RHEL-65784: CI: Enable code style chacking with clang-format

Add empty config for clang-format.

Jira: https://issues.redhat.com/browse/RHEL-65784

Signed-off-by: Konstantin Kostiuk <[email protected]>

.clang-format

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+DisableFormat: true

.github/workflows/clang-format.yml

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+name: clang-format check
+on: [push, pull_request]
+
+jobs:
+  clang-format:
+    name: Code style check - ${{ matrix.path['check'] }}
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        path:
+          - check: '.'
+            exclude: './VirtIO'
+          - check: 'VirtIO'
+            exclude: ''
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Run clang-format style check for C/C++ programs.
+      run: |
+        sudo apt-get update
+        sudo apt-get install --no-install-recommends -y clang-format-18
+        bash Tools/clang-format.sh ${CHECK_PATH} "" ${EXCLUDE_REGEX}
+      env:
+        CHECK_PATH: ${{ matrix.path['check'] }}
+        EXCLUDE_REGEX: ${{ matrix.path['exclude'] }}

Tools/clang-format.sh

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+#!/usr/bin/env bash
+
+set -e
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+# Default to the root of the repository
+CHECK_PATH="${1:-"${SCRIPT_DIR}/.."}"
+CLANG_FORMAT_STYLE="${2:-"${CHECK_PATH}/.clang-format"}"
+EXCLUDE_REGEX="$3"
+INCLUDE_REGEX="$4"
+
+CLANG_FORMAT_STYLE="$(realpath "${CLANG_FORMAT_STYLE}")"
+
+echo "Using clang-format version: $(clang-format --version)"
+echo "Running clang-format on $(realpath ${CHECK_PATH})"
+echo "Using clang-format style file: ${CLANG_FORMAT_STYLE}"
+
+if [[ -z $EXCLUDE_REGEX ]]; then
+	EXCLUDE_REGEX="^$"
+fi
+
+# Set the filetype regex if nothing was provided.
+# Find all C/C++ files:
+#   h, H, hpp, hh, h++, hxx
+#   c, C, cpp, cc, c++, cxx
+if [[ -z $INCLUDE_REGEX ]]; then
+	INCLUDE_REGEX='^.*\.((((c|C)(c|pp|xx|\+\+)?$)|((h|H)h?(pp|xx|\+\+)?$)))$'
+fi
+
+# initialize exit code
+exit_code=0
+
+cd "${CHECK_PATH}"
+src_files=$(find "." -name .git -prune -o -regextype posix-egrep -regex "$INCLUDE_REGEX" -print)
+
+# check formatting in each source file
+IFS=$'\n' # Loop below should separate on new lines, not spaces.
+for file in $src_files; do
+    # Only check formatting if the path doesn't match the regex
+    if ! [[ ${file} =~ $EXCLUDE_REGEX ]]; then
+
+        formated_code="$(clang-format --style=file:"${CLANG_FORMAT_STYLE}" --verbose --Werror "${file}")"
+        if [[ -z "$formated_code" ]]; then
+            continue
+        fi
+
+        local_format="$(diff <(cat "${file}") <(echo "${formated_code}") || true)"
+        if [[ -n "${local_format}" ]]; then
+            echo "The file ${file} is not formatted correctly"
+            echo "${local_format}"
+            exit_code=1
+        fi
+    fi
+done
+
+echo "clang-format check finished with exit code: ${exit_code}"
+exit $exit_code

VirtIO/.clang-format

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+IndentWidth: 4
+TabWidth: 4
+UseTab: Never
+DisableFormat: true