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author | Jason Zaugg <jzaugg@gmail.com> | 2015-07-27 13:15:43 +1000 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2015-07-27 13:15:43 +1000 |
commit | 80aaf18d5111322baee73dad30eb0a81cdd62314 (patch) | |
tree | 9b2f5219aca829a2f5d756bab5e196f99b120653 /src/main | |
parent | 017928c43a6520c136d30af08d2bc3f441c2088a (diff) | |
download | scala-async-80aaf18d5111322baee73dad30eb0a81cdd62314.tar.gz scala-async-80aaf18d5111322baee73dad30eb0a81cdd62314.tar.bz2 scala-async-80aaf18d5111322baee73dad30eb0a81cdd62314.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
Diffstat (limited to 'src/main')
-rw-r--r-- | src/main/scala/scala/async/internal/AnfTransform.scala | 9 | ||||
-rw-r--r-- | src/main/scala/scala/async/internal/TransformUtils.scala | 1 |
2 files changed, 8 insertions, 2 deletions
diff --git a/src/main/scala/scala/async/internal/AnfTransform.scala b/src/main/scala/scala/async/internal/AnfTransform.scala index 585f388..55e164b 100644 --- a/src/main/scala/scala/async/internal/AnfTransform.scala +++ b/src/main/scala/scala/async/internal/AnfTransform.scala @@ -48,6 +48,8 @@ private[async] trait AnfTransform { val stats :+ expr = anf.transformToList(tree) def statsExprUnit = stats :+ expr :+ api.typecheck(atPos(expr.pos)(Literal(Constant(())))) + def statsExprThrow = + stats :+ expr :+ api.typecheck(atPos(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) @@ -68,6 +70,8 @@ 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) = api.typecheck(atPos(orig.pos) { @@ -88,8 +92,9 @@ 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) = api.typecheck(atPos(lhs.pos)(Assign(Ident(varDef.symbol), mkAttributedCastPreservingAnnotations(lhs, tpe(varDef.symbol))))) diff --git a/src/main/scala/scala/async/internal/TransformUtils.scala b/src/main/scala/scala/async/internal/TransformUtils.scala index df958b8..547f980 100644 --- a/src/main/scala/scala/async/internal/TransformUtils.scala +++ b/src/main/scala/scala/async/internal/TransformUtils.scala @@ -151,6 +151,7 @@ private[async] trait TransformUtils { val NonFatalClass = rootMirror.staticModule("scala.util.control.NonFatal") val Async_await = asyncBase.awaitMethod(c.universe)(c.macroApplication.symbol).ensuring(_ != NoSymbol) + val IllegalStateExceptionClass = rootMirror.staticClass("java.lang.IllegalStateException") } // `while(await(x))` ... or `do { await(x); ... } while(...)` contain an `If` that loops; |