PADS is a declarative data description language that allows data analysts to describe both the physical layout of ad hoc data sources and semantic properties of that data. From such descriptions, the PADS compiler gen...
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PADS is a declarative data description language that allows data analysts to describe both the physical layout of ad hoc data sources and semantic properties of that data. From such descriptions, the PADS compiler generates libraries and tools for manipulating the data, including parsing routines, statistical profiling tools, translation programs to produce well-behaved formats such as XML or those required for loading relational databases, and tools for running XQueries over raw PADS data sources. The descriptions are concise enough to serve as "living" documentation while flexible enough to describe most of the ASCII, binary, and Cobol formats that we have seen in practice. The generated parsing library provides for robust, application-specific error handling.
A new visual notation is proposed for precisely expressing constraints on object-oriented models, as an alternative to mathematical logic notation used in methods such as Syntropy and Catalysis. The notation is potent...
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A new visual notation is proposed for precisely expressing constraints on object-oriented models, as an alternative to mathematical logic notation used in methods such as Syntropy and Catalysis. The notation is potentially intuitive, expressive, integrates well with existing visual notations, and has a clear and unambiguous semantics. It is reminiscent of informal diagrams used by mathematicians for illustrating relations, and borrows much from Venn diagrams. It may be viewed as a generalization of instance diagrams.
We present FLIX, a declarative programminglanguage for specifying and solving least fixed point problems, particularly static program analyses. FLIX is inspired by Datalog and extends it with lattices and monotone fu...
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ISBN:
(纸本)9781450342612
We present FLIX, a declarative programminglanguage for specifying and solving least fixed point problems, particularly static program analyses. FLIX is inspired by Datalog and extends it with lattices and monotone functions. Using FLIX, implementors of static analyses can express a broader range of analyses than is currently possible in pure Datalog, while retaining its familiar rule-based syntax. We define a model-theoretic semantics of FLIX as a natural extension of the Datalog semantics. This semantics captures the declarative meaning of FLIX programs without imposing any specific evaluation strategy. An efficient strategy is semi-naive evaluation which we adapt for FLIX. We have implemented a compiler and runtime for FLIX, and used it to express several well-known static analyses, including the IFDS and IDE algorithms. The declarative nature of FLIX clearly exposes the similarity between these two algorithms.
Recent work on alias analysis in the presence of pointers has concentrated on context-sensitive interprocedural analyses, which treat multiple calls to a single procedure independently rather than constructing a singl...
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ISBN:
(纸本)9780897916974
Recent work on alias analysis in the presence of pointers has concentrated on context-sensitive interprocedural analyses, which treat multiple calls to a single procedure independently rather than constructing a single approximation to a procedure's effect on all of its callers. While context-sensitive modeling offers the potential for greater precision by considering only realizable call-return paths, its empirical benefits have yet to be measured. This paper compares the precision of a simple, efficient, context-insensitive points-to analysis for the C programminglanguage with that of a maximally context-sensitive version of the same analysis. We demonstrate that, for a number of pointer-intensive benchmark programs, context-insensitivity exerts little to no precision penalty. We also describe techniques for using the output of context-insensitive analysis to improve the efficiency of context-sensitive analysis without affecting precision.
Network operators often need to ensure that important probabilistic properties are met, such as that the probability of network congestion is below a certain threshold. Ensuring such properties is challenging and requ...
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ISBN:
(纸本)9781450356985
Network operators often need to ensure that important probabilistic properties are met, such as that the probability of network congestion is below a certain threshold. Ensuring such properties is challenging and requires both a suitable language for probabilistic networks and an automated procedure for answering probabilistic inference queries. We present BAYONET, a novel approach that consists of: (i) a probabilistic network programminglanguage and (ii) a system that performs probabilistic inference on BAYONET programs. The key insight behind BAYONET is to phrase the problem of probabilistic network reasoning as inference in existing probabilistic languages. As a result, BAYONET directly leverages existing probabilistic inference systems and offers a flexible and expressive interface to operators. We present a detailed evaluation of BAYONET on common network scenarios, such as network congestion, reliability of packet delivery, and others. Our results indicate that BAYONET can express such practical scenarios and answer queries for realistic topology sizes (with up to 30 nodes).
We propose an aspect-oriented programming (AOP) language called Aspectual Caml based on a strongly-typed functional language Objective Caml with two AOP mechanisms similar to those in AspectJ language. This paper desc...
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ISBN:
(纸本)9781595930644
We propose an aspect-oriented programming (AOP) language called Aspectual Caml based on a strongly-typed functional language Objective Caml with two AOP mechanisms similar to those in AspectJ language. This paper describes the design and implementation issues of those AOP mechanisms that give us insights into the interaction between AOP features and common features in strongly-typed functional languages such as type inference, polymorphic types and curried functions. We implemented a prototype compiler of the language and used the language for separating crosscutting concerns in application programs, including for separating descriptions of a type system from compiler descriptions.
We propose a new language-based approach to mitigating timing channels. In this language, well-typed programs provably leak only a bounded amount of information over time through external timing channels. By incorpora...
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ISBN:
(纸本)9781450312059
We propose a new language-based approach to mitigating timing channels. In this language, well-typed programs provably leak only a bounded amount of information over time through external timing channels. By incorporating mechanisms for predictive mitigation of timing channels, this approach also permits a more expressive programming model. Timing channels arising from interaction with underlying hardware features such as instruction caches are controlled. Assumptions about the underlying hardware are explicitly formalized, supporting the design of hardware that efficiently controls timing channels. One such hardware design is modeled and used to show that timing channels can be controlled in some simple programs of real-world significance.
Many program analyses can be reduced to graph reachability problems involving a limited form of context-free language reachability called Dyck-CFL reachability. We show a new reduction from Dyck-CFL reachability to se...
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Many program analyses can be reduced to graph reachability problems involving a limited form of context-free language reachability called Dyck-CFL reachability. We show a new reduction from Dyck-CFL reachability to set constraints that can be used in practice to solve these problems. Our reduction is much simpler than the general reduction from context-free language reachability to set constraints. We have implemented our reduction on top of a set constraints toolkit and tested its performance on a substantial polymorphic flow analysis application.
We discuss the design and implementation of a compiler that translates formulas representing signal processing transforms into efficient C or Fortran programs. The formulas are represented in a language that we call S...
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ISBN:
(纸本)9781581134148
We discuss the design and implementation of a compiler that translates formulas representing signal processing transforms into efficient C or Fortran programs. The formulas are represented in a language that we call SPL, an acronym from Signal Processing language. The compiler is a component of the SPIRAL system which makes use of formula transformations and intelligent search strategies to automatically generate optimized digital signal processing (DSP) libraries. After a discussion of the translation and optimization techniques implemented in the compiler, we use SPL formulations of the fast Fourier transform (FFT) to evaluate the compiler. Our results show that SPIRAL, which can be used to implement many classes of algorithms, produces programs that perform as well as "hard-wired" systems like FFTW.
This paper evaluates the design and implementation of Omniware: a safe, efficient, and language-independent system for executing mobile program modules. Omniware uses software fault isolation to achieve a unique combi...
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ISBN:
(纸本)9780897917957
This paper evaluates the design and implementation of Omniware: a safe, efficient, and language-independent system for executing mobile program modules. Omniware uses software fault isolation to achieve a unique combination of language-independence and excellent performance. Software fault isolation uses only the semantics of the underlying processor to determine whether a mobile code module can corrupt its execution environment. This separation of programminglanguageimplementation from program module safety enable mobile system to use a radically simplified virtual machine as its basis for portability.
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