Re: [PATCH 1/4] gdb: add lookup_cmd_exact to simplify a common pattern

[Marco Barisione via Gdb-patches <gdb-patches@sourceware.org>]

On 10 Jan 2021, at 00:06, Lancelot SIX <lsix@lancelotsix.com> wrote:
> 
> Hi
> 
> I just have a few style-related remarks above.
> 
> On Fri, Jan 08, 2021 at 10:07:03AM +0000, Marco Barisione via Gdb-patches wrote:
>> +/* See command.h.  */
>> +
>> +struct cmd_list_element *
>> +lookup_cmd_exact (const char *name,
>> +		  struct cmd_list_element *list,
>> +		  bool ignore_help_classes)
>> +{
>> +  const char *tem = name;
>> +  struct cmd_list_element *cmd = lookup_cmd (&tem, list, "", NULL, -1,
> 
> Probably s/NULL/nullptr/ ?
> 
>> +					     ignore_help_classes);
>> +  if (cmd && strcmp (name, cmd->name) != 0)
> 
> I think gdb prefers explicit comparison to check for null pointers:
> 
> https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Comparison_With_NULL_And_Zero
> 
> +  if (cmd != nullptr && strcmp (name, cmd->name) != 0)

I tried (but I noticed I didn’t succeed!) to use nullptr and compare
with nullptr in new code or code which already looked like that.
Otherwise, I tried to stick to the style used in nearby code.

That is, if there's code like this:
    foo *bar = NULL;
When adding a new variable on the next line, I would use NULL for
consistency.

What is the approach used in GDB?
1. Add new code using the current style even if inconsistent with nearby
   code.
2. Stick to the style of nearby code.
3. Also update nearby code.


-- 
Marco Barisione