Re: stack overflow?

[Rici Lake <lua@...>]

On 30-Aug-05, at 5:24 PM, Brent Arias wrote:

> If I'm recursing deeply (pushing a couple parameters on the stack each
> time), and I'm checking lua_gettop(..) each time through, I presume it 
> will
> be larger each time?  That is, lua_gettop reveals the total stack 
> size, not
> just the size of the current recursive frame?

lua_gettop() at entry to a function tells you (precisely) the number of 
arguments supplied. Stack indices are within the current stackframe; 
all other frames are invisible.

There is no API to tell you how big the total stack is. You shouldn't 
care, really.

Recursing through a lua_CFunction uses up C stack frames as well as Lua 
stack frames. The MAXCCALLS setting is deliberately kept low in order 
to minimize the danger of overflowing the C stack, as I understand it, 
since there is no reliable way to test for this condition (whereas Lua 
can and does test for an out-of-memory condition when attempting to 
expand the Lua stack.)

Read the reference manual's short but precise section on the Lua API 
for more details :)

R.