Re: [Qemu-devel] [PATCH] CODING_STYLE: update line length and mixed declaration rules

[Thomas Huth <thuth@redhat.com>]

On Fri, 19 Jun 2015 09:29:04 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> 1) Line lengths above 80 characters do exist.  They are rare, but
> they happen from time to time.  An ignored rule is worse than an
> exception to the rule, so do the latter.
> 
> 2) Mixed declarations also do exist at the top of #ifdef blocks.
> Remark on this particular usage and suggest an alternative.
> 
> Cc: Andreas Faerber <afaerber@suse.de>
> Cc: Markus Armbruster <armbru@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  CODING_STYLE          | 21 ++++++++++++++++-----
>  scripts/checkpatch.pl |  9 ++++++---
>  2 files changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/CODING_STYLE b/CODING_STYLE
> index d46cfa5..d013cb8 100644
> --- a/CODING_STYLE
> +++ b/CODING_STYLE
> @@ -31,7 +31,11 @@ Do not leave whitespace dangling off the ends of lines.
>  
>  2. Line width
>  
> -Lines are 80 characters; not longer.
> +Lines should be 80 characters; try not to make them longer.
> +
> +Sometimes it is hard to do, especially when dealing with QEMU subsystems
> +that use long function or symbol names.  Even in that case, do not make
> +lines _much_ longer than 80 characters.

Good idea ... this very, very strict 80 characters limit often drove me
crazy already. If the code is more readable with a 81 or 82 characters
line, that's IMHO a much better way to write code than to break it
artificially just to satisfy that rule.

...
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 7f0aae9..f4e7050 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -1470,10 +1470,13 @@ sub process {
>  		if ($line =~ /^\+/ && $prevrawline !~ /\/\*\*/ &&
>  		    $rawline !~ /^.\s*\*\s*\@$Ident\s/ &&
>  		    !($line =~ /^\+\s*$logFunctions\s*\(\s*(?:(KERN_\S+\s*|[^"]*))?"[X\t]*"\s*(?:,|\)\s*;)\s*$/ ||
> -		    $line =~ /^\+\s*"[^"]*"\s*(?:\s*|,|\)\s*;)\s*$/) &&
> -		    $length > 80)
> +		    $line =~ /^\+\s*"[^"]*"\s*(?:\s*|,|\)\s*;)\s*$/))
>  		{
> -			WARN("line over 80 characters\n" . $herecurr);
> +			if ($length > 90) {
> +				ERROR("line over 90 characters\n" . $herecurr);
> +			} if ($length > 80) {

Did you mean to use "elsif" here instead (because you've put the if on
the same line as the "}")?

> +				WARN("line over 80 characters\n" . $herecurr);
> +			}
>  		}
>  

 Thomas