diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/transform')
31 files changed, 2886 insertions, 3220 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/AccessorSynthesis.scala b/src/compiler/scala/tools/nsc/transform/AccessorSynthesis.scala new file mode 100644 index 0000000000..e027b065ac --- /dev/null +++ b/src/compiler/scala/tools/nsc/transform/AccessorSynthesis.scala @@ -0,0 +1,403 @@ +/* NSC -- new Scala compiler + * Copyright 2005-2013 LAMP/EPFL and Lightbend, Inc + */ + +package scala.tools.nsc +package transform + +import symtab._ +import Flags._ +import scala.collection.mutable + +trait AccessorSynthesis extends Transform with ast.TreeDSL { + import global._ + import definitions._ + import CODE._ + + val EmptyThicket = EmptyTree + def Thicket(trees: List[Tree]) = if (trees.isEmpty) EmptyTree else Block(trees, EmptyTree) + def mustExplodeThicket(tree: Tree): Boolean = + tree match { + case EmptyTree => true + case Block(_, EmptyTree) => true + case _ => false + } + def explodeThicket(tree: Tree): List[Tree] = tree match { + case EmptyTree => Nil + case Block(thicket, EmptyTree) => thicket + case stat => stat :: Nil + } + + + trait AccessorTreeSynthesis { + protected def typedPos(pos: Position)(tree: Tree): Tree + + // used while we still need to synthesize some accessors in mixins: paramaccessors and presupers + class UncheckedAccessorSynth(protected val clazz: Symbol){ + protected val _newDefs = mutable.ListBuffer[Tree]() + + def newDefs = _newDefs.toList + + /** Add tree at given position as new definition */ + protected def addDef(tree: ValOrDefDef): Unit = _newDefs += typedPos(position(tree.symbol))(tree) + + /** The position of given symbol, or, if this is undefined, + * the position of the current class. + */ + private def position(sym: Symbol) = if (sym.pos == NoPosition) clazz.pos else sym.pos + + /** Add new method definition. + * + * @param sym The method symbol. + * @param rhs The method body. + */ + def addDefDef(sym: Symbol, rhs: Tree = EmptyTree) = addDef(DefDef(sym, rhs)) + def addValDef(sym: Symbol, rhs: Tree = EmptyTree) = addDef(ValDef(sym, rhs)) + + /** Complete `stats` with init checks and bitmaps, + * removing any abstract method definitions in `stats` that are + * matched by some symbol defined by a tree previously passed to `addDef`. + */ + def implementWithNewDefs(stats: List[Tree]): List[Tree] = { + val newDefs = _newDefs.toList + val newSyms = newDefs map (_.symbol) + def isNotDuplicate(tree: Tree) = tree match { + case DefDef(_, _, _, _, _, _) => + val sym = tree.symbol + !(sym.isDeferred && + (newSyms exists (nsym => nsym.name == sym.name && (nsym.tpe matches sym.tpe)))) + case _ => true + } + if (newDefs.isEmpty) stats + else newDefs ::: (stats filter isNotDuplicate) + } + + def accessorBody(sym: Symbol) = + if (sym.isSetter) setterBody(sym, sym.getterIn(clazz)) else getterBody(sym) + + protected def getterBody(getter: Symbol): Tree = { + assert(getter.isGetter) + assert(getter.hasFlag(PARAMACCESSOR)) + + fieldAccess(getter) + } + + protected def setterBody(setter: Symbol, getter: Symbol): Tree = { + assert(getter.hasFlag(PARAMACCESSOR), s"missing implementation for non-paramaccessor $setter in $clazz") + + Assign(fieldAccess(setter), Ident(setter.firstParam)) + } + + private def fieldAccess(accessor: Symbol) = + Select(This(clazz), accessor.accessed) + + } + } + + case class BitmapInfo(symbol: Symbol, mask: Literal) { + def storageClass: ClassSymbol = symbol.info.typeSymbol.asClass + } + + + // TODO: better way to communicate from info transform to tree transform? + private[this] val _bitmapInfo = perRunCaches.newMap[Symbol, BitmapInfo] + private[this] val _slowPathFor = perRunCaches.newMap[Symbol, Symbol]() + + def checkedAccessorSymbolSynth(clz: Symbol) = + if (settings.checkInit) new CheckInitAccessorSymbolSynth { val clazz = clz } + else new CheckedAccessorSymbolSynth { val clazz = clz } + + // base trait, with enough functionality for lazy vals -- CheckInitAccessorSymbolSynth adds logic for -Xcheckinit + trait CheckedAccessorSymbolSynth { + protected val clazz: Symbol + + protected def defaultPos = clazz.pos.focus + protected def isTrait = clazz.isTrait + protected def hasTransientAnnot(field: Symbol) = field.accessedOrSelf hasAnnotation TransientAttr + + def needsBitmap(sym: Symbol): Boolean = !(isTrait || sym.isDeferred) && sym.isMethod && sym.isLazy && !sym.isSpecialized + + + /** Examines the symbol and returns a name indicating what brand of + * bitmap it requires. The possibilities are the BITMAP_* vals + * defined in StdNames. If it needs no bitmap, nme.NO_NAME. + * + * bitmaps for checkinit fields are not inherited + */ + protected def bitmapCategory(sym: Symbol): Name = { + // ensure that nested objects are transformed TODO: still needed? + sym.initialize + + import nme._ + + if (needsBitmap(sym) && sym.isLazy) + if (hasTransientAnnot(sym)) BITMAP_TRANSIENT else BITMAP_NORMAL + else NO_NAME + } + + + def bitmapFor(sym: Symbol): BitmapInfo = _bitmapInfo(sym) + protected def hasBitmap(sym: Symbol): Boolean = _bitmapInfo isDefinedAt sym + + + /** Fill the map from fields to bitmap infos. + * + * Instead of field symbols, the map keeps their getter symbols. This makes code generation easier later. + */ + def computeBitmapInfos(decls: List[Symbol]): List[Symbol] = { + def doCategory(fields: List[Symbol], category: Name) = { + val nbFields = fields.length // we know it's > 0 + val (bitmapClass, bitmapCapacity) = + if (nbFields == 1) (BooleanClass, 1) + else if (nbFields <= 8) (ByteClass, 8) + else if (nbFields <= 32) (IntClass, 32) + else (LongClass, 64) + + // 0-based index of highest bit, divided by bits per bitmap + // note that this is only ever > 0 when bitmapClass == LongClass + val maxBitmapNumber = (nbFields - 1) / bitmapCapacity + + // transient fields get their own category + val isTransientCategory = fields.head hasAnnotation TransientAttr + + val bitmapSyms = + (0 to maxBitmapNumber).toArray map { bitmapNumber => + val bitmapSym = ( + clazz.newVariable(nme.newBitmapName(category, bitmapNumber).toTermName, defaultPos) + setInfo bitmapClass.tpe + setFlag PrivateLocal | NEEDS_TREES + ) + + bitmapSym addAnnotation VolatileAttr + + if (isTransientCategory) bitmapSym addAnnotation TransientAttr + + bitmapSym + } + + fields.zipWithIndex foreach { case (f, idx) => + val bitmapIdx = idx / bitmapCapacity + val offsetInBitmap = idx % bitmapCapacity + val mask = + if (bitmapClass == LongClass) Constant(1L << offsetInBitmap) + else Constant(1 << offsetInBitmap) + + _bitmapInfo(f) = BitmapInfo(bitmapSyms(bitmapIdx), Literal(mask)) + } + + bitmapSyms + } + + decls groupBy bitmapCategory flatMap { + case (category, fields) if category != nme.NO_NAME && fields.nonEmpty => doCategory(fields, category) + case _ => Nil + } toList + } + + def slowPathFor(lzyVal: Symbol): Symbol = _slowPathFor(lzyVal) + + def newSlowPathSymbol(lzyVal: Symbol): Symbol = { + val pos = if (lzyVal.pos != NoPosition) lzyVal.pos else defaultPos // TODO: is the else branch ever taken? + val sym = clazz.newMethod(nme.newLazyValSlowComputeName(lzyVal.name.toTermName), pos, PRIVATE) setInfo MethodType(Nil, lzyVal.tpe.resultType) + _slowPathFor(lzyVal) = sym + sym + } + + } + + trait CheckInitAccessorSymbolSynth extends CheckedAccessorSymbolSynth { + /** Does this field require an initialized bit? + * Note: fields of classes inheriting DelayedInit are not checked. + * This is because they are neither initialized in the constructor + * nor do they have a setter (not if they are vals anyway). The usual + * logic for setting bitmaps does therefore not work for such fields. + * That's why they are excluded. + * Note: The `checkinit` option does not check if transient fields are initialized. + */ + protected def needsInitFlag(sym: Symbol): Boolean = + sym.isGetter && + !( sym.isInitializedToDefault + || isConstantType(sym.info.finalResultType) // SI-4742 + || sym.hasFlag(PARAMACCESSOR | SPECIALIZED | LAZY) + || sym.accessed.hasFlag(PRESUPER) + || sym.isOuterAccessor + || (sym.owner isSubClass DelayedInitClass) + || (sym.accessed hasAnnotation TransientAttr)) + + /** Examines the symbol and returns a name indicating what brand of + * bitmap it requires. The possibilities are the BITMAP_* vals + * defined in StdNames. If it needs no bitmap, nme.NO_NAME. + * + * bitmaps for checkinit fields are not inherited + */ + override protected def bitmapCategory(sym: Symbol): Name = { + import nme._ + + super.bitmapCategory(sym) match { + case NO_NAME if needsInitFlag(sym) && !sym.isDeferred => + if (hasTransientAnnot(sym)) BITMAP_CHECKINIT_TRANSIENT else BITMAP_CHECKINIT + case category => category + } + } + + override def needsBitmap(sym: Symbol): Boolean = super.needsBitmap(sym) || !(isTrait || sym.isDeferred) && needsInitFlag(sym) + } + + + // synthesize trees based on info gathered during info transform + // (which are known to have been run because the tree transform runs afterOwnPhase) + // since we can't easily share all info via symbols and flags, we have two maps above + // (they are persisted even between phases because the -Xcheckinit logic runs during constructors) + // TODO: can we use attachments instead of _bitmapInfo and _slowPathFor? + trait CheckedAccessorTreeSynthesis extends AccessorTreeSynthesis { + + // note: we deal in getters here, not field symbols + trait SynthCheckedAccessorsTreesInClass extends CheckedAccessorSymbolSynth { + def isUnitGetter(sym: Symbol) = sym.tpe.resultType.typeSymbol == UnitClass + def thisRef = gen.mkAttributedThis(clazz) + + /** Return an (untyped) tree of the form 'clazz.this.bitmapSym & mask (==|!=) 0', the + * precise comparison operator depending on the value of 'equalToZero'. + */ + def mkTest(field: Symbol, equalToZero: Boolean = true): Tree = { + val bitmap = bitmapFor(field) + val bitmapTree = thisRef DOT bitmap.symbol + + if (bitmap.storageClass == BooleanClass) { + if (equalToZero) NOT(bitmapTree) else bitmapTree + } else { + val lhs = bitmapTree GEN_&(bitmap.mask, bitmap.storageClass) + if (equalToZero) lhs GEN_==(ZERO, bitmap.storageClass) + else lhs GEN_!=(ZERO, bitmap.storageClass) + } + } + + /** Return an (untyped) tree of the form 'Clazz.this.bmp = Clazz.this.bmp | mask'. */ + def mkSetFlag(valSym: Symbol): Tree = { + val bitmap = bitmapFor(valSym) + def x = thisRef DOT bitmap.symbol + + Assign(x, + if (bitmap.storageClass == BooleanClass) TRUE + else { + val or = Apply(Select(x, getMember(bitmap.storageClass, nme.OR)), List(bitmap.mask)) + // NOTE: bitwise or (`|`) on two bytes yields and Int (TODO: why was this not a problem when this ran during mixins?) + // TODO: need this to make it type check -- is there another way?? + if (bitmap.storageClass != LongClass) Apply(Select(or, newTermName("to" + bitmap.storageClass.name)), Nil) + else or + } + ) + } + } + + class SynthLazyAccessorsIn(protected val clazz: Symbol) extends SynthCheckedAccessorsTreesInClass { + /** + * The compute method (slow path) looks like: + * + * ``` + * def l$compute() = { + * synchronized(this) { + * if ((bitmap$n & MASK) == 0) { + * init // l$ = <rhs> + * bitmap$n = bimap$n | MASK + * } + * } + * ... + * this.f1 = null + * ... + * this.fn = null + * l$ + * } + * ``` + * + * `bitmap$n` is a byte, int or long value acting as a bitmap of initialized values. + * The kind of the bitmap determines how many bit indicators for lazy vals are stored in it. + * For Int bitmap it is 32 and then 'n' in the above code is: (offset / 32), + * the MASK is (1 << (offset % 32)). + * + * If the class contains only a single lazy val then the bitmap is + * represented as a Boolean and the condition checking is a simple bool test. + * + * Private fields used only in this initializer are subsequently set to null. + * + * For performance reasons the double-checked locking is split into two parts, + * the first (fast) path checks the bitmap without synchronizing, and if that + * fails it initializes the lazy val within the synchronization block (slow path). + * + * This way the inliner should optimize the fast path because the method body is small enough. + */ + def expandLazyClassMember(lazyVar: global.Symbol, lazyAccessor: global.Symbol, transformedRhs: global.Tree): Tree = { + val slowPathSym = slowPathFor(lazyAccessor) + val rhsAtSlowDef = transformedRhs.changeOwner(lazyAccessor -> slowPathSym) + + val isUnit = isUnitGetter(lazyAccessor) + val selectVar = if (isUnit) UNIT else Select(thisRef, lazyVar) + val storeRes = if (isUnit) rhsAtSlowDef else Assign(selectVar, fields.castHack(rhsAtSlowDef, lazyVar.info)) + + def needsInit = mkTest(lazyAccessor) + val doInit = Block(List(storeRes), mkSetFlag(lazyAccessor)) + // the slow part of double-checked locking (TODO: is this the most efficient pattern? https://github.come/scala/scala-dev/issues/204) + val slowPathRhs = Block(gen.mkSynchronized(thisRef)(If(needsInit, doInit, EmptyTree)) :: Nil, selectVar) + + // The lazy accessor delegates to the compute method if needed, otherwise just accesses the var (it was initialized previously) + // `if ((bitmap&n & MASK) == 0) this.l$compute() else l$` + val accessorRhs = If(needsInit, Apply(Select(thisRef, slowPathSym), Nil), selectVar) + + afterOwnPhase { // so that we can assign to vals + Thicket(List((DefDef(slowPathSym, slowPathRhs)), DefDef(lazyAccessor, accessorRhs)) map typedPos(lazyAccessor.pos.focus)) + } + } + } + + class SynthInitCheckedAccessorsIn(protected val clazz: Symbol) extends SynthCheckedAccessorsTreesInClass with CheckInitAccessorSymbolSynth { + private object addInitBitsTransformer extends Transformer { + private def checkedGetter(lhs: Tree)(pos: Position) = { + val getter = clazz.info decl lhs.symbol.getterName suchThat (_.isGetter) + if (hasBitmap(getter) && needsInitFlag(getter)) { + debuglog("adding checked getter for: " + getter + " " + lhs.symbol.flagString) + List(typedPos(pos)(mkSetFlag(getter))) + } + else Nil + } + override def transformStats(stats: List[Tree], exprOwner: Symbol) = { + // !!! Ident(self) is never referenced, is it supposed to be confirming + // that self is anything in particular? + super.transformStats( + stats flatMap { + case stat@Assign(lhs@Select(This(_), _), rhs) => stat :: checkedGetter(lhs)(stat.pos.focus) + // remove initialization for default values -- TODO is this case ever hit? constructors does not generate Assigns with EmptyTree for the rhs AFAICT + case Apply(lhs@Select(Ident(self), _), EmptyTree.asList) if lhs.symbol.isSetter => Nil + case stat => List(stat) + }, + exprOwner + ) + } + } + + /** Make getters check the initialized bit, and the class constructor & setters are changed to set the initialized bits. */ + def wrapRhsWithInitChecks(sym: Symbol)(rhs: Tree): Tree = { + // Add statements to the body of a constructor to set the 'init' bit for each field initialized in the constructor + if (sym.isConstructor) addInitBitsTransformer transform rhs + else if (isTrait || rhs == EmptyTree) rhs + else if (needsInitFlag(sym)) // getter + mkCheckedAccessorRhs(if (isUnitGetter(sym)) UNIT else rhs, rhs.pos, sym) + else if (sym.isSetter) { + val getter = sym.getterIn(clazz) + if (needsInitFlag(getter)) Block(List(rhs, typedPos(rhs.pos.focus)(mkSetFlag(getter))), UNIT) + else rhs + } + else rhs + } + + private def mkCheckedAccessorRhs(retVal: Tree, pos: Position, getter: Symbol): Tree = { + val msg = s"Uninitialized field: ${clazz.sourceFile}: ${pos.line}" + val result = + IF(mkTest(getter, equalToZero = false)). + THEN(retVal). + ELSE(Throw(NewFromConstructor(UninitializedFieldConstructor, LIT(msg)))) + + typedPos(pos)(BLOCK(result, retVal)) + } + } + } +} diff --git a/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala b/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala deleted file mode 100644 index 82e7c76409..0000000000 --- a/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala +++ /dev/null @@ -1,376 +0,0 @@ -/* NSC -- new Scala compiler - * Copyright 2005-2013 LAMP/EPFL - * @author Martin Odersky - */ - -package scala.tools.nsc -package transform - -import symtab._ -import Flags._ -import scala.tools.nsc.util.ClassPath - -abstract class AddInterfaces extends InfoTransform { self: Erasure => - import global._ // the global environment - import definitions._ // standard classes and methods - - /** The phase sets lateINTERFACE for non-interface traits that now - * become interfaces. It sets lateDEFERRED for formerly concrete - * methods in such traits. - */ - override def phaseNewFlags: Long = lateDEFERRED | lateINTERFACE - - /** A lazily constructed map that associates every non-interface trait with - * its implementation class. - */ - private val implClassMap = perRunCaches.newMap[Symbol, Symbol]() - - /** A lazily constructed map that associates every concrete method in a non-interface - * trait that's currently compiled with its corresponding method in the trait's - * implementation class. - */ - private val implMethodMap = perRunCaches.newMap[Symbol, Symbol]() - - override def newPhase(prev: scala.tools.nsc.Phase): StdPhase = { - implClassMap.clear() - implMethodMap.clear() - super.newPhase(prev) - } - - /** Is given trait member symbol a member of the trait's interface - * after this transform is performed? - */ - private def isInterfaceMember(sym: Symbol) = ( - sym.isType || { - sym.info // initialize to set lateMETHOD flag if necessary - - ( sym.isMethod - && !sym.isLabel - && !sym.isPrivate - && (!(sym hasFlag BRIDGE) || sym.hasBridgeAnnotation) // count @bridge annotated classes as interface members - && !sym.isConstructor - && !sym.isImplOnly - ) - } - ) - - /** Does symbol need an implementation method? */ - def needsImplMethod(sym: Symbol) = ( - sym.isMethod - && isInterfaceMember(sym) - && (!sym.hasFlag(DEFERRED | SUPERACCESSOR) || (sym hasFlag lateDEFERRED)) - ) - - def implClassPhase = currentRun.erasurePhase.next - - private def newImplClass(iface: Symbol): Symbol = { - val inClass = iface.owner.isClass - val implName = tpnme.implClassName(iface.name) - val implFlags = (iface.flags & ~(INTERFACE | lateINTERFACE)) | IMPLCLASS - - val impl0 = { - if (!inClass) NoSymbol - else { - val typeInfo = iface.owner.info - typeInfo.decl(implName) match { - case NoSymbol => NoSymbol - case implSym => - // Unlink a pre-existing symbol only if the implementation class is - // visible on the compilation classpath. In general this is true under - // -optimise and not otherwise, but the classpath can use arbitrary - // logic so the classpath must be queried. - // TODO this is not taken into account by flat classpath yet - classPath match { - case cp: ClassPath[_] if !cp.context.isValidName(implName + ".class") => - log(s"not unlinking $iface's existing implClass ${implSym.name} because it is not on the classpath.") - implSym - case _ => - typeInfo.decls unlink implSym - NoSymbol - } - } - } - } - - val impl = impl0 orElse { - val impl = iface.owner.newImplClass(implName, iface.pos, implFlags) - if (iface.thisSym != iface) { - impl.typeOfThis = iface.typeOfThis - impl.thisSym setName iface.thisSym.name - } - impl.associatedFile = iface.sourceFile - if (inClass) - iface.owner.info.decls enter impl - - impl - } - if (currentRun compiles iface) - currentRun.symSource(impl) = iface.sourceFile - - implClassMap(iface) = impl - impl setInfo new LazyImplClassType(iface) - } - - /** Return the implementation class of a trait; create a new one if one does not yet exist */ - def implClass(iface: Symbol): Symbol = { - iface.info - - implClassMap.getOrElse(iface, enteringPhase(implClassPhase) { - if (iface.implClass eq NoSymbol) - debuglog(s"${iface.fullLocationString} has no implClass yet, creating it now.") - else - log(s"${iface.fullLocationString} impl class is ${iface.implClass.nameString}") - - newImplClass(iface) - }) - } - - /** A lazy type to set the info of an implementation class - * The parents of an implementation class for trait iface are: - * - * - superclass: Object - * - mixin classes: mixin classes of iface where every non-interface - * trait is mapped to its implementation class, followed by iface itself. - * - * The declarations of a mixin class are: - * - for every interface member of iface: its implementation method, if one is needed - * - every former member of iface that is implementation only - */ - private class LazyImplClassType(iface: Symbol) extends LazyType with FlagAgnosticCompleter { - /** Compute the decls of implementation class implClass, - * given the decls ifaceDecls of its interface. - */ - private def implDecls(implClass: Symbol, ifaceDecls: Scope): Scope = { - debuglog("LazyImplClassType calculating decls for " + implClass) - - val decls = newScope - if ((ifaceDecls lookup nme.MIXIN_CONSTRUCTOR) == NoSymbol) { - log("Adding mixin constructor to " + implClass) - - decls enter ( - implClass.newMethod(nme.MIXIN_CONSTRUCTOR, implClass.pos) - setInfo MethodType(Nil, UnitTpe) - ) - } - - for (sym <- ifaceDecls) { - if (isInterfaceMember(sym)) { - if (needsImplMethod(sym)) { - val clone = sym.cloneSymbol(implClass).resetFlag(lateDEFERRED) - if (currentRun.compiles(implClass)) implMethodMap(sym) = clone - decls enter clone - sym setFlag lateDEFERRED - if (!sym.isSpecialized) - log(s"Cloned ${sym.name} from ${sym.owner} into implClass ${implClass.fullName}") - } - } - else { - log(s"Destructively modifying owner of $sym from ${sym.owner} to $implClass") - sym.owner = implClass - // note: OK to destructively modify the owner here, - // because symbol will not be accessible from outside the sourcefile. - // mixin constructors are corrected separately; see TermSymbol.owner - decls enter sym - } - } - - decls - } - - override def complete(implSym: Symbol) { - debuglog("LazyImplClassType completing " + implSym) - - /* If `tp` refers to a non-interface trait, return a - * reference to its implementation class. Otherwise return `tp`. - */ - def mixinToImplClass(tp: Type): Type = AddInterfaces.this.erasure(implSym) { - tp match { //@MATN: no normalize needed (comes after erasure) - case TypeRef(pre, sym, _) if sym.needsImplClass => - typeRef(pre, implClass(sym), Nil) - case _ => - tp - } - } - def implType(tp: Type): Type = tp match { - case ClassInfoType(parents, decls, _) => - assert(phase == implClassPhase, tp) - // Impl class parents: Object first, matching interface last. - val implParents = ObjectTpe +: (parents.tail map mixinToImplClass filter (_.typeSymbol != ObjectClass)) :+ iface.tpe - ClassInfoType(implParents, implDecls(implSym, decls), implSym) - case PolyType(_, restpe) => - implType(restpe) - } - implSym setInfo implType(enteringErasure(iface.info)) - } - - override def load(clazz: Symbol) { complete(clazz) } - } - - def transformMixinInfo(tp: Type): Type = tp match { - case ClassInfoType(parents, decls, clazz) if clazz.isPackageClass || !clazz.isJavaDefined => - if (clazz.needsImplClass) - implClass(clazz setFlag lateINTERFACE) // generate an impl class - - val parents1 = parents match { - case Nil => Nil - case hd :: tl => - assert(!hd.typeSymbol.isTrait, clazz) - if (clazz.isTrait) ObjectTpe :: tl - else parents - } - val decls1 = scopeTransform(clazz)( - decls filter (sym => - if (clazz.isInterface) isInterfaceMember(sym) - else sym.isClass || sym.isTerm - ) - ) - ClassInfoType(parents1, decls1, clazz) - case _ => - tp - } - -// Tree transformation -------------------------------------------------------------- - - private class ChangeOwnerAndReturnTraverser(oldowner: Symbol, newowner: Symbol) - extends ChangeOwnerTraverser(oldowner, newowner) { - override def traverse(tree: Tree) { - tree match { - case _: Return => change(tree.symbol) - case _ => - } - super.traverse(tree) - } - } - - private def createMemberDef(tree: Tree, isForInterface: Boolean)(create: Tree => Tree) = { - val isInterfaceTree = tree.isDef && isInterfaceMember(tree.symbol) - if (isInterfaceTree && needsImplMethod(tree.symbol)) - create(tree) - else if (isInterfaceTree == isForInterface) - tree - else - EmptyTree - } - private def implMemberDef(tree: Tree): Tree = createMemberDef(tree, false)(implMethodDef) - private def ifaceMemberDef(tree: Tree): Tree = createMemberDef(tree, true)(t => DefDef(t.symbol, EmptyTree)) - - private def ifaceTemplate(templ: Template): Template = - treeCopy.Template(templ, templ.parents, noSelfType, templ.body map ifaceMemberDef) - - /** Transforms the member tree containing the implementation - * into a member of the impl class. - */ - private def implMethodDef(tree: Tree): Tree = { - val impl = implMethodMap.getOrElse(tree.symbol, abort("implMethod missing for " + tree.symbol)) - - val newTree = if (impl.isErroneous) tree else { // e.g. res/t687 - // SI-5167: Ensure that the tree that we are grafting refers the parameter symbols from the - // new method symbol `impl`, rather than the symbols of the original method signature in - // the trait. `tree setSymbol impl` does *not* suffice! - val DefDef(_, _, _, vparamss, _, _) = tree - val oldSyms = vparamss.flatten.map(_.symbol) - val newSyms = impl.info.paramss.flatten - assert(oldSyms.length == newSyms.length, (oldSyms, impl, impl.info)) - tree.substituteSymbols(oldSyms, newSyms) - } - new ChangeOwnerAndReturnTraverser(newTree.symbol, impl)(newTree setSymbol impl) - } - - /** Add mixin constructor definition - * def $init$(): Unit = () - * to `stats` unless there is already one. - */ - private def addMixinConstructorDef(clazz: Symbol, stats: List[Tree]): List[Tree] = - if (treeInfo.firstConstructor(stats) != EmptyTree) stats - else DefDef(clazz.primaryConstructor, Block(List(), Literal(Constant(())))) :: stats - - private def implTemplate(clazz: Symbol, templ: Template): Template = atPos(templ.pos) { - val templ1 = ( - Template(templ.parents, noSelfType, addMixinConstructorDef(clazz, templ.body map implMemberDef)) - setSymbol clazz.newLocalDummy(templ.pos) - ) - templ1.changeOwner(templ.symbol.owner -> clazz, templ.symbol -> templ1.symbol) - templ1 - } - - def implClassDefs(trees: List[Tree]): List[Tree] = { - trees collect { - case cd: ClassDef if cd.symbol.needsImplClass => - val clazz = implClass(cd.symbol).initialize - ClassDef(clazz, implTemplate(clazz, cd.impl)) - } - } - - /** Add calls to supermixin constructors - * `super[mix].$init$()` - * to tree, which is assumed to be the body of a constructor of class clazz. - */ - private def addMixinConstructorCalls(tree: Tree, clazz: Symbol): Tree = { - def mixinConstructorCall(impl: Symbol): Tree = atPos(tree.pos) { - Apply(Select(This(clazz), impl.primaryConstructor), List()) - } - val mixinConstructorCalls: List[Tree] = { - for (mc <- clazz.mixinClasses.reverse - if mc.hasFlag(lateINTERFACE)) - yield mixinConstructorCall(implClass(mc)) - } - tree match { - case Block(Nil, expr) => - // AnyVal constructor - have to provide a real body so the - // jvm doesn't throw a VerifyError. But we can't add the - // body until now, because the typer knows that Any has no - // constructor and won't accept a call to super.init. - assert((clazz isSubClass AnyValClass) || clazz.info.parents.isEmpty, clazz) - Block(List(Apply(gen.mkSuperInitCall, Nil)), expr) - - case Block(stats, expr) => - // needs `hasSymbolField` check because `supercall` could be a block (named / default args) - val (presuper, supercall :: rest) = stats span (t => t.hasSymbolWhich(_ hasFlag PRESUPER)) - treeCopy.Block(tree, presuper ::: (supercall :: mixinConstructorCalls ::: rest), expr) - } - } - - protected val mixinTransformer = new Transformer { - override def transformStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = - (super.transformStats(stats, exprOwner) ::: - super.transformStats(implClassDefs(stats), exprOwner)) - override def transform(tree: Tree): Tree = { - val sym = tree.symbol - val tree1 = tree match { - case ClassDef(mods, _, _, impl) if sym.needsImplClass => - implClass(sym).initialize // to force lateDEFERRED flags - copyClassDef(tree)(mods = mods | INTERFACE, impl = ifaceTemplate(impl)) - case DefDef(_,_,_,_,_,_) if sym.isClassConstructor && sym.isPrimaryConstructor && sym.owner != ArrayClass => - deriveDefDef(tree)(addMixinConstructorCalls(_, sym.owner)) // (3) - case Template(parents, self, body) => - val parents1 = sym.owner.info.parents map (t => TypeTree(t) setPos tree.pos) - treeCopy.Template(tree, parents1, noSelfType, body) - case This(_) if sym.needsImplClass => - val impl = implClass(sym) - var owner = currentOwner - while (owner != sym && owner != impl) owner = owner.owner; - if (owner == impl) This(impl) setPos tree.pos - else tree - //TODO what about this commented out code? -/* !!! - case Super(qual, mix) => - val mix1 = mix - if (mix == tpnme.EMPTY) mix - else { - val ps = enteringErasure { - sym.info.parents dropWhile (p => p.symbol.name != mix) - } - assert(!ps.isEmpty, tree); - if (ps.head.symbol.needsImplClass) implClass(ps.head.symbol).name - else mix - } - if (sym.needsImplClass) Super(implClass(sym), mix1) setPos tree.pos - else treeCopy.Super(tree, qual, mix1) -*/ - case _ => - tree - } - super.transform(tree1) - } - } -} diff --git a/src/compiler/scala/tools/nsc/transform/CleanUp.scala b/src/compiler/scala/tools/nsc/transform/CleanUp.scala index c29826551b..81df28bc87 100644 --- a/src/compiler/scala/tools/nsc/transform/CleanUp.scala +++ b/src/compiler/scala/tools/nsc/transform/CleanUp.scala @@ -21,16 +21,8 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { val phaseName: String = "cleanup" /* used in GenBCode: collects ClassDef symbols owning a main(Array[String]) method */ - private var entryPoints: List[Symbol] = null - def getEntryPoints: List[Symbol] = { - assert(settings.isBCodeActive, "Candidate Java entry points are collected here only when GenBCode in use.") - entryPoints sortBy ("" + _.fullName) // For predictably ordered error messages. - } - - override def newPhase(prev: scala.tools.nsc.Phase): StdPhase = { - entryPoints = if (settings.isBCodeActive) Nil else null; - super.newPhase(prev) - } + private var entryPoints: List[Symbol] = Nil + def getEntryPoints: List[Symbol] = entryPoints sortBy ("" + _.fullName) // For predictably ordered error messages. protected def newTransformer(unit: CompilationUnit): Transformer = new CleanUpTransformer(unit) @@ -49,7 +41,9 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { clearStatics() val newBody = transformTrees(body) val templ = deriveTemplate(tree)(_ => transformTrees(newStaticMembers.toList) ::: newBody) - try addStaticInits(templ, newStaticInits, localTyper) // postprocess to include static ctors + try + if (newStaticInits.isEmpty) templ + else deriveTemplate(templ)(body => staticConstructor(body, localTyper, templ.pos)(newStaticInits.toList) :: body) finally clearStatics() } private def mkTerm(prefix: String): TermName = unit.freshTermName(prefix) @@ -85,24 +79,6 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { /* ### CREATING THE METHOD CACHE ### */ - def addStaticVariableToClass(forName: TermName, forType: Type, forInit: Tree, isFinal: Boolean): Symbol = { - val flags = PRIVATE | STATIC | SYNTHETIC | ( - if (isFinal) FINAL else 0 - ) - - val varSym = currentClass.newVariable(mkTerm("" + forName), ad.pos, flags.toLong) setInfoAndEnter forType - if (!isFinal) - varSym.addAnnotation(VolatileAttr) - - val varDef = typedPos(ValDef(varSym, forInit)) - newStaticMembers append transform(varDef) - - val varInit = typedPos( REF(varSym) === forInit ) - newStaticInits append transform(varInit) - - varSym - } - def addStaticMethodToClass(forBody: (Symbol, Symbol) => Tree): Symbol = { val methSym = currentClass.newMethod(mkTerm(nme.reflMethodName.toString), ad.pos, STATIC | SYNTHETIC) val params = methSym.newSyntheticValueParams(List(ClassClass.tpe)) @@ -113,9 +89,6 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { methSym } - def fromTypesToClassArrayLiteral(paramTypes: List[Type]): Tree = - ArrayValue(TypeTree(ClassClass.tpe), paramTypes map LIT) - def reflectiveMethodCache(method: String, paramTypes: List[Type]): Symbol = { /* Implementation of the cache is as follows for method "def xyz(a: A, b: B)" (SoftReference so that it does not interfere with classloader garbage collection, @@ -126,7 +99,7 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { var reflPoly$Cache: SoftReference[scala.runtime.MethodCache] = new SoftReference(new EmptyMethodCache()) def reflMethod$Method(forReceiver: JClass[_]): JMethod = { - var methodCache: MethodCache = reflPoly$Cache.find(forReceiver) + var methodCache: StructuralCallSite = indy[StructuralCallSite.bootstrap, "(LA;LB;)Ljava/lang/Object;] if (methodCache eq null) { methodCache = new EmptyMethodCache reflPoly$Cache = new SoftReference(methodCache) @@ -135,41 +108,32 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { if (method ne null) return method else { - method = ScalaRunTime.ensureAccessible(forReceiver.getMethod("xyz", reflParams$Cache)) - reflPoly$Cache = new SoftReference(methodCache.add(forReceiver, method)) + method = ScalaRunTime.ensureAccessible(forReceiver.getMethod("xyz", methodCache.parameterTypes())) + methodCache.add(forReceiver, method) return method } } - */ - - val reflParamsCacheSym: Symbol = - addStaticVariableToClass(nme.reflParamsCacheName, arrayType(ClassClass.tpe), fromTypesToClassArrayLiteral(paramTypes), true) - - def mkNewPolyCache = gen.mkSoftRef(NEW(TypeTree(EmptyMethodCacheClass.tpe))) - val reflPolyCacheSym: Symbol = addStaticVariableToClass(nme.reflPolyCacheName, SoftReferenceClass.tpe, mkNewPolyCache, false) - def getPolyCache = gen.mkCast(fn(REF(reflPolyCacheSym), nme.get), MethodCacheClass.tpe) + invokedynamic is used rather than a static field for the cache to support emitting bodies of methods + in Java 8 interfaces, which don't support private static fields. + */ addStaticMethodToClass((reflMethodSym, forReceiverSym) => { - val methodCache = reflMethodSym.newVariable(mkTerm("methodCache"), ad.pos) setInfo MethodCacheClass.tpe + val methodCache = reflMethodSym.newVariable(mkTerm("methodCache"), ad.pos) setInfo StructuralCallSite.tpe val methodSym = reflMethodSym.newVariable(mkTerm("method"), ad.pos) setInfo MethodClass.tpe + val dummyMethodType = MethodType(NoSymbol.newSyntheticValueParams(paramTypes), AnyTpe) BLOCK( - ValDef(methodCache, getPolyCache), - IF (REF(methodCache) OBJ_EQ NULL) THEN BLOCK( - REF(methodCache) === NEW(TypeTree(EmptyMethodCacheClass.tpe)), - REF(reflPolyCacheSym) === gen.mkSoftRef(REF(methodCache)) - ) ENDIF, - - ValDef(methodSym, (REF(methodCache) DOT methodCache_find)(REF(forReceiverSym))), + ValDef(methodCache, ApplyDynamic(gen.mkAttributedIdent(StructuralCallSite_dummy), LIT(StructuralCallSite_bootstrap) :: LIT(dummyMethodType) :: Nil).setType(StructuralCallSite.tpe)), + ValDef(methodSym, (REF(methodCache) DOT StructuralCallSite_find)(REF(forReceiverSym))), IF (REF(methodSym) OBJ_NE NULL) . THEN (Return(REF(methodSym))) ELSE { - def methodSymRHS = ((REF(forReceiverSym) DOT Class_getMethod)(LIT(method), REF(reflParamsCacheSym))) - def cacheRHS = ((REF(methodCache) DOT methodCache_add)(REF(forReceiverSym), REF(methodSym))) + def methodSymRHS = ((REF(forReceiverSym) DOT Class_getMethod)(LIT(method), (REF(methodCache) DOT StructuralCallSite_getParameterTypes)())) + def cacheAdd = ((REF(methodCache) DOT StructuralCallSite_add)(REF(forReceiverSym), REF(methodSym))) BLOCK( REF(methodSym) === (REF(currentRun.runDefinitions.ensureAccessibleMethod) APPLY (methodSymRHS)), - REF(reflPolyCacheSym) === gen.mkSoftRef(cacheRHS), + cacheAdd, Return(REF(methodSym)) ) } @@ -369,6 +333,8 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { reporter.error(ad.pos, "Cannot resolve overload.") (Nil, NoType) } + case NoType => + abort(ad.symbol.toString) } typedPos { val sym = currentOwner.newValue(mkTerm("qual"), ad.pos) setInfo qual0.tpe @@ -404,11 +370,7 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { } override def transform(tree: Tree): Tree = tree match { - - case _: ClassDef - if (entryPoints != null) && - genBCode.isJavaEntryPoint(tree.symbol, currentUnit) - => + case _: ClassDef if genBCode.isJavaEntryPoint(tree.symbol, currentUnit) => // collecting symbols for entry points here (as opposed to GenBCode where they are used) // has the advantage of saving an additional pass over all ClassDefs. entryPoints ::= tree.symbol @@ -446,7 +408,7 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { * refinement, where the refinement defines a parameter based on a * type variable. */ - case tree: ApplyDynamic => + case tree: ApplyDynamic if tree.symbol.owner.isRefinementClass => transformApplyDynamic(tree) /* Some cleanup transformations add members to templates (classes, traits, etc). @@ -476,46 +438,15 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { /* * This transformation should identify Scala symbol invocations in the tree and replace them - * with references to a static member. Also, whenever a class has at least a single symbol invocation - * somewhere in its methods, a new static member should be created and initialized for that symbol. - * For instance, say we have a Scala class: - * - * class Cls { - * def someSymbol1 = 'Symbolic1 - * def someSymbol2 = 'Symbolic2 - * def sameSymbol1 = 'Symbolic1 - * val someSymbol3 = 'Symbolic3 - * } - * - * After transformation, this class looks like this: - * - * class Cls { - * private <static> var symbol$1: scala.Symbol - * private <static> var symbol$2: scala.Symbol - * private <static> var symbol$3: scala.Symbol - * private val someSymbol3: scala.Symbol - * - * private <static> def <clinit> = { - * symbol$1 = Symbol.apply("Symbolic1") - * symbol$2 = Symbol.apply("Symbolic2") - * } - * - * private def <init> = { - * someSymbol3 = symbol$3 - * } - * - * def someSymbol1 = symbol$1 - * def someSymbol2 = symbol$2 - * def sameSymbol1 = symbol$1 - * val someSymbol3 = someSymbol3 - * } + * with references to a statically cached instance. * * The reasoning behind this transformation is the following. Symbols get interned - they are stored * in a global map which is protected with a lock. The reason for this is making equality checks * quicker. But calling Symbol.apply, although it does return a unique symbol, accesses a locked object, * making symbol access slow. To solve this, the unique symbol from the global symbol map in Symbol - * is accessed only once during class loading, and after that, the unique symbol is in the static - * member. Hence, it is cheap to both reach the unique symbol and do equality checks on it. + * is accessed only once during class loading, and after that, the unique symbol is in the statically + * initialized call site returned by invokedynamic. Hence, it is cheap to both reach the unique symbol + * and do equality checks on it. * * And, finally, be advised - Scala's Symbol literal (scala.Symbol) and the Symbol class of the compiler * have little in common. @@ -523,15 +454,12 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { case Apply(fn @ Select(qual, _), (arg @ Literal(Constant(symname: String))) :: Nil) if treeInfo.isQualifierSafeToElide(qual) && fn.symbol == Symbol_apply && !currentClass.isTrait => - def transformApply = { - // add the symbol name to a map if it's not there already - val rhs = gen.mkMethodCall(Symbol_apply, arg :: Nil) - val staticFieldSym = getSymbolStaticField(tree.pos, symname, rhs, tree) - // create a reference to a static field - val ntree = typedWithPos(tree.pos)(REF(staticFieldSym)) - super.transform(ntree) - } - transformApply + super.transform(treeCopy.ApplyDynamic(tree, atPos(fn.pos)(Ident(SymbolLiteral_dummy).setType(SymbolLiteral_dummy.info)), LIT(SymbolLiteral_bootstrap) :: arg :: Nil)) + + // Drop the TypeApply, which was used in Erasure to make `synchronized { ... } ` erase like `...` + // (and to avoid boxing the argument to the polymorphic `synchronized` method). + case app@Apply(TypeApply(fun, _), args) if fun.symbol == Object_synchronized => + super.transform(treeCopy.Apply(app, fun, args)) // Replaces `Array(Predef.wrapArray(ArrayValue(...).$asInstanceOf[...]), <tag>)` // with just `ArrayValue(...).$asInstanceOf[...]` @@ -548,32 +476,6 @@ abstract class CleanUp extends Statics with Transform with ast.TreeDSL { super.transform(tree) } - /* Returns the symbol and the tree for the symbol field interning a reference to a symbol 'synmname'. - * If it doesn't exist, i.e. the symbol is encountered the first time, - * it creates a new static field definition and initialization and returns it. - */ - private def getSymbolStaticField(pos: Position, symname: String, rhs: Tree, tree: Tree): Symbol = { - symbolsStoredAsStatic.getOrElseUpdate(symname, { - val theTyper = typer.atOwner(tree, currentClass) - - // create a symbol for the static field - val stfieldSym = ( - currentClass.newVariable(mkTerm("symbol$"), pos, PRIVATE | STATIC | SYNTHETIC | FINAL) - setInfoAndEnter SymbolClass.tpe - ) - - // create field definition and initialization - val stfieldDef = theTyper.typedPos(pos)(ValDef(stfieldSym, rhs)) - val stfieldInit = theTyper.typedPos(pos)(REF(stfieldSym) === rhs) - - // add field definition to new defs - newStaticMembers append stfieldDef - newStaticInits append stfieldInit - - stfieldSym - }) - } - } // CleanUpTransformer } diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala index b2aac587eb..231a3e4c64 100644 --- a/src/compiler/scala/tools/nsc/transform/Constructors.scala +++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala @@ -6,15 +6,14 @@ package scala.tools.nsc package transform -import scala.collection.{ mutable, immutable } -import scala.collection.mutable.ListBuffer +import scala.collection.mutable import scala.reflect.internal.util.ListOfNil import symtab.Flags._ /** This phase converts classes with parameters into Java-like classes with * fields, which are assigned to from constructors. */ -abstract class Constructors extends Statics with Transform with ast.TreeDSL { +abstract class Constructors extends Statics with Transform with TypingTransformers with ast.TreeDSL { import global._ import definitions._ @@ -27,8 +26,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { private val guardedCtorStats: mutable.Map[Symbol, List[Tree]] = perRunCaches.newMap[Symbol, List[Tree]]() private val ctorParams: mutable.Map[Symbol, List[Symbol]] = perRunCaches.newMap[Symbol, List[Symbol]]() - class ConstructorTransformer(unit: CompilationUnit) extends Transformer { - + class ConstructorTransformer(unit: CompilationUnit) extends TypingTransformer(unit) { /* * Inspect for obvious out-of-order initialization; concrete, eager vals or vars, declared in this class, * for which a reference to the member precedes its definition. @@ -75,14 +73,17 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { override def transform(tree: Tree): Tree = { tree match { - case cd @ ClassDef(mods0, name0, tparams0, impl0) if !cd.symbol.isInterface && !isPrimitiveValueClass(cd.symbol) => + case cd @ ClassDef(mods0, name0, tparams0, impl0) if !isPrimitiveValueClass(cd.symbol) && cd.symbol.primaryConstructor != NoSymbol => if(cd.symbol eq AnyValClass) { cd } else { checkUninitializedReads(cd) val tplTransformer = new TemplateTransformer(unit, impl0) - treeCopy.ClassDef(cd, mods0, name0, tparams0, tplTransformer.transformed) + tplTransformer.localTyper = this.localTyper + tplTransformer.atOwner(impl0, cd.symbol) { + treeCopy.ClassDef(cd, mods0, name0, tparams0, tplTransformer.transformed) + } } case _ => super.transform(tree) @@ -121,15 +122,15 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * What trees can be visited at this point? * To recap, by the time the constructors phase runs, local definitions have been hoisted out of their original owner. * Moreover, by the time elision is about to happen, the `intoConstructors` rewriting - * of template-level statements has taken place (the resulting trees can be found in `constrStatBuf`). + * of template-level statements has taken place (the resulting trees can be found in `constructorStats`). * * That means: * - * - nested classes are to be found in `defBuf` + * - nested classes are to be found in `defs` * - * - value and method definitions are also in `defBuf` and none of them contains local methods or classes. + * - value and method definitions are also in `defs` and none of them contains local methods or classes. * - * - auxiliary constructors are to be found in `auxConstructorBuf` + * - auxiliary constructors are to be found in `auxConstructors` * * Coming back to the question which trees may contain accesses: * @@ -148,62 +149,56 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * (the primary constructor) into a dedicated synthetic method that an anon-closure may invoke, as required by DelayedInit. * */ - private trait OmittablesHelper { self: TemplateTransformer => - - /* - * Initially populated with all elision candidates. - * Trees are traversed, and those candidates are removed which are actually needed. - * After that, `omittables` doesn't shrink anymore: each symbol it contains can be unlinked from clazz.info.decls. - */ - val omittables = mutable.Set.empty[Symbol] - - def populateOmittables() { - - omittables.clear() - - if(isDelayedInitSubclass) { - return - } - - def isParamCandidateForElision(sym: Symbol) = (sym.isParamAccessor && sym.isPrivateLocal) - def isOuterCandidateForElision(sym: Symbol) = (sym.isOuterAccessor && sym.owner.isEffectivelyFinal && !sym.isOverridingSymbol) - - val paramCandidatesForElision: Set[ /*Field*/ Symbol] = (clazz.info.decls.toSet filter isParamCandidateForElision) - val outerCandidatesForElision: Set[ /*Method*/ Symbol] = (clazz.info.decls.toSet filter isOuterCandidateForElision) - - omittables ++= paramCandidatesForElision - omittables ++= outerCandidatesForElision - - val bodyOfOuterAccessor: Map[Symbol, DefDef] = - defBuf.collect { case dd: DefDef if outerCandidatesForElision(dd.symbol) => dd.symbol -> dd }.toMap + private trait OmittablesHelper { + def computeOmittableAccessors(clazz: Symbol, defs: List[Tree], auxConstructors: List[Tree]): Set[Symbol] = { + val decls = clazz.info.decls.toSet + val isEffectivelyFinal = clazz.isEffectivelyFinal + + // Initially populated with all elision candidates. + // Trees are traversed, and those candidates are removed which are actually needed. + // After that, `omittables` doesn't shrink anymore: each symbol it contains can be unlinked from clazz.info.decls. + // + // Note: elision of outer reference is based on a class-wise analysis, if a class might have subclasses, + // it doesn't work. For example, `LocalParent` retains the outer reference in: + // + // class Outer { def test = {class LocalParent; class LocalChild extends LocalParent } } + // + // See run/t9408.scala for related test cases. + def omittableParamAcc(sym: Symbol) = sym.isParamAccessor && sym.isPrivateLocal + def omittableOuterAcc(sym: Symbol) = isEffectivelyFinal && sym.isOuterAccessor && !sym.isOverridingSymbol + val omittables = mutable.Set.empty[Symbol] ++ (decls filter (sym => omittableParamAcc(sym) || omittableOuterAcc(sym))) // the closure only captures isEffectivelyFinal // no point traversing further once omittables is empty, all candidates ruled out already. object detectUsages extends Traverser { - private def markUsage(sym: Symbol) { - omittables -= debuglogResult("omittables -= ")(sym) - // recursive call to mark as needed the field supporting the outer-accessor-method. - bodyOfOuterAccessor get sym foreach (this traverse _.rhs) - } - override def traverse(tree: Tree): Unit = if (omittables.nonEmpty) { - def sym = tree.symbol - tree match { - // don't mark as "needed" the field supporting this outer-accessor, ie not just yet. - case _: DefDef if outerCandidatesForElision(sym) => () - case _: Select if omittables(sym) => markUsage(sym) ; super.traverse(tree) - case _ => super.traverse(tree) + lazy val bodyOfOuterAccessor = defs.collect{ case dd: DefDef if omittableOuterAcc(dd.symbol) => dd.symbol -> dd.rhs }.toMap + + override def traverse(tree: Tree): Unit = + if (omittables.nonEmpty) { + def sym = tree.symbol + tree match { + case _: DefDef if (sym.owner eq clazz) && omittableOuterAcc(sym) => // don't mark as "needed" the field supporting this outer-accessor (not just yet) + case _: Select if omittables(sym) => omittables -= sym // mark usage + bodyOfOuterAccessor get sym foreach traverse // recurse to mark as needed the field supporting the outer-accessor-method + super.traverse(tree) + case _ => super.traverse(tree) + } } - } - def walk(xs: Seq[Tree]) = xs.iterator foreach traverse - } - if (omittables.nonEmpty) { - detectUsages walk defBuf - detectUsages walk auxConstructorBuf } - } - def mustBeKept(sym: Symbol) = !omittables(sym) + if (omittables.nonEmpty) + (defs.iterator ++ auxConstructors.iterator) foreach detectUsages.traverse + + omittables.toSet + } } // OmittablesHelper + trait ConstructorTransformerBase { + def unit: CompilationUnit + def impl: Template + def clazz: Symbol + def localTyper: analyzer.Typer + } + /* * TemplateTransformer rewrites DelayedInit subclasses. * The list of statements that will end up in the primary constructor can be split into: @@ -248,10 +243,8 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * @return the DefDef for (c) above * * */ - private trait DelayedInitHelper { self: TemplateTransformer => - + private trait DelayedInitHelper extends ConstructorTransformerBase { private def delayedEndpointDef(stats: List[Tree]): DefDef = { - val methodName = currentUnit.freshTermName("delayedEndpoint$" + clazz.fullNameAsName('$').toString + "$") val methodSym = clazz.newMethod(methodName, impl.pos, SYNTHETIC | FINAL) methodSym setInfoAndEnter MethodType(Nil, UnitTpe) @@ -310,36 +303,30 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { satelliteClass.asInstanceOf[ClassDef] } - private def delayedInitCall(closure: Tree) = localTyper.typedPos(impl.pos) { - gen.mkMethodCall(This(clazz), delayedInitMethod, Nil, List(New(closure.symbol.tpe, This(clazz)))) - } + /** For a DelayedInit subclass, wrap remainingConstrStats into a DelayedInit closure. */ + def delayedInitDefsAndConstrStats(defs: List[Tree], remainingConstrStats: List[Tree]): (List[Tree], List[Tree]) = { + val delayedHook = delayedEndpointDef(remainingConstrStats) + val delayedHookSym = delayedHook.symbol.asInstanceOf[MethodSymbol] - def rewriteDelayedInit() { - /* XXX This is not correct: remainingConstrStats.nonEmpty excludes too much, - * but excluding it includes too much. The constructor sequence being mimicked - * needs to be reproduced with total fidelity. - * - * See test case files/run/bug4680.scala, the output of which is wrong in many - * particulars. - */ - val needsDelayedInit = (isDelayedInitSubclass && remainingConstrStats.nonEmpty) - - if (needsDelayedInit) { - val delayedHook: DefDef = delayedEndpointDef(remainingConstrStats) - defBuf += delayedHook - val hookCallerClass = { - // transform to make the closure-class' default constructor assign the outer instance to its param-accessor field. - val drillDown = new ConstructorTransformer(unit) - drillDown transform delayedInitClosure(delayedHook.symbol.asInstanceOf[MethodSymbol]) - } - defBuf += hookCallerClass - remainingConstrStats = delayedInitCall(hookCallerClass) :: Nil + // transform to make the closure-class' default constructor assign the outer instance to its param-accessor field. + val hookCallerClass = (new ConstructorTransformer(unit)) transform delayedInitClosure(delayedHookSym) + val delayedInitCall = localTyper.typedPos(impl.pos) { + gen.mkMethodCall(This(clazz), delayedInitMethod, Nil, List(New(hookCallerClass.symbol.tpe, This(clazz)))) } + + (List(delayedHook, hookCallerClass), List(delayedInitCall)) } } // DelayedInitHelper - private trait GuardianOfCtorStmts { self: TemplateTransformer => + private trait GuardianOfCtorStmts extends ConstructorTransformerBase { + def primaryConstrParams: List[Symbol] + def usesSpecializedField: Boolean + + lazy 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. + lazy val guardSpecializedFieldInit = (hasSpecializedFieldsSym != NoSymbol) && !clazz.hasFlag(SPECIALIZED) /* Return a single list of statements, merging the generic class constructor with the * specialized stats. The original statements are retyped in the current class, and @@ -347,7 +334,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * `specializedStats` are replaced by the specialized assignment. */ private def mergeConstructors(genericClazz: Symbol, originalStats: List[Tree], specializedStats: List[Tree]): List[Tree] = { - val specBuf = new ListBuffer[Tree] + val specBuf = new mutable.ListBuffer[Tree] specBuf ++= specializedStats def specializedAssignFor(sym: Symbol): Option[Tree] = @@ -375,7 +362,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { } log("merging: " + originalStats.mkString("\n") + "\nwith\n" + specializedStats.mkString("\n")) - val res = for (s <- originalStats; stat = s.duplicate) yield { + for (s <- originalStats; stat = s.duplicate) yield { log("merge: looking at " + stat) val stat1 = stat match { case Assign(sel @ Select(This(_), field), _) => @@ -388,9 +375,9 @@ 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 @@ -405,9 +392,8 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { } else stat1 } - if (specBuf.nonEmpty) - println("residual specialized constructor statements: " + specBuf) - res +// if (specBuf.nonEmpty) +// println("residual specialized constructor statements: " + specBuf) } /* Add an 'if' around the statements coming after the super constructor. This @@ -427,16 +413,16 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { // postfix = postfix.tail // } - if (shouldGuard && usesSpecializedField && stats.nonEmpty) { + if (guardSpecializedFieldInit && 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) @@ -459,39 +445,31 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { } // GuardianOfCtorStmts private class TemplateTransformer(val unit: CompilationUnit, val impl: Template) - extends StaticsTransformer + extends TypingTransformer(unit) + with StaticsTransformer with DelayedInitHelper with OmittablesHelper - with GuardianOfCtorStmts { - - val clazz = impl.symbol.owner // the transformed class - 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) - } + with GuardianOfCtorStmts + with fields.CheckedAccessorTreeSynthesis + { + protected def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) + + val clazz = impl.symbol.owner // the transformed class + + val isDelayedInitSubclass = clazz isSubClass DelayedInitClass + + private val stats = impl.body // the transformed template body + + // find and dissect primary constructor + private 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) } - import constrInfo._ - // The parameter accessor fields which are members of the class - val paramAccessors = clazz.constrParamAccessors + + def primaryConstrParams = _primaryConstrParams + def usesSpecializedField = intoConstructor.usesSpecializedField // The constructor parameter corresponding to an accessor def parameter(acc: Symbol): Symbol = parameterNamed(acc.unexpandedName.getterName) @@ -501,27 +479,26 @@ 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) = ( @@ -530,26 +507,27 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { !sym.isSetter ) - private def possiblySpecialized(s: Symbol) = specializeTypes.specializedTypeVars(s).nonEmpty - /* - * whether `sym` denotes a param-accessor (ie a field) that fulfills all of: + * whether `sym` denotes a param-accessor (ie in a class a PARAMACCESSOR field, or in a trait a method with same flag) + * that fulfills all of: * (a) has stationary value, ie the same value provided via the corresponding ctor-arg; and * (b) isn't subject to specialization. We might be processing statements for: * (b.1) the constructor in the generic (super-)class; or * (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) && !specializeTypes.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 - if (canBeSupplanted(tree.symbol)) - gen.mkAttributedIdent(parameter(tree.symbol.accessed)) setPos tree.pos - else if (tree.symbol.outerSource == clazz && !clazz.isImplClass) + // println(s"to param ref in $clazz for ${tree.symbol} ${tree.symbol.debugFlagString} / ${tree.symbol.outerSource} / ${canBeSupplanted(tree.symbol)}") + if (clazz.isTrait && !(tree.symbol hasAllFlags (ACCESSOR | PARAMACCESSOR))) + super.transform(tree) + else if (canBeSupplanted(tree.symbol)) + gen.mkAttributedIdent(parameter(tree.symbol)) setPos tree.pos + else if (tree.symbol.outerSource == clazz && !isDelayedInitSubclass) gen.mkAttributedIdent(parameterNamed(nme.OUTER)) setPos tree.pos else super.transform(tree) @@ -558,8 +536,8 @@ 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` - if (possiblySpecialized(tree.symbol)) { + case Select(_, _) if guardSpecializedFieldInit => // reasoning behind this guard in the docu of `usesSpecializedField` + if (specializeTypes.possiblySpecialized(tree.symbol)) { usesSpecializedField = true } super.transform(tree) @@ -568,23 +546,20 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { super.transform(tree) } + // Move tree into constructor, take care of changing owner from `oldOwner` to `newOwner` (the primary constructor symbol) + def apply(oldOwner: Symbol, newOwner: Symbol)(tree: Tree) = + if (tree eq EmptyTree) tree + else transform(tree.changeOwner(oldOwner -> newOwner)) } - 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 - } + // Assign `rhs` to class field / trait setter `assignSym` + def mkAssign(assignSym: Symbol, rhs: Tree): Tree = + localTyper.typedPos(assignSym.pos) { + val qual = Select(This(clazz), assignSym) + if (assignSym.isSetter) Apply(qual, List(rhs)) + else Assign(qual, rhs) + } - // Create an assignment to class field `to` with rhs `from` - def mkAssign(to: Symbol, from: Tree): Tree = - localTyper.typedPos(to.pos) { Assign(Select(This(clazz), to), from) } // Create code to copy parameter to parameter accessor field. // If parameter is $outer, check that it is not null so that we NPE @@ -594,139 +569,230 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { val result = mkAssign(to, Ident(from)) if (from.name != nme.OUTER || - from.tpe.typeSymbol.isPrimitiveValueClass) result + from.tpe.typeSymbol.isPrimitiveValueClass) result else localTyper.typedPos(to.pos) { // `throw null` has the same effect as `throw new NullPointerException`, see JVM spec on instruction `athrow` - IF (from OBJ_EQ NULL) THEN Throw(gen.mkZero(ThrowableTpe)) ELSE result + IF(from OBJ_EQ NULL) THEN Throw(gen.mkZero(ThrowableTpe)) ELSE result } } - // The list of definitions that go into class - val defBuf = new ListBuffer[Tree] - - // The auxiliary constructors, separate from the defBuf since they should - // follow the primary constructor - val auxConstructorBuf = new ListBuffer[Tree] - - // The list of statements that go into the constructor after and including the superclass constructor call - val constrStatBuf = new ListBuffer[Tree] + /** Triage definitions and statements in this template into the following categories. + * The primary constructor is treated separately, as it is assembled in part from these pieces. + * + * - `defs`: definitions that go into class + * - `auxConstrs`: auxiliary constructors, separate from the defs as they should follow the primary constructor + * - `constrPrefix`: early initializer statements that go into constructor before the superclass constructor call + * - `constrStats`: statements that go into the constructor after and including the superclass constructor call + * - `classInitStats`: statements that go into the class initializer + */ + class Triage { + private val defBuf, auxConstructorBuf, constrPrefixBuf, constrStatBuf, classInitStatBuf = new mutable.ListBuffer[Tree] + + triage() + + val defs = defBuf.toList + val auxConstructors = auxConstructorBuf.toList + val constructorPrefix = constrPrefixBuf.toList + val constructorStats = constrStatBuf.toList + val classInitStats = classInitStatBuf.toList + + private def triage() = { + // Constant typed vals are not memoized. + def memoizeValue(sym: Symbol) = !sym.info.resultType.isInstanceOf[ConstantType] + + // The early initialized field definitions of the class (these are the class members) + val presupers = treeInfo.preSuperFields(stats) + + // generate code to copy pre-initialized fields + for (stat <- primaryConstrBody.stats) { + constrStatBuf += stat + stat match { + case ValDef(mods, name, _, _) if mods.hasFlag(PRESUPER) => // TODO trait presupers + // stat is the constructor-local definition of the field value + val fields = presupers filter (_.getterName == name) + assert(fields.length == 1, s"expected exactly one field by name $name in $presupers of $clazz's early initializers") + val to = fields.head.symbol + + if (memoizeValue(to)) constrStatBuf += mkAssign(to, Ident(stat.symbol)) + case _ => + } + } - // The list of early initializer statements that go into constructor before the superclass constructor call - val constrPrefixBuf = new ListBuffer[Tree] + val primaryConstrSym = primaryConstr.symbol + + for (stat <- stats) { + val statSym = stat.symbol + + // Move the RHS of a ValDef to the appropriate part of the ctor. + // If the val 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, assignSym: Symbol): Unit = { + val initializingRhs = + if ((assignSym eq NoSymbol) || statSym.isLazy) EmptyTree // not memoized, or effect delayed (for lazy val) + else if (!mods.hasStaticFlag) intoConstructor(statSym, primaryConstrSym)(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(assignSym, initializingRhs) + } + } - // The early initialized field definitions of the class (these are the class members) - val presupers = treeInfo.preSuperFields(stats) + stat match { + // recurse on class definition, store in defBuf + case _: ClassDef => + if (statSym.isInterface) defBuf += stat + else defBuf += new ConstructorTransformer(unit).transform(stat) + + // primary constructor is already tracked as `primaryConstr` + // non-primary constructors go to auxConstructorBuf + case _: DefDef if statSym.isConstructor => + if (statSym ne primaryConstrSym) auxConstructorBuf += stat + + // 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 vd: ValDef => + if (vd.rhs eq EmptyTree) { defBuf += vd } + else { + val emitField = memoizeValue(statSym) + + if (emitField) { + moveEffectToCtor(vd.mods, vd.rhs, statSym) + defBuf += deriveValDef(stat)(_ => EmptyTree) + } + } - // The list of statements that go into the class initializer - val classInitStatBuf = new ListBuffer[Tree] + case dd: DefDef => + // either move the RHS to ctor (for getter of stored field) or just drop it (for corresponding setter) + def shouldMoveRHS = + clazz.isTrait && statSym.isAccessor && !statSym.isLazy && (statSym.isSetter || memoizeValue(statSym)) - // generate code to copy pre-initialized fields - for (stat <- constrBody.stats) { - constrStatBuf += stat - stat match { - 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) - val to = fields.head.symbol - if (!to.tpe.isInstanceOf[ConstantType]) - constrStatBuf += mkAssign(to, Ident(stat.symbol)) - case _ => - } - } + if ((dd.rhs eq EmptyTree) || !shouldMoveRHS) { defBuf += dd } + else { + if (statSym.isGetter) moveEffectToCtor(dd.mods, dd.rhs, statSym.asTerm.referenced orElse statSym.setterIn(clazz)) + defBuf += deriveDefDef(stat)(_ => EmptyTree) + } - // 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 => - // 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) + // all other statements go into the constructor + case _ => + constrStatBuf += intoConstructor(impl.symbol, primaryConstrSym)(stat) } - 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) - } - - populateOmittables() - - // Initialize all parameters fields that must be kept. - val paramInits = paramAccessors filter mustBeKept map { acc => - // Check for conflicting symbol amongst parents: see bug #1960. - // It would be better to mangle the constructor parameter name since - // it can only be used internally, but I think we need more robust name - // mangling before we introduce more of it. - val conflict = clazz.info.nonPrivateMember(acc.name) filter (s => s.isGetter && !s.isOuterField && s.enclClass.isTrait) - if (conflict ne NoSymbol) - reporter.error(acc.pos, "parameter '%s' requires field but conflicts with %s".format(acc.name, conflict.fullLocationString)) - - copyParam(acc, parameter(acc)) - } - - /* Return a pair consisting of (all statements up to and including superclass and trait constr calls, rest) */ - def splitAtSuper(stats: List[Tree]) = { - def isConstr(tree: Tree): Boolean = tree match { - case Block(_, expr) => isConstr(expr) // SI-6481 account for named argument blocks - case _ => (tree.symbol ne null) && tree.symbol.isConstructor } - val (pre, rest0) = stats span (!isConstr(_)) - val (supercalls, rest) = rest0 span (isConstr(_)) - (pre ::: supercalls, rest) } - val (uptoSuperStats, remainingConstrStats0) = splitAtSuper(constrStatBuf.toList) - var remainingConstrStats = remainingConstrStats0 - - rewriteDelayedInit() + def transformed = { + val triage = new Triage; import triage._ + + // omit unused outers + val omittableAccessor: Set[Symbol] = + if (isDelayedInitSubclass) Set.empty + else computeOmittableAccessors(clazz, defs, auxConstructors) + + // TODO: this should omit fields for non-memoized (constant-typed, unit-typed vals need no storage -- + // all the action is in the getter) + def omittableSym(sym: Symbol) = omittableAccessor(sym) + def omittableStat(stat: Tree) = omittableSym(stat.symbol) + + // The parameter accessor fields which are members of the class + val paramAccessors = + if (clazz.isTrait) clazz.info.decls.toList.filter(sym => sym.hasAllFlags(STABLE | PARAMACCESSOR)) // since a trait does not have constructor parameters (yet), these can only come from lambdalift -- right? + else clazz.constrParamAccessors + + // Initialize all parameters fields that must be kept. + val paramInits = paramAccessors filterNot omittableSym map { acc => + // Check for conflicting field mixed in for a val/var defined in a parent trait (neg/t1960.scala). + // Since the fields phase has already mixed in fields, we can just look for + // an existing decl with the local variant of our paramaccessor's name. + // + // TODO: mangle the constructor parameter name (it can only be used internally), though we probably first need more robust name mangling + + // sometimes acc is a field with a local name (when it's a val/var constructor param) --> exclude the `acc` itself when looking for conflicting decl + // sometimes it's not (just a constructor param) --> any conflicting decl is a problem + val conflict = clazz.info.decl(acc.name.localName).filter(sym => sym ne acc) + if (conflict ne NoSymbol) { + val orig = exitingTyper(clazz.info.nonPrivateMember(acc.name).filter(_ hasFlag ACCESSOR)) + reporter.error(acc.pos, s"parameter '${acc.name}' requires field but conflicts with ${(orig orElse conflict).fullLocationString}") + } - // Assemble final constructor - defBuf += deriveDefDef(constr)(_ => - treeCopy.Block( - constrBody, - paramInits ::: constrPrefixBuf.toList ::: uptoSuperStats ::: - guardSpecializedInitializer(remainingConstrStats), - constrBody.expr)) + val accSetter = + if (clazz.isTrait) acc.setterIn(clazz, hasExpandedName = true) + else acc - // Followed by any auxiliary constructors - defBuf ++= auxConstructorBuf + copyParam(accSetter, parameter(acc)) + } - // Unlink all fields that can be dropped from class scope - for (sym <- clazz.info.decls ; if !mustBeKept(sym)) - clazz.info.decls unlink sym + // Return a pair consisting of (all statements up to and including superclass and trait constr calls, rest) + def splitAtSuper(stats: List[Tree]) = { + def isConstr(tree: Tree): Boolean = tree match { + case Block(_, expr) => isConstr(expr) // SI-6481 account for named argument blocks + case _ => (tree.symbol ne null) && tree.symbol.isConstructor + } + val (pre, rest0) = stats span (!isConstr(_)) + val (supercalls, rest) = rest0 span (isConstr(_)) + (pre ::: supercalls, rest) + } - // 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) + val (uptoSuperStats, remainingConstrStats) = splitAtSuper(constructorStats) + + /* TODO: XXX This condition (`isDelayedInitSubclass && remainingConstrStats.nonEmpty`) is not correct: + * remainingConstrStats.nonEmpty excludes too much, + * but excluding it includes too much. The constructor sequence being mimicked + * needs to be reproduced with total fidelity. + * + * See test case files/run/bug4680.scala, the output of which is wrong in many + * particulars. + */ + val (delayedHookDefs, remainingConstrStatsDelayedInit) = + if (isDelayedInitSubclass && remainingConstrStats.nonEmpty) delayedInitDefsAndConstrStats(defs, remainingConstrStats) + else (Nil, remainingConstrStats) + + // Assemble final constructor + val primaryConstructor = deriveDefDef(primaryConstr)(_ => { + treeCopy.Block( + primaryConstrBody, + paramInits ::: constructorPrefix ::: uptoSuperStats ::: guardSpecializedInitializer(remainingConstrStatsDelayedInit), + primaryConstrBody.expr) + }) + + if (omittableAccessor.exists(_.isOuterField) && !constructorStats.exists(_.exists { case i: Ident if i.symbol.isOuterParam => true; case _ => false})) + primaryConstructor.symbol.updateAttachment(OuterArgCanBeElided) + + val constructors = primaryConstructor :: auxConstructors + + // Unlink all fields that can be dropped from class scope + // Iterating on toList is cheaper (decls.filter does a toList anyway) + val decls = clazz.info.decls + decls.toList.filter(omittableSym).foreach(decls.unlink) + + // Eliminate all field/accessor definitions that can be dropped from template + // We never eliminate delayed hooks or the constructors, so, only filter `defs`. + val prunedStats = (defs filterNot omittableStat) ::: delayedHookDefs ::: constructors + + val statsWithInitChecks = + if (settings.checkInit) { + val addChecks = new SynthInitCheckedAccessorsIn(currentOwner) + prunedStats mapConserve { + case dd: DefDef => deriveDefDef(dd)(addChecks.wrapRhsWithInitChecks(dd.symbol)) + case stat => stat + } + } else prunedStats + // Add the static initializers + if (classInitStats.isEmpty) deriveTemplate(impl)(_ => statsWithInitChecks) + else { + val staticCtor = staticConstructor(statsWithInitChecks, localTyper, impl.pos)(classInitStats) + deriveTemplate(impl)(_ => staticCtor :: statsWithInitChecks) + } + } } // TemplateTransformer - } diff --git a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala index 8e323de623..034cf118d7 100644 --- a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala +++ b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala @@ -4,35 +4,21 @@ package transform import symtab._ import Flags._ import scala.collection._ -import scala.language.postfixOps -import scala.reflect.internal.Symbols -import scala.collection.mutable.LinkedHashMap /** - * This transformer is responsible for preparing lambdas for runtime, by either translating to anonymous classes - * or to a tree that will be convereted to invokedynamic by the JVM 1.8+ backend. - * - * The main assumption it makes is that a lambda {args => body} has been turned into - * {args => liftedBody()} where lifted body is a top level method that implements the body of the lambda. - * Currently Uncurry is responsible for that transformation. - * - * From a lambda, Delambdafy will create: - * - * Under -target:jvm-1.7 and below: - * - * 1) a new top level class that - a) has fields and a constructor taking the captured environment (including possibly the "this" - * reference) - * b) an apply method that calls the target method - * c) if needed a bridge method for the apply method - * 2) an instantiation of the newly created class which replaces the lambda - * - * Under -target:jvm-1.8 with GenBCode: - * - * 1) An application of the captured arguments to a fictional symbol representing the lambda factory. - * This will be translated by the backed into an invokedynamic using a bootstrap method in JDK8's `LambdaMetaFactory`. - * The captured arguments include `this` if `liftedBody` is unable to be made STATIC. - */ + * This transformer is responsible for preparing Function nodes for runtime, + * by translating to a tree that will be converted to an invokedynamic by the backend. + * + * The main assumption it makes is that a Function {args => body} has been turned into + * {args => liftedBody()} where lifted body is a top level method that implements the body of the function. + * Currently Uncurry is responsible for that transformation. + * + * From this shape of Function, Delambdafy will create: + * + * An application of the captured arguments to a fictional symbol representing the lambda factory. + * This will be translated by the backed into an invokedynamic using a bootstrap method in JDK8's `LambdaMetaFactory`. + * The captured arguments include `this` if `liftedBody` is unable to be made STATIC. + */ abstract class Delambdafy extends Transform with TypingTransformers with ast.TreeDSL with TypeAdaptingTransformer { import global._ import definitions._ @@ -42,6 +28,19 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre /** the following two members override abstract members in Transform */ val phaseName: String = "delambdafy" + final case class LambdaMetaFactoryCapable(target: Symbol, arity: Int, functionalInterface: Symbol, sam: Symbol, isSerializable: Boolean, addScalaSerializableMarker: Boolean) + + /** + * Get the symbol of the target lifted lambda body method from a function. I.e. if + * the function is {args => anonfun(args)} then this method returns anonfun's symbol + */ + private def targetMethod(fun: Function): Symbol = fun match { + case Function(_, Apply(target, _)) => target.symbol + case _ => + // any other shape of Function is unexpected at this point + abort(s"could not understand function with tree $fun") + } + override def newPhase(prev: scala.tools.nsc.Phase): StdPhase = { if (settings.Ydelambdafy.value == "method") new Phase(prev) else new SkipPhase(prev) @@ -54,433 +53,250 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre protected def newTransformer(unit: CompilationUnit): Transformer = new DelambdafyTransformer(unit) - class DelambdafyTransformer(unit: CompilationUnit) extends TypingTransformer(unit) with TypeAdapter { - private val lambdaClassDefs = new mutable.LinkedHashMap[Symbol, List[Tree]] withDefaultValue Nil - - - val typer = localTyper - - // we need to know which methods refer to the 'this' reference so that we can determine - // which lambdas need access to it - val thisReferringMethods: Set[Symbol] = { - val thisReferringMethodsTraverser = new ThisReferringMethodsTraverser() - thisReferringMethodsTraverser traverse unit.body - val methodReferringMap = thisReferringMethodsTraverser.liftedMethodReferences - val referrers = thisReferringMethodsTraverser.thisReferringMethods - // recursively find methods that refer to 'this' directly or indirectly via references to other methods - // for each method found add it to the referrers set - def refersToThis(symbol: Symbol): Boolean = { - if (referrers contains symbol) true - else if (methodReferringMap(symbol) exists refersToThis) { - // add it early to memoize - debuglog(s"$symbol indirectly refers to 'this'") - referrers += symbol - true - } else false + class DelambdafyTransformer(unit: CompilationUnit) extends TypingTransformer(unit) { + // we need to know which methods refer to the 'this' reference so that we can determine which lambdas need access to it + // TODO: this looks expensive, so I made it a lazy val. Can we make it more pay-as-you-go / optimize for common shapes? + private[this] lazy val methodReferencesThis: Set[Symbol] = + (new ThisReferringMethodsTraverser).methodReferencesThisIn(unit.body) + + private def mkLambdaMetaFactoryCall(fun: Function, target: Symbol, functionalInterface: Symbol, samUserDefined: Symbol, isSpecialized: Boolean): Tree = { + val pos = fun.pos + def isSelfParam(p: Symbol) = p.isSynthetic && p.name == nme.SELF + val hasSelfParam = isSelfParam(target.firstParam) + + val allCapturedArgRefs = { + // find which variables are free in the lambda because those are captures that need to be + // passed into the constructor of the anonymous function class + val captureArgs = FreeVarTraverser.freeVarsOf(fun).iterator.map(capture => + gen.mkAttributedRef(capture) setPos pos + ).toList + + if (!hasSelfParam) captureArgs.filterNot(arg => isSelfParam(arg.symbol)) + else if (currentMethod.hasFlag(Flags.STATIC)) captureArgs + else (gen.mkAttributedThis(fun.symbol.enclClass) setPos pos) :: captureArgs } - methodReferringMap.keys foreach refersToThis - referrers - } - - // the result of the transformFunction method. - sealed abstract class TransformedFunction - // A class definition for the lambda, an expression instantiating the lambda class - case class DelambdafyAnonClass(lambdaClassDef: ClassDef, newExpr: Tree) extends TransformedFunction - case class InvokeDynamicLambda(tree: Apply) extends TransformedFunction - - private val boxingBridgeMethods = mutable.ArrayBuffer[Tree]() - - // here's the main entry point of the transform - override def transform(tree: Tree): Tree = tree match { - // the main thing we care about is lambdas - case fun @ Function(_, _) => - transformFunction(fun) match { - case DelambdafyAnonClass(lambdaClassDef, newExpr) => - // a lambda becomes a new class, an instantiation expression - val pkg = lambdaClassDef.symbol.owner - - // we'll add the lambda class to the package later - lambdaClassDefs(pkg) = lambdaClassDef :: lambdaClassDefs(pkg) - - super.transform(newExpr) - case InvokeDynamicLambda(apply) => - // ... or an invokedynamic call - super.transform(apply) - } - case Template(_, _, _) => - try { - // during this call boxingBridgeMethods will be populated from the Function case - val Template(parents, self, body) = super.transform(tree) - Template(parents, self, body ++ boxingBridgeMethods) - } finally boxingBridgeMethods.clear() - case _ => super.transform(tree) - } - // this entry point is aimed at the statements in the compilation unit. - // after working on the entire compilation until we'll have a set of - // new class definitions to add to the top level - override def transformStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = { - // Need to remove from the lambdaClassDefs map: there may be multiple PackageDef for the same - // package when defining a package object. We only add the lambda class to one. See SI-9097. - super.transformStats(stats, exprOwner) ++ lambdaClassDefs.remove(exprOwner).getOrElse(Nil) - } - - private def optionSymbol(sym: Symbol): Option[Symbol] = if (sym.exists) Some(sym) else None - - // turns a lambda into a new class def, a New expression instantiating that class - private def transformFunction(originalFunction: Function): TransformedFunction = { - val functionTpe = originalFunction.tpe - val targs = functionTpe.typeArgs - val formals :+ restpe = targs - val oldClass = originalFunction.symbol.enclClass + // Create a symbol representing a fictional lambda factory method that accepts the captured + // arguments and returns the SAM type. + val msym = { + val meth = currentOwner.newMethod(nme.ANON_FUN_NAME, pos, ARTIFACT) + val capturedParams = meth.newSyntheticValueParams(allCapturedArgRefs.map(_.tpe)) + meth.setInfo(MethodType(capturedParams, fun.tpe)) + } - // find which variables are free in the lambda because those are captures that need to be - // passed into the constructor of the anonymous function class - val captures = FreeVarTraverser.freeVarsOf(originalFunction) + // We then apply this symbol to the captures. + val apply = localTyper.typedPos(pos)(Apply(Ident(msym), allCapturedArgRefs)) - val target = targetMethod(originalFunction) - target.makeNotPrivate(target.owner) - if (!thisReferringMethods.contains(target)) - target setFlag STATIC - - val isStatic = target.hasFlag(STATIC) - - def createBoxingBridgeMethod(functionParamTypes: List[Type], functionResultType: Type): Tree = { - // Note: we bail out of this method and return EmptyTree if we find there is no adaptation required. - // If we need to improve performance, we could check the types first before creating the - // method and parameter symbols. - val methSym = oldClass.newMethod(target.name.append("$adapted").toTermName, target.pos, target.flags | FINAL | ARTIFACT) - var neededAdaptation = false - def boxedType(tpe: Type): Type = { - if (isPrimitiveValueClass(tpe.typeSymbol)) {neededAdaptation = true; ObjectTpe} - else if (enteringErasure(tpe.typeSymbol.isDerivedValueClass)) {neededAdaptation = true; ObjectTpe} - else tpe - } - val targetParams: List[Symbol] = target.paramss.head - val numCaptures = targetParams.length - functionParamTypes.length - val (targetCaptureParams, targetFunctionParams) = targetParams.splitAt(numCaptures) - val bridgeParams: List[Symbol] = - targetCaptureParams.map(param => methSym.newSyntheticValueParam(param.tpe, param.name.toTermName)) ::: - map2(targetFunctionParams, functionParamTypes)((param, tp) => methSym.newSyntheticValueParam(boxedType(tp), param.name.toTermName)) - - val bridgeResultType: Type = { - if (target.info.resultType == UnitTpe && functionResultType != UnitTpe) { - neededAdaptation = true - ObjectTpe - } else - boxedType(functionResultType) - } - val methodType = MethodType(bridgeParams, bridgeResultType) - methSym setInfo methodType - if (!neededAdaptation) - EmptyTree - else { - val bridgeParamTrees = bridgeParams.map(ValDef(_)) - - oldClass.info.decls enter methSym - - val body = localTyper.typedPos(originalFunction.pos) { - val newTarget = Select(gen.mkAttributedThis(oldClass), target) - val args: List[Tree] = mapWithIndex(bridgeParams) { (param, i) => - if (i < numCaptures) { - gen.mkAttributedRef(param) - } else { - val functionParam = functionParamTypes(i - numCaptures) - val targetParam = targetParams(i) - if (enteringErasure(functionParam.typeSymbol.isDerivedValueClass)) { - val casted = cast(gen.mkAttributedRef(param), functionParam) - val unboxed = unbox(casted, ErasedValueType(functionParam.typeSymbol, targetParam.tpe)).modifyType(postErasure.elimErasedValueType) - unboxed - } else adaptToType(gen.mkAttributedRef(param), targetParam.tpe) - } - } - gen.mkMethodCall(newTarget, args) - } - val body1 = if (enteringErasure(functionResultType.typeSymbol.isDerivedValueClass)) - adaptToType(box(body.setType(ErasedValueType(functionResultType.typeSymbol, body.tpe)), "boxing lambda target"), bridgeResultType) - else adaptToType(body, bridgeResultType) - val methDef0 = DefDef(methSym, List(bridgeParamTrees), body1) - postErasure.newTransformer(unit).transform(methDef0).asInstanceOf[DefDef] - } + // TODO: this is a bit gross + val sam = samUserDefined orElse { + if (isSpecialized) functionalInterface.info.decls.find(_.isDeferred).get + else functionalInterface.info.member(nme.apply) } - /** - * Creates the apply method for the anonymous subclass of FunctionN - */ - def createApplyMethod(newClass: Symbol, fun: Function, thisProxy: Symbol): DefDef = { - val methSym = newClass.newMethod(nme.apply, fun.pos, FINAL | SYNTHETIC) - val params = fun.vparams map (_.duplicate) - - val paramSyms = map2(formals, params) { - (tp, vparam) => methSym.newSyntheticValueParam(tp, vparam.name) - } - params zip paramSyms foreach { case (valdef, sym) => valdef.symbol = sym } - params foreach (_.symbol.owner = methSym) - val methodType = MethodType(paramSyms, restpe) - methSym setInfo methodType + // no need for adaptation when the implemented sam is of a specialized built-in function type + val lambdaTarget = if (isSpecialized) target else createBoxingBridgeMethodIfNeeded(fun, target, functionalInterface, sam) + val isSerializable = samUserDefined == NoSymbol || samUserDefined.owner.isNonBottomSubClass(definitions.JavaSerializableClass) + val addScalaSerializableMarker = samUserDefined == NoSymbol - newClass.info.decls enter methSym + // The backend needs to know the target of the lambda and the functional interface in order + // to emit the invokedynamic instruction. We pass this information as tree attachment. + // + // see https://docs.oracle.com/javase/8/docs/api/java/lang/invoke/LambdaMetafactory.html + // instantiatedMethodType is derived from lambdaTarget's signature + // samMethodType is derived from samOf(functionalInterface)'s signature + apply.updateAttachment(LambdaMetaFactoryCapable(lambdaTarget, fun.vparams.length, functionalInterface, sam, isSerializable, addScalaSerializableMarker)) - val Apply(_, oldParams) = fun.body - val qual = if (thisProxy.exists) - Select(gen.mkAttributedThis(newClass), thisProxy) - else - gen.mkAttributedThis(oldClass) // sort of a lie, EmptyTree.<static method> would be more honest, but the backend chokes on that. + apply + } - val body = localTyper typed Apply(Select(qual, target), oldParams) - body.substituteSymbols(fun.vparams map (_.symbol), params map (_.symbol)) - body changeOwner (fun.symbol -> methSym) - val methDef = DefDef(methSym, List(params), body) + private val boxingBridgeMethods = mutable.ArrayBuffer[Tree]() - // Have to repack the type to avoid mismatches when existentials - // appear in the result - see SI-4869. - // TODO probably don't need packedType - methDef.tpt setType localTyper.packedType(body, methSym) - methDef - } + private def reboxValueClass(tp: Type) = tp match { + case ErasedValueType(valueClazz, _) => TypeRef(NoPrefix, valueClazz, Nil) + case _ => tp + } - /** - * Creates the constructor on the newly created class. It will handle - * initialization of members that represent the captured environment - */ - def createConstructor(newClass: Symbol, members: List[ValDef]): DefDef = { - val constrSym = newClass.newConstructor(originalFunction.pos, SYNTHETIC) - - val (paramSymbols, params, assigns) = (members map {member => - val paramSymbol = newClass.newVariable(member.symbol.name.toTermName, newClass.pos, 0) - paramSymbol.setInfo(member.symbol.info) - val paramVal = ValDef(paramSymbol) - val paramIdent = Ident(paramSymbol) - val assign = Assign(Select(gen.mkAttributedThis(newClass), member.symbol), paramIdent) - - (paramSymbol, paramVal, assign) - }).unzip3 - - val constrType = MethodType(paramSymbols, newClass.thisType) - constrSym setInfoAndEnter constrType - - val body = - Block( - List( - Apply(Select(Super(gen.mkAttributedThis(newClass), tpnme.EMPTY) setPos newClass.pos, nme.CONSTRUCTOR) setPos newClass.pos, Nil) setPos newClass.pos - ) ++ assigns, - Literal(Constant(())): Tree - ) setPos newClass.pos - - (localTyper typed DefDef(constrSym, List(params), body) setPos newClass.pos).asInstanceOf[DefDef] - } + // exclude primitives and value classes, which need special boxing + private def isReferenceType(tp: Type) = !tp.isInstanceOf[ErasedValueType] && { + val sym = tp.typeSymbol + !(isPrimitiveValueClass(sym) || sym.isDerivedValueClass) + } - val pkg = oldClass.owner - - // Parent for anonymous class def - val abstractFunctionErasedType = AbstractFunctionClass(formals.length).tpe - - // anonymous subclass of FunctionN with an apply method - def makeAnonymousClass: ClassDef = { - val parents = addSerializable(abstractFunctionErasedType) - val funOwner = originalFunction.symbol.owner - - // TODO harmonize the naming of delambdafy anon-fun classes with those spun up by Uncurry - // - make `anonClass.isAnonymousClass` true. - // - use `newAnonymousClassSymbol` or push the required variations into a similar factory method - // - reinstate the assertion in `Erasure.resolveAnonymousBridgeClash` - val suffix = nme.DELAMBDAFY_LAMBDA_CLASS_NAME + "$" + ( - if (funOwner.isPrimaryConstructor) "" - else "$" + funOwner.name + "$" - ) - val oldClassPart = oldClass.name.decode - // make sure the class name doesn't contain $anon, otherwise isAnonymousClass/Function may be true - val name = unit.freshTypeName(s"$oldClassPart$suffix".replace("$anon", "$nestedInAnon")) - - val lambdaClass = pkg newClassSymbol(name, originalFunction.pos, FINAL | SYNTHETIC) addAnnotation SerialVersionUIDAnnotation - lambdaClass.associatedFile = unit.source.file - // make sure currentRun.compiles(lambdaClass) is true (AddInterfaces does the same for trait impl classes) - currentRun.symSource(lambdaClass) = funOwner.sourceFile - lambdaClass setInfo ClassInfoType(parents, newScope, lambdaClass) - assert(!lambdaClass.isAnonymousClass && !lambdaClass.isAnonymousFunction, "anonymous class name: "+ lambdaClass.name) - assert(lambdaClass.isDelambdafyFunction, "not lambda class name: " + lambdaClass.name) - - val captureProxies2 = new LinkedHashMap[Symbol, TermSymbol] - captures foreach {capture => - val sym = lambdaClass.newVariable(unit.freshTermName(capture.name.toString + "$"), capture.pos, SYNTHETIC) - sym setInfo capture.info - captureProxies2 += ((capture, sym)) - } + // determine which lambda target to use with java's LMF -- create a new one if scala-specific boxing is required + def createBoxingBridgeMethodIfNeeded(fun: Function, target: Symbol, functionalInterface: Symbol, sam: Symbol): Symbol = { + val oldClass = fun.symbol.enclClass + val pos = fun.pos + + // At erasure, there won't be any captured arguments (they are added in constructors) + val functionParamTypes = exitingErasure(target.info.paramTypes) + val functionResultType = exitingErasure(target.info.resultType) + + val samParamTypes = exitingErasure(sam.info.paramTypes) + val samResultType = exitingErasure(sam.info.resultType) + + /** How to satisfy the linking invariants of https://docs.oracle.com/javase/8/docs/api/java/lang/invoke/LambdaMetafactory.html + * + * Given samMethodType: (U1..Un)Ru and function type T1,..., Tn => Rt (the target method created by uncurry) + * + * Do we need a bridge, or can we use the original lambda target for implMethod: (<captured args> A1..An)Ra + * (We can ignore capture here.) + * + * If, for i=1..N: + * Ai =:= Ui || (Ai <:< Ui <:< AnyRef) + * Ru =:= void || (Ra =:= Ru || (Ra <:< AnyRef, Ru <:< AnyRef)) + * + * We can use the target method as-is -- if not, we create a bridging one that uses the types closest + * to the target method that still meet the above requirements. + */ + val resTpOk = ( + samResultType =:= UnitTpe + || functionResultType =:= samResultType + || (isReferenceType(samResultType) && isReferenceType(functionResultType))) // yes, this is what the spec says -- no further correspondence required + if (resTpOk && (samParamTypes corresponds functionParamTypes){ (samParamTp, funParamTp) => + funParamTp =:= samParamTp || (isReferenceType(funParamTp) && isReferenceType(samParamTp) && funParamTp <:< samParamTp) }) target + else { + // We have to construct a new lambda target that bridges to the one created by uncurry. + // The bridge must satisfy the above invariants, while also minimizing adaptation on our end. + // LMF will insert runtime casts according to the spec at the above link. + + // we use the more precise type between samParamTp and funParamTp to minimize boxing in the bridge method + // we are constructing a method whose signature matches the sam's signature (because the original target did not) + // whenever a type in the sam's signature is (erases to) a primitive type, we must pick the sam's version, + // as we don't implement the logic regarding widening that's performed by LMF -- we require =:= for primitives + // + // We use the sam's type for the check whether we're dealing with a reference type, as it could be a generic type, + // which means the function's parameter -- even if it expects a value class -- will need to be + // boxed on the generic call to the sam method. - // the Optional proxy that will hold a reference to the 'this' - // object used by the lambda, if any. NoSymbol if there is no this proxy - val thisProxy = { - if (isStatic) - NoSymbol - else { - val sym = lambdaClass.newVariable(nme.FAKE_LOCAL_THIS, originalFunction.pos, SYNTHETIC) - sym.setInfo(oldClass.tpe) - } + val bridgeParamTypes = map2(samParamTypes, functionParamTypes){ (samParamTp, funParamTp) => + if (isReferenceType(samParamTp) && funParamTp <:< samParamTp) funParamTp + else samParamTp } - val decapturify = new DeCapturifyTransformer(captureProxies2, unit, oldClass, lambdaClass, originalFunction.symbol.pos, thisProxy) - - val decapturedFunction = decapturify.transform(originalFunction).asInstanceOf[Function] + val bridgeResultType = + if (resTpOk && isReferenceType(samResultType) && functionResultType <:< samResultType) functionResultType + else samResultType + + val typeAdapter = new TypeAdapter { def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) } + import typeAdapter.{adaptToType, unboxValueClass} + + val targetParams = target.paramss.head + val numCaptures = targetParams.length - functionParamTypes.length + val (targetCapturedParams, targetFunctionParams) = targetParams.splitAt(numCaptures) + + val methSym = oldClass.newMethod(target.name.append("$adapted").toTermName, target.pos, target.flags | FINAL | ARTIFACT | STATIC) + val bridgeCapturedParams = targetCapturedParams.map(param => methSym.newSyntheticValueParam(param.tpe, param.name.toTermName)) + val bridgeFunctionParams = + map2(targetFunctionParams, bridgeParamTypes)((param, tp) => methSym.newSyntheticValueParam(tp, param.name.toTermName)) + + val bridgeParams = bridgeCapturedParams ::: bridgeFunctionParams + + methSym setInfo MethodType(bridgeParams, bridgeResultType) + oldClass.info.decls enter methSym + + val forwarderCall = localTyper.typedPos(pos) { + val capturedArgRefs = bridgeCapturedParams map gen.mkAttributedRef + val functionArgRefs = + map3(bridgeFunctionParams, functionParamTypes, targetParams.drop(numCaptures)) { (bridgeParam, functionParamTp, targetParam) => + val bridgeParamRef = gen.mkAttributedRef(bridgeParam) + val targetParamTp = targetParam.tpe + + // TODO: can we simplify this to something like `adaptToType(adaptToType(bridgeParamRef, functionParamTp), targetParamTp)`? + val unboxed = + functionParamTp match { + case ErasedValueType(clazz, underlying) => + // when the original function expected an argument of value class type, + // the original target will expect the unboxed underlying value, + // whereas the bridge will receive the boxed value (since the sam's argument type did not match and we had to adapt) + localTyper.typed(unboxValueClass(bridgeParamRef, clazz, underlying), targetParamTp) + case _ => bridgeParamRef + } + + adaptToType(unboxed, targetParamTp) + } - val members = (optionSymbol(thisProxy).toList ++ (captureProxies2 map (_._2))) map {member => - lambdaClass.info.decls enter member - ValDef(member, gen.mkZero(member.tpe)) setPos decapturedFunction.pos + gen.mkMethodCall(Select(gen.mkAttributedThis(oldClass), target), capturedArgRefs ::: functionArgRefs) } - // constructor - val constr = createConstructor(lambdaClass, members) - - // apply method with same arguments and return type as original lambda. - val applyMethodDef = createApplyMethod(lambdaClass, decapturedFunction, thisProxy) - - val bridgeMethod = createBridgeMethod(lambdaClass, originalFunction, applyMethodDef) - - def fulldef(sym: Symbol) = - if (sym == NoSymbol) sym.toString - else s"$sym: ${sym.tpe} in ${sym.owner}" + val bridge = postErasure.newTransformer(unit).transform(DefDef(methSym, List(bridgeParams.map(ValDef(_))), + adaptToType(forwarderCall setType functionResultType, bridgeResultType))).asInstanceOf[DefDef] - bridgeMethod foreach (bm => - // TODO SI-6260 maybe just create the apply method with the signature (Object => Object) in all cases - // rather than the method+bridge pair. - if (bm.symbol.tpe =:= applyMethodDef.symbol.tpe) - erasure.resolveAnonymousBridgeClash(applyMethodDef.symbol, bm.symbol) - ) - - val body = members ++ List(constr, applyMethodDef) ++ bridgeMethod - - // TODO if member fields are private this complains that they're not accessible - localTyper.typedPos(decapturedFunction.pos)(ClassDef(lambdaClass, body)).asInstanceOf[ClassDef] - } - - val allCaptureArgs: List[Tree] = { - val thisArg = if (isStatic) Nil else (gen.mkAttributedThis(oldClass) setPos originalFunction.pos) :: Nil - val captureArgs = captures.iterator.map(capture => gen.mkAttributedRef(capture) setPos originalFunction.pos).toList - thisArg ::: captureArgs - } - - val arity = originalFunction.vparams.length - - // Reconstruct the type of the function entering erasure. - // We do this by taking the type after erasure, and re-boxing `ErasedValueType`. - // - // Unfortunately, the more obvious `enteringErasure(target.info)` doesn't work - // as we would like, value classes in parameter position show up as the unboxed types. - val (functionParamTypes, functionResultType) = exitingErasure { - def boxed(tp: Type) = tp match { - case ErasedValueType(valueClazz, _) => TypeRef(NoPrefix, valueClazz, Nil) - case _ => tp - } - // We don't need to deeply map `boxedValueClassType` over the infos as `ErasedValueType` - // will only appear directly as a parameter type in a method signature, as shown - // https://gist.github.com/retronym/ba81dbd462282c504ff8 - val info = target.info - val boxedParamTypes = info.paramTypes.takeRight(arity).map(boxed) - (boxedParamTypes, boxed(info.resultType)) - } - val functionType = definitions.functionType(functionParamTypes, functionResultType) - - val (functionalInterface, isSpecialized) = java8CompatFunctionalInterface(target, functionType) - if (functionalInterface.exists) { - // Create a symbol representing a fictional lambda factory method that accepts the captured - // arguments and returns a Function. - val msym = currentOwner.newMethod(nme.ANON_FUN_NAME, originalFunction.pos, ARTIFACT) - val argTypes: List[Type] = allCaptureArgs.map(_.tpe) - val params = msym.newSyntheticValueParams(argTypes) - msym.setInfo(MethodType(params, functionType)) - val arity = originalFunction.vparams.length - - val lambdaTarget = - if (isSpecialized) - target - else { - createBoxingBridgeMethod(functionParamTypes, functionResultType) match { - case EmptyTree => - target - case bridge => - boxingBridgeMethods += bridge - bridge.symbol - } - } - - // We then apply this symbol to the captures. - val apply = localTyper.typedPos(originalFunction.pos)(Apply(Ident(msym), allCaptureArgs)).asInstanceOf[Apply] - - // The backend needs to know the target of the lambda and the functional interface in order - // to emit the invokedynamic instruction. We pass this information as tree attachment. - apply.updateAttachment(LambdaMetaFactoryCapable(lambdaTarget, arity, functionalInterface)) - InvokeDynamicLambda(apply) - } else { - val anonymousClassDef = makeAnonymousClass - pkg.info.decls enter anonymousClassDef.symbol - val newStat = Typed(New(anonymousClassDef.symbol, allCaptureArgs: _*), TypeTree(abstractFunctionErasedType)) - val typedNewStat = localTyper.typedPos(originalFunction.pos)(newStat) - DelambdafyAnonClass(anonymousClassDef, typedNewStat) + boxingBridgeMethods += bridge + bridge.symbol } } - /** - * Creates a bridge method if needed. The bridge method forwards from apply(x1: Object, x2: Object...xn: Object): Object to - * apply(x1: T1, x2: T2...xn: Tn): T0 using type adaptation on each input and output. The only time a bridge isn't needed - * is when the original lambda is already erased to type Object, Object, Object... => Object - */ - def createBridgeMethod(newClass:Symbol, originalFunction: Function, applyMethod: DefDef): Option[DefDef] = { - val bridgeMethSym = newClass.newMethod(nme.apply, applyMethod.pos, FINAL | SYNTHETIC | BRIDGE) - val originalParams = applyMethod.vparamss(0) - val bridgeParams = originalParams map { originalParam => - val bridgeSym = bridgeMethSym.newSyntheticValueParam(ObjectTpe, originalParam.name) - ValDef(bridgeSym) - } - val bridgeSyms = bridgeParams map (_.symbol) + private def transformFunction(originalFunction: Function): Tree = { + val target = targetMethod(originalFunction) + assert(target.hasFlag(Flags.STATIC)) + target.setFlag(notPRIVATE) - val methodType = MethodType(bridgeSyms, ObjectTpe) - bridgeMethSym setInfo methodType + val funSym = originalFunction.tpe.typeSymbolDirect + // The functional interface that can be used to adapt the lambda target method `target` to the given function type. + val (functionalInterface, isSpecialized) = + if (!isFunctionSymbol(funSym)) (funSym, false) + else { + val specializedName = + specializeTypes.specializedFunctionName(funSym, + exitingErasure(target.info.paramTypes).map(reboxValueClass) :+ reboxValueClass(exitingErasure(target.info.resultType))).toTypeName + + val isSpecialized = specializedName != funSym.name + val functionalInterface = + if (isSpecialized) { + // Unfortunately we still need to use custom functional interfaces for specialized functions so that the + // unboxed apply method is left abstract for us to implement. + currentRun.runDefinitions.Scala_Java8_CompatPackage.info.decl(specializedName.prepend("J")) + } + else FunctionClass(originalFunction.vparams.length) - def adapt(tree: Tree, expectedTpe: Type): (Boolean, Tree) = { - if (tree.tpe =:= expectedTpe) (false, tree) - else (true, adaptToType(tree, expectedTpe)) - } + (functionalInterface, isSpecialized) + } - def adaptAndPostErase(tree: Tree, pt: Type): (Boolean, Tree) = { - val (needsAdapt, adaptedTree) = adapt(tree, pt) - val trans = postErasure.newTransformer(unit) - val postErasedTree = trans.atOwner(currentOwner)(trans.transform(adaptedTree)) // SI-8017 eliminates ErasedValueTypes - (needsAdapt, postErasedTree) - } + val sam = originalFunction.attachments.get[SAMFunction].map(_.sam).getOrElse(NoSymbol) + mkLambdaMetaFactoryCall(originalFunction, target, functionalInterface, sam, isSpecialized) + } - enteringPhase(currentRun.posterasurePhase) { - // e.g, in: - // class C(val a: Int) extends AnyVal; (x: Int) => new C(x) - // - // This type is: - // (x: Int)ErasedValueType(class C, Int) - val liftedBodyDefTpe: MethodType = { - val liftedBodySymbol = { - val Apply(method, _) = originalFunction.body - method.symbol - } - liftedBodySymbol.info.asInstanceOf[MethodType] + // here's the main entry point of the transform + override def transform(tree: Tree): Tree = tree match { + // the main thing we care about is lambdas + case fun: Function => + super.transform(transformFunction(fun)) + case Template(_, _, _) => + def pretransform(tree: Tree): Tree = tree match { + case dd: DefDef if dd.symbol.isDelambdafyTarget => + if (!dd.symbol.hasFlag(STATIC) && methodReferencesThis(dd.symbol)) { + gen.mkStatic(dd, dd.symbol.name, sym => sym) + } else { + dd.symbol.setFlag(STATIC) + dd + } + case t => t } - val (paramNeedsAdaptation, adaptedParams) = (bridgeSyms zip liftedBodyDefTpe.params map {case (bridgeSym, param) => adapt(Ident(bridgeSym) setType bridgeSym.tpe, param.tpe)}).unzip - // SI-8017 Before, this code used `applyMethod.symbol.info.resultType`. - // But that symbol doesn't have a type history that goes back before `delambdafy`, - // so we just see a plain `Int`, rather than `ErasedValueType(C, Int)`. - // This triggered primitive boxing, rather than value class boxing. - val resTp = liftedBodyDefTpe.finalResultType - val body = Apply(gen.mkAttributedSelect(gen.mkAttributedThis(newClass), applyMethod.symbol), adaptedParams) setType resTp - val (needsReturnAdaptation, adaptedBody) = adaptAndPostErase(body, ObjectTpe) - - val needsBridge = (paramNeedsAdaptation contains true) || needsReturnAdaptation - if (needsBridge) { - val methDef = DefDef(bridgeMethSym, List(bridgeParams), adaptedBody) - newClass.info.decls enter bridgeMethSym - Some((localTyper typed methDef).asInstanceOf[DefDef]) - } else None - } + try { + // during this call boxingBridgeMethods will be populated from the Function case + val Template(parents, self, body) = super.transform(deriveTemplate(tree)(_.mapConserve(pretransform))) + Template(parents, self, body ++ boxingBridgeMethods) + } finally boxingBridgeMethods.clear() + case dd: DefDef if dd.symbol.isLiftedMethod && !dd.symbol.isDelambdafyTarget => + // SI-9390 emit lifted methods that don't require a `this` reference as STATIC + // delambdafy targets are excluded as they are made static by `transformFunction`. + if (!dd.symbol.hasFlag(STATIC) && !methodReferencesThis(dd.symbol)) { + dd.symbol.setFlag(STATIC) + dd.symbol.removeAttachment[mixer.NeedStaticImpl.type] + } + super.transform(tree) + case Apply(fun, outer :: rest) if shouldElideOuterArg(fun.symbol, outer) => + val nullOuter = gen.mkZero(outer.tpe) + treeCopy.Apply(tree, transform(fun), nullOuter :: transformTrees(rest)) + case _ => super.transform(tree) } } // DelambdafyTransformer + private def shouldElideOuterArg(fun: Symbol, outerArg: Tree): Boolean = + fun.isConstructor && treeInfo.isQualifierSafeToElide(outerArg) && fun.hasAttachment[OuterArgCanBeElided.type] + // A traverser that finds symbols used but not defined in the given Tree // TODO freeVarTraverser in LambdaLift does a very similar task. With some // analysis this could probably be unified with it @@ -513,40 +329,45 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre } } - // A transformer that converts specified captured symbols into other symbols - // TODO this transform could look more like ThisSubstituter and TreeSymSubstituter. It's not clear that it needs that level of sophistication since the types - // at this point are always very simple flattened/erased types, but it would probably be more robust if it tried to take more complicated types into account - class DeCapturifyTransformer(captureProxies: Map[Symbol, TermSymbol], unit: CompilationUnit, oldClass: Symbol, newClass:Symbol, pos: Position, thisProxy: Symbol) extends TypingTransformer(unit) { - override def transform(tree: Tree) = tree match { - case tree@This(encl) if tree.symbol == oldClass && thisProxy.exists => - gen mkAttributedSelect (gen mkAttributedThis newClass, thisProxy) - case Ident(name) if (captureProxies contains tree.symbol) => - gen mkAttributedSelect (gen mkAttributedThis newClass, captureProxies(tree.symbol)) - case _ => super.transform(tree) + // finds all methods that reference 'this' + class ThisReferringMethodsTraverser extends Traverser { + // the set of methods that refer to this + private val thisReferringMethods = mutable.Set[Symbol]() + + // the set of lifted lambda body methods that each method refers to + private val liftedMethodReferences = mutable.Map[Symbol, Set[Symbol]]().withDefault(_ => mutable.Set()) + + def methodReferencesThisIn(tree: Tree) = { + traverse(tree) + liftedMethodReferences.keys foreach refersToThis + + thisReferringMethods } - } - /** - * Get the symbol of the target lifted lambda body method from a function. I.e. if - * the function is {args => anonfun(args)} then this method returns anonfun's symbol - */ - private def targetMethod(fun: Function): Symbol = fun match { - case Function(_, Apply(target, _)) => - target.symbol - case _ => - // any other shape of Function is unexpected at this point - abort(s"could not understand function with tree $fun") - } + // recursively find methods that refer to 'this' directly or indirectly via references to other methods + // for each method found add it to the referrers set + private def refersToThis(symbol: Symbol): Boolean = { + val seen = mutable.Set[Symbol]() + def loop(symbol: Symbol): Boolean = { + if (seen(symbol)) false + else { + seen += symbol + (thisReferringMethods contains symbol) || + (liftedMethodReferences(symbol) exists loop) && { + // add it early to memoize + debuglog(s"$symbol indirectly refers to 'this'") + thisReferringMethods += symbol + true + } + } + } + loop(symbol) + } - // finds all methods that reference 'this' - class ThisReferringMethodsTraverser() extends Traverser { private var currentMethod: Symbol = NoSymbol - // the set of methods that refer to this - val thisReferringMethods = mutable.Set[Symbol]() - // the set of lifted lambda body methods that each method refers to - val liftedMethodReferences = mutable.Map[Symbol, Set[Symbol]]().withDefault(_ => mutable.Set()) + override def traverse(tree: Tree) = tree match { - case DefDef(_, _, _, _, _, _) => + case DefDef(_, _, _, _, _, _) if tree.symbol.isDelambdafyTarget || tree.symbol.isLiftedMethod => // we don't expect defs within defs. At this phase trees should be very flat if (currentMethod.exists) devWarning("Found a def within a def at a phase where defs are expected to be flattened out.") currentMethod = tree.symbol @@ -557,37 +378,21 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre // They'll be of the form {(args...) => this.anonfun(args...)} // but we do need to make note of the lifted body method in case it refers to 'this' if (currentMethod.exists) liftedMethodReferences(currentMethod) += targetMethod(fun) + case Apply(sel @ Select(This(_), _), args) if sel.symbol.isLiftedMethod => + if (currentMethod.exists) liftedMethodReferences(currentMethod) += sel.symbol + super.traverseTrees(args) + case Apply(fun, outer :: rest) if shouldElideOuterArg(fun.symbol, outer) => + super.traverse(fun) + super.traverseTrees(rest) case This(_) => if (currentMethod.exists && tree.symbol == currentMethod.enclClass) { debuglog(s"$currentMethod directly refers to 'this'") thisReferringMethods add currentMethod } + case _: ClassDef if !tree.symbol.isTopLevel => + case _: DefDef => case _ => super.traverse(tree) } } - - final case class LambdaMetaFactoryCapable(target: Symbol, arity: Int, functionalInterface: Symbol) - - // The functional interface that can be used to adapt the lambda target method `target` to the - // given function type. Returns `NoSymbol` if the compiler settings are unsuitable. - private def java8CompatFunctionalInterface(target: Symbol, functionType: Type): (Symbol, Boolean) = { - val canUseLambdaMetafactory: Boolean = { - val isTarget18 = settings.target.value.contains("jvm-1.8") - settings.isBCodeActive && isTarget18 - } - - val sym = functionType.typeSymbol - val pack = currentRun.runDefinitions.Scala_Java8_CompatPackage - val name1 = specializeTypes.specializedFunctionName(sym, functionType.typeArgs) - val paramTps :+ restpe = functionType.typeArgs - val arity = paramTps.length - val isSpecialized = name1.toTypeName != sym.name - val functionalInterface = if (!isSpecialized) { - currentRun.runDefinitions.Scala_Java8_CompatPackage_JFunction(arity) - } else { - pack.info.decl(name1.toTypeName.prepend("J")) - } - (if (canUseLambdaMetafactory) functionalInterface else NoSymbol, isSpecialized) - } } diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index 6b987f0089..e327a6658c 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -12,7 +12,7 @@ import symtab._ import Flags._ import scala.reflect.internal.Mode._ -abstract class Erasure extends AddInterfaces +abstract class Erasure extends InfoTransform with scala.reflect.internal.transform.Erasure with typechecker.Analyzer with TypingTransformers @@ -71,7 +71,9 @@ abstract class Erasure extends AddInterfaces } override protected def verifyJavaErasure = settings.Xverify || settings.debug - def needsJavaSig(tp: Type) = !settings.Ynogenericsig && NeedsSigCollector.collect(tp) + def needsJavaSig(tp: Type, throwsArgs: List[Type]) = !settings.Ynogenericsig && { + NeedsSigCollector.collect(tp) || throwsArgs.exists(NeedsSigCollector.collect) + } // only refer to type params that will actually make it into the sig, this excludes: // * higher-order type parameters @@ -187,18 +189,23 @@ abstract class Erasure extends AddInterfaces /* Drop redundant types (ones which are implemented by some other parent) from the immediate parents. * This is important on Android because there is otherwise an interface explosion. + * This is now restricted to Scala defined ancestors: a Java defined ancestor may need to be listed + * as an immediate parent to support an `invokespecial`. */ def minimizeParents(parents: List[Type]): List[Type] = if (parents.isEmpty) parents else { - def isInterfaceOrTrait(sym: Symbol) = sym.isInterface || sym.isTrait + def isRedundantParent(sym: Symbol) = sym.isInterface || sym.isTrait var rest = parents.tail var leaves = collection.mutable.ListBuffer.empty[Type] += parents.head while(rest.nonEmpty) { val candidate = rest.head - val nonLeaf = leaves exists { t => t.typeSymbol isSubClass candidate.typeSymbol } - if(!nonLeaf) { - leaves = leaves filterNot { t => isInterfaceOrTrait(t.typeSymbol) && (candidate.typeSymbol isSubClass t.typeSymbol) } - leaves += candidate + if (candidate.typeSymbol.isJavaDefined && candidate.typeSymbol.isInterface) leaves += candidate + else { + val nonLeaf = leaves exists { t => t.typeSymbol isSubClass candidate.typeSymbol } + if (!nonLeaf) { + leaves = leaves filterNot { t => isRedundantParent(t.typeSymbol) && (candidate.typeSymbol isSubClass t.typeSymbol) } + leaves += candidate + } } rest = rest.tail } @@ -251,7 +258,7 @@ abstract class Erasure extends AddInterfaces // Anything which could conceivably be a module (i.e. isn't known to be // a type parameter or similar) must go through here or the signature is // likely to end up with Foo<T>.Empty where it needs Foo<T>.Empty$. - def fullNameInSig(sym: Symbol) = "L" + enteringIcode(sym.javaBinaryName) + def fullNameInSig(sym: Symbol) = "L" + enteringJVM(sym.javaBinaryNameString) def jsig(tp0: Type, existentiallyBound: List[Symbol] = Nil, toplevel: Boolean = false, primitiveOK: Boolean = true): String = { val tp = tp0.dealias @@ -277,7 +284,7 @@ abstract class Erasure extends AddInterfaces val preRebound = pre.baseType(sym.owner) // #2585 dotCleanup( ( - if (needsJavaSig(preRebound)) { + if (needsJavaSig(preRebound, Nil)) { val s = jsig(preRebound, existentiallyBound) if (s.charAt(0) == 'L') s.substring(0, s.length - 1) + "." + sym.javaSimpleName else fullNameInSig(sym) @@ -352,8 +359,8 @@ abstract class Erasure extends AddInterfaces buf append (if (restpe.typeSymbol == UnitClass || sym0.isConstructor) VOID_TAG.toString else jsig(restpe)) buf.toString - case RefinedType(parent :: _, decls) => - boxedSig(parent) + case RefinedType(parents, decls) => + jsig(intersectionDominator(parents), primitiveOK = primitiveOK) case ClassInfoType(parents, _, _) => superSig(parents) case AnnotatedType(_, atp) => @@ -367,8 +374,9 @@ abstract class Erasure extends AddInterfaces else jsig(etp) } } - if (needsJavaSig(info)) { - try Some(jsig(info, toplevel = true)) + val throwsArgs = sym0.annotations flatMap ThrownException.unapply + if (needsJavaSig(info, throwsArgs)) { + try Some(jsig(info, toplevel = true) + throwsArgs.map("^" + jsig(_, toplevel = true)).mkString("")) catch { case ex: UnknownSig => None } } else None @@ -376,16 +384,53 @@ abstract class Erasure extends AddInterfaces class UnknownSig extends Exception - /** The symbol's erased info. This is the type's erasure, except for the following symbols: - * - * - For $asInstanceOf : [T]T - * - For $isInstanceOf : [T]scala#Boolean - * - For class Array : [T]C where C is the erased classinfo of the Array class. - * - For Array[T].<init> : {scala#Int)Array[T] - * - For a type parameter : A type bounds type consisting of the erasures of its bounds. - */ - override def transformInfo(sym: Symbol, tp: Type): Type = - transformMixinInfo(super.transformInfo(sym, tp)) + // TODO: move to constructors? + object mixinTransformer extends Transformer { + /** Add calls to supermixin constructors + * `super[mix].$init$()` + * to tree, which is assumed to be the body of a constructor of class clazz. + */ + private def addMixinConstructorCalls(tree: Tree, clazz: Symbol): Tree = { + def mixinConstructorCall(mc: Symbol): Tree = atPos(tree.pos) { + Apply(SuperSelect(clazz, mc.primaryConstructor), Nil) + } + val mixinConstructorCalls: List[Tree] = { + for (mc <- clazz.mixinClasses.reverse + if mc.isTrait && mc.primaryConstructor != NoSymbol) + yield mixinConstructorCall(mc) + } + tree match { + + case Block(Nil, expr) => + // AnyVal constructor - have to provide a real body so the + // jvm doesn't throw a VerifyError. But we can't add the + // body until now, because the typer knows that Any has no + // constructor and won't accept a call to super.init. + assert((clazz isSubClass AnyValClass) || clazz.info.parents.isEmpty, clazz) + Block(List(Apply(gen.mkSuperInitCall, Nil)), expr) + + case Block(stats, expr) => + // needs `hasSymbolField` check because `supercall` could be a block (named / default args) + val (presuper, supercall :: rest) = stats span (t => t.hasSymbolWhich(_ hasFlag PRESUPER)) + treeCopy.Block(tree, presuper ::: (supercall :: mixinConstructorCalls ::: rest), expr) + } + } + + override def transform(tree: Tree): Tree = { + val sym = tree.symbol + val tree1 = tree match { + case DefDef(_,_,_,_,_,_) if sym.isClassConstructor && sym.isPrimaryConstructor && sym.owner != ArrayClass => + deriveDefDef(tree)(addMixinConstructorCalls(_, sym.owner)) // (3) + case Template(parents, self, body) => + val parents1 = sym.owner.info.parents map (t => TypeTree(t) setPos tree.pos) + treeCopy.Template(tree, parents1, noSelfType, body) + case _ => + tree + } + super.transform(tree1) + } + } + val deconstMap = new TypeMap { // For some reason classOf[Foo] creates ConstantType(Constant(tpe)) with an actual Type for tpe, @@ -510,11 +555,11 @@ abstract class Erasure extends AddInterfaces if (!bridgeNeeded) return - var newFlags = (member.flags | BRIDGE | ARTIFACT) & ~(ACCESSOR | DEFERRED | LAZY | lateDEFERRED) + var newFlags = (member.flags | BRIDGE | ARTIFACT) & ~(ACCESSOR | DEFERRED | LAZY) // If `member` is a ModuleSymbol, the bridge should not also be a ModuleSymbol. Otherwise we // end up with two module symbols with the same name in the same scope, which is surprising // when implementing later phases. - if (member.isModule) newFlags = (newFlags | METHOD) & ~(MODULE | lateMETHOD | STABLE) + if (member.isModule) newFlags = (newFlags | METHOD) & ~(MODULE | STABLE) val bridge = other.cloneSymbolImpl(root, newFlags) setPos root.pos debuglog("generating bridge from %s (%s): %s to %s: %s".format( @@ -589,8 +634,9 @@ abstract class Erasure extends AddInterfaces } /** The modifier typer which retypes with erased types. */ - class Eraser(_context: Context) extends Typer(_context) with TypeAdapter { - val typer = this.asInstanceOf[analyzer.Typer] + class Eraser(_context: Context) extends Typer(_context) { + val typeAdapter = new TypeAdapter { def typedPos(pos: Position)(tree: Tree): Tree = Eraser.this.typedPos(pos)(tree) } + import typeAdapter._ override protected def stabilize(tree: Tree, pre: Type, mode: Mode, pt: Type): Tree = tree @@ -616,10 +662,8 @@ abstract class Erasure extends AddInterfaces // !!! Make pending/run/t5866b.scala work. The fix might be here and/or in unbox1. if (isPrimitiveValueType(targ.tpe) || isErasedValueType(targ.tpe)) { val noNullCheckNeeded = targ.tpe match { - case ErasedValueType(_, underlying) => - isPrimitiveValueClass(underlying.typeSymbol) - case _ => - true + case ErasedValueType(_, underlying) => isPrimitiveValueType(underlying) + case _ => true } if (noNullCheckNeeded) unbox(qual1, targ.tpe) else { @@ -658,7 +702,7 @@ abstract class Erasure extends AddInterfaces var qual1 = typedQualifier(qual) if ((isPrimitiveValueType(qual1.tpe) && !isPrimitiveValueMember(tree.symbol)) || isErasedValueType(qual1.tpe)) - qual1 = box(qual1, "owner "+tree.symbol.owner) + qual1 = box(qual1) else if (!isPrimitiveValueType(qual1.tpe) && isPrimitiveValueMember(tree.symbol)) qual1 = unbox(qual1, tree.symbol.owner.tpe) @@ -667,13 +711,12 @@ abstract class Erasure extends AddInterfaces if (isPrimitiveValueMember(tree.symbol) && !isPrimitiveValueType(qual1.tpe)) { tree.symbol = NoSymbol selectFrom(qual1) - } else if (isMethodTypeWithEmptyParams(qual1.tpe)) { + } else if (isMethodTypeWithEmptyParams(qual1.tpe)) { // see also adaptToType in TypeAdapter assert(qual1.symbol.isStable, qual1.symbol) - val applied = Apply(qual1, List()) setPos qual1.pos setType qual1.tpe.resultType - adaptMember(selectFrom(applied)) + adaptMember(selectFrom(applyMethodWithEmptyParams(qual1))) } else if (!(qual1.isInstanceOf[Super] || (qual1.tpe.typeSymbol isSubClass tree.symbol.owner))) { assert(tree.symbol.owner != ArrayClass) - selectFrom(cast(qual1, tree.symbol.owner.tpe)) + selectFrom(cast(qual1, tree.symbol.owner.tpe.resultType)) } else { selectFrom(qual1) } @@ -732,6 +775,12 @@ abstract class Erasure extends AddInterfaces if (branch == EmptyTree) branch else adaptToType(branch, tree1.tpe) tree1 match { + case fun: Function => + fun.attachments.get[SAMFunction] match { + case Some(SAMFunction(samTp, _)) => fun setType specialScalaErasure(samTp) + case _ => fun + } + case If(cond, thenp, elsep) => treeCopy.If(tree1, cond, adaptBranch(thenp), adaptBranch(elsep)) case Match(selector, cases) => @@ -1019,24 +1068,20 @@ abstract class Erasure extends AddInterfaces // erasure the ScalaRunTime.hash overload goes from Unit => Int to BoxedUnit => Int. // This must be because some earlier transformation is being skipped on ##, but so // far I don't know what. For null we now define null.## == 0. + def staticsCall(methodName: TermName): Tree = { + val newTree = gen.mkMethodCall(RuntimeStaticsModule, methodName, qual :: Nil) + global.typer.typed(newTree) + } + qual.tpe.typeSymbol match { case UnitClass | NullClass => LIT(0) case IntClass => qual case s @ (ShortClass | ByteClass | CharClass) => numericConversion(qual, s) case BooleanClass => If(qual, LIT(true.##), LIT(false.##)) - case _ => - // Since we are past typer, we need to avoid creating trees carrying - // overloaded types. This logic is custom (and technically incomplete, - // although serviceable) for def hash. What is really needed is for - // the overloading logic presently hidden away in a few different - // places to be properly exposed so we can just call "resolveOverload" - // after typer. Until then: - val alts = ScalaRunTimeModule.info.member(nme.hash_).alternatives - def alt1 = alts find (_.info.paramTypes.head =:= qual.tpe) - def alt2 = ScalaRunTimeModule.info.member(nme.hash_) suchThat (_.info.paramTypes.head.typeSymbol == AnyClass) - val newTree = gen.mkRuntimeCall(nme.hash_, qual :: Nil) setSymbol (alt1 getOrElse alt2) - - global.typer.typed(newTree) + case LongClass => staticsCall(nme.longHash) + case FloatClass => staticsCall(nme.floatHash) + case DoubleClass => staticsCall(nme.doubleHash) + case _ => staticsCall(nme.anyHash) } } else if (isPrimitiveValueClass(qual.tpe.typeSymbol)) { // Rewrite 5.getClass to ScalaRunTime.anyValClass(5) @@ -1052,7 +1097,7 @@ abstract class Erasure extends AddInterfaces // See SI-5568. tree setSymbol Object_getClass } else { - devWarning(s"The symbol '${fn.symbol}' was interecepted but didn't match any cases, that means the intercepted methods set doesn't match the code") + devWarning(s"The symbol '${fn.symbol}' was intercepted but didn't match any cases, that means the intercepted methods set doesn't match the code") tree } } else qual match { @@ -1076,7 +1121,8 @@ abstract class Erasure extends AddInterfaces case TypeApply(fun, args) if (fun.symbol.owner != AnyClass && fun.symbol != Object_asInstanceOf && - fun.symbol != Object_isInstanceOf) => + fun.symbol != Object_isInstanceOf && + fun.symbol != Object_synchronized) => // leave all other type tests/type casts, remove all other type applications preErase(fun) @@ -1115,7 +1161,6 @@ abstract class Erasure extends AddInterfaces } } else tree case Template(parents, self, body) => - assert(!currentOwner.isImplClass) //Console.println("checking no dble defs " + tree)//DEBUG checkNoDoubleDefs(tree.symbol.owner) treeCopy.Template(tree, parents, noSelfType, addBridges(body, currentOwner)) @@ -1125,7 +1170,7 @@ abstract class Erasure extends AddInterfaces case Literal(ct) if ct.tag == ClazzTag && ct.typeValue.typeSymbol != definitions.UnitClass => - val erased = ct.typeValue match { + val erased = ct.typeValue.dealiasWiden match { case tr @ TypeRef(_, clazz, _) if clazz.isDerivedValueClass => scalaErasure.eraseNormalClassRef(tr) case tpe => specialScalaErasure(tpe) } @@ -1154,14 +1199,24 @@ abstract class Erasure extends AddInterfaces else { val tree1 = preErase(tree) tree1 match { + case TypeApply(fun, targs @ List(targ)) if (fun.symbol == Any_asInstanceOf || fun.symbol == Object_synchronized) && targ.tpe == UnitTpe => + // SI-9066 prevent transforming `o.asInstanceOf[Unit]` to `o.asInstanceOf[BoxedUnit]`. + // adaptMember will then replace the call by a reference to BoxedUnit.UNIT. + treeCopy.TypeApply(tree1, transform(fun), targs).clearType() case EmptyTree | TypeTree() => tree1 setType specialScalaErasure(tree1.tpe) case ArrayValue(elemtpt, trees) => treeCopy.ArrayValue( tree1, elemtpt setType specialScalaErasure.applyInArray(elemtpt.tpe), trees map transform).clearType() case DefDef(_, _, _, _, tpt, _) => + // TODO: move this in some post-processing transform in the fields phase? + if (fields.symbolAnnotationsTargetFieldAndGetter(tree.symbol)) + fields.dropFieldAnnotationsFromGetter(tree.symbol) + try super.transform(tree1).clearType() finally tpt setType specialErasure(tree1.symbol)(tree1.symbol.tpe).resultType + case ApplyDynamic(qual, Literal(Constant(bootstrapMethodRef: Symbol)) :: _) => + tree case _ => super.transform(tree1).clearType() } @@ -1192,5 +1247,41 @@ abstract class Erasure extends AddInterfaces bridge.resetFlag(BRIDGE) } + /** Does this symbol compile to the underlying platform's notion of an interface, + * without requiring compiler magic before it can be instantiated? + * + * More specifically, we're interested in whether LambdaMetaFactory can instantiate this type, + * assuming it has a single abstract method. In other words, if we were to mix this + * trait into a class, it should not result in any compiler-generated members having to be + * implemented in ("mixed in to") this class (except for the SAM). + * + * Thus, the type must erase to a java interface, either by virtue of being defined as one, + * or by being a trait that: + * - is static (explicitouter or lambdalift may add disqualifying members) + * - extends only other traits that compile to pure interfaces (except for Any) + * - has no val/var members + * + * TODO: can we speed this up using the INTERFACE flag, or set it correctly by construction? + */ + final def compilesToPureInterface(tpSym: Symbol): Boolean = { + def ok(sym: Symbol) = + sym.isJavaInterface || + sym.isTrait && + // Unless sym.isStatic, even if the constructor is zero-argument now, it may acquire arguments in explicit outer or lambdalift. + // This is an impl restriction to simplify the decision of whether to expand the SAM during uncurry + // (when we don't yet know whether it will receive an outer pointer in explicit outer or whether lambda lift will add proxies for captures). + // When we delay sam expansion until after explicit outer & lambda lift, we could decide there whether + // to expand sam at compile time or use LMF, and this implementation restriction could be lifted. + sym.isStatic && + // HACK: this is to rule out traits with an effectful initializer. + // The constructor only exists if the trait's template has statements. + // Sadly, we can't be more precise without access to the tree that defines the SAM's owner. + !sym.primaryConstructor.exists && + (sym.isInterface || sym.info.decls.forall(mem => mem.isMethod || mem.isType)) // TODO OPT: && {sym setFlag INTERFACE; true}) + + // we still need to check our ancestors even if the INTERFACE flag is set, as it doesn't take inheritance into account + ok(tpSym) && tpSym.ancestors.forall(sym => (sym eq AnyClass) || (sym eq ObjectClass) || ok(sym)) + } + private class TypeRefAttachment(val tpe: TypeRef) } diff --git a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala index 540de2cfe1..8bdbf16e03 100644 --- a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala +++ b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala @@ -8,10 +8,8 @@ package tools.nsc package transform import symtab._ -import Flags.{ CASE => _, _ } -import scala.collection.mutable +import Flags.{CASE => _, _} import scala.collection.mutable.ListBuffer -import scala.tools.nsc.settings.ScalaVersion /** This class ... * @@ -69,8 +67,6 @@ abstract class ExplicitOuter extends InfoTransform result } - private val innerClassConstructorParamName: TermName = newTermName("arg" + nme.OUTER) - class RemoveBindingsTransformer(toRemove: Set[Symbol]) extends Transformer { override def transform(tree: Tree) = tree match { case Bind(_, body) if toRemove(tree.symbol) => super.transform(body) @@ -159,20 +155,18 @@ abstract class ExplicitOuter extends InfoTransform * elides outer pointers. */ def transformInfo(sym: Symbol, tp: Type): Type = tp match { - case MethodType(params, restpe1) => - val restpe = transformInfo(sym, restpe1) - if (sym.owner.isTrait && ((sym hasFlag (ACCESSOR | SUPERACCESSOR)) || sym.isModule)) { // 5 - sym.makeNotPrivate(sym.owner) - } - if (sym.owner.isTrait && sym.isProtected) sym setFlag notPROTECTED // 6 - if (sym.isClassConstructor && isInner(sym.owner)) { // 1 - val p = sym.newValueParameter(innerClassConstructorParamName, sym.pos) - .setInfo(sym.owner.outerClass.thisType) - MethodType(p :: params, restpe) - } else if (restpe ne restpe1) - MethodType(params, restpe) + case MethodType(params, resTp) => + val resTpTransformed = transformInfo(sym, resTp) + + val paramsWithOuter = + if (sym.isClassConstructor && isInner(sym.owner)) // 1 + sym.newValueParameter(nme.OUTER_ARG, sym.pos).setInfo(sym.owner.outerClass.thisType) :: params + else params + + if ((resTpTransformed ne resTp) || (paramsWithOuter ne params)) MethodType(paramsWithOuter, resTpTransformed) else tp - case ClassInfoType(parents, decls, clazz) => + + case ClassInfoType(parents, decls, clazz) if !clazz.isJava => var decls1 = decls if (isInner(clazz) && !clazz.isInterface) { decls1 = decls.cloneScope @@ -201,14 +195,6 @@ abstract class ExplicitOuter extends InfoTransform if (restp eq restp1) tp else PolyType(tparams, restp1) case _ => - // Local fields of traits need to be unconditionally unprivatized. - // Reason: Those fields might need to be unprivatized if referenced by an inner class. - // On the other hand, mixing in the trait into a separately compiled - // class needs to have a common naming scheme, independently of whether - // the field was accessed from an inner class or not. See #2946 - if (sym.owner.isTrait && sym.isLocalToThis && - (sym.getterIn(sym.owner.toInterface) == NoSymbol)) - sym.makeNotPrivate(sym.owner) tp } @@ -238,12 +224,17 @@ abstract class ExplicitOuter extends InfoTransform * Will return `EmptyTree` if there is no outer accessor because of a premature self reference. */ private def outerSelect(base: Tree): Tree = { - val baseSym = base.tpe.typeSymbol.toInterface + val baseSym = base.tpe.typeSymbol val outerAcc = outerAccessor(baseSym) - if (outerAcc == NoSymbol && baseSym.ownersIterator.exists(isUnderConstruction)) { - // e.g neg/t6666.scala - // The caller will report the error with more information. - EmptyTree + if (outerAcc == NoSymbol) { + if (baseSym.ownersIterator.exists(isUnderConstruction)) { + // e.g neg/t6666.scala + // The caller will report the error with more information. + EmptyTree + } else { + globalError(currentOwner.pos, s"Internal error: unable to find the outer accessor symbol of $baseSym") + EmptyTree + } } else { val currentClass = this.currentClass //todo: !!! if this line is removed, we get a build failure that protected$currentClass need an override modifier // outerFld is the $outer field of the current class, if the reference can @@ -251,6 +242,7 @@ abstract class ExplicitOuter extends InfoTransform // otherwise it is NoSymbol val outerFld = if (outerAcc.owner == currentClass && + !outerAcc.owner.isTrait && base.tpe =:= currentClass.thisType && outerAcc.owner.isEffectivelyFinal) outerField(currentClass) suchThat (_.owner == currentClass) @@ -271,8 +263,7 @@ abstract class ExplicitOuter extends InfoTransform */ protected def outerPath(base: Tree, from: Symbol, to: Symbol): Tree = { //Console.println("outerPath from "+from+" to "+to+" at "+base+":"+base.tpe) - //assert(base.tpe.widen.baseType(from.toInterface) != NoType, ""+base.tpe.widen+" "+from.toInterface)//DEBUG - if (from == to || from.isImplClass && from.toInterface == to) base + if (from == to) base else outerPath(outerSelect(base), from.outerClass, to) } @@ -294,61 +285,41 @@ abstract class ExplicitOuter extends InfoTransform } } - /** <p> - * The phase performs the following transformations on terms: - * </p> - * <ol> - * <li> <!-- 1 --> - * <p> - * An class which is not an interface and is not static gets an outer - * accessor (@see outerDefs). - * </p> - * <p> - * 1a. A class which is not a trait gets an outer field. - * </p> - * </li> - * <li> <!-- 4 --> - * A constructor of a non-trait inner class gets an outer parameter. - * </li> - * <li> <!-- 5 --> - * A reference C.this where C refers to an - * outer class is replaced by a selection - * this.$outer$$C1 ... .$outer$$Cn (@see outerPath) - * </li> - * <li> - * </li> - * <li> <!-- 7 --> - * A call to a constructor Q.<init>(args) or Q.$init$(args) where Q != this and - * the constructor belongs to a non-static class is augmented by an outer argument. - * E.g. Q.<init>(OUTER, args) where OUTER - * is the qualifier corresponding to the singleton type Q. - * </li> - * <li> - * A call to a constructor this.<init>(args) in a - * secondary constructor is augmented to this.<init>(OUTER, args) - * where OUTER is the last parameter of the secondary constructor. - * </li> - * <li> <!-- 9 --> - * Remove private modifier from class members M - * that are accessed from an inner class. - * </li> - * <li> <!-- 10 --> - * Remove protected modifier from class members M - * that are accessed without a super qualifier accessed from an inner - * class or trait. - * </li> - * <li> <!-- 11 --> - * Remove private and protected modifiers - * from type symbols - * </li> - * <li> <!-- 12 --> - * Remove private modifiers from members of traits - * </li> - * </ol> - * <p> - * Note: The whole transform is run in phase explicitOuter.next. - * </p> - */ + /** The phase performs the following transformations (more or less...): + * + * (1) An class which is not an interface and is not static gets an outer accessor (@see outerDefs). + * (1a) A class which is not a trait gets an outer field. + * + * (4) A constructor of a non-trait inner class gets an outer parameter. + * + * (5) A reference C.this where C refers to an outer class is replaced by a selection + * `this.$outer$$C1 ... .$outer$$Cn` (@see outerPath) + * + * (7) A call to a constructor Q.(args) or Q.$init$(args) where Q != this and + * the constructor belongs to a non-static class is augmented by an outer argument. + * E.g. Q.(OUTER, args) where OUTER + * is the qualifier corresponding to the singleton type Q. + * + * (8) A call to a constructor this.(args) in a + * secondary constructor is augmented to this.(OUTER, args) + * where OUTER is the last parameter of the secondary constructor. + * + * (9) Remove private modifier from class members M that are accessed from an inner class. + * + * (10) Remove protected modifier from class members M that are accessed + * without a super qualifier accessed from an inner class or trait. + * + * (11) Remove private and protected modifiers from type symbols + * + * Note: The whole transform is run in phase explicitOuter.next. + * + * TODO: Make this doc reflect what's actually going on. + * Some of the deviations are motivated by separate compilation + * (name mangling based on usage is inherently unstable). + * Now that traits are compiled 1:1 to interfaces, they can have private members, + * so there's also less need to make trait members non-private + * (they still may need to be implemented in subclasses, though we could make those protected...). + */ class ExplicitOuterTransformer(unit: CompilationUnit) extends OuterPathTransformer(unit) { transformer => @@ -397,7 +368,7 @@ abstract class ExplicitOuter extends InfoTransform case Template(parents, self, decls) => val newDefs = new ListBuffer[Tree] atOwner(tree, currentOwner) { - if (!currentClass.isInterface || (currentClass hasFlag lateINTERFACE)) { + if (!currentClass.isInterface) { if (isInner(currentClass)) { if (hasOuterField(currentClass)) newDefs += outerFieldDef // (1a) @@ -446,8 +417,10 @@ abstract class ExplicitOuter extends InfoTransform // // See SI-6552 for an example of why `sym.owner.enclMethod hasAnnotation ScalaInlineClass` // is not suitable; if we make a method-local class non-private, it mangles outer pointer names. - if (currentClass != sym.owner || - (closestEnclMethod(currentOwner) hasAnnotation ScalaInlineClass)) + def enclMethodIsInline = closestEnclMethod(currentOwner) hasAnnotation ScalaInlineClass + // SI-8710 The extension method condition reflects our knowledge that a call to `new Meter(12).privateMethod` + // with later be rewritten (in erasure) to `Meter.privateMethod$extension(12)`. + if ((currentClass != sym.owner || enclMethodIsInline) && !sym.isMethodWithExtension) sym.makeNotPrivate(sym.owner) val qsym = qual.tpe.widen.typeSymbol @@ -474,14 +447,15 @@ abstract class ExplicitOuter extends InfoTransform // base.<outer>.eq(o) --> base.$outer().eq(o) if there's an accessor, else the whole tree becomes TRUE // TODO remove the synthetic `<outer>` method from outerFor?? case Apply(eqsel@Select(eqapp@Apply(sel@Select(base, nme.OUTER_SYNTH), Nil), eq), args) => - val outerFor = sel.symbol.owner.toInterface // TODO: toInterface necessary? + val outerFor = sel.symbol.owner val acc = outerAccessor(outerFor) if (acc == NoSymbol || // since we can't fix SI-4440 properly (we must drop the outer accessors of final classes when there's no immediate reference to them in sight) // at least don't crash... this duplicates maybeOmittable from constructors (acc.owner.isEffectivelyFinal && !acc.isOverridingSymbol)) { - currentRun.reporting.uncheckedWarning(tree.pos, "The outer reference in this type test cannot be checked at run time.") + if (!base.tpe.hasAnnotation(UncheckedClass)) + currentRun.reporting.uncheckedWarning(tree.pos, "The outer reference in this type test cannot be checked at run time.") transform(TRUE) // urgh... drop condition if there's no accessor (or if it may disappear after constructors) } else { // println("(base, acc)= "+(base, acc)) diff --git a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala index 116047a2ad..f2237a0716 100644 --- a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala +++ b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala @@ -7,7 +7,7 @@ package transform import symtab._ import Flags._ -import scala.collection.{ mutable, immutable } +import scala.collection.mutable /** * Perform Step 1 in the inline classes SIP: Creates extension methods for all @@ -192,8 +192,7 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { extensionDefs(currentOwner.companionModule) = new mutable.ListBuffer[Tree] currentOwner.primaryConstructor.makeNotPrivate(NoSymbol) // SI-7859 make param accessors accessible so the erasure can generate unbox operations. - val paramAccessors = currentOwner.info.decls.filter(sym => sym.isParamAccessor && sym.isMethod) - paramAccessors.foreach(_.makeNotPrivate(currentOwner)) + currentOwner.info.decls.foreach(sym => if (sym.isParamAccessor && sym.isMethod) sym.makeNotPrivate(currentOwner)) super.transform(tree) } else if (currentOwner.isStaticOwner) { super.transform(tree) @@ -208,7 +207,7 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { def makeExtensionMethodSymbol = { val extensionName = extensionNames(origMeth).head.toTermName val extensionMeth = ( - companion.moduleClass.newMethod(extensionName, tree.pos.focus, origMeth.flags & ~OVERRIDE & ~PROTECTED & ~LOCAL | FINAL) + companion.moduleClass.newMethod(extensionName, tree.pos.focus, origMeth.flags & ~OVERRIDE & ~PROTECTED & ~PRIVATE & ~LOCAL | FINAL) setAnnotations origMeth.annotations ) origMeth.removeAnnotation(TailrecClass) // it's on the extension method, now. @@ -244,7 +243,10 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { // These three lines are assembling Foo.bar$extension[T1, T2, ...]($this) // which leaves the actual argument application for extensionCall. - val sel = Select(gen.mkAttributedRef(companion), extensionMeth) + // SI-9542 We form the selection here from the thisType of the companion's owner. This is motivated + // by the test case, and is a valid way to construct the reference because we know that this + // method is also enclosed by that owner. + val sel = Select(gen.mkAttributedRef(companion.owner.thisType, companion), extensionMeth) val targs = origTpeParams map (_.tpeHK) val callPrefix = gen.mkMethodCall(sel, targs, This(origThis) :: Nil) diff --git a/src/compiler/scala/tools/nsc/transform/Fields.scala b/src/compiler/scala/tools/nsc/transform/Fields.scala new file mode 100644 index 0000000000..b2bf9fad3f --- /dev/null +++ b/src/compiler/scala/tools/nsc/transform/Fields.scala @@ -0,0 +1,787 @@ +/* NSC -- new Scala compiler + * Copyright 2005-2013 LAMP/EPFL + * @author + */ + +package scala.tools.nsc +package transform + +import scala.annotation.tailrec +import symtab.Flags._ + + +/** Synthesize accessors, fields (and bitmaps) for (lazy) vals and modules. + * + * During Namers, a `ValDef` that is `lazy`, deferred and/or defined in a trait carries its getter's symbol. + * The underlying field symbol does not exist until this phase. + * + * For `val`s defined in classes, we still emit a field immediately. + * TODO: uniformly assign getter symbol to all `ValDef`s, stop using `accessed`. + * + * This phase synthesizes accessors, fields and bitmaps (for lazy or init-checked vals under -Xcheckinit) + * in the first (closest in the subclassing lattice) subclass (not a trait) of a trait. + * + * For lazy vals and modules, we emit accessors that using double-checked locking (DCL) to balance thread safety + * and performance. For both lazy vals and modules, the a compute method contains the DCL's slow path. + * + * Local lazy vals do not receive bitmaps, but use a Lazy*Holder that has the volatile init bit and the computed value. + * See `mkLazyLocalDef`. + * + * Constructors will move the rhs to an assignment in the template body. + * Those statements then move to the template into the constructor, + * which means it will initialize the fields defined in this template (and execute the corresponding side effects). + * We need to maintain the connection between getter and rhs until after specialization so that it can duplicate vals. + * + * A ModuleDef is desugared to a ClassDef, an accessor (which reuses the module's term symbol) + * and a module var (unless the module is static and does not implement a member of a supertype, or we're in a trait). + * + * For subclasses of traits that define modules, a module var is mixed in, as well as the required module accessors. + * + * Phase ordering: + * - Runs after uncurry to deal with classes that implement SAM traits with ValDefs. + * - Runs before erasure (to get bridges), and thus before lambdalift/flatten, so that nested functions/definitions must be considered. + * - Lambdalift introduces new paramaccessors for captured vals, but runs too late in the pipeline, so + * mixins still synthesizes implementations for these accessors when a local trait that captures is subclassed. + * + * + * In the future, would like to get closer to dotty, which lifts a val's RHS (a similar thing is done for template-level statements) + * to a method `$_initialize_$1$x` instead of a block, which is used in the constructor to initialize the val. + * This makes for a nice unification of strict and lazy vals, in that the RHS is lifted to a method for both, + * with the corresponding compute method called at the appropriate time.) + * + * This only reduces the required number of methods per field declaration in traits, + * if we encode the name (and place in initialisation order) of the field + * in the name of its initializing method, to allow separate compilation. + * (The name mangling must include ordering, and thus complicate incremental compilation: + * ideally, we'd avoid renumbering unchanged methods, but that would result in + * different bytecode between clean recompiles and incremental ones). + * + * In the even longer term (Scala 3?), I agree with @DarkDimius that it would make sense + * to hide the difference between strict and lazy vals. All vals are lazy, + * but the memoization overhead is removed when we statically know they are forced during initialization. + * We could still expose the low-level field semantics through `private[this] val`s. + * + * In any case, the current behavior of overriding vals is pretty surprising. + * An overridden val's side-effect is still performed. + * The only change due to overriding is that its value is never written to the field + * (the overridden val's value is, of course, stored in the field in addition to its side-effect being performed). + * + * TODO: Java 9 support for vals defined in traits. They are currently emitted as final, + * but the write (putfield) to the val does not occur syntactically within the <init> method + * (it's done by the trait setter, which is called from the trait's mixin constructor, + * which is called from the subclass's constructor...) + */ +abstract class Fields extends InfoTransform with ast.TreeDSL with TypingTransformers with AccessorSynthesis { + import global._ + import definitions._ + + /** the following two members override abstract members in Transform */ + val phaseName: String = "fields" + + protected def newTransformer(unit: CompilationUnit): Transformer = new FieldsTransformer(unit) + override def transformInfo(sym: Symbol, tp: Type): Type = + if (sym.isJavaDefined || sym.isPackageClass || !sym.isClass) tp + else synthFieldsAndAccessors(tp) + + // TODO: drop PRESUPER support when we implement trait parameters in 2.13 + private def excludedAccessorOrFieldByFlags(statSym: Symbol): Boolean = statSym hasFlag PRESUPER + + // used for internal communication between info and tree transform of this phase -- not pickled, not in initialflags + // TODO: reuse MIXEDIN for NEEDS_TREES? + override def phaseNewFlags: Long = NEEDS_TREES | OVERRIDDEN_TRAIT_SETTER + + // informs the tree traversal of the shape of the tree to emit + // (it's an *overridden* trait setter) + private final val OVERRIDDEN_TRAIT_SETTER = TRANS_FLAG + + final val TRAIT_SETTER_FLAGS = NEEDS_TREES | DEFERRED | ProtectedLocal + + private def accessorImplementedInSubclass(accessor: Symbol) = + (accessor hasFlag SYNTHESIZE_IMPL_IN_SUBCLASS) && (accessor hasFlag (ACCESSOR | MODULE)) + + @inline final def notDeferredOrSynthImpl(sym: Symbol): Boolean = !(sym hasFlag DEFERRED) || (sym hasFlag SYNTHESIZE_IMPL_IN_SUBCLASS) + + private def synthesizeImplInSubclasses(accessor: Symbol): Unit = + accessor setFlag SYNTHESIZE_IMPL_IN_SUBCLASS + + private def setClonedTraitSetterFlags(clazz: Symbol, correspondingGetter: Symbol, cloneInSubclass: Symbol): Unit = { + val overridden = isOverriddenAccessor(correspondingGetter, clazz) + if (overridden) cloneInSubclass setFlag OVERRIDDEN_TRAIT_SETTER + else if (correspondingGetter.isEffectivelyFinal) cloneInSubclass setFlag FINAL + } + + // TODO: add MIXEDIN (see e.g., `accessed` on `Symbol`) + private def setMixedinAccessorFlags(orig: Symbol, cloneInSubclass: Symbol): Unit = + cloneInSubclass setFlag OVERRIDE | NEEDS_TREES resetFlag DEFERRED | SYNTHESIZE_IMPL_IN_SUBCLASS + + private def setFieldFlags(accessor: Symbol, fieldInSubclass: TermSymbol): Unit = + fieldInSubclass setFlag (NEEDS_TREES | + PrivateLocal + | (accessor getFlag MUTABLE | LAZY) + | (if (accessor hasFlag STABLE) 0 else MUTABLE) + ) + + + def checkAndClearOverriddenTraitSetter(setter: Symbol) = checkAndClear(OVERRIDDEN_TRAIT_SETTER)(setter) + def checkAndClearNeedsTrees(setter: Symbol) = checkAndClear(NEEDS_TREES)(setter) + def checkAndClear(flag: Long)(sym: Symbol) = + sym.hasFlag(flag) match { + case overridden => + sym resetFlag flag + overridden + } + + + private def isOverriddenAccessor(member: Symbol, site: Symbol): Boolean = { + val pre = site.thisType + @tailrec def loop(bcs: List[Symbol]): Boolean = { + // println(s"checking ${bcs.head} for member overriding $member (of ${member.owner})") + bcs.nonEmpty && bcs.head != member.owner && (matchingAccessor(pre, member, bcs.head) != NoSymbol || loop(bcs.tail)) + } + + member.exists && loop(site.info.baseClasses) + } + + + def matchingAccessor(pre: Type, member: Symbol, clazz: Symbol) = { + val res = member.matchingSymbol(clazz, pre) filter (sym => (sym hasFlag ACCESSOR) && notDeferredOrSynthImpl(sym)) + // if (res != NoSymbol) println(s"matching accessor for $member in $clazz = $res (under $pre)") + // else println(s"no matching accessor for $member in $clazz (under $pre) among ${clazz.info.decls}") + res + } + + + class FieldMemoization(accessorOrField: Symbol, site: Symbol) { + val tp = fieldTypeOfAccessorIn(accessorOrField, site.thisType) + // We can only omit strict vals of ConstantType. Lazy vals do not receive constant types (anymore). + // (See note at widenIfNecessary -- for example, the REPL breaks when we omit constant lazy vals) + // Note that a strict unit-typed val does receive a field, because we cannot omit the write to the field + // (well, we could emit it for non-@volatile ones, if I understand the memory model correctly, + // but that seems pretty edge-casey) + val constantTyped = tp.isInstanceOf[ConstantType] + } + + private def fieldTypeForGetterIn(getter: Symbol, pre: Type): Type = getter.info.finalResultType.asSeenFrom(pre, getter.owner) + private def fieldTypeForSetterIn(setter: Symbol, pre: Type): Type = setter.info.paramTypes.head.asSeenFrom(pre, setter.owner) + + // TODO: is there a more elegant way? + def fieldTypeOfAccessorIn(accessor: Symbol, pre: Type) = + if (accessor.isSetter) fieldTypeForSetterIn(accessor, pre) + else fieldTypeForGetterIn(accessor, pre) + + + // Constant/unit typed vals are not memoized (their value is so cheap it doesn't make sense to store it in a field) + // for a unit-typed getter, we perform the effect at the appropriate time (constructor for eager ones, lzyCompute for lazy), + // and have the getter just return Unit (who does that!?) + // NOTE: this only considers type, filter on flags first! + def fieldMemoizationIn(accessorOrField: Symbol, site: Symbol) = new FieldMemoization(accessorOrField, site) + + // drop field-targeting annotations from getters (done during erasure because we first need to create the field symbol) + // (in traits, getters must also hold annotations that target the underlying field, + // because the latter won't be created until the trait is mixed into a class) + // TODO do bean getters need special treatment to suppress field-targeting annotations in traits? + def dropFieldAnnotationsFromGetter(sym: Symbol) = + sym setAnnotations (sym.annotations filter AnnotationInfo.mkFilter(GetterTargetClass, defaultRetention = false)) + + def symbolAnnotationsTargetFieldAndGetter(sym: Symbol): Boolean = sym.isGetter && (sym.isLazy || sym.owner.isTrait) + + // A trait val/var or a lazy val does not receive an underlying field symbol until this phase. + // Since annotations need a carrier symbol from the beginning, both field- and getter-targeting annotations + // are kept on the getter symbol for these until they are dropped by dropFieldAnnotationsFromGetter + def getterTreeAnnotationsTargetFieldAndGetter(owner: Symbol, mods: Modifiers) = mods.isLazy || owner.isTrait + + // Propagate field-targeting annotations from getter to field. + // By the way, we must keep them around long enough to see them here (now that we have created the field), + // which is why dropFieldAnnotationsFromGetter is not called until erasure. + private def propagateFieldAnnotations(getter: Symbol, field: TermSymbol): Unit = + field setAnnotations (getter.annotations filter AnnotationInfo.mkFilter(FieldTargetClass, defaultRetention = true)) + + + // can't use the referenced field since it already tracks the module's moduleClass + private[this] val moduleOrLazyVarOf = perRunCaches.newMap[Symbol, Symbol] + + // TODO: can we drop FINAL? In any case, since these variables are MUTABLE, they cannot and will + // not be emitted as ACC_FINAL. They are FINAL in the Scala sense, though: cannot be overridden. + private final val ModuleOrLazyFieldFlags = FINAL | PrivateLocal | SYNTHETIC | NEEDS_TREES + + private def moduleInit(module: Symbol, moduleVar: Symbol) = { +// println(s"moduleInit for $module in ${module.ownerChain} --> ${moduleVarOf.get(module)}") + def moduleVarRef = gen.mkAttributedRef(moduleVar) + + // for local modules, we synchronize on the owner of the method that owns the module + val monitorHolder = This(moduleVar.owner.enclClass) + def needsInit = Apply(Select(moduleVarRef, Object_eq), List(CODE.NULL)) + val init = Assign(moduleVarRef, gen.newModule(module, moduleVar.info)) + + /** double-checked locking following https://shipilev.net/blog/2014/safe-public-construction/#_safe_publication + * + * public class SafeDCLFactory { + * private volatile Singleton instance; + * + * public Singleton get() { + * if (instance == null) { // check 1 + * synchronized(this) { + * if (instance == null) { // check 2 + * instance = new Singleton(); + * } + * } + * } + * return instance; + * } + * } + * + * TODO: optimize using local variable? + */ + val computeName = nme.newLazyValSlowComputeName(module.name) + val computeMethod = DefDef(NoMods, computeName, Nil, ListOfNil, TypeTree(UnitTpe), gen.mkSynchronized(monitorHolder)(If(needsInit, init, EmptyTree))) + Block(computeMethod :: If(needsInit, Apply(Ident(computeName), Nil), EmptyTree) :: Nil, + gen.mkCast(moduleVarRef, module.info.resultType)) + } + + // NoSymbol for lazy accessor sym with unit result type + def lazyVarOf(sym: Symbol) = moduleOrLazyVarOf.getOrElse(sym, NoSymbol) + + private def newLazyVarMember(clazz: Symbol, member: Symbol, tp: Type): TermSymbol = { + val flags = LAZY | (member.flags & FieldFlags) | ModuleOrLazyFieldFlags + val name = member.name.toTermName.append(reflect.NameTransformer.LOCAL_SUFFIX_STRING) + + // Set the MUTABLE flag because the field cannot be ACC_FINAL since we write to it outside of a constructor. + val sym = clazz.newVariable(name, member.pos.focus, flags) setInfo tp + + moduleOrLazyVarOf(member) = sym + sym + } + + + private object synthFieldsAndAccessors extends TypeMap { + private def newTraitSetter(getter: Symbol, clazz: Symbol) = { + // Add setter for an immutable, memoizing getter + // (can't emit during namers because we don't yet know whether it's going to be memoized or not) + val setterFlags = (getter.flags & ~(STABLE | PrivateLocal | OVERRIDE | IMPLICIT | FINAL)) | MUTABLE | ACCESSOR | TRAIT_SETTER_FLAGS + val setterName = nme.expandedSetterName(getter.name.setterName, clazz) + val setter = clazz.newMethod(setterName, getter.pos.focus, setterFlags) + val fieldTp = fieldTypeForGetterIn(getter, clazz.thisType) + // println(s"newTraitSetter in $clazz for $getter = $setterName : $fieldTp") + + getter.asTerm.referenced = setter + + setter setInfo MethodType(List(setter.newSyntheticValueParam(fieldTp)), UnitTpe) + setter + } + + private def newModuleAccessor(module: Symbol, site: Symbol, moduleVar: Symbol) = { + val accessor = site.newMethod(module.name.toTermName, site.pos, STABLE | MODULE | NEEDS_TREES) + + moduleOrLazyVarOf(accessor) = moduleVar + + // we're in the same prefix as module, so no need for site.thisType.memberType(module) + accessor setInfo MethodType(Nil, moduleVar.info) + accessor.setModuleClass(module.moduleClass) + + if (module.isPrivate) accessor.expandName(module.owner) + + accessor + } + + // needed for the following scenario (T could be trait or class) + // trait T { def f: Object }; object O extends T { object f }. Need to generate method f in O. + // marking it as an ACCESSOR so that it will get to `getterBody` when synthesizing trees below + // it should not be considered a MODULE + def newMatchingModuleAccessor(clazz: Symbol, module: Symbol): MethodSymbol = { + val acc = clazz.newMethod(module.name.toTermName, module.pos, (module.flags & ~MODULE) | STABLE | NEEDS_TREES | ACCESSOR) + acc.referenced = module + acc setInfo MethodType(Nil, module.moduleClass.tpe) + } + + + private def newSuperLazy(lazyCallingSuper: Symbol, site: Type, lazyVar: Symbol) = { + lazyCallingSuper.asTerm.referenced = lazyVar + + val tp = site.memberInfo(lazyCallingSuper) + + lazyVar setInfo tp.resultType + lazyCallingSuper setInfo tp + } + + private def classNeedsInfoTransform(cls: Symbol): Boolean = { + !(cls.isPackageClass || cls.isJavaDefined) && (currentRun.compiles(cls) || refChecks.isSeparatelyCompiledScalaSuperclass(cls)) + } + + def apply(tp0: Type): Type = tp0 match { + // TODO: make less destructive (name changes, decl additions, flag setting -- + // none of this is actually undone when travelling back in time using atPhase) + case tp@ClassInfoType(parents, decls, clazz) if clazz.isTrait => + // setters for trait vars or module accessor + val newDecls = collection.mutable.ListBuffer[Symbol]() + val origDecls = decls.toList + + // strict, memoized accessors will receive an implementation in first real class to extend this trait + origDecls.foreach { member => + if (member hasFlag ACCESSOR) { + val fieldMemoization = fieldMemoizationIn(member, clazz) + // check flags before calling makeNotPrivate + val accessorUnderConsideration = !(member hasFlag DEFERRED) + + // destructively mangle accessor's name (which may cause rehashing of decls), also sets flags + // this accessor has to be implemented in a subclass -- can't be private + if ((member hasFlag PRIVATE) && !fieldMemoization.constantTyped) member makeNotPrivate clazz + // Since we need to refer to `member` using a super call in a subclass, we must ensure that access is allowed. + // If `member` has an access boundary, make sure the `PROTECTED` flag is set, + // to widen from `private[foo]` to `protected[foo]` + // (note that `member.hasAccessBoundary` implies `!member.hasFlag(PRIVATE)`, so we don't have to `resetFlag PRIVATE`) + else if (member.isLazy && member.hasAccessBoundary) member setFlag PROTECTED + + // This must remain in synch with publicizeTraitMethod in Mixins, so that the + // synthesized member in a subclass and the trait member remain in synch regarding access. + // Otherwise, the member will not be seen as overriding the trait member, and `addForwarders`'s call to + // `membersBasedOnFlags` would see the deferred member in the trait, instead of the concrete (desired) one in the class + // not doing: if (member hasFlag PROTECTED) member setFlag notPROTECTED + + // must not reset LOCAL, as we must maintain protected[this]ness to allow that variance hole + // (not sure why this only problem only arose when we started setting the notPROTECTED flag) + + // derive trait setter after calling makeNotPrivate (so that names are mangled consistently) + if (accessorUnderConsideration && !fieldMemoization.constantTyped) { + synthesizeImplInSubclasses(member) + + if ((member hasFlag STABLE) && !(member hasFlag LAZY)) + newDecls += newTraitSetter(member, clazz) + } + } else if (member hasFlag MODULE) { + nonStaticModuleToMethod(member) + + member setFlag NEEDS_TREES + synthesizeImplInSubclasses(member) + } + } + + if (newDecls nonEmpty) { + val allDecls = newScope + origDecls foreach allDecls.enter + newDecls foreach allDecls.enter + ClassInfoType(parents, allDecls, clazz) + } else tp + + + case tp@ClassInfoType(parents, oldDecls, clazz) if !classNeedsInfoTransform(clazz) => tp + + // mix in fields & accessors for all mixed in traits + case tp@ClassInfoType(parents, oldDecls, clazz) => + + val site = clazz.thisType + + // setter conflicts cannot arise independently from a getter conflict, since a setter without a getter does not a val definition make + def getterConflictsExistingVal(getter: Symbol): Boolean = + getter.isGetter && { + val existingGetter = oldDecls.lookup(getter.name) + (existingGetter ne NoSymbol) && + ((site memberInfo existingGetter) matches (site memberInfo getter)) + } + + def newModuleVarMember(module: Symbol): TermSymbol = { + val moduleVar = + (clazz.newVariable(nme.moduleVarName(module.name.toTermName), module.pos.focus, MODULEVAR | ModuleOrLazyFieldFlags) + setInfo site.memberType(module).resultType + addAnnotation VolatileAttr) + + moduleOrLazyVarOf(module) = moduleVar + + moduleVar + } + + def newLazyVarMember(member: Symbol): TermSymbol = + Fields.this.newLazyVarMember(clazz, member, site.memberType(member).resultType) + + // a module does not need treatment here if it's static, unless it has a matching member in a superclass + // a non-static method needs a module var + val modulesAndLazyValsNeedingExpansion = + oldDecls.toList.filter(m => (m.isModule && (!m.isStatic || m.isOverridingSymbol)) || m.isLazy) + + val accessorSymbolSynth = checkedAccessorSymbolSynth(tp.typeSymbol) + + // expand module def in class/object (if they need it -- see modulesNeedingExpansion above) + val expandedModulesAndLazyVals = + modulesAndLazyValsNeedingExpansion flatMap { member => + if (member.isLazy) { + val lazyVar = newLazyVarMember(member) + propagateFieldAnnotations(member, lazyVar) + List(lazyVar, accessorSymbolSynth.newSlowPathSymbol(member)) + } + // expanding module def (top-level or nested in static module) + else List(if (member.isStatic) { // implies m.isOverridingSymbol as per above filter + // Need a module accessor, to implement/override a matching member in a superclass. + // Never a need for a module var if the module is static. + newMatchingModuleAccessor(clazz, member) + } else { + nonStaticModuleToMethod(member) + // must reuse symbol instead of creating an accessor + member setFlag NEEDS_TREES + newModuleVarMember(member) + }) + } + +// println(s"expanded modules for $clazz: $expandedModules") + + // afterOwnPhase, so traits receive trait setters for vals (needs to be at finest grain to avoid looping) + val synthInSubclass = + clazz.mixinClasses.flatMap(mixin => afterOwnPhase{mixin.info}.decls.toList.filter(accessorImplementedInSubclass)) + + // mixin field accessors -- + // invariant: (accessorsMaybeNeedingImpl, mixedInAccessorAndFields).zipped.forall(case (acc, clone :: _) => `clone` is clone of `acc` case _ => true) + val mixedInAccessorAndFields = synthInSubclass.map{ member => + def cloneAccessor() = { + val clonedAccessor = (member cloneSymbol clazz) setPos clazz.pos + setMixedinAccessorFlags(member, clonedAccessor) + + // note: check original member when deciding how to triage annotations, then act on the cloned accessor + if (symbolAnnotationsTargetFieldAndGetter(member)) // this simplifies to member.isGetter, but the full formulation really ties the triage together + dropFieldAnnotationsFromGetter(clonedAccessor) + + // if we don't cloneInfo, method argument symbols are shared between trait and subclasses --> lambalift proxy crash + // TODO: use derive symbol variant? +// println(s"cloning accessor $member to $clazz") + // start at uncurry so that we preserve that part of the history where an accessor has a NullaryMethodType + enteringUncurry { clonedAccessor setInfo ((clazz.thisType memberType member) cloneInfo clonedAccessor) } + clonedAccessor + } + + // when considering whether to mix in the trait setter, forget about conflicts -- they are reported for the getter + // a trait setter for an overridden val will receive a unit body in the tree transform + if (nme.isTraitSetterName(member.name)) { + val getter = member.getterIn(member.owner) + val clone = cloneAccessor() + + setClonedTraitSetterFlags(clazz, getter, clone) + // println(s"mixed in trait setter ${clone.defString}") + + List(clone) + } + // don't cause conflicts, skip overridden accessors contributed by supertraits (only act on the last overriding one) + // see pos/trait_fields_dependent_conflict.scala and neg/t1960.scala + else if (getterConflictsExistingVal(member) || isOverriddenAccessor(member, clazz)) Nil + else if (member hasFlag MODULE) { + val moduleVar = newModuleVarMember(member) + List(moduleVar, newModuleAccessor(member, clazz, moduleVar)) + } + else if (member hasFlag LAZY) { + val mixedinLazy = cloneAccessor() + val lazyVar = newLazyVarMember(mixedinLazy) // link lazy var member to the mixedin lazy accessor + + // propagate from original member. since mixed in one has only retained the annotations targeting the getter + propagateFieldAnnotations(member, lazyVar) + + // println(s"mixing in lazy var: $lazyVar for $member") + List(lazyVar, accessorSymbolSynth.newSlowPathSymbol(mixedinLazy), newSuperLazy(mixedinLazy, site, lazyVar)) + } + else if (member.isGetter && !fieldMemoizationIn(member, clazz).constantTyped) { + // add field if needed + val field = clazz.newValue(member.localName, member.pos) setInfo fieldTypeForGetterIn(member, clazz.thisType) + + setFieldFlags(member, field) + + propagateFieldAnnotations(member, field) + + List(cloneAccessor(), field) + } else List(cloneAccessor()) // no field needed (constant-typed getter has constant as its RHS) + } + + // println(s"mixedInAccessorAndFields for $clazz: $mixedInAccessorAndFields") + + // omit fields that are not memoized, retain all other members + def omittableField(sym: Symbol) = sym.isValue && !sym.isMethod && fieldMemoizationIn(sym, clazz).constantTyped + + val newDecls = + // under -Xcheckinit we generate all kinds of bitmaps, even when there are no lazy vals + if (expandedModulesAndLazyVals.isEmpty && mixedInAccessorAndFields.isEmpty && !settings.checkInit) + oldDecls.filterNot(omittableField) + else { + // must not alter `decls` directly + val newDecls = newScope + val enter = newDecls enter (_: Symbol) + val enterAll = (_: List[Symbol]) foreach enter + + expandedModulesAndLazyVals foreach enter + oldDecls foreach { d => if (!omittableField(d)) enter(d) } + mixedInAccessorAndFields foreach enterAll + + // both oldDecls and mixedInAccessorAndFields (a list of lists) contribute + val bitmapSyms = accessorSymbolSynth.computeBitmapInfos(newDecls.toList) + + bitmapSyms foreach enter + + newDecls + } + + // println(s"new decls for $clazz: $expandedModules ++ $mixedInAccessorAndFields") + + if (newDecls eq oldDecls) tp + else ClassInfoType(parents, newDecls, clazz) + + case tp => mapOver(tp) + } + } + + + // done by uncurry's info transformer + // instead of forcing every member's info to run said transformer, duplicate the flag update logic... + def nonStaticModuleToMethod(module: Symbol): Unit = + if (!module.isStatic) module setFlag METHOD | STABLE + + // scala/scala-dev#219, scala/scala-dev#268 + // Cast to avoid spurious mismatch in paths containing trait vals that have + // not been rebound to accessors in the subclass we're in now. + // For example, for a lazy val mixed into a class, the lazy var's info + // will not refer to symbols created during our info transformer, + // so if its type depends on a val that is now implemented after the info transformer, + // we'll get a mismatch when assigning `rhs` to `lazyVarOf(getter)`. + // TODO: could we rebind more aggressively? consider overriding in type equality? + def castHack(tree: Tree, pt: Type) = gen.mkAsInstanceOf(tree, pt) + + class FieldsTransformer(unit: CompilationUnit) extends TypingTransformer(unit) with CheckedAccessorTreeSynthesis { + protected def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) + + def mkTypedUnit(pos: Position) = typedPos(pos)(CODE.UNIT) + // TODO: clean up. this method is not used + def deriveUnitDef(stat: Tree) = deriveDefDef(stat)(_ => mkTypedUnit(stat.pos)) + + def mkAccessor(accessor: Symbol)(body: Tree) = typedPos(accessor.pos)(DefDef(accessor, body)).asInstanceOf[DefDef] + + // this makes trees for mixed in fields, as well as for bitmap fields (their RHS will be EmptyTree because they are initialized implicitly) + // if we decide to explicitly initialize, use this RHS: if (symbol.info.typeSymbol.asClass == BooleanClass) FALSE else ZERO) + // could detect it's a bitmap field with something like `sym.name.startsWith(nme.BITMAP_PREFIX)` (or perhaps something more robust...) + def mkTypedValDef(sym: Symbol, rhs: Tree = EmptyTree) = typedPos(sym.pos)(ValDef(sym, rhs)).asInstanceOf[ValDef] + + /** + * Desugar a local `lazy val x: Int = rhs` + * or a local `object x { ...}` (the rhs will be instantiating the module's class) into: + * + * ``` + * val x$lzy = new scala.runtime.LazyInt() + * def x$lzycompute(): Int = + * x$lzy.synchronized { + * if (x$lzy.initialized()) x$lzy.value() + * else x$lzy.initialize(rhs) // for a Unit-typed lazy val, this becomes `{ rhs ; x$lzy.initialize() }` to avoid passing around BoxedUnit + * } + * def x(): Int = if (x$lzy.initialized()) x$lzy.value() else x$lzycompute() + * ``` + * + * The expansion is the same for local lazy vals and local objects, + * except for the suffix of the underlying val's name ($lzy or $module) + */ + private def mkLazyLocalDef(lazySym: Symbol, rhs: Tree): Tree = { + import CODE._ + import scala.reflect.{NameTransformer => nx} + val owner = lazySym.owner + + val lazyValType = lazySym.tpe.resultType + val refClass = lazyHolders.getOrElse(lazyValType.typeSymbol, LazyRefClass) + val isUnit = refClass == LazyUnitClass + val refTpe = if (refClass != LazyRefClass) refClass.tpe else appliedType(refClass.typeConstructor, List(lazyValType)) + + val lazyName = lazySym.name.toTermName + val pos = lazySym.pos.focus + + val localLazyName = lazyName append (if (lazySym.isModule) nx.MODULE_VAR_SUFFIX_STRING else nx.LAZY_LOCAL_SUFFIX_STRING) + + // The lazy holder val need not be mutable, as we write to its field. + // In fact, it MUST not be mutable to avoid capturing it as an ObjectRef in lambdalift + // Must be marked LAZY to allow forward references, as in `def test2 { println(s.length) ; lazy val s = "abc" } + val holderSym = owner.newValue(localLazyName, pos, LAZY | ARTIFACT) setInfo refTpe + + val initializedSym = refTpe.member(nme.initialized) + val initializeSym = refTpe.member(nme.initialize) + + // LazyUnit does not have a `value` member + val valueSym = if (isUnit) NoSymbol else refTpe.member(nme.value) + + def initialized = Select(Ident(holderSym), initializedSym) + def initialize = Select(Ident(holderSym), initializeSym) + def getValue = if (isUnit) UNIT else Apply(Select(Ident(holderSym), valueSym), Nil) + + val computerSym = + owner.newMethod(lazyName append nme.LAZY_SLOW_SUFFIX, pos, ARTIFACT | PRIVATE) setInfo MethodType(Nil, lazyValType) + + val rhsAtComputer = rhs.changeOwner(lazySym -> computerSym) + + val computer = mkAccessor(computerSym)(gen.mkSynchronized(Ident(holderSym))( + If(initialized, getValue, + if (isUnit) Block(rhsAtComputer :: Nil, Apply(initialize, Nil)) + else Apply(initialize, rhsAtComputer :: Nil)))) + + val accessor = mkAccessor(lazySym)( + If(initialized, getValue, + Apply(Ident(computerSym), Nil))) + + // do last! + // remove STABLE: prevent replacing accessor call of type Unit by BoxedUnit.UNIT in erasure + // remove ACCESSOR: prevent constructors from eliminating the method body if the lazy val is + // lifted into a trait (TODO: not sure about the details here) + lazySym.resetFlag(STABLE | ACCESSOR) + + Thicket(mkTypedValDef(holderSym, New(refTpe)) :: computer :: accessor :: Nil) + } + + // synth trees for accessors/fields and trait setters when they are mixed into a class + def fieldsAndAccessors(clazz: Symbol): List[Tree] = { + + // Could be NoSymbol, which denotes an error, but it's refchecks' job to report it (this fallback is for robustness). + // This is the result of overriding a val with a def, so that no field is found in the subclass. + def fieldAccess(accessor: Symbol): Symbol = + afterOwnPhase { clazz.info.decl(accessor.localName) } + + def getterBody(getter: Symbol): Tree = + // accessor created by newMatchingModuleAccessor for a static module that does need an accessor + // (because there's a matching member in a super class) + if (getter.asTerm.referenced.isModule) + mkAccessor(getter)(castHack(Select(This(clazz), getter.asTerm.referenced), getter.info.resultType)) + else { + val fieldMemoization = fieldMemoizationIn(getter, clazz) + // TODO: drop getter for constant? (when we no longer care about producing identical bytecode?) + if (fieldMemoization.constantTyped) mkAccessor(getter)(gen.mkAttributedQualifier(fieldMemoization.tp)) + else fieldAccess(getter) match { + case NoSymbol => EmptyTree + case fieldSel => mkAccessor(getter)(castHack(Select(This(clazz), fieldSel), getter.info.resultType)) + } + } + + // println(s"accessorsAndFieldsNeedingTrees for $templateSym: $accessorsAndFieldsNeedingTrees") + def setterBody(setter: Symbol): Tree = + // trait setter in trait + if (clazz.isTrait) mkAccessor(setter)(EmptyTree) + // trait setter for overridden val in class + else if (checkAndClearOverriddenTraitSetter(setter)) mkAccessor(setter)(mkTypedUnit(setter.pos)) + // trait val/var setter mixed into class + else fieldAccess(setter) match { + case NoSymbol => EmptyTree + case fieldSel => afterOwnPhase { // the assign only type checks after our phase (assignment to val) + mkAccessor(setter)(Assign(Select(This(clazz), fieldSel), castHack(Ident(setter.firstParam), fieldSel.info))) + } + } + + def moduleAccessorBody(module: Symbol): Tree = + // added during synthFieldsAndAccessors using newModuleAccessor + // a module defined in a trait by definition can't be static (it's a member of the trait and thus gets a new instance for every outer instance) + if (clazz.isTrait) mkAccessor(module)(EmptyTree) + // symbol created by newModuleAccessor for a (non-trait) class + else { + mkAccessor(module)(moduleInit(module, moduleOrLazyVarOf(module))) + } + + val synthAccessorInClass = new SynthLazyAccessorsIn(clazz) + def superLazy(getter: Symbol): Tree = { + assert(!clazz.isTrait) + // this contortion was the only way I can get the super select to be type checked correctly.. + // TODO: why does SelectSuper not work? + val selectSuper = Select(Super(This(clazz), tpnme.EMPTY), getter.name) + + val lazyVar = lazyVarOf(getter) + val rhs = castHack(Apply(selectSuper, Nil), lazyVar.info) + + synthAccessorInClass.expandLazyClassMember(lazyVar, getter, rhs) + } + + (afterOwnPhase { clazz.info.decls } toList) filter checkAndClearNeedsTrees map { + case module if module hasAllFlags (MODULE | METHOD) => moduleAccessorBody(module) + case getter if getter hasAllFlags (LAZY | METHOD) => superLazy(getter) + case setter if setter.isSetter => setterBody(setter) + case getter if getter.hasFlag(ACCESSOR) => getterBody(getter) + case field if !(field hasFlag METHOD) => mkTypedValDef(field) // vals/vars and module vars (cannot have flags PACKAGE | JAVA since those never receive NEEDS_TREES) + case _ => EmptyTree + } filterNot (_ == EmptyTree) // there will likely be many EmptyTrees, but perhaps no thicket blocks that need expanding + } + + def rhsAtOwner(stat: ValOrDefDef, newOwner: Symbol): Tree = + atOwner(newOwner)(super.transform(stat.rhs.changeOwner(stat.symbol -> newOwner))) + + override def transform(stat: Tree): Tree = { + val currOwner = currentOwner // often a class, but not necessarily + val statSym = stat.symbol + + /* + For traits, the getter has the val's RHS, which is already constant-folded. There is no valdef. + For classes, we still have the classic scheme of private[this] valdef + getter & setter that read/assign to the field. + + There are two axes: (1) is there a side-effect to the val (2) does the val need storage? + For a ConstantType, both answers are "no". (For a unit-typed field, there's a side-effect, but no storage needed.) + + All others (getter for trait field, valdef for class field) have their rhs moved to an initialization statement. + Trait accessors for stored fields are made abstract (there can be no field in a trait). + (In some future version, accessors for non-stored, but effectful fields, + would receive a constant rhs, as the effect is performed by the initialization statement. + We could do this for unit-typed fields, but have chosen not to for backwards compatibility.) + */ + stat match { + // TODO: consolidate with ValDef case + // TODO: defer replacing ConstantTyped tree by the corresponding constant until erasure + // (until then, trees should not be constant-folded -- only their type tracks the resulting constant) + // also remove ACCESSOR flag since there won't be an underlying field to access? + case DefDef(_, _, _, _, _, rhs) if (statSym hasFlag ACCESSOR) + && (rhs ne EmptyTree) && !excludedAccessorOrFieldByFlags(statSym) + && !currOwner.isTrait // we've already done this for traits.. the asymmetry will be solved by the above todo + && fieldMemoizationIn(statSym, currOwner).constantTyped => + deriveDefDef(stat)(_ => gen.mkAttributedQualifier(rhs.tpe)) + + // deferred val, trait val, lazy val (local or in class) + case vd@ValDef(mods, name, tpt, rhs) if vd.symbol.hasFlag(ACCESSOR) && treeInfo.noFieldFor(vd, currOwner) => + val transformedRhs = atOwner(statSym)(transform(rhs)) + + if (rhs == EmptyTree) mkAccessor(statSym)(EmptyTree) + else if (currOwner.isTrait) mkAccessor(statSym)(castHack(transformedRhs, statSym.info.resultType)) + else if (!currOwner.isClass) mkLazyLocalDef(vd.symbol, transformedRhs) + else { + // TODO: make `synthAccessorInClass` a field and update it in atOwner? + // note that `LazyAccessorTreeSynth` is pretty lightweight + // (it's just a bunch of methods that all take a `clazz` parameter, which is thus stored as a field) + val synthAccessorInClass = new SynthLazyAccessorsIn(currOwner) + synthAccessorInClass.expandLazyClassMember(lazyVarOf(statSym), statSym, transformedRhs) + } + + // drop the val for (a) constant (pure & not-stored) and (b) not-stored (but still effectful) fields + case ValDef(mods, _, _, rhs) if (rhs ne EmptyTree) && !excludedAccessorOrFieldByFlags(statSym) + && currOwner.isClass && fieldMemoizationIn(statSym, currOwner).constantTyped => + EmptyThicket + + case ModuleDef(_, _, impl) => + // ??? The typer doesn't take kindly to seeing this ClassDef; we have to set NoType so it will be ignored. + val cd = super.transform(ClassDef(statSym.moduleClass, impl) setType NoType) + if (currOwner.isClass) cd + else { // local module -- symbols cannot be generated by info transformer, so do it all here + val Block(stats, _) = mkLazyLocalDef(statSym, gen.newModule(statSym, statSym.info.resultType)) + + Thicket(cd :: stats) + } + + case tree => + super.transform(tree) + + } + } + + + def transformTermsAtExprOwner(exprOwner: Symbol)(stat: Tree) = + if (stat.isTerm) atOwner(exprOwner)(transform(stat)) + else transform(stat) + + override def transformStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = { + val addedStats = + if (!currentOwner.isClass || currentOwner.isPackageClass) Nil + else { + val thickets = fieldsAndAccessors(currentOwner) + if (thickets exists mustExplodeThicket) + thickets flatMap explodeThicket + else thickets + } + + val newStats = + stats mapConserve (if (exprOwner != currentOwner) transformTermsAtExprOwner(exprOwner) else transform) + + addedStats ::: (if (newStats eq stats) stats else { + // check whether we need to flatten thickets and drop empty ones + if (newStats exists mustExplodeThicket) + newStats flatMap explodeThicket + else newStats + }) + } + + } +} diff --git a/src/compiler/scala/tools/nsc/transform/Flatten.scala b/src/compiler/scala/tools/nsc/transform/Flatten.scala index fbb0307773..29ba21cba7 100644 --- a/src/compiler/scala/tools/nsc/transform/Flatten.scala +++ b/src/compiler/scala/tools/nsc/transform/Flatten.scala @@ -41,8 +41,6 @@ abstract class Flatten extends InfoTransform { } private def liftSymbol(sym: Symbol) { liftClass(sym) - if (sym.needsImplClass) - liftClass(erasure implClass sym) } // This is a short-term measure partially working around objects being // lifted out of parameterized classes, leaving them referencing @@ -78,7 +76,7 @@ abstract class Flatten extends InfoTransform { decls1 enter sym if (sym.isModule) { // In theory, we could assert(sym.isMethod), because nested, non-static modules are - // transformed to methods (lateMETHOD flag added in RefChecks). But this requires + // transformed to methods (METHOD flag added in UnCurry). But this requires // forcing sym.info (see comment on isModuleNotMethod), which forces stub symbols // too eagerly (SI-8907). diff --git a/src/compiler/scala/tools/nsc/transform/InlineErasure.scala b/src/compiler/scala/tools/nsc/transform/InlineErasure.scala deleted file mode 100644 index 1bbe1b8410..0000000000 --- a/src/compiler/scala/tools/nsc/transform/InlineErasure.scala +++ /dev/null @@ -1,11 +0,0 @@ -package scala.tools.nsc -package transform - -trait InlineErasure { - self: Erasure => - -/* - import global._ - import definitions._ - */ -} diff --git a/src/compiler/scala/tools/nsc/transform/LambdaLift.scala b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala index d1be1558b9..169fe7588e 100644 --- a/src/compiler/scala/tools/nsc/transform/LambdaLift.scala +++ b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala @@ -8,7 +8,7 @@ package transform import symtab._ import Flags._ -import scala.collection.{ mutable, immutable } +import scala.collection.mutable import scala.collection.mutable.{ LinkedHashMap, LinkedHashSet, TreeSet } abstract class LambdaLift extends InfoTransform { @@ -31,11 +31,6 @@ abstract class LambdaLift extends InfoTransform { } } - /** scala.runtime.*Ref classes */ - private lazy val allRefClasses: Set[Symbol] = { - refClass.values.toSet ++ volatileRefClass.values.toSet ++ Set(VolatileObjectRefClass, ObjectRefClass) - } - /** Each scala.runtime.*Ref class has a static method `create(value)` that simply instantiates the Ref to carry that value. */ private lazy val refCreateMethod: Map[Symbol, Symbol] = { mapFrom(allRefClasses.toList)(x => getMemberMethod(x.companionModule, nme.create)) @@ -103,19 +98,37 @@ abstract class LambdaLift extends InfoTransform { */ private val proxyNames = mutable.HashMap[Symbol, Name]() - // (trait, name) -> owner - private val localTraits = mutable.HashMap[(Symbol, Name), Symbol]() - // (owner, name) -> implClass - private val localImplClasses = mutable.HashMap[(Symbol, Name), Symbol]() - /** A flag to indicate whether new free variables have been found */ private var changedFreeVars: Boolean = _ /** Buffers for lifted out classes and methods */ private val liftedDefs = new LinkedHashMap[Symbol, List[Tree]] + val delayedInitDummies = new mutable.HashMap[Symbol, Symbol] + + /** + * For classes capturing locals, LambdaLift uses `local.logicallyEnclosingMember` to decide + * whether an access to the local is re-written to the field or constructor parameter. If the + * access is in a constructor statement, the constructor parameter is used. + * + * For DelayedInit subclasses, constructor statements end up in the synthetic init method + * instead of the constructor itself, so the access should go to the field. This method changes + * `logicallyEnclosingMember` in this case to return a temporary symbol corresponding to that + * method. + */ + private def logicallyEnclosingMember(sym: Symbol): Symbol = { + if (sym.isLocalDummy) { + val enclClass = sym.enclClass + if (enclClass.isSubClass(DelayedInitClass)) + delayedInitDummies.getOrElseUpdate(enclClass, enclClass.newMethod(nme.delayedInit)) + else + enclClass.primaryConstructor + } else if (sym.isMethod || sym.isClass || sym == NoSymbol) sym + else logicallyEnclosingMember(sym.owner) + } + private def isSameOwnerEnclosure(sym: Symbol) = - sym.owner.logicallyEnclosingMember == currentOwner.logicallyEnclosingMember + logicallyEnclosingMember(sym.owner) == logicallyEnclosingMember(currentOwner) /** Mark symbol `sym` as being free in `enclosure`, unless `sym` * is defined in `enclosure` or there is a class between `enclosure`s owner @@ -148,17 +161,17 @@ abstract class LambdaLift extends InfoTransform { * } */ private def markFree(sym: Symbol, enclosure: Symbol): Boolean = { - debuglog("mark free: " + sym.fullLocationString + " marked free in " + enclosure) - (enclosure == sym.owner.logicallyEnclosingMember) || { - debuglog("%s != %s".format(enclosure, sym.owner.logicallyEnclosingMember)) - if (enclosure.isPackageClass || !markFree(sym, enclosure.skipConstructor.owner.logicallyEnclosingMember)) false +// println(s"mark free: ${sym.fullLocationString} marked free in $enclosure") + (enclosure == logicallyEnclosingMember(sym.owner)) || { + debuglog("%s != %s".format(enclosure, logicallyEnclosingMember(sym.owner))) + if (enclosure.isPackageClass || !markFree(sym, logicallyEnclosingMember(enclosure.skipConstructor.owner))) false else { val ss = symSet(free, enclosure) if (!ss(sym)) { ss += sym renamable += sym changedFreeVars = true - debuglog("" + sym + " is free in " + enclosure) + debuglog(s"$sym is free in $enclosure") if (sym.isVariable) sym setFlag CAPTURED } !enclosure.isClass @@ -167,7 +180,7 @@ abstract class LambdaLift extends InfoTransform { } private def markCalled(sym: Symbol, owner: Symbol) { - debuglog("mark called: " + sym + " of " + sym.owner + " is called by " + owner) +// println(s"mark called: $sym of ${sym.owner} is called by $owner") symSet(called, owner) += sym if (sym.enclClass != owner.enclClass) calledFromInner += sym } @@ -175,30 +188,13 @@ abstract class LambdaLift extends InfoTransform { /** The traverse function */ private val freeVarTraverser = new Traverser { override def traverse(tree: Tree) { - try { //debug +// try { //debug val sym = tree.symbol tree match { case ClassDef(_, _, _, _) => liftedDefs(tree.symbol) = Nil if (sym.isLocalToBlock) { - // Don't rename implementation classes independently of their interfaces. If - // the interface is to be renamed, then we will rename the implementation - // class at that time. You'd think we could call ".implClass" on the trait - // rather than collecting them in another map, but that seems to fail for - // exactly the traits being renamed here (i.e. defined in methods.) - // - // !!! - it makes no sense to have methods like "implClass" and - // "companionClass" which fail for an arbitrary subset of nesting - // arrangements, and then have separate methods which attempt to compensate - // for that failure. There should be exactly one method for any given - // entity which always gives the right answer. - if (sym.isImplClass) - localImplClasses((sym.owner, tpnme.interfaceName(sym.name))) = sym - else { - renamable += sym - if (sym.isTrait) - localTraits((sym, sym.name)) = sym.owner - } + renamable += sym } case DefDef(_, _, _, _, _, _) => if (sym.isLocalToBlock) { @@ -211,22 +207,22 @@ abstract class LambdaLift extends InfoTransform { if (sym == NoSymbol) { assert(name == nme.WILDCARD) } else if (sym.isLocalToBlock) { - val owner = currentOwner.logicallyEnclosingMember + val owner = logicallyEnclosingMember(currentOwner) if (sym.isTerm && !sym.isMethod) markFree(sym, owner) else if (sym.isMethod) markCalled(sym, owner) //symSet(called, owner) += sym } case Select(_, _) => if (sym.isConstructor && sym.owner.isLocalToBlock) - markCalled(sym, currentOwner.logicallyEnclosingMember) + markCalled(sym, logicallyEnclosingMember(currentOwner)) case _ => } super.traverse(tree) - } catch {//debug - case ex: Throwable => - Console.println(s"$ex while traversing $tree") - throw ex - } +// } catch {//debug +// case ex: Throwable => +// Console.println(s"$ex while traversing $tree") +// throw ex +// } } } @@ -240,7 +236,7 @@ abstract class LambdaLift extends InfoTransform { do { changedFreeVars = false - for (caller <- called.keys ; callee <- called(caller) ; fvs <- free get callee ; fv <- fvs) + for ((caller, callees) <- called ; callee <- callees ; fvs <- free get callee ; fv <- fvs) markFree(fv, caller) } while (changedFreeVars) @@ -250,11 +246,6 @@ abstract class LambdaLift extends InfoTransform { debuglog("renaming in %s: %s => %s".format(sym.owner.fullLocationString, originalName, sym.name)) } - // make sure that the name doesn't make the symbol accidentally `isAnonymousClass` (et.al) by - // introducing `$anon` in its name. to be cautious, we don't make this change in the default - // backend under 2.11.x, so only in GenBCode. - def nonAnon(s: String) = if (settings.Ybackend.value == "GenBCode") nme.ensureNonAnon(s) else s - def newName(sym: Symbol): Name = { val originalName = sym.name def freshen(prefix: String): Name = @@ -263,57 +254,49 @@ abstract class LambdaLift extends InfoTransform { val join = nme.NAME_JOIN_STRING if (sym.isAnonymousFunction && sym.owner.isMethod) { - freshen(sym.name + join + nonAnon(sym.owner.name.toString) + join) + freshen(sym.name + join + nme.ensureNonAnon(sym.owner.name.toString) + join) } else { val name = freshen(sym.name + join) // SI-5652 If the lifted symbol is accessed from an inner class, it will be made public. (where?) // Generating a unique name, mangled with the enclosing full class name (including // package - subclass might have the same name), avoids a VerifyError in the case // that a sub-class happens to lifts out a method with the *same* name. - if (originalName.isTermName && !sym.enclClass.isImplClass && calledFromInner(sym)) - newTermNameCached(nonAnon(sym.enclClass.fullName('$')) + nme.EXPAND_SEPARATOR_STRING + name) + if (originalName.isTermName && calledFromInner(sym)) + newTermNameCached(nme.ensureNonAnon(sym.enclClass.fullName('$')) + nme.EXPAND_SEPARATOR_STRING + name) else name } } - /* Rename a trait's interface and implementation class in coordinated fashion. */ - def renameTrait(traitSym: Symbol, implSym: Symbol) { - val originalImplName = implSym.name - renameSym(traitSym) - implSym setName tpnme.implClassName(traitSym.name) - - debuglog("renaming impl class in step with %s: %s => %s".format(traitSym, originalImplName, implSym.name)) - } - val allFree: Set[Symbol] = free.values.flatMap(_.iterator).toSet for (sym <- renamable) { - // If we renamed a trait from Foo to Foo$1, we must rename the implementation - // class from Foo$class to Foo$1$class. (Without special consideration it would - // become Foo$class$1 instead.) Since the symbols are being renamed out from - // under us, and there's no reliable link between trait symbol and impl symbol, - // we have maps from ((trait, name)) -> owner and ((owner, name)) -> impl. - localTraits remove ((sym, sym.name)) match { - case None => - if (allFree(sym)) proxyNames(sym) = newName(sym) - else renameSym(sym) - case Some(owner) => - localImplClasses remove ((owner, sym.name)) match { - case Some(implSym) => renameTrait(sym, implSym) - case _ => renameSym(sym) // pure interface, no impl class - } - } + if (allFree(sym)) proxyNames(sym) = newName(sym) + else renameSym(sym) } afterOwnPhase { for ((owner, freeValues) <- free.toList) { - val newFlags = SYNTHETIC | ( if (owner.isClass) PARAMACCESSOR | PrivateLocal else PARAM ) - debuglog("free var proxy: %s, %s".format(owner.fullLocationString, freeValues.toList.mkString(", "))) + val newFlags = SYNTHETIC | (if (owner.isClass) PARAMACCESSOR else PARAM) + proxies(owner) = for (fv <- freeValues.toList) yield { val proxyName = proxyNames.getOrElse(fv, fv.name) - val proxy = owner.newValue(proxyName.toTermName, owner.pos, newFlags.toLong) setInfo fv.info + debuglog(s"new proxy ${proxyName} in ${owner.fullLocationString}") + val proxy = + if (owner.isTrait) { + val accessorFlags = newFlags.toLong | ACCESSOR | SYNTHESIZE_IMPL_IN_SUBCLASS + + // TODO do we need to preserve pre-erasure info for the accessors (and a NullaryMethodType for the getter)? + // can't have a field in the trait, so add a setter + val setter = owner.newMethod(nme.expandedSetterName(proxyName.setterName, owner), fv.pos, accessorFlags) + setter setInfoAndEnter MethodType(setter.newSyntheticValueParams(List(fv.info)), UnitTpe) + + // the getter serves as the proxy -- entered below + owner.newMethod(proxyName.getterName, fv.pos, accessorFlags | STABLE) setInfo MethodType(Nil, fv.info) + } else + owner.newValue(proxyName.toTermName, fv.pos, newFlags.toLong | PrivateLocal) setInfo fv.info + if (owner.isClass) owner.info.decls enter proxy proxy } @@ -323,17 +306,18 @@ abstract class LambdaLift extends InfoTransform { private def proxy(sym: Symbol) = { def searchIn(enclosure: Symbol): Symbol = { - if (enclosure eq NoSymbol) throw new IllegalArgumentException("Could not find proxy for "+ sym.defString +" in "+ sym.ownerChain +" (currentOwner= "+ currentOwner +" )") - debuglog("searching for " + sym + "(" + sym.owner + ") in " + enclosure + " " + enclosure.logicallyEnclosingMember) + if (enclosure eq NoSymbol) + throw new IllegalArgumentException("Could not find proxy for "+ sym.defString +" in "+ sym.ownerChain +" (currentOwner= "+ currentOwner +" )") + debuglog("searching for " + sym + "(" + sym.owner + ") in " + enclosure + " " + logicallyEnclosingMember(enclosure)) val proxyName = proxyNames.getOrElse(sym, sym.name) - val ps = (proxies get enclosure.logicallyEnclosingMember).toList.flatten find (_.name == proxyName) + val ps = (proxies get logicallyEnclosingMember(enclosure)).toList.flatten find (_.name == proxyName) ps getOrElse searchIn(enclosure.skipConstructor.owner) } debuglog("proxy %s from %s has logical enclosure %s".format( sym.debugLocationString, currentOwner.debugLocationString, - sym.owner.logicallyEnclosingMember.debugLocationString) + logicallyEnclosingMember(sym.owner).debugLocationString) ) if (isSameOwnerEnclosure(sym)) sym @@ -342,73 +326,96 @@ abstract class LambdaLift extends InfoTransform { private def memberRef(sym: Symbol): Tree = { val clazz = sym.owner.enclClass - //Console.println("memberRef from "+currentClass+" to "+sym+" in "+clazz) - def prematureSelfReference() { + // println(s"memberRef from $currentClass to $sym in $clazz (currentClass=$currentClass)") + def prematureSelfReference(): Tree = { val what = if (clazz.isStaticOwner) clazz.fullLocationString else s"the unconstructed `this` of ${clazz.fullLocationString}" val msg = s"Implementation restriction: access of ${sym.fullLocationString} from ${currentClass.fullLocationString}, would require illegal premature access to $what" reporter.error(curTree.pos, msg) + EmptyTree } - val qual = + def qual = if (clazz == currentClass) gen.mkAttributedThis(clazz) else { sym resetFlag (LOCAL | PRIVATE) - if (isUnderConstruction(clazz)) { - prematureSelfReference() - EmptyTree - } + if (isUnderConstruction(clazz)) prematureSelfReference() else if (clazz.isStaticOwner) gen.mkAttributedQualifier(clazz.thisType) - else { - outerValue match { - case EmptyTree => prematureSelfReference(); return EmptyTree - case o => outerPath(o, currentClass.outerClass, clazz) - } + else outerValue match { + case EmptyTree => prematureSelfReference() + case o => + val path = outerPath(o, currentClass.outerClass, clazz) + if (path.tpe <:< clazz.tpeHK) path + else { + // SI-9920 The outer accessor might have an erased type of the self type of a trait, + // rather than the trait itself. Add a cast if necessary. + gen.mkAttributedCast(path, clazz.tpeHK) + } } } - Select(qual, sym) setType sym.tpe + + qual match { + case EmptyTree => EmptyTree + case qual => Select(qual, sym) setType sym.tpe + } } private def proxyRef(sym: Symbol) = { val psym = proxy(sym) - if (psym.isLocalToBlock) gen.mkAttributedIdent(psym) else memberRef(psym) + if (psym.isLocalToBlock) gen.mkAttributedIdent(psym) + else { + val ref = memberRef(psym) + if (psym.isMethod) Apply(ref, Nil) setType ref.tpe.resultType + else ref + } } - private def addFreeArgs(pos: Position, sym: Symbol, args: List[Tree]) = { - free get sym match { - case Some(fvs) => addFree(sym, free = fvs.toList map (fv => atPos(pos)(proxyRef(fv))), original = args) - case _ => args + def freeArgsOrNil(sym: Symbol) = free.getOrElse(sym, Nil).toList + + private def freeArgs(sym: Symbol): List[Symbol] = + freeArgsOrNil(sym) + + private def addFreeArgs(pos: Position, sym: Symbol, args: List[Tree]) = + freeArgs(sym) match { + case Nil => args + case fvs => addFree(sym, free = fvs map (fv => atPos(pos)(proxyRef(fv))), original = args) } - } - private def addFreeParams(tree: Tree, sym: Symbol): Tree = proxies.get(sym) match { - case Some(ps) => - val freeParams = ps map (p => ValDef(p) setPos tree.pos setType NoType) - tree match { - case DefDef(_, _, _, vparams :: _, _, _) => - val addParams = cloneSymbols(ps).map(_.setFlag(PARAM)) - sym.updateInfo( - lifted(MethodType(addFree(sym, free = addParams, original = sym.info.params), sym.info.resultType))) + def proxiesOrNil(sym: Symbol) = proxies.getOrElse(sym, Nil) + + private def freeParams(sym: Symbol): List[Symbol] = + proxiesOrNil(sym) + + private def addFreeParams(tree: Tree, sym: Symbol): Tree = + tree match { + case DefDef(_, _, _, vparams :: _, _, _) => + val ps = freeParams(sym) + + if (ps.isEmpty) tree + else { + val paramSyms = cloneSymbols(ps).map(_.setFlag(PARAM)) + val paramDefs = ps map (p => ValDef(p) setPos tree.pos setType NoType) + + sym.updateInfo(lifted(MethodType(addFree(sym, free = paramSyms, original = sym.info.params), sym.info.resultType))) + copyDefDef(tree)(vparamss = List(addFree(sym, free = paramDefs, original = vparams))) + } + + case ClassDef(_, _, _, _) => + val freeParamSyms = freeParams(sym) + val freeParamDefs = + if (tree.symbol.isTrait) { + freeParamSyms flatMap { getter => + val setter = getter.setterIn(tree.symbol, hasExpandedName = true) + List(DefDef(getter, EmptyTree) setPos tree.pos setType NoType, DefDef(setter, EmptyTree) setPos tree.pos setType NoType) + } + } else freeParamSyms map (p => ValDef(p) setPos tree.pos setType NoType) + + if (freeParamDefs.isEmpty) tree + else deriveClassDef(tree)(impl => deriveTemplate(impl)(_ ::: freeParamDefs)) + + case _ => tree + } - copyDefDef(tree)(vparamss = List(addFree(sym, free = freeParams, original = vparams))) - case ClassDef(_, _, _, _) => - // SI-6231 - // Disabled attempt to to add getters to freeParams - // this does not work yet. Problem is that local symbols need local names - // and references to local symbols need to be transformed into - // method calls to setters. - // def paramGetter(param: Symbol): Tree = { - // val getter = param.newGetter setFlag TRANS_FLAG resetFlag PARAMACCESSOR // mark because we have to add them to interface - // sym.info.decls.enter(getter) - // val rhs = Select(gen.mkAttributedThis(sym), param) setType param.tpe - // DefDef(getter, rhs) setPos tree.pos setType NoType - // } - // val newDefs = if (sym.isTrait) freeParams ::: (ps map paramGetter) else freeParams - deriveClassDef(tree)(impl => deriveTemplate(impl)(_ ::: freeParams)) - } - case None => - tree - } /* SI-6231: Something like this will be necessary to eliminate the implementation * restriction from paramGetter above: @@ -451,11 +458,10 @@ abstract class LambdaLift extends InfoTransform { // See neg/t1909-object.scala def msg = s"SI-1909 Unable to STATICally lift $sym, which is defined in the self- or super-constructor call of ${sym.owner.owner}. A VerifyError is likely." devWarning(tree.pos, msg) - } else sym setFlag STATIC + } else sym setFlag STATIC } sym.owner = sym.owner.enclClass - if (sym.isClass) sym.owner = sym.owner.toInterface if (sym.isMethod) sym setFlag LIFTED liftedDefs(sym.owner) ::= tree // TODO: this modifies the ClassInfotype of the enclosing class, which is associated with another phase (explicitouter). @@ -468,12 +474,11 @@ abstract class LambdaLift extends InfoTransform { private def postTransform(tree: Tree, isBoxedRef: Boolean = false): Tree = { val sym = tree.symbol tree match { - case ClassDef(_, _, _, _) => - val tree1 = addFreeParams(tree, sym) - if (sym.isLocalToBlock) liftDef(tree1) else tree1 - case DefDef(_, _, _, _, _, _) => - val tree1 = addFreeParams(tree, sym) - if (sym.isLocalToBlock) liftDef(tree1) else tree1 + case _: ClassDef | _: DefDef => + val withFreeParams = addFreeParams(tree, sym) + if (sym.isLocalToBlock) liftDef(withFreeParams) + else withFreeParams + case ValDef(mods, name, tpt, rhs) => if (sym.isCapturedVariable) { val tpt1 = TypeTree(sym.tpe) setPos tpt.pos diff --git a/src/compiler/scala/tools/nsc/transform/LazyVals.scala b/src/compiler/scala/tools/nsc/transform/LazyVals.scala deleted file mode 100644 index b6695efb0b..0000000000 --- a/src/compiler/scala/tools/nsc/transform/LazyVals.scala +++ /dev/null @@ -1,293 +0,0 @@ -package scala.tools.nsc -package transform - -import scala.collection.{ mutable, immutable } - -abstract class LazyVals extends Transform with TypingTransformers with ast.TreeDSL { - // inherits abstract value `global` and class `Phase` from Transform - - import global._ // the global environment - import definitions._ // standard classes and methods - import typer.{typed, atOwner} // methods to type trees - import CODE._ - - val phaseName: String = "lazyvals" - private val FLAGS_PER_BYTE: Int = 8 // Byte - private def bitmapKind = ByteClass - - def newTransformer(unit: CompilationUnit): Transformer = - new LazyValues(unit) - - private def lazyUnit(sym: Symbol) = sym.tpe.resultType.typeSymbol == UnitClass - - object LocalLazyValFinder extends Traverser { - var result: Boolean = _ - - def find(t: Tree) = {result = false; traverse(t); result} - def find(ts: List[Tree]) = {result = false; traverseTrees(ts); result} - - override def traverse(t: Tree) { - if (!result) - t match { - case v@ValDef(_, _, _, _) if v.symbol.isLazy => - result = true - - case d@DefDef(_, _, _, _, _, _) if d.symbol.isLazy && lazyUnit(d.symbol) => - d.symbol.resetFlag(symtab.Flags.LAZY) - result = true - - case ClassDef(_, _, _, _) | DefDef(_, _, _, _, _, _) | ModuleDef(_, _, _) => - - case LabelDef(name, _, _) if nme.isLoopHeaderLabel(name) => - - case _ => - super.traverse(t) - } - } - } - - /** - * Transform local lazy accessors to check for the initialized bit. - */ - class LazyValues(unit: CompilationUnit) extends TypingTransformer(unit) { - /** map from method symbols to the number of lazy values it defines. */ - private val lazyVals = perRunCaches.newMap[Symbol, Int]() withDefaultValue 0 - - import symtab.Flags._ - - /** Perform the following transformations: - * - for a lazy accessor inside a method, make it check the initialization bitmap - * - for all methods, add enough int vars to allow one flag per lazy local value - * - blocks in template bodies behave almost like methods. A single bitmaps section is - * added in the first block, for all lazy values defined in such blocks. - * - remove ACCESSOR flags: accessors in traits are not statically implemented, - * but moved to the host class. local lazy values should be statically implemented. - */ - override def transform(tree: Tree): Tree = { - val sym = tree.symbol - curTree = tree - - tree match { - - case Block(_, _) => - val block1 = super.transform(tree) - val Block(stats, expr) = block1 - val stats1 = stats.flatMap(_ match { - case Block(List(d1@DefDef(_, n1, _, _, _, _)), d2@DefDef(_, n2, _, _, _, _)) if (nme.newLazyValSlowComputeName(n2) == n1) => - List(d1, d2) - case stat => - List(stat) - }) - treeCopy.Block(block1, stats1, expr) - - case DefDef(_, _, _, _, _, rhs) => atOwner(tree.symbol) { - val (res, slowPathDef) = if (!sym.owner.isClass && sym.isLazy) { - val enclosingClassOrDummyOrMethod = { - val enclMethod = sym.enclMethod - - if (enclMethod != NoSymbol ) { - val enclClass = sym.enclClass - if (enclClass != NoSymbol && enclMethod == enclClass.enclMethod) - enclClass - else - enclMethod - } else - sym.owner - } - debuglog(s"determined enclosing class/dummy/method for lazy val as $enclosingClassOrDummyOrMethod given symbol $sym") - val idx = lazyVals(enclosingClassOrDummyOrMethod) - lazyVals(enclosingClassOrDummyOrMethod) = idx + 1 - val (rhs1, sDef) = mkLazyDef(enclosingClassOrDummyOrMethod, transform(rhs), idx, sym) - sym.resetFlag((if (lazyUnit(sym)) 0 else LAZY) | ACCESSOR) - (rhs1, sDef) - } else - (transform(rhs), EmptyTree) - - val ddef1 = deriveDefDef(tree)(_ => if (LocalLazyValFinder.find(res)) typed(addBitmapDefs(sym, res)) else res) - if (slowPathDef != EmptyTree) Block(slowPathDef, ddef1) else ddef1 - } - - case Template(_, _, body) => atOwner(currentOwner) { - val body1 = super.transformTrees(body) - var added = false - val stats = - for (stat <- body1) yield stat match { - case Block(_, _) | Apply(_, _) | If(_, _, _) | Try(_, _, _) if !added => - // Avoid adding bitmaps when they are fully overshadowed by those - // that are added inside loops - if (LocalLazyValFinder.find(stat)) { - added = true - typed(addBitmapDefs(sym, stat)) - } else stat - case ValDef(_, _, _, _) => - typed(deriveValDef(stat)(addBitmapDefs(stat.symbol, _))) - case _ => - stat - } - val innerClassBitmaps = if (!added && currentOwner.isClass && bitmaps.contains(currentOwner)) { - // add bitmap to inner class if necessary - val toAdd0 = bitmaps(currentOwner).map(s => typed(ValDef(s, ZERO))) - toAdd0.foreach(t => { - if (currentOwner.info.decl(t.symbol.name) == NoSymbol) { - t.symbol.setFlag(PROTECTED) - currentOwner.info.decls.enter(t.symbol) - } - }) - toAdd0 - } else List() - deriveTemplate(tree)(_ => innerClassBitmaps ++ stats) - } - - case ValDef(_, _, _, _) if !sym.owner.isModule && !sym.owner.isClass => - deriveValDef(tree) { rhs0 => - val rhs = transform(rhs0) - if (LocalLazyValFinder.find(rhs)) typed(addBitmapDefs(sym, rhs)) else rhs - } - - case l@LabelDef(name0, params0, ifp0@If(_, _, _)) if name0.startsWith(nme.WHILE_PREFIX) => - val ifp1 = super.transform(ifp0) - val If(cond0, thenp0, elsep0) = ifp1 - - if (LocalLazyValFinder.find(thenp0)) - deriveLabelDef(l)(_ => treeCopy.If(ifp1, cond0, typed(addBitmapDefs(sym.owner, thenp0)), elsep0)) - else - l - - case l@LabelDef(name0, params0, block@Block(stats0, expr)) - if name0.startsWith(nme.WHILE_PREFIX) || name0.startsWith(nme.DO_WHILE_PREFIX) => - val stats1 = super.transformTrees(stats0) - if (LocalLazyValFinder.find(stats1)) - deriveLabelDef(l)(_ => treeCopy.Block(block, typed(addBitmapDefs(sym.owner, stats1.head))::stats1.tail, expr)) - else - l - - case _ => super.transform(tree) - } - } - - /** Add the bitmap definitions to the rhs of a method definition. - * If the rhs has been tail-call transformed, insert the bitmap - * definitions inside the top-level label definition, so that each - * iteration has the lazy values uninitialized. Otherwise add them - * at the very beginning of the method. - */ - private def addBitmapDefs(methSym: Symbol, rhs: Tree): Tree = { - def prependStats(stats: List[Tree], tree: Tree): Block = tree match { - case Block(stats1, res) => Block(stats ::: stats1, res) - case _ => Block(stats, tree) - } - - val bmps = bitmaps(methSym) map (ValDef(_, ZERO)) - - def isMatch(params: List[Ident]) = (params.tail corresponds methSym.tpe.params)(_.tpe == _.tpe) - - if (bmps.isEmpty) rhs else rhs match { - case Block(assign, l @ LabelDef(name, params, _)) - if (name string_== "_" + methSym.name) && isMatch(params) => - Block(assign, deriveLabelDef(l)(rhs => typed(prependStats(bmps, rhs)))) - - case _ => prependStats(bmps, rhs) - } - } - - def mkSlowPathDef(clazz: Symbol, lzyVal: Symbol, cond: Tree, syncBody: List[Tree], - stats: List[Tree], retVal: Tree): Tree = { - // Q: is there a reason to first set owner to `clazz` (by using clazz.newMethod), and then - // changing it to lzyVal.owner very soon after? Could we just do lzyVal.owner.newMethod? - val defSym = clazz.newMethod(nme.newLazyValSlowComputeName(lzyVal.name.toTermName), lzyVal.pos, STABLE | PRIVATE) - defSym setInfo MethodType(List(), lzyVal.tpe.resultType) - defSym.owner = lzyVal.owner - debuglog(s"crete slow compute path $defSym with owner ${defSym.owner} for lazy val $lzyVal") - if (bitmaps.contains(lzyVal)) - bitmaps(lzyVal).map(_.owner = defSym) - val rhs: Tree = gen.mkSynchronizedCheck(clazz, cond, syncBody, stats).changeOwner(currentOwner -> defSym) - - DefDef(defSym, addBitmapDefs(lzyVal, BLOCK(rhs, retVal))) - } - - - def mkFastPathBody(clazz: Symbol, lzyVal: Symbol, cond: Tree, syncBody: List[Tree], - stats: List[Tree], retVal: Tree): (Tree, Tree) = { - val slowPathDef: Tree = mkSlowPathDef(clazz, lzyVal, cond, syncBody, stats, retVal) - (If(cond, Apply(Ident(slowPathDef.symbol), Nil), retVal), slowPathDef) - } - - /** return a 'lazified' version of rhs. Rhs should conform to the - * following schema: - * { - * l$ = <rhs> - * l$ - * } or - * <rhs> when the lazy value has type Unit (for which there is no field - * to cache its value. - * - * Similarly as for normal lazy val members (see Mixin), the result will be a tree of the form - * { if ((bitmap&n & MASK) == 0) this.l$compute() - * else l$ - * - * def l$compute() = { synchronized(enclosing_class_or_dummy) { - * if ((bitmap$n & MASK) == 0) { - * l$ = <rhs> - * bitmap$n = bimap$n | MASK - * }} - * l$ - * } - * } - * where bitmap$n is a byte value acting as a bitmap of initialized values. It is - * the 'n' is (offset / 8), the MASK is (1 << (offset % 8)). If the value has type - * unit, no field is used to cache the value, so the l$compute will now look as following: - * { - * def l$compute() = { synchronized(enclosing_class_or_dummy) { - * if ((bitmap$n & MASK) == 0) { - * <rhs>; - * bitmap$n = bimap$n | MASK - * }} - * () - * } - * } - */ - private def mkLazyDef(methOrClass: Symbol, tree: Tree, offset: Int, lazyVal: Symbol): (Tree, Tree) = { - val bitmapSym = getBitmapFor(methOrClass, offset) - val mask = LIT(1 << (offset % FLAGS_PER_BYTE)) - val bitmapRef = if (methOrClass.isClass) Select(This(methOrClass), bitmapSym) else Ident(bitmapSym) - - def mkBlock(stmt: Tree) = BLOCK(stmt, mkSetFlag(bitmapSym, mask, bitmapRef), UNIT) - - debuglog(s"create complete lazy def in $methOrClass for $lazyVal") - val (block, res) = tree match { - case Block(List(assignment), res) if !lazyUnit(lazyVal) => - (mkBlock(assignment), res) - case rhs => - (mkBlock(rhs), UNIT) - } - - val cond = (bitmapRef GEN_& (mask, bitmapKind)) GEN_== (ZERO, bitmapKind) - val lazyDefs = mkFastPathBody(methOrClass.enclClass, lazyVal, cond, List(block), Nil, res) - (atPos(tree.pos)(localTyper.typed {lazyDefs._1 }), atPos(tree.pos)(localTyper.typed {lazyDefs._2 })) - } - - private def mkSetFlag(bmp: Symbol, mask: Tree, bmpRef: Tree): Tree = - bmpRef === (bmpRef GEN_| (mask, bitmapKind)) - - val bitmaps = mutable.Map[Symbol, List[Symbol]]() withDefaultValue Nil - - /** Return the symbol corresponding of the right bitmap int inside meth, - * given offset. - */ - private def getBitmapFor(meth: Symbol, offset: Int): Symbol = { - val n = offset / FLAGS_PER_BYTE - val bmps = bitmaps(meth) - if (bmps.length > n) - bmps(n) - else { - val sym = meth.newVariable(nme.newBitmapName(nme.BITMAP_NORMAL, n), meth.pos).setInfo(ByteTpe) - enteringTyper { - sym addAnnotation VolatileAttr - } - - bitmaps(meth) = (sym :: bmps).reverse - sym - } - } - } -} diff --git a/src/compiler/scala/tools/nsc/transform/Mixin.scala b/src/compiler/scala/tools/nsc/transform/Mixin.scala index a079a76ce7..96e2135c52 100644 --- a/src/compiler/scala/tools/nsc/transform/Mixin.scala +++ b/src/compiler/scala/tools/nsc/transform/Mixin.scala @@ -1,5 +1,6 @@ /* NSC -- new Scala compiler - * Copyright 2005-2013 LAMP/EPFL + * Copyright 2005-2016 LAMP/EPFL and Lightbend, Inc + * * @author Martin Odersky */ @@ -8,110 +9,85 @@ package transform import symtab._ import Flags._ -import scala.collection.{ mutable, immutable } +import scala.annotation.tailrec +import scala.collection.mutable -abstract class Mixin extends InfoTransform with ast.TreeDSL { + +abstract class Mixin extends InfoTransform with ast.TreeDSL with AccessorSynthesis { import global._ import definitions._ import CODE._ + /** The name of the phase: */ val phaseName: String = "mixin" - /** The phase might set the following new flags: */ - override def phaseNewFlags: Long = lateMODULE | notOVERRIDE + /** Some trait methods need to be implemented in subclasses, so they cannot be private. + * + * We used to publicize during explicitouter (for some reason), so the condition is a bit more involved now it's done here + * (need to exclude lambdaLIFTED methods, as they do no exist during explicitouter and thus did not need to be excluded...) + * + * They may be protected, now that traits are compiled 1:1 to interfaces. + * The same disclaimers about mapping Scala's notion of visibility to Java's apply: + * we cannot emit PROTECTED methods in interfaces on the JVM, + * but knowing that these trait methods are protected means we won't emit static forwarders. + * + * JVMS: "Methods of interfaces may have any of the flags in Table 4.6-A set + * except ACC_PROTECTED, ACC_FINAL, ACC_SYNCHRONIZED, and ACC_NATIVE (JLS §9.4)." + * + * TODO: can we just set the right flags from the start?? + * could we use the final flag to indicate a private method is really-really-private? + */ + def publicizeTraitMethod(sym: Symbol): Unit = { + if ((sym hasFlag PRIVATE) && !(sym hasFlag LIFTED) && ( // lambdalifted methods can remain private + // super accessors by definition must be implemented in a subclass, so can't be private + // TODO: why are they ever private in a trait to begin with!?!? (could just name mangle them to begin with) + // TODO: can we add the SYNTHESIZE_IMPL_IN_SUBCLASS flag to super accessors symbols? + (sym hasFlag SUPERACCESSOR) + // an accessor / module *may* need to be implemented in a subclass, and thus cannot be private + // TODO: document how we get here (lambdalift? fields has already made accessors not-private) + || (sym hasFlag ACCESSOR | MODULE) && (sym hasFlag SYNTHESIZE_IMPL_IN_SUBCLASS))) + sym.makeNotPrivate(sym.owner) + + // no need to make trait methods not-protected + // (we used to have to move them to another class when interfaces could not have concrete methods) + // see note in `synthFieldsAndAccessors` in Fields.scala + // if (sym hasFlag PROTECTED) sym setFlag notPROTECTED + } /** This map contains a binding (class -> info) if * the class with this info at phase mixinPhase has been treated for mixin composition */ private val treatedClassInfos = perRunCaches.newMap[Symbol, Type]() withDefaultValue NoType - /** Map a lazy, mixedin field accessor to its trait member accessor */ - private val initializer = perRunCaches.newMap[Symbol, Symbol]() // --------- helper functions ----------------------------------------------- /** A member of a trait is implemented statically if its implementation after the - * mixin transform is in the static implementation module. To be statically - * implemented, a member must be a method that belonged to the trait's implementation class + * mixin transform is RHS of the method body (destined to be in an interface default method) + * + * To be statically implemented, a member must be a method that belonged to the trait's implementation class * before (i.e. it is not abstract). Not statically implemented are * - non-private modules: these are implemented directly in the mixin composition class * (private modules, on the other hand, are implemented statically, but their * module variable is not. all such private modules are lifted, because * non-lifted private modules have been eliminated in ExplicitOuter) - * - field accessors and superaccessors, except for lazy value accessors which become initializer - * methods in the impl class (because they can have arbitrary initializers) + * - field accessors and superaccessors */ private def isImplementedStatically(sym: Symbol) = ( - sym.owner.isImplClass - && sym.isMethod + (sym.isMethod || ((sym hasFlag MODULE) && !sym.isStatic)) + // TODO: ^^^ non-static modules should have been turned into methods by fields by now, no? maybe the info transformer hasn't run??? + && notDeferred(sym) + && sym.owner.isTrait && (!sym.isModule || sym.hasFlag(PRIVATE | LIFTED)) - && (!(sym hasFlag (ACCESSOR | SUPERACCESSOR)) || sym.isLazy) - ) - - /** A member of a trait is static only if it belongs only to the - * implementation class, not the interface, and it is implemented - * statically. - */ - private def isStaticOnly(sym: Symbol) = - isImplementedStatically(sym) && sym.isImplOnly - - /** A member of a trait is forwarded if it is implemented statically and it - * is also visible in the trait's interface. In that case, a forwarder to - * the member's static implementation will be added to the class that - * inherits the trait. - */ - private def isForwarded(sym: Symbol) = - isImplementedStatically(sym) && !sym.isImplOnly - - /** Maps the type of an implementation class to its interface; - * maps all other types to themselves. - */ - private def toInterface(tp: Type): Type = - enteringMixin(tp.typeSymbol.toInterface).tpe - - private def isFieldWithBitmap(field: Symbol) = { - field.info // ensure that nested objects are transformed - // For checkinit consider normal value getters - // but for lazy values only take into account lazy getters - field.isLazy && field.isMethod && !field.isDeferred - } - - /** Does this field require an initialized bit? - * Note: fields of classes inheriting DelayedInit are not checked. - * This is because they are neither initialized in the constructor - * nor do they have a setter (not if they are vals anyway). The usual - * logic for setting bitmaps does therefore not work for such fields. - * That's why they are excluded. - * Note: The `checkinit` option does not check if transient fields are initialized. - */ - private def needsInitFlag(sym: Symbol) = ( - settings.checkInit - && sym.isGetter - && !sym.isInitializedToDefault - && !isConstantType(sym.info.finalResultType) // SI-4742 - && !sym.hasFlag(PARAMACCESSOR | SPECIALIZED | LAZY) - && !sym.accessed.hasFlag(PRESUPER) - && !sym.isOuterAccessor - && !(sym.owner isSubClass DelayedInitClass) - && !(sym.accessed hasAnnotation TransientAttr) + && (!(sym hasFlag (ACCESSOR | SUPERACCESSOR)) || (sym hasFlag LAZY)) + && !sym.isPrivate + && !sym.hasAllFlags(LIFTED | MODULE | METHOD) + && !sym.isConstructor + && (!sym.hasFlag(notPRIVATE | LIFTED) || sym.hasFlag(ACCESSOR | SUPERACCESSOR | MODULE)) ) - /** Maps all parts of this type that refer to implementation classes to - * their corresponding interfaces. - */ - private val toInterfaceMap = new TypeMap { - def apply(tp: Type): Type = mapOver( tp match { - case TypeRef(pre, sym, args) if sym.isImplClass => - typeRef(pre, enteringMixin(sym.toInterface), args) - case _ => tp - }) - } - /** The implementation class corresponding to a currently compiled interface. - * todo: try to use Symbol.implClass instead? - */ - private def implClass(iface: Symbol) = iface.implClass orElse (erasure implClass iface) /** Returns the symbol that is accessed by a super-accessor in a mixin composition. * @@ -139,16 +115,16 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { // --------- type transformation ----------------------------------------------- - def isConcreteAccessor(member: Symbol) = - member.hasAccessorFlag && (!member.isDeferred || (member hasFlag lateDEFERRED)) + @inline final def notDeferred(sym: Symbol) = fields.notDeferredOrSynthImpl(sym) /** Is member overridden (either directly or via a bridge) in base class sequence `bcs`? */ def isOverriddenAccessor(member: Symbol, bcs: List[Symbol]): Boolean = beforeOwnPhase { def hasOverridingAccessor(clazz: Symbol) = { clazz.info.nonPrivateDecl(member.name).alternatives.exists( sym => - isConcreteAccessor(sym) && + sym.hasFlag(ACCESSOR) && !sym.hasFlag(MIXEDIN) && + notDeferred(sym) && matchesType(sym.tpe, member.tpe, alwaysMatchSimple = true)) } ( bcs.head != member.owner @@ -156,11 +132,16 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { ) } + /** Add given member to given class, and mark member as mixed-in. */ def addMember(clazz: Symbol, member: Symbol): Symbol = { - debuglog("new member of " + clazz + ":" + member.defString) - clazz.info.decls enter member setFlag MIXEDIN + debuglog(s"mixing into $clazz: ${member.defString}") + // This attachment is used to instruct the backend about which methods in traits require + // a static trait impl method. We remove this from the new symbol created for the method + // mixed into the subclass. + member.removeAttachment[NeedStaticImpl.type] + clazz.info.decls enter member setFlag MIXEDIN resetFlag JAVA_DEFAULTMETHOD } def cloneAndAddMember(mixinClass: Symbol, mixinMember: Symbol, clazz: Symbol): Symbol = addMember(clazz, cloneBeforeErasure(mixinClass, mixinMember, clazz)) @@ -191,57 +172,20 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { newSym } - /** Add getters and setters for all non-module fields of an implementation - * class to its interface unless they are already present. This is done - * only once per class. The mixedin flag is used to remember whether late - * members have been added to an interface. - * - lazy fields don't get a setter. - */ - def addLateInterfaceMembers(clazz: Symbol) { + def publicizeTraitMethods(clazz: Symbol) { if (treatedClassInfos(clazz) != clazz.info) { treatedClassInfos(clazz) = clazz.info assert(phase == currentRun.mixinPhase, phase) - /* Create a new getter. Getters are never private or local. They are - * always accessors and deferred. */ - def newGetter(field: Symbol): Symbol = { - // println("creating new getter for "+ field +" : "+ field.info +" at "+ field.locationString+(field hasFlag MUTABLE)) - val newFlags = field.flags & ~PrivateLocal | ACCESSOR | lateDEFERRED | ( if (field.isMutable) 0 else STABLE ) - // TODO preserve pre-erasure info? - clazz.newMethod(field.getterName, field.pos, newFlags) setInfo MethodType(Nil, field.info) - } - - /* Create a new setter. Setters are never private or local. They are - * always accessors and deferred. */ - def newSetter(field: Symbol): Symbol = { - //println("creating new setter for "+field+field.locationString+(field hasFlag MUTABLE)) - val setterName = field.setterName - val newFlags = field.flags & ~PrivateLocal | ACCESSOR | lateDEFERRED - val setter = clazz.newMethod(setterName, field.pos, newFlags) - // TODO preserve pre-erasure info? - setter setInfo MethodType(setter.newSyntheticValueParams(List(field.info)), UnitTpe) - if (field.needsExpandedSetterName) - setter.name = nme.expandedSetterName(setter.name, clazz) - - setter - } - - clazz.info // make sure info is up to date, so that implClass is set. - val impl = implClass(clazz) orElse abort("No impl class for " + clazz) - - for (member <- impl.info.decls) { - if (!member.isMethod && !member.isModule && !member.isModuleVar) { + for (member <- clazz.info.decls) { + if (member.isMethod) publicizeTraitMethod(member) + else { assert(member.isTerm && !member.isDeferred, member) - if (member.getterIn(impl).isPrivate) { - member.makeNotPrivate(clazz) // this will also make getter&setter not private - } - val getter = member.getterIn(clazz) - if (getter == NoSymbol) addMember(clazz, newGetter(member)) - if (!member.tpe.isInstanceOf[ConstantType] && !member.isLazy) { - val setter = member.setterIn(clazz) - if (setter == NoSymbol) addMember(clazz, newSetter(member)) - } + // disable assert to support compiling against code compiled by an older compiler (until we re-starr) + // assert(member hasFlag PRESUPER, s"unexpected $member in $clazz ${member.debugFlagString}") + clazz.info.decls.unlink(member) } + } debuglog("new defs of " + clazz + " = " + clazz.info.decls) } @@ -262,75 +206,83 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { def cloneAndAddMixinMember(mixinClass: Symbol, mixinMember: Symbol): Symbol = ( cloneAndAddMember(mixinClass, mixinMember, clazz) setPos clazz.pos - resetFlag DEFERRED | lateDEFERRED + resetFlag DEFERRED ) /* Mix in members of implementation class mixinClass into class clazz */ - def mixinImplClassMembers(mixinClass: Symbol, mixinInterface: Symbol) { - if (!mixinClass.isImplClass) devWarning ("Impl class flag is not set " + - ((mixinClass.debugLocationString, mixinInterface.debugLocationString))) - - for (member <- mixinClass.info.decls ; if isForwarded(member)) { - val imember = member overriddenSymbol mixinInterface - imember overridingSymbol clazz match { + def mixinTraitForwarders(mixinClass: Symbol) { + for (member <- mixinClass.info.decls ; if isImplementedStatically(member)) { + member overridingSymbol clazz match { case NoSymbol => - if (clazz.info.findMember(member.name, 0, lateDEFERRED, stableOnly = false).alternatives contains imember) - cloneAndAddMixinMember(mixinInterface, imember).asInstanceOf[TermSymbol] setAlias member + val isMemberOfClazz = clazz.info.findMember(member.name, 0, 0L, stableOnly = false).alternatives.contains(member) + if (isMemberOfClazz) { + def genForwarder(required: Boolean): Unit = { + val owner = member.owner + if (owner.isJavaDefined && owner.isInterface && !clazz.parentSymbols.contains(owner)) { + if (required) { + val text = s"Unable to implement a mixin forwarder for $member in $clazz unless interface ${owner.name} is directly extended by $clazz." + reporter.error(clazz.pos, text) + } + } else + cloneAndAddMixinMember(mixinClass, member).asInstanceOf[TermSymbol] setAlias member + } + + // `member` is a concrete method defined in `mixinClass`, which is a base class of + // `clazz`, and the method is not overridden in `clazz`. A forwarder is needed if: + // + // - A non-trait base class of `clazz` defines a matching method. Example: + // class C {def f: Int}; trait T extends C {def f = 1}; class D extends T + // Even if C.f is abstract, the forwarder in D is needed, otherwise the JVM would + // resolve `D.f` to `C.f`, see jvms-6.5.invokevirtual. + // + // - There exists another concrete, matching method in a parent interface `p` of + // `clazz`, and the `mixinClass` does not itself extend `p`. In this case the + // forwarder is needed to disambiguate. Example: + // trait T1 {def f = 1}; trait T2 extends T1 {override def f = 2}; class C extends T2 + // In C we don't need a forwarder for f because T2 extends T1, so the JVM resolves + // C.f to T2.f non-ambiguously. See jvms-5.4.3.3, "maximally-specific method". + // trait U1 {def f = 1}; trait U2 {self:U1 => override def f = 2}; class D extends U2 + // In D the forwarder is needed, the interfaces U1 and U2 are unrelated at the JVM + // level. + + @tailrec + def existsCompetingMethod(baseClasses: List[Symbol]): Boolean = baseClasses match { + case baseClass :: rest => + if (baseClass ne mixinClass) { + val m = member.overriddenSymbol(baseClass) + val isCompeting = m.exists && { + !m.owner.isTraitOrInterface || + (!m.isDeferred && !mixinClass.isNonBottomSubClass(m.owner)) + } + isCompeting || existsCompetingMethod(rest) + } else existsCompetingMethod(rest) + + case _ => false + } + + def generateJUnitForwarder: Boolean = { + settings.mixinForwarderChoices.isAtLeastJunit && + member.annotations.nonEmpty && + JUnitAnnotations.exists(annot => annot.exists && member.hasAnnotation(annot)) + } + + if (existsCompetingMethod(clazz.baseClasses) || generateJUnitForwarder) + genForwarder(required = true) + else if (settings.mixinForwarderChoices.isTruthy) + genForwarder(required = false) + } + case _ => } } } - /* Mix in members of trait mixinClass into class clazz. Also, - * for each lazy field in mixinClass, add a link from its mixed in member to its - * initializer method inside the implclass. + /* Mix in members of trait mixinClass into class clazz. */ def mixinTraitMembers(mixinClass: Symbol) { // For all members of a trait's interface do: for (mixinMember <- mixinClass.info.decls) { - if (isConcreteAccessor(mixinMember)) { - if (isOverriddenAccessor(mixinMember, clazz.info.baseClasses)) - devWarning(s"Overridden concrete accessor: ${mixinMember.fullLocationString}") - else { - // mixin field accessors - val mixedInAccessor = cloneAndAddMixinMember(mixinClass, mixinMember) - if (mixinMember.isLazy) { - initializer(mixedInAccessor) = ( - implClass(mixinClass).info.decl(mixinMember.name) - orElse abort("Could not find initializer for " + mixinMember.name) - ) - } - if (!mixinMember.isSetter) - mixinMember.tpe match { - case MethodType(Nil, ConstantType(_)) => - // mixinMember is a constant; only getter is needed - ; - case MethodType(Nil, TypeRef(_, UnitClass, _)) => - // mixinMember is a value of type unit. No field needed - ; - case _ => // otherwise mixin a field as well - // enteringPhase: the private field is moved to the implementation class by erasure, - // so it can no longer be found in the mixinMember's owner (the trait) - val accessed = enteringPickler(mixinMember.accessed) - // #3857, need to retain info before erasure when cloning (since cloning only - // carries over the current entry in the type history) - val sym = enteringErasure { - // so we have a type history entry before erasure - clazz.newValue(mixinMember.localName, mixinMember.pos).setInfo(mixinMember.tpe.resultType) - } - sym updateInfo mixinMember.tpe.resultType // info at current phase - - val newFlags = ( - ( PrivateLocal ) - | ( mixinMember getFlag MUTABLE | LAZY) - | ( if (mixinMember.hasStableFlag) 0 else MUTABLE ) - ) - - addMember(clazz, sym setFlag newFlags setAnnotations accessed.annotations) - } - } - } - else if (mixinMember.isSuperAccessor) { // mixin super accessors + if (mixinMember.hasFlag(SUPERACCESSOR)) { // mixin super accessors val superAccessor = addMember(clazz, mixinMember.cloneSymbol(clazz)) setPos clazz.pos assert(superAccessor.alias != NoSymbol, superAccessor) @@ -339,12 +291,42 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { reporter.error(clazz.pos, "Member %s of mixin %s is missing a concrete super implementation.".format( mixinMember.alias, mixinClass)) case alias1 => + if (alias1.owner.isJavaDefined && alias1.owner.isInterface && !clazz.parentSymbols.contains(alias1.owner)) { + val suggestedParent = exitingTyper(clazz.info.baseType(alias1.owner)) + reporter.error(clazz.pos, s"Unable to implement a super accessor required by trait ${mixinClass.name} unless $suggestedParent is directly extended by $clazz.") + } superAccessor.asInstanceOf[TermSymbol] setAlias alias1 } } - else if (mixinMember.isMethod && mixinMember.isModule && mixinMember.hasNoFlags(LIFTED | BRIDGE)) { - // mixin objects: todo what happens with abstract objects? - addMember(clazz, mixinMember.cloneSymbol(clazz, mixinMember.flags & ~(DEFERRED | lateDEFERRED)) setPos clazz.pos) + else if (mixinMember.hasFlag(ACCESSOR) && notDeferred(mixinMember) + && (mixinMember hasFlag PARAMACCESSOR) + && !isOverriddenAccessor(mixinMember, clazz.info.baseClasses)) { + // mixin accessor for constructor parameter + // (note that a paramaccessor cannot have a constant type as it must have a user-defined type) + cloneAndAddMixinMember(mixinClass, mixinMember) + + val name = mixinMember.name + + if (!nme.isSetterName(name)) { + // enteringPhase: the private field is moved to the implementation class by erasure, + // so it can no longer be found in the mixinMember's owner (the trait) + val accessed = enteringPickler(mixinMember.accessed) + // #3857, need to retain info before erasure when cloning (since cloning only + // carries over the current entry in the type history) + val sym = enteringErasure { + // so we have a type history entry before erasure + clazz.newValue(mixinMember.localName, mixinMember.pos).setInfo(mixinMember.tpe.resultType) + } + sym updateInfo mixinMember.tpe.resultType // info at current phase + + val newFlags = ( + (PrivateLocal) + | (mixinMember getFlag MUTABLE) + | (if (mixinMember.hasStableFlag) 0 else MUTABLE) + ) + + addMember(clazz, sym setFlag newFlags setAnnotations accessed.annotations) + } } } } @@ -358,162 +340,38 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { // first complete the superclass with mixed in members addMixedinMembers(clazz.superClass, unit) - for (mc <- clazz.mixinClasses ; if mc hasFlag lateINTERFACE) { + for (mc <- clazz.mixinClasses ; if mc.isTrait) { // @SEAN: adding trait tracking so we don't have to recompile transitive closures unit.depends += mc - addLateInterfaceMembers(mc) + publicizeTraitMethods(mc) mixinTraitMembers(mc) - mixinImplClassMembers(implClass(mc), mc) + mixinTraitForwarders(mc) } } - /** The info transform for this phase does the following: - * - The parents of every class are mapped from implementation class to interface - * - Implementation classes become modules that inherit nothing - * and that define all. - */ - override def transformInfo(sym: Symbol, tp: Type): Type = tp match { - case ClassInfoType(parents, decls, clazz) => - var parents1 = parents - var decls1 = decls - if (!clazz.isPackageClass) { - exitingMixin(clazz.owner.info) - if (clazz.isImplClass) { - clazz setFlag lateMODULE - var sourceModule = clazz.owner.info.decls.lookup(sym.name.toTermName) - if (sourceModule == NoSymbol) { - sourceModule = ( - clazz.owner.newModuleSymbol(sym.name.toTermName, sym.pos, MODULE) - setModuleClass sym.asInstanceOf[ClassSymbol] - ) - clazz.owner.info.decls enter sourceModule - } - else { - sourceModule setPos sym.pos - if (sourceModule.flags != MODULE) { - log(s"!!! Directly setting sourceModule flags for $sourceModule from ${sourceModule.flagString} to MODULE") - sourceModule.flags = MODULE - } - } - sourceModule setInfo sym.tpe - // Companion module isn't visible for anonymous class at this point anyway - assert(clazz.sourceModule != NoSymbol || clazz.isAnonymousClass, s"$clazz has no sourceModule: $sym ${sym.tpe}") - parents1 = List() - decls1 = newScopeWith(decls.toList filter isImplementedStatically: _*) - } else if (!parents.isEmpty) { - parents1 = parents.head :: (parents.tail map toInterface) - } - } - //decls1 = enteringPhase(phase.next)(newScopeWith(decls1.toList: _*))//debug - if ((parents1 eq parents) && (decls1 eq decls)) tp - else ClassInfoType(parents1, decls1, clazz) - - case MethodType(params, restp) => - toInterfaceMap( - if (isImplementedStatically(sym)) { - val ownerParam = sym.newSyntheticValueParam(toInterface(sym.owner.typeOfThis)) - MethodType(ownerParam :: params, restp) - } else - tp) - - case _ => - tp - } - - /** Return a map of single-use fields to the lazy value that uses them during initialization. - * Each field has to be private and defined in the enclosing class, and there must - * be exactly one lazy value using it. - * - * Such fields will be nulled after the initializer has memoized the lazy value. - */ - def singleUseFields(templ: Template): scala.collection.Map[Symbol, List[Symbol]] = { - val usedIn = mutable.HashMap[Symbol, List[Symbol]]() withDefaultValue Nil - - object SingleUseTraverser extends Traverser { - override def traverse(tree: Tree) { - tree match { - case Assign(lhs, rhs) => traverse(rhs) // assignments don't count - case _ => - if (tree.hasSymbolField && tree.symbol != NoSymbol) { - val sym = tree.symbol - if ((sym.hasAccessorFlag || (sym.isTerm && !sym.isMethod)) - && sym.isPrivate - && !(currentOwner.isGetter && currentOwner.accessed == sym) // getter - && !definitions.isPrimitiveValueClass(sym.tpe.resultType.typeSymbol) - && sym.owner == templ.symbol.owner - && !sym.isLazy - && !tree.isDef) { - debuglog("added use in: " + currentOwner + " -- " + tree) - usedIn(sym) ::= currentOwner - - } - } - super.traverse(tree) - } - } - } - SingleUseTraverser(templ) - debuglog("usedIn: " + usedIn) - usedIn filter { - case (_, member :: Nil) => member.isValue && member.isLazy - case _ => false - } - } + override def transformInfo(sym: Symbol, tp: Type): Type = tp // --------- term transformation ----------------------------------------------- protected def newTransformer(unit: CompilationUnit): Transformer = new MixinTransformer(unit) - class MixinTransformer(unit : CompilationUnit) extends Transformer { - /** Within a static implementation method: the parameter referring to the - * current object. Undefined everywhere else. - */ - private var self: Symbol = _ + class MixinTransformer(unit : CompilationUnit) extends Transformer with AccessorTreeSynthesis { + /** The typer */ + private var localTyper: erasure.Typer = _ + protected def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) /** The rootContext used for typing */ private val rootContext = erasure.NoContext.make(EmptyTree, rootMirror.RootClass, newScope) - /** The typer */ - private var localTyper: erasure.Typer = _ - private def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) - - /** Map lazy values to the fields they should null after initialization. */ - private var lazyValNullables: Map[Symbol, Set[Symbol]] = _ - - /** Map a field symbol to a unique integer denoting its position in the class layout. - * For each class, fields defined by the class come after inherited fields. Mixed-in - * fields count as fields defined by the class itself. - */ - private val fieldOffset = perRunCaches.newMap[Symbol, Int]() - - private val bitmapKindForCategory = perRunCaches.newMap[Name, ClassSymbol]() - - // ByteClass, IntClass, LongClass - private def bitmapKind(field: Symbol): ClassSymbol = bitmapKindForCategory(bitmapCategory(field)) - - private def flagsPerBitmap(field: Symbol): Int = bitmapKind(field) match { - case BooleanClass => 1 - case ByteClass => 8 - case IntClass => 32 - case LongClass => 64 - } - + private val nullables = mutable.AnyRefMap[Symbol, Map[Symbol, List[Symbol]]]() /** The first transform; called in a pre-order traversal at phase mixin * (that is, every node is processed before its children). * What transform does: * - For every non-trait class, add all mixed in members to the class info. - * - For every trait, add all late interface members to the class info - * - For every static implementation method: - * - remove override flag - * - create a new method definition that also has a `self` parameter - * (which comes first) Iuli: this position is assumed by tail call elimination - * on a different receiver. Storing a new 'this' assumes it is located at - * index 0 in the local variable table. See 'STORE_THIS' and GenASM. - * - Map implementation class types in type-apply's to their interfaces - * - Remove all fields in implementation classes + * - For every non-trait class, assign null to singly used private fields after use in lazy initialization. */ private def preTransform(tree: Tree): Tree = { val sym = tree.symbol @@ -524,617 +382,160 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { if (!currentOwner.isTrait && !isPrimitiveValueClass(currentOwner)) addMixedinMembers(currentOwner, unit) - else if (currentOwner hasFlag lateINTERFACE) - addLateInterfaceMembers(currentOwner) + else if (currentOwner.isTrait) + publicizeTraitMethods(currentOwner) + + if (!currentOwner.isTrait) + nullables(currentOwner) = lazyValNullables(currentOwner, body) tree - case DefDef(_, _, _, vparams :: Nil, _, _) => - if (currentOwner.isImplClass) { - if (isImplementedStatically(sym)) { - sym setFlag notOVERRIDE - self = sym.newValueParameter(nme.SELF, sym.pos) setInfo toInterface(currentOwner.typeOfThis) - val selfdef = ValDef(self) setType NoType - copyDefDef(tree)(vparamss = List(selfdef :: vparams)) - } - else EmptyTree - } + case dd: DefDef if dd.symbol.name.endsWith(nme.LAZY_SLOW_SUFFIX) => + val fieldsToNull = nullables.getOrElse(sym.enclClass, Map()).getOrElse(sym, Nil) + if (fieldsToNull.isEmpty) dd else { - if (currentOwner.isTrait && sym.isSetter && !enteringPickler(sym.isDeferred)) { - sym.addAnnotation(TraitSetterAnnotationClass) + deriveDefDef(dd) { + case blk@Block(stats, expr) => + assert(dd.symbol.originalOwner.isClass, dd.symbol) + def nullify(sym: Symbol) = + Select(gen.mkAttributedThis(sym.enclClass), sym.accessedOrSelf) === NULL + val stats1 = stats ::: fieldsToNull.map(nullify) + treeCopy.Block(blk, stats1, expr) + case tree => + devWarning("Unexpected tree shape in lazy slow path") + tree } - tree - } - // !!! What is this doing, and why is it only looking for exactly - // one type parameter? It would seem to be - // "Map implementation class types in type-apply's to their interfaces" - // from the comment on preTransform, but is there some way we should know - // that impl class types in type applies can only appear in single - // type parameter type constructors? - case Apply(tapp @ TypeApply(fn, List(arg)), List()) => - if (arg.tpe.typeSymbol.isImplClass) { - val ifacetpe = toInterface(arg.tpe) - arg setType ifacetpe - tapp setType MethodType(Nil, ifacetpe) - tree setType ifacetpe } - tree - case ValDef(_, _, _, _) if currentOwner.isImplClass => - EmptyTree - case _ => - tree - } - } - /** Create an identifier which references self parameter. - */ - private def selfRef(pos: Position) = - gen.mkAttributedIdent(self) setPos pos - - /** Replace a super reference by this or the self parameter, depending - * on whether we are in an implementation class or not. - * Leave all other trees unchanged. - */ - private def transformSuper(tree: Tree) = tree match { - case Super(qual, _) => - transformThis(qual) - case _ => - tree - } - - /** Replace a this reference to the current implementation class by the self - * parameter. Leave all other trees unchanged. - */ - private def transformThis(tree: Tree) = tree match { - case This(_) if tree.symbol.isImplClass => - assert(tree.symbol == currentOwner.enclClass) - selfRef(tree.pos) - case _ => - tree - } - - /** Create a static reference to given symbol `sym` of the - * form `M.sym` where M is the symbol's implementation module. - */ - private def staticRef(sym: Symbol): Tree = { - sym.owner.info //todo: needed? - sym.owner.owner.info //todo: needed? - - if (sym.owner.sourceModule eq NoSymbol) - abort(s"Cannot create static reference to $sym because ${sym.safeOwner} has no source module") - else - REF(sym.owner.sourceModule) DOT sym - } - - def needsInitAndHasOffset(sym: Symbol) = - needsInitFlag(sym) && (fieldOffset contains sym) - - /** Examines the symbol and returns a name indicating what brand of - * bitmap it requires. The possibilities are the BITMAP_* vals - * defined in StdNames. If it needs no bitmap, nme.NO_NAME. - */ - def bitmapCategory(field: Symbol): Name = { - import nme._ - val isNormal = ( - if (isFieldWithBitmap(field)) true - // bitmaps for checkinit fields are not inherited - else if (needsInitFlag(field) && !field.isDeferred) false - else return NO_NAME - ) - if (field.accessed hasAnnotation TransientAttr) { - if (isNormal) BITMAP_TRANSIENT - else BITMAP_CHECKINIT_TRANSIENT - } else { - if (isNormal) BITMAP_NORMAL - else BITMAP_CHECKINIT + case _ => tree } } - /** Add all new definitions to a non-trait class - * These fall into the following categories: - * - for a trait interface: - * - abstract accessors for all fields in the implementation class - * - for a non-trait class: - * - A field for every in a mixin class - * - Setters and getters for such fields - * - getters for mixed in lazy fields are completed - * - module variables and module creators for every module in a mixin class - * (except if module is lifted -- in this case the module variable - * is local to some function, and the creator method is static.) - * - A super accessor for every super accessor in a mixin class - * - Forwarders for all methods that are implemented statically - * All superaccessors are completed with right-hand sides (@see completeSuperAccessor) - * @param clazz The class to which definitions are added - */ - private def addNewDefs(clazz: Symbol, stats: List[Tree]): List[Tree] = { - val newDefs = mutable.ListBuffer[Tree]() - - /* Attribute given tree and anchor at given position */ - def attributedDef(pos: Position, tree: Tree): Tree = { - debuglog("add new def to " + clazz + ": " + tree) - typedPos(pos)(tree) - } - - /* The position of given symbol, or, if this is undefined, - * the position of the current class. - */ - def position(sym: Symbol) = - if (sym.pos == NoPosition) clazz.pos else sym.pos - - /* Add tree at given position as new definition */ - def addDef(pos: Position, tree: Tree) { - newDefs += attributedDef(pos, tree) - } - - /* Add new method definition. - * - * @param sym The method symbol. - * @param rhs The method body. - */ - def addDefDef(sym: Symbol, rhs: Tree = EmptyTree) = addDef(position(sym), DefDef(sym, rhs)) - def addValDef(sym: Symbol, rhs: Tree = EmptyTree) = addDef(position(sym), ValDef(sym, rhs)) - - /* Add `newdefs` to `stats`, removing any abstract method definitions - * in `stats` that are matched by some symbol defined in - * `newDefs`. - */ - def add(stats: List[Tree], newDefs: List[Tree]) = { - val newSyms = newDefs map (_.symbol) - def isNotDuplicate(tree: Tree) = tree match { - case DefDef(_, _, _, _, _, _) => - val sym = tree.symbol - !(sym.isDeferred && - (newSyms exists (nsym => nsym.name == sym.name && (nsym.tpe matches sym.tpe)))) - case _ => - true - } - if (newDefs.isEmpty) stats - else newDefs ::: (stats filter isNotDuplicate) - } - - /* If `stat` is a superaccessor, complete it by adding a right-hand side. - * Note: superaccessors are always abstract until this point. - * The method to call in a superaccessor is stored in the accessor symbol's alias field. - * The rhs is: - * super.A(xs) where A is the super accessor's alias and xs are its formal parameters. - * This rhs is typed and then mixin transformed. - */ - def completeSuperAccessor(stat: Tree) = stat match { - case DefDef(_, _, _, vparams :: Nil, _, EmptyTree) if stat.symbol.isSuperAccessor => - val body = atPos(stat.pos)(Apply(Select(Super(clazz, tpnme.EMPTY), stat.symbol.alias), vparams map (v => Ident(v.symbol)))) - val pt = stat.symbol.tpe.resultType - - copyDefDef(stat)(rhs = enteringMixin(transform(localTyper.typed(body, pt)))) - case _ => - stat - } - - /* - * Return the bitmap field for 'offset'. Depending on the hierarchy it is possible to reuse - * the bitmap of its parents. If that does not exist yet we create one. - */ - def bitmapFor(clazz0: Symbol, offset: Int, field: Symbol): Symbol = { - val category = bitmapCategory(field) - val bitmapName = nme.newBitmapName(category, offset / flagsPerBitmap(field)).toTermName - val sym = clazz0.info.decl(bitmapName) - - assert(!sym.isOverloaded, sym) - - def createBitmap: Symbol = { - val bitmapKind = bitmapKindForCategory(category) - val sym = clazz0.newVariable(bitmapName, clazz0.pos) setInfo bitmapKind.tpe - enteringTyper(sym addAnnotation VolatileAttr) - - category match { - case nme.BITMAP_TRANSIENT | nme.BITMAP_CHECKINIT_TRANSIENT => sym addAnnotation TransientAttr - case _ => - } - val init = bitmapKind match { - case BooleanClass => ValDef(sym, FALSE) - case _ => ValDef(sym, ZERO) + /** Map lazy values to the fields they should null after initialization. */ + def lazyValNullables(clazz: Symbol, templStats: List[Tree]): Map[Symbol, List[Symbol]] = { + // if there are no lazy fields, take the fast path and save a traversal of the whole AST + if (!clazz.info.decls.exists(_.isLazy)) Map() + else { + // A map of single-use fields to the lazy value that uses them during initialization. + // Each field has to be private and defined in the enclosing class, and there must + // be exactly one lazy value using it. + // + // Such fields will be nulled after the initializer has memoized the lazy value. + val singleUseFields: Map[Symbol, List[Symbol]] = { + val usedIn = mutable.HashMap[Symbol, List[Symbol]]() withDefaultValue Nil + + object SingleUseTraverser extends Traverser { + override def traverse(tree: Tree) { + tree match { + // assignment targets don't count as a dereference -- only check the rhs + case Assign(_, rhs) => traverse(rhs) + case tree: RefTree if tree.symbol != NoSymbol => + val sym = tree.symbol + // println(s"$sym in ${sym.owner} from $currentOwner ($tree)") + if ((sym.hasAccessorFlag || (sym.isTerm && !sym.isMethod)) && sym.isPrivate && !sym.isLazy && !sym.isModule // non-lazy private field or its accessor + && !definitions.isPrimitiveValueClass(sym.tpe.resultType.typeSymbol) // primitives don't hang on to significant amounts of heap + && sym.owner == currentOwner.enclClass && !(currentOwner.isGetter && currentOwner.accessed == sym)) { + + // println("added use in: " + currentOwner + " -- " + tree) + usedIn(sym) ::= currentOwner + } + super.traverse(tree) + case _ => super.traverse(tree) + } + } } - - sym setFlag PrivateLocal - clazz0.info.decls.enter(sym) - addDef(clazz0.pos, init) - sym + templStats foreach SingleUseTraverser.apply + // println("usedIn: " + usedIn) + + // only consider usages from non-transient lazy vals (SI-9365) + val singlyUsedIn = usedIn.filter { + case (_, member :: Nil) if member.name.endsWith(nme.LAZY_SLOW_SUFFIX) => + val lazyAccessor = member.owner.info.decl(member.name.stripSuffix(nme.LAZY_SLOW_SUFFIX)) + !lazyAccessor.accessedOrSelf.hasAnnotation(TransientAttr) + case _ => false + }.toMap + + // println("singlyUsedIn: " + singlyUsedIn) + singlyUsedIn } - sym orElse createBitmap - } - - def maskForOffset(offset: Int, sym: Symbol, kind: ClassSymbol): Tree = { - def realOffset = offset % flagsPerBitmap(sym) - if (kind == LongClass ) LIT(1L << realOffset) else LIT(1 << realOffset) - } - - /* Return an (untyped) tree of the form 'Clazz.this.bmp = Clazz.this.bmp | mask'. */ - def mkSetFlag(clazz: Symbol, offset: Int, valSym: Symbol, kind: ClassSymbol): Tree = { - val bmp = bitmapFor(clazz, offset, valSym) - def mask = maskForOffset(offset, valSym, kind) - def x = This(clazz) DOT bmp - def newValue = if (kind == BooleanClass) TRUE else (x GEN_| (mask, kind)) - - x === newValue - } - - /* Return an (untyped) tree of the form 'clazz.this.bitmapSym & mask (==|!=) 0', the - * precise comparison operator depending on the value of 'equalToZero'. - */ - def mkTest(clazz: Symbol, mask: Tree, bitmapSym: Symbol, equalToZero: Boolean, kind: ClassSymbol): Tree = { - val bitmapTree = (This(clazz) DOT bitmapSym) - def lhs = bitmapTree GEN_& (mask, kind) - kind match { - case BooleanClass => - if (equalToZero) NOT(bitmapTree) - else bitmapTree - case _ => - if (equalToZero) lhs GEN_== (ZERO, kind) - else lhs GEN_!= (ZERO, kind) - } - } - - def mkSlowPathDef(clazz: Symbol, lzyVal: Symbol, cond: Tree, syncBody: List[Tree], - stats: List[Tree], retVal: Tree, attrThis: Tree, args: List[Tree]): Symbol = { - val defSym = clazz.newMethod(nme.newLazyValSlowComputeName(lzyVal.name.toTermName), lzyVal.pos, PRIVATE) - val params = defSym newSyntheticValueParams args.map(_.symbol.tpe) - defSym setInfoAndEnter MethodType(params, lzyVal.tpe.resultType) - val rhs: Tree = (gen.mkSynchronizedCheck(attrThis, cond, syncBody, stats)).changeOwner(currentOwner -> defSym) - val strictSubst = new TreeSymSubstituterWithCopying(args.map(_.symbol), params) - addDef(position(defSym), DefDef(defSym, strictSubst(BLOCK(rhs, retVal)))) - defSym - } - - def mkFastPathLazyBody(clazz: Symbol, lzyVal: Symbol, cond: Tree, syncBody: List[Tree], - stats: List[Tree], retVal: Tree): Tree = { - mkFastPathBody(clazz, lzyVal, cond, syncBody, stats, retVal, gen.mkAttributedThis(clazz), List()) - } - - def mkFastPathBody(clazz: Symbol, lzyVal: Symbol, cond: Tree, syncBody: List[Tree], - stats: List[Tree], retVal: Tree, attrThis: Tree, args: List[Tree]): Tree = { - val slowPathSym: Symbol = mkSlowPathDef(clazz, lzyVal, cond, syncBody, stats, retVal, attrThis, args) - If(cond, fn (This(clazz), slowPathSym, args.map(arg => Ident(arg.symbol)): _*), retVal) - } - - - /* Always copy the tree if we are going to perform sym substitution, - * otherwise we will side-effect on the tree that is used in the fast path - */ - class TreeSymSubstituterWithCopying(from: List[Symbol], to: List[Symbol]) extends TreeSymSubstituter(from, to) { - override def transform(tree: Tree): Tree = - if (tree.hasSymbolField && from.contains(tree.symbol)) - super.transform(tree.duplicate) - else super.transform(tree.duplicate) - - override def apply[T <: Tree](tree: T): T = if (from.isEmpty) tree else super.apply(tree) - } - - /* return a 'lazified' version of rhs. It uses double-checked locking to ensure - * initialization is performed at most once. For performance reasons the double-checked - * locking is split into two parts, the first (fast) path checks the bitmap without - * synchronizing, and if that fails it initializes the lazy val within the - * synchronization block (slow path). This way the inliner should optimize - * the fast path because the method body is small enough. - * Private fields used only in this initializer are subsequently set to null. - * - * @param clazz The class symbol - * @param lzyVal The symbol of this lazy field - * @param init The tree which initializes the field ( f = <rhs> ) - * @param offset The offset of this field in the flags bitmap - * - * The result will be a tree of the form - * { if ((bitmap&n & MASK) == 0) this.l$compute() - * else l$ - * - * ... - * def l$compute() = { synchronized(this) { - * if ((bitmap$n & MASK) == 0) { - * init // l$ = <rhs> - * bitmap$n = bimap$n | MASK - * }} - * l$ - * } - * - * ... - * this.f1 = null - * ... this.fn = null - * } - * where bitmap$n is a byte, int or long value acting as a bitmap of initialized values. - * The kind of the bitmap determines how many bit indicators for lazy vals are stored in it. - * For Int bitmap it is 32 and then 'n' in the above code is: (offset / 32), - * the MASK is (1 << (offset % 32)). - * If the class contains only a single lazy val then the bitmap is represented - * as a Boolean and the condition checking is a simple bool test. - */ - def mkLazyDef(clazz: Symbol, lzyVal: Symbol, init: List[Tree], retVal: Tree, offset: Int): Tree = { - def nullify(sym: Symbol) = Select(This(clazz), sym.accessedOrSelf) === LIT(null) - - val bitmapSym = bitmapFor(clazz, offset, lzyVal) - val kind = bitmapKind(lzyVal) - val mask = maskForOffset(offset, lzyVal, kind) - def cond = mkTest(clazz, mask, bitmapSym, equalToZero = true, kind) - val nulls = lazyValNullables(lzyVal).toList sortBy (_.id) map nullify - def syncBody = init ::: List(mkSetFlag(clazz, offset, lzyVal, kind), UNIT) - - if (nulls.nonEmpty) - log("nulling fields inside " + lzyVal + ": " + nulls) - - typedPos(init.head.pos)(mkFastPathLazyBody(clazz, lzyVal, cond, syncBody, nulls, retVal)) - } - - def mkInnerClassAccessorDoubleChecked(attrThis: Tree, rhs: Tree, moduleSym: Symbol, args: List[Tree]): Tree = - rhs match { - case Block(List(assign), returnTree) => - val Assign(moduleVarRef, _) = assign - val cond = Apply(Select(moduleVarRef, Object_eq), List(NULL)) - mkFastPathBody(clazz, moduleSym, cond, List(assign), List(NULL), returnTree, attrThis, args) - case _ => - abort(s"Invalid getter $rhs for module in $clazz") - } + val map = mutable.Map[Symbol, Set[Symbol]]() withDefaultValue Set() + // invert the map to see which fields can be nulled for each non-transient lazy val + for ((field, users) <- singleUseFields; lazyFld <- users) map(lazyFld) += field - def mkCheckedAccessor(clazz: Symbol, retVal: Tree, offset: Int, pos: Position, fieldSym: Symbol): Tree = { - val sym = fieldSym.getterIn(fieldSym.owner) - val bitmapSym = bitmapFor(clazz, offset, sym) - val kind = bitmapKind(sym) - val mask = maskForOffset(offset, sym, kind) - val msg = s"Uninitialized field: ${unit.source}: ${pos.line}" - val result = - IF (mkTest(clazz, mask, bitmapSym, equalToZero = false, kind)) . - THEN (retVal) . - ELSE (Throw(NewFromConstructor(UninitializedFieldConstructor, LIT(msg)))) - - typedPos(pos)(BLOCK(result, retVal)) + map.mapValues(_.toList sortBy (_.id)).toMap } + } - /* Complete lazy field accessors. Applies only to classes, - * for its own (non inherited) lazy fields. If 'checkinit' - * is enabled, getters that check for the initialized bit are - * generated, and the class constructor is changed to set the - * initialized bits. - */ - def addCheckedGetters(clazz: Symbol, stats: List[Tree]): List[Tree] = { - def dd(stat: DefDef) = { - val sym = stat.symbol - def isUnit = sym.tpe.resultType.typeSymbol == UnitClass - def isEmpty = stat.rhs == EmptyTree - - if (sym.isLazy && !isEmpty && !clazz.isImplClass) { - assert(fieldOffset contains sym, sym) - deriveDefDef(stat) { - case t if isUnit => mkLazyDef(clazz, sym, List(t), UNIT, fieldOffset(sym)) - - case Block(stats, res) => - mkLazyDef(clazz, sym, stats, Select(This(clazz), res.symbol), fieldOffset(sym)) - - case t => t // pass specialized lazy vals through - } - } - else if (needsInitFlag(sym) && !isEmpty && !clazz.hasFlag(IMPLCLASS | TRAIT)) { - assert(fieldOffset contains sym, sym) - deriveDefDef(stat)(rhs => - (mkCheckedAccessor(clazz, _: Tree, fieldOffset(sym), stat.pos, sym))( - if (sym.tpe.resultType.typeSymbol == UnitClass) UNIT - else rhs - ) - ) - } - else if (sym.isConstructor) { - deriveDefDef(stat)(addInitBits(clazz, _)) - } - else if (settings.checkInit && !clazz.isTrait && sym.isSetter) { - val getter = sym.getterIn(clazz) - if (needsInitFlag(getter) && fieldOffset.isDefinedAt(getter)) - deriveDefDef(stat)(rhs => Block(List(rhs, localTyper.typed(mkSetFlag(clazz, fieldOffset(getter), getter, bitmapKind(getter)))), UNIT)) - else stat - } - else if (sym.isModule && (!clazz.isTrait || clazz.isImplClass) && !sym.isBridge) { - deriveDefDef(stat)(rhs => - typedPos(stat.pos)( - mkInnerClassAccessorDoubleChecked( - // Martin to Hubert: I think this can be replaced by selfRef(tree.pos) - // @PP: It does not seem so, it crashes for me trying to bootstrap. - if (clazz.isImplClass) gen.mkAttributedIdent(stat.vparamss.head.head.symbol) else gen.mkAttributedThis(clazz), - rhs, sym, stat.vparamss.head - ) - ) - ) - } - else stat - } - stats map { - case defn: DefDef => dd(defn) - case stat => stat - } - } + /** Add all new definitions to a non-trait class + * + * These fall into the following categories: + * - for a trait interface: + * - abstract accessors for all paramaccessor or early initialized fields + * - for a non-trait class: + * - field and accessor implementations for each inherited paramaccessor or early initialized field + * - A super accessor for every super accessor in a mixin class + * - Forwarders for all methods that are implemented statically + * + * All superaccessors are completed with right-hand sides (@see completeSuperAccessor) + * + * @param clazz The class to which definitions are added + */ + private def addNewDefs(clazz: Symbol, stats: List[Tree]): List[Tree] = { + val accessorSynth = new UncheckedAccessorSynth(clazz) + import accessorSynth._ - class AddInitBitsTransformer(clazz: Symbol) extends Transformer { - private def checkedGetter(lhs: Tree) = { - val sym = clazz.info decl lhs.symbol.getterName suchThat (_.isGetter) - if (needsInitAndHasOffset(sym)) { - debuglog("adding checked getter for: " + sym + " " + lhs.symbol.flagString) - List(localTyper typed mkSetFlag(clazz, fieldOffset(sym), sym, bitmapKind(sym))) - } - else Nil + // for all symbols `sym` in the class definition, which are mixed in by mixinTraitMembers + for (sym <- clazz.info.decls ; if sym hasFlag MIXEDIN) { + // if current class is a trait, add an abstract method for accessor `sym` + // ditto for a super accessor (will get an RHS in completeSuperAccessor) + if (clazz.isTrait || sym.isSuperAccessor) addDefDef(sym) + // implement methods mixed in from a supertrait (the symbols were created by mixinTraitMembers) + else if (sym.hasFlag(ACCESSOR) && !sym.hasFlag(DEFERRED)) { + assert(sym hasFlag (PARAMACCESSOR), s"mixed in $sym from $clazz is not param?!?") + + // add accessor definitions + addDefDef(sym, accessorBody(sym)) } - override def transformStats(stats: List[Tree], exprOwner: Symbol) = { - // !!! Ident(self) is never referenced, is it supposed to be confirming - // that self is anything in particular? - super.transformStats( - stats flatMap { - case stat @ Assign(lhs @ Select(This(_), _), rhs) => stat :: checkedGetter(lhs) - // remove initialization for default values - case Apply(lhs @ Select(Ident(self), _), EmptyTree.asList) if lhs.symbol.isSetter => Nil - case stat => List(stat) - }, - exprOwner - ) + else if (!sym.isMethod) addValDef(sym) // field + else if (!sym.isMacro) { // forwarder + assert(sym.alias != NoSymbol, (sym, sym.debugFlagString, clazz)) + // debuglog("New forwarder: " + sym.defString + " => " + sym.alias.defString) + addDefDef(sym, Apply(SuperSelect(clazz, sym.alias), sym.paramss.head.map(Ident(_)))) } } - /* Adds statements to set the 'init' bit for each field initialized - * in the body of a constructor. - */ - def addInitBits(clazz: Symbol, rhs: Tree): Tree = - new AddInitBitsTransformer(clazz) transform rhs - - // begin addNewDefs - - /* Fill the map from fields to offset numbers. - * Instead of field symbols, the map keeps their getter symbols. This makes - * code generation easier later. - */ - def buildBitmapOffsets() { - def fold(fields: List[Symbol], category: Name) = { - var idx = 0 - fields foreach { f => - fieldOffset(f) = idx - idx += 1 - } + val implementedAccessors = implementWithNewDefs(stats) - if (idx == 0) () - else if (idx == 1) bitmapKindForCategory(category) = BooleanClass - else if (idx < 9) bitmapKindForCategory(category) = ByteClass - else if (idx < 33) bitmapKindForCategory(category) = IntClass - else bitmapKindForCategory(category) = LongClass - } - clazz.info.decls.toList groupBy bitmapCategory foreach { - case (nme.NO_NAME, _) => () - case (category, fields) => fold(fields, category) + if (clazz.isTrait) + implementedAccessors filter { + case vd: ValDef => assert(vd.symbol.hasFlag(PRESUPER | PARAMACCESSOR), s"unexpected valdef $vd in trait $clazz"); false + case _ => true } - } - buildBitmapOffsets() - var stats1 = addCheckedGetters(clazz, stats) - - def getterBody(getter: Symbol) = { - assert(getter.isGetter) - val readValue = getter.tpe match { - // A field "final val f = const" in a trait generates a getter with a ConstantType. - case MethodType(Nil, ConstantType(c)) => - Literal(c) + else { + /* If `stat` is a superaccessor, complete it by adding a right-hand side. + * Note: superaccessors are always abstract until this point. + * The method to call in a superaccessor is stored in the accessor symbol's alias field. + * The rhs is: + * super.A(xs) where A is the super accessor's alias and xs are its formal parameters. + * This rhs is typed and then mixin transformed. + */ + def completeSuperAccessor(stat: Tree) = stat match { + case DefDef(_, _, _, vparams :: Nil, _, EmptyTree) if stat.symbol.isSuperAccessor => + val body = atPos(stat.pos)(Apply(SuperSelect(clazz, stat.symbol.alias), vparams map (v => Ident(v.symbol)))) + val pt = stat.symbol.tpe.resultType + + copyDefDef(stat)(rhs = enteringMixin(transform(localTyper.typed(body, pt)))) case _ => - // if it is a mixed-in lazy value, complete the accessor - if (getter.isLazy) { - val isUnit = isUnitGetter(getter) - val initCall = Apply(staticRef(initializer(getter)), gen.mkAttributedThis(clazz) :: Nil) - val selection = fieldAccess(getter) - val init = if (isUnit) initCall else atPos(getter.pos)(Assign(selection, initCall)) - val returns = if (isUnit) UNIT else selection - mkLazyDef(clazz, getter, List(init), returns, fieldOffset(getter)) - } - // For a field of type Unit in a trait, no actual field is generated when being mixed in. - else if (isUnitGetter(getter)) UNIT - else fieldAccess(getter) + stat } - if (!needsInitFlag(getter)) readValue - else mkCheckedAccessor(clazz, readValue, fieldOffset(getter), getter.pos, getter) - } - def setterBody(setter: Symbol) = { - val getter = setter.getterIn(clazz) - - // A trait with a field of type Unit creates a trait setter (invoked by the - // implementation class constructor), like for any other trait field. - // However, no actual field is created in the class that mixes in the trait. - // Therefore the setter does nothing (except setting the -Xcheckinit flag). - - val setInitFlag = - if (!needsInitFlag(getter)) Nil - else List(mkSetFlag(clazz, fieldOffset(getter), getter, bitmapKind(getter))) - - val fieldInitializer = - if (isUnitGetter(getter)) Nil - else List(Assign(fieldAccess(setter), Ident(setter.firstParam))) - - (fieldInitializer ::: setInitFlag) match { - case Nil => UNIT - // If there's only one statement, the Block factory does not actually create a Block. - case stats => Block(stats: _*) - } + implementedAccessors map completeSuperAccessor } - - def isUnitGetter(getter: Symbol) = getter.tpe.resultType.typeSymbol == UnitClass - def fieldAccess(accessor: Symbol) = Select(This(clazz), accessor.accessed) - - def isOverriddenSetter(sym: Symbol) = - nme.isTraitSetterName(sym.name) && { - val other = sym.nextOverriddenSymbol - isOverriddenAccessor(other.getterIn(other.owner), clazz.info.baseClasses) - } - - // for all symbols `sym` in the class definition, which are mixed in: - for (sym <- clazz.info.decls ; if sym hasFlag MIXEDIN) { - // if current class is a trait interface, add an abstract method for accessor `sym` - if (clazz hasFlag lateINTERFACE) { - addDefDef(sym) - } - // if class is not a trait add accessor definitions - else if (!clazz.isTrait) { - if (isConcreteAccessor(sym)) { - // add accessor definitions - addDefDef(sym, { - if (sym.isSetter) { - // If this is a setter of a mixed-in field which is overridden by another mixin, - // the trait setter of the overridden one does not need to do anything - the - // trait setter of the overriding field will initialize the field. - if (isOverriddenSetter(sym)) UNIT - else setterBody(sym) - } - else getterBody(sym) - }) - } - else if (sym.isModule && !(sym hasFlag LIFTED | BRIDGE)) { - // add modules - val vsym = sym.owner.newModuleVarSymbol(sym) - addDef(position(sym), ValDef(vsym)) - - // !!! TODO - unravel the enormous duplication between this code and - // eliminateModuleDefs in RefChecks. - val rhs = gen.newModule(sym, vsym.tpe) - val assignAndRet = gen.mkAssignAndReturn(vsym, rhs) - val attrThis = gen.mkAttributedThis(clazz) - val rhs1 = mkInnerClassAccessorDoubleChecked(attrThis, assignAndRet, sym, List()) - - addDefDef(sym, rhs1) - } - else if (!sym.isMethod) { - // add fields - addValDef(sym) - } - else if (sym.isSuperAccessor) { - // add superaccessors - addDefDef(sym) - } - else { - // add forwarders - assert(sym.alias != NoSymbol, sym) - // debuglog("New forwarder: " + sym.defString + " => " + sym.alias.defString) - if (!sym.isMacro) addDefDef(sym, Apply(staticRef(sym.alias), gen.mkAttributedThis(clazz) :: sym.paramss.head.map(Ident))) - } - } - } - stats1 = add(stats1, newDefs.toList) - if (!clazz.isTrait) stats1 = stats1 map completeSuperAccessor - stats1 - } - - private def nullableFields(templ: Template): Map[Symbol, Set[Symbol]] = { - val scope = templ.symbol.owner.info.decls - // if there are no lazy fields, take the fast path and save a traversal of the whole AST - if (scope exists (_.isLazy)) { - val map = mutable.Map[Symbol, Set[Symbol]]() withDefaultValue Set() - // check what fields can be nulled for - for ((field, users) <- singleUseFields(templ); lazyFld <- users if !lazyFld.accessed.hasAnnotation(TransientAttr)) - map(lazyFld) += field - - map.toMap - } - else Map() } /** The transform that gets applied to a tree after it has been completely * traversed and possible modified by a preTransform. * This step will - * - change every node type that refers to an implementation class to its - * corresponding interface, unless the node's symbol is an implementation class. * - change parents of templates to conform to parents in the symbol info * - add all new definitions to a class or interface * - remove widening casts @@ -1142,105 +543,37 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { * to static calls of methods in implementation modules (@see staticCall) * - change super calls to methods in implementation classes to static calls * (@see staticCall) - * - change `this` in implementation modules to references to the self parameter - * - refer to fields in some implementation class via an abstract method in the interface. */ private def postTransform(tree: Tree): Tree = { - def siteWithinImplClass = currentOwner.enclClass.isImplClass val sym = tree.symbol - // change every node type that refers to an implementation class to its - // corresponding interface, unless the node's symbol is an implementation class. - if (tree.tpe.typeSymbol.isImplClass && ((sym eq null) || !sym.isImplClass)) - tree modifyType toInterface - tree match { case templ @ Template(parents, self, body) => // change parents of templates to conform to parents in the symbol info val parents1 = currentOwner.info.parents map (t => TypeTree(t) setPos tree.pos) - // mark fields which can be nulled afterward - lazyValNullables = nullableFields(templ) withDefaultValue Set() - // add all new definitions to current class or interface - treeCopy.Template(tree, parents1, self, addNewDefs(currentOwner, body)) - - // remove widening casts - case Apply(TypeApply(Select(qual, _), targ :: _), _) if isCastSymbol(sym) && (qual.tpe <:< targ.tpe) => - qual - - case Apply(Select(qual, _), args) => - /* Changes `qual.m(args)` where m refers to an implementation - * class method to Q.m(S, args) where Q is the implementation module of - * `m` and S is the self parameter for the call, which - * is determined as follows: - * - if qual != super, qual itself - * - if qual == super, and we are in an implementation class, - * the current self parameter. - * - if qual == super, and we are not in an implementation class, `this` - */ - def staticCall(target: Symbol) = { - def implSym = implClass(sym.owner).info.member(sym.name) - assert(target ne NoSymbol, - List(sym + ":", sym.tpe, sym.owner, implClass(sym.owner), implSym, - enteringPrevPhase(implSym.tpe), phase) mkString " " - ) - typedPos(tree.pos)(Apply(staticRef(target), transformSuper(qual) :: args)) - } - - if (isStaticOnly(sym)) { - // change calls to methods which are defined only in implementation - // classes to static calls of methods in implementation modules - staticCall(sym) - } - else qual match { - case Super(_, mix) => - // change super calls to methods in implementation classes to static calls. - // Transform references super.m(args) as follows: - // - if `m` refers to a trait, insert a static call to the corresponding static - // implementation - // - otherwise return tree unchanged - assert( - !(mix == tpnme.EMPTY && siteWithinImplClass), - "illegal super in trait: " + currentOwner.enclClass + " " + tree - ) - if (sym.owner hasFlag lateINTERFACE) { - if (sym.hasAccessorFlag) { - assert(args.isEmpty, args) - val sym1 = sym.overridingSymbol(currentOwner.enclClass) - typedPos(tree.pos)((transformSuper(qual) DOT sym1)()) - } - else { - staticCall(enteringPrevPhase(sym.overridingSymbol(implClass(sym.owner)))) - } - } - else { - assert(!siteWithinImplClass, currentOwner.enclClass) - tree - } + // add all new definitions to current class or interface + val statsWithNewDefs = addNewDefs(currentOwner, body) + statsWithNewDefs foreach { + case dd: DefDef if isTraitMethodRequiringStaticImpl(dd) => + dd.symbol.updateAttachment(NeedStaticImpl) case _ => - tree } + treeCopy.Template(tree, parents1, self, statsWithNewDefs) - case This(_) => - transformThis(tree) - - case Select(Super(_, _), name) => - tree + case Select(qual, name) if sym.owner.isTrait && !sym.isMethod => + assert(sym.hasFlag(PARAMACCESSOR | PRESUPER), s"!!! Unexpected reference to field $sym in trait $currentOwner") - case Select(qual, name) if sym.owner.isImplClass && !isStaticOnly(sym) => - assert(!sym.isMethod, "no method allowed here: %s%s %s".format(sym, sym.isImplOnly, sym.flagString)) - // refer to fields in some implementation class via an abstract - // getter in the interface. - val iface = toInterface(sym.owner.tpe).typeSymbol - val ifaceGetter = sym getterIn iface + // refer to fields in some trait an abstract getter in the interface. + val ifaceGetter = sym getterIn sym.owner - if (ifaceGetter == NoSymbol) abort("No getter for " + sym + " in " + iface) + if (ifaceGetter == NoSymbol) abort("No getter for " + sym + " in " + sym.owner) else typedPos(tree.pos)((qual DOT ifaceGetter)()) case Assign(Apply(lhs @ Select(qual, _), List()), rhs) => - // assign to fields in some implementation class via an abstract - // setter in the interface. - def setter = lhs.symbol.setterIn(toInterface(lhs.symbol.owner.tpe).typeSymbol) setPos lhs.pos + // assign to fields in some trait via an abstract setter in the interface. + // Note that the case above has added the empty application. + val setter = lhs.symbol.setterIn(lhs.symbol.owner.tpe.typeSymbol) setPos lhs.pos typedPos(tree.pos)((qual DOT setter)(rhs)) @@ -1262,4 +595,14 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL { finally localTyper = saved } } + + private def isTraitMethodRequiringStaticImpl(dd: DefDef): Boolean = { + val sym = dd.symbol + dd.rhs.nonEmpty && + sym.owner.isTrait && + !sym.isPrivate && // no need to put implementations of private methods into a static method + !sym.hasFlag(Flags.STATIC) + } + + case object NeedStaticImpl extends PlainAttachment } diff --git a/src/compiler/scala/tools/nsc/transform/OverridingPairs.scala b/src/compiler/scala/tools/nsc/transform/OverridingPairs.scala index e4082eb376..a861115cab 100644 --- a/src/compiler/scala/tools/nsc/transform/OverridingPairs.scala +++ b/src/compiler/scala/tools/nsc/transform/OverridingPairs.scala @@ -18,8 +18,6 @@ abstract class OverridingPairs extends SymbolPairs { import global._ class Cursor(base: Symbol) extends super.Cursor(base) { - lazy val relatively = new RelativeTo(base.thisType) - /** Symbols to exclude: Here these are constructors and private/artifact symbols, * including bridges. But it may be refined in subclasses. */ @@ -37,7 +35,7 @@ abstract class OverridingPairs extends SymbolPairs { (lo.owner != high.owner) // don't try to form pairs from overloaded members && !high.isPrivate // private or private[this] members never are overridden && !exclude(lo) // this admits private, as one can't have a private member that matches a less-private member. - && relatively.matches(lo, high) + && ((self memberType lo) matches (self memberType high)) ) // TODO we don't call exclude(high), should we? } } diff --git a/src/compiler/scala/tools/nsc/transform/SampleTransform.scala b/src/compiler/scala/tools/nsc/transform/SampleTransform.scala index ba303f7c2b..4c1705e386 100644 --- a/src/compiler/scala/tools/nsc/transform/SampleTransform.scala +++ b/src/compiler/scala/tools/nsc/transform/SampleTransform.scala @@ -35,7 +35,7 @@ abstract class SampleTransform extends Transform { atPos(tree1.pos)( // `atPos` fills in position of its tree argument Select( // The `Select` factory method is defined in class `Trees` sup, - currentOwner.newValue( // creates a new term symbol owned by `currentowner` + currentOwner.newValue( // creates a new term symbol owned by `currentOwner` newTermName("sample"), // The standard term name creator tree1.pos))))) case _ => diff --git a/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala b/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala index 53a1347a48..9161786d76 100644 --- a/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala +++ b/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala @@ -9,8 +9,6 @@ package transform import scala.tools.nsc.symtab.Flags import scala.collection.{ mutable, immutable } -import scala.language.postfixOps -import scala.language.existentials import scala.annotation.tailrec /** Specialize code on types. @@ -61,7 +59,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { val phaseName: String = "specialize" /** The following flags may be set by this phase: */ - override def phaseNewFlags: Long = notPRIVATE | lateFINAL + override def phaseNewFlags: Long = notPRIVATE /** This phase changes base classes. */ override def changesBaseClasses = true @@ -168,7 +166,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { /** Reduce the given environment to contain mappings only for type variables in tps. */ def restrict(env: TypeEnv, tps: immutable.Set[Symbol]): TypeEnv = - env filterKeys tps toMap + env.filterKeys(tps).toMap /** Is the given environment a valid specialization for sym? * It is valid if each binding is from a @specialized type parameter in sym (or its owner) @@ -285,6 +283,19 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { for ((tvar, tpe) <- sym.info.typeParams.zip(args) if !tvar.isSpecialized || !isPrimitiveValueType(tpe)) yield tpe + /** Is `member` potentially affected by specialization? This is a gross overapproximation, + * but it should be okay for use outside of specialization. + */ + def possiblySpecialized(sym: Symbol) = specializedTypeVars(sym).nonEmpty + + /** Refines possiblySpecialized taking into account the instantiation of the specialized type variables at `site` */ + def isSpecializedIn(sym: Symbol, site: Type) = + specializedTypeVars(sym) exists { tvar => + val concretes = concreteTypes(tvar) + (concretes contains AnyRefClass) || (concretes contains site.memberType(tvar)) + } + + val specializedType = new TypeMap { override def apply(tp: Type): Type = tp match { case TypeRef(pre, sym, args) if args.nonEmpty => @@ -354,7 +365,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { } ) - lazy val specializableTypes = ScalaValueClasses map (_.tpe) sorted + lazy val specializableTypes = ScalaValueClasses.map(_.tpe).sorted /** If the symbol is the companion of a value class, the value class. * Otherwise, AnyRef. @@ -373,7 +384,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { val types = if (!sym.isSpecialized) Nil // no @specialized Annotation else - specializedOn(sym) map (s => specializesClass(s).tpe) sorted + specializedOn(sym).map(s => specializesClass(s).tpe).sorted if (isBoundedGeneric(sym.tpe) && (types contains AnyRefClass)) reporter.warning(sym.pos, sym + " is always a subtype of " + AnyRefTpe + ".") @@ -461,7 +472,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { case ExistentialType(_, res) => specializedTypeVars(res) case AnnotatedType(_, tp) => specializedTypeVars(tp) case TypeBounds(lo, hi) => specializedTypeVars(lo :: hi :: Nil) - case RefinedType(parents, _) => parents flatMap specializedTypeVars toSet + case RefinedType(parents, _) => parents.flatMap(specializedTypeVars).toSet case _ => immutable.Set.empty } @@ -697,7 +708,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { else debuglog("conflicting env for " + m + " env: " + env) } - else if (m.isDeferred) { // abstract methods + else if (m.isDeferred && m.isSpecialized) { // abstract methods val specMember = enterMember(cloneInSpecializedClass(m, _ | DEFERRED)) // debuglog("deferred " + specMember.fullName + " remains abstract") @@ -705,14 +716,14 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { // was: new Forward(specMember) { // override def target = m.owner.info.member(specializedName(m, env)) // } - } else if (m.isMethod && !m.hasAccessorFlag) { // other concrete methods + } else if (!sClass.isTrait && m.isMethod && !m.hasAccessorFlag) { // other concrete methods // log("other concrete " + m) forwardToOverload(m) - } else if (m.isMethod && m.hasFlag(LAZY)) { + } else if (!sClass.isTrait && m.isMethod && m.hasFlag(LAZY)) { forwardToOverload(m) - } else if (m.isValue && !m.isMethod && !m.hasFlag(LAZY)) { // concrete value definition + } else if (m.isValue && !m.isMethod) { // concrete value definition def mkAccessor(field: Symbol, name: Name) = { val newFlags = (SPECIALIZED | m.getterIn(clazz).flags) & ~(LOCAL | CASEACCESSOR | PARAMACCESSOR) // we rely on the super class to initialize param accessors @@ -733,7 +744,14 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { enterMember(specVal) // create accessors - if (nme.isLocalName(m.name)) { + if (m.isLazy) { + // no getters needed (we'll specialize the compute method and accessor separately), can stay private + // m.setFlag(PRIVATE) -- TODO: figure out how to leave the non-specialized lazy var private + // (the implementation needs it to be visible while duplicating and retypechecking, + // but it really could be private in bytecode) + specVal.setFlag(PRIVATE) + } + else if (nme.isLocalName(m.name)) { val specGetter = mkAccessor(specVal, specVal.getterName) setInfo MethodType(Nil, specVal.info) val origGetter = overrideIn(sClass, m.getterIn(clazz)) info(origGetter) = Forward(specGetter) @@ -848,7 +866,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { if (unusedStvars.length == 1) "is" else "are") ) unusedStvars foreach (_ removeAnnotation SpecializedClass) - specializingOn = specializingOn filterNot (unusedStvars contains) + specializingOn = specializingOn filterNot (unusedStvars contains _) } for (env0 <- specializations(specializingOn) if needsSpecialization(env0, sym)) yield { // !!! Can't this logic be structured so that the new symbol's name is @@ -1008,7 +1026,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { case (NoSymbol, _) => if (overriding.isSuperAccessor) { val alias = overriding.alias - debuglog("checking special overload for super accessor: %s, alias for %s".format(overriding.fullName, alias.fullName)) + debuglog(s"checking special overload for super accessor: ${overriding.fullName}, alias for ${alias.fullName}") needsSpecialOverride(alias) match { case nope @ (NoSymbol, _) => None case (overridden, env) => @@ -1030,8 +1048,9 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { param.name = overriding.paramss(i)(j).name // SI-6555 Retain the parameter names from the subclass. } } - debuglog("specialized overload %s for %s in %s: %s".format(om, overriding.name.decode, pp(env), om.info)) - if (overriding.isAbstractOverride) om.setFlag(ABSOVERRIDE) + debuglog(s"specialized overload $om for ${overriding.name.decode} in ${pp(env)}: ${om.info}") + om.setFlag(overriding.flags & (ABSOVERRIDE | SYNCHRONIZED)) + om.withAnnotations(overriding.annotations.filter(_.symbol == ScalaStrictFPAttr)) typeEnv(om) = env addConcreteSpecMethod(overriding) if (overriding.isDeferred) { // abstract override @@ -1079,7 +1098,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { */ private def unify(tp1: Type, tp2: Type, env: TypeEnv, strict: Boolean, tparams: Boolean = false): TypeEnv = (tp1, tp2) match { case (TypeRef(_, sym1, _), _) if sym1.isSpecialized => - debuglog("Unify " + tp1 + ", " + tp2) + debuglog(s"Unify $tp1, $tp2") if (isPrimitiveValueClass(tp2.typeSymbol) || isSpecializedAnyRefSubtype(tp2, sym1)) env + ((sym1, tp2)) else if (isSpecializedAnyRefSubtype(tp2, sym1)) @@ -1090,20 +1109,20 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { env case (TypeRef(_, sym1, args1), TypeRef(_, sym2, args2)) => if (args1.nonEmpty || args2.nonEmpty) - debuglog("Unify types " + tp1 + " and " + tp2) + debuglog(s"Unify types $tp1 and $tp2") if (strict && args1.length != args2.length) unifyError(tp1, tp2) val e = unify(args1, args2, env, strict) - if (e.nonEmpty) debuglog("unified to: " + e) + if (e.nonEmpty) debuglog(s"unified to: $e") e case (TypeRef(_, sym1, _), _) if sym1.isTypeParameterOrSkolem => env case (MethodType(params1, res1), MethodType(params2, res2)) => if (strict && params1.length != params2.length) unifyError(tp1, tp2) - debuglog("Unify methods " + tp1 + " and " + tp2) + debuglog(s"Unify methods $tp1 and $tp2") unify(res1 :: (params1 map (_.tpe)), res2 :: (params2 map (_.tpe)), env, strict) case (PolyType(tparams1, res1), PolyType(tparams2, res2)) => - debuglog("Unify polytypes " + tp1 + " and " + tp2) + debuglog(s"Unify polytypes $tp1 and $tp2") if (strict && tparams1.length != tparams2.length) unifyError(tp1, tp2) else if (tparams && tparams1.length == tparams2.length) @@ -1121,7 +1140,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { case (ExistentialType(_, res1), _) => unify(tp2, res1, env, strict) case (TypeBounds(lo1, hi1), TypeBounds(lo2, hi2)) => unify(List(lo1, hi1), List(lo2, hi2), env, strict) case _ => - debuglog("don't know how to unify %s [%s] with %s [%s]".format(tp1, tp1.getClass, tp2, tp2.getClass)) + debuglog(s"don't know how to unify $tp1 [${tp1.getClass}] with $tp2 [${tp2.getClass}]") env } @@ -1131,9 +1150,9 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { if (!strict) unify(args._1, args._2, env, strict) else { val nenv = unify(args._1, args._2, emptyEnv, strict) - if (env.keySet intersect nenv.keySet isEmpty) env ++ nenv + if (env.keySet.intersect(nenv.keySet).isEmpty) env ++ nenv else { - debuglog("could not unify: u(" + args._1 + ", " + args._2 + ") yields " + nenv + ", env: " + env) + debuglog(s"could not unify: u(${args._1}, ${args._2}) yields $nenv, env: $env") unifyError(tp1, tp2) } } @@ -1229,7 +1248,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { env forall { case (tvar, tpe) => matches(tvar.info.bounds.lo, tpe) && matches(tpe, tvar.info.bounds.hi) || { if (warnings) - reporter.warning(tvar.pos, "Bounds prevent specialization of " + tvar) + reporter.warning(tvar.pos, s"Bounds prevent specialization of $tvar") debuglog("specvars: " + tvar.info.bounds.lo + ": " + @@ -1318,6 +1337,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { class SpecializationDuplicator(casts: Map[Symbol, Type]) extends Duplicator(casts) { override def retyped(context: Context, tree: Tree, oldThis: Symbol, newThis: Symbol, env: scala.collection.Map[Symbol, Type]): Tree = enteringSpecialize(super.retyped(context, tree, oldThis, newThis, env)) + } /** A tree symbol substituter that substitutes on type skolems. @@ -1360,7 +1380,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { sym, currentClass, sym.owner.enclClass, isAccessible(sym), nme.isLocalName(sym.name)) ) if (shouldMakePublic(sym) && !isAccessible(sym)) { - debuglog("changing private flag of " + sym) + debuglog(s"changing private flag of $sym") sym.makeNotPrivate(sym.owner) } super.transform(tree) @@ -1415,10 +1435,10 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { (treeType =:= memberType) || { // anyref specialization memberType match { case PolyType(_, resTpe) => - debuglog("Conformance for anyref - polytype with result type: " + resTpe + " and " + treeType + "\nOrig. sym.: " + origSymbol) + debuglog(s"Conformance for anyref - polytype with result type: $resTpe and $treeType\nOrig. sym.: $origSymbol") try { val e = unify(origSymbol.tpe, memberType, emptyEnv, true) - debuglog("obtained env: " + e) + debuglog(s"obtained env: $e") e.keySet == env.keySet } catch { case _: Throwable => @@ -1518,7 +1538,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { ) val tree1 = gen.mkTypeApply(specTree, residualTargs) - debuglog("rewrote " + tree + " to " + tree1) + debuglog(s"rewrote $tree to $tree1") localTyper.typedOperator(atPos(tree.pos)(tree1)) // being polymorphic, it must be a method } @@ -1526,7 +1546,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { tree match { case Apply(Select(New(tpt), nme.CONSTRUCTOR), args) => def transformNew = { - debuglog("Attempting to specialize new %s(%s)".format(tpt, args.mkString(", "))) + debuglog(s"Attempting to specialize new $tpt(${args.mkString(", ")})") val found = specializedType(tpt.tpe) if (found.typeSymbol ne tpt.tpe.typeSymbol) { // the ctor can be specialized val inst = New(found, transformTrees(args): _*) @@ -1900,8 +1920,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { /** Forward to the generic class constructor. If the current class initializes * specialized fields corresponding to parameters, it passes null to the superclass - * constructor. This saves the boxing cost for initializing generic fields that are - * never used. + * constructor. * * For example: * {{{ @@ -1915,7 +1934,17 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { * super.this(null.asInstanceOf[Int], null.asInstanceOf[Int]) * } * } - * }} + * }}} + * + * Note that erasure first transforms `null.asInstanceOf[Int]` to `unbox(null)`, which is 0. + * Then it adapts the argument `unbox(null)` of type Int to the erased parameter type of Tuple2, + * which is Object, so it inserts a `box` call and we get `box(unbox(null))`, which is + * `new Integer(0)` (not `null`). + * + * However it does not make sense to create an Integer instance to be stored in the generic field + * of the superclass: that field is never used. Therefore we mark the `null` tree with the + * [[SpecializedSuperConstructorCallArgument]] attachment and special-case erasure to replace + * `box(unbox(null))` by `null` in this case. */ private def forwardCtorCall(pos: scala.reflect.internal.util.Position, receiver: Tree, paramss: List[List[ValDef]], clazz: Symbol): Tree = { log(s"forwardCtorCall($pos, $receiver, $paramss, $clazz)") @@ -1934,7 +1963,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { val argss = mmap(paramss)(x => if (initializesSpecializedField(x.symbol)) - gen.mkAsInstanceOf(Literal(Constant(null)), x.symbol.tpe) + gen.mkAsInstanceOf(Literal(Constant(null)).updateAttachment(SpecializedSuperConstructorCallArgument), x.symbol.tpe) else Ident(x.symbol) ) @@ -1963,7 +1992,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { else exitingSpecialize(specializeCalls(unit).transform(tree)) // Remove the final modifier and @inline annotation from anything in the - // original class (since it's being overridden in at least onesubclass). + // original class (since it's being overridden in at least one subclass). // // We do this here so that the specialized subclasses will correctly copy // final and @inline. @@ -1978,5 +2007,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers { } resultTree - } } + } + } + object SpecializedSuperConstructorCallArgument } diff --git a/src/compiler/scala/tools/nsc/transform/Statics.scala b/src/compiler/scala/tools/nsc/transform/Statics.scala index 4673be6de7..776805fd9f 100644 --- a/src/compiler/scala/tools/nsc/transform/Statics.scala +++ b/src/compiler/scala/tools/nsc/transform/Statics.scala @@ -1,49 +1,32 @@ package scala.tools.nsc package transform -import collection.mutable.Buffer - abstract class Statics extends Transform with ast.TreeDSL { import global._ - class StaticsTransformer extends Transformer { - - /** finds the static ctor DefDef tree within the template if it exists. */ - def findStaticCtor(template: Template): Option[Tree] = - template.body find { - case defdef @ DefDef(_, nme.CONSTRUCTOR, _, _, _, _) => defdef.symbol.hasStaticFlag - case _ => false - } - - /** changes the template for the class so that it contains a static constructor with symbol fields inits, - * augments an existing static ctor if one already existed. + trait StaticsTransformer extends Transformer { + /** generate a static constructor with symbol fields inits, or an augmented existing static ctor */ - def addStaticInits(template: Template, newStaticInits: Buffer[Tree], localTyper: analyzer.Typer): Template = { - if (newStaticInits.isEmpty) - template - else { - val newCtor = findStaticCtor(template) match { - // in case there already were static ctors - augment existing ones - // currently, however, static ctors aren't being generated anywhere else - case Some(ctor @ DefDef(_,_,_,_,_,_)) => - // modify existing static ctor - deriveDefDef(ctor) { - case block @ Block(stats, expr) => - // need to add inits to existing block - treeCopy.Block(block, newStaticInits.toList ::: stats, expr) - case term: TermTree => - // need to create a new block with inits and the old term - treeCopy.Block(term, newStaticInits.toList, term) - } - case _ => - // create new static ctor - val staticCtorSym = currentClass.newStaticConstructor(template.pos) - val rhs = Block(newStaticInits.toList, Literal(Constant(()))) + def staticConstructor(body: List[Tree], localTyper: analyzer.Typer, pos: Position)(newStaticInits: List[Tree]): Tree = + body.collectFirst { + // If there already was a static ctor - augment existing one + // currently, however, static ctors aren't being generated anywhere else (!!!) + case ctor@DefDef(_, nme.CONSTRUCTOR, _, _, _, _) if ctor.symbol.hasStaticFlag => + // modify existing static ctor + deriveDefDef(ctor) { + case block@Block(stats, expr) => + // need to add inits to existing block + treeCopy.Block(block, newStaticInits ::: stats, expr) + case term: TermTree => + // need to create a new block with inits and the old term + treeCopy.Block(term, newStaticInits, term) + } + } getOrElse { + // create new static ctor + val staticCtorSym = currentClass.newStaticConstructor(pos) + val rhs = Block(newStaticInits, Literal(Constant(()))) - localTyper.typedPos(template.pos)(DefDef(staticCtorSym, rhs)) - } - deriveTemplate(template)(newCtor :: _) + localTyper.typedPos(pos)(DefDef(staticCtorSym, rhs)) } - } } } diff --git a/src/compiler/scala/tools/nsc/transform/TailCalls.scala b/src/compiler/scala/tools/nsc/transform/TailCalls.scala index 16ea3ea90f..9e3e8ff455 100644 --- a/src/compiler/scala/tools/nsc/transform/TailCalls.scala +++ b/src/compiler/scala/tools/nsc/transform/TailCalls.scala @@ -69,7 +69,7 @@ abstract class TailCalls extends Transform { * are optimized. Since 'this' is not a local variable, a dummy local val * is added and used as a label parameter. The backend knows to load * the corresponding argument in the 'this' (local at index 0). This dummy local - * is never used and should be cleand up by dead code elimination (when enabled). + * is never used and should be cleaned up by dead code elimination (when enabled). * </p> * <p> * This phase has been moved before pattern matching to catch more @@ -84,7 +84,7 @@ abstract class TailCalls extends Transform { * </p> * <p> * Assumes: `Uncurry` has been run already, and no multiple - * parameter lists exit. + * parameter lists exist. * </p> */ class TailCallElimination(unit: CompilationUnit) extends Transformer { @@ -274,10 +274,8 @@ abstract class TailCalls extends Transform { import runDefinitions.{Boolean_or, Boolean_and} tree match { - case ValDef(_, _, _, _) => - if (tree.symbol.isLazy && tree.symbol.hasAnnotation(TailrecClass)) - reporter.error(tree.pos, "lazy vals are not tailcall transformed") - + case dd: DefDef if tree.symbol.isLazy && tree.symbol.hasAnnotation(TailrecClass) => + reporter.error(tree.pos, "lazy vals are not tailcall transformed") super.transform(tree) case dd @ DefDef(_, name, _, vparamss0, _, rhs0) if isEligible(dd) => diff --git a/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala b/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala index 3b23306386..52d7c0b897 100644 --- a/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala +++ b/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala @@ -1,90 +1,64 @@ package scala.tools.nsc package transform +import scala.annotation.tailrec import scala.tools.nsc.ast.TreeDSL -import scala.tools.nsc.Global /** * A trait usable by transforms that need to adapt trees of one type to another type */ -trait TypeAdaptingTransformer { - self: TreeDSL => - - val analyzer: typechecker.Analyzer { val global: self.global.type } - - trait TypeAdapter { - val typer: analyzer.Typer +trait TypeAdaptingTransformer { self: TreeDSL => + abstract class TypeAdapter { import global._ import definitions._ - import CODE._ - def isMethodTypeWithEmptyParams(tpe: Type) = tpe match { - case MethodType(Nil, _) => true - case _ => false - } + def typedPos(pos: Position)(tree: Tree): Tree + /** + * SI-4148: can't always replace box(unbox(x)) by x because + * - unboxing x may lead to throwing an exception, e.g. in "aah".asInstanceOf[Int] + * - box(unbox(null)) is not `null` but the box of zero + */ private def isSafelyRemovableUnbox(fn: Tree, arg: Tree): Boolean = { - currentRun.runDefinitions.isUnbox(fn.symbol) && { - val cls = arg.tpe.typeSymbol - (cls == definitions.NullClass) || isBoxedValueClass(cls) - } + currentRun.runDefinitions.isUnbox(fn.symbol) && { + // replace box(unbox(null)) by null when passed to the super constructor in a specialized + // class, see comment in SpecializeTypes.forwardCtorCall. + arg.hasAttachment[specializeTypes.SpecializedSuperConstructorCallArgument.type] || + isBoxedValueClass(arg.tpe.typeSymbol) + } } - private def isPrimitiveValueType(tpe: Type) = isPrimitiveValueClass(tpe.typeSymbol) - - private def isErasedValueType(tpe: Type) = tpe.isInstanceOf[ErasedValueType] - - private def isDifferentErasedValueType(tpe: Type, other: Type) = - isErasedValueType(tpe) && (tpe ne other) + private def isPrimitiveValueType(tpe: Type) = isPrimitiveValueClass(tpe.typeSymbol) + final def isPrimitiveValueMember(sym: Symbol) = isPrimitiveValueClass(sym.owner) + final def isMethodTypeWithEmptyParams(tpe: Type) = tpe.isInstanceOf[MethodType] && tpe.params.isEmpty + final def applyMethodWithEmptyParams(qual: Tree) = Apply(qual, List()) setPos qual.pos setType qual.tpe.resultType - def isPrimitiveValueMember(sym: Symbol) = isPrimitiveValueClass(sym.owner) - - @inline def box(tree: Tree, target: => String): Tree = { - val result = box1(tree) - if (tree.tpe =:= UnitTpe) () - else log(s"boxing ${tree.summaryString}: ${tree.tpe} into $target: ${result.tpe}") - result - } + import CODE._ /** Box `tree` of unboxed type */ - private def box1(tree: Tree): Tree = tree match { + final def box(tree: Tree): Tree = tree match { case LabelDef(_, _, _) => - val ldef = deriveLabelDef(tree)(box1) + val ldef = deriveLabelDef(tree)(box) ldef setType ldef.rhs.tpe case _ => val tree1 = tree.tpe match { - case ErasedValueType(clazz, _) => - New(clazz, cast(tree, underlyingOfValueClass(clazz))) - case _ => - tree.tpe.typeSymbol match { - case UnitClass => - if (treeInfo isExprSafeToInline tree) REF(BoxedUnit_UNIT) - else BLOCK(tree, REF(BoxedUnit_UNIT)) - case NothingClass => tree // a non-terminating expression doesn't need boxing - case x => - assert(x != ArrayClass) - tree match { - /* Can't always remove a Box(Unbox(x)) combination because the process of boxing x - * may lead to throwing an exception. - * - * This is important for specialization: calls to the super constructor should not box/unbox specialized - * fields (see TupleX). (ID) - */ - case Apply(boxFun, List(arg)) if isSafelyRemovableUnbox(tree, arg) => - log(s"boxing an unbox: ${tree.symbol} -> ${arg.tpe}") - arg - case _ => - (REF(currentRun.runDefinitions.boxMethod(x)) APPLY tree) setPos (tree.pos) setType ObjectTpe - } - } + case ErasedValueType(clazz, _) => New(clazz, cast(tree, underlyingOfValueClass(clazz))) + case _ => tree.tpe.typeSymbol match { + case UnitClass => + if (treeInfo isExprSafeToInline tree) REF(BoxedUnit_UNIT) + else BLOCK(tree, REF(BoxedUnit_UNIT)) + case NothingClass => tree // a non-terminating expression doesn't need boxing + case x => + assert(x != ArrayClass) + tree match { + case Apply(boxFun, List(arg)) if isSafelyRemovableUnbox(tree, arg) => + arg + case _ => + (REF(currentRun.runDefinitions.boxMethod(x)) APPLY tree) setPos (tree.pos) setType ObjectTpe + } + } } - typer.typedPos(tree.pos)(tree1) - } - - def unbox(tree: Tree, pt: Type): Tree = { - val result = unbox1(tree, pt) - log(s"unboxing ${tree.shortClass}: ${tree.tpe} as a ${result.tpe}") - result + typedPos(tree.pos)(tree1) } /** Unbox `tree` of boxed type to expected type `pt`. @@ -93,27 +67,13 @@ trait TypeAdaptingTransformer { * @param pt the expected type. * @return the unboxed tree */ - private def unbox1(tree: Tree, pt: Type): Tree = tree match { -/* - case Boxed(unboxed) => - println("unbox shorten: "+tree) // this never seems to kick in during build and test; therefore disabled. - adaptToType(unboxed, pt) - */ + final def unbox(tree: Tree, pt: Type): Tree = tree match { case LabelDef(_, _, _) => val ldef = deriveLabelDef(tree)(unbox(_, pt)) ldef setType ldef.rhs.tpe case _ => val tree1 = pt match { - case ErasedValueType(clazz, underlying) => - val tree0 = - if (tree.tpe.typeSymbol == NullClass && - isPrimitiveValueClass(underlying.typeSymbol)) { - // convert `null` directly to underlying type, as going - // via the unboxed type would yield a NPE (see SI-5866) - unbox1(tree, underlying) - } else - Apply(Select(adaptToType(tree, clazz.tpe), clazz.derivedValueClassUnbox), List()) - cast(tree0, pt) + case ErasedValueType(clazz, underlying) => cast(unboxValueClass(tree, clazz, underlying), pt) case _ => pt.typeSymbol match { case UnitClass => @@ -125,21 +85,28 @@ trait TypeAdaptingTransformer { Apply(currentRun.runDefinitions.unboxMethod(pt.typeSymbol), tree) } } - typer.typedPos(tree.pos)(tree1) + typedPos(tree.pos)(tree1) } + final def unboxValueClass(tree: Tree, clazz: Symbol, underlying: Type): Tree = + if (tree.tpe.typeSymbol == NullClass && isPrimitiveValueClass(underlying.typeSymbol)) { + // convert `null` directly to underlying type, as going via the unboxed type would yield a NPE (see SI-5866) + unbox(tree, underlying) + } else + Apply(Select(adaptToType(tree, clazz.tpe), clazz.derivedValueClassUnbox), List()) + /** Generate a synthetic cast operation from tree.tpe to pt. - * @pre pt eq pt.normalize + * + * @pre pt eq pt.normalize */ - def cast(tree: Tree, pt: Type): Tree = { - if ((tree.tpe ne null) && !(tree.tpe =:= ObjectTpe)) { - def word = ( + final def cast(tree: Tree, pt: Type): Tree = { + if (settings.debug && (tree.tpe ne null) && !(tree.tpe =:= ObjectTpe)) { + def word = if (tree.tpe <:< pt) "upcast" else if (pt <:< tree.tpe) "downcast" else if (pt weak_<:< tree.tpe) "coerce" else if (tree.tpe weak_<:< pt) "widen" else "cast" - ) log(s"erasure ${word}s from ${tree.tpe} to $pt") } if (pt =:= UnitTpe) { @@ -160,27 +127,23 @@ trait TypeAdaptingTransformer { * @param pt the expected type * @return the adapted tree */ - def adaptToType(tree: Tree, pt: Type): Tree = { - if (settings.debug && pt != WildcardType) - log("adapting " + tree + ":" + tree.tpe + " : " + tree.tpe.parents + " to " + pt)//debug - if (tree.tpe <:< pt) - tree - else if (isDifferentErasedValueType(tree.tpe, pt)) - adaptToType(box(tree, pt.toString), pt) - else if (isDifferentErasedValueType(pt, tree.tpe)) - adaptToType(unbox(tree, pt), pt) - else if (isPrimitiveValueType(tree.tpe) && !isPrimitiveValueType(pt)) { - adaptToType(box(tree, pt.toString), pt) - } else if (isMethodTypeWithEmptyParams(tree.tpe)) { - // [H] this assert fails when trying to typecheck tree !(SomeClass.this.bitmap) for single lazy val - //assert(tree.symbol.isStable, "adapt "+tree+":"+tree.tpe+" to "+pt) - adaptToType(Apply(tree, List()) setPos tree.pos setType tree.tpe.resultType, pt) -// } else if (pt <:< tree.tpe) -// cast(tree, pt) - } else if (isPrimitiveValueType(pt) && !isPrimitiveValueType(tree.tpe)) - adaptToType(unbox(tree, pt), pt) - else - cast(tree, pt) + @tailrec final def adaptToType(tree: Tree, pt: Type): Tree = { + val tpe = tree.tpe + + if ((tpe eq pt) || tpe <:< pt) tree + else if (tpe.isInstanceOf[ErasedValueType]) adaptToType(box(tree), pt) // what if pt is an erased value type? + else if (pt.isInstanceOf[ErasedValueType]) adaptToType(unbox(tree, pt), pt) + // See corresponding case in `Eraser`'s `adaptMember` + // [H] this does not hold here, however: `assert(tree.symbol.isStable)` (when typechecking !(SomeClass.this.bitmap) for single lazy val) + else if (isMethodTypeWithEmptyParams(tpe)) adaptToType(applyMethodWithEmptyParams(tree), pt) + else { + val gotPrimitiveVC = isPrimitiveValueType(tpe) + val expectedPrimitiveVC = isPrimitiveValueType(pt) + + if (gotPrimitiveVC && !expectedPrimitiveVC) adaptToType(box(tree), pt) + else if (!gotPrimitiveVC && expectedPrimitiveVC) adaptToType(unbox(tree, pt), pt) + else cast(tree, pt) + } } } } diff --git a/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala index dc3313e2e4..d5adfe12e9 100644 --- a/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala +++ b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala @@ -26,7 +26,7 @@ trait TypingTransformers { def atOwner[A](tree: Tree, owner: Symbol)(trans: => A): A = { val savedLocalTyper = localTyper - localTyper = localTyper.atOwner(tree, if (owner.isModule) owner.moduleClass else owner) + localTyper = localTyper.atOwner(tree, if (owner.isModuleNotMethod) owner.moduleClass else owner) val result = super.atOwner(owner)(trans) localTyper = savedLocalTyper result diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala index d5a7213cfb..f35dd6556f 100644 --- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala +++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala @@ -7,9 +7,10 @@ package scala package tools.nsc package transform +import scala.annotation.tailrec + import symtab.Flags._ -import scala.collection.{ mutable, immutable } -import scala.language.postfixOps +import scala.collection.mutable import scala.reflect.internal.util.ListOfNil /*<export> */ @@ -68,19 +69,30 @@ abstract class UnCurry extends InfoTransform // uncurry and uncurryType expand type aliases class UnCurryTransformer(unit: CompilationUnit) extends TypingTransformer(unit) { - private val inlineFunctionExpansion = settings.Ydelambdafy.value == "inline" + private val forceExpandFunction = settings.Ydelambdafy.value == "inline" private var needTryLift = false private var inConstructorFlag = 0L private val byNameArgs = mutable.HashSet[Tree]() private val noApply = mutable.HashSet[Tree]() private val newMembers = mutable.Map[Symbol, mutable.Buffer[Tree]]() - private lazy val forceSpecializationInfoTransformOfFunctionN: Unit = { - if (currentRun.specializePhase != NoPhase) { // be robust in case of -Ystop-after:uncurry - exitingSpecialize { - FunctionClass.seq.foreach(cls => cls.info) - } - } + // Expand `Function`s in constructors to class instance creation (SI-6666, SI-8363) + // We use Java's LambdaMetaFactory (LMF), which requires an interface for the sam's owner + private def mustExpandFunction(fun: Function) = { + // (TODO: Can't use isInterface, yet, as it hasn't been updated for the new trait encoding) + val canUseLambdaMetaFactory = (fun.attachments.get[SAMFunction] match { + case Some(SAMFunction(userDefinedSamTp, sam)) => + // LambdaMetaFactory cannot mix in trait members for us, or instantiate classes -- only pure interfaces need apply + erasure.compilesToPureInterface(erasure.javaErasure(userDefinedSamTp).typeSymbol) && + // impl restriction -- we currently use the boxed apply, so not really useful to allow specialized sam types (https://github.com/scala/scala/pull/4971#issuecomment-198119167) + // specialization and LMF are at odds, since LMF implements the single abstract method, + // but that's the one that specialization leaves generic, whereas we need to implement the specialized one to avoid boxing + !specializeTypes.isSpecializedIn(sam, userDefinedSamTp) + + case _ => true // our built-in FunctionN's are suitable for LambdaMetaFactory by construction + }) + + !canUseLambdaMetaFactory } /** Add a new synthetic member for `currentOwner` */ @@ -91,25 +103,17 @@ abstract class UnCurry extends InfoTransform @inline private def useNewMembers[T](owner: Symbol)(f: List[Tree] => T): T = f(newMembers.remove(owner).getOrElse(Nil).toList) - private def newFunction0(body: Tree): Tree = { - val result = localTyper.typedPos(body.pos)(Function(Nil, body)).asInstanceOf[Function] - log("Change owner from %s to %s in %s".format(currentOwner, result.symbol, result.body)) - result.body changeOwner (currentOwner -> result.symbol) - transformFunction(result) - } - // I don't have a clue why I'm catching TypeErrors here, but it's better // than spewing stack traces at end users for internal errors. Examples // which hit at this point should not be hard to come by, but the immediate // motivation can be seen in continuations-neg/t3718. - override def transform(tree: Tree): Tree = ( + override def transform(tree: Tree): Tree = try postTransform(mainTransform(tree)) catch { case ex: TypeError => reporter.error(ex.pos, ex.msg) debugStack(ex) EmptyTree } - ) /* Is tree a reference `x` to a call by name parameter that needs to be converted to * x.apply()? Note that this is not the case if `x` is used as an argument to another @@ -118,7 +122,7 @@ abstract class UnCurry extends InfoTransform def isByNameRef(tree: Tree) = ( tree.isTerm && (tree.symbol ne null) - && (isByName(tree.symbol)) + && isByName(tree.symbol) && !byNameArgs(tree) ) @@ -195,16 +199,6 @@ abstract class UnCurry extends InfoTransform // ------ Transforming anonymous functions and by-name-arguments ---------------- - /** Undo eta expansion for parameterless and nullary methods */ - def deEta(fun: Function): Tree = fun match { - case Function(List(), expr) if isByNameRef(expr) => - noApply += expr - expr - case _ => - fun - } - - /** Transform a function node (x_1,...,x_n) => body of type FunctionN[T_1, .., T_N, R] to * * class $anon() extends AbstractFunctionN[T_1, .., T_N, R] with Serializable { @@ -213,66 +207,38 @@ abstract class UnCurry extends InfoTransform * new $anon() * */ - def transformFunction(fun: Function): Tree = { - fun.tpe match { - // can happen when analyzer plugins assign refined types to functions, e.g. - // (() => Int) { def apply(): Int @typeConstraint } - case RefinedType(List(funTp), decls) => - debuglog(s"eliminate refinement from function type ${fun.tpe}") - fun.setType(funTp) - case _ => - () - } - - deEta(fun) match { - // nullary or parameterless - case fun1 if fun1 ne fun => fun1 - case _ => - def typedFunPos(t: Tree) = localTyper.typedPos(fun.pos)(t) - val funParams = fun.vparams map (_.symbol) - def mkMethod(owner: Symbol, name: TermName, additionalFlags: FlagSet = NoFlags): DefDef = - gen.mkMethodFromFunction(localTyper)(fun, owner, name, additionalFlags) - - def isSpecialized = { - forceSpecializationInfoTransformOfFunctionN - val specialized = specializeTypes.specializedType(fun.tpe) - !(specialized =:= fun.tpe) - } + def transformFunction(fun: Function): Tree = + // Undo eta expansion for parameterless and nullary methods, EXCEPT if `fun` targets a SAM. + // Normally, we can unwrap `() => cbn` to `cbn` where `cbn` refers to a CBN argument (typically `cbn` is an Ident), + // because we know `cbn` will already be a `Function0` thunk. When we're targeting a SAM, + // the types don't align and we must preserve the function wrapper. + if (fun.vparams.isEmpty && isByNameRef(fun.body) && fun.attachments.get[SAMFunction].isEmpty) { noApply += fun.body ; fun.body } + else if (forceExpandFunction || inConstructorFlag != 0) { + // Expand the function body into an anonymous class + gen.expandFunction(localTyper)(fun, inConstructorFlag) + } else { + val mustExpand = mustExpandFunction(fun) + // method definition with the same arguments, return type, and body as the original lambda + val liftedMethod = gen.mkLiftedFunctionBodyMethod(localTyper)(fun.symbol.owner, fun) + + // new function whose body is just a call to the lifted method + val newFun = deriveFunction(fun)(_ => localTyper.typedPos(fun.pos)( + gen.mkForwarder(gen.mkAttributedRef(liftedMethod.symbol), (fun.vparams map (_.symbol)) :: Nil) + )) - def canUseDelamdafyMethod = ( - (inConstructorFlag == 0) // Avoiding synthesizing code prone to SI-6666, SI-8363 by using old-style lambda translation - && (!isSpecialized || (settings.isBCodeActive && settings.target.value == "jvm-1.8")) // DelambdafyTransformer currently only emits generic FunctionN-s, use the old style in the meantime - ) - if (inlineFunctionExpansion || !canUseDelamdafyMethod) { - val parents = addSerializable(abstractFunctionForFunctionType(fun.tpe)) - val anonClass = fun.symbol.owner newAnonymousFunctionClass(fun.pos, inConstructorFlag) addAnnotation SerialVersionUIDAnnotation - // The original owner is used in the backend for the EnclosingMethod attribute. If fun is - // nested in a value-class method, its owner was already changed to the extension method. - // Saving the original owner allows getting the source structure from the class symbol. - defineOriginalOwner(anonClass, fun.symbol.originalOwner) - anonClass setInfo ClassInfoType(parents, newScope, anonClass) - - val applyMethodDef = mkMethod(anonClass, nme.apply) - anonClass.info.decls enter applyMethodDef.symbol - - typedFunPos { - Block( - ClassDef(anonClass, NoMods, ListOfNil, List(applyMethodDef), fun.pos), - Typed(New(anonClass.tpe), TypeTree(fun.tpe))) - } - } else { - // method definition with the same arguments, return type, and body as the original lambda - val liftedMethod = mkMethod(fun.symbol.owner, nme.ANON_FUN_NAME, additionalFlags = ARTIFACT) - - // new function whose body is just a call to the lifted method - val newFun = deriveFunction(fun)(_ => typedFunPos( - gen.mkForwarder(gen.mkAttributedRef(liftedMethod.symbol), funParams :: Nil) - )) - typedFunPos(Block(liftedMethod, super.transform(newFun))) - } + if (!mustExpand) { + liftedMethod.symbol.updateAttachment(DelambdafyTarget) + liftedMethod.updateAttachment(DelambdafyTarget) } - } + val typedNewFun = localTyper.typedPos(fun.pos)(Block(liftedMethod, super.transform(newFun))) + if (mustExpand) { + val Block(stats, expr : Function) = typedNewFun + treeCopy.Block(typedNewFun, stats, gen.expandFunction(localTyper)(expr, inConstructorFlag)) + } else { + typedNewFun + } + } def transformArgs(pos: Position, fun: Symbol, args: List[Tree], formals: List[Type]) = { val isJava = fun.isJavaDefined @@ -350,25 +316,22 @@ abstract class UnCurry extends InfoTransform val args1 = if (isVarArgTypes(formals)) transformVarargs(formals.last.typeArgs.head) else args map2(formals, args1) { (formal, arg) => - if (!isByNameParamType(formal)) - arg - else if (isByNameRef(arg)) { + if (!isByNameParamType(formal)) arg + else if (isByNameRef(arg)) { // thunk does not need to be forced because it's a reference to a by-name arg passed to a by-name param byNameArgs += arg arg setType functionType(Nil, arg.tpe) - } - else { + } else { log(s"Argument '$arg' at line ${arg.pos.line} is $formal from ${fun.fullName}") - def canUseDirectly(recv: Tree) = ( - recv.tpe.typeSymbol.isSubClass(FunctionClass(0)) - && treeInfo.isExprSafeToInline(recv) - ) + def canUseDirectly(qual: Tree) = qual.tpe.typeSymbol.isSubClass(FunctionClass(0)) && treeInfo.isExprSafeToInline(qual) arg match { // don't add a thunk for by-name argument if argument already is an application of // a Function0. We can then remove the application and use the existing Function0. - case Apply(Select(recv, nme.apply), Nil) if canUseDirectly(recv) => - recv - case _ => - newFunction0(arg) + case Apply(Select(qual, nme.apply), Nil) if canUseDirectly(qual) => qual + case body => + val thunkFun = localTyper.typedPos(body.pos)(Function(Nil, body)).asInstanceOf[Function] + log(s"Change owner from $currentOwner to ${thunkFun.symbol} in ${thunkFun.body}") + thunkFun.body.changeOwner((currentOwner, thunkFun.symbol)) + transformFunction(thunkFun) } } } @@ -379,23 +342,33 @@ abstract class UnCurry extends InfoTransform * the whole tree with it. */ private def replaceElidableTree(tree: Tree): Tree = { + def elisionOf(t: Type): Tree = t.typeSymbol match { + case StringClass => Literal(Constant("")) setType t + case _ => gen.mkZero(t) + } tree match { - case DefDef(_,_,_,_,_,_) => - deriveDefDef(tree)(rhs => Block(Nil, gen.mkZero(rhs.tpe)) setType rhs.tpe) setSymbol tree.symbol setType tree.tpe + case DefDef(_,_,_,_,_,rhs) => + val rhs1 = if (rhs == EmptyTree) rhs else Block(Nil, elisionOf(rhs.tpe)) setType rhs.tpe + deriveDefDef(tree)(_ => rhs1) setSymbol tree.symbol setType tree.tpe case _ => - gen.mkZero(tree.tpe) setType tree.tpe + elisionOf(tree.tpe) } } private def isSelfSynchronized(ddef: DefDef) = ddef.rhs match { case Apply(fn @ TypeApply(Select(sel, _), _), _) => - fn.symbol == Object_synchronized && sel.symbol == ddef.symbol.enclClass && !ddef.symbol.enclClass.isTrait + fn.symbol == Object_synchronized && sel.symbol == ddef.symbol.enclClass && !ddef.symbol.enclClass.isTrait && + !ddef.symbol.isDelambdafyTarget /* these become static later, unsuitable for ACC_SYNCHRONIZED */ case _ => false } /** If an eligible method is entirely wrapped in a call to synchronized * locked on the same instance, remove the synchronized scaffolding and * mark the method symbol SYNCHRONIZED for bytecode generation. + * + * Delambdafy targets are deemed ineligible as the Delambdafy phase will + * replace `this.synchronized` with `$this.synchronized` now that it emits + * all lambda impl methods as static. */ private def translateSynchronized(tree: Tree) = tree match { case dd @ DefDef(_, _, _, _, _, Apply(fn, body :: Nil)) if isSelfSynchronized(dd) => @@ -438,10 +411,20 @@ abstract class UnCurry extends InfoTransform val sym = tree.symbol // true if the target is a lambda body that's been lifted into a method - def isLiftedLambdaBody(target: Tree) = target.symbol.isLocalToBlock && target.symbol.isArtifact && target.symbol.name.containsName(nme.ANON_FUN_NAME) + def isLiftedLambdaMethod(funSym: Symbol) = + funSym.isArtifact && funSym.name.containsName(nme.ANON_FUN_NAME) && funSym.isLocalToBlock - val result = ( - if ((sym ne null) && sym.elisionLevel.exists(_ < settings.elidebelow.value)) + def checkIsElisible(sym: Symbol): Boolean = + (sym ne null) && sym.elisionLevel.exists { level => + if (sym.isMethod) level < settings.elidebelow.value + else { + if (settings.isScala213) reporter.error(sym.pos, s"${sym.name}: Only methods can be marked @elidable!") + false + } + } + + val result = + if (checkIsElisible(sym)) replaceElidableTree(tree) else translateSynchronized(tree) match { case dd @ DefDef(mods, name, tparams, _, tpt, rhs) => @@ -473,9 +456,9 @@ abstract class UnCurry extends InfoTransform super.transform(treeCopy.DefDef(dd, mods, name, tparams, vparamssNoRhs, tpt, rhs)) } } - case ValDef(_, _, _, rhs) => + case ValDef(mods, _, _, rhs) => if (sym eq NoSymbol) throw new IllegalStateException("Encountered Valdef without symbol: "+ tree + " in "+ unit) - if (!sym.owner.isSourceMethod) + if (!sym.owner.isSourceMethod || mods.isLazy) withNeedLift(needLift = true) { super.transform(tree) } else super.transform(tree) @@ -493,7 +476,7 @@ abstract class UnCurry extends InfoTransform case Assign(lhs, _) if lhs.symbol.owner != currentMethod || lhs.symbol.hasFlag(LAZY | ACCESSOR) => withNeedLift(needLift = true) { super.transform(tree) } - case ret @ Return(_) if (isNonLocalReturn(ret)) => + case ret @ Return(_) if isNonLocalReturn(ret) => withNeedLift(needLift = true) { super.transform(ret) } case Try(_, Nil, _) => @@ -512,7 +495,7 @@ abstract class UnCurry extends InfoTransform treeCopy.CaseDef(tree, pat1, transform(guard), transform(body)) // if a lambda is already the right shape we don't need to transform it again - case fun @ Function(_, Apply(target, _)) if (!inlineFunctionExpansion) && isLiftedLambdaBody(target) => + case fun @ Function(_, Apply(target, _)) if !forceExpandFunction && isLiftedLambdaMethod(target.symbol) => super.transform(fun) case fun @ Function(_, _) => @@ -532,9 +515,8 @@ abstract class UnCurry extends InfoTransform } tree1 } - ) - assert(result.tpe != null, result.shortClass + " tpe is null:\n" + result) - result modifyType uncurry + + result.setType(uncurry(result.tpe)) } def postTransform(tree: Tree): Tree = exitingUncurry { @@ -545,15 +527,18 @@ abstract class UnCurry extends InfoTransform case MethodType(_, _) => tree case tp => tree setType MethodType(Nil, tp.resultType) } - if (tree.symbol.isMethod && !tree.tpe.isInstanceOf[PolyType]) - gen.mkApplyIfNeeded(removeNullary()) + val sym = tree.symbol + // our info transformer may not have run yet, so duplicate flag logic instead of forcing it to run + val isMethodExitingUncurry = (sym hasFlag METHOD) || (sym hasFlag MODULE) && !sym.isStatic + if (isMethodExitingUncurry && !tree.tpe.isInstanceOf[PolyType]) + gen.mkApplyIfNeeded(removeNullary()) // apply () if tree.tpe has zero-arg MethodType else if (tree.isType) TypeTree(tree.tpe) setPos tree.pos else tree } - def isThrowable(pat: Tree): Boolean = pat match { + @tailrec def isThrowable(pat: Tree): Boolean = pat match { case Typed(Ident(nme.WILDCARD), tpt) => tpt.tpe =:= ThrowableTpe case Bind(_, pat) => @@ -579,6 +564,7 @@ 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 @@ -590,11 +576,22 @@ 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 } ) // Only class members can reasonably be called from Java due to name mangling. @@ -619,7 +616,7 @@ abstract class UnCurry extends InfoTransform case Select(_, _) | TypeApply(_, _) => applyUnary() case ret @ Return(expr) if isNonLocalReturn(ret) => - log("non-local return from %s to %s".format(currentOwner.enclMethod, ret.symbol)) + log(s"non-local return from ${currentOwner.enclMethod} to ${ret.symbol}") atPos(ret.pos)(nonLocalReturnThrow(expr, ret.symbol)) case TypeTree() => tree @@ -712,7 +709,7 @@ abstract class UnCurry extends InfoTransform // // So what we need to do is to use the pre-uncurry type when creating `l$1`, which is `c.Tree` and is // correct. Now, there are two additional problems: - // 1. when varargs and byname params are involved, the uncurry transformation desugares these special + // 1. when varargs and byname params are involved, the uncurry transformation desugars these special // cases to actual typerefs, eg: // ``` // T* ~> Seq[T] (Scala-defined varargs) @@ -744,7 +741,7 @@ abstract class UnCurry extends InfoTransform case Packed(param, tempVal) => (param, tempVal) }.unzip - val rhs1 = if (tempVals.isEmpty) rhs else { + val rhs1 = if (rhs == EmptyTree || tempVals.isEmpty) rhs else { localTyper.typedPos(rhs.pos) { // Patch the method body to refer to the temp vals val rhsSubstituted = rhs.substituteSymbols(packedParams map (_.symbol), tempVals map (_.symbol)) diff --git a/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala b/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala index 40fcceb0bf..db6eac34cb 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala @@ -8,9 +8,9 @@ package scala package tools.nsc.transform.patmat import scala.language.postfixOps + import scala.collection.mutable import scala.reflect.internal.util.{NoPosition, Position, Statistics, HashSet} -import scala.tools.nsc.Global trait Logic extends Debugging { import PatternMatchingStats._ @@ -184,8 +184,8 @@ trait Logic extends Debugging { // push negation inside formula def negationNormalFormNot(p: Prop): Prop = p match { - case And(ops) => Or(ops.map(negationNormalFormNot)) // De'Morgan - case Or(ops) => And(ops.map(negationNormalFormNot)) // De'Morgan + case And(ops) => Or(ops.map(negationNormalFormNot)) // De Morgan + case Or(ops) => And(ops.map(negationNormalFormNot)) // De Morgan case Not(p) => negationNormalForm(p) case True => False case False => True @@ -646,7 +646,7 @@ trait ScalaLogic extends Interface with Logic with TreeAndTypeAnalysis { } - import global.{ConstantType, Constant, EmptyScope, SingletonType, Literal, Ident, refinedType, singleType, TypeBounds, NoSymbol} + import global.{ConstantType, SingletonType, Literal, Ident, singleType, TypeBounds, NoSymbol} import global.definitions._ @@ -682,7 +682,7 @@ trait ScalaLogic extends Interface with Logic with TreeAndTypeAnalysis { private[TreesAndTypesDomain] def uniqueTpForTree(t: Tree): Type = { def freshExistentialSubtype(tp: Type): Type = { // SI-8611 tp.narrow is tempting, but unsuitable. See `testRefinedTypeSI8611` for an explanation. - NoSymbol.freshExistential("").setInfo(TypeBounds.upper(tp)).tpe + NoSymbol.freshExistential("", 0).setInfo(TypeBounds.upper(tp)).tpe } if (!t.symbol.isStable) { diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala index c71299b893..b6978f37df 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala @@ -6,9 +6,6 @@ package scala.tools.nsc.transform.patmat -import scala.annotation.tailrec -import scala.collection.immutable.{IndexedSeq, Iterable} -import scala.language.postfixOps import scala.collection.mutable import scala.reflect.internal.util.Statistics @@ -142,7 +139,7 @@ trait TreeAndTypeAnalysis extends Debugging { if(grouped) { def enumerateChildren(sym: Symbol) = { - sym.children.toList + sym.sealedChildren.toList .sortBy(_.sealedSortName) .filterNot(x => x.isSealed && x.isAbstractClass && !isPrimitiveValueClass(x)) } @@ -177,6 +174,8 @@ trait TreeAndTypeAnalysis extends Debugging { filterChildren(subclasses) }) } + case sym if sym.isCase => + List(List(tp)) case sym => debug.patmat("enum unsealed "+ ((tp, sym, sym.isSealed, isPrimitiveValueClass(sym)))) @@ -350,7 +349,7 @@ trait MatchApproximation extends TreeAndTypeAnalysis with ScalaLogic with MatchT object condStrategy extends TypeTestTreeMaker.TypeTestCondStrategy { type Result = Prop def and(a: Result, b: Result) = And(a, b) - def outerTest(testedBinder: Symbol, expectedTp: Type) = True // TODO OuterEqProp(testedBinder, expectedType) + def withOuterTest(testedBinder: Symbol, expectedTp: Type) = True // TODO OuterEqProp(testedBinder, expectedType) def typeTest(b: Symbol, pt: Type) = { // a type test implies the tested path is non-null (null.isInstanceOf[T] is false for all T) val p = binderToUniqueTree(b); And(uniqueNonNullProp(p), uniqueTypeProp(p, uniqueTp(pt))) } @@ -711,9 +710,8 @@ trait MatchAnalysis extends MatchApproximation { val (equal, notEqual) = varAssignment.getOrElse(variable, Nil -> Nil) - def addVarAssignment(equalTo: List[Const], notEqualTo: List[Const]) = { - Map(variable ->(equal ++ equalTo, notEqual ++ notEqualTo)) - } + def addVarAssignment(equalTo: List[Const], notEqualTo: List[Const]) = + Map(variable ->((equal ++ equalTo, notEqual ++ notEqualTo))) // this assignment is needed in case that // there exists already an assign @@ -738,7 +736,7 @@ trait MatchAnalysis extends MatchApproximation { if (expanded.isEmpty) { List(varAssignment) } else { - // we need the cartesian product here, + // we need the Cartesian product here, // since we want to report all missing cases // (i.e., combinations) val cartesianProd = expanded.reduceLeft((xs, ys) => diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchCodeGen.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchCodeGen.scala index 1642613b9b..03d0a28fb1 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchCodeGen.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchCodeGen.scala @@ -6,9 +6,9 @@ package scala.tools.nsc.transform.patmat -import scala.tools.nsc.symtab.Flags.SYNTHETIC import scala.language.postfixOps -import scala.reflect.internal.util.Statistics + +import scala.tools.nsc.symtab.Flags.SYNTHETIC import scala.reflect.internal.util.Position /** Factory methods used by TreeMakers to make the actual trees. @@ -55,7 +55,15 @@ trait MatchCodeGen extends Interface { def flatMap(prev: Tree, b: Symbol, next: Tree): Tree def flatMapCond(cond: Tree, res: Tree, nextBinder: Symbol, next: Tree): Tree def flatMapGuard(cond: Tree, next: Tree): Tree - def ifThenElseZero(c: Tree, thenp: Tree): Tree = IF (c) THEN thenp ELSE zero + def ifThenElseZero(c: Tree, thenp: Tree): Tree = { + val z = zero + thenp match { + case If(c1, thenp1, elsep1) if z equalsStructure elsep1 => + If(c AND c1, thenp1, elsep1) // cleaner, leaner trees + case _ => + If(c, thenp, zero) + } + } protected def zero: Tree } diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchOptimization.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchOptimization.scala index f827043094..dc0a457be7 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchOptimization.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchOptimization.scala @@ -6,10 +6,10 @@ package scala.tools.nsc.transform.patmat -import scala.tools.nsc.symtab.Flags.MUTABLE import scala.language.postfixOps + +import scala.tools.nsc.symtab.Flags.MUTABLE import scala.collection.mutable -import scala.reflect.internal.util.Statistics import scala.reflect.internal.util.Position /** Optimize and analyze matches based on their TreeMaker-representation. diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala index bf3bc6b26e..39971590c7 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala @@ -7,7 +7,7 @@ package scala.tools.nsc.transform.patmat import scala.language.postfixOps -import scala.collection.mutable + import scala.reflect.internal.util.Statistics /** Translate typed Trees that represent pattern matches into the patternmatching IR, defined by TreeMakers. @@ -18,8 +18,7 @@ trait MatchTranslation { import PatternMatchingStats._ import global._ import definitions._ - import global.analyzer.{ErrorUtils, formalTypes} - import treeInfo.{ WildcardStarArg, Unapplied, isStar, unbind } + import treeInfo.{ Unapplied, unbind } import CODE._ // Always map repeated params to sequences @@ -117,7 +116,7 @@ trait MatchTranslation { val makers = { val paramType = extractor.aligner.wholeType // Statically conforms to paramType - if (this ensureConformsTo paramType) treeMaker(binder, false, pos) :: Nil + if (tpe <:< paramType) treeMaker(binder, false, pos) :: Nil else { // chain a type-testing extractor before the actual extractor call // it tests the type, checks the outer pointer and casts to the expected type @@ -167,16 +166,6 @@ trait MatchTranslation { setVarInfo(binder, paramType) true } - // If <:< but not =:=, no type test needed, but the tree maker relies on the binder having - // exactly paramType (and not just some type compatible with it.) SI-6624 shows this is necessary - // because apparently patBinder may have an unfortunate type (.decls don't have the case field - // accessors) TODO: get to the bottom of this -- I assume it happens when type checking - // infers a weird type for an unapply call. By going back to the parameterType for the - // extractor call we get a saner type, so let's just do that for now. - def ensureConformsTo(paramType: Type): Boolean = ( - (tpe =:= paramType) - || (tpe <:< paramType) && setInfo(paramType) - ) private def concreteType = tpe.bounds.hi private def unbound = unbind(tree) @@ -401,7 +390,6 @@ trait MatchTranslation { /** Create the TreeMaker that embodies this extractor call * - * `binder` has been casted to `paramType` if necessary * `binderKnownNonNull` indicates whether the cast implies `binder` cannot be null * when `binderKnownNonNull` is `true`, `ProductExtractorTreeMaker` does not do a (redundant) null check on binder */ @@ -507,7 +495,7 @@ trait MatchTranslation { * when `binderKnownNonNull` is `true`, `ProductExtractorTreeMaker` does not do a (redundant) null check on binder */ def treeMaker(binder: Symbol, binderKnownNonNull: Boolean, pos: Position): TreeMaker = { - val paramAccessors = binder.constrParamAccessors + val paramAccessors = aligner.wholeType.typeSymbol.constrParamAccessors val numParams = paramAccessors.length def paramAccessorAt(subPatIndex: Int) = paramAccessors(math.min(subPatIndex, numParams - 1)) // binders corresponding to mutable fields should be stored (SI-5158, SI-6070) @@ -536,7 +524,7 @@ trait MatchTranslation { // reference the (i-1)th case accessor if it exists, otherwise the (i-1)th tuple component override protected def tupleSel(binder: Symbol)(i: Int): Tree = { - val accessors = binder.caseFieldAccessors + val accessors = aligner.wholeType.typeSymbol.caseFieldAccessors if (accessors isDefinedAt (i-1)) gen.mkAttributedStableRef(binder) DOT accessors(i-1) else codegen.tupleSel(binder)(i) // this won't type check for case classes, as they do not inherit ProductN } diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchTreeMaking.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchTreeMaking.scala index 3ace61411f..794d3d442a 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchTreeMaking.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchTreeMaking.scala @@ -6,10 +6,10 @@ package scala.tools.nsc.transform.patmat -import scala.tools.nsc.symtab.Flags.{SYNTHETIC, ARTIFACT} import scala.language.postfixOps + +import scala.tools.nsc.symtab.Flags.{SYNTHETIC, ARTIFACT} import scala.collection.mutable -import scala.reflect.internal.util.Statistics import scala.reflect.internal.util.Position /** Translate our IR (TreeMakers) into actual Scala Trees using the factory methods in MatchCodeGen. @@ -101,7 +101,7 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { case class SubstOnlyTreeMaker(prevBinder: Symbol, nextBinder: Symbol) extends TreeMaker { val pos = NoPosition - val localSubstitution = Substitution(prevBinder, CODE.REF(nextBinder)) + val localSubstitution = Substitution(prevBinder, gen.mkAttributedStableRef(nextBinder)) def chainBefore(next: Tree)(casegen: Casegen): Tree = substitution(next) override def toString = "S"+ localSubstitution } @@ -118,7 +118,7 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { val res: Tree lazy val nextBinder = freshSym(pos, nextBinderTp) - lazy val localSubstitution = Substitution(List(prevBinder), List(CODE.REF(nextBinder))) + lazy val localSubstitution = Substitution(List(prevBinder), List(gen.mkAttributedStableRef(nextBinder))) def chainBefore(next: Tree)(casegen: Casegen): Tree = atPos(pos)(casegen.flatMapCond(cond, res, nextBinder, substitution(next))) @@ -316,7 +316,7 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { trait TypeTestCondStrategy { type Result - def outerTest(testedBinder: Symbol, expectedTp: Type): Result + def withOuterTest(orig: Result)(testedBinder: Symbol, expectedTp: Type): Result = orig // TODO: can probably always widen def typeTest(testedBinder: Symbol, expectedTp: Type): Result def nonNullTest(testedBinder: Symbol): Result @@ -336,15 +336,34 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { def equalsTest(pat: Tree, testedBinder: Symbol) = codegen._equals(pat, testedBinder) def eqTest(pat: Tree, testedBinder: Symbol) = REF(testedBinder) OBJ_EQ pat - def outerTest(testedBinder: Symbol, expectedTp: Type): Tree = { + override def withOuterTest(orig: Tree)(testedBinder: Symbol, expectedTp: Type): Tree = { val expectedPrefix = expectedTp.prefix - if (expectedPrefix eq NoType) mkTRUE // fallback for SI-6183 - else { - // ExplicitOuter replaces `Select(q, outerSym) OBJ_EQ expectedPrefix` by `Select(q, outerAccessor(outerSym.owner)) OBJ_EQ expectedPrefix` - // if there's an outer accessor, otherwise the condition becomes `true` -- TODO: can we improve needsOuterTest so there's always an outerAccessor? - val outerFor = expectedTp.typeSymbol - val outerMarker = outerFor.newMethod(vpmName.outer, newFlags = SYNTHETIC | ARTIFACT) setInfo expectedPrefix - Select(codegen._asInstanceOf(testedBinder, expectedTp), outerMarker) OBJ_EQ gen.mkAttributedQualifier(expectedPrefix) + val testedPrefix = testedBinder.info.prefix + + // Check if a type is defined in a static location. Unlike `tp.isStatic` before `flatten`, + // this also includes methods and (possibly nested) objects inside of methods. + def definedInStaticLocation(tp: Type): Boolean = { + def isStatic(tp: Type): Boolean = + if (tp == NoType || tp.typeSymbol.isPackageClass || tp == NoPrefix) true + else if (tp.typeSymbol.isModuleClass) isStatic(tp.prefix) + else false + tp.typeSymbol.owner == tp.prefix.typeSymbol && isStatic(tp.prefix) + } + + if ((expectedPrefix eq NoPrefix) + || expectedTp.typeSymbol.isJava + || definedInStaticLocation(expectedTp) + || testedPrefix =:= expectedPrefix) orig + else gen.mkAttributedQualifierIfPossible(expectedPrefix) match { + case None => orig + case Some(expectedOuterRef) => + // ExplicitOuter replaces `Select(q, outerSym) OBJ_EQ expectedPrefix` + // by `Select(q, outerAccessor(outerSym.owner)) OBJ_EQ expectedPrefix` + // if there's an outer accessor, otherwise the condition becomes `true` + // TODO: centralize logic whether there's an outer accessor and use here? + val synthOuterGetter = expectedTp.typeSymbol.newMethod(vpmName.outer, newFlags = SYNTHETIC | ARTIFACT) setInfo expectedPrefix + val outerTest = (Select(codegen._asInstanceOf(testedBinder, expectedTp), synthOuterGetter)) OBJ_EQ expectedOuterRef + and(orig, outerTest) } } } @@ -354,7 +373,6 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { def typeTest(testedBinder: Symbol, expectedTp: Type): Result = true - def outerTest(testedBinder: Symbol, expectedTp: Type): Result = false def nonNullTest(testedBinder: Symbol): Result = false def equalsTest(pat: Tree, testedBinder: Symbol): Result = false def eqTest(pat: Tree, testedBinder: Symbol): Result = false @@ -366,7 +384,6 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { type Result = Boolean def typeTest(testedBinder: Symbol, expectedTp: Type): Result = testedBinder eq binder - def outerTest(testedBinder: Symbol, expectedTp: Type): Result = false def nonNullTest(testedBinder: Symbol): Result = testedBinder eq binder def equalsTest(pat: Tree, testedBinder: Symbol): Result = false // could in principle analyse pat and see if it's statically known to be non-null def eqTest(pat: Tree, testedBinder: Symbol): Result = false // could in principle analyse pat and see if it's statically known to be non-null @@ -403,12 +420,6 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { import TypeTestTreeMaker._ debug.patmat("TTTM"+((prevBinder, extractorArgTypeTest, testedBinder, expectedTp, nextBinderTp))) - lazy val outerTestNeeded = ( - (expectedTp.prefix ne NoPrefix) - && !expectedTp.prefix.typeSymbol.isPackageClass - && needsOuterTest(expectedTp, testedBinder.info, matchOwner) - ) - // the logic to generate the run-time test that follows from the fact that // a `prevBinder` is expected to have type `expectedTp` // the actual tree-generation logic is factored out, since the analyses generate Cond(ition)s rather than Trees @@ -427,12 +438,11 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { def isExpectedPrimitiveType = isAsExpected && isPrimitiveValueType(expectedTp) def isExpectedReferenceType = isAsExpected && (expectedTp <:< AnyRefTpe) def mkNullTest = nonNullTest(testedBinder) - def mkOuterTest = outerTest(testedBinder, expectedTp) def mkTypeTest = typeTest(testedBinder, expectedWide) def mkEqualsTest(lhs: Tree): cs.Result = equalsTest(lhs, testedBinder) def mkEqTest(lhs: Tree): cs.Result = eqTest(lhs, testedBinder) - def addOuterTest(res: cs.Result): cs.Result = if (outerTestNeeded) and(res, mkOuterTest) else res + def addOuterTest(res: cs.Result): cs.Result = withOuterTest(res)(testedBinder, expectedTp) // If we conform to expected primitive type: // it cannot be null and cannot have an outer pointer. No further checking. @@ -483,7 +493,7 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { // NOTE: generate `patTree == patBinder`, since the extractor must be in control of the equals method (also, patBinder may be null) // equals need not be well-behaved, so don't intersect with pattern's (stabilized) type (unlike MaybeBoundTyped's accumType, where it's required) val cond = codegen._equals(patTree, prevBinder) - val res = CODE.REF(prevBinder) + val res = gen.mkAttributedStableRef(prevBinder) override def toString = "ET"+((prevBinder.name, patTree)) } @@ -554,11 +564,11 @@ trait MatchTreeMaking extends MatchCodeGen with Debugging { else scrut match { case Typed(tree, tpt) => val suppressExhaustive = tpt.tpe hasAnnotation UncheckedClass - val supressUnreachable = tree match { + val suppressUnreachable = tree match { case Ident(name) if name startsWith nme.CHECK_IF_REFUTABLE_STRING => true // SI-7183 don't warn for withFilter's that turn out to be irrefutable. case _ => false } - val suppression = Suppression(suppressExhaustive, supressUnreachable) + val suppression = Suppression(suppressExhaustive, suppressUnreachable) val hasSwitchAnnotation = treeInfo.isSwitchAnnotation(tpt.tpe) // matches with two or fewer cases need not apply for switchiness (if-then-else will do) // `case 1 | 2` is considered as two cases. diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchWarnings.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchWarnings.scala index 8beb1837ad..3f27d18e64 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchWarnings.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchWarnings.scala @@ -6,10 +6,6 @@ package scala.tools.nsc.transform.patmat -import scala.language.postfixOps -import scala.collection.mutable -import scala.reflect.internal.util.Statistics - trait MatchWarnings { self: PatternMatching => @@ -83,4 +79,4 @@ trait MatchWarnings { } } } -}
\ No newline at end of file +} diff --git a/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala b/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala index b2f2516b5b..05f2d60be1 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/PatternMatching.scala @@ -222,7 +222,7 @@ trait Interface extends ast.TreeDSL { object substIdentsForTrees extends Transformer { private def typedIfOrigTyped(to: Tree, origTp: Type): Tree = if (origTp == null || origTp == NoType) to - // important: only type when actually substing and when original tree was typed + // important: only type when actually substituting and when original tree was typed // (don't need to use origTp as the expected type, though, and can't always do this anyway due to unknown type params stemming from polymorphic extractors) else typer.typed(to) diff --git a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala index d4f44303bb..2c1fb064cc 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala @@ -148,7 +148,7 @@ trait ScalacPatternExpanders { val tupled = extractor.asSinglePattern if (effectivePatternArity(args) == 1 && isTupleType(extractor.typeOfSinglePattern)) { val sym = sel.symbol.owner - currentRun.reporting.deprecationWarning(sel.pos, sym, s"${sym} expects $productArity patterns$acceptMessage but crushing into $productArity-tuple to fit single pattern (SI-6675)") + currentRun.reporting.deprecationWarning(sel.pos, sym, s"${sym} expects $productArity patterns$acceptMessage but crushing into $productArity-tuple to fit single pattern (SI-6675)", "2.11.0") } tupled } else extractor |