From Fedora Project Wiki
Packaging of Ada programs
Ada programs in Fedora MUST be compiled, if possible, using the default Ada compiler in Fedora gcc-gnat. As usual, standard Fedora optimization flags %{optflags} MUST be used in the compilation. If possible project SHOULD have makefile and configure script
All Ada include files *.adb and *.ads MUST be placed in the standard include directory: either directly in %{_includedir}, or if headers have general names or upstream recommends having an own directory, in e.g. %{_includedir}/%{name}.
Ada projects files MUST be placed in %{_libdir}/gnat/ directory of if project have several *.gpr files in e.g. %{_libdir}/gnat/%{name}.