[PATCH v2] hw/virtio/virtio-gpu: Fix compiler warning when compiling with -Wshadow

Thomas Huth posted 1 patch 6 months, 4 weeks ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20231009084559.41427-1-thuth@redhat.com
Maintainers: Gerd Hoffmann <kraxel@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>
include/hw/virtio/virtio-gpu.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
[PATCH v2] hw/virtio/virtio-gpu: Fix compiler warning when compiling with -Wshadow
Posted by Thomas Huth 6 months, 4 weeks ago
Avoid using trivial variable names in macros, otherwise we get
the following compiler warning when compiling with -Wshadow=local:

In file included from ../../qemu/hw/display/virtio-gpu-virgl.c:19:
../../home/thuth/devel/qemu/hw/display/virtio-gpu-virgl.c:
 In function ‘virgl_cmd_submit_3d’:
../../qemu/include/hw/virtio/virtio-gpu.h:228:16: error: declaration of ‘s’
 shadows a previous local [-Werror=shadow=compatible-local]
  228 |         size_t s;
      |                ^
../../qemu/hw/display/virtio-gpu-virgl.c:215:5: note: in expansion of macro
 ‘VIRTIO_GPU_FILL_CMD’
  215 |     VIRTIO_GPU_FILL_CMD(cs);
      |     ^~~~~~~~~~~~~~~~~~~
../../qemu/hw/display/virtio-gpu-virgl.c:213:12: note: shadowed declaration
 is here
  213 |     size_t s;
      |            ^
cc1: all warnings being treated as errors

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 v2: Renamed the variable to something even less trivial

 include/hw/virtio/virtio-gpu.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
index 390c4642b8..4739fa4689 100644
--- a/include/hw/virtio/virtio-gpu.h
+++ b/include/hw/virtio/virtio-gpu.h
@@ -225,13 +225,13 @@ struct VhostUserGPU {
 };
 
 #define VIRTIO_GPU_FILL_CMD(out) do {                                   \
-        size_t s;                                                       \
-        s = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,          \
+        size_t virtiogpufillcmd_s_ =                                    \
+            iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,          \
                        &out, sizeof(out));                              \
-        if (s != sizeof(out)) {                                         \
+        if (virtiogpufillcmd_s_ != sizeof(out)) {                       \
             qemu_log_mask(LOG_GUEST_ERROR,                              \
                           "%s: command size incorrect %zu vs %zu\n",    \
-                          __func__, s, sizeof(out));                    \
+                          __func__, virtiogpufillcmd_s_, sizeof(out));  \
             return;                                                     \
         }                                                               \
     } while (0)
-- 
2.41.0


Re: [PATCH v2] hw/virtio/virtio-gpu: Fix compiler warning when compiling with -Wshadow
Posted by Markus Armbruster 6 months, 3 weeks ago
Thomas Huth <thuth@redhat.com> writes:

> Avoid using trivial variable names in macros, otherwise we get
> the following compiler warning when compiling with -Wshadow=local:
>
> In file included from ../../qemu/hw/display/virtio-gpu-virgl.c:19:
> ../../home/thuth/devel/qemu/hw/display/virtio-gpu-virgl.c:
>  In function ‘virgl_cmd_submit_3d’:
> ../../qemu/include/hw/virtio/virtio-gpu.h:228:16: error: declaration of ‘s’
>  shadows a previous local [-Werror=shadow=compatible-local]
>   228 |         size_t s;
>       |                ^
> ../../qemu/hw/display/virtio-gpu-virgl.c:215:5: note: in expansion of macro
>  ‘VIRTIO_GPU_FILL_CMD’
>   215 |     VIRTIO_GPU_FILL_CMD(cs);
>       |     ^~~~~~~~~~~~~~~~~~~
> ../../qemu/hw/display/virtio-gpu-virgl.c:213:12: note: shadowed declaration
>  is here
>   213 |     size_t s;
>       |            ^
> cc1: all warnings being treated as errors
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Queued.  Thanks!
Re: [PATCH v2] hw/virtio/virtio-gpu: Fix compiler warning when compiling with -Wshadow
Posted by Michael S. Tsirkin 6 months, 4 weeks ago
On Mon, Oct 09, 2023 at 10:45:59AM +0200, Thomas Huth wrote:
> Avoid using trivial variable names in macros, otherwise we get
> the following compiler warning when compiling with -Wshadow=local:
> 
> In file included from ../../qemu/hw/display/virtio-gpu-virgl.c:19:
> ../../home/thuth/devel/qemu/hw/display/virtio-gpu-virgl.c:
>  In function ‘virgl_cmd_submit_3d’:
> ../../qemu/include/hw/virtio/virtio-gpu.h:228:16: error: declaration of ‘s’
>  shadows a previous local [-Werror=shadow=compatible-local]
>   228 |         size_t s;
>       |                ^
> ../../qemu/hw/display/virtio-gpu-virgl.c:215:5: note: in expansion of macro
>  ‘VIRTIO_GPU_FILL_CMD’
>   215 |     VIRTIO_GPU_FILL_CMD(cs);
>       |     ^~~~~~~~~~~~~~~~~~~
> ../../qemu/hw/display/virtio-gpu-virgl.c:213:12: note: shadowed declaration
>  is here
>   213 |     size_t s;
>       |            ^
> cc1: all warnings being treated as errors
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  v2: Renamed the variable to something even less trivial
> 
>  include/hw/virtio/virtio-gpu.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Apropos why is this header not in include/hw/display/

> diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
> index 390c4642b8..4739fa4689 100644
> --- a/include/hw/virtio/virtio-gpu.h
> +++ b/include/hw/virtio/virtio-gpu.h
> @@ -225,13 +225,13 @@ struct VhostUserGPU {
>  };
>  
>  #define VIRTIO_GPU_FILL_CMD(out) do {                                   \
> -        size_t s;                                                       \
> -        s = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,          \
> +        size_t virtiogpufillcmd_s_ =                                    \
> +            iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num, 0,          \
>                         &out, sizeof(out));                              \
> -        if (s != sizeof(out)) {                                         \
> +        if (virtiogpufillcmd_s_ != sizeof(out)) {                       \
>              qemu_log_mask(LOG_GUEST_ERROR,                              \
>                            "%s: command size incorrect %zu vs %zu\n",    \
> -                          __func__, s, sizeof(out));                    \
> +                          __func__, virtiogpufillcmd_s_, sizeof(out));  \
>              return;                                                     \
>          }                                                               \
>      } while (0)
> -- 
> 2.41.0