| blob | 5a90bdc6eadf7cd119debf046b13a722c180932b |
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 static 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 complain,
4831 }
4833 }
4835 tree
4837 {
4839 }
4841 /* EXPR is an expression which is used in a constant-expression context.
4842 For instance, it could be a VAR_DECL with a constant initializer.
4843 Extract the innermost constant expression.
4845 This is basically a more powerful version of
4846 integral_constant_value, which can be used also in templates where
4847 initializers can maintain a syntactic rather than semantic form
4848 (even if they are non-dependent, for access-checking purposes). */
4850 static tree
4852 {
4854 do
4855 {
4858 }
4862 }
4864 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4865 must be a function or a pointer-to-function type, as specified
4866 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4867 and check that the resulting function has external linkage. */
4869 static tree
4871 {
4885 /* [temp.arg.nontype]/1
4887 A template-argument for a non-type, non-template template-parameter
4888 shall be one of:
4889 [...]
4890 -- the address of an object or function with external linkage. */
4892 {
4897 }
4900 }
4902 /* Subroutine of convert_nontype_argument.
4903 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4904 Emit an error otherwise. */
4906 static bool
4908 {
4916 }
4918 /* Returns TRUE iff the address of OP is value-dependent.
4920 14.6.2.4 [temp.dep.temp]:
4921 A non-integral non-type template-argument is dependent if its type is
4922 dependent or it has either of the following forms
4923 qualified-id
4924 & qualified-id
4925 and contains a nested-name-specifier which specifies a class-name that
4926 names a dependent type.
4928 We generalize this to just say that the address of a member of a
4929 dependent class is value-dependent; the above doesn't cover the
4930 address of a static data member named with an unqualified-id. */
4932 static bool
4934 {
4935 /* We could use get_inner_reference here, but there's no need;
4936 this is only relevant for template non-type arguments, which
4937 can only be expressed as &id-expression. */
4939 {
4943 }
4946 }
4948 /* Attempt to convert the non-type template parameter EXPR to the
4949 indicated TYPE. If the conversion is successful, return the
4950 converted value. If the conversion is unsuccessful, return
4951 NULL_TREE if we issued an error message, or error_mark_node if we
4952 did not. We issue error messages for out-and-out bad template
4953 parameters, but not simply because the conversion failed, since we
4954 might be just trying to do argument deduction. Both TYPE and EXPR
4955 must be non-dependent.
4957 The conversion follows the special rules described in
4958 [temp.arg.nontype], and it is much more strict than an implicit
4959 conversion.
4961 This function is called twice for each template argument (see
4962 lookup_template_class for a more accurate description of this
4963 problem). This means that we need to handle expressions which
4964 are not valid in a C++ source, but can be created from the
4965 first call (for instance, casts to perform conversions). These
4966 hacks can go away after we fix the double coercion problem. */
4968 static tree
4970 {
4971 tree expr_type;
4973 /* Detect immediately string literals as invalid non-type argument.
4974 This special-case is not needed for correctness (we would easily
4975 catch this later), but only to provide better diagnostic for this
4976 common user mistake. As suggested by DR 100, we do not mention
4977 linkage issues in the diagnostic as this is not the point. */
4978 /* FIXME we're making this OK. */
4980 {
4986 }
4988 /* Add the ADDR_EXPR now for the benefit of
4989 value_dependent_expression_p. */
4993 /* If we are in a template, EXPR may be non-dependent, but still
4994 have a syntactic, rather than semantic, form. For example, EXPR
4995 might be a SCOPE_REF, rather than the VAR_DECL to which the
4996 SCOPE_REF refers. Preserving the qualifying scope is necessary
4997 so that access checking can be performed when the template is
4998 instantiated -- but here we need the resolved form so that we can
4999 convert the argument. */
5010 else
5013 /* HACK: Due to double coercion, we can get a
5014 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5015 which is the tree that we built on the first call (see
5016 below when coercing to reference to object or to reference to
5017 function). We just strip everything and get to the arg.
5018 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5019 for examples. */
5021 {
5023 {
5024 /* ??? Maybe we could use convert_from_reference here, but we
5025 would need to relax its constraints because the NOP_EXPR
5026 could actually change the type to something more cv-qualified,
5027 and this is not folded by convert_from_reference. */
5038 }
5040 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5041 parameter is a pointer to object, through decay and
5042 qualification conversion. Let's strip everything. */
5044 {
5048 /* Skip the ADDR_EXPR only if it is part of the decay for
5049 an array. Otherwise, it is part of the original argument
5050 in the source code. */
5054 }
5055 }
5057 /* [temp.arg.nontype]/5, bullet 1
5059 For a non-type template-parameter of integral or enumeration type,
5060 integral promotions (_conv.prom_) and integral conversions
5061 (_conv.integral_) are applied. */
5063 {
5068 /* Notice that there are constant expressions like '4 % 0' which
5069 do not fold into integer constants. */
5071 {
5076 }
5078 /* At this point, an implicit conversion does what we want,
5079 because we already know that the expression is of integral
5080 type. */
5085 /* Conversion was allowed: fold it to a bare integer constant. */
5087 }
5088 /* [temp.arg.nontype]/5, bullet 2
5090 For a non-type template-parameter of type pointer to object,
5091 qualification conversions (_conv.qual_) and the array-to-pointer
5092 conversion (_conv.array_) are applied. */
5094 {
5095 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5097 A template-argument for a non-type, non-template template-parameter
5098 shall be one of: [...]
5100 -- the name of a non-type template-parameter;
5101 -- the address of an object or function with external linkage, [...]
5102 expressed as "& id-expression" where the & is optional if the name
5103 refers to a function or array, or if the corresponding
5104 template-parameter is a reference.
5106 Here, we do not care about functions, as they are invalid anyway
5107 for a parameter of type pointer-to-object. */
5110 /* Non-type template parameters are OK. */
5111 ;
5114 {
5116 {
5118 "because %qD is a variable, not the address of "
5122 }
5123 /* Other values, like integer constants, might be valid
5124 non-type arguments of some other type. */
5126 }
5127 else
5128 {
5129 tree decl;
5134 {
5139 }
5141 {
5146 }
5147 }
5156 }
5157 /* [temp.arg.nontype]/5, bullet 3
5159 For a non-type template-parameter of type reference to object, no
5160 conversions apply. The type referred to by the reference may be more
5161 cv-qualified than the (otherwise identical) type of the
5162 template-argument. The template-parameter is bound directly to the
5163 template-argument, which must be an lvalue. */
5165 {
5167 expr_type))
5171 {
5175 }
5178 {
5182 }
5184 /* [temp.arg.nontype]/1
5186 A template-argument for a non-type, non-template template-parameter
5187 shall be one of: [...]
5189 -- the address of an object or function with external linkage. */
5192 {
5195 {
5197 "because a reference variable does not have a constant "
5200 }
5201 }
5204 {
5209 }
5212 {
5217 }
5220 }
5221 /* [temp.arg.nontype]/5, bullet 4
5223 For a non-type template-parameter of type pointer to function, only
5224 the function-to-pointer conversion (_conv.func_) is applied. If the
5225 template-argument represents a set of overloaded functions (or a
5226 pointer to such), the matching function is selected from the set
5227 (_over.over_). */
5229 {
5230 /* If the argument is a template-id, we might not have enough
5231 context information to decay the pointer. */
5233 {
5237 }
5244 {
5248 }
5249 }
5250 /* [temp.arg.nontype]/5, bullet 5
5252 For a non-type template-parameter of type reference to function, no
5253 conversions apply. If the template-argument represents a set of
5254 overloaded functions, the matching function is selected from the set
5255 (_over.over_). */
5257 {
5259 {
5264 }
5271 }
5272 /* [temp.arg.nontype]/5, bullet 6
5274 For a non-type template-parameter of type pointer to member function,
5275 no conversions apply. If the template-argument represents a set of
5276 overloaded member functions, the matching member function is selected
5277 from the set (_over.over_). */
5279 {
5284 /* [temp.arg.nontype] bullet 1 says the pointer to member
5285 expression must be a pointer-to-member constant. */
5289 /* There is no way to disable standard conversions in
5290 resolve_address_of_overloaded_function (called by
5291 instantiate_type). It is possible that the call succeeded by
5292 converting &B::I to &D::I (where B is a base of D), so we need
5293 to reject this conversion here.
5295 Actually, even if there was a way to disable standard conversions,
5296 it would still be better to reject them here so that we can
5297 provide a superior diagnostic. */
5299 {
5303 /* If we are just one standard conversion off, explain. */
5308 }
5309 }
5310 /* [temp.arg.nontype]/5, bullet 7
5312 For a non-type template-parameter of type pointer to data member,
5313 qualification conversions (_conv.qual_) are applied. */
5315 {
5316 /* [temp.arg.nontype] bullet 1 says the pointer to member
5317 expression must be a pointer-to-member constant. */
5324 }
5325 /* A template non-type parameter must be one of the above. */
5326 else
5329 /* Sanity check: did we actually convert the argument to the
5330 right type? */
5334 }
5336 /* Subroutine of coerce_template_template_parms, which returns 1 if
5337 PARM_PARM and ARG_PARM match using the rule for the template
5338 parameters of template template parameters. Both PARM and ARG are
5339 template parameters; the rest of the arguments are the same as for
5340 coerce_template_template_parms.
5341 */
5342 static int
5344 tree arg,
5345 tsubst_flags_t complain,
5346 tree in_decl,
5347 tree outer_args)
5348 {
5357 {
5359 /* We encounter instantiations of templates like
5360 template <template <template <class> class> class TT>
5361 class C; */
5362 {
5369 }
5370 /* Fall through. */
5375 /* Argument is a parameter pack but parameter is not. */
5380 /* The tsubst call is used to handle cases such as
5382 template <int> class C {};
5383 template <class T, template <T> class TT> class D {};
5384 D<int, C> d;
5386 i.e. the parameter list of TT depends on earlier parameters. */
5388 && !same_type_p
5395 /* Argument is a parameter pack but parameter is not. */
5402 }
5405 }
5408 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5409 template template parameters. Both PARM_PARMS and ARG_PARMS are
5410 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5411 or PARM_DECL.
5413 Consider the example:
5414 template <class T> class A;
5415 template<template <class U> class TT> class B;
5417 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5418 the parameters to A, and OUTER_ARGS contains A. */
5420 static int
5422 tree arg_parms,
5423 tsubst_flags_t complain,
5424 tree in_decl,
5425 tree outer_args)
5426 {
5437 /* Determine whether we have a parameter pack at the end of the
5438 template template parameter's template parameter list. */
5440 {
5447 {
5461 }
5462 }
5468 /* Check all of the template parameters except the parameter pack at
5469 the end (if any). */
5471 {
5480 outer_args))
5483 }
5486 {
5487 /* Check each of the template parameters in the template
5488 argument against the template parameter pack at the end of
5489 the template template parameter. */
5496 {
5503 outer_args))
5505 }
5506 }
5509 }
5511 /* Verifies that the deduced template arguments (in TARGS) for the
5512 template template parameters (in TPARMS) represent valid bindings,
5513 by comparing the template parameter list of each template argument
5514 to the template parameter list of its corresponding template
5515 template parameter, in accordance with DR150. This
5516 routine can only be called after all template arguments have been
5517 deduced. It will return TRUE if all of the template template
5518 parameter bindings are okay, FALSE otherwise. */
5519 bool
5521 {
5525 /* We're dealing with template parms in this process. */
5531 {
5536 {
5541 {
5542 /* Look inside the argument pack. */
5545 }
5548 {
5552 /* Extract the next argument from the argument
5553 pack. */
5557 /* Look at the pattern of the pack expansion. */
5560 /* Extract the template parameters from the template
5561 argument. */
5567 /* Verify that we can coerce the template template
5568 parameters from the template argument to the template
5569 parameter. This requires an exact match. */
5571 && !coerce_template_template_parms
5573 targ_parms,
5574 tf_none,
5575 tparm,
5576 targs))
5577 {
5580 }
5581 }
5582 }
5583 }
5585 out:
5589 }
5591 /* Convert the indicated template ARG as necessary to match the
5592 indicated template PARM. Returns the converted ARG, or
5593 error_mark_node if the conversion was unsuccessful. Error and
5594 warning messages are issued under control of COMPLAIN. This
5595 conversion is for the Ith parameter in the parameter list. ARGS is
5596 the full set of template arguments deduced so far. */
5598 static tree
5600 tree arg,
5601 tree args,
5602 tsubst_flags_t complain,
5604 tree in_decl)
5605 {
5606 tree orig_arg;
5607 tree val;
5612 {
5613 /* The template argument was the name of some
5614 member function. That's usually
5615 invalid, but static members are OK. In any
5616 case, grab the underlying fields/functions
5617 and issue an error later if required. */
5620 }
5628 /* When determining whether an argument pack expansion is a template,
5629 look at the pattern. */
5633 /* Deal with an injected-class-name used as a template template arg. */
5635 {
5638 {
5646 }
5647 }
5649 is_tmpl_type =
5664 {
5670 typename_type,
5674 }
5676 {
5678 {
5680 {
5690 else
5692 }
5693 }
5695 }
5697 {
5699 {
5705 else
5707 }
5709 }
5712 {
5714 {
5716 /* The number of argument required is not known yet.
5717 Just accept it for now. */
5719 else
5720 {
5722 tree argparm;
5728 args))
5729 {
5732 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5733 TEMPLATE_DECL. */
5735 {
5740 }
5741 }
5742 else
5743 {
5745 {
5751 }
5754 }
5755 }
5756 }
5757 else
5759 /* We only form one instance of each template specialization.
5760 Therefore, if we use a non-canonical variant (i.e., a
5761 typedef), any future messages referring to the type will use
5762 the typedef, which is confusing if those future uses do not
5763 themselves also use the typedef. */
5766 }
5767 else
5768 {
5775 {
5778 else
5779 {
5780 /* Not sure if this is reachable, but it doesn't hurt
5781 to be robust. */
5784 }
5785 }
5787 /* We used to call digest_init here. However, digest_init
5788 will report errors, which we don't want when complain
5789 is zero. More importantly, digest_init will try too
5790 hard to convert things: for example, `0' should not be
5791 converted to pointer type at this point according to
5792 the standard. Accepting this is not merely an
5793 extension, since deciding whether or not these
5794 conversions can occur is part of determining which
5795 function template to call, or whether a given explicit
5796 argument specification is valid. */
5798 else
5807 {
5808 /* Strip typedefs from the SCOPE_REF. */
5813 }
5814 }
5817 }
5819 /* Coerces the remaining template arguments in INNER_ARGS (from
5820 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5821 Returns the coerced argument pack. PARM_IDX is the position of this
5822 parameter in the template parameter list. ARGS is the original
5823 template argument list. */
5824 static tree
5827 tree args,
5828 tree inner_args,
5830 tree new_args,
5832 tree in_decl,
5833 tsubst_flags_t complain)
5834 {
5837 tree packed_args;
5838 tree argument_pack;
5848 {
5849 /* When the template parameter is a non-type template
5850 parameter pack whose type uses parameter packs, we need
5851 to look at each of the template arguments
5852 separately. Build a vector of the types for these
5853 non-type template parameters in PACKED_TYPES. */
5854 tree expansion
5862 /* Check that we have the right number of arguments. */
5866 {
5867 int needed_parms
5872 }
5874 /* If we aren't able to check the actual arguments now
5875 (because they haven't been expanded yet), we can at least
5876 verify that all of the types used for the non-type
5877 template parameter pack are, in fact, valid for non-type
5878 template parameters. */
5881 {
5884 {
5888 }
5889 }
5890 }
5892 /* Convert the remaining arguments, which will be a part of the
5893 parameter pack "parm". */
5895 {
5900 {
5901 /* When we have a vector of types (corresponding to the
5902 non-type template parameter pack that uses parameter
5903 packs in its type, as mention above), and the
5904 argument is not an expansion (which expands to a
5905 currently unknown number of arguments), clone the
5906 parm and give it the next type in PACKED_TYPES. */
5910 }
5915 in_decl);
5919 }
5924 else
5925 {
5930 }
5933 #ifdef ENABLE_CHECKING
5936 #endif
5938 }
5940 /* Convert all template arguments to their appropriate types, and
5941 return a vector containing the innermost resulting template
5942 arguments. If any error occurs, return error_mark_node. Error and
5943 warning messages are issued under control of COMPLAIN.
5945 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5946 for arguments not specified in ARGS. Otherwise, if
5947 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5948 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5949 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5950 ARGS. */
5952 static tree
5954 tree args,
5955 tree in_decl,
5956 tsubst_flags_t complain,
5959 {
5961 tree inner_args;
5962 tree new_args;
5963 tree new_inner_args;
5967 /* When used as a boolean value, indicates whether this is a
5968 variadic template parameter list. Since it's an int, we can also
5969 subtract it from nparms to get the number of non-variadic
5970 parameters. */
5975 /* Determine if there are any parameter packs. */
5977 {
5981 }
5984 /* If there are 0 or 1 parameter packs, we need to expand any argument
5985 packs so that we can deduce a parameter pack from some non-packed args
5986 followed by an argument pack, as in variadic85.C. If there are more
5987 than that, we need to leave argument packs intact so the arguments are
5988 assigned to the right parameter packs. This should only happen when
5989 dealing with a nested class inside a partial specialization of a class
5990 template, as in variadic92.C. */
5997 && require_all_args
5998 && (!use_default_args
6001 {
6003 {
6005 {
6009 }
6010 else
6016 }
6019 }
6021 /* We need to evaluate the template arguments, even though this
6022 template-id may be nested within a "sizeof". */
6030 {
6031 tree arg;
6032 tree parm;
6034 /* Get the Ith template parameter. */
6038 {
6041 }
6043 /* Calculate the next argument. */
6046 else
6051 {
6052 /* All remaining arguments will be placed in the
6053 template parameter pack PARM. */
6059 /* Store this argument. */
6061 lost++;
6064 /* We are done with all of the arguments. */
6068 }
6070 {
6072 {
6074 {
6075 /* FIXME this restriction was removed by N2555; see
6076 bug 35722. */
6077 /* If ARG is a pack expansion, but PARM is not a
6078 template parameter pack (if it were, we would have
6079 handled it above), we're trying to expand into a
6080 fixed-length argument list. */
6084 else
6087 }
6089 }
6090 }
6092 {
6093 /* There must be a default arg in this case. */
6096 /* The position of the first default template argument,
6097 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6098 Record that. */
6101 }
6102 else
6106 {
6109 }
6111 /* This only occurs if there was an error in the template
6112 parameter list itself (which we would already have
6113 reported) that we are trying to recover from, e.g., a class
6114 template with a parameter list such as
6115 template<typename..., typename>. */
6117 else
6123 lost++;
6125 }
6132 #ifdef ENABLE_CHECKING
6136 #endif
6139 }
6141 /* Returns 1 if template args OT and NT are equivalent. */
6143 static int
6145 {
6150 /* For member templates */
6157 {
6174 }
6176 {
6177 /* We get here probably because we are in the middle of substituting
6178 into the pattern of a pack expansion. In that case the
6179 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6180 interested in. So we want to use the initial pack argument for
6181 the comparison. */
6186 }
6191 else
6193 }
6195 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6196 of template arguments. Returns 0 otherwise. */
6198 int
6200 {
6207 {
6213 }
6215 }
6217 static void
6219 {
6229 /* We are called both from instantiate_decl, where we've already had a
6230 tinst_level pushed, and instantiate_template, where we haven't.
6231 Compensate. */
6242 else
6251 }
6254 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6255 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6256 documentation for TEMPLATE_ID_EXPR. */
6258 tree
6260 {
6261 tree type;
6271 {
6273 unknown_type_node,
6275 arglist);
6277 }
6284 }
6286 /* Within the scope of a template class S<T>, the name S gets bound
6287 (in build_self_reference) to a TYPE_DECL for the class, not a
6288 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6289 or one of its enclosing classes, and that type is a template,
6290 return the associated TEMPLATE_DECL. Otherwise, the original
6291 DECL is returned.
6293 Also handle the case when DECL is a TREE_LIST of ambiguous
6294 injected-class-names from different bases. */
6296 tree
6298 {
6302 /* DR 176: A lookup that finds an injected-class-name (10.2
6303 [class.member.lookup]) can result in an ambiguity in certain cases
6304 (for example, if it is found in more than one base class). If all of
6305 the injected-class-names that are found refer to specializations of
6306 the same class template, and if the name is followed by a
6307 template-argument-list, the reference refers to the class template
6308 itself and not a specialization thereof, and is not ambiguous. */
6310 {
6313 {
6319 }
6322 else
6324 }
6330 }
6332 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6333 parameters, find the desired type.
6335 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6337 IN_DECL, if non-NULL, is the template declaration we are trying to
6338 instantiate.
6340 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6341 the class we are looking up.
6343 Issue error and warning messages under control of COMPLAIN.
6345 If the template class is really a local class in a template
6346 function, then the FUNCTION_CONTEXT is the function in which it is
6347 being instantiated.
6349 ??? Note that this function is currently called *twice* for each
6350 template-id: the first time from the parser, while creating the
6351 incomplete type (finish_template_type), and the second type during the
6352 real instantiation (instantiate_template_class). This is surely something
6353 that we want to avoid. It also causes some problems with argument
6354 coercion (see convert_nontype_argument for more information on this). */
6356 tree
6358 tree arglist,
6359 tree in_decl,
6360 tree context,
6362 tsubst_flags_t complain)
6363 {
6365 tree t;
6368 spec_entry elt;
6369 hashval_t hash;
6374 {
6378 else
6379 {
6386 }
6389 }
6391 {
6394 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6395 an implicit typename for the second A. Deal with it. */
6400 {
6403 }
6404 }
6407 {
6410 }
6414 {
6418 }
6420 /* Issue an error message if we didn't find a template. */
6422 {
6426 }
6429 /* Make sure it's a user visible template, if it was named by
6430 the user. */
6433 {
6435 {
6439 }
6441 }
6446 {
6447 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6448 template arguments */
6450 tree parm;
6451 tree arglist2;
6452 tree outer;
6456 /* Consider an example where a template template parameter declared as
6458 template <class T, class U = std::allocator<T> > class TT
6460 The template parameter level of T and U are one level larger than
6461 of TT. To proper process the default argument of U, say when an
6462 instantiation `TT<int>' is seen, we need to build the full
6463 arguments containing {int} as the innermost level. Outer levels,
6464 available when not appearing as default template argument, can be
6465 obtained from the arguments of the enclosing template.
6467 Suppose that TT is later substituted with std::vector. The above
6468 instantiation is `TT<int, std::allocator<T> >' with TT at
6469 level 1, and T at level 2, while the template arguments at level 1
6470 becomes {std::vector} and the inner level 2 is {int}. */
6476 /* This is an argument of the current template, so we haven't set
6477 DECL_CONTEXT yet. */
6484 complain,
6494 }
6495 else
6496 {
6498 tree gen_tmpl;
6499 tree type_decl;
6512 {
6513 /* We've been given an incomplete set of template arguments.
6514 For example, given:
6516 template <class T> struct S1 {
6517 template <class U> struct S2 {};
6518 template <class U> struct S2<U*> {};
6519 };
6521 we will be called with an ARGLIST of `U*', but the
6522 TEMPLATE will be `template <class T> template
6523 <class U> struct S1<T>::S2'. We must fill in the missing
6524 arguments. */
6525 arglist
6527 arglist);
6529 }
6531 /* Now we should have enough arguments. */
6534 /* From here on, we're only interested in the most general
6535 template. */
6537 /* Calculate the BOUND_ARGS. These will be the args that are
6538 actually tsubst'd into the definition to create the
6539 instantiation. */
6541 {
6542 /* We have multiple levels of arguments to coerce, at once. */
6552 {
6553 tree a;
6557 complain,
6560 else
6561 /* Outer levels should have already been coerced. */
6564 /* Don't process further if one of the levels fails. */
6566 {
6567 /* Restore the ARGLIST to its full size. */
6570 }
6574 /* We temporarily reduce the length of the ARGLIST so
6575 that coerce_template_parms will see only the arguments
6576 corresponding to the template parameters it is
6577 examining. */
6579 }
6581 /* Restore the ARGLIST to its full size. */
6585 }
6586 else
6587 arglist
6590 gen_tmpl,
6591 complain,
6596 /* We were unable to bind the arguments. */
6599 /* In the scope of a template class, explicit references to the
6600 template class refer to the type of the template, not any
6601 instantiation of it. For example, in:
6603 template <class T> class C { void f(C<T>); }
6605 the `C<T>' is just the same as `C'. Outside of the
6606 class, however, such a reference is an instantiation. */
6610 /* comp_template_args is expensive, check it last. */
6612 arglist))
6615 /* If we already have this specialization, return it. */
6627 /* If the deduced arguments are invalid, then the binding
6628 failed. */
6632 complain))
6639 {
6644 }
6651 /* Create the type. */
6653 {
6655 {
6661 }
6662 else
6663 {
6664 /* We don't want to call start_enum for this type, since
6665 the values for the enumeration constants may involve
6666 template parameters. And, no one should be interested
6667 in the enumeration constants for such a type. */
6670 }
6671 }
6672 else
6673 {
6680 /* A local class. Make sure the decl gets registered properly. */
6685 /* This instantiation is another name for the primary
6686 template type. Set the TYPE_CANONICAL field
6687 appropriately. */
6690 /* Some of the template arguments require structural
6691 equality testing, so this template class requires
6692 structural equality testing. */
6694 }
6696 /* If we called start_enum or pushtag above, this information
6697 will already be set up. */
6699 {
6706 }
6707 else
6715 {
6718 }
6720 /* Let's consider the explicit specialization of a member
6721 of a class template specialization that is implicitely instantiated,
6722 e.g.:
6723 template<class T>
6724 struct S
6725 {
6726 template<class U> struct M {}; //#0
6727 };
6729 template<>
6730 template<>
6731 struct S<int>::M<char> //#1
6732 {
6733 int i;
6734 };
6735 [temp.expl.spec]/4 says this is valid.
6737 In this case, when we write:
6738 S<int>::M<char> m;
6740 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6741 the one of #0.
6743 When we encounter #1, we want to store the partial instantiation
6744 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6746 For all cases other than this "explicit specialization of member of a
6747 class template", we just want to store the most general template into
6748 the CLASSTYPE_TI_TEMPLATE of M.
6750 This case of "explicit specialization of member of a class template"
6751 only happens when:
6752 1/ the enclosing class is an instantiation of, and therefore not
6753 the same as, the context of the most general template, and
6754 2/ we aren't looking at the partial instantiation itself, i.e.
6755 the innermost arguments are not the same as the innermost parms of
6756 the most general template.
6758 So it's only when 1/ and 2/ happens that we want to use the partial
6759 instantiation of the member template in lieu of its most general
6760 template. */
6764 /* the enclosing class must be an instantiation... */
6767 {
6768 tree partial_inst_args;
6771 partial_inst_args =
6777 use_partial_inst_tmpl =
6778 /*...and we must not be looking at the partial instantiation
6779 itself. */
6781 partial_inst_args);
6782 }
6785 /* This case is easy; there are no member templates involved. */
6787 else
6788 {
6789 /* This is a full instantiation of a member template. Find
6790 the partial instantiation of which this is an instance. */
6792 /* Temporarily reduce by one the number of levels in the ARGLIST
6793 so as to avoid comparing the last set of arguments. */
6798 }
6808 /* Note this use of the partial instantiation so we can check it
6809 later in maybe_process_partial_specialization. */
6815 /* Now that the type has been registered on the instantiations
6816 list, we set up the enumerators. Because the enumeration
6817 constants may involve the enumeration type itself, we make
6818 sure to register the type first, and then create the
6819 constants. That way, doing tsubst_expr for the enumeration
6820 constants won't result in recursive calls here; we'll find
6821 the instantiation and exit above. */
6825 /* If the type makes use of template parameters, the
6826 code that generates debugging information will crash. */
6829 /* Possibly limit visibility based on template args. */
6834 }
6836 }
6837 \f
6838 struct pair_fn_data
6839 {
6840 tree_fn_t fn;
6842 /* True when we should also visit template parameters that occur in
6843 non-deduced contexts. */
6846 };
6848 /* Called from for_each_template_parm via walk_tree. */
6850 static tree
6852 {
6865 {
6869 /* Fall through. */
6892 /* Since we're not going to walk subtrees, we have to do this
6893 explicitly here. */
6897 /* Fall through. */
6900 /* Check the return type. */
6905 /* Check the parameter types. Since default arguments are not
6906 instantiated until they are needed, the TYPE_ARG_TYPES may
6907 contain expressions that involve template parameters. But,
6908 no-one should be looking at them yet. And, once they're
6909 instantiated, they don't contain template parameters, so
6910 there's no point in looking at them then, either. */
6911 {
6912 tree parm;
6919 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6920 want walk_tree walking into them itself. */
6922 }
6939 /* Fall through. */
6955 /* Record template parameters such as `T' inside `TT<T>'. */
6959 /* Fall through. */
6971 /* A template template parameter is encountered. */
6977 /* Already substituted template template parameter */
7000 /* If there's no type, then this thing must be some expression
7001 involving template parameters. */
7022 }
7024 /* We didn't find any template parameters we liked. */
7026 }
7028 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7029 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7030 call FN with the parameter and the DATA.
7031 If FN returns nonzero, the iteration is terminated, and
7032 for_each_template_parm returns 1. Otherwise, the iteration
7033 continues. If FN never returns a nonzero value, the value
7034 returned by for_each_template_parm is 0. If FN is NULL, it is
7035 considered to be the function which always returns 1.
7037 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7038 parameters that occur in non-deduced contexts. When false, only
7039 visits those template parameters that can be deduced. */
7041 static int
7045 {
7049 /* Set up. */
7054 /* Walk the tree. (Conceptually, we would like to walk without
7055 duplicates, but for_each_template_parm_r recursively calls
7056 for_each_template_parm, so we would need to reorganize a fair
7057 bit to use walk_tree_without_duplicates, so we keep our own
7058 visited list.) */
7061 else
7064 for_each_template_parm_r,
7068 /* Clean up. */
7070 {
7073 }
7076 }
7078 /* Returns true if T depends on any template parameter. */
7080 int
7082 {
7109 else
7110 {
7113 }
7118 }
7120 /* Returns true if T depends on any template parameter with level LEVEL. */
7122 int
7124 {
7127 }
7131 #ifdef GATHER_STATISTICS
7133 #endif
7137 /* We're starting to instantiate D; record the template instantiation context
7138 for diagnostics and to restore it later. */
7140 int
7142 {
7146 {
7147 /* If the instantiation in question still has unbound template parms,
7148 we don't really care if we can't instantiate it, so just return.
7149 This happens with base instantiation for implicit `typename'. */
7161 }
7171 #ifdef GATHER_STATISTICS
7174 #endif
7178 }
7180 /* We're done instantiating this template; return to the instantiation
7181 context. */
7183 void
7185 {
7186 /* Restore the filename and line number stashed away when we started
7187 this instantiation. */
7192 }
7194 /* We're instantiating a deferred template; restore the template
7195 instantiation context in which the instantiation was requested, which
7196 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7198 static tree
7200 {
7210 }
7212 /* Returns the TINST_LEVEL which gives the original instantiation
7213 context. */
7217 {
7223 }
7225 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7227 bool
7229 {
7230 tree parms;
7247 }
7249 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7250 vector of template arguments, as for tsubst.
7252 Returns an appropriate tsubst'd friend declaration. */
7254 static tree
7256 {
7257 tree new_friend;
7262 /* This was a friend declared with an explicit template
7263 argument list, e.g.:
7265 friend void f<>(T);
7267 to indicate that f was a template instantiation, not a new
7268 function declaration. Now, we have to figure out what
7269 instantiation of what template. */
7270 {
7272 tree new_args;
7273 tree tmpl;
7276 /* Friend functions are looked up in the containing namespace scope.
7277 We must enter that scope, to avoid finding member functions of the
7278 current class with same name. */
7293 tsk_none);
7295 }
7299 /* The NEW_FRIEND will look like an instantiation, to the
7300 compiler, but is not an instantiation from the point of view of
7301 the language. For example, we might have had:
7303 template <class T> struct S {
7304 template <class U> friend void f(T, U);
7305 };
7307 Then, in S<int>, template <class U> void f(int, U) is not an
7308 instantiation of anything. */
7314 {
7318 }
7320 /* The mangled name for the NEW_FRIEND is incorrect. The function
7321 is not a template instantiation and should not be mangled like
7322 one. Therefore, we forget the mangling here; we'll recompute it
7323 later if we need it. */
7325 {
7328 }
7331 {
7332 tree old_decl;
7333 tree new_friend_template_info;
7334 tree new_friend_result_template_info;
7335 tree ns;
7338 /* We must save some information from NEW_FRIEND before calling
7339 duplicate decls since that function will free NEW_FRIEND if
7340 possible. */
7342 new_friend_is_defn =
7347 {
7348 /* This declaration is a `primary' template. */
7351 new_friend_result_template_info
7353 }
7354 else
7357 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7361 /* Inside pushdecl_namespace_level, we will push into the
7362 current namespace. However, the friend function should go
7363 into the namespace of the template. */
7373 {
7374 /* This new friend declaration matched an existing
7375 declaration. For example, given:
7377 template <class T> void f(T);
7378 template <class U> class C {
7379 template <class T> friend void f(T) {}
7380 };
7382 the friend declaration actually provides the definition
7383 of `f', once C has been instantiated for some type. So,
7384 old_decl will be the out-of-class template declaration,
7385 while new_friend is the in-class definition.
7387 But, if `f' was called before this point, the
7388 instantiation of `f' will have DECL_TI_ARGS corresponding
7389 to `T' but not to `U', references to which might appear
7390 in the definition of `f'. Previously, the most general
7391 template for an instantiation of `f' was the out-of-class
7392 version; now it is the in-class version. Therefore, we
7393 run through all specialization of `f', adding to their
7394 DECL_TI_ARGS appropriately. In particular, they need a
7395 new set of outer arguments, corresponding to the
7396 arguments for this class instantiation.
7398 The same situation can arise with something like this:
7400 friend void f(int);
7401 template <class T> class C {
7402 friend void f(T) {}
7403 };
7405 when `C<int>' is instantiated. Now, `f(int)' is defined
7406 in the class. */
7409 /* On the other hand, if the in-class declaration does
7410 *not* provide a definition, then we don't want to alter
7411 existing definitions. We can just leave everything
7412 alone. */
7413 ;
7414 else
7415 {
7419 /* Overwrite whatever template info was there before, if
7420 any, with the new template information pertaining to
7421 the declaration. */
7425 {
7426 /* We should have called reregister_specialization in
7427 duplicate_decls. */
7432 /* Instantiate it if the global has already been used. */
7436 }
7437 else
7438 {
7439 tree t;
7441 /* Indicate that the old function template is a partial
7442 instantiation. */
7450 /* Reassign any specializations already in the hash table
7451 to the new more general template, and add the
7452 additional template args. */
7456 {
7458 spec_entry elt;
7470 register_specialization
7473 }
7475 }
7476 }
7478 /* The information from NEW_FRIEND has been merged into OLD_DECL
7479 by duplicate_decls. */
7481 }
7482 }
7483 else
7484 {
7488 /* In the code
7489 template <class T> class C {
7490 template <class U> friend void C1<U>::f (); // case 1
7491 friend void C2<T>::f (); // case 2
7492 };
7493 we only need to make sure CONTEXT is a complete type for
7494 case 2. To distinguish between the two cases, we note that
7495 CONTEXT of case 1 remains dependent type after tsubst while
7496 this isn't true for case 2. */
7506 {
7507 /* Check to see that the declaration is really present, and,
7508 possibly obtain an improved declaration. */
7514 }
7515 }
7518 }
7520 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7521 template arguments, as for tsubst.
7523 Returns an appropriate tsubst'd friend type or error_mark_node on
7524 failure. */
7526 static tree
7528 {
7529 tree friend_type;
7530 tree tmpl;
7531 tree context;
7536 {
7539 else
7541 }
7543 /* Look for a class template declaration. We look for hidden names
7544 because two friend declarations of the same template are the
7545 same. For example, in:
7547 struct A {
7548 template <typename> friend class F;
7549 };
7550 template <typename> struct B {
7551 template <typename> friend class F;
7552 };
7554 both F templates are the same. */
7559 /* But, if we don't find one, it might be because we're in a
7560 situation like this:
7562 template <class T>
7563 struct S {
7564 template <class U>
7565 friend struct S;
7566 };
7568 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7569 for `S<int>', not the TEMPLATE_DECL. */
7571 {
7574 }
7577 {
7578 /* The friend template has already been declared. Just
7579 check to see that the declarations match, and install any new
7580 default parameters. We must tsubst the default parameters,
7581 of course. We only need the innermost template parameters
7582 because that is all that redeclare_class_template will look
7583 at. */
7586 {
7587 tree parms;
7588 location_t saved_input_location;
7597 }
7600 }
7601 else
7602 {
7603 /* The friend template has not already been declared. In this
7604 case, the instantiation of the template class will cause the
7605 injection of this template into the global scope. */
7610 /* The new TMPL is not an instantiation of anything, so we
7611 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7612 the new type because that is supposed to be the corresponding
7613 template decl, i.e., TMPL. */
7620 /* Inject this template into the global scope. */
7622 }
7625 {
7628 else
7630 }
7633 }
7635 /* Returns zero if TYPE cannot be completed later due to circularity.
7636 Otherwise returns one. */
7638 static int
7640 {
7650 else
7652 }
7654 /* Apply any attributes which had to be deferred until instantiation
7655 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7656 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7658 static void
7661 {
7663 tree t;
7668 {
7672 }
7675 {
7679 }
7680 else
7684 {
7689 {
7692 {
7695 /* If the first attribute argument is an identifier, don't
7696 pass it through tsubst. Attributes like mode, format,
7697 cleanup and several target specific attributes expect it
7698 unmodified. */
7704 {
7705 tree chain
7707 in_decl,
7712 chain);
7713 }
7714 else
7720 }
7721 else
7723 }
7726 }
7727 }
7729 /* Perform (or defer) access check for typedefs that were referenced
7730 from within the template TMPL code.
7731 This is a subroutine of instantiate_template and instantiate_class_template.
7732 TMPL is the template to consider and TARGS is the list of arguments of
7733 that template. */
7735 static void
7737 {
7738 location_t saved_location;
7751 {
7763 /* Make access check error messages point to the location
7764 of the use of the typedef. */
7768 }
7770 }
7772 tree
7774 {
7776 tree typedecl;
7777 tree pbinfo;
7778 tree base_list;
7788 /* Figure out which template is being instantiated. */
7792 /* Determine what specialization of the original template to
7793 instantiate. */
7796 {
7799 }
7801 {
7802 /* This TYPE is actually an instantiation of a partial
7803 specialization. We replace the innermost set of ARGS with
7804 the arguments appropriate for substitution. For example,
7805 given:
7807 template <class T> struct S {};
7808 template <class T> struct S<T*> {};
7810 and supposing that we are instantiating S<int*>, ARGS will
7811 presently be {int*} -- but we need {int}. */
7814 }
7815 else
7816 {
7819 }
7821 /* If the template we're instantiating is incomplete, then clearly
7822 there's nothing we can do. */
7826 /* If we've recursively instantiated too many templates, stop. */
7830 /* Now we're really doing the instantiation. Mark the type as in
7831 the process of being defined. */
7834 /* We may be in the middle of deferred access check. Disable
7835 it now. */
7839 /* Use #pragma pack from the template context. */
7845 /* Set the input location to the most specialized template definition.
7846 This is needed if tsubsting causes an error. */
7868 {
7871 }
7875 /* We should never instantiate a nested class before its enclosing
7876 class; we need to look up the nested class by name before we can
7877 instantiate it, and that lookup should instantiate the enclosing
7878 class. */
7884 {
7885 tree pbase_binfo;
7887 tree pushed_scope;
7890 /* We must enter the scope containing the type, as that is where
7891 the accessibility of types named in dependent bases are
7892 looked up from. */
7895 /* Substitute into each of the bases to determine the actual
7896 basetypes. */
7898 {
7899 tree base;
7905 {
7906 expanded_bases =
7913 }
7916 {
7918 /* Extract the already-expanded base class. */
7920 else
7921 /* Substitute to figure out the base class. */
7923 NULL_TREE);
7931 }
7932 }
7934 /* The list is now in reverse order; correct that. */
7939 }
7940 /* Now call xref_basetypes to set up all the base-class
7941 information. */
7948 /* Now that our base classes are set up, enter the scope of the
7949 class, so that name lookups into base classes, etc. will work
7950 correctly. This is precisely analogous to what we do in
7951 begin_class_definition when defining an ordinary non-template
7952 class, except we also need to push the enclosing classes. */
7955 /* Now members are processed in the order of declaration. */
7958 {
7962 {
7964 {
7965 /* Build new CLASSTYPE_NESTED_UTDS. */
7967 tree newtag;
7973 /* If the member is a class template, then -- even after
7974 substitution -- there may be dependent types in the
7975 template argument list for the class. We increment
7976 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7977 that function will assume that no types are dependent
7978 when outside of a template. */
7988 {
7992 /* Unfortunately, lookup_template_class sets
7993 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7994 instantiation (i.e., for the type of a member
7995 template class nested within a template class.)
7996 This behavior is required for
7997 maybe_process_partial_specialization to work
7998 correctly, but is not accurate in this case;
7999 the TAG is not an instantiation of anything.
8000 (The corresponding TEMPLATE_DECL is an
8001 instantiation, but the TYPE is not.) */
8004 /* Now, we call pushtag to put this NEWTAG into the scope of
8005 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8006 pushtag calling push_template_decl. We don't have to do
8007 this for enums because it will already have been done in
8008 tsubst_enum. */
8012 }
8013 }
8016 {
8017 /* Build new TYPE_METHODS. */
8018 tree r;
8027 }
8028 else
8029 {
8030 /* Build new TYPE_FIELDS. */
8032 {
8033 tree condition =
8041 }
8043 {
8044 tree r;
8046 /* The file and line for this declaration, to
8047 assist in error message reporting. Since we
8048 called push_tinst_level above, we don't need to
8049 restore these. */
8058 {
8059 /* In [temp.inst]:
8061 [t]he initialization (and any associated
8062 side-effects) of a static data member does
8063 not occur unless the static data member is
8064 itself used in a way that requires the
8065 definition of the static data member to
8066 exist.
8068 Therefore, we do not substitute into the
8069 initialized for the static data member here. */
8070 finish_static_data_member_decl
8078 }
8080 {
8081 /* Determine whether R has a valid type and can be
8082 completed later. If R is invalid, then it is
8083 replaced by error_mark_node so that it will not be
8084 added to TYPE_FIELDS. */
8090 {
8093 }
8094 }
8096 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8097 such a thing will already have been added to the field
8098 list by tsubst_enum in finish_member_declaration in the
8099 CLASSTYPE_NESTED_UTDS case above. */
8103 {
8106 }
8107 }
8108 }
8109 }
8110 else
8111 {
8113 {
8114 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8120 {
8121 /* template <class T> friend class C; */
8124 }
8126 {
8127 /* template <class T> friend class C::D; */
8133 }
8135 {
8136 /* This could be either
8138 friend class T::C;
8140 when dependent_type_p is false or
8142 template <class U> friend class T::C;
8144 otherwise. */
8147 /* Bump processing_template_decl for correct
8148 dependent_type_p calculation. */
8153 }
8156 {
8157 /* friend class C;
8159 where C hasn't been declared yet. Let's lookup name
8160 from namespace scope directly, bypassing any name that
8161 come from dependent base class. */
8164 /* The call to xref_tag_from_type does injection for friend
8165 classes. */
8167 friend_type =
8171 }
8173 /* friend class C<T>; */
8176 /* Otherwise it's
8178 friend class C;
8180 where C is already declared or
8182 friend class C<int>;
8184 We don't have to do anything in these cases. */
8187 /* Trick make_friend_class into realizing that the friend
8188 we're adding is a template, not an ordinary class. It's
8189 important that we use make_friend_class since it will
8190 perform some error-checking and output cross-reference
8191 information. */
8199 }
8200 else
8201 {
8202 /* Build new DECL_FRIENDLIST. */
8203 tree r;
8205 /* The file and line for this declaration, to
8206 assist in error message reporting. Since we
8207 called push_tinst_level above, we don't need to
8208 restore these. */
8212 {
8215 }
8220 {
8223 }
8224 }
8225 }
8226 }
8228 /* Set the file and line number information to whatever is given for
8229 the class itself. This puts error messages involving generated
8230 implicit functions at a predictable point, and the same point
8231 that would be used for non-template classes. */
8238 /* Now that the class is complete, instantiate default arguments for
8239 any member functions. We don't do this earlier because the
8240 default arguments may reference members of the class. */
8244 /* Implicitly generated member functions will not have template
8245 information; they are not instantiations, but instead are
8246 created "fresh" for each instantiation. */
8250 /* Some typedefs referenced from within the template code need to be access
8251 checked at template instantiation time, i.e now. These types were
8252 added to the template at parsing time. Let's get those and perform
8253 the access checks then. */
8262 /* The vtable for a template class can be emitted in any translation
8263 unit in which the class is instantiated. When there is no key
8264 method, however, finish_struct_1 will already have added TYPE to
8265 the keyed_classes list. */
8270 }
8272 static tree
8274 {
8275 tree r;
8281 else
8282 {
8289 }
8291 }
8293 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8294 NONTYPE_ARGUMENT_PACK. */
8296 static tree
8298 {
8299 /* Collect all of the extra "packed" parameters into an
8300 argument pack. */
8301 tree parmvec;
8302 tree parmtypevec;
8307 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8311 {
8314 }
8316 /* Build the argument packs. */
8322 }
8324 /* Substitute ARGS into T, which is an pack expansion
8325 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8326 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8327 (if only a partial substitution could be performed) or
8328 ERROR_MARK_NODE if there was an error. */
8329 tree
8331 tree in_decl)
8332 {
8333 tree pattern;
8336 tree result;
8343 /* Determine the argument packs that will instantiate the parameter
8344 packs used in the expansion expression. While we're at it,
8345 compute the number of arguments to be expanded and make sure it
8346 is consistent. */
8349 {
8355 {
8358 else
8359 {
8360 /* We can't rely on local_specializations for a parameter
8361 name used later in a function declaration (such as in a
8362 late-specified return type). Even if it exists, it might
8363 have the wrong value for a recursive call. Just make a
8364 dummy decl, since it's only used for its type. */
8367 }
8368 }
8369 else
8370 {
8377 }
8384 /* This can only happen if we forget to expand an argument
8385 pack somewhere else. Just return an error, silently. */
8386 {
8390 }
8395 {
8400 /* The argument pack that the parameter maps to is just an
8401 expansion of the parameter itself, such as one would
8402 find in the implicit typedef of a class inside the
8403 class itself. Consider this parameter "unsubstituted",
8404 so that we will maintain the outer pack expansion. */
8406 }
8409 {
8413 /* It's all-or-nothing with incomplete argument packs. */
8423 {
8425 /* We got explicit args for some packs but not others;
8426 do nothing now and try again after deduction. */
8431 pattern);
8432 else
8435 pattern);
8437 }
8439 /* Keep track of the parameter packs and their corresponding
8440 argument packs. */
8443 }
8444 else
8445 /* We can't substitute for this parameter pack. */
8448 unsubstituted_packs);
8449 }
8451 /* We cannot expand this expansion expression, because we don't have
8452 all of the argument packs we need. Substitute into the pattern
8453 and return a PACK_EXPANSION_*. The caller will need to deal with
8454 that. */
8456 {
8457 tree new_pat;
8461 else
8464 }
8466 /* We could not find any argument packs that work. */
8471 {
8472 /* We're in a late-specified return type, so create our own local
8473 specializations table; the current table is either NULL or (in the
8474 case of recursive unification) might have bindings that we don't
8475 want to use or alter. */
8478 hash_local_specialization,
8479 eq_local_specializations,
8480 NULL);
8481 }
8483 /* For each argument in each argument pack, substitute into the
8484 pattern. */
8487 {
8488 /* For parameter pack, change the substitution of the parameter
8489 pack to the ith argument in its argument pack, then expand
8490 the pattern. */
8492 {
8496 {
8497 /* Select the Ith argument from the pack. */
8503 }
8504 else
8505 {
8511 {
8512 /* Select the Ith argument from the pack. */
8516 }
8518 /* Update the corresponding argument. */
8520 }
8521 }
8523 /* Substitute into the PATTERN with the altered arguments. */
8528 else
8532 /* When we have incomplete argument packs, the last "expanded"
8533 result is itself a pack expansion, which allows us
8534 to deduce more arguments. */
8539 {
8542 }
8543 }
8545 /* Update ARGS to restore the substitution from parameter packs to
8546 their argument packs. */
8548 {
8553 else
8554 {
8558 /* Update the corresponding argument. */
8562 else
8564 }
8565 }
8568 {
8571 }
8574 }
8576 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8577 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8578 parameter packs; all parms generated from a function parameter pack will
8579 have the same DECL_PARM_INDEX. */
8581 tree
8583 {
8585 tree patparm;
8588 {
8594 }
8595 else
8596 {
8601 }
8604 }
8606 /* Substitute ARGS into the vector or list of template arguments T. */
8608 static tree
8610 {
8617 {
8619 tree new_arg;
8624 {
8625 /* Substitute into an expansion expression. */
8629 /* Add to the expanded length adjustment the number of
8630 expanded arguments. We subtract one from this
8631 measurement, because the argument pack expression
8632 itself is already counted as 1 in
8633 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8634 the argument pack is empty. */
8636 }
8638 {
8639 /* Substitute into each of the arguments. */
8645 new_arg,
8659 }
8660 }
8661 else
8670 }
8675 /* Make space for the expanded arguments coming from template
8676 argument packs. */
8678 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8679 arguments for a member template.
8680 In that case each TREE_VEC in ORIG_T represents a level of template
8681 arguments, and ORIG_T won't carry any non defaulted argument count.
8682 It will rather be the nested TREE_VECs that will carry one.
8683 In other words, ORIG_T carries a non defaulted argument count only
8684 if it doesn't contain any nested TREE_VEC. */
8686 {
8690 }
8692 {
8696 {
8699 /* Now expand the template argument pack "in place". */
8702 }
8703 else
8704 {
8706 out++;
8707 }
8708 }
8711 }
8713 /* Return the result of substituting ARGS into the template parameters
8714 given by PARMS. If there are m levels of ARGS and m + n levels of
8715 PARMS, then the result will contain n levels of PARMS. For
8716 example, if PARMS is `template <class T> template <class U>
8717 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8718 result will be `template <int*, double, class V>'. */
8720 static tree
8722 {
8726 /* When substituting into a template, we must set
8727 PROCESSING_TEMPLATE_DECL as the template parameters may be
8728 dependent if they are based on one-another, and the dependency
8729 predicates are short-circuit outside of templates. */
8736 {
8737 tree new_vec =
8742 {
8743 tree tuple;
8744 tree default_value;
8745 tree parm_decl;
8767 }
8773 }
8778 }
8780 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8781 type T. If T is not an aggregate or enumeration type, it is
8782 handled as if by tsubst. IN_DECL is as for tsubst. If
8783 ENTERING_SCOPE is nonzero, T is the context for a template which
8784 we are presently tsubst'ing. Return the substituted value. */
8786 static tree
8788 tree args,
8789 tsubst_flags_t complain,
8790 tree in_decl,
8792 {
8797 {
8802 /* Else fall through. */
8806 {
8807 tree argvec;
8808 tree context;
8809 tree r;
8813 /* In "sizeof(X<I>)" we need to evaluate "I". */
8819 /* First, determine the context for the type we are looking
8820 up. */
8823 {
8826 /* If context is a nested class inside a class template,
8827 it may still need to be instantiated (c++/33959). */
8830 }
8832 /* Then, figure out what arguments are appropriate for the
8833 type we are trying to find. For example, given:
8835 template <class T> struct S;
8836 template <class T, class U> void f(T, U) { S<U> su; }
8838 and supposing that we are instantiating f<int, double>,
8839 then our ARGS will be {int, double}, but, when looking up
8840 S we only want {double}. */
8845 else
8846 {
8850 }
8856 }
8857 else
8858 /* This is not a template type, so there's nothing to do. */
8863 }
8864 }
8866 /* Substitute into the default argument ARG (a default argument for
8867 FN), which has the indicated TYPE. */
8869 tree
8871 {
8875 /* This default argument came from a template. Instantiate the
8876 default argument here, not in tsubst. In the case of
8877 something like:
8879 template <class T>
8880 struct S {
8881 static T t();
8882 void f(T = t());
8883 };
8885 we must be careful to do name lookup in the scope of S<T>,
8886 rather than in the current class. */
8888 /* The "this" pointer is not valid in a default argument. */
8890 {
8895 }
8898 /* The default argument expression may cause implicitly defined
8899 member functions to be synthesized, which will result in garbage
8900 collection. We must treat this situation as if we were within
8901 the body of function so as to avoid collecting live data on the
8902 stack. */
8910 /* Restore the "this" pointer. */
8912 {
8915 }
8917 /* Make sure the default argument is reasonable. */
8923 }
8925 /* Substitute into all the default arguments for FN. */
8927 static void
8929 {
8930 tree arg;
8931 tree tmpl_args;
8935 /* If this function is not yet instantiated, we certainly don't need
8936 its default arguments. */
8941 arg;
8947 }
8949 /* Substitute the ARGS into the T, which is a _DECL. Return the
8950 result of the substitution. Issue error and warning messages under
8951 control of COMPLAIN. */
8953 static tree
8955 {
8956 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8957 location_t saved_loc;
8962 /* Set the filename and linenumber to improve error-reporting. */
8967 {
8969 {
8970 /* We can get here when processing a member function template,
8971 member class template, or template template parameter. */
8973 tree spec;
8974 tree tmpl_args;
8975 tree full_args;
8978 {
8979 /* Template template parameter is treated here. */
8992 complain);
8995 }
8997 /* We might already have an instance of this template.
8998 The ARGS are for the surrounding class type, so the
8999 full args contain the tsubst'd args for the context,
9000 plus the innermost args from the template decl. */
9004 /* Because this is a template, the arguments will still be
9005 dependent, even after substitution. If
9006 PROCESSING_TEMPLATE_DECL is not set, the dependency
9007 predicates will short-circuit. */
9015 /* If this is a default template template argument,
9016 tsubst might not have changed anything. */
9023 {
9026 }
9028 /* Make a new template decl. It will be similar to the
9029 original, but will record the current template arguments.
9030 We also create a new function declaration, which is just
9031 like the old one, but points to this new template, rather
9032 than the old one. */
9040 {
9041 tree new_type;
9053 }
9054 else
9055 {
9056 tree new_decl;
9068 }
9074 /* The template parameters for this new template are all the
9075 template parameters for the old template, except the
9076 outermost level of parameters. */
9079 complain);
9085 /* Record this non-type partial instantiation. */
9089 }
9093 {
9094 tree ctx;
9097 tree gen_tmpl;
9098 tree type;
9103 /* Nobody should be tsubst'ing into non-template functions. */
9107 {
9108 tree spec;
9111 /* If T is not dependent, just return it. We have to
9112 increment PROCESSING_TEMPLATE_DECL because
9113 value_dependent_expression_p assumes that nothing is
9114 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9121 /* Calculate the most general template of which R is a
9122 specialization, and the complete set of arguments used to
9123 specialize R. */
9126 (DECL_TEMPLATE_RESULT
9130 /* Check to see if we already have this specialization. */
9135 {
9138 }
9140 /* We can see more levels of arguments than parameters if
9141 there was a specialization of a member template, like
9142 this:
9144 template <class T> struct S { template <class U> void f(); }
9145 template <> template <class U> void S<int>::f(U);
9147 Here, we'll be substituting into the specialization,
9148 because that's where we can find the code we actually
9149 want to generate, but we'll have enough arguments for
9150 the most general template.
9152 We also deal with the peculiar case:
9154 template <class T> struct S {
9155 template <class U> friend void f();
9156 };
9157 template <class U> void f() {}
9158 template S<int>;
9159 template void f<double>();
9161 Here, the ARGS for the instantiation of will be {int,
9162 double}. But, we only need as many ARGS as there are
9163 levels of template parameters in CODE_PATTERN. We are
9164 careful not to get fooled into reducing the ARGS in
9165 situations like:
9167 template <class T> struct S { template <class U> void f(U); }
9168 template <class T> template <> void S<T>::f(int) {}
9170 which we can spot because the pattern will be a
9171 specialization in this case. */
9173 parms_depth =
9178 }
9179 else
9180 {
9181 /* This special case arises when we have something like this:
9183 template <class T> struct S {
9184 friend void f<int>(int, double);
9185 };
9187 Here, the DECL_TI_TEMPLATE for the friend declaration
9188 will be an IDENTIFIER_NODE. We are being called from
9189 tsubst_friend_function, and we want only to create a
9190 new decl (R) with appropriate types so that we can call
9191 determine_specialization. */
9193 }
9196 {
9199 else
9203 }
9204 else
9205 {
9208 }
9213 /* We do NOT check for matching decls pushed separately at this
9214 point, as they may not represent instantiations of this
9215 template, and in any case are considered separate under the
9216 discrete model. */
9220 /* Clear out the mangled name and RTL for the instantiation. */
9223 /* Leave DECL_INITIAL set on deleted instantiations. */
9229 /* Type-conversion operator. Reconstruct the name, in
9230 case it's the name of one of the template's parameters. */
9240 /* If this is an instantiation of a function with internal
9241 linkage, we already know what object file linkage will be
9242 assigned to the instantiation. */
9251 /* We'll re-clone as appropriate in instantiate_template. */
9254 /* If we aren't complaining now, return on error before we register
9255 the specialization so that we'll complain eventually. */
9261 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9262 this in the special friend case mentioned above where
9263 GEN_TMPL is NULL. */
9265 {
9271 /* We're not supposed to instantiate default arguments
9272 until they are called, for a template. But, for a
9273 declaration like:
9275 template <class T> void f ()
9276 { extern void g(int i = T()); }
9278 we should do the substitution when the template is
9279 instantiated. We handle the member function case in
9280 instantiate_class_template since the default arguments
9281 might refer to other members of the class. */
9286 }
9287 else
9290 /* Copy the list of befriending classes. */
9294 {
9298 in_decl);
9299 }
9302 {
9306 /* If this is an instantiation of a member template, clone it.
9307 If it isn't, that'll be handled by
9308 clone_constructors_and_destructors. */
9311 }
9322 /* Possibly limit visibility based on template args. */
9325 {
9329 }
9337 }
9341 {
9349 {
9350 /* If there is a local specialization that isn't a
9351 parameter pack, it means that we're doing a "simple"
9352 substitution from inside tsubst_pack_expansion. Just
9353 return the local specialization (which will be a single
9354 parm). */
9361 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9362 the parameters in this function parameter pack. */
9366 {
9369 /* Zero-length parameter packs are boring. Just substitute
9370 into the chain. */
9374 }
9375 else
9376 {
9377 /* All we did was update the type. Make a note of that. */
9380 }
9381 }
9383 /* Loop through all of the parameter's we'll build. When T is
9384 a function parameter pack, LEN is the number of expanded
9385 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9388 {
9394 /* An argument of a function parameter pack is not a parameter
9395 pack. */
9399 /* We're on the Ith parameter of the function parameter
9400 pack. */
9401 {
9402 /* Get the Ith type. */
9406 /* Rename the parameter to include the index. */
9409 }
9411 /* We're dealing with a normal parameter. */
9419 {
9422 else
9425 }
9435 /* Keep track of the first new parameter we
9436 generate. That's what will be returned to the
9437 caller. */
9441 /* Build a proper chain of parameters when substituting
9442 into a function parameter pack. */
9445 }
9451 /* FIRST_R contains the start of the chain we've built. */
9453 }
9457 {
9458 tree type;
9467 /* DECL_INITIAL gives the number of bits in a bit-field. */
9472 /* We don't have to set DECL_CONTEXT here; it is set by
9473 finish_member_declaration. */
9480 }
9484 /* We reach here only for member using decls. */
9486 {
9487 r = do_class_using_decl
9492 else
9493 {
9496 }
9497 }
9498 else
9499 {
9502 }
9507 {
9510 tree spec;
9512 tree ctx;
9518 {
9519 /* If this is the canonical decl, we don't have to
9520 mess with instantiations, and often we can't (for
9521 typename, template type parms and such). Note that
9522 TYPE_NAME is not correct for the above test if
9523 we've copied the type for a typedef. */
9529 }
9531 /* Check to see if we already have the specialization we
9532 need. */
9535 {
9536 /* T is a static data member or namespace-scope entity.
9537 We have to substitute into namespace-scope variables
9538 (even though such entities are never templates) because
9539 of cases like:
9541 template <class T> void f() { extern T t; }
9543 where the entity referenced is not known until
9544 instantiation time. */
9548 {
9550 complain,
9552 /* If CTX is unchanged, then T is in fact the
9553 specialization we want. That situation occurs when
9554 referencing a static data member within in its own
9555 class. We can use pointer equality, rather than
9556 same_type_p, because DECL_CONTEXT is always
9557 canonical. */
9560 }
9563 {
9569 }
9570 }
9571 else
9572 {
9573 /* A local variable. */
9575 /* Subsequent calls to pushdecl will fill this in. */
9578 }
9579 /* If we already have the specialization we need, there is
9580 nothing more to do. */
9582 {
9585 }
9587 /* Create a new node for the specialization we need. */
9590 {
9593 else
9598 }
9600 {
9601 /* Even if the original location is out of scope, the
9602 newly substituted one is not. */
9609 {
9610 /* It may seem that this case cannot occur, since:
9612 typedef void f();
9613 void g() { f x; }
9615 declares a function, not a variable. However:
9617 typedef void f();
9618 template <typename T> void g() { T t; }
9619 template void g<f>();
9621 is an attempt to declare a variable with function
9622 type. */
9624 /* R is not yet sufficiently initialized, so we
9625 just use its name. */
9628 }
9635 {
9640 }
9641 }
9647 /* Clear out the mangled name and RTL for the instantiation. */
9651 /* The initializer must not be expanded until it is required;
9652 see [temp.inst]. */
9658 {
9659 /* Possibly limit visibility based on template args. */
9662 {
9666 }
9668 }
9671 {
9672 /* A static data member declaration is always marked
9673 external when it is declared in-class, even if an
9674 initializer is present. We mimic the non-template
9675 processing here. */
9681 }
9683 {
9684 /* We're substituting this var in a decltype outside of its
9685 scope, such as for a lambda return type. Don't add it to
9686 local_specializations, do perform auto deduction. */
9688 tree init
9693 {
9696 }
9697 }
9698 else
9707 /* Preserve a typedef that names a type. */
9709 {
9712 }
9715 }
9720 }
9721 #undef RETURN
9723 out:
9724 /* Restore the file and line information. */
9728 }
9730 /* Substitute into the ARG_TYPES of a function type. */
9732 static tree
9734 tree args,
9735 tsubst_flags_t complain,
9736 tree in_decl)
9737 {
9738 tree remaining_arg_types;
9742 tree default_arg;
9753 {
9754 /* For a pack expansion, perform substitution on the
9755 entire expression. Later on, we'll handle the arguments
9756 one-by-one. */
9761 /* So that we'll spin through the parameters, one by one. */
9763 else
9764 {
9765 /* We only partially substituted into the parameter
9766 pack. Our type is TYPE_PACK_EXPANSION. */
9769 }
9770 }
9783 {
9785 {
9789 }
9791 }
9793 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9794 top-level qualifiers as required. */
9797 /* We do not substitute into default arguments here. The standard
9798 mandates that they be instantiated only when needed, which is
9799 done in build_over_call. */
9803 {
9804 /* We've instantiated a template before its default arguments
9805 have been parsed. This can happen for a nested template
9806 class, and is not an error unless we require the default
9807 argument in a call of this function. */
9808 remaining_arg_types =
9811 remaining_arg_types);
9812 }
9813 else
9814 remaining_arg_types =
9816 }
9819 }
9821 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9822 *not* handle the exception-specification for FNTYPE, because the
9823 initial substitution of explicitly provided template parameters
9824 during argument deduction forbids substitution into the
9825 exception-specification:
9827 [temp.deduct]
9829 All references in the function type of the function template to the
9830 corresponding template parameters are replaced by the specified tem-
9831 plate argument values. If a substitution in a template parameter or
9832 in the function type of the function template results in an invalid
9833 type, type deduction fails. [Note: The equivalent substitution in
9834 exception specifications is done only when the function is instanti-
9835 ated, at which point a program is ill-formed if the substitution
9836 results in an invalid type.] */
9838 static tree
9840 tree args,
9841 tsubst_flags_t complain,
9842 tree in_decl)
9843 {
9844 tree return_type;
9845 tree arg_types;
9846 tree fntype;
9848 /* The TYPE_CONTEXT is not used for function/method types. */
9851 /* Substitute the return type. */
9855 /* The standard does not presently indicate that creation of a
9856 function type with an invalid return type is a deduction failure.
9857 However, that is clearly analogous to creating an array of "void"
9858 or a reference to a reference. This is core issue #486. */
9861 {
9863 {
9866 else
9868 }
9870 }
9872 /* Substitute the argument types. */
9878 /* Construct a new type node and return it. */
9880 {
9883 }
9884 else
9885 {
9888 {
9889 /* [temp.deduct]
9891 Type deduction may fail for any of the following
9892 reasons:
9894 -- Attempting to create "pointer to member of T" when T
9895 is not a class type. */
9898 r);
9900 }
9904 }
9908 }
9910 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9911 ARGS into that specification, and return the substituted
9912 specification. If there is no specification, return NULL_TREE. */
9914 static tree
9916 tree args,
9917 tsubst_flags_t complain,
9918 tree in_decl)
9919 {
9920 tree specs;
9921 tree new_specs;
9926 {
9927 /* A noexcept-specifier. */
9928 new_specs = tsubst_copy_and_build
9932 }
9934 {
9937 else
9939 {
9940 tree spec;
9945 {
9946 /* Expand the pack expansion type. */
9949 in_decl);
9955 else
9956 {
9957 /* We're substituting into a member template, so
9958 we got a TYPE_PACK_EXPANSION back. Add that
9959 expansion and move on. */
9963 expanded_specs,
9964 complain);
9967 }
9968 }
9971 {
9974 else
9979 complain);
9980 }
9983 }
9984 }
9986 }
9988 /* Take the tree structure T and replace template parameters used
9989 therein with the argument vector ARGS. IN_DECL is an associated
9990 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9991 Issue error and warning messages under control of COMPLAIN. Note
9992 that we must be relatively non-tolerant of extensions here, in
9993 order to preserve conformance; if we allow substitutions that
9994 should not be allowed, we may allow argument deductions that should
9995 not succeed, and therefore report ambiguous overload situations
9996 where there are none. In theory, we could allow the substitution,
9997 but indicate that it should have failed, and allow our caller to
9998 make sure that the right thing happens, but we don't try to do this
9999 yet.
10001 This function is used for dealing with types, decls and the like;
10002 for expressions, use tsubst_expr or tsubst_copy. */
10004 tree
10006 {
10028 else
10033 /* Reuse typedefs. We need to do this to handle dependent attributes,
10034 such as attribute aligned. */
10038 {
10044 {
10048 }
10053 else
10054 /* The typedef is from a non-template context. */
10058 {
10060 r = cp_build_qualified_type_real
10064 }
10065 /* Else we must be instantiating the typedef, so fall through. */
10066 }
10079 {
10106 {
10112 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10113 needed. */
10122 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10123 with TREE_SIDE_EFFECTS that indicates this is not an integral
10124 constant expression. */
10127 {
10130 }
10136 {
10140 }
10142 /* [temp.deduct]
10144 Type deduction may fail for any of the following
10145 reasons:
10147 Attempting to create an array with a size that is
10148 zero or negative. */
10150 /* We must fail if performing argument deduction (as
10151 indicated by the state of complain), so that
10152 another substitution can be found. */
10156 {
10161 }
10164 }
10170 {
10183 {
10187 /* See through ARGUMENT_PACK_SELECT arguments. */
10189 }
10194 {
10196 /* If ARG is an argument pack, we don't actually want to
10197 perform a substitution here, because substitutions
10198 for argument packs are only done
10199 element-by-element. We can get to this point when
10200 substituting the type of a non-type template
10201 parameter pack, when that type actually contains
10202 template parameter packs from an outer template, e.g.,
10204 template<typename... Types> struct A {
10205 template<Types... Values> struct B { };
10206 }; */
10210 {
10216 return cp_build_qualified_type_real
10218 }
10220 {
10221 /* We are processing a type constructed from a
10222 template template parameter. */
10228 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10229 are resolving nested-types in the signature of a
10230 member function templates. Otherwise ARG is a
10231 TEMPLATE_DECL and is the real template to be
10232 instantiated. */
10240 complain);
10241 return cp_build_qualified_type_real
10243 }
10244 else
10245 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10247 }
10250 /* This can happen during the attempted tsubst'ing in
10251 unify. This means that we don't yet have any information
10252 about the template parameter in question. */
10255 /* If we get here, we must have been looking at a parm for a
10256 more deeply nested template. Make a new version of this
10257 template parameter, but with a lower level. */
10259 {
10264 {
10266 r = cp_build_qualified_type_real
10270 }
10271 else
10272 {
10283 /* We have reduced the level of the template
10284 template parameter, but not the levels of its
10285 template parameters, so canonical_type_parameter
10286 will not be able to find the canonical template
10287 template parameter for this level. Thus, we
10288 require structural equality checking to compare
10289 TEMPLATE_TEMPLATE_PARMs. */
10293 else
10297 {
10305 }
10306 }
10315 }
10318 }
10321 {
10329 {
10333 }
10336 {
10340 }
10343 {
10347 }
10353 }
10356 /* We should never be tsubsting a binfo. */
10360 /* A vector of template arguments. */
10366 {
10370 /* [temp.deduct]
10372 Type deduction may fail for any of the following
10373 reasons:
10375 -- Attempting to create a pointer to reference type.
10376 -- Attempting to create a reference to a reference type or
10377 a reference to void.
10379 Core issue 106 says that creating a reference to a reference
10380 during instantiation is no longer a cause for failure. We
10381 only enforce this check in strict C++98 mode. */
10385 {
10388 /* We keep track of the last time we issued this error
10389 message to avoid spewing a ton of messages during a
10390 single bad template instantiation. */
10393 {
10398 else
10401 }
10404 }
10406 {
10410 }
10412 /* In C++0x, during template argument substitution, when there is an
10413 attempt to create a reference to a reference type, reference
10414 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10416 "If a template-argument for a template-parameter T names a type
10417 that is a reference to a type A, an attempt to create the type
10418 'lvalue reference to cv T' creates the type 'lvalue reference to
10419 A,' while an attempt to create the type type rvalue reference to
10420 cv T' creates the type T"
10421 */
10422 r = cp_build_reference_type
10425 else
10430 /* Will this ever be needed for TYPE_..._TO values? */
10434 }
10436 {
10439 {
10440 /* [temp.deduct]
10442 Type deduction may fail for any of the following
10443 reasons:
10445 -- Attempting to create "pointer to member of T" when T
10446 is not a class type. */
10450 }
10452 {
10456 }
10458 {
10462 }
10465 {
10466 /* The type of the implicit object parameter gets its
10467 cv-qualifiers from the FUNCTION_TYPE. */
10468 tree memptr;
10472 complain);
10473 }
10474 else
10477 complain);
10478 }
10481 {
10482 tree fntype;
10483 tree specs;
10488 /* Substitute the exception specification. */
10490 in_decl);
10496 }
10498 {
10503 /* As an optimization, we avoid regenerating the array type if
10504 it will obviously be the same as T. */
10508 /* These checks should match the ones in grokdeclarator.
10510 [temp.deduct]
10512 The deduction may fail for any of the following reasons:
10514 -- Attempting to create an array with an element type that
10515 is void, a function type, or a reference type, or [DR337]
10516 an abstract class type. */
10520 {
10524 }
10526 {
10529 type);
10531 }
10536 {
10539 }
10542 }
10546 {
10555 }
10559 {
10565 }
10568 {
10578 {
10582 }
10584 {
10585 /* Normally, make_typename_type does not require that the CTX
10586 have complete type in order to allow things like:
10588 template <class T> struct S { typename S<T>::X Y; };
10590 But, such constructs have already been resolved by this
10591 point, so here CTX really should have complete type, unless
10592 it's a partial instantiation. */
10596 {
10600 }
10601 }
10608 {
10611 }
10614 {
10621 }
10623 return cp_build_qualified_type_real
10625 }
10628 {
10640 }
10648 {
10656 }
10659 {
10667 }
10670 {
10671 tree type;
10687 complain);
10688 }
10691 {
10692 tree type;
10708 else
10709 type = finish_decltype_type
10714 complain);
10715 }
10719 {
10721 tree packed_out =
10723 args,
10724 complain,
10725 in_decl);
10728 /* For template nontype argument packs, also substitute into
10729 the type. */
10734 }
10740 }
10741 }
10743 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10744 type of the expression on the left-hand side of the "." or "->"
10745 operator. */
10747 static tree
10750 {
10751 tree name;
10752 tree qualifying_scope;
10753 tree fns;
10754 tree optype;
10758 /* A baselink indicates a function from a base class. Both the
10759 BASELINK_ACCESS_BINFO and the base class referenced may
10760 indicate bases of the template class, rather than the
10761 instantiated class. In addition, lookups that were not
10762 ambiguous before may be ambiguous now. Therefore, we perform
10763 the lookup again. */
10770 {
10777 }
10785 /* If lookup found a single function, mark it as used at this
10786 point. (If it lookup found multiple functions the one selected
10787 later by overload resolution will be marked as used at that
10788 point.) */
10794 /* Add back the template arguments, if present. */
10799 template_args);
10800 /* Update the conversion operator type. */
10806 qualifying_scope,
10807 object_type);
10808 }
10810 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10811 true if the qualified-id will be a postfix-expression in-and-of
10812 itself; false if more of the postfix-expression follows the
10813 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10814 of "&". */
10816 static tree
10820 {
10821 tree expr;
10822 tree scope;
10823 tree name;
10825 tree template_args;
10829 /* Figure out what name to look up. */
10832 {
10839 }
10840 else
10841 {
10844 }
10846 /* Substitute into the qualifying scope. When there are no ARGS, we
10847 are just trying to simplify a non-dependent expression. In that
10848 case the qualifying scope may be dependent, and, in any case,
10849 substituting will not help. */
10852 {
10855 }
10856 else
10864 {
10866 {
10867 /* A BIT_NOT_EXPR is used to represent a destructor. */
10869 {
10873 }
10874 else
10877 }
10878 else
10882 {
10884 {
10888 }
10890 }
10891 }
10894 {
10896 scope);
10897 /* Remember that there was a reference to this entity. */
10899 }
10902 {
10908 }
10917 {
10918 expr = (adjust_result_of_qualified_name_lookup
10920 expr = (finish_qualified_id_expr
10924 }
10926 /* Expressions do not generally have reference type. */
10928 /* However, if we're about to form a pointer-to-member, we just
10929 want the referenced member referenced. */
10934 }
10936 /* Like tsubst, but deals with expressions. This function just replaces
10937 template parms; to finish processing the resultant expression, use
10938 tsubst_expr. */
10940 static tree
10942 {
10944 tree r;
10952 {
10957 {
10958 tree c;
10959 /* This can happen for a parameter name used later in a function
10960 declaration (such as in a late-specified return type). Just
10961 make a dummy decl, since it's only used for its type. */
10963 /* We copy T because want to tsubst the PARM_DECL only,
10964 not the following PARM_DECLs that are chained to T. */
10967 /* Give it the template pattern as its context; its true context
10968 hasn't been instantiated yet and this is good enough for
10969 mangling. */
10971 }
10979 {
10980 tree enum_type;
10981 tree v;
10985 /* There is no need to substitute into namespace-scope
10986 enumerators. */
10989 /* If ARGS is NULL, then T is known to be non-dependent. */
10993 /* Unfortunately, we cannot just call lookup_name here.
10994 Consider:
10996 template <int I> int f() {
10997 enum E { a = I };
10998 struct S { void g() { E e = a; } };
10999 };
11001 When we instantiate f<7>::S::g(), say, lookup_name is not
11002 clever enough to find f<7>::a. */
11003 enum_type
11013 /* We didn't find the name. That should never happen; if
11014 name-lookup found it during preliminary parsing, we
11015 should find it again here during instantiation. */
11017 }
11022 {
11023 tree ctx;
11028 {
11031 {
11035 }
11037 }
11038 }
11061 {
11062 /* Template template argument like the following example need
11063 special treatment:
11065 template <template <class> class TT> struct C {};
11066 template <class T> struct D {
11067 template <class U> struct E {};
11068 C<E> c; // #1
11069 };
11070 D<int> d; // #2
11072 We are processing the template argument `E' in #1 for
11073 the template instantiation #2. Originally, `E' is a
11074 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11075 have to substitute this with one having context `D<int>'. */
11079 }
11080 else
11081 /* Ordinary template template argument. */
11090 return build1
11096 {
11097 /* We only want to compute the number of arguments. */
11111 {
11118 else
11121 }
11122 else
11124 }
11125 /* Fall through */
11139 return build1
11144 {
11145 tree object;
11146 tree name;
11151 {
11155 }
11158 {
11168 }
11173 in_decl);
11174 else
11177 }
11215 return build_nt
11228 return build_nt
11235 {
11243 }
11248 {
11249 r = build_nt
11255 }
11258 {
11259 r = build_nt
11265 }
11268 {
11269 r = build_nt
11275 }
11278 {
11279 /* Substituted template arguments */
11288 }
11291 {
11311 }
11336 {
11339 }
11340 else
11344 /* This is handled by tsubst_copy_and_build. */
11349 in_decl),
11353 /* We shouldn't have built any of these during initial template
11354 generation. Instead, they should be built during instantiation
11355 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11359 r = build2
11377 }
11378 }
11380 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11382 static tree
11384 tree in_decl)
11385 {
11389 {
11395 {
11398 {
11404 }
11405 /* FALLTHRU */
11427 }
11428 }
11431 }
11433 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11435 static tree
11437 tree in_decl)
11438 {
11439 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11464 #undef RECUR
11465 }
11467 /* Substitute one OMP_FOR iterator. */
11469 static void
11474 {
11475 #define RECUR(NODE) \
11476 tsubst_expr ((NODE), args, complain, in_decl, \
11477 integral_constant_expression_p)
11486 {
11493 }
11497 {
11503 complain);
11504 else
11511 }
11514 {
11515 tree c;
11517 {
11528 }
11530 {
11535 {
11538 }
11539 }
11540 }
11546 else
11550 {
11561 {
11568 }
11569 else
11575 {
11581 }
11585 {
11592 }
11593 else
11599 }
11605 #undef RECUR
11606 }
11608 /* Like tsubst_copy for expressions, etc. but also does semantic
11609 processing. */
11611 static tree
11614 {
11615 #define RECUR(NODE) \
11616 tsubst_expr ((NODE), args, complain, in_decl, \
11617 integral_constant_expression_p)
11630 {
11632 {
11633 tree_stmt_iterator i;
11637 }
11652 else
11661 {
11662 tree decl;
11663 tree init;
11669 {
11672 tree decl;
11680 else
11682 }
11683 else
11684 {
11688 {
11689 /* By marking the declaration as instantiated, we avoid
11690 trying to instantiate it. Since instantiate_decl can't
11691 handle local variables, and since we've already done
11692 all that needs to be done, that's the right thing to
11693 do. */
11698 /* Anonymous aggregates are a special case. */
11700 else
11701 {
11705 {
11706 /* For __PRETTY_FUNCTION__ we have to adjust the
11707 initializer. */
11711 }
11712 else
11713 {
11717 {
11718 /* If we had an initializer but it
11719 instantiated to nothing,
11720 value-initialize the object. This will
11721 only occur when the initializer was a
11722 pack expansion where the parameter packs
11723 used in that expansion were of length
11724 zero. */
11726 complain);
11729 }
11730 else
11732 }
11735 }
11736 }
11737 }
11739 /* A DECL_EXPR can also be used as an expression, in the condition
11740 clause of an if/for/while construct. */
11742 }
11757 {
11767 }
11794 {
11798 }
11806 else
11814 else
11841 {
11843 tree label;
11848 }
11854 /* Computed goto's must be tsubst'd into. On the other hand,
11855 non-computed gotos must not be; the identifier in question
11856 will have no binding. */
11858 else
11864 tmp = finish_asm_stmt
11871 {
11876 }
11881 {
11886 }
11887 else
11888 {
11893 else
11900 else
11906 else
11908 }
11912 {
11916 {
11918 /* Prevent instantiate_decl from trying to instantiate
11919 this variable. We've already done all that needs to be
11920 done. */
11923 }
11928 }
11936 {
11937 tree condition =
11939 args,
11946 }
11967 {
11982 integral_constant_expression_p);
11991 {
11995 }
11996 else
11997 {
12005 }
12019 }
12050 {
12055 }
12071 integral_constant_expression_p);
12072 }
12075 #undef RECUR
12076 }
12078 /* T is a postfix-expression that is not being used in a function
12079 call. Return the substituted version of T. */
12081 static tree
12083 tsubst_flags_t complain,
12084 tree in_decl)
12085 {
12089 else
12095 }
12097 /* Like tsubst but deals with expressions and performs semantic
12098 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12100 tree
12102 tree args,
12103 tsubst_flags_t complain,
12104 tree in_decl,
12107 {
12108 #define RECUR(NODE) \
12109 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12111 integral_constant_expression_p)
12113 tree op1;
12119 {
12122 /* Fall through. */
12124 {
12125 tree decl;
12126 cp_id_kind idk;
12131 {
12134 }
12136 /* Look up the name. */
12139 /* By convention, expressions use ERROR_MARK_NODE to indicate
12140 failure, not NULL_TREE. */
12146 integral_constant_expression_p,
12154 input_location);
12160 }
12163 {
12164 tree object;
12172 {
12175 }
12176 else
12183 else
12185 }
12188 {
12192 {
12193 /* A type conversion to reference type will be enclosed in
12194 such an indirect ref, but the substitution of the cast
12195 will have also added such an indirect ref. */
12198 }
12199 else
12202 }
12205 return build_nop
12214 {
12215 tree type;
12216 tree op;
12221 {
12226 }
12231 {
12244 }
12245 }
12263 complain);
12270 else
12272 in_decl);
12309 return build_x_binary_op
12313 ? ERROR_MARK
12317 ? ERROR_MARK
12320 complain);
12333 /* Fall through */
12338 {
12339 /* When there are no ARGS, we are trying to evaluate a
12340 non-dependent expression from the parser. Trying to do
12341 the substitutions may not work. */
12344 }
12345 else
12346 {
12354 }
12358 else
12374 {
12375 tree r = build_x_modify_expr
12379 complain);
12380 /* TREE_NO_WARNING must be set if either the expression was
12381 parenthesized or it uses an operator such as >>= rather
12382 than plain assignment. In the former case, it was already
12383 set and must be copied. In the latter case,
12384 build_x_modify_expr sets it and it must not be reset
12385 here. */
12389 }
12394 /* Remember that there was a reference to this entity. */
12400 {
12405 tree ret;
12409 else
12410 {
12414 }
12416 /* If there was an initializer in the original tree, but it
12417 instantiated to an empty list, then we should pass a
12418 non-NULL empty vector to tell build_new that it was an
12419 empty initializer() rather than no initializer. This can
12420 only happen when the initializer is a pack expansion whose
12421 parameter packs are of length zero. */
12424 else
12425 {
12429 else
12430 {
12433 }
12434 }
12441 complain);
12449 }
12452 return delete_sanity
12461 complain);
12464 {
12465 tree function;
12470 tree ret;
12473 /* When we parsed the expression, we determined whether or
12474 not Koenig lookup should be performed. */
12477 {
12482 }
12483 else
12484 {
12486 {
12492 }
12493 else
12497 in_decl,
12499 integral_constant_expression_p);
12503 }
12508 {
12514 else
12515 {
12516 /* Expand the pack expansion and push each entry onto
12517 CALL_ARGS. */
12520 {
12525 {
12530 }
12531 }
12532 else
12533 {
12534 /* A partial substitution. Add one entry. */
12536 }
12537 }
12538 }
12540 /* We do not perform argument-dependent lookup if normal
12541 lookup finds a non-function, in accordance with the
12542 expected resolution of DR 218. */
12545 /* If lookup found a member function, the Koenig lookup is
12546 not appropriate, even if an unqualified-name was used
12547 to denote the function. */
12550 /* Only do this when substitution turns a dependent call
12551 into a non-dependent call. */
12557 {
12561 }
12563 /* Remember that there was a reference to this entity. */
12570 {
12585 complain);
12586 else
12587 ret = (build_new_method_call
12592 complain));
12593 }
12594 else
12597 koenig_p,
12598 complain);
12603 }
12606 return build_x_conditional_expr
12610 complain);
12613 return finish_pseudo_destructor_expr
12619 {
12627 {
12628 /* We have pack expansions, so expand those and
12629 create a new list out of it. */
12632 tree chain;
12635 /* Expand the argument expressions. */
12643 /* Build the rest of the list. */
12648 /* Determine the number of arguments. */
12650 {
12653 }
12656 else
12657 {
12658 /* Since we only performed a partial substitution into
12659 the argument pack, we only return a single list
12660 node. */
12667 }
12669 /* Convert the argument vectors into a TREE_LIST */
12672 {
12673 /* Grab the Ith values. */
12674 i--;
12677 value
12681 /* Build the list (backwards). */
12683 }
12686 }
12702 }
12705 {
12706 tree object;
12707 tree object_type;
12708 tree member;
12712 /* Remember that there was a reference to this entity. */
12722 else
12728 {
12730 {
12735 {
12738 }
12740 {
12744 }
12745 }
12746 }
12749 {
12750 tree tmpl;
12751 tree args;
12753 /* Lookup the template functions now that we know what the
12754 scope is. */
12761 {
12764 args);
12765 member = (adjust_result_of_qualified_name_lookup
12767 object_type));
12768 }
12769 else
12770 {
12772 input_location);
12774 }
12775 }
12779 {
12781 {
12785 else
12788 }
12790 }
12796 complain);
12797 }
12800 return build_throw
12804 {
12812 tree r;
12817 /* digest_init will do the wrong thing if we let it. */
12821 /* We do not want to process the index of aggregate
12822 initializers as they are identifier nodes which will be
12823 looked up by digest_init. */
12829 {
12834 {
12835 /* Substitute into the pack expansion. */
12837 in_decl);
12840 ;
12842 /* Just move the argument into place. */
12844 else
12845 {
12846 /* Update the length of the final CONSTRUCTOR
12847 arguments vector, and note that we will need to
12848 copy.*/
12851 }
12852 }
12853 else
12855 }
12858 {
12863 {
12865 {
12870 }
12871 else
12873 }
12874 }
12883 }
12886 {
12891 }
12896 /* Fall through */
12899 {
12903 /* If the original type was a reference, we'll be wrapped in
12904 the appropriate INDIRECT_REF. */
12907 }
12912 in_decl));
12918 {
12927 }
12930 {
12936 integral_constant_expression_p);
12940 /* If the resulting list of expression statement is empty,
12941 fold it further into void_zero_node. */
12946 }
12950 /* As in finish_id_expression, we resolve enumeration constants
12951 to their underlying values. */
12953 {
12956 }
12960 {
12981 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12983 /* Now that we know visibility, instantiate the type so we have a
12984 declaration of the op() for later calls to lambda_function. */
12992 }
12995 /* Handle Objective-C++ constructs, if appropriate. */
12996 {
12997 tree subst
13002 }
13004 }
13006 #undef RECUR
13007 }
13009 /* Verify that the instantiated ARGS are valid. For type arguments,
13010 make sure that the type's linkage is ok. For non-type arguments,
13011 make sure they are constants if they are integral or enumerations.
13012 Emit an error under control of COMPLAIN, and return TRUE on error. */
13014 static bool
13016 {
13018 {
13028 }
13030 {
13031 /* [basic.link]: A name with no linkage (notably, the name
13032 of a class or enumeration declared in a local scope)
13033 shall not be used to declare an entity with linkage.
13034 This implies that names with no linkage cannot be used as
13035 template arguments
13037 DR 757 relaxes this restriction for C++0x. */
13042 {
13043 /* DR 488 makes use of a type with no linkage cause
13044 type deduction to fail. */
13046 {
13049 else
13052 }
13054 }
13055 /* In order to avoid all sorts of complications, we do not
13056 allow variably-modified types as template arguments. */
13058 {
13062 }
13063 }
13064 /* A non-type argument of integral or enumerated type must be a
13065 constant. */
13069 {
13073 }
13075 }
13077 static bool
13079 {
13084 {
13087 }
13091 }
13093 /* Instantiate the indicated variable or function template TMPL with
13094 the template arguments in TARG_PTR. */
13096 tree
13098 {
13100 tree fndecl;
13101 tree gen_tmpl;
13102 tree spec;
13103 HOST_WIDE_INT saved_processing_template_decl;
13110 /* If this function is a clone, handle it specially. */
13112 {
13113 tree spec;
13114 tree clone;
13116 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13117 DECL_CLONED_FUNCTION. */
13123 /* Look for the clone. */
13127 /* We should always have found the clone by now. */
13130 }
13132 /* Check to see if we already have this specialization. */
13135 /* The TMPL is a partial instantiation. To get a full set of
13136 arguments we must add the arguments used to perform the
13137 partial instantiation. */
13139 targ_ptr);
13141 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13142 but it doesn't seem to be on the hot path. */
13154 complain))
13157 /* We are building a FUNCTION_DECL, during which the access of its
13158 parameters and return types have to be checked. However this
13159 FUNCTION_DECL which is the desired context for access checking
13160 is not built yet. We solve this chicken-and-egg problem by
13161 deferring all checks until we have the FUNCTION_DECL. */
13164 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13165 (because, for example, we have encountered a non-dependent
13166 function call in the body of a template function and must now
13167 determine which of several overloaded functions will be called),
13168 within the instantiation itself we are not processing a
13169 template. */
13172 /* Substitute template parameters to obtain the specialization. */
13179 /* Now we know the specialization, compute access previously
13180 deferred. */
13183 /* Some typedefs referenced from within the template code need to be access
13184 checked at template instantiation time, i.e now. These types were
13185 added to the template at parsing time. Let's get those and perfom
13186 the acces checks then. */
13192 /* The DECL_TI_TEMPLATE should always be the immediate parent
13193 template, not the most general template. */
13196 /* If we've just instantiated the main entry point for a function,
13197 instantiate all the alternate entry points as well. We do this
13198 by cloning the instantiation of the main entry point, not by
13199 instantiating the template clones. */
13204 }
13206 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13207 NARGS elements of the arguments that are being used when calling
13208 it. TARGS is a vector into which the deduced template arguments
13209 are placed.
13211 Return zero for success, 2 for an incomplete match that doesn't resolve
13212 all the types, and 1 for complete failure. An error message will be
13213 printed only for an incomplete match.
13215 If FN is a conversion operator, or we are trying to produce a specific
13216 specialization, RETURN_TYPE is the return type desired.
13218 The EXPLICIT_TARGS are explicit template arguments provided via a
13219 template-id.
13221 The parameter STRICT is one of:
13223 DEDUCE_CALL:
13224 We are deducing arguments for a function call, as in
13225 [temp.deduct.call].
13227 DEDUCE_CONV:
13228 We are deducing arguments for a conversion function, as in
13229 [temp.deduct.conv].
13231 DEDUCE_EXACT:
13232 We are deducing arguments when doing an explicit instantiation
13233 as in [temp.explicit], when determining an explicit specialization
13234 as in [temp.expl.spec], or when taking the address of a function
13235 template, as in [temp.deduct.funcaddr]. */
13237 int
13239 tree explicit_targs,
13240 tree targs,
13243 tree return_type,
13244 unification_kind_t strict,
13246 {
13247 tree parms;
13248 tree fntype;
13256 {
13257 /* [temp.deduct]
13259 The specified template arguments must match the template
13260 parameters in kind (i.e., type, nontype, template), and there
13261 must not be more arguments than there are parameters;
13262 otherwise type deduction fails.
13264 Nontype arguments must match the types of the corresponding
13265 nontype template parameters, or must be convertible to the
13266 types of the corresponding nontype parameters as specified in
13267 _temp.arg.nontype_, otherwise type deduction fails.
13269 All references in the function type of the function template
13270 to the corresponding template parameters are replaced by the
13271 specified template argument values. If a substitution in a
13272 template parameter or in the function type of the function
13273 template results in an invalid type, type deduction fails. */
13276 tree converted_args;
13282 converted_args
13289 /* Substitute the explicit args into the function type. This is
13290 necessary so that, for instance, explicitly declared function
13291 arguments can match null pointed constants. If we were given
13292 an incomplete set of explicit args, we must not do semantic
13293 processing during substitution as we could create partial
13294 instantiations. */
13296 {
13300 /* Dig out the actual parm. */
13303 {
13306 }
13308 {
13311 }
13314 {
13316 tree targ;
13319 /* Mark the argument pack as "incomplete". We could
13320 still deduce more arguments during unification. */
13323 {
13327 }
13329 /* We have some incomplete argument packs. */
13331 }
13332 }
13335 /* Any substitution is guaranteed to be incomplete if there
13336 are incomplete argument packs, because we can still deduce
13337 more arguments. */
13339 else
13349 /* Place the explicitly specified arguments in TARGS. */
13352 }
13354 /* Never do unification on the 'this' parameter. */
13358 {
13367 }
13369 /* We allow incomplete unification without an error message here
13370 because the standard doesn't seem to explicitly prohibit it. Our
13371 callers must be ready to deal with unification failures in any
13372 event. */
13378 {
13381 /* Clear the "incomplete" flags on all argument packs. */
13383 {
13386 {
13389 }
13390 }
13391 }
13393 /* Now that we have bindings for all of the template arguments,
13394 ensure that the arguments deduced for the template template
13395 parameters have compatible template parameter lists. We cannot
13396 check this property before we have deduced all template
13397 arguments, because the template parameter types of a template
13398 template parameter might depend on prior template parameters
13399 deduced after the template template parameter. The following
13400 ill-formed example illustrates this issue:
13402 template<typename T, template<T> class C> void f(C<5>, T);
13404 template<int N> struct X {};
13406 void g() {
13407 f(X<5>(), 5l); // error: template argument deduction fails
13408 }
13410 The template parameter list of 'C' depends on the template type
13411 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13412 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13413 time that we deduce 'C'. */
13415 && !template_template_parm_bindings_ok_p
13420 /* All is well so far. Now, check:
13422 [temp.deduct]
13424 When all template arguments have been deduced, all uses of
13425 template parameters in nondeduced contexts are replaced with
13426 the corresponding deduced argument values. If the
13427 substitution results in an invalid type, as described above,
13428 type deduction fails. */
13429 {
13434 /* If we're looking for an exact match, check that what we got
13435 is indeed an exact match. It might not be if some template
13436 parameters are used in non-deduced contexts. */
13438 {
13441 tree sarg
13448 }
13449 }
13452 }
13454 /* Adjust types before performing type deduction, as described in
13455 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13456 sections are symmetric. PARM is the type of a function parameter
13457 or the return type of the conversion function. ARG is the type of
13458 the argument passed to the call, or the type of the value
13459 initialized with the result of the conversion function.
13460 ARG_EXPR is the original argument expression, which may be null. */
13462 static int
13466 tree arg_expr)
13467 {
13471 {
13476 {
13477 /* Swap PARM and ARG throughout the remainder of this
13478 function; the handling is precisely symmetric since PARM
13479 will initialize ARG rather than vice versa. */
13484 }
13487 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13488 too, but here handle it by stripping the reference from PARM
13489 rather than by adding it to ARG. */
13497 /* Nothing else to do in this case. */
13502 }
13505 {
13506 /* [temp.deduct.call]
13508 If P is not a reference type:
13510 --If A is an array type, the pointer type produced by the
13511 array-to-pointer standard conversion (_conv.array_) is
13512 used in place of A for type deduction; otherwise,
13514 --If A is a function type, the pointer type produced by
13515 the function-to-pointer standard conversion
13516 (_conv.func_) is used in place of A for type deduction;
13517 otherwise,
13519 --If A is a cv-qualified type, the top level
13520 cv-qualifiers of A's type are ignored for type
13521 deduction. */
13526 else
13528 }
13530 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13531 of the form T&&, where T is a template parameter, and the argument
13532 is an lvalue, T is deduced as A& */
13540 /* [temp.deduct.call]
13542 If P is a cv-qualified type, the top level cv-qualifiers
13543 of P's type are ignored for type deduction. If P is a
13544 reference type, the type referred to by P is used for
13545 type deduction. */
13548 {
13551 }
13553 /* DR 322. For conversion deduction, remove a reference type on parm
13554 too (which has been swapped into ARG). */
13559 }
13561 /* Most parms like fn_type_unification.
13563 If SUBR is 1, we're being called recursively (to unify the
13564 arguments of a function or method parameter of a function
13565 template). */
13567 static int
13569 tree targs,
13570 tree xparms,
13574 unification_kind_t strict,
13576 {
13582 tree parms;
13591 /* Reset the number of non-defaulted template arguments contained
13592 in in TARGS. */
13596 {
13612 }
13614 again:
13622 {
13635 /* We can't deduce anything from this, but we might get all the
13636 template args from other function args. */
13639 /* Conversions will be performed on a function argument that
13640 corresponds with a function parameter that contains only
13641 non-deducible template parameters and explicitly specified
13642 template parameters. */
13644 {
13645 tree type;
13649 else
13656 flags))
13660 }
13663 {
13666 {
13667 /* [temp.deduct.type]
13669 A template-argument can be deduced from a pointer to
13670 function or pointer to member function argument if
13671 the set of overloaded functions does not contain
13672 function templates and at most one of a set of
13673 overloaded functions provides a unique match. */
13679 }
13684 }
13686 {
13691 arg_expr);
13697 }
13698 }
13704 {
13705 /* Unify the remaining arguments with the pack expansion type. */
13706 tree argvec;
13709 /* Allocate a TREE_VEC and copy in all of the arguments */
13714 /* Copy the parameter into parmvec. */
13720 /* Advance to the end of the list of parameters. */
13722 }
13724 /* Fail if we've reached the end of the parm list, and more args
13725 are present, and the parm list isn't variadic. */
13728 /* Fail if parms are left and they don't have default values. */
13736 {
13737 tree tparm;
13744 /* If this is an undeduced nontype parameter that depends on
13745 a type parameter, try another pass; its type may have been
13746 deduced from a later argument than the one from which
13747 this parameter can be deduced. */
13753 /* Core issue #226 (C++0x) [temp.deduct]:
13755 If a template argument has not been deduced, its
13756 default template argument, if any, is used.
13758 When we are in C++98 mode, TREE_PURPOSE will either
13759 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13760 to explicitly check cxx_dialect here. */
13762 {
13770 else
13771 {
13773 /* The position of the first default template argument,
13774 is also the number of non-defaulted arguments in TARGS.
13775 Record that. */
13779 }
13780 }
13782 /* If the type parameter is a parameter pack, then it will
13783 be deduced to an empty parameter pack. */
13785 {
13786 tree arg;
13789 {
13793 }
13794 else
13801 }
13804 }
13805 #ifdef ENABLE_CHECKING
13808 #endif
13811 }
13813 /* Subroutine of type_unification_real. Args are like the variables
13814 at the call site. ARG is an overloaded function (or template-id);
13815 we try deducing template args from each of the overloads, and if
13816 only one succeeds, we go with that. Modifies TARGS and returns
13817 true on success. */
13819 static bool
13821 tree targs,
13822 tree parm,
13823 tree arg,
13824 unification_kind_t strict,
13826 {
13833 {
13836 }
13837 else
13841 /* Handle `&x' where `x' is some static or non-static member
13842 function name. */
13848 /* Strip baselink information. */
13853 {
13854 /* If we got some explicit template args, we need to plug them into
13855 the affected templates before we try to unify, in case the
13856 explicit args will completely resolve the templates in question. */
13862 {
13873 {
13878 {
13881 }
13882 }
13884 }
13885 }
13888 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13889 -- but the deduction does not succeed because the expression is
13890 not just the function on its own. */
13892 else
13898 {
13901 }
13903 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13904 to function or pointer to member function argument if the set of
13905 overloaded functions does not contain function templates and at most
13906 one of a set of overloaded functions provides a unique match.
13908 So if we found multiple possibilities, we return success but don't
13909 deduce anything. */
13912 {
13917 }
13922 }
13924 /* Core DR 115: In contexts where deduction is done and fails, or in
13925 contexts where deduction is not done, if a template argument list is
13926 specified and it, along with any default template arguments, identifies
13927 a single function template specialization, then the template-id is an
13928 lvalue for the function template specialization. */
13930 tree
13932 {
13945 {
13948 }
13950 {
13953 }
13955 {
13958 }
13961 {
13965 /* If we got some explicit template args, we need to plug them into
13966 the affected templates before we try to unify, in case the
13967 explicit args will completely resolve the templates in question. */
13975 {
13986 {
13989 {
13992 }
13994 {
13997 }
13998 }
14000 }
14002 {
14014 }
14016 /* There were no good options and at least one bad one, so let the
14017 user know what the problem is. */
14019 }
14021 }
14023 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14024 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14025 different overloads deduce different arguments for a given parm.
14026 ADDR_P is true if the expression for which deduction is being
14027 performed was of the form "& fn" rather than simply "fn".
14029 Returns 1 on success. */
14031 static int
14033 tree orig_targs,
14034 tree targs,
14035 tree parm,
14036 tree arg,
14037 unification_kind_t strict,
14040 {
14042 tree tempargs;
14045 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14046 to function or pointer to member function argument if the set of
14047 overloaded functions does not contain function templates and at most
14048 one of a set of overloaded functions provides a unique match.
14050 So if this is a template, just return success. */
14062 /* We don't copy orig_targs for this because if we have already deduced
14063 some template args from previous args, unify would complain when we
14064 try to deduce a template parameter for the same argument, even though
14065 there isn't really a conflict. */
14072 /* First make sure we didn't deduce anything that conflicts with
14073 explicitly specified args. */
14075 {
14082 /* Since we're unifying against ourselves, we will fill in
14083 template args used in the function parm list with our own
14084 template parms. Discard them. */
14088 }
14091 {
14096 }
14099 }
14101 /* PARM is a template class (perhaps with unbound template
14102 parameters). ARG is a fully instantiated type. If ARG can be
14103 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14104 TARGS are as for unify. */
14106 static tree
14108 {
14109 tree copy_of_targs;
14116 /* We need to make a new template argument vector for the call to
14117 unify. If we used TARGS, we'd clutter it up with the result of
14118 the attempted unification, even if this class didn't work out.
14119 We also don't want to commit ourselves to all the unifications
14120 we've already done, since unification is supposed to be done on
14121 an argument-by-argument basis. In other words, consider the
14122 following pathological case:
14124 template <int I, int J, int K>
14125 struct S {};
14127 template <int I, int J>
14128 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14130 template <int I, int J, int K>
14131 void f(S<I, J, K>, S<I, I, I>);
14133 void g() {
14134 S<0, 0, 0> s0;
14135 S<0, 1, 2> s2;
14137 f(s0, s2);
14138 }
14140 Now, by the time we consider the unification involving `s2', we
14141 already know that we must have `f<0, 0, 0>'. But, even though
14142 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14143 because there are two ways to unify base classes of S<0, 1, 2>
14144 with S<I, I, I>. If we kept the already deduced knowledge, we
14145 would reject the possibility I=1. */
14148 /* If unification failed, we're done. */
14154 }
14156 /* Given a template type PARM and a class type ARG, find the unique
14157 base type in ARG that is an instance of PARM. We do not examine
14158 ARG itself; only its base-classes. If there is not exactly one
14159 appropriate base class, return NULL_TREE. PARM may be the type of
14160 a partial specialization, as well as a plain template type. Used
14161 by unify. */
14163 static tree
14165 {
14167 tree binfo;
14173 /* The type could not be completed. */
14176 /* Walk in inheritance graph order. The search order is not
14177 important, and this avoids multiple walks of virtual bases. */
14179 {
14183 {
14184 /* If there is more than one satisfactory baseclass, then:
14186 [temp.deduct.call]
14188 If they yield more than one possible deduced A, the type
14189 deduction fails.
14191 applies. */
14196 }
14197 }
14200 }
14202 /* Returns the level of DECL, which declares a template parameter. */
14204 static int
14206 {
14208 {
14218 }
14220 }
14222 /* Decide whether ARG can be unified with PARM, considering only the
14223 cv-qualifiers of each type, given STRICT as documented for unify.
14224 Returns nonzero iff the unification is OK on that basis. */
14226 static int
14228 {
14234 {
14235 /* Although a CVR qualifier is ignored when being applied to a
14236 substituted template parameter ([8.3.2]/1 for example), that
14237 does not allow us to unify "const T" with "int&" because both
14238 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14239 It is ok when we're allowing additional CV qualifiers
14240 at the outer level [14.8.2.1]/3,1st bullet. */
14250 }
14261 }
14263 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14264 void
14266 {
14270 {
14273 }
14274 else
14275 {
14278 }
14279 }
14281 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14282 expansion at the end of PACKED_PARMS. Returns 0 if the type
14283 deduction succeeds, 1 otherwise. STRICT is the same as in
14284 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14285 call argument list. We'll need to adjust the arguments to make them
14286 types. SUBR tells us if this is from a recursive call to
14287 type_unification_real. */
14288 int
14292 {
14293 tree parm
14300 /* Determine the parameter packs we will be deducing from the
14301 pattern, and record their current deductions. */
14304 {
14308 /* Determine the index and level of this parameter pack. */
14311 /* Keep track of the parameter packs and their corresponding
14312 argument packs. */
14315 }
14317 /* Loop through all of the arguments that have not yet been
14318 unified and unify each with the pattern. */
14320 {
14323 /* For each parameter pack, clear out the deduced value so that
14324 we can deduce it again. */
14326 {
14331 }
14333 /* Unify the pattern with the current argument. */
14334 {
14341 {
14344 /* This mirrors what we do in type_unification_real. */
14346 {
14348 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14349 | UNIFY_ALLOW_MORE_CV_QUAL
14363 }
14366 {
14369 {
14370 /* [temp.deduct.type] A template-argument can be
14371 deduced from a pointer to function or pointer
14372 to member function argument if the set of
14373 overloaded functions does not contain function
14374 templates and at most one of a set of
14375 overloaded functions provides a unique
14376 match. */
14381 sub_strict)
14385 }
14388 {
14393 }
14394 }
14399 arg_strict |=
14402 }
14405 {
14406 /* For deduction from an init-list we need the actual list. */
14411 }
14412 }
14414 /* For each parameter pack, collect the deduced value. */
14416 {
14422 }
14423 }
14425 /* Verify that the results of unification with the parameter packs
14426 produce results consistent with what we've seen before, and make
14427 the deduced argument packs available. */
14429 {
14436 /* By default keep the original deduced argument pack.
14437 If necessary, more specific code is going to update the
14438 resulting deduced argument later down in this function. */
14442 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14443 actually deduce anything. */
14451 {
14452 /* Prepend the explicit arguments onto NEW_ARGS. */
14458 /* Copy the explicit arguments. */
14463 /* Copy the deduced arguments. */
14467 }
14470 {
14471 tree result;
14472 /* Build the deduced *_ARGUMENT_PACK. */
14474 {
14479 }
14480 else
14485 /* Note the deduced argument packs for this parameter
14486 pack. */
14488 }
14492 {
14493 /* We only had the explicitly-provided arguments before, but
14494 now we have a complete set of arguments. */
14500 }
14502 new_args))
14503 /* Inconsistent unification of this parameter pack. */
14505 }
14508 }
14510 /* Deduce the value of template parameters. TPARMS is the (innermost)
14511 set of template parameters to a template. TARGS is the bindings
14512 for those template parameters, as determined thus far; TARGS may
14513 include template arguments for outer levels of template parameters
14514 as well. PARM is a parameter to a template function, or a
14515 subcomponent of that parameter; ARG is the corresponding argument.
14516 This function attempts to match PARM with ARG in a manner
14517 consistent with the existing assignments in TARGS. If more values
14518 are deduced, then TARGS is updated.
14520 Returns 0 if the type deduction succeeds, 1 otherwise. The
14521 parameter STRICT is a bitwise or of the following flags:
14523 UNIFY_ALLOW_NONE:
14524 Require an exact match between PARM and ARG.
14525 UNIFY_ALLOW_MORE_CV_QUAL:
14526 Allow the deduced ARG to be more cv-qualified (by qualification
14527 conversion) than ARG.
14528 UNIFY_ALLOW_LESS_CV_QUAL:
14529 Allow the deduced ARG to be less cv-qualified than ARG.
14530 UNIFY_ALLOW_DERIVED:
14531 Allow the deduced ARG to be a template base class of ARG,
14532 or a pointer to a template base class of the type pointed to by
14533 ARG.
14534 UNIFY_ALLOW_INTEGER:
14535 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14536 case for more information.
14537 UNIFY_ALLOW_OUTER_LEVEL:
14538 This is the outermost level of a deduction. Used to determine validity
14539 of qualification conversions. A valid qualification conversion must
14540 have const qualified pointers leading up to the inner type which
14541 requires additional CV quals, except at the outer level, where const
14542 is not required [conv.qual]. It would be normal to set this flag in
14543 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14544 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14545 This is the outermost level of a deduction, and PARM can be more CV
14546 qualified at this point.
14547 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14548 This is the outermost level of a deduction, and PARM can be less CV
14549 qualified at this point. */
14551 static int
14553 {
14555 tree targ;
14556 tree tparm;
14559 /* I don't think this will do the right thing with respect to types.
14560 But the only case I've seen it in so far has been array bounds, where
14561 signedness is the only information lost, and I think that will be
14562 okay. */
14570 /* We can't deduce anything from this, but we might get all the
14571 template args from other function args. */
14574 /* If PARM uses template parameters, then we can't bail out here,
14575 even if ARG == PARM, since we won't record unifications for the
14576 template parameters. We might need them if we're trying to
14577 figure out which of two things is more specialized. */
14581 /* Handle init lists early, so the rest of the function can assume
14582 we're dealing with a type. */
14584 {
14589 /* Replace T with std::initializer_list<T> for deduction. */
14595 /* We can only deduce from an initializer list argument if the
14596 parameter is std::initializer_list; otherwise this is a
14597 non-deduced context. */
14603 {
14610 {
14612 /* It should only be possible to get here for a call. */
14614 elt_strict |= maybe_adjust_types_for_deduction
14617 }
14621 }
14623 /* If the std::initializer_list<T> deduction worked, replace the
14624 deduced A with std::initializer_list<A>. */
14626 {
14631 }
14633 }
14635 /* Immediately reject some pairs that won't unify because of
14636 cv-qualification mismatches. */
14639 /* It is the elements of the array which hold the cv quals of an array
14640 type, and the elements might be template type parms. We'll check
14641 when we recurse. */
14643 /* We check the cv-qualifiers when unifying with template type
14644 parameters below. We want to allow ARG `const T' to unify with
14645 PARM `T' for example, when computing which of two templates
14646 is more specialized, for example. */
14660 {
14664 /* In a type which contains a nested-name-specifier, template
14665 argument values cannot be deduced for template parameters used
14666 within the nested-name-specifier. */
14678 /* The PARM is not one we're trying to unify. Just check
14679 to see if it matches ARG. */
14686 /* Check for mixed types and values. */
14694 {
14695 /* ARG must be constructed from a template class or a template
14696 template parameter. */
14701 {
14704 tree parm_parms
14705 = DECL_INNERMOST_TEMPLATE_PARMS
14710 /* The resolution to DR150 makes clear that default
14711 arguments for an N-argument may not be used to bind T
14712 to a template template parameter with fewer than N
14713 parameters. It is not safe to permit the binding of
14714 default arguments as an extension, as that may change
14715 the meaning of a conforming program. Consider:
14717 struct Dense { static const unsigned int dim = 1; };
14719 template <template <typename> class View,
14720 typename Block>
14721 void operator+(float, View<Block> const&);
14723 template <typename Block,
14724 unsigned int Dim = Block::dim>
14725 struct Lvalue_proxy { operator float() const; };
14727 void
14728 test_1d (void) {
14729 Lvalue_proxy<Dense> p;
14730 float b;
14731 b + p;
14732 }
14734 Here, if Lvalue_proxy is permitted to bind to View, then
14735 the global operator+ will be used; if they are not, the
14736 Lvalue_proxy will be converted to float. */
14738 argvec,
14740 tf_none,
14746 /* Deduce arguments T, i from TT<T> or TT<i>.
14747 We check each element of PARMVEC and ARGVEC individually
14748 rather than the whole TREE_VEC since they can have
14749 different number of elements. */
14756 /* Check if the parameters end in a pack, making them
14757 variadic. */
14766 {
14770 UNIFY_ALLOW_NONE))
14772 }
14777 UNIFY_ALLOW_NONE,
14781 }
14784 /* Fall through to deduce template name. */
14785 }
14789 {
14790 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14792 /* Simple cases: Value already set, does match or doesn't. */
14797 }
14798 else
14799 {
14800 /* If PARM is `const T' and ARG is only `int', we don't have
14801 a match unless we are allowing additional qualification.
14802 If ARG is `const int' and PARM is just `T' that's OK;
14803 that binds `const int' to `T'. */
14808 /* Consider the case where ARG is `const volatile int' and
14809 PARM is `const T'. Then, T should be `volatile int'. */
14810 arg = cp_build_qualified_type_real
14815 /* Simple cases: Value already set, does match or doesn't. */
14821 /* Make sure that ARG is not a variable-sized array. (Note
14822 that were talking about variable-sized arrays (like
14823 `int[n]'), rather than arrays of unknown size (like
14824 `int[]').) We'll get very confused by such a type since
14825 the bound of the array will not be computable in an
14826 instantiation. Besides, such types are not allowed in
14827 ISO C++, so we can do as we please here. */
14831 /* Strip typedefs as in convert_template_argument. */
14833 }
14835 /* If ARG is a parameter pack or an expansion, we cannot unify
14836 against it unless PARM is also a parameter pack. */
14841 /* If the argument deduction results is a METHOD_TYPE,
14842 then there is a problem.
14843 METHOD_TYPE doesn't map to any real C++ type the result of
14844 the deduction can not be of that type. */
14858 /* The PARM is not one we're trying to unify. Just check
14859 to see if it matches ARG. */
14869 /* [temp.deduct.type] If, in the declaration of a function template
14870 with a non-type template-parameter, the non-type
14871 template-parameter is used in an expression in the function
14872 parameter-list and, if the corresponding template-argument is
14873 deduced, the template-argument type shall match the type of the
14874 template-parameter exactly, except that a template-argument
14875 deduced from an array bound may be of any integral type.
14876 The non-type parameter might use already deduced type parameters. */
14879 /* Template-parameter dependent expression. Just accept it for now.
14880 It will later be processed in convert_template_argument. */
14881 ;
14887 /* Convert the ARG to the type of PARM; the deduced non-type
14888 template argument must exactly match the types of the
14889 corresponding parameter. */
14892 /* We haven't deduced the type of this parameter yet. Try again
14893 later. */
14895 else
14898 /* If ARG is a parameter pack or an expansion, we cannot unify
14899 against it unless PARM is also a parameter pack. */
14908 {
14909 /* A pointer-to-member constant can be unified only with
14910 another constant. */
14914 /* Just unify the class member. It would be useless (and possibly
14915 wrong, depending on the strict flags) to unify also
14916 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14917 arg refer to the same variable, even if through different
14918 classes. For instance:
14920 struct A { int x; };
14921 struct B : A { };
14923 Unification of &A::x and &B::x must succeed. */
14926 }
14929 {
14933 /* [temp.deduct.call]
14935 A can be another pointer or pointer to member type that can
14936 be converted to the deduced A via a qualification
14937 conversion (_conv.qual_).
14939 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14940 This will allow for additional cv-qualification of the
14941 pointed-to types if appropriate. */
14944 /* The derived-to-base conversion only persists through one
14945 level of pointers. */
14950 }
14965 {
14966 tree parm_max;
14967 tree arg_max;
14971 /* Our representation of array types uses "N - 1" as the
14972 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14973 not an integer constant. We cannot unify arbitrarily
14974 complex expressions, so we eliminate the MINUS_EXPRs
14975 here. */
14979 {
14982 }
14986 {
14987 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14988 trying to unify the type of a variable with the type
14989 of a template parameter. For example:
14991 template <unsigned int N>
14992 void f (char (&) [N]);
14993 int g();
14994 void h(int i) {
14995 char a[g(i)];
14996 f(a);
14997 }
14999 Here, the type of the ARG will be "int [g(i)]", and
15000 may be a SAVE_EXPR, etc. */
15004 }
15006 /* If only one of the bounds used a MINUS_EXPR, compensate
15007 by adding one to the other bound. */
15010 integer_type_node,
15011 parm_max,
15012 integer_one_node);
15015 integer_type_node,
15016 arg_max,
15017 integer_one_node);
15021 }
15035 /* We have already checked cv-qualification at the top of the
15036 function. */
15040 /* As far as unification is concerned, this wins. Later checks
15041 will invalidate it if necessary. */
15044 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15045 /* Type INTEGER_CST can come from ordinary constant template args. */
15055 {
15064 UNIFY_ALLOW_NONE))
15067 }
15075 {
15082 strict);
15083 }
15086 {
15090 {
15091 /* First, we try to unify the PARM and ARG directly. */
15096 {
15097 /* Fallback to the special case allowed in
15098 [temp.deduct.call]:
15100 If P is a class, and P has the form
15101 template-id, then A can be a derived class of
15102 the deduced A. Likewise, if P is a pointer to
15103 a class of the form template-id, A can be a
15104 pointer to a derived class pointed to by the
15105 deduced A. */
15110 }
15111 }
15115 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15116 Then, we should unify `int' and `U'. */
15118 else
15119 /* There's no chance of unification succeeding. */
15124 }
15131 {
15134 tree a;
15140 /* CV qualifications for methods can never be deduced, they must
15141 match exactly. We need to check them explicitly here,
15142 because type_unification_real treats them as any other
15143 cv-qualified parameter. */
15145 && (!check_cv_quals_for_unify
15165 LOOKUP_NORMAL);
15166 }
15169 /* Unify a pointer to member with a pointer to member function, which
15170 deduces the type of the member as a function type. */
15172 {
15173 tree method_type;
15174 tree fntype;
15176 /* Check top-level cv qualifiers */
15184 /* Determine the type of the function we are unifying against. */
15186 fntype =
15190 /* Extract the cv-qualifiers of the member function from the
15191 implicit object parameter and place them on the function
15192 type to be restored later. */
15195 }
15203 strict);
15214 /* Matched cases are handled by the ARG == PARM test above. */
15218 /* A non-type template parameter that is a variable should be a
15219 an integral constant, in which case, it whould have been
15220 folded into its (constant) value. So we should not be getting
15221 a variable here. */
15226 {
15234 {
15236 {
15238 /* We can unify against something with a trailing
15239 parameter pack. */
15241 else
15242 /* Since there is something following the pack
15243 expansion, we cannot unify this template argument
15244 list. */
15246 }
15247 }
15250 /* If we don't have enough arguments to satisfy the parameters
15251 (not counting the pack expression at the end), or we have
15252 too many arguments for a parameter list that doesn't end in
15253 a pack expression, we can't unify. */
15258 /* Unify all of the parameters that precede the (optional)
15259 pack expression. */
15261 {
15265 }
15273 }
15279 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15280 nodes. */
15284 /* Unification fails if we hit an error node. */
15290 /* We must be looking at an expression. This can happen with
15291 something like:
15293 template <int I>
15294 void foo(S<I>, S<I + 2>);
15296 This is a "nondeduced context":
15298 [deduct.type]
15300 The nondeduced contexts are:
15302 --A type that is a template-id in which one or more of
15303 the template-arguments is an expression that references
15304 a template-parameter.
15306 In these cases, we assume deduction succeeded, but don't
15307 actually infer any unifications. */
15312 else
15314 }
15315 }
15316 \f
15317 /* Note that DECL can be defined in this translation unit, if
15318 required. */
15320 static void
15322 {
15323 tree clone;
15327 }
15329 /* Called if RESULT is explicitly instantiated, or is a member of an
15330 explicitly instantiated class. */
15332 void
15334 {
15337 /* If this entity has already been written out, it's too late to
15338 make any modifications. */
15343 /* The TREE_PUBLIC flag for function declarations will have been
15344 set correctly by tsubst. */
15347 /* This might have been set by an earlier implicit instantiation. */
15352 else
15353 {
15355 /* Always make artificials weak. */
15358 /* For WIN32 we also want to put explicit instantiations in
15359 linkonce sections. */
15362 }
15364 /* If EXTERN_P, then this function will not be emitted -- unless
15365 followed by an explicit instantiation, at which point its linkage
15366 will be adjusted. If !EXTERN_P, then this function will be
15367 emitted here. In neither circumstance do we want
15368 import_export_decl to adjust the linkage. */
15370 }
15372 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15373 important template arguments. If any are missing, we check whether
15374 they're important by using error_mark_node for substituting into any
15375 args that were used for partial ordering (the ones between ARGS and END)
15376 and seeing if it bubbles up. */
15378 static bool
15380 {
15385 {
15388 }
15390 {
15392 {
15396 }
15397 }
15399 }
15401 /* Given two function templates PAT1 and PAT2, return:
15403 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15404 -1 if PAT2 is more specialized than PAT1.
15405 0 if neither is more specialized.
15407 LEN indicates the number of parameters we should consider
15408 (defaulted parameters should not be considered).
15410 The 1998 std underspecified function template partial ordering, and
15411 DR214 addresses the issue. We take pairs of arguments, one from
15412 each of the templates, and deduce them against each other. One of
15413 the templates will be more specialized if all the *other*
15414 template's arguments deduce against its arguments and at least one
15415 of its arguments *does* *not* deduce against the other template's
15416 corresponding argument. Deduction is done as for class templates.
15417 The arguments used in deduction have reference and top level cv
15418 qualifiers removed. Iff both arguments were originally reference
15419 types *and* deduction succeeds in both directions, the template
15420 with the more cv-qualified argument wins for that pairing (if
15421 neither is more cv-qualified, they both are equal). Unlike regular
15422 deduction, after all the arguments have been deduced in this way,
15423 we do *not* verify the deduced template argument values can be
15424 substituted into non-deduced contexts.
15426 The logic can be a bit confusing here, because we look at deduce1 and
15427 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15428 can find template arguments for pat1 to make arg1 look like arg2, that
15429 means that arg2 is at least as specialized as arg1. */
15431 int
15433 {
15446 /* Remove the this parameter from non-static member functions. If
15447 one is a non-static member function and the other is not a static
15448 member function, remove the first parameter from that function
15449 also. This situation occurs for operator functions where we
15450 locate both a member function (with this pointer) and non-member
15451 operator (with explicit first operand). */
15453 {
15458 }
15460 {
15463 {
15464 len--;
15466 }
15467 }
15469 /* If only one is a conversion operator, they are unordered. */
15473 /* Consider the return type for a conversion function */
15475 {
15478 len++;
15479 }
15481 processing_template_decl++;
15487 /* Stop when an ellipsis is seen. */
15489 {
15498 {
15499 /* When both arguments are pack expansions, we need only
15500 unify the patterns themselves. */
15504 /* This is the last comparison we need to do. */
15506 }
15509 {
15512 }
15515 {
15518 }
15521 {
15522 /* Only of the args is a reference, see if we should apply
15523 array/function pointer decay to it. This is not part of
15524 DR214, but is, IMHO, consistent with the deduction rules
15525 for the function call itself, and with our earlier
15526 implementation of the underspecified partial ordering
15527 rules. (nathan). */
15529 {
15531 {
15534 /* FALLTHROUGH. */
15541 }
15542 }
15543 else
15544 {
15546 {
15549 /* FALLTHROUGH. */
15556 }
15557 }
15558 }
15564 {
15570 /* Setup the parameter vector, which contains only ARG1. */
15573 /* Setup the argument vector, which contains the remaining
15574 arguments. */
15583 /* We cannot deduce in the other direction, because ARG1 is
15584 a pack expansion but ARG2 is not. */
15586 }
15588 {
15594 /* Setup the parameter vector, which contains only ARG1. */
15597 /* Setup the argument vector, which contains the remaining
15598 arguments. */
15607 /* We cannot deduce in the other direction, because ARG2 is
15608 a pack expansion but ARG1 is not.*/
15610 }
15612 else
15613 {
15614 /* The normal case, where neither argument is a pack
15615 expansion. */
15618 }
15620 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15621 arg2, then arg2 is not as specialized as arg1. */
15627 /* "If, for a given type, deduction succeeds in both directions
15628 (i.e., the types are identical after the transformations above)
15629 and if the type from the argument template is more cv-qualified
15630 than the type from the parameter template (as described above)
15631 that type is considered to be more specialized than the other. If
15632 neither type is more cv-qualified than the other then neither type
15633 is more specialized than the other." */
15637 {
15642 }
15645 /* We've failed to deduce something in either direction.
15646 These must be unordered. */
15651 /* We have already processed all of the arguments in our
15652 handing of the pack expansion type. */
15657 }
15659 /* "In most cases, all template parameters must have values in order for
15660 deduction to succeed, but for partial ordering purposes a template
15661 parameter may remain without a value provided it is not used in the
15662 types being used for partial ordering."
15664 Thus, if we are missing any of the targs1 we need to substitute into
15665 origs1, then pat2 is not as specialized as pat1. This can happen when
15666 there is a nondeduced context. */
15672 processing_template_decl--;
15674 /* All things being equal, if the next argument is a pack expansion
15675 for one function but not for the other, prefer the
15676 non-variadic function. FIXME this is bogus; see c++/41958. */
15680 {
15683 }
15689 else
15691 }
15693 /* Determine which of two partial specializations is more specialized.
15695 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15696 to the first partial specialization. The TREE_VALUE is the
15697 innermost set of template parameters for the partial
15698 specialization. PAT2 is similar, but for the second template.
15700 Return 1 if the first partial specialization is more specialized;
15701 -1 if the second is more specialized; 0 if neither is more
15702 specialized.
15704 See [temp.class.order] for information about determining which of
15705 two templates is more specialized. */
15707 static int
15709 {
15710 tree targs;
15718 /* Just like what happens for functions, if we are ordering between
15719 different class template specializations, we may encounter dependent
15720 types in the arguments, and we need our dependency check functions
15721 to behave correctly. */
15727 {
15730 }
15736 {
15739 }
15742 /* In the case of a tie where at least one of the class templates
15743 has a parameter pack at the end, the template with the most
15744 non-packed parameters wins. */
15746 && any_deductions
15749 {
15755 /* We don't count the pack expansion at the end. */
15765 }
15768 }
15770 /* Return the template arguments that will produce the function signature
15771 DECL from the function template FN, with the explicit template
15772 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15773 also match. Return NULL_TREE if no satisfactory arguments could be
15774 found. */
15776 static tree
15778 {
15781 tree decl_type;
15782 tree decl_arg_types;
15785 tree arg;
15787 /* Substitute the explicit template arguments into the type of DECL.
15788 The call to fn_type_unification will handle substitution into the
15789 FN. */
15792 {
15793 tree tmpl;
15794 tree converted_args;
15798 else
15799 /* We can get here for some invalid specializations. */
15802 converted_args
15805 tf_none,
15814 }
15816 /* Never do unification on the 'this' parameter. */
15835 }
15837 /* Return the innermost template arguments that, when applied to a
15838 template specialization whose innermost template parameters are
15839 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15840 ARGS.
15842 For example, suppose we have:
15844 template <class T, class U> struct S {};
15845 template <class T> struct S<T*, int> {};
15847 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15848 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15849 int}. The resulting vector will be {double}, indicating that `T'
15850 is bound to `double'. */
15852 static tree
15854 {
15856 tree deduced_args;
15857 tree innermost_deduced_args;
15861 {
15865 innermost_deduced_args);
15866 }
15867 else
15873 UNIFY_ALLOW_NONE))
15880 /* Verify that nondeduced template arguments agree with the type
15881 obtained from argument deduction.
15883 For example:
15885 struct A { typedef int X; };
15886 template <class T, class U> struct C {};
15887 template <class T> struct C<T, typename T::X> {};
15889 Then with the instantiation `C<A, int>', we can deduce that
15890 `T' is `A' but unify () does not check whether `typename T::X'
15891 is `int'. */
15894 /* We only need to check the innermost arguments; the other
15895 arguments will always agree. */
15900 /* Now that we have bindings for all of the template arguments,
15901 ensure that the arguments deduced for the template template
15902 parameters have compatible template parameter lists. See the use
15903 of template_template_parm_bindings_ok_p in fn_type_unification
15904 for more information. */
15909 }
15911 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15912 Return the TREE_LIST node with the most specialized template, if
15913 any. If there is no most specialized template, the error_mark_node
15914 is returned.
15916 Note that this function does not look at, or modify, the
15917 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15918 returned is one of the elements of INSTANTIATIONS, callers may
15919 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15920 and retrieve it from the value returned. */
15922 tree
15924 {
15931 {
15937 fate--;
15942 fate++;
15947 {
15948 /* Equally specialized, move to next function. If there
15949 is no next function, nothing's most specialized. */
15954 }
15955 }
15958 /* Now verify that champ is better than everything earlier in the
15959 instantiation list. */
15967 {
15970 }
15972 processing_template_decl--;
15978 }
15980 /* If DECL is a specialization of some template, return the most
15981 general such template. Otherwise, returns NULL_TREE.
15983 For example, given:
15985 template <class T> struct S { template <class U> void f(U); };
15987 if TMPL is `template <class U> void S<int>::f(U)' this will return
15988 the full template. This function will not trace past partial
15989 specializations, however. For example, given in addition:
15991 template <class T> struct S<T*> { template <class U> void f(U); };
15993 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15994 `template <class T> template <class U> S<T*>::f(U)'. */
15996 tree
15998 {
15999 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16000 an immediate specialization. */
16002 {
16006 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16007 template friend. */
16012 }
16014 /* Look for more and more general templates. */
16016 {
16017 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16018 (See cp-tree.h for details.) */
16026 /* Stop if we run into an explicitly specialized class template. */
16033 }
16036 }
16038 /* Return the most specialized of the class template partial
16039 specializations of TMPL which can produce TYPE, a specialization of
16040 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16041 a _TYPE node corresponding to the partial specialization, while the
16042 TREE_PURPOSE is the set of template arguments that must be
16043 substituted into the TREE_TYPE in order to generate TYPE.
16045 If the choice of partial specialization is ambiguous, a diagnostic
16046 is issued, and the error_mark_node is returned. If there are no
16047 partial specializations of TMPL matching TYPE, then NULL_TREE is
16048 returned. */
16050 static tree
16052 {
16054 tree t;
16055 tree champ;
16058 tree args;
16064 /* For determining which partial specialization to use, only the
16065 innermost args are interesting. */
16067 {
16070 }
16073 {
16074 tree partial_spec_args;
16075 tree spec_args;
16083 {
16086 /* Discard the outer levels of args, and then substitute in the
16087 template args from the enclosing class. */
16089 partial_spec_args = tsubst_template_args
16092 /* PARMS already refers to just the innermost parms, but the
16093 template parms in partial_spec_args had their levels lowered
16094 by tsubst, so we need to do the same for the parm list. We
16095 can't just tsubst the TREE_VEC itself, as tsubst wants to
16096 treat a TREE_VEC as an argument vector. */
16102 }
16104 partial_spec_args =
16107 partial_spec_args),
16118 partial_spec_args,
16119 args);
16121 {
16126 }
16127 }
16137 {
16140 ;
16141 else
16142 {
16144 {
16147 {
16150 }
16151 }
16153 }
16154 }
16158 {
16161 {
16164 }
16165 }
16168 {
16176 {
16179 }
16182 }
16185 }
16187 /* Explicitly instantiate DECL. */
16189 void
16191 {
16196 /* An error occurred, for which grokdeclarator has already issued
16197 an appropriate message. */
16200 {
16203 }
16205 {
16206 /* There is an asymmetry here in the way VAR_DECLs and
16207 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16208 the latter, the DECL we get back will be marked as a
16209 template instantiation, and the appropriate
16210 DECL_TEMPLATE_INFO will be set up. This does not happen for
16211 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16212 should handle VAR_DECLs as it currently handles
16213 FUNCTION_DECLs. */
16215 {
16218 }
16221 {
16224 }
16226 {
16231 }
16232 }
16234 {
16237 }
16238 else
16241 /* Check for various error cases. Note that if the explicit
16242 instantiation is valid the RESULT will currently be marked as an
16243 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16244 until we get here. */
16247 {
16248 /* DR 259 [temp.spec].
16250 Both an explicit instantiation and a declaration of an explicit
16251 specialization shall not appear in a program unless the explicit
16252 instantiation follows a declaration of the explicit specialization.
16254 For a given set of template parameters, if an explicit
16255 instantiation of a template appears after a declaration of an
16256 explicit specialization for that template, the explicit
16257 instantiation has no effect. */
16259 }
16261 {
16262 /* [temp.spec]
16264 No program shall explicitly instantiate any template more
16265 than once.
16267 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16268 the first instantiation was `extern' and the second is not,
16269 and EXTERN_P for the opposite case. */
16272 /* If an "extern" explicit instantiation follows an ordinary
16273 explicit instantiation, the template is instantiated. */
16276 }
16278 {
16281 }
16283 {
16286 }
16289 ;
16291 {
16294 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16297 }
16298 else
16306 }
16308 static void
16310 {
16316 {
16319 }
16320 }
16322 /* Called from do_type_instantiation through binding_table_foreach to
16323 do recursive instantiation for the type bound in ENTRY. */
16324 static void
16326 {
16332 }
16334 /* Called from do_type_instantiation to instantiate a member
16335 (a member function or a static member variable) of an
16336 explicitly instantiated class template. */
16337 static void
16339 {
16344 }
16346 /* Perform an explicit instantiation of template class T. STORAGE, if
16347 non-null, is the RID for extern, inline or static. COMPLAIN is
16348 nonzero if this is called from the parser, zero if called recursively,
16349 since the standard is unclear (as detailed below). */
16351 void
16353 {
16363 {
16366 }
16371 {
16374 t);
16376 }
16379 {
16381 {
16383 {
16386 "ISO C++ 1998 forbids the use of %<extern%> on "
16388 }
16389 else
16391 "ISO C++ forbids the use of %qE"
16393 }
16401 else
16402 {
16404 storage);
16406 }
16407 }
16410 {
16411 /* DR 259 [temp.spec].
16413 Both an explicit instantiation and a declaration of an explicit
16414 specialization shall not appear in a program unless the explicit
16415 instantiation follows a declaration of the explicit specialization.
16417 For a given set of template parameters, if an explicit
16418 instantiation of a template appears after a declaration of an
16419 explicit specialization for that template, the explicit
16420 instantiation has no effect. */
16422 }
16424 {
16425 /* [temp.spec]
16427 No program shall explicitly instantiate any template more
16428 than once.
16430 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16431 instantiation was `extern'. If EXTERN_P then the second is.
16432 These cases are OK. */
16439 /* If we've already instantiated the template, just return now. */
16442 }
16450 {
16451 tree tmp;
16453 /* In contrast to implicit instantiation, where only the
16454 declarations, and not the definitions, of members are
16455 instantiated, we have here:
16457 [temp.explicit]
16459 The explicit instantiation of a class template specialization
16460 implies the instantiation of all of its members not
16461 previously explicitly specialized in the translation unit
16462 containing the explicit instantiation.
16464 Of course, we can't instantiate member template classes, since
16465 we don't have any arguments for them. Note that the standard
16466 is unclear on whether the instantiation of the members are
16467 *explicit* instantiations or not. However, the most natural
16468 interpretation is that it should be an explicit instantiation. */
16483 }
16484 }
16486 /* Given a function DECL, which is a specialization of TMPL, modify
16487 DECL to be a re-instantiation of TMPL with the same template
16488 arguments. TMPL should be the template into which tsubst'ing
16489 should occur for DECL, not the most general template.
16491 One reason for doing this is a scenario like this:
16493 template <class T>
16494 void f(const T&, int i);
16496 void g() { f(3, 7); }
16498 template <class T>
16499 void f(const T& t, const int i) { }
16501 Note that when the template is first instantiated, with
16502 instantiate_template, the resulting DECL will have no name for the
16503 first parameter, and the wrong type for the second. So, when we go
16504 to instantiate the DECL, we regenerate it. */
16506 static void
16508 {
16509 /* The arguments used to instantiate DECL, from the most general
16510 template. */
16511 tree args;
16512 tree code_pattern;
16517 /* Make sure that we can see identifiers, and compute access
16518 correctly. */
16522 {
16523 tree decl_parm;
16524 tree pattern_parm;
16525 tree specs;
16538 specs);
16540 /* Merge parameter declarations. */
16543 pattern_parm
16547 {
16548 tree parm_type;
16549 tree attributes;
16554 NULL_TREE);
16560 {
16563 }
16566 }
16567 /* Merge any parameters that match with the function parameter
16568 pack. */
16570 {
16572 tree expanded_types;
16573 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16574 the parameters in this function parameter pack. */
16579 {
16580 tree parm_type;
16581 tree attributes;
16584 /* Rename the parameter to include the index. */
16593 {
16596 }
16598 }
16599 }
16600 /* Merge additional specifiers from the CODE_PATTERN. */
16604 }
16606 {
16614 }
16615 else
16619 }
16621 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16622 substituted to get DECL. */
16624 tree
16626 {
16629 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16630 for the instantiation. This is not always the most general
16631 template. Consider, for example:
16633 template <class T>
16634 struct S { template <class U> void f();
16635 template <> void f<int>(); };
16637 and an instantiation of S<double>::f<int>. We want TD to be the
16638 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16640 more general template. */
16642 /* We must also deal with friend templates. Given:
16644 template <class T> struct S {
16645 template <class U> friend void f() {};
16646 };
16648 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16649 so far as the language is concerned, but that's still
16650 where we get the pattern for the instantiation from. On
16651 other hand, if the definition comes outside the class, say:
16653 template <class T> struct S {
16654 template <class U> friend void f();
16655 };
16656 template <class U> friend void f() {}
16658 we don't need to look any further. That's what the check for
16659 DECL_INITIAL is for. */
16663 {
16664 /* The present template, TD, should not be a definition. If it
16665 were a definition, we should be using it! Note that we
16666 cannot restructure the loop to just keep going until we find
16667 a template with a definition, since that might go too far if
16668 a specialization was declared, but not defined. */
16672 /* Fetch the more general template. */
16674 }
16677 }
16679 /* Returns true if we need to instantiate this template instance even if we
16680 know we aren't going to emit it.. */
16682 bool
16684 {
16685 /* We always instantiate inline functions so that we can inline them. An
16686 explicit instantiation declaration prohibits implicit instantiation of
16687 non-inline functions. With high levels of optimization, we would
16688 normally inline non-inline functions -- but we're not allowed to do
16689 that for "extern template" functions. Therefore, we check
16690 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16693 /* And we need to instantiate static data members so that
16694 their initializers are available in integral constant
16695 expressions. */
16698 }
16700 /* Produce the definition of D, a _DECL generated from a template. If
16701 DEFER_OK is nonzero, then we don't have to actually do the
16702 instantiation now; we just have to do it sometime. Normally it is
16703 an error if this is an explicit instantiation but D is undefined.
16704 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16705 explicitly instantiated class template. */
16707 tree
16710 {
16712 tree gen_args;
16713 tree args;
16714 tree td;
16715 tree code_pattern;
16716 tree spec;
16717 tree gen_tmpl;
16723 /* This function should only be used to instantiate templates for
16724 functions and static member variables. */
16728 /* Variables are never deferred; if instantiation is required, they
16729 are instantiated right away. That allows for better code in the
16730 case that an expression refers to the value of the variable --
16731 if the variable has a constant value the referring expression can
16732 take advantage of that fact. */
16736 /* Don't instantiate cloned functions. Instead, instantiate the
16737 functions they cloned. */
16743 /* D has already been instantiated or explicitly specialized, so
16744 there's nothing for us to do here.
16746 It might seem reasonable to check whether or not D is an explicit
16747 instantiation, and, if so, stop here. But when an explicit
16748 instantiation is deferred until the end of the compilation,
16749 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16750 the instantiation. */
16753 /* Check to see whether we know that this template will be
16754 instantiated in some other file, as with "extern template"
16755 extension. */
16758 /* In general, we do not instantiate such templates. */
16766 /* We should already have the extra args. */
16769 /* And what's in the hash table should match D. */
16773 /* This needs to happen before any tsubsting. */
16779 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16780 for the instantiation. */
16784 /* We should never be trying to instantiate a member of a class
16785 template or partial specialization. */
16790 /* In the case of a friend template whose definition is provided
16791 outside the class, we may have too many arguments. Drop the
16792 ones we don't need. The same is true for specializations. */
16793 args = get_innermost_template_args
16795 else
16800 else
16803 /* We may be in the middle of deferred access check. Disable it now. */
16806 /* Unless an explicit instantiation directive has already determined
16807 the linkage of D, remember that a definition is available for
16808 this entity. */
16816 /* If D is a member of an explicitly instantiated class template,
16817 and no definition is available, treat it like an implicit
16818 instantiation. */
16821 {
16825 }
16827 /* Recheck the substitutions to obtain any warning messages
16828 about ignoring cv qualifiers. Don't do this for artificial decls,
16829 as it breaks the context-sensitive substitution for lambda op(). */
16831 {
16835 /* Make sure that we can see identifiers, and compute access
16836 correctly. D is already the target FUNCTION_DECL with the
16837 right context. */
16841 {
16844 d);
16845 /* Don't simply tsubst the function type, as that will give
16846 duplicate warnings about poor parameter qualifications.
16847 The function arguments are the same as the decl_arguments
16848 without the top level cv qualifiers. */
16850 }
16854 }
16856 /* Defer all other templates, unless we have been explicitly
16857 forbidden from doing so. */
16859 template. */
16860 ! pattern_defined
16861 /* If it's OK to postpone instantiation, do so. */
16862 || defer_ok
16863 /* If this is a static data member that will be defined
16864 elsewhere, we don't want to instantiate the entire data
16865 member, but we do want to instantiate the initializer so that
16866 we can substitute that elsewhere. */
16868 {
16869 /* The definition of the static data member is now required so
16870 we must substitute the initializer. */
16874 {
16875 tree ns;
16876 tree init;
16882 args,
16887 LOOKUP_ONLYCONVERTING);
16890 }
16892 /* We restore the source position here because it's used by
16893 add_pending_template. */
16899 /* [temp.explicit]
16901 The definition of a non-exported function template, a
16902 non-exported member function template, or a non-exported
16903 member function or static data member of a class template
16904 shall be present in every translation unit in which it is
16905 explicitly instantiated. */
16909 /* ??? Historically, we have instantiated inline functions, even
16910 when marked as "extern template". */
16914 }
16915 /* Tell the repository that D is available in this translation unit
16916 -- and see if it is supposed to be instantiated here. */
16918 {
16919 /* In a PCH file, despite the fact that the repository hasn't
16920 requested instantiation in the PCH it is still possible that
16921 an instantiation will be required in a file that includes the
16922 PCH. */
16925 /* Instantiate inline functions so that the inliner can do its
16926 job, even though we'll not be emitting a copy of this
16927 function. */
16930 }
16936 /* Mark D as instantiated so that recursive calls to
16937 instantiate_decl do not try to instantiate it again. */
16940 /* Regenerate the declaration in case the template has been modified
16941 by a subsequent redeclaration. */
16944 /* We already set the file and line above. Reset them now in case
16945 they changed as a result of calling regenerate_decl_from_template. */
16949 {
16950 tree init;
16952 /* Clear out DECL_RTL; whatever was there before may not be right
16953 since we've reset the type of the declaration. */
16957 /* The initializer is placed in DECL_INITIAL by
16958 regenerate_decl_from_template. Pull it out so that
16959 cp_finish_decl can process it. */
16964 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16965 initializer. That function will defer actual emission until
16966 we have a chance to determine linkage. */
16969 /* Enter the scope of D so that access-checking works correctly. */
16973 }
16975 {
16976 htab_t saved_local_specializations;
16977 tree subst_decl;
16978 tree tmpl_parm;
16979 tree spec_parm;
16981 /* Save away the current list, in case we are instantiating one
16982 template from within the body of another. */
16985 /* Set up the list of local specializations. */
16987 hash_local_specialization,
16988 eq_local_specializations,
16989 NULL);
16991 /* Set up context. */
16994 /* Create substitution entries for the parameters. */
16999 {
17003 }
17005 {
17009 }
17011 {
17012 /* Register the (value) argument pack as a specialization of
17013 TMPL_PARM, then move on. */
17018 }
17021 /* Substitute into the body of the function. */
17026 /* Set the current input_location to the end of the function
17027 so that finish_function knows where we are. */
17030 /* We don't need the local specializations any more. */
17034 /* Finish the function. */
17037 }
17039 /* We're not deferring instantiation any more. */
17045 out:
17053 }
17055 /* Run through the list of templates that we wish we could
17056 instantiate, and instantiate any we can. RETRIES is the
17057 number of times we retry pending template instantiation. */
17059 void
17061 {
17065 /* Instantiating templates may trigger vtable generation. This in turn
17066 may require further template instantiations. We place a limit here
17067 to avoid infinite loop. */
17069 {
17073 " instantiating %q+D, possibly from virtual table generation"
17077 /* Pretend that we defined it. */
17080 }
17082 do
17083 {
17088 {
17093 {
17094 tree fn;
17097 {
17101 fn;
17109 }
17112 }
17113 else
17114 {
17117 {
17118 instantiation
17124 }
17128 }
17131 /* If INSTANTIATION has been instantiated, then we don't
17132 need to consider it again in the future. */
17134 else
17135 {
17138 }
17141 }
17143 }
17147 }
17149 /* Substitute ARGVEC into T, which is a list of initializers for
17150 either base class or a non-static data member. The TREE_PURPOSEs
17151 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17152 instantiate_decl. */
17154 static tree
17156 {
17160 {
17161 tree decl;
17162 tree init;
17168 {
17169 tree expr;
17170 tree arg;
17172 /* Expand the base class expansion type into separate base
17173 classes. */
17175 tf_warning_or_error,
17176 NULL_TREE);
17180 /* We'll be building separate TREE_LISTs of arguments for
17181 each base. */
17187 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17188 expand each argument in the TREE_VALUE of t. */
17194 /* VOID_TYPE_NODE is used to indicate
17195 value-initialization. */
17196 {
17199 }
17200 else
17201 {
17202 /* Substitute parameter packs into each argument in the
17203 TREE_LIST. */
17206 {
17207 tree expanded_exprs;
17209 /* Expand the argument. */
17211 expanded_exprs
17213 tf_warning_or_error,
17214 NULL_TREE);
17218 /* Prepend each of the expanded expressions to the
17219 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17221 {
17226 }
17227 }
17230 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17231 since we built them backwards. */
17233 {
17236 }
17237 }
17238 }
17241 {
17243 {
17247 }
17248 else
17249 {
17261 }
17264 {
17268 }
17269 }
17270 }
17272 }
17274 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17276 static void
17278 {
17283 else
17285 }
17287 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17288 is the instantiation (which should have been created with
17289 start_enum) and ARGS are the template arguments to use. */
17291 static void
17293 {
17294 tree e;
17297 {
17298 tree value;
17299 tree decl;
17302 /* Note that in a template enum, the TREE_VALUE is the
17303 CONST_DECL, not the corresponding INTEGER_CST. */
17308 /* Give this enumeration constant the correct access. */
17311 /* Actually build the enumerator itself. */
17312 build_enumerator
17314 }
17319 }
17321 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17322 its type -- but without substituting the innermost set of template
17323 arguments. So, innermost set of template parameters will appear in
17324 the type. */
17326 tree
17328 {
17329 tree fn_type;
17330 tree tmpl;
17331 tree targs;
17332 tree tparms;
17340 /* There should be as many levels of arguments as there are levels
17341 of parameters. */
17347 /* No substitution is necessary. */
17348 ;
17349 else
17350 {
17352 tree partial_args;
17354 /* Replace the innermost level of the TARGS with NULL_TREEs to
17355 let tsubst know not to substitute for those parameters. */
17364 /* Disable access control as this function is used only during
17365 name-mangling. */
17370 /* Now, do the (partial) substitution to figure out the
17371 appropriate function type. */
17375 /* Substitute into the template parameters to obtain the real
17376 innermost set of parameters. This step is important if the
17377 innermost set of template parameters contains value
17378 parameters whose types depend on outer template parameters. */
17383 }
17386 }
17388 /* Return truthvalue if we're processing a template different from
17389 the last one involved in diagnostics. */
17390 int
17392 {
17394 }
17396 /* Remember current template involved in diagnostics. */
17397 void
17399 {
17401 }
17405 {
17407 }
17409 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17410 type. Return zero for ok, nonzero for disallowed. Issue error and
17411 warning messages under control of COMPLAIN. */
17413 static int
17415 {
17430 }
17432 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17433 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17435 static bool
17437 {
17438 tree scope;
17440 /* [temp.dep.type]
17442 A type is dependent if it is:
17444 -- a template parameter. Template template parameters are types
17445 for us (since TYPE_P holds true for them) so we handle
17446 them here. */
17450 /* -- a qualified-id with a nested-name-specifier which contains a
17451 class-name that names a dependent type or whose unqualified-id
17452 names a dependent type. */
17455 /* -- a cv-qualified type where the cv-unqualified type is
17456 dependent. */
17458 /* -- a compound type constructed from any dependent type. */
17468 {
17469 tree arg_type;
17474 arg_type;
17479 }
17480 /* -- an array type constructed from any dependent type or whose
17481 size is specified by a constant expression that is
17482 value-dependent. */
17484 {
17489 }
17492 {
17493 /* If this is the TYPE_DOMAIN of an array type, consider it
17494 dependent. We already checked for value-dependence in
17495 compute_array_index_type. */
17497 }
17499 /* -- a template-id in which either the template name is a template
17500 parameter ... */
17503 /* ... or any of the template arguments is a dependent type or
17504 an expression that is type-dependent or value-dependent. */
17506 && (any_dependent_template_arguments_p
17510 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17511 argument of the `typeof' expression is not type-dependent, then
17512 it should already been have resolved. */
17517 /* A template argument pack is dependent if any of its packed
17518 arguments are. */
17520 {
17526 }
17528 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17529 be template parameters. */
17533 /* The standard does not specifically mention types that are local
17534 to template functions or local classes, but they should be
17535 considered dependent too. For example:
17537 template <int I> void f() {
17538 enum E { a = I };
17539 S<sizeof (E)> s;
17540 }
17542 The size of `E' cannot be known until the value of `I' has been
17543 determined. Therefore, `E' must be considered dependent. */
17550 /* Other types are non-dependent. */
17552 }
17554 /* Returns TRUE if TYPE is dependent, in the sense of
17555 [temp.dep.type]. */
17557 bool
17559 {
17560 /* If there are no template parameters in scope, then there can't be
17561 any dependent types. */
17563 {
17564 /* If we are not processing a template, then nobody should be
17565 providing us with a dependent type. */
17569 }
17571 /* If the type is NULL, we have not computed a type for the entity
17572 in question; in that case, the type is dependent. */
17576 /* Erroneous types can be considered non-dependent. */
17580 /* If we have not already computed the appropriate value for TYPE,
17581 do so now. */
17583 {
17586 }
17589 }
17591 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17592 lookup. In other words, a dependent type that is not the current
17593 instantiation. */
17595 bool
17597 {
17600 }
17602 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17603 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17604 expression. */
17606 bool
17608 {
17612 /* A name declared with a dependent type. */
17617 {
17619 /* A name that has not been looked up -- must be dependent. */
17623 /* A non-type template parm. */
17627 /* A non-type template parm. */
17633 /* A constant with integral or enumeration type and is initialized
17634 with an expression that is value-dependent. */
17646 /* These expressions are value-dependent if the type to which
17647 the cast occurs is dependent or the expression being casted
17648 is value-dependent. */
17649 {
17655 /* A functional cast has a list of operands. */
17658 {
17659 /* If there are no operands, it must be an expression such
17660 as "int()". This should not happen for aggregate types
17661 because it would form non-constant expressions. */
17665 }
17671 }
17675 /* A `sizeof' expression is value-dependent if the operand is
17676 type-dependent or is a pack expansion. */
17686 /* FIXME why check value-dependency? */
17691 {
17694 }
17701 /* A CALL_EXPR may appear in a constant expression if it is a
17702 call to a builtin function, e.g., __builtin_constant_p. All
17703 such calls are value-dependent. */
17707 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17708 is value-dependent. */
17709 {
17718 }
17721 {
17725 }
17732 {
17736 }
17739 /* A constant expression is value-dependent if any subexpression is
17740 value-dependent. */
17742 {
17752 || (value_dependent_expression_p
17757 {
17760 /* In some cases, some of the operands may be missing.
17761 (For example, in the case of PREDECREMENT_EXPR, the
17762 amount to increment by may be missing.) That doesn't
17763 make the expression dependent. */
17765 && (value_dependent_expression_p
17769 }
17773 }
17774 }
17776 /* The expression is not value-dependent. */
17778 }
17780 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17781 [temp.dep.expr]. */
17783 bool
17785 {
17792 /* An unresolved name is always dependent. */
17797 /* Some expression forms are never type-dependent. */
17809 /* The types of these expressions depends only on the type to which
17810 the cast occurs. */
17818 /* The types of these expressions depends only on the type created
17819 by the expression. */
17822 {
17823 /* For NEW_EXPR tree nodes created inside a template, either
17824 the object type itself or a TREE_LIST may appear as the
17825 operand 1. */
17828 /* This is an array type. We need to check array dimensions
17829 as well. */
17831 || value_dependent_expression_p
17833 else
17835 }
17838 {
17842 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
17843 contains an identifier associated by name lookup with one or more
17844 declarations declared with a dependent type, or...a
17845 nested-name-specifier or qualified-id that names a member of an
17846 unknown specialization. */
17849 }
17854 && (any_dependent_template_arguments_p
17866 {
17867 tree elt;
17871 {
17874 }
17876 }
17878 /* A static data member of the current instantiation with incomplete
17879 array type is type-dependent, as the definition and specializations
17880 can have different bounds. */
17888 {
17893 {
17899 }
17900 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17908 {
17913 }
17918 {
17922 }
17924 }
17929 }
17931 /* Like type_dependent_expression_p, but it also works while not processing
17932 a template definition, i.e. during substitution or mangling. */
17934 bool
17936 {
17942 }
17944 /* Returns TRUE if ARGS contains a type-dependent expression. */
17946 bool
17948 {
17950 tree arg;
17953 {
17956 }
17958 }
17960 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17961 expressions) contains any value-dependent expressions. */
17963 bool
17965 {
17971 }
17973 /* Returns TRUE if the ARG (a template argument) is dependent. */
17975 bool
17977 {
17985 {
17989 {
17992 }
17995 }
17998 else
18001 }
18003 /* Returns true if ARGS (a collection of template arguments) contains
18004 any types that require structural equality testing. */
18006 bool
18008 {
18018 {
18021 {
18027 {
18028 /* Look inside the argument pack. */
18031 }
18034 {
18048 }
18049 }
18050 }
18053 }
18055 /* Returns true if ARGS (a collection of template arguments) contains
18056 any dependent arguments. */
18058 bool
18060 {
18070 {
18075 }
18078 }
18080 /* Returns TRUE if the template TMPL is dependent. */
18082 bool
18084 {
18086 {
18088 {
18092 }
18094 }
18096 /* Template template parameters are dependent. */
18100 /* So are names that have not been looked up. */
18104 /* So are member templates of dependent classes. */
18108 }
18110 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18112 bool
18114 {
18117 }
18119 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18120 is dependent. */
18122 bool
18124 {
18131 {
18152 {
18156 }
18160 {
18164 {
18169 }
18170 }
18171 }
18174 }
18176 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18177 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18178 no such TYPE can be found. Note that this function peers inside
18179 uninstantiated templates and therefore should be used only in
18180 extremely limited situations. ONLY_CURRENT_P restricts this
18181 peering to the currently open classes hierarchy (which is required
18182 when comparing types). */
18184 tree
18186 {
18187 tree scope;
18188 tree name;
18189 tree decl;
18191 tree pushed_scope;
18192 tree result;
18197 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18198 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18199 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18200 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18201 identifier of the TYPENAME_TYPE anymore.
18202 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18203 TYPENAME_TYPE instead, we avoid messing up with a possible
18204 typedef variant case. */
18207 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18208 it first before we can figure out what NAME refers to. */
18211 /* If we don't know what SCOPE refers to, then we cannot resolve the
18212 TYPENAME_TYPE. */
18215 /* If the SCOPE is a template type parameter, we have no way of
18216 resolving the name. */
18219 /* If the SCOPE is not the current instantiation, there's no reason
18220 to look inside it. */
18223 /* If this is a typedef, we don't want to look inside (c++/11987). */
18226 /* If SCOPE isn't the template itself, it will not have a valid
18227 TYPE_FIELDS list. */
18229 /* scope is either the template itself or a compatible instantiation
18230 like X<T>, so look up the name in the original template. */
18232 else
18233 /* scope is a partial instantiation, so we can't do the lookup or we
18234 will lose the template arguments. */
18236 /* Enter the SCOPE so that name lookup will be resolved as if we
18237 were in the class definition. In particular, SCOPE will no
18238 longer be considered a dependent type. */
18240 /* Look up the declaration. */
18245 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18246 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18251 {
18255 }
18258 {
18259 tree tmpl;
18260 tree args;
18261 /* Obtain the template and the arguments. */
18264 /* Instantiate the template. */
18270 }
18272 /* Leave the SCOPE. */
18276 /* If we failed to resolve it, return the original typename. */
18280 /* If lookup found a typename type, resolve that too. */
18282 {
18283 /* Ill-formed programs can cause infinite recursion here, so we
18284 must catch that. */
18288 }
18290 /* Qualify the resulting type. */
18296 }
18298 /* EXPR is an expression which is not type-dependent. Return a proxy
18299 for EXPR that can be used to compute the types of larger
18300 expressions containing EXPR. */
18302 tree
18304 {
18305 tree inner_expr;
18307 /* Preserve null pointer constants so that the type of things like
18308 "p == 0" where "p" is a pointer can be determined. */
18311 /* Preserve OVERLOADs; the functions must be available to resolve
18312 types. */
18323 /* There is no need to return a proxy for a variable. */
18326 /* Preserve string constants; conversions from string constants to
18327 "char *" are allowed, even though normally a "const char *"
18328 cannot be used to initialize a "char *". */
18331 /* Preserve arithmetic constants, as an optimization -- there is no
18332 reason to create a new node. */
18335 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18336 There is at least one place where we want to know that a
18337 particular expression is a throw-expression: when checking a ?:
18338 expression, there are special rules if the second or third
18339 argument is a throw-expression. */
18358 /* If the type is unknown, it can't really be non-dependent */
18361 /* Otherwise, build a NON_DEPENDENT_EXPR.
18363 REFERENCE_TYPEs are not stripped for expressions in templates
18364 because doing so would play havoc with mangling. Consider, for
18365 example:
18367 template <typename T> void f<T& g>() { g(); }
18369 In the body of "f", the expression for "g" will have
18370 REFERENCE_TYPE, even though the standard says that it should
18371 not. The reason is that we must preserve the syntactic form of
18372 the expression so that mangling (say) "f<g>" inside the body of
18373 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18374 stripped here. */
18376 }
18378 /* ARGS is a vector of expressions as arguments to a function call.
18379 Replace the arguments with equivalent non-dependent expressions.
18380 This modifies ARGS in place. */
18382 void
18384 {
18386 tree arg;
18389 {
18393 }
18394 }
18396 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18397 with a level one deeper than the actual template parms. */
18399 tree
18401 {
18414 }
18416 /* Given type ARG, return std::initializer_list<ARG>. */
18418 static tree
18420 {
18421 tree std_init_list = namespace_binding
18423 tree argvec;
18425 {
18429 }
18434 }
18436 /* Replace auto in TYPE with std::initializer_list<auto>. */
18438 static tree
18440 {
18447 }
18449 /* walk_tree helper for do_auto_deduction. */
18451 static tree
18454 {
18455 /* Is this a variable with the type we're looking for? */
18459 else
18461 }
18463 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18464 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18466 tree
18468 {
18471 tree decl;
18474 /* The name of the object being declared shall not appear in the
18475 initializer expression. */
18478 {
18482 }
18484 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18485 with either a new invented type template parameter U or, if the
18486 initializer is a braced-init-list (8.5.4), with
18487 std::initializer_list<U>. */
18500 {
18503 }
18505 /* If the list of declarators contains more than one declarator, the type
18506 of each declared variable is determined as described above. If the
18507 type deduced for the template parameter U is not the same in each
18508 deduction, the program is ill-formed. */
18511 {
18515 }
18521 }
18523 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18524 result. */
18526 tree
18528 {
18529 tree argvec;
18538 }
18540 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18542 bool
18544 {
18548 else
18550 }
18552 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18553 appear as a type-specifier for the declaration in question, we don't
18554 have to look through the whole type. */
18556 tree
18558 {
18575 }
18577 /* For a given template T, return the vector of typedefs referenced
18578 in T for which access check is needed at T instantiation time.
18579 T is either a FUNCTION_DECL or a RECORD_TYPE.
18580 Those typedefs were added to T by the function
18581 append_type_to_template_for_access_check. */
18585 {
18586 tree ti;
18597 {
18602 }
18605 }
18607 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18608 tied to T. That list of typedefs will be access checked at
18609 T instantiation time.
18610 T is either a FUNCTION_DECL or a RECORD_TYPE.
18611 TYPE_DECL is a TYPE_DECL node representing a typedef.
18612 SCOPE is the scope through which TYPE_DECL is accessed.
18613 LOCATION is the location of the usage point of TYPE_DECL.
18615 This function is a subroutine of
18616 append_type_to_template_for_access_check. */
18618 static void
18620 tree type_decl,
18621 tree scope,
18622 location_t location)
18623 {
18624 qualified_typedef_usage_t typedef_usage;
18625 tree ti;
18632 && type_decl
18648 }
18650 /* Append TYPE_DECL to the template TEMPL.
18651 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18652 At TEMPL instanciation time, TYPE_DECL will be checked to see
18653 if it can be accessed through SCOPE.
18654 LOCATION is the location of the usage point of TYPE_DECL.
18656 e.g. consider the following code snippet:
18658 class C
18659 {
18660 typedef int myint;
18661 };
18663 template<class U> struct S
18664 {
18665 C::myint mi; // <-- usage point of the typedef C::myint
18666 };
18668 S<char> s;
18670 At S<char> instantiation time, we need to check the access of C::myint
18671 In other words, we need to check the access of the myint typedef through
18672 the C scope. For that purpose, this function will add the myint typedef
18673 and the scope C through which its being accessed to a list of typedefs
18674 tied to the template S. That list will be walked at template instantiation
18675 time and access check performed on each typedefs it contains.
18676 Note that this particular code snippet should yield an error because
18677 myint is private to C. */
18679 void
18681 tree type_decl,
18682 tree scope,
18683 location_t location)
18684 {
18690 /* Make sure we don't append the type to the template twice. */
18699 }
18701 /* Set up the hash tables for template instantiations. */
18703 void
18705 {
18707 hash_specialization,
18708 eq_specializations,
18709 ggc_free);
18711 hash_specialization,
18712 eq_specializations,
18713 ggc_free);
18714 }
18716 /* Print stats about the template hash tables for -fstats. */
18718 void
18720 {
18729 }