[PATCH] D133249: [libc++] Documents details of the pre-commit CI.

Mon Sep 5 12:50:03 PDT 2022

mstorsjo added inline comments.

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Comment at: libcxx/docs/Contributing.rst:119
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+Unless specified otherwise the ``main`` version of Clang is used.
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Mordante wrote:
> mstorsjo wrote:
> > I don't understand this paragraph - each CI run is run through the configured set of supported Clang versions - not only `main`? Or does this talk about specifics about manually running tests with the Docker image?
> This is the version of Clang in the main branch. How about:
> `Unless specified otherwise the nightly build of Clang from the ``main`` branch is used.`
I still don't quite understand what this tries to say. "Unless specified otherwise" - where would I specify a different preference, when I upload a patch and it gets run through CI?

There's three different concepts involved here:
- The CI build matrix (buildkite-pipeline.yml) which specifies a bunch of different versions of tools and standards to run the tests on. Here you can't specify a different preference - all of them are run (unless you edit the file in your patch).
- The Docker images, where the default `clang` executable is a recent nightly build, but older releases are available as `clang-<version>`
- The `run-buildbot` script, which just uses whatever compiler is set as default (via e.g. the `CXX` env var).

So, what about these three concepts is this paragraph trying to say - the second or the third point? This really needs to specify what it talks about - build matrix, docker images or run-buildbot script.

The same thing goes for the following paragraph.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133249/new/

https://reviews.llvm.org/D133249