“missing return statement”, but I know it is there

Question

Assume I have the following function:

// Precondition:  foo is \'0\' or \'MAGIC_NUMBER_4711\'
// Returns:       -1 if foo is \'0\'
//                 1 if fo         


        

Answer 1

In C89 and in C99, the return statement is never required. Even if it is a function that has a return different than void.

C99 only says:

(C99, 6.9.1p12 "If the } that terminates a function is reached, and the value of the function call is used by the caller, the behavior is undefined."

In C++11, the Standard says:

(C++11, 6.6.3p2) "Flowing off the end of a function is equivalent to a return with no value; this results in undefined behavior in a value-returning function"