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author | Jason Zaugg <jzaugg@gmail.com> | 2014-02-07 11:52:55 +0100 |
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committer | Adriaan Moors <adriaan.moors@typesafe.com> | 2014-02-12 18:05:00 -0800 |
commit | f62e280825422c1e64c2427bc5958869662701ca (patch) | |
tree | f61e5c455851ee50f2210a898c15d6437724a3d6 /src/reflect | |
parent | 9c4a6e3ed7624892f46948c1c0fb57d7d5b3346e (diff) | |
download | scala-f62e280825422c1e64c2427bc5958869662701ca.tar.gz scala-f62e280825422c1e64c2427bc5958869662701ca.tar.bz2 scala-f62e280825422c1e64c2427bc5958869662701ca.zip |
SI-8244 Fix raw type regression under separate compilation
In #1901, handling of raw types encountered in signatures during class
file parsing was changed to work in the same manner as
`classExistentialType`, by using
`existentialAbstraction(cls.tparms, cls.tpe_*)`
But this never creates fresh existential symbols, and just sticks
the class type parameters it `quantified`:
scala> trait T[A <: String]
defined trait T
scala> val cls = typeOf[T[_]].typeSymbol
cls = trait T#101864
scala> cls.typeParams
res0 = List(type A#101865)
scala> cls.tpe_*
res1 = T#101864[A#101865]
scala> classExistentialType(cls)
res3 = T#101864[_ <: String#7209]
scala> val ExistentialType(quantified, result) = res3
List(type A#101865)
In the enclosed test case, this class type parameter was substituted
during `typeOf[X] memberType sym`, which led us unsoundly thinking
that `Raw[_]` was `Raw[X]`.
I've added a TODO comment to review the other usages of
`classExistentialType`.
Test variations include joint and separate compilation, and the
corresponding Scala-only code. All fail with type errors now,
as we expect. I've also added a distillation of a bootstrap
error that failed when I forgot to wrap the `existentialType`.
Diffstat (limited to 'src/reflect')
-rw-r--r-- | src/reflect/scala/reflect/internal/Definitions.scala | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala index 78e639fdff..645d6aa4ff 100644 --- a/src/reflect/scala/reflect/internal/Definitions.scala +++ b/src/reflect/scala/reflect/internal/Definitions.scala @@ -898,12 +898,15 @@ trait Definitions extends api.StandardDefinitions { * * C[E1, ..., En] forSome { E1 >: LB1 <: UB1 ... en >: LBn <: UBn }. */ + // TODO Review the way this is used. I see two potential problems: + // 1. `existentialAbstraction` here doesn't create fresh existential type symbols, it just + // uses the class type parameter symbols directly as the list of quantified symbols. + // See SI-8244 for the trouble that this can cause. + // Compare with callers of `typeParamsToExistentials` (used in Java raw type handling) + // 2. Why don't we require a prefix? Could its omission lead to wrong results in CheckabilityChecker? def classExistentialType(clazz: Symbol): Type = existentialAbstraction(clazz.typeParams, clazz.tpe_*) - def unsafeClassExistentialType(clazz: Symbol): Type = - existentialAbstraction(clazz.unsafeTypeParams, clazz.tpe_*) - // members of class scala.Any // TODO these aren't final! They are now overriden in AnyRef/Object. Prior to the fix |