/* Help friends in C++.
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
- Free Software Foundation, Inc.
+ Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
+ 2007, 2008, 2010, 2011 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "rtl.h"
-#include "expr.h"
#include "cp-tree.h"
#include "flags.h"
#include "output.h"
-#include "toplev.h"
/* Friend data structures are described in cp-tree.h. */
/* Returns nonzero if SUPPLICANT is a friend of TYPE. */
int
-is_friend (type, supplicant)
- tree type, supplicant;
+is_friend (tree type, tree supplicant)
{
int declp;
- register tree list;
+ tree list;
tree context;
if (supplicant == NULL_TREE || type == NULL_TREE)
tree friends = FRIEND_DECLS (list);
for (; friends ; friends = TREE_CHAIN (friends))
{
- if (TREE_VALUE (friends) == NULL_TREE)
- continue;
+ tree this_friend = TREE_VALUE (friends);
- if (supplicant == TREE_VALUE (friends))
- return 1;
+ if (this_friend == NULL_TREE)
+ continue;
- /* Temporarily, we are more lenient to deal with
- nested friend functions, for which there can be
- more than one FUNCTION_DECL, despite being the
- same function. When that's fixed, this bit can
- go. */
- if (DECL_FUNCTION_MEMBER_P (supplicant)
- && same_type_p (TREE_TYPE (supplicant),
- TREE_TYPE (TREE_VALUE (friends))))
+ if (supplicant == this_friend)
return 1;
- if (TREE_CODE (TREE_VALUE (friends)) == TEMPLATE_DECL
- && is_specialization_of (supplicant,
- TREE_VALUE (friends)))
+ if (is_specialization_of_friend (supplicant, this_friend))
return 1;
}
break;
else
/* It's a type. */
{
- /* Nested classes are implicitly friends of their enclosing types, as
- per core issue 45 (this is a change from the standard). */
- for (context = supplicant;
- context && TYPE_P (context);
- context = TYPE_CONTEXT (context))
- if (type == context)
- return 1;
-
+ 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 (TYPE_MAIN_DECL (supplicant), t) :
+ if (TREE_CODE (t) == TEMPLATE_DECL ?
+ is_specialization_of_friend (TYPE_MAIN_DECL (supplicant), t) :
same_type_p (supplicant, t))
return 1;
}
- }
+ }
- if (declp && DECL_FUNCTION_MEMBER_P (supplicant))
- context = DECL_CONTEXT (supplicant);
- else if (! declp)
- /* Local classes have the same access as the enclosing function. */
- context = decl_function_context (TYPE_MAIN_DECL (supplicant));
+ if (declp)
+ {
+ if (DECL_FUNCTION_MEMBER_P (supplicant))
+ context = DECL_CONTEXT (supplicant);
+ else
+ context = NULL_TREE;
+ }
else
- context = NULL_TREE;
+ {
+ 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)
}
/* Add a new friend to the friends of the aggregate type TYPE.
- DECL is the FUNCTION_DECL of the friend being added. */
+ DECL is the FUNCTION_DECL of the friend being added.
+
+ If COMPLAIN is true, warning about duplicate friend is issued.
+ We want to have this diagnostics during parsing but not
+ when a template is being instantiated. */
void
-add_friend (type, decl)
- tree type, decl;
+add_friend (tree type, tree decl, bool complain)
{
tree typedecl;
tree list;
tree name;
+ tree ctx;
if (decl == error_mark_node)
return;
{
if (decl == TREE_VALUE (friends))
{
- warning ("`%D' is already a friend of class `%T'",
- decl, type);
- cp_warning_at ("previous friend declaration of `%D'",
- 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 (error_mark_node, decl,
+ 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 (error_mark_node, decl),
+ = tree_cons (DECL_NAME (decl), build_tree_list (NULL_TREE, decl),
DECL_FRIENDLIST (typedecl));
if (!uses_template_parms (type))
- DECL_BEFRIENDING_CLASSES (decl)
+ DECL_BEFRIENDING_CLASSES (decl)
= tree_cons (NULL_TREE, type,
DECL_BEFRIENDING_CLASSES (decl));
}
classes that are not defined. If a type has not yet been defined,
then the DECL_WAITING_FRIENDS contains a list of types
waiting to make it their friend. Note that these two can both
- be in use at the same time! */
+ be in use at the same time!
+
+ If COMPLAIN is true, warning about duplicate friend is issued.
+ We want to have this diagnostics during parsing but not
+ when a template is being instantiated. */
void
-make_friend_class (type, friend_type)
- tree type, friend_type;
+make_friend_class (tree type, tree friend_type, bool complain)
{
tree classes;
- int is_template_friend;
- if (! IS_AGGR_TYPE (friend_type))
+ /* 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 `%T' declared `friend'", friend_type);
+ /* 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++0x mode. */
+ if (cxx_dialect < cxx0x)
+ pedwarn (input_location, complain ? 0 : OPT_pedantic,
+ "invalid type %qT declared %<friend%>", friend_type);
return;
}
- if (processing_template_decl > template_class_depth (type))
+ friend_type = cv_unqualified (friend_type);
+
+ 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. */
/* [temp.friend]
Friend declarations shall not declare partial
specializations. */
- error ("partial specialization `%T' declared `friend'",
+ error ("partial specialization %qT declared %<friend%>",
friend_type);
return;
}
-
- is_template_friend = 1;
}
else if (same_type_p (type, friend_type))
{
- pedwarn ("class `%T' is implicitly friends with itself",
- type);
+ if (complain)
+ warning (0, "class %qT is implicitly friends with itself",
+ type);
return;
}
- else
- is_template_friend = 0;
/* [temp.friend]
class template, a specialization of a function template or
class template, or an ordinary (nontemplate) function or
class. */
- if (!is_template_friend)
+ if (!friend_depth)
;/* ok */
else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
{
- /* template <class T> friend typename S<T>::X; */
- error ("typename type `%#T' declared `friend'", friend_type);
- return;
+ 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);
+ 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 `%T' declared `friend'", friend_type);
+ 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 ("`%#T' is not a template", friend_type);
+ error ("%q#T is not a template", friend_type);
return;
}
-
- if (is_template_friend)
+ else
+ /* template <class T> friend class A; where A is a template */
friend_type = CLASSTYPE_TI_TEMPLATE (friend_type);
- classes = CLASSTYPE_FRIEND_CLASSES (type);
- while (classes
- /* Stop if we find the same type on the list. */
- && !(TREE_CODE (TREE_VALUE (classes)) == TEMPLATE_DECL ?
- friend_type == TREE_VALUE (classes) :
- same_type_p (TREE_VALUE (classes), friend_type)))
- classes = TREE_CHAIN (classes);
- if (classes)
- warning ("`%T' is already a friend of `%T'",
- TREE_VALUE (classes), type);
- else
+ 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 (is_template_friend)
+ 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));
+ = tree_cons (NULL_TREE, type,
+ CLASSTYPE_BEFRIENDING_CLASSES (friend_type));
}
}
-/* Main friend processor. This is large, and for modularity purposes,
- has been removed from grokdeclarator. It returns `void_type_node'
- to indicate that something happened, though a FIELD_DECL is
- not returned.
-
- CTYPE is the class this friend belongs to.
-
- DECLARATOR is the name of the friend.
-
- DECL is the FUNCTION_DECL that the friend is.
-
- In case we are parsing a friend which is part of an inline
- definition, we will need to store PARM_DECL chain that comes
- with it into the DECL_ARGUMENTS slot of the FUNCTION_DECL.
-
- FLAGS is just used for `grokclassfn'.
-
- QUALS say what special qualifies should apply to the object
- pointed to by `this'. */
+/* Record DECL (a FUNCTION_DECL) as a friend of the
+ CURRENT_CLASS_TYPE. If DECL is a member function, CTYPE is the
+ class of which it is a member, as named in the friend declaration.
+ DECLARATOR is the name of the friend. FUNCDEF_FLAG is true if the
+ friend declaration is a definition of the function. FLAGS is as
+ for grokclass fn. */
tree
-do_friend (ctype, declarator, decl, parmdecls, attrlist,
- flags, quals, funcdef_flag)
- tree ctype, declarator, decl, parmdecls, attrlist;
- enum overload_flags flags;
- tree quals;
- int funcdef_flag;
+do_friend (tree ctype, tree declarator, tree decl,
+ tree attrlist, enum overload_flags flags,
+ bool funcdef_flag)
{
- int is_friend_template = 0;
+ 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 (TREE_CODE (declarator) == LOOKUP_EXPR)
- declarator = TREE_OPERAND (declarator, 0);
if (is_overloaded_fn (declarator))
declarator = DECL_NAME (get_first_fn (declarator));
}
- if (TREE_CODE (decl) != FUNCTION_DECL)
- abort ();
-
- is_friend_template = PROCESSING_REAL_TEMPLATE_DECL_P ();
-
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 && ctype && declarator == cname)
+ if (flags == NO_SPECIAL && declarator == cname)
DECL_CONSTRUCTOR_P (decl) = 1;
- /* This will set up DECL_ARGUMENTS for us. */
- grokclassfn (ctype, decl, flags, quals);
+ grokclassfn (ctype, decl, flags);
- if (is_friend_template)
- decl = DECL_TI_TEMPLATE (push_template_decl (decl));
- else if (template_class_depth (current_class_type))
- decl = push_template_decl_real (decl, /*is_friend=*/1);
+ if (friend_depth)
+ {
+ if (!uses_template_parms_level (ctype, class_template_depth
+ + friend_depth))
+ template_member_p = true;
+ }
- /* We can't do lookup in a type that involves template
- parameters. Instead, we rely on tsubst_friend_function
- to check the validity of the declaration later. */
- if (processing_template_decl)
- add_friend (current_class_type, decl);
/* 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. */
- else if (COMPLETE_TYPE_P (ctype) || TYPE_BEING_DEFINED (ctype))
+ if (class_template_depth
+ || COMPLETE_TYPE_P (ctype)
+ || (CLASS_TYPE_P (ctype) && TYPE_BEING_DEFINED (ctype)))
{
- decl = check_classfn (ctype, decl);
+ 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);
+ add_friend (current_class_type, decl, /*complain=*/true);
}
else
- error ("member `%D' declared as friend before type `%T' defined",
+ 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. */
- DECL_ARGUMENTS (decl) = parmdecls;
if (funcdef_flag)
SET_DECL_FRIEND_CONTEXT (decl, current_class_type);
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=*/1);
+ decl = push_template_decl_real (decl, /*is_friend=*/true);
else if (current_function_decl)
- /* This must be a local class, so pushdecl will be ok, and
- insert an unqualified friend into the local scope
- (rather than the containing namespace scope, which the
- next choice will do). */
- decl = pushdecl (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. */
+ 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);
+ decl = pushdecl_namespace_level (decl, /*is_friend=*/true);
pop_nested_namespace (ns);
}
if (warn)
{
static int explained;
- warning ("friend declaration `%#D' declares a non-template function", decl);
- if (! explained)
+ bool warned;
+
+ warned = warning (OPT_Wnon_template_friend, "friend declaration "
+ "%q#D declares a non-template function", decl);
+ if (! explained && warned)
{
- warning ("(if this is not what you intended, make sure the function template has already been declared and add <> after the function name here) -Wno-non-template-friend disables this warning");
+ 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;
}
}
}
- add_friend (current_class_type,
- is_friend_template ? DECL_TI_TEMPLATE (decl) : decl);
+ 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;
}
- /* 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);
-
return decl;
}