| blob | 6f6235c009de8b1674eca9442f2aabbedb24560d |
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, 2011, 2012
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. */
83 /* True if we've recursed into fn_type_unification too many times. */
87 {
88 tree tmpl;
89 tree args;
90 tree spec;
94 htab_t decl_specializations;
97 htab_t type_specializations;
99 /* Contains canonical template parameter types. The vector is indexed by
100 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
101 TREE_LIST, whose TREE_VALUEs contain the canonical template
102 parameters of various types and levels. */
105 #define UNIFY_ALLOW_NONE 0
106 #define UNIFY_ALLOW_MORE_CV_QUAL 1
107 #define UNIFY_ALLOW_LESS_CV_QUAL 2
108 #define UNIFY_ALLOW_DERIVED 4
109 #define UNIFY_ALLOW_INTEGER 8
110 #define UNIFY_ALLOW_OUTER_LEVEL 16
111 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
112 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
115 tbr_incomplete_type,
116 tbr_ambiguous_baseclass,
117 tbr_success
118 };
139 tree);
201 location_t);
209 /* Make the current scope suitable for access checking when we are
210 processing T. T can be FUNCTION_DECL for instantiated function
211 template, or VAR_DECL for static member variable (need by
212 instantiate_decl). */
214 static void
216 {
224 else
228 {
229 saved_access_scope = tree_cons
232 }
233 }
235 /* Restore the scope set up by push_access_scope. T is the node we
236 are processing. */
238 static void
240 {
242 {
245 }
249 else
251 }
253 /* Do any processing required when DECL (a member template
254 declaration) is finished. Returns the TEMPLATE_DECL corresponding
255 to DECL, unless it is a specialization, in which case the DECL
256 itself is returned. */
258 tree
260 {
267 {
268 tree type;
276 {
280 }
282 }
286 {
288 {
291 }
292 else
294 }
295 else
299 }
301 /* Create a template info node. */
303 tree
305 {
310 }
312 /* Return the template info node corresponding to T, whatever T is. */
314 tree
316 {
334 }
336 /* Returns the template nesting level of the indicated class TYPE.
338 For example, in:
339 template <class T>
340 struct A
341 {
342 template <class U>
343 struct B {};
344 };
346 A<T>::B<U> has depth two, while A<T> has depth one.
347 Both A<T>::B<int> and A<int>::B<U> have depth one, if
348 they are instantiations, not specializations.
350 This function is guaranteed to return 0 if passed NULL_TREE so
351 that, for example, `template_class_depth (current_class_type)' is
352 always safe. */
354 int
356 {
363 {
369 }
372 }
374 /* Subroutine of maybe_begin_member_template_processing.
375 Returns true if processing DECL needs us to push template parms. */
377 static bool
379 {
385 }
387 /* Subroutine of maybe_begin_member_template_processing.
388 Push the template parms in PARMS, starting from LEVELS steps into the
389 chain, and ending at the beginning, since template parms are listed
390 innermost first. */
392 static void
394 {
402 current_template_parms
408 NULL);
410 {
419 {
426 {
427 /* Make a CONST_DECL as is done in process_template_parm.
428 It is ugly that we recreate this here; the original
429 version built in process_template_parm is no longer
430 available. */
440 }
445 }
446 }
447 }
449 /* Restore the template parameter context for a member template or
450 a friend template defined in a class definition. */
452 void
454 {
455 tree parms;
459 {
464 {
467 }
470 }
472 /* Remember how many levels of template parameters we pushed so that
473 we can pop them later. */
475 }
477 /* Undo the effects of maybe_begin_member_template_processing. */
479 void
481 {
490 {
494 }
495 }
497 /* Return a new template argument vector which contains all of ARGS,
498 but has as its innermost set of arguments the EXTRA_ARGS. */
500 static tree
502 {
503 tree new_args;
521 }
523 /* Like add_to_template_args, but only the outermost ARGS are added to
524 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
525 (EXTRA_ARGS) levels are added. This function is used to combine
526 the template arguments from a partial instantiation with the
527 template arguments used to attain the full instantiation from the
528 partial instantiation. */
530 static tree
532 {
533 tree new_args;
535 /* If there are more levels of EXTRA_ARGS than there are ARGS,
536 something very fishy is going on. */
539 /* If *all* the new arguments will be the EXTRA_ARGS, just return
540 them. */
544 /* For the moment, we make ARGS look like it contains fewer levels. */
549 /* Now, we restore ARGS to its full dimensions. */
553 }
555 /* Return the N levels of innermost template arguments from the ARGS. */
557 tree
559 {
560 tree new_args;
566 /* If N is 1, just return the innermost set of template arguments. */
570 /* If we're not removing anything, just return the arguments we were
571 given. */
577 /* Make a new set of arguments, not containing the outer arguments. */
584 }
586 /* The inverse of get_innermost_template_args: Return all but the innermost
587 EXTRA_LEVELS levels of template arguments from the ARGS. */
589 static tree
591 {
592 tree new_args;
598 /* If N is 1, just return the outermost set of template arguments. */
602 /* If we're not removing anything, just return the arguments we were
603 given. */
608 /* Make a new set of arguments, not containing the inner arguments. */
615 }
617 /* We've got a template header coming up; push to a new level for storing
618 the parms. */
620 void
622 {
623 /* We use a non-tag-transparent scope here, which causes pushtag to
624 put tags in this scope, rather than in the enclosing class or
625 namespace scope. This is the right thing, since we want
626 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
627 global template class, push_template_decl handles putting the
628 TEMPLATE_DECL into top-level scope. For a nested template class,
629 e.g.:
631 template <class T> struct S1 {
632 template <class T> struct S2 {};
633 };
635 pushtag contains special code to call pushdecl_with_scope on the
636 TEMPLATE_DECL for S2. */
641 }
643 /* This routine is called when a specialization is declared. If it is
644 invalid to declare a specialization here, an error is reported and
645 false is returned, otherwise this routine will return true. */
647 static bool
649 {
652 /* [temp.expl.spec]
654 An explicit specialization shall be declared in the namespace of
655 which the template is a member, or, for member templates, in the
656 namespace of which the enclosing class or enclosing class
657 template is a member. An explicit specialization of a member
658 function, member class or static data member of a class template
659 shall be declared in the namespace of which the class template
660 is a member. */
662 {
665 }
667 /* [temp.expl.spec]
669 In an explicit specialization declaration for a member of a class
670 template or a member template that appears in namespace scope,
671 the member template and some of its enclosing class templates may
672 remain unspecialized, except that the declaration shall not
673 explicitly specialize a class member template if its enclosing
674 class templates are not explicitly specialized as well. */
676 {
679 }
682 }
684 /* We've just seen template <>. */
686 bool
688 {
692 }
694 /* Called at then end of processing a declaration preceded by
695 template<>. */
697 void
699 {
702 }
704 /* Any template <>'s that we have seen thus far are not referring to a
705 function specialization. */
707 void
709 {
712 }
714 /* We've just seen a template header. If SPECIALIZATION is nonzero,
715 it was of the form template <>. */
717 static void
719 {
721 template_header_count++;
722 }
724 /* We're beginning an explicit instantiation. */
726 void
728 {
731 }
734 void
736 {
739 }
741 /* An explicit specialization or partial specialization of TMPL is being
742 declared. Check that the namespace in which the specialization is
743 occurring is permissible. Returns false iff it is invalid to
744 specialize TMPL in the current namespace. */
746 static bool
748 {
751 /* [tmpl.expl.spec]
753 An explicit specialization shall be declared in the namespace of
754 which the template is a member, or, for member templates, in the
755 namespace of which the enclosing class or enclosing class
756 template is a member. An explicit specialization of a member
757 function, member class or static data member of a class template
758 shall be declared in the namespace of which the class template is
759 a member. */
762 {
765 }
767 /* Same or super-using namespace. */
769 else
770 {
774 }
775 }
777 /* SPEC is an explicit instantiation. Check that it is valid to
778 perform this explicit instantiation in the current namespace. */
780 static void
782 {
783 tree ns;
785 /* DR 275: An explicit instantiation shall appear in an enclosing
786 namespace of its template. */
792 }
794 /* The TYPE is being declared. If it is a template type, that means it
795 is a partial specialization. Do appropriate error-checking. */
797 tree
799 {
800 tree context;
806 {
810 }
815 /* Consider non-class instantiations of alias templates as
816 well. */
821 {
822 /* This is for ordinary explicit specialization and partial
823 specialization of a template class such as:
825 template <> class C<int>;
827 or:
829 template <class T> class C<T*>;
831 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 {
840 {
844 }
845 }
851 {
855 }
856 }
862 {
863 /* This is for an explicit specialization of member class
864 template according to [temp.expl.spec/18]:
866 template <> template <class U> class C<int>::D;
868 The context `C<int>' must be an implicit instantiation.
869 Otherwise this is just a member class template declared
870 earlier like:
872 template <> class C<int> { template <class U> class D; };
873 template <> template <class U> class C<int>::D;
875 In the first case, `C<int>::D' is a specialization of `C<T>::D'
876 while in the second case, `C<int>::D' is a primary template
877 and `C<T>::D' may not exist. */
881 {
882 tree t;
887 {
890 }
892 /* Check for invalid specialization after instantiation:
894 template <> template <> class C<int>::D<int>;
895 template <> template <class U> class C<int>::D; */
899 {
902 {
903 /* We already have a full specialization of this partial
904 instantiation. Reassign it to the new member
905 specialization template. */
906 spec_entry elt;
923 }
925 /* But if we've had an implicit instantiation, that's a
926 problem ([temp.expl.spec]/6). */
929 }
931 /* Mark TYPE as a specialization. And as a result, we only
932 have one level of template argument for the innermost
933 class template. */
937 }
938 }
940 {
941 /* Someday C++0x may allow for enum template specialization. */
946 else
947 {
950 }
951 }
954 }
956 /* Returns nonzero if we can optimize the retrieval of specializations
957 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
958 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
962 {
965 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
966 parameter. */
968 /* The optimized lookup depends on the fact that the
969 template arguments for the member function template apply
970 purely to the containing class, which is not true if the
971 containing class is an explicit or partial
972 specialization. */
976 /* It is possible to have a template that is not a member
977 template and is not a member of a template class:
979 template <typename T>
980 struct S { friend A::f(); };
982 Here, the friend function is a template, but the context does
983 not have template information. The optimized lookup relies
984 on having ARGS be the template arguments for both the class
985 and the function template. */
987 }
989 /* Retrieve the specialization (in the sense of [temp.spec] - a
990 specialization is either an instantiation or an explicit
991 specialization) of TMPL for the given template ARGS. If there is
992 no such specialization, return NULL_TREE. The ARGS are a vector of
993 arguments, or a vector of vectors of arguments, in the case of
994 templates with more than one level of parameters.
996 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
997 then we search for a partial specialization matching ARGS. This
998 parameter is ignored if TMPL is not a class template. */
1000 static tree
1002 {
1008 /* There should be as many levels of arguments as there are
1009 levels of parameters. */
1014 {
1015 tree class_template;
1016 tree class_specialization;
1018 tree fns;
1021 /* The template arguments actually apply to the containing
1022 class. Find the class specialization with those
1023 arguments. */
1025 class_specialization
1029 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1030 for the specialization. */
1034 /* Iterate through the methods with the indicated name, looking
1035 for the one that has an instance of TMPL. */
1038 {
1041 /* using-declarations can add base methods to the method vec,
1042 and we don't want those here. */
1045 }
1047 }
1048 else
1049 {
1051 spec_entry elt;
1052 htab_t specializations;
1060 else
1068 }
1071 }
1073 /* Like retrieve_specialization, but for local declarations. */
1075 static tree
1077 {
1085 }
1087 /* Returns nonzero iff DECL is a specialization of TMPL. */
1089 int
1091 {
1092 tree t;
1095 {
1101 }
1102 else
1103 {
1112 }
1115 }
1117 /* Returns nonzero iff DECL is a specialization of friend declaration
1118 FRIEND_DECL according to [temp.friend]. */
1120 bool
1122 {
1129 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1130 of a template class, we want to check if DECL is a specialization
1131 if this. */
1135 {
1136 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1139 }
1144 /* There is nothing to do if this is not a template friend. */
1151 /* [temp.friend/6]
1152 A member of a class template may be declared to be a friend of a
1153 non-template class. In this case, the corresponding member of
1154 every specialization of the class template is a friend of the
1155 class granting friendship.
1157 For example, given a template friend declaration
1159 template <class T> friend void A<T>::f();
1161 the member function below is considered a friend
1163 template <> struct A<int> {
1164 void f();
1165 };
1167 For this type of template friend, TEMPLATE_DEPTH below will be
1168 nonzero. To determine if DECL is a friend of FRIEND, we first
1169 check if the enclosing class is a specialization of another. */
1176 {
1177 /* Next, we check the members themselves. In order to handle
1178 a few tricky cases, such as when FRIEND_DECL's are
1180 template <class T> friend void A<T>::g(T t);
1181 template <class T> template <T t> friend void A<T>::h();
1183 and DECL's are
1185 void A<int>::g(int);
1186 template <int> void A<int>::h();
1188 we need to figure out ARGS, the template arguments from
1189 the context of DECL. This is required for template substitution
1190 of `T' in the function parameter of `g' and template parameter
1191 of `h' in the above examples. Here ARGS corresponds to `int'. */
1198 {
1200 {
1203 else
1205 current_depth++;
1206 }
1208 }
1211 {
1213 tree friend_type;
1214 tree decl_type;
1215 tree friend_args_type;
1216 tree decl_args_type;
1218 /* Make sure that both DECL and FRIEND_DECL are templates or
1219 non-templates. */
1225 {
1226 /* If both are templates, check template parameter list. */
1227 tree friend_parms
1232 friend_parms))
1236 }
1237 else
1245 /* Check if return types match. */
1249 /* Check if function parameter types match, ignoring the
1250 `this' parameter. */
1259 }
1260 else
1261 {
1262 /* DECL is a TYPE_DECL */
1266 /* Make sure that both DECL and FRIEND_DECL are templates or
1267 non-templates. */
1268 is_template
1275 {
1276 tree friend_parms;
1277 /* If both are templates, check the name of the two
1278 TEMPLATE_DECL's first because is_friend didn't. */
1283 /* Now check template parameter list. */
1284 friend_parms
1287 return comp_template_parms
1289 friend_parms);
1290 }
1291 else
1294 }
1295 }
1297 }
1299 /* Register the specialization SPEC as a specialization of TMPL with
1300 the indicated ARGS. IS_FRIEND indicates whether the specialization
1301 is actually just a friend declaration. Returns SPEC, or an
1302 equivalent prior declaration, if available. */
1304 static tree
1306 hashval_t hash)
1307 {
1308 tree fn;
1310 spec_entry elt;
1316 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1317 register it; we want the corresponding TEMPLATE_DECL instead.
1318 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1319 the more obvious `uses_template_parms (spec)' to avoid problems
1320 with default function arguments. In particular, given
1321 something like this:
1323 template <class T> void f(T t1, T t = T())
1325 the default argument expression is not substituted for in an
1326 instantiation unless and until it is actually needed. */
1330 /* We don't put these specializations in the hash table, but we might
1331 want to give an error about a mismatch. */
1333 else
1334 {
1342 slot =
1346 else
1348 }
1350 /* We can sometimes try to re-register a specialization that we've
1351 already got. In particular, regenerate_decl_from_template calls
1352 duplicate_decls which will update the specialization list. But,
1353 we'll still get called again here anyhow. It's more convenient
1354 to simply allow this than to try to prevent it. */
1358 {
1360 {
1363 {
1365 fn);
1367 }
1368 else
1369 {
1370 tree clone;
1371 /* This situation should occur only if the first
1372 specialization is an implicit instantiation, the
1373 second is an explicit specialization, and the
1374 implicit instantiation has not yet been used. That
1375 situation can occur if we have implicitly
1376 instantiated a member function and then specialized
1377 it later.
1379 We can also wind up here if a friend declaration that
1380 looked like an instantiation turns out to be a
1381 specialization:
1383 template <class T> void foo(T);
1384 class S { friend void foo<>(int) };
1385 template <> void foo(int);
1387 We transform the existing DECL in place so that any
1388 pointers to it become pointers to the updated
1389 declaration.
1391 If there was a definition for the template, but not
1392 for the specialization, we want this to look as if
1393 there were no definition, and vice versa. */
1396 /* The call to duplicate_decls will have applied
1397 [temp.expl.spec]:
1399 An explicit specialization of a function template
1400 is inline only if it is explicitly declared to be,
1401 and independently of whether its function template
1402 is.
1404 to the primary function; now copy the inline bits to
1405 the various clones. */
1407 {
1412 }
1416 }
1417 }
1419 {
1421 /* Dup decl failed, but this is a new definition. Set the
1422 line number so any errors match this new
1423 definition. */
1427 }
1428 }
1432 /* A specialization must be declared in the same namespace as the
1433 template it is specializing. */
1439 {
1447 /* TMPL is a forward declaration of a template function; keep a list
1448 of all specializations in case we need to reassign them to a friend
1449 template later in tsubst_friend_function. */
1452 }
1455 }
1457 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1458 TMPL and ARGS members, ignores SPEC. */
1460 static int
1462 {
1468 }
1470 /* Returns a hash for a template TMPL and template arguments ARGS. */
1472 static hashval_t
1474 {
1477 }
1479 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1480 ignoring SPEC. */
1482 static hashval_t
1484 {
1487 }
1489 /* Recursively calculate a hash value for a template argument ARG, for use
1490 in the hash tables of template specializations. */
1492 hashval_t
1494 {
1506 /* We can get one of these when re-hashing a previous entry in the middle
1507 of substituting into a pack expansion. Just look through it. */
1516 {
1524 {
1529 }
1551 {
1554 {
1557 }
1559 }
1563 {
1566 }
1577 val = iterative_hash_template_arg
1589 val);
1591 val);
1600 /* A lambda can't appear in a template arg, but don't crash on
1601 erroneous input. */
1613 /* Now hash operands as usual. */
1618 }
1621 {
1625 val);
1628 /* Otherwise just compare the types during lookup. */
1637 {
1642 }
1643 }
1646 }
1648 /* Unregister the specialization SPEC as a specialization of TMPL.
1649 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1650 if the SPEC was listed as a specialization of TMPL.
1652 Note that SPEC has been ggc_freed, so we can't look inside it. */
1654 bool
1656 {
1658 spec_entry elt;
1666 {
1671 }
1674 }
1676 /* Like register_specialization, but for local declarations. We are
1677 registering SPEC, an instantiation of TMPL. */
1679 static void
1681 {
1686 }
1688 /* TYPE is a class type. Returns true if TYPE is an explicitly
1689 specialized class. */
1691 bool
1693 {
1697 }
1699 /* Print the list of functions at FNS, going through all the overloads
1700 for each element of the list. Alternatively, FNS can not be a
1701 TREE_LIST, in which case it will be printed together with all the
1702 overloads.
1704 MORE and *STR should respectively be FALSE and NULL when the function
1705 is called from the outside. They are used internally on recursive
1706 calls. print_candidates manages the two parameters and leaves NULL
1707 in *STR when it ends. */
1709 static void
1711 {
1717 {
1721 }
1722 else
1723 {
1726 {
1727 /* Pick the prefix string. */
1729 {
1733 }
1737 }
1740 }
1743 {
1746 }
1747 }
1749 /* Print the list of candidate FNS in an error message. FNS can also
1750 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1752 void
1754 {
1758 }
1760 /* Returns the template (one of the functions given by TEMPLATE_ID)
1761 which can be specialized to match the indicated DECL with the
1762 explicit template args given in TEMPLATE_ID. The DECL may be
1763 NULL_TREE if none is available. In that case, the functions in
1764 TEMPLATE_ID are non-members.
1766 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1767 specialization of a member template.
1769 The TEMPLATE_COUNT is the number of references to qualifying
1770 template classes that appeared in the name of the function. See
1771 check_explicit_specialization for a more accurate description.
1773 TSK indicates what kind of template declaration (if any) is being
1774 declared. TSK_TEMPLATE indicates that the declaration given by
1775 DECL, though a FUNCTION_DECL, has template parameters, and is
1776 therefore a template function.
1778 The template args (those explicitly specified and those deduced)
1779 are output in a newly created vector *TARGS_OUT.
1781 If it is impossible to determine the result, an error message is
1782 issued. The error_mark_node is returned to indicate failure. */
1784 static tree
1786 tree decl,
1790 tmpl_spec_kind tsk)
1791 {
1792 tree fns;
1793 tree targs;
1794 tree explicit_targs;
1796 /* A TREE_LIST of templates of which DECL may be a specialization.
1797 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1798 corresponding TREE_PURPOSE is the set of template arguments that,
1799 when used to instantiate the template, would produce a function
1800 with the signature of DECL. */
1810 /* We shouldn't be specializing a member template of an
1811 unspecialized class template; we already gave an error in
1812 check_specialization_scope, now avoid crashing. */
1815 {
1818 }
1826 /* Check for baselinks. */
1831 {
1834 }
1836 /* Count the number of template headers specified for this
1837 specialization. */
1845 {
1849 {
1850 tree decl_arg_types;
1851 tree fn_arg_types;
1852 tree insttype;
1854 /* In case of explicit specialization, we need to check if
1855 the number of template headers appearing in the specialization
1856 is correct. This is usually done in check_explicit_specialization,
1857 but the check done there cannot be exhaustive when specializing
1858 member functions. Consider the following code:
1860 template <> void A<int>::f(int);
1861 template <> template <> void A<int>::f(int);
1863 Assuming that A<int> is not itself an explicit specialization
1864 already, the first line specializes "f" which is a non-template
1865 member function, whilst the second line specializes "f" which
1866 is a template member function. So both lines are syntactically
1867 correct, and check_explicit_specialization does not reject
1868 them.
1870 Here, we can do better, as we are matching the specialization
1871 against the declarations. We count the number of template
1872 headers, and we check if they match TEMPLATE_COUNT + 1
1873 (TEMPLATE_COUNT is the number of qualifying template classes,
1874 plus there must be another header for the member template
1875 itself).
1877 Notice that if header_count is zero, this is not a
1878 specialization but rather a template instantiation, so there
1879 is no check we can perform here. */
1883 /* Check that the number of template arguments at the
1884 innermost level for DECL is the same as for FN. */
1892 /* DECL might be a specialization of FN. */
1896 /* For a non-static member function, we need to make sure
1897 that the const qualification is the same. Since
1898 get_bindings does not try to merge the "this" parameter,
1899 we must do the comparison explicitly. */
1905 /* Skip the "this" parameter and, for constructors of
1906 classes with virtual bases, the VTT parameter. A
1907 full specialization of a constructor will have a VTT
1908 parameter, but a template never will. */
1909 decl_arg_types
1911 fn_arg_types
1914 /* Function templates cannot be specializations; there are
1915 no partial specializations of functions. Therefore, if
1916 the type of DECL does not match FN, there is no
1917 match. */
1919 {
1923 }
1925 /* See whether this function might be a specialization of this
1926 template. Suppress access control because we might be trying
1927 to make this specialization a friend, and we have already done
1928 access control for the declaration of the specialization. */
1934 /* We cannot deduce template arguments that when used to
1935 specialize TMPL will produce DECL. */
1938 /* Make sure that the deduced arguments actually work. */
1942 fn_arg_types
1947 /* Save this template, and the arguments deduced. */
1949 }
1951 /* FN is an ordinary member function, and we need a
1952 specialization of a member template. */
1953 ;
1955 /* We can get IDENTIFIER_NODEs here in certain erroneous
1956 cases. */
1957 ;
1959 /* This is just an ordinary non-member function. Nothing can
1960 be a specialization of that. */
1961 ;
1963 /* Cannot specialize functions that are created implicitly. */
1964 ;
1965 else
1966 {
1967 tree decl_arg_types;
1969 /* This is an ordinary member function. However, since
1970 we're here, we can assume it's enclosing class is a
1971 template class. For example,
1973 template <typename T> struct S { void f(); };
1974 template <> void S<int>::f() {}
1976 Here, S<int>::f is a non-template, but S<int> is a
1977 template class. If FN has the same type as DECL, we
1978 might be in business. */
1981 /* Its enclosing class is an explicit specialization
1982 of a template class. This is not a candidate. */
1987 /* The return types differ. */
1990 /* Adjust the type of DECL in case FN is a static member. */
1997 decl_arg_types))
1998 /* They match! */
2000 }
2001 }
2004 {
2005 /* We have:
2007 [temp.expl.spec]
2009 It is possible for a specialization with a given function
2010 signature to be instantiated from more than one function
2011 template. In such cases, explicit specification of the
2012 template arguments must be used to uniquely identify the
2013 function template specialization being specialized.
2015 Note that here, there's no suggestion that we're supposed to
2016 determine which of the candidate templates is most
2017 specialized. However, we, also have:
2019 [temp.func.order]
2021 Partial ordering of overloaded function template
2022 declarations is used in the following contexts to select
2023 the function template to which a function template
2024 specialization refers:
2026 -- when an explicit specialization refers to a function
2027 template.
2029 So, we do use the partial ordering rules, at least for now.
2030 This extension can only serve to make invalid programs valid,
2031 so it's safe. And, there is strong anecdotal evidence that
2032 the committee intended the partial ordering rules to apply;
2033 the EDG front end has that behavior, and John Spicer claims
2034 that the committee simply forgot to delete the wording in
2035 [temp.expl.spec]. */
2038 {
2041 }
2042 }
2045 {
2053 }
2057 {
2063 }
2065 /* We have one, and exactly one, match. */
2067 {
2070 /* DECL is a re-declaration or partial instantiation of a template
2071 function. */
2074 /* It was a specialization of an ordinary member function in a
2075 template class. */
2077 }
2079 /* It was a specialization of a template. */
2082 {
2087 }
2088 else
2091 }
2093 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2094 but with the default argument values filled in from those in the
2095 TMPL_TYPES. */
2097 static tree
2099 tree tmpl_types)
2100 {
2101 tree new_spec_types;
2109 /* Substitute into the rest of the list. */
2110 new_spec_types =
2114 /* Add the default argument for this parameter. */
2117 new_spec_types);
2118 }
2120 /* DECL is an explicit specialization. Replicate default arguments
2121 from the template it specializes. (That way, code like:
2123 template <class T> void f(T = 3);
2124 template <> void f(double);
2125 void g () { f (); }
2127 works, as required.) An alternative approach would be to look up
2128 the correct default arguments at the call-site, but this approach
2129 is consistent with how implicit instantiations are handled. */
2131 static void
2133 {
2134 tree tmpl;
2135 tree spec_types;
2136 tree tmpl_types;
2137 tree new_spec_types;
2138 tree old_type;
2139 tree new_type;
2140 tree t;
2145 /* See if there's anything we need to do. */
2158 {
2159 /* Remove the this pointer, but remember the object's type for
2160 CV quals. */
2166 {
2167 /* DECL may contain more parameters than TMPL due to the extra
2168 in-charge parameter in constructors and destructors. */
2171 }
2173 {
2176 }
2177 }
2179 /* Compute the merged default arguments. */
2180 new_spec_types =
2183 /* Compute the new FUNCTION_TYPE. */
2185 {
2189 new_spec_types);
2192 /* Put the in-charge parameter back. */
2195 new_spec_types);
2199 new_spec_types);
2200 }
2201 else
2203 new_spec_types);
2209 }
2211 /* Return the number of template headers we expect to see for a definition
2212 or specialization of CTYPE or one of its non-template members. */
2214 int
2216 {
2220 {
2221 /* You're supposed to have one `template <...>' for every
2222 template class, but you don't need one for a full
2223 specialization. For example:
2225 template <class T> struct S{};
2226 template <> struct S<int> { void f(); };
2227 void S<int>::f () {}
2229 is correct; there shouldn't be a `template <>' for the
2230 definition of `S<int>::f'. */
2233 /* T is an explicit (not partial) specialization. All
2234 containing classes must therefore also be explicitly
2235 specialized. */
2243 }
2246 }
2248 /* Do a simple sanity check on the template headers that precede the
2249 variable declaration DECL. */
2251 void
2253 {
2260 {
2266 "members of an explicitly specialized class are defined "
2268 }
2269 }
2271 /* Check to see if the function just declared, as indicated in
2272 DECLARATOR, and in DECL, is a specialization of a function
2273 template. We may also discover that the declaration is an explicit
2274 instantiation at this point.
2276 Returns DECL, or an equivalent declaration that should be used
2277 instead if all goes well. Issues an error message if something is
2278 amiss. Returns error_mark_node if the error is not easily
2279 recoverable.
2281 FLAGS is a bitmask consisting of the following flags:
2283 2: The function has a definition.
2284 4: The function is a friend.
2286 The TEMPLATE_COUNT is the number of references to qualifying
2287 template classes that appeared in the name of the function. For
2288 example, in
2290 template <class T> struct S { void f(); };
2291 void S<int>::f();
2293 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2294 classes are not counted in the TEMPLATE_COUNT, so that in
2296 template <class T> struct S {};
2297 template <> struct S<int> { void f(); }
2298 template <> void S<int>::f();
2300 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2301 invalid; there should be no template <>.)
2303 If the function is a specialization, it is marked as such via
2304 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2305 is set up correctly, and it is added to the list of specializations
2306 for that template. */
2308 tree
2310 tree decl,
2313 {
2321 tmpl_spec_kind tsk;
2324 {
2327 else
2329 }
2330 else
2334 {
2337 {
2340 }
2342 {
2344 /* This could be something like:
2346 template <class T> void f(T);
2347 class S { friend void f<>(int); } */
2349 else
2350 {
2351 /* This case handles bogus declarations like template <>
2352 template <class T> void f<int>(); */
2355 declarator);
2357 }
2358 }
2362 /* The error has already been reported in
2363 check_specialization_scope. */
2369 /* Fall through. */
2382 decl);
2385 else
2389 /* Fall through. */
2394 else
2400 {
2401 /* This case handles bogus declarations like template <>
2402 template <class T> void f<int>(); */
2407 else
2409 declarator);
2411 }
2414 /* This is a specialization of a member template, without
2415 specialization the containing class. Something like:
2417 template <class T> struct S {
2418 template <class U> void f (U);
2419 };
2420 template <> template <class U> void S<int>::f(U) {}
2422 That's a specialization -- but of the entire template. */
2428 }
2431 {
2435 {
2439 }
2440 }
2443 {
2447 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2449 {
2450 tree fns;
2455 else
2456 {
2457 /* If there is no class context, the explicit instantiation
2458 must be at namespace scope. */
2461 /* Find the namespace binding, using the declaration
2462 context. */
2466 {
2469 }
2470 else
2471 {
2477 }
2478 }
2481 }
2487 {
2489 /* A specialization in class scope. This is invalid,
2490 but the error will already have been flagged by
2491 check_specialization_scope. */
2493 else
2494 {
2495 /* It's not valid to write an explicit instantiation in
2496 class scope, e.g.:
2498 class C { template void f(); }
2500 This case is caught by the parser. However, on
2501 something like:
2503 template class C { void f(); };
2505 (which is invalid) we can get here. The error will be
2506 issued later. */
2507 ;
2508 }
2511 }
2514 IDENTIFIER_NODE))
2515 {
2516 /* Find the list of functions in ctype that have the same
2517 name as the declared function. */
2523 {
2528 {
2529 /* From [temp.expl.spec]:
2531 If such an explicit specialization for the member
2532 of a class template names an implicitly-declared
2533 special member function (clause _special_), the
2534 program is ill-formed.
2536 Similar language is found in [temp.explicit]. */
2539 }
2542 }
2545 {
2549 }
2550 else
2551 {
2553 tree ovl;
2555 /* For a type-conversion operator, we cannot do a
2556 name-based lookup. We might be looking for `operator
2557 int' which will be a specialization of `operator T'.
2558 So, we find *all* the conversion operators, and then
2559 select from them. */
2567 {
2569 /* There are no more conversion functions. */
2572 /* Glue all these conversion functions together
2573 with those we already have. */
2576 }
2577 }
2580 {
2583 }
2584 else
2586 }
2588 /* Figure out what exactly is being specialized at this point.
2589 Note that for an explicit instantiation, even one for a
2590 member function, we cannot tell apriori whether the
2591 instantiation is for a member template, or just a member
2592 function of a template class. Even if a member template is
2593 being instantiated, the member template arguments may be
2594 elided if they can be deduced from the rest of the
2595 declaration. */
2598 member_specialization,
2599 template_count,
2600 tsk);
2603 /* We couldn't figure out what this declaration was
2604 specializing. */
2606 else
2607 {
2611 {
2612 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2613 is done by do_decl_instantiation later. */
2619 {
2620 /* If TMPL is not the most general template (for
2621 example, if TMPL is a friend template that is
2622 injected into namespace scope), then there will
2623 be too many levels of TARGS. Remove some of them
2624 here. */
2626 tree new_targs;
2633 }
2636 }
2638 /* If we thought that the DECL was a member function, but it
2639 turns out to be specializing a static member function,
2640 make DECL a static member function as well. */
2645 /* If this is a specialization of a member template of a
2646 template class, we want to return the TEMPLATE_DECL, not
2647 the specialization of it. */
2649 {
2654 {
2655 tree parm;
2659 /* We want to use the argument list specified in the
2660 definition, not in the original declaration. */
2665 }
2668 }
2670 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2673 /* Inherit default function arguments from the template
2674 DECL is specializing. */
2677 /* This specialization has the same protection as the
2678 template it specializes. */
2682 /* 7.1.1-1 [dcl.stc]
2684 A storage-class-specifier shall not be specified in an
2685 explicit specialization...
2687 The parser rejects these, so unless action is taken here,
2688 explicit function specializations will always appear with
2689 global linkage.
2691 The action recommended by the C++ CWG in response to C++
2692 defect report 605 is to make the storage class and linkage
2693 of the explicit specialization match the templated function:
2695 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2696 */
2698 {
2702 /* This specialization has the same linkage and visibility as
2703 the function template it specializes. */
2706 {
2709 }
2712 {
2715 }
2716 }
2718 /* If DECL is a friend declaration, declared using an
2719 unqualified name, the namespace associated with DECL may
2720 have been set incorrectly. For example, in:
2722 template <typename T> void f(T);
2723 namespace N {
2724 struct S { friend void f<int>(int); }
2725 }
2727 we will have set the DECL_CONTEXT for the friend
2728 declaration to N, rather than to the global namespace. */
2733 /* This is not really a declaration of a specialization.
2734 It's just the name of an instantiation. But, it's not
2735 a request for an instantiation, either. */
2738 /* This is indeed a specialization. In case of constructors
2739 and destructors, we need in-charge and not-in-charge
2740 versions in V3 ABI. */
2743 /* Register this specialization so that we can find it
2744 again. */
2746 }
2747 }
2750 }
2752 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2753 parameters. These are represented in the same format used for
2754 DECL_TEMPLATE_PARMS. */
2756 int
2758 {
2759 const_tree p1;
2760 const_tree p2;
2768 {
2780 {
2784 /* If either of the template parameters are invalid, assume
2785 they match for the sake of error recovery. */
2798 }
2799 }
2802 /* One set of parameters has more parameters lists than the
2803 other. */
2807 }
2809 /* Determine whether PARM is a parameter pack. */
2811 bool
2813 {
2814 /* Determine if we have a non-type template parameter pack. */
2821 /* If this is a list of template parameters, we could get a
2822 TYPE_DECL or a TEMPLATE_DECL. */
2826 /* Otherwise it must be a type template parameter. */
2830 }
2832 /* Determine if T is a function parameter pack. */
2834 bool
2836 {
2840 }
2842 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2843 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2845 tree
2847 {
2854 }
2856 /* Return true iff the function parameter PARAM_DECL was expanded
2857 from the function parameter pack PACK. */
2859 bool
2861 {
2866 /* The parameter pack and its pack arguments have the same
2867 DECL_PARM_INDEX. */
2869 }
2871 /* Determine whether ARGS describes a variadic template args list,
2872 i.e., one that is terminated by a template argument pack. */
2874 static bool
2876 {
2878 tree last_parm;
2892 }
2894 /* Generate a new name for the parameter pack name NAME (an
2895 IDENTIFIER_NODE) that incorporates its */
2897 static tree
2899 {
2900 /* Munge the name to include the parameter index. */
2901 #define NUMBUF_LEN 128
2913 }
2915 /* Return true if T is a primary function, class or alias template
2916 instantiation. */
2918 bool
2920 {
2937 }
2939 /* Return true if PARM is a template template parameter. */
2941 bool
2943 {
2945 }
2947 /* Return true iff PARM is a DECL representing a type template
2948 parameter. */
2950 bool
2952 {
2957 }
2959 /* Return the template parameters of T if T is a
2960 primary template instantiation, NULL otherwise. */
2962 tree
2964 {
2969 parms = INNERMOST_TEMPLATE_PARMS
2973 }
2975 /* Return the template parameters of the LEVELth level from the full list
2976 of template parameters PARMS. */
2978 tree
2980 {
2981 tree p;
2992 }
2994 /* Returns the template arguments of T if T is a template instantiation,
2995 NULL otherwise. */
2997 tree
2999 {
3007 }
3009 /* Return the argument pack elements of T if T is a template argument pack,
3010 NULL otherwise. */
3012 tree
3014 {
3020 }
3022 /* Structure used to track the progress of find_parameter_packs_r. */
3023 struct find_parameter_pack_data
3024 {
3025 /* TREE_LIST that will contain all of the parameter packs found by
3026 the traversal. */
3029 /* Set of AST nodes that have been visited by the traversal. */
3031 };
3033 /* Identifies all of the argument packs that occur in a template
3034 argument and appends them to the TREE_LIST inside DATA, which is a
3035 find_parameter_pack_data structure. This is a subroutine of
3036 make_pack_expansion and uses_parameter_packs. */
3037 static tree
3039 {
3045 /* Handle type aliases/typedefs. */
3050 {
3057 }
3059 /* Identify whether this is a parameter pack or not. */
3061 {
3076 {
3077 /* We don't want to walk into the type of a PARM_DECL,
3078 because we don't want to see the type parameter pack. */
3081 }
3088 /* Not a parameter pack. */
3090 }
3093 {
3094 /* Add this parameter pack to the list. */
3096 }
3102 /* This switch statement will return immediately if we don't find a
3103 parameter pack. */
3105 {
3110 /* Check the template itself. */
3113 /* Check the template arguments. */
3129 /* Fall through. */
3171 }
3174 }
3176 /* Determines if the expression or type T uses any parameter packs. */
3177 bool
3179 {
3187 }
3189 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3190 representation a base-class initializer into a parameter pack
3191 expansion. If all goes well, the resulting node will be an
3192 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3193 respectively. */
3194 tree
3196 {
3197 tree result;
3206 {
3207 /* The only time we will see a TREE_LIST here is for a base
3208 class initializer. In this case, the TREE_PURPOSE will be a
3209 _TYPE node (representing the base class expansion we're
3210 initializing) and the TREE_VALUE will be a TREE_LIST
3211 containing the initialization arguments.
3213 The resulting expansion looks somewhat different from most
3214 expansions. Rather than returning just one _EXPANSION, we
3215 return a TREE_LIST whose TREE_PURPOSE is a
3216 TYPE_PACK_EXPANSION containing the bases that will be
3217 initialized. The TREE_VALUE will be identical to the
3218 original TREE_VALUE, which is a list of arguments that will
3219 be passed to each base. We do not introduce any new pack
3220 expansion nodes into the TREE_VALUE (although it is possible
3221 that some already exist), because the TREE_PURPOSE and
3222 TREE_VALUE all need to be expanded together with the same
3223 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3224 resulting TREE_PURPOSE will mention the parameter packs in
3225 both the bases and the arguments to the bases. */
3226 tree purpose;
3227 tree value;
3230 /* Determine which parameter packs will be used by the base
3231 class expansion. */
3238 {
3242 }
3245 {
3246 /* Collect the sets of parameter packs used in each of the
3247 initialization arguments. */
3249 {
3250 /* Determine which parameter packs will be expanded in this
3251 argument. */
3254 }
3255 }
3259 /* Create the pack expansion type for the base type. */
3264 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3265 they will rarely be compared to anything. */
3269 }
3274 /* Build the PACK_EXPANSION_* node. */
3275 result = for_types
3280 {
3281 /* Propagate type and const-expression information. */
3284 }
3285 else
3286 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3287 they will rarely be compared to anything. */
3290 /* Determine which parameter packs will be expanded. */
3296 /* Make sure we found some parameter packs. */
3298 {
3301 else
3304 }
3310 }
3312 /* Checks T for any "bare" parameter packs, which have not yet been
3313 expanded, and issues an error if any are found. This operation can
3314 only be done on full expressions or types (e.g., an expression
3315 statement, "if" condition, etc.), because we could have expressions like:
3317 foo(f(g(h(args)))...)
3319 where "args" is a parameter pack. check_for_bare_parameter_packs
3320 should not be called for the subexpressions args, h(args),
3321 g(h(args)), or f(g(h(args))), because we would produce erroneous
3322 error messages.
3324 Returns TRUE and emits an error if there were bare parameter packs,
3325 returns FALSE otherwise. */
3326 bool
3328 {
3344 {
3347 {
3356 else
3361 else
3365 }
3368 }
3371 }
3373 /* Expand any parameter packs that occur in the template arguments in
3374 ARGS. */
3375 tree
3377 {
3383 /* First, determine if we need to expand anything, and the number of
3384 slots we'll need. */
3386 {
3391 {
3395 else
3397 }
3398 else
3399 {
3401 num_result_args++;
3402 }
3403 }
3405 /* If no expansion is necessary, we're done. */
3409 /* Expand arguments. */
3412 non_default_args_count =
3415 {
3418 {
3425 }
3426 else
3427 {
3430 }
3431 }
3435 }
3437 /* Checks if DECL shadows a template parameter.
3439 [temp.local]: A template-parameter shall not be redeclared within its
3440 scope (including nested scopes).
3442 Emits an error and returns TRUE if the DECL shadows a parameter,
3443 returns FALSE otherwise. */
3445 bool
3447 {
3448 tree olddecl;
3450 /* If we're not in a template, we can't possibly shadow a template
3451 parameter. */
3455 /* Figure out what we're shadowing. */
3460 /* If there's no previous binding for this name, we're not shadowing
3461 anything, let alone a template parameter. */
3465 /* If we're not shadowing a template parameter, we're done. Note
3466 that OLDDECL might be an OVERLOAD (or perhaps even an
3467 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3468 node. */
3472 /* We check for decl != olddecl to avoid bogus errors for using a
3473 name inside a class. We check TPFI to avoid duplicate errors for
3474 inline member templates. */
3482 }
3484 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3485 ORIG_LEVEL, DECL, and TYPE. */
3487 static tree
3491 tree decl,
3492 tree type)
3493 {
3504 }
3506 /* Find the canonical type parameter for the given template type
3507 parameter. Returns the canonical type parameter, which may be TYPE
3508 if no such parameter existed. */
3510 static tree
3512 {
3513 tree list;
3527 else
3528 {
3533 }
3534 }
3536 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3537 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3538 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3539 new one is created. */
3541 static tree
3543 tsubst_flags_t complain)
3544 {
3549 {
3568 /* Template template parameters need this. */
3573 }
3576 }
3578 /* Process information from new template parameter PARM and append it
3579 to the LIST being built. This new parameter is a non-type
3580 parameter iff IS_NON_TYPE is true. This new parameter is a
3581 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3582 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3583 parameter list PARM belongs to. This is used used to create a
3584 proper canonical type for the type of PARM that is to be created,
3585 iff PARM is a type. If the size is not known, this parameter shall
3586 be set to 0. */
3588 tree
3591 {
3593 tree defval;
3594 tree err_parm_list;
3601 {
3605 {
3609 else
3611 }
3614 }
3615 else
3619 {
3625 {
3629 }
3630 else
3631 {
3632 /* [temp.param]
3634 The top-level cv-qualifiers on the template-parameter are
3635 ignored when determining its type. */
3638 {
3642 }
3645 {
3646 /* This template parameter is not a parameter pack, but it
3647 should be. Complain about "bare" parameter packs. */
3650 /* Recover by calling this a parameter pack. */
3652 }
3653 }
3655 /* A template parameter is not modifiable. */
3664 processing_template_decl,
3669 }
3670 else
3671 {
3672 tree t;
3676 {
3678 /* This is for distinguishing between real templates and template
3679 template parameters */
3683 }
3684 else
3685 {
3687 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3690 }
3697 processing_template_decl,
3701 }
3707 }
3709 /* The end of a template parameter list has been reached. Process the
3710 tree list into a parameter vector, converting each parameter into a more
3711 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3712 as PARM_DECLs. */
3714 tree
3716 {
3721 current_template_parms
3726 {
3730 }
3735 }
3737 /* end_template_decl is called after a template declaration is seen. */
3739 void
3741 {
3747 /* This matches the pushlevel in begin_template_parm_list. */
3752 }
3754 /* Takes a TREE_LIST representing a template parameter and convert it
3755 into an argument suitable to be passed to the type substitution
3756 functions. Note that If the TREE_LIST contains an error_mark
3757 node, the returned argument is error_mark_node. */
3759 static tree
3761 {
3774 {
3778 {
3779 /* Turn this argument into a TYPE_ARGUMENT_PACK
3780 with a single element, which expands T. */
3782 #ifdef ENABLE_CHECKING
3783 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3785 #endif
3790 }
3791 }
3792 else
3793 {
3797 {
3798 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3799 with a single element, which expands T. */
3802 #ifdef ENABLE_CHECKING
3803 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3805 #endif
3811 }
3812 }
3814 }
3816 /* This function returns TRUE if PARM_PACK is a template parameter
3817 pack and if ARG_PACK is what template_parm_to_arg returned when
3818 passed PARM_PACK. */
3820 static bool
3822 {
3823 /* For clarity in the comments below let's use the representation
3824 argument_pack<elements>' to denote an argument pack and its
3825 elements.
3827 In the 'if' block below, we want to detect cases where
3828 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
3829 check if ARG_PACK is an argument pack which sole element is
3830 the expansion of PARM_PACK. That argument pack is typically
3831 created by template_parm_to_arg when passed a parameter
3832 pack. */
3837 {
3842 /* The argument pack that the parameter maps to is just an
3843 expansion of the parameter itself, such as one would
3844 find in the implicit typedef of a class inside the
3845 class itself. Consider this parameter "unsubstituted",
3846 so that we will maintain the outer pack expansion. */
3848 }
3850 }
3852 /* Within the declaration of a template, return all levels of template
3853 parameters that apply. The template parameters are represented as
3854 a TREE_VEC, in the form documented in cp-tree.h for template
3855 arguments. */
3857 static tree
3859 {
3860 tree header;
3865 /* If there is only one level of template parameters, we do not
3866 create a TREE_VEC of TREE_VECs. Instead, we return a single
3867 TREE_VEC containing the arguments. */
3872 {
3880 #ifdef ENABLE_CHECKING
3882 #endif
3886 else
3888 }
3891 /* This can happen for template parms of a template template
3892 parameter, e.g:
3894 template<template<class T, class U> class TT> struct S;
3896 Consider the level of the parms of TT; T and U both have
3897 level 2; TT has no template parm of level 1. So in this case
3898 the first element of full_template_args is NULL_TREE. If we
3899 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
3900 of 2. This will make tsubst wrongly consider that T and U
3901 have level 1. Instead, let's create a dummy vector as the
3902 first element of full_template_args so that TMPL_ARG_DEPTH
3903 returns the correct depth for args. */
3906 }
3908 /* Update the declared TYPE by doing any lookups which were thought to be
3909 dependent, but are not now that we know the SCOPE of the declarator. */
3911 tree
3913 {
3924 /* Don't bother building up the args in this case. */
3926 {
3927 /* tsubst in the args corresponding to the template parameters,
3928 including auto if present. Most things will be unchanged, but
3929 make_typename_type and tsubst_qualified_id will resolve
3930 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3933 tree pushed;
3935 {
3939 }
3944 }
3950 {
3953 else
3955 }
3957 }
3959 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3960 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3961 a member template. Used by push_template_decl below. */
3963 static tree
3965 {
3973 }
3975 struct template_parm_data
3976 {
3977 /* The level of the template parameters we are currently
3978 processing. */
3981 /* The index of the specialization argument we are currently
3982 processing. */
3985 /* An array whose size is the number of template parameters. The
3986 elements are nonzero if the parameter has been used in any one
3987 of the arguments processed so far. */
3990 /* An array whose size is the number of template arguments. The
3991 elements are nonzero if the argument makes use of template
3992 parameters of this level. */
3994 };
3996 /* Subroutine of push_template_decl used to see if each template
3997 parameter in a partial specialization is used in the explicit
3998 argument list. If T is of the LEVEL given in DATA (which is
3999 treated as a template_parm_data*), then DATA->PARMS is marked
4000 appropriately. */
4002 static int
4004 {
4010 {
4013 }
4014 else
4015 {
4018 }
4021 {
4024 }
4026 /* Return zero so that for_each_template_parm will continue the
4027 traversal of the tree; we want to mark *every* template parm. */
4029 }
4031 /* Process the partial specialization DECL. */
4033 static tree
4035 {
4041 tree inner_parms;
4042 tree inst;
4055 /* We check that each of the template parameters given in the
4056 partial specialization is used in the argument list to the
4057 specialization. For example:
4059 template <class T> struct S;
4060 template <class T> struct S<T*>;
4062 The second declaration is OK because `T*' uses the template
4063 parameter T, whereas
4065 template <class T> struct S<int>;
4067 is no good. Even trickier is:
4069 template <class T>
4070 struct S1
4071 {
4072 template <class U>
4073 struct S2;
4074 template <class U>
4075 struct S2<T>;
4076 };
4078 The S2<T> declaration is actually invalid; it is a
4079 full-specialization. Of course,
4081 template <class U>
4082 struct S2<T (*)(U)>;
4084 or some such would have been OK. */
4092 {
4097 NULL,
4099 }
4102 {
4103 /* One of the template parms was not used in the
4104 specialization. */
4106 {
4109 }
4112 }
4117 /* [temp.class.spec]
4119 The argument list of the specialization shall not be identical to
4120 the implicit argument list of the primary template. */
4127 /* A partial specialization that replaces multiple parameters of the
4128 primary template with a pack expansion is less specialized for those
4129 parameters. */
4131 {
4133 "primary template because it replaces multiple parameters "
4137 }
4139 /* [temp.class.spec]
4141 A partially specialized non-type argument expression shall not
4142 involve template parameters of the partial specialization except
4143 when the argument expression is a simple identifier.
4145 The type of a template parameter corresponding to a specialized
4146 non-type argument shall not be dependent on a parameter of the
4147 specialization.
4149 Also, we verify that pack expansions only occur at the
4150 end of the argument list. */
4154 {
4161 {
4162 /* Extract the arguments from the argument pack. We'll be
4163 iterating over these in the following loop. */
4166 }
4169 {
4171 /* Get the Jth argument in the parameter pack. */
4175 {
4176 /* Pack expansions must come at the end of the
4177 argument list. */
4180 {
4184 else
4187 }
4188 }
4191 /* We only care about the pattern. */
4197 /* This next line is the `argument expression is not just a
4198 simple identifier' condition and also the `specialized
4199 non-type argument' bit. */
4201 {
4205 arg);
4206 else
4207 {
4208 /* Look at the corresponding template parameter,
4209 marking which template parameters its type depends
4210 upon. */
4214 {
4215 /* We haven't yet initialized TPD2. Do so now. */
4217 /* The number of parameters here is the number in the
4218 main template, which, as checked in the assertion
4219 above, is NARGS. */
4223 }
4225 /* Mark the template parameters. But this time, we're
4226 looking for the template parameters of the main
4227 template, not in the specialization. */
4234 NULL,
4238 {
4239 /* The type depended on some template parameters.
4240 If they are fully specialized in the
4241 specialization, that's OK. */
4250 "type %qT of template argument %qE depends "
4252 "type %qT of template argument %qE depends "
4254 type,
4255 arg);
4256 }
4257 }
4258 }
4259 }
4260 }
4262 /* We should only get here once. */
4272 {
4276 {
4280 "partial specialization of %qT after instantiation "
4282 }
4283 }
4286 }
4288 /* Check that a template declaration's use of default arguments and
4289 parameter packs is not invalid. Here, PARMS are the template
4290 parameters. IS_PRIMARY is true if DECL is the thing declared by
4291 a primary template. IS_PARTIAL is true if DECL is a partial
4292 specialization.
4294 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4295 declaration (but not a definition); 1 indicates a declaration, 2
4296 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4297 emitted for extraneous default arguments.
4299 Returns TRUE if there were no errors found, FALSE otherwise. */
4301 bool
4304 {
4307 tree parm_level;
4310 /* [temp.param]
4312 A default template-argument shall not be specified in a
4313 function template declaration or a function template definition, nor
4314 in the template-parameter-list of the definition of a member of a
4315 class template. */
4318 /* You can't have a function template declaration in a local
4319 scope, nor you can you define a member of a class template in a
4320 local scope. */
4327 /* If this is either a friend defined in the scope of the class
4328 or a member function. */
4334 /* And, if it was a member function, it really was defined in
4335 the scope of the class. */
4338 /* We already checked these parameters when the template was
4339 declared, so there's no need to do it again now. This function
4340 was defined in class scope, but we're processing it's body now
4341 that the class is complete. */
4344 /* Core issue 226 (C++0x only): the following only applies to class
4345 templates. */
4348 {
4349 /* [temp.param]
4351 If a template-parameter has a default template-argument, all
4352 subsequent template-parameters shall have a default
4353 template-argument supplied. */
4355 {
4362 {
4372 {
4374 /* For better subsequent error-recovery, we indicate that
4375 there should have been a default argument. */
4378 }
4380 && !is_friend_decl
4381 /* Don't complain about an enclosing partial
4382 specialization. */
4387 {
4388 /* A primary class template can only have one
4389 parameter pack, at the end of the template
4390 parameter list. */
4395 else
4403 }
4404 }
4405 }
4406 }
4409 || is_partial
4410 || !is_primary
4412 /* For an ordinary class template, default template arguments are
4413 allowed at the innermost level, e.g.:
4414 template <class T = int>
4415 struct S {};
4416 but, in a partial specialization, they're not allowed even
4417 there, as we have in [temp.class.spec]:
4419 The template parameter list of a specialization shall not
4420 contain default template argument values.
4422 So, for a partial specialization, or for a function template
4423 (in C++98/C++03), we look at all of them. */
4424 ;
4425 else
4426 /* But, for a primary class template that is not a partial
4427 specialization we look at all template parameters except the
4428 innermost ones. */
4431 /* Figure out what error message to issue. */
4444 else
4448 /* If we're inside a class definition, there's no need to
4449 examine the parameters to the class itself. On the one
4450 hand, they will be checked when the class is defined, and,
4451 on the other, default arguments are valid in things like:
4452 template <class T = double>
4453 struct S { template <class U> void f(U); };
4454 Here the default argument for `S' has no bearing on the
4455 declaration of `f'. */
4457 else
4458 /* Check everything. */
4464 {
4471 {
4476 {
4478 {
4485 }
4487 /* Clear out the default argument so that we are not
4488 confused later. */
4490 }
4491 }
4493 /* At this point, if we're still interested in issuing messages,
4494 they must apply to classes surrounding the object declared. */
4498 }
4501 }
4503 /* Worker for push_template_decl_real, called via
4504 for_each_template_parm. DATA is really an int, indicating the
4505 level of the parameters we are interested in. If T is a template
4506 parameter of that level, return nonzero. */
4508 static int
4510 {
4516 else
4519 }
4521 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4522 parameters given by current_template_args, or reuses a
4523 previously existing one, if appropriate. Returns the DECL, or an
4524 equivalent one, if it is replaced via a call to duplicate_decls.
4526 If IS_FRIEND is true, DECL is a friend declaration. */
4528 tree
4530 {
4531 tree tmpl;
4532 tree args;
4533 tree info;
4534 tree ctx;
4538 /* True if the template is a member template, in the sense of
4539 [temp.mem]. */
4545 /* See if this is a partial specialization. */
4554 /* For a friend, we want the context of the friend function, not
4555 the type of which it is a friend. */
4559 /* In the case of a virtual function, we want the class in which
4560 it is defined. */
4562 else
4563 /* Otherwise, if we're currently defining some class, the DECL
4564 is assumed to be a member of the class. */
4573 /* See if this is a primary template. */
4575 /* A friend template that specifies a class context, i.e.
4576 template <typename T> friend void A<T>::f();
4577 is not primary. */
4579 else
4583 {
4588 {
4591 }
4593 {
4595 {
4596 /* [temp.mem]
4598 A destructor shall not be a member template. */
4601 }
4608 {
4609 /* [basic.stc.dynamic.allocation]
4611 An allocation function can be a function
4612 template. ... Template allocation functions shall
4613 have two or more parameters. */
4616 }
4617 }
4623 /* alias-declaration */
4625 else
4626 {
4629 }
4630 }
4632 /* Check to see that the rules regarding the use of default
4633 arguments are not being violated. */
4637 /* Ensure that there are no parameter packs in the type of this
4638 declaration that have not been expanded. */
4640 {
4641 /* Check each of the arguments individually to see if there are
4642 any bare parameter packs. */
4648 {
4651 {
4652 /* This is a PARM_DECL that contains unexpanded parameter
4653 packs. We have already complained about this in the
4654 check_for_bare_parameter_packs call, so just replace
4655 these types with ERROR_MARK_NODE. */
4658 }
4662 }
4664 /* Check for bare parameter packs in the return type and the
4665 exception specifiers. */
4667 /* Errors were already issued, set return type to int
4668 as the frontend doesn't expect error_mark_node as
4669 the return type. */
4673 }
4678 {
4681 }
4692 {
4697 /* If DECL is a TYPE_DECL for a class-template, then there won't
4698 be DECL_LANG_SPECIFIC. The information equivalent to
4699 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4703 {
4704 /* Since a template declaration already existed for this
4705 class-type, we must be redeclaring it here. Make sure
4706 that the redeclaration is valid. */
4708 current_template_parms);
4709 /* We don't need to create a new TEMPLATE_DECL; just use the
4710 one we already had. */
4712 }
4713 else
4714 {
4716 member_template_p);
4721 {
4722 /* A specialization of a member template of a template
4723 class. */
4727 }
4728 }
4729 }
4730 else
4731 {
4737 {
4740 }
4748 {
4749 tree new_tmpl;
4751 /* The declaration is a specialization of a member
4752 template, declared outside the class. Therefore, the
4753 innermost template arguments will be NULL, so we
4754 replace them with the arguments determined by the
4755 earlier call to check_explicit_specialization. */
4758 new_tmpl
4760 member_template_p);
4770 args,
4773 }
4775 /* Make sure the template headers we got make sense. */
4780 {
4783 }
4784 else
4786 {
4791 {
4795 else
4800 }
4805 /* Can happen in erroneous input. */
4807 else
4811 }
4813 /* Check that the parms are used in the appropriate qualifying scopes
4814 in the declarator. */
4818 {
4824 /* Avoid crash in import_export_decl. */
4827 }
4828 }
4833 /* Push template declarations for global functions and types. Note
4834 that we do not try to push a global template friend declared in a
4835 template class; such a thing may well depend on the template
4836 parameters of the class. */
4839 {
4844 /* Hide template friend classes that haven't been declared yet. */
4846 {
4849 }
4850 }
4853 {
4859 {
4862 /* It is a conversion operator. See if the type converted to
4863 depends on innermost template operands. */
4866 depth))
4868 }
4870 /* Give template template parms a DECL_CONTEXT of the template
4871 for which they are a parameter. */
4874 {
4878 }
4879 }
4881 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4882 back to its most general template. If TMPL is a specialization,
4883 ARGS may only have the innermost set of arguments. Add the missing
4884 argument levels if necessary. */
4892 else
4893 {
4898 }
4901 }
4903 tree
4905 {
4907 }
4909 /* Called when a class template TYPE is redeclared with the indicated
4910 template PARMS, e.g.:
4912 template <class T> struct S;
4913 template <class T> struct S {}; */
4915 bool
4917 {
4918 tree tmpl;
4919 tree tmpl_parms;
4923 {
4926 }
4930 /* The type is nested in some template class. Nothing to worry
4931 about here; there are no new template parameters for the nested
4932 type. */
4936 {
4938 tmpl);
4940 }
4946 {
4956 }
4959 {
4960 tree tmpl_parm;
4961 tree parm;
4962 tree tmpl_default;
4963 tree parm_default;
4977 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4978 TEMPLATE_DECL. */
4988 {
4992 }
4995 {
4996 /* We have in [temp.param]:
4998 A template-parameter may not be given default arguments
4999 by two different declarations in the same scope. */
5004 }
5007 /* Update the previous template parameters (which are the ones
5008 that will really count) with the new default value. */
5011 /* Update the new parameters, too; they'll be used as the
5012 parameters for any members. */
5014 }
5017 }
5019 /* Simplify EXPR if it is a non-dependent expression. Returns the
5020 (possibly simplified) expression. */
5022 static tree
5024 {
5028 /* If we're in a template, but EXPR isn't value dependent, simplify
5029 it. We're supposed to treat:
5031 template <typename T> void f(T[1 + 1]);
5032 template <typename T> void f(T[2]);
5034 as two declarations of the same function, for example. */
5039 {
5040 HOST_WIDE_INT saved_processing_template_decl;
5046 complain,
5051 }
5053 }
5055 tree
5057 {
5059 }
5061 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5062 template declaration, or a TYPE_DECL for an alias declaration. */
5064 bool
5066 {
5074 }
5076 /* Return TRUE iff is a specialization of an alias template. */
5078 bool
5080 {
5085 }
5087 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5088 must be a function or a pointer-to-function type, as specified
5089 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5090 and check that the resulting function has external linkage. */
5092 static tree
5094 {
5097 linkage_kind linkage;
5109 /* [temp.arg.nontype]/1
5111 A template-argument for a non-type, non-template template-parameter
5112 shall be one of:
5113 [...]
5114 -- the address of an object or function with external [C++11: or
5115 internal] linkage. */
5118 {
5123 else
5128 }
5131 }
5133 /* Subroutine of convert_nontype_argument.
5134 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5135 Emit an error otherwise. */
5137 static bool
5139 tsubst_flags_t complain)
5140 {
5147 {
5151 }
5153 }
5155 /* Returns TRUE iff the address of OP is value-dependent.
5157 14.6.2.4 [temp.dep.temp]:
5158 A non-integral non-type template-argument is dependent if its type is
5159 dependent or it has either of the following forms
5160 qualified-id
5161 & qualified-id
5162 and contains a nested-name-specifier which specifies a class-name that
5163 names a dependent type.
5165 We generalize this to just say that the address of a member of a
5166 dependent class is value-dependent; the above doesn't cover the
5167 address of a static data member named with an unqualified-id. */
5169 static bool
5171 {
5172 /* We could use get_inner_reference here, but there's no need;
5173 this is only relevant for template non-type arguments, which
5174 can only be expressed as &id-expression. */
5176 {
5180 }
5183 }
5185 /* The next set of functions are used for providing helpful explanatory
5186 diagnostics for failed overload resolution. Their messages should be
5187 indented by two spaces for consistency with the messages in
5188 call.c */
5190 static int
5192 {
5194 }
5196 static int
5198 {
5203 }
5205 static int
5207 {
5209 }
5211 static int
5213 {
5219 }
5221 static int
5223 {
5227 }
5229 static int
5231 {
5234 " template parameter %qD is not a parameter pack, but "
5238 }
5240 static int
5242 {
5245 " template argument %qE does not match "
5249 }
5251 static int
5253 {
5257 }
5259 static int
5261 {
5267 }
5269 static int
5271 {
5273 {
5278 else
5280 " deduced conflicting values for non-type parameter "
5282 }
5284 }
5286 static int
5288 {
5291 " variable-sized array type %qT is not "
5293 arg);
5295 }
5297 static int
5299 {
5303 arg);
5305 }
5307 static int
5309 {
5316 }
5318 static int
5320 {
5322 }
5324 static int
5326 {
5328 }
5330 static int
5333 {
5338 }
5340 static int
5343 {
5346 {
5354 }
5356 }
5358 static int
5360 {
5363 " template parameters of a template template argument are "
5366 }
5368 static int
5370 {
5376 }
5378 static int
5380 {
5385 }
5387 static int
5389 {
5393 arg);
5395 }
5397 /* Attempt to convert the non-type template parameter EXPR to the
5398 indicated TYPE. If the conversion is successful, return the
5399 converted value. If the conversion is unsuccessful, return
5400 NULL_TREE if we issued an error message, or error_mark_node if we
5401 did not. We issue error messages for out-and-out bad template
5402 parameters, but not simply because the conversion failed, since we
5403 might be just trying to do argument deduction. Both TYPE and EXPR
5404 must be non-dependent.
5406 The conversion follows the special rules described in
5407 [temp.arg.nontype], and it is much more strict than an implicit
5408 conversion.
5410 This function is called twice for each template argument (see
5411 lookup_template_class for a more accurate description of this
5412 problem). This means that we need to handle expressions which
5413 are not valid in a C++ source, but can be created from the
5414 first call (for instance, casts to perform conversions). These
5415 hacks can go away after we fix the double coercion problem. */
5417 static tree
5419 {
5420 tree expr_type;
5422 /* Detect immediately string literals as invalid non-type argument.
5423 This special-case is not needed for correctness (we would easily
5424 catch this later), but only to provide better diagnostic for this
5425 common user mistake. As suggested by DR 100, we do not mention
5426 linkage issues in the diagnostic as this is not the point. */
5427 /* FIXME we're making this OK. */
5429 {
5435 }
5437 /* Add the ADDR_EXPR now for the benefit of
5438 value_dependent_expression_p. */
5441 {
5445 }
5447 /* If we are in a template, EXPR may be non-dependent, but still
5448 have a syntactic, rather than semantic, form. For example, EXPR
5449 might be a SCOPE_REF, rather than the VAR_DECL to which the
5450 SCOPE_REF refers. Preserving the qualifying scope is necessary
5451 so that access checking can be performed when the template is
5452 instantiated -- but here we need the resolved form so that we can
5453 convert the argument. */
5464 else
5467 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5468 to a non-type argument of "nullptr". */
5472 /* In C++11, integral or enumeration non-type template arguments can be
5473 arbitrary constant expressions. Pointer and pointer to
5474 member arguments can be general constant expressions that evaluate
5475 to a null value, but otherwise still need to be of a specific form. */
5477 {
5479 /* A PTRMEM_CST is already constant, and a valid template
5480 argument for a parameter of pointer to member type, we just want
5481 to leave it in that form rather than lower it to a
5486 {
5491 }
5492 }
5494 /* HACK: Due to double coercion, we can get a
5495 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5496 which is the tree that we built on the first call (see
5497 below when coercing to reference to object or to reference to
5498 function). We just strip everything and get to the arg.
5499 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5500 for examples. */
5502 {
5508 {
5509 /* ??? Maybe we could use convert_from_reference here, but we
5510 would need to relax its constraints because the NOP_EXPR
5511 could actually change the type to something more cv-qualified,
5512 and this is not folded by convert_from_reference. */
5523 }
5524 }
5526 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5527 parameter is a pointer to object, through decay and
5528 qualification conversion. Let's strip everything. */
5530 {
5534 /* Skip the ADDR_EXPR only if it is part of the decay for
5535 an array. Otherwise, it is part of the original argument
5536 in the source code. */
5540 }
5542 /* [temp.arg.nontype]/5, bullet 1
5544 For a non-type template-parameter of integral or enumeration type,
5545 integral promotions (_conv.prom_) and integral conversions
5546 (_conv.integral_) are applied. */
5548 {
5557 /* Notice that there are constant expressions like '4 % 0' which
5558 do not fold into integer constants. */
5560 {
5562 {
5573 /* else cxx_constant_value complained but gave us
5574 a real constant, so go ahead. */
5576 }
5577 else
5579 }
5580 }
5581 /* [temp.arg.nontype]/5, bullet 2
5583 For a non-type template-parameter of type pointer to object,
5584 qualification conversions (_conv.qual_) and the array-to-pointer
5585 conversion (_conv.array_) are applied. */
5587 {
5588 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5590 A template-argument for a non-type, non-template template-parameter
5591 shall be one of: [...]
5593 -- the name of a non-type template-parameter;
5594 -- the address of an object or function with external linkage, [...]
5595 expressed as "& id-expression" where the & is optional if the name
5596 refers to a function or array, or if the corresponding
5597 template-parameter is a reference.
5599 Here, we do not care about functions, as they are invalid anyway
5600 for a parameter of type pointer-to-object. */
5603 /* Non-type template parameters are OK. */
5604 ;
5609 {
5611 {
5613 "because %qD is a variable, not the address of "
5617 }
5618 /* Other values, like integer constants, might be valid
5619 non-type arguments of some other type. */
5621 }
5622 else
5623 {
5624 tree decl;
5629 {
5634 }
5636 {
5641 }
5643 {
5648 }
5649 }
5658 }
5659 /* [temp.arg.nontype]/5, bullet 3
5661 For a non-type template-parameter of type reference to object, no
5662 conversions apply. The type referred to by the reference may be more
5663 cv-qualified than the (otherwise identical) type of the
5664 template-argument. The template-parameter is bound directly to the
5665 template-argument, which must be an lvalue. */
5667 {
5669 expr_type))
5673 {
5677 }
5680 {
5684 }
5686 /* [temp.arg.nontype]/1
5688 A template-argument for a non-type, non-template template-parameter
5689 shall be one of: [...]
5691 -- the address of an object or function with external linkage. */
5694 {
5697 {
5699 "because a reference variable does not have a constant "
5702 }
5703 }
5706 {
5711 }
5714 {
5719 }
5722 }
5723 /* [temp.arg.nontype]/5, bullet 4
5725 For a non-type template-parameter of type pointer to function, only
5726 the function-to-pointer conversion (_conv.func_) is applied. If the
5727 template-argument represents a set of overloaded functions (or a
5728 pointer to such), the matching function is selected from the set
5729 (_over.over_). */
5731 {
5732 /* If the argument is a template-id, we might not have enough
5733 context information to decay the pointer. */
5735 {
5739 }
5742 /* Null pointer values are OK in C++11. */
5750 {
5754 }
5755 }
5756 /* [temp.arg.nontype]/5, bullet 5
5758 For a non-type template-parameter of type reference to function, no
5759 conversions apply. If the template-argument represents a set of
5760 overloaded functions, the matching function is selected from the set
5761 (_over.over_). */
5763 {
5765 {
5770 }
5777 }
5778 /* [temp.arg.nontype]/5, bullet 6
5780 For a non-type template-parameter of type pointer to member function,
5781 no conversions apply. If the template-argument represents a set of
5782 overloaded member functions, the matching member function is selected
5783 from the set (_over.over_). */
5785 {
5790 /* [temp.arg.nontype] bullet 1 says the pointer to member
5791 expression must be a pointer-to-member constant. */
5795 /* There is no way to disable standard conversions in
5796 resolve_address_of_overloaded_function (called by
5797 instantiate_type). It is possible that the call succeeded by
5798 converting &B::I to &D::I (where B is a base of D), so we need
5799 to reject this conversion here.
5801 Actually, even if there was a way to disable standard conversions,
5802 it would still be better to reject them here so that we can
5803 provide a superior diagnostic. */
5805 {
5809 /* If we are just one standard conversion off, explain. */
5814 }
5815 }
5816 /* [temp.arg.nontype]/5, bullet 7
5818 For a non-type template-parameter of type pointer to data member,
5819 qualification conversions (_conv.qual_) are applied. */
5821 {
5822 /* [temp.arg.nontype] bullet 1 says the pointer to member
5823 expression must be a pointer-to-member constant. */
5830 }
5832 {
5834 {
5838 }
5840 }
5841 /* A template non-type parameter must be one of the above. */
5842 else
5845 /* Sanity check: did we actually convert the argument to the
5846 right type? */
5850 }
5852 /* Subroutine of coerce_template_template_parms, which returns 1 if
5853 PARM_PARM and ARG_PARM match using the rule for the template
5854 parameters of template template parameters. Both PARM and ARG are
5855 template parameters; the rest of the arguments are the same as for
5856 coerce_template_template_parms.
5857 */
5858 static int
5860 tree arg,
5861 tsubst_flags_t complain,
5862 tree in_decl,
5863 tree outer_args)
5864 {
5873 {
5875 /* We encounter instantiations of templates like
5876 template <template <template <class> class> class TT>
5877 class C; */
5878 {
5885 }
5886 /* Fall through. */
5891 /* Argument is a parameter pack but parameter is not. */
5896 /* The tsubst call is used to handle cases such as
5898 template <int> class C {};
5899 template <class T, template <T> class TT> class D {};
5900 D<int, C> d;
5902 i.e. the parameter list of TT depends on earlier parameters. */
5904 && !same_type_p
5911 /* Argument is a parameter pack but parameter is not. */
5918 }
5921 }
5924 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5925 template template parameters. Both PARM_PARMS and ARG_PARMS are
5926 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5927 or PARM_DECL.
5929 Consider the example:
5930 template <class T> class A;
5931 template<template <class U> class TT> class B;
5933 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5934 the parameters to A, and OUTER_ARGS contains A. */
5936 static int
5938 tree arg_parms,
5939 tsubst_flags_t complain,
5940 tree in_decl,
5941 tree outer_args)
5942 {
5953 /* Determine whether we have a parameter pack at the end of the
5954 template template parameter's template parameter list. */
5956 {
5963 {
5977 }
5978 }
5984 /* Check all of the template parameters except the parameter pack at
5985 the end (if any). */
5987 {
5996 outer_args))
5999 }
6002 {
6003 /* Check each of the template parameters in the template
6004 argument against the template parameter pack at the end of
6005 the template template parameter. */
6012 {
6019 outer_args))
6021 }
6022 }
6025 }
6027 /* Verifies that the deduced template arguments (in TARGS) for the
6028 template template parameters (in TPARMS) represent valid bindings,
6029 by comparing the template parameter list of each template argument
6030 to the template parameter list of its corresponding template
6031 template parameter, in accordance with DR150. This
6032 routine can only be called after all template arguments have been
6033 deduced. It will return TRUE if all of the template template
6034 parameter bindings are okay, FALSE otherwise. */
6035 bool
6037 {
6041 /* We're dealing with template parms in this process. */
6047 {
6052 {
6057 {
6058 /* Look inside the argument pack. */
6061 }
6064 {
6068 /* Extract the next argument from the argument
6069 pack. */
6073 /* Look at the pattern of the pack expansion. */
6076 /* Extract the template parameters from the template
6077 argument. */
6083 /* Verify that we can coerce the template template
6084 parameters from the template argument to the template
6085 parameter. This requires an exact match. */
6087 && !coerce_template_template_parms
6089 targ_parms,
6090 tf_none,
6091 tparm,
6092 targs))
6093 {
6096 }
6097 }
6098 }
6099 }
6101 out:
6105 }
6107 /* Since type attributes aren't mangled, we need to strip them from
6108 template type arguments. */
6110 static tree
6112 {
6113 tree mv;
6120 {
6125 }
6127 }
6129 /* Convert the indicated template ARG as necessary to match the
6130 indicated template PARM. Returns the converted ARG, or
6131 error_mark_node if the conversion was unsuccessful. Error and
6132 warning messages are issued under control of COMPLAIN. This
6133 conversion is for the Ith parameter in the parameter list. ARGS is
6134 the full set of template arguments deduced so far. */
6136 static tree
6138 tree arg,
6139 tree args,
6140 tsubst_flags_t complain,
6142 tree in_decl)
6143 {
6144 tree orig_arg;
6145 tree val;
6150 {
6151 /* The template argument was the name of some
6152 member function. That's usually
6153 invalid, but static members are OK. In any
6154 case, grab the underlying fields/functions
6155 and issue an error later if required. */
6158 }
6166 /* When determining whether an argument pack expansion is a template,
6167 look at the pattern. */
6171 /* Deal with an injected-class-name used as a template template arg. */
6173 {
6176 {
6186 }
6187 }
6189 is_tmpl_type =
6205 {
6207 {
6211 }
6214 "to refer to a type member of a template parameter, "
6219 typename_type,
6220 complain);
6223 }
6225 {
6227 {
6229 {
6239 else
6241 }
6242 }
6244 }
6246 {
6248 {
6254 else
6256 }
6258 }
6261 {
6263 {
6267 /* The number of argument required is not known yet.
6268 Just accept it for now. */
6270 else
6271 {
6273 tree argparm;
6279 args))
6280 {
6283 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6284 TEMPLATE_DECL. */
6286 {
6291 }
6292 }
6293 else
6294 {
6296 {
6302 }
6305 }
6306 }
6307 }
6308 else
6310 /* We only form one instance of each template specialization.
6311 Therefore, if we use a non-canonical variant (i.e., a
6312 typedef), any future messages referring to the type will use
6313 the typedef, which is confusing if those future uses do not
6314 themselves also use the typedef. */
6317 }
6318 else
6319 {
6326 {
6329 else
6330 {
6331 /* Not sure if this is reachable, but it doesn't hurt
6332 to be robust. */
6335 }
6336 }
6338 /* We used to call digest_init here. However, digest_init
6339 will report errors, which we don't want when complain
6340 is zero. More importantly, digest_init will try too
6341 hard to convert things: for example, `0' should not be
6342 converted to pointer type at this point according to
6343 the standard. Accepting this is not merely an
6344 extension, since deciding whether or not these
6345 conversions can occur is part of determining which
6346 function template to call, or whether a given explicit
6347 argument specification is valid. */
6349 else
6358 {
6359 /* Strip typedefs from the SCOPE_REF. */
6362 complain);
6365 }
6366 }
6369 }
6371 /* Coerces the remaining template arguments in INNER_ARGS (from
6372 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6373 Returns the coerced argument pack. PARM_IDX is the position of this
6374 parameter in the template parameter list. ARGS is the original
6375 template argument list. */
6376 static tree
6379 tree args,
6380 tree inner_args,
6382 tree new_args,
6384 tree in_decl,
6385 tsubst_flags_t complain)
6386 {
6389 tree packed_args;
6390 tree argument_pack;
6400 {
6401 /* When the template parameter is a non-type template
6402 parameter pack whose type uses parameter packs, we need
6403 to look at each of the template arguments
6404 separately. Build a vector of the types for these
6405 non-type template parameters in PACKED_TYPES. */
6406 tree expansion
6414 /* Check that we have the right number of arguments. */
6418 {
6419 int needed_parms
6424 }
6426 /* If we aren't able to check the actual arguments now
6427 (because they haven't been expanded yet), we can at least
6428 verify that all of the types used for the non-type
6429 template parameter pack are, in fact, valid for non-type
6430 template parameters. */
6433 {
6436 {
6440 }
6441 }
6442 }
6444 /* Convert the remaining arguments, which will be a part of the
6445 parameter pack "parm". */
6447 {
6452 {
6453 /* When we have a vector of types (corresponding to the
6454 non-type template parameter pack that uses parameter
6455 packs in its type, as mention above), and the
6456 argument is not an expansion (which expands to a
6457 currently unknown number of arguments), clone the
6458 parm and give it the next type in PACKED_TYPES. */
6462 }
6465 {
6468 }
6469 else
6472 in_decl);
6476 }
6481 else
6482 {
6487 }
6490 #ifdef ENABLE_CHECKING
6493 #endif
6495 }
6497 /* Returns true if the template argument vector ARGS contains
6498 any pack expansions, false otherwise. */
6500 static bool
6502 {
6509 }
6511 /* Convert all template arguments to their appropriate types, and
6512 return a vector containing the innermost resulting template
6513 arguments. If any error occurs, return error_mark_node. Error and
6514 warning messages are issued under control of COMPLAIN.
6516 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6517 for arguments not specified in ARGS. Otherwise, if
6518 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6519 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6520 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6521 ARGS. */
6523 static tree
6525 tree args,
6526 tree in_decl,
6527 tsubst_flags_t complain,
6530 {
6532 tree inner_args;
6533 tree new_args;
6534 tree new_inner_args;
6538 /* When used as a boolean value, indicates whether this is a
6539 variadic template parameter list. Since it's an int, we can also
6540 subtract it from nparms to get the number of non-variadic
6541 parameters. */
6550 /* Determine if there are any parameter packs. */
6552 {
6558 }
6561 /* If there are no parameters that follow a parameter pack, we need to
6562 expand any argument packs so that we can deduce a parameter pack from
6563 some non-packed args followed by an argument pack, as in variadic85.C.
6564 If there are such parameters, we need to leave argument packs intact
6565 so the arguments are assigned properly. This can happen when dealing
6566 with a nested class inside a partial specialization of a class
6567 template, as in variadic92.C, or when deducing a template parameter pack
6568 from a sub-declarator, as in variadic114.C. */
6575 && require_all_args
6577 && (!use_default_args
6580 {
6582 {
6584 {
6588 }
6589 else
6595 }
6598 }
6600 /* We need to evaluate the template arguments, even though this
6601 template-id may be nested within a "sizeof". */
6609 {
6610 tree arg;
6611 tree parm;
6613 /* Get the Ith template parameter. */
6617 {
6620 }
6622 /* Calculate the next argument. */
6625 else
6630 {
6631 /* All remaining arguments will be placed in the
6632 template parameter pack PARM. */
6638 /* Store this argument. */
6640 lost++;
6643 /* We are done with all of the arguments. */
6647 }
6649 {
6651 {
6652 /* We don't know how many args we have yet, just
6653 use the unconverted ones for now. */
6656 }
6657 }
6659 {
6660 /* There must be a default arg in this case. */
6663 /* The position of the first default template argument,
6664 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6665 Record that. */
6668 }
6669 else
6673 {
6676 }
6678 /* This only occurs if there was an error in the template
6679 parameter list itself (which we would already have
6680 reported) that we are trying to recover from, e.g., a class
6681 template with a parameter list such as
6682 template<typename..., typename>. */
6684 else
6690 lost++;
6692 }
6699 #ifdef ENABLE_CHECKING
6703 #endif
6706 }
6708 /* Returns 1 if template args OT and NT are equivalent. */
6710 static int
6712 {
6719 /* For member templates */
6728 {
6745 }
6747 {
6748 /* We get here probably because we are in the middle of substituting
6749 into the pattern of a pack expansion. In that case the
6750 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6751 interested in. So we want to use the initial pack argument for
6752 the comparison. */
6757 }
6762 else
6764 }
6766 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6767 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6768 NEWARG_PTR with the offending arguments if they are non-NULL. */
6770 static int
6773 {
6786 {
6791 {
6797 }
6798 }
6800 }
6802 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6803 of template arguments. Returns 0 otherwise. */
6805 int
6807 {
6809 }
6811 static void
6813 {
6823 /* We are called both from instantiate_decl, where we've already had a
6824 tinst_level pushed, and instantiate_template, where we haven't.
6825 Compensate. */
6836 else
6845 }
6848 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6849 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6850 documentation for TEMPLATE_ID_EXPR. */
6852 tree
6854 {
6855 tree type;
6863 {
6866 }
6869 {
6871 unknown_type_node,
6873 arglist);
6875 }
6882 }
6884 /* Within the scope of a template class S<T>, the name S gets bound
6885 (in build_self_reference) to a TYPE_DECL for the class, not a
6886 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6887 or one of its enclosing classes, and that type is a template,
6888 return the associated TEMPLATE_DECL. Otherwise, the original
6889 DECL is returned.
6891 Also handle the case when DECL is a TREE_LIST of ambiguous
6892 injected-class-names from different bases. */
6894 tree
6896 {
6900 /* DR 176: A lookup that finds an injected-class-name (10.2
6901 [class.member.lookup]) can result in an ambiguity in certain cases
6902 (for example, if it is found in more than one base class). If all of
6903 the injected-class-names that are found refer to specializations of
6904 the same class template, and if the name is followed by a
6905 template-argument-list, the reference refers to the class template
6906 itself and not a specialization thereof, and is not ambiguous. */
6908 {
6911 {
6917 }
6920 else
6922 }
6928 }
6930 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6931 parameters, find the desired type.
6933 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6935 IN_DECL, if non-NULL, is the template declaration we are trying to
6936 instantiate.
6938 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6939 the class we are looking up.
6941 Issue error and warning messages under control of COMPLAIN.
6943 If the template class is really a local class in a template
6944 function, then the FUNCTION_CONTEXT is the function in which it is
6945 being instantiated.
6947 ??? Note that this function is currently called *twice* for each
6948 template-id: the first time from the parser, while creating the
6949 incomplete type (finish_template_type), and the second type during the
6950 real instantiation (instantiate_template_class). This is surely something
6951 that we want to avoid. It also causes some problems with argument
6952 coercion (see convert_nontype_argument for more information on this). */
6954 static tree
6957 {
6959 tree t;
6962 spec_entry elt;
6963 hashval_t hash;
6966 {
6970 else
6971 {
6978 }
6981 }
6983 {
6986 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6987 an implicit typename for the second A. Deal with it. */
6992 {
6995 }
6996 }
6999 {
7002 }
7006 {
7010 }
7012 /* Issue an error message if we didn't find a template. */
7014 {
7018 }
7021 /* Make sure it's a user visible template, if it was named by
7022 the user. */
7025 {
7027 {
7031 }
7033 }
7038 {
7039 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7040 template arguments */
7042 tree parm;
7043 tree arglist2;
7044 tree outer;
7048 /* Consider an example where a template template parameter declared as
7050 template <class T, class U = std::allocator<T> > class TT
7052 The template parameter level of T and U are one level larger than
7053 of TT. To proper process the default argument of U, say when an
7054 instantiation `TT<int>' is seen, we need to build the full
7055 arguments containing {int} as the innermost level. Outer levels,
7056 available when not appearing as default template argument, can be
7057 obtained from the arguments of the enclosing template.
7059 Suppose that TT is later substituted with std::vector. The above
7060 instantiation is `TT<int, std::allocator<T> >' with TT at
7061 level 1, and T at level 2, while the template arguments at level 1
7062 becomes {std::vector} and the inner level 2 is {int}. */
7068 /* This is an argument of the current template, so we haven't set
7069 DECL_CONTEXT yet. */
7076 complain,
7086 }
7087 else
7088 {
7090 tree gen_tmpl;
7091 tree type_decl;
7099 /* An error occured while building the template TEMPL, and a
7100 diagnostic has most certainly been emitted for that
7101 already. Let's propagate that error. */
7110 {
7111 /* We've been given an incomplete set of template arguments.
7112 For example, given:
7114 template <class T> struct S1 {
7115 template <class U> struct S2 {};
7116 template <class U> struct S2<U*> {};
7117 };
7119 we will be called with an ARGLIST of `U*', but the
7120 TEMPLATE will be `template <class T> template
7121 <class U> struct S1<T>::S2'. We must fill in the missing
7122 arguments. */
7123 arglist
7125 arglist);
7127 }
7129 /* Now we should have enough arguments. */
7132 /* From here on, we're only interested in the most general
7133 template. */
7135 /* Calculate the BOUND_ARGS. These will be the args that are
7136 actually tsubst'd into the definition to create the
7137 instantiation. */
7139 {
7140 /* We have multiple levels of arguments to coerce, at once. */
7150 {
7151 tree a;
7155 complain,
7158 else
7159 /* Outer levels should have already been coerced. */
7162 /* Don't process further if one of the levels fails. */
7164 {
7165 /* Restore the ARGLIST to its full size. */
7168 }
7172 /* We temporarily reduce the length of the ARGLIST so
7173 that coerce_template_parms will see only the arguments
7174 corresponding to the template parameters it is
7175 examining. */
7177 }
7179 /* Restore the ARGLIST to its full size. */
7183 }
7184 else
7185 arglist
7188 gen_tmpl,
7189 complain,
7194 /* We were unable to bind the arguments. */
7197 /* In the scope of a template class, explicit references to the
7198 template class refer to the type of the template, not any
7199 instantiation of it. For example, in:
7201 template <class T> class C { void f(C<T>); }
7203 the `C<T>' is just the same as `C'. Outside of the
7204 class, however, such a reference is an instantiation. */
7208 /* comp_template_args is expensive, check it last. */
7210 arglist))
7213 /* If we already have this specialization, return it. */
7225 /* If the deduced arguments are invalid, then the binding
7226 failed. */
7230 complain))
7237 {
7242 }
7252 /* Create the type. */
7254 {
7256 {
7262 }
7263 else
7264 {
7265 /* We don't want to call start_enum for this type, since
7266 the values for the enumeration constants may involve
7267 template parameters. And, no one should be interested
7268 in the enumeration constants for such a type. */
7271 }
7275 }
7277 {
7278 /* The user referred to a specialization of an alias
7279 template represented by GEN_TMPL.
7281 [temp.alias]/2 says:
7283 When a template-id refers to the specialization of an
7284 alias template, it is equivalent to the associated
7285 type obtained by substitution of its
7286 template-arguments for the template-parameters in the
7287 type-id of the alias template. */
7290 /* Note that the call above (by indirectly calling
7291 register_specialization in tsubst_decl) registers the
7292 TYPE_DECL representing the specialization of the alias
7293 template. So next time someone substitutes ARGLIST for
7294 the template parms into the alias template (GEN_TMPL),
7295 she'll get that TYPE_DECL back. */
7299 }
7301 {
7308 /* A local class. Make sure the decl gets registered properly. */
7313 /* This instantiation is another name for the primary
7314 template type. Set the TYPE_CANONICAL field
7315 appropriately. */
7318 /* Some of the template arguments require structural
7319 equality testing, so this template class requires
7320 structural equality testing. */
7322 }
7323 else
7326 /* If we called start_enum or pushtag above, this information
7327 will already be set up. */
7329 {
7336 }
7337 else
7341 {
7347 {
7350 }
7351 }
7353 /* Let's consider the explicit specialization of a member
7354 of a class template specialization that is implicitely instantiated,
7355 e.g.:
7356 template<class T>
7357 struct S
7358 {
7359 template<class U> struct M {}; //#0
7360 };
7362 template<>
7363 template<>
7364 struct S<int>::M<char> //#1
7365 {
7366 int i;
7367 };
7368 [temp.expl.spec]/4 says this is valid.
7370 In this case, when we write:
7371 S<int>::M<char> m;
7373 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7374 the one of #0.
7376 When we encounter #1, we want to store the partial instantiation
7377 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7379 For all cases other than this "explicit specialization of member of a
7380 class template", we just want to store the most general template into
7381 the CLASSTYPE_TI_TEMPLATE of M.
7383 This case of "explicit specialization of member of a class template"
7384 only happens when:
7385 1/ the enclosing class is an instantiation of, and therefore not
7386 the same as, the context of the most general template, and
7387 2/ we aren't looking at the partial instantiation itself, i.e.
7388 the innermost arguments are not the same as the innermost parms of
7389 the most general template.
7391 So it's only when 1/ and 2/ happens that we want to use the partial
7392 instantiation of the member template in lieu of its most general
7393 template. */
7397 /* the enclosing class must be an instantiation... */
7400 {
7401 tree partial_inst_args;
7404 partial_inst_args =
7410 use_partial_inst_tmpl =
7411 /*...and we must not be looking at the partial instantiation
7412 itself. */
7414 partial_inst_args);
7415 }
7418 /* This case is easy; there are no member templates involved. */
7420 else
7421 {
7422 /* This is a full instantiation of a member template. Find
7423 the partial instantiation of which this is an instance. */
7425 /* Temporarily reduce by one the number of levels in the ARGLIST
7426 so as to avoid comparing the last set of arguments. */
7430 /* FOUND is either a proper class type, or an alias
7431 template specialization. In the later case, it's a
7432 TYPE_DECL, resulting from the substituting of arguments
7433 for parameters in the TYPE_DECL of the alias template
7434 done earlier. So be careful while getting the template
7435 of FOUND. */
7439 }
7450 /* Note this use of the partial instantiation so we can check it
7451 later in maybe_process_partial_specialization. */
7457 /* Now that the type has been registered on the instantiations
7458 list, we set up the enumerators. Because the enumeration
7459 constants may involve the enumeration type itself, we make
7460 sure to register the type first, and then create the
7461 constants. That way, doing tsubst_expr for the enumeration
7462 constants won't result in recursive calls here; we'll find
7463 the instantiation and exit above. */
7467 /* If the type makes use of template parameters, the
7468 code that generates debugging information will crash. */
7471 /* Possibly limit visibility based on template args. */
7476 }
7477 }
7479 /* Wrapper for lookup_template_class_1. */
7481 tree
7484 {
7485 tree ret;
7491 }
7492 \f
7493 struct pair_fn_data
7494 {
7495 tree_fn_t fn;
7497 /* True when we should also visit template parameters that occur in
7498 non-deduced contexts. */
7501 };
7503 /* Called from for_each_template_parm via walk_tree. */
7505 static tree
7507 {
7520 {
7524 /* Fall through. */
7547 /* Since we're not going to walk subtrees, we have to do this
7548 explicitly here. */
7552 /* Fall through. */
7555 /* Check the return type. */
7560 /* Check the parameter types. Since default arguments are not
7561 instantiated until they are needed, the TYPE_ARG_TYPES may
7562 contain expressions that involve template parameters. But,
7563 no-one should be looking at them yet. And, once they're
7564 instantiated, they don't contain template parameters, so
7565 there's no point in looking at them then, either. */
7566 {
7567 tree parm;
7574 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7575 want walk_tree walking into them itself. */
7577 }
7595 /* Fall through. */
7611 /* Record template parameters such as `T' inside `TT<T>'. */
7615 /* Fall through. */
7627 /* A template template parameter is encountered. */
7633 /* Already substituted template template parameter */
7656 /* If there's no type, then this thing must be some expression
7657 involving template parameters. */
7679 }
7681 /* We didn't find any template parameters we liked. */
7683 }
7685 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7686 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7687 call FN with the parameter and the DATA.
7688 If FN returns nonzero, the iteration is terminated, and
7689 for_each_template_parm returns 1. Otherwise, the iteration
7690 continues. If FN never returns a nonzero value, the value
7691 returned by for_each_template_parm is 0. If FN is NULL, it is
7692 considered to be the function which always returns 1.
7694 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7695 parameters that occur in non-deduced contexts. When false, only
7696 visits those template parameters that can be deduced. */
7698 static int
7702 {
7706 /* Set up. */
7711 /* Walk the tree. (Conceptually, we would like to walk without
7712 duplicates, but for_each_template_parm_r recursively calls
7713 for_each_template_parm, so we would need to reorganize a fair
7714 bit to use walk_tree_without_duplicates, so we keep our own
7715 visited list.) */
7718 else
7721 for_each_template_parm_r,
7725 /* Clean up. */
7727 {
7730 }
7733 }
7735 /* Returns true if T depends on any template parameter. */
7737 int
7739 {
7766 else
7767 {
7770 }
7775 }
7777 /* Returns true iff current_function_decl is an incompletely instantiated
7778 template. Useful instead of processing_template_decl because the latter
7779 is set to 0 during fold_non_dependent_expr. */
7781 bool
7783 {
7792 }
7794 /* Returns true if T depends on any template parameter with level LEVEL. */
7796 int
7798 {
7801 }
7803 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7804 ill-formed translation unit, i.e. a variable or function that isn't
7805 usable in a constant expression. */
7809 {
7813 }
7815 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7816 neglectable and instantiated from within an erroneous instantiation. */
7818 static bool
7820 {
7831 }
7839 /* We're starting to instantiate D; record the template instantiation context
7840 for diagnostics and to restore it later. */
7842 int
7844 {
7848 {
7854 else
7862 }
7864 /* If the current instantiation caused problems, don't let it instantiate
7865 anything else. Do allow deduction substitution and decls usable in
7866 constant expressions. */
7883 }
7885 /* We're done instantiating this template; return to the instantiation
7886 context. */
7888 void
7890 {
7891 /* Restore the filename and line number stashed away when we started
7892 this instantiation. */
7896 }
7898 /* We're instantiating a deferred template; restore the template
7899 instantiation context in which the instantiation was requested, which
7900 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7902 static tree
7904 {
7916 }
7918 /* Returns the TINST_LEVEL which gives the original instantiation
7919 context. */
7923 {
7929 }
7931 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7932 vector of template arguments, as for tsubst.
7934 Returns an appropriate tsubst'd friend declaration. */
7936 static tree
7938 {
7939 tree new_friend;
7944 /* This was a friend declared with an explicit template
7945 argument list, e.g.:
7947 friend void f<>(T);
7949 to indicate that f was a template instantiation, not a new
7950 function declaration. Now, we have to figure out what
7951 instantiation of what template. */
7952 {
7954 tree new_args;
7955 tree tmpl;
7958 /* Friend functions are looked up in the containing namespace scope.
7959 We must enter that scope, to avoid finding member functions of the
7960 current class with same name. */
7975 tsk_none);
7977 }
7981 /* The NEW_FRIEND will look like an instantiation, to the
7982 compiler, but is not an instantiation from the point of view of
7983 the language. For example, we might have had:
7985 template <class T> struct S {
7986 template <class U> friend void f(T, U);
7987 };
7989 Then, in S<int>, template <class U> void f(int, U) is not an
7990 instantiation of anything. */
7996 {
8000 }
8002 /* The mangled name for the NEW_FRIEND is incorrect. The function
8003 is not a template instantiation and should not be mangled like
8004 one. Therefore, we forget the mangling here; we'll recompute it
8005 later if we need it. */
8007 {
8010 }
8013 {
8014 tree old_decl;
8015 tree new_friend_template_info;
8016 tree new_friend_result_template_info;
8017 tree ns;
8020 /* We must save some information from NEW_FRIEND before calling
8021 duplicate decls since that function will free NEW_FRIEND if
8022 possible. */
8024 new_friend_is_defn =
8029 {
8030 /* This declaration is a `primary' template. */
8033 new_friend_result_template_info
8035 }
8036 else
8039 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8043 /* Inside pushdecl_namespace_level, we will push into the
8044 current namespace. However, the friend function should go
8045 into the namespace of the template. */
8055 {
8056 /* This new friend declaration matched an existing
8057 declaration. For example, given:
8059 template <class T> void f(T);
8060 template <class U> class C {
8061 template <class T> friend void f(T) {}
8062 };
8064 the friend declaration actually provides the definition
8065 of `f', once C has been instantiated for some type. So,
8066 old_decl will be the out-of-class template declaration,
8067 while new_friend is the in-class definition.
8069 But, if `f' was called before this point, the
8070 instantiation of `f' will have DECL_TI_ARGS corresponding
8071 to `T' but not to `U', references to which might appear
8072 in the definition of `f'. Previously, the most general
8073 template for an instantiation of `f' was the out-of-class
8074 version; now it is the in-class version. Therefore, we
8075 run through all specialization of `f', adding to their
8076 DECL_TI_ARGS appropriately. In particular, they need a
8077 new set of outer arguments, corresponding to the
8078 arguments for this class instantiation.
8080 The same situation can arise with something like this:
8082 friend void f(int);
8083 template <class T> class C {
8084 friend void f(T) {}
8085 };
8087 when `C<int>' is instantiated. Now, `f(int)' is defined
8088 in the class. */
8091 /* On the other hand, if the in-class declaration does
8092 *not* provide a definition, then we don't want to alter
8093 existing definitions. We can just leave everything
8094 alone. */
8095 ;
8096 else
8097 {
8101 /* Overwrite whatever template info was there before, if
8102 any, with the new template information pertaining to
8103 the declaration. */
8107 {
8108 /* We should have called reregister_specialization in
8109 duplicate_decls. */
8114 /* Instantiate it if the global has already been used. */
8118 }
8119 else
8120 {
8121 tree t;
8123 /* Indicate that the old function template is a partial
8124 instantiation. */
8132 /* Reassign any specializations already in the hash table
8133 to the new more general template, and add the
8134 additional template args. */
8138 {
8140 spec_entry elt;
8152 register_specialization
8155 }
8157 }
8158 }
8160 /* The information from NEW_FRIEND has been merged into OLD_DECL
8161 by duplicate_decls. */
8163 }
8164 }
8165 else
8166 {
8170 /* In the code
8171 template <class T> class C {
8172 template <class U> friend void C1<U>::f (); // case 1
8173 friend void C2<T>::f (); // case 2
8174 };
8175 we only need to make sure CONTEXT is a complete type for
8176 case 2. To distinguish between the two cases, we note that
8177 CONTEXT of case 1 remains dependent type after tsubst while
8178 this isn't true for case 2. */
8188 {
8189 /* Check to see that the declaration is really present, and,
8190 possibly obtain an improved declaration. */
8196 }
8197 }
8200 }
8202 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8203 template arguments, as for tsubst.
8205 Returns an appropriate tsubst'd friend type or error_mark_node on
8206 failure. */
8208 static tree
8210 {
8211 tree friend_type;
8212 tree tmpl;
8213 tree context;
8216 {
8219 }
8224 {
8227 else
8229 }
8231 /* Look for a class template declaration. We look for hidden names
8232 because two friend declarations of the same template are the
8233 same. For example, in:
8235 struct A {
8236 template <typename> friend class F;
8237 };
8238 template <typename> struct B {
8239 template <typename> friend class F;
8240 };
8242 both F templates are the same. */
8246 /* But, if we don't find one, it might be because we're in a
8247 situation like this:
8249 template <class T>
8250 struct S {
8251 template <class U>
8252 friend struct S;
8253 };
8255 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8256 for `S<int>', not the TEMPLATE_DECL. */
8258 {
8261 }
8264 {
8265 /* The friend template has already been declared. Just
8266 check to see that the declarations match, and install any new
8267 default parameters. We must tsubst the default parameters,
8268 of course. We only need the innermost template parameters
8269 because that is all that redeclare_class_template will look
8270 at. */
8273 {
8274 tree parms;
8275 location_t saved_input_location;
8284 }
8287 }
8288 else
8289 {
8290 /* The friend template has not already been declared. In this
8291 case, the instantiation of the template class will cause the
8292 injection of this template into the global scope. */
8297 /* The new TMPL is not an instantiation of anything, so we
8298 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8299 the new type because that is supposed to be the corresponding
8300 template decl, i.e., TMPL. */
8307 /* Inject this template into the global scope. */
8309 }
8312 {
8315 else
8317 }
8320 }
8322 /* Returns zero if TYPE cannot be completed later due to circularity.
8323 Otherwise returns one. */
8325 static int
8327 {
8337 else
8339 }
8341 /* Apply any attributes which had to be deferred until instantiation
8342 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8343 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8345 static void
8348 {
8350 tree t;
8355 {
8359 }
8362 {
8366 }
8367 else
8371 {
8376 {
8379 {
8382 /* If the first attribute argument is an identifier, don't
8383 pass it through tsubst. Attributes like mode, format,
8384 cleanup and several target specific attributes expect it
8385 unmodified. */
8391 {
8392 tree chain
8394 in_decl,
8399 chain);
8400 }
8401 else
8407 }
8408 else
8410 }
8413 }
8414 }
8416 /* Perform (or defer) access check for typedefs that were referenced
8417 from within the template TMPL code.
8418 This is a subroutine of instantiate_decl and instantiate_class_template.
8419 TMPL is the template to consider and TARGS is the list of arguments of
8420 that template. */
8422 static void
8424 {
8425 location_t saved_location;
8438 {
8450 /* Make access check error messages point to the location
8451 of the use of the typedef. */
8455 tf_warning_or_error);
8456 }
8458 }
8460 static tree
8462 {
8464 tree typedecl;
8465 tree pbinfo;
8466 tree base_list;
8468 tree fn_context;
8477 /* Figure out which template is being instantiated. */
8481 /* Determine what specialization of the original template to
8482 instantiate. */
8485 {
8488 }
8490 {
8491 /* This TYPE is actually an instantiation of a partial
8492 specialization. We replace the innermost set of ARGS with
8493 the arguments appropriate for substitution. For example,
8494 given:
8496 template <class T> struct S {};
8497 template <class T> struct S<T*> {};
8499 and supposing that we are instantiating S<int*>, ARGS will
8500 presently be {int*} -- but we need {int}. */
8503 }
8504 else
8505 {
8508 }
8510 /* If the template we're instantiating is incomplete, then clearly
8511 there's nothing we can do. */
8515 /* If we've recursively instantiated too many templates, stop. */
8519 /* Now we're really doing the instantiation. Mark the type as in
8520 the process of being defined. */
8523 /* We may be in the middle of deferred access check. Disable
8524 it now. */
8530 /* Use #pragma pack from the template context. */
8536 /* Set the input location to the most specialized template definition.
8537 This is needed if tsubsting causes an error. */
8549 {
8552 /* Adjust visibility for template arguments. */
8554 }
8559 /* We should never instantiate a nested class before its enclosing
8560 class; we need to look up the nested class by name before we can
8561 instantiate it, and that lookup should instantiate the enclosing
8562 class. */
8568 {
8569 tree pbase_binfo;
8570 tree pushed_scope;
8573 /* We must enter the scope containing the type, as that is where
8574 the accessibility of types named in dependent bases are
8575 looked up from. */
8578 /* Substitute into each of the bases to determine the actual
8579 basetypes. */
8581 {
8582 tree base;
8588 {
8589 expanded_bases =
8596 }
8599 {
8601 /* Extract the already-expanded base class. */
8603 else
8604 /* Substitute to figure out the base class. */
8606 NULL_TREE);
8614 }
8615 }
8617 /* The list is now in reverse order; correct that. */
8622 }
8623 /* Now call xref_basetypes to set up all the base-class
8624 information. */
8632 /* Now that our base classes are set up, enter the scope of the
8633 class, so that name lookups into base classes, etc. will work
8634 correctly. This is precisely analogous to what we do in
8635 begin_class_definition when defining an ordinary non-template
8636 class, except we also need to push the enclosing classes. */
8639 /* Now members are processed in the order of declaration. */
8642 {
8646 {
8648 {
8649 /* Build new CLASSTYPE_NESTED_UTDS. */
8651 tree newtag;
8657 /* If the member is a class template, then -- even after
8658 substitution -- there may be dependent types in the
8659 template argument list for the class. We increment
8660 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8661 that function will assume that no types are dependent
8662 when outside of a template. */
8672 {
8676 /* Unfortunately, lookup_template_class sets
8677 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8678 instantiation (i.e., for the type of a member
8679 template class nested within a template class.)
8680 This behavior is required for
8681 maybe_process_partial_specialization to work
8682 correctly, but is not accurate in this case;
8683 the TAG is not an instantiation of anything.
8684 (The corresponding TEMPLATE_DECL is an
8685 instantiation, but the TYPE is not.) */
8688 /* Now, we call pushtag to put this NEWTAG into the scope of
8689 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8690 pushtag calling push_template_decl. We don't have to do
8691 this for enums because it will already have been done in
8692 tsubst_enum. */
8696 }
8697 }
8700 {
8701 /* Build new TYPE_METHODS. */
8702 tree r;
8711 /* Instantiate members marked with attribute used. */
8714 }
8715 else
8716 {
8717 /* Build new TYPE_FIELDS. */
8719 {
8720 tree condition;
8723 condition =
8733 }
8735 {
8736 tree r;
8738 /* The file and line for this declaration, to
8739 assist in error message reporting. Since we
8740 called push_tinst_level above, we don't need to
8741 restore these. */
8750 {
8751 /* In [temp.inst]:
8753 [t]he initialization (and any associated
8754 side-effects) of a static data member does
8755 not occur unless the static data member is
8756 itself used in a way that requires the
8757 definition of the static data member to
8758 exist.
8760 Therefore, we do not substitute into the
8761 initialized for the static data member here. */
8762 finish_static_data_member_decl
8768 /* Instantiate members marked with attribute used. */
8771 }
8773 {
8774 /* Determine whether R has a valid type and can be
8775 completed later. If R is invalid, then it is
8776 replaced by error_mark_node so that it will not be
8777 added to TYPE_FIELDS. */
8783 {
8786 }
8787 }
8789 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8790 such a thing will already have been added to the field
8791 list by tsubst_enum in finish_member_declaration in the
8792 CLASSTYPE_NESTED_UTDS case above. */
8796 {
8799 }
8800 }
8801 }
8802 }
8803 else
8804 {
8807 {
8808 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8814 {
8815 /* template <class T> friend class C; */
8818 }
8820 {
8821 /* template <class T> friend class C::D; */
8827 }
8830 {
8831 /* This could be either
8833 friend class T::C;
8835 when dependent_type_p is false or
8837 template <class U> friend class T::C;
8839 otherwise. */
8842 /* Bump processing_template_decl for correct
8843 dependent_type_p calculation. */
8848 }
8851 {
8852 /* friend class C;
8854 where C hasn't been declared yet. Let's lookup name
8855 from namespace scope directly, bypassing any name that
8856 come from dependent base class. */
8859 /* The call to xref_tag_from_type does injection for friend
8860 classes. */
8862 friend_type =
8866 }
8868 /* friend class C<T>; */
8871 /* Otherwise it's
8873 friend class C;
8875 where C is already declared or
8877 friend class C<int>;
8879 We don't have to do anything in these cases. */
8882 /* Trick make_friend_class into realizing that the friend
8883 we're adding is a template, not an ordinary class. It's
8884 important that we use make_friend_class since it will
8885 perform some error-checking and output cross-reference
8886 information. */
8894 }
8895 else
8896 {
8897 /* Build new DECL_FRIENDLIST. */
8898 tree r;
8900 /* The file and line for this declaration, to
8901 assist in error message reporting. Since we
8902 called push_tinst_level above, we don't need to
8903 restore these. */
8907 {
8910 }
8915 {
8918 }
8919 }
8920 }
8921 }
8924 {
8927 {
8936 }
8937 else
8939 }
8941 /* Set the file and line number information to whatever is given for
8942 the class itself. This puts error messages involving generated
8943 implicit functions at a predictable point, and the same point
8944 that would be used for non-template classes. */
8951 /* We don't instantiate default arguments for member functions. 14.7.1:
8953 The implicit instantiation of a class template specialization causes
8954 the implicit instantiation of the declarations, but not of the
8955 definitions or default arguments, of the class member functions,
8956 member classes, static data members and member templates.... */
8958 /* Some typedefs referenced from within the template code need to be access
8959 checked at template instantiation time, i.e now. These types were
8960 added to the template at parsing time. Let's get those and perform
8961 the access checks then. */
8971 /* The vtable for a template class can be emitted in any translation
8972 unit in which the class is instantiated. When there is no key
8973 method, however, finish_struct_1 will already have added TYPE to
8974 the keyed_classes list. */
8979 }
8981 /* Wrapper for instantiate_class_template_1. */
8983 tree
8985 {
8986 tree ret;
8991 }
8993 static tree
8995 {
8996 tree r;
9002 else
9003 {
9010 /* Preserve the raw-reference nature of T. */
9014 }
9016 }
9018 /* Given a function parameter pack TMPL_PARM and some function parameters
9019 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9020 and set *SPEC_P to point at the next point in the list. */
9022 static tree
9024 {
9025 /* Collect all of the extra "packed" parameters into an
9026 argument pack. */
9027 tree parmvec;
9028 tree parmtypevec;
9039 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9044 {
9047 }
9049 /* Build the argument packs. */
9056 }
9058 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9059 NONTYPE_ARGUMENT_PACK. */
9061 static tree
9063 {
9065 }
9067 /* Substitute ARGS into T, which is an pack expansion
9068 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9069 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9070 (if only a partial substitution could be performed) or
9071 ERROR_MARK_NODE if there was an error. */
9072 tree
9074 tree in_decl)
9075 {
9076 tree pattern;
9082 tree result;
9090 /* Add in any args remembered from an earlier partial instantiation. */
9095 /* Determine the argument packs that will instantiate the parameter
9096 packs used in the expansion expression. While we're at it,
9097 compute the number of arguments to be expanded and make sure it
9098 is consistent. */
9101 {
9108 {
9112 else
9115 }
9117 {
9120 else
9121 {
9122 /* We can't rely on local_specializations for a parameter
9123 name used later in a function declaration (such as in a
9124 late-specified return type). Even if it exists, it might
9125 have the wrong value for a recursive call. Just make a
9126 dummy decl, since it's only used for its type. */
9129 /* Partial instantiation of the parm_pack, we can't build
9130 up an argument pack yet. */
9132 else
9135 }
9136 }
9137 else
9138 {
9144 }
9151 /* This can only happen if we forget to expand an argument
9152 pack somewhere else. Just return an error, silently. */
9153 {
9157 }
9160 /* The argument pack that the parameter maps to is just an
9161 expansion of the parameter itself, such as one would find
9162 in the implicit typedef of a class inside the class itself.
9163 Consider this parameter "unsubstituted", so that we will
9164 maintain the outer pack expansion. */
9168 {
9172 /* Don't bother trying to do a partial substitution with
9173 incomplete packs; we'll try again after deduction. */
9180 {
9186 pattern);
9187 else
9190 pattern);
9192 }
9198 else
9201 /* Keep track of the parameter packs and their corresponding
9202 argument packs. */
9205 }
9206 else
9207 {
9208 /* We can't substitute for this parameter pack. We use a flag as
9209 well as the missing_level counter because function parameter
9210 packs don't have a level. */
9214 }
9215 }
9217 /* We cannot expand this expansion expression, because we don't have
9218 all of the argument packs we need. */
9220 {
9222 {
9223 /* We got some full packs, but we can't substitute them in until we
9224 have values for all the packs. So remember these until then. */
9225 tree save_args;
9229 /* The call to add_to_template_args above assumes no overlap
9230 between saved args and new args, so prune away any fake
9231 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9233 {
9239 }
9240 else
9244 }
9245 else
9246 {
9247 /* There were no real arguments, we're just replacing a parameter
9248 pack with another version of itself. Substitute into the
9249 pattern and return a PACK_EXPANSION_*. The caller will need to
9250 deal with that. */
9254 else
9257 }
9259 }
9261 /* We could not find any argument packs that work. */
9266 {
9267 /* We're in a late-specified return type, so create our own local
9268 specializations map; the current map is either NULL or (in the
9269 case of recursive unification) might have bindings that we don't
9270 want to use or alter. */
9273 }
9275 /* For each argument in each argument pack, substitute into the
9276 pattern. */
9279 {
9280 /* For parameter pack, change the substitution of the parameter
9281 pack to the ith argument in its argument pack, then expand
9282 the pattern. */
9284 {
9286 tree arg;
9288 /* Select the Ith argument from the pack. */
9290 {
9292 {
9297 }
9298 else
9300 }
9301 else
9302 {
9307 {
9310 /* Update the corresponding argument. */
9312 }
9313 else
9314 /* Re-use the ARGUMENT_PACK_SELECT. */
9316 }
9318 }
9320 /* Substitute into the PATTERN with the altered arguments. */
9325 else
9329 {
9332 }
9333 }
9335 /* Update ARGS to restore the substitution from parameter packs to
9336 their argument packs. */
9338 {
9343 else
9344 {
9348 /* Update the corresponding argument. */
9352 else
9354 }
9355 }
9358 {
9361 }
9364 }
9366 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9367 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9368 parameter packs; all parms generated from a function parameter pack will
9369 have the same DECL_PARM_INDEX. */
9371 tree
9373 {
9375 tree patparm;
9378 {
9384 }
9385 else
9386 {
9391 }
9394 }
9396 /* Substitute ARGS into the vector or list of template arguments T. */
9398 static tree
9400 {
9412 {
9414 tree new_arg;
9419 {
9420 /* Substitute into an expansion expression. */
9424 /* Add to the expanded length adjustment the number of
9425 expanded arguments. We subtract one from this
9426 measurement, because the argument pack expression
9427 itself is already counted as 1 in
9428 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9429 the argument pack is empty. */
9431 }
9433 {
9434 /* Substitute into each of the arguments. */
9440 new_arg,
9454 }
9455 }
9456 else
9465 }
9470 /* Make space for the expanded arguments coming from template
9471 argument packs. */
9473 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9474 arguments for a member template.
9475 In that case each TREE_VEC in ORIG_T represents a level of template
9476 arguments, and ORIG_T won't carry any non defaulted argument count.
9477 It will rather be the nested TREE_VECs that will carry one.
9478 In other words, ORIG_T carries a non defaulted argument count only
9479 if it doesn't contain any nested TREE_VEC. */
9481 {
9485 }
9487 {
9491 {
9494 /* Now expand the template argument pack "in place". */
9497 }
9498 else
9499 {
9501 out++;
9502 }
9503 }
9506 }
9508 /* Return the result of substituting ARGS into the template parameters
9509 given by PARMS. If there are m levels of ARGS and m + n levels of
9510 PARMS, then the result will contain n levels of PARMS. For
9511 example, if PARMS is `template <class T> template <class U>
9512 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9513 result will be `template <int*, double, class V>'. */
9515 static tree
9517 {
9521 /* When substituting into a template, we must set
9522 PROCESSING_TEMPLATE_DECL as the template parameters may be
9523 dependent if they are based on one-another, and the dependency
9524 predicates are short-circuit outside of templates. */
9531 {
9532 tree new_vec =
9537 {
9538 tree tuple;
9550 }
9556 }
9561 }
9563 /* Return the result of substituting ARGS into one template parameter
9564 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9565 parameter and which TREE_PURPOSE is the default argument of the
9566 template parameter. */
9568 static tree
9570 {
9591 }
9593 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9594 type T. If T is not an aggregate or enumeration type, it is
9595 handled as if by tsubst. IN_DECL is as for tsubst. If
9596 ENTERING_SCOPE is nonzero, T is the context for a template which
9597 we are presently tsubst'ing. Return the substituted value. */
9599 static tree
9601 tree args,
9602 tsubst_flags_t complain,
9603 tree in_decl,
9605 {
9610 {
9615 /* Else fall through. */
9619 {
9620 tree argvec;
9621 tree context;
9622 tree r;
9626 /* In "sizeof(X<I>)" we need to evaluate "I". */
9632 /* First, determine the context for the type we are looking
9633 up. */
9636 {
9639 /* If context is a nested class inside a class template,
9640 it may still need to be instantiated (c++/33959). */
9642 }
9644 /* Then, figure out what arguments are appropriate for the
9645 type we are trying to find. For example, given:
9647 template <class T> struct S;
9648 template <class T, class U> void f(T, U) { S<U> su; }
9650 and supposing that we are instantiating f<int, double>,
9651 then our ARGS will be {int, double}, but, when looking up
9652 S we only want {double}. */
9657 else
9658 {
9662 }
9668 }
9669 else
9670 /* This is not a template type, so there's nothing to do. */
9675 }
9676 }
9678 /* Substitute into the default argument ARG (a default argument for
9679 FN), which has the indicated TYPE. */
9681 tree
9683 {
9688 /* This can happen in invalid code. */
9692 /* This default argument came from a template. Instantiate the
9693 default argument here, not in tsubst. In the case of
9694 something like:
9696 template <class T>
9697 struct S {
9698 static T t();
9699 void f(T = t());
9700 };
9702 we must be careful to do name lookup in the scope of S<T>,
9703 rather than in the current class. */
9705 /* The "this" pointer is not valid in a default argument. */
9707 {
9712 }
9715 /* The default argument expression may cause implicitly defined
9716 member functions to be synthesized, which will result in garbage
9717 collection. We must treat this situation as if we were within
9718 the body of function so as to avoid collecting live data on the
9719 stack. */
9727 /* Restore the "this" pointer. */
9729 {
9732 }
9738 /* Make sure the default argument is reasonable. */
9744 }
9746 /* Substitute into all the default arguments for FN. */
9748 static void
9750 {
9751 tree arg;
9752 tree tmpl_args;
9756 /* If this function is not yet instantiated, we certainly don't need
9757 its default arguments. */
9760 /* Don't do this again for clones. */
9765 arg;
9771 }
9773 /* Substitute the ARGS into the T, which is a _DECL. Return the
9774 result of the substitution. Issue error and warning messages under
9775 control of COMPLAIN. */
9777 static tree
9779 {
9780 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9781 location_t saved_loc;
9786 /* Set the filename and linenumber to improve error-reporting. */
9791 {
9793 {
9794 /* We can get here when processing a member function template,
9795 member class template, or template template parameter. */
9797 tree spec;
9798 tree tmpl_args;
9799 tree full_args;
9802 {
9803 /* Template template parameter is treated here. */
9816 complain);
9819 }
9821 /* We might already have an instance of this template.
9822 The ARGS are for the surrounding class type, so the
9823 full args contain the tsubst'd args for the context,
9824 plus the innermost args from the template decl. */
9828 /* Because this is a template, the arguments will still be
9829 dependent, even after substitution. If
9830 PROCESSING_TEMPLATE_DECL is not set, the dependency
9831 predicates will short-circuit. */
9839 /* If this is a default template template argument,
9840 tsubst might not have changed anything. */
9847 {
9850 }
9852 /* Make a new template decl. It will be similar to the
9853 original, but will record the current template arguments.
9854 We also create a new function declaration, which is just
9855 like the old one, but points to this new template, rather
9856 than the old one. */
9865 {
9866 tree new_type;
9878 }
9879 else
9880 {
9881 tree new_decl;
9893 }
9899 /* The template parameters for this new template are all the
9900 template parameters for the old template, except the
9901 outermost level of parameters. */
9904 complain);
9910 /* Record this non-type partial instantiation. */
9914 }
9918 {
9919 tree ctx;
9922 tree gen_tmpl;
9923 tree type;
9928 /* Nobody should be tsubst'ing into non-template functions. */
9932 {
9933 tree spec;
9936 /* If T is not dependent, just return it. We have to
9937 increment PROCESSING_TEMPLATE_DECL because
9938 value_dependent_expression_p assumes that nothing is
9939 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9946 /* Calculate the most general template of which R is a
9947 specialization, and the complete set of arguments used to
9948 specialize R. */
9951 (DECL_TEMPLATE_RESULT
9957 /* Check to see if we already have this specialization. */
9962 {
9965 }
9967 /* We can see more levels of arguments than parameters if
9968 there was a specialization of a member template, like
9969 this:
9971 template <class T> struct S { template <class U> void f(); }
9972 template <> template <class U> void S<int>::f(U);
9974 Here, we'll be substituting into the specialization,
9975 because that's where we can find the code we actually
9976 want to generate, but we'll have enough arguments for
9977 the most general template.
9979 We also deal with the peculiar case:
9981 template <class T> struct S {
9982 template <class U> friend void f();
9983 };
9984 template <class U> void f() {}
9985 template S<int>;
9986 template void f<double>();
9988 Here, the ARGS for the instantiation of will be {int,
9989 double}. But, we only need as many ARGS as there are
9990 levels of template parameters in CODE_PATTERN. We are
9991 careful not to get fooled into reducing the ARGS in
9992 situations like:
9994 template <class T> struct S { template <class U> void f(U); }
9995 template <class T> template <> void S<T>::f(int) {}
9997 which we can spot because the pattern will be a
9998 specialization in this case. */
10000 parms_depth =
10005 }
10006 else
10007 {
10008 /* This special case arises when we have something like this:
10010 template <class T> struct S {
10011 friend void f<int>(int, double);
10012 };
10014 Here, the DECL_TI_TEMPLATE for the friend declaration
10015 will be an IDENTIFIER_NODE. We are being called from
10016 tsubst_friend_function, and we want only to create a
10017 new decl (R) with appropriate types so that we can call
10018 determine_specialization. */
10020 }
10023 {
10026 else
10030 }
10031 else
10032 {
10035 }
10040 /* If we hit excessive deduction depth, the type is bogus even if
10041 it isn't error_mark_node, so don't build a decl. */
10045 /* We do NOT check for matching decls pushed separately at this
10046 point, as they may not represent instantiations of this
10047 template, and in any case are considered separate under the
10048 discrete model. */
10052 /* Clear out the mangled name and RTL for the instantiation. */
10055 /* Leave DECL_INITIAL set on deleted instantiations. */
10061 /* Type-conversion operator. Reconstruct the name, in
10062 case it's the name of one of the template's parameters. */
10072 /* If this is an instantiation of a function with internal
10073 linkage, we already know what object file linkage will be
10074 assigned to the instantiation. */
10083 /* We'll re-clone as appropriate in instantiate_template. */
10086 /* If we aren't complaining now, return on error before we register
10087 the specialization so that we'll complain eventually. */
10093 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10094 this in the special friend case mentioned above where
10095 GEN_TMPL is NULL. */
10097 {
10103 /* We're not supposed to instantiate default arguments
10104 until they are called, for a template. But, for a
10105 declaration like:
10107 template <class T> void f ()
10108 { extern void g(int i = T()); }
10110 we should do the substitution when the template is
10111 instantiated. We handle the member function case in
10112 instantiate_class_template since the default arguments
10113 might refer to other members of the class. */
10118 }
10119 else
10122 /* Copy the list of befriending classes. */
10126 {
10130 in_decl);
10131 }
10134 {
10138 /* If this is an instantiation of a member template, clone it.
10139 If it isn't, that'll be handled by
10140 clone_constructors_and_destructors. */
10143 }
10154 /* Possibly limit visibility based on template args. */
10157 {
10161 }
10169 }
10173 {
10181 {
10182 /* If there is a local specialization that isn't a
10183 parameter pack, it means that we're doing a "simple"
10184 substitution from inside tsubst_pack_expansion. Just
10185 return the local specialization (which will be a single
10186 parm). */
10193 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10194 the parameters in this function parameter pack. */
10198 {
10201 /* Zero-length parameter packs are boring. Just substitute
10202 into the chain. */
10206 }
10207 else
10208 {
10209 /* All we did was update the type. Make a note of that. */
10212 }
10213 }
10215 /* Loop through all of the parameter's we'll build. When T is
10216 a function parameter pack, LEN is the number of expanded
10217 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10220 {
10227 /* We're on the Ith parameter of the function parameter
10228 pack. */
10229 {
10230 /* An argument of a function parameter pack is not a parameter
10231 pack. */
10234 /* Get the Ith type. */
10238 /* Rename the parameter to include the index. */
10241 }
10243 /* We're dealing with a normal parameter. */
10251 {
10254 else
10257 }
10267 /* Keep track of the first new parameter we
10268 generate. That's what will be returned to the
10269 caller. */
10273 /* Build a proper chain of parameters when substituting
10274 into a function parameter pack. */
10277 }
10279 /* If cp_unevaluated_operand is set, we're just looking for a
10280 single dummy parameter, so don't keep going. */
10285 /* FIRST_R contains the start of the chain we've built. */
10287 }
10291 {
10292 tree type;
10302 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10303 non-bit-fields DECL_INITIAL is a non-static data member
10304 initializer, which gets deferred instantiation. */
10310 {
10311 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10312 NSDMI in perform_member_init. Still set DECL_INITIAL
10313 so that we know there is one. */
10318 }
10319 /* We don't have to set DECL_CONTEXT here; it is set by
10320 finish_member_declaration. */
10327 }
10331 /* We reach here only for member using decls. We also need to check
10332 uses_template_parms because DECL_DEPENDENT_P is not set for a
10333 using-declaration that designates a member of the current
10334 instantiation (c++/53549). */
10337 {
10338 r = do_class_using_decl
10343 else
10344 {
10347 }
10348 }
10349 else
10350 {
10353 }
10358 {
10361 tree spec;
10363 tree ctx;
10369 {
10370 /* If this is the canonical decl, we don't have to
10371 mess with instantiations, and often we can't (for
10372 typename, template type parms and such). Note that
10373 TYPE_NAME is not correct for the above test if
10374 we've copied the type for a typedef. */
10380 }
10382 /* Check to see if we already have the specialization we
10383 need. */
10386 {
10387 /* T is a static data member or namespace-scope entity.
10388 We have to substitute into namespace-scope variables
10389 (even though such entities are never templates) because
10390 of cases like:
10392 template <class T> void f() { extern T t; }
10394 where the entity referenced is not known until
10395 instantiation time. */
10399 {
10401 complain,
10403 /* If CTX is unchanged, then T is in fact the
10404 specialization we want. That situation occurs when
10405 referencing a static data member within in its own
10406 class. We can use pointer equality, rather than
10407 same_type_p, because DECL_CONTEXT is always
10408 canonical... */
10411 /* ... unless T is a member template; in which
10412 case our caller can be willing to create a
10413 specialization of that template represented
10414 by T. */
10418 }
10421 {
10429 }
10430 }
10431 else
10432 {
10433 /* A local variable. */
10435 /* Subsequent calls to pushdecl will fill this in. */
10438 }
10439 /* If we already have the specialization we need, there is
10440 nothing more to do. */
10442 {
10445 }
10447 /* Create a new node for the specialization we need. */
10450 {
10453 else
10460 }
10462 {
10463 /* Even if the original location is out of scope, the
10464 newly substituted one is not. */
10471 {
10472 /* It may seem that this case cannot occur, since:
10474 typedef void f();
10475 void g() { f x; }
10477 declares a function, not a variable. However:
10479 typedef void f();
10480 template <typename T> void g() { T t; }
10481 template void g<f>();
10483 is an attempt to declare a variable with function
10484 type. */
10486 /* R is not yet sufficiently initialized, so we
10487 just use its name. */
10490 }
10492 /* Wait until cp_finish_decl to set this again, to handle
10493 circular dependency (template/instantiate6.C). */
10498 {
10503 {
10506 }
10508 }
10509 }
10515 /* Clear out the mangled name and RTL for the instantiation. */
10519 /* The initializer must not be expanded until it is required;
10520 see [temp.inst]. */
10526 {
10527 /* Possibly limit visibility based on template args. */
10530 {
10534 }
10536 }
10539 {
10540 /* A static data member declaration is always marked
10541 external when it is declared in-class, even if an
10542 initializer is present. We mimic the non-template
10543 processing here. */
10549 }
10551 {
10552 /* We're substituting this var in a decltype outside of its
10553 scope, such as for a lambda return type. Don't add it to
10554 local_specializations, do perform auto deduction. */
10557 {
10558 tree init
10564 }
10565 }
10566 else
10575 /* Preserve a typedef that names a type. */
10577 {
10580 }
10583 }
10588 }
10589 #undef RETURN
10591 out:
10592 /* Restore the file and line information. */
10596 }
10598 /* Substitute into the ARG_TYPES of a function type.
10599 If END is a TREE_CHAIN, leave it and any following types
10600 un-substituted. */
10602 static tree
10604 tree args,
10605 tree end,
10606 tsubst_flags_t complain,
10607 tree in_decl)
10608 {
10609 tree remaining_arg_types;
10613 tree default_arg;
10624 {
10625 /* For a pack expansion, perform substitution on the
10626 entire expression. Later on, we'll handle the arguments
10627 one-by-one. */
10632 /* So that we'll spin through the parameters, one by one. */
10634 else
10635 {
10636 /* We only partially substituted into the parameter
10637 pack. Our type is TYPE_PACK_EXPANSION. */
10640 }
10641 }
10654 {
10656 {
10660 }
10662 }
10664 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10665 top-level qualifiers as required. */
10668 /* We do not substitute into default arguments here. The standard
10669 mandates that they be instantiated only when needed, which is
10670 done in build_over_call. */
10674 {
10675 /* We've instantiated a template before its default arguments
10676 have been parsed. This can happen for a nested template
10677 class, and is not an error unless we require the default
10678 argument in a call of this function. */
10679 remaining_arg_types =
10682 remaining_arg_types);
10683 }
10684 else
10685 remaining_arg_types =
10687 }
10690 }
10692 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10693 *not* handle the exception-specification for FNTYPE, because the
10694 initial substitution of explicitly provided template parameters
10695 during argument deduction forbids substitution into the
10696 exception-specification:
10698 [temp.deduct]
10700 All references in the function type of the function template to the
10701 corresponding template parameters are replaced by the specified tem-
10702 plate argument values. If a substitution in a template parameter or
10703 in the function type of the function template results in an invalid
10704 type, type deduction fails. [Note: The equivalent substitution in
10705 exception specifications is done only when the function is instanti-
10706 ated, at which point a program is ill-formed if the substitution
10707 results in an invalid type.] */
10709 static tree
10711 tree args,
10712 tsubst_flags_t complain,
10713 tree in_decl)
10714 {
10715 tree return_type;
10716 tree arg_types;
10717 tree fntype;
10719 /* The TYPE_CONTEXT is not used for function/method types. */
10722 /* Substitute the return type. */
10726 /* The standard does not presently indicate that creation of a
10727 function type with an invalid return type is a deduction failure.
10728 However, that is clearly analogous to creating an array of "void"
10729 or a reference to a reference. This is core issue #486. */
10732 {
10734 {
10737 else
10739 }
10741 }
10743 /* Substitute the argument types. */
10749 /* Construct a new type node and return it. */
10751 {
10754 }
10755 else
10756 {
10759 {
10760 /* [temp.deduct]
10762 Type deduction may fail for any of the following
10763 reasons:
10765 -- Attempting to create "pointer to member of T" when T
10766 is not a class type. */
10769 r);
10771 }
10775 }
10779 }
10781 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10782 ARGS into that specification, and return the substituted
10783 specification. If there is no specification, return NULL_TREE. */
10785 static tree
10787 tree args,
10788 tsubst_flags_t complain,
10789 tree in_decl,
10791 {
10792 tree specs;
10793 tree new_specs;
10798 {
10799 /* A noexcept-specifier. */
10804 {
10805 /* Defer instantiation of noexcept-specifiers to avoid
10806 excessive instantiations (c++/49107). */
10809 {
10810 /* We already partially instantiated this member template,
10811 so combine the new args with the old. */
10816 }
10817 else
10818 {
10821 }
10822 }
10823 else
10824 new_specs = tsubst_copy_and_build
10828 }
10830 {
10833 else
10835 {
10836 tree spec;
10841 {
10842 /* Expand the pack expansion type. */
10845 in_decl);
10851 else
10852 {
10853 /* We're substituting into a member template, so
10854 we got a TYPE_PACK_EXPANSION back. Add that
10855 expansion and move on. */
10859 expanded_specs,
10860 complain);
10863 }
10864 }
10867 {
10870 else
10875 complain);
10876 }
10879 }
10880 }
10882 }
10884 /* Take the tree structure T and replace template parameters used
10885 therein with the argument vector ARGS. IN_DECL is an associated
10886 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10887 Issue error and warning messages under control of COMPLAIN. Note
10888 that we must be relatively non-tolerant of extensions here, in
10889 order to preserve conformance; if we allow substitutions that
10890 should not be allowed, we may allow argument deductions that should
10891 not succeed, and therefore report ambiguous overload situations
10892 where there are none. In theory, we could allow the substitution,
10893 but indicate that it should have failed, and allow our caller to
10894 make sure that the right thing happens, but we don't try to do this
10895 yet.
10897 This function is used for dealing with types, decls and the like;
10898 for expressions, use tsubst_expr or tsubst_copy. */
10900 tree
10902 {
10925 else
10930 /* Reuse typedefs. We need to do this to handle dependent attributes,
10931 such as attribute aligned. */
10934 {
10941 {
10942 /* DECL represents an alias template and we want to
10943 instantiate it. Let's substitute our arguments for the
10944 template parameters into the declaration and get the
10945 resulting type. */
10947 }
10951 {
10955 }
10960 else
10961 /* The typedef is from a non-template context. */
10965 {
10967 r = cp_build_qualified_type_real
10971 }
10972 else
10973 /* We don't have an instantiation yet, so drop the typedef. */
10975 }
10988 {
11014 {
11020 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11021 needed. */
11027 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11028 with TREE_SIDE_EFFECTS that indicates this is not an integral
11029 constant expression. */
11032 {
11035 }
11038 }
11044 {
11057 {
11061 /* See through ARGUMENT_PACK_SELECT arguments. */
11063 }
11068 {
11070 /* If ARG is an argument pack, we don't actually want to
11071 perform a substitution here, because substitutions
11072 for argument packs are only done
11073 element-by-element. We can get to this point when
11074 substituting the type of a non-type template
11075 parameter pack, when that type actually contains
11076 template parameter packs from an outer template, e.g.,
11078 template<typename... Types> struct A {
11079 template<Types... Values> struct B { };
11080 }; */
11084 {
11090 return cp_build_qualified_type_real
11092 }
11094 {
11095 /* We are processing a type constructed from a
11096 template template parameter. */
11107 /* Consider this code:
11109 template <template <class> class Template>
11110 struct Internal {
11111 template <class Arg> using Bind = Template<Arg>;
11112 };
11114 template <template <class> class Template, class Arg>
11115 using Instantiate = Template<Arg>; //#0
11117 template <template <class> class Template,
11118 class Argument>
11119 using Bind =
11120 Instantiate<Internal<Template>::template Bind,
11121 Argument>; //#1
11123 When #1 is parsed, the
11124 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11125 parameter `Template' in #0 matches the
11126 UNBOUND_CLASS_TEMPLATE representing the argument
11127 `Internal<Template>::template Bind'; We then want
11128 to assemble the type `Bind<Argument>' that can't
11129 be fully created right now, because
11130 `Internal<Template>' not being complete, the Bind
11131 template cannot be looked up in that context. So
11132 we need to "store" `Bind<Argument>' for later
11133 when the context of Bind becomes complete. Let's
11134 store that in a TYPENAME_TYPE. */
11138 argvec),
11139 typename_type,
11140 complain);
11142 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11143 are resolving nested-types in the signature of a
11144 member function templates. Otherwise ARG is a
11145 TEMPLATE_DECL and is the real template to be
11146 instantiated. */
11154 complain);
11155 return cp_build_qualified_type_real
11157 }
11158 else
11159 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11161 }
11164 /* This can happen during the attempted tsubst'ing in
11165 unify. This means that we don't yet have any information
11166 about the template parameter in question. */
11169 /* Early in template argument deduction substitution, we don't
11170 want to reduce the level of 'auto', or it will be confused
11171 with a normal template parm in subsequent deduction. */
11175 /* If we get here, we must have been looking at a parm for a
11176 more deeply nested template. Make a new version of this
11177 template parameter, but with a lower level. */
11179 {
11184 {
11186 r = cp_build_qualified_type_real
11190 }
11191 else
11192 {
11203 /* We have reduced the level of the template
11204 template parameter, but not the levels of its
11205 template parameters, so canonical_type_parameter
11206 will not be able to find the canonical template
11207 template parameter for this level. Thus, we
11208 require structural equality checking to compare
11209 TEMPLATE_TEMPLATE_PARMs. */
11213 else
11217 {
11225 }
11226 }
11235 }
11238 }
11241 {
11249 {
11253 }
11256 {
11260 }
11263 {
11267 }
11273 }
11276 /* We should never be tsubsting a binfo. */
11280 /* A vector of template arguments. */
11286 {
11290 /* [temp.deduct]
11292 Type deduction may fail for any of the following
11293 reasons:
11295 -- Attempting to create a pointer to reference type.
11296 -- Attempting to create a reference to a reference type or
11297 a reference to void.
11299 Core issue 106 says that creating a reference to a reference
11300 during instantiation is no longer a cause for failure. We
11301 only enforce this check in strict C++98 mode. */
11305 {
11308 /* We keep track of the last time we issued this error
11309 message to avoid spewing a ton of messages during a
11310 single bad template instantiation. */
11313 {
11318 else
11321 }
11324 }
11326 {
11330 }
11332 /* In C++0x, during template argument substitution, when there is an
11333 attempt to create a reference to a reference type, reference
11334 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11336 "If a template-argument for a template-parameter T names a type
11337 that is a reference to a type A, an attempt to create the type
11338 'lvalue reference to cv T' creates the type 'lvalue reference to
11339 A,' while an attempt to create the type type rvalue reference to
11340 cv T' creates the type T"
11341 */
11342 r = cp_build_reference_type
11345 else
11350 /* Will this ever be needed for TYPE_..._TO values? */
11354 }
11356 {
11359 {
11360 /* [temp.deduct]
11362 Type deduction may fail for any of the following
11363 reasons:
11365 -- Attempting to create "pointer to member of T" when T
11366 is not a class type. */
11370 }
11372 {
11376 }
11378 {
11382 }
11385 {
11386 /* The type of the implicit object parameter gets its
11387 cv-qualifiers from the FUNCTION_TYPE. */
11388 tree memptr;
11392 complain);
11393 }
11394 else
11397 complain);
11398 }
11401 {
11402 tree fntype;
11403 tree specs;
11408 /* Substitute the exception specification. */
11416 }
11418 {
11423 /* As an optimization, we avoid regenerating the array type if
11424 it will obviously be the same as T. */
11428 /* These checks should match the ones in grokdeclarator.
11430 [temp.deduct]
11432 The deduction may fail for any of the following reasons:
11434 -- Attempting to create an array with an element type that
11435 is void, a function type, or a reference type, or [DR337]
11436 an abstract class type. */
11440 {
11444 }
11446 {
11449 type);
11451 }
11456 {
11459 }
11462 }
11465 {
11475 {
11479 }
11481 {
11482 /* Normally, make_typename_type does not require that the CTX
11483 have complete type in order to allow things like:
11485 template <class T> struct S { typename S<T>::X Y; };
11487 But, such constructs have already been resolved by this
11488 point, so here CTX really should have complete type, unless
11489 it's a partial instantiation. */
11492 {
11496 }
11497 }
11504 {
11507 }
11510 {
11512 {
11516 else
11518 }
11520 {
11524 else
11526 }
11527 }
11529 return cp_build_qualified_type_real
11531 }
11534 {
11546 }
11549 {
11550 tree type;
11566 complain);
11567 }
11570 {
11571 tree type;
11587 else
11588 type = finish_decltype_type
11593 complain);
11594 }
11597 {
11601 }
11605 {
11607 tree packed_out =
11609 args,
11610 complain,
11611 in_decl);
11614 /* For template nontype argument packs, also substitute into
11615 the type. */
11620 }
11635 /* We should use one of the expression tsubsts for these codes. */
11641 }
11642 }
11644 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11645 type of the expression on the left-hand side of the "." or "->"
11646 operator. */
11648 static tree
11651 {
11652 tree name;
11653 tree qualifying_scope;
11654 tree fns;
11655 tree optype;
11660 /* A baselink indicates a function from a base class. Both the
11661 BASELINK_ACCESS_BINFO and the base class referenced may
11662 indicate bases of the template class, rather than the
11663 instantiated class. In addition, lookups that were not
11664 ambiguous before may be ambiguous now. Therefore, we perform
11665 the lookup again. */
11672 {
11679 }
11687 /* If lookup found a single function, mark it as used at this
11688 point. (If it lookup found multiple functions the one selected
11689 later by overload resolution will be marked as used at that
11690 point.) */
11696 /* Add back the template arguments, if present. */
11701 template_args);
11702 /* Update the conversion operator type. */
11710 qualifying_scope,
11711 object_type);
11713 }
11715 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11716 true if the qualified-id will be a postfix-expression in-and-of
11717 itself; false if more of the postfix-expression follows the
11718 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11719 of "&". */
11721 static tree
11725 {
11726 tree expr;
11727 tree scope;
11728 tree name;
11730 tree template_args;
11735 /* Figure out what name to look up. */
11738 {
11746 }
11747 else
11748 {
11751 }
11753 /* Substitute into the qualifying scope. When there are no ARGS, we
11754 are just trying to simplify a non-dependent expression. In that
11755 case the qualifying scope may be dependent, and, in any case,
11756 substituting will not help. */
11759 {
11762 }
11763 else
11767 {
11772 }
11775 {
11777 {
11778 /* A BIT_NOT_EXPR is used to represent a destructor. */
11780 {
11784 }
11785 else
11788 }
11789 else
11793 {
11795 {
11799 }
11801 }
11802 }
11805 {
11807 scope);
11808 /* Remember that there was a reference to this entity. */
11810 }
11813 {
11819 }
11828 {
11829 expr = (adjust_result_of_qualified_name_lookup
11831 expr = (finish_qualified_id_expr
11835 }
11837 /* Expressions do not generally have reference type. */
11839 /* However, if we're about to form a pointer-to-member, we just
11840 want the referenced member referenced. */
11845 }
11847 /* Like tsubst, but deals with expressions. This function just replaces
11848 template parms; to finish processing the resultant expression, use
11849 tsubst_copy_and_build or tsubst_expr. */
11851 static tree
11853 {
11855 tree r;
11863 {
11868 {
11869 /* We get here for a use of 'this' in an NSDMI. */
11875 /* This can happen for a parameter name used later in a function
11876 declaration (such as in a late-specified return type). Just
11877 make a dummy decl, since it's only used for its type. */
11880 /* Give it the template pattern as its context; its true context
11881 hasn't been instantiated yet and this is good enough for
11882 mangling. */
11884 }
11892 {
11893 tree enum_type;
11894 tree v;
11898 /* There is no need to substitute into namespace-scope
11899 enumerators. */
11902 /* If ARGS is NULL, then T is known to be non-dependent. */
11906 /* Unfortunately, we cannot just call lookup_name here.
11907 Consider:
11909 template <int I> int f() {
11910 enum E { a = I };
11911 struct S { void g() { E e = a; } };
11912 };
11914 When we instantiate f<7>::S::g(), say, lookup_name is not
11915 clever enough to find f<7>::a. */
11916 enum_type
11926 /* We didn't find the name. That should never happen; if
11927 name-lookup found it during preliminary parsing, we
11928 should find it again here during instantiation. */
11930 }
11935 {
11936 tree ctx;
11941 {
11944 {
11948 }
11950 }
11951 }
11967 /* An OVERLOAD will always be a non-dependent overload set; an
11968 overload set from function scope will just be represented with an
11969 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11984 {
11985 /* Template template argument like the following example need
11986 special treatment:
11988 template <template <class> class TT> struct C {};
11989 template <class T> struct D {
11990 template <class U> struct E {};
11991 C<E> c; // #1
11992 };
11993 D<int> d; // #2
11995 We are processing the template argument `E' in #1 for
11996 the template instantiation #2. Originally, `E' is a
11997 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11998 have to substitute this with one having context `D<int>'. */
12002 }
12003 else
12004 /* Ordinary template template argument. */
12015 return build1
12021 {
12023 tree expanded;
12028 /* We only want to compute the number of arguments. */
12043 {
12050 else
12053 }
12054 else
12056 }
12057 /* Fall through */
12072 return build1
12077 {
12078 tree object;
12079 tree name;
12084 {
12088 }
12091 {
12101 }
12106 in_decl);
12107 else
12110 }
12148 return build_nt
12161 return build_nt
12168 {
12176 }
12181 {
12182 r = build_nt
12188 }
12191 {
12192 r = build_nt
12198 }
12201 {
12202 r = build_nt
12208 }
12211 {
12212 /* Substituted template arguments */
12221 }
12224 {
12244 }
12269 {
12272 }
12273 else
12277 /* This is handled by tsubst_copy_and_build. */
12283 in_decl),
12287 /* We shouldn't have built any of these during initial template
12288 generation. Instead, they should be built during instantiation
12289 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12293 r = build2
12313 {
12314 /* Instantiate any typedefs in the type. */
12319 }
12322 /* These can sometimes show up in a partial instantiation, but never
12323 involve template parms. */
12328 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12331 }
12332 }
12334 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12336 static tree
12338 tree in_decl)
12339 {
12343 {
12349 {
12352 {
12358 }
12359 /* FALLTHRU */
12383 }
12384 }
12387 }
12389 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12391 static tree
12393 tree in_decl)
12394 {
12395 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12415 {
12418 else
12419 {
12423 }
12424 }
12429 #undef RECUR
12430 }
12432 /* Substitute one OMP_FOR iterator. */
12434 static void
12439 {
12440 #define RECUR(NODE) \
12441 tsubst_expr ((NODE), args, complain, in_decl, \
12442 integral_constant_expression_p)
12450 /* Do this before substituting into decl to handle 'auto'. */
12455 {
12459 }
12464 {
12471 complain);
12472 else
12479 }
12482 {
12483 tree c;
12485 {
12496 }
12498 {
12503 {
12506 }
12507 }
12508 }
12514 else
12518 {
12529 {
12536 }
12537 else
12543 {
12549 }
12553 {
12560 }
12561 else
12567 }
12573 #undef RECUR
12574 }
12576 /* Like tsubst_copy for expressions, etc. but also does semantic
12577 processing. */
12579 static tree
12582 {
12583 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12584 #define RECUR(NODE) \
12585 tsubst_expr ((NODE), args, complain, in_decl, \
12586 integral_constant_expression_p)
12589 tree r;
12590 location_t loc;
12602 {
12604 {
12605 tree_stmt_iterator i;
12609 }
12624 else
12633 {
12635 tree init;
12641 {
12644 tree decl;
12652 else
12654 }
12655 else
12656 {
12660 {
12661 /* By marking the declaration as instantiated, we avoid
12662 trying to instantiate it. Since instantiate_decl can't
12663 handle local variables, and since we've already done
12664 all that needs to be done, that's the right thing to
12665 do. */
12670 /* Anonymous aggregates are a special case. */
12673 {
12676 }
12679 else
12680 {
12685 {
12686 /* For __PRETTY_FUNCTION__ we have to adjust the
12687 initializer. */
12691 }
12692 else
12693 {
12697 {
12698 /* If we had an initializer but it
12699 instantiated to nothing,
12700 value-initialize the object. This will
12701 only occur when the initializer was a
12702 pack expansion where the parameter packs
12703 used in that expansion were of length
12704 zero. */
12706 complain);
12709 }
12710 else
12712 }
12715 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12718 }
12719 }
12720 }
12723 }
12738 {
12748 }
12775 {
12779 }
12787 else
12795 else
12822 {
12824 tree label;
12829 }
12835 /* Computed goto's must be tsubst'd into. On the other hand,
12836 non-computed gotos must not be; the identifier in question
12837 will have no binding. */
12839 else
12845 tmp = finish_asm_stmt
12852 {
12857 }
12862 {
12867 }
12868 else
12869 {
12874 else
12881 else
12887 else
12889 }
12893 {
12897 {
12899 /* Prevent instantiate_decl from trying to instantiate
12900 this variable. We've already done all that needs to be
12901 done. */
12904 }
12909 }
12915 {
12916 /* Local classes are not independent templates; they are
12917 instantiated along with their containing function. And this
12918 way we don't have to deal with pushing out of one local class
12919 to instantiate a member of another local class. */
12920 tree fn;
12921 /* Closures are handled by the LAMBDA_EXPR. */
12927 }
12931 {
12932 tree condition;
12935 condition =
12937 args,
12946 }
12967 {
12984 integral_constant_expression_p);
12998 }
13030 {
13035 {
13038 }
13043 }
13044 else
13045 {
13052 {
13055 }
13058 {
13063 {
13066 }
13070 }
13071 else
13072 {
13076 }
13078 }
13082 {
13088 {
13092 {
13097 }
13101 }
13102 else
13103 {
13108 }
13109 }
13127 /* If the first operand was a statement, we're done with it. */
13131 complain));
13138 integral_constant_expression_p));
13139 }
13142 out:
13145 #undef RECUR
13146 #undef RETURN
13147 }
13149 /* T is a postfix-expression that is not being used in a function
13150 call. Return the substituted version of T. */
13152 static tree
13154 tsubst_flags_t complain,
13155 tree in_decl)
13156 {
13160 else
13166 }
13168 /* Like tsubst but deals with expressions and performs semantic
13169 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13171 tree
13173 tree args,
13174 tsubst_flags_t complain,
13175 tree in_decl,
13178 {
13179 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13180 #define RECUR(NODE) \
13181 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13183 integral_constant_expression_p)
13186 location_t loc;
13196 {
13199 /* Fall through. */
13201 {
13202 tree decl;
13203 cp_id_kind idk;
13208 {
13211 }
13213 /* Look up the name. */
13216 /* By convention, expressions use ERROR_MARK_NODE to indicate
13217 failure, not NULL_TREE. */
13223 integral_constant_expression_p,
13231 input_location);
13235 {
13239 }
13241 }
13244 {
13245 tree object;
13253 {
13256 }
13257 else
13264 else
13266 }
13269 {
13273 {
13274 /* A type conversion to reference type will be enclosed in
13275 such an indirect ref, but the substitution of the cast
13276 will have also added such an indirect ref. */
13279 }
13280 else
13283 }
13291 {
13298 flags));
13299 }
13312 {
13313 tree type;
13319 {
13324 }
13330 {
13348 }
13352 }
13384 else
13386 in_decl);
13420 {
13421 tree r;
13425 r = build_x_binary_op
13429 ? ERROR_MARK
13433 ? ERROR_MARK
13436 complain);
13443 }
13457 /* Fall through */
13462 {
13463 /* When there are no ARGS, we are trying to evaluate a
13464 non-dependent expression from the parser. Trying to do
13465 the substitutions may not work. */
13468 }
13469 else
13470 {
13478 }
13482 else
13487 {
13497 }
13511 {
13512 tree r = build_x_modify_expr
13517 complain);
13518 /* TREE_NO_WARNING must be set if either the expression was
13519 parenthesized or it uses an operator such as >>= rather
13520 than plain assignment. In the former case, it was already
13521 set and must be copied. In the latter case,
13522 build_x_modify_expr sets it and it must not be reset
13523 here. */
13527 }
13532 /* Remember that there was a reference to this entity. */
13538 {
13543 tree ret;
13547 else
13548 {
13552 }
13554 /* If there was an initializer in the original tree, but it
13555 instantiated to an empty list, then we should pass a
13556 non-NULL empty vector to tell build_new that it was an
13557 empty initializer() rather than no initializer. This can
13558 only happen when the initializer is a pack expansion whose
13559 parameter packs are of length zero. */
13562 else
13563 {
13567 else
13568 {
13571 }
13572 }
13579 complain);
13587 }
13595 complain));
13601 complain));
13604 {
13605 tree function;
13610 tree ret;
13613 /* When we parsed the expression, we determined whether or
13614 not Koenig lookup should be performed. */
13617 {
13622 }
13624 {
13625 /* Do nothing; calling tsubst_copy_and_build on an identifier
13626 would incorrectly perform unqualified lookup again.
13628 Note that we can also have an IDENTIFIER_NODE if the earlier
13629 unqualified lookup found a member function; in that case
13630 koenig_p will be false and we do want to do the lookup
13631 again to find the instantiated member function.
13633 FIXME but doing that causes c++/15272, so we need to stop
13634 using IDENTIFIER_NODE in that situation. */
13636 }
13637 else
13638 {
13640 {
13646 }
13647 else
13651 in_decl,
13653 integral_constant_expression_p);
13657 }
13662 {
13668 else
13669 {
13670 /* Expand the pack expansion and push each entry onto
13671 CALL_ARGS. */
13674 {
13679 {
13684 }
13685 }
13686 else
13687 {
13688 /* A partial substitution. Add one entry. */
13690 }
13691 }
13692 }
13694 /* We do not perform argument-dependent lookup if normal
13695 lookup finds a non-function, in accordance with the
13696 expected resolution of DR 218. */
13699 /* If lookup found a member function, the Koenig lookup is
13700 not appropriate, even if an unqualified-name was used
13701 to denote the function. */
13704 /* Only do this when substitution turns a dependent call
13705 into a non-dependent call. */
13709 tf_none);
13713 {
13715 {
13716 /* For backwards compatibility and good diagnostics, try
13717 the unqualified lookup again if we aren't in SFINAE
13718 context. */
13719 tree unq = (tsubst_copy_and_build
13721 integral_constant_expression_p));
13726 {
13735 "%qD was not declared in this scope, "
13736 "and no declarations were found by "
13737 "argument-dependent lookup at the point "
13742 {
13744 "declarations in dependent base %qT are "
13750 else
13754 }
13755 else
13759 }
13760 }
13762 {
13766 }
13767 }
13769 /* Remember that there was a reference to this entity. */
13776 {
13791 complain);
13792 else
13793 ret = (build_new_method_call
13798 complain));
13799 }
13800 else
13803 koenig_p,
13804 complain);
13809 }
13812 {
13817 {
13819 {
13824 }
13825 else
13826 {
13831 }
13832 }
13833 else
13834 {
13837 }
13841 }
13850 {
13858 {
13859 /* We have pack expansions, so expand those and
13860 create a new list out of it. */
13863 tree chain;
13866 /* Expand the argument expressions. */
13874 /* Build the rest of the list. */
13879 /* Determine the number of arguments. */
13881 {
13884 }
13887 else
13888 {
13889 /* Since we only performed a partial substitution into
13890 the argument pack, we only RETURN (a single list
13891 node. */
13898 }
13900 /* Convert the argument vectors into a TREE_LIST */
13903 {
13904 /* Grab the Ith values. */
13905 i--;
13908 value
13912 /* Build the list (backwards). */
13914 }
13917 }
13933 }
13936 {
13937 tree object;
13938 tree object_type;
13939 tree member;
13943 /* Remember that there was a reference to this entity. */
13953 else
13961 {
13963 {
13968 {
13971 }
13973 {
13977 }
13978 }
13979 }
13982 {
13983 /* Lookup the template functions now that we know what the
13984 scope is. */
13992 {
13995 args);
13996 member = (adjust_result_of_qualified_name_lookup
13998 object_type));
13999 }
14000 else
14001 {
14003 input_location);
14005 }
14006 }
14010 {
14012 {
14016 else
14019 }
14021 }
14027 complain));
14028 }
14035 {
14043 tree r;
14048 /* digest_init will do the wrong thing if we let it. */
14052 /* We do not want to process the index of aggregate
14053 initializers as they are identifier nodes which will be
14054 looked up by digest_init. */
14060 {
14065 {
14066 /* Substitute into the pack expansion. */
14068 in_decl);
14072 ;
14074 /* Just move the argument into place. */
14076 else
14077 {
14078 /* Update the length of the final CONSTRUCTOR
14079 arguments vector, and note that we will need to
14080 copy.*/
14083 }
14084 }
14085 else
14087 }
14090 {
14095 {
14097 {
14102 }
14103 else
14105 }
14106 }
14116 }
14119 {
14122 {
14125 }
14126 else
14127 {
14130 }
14131 }
14136 /* Fall through */
14139 {
14143 /* If the original type was a reference, we'll be wrapped in
14144 the appropriate INDIRECT_REF. */
14147 }
14158 {
14167 }
14170 {
14176 integral_constant_expression_p);
14180 /* If the resulting list of expression statement is empty,
14181 fold it further into void_zero_node. */
14186 }
14189 {
14211 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14213 /* Now that we know visibility, instantiate the type so we have a
14214 declaration of the op() for later calls to lambda_function. */
14217 /* The capture list refers to closure members, so this needs to
14218 wait until after we finish instantiating the type. */
14223 }
14226 /* We can get here for a constant initializer of non-dependent type.
14227 FIXME stop folding in cp_parser_initializer_clause. */
14229 {
14233 }
14237 integral_constant_expression_p));
14240 /* Handle Objective-C++ constructs, if appropriate. */
14241 {
14242 tree subst
14247 }
14249 }
14251 #undef RECUR
14252 #undef RETURN
14253 out:
14256 }
14258 /* Verify that the instantiated ARGS are valid. For type arguments,
14259 make sure that the type's linkage is ok. For non-type arguments,
14260 make sure they are constants if they are integral or enumerations.
14261 Emit an error under control of COMPLAIN, and return TRUE on error. */
14263 static bool
14265 {
14267 {
14277 }
14279 {
14280 /* [basic.link]: A name with no linkage (notably, the name
14281 of a class or enumeration declared in a local scope)
14282 shall not be used to declare an entity with linkage.
14283 This implies that names with no linkage cannot be used as
14284 template arguments
14286 DR 757 relaxes this restriction for C++0x. */
14291 {
14292 /* DR 488 makes use of a type with no linkage cause
14293 type deduction to fail. */
14295 {
14298 else
14301 }
14303 }
14304 /* In order to avoid all sorts of complications, we do not
14305 allow variably-modified types as template arguments. */
14307 {
14311 }
14312 }
14313 /* A non-type argument of integral or enumerated type must be a
14314 constant. */
14318 {
14322 }
14324 }
14326 static bool
14328 {
14333 {
14336 }
14340 }
14342 /* We're out of SFINAE context now, so generate diagnostics for the access
14343 errors we saw earlier when instantiating D from TMPL and ARGS. */
14345 static void
14347 {
14359 }
14361 /* Instantiate the indicated variable or function template TMPL with
14362 the template arguments in TARG_PTR. */
14364 static tree
14366 {
14368 tree fndecl;
14369 tree gen_tmpl;
14370 tree spec;
14378 /* If this function is a clone, handle it specially. */
14380 {
14381 tree spec;
14382 tree clone;
14384 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14385 DECL_CLONED_FUNCTION. */
14391 /* Look for the clone. */
14395 /* We should always have found the clone by now. */
14398 }
14400 /* Check to see if we already have this specialization. */
14403 /* The TMPL is a partial instantiation. To get a full set of
14404 arguments we must add the arguments used to perform the
14405 partial instantiation. */
14407 targ_ptr);
14409 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14410 but it doesn't seem to be on the hot path. */
14419 {
14421 {
14425 }
14427 }
14430 complain))
14433 /* We are building a FUNCTION_DECL, during which the access of its
14434 parameters and return types have to be checked. However this
14435 FUNCTION_DECL which is the desired context for access checking
14436 is not built yet. We solve this chicken-and-egg problem by
14437 deferring all checks until we have the FUNCTION_DECL. */
14440 /* Instantiation of the function happens in the context of the function
14441 template, not the context of the overload resolution we're doing. */
14443 /* If there are dependent arguments, e.g. because we're doing partial
14444 ordering, make sure processing_template_decl stays set. */
14448 {
14452 }
14453 /* Substitute template parameters to obtain the specialization. */
14461 {
14464 }
14466 /* The DECL_TI_TEMPLATE should always be the immediate parent
14467 template, not the most general template. */
14470 /* Now we know the specialization, compute access previously
14471 deferred. */
14478 /* If we've just instantiated the main entry point for a function,
14479 instantiate all the alternate entry points as well. We do this
14480 by cloning the instantiation of the main entry point, not by
14481 instantiating the template clones. */
14486 {
14488 {
14489 /* Remember to reinstantiate when we're out of SFINAE so the user
14490 can see the errors. */
14492 }
14494 }
14496 }
14498 /* Wrapper for instantiate_template_1. */
14500 tree
14502 {
14503 tree ret;
14508 }
14510 /* PARM is a template parameter pack for FN. Returns true iff
14511 PARM is used in a deducible way in the argument list of FN. */
14513 static bool
14515 {
14518 {
14520 tree packs;
14526 {
14527 /* The template parameter pack is used in a function parameter
14528 pack. If this is the end of the parameter list, the
14529 template parameter pack is deducible. */
14532 else
14533 /* Otherwise, not. Well, it could be deduced from
14534 a non-pack parameter, but doing so would end up with
14535 a deduction mismatch, so don't bother. */
14537 }
14538 }
14539 /* The template parameter pack isn't used in any function parameter
14540 packs, but it might be used deeper, e.g. tuple<Args...>. */
14542 }
14544 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14545 NARGS elements of the arguments that are being used when calling
14546 it. TARGS is a vector into which the deduced template arguments
14547 are placed.
14549 Return zero for success, 2 for an incomplete match that doesn't resolve
14550 all the types, and 1 for complete failure. An error message will be
14551 printed only for an incomplete match.
14553 If FN is a conversion operator, or we are trying to produce a specific
14554 specialization, RETURN_TYPE is the return type desired.
14556 The EXPLICIT_TARGS are explicit template arguments provided via a
14557 template-id.
14559 The parameter STRICT is one of:
14561 DEDUCE_CALL:
14562 We are deducing arguments for a function call, as in
14563 [temp.deduct.call].
14565 DEDUCE_CONV:
14566 We are deducing arguments for a conversion function, as in
14567 [temp.deduct.conv].
14569 DEDUCE_EXACT:
14570 We are deducing arguments when doing an explicit instantiation
14571 as in [temp.explicit], when determining an explicit specialization
14572 as in [temp.expl.spec], or when taking the address of a function
14573 template, as in [temp.deduct.funcaddr]. */
14575 tree
14577 tree explicit_targs,
14578 tree targs,
14581 tree return_type,
14582 unification_kind_t strict,
14585 {
14586 tree parms;
14587 tree fntype;
14595 tree tinst;
14598 /* Adjust any explicit template arguments before entering the
14599 substitution context. */
14601 {
14602 explicit_targs
14604 complain,
14609 }
14611 /* In C++0x, it's possible to have a function template whose type depends
14612 on itself recursively. This is most obvious with decltype, but can also
14613 occur with enumeration scope (c++/48969). So we need to catch infinite
14614 recursion and reject the substitution at deduction time; this function
14615 will return error_mark_node for any repeated substitution.
14617 This also catches excessive recursion such as when f<N> depends on
14618 f<N-1> across all integers, and returns error_mark_node for all the
14619 substitutions back up to the initial one.
14621 This is, of course, not reentrant. */
14626 {
14630 }
14638 {
14639 /* [temp.deduct]
14641 The specified template arguments must match the template
14642 parameters in kind (i.e., type, nontype, template), and there
14643 must not be more arguments than there are parameters;
14644 otherwise type deduction fails.
14646 Nontype arguments must match the types of the corresponding
14647 nontype template parameters, or must be convertible to the
14648 types of the corresponding nontype parameters as specified in
14649 _temp.arg.nontype_, otherwise type deduction fails.
14651 All references in the function type of the function template
14652 to the corresponding template parameters are replaced by the
14653 specified template argument values. If a substitution in a
14654 template parameter or in the function type of the function
14655 template results in an invalid type, type deduction fails. */
14660 /* Substitute the explicit args into the function type. This is
14661 necessary so that, for instance, explicitly declared function
14662 arguments can match null pointed constants. If we were given
14663 an incomplete set of explicit args, we must not do semantic
14664 processing during substitution as we could create partial
14665 instantiations. */
14667 {
14672 /* Dig out the actual parm. */
14675 {
14678 }
14680 {
14683 }
14686 /* No explicit argument for this template parameter. */
14690 {
14691 /* Mark the argument pack as "incomplete". We could
14692 still deduce more arguments during unification.
14693 We remove this mark in type_unification_real. */
14695 {
14699 }
14701 /* We have some incomplete argument packs. */
14703 }
14704 }
14716 /* Place the explicitly specified arguments in TARGS. */
14719 }
14721 /* Never do unification on the 'this' parameter. */
14725 {
14734 }
14736 /* We allow incomplete unification without an error message here
14737 because the standard doesn't seem to explicitly prohibit it. Our
14738 callers must be ready to deal with unification failures in any
14739 event. */
14749 /* Now that we have bindings for all of the template arguments,
14750 ensure that the arguments deduced for the template template
14751 parameters have compatible template parameter lists. We cannot
14752 check this property before we have deduced all template
14753 arguments, because the template parameter types of a template
14754 template parameter might depend on prior template parameters
14755 deduced after the template template parameter. The following
14756 ill-formed example illustrates this issue:
14758 template<typename T, template<T> class C> void f(C<5>, T);
14760 template<int N> struct X {};
14762 void g() {
14763 f(X<5>(), 5l); // error: template argument deduction fails
14764 }
14766 The template parameter list of 'C' depends on the template type
14767 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14768 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14769 time that we deduce 'C'. */
14772 {
14775 }
14777 /* All is well so far. Now, check:
14779 [temp.deduct]
14781 When all template arguments have been deduced, all uses of
14782 template parameters in nondeduced contexts are replaced with
14783 the corresponding deduced argument values. If the
14784 substitution results in an invalid type, as described above,
14785 type deduction fails. */
14790 /* Now perform any access checks encountered during deduction, such as
14791 for default template arguments. */
14798 /* If we're looking for an exact match, check that what we got
14799 is indeed an exact match. It might not be if some template
14800 parameters are used in non-deduced contexts. */
14802 {
14806 tree sarg
14812 {
14816 }
14817 }
14821 fail:
14825 {
14827 /* Reset once we're all the way out. */
14829 }
14832 /* We can't free this if a pending_template entry or last_error_tinst_level
14833 is pointing at it. */
14839 }
14841 /* Adjust types before performing type deduction, as described in
14842 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14843 sections are symmetric. PARM is the type of a function parameter
14844 or the return type of the conversion function. ARG is the type of
14845 the argument passed to the call, or the type of the value
14846 initialized with the result of the conversion function.
14847 ARG_EXPR is the original argument expression, which may be null. */
14849 static int
14853 tree arg_expr)
14854 {
14858 {
14863 {
14864 /* Swap PARM and ARG throughout the remainder of this
14865 function; the handling is precisely symmetric since PARM
14866 will initialize ARG rather than vice versa. */
14871 }
14874 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14875 too, but here handle it by stripping the reference from PARM
14876 rather than by adding it to ARG. */
14884 /* Nothing else to do in this case. */
14889 }
14892 {
14893 /* [temp.deduct.call]
14895 If P is not a reference type:
14897 --If A is an array type, the pointer type produced by the
14898 array-to-pointer standard conversion (_conv.array_) is
14899 used in place of A for type deduction; otherwise,
14901 --If A is a function type, the pointer type produced by
14902 the function-to-pointer standard conversion
14903 (_conv.func_) is used in place of A for type deduction;
14904 otherwise,
14906 --If A is a cv-qualified type, the top level
14907 cv-qualifiers of A's type are ignored for type
14908 deduction. */
14913 else
14915 }
14917 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14918 of the form T&&, where T is a template parameter, and the argument
14919 is an lvalue, T is deduced as A& */
14925 /* try_one_overload doesn't provide an arg_expr, but
14926 functions are always lvalues. */
14930 /* [temp.deduct.call]
14932 If P is a cv-qualified type, the top level cv-qualifiers
14933 of P's type are ignored for type deduction. If P is a
14934 reference type, the type referred to by P is used for
14935 type deduction. */
14938 {
14941 }
14943 /* DR 322. For conversion deduction, remove a reference type on parm
14944 too (which has been swapped into ARG). */
14949 }
14951 /* Subroutine of unify_one_argument. PARM is a function parameter of a
14952 template which does contain any deducible template parameters; check if
14953 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
14954 unify_one_argument. */
14956 static int
14959 {
14960 tree type;
14964 else
14971 {
14975 }
14977 {
14982 }
14986 else
14988 }
14990 /* Subroutine of type_unification_real and unify_pack_expansion to
14991 handle unification of a single P/A pair. Parameters are as
14992 for those functions. */
14994 static int
14998 {
15005 /* We can't deduce anything from this, but we might get all the
15006 template args from other function args. */
15009 /* FIXME uses_deducible_template_parms */
15012 explain_p);
15015 {
15017 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15018 | UNIFY_ALLOW_MORE_CV_QUAL
15032 }
15034 /* We only do these transformations if this is the top-level
15035 parameter_type_list in a call or declaration matching; in other
15036 situations (nested function declarators, template argument lists) we
15037 won't be comparing a type to an expression, and we don't do any type
15038 adjustments. */
15040 {
15042 {
15045 {
15046 /* [temp.deduct.type] A template-argument can be
15047 deduced from a pointer to function or pointer
15048 to member function argument if the set of
15049 overloaded functions does not contain function
15050 templates and at most one of a set of
15051 overloaded functions provides a unique
15052 match. */
15059 }
15065 }
15067 arg_strict |=
15069 }
15070 else
15074 /* For deduction from an init-list we need the actual list. */
15078 }
15080 /* Most parms like fn_type_unification.
15082 If SUBR is 1, we're being called recursively (to unify the
15083 arguments of a function or method parameter of a function
15084 template). */
15086 static int
15088 tree targs,
15089 tree xparms,
15093 unification_kind_t strict,
15096 {
15101 tree parms;
15110 /* Reset the number of non-defaulted template arguments contained
15111 in TARGS. */
15114 again:
15122 {
15127 /* For a function parameter pack that occurs at the end of the
15128 parameter-declaration-list, the type A of each remaining
15129 argument of the call is compared with the type P of the
15130 declarator-id of the function parameter pack. */
15136 /* For a function parameter pack that does not occur at the
15137 end of the parameter-declaration-list, the type of the
15138 parameter pack is a non-deduced context. */
15147 }
15152 {
15153 /* Unify the remaining arguments with the pack expansion type. */
15154 tree argvec;
15157 /* Allocate a TREE_VEC and copy in all of the arguments */
15162 /* Copy the parameter into parmvec. */
15168 /* Advance to the end of the list of parameters. */
15170 }
15172 /* Fail if we've reached the end of the parm list, and more args
15173 are present, and the parm list isn't variadic. */
15176 /* Fail if parms are left and they don't have default values. */
15179 {
15183 {
15184 count++;
15186 }
15188 }
15191 {
15192 tsubst_flags_t complain = (explain_p
15193 ? tf_warning_or_error
15196 /* Check to see if we need another pass before we start clearing
15197 ARGUMENT_PACK_INCOMPLETE_P. */
15199 {
15207 /* If this is an undeduced nontype parameter that depends on
15208 a type parameter, try another pass; its type may have been
15209 deduced from a later argument than the one from which
15210 this parameter can be deduced. */
15215 }
15218 {
15222 /* Clear the "incomplete" flags on all argument packs now so that
15223 substituting them into later default arguments works. */
15225 {
15228 }
15234 /* Core issue #226 (C++0x) [temp.deduct]:
15236 If a template argument has not been deduced, its
15237 default template argument, if any, is used.
15239 When we are in C++98 mode, TREE_PURPOSE will either
15240 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15241 to explicitly check cxx_dialect here. */
15243 {
15255 else
15256 {
15258 /* The position of the first default template argument,
15259 is also the number of non-defaulted arguments in TARGS.
15260 Record that. */
15264 }
15265 }
15267 /* If the type parameter is a parameter pack, then it will
15268 be deduced to an empty parameter pack. */
15270 {
15271 tree arg;
15274 {
15278 }
15279 else
15286 }
15289 }
15290 }
15291 #ifdef ENABLE_CHECKING
15294 #endif
15297 }
15299 /* Subroutine of type_unification_real. Args are like the variables
15300 at the call site. ARG is an overloaded function (or template-id);
15301 we try deducing template args from each of the overloads, and if
15302 only one succeeds, we go with that. Modifies TARGS and returns
15303 true on success. */
15305 static bool
15307 tree targs,
15308 tree parm,
15309 tree arg,
15310 unification_kind_t strict,
15313 {
15320 {
15323 }
15324 else
15328 /* Handle `&x' where `x' is some static or non-static member
15329 function name. */
15335 /* Strip baselink information. */
15340 {
15341 /* If we got some explicit template args, we need to plug them into
15342 the affected templates before we try to unify, in case the
15343 explicit args will completely resolve the templates in question. */
15350 {
15363 {
15368 {
15371 }
15372 }
15375 }
15376 /* If no templates (or more than one) are fully resolved by the
15377 explicit arguments, this template-id is a non-deduced context; it
15378 could still be OK if we deduce all template arguments for the
15379 enclosing call through other arguments. */
15382 }
15385 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15386 -- but the deduction does not succeed because the expression is
15387 not just the function on its own. */
15389 else
15395 {
15398 }
15400 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15401 to function or pointer to member function argument if the set of
15402 overloaded functions does not contain function templates and at most
15403 one of a set of overloaded functions provides a unique match.
15405 So if we found multiple possibilities, we return success but don't
15406 deduce anything. */
15409 {
15414 }
15419 }
15421 /* Core DR 115: In contexts where deduction is done and fails, or in
15422 contexts where deduction is not done, if a template argument list is
15423 specified and it, along with any default template arguments, identifies
15424 a single function template specialization, then the template-id is an
15425 lvalue for the function template specialization. */
15427 tree
15429 {
15442 {
15445 }
15447 {
15450 }
15452 {
15455 }
15458 {
15462 /* If we got some explicit template args, we need to plug them into
15463 the affected templates before we try to unify, in case the
15464 explicit args will completely resolve the templates in question. */
15472 {
15485 {
15488 {
15491 }
15493 {
15496 }
15497 }
15498 }
15500 {
15508 {
15509 tree base
15512 }
15516 }
15518 /* There were no good options and at least one bad one, so let the
15519 user know what the problem is. */
15521 }
15523 }
15525 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15526 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15527 different overloads deduce different arguments for a given parm.
15528 ADDR_P is true if the expression for which deduction is being
15529 performed was of the form "& fn" rather than simply "fn".
15531 Returns 1 on success. */
15533 static int
15535 tree orig_targs,
15536 tree targs,
15537 tree parm,
15538 tree arg,
15539 unification_kind_t strict,
15543 {
15545 tree tempargs;
15551 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15552 to function or pointer to member function argument if the set of
15553 overloaded functions does not contain function templates and at most
15554 one of a set of overloaded functions provides a unique match.
15556 So if this is a template, just return success. */
15568 /* We don't copy orig_targs for this because if we have already deduced
15569 some template args from previous args, unify would complain when we
15570 try to deduce a template parameter for the same argument, even though
15571 there isn't really a conflict. */
15578 /* First make sure we didn't deduce anything that conflicts with
15579 explicitly specified args. */
15581 {
15588 /* Since we're unifying against ourselves, we will fill in
15589 template args used in the function parm list with our own
15590 template parms. Discard them. */
15594 }
15597 {
15602 }
15605 }
15607 /* PARM is a template class (perhaps with unbound template
15608 parameters). ARG is a fully instantiated type. If ARG can be
15609 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15610 TARGS are as for unify. */
15612 static tree
15615 {
15616 tree copy_of_targs;
15623 /* We need to make a new template argument vector for the call to
15624 unify. If we used TARGS, we'd clutter it up with the result of
15625 the attempted unification, even if this class didn't work out.
15626 We also don't want to commit ourselves to all the unifications
15627 we've already done, since unification is supposed to be done on
15628 an argument-by-argument basis. In other words, consider the
15629 following pathological case:
15631 template <int I, int J, int K>
15632 struct S {};
15634 template <int I, int J>
15635 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15637 template <int I, int J, int K>
15638 void f(S<I, J, K>, S<I, I, I>);
15640 void g() {
15641 S<0, 0, 0> s0;
15642 S<0, 1, 2> s2;
15644 f(s0, s2);
15645 }
15647 Now, by the time we consider the unification involving `s2', we
15648 already know that we must have `f<0, 0, 0>'. But, even though
15649 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15650 because there are two ways to unify base classes of S<0, 1, 2>
15651 with S<I, I, I>. If we kept the already deduced knowledge, we
15652 would reject the possibility I=1. */
15655 /* If unification failed, we're done. */
15661 }
15663 /* Given a template type PARM and a class type ARG, find the unique
15664 base type in ARG that is an instance of PARM. We do not examine
15665 ARG itself; only its base-classes. If there is not exactly one
15666 appropriate base class, return NULL_TREE. PARM may be the type of
15667 a partial specialization, as well as a plain template type. Used
15668 by unify. */
15670 static enum template_base_result
15673 {
15675 tree binfo;
15681 {
15682 /* The type could not be completed. */
15685 }
15687 /* Walk in inheritance graph order. The search order is not
15688 important, and this avoids multiple walks of virtual bases. */
15690 {
15695 {
15696 /* If there is more than one satisfactory baseclass, then:
15698 [temp.deduct.call]
15700 If they yield more than one possible deduced A, the type
15701 deduction fails.
15703 applies. */
15705 {
15708 }
15711 }
15712 }
15716 }
15718 /* Returns the level of DECL, which declares a template parameter. */
15720 static int
15722 {
15724 {
15734 }
15736 }
15738 /* Decide whether ARG can be unified with PARM, considering only the
15739 cv-qualifiers of each type, given STRICT as documented for unify.
15740 Returns nonzero iff the unification is OK on that basis. */
15742 static int
15744 {
15750 {
15751 /* Although a CVR qualifier is ignored when being applied to a
15752 substituted template parameter ([8.3.2]/1 for example), that
15753 does not allow us to unify "const T" with "int&" because both
15754 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15755 It is ok when we're allowing additional CV qualifiers
15756 at the outer level [14.8.2.1]/3,1st bullet. */
15766 }
15777 }
15779 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15780 void
15782 {
15786 {
15789 }
15790 else
15791 {
15794 }
15795 }
15797 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15798 do { \
15799 if (unify (TP, TA, P, A, S, EP)) \
15800 return 1; \
15801 } while (0);
15803 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15804 expansion at the end of PACKED_PARMS. Returns 0 if the type
15805 deduction succeeds, 1 otherwise. STRICT is the same as in
15806 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15807 call argument list. We'll need to adjust the arguments to make them
15808 types. SUBR tells us if this is from a recursive call to
15809 type_unification_real, or for comparing two template argument
15810 lists. */
15812 static int
15816 {
15817 tree parm
15824 /* Determine the parameter packs we will be deducing from the
15825 pattern, and record their current deductions. */
15828 {
15832 /* Determine the index and level of this parameter pack. */
15835 /* Keep track of the parameter packs and their corresponding
15836 argument packs. */
15839 }
15841 /* Loop through all of the arguments that have not yet been
15842 unified and unify each with the pattern. */
15844 {
15845 tree parm;
15849 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15850 or the element of its argument pack at the current index if
15851 this argument was explicitly specified. */
15853 {
15862 {
15865 }
15867 }
15869 /* If we had explicit template arguments, substitute them into the
15870 pattern before deduction. */
15872 {
15873 /* Some arguments might still be unspecified or dependent. */
15881 NULL_TREE);
15886 }
15887 else
15890 /* Unify the pattern with the current argument. */
15895 /* For each parameter pack, collect the deduced value. */
15897 {
15903 }
15904 }
15906 /* Verify that the results of unification with the parameter packs
15907 produce results consistent with what we've seen before, and make
15908 the deduced argument packs available. */
15910 {
15917 /* By default keep the original deduced argument pack.
15918 If necessary, more specific code is going to update the
15919 resulting deduced argument later down in this function. */
15923 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15924 actually deduce anything. */
15932 {
15933 /* If we had fewer function args than explicit template args,
15934 just use the explicits. */
15939 }
15942 {
15943 tree result;
15944 /* Build the deduced *_ARGUMENT_PACK. */
15946 {
15951 }
15952 else
15957 /* Note the deduced argument packs for this parameter
15958 pack. */
15960 }
15964 {
15965 /* We only had the explicitly-provided arguments before, but
15966 now we have a complete set of arguments. */
15972 }
15973 else
15974 {
15980 /* Inconsistent unification of this parameter pack. */
15982 bad_old_arg,
15983 bad_new_arg);
15984 }
15985 }
15988 }
15990 /* Deduce the value of template parameters. TPARMS is the (innermost)
15991 set of template parameters to a template. TARGS is the bindings
15992 for those template parameters, as determined thus far; TARGS may
15993 include template arguments for outer levels of template parameters
15994 as well. PARM is a parameter to a template function, or a
15995 subcomponent of that parameter; ARG is the corresponding argument.
15996 This function attempts to match PARM with ARG in a manner
15997 consistent with the existing assignments in TARGS. If more values
15998 are deduced, then TARGS is updated.
16000 Returns 0 if the type deduction succeeds, 1 otherwise. The
16001 parameter STRICT is a bitwise or of the following flags:
16003 UNIFY_ALLOW_NONE:
16004 Require an exact match between PARM and ARG.
16005 UNIFY_ALLOW_MORE_CV_QUAL:
16006 Allow the deduced ARG to be more cv-qualified (by qualification
16007 conversion) than ARG.
16008 UNIFY_ALLOW_LESS_CV_QUAL:
16009 Allow the deduced ARG to be less cv-qualified than ARG.
16010 UNIFY_ALLOW_DERIVED:
16011 Allow the deduced ARG to be a template base class of ARG,
16012 or a pointer to a template base class of the type pointed to by
16013 ARG.
16014 UNIFY_ALLOW_INTEGER:
16015 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16016 case for more information.
16017 UNIFY_ALLOW_OUTER_LEVEL:
16018 This is the outermost level of a deduction. Used to determine validity
16019 of qualification conversions. A valid qualification conversion must
16020 have const qualified pointers leading up to the inner type which
16021 requires additional CV quals, except at the outer level, where const
16022 is not required [conv.qual]. It would be normal to set this flag in
16023 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16024 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16025 This is the outermost level of a deduction, and PARM can be more CV
16026 qualified at this point.
16027 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16028 This is the outermost level of a deduction, and PARM can be less CV
16029 qualified at this point. */
16031 static int
16034 {
16036 tree targ;
16037 tree tparm;
16040 /* I don't think this will do the right thing with respect to types.
16041 But the only case I've seen it in so far has been array bounds, where
16042 signedness is the only information lost, and I think that will be
16043 okay. */
16051 /* We can't deduce anything from this, but we might get all the
16052 template args from other function args. */
16055 /* If PARM uses template parameters, then we can't bail out here,
16056 even if ARG == PARM, since we won't record unifications for the
16057 template parameters. We might need them if we're trying to
16058 figure out which of two things is more specialized. */
16062 /* Handle init lists early, so the rest of the function can assume
16063 we're dealing with a type. */
16065 {
16070 /* Replace T with std::initializer_list<T> for deduction. */
16076 /* We can only deduce from an initializer list argument if the
16077 parameter is std::initializer_list; otherwise this is a
16078 non-deduced context. */
16084 {
16091 {
16093 /* It should only be possible to get here for a call. */
16095 elt_strict |= maybe_adjust_types_for_deduction
16098 }
16101 explain_p);
16102 }
16104 /* If the std::initializer_list<T> deduction worked, replace the
16105 deduced A with std::initializer_list<A>. */
16107 {
16112 }
16114 }
16116 /* Immediately reject some pairs that won't unify because of
16117 cv-qualification mismatches. */
16120 /* It is the elements of the array which hold the cv quals of an array
16121 type, and the elements might be template type parms. We'll check
16122 when we recurse. */
16124 /* We check the cv-qualifiers when unifying with template type
16125 parameters below. We want to allow ARG `const T' to unify with
16126 PARM `T' for example, when computing which of two templates
16127 is more specialized, for example. */
16141 {
16145 /* In a type which contains a nested-name-specifier, template
16146 argument values cannot be deduced for template parameters used
16147 within the nested-name-specifier. */
16159 /* The PARM is not one we're trying to unify. Just check
16160 to see if it matches ARG. */
16161 {
16166 else
16168 }
16175 /* Check for mixed types and values. */
16183 {
16184 /* ARG must be constructed from a template class or a template
16185 template parameter. */
16190 {
16194 tree parm_parms
16195 = DECL_INNERMOST_TEMPLATE_PARMS
16200 /* The resolution to DR150 makes clear that default
16201 arguments for an N-argument may not be used to bind T
16202 to a template template parameter with fewer than N
16203 parameters. It is not safe to permit the binding of
16204 default arguments as an extension, as that may change
16205 the meaning of a conforming program. Consider:
16207 struct Dense { static const unsigned int dim = 1; };
16209 template <template <typename> class View,
16210 typename Block>
16211 void operator+(float, View<Block> const&);
16213 template <typename Block,
16214 unsigned int Dim = Block::dim>
16215 struct Lvalue_proxy { operator float() const; };
16217 void
16218 test_1d (void) {
16219 Lvalue_proxy<Dense> p;
16220 float b;
16221 b + p;
16222 }
16224 Here, if Lvalue_proxy is permitted to bind to View, then
16225 the global operator+ will be used; if they are not, the
16226 Lvalue_proxy will be converted to float. */
16228 full_argvec,
16230 (explain_p
16231 ? tf_warning_or_error
16238 /* Deduce arguments T, i from TT<T> or TT<i>.
16239 We check each element of PARMVEC and ARGVEC individually
16240 rather than the whole TREE_VEC since they can have
16241 different number of elements. */
16248 /* Check if the parameters end in a pack, making them
16249 variadic. */
16259 {
16264 }
16269 DEDUCE_EXACT,
16272 }
16275 /* Fall through to deduce template name. */
16276 }
16280 {
16281 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16283 /* Simple cases: Value already set, does match or doesn't. */
16288 }
16289 else
16290 {
16291 /* If PARM is `const T' and ARG is only `int', we don't have
16292 a match unless we are allowing additional qualification.
16293 If ARG is `const int' and PARM is just `T' that's OK;
16294 that binds `const int' to `T'. */
16299 /* Consider the case where ARG is `const volatile int' and
16300 PARM is `const T'. Then, T should be `volatile int'. */
16301 arg = cp_build_qualified_type_real
16306 /* Simple cases: Value already set, does match or doesn't. */
16312 /* Make sure that ARG is not a variable-sized array. (Note
16313 that were talking about variable-sized arrays (like
16314 `int[n]'), rather than arrays of unknown size (like
16315 `int[]').) We'll get very confused by such a type since
16316 the bound of the array is not constant, and therefore
16317 not mangleable. Besides, such types are not allowed in
16318 ISO C++, so we can do as we please here. We do allow
16319 them for 'auto' deduction, since that isn't ABI-exposed. */
16323 /* Strip typedefs as in convert_template_argument. */
16325 }
16327 /* If ARG is a parameter pack or an expansion, we cannot unify
16328 against it unless PARM is also a parameter pack. */
16333 /* If the argument deduction results is a METHOD_TYPE,
16334 then there is a problem.
16335 METHOD_TYPE doesn't map to any real C++ type the result of
16336 the deduction can not be of that type. */
16350 {
16351 /* The PARM is not one we're trying to unify. Just check
16352 to see if it matches ARG. */
16358 }
16364 {
16369 }
16371 /* [temp.deduct.type] If, in the declaration of a function template
16372 with a non-type template-parameter, the non-type
16373 template-parameter is used in an expression in the function
16374 parameter-list and, if the corresponding template-argument is
16375 deduced, the template-argument type shall match the type of the
16376 template-parameter exactly, except that a template-argument
16377 deduced from an array bound may be of any integral type.
16378 The non-type parameter might use already deduced type parameters. */
16381 /* Template-parameter dependent expression. Just accept it for now.
16382 It will later be processed in convert_template_argument. */
16383 ;
16389 /* Convert the ARG to the type of PARM; the deduced non-type
16390 template argument must exactly match the types of the
16391 corresponding parameter. */
16394 /* We haven't deduced the type of this parameter yet. Try again
16395 later. */
16397 else
16400 /* If ARG is a parameter pack or an expansion, we cannot unify
16401 against it unless PARM is also a parameter pack. */
16411 {
16412 /* A pointer-to-member constant can be unified only with
16413 another constant. */
16417 /* Just unify the class member. It would be useless (and possibly
16418 wrong, depending on the strict flags) to unify also
16419 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16420 arg refer to the same variable, even if through different
16421 classes. For instance:
16423 struct A { int x; };
16424 struct B : A { };
16426 Unification of &A::x and &B::x must succeed. */
16429 }
16432 {
16436 /* [temp.deduct.call]
16438 A can be another pointer or pointer to member type that can
16439 be converted to the deduced A via a qualification
16440 conversion (_conv.qual_).
16442 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16443 This will allow for additional cv-qualification of the
16444 pointed-to types if appropriate. */
16447 /* The derived-to-base conversion only persists through one
16448 level of pointers. */
16453 }
16468 {
16469 tree parm_max;
16470 tree arg_max;
16474 /* Our representation of array types uses "N - 1" as the
16475 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16476 not an integer constant. We cannot unify arbitrarily
16477 complex expressions, so we eliminate the MINUS_EXPRs
16478 here. */
16482 {
16485 }
16489 {
16490 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16491 trying to unify the type of a variable with the type
16492 of a template parameter. For example:
16494 template <unsigned int N>
16495 void f (char (&) [N]);
16496 int g();
16497 void h(int i) {
16498 char a[g(i)];
16499 f(a);
16500 }
16502 Here, the type of the ARG will be "int [g(i)]", and
16503 may be a SAVE_EXPR, etc. */
16507 }
16509 /* If only one of the bounds used a MINUS_EXPR, compensate
16510 by adding one to the other bound. */
16513 integer_type_node,
16514 parm_max,
16515 integer_one_node);
16518 integer_type_node,
16519 arg_max,
16520 integer_one_node);
16524 }
16539 /* We have already checked cv-qualification at the top of the
16540 function. */
16544 /* As far as unification is concerned, this wins. Later checks
16545 will invalidate it if necessary. */
16548 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16549 /* Type INTEGER_CST can come from ordinary constant template args. */
16561 {
16571 /* Check for pack expansions in the parameters. */
16573 {
16575 {
16577 /* We can unify against something with a trailing
16578 parameter pack. */
16580 else
16581 /* [temp.deduct.type]/9: If the template argument list of
16582 P contains a pack expansion that is not the last
16583 template argument, the entire template argument list
16584 is a non-deduced context. */
16586 }
16587 }
16589 /* If we don't have enough arguments to satisfy the parameters
16590 (not counting the pack expression at the end), or we have
16591 too many arguments for a parameter list that doesn't end in
16592 a pack expression, we can't unify. */
16598 /* Unify all of the parameters that precede the (optional)
16599 pack expression. */
16601 {
16606 }
16609 DEDUCE_EXACT,
16612 }
16620 {
16628 }
16631 {
16635 {
16636 /* First, we try to unify the PARM and ARG directly. */
16641 {
16642 /* Fallback to the special case allowed in
16643 [temp.deduct.call]:
16645 If P is a class, and P has the form
16646 template-id, then A can be a derived class of
16647 the deduced A. Likewise, if P is a pointer to
16648 a class of the form template-id, A can be a
16649 pointer to a derived class pointed to by the
16650 deduced A. */
16657 }
16658 }
16662 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16663 Then, we should unify `int' and `U'. */
16665 else
16666 /* There's no chance of unification succeeding. */
16671 }
16678 {
16681 tree a;
16687 /* CV qualifications for methods can never be deduced, they must
16688 match exactly. We need to check them explicitly here,
16689 because type_unification_real treats them as any other
16690 cv-qualified parameter. */
16692 && (!check_cv_quals_for_unify
16712 }
16715 /* Unify a pointer to member with a pointer to member function, which
16716 deduces the type of the member as a function type. */
16718 {
16719 tree method_type;
16720 tree fntype;
16722 /* Check top-level cv qualifiers */
16730 /* Determine the type of the function we are unifying against. */
16732 fntype =
16736 /* Extract the cv-qualifiers of the member function from the
16737 implicit object parameter and place them on the function
16738 type to be restored later. */
16741 }
16760 /* Matched cases are handled by the ARG == PARM test above. */
16764 /* A non-type template parameter that is a variable should be a
16765 an integral constant, in which case, it whould have been
16766 folded into its (constant) value. So we should not be getting
16767 a variable here. */
16778 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16779 or UNDERLYING_TYPE nodes. */
16783 /* Unification fails if we hit an error node. */
16787 /* An unresolved overload is a nondeduced context. */
16792 /* We must be looking at an expression. This can happen with
16793 something like:
16795 template <int I>
16796 void foo(S<I>, S<I + 2>);
16798 This is a "nondeduced context":
16800 [deduct.type]
16802 The nondeduced contexts are:
16804 --A type that is a template-id in which one or more of
16805 the template-arguments is an expression that references
16806 a template-parameter.
16808 In these cases, we assume deduction succeeded, but don't
16809 actually infer any unifications. */
16814 else
16816 }
16817 }
16818 #undef RECUR_AND_CHECK_FAILURE
16819 \f
16820 /* Note that DECL can be defined in this translation unit, if
16821 required. */
16823 static void
16825 {
16826 tree clone;
16830 }
16832 /* Called if RESULT is explicitly instantiated, or is a member of an
16833 explicitly instantiated class. */
16835 void
16837 {
16840 /* If this entity has already been written out, it's too late to
16841 make any modifications. */
16846 /* The TREE_PUBLIC flag for function declarations will have been
16847 set correctly by tsubst. */
16850 /* This might have been set by an earlier implicit instantiation. */
16855 else
16856 {
16858 /* Always make artificials weak. */
16861 /* For WIN32 we also want to put explicit instantiations in
16862 linkonce sections. */
16865 }
16867 /* If EXTERN_P, then this function will not be emitted -- unless
16868 followed by an explicit instantiation, at which point its linkage
16869 will be adjusted. If !EXTERN_P, then this function will be
16870 emitted here. In neither circumstance do we want
16871 import_export_decl to adjust the linkage. */
16873 }
16875 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16876 important template arguments. If any are missing, we check whether
16877 they're important by using error_mark_node for substituting into any
16878 args that were used for partial ordering (the ones between ARGS and END)
16879 and seeing if it bubbles up. */
16881 static bool
16883 {
16888 {
16891 }
16893 {
16897 }
16899 }
16901 /* Given two function templates PAT1 and PAT2, return:
16903 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16904 -1 if PAT2 is more specialized than PAT1.
16905 0 if neither is more specialized.
16907 LEN indicates the number of parameters we should consider
16908 (defaulted parameters should not be considered).
16910 The 1998 std underspecified function template partial ordering, and
16911 DR214 addresses the issue. We take pairs of arguments, one from
16912 each of the templates, and deduce them against each other. One of
16913 the templates will be more specialized if all the *other*
16914 template's arguments deduce against its arguments and at least one
16915 of its arguments *does* *not* deduce against the other template's
16916 corresponding argument. Deduction is done as for class templates.
16917 The arguments used in deduction have reference and top level cv
16918 qualifiers removed. Iff both arguments were originally reference
16919 types *and* deduction succeeds in both directions, the template
16920 with the more cv-qualified argument wins for that pairing (if
16921 neither is more cv-qualified, they both are equal). Unlike regular
16922 deduction, after all the arguments have been deduced in this way,
16923 we do *not* verify the deduced template argument values can be
16924 substituted into non-deduced contexts.
16926 The logic can be a bit confusing here, because we look at deduce1 and
16927 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16928 can find template arguments for pat1 to make arg1 look like arg2, that
16929 means that arg2 is at least as specialized as arg1. */
16931 int
16933 {
16946 /* Remove the this parameter from non-static member functions. If
16947 one is a non-static member function and the other is not a static
16948 member function, remove the first parameter from that function
16949 also. This situation occurs for operator functions where we
16950 locate both a member function (with this pointer) and non-member
16951 operator (with explicit first operand). */
16953 {
16958 }
16960 {
16963 {
16964 len--;
16966 }
16967 }
16969 /* If only one is a conversion operator, they are unordered. */
16973 /* Consider the return type for a conversion function */
16975 {
16978 len++;
16979 }
16981 processing_template_decl++;
16987 /* Stop when an ellipsis is seen. */
16989 {
16998 {
16999 /* When both arguments are pack expansions, we need only
17000 unify the patterns themselves. */
17004 /* This is the last comparison we need to do. */
17006 }
17009 {
17012 }
17015 {
17018 }
17024 {
17030 /* Setup the parameter vector, which contains only ARG1. */
17033 /* Setup the argument vector, which contains the remaining
17034 arguments. */
17043 /* We cannot deduce in the other direction, because ARG1 is
17044 a pack expansion but ARG2 is not. */
17046 }
17048 {
17054 /* Setup the parameter vector, which contains only ARG1. */
17057 /* Setup the argument vector, which contains the remaining
17058 arguments. */
17067 /* We cannot deduce in the other direction, because ARG2 is
17068 a pack expansion but ARG1 is not.*/
17070 }
17072 else
17073 {
17074 /* The normal case, where neither argument is a pack
17075 expansion. */
17082 }
17084 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17085 arg2, then arg2 is not as specialized as arg1. */
17091 /* "If, for a given type, deduction succeeds in both directions
17092 (i.e., the types are identical after the transformations above)
17093 and if the type from the argument template is more cv-qualified
17094 than the type from the parameter template (as described above)
17095 that type is considered to be more specialized than the other. If
17096 neither type is more cv-qualified than the other then neither type
17097 is more specialized than the other." */
17101 {
17106 }
17109 /* We've failed to deduce something in either direction.
17110 These must be unordered. */
17115 /* We have already processed all of the arguments in our
17116 handing of the pack expansion type. */
17121 }
17123 /* "In most cases, all template parameters must have values in order for
17124 deduction to succeed, but for partial ordering purposes a template
17125 parameter may remain without a value provided it is not used in the
17126 types being used for partial ordering."
17128 Thus, if we are missing any of the targs1 we need to substitute into
17129 origs1, then pat2 is not as specialized as pat1. This can happen when
17130 there is a nondeduced context. */
17136 processing_template_decl--;
17138 /* All things being equal, if the next argument is a pack expansion
17139 for one function but not for the other, prefer the
17140 non-variadic function. FIXME this is bogus; see c++/41958. */
17144 {
17147 }
17153 else
17155 }
17157 /* Determine which of two partial specializations of MAIN_TMPL is more
17158 specialized.
17160 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17161 to the first partial specialization. The TREE_VALUE is the
17162 innermost set of template parameters for the partial
17163 specialization. PAT2 is similar, but for the second template.
17165 Return 1 if the first partial specialization is more specialized;
17166 -1 if the second is more specialized; 0 if neither is more
17167 specialized.
17169 See [temp.class.order] for information about determining which of
17170 two templates is more specialized. */
17172 static int
17174 {
17175 tree targs;
17183 /* Just like what happens for functions, if we are ordering between
17184 different class template specializations, we may encounter dependent
17185 types in the arguments, and we need our dependency check functions
17186 to behave correctly. */
17192 {
17195 }
17201 {
17204 }
17207 /* In the case of a tie where at least one of the class templates
17208 has a parameter pack at the end, the template with the most
17209 non-packed parameters wins. */
17211 && any_deductions
17214 {
17220 /* We don't count the pack expansion at the end. */
17230 }
17233 }
17235 /* Return the template arguments that will produce the function signature
17236 DECL from the function template FN, with the explicit template
17237 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17238 also match. Return NULL_TREE if no satisfactory arguments could be
17239 found. */
17241 static tree
17243 {
17247 tree decl_arg_types;
17250 tree arg;
17254 /* Never do unification on the 'this' parameter. */
17274 }
17276 /* Return the innermost template arguments that, when applied to a partial
17277 specialization of MAIN_TMPL whose innermost template parameters are
17278 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17279 ARGS.
17281 For example, suppose we have:
17283 template <class T, class U> struct S {};
17284 template <class T> struct S<T*, int> {};
17286 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17287 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17288 int}. The resulting vector will be {double}, indicating that `T'
17289 is bound to `double'. */
17291 static tree
17293 {
17295 tree deduced_args;
17296 tree innermost_deduced_args;
17300 {
17304 innermost_deduced_args);
17305 }
17306 else
17319 /* Verify that nondeduced template arguments agree with the type
17320 obtained from argument deduction.
17322 For example:
17324 struct A { typedef int X; };
17325 template <class T, class U> struct C {};
17326 template <class T> struct C<T, typename T::X> {};
17328 Then with the instantiation `C<A, int>', we can deduce that
17329 `T' is `A' but unify () does not check whether `typename T::X'
17330 is `int'. */
17336 /* We only need to check the innermost arguments; the other
17337 arguments will always agree. */
17342 /* Now that we have bindings for all of the template arguments,
17343 ensure that the arguments deduced for the template template
17344 parameters have compatible template parameter lists. See the use
17345 of template_template_parm_bindings_ok_p in fn_type_unification
17346 for more information. */
17351 }
17353 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17354 Return the TREE_LIST node with the most specialized template, if
17355 any. If there is no most specialized template, the error_mark_node
17356 is returned.
17358 Note that this function does not look at, or modify, the
17359 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17360 returned is one of the elements of INSTANTIATIONS, callers may
17361 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17362 and retrieve it from the value returned. */
17364 tree
17366 {
17373 {
17379 fate--;
17384 fate++;
17389 {
17390 /* Equally specialized, move to next function. If there
17391 is no next function, nothing's most specialized. */
17396 }
17397 }
17400 /* Now verify that champ is better than everything earlier in the
17401 instantiation list. */
17409 {
17412 }
17414 processing_template_decl--;
17420 }
17422 /* If DECL is a specialization of some template, return the most
17423 general such template. Otherwise, returns NULL_TREE.
17425 For example, given:
17427 template <class T> struct S { template <class U> void f(U); };
17429 if TMPL is `template <class U> void S<int>::f(U)' this will return
17430 the full template. This function will not trace past partial
17431 specializations, however. For example, given in addition:
17433 template <class T> struct S<T*> { template <class U> void f(U); };
17435 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17436 `template <class T> template <class U> S<T*>::f(U)'. */
17438 tree
17440 {
17441 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17442 an immediate specialization. */
17444 {
17448 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17449 template friend. */
17454 }
17456 /* Look for more and more general templates. */
17458 {
17459 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17460 (See cp-tree.h for details.) */
17468 /* Stop if we run into an explicitly specialized class template. */
17475 }
17478 }
17480 /* Return the most specialized of the class template partial
17481 specializations of TMPL which can produce TYPE, a specialization of
17482 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17483 a _TYPE node corresponding to the partial specialization, while the
17484 TREE_PURPOSE is the set of template arguments that must be
17485 substituted into the TREE_TYPE in order to generate TYPE.
17487 If the choice of partial specialization is ambiguous, a diagnostic
17488 is issued, and the error_mark_node is returned. If there are no
17489 partial specializations of TMPL matching TYPE, then NULL_TREE is
17490 returned. */
17492 static tree
17494 {
17496 tree t;
17497 tree champ;
17500 tree args;
17506 /* For determining which partial specialization to use, only the
17507 innermost args are interesting. */
17509 {
17512 }
17515 {
17516 tree partial_spec_args;
17517 tree spec_args;
17525 {
17528 /* Discard the outer levels of args, and then substitute in the
17529 template args from the enclosing class. */
17531 partial_spec_args = tsubst_template_args
17534 /* PARMS already refers to just the innermost parms, but the
17535 template parms in partial_spec_args had their levels lowered
17536 by tsubst, so we need to do the same for the parm list. We
17537 can't just tsubst the TREE_VEC itself, as tsubst wants to
17538 treat a TREE_VEC as an argument vector. */
17544 }
17546 partial_spec_args =
17549 partial_spec_args),
17560 partial_spec_args,
17561 args);
17563 {
17568 }
17569 }
17579 {
17582 ;
17583 else
17584 {
17586 {
17589 {
17592 }
17593 }
17595 }
17596 }
17600 {
17603 {
17606 }
17607 }
17610 {
17618 {
17621 }
17624 }
17627 }
17629 /* Explicitly instantiate DECL. */
17631 void
17633 {
17638 /* An error occurred, for which grokdeclarator has already issued
17639 an appropriate message. */
17642 {
17645 }
17647 {
17648 /* There is an asymmetry here in the way VAR_DECLs and
17649 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17650 the latter, the DECL we get back will be marked as a
17651 template instantiation, and the appropriate
17652 DECL_TEMPLATE_INFO will be set up. This does not happen for
17653 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17654 should handle VAR_DECLs as it currently handles
17655 FUNCTION_DECLs. */
17657 {
17660 }
17663 {
17666 }
17668 {
17673 }
17674 }
17676 {
17679 }
17680 else
17683 /* Check for various error cases. Note that if the explicit
17684 instantiation is valid the RESULT will currently be marked as an
17685 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17686 until we get here. */
17689 {
17690 /* DR 259 [temp.spec].
17692 Both an explicit instantiation and a declaration of an explicit
17693 specialization shall not appear in a program unless the explicit
17694 instantiation follows a declaration of the explicit specialization.
17696 For a given set of template parameters, if an explicit
17697 instantiation of a template appears after a declaration of an
17698 explicit specialization for that template, the explicit
17699 instantiation has no effect. */
17701 }
17703 {
17704 /* [temp.spec]
17706 No program shall explicitly instantiate any template more
17707 than once.
17709 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17710 the first instantiation was `extern' and the second is not,
17711 and EXTERN_P for the opposite case. */
17714 /* If an "extern" explicit instantiation follows an ordinary
17715 explicit instantiation, the template is instantiated. */
17718 }
17720 {
17723 }
17725 {
17728 }
17731 ;
17733 {
17736 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17739 }
17740 else
17748 }
17750 static void
17752 {
17758 {
17761 }
17762 }
17764 /* Called from do_type_instantiation through binding_table_foreach to
17765 do recursive instantiation for the type bound in ENTRY. */
17766 static void
17768 {
17774 }
17776 /* Called from do_type_instantiation to instantiate a member
17777 (a member function or a static member variable) of an
17778 explicitly instantiated class template. */
17779 static void
17781 {
17786 }
17788 /* Perform an explicit instantiation of template class T. STORAGE, if
17789 non-null, is the RID for extern, inline or static. COMPLAIN is
17790 nonzero if this is called from the parser, zero if called recursively,
17791 since the standard is unclear (as detailed below). */
17793 void
17795 {
17805 {
17806 tree tmpl =
17810 else
17813 }
17818 {
17821 t);
17823 }
17826 {
17828 {
17830 {
17833 "ISO C++ 1998 forbids the use of %<extern%> on "
17835 }
17836 else
17838 "ISO C++ forbids the use of %qE"
17840 }
17848 else
17849 {
17851 storage);
17853 }
17854 }
17857 {
17858 /* DR 259 [temp.spec].
17860 Both an explicit instantiation and a declaration of an explicit
17861 specialization shall not appear in a program unless the explicit
17862 instantiation follows a declaration of the explicit specialization.
17864 For a given set of template parameters, if an explicit
17865 instantiation of a template appears after a declaration of an
17866 explicit specialization for that template, the explicit
17867 instantiation has no effect. */
17869 }
17871 {
17872 /* [temp.spec]
17874 No program shall explicitly instantiate any template more
17875 than once.
17877 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17878 instantiation was `extern'. If EXTERN_P then the second is.
17879 These cases are OK. */
17886 /* If we've already instantiated the template, just return now. */
17889 }
17897 {
17898 tree tmp;
17900 /* In contrast to implicit instantiation, where only the
17901 declarations, and not the definitions, of members are
17902 instantiated, we have here:
17904 [temp.explicit]
17906 The explicit instantiation of a class template specialization
17907 implies the instantiation of all of its members not
17908 previously explicitly specialized in the translation unit
17909 containing the explicit instantiation.
17911 Of course, we can't instantiate member template classes, since
17912 we don't have any arguments for them. Note that the standard
17913 is unclear on whether the instantiation of the members are
17914 *explicit* instantiations or not. However, the most natural
17915 interpretation is that it should be an explicit instantiation. */
17930 }
17931 }
17933 /* Given a function DECL, which is a specialization of TMPL, modify
17934 DECL to be a re-instantiation of TMPL with the same template
17935 arguments. TMPL should be the template into which tsubst'ing
17936 should occur for DECL, not the most general template.
17938 One reason for doing this is a scenario like this:
17940 template <class T>
17941 void f(const T&, int i);
17943 void g() { f(3, 7); }
17945 template <class T>
17946 void f(const T& t, const int i) { }
17948 Note that when the template is first instantiated, with
17949 instantiate_template, the resulting DECL will have no name for the
17950 first parameter, and the wrong type for the second. So, when we go
17951 to instantiate the DECL, we regenerate it. */
17953 static void
17955 {
17956 /* The arguments used to instantiate DECL, from the most general
17957 template. */
17958 tree args;
17959 tree code_pattern;
17964 /* Make sure that we can see identifiers, and compute access
17965 correctly. */
17969 {
17970 tree decl_parm;
17971 tree pattern_parm;
17972 tree specs;
17986 specs);
17988 /* Merge parameter declarations. */
17991 pattern_parm
17995 {
17996 tree parm_type;
17997 tree attributes;
18002 NULL_TREE);
18008 {
18011 }
18014 }
18015 /* Merge any parameters that match with the function parameter
18016 pack. */
18018 {
18020 tree expanded_types;
18021 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18022 the parameters in this function parameter pack. */
18027 {
18028 tree parm_type;
18029 tree attributes;
18032 /* Rename the parameter to include the index. */
18041 {
18044 }
18046 }
18047 }
18048 /* Merge additional specifiers from the CODE_PATTERN. */
18052 }
18054 {
18062 }
18063 else
18067 }
18069 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18070 substituted to get DECL. */
18072 tree
18074 {
18077 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18078 for the instantiation. This is not always the most general
18079 template. Consider, for example:
18081 template <class T>
18082 struct S { template <class U> void f();
18083 template <> void f<int>(); };
18085 and an instantiation of S<double>::f<int>. We want TD to be the
18086 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18088 more general template. */
18090 /* We must also deal with friend templates. Given:
18092 template <class T> struct S {
18093 template <class U> friend void f() {};
18094 };
18096 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18097 so far as the language is concerned, but that's still
18098 where we get the pattern for the instantiation from. On
18099 other hand, if the definition comes outside the class, say:
18101 template <class T> struct S {
18102 template <class U> friend void f();
18103 };
18104 template <class U> friend void f() {}
18106 we don't need to look any further. That's what the check for
18107 DECL_INITIAL is for. */
18111 {
18112 /* The present template, TD, should not be a definition. If it
18113 were a definition, we should be using it! Note that we
18114 cannot restructure the loop to just keep going until we find
18115 a template with a definition, since that might go too far if
18116 a specialization was declared, but not defined. */
18120 /* Fetch the more general template. */
18122 }
18125 }
18127 /* Returns true if we need to instantiate this template instance even if we
18128 know we aren't going to emit it.. */
18130 bool
18132 {
18133 /* We always instantiate inline functions so that we can inline them. An
18134 explicit instantiation declaration prohibits implicit instantiation of
18135 non-inline functions. With high levels of optimization, we would
18136 normally inline non-inline functions -- but we're not allowed to do
18137 that for "extern template" functions. Therefore, we check
18138 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18142 /* And we need to instantiate static data members so that
18143 their initializers are available in integral constant
18144 expressions. */
18147 }
18149 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18150 instantiate it now, modifying TREE_TYPE (fn). */
18152 void
18154 {
18168 {
18170 {
18183 }
18184 else
18186 }
18187 else
18188 {
18189 /* This is an implicitly declared function, so NOEX is a list of
18190 other functions to evaluate and merge. */
18191 tree elt;
18194 {
18196 tree subspec;
18200 }
18201 }
18206 {
18209 else
18211 }
18212 }
18214 /* Produce the definition of D, a _DECL generated from a template. If
18215 DEFER_OK is nonzero, then we don't have to actually do the
18216 instantiation now; we just have to do it sometime. Normally it is
18217 an error if this is an explicit instantiation but D is undefined.
18218 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18219 explicitly instantiated class template. */
18221 tree
18224 {
18226 tree gen_args;
18227 tree args;
18228 tree td;
18229 tree code_pattern;
18230 tree spec;
18231 tree gen_tmpl;
18235 tree fn_context;
18238 /* This function should only be used to instantiate templates for
18239 functions and static member variables. */
18243 /* Variables are never deferred; if instantiation is required, they
18244 are instantiated right away. That allows for better code in the
18245 case that an expression refers to the value of the variable --
18246 if the variable has a constant value the referring expression can
18247 take advantage of that fact. */
18252 /* Don't instantiate cloned functions. Instead, instantiate the
18253 functions they cloned. */
18261 /* D has already been instantiated or explicitly specialized, so
18262 there's nothing for us to do here.
18264 It might seem reasonable to check whether or not D is an explicit
18265 instantiation, and, if so, stop here. But when an explicit
18266 instantiation is deferred until the end of the compilation,
18267 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18268 the instantiation. */
18271 /* Check to see whether we know that this template will be
18272 instantiated in some other file, as with "extern template"
18273 extension. */
18276 /* In general, we do not instantiate such templates. */
18284 /* We should already have the extra args. */
18287 /* And what's in the hash table should match D. */
18291 /* This needs to happen before any tsubsting. */
18297 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18298 for the instantiation. */
18302 /* We should never be trying to instantiate a member of a class
18303 template or partial specialization. */
18308 /* In the case of a friend template whose definition is provided
18309 outside the class, we may have too many arguments. Drop the
18310 ones we don't need. The same is true for specializations. */
18311 args = get_innermost_template_args
18313 else
18319 else
18322 /* We may be in the middle of deferred access check. Disable it now. */
18325 /* Unless an explicit instantiation directive has already determined
18326 the linkage of D, remember that a definition is available for
18327 this entity. */
18337 /* If D is a member of an explicitly instantiated class template,
18338 and no definition is available, treat it like an implicit
18339 instantiation. */
18342 {
18343 /* Leave linkage flags alone on instantiations with anonymous
18344 visibility. */
18346 {
18349 }
18351 }
18356 /* Defer all other templates, unless we have been explicitly
18357 forbidden from doing so. */
18359 template. */
18360 ! pattern_defined
18361 /* If it's OK to postpone instantiation, do so. */
18362 || defer_ok
18363 /* If this is a static data member that will be defined
18364 elsewhere, we don't want to instantiate the entire data
18365 member, but we do want to instantiate the initializer so that
18366 we can substitute that elsewhere. */
18368 {
18369 /* The definition of the static data member is now required so
18370 we must substitute the initializer. */
18374 {
18375 tree ns;
18376 tree init;
18383 args,
18386 /* Make sure the initializer is still constant, in case of
18387 circular dependency (template/instantiate6.C). */
18388 const_init
18392 LOOKUP_ONLYCONVERTING);
18395 }
18397 /* We restore the source position here because it's used by
18398 add_pending_template. */
18404 /* [temp.explicit]
18406 The definition of a non-exported function template, a
18407 non-exported member function template, or a non-exported
18408 member function or static data member of a class template
18409 shall be present in every translation unit in which it is
18410 explicitly instantiated. */
18414 /* If we're in unevaluated context, we just wanted to get the
18415 constant value; this isn't an odr use, so don't queue
18416 a full instantiation. */
18419 /* ??? Historically, we have instantiated inline functions, even
18420 when marked as "extern template". */
18424 }
18425 /* Tell the repository that D is available in this translation unit
18426 -- and see if it is supposed to be instantiated here. */
18428 {
18429 /* In a PCH file, despite the fact that the repository hasn't
18430 requested instantiation in the PCH it is still possible that
18431 an instantiation will be required in a file that includes the
18432 PCH. */
18435 /* Instantiate inline functions so that the inliner can do its
18436 job, even though we'll not be emitting a copy of this
18437 function. */
18440 }
18449 /* Mark D as instantiated so that recursive calls to
18450 instantiate_decl do not try to instantiate it again. */
18453 /* Regenerate the declaration in case the template has been modified
18454 by a subsequent redeclaration. */
18457 /* We already set the file and line above. Reset them now in case
18458 they changed as a result of calling regenerate_decl_from_template. */
18462 {
18463 tree init;
18466 /* Clear out DECL_RTL; whatever was there before may not be right
18467 since we've reset the type of the declaration. */
18471 /* The initializer is placed in DECL_INITIAL by
18472 regenerate_decl_from_template so we don't need to
18473 push/pop_access_scope again here. Pull it out so that
18474 cp_finish_decl can process it. */
18479 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18480 initializer. That function will defer actual emission until
18481 we have a chance to determine linkage. */
18484 /* Enter the scope of D so that access-checking works correctly. */
18489 }
18493 {
18495 tree subst_decl;
18496 tree tmpl_parm;
18497 tree spec_parm;
18499 /* Save away the current list, in case we are instantiating one
18500 template from within the body of another. */
18503 /* Set up the list of local specializations. */
18506 /* Set up context. */
18509 /* Some typedefs referenced from within the template code need to be
18510 access checked at template instantiation time, i.e now. These
18511 types were added to the template at parsing time. Let's get those
18512 and perform the access checks then. */
18514 gen_args);
18516 /* Create substitution entries for the parameters. */
18521 {
18525 }
18527 {
18529 {
18532 }
18533 else
18534 {
18535 /* Register the (value) argument pack as a specialization of
18536 TMPL_PARM, then move on. */
18539 }
18540 }
18543 /* Substitute into the body of the function. */
18548 /* Set the current input_location to the end of the function
18549 so that finish_function knows where we are. */
18552 /* We don't need the local specializations any more. */
18556 /* Finish the function. */
18559 }
18561 /* We're not deferring instantiation any more. */
18569 out:
18577 }
18579 /* Run through the list of templates that we wish we could
18580 instantiate, and instantiate any we can. RETRIES is the
18581 number of times we retry pending template instantiation. */
18583 void
18585 {
18589 /* Instantiating templates may trigger vtable generation. This in turn
18590 may require further template instantiations. We place a limit here
18591 to avoid infinite loop. */
18593 {
18597 " instantiating %q+D, possibly from virtual table generation"
18601 /* Pretend that we defined it. */
18604 }
18606 do
18607 {
18612 {
18617 {
18618 tree fn;
18621 {
18625 fn;
18633 }
18636 }
18637 else
18638 {
18641 {
18642 instantiation
18648 }
18652 }
18655 /* If INSTANTIATION has been instantiated, then we don't
18656 need to consider it again in the future. */
18658 else
18659 {
18662 }
18665 }
18667 }
18671 }
18673 /* Substitute ARGVEC into T, which is a list of initializers for
18674 either base class or a non-static data member. The TREE_PURPOSEs
18675 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18676 instantiate_decl. */
18678 static tree
18680 {
18684 {
18685 tree decl;
18686 tree init;
18692 {
18693 tree expr;
18694 tree arg;
18696 /* Expand the base class expansion type into separate base
18697 classes. */
18699 tf_warning_or_error,
18700 NULL_TREE);
18704 /* We'll be building separate TREE_LISTs of arguments for
18705 each base. */
18711 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18712 expand each argument in the TREE_VALUE of t. */
18719 /* VOID_TYPE_NODE is used to indicate
18720 value-initialization. */
18721 {
18724 }
18725 else
18726 {
18727 /* Substitute parameter packs into each argument in the
18728 TREE_LIST. */
18731 {
18732 tree expanded_exprs;
18734 /* Expand the argument. */
18736 expanded_exprs
18738 tf_warning_or_error,
18739 NULL_TREE);
18743 /* Prepend each of the expanded expressions to the
18744 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18746 {
18751 }
18752 }
18755 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18756 since we built them backwards. */
18758 {
18761 }
18762 }
18763 }
18766 {
18768 {
18772 }
18773 else
18774 {
18775 tree tmp;
18790 /* If we had an initializer but it instantiated to nothing,
18791 value-initialize the object. This will only occur when
18792 the initializer was a pack expansion where the parameter
18793 packs used in that expansion were of length zero. */
18796 }
18799 {
18803 }
18804 }
18805 }
18807 }
18809 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18811 static void
18813 {
18818 else
18820 }
18822 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18823 is the instantiation (which should have been created with
18824 start_enum) and ARGS are the template arguments to use. */
18826 static void
18828 {
18829 tree e;
18835 {
18836 tree value;
18837 tree decl;
18840 /* Note that in a template enum, the TREE_VALUE is the
18841 CONST_DECL, not the corresponding INTEGER_CST. */
18846 /* Give this enumeration constant the correct access. */
18849 /* Actually build the enumerator itself. */
18850 build_enumerator
18852 }
18862 }
18864 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18865 its type -- but without substituting the innermost set of template
18866 arguments. So, innermost set of template parameters will appear in
18867 the type. */
18869 tree
18871 {
18872 tree fn_type;
18873 tree tmpl;
18874 tree targs;
18875 tree tparms;
18883 /* There should be as many levels of arguments as there are levels
18884 of parameters. */
18890 /* No substitution is necessary. */
18891 ;
18892 else
18893 {
18895 tree partial_args;
18897 /* Replace the innermost level of the TARGS with NULL_TREEs to
18898 let tsubst know not to substitute for those parameters. */
18907 /* Make sure that we can see identifiers, and compute access
18908 correctly. */
18912 /* Now, do the (partial) substitution to figure out the
18913 appropriate function type. */
18917 /* Substitute into the template parameters to obtain the real
18918 innermost set of parameters. This step is important if the
18919 innermost set of template parameters contains value
18920 parameters whose types depend on outer template parameters. */
18925 }
18928 }
18930 /* Return truthvalue if we're processing a template different from
18931 the last one involved in diagnostics. */
18932 int
18934 {
18936 }
18938 /* Remember current template involved in diagnostics. */
18939 void
18941 {
18943 }
18947 {
18949 }
18951 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18952 type. Return zero for ok, nonzero for disallowed. Issue error and
18953 warning messages under control of COMPLAIN. */
18955 static int
18957 {
18974 {
18977 else
18979 type);
18980 }
18982 }
18984 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18985 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18987 static bool
18989 {
18990 tree scope;
18992 /* [temp.dep.type]
18994 A type is dependent if it is:
18996 -- a template parameter. Template template parameters are types
18997 for us (since TYPE_P holds true for them) so we handle
18998 them here. */
19002 /* -- a qualified-id with a nested-name-specifier which contains a
19003 class-name that names a dependent type or whose unqualified-id
19004 names a dependent type. */
19007 /* -- a cv-qualified type where the cv-unqualified type is
19008 dependent. */
19010 /* -- a compound type constructed from any dependent type. */
19020 {
19021 tree arg_type;
19026 arg_type;
19031 }
19032 /* -- an array type constructed from any dependent type or whose
19033 size is specified by a constant expression that is
19034 value-dependent.
19036 We checked for type- and value-dependence of the bounds in
19037 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19039 {
19044 }
19046 /* -- a template-id in which either the template name is a template
19047 parameter ... */
19050 /* ... or any of the template arguments is a dependent type or
19051 an expression that is type-dependent or value-dependent. */
19053 && (any_dependent_template_arguments_p
19057 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19058 dependent; if the argument of the `typeof' expression is not
19059 type-dependent, then it should already been have resolved. */
19065 /* A template argument pack is dependent if any of its packed
19066 arguments are. */
19068 {
19074 }
19076 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19077 be template parameters. */
19081 /* The standard does not specifically mention types that are local
19082 to template functions or local classes, but they should be
19083 considered dependent too. For example:
19085 template <int I> void f() {
19086 enum E { a = I };
19087 S<sizeof (E)> s;
19088 }
19090 The size of `E' cannot be known until the value of `I' has been
19091 determined. Therefore, `E' must be considered dependent. */
19095 /* Don't use type_dependent_expression_p here, as it can lead
19096 to infinite recursion trying to determine whether a lambda
19097 nested in a lambda is dependent (c++/47687). */
19101 && (any_dependent_template_arguments_p
19105 /* Other types are non-dependent. */
19107 }
19109 /* Returns TRUE if TYPE is dependent, in the sense of
19110 [temp.dep.type]. Note that a NULL type is considered dependent. */
19112 bool
19114 {
19115 /* If there are no template parameters in scope, then there can't be
19116 any dependent types. */
19118 {
19119 /* If we are not processing a template, then nobody should be
19120 providing us with a dependent type. */
19124 }
19126 /* If the type is NULL, we have not computed a type for the entity
19127 in question; in that case, the type is dependent. */
19131 /* Erroneous types can be considered non-dependent. */
19135 /* If we have not already computed the appropriate value for TYPE,
19136 do so now. */
19138 {
19141 }
19144 }
19146 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19147 lookup. In other words, a dependent type that is not the current
19148 instantiation. */
19150 bool
19152 {
19155 }
19157 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19158 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19159 expression. */
19161 /* Note that this predicate is not appropriate for general expressions;
19162 only constant expressions (that satisfy potential_constant_expression)
19163 can be tested for value dependence. */
19165 bool
19167 {
19171 /* A name declared with a dependent type. */
19176 {
19178 /* A name that has not been looked up -- must be dependent. */
19182 /* A non-type template parm. */
19186 /* A non-type template parm. */
19192 /* A constant with literal type and is initialized
19193 with an expression that is value-dependent. */
19205 /* These expressions are value-dependent if the type to which
19206 the cast occurs is dependent or the expression being casted
19207 is value-dependent. */
19208 {
19214 /* A functional cast has a list of operands. */
19217 {
19218 /* If there are no operands, it must be an expression such
19219 as "int()". This should not happen for aggregate types
19220 because it would form non-constant expressions. */
19225 }
19231 }
19236 /* A `sizeof' expression is value-dependent if the operand is
19237 type-dependent or is a pack expansion. */
19246 /* An 'encode' expression is value-dependent if the operand is
19247 type-dependent. */
19256 /* instantiation_dependent_r treats this as dependent so that we
19257 check access at instantiation time, and all instantiation-dependent
19258 expressions should also be considered value-dependent. */
19266 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19267 is value-dependent. */
19268 {
19277 }
19280 {
19284 }
19295 {
19299 }
19302 {
19309 {
19311 /* In a call to a constexpr member function, look through the
19312 implicit ADDR_EXPR on the object argument so that it doesn't
19313 cause the call to be considered value-dependent. We also
19314 look through it in potential_constant_expression. */
19321 }
19323 }
19326 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19327 type-dependent. */
19331 {
19333 tree val;
19338 }
19341 /* Treat a GNU statement expression as dependent to avoid crashing
19342 under fold_non_dependent_expr; it can't be constant. */
19346 /* A constant expression is value-dependent if any subexpression is
19347 value-dependent. */
19349 {
19356 {
19360 {
19363 /* In some cases, some of the operands may be missing.l
19364 (For example, in the case of PREDECREMENT_EXPR, the
19365 amount to increment by may be missing.) That doesn't
19366 make the expression dependent. */
19369 }
19370 }
19374 }
19376 }
19378 /* The expression is not value-dependent. */
19380 }
19382 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19383 [temp.dep.expr]. Note that an expression with no type is
19384 considered dependent. Other parts of the compiler arrange for an
19385 expression with type-dependent subexpressions to have no type, so
19386 this function doesn't have to be fully recursive. */
19388 bool
19390 {
19397 /* An unresolved name is always dependent. */
19402 /* Some expression forms are never type-dependent. */
19415 /* The types of these expressions depends only on the type to which
19416 the cast occurs. */
19425 /* The types of these expressions depends only on the type created
19426 by the expression. */
19429 {
19430 /* For NEW_EXPR tree nodes created inside a template, either
19431 the object type itself or a TREE_LIST may appear as the
19432 operand 1. */
19435 /* This is an array type. We need to check array dimensions
19436 as well. */
19438 || value_dependent_expression_p
19440 else
19442 }
19445 {
19449 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19450 contains an identifier associated by name lookup with one or more
19451 declarations declared with a dependent type, or...a
19452 nested-name-specifier or qualified-id that names a member of an
19453 unknown specialization. */
19456 }
19461 && (any_dependent_template_arguments_p
19473 {
19474 tree elt;
19478 {
19481 }
19483 }
19485 /* A static data member of the current instantiation with incomplete
19486 array type is type-dependent, as the definition and specializations
19487 can have different bounds. */
19495 {
19500 {
19506 }
19507 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19515 {
19520 }
19525 {
19529 }
19531 }
19536 }
19538 /* walk_tree callback function for instantiation_dependent_expression_p,
19539 below. Returns non-zero if a dependent subexpression is found. */
19541 static tree
19544 {
19546 {
19547 /* We don't have to worry about decltype currently because decltype
19548 of an instantiation-dependent expr is a dependent type. This
19549 might change depending on the resolution of DR 1172. */
19552 }
19555 {
19556 /* Don't treat an argument list as dependent just because it has no
19557 TREE_TYPE. */
19565 /* Handle expressions with type operands. */
19571 {
19574 {
19579 else
19580 {
19583 }
19584 }
19586 }
19590 /* In a template, finish_class_member_access_expr creates a
19591 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
19592 type-dependent, so that we can check access control at
19593 instantiation time (PR 42277). See also Core issue 1273. */
19598 /* Similarly, finish_qualified_id_expr builds up a SCOPE_REF in a
19599 template so that we can check access at instantiation time even
19600 though we know which member it resolves to. */
19605 }
19609 else
19611 }
19613 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
19614 sense defined by the ABI:
19616 "An expression is instantiation-dependent if it is type-dependent
19617 or value-dependent, or it has a subexpression that is type-dependent
19618 or value-dependent." */
19620 bool
19622 {
19623 tree result;
19634 }
19636 /* Like type_dependent_expression_p, but it also works while not processing
19637 a template definition, i.e. during substitution or mangling. */
19639 bool
19641 {
19647 }
19649 /* Returns TRUE if ARGS contains a type-dependent expression. */
19651 bool
19653 {
19655 tree arg;
19658 {
19661 }
19663 }
19665 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19666 expressions) contains any type-dependent expressions. */
19668 bool
19670 {
19676 }
19678 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19679 expressions) contains any value-dependent expressions. */
19681 bool
19683 {
19689 }
19691 /* Returns TRUE if the ARG (a template argument) is dependent. */
19693 bool
19695 {
19699 /* Assume a template argument that was wrongly written by the user
19700 is dependent. This is consistent with what
19701 any_dependent_template_arguments_p [that calls this function]
19702 does. */
19713 {
19717 {
19720 }
19723 }
19726 else
19729 }
19731 /* Returns true if ARGS (a collection of template arguments) contains
19732 any types that require structural equality testing. */
19734 bool
19736 {
19746 {
19749 {
19755 {
19756 /* Look inside the argument pack. */
19759 }
19762 {
19776 }
19777 }
19778 }
19781 }
19783 /* Returns true if ARGS (a collection of template arguments) contains
19784 any dependent arguments. */
19786 bool
19788 {
19798 {
19803 }
19806 }
19808 /* Returns TRUE if the template TMPL is dependent. */
19810 bool
19812 {
19814 {
19816 {
19820 }
19822 }
19824 /* Template template parameters are dependent. */
19828 /* So are names that have not been looked up. */
19832 /* So are member templates of dependent classes. */
19836 }
19838 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19840 bool
19842 {
19845 }
19847 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19848 is dependent. */
19850 bool
19852 {
19859 {
19880 {
19884 }
19888 {
19892 {
19897 }
19898 }
19899 }
19902 }
19904 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19905 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19906 no such TYPE can be found. Note that this function peers inside
19907 uninstantiated templates and therefore should be used only in
19908 extremely limited situations. ONLY_CURRENT_P restricts this
19909 peering to the currently open classes hierarchy (which is required
19910 when comparing types). */
19912 tree
19914 {
19915 tree scope;
19916 tree name;
19917 tree decl;
19919 tree pushed_scope;
19920 tree result;
19925 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19926 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19927 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19928 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19929 identifier of the TYPENAME_TYPE anymore.
19930 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19931 TYPENAME_TYPE instead, we avoid messing up with a possible
19932 typedef variant case. */
19935 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19936 it first before we can figure out what NAME refers to. */
19939 /* If we don't know what SCOPE refers to, then we cannot resolve the
19940 TYPENAME_TYPE. */
19943 /* If the SCOPE is a template type parameter, we have no way of
19944 resolving the name. */
19947 /* If the SCOPE is not the current instantiation, there's no reason
19948 to look inside it. */
19951 /* If this is a typedef, we don't want to look inside (c++/11987). */
19954 /* If SCOPE isn't the template itself, it will not have a valid
19955 TYPE_FIELDS list. */
19957 /* scope is either the template itself or a compatible instantiation
19958 like X<T>, so look up the name in the original template. */
19960 else
19961 /* scope is a partial instantiation, so we can't do the lookup or we
19962 will lose the template arguments. */
19964 /* Enter the SCOPE so that name lookup will be resolved as if we
19965 were in the class definition. In particular, SCOPE will no
19966 longer be considered a dependent type. */
19968 /* Look up the declaration. */
19970 tf_warning_or_error);
19974 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19975 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19980 {
19984 }
19987 {
19988 tree tmpl;
19989 tree args;
19990 /* Obtain the template and the arguments. */
19993 /* Instantiate the template. */
19999 }
20001 /* Leave the SCOPE. */
20005 /* If we failed to resolve it, return the original typename. */
20009 /* If lookup found a typename type, resolve that too. */
20011 {
20012 /* Ill-formed programs can cause infinite recursion here, so we
20013 must catch that. */
20017 }
20019 /* Qualify the resulting type. */
20025 }
20027 /* EXPR is an expression which is not type-dependent. Return a proxy
20028 for EXPR that can be used to compute the types of larger
20029 expressions containing EXPR. */
20031 tree
20033 {
20034 tree inner_expr;
20036 #ifdef ENABLE_CHECKING
20037 /* Try to get a constant value for all non-type-dependent expressions in
20038 order to expose bugs in *_dependent_expression_p and constexpr. */
20041 #endif
20043 /* Preserve OVERLOADs; the functions must be available to resolve
20044 types. */
20055 /* There is no need to return a proxy for a variable. */
20058 /* Preserve string constants; conversions from string constants to
20059 "char *" are allowed, even though normally a "const char *"
20060 cannot be used to initialize a "char *". */
20063 /* Preserve arithmetic constants, as an optimization -- there is no
20064 reason to create a new node. */
20067 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20068 There is at least one place where we want to know that a
20069 particular expression is a throw-expression: when checking a ?:
20070 expression, there are special rules if the second or third
20071 argument is a throw-expression. */
20075 /* Don't wrap an initializer list, we need to be able to look inside. */
20079 /* Don't wrap a dummy object, we need to be able to test for it. */
20098 /* If the type is unknown, it can't really be non-dependent */
20101 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20103 }
20105 /* ARGS is a vector of expressions as arguments to a function call.
20106 Replace the arguments with equivalent non-dependent expressions.
20107 This modifies ARGS in place. */
20109 void
20111 {
20113 tree arg;
20116 {
20120 }
20121 }
20123 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20124 with a level one deeper than the actual template parms. */
20126 tree
20128 {
20141 }
20143 /* Given type ARG, return std::initializer_list<ARG>. */
20145 static tree
20147 {
20148 tree std_init_list = namespace_binding
20150 tree argvec;
20152 {
20156 }
20161 }
20163 /* Replace auto in TYPE with std::initializer_list<auto>. */
20165 static tree
20167 {
20174 }
20176 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20177 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20179 tree
20181 {
20190 /* Defining a subset of type-dependent expressions that we can deduce
20191 from ahead of time isn't worth the trouble. */
20194 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20195 with either a new invented type template parameter U or, if the
20196 initializer is a braced-init-list (8.5.4), with
20197 std::initializer_list<U>. */
20213 {
20215 /* Try again at instantiation time. */
20218 /* If type is error_mark_node a diagnostic must have been
20219 emitted by now. Also, having a mention to '<type error>'
20220 in the diagnostic is not really useful to the user. */
20221 {
20225 else
20227 }
20229 }
20231 /* If the list of declarators contains more than one declarator, the type
20232 of each declared variable is determined as described above. If the
20233 type deduced for the template parameter U is not the same in each
20234 deduction, the program is ill-formed. */
20237 {
20243 else
20247 }
20253 }
20255 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20256 result. */
20258 tree
20260 {
20261 tree argvec;
20268 /* For a late-specified return type in a template type-parameter, we
20269 need to add a dummy argument level for its parmlist. */
20270 argvec = add_to_template_args
20275 }
20277 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20279 bool
20281 {
20285 else
20287 }
20289 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20290 appear as a type-specifier for the declaration in question, we don't
20291 have to look through the whole type. */
20293 tree
20295 {
20312 }
20314 /* For a given template T, return the vector of typedefs referenced
20315 in T for which access check is needed at T instantiation time.
20316 T is either a FUNCTION_DECL or a RECORD_TYPE.
20317 Those typedefs were added to T by the function
20318 append_type_to_template_for_access_check. */
20322 {
20323 tree ti;
20334 {
20339 }
20342 }
20344 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20345 tied to T. That list of typedefs will be access checked at
20346 T instantiation time.
20347 T is either a FUNCTION_DECL or a RECORD_TYPE.
20348 TYPE_DECL is a TYPE_DECL node representing a typedef.
20349 SCOPE is the scope through which TYPE_DECL is accessed.
20350 LOCATION is the location of the usage point of TYPE_DECL.
20352 This function is a subroutine of
20353 append_type_to_template_for_access_check. */
20355 static void
20357 tree type_decl,
20358 tree scope,
20359 location_t location)
20360 {
20361 qualified_typedef_usage_t typedef_usage;
20362 tree ti;
20369 && type_decl
20385 }
20387 /* Append TYPE_DECL to the template TEMPL.
20388 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20389 At TEMPL instanciation time, TYPE_DECL will be checked to see
20390 if it can be accessed through SCOPE.
20391 LOCATION is the location of the usage point of TYPE_DECL.
20393 e.g. consider the following code snippet:
20395 class C
20396 {
20397 typedef int myint;
20398 };
20400 template<class U> struct S
20401 {
20402 C::myint mi; // <-- usage point of the typedef C::myint
20403 };
20405 S<char> s;
20407 At S<char> instantiation time, we need to check the access of C::myint
20408 In other words, we need to check the access of the myint typedef through
20409 the C scope. For that purpose, this function will add the myint typedef
20410 and the scope C through which its being accessed to a list of typedefs
20411 tied to the template S. That list will be walked at template instantiation
20412 time and access check performed on each typedefs it contains.
20413 Note that this particular code snippet should yield an error because
20414 myint is private to C. */
20416 void
20418 tree type_decl,
20419 tree scope,
20420 location_t location)
20421 {
20427 /* Make sure we don't append the type to the template twice. */
20436 }
20438 /* Set up the hash tables for template instantiations. */
20440 void
20442 {
20444 hash_specialization,
20445 eq_specializations,
20446 ggc_free);
20448 hash_specialization,
20449 eq_specializations,
20450 ggc_free);
20451 }
20453 /* Print stats about the template hash tables for -fstats. */
20455 void
20457 {
20466 }