Merge pull request #582 from tgodzik/revert

Revert "Merge pull request #275 from scala/backport-lts-3.3-22604"

Author: tgodzik

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -801,6 +801,7 @@ object SpaceEngine {
   }
 
   private def exhaustivityCheckable(sel: Tree)(using Context): Boolean = {
+    val seen = collection.mutable.Set.empty[Symbol]
 
     // Possible to check everything, but be compatible with scalac by default
     def isCheckable(tp: Type): Boolean =
@@ -815,7 +816,10 @@ object SpaceEngine {
       }) ||
       tpw.isRef(defn.BooleanClass) ||
       classSym.isAllOf(JavaEnumTrait) ||
-      classSym.is(Case)
+      classSym.is(Case) && {
+        if seen.add(classSym) then productSelectorTypes(tpw, sel.srcPos).exists(isCheckable(_))
+        else true // recursive case class: return true and other members can still fail the check
+      }
 
     !sel.tpe.hasAnnotation(defn.UncheckedAnnot)
     && {

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -1298,30 +1298,29 @@ trait Implicits:
             if alt1.isExtension then
               // Fall back: if both results are extension method applications,
               // compare the extension methods instead of their wrappers.
-              def stripExtension(alt: SearchSuccess) =
-                methPart(stripApply(alt.tree)).tpe: @unchecked match { case ref: TermRef => ref }
-              val ref1 = stripExtension(alt1)
-              val ref2 = stripExtension(alt2)
-              // ref1 and ref2 might refer to type variables owned by
-              // alt1.tstate and alt2.tstate respectively, to compare the
-              // alternatives correctly we need a TyperState that includes
-              // constraints from both sides, see
-              // tests/*/extension-specificity2.scala for test cases.
-              val constraintsIn1 = alt1.tstate.constraint ne ctx.typerState.constraint
-              val constraintsIn2 = alt2.tstate.constraint ne ctx.typerState.constraint
-              def exploreState(alt: SearchSuccess): TyperState =
-                alt.tstate.fresh(committable = false)
-              val comparisonState =
-                if constraintsIn1 && constraintsIn2 then
-                  exploreState(alt1).mergeConstraintWith(alt2.tstate)
-                else if constraintsIn1 then
-                  exploreState(alt1)
-                else if constraintsIn2 then
-                  exploreState(alt2)
-                else
-                  ctx.typerState
-
-              diff = inContext(ctx.withTyperState(comparisonState)):
+              def stripExtension(alt: SearchSuccess) = methPart(stripApply(alt.tree)).tpe
+              ((stripExtension(alt1), stripExtension(alt2)) : @unchecked)  match
+                case (ref1: TermRef, ref2: TermRef) =>
+                  // ref1 and ref2 might refer to type variables owned by
+                  // alt1.tstate and alt2.tstate respectively, to compare the
+                  // alternatives correctly we need a TyperState that includes
+                  // constraints from both sides, see
+                  // tests/*/extension-specificity2.scala for test cases.
+                  val constraintsIn1 = alt1.tstate.constraint ne ctx.typerState.constraint
+                  val constraintsIn2 = alt2.tstate.constraint ne ctx.typerState.constraint
+                  def exploreState(alt: SearchSuccess): TyperState =
+                    alt.tstate.fresh(committable = false)
+                  val comparisonState =
+                    if constraintsIn1 && constraintsIn2 then
+                      exploreState(alt1).mergeConstraintWith(alt2.tstate)
+                    else if constraintsIn1 then
+                      exploreState(alt1)
+                    else if constraintsIn2 then
+                      exploreState(alt2)
+                    else
+                      ctx.typerState
+
+                  diff = inContext(ctx.withTyperState(comparisonState)):
                     compare(ref1, ref2)
             else // alt1 is a conversion, prefer extension alt2 over it
               diff = -1

scaladoc/src/dotty/tools/scaladoc/site/templates.scala

@@ -102,9 +102,11 @@ case class TemplateFile(
       ctx.layouts.getOrElse(name, throw new RuntimeException(s"No layouts named $name in ${ctx.layouts}"))
     )
 
-    def asJavaElement(o: Any): Any = o match
-      case m: Map[?, ?] => m.transform { (k, v) => asJavaElement(v) }.asJava
-      case l: List[?] => l.map(asJavaElement).asJava
+    def asJavaElement(o: Object): Object = o match
+      case m: Map[_, _] => m.transform {
+        case (k: String, v: Object) => asJavaElement(v)
+      }.asJava
+      case l: List[_] => l.map(x => asJavaElement(x.asInstanceOf[Object])).asJava
       case other => other
 
     // Library requires mutable maps..

tests/pos/switches.scala

@@ -42,7 +42,6 @@ class Test {
     case IntAnyVal(100) => 2
     case IntAnyVal(1000) => 3
     case IntAnyVal(10000) => 4
-    case _ => -1
   }
 }
 

tests/warn/t10373.scala renamed to tests/pos/t10373.scala

@@ -1,4 +1,4 @@
-//> using options -deprecation -feature
+//> using options -Xfatal-warnings -deprecation -feature
 
 abstract class Foo {
   def bar(): Unit = this match {
@@ -7,7 +7,7 @@ abstract class Foo {
                     // Works fine
   }
 
-  def baz(that: Foo): Unit = (this, that) match { // warn: match may not be exhaustive.
+  def baz(that: Foo): Unit = (this, that) match {
     case (Foo_1(), _) => //do something
     case (Foo_2(), _) => //do something
                          // match may not be exhaustive

tests/warn/i15662.scala

@@ -5,7 +5,6 @@ case class Composite[T](v: T)
 def m(composite: Composite[?]): Unit =
   composite match {
     case Composite[Int](v) => println(v)  // warn: cannot be checked at runtime
-    case _ => println("OTHER")
   }
 
 def m2(composite: Composite[?]): Unit =

tests/warn/i21218.scala

@@ -6,6 +6,5 @@ def Test[U, A](thisElem: A, thatElem: U) = {
       case (`passedEnd`, r: U @unchecked) => (thisElem, r)
       case (l: A @unchecked, `passedEnd`) => (l, thatElem)
       case t: (A, U) @unchecked           => t // false-positive warning
-      case (t1, t2) => (t1, t2)
     }
 }

tests/warn/i22590.arity2.scala

@@ -13,10 +13,8 @@ def Test[T] =
     case _: C => ???   // ok
   C() match
     case _: O.T => ???  // warn
-    case _ => ???
   C() match
     case _: T => ???   // warn
-    case _ => ???
 
   (??? : Any) match
     case _: List[O.T] => ???  // warn