Let ui::input_fd be -1

This changes gdb so that, if ui::input_fd is set to -1, then it will
not be registered with the event loop.  This is useful for the DAP
support code I wrote, but as it turns out to also be useful to
Insight, it seems best to check it in separately.

diff --git a/gdb/event-top.c b/gdb/event-top.c
index 02b3786320f4eafc16d60d63d6358eec10e8bbd3..4547d61452266a17c25a12c06d113a8faf5db633 100644 (file)
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -533,8 +533,9 @@ stdin_event_handler (int error, gdb_client_data client_data)
 void
 ui::register_file_handler ()
 {
-  add_file_handler (input_fd, stdin_event_handler, this,
-                   string_printf ("ui-%d", num), true);
+  if (input_fd != -1)
+    add_file_handler (input_fd, stdin_event_handler, this,
+                     string_printf ("ui-%d", num), true);
 }
 
 /* See top.h.  */
@@ -542,7 +543,8 @@ ui::register_file_handler ()
 void
 ui::unregister_file_handler ()
 {
-  delete_file_handler (input_fd);
+  if (input_fd != -1)
+    delete_file_handler (input_fd);
 }
 
 /* Re-enable stdin after the end of an execution command in

diff --git a/gdb/top.h b/gdb/top.h
index 5c1db84b2ce1c3f0531f34f1272f9c2ec0304229..9ea07262c39c5a034fc3a9a4ce466ed581bd3eaf 100644 (file)
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -118,7 +118,8 @@ struct ui
   FILE *errstream;
 
   /* The file descriptor for the input stream, so that we can register
-     it with the event loop.  */
+     it with the event loop.  This can be set to -1 to prevent this
+     registration.  */
   int input_fd;
 
   /* Whether ISATTY returns true on input_fd.  Cached here because