diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala index 0c32ff32c0..915d7a98db 100644 --- a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala +++ b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala @@ -326,22 +326,35 @@ trait MethodSynthesis { super.validate() } - // keep type tree of original abstract field - private def fixTypeTree(dd: DefDef): DefDef = { - dd.tpt match { - case tt: TypeTree if dd.rhs == EmptyTree => - tt setOriginal tree.tpt - case tpt => - tpt setPos tree.tpt.pos.focus - } - dd - } override def derivedTree: DefDef = { - fixTypeTree { - DefDef(derivedSym, - if (mods.isDeferred) EmptyTree - else gen.mkCheckInit(fieldSelection) - ) + // For existentials, don't specify a type for the getter, even one derived + // from the symbol! This leads to incompatible existentials for the field and + // the getter. Let the typer do all the work. You might think "why only for + // existentials, why not always," and you would be right, except: a single test + // fails, but it looked like some work to deal with it. Test neg/t0606.scala + // starts compiling (instead of failing like it's supposed to) because the typer + // expects to be able to identify escaping locals in typedDefDef, and fails to + // spot that brand of them. In other words it's an artifact of the implementation. + val tpt = derivedSym.tpe.finalResultType match { + case ExistentialType(_, _) => TypeTree() + case tp => TypeTree(tp) + } + tpt setPos focusPos(derivedSym.pos) + // keep type tree of original abstract field + if (mods.isDeferred) + tpt setOriginal tree.tpt + + // TODO - reconcile this with the DefDef creator in Trees (which + // at this writing presented no way to pass a tree in for tpt.) + atPos(derivedSym.pos) { + DefDef( + Modifiers(derivedSym.flags), + derivedSym.name.toTermName, + Nil, + Nil, + tpt, + if (mods.isDeferred) EmptyTree else gen.mkCheckInit(fieldSelection) + ) setSymbol derivedSym } } } |