Question

How can I set a breakpoint in C or C++ code programatically that will work for gdb on Linux?

I.e.:

int main(int argc, char** argv)
{
    /* set breakpoint here! */
    int a = 3;
    a++;  /*  In gdb> print a;  expect result to be 3 */
    return 0;
}

Answer 1

One way is to signal an interrupt:

#include <csignal>

// Generate an interrupt
std::raise(SIGINT);

In C:

#include <signal.h>
raise(SIGINT);

UPDATE: Microsoft Docs says that Windows doesn’t really support SIGINT, so if portability is a concern, you’re probably better off using SIGABRT.

SIGINT is not supported for any Win32 application. When a CTRL+C interrupt occurs, Win32 operating systems generate a new thread to specifically handle that interrupt. This can cause a single-thread application, such as one in UNIX, to become multithreaded and cause unexpected behavior.