Add Dart_GetStickyError

runtime/vm/dart_api_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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "lib/stacktrace.h"
@@ skipping 1449 matching lines @@
   }
 }
 
 
 DART_EXPORT void Dart_SetStickyError(Dart_Handle error) {
   Thread* thread = Thread::Current();
   DARTSCOPE(thread);
   Isolate* isolate = thread->isolate();
   CHECK_ISOLATE(isolate);
   NoSafepointScope no_safepoint_scope;
-  if (isolate->sticky_error() != Error::null()) {
+  if ((isolate->sticky_error() != Error::null()) && !::Dart_IsNull(error)) {
     FATAL1("%s expects there to be no sticky error.", CURRENT_FUNC);
   }
-  if (!::Dart_IsUnhandledExceptionError(error)) {
-    FATAL1("%s expects the error to be an unhandled exception error.",
+  if (!::Dart_IsUnhandledExceptionError(error) && !::Dart_IsNull(error)) {
+    FATAL1("%s expects the error to be an unhandled exception error or null.",
             CURRENT_FUNC);
   }
   isolate->SetStickyError(
       Api::UnwrapErrorHandle(Z, error).raw());
 }
 
 
 DART_EXPORT bool Dart_HasStickyError() {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   NoSafepointScope no_safepoint_scope;
   return isolate->sticky_error() != Error::null();
 }
 
 
+DART_EXPORT Dart_Handle Dart_GetStickyError() {
+  Isolate* I = Isolate::Current();
+  CHECK_ISOLATE(I);

[siva, 2016/09/22 19:43:54]

Other places we use the pattern
  Thread* T = Thread::Current();
  Isolate* I = T->isolate();
  CHECK_ISOLATE(I);
  .....
Then T is available to use inside the function instead of Thread::Current();

+  NoSafepointScope no_safepoint_scope;
+  if (I->sticky_error() != Object::null()) {

[siva, 2016/09/22 19:43:54]

if (I->sticky_error() != Error::null()) {

+    Dart_Handle error =
+        Api::NewHandle(Thread::Current(), I->sticky_error());

[siva, 2016/09/22 19:43:54]

NewHandle(T, ...);

+    return error;
+  }
+  return Dart_Null();
+}
+
+
 DART_EXPORT void Dart_ExitIsolate() {
   Thread* T = Thread::Current();
   CHECK_ISOLATE(T->isolate());
   // The Thread structure is disassociated from the isolate, we do the
   // safepoint transition explicity here instead of using the TransitionXXX
   // scope objects as the original transition happened outside this scope in
   // Dart_EnterIsolate/Dart_CreateIsolate.
   ASSERT(T->execution_state() == Thread::kThreadInNative);
   T->ExitSafepoint();
   T->set_execution_state(Thread::kThreadInVM);
@@ skipping 5100 matching lines @@
 
 DART_EXPORT bool Dart_IsPrecompiledRuntime() {
 #if defined(DART_PRECOMPILED_RUNTIME)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace dart