[inspector] introduced debug::SetCompileEventListener

src/debug/debug.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/debug/debug.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 1856 matching lines @@
   async_task_listener_ = listener;
   async_task_listener_data_ = data;
   UpdateState();
 }
 
 void Debug::OnAsyncTaskEvent(debug::PromiseDebugActionType type, int id) {
   if (in_debug_scope() || ignore_events()) return;
 
   if (async_task_listener_) {
     async_task_listener_(type, id, async_task_listener_data_);
-    // There are three types of event listeners: C++ message_handler,
-    // JavaScript event listener and C++ event listener.
-    // Currently inspector still uses C++ event listener and installs
-    // more specific event listeners for part of events. Calling of
-    // C++ event listener is redundant when more specific event listener
-    // is presented. Other clients can install JavaScript event listener
-    // (e.g. some of NodeJS module).
-    bool non_inspector_listener_exists =
-        message_handler_ != nullptr ||
-        (event_listener_.is_null() && !event_listener_->IsForeign());
-    if (!non_inspector_listener_exists) return;
+    if (!non_inspector_listener_exists()) return;
   }
 
   HandleScope scope(isolate_);
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return;
 
   // Create the script collected state object.
   Handle<Object> event_data;
   // Bail out and don't call debugger if exception.
   if (!MakeAsyncTaskEvent(handle(Smi::FromInt(type), isolate_),
@@ skipping 58 matching lines @@
                               event_listener_data_ };
     Handle<JSReceiver> global = isolate_->global_proxy();
     MaybeHandle<Object> result =
         Execution::Call(isolate_, Handle<JSFunction>::cast(event_listener_),
                         global, arraysize(argv), argv);
     CHECK(!result.is_null());  // Listeners must not throw.
   }
   in_debug_event_listener_ = previous;
 }
 
+void Debug::SetCompileEventListener(debug::CompileEventListener listener,
+                                    void* data) {
+  compile_event_listener_ = listener;
+  compile_event_listener_data_ = data;
+  UpdateState();
+}
 
 void Debug::ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script) {
   if (ignore_events()) return;
   if (script->type() != i::Script::TYPE_NORMAL &&
       script->type() != i::Script::TYPE_WASM) {
     return;
   }
   SuppressDebug while_processing(this);

[kozy, 2017/01/17 17:14:09]

test/debug relies on this (e.g. debug-step-stub-callfunction.js): inspector
doesn't really need this suppression but if we move this line after calling
callback then we will pause inside of test-api.js file and will ignore this
pause because of [1], I think we should be better inside test-api.js and if
stepping action was scheduled then repeat last scheduled action instead of
silent ignorance. Jacob, WDYT?

[1]
https://cs.chromium.org/chromium/src/v8/test/debugger/test-api.js?rcl=0&l=830 

[jgruber, 2017/01/18 10:25:34]

Good point, the current solution in test-api.js is suboptimal. What we really
need is blackboxing of everything in test-api.js (and probably the registered JS
listener). Created https://bugs.chromium.org/p/v8/issues/detail?id=5859 to track
this.

 
+  if (compile_event_listener_) {
+    compile_event_listener_(ToApiHandle<debug::Script>(script),
+                            event != v8::AfterCompile,
+                            compile_event_listener_data_);
+    if (!non_inspector_listener_exists()) return;
+  }
+
   bool in_nested_debug_scope = in_debug_scope();
   HandleScope scope(isolate_);
   DebugScope debug_scope(this);

[Yang, 2017/01/18 11:41:08]

I think we need to move the DebugScope above the compile listener call. Inside a
debug scope, we do not perform stepping.

[kozy, 2017/01/18 20:00:02]

Done.

   if (debug_scope.failed()) return;
 
   // Create the compile state object.
   Handle<Object> event_data;
   // Bail out and don't call debugger if exception.
   if (!MakeCompileEvent(script, event).ToHandle(&event_data)) return;
 
   // Don't call NotifyMessageHandler if already in debug scope to avoid running
   // nested command loop.
   if (in_nested_debug_scope) {
@@ skipping 175 matching lines @@
   UpdateState();
   if (handler == NULL && in_debug_scope()) {
     // Send an empty command to the debugger if in a break to make JavaScript
     // run again if the debugger is closed.
     EnqueueCommandMessage(Vector<const uint16_t>::empty());
   }
 }
 
 void Debug::UpdateState() {
   bool is_active = message_handler_ != nullptr || !event_listener_.is_null() ||
-                   async_task_listener_ != nullptr;
+                   async_task_listener_ != nullptr ||
+                   compile_event_listener_ != nullptr;
   if (is_active || in_debug_scope()) {
     // Note that the debug context could have already been loaded to
     // bootstrap test cases.
     isolate_->compilation_cache()->Disable();
     is_active = Load();
   } else if (is_loaded()) {
     isolate_->compilation_cache()->Enable();
     Unload();
   }
   is_active_ = is_active;
@@ skipping 469 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8