A CIL Tutorial - Department of Computer Science - ETH Zürich

CHAPTER 11. PROGRAM VERIFICATION 102
$ ciltutcc --enable-tut11 --prover=Alt-Ergo prover-version=0.94 -o tut11 test/tut11.c
11.3 Exercises
1. Use a chain of Why3 if-then-else terms to calculate the VC for C's switch statement.
2. Handle structure elds.
3. Verify an array sorting function.
4. Extend the translation of attribute parameters and terms to handle not only integer arithmetic,
but also oating point arithmetic. To achieve this, the relevant theory must be added to the
Why3 context, and the operations from these theories must be added to the ops type.
5. Extend the checking here to also verify that function preconditions are satised.
Project: Create a tool that nds loop invariants given a post-condition and
pre-condition for the loop. There are several approaches you might take. You
could execute the program symbolically at the same time as it executes concretely
(which we'll see how to do in Chapter 15), and assume to be symbolic
invariants relationships that are concretely true at runtime. Alternately, you
could repeatedly construct trial invariants out of every relationship among
program variables that are live in the loop.