From 48f6cdda26d23c563511caaf6842691b2cf5d23e Mon Sep 17 00:00:00 2001 From: Adriaan Moors Date: Tue, 11 Feb 2014 11:31:01 -0800 Subject: Revert "SI-1786 incorporate defined bounds in inference" Have to revert because the stricter bounds that it inferred break e.g., slick. (Backstop for that added as pos/t1786-counter.scala, as minimized by Jason) Worse, the fix was compilation order-dependent. There's a less invasive fix (SI-6169) that could be generalized in `sharpenQuantifierBounds` (used in `skolemizeExistential`), but I'd rather not mess with existentials at this point. This reverts commit e28c3edda4dd405ed382227d2a688b799bf33c72. Conflicts: src/compiler/scala/tools/nsc/typechecker/Typers.scala test/files/pos/t1786.scala --- .../scala/tools/nsc/typechecker/Typers.scala | 22 +++------- test/files/pos/t1786-counter.scala | 38 +++++++++++++++++ test/files/pos/t1786.scala | 19 --------- test/files/pos/t5459.scala | 48 ---------------------- test/pending/pos/t1786.scala | 27 ++++++++++++ test/pending/pos/t5459.scala | 48 ++++++++++++++++++++++ 6 files changed, 119 insertions(+), 83 deletions(-) create mode 100644 test/files/pos/t1786-counter.scala delete mode 100644 test/files/pos/t1786.scala delete mode 100644 test/files/pos/t5459.scala create mode 100644 test/pending/pos/t1786.scala create mode 100644 test/pending/pos/t5459.scala 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/files/pos/t1786.scala deleted file mode 100644 index 32d6c06f6e..0000000000 --- a/test/files/pos/t1786.scala +++ /dev/null @@ -1,19 +0,0 @@ -class SomeClass(val intValue:Int) -class MyClass[T <: SomeClass](val myValue:T) -class Flooz[A >: Null <: SomeClass, T >: Null <: A](var value: T) - -class A { - def f1(i:MyClass[_]) = i.myValue.intValue - def f2(i:MyClass[_ <: SomeClass]) = i.myValue.intValue - // def f3[T](i: MyClass[T]) = i.myValue.intValue - def f4[T <: SomeClass](i: MyClass[T]) = i.myValue.intValue - // def f5[T >: Null](i: MyClass[T]) = i.myValue.intValue - // def f6[T >: Null <: String](i: MyClass[T]) = i.myValue.intValue + i.myValue.charAt(0) - - // def g1[A, T](x: Flooz[A, T]) = { x.value = null ; x.value.intValue } - def g2(x: Flooz[_, _]) = { x.value = null ; x.value.intValue } - - class MyClass2(x: MyClass[_]) { val p = x.myValue.intValue } - // class MyClass3[T <: String](x: MyClass[T]) { val p = x.myValue.intValue + x.myValue.length } - // class MyClass4[T >: Null](x: MyClass[T]) { val p = x.myValue.intValue } -} diff --git a/test/files/pos/t5459.scala b/test/files/pos/t5459.scala deleted file mode 100644 index 971e6f896d..0000000000 --- a/test/files/pos/t5459.scala +++ /dev/null @@ -1,48 +0,0 @@ -trait A1 -trait A2 -trait A3 -trait L1 extends A1 with A2 with A3 - -object Test { - trait T1[-A <: A1] - trait T2[-A >: L1] - trait T3[ A <: A1] - trait T4[ A >: L1] - trait T5[+A <: A1] - trait T6[+A >: L1] - - def f1(x: T1[_]) = x - def f2(x: T2[_]) = x - def f3(x: T3[_]) = x - def f4(x: T4[_]) = x - def f5(x: T5[_]) = x - def f6(x: T6[_]) = x - // a.scala:22: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] - // def f5(x: T5[_]) = x - // ^ - - def g1(x: T1[_ <: A1]) = x - def g2(x: T2[_ >: L1]) = x - def g3(x: T3[_ <: A1]) = x - def g4(x: T4[_ >: L1]) = x - def g5(x: T5[_ <: A1]) = x - def g6(x: T6[_ >: L1]) = x - - def q1(x: T1[_ >: L1]) = x - def q2(x: T2[_ <: A1]) = x - def q3(x: T3[_ >: L1]) = x - def q4(x: T4[_ <: A1]) = x - def q5(x: T5[_ >: L1]) = x - def q6(x: T6[_ <: A1]) = x - // a.scala:41: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] - // def q5(x: T5[_ >: L1]) = x - // ^ - // two errors found - - def h1(x: T1[_ >: L1 <: A1]) = x - def h2(x: T2[_ >: L1 <: A1]) = x - def h3(x: T3[_ >: L1 <: A1]) = x - def h4(x: T4[_ >: L1 <: A1]) = x - def h5(x: T5[_ >: L1 <: A1]) = x - def h6(x: T6[_ >: L1 <: A1]) = x -} diff --git a/test/pending/pos/t1786.scala b/test/pending/pos/t1786.scala new file mode 100644 index 0000000000..6299eb9eae --- /dev/null +++ b/test/pending/pos/t1786.scala @@ -0,0 +1,27 @@ +/** 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) + +class A { + def f1(i:MyClass[_]) = i.myValue.intValue + def f2(i:MyClass[_ <: SomeClass]) = i.myValue.intValue + // def f3[T](i: MyClass[T]) = i.myValue.intValue + def f4[T <: SomeClass](i: MyClass[T]) = i.myValue.intValue + // def f5[T >: Null](i: MyClass[T]) = i.myValue.intValue + // def f6[T >: Null <: String](i: MyClass[T]) = i.myValue.intValue + i.myValue.charAt(0) + + // def g1[A, T](x: Flooz[A, T]) = { x.value = null ; x.value.intValue } + def g2(x: Flooz[_, _]) = { x.value = null ; x.value.intValue } + + class MyClass2(x: MyClass[_]) { val p = x.myValue.intValue } + // class MyClass3[T <: String](x: MyClass[T]) { val p = x.myValue.intValue + x.myValue.length } + // class MyClass4[T >: Null](x: MyClass[T]) { val p = x.myValue.intValue } +} diff --git a/test/pending/pos/t5459.scala b/test/pending/pos/t5459.scala new file mode 100644 index 0000000000..971e6f896d --- /dev/null +++ b/test/pending/pos/t5459.scala @@ -0,0 +1,48 @@ +trait A1 +trait A2 +trait A3 +trait L1 extends A1 with A2 with A3 + +object Test { + trait T1[-A <: A1] + trait T2[-A >: L1] + trait T3[ A <: A1] + trait T4[ A >: L1] + trait T5[+A <: A1] + trait T6[+A >: L1] + + def f1(x: T1[_]) = x + def f2(x: T2[_]) = x + def f3(x: T3[_]) = x + def f4(x: T4[_]) = x + def f5(x: T5[_]) = x + def f6(x: T6[_]) = x + // a.scala:22: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] + // def f5(x: T5[_]) = x + // ^ + + def g1(x: T1[_ <: A1]) = x + def g2(x: T2[_ >: L1]) = x + def g3(x: T3[_ <: A1]) = x + def g4(x: T4[_ >: L1]) = x + def g5(x: T5[_ <: A1]) = x + def g6(x: T6[_ >: L1]) = x + + def q1(x: T1[_ >: L1]) = x + def q2(x: T2[_ <: A1]) = x + def q3(x: T3[_ >: L1]) = x + def q4(x: T4[_ <: A1]) = x + def q5(x: T5[_ >: L1]) = x + def q6(x: T6[_ <: A1]) = x + // a.scala:41: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] + // def q5(x: T5[_ >: L1]) = x + // ^ + // two errors found + + def h1(x: T1[_ >: L1 <: A1]) = x + def h2(x: T2[_ >: L1 <: A1]) = x + def h3(x: T3[_ >: L1 <: A1]) = x + def h4(x: T4[_ >: L1 <: A1]) = x + def h5(x: T5[_ >: L1 <: A1]) = x + def h6(x: T6[_ >: L1 <: A1]) = x +} -- cgit v1.2.3