Add more tests for compiler-dispatcher

src/compiler-dispatcher/compiler-dispatcher.cc

Index: src/compiler-dispatcher/compiler-dispatcher.cc
diff --git a/src/compiler-dispatcher/compiler-dispatcher.cc b/src/compiler-dispatcher/compiler-dispatcher.cc
index 47c04b8b44a39792173dd26443179bf137f9745e..782a6ed855ea78a03f7e9829ef6f33b966e515fa 100644
--- a/src/compiler-dispatcher/compiler-dispatcher.cc
+++ b/src/compiler-dispatcher/compiler-dispatcher.cc
@@ -22,7 +22,6 @@ enum class ExceptionHandling { kSwallow, kThrow };
 bool DoNextStepOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
                             ExceptionHandling exception_handling) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
-  v8::TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));

[jochen (gone - plz use gerrit), 2017/01/04 08:23:22]

turns out that we only create a pending exception, but don't schedule it, so the
trycatch did nothing

   switch (job->status()) {
     case CompileJobStatus::kInitial:
       job->PrepareToParseOnMainThread();
@@ -53,10 +52,13 @@ bool DoNextStepOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
       break;
   }
 
-  if (exception_handling == ExceptionHandling::kThrow &&
-      try_catch.HasCaught()) {
-    DCHECK(job->status() == CompileJobStatus::kFailed);
-    try_catch.ReThrow();
+  if (job->status() == CompileJobStatus::kFailed) {
+    DCHECK(isolate->has_pending_exception());
+    if (exception_handling == ExceptionHandling::kSwallow) {
+      isolate->clear_pending_exception();
+    }
+  } else {
+    DCHECK(!isolate->has_pending_exception());
   }

[vogelheim, 2017/01/04 10:08:49]

nitpick: Hmm... How about:

DCHECK_EQ(job->status() == CompileJobStatus::kFailed,
          isolate->has_pending_exception());
if (ob->status() == CompileJobStatus::kFailed
    && exception_handling == ExceptionHandling::kSwallow)
  isolate->clear_pending_exception();

[jochen (gone - plz use gerrit), 2017/01/04 10:23:18]

will do in a follow-up

   return job->status() != CompileJobStatus::kFailed;
 }