Canonicalize uris in C++ instead of Dart for the standalone embedder.

runtime/bin/builtin.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 builtin;
 // NOTE: Do not import 'dart:io' in builtin.
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_internal';
 import 'dart:isolate';
@@ skipping 307 matching lines @@
   }
   if (_traceLoading) {
     _log("Resolved '$uri' to '$resolvedUri'.");
   }
   return resolvedUri;
 }
 
 
 // Resolves the script uri in the current working directory iff the given uri
 // did not specify a scheme (e.g. a path to a script file on the command line).
 Uri _resolveScriptUri(String scriptName) {

[Cutch, 2016/05/24 23:53:46]

We need to get rid of this function too. If new API allowed providing a base
directly, we could just call it with the working directory and the script name.

[turnidge, 2016/05/31 18:25:27]

I would rather hold off on exposing the api in that form for a bit, until we
merge your upcoming changes with my work.

   if (_traceLoading) {
     _log("Resolving script: $scriptName");
   }
   if (_workingDirectory == null) {
     throw 'No current working directory set.';
   }
   scriptName = _sanitizeWindowsPath(scriptName);
 
   var scriptUri = Uri.parse(scriptName);
   if (scriptUri.scheme == '') {
@@ skipping 345 matching lines @@
   if (tag == _Dart_kScriptTag) {
     resourceUri = _resolveScriptUri(uri);
     uri = resourceUri.toString();
   } else {
     resourceUri = Uri.parse(uri);
   }
   _loadData(tag, uri, resourceUri, libraryUri);
 }
 
 
-// Embedder Entrypoint:
-// Function called by standalone embedder to resolve uris when the VM requests
-// Dart_kCanonicalizeUrl from the tag handler.
-String _resolveUri(String base, String userString) {
-  if (!_setupCompleted) {
-    _setupHooks();
-  }
-  if (_traceLoading) {
-    _log('Resolving: $userString from $base');
-  }
-  var baseUri = Uri.parse(base);
-  var result = baseUri.resolve(userString).toString();
-  if (_traceLoading) {
-    _log('Resolved $userString in $base to $result');
-  }
-  return result;
-}
-
-
 // Handling of access to the package root or package map from user code.
 _triggerPackageResolution(action) {
   if (_packagesReady) {
     // Packages are ready. Execute the action now.
     action();
   } else {
     if (_pendingPackageLoads.isEmpty) {
       // Package resolution has not been setup yet, and this is the first
       // request for package resolution & loading.
       _requestPackagesMap();
@@ skipping 149 matching lines @@
 
 // Register callbacks and hooks with the rest of the core libraries.
 _setupHooks() {
   _setupCompleted = true;
   VMLibraryHooks.resourceReadAsBytes = _resourceReadAsBytes;
 
   VMLibraryHooks.packageRootUriFuture = _getPackageRootFuture;
   VMLibraryHooks.packageConfigUriFuture = _getPackageConfigFuture;
   VMLibraryHooks.resolvePackageUriFuture = _resolvePackageUriFuture;
 }