pre-commit

#!/bin/bash

# If this is an amend, not a new commit, need to take diff against HEAD~1, not HEAD, to do
# formatting.
RELATIVE_COMMIT="HEAD"
GIT_CMD="$(ps -ocommand= -p $PPID)"
if [[ ${GIT_CMD} == *"--amend"* ]]
then
    RELATIVE_COMMIT="HEAD~1"
fi

echo "Formatting against ${RELATIVE_COMMIT}"

# We need to ignore unstaged changes by stashing them, except for commit -a which will
# stage all changes after this script exits.
if [[ ${GIT_CMD} != *" -a"* ]]
then
    echo "Changes for commit are only in index"
    git stash -k
fi

${IMPALA_TOOLCHAIN}/llvm-${IMPALA_LLVM_VERSION}/bin/git-clang-format ${RELATIVE_COMMIT} \
                 --binary=${IMPALA_TOOLCHAIN}/llvm-${IMPALA_LLVM_VERSION}/bin/clang-format
git add -u

if [[ ${GIT_CMD} != *" -a"* ]]
then
    echo "Restoring unstaged changes"
    git stash pop
fi