Walter Bright:
> One of the problems is they can easily lead to stack exhaustion. Stack
> sizes for a thread must all be preallocated.
Yes, that's of course a problem. It's meaningful to allocate arrays on the
stack only if they are small. You can exhaust the/a stack even with normal
fixed-sized arrays too:
int foo(int n) {
int[100] a;
...
y = foo(k);
...
}
The main difference is that here you can see better that each nested call to
foo() burns 400+ bytes of stack (but as in the variable-length case, it's
possible that you don't statically know how many nested calls to foo() will
happen at runtime, so the end result is the same: you don't know if you will
have a stack overflow at runtime).
In truth we can live without variable-length stack allocated arrays, mine may
be just feature envy, and I prefer variable-length stack allocated arrays over
the raw alloca().
Thank you very much for showing up in this thread, I appreciate a small answer
too a lot :-)
Bye,
bearophile
