Re: [Qemu-devel] [PATCH] scripts/checkpatch.pl: Enforce multiline comment syntax

[Markus Armbruster]

Peter Maydell <address@hidden> writes:

> On 10 August 2018 at 07:22, Markus Armbruster <address@hidden> wrote:
>> Peter Maydell <address@hidden> writes:
>>
>>> We now require Linux-kernel-style multiline comments:
>>>     /*
>>>      * line one
>>>      * line two
>>>      */
>>>
>>> Enforce this in checkpatch.pl, by backporting the relevant
>>> parts of the Linux kernel's checkpatch.pl. (The only changes
>>> needed are that Linux's checkpatch.pl WARN() function takes
>>> an extra argument that ours does not.)
>>
>> Really?  [*]
>
> Yes; the parts that I have taken from checkpatch.pl
> are only modified by adjusting the WARN() function calls.
>
>>> The kernel's checkpatch does not enforce "leading /* on
>>> a line of its own, so that part is unique to QEMU's checkpatch.
>>>
>>> Sample warning output:
>>>
>>> WARNING: Block comments use a leading /* on a separate line
>>> #34: FILE: hw/intc/arm_gicv3_common.c:39:
>>> +    /* Older versions of QEMU had a bug in the handling of state 
>>> save/restore
>>>
>>> Signed-off-by: Peter Maydell <address@hidden>
>>> ---
>>> I'm still not used to the leeading-/*-on-it's-own style,
>>> so having checkpatch catch my lapses is handy...
>>
>> Yes, please!
>>
>>> I used WARN level severity mostly because Linux does.
>>> ---
>>>  scripts/checkpatch.pl | 48 +++++++++++++++++++++++++++++++++++++++++++
>>>  1 file changed, 48 insertions(+)
>>>
>>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>>> index 42e1c50dd80..18bc3c59c85 100755
>>> --- a/scripts/checkpatch.pl
>>> +++ b/scripts/checkpatch.pl
>>> @@ -1566,6 +1566,54 @@ sub process {
>>>  # check we are in a valid C source file if not then ignore this hunk
>>>               next if ($realfile !~ /\.(h|c|cpp)$/);
>>>
>>> +# Block comment styles
>>> +
>>> +             # Block comments use /* on a line of its own
>>> +             if ($rawline !~ address@hidden/\*.*\*/[ \t]*$@ &&      
>>> #inline /*...*/
>>> +                 $rawline =~ address@hidden/\*\*?[ \t]*.+[ \t]*$@) { # /* 
>>> or /** non-blank
>>> +                     WARN("Block comments use a leading /* on a separate 
>>> line\n" . $herecurr);
>>> +             }
>>> +
>
> This is the bit that is "unique to QEMU's checkpatch",
> per the commit message.
>
>
>> [*] The kernel's has
>>
>>    # Networking with an initial /*
>>                    if ($realfile =~ address@hidden(drivers/net/|net/)@ &&
>>                        $prevrawline =~ /^\+[ \t]*\/\*[ \t]*$/ &&
>>                        $rawline =~ /^\+[ \t]*\*/ &&
>>                        $realline > 2) {
>>                            WARN("NETWORKING_BLOCK_COMMENT_STYLE",
>>                                 "networking block comments don't use an 
>> empty /* line, use /* Comment...\n" . $hereprev);
>>                    }
>>
>> which makes no sense for us.
>
> This is a part which I did not take from kernel checkpatch;
> it is not a "relevant part", per the commit message.
>
>> With a corrected commit message:
>
> The commit message still makes sense to me.

It confused me.  Looks like I'm too easily confused today.

>> Reviewed-by: Markus Armbruster <address@hidden>

Feel free to use this R-by even without commit message improvements.