what causes Clang to use libgcc_s.so in FreeBSD 12.0-R linker

[Jin Guojun[VFF]]

Following CC command used for build a shared library that worked on all 
FreeBSD releases before 12-R.

The -v CC option shows that linker indeed involves libgcc and gcc_s 
somehow, but no -static option was shown. Not clear what the error 
message implies. Also, none of these source code has GNU stuff in it and 
what linker tried to do with gcc libraries?

Is something changed for building shared libraries under 12-R?

Thanks,

-Jin


FBSD12:  cc -Wl,-r -o libccs.so `lorder avail_type.so arg_vc.so 
c_array.so calibrate.so colortog
.so c_map.so colort90.so dbvfft3d.so eta.so errors.so filter_f.so 
fits_io.so fourier.so gaussian
.so glb_vars.so histgram.so icc_r.so io_ready.so libpbm.so libpbm2.so 
libpbm4.so libpgm1.so libp
pm1.so libppm3.so libpbm1.so ln2argv.so message.so pict_r.so pgm_r.so 
q_sort.so rotate90.so t_co
nsum.so tv_random.so time-out.so dbg_memsz.so to_sep.so to_8.so 
quantto8.so sub_mean.so zalloc.s
o vfft3d.so vfft_2p.so c_map1.so c_to_c.so buffernw.so checksum.so 
dicm_h.so dir_unix.so eget_ws
z.so gif_r.so ip-hdr.so private.so piperead.so parsargu.so rast_r.so 
sock_cnct.so sock_init.so s
ock_subr.so swap_all.so table_if.so tv_empty.so tvmath.so u_db.so 
zreopen.so pip_read.so | tsort
`

/usr/bin/ld: error: attempted static link of dynamic object 
/usr/lib/libgcc_s.so
/usr/bin/ld: error: attempted static link of dynamic object 
/usr/lib/libgcc_s.so
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1 (ignored)

FBSD12: cc -v -Wl,-r -o libccs.so `lorder avail_type.so arg_vc.so 
c_array.so calibrate.so colortog.so c
_map.so colort90.so dbvfft3d.so eta.so errors.so filter_f.so fits_io.so 
fourier.so gaussian.so g
lb_vars.so histgram.so icc_r.so io_ready.so libpbm.so libpbm2.so 
libpbm4.so libpgm1.so libppm1.s
o libppm3.so libpbm1.so ln2argv.so message.so pict_r.so pgm_r.so 
q_sort.so rotate90.so t_consum.
so tv_random.so time-out.so dbg_memsz.so to_sep.so to_8.so quantto8.so 
sub_mean.so zalloc.so vff
t3d.so vfft_2p.so c_map1.so c_to_c.so buffernw.so checksum.so dicm_h.so 
dir_unix.so eget_wsz.so
gif_r.so ip-hdr.so private.so piperead.so parsargu.so rast_r.so 
sock_cnct.so sock_init.so sock_s
ubr.so swap_all.so table_if.so tv_empty.so tvmath.so u_db.so zreopen.so 
pip_read.so | tsort`
FreeBSD clang version 6.0.1 (tags/RELEASE_601/final 335540) (based on 
LLVM 6.0.1)
Target: x86_64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin
  "/usr/bin/ld" --eh-frame-hdr -dynamic-linker /libexec/ld-elf.so.1 
--hash-style=both --enable-ne
w-dtags -o libccs.so /usr/lib/crt1.o /usr/lib/crti.o /usr/lib/crtbegin.o 
-L/usr/lib -r pip_read.
so zreopen.so u_db.so tv_empty.so table_if.so rast_r.so parsargu.so 
piperead.so private.so ip-hd
r.so gif_r.so eget_wsz.so dir_unix.so dicm_h.so checksum.so buffernw.so 
c_map1.so vfft_2p.so sub
_mean.so to_8.so to_sep.so dbg_memsz.so time-out.so tv_random.so 
t_consum.so pgm_r.so pict_r.so
ln2argv.so libppm3.so libppm1.so libpgm1.so libpbm2.so libpbm.so 
io_ready.so icc_r.so histgram.s
o glb_vars.so gaussian.so fits_io.so filter_f.so eta.so dbvfft3d.so 
colort90.so c_map.so colorto
g.so calibrate.so c_array.so arg_vc.so avail_type.so tvmath.so 
swap_all.so sock_init.so sock_cnc
t.so vfft3d.so quantto8.so rotate90.so q_sort.so libpbm1.so libpbm4.so 
fourier.so sock_subr.so c
_to_c.so zalloc.so errors.so message.so -lgcc --as-needed -lgcc_s 
--no-as-needed -lc -lgcc --as-
needed -lgcc_s --no-as-needed /usr/lib/crtend.o /usr/lib/crtn.o
/usr/bin/ld: error: attempted static link of dynamic object 
/usr/lib/libgcc_s.so
/usr/bin/ld: error: attempted static link of dynamic object 
/usr/lib/libgcc_s.so
cc: error: linker command failed with exit code 1 (use -v to see invocation)