GHA PG16 tests failing on all warnings being treated as errors

[robe]

So I enabled PG16 on github actions and it's failing because of all sorts of warnings.

​https://github.com/postgis/postgis/actions/runs/3380700459/jobs/5613777652 Most notably in

gserialized_spgist_2d.c (use of error: passing argument 1 of 'DatumGetPointer' makes integer from pointer without a cast [-Werror=int-conversion] )

lwgeom_triggers.c:113:25: note: in expansion of macro 'DirectFunctionCall1'
  113 |   out = PointerGetDatum(DirectFunctionCall1(LWGEOM_addBBOX, in));
      |                         ^~~~~~~~~~~~~~~~~~~
In file included from lwgeom_triggers.c:26:
/usr/local/pgsql/include/server/postgres.h:670:29: note: expected 'const void *' but argument is of type 'Datum' {aka 'long unsigned int'}
  670 | PointerGetDatum(const void *X)

gserialized_spgist_3d.c:433:9: note: shadowed declaration is here
  433 |  BOX3D *box = DatumGetBox3DP(in->datums[0]);
      |         ^~~
In file included from ../libpgcommon/lwgeom_pg.h:22,
                 from gserialized_gist_2d.c:51:
/usr/local/pgsql/include/server/utils/geo_decls.h:239:25: note: expected 'const BOX *' but argument is of type 'BOX2DF *'
  239 | BoxPGetDatum(const BOX *X)
      |              ~~~~~~~~~~~^
gserialized_spgist_3d.c:484:10: error: declaration of 'box' shadows a previous local [-Werror=shadow=compatible-local]

I didn't think PG16 changed that recently, so these might exist in earlier. Looks like only PG14 GHA is testing in tests mode which treats all warnings as errors, and that one is running fine.

[Regina Obe <lr@…>]

In 2405b53/git:

Change PG16 to not treat warnings as errors. References #5278

[strk]

GHA is all green now, I guess this ticket can be closed

[robe]

No GHA is green because I changed the tests from usan_clang/tests to coverage.

coverage GHA script doesn't treat warnings as errors. But we do have a ton of warnings now which weren't present with PG15.

A lot of stuff they seem to be doing in the PG16 cycle is replacing their home grown functions with standard C ones. So I think that is what is causing these warnings. I haven't investigated in detail yet.