dart/pkg/compiler/lib/src/js_emitter/class_stub_generator.dart - external/dart - Git at Google

 // 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.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];
 }
	// 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.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];
	}