Is there any treeherder / taskcluster job, that checks that committed code matches what clang-format produces? Could we have such a job, that's also executed for try-comm-central builds?

For mozilla-central, I think it's handled by getting nagged about it when phabricator checks the patch.

This is quite an ambitious project since not even M-C have automated checking, apart from perhaps in Phab, although that seems unlikely if you read on. They reformat manually in bug 1519636 (and occasionally bust things, see bug 1519636 comment #67).

NSS executes it as a build job:
https://treeherder.mozilla.org/#/jobs?repo=nss&revision=fb7a589a069404bc20e88fbfd73895b90e001831

So if I understand correctly, right now, if I check in unformatted code, nobody might notice.

There's a clang-format lint task that runs on try pushes for Mozilla code. Phabricator also runs it whenever someone submits a patch involving C/C++ code. The output from these jobs is a json file, which Phab must be reading and reporting on in some sensible way.

There's a number of source code linting type tasks that run that should probably be ported over.

Depends on D132807

Pushed by geoff@darktrojan.net:
https://hg.mozilla.org/comm-central/rev/ecacc921eb8f
Add third-party MAPI headers to .clang-format-ignore. r=darktrojan
https://hg.mozilla.org/comm-central/rev/d88e84d81280
Run clang-format for Thunderbird code in CI. r=darktrojan