Xavier Leroy
Professor Of Software Sciences at Académie des sciences
Paris, Ile-de-France
Summary
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Rockstar🎓
Top School
Top expert inFunctional Programming and Formal Verification Technologies
Xavier Leroy is a distinguished computer scientist and Professor of Software Sciences at Collège de France with over 30 years of experience in programming languages, compilers, and formal methods. He is the architect and lead developer of the OCaml language and a principal author of CompCert, a widely cited formally verified C compiler that blends practical engineering with machine-checked correctness. His work spans functional programming, type systems, static analysis and operational semantics, and he routinely bridges theory and low-level implementation details—evident from hands-on contributions to OCaml’s runtime and CompCert’s 64-bit arithmetic and assembler handling. A member of the Académie des sciences and long-time Inria researcher, he also contributes to Coq/ROCQ tooling to improve interoperability between proof assistants and OCaml. Known for making rigorous program proofs usable in production-grade systems, he combines academic leadership with sustained open-source craftsmanship.
31 years of coding experience
25 years of employment as a software developer
B.S and M.S., B.S and M.S. at Ecole normale supérieurePhD, PhD at Université Paris Citépost-doc, post-doc at Stanford University
Github Skills (25)
proof-assistant10
runtimes10
run-time10
c1110
integer-arithmetic10
ocaml10
c1710
low-level-programming10
compiler-design10
coq10
sys10
theorem-proving10
runtime-environment10
assembly9
develop9
Programming languages (12)
Github contributions (5)
ocaml/ocaml
May 1995 - Jan 2023
The core OCaml system: compilers, runtime system, base libraries
Role in this project:
Back-end Developer
Back-end DeveloperContributions:14 releases, 950 reviews, 4879 commits in 28 years 1 month
Contributions summary:Xavier contributed to the OCaml compiler's core system, compilers, runtime, and base libraries, as indicated by the commit messages. Their work primarily involved implementing, improving, and fixing functions within the core OCaml system, including low-level runtime functions. The contributions encompassed modifications to the code, indicating involvement in bug fixes, performance optimization, and potentially feature enhancements.
functional-languagecompilersruntime-systemapllwt
AbsInt/CompCert
Sep 2014 - Jan 2023
The CompCert formally-verified C compiler
Role in this project:Back-end Developer
Back-end DeveloperContributions:23 releases, 18 reviews, 847 commits in 8 years 5 months
Contributions summary:Xavier contributed to the CompCert C compiler by implementing helper functions for 64-bit integer arithmetic and by modifying the compiler's handling of function definitions and memory accesses. They focused on various improvements, including optimizations related to function return values, and the elimination of certain instruction sequences. Their work primarily involved low-level code and the modification of assembler instructions, with an emphasis on compiler performance and correctness.
verifiedcompcertformally-verifiedcompilercoq
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