bindbc, SDL

[Mike Parker]

On Thursday, 27 March 2025 at 14:10:21 UTC, Richard (Rikki) 
Andrew Cattermole wrote:

> The bindbc family of packages, usually can link against a 
> shared library both during compilation (statically), or during 
> runtime (dynamically).
>
> The import library serves no purpose if you are linking 
> dynamically.

Let's get our terminology straight here.

BindBC supports static bindings and dynamic bindings.

Static bindings are used for both static and dynamic linking, 
i.e., there is a link-time dependency. Static linking means 
linking to the static library and there is no runtime dependency. 
Dynamic linking means linking with the import library on Windows 
and the dynamic library on other platforms, in which case there's 
a runtime dependency on the shared library.

Dynamic bindings are used for *dynamic loading*, not dynamic 
linking. This means there is no link-time dependency, but there 
is still a runtime dependency on the shared library. In this 
case, the shared library must be loaded manually at runtime.

In a static binding, the C function are declared as normal 
function declarations. When statically linking, the linker 
matches the symbols up. When dynamically linking, the system 
loader loads the shared library and then matches the symbols up.

In a dynamic binding, the C functions are declared as function 
pointers. The programmer must get a handle to the shared library 
via a system API call, then use the handle to fetch a pointer to 
each of the library's functions (or just the ones needed) and 
assign them to the function pointers declared by the binding. 
That's what bindbc-loader does, and why functions like `loadSDL` 
need to be called first when using the dynamic binding.