Revert "Delete support for source mirrors"

pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart

Index: pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
diff --git a/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart b/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0e64cc3d1ee9c3d7d13acd3ebb656f6eae74de37
--- /dev/null
+++ b/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
@@ -0,0 +1,490 @@
+// 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 dart2js.mirrors;
+
+import 'dart:collection' show UnmodifiableListView, UnmodifiableMapView;
+
+import '../common.dart';
+import '../compiler.dart' show
+    Compiler;
+import '../constants/expressions.dart';
+import '../constants/values.dart';
+import '../dart_types.dart';
+import '../elements/elements.dart';
+import '../elements/modelx.dart' show
+    LibraryElementX;
+import '../resolution/scope.dart' show
+    Scope;
+import '../script.dart';
+import '../tokens/token.dart';
+import '../tokens/token_constants.dart' as Tokens;
+import '../tree/tree.dart';
+import '../util/util.dart'
+    show Link,
+         LinkBuilder;
+import '../util/characters.dart' show $CR, $LF;
+
+import 'source_mirrors.dart';
+import 'mirrors_util.dart';
+
+part 'dart2js_library_mirror.dart';
+part 'dart2js_type_mirrors.dart';
+part 'dart2js_member_mirrors.dart';
+part 'dart2js_instance_mirrors.dart';
+
+//------------------------------------------------------------------------------
+// Utility types and functions for the dart2js mirror system
+//------------------------------------------------------------------------------
+
+bool _includeLibrary(Dart2JsLibraryMirror mirror) {
+  return const bool.fromEnvironment("list_all_libraries") ||
+      !mirror._element.isInternalLibrary;
+}
+
+bool _isPrivate(String name) {
+  return name.startsWith('_');
+}
+
+List<ParameterMirror> _parametersFromFunctionSignature(
+    Dart2JsDeclarationMirror owner,
+    FunctionSignature signature) {
+  var parameters = <ParameterMirror>[];
+  signature.requiredParameters.forEach((FormalElement parameter) {
+    parameters.add(new Dart2JsParameterMirror(
+        owner, parameter, isOptional: false, isNamed: false));
+  });
+  bool isNamed = signature.optionalParametersAreNamed;
+  signature.optionalParameters.forEach((FormalElement parameter) {
+    parameters.add(new Dart2JsParameterMirror(
+        owner, parameter, isOptional: true, isNamed: isNamed));
+  });
+  return parameters;
+}
+
+MethodMirror _convertElementMethodToMethodMirror(
+    Dart2JsDeclarationMirror library, Element element) {
+  if (element is FunctionElement) {
+    return new Dart2JsMethodMirror(library, element);
+  } else {
+    return null;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Dart2Js specific extensions of mirror interfaces
+//------------------------------------------------------------------------------
+
+abstract class Dart2JsMirror implements Mirror {
+  Dart2JsMirrorSystem get mirrorSystem;
+}
+
+abstract class Dart2JsDeclarationMirror extends Dart2JsMirror
+    implements DeclarationSourceMirror {
+
+  bool get isTopLevel => owner != null && owner is LibraryMirror;
+
+  bool get isPrivate => _isPrivate(_simpleNameString);
+
+  String get _simpleNameString;
+
+  String get _qualifiedNameString {
+    var parent = owner;
+    if (parent is Dart2JsDeclarationMirror) {
+      return '${parent._qualifiedNameString}.${_simpleNameString}';
+    }
+    assert(parent == null);
+    return _simpleNameString;
+  }
+
+  Symbol get simpleName => symbolOf(_simpleNameString, getLibrary(this));
+
+  Symbol get qualifiedName => symbolOf(_qualifiedNameString, getLibrary(this));
+
+  DeclarationMirror lookupInScope(String name) => null;
+
+  bool get isNameSynthetic => false;
+
+  /// Returns the type mirror for [type] in the context of this declaration.
+  TypeMirror _getTypeMirror(DartType type) {
+    return mirrorSystem._convertTypeToTypeMirror(type);
+  }
+
+  /// Returns a list of the declaration mirrorSystem for [element].
+  Iterable<Dart2JsMemberMirror> _getDeclarationMirrors(Element element) {
+    if (element.isSynthesized) {
+      return const <Dart2JsMemberMirror>[];
+    } else if (element is VariableElement) {
+      return <Dart2JsMemberMirror>[new Dart2JsFieldMirror(this, element)];
+    } else if (element is FunctionElement) {
+      return <Dart2JsMemberMirror>[new Dart2JsMethodMirror(this, element)];
+    } else if (element is AbstractFieldElement) {
+      var members = <Dart2JsMemberMirror>[];
+      AbstractFieldElement field = element;
+      if (field.getter != null) {
+        members.add(new Dart2JsMethodMirror(this, field.getter));
+      }
+      if (field.setter != null) {
+        members.add(new Dart2JsMethodMirror(this, field.setter));
+      }
+      return members;
+    }
+    mirrorSystem.compiler.reporter.internalError(element,
+        "Unexpected member type $element ${element.kind}.");
+    return null;
+  }
+}
+
+abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
+  final Dart2JsMirrorSystem mirrorSystem;
+  final Element _element;
+  List<InstanceMirror> _metadata;
+
+  Dart2JsElementMirror(this.mirrorSystem, this._element) {
+    assert (mirrorSystem != null);
+    assert (_element != null);
+  }
+
+  String get _simpleNameString => _element.name;
+
+  /**
+   * Computes the first token for this declaration using the begin token of the
+   * element node or element position as indicator.
+   */
+  Token getBeginToken() {
+    Element element = _element;
+    if (element is AstElement) {
+      Node node = element.node;
+      if (node != null) {
+        return node.getBeginToken();
+      }
+    }
+    return element.position;
+  }
+
+  /**
+   * Computes the last token for this declaration using the end token of the
+   * element node or element position as indicator.
+   */
+  Token getEndToken() {
+    Element element = _element;
+    if (element is AstElement) {
+      Node node = element.node;
+      if (node != null) {
+        return node.getEndToken();
+      }
+    }
+    return element.position;
+  }
+
+  /**
+   * Returns the first token for the source of this declaration, including
+   * metadata annotations.
+   */
+  Token getFirstToken() {
+    if (!_element.metadata.isEmpty) {
+      for (MetadataAnnotation metadata in _element.metadata) {
+        if (metadata.beginToken != null) {
+          return metadata.beginToken;
+        }
+      }
+    }
+    return getBeginToken();
+  }
+
+  Script getScript() => _element.compilationUnit.script;
+
+  SourceLocation get location {
+    Token beginToken = getFirstToken();
+    Script script = getScript();
+    SourceSpan span;
+    if (beginToken == null) {
+      span = new SourceSpan(script.resourceUri, 0, 0);
+    } else {
+      Token endToken = getEndToken();
+      span = new SourceSpan.fromTokens(
+          script.resourceUri, beginToken, endToken);
+    }
+    return new Dart2JsSourceLocation(script, span);
+  }
+
+  String toString() => _element.toString();
+
+  void _appendCommentTokens(Token commentToken) {
+    while (commentToken != null && commentToken.kind == Tokens.COMMENT_TOKEN) {
+      _metadata.add(new Dart2JsCommentInstanceMirror(
+          mirrorSystem, commentToken.value));
+      commentToken = commentToken.next;
+    }
+  }
+
+  List<InstanceMirror> get metadata {
+    if (_metadata == null) {
+      _metadata = <InstanceMirror>[];
+      for (MetadataAnnotation metadata in _element.metadata) {
+        _appendCommentTokens(
+            mirrorSystem.compiler.commentMap[metadata.beginToken]);
+        metadata.ensureResolved(mirrorSystem.compiler.resolution);
+        _metadata.add(_convertConstantToInstanceMirror(
+            mirrorSystem, metadata.constant,
+            mirrorSystem.compiler.constants.getConstantValue(
+                metadata.constant)));
+      }
+      _appendCommentTokens(mirrorSystem.compiler.commentMap[getBeginToken()]);
+    }
+    // TODO(johnniwinther): Return an unmodifiable list instead.
+    return new List<InstanceMirror>.from(_metadata);
+  }
+
+  DeclarationMirror lookupInScope(String name) {
+    // TODO(11653): Support lookup of constructors.
+    Scope scope = _element.buildScope();
+    Element result;
+    int index = name.indexOf('.');
+    if (index != -1) {
+      // Lookup [: prefix.id :].
+      String prefix = name.substring(0, index);
+      String id = name.substring(index+1);
+      result = scope.lookup(prefix);
+      if (result != null && result.isPrefix) {
+        PrefixElement prefix = result;
+        result = prefix.lookupLocalMember(id);
+      } else {
+        result = null;
+      }
+    } else {
+      // Lookup [: id :].
+      result = scope.lookup(name);
+    }
+    if (result == null || result.isPrefix) return null;
+    return _convertElementToDeclarationMirror(mirrorSystem, result);
+  }
+
+  bool operator ==(var other) {
+    if (identical(this, other)) return true;
+    if (other == null) return false;
+    if (other is! Dart2JsElementMirror) return false;
+    return _element == other._element &&
+           owner == other.owner;
+  }
+
+  int get hashCode {
+    return 13 * _element.hashCode + 17 * owner.hashCode;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Mirror system implementation.
+//------------------------------------------------------------------------------
+
+class Dart2JsMirrorSystem extends MirrorSystem {
+  final Compiler compiler;
+  Map<LibraryElement, Dart2JsLibraryMirror> _libraryMap;
+  UnmodifiableMapView<Uri, LibraryMirror> _filteredLibraries;
+
+  Dart2JsMirrorSystem(this.compiler);
+
+  IsolateMirror get isolate => null;
+
+  void _ensureLibraries() {
+    if (_filteredLibraries == null) {
+      var filteredLibs = new Map<Uri, LibraryMirror>();
+      _libraryMap = new Map<LibraryElement, Dart2JsLibraryMirror>();
+      compiler.libraryLoader.libraries.forEach((LibraryElement v) {
+        var mirror = new Dart2JsLibraryMirror(mirrorSystem, v);
+        if (_includeLibrary(mirror)) {
+          filteredLibs[mirror.uri] = mirror;
+        }
+        _libraryMap[v] = mirror;
+      });
+
+      _filteredLibraries =
+          new UnmodifiableMapView<Uri, LibraryMirror>(filteredLibs);
+    }
+  }
+
+  Map<Uri, LibraryMirror> get libraries {
+    _ensureLibraries();
+    return _filteredLibraries;
+  }
+
+  Dart2JsLibraryMirror _getLibrary(LibraryElement element) =>
+      _libraryMap[element];
+
+  Dart2JsMirrorSystem get mirrorSystem => this;
+
+  TypeMirror get dynamicType =>
+      _convertTypeToTypeMirror(const DynamicType());
+
+  TypeMirror get voidType =>
+      _convertTypeToTypeMirror(const VoidType());
+
+  TypeMirror _convertTypeToTypeMirror(DartType type) {
+    assert(type != null);
+    if (type.treatAsDynamic) {
+      return new Dart2JsDynamicMirror(this, type);
+    } else if (type is InterfaceType) {
+      if (type.typeArguments.isEmpty) {
+        return _getTypeDeclarationMirror(type.element);
+      } else {
+        return new Dart2JsInterfaceTypeMirror(this, type);
+      }
+    } else if (type is TypeVariableType) {
+      return new Dart2JsTypeVariableMirror(this, type);
+    } else if (type is FunctionType) {
+      return new Dart2JsFunctionTypeMirror(this, type);
+    } else if (type is VoidType) {
+      return new Dart2JsVoidMirror(this, type);
+    } else if (type is TypedefType) {
+      if (type.typeArguments.isEmpty) {
+        return _getTypeDeclarationMirror(type.element);
+      } else {
+        return new Dart2JsTypedefMirror(this, type);
+      }
+    }
+    compiler.reporter.internalError(type.element,
+        "Unexpected type $type of kind ${type.kind}.");
+    return null;
+  }
+
+  DeclarationMirror _getTypeDeclarationMirror(TypeDeclarationElement element) {
+    if (element.isClass) {
+      return new Dart2JsClassDeclarationMirror(this, element.thisType);
+    } else if (element.isTypedef) {
+      return new Dart2JsTypedefDeclarationMirror(this, element.thisType);
+    }
+    compiler.reporter.internalError(element, "Unexpected element $element.");
+    return null;
+  }
+}
+
+abstract class ContainerMixin {
+  UnmodifiableMapView<Symbol, DeclarationMirror> _declarations;
+
+  void _ensureDeclarations() {
+    if (_declarations == null) {
+      var declarations = <Symbol, DeclarationMirror>{};
+      _forEachElement((Element element) {
+        for (DeclarationMirror mirror in _getDeclarationMirrors(element)) {
+          assert(invariant(_element,
+              !declarations.containsKey(mirror.simpleName),
+              message: "Declaration name '${nameOf(mirror)}' "
+                       "is not unique in $_element."));
+          declarations[mirror.simpleName] = mirror;
+        }
+      });
+      _declarations =
+          new UnmodifiableMapView<Symbol, DeclarationMirror>(declarations);
+    }
+  }
+
+  Element get _element;
+
+  void _forEachElement(f(Element element));
+
+  Iterable<Dart2JsMemberMirror> _getDeclarationMirrors(Element element);
+
+  Map<Symbol, DeclarationMirror> get declarations {
+    _ensureDeclarations();
+    return _declarations;
+  }
+}
+
+/**
+ * Converts [element] into its corresponding [DeclarationMirror], if any.
+ *
+ * If [element] is an [AbstractFieldElement] the mirror for its getter is
+ * returned or, if not present, the mirror for its setter.
+ */
+DeclarationMirror _convertElementToDeclarationMirror(Dart2JsMirrorSystem system,
+                                                     Element element) {
+  if (element.isTypeVariable) {
+    TypeVariableElement typeVariable = element;
+    return new Dart2JsTypeVariableMirror(system, typeVariable.type);
+  }
+
+  Dart2JsLibraryMirror library = system._libraryMap[element.library];
+  if (element.isLibrary) return library;
+  if (element.isTypedef) {
+    TypedefElement typedefElement = element;
+    return new Dart2JsTypedefMirror.fromLibrary(
+        library, typedefElement.thisType);
+  }
+
+  Dart2JsDeclarationMirror container = library;
+  if (element.enclosingClass != null) {
+    container = system._getTypeDeclarationMirror(element.enclosingClass);
+  }
+  if (element.isClass) return container;
+  if (element.isParameter) {
+    Dart2JsMethodMirror method = _convertElementMethodToMethodMirror(
+        container, element.outermostEnclosingMemberOrTopLevel);
+    // TODO(johnniwinther): Find the right info for [isOptional] and [isNamed].
+    return new Dart2JsParameterMirror(
+        method, element, isOptional: false, isNamed: false);
+  }
+  Iterable<DeclarationMirror> members =
+      container._getDeclarationMirrors(element);
+  if (members.isEmpty) return null;
+  return members.first;
+}
+
+/**
+ * Experimental API for accessing compilation units defined in a
+ * library.
+ */
+// TODO(ahe): Superclasses? Is this really a mirror?
+class Dart2JsCompilationUnitMirror extends Dart2JsMirror with ContainerMixin {
+  final Dart2JsLibraryMirror _library;
+  final CompilationUnitElement _element;
+
+  Dart2JsCompilationUnitMirror(this._element, this._library);
+
+  Dart2JsMirrorSystem get mirrorSystem => _library.mirrorSystem;
+
+  // TODO(johnniwinther): make sure that these are returned in declaration
+  // order.
+  void _forEachElement(f(Element element)) => _element.forEachLocalMember(f);
+
+  Iterable<DeclarationMirror> _getDeclarationMirrors(Element element) =>
+      _library._getDeclarationMirrors(element);
+
+  Uri get uri => _element.script.resourceUri;
+}
+
+/**
+ * Transitional class that allows access to features that have not yet
+ * made it to the mirror API.
+ *
+ * All API in this class is experimental.
+ */
+class BackDoor {
+  /// Return the compilation units comprising [library].
+  static List<Mirror> compilationUnitsOf(Dart2JsLibraryMirror library) {
+    return library._element.compilationUnits.mapToList(
+        (cu) => new Dart2JsCompilationUnitMirror(cu, library));
+  }
+
+  static Iterable<ConstantExpression> metadataSyntaxOf(
+      Dart2JsElementMirror declaration) {
+    return declaration._element.metadata.map((metadata) => metadata.constant);
+  }
+
+  static ConstantExpression initializerSyntaxOf(Dart2JsFieldMirror variable) {
+    Compiler compiler = variable.mirrorSystem.compiler;
+    return compiler.constants.getConstantForVariable(variable._variable);
+  }
+
+  static ConstantExpression defaultValueSyntaxOf(
+        Dart2JsParameterMirror parameter) {
+    if (!parameter.hasDefaultValue) return null;
+    ParameterElement parameterElement = parameter._element;
+    Compiler compiler = parameter.mirrorSystem.compiler;
+    return compiler.constants.getConstantForVariable(parameterElement);
+  }
+
+  static Mirror getMirrorFromElement(Dart2JsMirror mirror, Element element) {
+    return _convertElementToDeclarationMirror(mirror.mirrorSystem, element);
+  }
+}