442 lines
13 KiB
C
442 lines
13 KiB
C
/* Help friends in C++.
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Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "config.h"
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#include "system.h"
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#include "tree.h"
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#include "rtl.h"
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#include "expr.h"
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#include "cp-tree.h"
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#include "flags.h"
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#include "output.h"
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#include "toplev.h"
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/* Friend data structures are described in cp-tree.h. */
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/* Returns non-zero if SUPPLICANT is a friend of TYPE. */
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int
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is_friend (type, supplicant)
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tree type, supplicant;
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{
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int declp;
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register tree list;
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tree context;
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if (supplicant == NULL_TREE || type == NULL_TREE)
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return 0;
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declp = DECL_P (supplicant);
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if (declp)
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/* It's a function decl. */
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{
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tree list = DECL_FRIENDLIST (TYPE_MAIN_DECL (type));
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tree name = DECL_NAME (supplicant);
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for (; list ; list = TREE_CHAIN (list))
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{
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if (name == FRIEND_NAME (list))
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{
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tree friends = FRIEND_DECLS (list);
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for (; friends ; friends = TREE_CHAIN (friends))
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{
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if (TREE_VALUE (friends) == NULL_TREE)
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continue;
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if (supplicant == TREE_VALUE (friends))
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return 1;
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/* Temporarily, we are more lenient to deal with
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nested friend functions, for which there can be
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more than one FUNCTION_DECL, despite being the
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same function. When that's fixed, this bit can
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go. */
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if (DECL_FUNCTION_MEMBER_P (supplicant)
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&& same_type_p (TREE_TYPE (supplicant),
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TREE_TYPE (TREE_VALUE (friends))))
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return 1;
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if (TREE_CODE (TREE_VALUE (friends)) == TEMPLATE_DECL
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&& is_specialization_of (supplicant,
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TREE_VALUE (friends)))
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return 1;
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}
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break;
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}
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}
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}
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else
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/* It's a type. */
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{
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/* Nested classes are implicitly friends of their enclosing types, as
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per core issue 45 (this is a change from the standard). */
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for (context = supplicant;
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context && TYPE_P (context);
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context = TYPE_CONTEXT (context))
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if (type == context)
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return 1;
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list = CLASSTYPE_FRIEND_CLASSES (TREE_TYPE (TYPE_MAIN_DECL (type)));
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for (; list ; list = TREE_CHAIN (list))
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{
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tree t = TREE_VALUE (list);
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if (TREE_CODE (t) == TEMPLATE_DECL ?
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is_specialization_of (TYPE_MAIN_DECL (supplicant), t) :
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same_type_p (supplicant, t))
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return 1;
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}
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}
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if (declp && DECL_FUNCTION_MEMBER_P (supplicant))
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context = DECL_CONTEXT (supplicant);
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else if (! declp)
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/* Local classes have the same access as the enclosing function. */
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context = decl_function_context (TYPE_MAIN_DECL (supplicant));
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else
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context = NULL_TREE;
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/* A namespace is not friend to anybody. */
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if (context && TREE_CODE (context) == NAMESPACE_DECL)
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context = NULL_TREE;
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if (context)
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return is_friend (type, context);
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return 0;
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}
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/* Add a new friend to the friends of the aggregate type TYPE.
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DECL is the FUNCTION_DECL of the friend being added. */
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void
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add_friend (type, decl)
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tree type, decl;
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{
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tree typedecl;
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tree list;
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tree name;
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if (decl == error_mark_node)
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return;
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typedecl = TYPE_MAIN_DECL (type);
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list = DECL_FRIENDLIST (typedecl);
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name = DECL_NAME (decl);
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type = TREE_TYPE (typedecl);
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while (list)
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{
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if (name == FRIEND_NAME (list))
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{
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tree friends = FRIEND_DECLS (list);
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for (; friends ; friends = TREE_CHAIN (friends))
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{
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if (decl == TREE_VALUE (friends))
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{
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warning ("`%D' is already a friend of class `%T'",
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decl, type);
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cp_warning_at ("previous friend declaration of `%D'",
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TREE_VALUE (friends));
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return;
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}
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}
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TREE_VALUE (list) = tree_cons (error_mark_node, decl,
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TREE_VALUE (list));
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return;
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}
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list = TREE_CHAIN (list);
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}
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DECL_FRIENDLIST (typedecl)
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= tree_cons (DECL_NAME (decl), build_tree_list (error_mark_node, decl),
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DECL_FRIENDLIST (typedecl));
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if (!uses_template_parms (type))
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DECL_BEFRIENDING_CLASSES (decl)
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= tree_cons (NULL_TREE, type,
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DECL_BEFRIENDING_CLASSES (decl));
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}
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/* Make FRIEND_TYPE a friend class to TYPE. If FRIEND_TYPE has already
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been defined, we make all of its member functions friends of
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TYPE. If not, we make it a pending friend, which can later be added
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when its definition is seen. If a type is defined, then its TYPE_DECL's
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DECL_UNDEFINED_FRIENDS contains a (possibly empty) list of friend
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classes that are not defined. If a type has not yet been defined,
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then the DECL_WAITING_FRIENDS contains a list of types
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waiting to make it their friend. Note that these two can both
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be in use at the same time! */
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void
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make_friend_class (type, friend_type)
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tree type, friend_type;
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{
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tree classes;
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int is_template_friend;
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if (! IS_AGGR_TYPE (friend_type))
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{
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error ("invalid type `%T' declared `friend'", friend_type);
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return;
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}
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if (CLASS_TYPE_P (friend_type)
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&& CLASSTYPE_TEMPLATE_SPECIALIZATION (friend_type)
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&& uses_template_parms (friend_type))
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{
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/* [temp.friend]
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Friend declarations shall not declare partial
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specializations. */
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error ("partial specialization `%T' declared `friend'",
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friend_type);
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return;
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}
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if (processing_template_decl > template_class_depth (type))
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/* If the TYPE is a template then it makes sense for it to be
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friends with itself; this means that each instantiation is
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friends with all other instantiations. */
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is_template_friend = 1;
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else if (same_type_p (type, friend_type))
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{
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pedwarn ("class `%T' is implicitly friends with itself",
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type);
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return;
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}
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else
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is_template_friend = 0;
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/* [temp.friend]
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A friend of a class or class template can be a function or
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class template, a specialization of a function template or
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class template, or an ordinary (nontemplate) function or
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class. */
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if (!is_template_friend)
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;/* ok */
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else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
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{
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/* template <class T> friend typename S<T>::X; */
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error ("typename type `%#T' declared `friend'", friend_type);
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return;
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}
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else if (TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
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{
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/* template <class T> friend class T; */
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error ("template parameter type `%T' declared `friend'", friend_type);
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return;
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}
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else if (!CLASSTYPE_TEMPLATE_INFO (friend_type))
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{
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/* template <class T> friend class A; where A is not a template */
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error ("`%#T' is not a template", friend_type);
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return;
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}
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GNU_xref_hier (type, friend_type, 0, 0, 1);
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if (is_template_friend)
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friend_type = CLASSTYPE_TI_TEMPLATE (friend_type);
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classes = CLASSTYPE_FRIEND_CLASSES (type);
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while (classes
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/* Stop if we find the same type on the list. */
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&& !(TREE_CODE (TREE_VALUE (classes)) == TEMPLATE_DECL ?
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friend_type == TREE_VALUE (classes) :
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same_type_p (TREE_VALUE (classes), friend_type)))
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classes = TREE_CHAIN (classes);
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if (classes)
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warning ("`%T' is already a friend of `%T'",
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TREE_VALUE (classes), type);
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else
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{
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CLASSTYPE_FRIEND_CLASSES (type)
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= tree_cons (NULL_TREE, friend_type, CLASSTYPE_FRIEND_CLASSES (type));
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if (is_template_friend)
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friend_type = TREE_TYPE (friend_type);
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if (!uses_template_parms (type))
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CLASSTYPE_BEFRIENDING_CLASSES (friend_type)
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= tree_cons (NULL_TREE, type,
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CLASSTYPE_BEFRIENDING_CLASSES (friend_type));
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}
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}
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/* Main friend processor. This is large, and for modularity purposes,
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has been removed from grokdeclarator. It returns `void_type_node'
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to indicate that something happened, though a FIELD_DECL is
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not returned.
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CTYPE is the class this friend belongs to.
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DECLARATOR is the name of the friend.
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DECL is the FUNCTION_DECL that the friend is.
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In case we are parsing a friend which is part of an inline
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definition, we will need to store PARM_DECL chain that comes
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with it into the DECL_ARGUMENTS slot of the FUNCTION_DECL.
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FLAGS is just used for `grokclassfn'.
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QUALS say what special qualifies should apply to the object
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pointed to by `this'. */
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tree
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do_friend (ctype, declarator, decl, parmdecls, attrlist,
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flags, quals, funcdef_flag)
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tree ctype, declarator, decl, parmdecls, attrlist;
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enum overload_flags flags;
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tree quals;
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int funcdef_flag;
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{
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int is_friend_template = 0;
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/* Every decl that gets here is a friend of something. */
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DECL_FRIEND_P (decl) = 1;
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if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
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{
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declarator = TREE_OPERAND (declarator, 0);
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if (TREE_CODE (declarator) == LOOKUP_EXPR)
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declarator = TREE_OPERAND (declarator, 0);
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if (is_overloaded_fn (declarator))
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declarator = DECL_NAME (get_first_fn (declarator));
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}
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if (TREE_CODE (decl) != FUNCTION_DECL)
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abort ();
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is_friend_template = PROCESSING_REAL_TEMPLATE_DECL_P ();
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if (ctype)
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{
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tree cname = TYPE_NAME (ctype);
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if (TREE_CODE (cname) == TYPE_DECL)
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cname = DECL_NAME (cname);
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/* A method friend. */
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if (flags == NO_SPECIAL && ctype && declarator == cname)
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DECL_CONSTRUCTOR_P (decl) = 1;
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/* This will set up DECL_ARGUMENTS for us. */
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grokclassfn (ctype, decl, flags, quals);
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if (is_friend_template)
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decl = DECL_TI_TEMPLATE (push_template_decl (decl));
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else if (template_class_depth (current_class_type))
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decl = push_template_decl_real (decl, /*is_friend=*/1);
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/* We can't do lookup in a type that involves template
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parameters. Instead, we rely on tsubst_friend_function
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to check the validity of the declaration later. */
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if (processing_template_decl)
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add_friend (current_class_type, decl);
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/* A nested class may declare a member of an enclosing class
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to be a friend, so we do lookup here even if CTYPE is in
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the process of being defined. */
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else if (COMPLETE_TYPE_P (ctype) || TYPE_BEING_DEFINED (ctype))
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{
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decl = check_classfn (ctype, decl);
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if (decl)
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add_friend (current_class_type, decl);
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}
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else
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error ("member `%D' declared as friend before type `%T' defined",
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decl, ctype);
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}
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/* A global friend.
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@@ or possibly a friend from a base class ?!? */
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else if (TREE_CODE (decl) == FUNCTION_DECL)
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{
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/* Friends must all go through the overload machinery,
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even though they may not technically be overloaded.
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Note that because classes all wind up being top-level
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in their scope, their friend wind up in top-level scope as well. */
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DECL_ARGUMENTS (decl) = parmdecls;
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if (funcdef_flag)
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SET_DECL_FRIEND_CONTEXT (decl, current_class_type);
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if (! DECL_USE_TEMPLATE (decl))
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{
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/* We must check whether the decl refers to template
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arguments before push_template_decl_real adds a
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reference to the containing template class. */
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int warn = (warn_nontemplate_friend
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&& ! funcdef_flag && ! is_friend_template
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&& current_template_parms
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&& uses_template_parms (decl));
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if (is_friend_template
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|| template_class_depth (current_class_type) != 0)
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/* We can't call pushdecl for a template class, since in
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general, such a declaration depends on template
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parameters. Instead, we call pushdecl when the class
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is instantiated. */
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decl = push_template_decl_real (decl, /*is_friend=*/1);
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else if (current_function_decl)
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/* This must be a local class, so pushdecl will be ok, and
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insert an unqualified friend into the local scope
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(rather than the containing namespace scope, which the
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next choice will do). */
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decl = pushdecl (decl);
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else
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{
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/* We can't use pushdecl, as we might be in a template
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class specialization, and pushdecl will insert an
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unqualified friend decl into the template parameter
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scope, rather than the namespace containing it. */
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tree ns = decl_namespace_context (decl);
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push_nested_namespace (ns);
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decl = pushdecl_namespace_level (decl);
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pop_nested_namespace (ns);
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}
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if (warn)
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{
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static int explained;
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warning ("friend declaration `%#D' declares a non-template function", decl);
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if (! explained)
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{
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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");
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explained = 1;
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}
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}
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}
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add_friend (current_class_type,
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is_friend_template ? DECL_TI_TEMPLATE (decl) : decl);
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DECL_FRIEND_P (decl) = 1;
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}
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/* Unfortunately, we have to handle attributes here. Normally we would
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handle them in start_decl_1, but since this is a friend decl start_decl_1
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never gets to see it. */
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/* Set attributes here so if duplicate decl, will have proper attributes. */
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cplus_decl_attributes (&decl, attrlist, 0);
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return decl;
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}
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