Introduce interpreter factories

If every UI instance has its own set of interpreters, then the current
scheme of creating the interpreters at GDB initialization time no
longer works.  We need to create them whenever a new UI instance is
created.

The scheme implemented here has each interpreter register a factory
callback that when called creates a new instance of a specific
interpreter type.  Then, when some code in gdb looks up an interpreter
(always by name), if there's none yet, the factory method is called to
construct one.

gdb/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	* cli/cli-interp.c (cli_uiout): Delete, moved into ...
	(struct cli_interp): ... this new structure.
	(cli_on_normal_stop, cli_on_signal_received)
	(cli_on_end_stepping_range, cli_on_signal_exited, cli_on_exited)
	(cli_on_no_history): Use interp_ui_out.
	(cli_interpreter_init): If top level, set the cli_interp global.
	(cli_interpreter_init): Return the interp's data instead of NULL.
	(cli_interpreter_resume, cli_interpreter_exec, cli_ui_out): Adjust
	to cli_uiout being in the interpreter's data.
	(cli_interp_procs): New, factored out from _initialize_cli_interp.
	(cli_interp_factory): New function.
	(_initialize_cli_interp): Call interp_factory_register.
	* interps.c (get_interp_info): New, factored out from ...
	(get_current_interp_info): ... this.
	(interp_new): Add parameter 'data'.  Store it.
	(struct interp_factory): New function.
	(interp_factory_p): New typedef.  Define a VEC_P.
	(interpreter_factories): New global.
	(interp_factory_register): New function.
	(interp_add): Add 'ui' parameter.  Use get_interp_info and
	interp_lookup_existing.
	(interp_lookup): Rename to ...
	(interp_lookup_existing): ... this.  Add 'ui' parameter.  Don't
	check for NULL or empty name here.
	(interp_lookup): Add 'ui' parameter and reimplement.
	(interp_set_temp, interpreter_exec_cmd): Adjust.
	(interpreter_completer): Complete on registered interpreter
	factories instead of interpreters.
	* interps.h (interp_factory_func): New typedef.
	(interp_factory_register): Declare.
	(interp_new, interp_add): Adjust.
	(interp_lookup): Declare.
	* main.c (captured_main): Adjust.
	* mi/mi-interp.c (mi_cmd_interpreter_exec): Adjust.
	(mi_interp_procs): New, factored out from
	_initialize_mi_interp.
	(mi_interp_factory): New function.
	* python/python.c (execute_gdb_command): Adjust.
	* tui/tui-interp.c (tui_init): If top level, set the tui_interp
	global.
	(tui_interp_procs): New.
	(tui_interp_factory): New function.
	(_initialize_tui_interp): Call interp_factory_register.

8 files changed, 280 insertions, 91 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a6b34ed..599f43a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,51 @@
 2016-06-21  Pedro Alves  <palves@redhat.com>
 
+	* cli/cli-interp.c (cli_uiout): Delete, moved into ...
+	(struct cli_interp): ... this new structure.
+	(cli_on_normal_stop, cli_on_signal_received)
+	(cli_on_end_stepping_range, cli_on_signal_exited, cli_on_exited)
+	(cli_on_no_history): Use interp_ui_out.
+	(cli_interpreter_init): If top level, set the cli_interp global.
+	(cli_interpreter_init): Return the interp's data instead of NULL.
+	(cli_interpreter_resume, cli_interpreter_exec, cli_ui_out): Adjust
+	to cli_uiout being in the interpreter's data.
+	(cli_interp_procs): New, factored out from _initialize_cli_interp.
+	(cli_interp_factory): New function.
+	(_initialize_cli_interp): Call interp_factory_register.
+	* interps.c (get_interp_info): New, factored out from ...
+	(get_current_interp_info): ... this.
+	(interp_new): Add parameter 'data'.  Store it.
+	(struct interp_factory): New function.
+	(interp_factory_p): New typedef.  Define a VEC_P.
+	(interpreter_factories): New global.
+	(interp_factory_register): New function.
+	(interp_add): Add 'ui' parameter.  Use get_interp_info and
+	interp_lookup_existing.
+	(interp_lookup): Rename to ...
+	(interp_lookup_existing): ... this.  Add 'ui' parameter.  Don't
+	check for NULL or empty name here.
+	(interp_lookup): Add 'ui' parameter and reimplement.
+	(interp_set_temp, interpreter_exec_cmd): Adjust.
+	(interpreter_completer): Complete on registered interpreter
+	factories instead of interpreters.
+	* interps.h (interp_factory_func): New typedef.
+	(interp_factory_register): Declare.
+	(interp_new, interp_add): Adjust.
+	(interp_lookup): Declare.
+	* main.c (captured_main): Adjust.
+	* mi/mi-interp.c (mi_cmd_interpreter_exec): Adjust.
+	(mi_interp_procs): New, factored out from
+	_initialize_mi_interp.
+	(mi_interp_factory): New function.
+	* python/python.c (execute_gdb_command): Adjust.
+	* tui/tui-interp.c (tui_init): If top level, set the tui_interp
+	global.
+	(tui_interp_procs): New.
+	(tui_interp_factory): New function.
+	(_initialize_tui_interp): Call interp_factory_register.
+
+2016-06-21  Pedro Alves  <palves@redhat.com>
+
 	* breakpoint.c (bpstat_do_actions_1): Access the current UI's
 	async field instead of the interpreter_async global.
 	* cli/cli-script.c (execute_user_command, while_command)
diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index dfbd808..8eae0ac 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -26,9 +26,14 @@
 #include "infrun.h"
 #include "observer.h"
 
-/* These are the ui_out and the interpreter for the console
-   interpreter.  */
-struct ui_out *cli_uiout;
+/* The console interpreter.  */
+struct cli_interp
+{
+  /* The ui_out for the console interpreter.  */
+  struct ui_out *cli_uiout;
+};
+
+/* The interpreter for the console interpreter.  */
 static struct interp *cli_interp;
 
 /* Longjmp-safe wrapper for "execute_command".  */
@@ -48,7 +53,7 @@ cli_on_normal_stop (struct bpstats *bs, int print_frame)
   if (!interp_quiet_p (cli_interp))
     {
       if (print_frame)
-	print_stop_event (cli_uiout);
+	print_stop_event (interp_ui_out (cli_interp));
     }
 }
 
@@ -58,7 +63,7 @@ static void
 cli_on_signal_received (enum gdb_signal siggnal)
 {
   if (!interp_quiet_p (cli_interp))
-    print_signal_received_reason (cli_uiout, siggnal);
+    print_signal_received_reason (interp_ui_out (cli_interp), siggnal);
 }
 
 /* Observer for the end_stepping_range notification.  */
@@ -67,7 +72,7 @@ static void
 cli_on_end_stepping_range (void)
 {
   if (!interp_quiet_p (cli_interp))
-    print_end_stepping_range_reason (cli_uiout);
+    print_end_stepping_range_reason (interp_ui_out (cli_interp));
 }
 
 /* Observer for the signalled notification.  */
@@ -76,7 +81,7 @@ static void
 cli_on_signal_exited (enum gdb_signal siggnal)
 {
   if (!interp_quiet_p (cli_interp))
-    print_signal_exited_reason (cli_uiout, siggnal);
+    print_signal_exited_reason (interp_ui_out (cli_interp), siggnal);
 }
 
 /* Observer for the exited notification.  */
@@ -85,7 +90,7 @@ static void
 cli_on_exited (int exitstatus)
 {
   if (!interp_quiet_p (cli_interp))
-    print_exited_reason (cli_uiout, exitstatus);
+    print_exited_reason (interp_ui_out (cli_interp), exitstatus);
 }
 
 /* Observer for the no_history notification.  */
@@ -94,7 +99,7 @@ static void
 cli_on_no_history (void)
 {
   if (!interp_quiet_p (cli_interp))
-    print_no_history_reason (cli_uiout);
+    print_no_history_reason (interp_ui_out (cli_interp));
 }
 
 /* Observer for the sync_execution_done notification.  */
@@ -120,6 +125,9 @@ cli_on_command_error (void)
 static void *
 cli_interpreter_init (struct interp *self, int top_level)
 {
+  if (top_level)
+    cli_interp = self;
+
   /* If changing this, remember to update tui-interp.c as well.  */
   observer_attach_normal_stop (cli_on_normal_stop);
   observer_attach_end_stepping_range (cli_on_end_stepping_range);
@@ -130,12 +138,13 @@ cli_interpreter_init (struct interp *self, int top_level)
   observer_attach_sync_execution_done (cli_on_sync_execution_done);
   observer_attach_command_error (cli_on_command_error);
 
-  return NULL;
+  return interp_data (self);
 }
 
 static int
 cli_interpreter_resume (void *data)
 {
+  struct cli_interp *cli = (struct cli_interp *) data;
   struct ui_file *stream;
 
   /*sync_execution = 1; */
@@ -144,17 +153,17 @@ cli_interpreter_resume (void *data)
      previously writing to gdb_stdout, then set it to the new
      gdb_stdout afterwards.  */
 
-  stream = cli_out_set_stream (cli_uiout, gdb_stdout);
+  stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
   if (stream != gdb_stdout)
     {
-      cli_out_set_stream (cli_uiout, stream);
+      cli_out_set_stream (cli->cli_uiout, stream);
       stream = NULL;
     }
 
   gdb_setup_readline ();
 
   if (stream != NULL)
-    cli_out_set_stream (cli_uiout, gdb_stdout);
+    cli_out_set_stream (cli->cli_uiout, gdb_stdout);
 
   return 1;
 }
@@ -169,6 +178,7 @@ cli_interpreter_suspend (void *data)
 static struct gdb_exception
 cli_interpreter_exec (void *data, const char *command_str)
 {
+  struct cli_interp *cli = (struct cli_interp *) data;
   struct ui_file *old_stream;
   struct gdb_exception result;
 
@@ -184,9 +194,9 @@ cli_interpreter_exec (void *data, const char *command_str)
 
      It is important that it gets reset everytime, since the user
      could set gdb to use a different interpreter.  */
-  old_stream = cli_out_set_stream (cli_uiout, gdb_stdout);
-  result = safe_execute_command (cli_uiout, str, 1);
-  cli_out_set_stream (cli_uiout, old_stream);
+  old_stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
+  result = safe_execute_command (cli->cli_uiout, str, 1);
+  cli_out_set_stream (cli->cli_uiout, old_stream);
   return result;
 }
 
@@ -222,7 +232,34 @@ safe_execute_command (struct ui_out *command_uiout, char *command, int from_tty)
 static struct ui_out *
 cli_ui_out (struct interp *self)
 {
-  return cli_uiout;
+  struct cli_interp *cli = (struct cli_interp *) interp_data (self);
+
+  return cli->cli_uiout;
+}
+
+/* The CLI interpreter's vtable.  */
+
+static const struct interp_procs cli_interp_procs = {
+  cli_interpreter_init,		/* init_proc */
+  cli_interpreter_resume,	/* resume_proc */
+  cli_interpreter_suspend,	/* suspend_proc */
+  cli_interpreter_exec,		/* exec_proc */
+  cli_ui_out,			/* ui_out_proc */
+  NULL,                       	/* set_logging_proc */
+  cli_command_loop            	/* command_loop_proc */
+};
+
+/* Factory for CLI interpreters.  */
+
+static struct interp *
+cli_interp_factory (const char *name)
+{
+  struct cli_interp *cli = XNEW (struct cli_interp);
+
+  /* Create a default uiout builder for the CLI.  */
+  cli->cli_uiout = cli_out_new (gdb_stdout);
+
+  return interp_new (name, &cli_interp_procs, cli);
 }
 
 /* Standard gdb initialization hook.  */
@@ -231,19 +268,5 @@ extern initialize_file_ftype _initialize_cli_interp; /* -Wmissing-prototypes */
 void
 _initialize_cli_interp (void)
 {
-  static const struct interp_procs procs = {
-    cli_interpreter_init,	/* init_proc */
-    cli_interpreter_resume,	/* resume_proc */
-    cli_interpreter_suspend,	/* suspend_proc */
-    cli_interpreter_exec,	/* exec_proc */
-    cli_ui_out,			/* ui_out_proc */
-    NULL,                       /* set_logging_proc */
-    cli_command_loop            /* command_loop_proc */
-  };
-
-  /* Create a default uiout builder for the CLI.  */
-  cli_uiout = cli_out_new (gdb_stdout);
-  cli_interp = interp_new (INTERP_CONSOLE, &procs);
-
-  interp_add (cli_interp);
+  interp_factory_register (INTERP_CONSOLE, cli_interp_factory);
 }
diff --git a/gdb/interps.c b/gdb/interps.c
index f19db54..fd08de5 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -53,18 +53,25 @@ struct ui_interp_info
   struct interp *command_interpreter;
 };
 
-/* Get the current UI's ui_interp_info object.  Never returns NULL.  */
+/* Get UI's ui_interp_info object.  Never returns NULL.  */
 
 static struct ui_interp_info *
-get_current_interp_info (void)
+get_interp_info (struct ui *ui)
 {
-  struct ui *ui = current_ui;
-
   if (ui->interp_info == NULL)
     ui->interp_info = XCNEW (struct ui_interp_info);
   return ui->interp_info;
 }
 
+/* Get the current UI's ui_interp_info object.  Never returns
+   NULL.  */
+
+static struct ui_interp_info *
+get_current_interp_info (void)
+{
+  return get_interp_info (current_ui);
+}
+
 struct interp
 {
   /* This is the name in "-i=" and set interpreter.  */
@@ -91,18 +98,21 @@ struct interp
 
 void _initialize_interpreter (void);
 
+static struct interp *interp_lookup_existing (struct ui *ui,
+					      const char *name);
+
 /* interp_new - This allocates space for a new interpreter,
    fills the fields from the inputs, and returns a pointer to the
    interpreter.  */
 struct interp *
-interp_new (const char *name, const struct interp_procs *procs)
+interp_new (const char *name, const struct interp_procs *procs, void *data)
 {
   struct interp *new_interp;
 
   new_interp = XNEW (struct interp);
 
   new_interp->name = xstrdup (name);
-  new_interp->data = NULL;
+  new_interp->data = data;
   new_interp->quiet_p = 0;
   new_interp->procs = procs;
   new_interp->inited = 0;
@@ -113,14 +123,57 @@ interp_new (const char *name, const struct interp_procs *procs)
   return new_interp;
 }
 
+/* An interpreter factory.  Maps an interpreter name to the factory
+   function that instantiates an interpreter by that name.  */
+
+struct interp_factory
+{
+  /* This is the name in "-i=INTERP" and "interpreter-exec INTERP".  */
+  const char *name;
+
+  /* The function that creates the interpreter.  */
+  interp_factory_func func;
+};
+
+typedef struct interp_factory *interp_factory_p;
+DEF_VEC_P(interp_factory_p);
+
+/* The registered interpreter factories.  */
+static VEC(interp_factory_p) *interpreter_factories = NULL;
+
+/* See interps.h.  */
+
+void
+interp_factory_register (const char *name, interp_factory_func func)
+{
+  struct interp_factory *f;
+  int ix;
+
+  /* Assert that no factory for NAME is already registered.  */
+  for (ix = 0;
+       VEC_iterate (interp_factory_p, interpreter_factories, ix, f);
+       ++ix)
+    if (strcmp (f->name, name) == 0)
+      {
+	internal_error (__FILE__, __LINE__,
+			_("interpreter factory already registered: \"%s\"\n"),
+			name);
+      }
+
+  f = XNEW (struct interp_factory);
+  f->name = name;
+  f->func = func;
+  VEC_safe_push (interp_factory_p, interpreter_factories, f);
+}
+
 /* Add interpreter INTERP to the gdb interpreter list.  The
    interpreter must not have previously been added.  */
 void
-interp_add (struct interp *interp)
+interp_add (struct ui *ui, struct interp *interp)
 {
-  struct ui_interp_info *ui_interp = get_current_interp_info ();
+  struct ui_interp_info *ui_interp = get_interp_info (ui);
 
-  gdb_assert (interp_lookup (interp->name) == NULL);
+  gdb_assert (interp_lookup_existing (ui, interp->name) == NULL);
 
   interp->next = ui_interp->interp_list;
   ui_interp->interp_list = interp;
@@ -219,18 +272,15 @@ interp_set (struct interp *interp, int top_level)
   return 1;
 }
 
-/* interp_lookup - Looks up the interpreter for NAME.  If no such
-   interpreter exists, return NULL, otherwise return a pointer to the
-   interpreter.  */
-struct interp *
-interp_lookup (const char *name)
+/* Look up the interpreter for NAME.  If no such interpreter exists,
+   return NULL, otherwise return a pointer to the interpreter.  */
+
+static struct interp *
+interp_lookup_existing (struct ui *ui, const char *name)
 {
-  struct ui_interp_info *ui_interp = get_current_interp_info ();
+  struct ui_interp_info *ui_interp = get_interp_info (ui);
   struct interp *interp;
 
-  if (name == NULL || strlen (name) == 0)
-    return NULL;
-
   for (interp = ui_interp->interp_list;
        interp != NULL;
        interp = interp->next)
@@ -242,6 +292,36 @@ interp_lookup (const char *name)
   return NULL;
 }
 
+/* See interps.h.  */
+
+struct interp *
+interp_lookup (struct ui *ui, const char *name)
+{
+  struct interp_factory *factory;
+  struct interp *interp;
+  int ix;
+
+  if (name == NULL || strlen (name) == 0)
+    return NULL;
+
+  /* Only create each interpreter once per top level.  */
+  interp = interp_lookup_existing (ui, name);
+  if (interp != NULL)
+    return interp;
+
+  for (ix = 0;
+       VEC_iterate (interp_factory_p, interpreter_factories, ix, factory);
+       ++ix)
+    if (strcmp (factory->name, name) == 0)
+      {
+	interp = factory->func (name);
+	interp_add (ui, interp);
+	return interp;
+      }
+
+  return NULL;
+}
+
 /* Returns the current interpreter.  */
 
 struct ui_out *
@@ -273,7 +353,7 @@ struct interp *
 interp_set_temp (const char *name)
 {
   struct ui_interp_info *ui_interp = get_current_interp_info ();
-  struct interp *interp = interp_lookup (name);
+  struct interp *interp = interp_lookup (current_ui, name);
   struct interp *old_interp = ui_interp->current_interpreter;
 
   if (interp)
@@ -433,7 +513,7 @@ interpreter_exec_cmd (char *args, int from_tty)
 
   old_interp = ui_interp->current_interpreter;
 
-  interp_to_use = interp_lookup (prules[0]);
+  interp_to_use = interp_lookup (current_ui, prules[0]);
   if (interp_to_use == NULL)
     error (_("Could not find interpreter \"%s\"."), prules[0]);
 
@@ -469,15 +549,15 @@ static VEC (char_ptr) *
 interpreter_completer (struct cmd_list_element *ignore,
 		       const char *text, const char *word)
 {
-  struct ui_interp_info *ui_interp = get_current_interp_info ();
+  struct interp_factory *interp;
   int textlen;
   VEC (char_ptr) *matches = NULL;
-  struct interp *interp;
+  int ix;
 
   textlen = strlen (text);
-  for (interp = ui_interp->interp_list;
-       interp != NULL;
-       interp = interp->next)
+  for (ix = 0;
+       VEC_iterate (interp_factory_p, interpreter_factories, ix, interp);
+       ++ix)
     {
       if (strncmp (interp->name, text, textlen) == 0)
 	{
diff --git a/gdb/interps.h b/gdb/interps.h
index f0badc5..e5cd779 100644
--- a/gdb/interps.h
+++ b/gdb/interps.h
@@ -24,6 +24,16 @@
 
 struct ui_out;
 struct interp;
+struct ui;
+
+typedef struct interp *(*interp_factory_func) (const char *name);
+
+/* Each interpreter kind (CLI, MI, etc.) registers itself with a call
+   to this function, passing along its name, and a pointer to a
+   function that creates a new instance of an interpreter with that
+   name.  */
+extern void interp_factory_register (const char *name,
+				     interp_factory_func func);
 
 extern int interp_resume (struct interp *interp);
 extern int interp_suspend (struct interp *interp);
@@ -64,10 +74,18 @@ struct interp_procs
   interp_command_loop_ftype *command_loop_proc;
 };
 
-extern struct interp *interp_new (const char *name, const struct interp_procs *procs);
-extern void interp_add (struct interp *interp);
+extern struct interp *interp_new (const char *name,
+				  const struct interp_procs *procs,
+				  void *data);
+extern void interp_add (struct ui *ui, struct interp *interp);
 extern int interp_set (struct interp *interp, int top_level);
-extern struct interp *interp_lookup (const char *name);
+
+/* Look up the interpreter for NAME, creating one if none exists yet.
+   If NAME is not a interpreter type previously registered with
+   interp_factory_register, return NULL; otherwise return a pointer to
+   the interpreter.  */
+extern struct interp *interp_lookup (struct ui *ui, const char *name);
+
 extern struct ui_out *interp_ui_out (struct interp *interp);
 extern void *interp_data (struct interp *interp);
 extern const char *interp_name (struct interp *interp);
diff --git a/gdb/main.c b/gdb/main.c
index d84340e..221888d 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -962,7 +962,7 @@ captured_main (void *data)
 
   {
     /* Find it.  */
-    struct interp *interp = interp_lookup (interpreter_p);
+    struct interp *interp = interp_lookup (current_ui, interpreter_p);
 
     if (interp == NULL)
       error (_("Interpreter `%s' unrecognized"), interpreter_p);
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 4656e89..f8c007c 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -238,7 +238,7 @@ mi_cmd_interpreter_exec (char *command, char **argv, int argc)
     error (_("-interpreter-exec: "
 	     "Usage: -interpreter-exec interp command"));
 
-  interp_to_use = interp_lookup (argv[0]);
+  interp_to_use = interp_lookup (current_ui, argv[0]);
   if (interp_to_use == NULL)
     error (_("-interpreter-exec: could not find interpreter \"%s\""),
 	   argv[0]);
@@ -1242,25 +1242,35 @@ mi_set_logging (struct interp *interp, int start_log,
   return 1;
 }
 
+/* The MI interpreter's vtable.  */
+
+static const struct interp_procs mi_interp_procs =
+{
+  mi_interpreter_init,		/* init_proc */
+  mi_interpreter_resume,	/* resume_proc */
+  mi_interpreter_suspend,	/* suspend_proc */
+  mi_interpreter_exec,		/* exec_proc */
+  mi_ui_out, 			/* ui_out_proc */
+  mi_set_logging,		/* set_logging_proc */
+  mi_command_loop		/* command_loop_proc */
+};
+
+/* Factory for MI interpreters.  */
+
+static struct interp *
+mi_interp_factory (const char *name)
+{
+  return interp_new (name, &mi_interp_procs, NULL);
+}
+
 extern initialize_file_ftype _initialize_mi_interp; /* -Wmissing-prototypes */
 
 void
 _initialize_mi_interp (void)
 {
-  static const struct interp_procs procs =
-    {
-      mi_interpreter_init,	/* init_proc */
-      mi_interpreter_resume,	/* resume_proc */
-      mi_interpreter_suspend,	/* suspend_proc */
-      mi_interpreter_exec,	/* exec_proc */
-      mi_ui_out, 		/* ui_out_proc */
-      mi_set_logging,		/* set_logging_proc */
-      mi_command_loop		/* command_loop_proc */
-    };
-
   /* The various interpreter levels.  */
-  interp_add (interp_new (INTERP_MI1, &procs));
-  interp_add (interp_new (INTERP_MI2, &procs));
-  interp_add (interp_new (INTERP_MI3, &procs));
-  interp_add (interp_new (INTERP_MI, &procs));
+  interp_factory_register (INTERP_MI1, mi_interp_factory);
+  interp_factory_register (INTERP_MI2, mi_interp_factory);
+  interp_factory_register (INTERP_MI3, mi_interp_factory);
+  interp_factory_register (INTERP_MI, mi_interp_factory);
 }
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 19590f4..8a96828 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -656,7 +656,7 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
       make_cleanup_restore_ui_out (&current_uiout);
       /* Use the console interpreter uiout to have the same print format
 	for console or MI.  */
-      interp = interp_lookup ("console");
+      interp = interp_lookup (current_ui, "console");
       current_uiout = interp_ui_out (interp);
 
       prevent_dont_repeat ();
diff --git a/gdb/tui/tui-interp.c b/gdb/tui/tui-interp.c
index 7a0da48..7544500 100644
--- a/gdb/tui/tui-interp.c
+++ b/gdb/tui/tui-interp.c
@@ -138,6 +138,9 @@ tui_init (struct interp *self, int top_level)
   /* Install exit handler to leave the screen in a good shape.  */
   atexit (tui_exit);
 
+  if (top_level)
+    tui_interp = self;
+
   tui_initialize_static_data ();
 
   tui_initialize_io ();
@@ -207,25 +210,34 @@ tui_exec (void *data, const char *command_str)
   internal_error (__FILE__, __LINE__, _("tui_exec called"));
 }
 
+/* The TUI interpreter's vtable.  */
+
+static const struct interp_procs tui_interp_procs = {
+  tui_init,
+  tui_resume,
+  tui_suspend,
+  tui_exec,
+  tui_ui_out,
+  NULL,
+  cli_command_loop
+};
+
+/* Factory for TUI interpreters.  */
+
+static struct interp *
+tui_interp_factory (const char *name)
+{
+  return interp_new (name, &tui_interp_procs, NULL);
+}
+
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_tui_interp;
 
 void
 _initialize_tui_interp (void)
 {
-  static const struct interp_procs procs = {
-    tui_init,
-    tui_resume,
-    tui_suspend,
-    tui_exec,
-    tui_ui_out,
-    NULL,
-    cli_command_loop
-  };
-
-  /* Create a default uiout builder for the TUI.  */
-  tui_interp = interp_new (INTERP_TUI, &procs);
-  interp_add (tui_interp);
+  interp_factory_register (INTERP_TUI, tui_interp_factory);
+
   if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
     tui_start_enabled = 1;