[Mesa-dev] [PATCH] i965: Use C99 struct initializers in brw_bufmgr.c.

[Chris Wilson]

Quoting Kenneth Graunke (2017-11-26 10:08:49)
> This is cleaner than using a non-standard memclear macro (which does a
> memset to 0) and then initializing fields after the fact.  We move the
> declarations to where we initialized the fields.  While we're at it, we
> move the declaration of 'ret' that goes with the ioctl, eliminating the
> declaration section altogether.
> ---
> @@ -990,15 +965,15 @@ brw_bo_subdata(struct brw_bo *bo, uint64_t offset,
>                 uint64_t size, const void *data)
>  {
>     struct brw_bufmgr *bufmgr = bo->bufmgr;
> -   struct drm_i915_gem_pwrite pwrite;
> -   int ret;
>  
> -   memclear(pwrite);
> -   pwrite.handle = bo->gem_handle;
> -   pwrite.offset = offset;
> -   pwrite.size = size;
> -   pwrite.data_ptr = (uint64_t) (uintptr_t) data;
> -   ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite);
> +   struct drm_i915_gem_pwrite pwrite = {
> +      .handle = bo->gem_handle,
> +      .offset = offset,
> +      .size = size,
> +      .data_ptr = (uint64_t) (uintptr_t) data,

The (uint64_t) here is implicit in the assignment, just (uintptr_t) is
required to keep gcc quiet.
> +   };
> +
> +   int ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite);
>     if (ret != 0) {
>        ret = -errno;
>        DBG("%s:%d: Error writing data to buffer %d: "
> @@ -1050,17 +1025,16 @@ int
>  brw_bo_wait(struct brw_bo *bo, int64_t timeout_ns)
>  {
>     struct brw_bufmgr *bufmgr = bo->bufmgr;
> -   struct drm_i915_gem_wait wait;
> -   int ret;
>  
>     /* If we know it's idle, don't bother with the kernel round trip */
>     if (bo->idle && !bo->external)
>        return 0;
>  
> -   memclear(wait);
> -   wait.bo_handle = bo->gem_handle;
> -   wait.timeout_ns = timeout_ns;
> -   ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_WAIT, &wait);
> +   struct drm_i915_gem_wait wait = {
> +      .bo_handle = bo->gem_handle,
> +      .timeout_ns = timeout_ns,
> +   };
> +   int ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_WAIT, &wait);
>     if (ret == -1)
>        return -errno;

if (ret != 0) should be tidier for gcc, but more about being consistent.

> @@ -1330,11 +1299,8 @@ init_cache_buckets(struct brw_bufmgr *bufmgr)
>  uint32_t
>  brw_create_hw_context(struct brw_bufmgr *bufmgr)
>  {
> -   struct drm_i915_gem_context_create create;
> -   int ret;
> -
> -   memclear(create);
> -   ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &create);
> +   struct drm_i915_gem_context_create create = { };

= { /* keep valgrind happy */ } ?

> +   int ret = drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &create);
>     if (ret != 0) {
>        DBG("DRM_IOCTL_I915_GEM_CONTEXT_CREATE failed: %s\n", strerror(errno));
>        return 0;

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris