gdb: sim: add command line completion

For now, only the sub-command name is completed.  No support yet for
completing options to that command.  But even this is a huge step as
currently, nothing is completed, and the basic "help sim" is fairly
obtuse as to what exactly the "sim" command accepts.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2011-04-14  Mike Frysinger  <vapier@gentoo.org>
+
+	* remote-sim.c (sim_command_completer): New function.
+	(_initialize_remote_sim): Set completer to sim_command_completer.
+
 2011-04-13  Thiago Jung Bauermann  <bauerman@br.ibm.com>
 
 	* breakpoint.c (print_exception_catchpoint): Rename to ...

gdb/remote-sim.c

@@ -1193,6 +1193,18 @@ simulator_command (char *args, int from_tty)
   registers_changed ();
 }
 
+static char **
+sim_command_completer (struct cmd_list_element *ignore, char *text, char *word)
+{
+  struct sim_inferior_data *sim_data;
+
+  sim_data = inferior_data (current_inferior (), sim_inferior_data_key);
+  if (sim_data == NULL || sim_data->gdbsim_desc == NULL)
+    return NULL;
+
+  return sim_complete_command (sim_data->gdbsim_desc, text, word);
+}
+
 /* Check to see if a thread is still alive.  */
 
 static int
@@ -1287,11 +1299,14 @@ init_gdbsim_ops (void)
 void
 _initialize_remote_sim (void)
 {
+  struct cmd_list_element *c;
+
   init_gdbsim_ops ();
   add_target (&gdbsim_ops);
 
-  add_com ("sim", class_obscure, simulator_command,
+  c = add_com ("sim", class_obscure, simulator_command,
 	       _("Send a command to the simulator."));
+  set_cmd_completer (c, sim_command_completer);
 
   sim_inferior_data_key
     = register_inferior_data_with_cleanup (sim_inferior_data_cleanup);

include/gdb/ChangeLog

@@ -1,3 +1,7 @@
+2011-04-14  Mike Frysinger  <vapier@gentoo.org>
+
+	* remote-sim.h (sim_complete_command): New prototype.
+
 2011-03-05  Mike Frysinger  <vapier@gentoo.org>
 
 	* sim-bfin.h: New file.

include/gdb/remote-sim.h

@@ -276,6 +276,10 @@ void sim_stop_reason (SIM_DESC sd, enum sim_stop *reason, int *sigrc);
 
 void sim_do_command (SIM_DESC sd, char *cmd);
 
+/* Complete a command based on the available sim commands.  Returns an
+   array of possible matches.  */
+char **sim_complete_command (SIM_DESC sd, char *text, char *word);
+
 #ifdef __cplusplus
 }
 #endif

sim/common/ChangeLog

@@ -1,3 +1,8 @@
+2011-04-14  Mike Frysinger  <vapier@gentoo.org>
+
+	* sim-options.c (complete_option_list, sim_complete_command):
+	New functions.
+
 2011-04-02  Mike Frysinger  <vapier@gentoo.org>
 
 	* dv-glue.c: Fix up style.

sim/common/sim-options.c

@@ -915,6 +915,57 @@ find_match (SIM_DESC sd, sim_cpu *cpu, char *argv[], int *pargi)
   return matching_opt;
 }
 
+static char **
+complete_option_list (char **ret, size_t *cnt, const struct option_list *ol,
+		      char *text, char *word)
+{
+  const OPTION *opt = NULL;
+  int argi;
+  size_t len = strlen (word);
+
+  for ( ; ol != NULL; ol = ol->next)
+    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
+      {
+	const char *name = opt->opt.name;
+
+	/* A long option to match against?  */
+	if (!name)
+	  continue;
+
+	/* Does this option actually match?  */
+	if (strncmp (name, word, len))
+	  continue;
+
+	ret = xrealloc (ret, ++*cnt * sizeof (ret[0]));
+	ret[*cnt - 2] = xstrdup (name);
+      }
+
+  return ret;
+}
+
+/* All leading text is stored in @text, while the current word being
+   completed is stored in @word.  Trailing text of @word is not.  */
+char **
+sim_complete_command (SIM_DESC sd, char *text, char *word)
+{
+  char **ret = NULL;
+  size_t cnt = 1;
+  sim_cpu *cpu;
+
+  /* Only complete first word for now.  */
+  if (text != word)
+    return ret;
+
+  cpu = STATE_CPU (sd, 0);
+  if (cpu)
+    ret = complete_option_list (ret, &cnt, CPU_OPTIONS (cpu), text, word);
+  ret = complete_option_list (ret, &cnt, STATE_OPTIONS (sd), text, word);
+
+  if (ret)
+    ret[cnt - 1] = NULL;
+  return ret;
+}
+
 SIM_RC
 sim_args_command (SIM_DESC sd, char *cmd)
 {