Visually Supporting Source Code Changes Integration: the Torch Dashboard

International audienceAutomatic and advanced merging algorithms help programmers to merge their modifications in main development repositories. However, there is little support to help release masters (integrators) to take decisions about the integration of published merged changes into the system release. Most of the time, the release master has to read all the changed code, check the diffs to build an idea of a change, and read unchanged code to understand the context of some changes. Such a task can be overwhelming. In this paper we present a dashboard to support integrators getting an overview of proposed changes in the context of object-oriented programming. Our approach named Torch characterizes changes based on structural information, authors and symbolic information. It mixes text-based diff information with visual representation and metrics characterizing the changes. We describe our experiment applying it to Pharo, a large open-source system, and report on the evaluation of our approach by release masters of several open-source projects

Ring: a Unifying Meta-Model and Infrastructure for Smalltalk Source Code Analysis Tools

International audienceSource code management systems record different versions of code. Tool support can then compute deltas between versions. To ease version history analysis we need adequate models to represent source code entities. Now naturally the questions of their definition, the abstractions they use, and the APIs of such models are raised, especially in the context of a reflective system which already offers a model of its own structure. We believe that this problem is due to the lack of a powerful code meta-model as well as an infrastructure. In Smalltalk, often several source code meta-models coexist: the Smalltalk reflective API coexists with the one of the Refactoring Engine or distributed versioning system such as Monticello or Store. While having specific meta-models is an adequate engineered solution, it multiplies meta-models and it requires more maintenance efforts (e.g., duplication of tests, transformation between models), and more importantly hinders navigation tool reuse when meta-models do not offer polymorphic APIs. As a first step to provide an infrastructure to support history analysis, this article presents Ring, a unifying source code meta-model that can be used to support several activities and proposes a unified and layered approach to be the foundation for building an infrastructure for version and stream of change analyses. We re-implemented three tools based on Ring to show that it can be used as the underlying meta-model for remote and off-image browsing, scoping refactoring, and visualizing and analyzing changes. As a future work and based on Ring we will build a new generation of history analysis tools

Visually Characterizing Source Code Changes

International audienceRevision Control Systems (e.g., SVN, Git, Mercurial) include automatic and advanced merging algorithms that help developers to merge their modifications with development repositories. While these systems can help to textually detect conflicts, they do not help to identify the semantic consequences of a change. Unfortunately, there is little support to help release masters (integrators) to take decisions about the integration of changes into the system release. Most of the time, the release master needs to read all the modified code, check the diffs to build an idea of a change, and dig for details from related unchanged code to understand the context and potential impact of some changes. As a result, such a task can be overwhelming. In this article we present a visualization tool to support integrators of object-oriented programs in comprehending changes. Our approach named Torch characterizes changes based on structural informa- tion, authors and symbolic information. It mixes text-based diff information with visual representation and metrics characterizing the changes. The current implementation of our approach analyses Smalltalk programs, and thus we de- scribe our experiments applying it to Pharo, a large open-source system. We also report on the evaluations of our approach by release masters and developers of several open-source projects

Supporting Streams of Changes during Branch Integration

International audienceWhen developing large applications, integrators face the problem of integrating changes between branches or forks. While version control systems provide support for merging changes, this support is mostly text-based, and does not take the program entities into account. Furthermore, there exists no support for assessing which other changes a particular change depends on have to be integrated. Consequently, integrators are left to perform a manual and tedious comparison of the changes within the sequence of their branch and to successfully integrate them. In this paper, we present an approach that analyzes changes within a sequence of changes (stream of changes): such analysis identifies and characterizes dependencies between the changes. The approach identifies changes as autonomous, only used by others, only using other changes, or both. Such a characterization aims at easing the integrator's work. In addition, the approach supports important queries that an integrator otherwise has to perform manually. We applied the approach to a stream of changes representing 5 years of development work on an open- source project and report our experiences

Meta-models and Infrastructure for Smalltalk Omnipresent History

International audienceSource code management systems record different versions of code. Tool support can then com- pute deltas between versions. However there is little support to be able to perform history-wide queries and analysis: for example building slices of changes and identifying their differences since the beginning of the project. We believe that this is due to the lack of a powerful code meta- model as well as an infrastructure. For example, in Smalltalk often several source code meta- models coexist: the Smalltalk reflective API coexists with the one of the Refactoring engine or distributed versioning system. While having specific meta-models is an engineered solution, it hampers meta-models manipulation as it requires more maintenance efforts (e.g., duplication of tests, transformation between models), and more importantly navigation tool reuse. As a first step to solve this problem, this article presents several source code models that could be used to support several activities and proposes an unified and layered approach to be the foundation for building an infrastructure for omnipresent version browsing

Software Integration Questions: A Quantitative Survey

Software is in constant evolution. In a software project, code changes represent bug fixes, enhancements, new features and adaptations due to changing domains. The evolution of a project codebase is usually managed in a revision control system that supports branches. Developers perform code changes in a branch and sometimes such changes are merged into other branch. This activity is called integration.Integration of changes poses substantial challenges. We conducted a survey to evaluate a catalogue of 46 questions about integration. For each question, the participants had to rank the importance and the support that current tools offer.In a period of 5 months we received the responses of 42 developers who integrate changes on very diverse software projects

Supporting Integration Activities in Object-Oriented Applications

Modern software is built by teams of developers that work in a collaborative environment. The goal of this kind of development is that multiple developers can work in parallel. They can alter a set of shared artifacts and inspect and integrate the source code changes of other developers. For example, bug fixes, enhancements, new features or adaptations due to changing environment might be integrated into the system release. At a technical level, a collaborative development process is supported by version control systems. Since these version control systems allow developers to work in their own branch, merging and integration have become an integral part of the development process. These systems use automatic and advanced merging techniques to help developers to merge their modifications in the development repositories. However, these techniques do not guarantee to have a functional system. While the use of branching in the development process offers numerous advantages, the activity of merging and integrating changes is hampered by the lack of comprehensive support to assist developers in these activities. For example, the integration of changes can have an unexpected impact on the design or behavior of the system, leading to the introduction of subtle bugs. Furthermore, developers are not supported when integrating changes across branches (cherry picking), when dealing with branches that have diverged, when finding the dependencies between changes, or when assessing the potential impact of changes. In this dissertation we present an approach that aims at alleviating these problems by providing developers and, more precisely, integrators with semi-automated support for assisted integration within a branch and across branches. We focus on helping integrators with their information needs when understanding and integrating changes by means of characterizations of changes and streams of changes (i.e., sequence of successive changes within a branch) together with their dependencies. These characterizations rely on the first-class representation of systems' histories and changes based on program entities and their relationships rather than on files and text. For this, we provide a family of meta-models (Ring, RingH, RingS and RingC) that offer us the representation of program entities, systems' histories, changes and their dependencies, along with analyses for version comparison, and change and dependency identification. Instances of these meta-models are then used by our proposed tool support to enable integrators to analyze the characterizations and changes. Torch, a visual tool, and JET, a set of tools, actually provide the information needs to assist integration within a branch and across branches by means of the characterization of changes and streams of changes respectively

Software Integration Questions: A Quantitative Survey

Software is in constant evolution. In a software project, code changes represent bug fixes, enhancements, new features and adaptations due to changing domains. The evolution of a project codebase is usually managed in a revision control system that supports branches. Developers perform code changes in a branch and sometimes such changes are merged into other branch. This activity is called integration.Integration of changes poses substantial challenges. We conducted a survey to evaluate a catalogue of 46 questions about integration. For each question, the participants had to rank the importance and the support that current tools offer.In a period of 5 months we received the responses of 42 developers who integrate changes on very diverse software projects