Change lookup path for Dart native extensions shared libraries.

runtime/bin/extensions.cc

Index: runtime/bin/extensions.cc
diff --git a/runtime/bin/extensions.cc b/runtime/bin/extensions.cc
index afcb29fdc52a10ba9222e1c0c63e68becdcad562..e7ccabb1533b494266e0069d279678973fa32bab 100644
--- a/runtime/bin/extensions.cc
+++ b/runtime/bin/extensions.cc
@@ -10,14 +10,15 @@
 #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);
@@ -25,7 +26,14 @@ Dart_Handle Extensions::LoadExtension(const char* extension_url,
     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>(