dev-util/cflow
C function call hierarchy analyzer
USE Flags
debug
Global: Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see http://www.gentoo.org/proj/en/qa/backtraces.xml
emacs
Global: Adds support for GNU Emacs
nls
Global: Adds Native Language Support (using gettext - GNU locale utilities)