GPERF  generates perfect hash functions for sets of key words.  
A perfect hash function is simply:

          A hash function and a data structure that allows 
          recognition of a key word in a set of words using 
          exactly 1 probe into the data structure.

Output from the GPERF program is used to recognize reserved words in
the GNU C, GNU C++, and GNU Pascal compilers, as well as with the GNU
indent program.

Author: Douglas C. Schmidt

Gperf was bundled with libg++. Now that libg++ has been removed from 
the main tree, some people may find gperf useful.

the 19981006 patch adds the flags needed to rebuild egcs from gperf files.