1676915 - It would be nice to have some documentation on unified build

Status: RESOLVED FIXED

(Firefox Build System :: General, enhancement, P3)

Description

[Markus Stange [:mstange]]

It would be nice to be able to a link to a small piece of documentation that describes:

• what unified build / unified compilation is, and
• why adding or removing cpp files to a directory can break compilation of unrelated files.

Comment 1

[Simon Giesecke [:sg] [he/him]]

As such, this is not a Firefox-specific question. Elsewhere it is also referred to as "unity build:", and described, e.g., in https://en.wikipedia.org/wiki/Unity_build

Are there questions specific to the implementation in the Firefox Build System that should be answered?

Comment 2

[Markus Stange [:mstange]]

Interesting, I wasn't aware of that wikipedia page. What I'm really looking for is just a short blurb that answers the question "Why is the compiler asking me to make changes to files I didn't touch?", that I can link newcomers to.

Comment 3

[Mitchell Hentges [:mhentges] 🦀]

Attachment: Bug 1676915: Add documentation page about Unified Builds

Describe what unified builds are and how they can cause innocuous
changes to cause unexpected compilation failures.

Comment 4

[Mike Hommey [:glandium]]

Note we're not particularly attached to the term. It could make sense to change.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c5fc2ec859df
Add documentation page about Unified Builds r=firefox-build-system-reviewers,mstange,dmajor DONTBUILD

Comment 6

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/c5fc2ec859df