diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 22 | ||||
| -rw-r--r-- | test/files/pos/t1786-counter.scala | 38 | ||||
| -rw-r--r-- | test/pending/pos/t1786.scala (renamed from test/files/pos/t1786.scala) | 8 | ||||
| -rw-r--r-- | test/pending/pos/t5459.scala (renamed from test/files/pos/t5459.scala) | 0 |
4 files changed, 52 insertions, 16 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 088aa5216a..1a53fef4aa 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -4891,23 +4891,13 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper asym setInfo logResult(s"Updating bounds of ${asym.fullLocationString} in $tree from '$abounds' to")(TypeBounds(lo, hi)) } if (asym != null && asym.isAbstractType) { - // See pos/t1786 to follow what's happening here. - def canEnhanceIdent = ( - asym.hasCompleteInfo - && tparam.exists /* sometimes it is NoSymbol */ - && tparam.hasCompleteInfo /* SI-2940 */ - && !tparam.isFBounded /* SI-2251 */ - && !tparam.isHigherOrderTypeParameter - && !(abounds.hi <:< tbounds.hi) - && asym.isSynthetic /* this limits us to placeholder tparams, excluding named ones */ - ) arg match { - case Bind(_, _) => enhanceBounds() - // TODO: consolidate fixes for SI-6169 and SI-1786 by dropping the Ident case, - // in favor of doing sharpenQuantifierBounds for all ExistentialTypes, not just java-defined ones - // (need to figure out how to sharpen the bounds on creation without running into cycles) - case Ident(name) if canEnhanceIdent => enhanceBounds() - case _ => + // I removed the Ident() case that partially fixed SI-1786, + // because the stricter bounds being inferred broke e.g., slick + // worse, the fix was compilation order-dependent + // sharpenQuantifierBounds (used in skolemizeExistential) has an alternative fix (SI-6169) that's less invasive + case Bind(_, _) => enhanceBounds() + case _ => } } } diff --git a/test/files/pos/t1786-counter.scala b/test/files/pos/t1786-counter.scala new file mode 100644 index 0000000000..c1ad2c204f --- /dev/null +++ b/test/files/pos/t1786-counter.scala @@ -0,0 +1,38 @@ +trait ShapeLevel + +object Fail { + abstract class ProductNodeShape[Level <: ShapeLevel, C, M <: C, U <: C, P <: C] extends Shape[Level, M, U, P] { + def copy(shapes: Seq[Shape[_, _, _, _]]): Shape[Level, _, _, _] + } + + abstract class Shape[Level <: ShapeLevel, -Mixed_, Unpacked_, Packed_] + + final class TupleShape[Level <: ShapeLevel, M <: Product, U <: Product, P <: Product](val shapes: Shape[_, _, _, _]*) extends ProductNodeShape[Level, Product, M, U, P] { + def copy(shapes: Seq[Shape[_, _, _, _]]): Shape[Level, _, _, _] = ??? + } + + trait ShapeLevel +} + +object Ok { + abstract class Shape[Level <: ShapeLevel, -Mixed_, Unpacked_, Packed_] + + abstract class ProductNodeShape[Level <: ShapeLevel, C, M <: C, U <: C, P <: C] extends Shape[Level, M, U, P] { + def copy(shapes: Seq[Shape[_, _, _, _]]): Shape[Level, _, _, _] + } + + final class TupleShape[Level <: ShapeLevel, M <: Product, U <: Product, P <: Product](val shapes: Shape[_, _, _, _]*) extends ProductNodeShape[Level, Product, M, U, P] { + def copy(shapes: Seq[Shape[_, _, _, _]]): Shape[Level, _, _, _] = ??? + } +} + +// This is why we reverted the fix for SI-1786 -- see SI-6169 for a potential alternative that could be extended to cover this. +// both objects type check on 2.10.3, but only Ok was accepted by 2.11 after the original fix to SI-1786. +// Fail results in: +/* +t1786-counter.scala:10: error: class TupleShape needs to be abstract, since method copy in class ProductNodeShape of type (shapes: Seq[Fail.Shape[_, _, _, _]])Fail.Shape[Level, _, _, _] is not defined +(Note that Seq[Fail.Shape[_, _, _, _]] does not match Seq[Fail.Shape[_ <: Fail.ShapeLevel, _, _, _]]: their type parameters differ) + final class TupleShape[Level <: ShapeLevel, M <: Product, U <: Product, P <: Product](val shapes: Shape[_, _, _, _]*) extends ProductNodeShape[Level, Product, M, U, P] { + ^ +one error found +*/
\ No newline at end of file diff --git a/test/files/pos/t1786.scala b/test/pending/pos/t1786.scala index 32d6c06f6e..6299eb9eae 100644 --- a/test/files/pos/t1786.scala +++ b/test/pending/pos/t1786.scala @@ -1,3 +1,11 @@ +/** This a consequence of the current type checking algorithm, where bounds are checked only after variables are instantiated. + * I believe this will change once we go to contraint-based type inference. + * Alternatively, we can pursue a more extensive fix to SI-6169 + * + * The below code shows a compiler flaw in that the wildcard "_" as value for a bounded type parameter either + * breaks the boundary - as it result in Any - or doesn't evaluate to the boundary (as I'd hoped it to be). +*/ + class SomeClass(val intValue:Int) class MyClass[T <: SomeClass](val myValue:T) class Flooz[A >: Null <: SomeClass, T >: Null <: A](var value: T) diff --git a/test/files/pos/t5459.scala b/test/pending/pos/t5459.scala index 971e6f896d..971e6f896d 100644 --- a/test/files/pos/t5459.scala +++ b/test/pending/pos/t5459.scala |