diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala index cd33fe9cef24..224359faaf3b 100644 --- a/compiler/src/dotty/tools/dotc/typer/Applications.scala +++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala @@ -714,8 +714,8 @@ trait Applications extends Compatibility { || argMatch == ArgMatch.CompatibleCAP && { val argtpe1 = argtpe.widen - val captured = captureWildcards(argtpe1) - (captured ne argtpe1) && isCompatible(captured, formal.widenExpr) + val captured = captureWildcardsCompat(argtpe1, formal.widenExpr) + captured ne argtpe1 } /** The type of the given argument */ @@ -2412,4 +2412,9 @@ trait Applications extends Compatibility { def isApplicableExtensionMethod(methodRef: TermRef, receiverType: Type)(using Context): Boolean = methodRef.symbol.is(ExtensionMethod) && !receiverType.isBottomType && tryApplyingExtensionMethod(methodRef, nullLiteral.asInstance(receiverType)).nonEmpty + + def captureWildcardsCompat(tp: Type, pt: Type)(using Context): Type = + val captured = captureWildcards(tp) + if (captured ne tp) && isCompatible(captured, pt) then captured + else tp } diff --git a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala index d724ad1708b1..da785e32865a 100644 --- a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala +++ b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala @@ -501,15 +501,13 @@ object ProtoTypes { def checkNoWildcardCaptureForCBN(targ1: Tree)(using Context): Tree = { if hasCaptureConversionArg(targ1.tpe) then - stripCast(targ1).tpe match - case tp: AppliedType if tp.hasWildcardArg => - errorTree(targ1, - em"""argument for by-name parameter is not a value - |and contains wildcard arguments: $tp - | - |Assign it to a val and pass that instead. - |""") - case _ => targ1 + val tp = stripCast(targ1).tpe + errorTree(targ1, + em"""argument for by-name parameter is not a value + |and contains wildcard arguments: $tp + | + |Assign it to a val and pass that instead. + |""") else targ1 } diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala index e7f75eafed94..a87d6dd7e703 100644 --- a/compiler/src/dotty/tools/dotc/typer/Typer.scala +++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala @@ -3962,7 +3962,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer return adaptConstant(tree, ConstantType(converted)) case _ => - val captured = captureWildcards(wtp) + val captured = captureWildcardsCompat(wtp, pt) if (captured `ne` wtp) return readapt(tree.cast(captured)) diff --git a/tests/neg/t9419.zio-http.scala b/tests/neg/t9419.zio-http.scala new file mode 100644 index 000000000000..cff9ec51e6f9 --- /dev/null +++ b/tests/neg/t9419.zio-http.scala @@ -0,0 +1,18 @@ +// Minimisation of how the fix for t9419 affected zio-http +import java.util.concurrent.Future as JFuture + +trait Test: + def shutdownGracefully(): JFuture[_] + + def executedWildcard(jFuture: => JFuture[_]): Unit + def executedGeneric[A](jFuture: => JFuture[A]): Unit + def executedWildGen[A](jFuture: => JFuture[? <: A]): Unit + + // Even though JFuture is morally covariant, at least currently, + // there's no definition-side variance, so it's treated as invariant. + // So we have to be concerned that two different values of `JFuture[A]` + // with different types, blowing up together. So error in `fails`. + def works = executedWildcard(shutdownGracefully()) + def fails = executedGeneric(shutdownGracefully()) // error + def fixed = executedGeneric(shutdownGracefully().asInstanceOf[JFuture[Any]]) // fix + def best2 = executedWildGen(shutdownGracefully()) // even better, use use-site variance in the method diff --git a/tests/pos/t9419.specs2.scala b/tests/pos/t9419.specs2.scala new file mode 100644 index 000000000000..fe4a44312594 --- /dev/null +++ b/tests/pos/t9419.specs2.scala @@ -0,0 +1,13 @@ +// Minimisation of how the fix for t9419 affected specs2 +class MustExpectable[T](tm: () => T): + def must_==(other: => Any) = tm() == other + +class Foo + +object Main: + implicit def theValue[T](t: => T): MustExpectable[T] = new MustExpectable(() => t) + def main(args: Array[String]): Unit = + val cls = classOf[Foo] + val instance = new Foo() + val works = cls must_== cls + val fails = instance.getClass must_== cls