Is there a portable equivalent to DebugBreak()/__debugbreak?

Question

In MSVC, DebugBreak() or __debugbreak cause a debugger to break. On x86 it is equivalent to writing \"_asm int 3\", on x64 it is something different. When compiling with gcc

Answer 1

#define __debugbreak() \
do \
{       static bool b; \
        while (!b) \
                sleep(1); \
        b = false; \
} while (false)

When the process is sleeping, you can attach a debugger to the process, change the variable b to break the loop and do your thing. This code might not work in an optimized build!