[PATCH 5/5] Add TARGET_WAITKIND_NO_RESUMED support to the RSP.

[Pedro Alves <palves@redhat.com>]

Makes gdb.threads/no-unwaited-for-left.exp pass.

WIP.
---
 gdb/gdbserver/remote-utils.c |  3 +++
 gdb/gdbserver/server.c       | 30 ++++++++++++++++++------------
 gdb/remote.c                 | 13 ++++++++++---
 3 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c
index 3b88995..f5acd12 100644
--- a/gdb/gdbserver/remote-utils.c
+++ b/gdb/gdbserver/remote-utils.c
@@ -1429,6 +1429,9 @@ prepare_resume_reply (char *buf, ptid_t ptid,
       else
 	sprintf (buf, "X%02x", status->value.sig);
       break;
+    case TARGET_WAITKIND_NO_RESUMED:
+      sprintf (buf, "N");
+      break;
     default:
       error ("unhandled waitkind");
       break;
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 0f50afe..e779793 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -2321,7 +2321,8 @@ resume (struct thread_resume *actions, size_t num_actions)
     {
       last_ptid = mywait (minus_one_ptid, &last_status, 0, 1);
 
-      if (last_status.kind == TARGET_WAITKIND_NO_RESUMED)
+      if (last_status.kind == TARGET_WAITKIND_NO_RESUMED
+	  && 0 /* XXX Check if GDB supports this.  */)
 	{
 	  /* No proper RSP support for this yet.  At least return
 	     error.  */
@@ -3847,6 +3848,18 @@ handle_serial_event (int err, gdb_client_data client_data)
   return 0;
 }
 
+static void
+push_stop_notification (ptid_t ptid, struct target_waitstatus *status)
+{
+  struct vstop_notif *vstop_notif
+    = xmalloc (sizeof (struct vstop_notif));
+
+  vstop_notif->status = *status;
+  vstop_notif->ptid = ptid;
+  /* Push Stop notification.  */
+  notif_push (&notif_stop, (struct notif_event *) vstop_notif);
+}
+
 /* Event-loop callback for target events.  */
 
 int
@@ -3860,7 +3873,9 @@ handle_target_event (int err, gdb_client_data client_data)
 
   if (last_status.kind == TARGET_WAITKIND_NO_RESUMED)
     {
-      /* No RSP support for this yet.  */
+      if (gdb_connected ()
+	  && 1 /* XXX Check here if GDB supports for this stop reply.  */)
+	push_stop_notification (null_ptid, &last_status);
     }
   else if (last_status.kind != TARGET_WAITKIND_IGNORE)
     {
@@ -3915,16 +3930,7 @@ handle_target_event (int err, gdb_client_data client_data)
 			  target_pid_to_str (last_ptid));
 	}
       else
-	{
-	  struct vstop_notif *vstop_notif
-	    = xmalloc (sizeof (struct vstop_notif));
-
-	  vstop_notif->status = last_status;
-	  vstop_notif->ptid = last_ptid;
-	  /* Push Stop notification.  */
-	  notif_push (&notif_stop,
-		      (struct notif_event *) vstop_notif);
-	}
+	push_stop_notification (last_ptid, &last_status);
     }
 
   /* Be sure to not change the selected inferior behind GDB's back.
diff --git a/gdb/remote.c b/gdb/remote.c
index d886929..94552a3 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -5838,6 +5838,10 @@ Packet: '%s'\n"),
 	event->ptid = pid_to_ptid (pid);
       }
       break;
+    case 'N':
+      event->ws.kind = TARGET_WAITKIND_NO_RESUMED;
+      event->ptid = minus_one_ptid;
+      break;
     }
 
   if (non_stop && ptid_equal (event->ptid, null_ptid))
@@ -5939,7 +5943,8 @@ process_stop_reply (struct stop_reply *stop_reply,
     ptid = inferior_ptid;
 
   if (status->kind != TARGET_WAITKIND_EXITED
-      && status->kind != TARGET_WAITKIND_SIGNALLED)
+      && status->kind != TARGET_WAITKIND_SIGNALLED
+      && status->kind != TARGET_WAITKIND_NO_RESUMED)
     {
       struct remote_state *rs = get_remote_state ();
 
@@ -6108,7 +6113,7 @@ remote_wait_as (ptid_t ptid, struct target_waitstatus *status, int options)
       remote_fileio_request (buf, rs->ctrlc_pending_p);
       rs->ctrlc_pending_p = 0;
       break;
-    case 'T': case 'S': case 'X': case 'W':
+    case 'N': case 'T': case 'S': case 'X': case 'W':
       {
 	struct stop_reply *stop_reply
 	  = (struct stop_reply *) remote_notif_parse (&notif_client_stop,
@@ -6152,7 +6157,9 @@ remote_wait_as (ptid_t ptid, struct target_waitstatus *status, int options)
       break;
     }
 
-  if (status->kind == TARGET_WAITKIND_IGNORE)
+  if (status->kind == TARGET_WAITKIND_NO_RESUMED)
+    return minus_one_ptid;
+  else if (status->kind == TARGET_WAITKIND_IGNORE)
     {
       /* Nothing interesting happened.  If we're doing a non-blocking
 	 poll, we're done.  Otherwise, go back to waiting.  */
-- 
1.7.11.7