Towards Development with Multi-Version Models: Detecting Merge Conflicts and Checking Well-Formedness

TL;DR

This paper introduces multi-version models based on typed graphs for early conflict detection and well-formedness checking in parallel software development, improving merge conflict management and consistency verification.

Contribution

It presents a novel multi-version graph model that enables conflict detection and well-formedness checking without exhaustive merging of all version pairs.

Findings

Models allow studying well-formedness across all versions simultaneously

Enables conflict detection without pairwise merging

Preliminary experiments show scalability of the approach

Abstract

Developing complex software requires that multiple views and versions of the software can be developed in parallel and merged as supported by views and managed by version control systems. In this context, this paper considers monitoring merging and related consistency problems permanently at the level of models and abstract syntax to permit early and frequent conflict detection while developing in parallel. The presented approach introduces multi-version models based on typed graphs that permit to store changes and multiple versions in one graph in a compact form and allow (1) to study well-formedness for all versions without the need to extract each version individually, (2) to report all possible merge conflicts without the need to merge all pairs of versions, and (3) to report all violations of well-formedness conditions that will result for merges of any two versions independent of any merge decisions without the need to merge all pairs of versions. The paper defines the related concepts and algorithms operating on multi-version models, proves their correctness w.r.t.~the usually employed three-way-merge, and reports on preliminary experiments concerning the scalability.