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Groups > comp.lang.c.moderated > #414

Why sizeof(main) = 1?

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Hi,

On a Linux system with gcc, I am just wondering why sizeof(main) can
be 1 or sizeof when applied on any function name can yield 1 ever? Or
is it only gcc's perspective to say sizeof of an implicit function
pointer to be 1 since it gives sizeof(void) to be 1 based on the
backward compatibility with the pre C99 notion that void* had its
predecessor char* and usually sizeof(char) being 1?

Also, I tried the invariably buggy code to see if at all sizeof(main)
= 1 can be realized.

/* Keep the warnings aside for a minute, please! */
#include <stdio.h>

int main(void)
{
        printf("sizeof(char) : %zd\n", sizeof(char));
        printf("sizeof(main) : %zd\n", sizeof(main));

        char p = main; // Truncates into only one byte of the bytes
required to hold
                              // main's address - known bug. But just
to see sizeof(main) = 1 if at all makes any sense.

        ((int (*)(void))p)(); // Known to be buggy and wrong.

        return 0;
}

Any explanation is cheerful. :)

Cheers.
-- 
comp.lang.c.moderated - moderation address: clcm@plethora.net -- you must
have an appropriate newsgroups line in your header for your mail to be seen,
or the newsgroup name in square brackets in the subject line.  Sorry.

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Thread

Why sizeof(main) = 1? Myth__Buster <raghavanil4m@gmail.com> - 2013-01-04 18:14 -0600
  Re: Why sizeof(main) = 1? Barry Schwarz <schwarzb@dqel.com> - 2013-02-26 10:51 -0600
    Re: Why sizeof(main) = 1? Keith Thompson <kst-u@mib.org> - 2013-03-11 18:25 -0500
  Re: Why sizeof(main) = 1? Jasen Betts <jasen@xnet.co.nz> - 2013-02-26 10:51 -0600
  Re: Why sizeof(main) = 1? gordonb.k8xjg@burditt.org (Gordon Burditt) - 2013-02-26 10:51 -0600
  Re: Why sizeof(main) = 1? <kzelechowski@e3tech.local> - 2013-09-02 04:07 -0500
    Re: Why sizeof(main) = 1? James Kuyper <jameskuyper@verizon.net> - 2013-09-06 23:25 -0500
      Re: Why sizeof(main) = 1? Keith Thompson <kst-u@mib.org> - 2013-09-11 17:26 -0500
        Re: Why sizeof(main) = 1? James Kuyper <jameskuyper@verizon.net> - 2013-09-12 11:29 -0500
    Re: Why sizeof(main) = 1? Keith Thompson <kst-u@mib.org> - 2013-09-06 23:25 -0500
      Re: Why sizeof(main) = 1? Robert Wessel <robertwessel2@yahoo.com> - 2013-09-11 17:27 -0500
        Re: Why sizeof(main) = 1? James Kuyper <jameskuyper@verizon.net> - 2013-09-12 11:29 -0500
        Re: Why sizeof(main) = 1? Keith Thompson <kst-u@mib.org> - 2013-09-12 11:30 -0500
    Re: Why sizeof(main) = 1? Ken Brody <kenbrody@spamcop.net> - 2013-09-06 23:25 -0500

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