Change lookup path for Dart native extensions shared libraries.

runtime/bin/extensions.cc

 // 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.
 
 #include "bin/extensions.h"
 
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/globals.h"
 #include "bin/dartutils.h"
+#include "bin/file.h"
 
 Dart_Handle Extensions::LoadExtension(const char* extension_url,
                                       Dart_Handle parent_library) {
   ASSERT(DartUtils::IsDartExtensionSchemeURL(extension_url));
   const char* library_name =
       extension_url + strlen(DartUtils::kDartExtensionScheme);
-  if (strchr(library_name, '/') != NULL ||
-      strchr(library_name, '\\') != NULL) {
+  if (strchr(library_name, '/') != library_name &&

[Mads Ager (google), 2012/03/14 10:29:47]

Is this because the extension url has been fully expanded before we get here? In
that case, could you add a comment about that. Please also update the error
message below which makes no sense now.

[Bill Hesse, 2012/03/14 17:15:04]

Eliminated.  We now allow paths.  Both absolute and relative paths should work,
but we will only be called with absolute paths.

On 2012/03/14 10:29:47, Mads Ager wrote:

+      strchr(library_name, '\\') != library_name) {
     return Dart_Error("path components not allowed in extension library name");
   }
   void* library_handle = LoadExtensionLibrary(library_name);
   if (!library_handle) {
     return Dart_Error("cannot find extension library");
   }
 
-  const char* strings[3] = { library_name, "_Init", NULL };
+  const char* last_path_separator =
+      strrchr(library_name, File::PathSeparator()[0]);

[Mads Ager (google), 2012/03/14 10:29:47]

If you are using PathSeparator here, couldn't you use that above as well instead
of checking for both '\\' and '/'?

[Bill Hesse, 2012/03/14 17:15:04]

Done.

+  if (last_path_separator == NULL) {
+    return Dart_Error("cannot find path separator in resolved extension name");
+  }
+  const char* extension_name = last_path_separator + 1;
+
+  const char* strings[3] = { extension_name, "_Init", NULL };
   char* init_function_name = Concatenate(strings);
   typedef Dart_Handle (*InitFunctionType)(Dart_Handle import_map);
   InitFunctionType fn = reinterpret_cast<InitFunctionType>(
       ResolveSymbol(library_handle, init_function_name));
   free(init_function_name);
 
   if (fn == NULL) {
     return Dart_Error("cannot find initialization function in extension");
   }
   return (*fn)(parent_library);
 }
 
 
 // Concatenates a NULL terminated array of strings.
 // The returned string must be freed.
 char* Extensions::Concatenate(const char** strings) {
   int size = 1;  // null termination.
   for (int i = 0; strings[i] != NULL; i++) {
     size += strlen(strings[i]);
   }
   char* result = reinterpret_cast<char*>(malloc(size));
   int index = 0;
   for (int i = 0; strings[i] != NULL; i++) {
     index += snprintf(result + index, size - index, "%s", strings[i]);
   }
   ASSERT(index == size - 1);
   ASSERT(result[size - 1] == '\0');
   return result;
 }