[webkit-dev] Proposal for coding guidelines: Do not use fall-through switch cases inside #ifdef's

[Tim Horton]

On Aug 17, 2012, at 11:57 AM, Bruno Abinader <brunoabinader at gmail.com> wrote:

> On Fri, Aug 17, 2012 at 2:24 PM, Joe Mason <jmason at rim.com> wrote:
>> What do you mean by "precompiler"?  The preprocessor?  Or is this a precompiled headers thing?
> 
> Indeed, s/precompiler/preprocessor :)
> 
>> 
>> Are you sure there wasn't a typo in the "case CSSPropertyWebkitTextDecorationLine:" line which caused a perfectly normal syntax error when CSS3_TEXT_DECORATION was defined?  Or maybe CSSPropertyWebkitTextDecorationLine was not defined?
> 
> There is no typo as far as I've checked. The following was added to
> Source/WebCore/css/CSSPropertyNames.in:
> 
> ...
> #if defined(ENABLE_CSS3_TEXT_DECORATION) && ENABLE_CSS3_TEXT_DECORATION
> -webkit-text-decoration-line
> #endif
> ...
> 
>> I dislike this.  Repeated code should be avoided. Fallthrough is a widely used and accepted technique to do that, ever since the days of C. I can't believe there's a compiler that doesn't handle this correctly.
> 
> +1 on that. I've re-checked the build bot output and it seems the
> issue is actually caused because CSSPropertyWebkitTextDecorationLine
> gets undefined. So I'm starting to believe the fail reason is
> something else skipping from my eyes.

Without looking at the code, I vaguely think that CSSPropertyWebkitTextDecorationLine comes from a generated file that might not rebuild when it's supposed to. You should try a clean build and see -- there've been a few problems with this recently (I ran into it when switching flexbox and regions/exclusions on and off a lot a few months ago, and a colleague ran into it again recently in a similar situation).

> The actual bug related to this
> issue is https://bugs.webkit.org/show_bug.cgi?id=94108 .
> 
>> 
>>> Where each switch case is handled individually (if you're curious
>>> about it, it is fixed in bug 90493). Said this, I would like to
>> 
>> https://bugs.webkit.org/show_bug.cgi?id=90493 is "[chromium] Don't archive build files generated by VS2010", and doesn't seem to be related.
> 
> My bad :/ The right bug is 94093:
> https://bugs.webkit.org/show_bug.cgi?id=94093 .
> 
> -- 
> Bruno de Oliveira Abinader
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