Re: Remove useless casts to (char *)

Peter Eisentraut <peter(at)eisentraut(dot)org> writes:

> On 06.02.25 12:49, Dagfinn Ilmari Mannsåker wrote:
>> I have only skimmed the patches, but one hunk jumped out at me:
>> Peter Eisentraut <peter(at)eisentraut(dot)org> writes:
>>
>>> diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
>>> index 1bf27d93cfa..937a2b02a4f 100644
>>> --- a/src/backend/libpq/pqcomm.c
>>> +++ b/src/backend/libpq/pqcomm.c
>>> @@ -1368,7 +1368,7 @@ internal_flush_buffer(const char *buf, size_t *start, size_t *end)
>>> {
>>> int r;
>>> - r = secure_write(MyProcPort, (char *) bufptr, bufend -
>>> bufptr);
>>> + r = secure_write(MyProcPort, unconstify(char *, bufptr), bufend - bufptr);
>>> if (r <= 0)
>>> {
>> Insted of unconstify here, could we not make secure_write() (and
>> be_tls_write()) take the buffer pointer as const void *, like the
>> attached?
>
> Yeah, that makes sense. I've committed that.

Thanks, and thanks for catching be_gssapi_write(), which I had missed
due to not having gssapi enabled in my test build.

> Here is a new patch set rebased over that.

I had a more thorough read-through this time (as well as applying and
building it), and it does make the code a lot more readable.

I noticed you in some places added extra parens around remaining casts
with offset additions, e.g.

- XLogRegisterData((char *) old_key_tuple->t_data + SizeofHeapTupleHeader,
+ XLogRegisterData(((char *) old_key_tuple->t_data) + SizeofHeapTupleHeader,
old_key_tuple->t_len - SizeofHeapTupleHeader);

But not in others:

- memcpy((char *) tuple->t_data + SizeofHeapTupleHeader,
- (char *) data,
- datalen);
+ memcpy((char *) tuple->t_data + SizeofHeapTupleHeader, data, datalen);

I don't have a particularly strong opinion either way (maybe -0.2 on the
extra parens), but I mainly think we should keep it consistent, and not
change it gratuitously.

Greppig indicates to me that the paren-less version is more common:

$ git grep -P '\(\w+\s*\**\) [\w>-]+ \+ \w+' | wc -l
283
$ git grep -P '\(\(\w+\s*\**\) [\w>-]+\) \+ \w+' | wc -l
96

So I think we should leave them as they are.

- ilmari