6.1.5 Library Project Files
When `gnatmake' is invoked with a main project file that is a library
project file, it is not allowed to specify one or more mains on the command
line.
When a library project file is specified, switches -b and
-l have special meanings.
- -b is only allowed for stand-alone libraries. It indicates
to `gnatmake' that `gnatbind' should be invoked for the
library.
- -l may be used for all library projects. It indicates
to `gnatmake' that the binder generated file should be compiled
(in the case of a stand-alone library) and that the library should be built.