Re-submit http://codereview.chromium.org/99122 after fixing compilation issues.

TBR=yurys@chromium.org
Review URL: http://codereview.chromium.org/100155

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1813 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8-debug.h

@@ -91,6 +91,57 @@ class EXPORT Debug {
   };
 
 
+  /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Handle<Object> GetExecutionState() const = 0;
+    virtual Handle<Object> GetEventData() const = 0;
+	
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Handle<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in it's own context which is entered at this point.
+     */
+    virtual Handle<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual ~Message() {}
+  };
+  
+
   /**
    * Debug event callback function.
    *
@@ -101,26 +152,22 @@ class EXPORT Debug {
    * \param data value passed by the user to SetDebugEventListener
    */
   typedef void (*EventCallback)(DebugEvent event,
-                                     Handle<Object> exec_state,
-                                     Handle<Object> event_data,
-                                     Handle<Value> data);
+                                Handle<Object> exec_state,
+                                Handle<Object> event_data,
+                                Handle<Value> data);
 
 
   /**
    * Debug message callback function.
    *
-   * \param message the debug message
+   * \param message the debug message handler message object
    * \param length length of the message
    * \param data the data value passed when registering the message handler
-   * \param client_data the data value passed into Debug::SendCommand along
-   *     with the request that led to the message or NULL if the message is an
-   *     asynchronous event. The debugger takes ownership of the data and will
-   *     delete it before dying even if there is no message handler.
+
    * A MessageHandler does not take posession of the message string,
    * and must not rely on the data persisting after the handler returns.
    */
-  typedef void (*MessageHandler)(const uint16_t* message, int length,
-                                      ClientData* client_data);
+  typedef void (*MessageHandler)(const Message& message);
 
   /**
    * Debug host dispatch callback function.

src/debug-agent.cc

@@ -34,9 +34,8 @@ namespace v8 { namespace internal {
 
 // Public V8 debugger API message handler function. This function just delegates
 // to the debugger agent through it's data parameter.
-void DebuggerAgentMessageHandler(const uint16_t* message, int length,
-                                 v8::Debug::ClientData* client_data) {
-  DebuggerAgent::instance_->DebuggerMessage(message, length);
+void DebuggerAgentMessageHandler(const v8::Debug::Message& message) {
+  DebuggerAgent::instance_->DebuggerMessage(message);
 }
 
 // static
@@ -125,13 +124,14 @@ void DebuggerAgent::CloseSession() {
 }
 
 
-void DebuggerAgent::DebuggerMessage(const uint16_t* message, int length) {
+void DebuggerAgent::DebuggerMessage(const v8::Debug::Message& message) {
   ScopedLock with(session_access_);
 
   // Forward the message handling to the session.
   if (session_ != NULL) {
-    session_->DebuggerMessage(Vector<uint16_t>(const_cast<uint16_t*>(message),
-                              length));
+    v8::String::Value val(message.GetJSON());
+    session_->DebuggerMessage(Vector<uint16_t>(const_cast<uint16_t*>(*val),
+                              val.length()));
   }
 }
 

src/debug-agent.h

@@ -60,7 +60,7 @@ class DebuggerAgent: public Thread {
  private:
   void Run();
   void CreateSession(Socket* socket);
-  void DebuggerMessage(const uint16_t* message, int length);
+  void DebuggerMessage(const v8::Debug::Message& message);
   void CloseSession();
   void OnSessionClosed(DebuggerAgentSession* session);
 
@@ -75,8 +75,7 @@ class DebuggerAgent: public Thread {
   static DebuggerAgent* instance_;
 
   friend class DebuggerAgentSession;
-  friend void DebuggerAgentMessageHandler(const uint16_t* message, int length,
-                                          v8::Debug::ClientData* client_data);
+  friend void DebuggerAgentMessageHandler(const v8::Debug::Message& message);
 
   DISALLOW_COPY_AND_ASSIGN(DebuggerAgent);
 };

src/debug.cc

@@ -41,6 +41,8 @@
 #include "stub-cache.h"
 #include "log.h"
 
+#include "../include/v8-debug.h"
+
 namespace v8 { namespace internal {
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
@@ -1552,8 +1554,8 @@ void Debugger::OnException(Handle<Object> exception, bool uncaught) {
     return;
   }
 
-  // Process debug event
-  ProcessDebugEvent(v8::Exception, event_data, false);
+  // Process debug event.
+  ProcessDebugEvent(v8::Exception, Handle<JSObject>::cast(event_data), false);
   // Return to continue execution from where the exception was thrown.
 }
 
@@ -1584,8 +1586,10 @@ void Debugger::OnDebugBreak(Handle<Object> break_points_hit,
     return;
   }
 
-  // Process debug event
-  ProcessDebugEvent(v8::Break, event_data, auto_continue);
+  // Process debug event.
+  ProcessDebugEvent(v8::Break,
+                    Handle<JSObject>::cast(event_data),
+                    auto_continue);
 }
 
 
@@ -1609,8 +1613,10 @@ void Debugger::OnBeforeCompile(Handle<Script> script) {
     return;
   }
 
-  // Process debug event
-  ProcessDebugEvent(v8::BeforeCompile, event_data, true);
+  // Process debug event.
+  ProcessDebugEvent(v8::BeforeCompile,
+                    Handle<JSObject>::cast(event_data),
+                    true);
 }
 
 
@@ -1670,8 +1676,10 @@ void Debugger::OnAfterCompile(Handle<Script> script, Handle<JSFunction> fun) {
   if (caught_exception) {
     return;
   }
-  // Process debug event
-  ProcessDebugEvent(v8::AfterCompile, event_data, true);
+  // Process debug event.
+  ProcessDebugEvent(v8::AfterCompile,
+                    Handle<JSObject>::cast(event_data),
+                    true);
 }
 
 
@@ -1696,12 +1704,12 @@ void Debugger::OnNewFunction(Handle<JSFunction> function) {
     return;
   }
   // Process debug event.
-  ProcessDebugEvent(v8::NewFunction, event_data, true);
+  ProcessDebugEvent(v8::NewFunction, Handle<JSObject>::cast(event_data), true);
 }
 
 
 void Debugger::ProcessDebugEvent(v8::DebugEvent event,
-                                 Handle<Object> event_data,
+                                 Handle<JSObject> event_data,
                                  bool auto_continue) {
   HandleScope scope;
 
@@ -1713,7 +1721,10 @@ void Debugger::ProcessDebugEvent(v8::DebugEvent event,
   }
   // First notify the message handler if any.
   if (message_handler_ != NULL) {
-    NotifyMessageHandler(event, exec_state, event_data, auto_continue);
+    NotifyMessageHandler(event,
+                         Handle<JSObject>::cast(exec_state),
+                         event_data,
+                         auto_continue);
   }
   // Notify registered debug event listener. This can be either a C or a
   // JavaScript function.
@@ -1725,7 +1736,7 @@ void Debugger::ProcessDebugEvent(v8::DebugEvent event,
             FUNCTION_CAST<v8::Debug::EventCallback>(callback_obj->proxy());
       callback(event,
                v8::Utils::ToLocal(Handle<JSObject>::cast(exec_state)),
-               v8::Utils::ToLocal(Handle<JSObject>::cast(event_data)),
+               v8::Utils::ToLocal(event_data),
                v8::Utils::ToLocal(Handle<Object>::cast(event_listener_data_)));
     } else {
       // JavaScript debug event listener.
@@ -1736,7 +1747,7 @@ void Debugger::ProcessDebugEvent(v8::DebugEvent event,
       const int argc = 4;
       Object** argv[argc] = { Handle<Object>(Smi::FromInt(event)).location(),
                               exec_state.location(),
-                              event_data.location(),
+                              Handle<Object>::cast(event_data).location(),
                               event_listener_data_.location() };
       Handle<Object> result = Execution::TryCall(fun, Top::global(),
                                                  argc, argv, &caught_exception);
@@ -1766,8 +1777,8 @@ void Debugger::UnloadDebugger() {
 
 
 void Debugger::NotifyMessageHandler(v8::DebugEvent event,
-                                    Handle<Object> exec_state,
-                                    Handle<Object> event_data,
+                                    Handle<JSObject> exec_state,
+                                    Handle<JSObject> event_data,
                                     bool auto_continue) {
   HandleScope scope;
 
@@ -1802,7 +1813,12 @@ void Debugger::NotifyMessageHandler(v8::DebugEvent event,
   // Notify the debugger that a debug event has occurred unless auto continue is
   // active in which case no event is send.
   if (sendEventMessage) {
-    InvokeMessageHandlerWithEvent(event_data);
+    MessageImpl message = MessageImpl::NewEvent(
+        event,
+        auto_continue,
+        Handle<JSObject>::cast(exec_state),
+        Handle<JSObject>::cast(event_data));
+    InvokeMessageHandler(message);
   }
   if (auto_continue && !HasCommands()) {
     return;
@@ -1857,7 +1873,6 @@ void Debugger::NotifyMessageHandler(v8::DebugEvent event,
 
     request = v8::String::New(command.text().start(),
                               command.text().length());
-    command.text().Dispose();
     static const int kArgc = 1;
     v8::Handle<Value> argv[kArgc] = { request };
     v8::Local<v8::Value> response_val = fun->Call(cmd_processor, kArgc, argv);
@@ -1894,7 +1909,15 @@ void Debugger::NotifyMessageHandler(v8::DebugEvent event,
     }
 
     // Return the result.
-    InvokeMessageHandler(response, command.client_data());
+    MessageImpl message = MessageImpl::NewResponse(
+        event,
+        running,
+        Handle<JSObject>::cast(exec_state),
+        Handle<JSObject>::cast(event_data),
+        Handle<String>(Utils::OpenHandle(*response)),
+        command.client_data());
+    InvokeMessageHandler(message);
+    command.Dispose();
 
     // Return from debug event processing if either the VM is put into the
     // runnning state (through a continue command) or auto continue is active
@@ -1965,54 +1988,13 @@ void Debugger::SetHostDispatchHandler(v8::Debug::HostDispatchHandler handler,
 
 
 // Calls the registered debug message handler. This callback is part of the
-// public API. Messages are kept internally as Vector<uint16_t> strings, which
-// are allocated in various places and deallocated by the calling function
-// sometime after this call.
-void Debugger::InvokeMessageHandler(v8::Handle<v8::String> output,
-                                    v8::Debug::ClientData* data) {
+// public API.
+void Debugger::InvokeMessageHandler(MessageImpl message) {
   ScopedLock with(debugger_access_);
 
   if (message_handler_ != NULL) {
-    Vector<uint16_t> text = Vector<uint16_t>::New(output->Length());
-    output->Write(text.start(), 0, output->Length());
-
-    message_handler_(text.start(),
-                     text.length(),
-                     data);
-
-    text.Dispose();
-  }
-  delete data;
-}
-
-
-bool Debugger::InvokeMessageHandlerWithEvent(Handle<Object> event_data) {
-  v8::HandleScope scope;
-  // Call toJSONProtocol on the debug event object.
-  v8::Local<v8::Object> api_event_data =
-      v8::Utils::ToLocal(Handle<JSObject>::cast(event_data));
-  v8::Local<v8::String> fun_name = v8::String::New("toJSONProtocol");
-  v8::Local<v8::Function> fun =
-      v8::Function::Cast(*api_event_data->Get(fun_name));
-  v8::TryCatch try_catch;
-  v8::Local<v8::Value> json_event = *fun->Call(api_event_data, 0, NULL);
-  v8::Local<v8::String> json_event_string;
-  if (!try_catch.HasCaught()) {
-    if (!json_event->IsUndefined()) {
-      json_event_string = json_event->ToString();
-      if (FLAG_trace_debug_json) {
-        PrintLn(json_event_string);
-      }
-      InvokeMessageHandler(json_event_string,
-                           NULL /* no user data since there was no request */);
-    } else {
-      InvokeMessageHandler(v8::String::Empty(), NULL);
-    }
-  } else {
-    PrintLn(try_catch.Exception());
-    return false;
+    message_handler_(message);
   }
-  return true;
 }
 
 
@@ -2098,6 +2080,107 @@ void Debugger::StopAgent() {
 }
 
 
+MessageImpl MessageImpl::NewEvent(DebugEvent event,
+                                  bool running,
+                                  Handle<JSObject> exec_state,
+                                  Handle<JSObject> event_data) {
+  MessageImpl message(true, event, running,
+                      exec_state, event_data, Handle<String>(), NULL);
+  return message;
+}
+
+
+MessageImpl MessageImpl::NewResponse(DebugEvent event,
+                                     bool running,
+                                     Handle<JSObject> exec_state,
+                                     Handle<JSObject> event_data,
+                                     Handle<String> response_json,
+                                     v8::Debug::ClientData* client_data) {
+  MessageImpl message(false, event, running,
+                      exec_state, event_data, response_json, client_data);
+  return message;
+}
+
+
+MessageImpl::MessageImpl(bool is_event,
+                         DebugEvent event,
+                         bool running,
+                         Handle<JSObject> exec_state,
+                         Handle<JSObject> event_data,
+                         Handle<String> response_json,
+                         v8::Debug::ClientData* client_data)
+    : is_event_(is_event),
+      event_(event),
+      running_(running),
+      exec_state_(exec_state),
+      event_data_(event_data),
+      response_json_(response_json),
+      client_data_(client_data) {}
+
+
+bool MessageImpl::IsEvent() const {
+  return is_event_;
+}
+
+
+bool MessageImpl::IsResponse() const {
+  return !is_event_;
+}
+
+
+DebugEvent MessageImpl::GetEvent() const {
+  return event_;
+}
+
+
+bool MessageImpl::WillStartRunning() const {
+  return running_;
+}
+
+
+v8::Handle<v8::Object> MessageImpl::GetExecutionState() const {
+  return v8::Utils::ToLocal(exec_state_);
+}
+
+
+v8::Handle<v8::Object> MessageImpl::GetEventData() const {
+  return v8::Utils::ToLocal(event_data_);
+}
+
+
+v8::Handle<v8::String> MessageImpl::GetJSON() const {
+  v8::HandleScope scope;
+
+  if (IsEvent()) {
+    // Call toJSONProtocol on the debug event object.
+    Handle<Object> fun = GetProperty(event_data_, "toJSONProtocol");
+    if (!fun->IsJSFunction()) {
+      return v8::Handle<v8::String>();
+    }
+    bool caught_exception;
+    Handle<Object> json = Execution::TryCall(Handle<JSFunction>::cast(fun),
+                                             event_data_,
+                                             0, NULL, &caught_exception);
+    if (caught_exception || !json->IsString()) {
+      return v8::Handle<v8::String>();
+    }
+    return scope.Close(v8::Utils::ToLocal(Handle<String>::cast(json)));
+  } else {
+    return v8::Utils::ToLocal(response_json_);
+  }
+}
+
+
+v8::Handle<v8::Context> MessageImpl::GetEventContext() const {
+  return v8::Handle<v8::Context>();
+}
+
+
+v8::Debug::ClientData* MessageImpl::GetClientData() const {
+  return client_data_;
+}
+
+
 CommandMessage::CommandMessage() : text_(Vector<uint16_t>::empty()),
                                    client_data_(NULL) {
 }

src/debug.h

@@ -401,6 +401,54 @@ class Debug {
 };
 
 
+// Message delivered to the message handler callback. This is either a debugger
+// event or the response to a command.
+class MessageImpl: public v8::Debug::Message {
+ public:
+  // Create a message object for a debug event.
+  static MessageImpl NewEvent(DebugEvent event,
+                              bool running,
+                              Handle<JSObject> exec_state,
+                              Handle<JSObject> event_data);
+
+  // Create a message object for the response to a debug command.
+  static MessageImpl NewResponse(DebugEvent event,
+                                 bool running,
+                                 Handle<JSObject> exec_state,
+                                 Handle<JSObject> event_data,
+                                 Handle<String> response_json,
+                                 v8::Debug::ClientData* client_data);
+
+  // Implementation of interface v8::Debug::Message.
+  virtual bool IsEvent() const;
+  virtual bool IsResponse() const;
+  virtual DebugEvent GetEvent() const;
+  virtual bool WillStartRunning() const;
+  virtual v8::Handle<v8::Object> GetExecutionState() const;
+  virtual v8::Handle<v8::Object> GetEventData() const;
+  virtual v8::Handle<v8::String> GetJSON() const;
+  virtual v8::Handle<v8::Context> GetEventContext() const;
+  virtual v8::Debug::ClientData* GetClientData() const;
+
+ private:
+  MessageImpl(bool is_event,
+              DebugEvent event,
+              bool running,
+              Handle<JSObject> exec_state,
+              Handle<JSObject> event_data,
+              Handle<String> response_json,
+              v8::Debug::ClientData* client_data);
+
+  bool is_event_;  // Does this message represent a debug event?
+  DebugEvent event_;  // Debug event causing the break.
+  bool running_;  // Will the VM start running after this event?
+  Handle<JSObject> exec_state_;  // Current execution state.
+  Handle<JSObject> event_data_;  // Data associated with the event.
+  Handle<String> response_json_;  // Response JSON if message holds a response.
+  v8::Debug::ClientData* client_data_;  // Client data passed with the request.
+};
+
+
 // Message send by user to v8 debugger or debugger output message.
 // In addition to command text it may contain a pointer to some user data
 // which are expected to be passed along with the command reponse to message
@@ -491,11 +539,11 @@ class Debugger {
                            Handle<JSFunction> fun);
   static void OnNewFunction(Handle<JSFunction> fun);
   static void ProcessDebugEvent(v8::DebugEvent event,
-                                Handle<Object> event_data,
+                                Handle<JSObject> event_data,
                                 bool auto_continue);
   static void NotifyMessageHandler(v8::DebugEvent event,
-                                   Handle<Object> exec_state,
-                                   Handle<Object> event_data,
+                                   Handle<JSObject> exec_state,
+                                   Handle<JSObject> event_data,
                                    bool auto_continue);
   static void SetEventListener(Handle<Object> callback, Handle<Object> data);
   static void SetMessageHandler(v8::Debug::MessageHandler handler);
@@ -503,11 +551,7 @@ class Debugger {
                                      int period);
 
   // Invoke the message handler function.
-  static void InvokeMessageHandler(v8::Handle<v8::String> output,
-                                   v8::Debug::ClientData* data);
-
-  // Send the JSON message for a debug event.
-  static bool InvokeMessageHandlerWithEvent(Handle<Object> event_data);
+  static void InvokeMessageHandler(MessageImpl message);
 
   // Add a debugger command to the command queue.
   static void ProcessCommand(Vector<const uint16_t> command,

test/cctest/test-debug.cc

@@ -3427,10 +3427,10 @@ class MessageQueueDebuggerThread : public v8::internal::Thread {
   void Run();
 };
 
-static void MessageHandler(const uint16_t* message, int length,
-                           v8::Debug::ClientData* client_data) {
+static void MessageHandler(const v8::Debug::Message& message) {
   static char print_buffer[1000];
-  Utf16ToAscii(message, length, print_buffer);
+  v8::String::Value json(message.GetJSON());
+  Utf16ToAscii(*json, json.length(), print_buffer);
   if (IsBreakEventMessage(print_buffer)) {
     // Lets test script wait until break occurs to send commands.
     // Signals when a break is reported.
@@ -3612,10 +3612,8 @@ TEST(MessageQueueExpandAndDestroy) {
 
 static int handled_client_data_instances_count = 0;
 static void MessageHandlerCountingClientData(
-    const uint16_t* message,
-    int length,
-    v8::Debug::ClientData* client_data) {
-  if (client_data) {
+    const v8::Debug::Message& message) {
+  if (message.GetClientData() != NULL) {
     handled_client_data_instances_count++;
   }
 }
@@ -3691,10 +3689,10 @@ static v8::Handle<v8::Value> ThreadedAtBarrier1(const v8::Arguments& args) {
 }
 
 
-static void ThreadedMessageHandler(const uint16_t* message, int length,
-                                   v8::Debug::ClientData* client_data) {
+static void ThreadedMessageHandler(const v8::Debug::Message& message) {
   static char print_buffer[1000];
-  Utf16ToAscii(message, length, print_buffer);
+  v8::String::Value json(message.GetJSON());
+  Utf16ToAscii(*json, json.length(), print_buffer);
   if (IsBreakEventMessage(print_buffer)) {
     threaded_debugging_barriers.barrier_2.Wait();
   }
@@ -3788,11 +3786,10 @@ class BreakpointsDebuggerThread : public v8::internal::Thread {
 
 Barriers* breakpoints_barriers;
 
-static void BreakpointsMessageHandler(const uint16_t* message,
-                                      int length,
-                                      v8::Debug::ClientData* client_data) {
+static void BreakpointsMessageHandler(const v8::Debug::Message& message) {
   static char print_buffer[1000];
-  Utf16ToAscii(message, length, print_buffer);
+  v8::String::Value json(message.GetJSON());
+  Utf16ToAscii(*json, json.length(), print_buffer);
   printf("%s\n", print_buffer);
   fflush(stdout);
 
@@ -3935,9 +3932,7 @@ TEST(SetDebugEventListenerOnUninitializedVM) {
 }
 
 
-static void DummyMessageHandler(const uint16_t* message,
-                                int length,
-                                v8::Debug::ClientData* client_data) {
+static void DummyMessageHandler(const v8::Debug::Message& message) {
 }
 
 
@@ -4162,9 +4157,7 @@ TEST(DebuggerUnload) {
 
 // Debugger message handler which counts the number of times it is called.
 static int message_handler_hit_count = 0;
-static void MessageHandlerHitCount(const uint16_t* message,
-                                   int length,
-                                   v8::Debug::ClientData* client_data) {
+static void MessageHandlerHitCount(const v8::Debug::Message& message) {
   message_handler_hit_count++;
 
   const int kBufferSize = 1000;
@@ -4213,9 +4206,7 @@ TEST(DebuggerClearMessageHandler) {
 
 // Debugger message handler which clears the message handler while active.
 static void MessageHandlerClearingMessageHandler(
-    const uint16_t* message,
-    int length,
-    v8::Debug::ClientData* client_data) {
+    const v8::Debug::Message& message) {
   message_handler_hit_count++;
 
   // Clear debug message handler.
@@ -4262,11 +4253,10 @@ class HostDispatchDebuggerThread : public v8::internal::Thread {
 
 Barriers* host_dispatch_barriers;
 
-static void HostDispatchMessageHandler(const uint16_t* message,
-                                       int length,
-                                       v8::Debug::ClientData* client_data) {
+static void HostDispatchMessageHandler(const v8::Debug::Message& message) {
   static char print_buffer[1000];
-  Utf16ToAscii(message, length, print_buffer);
+  v8::String::Value json(message.GetJSON());
+  Utf16ToAscii(*json, json.length(), print_buffer);
   printf("%s\n", print_buffer);
   fflush(stdout);
 }