[PATCH v2 7/8] ci: run style check on GitHub and GitLab

[Karthik Nayak <karthik.188@gmail.com>]

We don't run style checks on our CI, even though we have a
'.clang-format' setup in the repository. Let's add one, the job will
validate only against the new commits added and will only run on merge
requests. Since we're introducing it for the first time, let's allow
this job to fail, so we can validate if this is useful and eventually
enforce it.

For GitLab, we use the 'CI_MERGE_REQUEST_TARGET_BRANCH_SHA' variable by
default to obtain the base SHA of the merged pipeline (which is only
available for merged pipelines [1]). Otherwise we use the
'CI_MERGE_REQUEST_DIFF_BASE_SHA' variable.

[1]: https://docs.gitlab.com/ee/ci/variables/predefined_variables.html#predefined-variables-for-merge-request-pipelines

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 .github/workflows/check-style.yml | 29 +++++++++++++++++++++++++++++
 .gitlab-ci.yml                    | 17 +++++++++++++++++
 ci/install-dependencies.sh        |  2 +-
 ci/run-style-check.sh             |  8 ++++++++
 4 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 .github/workflows/check-style.yml
 create mode 100755 ci/run-style-check.sh

diff --git a/.github/workflows/check-style.yml b/.github/workflows/check-style.yml
new file mode 100644
index 0000000000..27276dfe5e
--- /dev/null
+++ b/.github/workflows/check-style.yml
@@ -0,0 +1,29 @@
+name: check-style
+
+# Get the repository with all commits to ensure that we can analyze
+# all of the commits contributed via the Pull Request.
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+# Avoid unnecessary builds. Unlike the main CI jobs, these are not
+# ci-configurable (but could be).
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check-style:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+
+    - name: git clang-format
+      continue-on-error: true
+      id: check_out
+      run: |
+        ./ci/run-style-check.sh \
+          "${{github.event.pull_request.base.sha}}"
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 37b991e080..dc43fc8ba8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -123,6 +123,23 @@ check-whitespace:
   rules:
     - if: $CI_PIPELINE_SOURCE == 'merge_request_event'
 
+check-style:
+  image: ubuntu:latest
+  allow_failure: true
+  variables:
+    CC: clang
+  before_script:
+    - ./ci/install-dependencies.sh
+  script:
+    - |
+      if [ -z ${CI_MERGE_REQUEST_TARGET_BRANCH_SHA} ]; then
+        ./ci/run-style-check.sh "$CI_MERGE_REQUEST_DIFF_BASE_SHA"
+      else
+        ./ci/run-style-check.sh "$CI_MERGE_REQUEST_TARGET_BRANCH_SHA"
+      fi
+  rules:
+    - if: $CI_PIPELINE_SOURCE == 'merge_request_event'
+
 documentation:
   image: ubuntu:latest
   variables:
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 6ec0f85972..46fe12a690 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -43,7 +43,7 @@ ubuntu-*)
 		make libssl-dev libcurl4-openssl-dev libexpat-dev wget sudo default-jre \
 		tcl tk gettext zlib1g-dev perl-modules liberror-perl libauthen-sasl-perl \
 		libemail-valid-perl libio-pty-perl libio-socket-ssl-perl libnet-smtp-ssl-perl libdbd-sqlite3-perl libcgi-pm-perl \
-		${CC_PACKAGE:-${CC:-gcc}} $PYTHON_PACKAGE
+		${CC_PACKAGE:-${CC:-gcc}} $PYTHON_PACKAGE clang-format
 
 	mkdir --parents "$CUSTOM_PATH"
 	wget --quiet --directory-prefix="$CUSTOM_PATH" \
diff --git a/ci/run-style-check.sh b/ci/run-style-check.sh
new file mode 100755
index 0000000000..76dd37d22b
--- /dev/null
+++ b/ci/run-style-check.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+#
+# Perform style check
+#
+
+baseCommit=$1
+
+git clang-format --style file --diff --extensions c,h "$baseCommit"
-- 
2.45.1