diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/transform/Erasure.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/Erasure.scala | 197 |
1 files changed, 144 insertions, 53 deletions
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) } |