alloca() ?

[Maddas]

Hi.
I'm trying to use alloca() in a program but every time I do, I get a compiler error. Isn't it in stdlib.h? How can I use it, and if not, why is it forbidden?

Thanks, Maddas

[shamim]

I think the compiler you use support this, but it is not supported by ANSI C.

[Krzysztof Duleba]

alloca is defined in <alloca.h>.

[Maddas]

Thanks, my manpage said it was in either alloca.h and stdlib.h

[Krzysztof Duleba]

Not really. Alloca is not ansi or posix and therefore it should not be defined in stdlib.h. However, stdlib.h usually includes alloca.h. I guess that OJ is using strict ansi option and in that case you have to include alloca.h manually (and still it can cause some problems):

BUGS
The alloca function is machine and compiler dependent. On many systems
its implementation is buggy. Its use is discouraged.

On many systems alloca cannot be used inside the list of arguments of a
function call, because the stack space reserved by alloca would appear
on the stack in the middle of the space for the function arguments.