[cmake-developers] Code style auto-formatting

[Brad King]

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
  ...

Plus the custom one for Cpp11 in Tests/CompileFeatures.

The next few weeks will be a good time to do a one-shot
style change commit because the feature freeze for the
CMake 3.6 release is June 1.  It is important to do sweeping
changes like this shortly before a release branch is created
because that way any fixes that must be backported to the
branch do not conflict with the style change.  Furthermore
most fixes needed to the previous release have already been
done.  If we don't do it now we will have to wait about
4 months for the next stable period.

If the above looks good I'll start an ANNOUNCE thread for
this to draw more attention to it.  While it will be possible
to script style updates while rebasing topics across this
change, it will be simpler if developers start new topics
after the style change.

-Brad