llvm-gcc-4.0/gcc/testsuite/gcc.dg/visibility-5.c

/* Test visibility attribute on definition of a function that has
   already had a forward declaration. */
/* { dg-do compile } */
/* { dg-require-visibility "" } */
/* { dg-final { scan-hidden "foo" } } */

void foo();

void
 __attribute__((visibility ("hidden")))
foo()
{ }