Introduce switch_to_inferior_no_thread

Several places want to switch context to an inferior and its pspace,
while at the same time switch to "no thread selected".  This commit
adds a function that does that, and uses it in a few places.

gdb/ChangeLog:
2020-01-10  Pedro Alves <palves@redhat.com>

	* inferior.c (switch_to_inferior_no_thread): New function,
	factored out from ...
	(inferior_command): ... here.
	* inferior.h (switch_to_inferior_no_thread): Declare.
	* mi/mi-main.c (run_one_inferior): Use
	switch_to_inferior_no_thread.

4 files changed, 27 insertions, 13 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3b5f9aa..50c56c9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2020-01-10  Pedro Alves <palves@redhat.com>
+
+	* inferior.c (switch_to_inferior_no_thread): New function,
+	factored out from ...
+	(inferior_command): ... here.
+	* inferior.h (switch_to_inferior_no_thread): Declare.
+	* mi/mi-main.c (run_one_inferior): Use
+	switch_to_inferior_no_thread.
+
 2020-01-10  Pedro Alves  <palves@redhat.com>
 
 	* infcmd.c (kill_command): Remove dead code.
diff --git a/gdb/inferior.c b/gdb/inferior.c
index 3969ace..0c5e2c7 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -575,6 +575,16 @@ kill_inferior_command (const char *args, int from_tty)
   bfd_cache_close_all ();
 }
 
+/* See inferior.h.  */
+
+void
+switch_to_inferior_no_thread (inferior *inf)
+{
+  set_current_inferior (inf);
+  switch_to_no_thread ();
+  set_current_program_space (inf->pspace);
+}
+
 static void
 inferior_command (const char *args, int from_tty)
 {
@@ -605,9 +615,7 @@ inferior_command (const char *args, int from_tty)
     }
   else
     {
-      set_current_inferior (inf);
-      switch_to_no_thread ();
-      set_current_program_space (inf->pspace);
+      switch_to_inferior_no_thread (inf);
 
       gdb::observers::user_selected_context_changed.notify
 	(USER_SELECTED_INFERIOR);
@@ -737,11 +745,8 @@ add_inferior_command (const char *args, int from_tty)
       if (exec != NULL)
 	{
 	  /* Switch over temporarily, while reading executable and
-	     symbols.q.  */
-	  set_current_program_space (inf->pspace);
-	  set_current_inferior (inf);
-	  switch_to_no_thread ();
-
+	     symbols.  */
+	  switch_to_inferior_no_thread (inf);
 	  exec_file_attach (exec.get (), from_tty);
 	  symbol_file_add_main (exec.get (), add_flags);
 	}
diff --git a/gdb/inferior.h b/gdb/inferior.h
index fe94a01..a9baa52 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -308,6 +308,10 @@ extern inferior *current_inferior ();
 
 extern void set_current_inferior (inferior *);
 
+/* Switch inferior (and program space) to INF, and switch to no thread
+   selected.  */
+extern void switch_to_inferior_no_thread (inferior *inf);
+
 /* GDB represents the state of each program execution with an object
    called an inferior.  An inferior typically corresponds to a process
    but is more general and applies also to targets that do not have a
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index e677381..24daf3f 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -414,11 +414,7 @@ run_one_inferior (struct inferior *inf, void *arg)
       switch_to_thread (tp);
     }
   else
-    {
-      set_current_inferior (inf);
-      switch_to_no_thread ();
-      set_current_program_space (inf->pspace);
-    }
+    switch_to_inferior_no_thread (inf);
   mi_execute_cli_command (run_cmd, async_p,
 			  async_p ? "&" : NULL);
   return 0;