Sort out CFLAGS differences in raster/rt_pg and liblwgeom/

[strk]

Looking at compiler warnings it came to my attention that some warnings are only output under raster/rt_pg. On a closer look, the compiler flags used there and in liblwgeom (for example) are different !

Here's the build line for raster/rt_pg/rtpostgis.c:

gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -g -fpic -I/usr/local/include  -I/usr/include/libxml2 -I/usr/local/include -DHAVE_SFCGAL    "-I../../liblwgeom" -I/usr/local/include "-I../../libpgcommon"  -I../rt_core -I. -I. -I/home/postgresql-9.3.4/include/server -I/home/postgresql-9.3.4/include/internal -D_GNU_SOURCE -I/usr/include/libxml2   -c -o rtpostgis.o rtpostgis.c

And here's the one for liblwgeom/lwutil.c:

/bin/bash ../libtool --mode=compile gcc -g -O2  -fPIC -DPIC  -Wall -Wmissing-prototypes -I/usr/local/include   -I/usr/local/include -DHAVE_SFCGAL -c -o lwutil.lo lwutil.c
libtool: compile:  gcc -g -O2 -fPIC -DPIC -Wall -Wmissing-prototypes -I/usr/local/include -I/usr/local/include -DHAVE_SFCGAL -c lwutil.c  -fPIC -DPIC -o .libs/lwutil.o

There's definitely something missing (warning flags, mostly) in liblwgeom.

Note that the liblwgeom issue is not libtool related as you can see from the build line for loader/shp2pgsql-core.c:

gcc -I ../liblwgeom -g -O2  -fPIC -DPIC  -Wall -Wmissing-prototypes    -c shp2pgsql-core.c

[strk]

there seem to be duplications in CFLAGS and CPPFLAGS, would be better to sort this one once for all

[pramsey]

Isn't this just an expected consequence of the pgsql modules (postgis/rt_postgis) inheriting their build info from pgxs while the core parts set their own flags (liblwgeom/rt_core)? Unless we read build flags from pg_config for all modules I don't see how we avoid some mismatching.

[robe]

Milestone renamed

[strk]

It's to be checked if r16002 fixed this (from #3604)

[strk]

pramsey: it looks like you're right, this is a consequence of PGXS driving the flags ! Today for example, on a new system, I have different flags:

gcc "-I../../liblwgeom"  -fPIC -I/usr/local/include   -I/usr/include/libxml2     -I/usr/local/include "-I../../libpgcommon"  -I../rt_core -I. -I./ -I/usr/include/postgresql/9.6/server -I/usr/include/postgresql/internal -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -I/usr/include/libxml2  -I/usr/include/tcl8.6  -c -o rtpg_create.o rtpg_create.c

I'm not sure what we want to do about this, if anything. Should we extract PGXS flags once from ./configure and use ours always?

[Algunenano]

This should be fixed with ​https://trac.osgeo.org/postgis/ticket/3995