[cmake-developers] Code style auto-formatting

[Daniel Pfeifer]

On Mon, May 9, 2016 at 11:14 AM, Brad King <brad.king at kitware.com> wrote:
> On 05/02/2016 10:08 AM, Brad King wrote:
>> Next I'll look at the style updates themselves.
>
> I've made some more preparatory commits:
>
>  Isolate formatted streaming blocks with clang-format off/on
>  https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=64b55203
>
>  Move comments off of class access specifier lines
>  https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=85425a3e
>
>  Help clang-format wrap after braces on long initializer lists
>  https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=afca3735
>
>  Remove `//------...` horizontal separator comments
>  https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=0ac18d40
>
> These changes improve the formatting output in some local
> experiments.
>
> With the earlier changes to the #include order we no longer need
> to use any custom `IncludeCategories`.
>
> Here is the `.clang-format` file I'd like to use:
>
>   ---
>   # This configuration requires clang-format 3.8 or higher.
>   BasedOnStyle: Mozilla
>   AlignOperands: false
>   AllowShortFunctionsOnASingleLine: Inline
>   AlwaysBreakAfterReturnType: None
>   AlwaysBreakAfterDefinitionReturnType: None
>   ColumnLimit: 79
>   IndentCaseLabels: false
>   Standard: Cpp03
>   ...
>

"AllowShortFunctionsOnASingleLine: Inline" is default in the Mozilla
preset. This line can be removed.

What is your rationale for "IndentCaseLabels: false"? I find that
indenting them increases readability when switch statements use
hanging braces. If the opening "{" is on a separate line, indenting
the labels does not improve readability that much.

What is the rationale for "ColumnLimit: 79"? To make a line fit on old
school terminals, 80 should be OK. To make a diff or an email response
fit on old school terminals, two extra spaces are reserved. That leads
to a column limit of 78. Where does 79 come from?