How to clang-format on Build in Xcode

1. Install clang-format:

   $ brew install clang-format

2. Place .clang-format file under your project.

3. In Xcode, open Product > Scheme > Edit Scheme... > Build > Pre-actions.

4. Click + button and select your target (Provide build settings from).

5. Copy and paste this shell script:

   5-A. If you are using git (recomended):

   cd $SRCROOT && git status --porcelain \
   | awk '$1 ~ /^[MA]/ && $2 ~ /\.(cpp|hpp)$/ {print $2}' \
   | xargs /opt/homebrew/bin/clang-format -i -style=file

   Now your project files ends with .cpp or .hpp where git status is "added" or "modified" will be formatted on build.

   5-B. Otherwise:

   find -E ${PROJECT_DIR} -regex ".*\.(cpp|hpp)" | xargs /opt/homebrew/bin/clang-format -i -style=file

   Now your project files ends with .cpp or .hpp will be formatted on build.