[shiroiuma]

Why would you want to diff code and ignore formatting? If it's just whitespace changes, any decent diff program should have an option to ignore that, but if it's more substantial, I would want to see that in a PR.

If, for some odd reason, I wanted to compare two codebases that had diverged, and one had gotten some serious formatting changes (maybe the new person preferred a different coding style), I'd run them both through an automatic formatter program with the same options. For C code, "indent" is commonly available, for instance.