[Bug c++/64877] strange warning message from -Waddress

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64877

--- Comment #5 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> ---
And just for the sake of completion, the warning we trigger is:

        else if (((code0 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type0))
                  && null_ptr_cst_p (op1))
                 /* Handle, eg, (void*)0 (c++/43906), and more.  */
                 || (code0 == POINTER_TYPE
                     && TYPE_PTR_P (type1) && integer_zerop (op1)))
          {
            if (TYPE_PTR_P (type1))
              result_type = composite_pointer_type (type0, type1, op0, op1,
                                                    CPO_COMPARISON, complain);
            else
              result_type = type0;

            if (TREE_CODE (op0) == ADDR_EXPR
B =>            && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
              {
                if ((complain & tf_warning)
                    && c_inhibit_evaluation_warnings == 0)
                  warning (OPT_Waddress, "the address of %qD will never be
NULL",
                           TREE_OPERAND (op0, 0));
              }
          }

It could be enough to test decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)) to
avoid building !op0.pfn when not needed.