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dart / sdk.git / 9b486e5a2731148ab0444ed726495cb83dc15c2e / . / 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, js.Expression value);
/**
* A data structure for collecting fragments of a class definition.
*/
class ClassBuilder {
final List<js.Property> properties = <js.Property>[];
// Has the same signature as [DefineStubFunction].
void addProperty(String name, js.Expression value) {
properties.add(new js.Property(js.string(name), value));
}
js.Expression toObjectInitializer() => new js.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 boundClosureBuffer;
CodeBuffer mainBuffer;
/** Shorter access to [isolatePropertiesName]. Both here in the code, as
well as in the generated code. */
String isolateProperties;
String classesCollector;
Set<ClassElement> neededClasses;
// TODO(ngeoffray): remove this field.
Set<ClassElement> instantiatedClasses;
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;
CodeEmitterTask(Compiler compiler, Namer namer, this.generateSourceMap)
: boundClosureBuffer = new CodeBuffer(),
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 computeRequiredTypeChecks() {
assert(checkedClasses == null);
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);
}
});
}
js.Expression constantReference(Constant value) {
return constantEmitter.reference(value);
}
js.Expression constantInitializerExpression(Constant value) {
return constantEmitter.initializationExpression(value);
}
String get name => 'CodeEmitter';
String get defineClassName
=> '${namer.isolateName}.\$defineClass';
String get currentGenerateAccessorName
=> '${namer.CURRENT_ISOLATE}.\$generateAccessor';
String get generateAccessorHolder
=> '$isolatePropertiesName.\$generateAccessor';
String get finishClassesName
=> '${namer.isolateName}.\$finishClasses';
String get finishIsolateConstructorName
=> '${namer.isolateName}.\$finishIsolateConstructor';
String get pendingClassesName
=> '${namer.isolateName}.\$pendingClasses';
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';
String get generateAccessorFunction {
return """
function generateAccessor(field, prototype) {
var len = field.length;
var lastCharCode = field.charCodeAt(len - 1);
var needsAccessor = (lastCharCode & $SUFFIX_MASK) >= $FIRST_SUFFIX_CODE;
if (needsAccessor) {
var needsGetter = ${needsGetterCode('lastCharCode')};
var needsSetter = ${needsSetterCode('lastCharCode')};
var renaming = ${isRenaming('lastCharCode')};
var accessorName = field = field.substring(0, len - 1);
if (renaming) {
var divider = field.indexOf(":");
accessorName = field.substring(0, divider);
field = field.substring(divider + 1);
}
if (needsGetter) {
var getterString = "return this." + field + ";";
prototype["${namer.getterPrefix}" + accessorName] =
new Function(getterString);
}
if (needsSetter) {
var setterString = "this." + field + " = v;";
prototype["${namer.setterPrefix}" + accessorName] =
new Function("v", setterString);
}
}
return field;
}""";
}
String 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;
// },
// });
return """
function(cls, fields, prototype) {
var constructor;
if (typeof fields == 'function') {
constructor = fields;
} else {
var str = "function " + cls + "(";
var body = "";
for (var i = 0; i < fields.length; i++) {
if (i != 0) str += ", ";
var field = fields[i];
field = generateAccessor(field, prototype);
str += field;
body += "this." + field + " = " + field + ";\\n";
}
str += ") {" + body + "}\\n";
str += "return " + cls + ";";
constructor = new Function(str)();
}
constructor.prototype = prototype;
constructor.builtin\$cls = cls;
return constructor;
}""";
}
/** Needs defineClass to be defined. */
String get protoSupportCheck {
// 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.
return '''
var $supportsProtoName = false;
var tmp = $defineClassName('c', ['f?'], {}).prototype;
if (tmp.__proto__) {
tmp.__proto__ = {};
if (typeof tmp.get\$f !== 'undefined') $supportsProtoName = true;
}
''';
}
String get finishClassesFunction {
// 'defineClass' does not require the classes to be constructed in order.
// Classes are initially just stored in the 'pendingClasses' field.
// 'finishClasses' takes all pending classes 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.
return '''
function(collectedClasses) {
var hasOwnProperty = Object.prototype.hasOwnProperty;
for (var cls in collectedClasses) {
if (hasOwnProperty.call(collectedClasses, cls)) {
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;
if (typeof fields == 'string') {
var s = fields.split(';'); supr = s[0];
fields = s[1] == '' ? [] : s[1].split(',');
} else {
supr = desc['super'];
}
$isolatePropertiesName[cls] = $defineClassName(cls, fields, desc);
if (supr) $pendingClassesName[cls] = supr;
}
}
var pendingClasses = $pendingClassesName;
'''/* FinishClasses can be called multiple times. This means that we need to
clear the pendingClasses property. */'''
$pendingClassesName = {};
var finishedClasses = {};
function finishClass(cls) {
'''/* Opera does not support 'getOwnPropertyNames'. Therefore we use
hasOwnProperty instead. */'''
var hasOwnProperty = Object.prototype.hasOwnProperty;
if (hasOwnProperty.call(finishedClasses, cls)) return;
finishedClasses[cls] = true;
var superclass = pendingClasses[cls];
'''/* The superclass is only false (empty string) for Dart's Object class. */'''
if (!superclass) return;
finishClass(superclass);
var constructor = $isolatePropertiesName[cls];
var superConstructor = $isolatePropertiesName[superclass];
var prototype = constructor.prototype;
if ($supportsProtoName) {
prototype.__proto__ = superConstructor.prototype;
prototype.constructor = constructor;
} else {
function tmp() {};
tmp.prototype = superConstructor.prototype;
var newPrototype = new tmp();
constructor.prototype = newPrototype;
newPrototype.constructor = constructor;
for (var member in prototype) {
if (!member) continue; '''/* Short version of: if (member == '') */'''
if (hasOwnProperty.call(prototype, member)) {
newPrototype[member] = prototype[member];
}
}
}
}
for (var cls in pendingClasses) finishClass(cls);
}''';
}
String 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.$isolateProperties;
// this.x = isolateProperties.x;
// this.A = isolateProperties.A;
// }";
// which is then dynamically evaluated:
// var newIsolate = new Function(str);
//
// We also copy over old values like the prototype, and the
// isolateProperties themselves.
return """function(oldIsolate) {
var isolateProperties = oldIsolate.${namer.isolatePropertiesName};
var isolatePrototype = oldIsolate.prototype;
var str = "{\\n";
str += "var properties = $isolate.${namer.isolatePropertiesName};\\n";
for (var staticName in isolateProperties) {
if (Object.prototype.hasOwnProperty.call(isolateProperties, staticName)) {
str += "this." + staticName + "= properties." + staticName + ";\\n";
}
}
str += "}\\n";
var newIsolate = new Function(str);
newIsolate.prototype = isolatePrototype;
isolatePrototype.constructor = newIsolate;
newIsolate.${namer.isolatePropertiesName} = isolateProperties;
return newIsolate;
}""";
}
String get lazyInitializerFunction {
String isolate = namer.CURRENT_ISOLATE;
return """
function(prototype, staticName, fieldName, getterName, lazyValue) {
var getter = new Function("{ return $isolate." + fieldName + ";}");
$lazyInitializerLogic
}""";
}
String get lazyInitializerLogic {
String isolate = namer.CURRENT_ISOLATE;
JavaScriptBackend backend = compiler.backend;
String cyclicThrow = namer.isolateAccess(backend.cyclicThrowHelper);
return """
var sentinelUndefined = {};
var sentinelInProgress = {};
prototype[fieldName] = sentinelUndefined;
prototype[getterName] = function() {
var result = $isolate[fieldName];
try {
if (result === sentinelUndefined) {
$isolate[fieldName] = sentinelInProgress;
try {
result = $isolate[fieldName] = lazyValue();
} finally {
""" // Use try-finally, not try-catch/throw as it destroys the stack trace.
"""
if (result === sentinelUndefined) {
if ($isolate[fieldName] === sentinelInProgress) {
$isolate[fieldName] = null;
}
}
}
} else if (result === sentinelInProgress) {
$cyclicThrow(staticName);
}
return result;
} finally {
$isolate[getterName] = getter;
}
};""";
}
void addDefineClassAndFinishClassFunctionsIfNecessary(CodeBuffer buffer) {
if (needsDefineClass) {
// Declare function called generateAccessor. This is used in
// defineClassFunction (it's a local declaration in init()).
buffer.add("$generateAccessorFunction$N");
buffer.add("$generateAccessorHolder = generateAccessor$N");
buffer.add("$defineClassName = $defineClassFunction$N");
buffer.add(protoSupportCheck);
buffer.add("$pendingClassesName = {}$N");
buffer.add("$finishClassesName = $finishClassesFunction$N");
}
}
void addLazyInitializerFunctionIfNecessary(CodeBuffer buffer) {
if (needsLazyInitializer) {
buffer.add("$lazyInitializerName = $lazyInitializerFunction$N");
}
}
void emitFinishIsolateConstructor(CodeBuffer buffer) {
String name = finishIsolateConstructorName;
String value = finishIsolateConstructorFunction;
buffer.add("$name = $value$N");
}
void emitFinishIsolateConstructorInvocation(CodeBuffer buffer) {
String isolate = namer.isolateName;
buffer.add("$isolate = $finishIsolateConstructorName($isolate)$N");
}
/**
* Generate stubs to handle invocation of methods with optional
* arguments.
*
* A method like [: foo([x]) :] may be invoked by the following
* calls: [: foo(), foo(1), foo(x: 1) :]. See the sources of this
* function for detailed examples.
*/
void addParameterStub(FunctionElement member,
Selector selector,
DefineStubFunction defineStub,
Set<String> alreadyGenerated) {
FunctionSignature parameters = member.computeSignature(compiler);
int positionalArgumentCount = selector.positionalArgumentCount;
if (positionalArgumentCount == parameters.parameterCount) {
assert(selector.namedArgumentCount == 0);
return;
}
if (parameters.optionalParametersAreNamed
&& selector.namedArgumentCount == parameters.optionalParameterCount) {
// If the selector has the same number of named arguments as
// the element, we don't need to add a stub. The call site will
// hit the method directly.
return;
}
ConstantHandler handler = compiler.constantHandler;
List<SourceString> names = selector.getOrderedNamedArguments();
String invocationName = namer.invocationName(selector);
if (alreadyGenerated.contains(invocationName)) return;
alreadyGenerated.add(invocationName);
JavaScriptBackend backend = compiler.backend;
bool isInterceptorClass =
backend.isInterceptorClass(member.getEnclosingClass());
// If the method is in an interceptor class, we need to also pass
// the actual receiver.
int extraArgumentCount = isInterceptorClass ? 1 : 0;
// Use '$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<js.Parameter> parametersBuffer =
new List<js.Parameter>.fixedLength(
selector.argumentCount + extraArgumentCount);
// The arguments that will be passed to the real method.
List<js.Expression> argumentsBuffer =
new List<js.Expression>.fixedLength(
parameters.parameterCount + extraArgumentCount);
int count = 0;
if (isInterceptorClass) {
count++;
parametersBuffer[0] = new js.Parameter(receiverArgumentName);
argumentsBuffer[0] = new js.VariableUse(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 js.Parameter(jsName);
argumentsBuffer[count] = new js.VariableUse(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] = new js.VariableUse(jsName);
parametersBuffer[optionalParameterStart + index] =
new js.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<js.Statement> body;
if (member.hasFixedBackendName()) {
body = nativeEmitter.generateParameterStubStatements(
member, invocationName, parametersBuffer, argumentsBuffer,
indexOfLastOptionalArgumentInParameters);
} else {
body = <js.Statement>[
new js.Return(
new js.VariableUse('this')
.dot(namer.getName(member))
.callWith(argumentsBuffer))];
}
js.Fun function = new js.Fun(parametersBuffer, new js.Block(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;
JavaScriptBackend backend = compiler.backend;
js.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));
JavaScriptBackend backend = compiler.backend;
if (classElement == backend.objectInterceptorClass) {
emitInterceptorMethods(builder);
// The ObjectInterceptor does not have any instance methods.
return;
}
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) {
js.Expression code;
if (compiler.objectClass == other) return;
if (nativeEmitter.requiresNativeIsCheck(other)) {
code = js.fun([], js.block1(js.return_(new js.LiteralBool(true))));
} else {
code = new js.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.
js.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 js.LiteralExpression(substitution);
} else if (emitNull || needsNativeCheck) {
expression = new js.LiteralNull();
}
}
if (expression != null) {
if (needsNativeCheck) {
expression =
new js.Fun([], new js.Block([new 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)) {
// The operator== method in [:Object:] does not take the same
// number of arguments as an intercepted method, therefore we
// explicitely add one to all interceptor classes. Note that we
// would not have do do that if all intercepted methods had
// a calling convention where the receiver is the first
// parameter.
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.block1(js.return_(kind(js.use('receiver'), js.use('a'))))));
}
}
void emitRuntimeClassesAndTests(CodeBuffer buffer) {
JavaScriptBackend backend = compiler.backend;
RuntimeTypeInformation rti = backend.rti;
TypeChecks typeChecks = rti.getRequiredChecks();
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 && compiler.enableTypeAssertions
&& canGenerateCheckedSetter(member)) {
needsCheckedSetter = true;
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) {
String getterName = namer.getterNameFromAccessorName(accessorName);
builder.addProperty(getterName,
js.fun([], js.block1(js.return_(js.use('this').dot(fieldName)))));
}
void generateSetter(Element member, String fieldName, String accessorName,
ClassBuilder builder) {
String setterName = namer.setterNameFromAccessorName(accessorName);
builder.addProperty(setterName,
js.fun(['v'],
js.block1(
new js.ExpressionStatement(
js.assign(js.use('this').dot(fieldName), js.use('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;
SourceString helper = compiler.backend.getCheckedModeHelper(type);
FunctionElement helperElement = compiler.findHelper(helper);
String helperName = namer.isolateAccess(helperElement);
List<js.Expression> arguments = <js.Expression>[js.use('v')];
if (helperElement.computeSignature(compiler).parameterCount != 1) {
arguments.add(js.string(namer.operatorIs(type.element)));
}
String setterName = namer.setterNameFromAccessorName(accessorName);
builder.addProperty(setterName,
js.fun(['v'],
js.block1(
new js.ExpressionStatement(
js.assign(
js.use('this').dot(fieldName),
js.call(js.use(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.add('$superClass;');
}
visitClassFields(classElement, (Element member,
String name,
String accessorName,
bool needsGetter,
bool needsSetter,
bool needsCheckedSetter) {
// Ignore needsCheckedSetter - that is handled below.
bool needsAccessor = (needsGetter || needsSetter);
// We need to output the fields for non-native classes so we can auto-
// generate the constructor. For native classes there are no
// constructors, so we don't need the fields unless we are generating
// accessors at runtime.
if (!classIsNative || needsAccessor) {
// Emit correct commas.
if (isFirstField) {
isFirstField = false;
} else {
buffer.add(',');
}
int flag = 0;
if (!needsAccessor) {
// Emit field for constructor generation.
assert(!classIsNative);
buffer.add(name);
} else {
// Emit (possibly renaming) field name so we can add accessors at
// runtime.
buffer.add(accessorName);
if (name != accessorName) {
buffer.add(':$name');
// Only the native classes can have renaming accessors.
assert(classIsNative);
flag = RENAMING_FLAG;
}
}
if (needsGetter && needsSetter) {
buffer.addCharCode(GETTER_SETTER_CODE + flag);
} else if (needsGetter) {
buffer.addCharCode(GETTER_CODE + flag);
} else if (needsSetter) {
buffer.addCharCode(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 (!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));
if (classElement.isNative()) {
nativeEmitter.generateNativeClass(classElement);
return;
}
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);
js.Expression init =
js.assign(
js.use(classesCollector).dot(className),
builder.toObjectInitializer());
buffer.add(js.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);
}
void emitInterceptorMethods(ClassBuilder builder) {
JavaScriptBackend backend = compiler.backend;
// Emit forwarders for the ObjectInterceptor class. We need to
// emit all possible sends on intercepted methods.
for (Selector selector in
backend.usedInterceptors.toList()..sort(_compareSelectorNames)) {
List<js.Parameter> parameters = <js.Parameter>[];
List<js.Expression> arguments = <js.Expression>[];
parameters.add(new js.Parameter('receiver'));
String name = backend.namer.invocationName(selector);
if (selector.isSetter()) {
parameters.add(new js.Parameter('value'));
arguments.add(new js.VariableUse('value'));
} else {
for (int i = 0; i < selector.argumentCount; i++) {
String argName = 'a$i';
parameters.add(new js.Parameter(argName));
arguments.add(new js.VariableUse(argName));
}
}
js.Fun function =
new js.Fun(parameters,
new js.Block(
<js.Statement>[
new js.Return(
new js.VariableUse('receiver')
.dot(name)
.callWith(arguments))]));
builder.addProperty(name, function);
}
}
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);
}
JavaScriptBackend jsBackend = compiler.backend;
RuntimeTypeInformation rti = jsBackend.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) {
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);
JavaScriptBackend backend = compiler.backend;
// 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.keys) {
if (!needed.contains(interceptor)) {
unneededClasses.add(interceptor);
}
}
return (ClassElement cls) => !unneededClasses.contains(cls);
}
void emitClasses(CodeBuffer buffer) {
// Compute the required type checks to know which classes need a
// 'is$' method.
computeRequiredTypeChecks();
List<ClassElement> sortedClasses =
new List<ClassElement>.from(neededClasses);
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) {
generateClass(element, 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, buffer);
}
}
void emitFinishClassesInvocationIfNecessary(CodeBuffer buffer) {
if (needsDefineClass) {
buffer.add("$finishClassesName($classesCollector)$N");
// Reset the map.
buffer.add("$classesCollector$_=$_{}$N");
}
}
void emitStaticFunction(CodeBuffer buffer,
String name,
js.Expression functionExpression) {
js.Expression assignment =
js.assign(js.use(isolateProperties).dot(name), functionExpression);
buffer.add(js.prettyPrint(assignment, compiler));
buffer.add('$N$n');
}
void emitStaticFunctions(CodeBuffer buffer) {
JavaScriptBackend backend = compiler.backend;
bool isStaticFunction(Element element) =>
!element.isInstanceMember() && !element.isField();
Iterable<Element> elements =
backend.generatedCode.keys.where(isStaticFunction);
Set<Element> pendingElementsWithBailouts =
backend.generatedBailoutCode.keys
.where(isStaticFunction)
.toSet();
for (Element element in Elements.sortedByPosition(elements)) {
js.Expression code = backend.generatedCode[element];
emitStaticFunction(buffer, namer.getName(element), code);
js.Expression bailoutCode = backend.generatedBailoutCode[element];
if (bailoutCode != null) {
pendingElementsWithBailouts.remove(element);
emitStaticFunction(buffer, namer.getBailoutName(element), bailoutCode);
}
}
// Is it possible the primary function was inlined but the bailout was not?
for (Element element in
Elements.sortedByPosition(pendingElementsWithBailouts)) {
js.Expression bailoutCode = backend.generatedBailoutCode[element];
emitStaticFunction(buffer, namer.getBailoutName(element), bailoutCode);
}
}
void emitStaticFunctionGetters(CodeBuffer buffer) {
Set<FunctionElement> functionsNeedingGetter =
compiler.codegenWorld.staticFunctionsNeedingGetter;
for (FunctionElement element in
Elements.sortedByPosition(functionsNeedingGetter)) {
// The static function does not have the correct name. Since
// [addParameterStubs] use the name to create its stubs we simply
// create a fake element with the correct name.
// Note: the callElement will not have any enclosingElement.
FunctionElement callElement =
new ClosureInvocationElement(namer.closureInvocationSelectorName,
element);
String staticName = namer.getName(element);
String invocationName = namer.instanceMethodName(callElement);
String fieldAccess = '$isolateProperties.$staticName';
buffer.add("$fieldAccess.$invocationName$_=$_$fieldAccess$N");
addParameterStubs(callElement, (String name, js.Expression value) {
js.Expression assignment =
js.assign(
js.use(isolateProperties).dot(staticName).dot(name),
value);
buffer.add(
js.prettyPrint(new js.ExpressionStatement(assignment), compiler));
buffer.add('$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);
// $call3(x, y, z) { return self[name](x, y, z); }
// }
// TODO(floitsch): share the closure classes with other classes
// if they share methods with the same signature. Currently we do this only
// if there are no optional parameters. Closures with optional parameters
// are more difficult to canonicalize because they would need to have the
// same default values.
bool hasOptionalParameters = member.optionalParameterCount(compiler) != 0;
int parameterCount = member.parameterCount(compiler);
Map<int, String> cache;
String extraArg = null;
// Methods on interceptor classes take an extra parameter, which is the
// actual receiver of the call.
JavaScriptBackend backend = compiler.backend;
bool inInterceptor = backend.isInterceptorClass(member.getEnclosingClass());
if (inInterceptor) {
cache = interceptorClosureCache;
extraArg = 'receiver';
} else {
cache = boundClosureCache;
}
List<String> fieldNames = compiler.enableMinification
? inInterceptor ? const ['a', 'b', 'c']
: const ['a', 'b']
: inInterceptor ? const ['self', 'target', 'receiver']
: const ['self', 'target'];
Iterable<Element> typedefChecks =
getTypedefChecksOn(member.computeType(compiler));
bool hasTypedefChecks = !typedefChecks.isEmpty;
bool canBeShared = !hasOptionalParameters && !hasTypedefChecks;
String closureClass = canBeShared ? cache[parameterCount] : null;
if (closureClass == null) {
// Either the class was not cached yet, or there are optional parameters.
// Create a new closure class.
String name;
if (canBeShared) {
if (inInterceptor) {
name = 'BoundClosure\$i${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<js.Expression> arguments = <js.Expression>[];
if (inInterceptor) {
arguments.add(js.use('this').dot(fieldNames[2]));
}
for (int i = 0; i < parameterCount; i++) {
String name = 'p$i';
parameters.add(name);
arguments.add(js.use(name));
}
js.Expression fun =
js.fun(parameters,
js.block1(
js.return_(
new js.PropertyAccess(
js.use('this').dot(fieldNames[0]),
js.use('this').dot(fieldNames[1]))
.callWith(arguments))));
boundClosureBuilder.addProperty(invocationName, fun);
addParameterStubs(callElement, boundClosureBuilder.addProperty);
typedefChecks.forEach((Element typedef) {
String operator = namer.operatorIs(typedef);
boundClosureBuilder.addProperty(operator, new js.LiteralBool(true));
});
js.Expression init =
js.assign(
js.use(classesCollector).dot(mangledName),
boundClosureBuilder.toObjectInitializer());
boundClosureBuffer.add(js.prettyPrint(init, compiler));
boundClosureBuffer.add("$N");
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<js.Expression> arguments = <js.Expression>[];
arguments.add(js.use('this'));
arguments.add(js.string(targetName));
if (inInterceptor) {
parameters.add(extraArg);
arguments.add(js.use(extraArg));
}
js.Expression getterFunction =
js.fun(parameters,
js.block1(
js.return_(
new js.New(js.use(closureClass), 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();
JavaScriptBackend backend = compiler.backend;
// If the class is an interceptor class, the stub gets the
// receiver explicitely and we need to pass it to the getter call.
bool isInterceptorClass =
backend.isInterceptorClass(member.getEnclosingClass());
const String receiverArgumentName = r'$receiver';
js.Expression buildGetter() {
if (member.isGetter()) {
String getterName = namer.getterName(member);
return new js.VariableUse('this').dot(getterName).callWith(
isInterceptorClass
? <js.Expression>[new js.VariableUse(receiverArgumentName)]
: <js.Expression>[]);
} else {
String fieldName = member.hasFixedBackendName()
? member.fixedBackendName()
: namer.instanceFieldName(member);
return new js.VariableUse('this').dot(fieldName);
}
}
// Two selectors may match but differ only in type. To avoid generating
// identical stubs for each we track untyped selectors which already have
// stubs.
Set<Selector> generatedSelectors = new Set<Selector>();
for (Selector selector in selectors) {
if (selector.applies(member, compiler)) {
selector = selector.asUntyped;
if (generatedSelectors.contains(selector)) continue;
generatedSelectors.add(selector);
String invocationName = namer.invocationName(selector);
Selector callSelector = new Selector.callClosureFrom(selector);
String closureCallName = namer.invocationName(callSelector);
List<js.Parameter> parameters = <js.Parameter>[];
List<js.Expression> arguments = <js.Expression>[];
if (isInterceptorClass) {
parameters.add(new js.Parameter(receiverArgumentName));
}
for (int i = 0; i < selector.argumentCount; i++) {
String name = 'arg$i';
parameters.add(new js.Parameter(name));
arguments.add(new js.VariableUse(name));
}
js.Fun function =
new js.Fun(parameters,
new js.Block(
<js.Statement>[
new js.Return(
buildGetter().dot(closureCallName)
.callWith(arguments))]));
defineStub(invocationName, function);
}
}
}
void emitStaticNonFinalFieldInitializations(CodeBuffer buffer) {
ConstantHandler handler = compiler.constantHandler;
Iterable<VariableElement> staticNonFinalFields =
handler.getStaticNonFinalFieldsForEmission();
for (Element element in Elements.sortedByPosition(staticNonFinalFields)) {
compiler.withCurrentElement(element, () {
Constant initialValue = handler.getInitialValueFor(element);
js.Expression init =
new js.Assignment(
new js.PropertyAccess.field(
new js.VariableUse(isolateProperties),
namer.getName(element)),
constantEmitter.referenceInInitializationContext(initialValue));
buffer.add(js.prettyPrint(init, compiler));
buffer.add('$N');
});
}
}
void emitLazilyInitializedStaticFields(CodeBuffer buffer) {
ConstantHandler handler = compiler.constantHandler;
List<VariableElement> lazyFields =
handler.getLazilyInitializedFieldsForEmission();
JavaScriptBackend backend = compiler.backend;
if (!lazyFields.isEmpty) {
needsLazyInitializer = true;
for (VariableElement element in Elements.sortedByPosition(lazyFields)) {
assert(backend.generatedBailoutCode[element] == null);
js.Expression code = backend.generatedCode[element];
assert(code != null);
// The code only computes the initial value. We build the lazy-check
// here:
// lazyInitializer(prototype, 'name', fieldName, getterName, initial);
// The name is used for error reporting. The 'initial' must be a
// closure that constructs the initial value.
List<js.Expression> arguments = <js.Expression>[];
arguments.add(js.use(isolateProperties));
arguments.add(js.string(element.name.slowToString()));
arguments.add(js.string(namer.getName(element)));
arguments.add(js.string(namer.getLazyInitializerName(element)));
arguments.add(code);
js.Expression getter = buildLazyInitializedGetter(element);
if (getter != null) {
arguments.add(getter);
}
js.Expression init = js.call(js.use(lazyInitializerName), arguments);
buffer.add(js.prettyPrint(init, compiler));
buffer.add("$N");
}
}
}
js.Expression buildLazyInitializedGetter(VariableElement element) {
// Nothing to do, the 'lazy' function will create the getter.
return null;
}
void emitCompileTimeConstants(CodeBuffer buffer) {
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(buffer);
}
js.Expression init =
new js.Assignment(
new js.PropertyAccess.field(
new js.VariableUse(isolateProperties),
name),
constantInitializerExpression(constant));
buffer.add(js.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>();
// Keep track of the noSuchMethod holders for each possible
// receiver type.
Map<ClassElement, Set<ClassElement>> noSuchMethodHolders =
new Map<ClassElement, Set<ClassElement>>();
Set<ClassElement> noSuchMethodHoldersFor(DartType type) {
ClassElement element = type.element;
Set<ClassElement> result = noSuchMethodHolders[element];
if (result == null) {
// For now, we check the entire world to see if an object of
// the given type may have a user-defined noSuchMethod
// implementation. We could do better by only looking at
// instantiated (or otherwise needed) classes.
result = compiler.world.findNoSuchMethodHolders(type);
noSuchMethodHolders[element] = result;
}
return result;
}
js.Expression generateMethod(String jsName, Selector selector) {
// Values match JSInvocationMirror in js-helper library.
int type = selector.invocationMirrorKind;
String methodName = selector.invocationMirrorMemberName;
List<js.Parameter> parameters = <js.Parameter>[];
CodeBuffer args = new CodeBuffer();
for (int i = 0; i < selector.argumentCount; i++) {
parameters.add(new js.Parameter('\$$i'));
}
List<js.Expression> argNames =
selector.getOrderedNamedArguments().map((SourceString name) =>
js.string(name.slowToString())).toList();
String internalName = namer.invocationMirrorInternalName(selector);
String createInvocationMirror = namer.getName(
compiler.createInvocationMirrorElement);
js.Expression expression =
new js.This()
.dot(noSuchMethodName)
.callWith(
<js.Expression>[
new js.VariableUse(namer.CURRENT_ISOLATE)
.dot(createInvocationMirror)
.callWith(
<js.Expression>[
js.string(methodName),
js.string(internalName),
new js.LiteralNumber('$type'),
new js.ArrayInitializer.from(
parameters.map((param) => js.use(param.name))
.toList()),
new js.ArrayInitializer.from(argNames)])]);
js.Expression function =
new js.Fun(parameters,
new js.Block(<js.Statement>[new js.Return(expression)]));
return function;
}
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.lookupMember(selector.name);
if (element == null) return false;
// TODO(kasperl): Consider folding this logic into the
// Selector.applies() method.
if (element is AbstractFieldElement) {
AbstractFieldElement field = element;
if (selector.isGetter()) {
return field.getter != null;
} else if (selector.isSetter()) {
return field.setter != null;
} else {
return false;
}
} else if (element is VariableElement) {
if (selector.isSetter() && element.modifiers.isFinalOrConst()) {
return false;
}
}
return selector.applies(element, compiler);
}
// 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.
DartType receiverType = objectType;
ClassElement receiverClass = objectClass;
if (selector is TypedSelector) {
TypedSelector typedSelector = selector;
receiverType = typedSelector.receiverType;
receiverClass = receiverType.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.
Set<ClassElement> holders = noSuchMethodHoldersFor(receiverType);
if (holders.every(hasMatchingMember)) continue;
String jsName = namer.invocationMirrorInternalName(selector);
if (!addedJsNames.contains(jsName)) {
js.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)}()';
}
if (!compiler.enableMinification) {
buffer.add("""
//
// BEGIN invoke [main].
//
""");
}
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};
}
}
""");
if (!compiler.enableMinification) {
buffer.add("""
//
// END invoke [main].
//
""");
}
}
void emitGetInterceptorMethod(CodeBuffer buffer,
String objectName,
String key,
Collection<ClassElement> classes) {
js.Statement buildReturnInterceptor(ClassElement cls) {
return js.return_(js.fieldAccess(js.use(namer.isolateAccess(cls)),
'prototype'));
}
js.VariableUse receiver = js.use('receiver');
JavaScriptBackend backend = compiler.backend;
/**
* Build a JavaScrit AST node for doing a type check on
* [cls]. [cls] must be an interceptor class.
*/
js.Statement buildInterceptorCheck(ClassElement cls) {
js.Expression condition;
assert(backend.isInterceptorClass(cls));
if (cls == backend.jsBoolClass) {
condition = js.equals(js.typeOf(receiver), js.string('boolean'));
} else if (cls == backend.jsIntClass ||
cls == backend.jsDoubleClass ||
cls == backend.jsNumberClass) {
throw 'internal error';
} else if (cls == backend.jsArrayClass) {
condition = js.equals(js.fieldAccess(receiver, 'constructor'),
js.use('Array'));
} else if (cls == backend.jsStringClass) {
condition = js.equals(js.typeOf(receiver), js.string('string'));
} else if (cls == backend.jsNullClass) {
condition = js.equals(receiver, new js.LiteralNull());
} else if (cls == backend.jsFunctionClass) {
condition = js.equals(js.typeOf(receiver), 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 throw 'Internal error: $cls';
}
if (hasDouble) {
assert(!hasNumber);
hasNumber = true;
}
if (hasInt) hasNumber = true;
js.Block block = new js.Block.empty();
if (hasNumber) {
js.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.
js.Return returnNumberClass = buildReturnInterceptor(
hasDouble ? backend.jsDoubleClass : backend.jsNumberClass);
if (hasInt) {
js.Expression isInt =
js.equals(js.call(js.fieldAccess(js.use('Math'), 'floor'),
[receiver]),
receiver);
(whenNumber = js.emptyBlock()).statements
..add(js.if_(isInt, buildReturnInterceptor(backend.jsIntClass)))
..add(returnNumberClass);
} else {
whenNumber = returnNumberClass;
}
block.statements.add(
js.if_(js.equals(js.typeOf(receiver), 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_(js.equals(receiver, new js.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_(js.fieldAccess(js.use(objectName),
'prototype')));
js.PropertyAccess name = js.fieldAccess(js.use(isolateProperties), key);
buffer.add(js.prettyPrint(js.assign(name, js.fun(['receiver'], block)),
compiler));
buffer.add(N);
}
/**
* Emit all versions of the [:getInterceptor:] method.
*/
void emitGetInterceptorMethods(CodeBuffer buffer) {
JavaScriptBackend backend = compiler.backend;
// If no class needs to be intercepted, just return.
if (backend.objectInterceptorClass == null) return;
String objectName = namer.isolateAccess(backend.objectInterceptorClass);
var specializedGetInterceptors = backend.specializedGetInterceptors;
for (String name in specializedGetInterceptors.keys.toList()..sort()) {
Collection<ClassElement> classes = specializedGetInterceptors[name];
emitGetInterceptorMethod(buffer, objectName, name, classes);
}
}
void computeNeededClasses() {
instantiatedClasses =
compiler.codegenWorld.instantiatedClasses.where(computeClassFilter())
.toSet();
neededClasses = new Set<ClassElement>.from(instantiatedClasses);
for (ClassElement element in instantiatedClasses) {
for (ClassElement superclass = element.superclass;
superclass != null;
superclass = superclass.superclass) {
if (neededClasses.contains(superclass)) break;
neededClasses.add(superclass);
}
}
}
int _compareSelectors(Selector selector1, Selector selector2) {
int comparison = _compareSelectorNames(selector1, selector2);
if (comparison != 0) return comparison;
JavaScriptBackend backend = compiler.backend;
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);
}
void emitOneShotInterceptors(CodeBuffer buffer) {
JavaScriptBackend backend = compiler.backend;
for (Selector selector in
backend.oneShotInterceptors.toList()..sort(_compareSelectors)) {
Set<ClassElement> classes = backend.getInterceptedClassesOn(selector);
String oneShotInterceptorName = namer.oneShotInterceptorName(selector);
String getInterceptorName =
namer.getInterceptorName(backend.getInterceptorMethod, classes);
List<js.Parameter> parameters = <js.Parameter>[];
List<js.Expression> arguments = <js.Expression>[];
parameters.add(new js.Parameter('receiver'));
arguments.add(js.use('receiver'));
if (selector.isSetter()) {
parameters.add(new js.Parameter('value'));
arguments.add(js.use('value'));
} else {
for (int i = 0; i < selector.argumentCount; i++) {
String argName = 'a$i';
parameters.add(new js.Parameter(argName));
arguments.add(js.use(argName));
}
}
String invocationName = backend.namer.invocationName(selector);
js.Fun function =
new js.Fun(parameters,
js.block1(js.return_(
js.use(isolateProperties)
.dot(getInterceptorName)
.callWith([js.use('receiver')])
.dot(invocationName)
.callWith(arguments))));
js.PropertyAccess property =
js.fieldAccess(js.use(isolateProperties), oneShotInterceptorName);
buffer.add(js.prettyPrint(js.assign(property, function), compiler));
buffer.add(N);
}
}
String assembleProgram() {
measure(() {
computeNeededClasses();
mainBuffer.add(GENERATED_BY);
if (!compiler.enableMinification) mainBuffer.add(HOOKS_API_USAGE);
mainBuffer.add('function ${namer.isolateName}()$_{}\n');
mainBuffer.add('init()$N$n');
// Shorten the code by using "$$" as temporary.
classesCollector = r"$$";
mainBuffer.add('var $classesCollector$_=$_{}$N');
// Shorten the code by using [namer.CURRENT_ISOLATE] as temporary.
isolateProperties = namer.CURRENT_ISOLATE;
mainBuffer.add(
'var $isolateProperties$_=$_$isolatePropertiesName$N');
emitClasses(mainBuffer);
mainBuffer.add(boundClosureBuffer);
// Clear the buffer, so that we can reuse it for the native classes.
boundClosureBuffer.clear();
emitStaticFunctions(mainBuffer);
emitStaticFunctionGetters(mainBuffer);
// We need to finish the classes before we construct compile time
// constants.
emitFinishClassesInvocationIfNecessary(mainBuffer);
emitRuntimeClassesAndTests(mainBuffer);
emitCompileTimeConstants(mainBuffer);
// Static field initializations require the classes and compile-time
// constants to be set up.
emitStaticNonFinalFieldInitializations(mainBuffer);
emitOneShotInterceptors(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');
mainBuffer.add(boundClosureBuffer);
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';
emitFinishIsolateConstructorInvocation(mainBuffer);
mainBuffer.add('var ${namer.CURRENT_ISOLATE}$_='
'${_}new ${namer.isolateName}()$N');
nativeEmitter.assembleCode(mainBuffer);
emitMain(mainBuffer);
mainBuffer.add('function init()$_{\n');
mainBuffer.add('$isolateProperties$_=$_{}$N');
addDefineClassAndFinishClassFunctionsIfNecessary(mainBuffer);
addLazyInitializerFunctionIfNecessary(mainBuffer);
emitFinishIsolateConstructor(mainBuffer);
mainBuffer.add('}\n');
compiler.assembledCode = mainBuffer.getText();
if (generateSourceMap) {
SourceFile compiledFile = new SourceFile(null, compiler.assembledCode);
String sourceMap = buildSourceMap(mainBuffer, compiledFile);
compiler.outputProvider('', 'js.map')
..add(sourceMap)
..close();
}
});
return compiler.assembledCode;
}
String buildSourceMap(CodeBuffer buffer, SourceFile compiledFile) {
SourceMapBuilder sourceMapBuilder = new SourceMapBuilder();
buffer.forEachSourceLocation(sourceMapBuilder.addMapping);
return sourceMapBuilder.build(compiledFile);
}
}
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].
""";