2,199 papers · page 43 of 110
In this paper, we develop a novel notion of dependent information flow types. Dependent information flow types fit within the standard framework of dependent type theory, but, unlike usual dependent types, crucially allow the security level of a type, rather than just the structu…
The standard reading of type theory through the lens of category theory is based on the idea of viewing a type system as a category of well-typed terms. We propose a basic revision of this reading: rather than interpreting type systems as categories, we describe them as functors …
Security enforcement mechanisms like execution monitors are used to make sure that some untrusted program complies with a policy. Different enforcement mechanisms have different strengths and weaknesses and hence it is important to understand the qualities of various enforcement …
Software-defined networking (SDN) is a new paradigm for operating and managing computer networks. SDN enables logically-centralized control over network devices through a "controller" --- software that operates independently of the network hardware. Network operators can run both…
We propose algorithms for checking language equivalence of finite automata over a large alphabet. We use symbolic automata, where the transition function is compactly represented using (multi-terminal) binary decision diagrams (BDD). The key idea consists in computing a bisimulat…
We introduce a model for mixed syntactic/semantic approximation of programs based on symbolic finite automata (SFA). The edges of SFA are labeled by predicates whose semantics specifies the denotations that are allowed by the edge. We introduce the notion of abstract symbolic fin…
Current proposals for adding gradual typing to JavaScript, such as Closure, TypeScript and Dart, forgo soundness to deal with issues of scale, code reuse, and popular programming patterns. We show how to address these issues in practice while retaining soundness. We design and im…
We present a new approach for predicting program properties from massive codebases (aka "Big Code"). Our approach first learns a probabilistic model from existing data and then uses this model to predict properties of new, unseen programs.
One of the most studied behavioural equivalences is bisimilarity. Its success is much due to the associated bisimulation proof method, which can be further enhanced by means of "up-to bisimulation" techniques such as "up-to context".
We study algebraic data types in a manifest contract system, a software contract system where contract information occurs as refinement types. We first compare two simple approaches: refinements on type constructors and refinements on data constructors. For example, lists of posi…
This paper presents the design of Zombie, a dependently-typed programming language that uses an adaptation of a congruence closure algorithm for proof and type inference. This algorithm allows the type checker to automatically use equality assumptions from the context when reason…
Homotopy Type Theory is a new field of mathematics based on the recently-discovered correspondence between Martin-Löf's constructive type theory and abstract homotopy theory. We have a powerful interplay between these disciplines - we can use geometric intuition to formulate new …
We develop a new framework of algebraic theories with linear parameters, and use it to analyze the equational reasoning principles of quantum computing and quantum programming languages. We use the framework as follows:
This paper reports on the development of Compositional CompCert, the first verified separate compiler for C.
Building a summary for library code is a common approach to speeding up the analysis of client code. In presence of callbacks, some reachability relationships between library nodes cannot be obtained during library-code summarization. Thus, the library code may have to be analyze…
We propose meta lambda calculus Lambda-* as a basic model of textual substitution via metavariables. The most important feature of the calculus is that every beta-redex can be reduced regardless of whether the beta-redex contains meta-level variables or not. Such a meta lambda ca…
We show that the weak memory model introduced by the 2011 C and C++ standards does not permit many common source-to-source program transformations (such as expression linearisation and "roach motel" reorderings) that modern compilers perform and that are deemed to be correct. As …
String-manipulating programs are an important class of programs with applications in malware detection, graphics, input sanitization for Web security, and large-scale HTML processing. This paper extends prior work on BEK, an expressive domain-specific language for writing string-…
It is often the case that increasing the precision of a program analysis leads to worse results. It is our thesis that this phenomenon is the result of fundamental limits on the ability to use precise abstract domains as the basis for inferring strong invariants of programs. We s…
Changing a program in response to a type error plays an important part in modern software development. However, the generation of good type error messages remains a problem for highly expressive type systems. Existing approaches often suffer from a lack of precision in locating e…