Build System Introduction

Build systems are software tools Links to an external site. designed to automate the process of program compilation. This is very useful when switching machines, IDEs, or architectures. Build systems can help simplify code portability. They come in many flavors. Popular ones include: CMake Links to an external site., SCons Links to an external site., PreMake Links to an external site. and other Links to an external site. make and non-make based systems.

Build System Philosophy

At their core, build systems are a functional based languages mapping a set of source resources (in most cases, files) to a target (executable). The primary assumption of the build system is that each of the build actions are idempotent. That is, each invocation of a build command with the same input and options will create the same output. This assumption allows the build system to memoize the actions that is has already performed, and only perform build actions on resources that have changed.

Basically, you want to have a SOURCE tree (directory) of code that is untouched or dirtied by the IDE or build process.

build-1.png

Look at all the extra files Visual studio created for me. Some are personal preferences, some matter. It is difficult to know which to pack up and which to leave (if you want to move the program between machines). How would this one simple "Hello World" program contained in the main.cpp file be easily compiled in Linux or MacOS under XCode or Eclipse? - Build Systems help us.

 

Dissenting View:

Build Systems often try to meet a variety of secondary goals, which at times might be at odds with each other. And sometimes are just a pain to learn some odd new syntax like CMake forces on you. There is a view that "they are all awful" - which is just as strong as my "they are awesome!".

I personally love SCons the best. But use CMake more since it generally is more popular in many numerical simulation algorithms.

Source:
[1 Links to an external site.] Overview of Build Systems