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

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

Index: pkg/analyzer/lib/src/generated/source_io.dart
diff --git a/pkg/analyzer/lib/src/generated/source_io.dart b/pkg/analyzer/lib/src/generated/source_io.dart
index 43dfb42947a6e0977e916b053dddcd9cda5b57b6..7a90a2a595b7a1bea9b2333477b49927d820eda4 100644
--- a/pkg/analyzer/lib/src/generated/source_io.dart
+++ b/pkg/analyzer/lib/src/generated/source_io.dart
@@ -11,6 +11,7 @@ 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';
 
@@ -146,6 +147,8 @@ class FileBasedSource extends Source {
    */
   static final Map<String, int> _idTable = new HashMap<String, int>();
 
+  source_span.SourceFile _sourceFile;
+
   /**
    * The URI from which this source was originally derived.
    */
@@ -235,6 +238,10 @@ class FileBasedSource extends Source {
   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);