CI: check coding style of C code (!465)

.gitlab-ci.yml

@@ -42,6 +42,15 @@ py-sh-static:
   script:
     - .gitlab-ci/static_code_analysis.sh
 
+# coding style check
+clang-format-static:
+  stage: first
+  <<: *only-default
+  before_script:
+    - apk -q add clang git
+  script:
+    - .gitlab-ci/static_clang-format.sh
+
 # aports checks (generic)
 aports-static:
   stage: first

.gitlab-ci/static_clang-format.sh

+#!/bin/sh
+
+set -e
+
+clang-format -i $(find . -name "*.c")
+
+git diff > differences.patch
+
+if [ -s differences.patch ]; then
+    echo "C-Code formatting check failed!"
+    echo "Please make sure, the code is formatted properly!"
+    echo "Run:"
+    echo '    clang-format -i $(find . -name "*.c")'
+    echo
+    cat differences.patch
+    echo
+    rm differences.patch
+    exit 1
+else
+    echo "C-Code formatting check is sucessful!"
+    exit 0
+fi