Question

Okay, little oddity I discovered with my C++ compiler.

I had a not-overly complex bit of code to refactor, and I accidentally managed to leave in a path that didn’t have a return statement. My bad. On the other hand, this compiled, and segfaulted when I ran it and that path was hit, obviously.

Here’s my question: Is this a compiler bug, or is there no guarantee that a C++ compiler will enforce the need for a return statement in a non-void return function?

Oh, and to be clear, in this case it was an unecessary if statement without an accompanying else. No gotos, no exits, no aborts.

Answer 1

Personally I think this should be an error:

int f() {
}

int main() {
    int n = f();
    return 0;
}

but most compilers treat it as a warning, and you may even have to use compiler switches to get that warning. For example, on g++ you need -Wall to get:

[neilb@GONERIL NeilB]$ g++ -Wall nr.cpp
nr.cpp: In function 'int f()':
nr.cpp:2: warning: no return statement in function returning non-void

Of course, with g++ you should always compile with at least -Wall anyway.