The genren.pl script is used to generate source/common/unicode/urename.h header file, which is needed for renaming the ICU exported names. 

This script is intended to be used on Linux, although it should work on any platform that has Perl and nm command.

The following instructions are for Linux version.
- urename.h file should be generated after implementation is complete for a release.
- the version number for a release should be set according to the list in source/common/unicode/uversion.h
- source/common/unicode/umachine.h header should be edited to comment out #include "unicode/urename.h" line. THIS CHANGE SHOULD NOT BE COMMITED BACK TO CVS.
- ICU library should be built and installed.
- Layout engine should be built and installed (it is not currently built by default)
- In the directory where ICU libraries are installed, run 
genren.pl libicuuc.so libicui18n.so libiculayout.so
this will produce the urename.h header file
- copy urename.h to source/common/unicode directory, overwriting the old version. Commit it.
- Unedit changes to umachine.h