Re: Is WAL_DEBUG related code still relevant today?

On Wed, Dec 6, 2023, at 8:27 AM, Peter Eisentraut wrote:
> On 02.12.23 15:06, Bharath Rupireddy wrote:
> > I enabled this code by compiling with the WAL_DEBUG macro and setting
> > wal_debug GUC to on. Firstly, the compilation on Windows failed
> > because XL_ROUTINE was passed inappropriately for XLogReaderAllocate()
> > used.
>
> This kind of thing could be mostly avoided if we didn't hide all the
> WAL_DEBUG behind #ifdefs.

AFAICS LOCK_DEBUG also hides its GUCs behind #ifdefs. The fact that XLOG_DEBUG
is a variable but seems like a constant surprises me. I would rename it to
XLogDebug or xlog_debug.

> in the normal case. That way, we don't need to wrap that in #ifdef
> WAL_DEBUG, and the compiler can see the disabled code and make sure it
> continues to build.

I didn't check the LOCK_DEBUG code path to make sure it fits in the same
category as WAL_DEBUG. If it does, maybe it is worth to apply the same logic
there.

--
Euler Taveira
EDB https://www.enterprisedb.com/