Issue 0085: Is the return from main equivalent to calling exit?

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: Clive Feather, WG14
Date: 1993-12-03
Submitted against: C90
Status: Fixed
Fixed in: C90 TC2
Converted from: dr.htm, dr_085.html

Item 22 - returning from main

Consider the following program:

#include <stdlib.h>
 #include <stdio.h>

 int *pi;

 void handler (void)
        {
        printf ("Value is %d\n", *pi);
        }

 int main (void)
        {
        int i;

        atexit (handler);
        i = 42;
        pi = &i;
        return 0;
        }

Return from main is defined to be equivalent to calling exit (subclause 5.1.2.2.3). If the return statement was replaced by the equivalent call, the program would be strictly conforming. Is it strictly conforming without this replacement?

Note that if the answer is “yes,” special processing will be required for return from main, which will depend on whether the call being returned from is the initial call or a recursive one.

Comment from WG14 on 1997-09-23:

Correction

In subclause 5.1.2.2.3, page 7, add at the end of the first sentence the footnote:

In accordance with subclause 6.1.2.4, objects with automatic storage duration declared in main will no longer have storage guaranteed to be reserved in the former case even where they would in the latter.