diff options
Diffstat (limited to 'src/dotty/tools/dotc/transform/TailRec.scala')
| -rw-r--r-- | src/dotty/tools/dotc/transform/TailRec.scala | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/dotty/tools/dotc/transform/TailRec.scala b/src/dotty/tools/dotc/transform/TailRec.scala index 23686b522..427884e14 100644 --- a/src/dotty/tools/dotc/transform/TailRec.scala +++ b/src/dotty/tools/dotc/transform/TailRec.scala @@ -180,7 +180,7 @@ class TailRec extends MiniPhaseTransform with DenotTransformer with FullParamete override def transform(tree: Tree)(implicit c: Context): Tree = { /* A possibly polymorphic apply to be considered for tail call transformation. */ - def rewriteApply(tree: Tree, sym: Symbol): Tree = { + def rewriteApply(tree: Tree, sym: Symbol, required: Boolean = false): Tree = { def receiverArgumentsAndSymbol(t: Tree, accArgs: List[List[Tree]] = Nil, accT: List[Tree] = Nil): (Tree, Tree, List[List[Tree]], List[Tree], Symbol) = t match { case TypeApply(fun, targs) if fun.symbol eq t.symbol => receiverArgumentsAndSymbol(fun, accArgs, targs) @@ -216,7 +216,7 @@ class TailRec extends MiniPhaseTransform with DenotTransformer with FullParamete } } def fail(reason: String) = { - if (isMandatory) c.error(s"Cannot rewrite recursive call: $reason", tree.pos) + if (isMandatory || required) c.error(s"Cannot rewrite recursive call: $reason", tree.pos) else c.debuglog("Cannot rewrite recursive call at: " + tree.pos + " because: " + reason) continue } @@ -299,7 +299,8 @@ class TailRec extends MiniPhaseTransform with DenotTransformer with FullParamete noTailTransforms(stats), transform(expr) ) - + case tree @ Typed(t: Apply, tpt) if tpt.tpe.hasAnnotation(defn.TailrecAnnot) => + tpd.Typed(rewriteApply(t, t.fun.symbol, required = true), tpt) case tree@If(cond, thenp, elsep) => tpd.cpy.If(tree)( noTailTransform(cond), |