Re: [Qemu-devel] [PATCH] linux-user: fix convertion of flock/flock64 l_type field

[Eric Blake <eblake@redhat.com>]

On 05/08/2018 12:08 PM, Max Filippov wrote:
> On Tue, May 8, 2018 at 9:36 AM, Laurent Vivier <laurent@vivier.eu> wrote:

In the subject, s/convertion/conversion/

>> As l_type values (F_RDLCK, F_WRLCK, F_UNLCK, F_EXLCK, F_SHLCK)
>> are not bitmasks, we can't use target_to_host_bitmask() and
>> host_to_target_bitmask() to convert them.
>>
>> Introduce target_to_host_flock() and host_to_target_flock()
>> to convert values between host and target.
>>

>> +static unsigned int host_to_target_flock(unsigned int type)
>> +{
>> +    switch (type) {
>> +#define TRANSTBL_CONVERT(a) case a: return TARGET_##a;
>> +    TRANSTBL_CONVERT(F_RDLCK)
>> +    TRANSTBL_CONVERT(F_WRLCK)
>> +    TRANSTBL_CONVERT(F_UNLCK)
>> +    TRANSTBL_CONVERT(F_EXLCK)
>> +    TRANSTBL_CONVERT(F_SHLCK)
>> +#undef  TRANSTBL_CONVERT
>> +    }
>> +    return type;
>> +}
>>
> 
> There's a duplication. Wouldn't it be better if it was done like the following:
> 
> #define FLOCK_TRANSTBL \
>      switch (type) {
>      TRANSTBL_CONVERT(F_RDLCK) \

If you do this, I'd lean towards omitting the trailing ; from 
TRANSTBL_CONVERT() and sticking it in FLOCK_TRANSTBL instead (it looks 
weird to see a statement-like macro called without a ';').

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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