llvm-project/clang/test/CodeGen/2007-09-17-WeakRef.c

// RUN: %clang_cc1 -O1 -emit-llvm %s -o - | grep icmp
// PR1678

extern void B (void);
static __typeof(B) A __attribute__ ((__weakref__("B")));
int active (void)
{
  static void *const p = __extension__ (void *) &A;
  return p != 0;
}