System Specific, Source Code Transformations

International audienceDuring its lifetime, a software system might undergo a major transformation effort in its structure, for example to migrate to a new architecture or bring some drastic improvements to the system. Particularly in this context, we found evidences that some sequences of code changes are made in a systematic way. These sequences are composed of small code transformations (e.g., create a class, move a method) which are repeatedly applied to groups of related entities (e.g., a class and some of its methods). A typical example consists in the systematic introduction of a Factory design pattern on the classes of a package. We define these sequences as transformation patterns. In this paper, we identify examples of transformation patterns in real world software systems and study their properties: (i) they are specific to a system; (ii) they were applied manually; (iii) they were not always applied to all the software entities which could have been transformed; (iv) they were sometimes complex; and (v) they were not always applied in one shot but over several releases. These results suggest that transformation patterns could benefit from automated support in their application. From this study, we propose as future work to develop a macro recorder, a tool with which a developer records a sequence of code transformations and then automatically applies them in other parts of the system as a customizable, large-scale transformation operator

System Specific, Source Code Transformations

International audienceDuring its lifetime, a software system might undergo a major transformation effort in its structure, for example to migrate to a new architecture or bring some drastic improvements to the system. Particularly in this context, we found evidences that some sequences of code changes are made in a systematic way. These sequences are composed of small code transformations (e.g., create a class, move a method) which are repeatedly applied to groups of related entities (e.g., a class and some of its methods). A typical example consists in the systematic introduction of a Factory design pattern on the classes of a package. We define these sequences as transformation patterns. In this paper, we identify examples of transformation patterns in real world software systems and study their properties: (i) they are specific to a system; (ii) they were applied manually; (iii) they were not always applied to all the software entities which could have been transformed; (iv) they were sometimes complex; and (v) they were not always applied in one shot but over several releases. These results suggest that transformation patterns could benefit from automated support in their application. From this study, we propose as future work to develop a macro recorder, a tool with which a developer records a sequence of code transformations and then automatically applies them in other parts of the system as a customizable, large-scale transformation operator

Recording and Replaying System Specific, Source Code Transformations

International audienceDuring its lifetime, a software system is under continuous maintenance to remain useful. Maintenance can be achieved in activities such as adding new features, fixing bugs, improving the system's structure, or adapting to new APIs. In such cases, developers sometimes perform sequences of code changes in a systematic way. These sequences consist of small code changes (e.g., create a class, then extract a method to this class), which are applied to groups of related code entities (e.g., some of the methods of a class). This paper presents the design and proof-of-concept implementation of a tool called MacroRecorder. This tool records a sequence of code changes, then it allows the developer to generalize this sequence in order to apply it in other code locations. In this paper, we discuss MacroRecorder's approach that is independent of both development and transformation tools. The evaluation is based on previous work on repetitive code changes related to rearchitecting. MacroRecorder was able to replay 92% of the examples, which consisted in up to seven code entities modified up to 66 times. The generation of a customizable, large-scale transformation operator has the potential to efficiently assist code maintenance

Merging Application Models in a MDA Based Runtime Environment for Enterprise Information Systems

The issue of merging source code based applications is very problematic, particularly when involving code from disparate sources, due to the typical unsuitability of available source code for software merging. The relatively recent field of model driven architecture is primely involved in the definition and development of the source model structures for model based applications and in developing transformations from the abstract models to various executable formats. The authors are also involved in these MDA activities in the development of their G2 prototype system targeted at the specific domain of enterprise information system style applications. They have reviewed various methods for merging application models within this domain and describe the fundamentals of three application model integration methods from their G2 system; standard element referencing, virtual data element mapping and element envelopment that can be used to provide practical and simple application model merging at both the design time and runtime of a model based production system, to produce a working integrated merged application

Astropy: A Community Python Package for Astronomy

We present the first public version (v0.2) of the open-source and community-developed Python package, Astropy. This package provides core astronomy-related functionality to the community, including support for domain-specific file formats such as Flexible Image Transport System (FITS) files, Virtual Observatory (VO) tables, and common ASCII table formats, unit and physical quantity conversions, physical constants specific to astronomy, celestial coordinate and time transformations, world coordinate system (WCS) support, generalized containers for representing gridded as well as tabular data, and a framework for cosmological transformations and conversions. Significant functionality is under active development, such as a model fitting framework, VO client and server tools, and aperture and point spread function (PSF) photometry tools. The core development team is actively making additions and enhancements to the current code base, and we encourage anyone interested to participate in the development of future Astropy versions

Efficient software development for microprocessor based embedded system.

Tang Tze Yeung Eric.Thesis submitted in: July 2003.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 69-75).Abstracts in English and Chinese.ABSTRACT --- p.IIACKNOWLEDGMENT --- p.IIChapter 1 --- INTRODUCTION --- p.1Chapter 1.1 --- Embedded System --- p.1Chapter 1.2 --- Embedded Processor --- p.1Chapter 1.3 --- Embedded System Design --- p.3Chapter 1.3.1 --- Current Embedded System Design Challenges --- p.3Chapter 1.3.2 --- Embedded System Design Trend --- p.4Chapter 1.4 --- Efficient Software Development for Microprocessor --- p.8Chapter 1.4.1 --- Efficient Software Development Methodology --- p.8Chapter 1.5 --- Thesis Organization --- p.10Chapter 2 --- SOURCE CODE OPTIMIZATION --- p.11Chapter 2.1 --- Source Code Optimization Strategy --- p.11Chapter 2.2 --- Source Code Transformations --- p.12Chapter 2.2.1 --- Strength Reduction --- p.12Chapter 2.2.2 --- Function Inlining --- p.13Chapter 2.2.3 --- Table Lookup --- p.13Chapter 2.2.4 --- Loop Transformations --- p.13Chapter 2.2.5 --- Software Pipelining --- p.15Chapter 2.2.6 --- Register Allocation --- p.17Chapter 2.3 --- Case Study: Source Code Optimization on the StrongARM (SA1110) Platform --- p.18Chapter 2.3.1 --- StrongARM architecture --- p.18Chapter 2.3.2 --- StrongARM pipeline hazard illustration --- p.20Chapter 2.3.3 --- Source Code Optimization on StrongARM --- p.21Chapter 2.3.4 --- Instruction Set Optimization of StrongARM --- p.27Chapter 2.4 --- Conclusion --- p.32Chapter 3 --- FLOAT-TO-FIXED OPTIMIZATION --- p.33Chapter 3.1 --- Introduction to Fixed-point --- p.34Chapter 3.1.1 --- Fixed-point representation --- p.34Chapter 3.1.2 --- Fixed-point implementation --- p.35Chapter 3.1.3 --- Mathematical functions implementation --- p.38Chapter 3.2 --- Case Study: Fingerprint Minutiae Extraction Algorithms on the Strong ARM platform --- p.41Chapter 3.2.1 --- Fingerprint Verification Overview --- p.42Chapter 3.2.2 --- Fixed-point Implementation of Fingerprint Minutiae Extraction Algorithm --- p.49Chapter 3.2.3 --- Experimental Results --- p.51Chapter 3.3 --- Conclusion --- p.56Chapter 4 --- DOMAIN SPECIFIC OPTIMIZATION --- p.57Chapter 4.1 --- Case Study: Font Rasterization on the Strong ARM platform --- p.57Chapter 4.1.1 --- Outline Font --- p.57Chapter 4.1.2 --- Font Rasterization --- p.59Chapter 4.1.3 --- Experiments --- p.63Chapter 4.2 --- Conclusion --- p.66Chapter 5 --- CONCLUSION --- p.67BIBLIOGRAPHY --- p.6

Building a CHS Bathymetric Data Warehouse

The CHS is designing and implementing a Source Database for bathymetric data. To store and manage terabytes of bathymetric information for producing CHS products and providing services to clients requires a fresh approach. The implementation of HHCode (Helical Hyperspatial Code) for storing, analyzing and accessing dense spatial data sets in an Oracle Relational Database Management System (RDBMS) is a key technology used to build the data warehouse. The paper addresses the concepts and applications necessary to manage this data within the data repository. Specific areas addressed are aggregation, attribution, and partitioning of the spatial data. The implementation of an on-line, near-line and off-line model to minimize storage costs is described. The approach used to perform horizontal and vertical datum transformations is discussed

Generating rewritable abstract syntax trees - A foundation for the rapid development of source code transformation tools

Abstract. Building a production-quality refactoring engine or similar source code transformation tool traditionally requires a large amount of hand-written, language-specific support code. We describe a system which reduces this overhead by allowing both a parser and a fully rewritable AST to be generated automatically from an annotated grammar, requiring little or no additional handwritten code. The rewritable AST is ideal for implementing program transformations that preserve the formatting of the original sources, including spacing and comments, and the system can be augmented to allow transformation of Cpreprocessed sources even when the target language is not C or C++. Moreover, the AST design is fully customizable, allowing it to resemble a hand-coded tree. The amount of required annotation is typically quite small, and the annotated grammar is often an order of magnitude smaller than the generated code