| blob | 7a331479d8b515bbe7e2aaf474c27a55a12d0554 |
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
48 /* The type of functions taking a tree, and some additional data, and
49 returning an int. */
52 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
53 instantiations have been deferred, either because their definitions
54 were not yet available, or because we were putting off doing the work. */
58 };
73 /* Live only within one (recursive) call to tsubst_expr. We use
74 this to pass the statement expression node from the STMT_EXPR
75 to the EXPR_STMT that is its result. */
78 /* A map from local variable declarations in the body of the template
79 presently being instantiated to the corresponding instantiated
80 local variables. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
91 htab_t decl_specializations;
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
129 tree);
189 location_t);
194 /* Make the current scope suitable for access checking when we are
195 processing T. T can be FUNCTION_DECL for instantiated function
196 template, or VAR_DECL for static member variable (need by
197 instantiate_decl). */
199 static void
201 {
209 else
213 {
214 saved_access_scope = tree_cons
217 }
218 }
220 /* Restore the scope set up by push_access_scope. T is the node we
221 are processing. */
223 static void
225 {
227 {
230 }
234 else
236 }
238 /* Do any processing required when DECL (a member template
239 declaration) is finished. Returns the TEMPLATE_DECL corresponding
240 to DECL, unless it is a specialization, in which case the DECL
241 itself is returned. */
243 tree
245 {
252 {
253 tree type;
261 {
265 }
267 }
271 {
273 {
276 }
277 else
279 }
280 else
284 }
286 /* Create a template info node. */
288 tree
290 {
295 }
297 /* Return the template info node corresponding to T, whatever T is. */
299 tree
301 {
319 }
321 /* Returns the template nesting level of the indicated class TYPE.
323 For example, in:
324 template <class T>
325 struct A
326 {
327 template <class U>
328 struct B {};
329 };
331 A<T>::B<U> has depth two, while A<T> has depth one.
332 Both A<T>::B<int> and A<int>::B<U> have depth one, if
333 they are instantiations, not specializations.
335 This function is guaranteed to return 0 if passed NULL_TREE so
336 that, for example, `template_class_depth (current_class_type)' is
337 always safe. */
339 int
341 {
348 {
354 }
357 }
359 /* Subroutine of maybe_begin_member_template_processing.
360 Returns true if processing DECL needs us to push template parms. */
362 static bool
364 {
370 }
372 /* Subroutine of maybe_begin_member_template_processing.
373 Push the template parms in PARMS, starting from LEVELS steps into the
374 chain, and ending at the beginning, since template parms are listed
375 innermost first. */
377 static void
379 {
387 current_template_parms
393 NULL);
395 {
404 {
411 {
412 /* Make a CONST_DECL as is done in process_template_parm.
413 It is ugly that we recreate this here; the original
414 version built in process_template_parm is no longer
415 available. */
425 }
430 }
431 }
432 }
434 /* Restore the template parameter context for a member template or
435 a friend template defined in a class definition. */
437 void
439 {
440 tree parms;
444 {
449 {
452 }
455 }
457 /* Remember how many levels of template parameters we pushed so that
458 we can pop them later. */
460 }
462 /* Undo the effects of maybe_begin_member_template_processing. */
464 void
466 {
475 {
479 }
480 }
482 /* Return a new template argument vector which contains all of ARGS,
483 but has as its innermost set of arguments the EXTRA_ARGS. */
485 static tree
487 {
488 tree new_args;
506 }
508 /* Like add_to_template_args, but only the outermost ARGS are added to
509 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
510 (EXTRA_ARGS) levels are added. This function is used to combine
511 the template arguments from a partial instantiation with the
512 template arguments used to attain the full instantiation from the
513 partial instantiation. */
515 static tree
517 {
518 tree new_args;
520 /* If there are more levels of EXTRA_ARGS than there are ARGS,
521 something very fishy is going on. */
524 /* If *all* the new arguments will be the EXTRA_ARGS, just return
525 them. */
529 /* For the moment, we make ARGS look like it contains fewer levels. */
534 /* Now, we restore ARGS to its full dimensions. */
538 }
540 /* Return the N levels of innermost template arguments from the ARGS. */
542 tree
544 {
545 tree new_args;
551 /* If N is 1, just return the innermost set of template arguments. */
555 /* If we're not removing anything, just return the arguments we were
556 given. */
562 /* Make a new set of arguments, not containing the outer arguments. */
569 }
571 /* The inverse of get_innermost_template_args: Return all but the innermost
572 EXTRA_LEVELS levels of template arguments from the ARGS. */
574 static tree
576 {
577 tree new_args;
583 /* If N is 1, just return the outermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
593 /* Make a new set of arguments, not containing the inner arguments. */
600 }
602 /* We've got a template header coming up; push to a new level for storing
603 the parms. */
605 void
607 {
608 /* We use a non-tag-transparent scope here, which causes pushtag to
609 put tags in this scope, rather than in the enclosing class or
610 namespace scope. This is the right thing, since we want
611 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
612 global template class, push_template_decl handles putting the
613 TEMPLATE_DECL into top-level scope. For a nested template class,
614 e.g.:
616 template <class T> struct S1 {
617 template <class T> struct S2 {};
618 };
620 pushtag contains special code to call pushdecl_with_scope on the
621 TEMPLATE_DECL for S2. */
626 }
628 /* This routine is called when a specialization is declared. If it is
629 invalid to declare a specialization here, an error is reported and
630 false is returned, otherwise this routine will return true. */
632 static bool
634 {
637 /* [temp.expl.spec]
639 An explicit specialization shall be declared in the namespace of
640 which the template is a member, or, for member templates, in the
641 namespace of which the enclosing class or enclosing class
642 template is a member. An explicit specialization of a member
643 function, member class or static data member of a class template
644 shall be declared in the namespace of which the class template
645 is a member. */
647 {
650 }
652 /* [temp.expl.spec]
654 In an explicit specialization declaration for a member of a class
655 template or a member template that appears in namespace scope,
656 the member template and some of its enclosing class templates may
657 remain unspecialized, except that the declaration shall not
658 explicitly specialize a class member template if its enclosing
659 class templates are not explicitly specialized as well. */
661 {
664 }
667 }
669 /* We've just seen template <>. */
671 bool
673 {
677 }
679 /* Called at then end of processing a declaration preceded by
680 template<>. */
682 void
684 {
687 }
689 /* Any template <>'s that we have seen thus far are not referring to a
690 function specialization. */
692 void
694 {
697 }
699 /* We've just seen a template header. If SPECIALIZATION is nonzero,
700 it was of the form template <>. */
702 static void
704 {
706 template_header_count++;
707 }
709 /* We're beginning an explicit instantiation. */
711 void
713 {
716 }
719 void
721 {
724 }
726 /* An explicit specialization or partial specialization TMPL is being
727 declared. Check that the namespace in which the specialization is
728 occurring is permissible. Returns false iff it is invalid to
729 specialize TMPL in the current namespace. */
731 static bool
733 {
736 /* [tmpl.expl.spec]
738 An explicit specialization shall be declared in the namespace of
739 which the template is a member, or, for member templates, in the
740 namespace of which the enclosing class or enclosing class
741 template is a member. An explicit specialization of a member
742 function, member class or static data member of a class template
743 shall be declared in the namespace of which the class template is
744 a member. */
747 {
750 }
752 /* Same or super-using namespace. */
754 else
755 {
759 }
760 }
762 /* SPEC is an explicit instantiation. Check that it is valid to
763 perform this explicit instantiation in the current namespace. */
765 static void
767 {
768 tree ns;
770 /* DR 275: An explicit instantiation shall appear in an enclosing
771 namespace of its template. */
777 }
779 /* The TYPE is being declared. If it is a template type, that means it
780 is a partial specialization. Do appropriate error-checking. */
782 tree
784 {
785 tree context;
791 {
795 }
800 {
801 /* This is for ordinary explicit specialization and partial
802 specialization of a template class such as:
804 template <> class C<int>;
806 or:
808 template <class T> class C<T*>;
810 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
814 {
818 {
822 }
823 }
826 }
832 {
833 /* This is for an explicit specialization of member class
834 template according to [temp.expl.spec/18]:
836 template <> template <class U> class C<int>::D;
838 The context `C<int>' must be an implicit instantiation.
839 Otherwise this is just a member class template declared
840 earlier like:
842 template <> class C<int> { template <class U> class D; };
843 template <> template <class U> class C<int>::D;
845 In the first case, `C<int>::D' is a specialization of `C<T>::D'
846 while in the second case, `C<int>::D' is a primary template
847 and `C<T>::D' may not exist. */
851 {
852 tree t;
857 {
860 }
862 /* Check for invalid specialization after instantiation:
864 template <> template <> class C<int>::D<int>;
865 template <> template <class U> class C<int>::D; */
869 {
872 {
873 /* We already have a full specialization of this partial
874 instantiation. Reassign it to the new member
875 specialization template. */
876 spec_entry elt;
892 }
894 /* But if we've had an implicit instantiation, that's a
895 problem ([temp.expl.spec]/6). */
898 }
900 /* Mark TYPE as a specialization. And as a result, we only
901 have one level of template argument for the innermost
902 class template. */
906 }
907 }
909 {
912 }
915 }
917 /* Returns nonzero if we can optimize the retrieval of specializations
918 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
919 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
923 {
926 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
927 parameter. */
929 /* The optimized lookup depends on the fact that the
930 template arguments for the member function template apply
931 purely to the containing class, which is not true if the
932 containing class is an explicit or partial
933 specialization. */
937 /* It is possible to have a template that is not a member
938 template and is not a member of a template class:
940 template <typename T>
941 struct S { friend A::f(); };
943 Here, the friend function is a template, but the context does
944 not have template information. The optimized lookup relies
945 on having ARGS be the template arguments for both the class
946 and the function template. */
948 }
950 /* Retrieve the specialization (in the sense of [temp.spec] - a
951 specialization is either an instantiation or an explicit
952 specialization) of TMPL for the given template ARGS. If there is
953 no such specialization, return NULL_TREE. The ARGS are a vector of
954 arguments, or a vector of vectors of arguments, in the case of
955 templates with more than one level of parameters.
957 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
958 then we search for a partial specialization matching ARGS. This
959 parameter is ignored if TMPL is not a class template. */
961 static tree
963 {
969 /* There should be as many levels of arguments as there are
970 levels of parameters. */
975 {
976 tree class_template;
977 tree class_specialization;
979 tree fns;
982 /* The template arguments actually apply to the containing
983 class. Find the class specialization with those
984 arguments. */
986 class_specialization
990 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
991 for the specialization. */
995 /* Iterate through the methods with the indicated name, looking
996 for the one that has an instance of TMPL. */
999 {
1002 /* using-declarations can add base methods to the method vec,
1003 and we don't want those here. */
1006 }
1008 }
1009 else
1010 {
1012 spec_entry elt;
1013 htab_t specializations;
1021 else
1029 }
1032 }
1034 /* Like retrieve_specialization, but for local declarations. */
1036 static tree
1038 {
1039 tree spec;
1047 }
1049 /* Returns nonzero iff DECL is a specialization of TMPL. */
1051 int
1053 {
1054 tree t;
1057 {
1063 }
1064 else
1065 {
1074 }
1077 }
1079 /* Returns nonzero iff DECL is a specialization of friend declaration
1080 FRIEND_DECL according to [temp.friend]. */
1082 bool
1084 {
1091 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1092 of a template class, we want to check if DECL is a specialization
1093 if this. */
1097 {
1098 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1101 }
1106 /* There is nothing to do if this is not a template friend. */
1113 /* [temp.friend/6]
1114 A member of a class template may be declared to be a friend of a
1115 non-template class. In this case, the corresponding member of
1116 every specialization of the class template is a friend of the
1117 class granting friendship.
1119 For example, given a template friend declaration
1121 template <class T> friend void A<T>::f();
1123 the member function below is considered a friend
1125 template <> struct A<int> {
1126 void f();
1127 };
1129 For this type of template friend, TEMPLATE_DEPTH below will be
1130 nonzero. To determine if DECL is a friend of FRIEND, we first
1131 check if the enclosing class is a specialization of another. */
1138 {
1139 /* Next, we check the members themselves. In order to handle
1140 a few tricky cases, such as when FRIEND_DECL's are
1142 template <class T> friend void A<T>::g(T t);
1143 template <class T> template <T t> friend void A<T>::h();
1145 and DECL's are
1147 void A<int>::g(int);
1148 template <int> void A<int>::h();
1150 we need to figure out ARGS, the template arguments from
1151 the context of DECL. This is required for template substitution
1152 of `T' in the function parameter of `g' and template parameter
1153 of `h' in the above examples. Here ARGS corresponds to `int'. */
1160 {
1162 {
1165 else
1167 current_depth++;
1168 }
1170 }
1173 {
1175 tree friend_type;
1176 tree decl_type;
1177 tree friend_args_type;
1178 tree decl_args_type;
1180 /* Make sure that both DECL and FRIEND_DECL are templates or
1181 non-templates. */
1187 {
1188 /* If both are templates, check template parameter list. */
1189 tree friend_parms
1194 friend_parms))
1198 }
1199 else
1207 /* Check if return types match. */
1211 /* Check if function parameter types match, ignoring the
1212 `this' parameter. */
1221 }
1222 else
1223 {
1224 /* DECL is a TYPE_DECL */
1228 /* Make sure that both DECL and FRIEND_DECL are templates or
1229 non-templates. */
1230 is_template
1237 {
1238 tree friend_parms;
1239 /* If both are templates, check the name of the two
1240 TEMPLATE_DECL's first because is_friend didn't. */
1245 /* Now check template parameter list. */
1246 friend_parms
1249 return comp_template_parms
1251 friend_parms);
1252 }
1253 else
1256 }
1257 }
1259 }
1261 /* Register the specialization SPEC as a specialization of TMPL with
1262 the indicated ARGS. IS_FRIEND indicates whether the specialization
1263 is actually just a friend declaration. Returns SPEC, or an
1264 equivalent prior declaration, if available. */
1266 static tree
1268 hashval_t hash)
1269 {
1270 tree fn;
1272 spec_entry elt;
1278 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1279 register it; we want the corresponding TEMPLATE_DECL instead.
1280 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1281 the more obvious `uses_template_parms (spec)' to avoid problems
1282 with default function arguments. In particular, given
1283 something like this:
1285 template <class T> void f(T t1, T t = T())
1287 the default argument expression is not substituted for in an
1288 instantiation unless and until it is actually needed. */
1292 /* We don't put these specializations in the hash table, but we might
1293 want to give an error about a mismatch. */
1295 else
1296 {
1308 else
1310 }
1312 /* We can sometimes try to re-register a specialization that we've
1313 already got. In particular, regenerate_decl_from_template calls
1314 duplicate_decls which will update the specialization list. But,
1315 we'll still get called again here anyhow. It's more convenient
1316 to simply allow this than to try to prevent it. */
1320 {
1322 {
1325 {
1327 fn);
1329 }
1330 else
1331 {
1332 tree clone;
1333 /* This situation should occur only if the first
1334 specialization is an implicit instantiation, the
1335 second is an explicit specialization, and the
1336 implicit instantiation has not yet been used. That
1337 situation can occur if we have implicitly
1338 instantiated a member function and then specialized
1339 it later.
1341 We can also wind up here if a friend declaration that
1342 looked like an instantiation turns out to be a
1343 specialization:
1345 template <class T> void foo(T);
1346 class S { friend void foo<>(int) };
1347 template <> void foo(int);
1349 We transform the existing DECL in place so that any
1350 pointers to it become pointers to the updated
1351 declaration.
1353 If there was a definition for the template, but not
1354 for the specialization, we want this to look as if
1355 there were no definition, and vice versa. */
1358 /* The call to duplicate_decls will have applied
1359 [temp.expl.spec]:
1361 An explicit specialization of a function template
1362 is inline only if it is explicitly declared to be,
1363 and independently of whether its function template
1364 is.
1366 to the primary function; now copy the inline bits to
1367 the various clones. */
1369 {
1374 }
1378 }
1379 }
1381 {
1383 /* Dup decl failed, but this is a new definition. Set the
1384 line number so any errors match this new
1385 definition. */
1389 }
1390 }
1394 /* A specialization must be declared in the same namespace as the
1395 template it is specializing. */
1401 {
1408 /* TMPL is a forward declaration of a template function; keep a list
1409 of all specializations in case we need to reassign them to a friend
1410 template later in tsubst_friend_function. */
1413 }
1416 }
1418 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1419 TMPL and ARGS members, ignores SPEC. */
1421 static int
1423 {
1429 }
1431 /* Returns a hash for a template TMPL and template arguments ARGS. */
1433 static hashval_t
1435 {
1438 }
1440 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1441 ignoring SPEC. */
1443 static hashval_t
1445 {
1448 }
1450 /* Recursively calculate a hash value for a template argument ARG, for use
1451 in the hash tables of template specializations. */
1453 static hashval_t
1455 {
1467 /* We can get one of these when re-hashing a previous entry in the middle
1468 of substituting into a pack expansion. Just look through it. */
1477 {
1485 {
1490 }
1511 {
1514 {
1517 }
1519 }
1534 val = iterative_hash_template_arg
1546 val);
1548 val);
1557 /* layout_type sets structural equality for arrays of
1558 incomplete type, so we can't rely on the canonical type
1559 for hashing. */
1564 /* A lambda can't appear in a template arg, but don't crash on
1565 erroneous input. */
1576 /* Now hash operands as usual. */
1581 }
1584 {
1588 val);
1591 /* Otherwise just compare the types during lookup. */
1600 {
1605 }
1606 }
1609 }
1611 /* Unregister the specialization SPEC as a specialization of TMPL.
1612 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1613 if the SPEC was listed as a specialization of TMPL.
1615 Note that SPEC has been ggc_freed, so we can't look inside it. */
1617 bool
1619 {
1621 spec_entry elt;
1629 {
1634 }
1637 }
1639 /* Compare an entry in the local specializations hash table P1 (which
1640 is really a pointer to a TREE_LIST) with P2 (which is really a
1641 DECL). */
1643 static int
1645 {
1647 }
1649 /* Hash P1, an entry in the local specializations table. */
1651 static hashval_t
1653 {
1655 }
1657 /* Like register_specialization, but for local declarations. We are
1658 registering SPEC, an instantiation of TMPL. */
1660 static void
1662 {
1668 }
1670 /* TYPE is a class type. Returns true if TYPE is an explicitly
1671 specialized class. */
1673 bool
1675 {
1679 }
1681 /* Print the list of functions at FNS, going through all the overloads
1682 for each element of the list. Alternatively, FNS can not be a
1683 TREE_LIST, in which case it will be printed together with all the
1684 overloads.
1686 MORE and *STR should respectively be FALSE and NULL when the function
1687 is called from the outside. They are used internally on recursive
1688 calls. print_candidates manages the two parameters and leaves NULL
1689 in *STR when it ends. */
1691 static void
1693 {
1699 {
1704 }
1705 else
1706 {
1708 {
1709 /* Pick the prefix string. */
1711 {
1714 }
1718 }
1721 }
1724 {
1727 }
1728 }
1730 /* Print the list of candidate FNS in an error message. */
1732 void
1734 {
1738 }
1740 /* Returns the template (one of the functions given by TEMPLATE_ID)
1741 which can be specialized to match the indicated DECL with the
1742 explicit template args given in TEMPLATE_ID. The DECL may be
1743 NULL_TREE if none is available. In that case, the functions in
1744 TEMPLATE_ID are non-members.
1746 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1747 specialization of a member template.
1749 The TEMPLATE_COUNT is the number of references to qualifying
1750 template classes that appeared in the name of the function. See
1751 check_explicit_specialization for a more accurate description.
1753 TSK indicates what kind of template declaration (if any) is being
1754 declared. TSK_TEMPLATE indicates that the declaration given by
1755 DECL, though a FUNCTION_DECL, has template parameters, and is
1756 therefore a template function.
1758 The template args (those explicitly specified and those deduced)
1759 are output in a newly created vector *TARGS_OUT.
1761 If it is impossible to determine the result, an error message is
1762 issued. The error_mark_node is returned to indicate failure. */
1764 static tree
1766 tree decl,
1770 tmpl_spec_kind tsk)
1771 {
1772 tree fns;
1773 tree targs;
1774 tree explicit_targs;
1776 /* A TREE_LIST of templates of which DECL may be a specialization.
1777 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1778 corresponding TREE_PURPOSE is the set of template arguments that,
1779 when used to instantiate the template, would produce a function
1780 with the signature of DECL. */
1796 /* Check for baselinks. */
1801 {
1804 }
1806 /* Count the number of template headers specified for this
1807 specialization. */
1815 {
1819 {
1820 tree decl_arg_types;
1821 tree fn_arg_types;
1823 /* In case of explicit specialization, we need to check if
1824 the number of template headers appearing in the specialization
1825 is correct. This is usually done in check_explicit_specialization,
1826 but the check done there cannot be exhaustive when specializing
1827 member functions. Consider the following code:
1829 template <> void A<int>::f(int);
1830 template <> template <> void A<int>::f(int);
1832 Assuming that A<int> is not itself an explicit specialization
1833 already, the first line specializes "f" which is a non-template
1834 member function, whilst the second line specializes "f" which
1835 is a template member function. So both lines are syntactically
1836 correct, and check_explicit_specialization does not reject
1837 them.
1839 Here, we can do better, as we are matching the specialization
1840 against the declarations. We count the number of template
1841 headers, and we check if they match TEMPLATE_COUNT + 1
1842 (TEMPLATE_COUNT is the number of qualifying template classes,
1843 plus there must be another header for the member template
1844 itself).
1846 Notice that if header_count is zero, this is not a
1847 specialization but rather a template instantiation, so there
1848 is no check we can perform here. */
1852 /* Check that the number of template arguments at the
1853 innermost level for DECL is the same as for FN. */
1861 /* DECL might be a specialization of FN. */
1865 /* For a non-static member function, we need to make sure
1866 that the const qualification is the same. Since
1867 get_bindings does not try to merge the "this" parameter,
1868 we must do the comparison explicitly. */
1874 /* Skip the "this" parameter and, for constructors of
1875 classes with virtual bases, the VTT parameter. A
1876 full specialization of a constructor will have a VTT
1877 parameter, but a template never will. */
1878 decl_arg_types
1880 fn_arg_types
1883 /* Check that the number of function parameters matches.
1884 For example,
1885 template <class T> void f(int i = 0);
1886 template <> void f<int>();
1887 The specialization f<int> is invalid but is not caught
1888 by get_bindings below. */
1892 /* Function templates cannot be specializations; there are
1893 no partial specializations of functions. Therefore, if
1894 the type of DECL does not match FN, there is no
1895 match. */
1897 {
1901 }
1903 /* See whether this function might be a specialization of this
1904 template. */
1908 /* We cannot deduce template arguments that when used to
1909 specialize TMPL will produce DECL. */
1912 /* Save this template, and the arguments deduced. */
1914 }
1916 /* FN is an ordinary member function, and we need a
1917 specialization of a member template. */
1918 ;
1920 /* We can get IDENTIFIER_NODEs here in certain erroneous
1921 cases. */
1922 ;
1924 /* This is just an ordinary non-member function. Nothing can
1925 be a specialization of that. */
1926 ;
1928 /* Cannot specialize functions that are created implicitly. */
1929 ;
1930 else
1931 {
1932 tree decl_arg_types;
1934 /* This is an ordinary member function. However, since
1935 we're here, we can assume it's enclosing class is a
1936 template class. For example,
1938 template <typename T> struct S { void f(); };
1939 template <> void S<int>::f() {}
1941 Here, S<int>::f is a non-template, but S<int> is a
1942 template class. If FN has the same type as DECL, we
1943 might be in business. */
1946 /* Its enclosing class is an explicit specialization
1947 of a template class. This is not a candidate. */
1952 /* The return types differ. */
1955 /* Adjust the type of DECL in case FN is a static member. */
1962 decl_arg_types))
1963 /* They match! */
1965 }
1966 }
1969 {
1970 /* We have:
1972 [temp.expl.spec]
1974 It is possible for a specialization with a given function
1975 signature to be instantiated from more than one function
1976 template. In such cases, explicit specification of the
1977 template arguments must be used to uniquely identify the
1978 function template specialization being specialized.
1980 Note that here, there's no suggestion that we're supposed to
1981 determine which of the candidate templates is most
1982 specialized. However, we, also have:
1984 [temp.func.order]
1986 Partial ordering of overloaded function template
1987 declarations is used in the following contexts to select
1988 the function template to which a function template
1989 specialization refers:
1991 -- when an explicit specialization refers to a function
1992 template.
1994 So, we do use the partial ordering rules, at least for now.
1995 This extension can only serve to make invalid programs valid,
1996 so it's safe. And, there is strong anecdotal evidence that
1997 the committee intended the partial ordering rules to apply;
1998 the EDG front end has that behavior, and John Spicer claims
1999 that the committee simply forgot to delete the wording in
2000 [temp.expl.spec]. */
2003 {
2006 }
2007 }
2010 {
2018 }
2022 {
2028 }
2030 /* We have one, and exactly one, match. */
2032 {
2035 /* DECL is a re-declaration or partial instantiation of a template
2036 function. */
2039 /* It was a specialization of an ordinary member function in a
2040 template class. */
2042 }
2044 /* It was a specialization of a template. */
2047 {
2052 }
2053 else
2056 }
2058 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2059 but with the default argument values filled in from those in the
2060 TMPL_TYPES. */
2062 static tree
2064 tree tmpl_types)
2065 {
2066 tree new_spec_types;
2074 /* Substitute into the rest of the list. */
2075 new_spec_types =
2079 /* Add the default argument for this parameter. */
2082 new_spec_types);
2083 }
2085 /* DECL is an explicit specialization. Replicate default arguments
2086 from the template it specializes. (That way, code like:
2088 template <class T> void f(T = 3);
2089 template <> void f(double);
2090 void g () { f (); }
2092 works, as required.) An alternative approach would be to look up
2093 the correct default arguments at the call-site, but this approach
2094 is consistent with how implicit instantiations are handled. */
2096 static void
2098 {
2099 tree tmpl;
2100 tree spec_types;
2101 tree tmpl_types;
2102 tree new_spec_types;
2103 tree old_type;
2104 tree new_type;
2105 tree t;
2110 /* See if there's anything we need to do. */
2123 {
2124 /* Remove the this pointer, but remember the object's type for
2125 CV quals. */
2131 {
2132 /* DECL may contain more parameters than TMPL due to the extra
2133 in-charge parameter in constructors and destructors. */
2136 }
2138 {
2141 }
2142 }
2144 /* Compute the merged default arguments. */
2145 new_spec_types =
2148 /* Compute the new FUNCTION_TYPE. */
2150 {
2154 new_spec_types);
2157 /* Put the in-charge parameter back. */
2160 new_spec_types);
2164 new_spec_types);
2165 }
2166 else
2168 new_spec_types);
2174 }
2176 /* Check to see if the function just declared, as indicated in
2177 DECLARATOR, and in DECL, is a specialization of a function
2178 template. We may also discover that the declaration is an explicit
2179 instantiation at this point.
2181 Returns DECL, or an equivalent declaration that should be used
2182 instead if all goes well. Issues an error message if something is
2183 amiss. Returns error_mark_node if the error is not easily
2184 recoverable.
2186 FLAGS is a bitmask consisting of the following flags:
2188 2: The function has a definition.
2189 4: The function is a friend.
2191 The TEMPLATE_COUNT is the number of references to qualifying
2192 template classes that appeared in the name of the function. For
2193 example, in
2195 template <class T> struct S { void f(); };
2196 void S<int>::f();
2198 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2199 classes are not counted in the TEMPLATE_COUNT, so that in
2201 template <class T> struct S {};
2202 template <> struct S<int> { void f(); }
2203 template <> void S<int>::f();
2205 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2206 invalid; there should be no template <>.)
2208 If the function is a specialization, it is marked as such via
2209 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2210 is set up correctly, and it is added to the list of specializations
2211 for that template. */
2213 tree
2215 tree decl,
2218 {
2226 tmpl_spec_kind tsk;
2229 {
2232 else
2234 }
2235 else
2239 {
2242 {
2245 }
2247 {
2249 /* This could be something like:
2251 template <class T> void f(T);
2252 class S { friend void f<>(int); } */
2254 else
2255 {
2256 /* This case handles bogus declarations like template <>
2257 template <class T> void f<int>(); */
2260 declarator);
2262 }
2263 }
2267 /* The error has already been reported in
2268 check_specialization_scope. */
2274 /* Fall through. */
2287 decl);
2290 else
2294 /* Fall through. */
2299 else
2305 {
2306 /* This case handles bogus declarations like template <>
2307 template <class T> void f<int>(); */
2312 else
2314 declarator);
2316 }
2319 /* This is a specialization of a member template, without
2320 specialization the containing class. Something like:
2322 template <class T> struct S {
2323 template <class U> void f (U);
2324 };
2325 template <> template <class U> void S<int>::f(U) {}
2327 That's a specialization -- but of the entire template. */
2333 }
2336 {
2340 {
2344 }
2345 }
2348 {
2352 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2354 {
2355 tree fns;
2360 else
2361 {
2362 /* If there is no class context, the explicit instantiation
2363 must be at namespace scope. */
2366 /* Find the namespace binding, using the declaration
2367 context. */
2371 {
2374 }
2375 else
2376 {
2382 }
2383 }
2386 }
2392 {
2394 /* A specialization in class scope. This is invalid,
2395 but the error will already have been flagged by
2396 check_specialization_scope. */
2398 else
2399 {
2400 /* It's not valid to write an explicit instantiation in
2401 class scope, e.g.:
2403 class C { template void f(); }
2405 This case is caught by the parser. However, on
2406 something like:
2408 template class C { void f(); };
2410 (which is invalid) we can get here. The error will be
2411 issued later. */
2412 ;
2413 }
2416 }
2419 IDENTIFIER_NODE))
2420 {
2421 /* Find the list of functions in ctype that have the same
2422 name as the declared function. */
2428 {
2433 {
2434 /* From [temp.expl.spec]:
2436 If such an explicit specialization for the member
2437 of a class template names an implicitly-declared
2438 special member function (clause _special_), the
2439 program is ill-formed.
2441 Similar language is found in [temp.explicit]. */
2444 }
2447 }
2450 {
2454 }
2455 else
2456 {
2458 tree ovl;
2460 /* For a type-conversion operator, we cannot do a
2461 name-based lookup. We might be looking for `operator
2462 int' which will be a specialization of `operator T'.
2463 So, we find *all* the conversion operators, and then
2464 select from them. */
2472 {
2474 /* There are no more conversion functions. */
2477 /* Glue all these conversion functions together
2478 with those we already have. */
2481 }
2482 }
2485 {
2488 }
2489 else
2491 }
2493 /* Figure out what exactly is being specialized at this point.
2494 Note that for an explicit instantiation, even one for a
2495 member function, we cannot tell apriori whether the
2496 instantiation is for a member template, or just a member
2497 function of a template class. Even if a member template is
2498 being instantiated, the member template arguments may be
2499 elided if they can be deduced from the rest of the
2500 declaration. */
2503 member_specialization,
2504 template_count,
2505 tsk);
2508 /* We couldn't figure out what this declaration was
2509 specializing. */
2511 else
2512 {
2516 {
2517 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2518 is done by do_decl_instantiation later. */
2524 {
2525 /* If TMPL is not the most general template (for
2526 example, if TMPL is a friend template that is
2527 injected into namespace scope), then there will
2528 be too many levels of TARGS. Remove some of them
2529 here. */
2531 tree new_targs;
2538 }
2541 }
2543 /* If we thought that the DECL was a member function, but it
2544 turns out to be specializing a static member function,
2545 make DECL a static member function as well. */
2550 /* If this is a specialization of a member template of a
2551 template class, we want to return the TEMPLATE_DECL, not
2552 the specialization of it. */
2554 {
2559 {
2560 tree parm;
2564 /* We want to use the argument list specified in the
2565 definition, not in the original declaration. */
2570 }
2573 }
2575 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2578 /* Inherit default function arguments from the template
2579 DECL is specializing. */
2582 /* This specialization has the same protection as the
2583 template it specializes. */
2587 /* 7.1.1-1 [dcl.stc]
2589 A storage-class-specifier shall not be specified in an
2590 explicit specialization...
2592 The parser rejects these, so unless action is taken here,
2593 explicit function specializations will always appear with
2594 global linkage.
2596 The action recommended by the C++ CWG in response to C++
2597 defect report 605 is to make the storage class and linkage
2598 of the explicit specialization match the templated function:
2600 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2601 */
2603 {
2607 /* This specialization has the same linkage and visibility as
2608 the function template it specializes. */
2611 {
2614 }
2617 {
2620 }
2621 }
2623 /* If DECL is a friend declaration, declared using an
2624 unqualified name, the namespace associated with DECL may
2625 have been set incorrectly. For example, in:
2627 template <typename T> void f(T);
2628 namespace N {
2629 struct S { friend void f<int>(int); }
2630 }
2632 we will have set the DECL_CONTEXT for the friend
2633 declaration to N, rather than to the global namespace. */
2638 /* This is not really a declaration of a specialization.
2639 It's just the name of an instantiation. But, it's not
2640 a request for an instantiation, either. */
2643 /* This is indeed a specialization. In case of constructors
2644 and destructors, we need in-charge and not-in-charge
2645 versions in V3 ABI. */
2648 /* Register this specialization so that we can find it
2649 again. */
2651 }
2652 }
2655 }
2657 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2658 parameters. These are represented in the same format used for
2659 DECL_TEMPLATE_PARMS. */
2661 int
2663 {
2664 const_tree p1;
2665 const_tree p2;
2673 {
2685 {
2689 /* If either of the template parameters are invalid, assume
2690 they match for the sake of error recovery. */
2703 }
2704 }
2707 /* One set of parameters has more parameters lists than the
2708 other. */
2712 }
2714 /* Determine whether PARM is a parameter pack. */
2716 bool
2718 {
2719 /* Determine if we have a non-type template parameter pack. */
2724 /* If this is a list of template parameters, we could get a
2725 TYPE_DECL or a TEMPLATE_DECL. */
2732 }
2734 /* Determine if T is a function parameter pack. */
2736 bool
2738 {
2742 }
2744 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2745 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2747 tree
2749 {
2756 }
2758 /* Return true iff the function parameter PARAM_DECL was expanded
2759 from the function parameter pack PACK. */
2761 bool
2763 {
2768 /* The parameter pack and its pack arguments have the same
2769 DECL_PARM_INDEX. */
2771 }
2773 /* Determine whether ARGS describes a variadic template args list,
2774 i.e., one that is terminated by a template argument pack. */
2776 static bool
2778 {
2780 tree last_parm;
2794 }
2796 /* Generate a new name for the parameter pack name NAME (an
2797 IDENTIFIER_NODE) that incorporates its */
2799 static tree
2801 {
2802 /* Munge the name to include the parameter index. */
2803 #define NUMBUF_LEN 128
2815 }
2817 /* Return true if T is a primary function
2818 or class template instantiation. */
2820 bool
2822 {
2834 }
2836 /* Return true if PARM is a template template parameter. */
2838 bool
2840 {
2842 }
2844 /* Return the template parameters of T if T is a
2845 primary template instantiation, NULL otherwise. */
2847 tree
2849 {
2854 parms = INNERMOST_TEMPLATE_PARMS
2858 }
2860 /* Return the template parameters of the LEVELth level from the full list
2861 of template parameters PARMS. */
2863 tree
2865 {
2866 tree p;
2877 }
2879 /* Returns the template arguments of T if T is a template instantiation,
2880 NULL otherwise. */
2882 tree
2884 {
2892 }
2894 /* Return the argument pack elements of T if T is a template argument pack,
2895 NULL otherwise. */
2897 tree
2899 {
2905 }
2907 /* Structure used to track the progress of find_parameter_packs_r. */
2908 struct find_parameter_pack_data
2909 {
2910 /* TREE_LIST that will contain all of the parameter packs found by
2911 the traversal. */
2914 /* Set of AST nodes that have been visited by the traversal. */
2916 };
2918 /* Identifies all of the argument packs that occur in a template
2919 argument and appends them to the TREE_LIST inside DATA, which is a
2920 find_parameter_pack_data structure. This is a subroutine of
2921 make_pack_expansion and uses_parameter_packs. */
2922 static tree
2924 {
2930 /* Identify whether this is a parameter pack or not. */
2932 {
2946 {
2947 /* We don't want to walk into the type of a PARM_DECL,
2948 because we don't want to see the type parameter pack. */
2951 }
2955 /* Not a parameter pack. */
2957 }
2960 {
2961 /* Add this parameter pack to the list. */
2963 }
2969 /* This switch statement will return immediately if we don't find a
2970 parameter pack. */
2972 {
2977 /* Check the template itself. */
2980 /* Check the template arguments. */
2996 /* Fall through. */
3037 }
3040 }
3042 /* Determines if the expression or type T uses any parameter packs. */
3043 bool
3045 {
3053 }
3055 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3056 representation a base-class initializer into a parameter pack
3057 expansion. If all goes well, the resulting node will be an
3058 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3059 respectively. */
3060 tree
3062 {
3063 tree result;
3072 {
3073 /* The only time we will see a TREE_LIST here is for a base
3074 class initializer. In this case, the TREE_PURPOSE will be a
3075 _TYPE node (representing the base class expansion we're
3076 initializing) and the TREE_VALUE will be a TREE_LIST
3077 containing the initialization arguments.
3079 The resulting expansion looks somewhat different from most
3080 expansions. Rather than returning just one _EXPANSION, we
3081 return a TREE_LIST whose TREE_PURPOSE is a
3082 TYPE_PACK_EXPANSION containing the bases that will be
3083 initialized. The TREE_VALUE will be identical to the
3084 original TREE_VALUE, which is a list of arguments that will
3085 be passed to each base. We do not introduce any new pack
3086 expansion nodes into the TREE_VALUE (although it is possible
3087 that some already exist), because the TREE_PURPOSE and
3088 TREE_VALUE all need to be expanded together with the same
3089 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3090 resulting TREE_PURPOSE will mention the parameter packs in
3091 both the bases and the arguments to the bases. */
3092 tree purpose;
3093 tree value;
3096 /* Determine which parameter packs will be used by the base
3097 class expansion. */
3104 {
3108 }
3111 {
3112 /* Collect the sets of parameter packs used in each of the
3113 initialization arguments. */
3115 {
3116 /* Determine which parameter packs will be expanded in this
3117 argument. */
3120 }
3121 }
3125 /* Create the pack expansion type for the base type. */
3130 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3131 they will rarely be compared to anything. */
3135 }
3140 /* Build the PACK_EXPANSION_* node. */
3141 result = for_types
3146 {
3147 /* Propagate type and const-expression information. */
3150 }
3151 else
3152 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3153 they will rarely be compared to anything. */
3156 /* Determine which parameter packs will be expanded. */
3162 /* Make sure we found some parameter packs. */
3164 {
3167 else
3170 }
3174 }
3176 /* Checks T for any "bare" parameter packs, which have not yet been
3177 expanded, and issues an error if any are found. This operation can
3178 only be done on full expressions or types (e.g., an expression
3179 statement, "if" condition, etc.), because we could have expressions like:
3181 foo(f(g(h(args)))...)
3183 where "args" is a parameter pack. check_for_bare_parameter_packs
3184 should not be called for the subexpressions args, h(args),
3185 g(h(args)), or f(g(h(args))), because we would produce erroneous
3186 error messages.
3188 Returns TRUE and emits an error if there were bare parameter packs,
3189 returns FALSE otherwise. */
3190 bool
3192 {
3208 {
3211 {
3220 else
3225 else
3229 }
3232 }
3235 }
3237 /* Expand any parameter packs that occur in the template arguments in
3238 ARGS. */
3239 tree
3241 {
3247 /* First, determine if we need to expand anything, and the number of
3248 slots we'll need. */
3250 {
3255 {
3259 else
3261 }
3262 else
3263 {
3265 num_result_args++;
3266 }
3267 }
3269 /* If no expansion is necessary, we're done. */
3273 /* Expand arguments. */
3276 non_default_args_count =
3279 {
3282 {
3289 }
3290 else
3291 {
3294 }
3295 }
3299 }
3301 /* Checks if DECL shadows a template parameter.
3303 [temp.local]: A template-parameter shall not be redeclared within its
3304 scope (including nested scopes).
3306 Emits an error and returns TRUE if the DECL shadows a parameter,
3307 returns FALSE otherwise. */
3309 bool
3311 {
3312 tree olddecl;
3314 /* If we're not in a template, we can't possibly shadow a template
3315 parameter. */
3319 /* Figure out what we're shadowing. */
3324 /* If there's no previous binding for this name, we're not shadowing
3325 anything, let alone a template parameter. */
3329 /* If we're not shadowing a template parameter, we're done. Note
3330 that OLDDECL might be an OVERLOAD (or perhaps even an
3331 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3332 node. */
3336 /* We check for decl != olddecl to avoid bogus errors for using a
3337 name inside a class. We check TPFI to avoid duplicate errors for
3338 inline member templates. */
3346 }
3348 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3349 ORIG_LEVEL, DECL, and TYPE. */
3351 static tree
3355 tree decl,
3356 tree type)
3357 {
3368 }
3370 /* Find the canonical type parameter for the given template type
3371 parameter. Returns the canonical type parameter, which may be TYPE
3372 if no such parameter existed. */
3373 static tree
3375 {
3376 tree list;
3390 else
3391 {
3396 }
3397 }
3399 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3400 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3401 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3402 new one is created. */
3404 static tree
3406 tsubst_flags_t complain)
3407 {
3412 {
3431 /* Template template parameters need this. */
3436 }
3439 }
3441 /* Process information from new template parameter PARM and append it to the
3442 LIST being built. This new parameter is a non-type parameter iff
3443 IS_NON_TYPE is true. This new parameter is a parameter
3444 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3445 PARM_LOC. */
3447 tree
3450 {
3452 tree defval;
3453 tree err_parm_list;
3460 {
3464 {
3468 else
3470 }
3473 }
3474 else
3478 {
3484 {
3488 }
3489 else
3490 {
3491 /* [temp.param]
3493 The top-level cv-qualifiers on the template-parameter are
3494 ignored when determining its type. */
3497 {
3501 }
3504 {
3505 /* This template parameter is not a parameter pack, but it
3506 should be. Complain about "bare" parameter packs. */
3509 /* Recover by calling this a parameter pack. */
3511 }
3512 }
3514 /* A template parameter is not modifiable. */
3523 processing_template_decl,
3528 }
3529 else
3530 {
3531 tree t;
3535 {
3537 /* This is for distinguishing between real templates and template
3538 template parameters */
3542 }
3543 else
3544 {
3546 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3549 }
3556 processing_template_decl,
3560 }
3566 }
3568 /* The end of a template parameter list has been reached. Process the
3569 tree list into a parameter vector, converting each parameter into a more
3570 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3571 as PARM_DECLs. */
3573 tree
3575 {
3580 current_template_parms
3585 {
3591 current_template_parms;
3592 }
3597 }
3599 /* end_template_decl is called after a template declaration is seen. */
3601 void
3603 {
3609 /* This matches the pushlevel in begin_template_parm_list. */
3614 }
3616 /* Within the declaration of a template, return all levels of template
3617 parameters that apply. The template parameters are represented as
3618 a TREE_VEC, in the form documented in cp-tree.h for template
3619 arguments. */
3621 static tree
3623 {
3624 tree header;
3629 /* If there is only one level of template parameters, we do not
3630 create a TREE_VEC of TREE_VECs. Instead, we return a single
3631 TREE_VEC containing the arguments. */
3636 {
3642 {
3645 /* T will be a list if we are called from within a
3646 begin/end_template_parm_list pair, but a vector directly
3647 if within a begin/end_member_template_processing pair. */
3649 {
3653 {
3656 {
3660 {
3661 /* Turn this argument into a TYPE_ARGUMENT_PACK
3662 with a single element, which expands T. */
3664 #ifdef ENABLE_CHECKING
3665 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3667 #endif
3672 }
3673 }
3674 else
3675 {
3679 {
3680 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3681 with a single element, which expands T. */
3684 #ifdef ENABLE_CHECKING
3685 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3687 #endif
3693 }
3694 }
3696 }
3697 }
3698 }
3700 #ifdef ENABLE_CHECKING
3702 #endif
3706 else
3708 }
3711 }
3713 /* Update the declared TYPE by doing any lookups which were thought to be
3714 dependent, but are not now that we know the SCOPE of the declarator. */
3716 tree
3718 {
3729 /* Don't bother building up the args in this case. */
3731 {
3732 /* tsubst in the args corresponding to the template parameters,
3733 including auto if present. Most things will be unchanged, but
3734 make_typename_type and tsubst_qualified_id will resolve
3735 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3738 tree pushed;
3740 {
3744 }
3749 }
3755 {
3758 else
3760 }
3762 }
3764 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3765 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3766 a member template. Used by push_template_decl below. */
3768 static tree
3770 {
3777 }
3779 struct template_parm_data
3780 {
3781 /* The level of the template parameters we are currently
3782 processing. */
3785 /* The index of the specialization argument we are currently
3786 processing. */
3789 /* An array whose size is the number of template parameters. The
3790 elements are nonzero if the parameter has been used in any one
3791 of the arguments processed so far. */
3794 /* An array whose size is the number of template arguments. The
3795 elements are nonzero if the argument makes use of template
3796 parameters of this level. */
3798 };
3800 /* Subroutine of push_template_decl used to see if each template
3801 parameter in a partial specialization is used in the explicit
3802 argument list. If T is of the LEVEL given in DATA (which is
3803 treated as a template_parm_data*), then DATA->PARMS is marked
3804 appropriately. */
3806 static int
3808 {
3814 {
3817 }
3818 else
3819 {
3822 }
3825 {
3828 }
3830 /* Return zero so that for_each_template_parm will continue the
3831 traversal of the tree; we want to mark *every* template parm. */
3833 }
3835 /* Process the partial specialization DECL. */
3837 static tree
3839 {
3845 tree inner_parms;
3846 tree inst;
3859 /* We check that each of the template parameters given in the
3860 partial specialization is used in the argument list to the
3861 specialization. For example:
3863 template <class T> struct S;
3864 template <class T> struct S<T*>;
3866 The second declaration is OK because `T*' uses the template
3867 parameter T, whereas
3869 template <class T> struct S<int>;
3871 is no good. Even trickier is:
3873 template <class T>
3874 struct S1
3875 {
3876 template <class U>
3877 struct S2;
3878 template <class U>
3879 struct S2<T>;
3880 };
3882 The S2<T> declaration is actually invalid; it is a
3883 full-specialization. Of course,
3885 template <class U>
3886 struct S2<T (*)(U)>;
3888 or some such would have been OK. */
3896 {
3901 NULL,
3903 }
3906 {
3907 /* One of the template parms was not used in the
3908 specialization. */
3910 {
3913 }
3916 }
3921 /* [temp.class.spec]
3923 The argument list of the specialization shall not be identical to
3924 the implicit argument list of the primary template. */
3931 /* [temp.class.spec]
3933 A partially specialized non-type argument expression shall not
3934 involve template parameters of the partial specialization except
3935 when the argument expression is a simple identifier.
3937 The type of a template parameter corresponding to a specialized
3938 non-type argument shall not be dependent on a parameter of the
3939 specialization.
3941 Also, we verify that pack expansions only occur at the
3942 end of the argument list. */
3946 {
3953 {
3954 /* Extract the arguments from the argument pack. We'll be
3955 iterating over these in the following loop. */
3958 }
3961 {
3963 /* Get the Jth argument in the parameter pack. */
3967 {
3968 /* Pack expansions must come at the end of the
3969 argument list. */
3972 {
3976 else
3979 }
3980 }
3983 /* We only care about the pattern. */
3989 /* This next line is the `argument expression is not just a
3990 simple identifier' condition and also the `specialized
3991 non-type argument' bit. */
3993 {
3997 arg);
3998 else
3999 {
4000 /* Look at the corresponding template parameter,
4001 marking which template parameters its type depends
4002 upon. */
4006 {
4007 /* We haven't yet initialized TPD2. Do so now. */
4009 /* The number of parameters here is the number in the
4010 main template, which, as checked in the assertion
4011 above, is NARGS. */
4015 }
4017 /* Mark the template parameters. But this time, we're
4018 looking for the template parameters of the main
4019 template, not in the specialization. */
4026 NULL,
4030 {
4031 /* The type depended on some template parameters.
4032 If they are fully specialized in the
4033 specialization, that's OK. */
4042 "type %qT of template argument %qE depends "
4044 "type %qT of template argument %qE depends "
4046 type,
4047 arg);
4048 }
4049 }
4050 }
4051 }
4052 }
4054 /* We should only get here once. */
4064 {
4068 {
4072 "partial specialization of %qT after instantiation "
4074 }
4075 }
4078 }
4080 /* Check that a template declaration's use of default arguments and
4081 parameter packs is not invalid. Here, PARMS are the template
4082 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4083 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4084 specialization.
4087 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4088 declaration (but not a definition); 1 indicates a declaration, 2
4089 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4090 emitted for extraneous default arguments.
4092 Returns TRUE if there were no errors found, FALSE otherwise. */
4094 bool
4097 {
4100 tree parm_level;
4103 /* [temp.param]
4105 A default template-argument shall not be specified in a
4106 function template declaration or a function template definition, nor
4107 in the template-parameter-list of the definition of a member of a
4108 class template. */
4111 /* You can't have a function template declaration in a local
4112 scope, nor you can you define a member of a class template in a
4113 local scope. */
4120 /* If this is either a friend defined in the scope of the class
4121 or a member function. */
4127 /* And, if it was a member function, it really was defined in
4128 the scope of the class. */
4131 /* We already checked these parameters when the template was
4132 declared, so there's no need to do it again now. This function
4133 was defined in class scope, but we're processing it's body now
4134 that the class is complete. */
4137 /* Core issue 226 (C++0x only): the following only applies to class
4138 templates. */
4140 {
4141 /* [temp.param]
4143 If a template-parameter has a default template-argument, all
4144 subsequent template-parameters shall have a default
4145 template-argument supplied. */
4147 {
4154 {
4164 {
4166 /* For better subsequent error-recovery, we indicate that
4167 there should have been a default argument. */
4170 }
4172 && !is_partial
4173 && !is_friend_decl
4174 /* Don't complain about an enclosing partial
4175 specialization. */
4180 {
4181 /* A primary class template can only have one
4182 parameter pack, at the end of the template
4183 parameter list. */
4188 else
4196 }
4197 }
4198 }
4199 }
4202 || is_partial
4203 || !is_primary
4205 /* For an ordinary class template, default template arguments are
4206 allowed at the innermost level, e.g.:
4207 template <class T = int>
4208 struct S {};
4209 but, in a partial specialization, they're not allowed even
4210 there, as we have in [temp.class.spec]:
4212 The template parameter list of a specialization shall not
4213 contain default template argument values.
4215 So, for a partial specialization, or for a function template
4216 (in C++98/C++03), we look at all of them. */
4217 ;
4218 else
4219 /* But, for a primary class template that is not a partial
4220 specialization we look at all template parameters except the
4221 innermost ones. */
4224 /* Figure out what error message to issue. */
4237 else
4241 /* If we're inside a class definition, there's no need to
4242 examine the parameters to the class itself. On the one
4243 hand, they will be checked when the class is defined, and,
4244 on the other, default arguments are valid in things like:
4245 template <class T = double>
4246 struct S { template <class U> void f(U); };
4247 Here the default argument for `S' has no bearing on the
4248 declaration of `f'. */
4250 else
4251 /* Check everything. */
4257 {
4264 {
4269 {
4271 {
4278 }
4280 /* Clear out the default argument so that we are not
4281 confused later. */
4283 }
4284 }
4286 /* At this point, if we're still interested in issuing messages,
4287 they must apply to classes surrounding the object declared. */
4291 }
4294 }
4296 /* Worker for push_template_decl_real, called via
4297 for_each_template_parm. DATA is really an int, indicating the
4298 level of the parameters we are interested in. If T is a template
4299 parameter of that level, return nonzero. */
4301 static int
4303 {
4309 else
4312 }
4314 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4315 parameters given by current_template_args, or reuses a
4316 previously existing one, if appropriate. Returns the DECL, or an
4317 equivalent one, if it is replaced via a call to duplicate_decls.
4319 If IS_FRIEND is true, DECL is a friend declaration. */
4321 tree
4323 {
4324 tree tmpl;
4325 tree args;
4326 tree info;
4327 tree ctx;
4331 /* True if the template is a member template, in the sense of
4332 [temp.mem]. */
4338 /* See if this is a partial specialization. */
4347 /* For a friend, we want the context of the friend function, not
4348 the type of which it is a friend. */
4352 /* In the case of a virtual function, we want the class in which
4353 it is defined. */
4355 else
4356 /* Otherwise, if we're currently defining some class, the DECL
4357 is assumed to be a member of the class. */
4366 /* See if this is a primary template. */
4368 /* A friend template that specifies a class context, i.e.
4369 template <typename T> friend void A<T>::f();
4370 is not primary. */
4372 else
4376 {
4381 {
4384 }
4386 {
4388 {
4389 /* [temp.mem]
4391 A destructor shall not be a member template. */
4394 }
4401 {
4402 /* [basic.stc.dynamic.allocation]
4404 An allocation function can be a function
4405 template. ... Template allocation functions shall
4406 have two or more parameters. */
4409 }
4410 }
4414 else
4415 {
4418 }
4419 }
4421 /* Check to see that the rules regarding the use of default
4422 arguments are not being violated. */
4426 /* Ensure that there are no parameter packs in the type of this
4427 declaration that have not been expanded. */
4429 {
4430 /* Check each of the arguments individually to see if there are
4431 any bare parameter packs. */
4437 {
4440 {
4441 /* This is a PARM_DECL that contains unexpanded parameter
4442 packs. We have already complained about this in the
4443 check_for_bare_parameter_packs call, so just replace
4444 these types with ERROR_MARK_NODE. */
4447 }
4451 }
4453 /* Check for bare parameter packs in the return type and the
4454 exception specifiers. */
4456 /* Errors were already issued, set return type to int
4457 as the frontend doesn't expect error_mark_node as
4458 the return type. */
4462 }
4464 {
4467 }
4478 {
4483 /* If DECL is a TYPE_DECL for a class-template, then there won't
4484 be DECL_LANG_SPECIFIC. The information equivalent to
4485 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4489 {
4490 /* Since a template declaration already existed for this
4491 class-type, we must be redeclaring it here. Make sure
4492 that the redeclaration is valid. */
4494 current_template_parms);
4495 /* We don't need to create a new TEMPLATE_DECL; just use the
4496 one we already had. */
4498 }
4499 else
4500 {
4502 member_template_p);
4507 {
4508 /* A specialization of a member template of a template
4509 class. */
4513 }
4514 }
4515 }
4516 else
4517 {
4523 {
4526 }
4534 {
4535 tree new_tmpl;
4537 /* The declaration is a specialization of a member
4538 template, declared outside the class. Therefore, the
4539 innermost template arguments will be NULL, so we
4540 replace them with the arguments determined by the
4541 earlier call to check_explicit_specialization. */
4544 new_tmpl
4546 member_template_p);
4556 args,
4559 }
4561 /* Make sure the template headers we got make sense. */
4566 {
4569 }
4570 else
4572 {
4577 {
4581 else
4586 }
4591 /* Can happen in erroneous input. */
4593 else
4597 }
4599 /* Check that the parms are used in the appropriate qualifying scopes
4600 in the declarator. */
4604 {
4610 /* Avoid crash in import_export_decl. */
4613 }
4614 }
4619 /* Push template declarations for global functions and types. Note
4620 that we do not try to push a global template friend declared in a
4621 template class; such a thing may well depend on the template
4622 parameters of the class. */
4625 {
4630 /* Hide template friend classes that haven't been declared yet. */
4632 {
4635 }
4636 }
4639 {
4645 {
4648 /* It is a conversion operator. See if the type converted to
4649 depends on innermost template operands. */
4652 depth))
4654 }
4656 /* Give template template parms a DECL_CONTEXT of the template
4657 for which they are a parameter. */
4660 {
4664 }
4665 }
4667 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4668 back to its most general template. If TMPL is a specialization,
4669 ARGS may only have the innermost set of arguments. Add the missing
4670 argument levels if necessary. */
4682 }
4684 tree
4686 {
4688 }
4690 /* Called when a class template TYPE is redeclared with the indicated
4691 template PARMS, e.g.:
4693 template <class T> struct S;
4694 template <class T> struct S {}; */
4696 bool
4698 {
4699 tree tmpl;
4700 tree tmpl_parms;
4704 {
4707 }
4711 /* The type is nested in some template class. Nothing to worry
4712 about here; there are no new template parameters for the nested
4713 type. */
4717 {
4719 tmpl);
4721 }
4727 {
4737 }
4740 {
4741 tree tmpl_parm;
4742 tree parm;
4743 tree tmpl_default;
4744 tree parm_default;
4758 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4759 TEMPLATE_DECL. */
4769 {
4773 }
4776 {
4777 /* We have in [temp.param]:
4779 A template-parameter may not be given default arguments
4780 by two different declarations in the same scope. */
4785 }
4788 /* Update the previous template parameters (which are the ones
4789 that will really count) with the new default value. */
4792 /* Update the new parameters, too; they'll be used as the
4793 parameters for any members. */
4795 }
4798 }
4800 /* Simplify EXPR if it is a non-dependent expression. Returns the
4801 (possibly simplified) expression. */
4803 tree
4805 {
4809 /* If we're in a template, but EXPR isn't value dependent, simplify
4810 it. We're supposed to treat:
4812 template <typename T> void f(T[1 + 1]);
4813 template <typename T> void f(T[2]);
4815 as two declarations of the same function, for example. */
4819 {
4820 HOST_WIDE_INT saved_processing_template_decl;
4826 tf_error,
4831 }
4833 }
4835 /* EXPR is an expression which is used in a constant-expression context.
4836 For instance, it could be a VAR_DECL with a constant initializer.
4837 Extract the innermost constant expression.
4839 This is basically a more powerful version of
4840 integral_constant_value, which can be used also in templates where
4841 initializers can maintain a syntactic rather than semantic form
4842 (even if they are non-dependent, for access-checking purposes). */
4844 static tree
4846 {
4848 do
4849 {
4852 }
4856 }
4858 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4859 must be a function or a pointer-to-function type, as specified
4860 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4861 and check that the resulting function has external linkage. */
4863 static tree
4865 {
4879 /* [temp.arg.nontype]/1
4881 A template-argument for a non-type, non-template template-parameter
4882 shall be one of:
4883 [...]
4884 -- the address of an object or function with external linkage. */
4886 {
4891 }
4894 }
4896 /* Subroutine of convert_nontype_argument.
4897 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4898 Emit an error otherwise. */
4900 static bool
4902 {
4910 }
4912 /* Returns TRUE iff the address of OP is value-dependent.
4914 14.6.2.4 [temp.dep.temp]:
4915 A non-integral non-type template-argument is dependent if its type is
4916 dependent or it has either of the following forms
4917 qualified-id
4918 & qualified-id
4919 and contains a nested-name-specifier which specifies a class-name that
4920 names a dependent type.
4922 We generalize this to just say that the address of a member of a
4923 dependent class is value-dependent; the above doesn't cover the
4924 address of a static data member named with an unqualified-id. */
4926 static bool
4928 {
4929 /* We could use get_inner_reference here, but there's no need;
4930 this is only relevant for template non-type arguments, which
4931 can only be expressed as &id-expression. */
4933 {
4937 }
4940 }
4942 /* Attempt to convert the non-type template parameter EXPR to the
4943 indicated TYPE. If the conversion is successful, return the
4944 converted value. If the conversion is unsuccessful, return
4945 NULL_TREE if we issued an error message, or error_mark_node if we
4946 did not. We issue error messages for out-and-out bad template
4947 parameters, but not simply because the conversion failed, since we
4948 might be just trying to do argument deduction. Both TYPE and EXPR
4949 must be non-dependent.
4951 The conversion follows the special rules described in
4952 [temp.arg.nontype], and it is much more strict than an implicit
4953 conversion.
4955 This function is called twice for each template argument (see
4956 lookup_template_class for a more accurate description of this
4957 problem). This means that we need to handle expressions which
4958 are not valid in a C++ source, but can be created from the
4959 first call (for instance, casts to perform conversions). These
4960 hacks can go away after we fix the double coercion problem. */
4962 static tree
4964 {
4965 tree expr_type;
4967 /* Detect immediately string literals as invalid non-type argument.
4968 This special-case is not needed for correctness (we would easily
4969 catch this later), but only to provide better diagnostic for this
4970 common user mistake. As suggested by DR 100, we do not mention
4971 linkage issues in the diagnostic as this is not the point. */
4973 {
4978 }
4980 /* Add the ADDR_EXPR now for the benefit of
4981 value_dependent_expression_p. */
4985 /* If we are in a template, EXPR may be non-dependent, but still
4986 have a syntactic, rather than semantic, form. For example, EXPR
4987 might be a SCOPE_REF, rather than the VAR_DECL to which the
4988 SCOPE_REF refers. Preserving the qualifying scope is necessary
4989 so that access checking can be performed when the template is
4990 instantiated -- but here we need the resolved form so that we can
4991 convert the argument. */
4995 else
5002 else
5005 /* HACK: Due to double coercion, we can get a
5006 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5007 which is the tree that we built on the first call (see
5008 below when coercing to reference to object or to reference to
5009 function). We just strip everything and get to the arg.
5010 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5011 for examples. */
5013 {
5015 {
5016 /* ??? Maybe we could use convert_from_reference here, but we
5017 would need to relax its constraints because the NOP_EXPR
5018 could actually change the type to something more cv-qualified,
5019 and this is not folded by convert_from_reference. */
5030 }
5032 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5033 parameter is a pointer to object, through decay and
5034 qualification conversion. Let's strip everything. */
5036 {
5040 /* Skip the ADDR_EXPR only if it is part of the decay for
5041 an array. Otherwise, it is part of the original argument
5042 in the source code. */
5046 }
5047 }
5049 /* [temp.arg.nontype]/5, bullet 1
5051 For a non-type template-parameter of integral or enumeration type,
5052 integral promotions (_conv.prom_) and integral conversions
5053 (_conv.integral_) are applied. */
5055 {
5060 /* Notice that there are constant expressions like '4 % 0' which
5061 do not fold into integer constants. */
5063 {
5067 }
5069 /* At this point, an implicit conversion does what we want,
5070 because we already know that the expression is of integral
5071 type. */
5076 /* Conversion was allowed: fold it to a bare integer constant. */
5078 }
5079 /* [temp.arg.nontype]/5, bullet 2
5081 For a non-type template-parameter of type pointer to object,
5082 qualification conversions (_conv.qual_) and the array-to-pointer
5083 conversion (_conv.array_) are applied. */
5085 {
5086 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5088 A template-argument for a non-type, non-template template-parameter
5089 shall be one of: [...]
5091 -- the name of a non-type template-parameter;
5092 -- the address of an object or function with external linkage, [...]
5093 expressed as "& id-expression" where the & is optional if the name
5094 refers to a function or array, or if the corresponding
5095 template-parameter is a reference.
5097 Here, we do not care about functions, as they are invalid anyway
5098 for a parameter of type pointer-to-object. */
5101 /* Non-type template parameters are OK. */
5102 ;
5105 {
5107 {
5109 "because %qD is a variable, not the address of "
5113 }
5114 /* Other values, like integer constants, might be valid
5115 non-type arguments of some other type. */
5117 }
5118 else
5119 {
5120 tree decl;
5125 {
5130 }
5132 {
5137 }
5138 }
5147 }
5148 /* [temp.arg.nontype]/5, bullet 3
5150 For a non-type template-parameter of type reference to object, no
5151 conversions apply. The type referred to by the reference may be more
5152 cv-qualified than the (otherwise identical) type of the
5153 template-argument. The template-parameter is bound directly to the
5154 template-argument, which must be an lvalue. */
5156 {
5158 expr_type))
5162 {
5166 }
5169 {
5173 }
5175 /* [temp.arg.nontype]/1
5177 A template-argument for a non-type, non-template template-parameter
5178 shall be one of: [...]
5180 -- the address of an object or function with external linkage. */
5183 {
5186 {
5188 "because a reference variable does not have a constant "
5191 }
5192 }
5195 {
5200 }
5203 {
5208 }
5211 }
5212 /* [temp.arg.nontype]/5, bullet 4
5214 For a non-type template-parameter of type pointer to function, only
5215 the function-to-pointer conversion (_conv.func_) is applied. If the
5216 template-argument represents a set of overloaded functions (or a
5217 pointer to such), the matching function is selected from the set
5218 (_over.over_). */
5220 {
5221 /* If the argument is a template-id, we might not have enough
5222 context information to decay the pointer. */
5224 {
5228 }
5235 {
5239 }
5240 }
5241 /* [temp.arg.nontype]/5, bullet 5
5243 For a non-type template-parameter of type reference to function, no
5244 conversions apply. If the template-argument represents a set of
5245 overloaded functions, the matching function is selected from the set
5246 (_over.over_). */
5248 {
5250 {
5255 }
5262 }
5263 /* [temp.arg.nontype]/5, bullet 6
5265 For a non-type template-parameter of type pointer to member function,
5266 no conversions apply. If the template-argument represents a set of
5267 overloaded member functions, the matching member function is selected
5268 from the set (_over.over_). */
5270 {
5275 /* [temp.arg.nontype] bullet 1 says the pointer to member
5276 expression must be a pointer-to-member constant. */
5280 /* There is no way to disable standard conversions in
5281 resolve_address_of_overloaded_function (called by
5282 instantiate_type). It is possible that the call succeeded by
5283 converting &B::I to &D::I (where B is a base of D), so we need
5284 to reject this conversion here.
5286 Actually, even if there was a way to disable standard conversions,
5287 it would still be better to reject them here so that we can
5288 provide a superior diagnostic. */
5290 {
5294 /* If we are just one standard conversion off, explain. */
5299 }
5300 }
5301 /* [temp.arg.nontype]/5, bullet 7
5303 For a non-type template-parameter of type pointer to data member,
5304 qualification conversions (_conv.qual_) are applied. */
5306 {
5307 /* [temp.arg.nontype] bullet 1 says the pointer to member
5308 expression must be a pointer-to-member constant. */
5315 }
5316 /* A template non-type parameter must be one of the above. */
5317 else
5320 /* Sanity check: did we actually convert the argument to the
5321 right type? */
5324 }
5326 /* Subroutine of coerce_template_template_parms, which returns 1 if
5327 PARM_PARM and ARG_PARM match using the rule for the template
5328 parameters of template template parameters. Both PARM and ARG are
5329 template parameters; the rest of the arguments are the same as for
5330 coerce_template_template_parms.
5331 */
5332 static int
5334 tree arg,
5335 tsubst_flags_t complain,
5336 tree in_decl,
5337 tree outer_args)
5338 {
5347 {
5349 /* We encounter instantiations of templates like
5350 template <template <template <class> class> class TT>
5351 class C; */
5352 {
5359 }
5360 /* Fall through. */
5365 /* Argument is a parameter pack but parameter is not. */
5370 /* The tsubst call is used to handle cases such as
5372 template <int> class C {};
5373 template <class T, template <T> class TT> class D {};
5374 D<int, C> d;
5376 i.e. the parameter list of TT depends on earlier parameters. */
5378 && !same_type_p
5385 /* Argument is a parameter pack but parameter is not. */
5392 }
5395 }
5398 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5399 template template parameters. Both PARM_PARMS and ARG_PARMS are
5400 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5401 or PARM_DECL.
5403 Consider the example:
5404 template <class T> class A;
5405 template<template <class U> class TT> class B;
5407 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5408 the parameters to A, and OUTER_ARGS contains A. */
5410 static int
5412 tree arg_parms,
5413 tsubst_flags_t complain,
5414 tree in_decl,
5415 tree outer_args)
5416 {
5427 /* Determine whether we have a parameter pack at the end of the
5428 template template parameter's template parameter list. */
5430 {
5437 {
5451 }
5452 }
5458 /* Check all of the template parameters except the parameter pack at
5459 the end (if any). */
5461 {
5470 outer_args))
5473 }
5476 {
5477 /* Check each of the template parameters in the template
5478 argument against the template parameter pack at the end of
5479 the template template parameter. */
5486 {
5493 outer_args))
5495 }
5496 }
5499 }
5501 /* Verifies that the deduced template arguments (in TARGS) for the
5502 template template parameters (in TPARMS) represent valid bindings,
5503 by comparing the template parameter list of each template argument
5504 to the template parameter list of its corresponding template
5505 template parameter, in accordance with DR150. This
5506 routine can only be called after all template arguments have been
5507 deduced. It will return TRUE if all of the template template
5508 parameter bindings are okay, FALSE otherwise. */
5509 bool
5511 {
5515 /* We're dealing with template parms in this process. */
5521 {
5526 {
5531 {
5532 /* Look inside the argument pack. */
5535 }
5538 {
5542 /* Extract the next argument from the argument
5543 pack. */
5547 /* Look at the pattern of the pack expansion. */
5550 /* Extract the template parameters from the template
5551 argument. */
5557 /* Verify that we can coerce the template template
5558 parameters from the template argument to the template
5559 parameter. This requires an exact match. */
5561 && !coerce_template_template_parms
5563 targ_parms,
5564 tf_none,
5565 tparm,
5566 targs))
5567 {
5570 }
5571 }
5572 }
5573 }
5575 out:
5579 }
5581 /* Convert the indicated template ARG as necessary to match the
5582 indicated template PARM. Returns the converted ARG, or
5583 error_mark_node if the conversion was unsuccessful. Error and
5584 warning messages are issued under control of COMPLAIN. This
5585 conversion is for the Ith parameter in the parameter list. ARGS is
5586 the full set of template arguments deduced so far. */
5588 static tree
5590 tree arg,
5591 tree args,
5592 tsubst_flags_t complain,
5594 tree in_decl)
5595 {
5596 tree orig_arg;
5597 tree val;
5602 {
5603 /* The template argument was the name of some
5604 member function. That's usually
5605 invalid, but static members are OK. In any
5606 case, grab the underlying fields/functions
5607 and issue an error later if required. */
5610 }
5618 /* When determining whether an argument pack expansion is a template,
5619 look at the pattern. */
5623 /* Deal with an injected-class-name used as a template template arg. */
5625 {
5628 {
5636 }
5637 }
5639 is_tmpl_type =
5654 {
5660 typename_type,
5664 }
5666 {
5668 {
5670 {
5680 else
5682 }
5683 }
5685 }
5687 {
5689 {
5695 else
5697 }
5699 }
5702 {
5704 {
5706 /* The number of argument required is not known yet.
5707 Just accept it for now. */
5709 else
5710 {
5712 tree argparm;
5718 args))
5719 {
5722 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5723 TEMPLATE_DECL. */
5725 {
5730 }
5731 }
5732 else
5733 {
5735 {
5741 }
5744 }
5745 }
5746 }
5747 else
5749 /* We only form one instance of each template specialization.
5750 Therefore, if we use a non-canonical variant (i.e., a
5751 typedef), any future messages referring to the type will use
5752 the typedef, which is confusing if those future uses do not
5753 themselves also use the typedef. */
5756 }
5757 else
5758 {
5765 {
5768 else
5769 {
5770 /* Not sure if this is reachable, but it doesn't hurt
5771 to be robust. */
5774 }
5775 }
5777 /* We used to call digest_init here. However, digest_init
5778 will report errors, which we don't want when complain
5779 is zero. More importantly, digest_init will try too
5780 hard to convert things: for example, `0' should not be
5781 converted to pointer type at this point according to
5782 the standard. Accepting this is not merely an
5783 extension, since deciding whether or not these
5784 conversions can occur is part of determining which
5785 function template to call, or whether a given explicit
5786 argument specification is valid. */
5788 else
5797 {
5798 /* Strip typedefs from the SCOPE_REF. */
5803 }
5804 }
5807 }
5809 /* Coerces the remaining template arguments in INNER_ARGS (from
5810 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5811 Returns the coerced argument pack. PARM_IDX is the position of this
5812 parameter in the template parameter list. ARGS is the original
5813 template argument list. */
5814 static tree
5817 tree args,
5818 tree inner_args,
5820 tree new_args,
5822 tree in_decl,
5823 tsubst_flags_t complain)
5824 {
5827 tree packed_args;
5828 tree argument_pack;
5838 {
5839 /* When the template parameter is a non-type template
5840 parameter pack whose type uses parameter packs, we need
5841 to look at each of the template arguments
5842 separately. Build a vector of the types for these
5843 non-type template parameters in PACKED_TYPES. */
5844 tree expansion
5852 /* Check that we have the right number of arguments. */
5856 {
5857 int needed_parms
5862 }
5864 /* If we aren't able to check the actual arguments now
5865 (because they haven't been expanded yet), we can at least
5866 verify that all of the types used for the non-type
5867 template parameter pack are, in fact, valid for non-type
5868 template parameters. */
5871 {
5874 {
5878 }
5879 }
5880 }
5882 /* Convert the remaining arguments, which will be a part of the
5883 parameter pack "parm". */
5885 {
5890 {
5891 /* When we have a vector of types (corresponding to the
5892 non-type template parameter pack that uses parameter
5893 packs in its type, as mention above), and the
5894 argument is not an expansion (which expands to a
5895 currently unknown number of arguments), clone the
5896 parm and give it the next type in PACKED_TYPES. */
5900 }
5905 in_decl);
5909 }
5914 else
5915 {
5920 }
5923 #ifdef ENABLE_CHECKING
5926 #endif
5928 }
5930 /* Convert all template arguments to their appropriate types, and
5931 return a vector containing the innermost resulting template
5932 arguments. If any error occurs, return error_mark_node. Error and
5933 warning messages are issued under control of COMPLAIN.
5935 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5936 for arguments not specified in ARGS. Otherwise, if
5937 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5938 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5939 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5940 ARGS. */
5942 static tree
5944 tree args,
5945 tree in_decl,
5946 tsubst_flags_t complain,
5949 {
5951 tree inner_args;
5952 tree new_args;
5953 tree new_inner_args;
5957 /* When used as a boolean value, indicates whether this is a
5958 variadic template parameter list. Since it's an int, we can also
5959 subtract it from nparms to get the number of non-variadic
5960 parameters. */
5965 /* Determine if there are any parameter packs. */
5967 {
5971 }
5974 /* If there are 0 or 1 parameter packs, we need to expand any argument
5975 packs so that we can deduce a parameter pack from some non-packed args
5976 followed by an argument pack, as in variadic85.C. If there are more
5977 than that, we need to leave argument packs intact so the arguments are
5978 assigned to the right parameter packs. This should only happen when
5979 dealing with a nested class inside a partial specialization of a class
5980 template, as in variadic92.C. */
5987 && require_all_args
5988 && (!use_default_args
5991 {
5993 {
5995 {
5999 }
6000 else
6006 }
6009 }
6011 /* We need to evaluate the template arguments, even though this
6012 template-id may be nested within a "sizeof". */
6020 {
6021 tree arg;
6022 tree parm;
6024 /* Get the Ith template parameter. */
6028 {
6031 }
6033 /* Calculate the next argument. */
6036 else
6041 {
6042 /* All remaining arguments will be placed in the
6043 template parameter pack PARM. */
6049 /* Store this argument. */
6051 lost++;
6054 /* We are done with all of the arguments. */
6058 }
6060 {
6062 {
6064 {
6065 /* FIXME this restriction was removed by N2555; see
6066 bug 35722. */
6067 /* If ARG is a pack expansion, but PARM is not a
6068 template parameter pack (if it were, we would have
6069 handled it above), we're trying to expand into a
6070 fixed-length argument list. */
6074 else
6077 }
6079 }
6080 }
6082 {
6083 /* There must be a default arg in this case. */
6086 /* The position of the first default template argument,
6087 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6088 Record that. */
6091 }
6092 else
6096 {
6099 }
6101 /* This only occurs if there was an error in the template
6102 parameter list itself (which we would already have
6103 reported) that we are trying to recover from, e.g., a class
6104 template with a parameter list such as
6105 template<typename..., typename>. */
6107 else
6113 lost++;
6115 }
6122 #ifdef ENABLE_CHECKING
6126 #endif
6129 }
6131 /* Returns 1 if template args OT and NT are equivalent. */
6133 static int
6135 {
6140 /* For member templates */
6147 {
6164 }
6166 {
6167 /* We get here probably because we are in the middle of substituting
6168 into the pattern of a pack expansion. In that case the
6169 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6170 interested in. So we want to use the initial pack argument for
6171 the comparison. */
6176 }
6181 else
6183 }
6185 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6186 of template arguments. Returns 0 otherwise. */
6188 int
6190 {
6197 {
6203 }
6205 }
6207 static void
6209 {
6219 /* We are called both from instantiate_decl, where we've already had a
6220 tinst_level pushed, and instantiate_template, where we haven't.
6221 Compensate. */
6232 else
6241 }
6244 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6245 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6246 documentation for TEMPLATE_ID_EXPR. */
6248 tree
6250 {
6251 tree type;
6261 {
6263 unknown_type_node,
6265 arglist);
6267 }
6274 }
6276 /* Within the scope of a template class S<T>, the name S gets bound
6277 (in build_self_reference) to a TYPE_DECL for the class, not a
6278 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6279 or one of its enclosing classes, and that type is a template,
6280 return the associated TEMPLATE_DECL. Otherwise, the original
6281 DECL is returned.
6283 Also handle the case when DECL is a TREE_LIST of ambiguous
6284 injected-class-names from different bases. */
6286 tree
6288 {
6292 /* DR 176: A lookup that finds an injected-class-name (10.2
6293 [class.member.lookup]) can result in an ambiguity in certain cases
6294 (for example, if it is found in more than one base class). If all of
6295 the injected-class-names that are found refer to specializations of
6296 the same class template, and if the name is followed by a
6297 template-argument-list, the reference refers to the class template
6298 itself and not a specialization thereof, and is not ambiguous. */
6300 {
6303 {
6309 }
6312 else
6314 }
6320 }
6322 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6323 parameters, find the desired type.
6325 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6327 IN_DECL, if non-NULL, is the template declaration we are trying to
6328 instantiate.
6330 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6331 the class we are looking up.
6333 Issue error and warning messages under control of COMPLAIN.
6335 If the template class is really a local class in a template
6336 function, then the FUNCTION_CONTEXT is the function in which it is
6337 being instantiated.
6339 ??? Note that this function is currently called *twice* for each
6340 template-id: the first time from the parser, while creating the
6341 incomplete type (finish_template_type), and the second type during the
6342 real instantiation (instantiate_template_class). This is surely something
6343 that we want to avoid. It also causes some problems with argument
6344 coercion (see convert_nontype_argument for more information on this). */
6346 tree
6348 tree arglist,
6349 tree in_decl,
6350 tree context,
6352 tsubst_flags_t complain)
6353 {
6355 tree t;
6358 spec_entry elt;
6359 hashval_t hash;
6364 {
6368 else
6369 {
6376 }
6379 }
6381 {
6384 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6385 an implicit typename for the second A. Deal with it. */
6390 {
6393 }
6394 }
6397 {
6400 }
6404 {
6408 }
6410 /* Issue an error message if we didn't find a template. */
6412 {
6416 }
6419 /* Make sure it's a user visible template, if it was named by
6420 the user. */
6423 {
6425 {
6429 }
6431 }
6436 {
6437 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6438 template arguments */
6440 tree parm;
6441 tree arglist2;
6442 tree outer;
6446 /* Consider an example where a template template parameter declared as
6448 template <class T, class U = std::allocator<T> > class TT
6450 The template parameter level of T and U are one level larger than
6451 of TT. To proper process the default argument of U, say when an
6452 instantiation `TT<int>' is seen, we need to build the full
6453 arguments containing {int} as the innermost level. Outer levels,
6454 available when not appearing as default template argument, can be
6455 obtained from the arguments of the enclosing template.
6457 Suppose that TT is later substituted with std::vector. The above
6458 instantiation is `TT<int, std::allocator<T> >' with TT at
6459 level 1, and T at level 2, while the template arguments at level 1
6460 becomes {std::vector} and the inner level 2 is {int}. */
6466 /* This is an argument of the current template, so we haven't set
6467 DECL_CONTEXT yet. */
6474 complain,
6484 }
6485 else
6486 {
6488 tree gen_tmpl;
6489 tree type_decl;
6502 {
6503 /* We've been given an incomplete set of template arguments.
6504 For example, given:
6506 template <class T> struct S1 {
6507 template <class U> struct S2 {};
6508 template <class U> struct S2<U*> {};
6509 };
6511 we will be called with an ARGLIST of `U*', but the
6512 TEMPLATE will be `template <class T> template
6513 <class U> struct S1<T>::S2'. We must fill in the missing
6514 arguments. */
6515 arglist
6517 arglist);
6519 }
6521 /* Now we should have enough arguments. */
6524 /* From here on, we're only interested in the most general
6525 template. */
6527 /* Calculate the BOUND_ARGS. These will be the args that are
6528 actually tsubst'd into the definition to create the
6529 instantiation. */
6531 {
6532 /* We have multiple levels of arguments to coerce, at once. */
6542 {
6545 complain,
6549 /* Don't process further if one of the levels fails. */
6551 {
6552 /* Restore the ARGLIST to its full size. */
6555 }
6559 /* We temporarily reduce the length of the ARGLIST so
6560 that coerce_template_parms will see only the arguments
6561 corresponding to the template parameters it is
6562 examining. */
6564 }
6566 /* Restore the ARGLIST to its full size. */
6570 }
6571 else
6572 arglist
6575 gen_tmpl,
6576 complain,
6581 /* We were unable to bind the arguments. */
6584 /* In the scope of a template class, explicit references to the
6585 template class refer to the type of the template, not any
6586 instantiation of it. For example, in:
6588 template <class T> class C { void f(C<T>); }
6590 the `C<T>' is just the same as `C'. Outside of the
6591 class, however, such a reference is an instantiation. */
6595 /* comp_template_args is expensive, check it last. */
6597 arglist))
6600 /* If we already have this specialization, return it. */
6612 /* If the deduced arguments are invalid, then the binding
6613 failed. */
6617 complain))
6624 {
6629 }
6636 /* Create the type. */
6638 {
6640 {
6646 }
6647 else
6648 {
6649 /* We don't want to call start_enum for this type, since
6650 the values for the enumeration constants may involve
6651 template parameters. And, no one should be interested
6652 in the enumeration constants for such a type. */
6655 }
6656 }
6657 else
6658 {
6665 /* A local class. Make sure the decl gets registered properly. */
6670 /* This instantiation is another name for the primary
6671 template type. Set the TYPE_CANONICAL field
6672 appropriately. */
6675 /* Some of the template arguments require structural
6676 equality testing, so this template class requires
6677 structural equality testing. */
6679 }
6681 /* If we called start_enum or pushtag above, this information
6682 will already be set up. */
6684 {
6691 }
6692 else
6700 {
6703 }
6705 /* Let's consider the explicit specialization of a member
6706 of a class template specialization that is implicitely instantiated,
6707 e.g.:
6708 template<class T>
6709 struct S
6710 {
6711 template<class U> struct M {}; //#0
6712 };
6714 template<>
6715 template<>
6716 struct S<int>::M<char> //#1
6717 {
6718 int i;
6719 };
6720 [temp.expl.spec]/4 says this is valid.
6722 In this case, when we write:
6723 S<int>::M<char> m;
6725 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6726 the one of #0.
6728 When we encounter #1, we want to store the partial instantiation
6729 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6731 For all cases other than this "explicit specialization of member of a
6732 class template", we just want to store the most general template into
6733 the CLASSTYPE_TI_TEMPLATE of M.
6735 This case of "explicit specialization of member of a class template"
6736 only happens when:
6737 1/ the enclosing class is an instantiation of, and therefore not
6738 the same as, the context of the most general template, and
6739 2/ we aren't looking at the partial instantiation itself, i.e.
6740 the innermost arguments are not the same as the innermost parms of
6741 the most general template.
6743 So it's only when 1/ and 2/ happens that we want to use the partial
6744 instantiation of the member template in lieu of its most general
6745 template. */
6749 /* the enclosing class must be an instantiation... */
6752 {
6753 tree partial_inst_args;
6756 partial_inst_args =
6762 use_partial_inst_tmpl =
6763 /*...and we must not be looking at the partial instantiation
6764 itself. */
6766 partial_inst_args);
6767 }
6770 /* This case is easy; there are no member templates involved. */
6772 else
6773 {
6774 /* This is a full instantiation of a member template. Find
6775 the partial instantiation of which this is an instance. */
6777 /* Temporarily reduce by one the number of levels in the ARGLIST
6778 so as to avoid comparing the last set of arguments. */
6783 }
6793 /* Note this use of the partial instantiation so we can check it
6794 later in maybe_process_partial_specialization. */
6800 /* Now that the type has been registered on the instantiations
6801 list, we set up the enumerators. Because the enumeration
6802 constants may involve the enumeration type itself, we make
6803 sure to register the type first, and then create the
6804 constants. That way, doing tsubst_expr for the enumeration
6805 constants won't result in recursive calls here; we'll find
6806 the instantiation and exit above. */
6810 /* If the type makes use of template parameters, the
6811 code that generates debugging information will crash. */
6814 /* Possibly limit visibility based on template args. */
6819 }
6821 }
6822 \f
6823 struct pair_fn_data
6824 {
6825 tree_fn_t fn;
6827 /* True when we should also visit template parameters that occur in
6828 non-deduced contexts. */
6831 };
6833 /* Called from for_each_template_parm via walk_tree. */
6835 static tree
6837 {
6850 {
6854 /* Fall through. */
6877 /* Since we're not going to walk subtrees, we have to do this
6878 explicitly here. */
6882 /* Fall through. */
6885 /* Check the return type. */
6890 /* Check the parameter types. Since default arguments are not
6891 instantiated until they are needed, the TYPE_ARG_TYPES may
6892 contain expressions that involve template parameters. But,
6893 no-one should be looking at them yet. And, once they're
6894 instantiated, they don't contain template parameters, so
6895 there's no point in looking at them then, either. */
6896 {
6897 tree parm;
6904 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6905 want walk_tree walking into them itself. */
6907 }
6924 /* Fall through. */
6940 /* Record template parameters such as `T' inside `TT<T>'. */
6944 /* Fall through. */
6956 /* A template template parameter is encountered. */
6962 /* Already substituted template template parameter */
6985 /* If there's no type, then this thing must be some expression
6986 involving template parameters. */
7007 }
7009 /* We didn't find any template parameters we liked. */
7011 }
7013 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7014 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7015 call FN with the parameter and the DATA.
7016 If FN returns nonzero, the iteration is terminated, and
7017 for_each_template_parm returns 1. Otherwise, the iteration
7018 continues. If FN never returns a nonzero value, the value
7019 returned by for_each_template_parm is 0. If FN is NULL, it is
7020 considered to be the function which always returns 1.
7022 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7023 parameters that occur in non-deduced contexts. When false, only
7024 visits those template parameters that can be deduced. */
7026 static int
7030 {
7034 /* Set up. */
7039 /* Walk the tree. (Conceptually, we would like to walk without
7040 duplicates, but for_each_template_parm_r recursively calls
7041 for_each_template_parm, so we would need to reorganize a fair
7042 bit to use walk_tree_without_duplicates, so we keep our own
7043 visited list.) */
7046 else
7049 for_each_template_parm_r,
7053 /* Clean up. */
7055 {
7058 }
7061 }
7063 /* Returns true if T depends on any template parameter. */
7065 int
7067 {
7094 else
7095 {
7098 }
7103 }
7105 /* Returns true if T depends on any template parameter with level LEVEL. */
7107 int
7109 {
7112 }
7116 #ifdef GATHER_STATISTICS
7118 #endif
7122 /* We're starting to instantiate D; record the template instantiation context
7123 for diagnostics and to restore it later. */
7125 int
7127 {
7131 {
7132 /* If the instantiation in question still has unbound template parms,
7133 we don't really care if we can't instantiate it, so just return.
7134 This happens with base instantiation for implicit `typename'. */
7146 }
7156 #ifdef GATHER_STATISTICS
7159 #endif
7163 }
7165 /* We're done instantiating this template; return to the instantiation
7166 context. */
7168 void
7170 {
7171 /* Restore the filename and line number stashed away when we started
7172 this instantiation. */
7177 }
7179 /* We're instantiating a deferred template; restore the template
7180 instantiation context in which the instantiation was requested, which
7181 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7183 static tree
7185 {
7195 }
7197 /* Returns the TINST_LEVEL which gives the original instantiation
7198 context. */
7202 {
7208 }
7210 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7212 bool
7214 {
7215 tree parms;
7232 }
7234 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7235 vector of template arguments, as for tsubst.
7237 Returns an appropriate tsubst'd friend declaration. */
7239 static tree
7241 {
7242 tree new_friend;
7247 /* This was a friend declared with an explicit template
7248 argument list, e.g.:
7250 friend void f<>(T);
7252 to indicate that f was a template instantiation, not a new
7253 function declaration. Now, we have to figure out what
7254 instantiation of what template. */
7255 {
7257 tree new_args;
7258 tree tmpl;
7261 /* Friend functions are looked up in the containing namespace scope.
7262 We must enter that scope, to avoid finding member functions of the
7263 current class with same name. */
7278 tsk_none);
7280 }
7284 /* The NEW_FRIEND will look like an instantiation, to the
7285 compiler, but is not an instantiation from the point of view of
7286 the language. For example, we might have had:
7288 template <class T> struct S {
7289 template <class U> friend void f(T, U);
7290 };
7292 Then, in S<int>, template <class U> void f(int, U) is not an
7293 instantiation of anything. */
7299 {
7303 }
7305 /* The mangled name for the NEW_FRIEND is incorrect. The function
7306 is not a template instantiation and should not be mangled like
7307 one. Therefore, we forget the mangling here; we'll recompute it
7308 later if we need it. */
7310 {
7313 }
7316 {
7317 tree old_decl;
7318 tree new_friend_template_info;
7319 tree new_friend_result_template_info;
7320 tree ns;
7323 /* We must save some information from NEW_FRIEND before calling
7324 duplicate decls since that function will free NEW_FRIEND if
7325 possible. */
7327 new_friend_is_defn =
7332 {
7333 /* This declaration is a `primary' template. */
7336 new_friend_result_template_info
7338 }
7339 else
7342 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7346 /* Inside pushdecl_namespace_level, we will push into the
7347 current namespace. However, the friend function should go
7348 into the namespace of the template. */
7358 {
7359 /* This new friend declaration matched an existing
7360 declaration. For example, given:
7362 template <class T> void f(T);
7363 template <class U> class C {
7364 template <class T> friend void f(T) {}
7365 };
7367 the friend declaration actually provides the definition
7368 of `f', once C has been instantiated for some type. So,
7369 old_decl will be the out-of-class template declaration,
7370 while new_friend is the in-class definition.
7372 But, if `f' was called before this point, the
7373 instantiation of `f' will have DECL_TI_ARGS corresponding
7374 to `T' but not to `U', references to which might appear
7375 in the definition of `f'. Previously, the most general
7376 template for an instantiation of `f' was the out-of-class
7377 version; now it is the in-class version. Therefore, we
7378 run through all specialization of `f', adding to their
7379 DECL_TI_ARGS appropriately. In particular, they need a
7380 new set of outer arguments, corresponding to the
7381 arguments for this class instantiation.
7383 The same situation can arise with something like this:
7385 friend void f(int);
7386 template <class T> class C {
7387 friend void f(T) {}
7388 };
7390 when `C<int>' is instantiated. Now, `f(int)' is defined
7391 in the class. */
7394 /* On the other hand, if the in-class declaration does
7395 *not* provide a definition, then we don't want to alter
7396 existing definitions. We can just leave everything
7397 alone. */
7398 ;
7399 else
7400 {
7404 /* Overwrite whatever template info was there before, if
7405 any, with the new template information pertaining to
7406 the declaration. */
7410 {
7411 /* We should have called reregister_specialization in
7412 duplicate_decls. */
7417 /* Instantiate it if the global has already been used. */
7421 }
7422 else
7423 {
7424 tree t;
7426 /* Indicate that the old function template is a partial
7427 instantiation. */
7435 /* Reassign any specializations already in the hash table
7436 to the new more general template, and add the
7437 additional template args. */
7441 {
7443 spec_entry elt;
7455 register_specialization
7458 }
7460 }
7461 }
7463 /* The information from NEW_FRIEND has been merged into OLD_DECL
7464 by duplicate_decls. */
7466 }
7467 }
7468 else
7469 {
7473 /* In the code
7474 template <class T> class C {
7475 template <class U> friend void C1<U>::f (); // case 1
7476 friend void C2<T>::f (); // case 2
7477 };
7478 we only need to make sure CONTEXT is a complete type for
7479 case 2. To distinguish between the two cases, we note that
7480 CONTEXT of case 1 remains dependent type after tsubst while
7481 this isn't true for case 2. */
7491 {
7492 /* Check to see that the declaration is really present, and,
7493 possibly obtain an improved declaration. */
7499 }
7500 }
7503 }
7505 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7506 template arguments, as for tsubst.
7508 Returns an appropriate tsubst'd friend type or error_mark_node on
7509 failure. */
7511 static tree
7513 {
7514 tree friend_type;
7515 tree tmpl;
7516 tree context;
7521 {
7524 else
7526 }
7528 /* Look for a class template declaration. We look for hidden names
7529 because two friend declarations of the same template are the
7530 same. For example, in:
7532 struct A {
7533 template <typename> friend class F;
7534 };
7535 template <typename> struct B {
7536 template <typename> friend class F;
7537 };
7539 both F templates are the same. */
7544 /* But, if we don't find one, it might be because we're in a
7545 situation like this:
7547 template <class T>
7548 struct S {
7549 template <class U>
7550 friend struct S;
7551 };
7553 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7554 for `S<int>', not the TEMPLATE_DECL. */
7556 {
7559 }
7562 {
7563 /* The friend template has already been declared. Just
7564 check to see that the declarations match, and install any new
7565 default parameters. We must tsubst the default parameters,
7566 of course. We only need the innermost template parameters
7567 because that is all that redeclare_class_template will look
7568 at. */
7571 {
7572 tree parms;
7573 location_t saved_input_location;
7582 }
7585 }
7586 else
7587 {
7588 /* The friend template has not already been declared. In this
7589 case, the instantiation of the template class will cause the
7590 injection of this template into the global scope. */
7595 /* The new TMPL is not an instantiation of anything, so we
7596 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7597 the new type because that is supposed to be the corresponding
7598 template decl, i.e., TMPL. */
7605 /* Inject this template into the global scope. */
7607 }
7610 {
7613 else
7615 }
7618 }
7620 /* Returns zero if TYPE cannot be completed later due to circularity.
7621 Otherwise returns one. */
7623 static int
7625 {
7635 else
7637 }
7639 /* Apply any attributes which had to be deferred until instantiation
7640 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7641 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7643 static void
7646 {
7648 tree t;
7653 {
7657 }
7660 {
7664 }
7665 else
7669 {
7674 {
7677 {
7680 /* If the first attribute argument is an identifier, don't
7681 pass it through tsubst. Attributes like mode, format,
7682 cleanup and several target specific attributes expect it
7683 unmodified. */
7689 {
7690 tree chain
7692 in_decl,
7697 chain);
7698 }
7699 else
7705 }
7706 else
7708 }
7711 }
7712 }
7714 /* Perform (or defer) access check for typedefs that were referenced
7715 from within the template TMPL code.
7716 This is a subroutine of instantiate_template and instantiate_class_template.
7717 TMPL is the template to consider and TARGS is the list of arguments of
7718 that template. */
7720 static void
7722 {
7723 location_t saved_location;
7738 {
7750 /* Make access check error messages point to the location
7751 of the use of the typedef. */
7755 }
7757 }
7759 tree
7761 {
7763 tree typedecl;
7764 tree pbinfo;
7765 tree base_list;
7775 /* Figure out which template is being instantiated. */
7779 /* Determine what specialization of the original template to
7780 instantiate. */
7783 {
7786 }
7788 {
7789 /* This TYPE is actually an instantiation of a partial
7790 specialization. We replace the innermost set of ARGS with
7791 the arguments appropriate for substitution. For example,
7792 given:
7794 template <class T> struct S {};
7795 template <class T> struct S<T*> {};
7797 and supposing that we are instantiating S<int*>, ARGS will
7798 presently be {int*} -- but we need {int}. */
7801 }
7802 else
7803 {
7806 }
7808 /* If the template we're instantiating is incomplete, then clearly
7809 there's nothing we can do. */
7813 /* If we've recursively instantiated too many templates, stop. */
7817 /* Now we're really doing the instantiation. Mark the type as in
7818 the process of being defined. */
7821 /* We may be in the middle of deferred access check. Disable
7822 it now. */
7826 /* Use #pragma pack from the template context. */
7832 /* Set the input location to the most specialized template definition.
7833 This is needed if tsubsting causes an error. */
7855 {
7858 }
7862 /* We should never instantiate a nested class before its enclosing
7863 class; we need to look up the nested class by name before we can
7864 instantiate it, and that lookup should instantiate the enclosing
7865 class. */
7871 {
7872 tree pbase_binfo;
7874 tree pushed_scope;
7877 /* We must enter the scope containing the type, as that is where
7878 the accessibility of types named in dependent bases are
7879 looked up from. */
7882 /* Substitute into each of the bases to determine the actual
7883 basetypes. */
7885 {
7886 tree base;
7892 {
7893 expanded_bases =
7900 }
7903 {
7905 /* Extract the already-expanded base class. */
7907 else
7908 /* Substitute to figure out the base class. */
7910 NULL_TREE);
7918 }
7919 }
7921 /* The list is now in reverse order; correct that. */
7926 }
7927 /* Now call xref_basetypes to set up all the base-class
7928 information. */
7935 /* Now that our base classes are set up, enter the scope of the
7936 class, so that name lookups into base classes, etc. will work
7937 correctly. This is precisely analogous to what we do in
7938 begin_class_definition when defining an ordinary non-template
7939 class, except we also need to push the enclosing classes. */
7942 /* Now members are processed in the order of declaration. */
7945 {
7949 {
7951 {
7952 /* Build new CLASSTYPE_NESTED_UTDS. */
7954 tree newtag;
7960 /* If the member is a class template, then -- even after
7961 substitution -- there may be dependent types in the
7962 template argument list for the class. We increment
7963 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7964 that function will assume that no types are dependent
7965 when outside of a template. */
7975 {
7979 /* Unfortunately, lookup_template_class sets
7980 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7981 instantiation (i.e., for the type of a member
7982 template class nested within a template class.)
7983 This behavior is required for
7984 maybe_process_partial_specialization to work
7985 correctly, but is not accurate in this case;
7986 the TAG is not an instantiation of anything.
7987 (The corresponding TEMPLATE_DECL is an
7988 instantiation, but the TYPE is not.) */
7991 /* Now, we call pushtag to put this NEWTAG into the scope of
7992 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7993 pushtag calling push_template_decl. We don't have to do
7994 this for enums because it will already have been done in
7995 tsubst_enum. */
7999 }
8000 }
8003 {
8004 /* Build new TYPE_METHODS. */
8005 tree r;
8014 }
8015 else
8016 {
8017 /* Build new TYPE_FIELDS. */
8019 {
8020 tree condition =
8028 }
8030 {
8031 tree r;
8033 /* The file and line for this declaration, to
8034 assist in error message reporting. Since we
8035 called push_tinst_level above, we don't need to
8036 restore these. */
8045 {
8046 /* In [temp.inst]:
8048 [t]he initialization (and any associated
8049 side-effects) of a static data member does
8050 not occur unless the static data member is
8051 itself used in a way that requires the
8052 definition of the static data member to
8053 exist.
8055 Therefore, we do not substitute into the
8056 initialized for the static data member here. */
8057 finish_static_data_member_decl
8065 }
8067 {
8068 /* Determine whether R has a valid type and can be
8069 completed later. If R is invalid, then it is
8070 replaced by error_mark_node so that it will not be
8071 added to TYPE_FIELDS. */
8077 {
8080 }
8081 }
8083 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8084 such a thing will already have been added to the field
8085 list by tsubst_enum in finish_member_declaration in the
8086 CLASSTYPE_NESTED_UTDS case above. */
8090 {
8093 }
8094 }
8095 }
8096 }
8097 else
8098 {
8100 {
8101 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8107 {
8108 /* template <class T> friend class C; */
8111 }
8113 {
8114 /* template <class T> friend class C::D; */
8120 }
8122 {
8123 /* This could be either
8125 friend class T::C;
8127 when dependent_type_p is false or
8129 template <class U> friend class T::C;
8131 otherwise. */
8134 /* Bump processing_template_decl for correct
8135 dependent_type_p calculation. */
8140 }
8143 {
8144 /* friend class C;
8146 where C hasn't been declared yet. Let's lookup name
8147 from namespace scope directly, bypassing any name that
8148 come from dependent base class. */
8151 /* The call to xref_tag_from_type does injection for friend
8152 classes. */
8154 friend_type =
8158 }
8160 /* friend class C<T>; */
8163 /* Otherwise it's
8165 friend class C;
8167 where C is already declared or
8169 friend class C<int>;
8171 We don't have to do anything in these cases. */
8174 /* Trick make_friend_class into realizing that the friend
8175 we're adding is a template, not an ordinary class. It's
8176 important that we use make_friend_class since it will
8177 perform some error-checking and output cross-reference
8178 information. */
8186 }
8187 else
8188 {
8189 /* Build new DECL_FRIENDLIST. */
8190 tree r;
8192 /* The file and line for this declaration, to
8193 assist in error message reporting. Since we
8194 called push_tinst_level above, we don't need to
8195 restore these. */
8199 {
8202 }
8207 {
8210 }
8211 }
8212 }
8213 }
8215 /* Set the file and line number information to whatever is given for
8216 the class itself. This puts error messages involving generated
8217 implicit functions at a predictable point, and the same point
8218 that would be used for non-template classes. */
8225 /* Now that the class is complete, instantiate default arguments for
8226 any member functions. We don't do this earlier because the
8227 default arguments may reference members of the class. */
8231 /* Implicitly generated member functions will not have template
8232 information; they are not instantiations, but instead are
8233 created "fresh" for each instantiation. */
8237 /* Some typedefs referenced from within the template code need to be access
8238 checked at template instantiation time, i.e now. These types were
8239 added to the template at parsing time. Let's get those and perform
8240 the access checks then. */
8249 /* The vtable for a template class can be emitted in any translation
8250 unit in which the class is instantiated. When there is no key
8251 method, however, finish_struct_1 will already have added TYPE to
8252 the keyed_classes list. */
8257 }
8259 static tree
8261 {
8262 tree r;
8268 else
8269 {
8273 }
8275 }
8277 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8278 NONTYPE_ARGUMENT_PACK. */
8280 static tree
8282 {
8283 /* Collect all of the extra "packed" parameters into an
8284 argument pack. */
8285 tree parmvec;
8286 tree parmtypevec;
8291 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8295 {
8298 }
8300 /* Build the argument packs. */
8306 }
8308 /* Substitute ARGS into T, which is an pack expansion
8309 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8310 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8311 (if only a partial substitution could be performed) or
8312 ERROR_MARK_NODE if there was an error. */
8313 tree
8315 tree in_decl)
8316 {
8317 tree pattern;
8320 tree result;
8327 /* Determine the argument packs that will instantiate the parameter
8328 packs used in the expansion expression. While we're at it,
8329 compute the number of arguments to be expanded and make sure it
8330 is consistent. */
8333 {
8339 {
8342 else
8343 {
8344 /* We can't rely on local_specializations for a parameter
8345 name used later in a function declaration (such as in a
8346 late-specified return type). Even if it exists, it might
8347 have the wrong value for a recursive call. Just make a
8348 dummy decl, since it's only used for its type. */
8351 }
8352 }
8353 else
8354 {
8361 }
8368 /* This can only happen if we forget to expand an argument
8369 pack somewhere else. Just return an error, silently. */
8370 {
8374 }
8379 {
8384 /* The argument pack that the parameter maps to is just an
8385 expansion of the parameter itself, such as one would
8386 find in the implicit typedef of a class inside the
8387 class itself. Consider this parameter "unsubstituted",
8388 so that we will maintain the outer pack expansion. */
8390 }
8393 {
8397 /* It's all-or-nothing with incomplete argument packs. */
8407 {
8409 /* We got explicit args for some packs but not others;
8410 do nothing now and try again after deduction. */
8415 pattern);
8416 else
8419 pattern);
8421 }
8423 /* Keep track of the parameter packs and their corresponding
8424 argument packs. */
8427 }
8428 else
8429 /* We can't substitute for this parameter pack. */
8432 unsubstituted_packs);
8433 }
8435 /* We cannot expand this expansion expression, because we don't have
8436 all of the argument packs we need. Substitute into the pattern
8437 and return a PACK_EXPANSION_*. The caller will need to deal with
8438 that. */
8440 {
8441 tree new_pat;
8445 else
8448 }
8450 /* We could not find any argument packs that work. */
8455 {
8456 /* We're in a late-specified return type, so create our own local
8457 specializations table; the current table is either NULL or (in the
8458 case of recursive unification) might have bindings that we don't
8459 want to use or alter. */
8462 hash_local_specialization,
8463 eq_local_specializations,
8464 NULL);
8465 }
8467 /* For each argument in each argument pack, substitute into the
8468 pattern. */
8471 {
8472 /* For parameter pack, change the substitution of the parameter
8473 pack to the ith argument in its argument pack, then expand
8474 the pattern. */
8476 {
8480 {
8481 /* Select the Ith argument from the pack. */
8487 }
8488 else
8489 {
8495 {
8496 /* Select the Ith argument from the pack. */
8500 }
8502 /* Update the corresponding argument. */
8504 }
8505 }
8507 /* Substitute into the PATTERN with the altered arguments. */
8512 else
8516 /* When we have incomplete argument packs, the last "expanded"
8517 result is itself a pack expansion, which allows us
8518 to deduce more arguments. */
8523 {
8526 }
8527 }
8529 /* Update ARGS to restore the substitution from parameter packs to
8530 their argument packs. */
8532 {
8537 else
8538 {
8542 /* Update the corresponding argument. */
8546 else
8548 }
8549 }
8552 {
8555 }
8558 }
8560 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8561 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8562 parameter packs; all parms generated from a function parameter pack will
8563 have the same DECL_PARM_INDEX. */
8565 tree
8567 {
8569 tree patparm;
8572 {
8578 }
8579 else
8580 {
8585 }
8588 }
8590 /* Substitute ARGS into the vector or list of template arguments T. */
8592 static tree
8594 {
8601 {
8603 tree new_arg;
8608 {
8609 /* Substitute into an expansion expression. */
8613 /* Add to the expanded length adjustment the number of
8614 expanded arguments. We subtract one from this
8615 measurement, because the argument pack expression
8616 itself is already counted as 1 in
8617 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8618 the argument pack is empty. */
8620 }
8622 {
8623 /* Substitute into each of the arguments. */
8629 new_arg,
8643 }
8644 }
8645 else
8654 }
8659 /* Make space for the expanded arguments coming from template
8660 argument packs. */
8662 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8663 arguments for a member template.
8664 In that case each TREE_VEC in ORIG_T represents a level of template
8665 arguments, and ORIG_T won't carry any non defaulted argument count.
8666 It will rather be the nested TREE_VECs that will carry one.
8667 In other words, ORIG_T carries a non defaulted argument count only
8668 if it doesn't contain any nested TREE_VEC. */
8670 {
8674 }
8676 {
8680 {
8683 /* Now expand the template argument pack "in place". */
8686 }
8687 else
8688 {
8690 out++;
8691 }
8692 }
8695 }
8697 /* Return the result of substituting ARGS into the template parameters
8698 given by PARMS. If there are m levels of ARGS and m + n levels of
8699 PARMS, then the result will contain n levels of PARMS. For
8700 example, if PARMS is `template <class T> template <class U>
8701 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8702 result will be `template <int*, double, class V>'. */
8704 static tree
8706 {
8710 /* When substituting into a template, we must set
8711 PROCESSING_TEMPLATE_DECL as the template parameters may be
8712 dependent if they are based on one-another, and the dependency
8713 predicates are short-circuit outside of templates. */
8720 {
8721 tree new_vec =
8726 {
8727 tree tuple;
8728 tree default_value;
8729 tree parm_decl;
8751 }
8757 }
8762 }
8764 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8765 type T. If T is not an aggregate or enumeration type, it is
8766 handled as if by tsubst. IN_DECL is as for tsubst. If
8767 ENTERING_SCOPE is nonzero, T is the context for a template which
8768 we are presently tsubst'ing. Return the substituted value. */
8770 static tree
8772 tree args,
8773 tsubst_flags_t complain,
8774 tree in_decl,
8776 {
8781 {
8786 /* Else fall through. */
8790 {
8791 tree argvec;
8792 tree context;
8793 tree r;
8797 /* In "sizeof(X<I>)" we need to evaluate "I". */
8803 /* First, determine the context for the type we are looking
8804 up. */
8807 {
8810 /* If context is a nested class inside a class template,
8811 it may still need to be instantiated (c++/33959). */
8814 }
8816 /* Then, figure out what arguments are appropriate for the
8817 type we are trying to find. For example, given:
8819 template <class T> struct S;
8820 template <class T, class U> void f(T, U) { S<U> su; }
8822 and supposing that we are instantiating f<int, double>,
8823 then our ARGS will be {int, double}, but, when looking up
8824 S we only want {double}. */
8829 else
8830 {
8834 }
8840 }
8841 else
8842 /* This is not a template type, so there's nothing to do. */
8847 }
8848 }
8850 /* Substitute into the default argument ARG (a default argument for
8851 FN), which has the indicated TYPE. */
8853 tree
8855 {
8859 /* This default argument came from a template. Instantiate the
8860 default argument here, not in tsubst. In the case of
8861 something like:
8863 template <class T>
8864 struct S {
8865 static T t();
8866 void f(T = t());
8867 };
8869 we must be careful to do name lookup in the scope of S<T>,
8870 rather than in the current class. */
8872 /* The "this" pointer is not valid in a default argument. */
8874 {
8879 }
8882 /* The default argument expression may cause implicitly defined
8883 member functions to be synthesized, which will result in garbage
8884 collection. We must treat this situation as if we were within
8885 the body of function so as to avoid collecting live data on the
8886 stack. */
8894 /* Restore the "this" pointer. */
8896 {
8899 }
8901 /* Make sure the default argument is reasonable. */
8907 }
8909 /* Substitute into all the default arguments for FN. */
8911 static void
8913 {
8914 tree arg;
8915 tree tmpl_args;
8919 /* If this function is not yet instantiated, we certainly don't need
8920 its default arguments. */
8925 arg;
8931 }
8933 /* Substitute the ARGS into the T, which is a _DECL. Return the
8934 result of the substitution. Issue error and warning messages under
8935 control of COMPLAIN. */
8937 static tree
8939 {
8940 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8941 location_t saved_loc;
8946 /* Set the filename and linenumber to improve error-reporting. */
8951 {
8953 {
8954 /* We can get here when processing a member function template,
8955 member class template, or template template parameter. */
8957 tree spec;
8958 tree tmpl_args;
8959 tree full_args;
8962 {
8963 /* Template template parameter is treated here. */
8976 complain);
8979 }
8981 /* We might already have an instance of this template.
8982 The ARGS are for the surrounding class type, so the
8983 full args contain the tsubst'd args for the context,
8984 plus the innermost args from the template decl. */
8988 /* Because this is a template, the arguments will still be
8989 dependent, even after substitution. If
8990 PROCESSING_TEMPLATE_DECL is not set, the dependency
8991 predicates will short-circuit. */
8999 /* If this is a default template template argument,
9000 tsubst might not have changed anything. */
9007 {
9010 }
9012 /* Make a new template decl. It will be similar to the
9013 original, but will record the current template arguments.
9014 We also create a new function declaration, which is just
9015 like the old one, but points to this new template, rather
9016 than the old one. */
9024 {
9025 tree new_type;
9037 }
9038 else
9039 {
9040 tree new_decl;
9052 }
9058 /* The template parameters for this new template are all the
9059 template parameters for the old template, except the
9060 outermost level of parameters. */
9063 complain);
9069 /* Record this non-type partial instantiation. */
9073 }
9077 {
9078 tree ctx;
9081 tree gen_tmpl;
9082 tree type;
9087 /* Nobody should be tsubst'ing into non-template functions. */
9091 {
9092 tree spec;
9095 /* If T is not dependent, just return it. We have to
9096 increment PROCESSING_TEMPLATE_DECL because
9097 value_dependent_expression_p assumes that nothing is
9098 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9105 /* Calculate the most general template of which R is a
9106 specialization, and the complete set of arguments used to
9107 specialize R. */
9110 (DECL_TEMPLATE_RESULT
9114 /* Check to see if we already have this specialization. */
9119 {
9122 }
9124 /* We can see more levels of arguments than parameters if
9125 there was a specialization of a member template, like
9126 this:
9128 template <class T> struct S { template <class U> void f(); }
9129 template <> template <class U> void S<int>::f(U);
9131 Here, we'll be substituting into the specialization,
9132 because that's where we can find the code we actually
9133 want to generate, but we'll have enough arguments for
9134 the most general template.
9136 We also deal with the peculiar case:
9138 template <class T> struct S {
9139 template <class U> friend void f();
9140 };
9141 template <class U> void f() {}
9142 template S<int>;
9143 template void f<double>();
9145 Here, the ARGS for the instantiation of will be {int,
9146 double}. But, we only need as many ARGS as there are
9147 levels of template parameters in CODE_PATTERN. We are
9148 careful not to get fooled into reducing the ARGS in
9149 situations like:
9151 template <class T> struct S { template <class U> void f(U); }
9152 template <class T> template <> void S<T>::f(int) {}
9154 which we can spot because the pattern will be a
9155 specialization in this case. */
9157 parms_depth =
9162 }
9163 else
9164 {
9165 /* This special case arises when we have something like this:
9167 template <class T> struct S {
9168 friend void f<int>(int, double);
9169 };
9171 Here, the DECL_TI_TEMPLATE for the friend declaration
9172 will be an IDENTIFIER_NODE. We are being called from
9173 tsubst_friend_function, and we want only to create a
9174 new decl (R) with appropriate types so that we can call
9175 determine_specialization. */
9177 }
9180 {
9183 else
9187 }
9188 else
9189 {
9192 }
9197 /* We do NOT check for matching decls pushed separately at this
9198 point, as they may not represent instantiations of this
9199 template, and in any case are considered separate under the
9200 discrete model. */
9204 /* Clear out the mangled name and RTL for the instantiation. */
9207 /* Leave DECL_INITIAL set on deleted instantiations. */
9213 /* Type-conversion operator. Reconstruct the name, in
9214 case it's the name of one of the template's parameters. */
9224 /* If this is an instantiation of a function with internal
9225 linkage, we already know what object file linkage will be
9226 assigned to the instantiation. */
9235 /* We'll re-clone as appropriate in instantiate_template. */
9238 /* If we aren't complaining now, return on error before we register
9239 the specialization so that we'll complain eventually. */
9245 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9246 this in the special friend case mentioned above where
9247 GEN_TMPL is NULL. */
9249 {
9255 /* We're not supposed to instantiate default arguments
9256 until they are called, for a template. But, for a
9257 declaration like:
9259 template <class T> void f ()
9260 { extern void g(int i = T()); }
9262 we should do the substitution when the template is
9263 instantiated. We handle the member function case in
9264 instantiate_class_template since the default arguments
9265 might refer to other members of the class. */
9270 }
9271 else
9274 /* Copy the list of befriending classes. */
9278 {
9282 in_decl);
9283 }
9286 {
9290 /* If this is an instantiation of a member template, clone it.
9291 If it isn't, that'll be handled by
9292 clone_constructors_and_destructors. */
9295 }
9306 /* Possibly limit visibility based on template args. */
9309 {
9313 }
9321 }
9325 {
9333 {
9334 /* If there is a local specialization that isn't a
9335 parameter pack, it means that we're doing a "simple"
9336 substitution from inside tsubst_pack_expansion. Just
9337 return the local specialization (which will be a single
9338 parm). */
9345 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9346 the parameters in this function parameter pack. */
9350 {
9353 /* Zero-length parameter packs are boring. Just substitute
9354 into the chain. */
9358 }
9359 else
9360 {
9361 /* All we did was update the type. Make a note of that. */
9364 }
9365 }
9367 /* Loop through all of the parameter's we'll build. When T is
9368 a function parameter pack, LEN is the number of expanded
9369 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9372 {
9378 /* An argument of a function parameter pack is not a parameter
9379 pack. */
9383 /* We're on the Ith parameter of the function parameter
9384 pack. */
9385 {
9386 /* Get the Ith type. */
9390 /* Rename the parameter to include the index. */
9393 }
9395 /* We're dealing with a normal parameter. */
9403 {
9406 else
9409 }
9419 /* Keep track of the first new parameter we
9420 generate. That's what will be returned to the
9421 caller. */
9425 /* Build a proper chain of parameters when substituting
9426 into a function parameter pack. */
9429 }
9435 /* FIRST_R contains the start of the chain we've built. */
9437 }
9441 {
9442 tree type;
9451 /* DECL_INITIAL gives the number of bits in a bit-field. */
9456 /* We don't have to set DECL_CONTEXT here; it is set by
9457 finish_member_declaration. */
9464 }
9468 /* We reach here only for member using decls. */
9470 {
9471 r = do_class_using_decl
9476 else
9477 {
9480 }
9481 }
9482 else
9483 {
9486 }
9491 {
9494 tree spec;
9496 tree ctx;
9502 {
9503 /* If this is the canonical decl, we don't have to
9504 mess with instantiations, and often we can't (for
9505 typename, template type parms and such). Note that
9506 TYPE_NAME is not correct for the above test if
9507 we've copied the type for a typedef. */
9513 }
9515 /* Check to see if we already have the specialization we
9516 need. */
9519 {
9520 /* T is a static data member or namespace-scope entity.
9521 We have to substitute into namespace-scope variables
9522 (even though such entities are never templates) because
9523 of cases like:
9525 template <class T> void f() { extern T t; }
9527 where the entity referenced is not known until
9528 instantiation time. */
9532 {
9534 complain,
9536 /* If CTX is unchanged, then T is in fact the
9537 specialization we want. That situation occurs when
9538 referencing a static data member within in its own
9539 class. We can use pointer equality, rather than
9540 same_type_p, because DECL_CONTEXT is always
9541 canonical. */
9544 }
9547 {
9553 }
9554 }
9555 else
9556 {
9557 /* A local variable. */
9559 /* Subsequent calls to pushdecl will fill this in. */
9562 }
9563 /* If we already have the specialization we need, there is
9564 nothing more to do. */
9566 {
9569 }
9571 /* Create a new node for the specialization we need. */
9574 {
9577 else
9582 }
9584 {
9585 /* Even if the original location is out of scope, the
9586 newly substituted one is not. */
9593 {
9594 /* It may seem that this case cannot occur, since:
9596 typedef void f();
9597 void g() { f x; }
9599 declares a function, not a variable. However:
9601 typedef void f();
9602 template <typename T> void g() { T t; }
9603 template void g<f>();
9605 is an attempt to declare a variable with function
9606 type. */
9608 /* R is not yet sufficiently initialized, so we
9609 just use its name. */
9612 }
9619 {
9624 }
9625 }
9631 /* Clear out the mangled name and RTL for the instantiation. */
9635 /* The initializer must not be expanded until it is required;
9636 see [temp.inst]. */
9642 {
9643 /* Possibly limit visibility based on template args. */
9646 {
9650 }
9652 }
9655 {
9656 /* A static data member declaration is always marked
9657 external when it is declared in-class, even if an
9658 initializer is present. We mimic the non-template
9659 processing here. */
9665 }
9667 {
9668 /* We're substituting this var in a decltype outside of its
9669 scope, such as for a lambda return type. Don't add it to
9670 local_specializations, do perform auto deduction. */
9672 tree init
9677 {
9680 }
9681 }
9682 else
9691 /* Preserve a typedef that names a type. */
9693 {
9696 }
9699 }
9704 }
9705 #undef RETURN
9707 out:
9708 /* Restore the file and line information. */
9712 }
9714 /* Substitute into the ARG_TYPES of a function type. */
9716 static tree
9718 tree args,
9719 tsubst_flags_t complain,
9720 tree in_decl)
9721 {
9722 tree remaining_arg_types;
9726 tree default_arg;
9737 {
9738 /* For a pack expansion, perform substitution on the
9739 entire expression. Later on, we'll handle the arguments
9740 one-by-one. */
9745 /* So that we'll spin through the parameters, one by one. */
9747 else
9748 {
9749 /* We only partially substituted into the parameter
9750 pack. Our type is TYPE_PACK_EXPANSION. */
9753 }
9754 }
9767 {
9769 {
9773 }
9775 }
9777 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9778 top-level qualifiers as required. */
9781 /* We do not substitute into default arguments here. The standard
9782 mandates that they be instantiated only when needed, which is
9783 done in build_over_call. */
9787 {
9788 /* We've instantiated a template before its default arguments
9789 have been parsed. This can happen for a nested template
9790 class, and is not an error unless we require the default
9791 argument in a call of this function. */
9792 remaining_arg_types =
9795 remaining_arg_types);
9796 }
9797 else
9798 remaining_arg_types =
9800 }
9803 }
9805 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9806 *not* handle the exception-specification for FNTYPE, because the
9807 initial substitution of explicitly provided template parameters
9808 during argument deduction forbids substitution into the
9809 exception-specification:
9811 [temp.deduct]
9813 All references in the function type of the function template to the
9814 corresponding template parameters are replaced by the specified tem-
9815 plate argument values. If a substitution in a template parameter or
9816 in the function type of the function template results in an invalid
9817 type, type deduction fails. [Note: The equivalent substitution in
9818 exception specifications is done only when the function is instanti-
9819 ated, at which point a program is ill-formed if the substitution
9820 results in an invalid type.] */
9822 static tree
9824 tree args,
9825 tsubst_flags_t complain,
9826 tree in_decl)
9827 {
9828 tree return_type;
9829 tree arg_types;
9830 tree fntype;
9832 /* The TYPE_CONTEXT is not used for function/method types. */
9835 /* Substitute the return type. */
9839 /* The standard does not presently indicate that creation of a
9840 function type with an invalid return type is a deduction failure.
9841 However, that is clearly analogous to creating an array of "void"
9842 or a reference to a reference. This is core issue #486. */
9845 {
9847 {
9850 else
9852 }
9854 }
9856 /* Substitute the argument types. */
9862 /* Construct a new type node and return it. */
9864 {
9867 }
9868 else
9869 {
9872 {
9873 /* [temp.deduct]
9875 Type deduction may fail for any of the following
9876 reasons:
9878 -- Attempting to create "pointer to member of T" when T
9879 is not a class type. */
9882 r);
9884 }
9888 }
9892 }
9894 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9895 ARGS into that specification, and return the substituted
9896 specification. If there is no specification, return NULL_TREE. */
9898 static tree
9900 tree args,
9901 tsubst_flags_t complain,
9902 tree in_decl)
9903 {
9904 tree specs;
9905 tree new_specs;
9910 {
9911 /* A noexcept-specifier. */
9912 new_specs = tsubst_copy_and_build
9916 }
9918 {
9921 else
9923 {
9924 tree spec;
9929 {
9930 /* Expand the pack expansion type. */
9933 in_decl);
9939 else
9940 {
9941 /* We're substituting into a member template, so
9942 we got a TYPE_PACK_EXPANSION back. Add that
9943 expansion and move on. */
9947 expanded_specs,
9948 complain);
9951 }
9952 }
9955 {
9958 else
9963 complain);
9964 }
9967 }
9968 }
9970 }
9972 /* Take the tree structure T and replace template parameters used
9973 therein with the argument vector ARGS. IN_DECL is an associated
9974 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9975 Issue error and warning messages under control of COMPLAIN. Note
9976 that we must be relatively non-tolerant of extensions here, in
9977 order to preserve conformance; if we allow substitutions that
9978 should not be allowed, we may allow argument deductions that should
9979 not succeed, and therefore report ambiguous overload situations
9980 where there are none. In theory, we could allow the substitution,
9981 but indicate that it should have failed, and allow our caller to
9982 make sure that the right thing happens, but we don't try to do this
9983 yet.
9985 This function is used for dealing with types, decls and the like;
9986 for expressions, use tsubst_expr or tsubst_copy. */
9988 tree
9990 {
10012 else
10017 /* Reuse typedefs. We need to do this to handle dependent attributes,
10018 such as attribute aligned. */
10022 {
10028 {
10032 }
10037 else
10038 /* The typedef is from a non-template context. */
10042 {
10044 r = cp_build_qualified_type_real
10048 }
10049 /* Else we must be instantiating the typedef, so fall through. */
10050 }
10063 {
10090 {
10096 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10097 needed. */
10105 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10106 with TREE_SIDE_EFFECTS that indicates this is not an integral
10107 constant expression. */
10110 {
10113 }
10119 {
10123 }
10125 /* [temp.deduct]
10127 Type deduction may fail for any of the following
10128 reasons:
10130 Attempting to create an array with a size that is
10131 zero or negative. */
10133 /* We must fail if performing argument deduction (as
10134 indicated by the state of complain), so that
10135 another substitution can be found. */
10139 {
10144 }
10147 }
10153 {
10166 {
10170 /* See through ARGUMENT_PACK_SELECT arguments. */
10172 }
10177 {
10179 /* If ARG is an argument pack, we don't actually want to
10180 perform a substitution here, because substitutions
10181 for argument packs are only done
10182 element-by-element. We can get to this point when
10183 substituting the type of a non-type template
10184 parameter pack, when that type actually contains
10185 template parameter packs from an outer template, e.g.,
10187 template<typename... Types> struct A {
10188 template<Types... Values> struct B { };
10189 }; */
10193 {
10199 return cp_build_qualified_type_real
10201 }
10203 {
10204 /* We are processing a type constructed from a
10205 template template parameter. */
10211 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10212 are resolving nested-types in the signature of a
10213 member function templates. Otherwise ARG is a
10214 TEMPLATE_DECL and is the real template to be
10215 instantiated. */
10223 complain);
10224 return cp_build_qualified_type_real
10226 }
10227 else
10228 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10230 }
10233 /* This can happen during the attempted tsubst'ing in
10234 unify. This means that we don't yet have any information
10235 about the template parameter in question. */
10238 /* If we get here, we must have been looking at a parm for a
10239 more deeply nested template. Make a new version of this
10240 template parameter, but with a lower level. */
10242 {
10247 {
10249 r = cp_build_qualified_type_real
10253 }
10254 else
10255 {
10266 /* We have reduced the level of the template
10267 template parameter, but not the levels of its
10268 template parameters, so canonical_type_parameter
10269 will not be able to find the canonical template
10270 template parameter for this level. Thus, we
10271 require structural equality checking to compare
10272 TEMPLATE_TEMPLATE_PARMs. */
10276 else
10280 {
10288 }
10289 }
10298 }
10301 }
10304 {
10312 {
10316 }
10319 {
10323 }
10326 {
10330 }
10336 }
10339 /* We should never be tsubsting a binfo. */
10343 /* A vector of template arguments. */
10349 {
10353 /* [temp.deduct]
10355 Type deduction may fail for any of the following
10356 reasons:
10358 -- Attempting to create a pointer to reference type.
10359 -- Attempting to create a reference to a reference type or
10360 a reference to void.
10362 Core issue 106 says that creating a reference to a reference
10363 during instantiation is no longer a cause for failure. We
10364 only enforce this check in strict C++98 mode. */
10368 {
10371 /* We keep track of the last time we issued this error
10372 message to avoid spewing a ton of messages during a
10373 single bad template instantiation. */
10376 {
10381 else
10384 }
10387 }
10389 {
10393 }
10395 /* In C++0x, during template argument substitution, when there is an
10396 attempt to create a reference to a reference type, reference
10397 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10399 "If a template-argument for a template-parameter T names a type
10400 that is a reference to a type A, an attempt to create the type
10401 'lvalue reference to cv T' creates the type 'lvalue reference to
10402 A,' while an attempt to create the type type rvalue reference to
10403 cv T' creates the type T"
10404 */
10405 r = cp_build_reference_type
10408 else
10413 /* Will this ever be needed for TYPE_..._TO values? */
10417 }
10419 {
10422 {
10423 /* [temp.deduct]
10425 Type deduction may fail for any of the following
10426 reasons:
10428 -- Attempting to create "pointer to member of T" when T
10429 is not a class type. */
10433 }
10435 {
10439 }
10441 {
10445 }
10448 {
10449 /* The type of the implicit object parameter gets its
10450 cv-qualifiers from the FUNCTION_TYPE. */
10451 tree memptr;
10455 complain);
10456 }
10457 else
10460 complain);
10461 }
10464 {
10465 tree fntype;
10466 tree specs;
10471 /* Substitute the exception specification. */
10473 in_decl);
10479 }
10481 {
10486 /* As an optimization, we avoid regenerating the array type if
10487 it will obviously be the same as T. */
10491 /* These checks should match the ones in grokdeclarator.
10493 [temp.deduct]
10495 The deduction may fail for any of the following reasons:
10497 -- Attempting to create an array with an element type that
10498 is void, a function type, or a reference type, or [DR337]
10499 an abstract class type. */
10503 {
10507 }
10509 {
10512 type);
10514 }
10519 {
10522 }
10525 }
10529 {
10538 }
10542 {
10548 }
10551 {
10561 {
10565 }
10567 {
10568 /* Normally, make_typename_type does not require that the CTX
10569 have complete type in order to allow things like:
10571 template <class T> struct S { typename S<T>::X Y; };
10573 But, such constructs have already been resolved by this
10574 point, so here CTX really should have complete type, unless
10575 it's a partial instantiation. */
10579 {
10583 }
10584 }
10591 {
10594 }
10597 {
10604 }
10606 return cp_build_qualified_type_real
10608 }
10611 {
10623 }
10631 {
10639 }
10642 {
10650 }
10653 {
10654 tree type;
10670 complain);
10671 }
10674 {
10675 tree type;
10691 else
10692 type = finish_decltype_type
10697 complain);
10698 }
10702 {
10704 tree packed_out =
10706 args,
10707 complain,
10708 in_decl);
10711 /* For template nontype argument packs, also substitute into
10712 the type. */
10717 }
10723 }
10724 }
10726 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10727 type of the expression on the left-hand side of the "." or "->"
10728 operator. */
10730 static tree
10733 {
10734 tree name;
10735 tree qualifying_scope;
10736 tree fns;
10737 tree optype;
10741 /* A baselink indicates a function from a base class. Both the
10742 BASELINK_ACCESS_BINFO and the base class referenced may
10743 indicate bases of the template class, rather than the
10744 instantiated class. In addition, lookups that were not
10745 ambiguous before may be ambiguous now. Therefore, we perform
10746 the lookup again. */
10753 {
10760 }
10768 /* If lookup found a single function, mark it as used at this
10769 point. (If it lookup found multiple functions the one selected
10770 later by overload resolution will be marked as used at that
10771 point.) */
10777 /* Add back the template arguments, if present. */
10782 template_args);
10783 /* Update the conversion operator type. */
10789 qualifying_scope,
10790 object_type);
10791 }
10793 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10794 true if the qualified-id will be a postfix-expression in-and-of
10795 itself; false if more of the postfix-expression follows the
10796 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10797 of "&". */
10799 static tree
10803 {
10804 tree expr;
10805 tree scope;
10806 tree name;
10808 tree template_args;
10812 /* Figure out what name to look up. */
10815 {
10822 }
10823 else
10824 {
10827 }
10829 /* Substitute into the qualifying scope. When there are no ARGS, we
10830 are just trying to simplify a non-dependent expression. In that
10831 case the qualifying scope may be dependent, and, in any case,
10832 substituting will not help. */
10835 {
10838 }
10839 else
10847 {
10849 {
10850 /* A BIT_NOT_EXPR is used to represent a destructor. */
10852 {
10856 }
10857 else
10860 }
10861 else
10865 {
10867 {
10871 }
10873 }
10874 }
10877 {
10879 scope);
10880 /* Remember that there was a reference to this entity. */
10882 }
10885 {
10891 }
10900 {
10901 expr = (adjust_result_of_qualified_name_lookup
10903 expr = (finish_qualified_id_expr
10907 }
10909 /* Expressions do not generally have reference type. */
10911 /* However, if we're about to form a pointer-to-member, we just
10912 want the referenced member referenced. */
10917 }
10919 /* Like tsubst, but deals with expressions. This function just replaces
10920 template parms; to finish processing the resultant expression, use
10921 tsubst_expr. */
10923 static tree
10925 {
10927 tree r;
10935 {
10940 {
10941 tree c;
10942 /* This can happen for a parameter name used later in a function
10943 declaration (such as in a late-specified return type). Just
10944 make a dummy decl, since it's only used for its type. */
10946 /* We copy T because want to tsubst the PARM_DECL only,
10947 not the following PARM_DECLs that are chained to T. */
10950 /* Give it the template pattern as its context; its true context
10951 hasn't been instantiated yet and this is good enough for
10952 mangling. */
10954 }
10962 {
10963 tree enum_type;
10964 tree v;
10968 /* There is no need to substitute into namespace-scope
10969 enumerators. */
10972 /* If ARGS is NULL, then T is known to be non-dependent. */
10976 /* Unfortunately, we cannot just call lookup_name here.
10977 Consider:
10979 template <int I> int f() {
10980 enum E { a = I };
10981 struct S { void g() { E e = a; } };
10982 };
10984 When we instantiate f<7>::S::g(), say, lookup_name is not
10985 clever enough to find f<7>::a. */
10986 enum_type
10996 /* We didn't find the name. That should never happen; if
10997 name-lookup found it during preliminary parsing, we
10998 should find it again here during instantiation. */
11000 }
11005 {
11006 tree ctx;
11011 {
11014 {
11018 }
11020 }
11021 }
11044 {
11045 /* Template template argument like the following example need
11046 special treatment:
11048 template <template <class> class TT> struct C {};
11049 template <class T> struct D {
11050 template <class U> struct E {};
11051 C<E> c; // #1
11052 };
11053 D<int> d; // #2
11055 We are processing the template argument `E' in #1 for
11056 the template instantiation #2. Originally, `E' is a
11057 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11058 have to substitute this with one having context `D<int>'. */
11062 }
11063 else
11064 /* Ordinary template template argument. */
11073 return build1
11079 {
11080 /* We only want to compute the number of arguments. */
11094 {
11101 else
11104 }
11105 else
11107 }
11108 /* Fall through */
11122 return build1
11127 {
11128 tree object;
11129 tree name;
11134 {
11138 }
11141 {
11151 }
11156 in_decl);
11157 else
11160 }
11198 return build_nt
11211 return build_nt
11218 {
11226 }
11231 {
11232 r = build_nt
11238 }
11241 {
11242 r = build_nt
11248 }
11251 {
11252 r = build_nt
11258 }
11261 {
11262 /* Substituted template arguments */
11271 }
11274 {
11294 }
11319 {
11322 }
11323 else
11327 /* This is handled by tsubst_copy_and_build. */
11332 in_decl),
11336 /* We shouldn't have built any of these during initial template
11337 generation. Instead, they should be built during instantiation
11338 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11342 r = build2
11360 }
11361 }
11363 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11365 static tree
11367 tree in_decl)
11368 {
11372 {
11378 {
11381 {
11387 }
11388 /* FALLTHRU */
11410 }
11411 }
11414 }
11416 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11418 static tree
11420 tree in_decl)
11421 {
11422 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11447 #undef RECUR
11448 }
11450 /* Substitute one OMP_FOR iterator. */
11452 static void
11457 {
11458 #define RECUR(NODE) \
11459 tsubst_expr ((NODE), args, complain, in_decl, \
11460 integral_constant_expression_p)
11469 {
11476 }
11480 {
11486 complain);
11487 else
11494 }
11497 {
11498 tree c;
11500 {
11511 }
11513 {
11518 {
11521 }
11522 }
11523 }
11529 else
11533 {
11544 {
11551 }
11552 else
11558 {
11564 }
11568 {
11575 }
11576 else
11582 }
11588 #undef RECUR
11589 }
11591 /* Like tsubst_copy for expressions, etc. but also does semantic
11592 processing. */
11594 static tree
11597 {
11598 #define RECUR(NODE) \
11599 tsubst_expr ((NODE), args, complain, in_decl, \
11600 integral_constant_expression_p)
11613 {
11615 {
11616 tree_stmt_iterator i;
11620 }
11635 else
11644 {
11645 tree decl;
11646 tree init;
11652 {
11655 tree decl;
11663 else
11665 }
11666 else
11667 {
11671 {
11672 /* By marking the declaration as instantiated, we avoid
11673 trying to instantiate it. Since instantiate_decl can't
11674 handle local variables, and since we've already done
11675 all that needs to be done, that's the right thing to
11676 do. */
11681 /* Anonymous aggregates are a special case. */
11683 else
11684 {
11688 {
11689 /* For __PRETTY_FUNCTION__ we have to adjust the
11690 initializer. */
11694 }
11695 else
11696 {
11700 /* If we had an initializer but it
11701 instantiated to nothing,
11702 value-initialize the object. This will
11703 only occur when the initializer was a
11704 pack expansion where the parameter packs
11705 used in that expansion were of length
11706 zero. */
11708 else
11710 }
11713 }
11714 }
11715 }
11717 /* A DECL_EXPR can also be used as an expression, in the condition
11718 clause of an if/for/while construct. */
11720 }
11758 {
11762 }
11770 else
11778 else
11805 {
11807 tree label;
11812 }
11818 /* Computed goto's must be tsubst'd into. On the other hand,
11819 non-computed gotos must not be; the identifier in question
11820 will have no binding. */
11822 else
11828 tmp = finish_asm_stmt
11835 {
11840 }
11845 {
11850 }
11851 else
11852 {
11857 else
11864 else
11870 else
11872 }
11876 {
11880 {
11882 /* Prevent instantiate_decl from trying to instantiate
11883 this variable. We've already done all that needs to be
11884 done. */
11887 }
11892 }
11900 {
11901 tree condition =
11903 args,
11910 }
11931 {
11946 integral_constant_expression_p);
11955 {
11959 }
11960 else
11961 {
11969 }
11983 }
12014 {
12019 }
12035 integral_constant_expression_p);
12036 }
12039 #undef RECUR
12040 }
12042 /* T is a postfix-expression that is not being used in a function
12043 call. Return the substituted version of T. */
12045 static tree
12047 tsubst_flags_t complain,
12048 tree in_decl)
12049 {
12053 else
12059 }
12061 /* Like tsubst but deals with expressions and performs semantic
12062 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12064 tree
12066 tree args,
12067 tsubst_flags_t complain,
12068 tree in_decl,
12071 {
12072 #define RECUR(NODE) \
12073 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12075 integral_constant_expression_p)
12077 tree op1;
12083 {
12086 /* Fall through. */
12088 {
12089 tree decl;
12090 cp_id_kind idk;
12095 {
12098 }
12100 /* Look up the name. */
12103 /* By convention, expressions use ERROR_MARK_NODE to indicate
12104 failure, not NULL_TREE. */
12110 integral_constant_expression_p,
12118 input_location);
12124 }
12127 {
12128 tree object;
12136 {
12139 }
12140 else
12147 else
12149 }
12152 {
12156 {
12157 /* A type conversion to reference type will be enclosed in
12158 such an indirect ref, but the substitution of the cast
12159 will have also added such an indirect ref. */
12162 }
12163 else
12166 }
12169 return build_nop
12178 {
12179 tree type;
12180 tree op;
12185 {
12190 }
12195 {
12208 }
12209 }
12227 complain);
12234 else
12236 in_decl);
12273 return build_x_binary_op
12277 ? ERROR_MARK
12281 ? ERROR_MARK
12284 complain);
12297 /* Fall through */
12302 {
12303 /* When there are no ARGS, we are trying to evaluate a
12304 non-dependent expression from the parser. Trying to do
12305 the substitutions may not work. */
12308 }
12309 else
12310 {
12318 }
12322 else
12338 {
12339 tree r = build_x_modify_expr
12343 complain);
12344 /* TREE_NO_WARNING must be set if either the expression was
12345 parenthesized or it uses an operator such as >>= rather
12346 than plain assignment. In the former case, it was already
12347 set and must be copied. In the latter case,
12348 build_x_modify_expr sets it and it must not be reset
12349 here. */
12353 }
12358 /* Remember that there was a reference to this entity. */
12364 {
12369 tree ret;
12373 else
12374 {
12378 }
12380 /* If there was an initializer in the original tree, but it
12381 instantiated to an empty list, then we should pass a
12382 non-NULL empty vector to tell build_new that it was an
12383 empty initializer() rather than no initializer. This can
12384 only happen when the initializer is a pack expansion whose
12385 parameter packs are of length zero. */
12388 else
12389 {
12393 else
12394 {
12397 }
12398 }
12405 complain);
12413 }
12416 return delete_sanity
12425 complain);
12428 {
12429 tree function;
12434 tree ret;
12437 /* When we parsed the expression, we determined whether or
12438 not Koenig lookup should be performed. */
12441 {
12446 }
12447 else
12448 {
12450 {
12456 }
12457 else
12461 in_decl,
12463 integral_constant_expression_p);
12467 }
12472 {
12478 else
12479 {
12480 /* Expand the pack expansion and push each entry onto
12481 CALL_ARGS. */
12484 {
12489 {
12494 }
12495 }
12496 else
12497 {
12498 /* A partial substitution. Add one entry. */
12500 }
12501 }
12502 }
12504 /* We do not perform argument-dependent lookup if normal
12505 lookup finds a non-function, in accordance with the
12506 expected resolution of DR 218. */
12509 /* If lookup found a member function, the Koenig lookup is
12510 not appropriate, even if an unqualified-name was used
12511 to denote the function. */
12514 /* Only do this when substitution turns a dependent call
12515 into a non-dependent call. */
12521 {
12525 }
12527 /* Remember that there was a reference to this entity. */
12534 {
12549 complain);
12550 else
12551 ret = (build_new_method_call
12556 complain));
12557 }
12558 else
12561 koenig_p,
12562 complain);
12567 }
12570 return build_x_conditional_expr
12574 complain);
12577 return finish_pseudo_destructor_expr
12583 {
12591 {
12592 /* We have pack expansions, so expand those and
12593 create a new list out of it. */
12596 tree chain;
12599 /* Expand the argument expressions. */
12607 /* Build the rest of the list. */
12612 /* Determine the number of arguments. */
12614 {
12617 }
12620 else
12621 {
12622 /* Since we only performed a partial substitution into
12623 the argument pack, we only return a single list
12624 node. */
12631 }
12633 /* Convert the argument vectors into a TREE_LIST */
12636 {
12637 /* Grab the Ith values. */
12638 i--;
12641 value
12645 /* Build the list (backwards). */
12647 }
12650 }
12666 }
12669 {
12670 tree object;
12671 tree object_type;
12672 tree member;
12676 /* Remember that there was a reference to this entity. */
12686 else
12692 {
12694 {
12699 {
12702 }
12704 {
12708 }
12709 }
12710 }
12713 {
12714 tree tmpl;
12715 tree args;
12717 /* Lookup the template functions now that we know what the
12718 scope is. */
12725 {
12728 args);
12729 member = (adjust_result_of_qualified_name_lookup
12731 object_type));
12732 }
12733 else
12734 {
12736 input_location);
12738 }
12739 }
12743 {
12745 {
12749 else
12752 }
12754 }
12760 complain);
12761 }
12764 return build_throw
12768 {
12776 tree r;
12781 /* digest_init will do the wrong thing if we let it. */
12785 /* We do not want to process the index of aggregate
12786 initializers as they are identifier nodes which will be
12787 looked up by digest_init. */
12793 {
12798 {
12799 /* Substitute into the pack expansion. */
12801 in_decl);
12804 ;
12806 /* Just move the argument into place. */
12808 else
12809 {
12810 /* Update the length of the final CONSTRUCTOR
12811 arguments vector, and note that we will need to
12812 copy.*/
12815 }
12816 }
12817 else
12819 }
12822 {
12827 idx++)
12828 {
12830 {
12835 }
12836 else
12838 }
12839 }
12848 }
12851 {
12856 }
12861 /* Fall through */
12864 {
12868 /* If the original type was a reference, we'll be wrapped in
12869 the appropriate INDIRECT_REF. */
12872 }
12877 in_decl));
12883 {
12892 }
12895 {
12901 integral_constant_expression_p);
12905 /* If the resulting list of expression statement is empty,
12906 fold it further into void_zero_node. */
12911 }
12915 /* As in finish_id_expression, we resolve enumeration constants
12916 to their underlying values. */
12918 {
12921 }
12925 {
12946 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12948 /* Now that we know visibility, instantiate the type so we have a
12949 declaration of the op() for later calls to lambda_function. */
12957 }
12960 /* Handle Objective-C++ constructs, if appropriate. */
12961 {
12962 tree subst
12967 }
12969 }
12971 #undef RECUR
12972 }
12974 /* Verify that the instantiated ARGS are valid. For type arguments,
12975 make sure that the type's linkage is ok. For non-type arguments,
12976 make sure they are constants if they are integral or enumerations.
12977 Emit an error under control of COMPLAIN, and return TRUE on error. */
12979 static bool
12981 {
12983 {
12993 }
12995 {
12996 /* [basic.link]: A name with no linkage (notably, the name
12997 of a class or enumeration declared in a local scope)
12998 shall not be used to declare an entity with linkage.
12999 This implies that names with no linkage cannot be used as
13000 template arguments
13002 DR 757 relaxes this restriction for C++0x. */
13007 {
13008 /* DR 488 makes use of a type with no linkage cause
13009 type deduction to fail. */
13011 {
13014 else
13017 }
13019 }
13020 /* In order to avoid all sorts of complications, we do not
13021 allow variably-modified types as template arguments. */
13023 {
13027 }
13028 }
13029 /* A non-type argument of integral or enumerated type must be a
13030 constant. */
13034 {
13038 }
13040 }
13042 static bool
13044 {
13049 {
13052 }
13056 }
13058 /* Instantiate the indicated variable or function template TMPL with
13059 the template arguments in TARG_PTR. */
13061 tree
13063 {
13065 tree fndecl;
13066 tree gen_tmpl;
13067 tree spec;
13068 HOST_WIDE_INT saved_processing_template_decl;
13075 /* If this function is a clone, handle it specially. */
13077 {
13078 tree spec;
13079 tree clone;
13081 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13082 DECL_CLONED_FUNCTION. */
13088 /* Look for the clone. */
13092 /* We should always have found the clone by now. */
13095 }
13097 /* Check to see if we already have this specialization. */
13100 /* The TMPL is a partial instantiation. To get a full set of
13101 arguments we must add the arguments used to perform the
13102 partial instantiation. */
13104 targ_ptr);
13106 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13107 but it doesn't seem to be on the hot path. */
13119 complain))
13122 /* We are building a FUNCTION_DECL, during which the access of its
13123 parameters and return types have to be checked. However this
13124 FUNCTION_DECL which is the desired context for access checking
13125 is not built yet. We solve this chicken-and-egg problem by
13126 deferring all checks until we have the FUNCTION_DECL. */
13129 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13130 (because, for example, we have encountered a non-dependent
13131 function call in the body of a template function and must now
13132 determine which of several overloaded functions will be called),
13133 within the instantiation itself we are not processing a
13134 template. */
13137 /* Substitute template parameters to obtain the specialization. */
13144 /* Now we know the specialization, compute access previously
13145 deferred. */
13148 /* Some typedefs referenced from within the template code need to be access
13149 checked at template instantiation time, i.e now. These types were
13150 added to the template at parsing time. Let's get those and perfom
13151 the acces checks then. */
13157 /* The DECL_TI_TEMPLATE should always be the immediate parent
13158 template, not the most general template. */
13161 /* If we've just instantiated the main entry point for a function,
13162 instantiate all the alternate entry points as well. We do this
13163 by cloning the instantiation of the main entry point, not by
13164 instantiating the template clones. */
13169 }
13171 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13172 NARGS elements of the arguments that are being used when calling
13173 it. TARGS is a vector into which the deduced template arguments
13174 are placed.
13176 Return zero for success, 2 for an incomplete match that doesn't resolve
13177 all the types, and 1 for complete failure. An error message will be
13178 printed only for an incomplete match.
13180 If FN is a conversion operator, or we are trying to produce a specific
13181 specialization, RETURN_TYPE is the return type desired.
13183 The EXPLICIT_TARGS are explicit template arguments provided via a
13184 template-id.
13186 The parameter STRICT is one of:
13188 DEDUCE_CALL:
13189 We are deducing arguments for a function call, as in
13190 [temp.deduct.call].
13192 DEDUCE_CONV:
13193 We are deducing arguments for a conversion function, as in
13194 [temp.deduct.conv].
13196 DEDUCE_EXACT:
13197 We are deducing arguments when doing an explicit instantiation
13198 as in [temp.explicit], when determining an explicit specialization
13199 as in [temp.expl.spec], or when taking the address of a function
13200 template, as in [temp.deduct.funcaddr]. */
13202 int
13204 tree explicit_targs,
13205 tree targs,
13208 tree return_type,
13209 unification_kind_t strict,
13211 {
13212 tree parms;
13213 tree fntype;
13221 {
13222 /* [temp.deduct]
13224 The specified template arguments must match the template
13225 parameters in kind (i.e., type, nontype, template), and there
13226 must not be more arguments than there are parameters;
13227 otherwise type deduction fails.
13229 Nontype arguments must match the types of the corresponding
13230 nontype template parameters, or must be convertible to the
13231 types of the corresponding nontype parameters as specified in
13232 _temp.arg.nontype_, otherwise type deduction fails.
13234 All references in the function type of the function template
13235 to the corresponding template parameters are replaced by the
13236 specified template argument values. If a substitution in a
13237 template parameter or in the function type of the function
13238 template results in an invalid type, type deduction fails. */
13241 tree converted_args;
13247 converted_args
13254 /* Substitute the explicit args into the function type. This is
13255 necessary so that, for instance, explicitly declared function
13256 arguments can match null pointed constants. If we were given
13257 an incomplete set of explicit args, we must not do semantic
13258 processing during substitution as we could create partial
13259 instantiations. */
13261 {
13265 /* Dig out the actual parm. */
13268 {
13271 }
13273 {
13276 }
13279 {
13281 tree targ;
13284 /* Mark the argument pack as "incomplete". We could
13285 still deduce more arguments during unification. */
13288 {
13292 }
13294 /* We have some incomplete argument packs. */
13296 }
13297 }
13300 /* Any substitution is guaranteed to be incomplete if there
13301 are incomplete argument packs, because we can still deduce
13302 more arguments. */
13304 else
13314 /* Place the explicitly specified arguments in TARGS. */
13317 }
13319 /* Never do unification on the 'this' parameter. */
13323 {
13332 }
13334 /* We allow incomplete unification without an error message here
13335 because the standard doesn't seem to explicitly prohibit it. Our
13336 callers must be ready to deal with unification failures in any
13337 event. */
13343 {
13346 /* Clear the "incomplete" flags on all argument packs. */
13348 {
13351 {
13354 }
13355 }
13356 }
13358 /* Now that we have bindings for all of the template arguments,
13359 ensure that the arguments deduced for the template template
13360 parameters have compatible template parameter lists. We cannot
13361 check this property before we have deduced all template
13362 arguments, because the template parameter types of a template
13363 template parameter might depend on prior template parameters
13364 deduced after the template template parameter. The following
13365 ill-formed example illustrates this issue:
13367 template<typename T, template<T> class C> void f(C<5>, T);
13369 template<int N> struct X {};
13371 void g() {
13372 f(X<5>(), 5l); // error: template argument deduction fails
13373 }
13375 The template parameter list of 'C' depends on the template type
13376 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13377 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13378 time that we deduce 'C'. */
13380 && !template_template_parm_bindings_ok_p
13385 /* All is well so far. Now, check:
13387 [temp.deduct]
13389 When all template arguments have been deduced, all uses of
13390 template parameters in nondeduced contexts are replaced with
13391 the corresponding deduced argument values. If the
13392 substitution results in an invalid type, as described above,
13393 type deduction fails. */
13394 {
13399 /* If we're looking for an exact match, check that what we got
13400 is indeed an exact match. It might not be if some template
13401 parameters are used in non-deduced contexts. */
13403 {
13406 tree sarg
13413 }
13414 }
13417 }
13419 /* Adjust types before performing type deduction, as described in
13420 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13421 sections are symmetric. PARM is the type of a function parameter
13422 or the return type of the conversion function. ARG is the type of
13423 the argument passed to the call, or the type of the value
13424 initialized with the result of the conversion function.
13425 ARG_EXPR is the original argument expression, which may be null. */
13427 static int
13431 tree arg_expr)
13432 {
13436 {
13441 {
13442 /* Swap PARM and ARG throughout the remainder of this
13443 function; the handling is precisely symmetric since PARM
13444 will initialize ARG rather than vice versa. */
13449 }
13452 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13453 too, but here handle it by stripping the reference from PARM
13454 rather than by adding it to ARG. */
13462 /* Nothing else to do in this case. */
13467 }
13470 {
13471 /* [temp.deduct.call]
13473 If P is not a reference type:
13475 --If A is an array type, the pointer type produced by the
13476 array-to-pointer standard conversion (_conv.array_) is
13477 used in place of A for type deduction; otherwise,
13479 --If A is a function type, the pointer type produced by
13480 the function-to-pointer standard conversion
13481 (_conv.func_) is used in place of A for type deduction;
13482 otherwise,
13484 --If A is a cv-qualified type, the top level
13485 cv-qualifiers of A's type are ignored for type
13486 deduction. */
13491 else
13493 }
13495 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13496 of the form T&&, where T is a template parameter, and the argument
13497 is an lvalue, T is deduced as A& */
13505 /* [temp.deduct.call]
13507 If P is a cv-qualified type, the top level cv-qualifiers
13508 of P's type are ignored for type deduction. If P is a
13509 reference type, the type referred to by P is used for
13510 type deduction. */
13513 {
13516 }
13518 /* DR 322. For conversion deduction, remove a reference type on parm
13519 too (which has been swapped into ARG). */
13524 }
13526 /* Most parms like fn_type_unification.
13528 If SUBR is 1, we're being called recursively (to unify the
13529 arguments of a function or method parameter of a function
13530 template). */
13532 static int
13534 tree targs,
13535 tree xparms,
13539 unification_kind_t strict,
13541 {
13547 tree parms;
13556 /* Reset the number of non-defaulted template arguments contained
13557 in in TARGS. */
13561 {
13577 }
13579 again:
13587 {
13600 /* We can't deduce anything from this, but we might get all the
13601 template args from other function args. */
13604 /* Conversions will be performed on a function argument that
13605 corresponds with a function parameter that contains only
13606 non-deducible template parameters and explicitly specified
13607 template parameters. */
13609 {
13610 tree type;
13614 else
13621 flags))
13625 }
13628 {
13631 {
13632 /* [temp.deduct.type]
13634 A template-argument can be deduced from a pointer to
13635 function or pointer to member function argument if
13636 the set of overloaded functions does not contain
13637 function templates and at most one of a set of
13638 overloaded functions provides a unique match. */
13644 }
13649 }
13651 {
13656 arg_expr);
13662 }
13663 }
13669 {
13670 /* Unify the remaining arguments with the pack expansion type. */
13671 tree argvec;
13674 /* Allocate a TREE_VEC and copy in all of the arguments */
13679 /* Copy the parameter into parmvec. */
13685 /* Advance to the end of the list of parameters. */
13687 }
13689 /* Fail if we've reached the end of the parm list, and more args
13690 are present, and the parm list isn't variadic. */
13693 /* Fail if parms are left and they don't have default values. */
13701 {
13702 tree tparm;
13709 /* If this is an undeduced nontype parameter that depends on
13710 a type parameter, try another pass; its type may have been
13711 deduced from a later argument than the one from which
13712 this parameter can be deduced. */
13718 /* Core issue #226 (C++0x) [temp.deduct]:
13720 If a template argument has not been deduced, its
13721 default template argument, if any, is used.
13723 When we are in C++98 mode, TREE_PURPOSE will either
13724 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13725 to explicitly check cxx_dialect here. */
13727 {
13735 else
13736 {
13738 /* The position of the first default template argument,
13739 is also the number of non-defaulted arguments in TARGS.
13740 Record that. */
13744 }
13745 }
13747 /* If the type parameter is a parameter pack, then it will
13748 be deduced to an empty parameter pack. */
13750 {
13751 tree arg;
13754 {
13758 }
13759 else
13766 }
13769 }
13770 #ifdef ENABLE_CHECKING
13773 #endif
13776 }
13778 /* Subroutine of type_unification_real. Args are like the variables
13779 at the call site. ARG is an overloaded function (or template-id);
13780 we try deducing template args from each of the overloads, and if
13781 only one succeeds, we go with that. Modifies TARGS and returns
13782 true on success. */
13784 static bool
13786 tree targs,
13787 tree parm,
13788 tree arg,
13789 unification_kind_t strict,
13791 {
13798 {
13801 }
13802 else
13806 /* Handle `&x' where `x' is some static or non-static member
13807 function name. */
13813 /* Strip baselink information. */
13818 {
13819 /* If we got some explicit template args, we need to plug them into
13820 the affected templates before we try to unify, in case the
13821 explicit args will completely resolve the templates in question. */
13827 {
13838 {
13843 {
13846 }
13847 }
13849 }
13850 }
13853 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13854 -- but the deduction does not succeed because the expression is
13855 not just the function on its own. */
13857 else
13863 {
13866 }
13868 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13869 to function or pointer to member function argument if the set of
13870 overloaded functions does not contain function templates and at most
13871 one of a set of overloaded functions provides a unique match.
13873 So if we found multiple possibilities, we return success but don't
13874 deduce anything. */
13877 {
13882 }
13887 }
13889 /* Core DR 115: In contexts where deduction is done and fails, or in
13890 contexts where deduction is not done, if a template argument list is
13891 specified and it, along with any default template arguments, identifies
13892 a single function template specialization, then the template-id is an
13893 lvalue for the function template specialization. */
13895 tree
13897 {
13910 {
13913 }
13915 {
13918 }
13920 {
13923 }
13926 {
13930 /* If we got some explicit template args, we need to plug them into
13931 the affected templates before we try to unify, in case the
13932 explicit args will completely resolve the templates in question. */
13940 {
13951 {
13954 {
13957 }
13959 {
13962 }
13963 }
13965 }
13967 {
13979 }
13981 /* There were no good options and at least one bad one, so let the
13982 user know what the problem is. */
13984 }
13986 }
13988 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13989 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13990 different overloads deduce different arguments for a given parm.
13991 ADDR_P is true if the expression for which deduction is being
13992 performed was of the form "& fn" rather than simply "fn".
13994 Returns 1 on success. */
13996 static int
13998 tree orig_targs,
13999 tree targs,
14000 tree parm,
14001 tree arg,
14002 unification_kind_t strict,
14005 {
14007 tree tempargs;
14010 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14011 to function or pointer to member function argument if the set of
14012 overloaded functions does not contain function templates and at most
14013 one of a set of overloaded functions provides a unique match.
14015 So if this is a template, just return success. */
14027 /* We don't copy orig_targs for this because if we have already deduced
14028 some template args from previous args, unify would complain when we
14029 try to deduce a template parameter for the same argument, even though
14030 there isn't really a conflict. */
14037 /* First make sure we didn't deduce anything that conflicts with
14038 explicitly specified args. */
14040 {
14047 /* Since we're unifying against ourselves, we will fill in
14048 template args used in the function parm list with our own
14049 template parms. Discard them. */
14053 }
14056 {
14061 }
14064 }
14066 /* PARM is a template class (perhaps with unbound template
14067 parameters). ARG is a fully instantiated type. If ARG can be
14068 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14069 TARGS are as for unify. */
14071 static tree
14073 {
14074 tree copy_of_targs;
14081 /* We need to make a new template argument vector for the call to
14082 unify. If we used TARGS, we'd clutter it up with the result of
14083 the attempted unification, even if this class didn't work out.
14084 We also don't want to commit ourselves to all the unifications
14085 we've already done, since unification is supposed to be done on
14086 an argument-by-argument basis. In other words, consider the
14087 following pathological case:
14089 template <int I, int J, int K>
14090 struct S {};
14092 template <int I, int J>
14093 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14095 template <int I, int J, int K>
14096 void f(S<I, J, K>, S<I, I, I>);
14098 void g() {
14099 S<0, 0, 0> s0;
14100 S<0, 1, 2> s2;
14102 f(s0, s2);
14103 }
14105 Now, by the time we consider the unification involving `s2', we
14106 already know that we must have `f<0, 0, 0>'. But, even though
14107 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14108 because there are two ways to unify base classes of S<0, 1, 2>
14109 with S<I, I, I>. If we kept the already deduced knowledge, we
14110 would reject the possibility I=1. */
14113 /* If unification failed, we're done. */
14119 }
14121 /* Given a template type PARM and a class type ARG, find the unique
14122 base type in ARG that is an instance of PARM. We do not examine
14123 ARG itself; only its base-classes. If there is not exactly one
14124 appropriate base class, return NULL_TREE. PARM may be the type of
14125 a partial specialization, as well as a plain template type. Used
14126 by unify. */
14128 static tree
14130 {
14132 tree binfo;
14138 /* The type could not be completed. */
14141 /* Walk in inheritance graph order. The search order is not
14142 important, and this avoids multiple walks of virtual bases. */
14144 {
14148 {
14149 /* If there is more than one satisfactory baseclass, then:
14151 [temp.deduct.call]
14153 If they yield more than one possible deduced A, the type
14154 deduction fails.
14156 applies. */
14161 }
14162 }
14165 }
14167 /* Returns the level of DECL, which declares a template parameter. */
14169 static int
14171 {
14173 {
14183 }
14185 }
14187 /* Decide whether ARG can be unified with PARM, considering only the
14188 cv-qualifiers of each type, given STRICT as documented for unify.
14189 Returns nonzero iff the unification is OK on that basis. */
14191 static int
14193 {
14199 {
14200 /* Although a CVR qualifier is ignored when being applied to a
14201 substituted template parameter ([8.3.2]/1 for example), that
14202 does not allow us to unify "const T" with "int&" because both
14203 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14204 It is ok when we're allowing additional CV qualifiers
14205 at the outer level [14.8.2.1]/3,1st bullet. */
14215 }
14226 }
14228 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14229 void
14231 {
14235 {
14238 }
14239 else
14240 {
14243 }
14244 }
14246 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14247 expansion at the end of PACKED_PARMS. Returns 0 if the type
14248 deduction succeeds, 1 otherwise. STRICT is the same as in
14249 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14250 call argument list. We'll need to adjust the arguments to make them
14251 types. SUBR tells us if this is from a recursive call to
14252 type_unification_real. */
14253 int
14257 {
14258 tree parm
14265 /* Determine the parameter packs we will be deducing from the
14266 pattern, and record their current deductions. */
14269 {
14273 /* Determine the index and level of this parameter pack. */
14276 /* Keep track of the parameter packs and their corresponding
14277 argument packs. */
14280 }
14282 /* Loop through all of the arguments that have not yet been
14283 unified and unify each with the pattern. */
14285 {
14288 /* For each parameter pack, clear out the deduced value so that
14289 we can deduce it again. */
14291 {
14296 }
14298 /* Unify the pattern with the current argument. */
14299 {
14306 {
14309 /* This mirrors what we do in type_unification_real. */
14311 {
14313 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14314 | UNIFY_ALLOW_MORE_CV_QUAL
14328 }
14331 {
14334 {
14335 /* [temp.deduct.type] A template-argument can be
14336 deduced from a pointer to function or pointer
14337 to member function argument if the set of
14338 overloaded functions does not contain function
14339 templates and at most one of a set of
14340 overloaded functions provides a unique
14341 match. */
14346 sub_strict)
14350 }
14353 {
14358 }
14359 }
14364 arg_strict |=
14367 }
14370 {
14371 /* For deduction from an init-list we need the actual list. */
14376 }
14377 }
14379 /* For each parameter pack, collect the deduced value. */
14381 {
14387 }
14388 }
14390 /* Verify that the results of unification with the parameter packs
14391 produce results consistent with what we've seen before, and make
14392 the deduced argument packs available. */
14394 {
14401 /* By default keep the original deduced argument pack.
14402 If necessary, more specific code is going to update the
14403 resulting deduced argument later down in this function. */
14407 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14408 actually deduce anything. */
14416 {
14417 /* Prepend the explicit arguments onto NEW_ARGS. */
14423 /* Copy the explicit arguments. */
14428 /* Copy the deduced arguments. */
14432 }
14435 {
14436 tree result;
14437 /* Build the deduced *_ARGUMENT_PACK. */
14439 {
14444 }
14445 else
14450 /* Note the deduced argument packs for this parameter
14451 pack. */
14453 }
14457 {
14458 /* We only had the explicitly-provided arguments before, but
14459 now we have a complete set of arguments. */
14465 }
14467 new_args))
14468 /* Inconsistent unification of this parameter pack. */
14470 }
14473 }
14475 /* Deduce the value of template parameters. TPARMS is the (innermost)
14476 set of template parameters to a template. TARGS is the bindings
14477 for those template parameters, as determined thus far; TARGS may
14478 include template arguments for outer levels of template parameters
14479 as well. PARM is a parameter to a template function, or a
14480 subcomponent of that parameter; ARG is the corresponding argument.
14481 This function attempts to match PARM with ARG in a manner
14482 consistent with the existing assignments in TARGS. If more values
14483 are deduced, then TARGS is updated.
14485 Returns 0 if the type deduction succeeds, 1 otherwise. The
14486 parameter STRICT is a bitwise or of the following flags:
14488 UNIFY_ALLOW_NONE:
14489 Require an exact match between PARM and ARG.
14490 UNIFY_ALLOW_MORE_CV_QUAL:
14491 Allow the deduced ARG to be more cv-qualified (by qualification
14492 conversion) than ARG.
14493 UNIFY_ALLOW_LESS_CV_QUAL:
14494 Allow the deduced ARG to be less cv-qualified than ARG.
14495 UNIFY_ALLOW_DERIVED:
14496 Allow the deduced ARG to be a template base class of ARG,
14497 or a pointer to a template base class of the type pointed to by
14498 ARG.
14499 UNIFY_ALLOW_INTEGER:
14500 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14501 case for more information.
14502 UNIFY_ALLOW_OUTER_LEVEL:
14503 This is the outermost level of a deduction. Used to determine validity
14504 of qualification conversions. A valid qualification conversion must
14505 have const qualified pointers leading up to the inner type which
14506 requires additional CV quals, except at the outer level, where const
14507 is not required [conv.qual]. It would be normal to set this flag in
14508 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14509 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14510 This is the outermost level of a deduction, and PARM can be more CV
14511 qualified at this point.
14512 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14513 This is the outermost level of a deduction, and PARM can be less CV
14514 qualified at this point. */
14516 static int
14518 {
14520 tree targ;
14521 tree tparm;
14524 /* I don't think this will do the right thing with respect to types.
14525 But the only case I've seen it in so far has been array bounds, where
14526 signedness is the only information lost, and I think that will be
14527 okay. */
14535 /* We can't deduce anything from this, but we might get all the
14536 template args from other function args. */
14539 /* If PARM uses template parameters, then we can't bail out here,
14540 even if ARG == PARM, since we won't record unifications for the
14541 template parameters. We might need them if we're trying to
14542 figure out which of two things is more specialized. */
14546 /* Handle init lists early, so the rest of the function can assume
14547 we're dealing with a type. */
14549 {
14554 /* Replace T with std::initializer_list<T> for deduction. */
14560 /* We can only deduce from an initializer list argument if the
14561 parameter is std::initializer_list; otherwise this is a
14562 non-deduced context. */
14568 {
14575 {
14577 /* It should only be possible to get here for a call. */
14579 elt_strict |= maybe_adjust_types_for_deduction
14582 }
14586 }
14588 /* If the std::initializer_list<T> deduction worked, replace the
14589 deduced A with std::initializer_list<A>. */
14591 {
14596 }
14598 }
14600 /* Immediately reject some pairs that won't unify because of
14601 cv-qualification mismatches. */
14604 /* It is the elements of the array which hold the cv quals of an array
14605 type, and the elements might be template type parms. We'll check
14606 when we recurse. */
14608 /* We check the cv-qualifiers when unifying with template type
14609 parameters below. We want to allow ARG `const T' to unify with
14610 PARM `T' for example, when computing which of two templates
14611 is more specialized, for example. */
14625 {
14629 /* In a type which contains a nested-name-specifier, template
14630 argument values cannot be deduced for template parameters used
14631 within the nested-name-specifier. */
14643 /* The PARM is not one we're trying to unify. Just check
14644 to see if it matches ARG. */
14651 /* Check for mixed types and values. */
14659 {
14660 /* ARG must be constructed from a template class or a template
14661 template parameter. */
14666 {
14669 tree parm_parms
14670 = DECL_INNERMOST_TEMPLATE_PARMS
14675 /* The resolution to DR150 makes clear that default
14676 arguments for an N-argument may not be used to bind T
14677 to a template template parameter with fewer than N
14678 parameters. It is not safe to permit the binding of
14679 default arguments as an extension, as that may change
14680 the meaning of a conforming program. Consider:
14682 struct Dense { static const unsigned int dim = 1; };
14684 template <template <typename> class View,
14685 typename Block>
14686 void operator+(float, View<Block> const&);
14688 template <typename Block,
14689 unsigned int Dim = Block::dim>
14690 struct Lvalue_proxy { operator float() const; };
14692 void
14693 test_1d (void) {
14694 Lvalue_proxy<Dense> p;
14695 float b;
14696 b + p;
14697 }
14699 Here, if Lvalue_proxy is permitted to bind to View, then
14700 the global operator+ will be used; if they are not, the
14701 Lvalue_proxy will be converted to float. */
14703 argvec,
14705 tf_none,
14711 /* Deduce arguments T, i from TT<T> or TT<i>.
14712 We check each element of PARMVEC and ARGVEC individually
14713 rather than the whole TREE_VEC since they can have
14714 different number of elements. */
14721 /* Check if the parameters end in a pack, making them
14722 variadic. */
14731 {
14735 UNIFY_ALLOW_NONE))
14737 }
14742 UNIFY_ALLOW_NONE,
14746 }
14749 /* Fall through to deduce template name. */
14750 }
14754 {
14755 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14757 /* Simple cases: Value already set, does match or doesn't. */
14762 }
14763 else
14764 {
14765 /* If PARM is `const T' and ARG is only `int', we don't have
14766 a match unless we are allowing additional qualification.
14767 If ARG is `const int' and PARM is just `T' that's OK;
14768 that binds `const int' to `T'. */
14773 /* Consider the case where ARG is `const volatile int' and
14774 PARM is `const T'. Then, T should be `volatile int'. */
14775 arg = cp_build_qualified_type_real
14780 /* Simple cases: Value already set, does match or doesn't. */
14786 /* Make sure that ARG is not a variable-sized array. (Note
14787 that were talking about variable-sized arrays (like
14788 `int[n]'), rather than arrays of unknown size (like
14789 `int[]').) We'll get very confused by such a type since
14790 the bound of the array will not be computable in an
14791 instantiation. Besides, such types are not allowed in
14792 ISO C++, so we can do as we please here. */
14796 /* Strip typedefs as in convert_template_argument. */
14798 }
14800 /* If ARG is a parameter pack or an expansion, we cannot unify
14801 against it unless PARM is also a parameter pack. */
14806 /* If the argument deduction results is a METHOD_TYPE,
14807 then there is a problem.
14808 METHOD_TYPE doesn't map to any real C++ type the result of
14809 the deduction can not be of that type. */
14823 /* The PARM is not one we're trying to unify. Just check
14824 to see if it matches ARG. */
14834 /* [temp.deduct.type] If, in the declaration of a function template
14835 with a non-type template-parameter, the non-type
14836 template-parameter is used in an expression in the function
14837 parameter-list and, if the corresponding template-argument is
14838 deduced, the template-argument type shall match the type of the
14839 template-parameter exactly, except that a template-argument
14840 deduced from an array bound may be of any integral type.
14841 The non-type parameter might use already deduced type parameters. */
14844 /* Template-parameter dependent expression. Just accept it for now.
14845 It will later be processed in convert_template_argument. */
14846 ;
14852 /* Convert the ARG to the type of PARM; the deduced non-type
14853 template argument must exactly match the types of the
14854 corresponding parameter. */
14857 /* We haven't deduced the type of this parameter yet. Try again
14858 later. */
14860 else
14863 /* If ARG is a parameter pack or an expansion, we cannot unify
14864 against it unless PARM is also a parameter pack. */
14873 {
14874 /* A pointer-to-member constant can be unified only with
14875 another constant. */
14879 /* Just unify the class member. It would be useless (and possibly
14880 wrong, depending on the strict flags) to unify also
14881 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14882 arg refer to the same variable, even if through different
14883 classes. For instance:
14885 struct A { int x; };
14886 struct B : A { };
14888 Unification of &A::x and &B::x must succeed. */
14891 }
14894 {
14898 /* [temp.deduct.call]
14900 A can be another pointer or pointer to member type that can
14901 be converted to the deduced A via a qualification
14902 conversion (_conv.qual_).
14904 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14905 This will allow for additional cv-qualification of the
14906 pointed-to types if appropriate. */
14909 /* The derived-to-base conversion only persists through one
14910 level of pointers. */
14915 }
14930 {
14931 tree parm_max;
14932 tree arg_max;
14936 /* Our representation of array types uses "N - 1" as the
14937 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14938 not an integer constant. We cannot unify arbitrarily
14939 complex expressions, so we eliminate the MINUS_EXPRs
14940 here. */
14944 {
14947 }
14951 {
14952 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14953 trying to unify the type of a variable with the type
14954 of a template parameter. For example:
14956 template <unsigned int N>
14957 void f (char (&) [N]);
14958 int g();
14959 void h(int i) {
14960 char a[g(i)];
14961 f(a);
14962 }
14964 Here, the type of the ARG will be "int [g(i)]", and
14965 may be a SAVE_EXPR, etc. */
14969 }
14971 /* If only one of the bounds used a MINUS_EXPR, compensate
14972 by adding one to the other bound. */
14975 integer_type_node,
14976 parm_max,
14977 integer_one_node);
14980 integer_type_node,
14981 arg_max,
14982 integer_one_node);
14986 }
15000 /* We have already checked cv-qualification at the top of the
15001 function. */
15005 /* As far as unification is concerned, this wins. Later checks
15006 will invalidate it if necessary. */
15009 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15010 /* Type INTEGER_CST can come from ordinary constant template args. */
15020 {
15029 UNIFY_ALLOW_NONE))
15032 }
15040 {
15047 strict);
15048 }
15051 {
15055 {
15056 /* First, we try to unify the PARM and ARG directly. */
15061 {
15062 /* Fallback to the special case allowed in
15063 [temp.deduct.call]:
15065 If P is a class, and P has the form
15066 template-id, then A can be a derived class of
15067 the deduced A. Likewise, if P is a pointer to
15068 a class of the form template-id, A can be a
15069 pointer to a derived class pointed to by the
15070 deduced A. */
15075 }
15076 }
15080 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15081 Then, we should unify `int' and `U'. */
15083 else
15084 /* There's no chance of unification succeeding. */
15089 }
15096 {
15099 tree a;
15105 /* CV qualifications for methods can never be deduced, they must
15106 match exactly. We need to check them explicitly here,
15107 because type_unification_real treats them as any other
15108 cv-qualified parameter. */
15110 && (!check_cv_quals_for_unify
15130 LOOKUP_NORMAL);
15131 }
15134 /* Unify a pointer to member with a pointer to member function, which
15135 deduces the type of the member as a function type. */
15137 {
15138 tree method_type;
15139 tree fntype;
15141 /* Check top-level cv qualifiers */
15149 /* Determine the type of the function we are unifying against. */
15151 fntype =
15155 /* Extract the cv-qualifiers of the member function from the
15156 implicit object parameter and place them on the function
15157 type to be restored later. */
15160 }
15168 strict);
15179 /* Matched cases are handled by the ARG == PARM test above. */
15183 /* A non-type template parameter that is a variable should be a
15184 an integral constant, in which case, it whould have been
15185 folded into its (constant) value. So we should not be getting
15186 a variable here. */
15191 {
15199 {
15201 {
15203 /* We can unify against something with a trailing
15204 parameter pack. */
15206 else
15207 /* Since there is something following the pack
15208 expansion, we cannot unify this template argument
15209 list. */
15211 }
15212 }
15215 /* If we don't have enough arguments to satisfy the parameters
15216 (not counting the pack expression at the end), or we have
15217 too many arguments for a parameter list that doesn't end in
15218 a pack expression, we can't unify. */
15223 /* Unify all of the parameters that precede the (optional)
15224 pack expression. */
15226 {
15230 }
15238 }
15244 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15245 nodes. */
15249 /* Unification fails if we hit an error node. */
15255 /* We must be looking at an expression. This can happen with
15256 something like:
15258 template <int I>
15259 void foo(S<I>, S<I + 2>);
15261 This is a "nondeduced context":
15263 [deduct.type]
15265 The nondeduced contexts are:
15267 --A type that is a template-id in which one or more of
15268 the template-arguments is an expression that references
15269 a template-parameter.
15271 In these cases, we assume deduction succeeded, but don't
15272 actually infer any unifications. */
15277 else
15279 }
15280 }
15281 \f
15282 /* Note that DECL can be defined in this translation unit, if
15283 required. */
15285 static void
15287 {
15288 tree clone;
15292 }
15294 /* Called if RESULT is explicitly instantiated, or is a member of an
15295 explicitly instantiated class. */
15297 void
15299 {
15302 /* If this entity has already been written out, it's too late to
15303 make any modifications. */
15308 /* The TREE_PUBLIC flag for function declarations will have been
15309 set correctly by tsubst. */
15312 /* This might have been set by an earlier implicit instantiation. */
15317 else
15318 {
15320 /* Always make artificials weak. */
15323 /* For WIN32 we also want to put explicit instantiations in
15324 linkonce sections. */
15327 }
15329 /* If EXTERN_P, then this function will not be emitted -- unless
15330 followed by an explicit instantiation, at which point its linkage
15331 will be adjusted. If !EXTERN_P, then this function will be
15332 emitted here. In neither circumstance do we want
15333 import_export_decl to adjust the linkage. */
15335 }
15337 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15338 important template arguments. If any are missing, we check whether
15339 they're important by using error_mark_node for substituting into any
15340 args that were used for partial ordering (the ones between ARGS and END)
15341 and seeing if it bubbles up. */
15343 static bool
15345 {
15350 {
15353 }
15355 {
15357 {
15361 }
15362 }
15364 }
15366 /* Given two function templates PAT1 and PAT2, return:
15368 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15369 -1 if PAT2 is more specialized than PAT1.
15370 0 if neither is more specialized.
15372 LEN indicates the number of parameters we should consider
15373 (defaulted parameters should not be considered).
15375 The 1998 std underspecified function template partial ordering, and
15376 DR214 addresses the issue. We take pairs of arguments, one from
15377 each of the templates, and deduce them against each other. One of
15378 the templates will be more specialized if all the *other*
15379 template's arguments deduce against its arguments and at least one
15380 of its arguments *does* *not* deduce against the other template's
15381 corresponding argument. Deduction is done as for class templates.
15382 The arguments used in deduction have reference and top level cv
15383 qualifiers removed. Iff both arguments were originally reference
15384 types *and* deduction succeeds in both directions, the template
15385 with the more cv-qualified argument wins for that pairing (if
15386 neither is more cv-qualified, they both are equal). Unlike regular
15387 deduction, after all the arguments have been deduced in this way,
15388 we do *not* verify the deduced template argument values can be
15389 substituted into non-deduced contexts.
15391 The logic can be a bit confusing here, because we look at deduce1 and
15392 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15393 can find template arguments for pat1 to make arg1 look like arg2, that
15394 means that arg2 is at least as specialized as arg1. */
15396 int
15398 {
15411 /* Remove the this parameter from non-static member functions. If
15412 one is a non-static member function and the other is not a static
15413 member function, remove the first parameter from that function
15414 also. This situation occurs for operator functions where we
15415 locate both a member function (with this pointer) and non-member
15416 operator (with explicit first operand). */
15418 {
15423 }
15425 {
15428 {
15429 len--;
15431 }
15432 }
15434 /* If only one is a conversion operator, they are unordered. */
15438 /* Consider the return type for a conversion function */
15440 {
15443 len++;
15444 }
15446 processing_template_decl++;
15452 /* Stop when an ellipsis is seen. */
15454 {
15463 {
15464 /* When both arguments are pack expansions, we need only
15465 unify the patterns themselves. */
15469 /* This is the last comparison we need to do. */
15471 }
15474 {
15477 }
15480 {
15483 }
15486 {
15487 /* Only of the args is a reference, see if we should apply
15488 array/function pointer decay to it. This is not part of
15489 DR214, but is, IMHO, consistent with the deduction rules
15490 for the function call itself, and with our earlier
15491 implementation of the underspecified partial ordering
15492 rules. (nathan). */
15494 {
15496 {
15499 /* FALLTHROUGH. */
15506 }
15507 }
15508 else
15509 {
15511 {
15514 /* FALLTHROUGH. */
15521 }
15522 }
15523 }
15529 {
15535 /* Setup the parameter vector, which contains only ARG1. */
15538 /* Setup the argument vector, which contains the remaining
15539 arguments. */
15548 /* We cannot deduce in the other direction, because ARG1 is
15549 a pack expansion but ARG2 is not. */
15551 }
15553 {
15559 /* Setup the parameter vector, which contains only ARG1. */
15562 /* Setup the argument vector, which contains the remaining
15563 arguments. */
15572 /* We cannot deduce in the other direction, because ARG2 is
15573 a pack expansion but ARG1 is not.*/
15575 }
15577 else
15578 {
15579 /* The normal case, where neither argument is a pack
15580 expansion. */
15583 }
15585 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15586 arg2, then arg2 is not as specialized as arg1. */
15592 /* "If, for a given type, deduction succeeds in both directions
15593 (i.e., the types are identical after the transformations above)
15594 and if the type from the argument template is more cv-qualified
15595 than the type from the parameter template (as described above)
15596 that type is considered to be more specialized than the other. If
15597 neither type is more cv-qualified than the other then neither type
15598 is more specialized than the other." */
15602 {
15607 }
15610 /* We've failed to deduce something in either direction.
15611 These must be unordered. */
15616 /* We have already processed all of the arguments in our
15617 handing of the pack expansion type. */
15622 }
15624 /* "In most cases, all template parameters must have values in order for
15625 deduction to succeed, but for partial ordering purposes a template
15626 parameter may remain without a value provided it is not used in the
15627 types being used for partial ordering."
15629 Thus, if we are missing any of the targs1 we need to substitute into
15630 origs1, then pat2 is not as specialized as pat1. This can happen when
15631 there is a nondeduced context. */
15637 processing_template_decl--;
15639 /* All things being equal, if the next argument is a pack expansion
15640 for one function but not for the other, prefer the
15641 non-variadic function. FIXME this is bogus; see c++/41958. */
15645 {
15648 }
15654 else
15656 }
15658 /* Determine which of two partial specializations is more specialized.
15660 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15661 to the first partial specialization. The TREE_VALUE is the
15662 innermost set of template parameters for the partial
15663 specialization. PAT2 is similar, but for the second template.
15665 Return 1 if the first partial specialization is more specialized;
15666 -1 if the second is more specialized; 0 if neither is more
15667 specialized.
15669 See [temp.class.order] for information about determining which of
15670 two templates is more specialized. */
15672 static int
15674 {
15675 tree targs;
15683 /* Just like what happens for functions, if we are ordering between
15684 different class template specializations, we may encounter dependent
15685 types in the arguments, and we need our dependency check functions
15686 to behave correctly. */
15692 {
15695 }
15701 {
15704 }
15707 /* In the case of a tie where at least one of the class templates
15708 has a parameter pack at the end, the template with the most
15709 non-packed parameters wins. */
15711 && any_deductions
15714 {
15720 /* We don't count the pack expansion at the end. */
15730 }
15733 }
15735 /* Return the template arguments that will produce the function signature
15736 DECL from the function template FN, with the explicit template
15737 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15738 also match. Return NULL_TREE if no satisfactory arguments could be
15739 found. */
15741 static tree
15743 {
15746 tree decl_type;
15747 tree decl_arg_types;
15750 tree arg;
15752 /* Substitute the explicit template arguments into the type of DECL.
15753 The call to fn_type_unification will handle substitution into the
15754 FN. */
15757 {
15758 tree tmpl;
15759 tree converted_args;
15763 else
15764 /* We can get here for some invalid specializations. */
15767 converted_args
15770 tf_none,
15779 }
15781 /* Never do unification on the 'this' parameter. */
15800 }
15802 /* Return the innermost template arguments that, when applied to a
15803 template specialization whose innermost template parameters are
15804 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15805 ARGS.
15807 For example, suppose we have:
15809 template <class T, class U> struct S {};
15810 template <class T> struct S<T*, int> {};
15812 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15813 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15814 int}. The resulting vector will be {double}, indicating that `T'
15815 is bound to `double'. */
15817 static tree
15819 {
15821 tree deduced_args;
15822 tree innermost_deduced_args;
15826 {
15830 innermost_deduced_args);
15831 }
15832 else
15838 UNIFY_ALLOW_NONE))
15845 /* Verify that nondeduced template arguments agree with the type
15846 obtained from argument deduction.
15848 For example:
15850 struct A { typedef int X; };
15851 template <class T, class U> struct C {};
15852 template <class T> struct C<T, typename T::X> {};
15854 Then with the instantiation `C<A, int>', we can deduce that
15855 `T' is `A' but unify () does not check whether `typename T::X'
15856 is `int'. */
15859 /* We only need to check the innermost arguments; the other
15860 arguments will always agree. */
15865 /* Now that we have bindings for all of the template arguments,
15866 ensure that the arguments deduced for the template template
15867 parameters have compatible template parameter lists. See the use
15868 of template_template_parm_bindings_ok_p in fn_type_unification
15869 for more information. */
15874 }
15876 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15877 Return the TREE_LIST node with the most specialized template, if
15878 any. If there is no most specialized template, the error_mark_node
15879 is returned.
15881 Note that this function does not look at, or modify, the
15882 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15883 returned is one of the elements of INSTANTIATIONS, callers may
15884 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15885 and retrieve it from the value returned. */
15887 tree
15889 {
15896 {
15902 fate--;
15907 fate++;
15912 {
15913 /* Equally specialized, move to next function. If there
15914 is no next function, nothing's most specialized. */
15919 }
15920 }
15923 /* Now verify that champ is better than everything earlier in the
15924 instantiation list. */
15932 {
15935 }
15937 processing_template_decl--;
15943 }
15945 /* If DECL is a specialization of some template, return the most
15946 general such template. Otherwise, returns NULL_TREE.
15948 For example, given:
15950 template <class T> struct S { template <class U> void f(U); };
15952 if TMPL is `template <class U> void S<int>::f(U)' this will return
15953 the full template. This function will not trace past partial
15954 specializations, however. For example, given in addition:
15956 template <class T> struct S<T*> { template <class U> void f(U); };
15958 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15959 `template <class T> template <class U> S<T*>::f(U)'. */
15961 tree
15963 {
15964 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15965 an immediate specialization. */
15967 {
15971 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15972 template friend. */
15977 }
15979 /* Look for more and more general templates. */
15981 {
15982 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15983 (See cp-tree.h for details.) */
15991 /* Stop if we run into an explicitly specialized class template. */
15998 }
16001 }
16003 /* Return the most specialized of the class template partial
16004 specializations of TMPL which can produce TYPE, a specialization of
16005 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16006 a _TYPE node corresponding to the partial specialization, while the
16007 TREE_PURPOSE is the set of template arguments that must be
16008 substituted into the TREE_TYPE in order to generate TYPE.
16010 If the choice of partial specialization is ambiguous, a diagnostic
16011 is issued, and the error_mark_node is returned. If there are no
16012 partial specializations of TMPL matching TYPE, then NULL_TREE is
16013 returned. */
16015 static tree
16017 {
16019 tree t;
16020 tree champ;
16023 tree args;
16029 /* For determining which partial specialization to use, only the
16030 innermost args are interesting. */
16032 {
16035 }
16038 {
16039 tree partial_spec_args;
16040 tree spec_args;
16048 {
16051 /* Discard the outer levels of args, and then substitute in the
16052 template args from the enclosing class. */
16054 partial_spec_args = tsubst_template_args
16057 /* PARMS already refers to just the innermost parms, but the
16058 template parms in partial_spec_args had their levels lowered
16059 by tsubst, so we need to do the same for the parm list. We
16060 can't just tsubst the TREE_VEC itself, as tsubst wants to
16061 treat a TREE_VEC as an argument vector. */
16067 }
16069 partial_spec_args =
16072 partial_spec_args),
16083 partial_spec_args,
16084 args);
16086 {
16091 }
16092 }
16102 {
16105 ;
16106 else
16107 {
16109 {
16112 {
16115 }
16116 }
16118 }
16119 }
16123 {
16126 {
16129 }
16130 }
16133 {
16141 {
16144 }
16147 }
16150 }
16152 /* Explicitly instantiate DECL. */
16154 void
16156 {
16161 /* An error occurred, for which grokdeclarator has already issued
16162 an appropriate message. */
16165 {
16168 }
16170 {
16171 /* There is an asymmetry here in the way VAR_DECLs and
16172 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16173 the latter, the DECL we get back will be marked as a
16174 template instantiation, and the appropriate
16175 DECL_TEMPLATE_INFO will be set up. This does not happen for
16176 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16177 should handle VAR_DECLs as it currently handles
16178 FUNCTION_DECLs. */
16180 {
16183 }
16186 {
16189 }
16191 {
16196 }
16197 }
16199 {
16202 }
16203 else
16206 /* Check for various error cases. Note that if the explicit
16207 instantiation is valid the RESULT will currently be marked as an
16208 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16209 until we get here. */
16212 {
16213 /* DR 259 [temp.spec].
16215 Both an explicit instantiation and a declaration of an explicit
16216 specialization shall not appear in a program unless the explicit
16217 instantiation follows a declaration of the explicit specialization.
16219 For a given set of template parameters, if an explicit
16220 instantiation of a template appears after a declaration of an
16221 explicit specialization for that template, the explicit
16222 instantiation has no effect. */
16224 }
16226 {
16227 /* [temp.spec]
16229 No program shall explicitly instantiate any template more
16230 than once.
16232 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16233 the first instantiation was `extern' and the second is not,
16234 and EXTERN_P for the opposite case. */
16237 /* If an "extern" explicit instantiation follows an ordinary
16238 explicit instantiation, the template is instantiated. */
16241 }
16243 {
16246 }
16248 {
16251 }
16254 ;
16256 {
16259 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16262 }
16263 else
16271 }
16273 static void
16275 {
16281 {
16284 }
16285 }
16287 /* Called from do_type_instantiation through binding_table_foreach to
16288 do recursive instantiation for the type bound in ENTRY. */
16289 static void
16291 {
16297 }
16299 /* Called from do_type_instantiation to instantiate a member
16300 (a member function or a static member variable) of an
16301 explicitly instantiated class template. */
16302 static void
16304 {
16309 }
16311 /* Perform an explicit instantiation of template class T. STORAGE, if
16312 non-null, is the RID for extern, inline or static. COMPLAIN is
16313 nonzero if this is called from the parser, zero if called recursively,
16314 since the standard is unclear (as detailed below). */
16316 void
16318 {
16328 {
16331 }
16336 {
16339 t);
16341 }
16344 {
16346 {
16348 {
16351 "ISO C++ 1998 forbids the use of %<extern%> on "
16353 }
16354 else
16356 "ISO C++ forbids the use of %qE"
16358 }
16366 else
16367 {
16369 storage);
16371 }
16372 }
16375 {
16376 /* DR 259 [temp.spec].
16378 Both an explicit instantiation and a declaration of an explicit
16379 specialization shall not appear in a program unless the explicit
16380 instantiation follows a declaration of the explicit specialization.
16382 For a given set of template parameters, if an explicit
16383 instantiation of a template appears after a declaration of an
16384 explicit specialization for that template, the explicit
16385 instantiation has no effect. */
16387 }
16389 {
16390 /* [temp.spec]
16392 No program shall explicitly instantiate any template more
16393 than once.
16395 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16396 instantiation was `extern'. If EXTERN_P then the second is.
16397 These cases are OK. */
16404 /* If we've already instantiated the template, just return now. */
16407 }
16415 {
16416 tree tmp;
16418 /* In contrast to implicit instantiation, where only the
16419 declarations, and not the definitions, of members are
16420 instantiated, we have here:
16422 [temp.explicit]
16424 The explicit instantiation of a class template specialization
16425 implies the instantiation of all of its members not
16426 previously explicitly specialized in the translation unit
16427 containing the explicit instantiation.
16429 Of course, we can't instantiate member template classes, since
16430 we don't have any arguments for them. Note that the standard
16431 is unclear on whether the instantiation of the members are
16432 *explicit* instantiations or not. However, the most natural
16433 interpretation is that it should be an explicit instantiation. */
16448 }
16449 }
16451 /* Given a function DECL, which is a specialization of TMPL, modify
16452 DECL to be a re-instantiation of TMPL with the same template
16453 arguments. TMPL should be the template into which tsubst'ing
16454 should occur for DECL, not the most general template.
16456 One reason for doing this is a scenario like this:
16458 template <class T>
16459 void f(const T&, int i);
16461 void g() { f(3, 7); }
16463 template <class T>
16464 void f(const T& t, const int i) { }
16466 Note that when the template is first instantiated, with
16467 instantiate_template, the resulting DECL will have no name for the
16468 first parameter, and the wrong type for the second. So, when we go
16469 to instantiate the DECL, we regenerate it. */
16471 static void
16473 {
16474 /* The arguments used to instantiate DECL, from the most general
16475 template. */
16476 tree args;
16477 tree code_pattern;
16482 /* Make sure that we can see identifiers, and compute access
16483 correctly. */
16487 {
16488 tree decl_parm;
16489 tree pattern_parm;
16490 tree specs;
16503 specs);
16505 /* Merge parameter declarations. */
16508 pattern_parm
16512 {
16513 tree parm_type;
16514 tree attributes;
16519 NULL_TREE);
16525 {
16528 }
16531 }
16532 /* Merge any parameters that match with the function parameter
16533 pack. */
16535 {
16537 tree expanded_types;
16538 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16539 the parameters in this function parameter pack. */
16544 {
16545 tree parm_type;
16546 tree attributes;
16549 /* Rename the parameter to include the index. */
16558 {
16561 }
16563 }
16564 }
16565 /* Merge additional specifiers from the CODE_PATTERN. */
16569 }
16571 {
16579 }
16580 else
16584 }
16586 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16587 substituted to get DECL. */
16589 tree
16591 {
16594 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16595 for the instantiation. This is not always the most general
16596 template. Consider, for example:
16598 template <class T>
16599 struct S { template <class U> void f();
16600 template <> void f<int>(); };
16602 and an instantiation of S<double>::f<int>. We want TD to be the
16603 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16605 more general template. */
16607 /* We must also deal with friend templates. Given:
16609 template <class T> struct S {
16610 template <class U> friend void f() {};
16611 };
16613 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16614 so far as the language is concerned, but that's still
16615 where we get the pattern for the instantiation from. On
16616 other hand, if the definition comes outside the class, say:
16618 template <class T> struct S {
16619 template <class U> friend void f();
16620 };
16621 template <class U> friend void f() {}
16623 we don't need to look any further. That's what the check for
16624 DECL_INITIAL is for. */
16628 {
16629 /* The present template, TD, should not be a definition. If it
16630 were a definition, we should be using it! Note that we
16631 cannot restructure the loop to just keep going until we find
16632 a template with a definition, since that might go too far if
16633 a specialization was declared, but not defined. */
16637 /* Fetch the more general template. */
16639 }
16642 }
16644 /* Returns true if we need to instantiate this template instance even if we
16645 know we aren't going to emit it.. */
16647 bool
16649 {
16650 /* We always instantiate inline functions so that we can inline them. An
16651 explicit instantiation declaration prohibits implicit instantiation of
16652 non-inline functions. With high levels of optimization, we would
16653 normally inline non-inline functions -- but we're not allowed to do
16654 that for "extern template" functions. Therefore, we check
16655 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16658 /* And we need to instantiate static data members so that
16659 their initializers are available in integral constant
16660 expressions. */
16663 }
16665 /* Produce the definition of D, a _DECL generated from a template. If
16666 DEFER_OK is nonzero, then we don't have to actually do the
16667 instantiation now; we just have to do it sometime. Normally it is
16668 an error if this is an explicit instantiation but D is undefined.
16669 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16670 explicitly instantiated class template. */
16672 tree
16675 {
16677 tree gen_args;
16678 tree args;
16679 tree td;
16680 tree code_pattern;
16681 tree spec;
16682 tree gen_tmpl;
16688 /* This function should only be used to instantiate templates for
16689 functions and static member variables. */
16693 /* Variables are never deferred; if instantiation is required, they
16694 are instantiated right away. That allows for better code in the
16695 case that an expression refers to the value of the variable --
16696 if the variable has a constant value the referring expression can
16697 take advantage of that fact. */
16701 /* Don't instantiate cloned functions. Instead, instantiate the
16702 functions they cloned. */
16708 /* D has already been instantiated or explicitly specialized, so
16709 there's nothing for us to do here.
16711 It might seem reasonable to check whether or not D is an explicit
16712 instantiation, and, if so, stop here. But when an explicit
16713 instantiation is deferred until the end of the compilation,
16714 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16715 the instantiation. */
16718 /* Check to see whether we know that this template will be
16719 instantiated in some other file, as with "extern template"
16720 extension. */
16723 /* In general, we do not instantiate such templates. */
16731 /* We should already have the extra args. */
16734 /* And what's in the hash table should match D. */
16738 /* This needs to happen before any tsubsting. */
16744 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16745 for the instantiation. */
16749 /* We should never be trying to instantiate a member of a class
16750 template or partial specialization. */
16755 /* In the case of a friend template whose definition is provided
16756 outside the class, we may have too many arguments. Drop the
16757 ones we don't need. The same is true for specializations. */
16758 args = get_innermost_template_args
16760 else
16765 else
16768 /* We may be in the middle of deferred access check. Disable it now. */
16771 /* Unless an explicit instantiation directive has already determined
16772 the linkage of D, remember that a definition is available for
16773 this entity. */
16781 /* If D is a member of an explicitly instantiated class template,
16782 and no definition is available, treat it like an implicit
16783 instantiation. */
16786 {
16790 }
16792 /* Recheck the substitutions to obtain any warning messages
16793 about ignoring cv qualifiers. Don't do this for artificial decls,
16794 as it breaks the context-sensitive substitution for lambda op(). */
16796 {
16800 /* Make sure that we can see identifiers, and compute access
16801 correctly. D is already the target FUNCTION_DECL with the
16802 right context. */
16806 {
16809 d);
16810 /* Don't simply tsubst the function type, as that will give
16811 duplicate warnings about poor parameter qualifications.
16812 The function arguments are the same as the decl_arguments
16813 without the top level cv qualifiers. */
16815 }
16819 }
16821 /* Defer all other templates, unless we have been explicitly
16822 forbidden from doing so. */
16824 template. */
16825 ! pattern_defined
16826 /* If it's OK to postpone instantiation, do so. */
16827 || defer_ok
16828 /* If this is a static data member that will be defined
16829 elsewhere, we don't want to instantiate the entire data
16830 member, but we do want to instantiate the initializer so that
16831 we can substitute that elsewhere. */
16833 {
16834 /* The definition of the static data member is now required so
16835 we must substitute the initializer. */
16839 {
16840 tree ns;
16841 tree init;
16847 args,
16852 LOOKUP_ONLYCONVERTING);
16855 }
16857 /* We restore the source position here because it's used by
16858 add_pending_template. */
16864 /* [temp.explicit]
16866 The definition of a non-exported function template, a
16867 non-exported member function template, or a non-exported
16868 member function or static data member of a class template
16869 shall be present in every translation unit in which it is
16870 explicitly instantiated. */
16874 /* ??? Historically, we have instantiated inline functions, even
16875 when marked as "extern template". */
16879 }
16880 /* Tell the repository that D is available in this translation unit
16881 -- and see if it is supposed to be instantiated here. */
16883 {
16884 /* In a PCH file, despite the fact that the repository hasn't
16885 requested instantiation in the PCH it is still possible that
16886 an instantiation will be required in a file that includes the
16887 PCH. */
16890 /* Instantiate inline functions so that the inliner can do its
16891 job, even though we'll not be emitting a copy of this
16892 function. */
16895 }
16901 /* Mark D as instantiated so that recursive calls to
16902 instantiate_decl do not try to instantiate it again. */
16905 /* Regenerate the declaration in case the template has been modified
16906 by a subsequent redeclaration. */
16909 /* We already set the file and line above. Reset them now in case
16910 they changed as a result of calling regenerate_decl_from_template. */
16914 {
16915 tree init;
16917 /* Clear out DECL_RTL; whatever was there before may not be right
16918 since we've reset the type of the declaration. */
16922 /* The initializer is placed in DECL_INITIAL by
16923 regenerate_decl_from_template. Pull it out so that
16924 cp_finish_decl can process it. */
16929 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16930 initializer. That function will defer actual emission until
16931 we have a chance to determine linkage. */
16934 /* Enter the scope of D so that access-checking works correctly. */
16938 }
16940 {
16941 htab_t saved_local_specializations;
16942 tree subst_decl;
16943 tree tmpl_parm;
16944 tree spec_parm;
16946 /* Save away the current list, in case we are instantiating one
16947 template from within the body of another. */
16950 /* Set up the list of local specializations. */
16952 hash_local_specialization,
16953 eq_local_specializations,
16954 NULL);
16956 /* Set up context. */
16959 /* Create substitution entries for the parameters. */
16964 {
16968 }
16970 {
16974 }
16976 {
16977 /* Register the (value) argument pack as a specialization of
16978 TMPL_PARM, then move on. */
16983 }
16986 /* Substitute into the body of the function. */
16991 /* Set the current input_location to the end of the function
16992 so that finish_function knows where we are. */
16995 /* We don't need the local specializations any more. */
16999 /* Finish the function. */
17002 }
17004 /* We're not deferring instantiation any more. */
17010 out:
17018 }
17020 /* Run through the list of templates that we wish we could
17021 instantiate, and instantiate any we can. RETRIES is the
17022 number of times we retry pending template instantiation. */
17024 void
17026 {
17030 /* Instantiating templates may trigger vtable generation. This in turn
17031 may require further template instantiations. We place a limit here
17032 to avoid infinite loop. */
17034 {
17038 " instantiating %q+D, possibly from virtual table generation"
17042 /* Pretend that we defined it. */
17045 }
17047 do
17048 {
17053 {
17058 {
17059 tree fn;
17062 {
17066 fn;
17074 }
17077 }
17078 else
17079 {
17082 {
17083 instantiation
17089 }
17093 }
17096 /* If INSTANTIATION has been instantiated, then we don't
17097 need to consider it again in the future. */
17099 else
17100 {
17103 }
17106 }
17108 }
17112 }
17114 /* Substitute ARGVEC into T, which is a list of initializers for
17115 either base class or a non-static data member. The TREE_PURPOSEs
17116 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17117 instantiate_decl. */
17119 static tree
17121 {
17125 {
17126 tree decl;
17127 tree init;
17133 {
17134 tree expr;
17135 tree arg;
17137 /* Expand the base class expansion type into separate base
17138 classes. */
17140 tf_warning_or_error,
17141 NULL_TREE);
17145 /* We'll be building separate TREE_LISTs of arguments for
17146 each base. */
17152 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17153 expand each argument in the TREE_VALUE of t. */
17159 /* VOID_TYPE_NODE is used to indicate
17160 value-initialization. */
17161 {
17164 }
17165 else
17166 {
17167 /* Substitute parameter packs into each argument in the
17168 TREE_LIST. */
17171 {
17172 tree expanded_exprs;
17174 /* Expand the argument. */
17176 expanded_exprs
17178 tf_warning_or_error,
17179 NULL_TREE);
17183 /* Prepend each of the expanded expressions to the
17184 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17186 {
17191 }
17192 }
17195 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17196 since we built them backwards. */
17198 {
17201 }
17202 }
17203 }
17206 {
17208 {
17212 }
17213 else
17214 {
17226 }
17229 {
17233 }
17234 }
17235 }
17237 }
17239 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17241 static void
17243 {
17248 else
17250 }
17252 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17253 is the instantiation (which should have been created with
17254 start_enum) and ARGS are the template arguments to use. */
17256 static void
17258 {
17259 tree e;
17262 {
17263 tree value;
17264 tree decl;
17267 /* Note that in a template enum, the TREE_VALUE is the
17268 CONST_DECL, not the corresponding INTEGER_CST. */
17273 /* Give this enumeration constant the correct access. */
17276 /* Actually build the enumerator itself. */
17278 }
17283 }
17285 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17286 its type -- but without substituting the innermost set of template
17287 arguments. So, innermost set of template parameters will appear in
17288 the type. */
17290 tree
17292 {
17293 tree fn_type;
17294 tree tmpl;
17295 tree targs;
17296 tree tparms;
17304 /* There should be as many levels of arguments as there are levels
17305 of parameters. */
17311 /* No substitution is necessary. */
17312 ;
17313 else
17314 {
17316 tree partial_args;
17318 /* Replace the innermost level of the TARGS with NULL_TREEs to
17319 let tsubst know not to substitute for those parameters. */
17328 /* Disable access control as this function is used only during
17329 name-mangling. */
17334 /* Now, do the (partial) substitution to figure out the
17335 appropriate function type. */
17339 /* Substitute into the template parameters to obtain the real
17340 innermost set of parameters. This step is important if the
17341 innermost set of template parameters contains value
17342 parameters whose types depend on outer template parameters. */
17347 }
17350 }
17352 /* Return truthvalue if we're processing a template different from
17353 the last one involved in diagnostics. */
17354 int
17356 {
17358 }
17360 /* Remember current template involved in diagnostics. */
17361 void
17363 {
17365 }
17369 {
17371 }
17373 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17374 type. Return zero for ok, nonzero for disallowed. Issue error and
17375 warning messages under control of COMPLAIN. */
17377 static int
17379 {
17394 }
17396 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17397 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17399 static bool
17401 {
17402 tree scope;
17404 /* [temp.dep.type]
17406 A type is dependent if it is:
17408 -- a template parameter. Template template parameters are types
17409 for us (since TYPE_P holds true for them) so we handle
17410 them here. */
17414 /* -- a qualified-id with a nested-name-specifier which contains a
17415 class-name that names a dependent type or whose unqualified-id
17416 names a dependent type. */
17419 /* -- a cv-qualified type where the cv-unqualified type is
17420 dependent. */
17422 /* -- a compound type constructed from any dependent type. */
17432 {
17433 tree arg_type;
17438 arg_type;
17443 }
17444 /* -- an array type constructed from any dependent type or whose
17445 size is specified by a constant expression that is
17446 value-dependent. */
17448 {
17453 }
17456 {
17457 /* If this is the TYPE_DOMAIN of an array type, consider it
17458 dependent. We already checked for value-dependence in
17459 compute_array_index_type. */
17461 }
17463 /* -- a template-id in which either the template name is a template
17464 parameter ... */
17467 /* ... or any of the template arguments is a dependent type or
17468 an expression that is type-dependent or value-dependent. */
17470 && (any_dependent_template_arguments_p
17474 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17475 argument of the `typeof' expression is not type-dependent, then
17476 it should already been have resolved. */
17481 /* A template argument pack is dependent if any of its packed
17482 arguments are. */
17484 {
17490 }
17492 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17493 be template parameters. */
17497 /* The standard does not specifically mention types that are local
17498 to template functions or local classes, but they should be
17499 considered dependent too. For example:
17501 template <int I> void f() {
17502 enum E { a = I };
17503 S<sizeof (E)> s;
17504 }
17506 The size of `E' cannot be known until the value of `I' has been
17507 determined. Therefore, `E' must be considered dependent. */
17514 /* Other types are non-dependent. */
17516 }
17518 /* Returns TRUE if TYPE is dependent, in the sense of
17519 [temp.dep.type]. */
17521 bool
17523 {
17524 /* If there are no template parameters in scope, then there can't be
17525 any dependent types. */
17527 {
17528 /* If we are not processing a template, then nobody should be
17529 providing us with a dependent type. */
17533 }
17535 /* If the type is NULL, we have not computed a type for the entity
17536 in question; in that case, the type is dependent. */
17540 /* Erroneous types can be considered non-dependent. */
17544 /* If we have not already computed the appropriate value for TYPE,
17545 do so now. */
17547 {
17550 }
17553 }
17555 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17556 lookup. In other words, a dependent type that is not the current
17557 instantiation. */
17559 bool
17561 {
17564 }
17566 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17567 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17568 expression. */
17570 bool
17572 {
17576 /* A name declared with a dependent type. */
17581 {
17583 /* A name that has not been looked up -- must be dependent. */
17587 /* A non-type template parm. */
17591 /* A non-type template parm. */
17597 /* A constant with integral or enumeration type and is initialized
17598 with an expression that is value-dependent. */
17610 /* These expressions are value-dependent if the type to which
17611 the cast occurs is dependent or the expression being casted
17612 is value-dependent. */
17613 {
17619 /* A functional cast has a list of operands. */
17622 {
17623 /* If there are no operands, it must be an expression such
17624 as "int()". This should not happen for aggregate types
17625 because it would form non-constant expressions. */
17629 }
17635 }
17639 /* A `sizeof' expression is value-dependent if the operand is
17640 type-dependent or is a pack expansion. */
17650 /* FIXME why check value-dependency? */
17655 {
17658 }
17665 /* A CALL_EXPR may appear in a constant expression if it is a
17666 call to a builtin function, e.g., __builtin_constant_p. All
17667 such calls are value-dependent. */
17671 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17672 is value-dependent. */
17673 {
17682 }
17685 {
17689 }
17696 {
17700 }
17703 /* A constant expression is value-dependent if any subexpression is
17704 value-dependent. */
17706 {
17716 || (value_dependent_expression_p
17721 {
17724 /* In some cases, some of the operands may be missing.
17725 (For example, in the case of PREDECREMENT_EXPR, the
17726 amount to increment by may be missing.) That doesn't
17727 make the expression dependent. */
17729 && (value_dependent_expression_p
17733 }
17737 }
17738 }
17740 /* The expression is not value-dependent. */
17742 }
17744 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17745 [temp.dep.expr]. */
17747 bool
17749 {
17756 /* An unresolved name is always dependent. */
17761 /* Some expression forms are never type-dependent. */
17773 /* The types of these expressions depends only on the type to which
17774 the cast occurs. */
17782 /* The types of these expressions depends only on the type created
17783 by the expression. */
17786 {
17787 /* For NEW_EXPR tree nodes created inside a template, either
17788 the object type itself or a TREE_LIST may appear as the
17789 operand 1. */
17792 /* This is an array type. We need to check array dimensions
17793 as well. */
17795 || value_dependent_expression_p
17797 else
17799 }
17802 {
17806 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
17807 contains an identifier associated by name lookup with one or more
17808 declarations declared with a dependent type, or...a
17809 nested-name-specifier or qualified-id that names a member of an
17810 unknown specialization. */
17813 }
17818 && (any_dependent_template_arguments_p
17830 {
17831 tree elt;
17835 {
17838 }
17840 }
17842 /* A static data member of the current instantiation with incomplete
17843 array type is type-dependent, as the definition and specializations
17844 can have different bounds. */
17852 {
17857 {
17863 }
17864 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17872 {
17877 }
17882 {
17886 }
17888 }
17893 }
17895 /* Like type_dependent_expression_p, but it also works while not processing
17896 a template definition, i.e. during substitution or mangling. */
17898 bool
17900 {
17906 }
17908 /* Returns TRUE if ARGS contains a type-dependent expression. */
17910 bool
17912 {
17914 tree arg;
17917 {
17920 }
17922 }
17924 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17925 expressions) contains any value-dependent expressions. */
17927 bool
17929 {
17935 }
17937 /* Returns TRUE if the ARG (a template argument) is dependent. */
17939 bool
17941 {
17949 {
17953 {
17956 }
17959 }
17962 else
17965 }
17967 /* Returns true if ARGS (a collection of template arguments) contains
17968 any types that require structural equality testing. */
17970 bool
17972 {
17982 {
17985 {
17991 {
17992 /* Look inside the argument pack. */
17995 }
17998 {
18012 }
18013 }
18014 }
18017 }
18019 /* Returns true if ARGS (a collection of template arguments) contains
18020 any dependent arguments. */
18022 bool
18024 {
18034 {
18039 }
18042 }
18044 /* Returns TRUE if the template TMPL is dependent. */
18046 bool
18048 {
18050 {
18052 {
18056 }
18058 }
18060 /* Template template parameters are dependent. */
18064 /* So are names that have not been looked up. */
18068 /* So are member templates of dependent classes. */
18072 }
18074 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18076 bool
18078 {
18081 }
18083 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18084 is dependent. */
18086 bool
18088 {
18095 {
18116 {
18120 }
18124 {
18128 {
18133 }
18134 }
18135 }
18138 }
18140 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18141 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18142 no such TYPE can be found. Note that this function peers inside
18143 uninstantiated templates and therefore should be used only in
18144 extremely limited situations. ONLY_CURRENT_P restricts this
18145 peering to the currently open classes hierarchy (which is required
18146 when comparing types). */
18148 tree
18150 {
18151 tree scope;
18152 tree name;
18153 tree decl;
18155 tree pushed_scope;
18156 tree result;
18161 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18162 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18163 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18164 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18165 identifier of the TYPENAME_TYPE anymore.
18166 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18167 TYPENAME_TYPE instead, we avoid messing up with a possible
18168 typedef variant case. */
18171 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18172 it first before we can figure out what NAME refers to. */
18175 /* If we don't know what SCOPE refers to, then we cannot resolve the
18176 TYPENAME_TYPE. */
18179 /* If the SCOPE is a template type parameter, we have no way of
18180 resolving the name. */
18183 /* If the SCOPE is not the current instantiation, there's no reason
18184 to look inside it. */
18187 /* If this is a typedef, we don't want to look inside (c++/11987). */
18190 /* If SCOPE isn't the template itself, it will not have a valid
18191 TYPE_FIELDS list. */
18193 /* scope is either the template itself or a compatible instantiation
18194 like X<T>, so look up the name in the original template. */
18196 else
18197 /* scope is a partial instantiation, so we can't do the lookup or we
18198 will lose the template arguments. */
18200 /* Enter the SCOPE so that name lookup will be resolved as if we
18201 were in the class definition. In particular, SCOPE will no
18202 longer be considered a dependent type. */
18204 /* Look up the declaration. */
18209 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18210 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18215 {
18219 }
18222 {
18223 tree tmpl;
18224 tree args;
18225 /* Obtain the template and the arguments. */
18228 /* Instantiate the template. */
18234 }
18236 /* Leave the SCOPE. */
18240 /* If we failed to resolve it, return the original typename. */
18244 /* If lookup found a typename type, resolve that too. */
18246 {
18247 /* Ill-formed programs can cause infinite recursion here, so we
18248 must catch that. */
18252 }
18254 /* Qualify the resulting type. */
18260 }
18262 /* EXPR is an expression which is not type-dependent. Return a proxy
18263 for EXPR that can be used to compute the types of larger
18264 expressions containing EXPR. */
18266 tree
18268 {
18269 tree inner_expr;
18271 /* Preserve null pointer constants so that the type of things like
18272 "p == 0" where "p" is a pointer can be determined. */
18275 /* Preserve OVERLOADs; the functions must be available to resolve
18276 types. */
18287 /* There is no need to return a proxy for a variable. */
18290 /* Preserve string constants; conversions from string constants to
18291 "char *" are allowed, even though normally a "const char *"
18292 cannot be used to initialize a "char *". */
18295 /* Preserve arithmetic constants, as an optimization -- there is no
18296 reason to create a new node. */
18299 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18300 There is at least one place where we want to know that a
18301 particular expression is a throw-expression: when checking a ?:
18302 expression, there are special rules if the second or third
18303 argument is a throw-expression. */
18322 /* If the type is unknown, it can't really be non-dependent */
18325 /* Otherwise, build a NON_DEPENDENT_EXPR.
18327 REFERENCE_TYPEs are not stripped for expressions in templates
18328 because doing so would play havoc with mangling. Consider, for
18329 example:
18331 template <typename T> void f<T& g>() { g(); }
18333 In the body of "f", the expression for "g" will have
18334 REFERENCE_TYPE, even though the standard says that it should
18335 not. The reason is that we must preserve the syntactic form of
18336 the expression so that mangling (say) "f<g>" inside the body of
18337 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18338 stripped here. */
18340 }
18342 /* ARGS is a vector of expressions as arguments to a function call.
18343 Replace the arguments with equivalent non-dependent expressions.
18344 This modifies ARGS in place. */
18346 void
18348 {
18350 tree arg;
18353 {
18357 }
18358 }
18360 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18361 with a level one deeper than the actual template parms. */
18363 tree
18365 {
18378 }
18380 /* Given type ARG, return std::initializer_list<ARG>. */
18382 static tree
18384 {
18385 tree std_init_list = namespace_binding
18387 tree argvec;
18389 {
18393 }
18398 }
18400 /* Replace auto in TYPE with std::initializer_list<auto>. */
18402 static tree
18404 {
18411 }
18413 /* walk_tree helper for do_auto_deduction. */
18415 static tree
18418 {
18419 /* Is this a variable with the type we're looking for? */
18423 else
18425 }
18427 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18428 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18430 tree
18432 {
18435 tree decl;
18438 /* The name of the object being declared shall not appear in the
18439 initializer expression. */
18442 {
18446 }
18448 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18449 with either a new invented type template parameter U or, if the
18450 initializer is a braced-init-list (8.5.4), with
18451 std::initializer_list<U>. */
18464 {
18467 }
18469 /* If the list of declarators contains more than one declarator, the type
18470 of each declared variable is determined as described above. If the
18471 type deduced for the template parameter U is not the same in each
18472 deduction, the program is ill-formed. */
18475 {
18479 }
18485 }
18487 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18488 result. */
18490 tree
18492 {
18493 tree argvec;
18502 }
18504 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18506 bool
18508 {
18512 else
18514 }
18516 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18517 appear as a type-specifier for the declaration in question, we don't
18518 have to look through the whole type. */
18520 tree
18522 {
18539 }
18541 /* For a given template T, return the vector of typedefs referenced
18542 in T for which access check is needed at T instantiation time.
18543 T is either a FUNCTION_DECL or a RECORD_TYPE.
18544 Those typedefs were added to T by the function
18545 append_type_to_template_for_access_check. */
18549 {
18550 tree ti;
18561 {
18566 }
18569 }
18571 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18572 tied to T. That list of typedefs will be access checked at
18573 T instantiation time.
18574 T is either a FUNCTION_DECL or a RECORD_TYPE.
18575 TYPE_DECL is a TYPE_DECL node representing a typedef.
18576 SCOPE is the scope through which TYPE_DECL is accessed.
18577 LOCATION is the location of the usage point of TYPE_DECL.
18579 This function is a subroutine of
18580 append_type_to_template_for_access_check. */
18582 static void
18584 tree type_decl,
18585 tree scope,
18586 location_t location)
18587 {
18588 qualified_typedef_usage_t typedef_usage;
18589 tree ti;
18596 && type_decl
18612 }
18614 /* Append TYPE_DECL to the template TEMPL.
18615 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18616 At TEMPL instanciation time, TYPE_DECL will be checked to see
18617 if it can be accessed through SCOPE.
18618 LOCATION is the location of the usage point of TYPE_DECL.
18620 e.g. consider the following code snippet:
18622 class C
18623 {
18624 typedef int myint;
18625 };
18627 template<class U> struct S
18628 {
18629 C::myint mi; // <-- usage point of the typedef C::myint
18630 };
18632 S<char> s;
18634 At S<char> instantiation time, we need to check the access of C::myint
18635 In other words, we need to check the access of the myint typedef through
18636 the C scope. For that purpose, this function will add the myint typedef
18637 and the scope C through which its being accessed to a list of typedefs
18638 tied to the template S. That list will be walked at template instantiation
18639 time and access check performed on each typedefs it contains.
18640 Note that this particular code snippet should yield an error because
18641 myint is private to C. */
18643 void
18645 tree type_decl,
18646 tree scope,
18647 location_t location)
18648 {
18654 /* Make sure we don't append the type to the template twice. */
18665 }
18667 /* Set up the hash tables for template instantiations. */
18669 void
18671 {
18673 hash_specialization,
18674 eq_specializations,
18675 ggc_free);
18677 hash_specialization,
18678 eq_specializations,
18679 ggc_free);
18680 }
18682 /* Print stats about the template hash tables for -fstats. */
18684 void
18686 {
18695 }