Introduce BeforeCallEnteredCallback.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 146 matching lines @@
 class CallDepthScope {
  public:
   explicit CallDepthScope(i::Isolate* isolate, Local<Context> context,
                           bool do_callback)
       : isolate_(isolate),
         context_(context),
         escaped_(false),
         do_callback_(do_callback) {
     // TODO(dcarney): remove this when blink stops crashing.
     DCHECK(!isolate_->external_caught_exception());
+    if (do_callback_) isolate_->FireBeforeCallEnteredCallback();

[dgozman, 2016/02/11 02:08:49]

I think I'd move this call after context->Enter() so that embedder can check in
which context we are about to execute.

     isolate_->IncrementJsCallsFromApiCounter();
     isolate_->handle_scope_implementer()->IncrementCallDepth();
     if (!context_.IsEmpty()) context_->Enter();
   }
   ~CallDepthScope() {
     if (!context_.IsEmpty()) context_->Exit();
     if (!escaped_) isolate_->handle_scope_implementer()->DecrementCallDepth();
     if (do_callback_) isolate_->FireCallCompletedCallback();
   }
 
@@ skipping 7187 matching lines @@
 
 
 void Isolate::SetEventLogger(LogEventCallback that) {
   // Do not overwrite the event logger if we want to log explicitly.
   if (i::FLAG_log_internal_timer_events) return;
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->set_event_logger(that);
 }
 
 
+void Isolate::AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback) {
+  if (callback == NULL) return;
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->AddBeforeCallEnteredCallback(callback);
+}
+
+
+void Isolate::RemoveBeforeCallEnteredCallback(
+    BeforeCallEnteredCallback callback) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->RemoveBeforeCallEnteredCallback(callback);
+}
+
+
 void Isolate::AddCallCompletedCallback(CallCompletedCallback callback) {
   if (callback == NULL) return;
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->AddCallCompletedCallback(callback);
 }
 
 
 void Isolate::RemoveCallCompletedCallback(CallCompletedCallback callback) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->RemoveCallCompletedCallback(callback);
@@ skipping 1170 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8