Revert "Store library paths relative to a given application root folder."

pkg/kernel/lib/repository.dart

Index: pkg/kernel/lib/repository.dart
diff --git a/pkg/kernel/lib/repository.dart b/pkg/kernel/lib/repository.dart
index d24748c0ea641ba0ee7b5bfb2f75b53a923d9b4c..7689d90f162bf639101e33c76f5e594955c8ccf7 100644
--- a/pkg/kernel/lib/repository.dart
+++ b/pkg/kernel/lib/repository.dart
@@ -3,6 +3,10 @@
 // BSD-style license that can be found in the LICENSE file.
 library kernel.repository;
 
+import 'dart:io';
+
+import 'package:path/path.dart' as pathlib;
+
 import 'ast.dart';
 
 /// Keeps track of which [Library] objects have been created for a given URI.
@@ -10,18 +14,61 @@ import 'ast.dart';
 /// To load different files into the same IR, pass in the same repository
 /// object to the loaders.
 class Repository {
+  final String workingDirectory;
   final Map<Uri, Library> _uriToLibrary = <Uri, Library>{};
   final List<Library> libraries = <Library>[];
 
+  Repository({String workingDirectory})
+      : this.workingDirectory = workingDirectory ?? Directory.current.path;
+
+  /// Get the [Library] object for the library addresesd by [path]; possibly
+  /// as an external library.
+  ///
+  /// The [path] may be a relative or absolute file path, or a URI string with a
+  /// `dart:`, `package:` or `file:` scheme.
+  ///
+  /// Note that this method does not check if the library can be loaded at all.
+  Library getLibrary(String path) {
+    return getLibraryReference(normalizePath(path));
+  }
+
+  String normalizeFileExtension(String path) {
+    if (path.endsWith('.dill')) {
+      return path.substring(0, path.length - '.dill'.length) + '.dart';
+    } else {
+      return path;
+    }
+  }
+
+  /// Get the canonical URI for the library addressed by the given [path].
+  ///
+  /// The [path] may be a relative or absolute file path, or a URI string with a
+  /// `dart:`, `package:` or `file:` scheme.
+  Uri normalizePath(String path) {
+    var uri = Uri.parse(path);
+    if (!uri.hasScheme) {
+      if (!pathlib.isAbsolute(path)) {
+        path = pathlib.join(workingDirectory, path);
+      }
+      uri = new Uri(scheme: 'file', path: normalizeFileExtension(path));
+    } else if (uri.scheme == 'file') {
+      var path = normalizeFileExtension(uri.path);
+      if (!uri.hasAbsolutePath) {
+        uri = uri.replace(path: pathlib.join(workingDirectory, path));
+      } else {
+        uri = uri.replace(path: path);
+      }
+    }
+    return uri;
+  }
+
   Library getLibraryReference(Uri uri) {
     assert(uri.hasScheme);
+    assert(uri.scheme != 'file' || uri.hasAbsolutePath);
     return _uriToLibrary.putIfAbsent(uri, () => _buildLibraryReference(uri));
   }
 
   Library _buildLibraryReference(Uri uri) {
-    assert(uri.hasScheme);
-    assert(uri.scheme != 'file');
-    assert(!uri.hasAbsolutePath);
     var library = new Library(uri, isExternal: true);
     libraries.add(library);
     return library;