From: eplmst AT lu DOT erisoft DOT se (Martin Stromberg)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Generating SIGSEGV
Date: 27 Sep 1999 10:07:11 GMT
Organization: Ericsson Erisoft AB, Sweden
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

The solution is to _use_ the value of i, otherwise it's optimised out
of the loop.

Martin Str|mberg (ams AT ludd DOT luth DOT se) wrote:
: Hmm. It's strange, when I really want to make my program crash with
: SIGSEGV it seems impossible to achive that.

: Here's my test prorgam:
: #include <limits.h>
: #include <stdio.h>

: int
: a_very_long_function_name_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(void)
: {
:   unsigned long *i_p;
:   unsigned long i;

:   for(i_p = NULL; i_p < ULONG_MAX-1000000; i_p += 409600)
:   {
:     printf("i_p = 0x%lx.\n", i_p);
:     i = *i_p;

/* Here we use i! Nice SIGSEGV, here it comes. */
    printf("i = 0x%ld.\n", i);

:   }

: }

: int main(void)
: {

:   a_very_long_function_name_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx();

:   return(0);
: }


Right,

							MartinS