Simplified test case for http://stackoverflow.com/q/28046944/827263

README.md

This is a simplified test case for this question on Stack Overflow.

example.cpp

#include <stdio.h>

char test1[4];
char test2[4];
char test3[8];

int main()
{
    snprintf(test3, sizeof(test3), "%s %s", test1, test2);
    return 0;
}

output.txt

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="14.04.1 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.1 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
$ uname -a
Linux bomb20 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
$ g++ --version
g++ (Ubuntu 4.8.2-19ubuntu1) 4.8.2
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ valgrind --version
valgrind-3.10.0.SVN
$ g++ -g example.cpp -o example && valgrind --tool=exp-sgcheck ./example
==16916== exp-sgcheck, a stack and global array overrun detector
==16916== NOTE: This is an Experimental-Class Valgrind Tool
==16916== Copyright (C) 2003-2013, and GNU GPL'd, by OpenWorks Ltd et al.
==16916== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for copyright info
==16916== Command: ./example
==16916==
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
--16916-- warning: evaluate_Dwarf3_Expr: unhandled DW_OP_ 0x93
==16916== Invalid read of size 1
==16916==    at 0x4E7BA03: vfprintf (vfprintf.c:1661)
==16916==    by 0x4EA3108: vsnprintf (vsnprintf.c:119)
==16916==    by 0x4E84531: snprintf (snprintf.c:33)
==16916==    by 0x400564: main (example.cpp:9)
==16916==  Address 0x601045 expected vs actual:
==16916==  Expected: global array "test1" of size 4 in object with soname "NONE"
==16916==  Actual:   global array "test2" of size 4 in object with soname "NONE"
==16916==  Actual:   is 0 after Expected
==16916==
==16916==
==16916== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 4 from 4)
$