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File: /home/fstrocco/Dart/dart/benchmark/compiler/lib/src/js_emitter/runtime_type_generator.dart

// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file // for details. All rights reserved. Use of this source code is governed by a // BSD-style license that can be found in the LICENSE file. part of dart2js.js_emitter; class TypeTestProperties { /// The index of the function type into the metadata. /// /// If the class doesn't have a function type this field is `null`. /// /// If the is tests were generated with `storeFunctionTypeInMetadata` set to /// `false`, this field is `null`, and the [properties] contain a property /// that encodes the function type. int functionTypeIndex; /// The properties that must be installed on the prototype of the /// JS constructor of the [ClassElement] for which the is checks were /// generated. final Map<String, jsAst.Node> properties = <String, jsAst.Node>{}; } class RuntimeTypeGenerator { final Compiler compiler; final CodeEmitterTask emitterTask; final Namer namer; RuntimeTypeGenerator(this.compiler, this.emitterTask, this.namer); JavaScriptBackend get backend => compiler.backend; TypeTestRegistry get typeTestRegistry => emitterTask.typeTestRegistry; Set<ClassElement> get checkedClasses => typeTestRegistry.checkedClasses; Iterable<ClassElement> get classesUsingTypeVariableTests => typeTestRegistry.classesUsingTypeVariableTests; Set<FunctionType> get checkedFunctionTypes => typeTestRegistry.checkedFunctionTypes; /// Generates all properties necessary for is-checks on the [classElement]. /// /// Returns an instance of [TypeTestProperties] that contains the properties /// that must be installed on the prototype of the JS constructor of the /// [classElement]. /// /// If [storeFunctionTypeInMetadata] is `true`, stores the reified function /// type (if class has one) in the metadata object and stores its index in /// the result. This is only possible for function types that do not contain /// type variables. TypeTestProperties generateIsTests( ClassElement classElement, { bool storeFunctionTypeInMetadata: true}) { assert(invariant(classElement, classElement.isDeclaration)); TypeTestProperties result = new TypeTestProperties(); /// Generates an is-test if the test is not inherited from a superclass /// This assumes that for every class an is-tests is generated /// dynamically at runtime. We also always generate tests against /// native classes. /// TODO(herhut): Generate tests for native classes dynamically, as well. void generateIsTest(Element other) { if (classElement.isNative || !classElement.isSubclassOf(other)) { result.properties[namer.operatorIs(other)] = js('1'); } } void generateFunctionTypeSignature(FunctionElement method, FunctionType type) { assert(method.isImplementation); jsAst.Expression thisAccess = new jsAst.This(); Node node = method.node; ClosureClassMap closureData = compiler.closureToClassMapper.closureMappingCache[node]; if (closureData != null) { ClosureFieldElement thisLocal = closureData.freeVariableMap[closureData.thisLocal]; if (thisLocal != null) { String thisName = namer.instanceFieldPropertyName(thisLocal); thisAccess = js('this.#', thisName); } } if (storeFunctionTypeInMetadata && !type.containsTypeVariables) { result.functionTypeIndex = emitterTask.metadataCollector.reifyType(type); } else { RuntimeTypes rti = backend.rti; jsAst.Expression encoding = rti.getSignatureEncoding(type, thisAccess); String operatorSignature = namer.operatorSignature; result.properties[operatorSignature] = encoding; } } void generateSubstitution(ClassElement cls, {bool emitNull: false}) { if (cls.typeVariables.isEmpty) return; RuntimeTypes rti = backend.rti; jsAst.Expression expression; bool needsNativeCheck = emitterTask.nativeEmitter.requiresNativeIsCheck(cls); expression = rti.getSupertypeSubstitution(classElement, cls); if (expression == null && (emitNull || needsNativeCheck)) { expression = new jsAst.LiteralNull(); } if (expression != null) { result.properties[namer.substitutionName(cls)] = expression; } } void generateTypeCheck(TypeCheck check) { ClassElement checkedClass = check.cls; generateIsTest(checkedClass); Substitution substitution = check.substitution; if (substitution != null) { jsAst.Expression body = substitution.getCode(backend.rti); result.properties[namer.substitutionName(checkedClass)] = body; } } _generateIsTestsOn(classElement, generateIsTest, generateFunctionTypeSignature, generateSubstitution, generateTypeCheck); return result; } /** * Generate "is tests" for [cls] itself, and the "is tests" for the * classes it implements and type argument substitution functions for these * tests. We don't need to add the "is tests" of the super class because * they will be inherited at runtime, but we may need to generate the * substitutions, because they may have changed. */ void _generateIsTestsOn( ClassElement cls, void generateIsTest(Element element), FunctionTypeSignatureEmitter generateFunctionTypeSignature, SubstitutionEmitter generateSubstitution, void emitTypeCheck(TypeCheck check)) { Setlet<Element> generated = new Setlet<Element>(); if (checkedClasses.contains(cls)) { generateIsTest(cls); generateSubstitution(cls); generated.add(cls); } // Precomputed is checks. TypeChecks typeChecks = backend.rti.requiredChecks; Iterable<TypeCheck> classChecks = typeChecks[cls]; if (classChecks != null) { for (TypeCheck check in classChecks) { if (!generated.contains(check.cls)) { emitTypeCheck(check); generated.add(check.cls); } } } RuntimeTypes rti = backend.rti; ClassElement superclass = cls.superclass; bool haveSameTypeVariables(ClassElement a, ClassElement b) { if (a.isClosure) return true; return backend.rti.isTrivialSubstitution(a, b); } if (superclass != null && superclass != compiler.objectClass && !haveSameTypeVariables(cls, superclass)) { // We cannot inherit the generated substitutions, because the type // variable layout for this class is different. Instead we generate // substitutions for all checks and make emitSubstitution a NOP for the // rest of this function. // TODO(karlklose): move the computation of these checks to // RuntimeTypeInformation. while (superclass != null) { if (backend.classNeedsRti(superclass)) { generateSubstitution(superclass, emitNull: true); generated.add(superclass); } superclass = superclass.superclass; } for (DartType supertype in cls.allSupertypes) { ClassElement superclass = supertype.element; if (generated.contains(superclass)) continue; if (classesUsingTypeVariableTests.contains(superclass) || checkedClasses.contains(superclass)) { // Generate substitution. If no substitution is necessary, emit // `null` to overwrite a (possibly) existing substitution from the // super classes. generateSubstitution(superclass, emitNull: true); } } void emitNothing(_, {emitNull}) {}; generateSubstitution = emitNothing; } // A class that defines a `call` method implicitly implements // [Function] and needs checks for all typedefs that are used in is-checks. if (checkedClasses.contains(compiler.functionClass) || checkedFunctionTypes.isNotEmpty) { Element call = cls.lookupLocalMember(Compiler.CALL_OPERATOR_NAME); if (call == null) { // If [cls] is a closure, it has a synthetic call operator method. call = cls.lookupBackendMember(Compiler.CALL_OPERATOR_NAME); } if (call != null && call.isFunction) { // A superclass might already implement the Function interface. In such // a case, we can avoid emiting the is test here. if (!cls.superclass.implementsFunction(compiler)) { _generateInterfacesIsTests(compiler.functionClass, generateIsTest, generateSubstitution, generated); } FunctionType callType = call.computeType(compiler); generateFunctionTypeSignature(call, callType); } } for (DartType interfaceType in cls.interfaces) { _generateInterfacesIsTests(interfaceType.element, generateIsTest, generateSubstitution, generated); } } /** * Generate "is tests" where [cls] is being implemented. */ void _generateInterfacesIsTests(ClassElement cls, void generateIsTest(ClassElement element), SubstitutionEmitter generateSubstitution, Set<Element> alreadyGenerated) { void tryEmitTest(ClassElement check) { if (!alreadyGenerated.contains(check) && checkedClasses.contains(check)) { alreadyGenerated.add(check); generateIsTest(check); generateSubstitution(check); } }; tryEmitTest(cls); for (DartType interfaceType in cls.interfaces) { Element element = interfaceType.element; tryEmitTest(element); _generateInterfacesIsTests(element, generateIsTest, generateSubstitution, alreadyGenerated); } // We need to also emit "is checks" for the superclass and its supertypes. ClassElement superclass = cls.superclass; if (superclass != null) { tryEmitTest(superclass); _generateInterfacesIsTests(superclass, generateIsTest, generateSubstitution, alreadyGenerated); } } List<StubMethod> generateTypeVariableReaderStubs(ClassElement classElement) { List<StubMethod> stubs = <StubMethod>[]; List typeVariables = []; ClassElement superclass = classElement; while (superclass != null) { for (TypeVariableType parameter in superclass.typeVariables) { if (backend.emitter.readTypeVariables.contains(parameter.element)) { stubs.add( _generateTypeVariableReader(classElement, parameter.element)); } } superclass = superclass.superclass; } return stubs; } StubMethod _generateTypeVariableReader(ClassElement cls, TypeVariableElement element) { String name = namer.nameForReadTypeVariable(element); int index = RuntimeTypes.getTypeVariableIndex(element); jsAst.Expression computeTypeVariable; Substitution substitution = backend.rti.computeSubstitution( cls, element.typeDeclaration, alwaysGenerateFunction: true); if (substitution != null) { computeTypeVariable = js(r'#.apply(null, this.$builtinTypeInfo)', substitution.getCodeForVariable(index, backend.rti)); } else { // TODO(ahe): These can be generated dynamically. computeTypeVariable = js(r'this.$builtinTypeInfo && this.$builtinTypeInfo[#]', js.number(index)); } jsAst.Expression convertRtiToRuntimeType = backend.emitter .staticFunctionAccess(backend.findHelper('convertRtiToRuntimeType')); return new StubMethod(name, js('function () { return #(#) }', [convertRtiToRuntimeType, computeTypeVariable])); } }