Re: Add null identifiers to genmatch

[Richard Biener <richard.guenther@gmail.com>]

On Mon, Nov 9, 2015 at 12:17 AM, Jeff Law <law@redhat.com> wrote:
> On 11/07/2015 07:31 AM, Pedro Alves wrote:
>>
>> Hi Richard,
>>
>> Passerby comment below.
>>
>> On 11/07/2015 01:21 PM, Richard Sandiford wrote:
>>>
>>> -/* Lookup the identifier ID.  */
>>> +/* Lookup the identifier ID.  Allow "null" if ALLOW_NULL.  */
>>>
>>>   id_base *
>>> -get_operator (const char *id)
>>> +get_operator (const char *id, bool allow_null = false)
>>>   {
>>> +  if (allow_null && strcmp (id, "null") == 0)
>>> +    return null_id;
>>> +
>>>     id_base tem (id_base::CODE, id);
>>
>>
>> Boolean params are best avoided if possible, IMO.  In this case,
>> it seems this could instead be a new wrapper function, like:
>
> This hasn't been something we've required for GCC.    I've come across this
> recommendation a few times over the last several months as I continue to
> look at refactoring and best practices for codebases such as GCC.
>
> By encoding the boolean in the function's signature, it (IMHO) does make the
> code a bit easier to read, primarily because you don't have to go lookup the
> tense of the boolean).  The problem is when the boolean is telling us some
> property an argument, but there's more than one argument and other similar
> situations.
>
> I wonder if the real benefit is in the refactoring necessary to do things in
> this way without a ton of code duplication.

I think the patch is ok as-is.

Thus ok.

Thanks,
Richard.

> Jeff
>
>