diff options
-rw-r--r-- | src/reflect/scala/reflect/internal/Types.scala | 24 | ||||
-rw-r--r-- | src/reflect/scala/reflect/internal/tpe/TypeConstraints.scala | 8 | ||||
-rw-r--r-- | test/files/neg/names-defaults-neg.check | 2 | ||||
-rw-r--r-- | test/files/neg/t8237-default.check | 13 | ||||
-rw-r--r-- | test/files/neg/t8237-default.scala | 29 | ||||
-rw-r--r-- | test/files/pos/t8237.scala | 29 | ||||
-rw-r--r-- | test/files/pos/t8237b.scala | 10 | ||||
-rw-r--r-- | test/files/run/t7319.check | 2 |
8 files changed, 110 insertions, 7 deletions
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala index 53c528a2bb..ba7efc94a6 100644 --- a/src/reflect/scala/reflect/internal/Types.scala +++ b/src/reflect/scala/reflect/internal/Types.scala @@ -2905,6 +2905,8 @@ trait Types override def params: List[Symbol] = zippedArgs map (_._1) override def typeArgs: List[Type] = zippedArgs map (_._2) + + override def safeToString: String = super.safeToString + typeArgs.map(_.safeToString).mkString("[", ", ", "]") } trait UntouchableTypeVar extends TypeVar { @@ -3025,15 +3027,19 @@ trait Types def addLoBound(tp: Type, isNumericBound: Boolean = false) { assert(tp != this, tp) // implies there is a cycle somewhere (?) //println("addLoBound: "+(safeToString, debugString(tp))) //DEBUG - undoLog record this - constr.addLoBound(tp, isNumericBound) + if (!sharesConstraints(tp)) { + undoLog record this + constr.addLoBound(tp, isNumericBound) + } } def addHiBound(tp: Type, isNumericBound: Boolean = false) { // assert(tp != this) //println("addHiBound: "+(safeToString, debugString(tp))) //DEBUG - undoLog record this - constr.addHiBound(tp, isNumericBound) + if (!sharesConstraints(tp)) { + undoLog record this + constr.addHiBound(tp, isNumericBound) + } } // </region> @@ -3045,6 +3051,16 @@ trait Types case ConstantTrue => true case tv: TypeVar => tv.suspended } + + /** `AppliedTypeVar`s share the same `TypeConstraint` with the `HKTypeVar` that it was spawned from. + * A type inference session can also have more than one ATV. + * If we don't detect that, we end up with "cyclic constraint" when we try to instantiate type parameters + * after solving in, pos/t8237 + */ + protected final def sharesConstraints(other: Type): Boolean = other match { + case other: TypeVar => constr == other.constr // SI-8237 avoid cycles. Details in pos/t8237.scala + case _ => false + } private[Types] def suspended_=(b: Boolean): Unit = _suspended = if (b) ConstantTrue else ConstantFalse // SI-7785 Link the suspended attribute of a TypeVar created in, say, a TypeMap (e.g. AsSeenFrom) to its originator private[Types] def linkSuspended(origin: TypeVar): Unit = _suspended = origin diff --git a/src/reflect/scala/reflect/internal/tpe/TypeConstraints.scala b/src/reflect/scala/reflect/internal/tpe/TypeConstraints.scala index e2159d30f5..564cbb1ce3 100644 --- a/src/reflect/scala/reflect/internal/tpe/TypeConstraints.scala +++ b/src/reflect/scala/reflect/internal/tpe/TypeConstraints.scala @@ -257,6 +257,12 @@ private[internal] trait TypeConstraints { // println("solving "+tvars+"/"+tparams+"/"+(tparams map (_.info))) foreach3(tvars, tparams, variances)(solveOne) - tvars forall (tv => tv.instWithinBounds || util.andFalse(log(s"Inferred type for ${tv.originString} does not conform to bounds: ${tv.constr}"))) + + def logBounds(tv: TypeVar) = log { + val what = if (!tv.instValid) "is invalid" else s"does not conform to bounds: ${tv.constr}" + s"Inferred type for ${tv.originString} (${tv.inst}) $what" + } + + tvars forall (tv => tv.instWithinBounds || util.andFalse(logBounds(tv))) } } diff --git a/test/files/neg/names-defaults-neg.check b/test/files/neg/names-defaults-neg.check index 880ddc4327..20ddd55f1f 100644 --- a/test/files/neg/names-defaults-neg.check +++ b/test/files/neg/names-defaults-neg.check @@ -88,7 +88,7 @@ names-defaults-neg.scala:76: error: no type parameters for method test4: (x: T[T --- because --- argument expression's type is not compatible with formal parameter type; found : List[Int] - required: ?T + required: ?T[?T[List[?T[X forSome { type X }]]]] Error occurred in an application involving default arguments. test4() ^ diff --git a/test/files/neg/t8237-default.check b/test/files/neg/t8237-default.check new file mode 100644 index 0000000000..59fe21ed03 --- /dev/null +++ b/test/files/neg/t8237-default.check @@ -0,0 +1,13 @@ +t8237-default.scala:5: error: no type parameters for method test4: (x: T[T[List[T[X forSome { type X }]]]])Nothing exist so that it can be applied to arguments (List[Int]) + --- because --- +argument expression's type is not compatible with formal parameter type; + found : List[Int] + required: ?T[?T[List[?T[X forSome { type X }]]]] + test4(test4$default$1) + ^ +t8237-default.scala:5: error: type mismatch; + found : List[Int] + required: T[T[List[T[X forSome { type X }]]]] + test4(test4$default$1) + ^ +two errors found diff --git a/test/files/neg/t8237-default.scala b/test/files/neg/t8237-default.scala new file mode 100644 index 0000000000..f695aa523f --- /dev/null +++ b/test/files/neg/t8237-default.scala @@ -0,0 +1,29 @@ +// This test case was extracte from `names-defaults-neg.scala` +// It pinpoints an improvement an error message that results from +// a type inference failure +object Test extends App { + test4(test4$default$1) + + def test4[T[P]](x: T[T[List[T[X forSome { type X }]]]]) = ??? + def test4$default$1[T[P]]: List[Int] = ??? +} + +/* +OLD: + no type parameters for method test4: (x: T[T[List[T[X forSome { type X }]]]])Nothing exist so that it can be applied to arguments (List[Int]) + --- because --- +argument expression's type is not compatible with formal parameter type; + found : List[Int] + required: ?T + test4(test4$default$1) + ^ + +NEW: + +no type parameters for method test4: (x: T[T[List[T[X forSome { type X }]]]])Nothing exist so that it can be applied to arguments (List[Int]) + --- because --- +argument expression's type is not compatible with formal parameter type; + found : List[Int] + required: ?T[?T[List[?T[X forSome { type X }]]] + test4(test4$default$1) +*/ diff --git a/test/files/pos/t8237.scala b/test/files/pos/t8237.scala new file mode 100644 index 0000000000..005089079e --- /dev/null +++ b/test/files/pos/t8237.scala @@ -0,0 +1,29 @@ +import scala.language.higherKinds + +object TestExplicit { + trait TC[A] + def fTt[A,E[X] <: List[X]](a: A)(implicit tt: TC[E[A]]) = a + implicit def tc[T]: TC[T] = ??? + + // Typechecking results in SOE in TypeVar.isGround + fTt(1)(tc) + // fun = TestExplicit.this.fTt[Int, E](1) + // args = TestExplicit.this.tc[E[Int]] + // argTpes.head.instantiateTypeParams = TC[?E#1[Int]] + // formals.head.instantiateTypeParams = TC[?E#2[Int]] + // (where ?E#1 and ?E#2 as distinct AppliedTypeVars that resulted + // from separate applications of type args to the same HKTypeVar, ?E) + // + // As we check if the argument conforms to the formal, we would have + // AppliedTypeVars sharing the same TypeConstraints on the LHS and RHS, + // which leads to a cyclic constraint. +} + +object TestImplicit { + trait TC[A] + def fTt[A,E[X] <: List[X]](a: A)(implicit tt: TC[E[A]]) = a + implicit def tc[T]: TC[T] = ??? + + // Oddly enough, this one works. + fTt(1) +} diff --git a/test/files/pos/t8237b.scala b/test/files/pos/t8237b.scala new file mode 100644 index 0000000000..52bb310e8b --- /dev/null +++ b/test/files/pos/t8237b.scala @@ -0,0 +1,10 @@ +import scala.language.higherKinds +import scala.reflect.runtime.universe._ +object Test { + + def fTt[A,E[X]<:List[X]](a: A)(implicit tt: TypeTag[E[A]]) = a + + trait TC[A] + implicit def TCListInt[A]: TC[A] = ??? + fTt(1) +} diff --git a/test/files/run/t7319.check b/test/files/run/t7319.check index d03ee3a6cf..b7443aa0c4 100644 --- a/test/files/run/t7319.check +++ b/test/files/run/t7319.check @@ -21,7 +21,7 @@ scala> convert(Some[Int](0)) --- because --- argument expression's type is not compatible with formal parameter type; found : Some[Int] - required: ?F forSome { type _$1 <: ?F forSome { type _$2 } } + required: ?F[_$1] forSome { type _$1 <: ?F[_$2] forSome { type _$2 } } convert(Some[Int](0)) ^ <console>:12: error: type mismatch; |