Files
sdk/lib/compiler/implementation/elements/elements.dart
T
2012-08-21 14:36:38 +00:00

1569 lines
52 KiB
Dart

// 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.
#library('elements');
#import('dart:uri');
#import('../tree/tree.dart');
#import('../scanner/scannerlib.dart');
#import('../leg.dart'); // TODO(karlklose): we only need type.
#import('../util/util.dart');
class ElementCategory {
/**
* Represents things that we don't expect to find when looking in a
* scope.
*/
static final int NONE = 0;
/** Field, parameter, or variable. */
static final int VARIABLE = 1;
/** Function, method, or foreign function. */
static final int FUNCTION = 2;
static final int CLASS = 4;
static final int PREFIX = 8;
/** Constructor or factory. */
static final int FACTORY = 16;
static final int ALIAS = 32;
static final int SUPER = 64;
/** Type variable */
static final int TYPE_VARIABLE = 128;
static final int IMPLIES_TYPE = CLASS | ALIAS | TYPE_VARIABLE;
static final int IS_EXTENDABLE = CLASS | ALIAS;
}
class ElementKind {
final String id;
final int category;
const ElementKind(String this.id, this.category);
static final ElementKind VARIABLE =
const ElementKind('variable', ElementCategory.VARIABLE);
static final ElementKind PARAMETER =
const ElementKind('parameter', ElementCategory.VARIABLE);
// Parameters in constructors that directly initialize fields. For example:
// [:A(this.field):].
static final ElementKind FIELD_PARAMETER =
const ElementKind('field_parameter', ElementCategory.VARIABLE);
static final ElementKind FUNCTION =
const ElementKind('function', ElementCategory.FUNCTION);
static final ElementKind CLASS =
const ElementKind('class', ElementCategory.CLASS);
static final ElementKind FOREIGN =
const ElementKind('foreign', ElementCategory.FUNCTION);
static final ElementKind GENERATIVE_CONSTRUCTOR =
const ElementKind('generative_constructor', ElementCategory.FACTORY);
static final ElementKind FIELD =
const ElementKind('field', ElementCategory.VARIABLE);
static final ElementKind VARIABLE_LIST =
const ElementKind('variable_list', ElementCategory.NONE);
static final ElementKind FIELD_LIST =
const ElementKind('field_list', ElementCategory.NONE);
static final ElementKind GENERATIVE_CONSTRUCTOR_BODY =
const ElementKind('generative_constructor_body', ElementCategory.NONE);
static final ElementKind COMPILATION_UNIT =
const ElementKind('compilation_unit', ElementCategory.NONE);
static final ElementKind GETTER =
const ElementKind('getter', ElementCategory.NONE);
static final ElementKind SETTER =
const ElementKind('setter', ElementCategory.NONE);
static final ElementKind TYPE_VARIABLE =
const ElementKind('type_variable', ElementCategory.TYPE_VARIABLE);
static final ElementKind ABSTRACT_FIELD =
const ElementKind('abstract_field', ElementCategory.VARIABLE);
static final ElementKind LIBRARY =
const ElementKind('library', ElementCategory.NONE);
static final ElementKind COMPILATION_UNIT_OVERRIDE =
const ElementKind('compilation_unit_override', ElementCategory.NONE);
static final ElementKind PREFIX =
const ElementKind('prefix', ElementCategory.PREFIX);
static final ElementKind TYPEDEF =
const ElementKind('typedef', ElementCategory.ALIAS);
static final ElementKind STATEMENT =
const ElementKind('statement', ElementCategory.NONE);
static final ElementKind LABEL =
const ElementKind('label', ElementCategory.NONE);
static final ElementKind VOID =
const ElementKind('void', ElementCategory.NONE);
toString() => id;
}
class Element implements Hashable {
final SourceString name;
final ElementKind kind;
final Element enclosingElement;
Link<Node> metadata = const EmptyLink<Node>();
Element(this.name, this.kind, this.enclosingElement) {
assert(getLibrary() !== null);
}
Modifiers get modifiers() => null;
Node parseNode(DiagnosticListener listener) {
listener.cancel("Internal Error: $this.parseNode", token: position());
}
Type computeType(Compiler compiler) {
compiler.internalError("$this.computeType.", token: position());
}
void addMetadata(Node node) {
metadata = metadata.prepend(node);
}
bool isFunction() => kind === ElementKind.FUNCTION;
bool isConstructor() => isFactoryConstructor() || isGenerativeConstructor();
bool isClosure() => false;
bool isMember() {
// Check that this element is defined in the scope of a Class.
Element enclosing = enclosingElement;
if (enclosing !== null &&
enclosing.kind === ElementKind.COMPILATION_UNIT_OVERRIDE) {
enclosing = enclosing.enclosingElement;
}
return enclosing !== null && enclosing.isClass();
}
bool isInstanceMember() => false;
bool isFactoryConstructor() => modifiers !== null && modifiers.isFactory();
bool isGenerativeConstructor() => kind === ElementKind.GENERATIVE_CONSTRUCTOR;
bool isGenerativeConstructorBody() =>
kind === ElementKind.GENERATIVE_CONSTRUCTOR_BODY;
bool isCompilationUnit() => kind === ElementKind.COMPILATION_UNIT;
bool isClass() => kind === ElementKind.CLASS;
bool isPrefix() => kind === ElementKind.PREFIX;
bool isVariable() => kind === ElementKind.VARIABLE;
bool isParameter() => kind === ElementKind.PARAMETER;
bool isStatement() => kind === ElementKind.STATEMENT;
bool isTypedef() => kind === ElementKind.TYPEDEF;
bool isTypeVariable() => kind === ElementKind.TYPE_VARIABLE;
bool isField() => kind === ElementKind.FIELD;
bool isGetter() => kind === ElementKind.GETTER;
bool isSetter() => kind === ElementKind.SETTER;
bool isAccessor() => isGetter() || isSetter();
bool isForeign() => kind === ElementKind.FOREIGN;
bool isLibrary() => kind === ElementKind.LIBRARY;
bool impliesType() => (kind.category & ElementCategory.IMPLIES_TYPE) != 0;
bool isExtendable() => (kind.category & ElementCategory.IS_EXTENDABLE) != 0;
/** See [ErroneousElement] for documentation. */
bool isErroneous() => false;
// TODO(johnniwinther): This breaks for libraries (for which enclosing
// elements are null) and is invalid for top level variable declarations for
// which the enclosing element is a VariableDeclarations and not a compilation
// unit.
bool isTopLevel() {
return enclosingElement !== null && enclosingElement.isCompilationUnit();
}
bool isAssignable() {
if (modifiers != null && modifiers.isFinal()) return false;
if (isFunction() || isGenerativeConstructor()) return false;
return true;
}
Token position() => null;
Token findMyName(Token token) {
for (Token t = token; t.kind !== EOF_TOKEN; t = t.next) {
if (t.value == name) return t;
}
return token;
}
// TODO(kasperl): This is a very bad hash code for the element and
// there's no reason why two elements with the same name should have
// the same hash code. Replace this with a simple id in the element?
int hashCode() => name === null ? 0 : name.hashCode();
CompilationUnitElement getCompilationUnit() {
Element element = this;
while (element !== null && !element.isCompilationUnit()) {
if (element is CompilationUnitOverrideElement) {
CompilationUnitOverrideElement override = element;
return override.compilationUnit;
}
if (element.isLibrary()) {
LibraryElement library = element;
return library.entryCompilationUnit;
}
element = element.enclosingElement;
if (element is FunctionElement) {
FunctionElement function = element;
if (function.isPatched) {
element = function.patch;
}
}
}
return element;
}
LibraryElement getLibrary() {
Element element = this;
while (element.kind !== ElementKind.LIBRARY) {
element = element.enclosingElement;
}
return element;
}
ClassElement getEnclosingClass() {
for (Element e = this; e !== null; e = e.enclosingElement) {
if (e.isClass()) return e;
}
return null;
}
Element getEnclosingClassOrCompilationUnit() {
for (Element e = this; e !== null; e = e.enclosingElement) {
if (e.isClass() || e.isCompilationUnit()) return e;
}
return null;
}
Element getEnclosingMember() {
for (Element e = this; e !== null; e = e.enclosingElement) {
if (e.isMember()) return e;
}
return null;
}
Element getOutermostEnclosingMemberOrTopLevel() {
// TODO(lrn): Why is this called "Outermost"?
for (Element e = this; e !== null; e = e.enclosingElement) {
if (e.isMember() || e.isTopLevel()) {
return e;
}
}
return null;
}
/**
* Creates the scope for this element. The scope of the
* enclosing element will be the parent scope.
*/
Scope buildScope() => buildEnclosingScope();
/**
* Creates the scope for the enclosing element.
*/
Scope buildEnclosingScope() => enclosingElement.buildScope();
String toString() {
// TODO(johnniwinther): Test for nullness of name, or make non-nullness an
// invariant for all element types?
var nameText = name !== null ? name.slowToString() : '?';
if (enclosingElement !== null && !isTopLevel()) {
String holderName = enclosingElement.name !== null
? enclosingElement.name.slowToString()
: '${enclosingElement.kind}?';
return '$kind($holderName#${nameText})';
} else {
return '$kind(${nameText})';
}
}
bool _isNative = false;
void setNative() { _isNative = true; }
bool isNative() => _isNative;
FunctionElement asFunctionElement() => null;
Element cloneTo(Element enclosing, DiagnosticListener listener) {
listener.cancel("Unimplemented cloneTo", element: this);
}
static bool isInvalid(Element e) => e == null || e.isErroneous();
}
/**
* Represents an unresolvable or duplicated element.
*
* An [ErroneousElement] is used instead of [null] to provide additional
* information about the error that caused the element to be unresolvable
* or otherwise invalid.
*
* Accessing any field or calling any method defined on [Element] except
* [isValid] will currently throw an exception. (This might change when we
* actually want more information on the erroneous element, e.g., the name
* of the element we were trying to resolve.)
*
* Code that cannot not handle an [ErroneousElement] should use
* [: Element.isInvalid(element) :]
* to check for unresolvable elements instead of
* [: element == null :].
*/
class ErroneousElement extends Element {
final Message errorMessage;
ErroneousElement(this.errorMessage, Element enclosing)
: super(const SourceString('erroneous element'), null, enclosing);
isErroneous() => true;
unsupported() {
throw 'unsupported operation on erroneous element';
}
SourceString get name() => unsupported();
ElementKind get kind() => unsupported();
Link<Node> get metadata() => unsupported();
}
class ErroneousFunctionElement extends ErroneousElement
implements FunctionElement {
ErroneousFunctionElement(errorMessage, Element enclosing)
: super(errorMessage, enclosing);
get type() => unsupported();
get cachedNode() => unsupported();
get functionSignature() => unsupported();
get patch() => unsupported();
get defaultImplementation() => unsupported();
bool get isPatched() => unsupported();
setPatch(patch) => unsupported();
computeSignature(compiler) => unsupported();
requiredParameterCount(compiler) => unsupported();
optionalParameterCount(compiler) => unsupported();
parameterCount(copmiler) => unsupported();
getLibrary() => enclosingElement.getLibrary();
}
class ContainerElement extends Element {
Link<Element> localMembers = const EmptyLink<Element>();
ContainerElement(name, kind, enclosingElement)
: super(name, kind, enclosingElement);
void addMember(Element element, DiagnosticListener listener) {
localMembers = localMembers.prepend(element);
}
}
class ScopeContainerElement extends ContainerElement {
final Map<SourceString, Element> localScope;
ScopeContainerElement(name, kind, enclosingElement)
: super(name, kind, enclosingElement),
localScope = new Map<SourceString, Element>();
void addMember(Element element, DiagnosticListener listener) {
super.addMember(element, listener);
addToScope(element, listener);
}
void addToScope(Element element, DiagnosticListener listener) {
if (element.isAccessor()) {
addGetterOrSetter(element, localScope[element.name], listener);
} else {
Element existing = localScope.putIfAbsent(element.name, () => element);
if (existing !== element) {
// TODO(ahe): Do something similar to Resolver.reportErrorWithContext.
listener.cancel('duplicate definition', token: element.position());
listener.cancel('existing definition', token: existing.position());
}
}
}
Element localLookup(SourceString elementName) {
return localScope[elementName];
}
void addGetterOrSetter(FunctionElement element,
Element existing,
DiagnosticListener listener) {
void reportError(Element other) {
// TODO(ahe): Do something similar to Resolver.reportErrorWithContext.
listener.cancel('duplicate definition of ${element.name.slowToString()}',
element: element);
listener.cancel('existing definition', element: other);
}
if (existing != null) {
if (existing.kind !== ElementKind.ABSTRACT_FIELD) {
reportError(existing);
} else {
AbstractFieldElement field = existing;
if (element.kind == ElementKind.GETTER) {
if (field.getter != null && field.getter != element) {
reportError(field.getter);
}
field.getter = element;
} else {
if (field.setter != null && field.setter != element) {
reportError(field.setter);
}
field.setter = element;
}
}
} else {
Element container = element.getEnclosingClassOrCompilationUnit();
AbstractFieldElement field =
new AbstractFieldElement(element.name, container);
if (element.kind == ElementKind.GETTER) {
field.getter = element;
} else {
field.setter = element;
}
addMember(field, listener);
}
}
}
class CompilationUnitElement extends ContainerElement {
final Script script;
CompilationUnitElement(Script script, Element enclosing)
: this.script = script,
super(new SourceString(script.name),
ElementKind.COMPILATION_UNIT,
enclosing);
void addMember(Element element, DiagnosticListener listener) {
// Keep a list of top level members.
super.addMember(element, listener);
// Provide the member to the library to build scope.
getLibrary().addMember(element, listener);
}
}
class CompilationUnitOverrideElement extends Element {
final CompilationUnitElement compilationUnit;
CompilationUnitOverrideElement(CompilationUnitElement compilationUnit,
Element enclosing)
: this.compilationUnit = compilationUnit,
super(compilationUnit.name,
ElementKind.COMPILATION_UNIT_OVERRIDE,
enclosing);
}
class LibraryElement extends ScopeContainerElement {
final Uri uri;
CompilationUnitElement entryCompilationUnit;
Link<CompilationUnitElement> compilationUnits =
const EmptyLink<CompilationUnitElement>();
Link<ScriptTag> tags = const EmptyLink<ScriptTag>();
ScriptTag libraryTag;
bool canUseNative = false;
LibraryElement patch = null;
LibraryElement(Script script, [Uri uri])
: this.uri = ((uri === null) ? script.uri : uri),
super(new SourceString(script.name), ElementKind.LIBRARY, null) {
entryCompilationUnit = new CompilationUnitElement(script, this);
}
bool get isPatched() => patch !== null;
void addCompilationUnit(CompilationUnitElement element) {
compilationUnits = compilationUnits.prepend(element);
}
void addTag(ScriptTag tag, DiagnosticListener listener) {
tags = tags.prepend(tag);
}
/** Look up a top-level element in this library. The element could
* potentially have been imported from another library. Returns
* null if no such element exist. */
Element find(SourceString elementName) {
return localScope[elementName];
}
/** Look up a top-level element in this library, but only look for
* non-imported elements. Returns null if no such element exist. */
Element findLocal(SourceString elementName) {
Element result = localScope[elementName];
if (result === null || result.getLibrary() != this) return null;
return result;
}
void forEachExport(f(Element element)) {
localScope.forEach((_, Element e) {
if (this === e.getLibrary()
&& e.kind !== ElementKind.PREFIX
&& e.kind !== ElementKind.FOREIGN
&& !e.name.isPrivate()) {
f(e);
}
});
}
bool hasLibraryName() => libraryTag !== null;
/**
* Returns the library name (as defined by the #library tag) or for script
* (which have no #library tag) the script file name. The latter case is used
* to private 'library name' for scripts to use for instance in dartdoc.
*/
String getLibraryOrScriptName() {
if (libraryTag !== null) {
return libraryTag.argument.dartString.slowToString();
} else {
// Use the file name as script name.
String path = uri.path;
return path.substring(path.lastIndexOf('/') + 1);
}
}
Scope buildEnclosingScope() => new TopScope(this);
bool get isPlatformLibrary => uri.scheme == "dart";
}
class PrefixElement extends Element {
Map<SourceString, Element> imported;
Token firstPosition;
PrefixElement(SourceString prefix, Element enclosing, this.firstPosition)
: imported = new Map<SourceString, Element>(),
super(prefix, ElementKind.PREFIX, enclosing);
lookupLocalMember(SourceString memberName) => imported[memberName];
Type computeType(Compiler compiler) => compiler.types.dynamicType;
Token position() => firstPosition;
PrefixElement cloneTo(Element enclosing, DiagnosticListener listener) {
return new PrefixElement(name, enclosing, firstPosition);
}
}
class TypedefElement extends Element implements TypeDeclarationElement {
Typedef cachedNode;
TypedefType cachedType;
Type alias;
bool isResolved = false;
bool isBeingResolved = false;
TypedefElement(SourceString name, Element enclosing)
: super(name, ElementKind.TYPEDEF, enclosing);
/**
* Function signature for a typedef of a function type. The signature is
* kept to provide full information about parameter names through the mirror
* system.
*
* The [functionSignature] is not available until the typedef element has been
* resolved.
*/
FunctionSignature functionSignature;
TypedefType computeType(Compiler compiler) {
if (cachedType !== null) return cachedType;
Typedef node = parseNode(compiler);
Link<Type> parameters =
TypeDeclarationElement.createTypeVariables(this, node.typeParameters);
cachedType = new TypedefType(this, parameters);
compiler.resolveTypedef(this);
return cachedType;
}
Link<Type> get typeVariables() => cachedType.typeArguments;
Scope buildScope() =>
new TypeDeclarationScope(enclosingElement.buildScope(), this);
TypedefElement cloneTo(Element enclosing, DiagnosticListener listener) {
TypedefElement result = new TypedefElement(name, enclosing);
return result;
}
}
class VariableElement extends Element {
final VariableListElement variables;
Expression cachedNode; // The send or the identifier in the variables list.
Modifiers get modifiers() => variables.modifiers;
VariableElement(SourceString name,
VariableListElement this.variables,
ElementKind kind,
Element enclosing,
[Node node])
: super(name, kind, enclosing), cachedNode = node;
Node parseNode(DiagnosticListener listener) {
if (cachedNode !== null) return cachedNode;
VariableDefinitions definitions = variables.parseNode(listener);
for (Link<Node> link = definitions.definitions.nodes;
!link.isEmpty(); link = link.tail) {
Expression initializedIdentifier = link.head;
Identifier identifier = initializedIdentifier.asIdentifier();
if (identifier === null) {
identifier = initializedIdentifier.asSendSet().selector.asIdentifier();
}
if (name === identifier.source) {
cachedNode = initializedIdentifier;
return cachedNode;
}
}
listener.cancel('internal error: could not find $name', node: variables);
}
Type computeType(Compiler compiler) {
return variables.computeType(compiler);
}
Type get type() => variables.type;
bool isInstanceMember() {
return isMember() && !modifiers.isStatic();
}
// Note: cachedNode.getBeginToken() will not be correct in all
// cases, for example, for function typed parameters.
Token position() => findMyName(variables.position());
VariableElement cloneTo(Element enclosing, DiagnosticListener listener) {
VariableListElement clonedVariables =
variables.cloneTo(enclosing, listener);
VariableElement result = new VariableElement(
name, clonedVariables, kind, enclosing, cachedNode);
return result;
}
}
/**
* Parameters in constructors that directly initialize fields. For example:
* [:A(this.field):].
*/
class FieldParameterElement extends VariableElement {
VariableElement fieldElement;
FieldParameterElement(SourceString name,
this.fieldElement,
VariableListElement variables,
Element enclosing,
Node node)
: super(name, variables, ElementKind.FIELD_PARAMETER, enclosing, node);
FieldParameterElement cloneTo(Element enclosing,
DiagnosticListener listener) {
FieldParameterElement result =
new FieldParameterElement(name, fieldElement,
variables.cloneTo(enclosing, listener),
enclosing, cachedNode);
return result;
}
}
// This element represents a list of variable or field declaration.
// It contains the node, and the type. A [VariableElement] always
// references its [VariableListElement]. It forwards its
// [computeType] and [parseNode] methods to this element.
class VariableListElement extends Element {
VariableDefinitions cachedNode;
Type type;
final Modifiers modifiers;
/**
* Function signature for a variable with a function type. The signature is
* kept to provide full information about parameter names through the mirror
* system.
*/
FunctionSignature functionSignature;
VariableListElement(ElementKind kind,
Modifiers this.modifiers,
Element enclosing)
: super(null, kind, enclosing);
VariableListElement.node(VariableDefinitions node,
ElementKind kind,
Element enclosing)
: super(null, kind, enclosing),
this.cachedNode = node,
this.modifiers = node.modifiers;
VariableDefinitions parseNode(DiagnosticListener listener) {
return cachedNode;
}
Type computeType(Compiler compiler) {
if (type != null) return type;
VariableDefinitions node = parseNode(compiler);
if (node.type !== null) {
type = compiler.resolveTypeAnnotation(this, node.type);
} else {
// Is node.definitions exactly one FunctionExpression?
Link<Node> link = node.definitions.nodes;
if (!link.isEmpty() &&
link.head.asFunctionExpression() !== null &&
link.tail.isEmpty()) {
FunctionExpression functionExpression = link.head;
// We found exactly one FunctionExpression
compiler.withCurrentElement(this, () {
functionSignature =
compiler.resolveFunctionExpression(this, functionExpression);
});
type = compiler.computeFunctionType(compiler.functionClass,
functionSignature);
} else {
type = compiler.types.dynamicType;
}
}
assert(type != null);
return type;
}
Token position() => cachedNode.getBeginToken();
VariableListElement cloneTo(Element enclosing, DiagnosticListener listener) {
VariableListElement result;
if (cachedNode !== null) {
result = new VariableListElement.node(cachedNode, kind, enclosing);
} else {
result = new VariableListElement(kind, modifiers, enclosing);
}
return result;
}
}
class ForeignElement extends Element {
ForeignElement(SourceString name, ContainerElement enclosingElement)
: super(name, ElementKind.FOREIGN, enclosingElement);
Type computeType(Compiler compiler) {
return compiler.types.dynamicType;
}
parseNode(DiagnosticListener listener) {
throw "internal error: ForeignElement has no node";
}
ForeignElement cloneTo(Element enclosing, DiagnosticListener listener) {
ForeignElement result = new ForeignElement(name, enclosing);
return result;
}
}
class AbstractFieldElement extends Element {
FunctionElement getter;
FunctionElement setter;
AbstractFieldElement(SourceString name, Element enclosing)
: super(name, ElementKind.ABSTRACT_FIELD, enclosing);
Type computeType(Compiler compiler) {
throw "internal error: AbstractFieldElement has no type";
}
Node parseNode(DiagnosticListener listener) {
throw "internal error: AbstractFieldElement has no node";
}
position() {
// The getter and setter may be defined in two different
// compilation units. However, we know that one of them is
// non-null and defined in the same compilation unit as the
// abstract element.
// TODO(lrn): No we don't know that if the element from the same
// compilation unit is patched.
//
// We need to make sure that the position returned is relative to
// the compilation unit of the abstract element.
if (getter !== null
&& getter.getCompilationUnit() === getCompilationUnit()) {
return getter.position();
} else {
return setter.position();
}
}
Modifiers get modifiers() {
// The resolver ensures that the flags match (ignoring abstract).
if (getter !== null) {
return new Modifiers.withFlags(
getter.modifiers.nodes,
getter.modifiers.flags | Modifiers.FLAG_ABSTRACT);
} else {
return new Modifiers.withFlags(
setter.modifiers.nodes,
setter.modifiers.flags | Modifiers.FLAG_ABSTRACT);
}
}
AbstractFieldElement cloneTo(Element enclosing, DiagnosticListener listener) {
listener.cancel("Cannot clone synthetic AbstractFieldElement",
element: this);
}
}
// TODO(johnniwinther): [FunctionSignature] should be merged with
// [FunctionType].
class FunctionSignature {
Link<Element> requiredParameters;
Link<Element> optionalParameters;
Type returnType;
int requiredParameterCount;
int optionalParameterCount;
FunctionSignature(this.requiredParameters,
this.optionalParameters,
this.requiredParameterCount,
this.optionalParameterCount,
this.returnType);
void forEachParameter(void function(Element parameter)) {
for (Link<Element> link = requiredParameters;
!link.isEmpty();
link = link.tail) {
function(link.head);
}
for (Link<Element> link = optionalParameters;
!link.isEmpty();
link = link.tail) {
function(link.head);
}
}
int get parameterCount() => requiredParameterCount + optionalParameterCount;
}
class FunctionElement extends Element {
FunctionExpression cachedNode;
Type type;
final Modifiers modifiers;
FunctionSignature functionSignature;
/**
* A function declaration that should be parsed instead of the current one.
* The patch should be parsed as if it was in the current scope. Its
* signature must match this function's signature.
*/
// TODO(lrn): Consider using [defaultImplementation] to store the patch.
FunctionElement patch = null;
/**
* If this is an interface constructor, [defaultImplementation] will
* changed by the resolver to point to the default
* implementation. Otherwise, [:defaultImplementation === this:].
*/
FunctionElement defaultImplementation;
FunctionElement(SourceString name,
ElementKind kind,
Modifiers modifiers,
Element enclosing)
: this.tooMuchOverloading(name, null, kind, modifiers, enclosing, null);
FunctionElement.node(SourceString name,
FunctionExpression node,
ElementKind kind,
Modifiers modifiers,
Element enclosing)
: this.tooMuchOverloading(name, node, kind, modifiers, enclosing, null);
FunctionElement.from(SourceString name,
FunctionElement other,
Element enclosing)
: this.tooMuchOverloading(name, other.cachedNode, other.kind,
other.modifiers, enclosing,
other.functionSignature);
FunctionElement.tooMuchOverloading(SourceString name,
FunctionExpression this.cachedNode,
ElementKind kind,
Modifiers this.modifiers,
Element enclosing,
FunctionSignature this.functionSignature)
: super(name, kind, enclosing) {
defaultImplementation = this;
}
bool get isPatched() => patch !== null;
/**
* Applies a patch function to this function. The patch function's body
* is used as replacement when parsing this function's body.
* This method must not be called after the function has been parsed,
* and it must be called at most once.
*/
void setPatch(FunctionElement patchElement) {
// Sanity checks. The caller must check these things before calling.
assert(patch === null);
assert(cachedNode === null);
this.patch = patchElement;
cachedNode = patchElement.cachedNode;
}
bool isInstanceMember() {
return isMember()
&& !isConstructor()
&& !modifiers.isStatic();
}
FunctionSignature computeSignature(Compiler compiler) {
if (functionSignature !== null) return functionSignature;
compiler.withCurrentElement(this, () {
functionSignature = compiler.resolveSignature(this);
});
return functionSignature;
}
int requiredParameterCount(Compiler compiler) {
return computeSignature(compiler).requiredParameterCount;
}
int optionalParameterCount(Compiler compiler) {
return computeSignature(compiler).optionalParameterCount;
}
int parameterCount(Compiler compiler) {
return computeSignature(compiler).parameterCount;
}
FunctionType computeType(Compiler compiler) {
if (type != null) return type;
type = compiler.computeFunctionType(this, computeSignature(compiler));
return type;
}
Node parseNode(DiagnosticListener listener) {
if (cachedNode !== null) return cachedNode;
if (patch === null) {
if (modifiers.isExternal()) {
listener.cancel("Compiling external function with no implementation.",
element: this);
}
return null;
}
cachedNode = patch.parseNode(listener);
return cachedNode;
}
Token position() => cachedNode.getBeginToken();
FunctionElement asFunctionElement() => this;
FunctionElement cloneTo(Element enclosing, DiagnosticListener listener) {
FunctionElement result = new FunctionElement.tooMuchOverloading(
name, cachedNode, kind, modifiers, enclosing, functionSignature);
result.defaultImplementation = defaultImplementation;
result.type = type;
return result;
}
}
class ConstructorBodyElement extends FunctionElement {
FunctionElement constructor;
ConstructorBodyElement(FunctionElement constructor)
: this.constructor = constructor,
super(constructor.name,
ElementKind.GENERATIVE_CONSTRUCTOR_BODY,
null,
constructor.enclosingElement) {
functionSignature = constructor.functionSignature;
}
bool isInstanceMember() => true;
FunctionType computeType(Compiler compiler) {
compiler.reportFatalError('Internal error: $this.computeType', this);
}
Node parseNode(DiagnosticListener listener) {
if (cachedNode !== null) return cachedNode;
cachedNode = constructor.parseNode(listener);
assert(cachedNode !== null);
return cachedNode;
}
Token position() => constructor.position();
ConstructorBodyElement cloneTo(Element enclosing,
DiagnosticListener listener) {
ConstructorBodyElement result =
new ConstructorBodyElement(constructor.cloneTo(enclosing, listener));
return result;
}
}
class SynthesizedConstructorElement extends FunctionElement {
SynthesizedConstructorElement(Element enclosing)
: super(enclosing.name, ElementKind.GENERATIVE_CONSTRUCTOR,
null, enclosing);
Token position() => enclosingElement.position();
SynthesizedConstructorElement cloneTo(Element enclosing,
DiagnosticListener listener) {
return new SynthesizedConstructorElement(enclosing);
}
}
class VoidElement extends Element {
VoidElement(Element enclosing)
: super(const SourceString('void'), ElementKind.VOID, enclosing);
Type computeType(compiler) => compiler.types.voidType;
Node parseNode(_) {
throw 'internal error: parseNode on void';
}
bool impliesType() => true;
}
/**
* [TypeDeclarationElement] defines the common interface for class/interface
* declarations and typedefs.
*/
abstract class TypeDeclarationElement implements Element {
// TODO(johnniwinther): This class should eventually be a mixin.
/**
* The type variables declared on this declaration. The type variables are not
* available until the type of the element has been computed through
* [computeType].
*/
// TODO(johnniwinther): Find a (better) way to decouple [typeVariables] from
// [Compiler].
abstract Link<Type> get typeVariables();
/**
* Creates the type variables, their type and corresponding element, for the
* type variables declared in [parameter] on [element]. The bounds of the type
* variables are not set until [element] has been resolved.
*/
static Link<Type> createTypeVariables(TypeDeclarationElement element,
NodeList parameters) {
if (parameters === null) return const EmptyLink<Type>();
// Create types and elements for type variable.
var arguments = new LinkBuilder<Type>();
for (Link link = parameters.nodes; !link.isEmpty(); link = link.tail) {
TypeVariable node = link.head;
SourceString variableName = node.name.source;
TypeVariableElement variableElement =
new TypeVariableElement(variableName, element, node);
TypeVariableType variableType = new TypeVariableType(variableElement);
variableElement.type = variableType;
arguments.addLast(variableType);
}
return arguments.toLink();
}
}
class ClassElement extends ScopeContainerElement
implements TypeDeclarationElement {
static final int STATE_NOT_STARTED = 0;
static final int STATE_STARTED = 1;
static final int STATE_DONE = 2;
final int id;
InterfaceType type;
Type supertype;
Type defaultClass;
Link<Type> interfaces;
SourceString nativeName;
int supertypeLoadState;
int resolutionState;
// backendMembers are members that have been added by the backend to simplify
// compilation. They don't have any user-side counter-part.
Link<Element> backendMembers = const EmptyLink<Element>();
Link<Type> allSupertypes;
// Lazily applied patch of class members.
ClassElement patch = null;
ClassElement(SourceString name, Element enclosing, this.id, int initialState)
: supertypeLoadState = initialState,
resolutionState = initialState,
super(name, ElementKind.CLASS, enclosing);
InterfaceType computeType(compiler) {
if (type == null) {
ClassNode node = parseNode(compiler);
Link<Type> parameters =
TypeDeclarationElement.createTypeVariables(this, node.typeParameters);
type = new InterfaceType(this, parameters);
}
return type;
}
bool get isPatched() => patch != null;
Link<Type> get typeVariables() => type.arguments;
ClassElement ensureResolved(Compiler compiler) {
if (resolutionState == STATE_NOT_STARTED) {
compiler.resolver.resolveClass(this);
}
return this;
}
/**
* Lookup local members in the class. This will ignore constructors.
*/
Element lookupLocalMember(SourceString memberName) {
var result = localLookup(memberName);
if (result !== null && result.isConstructor()) return null;
return result;
}
/**
* Lookup super members for the class. This will ignore constructors.
*/
Element lookupSuperMember(SourceString memberName) {
return lookupSuperMemberInLibrary(memberName, getLibrary());
}
/**
* Lookup super members for the class that is accessible in [library].
* This will ignore constructors.
*/
Element lookupSuperMemberInLibrary(SourceString memberName,
LibraryElement library) {
bool isPrivate = memberName.isPrivate();
for (ClassElement s = superclass; s != null; s = s.superclass) {
// Private members from a different library are not visible.
if (isPrivate && library !== s.getLibrary()) continue;
Element e = s.lookupLocalMember(memberName);
if (e === null) continue;
// Static members are not inherited.
if (e.modifiers.isStatic()) continue;
return e;
}
if (isInterface()) {
return lookupSuperInterfaceMember(memberName, getLibrary());
}
return null;
}
Element lookupSuperInterfaceMember(SourceString memberName,
LibraryElement fromLibrary) {
bool isPrivate = memberName.isPrivate();
for (InterfaceType t in interfaces) {
ClassElement cls = t.element;
Element e = cls.lookupLocalMember(memberName);
if (e === null) continue;
// Private members from a different library are not visible.
if (isPrivate && fromLibrary !== e.getLibrary()) continue;
// Static members are not inherited.
if (e.modifiers.isStatic()) continue;
return e;
}
return null;
}
/**
* Find the first member in the class chain with the given [selector].
*
* This method is NOT to be used for resolving
* unqualified sends because it does not implement the scoping
* rules, where library scope comes before superclass scope.
*/
Element lookupSelector(Selector selector) {
SourceString memberName = selector.name;
LibraryElement library = selector.library;
Element localMember = lookupLocalMember(memberName);
if (localMember != null &&
(!memberName.isPrivate() || getLibrary() == library)) {
return localMember;
}
return lookupSuperMemberInLibrary(memberName, library);
}
/**
* Find the first member in the class chain with the given
* [memberName]. This method is NOT to be used for resolving
* unqualified sends because it does not implement the scoping
* rules, where library scope comes before superclass scope.
*/
Element lookupMember(SourceString memberName) {
Element localMember = lookupLocalMember(memberName);
return localMember === null ? lookupSuperMember(memberName) : localMember;
}
/**
* Returns true if the [fieldMember] is shadowed by another field. The given
* [fieldMember] must be a member of this class.
*
* This method also works if the [fieldMember] is private.
*/
bool isShadowedByField(Element fieldMember) {
assert(fieldMember.isField());
// Note that we cannot use [lookupMember] or [lookupSuperMember] since it
// will not do the right thing for private elements.
ClassElement lookupClass = this;
LibraryElement memberLibrary = fieldMember.getLibrary();
if (fieldMember.name.isPrivate()) {
// We find a super class in the same library as the field. This way the
// lookupMember will work.
while (lookupClass.getLibrary() != memberLibrary) {
lookupClass = lookupClass.superclass;
}
}
SourceString fieldName = fieldMember.name;
while (true) {
Element foundMember = lookupClass.lookupMember(fieldName);
if (foundMember == fieldMember) return false;
if (foundMember.isField()) return true;
lookupClass = foundMember.getEnclosingClass().superclass;
}
}
Element lookupConstructor(SourceString className,
[SourceString constructorName =
const SourceString(''),
Element noMatch(Element)]) {
// TODO(karlklose): have a map from class names to a map of constructors
// instead of creating the name here?
SourceString normalizedName;
if (constructorName !== const SourceString('')) {
normalizedName = Elements.constructConstructorName(className,
constructorName);
} else {
normalizedName = className;
}
Element result = localLookup(normalizedName);
if (result === null || !result.isConstructor()) {
result = noMatch !== null ? noMatch(result) : null;
}
return result;
}
bool get hasConstructor() {
// Search in scope to be sure we search patched constructors.
for (var element in localScope.getValues()) {
if (element.isConstructor()) return true;
}
return false;
}
Link<Element> get constructors() {
// TODO(ajohnsen): See if we can avoid this method at some point.
Link<Element> result = const EmptyLink<Element>();
for (Element member in localMembers) {
if (member.isConstructor()) result = result.prepend(member);
}
return result;
}
/**
* Returns the super class, if any.
*
* The returned element may not be resolved yet.
*/
ClassElement get superclass() {
assert(supertypeLoadState == STATE_DONE);
return supertype === null ? null : supertype.element;
}
/**
* Runs through all members of this class.
*
* The enclosing class is passed to the callback. This is useful when
* [includeSuperMembers] is [:true:].
*/
void forEachMember([void f(ClassElement enclosingClass, Element member),
includeBackendMembers = false,
includeSuperMembers = false]) {
Set<ClassElement> seen = new Set<ClassElement>();
ClassElement classElement = this;
do {
if (seen.contains(classElement)) return;
seen.add(classElement);
for (Element element in classElement.localMembers) {
f(classElement, element);
}
if (includeBackendMembers) {
for (Element element in classElement.backendMembers) {
f(classElement, element);
}
}
classElement = includeSuperMembers ? classElement.superclass : null;
} while(classElement !== null);
}
/**
* Runs through all instance-field members of this class.
*
* The enclosing class is passed to the callback. This is useful when
* [includeSuperMembers] is [:true:].
*
* When [includeBackendMembers] and [includeSuperMembers] are both [:true:]
* then the fields are visited in the same order as they need to be given
* to the JavaScript constructor.
*/
void forEachInstanceField([void f(ClassElement enclosingClass, Element field),
includeBackendMembers = false,
includeSuperMembers = false]) {
// Filters so that [f] is only invoked with instance fields.
void fieldFilter(ClassElement enclosingClass, Element member) {
if (member.isInstanceMember() && member.kind == ElementKind.FIELD) {
f(enclosingClass, member);
}
}
forEachMember(fieldFilter, includeBackendMembers, includeSuperMembers);
}
bool implementsInterface(ClassElement intrface) {
for (Type implementedInterfaceType in allSupertypes) {
ClassElement implementedInterface = implementedInterfaceType.element;
if (implementedInterface === intrface) {
return true;
}
}
return false;
}
/**
* Returns true if [this] is a subclass of [cls].
*
* This method is not to be used for checking type hierarchy and
* assignments, because it does not take parameterized types into
* account.
*/
bool isSubclassOf(ClassElement cls) {
for (ClassElement s = this; s != null; s = s.superclass) {
if (s === cls) return true;
}
return false;
}
bool isInterface() => false;
bool isNative() => nativeName != null;
int hashCode() => id;
Scope buildScope() =>
new ClassScope(enclosingElement.buildScope(), this);
ClassElement cloneTo(Element enclosing, DiagnosticListener listener) {
listener.internalErrorOnElement(this, 'unsupported operation');
}
Link<Type> get allSupertypesAndSelf() {
return allSupertypes.prepend(new InterfaceType(this));
}
}
class Elements {
static bool isLocal(Element element) {
return !Element.isInvalid(element)
&& !element.isInstanceMember()
&& !isStaticOrTopLevelField(element)
&& !isStaticOrTopLevelFunction(element)
&& (element.kind === ElementKind.VARIABLE ||
element.kind === ElementKind.PARAMETER ||
element.kind === ElementKind.FUNCTION);
}
static bool isInstanceField(Element element) {
return !Element.isInvalid(element)
&& element.isInstanceMember()
&& (element.kind === ElementKind.FIELD
|| element.kind === ElementKind.GETTER
|| element.kind === ElementKind.SETTER);
}
static bool isStaticOrTopLevel(Element element) {
// TODO(ager): This should not be necessary when patch support has
// been reworked.
if (!Element.isInvalid(element)
&& element.modifiers != null
&& element.modifiers.isStatic()) {
return true;
}
return !Element.isInvalid(element)
&& !element.isInstanceMember()
&& !element.isPrefix()
&& element.enclosingElement !== null
&& (element.enclosingElement.kind == ElementKind.CLASS ||
element.enclosingElement.kind == ElementKind.COMPILATION_UNIT ||
element.enclosingElement.kind == ElementKind.LIBRARY);
}
static bool isStaticOrTopLevelField(Element element) {
return isStaticOrTopLevel(element)
&& (element.kind === ElementKind.FIELD
|| element.kind === ElementKind.GETTER
|| element.kind === ElementKind.SETTER);
}
static bool isStaticOrTopLevelFunction(Element element) {
return isStaticOrTopLevel(element)
&& (element.kind === ElementKind.FUNCTION);
}
static bool isInstanceMethod(Element element) {
return !Element.isInvalid(element)
&& element.isInstanceMember()
&& (element.kind === ElementKind.FUNCTION);
}
static bool isInstanceSend(Send send, TreeElements elements) {
Element element = elements[send];
if (element === null) return !isClosureSend(send, element);
return isInstanceMethod(element) || isInstanceField(element);
}
static bool isClosureSend(Send send, Element element) {
if (send.isPropertyAccess) return false;
if (send.receiver !== null) return false;
// (o)() or foo()().
if (element === null && send.selector.asIdentifier() === null) return true;
if (element === null) return false;
// foo() with foo a local or a parameter.
return isLocal(element);
}
static SourceString constructConstructorName(SourceString receiver,
SourceString selector) {
String r = receiver.slowToString();
String s = selector.slowToString();
return new SourceString('$r\$$s');
}
static final SourceString OPERATOR_EQUALS =
const SourceString(@'operator$eq');
static SourceString constructOperatorName(SourceString receiver,
SourceString selector,
[bool isUnary = false]) {
String str = selector.stringValue;
if (str === '==' || str === '!=') return OPERATOR_EQUALS;
if (str === '~') str = 'not';
else if (str === 'negate' || (str === '-' && isUnary)) str = 'negate';
else if (str === '[]') str = 'index';
else if (str === '[]=') str = 'indexSet';
else if (str === '*' || str === '*=') str = 'mul';
else if (str === '/' || str === '/=') str = 'div';
else if (str === '%' || str === '%=') str = 'mod';
else if (str === '~/' || str === '~/=') str = 'tdiv';
else if (str === '+' || str === '+=') str = 'add';
else if (str === '-' || str === '-=') str = 'sub';
else if (str === '<<' || str === '<<=') str = 'shl';
else if (str === '>>' || str === '>>=') str = 'shr';
else if (str === '>=') str = 'ge';
else if (str === '>') str = 'gt';
else if (str === '<=') str = 'le';
else if (str === '<') str = 'lt';
else if (str === '&' || str === '&=') str = 'and';
else if (str === '^' || str === '^=') str = 'xor';
else if (str === '|' || str === '|=') str = 'or';
else {
throw new Exception('Unhandled selector: ${selector.slowToString()}');
}
return new SourceString('$receiver\$$str');
}
static bool isStringSupertype(Element element, Compiler compiler) {
LibraryElement coreLibrary = compiler.coreLibrary;
return (element == coreLibrary.find(const SourceString('Comparable')))
|| (element == coreLibrary.find(const SourceString('Hashable')))
|| (element == coreLibrary.find(const SourceString('Pattern')));
}
static bool isListSupertype(Element element, Compiler compiler) {
LibraryElement coreLibrary = compiler.coreLibrary;
return (element == coreLibrary.find(const SourceString('Collection')))
|| (element == coreLibrary.find(const SourceString('Iterable')));
}
}
class LabelElement extends Element {
// We store the original label here so it can be returned by [parseNode].
final Label label;
final String labelName;
final TargetElement target;
bool isBreakTarget = false;
bool isContinueTarget = false;
LabelElement(Label label, this.labelName, this.target,
Element enclosingElement)
: this.label = label,
super(label.identifier.source, ElementKind.LABEL, enclosingElement);
void setBreakTarget() {
isBreakTarget = true;
target.isBreakTarget = true;
}
void setContinueTarget() {
isContinueTarget = true;
target.isContinueTarget = true;
}
bool get isTarget() => isBreakTarget || isContinueTarget;
Node parseNode(DiagnosticListener l) => label;
Token position() => label.getBeginToken();
String toString() => "${labelName}:";
}
// Represents a reference to a statement or switch-case, either by label or the
// default target of a break or continue.
class TargetElement extends Element {
final Node statement;
final int nestingLevel;
Link<LabelElement> labels = const EmptyLink<LabelElement>();
bool isBreakTarget = false;
bool isContinueTarget = false;
TargetElement(this.statement, this.nestingLevel, Element enclosingElement)
: super(const SourceString(""), ElementKind.STATEMENT, enclosingElement);
bool get isTarget() => isBreakTarget || isContinueTarget;
LabelElement addLabel(Label label, String labelName) {
LabelElement result = new LabelElement(label, labelName, this,
enclosingElement);
labels = labels.prepend(result);
return result;
}
Node parseNode(DiagnosticListener l) => statement;
bool get isSwitch() => statement is SwitchStatement;
Token position() => statement.getBeginToken();
String toString() => statement.toString();
}
class TypeVariableElement extends Element {
final Node cachedNode;
TypeVariableType type;
Type bound;
TypeVariableElement(name, Element enclosing, this.cachedNode,
[this.type, this.bound])
: super(name, ElementKind.TYPE_VARIABLE, enclosing);
TypeVariableType computeType(compiler) => type;
Node parseNode(compiler) => cachedNode;
String toString() => "${enclosingElement.toString()}.${name.slowToString()}";
Token position() => cachedNode.getBeginToken();
TypeVariableElement cloneTo(Element enclosing, DiagnosticListener listener) {
TypeVariableElement result =
new TypeVariableElement(name, enclosing, cachedNode, type, bound);
return result;
}
}