build: Add clang-format checking of pull request changes to CI

Check modified lines in a pull request for correct clang-format.
Note that checking is not performed unless there is a pull request.

Heavily leveraged from https://github.com/KhronosGroup/SPIRV-Tools.

1 files changed, 41 insertions, 0 deletions

diff --git a/scripts/check_code_format.sh b/scripts/check_code_format.sh
new file mode 100755
index 00000000..0a9a50ae
--- /dev/null
+++ b/scripts/check_code_format.sh
@@ -0,0 +1,41 @@
+#!/bin/bash
+# Copyright (c) 2017 Google Inc.
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Script to determine if source code in Pull Request is properly formatted.
+# Exits with non 0 exit code if formatting is needed.
+#
+# This script assumes to be invoked at the project root directory.
+
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+NC='\033[0m' # No Color
+
+FILES_TO_CHECK=$(git diff --name-only master | grep -E ".*\.(cpp|cc|c\+\+|cxx|c|h|hpp)$")
+
+if [ -z "${FILES_TO_CHECK}" ]; then
+  echo -e "${GREEN}No source code to check for formatting.${NC}"
+  exit 0
+fi
+
+FORMAT_DIFF=$(git diff -U0 master -- ${FILES_TO_CHECK} | python ./scripts/clang-format-diff.py -p1 -style=file)
+
+if [ -z "${FORMAT_DIFF}" ]; then
+  echo -e "${GREEN}All source code in PR properly formatted.${NC}"
+  exit 0
+else
+  echo -e "${RED}Found formatting errors!${NC}"
+  echo "${FORMAT_DIFF}"
+  exit 1
+fi