Filenames vs Compilation Names

["kgamble" <kgamble@ricochet.net>]

It appears that gnat.adc (useful when filenames and unit names do not
match) only works when all sourcefiles are stored in a common directory.

I am porting a large Ada program to OS2 using GNAT 3.09. Files are
organized into many subdirectories and usually have filenames that do not
match compilation names. In the GNAT documentation, the work around is to
use Source_File_Name pragmas stored in a file named gnat.adc

Even though this appears to work when compiling files that are in the same
subdirectory as the gnat.adc file, it doesn't appear to work for files
outside the subdirectory. That is, a compilation unit having a "with
clause" for a unit stored in another subdirectory, the compiler will not
check the gnat.adc for remapping of the filenames. I would have thought
that the compiler would be capable of searching gnat.adc files stored in
other directories. 

Has anyone had any success with using gnat.adc for files stored in
different directories?