gdb, record: notify frame change on 'record stop' when selected thread moves

As a side effect of the 'record stop' command, threads may move to the end
of their execution history if they had been replaying.

When using CLI or TUI, there is no indication of that move for the
selected thread.

Notify about the frame change for the selected thread.  This makes CLI
print the selected frame and TUI update their view.

Add a note to the MI record-stopped event.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>

gdb/doc/gdb.texinfo

@@ -32566,6 +32566,9 @@ method in use supports multiple recording formats, @var{format} will be present
 and contain the currently used format.  @xref{Process Record and Replay},
 for existing method and format values.
 
+If recording was stopped for the btrace method, threads move to the
+end of their execution history.
+
 @item =cmd-param-changed,param=@var{param},value=@var{value}
 Reports that a parameter of the command @code{set @var{param}} is
 changed to @var{value}.  In the multi-word @code{set} command,

gdb/record-btrace.c

@@ -80,7 +80,7 @@ public:
 
   enum record_method record_method (ptid_t ptid) override;
 
-  void stop_recording () override;
+  bool stop_recording () override;
   void info_record () override;
 
   void insn_history (int size, gdb_disassembly_flags flags) override;
@@ -408,17 +408,20 @@ record_btrace_target_open (const char *args, int from_tty)
 
 /* The stop_recording method of target record-btrace.  */
 
-void
+bool
 record_btrace_target::stop_recording ()
 {
   DEBUG ("stop recording");
 
+  bool is_replaying = record_is_replaying (inferior_ptid);
   record_stop_replaying ();
   record_btrace_auto_disable ();
 
   for (thread_info &tp : current_inferior ()->non_exited_threads ())
     if (tp.btrace.target != NULL)
       btrace_disable (&tp);
+
+  return is_replaying;
 }
 
 /* The disconnect method of target record-btrace.  */

gdb/record.c

@@ -151,12 +151,12 @@ record_read_memory (struct gdbarch *gdbarch,
 
 /* Stop recording.  */
 
-static void
+static bool
 record_stop (struct target_ops *t)
 {
   DEBUG ("stop %s", t->shortname ());
 
-  t->stop_recording ();
+  return t->stop_recording ();
 }
 
 /* Unpush the record target.  */
@@ -178,7 +178,7 @@ record_disconnect (struct target_ops *t, const char *args, int from_tty)
 
   DEBUG ("disconnect %s", t->shortname ());
 
-  record_stop (t);
+  (void) record_stop (t);
   record_unpush (t);
 
   target_disconnect (args, from_tty);
@@ -193,7 +193,7 @@ record_detach (struct target_ops *t, inferior *inf, int from_tty)
 
   DEBUG ("detach %s", t->shortname ());
 
-  record_stop (t);
+  (void) record_stop (t);
   record_unpush (t);
 
   target_detach (inf, from_tty);
@@ -305,17 +305,18 @@ cmd_record_delete (const char *args, int from_tty)
 static void
 cmd_record_stop (const char *args, int from_tty)
 {
-  struct target_ops *t;
-
-  t = require_record_target ();
-
-  record_stop (t);
+  struct target_ops *t = require_record_target ();
+  bool thread_moved = record_stop (t);
   record_unpush (t);
 
   gdb_printf (_("Process record is stopped and all execution "
 		"logs are deleted.\n"));
 
   interps_notify_record_changed (current_inferior (), 0, NULL, NULL);
+
+  /* INFERIOR_PTID may have moved when we stopped recording.  */
+  if (thread_moved)
+    notify_user_selected_context_changed (USER_SELECTED_FRAME);
 }
 
 

gdb/target-delegates-gen.c

@@ -172,7 +172,7 @@ struct dummy_target : public target_ops
   enum btrace_error read_btrace (struct btrace_data *arg0, struct btrace_target_info *arg1, enum btrace_read_type arg2) override;
   const struct btrace_config *btrace_conf (const struct btrace_target_info *arg0) override;
   enum record_method record_method (ptid_t arg0) override;
-  void stop_recording () override;
+  bool stop_recording () override;
   void info_record () override;
   void save_record (const char *arg0) override;
   bool supports_delete_record () override;
@@ -353,7 +353,7 @@ struct debug_target : public target_ops
   enum btrace_error read_btrace (struct btrace_data *arg0, struct btrace_target_info *arg1, enum btrace_read_type arg2) override;
   const struct btrace_config *btrace_conf (const struct btrace_target_info *arg0) override;
   enum record_method record_method (ptid_t arg0) override;
-  void stop_recording () override;
+  bool stop_recording () override;
   void info_record () override;
   void save_record (const char *arg0) override;
   bool supports_delete_record () override;
@@ -3794,24 +3794,28 @@ debug_target::record_method (ptid_t arg0)
   return result;
 }
 
-void
+bool
 target_ops::stop_recording ()
 {
-  this->beneath ()->stop_recording ();
+  return this->beneath ()->stop_recording ();
 }
 
-void
+bool
 dummy_target::stop_recording ()
 {
+  return false;
 }
 
-void
+bool
 debug_target::stop_recording ()
 {
   target_debug_printf_nofunc ("-> %s->stop_recording (...)", this->beneath ()->shortname ());
-  this->beneath ()->stop_recording ();
-  target_debug_printf_nofunc ("<- %s->stop_recording ()",
-	      this->beneath ()->shortname ());
+  bool result
+    = this->beneath ()->stop_recording ();
+  target_debug_printf_nofunc ("<- %s->stop_recording () = %s",
+	      this->beneath ()->shortname (),
+	      target_debug_print_bool (result).c_str ());
+  return result;
 }
 
 void

gdb/target.h

@@ -1236,9 +1236,9 @@ struct target_ops
     virtual enum record_method record_method (ptid_t ptid)
       TARGET_DEFAULT_RETURN (RECORD_METHOD_NONE);
 
-    /* Stop trace recording.  */
-    virtual void stop_recording ()
-      TARGET_DEFAULT_IGNORE ();
+    /* Stop trace recording.  Return whether the selected thread moved.  */
+    virtual bool stop_recording ()
+      TARGET_DEFAULT_RETURN (false);
 
     /* Print information about the recording.  */
     virtual void info_record ()

gdb/testsuite/gdb.btrace/step.exp

@@ -50,7 +50,7 @@ with_test_prefix "replay" {
 
 # Stop recording and try to step live (pr19340).
 with_test_prefix "live" {
-    gdb_test "record stop" "Process record is stopped.*"
+    gdb_test "record stop" "Process record is stopped.*fun4\.4.*"
     gdb_test "reverse-next" "Reverse execution is not currently supported.*"
     gdb_test "step" ".*fun3\.2.*"
 }