VM: Support bootstrapping core libraries from Kernel binaries instead of source.

runtime/bin/vmservice_impl.cc

 // Copyright (c) 2013, 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/vmservice_impl.h"
 
 #include "include/dart_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
@@ skipping 137 matching lines @@
 }
 
 
 const char* VmService::error_msg_ = NULL;
 char VmService::server_uri_[kServerUriStringBufferSize];
 
 
 bool VmService::LoadForGenPrecompiled() {
   Dart_Handle result;
   Dart_SetLibraryTagHandler(LibraryTagHandler);
-  Dart_Handle library = LoadLibrary(kVMServiceIOLibraryScriptResourceName);
+  Dart_Handle library =
+      LookupOrLoadLibrary(kVMServiceIOLibraryScriptResourceName);
   ASSERT(library != Dart_Null());
   SHUTDOWN_ON_ERROR(library);
   result = Dart_SetNativeResolver(library, VmServiceIONativeResolver, NULL);
   SHUTDOWN_ON_ERROR(result);
   result = Dart_FinalizeLoading(false);
   SHUTDOWN_ON_ERROR(result);
   return true;
 }
 
 
@@ skipping 138 matching lines @@
 }
 
 
 Dart_Handle VmService::LoadScript(const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(kVMServiceIOLibraryUri);
   Dart_Handle source = GetSource(name);
   return Dart_LoadScript(uri, Dart_Null(), source, 0, 0);
 }
 
 
-Dart_Handle VmService::LoadLibrary(const char* name) {
+Dart_Handle VmService::LookupOrLoadLibrary(const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(kVMServiceIOLibraryUri);
-  Dart_Handle source = GetSource(name);
-  return Dart_LoadLibrary(uri, Dart_Null(), source, 0, 0);
+  Dart_Handle library = Dart_LookupLibrary(uri);
+  if (!Dart_IsLibrary(library)) {
+    Dart_Handle source = GetSource(name);
+    library = Dart_LoadLibrary(uri, Dart_Null(), source, 0, 0);
+  }
+  return library;
 }
 
 
 Dart_Handle VmService::LoadSource(Dart_Handle library, const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(name);
   Dart_Handle source = GetSource(name);
   return Dart_LoadSource(library, uri, Dart_Null(), source, 0, 0);
 }
 
 
@@ skipping 29 matching lines @@
   Dart_Handle source = GetSource(url_string);
   if (Dart_IsError(source)) {
     return source;
   }
   return Dart_LoadSource(library, url, Dart_Null(), source, 0, 0);
 }
 
 
 }  // namespace bin
 }  // namespace dart