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| author | Adriaan Moors <adriaan.moors@typesafe.com> | 2013-01-10 14:43:00 -0800 |
|---|---|---|
| committer | Adriaan Moors <adriaan.moors@typesafe.com> | 2013-01-10 16:04:57 -0800 |
| commit | 8475807f540a698c8456bc113b9c5b9186ee2cf5 (patch) | |
| tree | bc0b734a95c90484a9252c24df2df951589bfcc0 | |
| parent | f219ade08ed8174c7bded654e8070f4b61843513 (diff) | |
| download | scala-8475807f540a698c8456bc113b9c5b9186ee2cf5.tar.gz scala-8475807f540a698c8456bc113b9c5b9186ee2cf5.tar.bz2 scala-8475807f540a698c8456bc113b9c5b9186ee2cf5.zip | |
SI-6955 switch emission no longer foiled by type alias
dealias the type of the scrutinee before checking it's switchable
now with tests! (using IcodeTest since javap is not available everywhere)
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala | 2 | ||||
| -rw-r--r-- | test/files/run/t6955.check | 1 | ||||
| -rw-r--r-- | test/files/run/t6955.scala | 26 |
3 files changed, 28 insertions, 1 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index fa8aff5cdd..044201b1d7 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -3527,7 +3527,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL override def emitSwitch(scrut: Tree, scrutSym: Symbol, cases: List[List[TreeMaker]], pt: Type, matchFailGenOverride: Option[Tree => Tree], unchecked: Boolean): Option[Tree] = { import CODE._ val regularSwitchMaker = new RegularSwitchMaker(scrutSym, matchFailGenOverride, unchecked) // TODO: if patterns allow switch but the type of the scrutinee doesn't, cast (type-test) the scrutinee to the corresponding switchable type and switch on the result - if (regularSwitchMaker.switchableTpe(scrutSym.tpe)) { + if (regularSwitchMaker.switchableTpe(scrutSym.tpe.dealias)) { // TODO: switch to dealiasWiden in 2.11 val caseDefsWithDefault = regularSwitchMaker(cases map {c => (scrutSym, c)}, pt) if (caseDefsWithDefault isEmpty) None // not worth emitting a switch. else { diff --git a/test/files/run/t6955.check b/test/files/run/t6955.check new file mode 100644 index 0000000000..0cfbf08886 --- /dev/null +++ b/test/files/run/t6955.check @@ -0,0 +1 @@ +2 diff --git a/test/files/run/t6955.scala b/test/files/run/t6955.scala new file mode 100644 index 0000000000..2610acdec4 --- /dev/null +++ b/test/files/run/t6955.scala @@ -0,0 +1,26 @@ +import scala.tools.partest.IcodeTest + +class Switches { + type Tag = Byte + + def switchBad(i: Tag): Int = i match { // notice type of i is Tag = Byte + case 1 => 1 + case 2 => 2 + case 3 => 3 + case _ => 0 + } + + def switchOkay(i: Byte): Int = i match { // notice type of i is Byte + case 1 => 1 + case 2 => 2 + case 3 => 3 + case _ => 0 + } +} + +object Test extends IcodeTest { + // ensure we get two switches out of this -- ignore the rest of the output for robustness + // exclude the constant we emit for the "SWITCH ..." string below (we get the icode for all the code you see in this file) + override def show() = println(collectIcode("").filter(x => x.indexOf("SWITCH ...") >= 0 && x.indexOf("CONSTANT(") == -1).size) +} + |