| blob | b3a9c95ac609d4508a95a295353e5529e8252834 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
50 /* The type of functions taking a tree, and some additional data, and
51 returning an int. */
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
60 };
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
80 /* True if we've recursed into fn_type_unification too many times. */
84 {
85 tree tmpl;
86 tree args;
87 tree spec;
91 htab_t decl_specializations;
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 tbr_incomplete_type,
113 tbr_ambiguous_baseclass,
114 tbr_success
115 };
138 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, VAR_DECL for static member variable, or TYPE_DECL for
212 alias template (needed by 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 {
337 }
339 /* Returns the template nesting level of the indicated class TYPE.
341 For example, in:
342 template <class T>
343 struct A
344 {
345 template <class U>
346 struct B {};
347 };
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
355 always safe. */
357 int
359 {
366 {
372 }
375 }
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
380 static bool
382 {
388 }
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
393 innermost first. */
395 static void
397 {
405 current_template_parms
411 NULL);
413 {
422 {
429 {
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
433 available. */
443 }
448 }
449 }
450 }
452 /* Restore the template parameter context for a member template, a
453 friend template defined in a class definition, or a non-template
454 member of template class. */
456 void
458 {
459 tree parms;
464 {
467 /* Disregard full specializations (c++/60999). */
470 }
473 {
478 {
481 }
484 }
486 /* Remember how many levels of template parameters we pushed so that
487 we can pop them later. */
489 }
491 /* Undo the effects of maybe_begin_member_template_processing. */
493 void
495 {
504 {
508 }
509 }
511 /* Return a new template argument vector which contains all of ARGS,
512 but has as its innermost set of arguments the EXTRA_ARGS. */
514 static tree
516 {
517 tree new_args;
535 }
537 /* Like add_to_template_args, but only the outermost ARGS are added to
538 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
539 (EXTRA_ARGS) levels are added. This function is used to combine
540 the template arguments from a partial instantiation with the
541 template arguments used to attain the full instantiation from the
542 partial instantiation. */
544 static tree
546 {
547 tree new_args;
549 /* If there are more levels of EXTRA_ARGS than there are ARGS,
550 something very fishy is going on. */
553 /* If *all* the new arguments will be the EXTRA_ARGS, just return
554 them. */
558 /* For the moment, we make ARGS look like it contains fewer levels. */
563 /* Now, we restore ARGS to its full dimensions. */
567 }
569 /* Return the N levels of innermost template arguments from the ARGS. */
571 tree
573 {
574 tree new_args;
580 /* If N is 1, just return the innermost set of template arguments. */
584 /* If we're not removing anything, just return the arguments we were
585 given. */
591 /* Make a new set of arguments, not containing the outer arguments. */
598 }
600 /* The inverse of get_innermost_template_args: Return all but the innermost
601 EXTRA_LEVELS levels of template arguments from the ARGS. */
603 static tree
605 {
606 tree new_args;
612 /* If N is 1, just return the outermost set of template arguments. */
616 /* If we're not removing anything, just return the arguments we were
617 given. */
622 /* Make a new set of arguments, not containing the inner arguments. */
629 }
631 /* We've got a template header coming up; push to a new level for storing
632 the parms. */
634 void
636 {
637 /* We use a non-tag-transparent scope here, which causes pushtag to
638 put tags in this scope, rather than in the enclosing class or
639 namespace scope. This is the right thing, since we want
640 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
641 global template class, push_template_decl handles putting the
642 TEMPLATE_DECL into top-level scope. For a nested template class,
643 e.g.:
645 template <class T> struct S1 {
646 template <class T> struct S2 {};
647 };
649 pushtag contains special code to call pushdecl_with_scope on the
650 TEMPLATE_DECL for S2. */
655 }
657 /* This routine is called when a specialization is declared. If it is
658 invalid to declare a specialization here, an error is reported and
659 false is returned, otherwise this routine will return true. */
661 static bool
663 {
666 /* [temp.expl.spec]
668 An explicit specialization shall be declared in the namespace of
669 which the template is a member, or, for member templates, in the
670 namespace of which the enclosing class or enclosing class
671 template is a member. An explicit specialization of a member
672 function, member class or static data member of a class template
673 shall be declared in the namespace of which the class template
674 is a member. */
676 {
679 }
681 /* [temp.expl.spec]
683 In an explicit specialization declaration for a member of a class
684 template or a member template that appears in namespace scope,
685 the member template and some of its enclosing class templates may
686 remain unspecialized, except that the declaration shall not
687 explicitly specialize a class member template if its enclosing
688 class templates are not explicitly specialized as well. */
690 {
693 }
696 }
698 /* We've just seen template <>. */
700 bool
702 {
706 }
708 /* Called at then end of processing a declaration preceded by
709 template<>. */
711 void
713 {
716 }
718 /* Any template <>'s that we have seen thus far are not referring to a
719 function specialization. */
721 void
723 {
726 }
728 /* We've just seen a template header. If SPECIALIZATION is nonzero,
729 it was of the form template <>. */
731 static void
733 {
735 template_header_count++;
736 }
738 /* We're beginning an explicit instantiation. */
740 void
742 {
745 }
748 void
750 {
753 }
755 /* An explicit specialization or partial specialization of TMPL is being
756 declared. Check that the namespace in which the specialization is
757 occurring is permissible. Returns false iff it is invalid to
758 specialize TMPL in the current namespace. */
760 static bool
762 {
765 /* [tmpl.expl.spec]
767 An explicit specialization shall be declared in the namespace of
768 which the template is a member, or, for member templates, in the
769 namespace of which the enclosing class or enclosing class
770 template is a member. An explicit specialization of a member
771 function, member class or static data member of a class template
772 shall be declared in the namespace of which the class template is
773 a member. */
776 {
779 }
781 /* Same or super-using namespace. */
783 else
784 {
788 }
789 }
791 /* SPEC is an explicit instantiation. Check that it is valid to
792 perform this explicit instantiation in the current namespace. */
794 static void
796 {
797 tree ns;
799 /* DR 275: An explicit instantiation shall appear in an enclosing
800 namespace of its template. */
806 }
808 /* The TYPE is being declared. If it is a template type, that means it
809 is a partial specialization. Do appropriate error-checking. */
811 tree
813 {
814 tree context;
819 /* A lambda that appears in specialization context is not itself a
820 specialization. */
825 {
829 }
834 {
839 else
842 }
844 {
845 /* This is for ordinary explicit specialization and partial
846 specialization of a template class such as:
848 template <> class C<int>;
850 or:
852 template <class T> class C<T*>;
854 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
858 {
865 {
869 }
870 }
876 /* Trying to define a specialization either without a template<> header
877 or in an inappropriate place. We've already given an error, so just
878 bail now so we don't actually define the specialization. */
880 }
886 {
887 /* This is for an explicit specialization of member class
888 template according to [temp.expl.spec/18]:
890 template <> template <class U> class C<int>::D;
892 The context `C<int>' must be an implicit instantiation.
893 Otherwise this is just a member class template declared
894 earlier like:
896 template <> class C<int> { template <class U> class D; };
897 template <> template <class U> class C<int>::D;
899 In the first case, `C<int>::D' is a specialization of `C<T>::D'
900 while in the second case, `C<int>::D' is a primary template
901 and `C<T>::D' may not exist. */
905 {
906 tree t;
911 {
914 }
916 /* Check for invalid specialization after instantiation:
918 template <> template <> class C<int>::D<int>;
919 template <> template <class U> class C<int>::D; */
923 {
927 {
928 /* We already have a full specialization of this partial
929 instantiation, or a full specialization has been
930 looked up but not instantiated. Reassign it to the
931 new member specialization template. */
932 spec_entry elt;
949 }
950 else
951 /* But if we've had an implicit instantiation, that's a
952 problem ([temp.expl.spec]/6). */
955 }
957 /* Mark TYPE as a specialization. And as a result, we only
958 have one level of template argument for the innermost
959 class template. */
964 }
965 }
967 {
968 /* Someday C++0x may allow for enum template specialization. */
973 else
974 {
977 }
978 }
981 }
983 /* Returns nonzero if we can optimize the retrieval of specializations
984 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
985 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
989 {
992 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
993 parameter. */
995 /* The optimized lookup depends on the fact that the
996 template arguments for the member function template apply
997 purely to the containing class, which is not true if the
998 containing class is an explicit or partial
999 specialization. */
1003 /* It is possible to have a template that is not a member
1004 template and is not a member of a template class:
1006 template <typename T>
1007 struct S { friend A::f(); };
1009 Here, the friend function is a template, but the context does
1010 not have template information. The optimized lookup relies
1011 on having ARGS be the template arguments for both the class
1012 and the function template. */
1014 }
1016 /* Retrieve the specialization (in the sense of [temp.spec] - a
1017 specialization is either an instantiation or an explicit
1018 specialization) of TMPL for the given template ARGS. If there is
1019 no such specialization, return NULL_TREE. The ARGS are a vector of
1020 arguments, or a vector of vectors of arguments, in the case of
1021 templates with more than one level of parameters.
1023 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1024 then we search for a partial specialization matching ARGS. This
1025 parameter is ignored if TMPL is not a class template.
1027 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1028 result is a NONTYPE_ARGUMENT_PACK. */
1030 static tree
1032 {
1042 /* There should be as many levels of arguments as there are
1043 levels of parameters. */
1050 {
1051 tree class_template;
1052 tree class_specialization;
1054 tree fns;
1057 /* The template arguments actually apply to the containing
1058 class. Find the class specialization with those
1059 arguments. */
1061 class_specialization
1065 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1066 for the specialization. */
1070 /* Iterate through the methods with the indicated name, looking
1071 for the one that has an instance of TMPL. */
1074 {
1077 /* using-declarations can add base methods to the method vec,
1078 and we don't want those here. */
1081 }
1083 }
1084 else
1085 {
1087 spec_entry elt;
1088 htab_t specializations;
1096 else
1104 }
1107 }
1109 /* Like retrieve_specialization, but for local declarations. */
1111 static tree
1113 {
1119 }
1121 /* Returns nonzero iff DECL is a specialization of TMPL. */
1123 int
1125 {
1126 tree t;
1129 {
1135 }
1136 else
1137 {
1146 }
1149 }
1151 /* Returns nonzero iff DECL is a specialization of friend declaration
1152 FRIEND_DECL according to [temp.friend]. */
1154 bool
1156 {
1163 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1164 of a template class, we want to check if DECL is a specialization
1165 if this. */
1169 {
1170 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1173 }
1178 /* There is nothing to do if this is not a template friend. */
1185 /* [temp.friend/6]
1186 A member of a class template may be declared to be a friend of a
1187 non-template class. In this case, the corresponding member of
1188 every specialization of the class template is a friend of the
1189 class granting friendship.
1191 For example, given a template friend declaration
1193 template <class T> friend void A<T>::f();
1195 the member function below is considered a friend
1197 template <> struct A<int> {
1198 void f();
1199 };
1201 For this type of template friend, TEMPLATE_DEPTH below will be
1202 nonzero. To determine if DECL is a friend of FRIEND, we first
1203 check if the enclosing class is a specialization of another. */
1210 {
1211 /* Next, we check the members themselves. In order to handle
1212 a few tricky cases, such as when FRIEND_DECL's are
1214 template <class T> friend void A<T>::g(T t);
1215 template <class T> template <T t> friend void A<T>::h();
1217 and DECL's are
1219 void A<int>::g(int);
1220 template <int> void A<int>::h();
1222 we need to figure out ARGS, the template arguments from
1223 the context of DECL. This is required for template substitution
1224 of `T' in the function parameter of `g' and template parameter
1225 of `h' in the above examples. Here ARGS corresponds to `int'. */
1232 {
1234 {
1237 else
1239 current_depth++;
1240 }
1242 }
1245 {
1247 tree friend_type;
1248 tree decl_type;
1249 tree friend_args_type;
1250 tree decl_args_type;
1252 /* Make sure that both DECL and FRIEND_DECL are templates or
1253 non-templates. */
1259 {
1260 /* If both are templates, check template parameter list. */
1261 tree friend_parms
1266 friend_parms))
1270 }
1271 else
1279 /* Check if return types match. */
1283 /* Check if function parameter types match, ignoring the
1284 `this' parameter. */
1293 }
1294 else
1295 {
1296 /* DECL is a TYPE_DECL */
1300 /* Make sure that both DECL and FRIEND_DECL are templates or
1301 non-templates. */
1302 is_template
1309 {
1310 tree friend_parms;
1311 /* If both are templates, check the name of the two
1312 TEMPLATE_DECL's first because is_friend didn't. */
1317 /* Now check template parameter list. */
1318 friend_parms
1321 return comp_template_parms
1323 friend_parms);
1324 }
1325 else
1328 }
1329 }
1331 }
1333 /* Register the specialization SPEC as a specialization of TMPL with
1334 the indicated ARGS. IS_FRIEND indicates whether the specialization
1335 is actually just a friend declaration. Returns SPEC, or an
1336 equivalent prior declaration, if available.
1338 We also store instantiations of field packs in the hash table, even
1339 though they are not themselves templates, to make lookup easier. */
1341 static tree
1343 hashval_t hash)
1344 {
1345 tree fn;
1347 spec_entry elt;
1355 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1356 register it; we want the corresponding TEMPLATE_DECL instead.
1357 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1358 the more obvious `uses_template_parms (spec)' to avoid problems
1359 with default function arguments. In particular, given
1360 something like this:
1362 template <class T> void f(T t1, T t = T())
1364 the default argument expression is not substituted for in an
1365 instantiation unless and until it is actually needed. */
1369 /* We don't put these specializations in the hash table, but we might
1370 want to give an error about a mismatch. */
1372 else
1373 {
1381 slot =
1385 else
1387 }
1389 /* We can sometimes try to re-register a specialization that we've
1390 already got. In particular, regenerate_decl_from_template calls
1391 duplicate_decls which will update the specialization list. But,
1392 we'll still get called again here anyhow. It's more convenient
1393 to simply allow this than to try to prevent it. */
1397 {
1399 {
1402 {
1404 fn);
1406 }
1407 else
1408 {
1409 tree clone;
1410 /* This situation should occur only if the first
1411 specialization is an implicit instantiation, the
1412 second is an explicit specialization, and the
1413 implicit instantiation has not yet been used. That
1414 situation can occur if we have implicitly
1415 instantiated a member function and then specialized
1416 it later.
1418 We can also wind up here if a friend declaration that
1419 looked like an instantiation turns out to be a
1420 specialization:
1422 template <class T> void foo(T);
1423 class S { friend void foo<>(int) };
1424 template <> void foo(int);
1426 We transform the existing DECL in place so that any
1427 pointers to it become pointers to the updated
1428 declaration.
1430 If there was a definition for the template, but not
1431 for the specialization, we want this to look as if
1432 there were no definition, and vice versa. */
1435 /* The call to duplicate_decls will have applied
1436 [temp.expl.spec]:
1438 An explicit specialization of a function template
1439 is inline only if it is explicitly declared to be,
1440 and independently of whether its function template
1441 is.
1443 to the primary function; now copy the inline bits to
1444 the various clones. */
1446 {
1453 }
1457 }
1458 }
1460 {
1462 /* Dup decl failed, but this is a new definition. Set the
1463 line number so any errors match this new
1464 definition. */
1468 }
1469 }
1473 /* A specialization must be declared in the same namespace as the
1474 template it is specializing. */
1480 {
1488 /* TMPL is a forward declaration of a template function; keep a list
1489 of all specializations in case we need to reassign them to a friend
1490 template later in tsubst_friend_function. */
1493 }
1496 }
1498 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1499 TMPL and ARGS members, ignores SPEC. */
1503 static int
1505 {
1516 }
1518 /* Returns a hash for a template TMPL and template arguments ARGS. */
1520 static hashval_t
1522 {
1525 }
1527 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1528 ignoring SPEC. */
1530 static hashval_t
1532 {
1535 }
1537 /* Recursively calculate a hash value for a template argument ARG, for use
1538 in the hash tables of template specializations. */
1540 hashval_t
1542 {
1554 /* We can get one of these when re-hashing a previous entry in the middle
1555 of substituting into a pack expansion. Just look through it. */
1564 {
1572 {
1577 }
1599 {
1602 {
1605 }
1607 }
1611 {
1614 }
1625 val = iterative_hash_template_arg
1637 val);
1639 val);
1648 /* A lambda can't appear in a template arg, but don't crash on
1649 erroneous input. */
1661 /* Now hash operands as usual. */
1666 }
1669 {
1673 val);
1676 /* Otherwise just compare the types during lookup. */
1685 {
1690 }
1691 }
1694 }
1696 /* Unregister the specialization SPEC as a specialization of TMPL.
1697 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1698 if the SPEC was listed as a specialization of TMPL.
1700 Note that SPEC has been ggc_freed, so we can't look inside it. */
1702 bool
1704 {
1706 spec_entry elt;
1714 {
1719 }
1722 }
1724 /* Like register_specialization, but for local declarations. We are
1725 registering SPEC, an instantiation of TMPL. */
1727 static void
1729 {
1731 }
1733 /* TYPE is a class type. Returns true if TYPE is an explicitly
1734 specialized class. */
1736 bool
1738 {
1742 }
1744 /* Print the list of functions at FNS, going through all the overloads
1745 for each element of the list. Alternatively, FNS can not be a
1746 TREE_LIST, in which case it will be printed together with all the
1747 overloads.
1749 MORE and *STR should respectively be FALSE and NULL when the function
1750 is called from the outside. They are used internally on recursive
1751 calls. print_candidates manages the two parameters and leaves NULL
1752 in *STR when it ends. */
1754 static void
1756 {
1762 {
1766 }
1767 else
1768 {
1771 {
1772 /* Pick the prefix string. */
1774 {
1778 }
1782 }
1785 }
1788 {
1791 }
1792 }
1794 /* Print the list of candidate FNS in an error message. FNS can also
1795 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1797 void
1799 {
1803 }
1805 /* Returns the template (one of the functions given by TEMPLATE_ID)
1806 which can be specialized to match the indicated DECL with the
1807 explicit template args given in TEMPLATE_ID. The DECL may be
1808 NULL_TREE if none is available. In that case, the functions in
1809 TEMPLATE_ID are non-members.
1811 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1812 specialization of a member template.
1814 The TEMPLATE_COUNT is the number of references to qualifying
1815 template classes that appeared in the name of the function. See
1816 check_explicit_specialization for a more accurate description.
1818 TSK indicates what kind of template declaration (if any) is being
1819 declared. TSK_TEMPLATE indicates that the declaration given by
1820 DECL, though a FUNCTION_DECL, has template parameters, and is
1821 therefore a template function.
1823 The template args (those explicitly specified and those deduced)
1824 are output in a newly created vector *TARGS_OUT.
1826 If it is impossible to determine the result, an error message is
1827 issued. The error_mark_node is returned to indicate failure. */
1829 static tree
1831 tree decl,
1835 tmpl_spec_kind tsk)
1836 {
1837 tree fns;
1838 tree targs;
1839 tree explicit_targs;
1841 /* A TREE_LIST of templates of which DECL may be a specialization.
1842 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1843 corresponding TREE_PURPOSE is the set of template arguments that,
1844 when used to instantiate the template, would produce a function
1845 with the signature of DECL. */
1855 /* We shouldn't be specializing a member template of an
1856 unspecialized class template; we already gave an error in
1857 check_specialization_scope, now avoid crashing. */
1860 {
1863 }
1871 /* Check for baselinks. */
1876 {
1879 }
1881 {
1884 }
1886 /* Count the number of template headers specified for this
1887 specialization. */
1897 {
1901 {
1902 tree decl_arg_types;
1903 tree fn_arg_types;
1904 tree insttype;
1906 /* In case of explicit specialization, we need to check if
1907 the number of template headers appearing in the specialization
1908 is correct. This is usually done in check_explicit_specialization,
1909 but the check done there cannot be exhaustive when specializing
1910 member functions. Consider the following code:
1912 template <> void A<int>::f(int);
1913 template <> template <> void A<int>::f(int);
1915 Assuming that A<int> is not itself an explicit specialization
1916 already, the first line specializes "f" which is a non-template
1917 member function, whilst the second line specializes "f" which
1918 is a template member function. So both lines are syntactically
1919 correct, and check_explicit_specialization does not reject
1920 them.
1922 Here, we can do better, as we are matching the specialization
1923 against the declarations. We count the number of template
1924 headers, and we check if they match TEMPLATE_COUNT + 1
1925 (TEMPLATE_COUNT is the number of qualifying template classes,
1926 plus there must be another header for the member template
1927 itself).
1929 Notice that if header_count is zero, this is not a
1930 specialization but rather a template instantiation, so there
1931 is no check we can perform here. */
1935 /* Check that the number of template arguments at the
1936 innermost level for DECL is the same as for FN. */
1944 /* DECL might be a specialization of FN. */
1948 /* For a non-static member function, we need to make sure
1949 that the const qualification is the same. Since
1950 get_bindings does not try to merge the "this" parameter,
1951 we must do the comparison explicitly. */
1957 /* Skip the "this" parameter and, for constructors of
1958 classes with virtual bases, the VTT parameter. A
1959 full specialization of a constructor will have a VTT
1960 parameter, but a template never will. */
1961 decl_arg_types
1963 fn_arg_types
1966 /* Function templates cannot be specializations; there are
1967 no partial specializations of functions. Therefore, if
1968 the type of DECL does not match FN, there is no
1969 match. */
1971 {
1975 }
1977 /* See whether this function might be a specialization of this
1978 template. Suppress access control because we might be trying
1979 to make this specialization a friend, and we have already done
1980 access control for the declaration of the specialization. */
1986 /* We cannot deduce template arguments that when used to
1987 specialize TMPL will produce DECL. */
1990 /* Make sure that the deduced arguments actually work. */
1994 fn_arg_types
1999 /* Save this template, and the arguments deduced. */
2001 }
2003 /* FN is an ordinary member function, and we need a
2004 specialization of a member template. */
2005 ;
2007 /* We can get IDENTIFIER_NODEs here in certain erroneous
2008 cases. */
2009 ;
2011 /* This is just an ordinary non-member function. Nothing can
2012 be a specialization of that. */
2013 ;
2015 /* Cannot specialize functions that are created implicitly. */
2016 ;
2017 else
2018 {
2019 tree decl_arg_types;
2021 /* This is an ordinary member function. However, since
2022 we're here, we can assume its enclosing class is a
2023 template class. For example,
2025 template <typename T> struct S { void f(); };
2026 template <> void S<int>::f() {}
2028 Here, S<int>::f is a non-template, but S<int> is a
2029 template class. If FN has the same type as DECL, we
2030 might be in business. */
2033 /* Its enclosing class is an explicit specialization
2034 of a template class. This is not a candidate. */
2039 /* The return types differ. */
2042 /* Adjust the type of DECL in case FN is a static member. */
2049 decl_arg_types))
2050 /* They match! */
2052 }
2053 }
2056 {
2057 /* We have:
2059 [temp.expl.spec]
2061 It is possible for a specialization with a given function
2062 signature to be instantiated from more than one function
2063 template. In such cases, explicit specification of the
2064 template arguments must be used to uniquely identify the
2065 function template specialization being specialized.
2067 Note that here, there's no suggestion that we're supposed to
2068 determine which of the candidate templates is most
2069 specialized. However, we, also have:
2071 [temp.func.order]
2073 Partial ordering of overloaded function template
2074 declarations is used in the following contexts to select
2075 the function template to which a function template
2076 specialization refers:
2078 -- when an explicit specialization refers to a function
2079 template.
2081 So, we do use the partial ordering rules, at least for now.
2082 This extension can only serve to make invalid programs valid,
2083 so it's safe. And, there is strong anecdotal evidence that
2084 the committee intended the partial ordering rules to apply;
2085 the EDG front end has that behavior, and John Spicer claims
2086 that the committee simply forgot to delete the wording in
2087 [temp.expl.spec]. */
2090 {
2093 }
2094 }
2097 {
2105 }
2109 {
2115 }
2117 /* We have one, and exactly one, match. */
2119 {
2122 /* DECL is a re-declaration or partial instantiation of a template
2123 function. */
2126 /* It was a specialization of an ordinary member function in a
2127 template class. */
2129 }
2131 /* It was a specialization of a template. */
2134 {
2139 }
2140 else
2143 }
2145 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2146 but with the default argument values filled in from those in the
2147 TMPL_TYPES. */
2149 static tree
2151 tree tmpl_types)
2152 {
2153 tree new_spec_types;
2161 /* Substitute into the rest of the list. */
2162 new_spec_types =
2166 /* Add the default argument for this parameter. */
2169 new_spec_types);
2170 }
2172 /* DECL is an explicit specialization. Replicate default arguments
2173 from the template it specializes. (That way, code like:
2175 template <class T> void f(T = 3);
2176 template <> void f(double);
2177 void g () { f (); }
2179 works, as required.) An alternative approach would be to look up
2180 the correct default arguments at the call-site, but this approach
2181 is consistent with how implicit instantiations are handled. */
2183 static void
2185 {
2186 tree tmpl;
2187 tree spec_types;
2188 tree tmpl_types;
2189 tree new_spec_types;
2190 tree old_type;
2191 tree new_type;
2192 tree t;
2197 /* See if there's anything we need to do. */
2210 {
2211 /* Remove the this pointer, but remember the object's type for
2212 CV quals. */
2218 {
2219 /* DECL may contain more parameters than TMPL due to the extra
2220 in-charge parameter in constructors and destructors. */
2223 }
2225 {
2228 }
2229 }
2231 /* Compute the merged default arguments. */
2232 new_spec_types =
2235 /* Compute the new FUNCTION_TYPE. */
2237 {
2241 new_spec_types);
2244 /* Put the in-charge parameter back. */
2247 new_spec_types);
2251 new_spec_types);
2252 }
2253 else
2255 new_spec_types);
2265 }
2267 /* Return the number of template headers we expect to see for a definition
2268 or specialization of CTYPE or one of its non-template members. */
2270 int
2272 {
2276 {
2277 /* You're supposed to have one `template <...>' for every
2278 template class, but you don't need one for a full
2279 specialization. For example:
2281 template <class T> struct S{};
2282 template <> struct S<int> { void f(); };
2283 void S<int>::f () {}
2285 is correct; there shouldn't be a `template <>' for the
2286 definition of `S<int>::f'. */
2288 /* If CTYPE does not have template information of any
2289 kind, then it is not a template, nor is it nested
2290 within a template. */
2298 }
2301 }
2303 /* Do a simple sanity check on the template headers that precede the
2304 variable declaration DECL. */
2306 void
2308 {
2313 {
2316 "variable templates only available with "
2319 // Namespace-scope variable templates should have a template header.
2321 }
2323 {
2330 "members of an explicitly specialized class are defined "
2332 }
2333 }
2335 /* Check to see if the function just declared, as indicated in
2336 DECLARATOR, and in DECL, is a specialization of a function
2337 template. We may also discover that the declaration is an explicit
2338 instantiation at this point.
2340 Returns DECL, or an equivalent declaration that should be used
2341 instead if all goes well. Issues an error message if something is
2342 amiss. Returns error_mark_node if the error is not easily
2343 recoverable.
2345 FLAGS is a bitmask consisting of the following flags:
2347 2: The function has a definition.
2348 4: The function is a friend.
2350 The TEMPLATE_COUNT is the number of references to qualifying
2351 template classes that appeared in the name of the function. For
2352 example, in
2354 template <class T> struct S { void f(); };
2355 void S<int>::f();
2357 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2358 classes are not counted in the TEMPLATE_COUNT, so that in
2360 template <class T> struct S {};
2361 template <> struct S<int> { void f(); }
2362 template <> void S<int>::f();
2364 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2365 invalid; there should be no template <>.)
2367 If the function is a specialization, it is marked as such via
2368 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2369 is set up correctly, and it is added to the list of specializations
2370 for that template. */
2372 tree
2374 tree decl,
2377 {
2385 tmpl_spec_kind tsk;
2388 {
2391 else
2393 }
2394 else
2398 {
2401 {
2404 }
2406 {
2408 /* This could be something like:
2410 template <class T> void f(T);
2411 class S { friend void f<>(int); } */
2413 else
2414 {
2415 /* This case handles bogus declarations like template <>
2416 template <class T> void f<int>(); */
2419 declarator);
2421 }
2422 }
2426 /* The error has already been reported in
2427 check_specialization_scope. */
2433 /* Fall through. */
2446 decl);
2449 else
2453 /* Fall through. */
2456 /* In cases like template<> constexpr bool v = true;
2457 We'll give an error in check_template_variable. */
2463 else
2469 {
2470 /* This case handles bogus declarations like template <>
2471 template <class T> void f<int>(); */
2476 else
2478 declarator);
2480 }
2483 /* This is a specialization of a member template, without
2484 specialization the containing class. Something like:
2486 template <class T> struct S {
2487 template <class U> void f (U);
2488 };
2489 template <> template <class U> void S<int>::f(U) {}
2491 That's a specialization -- but of the entire template. */
2497 }
2500 /* This doesn't apply to variable templates. */
2503 {
2507 {
2511 }
2512 }
2515 {
2519 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2521 {
2522 tree fns;
2527 else
2528 {
2529 /* If there is no class context, the explicit instantiation
2530 must be at namespace scope. */
2533 /* Find the namespace binding, using the declaration
2534 context. */
2538 {
2541 }
2542 else
2543 {
2549 }
2550 }
2553 }
2559 {
2561 /* A specialization in class scope. This is invalid,
2562 but the error will already have been flagged by
2563 check_specialization_scope. */
2565 else
2566 {
2567 /* It's not valid to write an explicit instantiation in
2568 class scope, e.g.:
2570 class C { template void f(); }
2572 This case is caught by the parser. However, on
2573 something like:
2575 template class C { void f(); };
2577 (which is invalid) we can get here. The error will be
2578 issued later. */
2579 ;
2580 }
2583 }
2586 {
2587 // Ignore variable templates.
2591 /* Find the list of functions in ctype that have the same
2592 name as the declared function. */
2598 {
2603 {
2604 /* From [temp.expl.spec]:
2606 If such an explicit specialization for the member
2607 of a class template names an implicitly-declared
2608 special member function (clause _special_), the
2609 program is ill-formed.
2611 Similar language is found in [temp.explicit]. */
2614 }
2617 }
2620 {
2624 }
2625 else
2626 {
2628 tree ovl;
2630 /* For a type-conversion operator, we cannot do a
2631 name-based lookup. We might be looking for `operator
2632 int' which will be a specialization of `operator T'.
2633 So, we find *all* the conversion operators, and then
2634 select from them. */
2642 {
2644 /* There are no more conversion functions. */
2647 /* Glue all these conversion functions together
2648 with those we already have. */
2651 }
2652 }
2655 {
2658 }
2659 else
2661 }
2663 /* Figure out what exactly is being specialized at this point.
2664 Note that for an explicit instantiation, even one for a
2665 member function, we cannot tell apriori whether the
2666 instantiation is for a member template, or just a member
2667 function of a template class. Even if a member template is
2668 being instantiated, the member template arguments may be
2669 elided if they can be deduced from the rest of the
2670 declaration. */
2673 member_specialization,
2674 template_count,
2675 tsk);
2678 /* We couldn't figure out what this declaration was
2679 specializing. */
2681 else
2682 {
2686 {
2687 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2688 is done by do_decl_instantiation later. */
2694 {
2695 /* If TMPL is not the most general template (for
2696 example, if TMPL is a friend template that is
2697 injected into namespace scope), then there will
2698 be too many levels of TARGS. Remove some of them
2699 here. */
2701 tree new_targs;
2708 }
2711 }
2713 /* If we thought that the DECL was a member function, but it
2714 turns out to be specializing a static member function,
2715 make DECL a static member function as well. */
2721 /* If this is a specialization of a member template of a
2722 template class, we want to return the TEMPLATE_DECL, not
2723 the specialization of it. */
2725 {
2730 {
2731 tree parm;
2735 /* We want to use the argument list specified in the
2736 definition, not in the original declaration. */
2741 }
2744 }
2746 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2749 /* Inherit default function arguments from the template
2750 DECL is specializing. */
2754 /* This specialization has the same protection as the
2755 template it specializes. */
2759 /* 7.1.1-1 [dcl.stc]
2761 A storage-class-specifier shall not be specified in an
2762 explicit specialization...
2764 The parser rejects these, so unless action is taken here,
2765 explicit function specializations will always appear with
2766 global linkage.
2768 The action recommended by the C++ CWG in response to C++
2769 defect report 605 is to make the storage class and linkage
2770 of the explicit specialization match the templated function:
2772 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2773 */
2775 {
2779 /* This specialization has the same linkage and visibility as
2780 the function template it specializes. */
2783 {
2786 }
2789 {
2792 }
2793 }
2795 /* If DECL is a friend declaration, declared using an
2796 unqualified name, the namespace associated with DECL may
2797 have been set incorrectly. For example, in:
2799 template <typename T> void f(T);
2800 namespace N {
2801 struct S { friend void f<int>(int); }
2802 }
2804 we will have set the DECL_CONTEXT for the friend
2805 declaration to N, rather than to the global namespace. */
2810 /* This is not really a declaration of a specialization.
2811 It's just the name of an instantiation. But, it's not
2812 a request for an instantiation, either. */
2815 /* A specialization is not necessarily COMDAT. */
2821 /* Register this specialization so that we can find it
2822 again. */
2825 /* A 'structor should already have clones. */
2831 }
2832 }
2835 }
2837 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2838 parameters. These are represented in the same format used for
2839 DECL_TEMPLATE_PARMS. */
2841 int
2843 {
2844 const_tree p1;
2845 const_tree p2;
2853 {
2865 {
2869 /* If either of the template parameters are invalid, assume
2870 they match for the sake of error recovery. */
2883 }
2884 }
2887 /* One set of parameters has more parameters lists than the
2888 other. */
2892 }
2894 /* Determine whether PARM is a parameter pack. */
2896 bool
2898 {
2899 /* Determine if we have a non-type template parameter pack. */
2906 /* If this is a list of template parameters, we could get a
2907 TYPE_DECL or a TEMPLATE_DECL. */
2911 /* Otherwise it must be a type template parameter. */
2915 }
2917 /* Determine if T is a function parameter pack. */
2919 bool
2921 {
2925 }
2927 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2928 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2930 tree
2932 {
2939 }
2941 /* Return true iff the function parameter PARAM_DECL was expanded
2942 from the function parameter pack PACK. */
2944 bool
2946 {
2951 /* The parameter pack and its pack arguments have the same
2952 DECL_PARM_INDEX. */
2954 }
2956 /* Determine whether ARGS describes a variadic template args list,
2957 i.e., one that is terminated by a template argument pack. */
2959 static bool
2961 {
2963 tree last_parm;
2977 }
2979 /* Generate a new name for the parameter pack name NAME (an
2980 IDENTIFIER_NODE) that incorporates its */
2982 static tree
2984 {
2985 /* Munge the name to include the parameter index. */
2986 #define NUMBUF_LEN 128
3000 }
3002 /* Return true if T is a primary function, class or alias template
3003 instantiation. */
3005 bool
3007 {
3021 }
3023 /* Return true if PARM is a template template parameter. */
3025 bool
3027 {
3029 }
3031 /* Return true iff PARM is a DECL representing a type template
3032 parameter. */
3034 bool
3036 {
3041 }
3043 /* Return the template parameters of T if T is a
3044 primary template instantiation, NULL otherwise. */
3046 tree
3048 {
3053 parms = INNERMOST_TEMPLATE_PARMS
3057 }
3059 /* Return the template parameters of the LEVELth level from the full list
3060 of template parameters PARMS. */
3062 tree
3064 {
3065 tree p;
3076 }
3078 /* Returns the template arguments of T if T is a template instantiation,
3079 NULL otherwise. */
3081 tree
3083 {
3091 }
3093 /* Return the argument pack elements of T if T is a template argument pack,
3094 NULL otherwise. */
3096 tree
3098 {
3104 }
3106 /* Structure used to track the progress of find_parameter_packs_r. */
3107 struct find_parameter_pack_data
3108 {
3109 /* TREE_LIST that will contain all of the parameter packs found by
3110 the traversal. */
3113 /* Set of AST nodes that have been visited by the traversal. */
3115 };
3117 /* Identifies all of the argument packs that occur in a template
3118 argument and appends them to the TREE_LIST inside DATA, which is a
3119 find_parameter_pack_data structure. This is a subroutine of
3120 make_pack_expansion and uses_parameter_packs. */
3121 static tree
3123 {
3129 /* Handle type aliases/typedefs. */
3131 {
3138 }
3140 /* Identify whether this is a parameter pack or not. */
3142 {
3158 {
3159 /* We don't want to walk into the type of a PARM_DECL,
3160 because we don't want to see the type parameter pack. */
3163 }
3166 /* Look through a lambda capture proxy to the field pack. */
3169 {
3175 }
3182 /* Not a parameter pack. */
3184 }
3187 {
3188 /* Add this parameter pack to the list. */
3190 }
3196 /* This switch statement will return immediately if we don't find a
3197 parameter pack. */
3199 {
3204 /* Check the template itself. */
3207 /* Check the template arguments. */
3223 /* Fall through. */
3265 }
3268 }
3270 /* Determines if the expression or type T uses any parameter packs. */
3271 bool
3273 {
3281 }
3283 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3284 representation a base-class initializer into a parameter pack
3285 expansion. If all goes well, the resulting node will be an
3286 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3287 respectively. */
3288 tree
3290 {
3291 tree result;
3300 {
3301 /* The only time we will see a TREE_LIST here is for a base
3302 class initializer. In this case, the TREE_PURPOSE will be a
3303 _TYPE node (representing the base class expansion we're
3304 initializing) and the TREE_VALUE will be a TREE_LIST
3305 containing the initialization arguments.
3307 The resulting expansion looks somewhat different from most
3308 expansions. Rather than returning just one _EXPANSION, we
3309 return a TREE_LIST whose TREE_PURPOSE is a
3310 TYPE_PACK_EXPANSION containing the bases that will be
3311 initialized. The TREE_VALUE will be identical to the
3312 original TREE_VALUE, which is a list of arguments that will
3313 be passed to each base. We do not introduce any new pack
3314 expansion nodes into the TREE_VALUE (although it is possible
3315 that some already exist), because the TREE_PURPOSE and
3316 TREE_VALUE all need to be expanded together with the same
3317 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3318 resulting TREE_PURPOSE will mention the parameter packs in
3319 both the bases and the arguments to the bases. */
3320 tree purpose;
3321 tree value;
3324 /* Determine which parameter packs will be used by the base
3325 class expansion. */
3332 {
3336 }
3339 {
3340 /* Collect the sets of parameter packs used in each of the
3341 initialization arguments. */
3343 {
3344 /* Determine which parameter packs will be expanded in this
3345 argument. */
3348 }
3349 }
3353 /* Create the pack expansion type for the base type. */
3358 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3359 they will rarely be compared to anything. */
3363 }
3368 /* Build the PACK_EXPANSION_* node. */
3369 result = for_types
3374 {
3375 /* Propagate type and const-expression information. */
3378 }
3379 else
3380 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3381 they will rarely be compared to anything. */
3384 /* Determine which parameter packs will be expanded. */
3390 /* Make sure we found some parameter packs. */
3392 {
3395 else
3398 }
3404 }
3406 /* Checks T for any "bare" parameter packs, which have not yet been
3407 expanded, and issues an error if any are found. This operation can
3408 only be done on full expressions or types (e.g., an expression
3409 statement, "if" condition, etc.), because we could have expressions like:
3411 foo(f(g(h(args)))...)
3413 where "args" is a parameter pack. check_for_bare_parameter_packs
3414 should not be called for the subexpressions args, h(args),
3415 g(h(args)), or f(g(h(args))), because we would produce erroneous
3416 error messages.
3418 Returns TRUE and emits an error if there were bare parameter packs,
3419 returns FALSE otherwise. */
3420 bool
3422 {
3438 {
3441 {
3450 else
3455 else
3459 }
3462 }
3465 }
3467 /* Expand any parameter packs that occur in the template arguments in
3468 ARGS. */
3469 tree
3471 {
3477 /* First, determine if we need to expand anything, and the number of
3478 slots we'll need. */
3480 {
3485 {
3489 else
3491 }
3492 else
3493 {
3495 num_result_args++;
3496 }
3497 }
3499 /* If no expansion is necessary, we're done. */
3503 /* Expand arguments. */
3506 non_default_args_count =
3509 {
3512 {
3519 }
3520 else
3521 {
3524 }
3525 }
3529 }
3531 /* Checks if DECL shadows a template parameter.
3533 [temp.local]: A template-parameter shall not be redeclared within its
3534 scope (including nested scopes).
3536 Emits an error and returns TRUE if the DECL shadows a parameter,
3537 returns FALSE otherwise. */
3539 bool
3541 {
3542 tree olddecl;
3544 /* If we're not in a template, we can't possibly shadow a template
3545 parameter. */
3549 /* Figure out what we're shadowing. */
3554 /* If there's no previous binding for this name, we're not shadowing
3555 anything, let alone a template parameter. */
3559 /* If we're not shadowing a template parameter, we're done. Note
3560 that OLDDECL might be an OVERLOAD (or perhaps even an
3561 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3562 node. */
3566 /* We check for decl != olddecl to avoid bogus errors for using a
3567 name inside a class. We check TPFI to avoid duplicate errors for
3568 inline member templates. */
3574 /* Don't complain about the injected class name, as we've already
3575 complained about the class itself. */
3582 }
3584 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3585 ORIG_LEVEL, DECL, and TYPE. */
3587 static tree
3591 tree decl,
3592 tree type)
3593 {
3604 }
3606 /* Find the canonical type parameter for the given template type
3607 parameter. Returns the canonical type parameter, which may be TYPE
3608 if no such parameter existed. */
3610 static tree
3612 {
3613 tree list;
3627 else
3628 {
3633 }
3634 }
3636 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3637 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3638 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3639 new one is created. */
3641 static tree
3643 tsubst_flags_t complain)
3644 {
3649 {
3668 /* Template template parameters need this. */
3673 }
3676 }
3678 /* Process information from new template parameter PARM and append it
3679 to the LIST being built. This new parameter is a non-type
3680 parameter iff IS_NON_TYPE is true. This new parameter is a
3681 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3682 is in PARM_LOC. */
3684 tree
3687 {
3689 tree defval;
3696 {
3700 {
3704 else
3706 }
3709 }
3712 {
3718 {
3719 /* [temp.param]
3721 The top-level cv-qualifiers on the template-parameter are
3722 ignored when determining its type. */
3727 && !is_parameter_pack
3728 /* If we're in a nested template parameter list, the template
3729 template parameter could be a parameter pack. */
3731 {
3732 /* This template parameter is not a parameter pack, but it
3733 should be. Complain about "bare" parameter packs. */
3736 /* Recover by calling this a parameter pack. */
3738 }
3739 }
3741 /* A template parameter is not modifiable. */
3750 processing_template_decl,
3755 }
3756 else
3757 {
3758 tree t;
3762 {
3764 /* This is for distinguishing between real templates and template
3765 template parameters */
3769 }
3770 else
3771 {
3773 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3776 }
3783 processing_template_decl,
3787 }
3793 }
3795 /* The end of a template parameter list has been reached. Process the
3796 tree list into a parameter vector, converting each parameter into a more
3797 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3798 as PARM_DECLs. */
3800 tree
3802 {
3807 current_template_parms
3812 {
3816 }
3821 }
3823 /* end_template_decl is called after a template declaration is seen. */
3825 void
3827 {
3833 /* This matches the pushlevel in begin_template_parm_list. */
3838 }
3840 /* Takes a TREE_LIST representing a template parameter and convert it
3841 into an argument suitable to be passed to the type substitution
3842 functions. Note that If the TREE_LIST contains an error_mark
3843 node, the returned argument is error_mark_node. */
3845 static tree
3847 {
3860 {
3864 {
3865 /* Turn this argument into a TYPE_ARGUMENT_PACK
3866 with a single element, which expands T. */
3868 #ifdef ENABLE_CHECKING
3869 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3871 #endif
3876 }
3877 }
3878 else
3879 {
3883 {
3884 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3885 with a single element, which expands T. */
3888 #ifdef ENABLE_CHECKING
3889 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3891 #endif
3898 }
3899 else
3901 }
3903 }
3905 /* Given a set of template parameters, return them as a set of template
3906 arguments. The template parameters are represented as a TREE_VEC, in
3907 the form documented in cp-tree.h for template arguments. */
3909 static tree
3911 {
3912 tree header;
3917 /* If there is only one level of template parameters, we do not
3918 create a TREE_VEC of TREE_VECs. Instead, we return a single
3919 TREE_VEC containing the arguments. */
3924 {
3932 #ifdef ENABLE_CHECKING
3934 #endif
3938 else
3940 }
3943 /* This can happen for template parms of a template template
3944 parameter, e.g:
3946 template<template<class T, class U> class TT> struct S;
3948 Consider the level of the parms of TT; T and U both have
3949 level 2; TT has no template parm of level 1. So in this case
3950 the first element of full_template_args is NULL_TREE. If we
3951 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3952 of 2. This will make tsubst wrongly consider that T and U
3953 have level 1. Instead, let's create a dummy vector as the
3954 first element of full_template_args so that TMPL_ARGS_DEPTH
3955 returns the correct depth for args. */
3958 }
3960 /* Within the declaration of a template, return the currently active
3961 template parameters as an argument TREE_VEC. */
3963 static tree
3965 {
3967 }
3969 /* Update the declared TYPE by doing any lookups which were thought to be
3970 dependent, but are not now that we know the SCOPE of the declarator. */
3972 tree
3974 {
3985 /* Don't bother building up the args in this case. */
3987 {
3988 /* tsubst in the args corresponding to the template parameters,
3989 including auto if present. Most things will be unchanged, but
3990 make_typename_type and tsubst_qualified_id will resolve
3991 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3994 tree pushed;
3996 {
4000 }
4005 }
4011 {
4014 else
4016 }
4018 }
4020 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4021 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4022 a member template. Used by push_template_decl below. */
4024 static tree
4026 {
4034 }
4036 struct template_parm_data
4037 {
4038 /* The level of the template parameters we are currently
4039 processing. */
4042 /* The index of the specialization argument we are currently
4043 processing. */
4046 /* An array whose size is the number of template parameters. The
4047 elements are nonzero if the parameter has been used in any one
4048 of the arguments processed so far. */
4051 /* An array whose size is the number of template arguments. The
4052 elements are nonzero if the argument makes use of template
4053 parameters of this level. */
4055 };
4057 /* Subroutine of push_template_decl used to see if each template
4058 parameter in a partial specialization is used in the explicit
4059 argument list. If T is of the LEVEL given in DATA (which is
4060 treated as a template_parm_data*), then DATA->PARMS is marked
4061 appropriately. */
4063 static int
4065 {
4073 {
4076 }
4078 /* Return zero so that for_each_template_parm will continue the
4079 traversal of the tree; we want to mark *every* template parm. */
4081 }
4083 /* Process the partial specialization DECL. */
4085 static tree
4087 {
4093 tree inner_parms;
4094 tree inst;
4107 /* We check that each of the template parameters given in the
4108 partial specialization is used in the argument list to the
4109 specialization. For example:
4111 template <class T> struct S;
4112 template <class T> struct S<T*>;
4114 The second declaration is OK because `T*' uses the template
4115 parameter T, whereas
4117 template <class T> struct S<int>;
4119 is no good. Even trickier is:
4121 template <class T>
4122 struct S1
4123 {
4124 template <class U>
4125 struct S2;
4126 template <class U>
4127 struct S2<T>;
4128 };
4130 The S2<T> declaration is actually invalid; it is a
4131 full-specialization. Of course,
4133 template <class U>
4134 struct S2<T (*)(U)>;
4136 or some such would have been OK. */
4144 {
4149 NULL,
4151 }
4154 {
4155 /* One of the template parms was not used in a deduced context in the
4156 specialization. */
4158 {
4162 }
4166 }
4171 /* [temp.class.spec]
4173 The argument list of the specialization shall not be identical to
4174 the implicit argument list of the primary template. */
4181 /* A partial specialization that replaces multiple parameters of the
4182 primary template with a pack expansion is less specialized for those
4183 parameters. */
4185 {
4187 "primary template because it replaces multiple parameters "
4191 }
4193 /* [temp.class.spec]
4195 A partially specialized non-type argument expression shall not
4196 involve template parameters of the partial specialization except
4197 when the argument expression is a simple identifier.
4199 The type of a template parameter corresponding to a specialized
4200 non-type argument shall not be dependent on a parameter of the
4201 specialization.
4203 Also, we verify that pack expansions only occur at the
4204 end of the argument list. */
4208 {
4215 {
4216 /* Extract the arguments from the argument pack. We'll be
4217 iterating over these in the following loop. */
4220 }
4223 {
4225 /* Get the Jth argument in the parameter pack. */
4229 {
4230 /* Pack expansions must come at the end of the
4231 argument list. */
4234 {
4238 else
4241 }
4242 }
4245 /* We only care about the pattern. */
4251 /* This next two lines are the `argument expression is not just a
4252 simple identifier' condition and also the `specialized
4253 non-type argument' bit. */
4257 {
4261 arg);
4262 else
4263 {
4264 /* Look at the corresponding template parameter,
4265 marking which template parameters its type depends
4266 upon. */
4270 {
4271 /* We haven't yet initialized TPD2. Do so now. */
4273 /* The number of parameters here is the number in the
4274 main template, which, as checked in the assertion
4275 above, is NARGS. */
4279 }
4281 /* Mark the template parameters. But this time, we're
4282 looking for the template parameters of the main
4283 template, not in the specialization. */
4290 NULL,
4294 {
4295 /* The type depended on some template parameters.
4296 If they are fully specialized in the
4297 specialization, that's OK. */
4306 "type %qT of template argument %qE depends "
4308 "type %qT of template argument %qE depends "
4310 type,
4311 arg);
4312 }
4313 }
4314 }
4315 }
4316 }
4318 /* We should only get here once. */
4336 {
4340 {
4344 "partial specialization of %qT after instantiation "
4346 }
4347 }
4350 }
4352 /* PARM is a template parameter of some form; return the corresponding
4353 TEMPLATE_PARM_INDEX. */
4355 static tree
4357 {
4369 }
4371 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4372 parameter packs used by the template parameter PARM. */
4374 static void
4376 {
4377 /* A type parm can't refer to another parm. */
4381 {
4385 }
4392 }
4394 /* PARM is a template parameter pack. Return any parameter packs used in
4395 its type or the type of any of its template parameters. If there are
4396 any such packs, it will be instantiated into a fixed template parameter
4397 list by partial instantiation rather than be fully deduced. */
4399 tree
4401 {
4402 /* This can only be true in a member template. */
4405 /* This can only be true for a parameter pack. */
4408 /* A type parm can't refer to another parm. */
4421 }
4423 /* Check that a template declaration's use of default arguments and
4424 parameter packs is not invalid. Here, PARMS are the template
4425 parameters. IS_PRIMARY is true if DECL is the thing declared by
4426 a primary template. IS_PARTIAL is true if DECL is a partial
4427 specialization.
4429 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4430 declaration (but not a definition); 1 indicates a declaration, 2
4431 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4432 emitted for extraneous default arguments.
4434 Returns TRUE if there were no errors found, FALSE otherwise. */
4436 bool
4439 {
4442 tree parm_level;
4445 /* [temp.param]
4447 A default template-argument shall not be specified in a
4448 function template declaration or a function template definition, nor
4449 in the template-parameter-list of the definition of a member of a
4450 class template. */
4454 /* You can't have a function template declaration in a local
4455 scope, nor you can you define a member of a class template in a
4456 local scope. */
4462 /* A lambda doesn't have an explicit declaration; don't complain
4463 about the parms of the enclosing class. */
4470 /* If this is either a friend defined in the scope of the class
4471 or a member function. */
4477 /* And, if it was a member function, it really was defined in
4478 the scope of the class. */
4481 /* We already checked these parameters when the template was
4482 declared, so there's no need to do it again now. This function
4483 was defined in class scope, but we're processing its body now
4484 that the class is complete. */
4487 /* Core issue 226 (C++0x only): the following only applies to class
4488 templates. */
4491 {
4492 /* [temp.param]
4494 If a template-parameter has a default template-argument, all
4495 subsequent template-parameters shall have a default
4496 template-argument supplied. */
4498 {
4505 {
4515 {
4517 /* For better subsequent error-recovery, we indicate that
4518 there should have been a default argument. */
4521 }
4523 && !is_friend_decl
4524 /* Don't complain about an enclosing partial
4525 specialization. */
4530 /* A fixed parameter pack will be partially
4531 instantiated into a fixed length list. */
4533 {
4534 /* A primary class template can only have one
4535 parameter pack, at the end of the template
4536 parameter list. */
4541 else
4549 }
4550 }
4551 }
4552 }
4555 || is_partial
4556 || !is_primary
4558 /* For an ordinary class template, default template arguments are
4559 allowed at the innermost level, e.g.:
4560 template <class T = int>
4561 struct S {};
4562 but, in a partial specialization, they're not allowed even
4563 there, as we have in [temp.class.spec]:
4565 The template parameter list of a specialization shall not
4566 contain default template argument values.
4568 So, for a partial specialization, or for a function template
4569 (in C++98/C++03), we look at all of them. */
4570 ;
4571 else
4572 /* But, for a primary class template that is not a partial
4573 specialization we look at all template parameters except the
4574 innermost ones. */
4577 /* Figure out what error message to issue. */
4590 else
4594 /* If we're inside a class definition, there's no need to
4595 examine the parameters to the class itself. On the one
4596 hand, they will be checked when the class is defined, and,
4597 on the other, default arguments are valid in things like:
4598 template <class T = double>
4599 struct S { template <class U> void f(U); };
4600 Here the default argument for `S' has no bearing on the
4601 declaration of `f'. */
4603 else
4604 /* Check everything. */
4610 {
4617 {
4622 {
4624 {
4631 }
4633 /* Clear out the default argument so that we are not
4634 confused later. */
4636 }
4637 }
4639 /* At this point, if we're still interested in issuing messages,
4640 they must apply to classes surrounding the object declared. */
4644 }
4647 }
4649 /* Worker for push_template_decl_real, called via
4650 for_each_template_parm. DATA is really an int, indicating the
4651 level of the parameters we are interested in. If T is a template
4652 parameter of that level, return nonzero. */
4654 static int
4656 {
4662 else
4665 }
4667 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4668 parameters given by current_template_args, or reuses a
4669 previously existing one, if appropriate. Returns the DECL, or an
4670 equivalent one, if it is replaced via a call to duplicate_decls.
4672 If IS_FRIEND is true, DECL is a friend declaration. */
4674 tree
4676 {
4677 tree tmpl;
4678 tree args;
4679 tree info;
4680 tree ctx;
4684 /* True if the template is a member template, in the sense of
4685 [temp.mem]. */
4691 /* See if this is a partial specialization. */
4700 /* For a friend, we want the context of the friend function, not
4701 the type of which it is a friend. */
4705 /* In the case of a virtual function, we want the class in which
4706 it is defined. */
4708 else
4709 /* Otherwise, if we're currently defining some class, the DECL
4710 is assumed to be a member of the class. */
4719 /* See if this is a primary template. */
4722 /* A friend template that specifies a class context, i.e.
4723 template <typename T> friend void A<T>::f();
4724 is not primary. */
4729 else
4733 {
4738 {
4741 }
4743 {
4745 {
4748 }
4750 {
4751 /* [temp.mem]
4753 A destructor shall not be a member template. */
4756 }
4763 {
4764 /* [basic.stc.dynamic.allocation]
4766 An allocation function can be a function
4767 template. ... Template allocation functions shall
4768 have two or more parameters. */
4771 }
4772 }
4778 /* alias-declaration */
4782 else
4783 {
4786 }
4787 }
4789 /* Check to see that the rules regarding the use of default
4790 arguments are not being violated. */
4794 /* Ensure that there are no parameter packs in the type of this
4795 declaration that have not been expanded. */
4797 {
4798 /* Check each of the arguments individually to see if there are
4799 any bare parameter packs. */
4805 {
4808 {
4809 /* This is a PARM_DECL that contains unexpanded parameter
4810 packs. We have already complained about this in the
4811 check_for_bare_parameter_packs call, so just replace
4812 these types with ERROR_MARK_NODE. */
4815 }
4819 }
4821 /* Check for bare parameter packs in the return type and the
4822 exception specifiers. */
4824 /* Errors were already issued, set return type to int
4825 as the frontend doesn't expect error_mark_node as
4826 the return type. */
4830 }
4835 {
4838 }
4851 {
4856 /* If DECL is a TYPE_DECL for a class-template, then there won't
4857 be DECL_LANG_SPECIFIC. The information equivalent to
4858 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4862 {
4863 /* Since a template declaration already existed for this
4864 class-type, we must be redeclaring it here. Make sure
4865 that the redeclaration is valid. */
4867 current_template_parms);
4868 /* We don't need to create a new TEMPLATE_DECL; just use the
4869 one we already had. */
4871 }
4872 else
4873 {
4875 member_template_p);
4880 {
4881 /* A specialization of a member template of a template
4882 class. */
4886 }
4887 }
4888 }
4889 else
4890 {
4896 {
4899 }
4907 {
4908 tree new_tmpl;
4910 /* The declaration is a specialization of a member
4911 template, declared outside the class. Therefore, the
4912 innermost template arguments will be NULL, so we
4913 replace them with the arguments determined by the
4914 earlier call to check_explicit_specialization. */
4917 new_tmpl
4919 member_template_p);
4929 args,
4932 }
4934 /* Make sure the template headers we got make sense. */
4939 {
4944 }
4945 else
4947 {
4952 {
4956 else
4960 /* Avoid crash in import_export_decl. */
4963 }
4968 /* Can happen in erroneous input. */
4970 else
4972 }
4974 /* Check that the parms are used in the appropriate qualifying scopes
4975 in the declarator. */
4979 {
4985 /* Avoid crash in import_export_decl. */
4988 }
4989 }
4994 /* Push template declarations for global functions and types. Note
4995 that we do not try to push a global template friend declared in a
4996 template class; such a thing may well depend on the template
4997 parameters of the class. */
5000 {
5005 /* Hide template friend classes that haven't been declared yet. */
5007 {
5010 }
5011 }
5014 {
5020 {
5023 /* It is a conversion operator. See if the type converted to
5024 depends on innermost template operands. */
5027 depth))
5029 }
5031 /* Give template template parms a DECL_CONTEXT of the template
5032 for which they are a parameter. */
5035 {
5039 }
5040 }
5042 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5043 back to its most general template. If TMPL is a specialization,
5044 ARGS may only have the innermost set of arguments. Add the missing
5045 argument levels if necessary. */
5053 else
5054 {
5059 }
5062 && !is_friend
5065 /* Set DECL_COMDAT on template instantiations; if we force
5066 them to be emitted by explicit instantiation or -frepo,
5067 mark_needed will tell cgraph to do the right thing. */
5071 }
5073 tree
5075 {
5077 }
5079 /* FN is an inheriting constructor that inherits from the constructor
5080 template INHERITED; turn FN into a constructor template with a matching
5081 template header. */
5083 tree
5085 {
5086 tree inner_parms
5089 tree parms
5100 }
5102 /* Called when a class template TYPE is redeclared with the indicated
5103 template PARMS, e.g.:
5105 template <class T> struct S;
5106 template <class T> struct S {}; */
5108 bool
5110 {
5111 tree tmpl;
5112 tree tmpl_parms;
5116 {
5119 }
5123 /* The type is nested in some template class. Nothing to worry
5124 about here; there are no new template parameters for the nested
5125 type. */
5129 {
5131 tmpl);
5133 }
5139 {
5149 }
5152 {
5153 tree tmpl_parm;
5154 tree parm;
5155 tree tmpl_default;
5156 tree parm_default;
5170 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5171 TEMPLATE_DECL. */
5181 {
5185 }
5188 {
5189 /* We have in [temp.param]:
5191 A template-parameter may not be given default arguments
5192 by two different declarations in the same scope. */
5197 }
5200 /* Update the previous template parameters (which are the ones
5201 that will really count) with the new default value. */
5204 /* Update the new parameters, too; they'll be used as the
5205 parameters for any members. */
5207 }
5210 }
5212 /* Simplify EXPR if it is a non-dependent expression. Returns the
5213 (possibly simplified) expression. */
5215 tree
5217 {
5221 /* If we're in a template, but EXPR isn't value dependent, simplify
5222 it. We're supposed to treat:
5224 template <typename T> void f(T[1 + 1]);
5225 template <typename T> void f(T[2]);
5227 as two declarations of the same function, for example. */
5231 {
5232 HOST_WIDE_INT saved_processing_template_decl;
5238 complain,
5243 }
5245 }
5247 tree
5249 {
5251 }
5253 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5254 template declaration, or a TYPE_DECL for an alias declaration. */
5256 bool
5258 {
5266 }
5268 /* Return TRUE iff is a specialization of an alias template. */
5270 bool
5272 {
5280 }
5282 /* Return the number of innermost template parameters in TMPL. */
5284 static int
5286 {
5289 }
5291 /* Return either TMPL or another template that it is equivalent to under DR
5292 1286: An alias that just changes the name of a template is equivalent to
5293 the other template. */
5295 static tree
5297 {
5300 {
5303 {
5308 {
5309 tree alias_args = INNERMOST_TEMPLATE_ARGS
5313 /* The alias type is equivalent to the pattern of the
5314 underlying template, so strip the alias. */
5317 }
5318 }
5320 }
5322 }
5324 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5325 must be a function or a pointer-to-function type, as specified
5326 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5327 and check that the resulting function has external linkage. */
5329 static tree
5331 tsubst_flags_t complain)
5332 {
5335 linkage_kind linkage;
5347 /* [temp.arg.nontype]/1
5349 A template-argument for a non-type, non-template template-parameter
5350 shall be one of:
5351 [...]
5352 -- the address of an object or function with external [C++11: or
5353 internal] linkage. */
5356 {
5358 {
5364 else
5367 }
5369 }
5373 {
5375 {
5380 else
5384 }
5386 }
5389 }
5391 /* Subroutine of convert_nontype_argument.
5392 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5393 Emit an error otherwise. */
5395 static bool
5397 tsubst_flags_t complain)
5398 {
5409 {
5413 }
5415 }
5417 /* Returns TRUE iff the address of OP is value-dependent.
5419 14.6.2.4 [temp.dep.temp]:
5420 A non-integral non-type template-argument is dependent if its type is
5421 dependent or it has either of the following forms
5422 qualified-id
5423 & qualified-id
5424 and contains a nested-name-specifier which specifies a class-name that
5425 names a dependent type.
5427 We generalize this to just say that the address of a member of a
5428 dependent class is value-dependent; the above doesn't cover the
5429 address of a static data member named with an unqualified-id. */
5431 static bool
5433 {
5434 /* We could use get_inner_reference here, but there's no need;
5435 this is only relevant for template non-type arguments, which
5436 can only be expressed as &id-expression. */
5438 {
5442 }
5445 }
5447 /* The next set of functions are used for providing helpful explanatory
5448 diagnostics for failed overload resolution. Their messages should be
5449 indented by two spaces for consistency with the messages in
5450 call.c */
5452 static int
5454 {
5456 }
5458 static int
5460 {
5465 }
5467 static int
5469 {
5471 }
5473 static int
5475 {
5481 }
5483 static int
5485 {
5489 }
5491 static int
5493 {
5496 " template parameter %qD is not a parameter pack, but "
5500 }
5502 static int
5504 {
5507 " template argument %qE does not match "
5511 }
5513 static int
5515 {
5519 }
5521 static int
5523 {
5529 }
5531 static int
5533 {
5535 {
5540 else
5542 " deduced conflicting values for non-type parameter "
5544 }
5546 }
5548 static int
5550 {
5553 " variable-sized array type %qT is not "
5555 arg);
5557 }
5559 static int
5561 {
5565 arg);
5567 }
5569 static int
5571 {
5573 {
5579 else
5584 }
5586 }
5588 static int
5590 {
5592 }
5594 static int
5597 {
5599 }
5601 static int
5604 {
5610 }
5612 static int
5615 {
5618 {
5626 }
5628 }
5630 static int
5632 {
5635 " template parameters of a template template argument are "
5638 }
5640 static int
5642 {
5648 }
5650 static int
5652 {
5657 }
5659 static int
5661 {
5665 arg);
5667 }
5669 /* Attempt to convert the non-type template parameter EXPR to the
5670 indicated TYPE. If the conversion is successful, return the
5671 converted value. If the conversion is unsuccessful, return
5672 NULL_TREE if we issued an error message, or error_mark_node if we
5673 did not. We issue error messages for out-and-out bad template
5674 parameters, but not simply because the conversion failed, since we
5675 might be just trying to do argument deduction. Both TYPE and EXPR
5676 must be non-dependent.
5678 The conversion follows the special rules described in
5679 [temp.arg.nontype], and it is much more strict than an implicit
5680 conversion.
5682 This function is called twice for each template argument (see
5683 lookup_template_class for a more accurate description of this
5684 problem). This means that we need to handle expressions which
5685 are not valid in a C++ source, but can be created from the
5686 first call (for instance, casts to perform conversions). These
5687 hacks can go away after we fix the double coercion problem. */
5689 static tree
5691 {
5692 tree expr_type;
5694 /* Detect immediately string literals as invalid non-type argument.
5695 This special-case is not needed for correctness (we would easily
5696 catch this later), but only to provide better diagnostic for this
5697 common user mistake. As suggested by DR 100, we do not mention
5698 linkage issues in the diagnostic as this is not the point. */
5699 /* FIXME we're making this OK. */
5701 {
5707 }
5709 /* Add the ADDR_EXPR now for the benefit of
5710 value_dependent_expression_p. */
5713 {
5717 }
5719 /* If we are in a template, EXPR may be non-dependent, but still
5720 have a syntactic, rather than semantic, form. For example, EXPR
5721 might be a SCOPE_REF, rather than the VAR_DECL to which the
5722 SCOPE_REF refers. Preserving the qualifying scope is necessary
5723 so that access checking can be performed when the template is
5724 instantiated -- but here we need the resolved form so that we can
5725 convert the argument. */
5736 else
5739 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5740 to a non-type argument of "nullptr". */
5744 /* In C++11, integral or enumeration non-type template arguments can be
5745 arbitrary constant expressions. Pointer and pointer to
5746 member arguments can be general constant expressions that evaluate
5747 to a null value, but otherwise still need to be of a specific form. */
5749 {
5751 /* A PTRMEM_CST is already constant, and a valid template
5752 argument for a parameter of pointer to member type, we just want
5753 to leave it in that form rather than lower it to a
5758 {
5763 }
5764 }
5766 /* HACK: Due to double coercion, we can get a
5767 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5768 which is the tree that we built on the first call (see
5769 below when coercing to reference to object or to reference to
5770 function). We just strip everything and get to the arg.
5771 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5772 for examples. */
5774 {
5780 {
5781 /* ??? Maybe we could use convert_from_reference here, but we
5782 would need to relax its constraints because the NOP_EXPR
5783 could actually change the type to something more cv-qualified,
5784 and this is not folded by convert_from_reference. */
5789 && (same_type_ignoring_top_level_qualifiers_p
5792 {
5795 }
5796 }
5797 }
5799 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5800 parameter is a pointer to object, through decay and
5801 qualification conversion. Let's strip everything. */
5803 {
5808 {
5809 /* Skip the ADDR_EXPR only if it is part of the decay for
5810 an array. Otherwise, it is part of the original argument
5811 in the source code. */
5816 }
5817 }
5819 /* [temp.arg.nontype]/5, bullet 1
5821 For a non-type template-parameter of integral or enumeration type,
5822 integral promotions (_conv.prom_) and integral conversions
5823 (_conv.integral_) are applied. */
5825 {
5834 /* Notice that there are constant expressions like '4 % 0' which
5835 do not fold into integer constants. */
5837 {
5839 {
5850 /* else cxx_constant_value complained but gave us
5851 a real constant, so go ahead. */
5853 }
5854 else
5856 }
5858 /* Avoid typedef problems. */
5861 }
5862 /* [temp.arg.nontype]/5, bullet 2
5864 For a non-type template-parameter of type pointer to object,
5865 qualification conversions (_conv.qual_) and the array-to-pointer
5866 conversion (_conv.array_) are applied. */
5868 {
5869 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5871 A template-argument for a non-type, non-template template-parameter
5872 shall be one of: [...]
5874 -- the name of a non-type template-parameter;
5875 -- the address of an object or function with external linkage, [...]
5876 expressed as "& id-expression" where the & is optional if the name
5877 refers to a function or array, or if the corresponding
5878 template-parameter is a reference.
5880 Here, we do not care about functions, as they are invalid anyway
5881 for a parameter of type pointer-to-object. */
5884 /* Non-type template parameters are OK. */
5885 ;
5890 {
5892 {
5895 "because %qD is a variable, not the address of "
5898 }
5900 {
5906 }
5907 /* Other values, like integer constants, might be valid
5908 non-type arguments of some other type. */
5910 }
5911 else
5912 {
5913 tree decl;
5918 {
5923 }
5925 {
5931 }
5933 {
5938 }
5939 }
5948 }
5949 /* [temp.arg.nontype]/5, bullet 3
5951 For a non-type template-parameter of type reference to object, no
5952 conversions apply. The type referred to by the reference may be more
5953 cv-qualified than the (otherwise identical) type of the
5954 template-argument. The template-parameter is bound directly to the
5955 template-argument, which must be an lvalue. */
5957 {
5959 expr_type))
5963 {
5968 }
5971 {
5976 }
5978 /* [temp.arg.nontype]/1
5980 A template-argument for a non-type, non-template template-parameter
5981 shall be one of: [...]
5983 -- the address of an object or function with external linkage. */
5986 {
5989 {
5992 "because a reference variable does not have a constant "
5995 }
5996 }
5999 {
6005 }
6008 {
6014 }
6017 }
6018 /* [temp.arg.nontype]/5, bullet 4
6020 For a non-type template-parameter of type pointer to function, only
6021 the function-to-pointer conversion (_conv.func_) is applied. If the
6022 template-argument represents a set of overloaded functions (or a
6023 pointer to such), the matching function is selected from the set
6024 (_over.over_). */
6026 {
6027 /* If the argument is a template-id, we might not have enough
6028 context information to decay the pointer. */
6030 {
6034 }
6037 /* Null pointer values are OK in C++11. */
6043 }
6044 /* [temp.arg.nontype]/5, bullet 5
6046 For a non-type template-parameter of type reference to function, no
6047 conversions apply. If the template-argument represents a set of
6048 overloaded functions, the matching function is selected from the set
6049 (_over.over_). */
6051 {
6053 {
6055 {
6060 }
6062 }
6069 }
6070 /* [temp.arg.nontype]/5, bullet 6
6072 For a non-type template-parameter of type pointer to member function,
6073 no conversions apply. If the template-argument represents a set of
6074 overloaded member functions, the matching member function is selected
6075 from the set (_over.over_). */
6077 {
6082 /* [temp.arg.nontype] bullet 1 says the pointer to member
6083 expression must be a pointer-to-member constant. */
6087 /* There is no way to disable standard conversions in
6088 resolve_address_of_overloaded_function (called by
6089 instantiate_type). It is possible that the call succeeded by
6090 converting &B::I to &D::I (where B is a base of D), so we need
6091 to reject this conversion here.
6093 Actually, even if there was a way to disable standard conversions,
6094 it would still be better to reject them here so that we can
6095 provide a superior diagnostic. */
6097 {
6099 {
6103 /* If we are just one standard conversion off, explain. */
6107 }
6109 }
6110 }
6111 /* [temp.arg.nontype]/5, bullet 7
6113 For a non-type template-parameter of type pointer to data member,
6114 qualification conversions (_conv.qual_) are applied. */
6116 {
6117 /* [temp.arg.nontype] bullet 1 says the pointer to member
6118 expression must be a pointer-to-member constant. */
6125 }
6127 {
6129 {
6134 }
6136 }
6137 /* A template non-type parameter must be one of the above. */
6138 else
6141 /* Sanity check: did we actually convert the argument to the
6142 right type? */
6146 }
6148 /* Subroutine of coerce_template_template_parms, which returns 1 if
6149 PARM_PARM and ARG_PARM match using the rule for the template
6150 parameters of template template parameters. Both PARM and ARG are
6151 template parameters; the rest of the arguments are the same as for
6152 coerce_template_template_parms.
6153 */
6154 static int
6156 tree arg,
6157 tsubst_flags_t complain,
6158 tree in_decl,
6159 tree outer_args)
6160 {
6169 {
6171 /* We encounter instantiations of templates like
6172 template <template <template <class> class> class TT>
6173 class C; */
6174 {
6181 }
6182 /* Fall through. */
6187 /* Argument is a parameter pack but parameter is not. */
6192 /* The tsubst call is used to handle cases such as
6194 template <int> class C {};
6195 template <class T, template <T> class TT> class D {};
6196 D<int, C> d;
6198 i.e. the parameter list of TT depends on earlier parameters. */
6200 && !same_type_p
6207 /* Argument is a parameter pack but parameter is not. */
6214 }
6217 }
6220 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6221 template template parameters. Both PARM_PARMS and ARG_PARMS are
6222 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6223 or PARM_DECL.
6225 Consider the example:
6226 template <class T> class A;
6227 template<template <class U> class TT> class B;
6229 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6230 the parameters to A, and OUTER_ARGS contains A. */
6232 static int
6234 tree arg_parms,
6235 tsubst_flags_t complain,
6236 tree in_decl,
6237 tree outer_args)
6238 {
6249 /* Determine whether we have a parameter pack at the end of the
6250 template template parameter's template parameter list. */
6252 {
6259 {
6273 }
6274 }
6280 /* Check all of the template parameters except the parameter pack at
6281 the end (if any). */
6283 {
6292 outer_args))
6295 }
6298 {
6299 /* Check each of the template parameters in the template
6300 argument against the template parameter pack at the end of
6301 the template template parameter. */
6308 {
6315 outer_args))
6317 }
6318 }
6321 }
6323 /* Verifies that the deduced template arguments (in TARGS) for the
6324 template template parameters (in TPARMS) represent valid bindings,
6325 by comparing the template parameter list of each template argument
6326 to the template parameter list of its corresponding template
6327 template parameter, in accordance with DR150. This
6328 routine can only be called after all template arguments have been
6329 deduced. It will return TRUE if all of the template template
6330 parameter bindings are okay, FALSE otherwise. */
6331 bool
6333 {
6337 /* We're dealing with template parms in this process. */
6343 {
6348 {
6353 {
6354 /* Look inside the argument pack. */
6357 }
6360 {
6364 /* Extract the next argument from the argument
6365 pack. */
6369 /* Look at the pattern of the pack expansion. */
6372 /* Extract the template parameters from the template
6373 argument. */
6379 /* Verify that we can coerce the template template
6380 parameters from the template argument to the template
6381 parameter. This requires an exact match. */
6383 && !coerce_template_template_parms
6385 targ_parms,
6386 tf_none,
6387 tparm,
6388 targs))
6389 {
6392 }
6393 }
6394 }
6395 }
6397 out:
6401 }
6403 /* Since type attributes aren't mangled, we need to strip them from
6404 template type arguments. */
6406 static tree
6408 {
6409 tree mv;
6416 {
6421 }
6423 }
6425 /* Convert the indicated template ARG as necessary to match the
6426 indicated template PARM. Returns the converted ARG, or
6427 error_mark_node if the conversion was unsuccessful. Error and
6428 warning messages are issued under control of COMPLAIN. This
6429 conversion is for the Ith parameter in the parameter list. ARGS is
6430 the full set of template arguments deduced so far. */
6432 static tree
6434 tree arg,
6435 tree args,
6436 tsubst_flags_t complain,
6438 tree in_decl)
6439 {
6440 tree orig_arg;
6441 tree val;
6446 {
6447 /* The template argument was the name of some
6448 member function. That's usually
6449 invalid, but static members are OK. In any
6450 case, grab the underlying fields/functions
6451 and issue an error later if required. */
6454 }
6462 /* When determining whether an argument pack expansion is a template,
6463 look at the pattern. */
6467 /* Deal with an injected-class-name used as a template template arg. */
6469 {
6472 {
6482 }
6483 }
6485 is_tmpl_type =
6501 {
6503 {
6507 }
6510 "to refer to a type member of a template parameter, "
6515 typename_type,
6516 complain);
6519 }
6521 {
6523 {
6525 {
6537 else
6540 }
6541 }
6543 }
6545 {
6547 {
6554 else
6557 }
6559 }
6562 {
6564 {
6568 /* The number of argument required is not known yet.
6569 Just accept it for now. */
6571 else
6572 {
6574 tree argparm;
6576 /* Strip alias templates that are equivalent to another
6577 template. */
6583 args))
6584 {
6587 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6588 TEMPLATE_DECL. */
6590 {
6595 }
6596 }
6597 else
6598 {
6600 {
6607 }
6610 }
6611 }
6612 }
6613 else
6615 /* We only form one instance of each template specialization.
6616 Therefore, if we use a non-canonical variant (i.e., a
6617 typedef), any future messages referring to the type will use
6618 the typedef, which is confusing if those future uses do not
6619 themselves also use the typedef. */
6622 }
6623 else
6624 {
6631 {
6634 else
6635 {
6636 /* Not sure if this is reachable, but it doesn't hurt
6637 to be robust. */
6640 }
6641 }
6644 /* We used to call digest_init here. However, digest_init
6645 will report errors, which we don't want when complain
6646 is zero. More importantly, digest_init will try too
6647 hard to convert things: for example, `0' should not be
6648 converted to pointer type at this point according to
6649 the standard. Accepting this is not merely an
6650 extension, since deciding whether or not these
6651 conversions can occur is part of determining which
6652 function template to call, or whether a given explicit
6653 argument specification is valid. */
6655 else
6664 {
6665 /* Strip typedefs from the SCOPE_REF. */
6668 complain);
6671 }
6672 }
6675 }
6677 /* Coerces the remaining template arguments in INNER_ARGS (from
6678 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6679 Returns the coerced argument pack. PARM_IDX is the position of this
6680 parameter in the template parameter list. ARGS is the original
6681 template argument list. */
6682 static tree
6685 tree args,
6686 tree inner_args,
6688 tree new_args,
6690 tree in_decl,
6691 tsubst_flags_t complain)
6692 {
6695 tree packed_args;
6696 tree argument_pack;
6703 {
6704 /* When the template parameter is a non-type template parameter pack
6705 or template template parameter pack whose type or template
6706 parameters use parameter packs, we know exactly how many arguments
6707 we are looking for. Build a vector of the instantiated decls for
6708 these template parameters in PACKED_PARMS. */
6709 /* We can't use make_pack_expansion here because it would interpret a
6710 _DECL as a use rather than a declaration. */
6724 /* If we're doing a partial instantiation of a member template,
6725 verify that all of the types used for the non-type
6726 template parameter pack are, in fact, valid for non-type
6727 template parameters. */
6730 {
6733 {
6737 }
6738 }
6741 }
6742 else
6745 /* Convert the remaining arguments, which will be a part of the
6746 parameter pack "parm". */
6748 {
6754 {
6755 /* Once we've packed as many args as we have types, stop. */
6759 /* We don't know how many args we have yet, just
6760 use the unconverted ones for now. */
6762 else
6764 }
6767 {
6770 }
6771 else
6774 in_decl);
6778 }
6782 {
6787 }
6792 else
6793 {
6798 }
6801 #ifdef ENABLE_CHECKING
6804 #endif
6806 }
6808 /* Returns the number of pack expansions in the template argument vector
6809 ARGS. */
6811 static int
6813 {
6818 {
6822 }
6824 }
6826 /* Convert all template arguments to their appropriate types, and
6827 return a vector containing the innermost resulting template
6828 arguments. If any error occurs, return error_mark_node. Error and
6829 warning messages are issued under control of COMPLAIN.
6831 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6832 for arguments not specified in ARGS. Otherwise, if
6833 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6834 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6835 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6836 ARGS. */
6838 static tree
6840 tree args,
6841 tree in_decl,
6842 tsubst_flags_t complain,
6845 {
6847 tree orig_inner_args;
6848 tree inner_args;
6849 tree new_args;
6850 tree new_inner_args;
6854 /* When used as a boolean value, indicates whether this is a
6855 variadic template parameter list. Since it's an int, we can also
6856 subtract it from nparms to get the number of non-variadic
6857 parameters. */
6862 /* Likewise for parameters with default arguments. */
6870 /* Determine if there are any parameter packs or default arguments. */
6872 {
6880 }
6883 /* If there are no parameters that follow a parameter pack, we need to
6884 expand any argument packs so that we can deduce a parameter pack from
6885 some non-packed args followed by an argument pack, as in variadic85.C.
6886 If there are such parameters, we need to leave argument packs intact
6887 so the arguments are assigned properly. This can happen when dealing
6888 with a nested class inside a partial specialization of a class
6889 template, as in variadic92.C, or when deducing a template parameter pack
6890 from a sub-declarator, as in variadic114.C. */
6894 /* Count any pack expansion args. */
6900 && require_all_args
6901 && !variadic_args_p
6902 && (!use_default_args
6905 {
6907 {
6909 {
6913 }
6914 else
6920 }
6923 }
6924 /* We can't pass a pack expansion to a non-pack parameter of an alias
6925 template (DR 1430). */
6927 && variadic_args_p
6929 {
6931 {
6933 {
6939 {
6944 }
6945 }
6947 found:;
6948 }
6950 }
6952 /* We need to evaluate the template arguments, even though this
6953 template-id may be nested within a "sizeof". */
6962 {
6963 tree arg;
6964 tree parm;
6966 /* Get the Ith template parameter. */
6970 {
6973 }
6975 /* Calculate the next argument. */
6978 else
6983 {
6984 /* Some arguments will be placed in the
6985 template parameter pack PARM. */
6992 {
6993 /* We don't know how many args we have yet, just use the
6994 unconverted (and still packed) ones for now. */
6998 }
7002 /* Store this argument. */
7004 {
7005 lost++;
7006 /* We are done with all of the arguments. */
7008 }
7009 else
7010 {
7013 }
7016 }
7018 {
7020 {
7021 /* "If every valid specialization of a variadic template
7022 requires an empty template parameter pack, the template is
7023 ill-formed, no diagnostic required." So check that the
7024 pattern works with this parameter. */
7029 in_decl);
7031 {
7035 }
7037 /* Recover from missing typename. */
7041 /* We don't know how many args we have yet, just
7042 use the unconverted ones for now. */
7046 }
7047 }
7049 {
7050 /* There must be a default arg in this case. */
7053 /* The position of the first default template argument,
7054 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7055 Record that. */
7059 }
7060 else
7064 {
7067 }
7069 /* This only occurs if there was an error in the template
7070 parameter list itself (which we would already have
7071 reported) that we are trying to recover from, e.g., a class
7072 template with a parameter list such as
7073 template<typename..., typename>. */
7075 else
7081 lost++;
7083 }
7088 {
7090 {
7095 }
7097 }
7102 #ifdef ENABLE_CHECKING
7106 #endif
7109 }
7111 /* Like coerce_template_parms. If PARMS represents all template
7112 parameters levels, this function returns a vector of vectors
7113 representing all the resulting argument levels. Note that in this
7114 case, only the innermost arguments are coerced because the
7115 outermost ones are supposed to have been coerced already.
7117 Otherwise, if PARMS represents only (the innermost) vector of
7118 parameters, this function returns a vector containing just the
7119 innermost resulting arguments. */
7121 static tree
7123 tree args,
7124 tree in_decl,
7125 tsubst_flags_t complain,
7128 {
7131 tree coerced_args;
7134 {
7136 tree level;
7142 {
7143 tree l;
7147 require_all_args,
7148 use_default_args);
7149 else
7156 }
7157 }
7158 else
7161 require_all_args,
7162 use_default_args);
7164 }
7166 /* Returns 1 if template args OT and NT are equivalent. */
7168 static int
7170 {
7177 /* For member templates */
7186 {
7203 }
7205 {
7206 /* We get here probably because we are in the middle of substituting
7207 into the pattern of a pack expansion. In that case the
7208 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7209 interested in. So we want to use the initial pack argument for
7210 the comparison. */
7215 }
7220 else
7222 }
7224 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7225 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7226 NEWARG_PTR with the offending arguments if they are non-NULL. */
7228 static int
7231 {
7244 {
7249 {
7255 }
7256 }
7258 }
7260 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7261 of template arguments. Returns 0 otherwise. */
7263 int
7265 {
7267 }
7269 static void
7271 {
7281 /* We are called both from instantiate_decl, where we've already had a
7282 tinst_level pushed, and instantiate_template, where we haven't.
7283 Compensate. */
7294 else
7303 }
7306 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7307 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7308 documentation for TEMPLATE_ID_EXPR. */
7310 tree
7312 {
7313 tree type;
7321 {
7324 }
7327 {
7329 unknown_type_node,
7331 arglist);
7333 }
7340 }
7342 /* Within the scope of a template class S<T>, the name S gets bound
7343 (in build_self_reference) to a TYPE_DECL for the class, not a
7344 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7345 or one of its enclosing classes, and that type is a template,
7346 return the associated TEMPLATE_DECL. Otherwise, the original
7347 DECL is returned.
7349 Also handle the case when DECL is a TREE_LIST of ambiguous
7350 injected-class-names from different bases. */
7352 tree
7354 {
7358 /* DR 176: A lookup that finds an injected-class-name (10.2
7359 [class.member.lookup]) can result in an ambiguity in certain cases
7360 (for example, if it is found in more than one base class). If all of
7361 the injected-class-names that are found refer to specializations of
7362 the same class template, and if the name is followed by a
7363 template-argument-list, the reference refers to the class template
7364 itself and not a specialization thereof, and is not ambiguous. */
7366 {
7369 {
7375 }
7378 else
7380 }
7386 }
7388 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7389 parameters, find the desired type.
7391 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7393 IN_DECL, if non-NULL, is the template declaration we are trying to
7394 instantiate.
7396 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7397 the class we are looking up.
7399 Issue error and warning messages under control of COMPLAIN.
7401 If the template class is really a local class in a template
7402 function, then the FUNCTION_CONTEXT is the function in which it is
7403 being instantiated.
7405 ??? Note that this function is currently called *twice* for each
7406 template-id: the first time from the parser, while creating the
7407 incomplete type (finish_template_type), and the second type during the
7408 real instantiation (instantiate_template_class). This is surely something
7409 that we want to avoid. It also causes some problems with argument
7410 coercion (see convert_nontype_argument for more information on this). */
7412 static tree
7415 {
7417 tree t;
7420 spec_entry elt;
7421 hashval_t hash;
7424 {
7428 else
7429 {
7436 }
7439 }
7441 {
7444 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7445 an implicit typename for the second A. Deal with it. */
7450 {
7453 }
7454 }
7457 {
7460 }
7462 {
7466 }
7468 {
7471 }
7473 /* Issue an error message if we didn't find a template. */
7475 {
7479 }
7482 /* Make sure it's a user visible template, if it was named by
7483 the user. */
7486 {
7488 {
7492 }
7494 }
7498 /* An alias that just changes the name of a template is equivalent to the
7499 other template, so if any of the arguments are pack expansions, strip
7500 the alias to avoid problems with a pack expansion passed to a non-pack
7501 alias template parameter (DR 1430). */
7506 {
7507 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7508 template arguments */
7510 tree parm;
7511 tree arglist2;
7512 tree outer;
7516 /* Consider an example where a template template parameter declared as
7518 template <class T, class U = std::allocator<T> > class TT
7520 The template parameter level of T and U are one level larger than
7521 of TT. To proper process the default argument of U, say when an
7522 instantiation `TT<int>' is seen, we need to build the full
7523 arguments containing {int} as the innermost level. Outer levels,
7524 available when not appearing as default template argument, can be
7525 obtained from the arguments of the enclosing template.
7527 Suppose that TT is later substituted with std::vector. The above
7528 instantiation is `TT<int, std::allocator<T> >' with TT at
7529 level 1, and T at level 2, while the template arguments at level 1
7530 becomes {std::vector} and the inner level 2 is {int}. */
7536 /* This is an argument of the current template, so we haven't set
7537 DECL_CONTEXT yet. */
7544 complain,
7554 }
7555 else
7556 {
7558 tree gen_tmpl;
7559 tree type_decl;
7567 /* An error occurred while building the template TEMPL, and a
7568 diagnostic has most certainly been emitted for that
7569 already. Let's propagate that error. */
7578 {
7579 /* We've been given an incomplete set of template arguments.
7580 For example, given:
7582 template <class T> struct S1 {
7583 template <class U> struct S2 {};
7584 template <class U> struct S2<U*> {};
7585 };
7587 we will be called with an ARGLIST of `U*', but the
7588 TEMPLATE will be `template <class T> template
7589 <class U> struct S1<T>::S2'. We must fill in the missing
7590 arguments. */
7591 arglist
7593 arglist);
7595 }
7597 /* Now we should have enough arguments. */
7600 /* From here on, we're only interested in the most general
7601 template. */
7603 /* Calculate the BOUND_ARGS. These will be the args that are
7604 actually tsubst'd into the definition to create the
7605 instantiation. */
7607 {
7608 /* We have multiple levels of arguments to coerce, at once. */
7618 {
7619 tree a;
7623 complain,
7626 else
7627 /* Outer levels should have already been coerced. */
7630 /* Don't process further if one of the levels fails. */
7632 {
7633 /* Restore the ARGLIST to its full size. */
7636 }
7640 /* We temporarily reduce the length of the ARGLIST so
7641 that coerce_template_parms will see only the arguments
7642 corresponding to the template parameters it is
7643 examining. */
7645 }
7647 /* Restore the ARGLIST to its full size. */
7651 }
7652 else
7653 arglist
7656 gen_tmpl,
7657 complain,
7662 /* We were unable to bind the arguments. */
7665 /* In the scope of a template class, explicit references to the
7666 template class refer to the type of the template, not any
7667 instantiation of it. For example, in:
7669 template <class T> class C { void f(C<T>); }
7671 the `C<T>' is just the same as `C'. Outside of the
7672 class, however, such a reference is an instantiation. */
7676 /* comp_template_args is expensive, check it last. */
7678 arglist))
7681 /* If we already have this specialization, return it. */
7693 /* If the deduced arguments are invalid, then the binding
7694 failed. */
7698 complain))
7705 {
7710 }
7720 /* Create the type. */
7722 {
7723 /* The user referred to a specialization of an alias
7724 template represented by GEN_TMPL.
7726 [temp.alias]/2 says:
7728 When a template-id refers to the specialization of an
7729 alias template, it is equivalent to the associated
7730 type obtained by substitution of its
7731 template-arguments for the template-parameters in the
7732 type-id of the alias template. */
7735 /* Note that the call above (by indirectly calling
7736 register_specialization in tsubst_decl) registers the
7737 TYPE_DECL representing the specialization of the alias
7738 template. So next time someone substitutes ARGLIST for
7739 the template parms into the alias template (GEN_TMPL),
7740 she'll get that TYPE_DECL back. */
7744 }
7746 {
7748 {
7757 }
7758 else
7759 {
7760 /* We don't want to call start_enum for this type, since
7761 the values for the enumeration constants may involve
7762 template parameters. And, no one should be interested
7763 in the enumeration constants for such a type. */
7766 }
7770 }
7772 {
7779 /* A local class. Make sure the decl gets registered properly. */
7784 /* This instantiation is another name for the primary
7785 template type. Set the TYPE_CANONICAL field
7786 appropriately. */
7789 /* Some of the template arguments require structural
7790 equality testing, so this template class requires
7791 structural equality testing. */
7793 }
7794 else
7797 /* If we called start_enum or pushtag above, this information
7798 will already be set up. */
7800 {
7807 }
7808 else
7812 {
7818 {
7821 }
7822 }
7826 {
7829 {
7832 else
7836 }
7837 }
7839 /* Let's consider the explicit specialization of a member
7840 of a class template specialization that is implicitly instantiated,
7841 e.g.:
7842 template<class T>
7843 struct S
7844 {
7845 template<class U> struct M {}; //#0
7846 };
7848 template<>
7849 template<>
7850 struct S<int>::M<char> //#1
7851 {
7852 int i;
7853 };
7854 [temp.expl.spec]/4 says this is valid.
7856 In this case, when we write:
7857 S<int>::M<char> m;
7859 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7860 the one of #0.
7862 When we encounter #1, we want to store the partial instantiation
7863 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7865 For all cases other than this "explicit specialization of member of a
7866 class template", we just want to store the most general template into
7867 the CLASSTYPE_TI_TEMPLATE of M.
7869 This case of "explicit specialization of member of a class template"
7870 only happens when:
7871 1/ the enclosing class is an instantiation of, and therefore not
7872 the same as, the context of the most general template, and
7873 2/ we aren't looking at the partial instantiation itself, i.e.
7874 the innermost arguments are not the same as the innermost parms of
7875 the most general template.
7877 So it's only when 1/ and 2/ happens that we want to use the partial
7878 instantiation of the member template in lieu of its most general
7879 template. */
7883 /* the enclosing class must be an instantiation... */
7886 {
7887 tree partial_inst_args;
7890 partial_inst_args =
7896 use_partial_inst_tmpl =
7897 /*...and we must not be looking at the partial instantiation
7898 itself. */
7900 partial_inst_args);
7901 }
7904 /* This case is easy; there are no member templates involved. */
7906 else
7907 {
7908 /* This is a full instantiation of a member template. Find
7909 the partial instantiation of which this is an instance. */
7911 /* Temporarily reduce by one the number of levels in the ARGLIST
7912 so as to avoid comparing the last set of arguments. */
7916 /* FOUND is either a proper class type, or an alias
7917 template specialization. In the later case, it's a
7918 TYPE_DECL, resulting from the substituting of arguments
7919 for parameters in the TYPE_DECL of the alias template
7920 done earlier. So be careful while getting the template
7921 of FOUND. */
7925 }
7936 /* Note this use of the partial instantiation so we can check it
7937 later in maybe_process_partial_specialization. */
7944 /* Now that the type has been registered on the instantiations
7945 list, we set up the enumerators. Because the enumeration
7946 constants may involve the enumeration type itself, we make
7947 sure to register the type first, and then create the
7948 constants. That way, doing tsubst_expr for the enumeration
7949 constants won't result in recursive calls here; we'll find
7950 the instantiation and exit above. */
7954 /* If the type makes use of template parameters, the
7955 code that generates debugging information will crash. */
7958 /* Possibly limit visibility based on template args. */
7965 }
7966 }
7968 /* Wrapper for lookup_template_class_1. */
7970 tree
7973 {
7974 tree ret;
7980 }
7982 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST.
7983 If the ARGLIST refers to any template parameters, the type of the
7984 expression is the unknown_type_node since the template-id could
7985 refer to an explicit or partial specialization. */
7987 tree
7989 {
7990 tree type;
7993 else
7996 }
7998 \f
7999 struct pair_fn_data
8000 {
8001 tree_fn_t fn;
8003 /* True when we should also visit template parameters that occur in
8004 non-deduced contexts. */
8007 };
8009 /* Called from for_each_template_parm via walk_tree. */
8011 static tree
8013 {
8026 {
8030 /* Fall through. */
8053 /* Since we're not going to walk subtrees, we have to do this
8054 explicitly here. */
8058 /* Fall through. */
8061 /* Check the return type. */
8066 /* Check the parameter types. Since default arguments are not
8067 instantiated until they are needed, the TYPE_ARG_TYPES may
8068 contain expressions that involve template parameters. But,
8069 no-one should be looking at them yet. And, once they're
8070 instantiated, they don't contain template parameters, so
8071 there's no point in looking at them then, either. */
8072 {
8073 tree parm;
8080 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8081 want walk_tree walking into them itself. */
8083 }
8101 /* Fall through. */
8117 /* Record template parameters such as `T' inside `TT<T>'. */
8121 /* Fall through. */
8133 /* A template template parameter is encountered. */
8139 /* Already substituted template template parameter */
8162 /* If there's no type, then this thing must be some expression
8163 involving template parameters. */
8185 }
8187 /* We didn't find any template parameters we liked. */
8189 }
8191 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8192 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8193 call FN with the parameter and the DATA.
8194 If FN returns nonzero, the iteration is terminated, and
8195 for_each_template_parm returns 1. Otherwise, the iteration
8196 continues. If FN never returns a nonzero value, the value
8197 returned by for_each_template_parm is 0. If FN is NULL, it is
8198 considered to be the function which always returns 1.
8200 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8201 parameters that occur in non-deduced contexts. When false, only
8202 visits those template parameters that can be deduced. */
8204 static int
8208 {
8212 /* Set up. */
8217 /* Walk the tree. (Conceptually, we would like to walk without
8218 duplicates, but for_each_template_parm_r recursively calls
8219 for_each_template_parm, so we would need to reorganize a fair
8220 bit to use walk_tree_without_duplicates, so we keep our own
8221 visited list.) */
8224 else
8227 for_each_template_parm_r,
8231 /* Clean up. */
8233 {
8236 }
8239 }
8241 /* Returns true if T depends on any template parameter. */
8243 int
8245 {
8272 else
8273 {
8276 }
8281 }
8283 /* Returns true iff current_function_decl is an incompletely instantiated
8284 template. Useful instead of processing_template_decl because the latter
8285 is set to 0 during fold_non_dependent_expr. */
8287 bool
8289 {
8298 }
8300 /* Returns true if T depends on any template parameter with level LEVEL. */
8302 int
8304 {
8307 }
8309 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8310 ill-formed translation unit, i.e. a variable or function that isn't
8311 usable in a constant expression. */
8315 {
8319 }
8321 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8322 neglectable and instantiated from within an erroneous instantiation. */
8324 static bool
8326 {
8337 }
8345 /* We're starting to instantiate D; record the template instantiation context
8346 for diagnostics and to restore it later. */
8348 int
8350 {
8354 {
8360 else
8368 }
8370 /* If the current instantiation caused problems, don't let it instantiate
8371 anything else. Do allow deduction substitution and decls usable in
8372 constant expressions. */
8389 }
8391 /* We're done instantiating this template; return to the instantiation
8392 context. */
8394 void
8396 {
8397 /* Restore the filename and line number stashed away when we started
8398 this instantiation. */
8402 }
8404 /* We're instantiating a deferred template; restore the template
8405 instantiation context in which the instantiation was requested, which
8406 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8408 static tree
8410 {
8422 }
8424 /* Returns the TINST_LEVEL which gives the original instantiation
8425 context. */
8429 {
8435 }
8437 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8438 vector of template arguments, as for tsubst.
8440 Returns an appropriate tsubst'd friend declaration. */
8442 static tree
8444 {
8445 tree new_friend;
8450 /* This was a friend declared with an explicit template
8451 argument list, e.g.:
8453 friend void f<>(T);
8455 to indicate that f was a template instantiation, not a new
8456 function declaration. Now, we have to figure out what
8457 instantiation of what template. */
8458 {
8460 tree new_args;
8461 tree tmpl;
8464 /* Friend functions are looked up in the containing namespace scope.
8465 We must enter that scope, to avoid finding member functions of the
8466 current class with same name. */
8481 tsk_none);
8483 }
8487 /* The NEW_FRIEND will look like an instantiation, to the
8488 compiler, but is not an instantiation from the point of view of
8489 the language. For example, we might have had:
8491 template <class T> struct S {
8492 template <class U> friend void f(T, U);
8493 };
8495 Then, in S<int>, template <class U> void f(int, U) is not an
8496 instantiation of anything. */
8502 {
8506 }
8508 /* The mangled name for the NEW_FRIEND is incorrect. The function
8509 is not a template instantiation and should not be mangled like
8510 one. Therefore, we forget the mangling here; we'll recompute it
8511 later if we need it. */
8513 {
8516 }
8519 {
8520 tree old_decl;
8521 tree new_friend_template_info;
8522 tree new_friend_result_template_info;
8523 tree ns;
8526 /* We must save some information from NEW_FRIEND before calling
8527 duplicate decls since that function will free NEW_FRIEND if
8528 possible. */
8530 new_friend_is_defn =
8535 {
8536 /* This declaration is a `primary' template. */
8539 new_friend_result_template_info
8541 }
8542 else
8545 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8549 /* Inside pushdecl_namespace_level, we will push into the
8550 current namespace. However, the friend function should go
8551 into the namespace of the template. */
8561 {
8562 /* This new friend declaration matched an existing
8563 declaration. For example, given:
8565 template <class T> void f(T);
8566 template <class U> class C {
8567 template <class T> friend void f(T) {}
8568 };
8570 the friend declaration actually provides the definition
8571 of `f', once C has been instantiated for some type. So,
8572 old_decl will be the out-of-class template declaration,
8573 while new_friend is the in-class definition.
8575 But, if `f' was called before this point, the
8576 instantiation of `f' will have DECL_TI_ARGS corresponding
8577 to `T' but not to `U', references to which might appear
8578 in the definition of `f'. Previously, the most general
8579 template for an instantiation of `f' was the out-of-class
8580 version; now it is the in-class version. Therefore, we
8581 run through all specialization of `f', adding to their
8582 DECL_TI_ARGS appropriately. In particular, they need a
8583 new set of outer arguments, corresponding to the
8584 arguments for this class instantiation.
8586 The same situation can arise with something like this:
8588 friend void f(int);
8589 template <class T> class C {
8590 friend void f(T) {}
8591 };
8593 when `C<int>' is instantiated. Now, `f(int)' is defined
8594 in the class. */
8597 /* On the other hand, if the in-class declaration does
8598 *not* provide a definition, then we don't want to alter
8599 existing definitions. We can just leave everything
8600 alone. */
8601 ;
8602 else
8603 {
8607 /* Overwrite whatever template info was there before, if
8608 any, with the new template information pertaining to
8609 the declaration. */
8613 {
8614 /* We should have called reregister_specialization in
8615 duplicate_decls. */
8620 /* Instantiate it if the global has already been used. */
8624 }
8625 else
8626 {
8627 tree t;
8629 /* Indicate that the old function template is a partial
8630 instantiation. */
8638 /* Reassign any specializations already in the hash table
8639 to the new more general template, and add the
8640 additional template args. */
8644 {
8646 spec_entry elt;
8658 register_specialization
8661 }
8663 }
8664 }
8666 /* The information from NEW_FRIEND has been merged into OLD_DECL
8667 by duplicate_decls. */
8669 }
8670 }
8671 else
8672 {
8676 /* In the code
8677 template <class T> class C {
8678 template <class U> friend void C1<U>::f (); // case 1
8679 friend void C2<T>::f (); // case 2
8680 };
8681 we only need to make sure CONTEXT is a complete type for
8682 case 2. To distinguish between the two cases, we note that
8683 CONTEXT of case 1 remains dependent type after tsubst while
8684 this isn't true for case 2. */
8694 {
8696 /* do_friend adds the TEMPLATE_DECL for any member friend
8697 template even if it isn't a member template, i.e.
8698 template <class T> friend A<T>::f();
8699 Look through it in that case. */
8703 /* Check to see that the declaration is really present, and,
8704 possibly obtain an improved declaration. */
8709 }
8710 }
8713 }
8715 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8716 template arguments, as for tsubst.
8718 Returns an appropriate tsubst'd friend type or error_mark_node on
8719 failure. */
8721 static tree
8723 {
8724 tree friend_type;
8725 tree tmpl;
8726 tree context;
8729 {
8732 }
8737 {
8740 else
8742 }
8744 /* Look for a class template declaration. We look for hidden names
8745 because two friend declarations of the same template are the
8746 same. For example, in:
8748 struct A {
8749 template <typename> friend class F;
8750 };
8751 template <typename> struct B {
8752 template <typename> friend class F;
8753 };
8755 both F templates are the same. */
8759 /* But, if we don't find one, it might be because we're in a
8760 situation like this:
8762 template <class T>
8763 struct S {
8764 template <class U>
8765 friend struct S;
8766 };
8768 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8769 for `S<int>', not the TEMPLATE_DECL. */
8771 {
8774 }
8777 {
8778 /* The friend template has already been declared. Just
8779 check to see that the declarations match, and install any new
8780 default parameters. We must tsubst the default parameters,
8781 of course. We only need the innermost template parameters
8782 because that is all that redeclare_class_template will look
8783 at. */
8786 {
8787 tree parms;
8788 location_t saved_input_location;
8797 }
8800 }
8801 else
8802 {
8803 /* The friend template has not already been declared. In this
8804 case, the instantiation of the template class will cause the
8805 injection of this template into the global scope. */
8810 /* The new TMPL is not an instantiation of anything, so we
8811 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8812 the new type because that is supposed to be the corresponding
8813 template decl, i.e., TMPL. */
8820 /* Inject this template into the global scope. */
8822 }
8825 {
8828 else
8830 }
8833 }
8835 /* Returns zero if TYPE cannot be completed later due to circularity.
8836 Otherwise returns one. */
8838 static int
8840 {
8850 else
8852 }
8856 /* Apply any attributes which had to be deferred until instantiation
8857 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8858 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8860 static void
8863 {
8865 tree t;
8870 {
8874 }
8877 {
8881 }
8882 else
8886 {
8891 {
8894 {
8901 {
8908 clauses
8912 else
8914 }
8915 /* If the first attribute argument is an identifier, don't
8916 pass it through tsubst. Attributes like mode, format,
8917 cleanup and several target specific attributes expect it
8918 unmodified. */
8921 {
8922 tree chain
8924 in_decl,
8929 chain);
8930 }
8931 else
8937 }
8938 else
8940 }
8943 }
8944 }
8946 /* Perform (or defer) access check for typedefs that were referenced
8947 from within the template TMPL code.
8948 This is a subroutine of instantiate_decl and instantiate_class_template.
8949 TMPL is the template to consider and TARGS is the list of arguments of
8950 that template. */
8952 static void
8954 {
8955 location_t saved_location;
8966 {
8978 /* Make access check error messages point to the location
8979 of the use of the typedef. */
8983 tf_warning_or_error);
8984 }
8986 }
8988 static tree
8990 {
8992 tree typedecl;
8993 tree pbinfo;
8994 tree base_list;
8996 tree fn_context;
9005 /* Figure out which template is being instantiated. */
9009 /* Determine what specialization of the original template to
9010 instantiate. */
9013 {
9016 }
9018 {
9019 /* This TYPE is actually an instantiation of a partial
9020 specialization. We replace the innermost set of ARGS with
9021 the arguments appropriate for substitution. For example,
9022 given:
9024 template <class T> struct S {};
9025 template <class T> struct S<T*> {};
9027 and supposing that we are instantiating S<int*>, ARGS will
9028 presently be {int*} -- but we need {int}. */
9031 }
9032 else
9033 {
9036 }
9038 /* If the template we're instantiating is incomplete, then clearly
9039 there's nothing we can do. */
9043 /* If we've recursively instantiated too many templates, stop. */
9047 /* Now we're really doing the instantiation. Mark the type as in
9048 the process of being defined. */
9051 /* We may be in the middle of deferred access check. Disable
9052 it now. */
9056 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9061 /* Use #pragma pack from the template context. */
9067 /* Set the input location to the most specialized template definition.
9068 This is needed if tsubsting causes an error. */
9080 {
9083 /* Adjust visibility for template arguments. */
9085 }
9091 /* We should never instantiate a nested class before its enclosing
9092 class; we need to look up the nested class by name before we can
9093 instantiate it, and that lookup should instantiate the enclosing
9094 class. */
9100 {
9101 tree pbase_binfo;
9102 tree pushed_scope;
9105 /* We must enter the scope containing the type, as that is where
9106 the accessibility of types named in dependent bases are
9107 looked up from. */
9110 /* Substitute into each of the bases to determine the actual
9111 basetypes. */
9113 {
9114 tree base;
9120 {
9121 expanded_bases =
9128 }
9131 {
9133 /* Extract the already-expanded base class. */
9135 else
9136 /* Substitute to figure out the base class. */
9138 NULL_TREE);
9146 }
9147 }
9149 /* The list is now in reverse order; correct that. */
9154 }
9155 /* Now call xref_basetypes to set up all the base-class
9156 information. */
9164 /* Now that our base classes are set up, enter the scope of the
9165 class, so that name lookups into base classes, etc. will work
9166 correctly. This is precisely analogous to what we do in
9167 begin_class_definition when defining an ordinary non-template
9168 class, except we also need to push the enclosing classes. */
9171 /* Now members are processed in the order of declaration. */
9174 {
9178 {
9180 {
9181 /* Build new CLASSTYPE_NESTED_UTDS. */
9183 tree newtag;
9189 /* If the member is a class template, then -- even after
9190 substitution -- there may be dependent types in the
9191 template argument list for the class. We increment
9192 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9193 that function will assume that no types are dependent
9194 when outside of a template. */
9204 {
9208 /* Unfortunately, lookup_template_class sets
9209 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9210 instantiation (i.e., for the type of a member
9211 template class nested within a template class.)
9212 This behavior is required for
9213 maybe_process_partial_specialization to work
9214 correctly, but is not accurate in this case;
9215 the TAG is not an instantiation of anything.
9216 (The corresponding TEMPLATE_DECL is an
9217 instantiation, but the TYPE is not.) */
9220 /* Now, we call pushtag to put this NEWTAG into the scope of
9221 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9222 pushtag calling push_template_decl. We don't have to do
9223 this for enums because it will already have been done in
9224 tsubst_enum. */
9228 }
9229 }
9231 {
9232 /* Build new TYPE_METHODS. */
9233 tree r;
9242 /* Instantiate members marked with attribute used. */
9248 }
9251 /* A closure type for a lambda in a default argument for a
9252 member template. Ignore it; it will be instantiated with
9254 else
9255 {
9256 /* Build new TYPE_FIELDS. */
9258 {
9259 tree condition;
9262 condition =
9272 }
9274 {
9275 tree r;
9279 /* The file and line for this declaration, to
9280 assist in error message reporting. Since we
9281 called push_tinst_level above, we don't need to
9282 restore these. */
9292 {
9293 /* A capture pack became multiple fields. */
9296 }
9299 {
9303 {
9304 /* In [temp.inst]:
9306 [t]he initialization (and any associated
9307 side-effects) of a static data member does
9308 not occur unless the static data member is
9309 itself used in a way that requires the
9310 definition of the static data member to
9311 exist.
9313 Therefore, we do not substitute into the
9314 initialized for the static data member here. */
9315 finish_static_data_member_decl
9321 /* Instantiate members marked with attribute used. */
9324 }
9326 {
9327 /* Determine whether R has a valid type and can be
9328 completed later. If R is invalid, then its type
9329 is replaced by error_mark_node. */
9335 {
9338 }
9339 }
9341 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9342 such a thing will already have been added to the field
9343 list by tsubst_enum in finish_member_declaration in the
9344 CLASSTYPE_NESTED_UTDS case above. */
9348 {
9351 }
9352 }
9353 }
9354 }
9355 }
9356 else
9357 {
9360 {
9361 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9367 {
9368 /* template <class T> friend class C; */
9371 }
9373 {
9374 /* template <class T> friend class C::D; */
9380 }
9383 {
9384 /* This could be either
9386 friend class T::C;
9388 when dependent_type_p is false or
9390 template <class U> friend class T::C;
9392 otherwise. */
9395 /* Bump processing_template_decl for correct
9396 dependent_type_p calculation. */
9401 }
9404 {
9405 /* friend class C;
9407 where C hasn't been declared yet. Let's lookup name
9408 from namespace scope directly, bypassing any name that
9409 come from dependent base class. */
9412 /* The call to xref_tag_from_type does injection for friend
9413 classes. */
9415 friend_type =
9419 }
9421 /* friend class C<T>; */
9424 /* Otherwise it's
9426 friend class C;
9428 where C is already declared or
9430 friend class C<int>;
9432 We don't have to do anything in these cases. */
9435 /* Trick make_friend_class into realizing that the friend
9436 we're adding is a template, not an ordinary class. It's
9437 important that we use make_friend_class since it will
9438 perform some error-checking and output cross-reference
9439 information. */
9447 }
9448 else
9449 {
9450 /* Build new DECL_FRIENDLIST. */
9451 tree r;
9453 /* The file and line for this declaration, to
9454 assist in error message reporting. Since we
9455 called push_tinst_level above, we don't need to
9456 restore these. */
9460 {
9463 }
9468 {
9471 }
9472 }
9473 }
9474 }
9477 {
9480 {
9485 /* We need to instantiate the capture list from the template
9486 after we've instantiated the closure members, but before we
9487 consider adding the conversion op. Also keep any captures
9488 that may have been added during instantiation of the op(). */
9490 tree tmpl_cap
9499 }
9500 else
9502 }
9504 /* Set the file and line number information to whatever is given for
9505 the class itself. This puts error messages involving generated
9506 implicit functions at a predictable point, and the same point
9507 that would be used for non-template classes. */
9514 /* We don't instantiate default arguments for member functions. 14.7.1:
9516 The implicit instantiation of a class template specialization causes
9517 the implicit instantiation of the declarations, but not of the
9518 definitions or default arguments, of the class member functions,
9519 member classes, static data members and member templates.... */
9521 /* Some typedefs referenced from within the template code need to be access
9522 checked at template instantiation time, i.e now. These types were
9523 added to the template at parsing time. Let's get those and perform
9524 the access checks then. */
9534 /* The vtable for a template class can be emitted in any translation
9535 unit in which the class is instantiated. When there is no key
9536 method, however, finish_struct_1 will already have added TYPE to
9537 the keyed_classes list. */
9542 }
9544 /* Wrapper for instantiate_class_template_1. */
9546 tree
9548 {
9549 tree ret;
9554 }
9556 static tree
9558 {
9559 tree r;
9565 else
9566 {
9573 }
9575 }
9577 /* Given a function parameter pack TMPL_PARM and some function parameters
9578 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9579 and set *SPEC_P to point at the next point in the list. */
9581 static tree
9583 {
9584 /* Collect all of the extra "packed" parameters into an
9585 argument pack. */
9586 tree parmvec;
9587 tree parmtypevec;
9598 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9603 {
9606 }
9608 /* Build the argument packs. */
9615 }
9617 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9618 NONTYPE_ARGUMENT_PACK. */
9620 static tree
9622 {
9624 }
9626 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9627 pack expansion. */
9629 static bool
9631 {
9636 }
9639 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9641 static tree
9643 {
9650 }
9652 /* This is a subroutine of tsubst_pack_expansion.
9654 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9655 mechanism to store the (non complete list of) arguments of the
9656 substitution and return a non substituted pack expansion, in order
9657 to wait for when we have enough arguments to really perform the
9658 substitution. */
9660 static bool
9664 {
9665 /* If one pack has an expansion and another pack has a normal
9666 argument or if one pack has an empty argument and an another
9667 one hasn't then tsubst_pack_expansion cannot perform the
9668 substitution and need to fall back on the
9669 PACK_EXPANSION_EXTRA mechanism. */
9677 {
9680 parm_pack;
9682 {
9687 else
9689 }
9693 }
9695 }
9697 /* [temp.variadic]/6 says that:
9699 The instantiation of a pack expansion [...]
9700 produces a list E1,E2, ..., En, where N is the number of elements
9701 in the pack expansion parameters.
9703 This subroutine of tsubst_pack_expansion produces one of these Ei.
9705 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9706 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9707 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9708 INDEX is the index 'i' of the element Ei to produce. ARGS,
9709 COMPLAIN, and IN_DECL are the same parameters as for the
9710 tsubst_pack_expansion function.
9712 The function returns the resulting Ei upon successful completion,
9713 or error_mark_node.
9715 Note that this function possibly modifies the ARGS parameter, so
9716 it's the responsibility of the caller to restore it. */
9718 static tree
9720 tree parm_packs,
9722 tree args /* This parm gets
9724 tsubst_flags_t complain,
9725 tree in_decl)
9726 {
9727 tree t;
9730 /* For each parameter pack, change the substitution of the parameter
9731 pack to the ith argument in its argument pack, then expand the
9732 pattern. */
9734 {
9739 ith_elem_is_expansion |=
9742 /* Select the Ith argument from the pack. */
9745 {
9747 {
9751 }
9752 else
9754 }
9755 else
9756 {
9761 {
9763 /* Update the corresponding argument. */
9765 }
9766 else
9767 /* Re-use the ARGUMENT_PACK_SELECT. */
9769 }
9771 }
9773 /* Substitute into the PATTERN with the (possibly altered)
9774 arguments. */
9776 /* Expanding a fixed parameter pack from
9777 coerce_template_parameter_pack. */
9782 else
9785 /* If the Ith argument pack element is a pack expansion, then
9786 the Ith element resulting from the substituting is going to
9787 be a pack expansion as well. */
9792 }
9794 /* Substitute ARGS into T, which is an pack expansion
9795 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9796 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9797 (if only a partial substitution could be performed) or
9798 ERROR_MARK_NODE if there was an error. */
9799 tree
9801 tree in_decl)
9802 {
9803 tree pattern;
9807 tree result;
9815 /* Add in any args remembered from an earlier partial instantiation. */
9820 /* Determine the argument packs that will instantiate the parameter
9821 packs used in the expansion expression. While we're at it,
9822 compute the number of arguments to be expanded and make sure it
9823 is consistent. */
9826 {
9833 {
9837 else
9840 }
9842 {
9845 else
9846 {
9847 /* We can't rely on local_specializations for a parameter
9848 name used later in a function declaration (such as in a
9849 late-specified return type). Even if it exists, it might
9850 have the wrong value for a recursive call. Just make a
9851 dummy decl, since it's only used for its type. */
9854 /* Partial instantiation of the parm_pack, we can't build
9855 up an argument pack yet. */
9857 else
9860 }
9861 }
9864 else
9865 {
9871 }
9878 /* This can only happen if we forget to expand an argument
9879 pack somewhere else. Just return an error, silently. */
9880 {
9884 }
9887 {
9891 /* Don't bother trying to do a partial substitution with
9892 incomplete packs; we'll try again after deduction. */
9899 {
9905 pattern);
9906 else
9909 pattern);
9911 }
9913 /* Keep track of the parameter packs and their corresponding
9914 argument packs. */
9917 }
9918 else
9919 {
9920 /* We can't substitute for this parameter pack. We use a flag as
9921 well as the missing_level counter because function parameter
9922 packs don't have a level. */
9924 }
9925 }
9927 /* If the expansion is just T..., return the matching argument pack. */
9932 /* We cannot expand this expansion expression, because we don't have
9933 all of the argument packs we need. */
9935 {
9936 /* We got some full packs, but we can't substitute them in until we
9937 have values for all the packs. So remember these until then. */
9942 }
9944 {
9945 /* There were no real arguments, we're just replacing a parameter
9946 pack with another version of itself. Substitute into the
9947 pattern and return a PACK_EXPANSION_*. The caller will need to
9948 deal with that. */
9952 else
9956 }
9961 {
9962 /* We're in a late-specified return type, so create our own local
9963 specializations map; the current map is either NULL or (in the
9964 case of recursive unification) might have bindings that we don't
9965 want to use or alter. */
9968 }
9970 /* For each argument in each argument pack, substitute into the
9971 pattern. */
9974 {
9976 i,
9978 in_decl);
9981 {
9984 }
9985 }
9987 /* Update ARGS to restore the substitution from parameter packs to
9988 their argument packs. */
9990 {
9996 else
9997 {
10005 /* Update the corresponding argument. */
10009 else
10011 }
10012 }
10015 {
10018 }
10021 }
10023 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10024 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10025 parameter packs; all parms generated from a function parameter pack will
10026 have the same DECL_PARM_INDEX. */
10028 tree
10030 {
10032 tree patparm;
10035 {
10041 }
10042 else
10043 {
10048 }
10051 }
10053 /* Substitute ARGS into the vector or list of template arguments T. */
10055 static tree
10057 {
10069 {
10071 tree new_arg;
10076 {
10077 /* Substitute into an expansion expression. */
10081 /* Add to the expanded length adjustment the number of
10082 expanded arguments. We subtract one from this
10083 measurement, because the argument pack expression
10084 itself is already counted as 1 in
10085 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
10086 the argument pack is empty. */
10088 }
10090 {
10091 /* Substitute into each of the arguments. */
10097 new_arg,
10111 }
10112 }
10113 else
10122 }
10127 /* Make space for the expanded arguments coming from template
10128 argument packs. */
10130 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10131 arguments for a member template.
10132 In that case each TREE_VEC in ORIG_T represents a level of template
10133 arguments, and ORIG_T won't carry any non defaulted argument count.
10134 It will rather be the nested TREE_VECs that will carry one.
10135 In other words, ORIG_T carries a non defaulted argument count only
10136 if it doesn't contain any nested TREE_VEC. */
10138 {
10142 }
10144 {
10148 {
10151 /* Now expand the template argument pack "in place". */
10154 }
10155 else
10156 {
10158 out++;
10159 }
10160 }
10163 }
10165 /* Return the result of substituting ARGS into the template parameters
10166 given by PARMS. If there are m levels of ARGS and m + n levels of
10167 PARMS, then the result will contain n levels of PARMS. For
10168 example, if PARMS is `template <class T> template <class U>
10169 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10170 result will be `template <int*, double, class V>'. */
10172 static tree
10174 {
10178 /* When substituting into a template, we must set
10179 PROCESSING_TEMPLATE_DECL as the template parameters may be
10180 dependent if they are based on one-another, and the dependency
10181 predicates are short-circuit outside of templates. */
10188 {
10189 tree new_vec =
10194 {
10195 tree tuple;
10207 }
10213 }
10218 }
10220 /* Return the result of substituting ARGS into one template parameter
10221 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10222 parameter and which TREE_PURPOSE is the default argument of the
10223 template parameter. */
10225 static tree
10227 {
10248 }
10250 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10251 type T. If T is not an aggregate or enumeration type, it is
10252 handled as if by tsubst. IN_DECL is as for tsubst. If
10253 ENTERING_SCOPE is nonzero, T is the context for a template which
10254 we are presently tsubst'ing. Return the substituted value. */
10256 static tree
10258 tree args,
10259 tsubst_flags_t complain,
10260 tree in_decl,
10262 {
10267 {
10272 /* Else fall through. */
10276 {
10277 tree argvec;
10278 tree context;
10279 tree r;
10283 /* In "sizeof(X<I>)" we need to evaluate "I". */
10289 /* First, determine the context for the type we are looking
10290 up. */
10293 {
10296 /* If context is a nested class inside a class template,
10297 it may still need to be instantiated (c++/33959). */
10299 }
10301 /* Then, figure out what arguments are appropriate for the
10302 type we are trying to find. For example, given:
10304 template <class T> struct S;
10305 template <class T, class U> void f(T, U) { S<U> su; }
10307 and supposing that we are instantiating f<int, double>,
10308 then our ARGS will be {int, double}, but, when looking up
10309 S we only want {double}. */
10314 else
10315 {
10319 }
10325 }
10326 else
10327 /* This is not a template type, so there's nothing to do. */
10332 }
10333 }
10335 /* Substitute into the default argument ARG (a default argument for
10336 FN), which has the indicated TYPE. */
10338 tree
10340 {
10345 /* This can happen in invalid code. */
10349 /* This default argument came from a template. Instantiate the
10350 default argument here, not in tsubst. In the case of
10351 something like:
10353 template <class T>
10354 struct S {
10355 static T t();
10356 void f(T = t());
10357 };
10359 we must be careful to do name lookup in the scope of S<T>,
10360 rather than in the current class. */
10362 /* The "this" pointer is not valid in a default argument. */
10364 {
10369 }
10372 /* The default argument expression may cause implicitly defined
10373 member functions to be synthesized, which will result in garbage
10374 collection. We must treat this situation as if we were within
10375 the body of function so as to avoid collecting live data on the
10376 stack. */
10384 /* Restore the "this" pointer. */
10386 {
10389 }
10396 /* Make sure the default argument is reasonable. */
10402 }
10404 /* Substitute into all the default arguments for FN. */
10406 static void
10408 {
10409 tree arg;
10410 tree tmpl_args;
10414 /* If this function is not yet instantiated, we certainly don't need
10415 its default arguments. */
10418 /* Don't do this again for clones. */
10423 arg;
10429 complain);
10430 }
10432 /* Substitute the ARGS into the T, which is a _DECL. Return the
10433 result of the substitution. Issue error and warning messages under
10434 control of COMPLAIN. */
10436 static tree
10438 {
10439 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10440 location_t saved_loc;
10445 /* Set the filename and linenumber to improve error-reporting. */
10450 {
10452 {
10453 /* We can get here when processing a member function template,
10454 member class template, or template template parameter. */
10456 tree spec;
10457 tree tmpl_args;
10458 tree full_args;
10461 {
10462 /* Template template parameter is treated here. */
10466 /* If we get a real template back, return it. This can happen in
10467 the context of most_specialized_class. */
10479 complain);
10482 }
10484 /* We might already have an instance of this template.
10485 The ARGS are for the surrounding class type, so the
10486 full args contain the tsubst'd args for the context,
10487 plus the innermost args from the template decl. */
10491 /* Because this is a template, the arguments will still be
10492 dependent, even after substitution. If
10493 PROCESSING_TEMPLATE_DECL is not set, the dependency
10494 predicates will short-circuit. */
10502 /* If this is a default template template argument,
10503 tsubst might not have changed anything. */
10510 {
10513 }
10515 /* Make a new template decl. It will be similar to the
10516 original, but will record the current template arguments.
10517 We also create a new function declaration, which is just
10518 like the old one, but points to this new template, rather
10519 than the old one. */
10528 {
10529 tree new_type;
10537 /* For a partial specialization, we need to keep pointing to
10538 the primary template. */
10544 }
10545 else
10546 {
10547 tree new_decl;
10559 }
10565 /* The template parameters for this new template are all the
10566 template parameters for the old template, except the
10567 outermost level of parameters. */
10570 complain);
10576 /* Record this non-type partial instantiation. */
10580 }
10584 {
10585 tree ctx;
10588 tree gen_tmpl;
10589 tree type;
10594 /* Nobody should be tsubst'ing into non-template functions. */
10598 {
10599 tree spec;
10602 /* If T is not dependent, just return it. We have to
10603 increment PROCESSING_TEMPLATE_DECL because
10604 value_dependent_expression_p assumes that nothing is
10605 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10612 /* Calculate the most general template of which R is a
10613 specialization, and the complete set of arguments used to
10614 specialize R. */
10617 (DECL_TEMPLATE_RESULT
10623 /* Check to see if we already have this specialization. */
10628 {
10631 }
10633 /* We can see more levels of arguments than parameters if
10634 there was a specialization of a member template, like
10635 this:
10637 template <class T> struct S { template <class U> void f(); }
10638 template <> template <class U> void S<int>::f(U);
10640 Here, we'll be substituting into the specialization,
10641 because that's where we can find the code we actually
10642 want to generate, but we'll have enough arguments for
10643 the most general template.
10645 We also deal with the peculiar case:
10647 template <class T> struct S {
10648 template <class U> friend void f();
10649 };
10650 template <class U> void f() {}
10651 template S<int>;
10652 template void f<double>();
10654 Here, the ARGS for the instantiation of will be {int,
10655 double}. But, we only need as many ARGS as there are
10656 levels of template parameters in CODE_PATTERN. We are
10657 careful not to get fooled into reducing the ARGS in
10658 situations like:
10660 template <class T> struct S { template <class U> void f(U); }
10661 template <class T> template <> void S<T>::f(int) {}
10663 which we can spot because the pattern will be a
10664 specialization in this case. */
10666 parms_depth =
10671 }
10672 else
10673 {
10674 /* This special case arises when we have something like this:
10676 template <class T> struct S {
10677 friend void f<int>(int, double);
10678 };
10680 Here, the DECL_TI_TEMPLATE for the friend declaration
10681 will be an IDENTIFIER_NODE. We are being called from
10682 tsubst_friend_function, and we want only to create a
10683 new decl (R) with appropriate types so that we can call
10684 determine_specialization. */
10686 }
10689 {
10692 else
10696 }
10697 else
10698 {
10701 }
10706 /* If we hit excessive deduction depth, the type is bogus even if
10707 it isn't error_mark_node, so don't build a decl. */
10711 /* We do NOT check for matching decls pushed separately at this
10712 point, as they may not represent instantiations of this
10713 template, and in any case are considered separate under the
10714 discrete model. */
10718 /* Clear out the mangled name and RTL for the instantiation. */
10721 /* Leave DECL_INITIAL set on deleted instantiations. */
10726 /* OpenMP UDRs have the only argument a reference to the declared
10727 type. We want to diagnose if the declared type is a reference,
10728 which is invalid, but as references to references are usually
10729 quietly merged, diagnose it here. */
10731 {
10732 tree argtype
10737 "reference type %qT in "
10741 argtype);
10742 }
10745 /* Type-conversion operator. Reconstruct the name, in
10746 case it's the name of one of the template's parameters. */
10756 /* If this is an instantiation of a function with internal
10757 linkage, we already know what object file linkage will be
10758 assigned to the instantiation. */
10767 /* We'll re-clone as appropriate in instantiate_template. */
10770 /* If we aren't complaining now, return on error before we register
10771 the specialization so that we'll complain eventually. */
10777 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10778 this in the special friend case mentioned above where
10779 GEN_TMPL is NULL. */
10781 {
10786 tree new_r
10789 /* We instantiated this while substituting into
10790 the type earlier (template/friend54.C). */
10793 /* We're not supposed to instantiate default arguments
10794 until they are called, for a template. But, for a
10795 declaration like:
10797 template <class T> void f ()
10798 { extern void g(int i = T()); }
10800 we should do the substitution when the template is
10801 instantiated. We handle the member function case in
10802 instantiate_class_template since the default arguments
10803 might refer to other members of the class. */
10808 }
10809 else
10812 /* Copy the list of befriending classes. */
10816 {
10820 in_decl);
10821 }
10824 {
10830 /* If this is an instantiation of a member template, clone it.
10831 If it isn't, that'll be handled by
10832 clone_constructors_and_destructors. */
10835 }
10846 /* Possibly limit visibility based on template args. */
10849 {
10853 }
10861 }
10865 {
10873 {
10874 /* If there is a local specialization that isn't a
10875 parameter pack, it means that we're doing a "simple"
10876 substitution from inside tsubst_pack_expansion. Just
10877 return the local specialization (which will be a single
10878 parm). */
10885 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10886 the parameters in this function parameter pack. */
10890 {
10893 /* Zero-length parameter packs are boring. Just substitute
10894 into the chain. */
10898 }
10899 else
10900 {
10901 /* All we did was update the type. Make a note of that. */
10904 }
10905 }
10907 /* Loop through all of the parameters we'll build. When T is
10908 a function parameter pack, LEN is the number of expanded
10909 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10912 {
10919 /* We're on the Ith parameter of the function parameter
10920 pack. */
10921 {
10922 /* Get the Ith type. */
10925 /* Rename the parameter to include the index. */
10928 }
10930 /* We're dealing with a normal parameter. */
10938 {
10941 else
10944 }
10954 /* Keep track of the first new parameter we
10955 generate. That's what will be returned to the
10956 caller. */
10960 /* Build a proper chain of parameters when substituting
10961 into a function parameter pack. */
10964 }
10966 /* If cp_unevaluated_operand is set, we're just looking for a
10967 single dummy parameter, so don't keep going. */
10972 /* FIRST_R contains the start of the chain we've built. */
10974 }
10978 {
10985 {
10986 /* This field is a lambda capture pack. Return a TREE_VEC of
10987 the expanded fields to instantiate_class_template_1 and
10988 store them in the specializations hash table as a
10989 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10993 {
10996 }
10997 else
10998 {
10999 /* All we did was update the type. Make a note of that. */
11002 }
11003 }
11006 {
11009 {
11013 }
11023 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11024 non-bit-fields DECL_INITIAL is a non-static data member
11025 initializer, which gets deferred instantiation. */
11031 {
11032 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11033 NSDMI in perform_member_init. Still set DECL_INITIAL
11034 so that we know there is one. */
11039 }
11040 /* We don't have to set DECL_CONTEXT here; it is set by
11041 finish_member_declaration. */
11049 }
11052 {
11060 }
11061 }
11065 /* We reach here only for member using decls. We also need to check
11066 uses_template_parms because DECL_DEPENDENT_P is not set for a
11067 using-declaration that designates a member of the current
11068 instantiation (c++/53549). */
11071 {
11078 else
11079 {
11082 }
11083 }
11084 else
11085 {
11088 }
11093 {
11096 tree spec;
11098 tree ctx;
11107 {
11108 /* If this is the canonical decl, we don't have to
11109 mess with instantiations, and often we can't (for
11110 typename, template type parms and such). Note that
11111 TYPE_NAME is not correct for the above test if
11112 we've copied the type for a typedef. */
11118 }
11120 /* Check to see if we already have the specialization we
11121 need. */
11124 {
11125 /* T is a static data member or namespace-scope entity.
11126 We have to substitute into namespace-scope variables
11127 (even though such entities are never templates) because
11128 of cases like:
11130 template <class T> void f() { extern T t; }
11132 where the entity referenced is not known until
11133 instantiation time. */
11137 {
11139 complain,
11141 /* If CTX is unchanged, then T is in fact the
11142 specialization we want. That situation occurs when
11143 referencing a static data member within in its own
11144 class. We can use pointer equality, rather than
11145 same_type_p, because DECL_CONTEXT is always
11146 canonical... */
11148 /* ... unless T is a member template; in which
11149 case our caller can be willing to create a
11150 specialization of that template represented
11151 by T. */
11155 }
11158 {
11166 }
11167 }
11168 else
11169 {
11170 /* A local variable. */
11172 /* Subsequent calls to pushdecl will fill this in. */
11175 }
11176 /* If we already have the specialization we need, there is
11177 nothing more to do. */
11179 {
11182 }
11184 /* Create a new node for the specialization we need. */
11187 {
11190 else
11197 }
11199 {
11200 /* Even if the original location is out of scope, the
11201 newly substituted one is not. */
11208 {
11209 /* It may seem that this case cannot occur, since:
11211 typedef void f();
11212 void g() { f x; }
11214 declares a function, not a variable. However:
11216 typedef void f();
11217 template <typename T> void g() { T t; }
11218 template void g<f>();
11220 is an attempt to declare a variable with function
11221 type. */
11223 /* R is not yet sufficiently initialized, so we
11224 just use its name. */
11227 }
11229 /* Wait until cp_finish_decl to set this again, to handle
11230 circular dependency (template/instantiate6.C). */
11235 {
11240 {
11243 }
11245 }
11248 }
11254 /* Clear out the mangled name and RTL for the instantiation. */
11258 /* The initializer must not be expanded until it is required;
11259 see [temp.inst]. */
11265 {
11266 /* Possibly limit visibility based on template args. */
11269 {
11273 }
11275 }
11278 {
11279 /* A static data member declaration is always marked
11280 external when it is declared in-class, even if an
11281 initializer is present. We mimic the non-template
11282 processing here. */
11288 }
11298 /* Preserve a typedef that names a type. */
11300 {
11303 }
11306 }
11311 }
11312 #undef RETURN
11314 out:
11315 /* Restore the file and line information. */
11319 }
11321 /* Substitute into the ARG_TYPES of a function type.
11322 If END is a TREE_CHAIN, leave it and any following types
11323 un-substituted. */
11325 static tree
11327 tree args,
11328 tree end,
11329 tsubst_flags_t complain,
11330 tree in_decl)
11331 {
11332 tree remaining_arg_types;
11336 tree default_arg;
11347 {
11348 /* For a pack expansion, perform substitution on the
11349 entire expression. Later on, we'll handle the arguments
11350 one-by-one. */
11355 /* So that we'll spin through the parameters, one by one. */
11357 else
11358 {
11359 /* We only partially substituted into the parameter
11360 pack. Our type is TYPE_PACK_EXPANSION. */
11363 }
11364 }
11377 {
11379 {
11383 }
11385 }
11386 /* DR 657. */
11390 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11391 top-level qualifiers as required. */
11394 /* We do not substitute into default arguments here. The standard
11395 mandates that they be instantiated only when needed, which is
11396 done in build_over_call. */
11400 {
11401 /* We've instantiated a template before its default arguments
11402 have been parsed. This can happen for a nested template
11403 class, and is not an error unless we require the default
11404 argument in a call of this function. */
11405 remaining_arg_types =
11408 }
11409 else
11410 remaining_arg_types =
11412 }
11415 }
11417 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11418 *not* handle the exception-specification for FNTYPE, because the
11419 initial substitution of explicitly provided template parameters
11420 during argument deduction forbids substitution into the
11421 exception-specification:
11423 [temp.deduct]
11425 All references in the function type of the function template to the
11426 corresponding template parameters are replaced by the specified tem-
11427 plate argument values. If a substitution in a template parameter or
11428 in the function type of the function template results in an invalid
11429 type, type deduction fails. [Note: The equivalent substitution in
11430 exception specifications is done only when the function is instanti-
11431 ated, at which point a program is ill-formed if the substitution
11432 results in an invalid type.] */
11434 static tree
11436 tree args,
11437 tsubst_flags_t complain,
11438 tree in_decl)
11439 {
11440 tree return_type;
11442 tree fntype;
11444 /* The TYPE_CONTEXT is not used for function/method types. */
11447 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
11448 failure. */
11452 {
11453 /* Substitute the argument types. */
11465 {
11466 /* DR 1207: 'this' is in scope in the trailing return type. */
11468 }
11470 /* Substitute the return type. */
11474 {
11477 }
11478 }
11479 else
11480 /* Substitute the return type. */
11485 /* DR 486 clarifies that creation of a function type with an
11486 invalid return type is a deduction failure. */
11489 {
11491 {
11494 else
11496 }
11498 }
11499 /* And DR 657. */
11504 {
11505 /* Substitute the argument types. */
11510 }
11512 /* Construct a new type node and return it. */
11514 {
11519 }
11520 else
11521 {
11523 /* Don't pick up extra function qualifiers from the basetype. */
11526 {
11527 /* [temp.deduct]
11529 Type deduction may fail for any of the following
11530 reasons:
11532 -- Attempting to create "pointer to member of T" when T
11533 is not a class type. */
11536 r);
11538 }
11543 }
11550 }
11552 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11553 ARGS into that specification, and return the substituted
11554 specification. If there is no specification, return NULL_TREE. */
11556 static tree
11558 tree args,
11559 tsubst_flags_t complain,
11560 tree in_decl,
11562 {
11563 tree specs;
11564 tree new_specs;
11569 {
11570 /* A noexcept-specifier. */
11575 {
11576 /* Defer instantiation of noexcept-specifiers to avoid
11577 excessive instantiations (c++/49107). */
11580 {
11581 /* We already partially instantiated this member template,
11582 so combine the new args with the old. */
11587 }
11588 else
11589 {
11592 }
11593 }
11594 else
11595 new_specs = tsubst_copy_and_build
11599 }
11601 {
11604 else
11606 {
11607 tree spec;
11612 {
11613 /* Expand the pack expansion type. */
11616 in_decl);
11622 else
11623 {
11624 /* We're substituting into a member template, so
11625 we got a TYPE_PACK_EXPANSION back. Add that
11626 expansion and move on. */
11630 expanded_specs,
11631 complain);
11634 }
11635 }
11638 {
11641 else
11646 complain);
11647 }
11650 }
11651 }
11653 }
11655 /* Take the tree structure T and replace template parameters used
11656 therein with the argument vector ARGS. IN_DECL is an associated
11657 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11658 Issue error and warning messages under control of COMPLAIN. Note
11659 that we must be relatively non-tolerant of extensions here, in
11660 order to preserve conformance; if we allow substitutions that
11661 should not be allowed, we may allow argument deductions that should
11662 not succeed, and therefore report ambiguous overload situations
11663 where there are none. In theory, we could allow the substitution,
11664 but indicate that it should have failed, and allow our caller to
11665 make sure that the right thing happens, but we don't try to do this
11666 yet.
11668 This function is used for dealing with types, decls and the like;
11669 for expressions, use tsubst_expr or tsubst_copy. */
11671 tree
11673 {
11696 else
11701 /* Reuse typedefs. We need to do this to handle dependent attributes,
11702 such as attribute aligned. */
11705 {
11709 {
11710 /* DECL represents an alias template and we want to
11711 instantiate it. */
11715 }
11719 {
11723 }
11728 else
11729 /* The typedef is from a non-template context. */
11733 {
11735 r = cp_build_qualified_type_real
11739 }
11740 else
11741 {
11742 /* We don't have an instantiation yet, so drop the typedef. */
11747 }
11748 }
11761 {
11787 {
11793 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11794 needed. */
11800 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11801 with TREE_SIDE_EFFECTS that indicates this is not an integral
11802 constant expression. */
11805 {
11808 }
11811 }
11817 {
11830 {
11834 {
11835 /* See through ARGUMENT_PACK_SELECT arguments. */
11837 /* If the selected argument is an expansion E, that most
11838 likely means we were called from
11839 gen_elem_of_pack_expansion_instantiation during the
11840 substituting of pack an argument pack (which Ith
11841 element is a pack expansion, where I is
11842 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11843 In this case, the Ith element resulting from this
11844 substituting is going to be a pack expansion, which
11845 pattern is the pattern of E. Let's return the
11846 pattern of E, and
11847 gen_elem_of_pack_expansion_instantiation will
11848 build the resulting pack expansion from it. */
11850 {
11851 /* Make sure we aren't throwing away arg info. */
11854 }
11855 }
11856 }
11861 {
11863 /* If ARG is an argument pack, we don't actually want to
11864 perform a substitution here, because substitutions
11865 for argument packs are only done
11866 element-by-element. We can get to this point when
11867 substituting the type of a non-type template
11868 parameter pack, when that type actually contains
11869 template parameter packs from an outer template, e.g.,
11871 template<typename... Types> struct A {
11872 template<Types... Values> struct B { };
11873 }; */
11877 {
11883 return cp_build_qualified_type_real
11885 }
11887 {
11888 /* We are processing a type constructed from a
11889 template template parameter. */
11900 /* Consider this code:
11902 template <template <class> class Template>
11903 struct Internal {
11904 template <class Arg> using Bind = Template<Arg>;
11905 };
11907 template <template <class> class Template, class Arg>
11908 using Instantiate = Template<Arg>; //#0
11910 template <template <class> class Template,
11911 class Argument>
11912 using Bind =
11913 Instantiate<Internal<Template>::template Bind,
11914 Argument>; //#1
11916 When #1 is parsed, the
11917 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11918 parameter `Template' in #0 matches the
11919 UNBOUND_CLASS_TEMPLATE representing the argument
11920 `Internal<Template>::template Bind'; We then want
11921 to assemble the type `Bind<Argument>' that can't
11922 be fully created right now, because
11923 `Internal<Template>' not being complete, the Bind
11924 template cannot be looked up in that context. So
11925 we need to "store" `Bind<Argument>' for later
11926 when the context of Bind becomes complete. Let's
11927 store that in a TYPENAME_TYPE. */
11931 argvec),
11932 typename_type,
11933 complain);
11935 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11936 are resolving nested-types in the signature of a
11937 member function templates. Otherwise ARG is a
11938 TEMPLATE_DECL and is the real template to be
11939 instantiated. */
11947 complain);
11948 return cp_build_qualified_type_real
11950 }
11951 else
11952 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11954 }
11957 /* This can happen during the attempted tsubst'ing in
11958 unify. This means that we don't yet have any information
11959 about the template parameter in question. */
11962 /* Early in template argument deduction substitution, we don't
11963 want to reduce the level of 'auto', or it will be confused
11964 with a normal template parm in subsequent deduction. */
11968 /* If we get here, we must have been looking at a parm for a
11969 more deeply nested template. Make a new version of this
11970 template parameter, but with a lower level. */
11972 {
11977 {
11979 r = cp_build_qualified_type_real
11983 }
11984 else
11985 {
11996 /* We have reduced the level of the template
11997 template parameter, but not the levels of its
11998 template parameters, so canonical_type_parameter
11999 will not be able to find the canonical template
12000 template parameter for this level. Thus, we
12001 require structural equality checking to compare
12002 TEMPLATE_TEMPLATE_PARMs. */
12006 else
12010 {
12018 }
12019 }
12028 }
12031 }
12034 {
12042 {
12046 }
12049 {
12053 }
12056 {
12060 }
12066 }
12069 /* We should never be tsubsting a binfo. */
12073 /* A vector of template arguments. */
12079 {
12083 /* [temp.deduct]
12085 Type deduction may fail for any of the following
12086 reasons:
12088 -- Attempting to create a pointer to reference type.
12089 -- Attempting to create a reference to a reference type or
12090 a reference to void.
12092 Core issue 106 says that creating a reference to a reference
12093 during instantiation is no longer a cause for failure. We
12094 only enforce this check in strict C++98 mode. */
12098 {
12101 /* We keep track of the last time we issued this error
12102 message to avoid spewing a ton of messages during a
12103 single bad template instantiation. */
12106 {
12111 else
12114 }
12117 }
12121 {
12123 {
12126 type);
12127 else
12129 type);
12130 }
12132 }
12134 {
12138 }
12140 /* In C++0x, during template argument substitution, when there is an
12141 attempt to create a reference to a reference type, reference
12142 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12144 "If a template-argument for a template-parameter T names a type
12145 that is a reference to a type A, an attempt to create the type
12146 'lvalue reference to cv T' creates the type 'lvalue reference to
12147 A,' while an attempt to create the type type rvalue reference to
12148 cv T' creates the type T"
12149 */
12150 r = cp_build_reference_type
12153 else
12161 {
12163 pedwarn
12165 code == REFERENCE_TYPE
12168 else
12170 }
12173 /* Will this ever be needed for TYPE_..._TO values? */
12177 }
12179 {
12182 {
12183 /* [temp.deduct]
12185 Type deduction may fail for any of the following
12186 reasons:
12188 -- Attempting to create "pointer to member of T" when T
12189 is not a class type. */
12193 }
12195 {
12199 }
12201 {
12205 }
12208 {
12209 /* The type of the implicit object parameter gets its
12210 cv-qualifiers from the FUNCTION_TYPE. */
12211 tree memptr;
12212 tree method_type
12217 complain);
12218 }
12219 else
12222 complain);
12223 }
12226 {
12227 tree fntype;
12228 tree specs;
12233 /* Substitute the exception specification. */
12241 }
12243 {
12248 /* As an optimization, we avoid regenerating the array type if
12249 it will obviously be the same as T. */
12253 /* These checks should match the ones in create_array_type_for_decl.
12255 [temp.deduct]
12257 The deduction may fail for any of the following reasons:
12259 -- Attempting to create an array with an element type that
12260 is void, a function type, or a reference type, or [DR337]
12261 an abstract class type. */
12267 {
12271 }
12279 {
12282 }
12285 }
12288 {
12298 {
12302 }
12304 {
12305 /* Normally, make_typename_type does not require that the CTX
12306 have complete type in order to allow things like:
12308 template <class T> struct S { typename S<T>::X Y; };
12310 But, such constructs have already been resolved by this
12311 point, so here CTX really should have complete type, unless
12312 it's a partial instantiation. */
12315 {
12319 }
12320 }
12327 {
12330 }
12333 {
12335 {
12339 else
12341 }
12343 {
12347 else
12349 }
12350 }
12352 return cp_build_qualified_type_real
12354 }
12357 {
12369 }
12372 {
12373 tree type;
12389 complain);
12390 }
12393 {
12394 tree type;
12412 else
12413 {
12417 /* In a template ~id could be either a complement expression
12418 or an unqualified-id naming a destructor; if instantiating
12419 it produces an expression, it's not an id-expression or
12420 member access. */
12423 }
12427 complain);
12428 }
12431 {
12435 }
12439 {
12441 tree packed_out =
12443 args,
12444 complain,
12445 in_decl);
12448 /* For template nontype argument packs, also substitute into
12449 the type. */
12454 }
12470 /* We should use one of the expression tsubsts for these codes. */
12476 }
12477 }
12479 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12480 type of the expression on the left-hand side of the "." or "->"
12481 operator. */
12483 static tree
12486 {
12487 tree name;
12488 tree qualifying_scope;
12489 tree fns;
12490 tree optype;
12495 /* A baselink indicates a function from a base class. Both the
12496 BASELINK_ACCESS_BINFO and the base class referenced may
12497 indicate bases of the template class, rather than the
12498 instantiated class. In addition, lookups that were not
12499 ambiguous before may be ambiguous now. Therefore, we perform
12500 the lookup again. */
12507 {
12514 }
12522 /* If lookup found a single function, mark it as used at this
12523 point. (If it lookup found multiple functions the one selected
12524 later by overload resolution will be marked as used at that
12525 point.) */
12531 /* Add back the template arguments, if present. */
12536 template_args);
12537 /* Update the conversion operator type. */
12545 qualifying_scope,
12546 object_type);
12548 }
12550 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12551 true if the qualified-id will be a postfix-expression in-and-of
12552 itself; false if more of the postfix-expression follows the
12553 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12554 of "&". */
12556 static tree
12560 {
12561 tree expr;
12562 tree scope;
12563 tree name;
12565 tree template_args;
12570 /* Figure out what name to look up. */
12573 {
12581 }
12582 else
12583 {
12586 }
12588 /* Substitute into the qualifying scope. When there are no ARGS, we
12589 are just trying to simplify a non-dependent expression. In that
12590 case the qualifying scope may be dependent, and, in any case,
12591 substituting will not help. */
12594 {
12597 }
12598 else
12602 {
12607 }
12610 {
12612 {
12613 /* A BIT_NOT_EXPR is used to represent a destructor. */
12615 {
12619 }
12620 else
12623 }
12624 else
12628 {
12630 {
12634 }
12636 }
12637 }
12640 {
12642 scope);
12643 /* Remember that there was a reference to this entity. */
12645 }
12648 {
12654 }
12663 {
12664 expr = (adjust_result_of_qualified_name_lookup
12666 expr = (finish_qualified_id_expr
12670 }
12672 /* Expressions do not generally have reference type. */
12674 /* However, if we're about to form a pointer-to-member, we just
12675 want the referenced member referenced. */
12680 }
12682 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
12683 initializer, DECL is the substituted VAR_DECL. Other arguments are as
12684 for tsubst. */
12686 static tree
12689 {
12696 {
12697 /* If we had an initializer but it
12698 instantiated to nothing,
12699 value-initialize the object. This will
12700 only occur when the initializer was a
12701 pack expansion where the parameter packs
12702 used in that expansion were of length
12703 zero. */
12705 complain);
12708 }
12711 }
12713 /* Like tsubst, but deals with expressions. This function just replaces
12714 template parms; to finish processing the resultant expression, use
12715 tsubst_copy_and_build or tsubst_expr. */
12717 static tree
12719 {
12721 tree r;
12729 {
12734 {
12735 /* We get here for a use of 'this' in an NSDMI. */
12737 && current_function_decl
12741 /* This can happen for a parameter name used later in a function
12742 declaration (such as in a late-specified return type). Just
12743 make a dummy decl, since it's only used for its type. */
12746 /* Give it the template pattern as its context; its true context
12747 hasn't been instantiated yet and this is good enough for
12748 mangling. */
12750 }
12758 {
12759 tree enum_type;
12760 tree v;
12764 /* There is no need to substitute into namespace-scope
12765 enumerators. */
12768 /* If ARGS is NULL, then T is known to be non-dependent. */
12772 /* Unfortunately, we cannot just call lookup_name here.
12773 Consider:
12775 template <int I> int f() {
12776 enum E { a = I };
12777 struct S { void g() { E e = a; } };
12778 };
12780 When we instantiate f<7>::S::g(), say, lookup_name is not
12781 clever enough to find f<7>::a. */
12782 enum_type
12792 /* We didn't find the name. That should never happen; if
12793 name-lookup found it during preliminary parsing, we
12794 should find it again here during instantiation. */
12796 }
12801 {
12802 /* Check for a local specialization set up by
12803 tsubst_pack_expansion. */
12805 {
12809 }
12811 /* When retrieving a capture pack from a generic lambda, remove the
12812 lambda call op's own template argument list from ARGS. Only the
12813 template arguments active for the closure type should be used to
12814 retrieve the pack specialization. */
12820 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12821 tsubst_decl put in the hash table. */
12823 }
12826 {
12827 tree ctx;
12832 {
12835 {
12839 }
12841 }
12842 }
12851 {
12854 {
12855 /* First try name lookup to find the instantiation. */
12858 {
12859 /* Make sure that the one we found is the one we want. */
12864 }
12868 else
12869 {
12870 /* This can happen for a variable used in a
12871 late-specified return type of a local lambda, or for a
12872 local static or constant. Building a new VAR_DECL
12873 should be OK in all those cases. */
12876 {
12877 /* We can't call cp_finish_decl, so handle the
12878 initializer by hand. */
12889 }
12894 {
12897 at_eof);
12899 /* A use of a local constant decays to its value.
12900 FIXME update for core DR 696. */
12902 }
12903 }
12904 /* Remember this for subsequent uses. */
12907 }
12908 }
12909 else
12918 /* An OVERLOAD will always be a non-dependent overload set; an
12919 overload set from function scope will just be represented with an
12920 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12936 {
12937 /* Template template argument like the following example need
12938 special treatment:
12940 template <template <class> class TT> struct C {};
12941 template <class T> struct D {
12942 template <class U> struct E {};
12943 C<E> c; // #1
12944 };
12945 D<int> d; // #2
12947 We are processing the template argument `E' in #1 for
12948 the template instantiation #2. Originally, `E' is a
12949 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12950 have to substitute this with one having context `D<int>'. */
12954 }
12955 else
12956 /* Ordinary template template argument. */
12967 {
12971 }
12975 {
12985 /* We only want to compute the number of arguments. */
12999 {
13006 else
13009 }
13010 else
13012 }
13014 {
13022 }
13023 /* Fall through */
13039 {
13043 }
13046 {
13047 tree object;
13048 tree name;
13053 {
13057 }
13060 {
13070 }
13075 in_decl);
13076 else
13079 }
13117 {
13121 }
13124 {
13129 }
13132 {
13136 }
13139 {
13147 }
13153 {
13160 }
13163 {
13170 }
13173 {
13180 }
13183 {
13184 /* Substituted template arguments */
13193 }
13196 {
13216 }
13241 /* Fall through. */
13244 {
13247 }
13248 else
13252 /* This is handled by tsubst_copy_and_build. */
13256 {
13260 }
13263 /* We shouldn't have built any of these during initial template
13264 generation. Instead, they should be built during instantiation
13265 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13269 {
13277 }
13295 {
13296 /* Instantiate any typedefs in the type. */
13301 }
13304 /* These can sometimes show up in a partial instantiation, but never
13305 involve template parms. */
13310 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13313 }
13314 }
13316 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13318 static tree
13321 {
13325 {
13331 {
13334 {
13340 }
13341 /* FALLTHRU */
13369 {
13372 {
13379 }
13380 else
13382 }
13412 }
13413 }
13419 }
13421 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13423 static tree
13425 tree in_decl)
13426 {
13427 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13447 {
13450 else
13451 {
13455 }
13456 }
13461 #undef RECUR
13462 }
13464 /* Substitute one OMP_FOR iterator. */
13466 static void
13471 {
13472 #define RECUR(NODE) \
13473 tsubst_expr ((NODE), args, complain, in_decl, \
13474 integral_constant_expression_p)
13483 {
13484 /* We need to jump through some hoops to handle declarations in the
13485 for-init-statement, since we might need to handle auto deduction,
13486 but we need to keep control of initialization. */
13490 }
13491 else
13503 {
13505 {
13506 /* Declare the variable, but don't let that initialize it. */
13511 }
13516 {
13521 }
13522 else
13529 }
13532 {
13533 /* Declare and initialize the variable. */
13536 }
13538 {
13539 tree c;
13541 {
13552 }
13554 {
13559 {
13562 }
13563 }
13564 }
13567 {
13571 }
13572 else
13576 {
13587 {
13595 }
13596 else
13602 {
13608 }
13612 {
13620 }
13621 else
13627 }
13633 #undef RECUR
13634 }
13636 /* Like tsubst_copy for expressions, etc. but also does semantic
13637 processing. */
13639 static tree
13642 {
13643 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13644 #define RECUR(NODE) \
13645 tsubst_expr ((NODE), args, complain, in_decl, \
13646 integral_constant_expression_p)
13649 tree r;
13650 location_t loc;
13662 {
13664 {
13665 tree_stmt_iterator i;
13669 }
13684 else
13693 {
13695 tree init;
13701 {
13704 tree decl;
13712 else
13714 }
13716 {
13717 /* Don't build up decls for a variadic capture proxy, we'll
13718 instantiate the elements directly as needed. */
13720 }
13721 else
13722 {
13726 {
13727 /* By marking the declaration as instantiated, we avoid
13728 trying to instantiate it. Since instantiate_decl can't
13729 handle local variables, and since we've already done
13730 all that needs to be done, that's the right thing to
13731 do. */
13736 /* Anonymous aggregates are a special case. */
13739 {
13742 {
13746 }
13748 }
13754 {
13759 }
13760 else
13761 {
13766 {
13767 /* For __PRETTY_FUNCTION__ we have to adjust the
13768 initializer. */
13772 }
13773 else
13777 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13780 }
13781 }
13782 }
13785 }
13800 {
13810 }
13837 {
13841 }
13849 else
13857 else
13878 {
13882 }
13886 {
13888 tree label;
13893 }
13899 /* Computed goto's must be tsubst'd into. On the other hand,
13900 non-computed gotos must not be; the identifier in question
13901 will have no binding. */
13903 else
13909 {
13925 }
13930 {
13935 }
13936 else
13937 {
13942 else
13949 else
13955 else
13957 }
13961 {
13965 {
13967 /* Prevent instantiate_decl from trying to instantiate
13968 this variable. We've already done all that needs to be
13969 done. */
13972 }
13977 }
13983 {
13984 /* Local classes are not independent templates; they are
13985 instantiated along with their containing function. And this
13986 way we don't have to deal with pushing out of one local class
13987 to instantiate a member of another local class. */
13988 tree fn;
13989 /* Closures are handled by the LAMBDA_EXPR. */
13995 }
13999 {
14000 tree condition;
14003 condition =
14005 args,
14014 }
14039 {
14048 {
14053 }
14065 integral_constant_expression_p);
14074 else
14075 {
14083 }
14086 }
14131 {
14136 {
14139 }
14145 }
14146 else
14147 {
14154 {
14157 }
14160 {
14165 {
14168 }
14174 }
14175 else
14176 {
14180 }
14183 }
14187 {
14193 {
14197 {
14202 }
14206 }
14207 else
14208 {
14213 }
14214 }
14218 {
14222 }
14242 /* If the first operand was a statement, we're done with it. */
14246 complain));
14258 integral_constant_expression_p));
14259 }
14262 out:
14265 #undef RECUR
14266 #undef RETURN
14267 }
14269 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14270 function. For description of the body see comment above
14271 cp_parser_omp_declare_reduction_exprs. */
14273 static void
14275 {
14281 tree_stmt_iterator tsi;
14292 {
14311 }
14313 {
14333 }
14334 }
14336 /* T is a postfix-expression that is not being used in a function
14337 call. Return the substituted version of T. */
14339 static tree
14341 tsubst_flags_t complain,
14342 tree in_decl)
14343 {
14347 else
14353 }
14355 /* Sentinel to disable certain warnings during template substitution. */
14363 };
14365 /* Like tsubst but deals with expressions and performs semantic
14366 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14368 tree
14370 tree args,
14371 tsubst_flags_t complain,
14372 tree in_decl,
14375 {
14376 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14377 #define RECUR(NODE) \
14378 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14380 integral_constant_expression_p)
14383 location_t loc;
14392 /* N3276 decltype magic only applies to calls at the top level or on the
14393 right side of a comma. */
14398 {
14401 /* Fall through. */
14403 {
14404 tree decl;
14405 cp_id_kind idk;
14410 {
14413 }
14415 /* Look up the name. */
14418 /* By convention, expressions use ERROR_MARK_NODE to indicate
14419 failure, not NULL_TREE. */
14425 integral_constant_expression_p,
14433 input_location);
14437 {
14441 }
14443 }
14446 {
14447 tree object;
14455 {
14458 }
14459 else
14466 else
14468 }
14471 {
14475 {
14476 /* A type conversion to reference type will be enclosed in
14477 such an indirect ref, but the substitution of the cast
14478 will have also added such an indirect ref. */
14481 }
14482 else
14486 }
14489 {
14493 }
14496 {
14503 flags));
14504 }
14507 {
14511 }
14518 {
14519 tree type;
14525 {
14530 }
14536 {
14554 }
14557 }
14591 else
14593 in_decl);
14628 {
14633 tree r = build_x_binary_op
14635 op0,
14637 ? ERROR_MARK
14639 op1,
14641 ? ERROR_MARK
14649 }
14652 {
14656 }
14669 {
14678 }
14682 /* Fall through */
14685 {
14686 tree r;
14692 {
14693 /* When there are no ARGS, we are trying to evaluate a
14694 non-dependent expression from the parser. Trying to do
14695 the substitutions may not work. */
14698 }
14699 else
14700 {
14705 else
14708 /*integral_constant_expression_p=*/
14712 }
14716 else
14720 {
14722 {
14724 {
14728 }
14729 else
14733 }
14735 }
14737 }
14740 {
14750 }
14764 {
14768 tree r = build_x_modify_expr
14771 /* TREE_NO_WARNING must be set if either the expression was
14772 parenthesized or it uses an operator such as >>= rather
14773 than plain assignment. In the former case, it was already
14774 set and must be copied. In the latter case,
14775 build_x_modify_expr sets it and it must not be reset
14776 here. */
14781 }
14786 /* Remember that there was a reference to this entity. */
14792 {
14797 tree ret;
14801 else
14802 {
14806 }
14808 /* If there was an initializer in the original tree, but it
14809 instantiated to an empty list, then we should pass a
14810 non-NULL empty vector to tell build_new that it was an
14811 empty initializer() rather than no initializer. This can
14812 only happen when the initializer is a pack expansion whose
14813 parameter packs are of length zero. */
14816 else
14817 {
14821 else
14822 {
14825 }
14826 }
14832 complain);
14840 }
14843 {
14849 complain));
14850 }
14853 {
14857 integral_constant_expression_p);
14859 op0,
14862 }
14865 {
14866 tree function;
14871 tree ret;
14874 /* When we parsed the expression, we determined whether or
14875 not Koenig lookup should be performed. */
14878 {
14883 }
14885 {
14886 /* Do nothing; calling tsubst_copy_and_build on an identifier
14887 would incorrectly perform unqualified lookup again.
14889 Note that we can also have an IDENTIFIER_NODE if the earlier
14890 unqualified lookup found a member function; in that case
14891 koenig_p will be false and we do want to do the lookup
14892 again to find the instantiated member function.
14894 FIXME but doing that causes c++/15272, so we need to stop
14895 using IDENTIFIER_NODE in that situation. */
14897 }
14898 else
14899 {
14901 {
14907 }
14908 else
14913 /* Avoid error about taking the address of a constructor. */
14917 in_decl,
14919 integral_constant_expression_p);
14923 }
14928 {
14933 else
14934 {
14935 /* Expand the pack expansion and push each entry onto
14936 CALL_ARGS. */
14939 {
14944 {
14949 }
14950 }
14951 else
14952 {
14953 /* A partial substitution. Add one entry. */
14955 }
14956 }
14957 }
14959 /* We do not perform argument-dependent lookup if normal
14960 lookup finds a non-function, in accordance with the
14961 expected resolution of DR 218. */
14964 /* If lookup found a member function, the Koenig lookup is
14965 not appropriate, even if an unqualified-name was used
14966 to denote the function. */
14969 /* Only do this when substitution turns a dependent call
14970 into a non-dependent call. */
14977 {
14979 {
14980 /* For backwards compatibility and good diagnostics, try
14981 the unqualified lookup again if we aren't in SFINAE
14982 context. */
14983 tree unq = (tsubst_copy_and_build
14985 integral_constant_expression_p));
14990 {
14999 "%qD was not declared in this scope, "
15000 "and no declarations were found by "
15001 "argument-dependent lookup at the point "
15003 {
15007 {
15009 input_location);
15011 "declarations in dependent base %qT are "
15017 else
15021 }
15022 else
15025 }
15027 }
15028 }
15030 {
15035 }
15036 }
15038 /* Remember that there was a reference to this entity. */
15042 /* Put back tf_decltype for the actual call. */
15047 complain);
15049 {
15064 complain);
15065 else
15066 ret = (build_new_method_call
15071 complain));
15072 }
15073 else
15076 koenig_p,
15077 complain);
15082 }
15085 {
15090 {
15092 {
15097 }
15098 else
15099 {
15104 }
15105 }
15106 else
15107 {
15110 }
15114 }
15117 {
15122 input_location));
15123 }
15126 {
15134 {
15135 /* We have pack expansions, so expand those and
15136 create a new list out of it. */
15139 tree chain;
15142 /* Expand the argument expressions. */
15150 /* Build the rest of the list. */
15155 /* Determine the number of arguments. */
15157 {
15160 }
15163 else
15164 {
15165 /* Since we only performed a partial substitution into
15166 the argument pack, we only RETURN (a single list
15167 node. */
15174 }
15176 /* Convert the argument vectors into a TREE_LIST */
15179 {
15180 /* Grab the Ith values. */
15181 i--;
15184 value
15188 /* Build the list (backwards). */
15190 }
15193 }
15209 }
15212 {
15213 tree object;
15214 tree object_type;
15215 tree member;
15216 tree r;
15220 /* Remember that there was a reference to this entity. */
15230 else
15238 {
15240 {
15245 {
15248 }
15250 {
15255 }
15256 }
15257 }
15260 {
15261 /* Lookup the template functions now that we know what the
15262 scope is. */
15270 {
15273 args);
15274 member = (adjust_result_of_qualified_name_lookup
15276 object_type));
15277 }
15278 else
15279 {
15281 input_location);
15283 }
15284 }
15288 {
15290 {
15294 else
15297 }
15299 }
15301 {
15306 }
15310 complain);
15314 }
15321 {
15329 tree r;
15334 /* digest_init will do the wrong thing if we let it. */
15338 /* We do not want to process the index of aggregate
15339 initializers as they are identifier nodes which will be
15340 looked up by digest_init. */
15346 {
15348 /* An identifier index is looked up in the type
15349 being initialized, not the current scope. */
15354 {
15355 /* Substitute into the pack expansion. */
15357 in_decl);
15361 ;
15363 /* Just move the argument into place. */
15365 else
15366 {
15367 /* Update the length of the final CONSTRUCTOR
15368 arguments vector, and note that we will need to
15369 copy.*/
15372 }
15373 }
15374 else
15376 }
15379 {
15384 {
15386 {
15391 }
15392 else
15394 }
15395 }
15405 }
15408 {
15411 {
15414 }
15415 else
15416 {
15419 }
15420 }
15426 {
15427 /* We don't build decls for an instantiation of a
15428 variadic capture proxy, we instantiate the elements
15429 when needed. */
15432 }
15433 /* Fall through */
15436 {
15439 && !processing_template_decl
15440 && !cp_unevaluated_operand
15443 {
15445 /* Replace an evaluated use of the thread_local variable with
15446 a call to its wrapper. */
15448 }
15451 /* If the original type was a reference, we'll be wrapped in
15452 the appropriate INDIRECT_REF. */
15455 }
15458 {
15462 }
15469 {
15478 }
15481 {
15487 integral_constant_expression_p);
15491 /* If the resulting list of expression statement is empty,
15492 fold it further into void_node. */
15497 }
15500 {
15514 /* For a function scope, we want to use tsubst so that we don't
15515 complain about referring to an auto function before its return
15516 type has been deduced. Otherwise, we want to use tsubst_copy so
15517 that we look up the existing field/parameter/variable rather
15518 than build a new one. */
15523 {
15524 /* Look up the parameter we want directly, as tsubst_copy
15525 doesn't do what we need. */
15531 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15534 }
15535 else
15544 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15546 /* Now that we know visibility, instantiate the type so we have a
15547 declaration of the op() for later calls to lambda_function. */
15553 }
15556 /* We can get here for a constant initializer of non-dependent type.
15557 FIXME stop folding in cp_parser_initializer_clause. */
15558 {
15560 complain);
15562 }
15566 integral_constant_expression_p));
15572 {
15577 complain));
15578 }
15581 /* Handle Objective-C++ constructs, if appropriate. */
15582 {
15583 tree subst
15588 }
15590 }
15592 #undef RECUR
15593 #undef RETURN
15594 out:
15597 }
15599 /* Verify that the instantiated ARGS are valid. For type arguments,
15600 make sure that the type's linkage is ok. For non-type arguments,
15601 make sure they are constants if they are integral or enumerations.
15602 Emit an error under control of COMPLAIN, and return TRUE on error. */
15604 static bool
15606 {
15610 {
15620 }
15622 {
15623 /* [basic.link]: A name with no linkage (notably, the name
15624 of a class or enumeration declared in a local scope)
15625 shall not be used to declare an entity with linkage.
15626 This implies that names with no linkage cannot be used as
15627 template arguments
15629 DR 757 relaxes this restriction for C++0x. */
15634 {
15635 /* DR 488 makes use of a type with no linkage cause
15636 type deduction to fail. */
15638 {
15641 else
15644 }
15646 }
15647 /* In order to avoid all sorts of complications, we do not
15648 allow variably-modified types as template arguments. */
15650 {
15654 }
15655 }
15656 /* Class template and alias template arguments should be OK. */
15658 ;
15659 /* A non-type argument of integral or enumerated type must be a
15660 constant. */
15664 {
15668 }
15670 }
15672 static bool
15674 {
15679 {
15682 }
15686 }
15688 /* We're out of SFINAE context now, so generate diagnostics for the access
15689 errors we saw earlier when instantiating D from TMPL and ARGS. */
15691 static void
15693 {
15705 }
15707 /* Instantiate the indicated variable, function, or alias template TMPL with
15708 the template arguments in TARG_PTR. */
15710 static tree
15712 {
15714 tree fndecl;
15715 tree gen_tmpl;
15716 tree spec;
15724 /* If this function is a clone, handle it specially. */
15726 {
15727 tree spec;
15728 tree clone;
15730 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15731 DECL_CLONED_FUNCTION. */
15737 /* Look for the clone. */
15741 /* We should always have found the clone by now. */
15744 }
15749 /* Check to see if we already have this specialization. */
15752 /* The TMPL is a partial instantiation. To get a full set of
15753 arguments we must add the arguments used to perform the
15754 partial instantiation. */
15756 targ_ptr);
15758 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15759 but it doesn't seem to be on the hot path. */
15768 {
15770 {
15774 }
15776 }
15779 complain))
15782 /* We are building a FUNCTION_DECL, during which the access of its
15783 parameters and return types have to be checked. However this
15784 FUNCTION_DECL which is the desired context for access checking
15785 is not built yet. We solve this chicken-and-egg problem by
15786 deferring all checks until we have the FUNCTION_DECL. */
15789 /* Instantiation of the function happens in the context of the function
15790 template, not the context of the overload resolution we're doing. */
15792 /* If there are dependent arguments, e.g. because we're doing partial
15793 ordering, make sure processing_template_decl stays set. */
15797 {
15801 }
15802 /* Substitute template parameters to obtain the specialization. */
15810 {
15813 }
15815 /* The DECL_TI_TEMPLATE should always be the immediate parent
15816 template, not the most general template. */
15819 /* Now we know the specialization, compute access previously
15820 deferred. */
15827 /* If we've just instantiated the main entry point for a function,
15828 instantiate all the alternate entry points as well. We do this
15829 by cloning the instantiation of the main entry point, not by
15830 instantiating the template clones. */
15835 {
15837 {
15838 /* Remember to reinstantiate when we're out of SFINAE so the user
15839 can see the errors. */
15841 }
15843 }
15845 }
15847 /* Wrapper for instantiate_template_1. */
15849 tree
15851 {
15852 tree ret;
15857 }
15859 /* Instantiate the alias template TMPL with ARGS. Also push a template
15860 instantiation level, which instantiate_template doesn't do because
15861 functions and variables have sufficient context established by the
15862 callers. */
15864 static tree
15866 {
15873 {
15876 }
15878 args =
15886 /* We can't free this if a pending_template entry or last_error_tinst_level
15887 is pointing at it. */
15893 }
15895 /* PARM is a template parameter pack for FN. Returns true iff
15896 PARM is used in a deducible way in the argument list of FN. */
15898 static bool
15900 {
15903 {
15905 tree packs;
15911 {
15912 /* The template parameter pack is used in a function parameter
15913 pack. If this is the end of the parameter list, the
15914 template parameter pack is deducible. */
15917 else
15918 /* Otherwise, not. Well, it could be deduced from
15919 a non-pack parameter, but doing so would end up with
15920 a deduction mismatch, so don't bother. */
15922 }
15923 }
15924 /* The template parameter pack isn't used in any function parameter
15925 packs, but it might be used deeper, e.g. tuple<Args...>. */
15927 }
15929 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15930 NARGS elements of the arguments that are being used when calling
15931 it. TARGS is a vector into which the deduced template arguments
15932 are placed.
15934 Returns either a FUNCTION_DECL for the matching specialization of FN or
15935 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15936 true, diagnostics will be printed to explain why it failed.
15938 If FN is a conversion operator, or we are trying to produce a specific
15939 specialization, RETURN_TYPE is the return type desired.
15941 The EXPLICIT_TARGS are explicit template arguments provided via a
15942 template-id.
15944 The parameter STRICT is one of:
15946 DEDUCE_CALL:
15947 We are deducing arguments for a function call, as in
15948 [temp.deduct.call].
15950 DEDUCE_CONV:
15951 We are deducing arguments for a conversion function, as in
15952 [temp.deduct.conv].
15954 DEDUCE_EXACT:
15955 We are deducing arguments when doing an explicit instantiation
15956 as in [temp.explicit], when determining an explicit specialization
15957 as in [temp.expl.spec], or when taking the address of a function
15958 template, as in [temp.deduct.funcaddr]. */
15960 tree
15962 tree explicit_targs,
15963 tree targs,
15966 tree return_type,
15967 unification_kind_t strict,
15971 {
15972 tree parms;
15973 tree fntype;
15981 tree tinst;
15987 /* In C++0x, it's possible to have a function template whose type depends
15988 on itself recursively. This is most obvious with decltype, but can also
15989 occur with enumeration scope (c++/48969). So we need to catch infinite
15990 recursion and reject the substitution at deduction time; this function
15991 will return error_mark_node for any repeated substitution.
15993 This also catches excessive recursion such as when f<N> depends on
15994 f<N-1> across all integers, and returns error_mark_node for all the
15995 substitutions back up to the initial one.
15997 This is, of course, not reentrant. */
16007 {
16008 /* [temp.deduct]
16010 The specified template arguments must match the template
16011 parameters in kind (i.e., type, nontype, template), and there
16012 must not be more arguments than there are parameters;
16013 otherwise type deduction fails.
16015 Nontype arguments must match the types of the corresponding
16016 nontype template parameters, or must be convertible to the
16017 types of the corresponding nontype parameters as specified in
16018 _temp.arg.nontype_, otherwise type deduction fails.
16020 All references in the function type of the function template
16021 to the corresponding template parameters are replaced by the
16022 specified template argument values. If a substitution in a
16023 template parameter or in the function type of the function
16024 template results in an invalid type, type deduction fails. */
16029 /* Adjust any explicit template arguments before entering the
16030 substitution context. */
16031 explicit_targs
16033 complain,
16039 /* Substitute the explicit args into the function type. This is
16040 necessary so that, for instance, explicitly declared function
16041 arguments can match null pointed constants. If we were given
16042 an incomplete set of explicit args, we must not do semantic
16043 processing during substitution as we could create partial
16044 instantiations. */
16046 {
16051 /* Dig out the actual parm. */
16054 {
16057 }
16059 {
16062 }
16065 /* No explicit argument for this template parameter. */
16069 {
16070 /* Mark the argument pack as "incomplete". We could
16071 still deduce more arguments during unification.
16072 We remove this mark in type_unification_real. */
16074 {
16078 }
16080 /* We have some incomplete argument packs. */
16082 }
16083 }
16087 {
16090 }
16093 /* Ignore any access checks; we'll see them again in
16094 instantiate_template and they might have the wrong
16095 access path at this point. */
16107 /* Place the explicitly specified arguments in TARGS. */
16110 }
16112 /* Never do unification on the 'this' parameter. */
16116 {
16125 }
16127 /* We allow incomplete unification without an error message here
16128 because the standard doesn't seem to explicitly prohibit it. Our
16129 callers must be ready to deal with unification failures in any
16130 event. */
16133 /* If we aren't explaining yet, push tinst context so we can see where
16134 any errors (e.g. from class instantiations triggered by instantiation
16135 of default template arguments) come from. If we are explaining, this
16136 context is redundant. */
16138 {
16141 }
16143 /* type_unification_real will pass back any access checks from default
16144 template argument substitution. */
16156 /* Now that we have bindings for all of the template arguments,
16157 ensure that the arguments deduced for the template template
16158 parameters have compatible template parameter lists. We cannot
16159 check this property before we have deduced all template
16160 arguments, because the template parameter types of a template
16161 template parameter might depend on prior template parameters
16162 deduced after the template template parameter. The following
16163 ill-formed example illustrates this issue:
16165 template<typename T, template<T> class C> void f(C<5>, T);
16167 template<int N> struct X {};
16169 void g() {
16170 f(X<5>(), 5l); // error: template argument deduction fails
16171 }
16173 The template parameter list of 'C' depends on the template type
16174 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
16175 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
16176 time that we deduce 'C'. */
16179 {
16182 }
16184 /* All is well so far. Now, check:
16186 [temp.deduct]
16188 When all template arguments have been deduced, all uses of
16189 template parameters in nondeduced contexts are replaced with
16190 the corresponding deduced argument values. If the
16191 substitution results in an invalid type, as described above,
16192 type deduction fails. */
16195 {
16198 }
16200 /* Also collect access checks from the instantiation. */
16213 /* Now perform any access checks encountered during substitution. */
16220 /* If we're looking for an exact match, check that what we got
16221 is indeed an exact match. It might not be if some template
16222 parameters are used in non-deduced contexts. But don't check
16223 for an exact match if we have dependent template arguments;
16224 in that case we're doing partial ordering, and we already know
16225 that we have two candidates that will provide the actual type. */
16227 {
16231 tree sarg
16237 {
16241 }
16242 }
16246 fail:
16249 {
16251 /* Reset once we're all the way out. */
16253 }
16255 /* We can't free this if a pending_template entry or last_error_tinst_level
16256 is pointing at it. */
16262 }
16264 /* Adjust types before performing type deduction, as described in
16265 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16266 sections are symmetric. PARM is the type of a function parameter
16267 or the return type of the conversion function. ARG is the type of
16268 the argument passed to the call, or the type of the value
16269 initialized with the result of the conversion function.
16270 ARG_EXPR is the original argument expression, which may be null. */
16272 static int
16276 tree arg_expr)
16277 {
16281 {
16286 {
16287 /* Swap PARM and ARG throughout the remainder of this
16288 function; the handling is precisely symmetric since PARM
16289 will initialize ARG rather than vice versa. */
16294 }
16297 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16298 too, but here handle it by stripping the reference from PARM
16299 rather than by adding it to ARG. */
16307 /* Nothing else to do in this case. */
16312 }
16315 {
16316 /* [temp.deduct.call]
16318 If P is not a reference type:
16320 --If A is an array type, the pointer type produced by the
16321 array-to-pointer standard conversion (_conv.array_) is
16322 used in place of A for type deduction; otherwise,
16324 --If A is a function type, the pointer type produced by
16325 the function-to-pointer standard conversion
16326 (_conv.func_) is used in place of A for type deduction;
16327 otherwise,
16329 --If A is a cv-qualified type, the top level
16330 cv-qualifiers of A's type are ignored for type
16331 deduction. */
16336 else
16338 }
16340 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16341 of the form T&&, where T is a template parameter, and the argument
16342 is an lvalue, T is deduced as A& */
16348 /* try_one_overload doesn't provide an arg_expr, but
16349 functions are always lvalues. */
16353 /* [temp.deduct.call]
16355 If P is a cv-qualified type, the top level cv-qualifiers
16356 of P's type are ignored for type deduction. If P is a
16357 reference type, the type referred to by P is used for
16358 type deduction. */
16361 {
16364 }
16366 /* DR 322. For conversion deduction, remove a reference type on parm
16367 too (which has been swapped into ARG). */
16372 }
16374 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16375 template which does contain any deducible template parameters; check if
16376 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16377 unify_one_argument. */
16379 static int
16382 {
16383 tree type;
16387 else
16394 {
16398 }
16400 {
16405 }
16409 else
16411 }
16415 /* Returns true iff the expression EXPR is one from which a template
16416 argument can be deduced. In other words, if it's an undecorated
16417 use of a template non-type parameter. */
16419 static bool
16421 {
16423 }
16425 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16426 deducible way; that is, if it has a max value of <PARM> - 1. */
16428 static bool
16430 {
16439 }
16441 /* Returns true iff the template arguments ARGS use a template parameter
16442 in a deducible way. */
16444 static bool
16446 {
16448 {
16453 else
16454 {
16461 else
16463 }
16466 }
16468 }
16470 /* Returns true iff TYPE contains any deducible references to template
16471 parameters, as per 14.8.2.5. */
16473 static bool
16475 {
16479 /* T
16480 cv-list T
16481 TT<T>
16482 TT<i>
16483 TT<> */
16488 /* T*
16489 T&
16490 T&& */
16494 /* T[integer-constant ]
16495 type [i] */
16500 /* T type ::*
16501 type T::*
16502 T T::*
16503 T (type ::*)()
16504 type (T::*)()
16505 type (type ::*)(T)
16506 type (T::*)(T)
16507 T (type ::*)(T)
16508 T (T::*)()
16509 T (T::*)(T) */
16512 || (uses_deducible_template_parms
16515 /* template-name <T> (where template-name refers to a class template)
16516 template-name <i> (where template-name refers to a class template) */
16523 /* type (T)
16524 T()
16525 T(T) */
16528 {
16537 }
16540 }
16542 /* Subroutine of type_unification_real and unify_pack_expansion to
16543 handle unification of a single P/A pair. Parameters are as
16544 for those functions. */
16546 static int
16550 {
16557 /* We can't deduce anything from this, but we might get all the
16558 template args from other function args. */
16561 /* Implicit conversions (Clause 4) will be performed on a function
16562 argument to convert it to the type of the corresponding function
16563 parameter if the parameter type contains no template-parameters that
16564 participate in template argument deduction. */
16566 /* For function parameters that contain no template-parameters at all,
16567 we have historically checked for convertibility in order to shortcut
16568 consideration of this candidate. */
16570 explain_p);
16573 /* For function parameters with only non-deducible template parameters,
16574 just return. */
16578 {
16580 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16581 | UNIFY_ALLOW_MORE_CV_QUAL
16595 }
16597 /* We only do these transformations if this is the top-level
16598 parameter_type_list in a call or declaration matching; in other
16599 situations (nested function declarators, template argument lists) we
16600 won't be comparing a type to an expression, and we don't do any type
16601 adjustments. */
16603 {
16605 {
16608 {
16609 /* [temp.deduct.type] A template-argument can be
16610 deduced from a pointer to function or pointer
16611 to member function argument if the set of
16612 overloaded functions does not contain function
16613 templates and at most one of a set of
16614 overloaded functions provides a unique
16615 match. */
16622 }
16628 }
16630 arg_strict |=
16632 }
16633 else
16638 /* For deduction from an init-list we need the actual list. */
16642 }
16644 /* Most parms like fn_type_unification.
16646 If SUBR is 1, we're being called recursively (to unify the
16647 arguments of a function or method parameter of a function
16648 template).
16650 CHECKS is a pointer to a vector of access checks encountered while
16651 substituting default template arguments. */
16653 static int
16655 tree targs,
16656 tree xparms,
16660 unification_kind_t strict,
16664 {
16669 tree parms;
16678 /* Reset the number of non-defaulted template arguments contained
16679 in TARGS. */
16682 again:
16690 {
16695 /* For a function parameter pack that occurs at the end of the
16696 parameter-declaration-list, the type A of each remaining
16697 argument of the call is compared with the type P of the
16698 declarator-id of the function parameter pack. */
16704 /* For a function parameter pack that does not occur at the
16705 end of the parameter-declaration-list, the type of the
16706 parameter pack is a non-deduced context. */
16715 }
16720 {
16721 /* Unify the remaining arguments with the pack expansion type. */
16722 tree argvec;
16725 /* Allocate a TREE_VEC and copy in all of the arguments */
16730 /* Copy the parameter into parmvec. */
16736 /* Advance to the end of the list of parameters. */
16738 }
16740 /* Fail if we've reached the end of the parm list, and more args
16741 are present, and the parm list isn't variadic. */
16744 /* Fail if parms are left and they don't have default values and
16745 they aren't all deduced as empty packs (c++/57397). This is
16746 consistent with sufficient_parms_p. */
16749 {
16753 do
16754 {
16757 count++;
16759 }
16763 type_pack_p);
16764 }
16767 {
16768 tsubst_flags_t complain = (explain_p
16769 ? tf_warning_or_error
16773 {
16777 /* Clear the "incomplete" flags on all argument packs now so that
16778 substituting them into later default arguments works. */
16780 {
16783 }
16789 /* If this is an undeduced nontype parameter that depends on
16790 a type parameter, try another pass; its type may have been
16791 deduced from a later argument than the one from which
16792 this parameter can be deduced. */
16798 /* Core issue #226 (C++0x) [temp.deduct]:
16800 If a template argument has not been deduced, its
16801 default template argument, if any, is used.
16803 When we are in C++98 mode, TREE_PURPOSE will either
16804 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16805 to explicitly check cxx_dialect here. */
16807 {
16822 else
16823 {
16825 /* The position of the first default template argument,
16826 is also the number of non-defaulted arguments in TARGS.
16827 Record that. */
16831 }
16832 }
16834 /* If the type parameter is a parameter pack, then it will
16835 be deduced to an empty parameter pack. */
16837 {
16838 tree arg;
16841 {
16845 }
16846 else
16853 }
16856 }
16857 }
16858 #ifdef ENABLE_CHECKING
16861 #endif
16864 }
16866 /* Subroutine of type_unification_real. Args are like the variables
16867 at the call site. ARG is an overloaded function (or template-id);
16868 we try deducing template args from each of the overloads, and if
16869 only one succeeds, we go with that. Modifies TARGS and returns
16870 true on success. */
16872 static bool
16874 tree targs,
16875 tree parm,
16876 tree arg,
16877 unification_kind_t strict,
16880 {
16887 {
16890 }
16891 else
16895 /* Handle `&x' where `x' is some static or non-static member
16896 function name. */
16902 /* Strip baselink information. */
16907 {
16908 /* If we got some explicit template args, we need to plug them into
16909 the affected templates before we try to unify, in case the
16910 explicit args will completely resolve the templates in question. */
16917 {
16930 {
16935 {
16938 }
16939 }
16942 }
16943 /* If no templates (or more than one) are fully resolved by the
16944 explicit arguments, this template-id is a non-deduced context; it
16945 could still be OK if we deduce all template arguments for the
16946 enclosing call through other arguments. */
16949 }
16952 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16953 -- but the deduction does not succeed because the expression is
16954 not just the function on its own. */
16956 else
16962 {
16965 }
16967 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16968 to function or pointer to member function argument if the set of
16969 overloaded functions does not contain function templates and at most
16970 one of a set of overloaded functions provides a unique match.
16972 So if we found multiple possibilities, we return success but don't
16973 deduce anything. */
16976 {
16980 {
16985 /* Don't forget explicit template arguments in a pack. */
16989 }
16990 }
16995 }
16997 /* Core DR 115: In contexts where deduction is done and fails, or in
16998 contexts where deduction is not done, if a template argument list is
16999 specified and it, along with any default template arguments, identifies
17000 a single function template specialization, then the template-id is an
17001 lvalue for the function template specialization. */
17003 tree
17005 {
17018 {
17021 }
17023 {
17026 }
17028 {
17031 }
17034 {
17038 /* If we got some explicit template args, we need to plug them into
17039 the affected templates before we try to unify, in case the
17040 explicit args will completely resolve the templates in question. */
17048 {
17061 {
17064 {
17067 }
17069 {
17072 }
17073 }
17074 }
17076 {
17084 {
17085 tree base
17088 }
17092 }
17094 /* There were no good options and at least one bad one, so let the
17095 user know what the problem is. */
17097 }
17099 }
17101 /* Subroutine of resolve_overloaded_unification; does deduction for a single
17102 overload. Fills TARGS with any deduced arguments, or error_mark_node if
17103 different overloads deduce different arguments for a given parm.
17104 ADDR_P is true if the expression for which deduction is being
17105 performed was of the form "& fn" rather than simply "fn".
17107 Returns 1 on success. */
17109 static int
17111 tree orig_targs,
17112 tree targs,
17113 tree parm,
17114 tree arg,
17115 unification_kind_t strict,
17119 {
17121 tree tempargs;
17127 /* [temp.deduct.type] A template-argument can be deduced from a pointer
17128 to function or pointer to member function argument if the set of
17129 overloaded functions does not contain function templates and at most
17130 one of a set of overloaded functions provides a unique match.
17132 So if this is a template, just return success. */
17144 /* We don't copy orig_targs for this because if we have already deduced
17145 some template args from previous args, unify would complain when we
17146 try to deduce a template parameter for the same argument, even though
17147 there isn't really a conflict. */
17154 /* First make sure we didn't deduce anything that conflicts with
17155 explicitly specified args. */
17157 {
17164 /* Since we're unifying against ourselves, we will fill in
17165 template args used in the function parm list with our own
17166 template parms. Discard them. */
17170 }
17173 {
17178 }
17181 }
17183 /* PARM is a template class (perhaps with unbound template
17184 parameters). ARG is a fully instantiated type. If ARG can be
17185 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
17186 TARGS are as for unify. */
17188 static tree
17191 {
17192 tree copy_of_targs;
17199 /* We need to make a new template argument vector for the call to
17200 unify. If we used TARGS, we'd clutter it up with the result of
17201 the attempted unification, even if this class didn't work out.
17202 We also don't want to commit ourselves to all the unifications
17203 we've already done, since unification is supposed to be done on
17204 an argument-by-argument basis. In other words, consider the
17205 following pathological case:
17207 template <int I, int J, int K>
17208 struct S {};
17210 template <int I, int J>
17211 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
17213 template <int I, int J, int K>
17214 void f(S<I, J, K>, S<I, I, I>);
17216 void g() {
17217 S<0, 0, 0> s0;
17218 S<0, 1, 2> s2;
17220 f(s0, s2);
17221 }
17223 Now, by the time we consider the unification involving `s2', we
17224 already know that we must have `f<0, 0, 0>'. But, even though
17225 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17226 because there are two ways to unify base classes of S<0, 1, 2>
17227 with S<I, I, I>. If we kept the already deduced knowledge, we
17228 would reject the possibility I=1. */
17231 /* If unification failed, we're done. */
17237 }
17239 /* Given a template type PARM and a class type ARG, find the unique
17240 base type in ARG that is an instance of PARM. We do not examine
17241 ARG itself; only its base-classes. If there is not exactly one
17242 appropriate base class, return NULL_TREE. PARM may be the type of
17243 a partial specialization, as well as a plain template type. Used
17244 by unify. */
17246 static enum template_base_result
17249 {
17251 tree binfo;
17257 {
17258 /* The type could not be completed. */
17261 }
17263 /* Walk in inheritance graph order. The search order is not
17264 important, and this avoids multiple walks of virtual bases. */
17266 {
17271 {
17272 /* If there is more than one satisfactory baseclass, then:
17274 [temp.deduct.call]
17276 If they yield more than one possible deduced A, the type
17277 deduction fails.
17279 applies. */
17281 {
17284 }
17287 }
17288 }
17292 }
17294 /* Returns the level of DECL, which declares a template parameter. */
17296 static int
17298 {
17300 {
17310 }
17312 }
17314 /* Decide whether ARG can be unified with PARM, considering only the
17315 cv-qualifiers of each type, given STRICT as documented for unify.
17316 Returns nonzero iff the unification is OK on that basis. */
17318 static int
17320 {
17326 {
17327 /* Although a CVR qualifier is ignored when being applied to a
17328 substituted template parameter ([8.3.2]/1 for example), that
17329 does not allow us to unify "const T" with "int&" because both
17330 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17331 It is ok when we're allowing additional CV qualifiers
17332 at the outer level [14.8.2.1]/3,1st bullet. */
17342 }
17353 }
17355 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17356 void
17358 {
17362 {
17365 }
17366 else
17367 {
17370 }
17371 }
17373 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17374 do { \
17375 if (unify (TP, TA, P, A, S, EP)) \
17376 return 1; \
17377 } while (0);
17379 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17380 expansion at the end of PACKED_PARMS. Returns 0 if the type
17381 deduction succeeds, 1 otherwise. STRICT is the same as in
17382 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17383 call argument list. We'll need to adjust the arguments to make them
17384 types. SUBR tells us if this is from a recursive call to
17385 type_unification_real, or for comparing two template argument
17386 lists. */
17388 static int
17392 {
17393 tree parm
17403 /* Determine the parameter packs we will be deducing from the
17404 pattern, and record their current deductions. */
17407 {
17411 /* Determine the index and level of this parameter pack. */
17414 /* Keep track of the parameter packs and their corresponding
17415 argument packs. */
17418 }
17420 /* Loop through all of the arguments that have not yet been
17421 unified and unify each with the pattern. */
17423 {
17424 tree parm;
17428 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17429 or the element of its argument pack at the current index if
17430 this argument was explicitly specified. */
17432 {
17441 {
17444 }
17446 }
17448 /* If we had explicit template arguments, substitute them into the
17449 pattern before deduction. */
17451 {
17452 /* Some arguments might still be unspecified or dependent. */
17460 NULL_TREE);
17465 }
17466 else
17469 /* Unify the pattern with the current argument. */
17474 /* For each parameter pack, collect the deduced value. */
17476 {
17482 }
17483 }
17485 /* Verify that the results of unification with the parameter packs
17486 produce results consistent with what we've seen before, and make
17487 the deduced argument packs available. */
17489 {
17496 /* By default keep the original deduced argument pack.
17497 If necessary, more specific code is going to update the
17498 resulting deduced argument later down in this function. */
17502 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17503 actually deduce anything. */
17511 {
17512 /* If we had fewer function args than explicit template args,
17513 just use the explicits. */
17518 }
17521 {
17522 tree result;
17523 /* Build the deduced *_ARGUMENT_PACK. */
17525 {
17530 }
17531 else
17536 /* Note the deduced argument packs for this parameter
17537 pack. */
17539 }
17543 {
17544 /* We only had the explicitly-provided arguments before, but
17545 now we have a complete set of arguments. */
17551 }
17552 else
17553 {
17559 /* Inconsistent unification of this parameter pack. */
17561 bad_old_arg,
17562 bad_new_arg);
17563 }
17564 }
17567 }
17569 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17570 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17571 parameters and return value are as for unify. */
17573 static int
17577 {
17578 tree parm_max;
17579 tree arg_max;
17583 /* Our representation of array types uses "N - 1" as the
17584 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17585 not an integer constant. We cannot unify arbitrarily
17586 complex expressions, so we eliminate the MINUS_EXPRs
17587 here. */
17591 {
17594 }
17598 {
17599 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17600 trying to unify the type of a variable with the type
17601 of a template parameter. For example:
17603 template <unsigned int N>
17604 void f (char (&) [N]);
17605 int g();
17606 void h(int i) {
17607 char a[g(i)];
17608 f(a);
17609 }
17611 Here, the type of the ARG will be "int [g(i)]", and
17612 may be a SAVE_EXPR, etc. */
17616 }
17618 /* If only one of the bounds used a MINUS_EXPR, compensate
17619 by adding one to the other bound. */
17622 integer_type_node,
17623 parm_max,
17624 integer_one_node);
17627 integer_type_node,
17628 arg_max,
17629 integer_one_node);
17633 }
17635 /* Deduce the value of template parameters. TPARMS is the (innermost)
17636 set of template parameters to a template. TARGS is the bindings
17637 for those template parameters, as determined thus far; TARGS may
17638 include template arguments for outer levels of template parameters
17639 as well. PARM is a parameter to a template function, or a
17640 subcomponent of that parameter; ARG is the corresponding argument.
17641 This function attempts to match PARM with ARG in a manner
17642 consistent with the existing assignments in TARGS. If more values
17643 are deduced, then TARGS is updated.
17645 Returns 0 if the type deduction succeeds, 1 otherwise. The
17646 parameter STRICT is a bitwise or of the following flags:
17648 UNIFY_ALLOW_NONE:
17649 Require an exact match between PARM and ARG.
17650 UNIFY_ALLOW_MORE_CV_QUAL:
17651 Allow the deduced ARG to be more cv-qualified (by qualification
17652 conversion) than ARG.
17653 UNIFY_ALLOW_LESS_CV_QUAL:
17654 Allow the deduced ARG to be less cv-qualified than ARG.
17655 UNIFY_ALLOW_DERIVED:
17656 Allow the deduced ARG to be a template base class of ARG,
17657 or a pointer to a template base class of the type pointed to by
17658 ARG.
17659 UNIFY_ALLOW_INTEGER:
17660 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17661 case for more information.
17662 UNIFY_ALLOW_OUTER_LEVEL:
17663 This is the outermost level of a deduction. Used to determine validity
17664 of qualification conversions. A valid qualification conversion must
17665 have const qualified pointers leading up to the inner type which
17666 requires additional CV quals, except at the outer level, where const
17667 is not required [conv.qual]. It would be normal to set this flag in
17668 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17669 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17670 This is the outermost level of a deduction, and PARM can be more CV
17671 qualified at this point.
17672 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17673 This is the outermost level of a deduction, and PARM can be less CV
17674 qualified at this point. */
17676 static int
17679 {
17681 tree targ;
17682 tree tparm;
17685 /* I don't think this will do the right thing with respect to types.
17686 But the only case I've seen it in so far has been array bounds, where
17687 signedness is the only information lost, and I think that will be
17688 okay. */
17696 /* We can't deduce anything from this, but we might get all the
17697 template args from other function args. */
17700 /* If PARM uses template parameters, then we can't bail out here,
17701 even if ARG == PARM, since we won't record unifications for the
17702 template parameters. We might need them if we're trying to
17703 figure out which of two things is more specialized. */
17707 /* Handle init lists early, so the rest of the function can assume
17708 we're dealing with a type. */
17710 {
17715 /* Replace T with std::initializer_list<T> for deduction. */
17722 /* We can only deduce from an initializer list argument if the
17723 parameter is std::initializer_list or an array; otherwise this
17724 is a non-deduced context. */
17729 else
17733 {
17740 {
17742 /* It should only be possible to get here for a call. */
17744 elt_strict |= maybe_adjust_types_for_deduction
17747 }
17750 explain_p);
17751 }
17755 {
17756 /* Also deduce from the length of the initializer list. */
17763 }
17765 /* If the std::initializer_list<T> deduction worked, replace the
17766 deduced A with std::initializer_list<A>. */
17768 {
17773 }
17775 }
17777 /* Immediately reject some pairs that won't unify because of
17778 cv-qualification mismatches. */
17781 /* It is the elements of the array which hold the cv quals of an array
17782 type, and the elements might be template type parms. We'll check
17783 when we recurse. */
17785 /* We check the cv-qualifiers when unifying with template type
17786 parameters below. We want to allow ARG `const T' to unify with
17787 PARM `T' for example, when computing which of two templates
17788 is more specialized, for example. */
17802 {
17806 /* In a type which contains a nested-name-specifier, template
17807 argument values cannot be deduced for template parameters used
17808 within the nested-name-specifier. */
17820 /* The PARM is not one we're trying to unify. Just check
17821 to see if it matches ARG. */
17822 {
17827 else
17829 }
17836 /* Check for mixed types and values. */
17844 {
17845 /* ARG must be constructed from a template class or a template
17846 template parameter. */
17850 {
17852 /* An alias template name is never deduced. */
17857 tree parm_parms
17858 = DECL_INNERMOST_TEMPLATE_PARMS
17863 /* The resolution to DR150 makes clear that default
17864 arguments for an N-argument may not be used to bind T
17865 to a template template parameter with fewer than N
17866 parameters. It is not safe to permit the binding of
17867 default arguments as an extension, as that may change
17868 the meaning of a conforming program. Consider:
17870 struct Dense { static const unsigned int dim = 1; };
17872 template <template <typename> class View,
17873 typename Block>
17874 void operator+(float, View<Block> const&);
17876 template <typename Block,
17877 unsigned int Dim = Block::dim>
17878 struct Lvalue_proxy { operator float() const; };
17880 void
17881 test_1d (void) {
17882 Lvalue_proxy<Dense> p;
17883 float b;
17884 b + p;
17885 }
17887 Here, if Lvalue_proxy is permitted to bind to View, then
17888 the global operator+ will be used; if they are not, the
17889 Lvalue_proxy will be converted to float. */
17891 full_argvec,
17893 (explain_p
17894 ? tf_warning_or_error
17901 /* Deduce arguments T, i from TT<T> or TT<i>.
17902 We check each element of PARMVEC and ARGVEC individually
17903 rather than the whole TREE_VEC since they can have
17904 different number of elements. */
17911 /* Check if the parameters end in a pack, making them
17912 variadic. */
17918 /* If the template argument list of P contains a pack
17919 expansion that is not the last template argument, the
17920 entire template argument list is a non-deduced
17921 context. */
17930 {
17935 }
17940 DEDUCE_EXACT,
17943 }
17946 /* Fall through to deduce template name. */
17947 }
17951 {
17952 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17954 /* Simple cases: Value already set, does match or doesn't. */
17959 }
17960 else
17961 {
17962 /* If PARM is `const T' and ARG is only `int', we don't have
17963 a match unless we are allowing additional qualification.
17964 If ARG is `const int' and PARM is just `T' that's OK;
17965 that binds `const int' to `T'. */
17970 /* Consider the case where ARG is `const volatile int' and
17971 PARM is `const T'. Then, T should be `volatile int'. */
17972 arg = cp_build_qualified_type_real
17977 /* Simple cases: Value already set, does match or doesn't. */
17983 /* Make sure that ARG is not a variable-sized array. (Note
17984 that were talking about variable-sized arrays (like
17985 `int[n]'), rather than arrays of unknown size (like
17986 `int[]').) We'll get very confused by such a type since
17987 the bound of the array is not constant, and therefore
17988 not mangleable. Besides, such types are not allowed in
17989 ISO C++, so we can do as we please here. We do allow
17990 them for 'auto' deduction, since that isn't ABI-exposed. */
17994 /* Strip typedefs as in convert_template_argument. */
17996 }
17998 /* If ARG is a parameter pack or an expansion, we cannot unify
17999 against it unless PARM is also a parameter pack. */
18004 /* If the argument deduction results is a METHOD_TYPE,
18005 then there is a problem.
18006 METHOD_TYPE doesn't map to any real C++ type the result of
18007 the deduction can not be of that type. */
18021 {
18022 /* The PARM is not one we're trying to unify. Just check
18023 to see if it matches ARG. */
18029 }
18035 {
18040 }
18042 /* [temp.deduct.type] If, in the declaration of a function template
18043 with a non-type template-parameter, the non-type
18044 template-parameter is used in an expression in the function
18045 parameter-list and, if the corresponding template-argument is
18046 deduced, the template-argument type shall match the type of the
18047 template-parameter exactly, except that a template-argument
18048 deduced from an array bound may be of any integral type.
18049 The non-type parameter might use already deduced type parameters. */
18052 /* Template-parameter dependent expression. Just accept it for now.
18053 It will later be processed in convert_template_argument. */
18054 ;
18059 /* Convert the ARG to the type of PARM; the deduced non-type
18060 template argument must exactly match the types of the
18061 corresponding parameter. */
18064 /* We haven't deduced the type of this parameter yet. Try again
18065 later. */
18067 else
18070 /* If ARG is a parameter pack or an expansion, we cannot unify
18071 against it unless PARM is also a parameter pack. */
18081 {
18082 /* A pointer-to-member constant can be unified only with
18083 another constant. */
18087 /* Just unify the class member. It would be useless (and possibly
18088 wrong, depending on the strict flags) to unify also
18089 PTRMEM_CST_CLASS, because we want to be sure that both parm and
18090 arg refer to the same variable, even if through different
18091 classes. For instance:
18093 struct A { int x; };
18094 struct B : A { };
18096 Unification of &A::x and &B::x must succeed. */
18099 }
18102 {
18106 /* [temp.deduct.call]
18108 A can be another pointer or pointer to member type that can
18109 be converted to the deduced A via a qualification
18110 conversion (_conv.qual_).
18112 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
18113 This will allow for additional cv-qualification of the
18114 pointed-to types if appropriate. */
18117 /* The derived-to-base conversion only persists through one
18118 level of pointers. */
18123 }
18155 /* We have already checked cv-qualification at the top of the
18156 function. */
18160 /* As far as unification is concerned, this wins. Later checks
18161 will invalidate it if necessary. */
18164 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
18165 /* Type INTEGER_CST can come from ordinary constant template args. */
18177 {
18187 /* Check for pack expansions in the parameters. */
18189 {
18191 {
18193 /* We can unify against something with a trailing
18194 parameter pack. */
18196 else
18197 /* [temp.deduct.type]/9: If the template argument list of
18198 P contains a pack expansion that is not the last
18199 template argument, the entire template argument list
18200 is a non-deduced context. */
18202 }
18203 }
18205 /* If we don't have enough arguments to satisfy the parameters
18206 (not counting the pack expression at the end), or we have
18207 too many arguments for a parameter list that doesn't end in
18208 a pack expression, we can't unify. */
18214 /* Unify all of the parameters that precede the (optional)
18215 pack expression. */
18217 {
18222 }
18225 DEDUCE_EXACT,
18228 }
18236 {
18244 }
18249 {
18253 {
18254 /* First, we try to unify the PARM and ARG directly. */
18259 {
18260 /* Fallback to the special case allowed in
18261 [temp.deduct.call]:
18263 If P is a class, and P has the form
18264 template-id, then A can be a derived class of
18265 the deduced A. Likewise, if P is a pointer to
18266 a class of the form template-id, A can be a
18267 pointer to a derived class pointed to by the
18268 deduced A. */
18275 }
18276 }
18280 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18281 Then, we should unify `int' and `U'. */
18283 else
18284 /* There's no chance of unification succeeding. */
18289 }
18296 {
18299 tree a;
18305 /* CV qualifications for methods can never be deduced, they must
18306 match exactly. We need to check them explicitly here,
18307 because type_unification_real treats them as any other
18308 cv-qualified parameter. */
18310 && (!check_cv_quals_for_unify
18330 }
18333 /* Unify a pointer to member with a pointer to member function, which
18334 deduces the type of the member as a function type. */
18336 {
18337 /* Check top-level cv qualifiers */
18345 /* Determine the type of the function we are unifying against. */
18349 }
18368 /* Matched cases are handled by the ARG == PARM test above. */
18372 /* A non-type template parameter that is a variable should be a
18373 an integral constant, in which case, it whould have been
18374 folded into its (constant) value. So we should not be getting
18375 a variable here. */
18386 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18387 or UNDERLYING_TYPE nodes. */
18391 /* Unification fails if we hit an error node. */
18398 /* FALLTHRU */
18401 /* An unresolved overload is a nondeduced context. */
18406 /* We must be looking at an expression. This can happen with
18407 something like:
18409 template <int I>
18410 void foo(S<I>, S<I + 2>);
18412 This is a "nondeduced context":
18414 [deduct.type]
18416 The nondeduced contexts are:
18418 --A type that is a template-id in which one or more of
18419 the template-arguments is an expression that references
18420 a template-parameter.
18422 In these cases, we assume deduction succeeded, but don't
18423 actually infer any unifications. */
18428 else
18430 }
18431 }
18432 #undef RECUR_AND_CHECK_FAILURE
18433 \f
18434 /* Note that DECL can be defined in this translation unit, if
18435 required. */
18437 static void
18439 {
18440 tree clone;
18444 }
18446 /* Called if RESULT is explicitly instantiated, or is a member of an
18447 explicitly instantiated class. */
18449 void
18451 {
18454 /* If this entity has already been written out, it's too late to
18455 make any modifications. */
18459 /* For anonymous namespace we don't need to do anything. */
18461 {
18464 }
18467 /* The TREE_PUBLIC flag for function declarations will have been
18468 set correctly by tsubst. */
18471 /* This might have been set by an earlier implicit instantiation. */
18476 else
18477 {
18480 /* Always make artificials weak. */
18483 /* For WIN32 we also want to put explicit instantiations in
18484 linkonce sections. */
18487 }
18489 /* If EXTERN_P, then this function will not be emitted -- unless
18490 followed by an explicit instantiation, at which point its linkage
18491 will be adjusted. If !EXTERN_P, then this function will be
18492 emitted here. In neither circumstance do we want
18493 import_export_decl to adjust the linkage. */
18495 }
18497 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18498 important template arguments. If any are missing, we check whether
18499 they're important by using error_mark_node for substituting into any
18500 args that were used for partial ordering (the ones between ARGS and END)
18501 and seeing if it bubbles up. */
18503 static bool
18505 {
18510 {
18513 }
18515 {
18519 }
18521 }
18523 /* Given two function templates PAT1 and PAT2, return:
18525 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18526 -1 if PAT2 is more specialized than PAT1.
18527 0 if neither is more specialized.
18529 LEN indicates the number of parameters we should consider
18530 (defaulted parameters should not be considered).
18532 The 1998 std underspecified function template partial ordering, and
18533 DR214 addresses the issue. We take pairs of arguments, one from
18534 each of the templates, and deduce them against each other. One of
18535 the templates will be more specialized if all the *other*
18536 template's arguments deduce against its arguments and at least one
18537 of its arguments *does* *not* deduce against the other template's
18538 corresponding argument. Deduction is done as for class templates.
18539 The arguments used in deduction have reference and top level cv
18540 qualifiers removed. Iff both arguments were originally reference
18541 types *and* deduction succeeds in both directions, an lvalue reference
18542 wins against an rvalue reference and otherwise the template
18543 with the more cv-qualified argument wins for that pairing (if
18544 neither is more cv-qualified, they both are equal). Unlike regular
18545 deduction, after all the arguments have been deduced in this way,
18546 we do *not* verify the deduced template argument values can be
18547 substituted into non-deduced contexts.
18549 The logic can be a bit confusing here, because we look at deduce1 and
18550 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18551 can find template arguments for pat1 to make arg1 look like arg2, that
18552 means that arg2 is at least as specialized as arg1. */
18554 int
18556 {
18569 /* Remove the this parameter from non-static member functions. If
18570 one is a non-static member function and the other is not a static
18571 member function, remove the first parameter from that function
18572 also. This situation occurs for operator functions where we
18573 locate both a member function (with this pointer) and non-member
18574 operator (with explicit first operand). */
18576 {
18581 }
18583 {
18586 {
18587 len--;
18589 }
18590 }
18592 /* If only one is a conversion operator, they are unordered. */
18596 /* Consider the return type for a conversion function */
18598 {
18601 len++;
18602 }
18604 processing_template_decl++;
18610 /* Stop when an ellipsis is seen. */
18612 {
18623 {
18624 /* When both arguments are pack expansions, we need only
18625 unify the patterns themselves. */
18629 /* This is the last comparison we need to do. */
18631 }
18634 {
18638 }
18641 {
18645 }
18651 {
18657 /* Setup the parameter vector, which contains only ARG1. */
18660 /* Setup the argument vector, which contains the remaining
18661 arguments. */
18670 /* We cannot deduce in the other direction, because ARG1 is
18671 a pack expansion but ARG2 is not. */
18673 }
18675 {
18681 /* Setup the parameter vector, which contains only ARG1. */
18684 /* Setup the argument vector, which contains the remaining
18685 arguments. */
18694 /* We cannot deduce in the other direction, because ARG2 is
18695 a pack expansion but ARG1 is not.*/
18697 }
18699 else
18700 {
18701 /* The normal case, where neither argument is a pack
18702 expansion. */
18709 }
18711 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18712 arg2, then arg2 is not as specialized as arg1. */
18718 /* "If, for a given type, deduction succeeds in both directions
18719 (i.e., the types are identical after the transformations above)
18720 and both P and A were reference types (before being replaced with
18721 the type referred to above):
18722 - if the type from the argument template was an lvalue reference and
18723 the type from the parameter template was not, the argument type is
18724 considered to be more specialized than the other; otherwise,
18725 - if the type from the argument template is more cv-qualified
18726 than the type from the parameter template (as described above),
18727 the argument type is considered to be more specialized than the other;
18728 otherwise,
18729 - neither type is more specialized than the other." */
18732 {
18734 {
18737 else
18739 }
18741 {
18746 }
18747 }
18750 /* We've failed to deduce something in either direction.
18751 These must be unordered. */
18756 /* We have already processed all of the arguments in our
18757 handing of the pack expansion type. */
18762 }
18764 /* "In most cases, all template parameters must have values in order for
18765 deduction to succeed, but for partial ordering purposes a template
18766 parameter may remain without a value provided it is not used in the
18767 types being used for partial ordering."
18769 Thus, if we are missing any of the targs1 we need to substitute into
18770 origs1, then pat2 is not as specialized as pat1. This can happen when
18771 there is a nondeduced context. */
18777 processing_template_decl--;
18779 /* All things being equal, if the next argument is a pack expansion
18780 for one function but not for the other, prefer the
18781 non-variadic function. FIXME this is bogus; see c++/41958. */
18785 {
18788 }
18794 else
18796 }
18798 /* Determine which of two partial specializations of TMPL is more
18799 specialized.
18801 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18802 to the first partial specialization. The TREE_VALUE is the
18803 innermost set of template parameters for the partial
18804 specialization. PAT2 is similar, but for the second template.
18806 Return 1 if the first partial specialization is more specialized;
18807 -1 if the second is more specialized; 0 if neither is more
18808 specialized.
18810 See [temp.class.order] for information about determining which of
18811 two templates is more specialized. */
18813 static int
18815 {
18816 tree targs;
18824 /* Just like what happens for functions, if we are ordering between
18825 different class template specializations, we may encounter dependent
18826 types in the arguments, and we need our dependency check functions
18827 to behave correctly. */
18833 {
18836 }
18842 {
18845 }
18848 /* In the case of a tie where at least one of the class templates
18849 has a parameter pack at the end, the template with the most
18850 non-packed parameters wins. */
18852 && any_deductions
18855 {
18861 /* We don't count the pack expansion at the end. */
18871 }
18874 }
18876 /* Return the template arguments that will produce the function signature
18877 DECL from the function template FN, with the explicit template
18878 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18879 also match. Return NULL_TREE if no satisfactory arguments could be
18880 found. */
18882 static tree
18884 {
18888 tree decl_arg_types;
18891 tree arg;
18895 /* Never do unification on the 'this' parameter. */
18916 }
18918 /* Return the innermost template arguments that, when applied to a partial
18919 specialization of TMPL whose innermost template parameters are
18920 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18921 ARGS.
18923 For example, suppose we have:
18925 template <class T, class U> struct S {};
18926 template <class T> struct S<T*, int> {};
18928 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18929 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18930 int}. The resulting vector will be {double}, indicating that `T'
18931 is bound to `double'. */
18933 static tree
18935 {
18937 tree deduced_args;
18938 tree innermost_deduced_args;
18942 {
18946 innermost_deduced_args);
18947 }
18948 else
18961 /* Verify that nondeduced template arguments agree with the type
18962 obtained from argument deduction.
18964 For example:
18966 struct A { typedef int X; };
18967 template <class T, class U> struct C {};
18968 template <class T> struct C<T, typename T::X> {};
18970 Then with the instantiation `C<A, int>', we can deduce that
18971 `T' is `A' but unify () does not check whether `typename T::X'
18972 is `int'. */
18978 /* We only need to check the innermost arguments; the other
18979 arguments will always agree. */
18984 /* Now that we have bindings for all of the template arguments,
18985 ensure that the arguments deduced for the template template
18986 parameters have compatible template parameter lists. See the use
18987 of template_template_parm_bindings_ok_p in fn_type_unification
18988 for more information. */
18993 }
18995 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18996 Return the TREE_LIST node with the most specialized template, if
18997 any. If there is no most specialized template, the error_mark_node
18998 is returned.
19000 Note that this function does not look at, or modify, the
19001 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
19002 returned is one of the elements of INSTANTIATIONS, callers may
19003 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
19004 and retrieve it from the value returned. */
19006 tree
19008 {
19015 {
19021 fate--;
19026 fate++;
19031 {
19032 /* Equally specialized, move to next function. If there
19033 is no next function, nothing's most specialized. */
19038 }
19039 }
19042 /* Now verify that champ is better than everything earlier in the
19043 instantiation list. */
19051 {
19054 }
19056 processing_template_decl--;
19062 }
19064 /* If DECL is a specialization of some template, return the most
19065 general such template. Otherwise, returns NULL_TREE.
19067 For example, given:
19069 template <class T> struct S { template <class U> void f(U); };
19071 if TMPL is `template <class U> void S<int>::f(U)' this will return
19072 the full template. This function will not trace past partial
19073 specializations, however. For example, given in addition:
19075 template <class T> struct S<T*> { template <class U> void f(U); };
19077 if TMPL is `template <class U> void S<int*>::f(U)' this will return
19078 `template <class T> template <class U> S<T*>::f(U)'. */
19080 tree
19082 {
19084 {
19087 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
19088 template friend, or a FIELD_DECL for a capture pack. */
19091 }
19093 /* Look for more and more general templates. */
19095 {
19096 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
19097 (See cp-tree.h for details.) */
19105 /* Stop if we run into an explicitly specialized class template. */
19112 }
19115 }
19117 /* Return the most specialized of the class template partial
19118 specializations which can produce TYPE, a specialization of some class
19119 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
19120 a _TYPE node corresponding to the partial specialization, while the
19121 TREE_PURPOSE is the set of template arguments that must be
19122 substituted into the TREE_TYPE in order to generate TYPE.
19124 If the choice of partial specialization is ambiguous, a diagnostic
19125 is issued, and the error_mark_node is returned. If there are no
19126 partial specializations matching TYPE, then NULL_TREE is
19127 returned, indicating that the primary template should be used. */
19129 static tree
19131 {
19133 tree t;
19134 tree champ;
19143 /* For determining which partial specialization to use, only the
19144 innermost args are interesting. */
19146 {
19149 }
19152 {
19153 tree partial_spec_args;
19154 tree spec_args;
19163 {
19164 /* Discard the outer levels of args, and then substitute in the
19165 template args from the enclosing class. */
19167 partial_spec_args = tsubst_template_args
19170 /* And the same for the partial specialization TEMPLATE_DECL. */
19172 }
19174 partial_spec_args =
19176 partial_spec_args,
19190 partial_spec_args,
19191 args);
19193 {
19198 }
19199 }
19209 {
19212 ;
19213 else
19214 {
19216 {
19219 {
19222 }
19223 }
19225 }
19226 }
19230 {
19233 {
19236 }
19237 }
19240 {
19248 {
19251 }
19254 }
19257 }
19259 /* Explicitly instantiate DECL. */
19261 void
19263 {
19268 /* An error occurred, for which grokdeclarator has already issued
19269 an appropriate message. */
19272 {
19275 }
19281 {
19282 /* There is an asymmetry here in the way VAR_DECLs and
19283 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19284 the latter, the DECL we get back will be marked as a
19285 template instantiation, and the appropriate
19286 DECL_TEMPLATE_INFO will be set up. This does not happen for
19287 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19288 should handle VAR_DECLs as it currently handles
19289 FUNCTION_DECLs. */
19291 {
19294 }
19297 {
19300 }
19302 {
19307 }
19308 }
19310 {
19313 }
19314 else
19317 /* Check for various error cases. Note that if the explicit
19318 instantiation is valid the RESULT will currently be marked as an
19319 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19320 until we get here. */
19323 {
19324 /* DR 259 [temp.spec].
19326 Both an explicit instantiation and a declaration of an explicit
19327 specialization shall not appear in a program unless the explicit
19328 instantiation follows a declaration of the explicit specialization.
19330 For a given set of template parameters, if an explicit
19331 instantiation of a template appears after a declaration of an
19332 explicit specialization for that template, the explicit
19333 instantiation has no effect. */
19335 }
19337 {
19338 /* [temp.spec]
19340 No program shall explicitly instantiate any template more
19341 than once.
19343 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19344 the first instantiation was `extern' and the second is not,
19345 and EXTERN_P for the opposite case. */
19348 /* If an "extern" explicit instantiation follows an ordinary
19349 explicit instantiation, the template is instantiated. */
19352 }
19354 {
19357 }
19359 {
19362 }
19365 ;
19367 {
19370 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19373 }
19374 else
19382 }
19384 static void
19386 {
19392 {
19395 }
19396 }
19398 /* Called from do_type_instantiation through binding_table_foreach to
19399 do recursive instantiation for the type bound in ENTRY. */
19400 static void
19402 {
19408 }
19410 /* Called from do_type_instantiation to instantiate a member
19411 (a member function or a static member variable) of an
19412 explicitly instantiated class template. */
19413 static void
19415 {
19420 }
19422 /* Perform an explicit instantiation of template class T. STORAGE, if
19423 non-null, is the RID for extern, inline or static. COMPLAIN is
19424 nonzero if this is called from the parser, zero if called recursively,
19425 since the standard is unclear (as detailed below). */
19427 void
19429 {
19439 {
19440 tree tmpl =
19444 else
19447 }
19452 {
19455 t);
19457 }
19460 {
19462 {
19464 {
19467 "ISO C++ 1998 forbids the use of %<extern%> on "
19469 }
19470 else
19472 "ISO C++ forbids the use of %qE"
19474 }
19482 else
19483 {
19485 storage);
19487 }
19488 }
19491 {
19492 /* DR 259 [temp.spec].
19494 Both an explicit instantiation and a declaration of an explicit
19495 specialization shall not appear in a program unless the explicit
19496 instantiation follows a declaration of the explicit specialization.
19498 For a given set of template parameters, if an explicit
19499 instantiation of a template appears after a declaration of an
19500 explicit specialization for that template, the explicit
19501 instantiation has no effect. */
19503 }
19505 {
19506 /* [temp.spec]
19508 No program shall explicitly instantiate any template more
19509 than once.
19511 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19512 instantiation was `extern'. If EXTERN_P then the second is.
19513 These cases are OK. */
19520 /* If we've already instantiated the template, just return now. */
19523 }
19531 {
19532 tree tmp;
19534 /* In contrast to implicit instantiation, where only the
19535 declarations, and not the definitions, of members are
19536 instantiated, we have here:
19538 [temp.explicit]
19540 The explicit instantiation of a class template specialization
19541 implies the instantiation of all of its members not
19542 previously explicitly specialized in the translation unit
19543 containing the explicit instantiation.
19545 Of course, we can't instantiate member template classes, since
19546 we don't have any arguments for them. Note that the standard
19547 is unclear on whether the instantiation of the members are
19548 *explicit* instantiations or not. However, the most natural
19549 interpretation is that it should be an explicit instantiation. */
19564 }
19565 }
19567 /* Given a function DECL, which is a specialization of TMPL, modify
19568 DECL to be a re-instantiation of TMPL with the same template
19569 arguments. TMPL should be the template into which tsubst'ing
19570 should occur for DECL, not the most general template.
19572 One reason for doing this is a scenario like this:
19574 template <class T>
19575 void f(const T&, int i);
19577 void g() { f(3, 7); }
19579 template <class T>
19580 void f(const T& t, const int i) { }
19582 Note that when the template is first instantiated, with
19583 instantiate_template, the resulting DECL will have no name for the
19584 first parameter, and the wrong type for the second. So, when we go
19585 to instantiate the DECL, we regenerate it. */
19587 static void
19589 {
19590 /* The arguments used to instantiate DECL, from the most general
19591 template. */
19592 tree args;
19593 tree code_pattern;
19598 /* Make sure that we can see identifiers, and compute access
19599 correctly. */
19603 {
19604 tree decl_parm;
19605 tree pattern_parm;
19606 tree specs;
19620 specs);
19622 /* Merge parameter declarations. */
19625 pattern_parm
19629 {
19630 tree parm_type;
19631 tree attributes;
19636 NULL_TREE);
19642 {
19645 }
19648 }
19649 /* Merge any parameters that match with the function parameter
19650 pack. */
19652 {
19654 tree expanded_types;
19655 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19656 the parameters in this function parameter pack. */
19661 {
19662 tree parm_type;
19663 tree attributes;
19666 /* Rename the parameter to include the index. */
19675 {
19678 }
19680 }
19681 }
19682 /* Merge additional specifiers from the CODE_PATTERN. */
19686 }
19688 {
19696 }
19697 else
19701 }
19703 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19704 substituted to get DECL. */
19706 tree
19708 {
19711 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19712 for the instantiation. This is not always the most general
19713 template. Consider, for example:
19715 template <class T>
19716 struct S { template <class U> void f();
19717 template <> void f<int>(); };
19719 and an instantiation of S<double>::f<int>. We want TD to be the
19720 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19722 more general template. */
19724 /* We must also deal with friend templates. Given:
19726 template <class T> struct S {
19727 template <class U> friend void f() {};
19728 };
19730 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19731 so far as the language is concerned, but that's still
19732 where we get the pattern for the instantiation from. On
19733 other hand, if the definition comes outside the class, say:
19735 template <class T> struct S {
19736 template <class U> friend void f();
19737 };
19738 template <class U> friend void f() {}
19740 we don't need to look any further. That's what the check for
19741 DECL_INITIAL is for. */
19745 {
19746 /* The present template, TD, should not be a definition. If it
19747 were a definition, we should be using it! Note that we
19748 cannot restructure the loop to just keep going until we find
19749 a template with a definition, since that might go too far if
19750 a specialization was declared, but not defined. */
19752 /* Fetch the more general template. */
19754 }
19757 }
19759 /* Returns true if we need to instantiate this template instance even if we
19760 know we aren't going to emit it.. */
19762 bool
19764 {
19765 /* We always instantiate inline functions so that we can inline them. An
19766 explicit instantiation declaration prohibits implicit instantiation of
19767 non-inline functions. With high levels of optimization, we would
19768 normally inline non-inline functions -- but we're not allowed to do
19769 that for "extern template" functions. Therefore, we check
19770 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19774 /* And we need to instantiate static data members so that
19775 their initializers are available in integral constant
19776 expressions. */
19779 }
19781 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19782 instantiate it now, modifying TREE_TYPE (fn). */
19784 void
19786 {
19789 /* Don't instantiate a noexcept-specification from template context. */
19804 {
19808 {
19823 }
19824 else
19828 }
19831 {
19834 else
19836 }
19837 }
19839 /* Produce the definition of D, a _DECL generated from a template. If
19840 DEFER_OK is nonzero, then we don't have to actually do the
19841 instantiation now; we just have to do it sometime. Normally it is
19842 an error if this is an explicit instantiation but D is undefined.
19843 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19844 explicitly instantiated class template. */
19846 tree
19849 {
19851 tree gen_args;
19852 tree args;
19853 tree td;
19854 tree code_pattern;
19855 tree spec;
19856 tree gen_tmpl;
19863 tree fn_context;
19866 /* This function should only be used to instantiate templates for
19867 functions and static member variables. */
19870 /* Variables are never deferred; if instantiation is required, they
19871 are instantiated right away. That allows for better code in the
19872 case that an expression refers to the value of the variable --
19873 if the variable has a constant value the referring expression can
19874 take advantage of that fact. */
19879 /* Don't instantiate cloned functions. Instead, instantiate the
19880 functions they cloned. */
19888 /* D has already been instantiated or explicitly specialized, so
19889 there's nothing for us to do here.
19891 It might seem reasonable to check whether or not D is an explicit
19892 instantiation, and, if so, stop here. But when an explicit
19893 instantiation is deferred until the end of the compilation,
19894 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19895 the instantiation. */
19898 /* Check to see whether we know that this template will be
19899 instantiated in some other file, as with "extern template"
19900 extension. */
19903 /* In general, we do not instantiate such templates. */
19911 /* We should already have the extra args. */
19914 /* And what's in the hash table should match D. */
19918 /* This needs to happen before any tsubsting. */
19924 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19925 for the instantiation. */
19929 /* We should never be trying to instantiate a member of a class
19930 template or partial specialization. */
19935 /* In the case of a friend template whose definition is provided
19936 outside the class, we may have too many arguments. Drop the
19937 ones we don't need. The same is true for specializations. */
19938 args = get_innermost_template_args
19940 else
19944 {
19949 }
19950 else
19951 {
19954 }
19956 /* We may be in the middle of deferred access check. Disable it now. */
19959 /* Unless an explicit instantiation directive has already determined
19960 the linkage of D, remember that a definition is available for
19961 this entity. */
19971 /* If D is a member of an explicitly instantiated class template,
19972 and no definition is available, treat it like an implicit
19973 instantiation. */
19976 {
19977 /* Leave linkage flags alone on instantiations with anonymous
19978 visibility. */
19980 {
19983 }
19985 }
19987 /* Defer all other templates, unless we have been explicitly
19988 forbidden from doing so. */
19990 template. */
19991 ! pattern_defined
19992 /* If it's OK to postpone instantiation, do so. */
19993 || defer_ok
19994 /* If this is a static data member that will be defined
19995 elsewhere, we don't want to instantiate the entire data
19996 member, but we do want to instantiate the initializer so that
19997 we can substitute that elsewhere. */
19999 /* Handle here a deleted function too, avoid generating
20000 its body (c++/61080). */
20002 {
20003 /* The definition of the static data member is now required so
20004 we must substitute the initializer. */
20008 {
20009 tree ns;
20010 tree init;
20019 args,
20022 /* If instantiating the initializer involved instantiating this
20023 again, don't call cp_finish_decl twice. */
20025 {
20026 /* Make sure the initializer is still constant, in case of
20027 circular dependency (template/instantiate6.C). */
20028 const_init
20032 LOOKUP_ONLYCONVERTING);
20033 }
20037 }
20039 /* We restore the source position here because it's used by
20040 add_pending_template. */
20046 /* [temp.explicit]
20048 The definition of a non-exported function template, a
20049 non-exported member function template, or a non-exported
20050 member function or static data member of a class template
20051 shall be present in every translation unit in which it is
20052 explicitly instantiated. */
20056 /* If we're in unevaluated context, we just wanted to get the
20057 constant value; this isn't an odr use, so don't queue
20058 a full instantiation. */
20061 /* ??? Historically, we have instantiated inline functions, even
20062 when marked as "extern template". */
20066 }
20067 /* Tell the repository that D is available in this translation unit
20068 -- and see if it is supposed to be instantiated here. */
20070 {
20071 /* In a PCH file, despite the fact that the repository hasn't
20072 requested instantiation in the PCH it is still possible that
20073 an instantiation will be required in a file that includes the
20074 PCH. */
20077 /* Instantiate inline functions so that the inliner can do its
20078 job, even though we'll not be emitting a copy of this
20079 function. */
20082 }
20088 else
20089 {
20094 }
20096 /* Mark D as instantiated so that recursive calls to
20097 instantiate_decl do not try to instantiate it again. */
20100 /* Regenerate the declaration in case the template has been modified
20101 by a subsequent redeclaration. */
20104 /* We already set the file and line above. Reset them now in case
20105 they changed as a result of calling regenerate_decl_from_template. */
20109 {
20110 tree init;
20113 /* Clear out DECL_RTL; whatever was there before may not be right
20114 since we've reset the type of the declaration. */
20118 /* The initializer is placed in DECL_INITIAL by
20119 regenerate_decl_from_template so we don't need to
20120 push/pop_access_scope again here. Pull it out so that
20121 cp_finish_decl can process it. */
20126 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
20127 initializer. That function will defer actual emission until
20128 we have a chance to determine linkage. */
20131 /* Enter the scope of D so that access-checking works correctly. */
20144 }
20148 {
20150 tree subst_decl;
20151 tree tmpl_parm;
20152 tree spec_parm;
20155 /* Save away the current list, in case we are instantiating one
20156 template from within the body of another. */
20159 /* Set up the list of local specializations. */
20162 /* Set up context. */
20166 else
20169 /* Some typedefs referenced from within the template code need to be
20170 access checked at template instantiation time, i.e now. These
20171 types were added to the template at parsing time. Let's get those
20172 and perform the access checks then. */
20174 gen_args);
20176 /* Create substitution entries for the parameters. */
20181 {
20185 }
20187 {
20189 {
20192 }
20193 else
20194 {
20195 /* Register the (value) argument pack as a specialization of
20196 TMPL_PARM, then move on. */
20199 }
20200 }
20203 /* Substitute into the body of the function. */
20207 else
20208 {
20213 /* Set the current input_location to the end of the function
20214 so that finish_function knows where we are. */
20215 input_location
20218 /* Remember if we saw an infinite loop in the template. */
20219 current_function_infinite_loop
20221 }
20223 /* We don't need the local specializations any more. */
20227 /* Finish the function. */
20231 else
20232 {
20235 }
20239 }
20241 /* We're not deferring instantiation any more. */
20249 out:
20259 }
20261 /* Run through the list of templates that we wish we could
20262 instantiate, and instantiate any we can. RETRIES is the
20263 number of times we retry pending template instantiation. */
20265 void
20267 {
20271 /* Instantiating templates may trigger vtable generation. This in turn
20272 may require further template instantiations. We place a limit here
20273 to avoid infinite loop. */
20275 {
20279 " instantiating %q+D, possibly from virtual table generation"
20283 /* Pretend that we defined it. */
20286 }
20288 do
20289 {
20294 {
20299 {
20300 tree fn;
20303 {
20307 fn;
20315 }
20318 }
20319 else
20320 {
20323 {
20324 instantiation
20330 }
20334 }
20337 /* If INSTANTIATION has been instantiated, then we don't
20338 need to consider it again in the future. */
20340 else
20341 {
20344 }
20347 }
20349 }
20353 }
20355 /* Substitute ARGVEC into T, which is a list of initializers for
20356 either base class or a non-static data member. The TREE_PURPOSEs
20357 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20358 instantiate_decl. */
20360 static tree
20362 {
20366 {
20367 tree decl;
20368 tree init;
20374 {
20375 tree expr;
20376 tree arg;
20378 /* Expand the base class expansion type into separate base
20379 classes. */
20381 tf_warning_or_error,
20382 NULL_TREE);
20386 /* We'll be building separate TREE_LISTs of arguments for
20387 each base. */
20393 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20394 expand each argument in the TREE_VALUE of t. */
20401 /* VOID_TYPE_NODE is used to indicate
20402 value-initialization. */
20403 {
20406 }
20407 else
20408 {
20409 /* Substitute parameter packs into each argument in the
20410 TREE_LIST. */
20413 {
20414 tree expanded_exprs;
20416 /* Expand the argument. */
20418 expanded_exprs
20420 tf_warning_or_error,
20421 NULL_TREE);
20425 /* Prepend each of the expanded expressions to the
20426 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20428 {
20433 }
20434 }
20437 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20438 since we built them backwards. */
20440 {
20443 }
20444 }
20445 }
20448 {
20450 {
20454 }
20455 else
20456 {
20457 tree tmp;
20472 /* If we had an initializer but it instantiated to nothing,
20473 value-initialize the object. This will only occur when
20474 the initializer was a pack expansion where the parameter
20475 packs used in that expansion were of length zero. */
20478 }
20481 {
20485 }
20486 }
20487 }
20489 }
20491 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20493 static void
20495 {
20500 else
20502 }
20504 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20505 is the instantiation (which should have been created with
20506 start_enum) and ARGS are the template arguments to use. */
20508 static void
20510 {
20511 tree e;
20517 {
20518 tree value;
20519 tree decl;
20522 /* Note that in a template enum, the TREE_VALUE is the
20523 CONST_DECL, not the corresponding INTEGER_CST. */
20528 /* Give this enumeration constant the correct access. */
20531 /* Actually build the enumerator itself. */
20532 build_enumerator
20534 }
20544 }
20546 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20547 its type -- but without substituting the innermost set of template
20548 arguments. So, innermost set of template parameters will appear in
20549 the type. */
20551 tree
20553 {
20554 tree fn_type;
20555 tree tmpl;
20556 tree targs;
20557 tree tparms;
20565 /* There should be as many levels of arguments as there are levels
20566 of parameters. */
20572 /* No substitution is necessary. */
20573 ;
20574 else
20575 {
20577 tree partial_args;
20579 /* Replace the innermost level of the TARGS with NULL_TREEs to
20580 let tsubst know not to substitute for those parameters. */
20589 /* Make sure that we can see identifiers, and compute access
20590 correctly. */
20594 /* Now, do the (partial) substitution to figure out the
20595 appropriate function type. */
20599 /* Substitute into the template parameters to obtain the real
20600 innermost set of parameters. This step is important if the
20601 innermost set of template parameters contains value
20602 parameters whose types depend on outer template parameters. */
20607 }
20610 }
20612 /* Return truthvalue if we're processing a template different from
20613 the last one involved in diagnostics. */
20614 int
20616 {
20618 }
20620 /* Remember current template involved in diagnostics. */
20621 void
20623 {
20625 }
20629 {
20631 }
20633 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20634 type. Return zero for ok, nonzero for disallowed. Issue error and
20635 warning messages under control of COMPLAIN. */
20637 static int
20639 {
20656 {
20659 else
20661 type);
20662 }
20664 }
20666 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20667 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20669 static bool
20671 {
20672 tree scope;
20674 /* [temp.dep.type]
20676 A type is dependent if it is:
20678 -- a template parameter. Template template parameters are types
20679 for us (since TYPE_P holds true for them) so we handle
20680 them here. */
20684 /* -- a qualified-id with a nested-name-specifier which contains a
20685 class-name that names a dependent type or whose unqualified-id
20686 names a dependent type. */
20689 /* -- a cv-qualified type where the cv-unqualified type is
20690 dependent. */
20692 /* -- a compound type constructed from any dependent type. */
20702 {
20703 tree arg_type;
20708 arg_type;
20713 }
20714 /* -- an array type constructed from any dependent type or whose
20715 size is specified by a constant expression that is
20716 value-dependent.
20718 We checked for type- and value-dependence of the bounds in
20719 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20721 {
20726 }
20728 /* -- a template-id in which either the template name is a template
20729 parameter ... */
20732 /* ... or any of the template arguments is a dependent type or
20733 an expression that is type-dependent or value-dependent. */
20735 && (any_dependent_template_arguments_p
20739 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20740 dependent; if the argument of the `typeof' expression is not
20741 type-dependent, then it should already been have resolved. */
20747 /* A template argument pack is dependent if any of its packed
20748 arguments are. */
20750 {
20756 }
20758 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20759 be template parameters. */
20763 /* The standard does not specifically mention types that are local
20764 to template functions or local classes, but they should be
20765 considered dependent too. For example:
20767 template <int I> void f() {
20768 enum E { a = I };
20769 S<sizeof (E)> s;
20770 }
20772 The size of `E' cannot be known until the value of `I' has been
20773 determined. Therefore, `E' must be considered dependent. */
20777 /* Don't use type_dependent_expression_p here, as it can lead
20778 to infinite recursion trying to determine whether a lambda
20779 nested in a lambda is dependent (c++/47687). */
20783 && (any_dependent_template_arguments_p
20787 /* Other types are non-dependent. */
20789 }
20791 /* Returns TRUE if TYPE is dependent, in the sense of
20792 [temp.dep.type]. Note that a NULL type is considered dependent. */
20794 bool
20796 {
20797 /* If there are no template parameters in scope, then there can't be
20798 any dependent types. */
20800 {
20801 /* If we are not processing a template, then nobody should be
20802 providing us with a dependent type. */
20806 }
20808 /* If the type is NULL, we have not computed a type for the entity
20809 in question; in that case, the type is dependent. */
20813 /* Erroneous types can be considered non-dependent. */
20817 /* If we have not already computed the appropriate value for TYPE,
20818 do so now. */
20820 {
20823 }
20826 }
20828 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20829 lookup. In other words, a dependent type that is not the current
20830 instantiation. */
20832 bool
20834 {
20837 }
20839 /* T is a SCOPE_REF; return whether we need to consider it
20840 instantiation-dependent so that we can check access at instantiation
20841 time even though we know which member it resolves to. */
20843 static bool
20845 {
20851 else
20853 }
20855 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20856 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20857 expression. */
20859 /* Note that this predicate is not appropriate for general expressions;
20860 only constant expressions (that satisfy potential_constant_expression)
20861 can be tested for value dependence. */
20863 bool
20865 {
20869 /* A name declared with a dependent type. */
20874 {
20876 /* A name that has not been looked up -- must be dependent. */
20880 /* A non-type template parm. */
20884 /* A non-type template parm. */
20890 /* A constant with literal type and is initialized
20891 with an expression that is value-dependent.
20893 Note that a non-dependent parenthesized initializer will have
20894 already been replaced with its constant value, so if we see
20895 a TREE_LIST it must be dependent. */
20908 /* These expressions are value-dependent if the type to which
20909 the cast occurs is dependent or the expression being casted
20910 is value-dependent. */
20911 {
20917 /* A functional cast has a list of operands. */
20920 {
20921 /* If there are no operands, it must be an expression such
20922 as "int()". This should not happen for aggregate types
20923 because it would form non-constant expressions. */
20928 }
20934 }
20939 /* FALLTHRU */
20942 /* A `sizeof' expression is value-dependent if the operand is
20943 type-dependent or is a pack expansion. */
20952 /* An 'encode' expression is value-dependent if the operand is
20953 type-dependent. */
20962 /* All instantiation-dependent expressions should also be considered
20963 value-dependent. */
20971 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20972 is value-dependent. */
20973 {
20982 }
20985 {
20989 }
21000 {
21004 }
21007 {
21014 {
21016 /* In a call to a constexpr member function, look through the
21017 implicit ADDR_EXPR on the object argument so that it doesn't
21018 cause the call to be considered value-dependent. We also
21019 look through it in potential_constant_expression. */
21026 }
21028 }
21031 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
21032 type-dependent. */
21036 {
21038 tree val;
21043 }
21046 /* Treat a GNU statement expression as dependent to avoid crashing
21047 under fold_non_dependent_expr; it can't be constant. */
21051 /* A constant expression is value-dependent if any subexpression is
21052 value-dependent. */
21054 {
21061 {
21065 {
21068 /* In some cases, some of the operands may be missing.l
21069 (For example, in the case of PREDECREMENT_EXPR, the
21070 amount to increment by may be missing.) That doesn't
21071 make the expression dependent. */
21074 }
21075 }
21079 }
21081 }
21083 /* The expression is not value-dependent. */
21085 }
21087 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
21088 [temp.dep.expr]. Note that an expression with no type is
21089 considered dependent. Other parts of the compiler arrange for an
21090 expression with type-dependent subexpressions to have no type, so
21091 this function doesn't have to be fully recursive. */
21093 bool
21095 {
21102 /* An unresolved name is always dependent. */
21106 /* Some expression forms are never type-dependent. */
21119 /* The types of these expressions depends only on the type to which
21120 the cast occurs. */
21129 /* The types of these expressions depends only on the type created
21130 by the expression. */
21133 {
21134 /* For NEW_EXPR tree nodes created inside a template, either
21135 the object type itself or a TREE_LIST may appear as the
21136 operand 1. */
21139 /* This is an array type. We need to check array dimensions
21140 as well. */
21142 || value_dependent_expression_p
21144 else
21146 }
21149 {
21153 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
21154 contains an identifier associated by name lookup with one or more
21155 declarations declared with a dependent type, or...a
21156 nested-name-specifier or qualified-id that names a member of an
21157 unknown specialization. */
21160 }
21165 && (any_dependent_template_arguments_p
21177 {
21178 tree elt;
21182 {
21185 }
21187 }
21189 /* A static data member of the current instantiation with incomplete
21190 array type is type-dependent, as the definition and specializations
21191 can have different bounds. */
21198 /* An array of unknown bound depending on a variadic parameter, eg:
21200 template<typename... Args>
21201 void foo (Args... args)
21202 {
21203 int arr[] = { args... };
21204 }
21206 template<int... vals>
21207 void bar ()
21208 {
21209 int arr[] = { vals... };
21210 }
21212 If the array has no length and has an initializer, it must be that
21213 we couldn't determine its length in cp_complete_array_type because
21214 it is dependent. */
21222 {
21227 {
21233 }
21234 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
21238 /* Always dependent, on the number of arguments if nothing else. */
21243 {
21248 }
21251 {
21256 }
21261 {
21265 }
21267 }
21272 }
21274 /* walk_tree callback function for instantiation_dependent_expression_p,
21275 below. Returns non-zero if a dependent subexpression is found. */
21277 static tree
21280 {
21282 {
21283 /* We don't have to worry about decltype currently because decltype
21284 of an instantiation-dependent expr is a dependent type. This
21285 might change depending on the resolution of DR 1172. */
21288 }
21291 {
21292 /* Don't treat an argument list as dependent just because it has no
21293 TREE_TYPE. */
21300 /* A constant with a dependent initializer is dependent. */
21308 /* Handle expressions with type operands. */
21313 {
21318 {
21321 else
21322 {
21325 }
21326 }
21328 }
21340 /* In a template, finish_class_member_access_expr creates a
21341 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21342 type-dependent, so that we can check access control at
21343 instantiation time (PR 42277). See also Core issue 1273. */
21350 else
21353 /* Treat statement-expressions as dependent. */
21359 }
21363 else
21365 }
21367 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21368 sense defined by the ABI:
21370 "An expression is instantiation-dependent if it is type-dependent
21371 or value-dependent, or it has a subexpression that is type-dependent
21372 or value-dependent." */
21374 bool
21376 {
21377 tree result;
21388 }
21390 /* Like type_dependent_expression_p, but it also works while not processing
21391 a template definition, i.e. during substitution or mangling. */
21393 bool
21395 {
21401 }
21403 /* Returns TRUE if ARGS contains a type-dependent expression. */
21405 bool
21407 {
21409 tree arg;
21412 {
21415 }
21417 }
21419 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21420 expressions) contains any type-dependent expressions. */
21422 bool
21424 {
21430 }
21432 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21433 expressions) contains any value-dependent expressions. */
21435 bool
21437 {
21443 }
21445 /* Returns TRUE if the ARG (a template argument) is dependent. */
21447 bool
21449 {
21453 /* Assume a template argument that was wrongly written by the user
21454 is dependent. This is consistent with what
21455 any_dependent_template_arguments_p [that calls this function]
21456 does. */
21467 {
21471 {
21474 }
21477 }
21480 else
21483 }
21485 /* Returns true if ARGS (a collection of template arguments) contains
21486 any types that require structural equality testing. */
21488 bool
21490 {
21500 {
21503 {
21509 {
21510 /* Look inside the argument pack. */
21513 }
21516 {
21529 }
21530 }
21531 }
21534 }
21536 /* Returns true if ARGS (a collection of template arguments) contains
21537 any dependent arguments. */
21539 bool
21541 {
21551 {
21556 }
21559 }
21561 /* Returns TRUE if the template TMPL is dependent. */
21563 bool
21565 {
21567 {
21569 {
21573 }
21575 }
21577 /* Template template parameters are dependent. */
21581 /* So are names that have not been looked up. */
21584 /* So are member templates of dependent classes. */
21588 }
21590 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21592 bool
21594 {
21597 }
21599 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21600 is dependent. */
21602 bool
21604 {
21611 {
21632 {
21636 }
21640 {
21644 {
21649 }
21650 }
21651 }
21654 }
21656 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21657 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21658 no such TYPE can be found. Note that this function peers inside
21659 uninstantiated templates and therefore should be used only in
21660 extremely limited situations. ONLY_CURRENT_P restricts this
21661 peering to the currently open classes hierarchy (which is required
21662 when comparing types). */
21664 tree
21666 {
21667 tree scope;
21668 tree name;
21669 tree decl;
21671 tree pushed_scope;
21672 tree result;
21677 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21678 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21679 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21680 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21681 identifier of the TYPENAME_TYPE anymore.
21682 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21683 TYPENAME_TYPE instead, we avoid messing up with a possible
21684 typedef variant case. */
21687 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21688 it first before we can figure out what NAME refers to. */
21690 {
21692 /* Given a class template A with a dependent base with nested type C,
21693 typedef typename A::C::C C will land us here, as trying to resolve
21694 the initial A::C leads to the local C typedef, which leads back to
21695 A::C::C. So we break the recursion now. */
21697 else
21699 }
21700 /* If we don't know what SCOPE refers to, then we cannot resolve the
21701 TYPENAME_TYPE. */
21704 /* If the SCOPE is a template type parameter, we have no way of
21705 resolving the name. */
21708 /* If the SCOPE is not the current instantiation, there's no reason
21709 to look inside it. */
21712 /* If this is a typedef, we don't want to look inside (c++/11987). */
21715 /* If SCOPE isn't the template itself, it will not have a valid
21716 TYPE_FIELDS list. */
21718 /* scope is either the template itself or a compatible instantiation
21719 like X<T>, so look up the name in the original template. */
21721 else
21722 /* scope is a partial instantiation, so we can't do the lookup or we
21723 will lose the template arguments. */
21725 /* Enter the SCOPE so that name lookup will be resolved as if we
21726 were in the class definition. In particular, SCOPE will no
21727 longer be considered a dependent type. */
21729 /* Look up the declaration. */
21731 tf_warning_or_error);
21735 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21736 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21741 {
21745 }
21748 {
21749 tree tmpl;
21750 tree args;
21751 /* Obtain the template and the arguments. */
21754 /* Instantiate the template. */
21760 }
21762 /* Leave the SCOPE. */
21766 /* If we failed to resolve it, return the original typename. */
21770 /* If lookup found a typename type, resolve that too. */
21772 {
21773 /* Ill-formed programs can cause infinite recursion here, so we
21774 must catch that. */
21778 }
21780 /* Qualify the resulting type. */
21786 }
21788 /* EXPR is an expression which is not type-dependent. Return a proxy
21789 for EXPR that can be used to compute the types of larger
21790 expressions containing EXPR. */
21792 tree
21794 {
21795 tree inner_expr;
21797 #ifdef ENABLE_CHECKING
21798 /* Try to get a constant value for all non-dependent expressions in
21799 order to expose bugs in *_dependent_expression_p and constexpr. */
21802 #endif
21804 /* Preserve OVERLOADs; the functions must be available to resolve
21805 types. */
21816 /* There is no need to return a proxy for a variable. */
21819 /* Preserve string constants; conversions from string constants to
21820 "char *" are allowed, even though normally a "const char *"
21821 cannot be used to initialize a "char *". */
21824 /* Preserve void and arithmetic constants, as an optimization -- there is no
21825 reason to create a new node. */
21830 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21831 There is at least one place where we want to know that a
21832 particular expression is a throw-expression: when checking a ?:
21833 expression, there are special rules if the second or third
21834 argument is a throw-expression. */
21838 /* Don't wrap an initializer list, we need to be able to look inside. */
21842 /* Don't wrap a dummy object, we need to be able to test for it. */
21861 /* If the type is unknown, it can't really be non-dependent */
21864 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21866 }
21868 /* ARGS is a vector of expressions as arguments to a function call.
21869 Replace the arguments with equivalent non-dependent expressions.
21870 This modifies ARGS in place. */
21872 void
21874 {
21876 tree arg;
21879 {
21883 }
21884 }
21886 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21887 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21888 parms. */
21890 static tree
21892 {
21905 }
21907 tree
21909 {
21911 }
21913 tree
21915 {
21917 }
21919 /* Given type ARG, return std::initializer_list<ARG>. */
21921 static tree
21923 {
21924 tree std_init_list = namespace_binding
21926 tree argvec;
21928 {
21932 }
21937 }
21939 /* Replace auto in TYPE with std::initializer_list<auto>. */
21941 static tree
21943 {
21950 }
21952 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21953 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21955 tree
21957 {
21958 tree targs;
21964 /* Defining a subset of type-dependent expressions that we can deduce
21965 from ahead of time isn't worth the trouble. */
21968 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21969 with either a new invented type template parameter U or, if the
21970 initializer is a braced-init-list (8.5.4), with
21971 std::initializer_list<U>. */
21979 {
21985 {
21988 }
21989 }
21990 else
21991 {
22002 {
22004 /* Try again at instantiation time. */
22007 /* If type is error_mark_node a diagnostic must have been
22008 emitted by now. Also, having a mention to '<type error>'
22009 in the diagnostic is not really useful to the user. */
22010 {
22014 else
22016 }
22018 }
22019 }
22021 /* If the list of declarators contains more than one declarator, the type
22022 of each declared variable is determined as described above. If the
22023 type deduced for the template parameter U is not the same in each
22024 deduction, the program is ill-formed. */
22027 {
22033 else
22037 }
22043 }
22045 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
22046 result. */
22048 tree
22050 {
22051 tree argvec;
22058 /* For a late-specified return type in a template type-parameter, we
22059 need to add a dummy argument level for its parmlist. */
22060 argvec = add_to_template_args
22065 }
22067 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
22068 'decltype(auto)'. */
22070 bool
22072 {
22077 else
22079 }
22081 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
22082 a use of `auto'. Returns NULL_TREE otherwise. */
22084 tree
22086 {
22088 }
22090 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
22091 'decltype(auto)' or a concept. */
22093 bool
22095 {
22097 }
22099 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
22100 a concept identifier) iff TYPE contains a use of a generic type. Returns
22101 NULL_TREE otherwise. */
22103 tree
22105 {
22107 }
22110 /* For a given template T, return the vector of typedefs referenced
22111 in T for which access check is needed at T instantiation time.
22112 T is either a FUNCTION_DECL or a RECORD_TYPE.
22113 Those typedefs were added to T by the function
22114 append_type_to_template_for_access_check. */
22118 {
22119 tree ti;
22130 {
22135 }
22138 }
22140 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
22141 tied to T. That list of typedefs will be access checked at
22142 T instantiation time.
22143 T is either a FUNCTION_DECL or a RECORD_TYPE.
22144 TYPE_DECL is a TYPE_DECL node representing a typedef.
22145 SCOPE is the scope through which TYPE_DECL is accessed.
22146 LOCATION is the location of the usage point of TYPE_DECL.
22148 This function is a subroutine of
22149 append_type_to_template_for_access_check. */
22151 static void
22153 tree type_decl,
22154 tree scope,
22155 location_t location)
22156 {
22157 qualified_typedef_usage_t typedef_usage;
22158 tree ti;
22165 && type_decl
22179 }
22181 /* Append TYPE_DECL to the template TEMPL.
22182 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
22183 At TEMPL instanciation time, TYPE_DECL will be checked to see
22184 if it can be accessed through SCOPE.
22185 LOCATION is the location of the usage point of TYPE_DECL.
22187 e.g. consider the following code snippet:
22189 class C
22190 {
22191 typedef int myint;
22192 };
22194 template<class U> struct S
22195 {
22196 C::myint mi; // <-- usage point of the typedef C::myint
22197 };
22199 S<char> s;
22201 At S<char> instantiation time, we need to check the access of C::myint
22202 In other words, we need to check the access of the myint typedef through
22203 the C scope. For that purpose, this function will add the myint typedef
22204 and the scope C through which its being accessed to a list of typedefs
22205 tied to the template S. That list will be walked at template instantiation
22206 time and access check performed on each typedefs it contains.
22207 Note that this particular code snippet should yield an error because
22208 myint is private to C. */
22210 void
22212 tree type_decl,
22213 tree scope,
22214 location_t location)
22215 {
22221 /* Make sure we don't append the type to the template twice. */
22228 }
22230 /* Convert the generic type parameters in PARM that match the types given in the
22231 range [START_IDX, END_IDX) from the current_template_parms into generic type
22232 packs. */
22234 tree
22236 {
22247 {
22248 /* Create a distinct parameter pack type from the current parm and add it
22249 to the replacement args to tsubst below into the generic function
22250 parameter. */
22265 }
22271 /* If there are more levels then build up the replacement with the outer
22272 template parms. */
22276 replacement);
22279 }
22282 /* Set up the hash tables for template instantiations. */
22284 void
22286 {
22288 hash_specialization,
22289 eq_specializations,
22290 ggc_free);
22292 hash_specialization,
22293 eq_specializations,
22294 ggc_free);
22295 }
22297 /* Print stats about the template hash tables for -fstats. */
22299 void
22301 {
22310 }