Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!bellcore!sneaky!hira
From: hira@sneaky.bellcore.com (Hira Agrawal)
Newsgroups: gnu.gcc
Subject: use/def sets of program statements
Message-ID: <17066@bellcore.bellcore.com>
Date: 27 Jun 89 19:48:29 GMT
Sender: news@bellcore.bellcore.com
Reply-To: hira@wind.bellcore.com (Hira Agrawal)
Organization: Bell Communications Research, Morristown NJ
Lines: 19

I need to compute def and use sets of all statements in a C program. 

Def set of a statement is set of all variables (actually l-valued 
expressions) whose values could be modified by that statement. Use
set of a statement is the set of all l-valued expressions whose values 
are used in computing the def-set values of that statement. Def/use
sets of compound statements (if, while, etc.) are computed by taking
the union of def/use sets of all their constituent statements.

What are the possible ways of computing these sets while compiling a
program with gcc? One way could be to do so while parsing the program.
Is there any way I could do the same from RTL code? I am not too
familiar with internals of gcc, so I wish to investigate various
options before starting to code any one. 

I'll appreciate any help in this regard. Thanks.

-- Hira.
   hira@wind.bellcore.com