Merge remote-tracking branch 'upstream/main'

compiler/src/dotty/tools/dotc/transform/TypeTestsCasts.scala

@@ -56,7 +56,7 @@ object TypeTestsCasts {
    *  9. if `X` is `T1 | T2`, checkable(T1, P) && checkable(T2, P).
    *  10. otherwise, ""
    */
-  def whyUncheckable(X: Type, P: Type, span: Span)(using Context): String = atPhase(Phases.refchecksPhase.next) {
+  def whyUncheckable(X: Type, P: Type, span: Span, trustTypeApplication: Boolean)(using Context): String = atPhase(Phases.refchecksPhase.next) {
     extension (inline s1: String) inline def &&(inline s2: String): String = if s1 == "" then s2 else s1
     extension (inline b: Boolean) inline def |||(inline s: String): String = if b then "" else s
 
@@ -143,7 +143,7 @@ object TypeTestsCasts {
           case defn.ArrayOf(tpE)   => recur(tpE, tpT)
           case _                   => recur(defn.AnyType, tpT)
         }
-      case tpe @ AppliedType(tycon, targs)     =>
+      case tpe @ AppliedType(tycon, targs) if !trustTypeApplication =>
         X.widenDealias match {
           case OrType(tp1, tp2) =>
             // This case is required to retrofit type inference,
@@ -366,8 +366,7 @@ object TypeTestsCasts {
         if (sym.isTypeTest) {
           val argType = tree.args.head.tpe
           val isTrusted = tree.hasAttachment(PatternMatcher.TrustedTypeTestKey)
-          if !isTrusted then
-            checkTypePattern(expr.tpe, argType, expr.srcPos)
+          checkTypePattern(expr.tpe, argType, expr.srcPos, isTrusted)
           transformTypeTest(expr, argType,
             flagUnrelated = enclosingInlineds.isEmpty) // if test comes from inlined code, dont't flag it even if it always false
         }
@@ -392,10 +391,10 @@ object TypeTestsCasts {
   def checkBind(tree: Bind)(using Context) =
     checkTypePattern(defn.ThrowableType, tree.body.tpe, tree.srcPos)
 
-  private def checkTypePattern(exprTpe: Type, castTpe: Type, pos: SrcPos)(using Context) =
+  private def checkTypePattern(exprTpe: Type, castTpe: Type, pos: SrcPos, trustTypeApplication: Boolean = false)(using Context) =
     val isUnchecked = exprTpe.widenTermRefExpr.hasAnnotation(defn.UncheckedAnnot)
     if !isUnchecked then
-      val whyNot = whyUncheckable(exprTpe, castTpe, pos.span)
+      val whyNot = whyUncheckable(exprTpe, castTpe, pos.span, trustTypeApplication)
       if whyNot.nonEmpty then
         report.uncheckedWarning(UncheckedTypePattern(castTpe, whyNot), pos)
 

docs/_spec/01-lexical-syntax.md

@@ -137,7 +137,7 @@ Otherwise, soft keywords are treated as actual keywords in the following situati
  - `as`, if it appears in a renaming import clause.
  - `derives`, if it appears after an extension clause or after the name and possibly parameters of a class, trait, object, or enum definition.
  - `end`, if it appears at the start of a line following a statement (i.e. definition or toplevel expression) and is followed on the same line by a single non-comment token that is:
-   - one of the keywords `for`, `given`, `if`, `match`, `new`, `this`, `throw`, `try`, `val`, `while`, or
+   - one of the keywords `for`, `given`, `if`, `match`, `new`, `this`, `throw`, `try`, `val`, `while`, `extension` or
    - an identifier.
  - `extension`, if it appears at the start of a statement and is followed by `(` or `[`.
  - `inline`, if it is followed by any token that can start an expression.

tests/bench/inductive-implicits.scala

@@ -174,49 +174,49 @@ object Test extends App {
     Int ::
     Int ::
 //
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-//
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-//
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-//
-    Int ::
-    Int ::
-    Int ::
-    Int ::
-    Int ::
 //    Int ::
 //    Int ::
 //    Int ::
 //    Int ::
 //    Int ::
+//    Int ::
+//    Int ::
+//    Int ::
+//    Int ::
+//    Int ::
+// //
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+// //
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+// //
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
+//     Int ::
 // //
 //     Int ::
 //     Int ::

tests/neg/i22320.check

@@ -0,0 +1,12 @@
+-- [E008] Not Found Error: tests/neg/i22320.scala:19:19 ----------------------------------------------------------------
+19 |    val z = system.z // error
+   |            ^^^^^^^^
+   |            value z is not a member of a.System.
+   |            An extension method was tried, but could not be fully constructed:
+   |
+   |                a.z(system)
+   |
+   |                failed with:
+   |
+   |                    Found:    (system : a.System)
+   |                    Required: a.SimulatedSystem

tests/neg/i22320.scala

@@ -0,0 +1,19 @@
+package a:
+  opaque type System = Any
+  opaque type SimulatedSystem <: System = System
+
+  extension (system: System)
+    def x: BigInt = ???
+    def y: BigInt = ???
+  end extension
+
+  extension (system: SimulatedSystem)
+    def z: BigInt = ???
+  end extension
+
+package b:
+  import a.*
+  def issue(system: System) =
+    val x = system.x
+    val y = system.y
+    val z = system.z // error

tests/warn/i22051.scala

@@ -0,0 +1,17 @@
+def boundary[T](body: (T => RuntimeException) => T): T =
+  case class Break(value: T) extends RuntimeException
+  try body(Break.apply)
+  catch case Break(t) => t // warn: pattern matching on local classes is unsound currently
+
+def test =
+  boundary[Int]: EInt =>
+    val v: String = boundary[String]: EString =>
+      throw EInt(3)
+    v.length // a runtime error: java.lang.ClassCastException
+
+def boundaryCorrectBehaviour[T](body: (T => RuntimeException) => T): T =
+  object local:
+    // A correct implementation, but is still treated as a local class right now
+    case class Break(value: T) extends RuntimeException
+  try body(local.Break.apply)
+  catch case local.Break(t) => t // warn