Re: [PATCH vkd3d 2/3] vkd3d-shader: Don't allocate memory for a string buffer ahead of time.

[Henri Verbeet]

On Fri, 13 Aug 2021 at 16:15, Matteo Bruni <mbruni(a)codeweavers.com> wrote:
> @@ -147,11 +143,6 @@ struct vkd3d_string_buffer *vkd3d_string_buffer_get(struct vkd3d_string_buffer_c
>          if (!(buffer = vkd3d_malloc(sizeof(*buffer))))
>              return NULL;
>          vkd3d_string_buffer_init(buffer);
> -        if (!vkd3d_string_buffer_resize(buffer, 1))
> -        {
> -            vkd3d_free(buffer);
> -            return NULL;
> -        }

I think Zebediah successfully convinced me it's useful for
vkd3d_string_buffer_get() to return empty but initialised buffers,
like wined3d's string_buffer_get() does. Note that a consequence of
not doing this is that we can no longer safely do something like the
following:

    buffer = vkd3d_string_buffer_get(...);

    if (flags & FLAT)
        vkd3d_string_buffer_printf(buffer, "flat ");
    if (flags & NOPERSPECTIVE)
        vkd3d_string_buffer_printf(buffer, "noperspective ");
    if (flags & CENTROID)
        vkd3d_string_buffer_printf(buffer, "centroid ");
    printf("%svec4 v;\n", buffer->buffer);

    vkd3d_string_buffer_release(..., buffer);

because now buffer->buffer is potentially NULL.