#!/bin/sh

# Usage: add this file to your project's .git/hooks directory. Rename it to
# just 'pre-commit'.
# Now, when you change some files in repository and try to commit these
# changes, git will run this script right before commit. Cppcheck will scan
# changed/new files in repository. If it finds some issues, script returns with
# exit code 1, rejecting commit. Otherwise, script returns 0, and you can
# actually commit your changes.
#
# Example:
# $ cat hello.c
# int main() {
#    int *s = malloc(10);
# }
# $ git add hello.c
# $ git commit
# Checking hello.c...
# [hello.c:3]: (error) Memory leak: s
# [hello.c:2]: (error) The allocated size 10 is not a multiple of the underlying type's size.
#
# $ vim hello.c
# $ cat hello.c
# int main() {
# }
# $ git add hello.c
# $ git commit
# Checking hello.c...
# $

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

# We should pass only added or modified C/C++ source files to cppcheck.
changed_files=$(git diff-index --cached $against | \
	grep -E '[MA]	.*\.(c|cpp|cc|cxx)$' | cut -f 2)

if [ -n "$changed_files" ]; then
	cppcheck --error-exitcode=1 $changed_files
	exit $?
fi

exit 0