CIL: Intermediate Language and Tools for Analysis and Transformation of C Programs

Abstract. This paper describes the C Intermediate Language: a highlevel representation along with a set of tools that permit easy analysis and source-to-source transformation of C programs. Compared to C, CIL has fewer constructs. It breaks down certain complicated constructs of C into simpler ones, and thus it works at a lower n abstract-syntax trees. But CIL is also more high-level than typical intermediate languages (e.g., three-address code) designed for compilation. As a result, what we have is a representation that makes it easy to analyze and manipulate C programs, and emit them in a form that resembles the original source. Moreover, it comes with a front-end that translates to CIL not only ANSI C programs but also those using Microsoft C or GNU C extensions. We describe the structure of CIL with a focus on how it disambiguates those features of C that we found to be most confusing for program analysis and transformation. We also describe a whole-program merger based on structur...

• Type: Journal
• Year: 2002
• Where: CC
• Authors: George C. Necula, Scott McPeak, Shree Prakash Rahul, Westley Weimer
• Keywords: CC 2002, Certain Complicated Constructs, Intermediate Languages, Source-to-source Transformation, System Software