Re: [Qemu-devel] [PATCH 1/2] CODING_STYLE: specify the indent rule for multiline code

[Eric Blake <eblake@redhat.com>]

On 2/18/19 7:31 PM, Wei Yang wrote:
> We didn't specify the indent rule for multiline code here, which may
> misleading users. And in current code, the code use different rules.
> 
> Add this rule in CODING_STYLE to make sure this is clear to every one.
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Suggested-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  CODING_STYLE | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/CODING_STYLE b/CODING_STYLE
> index ec075dedc4..73f66ca185 100644
> --- a/CODING_STYLE
> +++ b/CODING_STYLE
> @@ -29,6 +29,32 @@ Spaces of course are superior to tabs because:
>  
>  Do not leave whitespace dangling off the ends of lines.
>  
> +1.1 Multiline Indent
> +
> +There are several places where indent is necessary:
> +
> + - struct definition
> + - if/else
> + - while/for
> + - function definition & call
> +
> +All the above cases apply the same rule: indent with four spaces.

Is this redundant with the earlier statement that "QEMU indents are four
spaces."?

> +
> +While the last three case may face another situation: code should spread into
> +several lines. In this case the rule is align the new line with first
> +parentheses.

Grammar is awkward - the leading 'while' makes it sound like that you
have a dependent clause, but then never provide the independent clause.
Maybe a completely different wording is better:

When breaking up a long line to fit within line widths, align the
secondary lines just after the opening parenthesis of the first.

> +
> +For example:
> +
> +    if (a == 1 &&
> +        b == 2)
> +

Maybe:

if (a == 1 &&
    b == 2) {

to match our later recommendations on always using {}.

> +    while (a == 1 &&
> +           b == 2)
> +

Similar.

> +    do_something(arg1, arg2
> +                 arg3)
> +

and here, I'd include the ';' to make it a valid statement.

>  2. Line width
>  
>  Lines should be 80 characters; try not to make them longer.
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org