How can I get a stack overflow in C++ and Unix?

Question

I'm wondering how to get an stack overflow error with a simple example, such as:

int recursSum (int n)
{
   return (n==1)? 1:n+recursSum(n-1);
}

I ask that stupid question because I only have some Segmentation fault, even with an empty function calling itself…

Am I missing something or is there any protection or something that prevents me for doing this?

Related: http://stackoverflow.com/questions/1657484/can-you-give-an-example-of-stack-overflow-in-c — , Dec 05 '11 at 18:54
In this case, a _stack overflow_ would be the underlying reason why you get the OS-defined _Segmentation fault_ error. — ninjalj, Dec 05 '11 at 18:54

score 6 · Accepted Answer · answered Dec 05 '11 at 18:35

A segmentation fault means that the memory protection kicked in and prevented you from accessing memory you did not have available. This can occur for a variety of reasons, but one reason indicated is stack overflow (overflowing the stack into some other segment of memory).

score 3 · Answer 2 · answered Dec 05 '11 at 18:31

3

If the function is called with a negative or 0 integer argument, you'll face infinite recursion. However, the compiler likely can tail call optimize that particular function and you'd never see a stack overflow except in debug mode. The segmentation fault lies somewhere else.

answered Dec 05 '11 at 18:31

Puppy

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Yes, a smart compiler might optimize it into an infinite loop. However if it does not (because the OP didn't pass the appropriate -O flag for example), the given code will cause a stack overflow when called with a negative or zero argument, which will cause a segmentation fault (and so will the empty function calling itself that the OP also tried). So I don't see why you think the segmentation fault must lie somewhere else. – sepp2k Dec 06 '11 at 15:10

score 3 · Answer 3 · answered Dec 05 '11 at 18:35

3

A stack overflow is a type of segmentation fault, it looks like your system has just output a generic error.

You can read more here: http://en.wikipedia.org/wiki/Segmentation_fault

answered Dec 05 '11 at 18:35

Tom

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score 0 · Answer 4 · edited Dec 05 '11 at 20:39

0

Foo()

{

    float f[1024];

    Foo();

}

f is a dummy variable which will help filling stack quickly.

edited Dec 05 '11 at 20:39

FrustratedWithFormsDesigner

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answered Dec 05 '11 at 18:58

rakesh

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You may want to use it somehow, otherwise the optimizer may remove that array completely. – Matteo Italia Dec 05 '11 at 19:07
In this kind of function (and the original question), there's a reasonable chance the compiler will eliminate the recursion, depending on optimization levels, etc. – Bruce Stephens Dec 05 '11 at 22:42

How can I get a stack overflow in C++ and Unix?

4 Answers4