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RE: missing return statement
> On Thu, Mar 12, 2009 at 4:56 PM, Robert Dewar wrote:
>> Nathan Ridge wrote:
>>
>>> Why does gcc not give an error about this?
>>> If I compile with "-Wall", it will give a WARNING saying
>>> "control reaches end of non-void function".
>>> However, shouldn't it be an ERROR to return nothing
>>> from a function that's supposed to return something?
>>> Does this not result in undefined behaviour? Why goes gcc allow it?
>>
>> Because the standard does not make this an error, you can't tell
>> if anyone needs a result, perhaps function is always called in
>> a void environment.
>>
>> A warning is all you can get, always pay attention to warnings!
>
> The standard does make it an error, in that if such a function
> (meaning a function that unconditionally falls off the end, when
> declared to return a value) is called _at all_ then undefined behavior
> results. More general cases can't be established at compile time, of
> course.
>
> To be conservative, a compiler would issue the error only at the call
> site, with possibly a warning (as gcc does) for the definition.
>
> -- James
I get no error when I compile the following code, even though a call to the function does take place:
class A {};
A function()
{
A result;
}
int main()
{
function();
return 0;
}
Regards,
Nate.
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