Editing Stack overflow (section)

===Infinite recursion===
{{Main|Infinite recursion}}
The most-common cause of stack overflow is excessively deep or infinite recursion, in which a function calls itself so many times that the space needed to store the variables and information associated with each call is more than can fit on the stack.<ref name="segFault">[https://stackoverflow.com/questions/2685413/what-is-the-difference-between-a-segmentation-fault-and-a-stack-overflow/2685434#2685434 What is the difference between a segmentation fault and a stack overflow?] {{Webarchive|url=https://web.archive.org/web/20210913132615/https://stackoverflow.com/questions/2685413/what-is-the-difference-between-a-segmentation-fault-and-a-stack-overflow/2685434#2685434 |date=2021-09-13 }} at [[Stack Overflow]]</ref>

An example of infinite recursion in [[C (programming language)|C]].
<syntaxhighlight lang="c">
int foo() 
{
     return foo();
}
</syntaxhighlight>

The function ''foo'', when it is invoked, continues to invoke itself, allocating additional space on the stack each time, until the stack overflows resulting in a [[segmentation fault]].<ref name="segFault"/> However, some compilers implement [[tail-call optimization]], allowing infinite recursion of a specific sort—[[tail recursion]]—to occur without stack overflow. This works because tail-recursion calls do not take up additional stack space.<ref name="tailRecur">{{cite web
 |title       = An Introduction to Scheme and its Implementation
 |url         = http://www.federated.com/~jim/schintro-v14/schintro_73.html
 |date        = 1997-02-19
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20070810213035/http://www.federated.com/~jim/schintro-v14/schintro_73.html
 |archive-date = 2007-08-10
 }}</ref>

Some C compiler options will effectively enable [[tail-call optimization]]; for example, compiling the above simple program using [[GNU Compiler Collection|gcc]] with <code>-O1</code> will result in a segmentation fault, but not when using <code>-O2</code> or <code>-O3</code>, since these optimization levels imply the <code>-foptimize-sibling-calls</code> compiler option.<ref>{{cite web|title=Using the GNU Compiler Collection (GCC): Optimize Options|url=https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html|access-date=2017-08-20|archive-date=2017-08-20|archive-url=https://web.archive.org/web/20170820201527/https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html|url-status=live}}</ref> Other languages, such as [[Scheme (programming language)|Scheme]], require all implementations to include tail-recursion as part of the language standard.<ref>{{cite journal
 |author          = Richard Kelsey
 |date            = August 1998
 |title           = Revised<sup>5</sup> Report on the Algorithmic Language Scheme
 |url             = http://www.schemers.org/Documents/Standards/R5RS/
 |journal         = Higher-Order and Symbolic Computation
 |volume          = 11
 |issue           = 1
 |pages           = 7–105
 |doi             = 10.1023/A:1010051815785
 |accessdate      = 2012-08-09
 |author2         = William Clinger
 |author3         = Jonathan Rees
 |display-authors = 3
 |last4           = Rozas
 |first4          = G.J.
 |last5           = Adams Iv
 |first5          = N.I.
 |last6           = Friedman
 |first6          = D.P.
 |last7           = Kohlbecker
 |first7          = E.
 |last8           = Steele Jr.
 |first8          = G.L.
 |last9           = Bartley
 |first9          = D.H.
 |s2cid           = 14069423
 |archive-date    = 2007-01-05
 |archive-url     = https://web.archive.org/web/20070105152327/http://www.schemers.org/Documents/Standards/R5RS/
 |url-status      = live
|url-access= subscription
 }}</ref>