sdl: use versioned library, cleanup ffi/util helpers

[benoit-pierre]

This change is 

[NiLuJe]

(nit: typo in the commit msg if this is to be a rebase, ffi/input is gone, not ffi/util ;)).

[NiLuJe]

A few questions, but good to go on principle ;).

Reviewed 5 of 5 files at r1, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @benoit-pierre)

---

ffi/util.lua line 685 at r1 (raw file):

        libSDL2, err = util.ffiLoadCandidates(candidates)
        if not libSDL2 then
            print("SDL2 not loaded:", libSDL2)

Shouldn't this still be printing err? libSDL2 is always false in this branch.

---

ffi/util.lua line 688 at r1 (raw file):

        end
    end
    return libSDL2 or nil

Would returning a false libSDL2 (as opposed to nil) here be an issue for ffi/SDL2_0.lua?

Or, perhaps a better question would be: should ffi/SDL2_0.lua handle failure to load SDL2 in a specific way?

[NiLuJe]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @benoit-pierre)

[benoit-pierre]

ffi/util.lua line 685 at r1 (raw file):

        libSDL2, err = util.ffiLoadCandidates(candidates)
        if not libSDL2 then
            print("SDL2 not loaded:", libSDL2)

Shouldn't this still be printing err? libSDL2 is always false in this branch.

Yep.

ffi/util.lua line 688 at r1 (raw file):

        end
    end
    return libSDL2 or nil

Would returning a false libSDL2 (as opposed to nil) here be an issue for ffi/SDL2_0.lua?

Or, perhaps a better question would be: should ffi/SDL2_0.lua handle failure to load SDL2 in a specific way?

No (it will fail in frontend/device.lua before that), but it's cleaner / more logical, no?

[NiLuJe]

Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @benoit-pierre)