Add an API for setting the sticky error

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 1432 matching lines @@
 DART_EXPORT void Dart_SetPausedOnExit(bool paused) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   NoSafepointScope no_safepoint_scope;
   if (isolate->message_handler()->is_paused_on_exit() != paused) {
     isolate->message_handler()->PausedOnExit(paused);
   }
 }
 
 
+DART_EXPORT void Dart_SetStickyError(Dart_Handle error) {
+  Thread* thread = Thread::Current();
+  Isolate* isolate = thread->isolate();
+  CHECK_ISOLATE(isolate);

[siva, 2016/08/08 17:53:45]

Probably better to create a scope here as we will be creating a handle below
when Api::UnwrapErrorHandle is called. If this function is called too many times
we might end up with handles in the top most scope (kind of a leak).

DARTSCOPE(Thread::Current());
Isolate* I = T->isolate();

[Cutch, 2016/08/08 19:14:30]

Done.

+  NoSafepointScope no_safepoint_scope;
+  if (isolate->sticky_error() != Error::null()) {
+    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.",
+            CURRENT_FUNC);
+  }
+  isolate->SetStickyError(
+      Api::UnwrapErrorHandle(thread->zone(), error).raw());

[siva, 2016/08/08 17:53:45]

you could use Z here instead of thread->zone() to be consistent with the rest of
the file.

[Cutch, 2016/08/08 19:14:30]

Done.

+}
+
+
+DART_EXPORT bool Dart_HasStickyError() {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  NoSafepointScope no_safepoint_scope;
+  return isolate->sticky_error() != Error::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 5099 matching lines @@
 
 DART_EXPORT bool Dart_IsPrecompiledRuntime() {
 #if defined(DART_PRECOMPILED_RUNTIME)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace dart