[cfe-dev] NonNull attribute, bug report. (Or misunderstanding)

[Paolo Bolzoni]

Simple declaration:
extern void* my_memcpy (void *dest, const void *src, unsigned long len)
      __attribute__((nonnull (1, 2)));



The relative AST vertex do have the clang::Attr pointer. But this simple loop
outputs nothing:

my_decl is a clang::FunctionDecl* relative to the function declaration.
non_null_attribute is a clang::NonNullAttr* relative to the non null attribute
of my_decl.

for (unsigned int e = my_decl-> getNumParams(), b = 1; b <= e; ++b) {
  if (non_null_attribute-> isNonNull(b)) {
     std::cout << "Yes, parameter " << b << "is non-null!" << std::endl;
  }
}

What am I doing wrong? Or there indeed is a clang bug somewhere?
pb