Analysis of Low-Level Code Using Cooperating Decompilers

Analysis or verification of low-level code is useful for minimizing the disconnect between what is verified and what is actually executed and is necessary when source code is unavailable or is, say, intermingled with inline assembly. We present a modular framework for building pipelines of cooperating decompilers that gradually lift the level of the language to something appropriate for source-level tools. Each decompilation stage contains an abstract interpreter that encapsulates its findings about the program by translating the program into a higher-level intermediate language. We provide evidence for the modularity of this framework through the implementation of multiple decompilation pipelines for both x86 and MIPS assembly produced by gcc, gcj, and coolc (a compiler for a pedagogical Java-like language) that share several low-level components. Finally, we discuss our experimental results that apply the BLAST model checker for C and the Cqual analyzer to decompiled assembly.