[07/24] Remove "show" command completers

  The default command completer is symbol_completer, but it makes no
sense for a "show" command to complete on symbols, or anything else,
really.

I wonder whether we should instead make the default be no completer.
That seems like a much larger/complicated audit/change, so I'd like to
move forward with this version, as it'll be covered by tests.  I
noticed this because a following patch will add a new
gdb.base/settings.exp testcase that exercises all sorts of details of
settings commands, including completing the show commands, using new
representative "maint test-settings <type or settings command>"
commands.

gdb/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* cli/cli-decode.c (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):
	Remove "show" completer.
---
 gdb/cli/cli-decode.c | 74 ++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 52 insertions(+), 22 deletions(-)
  

On Wednesday, May 22 2019, Pedro Alves wrote:

> The default command completer is symbol_completer, but it makes no
> sense for a "show" command to complete on symbols, or anything else,
> really.

Agreed.

> I wonder whether we should instead make the default be no completer.
> That seems like a much larger/complicated audit/change, so I'd like to
> move forward with this version, as it'll be covered by tests.  I
> noticed this because a following patch will add a new
> gdb.base/settings.exp testcase that exercises all sorts of details of
> settings commands, including completing the show commands, using new
> representative "maint test-settings <type or settings command>"
> commands.

I'm wondering why you chose to remove call set_cmd_completer on all of
the add_setshow_* functions if you could actually have called it once on
add_setshow_cmd_full, which is a static function and just used on
cli-decode.c anyway.

Otherwise, LGTM.

> gdb/ChangeLog:
> yyyy-mm-dd  Pedro Alves  <palves@redhat.com>
>
> 	* cli/cli-decode.c (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):
> 	Remove "show" completer.
> ---
>  gdb/cli/cli-decode.c | 74 ++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 52 insertions(+), 22 deletions(-)
>
> diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
> index 72e2a970097..0eae0dc0005 100644
> --- a/gdb/cli/cli-decode.c
> +++ b/gdb/cli/cli-decode.c
> @@ -545,6 +545,8 @@ add_setshow_enum_cmd (const char *name,
>  
>    set_cmd_context (c, context);
>    set_cmd_context (show, context);
> +
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  const char * const auto_boolean_enums[] = { "on", "off", "auto", NULL };
> @@ -564,14 +566,16 @@ add_setshow_auto_boolean_cmd (const char *name,
>  			      struct cmd_list_element **set_list,
>  			      struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *c;
> +  cmd_list_element *set, *show;
>  
>    add_setshow_cmd_full (name, theclass, var_auto_boolean, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&c, NULL);
> -  c->enums = auto_boolean_enums;
> +			&set, &show);
> +  set->enums = auto_boolean_enums;
> +
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -588,14 +592,16 @@ add_setshow_boolean_cmd (const char *name, enum command_class theclass, int *var
>  			 struct cmd_list_element **show_list)
>  {
>    static const char *boolean_enums[] = { "on", "off", NULL };
> -  struct cmd_list_element *c;
> +  cmd_list_element *set, *show;
>  
>    add_setshow_cmd_full (name, theclass, var_boolean, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&c, NULL);
> -  c->enums = boolean_enums;
> +			&set, &show);
> +  set->enums = boolean_enums;
> +
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -610,14 +616,16 @@ add_setshow_filename_cmd (const char *name, enum command_class theclass,
>  			  struct cmd_list_element **set_list,
>  			  struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set_result;
> +  struct cmd_list_element *set_result, *show_result;
>  
>    add_setshow_cmd_full (name, theclass, var_filename, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set_result, NULL);
> +			&set_result, &show_result);
>    set_cmd_completer (set_result, filename_completer);
> +
> +  set_cmd_completer (show_result, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -632,11 +640,17 @@ add_setshow_string_cmd (const char *name, enum command_class theclass,
>  			struct cmd_list_element **set_list,
>  			struct cmd_list_element **show_list)
>  {
> +  cmd_list_element *set_cmd, *show_cmd;
> +
>    add_setshow_cmd_full (name, theclass, var_string, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			NULL, NULL);
> +			&set_cmd, &show_cmd);
> +
> +  /* Disable the default symbol completer.  */
> +  set_cmd_completer (set_cmd, nullptr);
> +  set_cmd_completer (show_cmd, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -651,13 +665,18 @@ add_setshow_string_noescape_cmd (const char *name, enum command_class theclass,
>  				 struct cmd_list_element **set_list,
>  				 struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set_cmd;
> +  cmd_list_element *set_cmd, *show_cmd;
>  
>    add_setshow_cmd_full (name, theclass, var_string_noescape, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set_cmd, NULL);
> +			&set_cmd, &show_cmd);
> +
> +  /* Disable the default symbol completer.  */
> +  set_cmd_completer (set_cmd, nullptr);
> +  set_cmd_completer (show_cmd, nullptr);
> +
>    return set_cmd;
>  }
>  
> @@ -673,16 +692,16 @@ add_setshow_optional_filename_cmd (const char *name, enum command_class theclass
>  				   struct cmd_list_element **set_list,
>  				   struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set_result;
> +  cmd_list_element *set_result, *show_result;
>   
>    add_setshow_cmd_full (name, theclass, var_optional_filename, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set_result, NULL);
> +			&set_result, &show_result);
>  		
>    set_cmd_completer (set_result, filename_completer);
> -
> +  set_cmd_completer (show_result, nullptr);
>  }
>  
>  /* Completes on literal "unlimited".  Used by integer commands that
> @@ -717,15 +736,16 @@ add_setshow_integer_cmd (const char *name, enum command_class theclass,
>  			 struct cmd_list_element **set_list,
>  			 struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set;
> +  cmd_list_element *set, *show;
>  
>    add_setshow_cmd_full (name, theclass, var_integer, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set, NULL);
> +			&set, &show);
>  
>    set_cmd_completer (set, integer_unlimited_completer);
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -742,15 +762,16 @@ add_setshow_uinteger_cmd (const char *name, enum command_class theclass,
>  			  struct cmd_list_element **set_list,
>  			  struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set;
> +  cmd_list_element *set, *show;
>  
>    add_setshow_cmd_full (name, theclass, var_uinteger, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set, NULL);
> +			&set, &show);
>  
>    set_cmd_completer (set, integer_unlimited_completer);
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -767,11 +788,15 @@ add_setshow_zinteger_cmd (const char *name, enum command_class theclass,
>  			  struct cmd_list_element **set_list,
>  			  struct cmd_list_element **show_list)
>  {
> +  cmd_list_element *show;
> +
>    add_setshow_cmd_full (name, theclass, var_zinteger, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			NULL, NULL);
> +			NULL, &show);
> +
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  void
> @@ -786,15 +811,16 @@ add_setshow_zuinteger_unlimited_cmd (const char *name,
>  				     struct cmd_list_element **set_list,
>  				     struct cmd_list_element **show_list)
>  {
> -  struct cmd_list_element *set;
> +  cmd_list_element *set, *show;
>  
>    add_setshow_cmd_full (name, theclass, var_zuinteger_unlimited, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			&set, NULL);
> +			&set, &show);
>  
>    set_cmd_completer (set, integer_unlimited_completer);
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Add element named NAME to both the set and show command LISTs (the
> @@ -811,11 +837,15 @@ add_setshow_zuinteger_cmd (const char *name, enum command_class theclass,
>  			   struct cmd_list_element **set_list,
>  			   struct cmd_list_element **show_list)
>  {
> +  cmd_list_element *show;
> +
>    add_setshow_cmd_full (name, theclass, var_zuinteger, var,
>  			set_doc, show_doc, help_doc,
>  			set_func, show_func,
>  			set_list, show_list,
> -			NULL, NULL);
> +			NULL, &show);
> +
> +  set_cmd_completer (show, nullptr);
>  }
>  
>  /* Remove the command named NAME from the command list.  Return the
> -- 
> 2.14.5