[libvirt PATCH 00/10] [RFC] clang-tidy CI integration

[Tim Wiederhake]

"clang-tidy" is a static code analysis tool for c and c++ code. See
https://listman.redhat.com/archives/libvir-list/2021-January/msg01152.html
for some issues found by clang-tidy and more background information.

Meson has support for clang-tidy and generates target named "clang-tidy" if
it finds a ".clang-tidy" configuration file in the project's root directory.

There are some problems with this approach though, with regards to inclusion
in GitLab's CI:

* Single-threaded runtime of a complete scan takes between 95 and 110 minutes,
depending on the enabled checks, which is significantly longer than GitLab's
maximum run time of 60 minutes, after which jobs are aborted.

* Even without this limit on runtime, this new check would double to triple
the run time of the libVirt pipeline in GitLab.

* clang-tidy finds a lot of false positives (see link above for explanation)
and has checks that contradict the libVirt code style (e.g. braces around
blocks). This makes a quite complex configuration in ".clang-tidy" neccessary.

* I was unable to make clang-tidy recognize the settings from the
configuration file for generated files, leading clang-tidy to always add some
checks. These checks were among those that produced false positives.

* The list of enabled / disabled checks in the yaml configuration file is a
quite long string, making it hard to weave in some comments / documentation
on which checks are enabled / disabled for what reason.

This series introduces a new script, "run-clang-tidy.py". This is a
replacement for the script of the same name from clang-tools-extra. It offers
parallel execution, caching of results and a configurable soft-timeout.

Please see the individual commits for more details. Comments welcome.

https://gitlab.com/twiederh/libvirt/-/pipelines/255321968 → "clang-tidy".

Tim

Tim Wiederhake (10):
  clang-tidy: Add a simple runner
  clang-tidy: Run in parallel
  clang-tidy: Filter output
  clang-tidy: Add cache
  clang-tidy: Add timeout
  clang-tidy: Allow timeouts
  clang-tidy: Add shuffle
  clang-tidy: Make list of checks explicit
  clang-tidy: Disable irrelevant and failing checks
  clang-tidy: Add CI integration

 .gitlab-ci.yml            |  88 ++++++
 scripts/run-clang-tidy.py | 557 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 645 insertions(+)
 create mode 100755 scripts/run-clang-tidy.py

-- 
2.26.2