[debugger api] remove legacy JSON debug protocol.

R=jgruber@chromium.org
BUG=v8:5530

Review-Url: https://codereview.chromium.org/2642253005
Cr-Original-Commit-Position: refs/heads/master@{#42543}
Committed: https://chromium.googlesource.com/v8/v8/+/e26a58e43c51a680a0a6363e0066886f4971a41f
Review-Url: https://codereview.chromium.org/2642253005
Cr-Commit-Position: refs/heads/master@{#42595}

include/v8-debug.h

@@ -116,9 +116,7 @@ class V8_EXPORT Debug {
     virtual Local<Value> GetCallbackData() const = 0;
 
     /**
-     * Client data passed to DebugBreakForCommand function. The
-     * debugger takes ownership of the data and will delete it even if
-     * there is no message handler.
+     * This is now a dummy that returns nullptr.
      */
     virtual ClientData* GetClientData() const = 0;
 
@@ -132,23 +130,18 @@ class V8_EXPORT Debug {
    *
    * \param event_details object providing information about the debug event
    *
-   * A EventCallback2 does not take possession of the event data,
+   * A EventCallback does not take possession of the event data,
    * and must not rely on the data persisting after the handler returns.
    */
   typedef void (*EventCallback)(const EventDetails& event_details);
 
   /**
-   * Debug message callback function.
-   *
-   * \param message the debug message handler message object
-   *
-   * A MessageHandler does not take possession of the message data,
-   * and must not rely on the data persisting after the handler returns.
+   * This is now a no-op.
    */
   typedef void (*MessageHandler)(const Message& message);
 
   /**
-   * Callback function for the host to ensure debug messages are processed.
+   * This is now a no-op.
    */
   typedef void (*DebugMessageDispatchHandler)();
 
@@ -167,11 +160,12 @@ class V8_EXPORT Debug {
   V8_DEPRECATED("No longer supported",
                 static bool CheckDebugBreak(Isolate* isolate));
 
-  // Message based interface. The message protocol is JSON.
+  // This is now a no-op.
   V8_DEPRECATED("No longer supported",
                 static void SetMessageHandler(Isolate* isolate,
                                               MessageHandler handler));
 
+  // This is now a no-op.
   V8_DEPRECATED("No longer supported",
                 static void SendCommand(Isolate* isolate,
                                         const uint16_t* command, int length,
@@ -207,37 +201,7 @@ class V8_EXPORT Debug {
                 static MaybeLocal<Value> GetMirror(Local<Context> context,
                                                    v8::Local<v8::Value> obj));
 
-  /**
-   * Makes V8 process all pending debug messages.
-   *
-   * From V8 point of view all debug messages come asynchronously (e.g. from
-   * remote debugger) but they all must be handled synchronously: V8 cannot
-   * do 2 things at one time so normal script execution must be interrupted
-   * for a while.
-   *
-   * Generally when message arrives V8 may be in one of 3 states:
-   * 1. V8 is running script; V8 will automatically interrupt and process all
-   * pending messages;
-   * 2. V8 is suspended on debug breakpoint; in this state V8 is dedicated
-   * to reading and processing debug messages;
-   * 3. V8 is not running at all or has called some long-working C++ function;
-   * by default it means that processing of all debug messages will be deferred
-   * until V8 gets control again; however, embedding application may improve
-   * this by manually calling this method.
-   *
-   * Technically this method in many senses is equivalent to executing empty
-   * script:
-   * 1. It does nothing except for processing all pending debug messages.
-   * 2. It should be invoked with the same precautions and from the same context
-   * as V8 script would be invoked from, because:
-   *   a. with "evaluate" command it can do whatever normal script can do,
-   *   including all native calls;
-   *   b. no other thread should call V8 while this method is running
-   *   (v8::Locker may be used here).
-   *
-   * "Evaluate" debug command behavior currently is not specified in scope
-   * of this method.
-   */
+  // This is now a no-op.
   V8_DEPRECATED("No longer supported",
                 static void ProcessDebugMessages(Isolate* isolate));
 

src/api.cc

@@ -8895,24 +8895,11 @@ bool Debug::CheckDebugBreak(Isolate* isolate) {
   return internal_isolate->stack_guard()->CheckDebugBreak();
 }
 
-
 void Debug::SetMessageHandler(Isolate* isolate,
-                              v8::Debug::MessageHandler handler) {
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  ENTER_V8(i_isolate);
-  i_isolate->debug()->SetMessageHandler(handler);
-}
-
-
-void Debug::SendCommand(Isolate* isolate,
-                        const uint16_t* command,
-                        int length,
-                        ClientData* client_data) {
-  i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  internal_isolate->debug()->EnqueueCommandMessage(
-      i::Vector<const uint16_t>(command, length), client_data);
-}
+                              v8::Debug::MessageHandler handler) {}
 
+void Debug::SendCommand(Isolate* isolate, const uint16_t* command, int length,
+                        ClientData* client_data) {}
 
 MaybeLocal<Value> Debug::Call(Local<Context> context,
                               v8::Local<v8::Function> fun,
@@ -8953,10 +8940,7 @@ MaybeLocal<Value> Debug::GetMirror(Local<Context> context,
   RETURN_ESCAPED(result);
 }
 
-void Debug::ProcessDebugMessages(Isolate* isolate) {
-  reinterpret_cast<i::Isolate*>(isolate)->debug()->ProcessDebugMessages(true);
-}
-
+void Debug::ProcessDebugMessages(Isolate* isolate) {}
 
 Local<Context> Debug::GetDebugContext(Isolate* isolate) {
   return debug::GetDebugContext(isolate);

src/debug/debug.h

@@ -244,62 +244,17 @@ class DebugInfoListNode {
   DebugInfoListNode* next_;
 };
 
-// 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::Local<v8::Object> GetExecutionState() const;
-  virtual v8::Local<v8::Object> GetEventData() const;
-  virtual v8::Local<v8::String> GetJSON() const;
-  virtual v8::Local<v8::Context> GetEventContext() const;
-  virtual v8::Debug::ClientData* GetClientData() const;
-  virtual v8::Isolate* GetIsolate() 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.
-};
-
 // Details of the debug event delivered to the debug event listener.
 class EventDetailsImpl : public v8::Debug::EventDetails {
  public:
-  EventDetailsImpl(DebugEvent event,
-                   Handle<JSObject> exec_state,
-                   Handle<JSObject> event_data,
-                   Handle<Object> callback_data,
-                   v8::Debug::ClientData* client_data);
+  EventDetailsImpl(DebugEvent event, Handle<JSObject> exec_state,
+                   Handle<JSObject> event_data, Handle<Object> callback_data);
   virtual DebugEvent GetEvent() const;
   virtual v8::Local<v8::Object> GetExecutionState() const;
   virtual v8::Local<v8::Object> GetEventData() const;
   virtual v8::Local<v8::Context> GetEventContext() const;
   virtual v8::Local<v8::Value> GetCallbackData() const;
-  virtual v8::Debug::ClientData* GetClientData() const;
+  virtual v8::Debug::ClientData* GetClientData() const { return nullptr; }
   virtual v8::Isolate* GetIsolate() const;
 
  private:
@@ -308,70 +263,8 @@ class EventDetailsImpl : public v8::Debug::EventDetails {
   Handle<JSObject> event_data_;         // Data associated with the event.
   Handle<Object> callback_data_;        // User data passed with the callback
                                         // when it was registered.
-  v8::Debug::ClientData* client_data_;  // Data passed to DebugBreakForCommand.
 };
 
-// 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
-// handler.
-class CommandMessage {
- public:
-  static CommandMessage New(const Vector<uint16_t>& command,
-                            v8::Debug::ClientData* data);
-  CommandMessage();
-
-  // Deletes user data and disposes of the text.
-  void Dispose();
-  Vector<uint16_t> text() const { return text_; }
-  v8::Debug::ClientData* client_data() const { return client_data_; }
-
- private:
-  CommandMessage(const Vector<uint16_t>& text, v8::Debug::ClientData* data);
-
-  Vector<uint16_t> text_;
-  v8::Debug::ClientData* client_data_;
-};
-
-// A Queue of CommandMessage objects.  A thread-safe version is
-// LockingCommandMessageQueue, based on this class.
-class CommandMessageQueue BASE_EMBEDDED {
- public:
-  explicit CommandMessageQueue(int size);
-  ~CommandMessageQueue();
-  bool IsEmpty() const { return start_ == end_; }
-  CommandMessage Get();
-  void Put(const CommandMessage& message);
-  void Clear() { start_ = end_ = 0; }  // Queue is empty after Clear().
-
- private:
-  // Doubles the size of the message queue, and copies the messages.
-  void Expand();
-
-  CommandMessage* messages_;
-  int start_;
-  int end_;
-  int size_;  // The size of the queue buffer.  Queue can hold size-1 messages.
-};
-
-// LockingCommandMessageQueue is a thread-safe circular buffer of CommandMessage
-// messages.  The message data is not managed by LockingCommandMessageQueue.
-// Pointers to the data are passed in and out. Implemented by adding a
-// Mutex to CommandMessageQueue.  Includes logging of all puts and gets.
-class LockingCommandMessageQueue BASE_EMBEDDED {
- public:
-  LockingCommandMessageQueue(Logger* logger, int size);
-  bool IsEmpty() const;
-  CommandMessage Get();
-  void Put(const CommandMessage& message);
-  void Clear();
-
- private:
-  Logger* logger_;
-  CommandMessageQueue queue_;
-  mutable base::Mutex mutex_;
-  DISALLOW_COPY_AND_ASSIGN(LockingCommandMessageQueue);
-};
 
 class DebugFeatureTracker {
  public:
@@ -405,7 +298,7 @@ class DebugFeatureTracker {
 class Debug {
  public:
   // Debug event triggers.
-  void OnDebugBreak(Handle<Object> break_points_hit, bool auto_continue);
+  void OnDebugBreak(Handle<Object> break_points_hit);
 
   void OnThrow(Handle<Object> exception);
   void OnPromiseReject(Handle<Object> promise, Handle<Object> value);
@@ -415,14 +308,10 @@ class Debug {
 
   // API facing.
   void SetEventListener(Handle<Object> callback, Handle<Object> data);
-  void SetMessageHandler(v8::Debug::MessageHandler handler);
-  void EnqueueCommandMessage(Vector<const uint16_t> command,
-                             v8::Debug::ClientData* client_data = NULL);
   MUST_USE_RESULT MaybeHandle<Object> Call(Handle<Object> fun,
                                            Handle<Object> data);
   Handle<Context> GetDebugContext();
   void HandleDebugBreak();
-  void ProcessDebugMessages(bool debug_command_only);
 
   // Internal logic
   bool Load();
@@ -579,8 +468,6 @@ class Debug {
     thread_local_.break_id_ = ++thread_local_.break_count_;
   }
 
-  // Check whether there are commands in the command queue.
-  inline bool has_commands() const { return !command_queue_.IsEmpty(); }
   inline bool ignore_events() const {
     return is_suppressed_ || !is_active_ || isolate_->needs_side_effect_check();
   }
@@ -604,8 +491,7 @@ class Debug {
   // is presented. Other clients can install JavaScript event listener
   // (e.g. some of NodeJS module).
   bool non_inspector_listener_exists() const {
-    return message_handler_ != nullptr ||
-           (!event_listener_.is_null() && !event_listener_->IsForeign());
+    return !event_listener_.is_null() && !event_listener_->IsForeign();
   }
 
   void OnException(Handle<Object> exception, Handle<Object> promise);
@@ -626,16 +512,8 @@ class Debug {
   // Mirror cache handling.
   void ClearMirrorCache();
 
-  void CallEventCallback(v8::DebugEvent event,
-                         Handle<Object> exec_state,
-                         Handle<Object> event_data,
-                         v8::Debug::ClientData* client_data);
   void ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script);
-  void ProcessDebugEvent(v8::DebugEvent event, Handle<JSObject> event_data,
-                         bool auto_continue);
-  void NotifyMessageHandler(v8::DebugEvent event, Handle<JSObject> exec_state,
-                            Handle<JSObject> event_data, bool auto_continue);
-  void InvokeMessageHandler(MessageImpl message);
+  void ProcessDebugEvent(v8::DebugEvent event, Handle<JSObject> event_data);
 
   // Find the closest source position for a break point for a given position.
   int FindBreakablePosition(Handle<DebugInfo> debug_info, int source_position,
@@ -676,14 +554,8 @@ class Debug {
   Handle<Object> event_listener_;
   Handle<Object> event_listener_data_;
 
-  v8::Debug::MessageHandler message_handler_;
-
   debug::DebugEventListener* debug_event_listener_ = nullptr;
 
-  static const int kQueueInitialSize = 4;
-  base::Semaphore command_received_;  // Signaled for each command received.
-  LockingCommandMessageQueue command_queue_;
-
   // Debugger is active, i.e. there is a debug event listener attached.
   bool is_active_;
   // Debugger needs to be notified on every new function call.

src/execution.cc

@@ -469,7 +469,7 @@ Object* StackGuard::HandleInterrupts() {
     isolate_->heap()->HandleGCRequest();
   }
 
-  if (CheckDebugBreak() || CheckDebugCommand()) {
+  if (CheckDebugBreak()) {
     isolate_->debug()->HandleDebugBreak();
   }
 

src/execution.h

@@ -86,12 +86,11 @@ class StackGuard final {
 
 #define INTERRUPT_LIST(V)                       \
   V(DEBUGBREAK, DebugBreak, 0)                  \
-  V(DEBUGCOMMAND, DebugCommand, 1)              \
-  V(TERMINATE_EXECUTION, TerminateExecution, 2) \
-  V(GC_REQUEST, GC, 3)                          \
-  V(INSTALL_CODE, InstallCode, 4)               \
-  V(API_INTERRUPT, ApiInterrupt, 5)             \
-  V(DEOPT_MARKED_ALLOCATION_SITES, DeoptMarkedAllocationSites, 6)
+  V(TERMINATE_EXECUTION, TerminateExecution, 1) \
+  V(GC_REQUEST, GC, 2)                          \
+  V(INSTALL_CODE, InstallCode, 3)               \
+  V(API_INTERRUPT, ApiInterrupt, 4)             \
+  V(DEOPT_MARKED_ALLOCATION_SITES, DeoptMarkedAllocationSites, 5)
 
 #define V(NAME, Name, id)                                          \
   inline bool Check##Name() { return CheckInterrupt(NAME); }  \

src/log.cc

@@ -1249,28 +1249,6 @@ void Logger::HeapSampleItemEvent(const char* type, int number, int bytes) {
 }
 
 
-void Logger::DebugTag(const char* call_site_tag) {
-  if (!log_->IsEnabled() || !FLAG_log) return;
-  Log::MessageBuilder msg(log_);
-  msg.Append("debug-tag,%s", call_site_tag);
-  msg.WriteToLogFile();
-}
-
-
-void Logger::DebugEvent(const char* event_type, Vector<uint16_t> parameter) {
-  if (!log_->IsEnabled() || !FLAG_log) return;
-  StringBuilder s(parameter.length() + 1);
-  for (int i = 0; i < parameter.length(); ++i) {
-    s.AddCharacter(static_cast<char>(parameter[i]));
-  }
-  char* parameter_string = s.Finalize();
-  Log::MessageBuilder msg(log_);
-  msg.Append("debug-queue-event,%s,%15.3f,%s", event_type,
-             base::OS::TimeCurrentMillis(), parameter_string);
-  DeleteArray(parameter_string);
-  msg.WriteToLogFile();
-}
-
 void Logger::RuntimeCallTimerEvent() {
   RuntimeCallStats* stats = isolate_->counters()->runtime_call_stats();
   RuntimeCallTimer* timer = stats->current_timer();

src/log.h

@@ -136,12 +136,6 @@ class Logger : public CodeEventListener {
   // object.
   void SuspectReadEvent(Name* name, Object* obj);
 
-  // Emits an event when a message is put on or read from a debugging queue.
-  // DebugTag lets us put a call-site specific label on the event.
-  void DebugTag(const char* call_site_tag);
-  void DebugEvent(const char* event_type, Vector<uint16_t> parameter);
-
-
   // ==== Events logged by --log-api. ====
   void ApiSecurityCheck();
   void ApiNamedPropertyAccess(const char* tag, JSObject* holder, Object* name);

src/wasm/wasm-debug.cc

@@ -178,7 +178,7 @@ class InterpreterHandle {
           hit_breakpoints.ToHandleChecked());
     }
 
-    isolate_->debug()->OnDebugBreak(hit_breakpoints_js, false);
+    isolate_->debug()->OnDebugBreak(hit_breakpoints_js);
   }
 
   int GetTopPosition(Handle<WasmCompiledModule> compiled_module) {

test/cctest/wasm/test-wasm-breakpoints.cc

@@ -55,12 +55,14 @@ class BreakHandler {
  public:
   explicit BreakHandler(Isolate* isolate) : isolate_(isolate) {
     current_handler = this;
-    isolate->debug()->SetMessageHandler(&HandleMessage);
+    v8::Debug::SetDebugEventListener(reinterpret_cast<v8::Isolate*>(isolate),
+                                     DebugEventListener);
   }
   ~BreakHandler() {
     CHECK_EQ(this, current_handler);
     current_handler = nullptr;
-    isolate_->debug()->SetMessageHandler(nullptr);
+    v8::Debug::SetDebugEventListener(reinterpret_cast<v8::Isolate*>(isolate_),
+                                     nullptr);
   }
 
   int count() const { return count_; }
@@ -71,25 +73,14 @@ class BreakHandler {
 
   static BreakHandler* current_handler;
 
-  static void HandleMessage(const v8::Debug::Message& message) {
-    // Ignore responses.
-    if (!message.IsEvent()) return;
-    // Ignore everything except break events.
-    if (message.GetEvent() != v8::DebugEvent::Break) return;
+  static void DebugEventListener(const v8::Debug::EventDetails& event_details) {
+    if (event_details.GetEvent() != v8::DebugEvent::Break) return;
 
     printf("break!\n");
     CHECK_NOT_NULL(current_handler);
     current_handler->count_ += 1;
     // Don't run into an endless loop.
     CHECK_GT(100, current_handler->count_);
-
-    const char command[] = "{\"type\":\"request\", \"command\":\"continue\"}";
-    uint16_t command_u16[arraysize(command) - 1];
-    for (unsigned i = 0; i < arraysize(command) - 1; ++i) {
-      command_u16[i] = command[i];
-    }
-    current_handler->isolate_->debug()->EnqueueCommandMessage(
-        ArrayVector(command_u16), message.GetClientData());
   }
 };