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

[Cherry-picked 125321e][modified]

Author: WojciechMazur

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.*

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.*
+
 
 /*
  *

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
 

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
 

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

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
 

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

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}

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

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

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.*

compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala

@@ -13,7 +13,6 @@ import Trees.*
 import typer.RefChecks.{checkAllOverrides, checkSelfAgainstParents, OverridingPairsChecker}
 import typer.Checking.{checkBounds, checkAppliedTypesIn}
 import util.{SimpleIdentitySet, EqHashMap, SrcPos}
-import transform.SymUtils.*
 import transform.{Recheck, PreRecheck}
 import Recheck.*
 import scala.collection.mutable

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 {
 

compiler/src/dotty/tools/dotc/transform/SymUtils.scala renamed to 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
@@ -369,8 +377,6 @@ object SymUtils:
       self.hasAnnotation(defn.ExperimentalAnnot)
       || isDefaultArgumentOfExperimentalMethod
       || (!self.is(Package) && self.owner.isInExperimentalScope)
-      || self.topLevelClass.ownersIterator.exists(p =>
-          p.is(Package) && p.owner.isRoot && p.name == tpnme.dotty)
 
     /** The declared self type of this class, as seen from `site`, stripping
     *  all refinements for opaque types.

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}
@@ -32,7 +31,7 @@ import util.{SourceFile, NoSource, Property, SourcePosition, SrcPos, EqHashMap}
 import scala.annotation.internal.sharable
 import config.Printers.typr
 
-object Symbols {
+object Symbols extends SymUtils {
 
   implicit def eqSymbol: CanEqual[Symbol, Symbol] = CanEqual.derived
 

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

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 =>
@@ -630,15 +630,15 @@ 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 =>
         val tycon = tp.tycon
         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)
         }

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.*

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 {
 

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}

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 cc.{adaptFunctionTypeUnderPureFuns, adaptByNameArgUnderPureFuns}
 
 import dotty.tools.tasty.{TastyBuffer, TastyReader}

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.*

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}

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

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

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

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.

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

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:

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

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

compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala

@@ -17,7 +17,7 @@ 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}

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 }

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