Allow formatting of just the committed lines

[flybrotherlixiang]

Is it possible for the pre-commit hook to work just upon the committed code instead of the entire file?

[segiddins]

Currently, this is not possible, and I don't foresee it being possible because clang-format uses the entire file as context, each line isn't formatted on its own

[HIIgor]

--lines option of ClangFormat can do this, you need to get the diff lines using git diff in advance .

$DIR/bin/clang-format-3.8-custom -style=file -lines=$line

[HIIgor]

https://clang.llvm.org/docs/ClangFormat.html