How do I get a warning or error when returning values from functions returning void in GCC?

[bgutter <bgutter1@xxxxxxxxx>]

Hi,

The following code compiles with -Wall and -Werror with no error. This
is on GCC 3.4.6 running on Red Hat Enterprise Linux 4 on a 32-bit
Linux machine, nor will GCC 4.2.1 running on a 64-bit Linux machine
emit an error or warning:

    void f3(int value)
    {
        (void)value;
        return;
    }

    void f2(int value)
    {
        return f3(value);
    }

    void f1()
    {
        f2(23);
    }

But this code does not compile, but fails with the error shown below:

    void f4()
    {
        return 23;
    }

    Isrc/st.c: In function 'void f4()':
    Isrc/st.c:35: error: return-statement with a value, in function
returning 'void'

Why?  I believe that I have turned on -Wall which should have caught
this error.  Other compilers such as the old Visual Studio 6 compiler
on Windows do report an error.

Is there some special compile option I should be using here?

Thanks,
bgutter