Connect analyzer's AnalysisError object to front_end's CompilationError.

pkg/analyzer/lib/src/generated/source_io.dart

 // Copyright (c) 2014, 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 analyzer.src.generated.source_io;
 
 import 'dart:collection';
 
 import 'package:analyzer/exception/exception.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:path/path.dart' as path;
+import 'package:source_span/source_span.dart' as source_span;
 
 export 'package:analyzer/src/generated/source.dart';
 
 /**
  * Instances of the class [DirectoryBasedSourceContainer] represent a source container that
  * contains all sources within a given directory.
  */
 @deprecated
 class DirectoryBasedSourceContainer implements SourceContainer {
   /**
@@ skipping 115 matching lines @@
 
   /**
    * Map from encoded URI/filepath pair to a unique integer identifier.  This
    * identifier is used for equality tests and hash codes.
    *
    * The URI and filepath are joined into a pair by separating them with an '@'
    * character.
    */
   static final Map<String, int> _idTable = new HashMap<String, int>();
 
+  source_span.SourceFile _sourceFile;
+
   /**
    * The URI from which this source was originally derived.
    */
   @override
   final Uri uri;
 
   /**
    * The unique ID associated with this [FileBasedSource].
    */
   final int id;
@@ skipping 69 matching lines @@
   @override
   bool get isInSystemLibrary => uri.scheme == DartUriResolver.DART_SCHEME;
 
   @override
   int get modificationStamp => file.lastModified();
 
   @override
   String get shortName => file.getName();
 
   @override
+  source_span.SourceFile get sourceFile => _sourceFile ??=
+      new source_span.SourceFile(file.readAsStringSync(), url: uri);

[Brian Wilkerson, 2016/11/14 23:34:41]

I haven't thought this through completely, but this (and similar code in
FileSource) is somewhat concerning.
(1) If the content has been overlaid, then this could return a SourceFile with
the wrong content.
(2) Because sources are light-weight objects, we might end up reading the file
multiple times, even though it's cached in one source object.
(3) Because it's cached, it won't be recreated if the content changes (either on
disk or as an overlay).

+
+  @override
   UriKind get uriKind {
     String scheme = uri.scheme;
     return UriKind.fromScheme(scheme);
   }
 
   @override
   bool operator ==(Object object) {
     if (object is FileBasedSource) {
       return id == object.id;
     } else if (object is Source) {
@@ skipping 320 matching lines @@
   }
 
   /**
    * Return `true` if the given URI is a `file` URI.
    *
    * @param uri the URI being tested
    * @return `true` if the given URI is a `file` URI
    */
   static bool isFileUri(Uri uri) => uri.scheme == FILE_SCHEME;
 }