GenC2Rust: Towards Generating Generic Rust Code from C

Rust provides an exciting combination of strong safety guarantees and high performance. Many new systems are being implemented in Rust. Nevertheless, there is a large body of existing C code that could greatly benefit from Rust's safety guarantees. Unfortunately, the manual effort required to rewrite C code into Rust is often prohibitively expensive. Researchers have explored tools to assist developers in trans-lating legacy C code into Rust code. However, the mismatch between C abstractions and idiomatic Rust abstractions makes it challenging to automatically utilize Rust's language features, resulting in non-idiomatic Rust code that requires extensive manual effort to further refactor. For example, existing tools often fail to map polymorphic uses of void pointers in C to Rust's generic pointers. In this paper, we present a translation tool, GenC2Rust, that translates non-generic C code into generic Rust code. GenC2Rust statically analyzes the use of void pointers in the C program to compute the typing constraints and then retypes the parametric polymorphic void pointers into generic pointers. We conducted an evaluation of GenC2Rust across 42 C programs that vary in size and span multiple domains to demonstrate its scalability as well as correctness. We discovered GenC2Rust has translated 4,572 void pointers to use generics. We also discuss the limiting factors encountered in the translation process.