the mapping file would be something like:

phobos.lib = %@P%/src/    //as a default lib required
tango.lib = %@P%/import/tango // as an another choice for user

myheader.di -> mylib.lib
myanotherlibheader -> myanotherlib.lib


this file could be generated by the compiler when use the compiler to emit header files
and compiling them to a lib

and the first two lines should be added by user, the lib maker