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

[Paolo Bonzini <pbonzini@redhat.com>]

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.

But I agree that leaving the concatenation in the caller is not
particularly worse, and makes qemu_get_runtime_dir() more readable.

Paolo


Paolo