Re: [PATCH v4 0/7] util: Introduce qemu_get_runtime_dir()

[Akihiko Odaki <akihiko.odaki@daynix.com>]

On 2024/07/16 22:29, Paolo Bonzini wrote:
> On Tue, Jul 16, 2024 at 2:46 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>
>> On 2024/07/16 19:43, Paolo Bonzini wrote:
>>> On Tue, Jul 16, 2024 at 11:56 AM Daniel P. Berrangé <berrange@redhat.com> wrote:
>>>>
>>>> On Tue, Jul 16, 2024 at 11:06:57AM +0300, Michael Tokarev wrote:
>>>>> 16.07.2024 10:27, Akihiko Odaki wrote:
>>>>>> qemu_get_runtime_dir() returns a dynamically allocated directory path
>>>>>> that is appropriate for storing runtime files. It corresponds to "run"
>>>>>> directory in Unix.
>>>>>
>>>>> Since runtime dir is always used with a filename within, how about
>>>>>
>>>>>     char *qemu_get_runtime_path(const char *filename)
>>>>>
>>>>> which return RUNTIME_DIR/filename instead of just RUNTIME_DIR ?
>>>>
>>>> Yeah, I agree, every single caller of the function goes on to call
>>>> g_build_filename with the result. The helper should just be building
>>>> the filename itself.
>>>
>>> That would mean using variable arguments and g_build_filename_valist().
>>
>> We can't prepend an element to va_list.
> 
> You could do it in two steps, with g_build_filename(runtime_dir,
> first) followed by g_build_filename_valist(result, ap); doing these
> steps only if if first != NULL of course.

It unfortunately involves an extra effort to free the result of the 
first call of g_build_filename().

Regards,
Akihiko Odaki