Remove cmd_cfunc_ftype

This removes cmd_cfunc_ftype and the non-const overload of add_cmd;
then fixes up the fallout.

For the most part this patch is straightforward.  There are a few
files (go32-nat.c, windows-nat.c, and gnu-nat.c) that I could not
compile; so I made a best effort there.

gdb/ChangeLog
2017-11-07  Tom Tromey  <tom@tromey.com>

	* go32-nat.c (go32_sysinfo, go32_sldt, go32_sgdt, go32_sidt)
	(go32_pde, go32_pte, go32_pte_for_address): Constify.
	* gnu-nat.c (_parse_bool_arg, show_thread_default_pause_cmd)
	(set_thread_default_pause_cmd, set_thread_default_run_cmd)
	(show_thread_default_run_cmd, set_thread_default_detach_sc_cmd)
	(parse_int_arg, show_thread_default_detach_sc_cmd)
	(set_signals_cmd, show_signals_cmd, set_sig_thread_cmd)
	(show_sig_thread_cmd, set_stopped_cmd, show_stopped_cmd)
	(set_exceptions_cmd, show_exceptions_cmd, set_task_pause_cmd)
	(show_task_pause_cmd, set_task_detach_sc_cmd)
	(show_task_detach_sc_cmd, set_task_exc_port_cmd)
	(set_noninvasive_cmd, set_thread_pause_cmd)
	(show_thread_pause_cmd, set_thread_run_cmd, show_thread_run_cmd)
	(set_thread_detach_sc_cmd, show_thread_detach_sc_cmd)
	(set_thread_exc_port_cmd, thread_takeover_sc_cmd): Constify.
	* windows-nat.c (display_selectors): Constify.
	* cli/cli-decode.h (struct cmd_list_element) <function>: Remove
	non-const "cfunc".
	* cli/cli-decode.c (set_cmd_cfunc): Remove non-const overload.
	(cmd_cfunc_eq): Likewise.
	(struct cmd_list_element): Likewise.
	(do_cfunc): Remove.
	(cli_user_command_p): Update.
	* command.h (add_cmd): Remove non-const overload.
	(cmd_cfunc_ftype): Remove typedef.
	(cmd_cfunc_eq): Remove non-const overload.
	* value.c (show_values): Constify.
	* thread.c (thread_apply_all_command): Constify.
	* symfile.c (load_command): Constify.
	* source.c (directory_command): Constify.
	* maint.c (maintenance_internal_error)
	(maintenance_demangler_warning, maintenance_space_display)
	(maintenance_print_architecture, maintenance_translate_address)
	(maintenance_info_selftests, maintenance_internal_warning):
	Constify.
	* breakpoint.c (disable_trace_command, enable_trace_command):
	Constify.
	* auto-load.c (info_auto_load_local_gdbinit, add_auto_load_dir):
	Constify.
	(add_auto_load_safe_path): Constify.
	* guile/scm-auto-load.c (info_auto_load_guile_scripts): Constify.
	* top.h (show_commands): Constify.
	* linux-thread-db.c (info_auto_load_libthread_db): Constify.
	* sparc64-tdep.c (adi_examine_command): Constify.
	(adi_assign_command): Constify.

gdb/maint.c

@@ -44,10 +44,6 @@
 #include "cli/cli-utils.h"
 #include "cli/cli-setshow.h"
 
-static void maintenance_internal_error (char *args, int from_tty);
-
-static void maintenance_space_display (char *, int);
-
 static void maintenance_do_deprecate (const char *, int);
 
 /* Set this to the maximum number of seconds to wait instead of waiting forever
@@ -98,7 +94,7 @@ maintenance_dump_me (const char *args, int from_tty)
    GDB.  */
 
 static void
-maintenance_internal_error (char *args, int from_tty)
+maintenance_internal_error (const char *args, int from_tty)
 {
   internal_error (__FILE__, __LINE__, "%s", (args == NULL ? "" : args));
 }
@@ -109,7 +105,7 @@ maintenance_internal_error (char *args, int from_tty)
    GDB.  */
 
 static void
-maintenance_internal_warning (char *args, int from_tty)
+maintenance_internal_warning (const char *args, int from_tty)
 {
   internal_warning (__FILE__, __LINE__, "%s", (args == NULL ? "" : args));
 }
@@ -118,7 +114,7 @@ maintenance_internal_warning (char *args, int from_tty)
    demangler problem is detected.  Allows testing of the mechanism.  */
 
 static void
-maintenance_demangler_warning (char *args, int from_tty)
+maintenance_demangler_warning (const char *args, int from_tty)
 {
   demangler_warning (__FILE__, __LINE__, "%s", (args == NULL ? "" : args));
 }
@@ -143,7 +139,7 @@ maintenance_time_display (const char *args, int from_tty)
 }
 
 static void
-maintenance_space_display (char *args, int from_tty)
+maintenance_space_display (const char *args, int from_tty)
 {
   if (args == NULL || *args == '\0')
     printf_unfiltered ("\"maintenance space\" takes a numeric argument.\n");
@@ -394,7 +390,7 @@ maintenance_print_statistics (const char *args, int from_tty)
 }
 
 static void
-maintenance_print_architecture (char *args, int from_tty)
+maintenance_print_architecture (const char *args, int from_tty)
 {
   struct gdbarch *gdbarch = get_current_arch ();
 
@@ -429,11 +425,11 @@ maintenance_print_command (const char *arg, int from_tty)
    or   maintenance translate-address <addr>.  */
 
 static void
-maintenance_translate_address (char *arg, int from_tty)
+maintenance_translate_address (const char *arg, int from_tty)
 {
   CORE_ADDR address;
   struct obj_section *sect;
-  char *p;
+  const char *p;
   struct bound_minimal_symbol sym;
   struct objfile *objfile;
 
@@ -449,12 +445,13 @@ maintenance_translate_address (char *arg, int from_tty)
 	p++;
       if (*p == '\000')		/* End of command?  */
 	error (_("Need to specify <section-name> and <address>"));
-      *p++ = '\000';
-      p = skip_spaces (p);
+
+      int arg_len = p - arg;
+      p = skip_spaces (p + 1);
 
       ALL_OBJSECTIONS (objfile, sect)
       {
-	if (strcmp (sect->the_bfd_section->name, arg) == 0)
+	if (strncmp (sect->the_bfd_section->name, arg, arg_len) == 0)
 	  break;
       }
 
@@ -946,7 +943,7 @@ maintenance_selftest (const char *args, int from_tty)
 }
 
 static void
-maintenance_info_selftests (char *arg, int from_tty)
+maintenance_info_selftests (const char *arg, int from_tty)
 {
   printf_filtered ("Registered selftests:\n");
   selftests::for_each_selftest ([] (const std::string &name) {