Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael@paquier.xyz>, Alvaro Herrera <alvherre@2ndquadrant.com>, Thomas Munro <thomas.munro@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-09-26T20:21:19Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> The strerror push, I assume it's that at least, broke something on icc:
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=fulmar&dt=2018-09-26%2018%3A00%3A16

Yeah.  It looks like the problem is that configure's test for strerror_r's
return type does not work on icc:

onfigure:10784: checking whether strerror_r returns int
configure:10805: icc -std=gnu99 -c  -mp1 -fno-strict-aliasing -g -O2 -pthread -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS  -D_GNU_SOURCE -I/usr/include/libxml2  conftest.c >&5
conftest.c(45): warning #159: declaration is incompatible with previous "strerror_r" (declared at line 438 of "/usr/include/string.h")
  int strerror_r(int, char *, size_t);
      ^

configure:10805: $? = 0
configure:10812: result: yes

Configure is expecting this to throw a hard error (if the platform
declares strerror_r to return char*) but icc only makes it a warning.

What I am not quite figuring out here is how the code seemed to work
before.  Before this patch, it only mattered in libpq because that was the
only place using pqStrerror.  Maybe the regression tests don't ever
produce a strerror output from libpq?

			regards, tom lane

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.