10.41 breaks compilation of MariaDB and other consumers

[thesamesam]

MariaDB fails to compile with libpcre2-10.41 like so:

FAILED: client/CMakeFiles/mariadb-test.dir/mysqltest.cc.o 
/usr/bin/x86_64-pc-linux-gnu-g++ -DDBUG_TRACE -DHAVE_CONFIG_H -DHAVE_DLOPEN -DHAVE_OPENSSL -D_FILE_OFFSET_BITS=64 -Dmariadb_test_EXPORTS -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/libmariadb/include -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mariadb-10.5.17_build/libmariadb/include -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mariadb-10.5.17_build/include -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/include -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/mysys_ssl -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/sql -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/strings -I/var/tmp/portage/dev-db/mariadb-10.5.17/work/mariadb-10.5.17_build/client -I/usr/include/readline  -O2 -pipe -march=x86-64 -frecord-gcc-switches -fno-diagnostics-color -fmessage-length=0 -felide-constructors -fno-strict-aliasing -pie -fPIC -fstack-protector --param=ssp-buffer-size=4 -DNDEBUG -fno-omit-frame-pointer -D_FORTIFY_SOURCE=2 -DDBUG_OFF -Wall -Wenum-compare -Wenum-conversion -Wextra -Wformat-security -Wno-format-truncation -Wno-init-self -Wno-nonnull-compare -Wno-unused-parameter -Woverloaded-virtual -Wnon-virtual-dtor -Wvla -Wwrite-strings -std=gnu++11 -DTHREADS -MD -MT client/CMakeFiles/mariadb-test.dir/mysqltest.cc.o -MF client/CMakeFiles/mariadb-test.dir/mysqltest.cc.o.d -o client/CMakeFiles/mariadb-test.dir/mysqltest.cc.o -c /var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc
In file included from /var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:49:
/usr/include/pcre2posix.h:147:47: error: expected initializer before ‘pcre2_regcomp’
  147 | PCRE2POSIX_EXP_DECL int PCRE2_CALL_CONVENTION pcre2_regcomp(regex_t *, const char *, int);
      |                                               ^~~~~~~~~~~~~
/usr/include/pcre2posix.h:148:47: error: expected initializer before ‘pcre2_regexec’
  148 | PCRE2POSIX_EXP_DECL int PCRE2_CALL_CONVENTION pcre2_regexec(const regex_t *, const char *, size_t,
      |                                               ^~~~~~~~~~~~~
/usr/include/pcre2posix.h:150:50: error: expected initializer before ‘pcre2_regerror’
  150 | PCRE2POSIX_EXP_DECL size_t PCRE2_CALL_CONVENTION pcre2_regerror(int, const regex_t *, char *, size_t);
      |                                                  ^~~~~~~~~~~~~~
/usr/include/pcre2posix.h:151:48: error: expected initializer before ‘pcre2_regfree’
  151 | PCRE2POSIX_EXP_DECL void PCRE2_CALL_CONVENTION pcre2_regfree(regex_t *);
      |                                                ^~~~~~~~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘void check_regerr(regex_t*, int)’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:7389:5: error: ‘pcre2_regerror’ was not declared in this scope; did you mean ‘PCRE2regerror’?
 7389 |     regerror(err,r,err_buf,sizeof(err_buf));
      |     ^~~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘char* re_eprint(int)’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9246:11: error: ‘pcre2_regerror’ was not declared in this scope; did you mean ‘PCRE2regerror’?
 9246 |           regerror(err, (regex_t *)NULL, epbuf, sizeof(epbuf));
      |           ^~~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘void init_re_comp(regex_t*, const char*)’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9253:12: error: ‘pcre2_regcomp’ was not declared in this scope; did you mean ‘PCRE2regcomp’?
 9253 |   int err= regcomp(re, str, (REG_EXTENDED | REG_ICASE | REG_NOSUB | REG_DOTALL));
      |            ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9257:17: error: ‘pcre2_regerror’ was not declared in this scope; did you mean ‘PCRE2regerror’?
 9257 |     size_t len= regerror(err, re, erbuf, sizeof(erbuf));
      |                 ^~~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘int match_re(regex_t*, char*)’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9353:12: error: ‘pcre2_regexec’ was not declared in this scope; did you mean ‘PCRE2regexec’?
 9353 |   int err= regexec(re, str, (size_t)0, NULL, 0);
      |            ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9362:17: error: ‘pcre2_regerror’ was not declared in this scope; did you mean ‘PCRE2regerror’?
 9362 |     size_t len= regerror(err, re, erbuf, sizeof(erbuf));
      |                 ^~~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘void free_re()’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:9371:3: error: ‘pcre2_regfree’ was not declared in this scope; did you mean ‘PCRE2regfree’?
 9371 |   regfree(&ps_re);
      |   ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc: In function ‘int reg_replace(char**, int*, char*, char*, char*, int)’:
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:10862:18: error: ‘pcre2_regcomp’ was not declared in this scope; did you mean ‘PCRE2regcomp’?
10862 |   if ((err_code= regcomp(&r,pattern,cflags)))
      |                  ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:10879:15: error: ‘pcre2_regexec’ was not declared in this scope; did you mean ‘PCRE2regexec’?
10879 |     err_code= regexec(&r,str_p, r.re_nsub+1, subs,
      |               ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:10886:7: error: ‘pcre2_regfree’ was not declared in this scope; did you mean ‘PCRE2regfree’?
10886 |       regfree(&r);
      |       ^~~~~~~
/var/tmp/portage/dev-db/mariadb-10.5.17/work/mysql/client/mysqltest.cc:10999:3: error: ‘pcre2_regfree’ was not declared in this scope; did you mean ‘PCRE2regfree’?
10999 |   regfree(&r);
      |   ^~~~~~~

Initially reported downstream in Gentoo at https://bugs.gentoo.org/884705.

I suspect 1f5e47b caused this. Reverting to 10.40 or partly undoing 1f5e47b seems to fix it.

[thesamesam]

cc @cbouc

[cbouc]

To understand what's wrong, I'd need the result of the pre-compiler on mysqltest.cc to see myself what the context for the C++ compiler (don't know PCRE2POSIX_EXP_DECL and PCRE2_CALL_CONVENTION definitions here, or if they have at least an empty definition). Possibly, it's just a case of missing:

#ifndef PCRE2_CALL_CONVENTION
#define PCRE2_CALL_CONVENTION
#endif /*PCRE2_CALL_CONVENTION*/

in pcre2 common include files. Not able to build MariaDB by myself.

[cbouc]

I think I pinpointed the problem:
pcre2.h contains this:

/* When compiling with the MSVC compiler, it is sometimes necessary to include
a "calling convention" before exported function names. (This is secondhand
information; I know nothing about MSVC myself). For example, something like

  void __cdecl function(....)

might be needed. In order so make this easy, all the exported functions have
PCRE2_CALL_CONVENTION just before their names. It is rarely needed; if not
set, we ensure here that it has no effect. */

#ifndef PCRE2_CALL_CONVENTION
#define PCRE2_CALL_CONVENTION
#endif

But not pcre2posix.h ! And MariaDB seems to be using that file (in mysqltest.cc : #include "pcre2posix.h" / pcreposix regex library */*). Also, pcre2posif.h only #include <stdlib.h>, nothing to default PCRE2_CALL_CONVENTION definition.
Adding the same defaulting as in pcre2.h for PCRE2_CALL_CONVENTION in pcre2posix.h should solve the issue.

[thesamesam]

Thanks, I was off the computer yesterday. Let me take a look (although I note that cd8dc40 has been committed since which may fix it).

[thesamesam]

Yeah, that commit works for me. Thanks all!