Linter Demo

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Warnings: 7

File: /home/fstrocco/Dart/dart/benchmark/compiler/lib/src/js_emitter/class_stub_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 ClassStubGenerator { final Namer namer; final Compiler compiler; final JavaScriptBackend backend; ClassStubGenerator(this.compiler, this.namer, this.backend); jsAst.Expression generateClassConstructor(ClassElement classElement, Iterable<String> fields) { // TODO(sra): Implement placeholders in VariableDeclaration position: // // String constructorName = namer.getNameOfClass(classElement); // return js.statement('function #(#) { #; }', // [ constructorName, fields, // fields.map( // (name) => js('this.# = #', [name, name]))])); return js('function(#) { #; this.#();}', [fields, fields.map((name) => js('this.# = #', [name, name])), namer.deferredAction]); } jsAst.Expression generateGetter(Element member, String fieldName) { ClassElement cls = member.enclosingClass; String receiver = backend.isInterceptorClass(cls) ? 'receiver' : 'this'; List<String> args = backend.isInterceptedMethod(member) ? ['receiver'] : []; return js('function(#) { return #.# }', [args, receiver, fieldName]); } jsAst.Expression generateSetter(Element member, String fieldName) { ClassElement cls = member.enclosingClass; String receiver = backend.isInterceptorClass(cls) ? 'receiver' : 'this'; List<String> args = backend.isInterceptedMethod(member) ? ['receiver'] : []; // TODO(floitsch): remove 'return'? return js('function(#, v) { return #.# = v; }', [args, receiver, fieldName]); } /** * Documentation wanted -- johnniwinther * * Invariant: [member] must be a declaration element. */ Map<String, jsAst.Expression> generateCallStubsForGetter( Element member, Set<Selector> selectors) { assert(invariant(member, member.isDeclaration)); // If the method is intercepted, the stub gets the // receiver explicitely and we need to pass it to the getter call. bool isInterceptedMethod = backend.isInterceptedMethod(member); bool isInterceptorClass = backend.isInterceptorClass(member.enclosingClass); const String receiverArgumentName = r'$receiver'; jsAst.Expression buildGetter() { jsAst.Expression receiver = js(isInterceptorClass ? receiverArgumentName : 'this'); if (member.isGetter) { String getterName = namer.getterForElement(member); if (isInterceptedMethod) { return js('this.#(#)', [getterName, receiver]); } return js('#.#()', [receiver, getterName]); } else { String fieldName = namer.instanceFieldPropertyName(member); return js('#.#', [receiver, fieldName]); } } Map<String, jsAst.Expression> generatedStubs = <String, jsAst.Expression>{}; // Two selectors may match but differ only in type. To avoid generating // identical stubs for each we track untyped selectors which already have // stubs. Set<Selector> generatedSelectors = new Set<Selector>(); for (Selector selector in selectors) { if (selector.applies(member, compiler.world)) { selector = selector.asUntyped; if (generatedSelectors.contains(selector)) continue; generatedSelectors.add(selector); String invocationName = namer.invocationName(selector); Selector callSelector = new Selector.callClosureFrom(selector); String closureCallName = namer.invocationName(callSelector); List<jsAst.Parameter> parameters = <jsAst.Parameter>[]; List<jsAst.Expression> arguments = <jsAst.Expression>[]; if (isInterceptedMethod) { parameters.add(new jsAst.Parameter(receiverArgumentName)); } for (int i = 0; i < selector.argumentCount; i++) { String name = 'arg$i'; parameters.add(new jsAst.Parameter(name)); arguments.add(js('#', name)); } jsAst.Fun function = js( 'function(#) { return #.#(#); }', [ parameters, buildGetter(), closureCallName, arguments]); generatedStubs[invocationName] = function; } } return generatedStubs; } Map<String, Selector> computeSelectorsForNsmHandlers() { Map<String, Selector> jsNames = <String, Selector>{}; // Do not generate no such method handlers if there is no class. if (compiler.codegenWorld.directlyInstantiatedClasses.isEmpty) { return jsNames; } void addNoSuchMethodHandlers(String ignore, Set<Selector> selectors) { TypeMask objectSubclassTypeMask = new TypeMask.subclass(compiler.objectClass, compiler.world); for (Selector selector in selectors) { TypeMask mask = selector.mask; if (mask == null) mask = objectSubclassTypeMask; if (!mask.needsNoSuchMethodHandling(selector, compiler.world)) { continue; } String jsName = namer.invocationMirrorInternalName(selector); jsNames[jsName] = selector; } } compiler.codegenWorld.invokedNames.forEach(addNoSuchMethodHandlers); compiler.codegenWorld.invokedGetters.forEach(addNoSuchMethodHandlers); compiler.codegenWorld.invokedSetters.forEach(addNoSuchMethodHandlers); return jsNames; } StubMethod generateStubForNoSuchMethod(String name, Selector selector) { // Values match JSInvocationMirror in js-helper library. int type = selector.invocationMirrorKind; List<String> parameterNames = new List.generate(selector.argumentCount, (i) => '\$$i'); List<jsAst.Expression> argNames = selector.callStructure.getOrderedNamedArguments().map((String name) => js.string(name)).toList(); String methodName = selector.invocationMirrorMemberName; String internalName = namer.invocationMirrorInternalName(selector); assert(backend.isInterceptedName(Compiler.NO_SUCH_METHOD)); jsAst.Expression expression = js('''this.#noSuchMethodName(this, #createInvocationMirror(#methodName, #internalName, #type, #arguments, #namedArguments))''', {'noSuchMethodName': namer.noSuchMethodName, 'createInvocationMirror': backend.emitter.staticFunctionAccess( backend.getCreateInvocationMirror()), 'methodName': js.string(compiler.enableMinification ? internalName : methodName), 'internalName': js.string(internalName), 'type': js.number(type), 'arguments': new jsAst.ArrayInitializer(parameterNames.map(js).toList()), 'namedArguments': new jsAst.ArrayInitializer(argNames)}); jsAst.Expression function; if (backend.isInterceptedName(selector.name)) { function = js(r'function($receiver, #) { return # }', [parameterNames, expression]); } else { function = js(r'function(#) { return # }', [parameterNames, expression]); } return new StubMethod(name, function); } } /// Creates two JavaScript functions: `tearOffGetter` and `tearOff`. /// /// `tearOffGetter` is internal and only used by `tearOff`. /// /// `tearOff` takes the following arguments: /// * `funcs`: a list of functions. These are the functions representing the /// member that is torn off. There can be more than one, since a member /// can have several stubs. /// Each function must have the `$callName` property set. /// * `reflectionInfo`: contains reflective information, and the function /// type. TODO(floitsch): point to where this is specified. /// * `isStatic`. /// * `name`. /// * `isIntercepted. List<jsAst.Statement> buildTearOffCode(JavaScriptBackend backend) { Namer namer = backend.namer; Compiler compiler = backend.compiler; Element closureFromTearOff = backend.findHelper('closureFromTearOff'); String tearOffAccessText; jsAst.Expression tearOffAccessExpression; String tearOffGlobalObjectName; String tearOffGlobalObject; if (closureFromTearOff != null) { // We need both the AST that references [closureFromTearOff] and a string // for the NoCsp version that constructs a function. tearOffAccessExpression = backend.emitter.staticFunctionAccess(closureFromTearOff); tearOffAccessText = jsAst.prettyPrint(tearOffAccessExpression, compiler).getText(); tearOffGlobalObjectName = tearOffGlobalObject = namer.globalObjectFor(closureFromTearOff); } else { // Default values for mocked-up test libraries. tearOffAccessText = r'''function() { throw 'Helper \'closureFromTearOff\' missing.' }'''; tearOffAccessExpression = js(tearOffAccessText); tearOffGlobalObjectName = 'MissingHelperFunction'; tearOffGlobalObject = '($tearOffAccessText())'; } jsAst.Statement tearOffGetter; if (!compiler.useContentSecurityPolicy) { // This template is uncached because it is constructed from code fragments // that can change from compilation to compilation. Some of these could be // avoided, except for the string literals that contain the compiled access // path to 'closureFromTearOff'. tearOffGetter = js.uncachedStatementTemplate(''' function tearOffGetter(funcs, reflectionInfo, name, isIntercepted) { return isIntercepted ? new Function("funcs", "reflectionInfo", "name", "$tearOffGlobalObjectName", "c", "return function tearOff_" + name + (functionCounter++) + "(x) {" + "if (c === null) c = $tearOffAccessText(" + "this, funcs, reflectionInfo, false, [x], name);" + "return new c(this, funcs[0], x, name);" + "}")(funcs, reflectionInfo, name, $tearOffGlobalObject, null) : new Function("funcs", "reflectionInfo", "name", "$tearOffGlobalObjectName", "c", "return function tearOff_" + name + (functionCounter++)+ "() {" + "if (c === null) c = $tearOffAccessText(" + "this, funcs, reflectionInfo, false, [], name);" + "return new c(this, funcs[0], null, name);" + "}")(funcs, reflectionInfo, name, $tearOffGlobalObject, null); }''').instantiate([]); } else { tearOffGetter = js.statement(''' function tearOffGetter(funcs, reflectionInfo, name, isIntercepted) { var cache = null; return isIntercepted ? function(x) { if (cache === null) cache = #( this, funcs, reflectionInfo, false, [x], name); return new cache(this, funcs[0], x, name); } : function() { if (cache === null) cache = #( this, funcs, reflectionInfo, false, [], name); return new cache(this, funcs[0], null, name); }; }''', [tearOffAccessExpression, tearOffAccessExpression]); } jsAst.Statement tearOff = js.statement(''' function tearOff(funcs, reflectionInfo, isStatic, name, isIntercepted) { var cache; return isStatic ? function() { if (cache === void 0) cache = #tearOff( this, funcs, reflectionInfo, true, [], name).prototype; return cache; } : tearOffGetter(funcs, reflectionInfo, name, isIntercepted); }''', {'tearOff': tearOffAccessExpression}); return <jsAst.Statement>[tearOffGetter, tearOff]; }