Dynamically loading libwayland complications

[Thiago Macieira]

On Tuesday, 28 June 2022 19:00:26 PDT Campbell Barton wrote:
> Hi, recently I was looking into dynamically loading libwayland to be
> able to support both X11 and Wayland, without requiring libwayland.
> For our project is currently a requirement for adopting Wayland.

Simplify your problem by dynamically loading a plugin that links to 
libwayland, instead of dynamically loading libwayland.

> From what I can tell there is no portable way to wrap
> `wl_proxy_marshal_flags` see [0],
> Using GCC's `__builtin_apply` does work but this isn't available in
> CLANG so I'd prefer to avoid it.

> The only portable way I found to handle this was to create a header
> that needs to be included before any of the headers generated by
> wayland-scanner (which make calls to `wl_proxy_marshal_flags`), which
> can be replaced by a reference to a function pointer instead of
> requiring the function to exist and link at build time.

How is this different from any other function from libwayland, variadic or not? 
If your code isn't linking to libwayland, then it can't call any of those 
functions. Therefore, you must be using a code generator that is calling 
something other than those functions.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel DPG Cloud Engineering