Re: Luajit and errno

[Mike Pall <mikelu-1105@...>]

Florian Weimer wrote:
> Could you add ffi.seterrno(), too?  I think it's needed because there
> are some C functions that cannot signal all errors if the original
> errno value is non-zero (e.g. strtold()).

I don't think there's a problem for strtol(), but the man page for
errno mentions getpriority().

I've extended ffi.errno() to take an optional argument. See:
  http://luajit.org/ext_ffi_api.html#ffi_errno

Note that clearing errno before a C function call and then
checking for a non-zero errno should only be used for these
exceptional cases. For most C functions the return value gives a
clear indication whether errno was set or not. Checking the return
value first is faster, too.

--Mike