A theory of platform-dependent low-level software

The C language definition leaves the sizes and layouts of types partially unspecified. When a C program makes assumptions about type layout, its semantics is defined only on platforms (C compilers and the underlying hardware) on which those assumptions hold. Previous work on formalizing C-like languages has ignored this issue, either by assuming that programs do not make such assumptions or by assuming that all valid programs target only one platform. In the latter case, the platform's choices are hard-wired in the language semantics. In this paper, we present a practically-motivated model for a C-like language in which the memory layouts of types are left largely unspecified. The dynamic semantics is parameterized by a platform's layout policy and makes manifest the consequence of platform-dependent (i.e., unspecified) steps. A type-and-effect system produces a layout constraint: a logic formula encoding layout conditions under which the program is memory-safe. We prove tha...

• Type: Conference
• Year: 2008
• Where: POPL
• Authors: Marius Nita, Dan Grossman, Craig Chambers
• Keywords: Formula Encoding Layout, POPL 2008, Programming Languages, Verification General Terms