Pretty printing should use \r\n on Windows.

[retep998]

On Windows the preferred line ending is \r\n, not \n like it is on posix platforms.
Unfortunately using --pretty with rustc outputs \n newlines.
For comparison clang-format outputs \r\n on Windows.

[thestinger]

I don't really think the source code format should vary across platforms. Using UTF-8 with consistent line endings everywhere works fine and it means the files are portable across operating systems.

[retep998]

Nonetheless, text editors on windows all use \r\n so having mixed \n and \r\n isn't any better, nevermind some editors don't even display \n correctly.
Also every time I open up git gui to commit some code, it yells at me about the line endings.
Since Git can already checkout files as \r\n on windows and push them back as \n to repos, having --pretty emit \r\n on windows wouldn't decrease portability.

[retep998]

This likely depends on #14400 being merged first.

[rprichard]

Did anyone ever consider having stdout convert LF to CRLF automatically on Windows?

[tamird]

#24696 generated enough resistance that I think we should not pursue this. I'm not sure how to get to a decision, but it'd be nice to lock this down.

[steveklabnik]

Triage: no changes in the last two years. @rust-lang/compiler and @rust-lang/lang , do you have any thoughts here? There was a PR for this, but it was closed in favor of gaining some kind of consensus.

[nikomatsakis]

I personally don't have any problem emitting \r\n, but I'm not a big fan of offering the pretty printer at all, mostly because it's a complex, little-used piece of code. It's definitely handy for debugging macros though and we don't really have a good alternative right now, so it seems like it'd be good if it integrated more smoothly with windows.

That said, I think the proper comparison for clang --format is really rustfmt, right? The pretty-printer is basically a (crude) macro-debugging tool at this point.

[retep998]

The pretty printer is incredibly useful for debugging macros, but that's really about it. I don't care anymore about the choice of line ending for pretty printing, and rustfmt takes care of formatting code. I just want the pretty printer to be polished as a proper macro debugging tool, the equivalent of preprocessing only in C++.