How to build Chromium faster?

Question

Following only the instructions here - https://www.chromium.org/developers/how-tos/get-the-code I have been able to successfully build and get a Chromium executable which I can then run.

So, I have been playing around with the code (adding new buttons to the browser etc.) for learning purposes. So each time I make a change (like adding a new button in the settings toolbar) and I use the ninja command to build it takes over 3 hours to finish before I can run the executable. It builds each and every file again I guess.

I have a decently powerful machine (i7, 8GB RAM) running 64-bit Ubuntu. Are there ways to speed up the builds? (At the moment, I have literally just followed the instructions in the above mentioned link and no other optimizations to speed it up.)

Thank you very very much!

Answer 1

If all you're doing is modifying a few files and rebuilding, ninja will only rebuild the objects that were affected by those files. When you run ninja -C ..., the console displays the number of targets that need to be built. If you're modifying only a few files, that should be ~2000 at the high end (modifying popular header files can touch lots of objects). Modifying a single .cpp would result in rebuilding just that object.

Of course, you still have to relink which can take a very long time. To make linking faster, try using a component build, which keeps everything in separate shared libraries rather than one big onw that needs to be relinked for any change. If you're using GN, add is_component_build=true to gn args out/${build_dir}. For GYP, see this page.

You can also peruse faster linux builds and see if any of those tips apply to you. Unfortunately, Chrome is a massive project so builds will naturally be long. However, once you've done the initial build, incremental builds should be on the order of minutes rather than hours.