1,971 papers · page 43 of 99
We present a method for example-guided synthesis of functional programs over recursive data structures. Given a set of input-output examples, our method synthesizes a program in a functional language with higher-order combinators like map and fold. The synthesized program is guar…
We report on a machine-checked verification of safety for a state-of-the-art, on-the-fly, concurrent, mark-sweep garbage collector that is designed for multi-core architectures with weak memory consistency. The proof explicitly incorporates the relaxed memory semantics of x86 mul…
We present a complete method for synthesizing lexicographic linear ranking functions (and thus proving termination), supported by inductive invariants, in the case where the transition relation of the program includes disjunctions and existentials (large block encoding of control…
We present a ``negative'' semantics of the C11 language---a semantics that does not just give meaning to correct programs, but also rejects undefined programs. We investigate undefined behavior in C and discuss the techniques and special considerations needed for formally specify…
We present maximal causality reduction (MCR), a new technique for stateless model checking. MCR systematically explores the state-space of concurrent programs with a provably minimal number of executions. Each execution corresponds to a distinct maximal causal model extracted fro…
Writing a parser remains remarkably painful. Automatic parser generators offer a powerful and systematic way to parse complex grammars, but debugging conflicts in grammars can be time-consuming even for experienced language designers. Better tools for diagnosing parsing conflicts…
We present PIDGIN, a program analysis and understanding tool that enables the specification and enforcement of precise application-specific information security guarantees. PIDGIN also allows developers to interactively explore the information flows in their applications to devel…
The ISO C standard does not specify the semantics of many valid programs that use non-portable idioms such as integer-pointer casts. Recent efforts at formal definitions and verified implementation of the C language inherit this feature. By adopting high-level abstract memory mod…
Stream programming languages employ FIFO (first-in, first-out) semantics to model data channels between producers and consumers. A FIFO data channel stores tokens in a buffer that is accessed indirectly via read- and write-pointers. This indirect token-access decouples a producer…
We present a general theory of serializability, unifying a wide range of transactional algorithms, including some that are yet to come. To this end, we provide a compact semantics in which concurrent transactions PUSH their effects into the shared view (or UNPUSH to recall effect…
A hierarchical program is one with multiple procedures but no loops or recursion. This paper studies the problem of deciding reachability queries in hierarchical programs where individual statements can be encoded in a decidable logic (say in SMT). This problem is fundamental to …
Techniques for proving termination and non-termination of imperative programs are usually considered as orthogonal mechanisms. In this paper, we propose a novel mechanism that analyzes and proves both program termination and non-termination at the same time. We first introduce th…
Despite decades of research on parsing, the construction of parsers remains a painstaking, manual process prone to subtle bugs and pitfalls. We present a programming-by-example framework called Parsify that is able to synthesize a parser from input/output examples. The user does …
We address the compiler correctness problem for many-core systems through novel applications of fuzz testing to OpenCL compilers. Focusing on two methods from prior work, random differential testing and testing via equivalence modulo inputs (EMI), we present several strategies fo…
Self-timed chip designs are commonly specified in a high-level message-passing language called CHP. This language is closely related to Hoare's CSP except it admits erroneous behavior due to the necessary limitations of efficient hardware implementations. For example, two process…
Compilers should not miscompile. Our work addresses problems in developing peephole optimizations that perform local rewriting to improve the efficiency of LLVM code. These optimizations are individually difficult to get right, particularly in the presence of undefined behavior; …
Energy harvesting enables novel devices and applications without batteries, but intermittent operation under energy harvesting poses new challenges to memory consistency that threaten to leave applications in failed states not reachable in continuous execution. This paper present…
We present Symbiosis: a concurrency debugging technique based on novel differential schedule projections (DSPs). A DSP shows the small set of memory operations and data-flows responsible for a failure, as well as a reordering of those elements that avoids the failure. To build a …
Runtime metaprogramming enables many useful applications and is often a convenient solution to solve problems in a generic way, which makes it widely used in frameworks, middleware, and domain-specific languages. However, powerful metaobject protocols are rarely supported and eve…
Software-defined networking (SDN) is revolutionizing the networking industry, but current SDN programming platforms do not provide automated mechanisms for updating global configurations on the fly. Implementing updates by hand is challenging for SDN programmers because networks …