Horton

Re: Allowing printf("%m") only where it actually works

Michael Paquier <michael@paquier.xyz>

View thread View on postgr.es
From: Michael Paquier <michael@paquier.xyz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-09-14T02:02:56Z
Lists: pgsql-hackers 
On Wed, Sep 12, 2018 at 01:40:01PM -0400, Tom Lane wrote:
> Michael Paquier <michael@paquier.xyz> writes:
> > I would have liked to look at this patch in details, but it failed to
> > apply.  Could you rebase?
> 
> Ah, yeah, the dlopen patch touched a couple of the same places.
> Rebase attached --- no substantive changes.

-       if (handleDLL == NULL)
-           ereport(FATAL,
-                   (errmsg_internal("could not load netmsg.dll: error
-            code %lu", GetLastError())));

In 0001, this is replaced by a non-FATAL error for the backend, which
does not seem like a good idea to me because the user loses visibility
with this DDL which canot be loaded.  I still have to see this error...

And about 0002.  I am surprised by the amount of cleanup that the
removal of all the special wrappers for %m gives, especially
expand_fmt_string.  So +1 for the concept.  I have been testing both
patches individually on Windows and compilation, as well as tests, do
not show any issues.  The tests have been done only with MSVC.

Could you drop the configure checks for snprintf and vsnprintf in a
separate patch?  The cleanup of %m and the removal of those switches
should be treated separatly in my opinion.
--
Michael

Commits

  1. In pg_log_generic(), be more paranoid about preserving errno.

  2. Make src/common/exec.c's error logging less ugly.

  3. Select appropriate PG_PRINTF_ATTRIBUTE for recent NetBSD.

  4. Fix detection of the result type of strerror_r().

  5. Try another way to detect the result type of strerror_r().

  6. Clean up *printf macros to avoid conflict with format archetypes.

  7. Fix link failures due to snprintf/strerror changes.

  8. Implement %m in src/port/snprintf.c, and teach elog.c to rely on that.

  9. Always use our own versions of *printf().

  10. Incorporate strerror_r() into src/port/snprintf.c, too.

  11. Convert elog.c's useful_strerror() into a globally-used strerror wrapper.

  12. Revert "Distinguish printf-like functions that support %m from those that don't."

  13. Produce compiler errors if errno is referenced inside elog/ereport calls.

  14. Distinguish printf-like functions that support %m from those that don't.

  15. Fix unportable usage of printf("%m").

  16. Be more robust when strerror() doesn't give a useful result.