Constify execute_command

This constifies execute_command and fixes up the callers.

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

	* event-top.h (command_handler): Constify.
	* record-full.c (cmd_record_full_start): Update.
	* thread.c (thread_apply_all_command): Update.
	* printcmd.c (eval_command): Update.
	* mi/mi-main.c (mi_execute_cli_command): Update.
	(mi_execute_async_cli_command): Update.
	* tui/tui-stack.c (tui_update_command): Update.
	* cli/cli-interp.c (safe_execute_command): Constify.
	* record.c (record_start): Update.
	(record_start, record_stop, cmd_record_start): Update.
	* record-btrace.c (cmd_record_btrace_bts_start): Update.
	(cmd_record_btrace_pt_start): Update.
	(cmd_record_btrace_start): Update.
	(cmd_record_btrace_start): Update.
	* reverse.c (exec_reverse_once): Update.
	* python/python.c (execute_gdb_command): Don't copy the command.
	* event-top.c (command_line_handler): Update.
	(command_handler): Constify.
	* defs.h (deprecated_call_command_hook): Constify.
	* cli/cli-script.h (execute_user_command): Constify.
	* cli/cli-script.c (execute_user_command): Constify.
	(execute_cmd_pre_hook, execute_cmd_post_hook): Constify.
	(enum command_control_type): Update.
	* main.c (catch_command_errors): Remove non-const overload.
	(catch_command_errors_ftype): Remove.
	* python/py-cmd.c (cmdpy_function): Constify.
	* guile/scm-cmd.c (cmdscm_function): Constify.
	* cli/cli-dump.c (call_dump_func): Constify.
	* cli/cli-decode.c (do_const_cfunc): Constify.
	(do_sfunc): Constify.
	(cmd_func): Constify.
	* gdbcmd.h (execute_command, execute_command_to_string): Constify.
	* top.h (execute_command): Constify.
	* top.c (execute_command): Constify.
	(execute_command_to_string): Constify.
	(deprecated_call_command_hook): Constify.
	* command.h (cmd_func): Constify.
	* cli/cli-decode.h (struct cmd_list_element) <func>: Constify.

gdb/cli/cli-decode.c

@@ -101,7 +101,7 @@ print_help_for_command (struct cmd_list_element *c, const char *prefix,
    bounce function (unless cfunc / sfunc is NULL that is).  */
 
 static void
-do_const_cfunc (struct cmd_list_element *c, char *args, int from_tty)
+do_const_cfunc (struct cmd_list_element *c, const char *args, int from_tty)
 {
   c->function.const_cfunc (args, from_tty);
 }
@@ -117,7 +117,7 @@ set_cmd_cfunc (struct cmd_list_element *cmd, cmd_const_cfunc_ftype *cfunc)
 }
 
 static void
-do_sfunc (struct cmd_list_element *c, char *args, int from_tty)
+do_sfunc (struct cmd_list_element *c, const char *args, int from_tty)
 {
   c->function.sfunc (args, from_tty, c);
 }
@@ -1909,7 +1909,7 @@ cmd_func_p (struct cmd_list_element *cmd)
 
 /* Call the command function.  */
 void
-cmd_func (struct cmd_list_element *cmd, char *args, int from_tty)
+cmd_func (struct cmd_list_element *cmd, const char *args, int from_tty)
 {
   if (cmd_func_p (cmd))
     {

gdb/cli/cli-decode.h

@@ -107,7 +107,7 @@ struct cmd_list_element
        cagney/2002-02-02: This function signature is evolving.  For
        the moment suggest sticking with either set_cmd_cfunc() or
        set_cmd_sfunc().  */
-    void (*func) (struct cmd_list_element *c, char *args, int from_tty);
+    void (*func) (struct cmd_list_element *c, const char *args, int from_tty);
     /* The command's real callback.  At present func() bounces through
        to one of the below.  */
     union

gdb/cli/cli-dump.c

@@ -344,7 +344,7 @@ struct dump_context
 };
 
 static void
-call_dump_func (struct cmd_list_element *c, char *args, int from_tty)
+call_dump_func (struct cmd_list_element *c, const char *args, int from_tty)
 {
   struct dump_context *d = (struct dump_context *) get_cmd_context (c);
 

gdb/cli/cli-interp.c

@@ -80,7 +80,7 @@ as_cli_interp (struct interp *interp)
 
 /* Longjmp-safe wrapper for "execute_command".  */
 static struct gdb_exception safe_execute_command (struct ui_out *uiout,
-						  char *command, 
+						  const char *command, 
 						  int from_tty);
 
 /* See cli-interp.h.
@@ -332,11 +332,6 @@ cli_interp::exec (const char *command_str)
   struct ui_file *old_stream;
   struct gdb_exception result;
 
-  /* FIXME: cagney/2003-02-01: Need to const char *propogate
-     safe_execute_command.  */
-  char *str = (char *) alloca (strlen (command_str) + 1);
-  strcpy (str, command_str);
-
   /* gdb_stdout could change between the time cli_uiout was
      initialized and now.  Since we're probably using a different
      interpreter which has a new ui_file for gdb_stdout, use that one
@@ -345,7 +340,7 @@ cli_interp::exec (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->cli_uiout->set_stream (gdb_stdout);
-  result = safe_execute_command (cli->cli_uiout, str, 1);
+  result = safe_execute_command (cli->cli_uiout, command_str, 1);
   cli->cli_uiout->set_stream (old_stream);
   return result;
 }
@@ -357,7 +352,8 @@ cli_interp_base::supports_command_editing ()
 }
 
 static struct gdb_exception
-safe_execute_command (struct ui_out *command_uiout, char *command, int from_tty)
+safe_execute_command (struct ui_out *command_uiout, const char *command,
+		      int from_tty)
 {
   struct gdb_exception e = exception_none;
   struct ui_out *saved_uiout;

gdb/cli/cli-script.c

@@ -369,7 +369,7 @@ execute_cmd_pre_hook (struct cmd_list_element *c)
     {
       scoped_restore_hook_in restore_hook (c);
       c->hook_in = 1; /* Prevent recursive hooking.  */
-      execute_user_command (c->hook_pre, (char *) 0);
+      execute_user_command (c->hook_pre, nullptr);
     }
 }
 
@@ -380,12 +380,12 @@ execute_cmd_post_hook (struct cmd_list_element *c)
     {
       scoped_restore_hook_in restore_hook (c);
       c->hook_in = 1; /* Prevent recursive hooking.  */
-      execute_user_command (c->hook_post, (char *) 0);
+      execute_user_command (c->hook_post, nullptr);
     }
 }
 
 void
-execute_user_command (struct cmd_list_element *c, char *args)
+execute_user_command (struct cmd_list_element *c, const char *args)
 {
   struct ui *ui = current_ui;
   struct command_line *cmdlines;
@@ -484,7 +484,7 @@ execute_control_command_1 (struct command_line *cmd)
       {
 	/* A simple command, execute it and return.  */
 	std::string new_line = insert_user_defined_cmd_args (cmd->line);
-	execute_command (&new_line[0], 0);
+	execute_command (new_line.c_str (), 0);
 	ret = cmd->control_type;
 	break;
       }

gdb/cli/cli-script.h

@@ -122,7 +122,7 @@ extern command_line_up copy_command_lines (struct command_line *cmds);
 
 /* Exported to gdb/infrun.c */
 
-extern void execute_user_command (struct cmd_list_element *c, char *args);
+extern void execute_user_command (struct cmd_list_element *c, const char *args);
 
 /* If we're in a user-defined command, replace any $argc/$argN
    reference found in LINE with the arguments that were passed to the