Introduction
Software building is the process that converts and integrates source code,
libraries, and other required data in a software project into standalone
deliverables and executable files. The build process is managed by a build tool,
i.e. a program that coordinates and controls other programs. A build tool needs
to execute the build commands according to the rules specified in build files,
which are written in a build language supported by the tool. Popular build tools
are GNU make, ant, and
maven.
SYMake is an infrastructure and tool for the analysis
of build code in GNU make. With a specific input
environment, make first evaluates a Makefile into a dependency graph among concrete
file names and commands. Then, it executes the commands with those files.
With such dynamic nature in make’s evaluation, it is
challenging for developers to understand and maintain over time multiple large,
complex, and dependent Makefiles. In brief, the dependency analysis for the
build rules and the name analysis for the entity names are difficult. Thus, it
is challenging to detect those Make-specific code smells and to automate
refactorings in the static Make code before evaluation phase. Even automatic
renaming in Make code is not straightforward as in product code.
We have used SYMake to develop algorithms and a tool
to detect several types of code smells and errors in Makefiles, e.g. loops of
recursive variables, cyclic dependencies, duplicate prerequisites, rule
inclusion. Another SYMake’s application is a renaming tool for Makefile’s
variables/targets whose names might be fragmented and come from multiple
substrings.
Existing tools such as MAKAO (http://sailhome.cs.queensu.ca/~bram/makao/index.html)
can only work on concrete dependency graph for a Makefile, thus it cannot
support renaming/extracting, and code smell detections for Make code as in
SYMake.
