Library transformations

While software methodology encourages the use of software libraries and advocates architectures of layered libraries, in practice the composition of libraries is not always seamless and the combination of two well-designed libraries not necessarily well designed, since it could result in suboptimal call sequences, lost functionality, or avoidable overhead. In this paper we introduce Simplicissimus, a framework for rewrite-based source code transformations, that allows for code replacement in a systematic and safe manner. We discuss the design and implementation of the framework and illustrate its functionality with applications in several areas. Simplicissimus is integrated into the Gnu C++ compiler.