Snapshot DDC trained on itself

pkg/dev_compiler/lib/src/compiler/compiler.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:collection' show HashSet, Queue;
 import 'dart:convert' show JSON;
 import 'dart:io' show File;
 
 import 'package:analyzer/analyzer.dart'
     show AnalysisError, CompilationUnit, ErrorSeverity;
@@ skipping 379 matching lines @@
           hide: hide)
       ..addOption('summary-out',
           help: 'location to write the summary file', hide: hide);
   }
 
   static Map<String, String> _parseBazelMappings(Iterable argument) {
     var mappings = <String, String>{};
     for (var mapping in argument) {
       var splitMapping = mapping.split(',');
       if (splitMapping.length >= 2) {
-        mappings[path.absolute(splitMapping[0])] = splitMapping[1];
+        mappings[path.canonicalize(splitMapping[0])] = splitMapping[1];
       }
     }
     return mappings;
   }
 }
 
 /// A unit of Dart code that can be built into a single JavaScript module.
 class BuildUnit {
   /// The name of this module.
   final String name;
@@ skipping 168 matching lines @@
 
 /// Adjusts the source paths in [sourceMap] to be relative to [sourceMapPath],
 /// and returns the new map.  Relative paths are in terms of URIs ('/'), not
 /// local OS paths (e.g., windows '\').
 // TODO(jmesserly): find a new home for this.
 Map placeSourceMap(
     Map sourceMap, String sourceMapPath, Map<String, String> bazelMappings) {
   var map = new Map.from(sourceMap);
   // Convert to a local file path if it's not.
   sourceMapPath = path.fromUri(_sourceToUri(sourceMapPath));
-  var sourceMapDir = path.dirname(path.absolute(sourceMapPath));
+  var sourceMapDir = path.dirname(path.canonicalize(sourceMapPath));
   var list = new List.from(map['sources']);
   map['sources'] = list;
 
   String makeRelative(String sourcePath) {
     var uri = _sourceToUri(sourcePath);
     if (uri.scheme == 'dart' || uri.scheme == 'package') return sourcePath;
 
     // Convert to a local file path if it's not.
-    sourcePath = path.absolute(path.fromUri(uri));
+    sourcePath = path.canonicalize(path.fromUri(uri));
 
     // Allow bazel mappings to override.
     var match = bazelMappings[sourcePath];
     if (match != null) return match;
 
     // Fall back to a relative path against the source map itself.
     sourcePath = path.relative(sourcePath, from: sourceMapDir);
 
     // Convert from relative local path to relative URI.
     return path.toUri(sourcePath).path;
@@ skipping 12 matching lines @@
   var uri = Uri.parse(source);
   var scheme = uri.scheme;
   switch (scheme) {
     case "dart":
     case "package":
     case "file":
       // A valid URI.
       return uri;
     default:
       // Assume a file path.
-      return new Uri.file(path.absolute(source));
+      return new Uri.file(path.canonicalize(source));
   }
 }