Load vmservice from a .dill file when generating AOT snapshots.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index fa48aeee52b36bf6c82b24b8434e6451cbb43796..c81951415aa690196425584d12f93ca28795d66e 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -60,6 +60,7 @@ namespace dart {
 #define Z (T->zone())
 
 
+DECLARE_FLAG(bool, use_dart_frontend);
 DECLARE_FLAG(bool, print_class_table);
 DECLARE_FLAG(bool, verify_handles);
 #if defined(DART_NO_SNAPSHOT)
@@ -5642,6 +5643,22 @@ DART_EXPORT Dart_Handle Dart_LibraryHandleError(Dart_Handle library_in,
 }
 
 
+#if !defined(DART_PRECOMPILED_RUNTIME)
+static Dart_Handle LoadLibraryFromKernel(Thread* T, void* kernel_program) {

[siva, 2017/06/22 23:51:37]

Is it LoadLibraryFromKernel or LoadKernelProgram as we can also use this
abstraction for LoadScript.

[sivachandra, 2017/06/23 01:14:57]

Done.

+  kernel::KernelReader reader(
+      reinterpret_cast<kernel::Program*>(kernel_program));
+  const Object& tmp = reader.ReadProgram();
+  if (tmp.IsError()) {
+    return Api::NewHandle(T, tmp.raw());
+  }
+
+  Library& library = Library::Handle(T->zone());
+  library ^= tmp.raw();
+  return Api::NewHandle(T, library.raw());

[siva, 2017/06/22 23:51:37]

I think currently reader.ReadProgram returns the library that has 'main' in it
otherwise it returns null.

You may have to instead call Library::LookupLibrary(T, url) to get the library
object and return it.

[sivachandra, 2017/06/23 01:14:57]

Done.

+}
+#endif
+
+
 DART_EXPORT Dart_Handle Dart_LoadLibrary(Dart_Handle url,
                                          Dart_Handle resolved_url,
                                          Dart_Handle source,
@@ -5650,6 +5667,16 @@ DART_EXPORT Dart_Handle Dart_LoadLibrary(Dart_Handle url,
   API_TIMELINE_DURATION;
   DARTSCOPE(Thread::Current());
   Isolate* I = T->isolate();
+
+#if !defined(DART_PRECOMPILED_RUNTIME)
+  // Kernel isolate is loaded from script in case of dart_bootstrap
+  // even when FLAG_use_dart_frontend is true. Hence, do not interpret
+  // |source| as a kernel if the current isolate is the kernel isolate.
+  if (FLAG_use_dart_frontend && !KernelIsolate::IsKernelIsolate(I)) {
+    return LoadLibraryFromKernel(T, reinterpret_cast<void*>(source));
+  }
+#endif
+
   const String& url_str = Api::UnwrapStringHandle(Z, url);
   if (url_str.IsNull()) {
     RETURN_TYPE_ERROR(Z, url, String);