On 2018-Nov-30, Sergei Kornilov wrote:
> Hello
>
> I can not build current HEAD cleanly. I got warning:
>
> > postgres.c: In function ‘check_log_duration’:
> > postgres.c:2254:17: warning: ‘in_sample’ may be used uninitialized in this
> > function [-Wmaybe-uninitialized]
> > if ((exceeded && in_sample) || log_duration)
Ah, I feared that some compiler would not be smart enough to be silent
about that. I hope it does not emit a warning with this patch?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 9a948f825d..5ab7d3cd8d 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -2244,12 +2244,13 @@ check_log_duration(char *msec_str, bool was_logged)
/*
* Do not log if log_statement_sample_rate = 0. Log a sample if
* log_statement_sample_rate <= 1 and avoid unecessary random() call
- * if log_statement_sample_rate = 1.
+ * if log_statement_sample_rate = 1. But don't compute any of this
+ * unless needed.
*/
- if (exceeded)
- in_sample = log_statement_sample_rate != 0 &&
- (log_statement_sample_rate == 1 ||
- random() <= log_statement_sample_rate * MAX_RANDOM_VALUE);
+ in_sample = exceeded &&
+ log_statement_sample_rate != 0 &&
+ (log_statement_sample_rate == 1 ||
+ random() <= log_statement_sample_rate * MAX_RANDOM_VALUE);
if ((exceeded && in_sample) || log_duration)
{
