Make exception thrown via v8 public API propagate to v8::TryCatch as JS thrown exceptions do.

src/top.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 168 matching lines @@
 
   // Access to current thread id.
   static int thread_id() { return thread_local_.thread_id_; }
   static void set_thread_id(int id) { thread_local_.thread_id_ = id; }
 
   // Interface to pending exception.
   static MaybeObject* pending_exception() {
     ASSERT(has_pending_exception());
     return thread_local_.pending_exception_;
   }
-  static bool external_caught_exception() {
-    return thread_local_.external_caught_exception_;
-  }
   static void set_pending_exception(MaybeObject* exception) {
     thread_local_.pending_exception_ = exception;
   }
   static void clear_pending_exception() {
     thread_local_.pending_exception_ = Heap::the_hole_value();
   }
-
   static MaybeObject** pending_exception_address() {
     return &thread_local_.pending_exception_;
   }
   static bool has_pending_exception() {
     return !thread_local_.pending_exception_->IsTheHole();
   }
+
+  static bool external_caught_exception() {
+    return thread_local_.external_caught_exception_;
+  }
+  static void set_external_caught_exception(bool value) {
+    thread_local_.external_caught_exception_ = value;
+  }
+
   static void clear_pending_message() {
     thread_local_.has_pending_message_ = false;
     thread_local_.pending_message_ = NULL;
     thread_local_.pending_message_obj_ = Heap::the_hole_value();
     thread_local_.pending_message_script_ = NULL;
   }
   static v8::TryCatch* try_catch_handler() {
     return thread_local_.TryCatchHandler();
   }
   static Address try_catch_handler_address() {
@@ skipping 18 matching lines @@
     ASSERT(has_scheduled_exception());
     return thread_local_.scheduled_exception_;
   }
   static bool has_scheduled_exception() {
     return !thread_local_.scheduled_exception_->IsTheHole();
   }
   static void clear_scheduled_exception() {
     thread_local_.scheduled_exception_ = Heap::the_hole_value();
   }
 
-  static void setup_external_caught() {
-    thread_local_.external_caught_exception_ =
-        has_pending_exception() &&
-        (thread_local_.catcher_ != NULL) &&
-        (try_catch_handler() == thread_local_.catcher_);
-  }
-
   static void SetCaptureStackTraceForUncaughtExceptions(
       bool capture,
       int frame_limit,
       StackTrace::StackTraceOptions options);
 
   // Tells whether the current context has experienced an out of memory
   // exception.
   static bool is_out_of_memory();
 
   // JS execution stack (see frames.h).
@@ skipping 185 matching lines @@
 
   static inline ThreadLocalTop* GetCurrentThread() { return &thread_local_; }
   static int ArchiveSpacePerThread() { return sizeof(ThreadLocalTop); }
   static char* ArchiveThread(char* to);
   static char* RestoreThread(char* from);
   static void FreeThreadResources() { thread_local_.Free(); }
 
   static const char* kStackOverflowMessage;
 
  private:
+
+  static v8::TryCatch* catcher() {
+    return thread_local_.catcher_;
+  }
+
+  static void set_catcher(v8::TryCatch* catcher) {
+    thread_local_.catcher_ = catcher;
+  }
+
+  static void setup_external_caught() {
+    thread_local_.external_caught_exception_ =
+        has_pending_exception() &&
+        (thread_local_.catcher_ != NULL) &&
+        (try_catch_handler() == thread_local_.catcher_);
+  }
+
+  // Attempts to propagate the pending exception to the proper v8::TryCatch.
+  static void PropagatePendingExceptionToExternalTryCatch();
+
 #ifdef ENABLE_VMSTATE_TRACKING
   // Set of states used when communicating with the runtime profiler.
   //
   // The set of possible transitions is divided between the VM and the
   // profiler threads.
   //
   // The VM thread can perform these transitions:
   //   o IN_JS -> NOT_IN_JS
   //   o NOT_IN_JS -> IN_JS
   //   o NOT_IN_JS_WAITING_FOR_JS -> IN_JS notifying the profiler thread
@@ skipping 44 matching lines @@
   // Debug.
   // Mutex for serializing access to break control structures.
   static Mutex* break_access_;
 
   friend class SaveContext;
   friend class AssertNoContextChange;
   friend class ExecutionAccess;
   friend class ThreadLocalTop;
 
   static void FillCache();
+
+ public:
+  class ExceptionScope {
+   public:
+    ExceptionScope() :
+      // Scope currently can only be used for regular exceptions, not
+      // failures like OOM or termination exception.
+      pending_exception_(Top::pending_exception()->ToObjectUnchecked()),
+      external_caught_exception_(Top::external_caught_exception()),
+      catcher_(Top::catcher())
+    { }
+
+    ~ExceptionScope() {
+      Top::set_catcher(catcher_);
+      Top::set_external_caught_exception(external_caught_exception);
+      Top::set_pending_exception(*pending_exception_);
+    }
+
+   private:
+    Handle<Object> pending_exception_;
+    bool external_caught_exception_;
+    v8::TryCatch* catcher_;
+  };
 };
 
 
 // If the GCC version is 4.1.x or 4.2.x an additional field is added to the
 // class as a work around for a bug in the generated code found with these
 // versions of GCC. See V8 issue 122 for details.
 class SaveContext BASE_EMBEDDED {
  public:
   SaveContext()
       : context_(Top::context()),
@@ skipping 61 matching lines @@
   static void Unlock() { Top::break_access_->Unlock(); }
 
   static bool TryLock() {
     return Top::break_access_->TryLock();
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOP_H_