[Bug ada/71072] New: [6/7] gnat doesn't respect --enable-default-pie

["doko at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71072

            Bug ID: 71072
           Summary: [6/7] gnat doesn't respect --enable-default-pie
           Product: gcc
           Version: 6.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org
  Target Milestone: ---

GCC 6 introduces the --enable-default-pie option, however it looks like gnat
doesn't respect this option.

Seen while running the examples/matrix test in gprbuild on x86_64-linux-gnu
(gnatgcc here is just a symlink to the gcc driver matching the gnat version):

make[1]: Entering directory '/tmp/adt-run.SU7baW/adttmp/examples/matrix'
gprconfig --batch --config Ada  --config C --config Fortran -o default.cgpr
Creating configuration file: default.cgpr
gprbuild
using project file matrix.gpr
gnatgcc -c -gnat05 main.adb
gfortran -c multmat.f
gcc -c initmat.c
gprbind main.bexch
gnatbind main.ali
gnatgcc -c b__main.adb
ar cr libmatrix.a ...
ranlib libmatrix.a
gfortran main.o -o main
/usr/bin/ld: main.o: relocation R_X86_64_32 against `.rodata' can not be used
when making a shared object; recompile with -fPIC
main.o: error adding symbols: Bad value
Makefile:2: recipe for target 'all' failed
make[1]: Leaving directory '/tmp/adt-run.SU7baW/adttmp/examples/matrix'
Makefile:5: recipe for target 'all' failed
collect2: error: ld returned 1 exit status
gprbuild: link of main.adb failed
make[1]: *** [all] Error 4