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dart / sdk.git / f084cea80bcc92525177a0220e5ea1c79912d0ba / . / sdk / lib / _internal / compiler / implementation / js_backend / emitter.dart
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// Copyright (c) 2012, 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 js_backend;
/**
* A function element that represents a closure call. The signature is copied
* from the given element.
*/
class ClosureInvocationElement extends FunctionElementX {
ClosureInvocationElement(SourceString name,
FunctionElement other)
: super.from(name, other, other.enclosingElement),
methodElement = other;
isInstanceMember() => true;
Element getOutermostEnclosingMemberOrTopLevel() => methodElement;
/**
* The [member] this invocation refers to.
*/
Element methodElement;
}
/**
* A convenient type alias for some functions that emit keyed values.
*/
typedef void DefineStubFunction(String invocationName, jsAst.Expression value);
/**
* A data structure for collecting fragments of a class definition.
*/
class ClassBuilder {
final List<jsAst.Property> properties = <jsAst.Property>[];
// Has the same signature as [DefineStubFunction].
void addProperty(String name, jsAst.Expression value) {
properties.add(new jsAst.Property(js.string(name), value));
}
jsAst.Expression toObjectInitializer() {
return new jsAst.ObjectInitializer(properties);
}
}
/**
* Generates the code for all used classes in the program. Static fields (even
* in classes) are ignored, since they can be treated as non-class elements.
*
* The code for the containing (used) methods must exist in the [:universe:].
*/
class CodeEmitterTask extends CompilerTask {
bool needsInheritFunction = false;
bool needsDefineClass = false;
bool needsClosureClass = false;
bool needsLazyInitializer = false;
final Namer namer;
ConstantEmitter constantEmitter;
NativeEmitter nativeEmitter;
CodeBuffer mainBuffer;
final CodeBuffer deferredBuffer = new CodeBuffer();
/** Shorter access to [isolatePropertiesName]. Both here in the code, as
well as in the generated code. */
String isolateProperties;
String classesCollector;
final Set<ClassElement> neededClasses = new Set<ClassElement>();
final List<ClassElement> regularClasses = <ClassElement>[];
final List<ClassElement> deferredClasses = <ClassElement>[];
final List<ClassElement> nativeClasses = <ClassElement>[];
// TODO(ngeoffray): remove this field.
Set<ClassElement> instantiatedClasses;
final List<jsAst.Expression> boundClosures = <jsAst.Expression>[];
JavaScriptBackend get backend => compiler.backend;
String get _ => compiler.enableMinification ? "" : " ";
String get n => compiler.enableMinification ? "" : "\n";
String get N => compiler.enableMinification ? "\n" : ";\n";
/**
* A cache of closures that are used to closurize instance methods.
* A closure is dynamically bound to the instance used when
* closurized.
*/
final Map<int, String> boundClosureCache;
/**
* A cache of closures that are used to closurize instance methods
* of interceptors. These closures are dynamically bound to the
* interceptor instance, and the actual receiver of the method.
*/
final Map<int, String> interceptorClosureCache;
/**
* Raw ClassElement symbols occuring in is-checks and type assertions. If the
* program contains parameterized checks `x is Set<int>` and
* `x is Set<String>` then the ClassElement `Set` will occur once in
* [checkedClasses].
*/
Set<ClassElement> checkedClasses;
/**
* Raw Typedef symbols occuring in is-checks and type assertions. If the
* program contains `x is F<int>` and `x is F<bool>` then the TypedefElement
* `F` will occur once in [checkedTypedefs].
*/
Set<TypedefElement> checkedTypedefs;
final bool generateSourceMap;
Iterable<ClassElement> cachedClassesUsingTypeVariableTests;
Iterable<ClassElement> get classesUsingTypeVariableTests {
if (cachedClassesUsingTypeVariableTests == null) {
cachedClassesUsingTypeVariableTests = compiler.codegenWorld.isChecks
.where((DartType t) => t is TypeVariableType)
.map((TypeVariableType v) => v.element.getEnclosingClass())
.toList();
}
return cachedClassesUsingTypeVariableTests;
}
CodeEmitterTask(Compiler compiler, Namer namer, this.generateSourceMap)
: mainBuffer = new CodeBuffer(),
this.namer = namer,
boundClosureCache = new Map<int, String>(),
interceptorClosureCache = new Map<int, String>(),
constantEmitter = new ConstantEmitter(compiler, namer),
super(compiler) {
nativeEmitter = new NativeEmitter(this);
}
void addComment(String comment, CodeBuffer buffer) {
buffer.add(jsAst.prettyPrint(js.comment(comment), compiler));
}
void computeRequiredTypeChecks() {
assert(checkedClasses == null && checkedTypedefs == null);
compiler.codegenWorld.addImplicitChecks(classesUsingTypeVariableTests);
checkedClasses = new Set<ClassElement>();
checkedTypedefs = new Set<TypedefElement>();
compiler.codegenWorld.isChecks.forEach((DartType t) {
if (t is InterfaceType) {
checkedClasses.add(t.element);
} else if (t is TypedefType) {
checkedTypedefs.add(t.element);
}
});
}
jsAst.Expression constantReference(Constant value) {
return constantEmitter.reference(value);
}
jsAst.Expression constantInitializerExpression(Constant value) {
return constantEmitter.initializationExpression(value);
}
String get name => 'CodeEmitter';
String get currentGenerateAccessorName
=> '${namer.CURRENT_ISOLATE}.\$generateAccessor';
String get generateAccessorHolder
=> '$isolatePropertiesName.\$generateAccessor';
String get finishClassesProperty
=> r'$finishClasses';
String get finishClassesName
=> '${namer.isolateName}.$finishClassesProperty';
String get finishIsolateConstructorName
=> '${namer.isolateName}.\$finishIsolateConstructor';
String get isolatePropertiesName
=> '${namer.isolateName}.${namer.isolatePropertiesName}';
String get supportsProtoName
=> 'supportsProto';
String get lazyInitializerName
=> '${namer.isolateName}.\$lazy';
// Property name suffixes. If the accessors are renaming then the format
// is <accessorName>:<fieldName><suffix>. We use the suffix to know whether
// to look for the ':' separator in order to avoid doing the indexOf operation
// on every single property (they are quite rare). None of these characters
// are legal in an identifier and they are related by bit patterns.
// setter < 0x3c
// both = 0x3d
// getter > 0x3e
// renaming setter | 0x7c
// renaming both } 0x7d
// renaming getter ~ 0x7e
const SUFFIX_MASK = 0x3f;
const FIRST_SUFFIX_CODE = 0x3c;
const SETTER_CODE = 0x3c;
const GETTER_SETTER_CODE = 0x3d;
const GETTER_CODE = 0x3e;
const RENAMING_FLAG = 0x40;
String needsGetterCode(String variable) => '($variable & 3) > 0';
String needsSetterCode(String variable) => '($variable & 2) == 0';
String isRenaming(String variable) => '($variable & $RENAMING_FLAG) != 0';
jsAst.FunctionDeclaration get generateAccessorFunction {
// function generateAccessor(field, prototype) {
jsAst.Fun fun = js.fun(['field', 'prototype'], [
js['var len = field.length'],
js['var lastCharCode = field.charCodeAt(len - 1)'],
js['var needsAccessor = '
'(lastCharCode & $SUFFIX_MASK) >= $FIRST_SUFFIX_CODE'],
// if (needsAccessor) {
js.if_('needsAccessor', [
js['var needsGetter = ${needsGetterCode("lastCharCode")}'],
js['var needsSetter = ${needsSetterCode("lastCharCode")}'],
js['var renaming = ${isRenaming("lastCharCode")}'],
js['var accessorName = field = field.substring(0, len - 1)'],
// if (renaming) {
js.if_('renaming', [
js['var divider = field.indexOf(":")'],
js['accessorName = field.substring(0, divider)'],
js['field = field.substring(divider + 1)']
]),
// if (needsGetter) {
js.if_('needsGetter', [
js['var getterString = "return this." + field'],
js['prototype["${namer.getterPrefix}" + accessorName] = '
'new Function(getterString)']
]),
// if (needsSetter) {
js.if_('needsSetter', [
// var setterString = "this." + field + " = v;";
js['var setterString = "this." + field + "$_=${_}v"'],
js['prototype["${namer.setterPrefix}" + accessorName] = '
'new Function("v", setterString)']
]),
]),
// return field;
js.return_('field')
]);
return new jsAst.FunctionDeclaration(
new jsAst.VariableDeclaration('generateAccessor'),
fun);
}
List get defineClassFunction {
// First the class name, then the field names in an array and the members
// (inside an Object literal).
// The caller can also pass in the constructor as a function if needed.
//
// Example:
// defineClass("A", ["x", "y"], {
// foo$1: function(y) {
// print(this.x + y);
// },
// bar$2: function(t, v) {
// this.x = t - v;
// },
// });
// function(cls, fields, prototype) {
var defineClass = js.fun(['cls', 'fields', 'prototype'], [
js['var constructor'],
// if (typeof fields == "function") {
js.if_(js['typeof fields == "function"'], [
js['constructor = fields']
], /* else */ [
js['var str = "function " + cls + "("'],
js['var body = ""'],
// for (var i = 0; i < fields.length; i++) {
js.for_(js['var i = 0'], js['i < fields.length'], js['i++'], [
// if (i != 0) str += ", ";
js.if_(js['i != 0'], js['str += ", "']),
js['var field = fields[i]'],
js['field = generateAccessor(field, prototype)'],
js['str += field'],
js['body += ("this." + field + " = " + field + ";\\n")']
]),
js['str += (") {" + body + "}\\nreturn " + cls)'],
js['constructor = (new Function(str))()']
]),
js['constructor.prototype = prototype'],
js['constructor.builtin\$cls = cls'],
// return constructor;
js.return_('constructor')
]);
// Declare a function called "generateAccessor". This is used in
// defineClassFunction (it's a local declaration in init()).
return [
generateAccessorFunction,
js['$generateAccessorHolder = generateAccessor'],
new jsAst.FunctionDeclaration(
new jsAst.VariableDeclaration('defineClass'), defineClass) ];
}
/** Needs defineClass to be defined. */
List buildProtoSupportCheck() {
// On Firefox and Webkit browsers we can manipulate the __proto__
// directly. Opera claims to have __proto__ support, but it is buggy.
// So we have to do more checks.
// Opera bug was filed as DSK-370158, and fixed as CORE-47615
// (http://my.opera.com/desktopteam/blog/2012/07/20/more-12-01-fixes).
// If the browser does not support __proto__ we need to instantiate an
// object with the correct (internal) prototype set up correctly, and then
// copy the members.
// TODO(8541): Remove this work around.
return [
js['var $supportsProtoName = false'],
js['var tmp = (defineClass("c", ["f?"], {})).prototype'],
js.if_(js['tmp.__proto__'], [
js['tmp.__proto__ = {}'],
js.if_(js[r'typeof tmp.get$f != "undefined"'],
js['$supportsProtoName = true'])
])
];
}
jsAst.Fun get finishClassesFunction {
// Class descriptions are collected in a JS object.
// 'finishClasses' takes all collected descriptions and sets up
// the prototype.
// Once set up, the constructors prototype field satisfy:
// - it contains all (local) members.
// - its internal prototype (__proto__) points to the superclass'
// prototype field.
// - the prototype's constructor field points to the JavaScript
// constructor.
// For engines where we have access to the '__proto__' we can manipulate
// the object literal directly. For other engines we have to create a new
// object and copy over the members.
// function(collectedClasses,
// isolateProperties,
// existingIsolateProperties) {
return js.fun(['collectedClasses', 'isolateProperties',
'existingIsolateProperties'], [
js['var pendingClasses = {}'],
js['var hasOwnProperty = Object.prototype.hasOwnProperty'],
// for (var cls in collectedClasses) {
js.forIn('cls', 'collectedClasses', [
// if (hasOwnProperty.call(collectedClasses, cls)) {
js.if_(js['hasOwnProperty.call(collectedClasses, cls)'], [
js['var desc = collectedClasses[cls]'],
/* The 'fields' are either a constructor function or a
* string encoding fields, constructor and superclass. Get
* the superclass and the fields in the format
* Super;field1,field2 from the null-string property on the
* descriptor.
*/
// var fields = desc[""], supr;
js['var fields = desc[""], supr'],
js.if_(js['typeof fields == "string"'], [
js['var s = fields.split(";")'],
js['supr = s[0]'],
js['fields = s[1] == "" ? [] : s[1].split(",")'],
], /* else */ [
js['supr = desc.super']
]),
js['isolateProperties[cls] = defineClass(cls, fields, desc)'],
// if (supr) pendingClasses[cls] = supr;
js.if_(js['supr'], js['pendingClasses[cls] = supr'])
])
]),
js['var finishedClasses = {}'],
// function finishClass(cls) { ... }
buildFinishClass(),
// for (var cls in pendingClasses) finishClass(cls);
js.forIn('cls', 'pendingClasses', js['finishClass']('cls'))
]);
}
jsAst.FunctionDeclaration buildFinishClass() {
// function finishClass(cls) {
jsAst.Fun fun = js.fun(['cls'], [
// TODO(8540): Remove this work around.
/* Opera does not support 'getOwnPropertyNames'. Therefore we use
hasOwnProperty instead. */
js['var hasOwnProperty = Object.prototype.hasOwnProperty'],
// if (hasOwnProperty.call(finishedClasses, cls)) return;
js.if_(js['hasOwnProperty.call(finishedClasses, cls)'],
js.return_()),
js['finishedClasses[cls] = true'],
js['var superclass = pendingClasses[cls]'],
/* The superclass is only false (empty string) for Dart's Object class. */
js.if_(js['!superclass'], js.return_()),
js['finishClass(superclass)'],
js['var constructor = isolateProperties[cls]'],
js['var superConstructor = isolateProperties[superclass]'],
// if (!superConstructor)
// superConstructor = existingIsolateProperties[superclass];
js.if_(js['superConstructor'].not,
js['superConstructor'].assign(
js['existingIsolateProperties'][js['superclass']])),
js['var prototype = constructor.prototype'],
// if ($supportsProtoName) {
js.if_(supportsProtoName, [
js['prototype.__proto__ = superConstructor.prototype'],
js['prototype.constructor = constructor'],
], /* else */ [
// function tmp() {};
new jsAst.FunctionDeclaration(
new jsAst.VariableDeclaration('tmp'),
js.fun([], [])),
js['tmp.prototype = superConstructor.prototype'],
js['var newPrototype = new tmp()'],
js['constructor.prototype = newPrototype'],
js['newPrototype.constructor = constructor'],
// for (var member in prototype) {
js.forIn('member', 'prototype', [
/* Short version of: if (member == '') */
// if (!member) continue;
js.if_(js['!member'], new jsAst.Continue(null)),
// if (hasOwnProperty.call(prototype, member)) {
js.if_(js['hasOwnProperty.call(prototype, member)'], [
js['newPrototype[member] = prototype[member]']
])
])
])
]);
return new jsAst.FunctionDeclaration(
new jsAst.VariableDeclaration('finishClass'),
fun);
}
jsAst.Fun get finishIsolateConstructorFunction {
String isolate = namer.isolateName;
// We replace the old Isolate function with a new one that initializes
// all its field with the initial (and often final) value of all globals.
// This has two advantages:
// 1. the properties are in the object itself (thus avoiding to go through
// the prototype when looking up globals.
// 2. a new isolate goes through a (usually well optimized) constructor
// function of the form: "function() { this.x = ...; this.y = ...; }".
//
// Example: If [isolateProperties] is an object containing: x = 3 and
// A = function A() { /* constructor of class A. */ }, then we generate:
// str = "{
// var isolateProperties = Isolate.$isolateProperties;
// this.x = isolateProperties.x;
// this.A = isolateProperties.A;
// }";
// which is then dynamically evaluated:
// var newIsolate = new Function(str);
//
// We also copy over old values like the prototype, and the
// isolateProperties themselves.
List copyFinishClasses = [];
if (needsDefineClass) {
copyFinishClasses.add(
// newIsolate.$finishClasses = oldIsolate.$finishClasses;
js['newIsolate'][finishClassesProperty].assign(
js['oldIsolate'][finishClassesProperty]));
}
// function(oldIsolate) {
return js.fun('oldIsolate', [
js['var isolateProperties = oldIsolate.${namer.isolatePropertiesName}'],
js[r'isolateProperties.$currentScript ='
'typeof document == "object" ?'
'(document.currentScript ||'
'document.scripts[document.scripts.length - 1]) :'
'null'],
js['var isolatePrototype = oldIsolate.prototype'],
js['var str = "{\\n"'],
js['str += '
'"var properties = $isolate.${namer.isolatePropertiesName};\\n"'],
js['var hasOwnProperty = Object.prototype.hasOwnProperty'],
// for (var staticName in isolateProperties) {
js.forIn('staticName', 'isolateProperties', [
js.if_(js['hasOwnProperty.call(isolateProperties, staticName)'], [
js['str += ("this." + staticName + "= properties." + staticName + '
'";\\n")']
])
]),
js['str += "}\\n"'],
js['var newIsolate = new Function(str)'],
js['newIsolate.prototype = isolatePrototype'],
js['isolatePrototype.constructor = newIsolate'],
js['newIsolate.${namer.isolatePropertiesName} = isolateProperties'],
]..addAll(copyFinishClasses)
..addAll([
// return newIsolate;
js.return_('newIsolate')
]));
}
jsAst.Fun get lazyInitializerFunction {
String isolate = namer.CURRENT_ISOLATE;
// function(prototype, staticName, fieldName, getterName, lazyValue) {
var parameters = <String>['prototype', 'staticName', 'fieldName',
'getterName', 'lazyValue'];
return js.fun(parameters, [
js['var getter = new Function("{ return $isolate." + fieldName + ";}")'],
]..addAll(addLazyInitializerLogic())
);
}
List addLazyInitializerLogic() {
String isolate = namer.CURRENT_ISOLATE;
String cyclicThrow = namer.isolateAccess(backend.getCyclicThrowHelper());
return [
js['var sentinelUndefined = {}'],
js['var sentinelInProgress = {}'],
js['prototype[fieldName] = sentinelUndefined'],
// prototype[getterName] = function() {
js['prototype'][js['getterName']].assign(js.fun([], [
js['var result = $isolate[fieldName]'],
// try {
js.try_([
js.if_(js['result === sentinelUndefined'], [
js['$isolate[fieldName] = sentinelInProgress'],
// try {
js.try_([
js['result = $isolate[fieldName] = lazyValue()'],
], finallyPart: [
// Use try-finally, not try-catch/throw as it destroys the
// stack trace.
// if (result === sentinelUndefined) {
js.if_(js['result === sentinelUndefined'], [
// if ($isolate[fieldName] === sentinelInProgress) {
js.if_(js['$isolate[fieldName] === sentinelInProgress'], [
js['$isolate[fieldName] = null'],
])
])
])
], /* else */ [
js.if_(js['result === sentinelInProgress'],
js['$cyclicThrow(staticName)']
)
]),
// return result;
js.return_('result')
], finallyPart: [
js['$isolate[getterName] = getter']
])
]))
];
}
List buildDefineClassAndFinishClassFunctionsIfNecessary() {
if (!needsDefineClass) return [];
return defineClassFunction
..addAll(buildProtoSupportCheck())
..addAll([
js[finishClassesName].assign(finishClassesFunction)
]);
}
List buildLazyInitializerFunctionIfNecessary() {
if (!needsLazyInitializer) return [];
// $lazyInitializerName = $lazyInitializerFunction
return [js[lazyInitializerName].assign(lazyInitializerFunction)];
}
List buildFinishIsolateConstructor() {
return [
// $finishIsolateConstructorName = $finishIsolateConstructorFunction
js[finishIsolateConstructorName].assign(finishIsolateConstructorFunction)
];
}
void emitFinishIsolateConstructorInvocation(CodeBuffer buffer) {
String isolate = namer.isolateName;
buffer.add("$isolate = $finishIsolateConstructorName($isolate)$N");
}
/**
* Generate stubs to handle invocation of methods with optional
* arguments.
*
* A method like [: foo([x]) :] may be invoked by the following
* calls: [: foo(), foo(1), foo(x: 1) :]. See the sources of this
* function for detailed examples.
*/
void addParameterStub(FunctionElement member,
Selector selector,
DefineStubFunction defineStub,
Set<String> alreadyGenerated) {
FunctionSignature parameters = member.computeSignature(compiler);
int positionalArgumentCount = selector.positionalArgumentCount;
if (positionalArgumentCount == parameters.parameterCount) {
assert(selector.namedArgumentCount == 0);
return;
}
if (parameters.optionalParametersAreNamed
&& selector.namedArgumentCount == parameters.optionalParameterCount) {
// If the selector has the same number of named arguments as
// the element, we don't need to add a stub. The call site will
// hit the method directly.
return;
}
ConstantHandler handler = compiler.constantHandler;
List<SourceString> names = selector.getOrderedNamedArguments();
String invocationName = namer.invocationName(selector);
if (alreadyGenerated.contains(invocationName)) return;
alreadyGenerated.add(invocationName);
bool isInterceptedMethod = backend.isInterceptedMethod(member);
// If the method is intercepted, we need to also pass
// the actual receiver.
int extraArgumentCount = isInterceptedMethod ? 1 : 0;
// Use '$receiver' to avoid clashes with other parameter names. Using
// '$receiver' works because [:namer.safeName:] used for getting parameter
// names never returns a name beginning with a single '$'.
String receiverArgumentName = r'$receiver';
// The parameters that this stub takes.
List<jsAst.Parameter> parametersBuffer =
new List<jsAst.Parameter>(selector.argumentCount + extraArgumentCount);
// The arguments that will be passed to the real method.
List<jsAst.Expression> argumentsBuffer =
new List<jsAst.Expression>(
parameters.parameterCount + extraArgumentCount);
int count = 0;
if (isInterceptedMethod) {
count++;
parametersBuffer[0] = new jsAst.Parameter(receiverArgumentName);
argumentsBuffer[0] = js[receiverArgumentName];
}
int indexOfLastOptionalArgumentInParameters = positionalArgumentCount - 1;
TreeElements elements =
compiler.enqueuer.resolution.getCachedElements(member);
parameters.orderedForEachParameter((Element element) {
String jsName = backend.namer.safeName(element.name.slowToString());
assert(jsName != receiverArgumentName);
int optionalParameterStart = positionalArgumentCount + extraArgumentCount;
if (count < optionalParameterStart) {
parametersBuffer[count] = new jsAst.Parameter(jsName);
argumentsBuffer[count] = js[jsName];
} else {
int index = names.indexOf(element.name);
if (index != -1) {
indexOfLastOptionalArgumentInParameters = count;
// The order of the named arguments is not the same as the
// one in the real method (which is in Dart source order).
argumentsBuffer[count] = js[jsName];
parametersBuffer[optionalParameterStart + index] =
new jsAst.Parameter(jsName);
// Note that [elements] may be null for a synthesized [member].
} else if (elements != null && elements.isParameterChecked(element)) {
argumentsBuffer[count] = constantReference(SentinelConstant.SENTINEL);
} else {
Constant value = handler.initialVariableValues[element];
if (value == null) {
argumentsBuffer[count] = constantReference(new NullConstant());
} else {
if (!value.isNull()) {
// If the value is the null constant, we should not pass it
// down to the native method.
indexOfLastOptionalArgumentInParameters = count;
}
argumentsBuffer[count] = constantReference(value);
}
}
}
count++;
});
List body;
if (member.hasFixedBackendName()) {
body = nativeEmitter.generateParameterStubStatements(
member, invocationName, parametersBuffer, argumentsBuffer,
indexOfLastOptionalArgumentInParameters);
} else {
body = [js.return_(js['this'][namer.getName(member)](argumentsBuffer))];
}
jsAst.Fun function = js.fun(parametersBuffer, body);
defineStub(invocationName, function);
}
void addParameterStubs(FunctionElement member,
DefineStubFunction defineStub) {
// We fill the lists depending on the selector. For example,
// take method foo:
// foo(a, b, {c, d});
//
// We may have multiple ways of calling foo:
// (1) foo(1, 2);
// (2) foo(1, 2, c: 3);
// (3) foo(1, 2, d: 4);
// (4) foo(1, 2, c: 3, d: 4);
// (5) foo(1, 2, d: 4, c: 3);
//
// What we generate at the call sites are:
// (1) foo$2(1, 2);
// (2) foo$3$c(1, 2, 3);
// (3) foo$3$d(1, 2, 4);
// (4) foo$4$c$d(1, 2, 3, 4);
// (5) foo$4$c$d(1, 2, 3, 4);
//
// The stubs we generate are (expressed in Dart):
// (1) foo$2(a, b) => foo$4$c$d(a, b, null, null)
// (2) foo$3$c(a, b, c) => foo$4$c$d(a, b, c, null);
// (3) foo$3$d(a, b, d) => foo$4$c$d(a, b, null, d);
// (4) No stub generated, call is direct.
// (5) No stub generated, call is direct.
// Keep a cache of which stubs have already been generated, to
// avoid duplicates. Note that even if selectors are
// canonicalized, we would still need this cache: a typed selector
// on A and a typed selector on B could yield the same stub.
Set<String> generatedStubNames = new Set<String>();
if (compiler.enabledFunctionApply
&& member.name == namer.closureInvocationSelectorName) {
// If [Function.apply] is called, we pessimistically compile all
// possible stubs for this closure.
FunctionSignature signature = member.computeSignature(compiler);
Set<Selector> selectors = signature.optionalParametersAreNamed
? computeNamedSelectors(signature, member)
: computeOptionalSelectors(signature, member);
for (Selector selector in selectors) {
addParameterStub(member, selector, defineStub, generatedStubNames);
}
} else {
Set<Selector> selectors = compiler.codegenWorld.invokedNames[member.name];
if (selectors == null) return;
for (Selector selector in selectors) {
if (!selector.applies(member, compiler)) continue;
addParameterStub(member, selector, defineStub, generatedStubNames);
}
}
}
/**
* Compute the set of possible selectors in the presence of named
* parameters.
*/
Set<Selector> computeNamedSelectors(FunctionSignature signature,
FunctionElement element) {
Set<Selector> selectors = new Set<Selector>();
// Add the selector that does not have any optional argument.
selectors.add(new Selector(SelectorKind.CALL,
element.name,
element.getLibrary(),
signature.requiredParameterCount,
<SourceString>[]));
// For each optional parameter, we iterator over the set of
// already computed selectors and create new selectors with that
// parameter now being passed.
signature.forEachOptionalParameter((Element element) {
Set<Selector> newSet = new Set<Selector>();
selectors.forEach((Selector other) {
List<SourceString> namedArguments = [element.name];
namedArguments.addAll(other.namedArguments);
newSet.add(new Selector(other.kind,
other.name,
other.library,
other.argumentCount + 1,
namedArguments));
});
selectors.addAll(newSet);
});
return selectors;
}
/**
* Compute the set of possible selectors in the presence of optional
* non-named parameters.
*/
Set<Selector> computeOptionalSelectors(FunctionSignature signature,
FunctionElement element) {
Set<Selector> selectors = new Set<Selector>();
// Add the selector that does not have any optional argument.
selectors.add(new Selector(SelectorKind.CALL,
element.name,
element.getLibrary(),
signature.requiredParameterCount,
<SourceString>[]));
// For each optional parameter, we increment the number of passed
// argument.
for (int i = 1; i <= signature.optionalParameterCount; i++) {
selectors.add(new Selector(SelectorKind.CALL,
element.name,
element.getLibrary(),
signature.requiredParameterCount + i,
<SourceString>[]));
}
return selectors;
}
bool instanceFieldNeedsGetter(Element member) {
assert(member.isField());
if (fieldAccessNeverThrows(member)) return false;
return compiler.codegenWorld.hasInvokedGetter(member, compiler);
}
bool instanceFieldNeedsSetter(Element member) {
assert(member.isField());
if (fieldAccessNeverThrows(member)) return false;
return (!member.modifiers.isFinalOrConst())
&& compiler.codegenWorld.hasInvokedSetter(member, compiler);
}
// We never access a field in a closure (a captured variable) without knowing
// that it is there. Therefore we don't need to use a getter (that will throw
// if the getter method is missing), but can always access the field directly.
static bool fieldAccessNeverThrows(Element element) {
return element is ClosureFieldElement;
}
String compiledFieldName(Element member) {
assert(member.isField());
return member.hasFixedBackendName()
? member.fixedBackendName()
: namer.getName(member);
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [member] must be a declaration element.
*/
void addInstanceMember(Element member, ClassBuilder builder) {
assert(invariant(member, member.isDeclaration));
// TODO(floitsch): we don't need to deal with members of
// uninstantiated classes, that have been overwritten by subclasses.
if (member.isFunction()
|| member.isGenerativeConstructorBody()
|| member.isAccessor()) {
if (member.isAbstract(compiler)) return;
jsAst.Expression code = backend.generatedCode[member];
if (code == null) return;
builder.addProperty(namer.getName(member), code);
code = backend.generatedBailoutCode[member];
if (code != null) {
builder.addProperty(namer.getBailoutName(member), code);
}
FunctionElement function = member;
FunctionSignature parameters = function.computeSignature(compiler);
if (!parameters.optionalParameters.isEmpty) {
addParameterStubs(member, builder.addProperty);
}
} else if (!member.isField()) {
compiler.internalError('unexpected kind: "${member.kind}"',
element: member);
}
emitExtraAccessors(member, builder);
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [classElement] must be a declaration element.
*/
void emitInstanceMembers(ClassElement classElement,
ClassBuilder builder) {
assert(invariant(classElement, classElement.isDeclaration));
void visitMember(ClassElement enclosing, Element member) {
assert(invariant(classElement, member.isDeclaration));
if (member.isInstanceMember()) {
addInstanceMember(member, builder);
}
}
// TODO(kasperl): We should make sure to only emit one version of
// overridden methods. Right now, we rely on the ordering so the
// methods pulled in from mixins are replaced with the members
// from the class definition.
// If the class is a native class, we have to add the instance
// members defined in the non-native mixin applications used by
// the class.
visitNativeMixins(classElement, (MixinApplicationElement mixin) {
mixin.forEachMember(
visitMember,
includeBackendMembers: true,
includeSuperMembers: false);
});
classElement.implementation.forEachMember(
visitMember,
includeBackendMembers: true,
includeSuperMembers: false);
void generateIsTest(Element other) {
jsAst.Expression code;
if (other == compiler.objectClass && other != classElement) {
// Avoid emitting [:$isObject:] on all classes but [Object].
return;
}
if (nativeEmitter.requiresNativeIsCheck(other)) {
code = js.fun([], [js.return_(true)]);
} else {
code = new jsAst.LiteralBool(true);
}
builder.addProperty(namer.operatorIs(other), code);
}
void generateSubstitution(Element other, {bool emitNull: false}) {
RuntimeTypeInformation rti = backend.rti;
// TODO(karlklose): support typedefs with variables.
jsAst.Expression expression;
bool needsNativeCheck = nativeEmitter.requiresNativeIsCheck(other);
if (other.kind == ElementKind.CLASS) {
String substitution = rti.getSupertypeSubstitution(classElement, other,
alwaysGenerateFunction: true);
if (substitution != null) {
expression = new jsAst.LiteralExpression(substitution);
} else if (emitNull || needsNativeCheck) {
expression = new jsAst.LiteralNull();
}
}
if (expression != null) {
if (needsNativeCheck) {
expression = js.fun([], js.return_(expression));
}
builder.addProperty(namer.substitutionName(other), expression);
}
}
generateIsTestsOn(classElement, generateIsTest, generateSubstitution);
if (identical(classElement, compiler.objectClass)
&& compiler.enabledNoSuchMethod) {
// Emit the noSuchMethod handlers on the Object prototype now,
// so that the code in the dynamicFunction helper can find
// them. Note that this helper is invoked before analyzing the
// full JS script.
if (!nativeEmitter.handleNoSuchMethod) {
emitNoSuchMethodHandlers(builder.addProperty);
}
}
if (backend.isInterceptorClass(classElement)
&& classElement != compiler.objectClass) {
// We optimize the operator== on interceptor classes to
// just do a JavaScript double or triple equals.
String name = backend.namer.publicInstanceMethodNameByArity(
const SourceString('=='), 1);
Function kind = (classElement == backend.jsNullClass)
? js.equals
: js.strictEquals;
builder.addProperty(name, js.fun(['receiver', 'a'],
js.block(js.return_(kind(js['receiver'], js['a'])))));
}
}
void emitRuntimeTypeSupport(CodeBuffer buffer) {
RuntimeTypeInformation rti = backend.rti;
TypeChecks typeChecks = rti.getRequiredChecks();
/// Classes that are not instantiated and native classes need a holder
/// object for their checks, because there will be no class defined for
/// them.
bool needsHolder(ClassElement cls) {
return !neededClasses.contains(cls) || cls.isNative() ||
rti.isJsNative(cls);
}
/**
* Generates a holder object if it is needed. A holder is a JavaScript
* object literal with a field [builtin$cls] that contains the name of the
* class as a string (just like object constructors do). The is-checks for
* the class are are added to the holder object later.
*/
void maybeGenerateHolder(ClassElement cls) {
if (!needsHolder(cls)) return;
String holder = namer.isolateAccess(cls);
String name = namer.getName(cls);
buffer.add('$holder$_=$_{builtin\$cls:$_"$name"');
buffer.add('}$N');
}
// Create representation objects for classes that we do not have a class
// definition for (because they are uninstantiated or native).
for (ClassElement cls in rti.allArguments) {
maybeGenerateHolder(cls);
}
// Add checks to the constructors of instantiated classes or to the created
// holder object.
for (ClassElement cls in typeChecks) {
String holder = namer.isolateAccess(cls);
for (ClassElement check in typeChecks[cls]) {
buffer.add('$holder.${namer.operatorIs(check)}$_=${_}true$N');
String body = rti.getSupertypeSubstitution(cls, check);
if (body != null) {
buffer.add('$holder.${namer.substitutionName(check)}$_=${_}$body$N');
}
};
}
}
void visitNativeMixins(ClassElement classElement,
void visit(MixinApplicationElement mixinApplication)) {
if (!classElement.isNative()) return;
// Use recursion to make sure to visit the superclasses before the
// subclasses. Once we start keeping track of the emitted fields
// and members, we're going to want to visit these in the other
// order so we get the most specialized definition first.
void recurse(ClassElement cls) {
if (cls == null || !cls.isMixinApplication) return;
recurse(cls.superclass);
assert(!cls.isNative());
visit(cls);
}
recurse(classElement.superclass);
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [classElement] must be a declaration element.
*/
void visitClassFields(ClassElement classElement,
void addField(Element member,
String name,
String accessorName,
bool needsGetter,
bool needsSetter,
bool needsCheckedSetter)) {
assert(invariant(classElement, classElement.isDeclaration));
// If the class is never instantiated we still need to set it up for
// inheritance purposes, but we can simplify its JavaScript constructor.
bool isInstantiated =
compiler.codegenWorld.instantiatedClasses.contains(classElement);
void visitField(ClassElement enclosingClass, Element member) {
assert(invariant(classElement, member.isDeclaration));
LibraryElement library = member.getLibrary();
SourceString name = member.name;
bool isPrivate = name.isPrivate();
// Keep track of whether or not we're dealing with a field mixin
// into a native class.
bool isMixinNativeField =
classElement.isNative() && enclosingClass.isMixinApplication;
// See if we can dynamically create getters and setters.
// We can only generate getters and setters for [classElement] since
// the fields of super classes could be overwritten with getters or
// setters.
bool needsGetter = false;
bool needsSetter = false;
// We need to name shadowed fields differently, so they don't clash with
// the non-shadowed field.
bool isShadowed = false;
if (isMixinNativeField || identical(enclosingClass, classElement)) {
needsGetter = instanceFieldNeedsGetter(member);
needsSetter = instanceFieldNeedsSetter(member);
} else {
isShadowed = classElement.isShadowedByField(member);
}
if ((isInstantiated && !enclosingClass.isNative())
|| needsGetter
|| needsSetter) {
String accessorName = isShadowed
? namer.shadowedFieldName(member)
: namer.getName(member);
String fieldName = member.hasFixedBackendName()
? member.fixedBackendName()
: (isMixinNativeField ? member.name.slowToString() : accessorName);
bool needsCheckedSetter = false;
if (needsSetter) {
if (compiler.enableTypeAssertions
&& canGenerateCheckedSetter(member)) {
needsCheckedSetter = true;
needsSetter = false;
} else if (backend.isInterceptedMethod(member)) {
// The [addField] will take care of generating the setter.
needsSetter = false;
}
}
// Getters and setters with suffixes will be generated dynamically.
addField(member,
fieldName,
accessorName,
needsGetter,
needsSetter,
needsCheckedSetter);
}
}
// TODO(kasperl): We should make sure to only emit one version of
// overridden fields. Right now, we rely on the ordering so the
// fields pulled in from mixins are replaced with the fields from
// the class definition.
// If the class is a native class, we have to add the fields
// defined in the non-native mixin applications used by the class.
visitNativeMixins(classElement, (MixinApplicationElement mixin) {
mixin.forEachInstanceField(
visitField,
includeBackendMembers: true,
includeSuperMembers: false);
});
// If a class is not instantiated then we add the field just so we can
// generate the field getter/setter dynamically. Since this is only
// allowed on fields that are in [classElement] we don't need to visit
// superclasses for non-instantiated classes.
classElement.implementation.forEachInstanceField(
visitField,
includeBackendMembers: true,
includeSuperMembers: isInstantiated && !classElement.isNative());
}
void generateGetter(Element member, String fieldName, String accessorName,
ClassBuilder builder) {
assert(!backend.isInterceptorClass(member));
String getterName = namer.getterNameFromAccessorName(accessorName);
builder.addProperty(getterName,
js.fun([], js.return_(js['this'][fieldName])));
}
void generateSetter(Element member, String fieldName, String accessorName,
ClassBuilder builder) {
assert(!backend.isInterceptorClass(member));
String setterName = namer.setterNameFromAccessorName(accessorName);
List<String> args = backend.isInterceptedMethod(member)
? ['receiver', 'v']
: ['v'];
builder.addProperty(setterName,
js.fun(args, js['this'][fieldName].assign('v')));
}
bool canGenerateCheckedSetter(Element member) {
DartType type = member.computeType(compiler);
if (type.element.isTypeVariable()
|| type.element == compiler.dynamicClass
|| type.element == compiler.objectClass) {
// TODO(ngeoffray): Support type checks on type parameters.
return false;
}
return true;
}
void generateCheckedSetter(Element member,
String fieldName,
String accessorName,
ClassBuilder builder) {
assert(canGenerateCheckedSetter(member));
DartType type = member.computeType(compiler);
// TODO(ahe): Generate a dynamic type error here.
if (type.element.isErroneous()) return;
FunctionElement helperElement
= backend.getCheckedModeHelper(type, typeCast: false);
String helperName = namer.isolateAccess(helperElement);
List<jsAst.Expression> arguments = <jsAst.Expression>[js['v']];
if (helperElement.computeSignature(compiler).parameterCount != 1) {
arguments.add(js.string(namer.operatorIs(type.element)));
}
String setterName = namer.setterNameFromAccessorName(accessorName);
List<String> args = backend.isInterceptedMethod(member)
? ['receiver', 'v']
: ['v'];
builder.addProperty(setterName,
js.fun(args, js['this'][fieldName].assign(js[helperName](arguments))));
}
void emitClassConstructor(ClassElement classElement, ClassBuilder builder) {
/* Do nothing. */
}
void emitSuper(String superName, ClassBuilder builder) {
/* Do nothing. */
}
void emitClassFields(ClassElement classElement,
ClassBuilder builder,
{ String superClass: "",
bool classIsNative: false }) {
bool isFirstField = true;
StringBuffer buffer = new StringBuffer();
if (!classIsNative) {
buffer.write('$superClass;');
}
visitClassFields(classElement, (Element member,
String name,
String accessorName,
bool needsGetter,
bool needsSetter,
bool needsCheckedSetter) {
// Ignore needsCheckedSetter - that is handled below.
bool needsAccessor = (needsGetter || needsSetter);
// We need to output the fields for non-native classes so we can auto-
// generate the constructor. For native classes there are no
// constructors, so we don't need the fields unless we are generating
// accessors at runtime.
if (!classIsNative || needsAccessor) {
// Emit correct commas.
if (isFirstField) {
isFirstField = false;
} else {
buffer.write(',');
}
int flag = 0;
if (!needsAccessor) {
// Emit field for constructor generation.
assert(!classIsNative);
buffer.write(name);
} else {
// Emit (possibly renaming) field name so we can add accessors at
// runtime.
buffer.write(accessorName);
if (name != accessorName) {
buffer.write(':$name');
// Only the native classes can have renaming accessors.
assert(classIsNative);
flag = RENAMING_FLAG;
}
}
if (needsGetter && needsSetter) {
buffer.writeCharCode(GETTER_SETTER_CODE + flag);
} else if (needsGetter) {
buffer.writeCharCode(GETTER_CODE + flag);
} else if (needsSetter) {
buffer.writeCharCode(SETTER_CODE + flag);
}
}
});
String compactClassData = buffer.toString();
if (compactClassData.length > 0) {
builder.addProperty('', js.string(compactClassData));
}
}
void emitClassGettersSetters(ClassElement classElement,
ClassBuilder builder) {
visitClassFields(classElement, (Element member,
String name,
String accessorName,
bool needsGetter,
bool needsSetter,
bool needsCheckedSetter) {
compiler.withCurrentElement(member, () {
if (needsCheckedSetter) {
assert(!needsSetter);
generateCheckedSetter(member, name, accessorName, builder);
}
if (backend.isInterceptedMethod(member)
&& instanceFieldNeedsSetter(member)) {
// The caller of this method sets [needsSetter] as false
// when the setter is intercepted.
assert(!needsSetter);
generateSetter(member, name, accessorName, builder);
}
if (!getterAndSetterCanBeImplementedByFieldSpec) {
if (needsGetter) {
generateGetter(member, name, accessorName, builder);
}
if (needsSetter) {
generateSetter(member, name, accessorName, builder);
}
}
});
});
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [classElement] must be a declaration element.
*/
void generateClass(ClassElement classElement, CodeBuffer buffer) {
assert(invariant(classElement, classElement.isDeclaration));
assert(invariant(classElement, !classElement.isNative()));
needsDefineClass = true;
String className = namer.getName(classElement);
// Find the first non-native superclass.
ClassElement superclass = classElement.superclass;
while (superclass != null && superclass.isNative()) {
superclass = superclass.superclass;
}
String superName = "";
if (superclass != null) {
superName = namer.getName(superclass);
}
ClassBuilder builder = new ClassBuilder();
emitClassConstructor(classElement, builder);
emitSuper(superName, builder);
emitClassFields(classElement, builder,
superClass: superName, classIsNative: false);
emitClassGettersSetters(classElement, builder);
emitInstanceMembers(classElement, builder);
jsAst.Expression init =
js[classesCollector][className].assign(builder.toObjectInitializer());
buffer.add(jsAst.prettyPrint(init, compiler));
buffer.add('$N$n');
}
bool get getterAndSetterCanBeImplementedByFieldSpec => true;
int _selectorRank(Selector selector) {
int arity = selector.argumentCount * 3;
if (selector.isGetter()) return arity + 2;
if (selector.isSetter()) return arity + 1;
return arity;
}
int _compareSelectorNames(Selector selector1, Selector selector2) {
String name1 = selector1.name.toString();
String name2 = selector2.name.toString();
if (name1 != name2) return Comparable.compare(name1, name2);
return _selectorRank(selector1) - _selectorRank(selector2);
}
Iterable<Element> getTypedefChecksOn(DartType type) {
bool isSubtype(TypedefElement typedef) {
FunctionType typedefType =
typedef.computeType(compiler).unalias(compiler);
return compiler.types.isSubtype(type, typedefType);
}
return checkedTypedefs.where(isSubtype).toList()
..sort(Elements.compareByPosition);
}
/**
* 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 emitIsTest(Element element),
void emitSubstitution(Element element, {emitNull})) {
if (checkedClasses.contains(cls)) {
emitIsTest(cls);
emitSubstitution(cls);
}
RuntimeTypeInformation rti = backend.rti;
ClassElement superclass = cls.superclass;
bool haveSameTypeVariables(ClassElement a, ClassElement b) {
if (a.isClosure()) return true;
return a.typeVariables == b.typeVariables;
}
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.
Set<ClassElement> emitted = new Set<ClassElement>();
// TODO(karlklose): move the computation of these checks to
// RuntimeTypeInformation.
if (compiler.world.needsRti(cls)) {
emitSubstitution(superclass, emitNull: true);
emitted.add(superclass);
}
for (DartType supertype in cls.allSupertypes) {
ClassElement superclass = supertype.element;
if (classesUsingTypeVariableTests.contains(superclass)) {
emitSubstitution(superclass, emitNull: true);
emitted.add(superclass);
}
for (ClassElement check in checkedClasses) {
if (supertype.element == check && !emitted.contains(check)) {
// Generate substitution. If no substitution is necessary, emit
// [:null:] to overwrite a (possibly) existing substitution from the
// super classes.
emitSubstitution(check, emitNull: true);
emitted.add(check);
}
}
}
void emitNothing(_, {emitNull}) {};
emitSubstitution = emitNothing;
}
Set<Element> generated = new Set<Element>();
// 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) ||
!checkedTypedefs.isEmpty) {
FunctionElement 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) {
generateInterfacesIsTests(compiler.functionClass,
emitIsTest,
emitSubstitution,
generated);
getTypedefChecksOn(call.computeType(compiler)).forEach(emitIsTest);
}
}
for (DartType interfaceType in cls.interfaces) {
generateInterfacesIsTests(interfaceType.element, emitIsTest,
emitSubstitution, generated);
}
// For native classes, we also have to run through their mixin
// applications and make sure we deal with 'is' tests correctly
// for those.
visitNativeMixins(cls, (MixinApplicationElement mixin) {
for (DartType interfaceType in mixin.interfaces) {
ClassElement interfaceElement = interfaceType.element;
generateInterfacesIsTests(interfaceType.element, emitIsTest,
emitSubstitution, generated);
}
});
}
/**
* Generate "is tests" where [cls] is being implemented.
*/
void generateInterfacesIsTests(ClassElement cls,
void emitIsTest(ClassElement element),
void emitSubstitution(ClassElement element),
Set<Element> alreadyGenerated) {
void tryEmitTest(ClassElement check) {
if (!alreadyGenerated.contains(check) && checkedClasses.contains(check)) {
alreadyGenerated.add(check);
emitIsTest(check);
emitSubstitution(check);
}
};
tryEmitTest(cls);
for (DartType interfaceType in cls.interfaces) {
Element element = interfaceType.element;
tryEmitTest(element);
generateInterfacesIsTests(element, emitIsTest, emitSubstitution,
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, emitIsTest, emitSubstitution,
alreadyGenerated);
}
}
/**
* Return a function that returns true if its argument is a class
* that needs to be emitted.
*/
Function computeClassFilter() {
Set<ClassElement> unneededClasses = new Set<ClassElement>();
// The [Bool] class is not marked as abstract, but has a factory
// constructor that always throws. We never need to emit it.
unneededClasses.add(compiler.boolClass);
// Go over specialized interceptors and then constants to know which
// interceptors are needed.
Set<ClassElement> needed = new Set<ClassElement>();
backend.specializedGetInterceptors.forEach(
(_, Collection<ClassElement> elements) {
needed.addAll(elements);
}
);
ConstantHandler handler = compiler.constantHandler;
List<Constant> constants = handler.getConstantsForEmission();
for (Constant constant in constants) {
if (constant is ConstructedConstant) {
Element element = constant.computeType(compiler).element;
if (backend.isInterceptorClass(element)) {
needed.add(element);
}
}
}
// Add unneeded interceptors to the [unneededClasses] set.
for (ClassElement interceptor in backend.interceptedClasses) {
if (!needed.contains(interceptor)
&& interceptor != compiler.objectClass) {
unneededClasses.add(interceptor);
}
}
return (ClassElement cls) => !unneededClasses.contains(cls);
}
void emitClosureClassIfNeeded(CodeBuffer buffer) {
// The closure class could have become necessary because of the generation
// of stubs.
ClassElement closureClass = compiler.closureClass;
if (needsClosureClass && !instantiatedClasses.contains(closureClass)) {
generateClass(closureClass, bufferForElement(closureClass, buffer));
}
}
void emitFinishClassesInvocationIfNecessary(CodeBuffer buffer) {
if (needsDefineClass) {
buffer.add('$finishClassesName($classesCollector,'
'$_$isolateProperties,'
'${_}null)$N');
// Reset the map.
buffer.add("$classesCollector$_=${_}null$N$n");
}
}
void emitStaticFunction(CodeBuffer buffer,
String name,
jsAst.Expression functionExpression) {
jsAst.Expression assignment =
js[isolateProperties][name].assign(functionExpression);
buffer.add(jsAst.prettyPrint(assignment, compiler));
buffer.add('$N$n');
}
void emitStaticFunctions(CodeBuffer eagerBuffer) {
bool isStaticFunction(Element element) =>
!element.isInstanceMember() && !element.isField();
Iterable<Element> elements =
backend.generatedCode.keys.where(isStaticFunction);
Set<Element> pendingElementsWithBailouts =
backend.generatedBailoutCode.keys
.where(isStaticFunction)
.toSet();
for (Element element in Elements.sortedByPosition(elements)) {
CodeBuffer buffer = bufferForElement(element, eagerBuffer);
jsAst.Expression code = backend.generatedCode[element];
emitStaticFunction(buffer, namer.getName(element), code);
jsAst.Expression bailoutCode = backend.generatedBailoutCode[element];
if (bailoutCode != null) {
pendingElementsWithBailouts.remove(element);
emitStaticFunction(buffer, namer.getBailoutName(element), bailoutCode);
}
}
// Is it possible the primary function was inlined but the bailout was not?
for (Element element in
Elements.sortedByPosition(pendingElementsWithBailouts)) {
CodeBuffer buffer = bufferForElement(element, eagerBuffer);
jsAst.Expression bailoutCode = backend.generatedBailoutCode[element];
emitStaticFunction(buffer, namer.getBailoutName(element), bailoutCode);
}
}
void emitStaticFunctionGetters(CodeBuffer buffer) {
Set<FunctionElement> functionsNeedingGetter =
compiler.codegenWorld.staticFunctionsNeedingGetter;
for (FunctionElement element in
Elements.sortedByPosition(functionsNeedingGetter)) {
// TODO(ahe): Defer loading of these getters.
// The static function does not have the correct name. Since
// [addParameterStubs] use the name to create its stubs we simply
// create a fake element with the correct name.
// Note: the callElement will not have any enclosingElement.
FunctionElement callElement =
new ClosureInvocationElement(namer.closureInvocationSelectorName,
element);
String staticName = namer.getName(element);
String invocationName = namer.instanceMethodName(callElement);
String fieldAccess = '$isolateProperties.$staticName';
buffer.add("$fieldAccess.$invocationName$_=$_$fieldAccess$N");
addParameterStubs(callElement, (String name, jsAst.Expression value) {
jsAst.Expression assignment =
js[isolateProperties][staticName][name].assign(value);
buffer.add(
jsAst.prettyPrint(assignment.toStatement(), compiler));
buffer.add('$N');
});
// If a static function is used as a closure we need to add its name
// in case it is used in spawnFunction.
String fieldName = namer.STATIC_CLOSURE_NAME_NAME;
buffer.add('$fieldAccess.$fieldName$_=$_"$staticName"$N');
getTypedefChecksOn(element.computeType(compiler)).forEach(
(Element typedef) {
String operator = namer.operatorIs(typedef);
buffer.add('$fieldAccess.$operator$_=${_}true$N');
}
);
}
}
void emitBoundClosureClassHeader(String mangledName,
String superName,
List<String> fieldNames,
ClassBuilder builder) {
builder.addProperty('',
js.string("$superName;${fieldNames.join(',')}"));
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [member] must be a declaration element.
*/
void emitDynamicFunctionGetter(FunctionElement member,
DefineStubFunction defineStub) {
assert(invariant(member, member.isDeclaration));
// For every method that has the same name as a property-get we create a
// getter that returns a bound closure. Say we have a class 'A' with method
// 'foo' and somewhere in the code there is a dynamic property get of
// 'foo'. Then we generate the following code (in pseudo Dart/JavaScript):
//
// class A {
// foo(x, y, z) { ... } // Original function.
// get foo { return new BoundClosure499(this, "foo"); }
// }
// class BoundClosure499 extends Closure {
// var self;
// BoundClosure499(this.self, this.name);
// $call3(x, y, z) { return self[name](x, y, z); }
// }
// TODO(floitsch): share the closure classes with other classes
// if they share methods with the same signature. Currently we do this only
// if there are no optional parameters. Closures with optional parameters
// are more difficult to canonicalize because they would need to have the
// same default values.
bool hasOptionalParameters = member.optionalParameterCount(compiler) != 0;
int parameterCount = member.parameterCount(compiler);
Map<int, String> cache;
String extraArg = null;
// Intercepted methods take an extra parameter, which is the
// receiver of the call.
bool inInterceptor = backend.isInterceptedMethod(member);
if (inInterceptor) {
cache = interceptorClosureCache;
extraArg = 'receiver';
} else {
cache = boundClosureCache;
}
List<String> fieldNames = compiler.enableMinification
? inInterceptor ? const ['a', 'b', 'c']
: const ['a', 'b']
: inInterceptor ? const ['self', 'target', 'receiver']
: const ['self', 'target'];
Iterable<Element> typedefChecks =
getTypedefChecksOn(member.computeType(compiler));
bool hasTypedefChecks = !typedefChecks.isEmpty;
bool canBeShared = !hasOptionalParameters && !hasTypedefChecks;
String closureClass = canBeShared ? cache[parameterCount] : null;
if (closureClass == null) {
// Either the class was not cached yet, or there are optional parameters.
// Create a new closure class.
String name;
if (canBeShared) {
if (inInterceptor) {
name = 'BoundClosure\$i${parameterCount}';
} else {
name = 'BoundClosure\$${parameterCount}';
}
} else {
name = 'Bound_${member.name.slowToString()}'
'_${member.enclosingElement.name.slowToString()}';
}
ClassElement closureClassElement = new ClosureClassElement(
new SourceString(name), compiler, member, member.getCompilationUnit());
String mangledName = namer.getName(closureClassElement);
String superName = namer.getName(closureClassElement.superclass);
needsClosureClass = true;
// Define the constructor with a name so that Object.toString can
// find the class name of the closure class.
ClassBuilder boundClosureBuilder = new ClassBuilder();
emitBoundClosureClassHeader(
mangledName, superName, fieldNames, boundClosureBuilder);
// Now add the methods on the closure class. The instance method does not
// have the correct name. Since [addParameterStubs] use the name to create
// its stubs we simply create a fake element with the correct name.
// Note: the callElement will not have any enclosingElement.
FunctionElement callElement =
new ClosureInvocationElement(namer.closureInvocationSelectorName,
member);
String invocationName = namer.instanceMethodName(callElement);
List<String> parameters = <String>[];
List<jsAst.Expression> arguments = <jsAst.Expression>[];
if (inInterceptor) {
arguments.add(js['this'][fieldNames[2]]);
}
for (int i = 0; i < parameterCount; i++) {
String name = 'p$i';
parameters.add(name);
arguments.add(js[name]);
}
jsAst.Expression fun = js.fun(
parameters,
js.return_(
js['this'][fieldNames[0]][js['this'][fieldNames[1]]](arguments)));
boundClosureBuilder.addProperty(invocationName, fun);
addParameterStubs(callElement, boundClosureBuilder.addProperty);
typedefChecks.forEach((Element typedef) {
String operator = namer.operatorIs(typedef);
boundClosureBuilder.addProperty(operator, new jsAst.LiteralBool(true));
});
boundClosures.add(
js[classesCollector][mangledName].assign(
boundClosureBuilder.toObjectInitializer()));
closureClass = namer.isolateAccess(closureClassElement);
// Cache it.
if (canBeShared) {
cache[parameterCount] = closureClass;
}
}
// And finally the getter.
String getterName = namer.getterName(member);
String targetName = namer.instanceMethodName(member);
List<String> parameters = <String>[];
List<jsAst.Expression> arguments = <jsAst.Expression>[];
arguments.add(js['this']);
arguments.add(js.string(targetName));
if (inInterceptor) {
parameters.add(extraArg);
arguments.add(js[extraArg]);
}
jsAst.Expression getterFunction = js.fun(
parameters,
js.return_(js[closureClass].newWith(arguments)));
defineStub(getterName, getterFunction);
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [member] must be a declaration element.
*/
void emitCallStubForGetter(Element member,
Set<Selector> selectors,
DefineStubFunction defineStub) {
assert(invariant(member, member.isDeclaration));
LibraryElement memberLibrary = member.getLibrary();
// If the method is intercepted, the stub gets the
// receiver explicitely and we need to pass it to the getter call.
bool isInterceptedMethod = backend.isInterceptedMethod(member);
const String receiverArgumentName = r'$receiver';
jsAst.Expression buildGetter() {
if (member.isGetter()) {
String getterName = namer.getterName(member);
return js['this'][getterName](
isInterceptedMethod
? <jsAst.Expression>[js[receiverArgumentName]]
: <jsAst.Expression>[]);
} else {
String fieldName = member.hasFixedBackendName()
? member.fixedBackendName()
: namer.instanceFieldName(member);
return js['this'][fieldName];
}
}
// 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)) {
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$i';
parameters.add(new jsAst.Parameter(name));
arguments.add(js[name]);
}
jsAst.Fun function = js.fun(
parameters,
js.return_(buildGetter()[closureCallName](arguments)));
defineStub(invocationName, function);
}
}
}
void emitStaticNonFinalFieldInitializations(CodeBuffer buffer) {
ConstantHandler handler = compiler.constantHandler;
Iterable<VariableElement> staticNonFinalFields =
handler.getStaticNonFinalFieldsForEmission();
for (Element element in Elements.sortedByPosition(staticNonFinalFields)) {
// [:interceptedNames:] is handled in [emitInterceptedNames].
if (element == backend.interceptedNames) continue;
compiler.withCurrentElement(element, () {
Constant initialValue = handler.getInitialValueFor(element);
jsAst.Expression init =
js[isolateProperties][namer.getName(element)].assign(
constantEmitter.referenceInInitializationContext(initialValue));
buffer.add(jsAst.prettyPrint(init, compiler));
buffer.add('$N');
});
}
}
void emitLazilyInitializedStaticFields(CodeBuffer buffer) {
ConstantHandler handler = compiler.constantHandler;
List<VariableElement> lazyFields =
handler.getLazilyInitializedFieldsForEmission();
if (!lazyFields.isEmpty) {
needsLazyInitializer = true;
for (VariableElement element in Elements.sortedByPosition(lazyFields)) {
assert(backend.generatedBailoutCode[element] == null);
jsAst.Expression code = backend.generatedCode[element];
assert(code != null);
// The code only computes the initial value. We build the lazy-check
// here:
// lazyInitializer(prototype, 'name', fieldName, getterName, initial);
// The name is used for error reporting. The 'initial' must be a
// closure that constructs the initial value.
List<jsAst.Expression> arguments = <jsAst.Expression>[];
arguments.add(js[isolateProperties]);
arguments.add(js.string(element.name.slowToString()));
arguments.add(js.string(namer.getName(element)));
arguments.add(js.string(namer.getLazyInitializerName(element)));
arguments.add(code);
jsAst.Expression getter = buildLazyInitializedGetter(element);
if (getter != null) {
arguments.add(getter);
}
jsAst.Expression init = js[lazyInitializerName](arguments);
buffer.add(jsAst.prettyPrint(init, compiler));
buffer.add("$N");
}
}
}
jsAst.Expression buildLazyInitializedGetter(VariableElement element) {
// Nothing to do, the 'lazy' function will create the getter.
return null;
}
void emitCompileTimeConstants(CodeBuffer eagerBuffer) {
ConstantHandler handler = compiler.constantHandler;
List<Constant> constants = handler.getConstantsForEmission();
bool addedMakeConstantList = false;
for (Constant constant in constants) {
// No need to emit functions. We already did that.
if (constant.isFunction()) continue;
// Numbers, strings and booleans are currently always inlined.
if (constant.isPrimitive()) continue;
String name = namer.constantName(constant);
// The name is null when the constant is already a JS constant.
// TODO(floitsch): every constant should be registered, so that we can
// share the ones that take up too much space (like some strings).
if (name == null) continue;
if (!addedMakeConstantList && constant.isList()) {
addedMakeConstantList = true;
emitMakeConstantList(eagerBuffer);
}
CodeBuffer buffer =
bufferForElement(constant.computeType(compiler).element, eagerBuffer);
jsAst.Expression init = js[isolateProperties][name].assign(
constantInitializerExpression(constant));
buffer.add(jsAst.prettyPrint(init, compiler));
buffer.add('$N');
}
}
void emitMakeConstantList(CodeBuffer buffer) {
buffer.add(namer.isolateName);
buffer.add(r'''.makeConstantList = function(list) {
list.immutable$list = true;
list.fixed$length = true;
return list;
};
''');
}
/**
* Documentation wanted -- johnniwinther
*
* Invariant: [member] must be a declaration element.
*/
void emitExtraAccessors(Element member, ClassBuilder builder) {
assert(invariant(member, member.isDeclaration));
if (member.isGetter() || member.isField()) {
Set<Selector> selectors = compiler.codegenWorld.invokedNames[member.name];
if (selectors != null && !selectors.isEmpty) {
emitCallStubForGetter(member, selectors, builder.addProperty);
}
} else if (member.isFunction()) {
if (compiler.codegenWorld.hasInvokedGetter(member, compiler)) {
emitDynamicFunctionGetter(member, builder.addProperty);
}
}
}
void emitNoSuchMethodHandlers(DefineStubFunction defineStub) {
// Do not generate no such method handlers if there is no class.
if (compiler.codegenWorld.instantiatedClasses.isEmpty) return;
String noSuchMethodName = namer.publicInstanceMethodNameByArity(
Compiler.NO_SUCH_METHOD, Compiler.NO_SUCH_METHOD_ARG_COUNT);
Element createInvocationMirrorElement =
compiler.findHelper(const SourceString("createInvocationMirror"));
String createInvocationMirrorName =
namer.getName(createInvocationMirrorElement);
// Keep track of the JavaScript names we've already added so we
// do not introduce duplicates (bad for code size).
Set<String> addedJsNames = new Set<String>();
jsAst.Expression generateMethod(String jsName, Selector selector) {
// Values match JSInvocationMirror in js-helper library.
int type = selector.invocationMirrorKind;
String methodName = selector.invocationMirrorMemberName;
List<jsAst.Parameter> parameters = <jsAst.Parameter>[];
CodeBuffer args = new CodeBuffer();
for (int i = 0; i < selector.argumentCount; i++) {
parameters.add(new jsAst.Parameter('\$$i'));
}
List<jsAst.Expression> argNames =
selector.getOrderedNamedArguments().map((SourceString name) =>
js.string(name.slowToString())).toList();
String internalName = namer.invocationMirrorInternalName(selector);
String createInvocationMirror = namer.getName(
compiler.createInvocationMirrorElement);
assert(backend.isInterceptedName(Compiler.NO_SUCH_METHOD));
jsAst.Expression expression = js['this.$noSuchMethodName'](
[js['this'],
js[namer.CURRENT_ISOLATE][createInvocationMirror]([
js.string(methodName),
js.string(internalName),
type,
new jsAst.ArrayInitializer.from(
parameters.map((param) => js[param.name]).toList()),
new jsAst.ArrayInitializer.from(argNames)])]);
parameters = backend.isInterceptedName(selector.name)
? ([new jsAst.Parameter('\$receiver')]..addAll(parameters))
: parameters;
return js.fun(parameters, js.return_(expression));
}
void addNoSuchMethodHandlers(SourceString ignore, Set<Selector> selectors) {
// Cache the object class and type.
ClassElement objectClass = compiler.objectClass;
DartType objectType = objectClass.computeType(compiler);
for (Selector selector in selectors) {
// Introduce a helper function that determines if the given
// class has a member that matches the current name and
// selector (grabbed from the scope).
bool hasMatchingMember(ClassElement holder) {
Element element = holder.lookupSelector(selector);
return (element != null)
? selector.applies(element, compiler)
: false;
}
// If the selector is typed, we check to see if that type may
// have a user-defined noSuchMethod implementation. If not, we
// skip the selector altogether.
// TODO(kasperl): This shouldn't depend on the internals of
// the type mask. Move more of this code to the type mask.
ClassElement receiverClass = objectClass;
TypeMask mask = selector.mask;
if (mask != null) {
receiverClass = mask.base.element;
}
// If the receiver class is guaranteed to have a member that
// matches what we're looking for, there's no need to
// introduce a noSuchMethod handler. It will never be called.
//
// As an example, consider this class hierarchy:
//
// A <-- noSuchMethod
// / \
// C B <-- foo
//
// If we know we're calling foo on an object of type B we
// don't have to worry about the noSuchMethod method in A
// because objects of type B implement foo. On the other hand,
// if we end up calling foo on something of type C we have to
// add a handler for it.
if (hasMatchingMember(receiverClass)) continue;
// If the holders of all user-defined noSuchMethod
// implementations that might be applicable to the receiver
// type have a matching member for the current name and
// selector, we avoid introducing a noSuchMethod handler.
//
// As an example, consider this class hierarchy:
//
// A <-- foo
// / \
// noSuchMethod --> B C <-- bar
// | |
// C D <-- noSuchMethod
//
// When calling foo on an object of type A, we know that the
// implementations of noSuchMethod are in the classes B and D
// that also (indirectly) implement foo, so we do not need a
// handler for it.
//
// If we're calling bar on an object of type D, we don't need
// the handler either because all objects of type D implement
// bar through inheritance.
//
// If we're calling bar on an object of type A we do need the
// handler because we may have to call B.noSuchMethod since B
// does not implement bar.
Iterable<ClassElement> holders =
compiler.world.locateNoSuchMethodHolders(selector);
if (holders.every(hasMatchingMember)) continue;
String jsName = namer.invocationMirrorInternalName(selector);
if (!addedJsNames.contains(jsName)) {
jsAst.Expression method = generateMethod(jsName, selector);
defineStub(jsName, method);
addedJsNames.add(jsName);
}
}
}
compiler.codegenWorld.invokedNames.forEach(addNoSuchMethodHandlers);
compiler.codegenWorld.invokedGetters.forEach(addNoSuchMethodHandlers);
compiler.codegenWorld.invokedSetters.forEach(addNoSuchMethodHandlers);
}
String buildIsolateSetup(CodeBuffer buffer,
Element appMain,
Element isolateMain) {
String mainAccess = "${namer.isolateAccess(appMain)}";
String currentIsolate = "${namer.CURRENT_ISOLATE}";
// Since we pass the closurized version of the main method to
// the isolate method, we must make sure that it exists.
if (!compiler.codegenWorld.staticFunctionsNeedingGetter.contains(appMain)) {
Selector selector = new Selector.callClosure(0);
String invocationName = namer.invocationName(selector);
buffer.add("$mainAccess.$invocationName = $mainAccess$N");
}
return "${namer.isolateAccess(isolateMain)}($mainAccess)";
}
emitMain(CodeBuffer buffer) {
if (compiler.isMockCompilation) return;
Element main = compiler.mainApp.find(Compiler.MAIN);
String mainCall = null;
if (compiler.hasIsolateSupport()) {
Element isolateMain =
compiler.isolateHelperLibrary.find(Compiler.START_ROOT_ISOLATE);
mainCall = buildIsolateSetup(buffer, main, isolateMain);
} else {
mainCall = '${namer.isolateAccess(main)}()';
}
addComment('BEGIN invoke [main].', buffer);
buffer.add("""
if (typeof document !== "undefined" && document.readyState !== "complete") {
document.addEventListener("readystatechange", function () {
if (document.readyState == "complete") {
if (typeof dartMainRunner === "function") {
dartMainRunner(function() { ${mainCall}; });
} else {
${mainCall};
}
}
}, false);
} else {
if (typeof dartMainRunner === "function") {
dartMainRunner(function() { ${mainCall}; });
} else {
${mainCall};
}
}
""");
addComment('END invoke [main].', buffer);
}
void emitGetInterceptorMethod(CodeBuffer buffer,
String key,
Collection<ClassElement> classes) {
jsAst.Statement buildReturnInterceptor(ClassElement cls) {
return js.return_(js[namer.isolateAccess(cls)]['prototype']);
}
jsAst.VariableUse receiver = js['receiver'];
/**
* Build a JavaScrit AST node for doing a type check on
* [cls]. [cls] must be an interceptor class.
*/
jsAst.Statement buildInterceptorCheck(ClassElement cls) {
jsAst.Expression condition;
assert(backend.isInterceptorClass(cls));
if (cls == backend.jsBoolClass) {
condition = receiver.typeof.equals(js.string('boolean'));
} else if (cls == backend.jsIntClass ||
cls == backend.jsDoubleClass ||
cls == backend.jsNumberClass) {
throw 'internal error';
} else if (cls == backend.jsArrayClass) {
condition = receiver['constructor'].equals('Array');
} else if (cls == backend.jsStringClass) {
condition = receiver.typeof.equals(js.string('string'));
} else if (cls == backend.jsNullClass) {
condition = receiver.equals(new jsAst.LiteralNull());
} else if (cls == backend.jsFunctionClass) {
condition = receiver.typeof.equals(js.string('function'));
} else {
throw 'internal error';
}
return js.if_(condition, buildReturnInterceptor(cls));
}
bool hasArray = false;
bool hasBool = false;
bool hasDouble = false;
bool hasFunction = false;
bool hasInt = false;
bool hasNull = false;
bool hasNumber = false;
bool hasString = false;
for (ClassElement cls in classes) {
if (cls == backend.jsArrayClass) hasArray = true;
else if (cls == backend.jsBoolClass) hasBool = true;
else if (cls == backend.jsDoubleClass) hasDouble = true;
else if (cls == backend.jsFunctionClass) hasFunction = true;
else if (cls == backend.jsIntClass) hasInt = true;
else if (cls == backend.jsNullClass) hasNull = true;
else if (cls == backend.jsNumberClass) hasNumber = true;
else if (cls == backend.jsStringClass) hasString = true;
else {
assert(cls == compiler.objectClass);
}
}
if (hasDouble) {
hasNumber = true;
}
if (hasInt) hasNumber = true;
jsAst.Block block = new jsAst.Block.empty();
if (hasNumber) {
jsAst.Statement whenNumber;
/// Note: there are two number classes in play: Dart's [num],
/// and JavaScript's Number (typeof receiver == 'number'). This
/// is the fallback used when we have determined that receiver
/// is a JavaScript Number.
jsAst.Return returnNumberClass = buildReturnInterceptor(
hasDouble ? backend.jsDoubleClass : backend.jsNumberClass);
if (hasInt) {
jsAst.Expression isInt = js['Math']['floor'](receiver).equals(receiver);
whenNumber = js.block([
js.if_(isInt, buildReturnInterceptor(backend.jsIntClass)),
returnNumberClass]);
} else {
whenNumber = returnNumberClass;
}
block.statements.add(
js.if_(receiver.typeof.equals(js.string('number')),
whenNumber));
}
if (hasString) {
block.statements.add(buildInterceptorCheck(backend.jsStringClass));
}
if (hasNull) {
block.statements.add(buildInterceptorCheck(backend.jsNullClass));
} else {
// Returning "undefined" here will provoke a JavaScript
// TypeError which is later identified as a null-error by
// [unwrapException] in js_helper.dart.
block.statements.add(js.if_(receiver.equals(new jsAst.LiteralNull()),
js.return_(js.undefined())));
}
if (hasFunction) {
block.statements.add(buildInterceptorCheck(backend.jsFunctionClass));
}
if (hasBool) {
block.statements.add(buildInterceptorCheck(backend.jsBoolClass));
}
// TODO(ahe): It might be faster to check for Array before
// function and bool.
if (hasArray) {
block.statements.add(buildInterceptorCheck(backend.jsArrayClass));
}
block.statements.add(js.return_(receiver));
buffer.add(jsAst.prettyPrint(
js[isolateProperties][key].assign(js.fun(['receiver'], block)),
compiler));
buffer.add(N);
}
/**
* Emit all versions of the [:getInterceptor:] method.
*/
void emitGetInterceptorMethods(CodeBuffer buffer) {
var specializedGetInterceptors = backend.specializedGetInterceptors;
for (String name in specializedGetInterceptors.keys.toList()..sort()) {
Collection<ClassElement> classes = specializedGetInterceptors[name];
emitGetInterceptorMethod(buffer, name, classes);
}
}
/**
* Compute all the classes that must be emitted.
*/
void computeNeededClasses() {
instantiatedClasses =
compiler.codegenWorld.instantiatedClasses.where(computeClassFilter())
.toSet();
// The set of classes that must be emitted are based on instantiated
// classes.
neededClasses.addAll(instantiatedClasses);
// Then add all superclasses of these classes.
for (ClassElement element in neededClasses.toList() /* copy */) {
for (ClassElement superclass = element.superclass;
superclass != null;
superclass = superclass.superclass) {
if (neededClasses.contains(superclass)) break;
neededClasses.add(superclass);
}
}
// Finally, sort the classes.
List<ClassElement> sortedClasses = neededClasses.toList();
sortedClasses.sort((ClassElement class1, ClassElement class2) {
// We sort by the ids of the classes. There is no guarantee that these
// ids are meaningful (or even deterministic), but in the current
// implementation they are increasing within a source file.
return class1.id - class2.id;
});
// If we need noSuchMethod support, we run through all needed
// classes to figure out if we need the support on any native
// class. If so, we let the native emitter deal with it.
if (compiler.enabledNoSuchMethod) {
SourceString noSuchMethodName = Compiler.NO_SUCH_METHOD;
Selector noSuchMethodSelector = new Selector.noSuchMethod();
for (ClassElement element in sortedClasses) {
if (!element.isNative()) continue;
Element member = element.lookupLocalMember(noSuchMethodName);
if (member == null) continue;
if (noSuchMethodSelector.applies(member, compiler)) {
nativeEmitter.handleNoSuchMethod = true;
break;
}
}
}
for (ClassElement element in sortedClasses) {
if (element.isNative()) {
// For now, native classes cannot be deferred.
nativeClasses.add(element);
} else if (isDeferred(element)) {
deferredClasses.add(element);
} else {
regularClasses.add(element);
}
}
}
int _compareSelectors(Selector selector1, Selector selector2) {
int comparison = _compareSelectorNames(selector1, selector2);
if (comparison != 0) return comparison;
Set<ClassElement> classes1 = backend.getInterceptedClassesOn(selector1);
Set<ClassElement> classes2 = backend.getInterceptedClassesOn(selector2);
if (classes1.length != classes2.length) {
return classes1.length - classes2.length;
}
String getInterceptor1 =
namer.getInterceptorName(backend.getInterceptorMethod, classes1);
String getInterceptor2 =
namer.getInterceptorName(backend.getInterceptorMethod, classes2);
return Comparable.compare(getInterceptor1, getInterceptor2);
}
// Optimize performance critical one shot interceptors.
jsAst.Statement tryOptimizeOneShotInterceptor(Selector selector,
Set<ClassElement> classes) {
jsAst.Expression isNumber(String variable) {
return js[variable].typeof.equals(js.string('number'));
}
jsAst.Expression isNotObject(String variable) {
return js[variable].typeof.equals(js.string('object')).not;
}
jsAst.Expression isInt(String variable) {
jsAst.Expression receiver = js[variable];
return isNumber(variable).binary('&&',
js['Math']['floor'](receiver).equals(receiver));
}
jsAst.Expression tripleShiftZero(jsAst.Expression receiver) {
return receiver.binary('>>>', js.toExpression(0));
}
if (selector.isOperator()) {
String name = selector.name.stringValue;
if (name == '==') {
// Unfolds to:
// [: if (receiver == null) return a0 == null;
// if (typeof receiver != 'object') {
// return a0 != null && receiver === a0;
// }
// :].
List<jsAst.Statement> body = <jsAst.Statement>[];
body.add(js.if_(js['receiver'].equals(new jsAst.LiteralNull()),
js.return_(js['a0'].equals(new jsAst.LiteralNull()))));
body.add(js.if_(
isNotObject('receiver'),
js.return_(js['a0'].equals(new jsAst.LiteralNull()).not.binary(
'&&', js['receiver'].strictEquals(js['a0'])))));
return new jsAst.Block(body);
}
if (!classes.contains(backend.jsIntClass)
&& !classes.contains(backend.jsNumberClass)
&& !classes.contains(backend.jsDoubleClass)) {
return null;
}
if (selector.argumentCount == 1) {
// The following operators do not map to a JavaScript
// operator.
if (name != '~/' && name != '<<' && name != '%' && name != '>>') {
jsAst.Expression result = js['receiver'].binary(name, js['a0']);
if (name == '&' || name == '|' || name == '^') {
result = tripleShiftZero(result);
}
// Unfolds to:
// [: if (typeof receiver == "number" && typeof a0 == "number")
// return receiver op a0;
// :].
return js.if_(
isNumber('receiver').binary('&&', isNumber('a0')),
js.return_(result));
}
} else if (name == 'unary-') {
// operator~ does not map to a JavaScript operator.
// Unfolds to:
// [: if (typeof receiver == "number") return -receiver:].
return js.if_(
isNumber('receiver'),
js.return_(new jsAst.Prefix('-', js['receiver'])));
} else {
assert(name == '~');
return js.if_(
isInt('receiver'),
js.return_(
tripleShiftZero(new jsAst.Prefix(name, js['receiver']))));
}
} else if (selector.isIndex() || selector.isIndexSet()) {
// For an index operation, this code generates:
//
// [: if (receiver.constructor == Array || typeof receiver == "string") {
// if (a0 >>> 0 === a0 && a0 < receiver.length) {
// return receiver[a0];
// }
// }
// :]
//
// For an index set operation, this code generates:
//
// [: if (receiver.constructor == Array && !receiver.immutable$list) {
// if (a0 >>> 0 === a0 && a0 < receiver.length) {
// return receiver[a0] = a1;
// }
// }
// :]
bool containsArray = classes.contains(backend.jsArrayClass);
bool containsString = classes.contains(backend.jsStringClass);
// The index set operator requires a check on its set value in
// checked mode, so we don't optimize the interceptor if the
// compiler has type assertions enabled.
if (selector.isIndexSet()
&& (compiler.enableTypeAssertions || !containsArray)) {
return null;
}
if (!containsArray && !containsString) {
return null;
}
jsAst.Expression receiver = js['receiver'];
jsAst.Expression arg0 = js['a0'];
jsAst.Expression isIntAndAboveZero =
arg0.binary('>>>', js.toExpression(0)).strictEquals(arg0);
jsAst.Expression belowLength = arg0.binary('<', receiver['length']);
jsAst.Expression arrayCheck = receiver['constructor'].equals('Array');
if (selector.isIndex()) {
jsAst.Expression stringCheck =
receiver.typeof.equals(js.string('string'));
jsAst.Expression typeCheck;
if (containsArray) {
if (containsString) {
typeCheck = arrayCheck.binary('||', stringCheck);
} else {
typeCheck = arrayCheck;
}
} else {
assert(containsString);
typeCheck = stringCheck;
}
return js.if_(typeCheck,
js.if_(isIntAndAboveZero.binary('&&', belowLength),
js.return_(receiver[arg0])));
} else {
jsAst.Expression isImmutableArray = arrayCheck.binary(
'&&', receiver[r'immutable$list'].not);
return js.if_(isImmutableArray.binary(
'&&', isIntAndAboveZero.binary('&&', belowLength)),
js.return_(receiver[arg0].assign(js['a1'])));
}
}
return null;
}
void emitOneShotInterceptors(CodeBuffer buffer) {
List<String> names = backend.oneShotInterceptors.keys.toList();
names.sort();
for (String name in names) {
Selector selector = backend.oneShotInterceptors[name];
Set<ClassElement> classes =
backend.getInterceptedClassesOn(selector.name);
String getInterceptorName =
namer.getInterceptorName(backend.getInterceptorMethod, classes);
List<jsAst.Parameter> parameters = <jsAst.Parameter>[];
List<jsAst.Expression> arguments = <jsAst.Expression>[];
parameters.add(new jsAst.Parameter('receiver'));
arguments.add(js['receiver']);
if (selector.isSetter()) {
parameters.add(new jsAst.Parameter('value'));
arguments.add(js['value']);
} else {
for (int i = 0; i < selector.argumentCount; i++) {
String argName = 'a$i';
parameters.add(new jsAst.Parameter(argName));
arguments.add(js[argName]);
}
}
List<jsAst.Statement> body = <jsAst.Statement>[];
jsAst.Statement optimizedPath =
tryOptimizeOneShotInterceptor(selector, classes);
if (optimizedPath != null) {
body.add(optimizedPath);
}
String invocationName = backend.namer.invocationName(selector);
body.add(js.return_(
js[isolateProperties][getInterceptorName]('receiver')[invocationName](
arguments)));
jsAst.Fun function = js.fun(parameters, body);
jsAst.PropertyAccess property =
js[isolateProperties][name];
buffer.add(jsAst.prettyPrint(property.assign(function), compiler));
buffer.add(N);
}
}
/**
* If [:invokeOn:] has been compiled, emit all the possible selector names
* that are intercepted into the [:interceptedNames:] top-level
* variable. The implementation of [:invokeOn:] will use it to
* determine whether it should call the method with an extra
* parameter.
*/
void emitInterceptedNames(CodeBuffer buffer) {
if (!compiler.enabledInvokeOn) return;
String name = backend.namer.getName(backend.interceptedNames);
jsAst.PropertyAccess property = js[isolateProperties][name];
int index = 0;
List<jsAst.ArrayElement> elements = backend.usedInterceptors.map(
(Selector selector) {
jsAst.Literal str = js.string(namer.invocationName(selector));
return new jsAst.ArrayElement(index++, str);
}).toList();
jsAst.ArrayInitializer array = new jsAst.ArrayInitializer(
backend.usedInterceptors.length,
elements);
buffer.add(jsAst.prettyPrint(property.assign(array), compiler));
buffer.add(N);
}
void emitInitFunction(CodeBuffer buffer) {
jsAst.Fun fun = js.fun([], [
js['$isolateProperties = {}'],
]
..addAll(buildDefineClassAndFinishClassFunctionsIfNecessary())
..addAll(buildLazyInitializerFunctionIfNecessary())
..addAll(buildFinishIsolateConstructor())
);
jsAst.FunctionDeclaration decl = new jsAst.FunctionDeclaration(
new jsAst.VariableDeclaration('init'), fun);
buffer.add(jsAst.prettyPrint(decl, compiler).getText());
}
String assembleProgram() {
measure(() {
computeNeededClasses();
// Compute the required type checks to know which classes need a
// 'is$' method.
computeRequiredTypeChecks();
mainBuffer.add(GENERATED_BY);
addComment(HOOKS_API_USAGE, mainBuffer);
mainBuffer.add('function ${namer.isolateName}()$_{}\n');
mainBuffer.add('init()$N$n');
// Shorten the code by using [namer.CURRENT_ISOLATE] as temporary.
isolateProperties = namer.CURRENT_ISOLATE;
mainBuffer.add(
'var $isolateProperties$_=$_$isolatePropertiesName$N');
if (!regularClasses.isEmpty ||
!deferredClasses.isEmpty ||
!nativeClasses.isEmpty) {
// Shorten the code by using "$$" as temporary.
classesCollector = r"$$";
mainBuffer.add('var $classesCollector$_=$_{}$N$n');
}
// Emit native classes on [nativeBuffer]. As a side-effect,
// this will produce "bound closures" in [boundClosures]. The
// bound closures are JS AST nodes that add properties to $$
// [classesCollector]. The bound closures are not emitted until
// we have emitted all other classes (native or not).
final CodeBuffer nativeBuffer = new CodeBuffer();
if (!nativeClasses.isEmpty) {
addComment('Native classes', nativeBuffer);
for (ClassElement element in nativeClasses) {
nativeEmitter.generateNativeClass(element);
}
nativeEmitter.assembleCode(nativeBuffer);
}
// Might also create boundClosures.
if (!regularClasses.isEmpty) {
addComment('Classes', mainBuffer);
for (ClassElement element in regularClasses) {
generateClass(element, mainBuffer);
}
}
// Might also create boundClosures.
if (!deferredClasses.isEmpty) {
emitDeferredPreambleWhenEmpty(deferredBuffer);
deferredBuffer.add('\$\$$_=$_{}$N');
for (ClassElement element in deferredClasses) {
generateClass(element, deferredBuffer);
}
deferredBuffer.add('$finishClassesName(\$\$,'
'$_${namer.CURRENT_ISOLATE},'
'$_$isolatePropertiesName)$N');
// Reset the map.
deferredBuffer.add("\$\$$_=${_}null$N$n");
}
emitClosureClassIfNeeded(mainBuffer);
// Now that we have emitted all classes, we know all the bound
// closures that will be needed.
for (jsAst.Node node in boundClosures) {
// TODO(ahe): Some of these can be deferred.
mainBuffer.add(jsAst.prettyPrint(node, compiler));
mainBuffer.add("$N$n");
}
emitFinishClassesInvocationIfNecessary(mainBuffer);
// After this assignment we will produce invalid JavaScript code if we use
// the classesCollector variable.
classesCollector = 'classesCollector should not be used from now on';
emitStaticFunctions(mainBuffer);
emitStaticFunctionGetters(mainBuffer);
emitRuntimeTypeSupport(mainBuffer);
emitCompileTimeConstants(mainBuffer);
// Static field initializations require the classes and compile-time
// constants to be set up.
emitStaticNonFinalFieldInitializations(mainBuffer);
emitOneShotInterceptors(mainBuffer);
emitInterceptedNames(mainBuffer);
emitGetInterceptorMethods(mainBuffer);
emitLazilyInitializedStaticFields(mainBuffer);
isolateProperties = isolatePropertiesName;
// The following code should not use the short-hand for the
// initialStatics.
mainBuffer.add('var ${namer.CURRENT_ISOLATE}$_=${_}null$N');
emitFinishIsolateConstructorInvocation(mainBuffer);
mainBuffer.add('var ${namer.CURRENT_ISOLATE}$_='
'${_}new ${namer.isolateName}()$N');
mainBuffer.add(nativeBuffer);
emitMain(mainBuffer);
emitInitFunction(mainBuffer);
compiler.assembledCode = mainBuffer.getText();
outputSourceMap(mainBuffer, compiler.assembledCode, '');
emitDeferredCode(deferredBuffer);
});
return compiler.assembledCode;
}
CodeBuffer bufferForElement(Element element, CodeBuffer eagerBuffer) {
if (!isDeferred(element)) return eagerBuffer;
emitDeferredPreambleWhenEmpty(deferredBuffer);
return deferredBuffer;
}
void emitDeferredCode(CodeBuffer buffer) {
if (buffer.isEmpty) return;
buffer.add(n);
buffer.add('${namer.CURRENT_ISOLATE}$_=${_}old${namer.CURRENT_ISOLATE}$N');
String code = buffer.getText();
compiler.outputProvider('part', 'js')
..add(code)
..close();
outputSourceMap(buffer, compiler.assembledCode, 'part');
}
void emitDeferredPreambleWhenEmpty(CodeBuffer buffer) {
if (!buffer.isEmpty) return;
buffer.add(GENERATED_BY);
buffer.add('var old${namer.CURRENT_ISOLATE}$_='
'$_${namer.CURRENT_ISOLATE}$N');
// TODO(ahe): This defines a lot of properties on the
// Isolate.prototype object. We know this will turn it into a
// slow object in V8, so instead we should do something similar to
// Isolate.$finishIsolateConstructor.
buffer.add('${namer.CURRENT_ISOLATE}$_='
'$_${namer.isolateName}.prototype$N$n');
}
String buildSourceMap(CodeBuffer buffer, SourceFile compiledFile) {
SourceMapBuilder sourceMapBuilder = new SourceMapBuilder();
buffer.forEachSourceLocation(sourceMapBuilder.addMapping);
return sourceMapBuilder.build(compiledFile);
}
void outputSourceMap(CodeBuffer buffer, String code, String name) {
if (!generateSourceMap) return;
SourceFile compiledFile = new SourceFile(null, compiler.assembledCode);
String sourceMap = buildSourceMap(mainBuffer, compiledFile);
compiler.outputProvider(name, 'js.map')
..add(sourceMap)
..close();
}
bool isDeferred(Element element) {
return compiler.deferredLoadTask.isDeferred(element);
}
// TODO(ahe): Remove this when deferred loading is fully implemented.
void warnNotImplemented(Element element, String message) {
compiler.reportMessage(compiler.spanFromSpannable(element),
MessageKind.GENERIC.error({'text': message}),
api.Diagnostic.WARNING);
}
}
const String GENERATED_BY = """
// Generated by dart2js, the Dart to JavaScript compiler.
""";
const String HOOKS_API_USAGE = """
// The code supports the following hooks:
// dartPrint(message) - if this function is defined it is called
// instead of the Dart [print] method.
// dartMainRunner(main) - if this function is defined, the Dart [main]
// method will not be invoked directly.
// Instead, a closure that will invoke [main] is
// passed to [dartMainRunner].
""";