Program transformation

About: Program transformation is a research topic. Over the lifetime, 2468 publications have been published within this topic receiving 73415 citations.

A fold/unfold transformation framework for rewrite theories extended to CCT

Abstract: Many transformation systems for program optimization, program synthesis, and program specialization are based on fold/unfold transformations. In this paper, we present a fold/unfold-based transformation framework for rewriting logic theories which is based on narrowing. For the best of our knowledge, this is the first fold/unfold transformation framework which allows one to deal with functions, rules, equations, sorts, and algebraic laws (such as commutativity and associativity). We provide correctness results for the transformation system w.r.t. the semantics of ground reducts. Moreover, we show how our transformation technique can be naturally applied to implement a Code Carrying Theory (CCT) system. CCT is an approach for securing delivery of code from a producer to a consumer where only a certificate (usually in the form of assertions and proofs) is transmitted from the producer to the consumer who can check its validity and then extract executable code from it. Within our framework, the certificate consists of a sequence of transformation steps which can be applied to a given consumer specification in order to automatically synthesize safe code in agreement with the original requirements. We also provide an implementation of the program transformation framework in the high-performance, rewriting logic language Maude which, by means of an experimental evaluation of the system, highlights the potentiality of our approach.

Method and system for program transformation using flow-sensitive type constraint analysis

Abstract: A method for analyzing a program is provided. The method includes, determining an object type that may exist at an execution point of the program, wherein this enables determination of possible virtual functions that may be called; creating a call graph at a main entry point of the program; and recording an outgoing function call within a main function. The method also includes analyzing possible object types that may occur at any given instruction from any call path for virtual calls, wherein possible object types are determined by tracking object types as they pass through plural constructs; and calling into functions generically for handling specialized native runtime type information.

Set-Based Analysis for Logic Programming and Tree Automata

Abstract: Compile-time program analysis aims to extract from a program properties useful for efficient implementations and sofware verification. A property of interest is the computational semantics of a program. For decidability reasons, only an approximation of this semantics can be computed. Set-based analysis [Hei92a] provides an elegant and accurate method for this. In the logic programming framework, this computation can be related to type inference [MR85]. In [FSVY91], a simpler presentation based on program transformation and algorithms on alternating tree automata is proposed. Unfortunately, the authors focussed on type checking (i.e. a membership test to the approximate semantics). We propose in this paper a new method to achieve set-based analysis reusing the main transformation described in [FSV Y91]. The main tool for both computation and representation of the result of set-based analysis is tree automata. This leads to a global and coherent presentation of the problem of set-based analysis combined with the simplicity of [FSVY91]. We obtain also a complexity characterization for the problem and our method. We expect that this tree automaton approach will lead to an efficient implementation, contrary to the first conclusions of [FSVY91].

Generating Data Analysis Programs from Statistical Models

Abstract: Extracting information from data, often also called data analysis, is an important scientific task. Statistical approaches, which use methods from probability theory and numerical analysis, are well-founded but difficult to implement: the development of a statistical data analysis program for any given application is time-consuming and requires knowledge and experience in several areas. In this paper, we describe AUTOBAYES, a high-level generator system for data analysis programs from statistical models. A statistical model specifies the properties for each problem variable (i.e., observation or parameter) and its dependencies in the form of a probability distribution. It is thus a fully declarative problem description, similar in spirit to a set of differential equations. From this model, AUTOBAYES generates optimized and fully commented C/C++ code which can be linked dynamically into the Matlab and Octave environments. Code is generated by schema-guided deductive synthesis. A schema consists of a code template and applicability constraints which are checked against the model during synthesis using theorem proving technology. AUTOBAYES augments schema-guided synthesis by symbolic-algebraic computation and can thus derive closed-form solutions for many problems. In this paper, we outline the AUTOBAYES system, its theoretical foundations in Bayesian probability theory, and its application by means of a detailed example.

Relations and attributes: A symbiotic basis for editing environments

Abstract: The ability to generate language-based editors depends on the existence of a powerful, language-independent model of editing. A model is proposed in which programs are represented as attributed abstract-syntax trees with an associated relational database. Relations can depend on the state of the attributed tree, and attributes can depend on the values in relations, provided there are no circular dependencies. The power and the limitations of relational operations are demonstrated with respect to the support of static-semantic checking, anomaly detection, an interrogation facility, and the ability to define alternate views of a program. The advantages of the hybrid system over both the purely relational and purely attribute-based systems are presented, and a prototype implementation of an editor generator is discussed. New algorithms are given for query evaluation and incremental view updating motivated by the efficiency requirements of interactive editing under the defined model.