WIP: update clang-format for Zephyr

[pabigot]

The goal of #21392 to be able to reduce arguments about style by establishing a baseline policy: if the file content is left unmodified by clang-format, the style is acceptable. Released versions of clang-format lack a configuration option required by Zephyr's style.

clang-format-12 (expected for release this fall) eliminates this gap by adding an option for SpaceBeforeParens that does not introduce a space in FOR_EACH control macro expressions like:

SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&dlci_active_t1_timers, dlci, next, node) { ... }

This branch updates the in-tree .clang-format, which tracks the Linux one, to:

• enable the options that were disabled because they were unavailable to clang-format-4 or clang-format-5
• add Zephyr-specific options not yet upstream (ATT only SpaceBeforeParens: ControlStatementsExceptForEachMacros
• additional updates to remain in sync with Linux

If you are interested in evaluating clang-format as an alternative to uncrustify please try the version in this branch, and propose changes to the configuration, so when clang-12 is released we're able to make progress on #21392.

[pabigot]

git-clang-format is intended to support checking conformance of changes. I'll be evaluating this over the next couple months.

[galak]

Do you know if there is ubuntu package or pre-built binary for the clang-format v12?

[pabigot]

Do you know if there is ubuntu package or pre-built binary for the clang-format v12?

Probably not, since 12 is the next release of the entire system. I did something like the following.

git clone https://github.com/llvm/llvm-project.git
cd llvm-project
mkdir build && cd build
TAG=$(git describe --tags)-$(date +%Y%m%d)
cmake -G Ninja \
  -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" \
  -DCMAKE_INSTALL_PREFIX=/usr/local/llvm-${TAG} \
  -DCMAKE_BUILD_TYPE=Release \
  ../llvm \
  2>&1 | tee cmo
ninja
ninja install
cd /usr/local
rm -f llvm
ln -s llvm-${TAG} llvm
cd bin
ln -s ../llvm/bin/clang-format

[chrta]

Do you know if there is ubuntu package or pre-built binary for the clang-format v12?

It is available in the llvm apt repo now, e.g. for focal via deb http://apt.llvm.org/focal/ llvm-toolchain-focal main, see https://apt.llvm.org/

Edit: I commited the changes after running clang-format-12 on the current master, see lemonbeat@0d578b6

[github-actions]

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[pabigot]

I have no plans to do more with this, so whoever wants to take it on is free to do so.

[github-actions]

This pull request has been marked as stale because it has been open (more than) 60 days with no activity. Remove the stale label or add a comment saying that you would like to have the label removed otherwise this pull request will automatically be closed in 14 days. Note, that you can always re-open a closed pull request at any time.