Re: pgsql: Replace random(), pg_erand48(), etc with a better PRNG API and a

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> Replace random(), pg_erand48(), etc with a better PRNG API and algorithm.

Hmm, fairywren doesn't like this [1]:

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Werror=vla -Wendif-labels -Wmissing-format-attribute -Wimplicit-fallthrough=3 -Wcast-function-type -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -Wno-format-truncation -Wno-stringop-truncation -g -O2 win32ver.o pg_test_fsync.o -L../../../src/port -L../../../src/common -Wl,--allow-multiple-definition -Wl,--disable-auto-import -L/c/prog/3p64/lib -L/c/prog/3p64/openssl/lib -Wl,--as-needed -lpgcommon -lpgport -lssl -lcrypto -lz -lws2_32 -lm -lws2_32 -o pg_test_fsync.exe
C:/tools/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: pg_test_fsync.o: in function `main':
C:/tools/msys64/home/pgrunner/bf/root/HEAD/pgsql.build/../pgsql/src/bin/pg_test_fsync/pg_test_fsync.c:121: undefined reference to `__imp_pg_global_prng_state'
collect2.exe: error: ld returned 1 exit status

I think what is going on here is that the compilation of pg_test_fsync.c
sees

extern PGDLLIMPORT pg_prng_state pg_global_prng_state;

and does something that's inappropriate when the variable is actually
coming from elsewhere in the same program. If so, we could perhaps
fix it by doing

#ifdef FRONTEND
extern pg_prng_state pg_global_prng_state;
#else
extern PGDLLIMPORT pg_prng_state pg_global_prng_state;
#endif

Thoughts?

regards, tom lane

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=fairywren&dt=2021-11-29%2003%3A04%3A24