incompatible function declaration

["Michael" <gonwg@xxxxxxxxxxx>]

Hi, 

gcc behaves differently for following program:

void foo2();
int main() {
   extern void foo(void);
   foo();
   foo2();
   return 0;
}

void foo2() {
   foo();
}


compilation command:  gcc -c t1.c

result:
1. gcc 3.2.2 compiles successfully.

2. gcc 4.0.3 gives following message:

t1.c: In function 'foo2':
t1.c:10: error: incompatible implicit declaration of function 'foo'
t1.c:3: error: previous implicit declaration of 'foo' was here


question:
   which one is more correct ? Is the error message too severe ?


Regards,

Mike