The main issue this solves is that when the assert() from libc is called in a debugger, you end up several stack levels deep and have to hunt down where the crash actually occurred.

It ends up looking like this.
image

This approach instead makes the compiler generate a trap instruction and crash immediately.

PS: You could also implement cool custom formatting for asserts, but I didn't put that in for the sake of keeping it simple.

#define assertf(expr, ...) \
 (!(expr))? \
 (printf("%s:%d: assertion `%s` failed: \"", __FILE__, __LINE__, #expr), \
 printf(__VA_ARGS__), \
 printf('\"\n'), \ 
 CRASH()) \ 
 : (void)0
assertf(a == b, "expected %d but got %d", a, b);