From 55c9b9c280ac9bc36bbac09397c7646f8dcf4583 Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Thu, 31 Jan 2013 00:33:19 +0100 Subject: SI-6146 More accurate prefixes for sealed subtypes. When analysing exhaustivity/reachability of type tests and equality tests, the pattern matcher must construct a set of sealed subtypes based on the prefix of the static type of and the set of sealed descendent symbols of that type. Previously, it was using `memberType` for this purpose. In simple cases, this is sufficient: scala> class C { class I1; object O { class I2 } }; object D extends C defined class C defined module D scala> typeOf[D.type] memberType typeOf[C#I1].typeSymbol res0: u.Type = D.I1 But, as reported in this bug, it fails when there is an additional level of nesting: scala> typeOf[D.type] memberType typeOf[c.O.I2 forSome { val c: C }].typeSymbol res5: u.Type = C.O.I2 This commit introduces `nestedMemberType`, which uses `memberType` recursively up the prefix chain prefix chain. scala> nestedMemberType(typeOf[c.O.I2 forSome { val c: C }].typeSymbol, typeOf[D.type], typeOf[C].typeSymbol) res6: u.Type = D.O.Id --- test/files/pos/t6146.flags | 1 + test/files/pos/t6146.scala | 60 +++++++++++++++++++++++++++++++++++++++++++++ test/files/run/t6146b.check | 52 +++++++++++++++++++++++++++++++++++++++ test/files/run/t6146b.scala | 39 +++++++++++++++++++++++++++++ 4 files changed, 152 insertions(+) create mode 100644 test/files/pos/t6146.flags create mode 100644 test/files/pos/t6146.scala create mode 100644 test/files/run/t6146b.check create mode 100644 test/files/run/t6146b.scala (limited to 'test') diff --git a/test/files/pos/t6146.flags b/test/files/pos/t6146.flags new file mode 100644 index 0000000000..e8fb65d50c --- /dev/null +++ b/test/files/pos/t6146.flags @@ -0,0 +1 @@ +-Xfatal-warnings \ No newline at end of file diff --git a/test/files/pos/t6146.scala b/test/files/pos/t6146.scala new file mode 100644 index 0000000000..b5bde826b1 --- /dev/null +++ b/test/files/pos/t6146.scala @@ -0,0 +1,60 @@ +// No unreachable or exhaustiveness warnings, please. + +// +// The reported bug +// + +trait AxisCompanion { + sealed trait Format + object Format { + case object Decimal extends Format + case object Integer extends Format + // Gives an unrelated warning: The outer reference in this type test cannot be checked at run time. + //final case class Time( hours: Boolean = false, millis: Boolean = true ) extends Format + } +} +object Axis extends AxisCompanion +class Axis { + import Axis._ + def test( f: Format ) = f match { + case Format.Integer => "Int" + // case Format.Time( hours, millis ) => "Time" + case Format.Decimal => "Dec" + } +} + + +// +// Some tricksier variations +// + +trait T1[X] { + trait T2[Y] { + sealed trait Format + object Format { + case object Decimal extends Format + case object Integer extends Format + } + } +} + +object O1 extends T1[Any] { + object O2 extends T2[Any] { + + } +} + +case object Shorty extends O1.O2.Format + +class Test1 { + import O1.O2._ + val FI: Format.Integer.type = Format.Integer + def test( f: Format ) = { + val ff: f.type = f + ff match { + case FI => "Int" + case Format.Decimal => "Dec" + case Shorty => "Sho" + } + } +} diff --git a/test/files/run/t6146b.check b/test/files/run/t6146b.check new file mode 100644 index 0000000000..b664d1152a --- /dev/null +++ b/test/files/run/t6146b.check @@ -0,0 +1,52 @@ +Type in expressions to have them evaluated. +Type :help for more information. + +scala> :power +** Power User mode enabled - BEEP WHIR GYVE ** +** :phase has been set to 'typer'. ** +** scala.tools.nsc._ has been imported ** +** global._, definitions._ also imported ** +** Try :help, :vals, power. ** + +scala> val u = rootMirror.universe; import u._, language._ +u: $r.intp.global.type = +import u._ +import language._ + +scala> val S1 = typeOf[c.X.S1.type forSome { val c: C[_] }].typeSymbol.tpeHK +S1: u.Type = C.X.S1.type + +scala> val S2 = typeOf[O.S2].typeSymbol.tpeHK +S2: u.Type = C.this.S2 + +scala> val S3 = typeOf[O.S3].typeSymbol.tpeHK +S3: u.Type = O.S3 + +scala> val S4 = typeOf[S4].typeSymbol.tpeHK +S4: u.Type = S4 + +scala> val F = typeOf[c.F[_] forSome { val c: C[_] }].typeSymbol.tpeHK +F: u.Type = C.this.F + +scala> val fTpe = typeOf[O.type].decl(newTermName("foo")).paramss.head.head.tpe +fTpe: u.Type = O.F[Int] + +scala> def memType(sub: Type, scrut: Type): Type = + nestedMemberType(sub.typeSymbol, scrut.prefix, scrut.typeSymbol.owner) +memType: (sub: u.Type, scrut: u.Type)u.Type + +scala> + +scala> memType(S1, fTpe) +res0: u.Type = O.X.S1.type + +scala> memType(S2, fTpe) +res1: u.Type = O.S2 + +scala> memType(S3, fTpe) +res2: u.Type = O.S3 + +scala> memType(S4, fTpe) +res3: u.Type = S4 + +scala> diff --git a/test/files/run/t6146b.scala b/test/files/run/t6146b.scala new file mode 100644 index 0000000000..adcd40d2ee --- /dev/null +++ b/test/files/run/t6146b.scala @@ -0,0 +1,39 @@ +import scala.tools.partest.ReplTest + +class A { + sealed trait F[A] +} + +class C[T] extends A { + sealed trait F[A] + object X { + object S1 extends F[T] + } + class S2 extends F[T] +} +object O extends C[Int] { + def foo(f: F[Int]) = f match { case X.S1 => } + + class S3 extends F[Int] +} +class S4 extends O.F[String] + +object Test extends ReplTest { + override def code = """ +:power +val u = rootMirror.universe; import u._, language._ +val S1 = typeOf[c.X.S1.type forSome { val c: C[_] }].typeSymbol.tpeHK +val S2 = typeOf[O.S2].typeSymbol.tpeHK +val S3 = typeOf[O.S3].typeSymbol.tpeHK +val S4 = typeOf[S4].typeSymbol.tpeHK +val F = typeOf[c.F[_] forSome { val c: C[_] }].typeSymbol.tpeHK +val fTpe = typeOf[O.type].decl(newTermName("foo")).paramss.head.head.tpe +def memType(sub: Type, scrut: Type): Type = + nestedMemberType(sub.typeSymbol, scrut.prefix, scrut.typeSymbol.owner) + +memType(S1, fTpe) +memType(S2, fTpe) +memType(S3, fTpe) +memType(S4, fTpe) + """.stripMargin.trim +} \ No newline at end of file -- cgit v1.2.3