postgresql/config
Tom Lane 7e788a585a Allow PG_PRINTF_ATTRIBUTE to be different in C and C++ code.
Although clang claims to be compatible with gcc's printf format
archetypes, this appears to be a falsehood: it likes __syslog__
(which gcc does not, on most platforms) and doesn't accept
gnu_printf.  This means that if you try to use gcc with clang++
or clang with g++, you get compiler warnings when compiling
printf-like calls in our C++ code.  This has been true for quite
awhile, but it's gotten more annoying with the recent appearance
of several buildfarm members that are configured like this.

To fix, run separate probes for the format archetype to use with the
C and C++ compilers, and conditionally define PG_PRINTF_ATTRIBUTE
depending on __cplusplus.

(We could alternatively insist that you not mix-and-match C and
C++ compilers; but if the case works otherwise, this is a poor
reason to insist on that.)

This commit back-patches 0909380e4 into supported branches.

Discussion: https://postgr.es/m/986485.1764825548@sss.pgh.pa.us
Discussion: https://postgr.es/m/3988414.1771950285@sss.pgh.pa.us
Backpatch-through: 14-18
2026-02-25 11:57:26 -05:00
..
ax_pthread.m4 Update config/ax_pthread.m4 to latest upstream version. 2018-11-19 15:05:33 -05:00
c-compiler.m4 Allow PG_PRINTF_ATTRIBUTE to be different in C and C++ code. 2026-02-25 11:57:26 -05:00
c-library.m4 Enable Unix-domain sockets support on Windows 2020-03-28 15:01:01 +01:00
check_decls.m4 Fix configure's AC_CHECK_DECLS tests to work correctly with clang. 2018-11-19 12:01:47 -05:00
check_modules.pl Pre-beta mechanical code beautification. 2022-05-12 15:17:30 -04:00
config.guess Update config.guess and config.sub 2022-04-07 07:45:25 +02:00
config.sub Update config.guess and config.sub 2022-04-07 07:45:25 +02:00
general.m4 Rename configure.in to configure.ac 2020-07-24 10:42:08 +02:00
install-sh Fix install-strip on Mac OS X 2012-08-21 23:42:43 -04:00
libtool.m4 Rename AC_PROG_LD* macros to PGAC_PROG_LD*. This avoids clashes with the 2004-07-17 18:53:56 +00:00
llvm.m4 Don't put library-supplied -L/-I switches before user-supplied ones. 2025-07-29 15:17:41 -04:00
Makefile Install our "missing" script where PGXS builds can find it. 2015-12-11 16:15:05 -05:00
missing Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
perl.m4 Adjust configure to insist on Perl version >= 5.8.3. 2021-10-07 14:26:17 -04:00
pkg.m4 Fix collection of typos in the code and the documentation 2022-03-15 11:29:35 +09:00
prep_buildtree Fix vpath build 2019-03-27 23:36:00 +01:00
programs.m4 Use --strip-unneeded when stripping static libraries with GNU strip. 2023-04-20 18:12:48 -04:00
python.m4 Refactor DLSUFFIX handling 2022-03-25 08:56:02 +01:00
tcl.m4 configure: More use of AC_ARG_VAR 2019-01-18 08:38:34 +01:00