CIL (C Intermediate Language)

CIL is a front-end for the C programming language that facilitates program analysis and transformation. CIL will parse and typecheck a program, and compile it into a simplified subset of C. For example, in CIL all looping constructs are given a single form and expressions have no side-effects. This reduces the number of cases that must be considered when manipulating a C program. CIL has been used for a variety of projects, including CCured, a tool that makes C programs memory safe.

CIL supports ANSI C as well as most of the extensions of the GNU C and Microsoft C compilers. A Perl script acts as a drop in replacement for either gcc or Microsoft's cl, and allows merging of the source files in your project. Other features include support for control-flow and points-to analyses.


CIL is maintained by Gabriel Kerneis <>