Provide a counter for thrown JavaScript errors per context

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1001 matching lines @@
 
     if (bootstrapper()->IsActive()) {
       // It's not safe to try to make message objects or collect stack traces
       // while the bootstrapper is active since the infrastructure may not have
       // been properly initialized.
       ReportBootstrappingException(exception_handle, location);
     } else {
       Handle<Object> message_obj = CreateMessage(exception_handle, location);
       thread_local_top()->pending_message_obj_ = *message_obj;
 
+      bool exception_is_uncaught = (
+        PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT);

[Michael Starzinger, 2015/10/29 13:42:55]

Notes about PredictExceptionCatcher:

1) Calling this method is not entirely for free. It will perform a stack-walk
and lookups in handler tables.
2) It can only produce an estimate (i.e. educated guess) about whether the
exception will be caught by JavaScript or not. The question whether an exception
will be caught or not is undecidable here (i.e. at the throw-site).

[Michael Hablich, 2015/10/29 15:23:34]

I moved the whole counting into the factory which should count the right things.

+
+      if (exception_is_uncaught) context()->IncrementExceptionsThrown();

[jochen (gone - plz use gerrit), 2015/10/29 14:37:07]

use native_context()

[Michael Hablich, 2015/10/29 15:23:34]

Done.

+
       // For any exception not caught by JavaScript, even when an external
       // handler is present:
       // If the abort-on-uncaught-exception flag is specified, and if the
       // embedder didn't specify a custom uncaught exception callback,
       // or if the custom callback determined that V8 should abort, then
       // abort.
       if (FLAG_abort_on_uncaught_exception &&
-          PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT &&
+          exception_is_uncaught &&
           (!abort_on_uncaught_exception_callback_ ||
            abort_on_uncaught_exception_callback_(
                reinterpret_cast<v8::Isolate*>(this)))) {
         // Prevent endless recursion.
         FLAG_abort_on_uncaught_exception = false;
         // This flag is intended for use by JavaScript developers, so
         // print a user-friendly stack trace (not an internal one).
         PrintF(stderr, "%s\n\nFROM\n",
                MessageHandler::GetLocalizedMessage(this, message_obj).get());
         PrintCurrentStackTrace(stderr);
@@ skipping 1808 matching lines @@
   // First check whether the previous scope intercepts.
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
+
 }  // namespace internal
 }  // namespace v8