The compiler creates an XFD for each indexed file in the compiled program when you specify the "-Fx" compile-time option. XFDs are fully portable, and thus no recompilation is necessary if you change hardware. The compiler option "-Fxa" causes the generation of XFDs for indexed, relative and sequential files for use with International character translation only. The compiler option "-Fx3" generates version 3 XFD files for backwards compatibility with older versions of the runtime (index files only).
See Chapter 5 of the ACUCOBOL-GT User's Guide for details on how the XFD files are generated from the COBOL program's FDs.
Creating XFD files at compile time offers two significant advantages:
* Any changes made to the file definitions are automatically included in the data dictionaries when the program is recompiled.
* The effects of all compile-time options, COPY REPLACING, source-code control lines, and Data layout compiler flags (-D..) are reflected correctly in the XFDs.