Don't use mirrors in pkg/path.

pkg/path/lib/path.dart

Index: pkg/path/lib/path.dart
diff --git a/pkg/path/lib/path.dart b/pkg/path/lib/path.dart
index da4c935f0bafb532b2c3cc0285d2303c18ba9429..276f396f779a3b07abda6a41e4873e2c9b66eb35 100644
--- a/pkg/path/lib/path.dart
+++ b/pkg/path/lib/path.dart
@@ -46,11 +46,6 @@
 /// even when the program is run on a POSIX machine.
 library path;
 
-@MirrorsUsed(targets: 'dart.dom.html.window, '
-    'dart.io.Directory.current, '
-    'dart.io.Platform.operatingSystem')
-import 'dart:mirrors';
-
 /// An internal builder for the current OS so we can provide a straight
 /// functional interface and not require users to create one.
 final _builder = new Builder();
@@ -69,19 +64,6 @@ final url = new Builder(style: Style.url);
 void _growListFront(List list, int length, fillValue) =>
   list.insertAll(0, new List.filled(length, fillValue));
 
-/// If we're running in the server-side Dart VM, this will return a
-/// [LibraryMirror] that gives access to the `dart:io` library.
-///
-/// If `dart:io` is not available, this returns null.
-LibraryMirror get _io => currentMirrorSystem().libraries[Uri.parse('dart:io')];
-
-// TODO(nweiz): when issue 6490 or 6943 are fixed, make this work under dart2js.
-/// If we're running in Dartium, this will return a [LibraryMirror] that gives
-/// access to the `dart:html` library.
-///
-/// If `dart:html` is not available, this returns null.
-LibraryMirror get _html =>
-  currentMirrorSystem().libraries[Uri.parse('dart:html')];
 
 /// Gets the path to the current working directory.
 ///
@@ -89,13 +71,13 @@ LibraryMirror get _html =>
 /// currently returns `.` due to technical constraints. In the future, it will
 /// return the current URL.

[nweiz, 2013/11/06 20:43:13]

The dart2js comment in this paragraph is no longer accurate. Also, "the current
URL" should be changed to describe the directory I mentioned below.

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

 String get current {
-  if (_io != null) {
-    return (_io.declarations[#Directory] as ClassMirror)
-        .getField(#current).reflectee.path;
-  } else if (_html != null) {
-    return _html.getField(#window).reflectee.location.href;
+  var uri = Uri.base;
+  if (Style.platform == Style.url) {
+    return uri.toString();

[nweiz, 2013/11/06 19:37:09]

We should be sure to return an actual directory here (this is also a problem
with the old code). It should be the same directory that's used to resolve
relative URLs. That means that if [uri] has a trailing slash, it should be [uri]
without that slash; otherwise, it should be `dirname(uri.toString())`.

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

   } else {
-    return '.';
+    var path = uri.toFilePath();
+    // Remove trailing '/' or '\'.
+    return path.substring(0, path.length - 1);

[nweiz, 2013/11/06 19:37:09]

Add an assertion that the last character is '/' or '\'.

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

   }
 }
 
@@ -866,14 +848,15 @@ abstract class Style {
 
   /// Gets the type of the host platform.
   static Style _getPlatformStyle() {
-    if (_io == null) return Style.url;
-
-    if ((_io.declarations[#Platform] as ClassMirror).getField(#operatingSystem)
-        .reflectee == 'windows') {
-      return Style.windows;
+    // The browser can not open a file, pointing to a directory, while also
+    // be running Dart scripts.

[nweiz, 2013/11/06 19:37:09]

I think this comment could be clearer. How about "If we're running a Dart file
in the browser from a file: URI, [Uri.base] will point to a file. If we're
running on the console, it will point to a directory. We can use that fact to
determine which style to use."

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

+    if (Uri.base.path.toString().endsWith('/') && Uri.base.scheme == 'file') {

[nweiz, 2013/11/06 19:37:09]

[Uri.base.path] is already a string; [toString] here is superfluous.

[Anders Johnsen, 2013/11/07 07:50:32]

Ah, yes, good catch!

+      if (new Uri.file('a/b').toFilePath() == 'a\\b') {

[nweiz, 2013/11/06 19:37:09]

Nit: the [new Uri.file] constructor here is unnecessary; just [new Uri] or
[Uri.parse] would work.

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

+        return Style.windows;
+      }
+      return Style.posix;
     }
-
-    return Style.posix;
+    return Style.url;

[nweiz, 2013/11/06 19:37:09]

Style suggestion: reduce the nesting here by re-ordering the conditionals. For
example:

if (Uri.base.scheme != 'file') return Style.url;
if (!Uri.base.path.endsWith('/')) return Style.url;
if (new Uri(path: 'a/b').toFilePath() == 'a\\b') return Style.windows;
return Style.posix;

[Anders Johnsen, 2013/11/07 07:50:32]

Done.

   }
 
   /// The name of this path style. Will be "posix" or "windows".