Re: [PATCH v2] contrib/vhost-user-gpu: Fix compiler warning when compiling with -Wshadow

[Michael S. Tsirkin]

On Thu, Oct 12, 2023 at 02:18:44PM +0200, Markus Armbruster wrote:
> Thomas Huth <thuth@redhat.com> writes:
> 
> > Rename some variables to avoid compiler warnings when compiling
> > with -Wshadow=local.
> >
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >  v2: Renamed the variable to something more unique
> >
> >  contrib/vhost-user-gpu/vugpu.h          | 8 ++++----
> >  contrib/vhost-user-gpu/vhost-user-gpu.c | 6 +++---
> >  2 files changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/contrib/vhost-user-gpu/vugpu.h b/contrib/vhost-user-gpu/vugpu.h
> > index 509b679f03..654c392fbb 100644
> > --- a/contrib/vhost-user-gpu/vugpu.h
> > +++ b/contrib/vhost-user-gpu/vugpu.h
> > @@ -164,12 +164,12 @@ struct virtio_gpu_ctrl_command {
> >  };
> >  
> >  #define VUGPU_FILL_CMD(out) do {                                \
> > -        size_t s;                                               \
> > -        s = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,  \
> > +        size_t vugpufillcmd_s_ =                                \
> > +            iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,  \
> >                         &out, sizeof(out));                      \
> > -        if (s != sizeof(out)) {                                 \
> > +        if (vugpufillcmd_s_ != sizeof(out)) {                   \
> >              g_critical("%s: command size incorrect %zu vs %zu", \
> > -                       __func__, s, sizeof(out));               \
> > +                       __func__, vugpufillcmd_s_, sizeof(out)); \
> >              return;                                             \
> >          }                                                       \
> >      } while (0)
> 
> v1 renamed to s_ instead, which I find much easier to read.  Michael
> asked you to change it so it's less likely to break if we pass it a
> macro that also uses s_.  Unlikely to happen, and would fail safe: build
> breaks.
> 
> > diff --git a/contrib/vhost-user-gpu/vhost-user-gpu.c 
> > b/contrib/vhost-user-gpu/vhost-user-gpu.c
> > index aa304475a0..bb41758e34 100644
> > --- a/contrib/vhost-user-gpu/vhost-user-gpu.c
> > +++ b/contrib/vhost-user-gpu/vhost-user-gpu.c
> > @@ -834,7 +834,7 @@ vg_resource_flush(VuGpu *g,
> >                  .width = width,
> >                  .height = height,
> >              };
> > -            pixman_image_t *i =
> > +            pixman_image_t *img =
> >                  
> > pixman_image_create_bits(pixman_image_get_format(res->image),
> >                                           msg->payload.update.width,
> >                                           msg->payload.update.height,
> > @@ -842,11 +842,11 @@ vg_resource_flush(VuGpu *g,
> >                                                        payload.update.data),
> >                                           width * bpp);
> >              pixman_image_composite(PIXMAN_OP_SRC,
> > -                                   res->image, NULL, i,
> > +                                   res->image, NULL, img,
> >                                     extents->x1, extents->y1,
> >                                     0, 0, 0, 0,
> >                                     width, height);
> > -            pixman_image_unref(i);
> > +            pixman_image_unref(img);
> >              vg_send_msg(g, msg, -1);
> >              g_free(msg);
> >          }
> 
> I'm going to queue v1.  Michael, if you want me to queue v2 instead, or
> neither of the two, let me know.

Yea I think v2 is better, queue that please.