Is the following code correct?

int a = 3;
extern const int& b;
const int c = b;    // (a)
const int& b = a;   // (b)
int main() {}

This program works on the most systems. But one compiler
generate code for a dynamic initialization of the reference
in line (b). This results in an exception in line (a), because
'b' isn't initialized at that point --- 'b' is a 'null-reference'.

My question: What is ill-formed? My program or the compiler?
I found a few notes in the C++-standard paper:
 8.5.7: 'a reference is bound directly'
        Without any initialzation?
 8.3.2: 'a null reference cannot exist in a well-defined program'
        But the generated code contains a null reference.

Please help!
 Widi
--
 Friedbert Widmann               phone: +49-261-38410
 Friedrich-Ebert-Ring 44         eMail: widi@uni-koblenz.de
 56068 Koblenz                     WWW: http://www.uni-koblenz.de/~widi
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