But C doesn't let programs fail. (or at least not loudly) That's the problem, to me at least.

I've had this code yesterday on an embedded arm cortex m0:

bool tx_byte(char msg) { for (int i = 0; i < 8; i++) { tx_bit((msg >> i) & 1); } }

This function wouldn't return. What's even stranger, the variable i would increment past 7. The for-loop just continues.

I got a warning about the missing return statement in that function, but didn't think there could be a connection to my bug. It turned out that adding that return after the for loop fixed it.

The warning was one among about 100 others, as I was refactoring quite some code at the time. I only started working on the warnings after I had decided that me an two of my colleagues were just overlooking something and would fix the bug another day.

All that I wanted to say is that, no, C doesn't make you aware of what is happening. It has this giant pit of UB that does weird things when you fall into it. I was lucky that in my instance, I got a warning. I know other UB just works most of the time and goes unwarned.