Add SetAbortOnUncaughtExceptionCallback API

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 3fff6b2ef7a491d5f0ac3c0a93b70bef3ae0827d..ae49397369dc10bc194b26a7b1000144b14d7633 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1014,11 +1014,21 @@ Object* Isolate::Throw(Object* exception, MessageLocation* location) {
       // print a user-friendly stack trace (not an internal one).
       if (FLAG_abort_on_uncaught_exception &&
           PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT) {
-        FLAG_abort_on_uncaught_exception = false;  // Prevent endless recursion.
-        PrintF(stderr, "%s\n\nFROM\n",
-               MessageHandler::GetLocalizedMessage(this, message_obj).get());
-        PrintCurrentStackTrace(stderr);
-        base::OS::Abort();
+        // If the embedder didn't specify a custom uncaught exception callback,
+        // or if the custom callback determined that V8 should abort, then
+        // abort.
+        bool should_abort = !abort_on_uncaught_exception_callback_ ||

[Michael Starzinger, 2015/10/05 16:13:57]

Suggestion: I would even inline the whole predicate into the if-statement below
and not have the "should_abort" local variable actually. But that's just taste,
it's up to you.

[julien.gilli, 2015/10/05 17:24:25]

Done.

[julien.gilli, 2015/10/05 17:24:25]

I agree that the "should_abort" local variable doesn't make things any clearer.
What about moving the predicate in the if-statement above like following:

if (FLAG_abort_on_uncaught_exception &&
          PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT &&
          (!abort_on_uncaught_exception_callback_ ||
            abort_on_uncaught_exception_callback_(
                reinterpret_cast<v8::Isolate*>(this)))) {

?

[Michael Starzinger, 2015/10/05 17:39:06]

Acknowledged. Works for me.

+                            abort_on_uncaught_exception_callback_(
+                                reinterpret_cast<v8::Isolate*>(this));
+
+        if (should_abort) {
+          // Prevent endless recursion.
+          FLAG_abort_on_uncaught_exception = false;
+          PrintF(stderr, "%s\n\nFROM\n",
+                 MessageHandler::GetLocalizedMessage(this, message_obj).get());
+          PrintCurrentStackTrace(stderr);
+          base::OS::Abort();
+        }
       }
     }
   }
@@ -1602,6 +1612,12 @@ void Isolate::SetCaptureStackTraceForUncaughtExceptions(
 }
 
 
+void Isolate::SetAbortOnUncaughtExceptionCallback(
+    v8::Isolate::AbortOnUncaughtExceptionCallback callback) {
+  abort_on_uncaught_exception_callback_ = callback;
+}
+
+
 Handle<Context> Isolate::native_context() {
   return handle(context()->native_context());
 }
@@ -1770,7 +1786,8 @@ Isolate::Isolate(bool enable_serializer)
       next_unique_sfi_id_(0),
 #endif
       use_counter_callback_(NULL),
-      basic_block_profiler_(NULL) {
+      basic_block_profiler_(NULL),
+      abort_on_uncaught_exception_callback_(NULL) {
   {
     base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
     CHECK(thread_data_table_);