Re: Avoid unecessary MemSet call (src/backend/utils/cache/relcache.c)

On 07.07.22 13:16, Alvaro Herrera wrote:
> On 2022-Jul-07, Peter Eisentraut wrote:
> 
>> diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
>> index 4445a86aee..79b23fa7d7 100644
>> --- a/src/bin/pg_basebackup/pg_basebackup.c
>> +++ b/src/bin/pg_basebackup/pg_basebackup.c
> 
>> @@ -1952,7 +1948,6 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
>>   	else
>>   		starttli = latesttli;
>>   	PQclear(res);
>> -	MemSet(xlogend, 0, sizeof(xlogend));
>>   
>>   	if (verbose && includewal != NO_WAL)
>>   		pg_log_info("write-ahead log start point: %s on timeline %u",
> 
> You removed the MemSet here, but there's no corresponding
> initialization.

Maybe that was an oversight by me, but it seems to me that that 
initialization was useless anyway, since xlogend is later 
unconditionally overwritten anyway.

>> diff --git a/src/port/snprintf.c b/src/port/snprintf.c
>> index abb1c59770..e646b0e642 100644
>> --- a/src/port/snprintf.c
>> +++ b/src/port/snprintf.c
>> @@ -756,12 +756,9 @@ find_arguments(const char *format, va_list args,
>>   	int			longflag;
>>   	int			fmtpos;
>>   	int			i;
>> -	int			last_dollar;
>> -	PrintfArgType argtypes[PG_NL_ARGMAX + 1];
>> -
>>   	/* Initialize to "no dollar arguments known" */
>> -	last_dollar = 0;
>> -	MemSet(argtypes, 0, sizeof(argtypes));
>> +	int			last_dollar = 0;
>> +	PrintfArgType argtypes[PG_NL_ARGMAX + 1] = {0};
> 
> pgindent will insert a blank line before the comment, which I personally
> find quite ugly (because it splits the block of declarations).

Yeah.  I think I can convert that to an end-of-line comment instead.