diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/Constructors.scala | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala index 5b27f86ed8..46f93b81e8 100644 --- a/src/compiler/scala/tools/nsc/transform/Constructors.scala +++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala @@ -631,6 +631,29 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { for (stat <- stats) { val statSym = stat.symbol + // Move the RHS of a Val/Def (traits don't have vals, their getter holds the RHS) to the appropriate part of the ctor. + // If the val def is an early initialized or a parameter accessor, + // it goes before the superclass constructor call, otherwise it goes after. + // A lazy val's effect is not moved to the constructor, as it is delayed. + // Returns `true` when a `ValDef` is needed. + def moveEffectToCtor(mods: Modifiers, rhs: Tree) = { + val const = statSym.info.isInstanceOf[ConstantType] + val initializingRhs = + if (statSym.isLazy || const) EmptyTree + else if (!mods.hasStaticFlag) intoConstructor(statSym, primaryConstr.symbol)(rhs) + else rhs + + if (initializingRhs ne EmptyTree) { + val initPhase = + if (mods hasFlag STATIC) classInitStatBuf + else if (mods hasFlag PRESUPER | PARAMACCESSOR) constrPrefixBuf + else constrStatBuf + + initPhase += mkAssign(statSym, initializingRhs) + } + !const // needs field unless it's a constant + } + stat match { // recurse on class definition, store in defBuf case _: ClassDef => defBuf += new ConstructorTransformer(unit).transform(stat) @@ -642,30 +665,15 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { case _: DefDef if statSym.isConstructor => auxConstructorBuf += stat case _: DefDef => defBuf += stat - // val defs with constant right-hand sides are eliminated. - case _: ValDef if statSym.info.isInstanceOf[ConstantType] => () - - // For all other val defs, an empty valdef goes into the template. - // Additionally, non-lazy vals are initialized by an assignment in: + // If a val needs a field, an empty valdef goes into the template. + // Except for lazy and ConstantTyped vals, the field is initialized by an assignment in: // - the class initializer (static), // - the constructor, before the super call (early initialized or a parameter accessor), // - the constructor, after the super call (regular val). case ValDef(mods, _, _, rhs) => - val initializingRhs = - if (statSym.isLazy) EmptyTree - else if (!mods.hasStaticFlag) intoConstructor(statSym, primaryConstr.symbol)(rhs) - else rhs - - if (initializingRhs ne EmptyTree) { - val initPhase = - if (mods hasFlag STATIC) classInitStatBuf - else if (mods hasFlag PRESUPER | PARAMACCESSOR) constrPrefixBuf - else constrStatBuf - - initPhase += mkAssign(statSym, initializingRhs) - } + val memoized = moveEffectToCtor(mods, rhs) - defBuf += deriveValDef(stat)(_ => EmptyTree) + if (memoized) defBuf += deriveValDef(stat)(_ => EmptyTree) // all other statements go into the constructor case _ => constrStatBuf += intoConstructor(impl.symbol, primaryConstr.symbol)(stat) |