Title
Certifying graph-manipulating C programs via localizations within data structures
Abstract
We develop powerful and general techniques to mechanically verify realistic programs that manipulate heap-represented graphs. These graphs can exhibit well-known organization principles, such as being a directed acyclic graph or a disjoint-forest; alternatively, these graphs can be totally unstructured. The common thread for such structures is that they exhibit deep intrinsic sharing and can be expressed using the language of graph theory. We construct a modular and general setup for reasoning about abstract mathematical graphs and use separation logic to define how such abstract graphs are represented concretely in the heap. We develop a Localize rule that enables modular reasoning about such programs, and show how this rule can support existential quantifiers in postconditions and smoothly handle modified program variables. We demonstrate the generality and power of our techniques by integrating them into the Verified Software Toolchain and certifying the correctness of seven graph-manipulating programs written in CompCert C, including a 400-line generational garbage collector for the CertiCoq project. While doing so, we identify two places where the semantics of C is too weak to define generational garbage collectors of the sort used in the OCaml runtime. Our proofs are entirely machine-checked in Coq.
Year
DOI
Venue
2019
10.1145/3360597
Proceedings of the ACM on Programming Languages
Keywords
DocType
Volume
CompCert, Coq, Graph-manipulating programs, Separation logic, VST
Journal
3
Issue
Citations 
PageRank 
OOPSLA
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Shengyi Wang111.06
Qinxiang Cao200.68
Anshuman Mohan300.68
Aquinas Hobor424317.42