Symbiotic 8: Beyond Symbolic Execution (Competition Contribution)

The archive of the tool Symbiotic 8 that was used in the SV-COMP 2021 competition.

Symbiotic 8 extends the traditional combination of static analyses, instrumentation, program slicing, and symbolic execution with one substantial novelty, namely a technique mixing symbolic execution with k-induction. This technique can prove the correctness of programs with possibly unbounded loops, which cannot be done by classic symbolic execution. Symbiotic 8 delivers also several other improvements. In particular, we have modified our fork of the symbolic executor Klee to support the comparison of symbolic pointers. Further, we have tuned the shape analysis tool Predator (integrated already in Symbiotic 7) to perform better on LLVM bitcode. We have also developed a light-weight analysis of relations between variables that can prove the absence of out-of-bound accesses to arrays.