Re: [PATCH 07/24] Remove "show" command completers

[Pedro Alves <palves@redhat.com>]

On 5/23/19 8:28 PM, Sergio Durigan Junior wrote:
> 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.

Wow, how did I miss that?  Much simpler, thanks!

Now that I do this, it stands out what made me look at this code
originally (which I had forgotten).

It's that the var_string "set" commands complete on symbols, but
that doesn't make much sense; that's what I first noticed when I
was writing the gdb.base/settings.exp testcase.  When I fixed that,
while looking at the code, I realized that the "show" commands shouldn't
also complete on anything.  And then just copied over the same code to all
set/show commands, failing to notice that I could do it in
add_setshow_cmd_full.

Here's the updated patch.

From f4ba132856c870156d145d556c6e77d4cafb60a9 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Wed, 22 May 2019 18:52:35 +0100
Subject: [PATCH 07/24] Remove "show" command completers, "set" command completers
 for string commands

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.

Also remove the completer for var_string and var_string_noescape
commands.  No point in completing symbols when GDB is expecting a
string.

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

	* cli/cli-decode.c (add_setshow_cmd_full): Remove "show"
	completer.
	(add_setshow_string_cmd, add_setshow_string_noescape_cmd): Remove
	"set" completers.
---
 gdb/cli/cli-decode.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 72e2a970097..80158593b38 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -508,6 +508,9 @@ add_setshow_cmd_full (const char *name,
 			      full_show_doc, show_list);
   show->doc_allocated = 1;
   show->show_value_func = show_func;
+  /* Disable the default symbol completer.  Doesn't make much sense
+     for the "show" command to complete on anything.  */
+  set_cmd_completer (show, nullptr);
 
   if (set_result != NULL)
     *set_result = set;
@@ -632,11 +635,16 @@ 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;
+
   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, NULL);
+
+  /* Disable the default symbol completer.  */
+  set_cmd_completer (set_cmd, nullptr);
 }
 
 /* Add element named NAME to both the set and show command LISTs (the
@@ -658,6 +666,10 @@ add_setshow_string_noescape_cmd (const char *name, enum command_class theclass,
 			set_func, show_func,
 			set_list, show_list,
 			&set_cmd, NULL);
+
+  /* Disable the default symbol completer.  */
+  set_cmd_completer (set_cmd, nullptr);
+
   return set_cmd;
 }
 
-- 
2.14.5