Some Thoughts on Build Systems

Note: You might also want to read Some Thoughts on Build Servers, which discusses software packages for running automated builds on a shared server.

SmokestacksThe hardest part of software development is often the road from code in a repo to an artifact in the user’s hands.

There are a million ways you can ruin yourself along that long and winding path. You miss a DLL or dependency. You mark a flag wrong and it won’t run on a non-developer system. A setting gets changed on the system doing the compile and builds mysteriously fail. On multiple platforms (and who isn’t on at least a couple?), you forget to test on all 5 of your platforms and find out the build is broken – obviously or subtly – on one of them.

One building bock that helps cut down on this pain is a build tool – a tool to manage what files are built in what order and with what settings. If you can fire off your build from a single command line command, it dramatically reduces the risk of breakage due to outside factors – and helps a lot with setting up build boxes. At this point I’ve worked with nearly every option: make, msbuild, xcodebuild, rake, Maven, Ant, CMake, premake, qmake, and even a couple of home brew systems. Here are my thoughts on each of them:

GNU Make. The granddaddy of all build tools. Cryptic syntax, most widely used on POSIX-compatible environments like Mac or Linux. It can do anything you want it to, if you’re willing to dive deep enough into it. Provides very little hand holding. Tools like automake and autoconf expand capabilities quite a bit, but they are anything but intuitive, and if your goal isn’t a UNIX command line tool, they may be frustrating to work with. Makefiles are generally shippable if you are willing to put enough smarts in them (since they are fundamentally built on top of the shell). Make files are easy to generate, and many tools exist to programmatically do so (more on those later).

MSBuild. The successor to nmake (with a brief detour to devenv.exe), it owes a lot of its legacy to make. However, it’s fully integrated with Visual Studio, so if you have a Visual Studio project, it’s easy to drive. In general, vcprojs are pretty easy to programmatically generate, and also easy ship to other Windows developers, which is a big bonus. No viability for sharing cross platform, except possibly in the context of Mono development.

XCodeBuild. The command line tool for compiling XCode projects. It works just like XCode does, minus the goofy UI. Great for doing OSX/iOS builds, nothing doing for any other platforms. XCode project files are relatively easy to ship to people, although there can sometimes be little subtleties that screw you up. Once nice thing about XCode’s build model is that it’s fairly easy to call your own scripts at various points in the build process. The downside is that xcodeproj’s are finicky and hard to generate.

Rake. Ruby is pretty sweet, and Rake builds on it in the Ruby way – that is, with a domain specific language tailored to the task at hand. The downside is that the docs are inscrutable – you pretty much need to be prepared to look at a lot of examples and dive the code to understand it well. But it responds well to hacking and generally gets the job done. Since Rake just sequences commands it works great for non-Ruby projects – it’s basically a much better Make.

Maven. I have seen Maven used very well in real Java projects, and abused heavily in non-Java scenarios. If you grok the Maven way and are prepared to conform to its view of the world, you can get good results. But in general I think it is much more trouble than it’s worth in anything but enterprise Java contexts.

Ant. I’ve used Ant several times on non-Java projects, to good results. Ant is powerful and has some nice capabilities for filtering/selecting actions. However, it also has an obtuse XML syntax that becomes cumbersome in complex build scenarios, and it can be finicky to set up all your Ant tasks properly.

CMake. CMake is ugly, but it’s an effective kind of ugly. The CMake language is gross and its codebase is complex, with important features often being driven by subtle combinations of settings. But the docs are pretty decent, the community is large, and it has good update velocity. It also generates pretty good project files for most IDEs. And it is pretty easy to hook arbitrary commands into key points in the build process, which is a big win. CMake is bad if you want to do a lot of file processing or complex logic, but good for making and running project files that work across many platforms – including iOS and OSX.

premake. Of all these technologies, I most want premake to rock. It uses Lua, which is an easy and low-dependency language, and it has a pretty good set of modules for emitting different projects. Most of the time, projects can be shipped, which is big, too. However, the core generators are finicky, and we had compatibility issues. And development velocity isn’t as high as we’d like. So we ultimately had to drop it. However, I think it’s worth a look again in the future.

QMake. QMake is mostly associated with QT development, and exists to facilitate the preprocessing that QT requires to generate all of its binding + convenience features. It takes a simple configuration language, and can be effective. However, its support for mobile platforms appears to be rudimentary and it does not produce project files – just sequences build commands.

Homebrew. My main experience here was a custom project generation tool I developed at GarageGames. (Ultimately, many others have touched it, and I believe that it is still in use as of this writing.) We decided to go the homebrew route because we needed to ship high quality project files to our customers. None of the existing tools could produce these (premake is now probably the closest). And our existing process of hand-tweaking projects resulted in a lot of broken releases. We ended up using PHP to process hand-written project file templates. It worked because we had a large enough team to be able to spend a few man-months refining it until it was good enough. The main take away from that experience was that it’s not as hard to do as you’d think – it’s just matter of patience and groveling through exemplar build files to learn the format. The real cost is maintaining on-going compatibility with all the different versions of all the IDEs. I hope that someday GarageGames releases this tool as open source.

So, with all those out there to consider – what am I using today? Well, we are using a hybrid of Rake and CMake. We use CMake for all the project generation + compilation, while Rake deals with sequencing calls to CMake and make or xcodebuild or what have you – mostly for the build box’s benefit. Our project targets iOS, Android, Mac, and Windows, and so far this combination has worked out well.

Ultimately, you want a tool that builds from a single command and doesn’t require user intervention to produce final build artifacts. Otherwise, you will be constantly chasing your tail as you move from developer to developer or platform to platform. Any of these tools can achieve this, so it’s a question of choosing the tool or combination of tools that fit your situation the best. Good luck!

Author: Ben Garney

See and @bengarney for details.

6 thoughts on “Some Thoughts on Build Systems”

  1. Very nice write up of all the different options. I am only familiar with Ant so it is interesting to see some of the other options available.

    1. Thanks. It’s always frustrating to explore build options so I thought I would write some notes on it. Note this is primarily from the perspective of C/C++ projects.

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