$ equery depgraph -A =media-gfx/freecad-0.13.1830-r1
 * Searching for freecad0.13.1830-r1 in media-gfx ...

 * dependency graph for media-gfx/freecad-0.13.1830-r1
 `--  media-gfx/freecad-0.13.1830-r1  ~amd64
   `--  dev-cpp/eigen-3.0.6  amd64
   `--  dev-games/ode-0.12  amd64
   `--  dev-libs/boost-1.52.0-r6  amd64
   `--  dev-libs/libf2c-20110801-r3  amd64
   `--  dev-libs/libspnav-0.2.2  amd64  [X]
   `--  dev-libs/xerces-c-3.1.1-r1  amd64  [icu]
   `--  dev-python/matplotlib-1.3.0  amd64
   `--  dev-qt/qtgui-4.8.5-r1  amd64
   `--  dev-qt/qtopengl-4.8.5  amd64
   `--  dev-qt/qtsvg-4.8.5  amd64
   `--  dev-qt/qtwebkit-4.8.5  amd64
   `--  dev-qt/qtxmlpatterns-4.8.5  amd64
   `--  media-libs/SoQt-1.5.0-r1  [~amd64 keyword]
   `--  media-libs/coin-3.1.3-r2  amd64  [doc]
   `--  sci-libs/gts-20121130  [~amd64 keyword]
   `--  sci-libs/opencascade-6.7.0  [~amd64 keyword]
   `--  sys-libs/zlib-1.2.8-r1  amd64
   `--  virtual/glu-9.0-r1  amd64
   `--  dev-lang/python-2.6.8-r3  amd64
   `--  dev-lang/python-2.7.5-r3  amd64
   `--  dev-lang/python-exec-2.0.1-r1  amd64  [python_targets_python2_6(-)? python_targets_python2_7(-)? python_single_target_python2_6(+)? python_single_target_python2_7(+)?]
   `--  dev-lang/swig-2.0.9  amd64
   `--  sys-devel/make-3.82-r4  amd64
   `--  dev-util/cmake-2.8.12.2  amd64
   `--  sys-apps/findutils-4.4.2-r1  amd64
   `--  virtual/fortran-0  amd64
   `--  dev-qt/assistant-4.8.5  amd64
   `--  dev-python/pycollada-9999  [missing keyword]
   `--  dev-python/pivy-9999  [missing keyword]
   `--  dev-python/PyQt4-4.10.3-r2  amd64  [svg]
   `--  dev-python/pyopencl-9999  [missing keyword]
   `--  dev-python/numpy-1.8.0-r1  amd64
[ media-gfx/freecad-0.13.1830-r1 stats: packages (33), max depth (1) ]

$ cat /etc/portage/package.use/freecad
media-libs/coin doc threads
sys-devel/llvm clang video_cards_radeon
dev-libs/boost python threads
media-libs/mesa opencl
dev-libs/xerces-c threads