cc -g -O -c foo.c  -fPIC -DPIC -o .libs/foo.o
     gcc -g -O -c foo.c -o foo.o >/dev/null 2>&1
     burger$

   Note that Libtool automatically created '.libs' directory upon its
first execution, where PIC library object files will be stored.

   Since 'burger' supports shared libraries, and requires PIC objects to
build them, Libtool has compiled a PIC object this time, and made a note
of it in the libtool object:

     # foo.lo - a libtool object file
     # Generated by ltmain.sh (GNU libtool) 2.4.7
     #
     # Please DO NOT delete this file!
     # It is necessary for linking the library.

     # Name of the PIC object.
     pic_object='.libs/foo.o'

     # Name of the non-PIC object.
     non_pic_object='foo.o'

   Notice that the second run of GCC has its output discarded.  This is
done so that compiler warnings aren't annoyingly duplicated.  If you
need to see both sets of warnings (you might have conditional code
inside '#ifdef PIC' for example), you can turn off suppression with the
'-no-suppress' option to libtool's compile mode:

     burger$ libtool --mode=compile gcc -no-suppress -g -O -c hello.c
     gcc -g -O -c hello.c  -fPIC -DPIC -o .libs/hello.o
     gcc -g -O -c hello.c -o hello.o
     burger$