A bug (?) with inline functions at O0: undefined reference

[Ilya Verbin]

Hi All,

I've discovered a strange behaviour on trunk gcc, here is the reproducer:

inline int foo ()
{
  return 0;
}

int main ()
{
  return foo ();
}

$ gcc main.c
/tmp/ccD1LeXo.o: In function `main':
main.c:(.text+0xa): undefined reference to `foo'
collect2: error: ld returned 1 exit status

Is this a bug?  If yes, is it known?
GCC 4.8.3 works fine though.

Thanks,
  -- Ilya