Compute better names for source maps.

pkg/compiler/lib/src/io/source_information.dart

 // Copyright (c) 2015, 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.source_information;
 
 import '../dart2jslib.dart' show SourceSpan, MessageKind;
-import '../elements/elements.dart' show AstElement;
+import '../elements/elements.dart' show
+    AstElement,
+    LocalElement;
 import '../scanner/scannerlib.dart' show Token;
 import '../tree/tree.dart' show Node;
 import '../js/js.dart' show JavaScriptNodeSourceInformation;
 import 'source_file.dart';
 
 /// Interface for passing source information, for instance for use in source
 /// maps, through the backend.
 abstract class SourceInformation extends JavaScriptNodeSourceInformation {
   SourceSpan get sourceSpan;
 
@@ skipping 77 matching lines @@
            endPosition == other.endPosition;
   }
 
   // TODO(johnniwinther): Remove this method. Source information should be
   // computed based on the element by provided from statements and expressions.
   static StartEndSourceInformation computeSourceInformation(
       AstElement element) {
 
     AstElement implementation = element.implementation;
     SourceFile sourceFile = implementation.compilationUnit.script.file;
-    String name = element.name;
+    String name = computeElementNameForSourceMaps(element);
     Node node = implementation.node;
     Token beginToken;
     Token endToken;
     if (node == null) {
       // Synthesized node. Use the enclosing element for the location.
       beginToken = endToken = element.position;
     } else {
       beginToken = node.getBeginToken();
       endToken = node.getEndToken();
     }
@@ skipping 32 matching lines @@
   }
 }
 
 /// [SourceInformationBuilder] that generates [PositionSourceInformation].
 class StartEndSourceInformationBuilder extends SourceInformationBuilder {
   final SourceFile sourceFile;
   final String name;
 
   StartEndSourceInformationBuilder(AstElement element)
       : sourceFile = element.compilationUnit.script.file,
-        name = element.name;
+        name = computeElementNameForSourceMaps(element);
 
   SourceInformation buildDeclaration(AstElement element) {
     return StartEndSourceInformation.computeSourceInformation(element);
   }
 
   SourceLocation sourceFileLocationForToken(Token token) {
     SourceLocation location =
         new OffsetSourceLocation(sourceFile, token.charOffset, name);
     checkValidSourceFileLocation(location, sourceFile, token.charOffset);
     return location;
@@ skipping 162 matching lines @@
   }
 }
 
 /// [SourceInformationBuilder] that generates [PositionSourceInformation].
 class PositionSourceInformationBuilder implements SourceInformationBuilder {
   final SourceFile sourceFile;
   final String name;
 
   PositionSourceInformationBuilder(AstElement element)
       : sourceFile = element.implementation.compilationUnit.script.file,
-        name = element.name;
+        name = computeElementNameForSourceMaps(element);
 
   SourceInformation buildDeclaration(AstElement element) {
     if (element.isSynthesized) {
       return new PositionSourceInformation(
           new OffsetSourceLocation(
               sourceFile, element.position.charOffset, name));
     } else {
       return new PositionSourceInformation(
           null,
           new OffsetSourceLocation(sourceFile,
@@ skipping 19 matching lines @@
   SourceInformation buildGet(Node node) => buildBegin(node);
 
   @override
   SourceInformation buildCall(Node node) => buildBegin(node);
 
   @override
   SourceInformationBuilder forContext(AstElement element) {
     return new PositionSourceInformationBuilder(element);
   }
 }
+
+/// Compute the source map name for [element].
+String computeElementNameForSourceMaps(AstElement element) {
+  if (element.isClosure) {
+    return computeElementNameForSourceMaps(element.enclosingElement);
+  } else if (element.isClass) {
+    return element.name;
+  } else if (element.isConstructor || element.isGenerativeConstructorBody) {
+    String className = element.enclosingClass.name;
+    if (element.name == '') {
+      return className;
+    }
+    return '$className.${element.name}';
+  } else if (element.isLocal) {
+    LocalElement local = element;
+    String name = local.name;
+    if (name == '') {
+      name = '<anonymous function>';
+    }
+    return '${computeElementNameForSourceMaps(local.executableContext)}.$name';
+  } else if (element.enclosingClass != null) {
+    if (element.enclosingClass.isClosure) {
+      return computeElementNameForSourceMaps(element.enclosingClass);
+    }
+    return '${element.enclosingClass.name}.${element.name}';
+  } else {
+    return element.name;
+  }
+}