotTransformers.*, StdNames.*
 import Decorators.*
 import MegaPhase.*
 import NameKinds.ParamAccessorName
diff --git a/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala b/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
index 05ef16961698..f417e90a91e7 100644
--- a/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
@@ -9,7 +9,6 @@ import patmat.SpaceEngine
 import util.Spans.*
 import typer.Applications.*
 import SymUtils.*
-import TypeUtils.*
 import Annotations.*
 import Flags.*, Constants.*
 import Decorators.*
diff --git a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
index 2d8d51b4059f..13ea452bcc9e 100644
--- a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
@@ -7,7 +7,7 @@ import scala.collection.mutable
 import ValueClasses.isMethodWithExtension
 import core.*
 import Contexts.*, Flags.*, Symbols.*, Names.*, StdNames.*, NameOps.*, Trees.*
-import TypeUtils.*, SymUtils.*
+import SymUtils.*
 import DenotTransformers.DenotTransformer
 import Symbols.*
 import util.Spans.*
diff --git a/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala b/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
index 5cdb13429a32..bdb7072a6530 100644
--- a/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TupleOptimizations.scala
@@ -10,7 +10,6 @@ import StdNames.*
 import Symbols.*
 import MegaPhase.*
 import Types.*
-import transform.TypeUtils.*
 import dotty.tools.dotc.ast.tpd
 
 /** Optimize generic operations on tuples */
diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
index 50f6a6becef6..e51f9c05bd62 100644
--- a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
+++ b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -5,7 +5,6 @@ package patmat
 
 import core.*
 import Types.*
-import TypeUtils.*
 import Contexts.*
 import Flags.*
 import ast.*
diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala
index 62cef94330c1..890783374c67 100644
--- a/compiler/src/dotty/tools/dotc/typer/Applications.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala
@@ -21,7 +21,6 @@ import NameKinds.DefaultGetterName
 import ProtoTypes.*
 import Inferencing.*
 import reporting.*
-import transform.TypeUtils.*
 import transform.SymUtils.*
 import Nullables.*, NullOpsDecorator.*
 import config.Feature
diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala
index 90c26e279d01..a56854e333fd 100644
--- a/compiler/src/dotty/tools/dotc/typer/Checking.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala
@@ -38,7 +38,6 @@ import config.Feature
 import config.Feature.sourceVersion
 import config.SourceVersion.*
 import printing.Formatting.hlAsKeyword
-import transform.TypeUtils.*
 import cc.isCaptureChecking
 
 import collection.mutable
diff --git a/compiler/src/dotty/tools/dotc/typer/ConstFold.scala b/compiler/src/dotty/tools/dotc/typer/ConstFold.scala
index 75894d2dd5b9..bd726afe5bba 100644
--- a/compiler/src/dotty/tools/dotc/typer/ConstFold.scala
+++ b/compiler/src/dotty/tools/dotc/typer/ConstFold.scala
@@ -11,7 +11,6 @@ import Constants.*
 import Names.*
 import StdNames.*
 import Contexts.*
-import transform.TypeUtils.*
 
 object ConstFold:
 
diff --git a/compiler/src/dotty/tools/dotc/typer/Dynamic.scala b/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
index 91f863eacfd3..6efc84031ec7 100644
--- a/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
@@ -18,7 +18,6 @@ import util.Spans.*
 import core.Symbols.*
 import ErrorReporting.*
 import dotty.tools.dotc.transform.ValueClasses
-import dotty.tools.dotc.transform.TypeUtils.isPrimitiveValueType
 import reporting.*
 import inlines.Inlines
 
diff --git a/compiler/src/dotty/tools/dotc/typer/Implicits.scala b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
index 97ef9ae21d40..ff23e8180f1c 100644
--- a/compiler/src/dotty/tools/dotc/typer/Implicits.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
@@ -24,7 +24,6 @@ import ErrorReporting.*
 import Inferencing.{fullyDefinedType, isFullyDefined}
 import Scopes.newScope
 import Typer.BindingPrec, BindingPrec.*
-import transform.TypeUtils.*
 import Hashable.*
 import util.{EqHashMap, Stats}
 import config.{Config, Feature}
diff --git a/compiler/src/dotty/tools/dotc/typer/Inferencing.scala b/compiler/src/dotty/tools/dotc/typer/Inferencing.scala
index 57620b32038b..7e35b8be8caa 100644
--- a/compiler/src/dotty/tools/dotc/typer/Inferencing.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Inferencing.scala
@@ -9,7 +9,6 @@ import ProtoTypes.*
 import NameKinds.UniqueName
 import util.Spans.*
 import util.{Stats, SimpleIdentityMap, SimpleIdentitySet, SrcPos}
-import transform.TypeUtils.isTransparent
 import Decorators._
 import config.Printers.{gadts, typr}
 import annotation.tailrec
diff --git a/compiler/src/dotty/tools/dotc/typer/Namer.scala b/compiler/src/dotty/tools/dotc/typer/Namer.scala
index cca26abdd1ec..74c63c41ec80 100644
--- a/compiler/src/dotty/tools/dotc/typer/Namer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Namer.scala
@@ -23,7 +23,6 @@ import parsing.Parsers.Parser
 import Annotations.*
 import Inferencing.*
 import transform.ValueClasses.*
-import transform.TypeUtils.*
 import transform.SymUtils.*
 import TypeErasure.erasure
 import reporting.*
diff --git a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
index d322176fa56d..aaebcfce690a 100644
--- a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
@@ -12,7 +12,6 @@ import ProtoTypes.*
 import Inferencing.{fullyDefinedType, isFullyDefined}
 import ast.untpd
 import transform.SymUtils.*
-import transform.TypeUtils.*
 import transform.SyntheticMembers.*
 import util.Property
 import ast.Trees.genericEmptyTree
diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala
index 6647b1050670..be9d3343b378 100644
--- a/compiler/src/dotty/tools/dotc/typer/Typer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala
@@ -46,7 +46,6 @@ import config.SourceVersion.*
 import rewrites.Rewrites.patch
 import staging.StagingLevel
 import transform.SymUtils.*
-import transform.TypeUtils.*
 import reporting.*
 import Nullables.*
 import NullOpsDecorator.*

From 125321e157af0e12cfddeeea526a5e87166fcd65 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Thu, 23 Nov 2023 15:53:35 +0100
Subject: [PATCH 3/3] Refactor SymUtils

 - Move to core package. It was for historical reasons in transform because
   it was originally intended as a collection of type operations that were
   were useful in transform phases. But it's now used from everywhere.
 - Make a base class of Types, so that it does not need to be imported explicitly.

Also: move isDerivedValueClass to SymUtils
---
 .../tools/backend/jvm/BCodeBodyBuilder.scala    |  1 -
 .../tools/backend/jvm/BCodeSkelBuilder.scala    |  2 +-
 .../tools/backend/jvm/BTypesFromSymbols.scala   |  2 +-
 .../src/dotty/tools/backend/jvm/CodeGen.scala   |  2 +-
 .../backend/jvm/DottyBackendInterface.scala     |  2 +-
 .../src/dotty/tools/backend/sjs/JSCodeGen.scala |  2 +-
 .../src/dotty/tools/dotc/CompilationUnit.scala  |  1 -
 compiler/src/dotty/tools/dotc/ast/Desugar.scala |  2 +-
 .../src/dotty/tools/dotc/ast/TreeInfo.scala     |  2 +-
 .../src/dotty/tools/dotc/ast/TreeTypeMap.scala  |  2 +-
 compiler/src/dotty/tools/dotc/ast/tpd.scala     |  1 -
 .../src/dotty/tools/dotc/cc/CheckCaptures.scala |  1 -
 .../dotty/tools/dotc/config/JavaPlatform.scala  |  2 +-
 .../dotc/{transform => core}/SymUtils.scala     | 16 ++++++++++++----
 .../src/dotty/tools/dotc/core/Symbols.scala     |  3 +--
 .../dotty/tools/dotc/core/TypeComparer.scala    |  1 -
 .../src/dotty/tools/dotc/core/TypeErasure.scala | 10 +++++-----
 .../src/dotty/tools/dotc/core/TypeOps.scala     |  1 -
 compiler/src/dotty/tools/dotc/core/Types.scala  |  2 +-
 .../tools/dotc/core/tasty/TreePickler.scala     |  1 -
 .../tools/dotc/core/tasty/TreeUnpickler.scala   |  1 -
 .../core/unpickleScala2/Scala2Unpickler.scala   |  1 -
 .../tools/dotc/inlines/InlineReducer.scala      |  1 -
 .../src/dotty/tools/dotc/inlines/Inliner.scala  |  1 -
 .../src/dotty/tools/dotc/inlines/Inlines.scala  |  1 -
 .../tools/dotc/inlines/PrepareInlineable.scala  |  1 -
 .../tools/dotc/interactive/Interactive.scala    |  1 -
 .../tools/dotc/printing/RefinedPrinter.scala    |  1 -
 .../dotty/tools/dotc/quoted/QuotePatterns.scala |  2 +-
 .../dotty/tools/dotc/reporting/DidYouMean.scala |  1 -
 .../dotty/tools/dotc/reporting/messages.scala   |  1 -
 .../src/dotty/tools/dotc/sbt/ExtractAPI.scala   |  3 +--
 .../tools/dotc/sbt/ExtractDependencies.scala    |  2 +-
 .../dotc/semanticdb/ExtractSemanticDB.scala     |  1 -
 .../src/dotty/tools/dotc/staging/HealType.scala |  2 +-
 .../dotc/transform/ArrayConstructors.scala      |  4 ++--
 .../tools/dotc/transform/BeanProperties.scala   |  2 +-
 .../tools/dotc/transform/CheckShadowing.scala   |  3 +--
 .../tools/dotc/transform/CheckStatic.scala      |  2 +-
 .../dotc/transform/CollectNullableFields.scala  |  2 +-
 .../dotc/transform/CompleteJavaEnums.scala      |  2 +-
 .../tools/dotc/transform/Constructors.scala     |  2 +-
 .../tools/dotc/transform/Dependencies.scala     |  2 +-
 .../dotty/tools/dotc/transform/EtaReduce.scala  |  2 +-
 .../dotty/tools/dotc/transform/ExpandSAMs.scala |  2 +-
 .../tools/dotc/transform/ExplicitOuter.scala    |  2 +-
 .../tools/dotc/transform/ExplicitSelf.scala     |  2 +-
 .../dotc/transform/GenericSignatures.scala      |  4 ++--
 .../dotty/tools/dotc/transform/Getters.scala    |  5 ++---
 .../tools/dotc/transform/HoistSuperArgs.scala   |  2 +-
 .../dotty/tools/dotc/transform/Inlining.scala   |  2 +-
 .../dotty/tools/dotc/transform/LambdaLift.scala |  2 +-
 .../dotty/tools/dotc/transform/LazyVals.scala   |  1 -
 .../dotty/tools/dotc/transform/Memoize.scala    |  2 +-
 .../src/dotty/tools/dotc/transform/Mixin.scala  |  2 +-
 .../dotty/tools/dotc/transform/MixinOps.scala   |  2 +-
 .../tools/dotc/transform/MoveStatics.scala      |  2 +-
 .../tools/dotc/transform/PatternMatcher.scala   |  4 ++--
 .../tools/dotc/transform/PickleQuotes.scala     |  2 +-
 .../dotty/tools/dotc/transform/PostTyper.scala  |  2 +-
 .../tools/dotc/transform/PruneErasedDefs.scala  |  2 +-
 .../dotty/tools/dotc/transform/Recheck.scala    |  2 +-
 .../tools/dotc/transform/ReifiedReflect.scala   |  2 +-
 .../tools/dotc/transform/ResolveSuper.scala     |  2 +-
 .../tools/dotc/transform/SelectStatic.scala     |  2 +-
 .../dotty/tools/dotc/transform/Splicing.scala   |  2 +-
 .../dotty/tools/dotc/transform/Staging.scala    |  2 +-
 .../tools/dotc/transform/SuperAccessors.scala   |  2 +-
 .../tools/dotc/transform/SyntheticMembers.scala | 17 ++++++++---------
 .../tools/dotc/transform/TypeTestsCasts.scala   |  5 ++---
 .../tools/dotc/transform/ValueClasses.scala     |  9 ---------
 .../tools/dotc/transform/patmat/Space.scala     |  1 -
 .../dotc/transform/sjs/ExplicitJSClasses.scala  |  2 +-
 .../tools/dotc/transform/sjs/JSSymUtils.scala   |  2 +-
 .../dotc/transform/sjs/PrepJSExports.scala      |  2 +-
 .../dotc/transform/sjs/PrepJSInterop.scala      |  2 +-
 .../dotty/tools/dotc/typer/Applications.scala   |  1 -
 .../src/dotty/tools/dotc/typer/Checking.scala   |  5 ++---
 .../tools/dotc/typer/CrossVersionChecks.scala   |  2 +-
 .../src/dotty/tools/dotc/typer/Dynamic.scala    |  4 ++--
 compiler/src/dotty/tools/dotc/typer/Namer.scala |  1 -
 .../tools/dotc/typer/QuotesAndSplices.scala     |  2 +-
 .../src/dotty/tools/dotc/typer/RefChecks.scala  |  2 +-
 .../dotty/tools/dotc/typer/Synthesizer.scala    |  1 -
 compiler/src/dotty/tools/dotc/typer/Typer.scala |  1 -
 .../src/dotty/tools/dotc/util/Signatures.scala  |  3 +--
 compiler/src/dotty/tools/repl/Rendering.scala   |  3 +--
 .../tools/pc/completions/CompletionValue.scala  |  1 -
 .../tools/pc/completions/Completions.scala      |  1 -
 .../pc/completions/KeywordsCompletions.scala    |  1 -
 90 files changed, 91 insertions(+), 128 deletions(-)
 rename compiler/src/dotty/tools/dotc/{transform => core}/SymUtils.scala (97%)

diff --git a/compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala b/compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala
index f1029b702ee5..db52a74300ef 100644
--- a/compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala
+++ b/compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala
@@ -19,7 +19,6 @@ import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.core.StdNames.{nme, str}
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.transform.Erasure
-import dotty.tools.dotc.transform.SymUtils.*
 import dotty.tools.dotc.util.Spans.*
 import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.core.Phases.*
diff --git a/compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala b/compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala
index 61383d2000d1..0ab9ed85b6cf 100644
--- a/compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala
+++ b/compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala
@@ -20,7 +20,7 @@ import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.util.Spans.*
 import dotty.tools.dotc.report
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 /*
  *
diff --git a/compiler/src/dotty/tools/backend/jvm/BTypesFromSymbols.scala b/compiler/src/dotty/tools/backend/jvm/BTypesFromSymbols.scala
index 0743465b7b3b..55619f31ec32 100644
--- a/compiler/src/dotty/tools/backend/jvm/BTypesFromSymbols.scala
+++ b/compiler/src/dotty/tools/backend/jvm/BTypesFromSymbols.scala
@@ -12,7 +12,7 @@ import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.core.Phases.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Phases.Phase
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.core.StdNames
 import dotty.tools.dotc.core.Phases
 
diff --git a/compiler/src/dotty/tools/backend/jvm/CodeGen.scala b/compiler/src/dotty/tools/backend/jvm/CodeGen.scala
index a477e55e2b68..3d63159eea16 100644
--- a/compiler/src/dotty/tools/backend/jvm/CodeGen.scala
+++ b/compiler/src/dotty/tools/backend/jvm/CodeGen.scala
@@ -9,7 +9,7 @@ import dotty.tools.dotc.core.Phases.Phase
 
 import scala.collection.mutable
 import scala.jdk.CollectionConverters.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.interfaces
 import dotty.tools.dotc.report
 
diff --git a/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala b/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
index 30568ef92b2d..37045bda17ec 100644
--- a/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
+++ b/compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala
@@ -4,7 +4,7 @@ import scala.language.unsafeNulls
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core.Flags.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 import java.io.{File => _}
 
 import scala.reflect.ClassTag
diff --git a/compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala b/compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala
index 6f8b3fc6f135..54af9f8dd088 100644
--- a/compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala
+++ b/compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala
@@ -21,7 +21,7 @@ import StdNames.*
 import TypeErasure.ErasedValueType
 
 import dotty.tools.dotc.transform.{Erasure, ValueClasses}
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.util.SourcePosition
 import dotty.tools.dotc.report
 
diff --git a/compiler/src/dotty/tools/dotc/CompilationUnit.scala b/compiler/src/dotty/tools/dotc/CompilationUnit.scala
index 686414a4fd9b..62f62a3c6dc6 100644
--- a/compiler/src/dotty/tools/dotc/CompilationUnit.scala
+++ b/compiler/src/dotty/tools/dotc/CompilationUnit.scala
@@ -12,7 +12,6 @@ import ast.{tpd, untpd}
 import tpd.{Tree, TreeTraverser}
 import ast.Trees.{Import, Ident}
 import typer.Nullables
-import transform.SymUtils.*
 import core.Decorators.*
 import config.{SourceVersion, Feature}
 import StdNames.nme
diff --git a/compiler/src/dotty/tools/dotc/ast/Desugar.scala b/compiler/src/dotty/tools/dotc/ast/Desugar.scala
index f85075cd2de8..a08d6da650c9 100644
--- a/compiler/src/dotty/tools/dotc/ast/Desugar.scala
+++ b/compiler/src/dotty/tools/dotc/ast/Desugar.scala
@@ -5,7 +5,7 @@ package ast
 import core.*
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, NameOps.*, Flags.*
 import Symbols.*, StdNames.*, Trees.*, ContextOps.*
-import Decorators.*, transform.SymUtils.*
+import Decorators.*
 import Annotations.Annotation
 import NameKinds.{UniqueName, ContextBoundParamName, ContextFunctionParamName, DefaultGetterName, WildcardParamName}
 import typer.{Namer, Checking}
diff --git a/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala b/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
index eae62dde41e6..5ded0e1262e4 100644
--- a/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
+++ b/compiler/src/dotty/tools/dotc/ast/TreeInfo.scala
@@ -7,7 +7,7 @@ import Flags.*, Trees.*, Types.*, Contexts.*
 import Names.*, StdNames.*, NameOps.*, Symbols.*
 import typer.ConstFold
 import reporting.trace
-import dotty.tools.dotc.transform.SymUtils.*
+
 import Decorators.*
 import Constants.Constant
 import scala.collection.mutable
diff --git a/compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala b/compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala
index 15c61bc2b8d4..668daea5f1fd 100644
--- a/compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala
+++ b/compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala
@@ -6,7 +6,7 @@ import core.*
 import Types.*, Contexts.*, Flags.*
 import Symbols.*, Annotations.*, Trees.*, Symbols.*, Constants.Constant
 import Decorators.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 /** A map that applies three functions and a substitution together to a tree and
  *  makes sure they are coordinated so that the result is well-typed. The functions are
diff --git a/compiler/src/dotty/tools/dotc/ast/tpd.scala b/compiler/src/dotty/tools/dotc/ast/tpd.scala
index 9ac123618ca2..b4b1c685f33a 100644
--- a/compiler/src/dotty/tools/dotc/ast/tpd.scala
+++ b/compiler/src/dotty/tools/dotc/ast/tpd.scala
@@ -4,7 +4,6 @@ package ast
 
 import dotty.tools.dotc.transform.{ExplicitOuter, Erasure}
 import typer.ProtoTypes
-import transform.SymUtils.*
 import core.*
 import Scopes.newScope
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, Flags.*, NameOps.*
diff --git a/compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala b/compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala
index 7c35568d7ce9..d635096b2318 100644
--- a/compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala
+++ b/compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala
@@ -15,7 +15,6 @@ import typer.Checking.{checkBounds, checkAppliedTypesIn}
 import typer.ErrorReporting.{Addenda, err}
 import typer.ProtoTypes.{AnySelectionProto, LhsProto}
 import util.{SimpleIdentitySet, EqHashMap, EqHashSet, SrcPos, Property}
-import transform.SymUtils.*
 import transform.{Recheck, PreRecheck, CapturedVars}
 import Recheck.*
 import scala.collection.mutable
diff --git a/compiler/src/dotty/tools/dotc/config/JavaPlatform.scala b/compiler/src/dotty/tools/dotc/config/JavaPlatform.scala
index ed8ef6c8372e..f3c2f295ce82 100644
--- a/compiler/src/dotty/tools/dotc/config/JavaPlatform.scala
+++ b/compiler/src/dotty/tools/dotc/config/JavaPlatform.scala
@@ -7,7 +7,7 @@ import classpath.AggregateClassPath
 import core.*
 import Symbols.*, Types.*, Contexts.*, StdNames.*
 import Flags.*
-import transform.ExplicitOuter, transform.SymUtils.*
+import transform.ExplicitOuter
 
 class JavaPlatform extends Platform {
 
diff --git a/compiler/src/dotty/tools/dotc/transform/SymUtils.scala b/compiler/src/dotty/tools/dotc/core/SymUtils.scala
similarity index 97%
rename from compiler/src/dotty/tools/dotc/transform/SymUtils.scala
rename to compiler/src/dotty/tools/dotc/core/SymUtils.scala
index ddee2588b152..e0e5c7a7cb87 100644
--- a/compiler/src/dotty/tools/dotc/transform/SymUtils.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymUtils.scala
@@ -1,5 +1,5 @@
 package dotty.tools.dotc
-package transform
+package core
 
 import core.*
 import Types.*
@@ -11,18 +11,18 @@ import NameOps.*
 import StdNames.*
 import NameKinds.*
 import Flags.*
-import ValueClasses.isDerivedValueClass
 import Decorators.*
 import Constants.Constant
 import Annotations.Annotation
 import Phases.*
 import ast.tpd.Literal
+import transform.Mixin
 
 import dotty.tools.dotc.transform.sjs.JSSymUtils.sjsNeedsField
 
 import scala.annotation.tailrec
 
-object SymUtils:
+class SymUtils:
 
   extension (self: Symbol)
 
@@ -79,6 +79,14 @@ object SymUtils:
       self.is(Enum, butNot = Case) &&
       self.info.parents.exists(p => p.typeSymbol == defn.JavaEnumClass)
 
+    def isDerivedValueClass(using Context): Boolean = self.isClass && {
+      val d = self.denot
+      !d.isRefinementClass &&
+      d.isValueClass &&
+      (d.initial.symbol ne defn.AnyValClass) && // Compare the initial symbol because AnyVal does not exist after erasure
+      !d.isPrimitiveValueClass
+    }
+
     /** Is this a case class for which a product mirror is generated?
     *  Excluded are value classes, abstract classes and case classes with more than one
     *  parameter section.
@@ -100,7 +108,7 @@ object SymUtils:
       if (!self.is(CaseClass)) "it is not a case class"
       else if (self.is(Abstract)) "it is an abstract class"
       else if (self.primaryConstructor.info.paramInfoss.length != 1) "it takes more than one parameter list"
-      else if (isDerivedValueClass(self)) "it is a value class"
+      else if self.isDerivedValueClass then "it is a value class"
       else if (!(companionMirror || canAccessCtor)) s"the constructor of $self is inaccessible from the calling scope."
       else ""
     end whyNotGenericProduct
diff --git a/compiler/src/dotty/tools/dotc/core/Symbols.scala b/compiler/src/dotty/tools/dotc/core/Symbols.scala
index a41d194693e6..60c66dea2cb6 100644
--- a/compiler/src/dotty/tools/dotc/core/Symbols.scala
+++ b/compiler/src/dotty/tools/dotc/core/Symbols.scala
@@ -18,7 +18,6 @@ import util.Spans.*
 import DenotTransformers.*
 import StdNames.*
 import NameOps.*
-import transform.SymUtils.*
 import NameKinds.LazyImplicitName
 import ast.tpd
 import tpd.{Tree, TreeProvider, TreeOps}
@@ -35,7 +34,7 @@ import dotty.tools.dotc.classpath.FileUtils.isScalaBinary
 
 import scala.compiletime.uninitialized
 
-object Symbols {
+object Symbols extends SymUtils {
 
   implicit def eqSymbol: CanEqual[Symbol, Symbol] = CanEqual.derived
 
diff --git a/compiler/src/dotty/tools/dotc/core/TypeComparer.scala b/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
index a12a544616a1..76236d635182 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
@@ -16,7 +16,6 @@ import TypeErasure.{erasedLub, erasedGlb}
 import TypeApplications.*
 import Variances.{Variance, variancesConform}
 import Constants.Constant
-import transform.SymUtils.*
 import scala.util.control.NonFatal
 import typer.ProtoTypes.constrained
 import typer.Applications.productSelectorTypes
diff --git a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
index 8b648c37e4ed..48559787c6a1 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeErasure.scala
@@ -71,7 +71,7 @@ end SourceLanguage
 object TypeErasure {
 
   private def erasureDependsOnArgs(sym: Symbol)(using Context) =
-    sym == defn.ArrayClass || sym == defn.PairClass || isDerivedValueClass(sym)
+    sym == defn.ArrayClass || sym == defn.PairClass || sym.isDerivedValueClass
 
   /** The arity of this tuple type, which can be made up of EmptyTuple, TupleX and `*:` pairs.
    *
@@ -125,7 +125,7 @@ object TypeErasure {
     case tp: TypeRef =>
       val sym = tp.symbol
       sym.isClass &&
-      (!erasureDependsOnArgs(sym) || isDerivedValueClass(sym)) &&
+      (!erasureDependsOnArgs(sym) || sym.isDerivedValueClass) &&
       !defn.specialErasure.contains(sym) &&
       !defn.isSyntheticFunctionClass(sym)
     case _: TermRef =>
@@ -630,7 +630,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
       case tp: TypeRef =>
         val sym = tp.symbol
         if !sym.isClass then this(checkedSuperType(tp))
-        else if semiEraseVCs && isDerivedValueClass(sym) then eraseDerivedValueClass(tp)
+        else if semiEraseVCs && sym.isDerivedValueClass then eraseDerivedValueClass(tp)
         else if defn.isSyntheticFunctionClass(sym) then defn.functionTypeErasure(sym)
         else eraseNormalClassRef(tp)
       case tp: AppliedType =>
@@ -638,7 +638,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
         if (tycon.isRef(defn.ArrayClass)) eraseArray(tp)
         else if (tycon.isRef(defn.PairClass)) erasePair(tp)
         else if (tp.isRepeatedParam) apply(tp.translateFromRepeated(toArray = sourceLanguage.isJava))
-        else if (semiEraseVCs && isDerivedValueClass(tycon.classSymbol)) eraseDerivedValueClass(tp)
+        else if (semiEraseVCs && tycon.classSymbol.isDerivedValueClass) eraseDerivedValueClass(tp)
         else this(checkedSuperType(tp))
       case tp: TermRef =>
         this(underlyingOfTermRef(tp))
@@ -898,7 +898,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
           if (!info.exists) assert(false, i"undefined: $tp with symbol $sym")
           return sigName(info)
         }
-        if (semiEraseVCs && isDerivedValueClass(sym)) {
+        if (semiEraseVCs && sym.isDerivedValueClass) {
           val erasedVCRef = eraseDerivedValueClass(tp)
           if (erasedVCRef.exists) return sigName(erasedVCRef)
         }
diff --git a/compiler/src/dotty/tools/dotc/core/TypeOps.scala b/compiler/src/dotty/tools/dotc/core/TypeOps.scala
index 7f9f7099d805..37f29386c44d 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeOps.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeOps.scala
@@ -13,7 +13,6 @@ import ast.tpd.*
 import reporting.trace
 import config.Printers.typr
 import config.Feature
-import transform.SymUtils.*
 import typer.ProtoTypes.*
 import typer.ForceDegree
 import typer.Inferencing.*
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
index e806254bc477..e5c166f28d78 100644
--- a/compiler/src/dotty/tools/dotc/core/Types.scala
+++ b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -42,7 +42,7 @@ import CaptureSet.{CompareResult, IdempotentCaptRefMap, IdentityCaptRefMap}
 import scala.annotation.internal.sharable
 import scala.annotation.threadUnsafe
 
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 object Types extends TypeUtils {
 
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala
index 2e4fe9967d6a..b4ba58c55c93 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala
@@ -14,7 +14,6 @@ import Contexts.*, Symbols.*, Types.*, Names.*, Constants.*, Decorators.*, Annot
 import Comments.{Comment, CommentsContext}
 import NameKinds.*
 import StdNames.nme
-import transform.SymUtils.*
 import config.Config
 import collection.mutable
 import reporting.{Profile, NoProfile}
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
index c366146a789e..4b80768e1322 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
@@ -31,7 +31,6 @@ import util.{SourceFile, Property}
 import ast.{Trees, tpd, untpd}
 import Trees.*
 import Decorators.*
-import transform.SymUtils.*
 import dotty.tools.dotc.quoted.QuotePatterns
 
 import dotty.tools.tasty.{TastyBuffer, TastyReader}
diff --git a/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala b/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
index b5ee0e0525b4..aeff3b16f550 100644
--- a/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala
@@ -23,7 +23,6 @@ import util.common.*
 import util.NoSourcePosition
 import typer.Checking.checkNonCyclic
 import typer.Nullables.*
-import transform.SymUtils.*
 import PickleBuffer.*
 import PickleFormat.*
 import Decorators.*
diff --git a/compiler/src/dotty/tools/dotc/inlines/InlineReducer.scala b/compiler/src/dotty/tools/dotc/inlines/InlineReducer.scala
index 029616502c8c..26fd52fb7138 100644
--- a/compiler/src/dotty/tools/dotc/inlines/InlineReducer.scala
+++ b/compiler/src/dotty/tools/dotc/inlines/InlineReducer.scala
@@ -5,7 +5,6 @@ package inlines
 import ast.*, core.*
 import Flags.*, Symbols.*, Types.*, Decorators.*, Contexts.*
 import StdNames.nme
-import transform.SymUtils.*
 import typer.*
 import Names.TermName
 import NameKinds.{InlineAccessorName, InlineBinderName, InlineScrutineeName}
diff --git a/compiler/src/dotty/tools/dotc/inlines/Inliner.scala b/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
index 07472ee9b4dd..8bd89a71fa50 100644
--- a/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
+++ b/compiler/src/dotty/tools/dotc/inlines/Inliner.scala
@@ -4,7 +4,6 @@ package inlines
 
 import ast.*, core.*
 import Flags.*, Symbols.*, Types.*, Decorators.*, Constants.*, Contexts.*
-import transform.SymUtils.*
 import StdNames.nme
 import typer.*
 import Names.Name
diff --git a/compiler/src/dotty/tools/dotc/inlines/Inlines.scala b/compiler/src/dotty/tools/dotc/inlines/Inlines.scala
index 5bdd0bb98495..c040c15f5d60 100644
--- a/compiler/src/dotty/tools/dotc/inlines/Inlines.scala
+++ b/compiler/src/dotty/tools/dotc/inlines/Inlines.scala
@@ -5,7 +5,6 @@ package inlines
 import ast.*, core.*
 import Flags.*, Symbols.*, Types.*, Decorators.*, Constants.*, Contexts.*
 import StdNames.{tpnme, nme}
-import transform.SymUtils.*
 import typer.*
 import NameKinds.BodyRetainerName
 import SymDenotations.SymDenotation
diff --git a/compiler/src/dotty/tools/dotc/inlines/PrepareInlineable.scala b/compiler/src/dotty/tools/dotc/inlines/PrepareInlineable.scala
index 10b55d69bf37..0b5c72bd997f 100644
--- a/compiler/src/dotty/tools/dotc/inlines/PrepareInlineable.scala
+++ b/compiler/src/dotty/tools/dotc/inlines/PrepareInlineable.scala
@@ -19,7 +19,6 @@ import NameOps.*
 import Annotations.*
 import transform.{AccessProxies, Splicer}
 import staging.CrossStageSafety
-import transform.SymUtils.*
 import config.Printers.inlining
 import util.Property
 import staging.StagingLevel
diff --git a/compiler/src/dotty/tools/dotc/interactive/Interactive.scala b/compiler/src/dotty/tools/dotc/interactive/Interactive.scala
index 6c8e3b61cd01..3f3e5e25f66e 100644
--- a/compiler/src/dotty/tools/dotc/interactive/Interactive.scala
+++ b/compiler/src/dotty/tools/dotc/interactive/Interactive.scala
@@ -10,7 +10,6 @@ import ast.{NavigateAST, Trees, tpd, untpd}
 import core.*
 import Decorators.*, ContextOps.*
 import Contexts.*, Flags.*, Names.*, NameOps.*, Symbols.*, Trees.*, Types.*
-import transform.SymUtils.*
 import util.Spans.*, util.SourceFile, util.SourcePosition
 
 /** High-level API to get information out of typed trees, designed to be used by IDEs.
diff --git a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
index 7e3ec3927af6..8ad1188a3e7e 100644
--- a/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
+++ b/compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala
@@ -23,7 +23,6 @@ import Trees.*
 import TypeApplications.*
 import NameKinds.{WildcardParamName, DefaultGetterName}
 import util.Chars.isOperatorPart
-import transform.SymUtils.*
 import config.{Config, Feature}
 
 import dotty.tools.dotc.util.SourcePosition
diff --git a/compiler/src/dotty/tools/dotc/quoted/QuotePatterns.scala b/compiler/src/dotty/tools/dotc/quoted/QuotePatterns.scala
index eb5395194d11..76961f691617 100644
--- a/compiler/src/dotty/tools/dotc/quoted/QuotePatterns.scala
+++ b/compiler/src/dotty/tools/dotc/quoted/QuotePatterns.scala
@@ -18,7 +18,7 @@ import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.TypeOps.*
 import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.reporting.IllegalVariableInPatternAlternative
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 import scala.collection.mutable
 
diff --git a/compiler/src/dotty/tools/dotc/reporting/DidYouMean.scala b/compiler/src/dotty/tools/dotc/reporting/DidYouMean.scala
index a9b2f68d07d6..04b9b518fd5e 100644
--- a/compiler/src/dotty/tools/dotc/reporting/DidYouMean.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/DidYouMean.scala
@@ -6,7 +6,6 @@ import core.*
 import Contexts.*
 import Decorators.*, Symbols.*, Names.*, Types.*, Flags.*
 import typer.ProtoTypes.{FunProto, SelectionProto}
-import transform.SymUtils.isNoValue
 
 /** A utility object to support "did you mean" hinting */
 object DidYouMean:
diff --git a/compiler/src/dotty/tools/dotc/reporting/messages.scala b/compiler/src/dotty/tools/dotc/reporting/messages.scala
index 5c7eb1d0f775..b6622d67f36a 100644
--- a/compiler/src/dotty/tools/dotc/reporting/messages.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/messages.scala
@@ -25,7 +25,6 @@ import printing.Formatting.hl
 import ast.Trees.*
 import ast.untpd
 import ast.tpd
-import transform.SymUtils.*
 import scala.util.matching.Regex
 import java.util.regex.Matcher.quoteReplacement
 import cc.CaptureSet.IdentityCaptRefMap
diff --git a/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala b/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala
index 5561a241c975..bb1d2afd04d6 100644
--- a/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala
+++ b/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala
@@ -18,7 +18,6 @@ import Names.*
 import NameOps.*
 import inlines.Inlines
 import transform.ValueClasses
-import transform.SymUtils.*
 import dotty.tools.io.File
 import java.io.PrintWriter
 
@@ -274,7 +273,7 @@ private class ExtractAPICollector(using Context) extends ThunkHolder {
             report.error(ex, csym.sourcePos)
             defn.ObjectType :: Nil
         }
-      if (ValueClasses.isDerivedValueClass(csym)) {
+      if (csym.isDerivedValueClass) {
         val underlying = ValueClasses.valueClassUnbox(csym).info.finalResultType
         // The underlying type of a value class should be part of the name hash
         // of the value class (see the test `value-class-underlying`), this is accomplished
diff --git a/compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala b/compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala
index fbf6e08f8b60..36982633e881 100644
--- a/compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala
+++ b/compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala
@@ -18,7 +18,7 @@ import dotty.tools.dotc.core.Phases.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Denotations.StaleSymbol
 import dotty.tools.dotc.core.Types.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.util.{SrcPos, NoSourcePosition}
 import dotty.tools.io
 import dotty.tools.io.{AbstractFile, PlainFile, ZipArchive, NoAbstractFile}
diff --git a/compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala b/compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala
index 75805d4aed17..77eef4564bbf 100644
--- a/compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala
+++ b/compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala
@@ -17,7 +17,6 @@ import NameOps.*
 import Denotations.StaleSymbol
 import util.Spans.Span
 import util.SourceFile
-import transform.SymUtils.*
 
 import scala.collection.mutable
 import scala.annotation.{ threadUnsafe => tu, tailrec }
diff --git a/compiler/src/dotty/tools/dotc/staging/HealType.scala b/compiler/src/dotty/tools/dotc/staging/HealType.scala
index 2469bd73bdcb..8b77f0774cdc 100644
--- a/compiler/src/dotty/tools/dotc/staging/HealType.scala
+++ b/compiler/src/dotty/tools/dotc/staging/HealType.scala
@@ -9,7 +9,7 @@ import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.staging.StagingLevel.*
 import dotty.tools.dotc.staging.QuoteTypeTags.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.typer.Implicits.SearchFailureType
 import dotty.tools.dotc.util.SrcPos
 
diff --git a/compiler/src/dotty/tools/dotc/transform/ArrayConstructors.scala b/compiler/src/dotty/tools/dotc/transform/ArrayConstructors.scala
index b0106f0d2ff3..e94fa612e6cf 100644
--- a/compiler/src/dotty/tools/dotc/transform/ArrayConstructors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ArrayConstructors.scala
@@ -38,10 +38,10 @@ class ArrayConstructors extends MiniPhase {
       val cs = tp.tpe.classSymbol
       tree.fun match {
         case Apply(TypeApply(t: Ident, targ), dims)
-          if !TypeErasure.isGeneric(targ.head.tpe) && !ValueClasses.isDerivedValueClass(cs) =>
+          if !TypeErasure.isGeneric(targ.head.tpe) && !cs.isDerivedValueClass =>
           expand(targ.head.tpe, dims)
         case Apply(TypeApply(t: Select, targ), dims)
-          if !TypeErasure.isGeneric(targ.head.tpe) && !ValueClasses.isDerivedValueClass(cs) =>
+          if !TypeErasure.isGeneric(targ.head.tpe) && !cs.isDerivedValueClass =>
           Block(t.qualifier :: Nil, expand(targ.head.tpe, dims))
         case _ => tree
       }
diff --git a/compiler/src/dotty/tools/dotc/transform/BeanProperties.scala b/compiler/src/dotty/tools/dotc/transform/BeanProperties.scala
index 7e21703f67ee..57aeb93a3b61 100644
--- a/compiler/src/dotty/tools/dotc/transform/BeanProperties.scala
+++ b/compiler/src/dotty/tools/dotc/transform/BeanProperties.scala
@@ -6,7 +6,7 @@ import ast.tpd.*
 import Annotations.*
 import Contexts.*
 import Symbols.*
-import SymUtils.*
+
 import Decorators.*
 import Flags.*
 import Names.*
diff --git a/compiler/src/dotty/tools/dotc/transform/CheckShadowing.scala b/compiler/src/dotty/tools/dotc/transform/CheckShadowing.scala
index fdc055df9ac4..a85cabdd5460 100644
--- a/compiler/src/dotty/tools/dotc/transform/CheckShadowing.scala
+++ b/compiler/src/dotty/tools/dotc/transform/CheckShadowing.scala
@@ -19,8 +19,7 @@ import dotty.tools.dotc.core.Types.Type
 import dotty.tools.dotc.core.Types
 import dotty.tools.dotc.semanticdb.TypeOps
 import dotty.tools.dotc.cc.boxedCaptureSet
-import dotty.tools.dotc.core.Symbols.NoSymbol
-import dotty.tools.dotc.transform.SymUtils.isParamOrAccessor
+import dotty.tools.dotc.core.Symbols.{NoSymbol, isParamOrAccessor}
 import scala.collection.mutable
 import dotty.tools.dotc.core.Scopes.Scope
 import scala.collection.immutable.HashMap
diff --git a/compiler/src/dotty/tools/dotc/transform/CheckStatic.scala b/compiler/src/dotty/tools/dotc/transform/CheckStatic.scala
index 2b616bad0a01..26c94407f35b 100644
--- a/compiler/src/dotty/tools/dotc/transform/CheckStatic.scala
+++ b/compiler/src/dotty/tools/dotc/transform/CheckStatic.scala
@@ -9,7 +9,7 @@ import Symbols.*
 import dotty.tools.dotc.ast.tpd
 import reporting.*
 
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 /** A transformer that check that requirements of Static fields\methods are implemented:
   *  1. Only objects can have members annotated with `@static`
diff --git a/compiler/src/dotty/tools/dotc/transform/CollectNullableFields.scala b/compiler/src/dotty/tools/dotc/transform/CollectNullableFields.scala
index 22739dc528c8..9433f7949163 100644
--- a/compiler/src/dotty/tools/dotc/transform/CollectNullableFields.scala
+++ b/compiler/src/dotty/tools/dotc/transform/CollectNullableFields.scala
@@ -5,7 +5,7 @@ import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.Symbols.Symbol
 import dotty.tools.dotc.transform.MegaPhase.MiniPhase
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 import scala.collection.mutable
 
diff --git a/compiler/src/dotty/tools/dotc/transform/CompleteJavaEnums.scala b/compiler/src/dotty/tools/dotc/transform/CompleteJavaEnums.scala
index eac0b9f05c60..5740f359cb77 100644
--- a/compiler/src/dotty/tools/dotc/transform/CompleteJavaEnums.scala
+++ b/compiler/src/dotty/tools/dotc/transform/CompleteJavaEnums.scala
@@ -13,7 +13,7 @@ import Symbols.*
 import Constants.*
 import Decorators.*
 import DenotTransformers.*
-import SymUtils.*
+
 
 
 object CompleteJavaEnums {
diff --git a/compiler/src/dotty/tools/dotc/transform/Constructors.scala b/compiler/src/dotty/tools/dotc/transform/Constructors.scala
index e465e42fe8d8..9a0df830c6d7 100644
--- a/compiler/src/dotty/tools/dotc/transform/Constructors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Constructors.scala
@@ -10,7 +10,7 @@ import Flags.*
 import Names.Name
 import NameOps.*
 import NameKinds.{FieldName, ExplicitFieldName}
-import SymUtils.*
+
 import Symbols.*
 import Decorators.*
 import DenotTransformers.*
diff --git a/compiler/src/dotty/tools/dotc/transform/Dependencies.scala b/compiler/src/dotty/tools/dotc/transform/Dependencies.scala
index 9b1b931e0320..fe429992fd46 100644
--- a/compiler/src/dotty/tools/dotc/transform/Dependencies.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Dependencies.scala
@@ -3,7 +3,7 @@ package transform
 
 import core.*
 import Symbols.*, Contexts.*, Types.*, Flags.*, Decorators.*
-import SymUtils.*
+
 import collection.mutable.{LinkedHashMap, LinkedHashSet}
 import annotation.constructorOnly
 import scala.compiletime.uninitialized
diff --git a/compiler/src/dotty/tools/dotc/transform/EtaReduce.scala b/compiler/src/dotty/tools/dotc/transform/EtaReduce.scala
index b8b10d355ede..a8565d008f46 100644
--- a/compiler/src/dotty/tools/dotc/transform/EtaReduce.scala
+++ b/compiler/src/dotty/tools/dotc/transform/EtaReduce.scala
@@ -6,7 +6,7 @@ import MegaPhase.MiniPhase
 import core.*
 import Symbols.*, Contexts.*, Types.*, Decorators.*
 import StdNames.nme
-import SymUtils.*
+
 import NameKinds.AdaptedClosureName
 
 /** Rewrite `(x1, ... xN) => f(x1, ... xN)` for N >= 0 to `f`,
diff --git a/compiler/src/dotty/tools/dotc/transform/ExpandSAMs.scala b/compiler/src/dotty/tools/dotc/transform/ExpandSAMs.scala
index 4347cca7f9d9..d0e90566f333 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExpandSAMs.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExpandSAMs.scala
@@ -7,7 +7,7 @@ import Scopes.newScope
 import Contexts.*, Symbols.*, Types.*, Flags.*, Decorators.*, StdNames.*, Constants.*
 import MegaPhase.*
 import Names.TypeName
-import SymUtils.*
+
 import NullOpsDecorator.*
 import ast.untpd
 
diff --git a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
index b197d23f0b94..f57595293ae1 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
@@ -14,7 +14,7 @@ import core.StdNames.nme
 import core.Names.*
 import core.NameOps.*
 import core.NameKinds.SuperArgName
-import SymUtils.*
+
 import dotty.tools.dotc.ast.tpd
 
 import collection.mutable
diff --git a/compiler/src/dotty/tools/dotc/transform/ExplicitSelf.scala b/compiler/src/dotty/tools/dotc/transform/ExplicitSelf.scala
index cd62a55cb8dc..cc4f1e8f45b8 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExplicitSelf.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExplicitSelf.scala
@@ -3,7 +3,7 @@ package transform
 
 import core.*
 import Contexts.*, Types.*, MegaPhase.*, ast.Trees.*, Symbols.*, Decorators.*, Flags.*
-import SymUtils.*
+
 
 /** Transform references of the form
  *
diff --git a/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala b/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
index 22ca97c7129a..c75ac9982317 100644
--- a/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
+++ b/compiler/src/dotty/tools/dotc/transform/GenericSignatures.scala
@@ -14,7 +14,7 @@ import core.TypeApplications.{EtaExpansion, TypeParamInfo}
 import core.TypeErasure.{erasedGlb, erasure, fullErasure, isGenericArrayElement, tupleArity}
 import core.Types.*
 import core.classfile.ClassfileConstants
-import SymUtils.*
+
 import config.Printers.transforms
 import reporting.trace
 import java.lang.StringBuilder
@@ -272,7 +272,7 @@ object GenericSignatures {
             if (!primitiveOK) jsig(defn.ObjectType)
             else if (sym == defn.UnitClass) jsig(defn.BoxedUnitClass.typeRef)
             else builder.append(defn.typeTag(sym.info))
-          else if (ValueClasses.isDerivedValueClass(sym)) {
+          else if (sym.isDerivedValueClass) {
             val erasedUnderlying = fullErasure(tp)
             if (erasedUnderlying.isPrimitiveValueType && !primitiveOK)
               classSig(sym, pre, args)
diff --git a/compiler/src/dotty/tools/dotc/transform/Getters.scala b/compiler/src/dotty/tools/dotc/transform/Getters.scala
index eeb2e868ddc8..43289209d146 100644
--- a/compiler/src/dotty/tools/dotc/transform/Getters.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Getters.scala
@@ -9,8 +9,7 @@ import Types.*
 import Symbols.*
 import MegaPhase.*
 import Flags.*
-import ValueClasses.*
-import SymUtils.*
+
 import NameOps.*
 
 
@@ -66,7 +65,7 @@ class Getters extends MiniPhase with SymTransformer { thisPhase =>
   override def transformSym(d: SymDenotation)(using Context): SymDenotation = {
     def noGetterNeeded =
       d.isOneOf(NoGetterNeededFlags) ||
-      d.isAllOf(PrivateLocal) && !d.owner.is(Trait) && !isDerivedValueClass(d.owner) && !d.is(Lazy) ||
+      d.isAllOf(PrivateLocal) && !d.owner.is(Trait) && !d.owner.isDerivedValueClass && !d.is(Lazy) ||
       d.is(Module) && d.isStatic ||
       d.hasAnnotation(defn.ScalaStaticAnnot) ||
       d.isSelfSym
diff --git a/compiler/src/dotty/tools/dotc/transform/HoistSuperArgs.scala b/compiler/src/dotty/tools/dotc/transform/HoistSuperArgs.scala
index 190150ca8a81..96cffeb1097d 100644
--- a/compiler/src/dotty/tools/dotc/transform/HoistSuperArgs.scala
+++ b/compiler/src/dotty/tools/dotc/transform/HoistSuperArgs.scala
@@ -12,7 +12,7 @@ import core.Decorators.*
 import collection.mutable
 import ast.Trees.*
 import core.NameKinds.SuperArgName
-import SymUtils.*
+
 import core.Decorators.*
 
 object HoistSuperArgs {
diff --git a/compiler/src/dotty/tools/dotc/transform/Inlining.scala b/compiler/src/dotty/tools/dotc/transform/Inlining.scala
index a51ba93ab9ac..907fe948ac30 100644
--- a/compiler/src/dotty/tools/dotc/transform/Inlining.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Inlining.scala
@@ -5,7 +5,7 @@ import core.*
 import Flags.*
 import Contexts.*
 import Symbols.*
-import SymUtils.*
+
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.ast.Trees.*
 import dotty.tools.dotc.quoted.*
diff --git a/compiler/src/dotty/tools/dotc/transform/LambdaLift.scala b/compiler/src/dotty/tools/dotc/transform/LambdaLift.scala
index 84f90e289e43..47a280af6abc 100644
--- a/compiler/src/dotty/tools/dotc/transform/LambdaLift.scala
+++ b/compiler/src/dotty/tools/dotc/transform/LambdaLift.scala
@@ -13,7 +13,7 @@ import core.StdNames.nme
 import core.Names.*
 import core.NameOps.*
 import core.NameKinds.ExpandPrefixName
-import SymUtils.*
+
 import ExplicitOuter.outer
 import util.Store
 import collection.mutable.{HashMap, LinkedHashMap, ListBuffer}
diff --git a/compiler/src/dotty/tools/dotc/transform/LazyVals.scala b/compiler/src/dotty/tools/dotc/transform/LazyVals.scala
index 0aaecd261387..e2712a7d6302 100644
--- a/compiler/src/dotty/tools/dotc/transform/LazyVals.scala
+++ b/compiler/src/dotty/tools/dotc/transform/LazyVals.scala
@@ -16,7 +16,6 @@ import core.Types.*
 import core.{Names, StdNames}
 import dotty.tools.dotc.config.Feature
 import transform.MegaPhase.MiniPhase
-import transform.SymUtils.*
 
 import scala.collection.mutable
 import scala.compiletime.uninitialized
diff --git a/compiler/src/dotty/tools/dotc/transform/Memoize.scala b/compiler/src/dotty/tools/dotc/transform/Memoize.scala
index 120f2f66cd80..0b4d4c7dbf59 100644
--- a/compiler/src/dotty/tools/dotc/transform/Memoize.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Memoize.scala
@@ -8,7 +8,7 @@ import Phases.*
 import SymDenotations.SymDenotation
 import Denotations.*
 import Symbols.*
-import SymUtils.*
+
 import Constants.*
 import MegaPhase.*
 import NameOps.*
diff --git a/compiler/src/dotty/tools/dotc/transform/Mixin.scala b/compiler/src/dotty/tools/dotc/transform/Mixin.scala
index 33864a33a047..6df4bebde132 100644
--- a/compiler/src/dotty/tools/dotc/transform/Mixin.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Mixin.scala
@@ -6,7 +6,7 @@ import core.*
 import MegaPhase.*
 import Contexts.*
 import Flags.*
-import SymUtils.*
+
 import Symbols.*
 import SymDenotations.*
 import Types.*
diff --git a/compiler/src/dotty/tools/dotc/transform/MixinOps.scala b/compiler/src/dotty/tools/dotc/transform/MixinOps.scala
index d40a2a7eb17e..1b2d3e79c9a4 100644
--- a/compiler/src/dotty/tools/dotc/transform/MixinOps.scala
+++ b/compiler/src/dotty/tools/dotc/transform/MixinOps.scala
@@ -4,7 +4,7 @@ package transform
 import core.*
 import Symbols.*, Types.*, Contexts.*, DenotTransformers.*, Flags.*
 import util.Spans.*
-import SymUtils.*
+
 import StdNames.*, NameOps.*
 import typer.Nullables
 
diff --git a/compiler/src/dotty/tools/dotc/transform/MoveStatics.scala b/compiler/src/dotty/tools/dotc/transform/MoveStatics.scala
index a417d41ffd56..95975ad9e6b8 100644
--- a/compiler/src/dotty/tools/dotc/transform/MoveStatics.scala
+++ b/compiler/src/dotty/tools/dotc/transform/MoveStatics.scala
@@ -15,7 +15,7 @@ import NameOps.*
 
 import ast.*
 
-import SymUtils.*
+
 import MegaPhase.*
 
 /** Move static methods from companion to the class itself */
diff --git a/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala b/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
index f417e90a91e7..5201a0c905f0 100644
--- a/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala
@@ -8,7 +8,7 @@ import Symbols.*, Contexts.*, Types.*, StdNames.*, NameOps.*
 import patmat.SpaceEngine
 import util.Spans.*
 import typer.Applications.*
-import SymUtils.*
+
 import Annotations.*
 import Flags.*, Constants.*
 import Decorators.*
@@ -1022,7 +1022,7 @@ object PatternMatcher {
           case Block((_: ValDef) :: Block(_, Match(_, cases)) :: Nil, _) => cases
           case _ => Nil
         val caseThreshold =
-          if ValueClasses.isDerivedValueClass(tpt.tpe.typeSymbol) then 1
+          if tpt.tpe.typeSymbol.isDerivedValueClass then 1
           else MinSwitchCases
         def typesInPattern(pat: Tree): List[Type] = pat match
           case Alternative(pats) => pats.flatMap(typesInPattern)
diff --git a/compiler/src/dotty/tools/dotc/transform/PickleQuotes.scala b/compiler/src/dotty/tools/dotc/transform/PickleQuotes.scala
index 359b8a900664..1f51f17ab91e 100644
--- a/compiler/src/dotty/tools/dotc/transform/PickleQuotes.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PickleQuotes.scala
@@ -11,7 +11,7 @@ import Constants.*
 import ast.Trees.*
 import ast.untpd
 import ast.TreeTypeMap
-import SymUtils.*
+
 import NameKinds.*
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.ast.untpd
diff --git a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
index 23fcc80d3f22..ae714e978410 100644
--- a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
@@ -12,7 +12,7 @@ import typer.ErrorReporting.errorTree
 import Types.*, Contexts.*, Names.*, Flags.*, DenotTransformers.*, Phases.*
 import SymDenotations.*, StdNames.*, Annotations.*, Trees.*, Scopes.*
 import Decorators.*
-import Symbols.*, SymUtils.*, NameOps.*
+import Symbols.*, NameOps.*
 import ContextFunctionResults.annotateContextResults
 import config.Printers.typr
 import config.Feature
diff --git a/compiler/src/dotty/tools/dotc/transform/PruneErasedDefs.scala b/compiler/src/dotty/tools/dotc/transform/PruneErasedDefs.scala
index f0de71dfc239..9bb30926d45a 100644
--- a/compiler/src/dotty/tools/dotc/transform/PruneErasedDefs.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PruneErasedDefs.scala
@@ -10,7 +10,7 @@ import Symbols.*
 import typer.RefChecks
 import MegaPhase.MiniPhase
 import ast.tpd
-import SymUtils.*
+
 import config.Feature
 import Decorators.*
 import dotty.tools.dotc.core.Types.MethodType
diff --git a/compiler/src/dotty/tools/dotc/transform/Recheck.scala b/compiler/src/dotty/tools/dotc/transform/Recheck.scala
index be058ae3a41a..3d7b81a606ab 100644
--- a/compiler/src/dotty/tools/dotc/transform/Recheck.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Recheck.scala
@@ -4,7 +4,7 @@ package transform
 
 import core.*
 import Symbols.*, Contexts.*, Types.*, ContextOps.*, Decorators.*, SymDenotations.*
-import Flags.*, SymUtils.*, NameKinds.*, Denotations.{Denotation, SingleDenotation}
+import Flags.*, NameKinds.*, Denotations.{Denotation, SingleDenotation}
 import ast.*
 import Names.Name
 import Phases.Phase
diff --git a/compiler/src/dotty/tools/dotc/transform/ReifiedReflect.scala b/compiler/src/dotty/tools/dotc/transform/ReifiedReflect.scala
index 2fd9f923d98e..90c5ac85167c 100644
--- a/compiler/src/dotty/tools/dotc/transform/ReifiedReflect.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ReifiedReflect.scala
@@ -7,7 +7,7 @@ import Flags.*
 import Types.*
 import Contexts.*
 import Symbols.*
-import SymUtils.*
+
 import NameKinds.*
 import dotty.tools.dotc.ast.tpd
 import tpd.*
diff --git a/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala b/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
index e864178af658..dd3f41be5a8e 100644
--- a/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala
@@ -5,7 +5,7 @@ import core.*
 import MegaPhase.*
 import Contexts.*
 import Flags.*
-import SymUtils.*
+
 import Symbols.*
 import Decorators.*
 import DenotTransformers.*
diff --git a/compiler/src/dotty/tools/dotc/transform/SelectStatic.scala b/compiler/src/dotty/tools/dotc/transform/SelectStatic.scala
index 6177e5d0839d..6dc718ef526b 100644
--- a/compiler/src/dotty/tools/dotc/transform/SelectStatic.scala
+++ b/compiler/src/dotty/tools/dotc/transform/SelectStatic.scala
@@ -8,7 +8,7 @@ import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.*
 import dotty.tools.dotc.transform.MegaPhase.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 
 /** Removes `Select`s that would be compiled into `GetStatic`.
  *
diff --git a/compiler/src/dotty/tools/dotc/transform/Splicing.scala b/compiler/src/dotty/tools/dotc/transform/Splicing.scala
index 0c64a366686d..967c1cb6d19b 100644
--- a/compiler/src/dotty/tools/dotc/transform/Splicing.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Splicing.scala
@@ -11,7 +11,7 @@ import Constants.*
 import ast.Trees.*
 import ast.{TreeTypeMap, untpd}
 import util.Spans.*
-import SymUtils.*
+
 import NameKinds.*
 import dotty.tools.dotc.ast.tpd
 
diff --git a/compiler/src/dotty/tools/dotc/transform/Staging.scala b/compiler/src/dotty/tools/dotc/transform/Staging.scala
index f7fac1981fb2..a48718b2d60a 100644
--- a/compiler/src/dotty/tools/dotc/transform/Staging.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Staging.scala
@@ -10,7 +10,7 @@ import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.inlines.Inlines
 import dotty.tools.dotc.util.SrcPos
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.staging.StagingLevel.*
 import dotty.tools.dotc.staging.CrossStageSafety
 import dotty.tools.dotc.staging.HealType
diff --git a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
index 13ea452bcc9e..ce2b8fa591d8 100644
--- a/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/SuperAccessors.scala
@@ -7,7 +7,7 @@ import scala.collection.mutable
 import ValueClasses.isMethodWithExtension
 import core.*
 import Contexts.*, Flags.*, Symbols.*, Names.*, StdNames.*, NameOps.*, Trees.*
-import SymUtils.*
+
 import DenotTransformers.DenotTransformer
 import Symbols.*
 import util.Spans.*
diff --git a/compiler/src/dotty/tools/dotc/transform/SyntheticMembers.scala b/compiler/src/dotty/tools/dotc/transform/SyntheticMembers.scala
index 9d19251638db..6d2aedb9b47b 100644
--- a/compiler/src/dotty/tools/dotc/transform/SyntheticMembers.scala
+++ b/compiler/src/dotty/tools/dotc/transform/SyntheticMembers.scala
@@ -2,7 +2,7 @@ package dotty.tools.dotc
 package transform
 
 import core.*
-import Symbols.*, Types.*, Contexts.*, Names.*, StdNames.*, Constants.*, SymUtils.*
+import Symbols.*, Types.*, Contexts.*, Names.*, StdNames.*, Constants.*
 import Flags.*
 import DenotTransformers.*
 import Decorators.*
@@ -10,8 +10,7 @@ import NameOps.*
 import Annotations.Annotation
 import typer.ProtoTypes.constrained
 import ast.untpd
-import ValueClasses.isDerivedValueClass
-import SymUtils.*
+
 import util.Property
 import util.Spans.Span
 import config.Printers.derive
@@ -90,7 +89,7 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
   def caseAndValueMethods(clazz: ClassSymbol)(using Context): List[Tree] = {
     val clazzType = clazz.appliedRef
     lazy val accessors =
-      if (isDerivedValueClass(clazz)) clazz.paramAccessors.take(1) // Tail parameters can only be `erased`
+      if clazz.isDerivedValueClass then clazz.paramAccessors.take(1) // Tail parameters can only be `erased`
       else clazz.caseAccessors
     val isEnumValue = clazz.isAnonymousClass && clazz.info.parents.head.classSymbol.is(Enum)
     val isSimpleEnumValue = isEnumValue && !clazz.owner.isAllOf(EnumCase)
@@ -98,12 +97,12 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
     val isNonJavaEnumValue = isEnumValue && !isJavaEnumValue
 
     val symbolsToSynthesize: List[Symbol] =
-      if (clazz.is(Case))
-        if (clazz.is(Module)) caseModuleSymbols
+      if clazz.is(Case) then
+        if clazz.is(Module) then caseModuleSymbols
         else caseSymbols
-      else if (isNonJavaEnumValue) nonJavaEnumValueSymbols
-      else if (isEnumValue) enumValueSymbols
-      else if (isDerivedValueClass(clazz)) valueSymbols
+      else if isNonJavaEnumValue then nonJavaEnumValueSymbols
+      else if isEnumValue then enumValueSymbols
+      else if clazz.isDerivedValueClass then valueSymbols
       else Nil
 
     def syntheticDefIfMissing(sym: Symbol): List[Tree] =
diff --git a/compiler/src/dotty/tools/dotc/transform/TypeTestsCasts.scala b/compiler/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
index f8092ba51c2a..bac731c5f41b 100644
--- a/compiler/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
@@ -9,8 +9,7 @@ import Contexts.*, Symbols.*, Types.*, Constants.*, StdNames.*, Decorators.*
 import ast.untpd
 import Erasure.Boxing.*
 import TypeErasure.*
-import ValueClasses.*
-import SymUtils.*
+
 import core.Flags.*
 import util.Spans.*
 import reporting.*
@@ -218,7 +217,7 @@ object TypeTestsCasts {
             !(!testCls.isPrimitiveValueClass && foundCls.isPrimitiveValueClass) &&
                // foundCls can be `Boolean`, while testCls is `Integer`
                // it can happen in `(3: Boolean | Int).isInstanceOf[Int]`
-            !isDerivedValueClass(foundCls) && !isDerivedValueClass(testCls)
+            !foundCls.isDerivedValueClass && !testCls.isDerivedValueClass
                // we don't have the logic to handle derived value classes
 
           /** Check whether a runtime test that a value of `foundCls` can be a `testCls`
diff --git a/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala b/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
index d0c012322fce..5cdd5d8ded43 100644
--- a/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
@@ -8,19 +8,10 @@ import Contexts.*
 import Phases.*
 import Flags.*
 import StdNames.*
-import SymUtils.*
 
 /** Methods that apply to user-defined value classes */
 object ValueClasses {
 
-  def isDerivedValueClass(sym: Symbol)(using Context): Boolean = sym.isClass && {
-    val d = sym.denot
-    !d.isRefinementClass &&
-    d.isValueClass &&
-    (d.initial.symbol ne defn.AnyValClass) && // Compare the initial symbol because AnyVal does not exist after erasure
-    !d.isPrimitiveValueClass
-  }
-
   def isMethodWithExtension(sym: Symbol)(using Context): Boolean =
     val d = sym.denot.initial
     d.validFor.firstPhaseId <= extensionMethodsPhase.id
diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
index e51f9c05bd62..f3a883df9e4f 100644
--- a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
+++ b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -17,7 +17,6 @@ import typer.*
 import Applications.*
 import Inferencing.*
 import ProtoTypes.*
-import transform.SymUtils.*
 import reporting.*
 import config.Printers.{exhaustivity => debug}
 import util.{SrcPos, NoSourcePosition}
diff --git a/compiler/src/dotty/tools/dotc/transform/sjs/ExplicitJSClasses.scala b/compiler/src/dotty/tools/dotc/transform/sjs/ExplicitJSClasses.scala
index 4d27ecee12fa..853fead6f799 100644
--- a/compiler/src/dotty/tools/dotc/transform/sjs/ExplicitJSClasses.scala
+++ b/compiler/src/dotty/tools/dotc/transform/sjs/ExplicitJSClasses.scala
@@ -19,7 +19,7 @@ import core.StdNames.nme
 import core.SymDenotations.SymDenotation
 import core.Names.*
 import core.NameKinds.*
-import SymUtils.*
+
 
 import util.Store
 
diff --git a/compiler/src/dotty/tools/dotc/transform/sjs/JSSymUtils.scala b/compiler/src/dotty/tools/dotc/transform/sjs/JSSymUtils.scala
index fafa1eb3cf79..936b6958fb33 100644
--- a/compiler/src/dotty/tools/dotc/transform/sjs/JSSymUtils.scala
+++ b/compiler/src/dotty/tools/dotc/transform/sjs/JSSymUtils.scala
@@ -11,7 +11,7 @@ import Names.*
 import Phases.*
 import StdNames.*
 import Symbols.*
-import SymUtils.*
+
 import ast.Trees.*
 import Types.*
 
diff --git a/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSExports.scala b/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSExports.scala
index d7073ac2e261..dbd6e1a8f412 100644
--- a/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSExports.scala
+++ b/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSExports.scala
@@ -11,7 +11,7 @@ import Flags.*
 import NameKinds.DefaultGetterName
 import StdNames.*
 import Symbols.*
-import SymUtils.*
+
 import Types.*
 
 import util.Spans.Span
diff --git a/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSInterop.scala b/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSInterop.scala
index 2da2a98837c7..610fca869ad2 100644
--- a/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSInterop.scala
+++ b/compiler/src/dotty/tools/dotc/transform/sjs/PrepJSInterop.scala
@@ -18,7 +18,7 @@ import NameKinds.{DefaultGetterName, ModuleClassName}
 import NameOps.*
 import StdNames.*
 import Symbols.*
-import SymUtils.*
+
 import Types.*
 
 import JSSymUtils.*
diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala
index 890783374c67..004b21ce4fb5 100644
--- a/compiler/src/dotty/tools/dotc/typer/Applications.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala
@@ -21,7 +21,6 @@ import NameKinds.DefaultGetterName
 import ProtoTypes.*
 import Inferencing.*
 import reporting.*
-import transform.SymUtils.*
 import Nullables.*, NullOpsDecorator.*
 import config.Feature
 
diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala
index a56854e333fd..bbf091fe00ca 100644
--- a/compiler/src/dotty/tools/dotc/typer/Checking.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala
@@ -23,8 +23,6 @@ import util.SrcPos
 import util.Spans.Span
 import rewrites.Rewrites.patch
 import inlines.Inlines
-import transform.SymUtils.*
-import transform.ValueClasses.*
 import Decorators.*
 import ErrorReporting.{err, errorType}
 import config.Printers.{typr, patmatch}
@@ -34,6 +32,7 @@ import SymDenotations.{NoCompleter, NoDenotation}
 import Applications.unapplyArgs
 import Inferencing.isFullyDefined
 import transform.patmat.SpaceEngine.{isIrrefutable, isIrrefutableQuotePattern}
+import transform.ValueClasses.underlyingOfValueClass
 import config.Feature
 import config.Feature.sourceVersion
 import config.SourceVersion.*
@@ -709,7 +708,7 @@ object Checking {
       case _ =>
         report.error(ValueClassesMayNotContainInitalization(clazz), stat.srcPos)
     }
-    if (isDerivedValueClass(clazz)) {
+    if (clazz.isDerivedValueClass) {
       if (clazz.is(Trait))
         report.error(CannotExtendAnyVal(clazz), clazz.srcPos)
       if clazz.is(Module) then
diff --git a/compiler/src/dotty/tools/dotc/typer/CrossVersionChecks.scala b/compiler/src/dotty/tools/dotc/typer/CrossVersionChecks.scala
index 4087c5faf404..91303b00618c 100644
--- a/compiler/src/dotty/tools/dotc/typer/CrossVersionChecks.scala
+++ b/compiler/src/dotty/tools/dotc/typer/CrossVersionChecks.scala
@@ -3,7 +3,7 @@ package dotc
 package transform
 
 import core.*
-import Symbols.*, Types.*, Contexts.*, Flags.*, SymUtils.*, Decorators.*, reporting.*
+import Symbols.*, Types.*, Contexts.*, Flags.*, Decorators.*, reporting.*
 import util.SrcPos
 import config.{ScalaVersion, NoScalaVersion, Feature, ScalaRelease}
 import MegaPhase.MiniPhase
diff --git a/compiler/src/dotty/tools/dotc/typer/Dynamic.scala b/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
index 6efc84031ec7..14cc7bf963a6 100644
--- a/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Dynamic.scala
@@ -16,8 +16,8 @@ import dotty.tools.dotc.core.Decorators.*
 import dotty.tools.dotc.core.TypeErasure
 import util.Spans.*
 import core.Symbols.*
+import transform.ValueClasses
 import ErrorReporting.*
-import dotty.tools.dotc.transform.ValueClasses
 import reporting.*
 import inlines.Inlines
 
@@ -239,7 +239,7 @@ trait Dynamic {
        */
       def maybeBoxingCast(tpe: Type) =
         val maybeBoxed =
-          if ValueClasses.isDerivedValueClass(tpe.classSymbol) && qual.tpe <:< defn.ReflectSelectableTypeRef then
+          if tpe.classSymbol.isDerivedValueClass && qual.tpe <:< defn.ReflectSelectableTypeRef then
             val genericUnderlying = ValueClasses.valueClassUnbox(tpe.classSymbol.asClass)
             val underlying = tpe.select(genericUnderlying).widen.resultType
             New(tpe.widen, tree.cast(underlying) :: Nil)
diff --git a/compiler/src/dotty/tools/dotc/typer/Namer.scala b/compiler/src/dotty/tools/dotc/typer/Namer.scala
index 74c63c41ec80..0001fee9a256 100644
--- a/compiler/src/dotty/tools/dotc/typer/Namer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Namer.scala
@@ -23,7 +23,6 @@ import parsing.Parsers.Parser
 import Annotations.*
 import Inferencing.*
 import transform.ValueClasses.*
-import transform.SymUtils.*
 import TypeErasure.erasure
 import reporting.*
 import config.Feature.sourceVersion
diff --git a/compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala b/compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala
index e7284cc5a997..fb9176526e42 100644
--- a/compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala
+++ b/compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala
@@ -17,7 +17,7 @@ import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.inlines.PrepareInlineable
 import dotty.tools.dotc.quoted.QuotePatterns
 import dotty.tools.dotc.staging.StagingLevel.*
-import dotty.tools.dotc.transform.SymUtils.*
+
 import dotty.tools.dotc.typer.ErrorReporting.errorTree
 import dotty.tools.dotc.typer.Implicits.*
 import dotty.tools.dotc.typer.Inferencing.*
diff --git a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
index 3f49e78c17c1..4f0ec6a6bcdc 100644
--- a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
+++ b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
@@ -5,7 +5,7 @@ package typer
 import transform.*
 import core.*
 import Symbols.*, Types.*, Contexts.*, Flags.*, Names.*, NameOps.*, NameKinds.*
-import StdNames.*, Denotations.*, SymUtils.*, Phases.*, SymDenotations.*
+import StdNames.*, Denotations.*, Phases.*, SymDenotations.*
 import NameKinds.DefaultGetterName
 import util.Spans.*
 import scala.collection.mutable
diff --git a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
index aaebcfce690a..67853001d8f0 100644
--- a/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Synthesizer.scala
@@ -11,7 +11,6 @@ import Decorators.*
 import ProtoTypes.*
 import Inferencing.{fullyDefinedType, isFullyDefined}
 import ast.untpd
-import transform.SymUtils.*
 import transform.SyntheticMembers.*
 import util.Property
 import ast.Trees.genericEmptyTree
diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala
index be9d3343b378..9cbbbb359299 100644
--- a/compiler/src/dotty/tools/dotc/typer/Typer.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala
@@ -45,7 +45,6 @@ import config.Feature.{sourceVersion, migrateTo3}
 import config.SourceVersion.*
 import rewrites.Rewrites.patch
 import staging.StagingLevel
-import transform.SymUtils.*
 import reporting.*
 import Nullables.*
 import NullOpsDecorator.*
diff --git a/compiler/src/dotty/tools/dotc/util/Signatures.scala b/compiler/src/dotty/tools/dotc/util/Signatures.scala
index c3779d3473cf..b0583f9dfd0a 100644
--- a/compiler/src/dotty/tools/dotc/util/Signatures.scala
+++ b/compiler/src/dotty/tools/dotc/util/Signatures.scala
@@ -11,9 +11,8 @@ import core.NameOps.isUnapplyName
 import core.Names.*
 import core.NameKinds
 import core.Types.*
-import core.Symbols.NoSymbol
+import core.Symbols.{NoSymbol, isLocalToBlock}
 import interactive.Interactive
-import transform.SymUtils.isLocalToBlock
 import util.Spans.Span
 import reporting.*
 
diff --git a/compiler/src/dotty/tools/repl/Rendering.scala b/compiler/src/dotty/tools/repl/Rendering.scala
index 487b6ce3924f..517815615f2a 100644
--- a/compiler/src/dotty/tools/repl/Rendering.scala
+++ b/compiler/src/dotty/tools/repl/Rendering.scala
@@ -7,7 +7,6 @@ import dotc.*, core.*
 import Contexts.*, Denotations.*, Flags.*, NameOps.*, StdNames.*, Symbols.*
 import printing.ReplPrinter
 import reporting.Diagnostic
-import transform.ValueClasses
 import util.StackTraceOps.*
 
 import scala.compiletime.uninitialized
@@ -127,7 +126,7 @@ private[repl] class Rendering(parentClassLoader: Option[ClassLoader] = None):
    * @param value underlying value
    */
   private def rewrapValueClass(sym: Symbol, value: Object)(using Context): Option[Object] =
-    if ValueClasses.isDerivedValueClass(sym) then
+    if sym.isDerivedValueClass then
       val valueClass = Class.forName(sym.binaryClassName, true, classLoader())
       valueClass.getConstructors.headOption.map(_.newInstance(value))
     else
diff --git a/presentation-compiler/src/main/dotty/tools/pc/completions/CompletionValue.scala b/presentation-compiler/src/main/dotty/tools/pc/completions/CompletionValue.scala
index fe67f08ce43b..d267d2660776 100644
--- a/presentation-compiler/src/main/dotty/tools/pc/completions/CompletionValue.scala
+++ b/presentation-compiler/src/main/dotty/tools/pc/completions/CompletionValue.scala
@@ -7,7 +7,6 @@ import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.Symbols.Symbol
 import dotty.tools.dotc.core.Types.Type
-import dotty.tools.dotc.transform.SymUtils.*
 import dotty.tools.pc.printer.ShortenedTypePrinter
 import dotty.tools.pc.utils.MtagsEnrichments.decoded
 
diff --git a/presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala b/presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala
index ea1255c3f6cc..1e2dbb5cdaa1 100644
--- a/presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala
+++ b/presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala
@@ -26,7 +26,6 @@ import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.interactive.Completion
 import dotty.tools.dotc.interactive.Completion.Mode
-import dotty.tools.dotc.transform.SymUtils.*
 import dotty.tools.dotc.util.SourcePosition
 import dotty.tools.dotc.util.Spans
 import dotty.tools.dotc.util.Spans.Span
diff --git a/presentation-compiler/src/main/dotty/tools/pc/completions/KeywordsCompletions.scala b/presentation-compiler/src/main/dotty/tools/pc/completions/KeywordsCompletions.scala
index 0dbd9a8e4ee2..a052a0a2c8eb 100644
--- a/presentation-compiler/src/main/dotty/tools/pc/completions/KeywordsCompletions.scala
+++ b/presentation-compiler/src/main/dotty/tools/pc/completions/KeywordsCompletions.scala
@@ -11,7 +11,6 @@ import dotty.tools.dotc.ast.untpd.UntypedTreeTraverser
 import dotty.tools.dotc.core.Comments
 import dotty.tools.dotc.core.Comments.Comment
 import dotty.tools.dotc.core.Contexts.Context
-import dotty.tools.dotc.transform.SymUtils._
 import dotty.tools.dotc.util.SourcePosition
 import dotty.tools.dotc.util.Spans.Span