void
add_friend (tree type, tree decl, bool complain)
{
tree typedecl;
tree list;
tree name;
tree ctx;
if (decl == error_mark_node)
return;
typedecl = TYPE_MAIN_DECL (type);
list = DECL_FRIENDLIST (typedecl);
name = DECL_NAME (decl);
type = TREE_TYPE (typedecl);
while (list)
{
if (name == FRIEND_NAME (list))
{
tree friends = FRIEND_DECLS (list);
for (; friends ; friends = TREE_CHAIN (friends))
{
if (decl == TREE_VALUE (friends))
{
if (complain)
warning (0, "%qD is already a friend of class %qT",
decl, type);
return;
}
}
maybe_add_class_template_decl_list (type, decl, /*friend_p=*/1);
TREE_VALUE (list) = tree_cons (NULL_TREE, decl,
TREE_VALUE (list));
return;
}
list = TREE_CHAIN (list);
}
ctx = DECL_CONTEXT (decl);
if (ctx && CLASS_TYPE_P (ctx) && !uses_template_parms (ctx))
perform_or_defer_access_check (TYPE_BINFO (ctx), decl, decl);
maybe_add_class_template_decl_list (type, decl, /*friend_p=*/1);
DECL_FRIENDLIST (typedecl)
= tree_cons (DECL_NAME (decl), build_tree_list (NULL_TREE, decl),
DECL_FRIENDLIST (typedecl));
if (!uses_template_parms (type))
DECL_BEFRIENDING_CLASSES (decl)
= tree_cons (NULL_TREE, type,
DECL_BEFRIENDING_CLASSES (decl));
}
tree
do_friend (tree ctype, tree declarator, tree decl,
tree attrlist, enum overload_flags flags,
bool funcdef_flag)
{
gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
gcc_assert (!ctype || MAYBE_CLASS_TYPE_P (ctype));
/* Every decl that gets here is a friend of something. */
DECL_FRIEND_P (decl) = 1;
/* Unfortunately, we have to handle attributes here. Normally we would
handle them in start_decl_1, but since this is a friend decl start_decl_1
never gets to see it. */
/* Set attributes here so if duplicate decl, will have proper attributes. */
cplus_decl_attributes (&decl, attrlist, 0);
if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
{
declarator = TREE_OPERAND (declarator, 0);
if (is_overloaded_fn (declarator))
declarator = DECL_NAME (get_first_fn (declarator));
}
if (ctype)
{
/* 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 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 void C<V>::f(W);
};
};
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'). */
int class_template_depth = template_class_depth (current_class_type);
int friend_depth = processing_template_decl - class_template_depth;
/* We will figure this out later. */
bool template_member_p = false;
tree cname = TYPE_NAME (ctype);
if (TREE_CODE (cname) == TYPE_DECL)
cname = DECL_NAME (cname);
/* A method friend. */
if (flags == NO_SPECIAL && declarator == cname)
DECL_CONSTRUCTOR_P (decl) = 1;
grokclassfn (ctype, decl, flags);
if (friend_depth)
{
if (!uses_template_parms_level (ctype, class_template_depth
+ friend_depth))
template_member_p = true;
}
/* A nested class may declare a member of an enclosing class
to be a friend, so we do lookup here even if CTYPE is in
the process of being defined. */
if (class_template_depth
|| COMPLETE_TYPE_P (ctype)
|| (CLASS_TYPE_P (ctype) && TYPE_BEING_DEFINED (ctype)))
{
if (DECL_TEMPLATE_INFO (decl))
/* DECL is a template specialization. No need to
build a new TEMPLATE_DECL. */
;
else if (class_template_depth)
/* We rely on tsubst_friend_function to check the
validity of the declaration later. */
decl = push_template_decl_real (decl, /*is_friend=*/true);
else
decl = check_classfn (ctype, decl,
template_member_p
? current_template_parms
: NULL_TREE);
if (template_member_p && decl && TREE_CODE (decl) == FUNCTION_DECL)
decl = DECL_TI_TEMPLATE (decl);
if (decl)
add_friend (current_class_type, decl, /*complain=*/true);
}
else
error ("member %qD declared as friend before type %qT defined",
decl, ctype);
}
/* A global friend.
@@ or possibly a friend from a base class ?!? */
else if (TREE_CODE (decl) == FUNCTION_DECL)
{
int is_friend_template = PROCESSING_REAL_TEMPLATE_DECL_P ();
/* Friends must all go through the overload machinery,
even though they may not technically be overloaded.
Note that because classes all wind up being top-level
in their scope, their friend wind up in top-level scope as well. */
if (funcdef_flag)
SET_DECL_FRIEND_CONTEXT (decl, current_class_type);
if (! DECL_USE_TEMPLATE (decl))
{
/* We must check whether the decl refers to template
arguments before push_template_decl_real adds a
reference to the containing template class. */
int warn = (warn_nontemplate_friend
&& ! funcdef_flag && ! is_friend_template
&& current_template_parms
&& uses_template_parms (decl));
if (is_friend_template
|| template_class_depth (current_class_type) != 0)
/* We can't call pushdecl for a template class, since in
general, such a declaration depends on template
parameters. Instead, we call pushdecl when the class
is instantiated. */
decl = push_template_decl_real (decl, /*is_friend=*/true);
else if (current_function_decl)
{
/* This must be a local class. 11.5p11:
If a friend declaration appears in a local class (9.8) and
the name specified is an unqualified name, a prior
declaration is looked up without considering scopes that
are outside the innermost enclosing non-class scope. For a
friend function declaration, if there is no prior
declaration, the program is ill-formed. */
tree t = lookup_name_innermost_nonclass_level (DECL_NAME (decl));
if (t)
decl = pushdecl_maybe_friend (decl, /*is_friend=*/true);
else
{
error ("friend declaration %qD in local class without "
"prior declaration", decl);
return error_mark_node;
}
}
else
{
/* We can't use pushdecl, as we might be in a template
class specialization, and pushdecl will insert an
unqualified friend decl into the template parameter
scope, rather than the namespace containing it. */
tree ns = decl_namespace_context (decl);
push_nested_namespace (ns);
decl = pushdecl_namespace_level (decl, /*is_friend=*/true);
pop_nested_namespace (ns);
}
if (warn)
{
static int explained;
bool warned;
warned = warning (OPT_Wnon_template_friend, "friend declaration "
"%q#D declares a non-template function", decl);
if (! explained && warned)
{
inform (input_location, "(if this is not what you intended, make sure "
"the function template has already been declared "
"and add <> after the function name here) ");
explained = 1;
}
}
}
if (decl == error_mark_node)
return error_mark_node;
add_friend (current_class_type,
is_friend_template ? DECL_TI_TEMPLATE (decl) : decl,
/*complain=*/true);
DECL_FRIEND_P (decl) = 1;
}
return decl;
}
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));
}
}
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));
}
}
