diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/transform/TailCalls.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/TailCalls.scala | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/TailCalls.scala b/src/compiler/scala/tools/nsc/transform/TailCalls.scala index 6ebecb02c6..9915f7e9fc 100644 --- a/src/compiler/scala/tools/nsc/transform/TailCalls.scala +++ b/src/compiler/scala/tools/nsc/transform/TailCalls.scala @@ -36,7 +36,7 @@ abstract class TailCalls extends Transform { } } - private def hasSynthCaseSymbol(t: Tree) = (t.symbol ne null) && (t.symbol hasFlag (Flags.CASE | Flags.SYNTHETIC)) + import gen.hasSynthCaseSymbol /** * A Tail Call Transformer @@ -341,13 +341,18 @@ abstract class TailCalls extends Transform { else if (fun.symbol.isLabel && args.nonEmpty && args.tail.isEmpty && ctx.tailLabels(fun.symbol)) { // this is to detect tailcalls in translated matches // it's a one-argument call to a label that is in a tailposition and that looks like label(x) {x} - // thus, the argument to the call is in tailposition and we don't need to jump to the label, tail jump instead + // thus, the argument to the call is in tailposition val saved = ctx.tailPos ctx.tailPos = true debuglog("in tailpos label: "+ args.head) val res = transform(args.head) ctx.tailPos = saved - if (res ne args.head) res // we tail-called -- TODO: shield from false-positives where we rewrite but don't tail-call + if (res ne args.head) { + // we tail-called -- TODO: shield from false-positives where we rewrite but don't tail-call + // must leave the jump to the original tailpos-label (fun)! + // there might be *a* tailcall *in* res, but it doesn't mean res *always* tailcalls + treeCopy.Apply(tree, fun, List(res)) + } else rewriteApply(fun, fun, Nil, args) } else rewriteApply(fun, fun, Nil, args) |