Re: [PATCH 06/40] Expression completer should not match explicit location options

[Pedro Alves <palves@redhat.com>]

On 06/29/2017 12:07 PM, Pedro Alves wrote:
> On 06/29/2017 11:56 AM, Pedro Alves wrote:
> 
>> The patch fixes this by having the expression_completer function
>> bypass the function that completes explicit locations:
>>
>>     /* Not ideal but it is what we used to do before...  */
>>  -  return location_completer (ignore, p, word);
>>  +  return linespec_location_completer (ignore, text, word);
>>
> 
> Hmm, reading this back made my realize that I'm dropping "p"
> here, which is computed just above.  That doesn't make a difference
> to the test added by 37cd5d19fecc (2008), which was the commit
> that added that code.  Hmm, looks like that's a bit of dead code
> we can remove.
> 


I've split that to a separate preparatory patch and pushed it in,
as below, after doing some archaeology.

From 195bcdd5183f2c137399db23a68a26a4e4193f8f Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Thu, 29 Jun 2017 15:52:37 +0100
Subject: [PATCH] Remove old stale expression_completer hack

The code in question was introduced by:

 https://sourceware.com/ml/gdb-patches/2008-06/msg00143.html

"The fix is to make sure that the entire expression is passed to
expression_completer, then duplicate some logic there in the case
where location_completer is called."

The logic that was duplicated was much later on removed by the
original explicit locations patch:

 commit 87f0e7204722a986f79f245eee716f0870832d47
 Author:     Keith Seitz <keiths@redhat.com>
 AuthorDate: Tue Aug 11 17:09:36 2015 -0700
 Commit:     Keith Seitz <keiths@redhat.com>
 CommitDate: Tue Aug 11 17:09:36 2015 -0700

     Explicit locations: add UI features for CLI

 @@ -688,16 +880,6 @@ complete_line_internal (const char *text,
		       rl_completer_word_break_characters =
			 gdb_completer_file_name_break_characters;
		     }
 -                 else if (c->completer == location_completer)
 -                   {
 -                     /* Commands which complete on locations want to
 -                        see the entire argument.  */
 -                     for (p = word;
 -                          p > tmp_command
 -                            && p[-1] != ' ' && p[-1] != '\t';
 -                          p--)
 -                       ;
 -                   }

However this case in expression_completer was left behind.

I couldn't come up with a test where this currently makes any
difference.

gdb/ChangeLog:
2017-06-29  Pedro Alves  <palves@redhat.com>

	* completer.c (expression_completer): Remove code that recomputes
	'text' from 'word'.
---
 gdb/ChangeLog   |  5 +++++
 gdb/completer.c | 10 +---------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9be08dd..c76158f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-29  Pedro Alves  <palves@redhat.com>
+
+	* completer.c (expression_completer): Remove code that recomputes
+	'text' from 'word'.
+
 2017-06-29  Yao Qi  <yao.qi@linaro.org>
 
 	* regformats/regdat.sh: Generate code with
diff --git a/gdb/completer.c b/gdb/completer.c
index 6acf115..f152dd5 100644
--- a/gdb/completer.c
+++ b/gdb/completer.c
@@ -587,7 +587,6 @@ expression_completer (struct cmd_list_element *ignore,
 {
   struct type *type = NULL;
   char *fieldname;
-  const char *p;
   enum type_code code = TYPE_CODE_UNDEF;
 
   /* Perform a tentative parse of the expression, to see whether a
@@ -635,15 +634,8 @@ expression_completer (struct cmd_list_element *ignore,
     }
   xfree (fieldname);
 
-  /* Commands which complete on locations want to see the entire
-     argument.  */
-  for (p = word;
-       p > text && p[-1] != ' ' && p[-1] != '\t';
-       p--)
-    ;
-
   /* Not ideal but it is what we used to do before...  */
-  return location_completer (ignore, p, word);
+  return location_completer (ignore, text, word);
 }
 
 /* See definition in completer.h.  */
-- 
2.5.5