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From: "Chun, Eric Y" <eric.y.chun@intel.com>
To: "gdb@sourceware.org" <gdb@sourceware.org>
Subject: Conditional Breakpoints with Pointers
Date: Mon, 04 May 2015 21:12:00 -0000	[thread overview]
Message-ID: <64E3233B30622847B1E5ED56D2C1DBF00CACDC9F@FMSMSX108.amr.corp.intel.com> (raw)

in gdb, how do i set a conditional breakpoint depending on value of pointer keeping in mind that i have to check if pointer is null before dereferencing pointer?

here is an example of code i'm trying to debug:
    #include <iostream>
    using namespace std;
  
    int main () {
      int *i[10];
      int *j = NULL;
      int k;
  
      i[4] = new int;
      *i[4] = 8;
  
      for (k=0; k < 10; k++) {
        j = i[k];
      }
  
      return 0;
    }

i set conditional breakpoint at line "j=i[k]" but i got a seg fault:
    (gdb) b 14 if j && *j == 8
    (gdb) r
    Starting program: /nfs/blahblah/a.out
    Failed to read a valid object file image from memory.
    Program received signal SIGSEGV, Segmentation fault.

does anybody know why there is a segfault?


             reply	other threads:[~2015-05-04 21:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-04 21:12 Chun, Eric Y [this message]
2015-05-04 21:48 ` Philippe Waroquiers

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