[PATCH v11 1/3] Initial support for LuaJIT scripting

[Eugene Syromiatnikov]

On Fri, Aug 25, 2017 at 11:33:30PM +0300, Victor Krapivensky wrote:
> strace is built with a Lua implementation, not a FFI library. LuaJIT
> comes with its own FFI library, non-LuaJIT users have to install a
> standalone one. A compile-time difference is that LuaJIT defines
> LUA_FFILIBNAME, and, in absence of it, strace tries to load a library
> named "ffi".
> The only run-time difference important to us is how a comparison against
> a null pointer should be done: LuaJIT requires comparing a boxed pointer
> against nil; luaffi with ffi.C.NULL; and luaffifb with ffi.NULL.
> Oh, and Lua 5.1 (non-LuaJIT) is not supported as for now, due to that
> standalone implementations don't support arithmetics on pointers.
> Honestly, I am not sure if supporting non-LuaJIT is worth it.

Got it, I thought that FFI should be a part of any Lua implementation (like,
linked with it => build-time decision) in order to be usable.