1 /* Help friends in C++.
2 Copyright (C) 1997 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
33 static void add_friend PROTO((tree, tree));
34 static void add_friends PROTO((tree, tree, tree));
36 /* Friend data structures are described in cp-tree.h. */
39 is_friend (type, supplicant)
40 tree type, supplicant;
45 if (supplicant == NULL_TREE || type == NULL_TREE)
48 declp = (TREE_CODE_CLASS (TREE_CODE (supplicant)) == 'd');
51 /* It's a function decl. */
53 tree list = DECL_FRIENDLIST (TYPE_MAIN_DECL (type));
54 tree name = DECL_NAME (supplicant);
57 if (DECL_FUNCTION_MEMBER_P (supplicant))
58 ctype = DECL_CLASS_CONTEXT (supplicant);
62 for (; list ; list = TREE_CHAIN (list))
64 if (name == TREE_PURPOSE (list))
66 tree friends = TREE_VALUE (list);
67 for (; friends ; friends = TREE_CHAIN (friends))
69 if (ctype == TREE_PURPOSE (friends))
72 if (TREE_VALUE (friends) == NULL_TREE)
75 if (TREE_CODE (TREE_VALUE (friends)) == TEMPLATE_DECL)
79 /* Perhaps this function is a specialization of
83 t = DECL_TEMPLATE_INFO (t) ?
84 DECL_TI_TEMPLATE (t) : NULL_TREE)
85 /* FIXME: The use of comptypes here, and below, is
86 bogus, since two specializations of a
87 template parameter with non-type parameters
88 may have the same type, but be different. */
89 if (comptypes (TREE_TYPE (t),
90 TREE_TYPE (TREE_VALUE (friends)), 1))
96 if (comptypes (TREE_TYPE (supplicant),
97 TREE_TYPE (TREE_VALUE (friends)), 1))
107 if (type == supplicant)
110 list = CLASSTYPE_FRIEND_CLASSES (TREE_TYPE (TYPE_MAIN_DECL (type)));
111 for (; list ; list = TREE_CHAIN (list))
112 if (supplicant == TREE_VALUE (list))
121 /* Are we a nested or local class? If so, we aren't friends
123 if (IS_AGGR_TYPE (supplicant))
126 context = DECL_CONTEXT (TYPE_MAIN_DECL (supplicant));
128 else if (DECL_FUNCTION_MEMBER_P (supplicant))
129 context = DECL_CLASS_CONTEXT (supplicant);
134 return is_friend (type, context);
140 /* Add a new friend to the friends of the aggregate type TYPE.
141 DECL is the FUNCTION_DECL of the friend being added. */
144 add_friend (type, decl)
147 tree typedecl = TYPE_MAIN_DECL (type);
148 tree list = DECL_FRIENDLIST (typedecl);
149 tree name = DECL_NAME (decl);
153 if (name == TREE_PURPOSE (list))
155 tree friends = TREE_VALUE (list);
156 for (; friends ; friends = TREE_CHAIN (friends))
158 if (decl == TREE_VALUE (friends))
160 cp_warning ("`%D' is already a friend of class `%T'",
162 cp_warning_at ("previous friend declaration of `%D'",
163 TREE_VALUE (friends));
167 TREE_VALUE (list) = tree_cons (error_mark_node, decl,
171 list = TREE_CHAIN (list);
173 DECL_FRIENDLIST (typedecl)
174 = tree_cons (DECL_NAME (decl), build_tree_list (error_mark_node, decl),
175 DECL_FRIENDLIST (typedecl));
176 if (DECL_NAME (decl) == ansi_opname[(int) MODIFY_EXPR])
178 tree parmtypes = TYPE_ARG_TYPES (TREE_TYPE (decl));
179 TYPE_HAS_ASSIGNMENT (TREE_TYPE (typedecl)) = 1;
180 if (parmtypes && TREE_CHAIN (parmtypes))
182 tree parmtype = TREE_VALUE (TREE_CHAIN (parmtypes));
183 if (TREE_CODE (parmtype) == REFERENCE_TYPE
184 && TREE_TYPE (parmtypes) == TREE_TYPE (typedecl))
185 TYPE_HAS_ASSIGN_REF (TREE_TYPE (typedecl)) = 1;
190 /* Declare that every member function NAME in FRIEND_TYPE
191 (which may be NULL_TREE) is a friend of type TYPE. */
194 add_friends (type, name, friend_type)
195 tree type, name, friend_type;
197 tree typedecl = TYPE_MAIN_DECL (type);
198 tree list = DECL_FRIENDLIST (typedecl);
202 if (name == TREE_PURPOSE (list))
204 tree friends = TREE_VALUE (list);
205 while (friends && TREE_PURPOSE (friends) != friend_type)
206 friends = TREE_CHAIN (friends);
210 warning ("method `%s::%s' is already a friend of class",
211 TYPE_NAME_STRING (friend_type),
212 IDENTIFIER_POINTER (name));
214 warning ("function `%s' is already a friend of class `%s'",
215 IDENTIFIER_POINTER (name),
216 IDENTIFIER_POINTER (DECL_NAME (typedecl)));
219 TREE_VALUE (list) = tree_cons (friend_type, NULL_TREE,
223 list = TREE_CHAIN (list);
225 DECL_FRIENDLIST (typedecl)
227 build_tree_list (friend_type, NULL_TREE),
228 DECL_FRIENDLIST (typedecl));
229 if (! strncmp (IDENTIFIER_POINTER (name),
230 IDENTIFIER_POINTER (ansi_opname[(int) MODIFY_EXPR]),
231 strlen (IDENTIFIER_POINTER (ansi_opname[(int) MODIFY_EXPR]))))
233 TYPE_HAS_ASSIGNMENT (TREE_TYPE (typedecl)) = 1;
234 sorry ("declaring \"friend operator =\" will not find \"operator = (X&)\" if it exists");
238 /* Make FRIEND_TYPE a friend class to TYPE. If FRIEND_TYPE has already
239 been defined, we make all of its member functions friends of
240 TYPE. If not, we make it a pending friend, which can later be added
241 when its definition is seen. If a type is defined, then its TYPE_DECL's
242 DECL_UNDEFINED_FRIENDS contains a (possibly empty) list of friend
243 classes that are not defined. If a type has not yet been defined,
244 then the DECL_WAITING_FRIENDS contains a list of types
245 waiting to make it their friend. Note that these two can both
246 be in use at the same time! */
249 make_friend_class (type, friend_type)
250 tree type, friend_type;
254 if (IS_SIGNATURE (type))
256 error ("`friend' declaration in signature definition");
259 if (IS_SIGNATURE (friend_type))
261 error ("signature type `%s' declared `friend'",
262 IDENTIFIER_POINTER (TYPE_IDENTIFIER (friend_type)));
265 if (type == friend_type)
267 pedwarn ("class `%s' is implicitly friends with itself",
268 TYPE_NAME_STRING (type));
272 GNU_xref_hier (TYPE_NAME_STRING (type),
273 TYPE_NAME_STRING (friend_type), 0, 0, 1);
275 classes = CLASSTYPE_FRIEND_CLASSES (type);
276 while (classes && TREE_VALUE (classes) != friend_type)
277 classes = TREE_CHAIN (classes);
279 warning ("class `%s' is already friends with class `%s'",
280 TYPE_NAME_STRING (TREE_VALUE (classes)), TYPE_NAME_STRING (type));
283 CLASSTYPE_FRIEND_CLASSES (type)
284 = tree_cons (NULL_TREE, friend_type, CLASSTYPE_FRIEND_CLASSES (type));
288 /* Main friend processor. This is large, and for modularity purposes,
289 has been removed from grokdeclarator. It returns `void_type_node'
290 to indicate that something happened, though a FIELD_DECL is
293 CTYPE is the class this friend belongs to.
295 DECLARATOR is the name of the friend.
297 DECL is the FUNCTION_DECL that the friend is.
299 In case we are parsing a friend which is part of an inline
300 definition, we will need to store PARM_DECL chain that comes
301 with it into the DECL_ARGUMENTS slot of the FUNCTION_DECL.
303 FLAGS is just used for `grokclassfn'.
305 QUALS say what special qualifies should apply to the object
306 pointed to by `this'. */
309 do_friend (ctype, declarator, decl, parmdecls, flags, quals, funcdef_flag)
310 tree ctype, declarator, decl, parmdecls;
311 enum overload_flags flags;
315 int is_friend_template = 0;
317 /* Every decl that gets here is a friend of something. */
318 DECL_FRIEND_P (decl) = 1;
320 if (TREE_CODE (decl) == FUNCTION_DECL)
321 is_friend_template = processing_template_decl >
322 template_class_depth (current_class_type);
326 tree cname = TYPE_NAME (ctype);
327 if (TREE_CODE (cname) == TYPE_DECL)
328 cname = DECL_NAME (cname);
330 /* A method friend. */
331 if (TREE_CODE (decl) == FUNCTION_DECL)
333 if (flags == NO_SPECIAL && ctype && declarator == cname)
334 DECL_CONSTRUCTOR_P (decl) = 1;
336 /* This will set up DECL_ARGUMENTS for us. */
337 grokclassfn (ctype, cname, decl, flags, quals);
339 if (is_friend_template)
340 decl = DECL_TI_TEMPLATE (push_template_decl (decl));
342 if (TYPE_SIZE (ctype) != 0
343 && template_class_depth (ctype) == 0)
344 decl = check_classfn (ctype, decl);
346 if (TREE_TYPE (decl) != error_mark_node)
348 if (TYPE_SIZE (ctype) || template_class_depth (ctype) > 0)
349 add_friend (current_class_type, decl);
351 cp_error ("member `%D' declared as friend before type `%T' defined",
357 /* Possibly a bunch of method friends. */
359 /* Get the class they belong to. */
360 tree ctype = IDENTIFIER_TYPE_VALUE (cname);
361 tree fields = lookup_fnfields (TYPE_BINFO (ctype), declarator, 0);
364 add_friends (current_class_type, declarator, ctype);
366 error ("method `%s' is not a member of class `%s'",
367 IDENTIFIER_POINTER (declarator),
368 IDENTIFIER_POINTER (cname));
369 decl = void_type_node;
372 else if (TREE_CODE (decl) == FUNCTION_DECL
373 && ((IDENTIFIER_LENGTH (declarator) == 4
374 && IDENTIFIER_POINTER (declarator)[0] == 'm'
375 && ! strcmp (IDENTIFIER_POINTER (declarator), "main"))
376 || (IDENTIFIER_LENGTH (declarator) > 10
377 && IDENTIFIER_POINTER (declarator)[0] == '_'
378 && IDENTIFIER_POINTER (declarator)[1] == '_'
379 && strncmp (IDENTIFIER_POINTER (declarator)+2,
380 "builtin_", 8) == 0)))
382 /* raw "main", and builtin functions never gets overloaded,
383 but they can become friends. */
384 add_friend (current_class_type, decl);
385 DECL_FRIEND_P (decl) = 1;
386 decl = void_type_node;
389 @@ or possibly a friend from a base class ?!? */
390 else if (TREE_CODE (decl) == FUNCTION_DECL)
392 /* Friends must all go through the overload machinery,
393 even though they may not technically be overloaded.
395 Note that because classes all wind up being top-level
396 in their scope, their friend wind up in top-level scope as well. */
397 DECL_ASSEMBLER_NAME (decl)
398 = build_decl_overload (declarator, TYPE_ARG_TYPES (TREE_TYPE (decl)),
399 TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE);
400 DECL_ARGUMENTS (decl) = parmdecls;
402 DECL_CLASS_CONTEXT (decl) = current_class_type;
404 if (! DECL_USE_TEMPLATE (decl))
406 /* We can call pushdecl here, because the TREE_CHAIN of this
407 FUNCTION_DECL is not needed for other purposes. Don't do this
408 for a template instantiation. */
409 if (!is_friend_template)
411 /* However, we don't call pushdecl() for a friend
412 function of a template class, since in general,
413 such a declaration depends on template
414 parameters. Instead, we call pushdecl when the
415 class is instantiated. */
416 if (template_class_depth (current_class_type) == 0)
417 decl = pushdecl (decl);
420 decl = push_template_decl (decl);
422 if (! funcdef_flag && ! flag_guiding_decls && ! is_friend_template
423 && current_template_parms && uses_template_parms (decl))
425 static int explained;
426 cp_warning ("friend declaration `%#D'", decl);
427 warning (" declares a non-template function");
430 warning (" unless you compile with -fguiding-decls");
431 warning (" or add <> after the function name");
437 make_decl_rtl (decl, NULL_PTR, 1);
438 add_friend (current_class_type,
439 is_friend_template ? DECL_TI_TEMPLATE (decl) : decl);
440 DECL_FRIEND_P (decl) = 1;
444 /* @@ Should be able to ingest later definitions of this function
446 tree decl = lookup_name_nonclass (declarator);
447 if (decl == NULL_TREE)
449 warning ("implicitly declaring `%s' as struct",
450 IDENTIFIER_POINTER (declarator));
451 decl = xref_tag (record_type_node, declarator, NULL_TREE, 1);
452 decl = TYPE_MAIN_DECL (decl);
455 /* Allow abbreviated declarations of overloaded functions,
456 but not if those functions are really class names. */
457 if (TREE_CODE (decl) == TREE_LIST && TREE_TYPE (TREE_PURPOSE (decl)))
459 warning ("`friend %s' archaic, use `friend class %s' instead",
460 IDENTIFIER_POINTER (declarator),
461 IDENTIFIER_POINTER (declarator));
462 decl = TREE_TYPE (TREE_PURPOSE (decl));
465 if (TREE_CODE (decl) == TREE_LIST)
466 add_friends (current_class_type, TREE_PURPOSE (decl), NULL_TREE);
468 make_friend_class (current_class_type, TREE_TYPE (decl));
469 decl = void_type_node;