Add lookupInScope to DeclarationMirror.

sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart

Index: sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
diff --git a/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart b/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
index 14934380c2eefe897c3adf54387cb698f95c116d..d90fcf018050b0e335b9c59ca6e75ba272f869c7 100644
--- a/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
+++ b/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
@@ -11,6 +11,7 @@ import '../../compiler.dart' as api;
 import '../elements/elements.dart';
 import '../apiimpl.dart' as apiimpl;
 import '../scanner/scannerlib.dart' hide SourceString;
+import '../resolution/resolution.dart' show Scope;
 import '../dart2jslib.dart';
 import '../dart_types.dart';
 import '../source_file.dart';
@@ -38,14 +39,14 @@ List<ParameterMirror> _parametersFromFunctionSignature(
   Link<Element> link = signature.requiredParameters;
   while (!link.isEmpty) {
     parameters.add(new Dart2JsParameterMirror(
-        system, method, link.head, false, false));
+        system, method, link.head, isOptional: false, isNamed: false));
     link = link.tail;
   }
   link = signature.optionalParameters;
   bool isNamed = signature.optionalParametersAreNamed;
   while (!link.isEmpty) {
     parameters.add(new Dart2JsParameterMirror(
-        system, method, link.head, true, isNamed));
+        system, method, link.head, isOptional: true, isNamed: isNamed));
     link = link.tail;
   }
   return parameters;
@@ -348,8 +349,6 @@ abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
 
   String toString() => _element.toString();
 
-  int get hashCode => qualifiedName.hashCode;
-
   void _appendCommentTokens(Token commentToken) {
     while (commentToken != null && commentToken.kind == COMMENT_TOKEN) {
       _metadata.add(new Dart2JsCommentInstanceMirror(
@@ -372,6 +371,42 @@ abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
     // TODO(johnniwinther): Return an unmodifiable list instead.
     return new List<InstanceMirror>.from(_metadata);
   }
+
+  DeclarationMirror lookupInScope(String name) {

[Andrei Mouravski, 2013/07/03 17:49:49]

This should have a doccomment, especially since it might be ambiguous which
String to give it. Like, do you pass in "[:foo.bar:]" or "foo.bar".

[Johnni Winther, 2013/07/04 13:11:47]

Updated the doccomment on the declaration.

+    // TODO(11653): Support lookup of constructors.
+    Scope scope = _element.buildScope();
+    Element result;
+    int index = name.indexOf('.');
+    if (index != -1) {

[Andrei Mouravski, 2013/07/03 17:49:49]

This code got a lot more complicated. Let me see if I can parse it:

// if theres no '.'
//   then look up id in current scope.
// if there's something that looks like a prefix (what happens with "library
com.google.foo"?)
//   then lookup the element given by that prefix.
//   if it is a Prefix, 
//     then return the member given by the postfix

It seems odd that this works. What does it do on library names like
"com.google.foo"?

I just feel like the nesting of the ifs is really hard to read or decipher.

Maybe:

... lookupInScope(String name) {
  Element getSourceString(String name) {
    if (name.contains('.')) new SourceString(name.substring(0, index));
    return new SourceString(name);
  }

  Element result = getSourceString(name);

  if (result != null && result.isPrefix()) {
    result = result.lookupLocalMember(
      new SourceString(name.substring(name.indexOf('.') + 1)))
  }

  if (result == null || result.isPrefix()) return null;
  return _convertElement...'
} 

[Johnni Winther, 2013/07/04 13:11:47]

Lookup of libraries is not supported. They are not only ambiguous but also not
in scope. 

The reason why the method is so complicated is a that we have to handle prefixes
since are not part of the mirror system and therefore cannot be returned
directly.

The split with the getSourceString method doesn't work since it will allow us to
lookup [: prefix.prefix :] by 'prefix'. For instance lookup the [:Future:] class
through 'Future' when import like

import 'dart:async' as Future;

+      // Lookup [: prefix.id :].
+      String prefix = name.substring(0, index);
+      String id = name.substring(index+1);
+      result = scope.lookup(new SourceString(prefix)); 
+      if (result != null && result.isPrefix()) {
+        PrefixElement prefix = result;
+        result = prefix.lookupLocalMember(new SourceString(id));
+      } else {
+        result = null;
+      }
+    } else {
+      // Lookup [: id :].
+      result = scope.lookup(new SourceString(name));
+    }
+    if (result == null || result.isPrefix()) return null;
+    return _convertElementToDeclarationMirror(mirrors, 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;
+  }
 }
 
 abstract class Dart2JsMemberMirror extends Dart2JsElementMirror
@@ -665,8 +700,8 @@ class Dart2JsParameterMirror extends Dart2JsMemberMirror
   factory Dart2JsParameterMirror(Dart2JsMirrorSystem system,
                                  MethodMirror method,
                                  VariableElement element,
-                                 bool isOptional,
-                                 bool isNamed) {
+                                 {bool isOptional: false,
+                                  bool isNamed: false}) {
     if (element is FieldParameterElement) {
       return new Dart2JsFieldParameterMirror(system,
           method, element, isOptional, isNamed);
@@ -1385,6 +1420,15 @@ class Dart2JsMethodMirror extends Dart2JsMemberMirror
   bool get isSetter => _kind == Dart2JsMethodKind.SETTER;
 
   bool get isOperator => _kind == Dart2JsMethodKind.OPERATOR;
+
+  DeclarationMirror lookupInScope(String name) {
+    for (ParameterMirror parameter in parameters) {
+      if (parameter.simpleName == name) {
+        return parameter;
+      }
+    }
+    return super.lookupInScope(name);
+  }
 }
 
 class Dart2JsFieldMirror extends Dart2JsMemberMirror implements VariableMirror {
@@ -1656,6 +1700,45 @@ _convertElementToMembers(Dart2JsLibraryMirror library, Element e) {
 }
 
 /**
+ * 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()) {
+    return new Dart2JsTypeVariableMirror(
+        system, element.computeType(system.compiler));
+  }
+
+  Dart2JsLibraryMirror library = system._libraryMap[element.getLibrary()];
+  if (element.isLibrary()) return library;
+  if (element.isTypedef()) {
+    return new Dart2JsTypedefMirror.fromLibrary(
+        library, element.computeType(system.compiler));
+  }
+
+  Dart2JsContainerMirror container = library;
+  if (element.getEnclosingClass() != null) {
+    container = new Dart2JsClassMirror.fromLibrary(
+        library, element.getEnclosingClass());
+  }
+  if (element.isClass()) return container;
+  if (element.isParameter()) {
+    MethodMirror method = _convertElementMethodToMethodMirror(
+        container, element.getOutermostEnclosingMemberOrTopLevel());
+    // TODO(johnniwinther): Find the right info for [isOptional] and [isNamed].
+    return new Dart2JsParameterMirror(
+        system, method, element, isOptional: false, isNamed: false);
+  }
+  Iterable<MemberMirror> members =
+      _convertElementMemberToMemberMirrors(container, element);
+  if (members.isEmpty) return null;
+  return members.first;
+}
+
+/**
  * Experimental API for accessing compilation units defined in a
  * library.
  */