void
make_friend_class (tree type, tree friend_type, bool complain)
{
tree classes;
/* CLASS_TEMPLATE_DEPTH counts the number of template headers for
the enclosing class. FRIEND_DEPTH counts the number of template
headers used for this friend declaration. TEMPLATE_MEMBER_P,
defined inside the `if' block for TYPENAME_TYPE case, is true if
a template header in FRIEND_DEPTH is intended for DECLARATOR.
For example, the code
template <class T> struct A {
template <class U> struct B {
template <class V> template <class W>
friend class C<V>::D;
};
};
will eventually give the following results
1. CLASS_TEMPLATE_DEPTH equals 2 (for `T' and `U').
2. FRIEND_DEPTH equals 2 (for `V' and `W').
3. TEMPLATE_MEMBER_P is true (for `W').
The friend is a template friend iff FRIEND_DEPTH is nonzero. */
int class_template_depth = template_class_depth (type);
int friend_depth = processing_template_decl - class_template_depth;
if (! MAYBE_CLASS_TYPE_P (friend_type))
{
error ("invalid type %qT declared %<friend%>", friend_type);
return;
}
if (friend_depth)
/* If the TYPE is a template then it makes sense for it to be
friends with itself; this means that each instantiation is
friends with all other instantiations. */
{
if (CLASS_TYPE_P (friend_type)
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (friend_type)
&& uses_template_parms (friend_type))
{
/* [temp.friend]
Friend declarations shall not declare partial
specializations. */
error ("partial specialization %qT declared %<friend%>",
friend_type);
return;
}
}
else if (same_type_p (type, friend_type))
{
if (complain)
warning (0, "class %qT is implicitly friends with itself",
type);
return;
}
/* [temp.friend]
A friend of a class or class template can be a function or
class template, a specialization of a function template or
class template, or an ordinary (nontemplate) function or
class. */
if (!friend_depth)
;/* ok */
else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
{
if (TREE_CODE (TYPENAME_TYPE_FULLNAME (friend_type))
== TEMPLATE_ID_EXPR)
{
/* template <class U> friend class T::X<U>; */
/* [temp.friend]
Friend declarations shall not declare partial
specializations. */
error ("partial specialization %qT declared %<friend%>",
friend_type);
return;
}
else
{
/* We will figure this out later. */
bool template_member_p = false;
tree ctype = TYPE_CONTEXT (friend_type);
tree name = TYPE_IDENTIFIER (friend_type);
tree decl;
if (!uses_template_parms_level (ctype, class_template_depth
+ friend_depth))
template_member_p = true;
if (class_template_depth)
{
/* We rely on tsubst_friend_class to check the
validity of the declaration later. */
if (template_member_p)
friend_type
= make_unbound_class_template (ctype,
name,
current_template_parms,
tf_error);
else
friend_type
= make_typename_type (ctype, name, class_type, tf_error);
}
else
{
decl = lookup_member (ctype, name, 0, true);
if (!decl)
{
error ("%qT is not a member of %qT", name, ctype);
return;
}
if (template_member_p && !DECL_CLASS_TEMPLATE_P (decl))
{
error ("%qT is not a member class template of %qT",
name, ctype);
error ("%q+D declared here", decl);
return;
}
if (!template_member_p && (TREE_CODE (decl) != TYPE_DECL
|| !CLASS_TYPE_P (TREE_TYPE (decl))))
{
error ("%qT is not a nested class of %qT",
name, ctype);
error ("%q+D declared here", decl);
return;
}
friend_type = CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl));
}
}
}
else if (TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
{
/* template <class T> friend class T; */
error ("template parameter type %qT declared %<friend%>", friend_type);
return;
}
else if (!CLASSTYPE_TEMPLATE_INFO (friend_type))
{
/* template <class T> friend class A; where A is not a template */
error ("%q#T is not a template", friend_type);
return;
}
else
/* template <class T> friend class A; where A is a template */
friend_type = CLASSTYPE_TI_TEMPLATE (friend_type);
if (friend_type == error_mark_node)
return;
/* See if it is already a friend. */
for (classes = CLASSTYPE_FRIEND_CLASSES (type);
classes;
classes = TREE_CHAIN (classes))
{
tree probe = TREE_VALUE (classes);
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
{
if (friend_type == probe)
{
if (complain)
warning (0, "%qD is already a friend of %qT", probe, type);
break;
}
}
else if (TREE_CODE (probe) != TEMPLATE_DECL)
{
if (same_type_p (probe, friend_type))
{
if (complain)
warning (0, "%qT is already a friend of %qT", probe, type);
break;
}
}
}
if (!classes)
{
maybe_add_class_template_decl_list (type, friend_type, /*friend_p=*/1);
CLASSTYPE_FRIEND_CLASSES (type)
= tree_cons (NULL_TREE, friend_type, CLASSTYPE_FRIEND_CLASSES (type));
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
friend_type = TREE_TYPE (friend_type);
if (!uses_template_parms (type))
CLASSTYPE_BEFRIENDING_CLASSES (friend_type)
= tree_cons (NULL_TREE, type,
CLASSTYPE_BEFRIENDING_CLASSES (friend_type));
}
}
int
is_friend (tree type, tree supplicant)
{
int declp;
tree list;
tree context;
if (supplicant == NULL_TREE || type == NULL_TREE)
return 0;
declp = DECL_P (supplicant);
if (declp)
/* It's a function decl. */
{
tree list = DECL_FRIENDLIST (TYPE_MAIN_DECL (type));
tree name = DECL_NAME (supplicant);
for (; list ; list = TREE_CHAIN (list))
{
if (name == FRIEND_NAME (list))
{
tree friends = FRIEND_DECLS (list);
for (; friends ; friends = TREE_CHAIN (friends))
{
tree this_friend = TREE_VALUE (friends);
if (this_friend == NULL_TREE)
continue;
if (supplicant == this_friend)
return 1;
if (is_specialization_of_friend (supplicant, this_friend))
return 1;
}
break;
}
}
}
else
/* It's a type. */
{
if (same_type_p (supplicant, type))
return 1;
list = CLASSTYPE_FRIEND_CLASSES (TREE_TYPE (TYPE_MAIN_DECL (type)));
for (; list ; list = TREE_CHAIN (list))
{
tree t = TREE_VALUE (list);
if (TREE_CODE (t) == TEMPLATE_DECL ?
is_specialization_of_friend (TYPE_MAIN_DECL (supplicant), t) :
same_type_p (supplicant, t))
return 1;
}
}
if (declp)
{
if (DECL_FUNCTION_MEMBER_P (supplicant))
context = DECL_CONTEXT (supplicant);
else
context = NULL_TREE;
}
else
{
if (TYPE_CLASS_SCOPE_P (supplicant))
/* Nested classes get the same access as their enclosing types, as
per DR 45 (this is a change from the standard). */
context = TYPE_CONTEXT (supplicant);
else
/* Local classes have the same access as the enclosing function. */
context = decl_function_context (TYPE_MAIN_DECL (supplicant));
}
/* A namespace is not friend to anybody. */
if (context && TREE_CODE (context) == NAMESPACE_DECL)
context = NULL_TREE;
if (context)
return is_friend (type, context);
return 0;
}
void
make_friend_class (tree type, tree friend_type, bool complain)
{
tree classes;
/* CLASS_TEMPLATE_DEPTH counts the number of template headers for
the enclosing class. FRIEND_DEPTH counts the number of template
headers used for this friend declaration. TEMPLATE_MEMBER_P,
defined inside the `if' block for TYPENAME_TYPE case, is true if
a template header in FRIEND_DEPTH is intended for DECLARATOR.
For example, the code
template <class T> struct A {
template <class U> struct B {
template <class V> template <class W>
friend class C<V>::D;
};
};
will eventually give the following results
1. CLASS_TEMPLATE_DEPTH equals 2 (for `T' and `U').
2. FRIEND_DEPTH equals 2 (for `V' and `W').
3. TEMPLATE_MEMBER_P is true (for `W').
The friend is a template friend iff FRIEND_DEPTH is nonzero. */
int class_template_depth = template_class_depth (type);
int friend_depth = processing_template_decl - class_template_depth;
if (! MAYBE_CLASS_TYPE_P (friend_type)
&& TREE_CODE (friend_type) != TEMPLATE_TEMPLATE_PARM)
{
/* N1791: If the type specifier in a friend declaration designates a
(possibly cv-qualified) class type, that class is declared as a
friend; otherwise, the friend declaration is ignored.
So don't complain in C++11 mode. */
if (cxx_dialect < cxx11)
pedwarn (input_location, complain ? 0 : OPT_Wpedantic,
"invalid type %qT declared %<friend%>", friend_type);
return;
}
friend_type = cv_unqualified (friend_type);
if (check_for_bare_parameter_packs (friend_type))
return;
if (friend_depth)
{
/* [temp.friend] Friend declarations shall not declare partial
specializations. */
if (CLASS_TYPE_P (friend_type)
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (friend_type)
&& uses_template_parms (friend_type))
{
error ("partial specialization %qT declared %<friend%>",
friend_type);
return;
}
if (TYPE_TEMPLATE_INFO (friend_type)
&& !PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (friend_type)))
{
error ("%qT is not a template", friend_type);
inform (location_of (friend_type), "previous declaration here");
if (TYPE_CLASS_SCOPE_P (friend_type)
&& CLASSTYPE_TEMPLATE_INFO (TYPE_CONTEXT (friend_type))
&& currently_open_class (TYPE_CONTEXT (friend_type)))
inform (input_location, "perhaps you need explicit template "
"arguments in your nested-name-specifier");
return;
}
}
/* It makes sense for a template class to be friends with itself,
that means the instantiations can be friendly. Other cases are
not so meaningful. */
if (!friend_depth && same_type_p (type, friend_type))
{
if (complain)
warning (0, "class %qT is implicitly friends with itself",
type);
return;
}
/* [temp.friend]
A friend of a class or class template can be a function or
class template, a specialization of a function template or
class template, or an ordinary (nontemplate) function or
class. */
if (!friend_depth)
;/* ok */
else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
{
if (TREE_CODE (TYPENAME_TYPE_FULLNAME (friend_type))
== TEMPLATE_ID_EXPR)
{
/* template <class U> friend class T::X<U>; */
/* [temp.friend]
Friend declarations shall not declare partial
specializations. */
error ("partial specialization %qT declared %<friend%>",
friend_type);
return;
}
else
{
/* We will figure this out later. */
bool template_member_p = false;
tree ctype = TYPE_CONTEXT (friend_type);
tree name = TYPE_IDENTIFIER (friend_type);
tree decl;
if (!uses_template_parms_level (ctype, class_template_depth
+ friend_depth))
template_member_p = true;
if (class_template_depth)
{
/* We rely on tsubst_friend_class to check the
validity of the declaration later. */
if (template_member_p)
friend_type
= make_unbound_class_template (ctype,
name,
current_template_parms,
tf_error);
else
friend_type
= make_typename_type (ctype, name, class_type, tf_error);
}
else
{
decl = lookup_member (ctype, name, 0, true, tf_warning_or_error);
if (!decl)
{
error ("%qT is not a member of %qT", name, ctype);
return;
}
if (template_member_p && !DECL_CLASS_TEMPLATE_P (decl))
{
error ("%qT is not a member class template of %qT",
name, ctype);
inform (DECL_SOURCE_LOCATION (decl),
"%qD declared here", decl);
return;
}
if (!template_member_p && (TREE_CODE (decl) != TYPE_DECL
|| !CLASS_TYPE_P (TREE_TYPE (decl))))
{
error ("%qT is not a nested class of %qT",
name, ctype);
inform (DECL_SOURCE_LOCATION (decl),
"%qD declared here", decl);
return;
}
friend_type = CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl));
}
}
}
else if (TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
{
/* template <class T> friend class T; */
error ("template parameter type %qT declared %<friend%>", friend_type);
return;
}
else if (TREE_CODE (friend_type) == TEMPLATE_TEMPLATE_PARM)
friend_type = TYPE_NAME (friend_type);
else if (!CLASSTYPE_TEMPLATE_INFO (friend_type))
{
/* template <class T> friend class A; where A is not a template */
error ("%q#T is not a template", friend_type);
return;
}
else
/* template <class T> friend class A; where A is a template */
friend_type = CLASSTYPE_TI_TEMPLATE (friend_type);
if (friend_type == error_mark_node)
return;
/* See if it is already a friend. */
for (classes = CLASSTYPE_FRIEND_CLASSES (type);
classes;
classes = TREE_CHAIN (classes))
{
tree probe = TREE_VALUE (classes);
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
{
if (friend_type == probe)
{
if (complain)
warning (OPT_Wredundant_decls,
"%qD is already a friend of %qT", probe, type);
break;
}
}
else if (TREE_CODE (probe) != TEMPLATE_DECL)
{
if (same_type_p (probe, friend_type))
{
if (complain)
warning (OPT_Wredundant_decls,
"%qT is already a friend of %qT", probe, type);
break;
}
}
}
if (!classes)
{
maybe_add_class_template_decl_list (type, friend_type, /*friend_p=*/1);
CLASSTYPE_FRIEND_CLASSES (type)
= tree_cons (NULL_TREE, friend_type, CLASSTYPE_FRIEND_CLASSES (type));
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
friend_type = TREE_TYPE (friend_type);
if (!uses_template_parms (type))
CLASSTYPE_BEFRIENDING_CLASSES (friend_type)
= tree_cons (NULL_TREE, type,
CLASSTYPE_BEFRIENDING_CLASSES (friend_type));
}
}
