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We describe the design of 3CPS, a compiler intermediate representation (IR) we have developed for use in compiling call-by-value functional languages such as SML, OCaml, Scheme, and Lisp. The language is a low-level form designed in tandem with a matching suite of static analyses. It reflects our belief that the core task of an optimising compiler for a functional language is to reason about the environment structure of the program. Our IR is distinguished by the presence of extent annotations, added to all variables (and verified by static analysis). These annotations are defined in terms of the semantics of the IR, but they directly tell the compiler what machine resources are needed to implement the environment structure of each annotated variable.
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Defining and Preserving More C Behaviors: Verified Compilation Using a Concrete Memory Model
We propose a concrete ("pointer as integer") memory semantics for C that supports verified compilation to a target environment having simple "public vs. private" data protection based on tagging or sandboxing (such as the WebAssembly virtual machine). Our semantics gives definition to a range of legacy programming idioms that cause undefined behavior in standard C, and are not covered by existing verified compilers, but that often work in practice. Compiler correctness in this context implies that target programs are secure against all control-flow attacks (although not against data-only attacks). To avoid tying our semantics too closely to particular compiler implementation choices, it is parameterized by a novel form of oracle that non-deterministically chooses the addresses of stack and heap allocations. As a proof-of-concept, we formalize a small RTL-like language and verify two-way refinement for a compiler from this language to a low-level machine and runtime system with hardware tagging. Our Coq formalization and proofs are provided as supplementary material.
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- Award ID(s):
- 2048499
- PAR ID:
- 10595450
- Editor(s):
- Bertot, Yves; Kutsia, Temur; Norrish, Michael
- Publisher / Repository:
- Schloss Dagstuhl – Leibniz-Zentrum für Informatik
- Date Published:
- Volume:
- 309
- ISSN:
- 1868-8969
- ISBN:
- 978-3-95977-337-9
- Page Range / eLocation ID:
- 36:1-36:20
- Subject(s) / Keyword(s):
- Compiler verification C language semantics Coq proof assistant Security and privacy → Logic and verification Software and its engineering → Compilers Software and its engineering → Semantics
- Format(s):
- Medium: X Size: 20 pages; 884469 bytes Other: application/pdf
- Size(s):
- 20 pages 884469 bytes
- Location:
- Proc. 15th International Conference on Interactive Theorem Proving (ITP 24)
- Right(s):
- Creative Commons Attribution 4.0 International license; info:eu-repo/semantics/openAccess
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Conference Paper:
- https://doi.org/10.4230/LIPICS.ITP.2024.36
