[cfe-dev] clang-format leading whitespace

[Volodymyr Sapsai via cfe-dev]

As an extra data point I want to tell that even with an automated formatter the indented leading whitespace does help. If you re-indent a block of code and leading whitespace is preserved, then you get a single chunk in the blame of the file. If you eat the leading whitespace then you have a million little pieces in the blame and it’s less clear just what happened. Something like

1111bc501498 (John Doe      2015-05-12 09:23:57 +0000  178) if (something) {
1111bc501498 (John Doe      2015-05-12 09:23:57 +0000  179)   // do something
2222c3ae83d8 (Adam Smith    2014-12-10 19:00:42 +0000  180)
1111bc501498 (John Doe      2015-05-12 09:23:57 +0000  181)   // do some more stuff
1111bc501498 (John Doe      2015-05-12 09:23:57 +0000  182) }

If leading whitespace was preserved after reindentation you would get a single blame chunk. The same applies to diff. Empty lines can make chunks too granular.

As for requirement
> be used in a project of significant size

I want to point out that preserving leading whitespace on whitespace-only lines is Xcode default setting. And as the result many projects can end up using this style. For example, a quick check of the top 5 Objective-C repositories with the most stars on GitHub <https://github.com/search?l=objective-c&o=desc&q=stars:%3E1&s=stars&type=Repositories> shows that 3 out of 5 are using predominantly this style (rs/SDWebImage, BradLarson/GPUImage, SnapKit/Masonry). It isn’t representative in any way, I just want to show that such style isn’t that obscure.

Thanks,
Volodymyr

> On Nov 13, 2017, at 05:19, Daniel Jasper via cfe-dev <cfe-dev at lists.llvm.org> wrote:
> 
> Generally, see here:
> https://clang.llvm.org/docs/ClangFormatStyleOptions.html#adding-additional-style-options <https://clang.llvm.org/docs/ClangFormatStyleOptions.html#adding-additional-style-options>
> 
> I vaguely remember this question being brought up before and I think we decided against it.
> 
> On Mon, Nov 13, 2017 at 2:14 PM, Manuel Klimek via cfe-dev <cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>> wrote:
> On Sat, Nov 11, 2017 at 7:20 AM Samuel Williams via cfe-dev <cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>> wrote:
> I am interested in contributing to clang-format, to add an option to preserve and correct leading indentation.
> 
> Right now if you write code such as:
> 
> {
> ....int x = 10;
> ....
> ....return x;
> }
> 
> The line in the middle will be truncated and there is no option to control it.
> 
> Some code prefers to have indented leading whitespace, indented to the same level as the previous line.
> 
> Would such a contribution be accepted and is anyone willing to help me through the process where necessary?
> 
> The current reasoning is that with an automated formatter the indented leading whitespace doesn't help any more.
>  
> 
> Thanks
> Samuel
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev>
> 
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org <mailto:cfe-dev at lists.llvm.org>
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev>
> 
> 
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20171208/94572d13/attachment.html>