Horton

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

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
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: 2018-08-13T03:03:31Z
Lists: pgsql-hackers 
On Sun, Aug 12, 2018 at 3:08 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Moreover,
> at least for the elog/ereport use-case, we'd be buying back some
> nontrivial part of that hit by getting rid of expand_fmt_string().

Yeah.  I think expand_fmt_string() is pretty costly if you are doing a
lot of errors (e.g. write a function that uses an EXCEPTION block to
map ERROR -> NULL return and then do SELECT catch_errors(blah) FROM
generate_series(1,10000000) g or so.  It seems altogether likely to me
that getting rid of the need for expand_fmt_string() will make for a
net win.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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.