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-rw-r--r--bincompat-backward.whitelist.conf4
-rw-r--r--bincompat-forward.whitelist.conf4
-rw-r--r--src/reflect/scala/reflect/internal/Types.scala17
-rw-r--r--test/files/neg/t7289.check4
-rw-r--r--test/files/neg/t7289.scala39
-rw-r--r--test/files/neg/t7289_status_quo.check22
-rw-r--r--test/files/neg/t7289_status_quo.scala23
7 files changed, 106 insertions, 7 deletions
diff --git a/bincompat-backward.whitelist.conf b/bincompat-backward.whitelist.conf
index aa06e1d21c..3426dc72e1 100644
--- a/bincompat-backward.whitelist.conf
+++ b/bincompat-backward.whitelist.conf
@@ -186,6 +186,10 @@ filter {
{
matchName="scala.reflect.internal.ClassfileConstants.xxxunusedxxxx"
problemName=MissingMethodProblem
+ },
+ {
+ matchName="scala.reflect.internal.Types#TypeVar.setInst"
+ problemName=IncompatibleResultTypeProblem
}
]
}
diff --git a/bincompat-forward.whitelist.conf b/bincompat-forward.whitelist.conf
index d0893c5a28..c59d0a7dec 100644
--- a/bincompat-forward.whitelist.conf
+++ b/bincompat-forward.whitelist.conf
@@ -418,6 +418,10 @@ filter {
{
matchName="scala.reflect.internal.ClassfileConstants.CONSTANT_METHODTYPE"
problemName=MissingMethodProblem
+ },
+ {
+ matchName="scala.reflect.internal.Types#TypeVar.setInst"
+ problemName=IncompatibleResultTypeProblem
}
]
}
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index a2c9f1fadf..ee584bed2c 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -3076,12 +3076,14 @@ trait Types extends api.Types { self: SymbolTable =>
/** The variable's skolemization level */
val level = skolemizationLevel
- /** Two occurrences of a higher-kinded typevar, e.g. `?CC[Int]` and `?CC[String]`, correspond to
- * ''two instances'' of `TypeVar` that share the ''same'' `TypeConstraint`.
+ /** Applies this TypeVar to type arguments, if arity matches.
*
- * `constr` for `?CC` only tracks type constructors anyway,
- * so when `?CC[Int] <:< List[Int]` and `?CC[String] <:< Iterable[String]`
- * `?CC's` hibounds contains List and Iterable.
+ * Different applications of the same type constructor variable `?CC`,
+ * e.g. `?CC[Int]` and `?CC[String]`, are modeled as distinct instances of `TypeVar`
+ * that share a `TypeConstraint`, so that the comparisons `?CC[Int] <:< List[Int]`
+ * and `?CC[String] <:< Iterable[String]` result in `?CC` being upper-bounded by `List` and `Iterable`.
+ *
+ * Applying the wrong number of type args results in a TypeVar whose instance is set to `ErrorType`.
*/
def applyArgs(newArgs: List[Type]): TypeVar = (
if (newArgs.isEmpty && typeArgs.isEmpty)
@@ -3091,7 +3093,7 @@ trait Types extends api.Types { self: SymbolTable =>
TypeVar.trace("applyArgs", "In " + originLocation + ", apply args " + newArgs.mkString(", ") + " to " + originName)(tv)
}
else
- throw new Error("Invalid type application in TypeVar: " + params + ", " + newArgs)
+ TypeVar(typeSymbol).setInst(ErrorType)
)
// newArgs.length may differ from args.length (could've been empty before)
//
@@ -3121,13 +3123,14 @@ trait Types extends api.Types { self: SymbolTable =>
// <region name="constraint mutators + undoLog">
// invariant: before mutating constr, save old state in undoLog
// (undoLog is used to reset constraints to avoid piling up unrelated ones)
- def setInst(tp: Type) {
+ def setInst(tp: Type): this.type = {
// assert(!(tp containsTp this), this)
undoLog record this
// if we were compared against later typeskolems, repack the existential,
// because skolems are only compatible if they were created at the same level
val res = if (shouldRepackType) repackExistential(tp) else tp
constr.inst = TypeVar.trace("setInst", "In " + originLocation + ", " + originName + "=" + res)(res)
+ this
}
def addLoBound(tp: Type, isNumericBound: Boolean = false) {
diff --git a/test/files/neg/t7289.check b/test/files/neg/t7289.check
new file mode 100644
index 0000000000..e4aeebbc6c
--- /dev/null
+++ b/test/files/neg/t7289.check
@@ -0,0 +1,4 @@
+t7289.scala:8: error: could not find implicit value for parameter e: Test.Schtroumpf[scala.collection.immutable.Nil.type]
+ implicitly[Schtroumpf[Nil.type]]
+ ^
+one error found
diff --git a/test/files/neg/t7289.scala b/test/files/neg/t7289.scala
new file mode 100644
index 0000000000..f4ed3daf76
--- /dev/null
+++ b/test/files/neg/t7289.scala
@@ -0,0 +1,39 @@
+object Test extends App {
+ trait Schtroumpf[T]
+
+ implicit def schtroumpf[T, U <: Coll[T], Coll[X] <: Traversable[X]]
+ (implicit minorSchtroumpf: Schtroumpf[T]): Schtroumpf[U] = ???
+
+ implicit val qoo: Schtroumpf[Int] = new Schtroumpf[Int]{}
+ implicitly[Schtroumpf[Nil.type]]
+}
+
+/*
+info1 = {scala.tools.nsc.typechecker.Implicits$ImplicitInfo@3468}"qoo: => Test.Schtroumpf[Int]"
+info2 = {scala.tools.nsc.typechecker.Implicits$ImplicitInfo@3469}"schtroumpf: [T, U <: Coll[T], Coll[_] <: Traversable[_]](implicit minorSchtroumpf: Test.Schtroumpf[T])Test.Schtroumpf[U]"
+isStrictlyMoreSpecific(info1, info2)
+ isSubType(Test.Schtroumpf[Int], Test.Schtroumpf[U] forSome { T; U <: Coll[T]; Coll[_] <: Traversable[_] })
+ isAsSpecificValueType(Test.Schtroumpf[Int], Test.Schtroumpf[U], undef2 = List(type T, type U, type Coll))
+
+ val et: ExistentialType = Test.Schtroumpf[U] forSome { T; U <: Coll[T]; Coll[_] <: Traversable[_] }
+ val tp1 = Test.Schtroumpf[Int]
+ et.withTypeVars(isSubType(tp1, _, depth))
+ solve()
+ tvars = tList(=?Nothing, =?Int, =?=?Int)
+
+
+[ create] ?T ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ create] ?U ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ create] ?Coll ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ setInst] Nothing ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], T=Nothing )
+[ setInst] scala.collection.immutable.Nil.type( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], U=scala.collection.immutable.Nil.type )
+[ setInst] =?scala.collection.immutable.Nil.type( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], Coll==?scala.collection.immutable.Nil.type )
+[ create] ?T ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ setInst] Int ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], T=Int )
+[ create] ?T ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ create] ?U ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ create] ?Coll ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]] )
+[ setInst] Nothing ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], T=Nothing )
+[ setInst] Int ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], U=Int )
+[ setInst] =?Int ( In Test#schtroumpf[T,U <: Coll[T],Coll[_] <: Traversable[_]], Coll==?Int )
+*/ \ No newline at end of file
diff --git a/test/files/neg/t7289_status_quo.check b/test/files/neg/t7289_status_quo.check
new file mode 100644
index 0000000000..31c072e969
--- /dev/null
+++ b/test/files/neg/t7289_status_quo.check
@@ -0,0 +1,22 @@
+t7289_status_quo.scala:9: error: could not find implicit value for parameter e: Test1.Ext[List[Int]]
+ implicitly[Ext[List[Int]]] // fails - not found
+ ^
+t7289_status_quo.scala:11: error: could not find implicit value for parameter e: Test1.Ext[List[List[List[Int]]]]
+ implicitly[Ext[List[List[List[Int]]]]] // fails - not found
+ ^
+t7289_status_quo.scala:15: error: ambiguous implicit values:
+ both method f in object Test1 of type [A, Coll <: CC[A], CC[X] <: Traversable[X]](implicit xi: Test1.Ext[A])Test1.Ext[Coll]
+ and value m in object Test1 of type => Test1.Ext[List[List[Int]]]
+ match expected type Test1.Ext[_ <: List[List[Int]]]
+ implicitly[Ext[_ <: List[List[Int]]]] // fails - ambiguous
+ ^
+t7289_status_quo.scala:20: error: could not find implicit value for parameter e: Test1.ExtCov[List[Int]]
+ implicitly[ExtCov[List[Int]]] // fails - not found
+ ^
+t7289_status_quo.scala:21: error: could not find implicit value for parameter e: Test1.ExtCov[List[List[Int]]]
+ implicitly[ExtCov[List[List[Int]]]] // fails - not found
+ ^
+t7289_status_quo.scala:22: error: could not find implicit value for parameter e: Test1.ExtCov[List[List[List[Int]]]]
+ implicitly[ExtCov[List[List[List[Int]]]]] // fails - not found
+ ^
+6 errors found
diff --git a/test/files/neg/t7289_status_quo.scala b/test/files/neg/t7289_status_quo.scala
new file mode 100644
index 0000000000..39621429a1
--- /dev/null
+++ b/test/files/neg/t7289_status_quo.scala
@@ -0,0 +1,23 @@
+// record the status quo after this fix
+// not clear to @adriaanm why an upper-bounded existential in an invariant position
+// is different from putting that upper bound in a covariant position
+object Test1 {
+ trait Ext[T]
+ implicit def f[A, Coll <: CC[A], CC[X] <: Traversable[X]](implicit xi: Ext[A]): Ext[Coll] = ???
+ implicit val m: Ext[List[List[Int]]] = new Ext[List[List[Int]]]{}
+
+ implicitly[Ext[List[Int]]] // fails - not found
+ implicitly[Ext[List[List[Int]]]] // compiles
+ implicitly[Ext[List[List[List[Int]]]]] // fails - not found
+
+ // Making Ext[+T] should incur the same behavior as these. (so says @paulp)
+ implicitly[Ext[_ <: List[Int]]] // compiles
+ implicitly[Ext[_ <: List[List[Int]]]] // fails - ambiguous
+ implicitly[Ext[_ <: List[List[List[Int]]]]] // compiles
+
+ // But, we currently get:
+ trait ExtCov[+T]
+ implicitly[ExtCov[List[Int]]] // fails - not found
+ implicitly[ExtCov[List[List[Int]]]] // fails - not found
+ implicitly[ExtCov[List[List[List[Int]]]]] // fails - not found
+} \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-22 13:58:07 +0000