[Mesa-dev] [PATCH 01/23] vulkan: Import vk_android_native_buffer.h

[Emil Velikov]

On 2 September 2017 at 09:17, Chad Versace <chadversary at chromium.org> wrote:
> Just as Mesa imports the Khronos Vulkan headers, it should import this
> Android-private Vulkan header too. This guarantees that Mesa will
> continue to build even when upstream Android breaks header
> compatibility.
>
That's the thing - upstream should not break. Although I share your
concern/focus to keep Mesa building/working.

I'm wondering when upstream changes the API/ABI in a non-backward
compatible manner.
There will be interesting corruption/crashes + we'll need to still "fix" Mesa.

There are a few other concerns though. See below.

> --- /dev/null
> +++ b/include/vulkan/vk_android_native_buffer.h

> +#ifndef __VK_ANDROID_NATIVE_BUFFER_H__
> +#define __VK_ANDROID_NATIVE_BUFFER_H__
> +
> +#include <system/window.h>

As mentioned in 23/23 as-is this will pull the above header as
dependency for normal Linux builds.
Regardless of my input in said patch, one could use a local
redeclaration for "buffer_handle_t", which is seemingly the only
reason why this include exists?

> +#include <vulkan/vulkan.h>
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#define VK_ANDROID_native_buffer 1
> +
> +#define VK_ANDROID_NATIVE_BUFFER_EXTENSION_NUMBER 11
> +#define VK_ANDROID_NATIVE_BUFFER_SPEC_VERSION     5
> +#define VK_ANDROID_NATIVE_BUFFER_EXTENSION_NAME   "VK_ANDROID_native_buffer"
> +
Version does not match the one in vk.xml, fortunately the rest do.

None of the remainder of this file has equivalent in vk.xml. That
combined with the deprecated notations indicates that the API/ABI is
not stable yet. Thus my earlier concern.

HTH
Emil