[cfe-dev] Repeated clang-format'ting keeps changing code / use of clang-format in CI

[Sebastian Pipping via cfe-dev]

Hi!


I'm trying to integrate clang-format version 9 with CI in a way that the
CI run only passes if applying clang-format yields the exact same
code, i.e. "git diff --exit-code" returns 0.  The idea is that every
pull request would only pass if clang-format

When trying to put that approach to action with libexpat [1]
I noticed that multiple runs to clang-format do not seem to produce the
same code, at least not with the two version of Clang 9 that I tested
[2], and at least not with libexpat code.

I wonder if that's a known problem, if it's fixed in later versions
of clang-format, if you are aware of workarounds, or if I just need
to say goodbye to combining clang-format and CI for stable style checking.

Thanks in advance!

Best



Sebastian


[1] https://github.com/libexpat/libexpat/pull/293
[2] 9.0.0.9999 commit 28c954cf961a846789a972a8ed179b7108244ae7