Constify strings in tracepoint.c, lookup_cmd and the completers.

This is sort of a continuation of Keith's parse_exp_1 constification
patch.  It started out by undoing these bits:

  @@ -754,9 +754,12 @@ validate_actionline (char **line, struct
   	  tmp_p = p;
   	  for (loc = t->base.loc; loc; loc = loc->next)
   	    {
  -	      p = tmp_p;
  -	      exp = parse_exp_1 (&p, loc->address,
  +	      const char *q;
  +
  +	      q = tmp_p;
  +	      exp = parse_exp_1 (&q, loc->address,
   				 block_for_pc (loc->address), 1);
  +	      p = (char *) q;

and progressively making more things const upwards, fixing fallout,
rinse repeat, until GDB built again (--enable-targets=all).

That ended up constifying lookup_cmd/add_cmd and (lots of) friends,
and the completers.

I didn't try to constify the command hooks themselves, because I know
upfront there are commands that write to the command string argument,
and I think I managed to stop at a nice non-hacky split point already.

I think the only non-really-super-obvious changes are
tracepoint.c:validate_actionline, and tracepoint.c:trace_dump_actions.

The rest is just mostly about 'char *' => 'const char *', 'char **'=>
'const char **', and the occasional (e.g., deprecated_cmd_warning)
case of 'char **'=> 'const char *', where/when I noticed that nothing
actually cares about the pointer to pointer output.

Tested on x86_64 Fedora 17, native and gdbserver.

gdb/
2013-03-13  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (struct add_partial_datum) <text, text0, word>: Make
	fields const.
	(ada_make_symbol_completion_list): Make "text0" parameter const.
	* ax-gdb.c (agent_eval_command_one): Make "exp" parameter const.
	* breakpoint.c (condition_completer): Make "text" and "word"
	parameters const.  Adjust.
	(check_tracepoint_command): Adjust to validate_actionline
	prototype change.
	(catch_syscall_completer): Make "text" and "word" parameters
	const.
	* cli/cli-cmds.c (show_user): Make "comname" local const.
	(valid_command_p): Make "command" parameter const.
	(alias_command): Make "alias_prefix" and "command_prefix" locals
	const.
	* cli/cli-decode.c (add_cmd): Make "name" parameter const.
	(add_alias_cmd): Make "name" and "oldname" parameters const.
	Adjust.  No longer make copy of OLDNAME.
	(add_prefix_cmd, add_abbrev_prefix_cmd, add_set_or_show_cmd)
	(add_setshow_cmd_full, add_setshow_enum_cmd)
	(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
	(add_setshow_filename_cmd, add_setshow_string_cmd)
	(add_setshow_string_noescape_cmd)
	(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
	(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
	(add_setshow_zuinteger_unlimited_cmd, add_setshow_zuinteger_cmd)
	(delete_cmd, add_info, add_info_alias, add_com, add_com_alias):
	Make "name" parameter const.
	(help_cmd): Rename "command" parameter to "arg".  New const local
	"command".
	(find_cmd): Make "command" parameter const.
	(lookup_cmd_1): Make "text" parameter pointer to const.  Adjust to
	deprecated_cmd_warning prototype change.
	(undef_cmd_error): Make "cmdtype" parameter const.
	(lookup_cmd): Make "line" parameter const.
	(deprecated_cmd_warning): Change type of "text" parameter to
	pointer to const char, from pointer to pointer to char.  Adjust.
	(lookup_cmd_composition): Make "text" parameter const.
	(complete_on_cmdlist, complete_on_enum): Make "text" and "word"
	parameters const.
	* cli/cli-decode.h (struct cmd_list_element) <name>: Make field
	const.
	* cli/cli-script.c (validate_comname): Make "tem" local const.
	(define_command): New const local "tem_c".  Use it in calls to
	lookup_cmd.
	(document_command): Make "tem" and "comfull" locals const.
	(show_user_1): Make "prefix" and "name" parameters const.
	* cli-script.h (show_user_1): Make "prefix" and "name" parameters
	const.
	* command.h (add_cmd, add_alias_cmd, add_prefix_cmd)
	(add_abbrev_prefix_cmd, completer_ftype, lookup_cmd, lookup_cmd_1)
	(deprecated_cmd_warning, lookup_cmd_composition, add_com)
	(add_com_alias, add_info, add_info_alias, complete_on_cmdlist)
	(complete_on_enum, add_setshow_enum_cmd)
	(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
	(add_setshow_filename_cmd, add_setshow_string_cmd)
	(add_setshow_string_noescape_cmd)
	(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
	(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
	(add_setshow_zuinteger_cmd, add_setshow_zuinteger_unlimited_cmd):
	Change prototypes, constifying strings.
	* completer.c (noop_completer, filename_completer): Make "text"
	and "prefix" parameters const.
	(location_completer, expression_completer)
	(complete_line_internal): Make "text" and "prefix" parameters
	const and adjust.
	(command_completer, signal_completer): Make "text" and "prefix"
	parameters const.
	* completer.h (noop_completer, filename_completer)
	(expression_completer, location_completer, command_completer)
	(signal_completer): Change prototypes.
	* corefile.c (complete_set_gnutarget): Make "text" and "word"
	parameters const.
	* cp-abi.c (cp_abi_completer): Likewise.
	* expression.h (parse_expression_for_completion): Change
	prototype.
	* f-lang.c (f_make_symbol_completion_list): Make "text" and "word"
	parameters const.
	* infcmd.c (_initialize_infcmd): Make "cmd_name" local const.
	* infrun.c (handle_completer): Make "text" and "word" parameters
	const.
	* interps.c (interpreter_completer): Make "text" and "word"
	parameters const.
	* language.h (struct language_defn)
	<la_make_symbol_completion_list>: Make "text" and "word"
	parameters const.
	* parse.c (parse_exp_1): Move const hack to parse_exp_in_context.
	(parse_exp_in_context): Rename to ...
	(parse_exp_in_context_1): ... this.
	(parse_exp_in_context): Reimplement, with const hack from
	parse_exp_1.
	(parse_expression_for_completion): Make "string" parameter const.
	* printcmd.c (decode_format): Make "string_ptr" parameter pointer
	to pointer to const char.  Adjust.
	(print_command_1): Make "exp" parameter const.
	(output_command): Rename to ...
	(output_command_const): ... this.  Make "exp" parameter const.
	(output_command): Reimplement.
	(x_command): Adjust.
	(display_command): Rename "exp" parameter to "arg".  New "exp"
	local, const version of "arg".
	* python/py-auto-load.c (gdbpy_initialize_auto_load): Make
	"cmd_name" local const.
	* python/py-cmd.c (cmdpy_destroyer): Cast const away in xfree
	call.
	(cmdpy_completer): Make "text" and "word" parameters const.
	(gdbpy_parse_command_name): Make "prefix_text2" local const.
	* python/py-param.c (add_setshow_generic): Make "tmp_name" local
	const.
	* remote.c (_initialize_remote): Make "cmd_name" local const.
	* symtab.c (language_search_unquoted_string): Make "text" and "p"
	parameters const.  Adjust.
	(completion_list_add_fields): Make "sym_text", "text" and "word"
	parameters const.
	(struct add_name_data) <sym_text, text, word>: Make fields const.
	(default_make_symbol_completion_list_break_on): Make "text" and
	"word" parameters const.  Adjust locals.
	(default_make_symbol_completion_list)
	(make_symbol_completion_list, make_symbol_completion_type)
	(make_symbol_completion_list_fn): Make "text" and "word"
	parameters const.
	(make_file_symbol_completion_list): Make "text", "word" and
	"srcfile" parameters const.  Adjust locals.
	(add_filename_to_list): Make "text" and "word" parameters const.
	(struct add_partial_filename_data) <text, word>: Make fields
	const.
	(make_source_files_completion_list): Make "text" and "word"
	parameters const.
	* symtab.h (default_make_symbol_completion_list_break_on)
	(default_make_symbol_completion_list, make_symbol_completion_list)
	(make_symbol_completion_type enum type_code)
	(make_symbol_completion_list_fn make_file_symbol_completion_list)
	(make_source_files_completion_list): Change prototype.
	* top.c (execute_command): Adjust to pass pointer to pointer to
	const char to lookup_cmd, and to deprecated_cmd_warning prototype
	change.
	(set_verbose): Make "cmdname" local const.
	* tracepoint.c (decode_agent_options): Make "exp" parameter const,
	and adjust.
	(validate_actionline): Make "line" parameter a pointer to const
	char, and adjust.
	(encode_actions_1): Make "action_exp" local const, and adjust.
	(encode_actions): Adjust.
	(replace_comma): Delete.
	(trace_dump_actions): Make "action_exp" and "next_comma" locals
	const, and adjust.  Don't frob the action string while splitting
	it at commas.  Instead, make a copy of each split substring in
	turn.
	(trace_dump_command): Adjust to validate_actionline prototype
	change.
	* tracepoint.h (decode_agent_options, decode_agent_options)
	(encode_actions, validate_actionline): Change prototypes.
	* valprint.h (output_command): Delete declaration.
	(output_command_const): Declare.
	* value.c (function_destroyer): Cast const away in xfree call.

gdb/cli/cli-decode.c

@@ -34,16 +34,16 @@
 
 /* Prototypes for local functions.  */
 
-static void undef_cmd_error (char *, char *);
+static void undef_cmd_error (const char *, const char *);
 
-static struct cmd_list_element *delete_cmd (char *name,
+static struct cmd_list_element *delete_cmd (const char *name,
 					    struct cmd_list_element **list,
 					    struct cmd_list_element **prehook,
 					    struct cmd_list_element **prehookee,
 					    struct cmd_list_element **posthook,
 					    struct cmd_list_element **posthookee);
 
-static struct cmd_list_element *find_cmd (char *command,
+static struct cmd_list_element *find_cmd (const char *command,
 					  int len,
 					  struct cmd_list_element *clist,
 					  int ignore_help_classes,
@@ -189,7 +189,7 @@ set_cmd_completer (struct cmd_list_element *cmd, completer_ftype *completer)
    of *LIST).  */
 
 struct cmd_list_element *
-add_cmd (char *name, enum command_class class, void (*fun) (char *, int),
+add_cmd (const char *name, enum command_class class, void (*fun) (char *, int),
 	 char *doc, struct cmd_list_element **list)
 {
   struct cmd_list_element *c
@@ -278,18 +278,15 @@ deprecate_cmd (struct cmd_list_element *cmd, char *replacement)
 }
 
 struct cmd_list_element *
-add_alias_cmd (char *name, char *oldname, enum command_class class,
+add_alias_cmd (const char *name, const char *oldname, enum command_class class,
 	       int abbrev_flag, struct cmd_list_element **list)
 {
-  /* Must do this since lookup_cmd tries to side-effect its first
-     arg.  */
-  char *copied_name;
+  const char *tmp;
   struct cmd_list_element *old;
   struct cmd_list_element *c;
 
-  copied_name = (char *) alloca (strlen (oldname) + 1);
-  strcpy (copied_name, oldname);
-  old = lookup_cmd (&copied_name, *list, "", 1, 1);
+  tmp = oldname;
+  old = lookup_cmd (&tmp, *list, "", 1, 1);
 
   if (old == 0)
     {
@@ -333,7 +330,7 @@ add_alias_cmd (char *name, char *oldname, enum command_class class,
    containing that list.  */
 
 struct cmd_list_element *
-add_prefix_cmd (char *name, enum command_class class,
+add_prefix_cmd (const char *name, enum command_class class,
 		void (*fun) (char *, int),
 		char *doc, struct cmd_list_element **prefixlist,
 		char *prefixname, int allow_unknown,
@@ -361,7 +358,7 @@ add_prefix_cmd (char *name, enum command_class class,
 /* Like add_prefix_cmd but sets the abbrev_flag on the new command.  */
 
 struct cmd_list_element *
-add_abbrev_prefix_cmd (char *name, enum command_class class,
+add_abbrev_prefix_cmd (const char *name, enum command_class class,
 		       void (*fun) (char *, int), char *doc,
 		       struct cmd_list_element **prefixlist, char *prefixname,
 		       int allow_unknown, struct cmd_list_element **list)
@@ -398,7 +395,7 @@ empty_sfunc (char *args, int from_tty, struct cmd_list_element *c)
    DOC is the documentation string.  */
 
 static struct cmd_list_element *
-add_set_or_show_cmd (char *name,
+add_set_or_show_cmd (const char *name,
 		     enum cmd_types type,
 		     enum command_class class,
 		     var_types var_type,
@@ -428,7 +425,7 @@ add_set_or_show_cmd (char *name,
    structures.  */
 
 static void
-add_setshow_cmd_full (char *name,
+add_setshow_cmd_full (const char *name,
 		      enum command_class class,
 		      var_types var_type, void *var,
 		      const char *set_doc, const char *show_doc,
@@ -481,7 +478,7 @@ add_setshow_cmd_full (char *name,
    which will contain the matching string (from ENUMLIST).  */
 
 void
-add_setshow_enum_cmd (char *name,
+add_setshow_enum_cmd (const char *name,
 		      enum command_class class,
 		      const char *const *enumlist,
 		      const char **var,
@@ -510,7 +507,7 @@ const char * const auto_boolean_enums[] = { "on", "off", "auto", NULL };
    variable which will contain the value.  DOC is the documentation
    string.  FUNC is the corresponding callback.  */
 void
-add_setshow_auto_boolean_cmd (char *name,
+add_setshow_auto_boolean_cmd (const char *name,
 			      enum command_class class,
 			      enum auto_boolean *var,
 			      const char *set_doc, const char *show_doc,
@@ -535,7 +532,7 @@ add_setshow_auto_boolean_cmd (char *name,
    add_cmd.  VAR is address of the variable which will contain the
    value.  SET_DOC and SHOW_DOC are the documentation strings.  */
 void
-add_setshow_boolean_cmd (char *name, enum command_class class, int *var,
+add_setshow_boolean_cmd (const char *name, enum command_class class, int *var,
 			 const char *set_doc, const char *show_doc,
 			 const char *help_doc,
 			 cmd_sfunc_ftype *set_func,
@@ -557,7 +554,7 @@ add_setshow_boolean_cmd (char *name, enum command_class class, int *var,
 /* Add element named NAME to both the set and show command LISTs (the
    list for set/show or some sublist thereof).  */
 void
-add_setshow_filename_cmd (char *name, enum command_class class,
+add_setshow_filename_cmd (const char *name, enum command_class class,
 			  char **var,
 			  const char *set_doc, const char *show_doc,
 			  const char *help_doc,
@@ -579,7 +576,7 @@ add_setshow_filename_cmd (char *name, enum command_class class,
 /* Add element named NAME to both the set and show command LISTs (the
    list for set/show or some sublist thereof).  */
 void
-add_setshow_string_cmd (char *name, enum command_class class,
+add_setshow_string_cmd (const char *name, enum command_class class,
 			char **var,
 			const char *set_doc, const char *show_doc,
 			const char *help_doc,
@@ -598,7 +595,7 @@ add_setshow_string_cmd (char *name, enum command_class class,
 /* Add element named NAME to both the set and show command LISTs (the
    list for set/show or some sublist thereof).  */
 struct cmd_list_element *
-add_setshow_string_noescape_cmd (char *name, enum command_class class,
+add_setshow_string_noescape_cmd (const char *name, enum command_class class,
 				 char **var,
 				 const char *set_doc, const char *show_doc,
 				 const char *help_doc,
@@ -620,7 +617,7 @@ add_setshow_string_noescape_cmd (char *name, enum command_class class,
 /* Add element named NAME to both the set and show command LISTs (the
    list for set/show or some sublist thereof).  */
 void
-add_setshow_optional_filename_cmd (char *name, enum command_class class,
+add_setshow_optional_filename_cmd (const char *name, enum command_class class,
 				   char **var,
 				   const char *set_doc, const char *show_doc,
 				   const char *help_doc,
@@ -647,7 +644,7 @@ add_setshow_optional_filename_cmd (char *name, enum command_class class,
    value.  SET_DOC and SHOW_DOC are the documentation strings.  This
    function is only used in Python API.  Please don't use it elsewhere.  */
 void
-add_setshow_integer_cmd (char *name, enum command_class class,
+add_setshow_integer_cmd (const char *name, enum command_class class,
 			 int *var,
 			 const char *set_doc, const char *show_doc,
 			 const char *help_doc,
@@ -668,7 +665,7 @@ add_setshow_integer_cmd (char *name, enum command_class class,
    add_cmd.  VAR is address of the variable which will contain the
    value.  SET_DOC and SHOW_DOC are the documentation strings.  */
 void
-add_setshow_uinteger_cmd (char *name, enum command_class class,
+add_setshow_uinteger_cmd (const char *name, enum command_class class,
 			  unsigned int *var,
 			  const char *set_doc, const char *show_doc,
 			  const char *help_doc,
@@ -689,7 +686,7 @@ add_setshow_uinteger_cmd (char *name, enum command_class class,
    add_cmd.  VAR is address of the variable which will contain the
    value.  SET_DOC and SHOW_DOC are the documentation strings.  */
 void
-add_setshow_zinteger_cmd (char *name, enum command_class class,
+add_setshow_zinteger_cmd (const char *name, enum command_class class,
 			  int *var,
 			  const char *set_doc, const char *show_doc,
 			  const char *help_doc,
@@ -706,7 +703,7 @@ add_setshow_zinteger_cmd (char *name, enum command_class class,
 }
 
 void
-add_setshow_zuinteger_unlimited_cmd (char *name,
+add_setshow_zuinteger_unlimited_cmd (const char *name,
 				     enum command_class class,
 				     int *var,
 				     const char *set_doc,
@@ -729,7 +726,7 @@ add_setshow_zuinteger_unlimited_cmd (char *name,
    add_cmd.  VAR is address of the variable which will contain the
    value.  SET_DOC and SHOW_DOC are the documentation strings.  */
 void
-add_setshow_zuinteger_cmd (char *name, enum command_class class,
+add_setshow_zuinteger_cmd (const char *name, enum command_class class,
 			   unsigned int *var,
 			   const char *set_doc, const char *show_doc,
 			   const char *help_doc,
@@ -753,7 +750,7 @@ add_setshow_zuinteger_cmd (char *name, enum command_class class,
    set to NULL.  */
 
 static struct cmd_list_element *
-delete_cmd (char *name, struct cmd_list_element **list,
+delete_cmd (const char *name, struct cmd_list_element **list,
 	    struct cmd_list_element **prehook,
 	    struct cmd_list_element **prehookee,
 	    struct cmd_list_element **posthook,
@@ -823,7 +820,7 @@ delete_cmd (char *name, struct cmd_list_element **list,
 /* Add an element to the list of info subcommands.  */
 
 struct cmd_list_element *
-add_info (char *name, void (*fun) (char *, int), char *doc)
+add_info (const char *name, void (*fun) (char *, int), char *doc)
 {
   return add_cmd (name, no_class, fun, doc, &infolist);
 }
@@ -831,7 +828,7 @@ add_info (char *name, void (*fun) (char *, int), char *doc)
 /* Add an alias to the list of info subcommands.  */
 
 struct cmd_list_element *
-add_info_alias (char *name, char *oldname, int abbrev_flag)
+add_info_alias (const char *name, char *oldname, int abbrev_flag)
 {
   return add_alias_cmd (name, oldname, 0, abbrev_flag, &infolist);
 }
@@ -839,7 +836,7 @@ add_info_alias (char *name, char *oldname, int abbrev_flag)
 /* Add an element to the list of commands.  */
 
 struct cmd_list_element *
-add_com (char *name, enum command_class class, void (*fun) (char *, int),
+add_com (const char *name, enum command_class class, void (*fun) (char *, int),
 	 char *doc)
 {
   return add_cmd (name, class, fun, doc, &cmdlist);
@@ -848,7 +845,7 @@ add_com (char *name, enum command_class class, void (*fun) (char *, int),
 /* Add an alias or abbreviation command to the list of commands.  */
 
 struct cmd_list_element *
-add_com_alias (char *name, char *oldname, enum command_class class,
+add_com_alias (const char *name, const char *oldname, enum command_class class,
 	       int abbrev_flag)
 {
   return add_alias_cmd (name, oldname, class, abbrev_flag, &cmdlist);
@@ -914,9 +911,10 @@ apropos_cmd (struct ui_file *stream,
    help_list.  */
 
 void
-help_cmd (char *command, struct ui_file *stream)
+help_cmd (char *arg, struct ui_file *stream)
 {
   struct cmd_list_element *c;
+  const char *command = arg;
 
   if (!command)
     {
@@ -1184,7 +1182,7 @@ help_cmd_list (struct cmd_list_element *list, enum command_class class,
    found in nfound.  */
 
 static struct cmd_list_element *
-find_cmd (char *command, int len, struct cmd_list_element *clist,
+find_cmd (const char *command, int len, struct cmd_list_element *clist,
 	  int ignore_help_classes, int *nfound)
 {
   struct cmd_list_element *found, *c;
@@ -1305,13 +1303,13 @@ valid_user_defined_cmd_name_p (const char *name)
    the struct cmd_list_element is NULL).  */
 
 struct cmd_list_element *
-lookup_cmd_1 (char **text, struct cmd_list_element *clist,
+lookup_cmd_1 (const char **text, struct cmd_list_element *clist,
 	      struct cmd_list_element **result_list, int ignore_help_classes)
 {
   char *command;
   int len, tmp, nfound;
   struct cmd_list_element *found, *c;
-  char *line = *text;
+  const char *line = *text;
 
   while (**text == ' ' || **text == '\t')
     (*text)++;
@@ -1376,7 +1374,7 @@ lookup_cmd_1 (char **text, struct cmd_list_element *clist,
        flags.  */
       
       if (found->flags & DEPRECATED_WARN_USER)
-	deprecated_cmd_warning (&line);
+	deprecated_cmd_warning (line);
       found = found->cmd_pointer;
     }
   /* If we found a prefix command, keep looking.  */
@@ -1423,7 +1421,7 @@ lookup_cmd_1 (char **text, struct cmd_list_element *clist,
 /* All this hair to move the space to the front of cmdtype */
 
 static void
-undef_cmd_error (char *cmdtype, char *q)
+undef_cmd_error (const char *cmdtype, const char *q)
 {
   error (_("Undefined %scommand: \"%s\".  Try \"help%s%.*s\"."),
 	 cmdtype,
@@ -1448,7 +1446,7 @@ undef_cmd_error (char *cmdtype, char *q)
    the function field of the struct cmd_list_element is 0).  */
 
 struct cmd_list_element *
-lookup_cmd (char **line, struct cmd_list_element *list, char *cmdtype,
+lookup_cmd (const char **line, struct cmd_list_element *list, char *cmdtype,
 	    int allow_unknown, int ignore_help_classes)
 {
   struct cmd_list_element *last_list = 0;
@@ -1544,14 +1542,14 @@ lookup_cmd (char **line, struct cmd_list_element *list, char *cmdtype,
   return 0;
 }
 
-/* We are here presumably because an alias or command in *TEXT is
+/* We are here presumably because an alias or command in TEXT is
    deprecated and a warning message should be generated.  This
-   function decodes *TEXT and potentially generates a warning message
+   function decodes TEXT and potentially generates a warning message
    as outlined below.
    
    Example for 'set endian big' which has a fictitious alias 'seb'.
    
-   If alias wasn't used in *TEXT, and the command is deprecated:
+   If alias wasn't used in TEXT, and the command is deprecated:
    "warning: 'set endian big' is deprecated." 
    
    If alias was used, and only the alias is deprecated:
@@ -1567,13 +1565,13 @@ lookup_cmd (char **line, struct cmd_list_element *list, char *cmdtype,
    
 */
 void
-deprecated_cmd_warning (char **text)
+deprecated_cmd_warning (const char *text)
 {
   struct cmd_list_element *alias = NULL;
   struct cmd_list_element *prefix_cmd = NULL;
   struct cmd_list_element *cmd = NULL;
 
-  if (!lookup_cmd_composition (*text, &alias, &prefix_cmd, &cmd))
+  if (!lookup_cmd_composition (text, &alias, &prefix_cmd, &cmd))
     /* Return if text doesn't evaluate to a command.  */
     return;
 
@@ -1641,7 +1639,7 @@ deprecated_cmd_warning (char **text)
    
 */
 int
-lookup_cmd_composition (char *text,
+lookup_cmd_composition (const char *text,
                       struct cmd_list_element **alias,
                       struct cmd_list_element **prefix_cmd, 
                       struct cmd_list_element **cmd)
@@ -1738,7 +1736,8 @@ lookup_cmd_composition (char *text,
    "oobar"; if WORD is "baz/foo", return "baz/foobar".  */
 
 VEC (char_ptr) *
-complete_on_cmdlist (struct cmd_list_element *list, char *text, char *word,
+complete_on_cmdlist (struct cmd_list_element *list,
+		     const char *text, const char *word,
 		     int ignore_help_classes)
 {
   struct cmd_list_element *ptr;
@@ -1808,8 +1807,7 @@ complete_on_cmdlist (struct cmd_list_element *list, char *text, char *word,
 
 VEC (char_ptr) *
 complete_on_enum (const char *const *enumlist,
-		  char *text,
-		  char *word)
+		  const char *text, const char *word)
 {
   VEC (char_ptr) *matchlist = NULL;
   int textlen = strlen (text);