[PATCH v3 0/8] clang-format: add more rules and enable on CI

This is v3 of my series to add clang-format to the CI.

The series was mostly inspired by a patch sent recently to 'include kh_foreach* macros in ForEachMacros' [1]. I was wondering why we don't run the formatting on CI and reduce some of the workload of reviewers.

We have a '.clang-format' file to provide rules for code formatting. The commits 1-5 aims to add more rules to the file while deprecating old ones.

Commit 6 enables CI action on GitHub and GitLab to also check for the code formatting. Currently, it is allowed to fail. This way we can build confidence and fine tune the values as needed and finally enforce the check in a future patch. I'm not well versed with GitHub workflows, and I mostly tried to copy existing work there. Expecting some feedback in that section!

Commit 7 fixes an existing issue with the 'check-whitespace' job, which is failing as success in the GitLab CI.

Commit 8 adds the `RemoveBracesLLVM` only in the context of the CI. If we decide against it, we could drop this commit from the series.

1: https://lore.kernel.org/git/4e7893f5-2dd9-46cf-8a64-cf780f4e1730@web.de/

Changes against v2:
* Dropped the commit to add 'RemoveBracesLLVM' to the in-tree '.clang-format'.
Now, we only add it in the CI context.
* Added comments for the reasoning and picking of the ENV variables in GitLab's
CI. Also changed the syntax to be more readable.

Karthik Nayak (8):
  clang-format: indent preprocessor directives after hash
  clang-format: avoid spacing around bitfield colon
  clang-format: ensure files end with newlines
  clang-format: replace deprecated option with 'SpacesInParens'
  clang-format: formalize some of the spacing rules
  ci: run style check on GitHub and GitLab
  check-whitespace: detect if no base_commit is provided
  ci/style-check: add `RemoveBracesLLVM` to '.clang-format'

 .clang-format                     | 36 +++++++++++++++++++++++++----
 .github/workflows/check-style.yml | 29 +++++++++++++++++++++++
 .gitlab-ci.yml                    | 38 ++++++++++++++++++++++++++++++-
 ci/check-whitespace.sh            | 10 ++++++--
 ci/install-dependencies.sh        |  2 +-
 ci/run-style-check.sh             | 21 +++++++++++++++++
 6 files changed, 127 insertions(+), 9 deletions(-)
 create mode 100644 .github/workflows/check-style.yml
 create mode 100755 ci/run-style-check.sh

Range-diff against v2:
1:  6cf91ffc86 = 1:  6cf91ffc86 clang-format: indent preprocessor directives after hash
2:  beb002885f = 2:  beb002885f clang-format: avoid spacing around bitfield colon
3:  3031be43e7 = 3:  3031be43e7 clang-format: ensure files end with newlines
4:  bc1550e300 = 4:  bc1550e300 clang-format: replace deprecated option with 'SpacesInParens'
5:  840318a4c9 < -:  ---------- clang-format: avoid braces on simple single-statement bodies
6:  0ecfd8d24b ! 5:  4586c0094b clang-format: formalize some of the spacing rules
    @@ Commit message
         Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
     
      ## .clang-format ##
    -@@ .clang-format: RemoveBracesLLVM: true
    +@@ .clang-format: PointerAlignment: Right
      # x = (int32)y;    not    x = (int32) y;
      SpaceAfterCStyleCast: false
      
7:  11a9ac4935 ! 6:  c18cb23369 ci: run style check on GitHub and GitLab
    @@ .gitlab-ci.yml: check-whitespace:
     +    CC: clang
     +  before_script:
     +    - ./ci/install-dependencies.sh
    ++  # Since $CI_MERGE_REQUEST_TARGET_BRANCH_SHA is only defined for merged
    ++  # pipelines, we fallback to $CI_MERGE_REQUEST_DIFF_BASE_SHA, which should
    ++  # be defined in all pipelines.
     +  script:
     +    - |
    -+      if [ -z ${CI_MERGE_REQUEST_TARGET_BRANCH_SHA} ]; then
    ++      if test -n "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++      then
    ++        ./ci/run-style-check.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++      elif test -n "$CI_MERGE_REQUEST_DIFF_BASE_SHA"
    ++      then
     +        ./ci/run-style-check.sh "$CI_MERGE_REQUEST_DIFF_BASE_SHA"
     +      else
    -+        ./ci/run-style-check.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++        echo "CI_MERGE_REQUEST_DIFF_BASE_SHA should always exist!"; exit 1
     +      fi
     +  rules:
     +    - if: $CI_PIPELINE_SOURCE == 'merge_request_event'
8:  caccbf8264 ! 7:  4d08c570bb check-whitespace: detect if no base_commit is provided
    @@ Commit message
     
      ## .gitlab-ci.yml ##
     @@ .gitlab-ci.yml: check-whitespace:
    +   image: ubuntu:latest
        before_script:
          - ./ci/install-dependencies.sh
    ++  # Since $CI_MERGE_REQUEST_TARGET_BRANCH_SHA is only defined for merged
    ++  # pipelines, we fallback to $CI_MERGE_REQUEST_DIFF_BASE_SHA, which should
    ++  # be defined in all pipelines.
        script:
     -    - ./ci/check-whitespace.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
     +    - |
    -+      if [ -z ${CI_MERGE_REQUEST_TARGET_BRANCH_SHA} ]; then
    ++      if test -n "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++      then
    ++        ./ci/check-whitespace.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++      elif test -n "$CI_MERGE_REQUEST_DIFF_BASE_SHA"
    ++      then
     +        ./ci/check-whitespace.sh "$CI_MERGE_REQUEST_DIFF_BASE_SHA"
     +      else
    -+        ./ci/check-whitespace.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
    ++        echo "CI_MERGE_REQUEST_DIFF_BASE_SHA should always exist!"; exit 1
     +      fi
        rules:
          - if: $CI_PIPELINE_SOURCE == 'merge_request_event'
-:  ---------- > 8:  2b39431f93 ci/style-check: add `RemoveBracesLLVM` to '.clang-format'