diff options
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/Constructors.scala | 178 | ||||
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/UnCurry.scala | 18 |
2 files changed, 96 insertions, 100 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala index 7c66bda46b..6ecdd2b195 100644 --- a/src/compiler/scala/tools/nsc/transform/Constructors.scala +++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala @@ -396,9 +396,9 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { } if (stat1 eq stat) { - assert(ctorParams(genericClazz).length == constrInfo.constrParams.length) + assert(ctorParams(genericClazz).length == primaryConstrParams.length) // this is just to make private fields public - (new specializeTypes.ImplementationAdapter(ctorParams(genericClazz), constrInfo.constrParams, null, true))(stat1) + (new specializeTypes.ImplementationAdapter(ctorParams(genericClazz), primaryConstrParams, null, true))(stat1) val stat2 = rewriteArrayUpdate(stat1) // statements coming from the original class need retyping in the current context @@ -435,16 +435,16 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { // postfix = postfix.tail // } - if (shouldGuard && usesSpecializedField && stats.nonEmpty) { + if (guardSpecializedFieldInit && intoConstructor.usesSpecializedField && stats.nonEmpty) { // save them for duplication in the specialized subclass guardedCtorStats(clazz) = stats - ctorParams(clazz) = constrInfo.constrParams + ctorParams(clazz) = primaryConstrParams val tree = If( Apply( CODE.NOT ( - Apply(gen.mkAttributedRef(specializedFlag), List())), + Apply(gen.mkAttributedRef(hasSpecializedFieldsSym), List())), List()), Block(stats, Literal(Constant(()))), EmptyTree) @@ -476,27 +476,17 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { val stats = impl.body // the transformed template body val localTyper = typer.atOwner(impl, clazz) - val specializedFlag: Symbol = clazz.info.decl(nme.SPECIALIZED_INSTANCE) - val shouldGuard = (specializedFlag != NoSymbol) && !clazz.hasFlag(SPECIALIZED) - - val isDelayedInitSubclass = (clazz isSubClass DelayedInitClass) - - case class ConstrInfo( - constr: DefDef, // The primary constructor - constrParams: List[Symbol], // ... and its parameters - constrBody: Block // ... and its body - ) - // decompose primary constructor into the three entities above. - val constrInfo: ConstrInfo = { - val ddef = (stats find (_.symbol.isPrimaryConstructor)) - ddef match { - case Some(ddef @ DefDef(_, _, _, List(vparams), _, rhs @ Block(_, _))) => - ConstrInfo(ddef, vparams map (_.symbol), rhs) - case x => - abort("no constructor in template: impl = " + impl) - } - } - import constrInfo._ + val hasSpecializedFieldsSym = clazz.info.decl(nme.SPECIALIZED_INSTANCE) + // The constructor of a non-specialized class that has specialized subclasses + // should use `q"${hasSpecializedFieldsSym}()"` to guard the initialization of specialized fields. + val guardSpecializedFieldInit = (hasSpecializedFieldsSym != NoSymbol) && !clazz.hasFlag(SPECIALIZED) + + val isDelayedInitSubclass = clazz isSubClass DelayedInitClass + + // find and dissect primary constructor + val (primaryConstr, primaryConstrParams, primaryConstrBody) = stats collectFirst { + case dd@DefDef(_, _, _, vps :: Nil, _, rhs: Block) if dd.symbol.isPrimaryConstructor => (dd, vps map (_.symbol), rhs) + } getOrElse abort("no constructor in template: impl = " + impl) // The parameter accessor fields which are members of the class val paramAccessors = clazz.constrParamAccessors @@ -509,27 +499,26 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { def parameterNamed(name: Name): Symbol = { def matchesName(param: Symbol) = param.name == name || param.name.startsWith(name + nme.NAME_JOIN_STRING) - (constrParams filter matchesName) match { - case Nil => abort(name + " not in " + constrParams) + primaryConstrParams filter matchesName match { + case Nil => abort(name + " not in " + primaryConstrParams) case p :: _ => p } } - /* - * `usesSpecializedField` makes a difference in deciding whether constructor-statements - * should be guarded in a `shouldGuard` class, ie in a class that's the generic super-class of - * one or more specialized sub-classes. - * - * Given that `usesSpecializedField` isn't read for any other purpose than the one described above, - * we skip setting `usesSpecializedField` in case the current class isn't `shouldGuard` to start with. - * That way, trips to a map in `specializeTypes` are saved. - */ - var usesSpecializedField: Boolean = false - // A transformer for expressions that go into the constructor - private class IntoCtorTransformer extends Transformer { - - private def isParamRef(sym: Symbol) = (sym.isParamAccessor && sym.owner == clazz) + object intoConstructor extends Transformer { + /* + * `usesSpecializedField` makes a difference in deciding whether constructor-statements + * should be guarded in a `guardSpecializedFieldInit` class, ie in a class that's the generic super-class of + * one or more specialized sub-classes. + * + * Given that `usesSpecializedField` isn't read for any other purpose than the one described above, + * we skip setting `usesSpecializedField` in case the current class isn't `guardSpecializedFieldInit` to start with. + * That way, trips to a map in `specializeTypes` are saved. + */ + var usesSpecializedField: Boolean = false + + private def isParamRef(sym: Symbol) = sym.isParamAccessor && sym.owner == clazz // Terminology: a stationary location is never written after being read. private def isStationaryParamRef(sym: Symbol) = ( @@ -548,10 +537,9 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * (b.2) the constructor in the specialized (sub-)class. * (c) isn't part of a DelayedInit subclass. */ - private def canBeSupplanted(sym: Symbol) = (!isDelayedInitSubclass && isStationaryParamRef(sym) && !possiblySpecialized(sym)) + private def canBeSupplanted(sym: Symbol) = !isDelayedInitSubclass && isStationaryParamRef(sym) && !possiblySpecialized(sym) override def transform(tree: Tree): Tree = tree match { - case Apply(Select(This(_), _), List()) => // references to parameter accessor methods of own class become references to parameters // outer accessors become references to $outer parameter @@ -566,7 +554,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { // references to parameter accessor field of own class become references to parameters gen.mkAttributedIdent(parameter(tree.symbol)) setPos tree.pos - case Select(_, _) if shouldGuard => // reasoning behind this guard in the docu of `usesSpecializedField` + case Select(_, _) if guardSpecializedFieldInit => // reasoning behind this guard in the docu of `usesSpecializedField` if (possiblySpecialized(tree.symbol)) { usesSpecializedField = true } @@ -576,18 +564,10 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { super.transform(tree) } - } - - private val intoConstructorTransformer = new IntoCtorTransformer - - // Move tree into constructor, take care of changing owner from `oldowner` to constructor symbol - def intoConstructor(oldowner: Symbol, tree: Tree) = - intoConstructorTransformer transform tree.changeOwner(oldowner -> constr.symbol) - - // Should tree be moved in front of super constructor call? - def canBeMoved(tree: Tree) = tree match { - case ValDef(mods, _, _, _) => (mods hasFlag PRESUPER | PARAMACCESSOR) - case _ => false + // Move tree into constructor, take care of changing owner from `oldowner` to constructor symbol + def apply(oldowner: Symbol, tree: Tree) = + if (tree eq EmptyTree) tree + else transform(tree.changeOwner(oldowner -> primaryConstr.symbol)) } // Create an assignment to class field `to` with rhs `from` @@ -629,10 +609,10 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { val classInitStatBuf = new ListBuffer[Tree] // generate code to copy pre-initialized fields - for (stat <- constrBody.stats) { + for (stat <- primaryConstrBody.stats) { constrStatBuf += stat stat match { - case ValDef(mods, name, _, _) if (mods hasFlag PRESUPER) => + case ValDef(mods, name, _, _) if mods hasFlag PRESUPER => // stat is the constructor-local definition of the field value val fields = presupers filter (_.getterName == name) assert(fields.length == 1) @@ -643,45 +623,48 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { } } - // Triage all template definitions to go into defBuf/auxConstructorBuf, constrStatBuf, or constrPrefixBuf. - for (stat <- stats) stat match { - case DefDef(_,_,_,_,_,rhs) => - // methods with constant result type get literals as their body - // all methods except the primary constructor go into template - stat.symbol.tpe match { - case MethodType(List(), tp @ ConstantType(c)) => - defBuf += deriveDefDef(stat)(Literal(c) setPos _.pos setType tp) - case _ => - if (stat.symbol.isPrimaryConstructor) () - else if (stat.symbol.isConstructor) auxConstructorBuf += stat - else defBuf += stat - } - case ValDef(mods, _, _, rhs) if !mods.hasStaticFlag => + + for (stat <- stats) { + val statSym = stat.symbol + + stat match { + // recurse on class definition, store in defBuf + case _: ClassDef => defBuf += new ConstructorTransformer(unit).transform(stat) + + // methods (except primary constructor) go into template + // (non-primary ctors --> auxConstructorBuf / regular defs --> defBuf) + case _: DefDef if statSym.isPrimaryConstructor => () + case _: DefDef if statSym.isConstructor => auxConstructorBuf += stat + case _: DefDef => defBuf += stat + // val defs with constant right-hand sides are eliminated. - // for all other val defs, an empty valdef goes into the template and - // the initializer goes as an assignment into the constructor - // if the val def is an early initialized or a parameter accessor, it goes - // before the superclass constructor call, otherwise it goes after. - // Lazy vals don't get the assignment in the constructor. - if (!stat.symbol.tpe.isInstanceOf[ConstantType]) { - if (rhs != EmptyTree && !stat.symbol.isLazy) { - val rhs1 = intoConstructor(stat.symbol, rhs) - (if (canBeMoved(stat)) constrPrefixBuf else constrStatBuf) += mkAssign( - stat.symbol, rhs1) + 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: + // - 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, 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) } + defBuf += deriveValDef(stat)(_ => EmptyTree) - } - case ValDef(_, _, _, rhs) => - // Add static initializer statements to classInitStatBuf and remove the rhs from the val def. - classInitStatBuf += mkAssign(stat.symbol, rhs) - defBuf += deriveValDef(stat)(_ => EmptyTree) - - case ClassDef(_, _, _, _) => - // classes are treated recursively, and left in the template - defBuf += new ConstructorTransformer(unit).transform(stat) - case _ => + // all other statements go into the constructor - constrStatBuf += intoConstructor(impl.symbol, stat) + case _ => constrStatBuf += intoConstructor(impl.symbol, stat) + } } populateOmittables() @@ -716,12 +699,12 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { rewriteDelayedInit() // Assemble final constructor - defBuf += deriveDefDef(constr)(_ => + defBuf += deriveDefDef(primaryConstr)(_ => treeCopy.Block( - constrBody, + primaryConstrBody, paramInits ::: constrPrefixBuf.toList ::: uptoSuperStats ::: guardSpecializedInitializer(remainingConstrStats), - constrBody.expr)) + primaryConstrBody.expr)) // Followed by any auxiliary constructors defBuf ++= auxConstructorBuf @@ -732,6 +715,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { // Eliminate all field definitions that can be dropped from template val templateWithoutOmittables: Template = deriveTemplate(impl)(_ => defBuf.toList filter (stat => mustBeKept(stat.symbol))) + // Add the static initializers val transformed: Template = addStaticInits(templateWithoutOmittables, classInitStatBuf, localTyper) diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala index 72e2174bf8..79a77d7a0c 100644 --- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala +++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala @@ -582,6 +582,7 @@ abstract class UnCurry extends InfoTransform } case dd @ DefDef(_, _, _, vparamss0, _, rhs0) => + val ddSym = dd.symbol val (newParamss, newRhs): (List[List[ValDef]], Tree) = if (dependentParamTypeErasure isDependent dd) dependentParamTypeErasure erase dd @@ -593,11 +594,22 @@ abstract class UnCurry extends InfoTransform (vparamss1, rhs0) } + // A no-arg method with ConstantType result type can safely be reduced to the corresponding Literal + // (only pure methods are typed as ConstantType). We could also do this for methods with arguments, + // after ensuring the arguments are not referenced. + val literalRhsIfConst = + if (newParamss.head.isEmpty) { // We know newParamss.length == 1 from above + ddSym.info.resultType match { + case tp@ConstantType(value) => Literal(value) setType tp setPos newRhs.pos // inlining of gen.mkAttributedQualifier(tp) + case _ => newRhs + } + } else newRhs + val flatdd = copyDefDef(dd)( vparamss = newParamss, - rhs = nonLocalReturnKeys get dd.symbol match { - case Some(k) => atPos(newRhs.pos)(nonLocalReturnTry(newRhs, k, dd.symbol)) - case None => newRhs + rhs = nonLocalReturnKeys get ddSym match { + case Some(k) => atPos(newRhs.pos)(nonLocalReturnTry(literalRhsIfConst, k, ddSym)) + case None => literalRhsIfConst } ) addJavaVarargsForwarders(dd, flatdd) |