Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Git pre-commit hook that invokes clang-format to reformat C/C++/Objective-C source code.
#!/bin/bash
# git pre-commit hook that runs an clang-format stylecheck.
# Features:
# - abort commit when commit does not comply with the style guidelines
# - create a patch of the proposed style changes
# modifications for clang-format by rene.milk@wwu.de
# This file is part of a set of unofficial pre-commit hooks available
# at github.
# Link: https://github.com/githubbrowser/Pre-commit-hooks
# Contact: David Martin, david.martin.mailbox@googlemail.com
##################################################################
# SETTINGS
# set path to clang-format binary
CLANG_FORMAT="/Users/wyi/usr/bin/clang-format"
# remove any older patches from previous commits. Set to true or false.
# DELETE_OLD_PATCHES=false
DELETE_OLD_PATCHES=false
# only parse files with the extensions in FILE_EXTS. Set to true or false.
# if false every changed file in the commit will be parsed with clang-format.
# if true only files matching one of the extensions are parsed with clang-format.
# PARSE_EXTS=true
PARSE_EXTS=true
# file types to parse. Only effective when PARSE_EXTS is true.
# FILE_EXTS=".c .h .cpp .hpp"
FILE_EXTS=".c .h .cpp .hpp .cc .hh .cxx .m"
##################################################################
# There should be no need to change anything below this line.
# Reference: http://stackoverflow.com/questions/1055671/how-can-i-get-the-behavior-of-gnus-readlink-f-on-a-mac
canonicalize_filename () {
local target_file=$1
local physical_directory=""
local result=""
# Need to restore the working directory after work.
pushd `pwd` > /dev/null
cd "$(dirname "$target_file")"
target_file=`basename $target_file`
# Iterate down a (possible) chain of symlinks
while [ -L "$target_file" ]
do
target_file=$(readlink "$target_file")
cd "$(dirname "$target_file")"
target_file=$(basename "$target_file")
done
# Compute the canonicalized name by finding the physical path
# for the directory we're in and appending the target file.
physical_directory=`pwd -P`
result="$physical_directory"/"$target_file"
# restore the working directory after work.
popd > /dev/null
echo "$result"
}
# exit on error
set -e
# check whether the given file matches any of the set extensions
matches_extension() {
local filename=$(basename "$1")
local extension=".${filename##*.}"
local ext
for ext in $FILE_EXTS; do [[ "$ext" == "$extension" ]] && return 0; done
return 1
}
# necessary check for initial commit
if git rev-parse --verify HEAD >/dev/null 2>&1 ; then
against=HEAD
else
# Initial commit: diff against an empty tree object
against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi
if [ ! -x "$CLANG_FORMAT" ] ; then
printf "Error: clang-format executable not found.\n"
printf "Set the correct path in $(canonicalize_filename "$0").\n"
exit 1
fi
# create a random filename to store our generated patch
prefix="pre-commit-clang-format"
suffix="$(date +%s)"
patch="/tmp/$prefix-$suffix.patch"
# clean up any older clang-format patches
$DELETE_OLD_PATCHES && rm -f /tmp/$prefix*.patch
# create one patch containing all changes to the files
git diff-index --cached --diff-filter=ACMR --name-only $against -- | while read file;
do
# ignore file if we do check for file extensions and the file
# does not match any of the extensions specified in $FILE_EXTS
if $PARSE_EXTS && ! matches_extension "$file"; then
continue;
fi
# clang-format our sourcefile, create a patch with diff and append it to our $patch
# The sed call is necessary to transform the patch from
# --- $file timestamp
# +++ - timestamp
# to both lines working on the same file and having a a/ and b/ prefix.
# Else it can not be applied with 'git apply'.
"$CLANG_FORMAT" -style=file "$file" | \
diff -u "$file" - | \
sed -e "1s|--- |--- a/|" -e "2s|+++ -|+++ b/$file|" >> "$patch"
done
# if no patch has been generated all is ok, clean up the file stub and exit
if [ ! -s "$patch" ] ; then
printf "Files in this commit comply with the clang-format rules.\n"
rm -f "$patch"
exit 0
fi
# a patch has been created, notify the user and exit
printf "\nThe following differences were found between the code to commit "
printf "and the clang-format rules:\n\n"
cat "$patch"
printf "\nYou can apply these changes with:\n git apply $patch\n"
printf "(may need to be called from the root directory of your repository)\n"
printf "Aborting commit. Apply changes and commit again or skip checking with"
printf " --no-verify (not recommended).\n"
exit 1
@ymadzhunkov

This comment has been minimized.

Copy link

ymadzhunkov commented Jun 30, 2017

Can you update lines 8 - 12 with correct links and emails. Thank you.

@Pierre-Sassoulas

This comment has been minimized.

Copy link

Pierre-Sassoulas commented Jan 30, 2018

Great code, many thanks.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.