tree
convert_from_reference (tree val)
{
if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
{
tree t = canonical_type_variant (TREE_TYPE (TREE_TYPE (val)));
tree ref = build1 (INDIRECT_REF, t, val);
/* We *must* set TREE_READONLY when dereferencing a pointer to const,
so that we get the proper error message if the result is used
to assign to. Also, &* is supposed to be a no-op. */
TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
TREE_SIDE_EFFECTS (ref)
= (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val));
REFERENCE_REF_P (ref) = 1;
val = ref;
}
return val;
}
static void
do_build_assign_ref (tree fndecl)
{
tree parm = TREE_CHAIN (DECL_ARGUMENTS (fndecl));
tree compound_stmt;
compound_stmt = begin_compound_stmt (0);
parm = convert_from_reference (parm);
if (TYPE_HAS_TRIVIAL_ASSIGN_REF (current_class_type)
&& is_empty_class (current_class_type))
/* Don't copy the padding byte; it might not have been allocated
if *this is a base subobject. */;
else if (TYPE_HAS_TRIVIAL_ASSIGN_REF (current_class_type))
{
tree t = build2 (MODIFY_EXPR, void_type_node, current_class_ref, parm);
finish_expr_stmt (t);
}
else
{
tree fields;
int cvquals = cp_type_quals (TREE_TYPE (parm));
int i;
tree binfo, base_binfo;
/* Assign to each of the direct base classes. */
for (binfo = TYPE_BINFO (current_class_type), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
{
tree converted_parm;
/* We must convert PARM directly to the base class
explicitly since the base class may be ambiguous. */
converted_parm = build_base_path (PLUS_EXPR, parm, base_binfo, 1);
/* Call the base class assignment operator. */
finish_expr_stmt
(build_special_member_call (current_class_ref,
ansi_assopname (NOP_EXPR),
build_tree_list (NULL_TREE,
converted_parm),
base_binfo,
LOOKUP_NORMAL | LOOKUP_NONVIRTUAL));
}
/* Assign to each of the non-static data members. */
for (fields = TYPE_FIELDS (current_class_type);
fields;
fields = TREE_CHAIN (fields))
{
tree comp = current_class_ref;
tree init = parm;
tree field = fields;
tree expr_type;
int quals;
if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
continue;
expr_type = TREE_TYPE (field);
if (CP_TYPE_CONST_P (expr_type))
{
error ("non-static const member %q#D, can't use default "
"assignment operator", field);
continue;
}
else if (TREE_CODE (expr_type) == REFERENCE_TYPE)
{
error ("non-static reference member %q#D, can't use "
"default assignment operator", field);
continue;
}
if (DECL_NAME (field))
{
if (VFIELD_NAME_P (DECL_NAME (field)))
continue;
}
else if (ANON_AGGR_TYPE_P (expr_type)
&& TYPE_FIELDS (expr_type) != NULL_TREE)
/* Just use the field; anonymous types can't have
nontrivial copy ctors or assignment ops. */;
else
continue;
comp = build3 (COMPONENT_REF, expr_type, comp, field, NULL_TREE);
/* Compute the type of init->field */
quals = cvquals;
if (DECL_MUTABLE_P (field))
quals &= ~TYPE_QUAL_CONST;
expr_type = cp_build_qualified_type (expr_type, quals);
init = build3 (COMPONENT_REF, expr_type, init, field, NULL_TREE);
if (DECL_NAME (field))
init = build_modify_expr (comp, NOP_EXPR, init);
else
init = build2 (MODIFY_EXPR, TREE_TYPE (comp), comp, init);
finish_expr_stmt (init);
}
}
finish_return_stmt (current_class_ref);
finish_compound_stmt (compound_stmt);
}
