Search for a native extension for the host architecture

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 804 matching lines @@
     _log('Resolved in working directory: $fileName -> $uri');
   }
   return uri.toString();
 }
 
 
 // Handling of dart-ext loading.
 // Dart native extension scheme.
 const _DART_EXT = 'dart-ext:';
 
-String _nativeLibraryExtension() native "Builtin_NativeLibraryExtension";
-
-
-String _platformExtensionFileName(String name) {
-  var extension = _nativeLibraryExtension();
-
-  if (_isWindows) {
-    return '$name.$extension';
-  } else {
-    return 'lib$name.$extension';
-  }
-}
-
-
 // Returns either a file path or a URI starting with http[s]:, as a String.
 String _filePathFromUri(String userUri) {
   var uri = Uri.parse(userUri);
   if (_traceLoading) {
     _log('Getting file path from: $uri');
   }
 
   var path;
   switch (uri.scheme) {
     case '':
@@ skipping 42 matching lines @@
   int index = userUri.lastIndexOf('/');
   if (index == -1) {
     name = userUri;
     path = './';
   } else if (index == userUri.length - 1) {
     throw 'Extension name missing in $extensionUri';
   } else {
     name = userUri.substring(index + 1);
     path = userUri.substring(0, index + 1);
   }
+  path = _filePathFromUri(path);
 
-  path = _filePathFromUri(path);
-  var filename = _platformExtensionFileName(name);
-
-  return [path, filename, name];
+  return [path, name];
 }
 
 
 // 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;
 }