Re: debug.getlocal from within return hook

["书呆彭, Peng Yi" <nerditation@...>]

在 2015/5/19 16:50, Philipp Janda 写道:
> Hi!
>
> Am 19.05.2015 um 10:33 schröbte Philipp Janda:
> > Thanks very much! I can confirm that a single explicit return value
> > fixes the behavior of the test script on Lua 5.1, 5.2, and 5.3 (an empty
> > `return` is insufficient). Unfortunately, in my original code where I
> > encountered the problem I already had an explicit return value (and it
> > still doesn't work except on LuaJIT). I'll try to come up with an
> > updated test case.
>
> As promised here the updated test case. Interestingly, which local variables get garbled depends on which local variable I return (unfortunately the original code is primarily used on module chunks where I often return the first local I define (`local M = {}`)) ...

as Roberto said, it is due to an optimization in the opcode generator.
before Lua changes(or should I say fixes?) this inconsistent hook behavior,
you can use a simple workaround: just reserve a new stack slot and copy the
to-be-returned local variable there, then return the new one.

in your test script, it is something like:

-------------------------------------
  local function func ()
    local a, b, c, d, e = <...>
    <...>
    local __ret = b
    return __ret
  end
-------------------------------------

--
the nerdy Peng / 书呆彭 / Sent from Thunderbird