"For each implementation-defined convention identifier, there should be a child package of package Interfaces with the corresponding name. This package should contain any declarations that would be useful for interfacing to the language (implementation) represented by the convention. Any declarations useful for interfacing to any language on the given hardware architecture should be provided directly in
"An implementation supporting an interface to C, COBOL, or Fortran should provide the corresponding package or packages described in the following clauses."
Followed. GNAT provides all the packages described in this section.