Re: No line number on nil function?

[Roberto Ierusalimschy <rieru@...>]

On Wed, 13 Feb 2002, J. Perkins wrote:

> In my project, I have patched into luaD_error(), where I intercept
> scripting errors, add on file and line number information using the
> code from luaB__ERRORMESSAGE, and then quit the app (code available
> on request).
>
> If a syntax error occurs in a script this works fine, but if a
> script tries to call a function that doesn't exist, ie. "attempt to
> call global 'XXX' (a nil value)", no file/line info is available.
> That is to say, 'lua_getstack(L, 1, &ar)' returns zero. In this
> case, is there anyway to get the file/line where the error occurred?

This case seems to work fine wiht regular Lua:

  > lua
  Lua 4.0  Copyright (C) 1994-2000 TeCGraf, PUC-Rio
  > f()
  error: attempt to call global `f' (a nil value)
  stack traceback:
     1:  main of string "f()" at line 1
                 ^^^^^^^^^^^^         ^

Maybe there is something wrong with your patch? Do you (Lua)call a
function to handle the error? (Otherwise, the error would be on
level 0 in lua_getstack, not level 1...)

-- Roberto