Refactor SourceFile, SourceFileProvider and SourceLocation.

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

 // 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.io.source_file;
 
 import 'dart:math';
 import 'dart:convert' show UTF8;
 
 import 'line_column_provider.dart';
 
 /**
  * Represents a file of source code. The content can be either a [String] or
  * a UTF-8 encoded [List<int>] of bytes.
  */
 abstract class SourceFile implements LineColumnProvider {
+  /// The absolute URI of the source file.
+  Uri get uri;
 
-  /** The name of the file. */
-  String get filename;
+  /// The name of the file.
+  ///
+  /// This is [uri], maybe relativized to a more human-readable form.
+  String get filename => uri.toString();
 
   /** The text content of the file represented as a String. */
   String slowText();
 
   /** The content of the file represented as a UTF-8 encoded [List<int>]. */
   List<int> slowUtf8Bytes();
 
   /**
    * The length of the string representation of this source file, i.e.,
    * equivalent to [:slowText().length:], but faster.
@@ skipping 128 matching lines @@
       for (; i < toColumn; i++) {
         buf.write(colorize('^'));
       }
     }
 
     return buf.toString();
   }
 }
 
 class Utf8BytesSourceFile extends SourceFile {
-  final String filename;
+  final Uri uri;
 
   /** The UTF-8 encoded content of the source file. */
   final List<int> content;
 
-  Utf8BytesSourceFile(this.filename, this.content);
+  Utf8BytesSourceFile(this.uri, this.content);
 
   String slowText() => UTF8.decode(content);
 
   List<int> slowUtf8Bytes() => content;
 
   String slowSubstring(int start, int end) {
     // TODO(lry): to make this faster, the scanner could record the UTF-8 slack
     // for all positions of the source text. We could use [:content.sublist:].
     return slowText().substring(start, end);
   }
 
   int get length {
     if (lengthCache == -1) {
       // During scanning the length is not yet assigned, so we use a slow path.
       length = slowText().length;
     }
     return lengthCache;
   }
   set length(int v) => lengthCache = v;
   int lengthCache = -1;
 }
 
 class CachingUtf8BytesSourceFile extends Utf8BytesSourceFile {
   String cachedText;
+  final String filename;
 
-  CachingUtf8BytesSourceFile(String filename, List<int> content)
-      : super(filename, content);
+  CachingUtf8BytesSourceFile(Uri uri, this.filename, List<int> content)
+      : super(uri, content);
 
   String slowText() {
     if (cachedText == null) {
       cachedText = super.slowText();
     }
     return cachedText;
   }
 }
 
 class StringSourceFile extends SourceFile {
+  final Uri uri;
   final String filename;
   final String text;
 
-  StringSourceFile(this.filename, this.text);
+  StringSourceFile(this.uri, this.filename, this.text);
+
+  StringSourceFile.fromUri(Uri uri, String text)
+      : this(uri, uri.toString(), text);
+
+  StringSourceFile.fromName(String filename, String text)
+      : this(new Uri(path: filename), filename, text);
 
   int get length => text.length;
   set length(int v) { }
 
   String slowText() => text;
 
   List<int> slowUtf8Bytes() => UTF8.encode(text);
 
   String slowSubstring(int start, int end) => text.substring(start, end);
 }