Question

When is goto not "considered harmful"?

Answer 1

Well, I don't know about "harmful" - but it's pretty widely accepted that goto is bad form regardless of what language you're using.

Answer 2

How about finite state machines?

Answer 3

I mean, they're pretty cool. haha. How exactly do they relate to "goto"?

Answer 4

represent state transitions as gotos

Answer 5

goto's are harmful when the location it is pointing to is null or undefined.
I mean that if the code goes this way
goto xy;
and xy is not present or it has some malicious code then there is either an exception or the whole program is corrupted.

Answer 6

Right, but that didn't answer my question... :(

Answer 7

goto is pretty well accepted as a style for unwinding initialization code

Answer 8

that's a case when they're not harmful

Answer 9

for example

bool func()
{
char *a, *b, *c, *d;

if ((a = malloc(1000)) == NULL)
goto fail;

if ((b = malloc(1000)) == NULL)
goto b_failed;

if ((c = malloc(1000)) == NULL)
goto c_failed;

if ((d = malloc(1000)) == NULL)
goto d_failed;

return TRUE; // success!

d_failed:
free(c);
c_failed:
free(b);
b_failed:
free(a);
fail:
return FALSE; // failure
}

This is a pretty common style that unwinds initialization if a multi-step initializaition procedure fails. It's common practice in the linux kernel.