Re: Object lifetimes inside Lua (3.1)

[Cyril Zorin <cyril.zorin@...>]

On 1-Jun-06, at 2:38 PM, Roberto Ierusalimschy wrote:

> > Are there any guarantees made with regard to the validity of pointers
> > inside Lua code? That is, suppose we look at luaV_execute -- is the
> > TProtoFunc* guaranteed to be valid after the luaV_execute call
> > finishes, or are internal pointers (which are derived from
> > lua_Object's) liable to be garbage collected like everything else?
>
> Lua code does not bother to clear pointers it is not going to use
> again, and/or to correct them before it needs. So there are several
> places along the code where pointers may be invalid. For instance, in
> luaV_execute there are several calls that potentially may  
> reallocate the
> stack and therefore invalidate 'ra'. But 'ra' is corrected only  
> when/if
> needed.

What about, in particular, a TProtoFunc* used in luaV_execute (recall  
I'm still in the world of Lua 3.1)? Will that pointer (and the  
underlying members like the function's bytecode, constants, etc.) be  
valid after luaV_execute completes?

> -- Roberto