🚀 go-pugleaf

In article <448uaq$28g@rdsunx.crd.ge.com>, Christopher R. Volpe writes:

> Ok, I'll bite: What happens if the nested function references auto
> variables in the enclosing function, and then the nested function is
> called through a function pointer when the enclosing function is not
> active and said auto variable doesn't exist?

In general, one of two things happens: either the compiler generated
code that can check for this, and crash the program gracefully, or the
program yields undefined behaviour (i.e., crashes gracelessly).  This
is more or less independent of whether you use trampolines or "fat"
function pointers.

Checking for the possible appearance of this condition can partly be
done statically, if assignment of function pointers were governed by
rules similar to those of ALGOL 68.  Even so, runtime checks are
needed to cover all cases, and I suspect that these are easier to
implement when fat function pointers are used.

But note that C suffers from exactly this problem already, because a
function can export pointers to automatic variables, which can be kept
even after the function has exited.

-- 
Olaf Weber