> You have control of CALL_IT.F90 and STUFF.F90. All you have to make > sure of is that the user-written routine begins with > > INCLUDE 'STUFF.F90' > > which should be easy enough to verify. You have to re-link after the > user-written routine is compiled anyway (unless you are doing some sort > of dynamic linking), so it is not improbable that the source code is > present on your system. Presumably, your library routine is being called by some relatively short driver routine which you modify and recompile regularly. In particular, the name of the user-supplied routine must be supplied at this stage. (Wouldn't it be nice if one could specify this at run time?!) You might as well have a script which not only compiles the driver routine but also verifies that the user-written routine contains the "magic" line above. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%