[libcxx-commits] [PATCH] D99691: [libcxx] adjusts formatting rules

[Mark de Wever via Phabricator via libcxx-commits]

Mordante added a comment.

In D99691#2663091 <https://reviews.llvm.org/D99691#2663091>, @curdeius wrote:

> Or, adding fuel to the fire, could we possibly deprecate C++03 mode in libc++?

Also a -1 for me. We have quite an amount of unit tests using C++03. I really dislike clang-format to automatically breaking these tests when formatting.



================
Comment at: libcxx/.clang-format:5
 Language: Cpp
-Standard: Cpp03
+Standard: Cpp11
 
----------------
curdeius wrote:
> Mordante wrote:
> > Quuxplusone wrote:
> > > Actually, I'd turn this all the way up to Cpp20 or however high it goes. The only interesting thing controlled by this option AFAIK is whether clang-format will do
> > > ```
> > > foo<bar<baz> > x;  // we must do this anywhere C++03-portability is required
> > > ```
> > > or
> > > ```
> > > foo<bar<baz>> x;  // we prefer this wherever possible
> > > ```
> > > Either way, blindly applying clang-format to //actual// libc++ code is going to screw it up one way or the other. But given that you're the only person relying on clang-format to format your patches AFAIK, and you're working exclusively on C++20 code (never on C++03 code), I think it's totally reasonable to check in a style file that specifies `Cpp20`.
> >  I also rely on clang-format for my patches and I'm not fond that this change allows to break C++98 code. So I prefer `std::vector<std::pair<int, int> >` over `std::vector<std::pair<int, int>>` and my C++03 unit tests break. Ideally I would like to have this option in clang format
> > ```
> > // clang-format Cpp03
> > std::vector<std::pair<int, int> > v3;
> > // clang-format Cpp11
> > std::vector<std::pair<int, int>> v11;
> > ```
> > Then we can use a sane default and override it where applicable. I'll reach out to the clang-format developers to see how feasible this would be.
> Same for me. Changing to `Standard: Cpp11` will possibly break code with no huge benefit IMO.
> 
> Now, taking my clang-format dev's hat...
> Concerning @Mordante's suggestion, that may be doable (preferably in a more general form e.g. `// clang-format Option: Value` or even `// clang-format {Style...}`), but not sure if worth doing, as it will possibly make the formatting inconsistent between different parts of the code if used injudiciously.
> And, the whole purpose of using clang-format is consistency.
> Now, taking my clang-format dev's hat...
> Concerning @Mordante's suggestion, that may be doable (preferably in a more general form e.g. `// clang-format Option: Value` or even `// clang-format {Style...}`), but not sure if worth doing, as it will possibly make the formatting inconsistent between different parts of the code if used injudiciously.
> And, the whole purpose of using clang-format is consistency.
I also love consistency but if a file has C++20 and C++03 code I wouldn't mind to have them format differently based on the language features. I think our mixing of C++ version is uncommon, mainly standard libraries and boost so I wouldn't mind if the `// clang-format CppXX` may only be used once in a file and affects the entire file. (Since I'm no clang-format dev I leave the best naming to you.)

Do you have better suggestions how mixing the C++ version on a per file basis can be achieved easier in clang-format?




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