gdb/remote: Restore support for 'S' stop reply packet

[deliverable/binutils-gdb.git] / gdb / remote.c

diff --git a/gdb/remote.c b/gdb/remote.c
index 4a70ab3fb0d1b6c9f67a2619be2d8f3ee3884f58..9b73faf9a3459ef28dbc6789e552dc5abf54dae1 100644 (file)
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -7402,18 +7402,14 @@ Packet: '%s'\n"),
                     reported expedited registers.  */
                  if (event->ptid == null_ptid)
                    {
+                     /* If there is no thread-id information then leave
+                        the event->ptid as null_ptid.  Later in
+                        process_stop_reply we will pick a suitable
+                        thread.  */
                      const char *thr = strstr (p1 + 1, ";thread:");
                      if (thr != NULL)
                        event->ptid = read_ptid (thr + strlen (";thread:"),
                                                 NULL);
-                     else
-                       {
-                         /* Either the current thread hasn't changed,
-                            or the inferior is not multi-threaded.
-                            The event must be for the thread we last
-                            set as (or learned as being) current.  */
-                         event->ptid = event->rs->general_thread;
-                       }
                    }
 
                  if (rsa == NULL)
@@ -7668,10 +7664,35 @@ remote_target::process_stop_reply (struct stop_reply *stop_reply,
   *status = stop_reply->ws;
   ptid = stop_reply->ptid;
 
-  /* If no thread/process was reported by the stub, assume the current
-     inferior.  */
+  /* If no thread/process was reported by the stub then use the first
+     non-exited thread in the current target.  */
   if (ptid == null_ptid)
-    ptid = inferior_ptid;
+    {
+      for (thread_info *thr : all_non_exited_threads (this))
+       {
+         if (ptid != null_ptid)
+           {
+             static bool warned = false;
+
+             if (!warned)
+               {
+                 /* If you are seeing this warning then the remote target
+                    has multiple threads and either sent an 'S' stop
+                    packet, or a 'T' stop packet without a thread-id.  In
+                    both of these cases GDB is unable to know which thread
+                    just stopped and is now having to guess.  The correct
+                    action is to fix the remote target to send the correct
+                    packet (a 'T' packet and include a thread-id).  */
+                 warning (_("multi-threaded target stopped without sending "
+                            "a thread-id, using first non-exited thread"));
+                 warned = true;
+               }
+             break;
+           }
+         ptid = thr->ptid;
+       }
+      gdb_assert (ptid != null_ptid);
+    }
 
   if (status->kind != TARGET_WAITKIND_EXITED
       && status->kind != TARGET_WAITKIND_SIGNALLED