Fix the dartdoc build.

sdk/lib/_internal/dartdoc/bin/dartdoc.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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
  * This will create a "docs" directory with the docs for your libraries. To
  * create these beautiful docs, dartdoc parses your library and every library
  * it imports (recursively). From each library, it parses all classes and
  * members, finds the associated doc comments and builds crosslinked docs from
  * them.
  */
 library dartdoc;
 
 import 'dart:async';
 import 'dart:io';
 
 // TODO(rnystrom): Use "package:" URL (#4968).
 import '../lib/dartdoc.dart';
+import '../lib/src/dartdoc/utils.dart';
 import 'package:args/args.dart';
 import 'package:pathos/path.dart' as path;
 
 /**
  * Run this from the `lib/_internal/dartdoc` directory.
  */
 main() {
   // Need this because ArgParser.getUsage doesn't show command invocation.
   final USAGE = 'Usage dartdoc [options] <entrypoint(s)>\n[options] include:';
 
@@ skipping 147 matching lines @@
 
   dartdoc.dartdocPath = libPath.append('lib/_internal/dartdoc');
 
   if (args.isEmpty) {
     print('No arguments provided.');
     print(USAGE);
     print(argParser.getUsage());
     exit(1);
   }
 
-  final entrypoints = <String>[];
+  final entrypoints = <Uri>[];
   try {
     final option = argParser.parse(args);
 
     // This checks to see if the root of all entrypoints is the same.
     // If it is not, then we display a warning, as package imports might fail.
     var entrypointRoot;
     for (final entrypoint in option.rest) {
-      entrypoints.add(entrypoint);
+      var uri = Uri.parse(entrypoint);
+      if (uri.scheme == '') uri = pathToFileUri(entrypoint);
+      entrypoints.add(uri);
 
+      if (uri.scheme != 'file') continue;
       if (entrypointRoot == null) {
         entrypointRoot = path.dirname(entrypoint);
       } else if (entrypointRoot != path.dirname(entrypoint)) {
         print('Warning: entrypoints are at different directories. "package:"'
             ' imports may fail.');
       }
     }
   } on FormatException catch (e) {
     print(e.message);
     print(USAGE);
     print(argParser.getUsage());
     exit(1);
   }
 
   if (entrypoints.isEmpty) {
     print('No entrypoints provided.');
     print(argParser.getUsage());
     exit(1);
   }
 
-  if (packageRoot == null) {
-    // Check if there's a `packages` directory in the entry point directory.
-    var script = path.normalize(path.absolute(entrypoints[0]));
-    var dir = path.join(path.dirname(script), 'packages/');
-    if (new Directory(dir).existsSync()) {
-      packageRoot = dir;
-    } else {
-      // If there is not, then check if the entrypoint is somewhere in a `lib`
-      // directory.
-      dir = path.dirname(script);
-      var parts = path.split(dir);
-      var libDir = parts.lastIndexOf('lib');
-      if (libDir > 0) {
-        packageRoot = path.join(path.joinAll(parts.take(libDir)), 'packages');
-      }
-    }
-  }
+  if (packageRoot == null) packageRoot = _getPackageRoot(entrypoints);
 
   cleanOutputDirectory(dartdoc.outputDir);
 
   // Start the analysis and documentation.
   dartdoc.documentLibraries(entrypoints, libPath, packageRoot)
     .then((_) {
       print('Copying static files...');
       Future.wait([
         // Prepare the dart2js script code and copy static resources.
         // TODO(amouravski): move compileScript out and pre-generate the client
         // scripts. This takes a long time and the js hardly ever changes.
         compileScript(dartdoc.mode, dartdoc.outputDir, libPath),
         copyDirectory(scriptDir.append('../static'), dartdoc.outputDir)
       ]);
     })
     .then((_) {
       print(dartdoc.status);
       if (dartdoc.totals == 0) {
         exit(1);
       }
     })
     .catchError((e) {
       print('Error: generation failed: ${e}');
       dartdoc.cleanup();
       exit(1);
     })
     .whenComplete(() => dartdoc.cleanup());
 }
+
+String _getPackageRoot(List<Uri> entrypoints) {
+  // Check if there's a `packages` directory in the entry point directory.
+  var fileEntrypoint = entrypoints.firstWhere(
+      (entrypoint) => entrypoint.scheme == 'file',
+      orElse: () => null);
+  if (fileEntrypoint != null) {
+    var script = path.normalize(path.absolute(fileUriToPath(fileEntrypoint)));
+    var dir = path.join(path.dirname(script), 'packages/');
+    if (new Directory(dir).existsSync()) return dir;
+  }
+
+  // If there is not, then check if the entrypoint is somewhere in a `lib`
+  // directory.
+  dir = path.dirname(script);
+  var parts = path.split(dir);
+  var libDir = parts.lastIndexOf('lib');
+  if (libDir > 0) {
+    return path.join(path.joinAll(parts.take(libDir)), 'packages');
+  } else {
+    return null;
+  }
+}