doxygen

USE flags

• clang - support for sys-devel/clang assisted parsing
• debug - Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
• doc - Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
• dot - allow to create dot graphs using media-gfx/graphviz
• doxysearch - build doxyindexer and doxysearch.cgi
• gui - Enable support for a graphical user interface
• qt5 - Add support for the Qt 5 application and UI framework
• sqlite - Add support for sqlite - embedded sql database
• test - Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)