Merge pull request #15281 from dotty-staging/fix-15227

Fix hash code of ExprImpl and TypeImpl

compiler/src/scala/quoted/runtime/impl/ExprImpl.scala

@@ -19,5 +19,7 @@ final class ExprImpl(val tree: tpd.Tree, val scope: Scope) extends Expr[Any] {
     case _ => false
   }
 
+  override def hashCode(): Int = tree.hashCode()
+
   override def toString: String = "'{ ... }"
 }

compiler/src/scala/quoted/runtime/impl/TypeImpl.scala

@@ -13,5 +13,7 @@ final class TypeImpl(val typeTree: tpd.Tree, val scope: Scope) extends Type[?] {
     case _ => false
   }
 
+  override def hashCode(): Int = typeTree.hashCode()
+
   override def toString: String = "Type.of[...]"
 }

tests/pos-macros/i15227a/Macro_1.scala

@@ -0,0 +1,15 @@
+import scala.quoted.*
+
+inline def mac[T](inline expr: T): T =
+  ${ impl('expr) }
+
+def impl[T: Type](expr: Expr[T])(using Quotes): Expr[T] = {
+  import quotes.reflect.*
+  val expr2 = expr.asTerm.asExpr
+
+  assert(expr == expr2)
+  assert(expr.hashCode() == expr2.hashCode())
+
+  expr
+
+}

tests/pos-macros/i15227a/Test_2.scala

@@ -0,0 +1,2 @@
+@main def test =
+  mac(1)

tests/pos-macros/i15227b/Macro_1.scala

@@ -0,0 +1,27 @@
+import scala.quoted.*
+
+inline def mac[T](inline expr: T): T =
+  ${ impl('expr) }
+
+class MyMap() extends ExprMap {
+  var expressions: List[Expr[Any]] = Nil
+
+  override def transform[T](e: Expr[T])(using Type[T])(using q: Quotes): Expr[T] =
+    expressions ::= e
+    transformChildren(e)
+
+}
+
+def impl[T: Type](expr: Expr[T])(using Quotes): Expr[T] = {
+
+  val List(es1, es2) = List(MyMap(), MyMap()).map { m =>
+    m.transform(expr)
+    m.expressions
+  }
+
+  assert(es1 == es2)
+  assert(es1.map(_.hashCode()) == es2.map(_.hashCode()), s"hash codes not equal:\n${es1.map(_.hashCode())}\n${es2.map(_.hashCode())}")
+
+  expr
+
+}

tests/pos-macros/i15227b/Test_2.scala

@@ -0,0 +1,2 @@
+@main def test =
+  mac(1)