Merge pull request #10449 from dotty-staging/fix-#10415

Fix #10415: Use `CanEqual` instead of `Eql` for multiversal equality

Author: bishabosha

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

@@ -842,8 +842,10 @@ class Definitions {
 
   @tu lazy val TastyReflectionClass: ClassSymbol = requiredClass("scala.tasty.Reflection")
 
-  @tu lazy val EqlClass: ClassSymbol = requiredClass("scala.Eql")
-    def Eql_eqlAny(using Context): TermSymbol = EqlClass.companionModule.requiredMethod(nme.eqlAny)
+  @tu lazy val CanEqualClass: ClassSymbol = getClassIfDefined("scala.Eql").orElse(requiredClass("scala.CanEqual")).asClass
+    def CanEqual_canEqualAny(using Context): TermSymbol =
+      val methodName = if CanEqualClass.name == tpnme.Eql then nme.eqlAny else nme.canEqualAny
+      CanEqualClass.companionModule.requiredMethod(methodName)
 
   @tu lazy val TypeBoxClass: ClassSymbol = requiredClass("scala.runtime.TypeBox")
     @tu lazy val TypeBox_CAP: TypeSymbol = TypeBoxClass.requiredType(tpnme.CAP)

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

@@ -71,7 +71,7 @@ import collection.mutable.ListBuffer
  */
 object Denotations {
 
-  implicit def eqDenotation: Eql[Denotation, Denotation] = Eql.derived
+  implicit def eqDenotation: CanEqual[Denotation, Denotation] = CanEqual.derived
 
   /** A PreDenotation represents a group of single denotations or a single multi-denotation
    *  It is used as an optimization to avoid forming MultiDenotations too eagerly.

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

@@ -32,7 +32,7 @@ object Names {
    *  in a name table. A derived term name adds a tag, and possibly a number
    *  or a further simple name to some other name.
    */
-  abstract class Name extends Designator, Showable derives Eql {
+  abstract class Name extends Designator, Showable derives CanEqual {
 
     /** A type for names of the same kind as this name */
     type ThisName <: Name

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

@@ -362,6 +362,7 @@ object StdNames {
     val CAP: N                  = "CAP"
     val Constant: N             = "Constant"
     val ConstantType: N         = "ConstantType"
+    val Eql: N                  = "Eql"
     val EnumValue: N            = "EnumValue"
     val ExistentialTypeTree: N  = "ExistentialTypeTree"
     val Flag : N                = "Flag"
@@ -432,6 +433,7 @@ object StdNames {
     val bundle: N               = "bundle"
     val bytes: N                = "bytes"
     val canEqual_ : N           = "canEqual"
+    val canEqualAny : N         = "canEqualAny"
     val cbnArg: N               = "<cbn-arg>"
     val checkInitialized: N     = "checkInitialized"
     val ClassManifestFactory: N = "ClassManifestFactory"

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

@@ -37,7 +37,7 @@ import config.Printers.typr
 
 object Symbols {
 
-  implicit def eqSymbol: Eql[Symbol, Symbol] = Eql.derived
+  implicit def eqSymbol: CanEqual[Symbol, Symbol] = CanEqual.derived
 
   /** Tree attachment containing the identifiers in a tree as a sorted array */
   val Ids: Property.Key[Array[String]] = new Property.Key

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

@@ -46,7 +46,7 @@ object Types {
 
   @sharable private var nextId = 0
 
-  implicit def eqType: Eql[Type, Type] = Eql.derived
+  implicit def eqType: CanEqual[Type, Type] = CanEqual.derived
 
   /** Main class representing types.
    *

compiler/src/dotty/tools/dotc/semanticdb/Language.scala

@@ -2,7 +2,7 @@ package dotty.tools.dotc.semanticdb
 
 import dotty.tools.dotc.semanticdb.internal._
 
-sealed trait Language(val value: Int) extends SemanticdbEnum derives Eql
+sealed trait Language(val value: Int) extends SemanticdbEnum derives CanEqual
 
 object Language {
 

compiler/src/dotty/tools/dotc/semanticdb/Range.scala

@@ -12,7 +12,7 @@ final case class Range(
   startCharacter: Int,
   endLine: Int,
   endCharacter: Int
-) extends SemanticdbMessage[Range] derives Eql {
+) extends SemanticdbMessage[Range] derives CanEqual {
   @sharable
   private var __serializedSizeCachedValue: Int = 0
   private def __computeSerializedValue(): Int = {

compiler/src/dotty/tools/dotc/semanticdb/Scala3.scala

@@ -25,7 +25,7 @@ object Scala3:
 
   private val WILDCARDTypeName = nme.WILDCARD.toTypeName
 
-  enum SymbolKind derives Eql:
+  enum SymbolKind derives CanEqual:
     kind =>
 
     case Val, Var, Setter, Abstract

compiler/src/dotty/tools/dotc/semanticdb/Schema.scala

@@ -2,7 +2,7 @@ package dotty.tools.dotc.semanticdb
 
 import dotty.tools.dotc.semanticdb.internal._
 
-sealed trait Schema(val value: Int) extends SemanticdbEnum derives Eql
+sealed trait Schema(val value: Int) extends SemanticdbEnum derives CanEqual
 
 object Schema {