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@mastbaum
Created June 2, 2011 16:38
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A demonstration of GCC's ftrapv flag for C++ integer overflow debugging
#include<iostream>
#include<signal.h>
#include<limits.h>
/** g++'s -ftrapv flag provides some protection against integer overflows. It
* is a little awkward to use, though. All it will do is "trap" -- you must
* provide a signal handler to deal with it.
*
* (You must compile with -ftrapv for this to work)
*/
// a simple signal handler. it must take the signal as an argument, per
// signal.h, whether we use it or not.
void handler(int /*signal*/)
{
std::cout << "Overflow'd!" << std::endl;
}
int main()
{
// when we get a SIGABRT, call handler
signal(SIGABRT, &handler);
// LONG_MAX is the largest long integer on this system, from limits.h
long a = LONG_MAX;
int b = 1;
long c = a + b;
return 0;
}
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