Re: [alsa-devel] [PATCH] ALSA: usb-audio: Change structure initialisation to C99 style

[Takashi Iwai <tiwai@suse.de>]

On Wed, 15 Jun 2016 15:31:25 +0200,
Julia Lawall wrote:
> 
> 
> 
> On Wed, 15 Jun 2016, Takashi Iwai wrote:
> 
> > On Wed, 15 Jun 2016 15:26:34 +0200,
> > Amitoj Kaur Chawla wrote:
> > >
> > > Replace the in order struct initialisation style with explicit field
> > > style.
> > >
> > > The Coccinelle semantic patch used to make this change is as follows:
> > >
> > > @decl@
> > > identifier i1,fld;
> > > type T;
> > > field list[n] fs;
> > > @@
> > >
> > > struct i1 {
> > >  fs
> > >  T fld;
> > >  ...};
> > >
> > > @@
> > > identifier decl.i1,i2,decl.fld;
> > > expression e;
> > > position bad.p, bad.fix;
> > > @@
> > >
> > > struct i1 i2@p = { ...,
> > > + .fld = e
> > > - e@fix
> > >  ,...};
> > >
> > > Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
> > > ---
> > >  sound/usb/mixer_maps.c | 6 ++++--
> > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c
> > > index 1f8fb0d9..9038b2e 100644
> > > --- a/sound/usb/mixer_maps.c
> > > +++ b/sound/usb/mixer_maps.c
> > > @@ -107,8 +107,10 @@ static struct usbmix_name_map extigy_map[] = {
> > >   * e.g. no Master and fake PCM volume
> > >   *			Pavel Mihaylov <bin@bash.info>
> > >   */
> > > -static struct usbmix_dB_map mp3plus_dB_1 = {-4781, 0};	/* just guess */
> > > -static struct usbmix_dB_map mp3plus_dB_2 = {-1781, 618}; /* just guess */
> > > +static struct usbmix_dB_map mp3plus_dB_1 = {.min = -4781, .max = 0};
> > > +						/* just guess */
> > > +static struct usbmix_dB_map mp3plus_dB_2 = {.min = -1781, .max = 618};
> > > +						/* just guess */
> >
> > These are simple min/max table, so no big merit to write in such a
> > way.
> 
> My understanding is that structures are going to be randomized, so at
> least all global structures need C99 initialization.  Maybe Kees can
> provide further clarification.

If that's the motivation, *please* write it in the patch description.
Otherwise no one can know why such a change becomes mandatory.


thanks,

Takashi