diff options
Diffstat (limited to 'src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala')
| -rw-r--r-- | src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala index 017c8d24fd..e02e02d975 100644 --- a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala +++ b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala @@ -9,6 +9,8 @@ import scala.tools.nsc.plugins._ import scala.tools.nsc.ast._ +import scala.collection.mutable.ListBuffer + /** * In methods marked @cps, explicitly name results of calls to other @cps methods */ @@ -46,10 +48,20 @@ abstract class SelectiveANFTransform extends PluginComponent with Transform with // this would cause infinite recursion. But we could remove the // ValDef case here. - case dd @ DefDef(mods, name, tparams, vparamss, tpt, rhs) => + case dd @ DefDef(mods, name, tparams, vparamss, tpt, rhs0) => debuglog("transforming " + dd.symbol) atOwner(dd.symbol) { + val tailReturns = ListBuffer[Int]() + val rhs = removeTailReturn(rhs0, tailReturns) + // throw an error if there is a Return tree which is not in tail position + rhs0 foreach { + case r @ Return(_) => + if (!tailReturns.contains(r.id)) + unit.error(r.pos, "return expressions in CPS code must be in tail position") + case _ => /* do nothing */ + } + val rhs1 = transExpr(rhs, None, getExternalAnswerTypeAnn(tpt.tpe)) debuglog("result "+rhs1) @@ -153,7 +165,6 @@ abstract class SelectiveANFTransform extends PluginComponent with Transform with } } - def transExpr(tree: Tree, cpsA: CPSInfo, cpsR: CPSInfo): Tree = { transTailValue(tree, cpsA, cpsR) match { case (Nil, b) => b |