diff options
Diffstat (limited to 'src/compiler')
27 files changed, 973 insertions, 1194 deletions
diff --git a/src/compiler/scala/reflect/macros/contexts/Typers.scala b/src/compiler/scala/reflect/macros/contexts/Typers.scala index 28c1e3ddb3..baf066c7d9 100644 --- a/src/compiler/scala/reflect/macros/contexts/Typers.scala +++ b/src/compiler/scala/reflect/macros/contexts/Typers.scala @@ -18,22 +18,25 @@ trait Typers { * @see [[scala.tools.reflect.ToolBox.typeCheck]] */ def typecheck(tree: Tree, mode: TypecheckMode = TERMmode, pt: Type = universe.WildcardType, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): Tree = { - macroLogVerbose("typechecking %s with expected type %s, implicit views = %s, macros = %s".format(tree, pt, !withImplicitViewsDisabled, !withMacrosDisabled)) - val context = callsiteTyper.context - val withImplicitFlag = if (!withImplicitViewsDisabled) (context.withImplicitsEnabled[Tree] _) else (context.withImplicitsDisabled[Tree] _) - val withMacroFlag = if (!withMacrosDisabled) (context.withMacrosEnabled[Tree] _) else (context.withMacrosDisabled[Tree] _) - def withContext(tree: => Tree) = withImplicitFlag(withMacroFlag(tree)) - def withWrapping(tree: Tree)(op: Tree => Tree) = if (mode == TERMmode) universe.wrappingIntoTerm(tree)(op) else op(tree) - def typecheckInternal(tree: Tree) = callsiteTyper.silent(_.typed(universe.duplicateAndKeepPositions(tree), mode, pt), reportAmbiguousErrors = false) - withWrapping(tree)(wrappedTree => withContext(typecheckInternal(wrappedTree) match { - case universe.analyzer.SilentResultValue(result) => - macroLogVerbose(result) - result - case error @ universe.analyzer.SilentTypeError(_) => - macroLogVerbose(error.err.errMsg) - if (!silent) throw new TypecheckException(error.err.errPos, error.err.errMsg) - universe.EmptyTree - })) + macroLogVerbose(s"typechecking $tree with expected type $pt, implicit views = ${!withImplicitViewsDisabled}, macros = ${!withMacrosDisabled}") + import callsiteTyper.context + def doTypecheck(wrapped: Tree): Tree = + context.withImplicits(enabled = !withImplicitViewsDisabled) { + context.withMacros(enabled = !withMacrosDisabled) { + callsiteTyper.silent(_.typed(universe.duplicateAndKeepPositions(wrapped), mode, pt), reportAmbiguousErrors = false) match { + case universe.analyzer.SilentResultValue(result) => + macroLogVerbose(result) + result + case error@universe.analyzer.SilentTypeError(_) => + macroLogVerbose(error.err.errMsg) + if (!silent) throw new TypecheckException(error.err.errPos, error.err.errMsg) + universe.EmptyTree + } + } + } + + if (mode == TERMmode) universe.wrappingIntoTerm(tree)(doTypecheck) + else doTypecheck(tree) } def inferImplicitValue(pt: Type, silent: Boolean = true, withMacrosDisabled: Boolean = false, pos: Position = enclosingPosition): Tree = { diff --git a/src/compiler/scala/reflect/reify/codegen/GenTypes.scala b/src/compiler/scala/reflect/reify/codegen/GenTypes.scala index d007df75e3..b2948f8161 100644 --- a/src/compiler/scala/reflect/reify/codegen/GenTypes.scala +++ b/src/compiler/scala/reflect/reify/codegen/GenTypes.scala @@ -106,14 +106,10 @@ trait GenTypes { private def spliceAsManifest(tpe: Type): Tree = { def isSynthetic(manifest: Tree) = manifest exists (sub => sub.symbol != null && (sub.symbol == FullManifestModule || sub.symbol.owner == FullManifestModule)) def searchForManifest(typer: analyzer.Typer): Tree = - analyzer.inferImplicit( - EmptyTree, + analyzer.inferImplicitByTypeSilent( appliedType(FullManifestClass.toTypeConstructor, List(tpe)), - reportAmbiguous = false, - isView = false, - context = typer.context, - saveAmbiguousDivergent = false, - pos = defaultErrorPosition) match { + typer.context, + defaultErrorPosition) match { case success if !success.tree.isEmpty && !isSynthetic(success.tree) => val manifestInScope = success.tree // todo. write a test for this diff --git a/src/compiler/scala/tools/nsc/ast/TreeGen.scala b/src/compiler/scala/tools/nsc/ast/TreeGen.scala index 7edac76b91..0786ceb7c2 100644 --- a/src/compiler/scala/tools/nsc/ast/TreeGen.scala +++ b/src/compiler/scala/tools/nsc/ast/TreeGen.scala @@ -261,43 +261,77 @@ abstract class TreeGen extends scala.reflect.internal.TreeGen with TreeDSL { mkNew(Nil, noSelfType, stats1, NoPosition, NoPosition) } - /** - * Create a method based on a Function - * - * Used both to under `-Ydelambdafy:method` create a lifted function and - * under `-Ydelambdafy:inline` to create the apply method on the anonymous - * class. - * - * It creates a method definition with value params cloned from the - * original lambda. Then it calls a supplied function to create - * the body and types the result. Finally - * everything is wrapped up in a DefDef - * - * @param owner The owner for the new method - * @param name name for the new method - * @param additionalFlags flags to be put on the method in addition to FINAL - */ - def mkMethodFromFunction(localTyper: analyzer.Typer) - (fun: Function, owner: Symbol, name: TermName, additionalFlags: FlagSet = NoFlags) = { - val funParams = fun.vparams map (_.symbol) - val formals :+ restpe = fun.tpe.typeArgs + // Construct a method to implement `fun`'s single abstract method (`apply`, when `fun.tpe` is a built-in function type) + def mkMethodFromFunction(localTyper: analyzer.Typer)(owner: Symbol, fun: Function) = { + // TODO: treat FunctionN like any other SAM -- drop `&& !isFunctionType(fun.tpe)` + val sam = if (!isFunctionType(fun.tpe)) samOf(fun.tpe) else NoSymbol + if (!sam.exists) mkMethodForFunctionBody(localTyper)(owner, fun, nme.apply)() + else { + val samMethType = fun.tpe memberInfo sam + mkMethodForFunctionBody(localTyper)(owner, fun, sam.name.toTermName)(methParamProtos = samMethType.params, resTp = samMethType.resultType) + } + } + + // used to create the lifted method that holds a function's body + def mkLiftedFunctionBodyMethod(localTyper: analyzer.Typer)(owner: Symbol, fun: Function) = + mkMethodForFunctionBody(localTyper)(owner, fun, nme.ANON_FUN_NAME)(additionalFlags = ARTIFACT) + + + /** + * Lift a Function's body to a method. For use during Uncurry, where Function nodes have type FunctionN[T1, ..., Tn, R] + * + * It creates a method definition with value params derived from the original lambda + * or `methParamProtos` (used to create the correct override for sam methods). + * + * Replace the `fun.vparams` symbols by the newly created method params, + * changes owner of `fun.body` from `fun.symbol` to resulting method's symbol. + * + * @param owner The owner for the new method + * @param fun the function to take the body from + * @param name name for the new method + * @param additionalFlags flags to be put on the method in addition to FINAL + */ + private def mkMethodForFunctionBody(localTyper: analyzer.Typer) + (owner: Symbol, fun: Function, name: TermName) + (methParamProtos: List[Symbol] = fun.vparams.map(_.symbol), + resTp: Type = functionResultType(fun.tpe), + additionalFlags: FlagSet = NoFlags): DefDef = { val methSym = owner.newMethod(name, fun.pos, FINAL | additionalFlags) + // for sams, methParamProtos is the parameter symbols for the sam's method, so that we generate the correct override (based on parmeter types) + val methParamSyms = methParamProtos.map { param => methSym.newSyntheticValueParam(param.tpe, param.name.toTermName) } + methSym setInfo MethodType(methParamSyms, resTp) - val paramSyms = map2(formals, fun.vparams) { - (tp, vparam) => methSym.newSyntheticValueParam(tp, vparam.name) - } + // we must rewire reference to the function's param symbols -- and not methParamProtos -- to methParamSyms + val useMethodParams = new TreeSymSubstituter(fun.vparams.map(_.symbol), methParamSyms) + // we're now owned by the method that holds the body, and not the function + val moveToMethod = new ChangeOwnerTraverser(fun.symbol, methSym) - methSym setInfo MethodType(paramSyms, restpe.deconst) + newDefDef(methSym, moveToMethod(useMethodParams(fun.body)))(tpt = TypeTree(resTp)) + } + + // TODO: the rewrite to AbstractFunction is superfluous once we compile FunctionN to a SAM type (aka functional interface) + def functionClassType(fun: Function): Type = + if (isFunctionType(fun.tpe)) abstractFunctionType(fun.vparams.map(_.symbol.tpe), fun.body.tpe.deconst) + else fun.tpe - fun.body.substituteSymbols(funParams, paramSyms) - fun.body changeOwner (fun.symbol -> methSym) + def expandFunction(localTyper: analyzer.Typer)(fun: Function, inConstructorFlag: Long): Tree = { + val parents = addSerializable(functionClassType(fun)) + val anonClass = fun.symbol.owner newAnonymousFunctionClass(fun.pos, inConstructorFlag) addAnnotation SerialVersionUIDAnnotation - val methDef = DefDef(methSym, fun.body) + // 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) - // Have to repack the type to avoid mismatches when existentials - // appear in the result - see SI-4869. - methDef.tpt setType localTyper.packedType(fun.body, methSym).deconst - methDef + val samDef = mkMethodFromFunction(localTyper)(anonClass, fun) + anonClass.info.decls enter samDef.symbol + + localTyper.typedPos(fun.pos) { + Block( + ClassDef(anonClass, NoMods, ListOfNil, List(samDef), fun.pos), + Typed(New(anonClass.tpe), TypeTree(fun.tpe))) + } } } diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala index d4715471f6..9c0174d89b 100644 --- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala +++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala @@ -1713,9 +1713,7 @@ self => } simpleExprRest(app, canApply = true) case USCORE => - atPos(t.pos.start, in.skipToken()) { - Typed(stripParens(t), Function(Nil, EmptyTree)) - } + atPos(t.pos.start, in.skipToken()) { makeMethodValue(stripParens(t)) } case _ => t } diff --git a/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala b/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala index 473a40f42a..1e9a1762eb 100644 --- a/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala +++ b/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala @@ -35,6 +35,9 @@ abstract class TreeBuilder { def repeatedApplication(tpe: Tree): Tree = AppliedTypeTree(rootScalaDot(tpnme.REPEATED_PARAM_CLASS_NAME), List(tpe)) + // represents `expr _`, as specified in Method Values of spec/06-expressions.md + def makeMethodValue(expr: Tree): Tree = Typed(expr, Function(Nil, EmptyTree)) + def makeImportSelector(name: Name, nameOffset: Int): ImportSelector = ImportSelector(name, nameOffset, name, nameOffset) diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala index c17f3c0b5f..a4d08cb123 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala @@ -638,8 +638,8 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder { } argsSize match { case 1 => bc newarray elemKind - case _ => - val descr = ('[' * argsSize) + elemKind.descriptor // denotes the same as: arrayN(elemKind, argsSize).descriptor + case _ => // this is currently dead code is Scalac, unlike in Dotty + val descr = ("[" * argsSize) + elemKind.descriptor // denotes the same as: arrayN(elemKind, argsSize).descriptor mnode.visitMultiANewArrayInsn(descr, argsSize) } @@ -656,7 +656,7 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder { case Apply(fun, args) if app.hasAttachment[delambdafy.LambdaMetaFactoryCapable] => val attachment = app.attachments.get[delambdafy.LambdaMetaFactoryCapable].get genLoadArguments(args, paramTKs(app)) - genInvokeDynamicLambda(attachment.target, attachment.arity, attachment.functionalInterface) + genInvokeDynamicLambda(attachment.target, attachment.arity, attachment.functionalInterface, attachment.sam) generatedType = methodBTypeFromSymbol(fun.symbol).returnType case Apply(fun @ _, List(expr)) if currentRun.runDefinitions.isBox(fun.symbol) => @@ -1357,7 +1357,7 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder { def genSynchronized(tree: Apply, expectedType: BType): BType def genLoadTry(tree: Try): BType - def genInvokeDynamicLambda(lambdaTarget: Symbol, arity: Int, functionalInterface: Symbol) { + def genInvokeDynamicLambda(lambdaTarget: Symbol, arity: Int, functionalInterface: Symbol, sam: Symbol) { val isStaticMethod = lambdaTarget.hasFlag(Flags.STATIC) def asmType(sym: Symbol) = classBTypeFromSymbol(sym).toASMType @@ -1372,7 +1372,6 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder { val invokedType = asm.Type.getMethodDescriptor(asmType(functionalInterface), (receiver ::: capturedParams).map(sym => typeToBType(sym.info).toASMType): _*) val constrainedType = new MethodBType(lambdaParams.map(p => typeToBType(p.tpe)), typeToBType(lambdaTarget.tpe.resultType)).toASMType - val sam = functionalInterface.info.decls.find(_.isDeferred).getOrElse(functionalInterface.info.member(nme.apply)) val samName = sam.name.toString val samMethodType = methodBTypeFromSymbol(sam).toASMType diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala index 03ac006517..a2ccce9d21 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala @@ -61,6 +61,8 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters { assert(classSym.isClass, s"not a class: $classSym") val r = exitingPickler(classSym.isAnonymousClass) || !classSym.originalOwner.isClass if (r) { + // lambda lift renames symbols and may accidentally introduce `$lambda` into a class name, making `isDelambdafyFunction` true. + // we prevent this, see `nonAnon` in LambdaLift. // phase travel necessary: after flatten, the name includes the name of outer classes. // if some outer name contains $lambda, a non-lambda class is considered lambda. assert(exitingPickler(!classSym.isDelambdafyFunction), classSym.name) @@ -260,7 +262,7 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters { else { // Phase travel necessary. For example, nullary methods (getter of an abstract val) get an // empty parameter list in later phases and would therefore be picked as SAM. - val samSym = exitingPickler(definitions.findSam(classSym.tpe)) + val samSym = exitingPickler(definitions.samOf(classSym.tpe)) if (samSym == NoSymbol) None else Some(samSym.javaSimpleName.toString + methodSymToDescriptor(samSym)) } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala index 696a164c56..ab9fd94a93 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala @@ -219,14 +219,12 @@ class CoreBTypes[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) { // enumeration of specialized classes is temporary, while we still use the java-defined JFunctionN. // once we switch to ordinary FunctionN, we can use specializedSubclasses just like for tuples. - private def functionClasses(base: String): Set[Symbol] = { - def primitives = Iterator("B", "S", "I", "J", "C", "F", "D", "Z", "V") + private def specializedJFunctionSymbols(base: String): Seq[Symbol] = { + def primitives = Seq("B", "S", "I", "J", "C", "F", "D", "Z", "V") def ijfd = Iterator("I", "J", "F", "D") def ijfdzv = Iterator("I", "J", "F", "D", "Z", "V") def ijd = Iterator("I", "J", "D") - val classNames = Set.empty[String] ++ { - (0 to 22).map(base + _) - } ++ { + val classNames = { primitives.map(base + "0$mc" + _ + "$sp") // Function0 } ++ { // return type specializations appear first in the name string (alphabetical sorting) @@ -237,7 +235,7 @@ class CoreBTypes[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) { classNames map getRequiredClass } - lazy val srJFunctionRefs: Set[InternalName] = functionClasses("scala.runtime.java8.JFunction").map(classBTypeFromSymbol(_).internalName) + lazy val functionRefs: Set[InternalName] = (FunctionClass.seq ++ specializedJFunctionSymbols("scala.runtime.java8.JFunction")).map(classBTypeFromSymbol(_).internalName).toSet lazy val typeOfArrayOp: Map[Int, BType] = { import scalaPrimitives._ @@ -343,7 +341,7 @@ trait CoreBTypesProxyGlobalIndependent[BTS <: BTypes] { def srRefConstructors : Map[InternalName, MethodNameAndType] def tupleClassConstructors : Map[InternalName, MethodNameAndType] - def srJFunctionRefs: Set[InternalName] + def functionRefs: Set[InternalName] def lambdaMetaFactoryBootstrapHandle : asm.Handle def lambdaDeserializeBootstrapHandle : asm.Handle @@ -410,7 +408,7 @@ final class CoreBTypesProxy[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: def srRefConstructors : Map[InternalName, MethodNameAndType] = _coreBTypes.srRefConstructors def tupleClassConstructors : Map[InternalName, MethodNameAndType] = _coreBTypes.tupleClassConstructors - def srJFunctionRefs: Set[InternalName] = _coreBTypes.srJFunctionRefs + def functionRefs: Set[InternalName] = _coreBTypes.functionRefs def srSymbolLiteral : ClassBType = _coreBTypes.srSymbolLiteral def srStructuralCallSite : ClassBType = _coreBTypes.srStructuralCallSite diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala index bd7d5d2608..a6b9faa933 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala @@ -125,7 +125,7 @@ class BackendUtils[BT <: BTypes](val btypes: BT) { private val anonfunAdaptedName = """.*\$anonfun\$\d+\$adapted""".r def hasAdaptedImplMethod(closureInit: ClosureInstantiation): Boolean = { - isrJFunctionType(Type.getReturnType(closureInit.lambdaMetaFactoryCall.indy.desc).getInternalName) && + isBuiltinFunctionType(Type.getReturnType(closureInit.lambdaMetaFactoryCall.indy.desc).getInternalName) && anonfunAdaptedName.pattern.matcher(closureInit.lambdaMetaFactoryCall.implMethod.getName).matches } @@ -250,7 +250,7 @@ class BackendUtils[BT <: BTypes](val btypes: BT) { } } - def isrJFunctionType(internalName: InternalName): Boolean = srJFunctionRefs(internalName) + def isBuiltinFunctionType(internalName: InternalName): Boolean = functionRefs(internalName) /** * Visit the class node and collect all referenced nested classes. diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala index 9a90c53d3e..f48f60a438 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala @@ -88,6 +88,11 @@ object BytecodeUtils { def isLoadOrStore(instruction: AbstractInsnNode): Boolean = isLoad(instruction) || isStore(instruction) + def isNonVirtualCall(instruction: AbstractInsnNode): Boolean = { + val op = instruction.getOpcode + op == INVOKESPECIAL || op == INVOKESTATIC + } + def isExecutable(instruction: AbstractInsnNode): Boolean = instruction.getOpcode >= 0 def isConstructor(methodNode: MethodNode): Boolean = { diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala index 6dd74bad84..3267b9b5df 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala @@ -132,7 +132,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { (declarationClassNode, source) <- byteCodeRepository.classNodeAndSource(declarationClass): Either[OptimizerWarning, (ClassNode, Source)] } yield { val declarationClassBType = classBTypeFromClassNode(declarationClassNode) - val CallsiteInfo(safeToInline, safeToRewrite, canInlineFromSource, annotatedInline, annotatedNoInline, samParamTypes, warning) = analyzeCallsite(method, declarationClassBType, call.owner, source) + val CallsiteInfo(safeToInline, safeToRewrite, canInlineFromSource, annotatedInline, annotatedNoInline, samParamTypes, warning) = analyzeCallsite(method, declarationClassBType, call, source) Callee( callee = method, calleeDeclarationClass = declarationClassBType, @@ -264,7 +264,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { /** * Analyze a callsite and gather meta-data that can be used for inlining decisions. */ - private def analyzeCallsite(calleeMethodNode: MethodNode, calleeDeclarationClassBType: ClassBType, receiverTypeInternalName: InternalName, calleeSource: Source): CallsiteInfo = { + private def analyzeCallsite(calleeMethodNode: MethodNode, calleeDeclarationClassBType: ClassBType, call: MethodInsnNode, calleeSource: Source): CallsiteInfo = { val methodSignature = calleeMethodNode.name + calleeMethodNode.desc try { @@ -277,7 +277,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { val isAbstract = BytecodeUtils.isAbstractMethod(calleeMethodNode) - val receiverType = classBTypeFromParsedClassfile(receiverTypeInternalName) + val receiverType = classBTypeFromParsedClassfile(call.owner) // (1) A non-final method can be safe to inline if the receiver type is a final subclass. Example: // class A { @inline def f = 1 }; object B extends A; B.f // can be inlined // @@ -295,6 +295,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // TODO: type analysis can render more calls statically resolved. Example: // new A.f // can be inlined, the receiver type is known to be exactly A. val isStaticallyResolved: Boolean = { + isNonVirtualCall(call) || // SD-86: super calls (invokespecial) can be inlined methodInlineInfo.effectivelyFinal || receiverType.info.orThrow.inlineInfo.isEffectivelyFinal // (1) } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/CopyProp.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/CopyProp.scala index f1eaebd27c..d28565b9bc 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CopyProp.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CopyProp.scala @@ -296,11 +296,11 @@ class CopyProp[BT <: BTypes](val btypes: BT) { /** * Eliminate the closure value produced by `indy`. If the SAM type is known to construct - * without side-effects (e.g. scala/runtime/java8/JFunctionN), the `indy` and its inputs + * without side-effects (e.g. scala/FunctionN), the `indy` and its inputs * are eliminated, otherwise a POP is inserted. */ def handleClosureInst(indy: InvokeDynamicInsnNode): Unit = { - if (isrJFunctionType(Type.getReturnType(indy.desc).getInternalName)) { + if (isBuiltinFunctionType(Type.getReturnType(indy.desc).getInternalName)) { toRemove += indy callGraph.removeClosureInstantiation(indy, method) handleInputs(indy, Type.getArgumentTypes(indy.desc).length) diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala index 982a6da41a..e924dc856a 100644 --- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala +++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala @@ -109,7 +109,7 @@ trait ScalaSettings extends AbsScalaSettings val Xmigration = ScalaVersionSetting ("-Xmigration", "version", "Warn about constructs whose behavior may have changed since version.", initial = NoScalaVersion, default = Some(AnyScalaVersion)) val nouescape = BooleanSetting ("-Xno-uescape", "Disable handling of \\u unicode escapes.") val Xnojline = BooleanSetting ("-Xnojline", "Do not use JLine for editing.") - val Xverify = BooleanSetting ("-Xverify", "Verify generic signatures in generated bytecode (asm backend only.)") + val Xverify = BooleanSetting ("-Xverify", "Verify generic signatures in generated bytecode.") val plugin = MultiStringSetting ("-Xplugin", "paths", "Load a plugin from each classpath.") val disable = MultiStringSetting ("-Xplugin-disable", "plugin", "Disable plugins by name.") val showPlugins = BooleanSetting ("-Xplugin-list", "Print a synopsis of loaded plugins.") diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala index 1e479d3f63..636fb08b89 100644 --- a/src/compiler/scala/tools/nsc/transform/Constructors.scala +++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala @@ -501,8 +501,6 @@ 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: * (a) has stationary value, ie the same value provided via the corresponding ctor-arg; and @@ -511,7 +509,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { * (b.2) the constructor in the specialized (sub-)class. * (c) isn't part of a DelayedInit subclass. */ - private def canBeSupplanted(sym: Symbol) = !isDelayedInitSubclass && isStationaryParamRef(sym) && !possiblySpecialized(sym) + private def canBeSupplanted(sym: Symbol) = !isDelayedInitSubclass && isStationaryParamRef(sym) && !specializeTypes.possiblySpecialized(sym) override def transform(tree: Tree): Tree = tree match { case Apply(Select(This(_), _), List()) => @@ -531,7 +529,7 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { gen.mkAttributedIdent(parameter(tree.symbol)) setPos tree.pos case Select(_, _) if guardSpecializedFieldInit => // reasoning behind this guard in the docu of `usesSpecializedField` - if (possiblySpecialized(tree.symbol)) { + if (specializeTypes.possiblySpecialized(tree.symbol)) { usesSpecializedField = true } super.transform(tree) diff --git a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala index 67e3f67f2f..76c84bd428 100644 --- a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala +++ b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala @@ -7,30 +7,19 @@ import scala.collection._ 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 converted 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 GenASM - * - * 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 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._ @@ -40,6 +29,19 @@ 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) + + /** + * 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) @@ -52,432 +54,217 @@ 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 + 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 + 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 (target hasFlag STATIC) captureArgs // no `this` reference needed + else (gen.mkAttributedThis(fun.symbol.enclClass) setPos pos) :: captureArgs + } + // 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)) + } - val typer = localTyper + // We then apply this symbol to the captures. + val apply = localTyper.typedPos(pos)(Apply(Ident(msym), allCapturedArgRefs)) - // 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 + // TODO: this is a bit gross + val sam = samUserDefined orElse { + if (isSpecialized) functionalInterface.info.decls.find(_.isDeferred).get + else functionalInterface.info.member(nme.apply) } - methodReferringMap.keys foreach refersToThis - referrers + + // 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) + + // 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)) + + apply } - // 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) + private def reboxValueClass(tp: Type) = tp match { + case ErasedValueType(valueClazz, _) => TypeRef(NoPrefix, valueClazz, Nil) + case _ => tp } - // 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) + // 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) } - private def optionSymbol(sym: Symbol): Option[Symbol] = if (sym.exists) Some(sym) else None + // 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 correspondance 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 dealin 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. - // turns a lambda into a new class def, a New expression instantiating that class - private def transformFunction(originalFunction: Function): TransformedFunction = { - val formals = originalFunction.vparams.map(_.tpe) - val restpe = originalFunction.body.tpe.deconst - val oldClass = originalFunction.symbol.enclClass + val bridgeParamTypes = map2(samParamTypes, functionParamTypes){ (samParamTp, funParamTp) => + if (isReferenceType(samParamTp) && funParamTp <:< samParamTp) funParamTp + else samParamTp + } - // 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) + val bridgeResultType = + if (resTpOk && isReferenceType(samResultType) && functionResultType <:< samResultType) functionResultType + else samResultType - val target = targetMethod(originalFunction) - target.makeNotPrivate(target.owner) - if (!thisReferringMethods.contains(target)) - target setFlag STATIC + val typeAdapter = new TypeAdapter { def typedPos(pos: Position)(tree: Tree): Tree = localTyper.typedPos(pos)(tree) } + import typeAdapter.{adaptToType, unboxValueClass} - val isStatic = target.hasFlag(STATIC) + val targetParams = target.paramss.head + val numCaptures = targetParams.length - functionParamTypes.length + val (targetCapturedParams, targetFunctionParams) = targetParams.splitAt(numCaptures) - 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) - } + 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) } - 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] - } - } - /** - * 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 - - newClass.info.decls enter methSym - 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. - - 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) + gen.mkMethodCall(Select(gen.mkAttributedThis(oldClass), target), capturedArgRefs ::: functionArgRefs) + } - // 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 - } + val bridge = postErasure.newTransformer(unit).transform(DefDef(methSym, List(bridgeParams.map(ValDef(_))), + adaptToType(forwarderCall setType functionResultType, bridgeResultType))).asInstanceOf[DefDef] - /** - * 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( - atPos(newClass.pos)(Apply(gen.mkSuperInitCall, Nil)) - ) ++ assigns, - Literal(Constant(())): Tree - ) setPos newClass.pos - - (localTyper typed DefDef(constrSym, List(params), body) setPos newClass.pos).asInstanceOf[DefDef] + boxingBridgeMethods += bridge + bridge.symbol } + } - 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)) - } + private def transformFunction(originalFunction: Function): Tree = { + val target = targetMethod(originalFunction) + target.makeNotPrivate(target.owner) - // 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) - } - } + // must be done before calling createBoxingBridgeMethod and mkLambdaMetaFactoryCall + if (!(target hasFlag STATIC) && !methodReferencesThis(target)) target setFlag STATIC - val decapturify = new DeCapturifyTransformer(captureProxies2, unit, oldClass, lambdaClass, originalFunction.symbol.pos, thisProxy) + 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 decapturedFunction = decapturify.transform(originalFunction).asInstanceOf[Function] + val isSpecialized = specializedName != funSym.name + val functionalInterface = // TODO: this is no longer needed, right? we can just use the regular function classes + if (isSpecialized) currentRun.runDefinitions.Scala_Java8_CompatPackage.info.decl(specializedName.prepend("J")) + else FunctionClass(originalFunction.vparams.length) - val members = (optionSymbol(thisProxy).toList ++ (captureProxies2 map (_._2))) map {member => - lambdaClass.info.decls enter member - ValDef(member, gen.mkZero(member.tpe)) setPos decapturedFunction.pos + (functionalInterface, isSpecialized) } - // 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}" - - 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) - } + val sam = originalFunction.attachments.get[SAMFunction].map(_.sam).getOrElse(NoSymbol) + mkLambdaMetaFactoryCall(originalFunction, target, functionalInterface, sam, isSpecialized) } - /** - * 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) - - val methodType = MethodType(bridgeSyms, ObjectTpe) - bridgeMethSym setInfo methodType - - def adapt(tree: Tree, expectedTpe: Type): (Boolean, Tree) = { - if (tree.tpe =:= expectedTpe) (false, tree) - else (true, adaptToType(tree, expectedTpe)) - } - - 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) - } - - 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] - } - 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 - } + // 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(_, _, _) => + 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) } } // DelambdafyTransformer + // 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 @@ -510,40 +297,36 @@ 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 $fun") - } + // recursively find methods that refer to 'this' directly or indirectly via references to other methods + // for each method found add it to the referrers set + private def refersToThis(symbol: Symbol): Boolean = + (thisReferringMethods contains symbol) || + (liftedMethodReferences(symbol) exists refersToThis) && { + // add it early to memoize + debuglog(s"$symbol indirectly refers to 'this'") + thisReferringMethods += symbol + true + } - // 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 => // 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 @@ -559,27 +342,10 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre 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 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")) - } - (functionalInterface, isSpecialized) - } } diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index ba15b01446..ac794201a4 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -578,8 +578,9 @@ 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 @@ -647,7 +648,7 @@ 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) @@ -656,10 +657,9 @@ 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.resultType)) @@ -721,6 +721,12 @@ 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) => @@ -1181,5 +1187,41 @@ 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/LambdaLift.scala b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala index 7a5bd747c4..074acc1332 100644 --- a/src/compiler/scala/tools/nsc/transform/LambdaLift.scala +++ b/src/compiler/scala/tools/nsc/transform/LambdaLift.scala @@ -223,10 +223,6 @@ 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. - def nonAnon(s: String) = nme.ensureNonAnon(s) - def newName(sym: Symbol): Name = { val originalName = sym.name def freshen(prefix: String): Name = @@ -235,7 +231,7 @@ 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?) @@ -243,7 +239,7 @@ abstract class LambdaLift extends InfoTransform { // 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 && calledFromInner(sym)) - newTermNameCached(nonAnon(sym.enclClass.fullName('$')) + nme.EXPAND_SEPARATOR_STRING + name) + newTermNameCached(nme.ensureNonAnon(sym.enclClass.fullName('$')) + nme.EXPAND_SEPARATOR_STRING + name) else name } diff --git a/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala b/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala index 998f0b22cb..0050d08f1b 100644 --- a/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala +++ b/src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala @@ -285,6 +285,19 @@ 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 => diff --git a/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala b/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala index 1ed728247b..afafdedce7 100644 --- a/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala +++ b/src/compiler/scala/tools/nsc/transform/TypeAdaptingTransformer.scala @@ -1,89 +1,64 @@ package scala.tools.nsc package transform +import scala.annotation.tailrec import scala.tools.nsc.ast.TreeDSL /** * 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 private def isSafelyRemovableUnbox(fn: Tree, arg: Tree): Boolean = { currentRun.runDefinitions.isUnbox(fn.symbol) && { val cls = arg.tpe.typeSymbol - (cls == definitions.NullClass) || isBoxedValueClass(cls) + (cls == NullClass) || isBoxedValueClass(cls) } } - private def isPrimitiveValueType(tpe: Type) = isPrimitiveValueClass(tpe.typeSymbol) - - private def isErasedValueType(tpe: Type) = tpe.isInstanceOf[ErasedValueType] + 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 - private def isDifferentErasedValueType(tpe: Type, other: Type) = - isErasedValueType(tpe) && (tpe ne other) - - 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 { + /* 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 + } + } } - 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`. @@ -92,27 +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 => @@ -124,21 +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) { @@ -159,27 +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/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala index 40a988ee94..628090dba5 100644 --- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala +++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala @@ -7,6 +7,7 @@ package scala package tools.nsc package transform +import scala.annotation.tailrec import scala.language.postfixOps import symtab.Flags._ @@ -65,19 +66,30 @@ 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` */ @@ -88,25 +100,17 @@ 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 @@ -115,7 +119,7 @@ abstract class UnCurry extends InfoTransform def isByNameRef(tree: Tree) = ( tree.isTerm && (tree.symbol ne null) - && (isByName(tree.symbol)) + && isByName(tree.symbol) && !byNameArgs(tree) ) @@ -192,16 +196,6 @@ 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 { @@ -210,63 +204,30 @@ 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 canUseDelamdafyMethod = inConstructorFlag == 0 // Avoiding synthesizing code prone to SI-6666, SI-8363 by using old-style lambda translation - 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))) - } - } - } + 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 { + // 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) + )) + val typedNewFun = localTyper.typedPos(fun.pos)(Block(liftedMethod, super.transform(newFun))) + if (mustExpandFunction(fun)) { + 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 @@ -344,25 +305,22 @@ 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) } } } @@ -433,9 +391,10 @@ 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 = ( + val result = if ((sym ne null) && sym.elisionLevel.exists(_ < settings.elidebelow.value)) replaceElidableTree(tree) else translateSynchronized(tree) match { @@ -488,7 +447,7 @@ 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, _) => @@ -507,7 +466,7 @@ 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(_, _) => @@ -527,9 +486,8 @@ 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 { @@ -548,7 +506,7 @@ abstract class UnCurry extends InfoTransform 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) => @@ -620,7 +578,7 @@ 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 diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala index c5a3d605b1..bcc1ed3e64 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala @@ -387,8 +387,10 @@ trait Contexts { self: Analyzer => @inline final def withImplicitsEnabled[T](op: => T): T = withMode(enabled = ImplicitsEnabled)(op) @inline final def withImplicitsDisabled[T](op: => T): T = withMode(disabled = ImplicitsEnabled | EnrichmentEnabled)(op) @inline final def withImplicitsDisabledAllowEnrichment[T](op: => T): T = withMode(enabled = EnrichmentEnabled, disabled = ImplicitsEnabled)(op) + @inline final def withImplicits[T](enabled: Boolean)(op: => T): T = if (enabled) withImplicitsEnabled(op) else withImplicitsDisabled(op) @inline final def withMacrosEnabled[T](op: => T): T = withMode(enabled = MacrosEnabled)(op) @inline final def withMacrosDisabled[T](op: => T): T = withMode(disabled = MacrosEnabled)(op) + @inline final def withMacros[T](enabled: Boolean)(op: => T): T = if (enabled) withMacrosEnabled(op) else withMacrosDisabled(op) @inline final def withinStarPatterns[T](op: => T): T = withMode(enabled = StarPatterns)(op) @inline final def withinSuperInit[T](op: => T): T = withMode(enabled = SuperInit)(op) @inline final def withinSecondTry[T](op: => T): T = withMode(enabled = SecondTry)(op) diff --git a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala index 7092f00bff..97de2b6c85 100644 --- a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala +++ b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala @@ -15,39 +15,29 @@ import symtab.Flags._ * @version 1.0 */ trait EtaExpansion { self: Analyzer => - import global._ - object etaExpansion { - private def isMatch(vparam: ValDef, arg: Tree) = arg match { - case Ident(name) => vparam.name == name - case _ => false - } - - def unapply(tree: Tree): Option[(List[ValDef], Tree, List[Tree])] = tree match { - case Function(vparams, Apply(fn, args)) if (vparams corresponds args)(isMatch) => - Some((vparams, fn, args)) - case _ => - None - } - } - - /** <p> - * Expand partial function applications of type `type`. - * </p><pre> - * p.f(es_1)...(es_n) - * ==> { - * <b>private synthetic val</b> eta$f = p.f // if p is not stable - * ... - * <b>private synthetic val</b> eta$e_i = e_i // if e_i is not stable - * ... - * (ps_1 => ... => ps_m => eta$f([es_1])...([es_m])(ps_1)...(ps_m)) - * }</pre> - * <p> - * tree is already attributed - * </p> - */ - def etaExpand(unit : CompilationUnit, tree: Tree, typer: Typer): Tree = { + /** Expand partial method application `p.f(es_1)...(es_n)`. + * + * We expand this to the following block, which evaluates + * the target of the application and its supplied arguments if needed (they are not stable), + * and then wraps a Function that abstracts over the missing arguments. + * + * ``` + * { + * private synthetic val eta$f = p.f // if p is not stable + * ... + * private synthetic val eta$e_i = e_i // if e_i is not stable + * ... + * (ps_1 => ... => ps_m => eta$f([es_1])...([es_m])(ps_1)...(ps_m)) + * } + * ``` + * + * This is called from instantiateToMethodType after type checking `tree`, + * and we realize we have a method type, where a function type (builtin or SAM) is expected. + * + **/ + def etaExpand(unit: CompilationUnit, tree: Tree, typer: Typer): Tree = { val tpe = tree.tpe var cnt = 0 // for NoPosition def freshName() = { diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala index a34e97b6cb..bee2ae8e99 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala @@ -34,14 +34,33 @@ trait Implicits { import typingStack.{ printTyping } import typeDebug._ + // standard usage + def inferImplicitFor(pt: Type, tree: Tree, context: Context, reportAmbiguous: Boolean = true): SearchResult = + inferImplicit(tree, pt, reportAmbiguous, isView = false, context, saveAmbiguousDivergent = true, tree.pos) + + // used by typer to find an implicit coercion + def inferImplicitView(from: Type, to: Type, tree: Tree, context: Context, reportAmbiguous: Boolean, saveAmbiguousDivergent: Boolean) = + inferImplicit(tree, Function1(from, to), reportAmbiguous, isView = true, context, saveAmbiguousDivergent, tree.pos) + + // used for manifests, typetags, checking language features, scaladoc + def inferImplicitByType(pt: Type, context: Context, pos: Position = NoPosition): SearchResult = + inferImplicit(EmptyTree, pt, reportAmbiguous = true, isView = false, context, saveAmbiguousDivergent = true, pos) + + def inferImplicitByTypeSilent(pt: Type, context: Context, pos: Position = NoPosition): SearchResult = + inferImplicit(EmptyTree, pt, reportAmbiguous = false, isView = false, context, saveAmbiguousDivergent = false, pos) + + @deprecated("Unused in scalac", "2.12.0-M4") def inferImplicit(tree: Tree, pt: Type, reportAmbiguous: Boolean, isView: Boolean, context: Context): SearchResult = inferImplicit(tree, pt, reportAmbiguous, isView, context, saveAmbiguousDivergent = true, tree.pos) + @deprecated("Unused in scalac", "2.12.0-M4") def inferImplicit(tree: Tree, pt: Type, reportAmbiguous: Boolean, isView: Boolean, context: Context, saveAmbiguousDivergent: Boolean): SearchResult = inferImplicit(tree, pt, reportAmbiguous, isView, context, saveAmbiguousDivergent, tree.pos) - /** Search for an implicit value. See the comment on `result` at the end of class `ImplicitSearch` - * for more info how the search is conducted. + /** Search for an implicit value. Consider using one of the convenience methods above. This one has many boolean levers. + * + * See the comment on `result` at the end of class `ImplicitSearch` for more info how the search is conducted. + * * @param tree The tree for which the implicit needs to be inserted. * (the inference might instantiate some of the undetermined * type parameters of that tree. @@ -92,9 +111,10 @@ trait Implicits { /** A friendly wrapper over inferImplicit to be used in macro contexts and toolboxes. */ def inferImplicit(tree: Tree, pt: Type, isView: Boolean, context: Context, silent: Boolean, withMacrosDisabled: Boolean, pos: Position, onError: (Position, String) => Unit): Tree = { - val wrapper1 = if (!withMacrosDisabled) (context.withMacrosEnabled[SearchResult] _) else (context.withMacrosDisabled[SearchResult] _) - def wrapper(inference: => SearchResult) = wrapper1(inference) - val result = wrapper(inferImplicit(tree, pt, reportAmbiguous = true, isView = isView, context = context, saveAmbiguousDivergent = !silent, pos = pos)) + val result = context.withMacros(enabled = !withMacrosDisabled) { + inferImplicit(tree, pt, reportAmbiguous = true, isView = isView, context, saveAmbiguousDivergent = !silent, pos) + } + if (result.isFailure && !silent) { val err = context.reporter.firstError val errPos = err.map(_.errPos).getOrElse(pos) @@ -304,6 +324,10 @@ trait Implicits { */ object Function1 { val Sym = FunctionClass(1) + val Pre = Sym.typeConstructor.prefix + + def apply(from: Type, to: Type) = TypeRef(Pre, Sym, List(from, to)) + // It is tempting to think that this should be inspecting "tp baseType Sym" // rather than tp. See test case run/t8280 and the commit message which // accompanies it for explanation why that isn't done. @@ -1207,7 +1231,7 @@ trait Implicits { /* Re-wraps a type in a manifest before calling inferImplicit on the result */ def findManifest(tp: Type, manifestClass: Symbol = if (full) FullManifestClass else PartialManifestClass) = - inferImplicit(tree, appliedType(manifestClass, tp), reportAmbiguous = true, isView = false, context).tree + inferImplicitFor(appliedType(manifestClass, tp), tree, context).tree def findSubManifest(tp: Type) = findManifest(tp, if (full) FullManifestClass else OptManifestClass) def mot(tp0: Type, from: List[Symbol], to: List[Type]): SearchResult = { diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala index 684cf788a4..dc91d23011 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala @@ -164,7 +164,9 @@ trait Infer extends Checkable { | was: $restpe | now""")(normalize(restpe)) case mt @ MethodType(_, restpe) if mt.isImplicit => normalize(restpe) - case mt @ MethodType(_, restpe) if !mt.isDependentMethodType => functionType(mt.paramTypes, normalize(restpe)) + case mt @ MethodType(_, restpe) if !mt.isDependentMethodType => + if (phase.erasedTypes) FunctionClass(mt.params.length).tpe + else functionType(mt.paramTypes, normalize(restpe)) case NullaryMethodType(restpe) => normalize(restpe) case ExistentialType(tparams, qtpe) => newExistentialType(tparams, normalize(qtpe)) case _ => tp // @MAT aliases already handled by subtyping @@ -295,7 +297,7 @@ trait Infer extends Checkable { && !isByNameParamType(tp) && isCompatible(tp, dropByName(pt)) ) - def isCompatibleSam(tp: Type, pt: Type): Boolean = { + def isCompatibleSam(tp: Type, pt: Type): Boolean = (definitions.isFunctionType(tp) || tp.isInstanceOf[MethodType] || tp.isInstanceOf[PolyType]) && { val samFun = typer.samToFunctionType(pt) (samFun ne NoType) && isCompatible(tp, samFun) } @@ -1218,7 +1220,7 @@ trait Infer extends Checkable { } def inferModulePattern(pat: Tree, pt: Type) = - if (!(pat.tpe <:< pt)) { + if ((pat.symbol ne null) && pat.symbol.isModule && !(pat.tpe <:< pt)) { val ptparams = freeTypeParamsOfTerms(pt) debuglog("free type params (2) = " + ptparams) val ptvars = ptparams map freshVar diff --git a/src/compiler/scala/tools/nsc/typechecker/Tags.scala b/src/compiler/scala/tools/nsc/typechecker/Tags.scala index 56127f4026..e29451f379 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Tags.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Tags.scala @@ -13,16 +13,7 @@ trait Tags { private val runDefinitions = currentRun.runDefinitions private def resolveTag(pos: Position, taggedTp: Type, allowMaterialization: Boolean) = enteringTyper { - def wrapper (tree: => Tree): Tree = if (allowMaterialization) (context.withMacrosEnabled[Tree](tree)) else (context.withMacrosDisabled[Tree](tree)) - wrapper(inferImplicit( - EmptyTree, - taggedTp, - reportAmbiguous = true, - isView = false, - context, - saveAmbiguousDivergent = true, - pos - ).tree) + context.withMacros(enabled = allowMaterialization) { inferImplicitByType(taggedTp, context, pos).tree } } /** Finds in scope or materializes a ClassTag. diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 9446a45c06..fdf7058ab1 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -105,7 +105,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper // that are turned private by typedBlock private final val SYNTHETIC_PRIVATE = TRANS_FLAG - private final val InterpolatorCodeRegex = """\$\{.*?\}""".r + private final val InterpolatorCodeRegex = """\$\{\s*(.*?)\s*\}""".r private final val InterpolatorIdentRegex = """\$[$\w]+""".r // note that \w doesn't include $ abstract class Typer(context0: Context) extends TyperDiagnostics with Adaptation with Tag with PatternTyper with TyperContextErrors { @@ -158,7 +158,9 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper for(ar <- argResultsBuff) paramTp = paramTp.subst(ar.subst.from, ar.subst.to) - val res = if (paramFailed || (paramTp.isErroneous && {paramFailed = true; true})) SearchFailure else inferImplicit(fun, paramTp, context.reportErrors, isView = false, context) + val res = + if (paramFailed || (paramTp.isErroneous && {paramFailed = true; true})) SearchFailure + else inferImplicitFor(paramTp, fun, context, reportAmbiguous = context.reportErrors) argResultsBuff += res if (res.isSuccess) { @@ -194,14 +196,12 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper !from.isError && !to.isError && context.implicitsEnabled - && (inferView(context.tree, from, to, reportAmbiguous = false, saveErrors = true) != EmptyTree) + && (inferView(context.tree, from, to, reportAmbiguous = false) != EmptyTree) // SI-8230 / SI-8463 We'd like to change this to `saveErrors = false`, but can't. // For now, we can at least pass in `context.tree` rather then `EmptyTree` so as // to avoid unpositioned type errors. ) - def inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean): Tree = - inferView(tree, from, to, reportAmbiguous, saveErrors = true) /** Infer an implicit conversion (`view`) between two types. * @param tree The tree which needs to be converted. @@ -214,25 +214,23 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * during the inference of a view be put into the original buffer. * False iff we don't care about them. */ - def inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = { - debuglog("infer view from "+from+" to "+to)//debug - if (isPastTyper) EmptyTree - else from match { - case MethodType(_, _) => EmptyTree - case OverloadedType(_, _) => EmptyTree - case PolyType(_, _) => EmptyTree - case _ => - def wrapImplicit(from: Type): Tree = { - val result = inferImplicit(tree, functionType(from.withoutAnnotations :: Nil, to), reportAmbiguous, isView = true, context, saveAmbiguousDivergent = saveErrors) - if (result.subst != EmptyTreeTypeSubstituter) { - result.subst traverse tree - notifyUndetparamsInferred(result.subst.from, result.subst.to) - } - result.tree - } - wrapImplicit(from) orElse wrapImplicit(byNameType(from)) + def inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean = true, saveErrors: Boolean = true): Tree = + if (isPastTyper || from.isInstanceOf[MethodType] || from.isInstanceOf[OverloadedType] || from.isInstanceOf[PolyType]) EmptyTree + else { + debuglog(s"Inferring view from $from to $to for $tree (reportAmbiguous= $reportAmbiguous, saveErrors=$saveErrors)") + + val fromNoAnnot = from.withoutAnnotations + val result = inferImplicitView(fromNoAnnot, to, tree, context, reportAmbiguous, saveErrors) match { + case fail if fail.isFailure => inferImplicitView(byNameType(fromNoAnnot), to, tree, context, reportAmbiguous, saveErrors) + case ok => ok + } + + if (result.subst != EmptyTreeTypeSubstituter) { + result.subst traverse tree + notifyUndetparamsInferred(result.subst.from, result.subst.to) + } + result.tree } - } import infer._ @@ -246,6 +244,10 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper var context = context0 def context1 = context + // for use with silent type checking to when we can't have results with undetermined type params + // note that this captures the context var + val isMonoContext = (_: Any) => context.undetparams.isEmpty + def dropExistential(tp: Type): Type = tp match { case ExistentialType(tparams, tpe) => new SubstWildcardMap(tparams).apply(tp) @@ -732,7 +734,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper featureTrait.owner.ownerChain.takeWhile(_ != languageFeatureModule.moduleClass).reverse val featureName = (nestedOwners map (_.name + ".")).mkString + featureTrait.name def action(): Boolean = { - def hasImport = inferImplicit(EmptyTree: Tree, featureTrait.tpe, reportAmbiguous = true, isView = false, context).isSuccess + def hasImport = inferImplicitByType(featureTrait.tpe, context).isSuccess def hasOption = settings.language contains featureName val OK = hasImport || hasOption if (!OK) { @@ -809,7 +811,8 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * (11) Widen numeric literals to their expected type, if necessary * (12) When in mode EXPRmode, convert E to { E; () } if expected type is scala.Unit. * (13) When in mode EXPRmode, apply AnnotationChecker conversion if expected type is annotated. - * (14) When in mode EXPRmode, apply a view + * (14) When in mode EXPRmode, do SAM conversion + * (15) When in mode EXPRmode, apply a view * If all this fails, error */ protected def adapt(tree: Tree, mode: Mode, pt: Type, original: Tree = EmptyTree): Tree = { @@ -1021,72 +1024,70 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper } } - def fallbackAfterVanillaAdapt(): Tree = { - def isPopulatedPattern = { - if ((tree.symbol ne null) && tree.symbol.isModule) - inferModulePattern(tree, pt) - - isPopulated(tree.tpe, approximateAbstracts(pt)) + def adaptExprNotFunMode(): Tree = { + def lastTry(err: AbsTypeError = null): Tree = { + debuglog("error tree = " + tree) + if (settings.debug && settings.explaintypes) explainTypes(tree.tpe, pt) + if (err ne null) context.issue(err) + if (tree.tpe.isErroneous || pt.isErroneous) setError(tree) + else adaptMismatchedSkolems() } - if (mode.inPatternMode && isPopulatedPattern) - return tree - val tree1 = constfold(tree, pt) // (10) (11) - if (tree1.tpe <:< pt) - return adapt(tree1, mode, pt, original) + // TODO: should we even get to fallbackAfterVanillaAdapt for an ill-typed tree? + if (mode.typingExprNotFun && !tree.tpe.isErroneous) { + @inline def tpdPos(transformed: Tree) = typedPos(tree.pos, mode, pt)(transformed) + @inline def tpd(transformed: Tree) = typed(transformed, mode, pt) - if (mode.typingExprNotFun) { - // The <: Any requirement inhibits attempts to adapt continuation types - // to non-continuation types. - if (tree.tpe <:< AnyTpe) pt.dealias match { - case TypeRef(_, UnitClass, _) => // (12) - if (!isPastTyper && settings.warnValueDiscard) - context.warning(tree.pos, "discarded non-Unit value") - return typedPos(tree.pos, mode, pt)(Block(List(tree), Literal(Constant(())))) - case TypeRef(_, sym, _) if isNumericValueClass(sym) && isNumericSubType(tree.tpe, pt) => - if (!isPastTyper && settings.warnNumericWiden) - context.warning(tree.pos, "implicit numeric widening") - return typedPos(tree.pos, mode, pt)(Select(tree, "to" + sym.name)) - case _ => - } - if (pt.dealias.annotations.nonEmpty && canAdaptAnnotations(tree, this, mode, pt)) // (13) - return typed(adaptAnnotations(tree, this, mode, pt), mode, pt) + @inline def warnValueDiscard(): Unit = + if (!isPastTyper && settings.warnValueDiscard) context.warning(tree.pos, "discarded non-Unit value") + @inline def warnNumericWiden(): Unit = + if (!isPastTyper && settings.warnNumericWiden) context.warning(tree.pos, "implicit numeric widening") - if (hasUndets) - return instantiate(tree, mode, pt) - - if (context.implicitsEnabled && !pt.isError && !tree.isErrorTyped) { - // (14); the condition prevents chains of views - debuglog("inferring view from " + tree.tpe + " to " + pt) - inferView(tree, tree.tpe, pt, reportAmbiguous = true) match { - case EmptyTree => - case coercion => - def msg = "inferred view from " + tree.tpe + " to " + pt + " = " + coercion + ":" + coercion.tpe - if (settings.logImplicitConv) - context.echo(tree.pos, msg) - - debuglog(msg) - val silentContext = context.makeImplicit(context.ambiguousErrors) - val res = newTyper(silentContext).typed( - new ApplyImplicitView(coercion, List(tree)) setPos tree.pos, mode, pt) - silentContext.reporter.firstError match { - case Some(err) => context.issue(err) - case None => return res + // The <: Any requirement inhibits attempts to adapt continuation types to non-continuation types. + val anyTyped = tree.tpe <:< AnyTpe + + pt.dealias match { + case TypeRef(_, UnitClass, _) if anyTyped => // (12) + warnValueDiscard() ; tpdPos(gen.mkUnitBlock(tree)) + case TypeRef(_, numValueCls, _) if anyTyped && isNumericValueClass(numValueCls) && isNumericSubType(tree.tpe, pt) => // (10) (11) + warnNumericWiden() ; tpdPos(Select(tree, s"to${numValueCls.name}")) + case dealiased if dealiased.annotations.nonEmpty && canAdaptAnnotations(tree, this, mode, pt) => // (13) + tpd(adaptAnnotations(tree, this, mode, pt)) + case _ => + if (hasUndets) instantiate(tree, mode, pt) + else { + // (14) sam conversion + // TODO: figure out how to avoid partially duplicating typedFunction (samMatchingFunction) + // Could we infer the SAM type, assign it to the tree and add the attachment, + // all in one fell swoop at the end of typedFunction? + val samAttach = inferSamType(tree, pt, mode) + + if (samAttach.samTp ne NoType) tree.setType(samAttach.samTp).updateAttachment(samAttach) + else { // (15) implicit view application + val coercion = + if (context.implicitsEnabled) inferView(tree, tree.tpe, pt) + else EmptyTree + if (coercion ne EmptyTree) { + def msg = s"inferred view from ${tree.tpe} to $pt via $coercion: ${coercion.tpe}" + if (settings.logImplicitConv) context.echo(tree.pos, msg) + else debuglog(msg) + + val viewApplied = new ApplyImplicitView(coercion, List(tree)) setPos tree.pos + val silentContext = context.makeImplicit(context.ambiguousErrors) + val typedView = newTyper(silentContext).typed(viewApplied, mode, pt) + + silentContext.reporter.firstError match { + case None => typedView + case Some(err) => lastTry(err) + } + } else lastTry() } - } + } } - } - - debuglog("error tree = " + tree) - if (settings.debug && settings.explaintypes) - explainTypes(tree.tpe, pt) - - if (tree.tpe.isErroneous || pt.isErroneous) - setError(tree) - else - adaptMismatchedSkolems() + } else lastTry() } + def vanillaAdapt(tree: Tree) = { def applyPossible = { def applyMeth = member(adaptToName(tree, nme.apply), nme.apply) @@ -1120,8 +1121,13 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper } else if (tree.tpe <:< pt) tree - else - fallbackAfterVanillaAdapt() + else if (mode.inPatternMode && { inferModulePattern(tree, pt); isPopulated(tree.tpe, approximateAbstracts(pt)) }) + tree + else { + val constFolded = constfold(tree, pt) + if (constFolded.tpe <:< pt) adapt(constFolded, mode, pt, original) // set stage for (0) + else adaptExprNotFunMode() // (10) -- (15) + } } // begin adapt @@ -1186,7 +1192,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper val savedUndetparams = context.undetparams silent(_.instantiate(tree, mode, UnitTpe)) orElse { _ => context.undetparams = savedUndetparams - val valueDiscard = atPos(tree.pos)(Block(List(instantiate(tree, mode, WildcardType)), Literal(Constant(())))) + val valueDiscard = atPos(tree.pos)(gen.mkUnitBlock(instantiate(tree, mode, WildcardType))) typed(valueDiscard, mode, UnitTpe) } } @@ -1247,7 +1253,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * If no conversion is found, return `qual` unchanged. * */ - def adaptToArguments(qual: Tree, name: Name, args: List[Tree], pt: Type, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = { + def adaptToArguments(qual: Tree, name: Name, args: List[Tree], pt: Type, reportAmbiguous: Boolean = true, saveErrors: Boolean = true): Tree = { def doAdapt(restpe: Type) = //util.trace("adaptToArgs "+qual+", name = "+name+", argtpes = "+(args map (_.tpe))+", pt = "+pt+" = ") adaptToMember(qual, HasMethodMatching(name, args map (_.tpe), restpe), reportAmbiguous, saveErrors) @@ -1263,7 +1269,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * a method `name`. If that's ambiguous try taking arguments into * account using `adaptToArguments`. */ - def adaptToMemberWithArgs(tree: Tree, qual: Tree, name: Name, mode: Mode, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = { + def adaptToMemberWithArgs(tree: Tree, qual: Tree, name: Name, mode: Mode, reportAmbiguous: Boolean = true, saveErrors: Boolean = true): Tree = { def onError(reportError: => Tree): Tree = context.tree match { case Apply(tree1, args) if (tree1 eq tree) && args.nonEmpty => ( silent (_.typedArgs(args.map(_.duplicate), mode)) @@ -1745,17 +1751,21 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper classinfo.parents map (_.instantiateTypeParams(List(tparam), List(AnyRefTpe))), classinfo.decls, clazz) - clazz.setInfo { - clazz.info match { - case PolyType(tparams, _) => PolyType(tparams, newinfo) - case _ => newinfo - } - } + updatePolyClassInfo(clazz, newinfo) FinitaryError(tparam) } } } + private def updatePolyClassInfo(clazz: Symbol, newinfo: ClassInfoType): clazz.type = { + clazz.setInfo { + clazz.info match { + case PolyType(tparams, _) => PolyType(tparams, newinfo) + case _ => newinfo + } + } + } + def typedClassDef(cdef: ClassDef): Tree = { val clazz = cdef.symbol val typedMods = typedModifiers(cdef.mods) @@ -1864,6 +1874,26 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper // please FIXME: uncommenting this line breaks everything // val templ = treeCopy.Template(templ0, templ0.body, templ0.self, templ0.parents) val clazz = context.owner + + val parentTypes = parents1.map(_.tpe) + + // The parents may have been normalized by typedParentTypes. + // We must update the info as well, or we won't find the super constructor for our now-first parent class + // Consider `class C ; trait T extends C ; trait U extends T` + // `U`'s info will start with parent `T`, but `typedParentTypes` will return `List(C, T)` (`== parents1`) + // now, the super call in the primary ctor will fail to find `C`'s ctor, since it bases its search on + // `U`'s info, not the trees. + // + // For correctness and performance, we restrict this rewrite to anonymous classes, + // as others have their parents in order already (it seems!), and we certainly + // don't want to accidentally rewire superclasses for e.g. the primitive value classes. + // + // TODO: Find an example of a named class needing this rewrite, I tried but couldn't find one. + if (clazz.isAnonymousClass && clazz.info.parents != parentTypes) { +// println(s"updating parents of $clazz from ${clazz.info.parents} to $parentTypes") + updatePolyClassInfo(clazz, ClassInfoType(parentTypes, clazz.info.decls, clazz)) + } + clazz.annotations.map(_.completeInfo()) if (templ.symbol == NoSymbol) templ setSymbol clazz.newLocalDummy(templ.pos) @@ -2713,187 +2743,99 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper } } - /** Synthesize and type check the implementation of a type with a Single Abstract Method - * - * `{ (p1: T1, ..., pN: TN) => body } : S` - * - * expands to (where `S` is the expected type that defines a single abstract method named `apply`) - * - * `{ - * def apply$body(p1: T1, ..., pN: TN): T = body - * new S { - * def apply(p1: T1', ..., pN: TN'): T' = apply$body(p1,..., pN) - * } - * }` - * - * If 'T' is not fully defined, it is inferred by type checking - * `apply$body` without a result type before type checking the block. - * The method's inferred result type is used instead of `T`. [See test/files/pos/sammy_poly.scala] - * - * The `apply` method is identified by the argument `sam`; `S` corresponds to the argument `samClassTp`, - * and `resPt` is derived from `samClassTp` -- it may be fully defined, or not... - * If it is not fully defined, we derive `samClassTpFullyDefined` by inferring any unknown type parameters. - * - * The types T1' ... TN' and T' are derived from the method signature of the sam method, - * as seen from the fully defined `samClassTpFullyDefined`. - * - * The function's body is put in a method outside of the class definition to enforce scoping. - * S's members should not be in scope in `body`. - * - * The restriction on implicit arguments (neither S's constructor, nor sam may take an implicit argument list), - * is largely to keep the implementation of type inference (the computation of `samClassTpFullyDefined`) simple. - * - * NOTE: it would be nicer to not have to type check `apply$body` separately when `T` is not fully defined. - * However T must be fully defined before we type the instantiation, as it'll end up as a parent type, - * which must be fully defined. Would be nice to have some kind of mechanism to insert type vars in a block of code, - * and have the instantiation of the first occurrence propagate to the rest of the block. - * - * TODO: by-name params - * scala> trait LazySink { def accept(a: => Any): Unit } - * defined trait LazySink - * - * scala> val f: LazySink = (a) => (a, a) - * f: LazySink = $anonfun$1@1fb26910 - * - * scala> f(println("!")) - * <console>:10: error: LazySink does not take parameters - * f(println("!")) - * ^ - * - * scala> f.accept(println("!")) - * ! - * ! - */ - def synthesizeSAMFunction(sam: Symbol, fun: Function, resPt: Type, samClassTp: Type, mode: Mode): Tree = { - // assert(fun.vparams forall (vp => isFullyDefined(vp.tpt.tpe))) -- by construction, as we take them from sam's info - val sampos = fun.pos - - // if the expected sam type is fully defined, use it for the method's result type - // otherwise, NoType, so that type inference will determine the method's result type - // resPt is syntactically contained in samClassTp, so if the latter is fully defined, so is the former - // ultimately, we want to fully define samClassTp as it is used as the superclass of our anonymous class - val samDefTp = if (isFullyDefined(resPt)) resPt else NoType - val bodyName = newTermName(sam.name + "$body") - - // `def '${sam.name}\$body'($p1: $T1, ..., $pN: $TN): $resPt = $body` - val samBodyDef = - DefDef(NoMods, - bodyName, - Nil, - List(fun.vparams.map(_.duplicate)), // must duplicate as we're also using them for `samDef` - TypeTree(samDefTp) setPos sampos.focus, - fun.body) - - // If we need to enter the sym for the body def before type checking the block, - // we'll create a nested context, as explained below. - var nestedTyper = this - - // Type check body def before classdef to fully determine samClassTp (if necessary). - // As `samClassTp` determines a parent type for the class, - // we can't type check `block` in one go unless `samClassTp` is fully defined. - val samClassTpFullyDefined = - if (isFullyDefined(samClassTp)) samClassTp + /** Synthesize and type check the implementation of a type with a Single Abstract Method. + * + * Based on a type checked Function node `{ (p1: T1, ..., pN: TN) => body } : S` + * where `S` is the expected type that defines a single abstract method (call it `apply` for the example), + * that has signature `(p1: T1', ..., pN: TN'): T'`, synthesize the instantiation of the following anonymous class + * + * ``` + * new S { + * def apply$body(p1: T1, ..., pN: TN): T = body + * def apply(p1: T1', ..., pN: TN'): T' = apply$body(p1,..., pN) + * } + * ``` + * + * The `apply` method is identified by the argument `sam`; `S` corresponds to the argument `pt`, + * If `pt` is not fully defined, we derive `samClassTpFullyDefined` by inferring any unknown type parameters. + * + * The types T1' ... TN' and T' are derived from the method signature of the sam method, + * as seen from the fully defined `samClassTpFullyDefined`. + * + * The function's body is put in a (static) method in the class definition to enforce scoping. + * S's members should not be in scope in `body`. (Putting it in the block outside the class runs into implementation problems described below) + * + * The restriction on implicit arguments (neither S's constructor, nor sam may take an implicit argument list), + * is to keep the implementation of type inference (the computation of `samClassTpFullyDefined`) simple. + * + * Impl notes: + * - `fun` has a FunctionType, but the expected type `pt` is some SAM type -- let's remedy that + * - `fun` is fully attributed, so we'll have to wrangle some symbols into shape (owner change, vparam syms) + * - after experimentation, it works best to type check function literals fully first and then adapt to a sam type, + * as opposed to a sam-specific code paths earlier on in type checking (in typedFunction). + * For one, we want to emit the same bytecode regardless of whether the expected + * function type is a built-in FunctionN or some SAM type + * + */ + def inferSamType(fun: Tree, pt: Type, mode: Mode): SAMFunction = { + val sam = + if (fun.isInstanceOf[Function] && !isFunctionType(pt)) { + // TODO: can we ensure there's always a SAMFunction attachment, instead of looking up the sam again??? + // seems like overloading complicates things? + val sam = samOf(pt) + if (samMatchesFunctionBasedOnArity(sam, fun.asInstanceOf[Function].vparams)) sam + else NoSymbol + } else NoSymbol + + def fullyDefinedMeetsExpectedFunTp(pt: Type): Boolean = isFullyDefined(pt) && { + val samMethType = pt memberInfo sam + fun.tpe <:< functionType(samMethType.paramTypes, samMethType.resultType) + } + + SAMFunction( + if (!sam.exists) NoType + else if (fullyDefinedMeetsExpectedFunTp(pt)) pt else try { - // This creates a symbol for samBodyDef with a type completer that'll be triggered immediately below. - // The symbol is entered in the same scope used for the block below, and won't thus be reentered later. - // It has to be a new scope, though, or we'll "get ambiguous reference to overloaded definition" [pos/sammy_twice.scala] - // makeSilent: [pos/nonlocal-unchecked.scala -- when translation all functions to sams] - val nestedCtx = enterSym(context.makeNewScope(context.tree, context.owner).makeSilent(), samBodyDef) - nestedTyper = newTyper(nestedCtx) - - // NOTE: this `samBodyDef.symbol.info` runs the type completer set up by the enterSym above - val actualSamType = samBodyDef.symbol.info + val samClassSym = pt.typeSymbol // we're trying to fully define the type arguments for this type constructor - val samTyCon = samClassTp.typeSymbol.typeConstructor + val samTyCon = samClassSym.typeConstructor // the unknowns - val tparams = samClassTp.typeSymbol.typeParams + val tparams = samClassSym.typeParams // ... as typevars - val tvars = tparams map freshVar - - // 1. Recover partial information: - // - derive a type from samClassTp that has the corresponding tparams for type arguments that aren't fully defined - // - constrain typevars to be equal to type args that are fully defined - val samClassTpMoreDefined = appliedType(samTyCon, - (samClassTp.typeArgs, tparams, tvars).zipped map { - case (a, _, tv) if isFullyDefined(a) => tv =:= a; a - case (_, p, _) => p.typeConstructor - }) + val tvars = tparams map freshVar - // the method type we're expecting the synthesized sam to have, based on the expected sam type, - // where fully defined type args to samClassTp have been preserved, - // with the unknown args replaced by their corresponding type param - val expectedSamType = samClassTpMoreDefined.memberInfo(sam) + val ptVars = appliedType(samTyCon, tvars) - // 2. make sure the body def's actual type (formals and result) conforms to - // sam's expected type (in terms of the typevars that represent the sam's class's type params) - actualSamType <:< expectedSamType.substituteTypes(tparams, tvars) + // carry over info from pt + ptVars <:< pt - // solve constraints tracked by tvars - val targs = solvedTypes(tvars, tparams, tparams map varianceInType(sam.info), upper = false, lubDepth(sam.info :: Nil)) - - debuglog(s"sam infer: $samClassTp --> ${appliedType(samTyCon, targs)} by $actualSamType <:< $expectedSamType --> $targs for $tparams") + val samInfoWithTVars = ptVars.memberInfo(sam) - // a fully defined samClassTp - appliedType(samTyCon, targs) - } catch { - case _: NoInstance | _: TypeError => - devWarning(sampos, s"Could not define type $samClassTp using ${samBodyDef.symbol.rawInfo} <:< ${samClassTp memberInfo sam} (for $sam)") - samClassTp - } - - // what's the signature of the method that we should actually be overriding? - val samMethTp = samClassTpFullyDefined memberInfo sam - // Before the mutation, `tp <:< vpar.tpt.tpe` should hold. - // TODO: error message when this is not the case, as the expansion won't type check - // - Ti' <:< Ti and T <: T' must hold for the samDef body to type check - val funArgTps = foreach2(samMethTp.paramTypes, fun.vparams)((tp, vpar) => vpar.tpt setType tp) - - // `final override def ${sam.name}($p1: $T1', ..., $pN: $TN'): ${samMethTp.finalResultType} = ${sam.name}\$body'($p1, ..., $pN)` - val samDef = - DefDef(Modifiers(FINAL | OVERRIDE | SYNTHETIC), - sam.name.toTermName, - Nil, - List(fun.vparams), - TypeTree(samMethTp.finalResultType) setPos sampos.focus, - Apply(Ident(bodyName), fun.vparams map gen.paramToArg) - ) + // use function type subtyping, not method type subtyping (the latter is invariant in argument types) + fun.tpe <:< functionType(samInfoWithTVars.paramTypes, samInfoWithTVars.finalResultType) - val serializableParentAddendum = - if (typeIsSubTypeOfSerializable(samClassTp)) Nil - else List(TypeTree(SerializableTpe)) - - val classDef = - ClassDef(Modifiers(FINAL), tpnme.ANON_FUN_NAME, tparams = Nil, - gen.mkTemplate( - parents = TypeTree(samClassTpFullyDefined) :: serializableParentAddendum, - self = noSelfType, - constrMods = NoMods, - vparamss = ListOfNil, - body = List(samDef), - superPos = sampos.focus - ) - ) + val variances = tparams map varianceInType(sam.info) - // type checking the whole block, so that everything is packaged together nicely - // and we don't have to create any symbols by hand - val block = - nestedTyper.typedPos(sampos, mode, samClassTpFullyDefined) { - Block( - samBodyDef, - classDef, - Apply(Select(New(Ident(tpnme.ANON_FUN_NAME)), nme.CONSTRUCTOR), Nil) - ) - } + // solve constraints tracked by tvars + val targs = solvedTypes(tvars, tparams, variances, upper = false, lubDepth(sam.info :: Nil)) - // TODO: improve error reporting -- when we're in silent mode (from `silent(_.doTypedApply(tree, fun, args, mode, pt)) orElse onError`) - // the errors in the function don't get out... - if (block exists (_.isErroneous)) - context.error(fun.pos, s"Could not derive subclass of $samClassTp\n (with SAM `def $sam$samMethTp`)\n based on: $fun.") + debuglog(s"sam infer: $pt --> ${appliedType(samTyCon, targs)} by ${fun.tpe} <:< $samInfoWithTVars --> $targs for $tparams") - classDef.symbol addAnnotation SerialVersionUIDAnnotation - block + val ptFullyDefined = appliedType(samTyCon, targs) + if (ptFullyDefined <:< pt && fullyDefinedMeetsExpectedFunTp(ptFullyDefined)) { + debuglog(s"sam fully defined expected type: $ptFullyDefined from $pt for ${fun.tpe}") + ptFullyDefined + } else { + debuglog(s"Could not define type $pt using ${fun.tpe} <:< ${pt memberInfo sam} (for $sam)") + NoType + } + } catch { + case e@(_: NoInstance | _: TypeError) => + debuglog(s"Error during SAM synthesis: could not define type $pt using ${fun.tpe} <:< ${pt memberInfo sam} (for $sam)\n$e") + NoType + }, sam) } /** Type check a function literal. @@ -2903,16 +2845,19 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * - a type with a Single Abstract Method (under -Xexperimental for now). */ private def typedFunction(fun: Function, mode: Mode, pt: Type): Tree = { - val numVparams = fun.vparams.length + val vparams = fun.vparams + val numVparams = vparams.length val FunctionSymbol = if (numVparams > definitions.MaxFunctionArity) NoSymbol else FunctionClass(numVparams) + val ptSym = pt.typeSymbol + /* The Single Abstract Member of pt, unless pt is the built-in function type of the expected arity, * as `(a => a): Int => Int` should not (yet) get the sam treatment. */ val sam = - if (pt.typeSymbol == FunctionSymbol) NoSymbol + if (ptSym == NoSymbol || ptSym == FunctionSymbol || ptSym == PartialFunctionClass) NoSymbol else samOf(pt) /* The SAM case comes first so that this works: @@ -2920,79 +2865,101 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper * (a => a): MyFun * * Note that the arity of the sam must correspond to the arity of the function. + * TODO: handle vararg sams? */ - val samViable = sam.exists && sameLength(sam.info.params, fun.vparams) - val ptNorm = if (samViable) samToFunctionType(pt, sam) else pt + val ptNorm = + if (samMatchesFunctionBasedOnArity(sam, vparams)) samToFunctionType(pt, sam) + else pt val (argpts, respt) = ptNorm baseType FunctionSymbol match { case TypeRef(_, FunctionSymbol, args :+ res) => (args, res) - case _ => (fun.vparams map (_ => if (pt == ErrorType) ErrorType else NoType), WildcardType) + case _ => (vparams map (if (pt == ErrorType) (_ => ErrorType) else (_ => NoType)), WildcardType) } - if (!FunctionSymbol.exists) - MaxFunctionArityError(fun) - else if (argpts.lengthCompare(numVparams) != 0) - WrongNumberOfParametersError(fun, argpts) + if (!FunctionSymbol.exists) MaxFunctionArityError(fun) + else if (argpts.lengthCompare(numVparams) != 0) WrongNumberOfParametersError(fun, argpts) else { - var issuedMissingParameterTypeError = false - foreach2(fun.vparams, argpts) { (vparam, argpt) => - if (vparam.tpt.isEmpty) { - val vparamType = - if (isFullyDefined(argpt)) argpt - else { - fun match { - case etaExpansion(vparams, fn, args) => - silent(_.typed(fn, mode.forFunMode, pt)) filter (_ => context.undetparams.isEmpty) map { fn1 => - // if context.undetparams is not empty, the function was polymorphic, - // so we need the missing arguments to infer its type. See #871 - //println("typing eta "+fun+":"+fn1.tpe+"/"+context.undetparams) - val ftpe = normalize(fn1.tpe) baseType FunctionClass(numVparams) - if (isFunctionType(ftpe) && isFullyDefined(ftpe)) - return typedFunction(fun, mode, ftpe) - } - case _ => - } - MissingParameterTypeError(fun, vparam, pt, withTupleAddendum = !issuedMissingParameterTypeError) - issuedMissingParameterTypeError = true - ErrorType - } - vparam.tpt.setType(vparamType) + val paramsMissingType = mutable.ArrayBuffer.empty[ValDef] //.sizeHint(numVparams) probably useless, since initial size is 16 and max fun arity is 22 + // first, try to define param types from expected function's arg types if needed + foreach2(vparams, argpts) { (vparam, argpt) => + if (vparam.tpt isEmpty) { + if (isFullyDefined(argpt)) vparam.tpt setType argpt + else paramsMissingType += vparam + if (!vparam.tpt.pos.isDefined) vparam.tpt setPos vparam.pos.focus } } - fun.body match { - // translate `x => x match { <cases> }` : PartialFunction to - // `new PartialFunction { def applyOrElse(x, default) = x match { <cases> } def isDefinedAt(x) = ... }` - case Match(sel, cases) if (sel ne EmptyTree) && (pt.typeSymbol == PartialFunctionClass) => - // go to outer context -- must discard the context that was created for the Function since we're discarding the function - // thus, its symbol, which serves as the current context.owner, is not the right owner - // you won't know you're using the wrong owner until lambda lift crashes (unless you know better than to use the wrong owner) - val outerTyper = newTyper(context.outer) - val p = fun.vparams.head - if (p.tpt.tpe == null) p.tpt setType outerTyper.typedType(p.tpt).tpe + // If we're typing `(a1: T1, ..., aN: TN) => m(a1,..., aN)`, where some Ti are not fully defined, + // type `m` directly (undoing eta-expansion of method m) to determine the argument types. + // This tree is the result from one of: + // - manual eta-expansion with named arguments (x => f(x)); + // - wildcard-style eta expansion (`m(_, _,)`); + // - instantiateToMethodType adapting a tree of method type to a function type using etaExpand. + // + // Note that method values are a separate thing (`m _`): they have the idiosyncratic shape + // of `Typed(expr, Function(Nil, EmptyTree))` + val ptUnrollingEtaExpansion = + if (paramsMissingType.nonEmpty && pt != ErrorType) fun.body match { + // we can compare arguments and parameters by name because there cannot be a binder between + // the function's valdefs and the Apply's arguments + case Apply(meth, args) if (vparams corresponds args) { case (p, Ident(name)) => p.name == name case _ => false } => + // We're looking for a method (as indicated by FUNmode in the silent typed below), + // so let's make sure our expected type is a MethodType + val methArgs = NoSymbol.newSyntheticValueParams(argpts map { case NoType => WildcardType case tp => tp }) + silent(_.typed(meth, mode.forFunMode, MethodType(methArgs, respt))) filter (isMonoContext) map { methTyped => + // if context.undetparams is not empty, the method was polymorphic, + // so we need the missing arguments to infer its type. See #871 + val funPt = normalize(methTyped.tpe) baseType FunctionClass(numVparams) + // println(s"typeUnEtaExpanded $meth : ${methTyped.tpe} --> normalized: $funPt") + + // If we are sure this function type provides all the necesarry info, so that we won't have + // any undetermined argument types, go ahead an recurse below (`typedFunction(fun, mode, ptUnrollingEtaExpansion)`) + // and rest assured we won't end up right back here (and keep recursing) + if (isFunctionType(funPt) && funPt.typeArgs.iterator.take(numVparams).forall(isFullyDefined)) funPt + else null + } orElse { _ => null } + case _ => null + } else null + + + if (ptUnrollingEtaExpansion ne null) typedFunction(fun, mode, ptUnrollingEtaExpansion) + else { + // we ran out of things to try, missing parameter types are an irrevocable error + var issuedMissingParameterTypeError = false + paramsMissingType.foreach { vparam => + vparam.tpt setType ErrorType + MissingParameterTypeError(fun, vparam, pt, withTupleAddendum = !issuedMissingParameterTypeError) + issuedMissingParameterTypeError = true + } - outerTyper.synthesizePartialFunction(p.name, p.pos, paramSynthetic = false, fun.body, mode, pt) + fun.body match { + // translate `x => x match { <cases> }` : PartialFunction to + // `new PartialFunction { def applyOrElse(x, default) = x match { <cases> } def isDefinedAt(x) = ... }` + case Match(sel, cases) if (sel ne EmptyTree) && (pt.typeSymbol == PartialFunctionClass) => + // go to outer context -- must discard the context that was created for the Function since we're discarding the function + // thus, its symbol, which serves as the current context.owner, is not the right owner + // you won't know you're using the wrong owner until lambda lift crashes (unless you know better than to use the wrong owner) + val outerTyper = newTyper(context.outer) + val p = vparams.head + if (p.tpt.tpe == null) p.tpt setType outerTyper.typedType(p.tpt).tpe - // Use synthesizeSAMFunction to expand `(p1: T1, ..., pN: TN) => body` - // to an instance of the corresponding anonymous subclass of `pt`. - case _ if samViable => - newTyper(context.outer).synthesizeSAMFunction(sam, fun, respt, pt, mode) + outerTyper.synthesizePartialFunction(p.name, p.pos, paramSynthetic = false, fun.body, mode, pt) - // regular Function - case _ => - val vparamSyms = fun.vparams map { vparam => - enterSym(context, vparam) - if (context.retyping) context.scope enter vparam.symbol - vparam.symbol - } - val vparams = fun.vparams mapConserve typedValDef - val formals = vparamSyms map (_.tpe) - val body1 = typed(fun.body, respt) - val restpe = packedType(body1, fun.symbol).deconst.resultType - val funtpe = phasedAppliedType(FunctionSymbol, formals :+ restpe) + case _ => + val vparamSyms = vparams map { vparam => + enterSym(context, vparam) + if (context.retyping) context.scope enter vparam.symbol + vparam.symbol + } + val vparamsTyped = vparams mapConserve typedValDef + val formals = vparamSyms map (_.tpe) + val body1 = typed(fun.body, respt) + val restpe = packedType(body1, fun.symbol).deconst.resultType + val funtpe = phasedAppliedType(FunctionSymbol, formals :+ restpe) - treeCopy.Function(fun, vparams, body1) setType funtpe + treeCopy.Function(fun, vparamsTyped, body1) setType funtpe + } } } } @@ -3222,7 +3189,10 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper // less expensive than including them in inferMethodAlternative (see below). def shapeType(arg: Tree): Type = arg match { case Function(vparams, body) => - functionType(vparams map (_ => AnyTpe), shapeType(body)) // TODO: should this be erased when retyping during erasure? + // No need for phasedAppliedType, as we don't get here during erasure -- + // overloading resolution happens during type checking. + // During erasure, the condition above (fun.symbol.isOverloaded) is false. + functionType(vparams map (_ => AnyTpe), shapeType(body)) case AssignOrNamedArg(Ident(name), rhs) => NamedType(name, shapeType(rhs)) case _ => @@ -4303,7 +4273,8 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper if (pt.typeSymbol == PartialFunctionClass) synthesizePartialFunction(newTermName(context.unit.fresh.newName("x")), tree.pos, paramSynthetic = true, tree, mode, pt) else { - val arity = if (isFunctionType(pt)) pt.dealiasWiden.typeArgs.length - 1 else 1 + val arity = functionArityFromType(pt) match { case -1 => 1 case arity => arity } // SI-8429: consider sam and function type equally in determining function arity + val params = for (i <- List.range(0, arity)) yield atPos(tree.pos.focusStart) { ValDef(Modifiers(PARAM | SYNTHETIC), @@ -4403,31 +4374,43 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper treeCopy.New(tree, tpt1).setType(tp) } - def functionTypeWildcard(tree: Tree, arity: Int): Type = { - val tp = functionType(List.fill(arity)(WildcardType), WildcardType) - if (tp == NoType) MaxFunctionArityError(tree) - tp - } - - def typedEta(expr1: Tree): Tree = expr1.tpe match { - case TypeRef(_, ByNameParamClass, _) => - val expr2 = Function(List(), expr1) setPos expr1.pos - new ChangeOwnerTraverser(context.owner, expr2.symbol).traverse(expr2) - typed1(expr2, mode, pt) - case NullaryMethodType(restpe) => - val expr2 = Function(List(), expr1) setPos expr1.pos - new ChangeOwnerTraverser(context.owner, expr2.symbol).traverse(expr2) - typed1(expr2, mode, pt) - case PolyType(_, MethodType(formals, _)) => - if (isFunctionType(pt)) expr1 - else adapt(expr1, mode, functionTypeWildcard(expr1, formals.length)) - case MethodType(formals, _) => - if (isFunctionType(pt)) expr1 - else adapt(expr1, mode, functionTypeWildcard(expr1, formals.length)) + def functionTypeWildcard(arity: Int): Type = + functionType(List.fill(arity)(WildcardType), WildcardType) + + def checkArity(tree: Tree)(tp: Type): tp.type = tp match { + case NoType => MaxFunctionArityError(tree); tp + case _ => tp + } + + + /** Eta expand an expression like `m _`, where `m` denotes a method or a by-name argument + * + * The spec says: + * The expression `$e$ _` is well-formed if $e$ is of method type or if $e$ is a call-by-name parameter. + * (1) If $e$ is a method with parameters, `$e$ _` represents $e$ converted to a function type + * by [eta expansion](#eta-expansion). + * (2) If $e$ is a parameterless method or call-by-name parameter of type `=>$T$`, `$e$ _` represents + * the function of type `() => $T$`, which evaluates $e$ when it is applied to the empty parameterlist `()`. + */ + def typedEta(methodValue: Tree): Tree = methodValue.tpe match { + case tp@(MethodType(_, _) | PolyType(_, MethodType(_, _))) => // (1) + val formals = tp.params + if (isFunctionType(pt) || samMatchesFunctionBasedOnArity(samOf(pt), formals)) methodValue + else adapt(methodValue, mode, checkArity(methodValue)(functionTypeWildcard(formals.length))) + + case TypeRef(_, ByNameParamClass, _) | NullaryMethodType(_) => // (2) + val pos = methodValue.pos + // must create it here to change owner (normally done by typed's typedFunction) + val funSym = context.owner.newAnonymousFunctionValue(pos) + new ChangeOwnerTraverser(context.owner, funSym) traverse methodValue + + typed(Function(List(), methodValue) setSymbol funSym setPos pos, mode, pt) + case ErrorType => - expr1 + methodValue + case _ => - UnderscoreEtaError(expr1) + UnderscoreEtaError(methodValue) } def tryTypedArgs(args: List[Tree], mode: Mode): Option[List[Tree]] = { @@ -4471,7 +4454,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper case Annotated(_, r) => treesInResult(r) case If(_, t, e) => treesInResult(t) ++ treesInResult(e) case Try(b, catches, _) => treesInResult(b) ++ catches - case Typed(r, Function(Nil, EmptyTree)) => treesInResult(r) + case Typed(r, Function(Nil, EmptyTree)) => treesInResult(r) // a method value case Select(qual, name) => treesInResult(qual) case Apply(fun, args) => treesInResult(fun) ++ args.flatMap(treesInResult) case TypeApply(fun, args) => treesInResult(fun) ++ args.flatMap(treesInResult) @@ -4490,7 +4473,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper tryTypedArgs(args, forArgMode(fun, mode)) match { case Some(args1) if !args1.exists(arg => arg.exists(_.isErroneous)) => val qual1 = - if (!pt.isError) adaptToArguments(qual, name, args1, pt, reportAmbiguous = true, saveErrors = true) + if (!pt.isError) adaptToArguments(qual, name, args1, pt) else qual if (qual1 ne qual) { val tree1 = Apply(Select(qual1, name) setPos fun.pos, args1) setPos tree.pos @@ -4717,7 +4700,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper // member. Added `| PATTERNmode` to allow enrichment in patterns (so we can add e.g., an // xml member to StringContext, which in turn has an unapply[Seq] method) if (name != nme.CONSTRUCTOR && mode.inAny(EXPRmode | PATTERNmode)) { - val qual1 = adaptToMemberWithArgs(tree, qual, name, mode, reportAmbiguous = true, saveErrors = true) + val qual1 = adaptToMemberWithArgs(tree, qual, name, mode) if ((qual1 ne qual) && !qual1.isErrorTyped) return typed(treeCopy.Select(tree, qual1, name), mode, pt) } @@ -5111,11 +5094,11 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper // because `expr` might contain nested macro calls (see SI-6673) // // Note: apparently `Function(Nil, EmptyTree)` is the secret parser marker - // which means trailing underscore. + // which means trailing underscore -- denoting a method value. See makeMethodValue in TreeBuilder. case Typed(expr, Function(Nil, EmptyTree)) => typed1(suppressMacroExpansion(expr), mode, pt) match { case macroDef if treeInfo.isMacroApplication(macroDef) => MacroEtaError(macroDef) - case exprTyped => typedEta(checkDead(exprTyped)) + case methodValue => typedEta(checkDead(methodValue)) } case Typed(expr, tpt) => val tpt1 = typedType(tpt, mode) // type the ascribed type first @@ -5206,17 +5189,23 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper case MethodType(p :: _, _) => p.isImplicit // implicit method requires no args case _ => true // catches all others including NullaryMethodType } - def isPlausible(m: Symbol) = m.alternatives exists (m => requiresNoArgs(m.info)) + def isPlausible(m: Symbol) = !m.isPackage && m.alternatives.exists(x => requiresNoArgs(x.info)) def maybeWarn(s: String): Unit = { def warn(message: String) = context.warning(lit.pos, s"possible missing interpolator: $message") def suspiciousSym(name: TermName) = context.lookupSymbol(name, _ => true).symbol - def suspiciousExpr = InterpolatorCodeRegex findFirstIn s + val suspiciousExprs = InterpolatorCodeRegex findAllMatchIn s def suspiciousIdents = InterpolatorIdentRegex findAllIn s map (s => suspiciousSym(TermName(s drop 1))) - - if (suspiciousExpr.nonEmpty) - warn("detected an interpolated expression") // "${...}" - else + def isCheapIdent(expr: String) = (Character.isJavaIdentifierStart(expr.charAt(0)) && + expr.tail.forall(Character.isJavaIdentifierPart)) + def warnableExpr(expr: String) = !expr.isEmpty && (!isCheapIdent(expr) || isPlausible(suspiciousSym(TermName(expr)))) + + if (suspiciousExprs.nonEmpty) { + val exprs = (suspiciousExprs map (_ group 1)).toList + // short-circuit on leading ${} + if (!exprs.head.isEmpty && exprs.exists(warnableExpr)) + warn("detected an interpolated expression") // "${...}" + } else suspiciousIdents find isPlausible foreach (sym => warn(s"detected interpolated identifier `$$${sym.name}`")) // "$id" } lit match { diff --git a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala index ae6a9e22b6..9c4d521336 100644 --- a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala +++ b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala @@ -117,13 +117,15 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf => def transformDuringTyper(expr: Tree, mode: scala.reflect.internal.Mode, withImplicitViewsDisabled: Boolean, withMacrosDisabled: Boolean)(transform: (analyzer.Typer, Tree) => Tree): Tree = { def withWrapping(tree: Tree)(op: Tree => Tree) = if (mode == TERMmode) wrappingIntoTerm(tree)(op) else op(tree) - withWrapping(verify(expr))(expr1 => { + withWrapping(verify(expr)) { expr => // need to extract free terms, because otherwise you won't be able to typecheck macros against something that contains them - val exprAndFreeTerms = extractFreeTerms(expr1, wrapFreeTermRefs = false) - var expr2 = exprAndFreeTerms._1 - val freeTerms = exprAndFreeTerms._2 - val dummies = freeTerms.map{ case (freeTerm, name) => ValDef(NoMods, name, TypeTree(freeTerm.info), Select(Ident(PredefModule), newTermName("$qmark$qmark$qmark"))) }.toList - expr2 = Block(dummies, expr2) + val (extracted, freeTerms) = extractFreeTerms(expr, wrapFreeTermRefs = false) + val exprBound = { + val binders = freeTerms.toList.map { case (freeTerm, name) => + ValDef(NoMods, name, TypeTree(freeTerm.info), Select(Ident(PredefModule), newTermName("$qmark$qmark$qmark"))) + } + Block(binders, extracted) + } // !!! Why is this is in the empty package? If it's only to make // it inaccessible then please put it somewhere designed for that @@ -131,26 +133,29 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf => // [Eugene] how can we implement that? val ownerClass = rootMirror.EmptyPackageClass.newClassSymbol(newTypeName("<expression-owner>")) build.setInfo(ownerClass, ClassInfoType(List(ObjectTpe), newScope, ownerClass)) - val owner = ownerClass.newLocalDummy(expr2.pos) - val currentTyper = analyzer.newTyper(analyzer.rootContext(NoCompilationUnit, EmptyTree).make(expr2, owner)) - val withImplicitFlag = if (!withImplicitViewsDisabled) (currentTyper.context.withImplicitsEnabled[Tree] _) else (currentTyper.context.withImplicitsDisabled[Tree] _) - val withMacroFlag = if (!withMacrosDisabled) (currentTyper.context.withMacrosEnabled[Tree] _) else (currentTyper.context.withMacrosDisabled[Tree] _) - def withContext (tree: => Tree) = withImplicitFlag(withMacroFlag(tree)) + val owner = ownerClass.newLocalDummy(exprBound.pos) + val currentTyper = analyzer.newTyper(analyzer.rootContext(NoCompilationUnit, EmptyTree).make(exprBound, owner)) + import currentTyper.{context => currCtx} val run = new Run run.symSource(ownerClass) = NoAbstractFile // need to set file to something different from null, so that currentRun.defines works phase = run.typerPhase // need to set a phase to something <= typerPhase, otherwise implicits in typedSelect will be disabled globalPhase = run.typerPhase // amazing... looks like phase and globalPhase are different things, so we need to set them separately - currentTyper.context.initRootContext() // need to manually set context mode, otherwise typer.silent will throw exceptions + currCtx.initRootContext() // need to manually set context mode, otherwise typer.silent will throw exceptions reporter.reset() - val expr3 = withContext(transform(currentTyper, expr2)) - var (dummies1, result) = expr3 match { - case Block(dummies, result) => ((dummies, result)) - case result => ((Nil, result)) - } + val (binders, transformed) = + currCtx.withImplicits(enabled = !withImplicitViewsDisabled) { + currCtx.withMacros(enabled = !withMacrosDisabled) { + transform(currentTyper, exprBound) + } + } match { + case Block(binders, transformed) => (binders, transformed) + case transformed => (Nil, transformed) + } + val invertedIndex = freeTerms map (_.swap) - result = new Transformer { + val indexed = new Transformer { override def transform(tree: Tree): Tree = tree match { case Ident(name: TermName) if invertedIndex contains name => @@ -158,10 +163,10 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf => case _ => super.transform(tree) } - }.transform(result) - new TreeTypeSubstituter(dummies1 map (_.symbol), dummies1 map (dummy => SingleType(NoPrefix, invertedIndex(dummy.symbol.name.toTermName)))).traverse(result) - result - }) + }.transform(transformed) + new TreeTypeSubstituter(binders map (_.symbol), binders map (b => SingleType(NoPrefix, invertedIndex(b.symbol.name.toTermName)))).traverse(indexed) + indexed + } } def typecheck(expr: Tree, pt: Type, mode: scala.reflect.internal.Mode, silent: Boolean, withImplicitViewsDisabled: Boolean, withMacrosDisabled: Boolean): Tree = |