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author | Jason Zaugg <jzaugg@gmail.com> | 2015-07-27 13:15:43 +1000 |
---|---|---|
committer | Jason Zaugg <jzaugg@gmail.com> | 2015-07-27 14:28:39 +1000 |
commit | d74a615334de70c13bd9be00b03b4010de980b0b (patch) | |
tree | c4409678573dcc8188247df4fcac91366507c5f2 | |
parent | 48ede0d254ee1ea03a51c4a53fe5e8d6ae3b335d (diff) | |
download | scala-async-d74a615334de70c13bd9be00b03b4010de980b0b.tar.gz scala-async-d74a615334de70c13bd9be00b03b4010de980b0b.tar.bz2 scala-async-d74a615334de70c13bd9be00b03b4010de980b0b.zip |
Avoid masking user exception with ??? for Nothing typed expressions
Code like:
val x = if (cond) throw new A else throw new B
Was being transformed to:
val ifRes = ???
if (cond) ifRes = throw new A else ifRes = throw new B
val x = ifRes
by way of the use of `gen.mkZero` which throws `???` if the requested type is `Nothing`
This commit special cases `Nothing` typed expressions in a similar manner to `Unit` type expressions.
The example above is now translated to:
if (cond) throw new A else throw new B
val x = throw new IllegalStateException()
Fixes #120
(cherry picked from commit 80aaf18d5111322baee73dad30eb0a81cdd62314)
3 files changed, 52 insertions, 2 deletions
diff --git a/src/main/scala/scala/async/internal/AnfTransform.scala b/src/main/scala/scala/async/internal/AnfTransform.scala index 9bc36d8..e41c64e 100644 --- a/src/main/scala/scala/async/internal/AnfTransform.scala +++ b/src/main/scala/scala/async/internal/AnfTransform.scala @@ -70,6 +70,9 @@ private[async] trait AnfTransform { val stats :+ expr = anf.transformToList(tree) def statsExprUnit = stats :+ expr :+ localTyper.typedPos(expr.pos)(Literal(Constant(()))) + def statsExprThrow = + stats :+ expr :+ localTyper.typedPos(expr.pos)(Throw(Apply(Select(New(gen.mkAttributedRef(defn.IllegalStateExceptionClass)), nme.CONSTRUCTOR), Nil))) + expr match { case Apply(fun, args) if isAwait(fun) => val valDef = defineVal(name.await, expr, tree.pos) @@ -90,6 +93,8 @@ private[async] trait AnfTransform { // but add Unit value to bring it into form expected by async transform if (expr.tpe =:= definitions.UnitTpe) { statsExprUnit + } else if (expr.tpe =:= definitions.NothingTpe) { + statsExprThrow } else { val varDef = defineVar(name.ifRes, expr.tpe, tree.pos) def branchWithAssign(orig: Tree) = localTyper.typedPos(orig.pos) { @@ -110,8 +115,9 @@ private[async] trait AnfTransform { // but add Unit value to bring it into form expected by async transform if (expr.tpe =:= definitions.UnitTpe) { statsExprUnit - } - else { + } else if (expr.tpe =:= definitions.NothingTpe) { + statsExprThrow + } else { val varDef = defineVar(name.matchRes, expr.tpe, tree.pos) def typedAssign(lhs: Tree) = localTyper.typedPos(lhs.pos)(Assign(Ident(varDef.symbol), mkAttributedCastPreservingAnnotations(lhs, varDef.symbol.tpe))) diff --git a/src/main/scala/scala/async/internal/TransformUtils.scala b/src/main/scala/scala/async/internal/TransformUtils.scala index da76c18..5b5c4d2 100644 --- a/src/main/scala/scala/async/internal/TransformUtils.scala +++ b/src/main/scala/scala/async/internal/TransformUtils.scala @@ -83,6 +83,8 @@ private[async] trait TransformUtils { val NonFatalClass = rootMirror.staticModule("scala.util.control.NonFatal") val Async_await = asyncBase.awaitMethod(global)(macroApplication.symbol).ensuring(_ != NoSymbol) + val IllegalStateExceptionClass = rootMirror.staticClass("java.lang.IllegalStateException") + } def isSafeToInline(tree: Tree) = { diff --git a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala index 757ae0b..bbc1b2b 100644 --- a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala +++ b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala @@ -405,4 +405,46 @@ class AnfTransformSpec { val applyImplicitView = tree.collect { case x if x.getClass.getName.endsWith("ApplyImplicitView") => x } applyImplicitView.map(_.toString) mustBe List("view(a$1)") } + + @Test + def nothingTypedIf(): Unit = { + import scala.async.internal.AsyncId.{async, await} + val result = util.Try(async { + if (true) { + val n = await(1) + if (n < 2) { + throw new RuntimeException("case a") + } + else { + throw new RuntimeException("case b") + } + } + else { + "case c" + } + }) + + assert(result.asInstanceOf[util.Failure[_]].exception.getMessage == "case a") + } + + @Test + def nothingTypedMatch(): Unit = { + import scala.async.internal.AsyncId.{async, await} + val result = util.Try(async { + 0 match { + case _ if "".isEmpty => + val n = await(1) + n match { + case _ if n < 2 => + throw new RuntimeException("case a") + case _ => + throw new RuntimeException("case b") + } + case _ => + "case c" + } + }) + + assert(result.asInstanceOf[util.Failure[_]].exception.getMessage == "case a") + } } |