remove node::CheckBreak in favor of using the v8 debugger js object

lib/module.js

@@ -420,7 +420,9 @@ Module.prototype._compile = function (content, filename) {
                   + "\n});";
 
       var compiledWrapper = process.compile(wrapper, filename);
-      if (filename === process.argv[1]) process.checkBreak();
+      if (filename === process.argv[1] && global.v8debug) {
+        global.v8debug.Debug.setBreakPoint(compiledWrapper, 0, 0);
+      }
       compiledWrapper.apply(self.exports, [self.exports, require, self, filename, dirname]);
     } else {
       self.exports = content;

src/node.cc

@@ -1426,7 +1426,6 @@ void FatalException(TryCatch &try_catch) {
 
 
 static ev_async debug_watcher;
-volatile static bool debugger_msg_pending = false;
 
 static void DebugMessageCallback(EV_P_ ev_async *watcher, int revents) {
   HandleScope scope;
@@ -1441,48 +1440,13 @@ static void DebugMessageDispatch(void) {
 
   // Send a signal to our main thread saying that it should enter V8 to
   // handle the message.
-  debugger_msg_pending = true;
   ev_async_send(EV_DEFAULT_UC_ &debug_watcher);
 }
 
-static Handle<Value> CheckBreak(const Arguments& args) {
-  HandleScope scope;
-  assert(args.Length() == 0);
-
-  // TODO FIXME This function is a hack to wait until V8 is ready to accept
-  // commands. There seems to be a bug in EnableAgent( _ , _ , true) which
-  // makes it unusable here. Ideally we'd be able to bind EnableAgent and
-  // get it to halt until Eclipse connects.
-
-  if (!debug_wait_connect)
-    return Undefined();
-
-  printf("Waiting for remote debugger connection...\n");
-
-  const int halfSecond = 50;
-  const int tenMs=10000;
-  debugger_msg_pending = false;
-  for (;;) {
-    if (debugger_msg_pending) {
-      Debug::DebugBreak();
-      Debug::ProcessDebugMessages();
-      debugger_msg_pending = false;
-
-      // wait for 500 msec of silence from remote debugger
-      int cnt = halfSecond;
-        while (cnt --) {
-        debugger_msg_pending = false;
-        usleep(tenMs);
-        if (debugger_msg_pending) {
-          debugger_msg_pending = false;
-          cnt = halfSecond;
-        }
-      }
-      break;
-    }
-    usleep(tenMs);
-  }
-  return Undefined();
+static void DebugBreakMessageHandler(const Debug::Message& message) {
+  // do nothing with debug messages.
+  // The message handler will get changed by DebuggerAgent::CreateSession in
+  // debug-agent.cc of v8/src when a new session is created
 }
 
 Persistent<Object> binding_cache;
@@ -1626,7 +1590,6 @@ static void Load(int argc, char *argv[]) {
   NODE_SET_METHOD(process, "dlopen", DLOpen);
   NODE_SET_METHOD(process, "kill", Kill);
   NODE_SET_METHOD(process, "memoryUsage", MemoryUsage);
-  NODE_SET_METHOD(process, "checkBreak", CheckBreak);
 
   NODE_SET_METHOD(process, "binding", Binding);
 
@@ -1775,7 +1738,20 @@ int main(int argc, char *argv[]) {
   node::ParseArgs(&argc, argv);
   // Parse the rest of the args (up to the 'option_end_index' (where '--' was
   // in the command line))
-  V8::SetFlagsFromCommandLine(&node::option_end_index, argv, false);
+  int v8argc = node::option_end_index;
+  char **v8argv = argv;
+
+  if (node::debug_wait_connect) {
+    // v8argv is a copy of argv up to the script file argument +2 if --debug-brk
+    // to expose the v8 debugger js object so that module.js can set
+    // a breakpoint on the first line of the startup script
+    v8argc += 2;
+    v8argv = new char*[v8argc];
+    memcpy(v8argv, argv, sizeof(argv) * node::option_end_index);
+    v8argv[node::option_end_index] = const_cast<char*>("--expose_debug_as");
+    v8argv[node::option_end_index + 1] = const_cast<char*>("v8debug");
+  }
+  V8::SetFlagsFromCommandLine(&v8argc, v8argv, false);
 
   // Ignore SIGPIPE
   struct sigaction sa;
@@ -1851,6 +1827,13 @@ int main(int argc, char *argv[]) {
 
     // Start the debug thread and it's associated TCP server on port 5858.
     bool r = Debug::EnableAgent("node " NODE_VERSION, node::debug_port);
+    if (node::debug_wait_connect) {
+      // Set up an empty handler so v8 will not continue until a debugger
+      // attaches. This is the same behavior as Debug::EnableAgent(_,_,true)
+      // except we don't break at the beginning of the script.
+      // see Debugger::StartAgent in debug.cc of v8/src
+      Debug::SetMessageHandler2(node::DebugBreakMessageHandler);
+    }
 
     // Crappy check that everything went well. FIXME
     assert(r);