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| author | Guillaume Martres <smarter@ubuntu.com> | 2016-02-06 00:51:20 +0100 |
|---|---|---|
| committer | Guillaume Martres <smarter@ubuntu.com> | 2016-02-06 01:21:49 +0100 |
| commit | 534e4ad9f6ef1dfb767adc89c9544484cab4f48a (patch) | |
| tree | 8a7a24b5fe18abc4917a32790a1ef0b7fa247abc | |
| parent | 2c08c72a7f9b968e1f659d1d3d811f3166524983 (diff) | |
| download | dotty-534e4ad9f6ef1dfb767adc89c9544484cab4f48a.tar.gz dotty-534e4ad9f6ef1dfb767adc89c9544484cab4f48a.tar.bz2 dotty-534e4ad9f6ef1dfb767adc89c9544484cab4f48a.zip | |
Fix #1044: handle TypevarsMissContext mode in wildApprox
When `wildApprox` encounters a PolyParam it approximates it by its
bounds in the current constraint set, but this is incorrect if
`TypevarsMissContext` is set, we might get the bounds of another use of
this `PolyType`. This is exactly what happened in i1044.scala where the
implicit view `refArrayOps` needs to be used twice with two different
type parameters.
The fix is to approximate a PolyParam by its original bounds in its
PolyType if `TypevarsMissContext` is set.
This fix was inspired by the approach of #1054.
| -rw-r--r-- | src/dotty/tools/dotc/typer/Implicits.scala | 2 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/typer/ProtoTypes.scala | 14 | ||||
| -rw-r--r-- | tests/pos/i1044.scala | 3 |
3 files changed, 14 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/typer/Implicits.scala b/src/dotty/tools/dotc/typer/Implicits.scala index 280cc40e9..6cb1f1271 100644 --- a/src/dotty/tools/dotc/typer/Implicits.scala +++ b/src/dotty/tools/dotc/typer/Implicits.scala @@ -52,6 +52,8 @@ object Implicits { mt.paramTypes.length != 1 || !(argType relaxed_<:< mt.paramTypes.head)(ctx.fresh.setExploreTyperState) case poly: PolyType => + // We do not need to call ProtoTypes#constrained on `poly` because + // `refMatches` is always called with mode TypevarsMissContext enabled. poly.resultType match { case mt: MethodType => mt.isImplicit || diff --git a/src/dotty/tools/dotc/typer/ProtoTypes.scala b/src/dotty/tools/dotc/typer/ProtoTypes.scala index db196f0c2..8a758bcc8 100644 --- a/src/dotty/tools/dotc/typer/ProtoTypes.scala +++ b/src/dotty/tools/dotc/typer/ProtoTypes.scala @@ -391,11 +391,15 @@ object ProtoTypes { case tp: TypeAlias => // default case, inlined for speed tp.derivedTypeAlias(wildApprox(tp.alias, theMap)) case tp @ PolyParam(poly, pnum) => - ctx.typerState.constraint.entry(tp) match { - case bounds: TypeBounds => wildApprox(WildcardType(bounds)) - case NoType => WildcardType(wildApprox(poly.paramBounds(pnum)).bounds) - case inst => wildApprox(inst) - } + def unconstrainedApprox = WildcardType(wildApprox(poly.paramBounds(pnum)).bounds) + if (ctx.mode.is(Mode.TypevarsMissContext)) + unconstrainedApprox + else + ctx.typerState.constraint.entry(tp) match { + case bounds: TypeBounds => wildApprox(WildcardType(bounds)) + case NoType => unconstrainedApprox + case inst => wildApprox(inst) + } case MethodParam(mt, pnum) => WildcardType(TypeBounds.upper(wildApprox(mt.paramTypes(pnum)))) case tp: TypeVar => diff --git a/tests/pos/i1044.scala b/tests/pos/i1044.scala new file mode 100644 index 000000000..a984dbd67 --- /dev/null +++ b/tests/pos/i1044.scala @@ -0,0 +1,3 @@ +object Test { + val x = ???.getClass.getMethods.head.getParameterTypes.mkString(",") +} |