fix clang build version on Ubuntu Artful

[bukzor]

Ported from Linuxbrew/brew#621

Before:

$ brew config | grep Clang:
Clang: 4.0 build 

After:

$ brew config | grep Clang:     
Clang: 4.0 build 401

[MikeMcQuaid]

This indentation change is incorrect; it's part of the if statement above. Also, what is present in the .* before RELEASE?

[bukzor]

The string is clang version 5.0.1 (tags/RELEASE_501/final).
According to the pastebins I was able to find, the "501" is what's found under osx.

[MikeMcQuaid]

Cool, thanks. What about making it tags/RELEASE_ instead of .*?

[bukzor]

I was less certain that would continue to match, and I don't think the current pattern will over-match.

[MikeMcQuaid]

@bukzor I'd rather we go for something more conservative for now and extended when needed. Thanks!

[bukzor]

Can dooo!

[bukzor]

The intent is to make it more noticeable when the above regex doesn't match. I think it does a good job of that.
The output in that case looks like so:

Clang: 5.0 build ???

[sjackman]

I'd suggest Clang: 5.0 build N/A.

[bukzor]

"Not applicable" is the correct answer when a tool is not installed, which is its usage in the rest of this file, but the build number is indeed applicable when clang is installed, as it is here.

[sjackman]

Fair enough. I don't feel strongly.

[bukzor]

<3

[bukzor]

I changed the "???" string to "(parse error)", which should be more clear.

[bukzor]

Offenses:
Library/Homebrew/development_tools.rb:77:48: C: Use %r around regular expression.
           build_version = `#{path} --version`[/clang(-| version [^ ]+ \(tags\/RELEASE_)(\d{2,})/, 2]
                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Library/Homebrew/system_config.rb:213:64: C: Ternary operators must not be nested. Prefer if or else constructs instead.
      f.puts "Clang: #{clang.null? ? "N/A" : "#{clang} build #{clang_build.null? ? "???" : clang_build}"}"
                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[MikeMcQuaid]

@bukzor You can reproduce those errors locally with brew style.

[bukzor]

I'm not 100% happy with the result, but brew style is happy now.

[MikeMcQuaid]

Thanks again @bukzor!

[bukzor]

Thank you too @MikeMcQuaid. It's a pleasure to work with you all. You and the rest of the homebrew team are a role model for open-source upstreams, and collaborative software in general.

[MikeMcQuaid]

@bukzor Thanks for the kind words and taking the time to say them. We end up dealing with a lot of bile so comments like this are touching ❤️