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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". */
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
61 };
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
81 /* True if we've recursed into fn_type_unification too many times. */
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
92 htab_t decl_specializations;
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
139 tree);
202 location_t);
210 /* Make the current scope suitable for access checking when we are
211 processing T. T can be FUNCTION_DECL for instantiated function
212 template, VAR_DECL for static member variable, or TYPE_DECL for
213 alias template (needed by instantiate_decl). */
215 static void
217 {
225 else
229 {
230 saved_access_scope = tree_cons
233 }
234 }
236 /* Restore the scope set up by push_access_scope. T is the node we
237 are processing. */
239 static void
241 {
243 {
246 }
250 else
252 }
254 /* Do any processing required when DECL (a member template
255 declaration) is finished. Returns the TEMPLATE_DECL corresponding
256 to DECL, unless it is a specialization, in which case the DECL
257 itself is returned. */
259 tree
261 {
268 {
269 tree type;
277 {
281 }
283 }
287 {
289 {
292 }
293 else
295 }
296 else
300 }
302 /* Create a template info node. */
304 tree
306 {
311 }
313 /* Return the template info node corresponding to T, whatever T is. */
315 tree
317 {
335 }
337 /* Returns the template nesting level of the indicated class TYPE.
339 For example, in:
340 template <class T>
341 struct A
342 {
343 template <class U>
344 struct B {};
345 };
347 A<T>::B<U> has depth two, while A<T> has depth one.
348 Both A<T>::B<int> and A<int>::B<U> have depth one, if
349 they are instantiations, not specializations.
351 This function is guaranteed to return 0 if passed NULL_TREE so
352 that, for example, `template_class_depth (current_class_type)' is
353 always safe. */
355 int
357 {
364 {
370 }
373 }
375 /* Subroutine of maybe_begin_member_template_processing.
376 Returns true if processing DECL needs us to push template parms. */
378 static bool
380 {
386 }
388 /* Subroutine of maybe_begin_member_template_processing.
389 Push the template parms in PARMS, starting from LEVELS steps into the
390 chain, and ending at the beginning, since template parms are listed
391 innermost first. */
393 static void
395 {
403 current_template_parms
409 NULL);
411 {
420 {
427 {
428 /* Make a CONST_DECL as is done in process_template_parm.
429 It is ugly that we recreate this here; the original
430 version built in process_template_parm is no longer
431 available. */
441 }
446 }
447 }
448 }
450 /* Restore the template parameter context for a member template, a
451 friend template defined in a class definition, or a non-template
452 member of template class. */
454 void
456 {
457 tree parms;
467 {
472 {
475 }
478 }
480 /* Remember how many levels of template parameters we pushed so that
481 we can pop them later. */
483 }
485 /* Undo the effects of maybe_begin_member_template_processing. */
487 void
489 {
498 {
502 }
503 }
505 /* Return a new template argument vector which contains all of ARGS,
506 but has as its innermost set of arguments the EXTRA_ARGS. */
508 static tree
510 {
511 tree new_args;
529 }
531 /* Like add_to_template_args, but only the outermost ARGS are added to
532 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
533 (EXTRA_ARGS) levels are added. This function is used to combine
534 the template arguments from a partial instantiation with the
535 template arguments used to attain the full instantiation from the
536 partial instantiation. */
538 static tree
540 {
541 tree new_args;
543 /* If there are more levels of EXTRA_ARGS than there are ARGS,
544 something very fishy is going on. */
547 /* If *all* the new arguments will be the EXTRA_ARGS, just return
548 them. */
552 /* For the moment, we make ARGS look like it contains fewer levels. */
557 /* Now, we restore ARGS to its full dimensions. */
561 }
563 /* Return the N levels of innermost template arguments from the ARGS. */
565 tree
567 {
568 tree new_args;
574 /* If N is 1, just return the innermost set of template arguments. */
578 /* If we're not removing anything, just return the arguments we were
579 given. */
585 /* Make a new set of arguments, not containing the outer arguments. */
592 }
594 /* The inverse of get_innermost_template_args: Return all but the innermost
595 EXTRA_LEVELS levels of template arguments from the ARGS. */
597 static tree
599 {
600 tree new_args;
606 /* If N is 1, just return the outermost set of template arguments. */
610 /* If we're not removing anything, just return the arguments we were
611 given. */
616 /* Make a new set of arguments, not containing the inner arguments. */
623 }
625 /* We've got a template header coming up; push to a new level for storing
626 the parms. */
628 void
630 {
631 /* We use a non-tag-transparent scope here, which causes pushtag to
632 put tags in this scope, rather than in the enclosing class or
633 namespace scope. This is the right thing, since we want
634 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
635 global template class, push_template_decl handles putting the
636 TEMPLATE_DECL into top-level scope. For a nested template class,
637 e.g.:
639 template <class T> struct S1 {
640 template <class T> struct S2 {};
641 };
643 pushtag contains special code to call pushdecl_with_scope on the
644 TEMPLATE_DECL for S2. */
649 }
651 /* This routine is called when a specialization is declared. If it is
652 invalid to declare a specialization here, an error is reported and
653 false is returned, otherwise this routine will return true. */
655 static bool
657 {
660 /* [temp.expl.spec]
662 An explicit specialization shall be declared in the namespace of
663 which the template is a member, or, for member templates, in the
664 namespace of which the enclosing class or enclosing class
665 template is a member. An explicit specialization of a member
666 function, member class or static data member of a class template
667 shall be declared in the namespace of which the class template
668 is a member. */
670 {
673 }
675 /* [temp.expl.spec]
677 In an explicit specialization declaration for a member of a class
678 template or a member template that appears in namespace scope,
679 the member template and some of its enclosing class templates may
680 remain unspecialized, except that the declaration shall not
681 explicitly specialize a class member template if its enclosing
682 class templates are not explicitly specialized as well. */
684 {
687 }
690 }
692 /* We've just seen template <>. */
694 bool
696 {
700 }
702 /* Called at then end of processing a declaration preceded by
703 template<>. */
705 void
707 {
710 }
712 /* Any template <>'s that we have seen thus far are not referring to a
713 function specialization. */
715 void
717 {
720 }
722 /* We've just seen a template header. If SPECIALIZATION is nonzero,
723 it was of the form template <>. */
725 static void
727 {
729 template_header_count++;
730 }
732 /* We're beginning an explicit instantiation. */
734 void
736 {
739 }
742 void
744 {
747 }
749 /* An explicit specialization or partial specialization of TMPL is being
750 declared. Check that the namespace in which the specialization is
751 occurring is permissible. Returns false iff it is invalid to
752 specialize TMPL in the current namespace. */
754 static bool
756 {
759 /* [tmpl.expl.spec]
761 An explicit specialization shall be declared in the namespace of
762 which the template is a member, or, for member templates, in the
763 namespace of which the enclosing class or enclosing class
764 template is a member. An explicit specialization of a member
765 function, member class or static data member of a class template
766 shall be declared in the namespace of which the class template is
767 a member. */
770 {
773 }
775 /* Same or super-using namespace. */
777 else
778 {
782 }
783 }
785 /* SPEC is an explicit instantiation. Check that it is valid to
786 perform this explicit instantiation in the current namespace. */
788 static void
790 {
791 tree ns;
793 /* DR 275: An explicit instantiation shall appear in an enclosing
794 namespace of its template. */
800 }
802 /* The TYPE is being declared. If it is a template type, that means it
803 is a partial specialization. Do appropriate error-checking. */
805 tree
807 {
808 tree context;
813 /* A lambda that appears in specialization context is not itself a
814 specialization. */
819 {
823 }
828 {
833 else
836 }
838 {
839 /* This is for ordinary explicit specialization and partial
840 specialization of a template class such as:
842 template <> class C<int>;
844 or:
846 template <class T> class C<T*>;
848 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
852 {
857 {
861 }
862 }
868 /* Trying to define a specialization either without a template<> header
869 or in an inappropriate place. We've already given an error, so just
870 bail now so we don't actually define the specialization. */
872 }
878 {
879 /* This is for an explicit specialization of member class
880 template according to [temp.expl.spec/18]:
882 template <> template <class U> class C<int>::D;
884 The context `C<int>' must be an implicit instantiation.
885 Otherwise this is just a member class template declared
886 earlier like:
888 template <> class C<int> { template <class U> class D; };
889 template <> template <class U> class C<int>::D;
891 In the first case, `C<int>::D' is a specialization of `C<T>::D'
892 while in the second case, `C<int>::D' is a primary template
893 and `C<T>::D' may not exist. */
897 {
898 tree t;
903 {
906 }
908 /* Check for invalid specialization after instantiation:
910 template <> template <> class C<int>::D<int>;
911 template <> template <class U> class C<int>::D; */
915 {
918 {
919 /* We already have a full specialization of this partial
920 instantiation. Reassign it to the new member
921 specialization template. */
922 spec_entry elt;
939 }
941 /* But if we've had an implicit instantiation, that's a
942 problem ([temp.expl.spec]/6). */
945 }
947 /* Mark TYPE as a specialization. And as a result, we only
948 have one level of template argument for the innermost
949 class template. */
954 }
955 }
957 {
958 /* Someday C++0x may allow for enum template specialization. */
963 else
964 {
967 }
968 }
971 }
973 /* Returns nonzero if we can optimize the retrieval of specializations
974 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
975 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
979 {
982 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
983 parameter. */
985 /* The optimized lookup depends on the fact that the
986 template arguments for the member function template apply
987 purely to the containing class, which is not true if the
988 containing class is an explicit or partial
989 specialization. */
993 /* It is possible to have a template that is not a member
994 template and is not a member of a template class:
996 template <typename T>
997 struct S { friend A::f(); };
999 Here, the friend function is a template, but the context does
1000 not have template information. The optimized lookup relies
1001 on having ARGS be the template arguments for both the class
1002 and the function template. */
1004 }
1006 /* Retrieve the specialization (in the sense of [temp.spec] - a
1007 specialization is either an instantiation or an explicit
1008 specialization) of TMPL for the given template ARGS. If there is
1009 no such specialization, return NULL_TREE. The ARGS are a vector of
1010 arguments, or a vector of vectors of arguments, in the case of
1011 templates with more than one level of parameters.
1013 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1014 then we search for a partial specialization matching ARGS. This
1015 parameter is ignored if TMPL is not a class template.
1017 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1018 result is a NONTYPE_ARGUMENT_PACK. */
1020 static tree
1022 {
1032 /* There should be as many levels of arguments as there are
1033 levels of parameters. */
1040 {
1041 tree class_template;
1042 tree class_specialization;
1044 tree fns;
1047 /* The template arguments actually apply to the containing
1048 class. Find the class specialization with those
1049 arguments. */
1051 class_specialization
1055 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1056 for the specialization. */
1060 /* Iterate through the methods with the indicated name, looking
1061 for the one that has an instance of TMPL. */
1064 {
1067 /* using-declarations can add base methods to the method vec,
1068 and we don't want those here. */
1071 }
1073 }
1074 else
1075 {
1077 spec_entry elt;
1078 htab_t specializations;
1086 else
1094 }
1097 }
1099 /* Like retrieve_specialization, but for local declarations. */
1101 static tree
1103 {
1111 }
1113 /* Returns nonzero iff DECL is a specialization of TMPL. */
1115 int
1117 {
1118 tree t;
1121 {
1127 }
1128 else
1129 {
1138 }
1141 }
1143 /* Returns nonzero iff DECL is a specialization of friend declaration
1144 FRIEND_DECL according to [temp.friend]. */
1146 bool
1148 {
1155 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1156 of a template class, we want to check if DECL is a specialization
1157 if this. */
1161 {
1162 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1165 }
1170 /* There is nothing to do if this is not a template friend. */
1177 /* [temp.friend/6]
1178 A member of a class template may be declared to be a friend of a
1179 non-template class. In this case, the corresponding member of
1180 every specialization of the class template is a friend of the
1181 class granting friendship.
1183 For example, given a template friend declaration
1185 template <class T> friend void A<T>::f();
1187 the member function below is considered a friend
1189 template <> struct A<int> {
1190 void f();
1191 };
1193 For this type of template friend, TEMPLATE_DEPTH below will be
1194 nonzero. To determine if DECL is a friend of FRIEND, we first
1195 check if the enclosing class is a specialization of another. */
1202 {
1203 /* Next, we check the members themselves. In order to handle
1204 a few tricky cases, such as when FRIEND_DECL's are
1206 template <class T> friend void A<T>::g(T t);
1207 template <class T> template <T t> friend void A<T>::h();
1209 and DECL's are
1211 void A<int>::g(int);
1212 template <int> void A<int>::h();
1214 we need to figure out ARGS, the template arguments from
1215 the context of DECL. This is required for template substitution
1216 of `T' in the function parameter of `g' and template parameter
1217 of `h' in the above examples. Here ARGS corresponds to `int'. */
1224 {
1226 {
1229 else
1231 current_depth++;
1232 }
1234 }
1237 {
1239 tree friend_type;
1240 tree decl_type;
1241 tree friend_args_type;
1242 tree decl_args_type;
1244 /* Make sure that both DECL and FRIEND_DECL are templates or
1245 non-templates. */
1251 {
1252 /* If both are templates, check template parameter list. */
1253 tree friend_parms
1258 friend_parms))
1262 }
1263 else
1271 /* Check if return types match. */
1275 /* Check if function parameter types match, ignoring the
1276 `this' parameter. */
1285 }
1286 else
1287 {
1288 /* DECL is a TYPE_DECL */
1292 /* Make sure that both DECL and FRIEND_DECL are templates or
1293 non-templates. */
1294 is_template
1301 {
1302 tree friend_parms;
1303 /* If both are templates, check the name of the two
1304 TEMPLATE_DECL's first because is_friend didn't. */
1309 /* Now check template parameter list. */
1310 friend_parms
1313 return comp_template_parms
1315 friend_parms);
1316 }
1317 else
1320 }
1321 }
1323 }
1325 /* Register the specialization SPEC as a specialization of TMPL with
1326 the indicated ARGS. IS_FRIEND indicates whether the specialization
1327 is actually just a friend declaration. Returns SPEC, or an
1328 equivalent prior declaration, if available.
1330 We also store instantiations of field packs in the hash table, even
1331 though they are not themselves templates, to make lookup easier. */
1333 static tree
1335 hashval_t hash)
1336 {
1337 tree fn;
1339 spec_entry elt;
1347 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1348 register it; we want the corresponding TEMPLATE_DECL instead.
1349 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1350 the more obvious `uses_template_parms (spec)' to avoid problems
1351 with default function arguments. In particular, given
1352 something like this:
1354 template <class T> void f(T t1, T t = T())
1356 the default argument expression is not substituted for in an
1357 instantiation unless and until it is actually needed. */
1361 /* We don't put these specializations in the hash table, but we might
1362 want to give an error about a mismatch. */
1364 else
1365 {
1373 slot =
1377 else
1379 }
1381 /* We can sometimes try to re-register a specialization that we've
1382 already got. In particular, regenerate_decl_from_template calls
1383 duplicate_decls which will update the specialization list. But,
1384 we'll still get called again here anyhow. It's more convenient
1385 to simply allow this than to try to prevent it. */
1389 {
1391 {
1394 {
1396 fn);
1398 }
1399 else
1400 {
1401 tree clone;
1402 /* This situation should occur only if the first
1403 specialization is an implicit instantiation, the
1404 second is an explicit specialization, and the
1405 implicit instantiation has not yet been used. That
1406 situation can occur if we have implicitly
1407 instantiated a member function and then specialized
1408 it later.
1410 We can also wind up here if a friend declaration that
1411 looked like an instantiation turns out to be a
1412 specialization:
1414 template <class T> void foo(T);
1415 class S { friend void foo<>(int) };
1416 template <> void foo(int);
1418 We transform the existing DECL in place so that any
1419 pointers to it become pointers to the updated
1420 declaration.
1422 If there was a definition for the template, but not
1423 for the specialization, we want this to look as if
1424 there were no definition, and vice versa. */
1427 /* The call to duplicate_decls will have applied
1428 [temp.expl.spec]:
1430 An explicit specialization of a function template
1431 is inline only if it is explicitly declared to be,
1432 and independently of whether its function template
1433 is.
1435 to the primary function; now copy the inline bits to
1436 the various clones. */
1438 {
1443 }
1447 }
1448 }
1450 {
1452 /* Dup decl failed, but this is a new definition. Set the
1453 line number so any errors match this new
1454 definition. */
1458 }
1459 }
1463 /* A specialization must be declared in the same namespace as the
1464 template it is specializing. */
1470 {
1478 /* TMPL is a forward declaration of a template function; keep a list
1479 of all specializations in case we need to reassign them to a friend
1480 template later in tsubst_friend_function. */
1483 }
1486 }
1488 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1489 TMPL and ARGS members, ignores SPEC. */
1493 static int
1495 {
1506 }
1508 /* Returns a hash for a template TMPL and template arguments ARGS. */
1510 static hashval_t
1512 {
1515 }
1517 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1518 ignoring SPEC. */
1520 static hashval_t
1522 {
1525 }
1527 /* Recursively calculate a hash value for a template argument ARG, for use
1528 in the hash tables of template specializations. */
1530 hashval_t
1532 {
1544 /* We can get one of these when re-hashing a previous entry in the middle
1545 of substituting into a pack expansion. Just look through it. */
1554 {
1562 {
1567 }
1589 {
1592 {
1595 }
1597 }
1601 {
1604 }
1615 val = iterative_hash_template_arg
1627 val);
1629 val);
1638 /* A lambda can't appear in a template arg, but don't crash on
1639 erroneous input. */
1651 /* Now hash operands as usual. */
1656 }
1659 {
1663 val);
1666 /* Otherwise just compare the types during lookup. */
1675 {
1680 }
1681 }
1684 }
1686 /* Unregister the specialization SPEC as a specialization of TMPL.
1687 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1688 if the SPEC was listed as a specialization of TMPL.
1690 Note that SPEC has been ggc_freed, so we can't look inside it. */
1692 bool
1694 {
1696 spec_entry elt;
1704 {
1709 }
1712 }
1714 /* Like register_specialization, but for local declarations. We are
1715 registering SPEC, an instantiation of TMPL. */
1717 static void
1719 {
1724 }
1726 /* TYPE is a class type. Returns true if TYPE is an explicitly
1727 specialized class. */
1729 bool
1731 {
1735 }
1737 /* Print the list of functions at FNS, going through all the overloads
1738 for each element of the list. Alternatively, FNS can not be a
1739 TREE_LIST, in which case it will be printed together with all the
1740 overloads.
1742 MORE and *STR should respectively be FALSE and NULL when the function
1743 is called from the outside. They are used internally on recursive
1744 calls. print_candidates manages the two parameters and leaves NULL
1745 in *STR when it ends. */
1747 static void
1749 {
1755 {
1759 }
1760 else
1761 {
1764 {
1765 /* Pick the prefix string. */
1767 {
1771 }
1775 }
1778 }
1781 {
1784 }
1785 }
1787 /* Print the list of candidate FNS in an error message. FNS can also
1788 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1790 void
1792 {
1796 }
1798 /* Returns the template (one of the functions given by TEMPLATE_ID)
1799 which can be specialized to match the indicated DECL with the
1800 explicit template args given in TEMPLATE_ID. The DECL may be
1801 NULL_TREE if none is available. In that case, the functions in
1802 TEMPLATE_ID are non-members.
1804 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1805 specialization of a member template.
1807 The TEMPLATE_COUNT is the number of references to qualifying
1808 template classes that appeared in the name of the function. See
1809 check_explicit_specialization for a more accurate description.
1811 TSK indicates what kind of template declaration (if any) is being
1812 declared. TSK_TEMPLATE indicates that the declaration given by
1813 DECL, though a FUNCTION_DECL, has template parameters, and is
1814 therefore a template function.
1816 The template args (those explicitly specified and those deduced)
1817 are output in a newly created vector *TARGS_OUT.
1819 If it is impossible to determine the result, an error message is
1820 issued. The error_mark_node is returned to indicate failure. */
1822 static tree
1824 tree decl,
1828 tmpl_spec_kind tsk)
1829 {
1830 tree fns;
1831 tree targs;
1832 tree explicit_targs;
1834 /* A TREE_LIST of templates of which DECL may be a specialization.
1835 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1836 corresponding TREE_PURPOSE is the set of template arguments that,
1837 when used to instantiate the template, would produce a function
1838 with the signature of DECL. */
1848 /* We shouldn't be specializing a member template of an
1849 unspecialized class template; we already gave an error in
1850 check_specialization_scope, now avoid crashing. */
1853 {
1856 }
1864 /* Check for baselinks. */
1869 {
1872 }
1874 /* Count the number of template headers specified for this
1875 specialization. */
1883 {
1887 {
1888 tree decl_arg_types;
1889 tree fn_arg_types;
1890 tree insttype;
1892 /* In case of explicit specialization, we need to check if
1893 the number of template headers appearing in the specialization
1894 is correct. This is usually done in check_explicit_specialization,
1895 but the check done there cannot be exhaustive when specializing
1896 member functions. Consider the following code:
1898 template <> void A<int>::f(int);
1899 template <> template <> void A<int>::f(int);
1901 Assuming that A<int> is not itself an explicit specialization
1902 already, the first line specializes "f" which is a non-template
1903 member function, whilst the second line specializes "f" which
1904 is a template member function. So both lines are syntactically
1905 correct, and check_explicit_specialization does not reject
1906 them.
1908 Here, we can do better, as we are matching the specialization
1909 against the declarations. We count the number of template
1910 headers, and we check if they match TEMPLATE_COUNT + 1
1911 (TEMPLATE_COUNT is the number of qualifying template classes,
1912 plus there must be another header for the member template
1913 itself).
1915 Notice that if header_count is zero, this is not a
1916 specialization but rather a template instantiation, so there
1917 is no check we can perform here. */
1921 /* Check that the number of template arguments at the
1922 innermost level for DECL is the same as for FN. */
1930 /* DECL might be a specialization of FN. */
1934 /* For a non-static member function, we need to make sure
1935 that the const qualification is the same. Since
1936 get_bindings does not try to merge the "this" parameter,
1937 we must do the comparison explicitly. */
1943 /* Skip the "this" parameter and, for constructors of
1944 classes with virtual bases, the VTT parameter. A
1945 full specialization of a constructor will have a VTT
1946 parameter, but a template never will. */
1947 decl_arg_types
1949 fn_arg_types
1952 /* Function templates cannot be specializations; there are
1953 no partial specializations of functions. Therefore, if
1954 the type of DECL does not match FN, there is no
1955 match. */
1957 {
1961 }
1963 /* See whether this function might be a specialization of this
1964 template. Suppress access control because we might be trying
1965 to make this specialization a friend, and we have already done
1966 access control for the declaration of the specialization. */
1972 /* We cannot deduce template arguments that when used to
1973 specialize TMPL will produce DECL. */
1976 /* Make sure that the deduced arguments actually work. */
1980 fn_arg_types
1985 /* Save this template, and the arguments deduced. */
1987 }
1989 /* FN is an ordinary member function, and we need a
1990 specialization of a member template. */
1991 ;
1993 /* We can get IDENTIFIER_NODEs here in certain erroneous
1994 cases. */
1995 ;
1997 /* This is just an ordinary non-member function. Nothing can
1998 be a specialization of that. */
1999 ;
2001 /* Cannot specialize functions that are created implicitly. */
2002 ;
2003 else
2004 {
2005 tree decl_arg_types;
2007 /* This is an ordinary member function. However, since
2008 we're here, we can assume its enclosing class is a
2009 template class. For example,
2011 template <typename T> struct S { void f(); };
2012 template <> void S<int>::f() {}
2014 Here, S<int>::f is a non-template, but S<int> is a
2015 template class. If FN has the same type as DECL, we
2016 might be in business. */
2019 /* Its enclosing class is an explicit specialization
2020 of a template class. This is not a candidate. */
2025 /* The return types differ. */
2028 /* Adjust the type of DECL in case FN is a static member. */
2035 decl_arg_types))
2036 /* They match! */
2038 }
2039 }
2042 {
2043 /* We have:
2045 [temp.expl.spec]
2047 It is possible for a specialization with a given function
2048 signature to be instantiated from more than one function
2049 template. In such cases, explicit specification of the
2050 template arguments must be used to uniquely identify the
2051 function template specialization being specialized.
2053 Note that here, there's no suggestion that we're supposed to
2054 determine which of the candidate templates is most
2055 specialized. However, we, also have:
2057 [temp.func.order]
2059 Partial ordering of overloaded function template
2060 declarations is used in the following contexts to select
2061 the function template to which a function template
2062 specialization refers:
2064 -- when an explicit specialization refers to a function
2065 template.
2067 So, we do use the partial ordering rules, at least for now.
2068 This extension can only serve to make invalid programs valid,
2069 so it's safe. And, there is strong anecdotal evidence that
2070 the committee intended the partial ordering rules to apply;
2071 the EDG front end has that behavior, and John Spicer claims
2072 that the committee simply forgot to delete the wording in
2073 [temp.expl.spec]. */
2076 {
2079 }
2080 }
2083 {
2091 }
2095 {
2101 }
2103 /* We have one, and exactly one, match. */
2105 {
2108 /* DECL is a re-declaration or partial instantiation of a template
2109 function. */
2112 /* It was a specialization of an ordinary member function in a
2113 template class. */
2115 }
2117 /* It was a specialization of a template. */
2120 {
2125 }
2126 else
2129 }
2131 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2132 but with the default argument values filled in from those in the
2133 TMPL_TYPES. */
2135 static tree
2137 tree tmpl_types)
2138 {
2139 tree new_spec_types;
2147 /* Substitute into the rest of the list. */
2148 new_spec_types =
2152 /* Add the default argument for this parameter. */
2155 new_spec_types);
2156 }
2158 /* DECL is an explicit specialization. Replicate default arguments
2159 from the template it specializes. (That way, code like:
2161 template <class T> void f(T = 3);
2162 template <> void f(double);
2163 void g () { f (); }
2165 works, as required.) An alternative approach would be to look up
2166 the correct default arguments at the call-site, but this approach
2167 is consistent with how implicit instantiations are handled. */
2169 static void
2171 {
2172 tree tmpl;
2173 tree spec_types;
2174 tree tmpl_types;
2175 tree new_spec_types;
2176 tree old_type;
2177 tree new_type;
2178 tree t;
2183 /* See if there's anything we need to do. */
2196 {
2197 /* Remove the this pointer, but remember the object's type for
2198 CV quals. */
2204 {
2205 /* DECL may contain more parameters than TMPL due to the extra
2206 in-charge parameter in constructors and destructors. */
2209 }
2211 {
2214 }
2215 }
2217 /* Compute the merged default arguments. */
2218 new_spec_types =
2221 /* Compute the new FUNCTION_TYPE. */
2223 {
2227 new_spec_types);
2230 /* Put the in-charge parameter back. */
2233 new_spec_types);
2237 new_spec_types);
2238 }
2239 else
2241 new_spec_types);
2247 }
2249 /* Return the number of template headers we expect to see for a definition
2250 or specialization of CTYPE or one of its non-template members. */
2252 int
2254 {
2258 {
2259 /* You're supposed to have one `template <...>' for every
2260 template class, but you don't need one for a full
2261 specialization. For example:
2263 template <class T> struct S{};
2264 template <> struct S<int> { void f(); };
2265 void S<int>::f () {}
2267 is correct; there shouldn't be a `template <>' for the
2268 definition of `S<int>::f'. */
2270 /* If CTYPE does not have template information of any
2271 kind, then it is not a template, nor is it nested
2272 within a template. */
2280 }
2283 }
2285 /* Do a simple sanity check on the template headers that precede the
2286 variable declaration DECL. */
2288 void
2290 {
2297 {
2303 "members of an explicitly specialized class are defined "
2305 }
2306 }
2308 /* Check to see if the function just declared, as indicated in
2309 DECLARATOR, and in DECL, is a specialization of a function
2310 template. We may also discover that the declaration is an explicit
2311 instantiation at this point.
2313 Returns DECL, or an equivalent declaration that should be used
2314 instead if all goes well. Issues an error message if something is
2315 amiss. Returns error_mark_node if the error is not easily
2316 recoverable.
2318 FLAGS is a bitmask consisting of the following flags:
2320 2: The function has a definition.
2321 4: The function is a friend.
2323 The TEMPLATE_COUNT is the number of references to qualifying
2324 template classes that appeared in the name of the function. For
2325 example, in
2327 template <class T> struct S { void f(); };
2328 void S<int>::f();
2330 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2331 classes are not counted in the TEMPLATE_COUNT, so that in
2333 template <class T> struct S {};
2334 template <> struct S<int> { void f(); }
2335 template <> void S<int>::f();
2337 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2338 invalid; there should be no template <>.)
2340 If the function is a specialization, it is marked as such via
2341 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2342 is set up correctly, and it is added to the list of specializations
2343 for that template. */
2345 tree
2347 tree decl,
2350 {
2358 tmpl_spec_kind tsk;
2361 {
2364 else
2366 }
2367 else
2371 {
2374 {
2377 }
2379 {
2381 /* This could be something like:
2383 template <class T> void f(T);
2384 class S { friend void f<>(int); } */
2386 else
2387 {
2388 /* This case handles bogus declarations like template <>
2389 template <class T> void f<int>(); */
2392 declarator);
2394 }
2395 }
2399 /* The error has already been reported in
2400 check_specialization_scope. */
2406 /* Fall through. */
2419 decl);
2422 else
2426 /* Fall through. */
2431 else
2437 {
2438 /* This case handles bogus declarations like template <>
2439 template <class T> void f<int>(); */
2444 else
2446 declarator);
2448 }
2451 /* This is a specialization of a member template, without
2452 specialization the containing class. Something like:
2454 template <class T> struct S {
2455 template <class U> void f (U);
2456 };
2457 template <> template <class U> void S<int>::f(U) {}
2459 That's a specialization -- but of the entire template. */
2465 }
2468 {
2472 {
2476 }
2477 }
2480 {
2484 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2486 {
2487 tree fns;
2492 else
2493 {
2494 /* If there is no class context, the explicit instantiation
2495 must be at namespace scope. */
2498 /* Find the namespace binding, using the declaration
2499 context. */
2503 {
2506 }
2507 else
2508 {
2514 }
2515 }
2518 }
2524 {
2526 /* A specialization in class scope. This is invalid,
2527 but the error will already have been flagged by
2528 check_specialization_scope. */
2530 else
2531 {
2532 /* It's not valid to write an explicit instantiation in
2533 class scope, e.g.:
2535 class C { template void f(); }
2537 This case is caught by the parser. However, on
2538 something like:
2540 template class C { void f(); };
2542 (which is invalid) we can get here. The error will be
2543 issued later. */
2544 ;
2545 }
2548 }
2551 {
2552 /* Find the list of functions in ctype that have the same
2553 name as the declared function. */
2559 {
2564 {
2565 /* From [temp.expl.spec]:
2567 If such an explicit specialization for the member
2568 of a class template names an implicitly-declared
2569 special member function (clause _special_), the
2570 program is ill-formed.
2572 Similar language is found in [temp.explicit]. */
2575 }
2578 }
2581 {
2585 }
2586 else
2587 {
2589 tree ovl;
2591 /* For a type-conversion operator, we cannot do a
2592 name-based lookup. We might be looking for `operator
2593 int' which will be a specialization of `operator T'.
2594 So, we find *all* the conversion operators, and then
2595 select from them. */
2603 {
2605 /* There are no more conversion functions. */
2608 /* Glue all these conversion functions together
2609 with those we already have. */
2612 }
2613 }
2616 {
2619 }
2620 else
2622 }
2624 /* Figure out what exactly is being specialized at this point.
2625 Note that for an explicit instantiation, even one for a
2626 member function, we cannot tell apriori whether the
2627 instantiation is for a member template, or just a member
2628 function of a template class. Even if a member template is
2629 being instantiated, the member template arguments may be
2630 elided if they can be deduced from the rest of the
2631 declaration. */
2634 member_specialization,
2635 template_count,
2636 tsk);
2639 /* We couldn't figure out what this declaration was
2640 specializing. */
2642 else
2643 {
2647 {
2648 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2649 is done by do_decl_instantiation later. */
2655 {
2656 /* If TMPL is not the most general template (for
2657 example, if TMPL is a friend template that is
2658 injected into namespace scope), then there will
2659 be too many levels of TARGS. Remove some of them
2660 here. */
2662 tree new_targs;
2669 }
2672 }
2674 /* If we thought that the DECL was a member function, but it
2675 turns out to be specializing a static member function,
2676 make DECL a static member function as well. */
2681 /* If this is a specialization of a member template of a
2682 template class, we want to return the TEMPLATE_DECL, not
2683 the specialization of it. */
2685 {
2690 {
2691 tree parm;
2695 /* We want to use the argument list specified in the
2696 definition, not in the original declaration. */
2701 }
2704 }
2706 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2709 /* Inherit default function arguments from the template
2710 DECL is specializing. */
2713 /* This specialization has the same protection as the
2714 template it specializes. */
2718 /* 7.1.1-1 [dcl.stc]
2720 A storage-class-specifier shall not be specified in an
2721 explicit specialization...
2723 The parser rejects these, so unless action is taken here,
2724 explicit function specializations will always appear with
2725 global linkage.
2727 The action recommended by the C++ CWG in response to C++
2728 defect report 605 is to make the storage class and linkage
2729 of the explicit specialization match the templated function:
2731 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2732 */
2734 {
2738 /* This specialization has the same linkage and visibility as
2739 the function template it specializes. */
2742 {
2745 }
2748 {
2751 }
2752 }
2754 /* If DECL is a friend declaration, declared using an
2755 unqualified name, the namespace associated with DECL may
2756 have been set incorrectly. For example, in:
2758 template <typename T> void f(T);
2759 namespace N {
2760 struct S { friend void f<int>(int); }
2761 }
2763 we will have set the DECL_CONTEXT for the friend
2764 declaration to N, rather than to the global namespace. */
2769 /* This is not really a declaration of a specialization.
2770 It's just the name of an instantiation. But, it's not
2771 a request for an instantiation, either. */
2774 /* This is indeed a specialization. In case of constructors
2775 and destructors, we need in-charge and not-in-charge
2776 versions in V3 ABI. */
2779 /* Register this specialization so that we can find it
2780 again. */
2782 }
2783 }
2786 }
2788 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2789 parameters. These are represented in the same format used for
2790 DECL_TEMPLATE_PARMS. */
2792 int
2794 {
2795 const_tree p1;
2796 const_tree p2;
2804 {
2816 {
2820 /* If either of the template parameters are invalid, assume
2821 they match for the sake of error recovery. */
2834 }
2835 }
2838 /* One set of parameters has more parameters lists than the
2839 other. */
2843 }
2845 /* Determine whether PARM is a parameter pack. */
2847 bool
2849 {
2850 /* Determine if we have a non-type template parameter pack. */
2857 /* If this is a list of template parameters, we could get a
2858 TYPE_DECL or a TEMPLATE_DECL. */
2862 /* Otherwise it must be a type template parameter. */
2866 }
2868 /* Determine if T is a function parameter pack. */
2870 bool
2872 {
2876 }
2878 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2879 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2881 tree
2883 {
2890 }
2892 /* Return true iff the function parameter PARAM_DECL was expanded
2893 from the function parameter pack PACK. */
2895 bool
2897 {
2902 /* The parameter pack and its pack arguments have the same
2903 DECL_PARM_INDEX. */
2905 }
2907 /* Determine whether ARGS describes a variadic template args list,
2908 i.e., one that is terminated by a template argument pack. */
2910 static bool
2912 {
2914 tree last_parm;
2928 }
2930 /* Generate a new name for the parameter pack name NAME (an
2931 IDENTIFIER_NODE) that incorporates its */
2933 static tree
2935 {
2936 /* Munge the name to include the parameter index. */
2937 #define NUMBUF_LEN 128
2951 }
2953 /* Return true if T is a primary function, class or alias template
2954 instantiation. */
2956 bool
2958 {
2972 }
2974 /* Return true if PARM is a template template parameter. */
2976 bool
2978 {
2980 }
2982 /* Return true iff PARM is a DECL representing a type template
2983 parameter. */
2985 bool
2987 {
2992 }
2994 /* Return the template parameters of T if T is a
2995 primary template instantiation, NULL otherwise. */
2997 tree
2999 {
3004 parms = INNERMOST_TEMPLATE_PARMS
3008 }
3010 /* Return the template parameters of the LEVELth level from the full list
3011 of template parameters PARMS. */
3013 tree
3015 {
3016 tree p;
3027 }
3029 /* Returns the template arguments of T if T is a template instantiation,
3030 NULL otherwise. */
3032 tree
3034 {
3042 }
3044 /* Return the argument pack elements of T if T is a template argument pack,
3045 NULL otherwise. */
3047 tree
3049 {
3055 }
3057 /* Structure used to track the progress of find_parameter_packs_r. */
3058 struct find_parameter_pack_data
3059 {
3060 /* TREE_LIST that will contain all of the parameter packs found by
3061 the traversal. */
3064 /* Set of AST nodes that have been visited by the traversal. */
3066 };
3068 /* Identifies all of the argument packs that occur in a template
3069 argument and appends them to the TREE_LIST inside DATA, which is a
3070 find_parameter_pack_data structure. This is a subroutine of
3071 make_pack_expansion and uses_parameter_packs. */
3072 static tree
3074 {
3080 /* Handle type aliases/typedefs. */
3082 {
3089 }
3091 /* Identify whether this is a parameter pack or not. */
3093 {
3109 {
3110 /* We don't want to walk into the type of a PARM_DECL,
3111 because we don't want to see the type parameter pack. */
3114 }
3117 /* Look through a lambda capture proxy to the field pack. */
3120 {
3126 }
3133 /* Not a parameter pack. */
3135 }
3138 {
3139 /* Add this parameter pack to the list. */
3141 }
3147 /* This switch statement will return immediately if we don't find a
3148 parameter pack. */
3150 {
3155 /* Check the template itself. */
3158 /* Check the template arguments. */
3174 /* Fall through. */
3216 }
3219 }
3221 /* Determines if the expression or type T uses any parameter packs. */
3222 bool
3224 {
3232 }
3234 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3235 representation a base-class initializer into a parameter pack
3236 expansion. If all goes well, the resulting node will be an
3237 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3238 respectively. */
3239 tree
3241 {
3242 tree result;
3251 {
3252 /* The only time we will see a TREE_LIST here is for a base
3253 class initializer. In this case, the TREE_PURPOSE will be a
3254 _TYPE node (representing the base class expansion we're
3255 initializing) and the TREE_VALUE will be a TREE_LIST
3256 containing the initialization arguments.
3258 The resulting expansion looks somewhat different from most
3259 expansions. Rather than returning just one _EXPANSION, we
3260 return a TREE_LIST whose TREE_PURPOSE is a
3261 TYPE_PACK_EXPANSION containing the bases that will be
3262 initialized. The TREE_VALUE will be identical to the
3263 original TREE_VALUE, which is a list of arguments that will
3264 be passed to each base. We do not introduce any new pack
3265 expansion nodes into the TREE_VALUE (although it is possible
3266 that some already exist), because the TREE_PURPOSE and
3267 TREE_VALUE all need to be expanded together with the same
3268 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3269 resulting TREE_PURPOSE will mention the parameter packs in
3270 both the bases and the arguments to the bases. */
3271 tree purpose;
3272 tree value;
3275 /* Determine which parameter packs will be used by the base
3276 class expansion. */
3283 {
3287 }
3290 {
3291 /* Collect the sets of parameter packs used in each of the
3292 initialization arguments. */
3294 {
3295 /* Determine which parameter packs will be expanded in this
3296 argument. */
3299 }
3300 }
3304 /* Create the pack expansion type for the base type. */
3309 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3310 they will rarely be compared to anything. */
3314 }
3319 /* Build the PACK_EXPANSION_* node. */
3320 result = for_types
3325 {
3326 /* Propagate type and const-expression information. */
3329 }
3330 else
3331 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3332 they will rarely be compared to anything. */
3335 /* Determine which parameter packs will be expanded. */
3341 /* Make sure we found some parameter packs. */
3343 {
3346 else
3349 }
3355 }
3357 /* Checks T for any "bare" parameter packs, which have not yet been
3358 expanded, and issues an error if any are found. This operation can
3359 only be done on full expressions or types (e.g., an expression
3360 statement, "if" condition, etc.), because we could have expressions like:
3362 foo(f(g(h(args)))...)
3364 where "args" is a parameter pack. check_for_bare_parameter_packs
3365 should not be called for the subexpressions args, h(args),
3366 g(h(args)), or f(g(h(args))), because we would produce erroneous
3367 error messages.
3369 Returns TRUE and emits an error if there were bare parameter packs,
3370 returns FALSE otherwise. */
3371 bool
3373 {
3389 {
3392 {
3401 else
3406 else
3410 }
3413 }
3416 }
3418 /* Expand any parameter packs that occur in the template arguments in
3419 ARGS. */
3420 tree
3422 {
3428 /* First, determine if we need to expand anything, and the number of
3429 slots we'll need. */
3431 {
3436 {
3440 else
3442 }
3443 else
3444 {
3446 num_result_args++;
3447 }
3448 }
3450 /* If no expansion is necessary, we're done. */
3454 /* Expand arguments. */
3457 non_default_args_count =
3460 {
3463 {
3470 }
3471 else
3472 {
3475 }
3476 }
3480 }
3482 /* Checks if DECL shadows a template parameter.
3484 [temp.local]: A template-parameter shall not be redeclared within its
3485 scope (including nested scopes).
3487 Emits an error and returns TRUE if the DECL shadows a parameter,
3488 returns FALSE otherwise. */
3490 bool
3492 {
3493 tree olddecl;
3495 /* If we're not in a template, we can't possibly shadow a template
3496 parameter. */
3500 /* Figure out what we're shadowing. */
3505 /* If there's no previous binding for this name, we're not shadowing
3506 anything, let alone a template parameter. */
3510 /* If we're not shadowing a template parameter, we're done. Note
3511 that OLDDECL might be an OVERLOAD (or perhaps even an
3512 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3513 node. */
3517 /* We check for decl != olddecl to avoid bogus errors for using a
3518 name inside a class. We check TPFI to avoid duplicate errors for
3519 inline member templates. */
3525 /* Don't complain about the injected class name, as we've already
3526 complained about the class itself. */
3533 }
3535 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3536 ORIG_LEVEL, DECL, and TYPE. */
3538 static tree
3542 tree decl,
3543 tree type)
3544 {
3555 }
3557 /* Find the canonical type parameter for the given template type
3558 parameter. Returns the canonical type parameter, which may be TYPE
3559 if no such parameter existed. */
3561 static tree
3563 {
3564 tree list;
3578 else
3579 {
3584 }
3585 }
3587 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3588 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3589 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3590 new one is created. */
3592 static tree
3594 tsubst_flags_t complain)
3595 {
3600 {
3619 /* Template template parameters need this. */
3624 }
3627 }
3629 /* Process information from new template parameter PARM and append it
3630 to the LIST being built. This new parameter is a non-type
3631 parameter iff IS_NON_TYPE is true. This new parameter is a
3632 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3633 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3634 parameter list PARM belongs to. This is used used to create a
3635 proper canonical type for the type of PARM that is to be created,
3636 iff PARM is a type. If the size is not known, this parameter shall
3637 be set to 0. */
3639 tree
3642 {
3644 tree defval;
3645 tree err_parm_list;
3652 {
3656 {
3660 else
3662 }
3665 }
3666 else
3670 {
3676 {
3680 }
3681 else
3682 {
3683 /* [temp.param]
3685 The top-level cv-qualifiers on the template-parameter are
3686 ignored when determining its type. */
3689 {
3693 }
3696 {
3697 /* This template parameter is not a parameter pack, but it
3698 should be. Complain about "bare" parameter packs. */
3701 /* Recover by calling this a parameter pack. */
3703 }
3704 }
3706 /* A template parameter is not modifiable. */
3715 processing_template_decl,
3720 }
3721 else
3722 {
3723 tree t;
3727 {
3729 /* This is for distinguishing between real templates and template
3730 template parameters */
3734 }
3735 else
3736 {
3738 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3741 }
3748 processing_template_decl,
3752 }
3758 }
3760 /* The end of a template parameter list has been reached. Process the
3761 tree list into a parameter vector, converting each parameter into a more
3762 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3763 as PARM_DECLs. */
3765 tree
3767 {
3772 current_template_parms
3777 {
3781 }
3786 }
3788 /* end_template_decl is called after a template declaration is seen. */
3790 void
3792 {
3798 /* This matches the pushlevel in begin_template_parm_list. */
3803 }
3805 /* Takes a TREE_LIST representing a template parameter and convert it
3806 into an argument suitable to be passed to the type substitution
3807 functions. Note that If the TREE_LIST contains an error_mark
3808 node, the returned argument is error_mark_node. */
3810 static tree
3812 {
3825 {
3829 {
3830 /* Turn this argument into a TYPE_ARGUMENT_PACK
3831 with a single element, which expands T. */
3833 #ifdef ENABLE_CHECKING
3834 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3836 #endif
3841 }
3842 }
3843 else
3844 {
3848 {
3849 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3850 with a single element, which expands T. */
3853 #ifdef ENABLE_CHECKING
3854 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3856 #endif
3863 }
3864 }
3866 }
3868 /* Given a set of template parameters, return them as a set of template
3869 arguments. The template parameters are represented as a TREE_VEC, in
3870 the form documented in cp-tree.h for template arguments. */
3872 static tree
3874 {
3875 tree header;
3880 /* If there is only one level of template parameters, we do not
3881 create a TREE_VEC of TREE_VECs. Instead, we return a single
3882 TREE_VEC containing the arguments. */
3887 {
3895 #ifdef ENABLE_CHECKING
3897 #endif
3901 else
3903 }
3906 /* This can happen for template parms of a template template
3907 parameter, e.g:
3909 template<template<class T, class U> class TT> struct S;
3911 Consider the level of the parms of TT; T and U both have
3912 level 2; TT has no template parm of level 1. So in this case
3913 the first element of full_template_args is NULL_TREE. If we
3914 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3915 of 2. This will make tsubst wrongly consider that T and U
3916 have level 1. Instead, let's create a dummy vector as the
3917 first element of full_template_args so that TMPL_ARGS_DEPTH
3918 returns the correct depth for args. */
3921 }
3923 /* Within the declaration of a template, return the currently active
3924 template parameters as an argument TREE_VEC. */
3926 static tree
3928 {
3930 }
3932 /* Update the declared TYPE by doing any lookups which were thought to be
3933 dependent, but are not now that we know the SCOPE of the declarator. */
3935 tree
3937 {
3948 /* Don't bother building up the args in this case. */
3950 {
3951 /* tsubst in the args corresponding to the template parameters,
3952 including auto if present. Most things will be unchanged, but
3953 make_typename_type and tsubst_qualified_id will resolve
3954 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3957 tree pushed;
3959 {
3963 }
3968 }
3974 {
3977 else
3979 }
3981 }
3983 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3984 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3985 a member template. Used by push_template_decl below. */
3987 static tree
3989 {
3997 }
3999 struct template_parm_data
4000 {
4001 /* The level of the template parameters we are currently
4002 processing. */
4005 /* The index of the specialization argument we are currently
4006 processing. */
4009 /* An array whose size is the number of template parameters. The
4010 elements are nonzero if the parameter has been used in any one
4011 of the arguments processed so far. */
4014 /* An array whose size is the number of template arguments. The
4015 elements are nonzero if the argument makes use of template
4016 parameters of this level. */
4018 };
4020 /* Subroutine of push_template_decl used to see if each template
4021 parameter in a partial specialization is used in the explicit
4022 argument list. If T is of the LEVEL given in DATA (which is
4023 treated as a template_parm_data*), then DATA->PARMS is marked
4024 appropriately. */
4026 static int
4028 {
4034 {
4037 }
4038 else
4039 {
4042 }
4045 {
4048 }
4050 /* Return zero so that for_each_template_parm will continue the
4051 traversal of the tree; we want to mark *every* template parm. */
4053 }
4055 /* Process the partial specialization DECL. */
4057 static tree
4059 {
4065 tree inner_parms;
4066 tree inst;
4079 /* We check that each of the template parameters given in the
4080 partial specialization is used in the argument list to the
4081 specialization. For example:
4083 template <class T> struct S;
4084 template <class T> struct S<T*>;
4086 The second declaration is OK because `T*' uses the template
4087 parameter T, whereas
4089 template <class T> struct S<int>;
4091 is no good. Even trickier is:
4093 template <class T>
4094 struct S1
4095 {
4096 template <class U>
4097 struct S2;
4098 template <class U>
4099 struct S2<T>;
4100 };
4102 The S2<T> declaration is actually invalid; it is a
4103 full-specialization. Of course,
4105 template <class U>
4106 struct S2<T (*)(U)>;
4108 or some such would have been OK. */
4116 {
4121 NULL,
4123 }
4126 {
4127 /* One of the template parms was not used in the
4128 specialization. */
4130 {
4133 }
4136 }
4141 /* [temp.class.spec]
4143 The argument list of the specialization shall not be identical to
4144 the implicit argument list of the primary template. */
4151 /* A partial specialization that replaces multiple parameters of the
4152 primary template with a pack expansion is less specialized for those
4153 parameters. */
4155 {
4157 "primary template because it replaces multiple parameters "
4161 }
4163 /* [temp.class.spec]
4165 A partially specialized non-type argument expression shall not
4166 involve template parameters of the partial specialization except
4167 when the argument expression is a simple identifier.
4169 The type of a template parameter corresponding to a specialized
4170 non-type argument shall not be dependent on a parameter of the
4171 specialization.
4173 Also, we verify that pack expansions only occur at the
4174 end of the argument list. */
4178 {
4185 {
4186 /* Extract the arguments from the argument pack. We'll be
4187 iterating over these in the following loop. */
4190 }
4193 {
4195 /* Get the Jth argument in the parameter pack. */
4199 {
4200 /* Pack expansions must come at the end of the
4201 argument list. */
4204 {
4208 else
4211 }
4212 }
4215 /* We only care about the pattern. */
4221 /* This next line is the `argument expression is not just a
4222 simple identifier' condition and also the `specialized
4223 non-type argument' bit. */
4225 {
4229 arg);
4230 else
4231 {
4232 /* Look at the corresponding template parameter,
4233 marking which template parameters its type depends
4234 upon. */
4238 {
4239 /* We haven't yet initialized TPD2. Do so now. */
4241 /* The number of parameters here is the number in the
4242 main template, which, as checked in the assertion
4243 above, is NARGS. */
4247 }
4249 /* Mark the template parameters. But this time, we're
4250 looking for the template parameters of the main
4251 template, not in the specialization. */
4258 NULL,
4262 {
4263 /* The type depended on some template parameters.
4264 If they are fully specialized in the
4265 specialization, that's OK. */
4274 "type %qT of template argument %qE depends "
4276 "type %qT of template argument %qE depends "
4278 type,
4279 arg);
4280 }
4281 }
4282 }
4283 }
4284 }
4286 /* We should only get here once. */
4304 {
4308 {
4312 "partial specialization of %qT after instantiation "
4314 }
4315 }
4318 }
4320 /* Check that a template declaration's use of default arguments and
4321 parameter packs is not invalid. Here, PARMS are the template
4322 parameters. IS_PRIMARY is true if DECL is the thing declared by
4323 a primary template. IS_PARTIAL is true if DECL is a partial
4324 specialization.
4326 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4327 declaration (but not a definition); 1 indicates a declaration, 2
4328 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4329 emitted for extraneous default arguments.
4331 Returns TRUE if there were no errors found, FALSE otherwise. */
4333 bool
4336 {
4339 tree parm_level;
4342 /* [temp.param]
4344 A default template-argument shall not be specified in a
4345 function template declaration or a function template definition, nor
4346 in the template-parameter-list of the definition of a member of a
4347 class template. */
4350 /* You can't have a function template declaration in a local
4351 scope, nor you can you define a member of a class template in a
4352 local scope. */
4358 /* A lambda doesn't have an explicit declaration; don't complain
4359 about the parms of the enclosing class. */
4366 /* If this is either a friend defined in the scope of the class
4367 or a member function. */
4373 /* And, if it was a member function, it really was defined in
4374 the scope of the class. */
4377 /* We already checked these parameters when the template was
4378 declared, so there's no need to do it again now. This function
4379 was defined in class scope, but we're processing its body now
4380 that the class is complete. */
4383 /* Core issue 226 (C++0x only): the following only applies to class
4384 templates. */
4387 {
4388 /* [temp.param]
4390 If a template-parameter has a default template-argument, all
4391 subsequent template-parameters shall have a default
4392 template-argument supplied. */
4394 {
4401 {
4411 {
4413 /* For better subsequent error-recovery, we indicate that
4414 there should have been a default argument. */
4417 }
4419 && !is_friend_decl
4420 /* Don't complain about an enclosing partial
4421 specialization. */
4426 {
4427 /* A primary class template can only have one
4428 parameter pack, at the end of the template
4429 parameter list. */
4434 else
4442 }
4443 }
4444 }
4445 }
4448 || is_partial
4449 || !is_primary
4451 /* For an ordinary class template, default template arguments are
4452 allowed at the innermost level, e.g.:
4453 template <class T = int>
4454 struct S {};
4455 but, in a partial specialization, they're not allowed even
4456 there, as we have in [temp.class.spec]:
4458 The template parameter list of a specialization shall not
4459 contain default template argument values.
4461 So, for a partial specialization, or for a function template
4462 (in C++98/C++03), we look at all of them. */
4463 ;
4464 else
4465 /* But, for a primary class template that is not a partial
4466 specialization we look at all template parameters except the
4467 innermost ones. */
4470 /* Figure out what error message to issue. */
4483 else
4487 /* If we're inside a class definition, there's no need to
4488 examine the parameters to the class itself. On the one
4489 hand, they will be checked when the class is defined, and,
4490 on the other, default arguments are valid in things like:
4491 template <class T = double>
4492 struct S { template <class U> void f(U); };
4493 Here the default argument for `S' has no bearing on the
4494 declaration of `f'. */
4496 else
4497 /* Check everything. */
4503 {
4510 {
4515 {
4517 {
4524 }
4526 /* Clear out the default argument so that we are not
4527 confused later. */
4529 }
4530 }
4532 /* At this point, if we're still interested in issuing messages,
4533 they must apply to classes surrounding the object declared. */
4537 }
4540 }
4542 /* Worker for push_template_decl_real, called via
4543 for_each_template_parm. DATA is really an int, indicating the
4544 level of the parameters we are interested in. If T is a template
4545 parameter of that level, return nonzero. */
4547 static int
4549 {
4555 else
4558 }
4560 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4561 parameters given by current_template_args, or reuses a
4562 previously existing one, if appropriate. Returns the DECL, or an
4563 equivalent one, if it is replaced via a call to duplicate_decls.
4565 If IS_FRIEND is true, DECL is a friend declaration. */
4567 tree
4569 {
4570 tree tmpl;
4571 tree args;
4572 tree info;
4573 tree ctx;
4577 /* True if the template is a member template, in the sense of
4578 [temp.mem]. */
4584 /* See if this is a partial specialization. */
4593 /* For a friend, we want the context of the friend function, not
4594 the type of which it is a friend. */
4598 /* In the case of a virtual function, we want the class in which
4599 it is defined. */
4601 else
4602 /* Otherwise, if we're currently defining some class, the DECL
4603 is assumed to be a member of the class. */
4612 /* See if this is a primary template. */
4615 /* A friend template that specifies a class context, i.e.
4616 template <typename T> friend void A<T>::f();
4617 is not primary. */
4619 else
4623 {
4628 {
4631 }
4633 {
4635 {
4636 /* [temp.mem]
4638 A destructor shall not be a member template. */
4641 }
4648 {
4649 /* [basic.stc.dynamic.allocation]
4651 An allocation function can be a function
4652 template. ... Template allocation functions shall
4653 have two or more parameters. */
4656 }
4657 }
4663 /* alias-declaration */
4665 else
4666 {
4669 }
4670 }
4672 /* Check to see that the rules regarding the use of default
4673 arguments are not being violated. */
4677 /* Ensure that there are no parameter packs in the type of this
4678 declaration that have not been expanded. */
4680 {
4681 /* Check each of the arguments individually to see if there are
4682 any bare parameter packs. */
4688 {
4691 {
4692 /* This is a PARM_DECL that contains unexpanded parameter
4693 packs. We have already complained about this in the
4694 check_for_bare_parameter_packs call, so just replace
4695 these types with ERROR_MARK_NODE. */
4698 }
4702 }
4704 /* Check for bare parameter packs in the return type and the
4705 exception specifiers. */
4707 /* Errors were already issued, set return type to int
4708 as the frontend doesn't expect error_mark_node as
4709 the return type. */
4713 }
4718 {
4721 }
4734 {
4739 /* If DECL is a TYPE_DECL for a class-template, then there won't
4740 be DECL_LANG_SPECIFIC. The information equivalent to
4741 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4745 {
4746 /* Since a template declaration already existed for this
4747 class-type, we must be redeclaring it here. Make sure
4748 that the redeclaration is valid. */
4750 current_template_parms);
4751 /* We don't need to create a new TEMPLATE_DECL; just use the
4752 one we already had. */
4754 }
4755 else
4756 {
4758 member_template_p);
4763 {
4764 /* A specialization of a member template of a template
4765 class. */
4769 }
4770 }
4771 }
4772 else
4773 {
4779 {
4782 }
4790 {
4791 tree new_tmpl;
4793 /* The declaration is a specialization of a member
4794 template, declared outside the class. Therefore, the
4795 innermost template arguments will be NULL, so we
4796 replace them with the arguments determined by the
4797 earlier call to check_explicit_specialization. */
4800 new_tmpl
4802 member_template_p);
4812 args,
4815 }
4817 /* Make sure the template headers we got make sense. */
4822 {
4825 }
4826 else
4828 {
4833 {
4837 else
4841 /* Avoid crash in import_export_decl. */
4844 }
4849 /* Can happen in erroneous input. */
4851 else
4853 }
4855 /* Check that the parms are used in the appropriate qualifying scopes
4856 in the declarator. */
4860 {
4866 /* Avoid crash in import_export_decl. */
4869 }
4870 }
4875 /* Push template declarations for global functions and types. Note
4876 that we do not try to push a global template friend declared in a
4877 template class; such a thing may well depend on the template
4878 parameters of the class. */
4881 {
4886 /* Hide template friend classes that haven't been declared yet. */
4888 {
4891 }
4892 }
4895 {
4901 {
4904 /* It is a conversion operator. See if the type converted to
4905 depends on innermost template operands. */
4908 depth))
4910 }
4912 /* Give template template parms a DECL_CONTEXT of the template
4913 for which they are a parameter. */
4916 {
4920 }
4921 }
4923 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4924 back to its most general template. If TMPL is a specialization,
4925 ARGS may only have the innermost set of arguments. Add the missing
4926 argument levels if necessary. */
4934 else
4935 {
4940 }
4943 }
4945 tree
4947 {
4949 }
4951 /* FN is an inheriting constructor that inherits from the constructor
4952 template INHERITED; turn FN into a constructor template with a matching
4953 template header. */
4955 tree
4957 {
4958 tree inner_parms
4961 tree parms
4972 }
4974 /* Called when a class template TYPE is redeclared with the indicated
4975 template PARMS, e.g.:
4977 template <class T> struct S;
4978 template <class T> struct S {}; */
4980 bool
4982 {
4983 tree tmpl;
4984 tree tmpl_parms;
4988 {
4991 }
4995 /* The type is nested in some template class. Nothing to worry
4996 about here; there are no new template parameters for the nested
4997 type. */
5001 {
5003 tmpl);
5005 }
5011 {
5021 }
5024 {
5025 tree tmpl_parm;
5026 tree parm;
5027 tree tmpl_default;
5028 tree parm_default;
5042 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5043 TEMPLATE_DECL. */
5053 {
5057 }
5060 {
5061 /* We have in [temp.param]:
5063 A template-parameter may not be given default arguments
5064 by two different declarations in the same scope. */
5069 }
5072 /* Update the previous template parameters (which are the ones
5073 that will really count) with the new default value. */
5076 /* Update the new parameters, too; they'll be used as the
5077 parameters for any members. */
5079 }
5082 }
5084 /* Simplify EXPR if it is a non-dependent expression. Returns the
5085 (possibly simplified) expression. */
5087 tree
5089 {
5093 /* If we're in a template, but EXPR isn't value dependent, simplify
5094 it. We're supposed to treat:
5096 template <typename T> void f(T[1 + 1]);
5097 template <typename T> void f(T[2]);
5099 as two declarations of the same function, for example. */
5103 {
5104 HOST_WIDE_INT saved_processing_template_decl;
5110 complain,
5115 }
5117 }
5119 tree
5121 {
5123 }
5125 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5126 template declaration, or a TYPE_DECL for an alias declaration. */
5128 bool
5130 {
5138 }
5140 /* Return TRUE iff is a specialization of an alias template. */
5142 bool
5144 {
5152 }
5154 /* Return the number of innermost template parameters in TMPL. */
5156 static int
5158 {
5161 }
5163 /* Return either TMPL or another template that it is equivalent to under DR
5164 1286: An alias that just changes the name of a template is equivalent to
5165 the other template. */
5167 static tree
5169 {
5172 {
5175 {
5181 {
5182 /* The alias type is equivalent to the pattern of the
5183 underlying template, so strip the alias. */
5186 }
5187 }
5189 }
5191 }
5193 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5194 must be a function or a pointer-to-function type, as specified
5195 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5196 and check that the resulting function has external linkage. */
5198 static tree
5200 {
5203 linkage_kind linkage;
5215 /* [temp.arg.nontype]/1
5217 A template-argument for a non-type, non-template template-parameter
5218 shall be one of:
5219 [...]
5220 -- the address of an object or function with external [C++11: or
5221 internal] linkage. */
5224 {
5228 else
5231 }
5235 {
5240 else
5245 }
5248 }
5250 /* Subroutine of convert_nontype_argument.
5251 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5252 Emit an error otherwise. */
5254 static bool
5256 tsubst_flags_t complain)
5257 {
5264 {
5268 }
5270 }
5272 /* Returns TRUE iff the address of OP is value-dependent.
5274 14.6.2.4 [temp.dep.temp]:
5275 A non-integral non-type template-argument is dependent if its type is
5276 dependent or it has either of the following forms
5277 qualified-id
5278 & qualified-id
5279 and contains a nested-name-specifier which specifies a class-name that
5280 names a dependent type.
5282 We generalize this to just say that the address of a member of a
5283 dependent class is value-dependent; the above doesn't cover the
5284 address of a static data member named with an unqualified-id. */
5286 static bool
5288 {
5289 /* We could use get_inner_reference here, but there's no need;
5290 this is only relevant for template non-type arguments, which
5291 can only be expressed as &id-expression. */
5293 {
5297 }
5300 }
5302 /* The next set of functions are used for providing helpful explanatory
5303 diagnostics for failed overload resolution. Their messages should be
5304 indented by two spaces for consistency with the messages in
5305 call.c */
5307 static int
5309 {
5311 }
5313 static int
5315 {
5320 }
5322 static int
5324 {
5326 }
5328 static int
5330 {
5336 }
5338 static int
5340 {
5344 }
5346 static int
5348 {
5351 " template parameter %qD is not a parameter pack, but "
5355 }
5357 static int
5359 {
5362 " template argument %qE does not match "
5366 }
5368 static int
5370 {
5374 }
5376 static int
5378 {
5384 }
5386 static int
5388 {
5390 {
5395 else
5397 " deduced conflicting values for non-type parameter "
5399 }
5401 }
5403 static int
5405 {
5408 " variable-sized array type %qT is not "
5410 arg);
5412 }
5414 static int
5416 {
5420 arg);
5422 }
5424 static int
5426 {
5433 }
5435 static int
5437 {
5439 }
5441 static int
5443 {
5445 }
5447 static int
5450 {
5456 }
5458 static int
5461 {
5464 {
5472 }
5474 }
5476 static int
5478 {
5481 " template parameters of a template template argument are "
5484 }
5486 static int
5488 {
5494 }
5496 static int
5498 {
5503 }
5505 static int
5507 {
5511 arg);
5513 }
5515 /* Attempt to convert the non-type template parameter EXPR to the
5516 indicated TYPE. If the conversion is successful, return the
5517 converted value. If the conversion is unsuccessful, return
5518 NULL_TREE if we issued an error message, or error_mark_node if we
5519 did not. We issue error messages for out-and-out bad template
5520 parameters, but not simply because the conversion failed, since we
5521 might be just trying to do argument deduction. Both TYPE and EXPR
5522 must be non-dependent.
5524 The conversion follows the special rules described in
5525 [temp.arg.nontype], and it is much more strict than an implicit
5526 conversion.
5528 This function is called twice for each template argument (see
5529 lookup_template_class for a more accurate description of this
5530 problem). This means that we need to handle expressions which
5531 are not valid in a C++ source, but can be created from the
5532 first call (for instance, casts to perform conversions). These
5533 hacks can go away after we fix the double coercion problem. */
5535 static tree
5537 {
5538 tree expr_type;
5540 /* Detect immediately string literals as invalid non-type argument.
5541 This special-case is not needed for correctness (we would easily
5542 catch this later), but only to provide better diagnostic for this
5543 common user mistake. As suggested by DR 100, we do not mention
5544 linkage issues in the diagnostic as this is not the point. */
5545 /* FIXME we're making this OK. */
5547 {
5553 }
5555 /* Add the ADDR_EXPR now for the benefit of
5556 value_dependent_expression_p. */
5559 {
5563 }
5565 /* If we are in a template, EXPR may be non-dependent, but still
5566 have a syntactic, rather than semantic, form. For example, EXPR
5567 might be a SCOPE_REF, rather than the VAR_DECL to which the
5568 SCOPE_REF refers. Preserving the qualifying scope is necessary
5569 so that access checking can be performed when the template is
5570 instantiated -- but here we need the resolved form so that we can
5571 convert the argument. */
5582 else
5585 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5586 to a non-type argument of "nullptr". */
5590 /* In C++11, integral or enumeration non-type template arguments can be
5591 arbitrary constant expressions. Pointer and pointer to
5592 member arguments can be general constant expressions that evaluate
5593 to a null value, but otherwise still need to be of a specific form. */
5595 {
5597 /* A PTRMEM_CST is already constant, and a valid template
5598 argument for a parameter of pointer to member type, we just want
5599 to leave it in that form rather than lower it to a
5604 {
5609 }
5610 }
5612 /* HACK: Due to double coercion, we can get a
5613 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5614 which is the tree that we built on the first call (see
5615 below when coercing to reference to object or to reference to
5616 function). We just strip everything and get to the arg.
5617 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5618 for examples. */
5620 {
5626 {
5627 /* ??? Maybe we could use convert_from_reference here, but we
5628 would need to relax its constraints because the NOP_EXPR
5629 could actually change the type to something more cv-qualified,
5630 and this is not folded by convert_from_reference. */
5635 && (same_type_ignoring_top_level_qualifiers_p
5638 {
5641 }
5642 }
5643 }
5645 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5646 parameter is a pointer to object, through decay and
5647 qualification conversion. Let's strip everything. */
5649 {
5654 {
5655 /* Skip the ADDR_EXPR only if it is part of the decay for
5656 an array. Otherwise, it is part of the original argument
5657 in the source code. */
5662 }
5663 }
5665 /* [temp.arg.nontype]/5, bullet 1
5667 For a non-type template-parameter of integral or enumeration type,
5668 integral promotions (_conv.prom_) and integral conversions
5669 (_conv.integral_) are applied. */
5671 {
5680 /* Notice that there are constant expressions like '4 % 0' which
5681 do not fold into integer constants. */
5683 {
5685 {
5696 /* else cxx_constant_value complained but gave us
5697 a real constant, so go ahead. */
5699 }
5700 else
5702 }
5704 /* Avoid typedef problems. */
5707 }
5708 /* [temp.arg.nontype]/5, bullet 2
5710 For a non-type template-parameter of type pointer to object,
5711 qualification conversions (_conv.qual_) and the array-to-pointer
5712 conversion (_conv.array_) are applied. */
5714 {
5715 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5717 A template-argument for a non-type, non-template template-parameter
5718 shall be one of: [...]
5720 -- the name of a non-type template-parameter;
5721 -- the address of an object or function with external linkage, [...]
5722 expressed as "& id-expression" where the & is optional if the name
5723 refers to a function or array, or if the corresponding
5724 template-parameter is a reference.
5726 Here, we do not care about functions, as they are invalid anyway
5727 for a parameter of type pointer-to-object. */
5730 /* Non-type template parameters are OK. */
5731 ;
5736 {
5738 {
5740 "because %qD is a variable, not the address of "
5744 }
5746 {
5751 }
5752 /* Other values, like integer constants, might be valid
5753 non-type arguments of some other type. */
5755 }
5756 else
5757 {
5758 tree decl;
5763 {
5768 }
5770 {
5775 }
5777 {
5782 }
5783 }
5792 }
5793 /* [temp.arg.nontype]/5, bullet 3
5795 For a non-type template-parameter of type reference to object, no
5796 conversions apply. The type referred to by the reference may be more
5797 cv-qualified than the (otherwise identical) type of the
5798 template-argument. The template-parameter is bound directly to the
5799 template-argument, which must be an lvalue. */
5801 {
5803 expr_type))
5807 {
5811 }
5814 {
5818 }
5820 /* [temp.arg.nontype]/1
5822 A template-argument for a non-type, non-template template-parameter
5823 shall be one of: [...]
5825 -- the address of an object or function with external linkage. */
5828 {
5831 {
5833 "because a reference variable does not have a constant "
5836 }
5837 }
5840 {
5845 }
5848 {
5853 }
5856 }
5857 /* [temp.arg.nontype]/5, bullet 4
5859 For a non-type template-parameter of type pointer to function, only
5860 the function-to-pointer conversion (_conv.func_) is applied. If the
5861 template-argument represents a set of overloaded functions (or a
5862 pointer to such), the matching function is selected from the set
5863 (_over.over_). */
5865 {
5866 /* If the argument is a template-id, we might not have enough
5867 context information to decay the pointer. */
5869 {
5873 }
5876 /* Null pointer values are OK in C++11. */
5882 }
5883 /* [temp.arg.nontype]/5, bullet 5
5885 For a non-type template-parameter of type reference to function, no
5886 conversions apply. If the template-argument represents a set of
5887 overloaded functions, the matching function is selected from the set
5888 (_over.over_). */
5890 {
5892 {
5897 }
5904 }
5905 /* [temp.arg.nontype]/5, bullet 6
5907 For a non-type template-parameter of type pointer to member function,
5908 no conversions apply. If the template-argument represents a set of
5909 overloaded member functions, the matching member function is selected
5910 from the set (_over.over_). */
5912 {
5917 /* [temp.arg.nontype] bullet 1 says the pointer to member
5918 expression must be a pointer-to-member constant. */
5922 /* There is no way to disable standard conversions in
5923 resolve_address_of_overloaded_function (called by
5924 instantiate_type). It is possible that the call succeeded by
5925 converting &B::I to &D::I (where B is a base of D), so we need
5926 to reject this conversion here.
5928 Actually, even if there was a way to disable standard conversions,
5929 it would still be better to reject them here so that we can
5930 provide a superior diagnostic. */
5932 {
5936 /* If we are just one standard conversion off, explain. */
5941 }
5942 }
5943 /* [temp.arg.nontype]/5, bullet 7
5945 For a non-type template-parameter of type pointer to data member,
5946 qualification conversions (_conv.qual_) are applied. */
5948 {
5949 /* [temp.arg.nontype] bullet 1 says the pointer to member
5950 expression must be a pointer-to-member constant. */
5957 }
5959 {
5961 {
5965 }
5967 }
5968 /* A template non-type parameter must be one of the above. */
5969 else
5972 /* Sanity check: did we actually convert the argument to the
5973 right type? */
5977 }
5979 /* Subroutine of coerce_template_template_parms, which returns 1 if
5980 PARM_PARM and ARG_PARM match using the rule for the template
5981 parameters of template template parameters. Both PARM and ARG are
5982 template parameters; the rest of the arguments are the same as for
5983 coerce_template_template_parms.
5984 */
5985 static int
5987 tree arg,
5988 tsubst_flags_t complain,
5989 tree in_decl,
5990 tree outer_args)
5991 {
6000 {
6002 /* We encounter instantiations of templates like
6003 template <template <template <class> class> class TT>
6004 class C; */
6005 {
6012 }
6013 /* Fall through. */
6018 /* Argument is a parameter pack but parameter is not. */
6023 /* The tsubst call is used to handle cases such as
6025 template <int> class C {};
6026 template <class T, template <T> class TT> class D {};
6027 D<int, C> d;
6029 i.e. the parameter list of TT depends on earlier parameters. */
6031 && !same_type_p
6038 /* Argument is a parameter pack but parameter is not. */
6045 }
6048 }
6051 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6052 template template parameters. Both PARM_PARMS and ARG_PARMS are
6053 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6054 or PARM_DECL.
6056 Consider the example:
6057 template <class T> class A;
6058 template<template <class U> class TT> class B;
6060 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6061 the parameters to A, and OUTER_ARGS contains A. */
6063 static int
6065 tree arg_parms,
6066 tsubst_flags_t complain,
6067 tree in_decl,
6068 tree outer_args)
6069 {
6080 /* Determine whether we have a parameter pack at the end of the
6081 template template parameter's template parameter list. */
6083 {
6090 {
6104 }
6105 }
6111 /* Check all of the template parameters except the parameter pack at
6112 the end (if any). */
6114 {
6123 outer_args))
6126 }
6129 {
6130 /* Check each of the template parameters in the template
6131 argument against the template parameter pack at the end of
6132 the template template parameter. */
6139 {
6146 outer_args))
6148 }
6149 }
6152 }
6154 /* Verifies that the deduced template arguments (in TARGS) for the
6155 template template parameters (in TPARMS) represent valid bindings,
6156 by comparing the template parameter list of each template argument
6157 to the template parameter list of its corresponding template
6158 template parameter, in accordance with DR150. This
6159 routine can only be called after all template arguments have been
6160 deduced. It will return TRUE if all of the template template
6161 parameter bindings are okay, FALSE otherwise. */
6162 bool
6164 {
6168 /* We're dealing with template parms in this process. */
6174 {
6179 {
6184 {
6185 /* Look inside the argument pack. */
6188 }
6191 {
6195 /* Extract the next argument from the argument
6196 pack. */
6200 /* Look at the pattern of the pack expansion. */
6203 /* Extract the template parameters from the template
6204 argument. */
6210 /* Verify that we can coerce the template template
6211 parameters from the template argument to the template
6212 parameter. This requires an exact match. */
6214 && !coerce_template_template_parms
6216 targ_parms,
6217 tf_none,
6218 tparm,
6219 targs))
6220 {
6223 }
6224 }
6225 }
6226 }
6228 out:
6232 }
6234 /* Since type attributes aren't mangled, we need to strip them from
6235 template type arguments. */
6237 static tree
6239 {
6240 tree mv;
6247 {
6252 }
6254 }
6256 /* Convert the indicated template ARG as necessary to match the
6257 indicated template PARM. Returns the converted ARG, or
6258 error_mark_node if the conversion was unsuccessful. Error and
6259 warning messages are issued under control of COMPLAIN. This
6260 conversion is for the Ith parameter in the parameter list. ARGS is
6261 the full set of template arguments deduced so far. */
6263 static tree
6265 tree arg,
6266 tree args,
6267 tsubst_flags_t complain,
6269 tree in_decl)
6270 {
6271 tree orig_arg;
6272 tree val;
6277 {
6278 /* The template argument was the name of some
6279 member function. That's usually
6280 invalid, but static members are OK. In any
6281 case, grab the underlying fields/functions
6282 and issue an error later if required. */
6285 }
6293 /* When determining whether an argument pack expansion is a template,
6294 look at the pattern. */
6298 /* Deal with an injected-class-name used as a template template arg. */
6300 {
6303 {
6313 }
6314 }
6316 is_tmpl_type =
6332 {
6334 {
6338 }
6341 "to refer to a type member of a template parameter, "
6346 typename_type,
6347 complain);
6350 }
6352 {
6354 {
6356 {
6366 else
6368 }
6369 }
6371 }
6373 {
6375 {
6381 else
6383 }
6385 }
6388 {
6390 {
6394 /* The number of argument required is not known yet.
6395 Just accept it for now. */
6397 else
6398 {
6400 tree argparm;
6402 /* Strip alias templates that are equivalent to another
6403 template. */
6409 args))
6410 {
6413 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6414 TEMPLATE_DECL. */
6416 {
6421 }
6422 }
6423 else
6424 {
6426 {
6432 }
6435 }
6436 }
6437 }
6438 else
6440 /* We only form one instance of each template specialization.
6441 Therefore, if we use a non-canonical variant (i.e., a
6442 typedef), any future messages referring to the type will use
6443 the typedef, which is confusing if those future uses do not
6444 themselves also use the typedef. */
6447 }
6448 else
6449 {
6456 {
6459 else
6460 {
6461 /* Not sure if this is reachable, but it doesn't hurt
6462 to be robust. */
6465 }
6466 }
6469 /* We used to call digest_init here. However, digest_init
6470 will report errors, which we don't want when complain
6471 is zero. More importantly, digest_init will try too
6472 hard to convert things: for example, `0' should not be
6473 converted to pointer type at this point according to
6474 the standard. Accepting this is not merely an
6475 extension, since deciding whether or not these
6476 conversions can occur is part of determining which
6477 function template to call, or whether a given explicit
6478 argument specification is valid. */
6480 else
6489 {
6490 /* Strip typedefs from the SCOPE_REF. */
6493 complain);
6496 }
6497 }
6500 }
6502 /* Coerces the remaining template arguments in INNER_ARGS (from
6503 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6504 Returns the coerced argument pack. PARM_IDX is the position of this
6505 parameter in the template parameter list. ARGS is the original
6506 template argument list. */
6507 static tree
6510 tree args,
6511 tree inner_args,
6513 tree new_args,
6515 tree in_decl,
6516 tsubst_flags_t complain)
6517 {
6520 tree packed_args;
6521 tree argument_pack;
6531 {
6532 /* When the template parameter is a non-type template
6533 parameter pack whose type uses parameter packs, we need
6534 to look at each of the template arguments
6535 separately. Build a vector of the types for these
6536 non-type template parameters in PACKED_TYPES. */
6537 tree expansion
6545 /* Check that we have the right number of arguments. */
6549 {
6550 int needed_parms
6555 }
6557 /* If we aren't able to check the actual arguments now
6558 (because they haven't been expanded yet), we can at least
6559 verify that all of the types used for the non-type
6560 template parameter pack are, in fact, valid for non-type
6561 template parameters. */
6564 {
6567 {
6571 }
6572 }
6573 }
6575 /* Convert the remaining arguments, which will be a part of the
6576 parameter pack "parm". */
6578 {
6583 {
6584 /* When we have a vector of types (corresponding to the
6585 non-type template parameter pack that uses parameter
6586 packs in its type, as mention above), and the
6587 argument is not an expansion (which expands to a
6588 currently unknown number of arguments), clone the
6589 parm and give it the next type in PACKED_TYPES. */
6593 }
6596 {
6599 }
6600 else
6603 in_decl);
6607 }
6612 else
6613 {
6618 }
6621 #ifdef ENABLE_CHECKING
6624 #endif
6626 }
6628 /* Returns the number of pack expansions in the template argument vector
6629 ARGS. */
6631 static int
6633 {
6638 {
6642 }
6644 }
6646 /* Convert all template arguments to their appropriate types, and
6647 return a vector containing the innermost resulting template
6648 arguments. If any error occurs, return error_mark_node. Error and
6649 warning messages are issued under control of COMPLAIN.
6651 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6652 for arguments not specified in ARGS. Otherwise, if
6653 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6654 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6655 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6656 ARGS. */
6658 static tree
6660 tree args,
6661 tree in_decl,
6662 tsubst_flags_t complain,
6665 {
6667 tree inner_args;
6668 tree new_args;
6669 tree new_inner_args;
6673 /* When used as a boolean value, indicates whether this is a
6674 variadic template parameter list. Since it's an int, we can also
6675 subtract it from nparms to get the number of non-variadic
6676 parameters. */
6686 /* Determine if there are any parameter packs. */
6688 {
6694 }
6697 /* If there are no parameters that follow a parameter pack, we need to
6698 expand any argument packs so that we can deduce a parameter pack from
6699 some non-packed args followed by an argument pack, as in variadic85.C.
6700 If there are such parameters, we need to leave argument packs intact
6701 so the arguments are assigned properly. This can happen when dealing
6702 with a nested class inside a partial specialization of a class
6703 template, as in variadic92.C, or when deducing a template parameter pack
6704 from a sub-declarator, as in variadic114.C. */
6708 /* Count any pack expansion args. */
6714 && require_all_args
6715 && !variadic_args_p
6716 && (!use_default_args
6719 {
6721 {
6723 {
6727 }
6728 else
6734 }
6737 }
6738 /* We can't pass a pack expansion to a non-pack parameter of an alias
6739 template (DR 1430). */
6741 && variadic_args_p
6743 {
6745 {
6747 {
6753 {
6758 }
6759 }
6761 found:;
6762 }
6764 }
6766 /* We need to evaluate the template arguments, even though this
6767 template-id may be nested within a "sizeof". */
6775 {
6776 tree arg;
6777 tree parm;
6779 /* Get the Ith template parameter. */
6783 {
6786 }
6788 /* Calculate the next argument. */
6791 else
6796 {
6797 /* All remaining arguments will be placed in the
6798 template parameter pack PARM. */
6804 /* Store this argument. */
6806 lost++;
6809 /* We are done with all of the arguments. */
6813 }
6815 {
6817 {
6818 /* We don't know how many args we have yet, just
6819 use the unconverted ones for now. */
6822 }
6823 }
6825 {
6826 /* There must be a default arg in this case. */
6829 /* The position of the first default template argument,
6830 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6831 Record that. */
6834 }
6835 else
6839 {
6842 }
6844 /* This only occurs if there was an error in the template
6845 parameter list itself (which we would already have
6846 reported) that we are trying to recover from, e.g., a class
6847 template with a parameter list such as
6848 template<typename..., typename>. */
6850 else
6856 lost++;
6858 }
6865 #ifdef ENABLE_CHECKING
6869 #endif
6872 }
6874 /* Like coerce_template_parms. If PARMS represents all template
6875 parameters levels, this function returns a vector of vectors
6876 representing all the resulting argument levels. Note that in this
6877 case, only the innermost arguments are coerced because the
6878 outermost ones are supposed to have been coerced already.
6880 Otherwise, if PARMS represents only (the innermost) vector of
6881 parameters, this function returns a vector containing just the
6882 innermost resulting arguments. */
6884 static tree
6886 tree args,
6887 tree in_decl,
6888 tsubst_flags_t complain,
6891 {
6894 tree coerced_args;
6897 {
6899 tree level;
6905 {
6906 tree l;
6910 require_all_args,
6911 use_default_args);
6912 else
6919 }
6920 }
6921 else
6924 require_all_args,
6925 use_default_args);
6927 }
6929 /* Returns 1 if template args OT and NT are equivalent. */
6931 static int
6933 {
6940 /* For member templates */
6949 {
6966 }
6968 {
6969 /* We get here probably because we are in the middle of substituting
6970 into the pattern of a pack expansion. In that case the
6971 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6972 interested in. So we want to use the initial pack argument for
6973 the comparison. */
6978 }
6983 else
6985 }
6987 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6988 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6989 NEWARG_PTR with the offending arguments if they are non-NULL. */
6991 static int
6994 {
7007 {
7012 {
7018 }
7019 }
7021 }
7023 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7024 of template arguments. Returns 0 otherwise. */
7026 int
7028 {
7030 }
7032 static void
7034 {
7044 /* We are called both from instantiate_decl, where we've already had a
7045 tinst_level pushed, and instantiate_template, where we haven't.
7046 Compensate. */
7057 else
7066 }
7069 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7070 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7071 documentation for TEMPLATE_ID_EXPR. */
7073 tree
7075 {
7076 tree type;
7084 {
7087 }
7090 {
7092 unknown_type_node,
7094 arglist);
7096 }
7103 }
7105 /* Within the scope of a template class S<T>, the name S gets bound
7106 (in build_self_reference) to a TYPE_DECL for the class, not a
7107 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7108 or one of its enclosing classes, and that type is a template,
7109 return the associated TEMPLATE_DECL. Otherwise, the original
7110 DECL is returned.
7112 Also handle the case when DECL is a TREE_LIST of ambiguous
7113 injected-class-names from different bases. */
7115 tree
7117 {
7121 /* DR 176: A lookup that finds an injected-class-name (10.2
7122 [class.member.lookup]) can result in an ambiguity in certain cases
7123 (for example, if it is found in more than one base class). If all of
7124 the injected-class-names that are found refer to specializations of
7125 the same class template, and if the name is followed by a
7126 template-argument-list, the reference refers to the class template
7127 itself and not a specialization thereof, and is not ambiguous. */
7129 {
7132 {
7138 }
7141 else
7143 }
7149 }
7151 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7152 parameters, find the desired type.
7154 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7156 IN_DECL, if non-NULL, is the template declaration we are trying to
7157 instantiate.
7159 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7160 the class we are looking up.
7162 Issue error and warning messages under control of COMPLAIN.
7164 If the template class is really a local class in a template
7165 function, then the FUNCTION_CONTEXT is the function in which it is
7166 being instantiated.
7168 ??? Note that this function is currently called *twice* for each
7169 template-id: the first time from the parser, while creating the
7170 incomplete type (finish_template_type), and the second type during the
7171 real instantiation (instantiate_template_class). This is surely something
7172 that we want to avoid. It also causes some problems with argument
7173 coercion (see convert_nontype_argument for more information on this). */
7175 static tree
7178 {
7180 tree t;
7183 spec_entry elt;
7184 hashval_t hash;
7187 {
7191 else
7192 {
7199 }
7202 }
7204 {
7207 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7208 an implicit typename for the second A. Deal with it. */
7213 {
7216 }
7217 }
7220 {
7223 }
7227 {
7231 }
7233 {
7236 }
7238 /* Issue an error message if we didn't find a template. */
7240 {
7244 }
7247 /* Make sure it's a user visible template, if it was named by
7248 the user. */
7251 {
7253 {
7257 }
7259 }
7263 /* An alias that just changes the name of a template is equivalent to the
7264 other template, so if any of the arguments are pack expansions, strip
7265 the alias to avoid problems with a pack expansion passed to a non-pack
7266 alias template parameter (DR 1430). */
7271 {
7272 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7273 template arguments */
7275 tree parm;
7276 tree arglist2;
7277 tree outer;
7281 /* Consider an example where a template template parameter declared as
7283 template <class T, class U = std::allocator<T> > class TT
7285 The template parameter level of T and U are one level larger than
7286 of TT. To proper process the default argument of U, say when an
7287 instantiation `TT<int>' is seen, we need to build the full
7288 arguments containing {int} as the innermost level. Outer levels,
7289 available when not appearing as default template argument, can be
7290 obtained from the arguments of the enclosing template.
7292 Suppose that TT is later substituted with std::vector. The above
7293 instantiation is `TT<int, std::allocator<T> >' with TT at
7294 level 1, and T at level 2, while the template arguments at level 1
7295 becomes {std::vector} and the inner level 2 is {int}. */
7301 /* This is an argument of the current template, so we haven't set
7302 DECL_CONTEXT yet. */
7309 complain,
7319 }
7320 else
7321 {
7323 tree gen_tmpl;
7324 tree type_decl;
7332 /* An error occurred while building the template TEMPL, and a
7333 diagnostic has most certainly been emitted for that
7334 already. Let's propagate that error. */
7343 {
7344 /* We've been given an incomplete set of template arguments.
7345 For example, given:
7347 template <class T> struct S1 {
7348 template <class U> struct S2 {};
7349 template <class U> struct S2<U*> {};
7350 };
7352 we will be called with an ARGLIST of `U*', but the
7353 TEMPLATE will be `template <class T> template
7354 <class U> struct S1<T>::S2'. We must fill in the missing
7355 arguments. */
7356 arglist
7358 arglist);
7360 }
7362 /* Now we should have enough arguments. */
7365 /* From here on, we're only interested in the most general
7366 template. */
7368 /* Calculate the BOUND_ARGS. These will be the args that are
7369 actually tsubst'd into the definition to create the
7370 instantiation. */
7372 {
7373 /* We have multiple levels of arguments to coerce, at once. */
7383 {
7384 tree a;
7388 complain,
7391 else
7392 /* Outer levels should have already been coerced. */
7395 /* Don't process further if one of the levels fails. */
7397 {
7398 /* Restore the ARGLIST to its full size. */
7401 }
7405 /* We temporarily reduce the length of the ARGLIST so
7406 that coerce_template_parms will see only the arguments
7407 corresponding to the template parameters it is
7408 examining. */
7410 }
7412 /* Restore the ARGLIST to its full size. */
7416 }
7417 else
7418 arglist
7421 gen_tmpl,
7422 complain,
7427 /* We were unable to bind the arguments. */
7430 /* In the scope of a template class, explicit references to the
7431 template class refer to the type of the template, not any
7432 instantiation of it. For example, in:
7434 template <class T> class C { void f(C<T>); }
7436 the `C<T>' is just the same as `C'. Outside of the
7437 class, however, such a reference is an instantiation. */
7441 /* comp_template_args is expensive, check it last. */
7443 arglist))
7446 /* If we already have this specialization, return it. */
7458 /* If the deduced arguments are invalid, then the binding
7459 failed. */
7463 complain))
7470 {
7475 }
7485 /* Create the type. */
7487 {
7488 /* The user referred to a specialization of an alias
7489 template represented by GEN_TMPL.
7491 [temp.alias]/2 says:
7493 When a template-id refers to the specialization of an
7494 alias template, it is equivalent to the associated
7495 type obtained by substitution of its
7496 template-arguments for the template-parameters in the
7497 type-id of the alias template. */
7500 /* Note that the call above (by indirectly calling
7501 register_specialization in tsubst_decl) registers the
7502 TYPE_DECL representing the specialization of the alias
7503 template. So next time someone substitutes ARGLIST for
7504 the template parms into the alias template (GEN_TMPL),
7505 she'll get that TYPE_DECL back. */
7509 }
7511 {
7513 {
7522 }
7523 else
7524 {
7525 /* We don't want to call start_enum for this type, since
7526 the values for the enumeration constants may involve
7527 template parameters. And, no one should be interested
7528 in the enumeration constants for such a type. */
7531 }
7535 }
7537 {
7544 /* A local class. Make sure the decl gets registered properly. */
7549 /* This instantiation is another name for the primary
7550 template type. Set the TYPE_CANONICAL field
7551 appropriately. */
7554 /* Some of the template arguments require structural
7555 equality testing, so this template class requires
7556 structural equality testing. */
7558 }
7559 else
7562 /* If we called start_enum or pushtag above, this information
7563 will already be set up. */
7565 {
7572 }
7573 else
7577 {
7583 {
7586 }
7587 }
7589 /* Let's consider the explicit specialization of a member
7590 of a class template specialization that is implicitely instantiated,
7591 e.g.:
7592 template<class T>
7593 struct S
7594 {
7595 template<class U> struct M {}; //#0
7596 };
7598 template<>
7599 template<>
7600 struct S<int>::M<char> //#1
7601 {
7602 int i;
7603 };
7604 [temp.expl.spec]/4 says this is valid.
7606 In this case, when we write:
7607 S<int>::M<char> m;
7609 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7610 the one of #0.
7612 When we encounter #1, we want to store the partial instantiation
7613 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7615 For all cases other than this "explicit specialization of member of a
7616 class template", we just want to store the most general template into
7617 the CLASSTYPE_TI_TEMPLATE of M.
7619 This case of "explicit specialization of member of a class template"
7620 only happens when:
7621 1/ the enclosing class is an instantiation of, and therefore not
7622 the same as, the context of the most general template, and
7623 2/ we aren't looking at the partial instantiation itself, i.e.
7624 the innermost arguments are not the same as the innermost parms of
7625 the most general template.
7627 So it's only when 1/ and 2/ happens that we want to use the partial
7628 instantiation of the member template in lieu of its most general
7629 template. */
7633 /* the enclosing class must be an instantiation... */
7636 {
7637 tree partial_inst_args;
7640 partial_inst_args =
7646 use_partial_inst_tmpl =
7647 /*...and we must not be looking at the partial instantiation
7648 itself. */
7650 partial_inst_args);
7651 }
7654 /* This case is easy; there are no member templates involved. */
7656 else
7657 {
7658 /* This is a full instantiation of a member template. Find
7659 the partial instantiation of which this is an instance. */
7661 /* Temporarily reduce by one the number of levels in the ARGLIST
7662 so as to avoid comparing the last set of arguments. */
7666 /* FOUND is either a proper class type, or an alias
7667 template specialization. In the later case, it's a
7668 TYPE_DECL, resulting from the substituting of arguments
7669 for parameters in the TYPE_DECL of the alias template
7670 done earlier. So be careful while getting the template
7671 of FOUND. */
7675 }
7686 /* Note this use of the partial instantiation so we can check it
7687 later in maybe_process_partial_specialization. */
7694 /* Now that the type has been registered on the instantiations
7695 list, we set up the enumerators. Because the enumeration
7696 constants may involve the enumeration type itself, we make
7697 sure to register the type first, and then create the
7698 constants. That way, doing tsubst_expr for the enumeration
7699 constants won't result in recursive calls here; we'll find
7700 the instantiation and exit above. */
7704 /* If the type makes use of template parameters, the
7705 code that generates debugging information will crash. */
7708 /* Possibly limit visibility based on template args. */
7713 }
7714 }
7716 /* Wrapper for lookup_template_class_1. */
7718 tree
7721 {
7722 tree ret;
7728 }
7729 \f
7730 struct pair_fn_data
7731 {
7732 tree_fn_t fn;
7734 /* True when we should also visit template parameters that occur in
7735 non-deduced contexts. */
7738 };
7740 /* Called from for_each_template_parm via walk_tree. */
7742 static tree
7744 {
7757 {
7761 /* Fall through. */
7784 /* Since we're not going to walk subtrees, we have to do this
7785 explicitly here. */
7789 /* Fall through. */
7792 /* Check the return type. */
7797 /* Check the parameter types. Since default arguments are not
7798 instantiated until they are needed, the TYPE_ARG_TYPES may
7799 contain expressions that involve template parameters. But,
7800 no-one should be looking at them yet. And, once they're
7801 instantiated, they don't contain template parameters, so
7802 there's no point in looking at them then, either. */
7803 {
7804 tree parm;
7811 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7812 want walk_tree walking into them itself. */
7814 }
7832 /* Fall through. */
7848 /* Record template parameters such as `T' inside `TT<T>'. */
7852 /* Fall through. */
7864 /* A template template parameter is encountered. */
7870 /* Already substituted template template parameter */
7893 /* If there's no type, then this thing must be some expression
7894 involving template parameters. */
7916 }
7918 /* We didn't find any template parameters we liked. */
7920 }
7922 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7923 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7924 call FN with the parameter and the DATA.
7925 If FN returns nonzero, the iteration is terminated, and
7926 for_each_template_parm returns 1. Otherwise, the iteration
7927 continues. If FN never returns a nonzero value, the value
7928 returned by for_each_template_parm is 0. If FN is NULL, it is
7929 considered to be the function which always returns 1.
7931 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7932 parameters that occur in non-deduced contexts. When false, only
7933 visits those template parameters that can be deduced. */
7935 static int
7939 {
7943 /* Set up. */
7948 /* Walk the tree. (Conceptually, we would like to walk without
7949 duplicates, but for_each_template_parm_r recursively calls
7950 for_each_template_parm, so we would need to reorganize a fair
7951 bit to use walk_tree_without_duplicates, so we keep our own
7952 visited list.) */
7955 else
7958 for_each_template_parm_r,
7962 /* Clean up. */
7964 {
7967 }
7970 }
7972 /* Returns true if T depends on any template parameter. */
7974 int
7976 {
8003 else
8004 {
8007 }
8012 }
8014 /* Returns true iff current_function_decl is an incompletely instantiated
8015 template. Useful instead of processing_template_decl because the latter
8016 is set to 0 during fold_non_dependent_expr. */
8018 bool
8020 {
8029 }
8031 /* Returns true if T depends on any template parameter with level LEVEL. */
8033 int
8035 {
8038 }
8040 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8041 ill-formed translation unit, i.e. a variable or function that isn't
8042 usable in a constant expression. */
8046 {
8050 }
8052 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8053 neglectable and instantiated from within an erroneous instantiation. */
8055 static bool
8057 {
8068 }
8076 /* We're starting to instantiate D; record the template instantiation context
8077 for diagnostics and to restore it later. */
8079 int
8081 {
8085 {
8091 else
8099 }
8101 /* If the current instantiation caused problems, don't let it instantiate
8102 anything else. Do allow deduction substitution and decls usable in
8103 constant expressions. */
8120 }
8122 /* We're done instantiating this template; return to the instantiation
8123 context. */
8125 void
8127 {
8128 /* Restore the filename and line number stashed away when we started
8129 this instantiation. */
8133 }
8135 /* We're instantiating a deferred template; restore the template
8136 instantiation context in which the instantiation was requested, which
8137 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8139 static tree
8141 {
8153 }
8155 /* Returns the TINST_LEVEL which gives the original instantiation
8156 context. */
8160 {
8166 }
8168 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8169 vector of template arguments, as for tsubst.
8171 Returns an appropriate tsubst'd friend declaration. */
8173 static tree
8175 {
8176 tree new_friend;
8181 /* This was a friend declared with an explicit template
8182 argument list, e.g.:
8184 friend void f<>(T);
8186 to indicate that f was a template instantiation, not a new
8187 function declaration. Now, we have to figure out what
8188 instantiation of what template. */
8189 {
8191 tree new_args;
8192 tree tmpl;
8195 /* Friend functions are looked up in the containing namespace scope.
8196 We must enter that scope, to avoid finding member functions of the
8197 current class with same name. */
8212 tsk_none);
8214 }
8218 /* The NEW_FRIEND will look like an instantiation, to the
8219 compiler, but is not an instantiation from the point of view of
8220 the language. For example, we might have had:
8222 template <class T> struct S {
8223 template <class U> friend void f(T, U);
8224 };
8226 Then, in S<int>, template <class U> void f(int, U) is not an
8227 instantiation of anything. */
8233 {
8237 }
8239 /* The mangled name for the NEW_FRIEND is incorrect. The function
8240 is not a template instantiation and should not be mangled like
8241 one. Therefore, we forget the mangling here; we'll recompute it
8242 later if we need it. */
8244 {
8247 }
8250 {
8251 tree old_decl;
8252 tree new_friend_template_info;
8253 tree new_friend_result_template_info;
8254 tree ns;
8257 /* We must save some information from NEW_FRIEND before calling
8258 duplicate decls since that function will free NEW_FRIEND if
8259 possible. */
8261 new_friend_is_defn =
8266 {
8267 /* This declaration is a `primary' template. */
8270 new_friend_result_template_info
8272 }
8273 else
8276 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8280 /* Inside pushdecl_namespace_level, we will push into the
8281 current namespace. However, the friend function should go
8282 into the namespace of the template. */
8292 {
8293 /* This new friend declaration matched an existing
8294 declaration. For example, given:
8296 template <class T> void f(T);
8297 template <class U> class C {
8298 template <class T> friend void f(T) {}
8299 };
8301 the friend declaration actually provides the definition
8302 of `f', once C has been instantiated for some type. So,
8303 old_decl will be the out-of-class template declaration,
8304 while new_friend is the in-class definition.
8306 But, if `f' was called before this point, the
8307 instantiation of `f' will have DECL_TI_ARGS corresponding
8308 to `T' but not to `U', references to which might appear
8309 in the definition of `f'. Previously, the most general
8310 template for an instantiation of `f' was the out-of-class
8311 version; now it is the in-class version. Therefore, we
8312 run through all specialization of `f', adding to their
8313 DECL_TI_ARGS appropriately. In particular, they need a
8314 new set of outer arguments, corresponding to the
8315 arguments for this class instantiation.
8317 The same situation can arise with something like this:
8319 friend void f(int);
8320 template <class T> class C {
8321 friend void f(T) {}
8322 };
8324 when `C<int>' is instantiated. Now, `f(int)' is defined
8325 in the class. */
8328 /* On the other hand, if the in-class declaration does
8329 *not* provide a definition, then we don't want to alter
8330 existing definitions. We can just leave everything
8331 alone. */
8332 ;
8333 else
8334 {
8338 /* Overwrite whatever template info was there before, if
8339 any, with the new template information pertaining to
8340 the declaration. */
8344 {
8345 /* We should have called reregister_specialization in
8346 duplicate_decls. */
8351 /* Instantiate it if the global has already been used. */
8355 }
8356 else
8357 {
8358 tree t;
8360 /* Indicate that the old function template is a partial
8361 instantiation. */
8369 /* Reassign any specializations already in the hash table
8370 to the new more general template, and add the
8371 additional template args. */
8375 {
8377 spec_entry elt;
8389 register_specialization
8392 }
8394 }
8395 }
8397 /* The information from NEW_FRIEND has been merged into OLD_DECL
8398 by duplicate_decls. */
8400 }
8401 }
8402 else
8403 {
8407 /* In the code
8408 template <class T> class C {
8409 template <class U> friend void C1<U>::f (); // case 1
8410 friend void C2<T>::f (); // case 2
8411 };
8412 we only need to make sure CONTEXT is a complete type for
8413 case 2. To distinguish between the two cases, we note that
8414 CONTEXT of case 1 remains dependent type after tsubst while
8415 this isn't true for case 2. */
8425 {
8427 /* do_friend adds the TEMPLATE_DECL for any member friend
8428 template even if it isn't a member template, i.e.
8429 template <class T> friend A<T>::f();
8430 Look through it in that case. */
8434 /* Check to see that the declaration is really present, and,
8435 possibly obtain an improved declaration. */
8440 }
8441 }
8444 }
8446 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8447 template arguments, as for tsubst.
8449 Returns an appropriate tsubst'd friend type or error_mark_node on
8450 failure. */
8452 static tree
8454 {
8455 tree friend_type;
8456 tree tmpl;
8457 tree context;
8460 {
8463 }
8468 {
8471 else
8473 }
8475 /* Look for a class template declaration. We look for hidden names
8476 because two friend declarations of the same template are the
8477 same. For example, in:
8479 struct A {
8480 template <typename> friend class F;
8481 };
8482 template <typename> struct B {
8483 template <typename> friend class F;
8484 };
8486 both F templates are the same. */
8490 /* But, if we don't find one, it might be because we're in a
8491 situation like this:
8493 template <class T>
8494 struct S {
8495 template <class U>
8496 friend struct S;
8497 };
8499 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8500 for `S<int>', not the TEMPLATE_DECL. */
8502 {
8505 }
8508 {
8509 /* The friend template has already been declared. Just
8510 check to see that the declarations match, and install any new
8511 default parameters. We must tsubst the default parameters,
8512 of course. We only need the innermost template parameters
8513 because that is all that redeclare_class_template will look
8514 at. */
8517 {
8518 tree parms;
8519 location_t saved_input_location;
8528 }
8531 }
8532 else
8533 {
8534 /* The friend template has not already been declared. In this
8535 case, the instantiation of the template class will cause the
8536 injection of this template into the global scope. */
8541 /* The new TMPL is not an instantiation of anything, so we
8542 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8543 the new type because that is supposed to be the corresponding
8544 template decl, i.e., TMPL. */
8551 /* Inject this template into the global scope. */
8553 }
8556 {
8559 else
8561 }
8564 }
8566 /* Returns zero if TYPE cannot be completed later due to circularity.
8567 Otherwise returns one. */
8569 static int
8571 {
8581 else
8583 }
8587 /* Apply any attributes which had to be deferred until instantiation
8588 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8589 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8591 static void
8594 {
8596 tree t;
8601 {
8605 }
8608 {
8612 }
8613 else
8617 {
8622 {
8625 {
8632 {
8639 clauses
8643 else
8645 }
8646 /* If the first attribute argument is an identifier, don't
8647 pass it through tsubst. Attributes like mode, format,
8648 cleanup and several target specific attributes expect it
8649 unmodified. */
8652 {
8653 tree chain
8655 in_decl,
8660 chain);
8661 }
8662 else
8668 }
8669 else
8671 }
8674 }
8675 }
8677 /* Perform (or defer) access check for typedefs that were referenced
8678 from within the template TMPL code.
8679 This is a subroutine of instantiate_decl and instantiate_class_template.
8680 TMPL is the template to consider and TARGS is the list of arguments of
8681 that template. */
8683 static void
8685 {
8686 location_t saved_location;
8697 {
8709 /* Make access check error messages point to the location
8710 of the use of the typedef. */
8714 tf_warning_or_error);
8715 }
8717 }
8719 static tree
8721 {
8723 tree typedecl;
8724 tree pbinfo;
8725 tree base_list;
8727 tree fn_context;
8736 /* Figure out which template is being instantiated. */
8740 /* Determine what specialization of the original template to
8741 instantiate. */
8744 {
8747 }
8749 {
8750 /* This TYPE is actually an instantiation of a partial
8751 specialization. We replace the innermost set of ARGS with
8752 the arguments appropriate for substitution. For example,
8753 given:
8755 template <class T> struct S {};
8756 template <class T> struct S<T*> {};
8758 and supposing that we are instantiating S<int*>, ARGS will
8759 presently be {int*} -- but we need {int}. */
8762 }
8763 else
8764 {
8767 }
8769 /* If the template we're instantiating is incomplete, then clearly
8770 there's nothing we can do. */
8774 /* If we've recursively instantiated too many templates, stop. */
8778 /* Now we're really doing the instantiation. Mark the type as in
8779 the process of being defined. */
8782 /* We may be in the middle of deferred access check. Disable
8783 it now. */
8789 /* Use #pragma pack from the template context. */
8795 /* Set the input location to the most specialized template definition.
8796 This is needed if tsubsting causes an error. */
8808 {
8811 /* Adjust visibility for template arguments. */
8813 }
8819 /* We should never instantiate a nested class before its enclosing
8820 class; we need to look up the nested class by name before we can
8821 instantiate it, and that lookup should instantiate the enclosing
8822 class. */
8828 {
8829 tree pbase_binfo;
8830 tree pushed_scope;
8833 /* We must enter the scope containing the type, as that is where
8834 the accessibility of types named in dependent bases are
8835 looked up from. */
8838 /* Substitute into each of the bases to determine the actual
8839 basetypes. */
8841 {
8842 tree base;
8848 {
8849 expanded_bases =
8856 }
8859 {
8861 /* Extract the already-expanded base class. */
8863 else
8864 /* Substitute to figure out the base class. */
8866 NULL_TREE);
8874 }
8875 }
8877 /* The list is now in reverse order; correct that. */
8882 }
8883 /* Now call xref_basetypes to set up all the base-class
8884 information. */
8892 /* Now that our base classes are set up, enter the scope of the
8893 class, so that name lookups into base classes, etc. will work
8894 correctly. This is precisely analogous to what we do in
8895 begin_class_definition when defining an ordinary non-template
8896 class, except we also need to push the enclosing classes. */
8899 /* Now members are processed in the order of declaration. */
8902 {
8906 {
8908 {
8909 /* Build new CLASSTYPE_NESTED_UTDS. */
8911 tree newtag;
8917 /* If the member is a class template, then -- even after
8918 substitution -- there may be dependent types in the
8919 template argument list for the class. We increment
8920 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8921 that function will assume that no types are dependent
8922 when outside of a template. */
8932 {
8936 /* Unfortunately, lookup_template_class sets
8937 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8938 instantiation (i.e., for the type of a member
8939 template class nested within a template class.)
8940 This behavior is required for
8941 maybe_process_partial_specialization to work
8942 correctly, but is not accurate in this case;
8943 the TAG is not an instantiation of anything.
8944 (The corresponding TEMPLATE_DECL is an
8945 instantiation, but the TYPE is not.) */
8948 /* Now, we call pushtag to put this NEWTAG into the scope of
8949 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8950 pushtag calling push_template_decl. We don't have to do
8951 this for enums because it will already have been done in
8952 tsubst_enum. */
8956 }
8957 }
8959 {
8960 /* Build new TYPE_METHODS. */
8961 tree r;
8970 /* Instantiate members marked with attribute used. */
8976 }
8977 else
8978 {
8979 /* Build new TYPE_FIELDS. */
8981 {
8982 tree condition;
8985 condition =
8995 }
8997 {
8998 tree r;
9002 /* The file and line for this declaration, to
9003 assist in error message reporting. Since we
9004 called push_tinst_level above, we don't need to
9005 restore these. */
9015 {
9016 /* A capture pack became multiple fields. */
9019 }
9022 {
9026 {
9027 /* In [temp.inst]:
9029 [t]he initialization (and any associated
9030 side-effects) of a static data member does
9031 not occur unless the static data member is
9032 itself used in a way that requires the
9033 definition of the static data member to
9034 exist.
9036 Therefore, we do not substitute into the
9037 initialized for the static data member here. */
9038 finish_static_data_member_decl
9044 /* Instantiate members marked with attribute used. */
9047 }
9049 {
9050 /* Determine whether R has a valid type and can be
9051 completed later. If R is invalid, then its type
9052 is replaced by error_mark_node. */
9058 {
9061 }
9062 }
9064 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9065 such a thing will already have been added to the field
9066 list by tsubst_enum in finish_member_declaration in the
9067 CLASSTYPE_NESTED_UTDS case above. */
9071 {
9074 }
9075 }
9076 }
9077 }
9078 }
9079 else
9080 {
9083 {
9084 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9090 {
9091 /* template <class T> friend class C; */
9094 }
9096 {
9097 /* template <class T> friend class C::D; */
9103 }
9106 {
9107 /* This could be either
9109 friend class T::C;
9111 when dependent_type_p is false or
9113 template <class U> friend class T::C;
9115 otherwise. */
9118 /* Bump processing_template_decl for correct
9119 dependent_type_p calculation. */
9124 }
9127 {
9128 /* friend class C;
9130 where C hasn't been declared yet. Let's lookup name
9131 from namespace scope directly, bypassing any name that
9132 come from dependent base class. */
9135 /* The call to xref_tag_from_type does injection for friend
9136 classes. */
9138 friend_type =
9142 }
9144 /* friend class C<T>; */
9147 /* Otherwise it's
9149 friend class C;
9151 where C is already declared or
9153 friend class C<int>;
9155 We don't have to do anything in these cases. */
9158 /* Trick make_friend_class into realizing that the friend
9159 we're adding is a template, not an ordinary class. It's
9160 important that we use make_friend_class since it will
9161 perform some error-checking and output cross-reference
9162 information. */
9170 }
9171 else
9172 {
9173 /* Build new DECL_FRIENDLIST. */
9174 tree r;
9176 /* The file and line for this declaration, to
9177 assist in error message reporting. Since we
9178 called push_tinst_level above, we don't need to
9179 restore these. */
9183 {
9186 }
9191 {
9194 }
9195 }
9196 }
9197 }
9200 {
9203 {
9208 /* We need to instantiate the capture list from the template
9209 after we've instantiated the closure members, but before we
9210 consider adding the conversion op. Also keep any captures
9211 that may have been added during instantiation of the op(). */
9213 tree tmpl_cap
9222 }
9223 else
9225 }
9227 /* Set the file and line number information to whatever is given for
9228 the class itself. This puts error messages involving generated
9229 implicit functions at a predictable point, and the same point
9230 that would be used for non-template classes. */
9237 /* We don't instantiate default arguments for member functions. 14.7.1:
9239 The implicit instantiation of a class template specialization causes
9240 the implicit instantiation of the declarations, but not of the
9241 definitions or default arguments, of the class member functions,
9242 member classes, static data members and member templates.... */
9244 /* Some typedefs referenced from within the template code need to be access
9245 checked at template instantiation time, i.e now. These types were
9246 added to the template at parsing time. Let's get those and perform
9247 the access checks then. */
9257 /* The vtable for a template class can be emitted in any translation
9258 unit in which the class is instantiated. When there is no key
9259 method, however, finish_struct_1 will already have added TYPE to
9260 the keyed_classes list. */
9265 }
9267 /* Wrapper for instantiate_class_template_1. */
9269 tree
9271 {
9272 tree ret;
9277 }
9279 static tree
9281 {
9282 tree r;
9288 else
9289 {
9296 }
9298 }
9300 /* Given a function parameter pack TMPL_PARM and some function parameters
9301 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9302 and set *SPEC_P to point at the next point in the list. */
9304 static tree
9306 {
9307 /* Collect all of the extra "packed" parameters into an
9308 argument pack. */
9309 tree parmvec;
9310 tree parmtypevec;
9321 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9326 {
9329 }
9331 /* Build the argument packs. */
9338 }
9340 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9341 NONTYPE_ARGUMENT_PACK. */
9343 static tree
9345 {
9347 }
9349 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9350 pack expansion. */
9352 static bool
9354 {
9359 }
9362 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9364 static tree
9366 {
9373 }
9375 /* This is a subroutine of tsubst_pack_expansion.
9377 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9378 mechanism to store the (non complete list of) arguments of the
9379 substitution and return a non substituted pack expansion, in order
9380 to wait for when we have enough arguments to really perform the
9381 substitution. */
9383 static bool
9387 {
9388 /* If one pack has an expansion and another pack has a normal
9389 argument or if one pack has an empty argument and an another
9390 one hasn't then tsubst_pack_expansion cannot perform the
9391 substitution and need to fall back on the
9392 PACK_EXPANSION_EXTRA mechanism. */
9400 {
9403 parm_pack;
9405 {
9410 else
9412 }
9416 }
9418 }
9420 /* [temp.variadic]/6 says that:
9422 The instantiation of a pack expansion [...]
9423 produces a list E1,E2, ..., En, where N is the number of elements
9424 in the pack expansion parameters.
9426 This subroutine of tsubst_pack_expansion produces one of these Ei.
9428 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9429 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9430 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9431 INDEX is the index 'i' of the element Ei to produce. ARGS,
9432 COMPLAIN, and IN_DECL are the same parameters as for the
9433 tsubst_pack_expansion function.
9435 The function returns the resulting Ei upon successful completion,
9436 or error_mark_node.
9438 Note that this function possibly modifies the ARGS parameter, so
9439 it's the responsibility of the caller to restore it. */
9441 static tree
9443 tree parm_packs,
9445 tree args /* This parm gets
9447 tsubst_flags_t complain,
9448 tree in_decl)
9449 {
9450 tree t;
9453 /* For each parameter pack, change the substitution of the parameter
9454 pack to the ith argument in its argument pack, then expand the
9455 pattern. */
9457 {
9462 ith_elem_is_expansion |=
9465 /* Select the Ith argument from the pack. */
9468 {
9470 {
9474 }
9475 else
9477 }
9478 else
9479 {
9484 {
9486 /* Update the corresponding argument. */
9488 }
9489 else
9490 /* Re-use the ARGUMENT_PACK_SELECT. */
9492 }
9494 }
9496 /* Substitute into the PATTERN with the (possibly altered)
9497 arguments. */
9501 else
9504 /* If the Ith argument pack element is a pack expansion, then
9505 the Ith element resulting from the substituting is going to
9506 be a pack expansion as well. */
9511 }
9513 /* Substitute ARGS into T, which is an pack expansion
9514 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9515 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9516 (if only a partial substitution could be performed) or
9517 ERROR_MARK_NODE if there was an error. */
9518 tree
9520 tree in_decl)
9521 {
9522 tree pattern;
9526 tree result;
9534 /* Add in any args remembered from an earlier partial instantiation. */
9539 /* Determine the argument packs that will instantiate the parameter
9540 packs used in the expansion expression. While we're at it,
9541 compute the number of arguments to be expanded and make sure it
9542 is consistent. */
9545 {
9552 {
9556 else
9559 }
9561 {
9564 else
9565 {
9566 /* We can't rely on local_specializations for a parameter
9567 name used later in a function declaration (such as in a
9568 late-specified return type). Even if it exists, it might
9569 have the wrong value for a recursive call. Just make a
9570 dummy decl, since it's only used for its type. */
9573 /* Partial instantiation of the parm_pack, we can't build
9574 up an argument pack yet. */
9576 else
9579 }
9580 }
9583 else
9584 {
9590 }
9597 /* This can only happen if we forget to expand an argument
9598 pack somewhere else. Just return an error, silently. */
9599 {
9603 }
9606 {
9610 /* Don't bother trying to do a partial substitution with
9611 incomplete packs; we'll try again after deduction. */
9618 {
9624 pattern);
9625 else
9628 pattern);
9630 }
9632 /* Keep track of the parameter packs and their corresponding
9633 argument packs. */
9636 }
9637 else
9638 {
9639 /* We can't substitute for this parameter pack. We use a flag as
9640 well as the missing_level counter because function parameter
9641 packs don't have a level. */
9643 }
9644 }
9646 /* We cannot expand this expansion expression, because we don't have
9647 all of the argument packs we need. */
9649 {
9650 /* We got some full packs, but we can't substitute them in until we
9651 have values for all the packs. So remember these until then. */
9656 }
9658 {
9659 /* There were no real arguments, we're just replacing a parameter
9660 pack with another version of itself. Substitute into the
9661 pattern and return a PACK_EXPANSION_*. The caller will need to
9662 deal with that. */
9666 else
9670 }
9675 {
9676 /* We're in a late-specified return type, so create our own local
9677 specializations map; the current map is either NULL or (in the
9678 case of recursive unification) might have bindings that we don't
9679 want to use or alter. */
9682 }
9684 /* For each argument in each argument pack, substitute into the
9685 pattern. */
9688 {
9690 i,
9692 in_decl);
9695 {
9698 }
9699 }
9701 /* Update ARGS to restore the substitution from parameter packs to
9702 their argument packs. */
9704 {
9710 else
9711 {
9719 /* Update the corresponding argument. */
9723 else
9725 }
9726 }
9729 {
9732 }
9735 }
9737 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9738 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9739 parameter packs; all parms generated from a function parameter pack will
9740 have the same DECL_PARM_INDEX. */
9742 tree
9744 {
9746 tree patparm;
9749 {
9755 }
9756 else
9757 {
9762 }
9765 }
9767 /* Substitute ARGS into the vector or list of template arguments T. */
9769 static tree
9771 {
9783 {
9785 tree new_arg;
9790 {
9791 /* Substitute into an expansion expression. */
9795 /* Add to the expanded length adjustment the number of
9796 expanded arguments. We subtract one from this
9797 measurement, because the argument pack expression
9798 itself is already counted as 1 in
9799 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9800 the argument pack is empty. */
9802 }
9804 {
9805 /* Substitute into each of the arguments. */
9811 new_arg,
9825 }
9826 }
9827 else
9836 }
9841 /* Make space for the expanded arguments coming from template
9842 argument packs. */
9844 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9845 arguments for a member template.
9846 In that case each TREE_VEC in ORIG_T represents a level of template
9847 arguments, and ORIG_T won't carry any non defaulted argument count.
9848 It will rather be the nested TREE_VECs that will carry one.
9849 In other words, ORIG_T carries a non defaulted argument count only
9850 if it doesn't contain any nested TREE_VEC. */
9852 {
9856 }
9858 {
9862 {
9865 /* Now expand the template argument pack "in place". */
9868 }
9869 else
9870 {
9872 out++;
9873 }
9874 }
9877 }
9879 /* Return the result of substituting ARGS into the template parameters
9880 given by PARMS. If there are m levels of ARGS and m + n levels of
9881 PARMS, then the result will contain n levels of PARMS. For
9882 example, if PARMS is `template <class T> template <class U>
9883 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9884 result will be `template <int*, double, class V>'. */
9886 static tree
9888 {
9892 /* When substituting into a template, we must set
9893 PROCESSING_TEMPLATE_DECL as the template parameters may be
9894 dependent if they are based on one-another, and the dependency
9895 predicates are short-circuit outside of templates. */
9902 {
9903 tree new_vec =
9908 {
9909 tree tuple;
9921 }
9927 }
9932 }
9934 /* Return the result of substituting ARGS into one template parameter
9935 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9936 parameter and which TREE_PURPOSE is the default argument of the
9937 template parameter. */
9939 static tree
9941 {
9962 }
9964 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9965 type T. If T is not an aggregate or enumeration type, it is
9966 handled as if by tsubst. IN_DECL is as for tsubst. If
9967 ENTERING_SCOPE is nonzero, T is the context for a template which
9968 we are presently tsubst'ing. Return the substituted value. */
9970 static tree
9972 tree args,
9973 tsubst_flags_t complain,
9974 tree in_decl,
9976 {
9981 {
9986 /* Else fall through. */
9990 {
9991 tree argvec;
9992 tree context;
9993 tree r;
9997 /* In "sizeof(X<I>)" we need to evaluate "I". */
10003 /* First, determine the context for the type we are looking
10004 up. */
10007 {
10010 /* If context is a nested class inside a class template,
10011 it may still need to be instantiated (c++/33959). */
10013 }
10015 /* Then, figure out what arguments are appropriate for the
10016 type we are trying to find. For example, given:
10018 template <class T> struct S;
10019 template <class T, class U> void f(T, U) { S<U> su; }
10021 and supposing that we are instantiating f<int, double>,
10022 then our ARGS will be {int, double}, but, when looking up
10023 S we only want {double}. */
10028 else
10029 {
10033 }
10039 }
10040 else
10041 /* This is not a template type, so there's nothing to do. */
10046 }
10047 }
10049 /* Substitute into the default argument ARG (a default argument for
10050 FN), which has the indicated TYPE. */
10052 tree
10054 {
10059 /* This can happen in invalid code. */
10063 /* This default argument came from a template. Instantiate the
10064 default argument here, not in tsubst. In the case of
10065 something like:
10067 template <class T>
10068 struct S {
10069 static T t();
10070 void f(T = t());
10071 };
10073 we must be careful to do name lookup in the scope of S<T>,
10074 rather than in the current class. */
10076 /* The "this" pointer is not valid in a default argument. */
10078 {
10083 }
10086 /* The default argument expression may cause implicitly defined
10087 member functions to be synthesized, which will result in garbage
10088 collection. We must treat this situation as if we were within
10089 the body of function so as to avoid collecting live data on the
10090 stack. */
10098 /* Restore the "this" pointer. */
10100 {
10103 }
10110 /* Make sure the default argument is reasonable. */
10116 }
10118 /* Substitute into all the default arguments for FN. */
10120 static void
10122 {
10123 tree arg;
10124 tree tmpl_args;
10128 /* If this function is not yet instantiated, we certainly don't need
10129 its default arguments. */
10132 /* Don't do this again for clones. */
10137 arg;
10143 complain);
10144 }
10146 /* Substitute the ARGS into the T, which is a _DECL. Return the
10147 result of the substitution. Issue error and warning messages under
10148 control of COMPLAIN. */
10150 static tree
10152 {
10153 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10154 location_t saved_loc;
10159 /* Set the filename and linenumber to improve error-reporting. */
10164 {
10166 {
10167 /* We can get here when processing a member function template,
10168 member class template, or template template parameter. */
10170 tree spec;
10171 tree tmpl_args;
10172 tree full_args;
10175 {
10176 /* Template template parameter is treated here. */
10180 /* If we get a real template back, return it. This can happen in
10181 the context of most_specialized_class. */
10193 complain);
10196 }
10198 /* We might already have an instance of this template.
10199 The ARGS are for the surrounding class type, so the
10200 full args contain the tsubst'd args for the context,
10201 plus the innermost args from the template decl. */
10205 /* Because this is a template, the arguments will still be
10206 dependent, even after substitution. If
10207 PROCESSING_TEMPLATE_DECL is not set, the dependency
10208 predicates will short-circuit. */
10216 /* If this is a default template template argument,
10217 tsubst might not have changed anything. */
10224 {
10227 }
10229 /* Make a new template decl. It will be similar to the
10230 original, but will record the current template arguments.
10231 We also create a new function declaration, which is just
10232 like the old one, but points to this new template, rather
10233 than the old one. */
10242 {
10243 tree new_type;
10251 /* For a partial specialization, we need to keep pointing to
10252 the primary template. */
10258 }
10259 else
10260 {
10261 tree new_decl;
10273 }
10279 /* The template parameters for this new template are all the
10280 template parameters for the old template, except the
10281 outermost level of parameters. */
10284 complain);
10290 /* Record this non-type partial instantiation. */
10294 }
10298 {
10299 tree ctx;
10302 tree gen_tmpl;
10303 tree type;
10308 /* Nobody should be tsubst'ing into non-template functions. */
10312 {
10313 tree spec;
10316 /* If T is not dependent, just return it. We have to
10317 increment PROCESSING_TEMPLATE_DECL because
10318 value_dependent_expression_p assumes that nothing is
10319 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10326 /* Calculate the most general template of which R is a
10327 specialization, and the complete set of arguments used to
10328 specialize R. */
10331 (DECL_TEMPLATE_RESULT
10337 /* Check to see if we already have this specialization. */
10342 {
10345 }
10347 /* We can see more levels of arguments than parameters if
10348 there was a specialization of a member template, like
10349 this:
10351 template <class T> struct S { template <class U> void f(); }
10352 template <> template <class U> void S<int>::f(U);
10354 Here, we'll be substituting into the specialization,
10355 because that's where we can find the code we actually
10356 want to generate, but we'll have enough arguments for
10357 the most general template.
10359 We also deal with the peculiar case:
10361 template <class T> struct S {
10362 template <class U> friend void f();
10363 };
10364 template <class U> void f() {}
10365 template S<int>;
10366 template void f<double>();
10368 Here, the ARGS for the instantiation of will be {int,
10369 double}. But, we only need as many ARGS as there are
10370 levels of template parameters in CODE_PATTERN. We are
10371 careful not to get fooled into reducing the ARGS in
10372 situations like:
10374 template <class T> struct S { template <class U> void f(U); }
10375 template <class T> template <> void S<T>::f(int) {}
10377 which we can spot because the pattern will be a
10378 specialization in this case. */
10380 parms_depth =
10385 }
10386 else
10387 {
10388 /* This special case arises when we have something like this:
10390 template <class T> struct S {
10391 friend void f<int>(int, double);
10392 };
10394 Here, the DECL_TI_TEMPLATE for the friend declaration
10395 will be an IDENTIFIER_NODE. We are being called from
10396 tsubst_friend_function, and we want only to create a
10397 new decl (R) with appropriate types so that we can call
10398 determine_specialization. */
10400 }
10403 {
10406 else
10410 }
10411 else
10412 {
10415 }
10420 /* If we hit excessive deduction depth, the type is bogus even if
10421 it isn't error_mark_node, so don't build a decl. */
10425 /* We do NOT check for matching decls pushed separately at this
10426 point, as they may not represent instantiations of this
10427 template, and in any case are considered separate under the
10428 discrete model. */
10432 /* Clear out the mangled name and RTL for the instantiation. */
10435 /* Leave DECL_INITIAL set on deleted instantiations. */
10440 /* OpenMP UDRs have the only argument a reference to the declared
10441 type. We want to diagnose if the declared type is a reference,
10442 which is invalid, but as references to references are usually
10443 quietly merged, diagnose it here. */
10445 {
10446 tree argtype
10451 "reference type %qT in "
10455 argtype);
10456 }
10459 /* Type-conversion operator. Reconstruct the name, in
10460 case it's the name of one of the template's parameters. */
10470 /* If this is an instantiation of a function with internal
10471 linkage, we already know what object file linkage will be
10472 assigned to the instantiation. */
10481 /* We'll re-clone as appropriate in instantiate_template. */
10484 /* If we aren't complaining now, return on error before we register
10485 the specialization so that we'll complain eventually. */
10491 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10492 this in the special friend case mentioned above where
10493 GEN_TMPL is NULL. */
10495 {
10500 tree new_r
10503 /* We instantiated this while substituting into
10504 the type earlier (template/friend54.C). */
10507 /* We're not supposed to instantiate default arguments
10508 until they are called, for a template. But, for a
10509 declaration like:
10511 template <class T> void f ()
10512 { extern void g(int i = T()); }
10514 we should do the substitution when the template is
10515 instantiated. We handle the member function case in
10516 instantiate_class_template since the default arguments
10517 might refer to other members of the class. */
10522 }
10523 else
10526 /* Copy the list of befriending classes. */
10530 {
10534 in_decl);
10535 }
10538 {
10544 /* If this is an instantiation of a member template, clone it.
10545 If it isn't, that'll be handled by
10546 clone_constructors_and_destructors. */
10549 }
10560 /* Possibly limit visibility based on template args. */
10563 {
10567 }
10575 }
10579 {
10587 {
10588 /* If there is a local specialization that isn't a
10589 parameter pack, it means that we're doing a "simple"
10590 substitution from inside tsubst_pack_expansion. Just
10591 return the local specialization (which will be a single
10592 parm). */
10599 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10600 the parameters in this function parameter pack. */
10604 {
10607 /* Zero-length parameter packs are boring. Just substitute
10608 into the chain. */
10612 }
10613 else
10614 {
10615 /* All we did was update the type. Make a note of that. */
10618 }
10619 }
10621 /* Loop through all of the parameters we'll build. When T is
10622 a function parameter pack, LEN is the number of expanded
10623 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10626 {
10633 /* We're on the Ith parameter of the function parameter
10634 pack. */
10635 {
10636 /* Get the Ith type. */
10639 /* Rename the parameter to include the index. */
10642 }
10644 /* We're dealing with a normal parameter. */
10652 {
10655 else
10658 }
10668 /* Keep track of the first new parameter we
10669 generate. That's what will be returned to the
10670 caller. */
10674 /* Build a proper chain of parameters when substituting
10675 into a function parameter pack. */
10678 }
10680 /* If cp_unevaluated_operand is set, we're just looking for a
10681 single dummy parameter, so don't keep going. */
10686 /* FIRST_R contains the start of the chain we've built. */
10688 }
10692 {
10699 {
10700 /* This field is a lambda capture pack. Return a TREE_VEC of
10701 the expanded fields to instantiate_class_template_1 and
10702 store them in the specializations hash table as a
10703 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10707 {
10710 }
10711 else
10712 {
10713 /* All we did was update the type. Make a note of that. */
10716 }
10717 }
10720 {
10723 {
10727 }
10737 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10738 non-bit-fields DECL_INITIAL is a non-static data member
10739 initializer, which gets deferred instantiation. */
10745 {
10746 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10747 NSDMI in perform_member_init. Still set DECL_INITIAL
10748 so that we know there is one. */
10753 }
10754 /* We don't have to set DECL_CONTEXT here; it is set by
10755 finish_member_declaration. */
10763 }
10766 {
10774 }
10775 }
10779 /* We reach here only for member using decls. We also need to check
10780 uses_template_parms because DECL_DEPENDENT_P is not set for a
10781 using-declaration that designates a member of the current
10782 instantiation (c++/53549). */
10785 {
10792 else
10793 {
10796 }
10797 }
10798 else
10799 {
10802 }
10807 {
10810 tree spec;
10812 tree ctx;
10818 {
10819 /* If this is the canonical decl, we don't have to
10820 mess with instantiations, and often we can't (for
10821 typename, template type parms and such). Note that
10822 TYPE_NAME is not correct for the above test if
10823 we've copied the type for a typedef. */
10829 }
10831 /* Check to see if we already have the specialization we
10832 need. */
10835 {
10836 /* T is a static data member or namespace-scope entity.
10837 We have to substitute into namespace-scope variables
10838 (even though such entities are never templates) because
10839 of cases like:
10841 template <class T> void f() { extern T t; }
10843 where the entity referenced is not known until
10844 instantiation time. */
10848 {
10850 complain,
10852 /* If CTX is unchanged, then T is in fact the
10853 specialization we want. That situation occurs when
10854 referencing a static data member within in its own
10855 class. We can use pointer equality, rather than
10856 same_type_p, because DECL_CONTEXT is always
10857 canonical... */
10860 /* ... unless T is a member template; in which
10861 case our caller can be willing to create a
10862 specialization of that template represented
10863 by T. */
10867 }
10870 {
10878 }
10879 }
10880 else
10881 {
10882 /* A local variable. */
10884 /* Subsequent calls to pushdecl will fill this in. */
10887 }
10888 /* If we already have the specialization we need, there is
10889 nothing more to do. */
10891 {
10894 }
10896 /* Create a new node for the specialization we need. */
10899 {
10902 else
10909 }
10911 {
10912 /* Even if the original location is out of scope, the
10913 newly substituted one is not. */
10920 {
10921 /* It may seem that this case cannot occur, since:
10923 typedef void f();
10924 void g() { f x; }
10926 declares a function, not a variable. However:
10928 typedef void f();
10929 template <typename T> void g() { T t; }
10930 template void g<f>();
10932 is an attempt to declare a variable with function
10933 type. */
10935 /* R is not yet sufficiently initialized, so we
10936 just use its name. */
10939 }
10941 /* Wait until cp_finish_decl to set this again, to handle
10942 circular dependency (template/instantiate6.C). */
10947 {
10952 {
10955 }
10957 }
10958 }
10964 /* Clear out the mangled name and RTL for the instantiation. */
10968 /* The initializer must not be expanded until it is required;
10969 see [temp.inst]. */
10975 {
10976 /* Possibly limit visibility based on template args. */
10979 {
10983 }
10985 }
10988 {
10989 /* A static data member declaration is always marked
10990 external when it is declared in-class, even if an
10991 initializer is present. We mimic the non-template
10992 processing here. */
10998 }
11008 /* Preserve a typedef that names a type. */
11010 {
11013 }
11016 }
11021 }
11022 #undef RETURN
11024 out:
11025 /* Restore the file and line information. */
11029 }
11031 /* Substitute into the ARG_TYPES of a function type.
11032 If END is a TREE_CHAIN, leave it and any following types
11033 un-substituted. */
11035 static tree
11037 tree args,
11038 tree end,
11039 tsubst_flags_t complain,
11040 tree in_decl)
11041 {
11042 tree remaining_arg_types;
11046 tree default_arg;
11057 {
11058 /* For a pack expansion, perform substitution on the
11059 entire expression. Later on, we'll handle the arguments
11060 one-by-one. */
11065 /* So that we'll spin through the parameters, one by one. */
11067 else
11068 {
11069 /* We only partially substituted into the parameter
11070 pack. Our type is TYPE_PACK_EXPANSION. */
11073 }
11074 }
11087 {
11089 {
11093 }
11095 }
11096 /* DR 657. */
11100 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11101 top-level qualifiers as required. */
11104 /* We do not substitute into default arguments here. The standard
11105 mandates that they be instantiated only when needed, which is
11106 done in build_over_call. */
11110 {
11111 /* We've instantiated a template before its default arguments
11112 have been parsed. This can happen for a nested template
11113 class, and is not an error unless we require the default
11114 argument in a call of this function. */
11115 remaining_arg_types =
11118 }
11119 else
11120 remaining_arg_types =
11122 }
11125 }
11127 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11128 *not* handle the exception-specification for FNTYPE, because the
11129 initial substitution of explicitly provided template parameters
11130 during argument deduction forbids substitution into the
11131 exception-specification:
11133 [temp.deduct]
11135 All references in the function type of the function template to the
11136 corresponding template parameters are replaced by the specified tem-
11137 plate argument values. If a substitution in a template parameter or
11138 in the function type of the function template results in an invalid
11139 type, type deduction fails. [Note: The equivalent substitution in
11140 exception specifications is done only when the function is instanti-
11141 ated, at which point a program is ill-formed if the substitution
11142 results in an invalid type.] */
11144 static tree
11146 tree args,
11147 tsubst_flags_t complain,
11148 tree in_decl)
11149 {
11150 tree return_type;
11151 tree arg_types;
11152 tree fntype;
11154 /* The TYPE_CONTEXT is not used for function/method types. */
11157 /* Substitute the return type. */
11161 /* DR 486 clarifies that creation of a function type with an
11162 invalid return type is a deduction failure. */
11165 {
11167 {
11170 else
11172 }
11174 }
11175 /* And DR 657. */
11179 /* Substitute the argument types. */
11185 /* Construct a new type node and return it. */
11187 {
11192 }
11193 else
11194 {
11196 /* Don't pick up extra function qualifiers from the basetype. */
11199 {
11200 /* [temp.deduct]
11202 Type deduction may fail for any of the following
11203 reasons:
11205 -- Attempting to create "pointer to member of T" when T
11206 is not a class type. */
11209 r);
11211 }
11216 }
11220 }
11222 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11223 ARGS into that specification, and return the substituted
11224 specification. If there is no specification, return NULL_TREE. */
11226 static tree
11228 tree args,
11229 tsubst_flags_t complain,
11230 tree in_decl,
11232 {
11233 tree specs;
11234 tree new_specs;
11239 {
11240 /* A noexcept-specifier. */
11245 {
11246 /* Defer instantiation of noexcept-specifiers to avoid
11247 excessive instantiations (c++/49107). */
11250 {
11251 /* We already partially instantiated this member template,
11252 so combine the new args with the old. */
11257 }
11258 else
11259 {
11262 }
11263 }
11264 else
11265 new_specs = tsubst_copy_and_build
11269 }
11271 {
11274 else
11276 {
11277 tree spec;
11282 {
11283 /* Expand the pack expansion type. */
11286 in_decl);
11292 else
11293 {
11294 /* We're substituting into a member template, so
11295 we got a TYPE_PACK_EXPANSION back. Add that
11296 expansion and move on. */
11300 expanded_specs,
11301 complain);
11304 }
11305 }
11308 {
11311 else
11316 complain);
11317 }
11320 }
11321 }
11323 }
11325 /* Take the tree structure T and replace template parameters used
11326 therein with the argument vector ARGS. IN_DECL is an associated
11327 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11328 Issue error and warning messages under control of COMPLAIN. Note
11329 that we must be relatively non-tolerant of extensions here, in
11330 order to preserve conformance; if we allow substitutions that
11331 should not be allowed, we may allow argument deductions that should
11332 not succeed, and therefore report ambiguous overload situations
11333 where there are none. In theory, we could allow the substitution,
11334 but indicate that it should have failed, and allow our caller to
11335 make sure that the right thing happens, but we don't try to do this
11336 yet.
11338 This function is used for dealing with types, decls and the like;
11339 for expressions, use tsubst_expr or tsubst_copy. */
11341 tree
11343 {
11366 else
11371 /* Reuse typedefs. We need to do this to handle dependent attributes,
11372 such as attribute aligned. */
11375 {
11379 {
11380 /* DECL represents an alias template and we want to
11381 instantiate it. */
11385 }
11389 {
11393 }
11398 else
11399 /* The typedef is from a non-template context. */
11403 {
11405 r = cp_build_qualified_type_real
11409 }
11410 else
11411 {
11412 /* We don't have an instantiation yet, so drop the typedef. */
11417 }
11418 }
11431 {
11457 {
11463 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11464 needed. */
11470 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11471 with TREE_SIDE_EFFECTS that indicates this is not an integral
11472 constant expression. */
11475 {
11478 }
11481 }
11487 {
11500 {
11504 {
11505 /* See through ARGUMENT_PACK_SELECT arguments. */
11507 /* If the selected argument is an expansion E, that most
11508 likely means we were called from
11509 gen_elem_of_pack_expansion_instantiation during the
11510 substituting of pack an argument pack (which Ith
11511 element is a pack expansion, where I is
11512 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11513 In this case, the Ith element resulting from this
11514 substituting is going to be a pack expansion, which
11515 pattern is the pattern of E. Let's return the
11516 pattern of E, and
11517 gen_elem_of_pack_expansion_instantiation will
11518 build the resulting pack expansion from it. */
11521 }
11522 }
11527 {
11529 /* If ARG is an argument pack, we don't actually want to
11530 perform a substitution here, because substitutions
11531 for argument packs are only done
11532 element-by-element. We can get to this point when
11533 substituting the type of a non-type template
11534 parameter pack, when that type actually contains
11535 template parameter packs from an outer template, e.g.,
11537 template<typename... Types> struct A {
11538 template<Types... Values> struct B { };
11539 }; */
11543 {
11549 return cp_build_qualified_type_real
11551 }
11553 {
11554 /* We are processing a type constructed from a
11555 template template parameter. */
11566 /* Consider this code:
11568 template <template <class> class Template>
11569 struct Internal {
11570 template <class Arg> using Bind = Template<Arg>;
11571 };
11573 template <template <class> class Template, class Arg>
11574 using Instantiate = Template<Arg>; //#0
11576 template <template <class> class Template,
11577 class Argument>
11578 using Bind =
11579 Instantiate<Internal<Template>::template Bind,
11580 Argument>; //#1
11582 When #1 is parsed, the
11583 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11584 parameter `Template' in #0 matches the
11585 UNBOUND_CLASS_TEMPLATE representing the argument
11586 `Internal<Template>::template Bind'; We then want
11587 to assemble the type `Bind<Argument>' that can't
11588 be fully created right now, because
11589 `Internal<Template>' not being complete, the Bind
11590 template cannot be looked up in that context. So
11591 we need to "store" `Bind<Argument>' for later
11592 when the context of Bind becomes complete. Let's
11593 store that in a TYPENAME_TYPE. */
11597 argvec),
11598 typename_type,
11599 complain);
11601 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11602 are resolving nested-types in the signature of a
11603 member function templates. Otherwise ARG is a
11604 TEMPLATE_DECL and is the real template to be
11605 instantiated. */
11613 complain);
11614 return cp_build_qualified_type_real
11616 }
11617 else
11618 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11620 }
11623 /* This can happen during the attempted tsubst'ing in
11624 unify. This means that we don't yet have any information
11625 about the template parameter in question. */
11628 /* Early in template argument deduction substitution, we don't
11629 want to reduce the level of 'auto', or it will be confused
11630 with a normal template parm in subsequent deduction. */
11634 /* If we get here, we must have been looking at a parm for a
11635 more deeply nested template. Make a new version of this
11636 template parameter, but with a lower level. */
11638 {
11643 {
11645 r = cp_build_qualified_type_real
11649 }
11650 else
11651 {
11662 /* We have reduced the level of the template
11663 template parameter, but not the levels of its
11664 template parameters, so canonical_type_parameter
11665 will not be able to find the canonical template
11666 template parameter for this level. Thus, we
11667 require structural equality checking to compare
11668 TEMPLATE_TEMPLATE_PARMs. */
11672 else
11676 {
11684 }
11685 }
11694 }
11697 }
11700 {
11708 {
11712 }
11715 {
11719 }
11722 {
11726 }
11732 }
11735 /* We should never be tsubsting a binfo. */
11739 /* A vector of template arguments. */
11745 {
11749 /* [temp.deduct]
11751 Type deduction may fail for any of the following
11752 reasons:
11754 -- Attempting to create a pointer to reference type.
11755 -- Attempting to create a reference to a reference type or
11756 a reference to void.
11758 Core issue 106 says that creating a reference to a reference
11759 during instantiation is no longer a cause for failure. We
11760 only enforce this check in strict C++98 mode. */
11764 {
11767 /* We keep track of the last time we issued this error
11768 message to avoid spewing a ton of messages during a
11769 single bad template instantiation. */
11772 {
11777 else
11780 }
11783 }
11787 {
11789 {
11792 type);
11793 else
11795 type);
11796 }
11798 }
11800 {
11804 }
11806 /* In C++0x, during template argument substitution, when there is an
11807 attempt to create a reference to a reference type, reference
11808 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11810 "If a template-argument for a template-parameter T names a type
11811 that is a reference to a type A, an attempt to create the type
11812 'lvalue reference to cv T' creates the type 'lvalue reference to
11813 A,' while an attempt to create the type type rvalue reference to
11814 cv T' creates the type T"
11815 */
11816 r = cp_build_reference_type
11819 else
11826 {
11828 pedwarn
11830 code == REFERENCE_TYPE
11833 else
11835 }
11838 /* Will this ever be needed for TYPE_..._TO values? */
11842 }
11844 {
11847 {
11848 /* [temp.deduct]
11850 Type deduction may fail for any of the following
11851 reasons:
11853 -- Attempting to create "pointer to member of T" when T
11854 is not a class type. */
11858 }
11860 {
11864 }
11866 {
11870 }
11873 {
11874 /* The type of the implicit object parameter gets its
11875 cv-qualifiers from the FUNCTION_TYPE. */
11876 tree memptr;
11877 tree method_type
11882 complain);
11883 }
11884 else
11887 complain);
11888 }
11891 {
11892 tree fntype;
11893 tree specs;
11898 /* Substitute the exception specification. */
11906 }
11908 {
11913 /* As an optimization, we avoid regenerating the array type if
11914 it will obviously be the same as T. */
11918 /* These checks should match the ones in grokdeclarator.
11920 [temp.deduct]
11922 The deduction may fail for any of the following reasons:
11924 -- Attempting to create an array with an element type that
11925 is void, a function type, or a reference type, or [DR337]
11926 an abstract class type. */
11930 {
11934 }
11942 {
11945 }
11948 }
11951 {
11961 {
11965 }
11967 {
11968 /* Normally, make_typename_type does not require that the CTX
11969 have complete type in order to allow things like:
11971 template <class T> struct S { typename S<T>::X Y; };
11973 But, such constructs have already been resolved by this
11974 point, so here CTX really should have complete type, unless
11975 it's a partial instantiation. */
11978 {
11982 }
11983 }
11990 {
11993 }
11996 {
11998 {
12002 else
12004 }
12006 {
12010 else
12012 }
12013 }
12015 return cp_build_qualified_type_real
12017 }
12020 {
12032 }
12035 {
12036 tree type;
12052 complain);
12053 }
12056 {
12057 tree type;
12075 else
12076 {
12080 /* In a template ~id could be either a complement expression
12081 or an unqualified-id naming a destructor; if instantiating
12082 it produces an expression, it's not an id-expression or
12083 member access. */
12086 }
12090 complain);
12091 }
12094 {
12098 }
12102 {
12104 tree packed_out =
12106 args,
12107 complain,
12108 in_decl);
12111 /* For template nontype argument packs, also substitute into
12112 the type. */
12117 }
12132 /* We should use one of the expression tsubsts for these codes. */
12138 }
12139 }
12141 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12142 type of the expression on the left-hand side of the "." or "->"
12143 operator. */
12145 static tree
12148 {
12149 tree name;
12150 tree qualifying_scope;
12151 tree fns;
12152 tree optype;
12157 /* A baselink indicates a function from a base class. Both the
12158 BASELINK_ACCESS_BINFO and the base class referenced may
12159 indicate bases of the template class, rather than the
12160 instantiated class. In addition, lookups that were not
12161 ambiguous before may be ambiguous now. Therefore, we perform
12162 the lookup again. */
12169 {
12176 }
12184 /* If lookup found a single function, mark it as used at this
12185 point. (If it lookup found multiple functions the one selected
12186 later by overload resolution will be marked as used at that
12187 point.) */
12193 /* Add back the template arguments, if present. */
12198 template_args);
12199 /* Update the conversion operator type. */
12207 qualifying_scope,
12208 object_type);
12210 }
12212 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12213 true if the qualified-id will be a postfix-expression in-and-of
12214 itself; false if more of the postfix-expression follows the
12215 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12216 of "&". */
12218 static tree
12222 {
12223 tree expr;
12224 tree scope;
12225 tree name;
12227 tree template_args;
12232 /* Figure out what name to look up. */
12235 {
12243 }
12244 else
12245 {
12248 }
12250 /* Substitute into the qualifying scope. When there are no ARGS, we
12251 are just trying to simplify a non-dependent expression. In that
12252 case the qualifying scope may be dependent, and, in any case,
12253 substituting will not help. */
12256 {
12259 }
12260 else
12264 {
12269 }
12272 {
12274 {
12275 /* A BIT_NOT_EXPR is used to represent a destructor. */
12277 {
12281 }
12282 else
12285 }
12286 else
12290 {
12292 {
12296 }
12298 }
12299 }
12302 {
12304 scope);
12305 /* Remember that there was a reference to this entity. */
12307 }
12310 {
12316 }
12325 {
12326 expr = (adjust_result_of_qualified_name_lookup
12328 expr = (finish_qualified_id_expr
12332 }
12334 /* Expressions do not generally have reference type. */
12336 /* However, if we're about to form a pointer-to-member, we just
12337 want the referenced member referenced. */
12342 }
12344 /* Like tsubst, but deals with expressions. This function just replaces
12345 template parms; to finish processing the resultant expression, use
12346 tsubst_copy_and_build or tsubst_expr. */
12348 static tree
12350 {
12352 tree r;
12360 {
12365 {
12366 /* We get here for a use of 'this' in an NSDMI. */
12372 /* This can happen for a parameter name used later in a function
12373 declaration (such as in a late-specified return type). Just
12374 make a dummy decl, since it's only used for its type. */
12377 /* Give it the template pattern as its context; its true context
12378 hasn't been instantiated yet and this is good enough for
12379 mangling. */
12381 }
12389 {
12390 tree enum_type;
12391 tree v;
12395 /* There is no need to substitute into namespace-scope
12396 enumerators. */
12399 /* If ARGS is NULL, then T is known to be non-dependent. */
12403 /* Unfortunately, we cannot just call lookup_name here.
12404 Consider:
12406 template <int I> int f() {
12407 enum E { a = I };
12408 struct S { void g() { E e = a; } };
12409 };
12411 When we instantiate f<7>::S::g(), say, lookup_name is not
12412 clever enough to find f<7>::a. */
12413 enum_type
12423 /* We didn't find the name. That should never happen; if
12424 name-lookup found it during preliminary parsing, we
12425 should find it again here during instantiation. */
12427 }
12432 {
12433 /* Check for a local specialization set up by
12434 tsubst_pack_expansion. */
12437 {
12441 }
12443 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12444 tsubst_decl put in the hash table. */
12446 }
12449 {
12450 tree ctx;
12455 {
12458 {
12462 }
12464 }
12465 }
12474 {
12477 {
12479 {
12480 /* Just use name lookup to find a member alias for an
12481 anonymous union, but then add it to the hash table. */
12485 }
12486 else
12487 {
12488 /* This can happen for a variable used in a late-specified
12489 return type of a local lambda. Just make a dummy decl
12490 since it's only used for its type. */
12495 }
12496 }
12497 }
12498 else
12507 /* An OVERLOAD will always be a non-dependent overload set; an
12508 overload set from function scope will just be represented with an
12509 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12525 {
12526 /* Template template argument like the following example need
12527 special treatment:
12529 template <template <class> class TT> struct C {};
12530 template <class T> struct D {
12531 template <class U> struct E {};
12532 C<E> c; // #1
12533 };
12534 D<int> d; // #2
12536 We are processing the template argument `E' in #1 for
12537 the template instantiation #2. Originally, `E' is a
12538 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12539 have to substitute this with one having context `D<int>'. */
12543 }
12544 else
12545 /* Ordinary template template argument. */
12556 return build1
12562 {
12572 /* We only want to compute the number of arguments. */
12586 {
12593 else
12596 }
12597 else
12599 }
12601 {
12609 }
12610 /* Fall through */
12626 return build1
12631 {
12632 tree object;
12633 tree name;
12638 {
12642 }
12645 {
12655 }
12660 in_decl);
12661 else
12664 }
12702 return build_nt
12715 return build_nt
12722 {
12730 }
12736 {
12737 r = build_nt
12743 }
12746 {
12747 r = build_nt
12753 }
12756 {
12757 r = build_nt
12763 }
12766 {
12767 /* Substituted template arguments */
12776 }
12779 {
12799 }
12824 /* Fall through. */
12827 {
12830 }
12831 else
12835 /* This is handled by tsubst_copy_and_build. */
12841 in_decl),
12845 /* We shouldn't have built any of these during initial template
12846 generation. Instead, they should be built during instantiation
12847 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12851 r = build2
12871 {
12872 /* Instantiate any typedefs in the type. */
12877 }
12880 /* These can sometimes show up in a partial instantiation, but never
12881 involve template parms. */
12886 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12889 }
12890 }
12892 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12894 static tree
12897 {
12901 {
12907 {
12910 {
12916 }
12917 /* FALLTHRU */
12945 {
12948 {
12955 }
12956 else
12958 }
12988 }
12989 }
12995 }
12997 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12999 static tree
13001 tree in_decl)
13002 {
13003 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13023 {
13026 else
13027 {
13031 }
13032 }
13037 #undef RECUR
13038 }
13040 /* Substitute one OMP_FOR iterator. */
13042 static void
13047 {
13048 #define RECUR(NODE) \
13049 tsubst_expr ((NODE), args, complain, in_decl, \
13050 integral_constant_expression_p)
13058 /* Do this before substituting into decl to handle 'auto'. */
13067 {
13071 }
13076 {
13083 complain);
13084 else
13091 }
13094 {
13095 tree c;
13097 {
13108 }
13110 {
13115 {
13118 }
13119 }
13120 }
13126 else
13130 {
13141 {
13148 }
13149 else
13155 {
13161 }
13165 {
13172 }
13173 else
13179 }
13185 #undef RECUR
13186 }
13188 /* Like tsubst_copy for expressions, etc. but also does semantic
13189 processing. */
13191 static tree
13194 {
13195 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13196 #define RECUR(NODE) \
13197 tsubst_expr ((NODE), args, complain, in_decl, \
13198 integral_constant_expression_p)
13201 tree r;
13202 location_t loc;
13214 {
13216 {
13217 tree_stmt_iterator i;
13221 }
13236 else
13245 {
13247 tree init;
13253 {
13256 tree decl;
13264 else
13266 }
13268 {
13269 /* Don't build up decls for a variadic capture proxy, we'll
13270 instantiate the elements directly as needed. */
13272 }
13273 else
13274 {
13278 {
13279 /* By marking the declaration as instantiated, we avoid
13280 trying to instantiate it. Since instantiate_decl can't
13281 handle local variables, and since we've already done
13282 all that needs to be done, that's the right thing to
13283 do. */
13288 /* Anonymous aggregates are a special case. */
13291 {
13294 {
13298 }
13300 }
13306 {
13311 }
13312 else
13313 {
13318 {
13319 /* For __PRETTY_FUNCTION__ we have to adjust the
13320 initializer. */
13324 }
13325 else
13326 {
13330 {
13331 /* If we had an initializer but it
13332 instantiated to nothing,
13333 value-initialize the object. This will
13334 only occur when the initializer was a
13335 pack expansion where the parameter packs
13336 used in that expansion were of length
13337 zero. */
13339 complain);
13342 }
13343 else
13345 }
13348 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13351 }
13352 }
13353 }
13356 }
13371 {
13381 }
13408 {
13412 }
13420 else
13428 else
13455 {
13457 tree label;
13462 }
13468 /* Computed goto's must be tsubst'd into. On the other hand,
13469 non-computed gotos must not be; the identifier in question
13470 will have no binding. */
13472 else
13478 tmp = finish_asm_stmt
13485 {
13490 }
13495 {
13500 }
13501 else
13502 {
13507 else
13514 else
13520 else
13522 }
13526 {
13530 {
13532 /* Prevent instantiate_decl from trying to instantiate
13533 this variable. We've already done all that needs to be
13534 done. */
13537 }
13542 }
13548 {
13549 /* Local classes are not independent templates; they are
13550 instantiated along with their containing function. And this
13551 way we don't have to deal with pushing out of one local class
13552 to instantiate a member of another local class. */
13553 tree fn;
13554 /* Closures are handled by the LAMBDA_EXPR. */
13560 }
13564 {
13565 tree condition;
13568 condition =
13570 args,
13579 }
13603 {
13612 {
13617 }
13629 integral_constant_expression_p);
13638 else
13639 {
13647 }
13650 }
13695 {
13700 {
13703 }
13709 }
13710 else
13711 {
13718 {
13721 }
13724 {
13729 {
13732 }
13738 }
13739 else
13740 {
13744 }
13747 }
13751 {
13757 {
13761 {
13766 }
13770 }
13771 else
13772 {
13777 }
13778 }
13803 /* If the first operand was a statement, we're done with it. */
13807 complain));
13819 integral_constant_expression_p));
13820 }
13823 out:
13826 #undef RECUR
13827 #undef RETURN
13828 }
13830 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
13831 function. For description of the body see comment above
13832 cp_parser_omp_declare_reduction_exprs. */
13834 static void
13836 {
13842 tree_stmt_iterator tsi;
13853 {
13872 }
13874 {
13894 }
13895 }
13897 /* T is a postfix-expression that is not being used in a function
13898 call. Return the substituted version of T. */
13900 static tree
13902 tsubst_flags_t complain,
13903 tree in_decl)
13904 {
13908 else
13914 }
13916 /* Like tsubst but deals with expressions and performs semantic
13917 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13919 tree
13921 tree args,
13922 tsubst_flags_t complain,
13923 tree in_decl,
13926 {
13927 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13928 #define RECUR(NODE) \
13929 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13931 integral_constant_expression_p)
13934 location_t loc;
13943 /* N3276 decltype magic only applies to calls at the top level or on the
13944 right side of a comma. */
13949 {
13952 /* Fall through. */
13954 {
13955 tree decl;
13956 cp_id_kind idk;
13961 {
13964 }
13966 /* Look up the name. */
13969 /* By convention, expressions use ERROR_MARK_NODE to indicate
13970 failure, not NULL_TREE. */
13976 integral_constant_expression_p,
13984 input_location);
13988 {
13992 }
13994 }
13997 {
13998 tree object;
14006 {
14009 }
14010 else
14017 else
14019 }
14022 {
14026 {
14027 /* A type conversion to reference type will be enclosed in
14028 such an indirect ref, but the substitution of the cast
14029 will have also added such an indirect ref. */
14032 }
14033 else
14037 }
14045 {
14052 flags));
14053 }
14066 {
14067 tree type;
14073 {
14078 }
14084 {
14102 }
14106 }
14140 else
14142 in_decl);
14177 {
14178 tree r;
14182 r = build_x_binary_op
14186 ? ERROR_MARK
14190 ? ERROR_MARK
14200 }
14217 {
14226 }
14230 /* Fall through */
14233 {
14234 tree r;
14240 {
14241 /* When there are no ARGS, we are trying to evaluate a
14242 non-dependent expression from the parser. Trying to do
14243 the substitutions may not work. */
14246 }
14247 else
14248 {
14253 else
14256 /*integral_constant_expression_p=*/
14260 }
14264 else
14268 {
14270 {
14272 {
14276 }
14277 else
14281 }
14283 }
14285 }
14288 {
14298 }
14312 {
14313 tree r;
14317 r = build_x_modify_expr
14323 /* TREE_NO_WARNING must be set if either the expression was
14324 parenthesized or it uses an operator such as >>= rather
14325 than plain assignment. In the former case, it was already
14326 set and must be copied. In the latter case,
14327 build_x_modify_expr sets it and it must not be reset
14328 here. */
14335 }
14340 /* Remember that there was a reference to this entity. */
14346 {
14351 tree ret;
14355 else
14356 {
14360 }
14362 /* If there was an initializer in the original tree, but it
14363 instantiated to an empty list, then we should pass a
14364 non-NULL empty vector to tell build_new that it was an
14365 empty initializer() rather than no initializer. This can
14366 only happen when the initializer is a pack expansion whose
14367 parameter packs are of length zero. */
14370 else
14371 {
14375 else
14376 {
14379 }
14380 }
14387 complain);
14395 }
14403 complain));
14406 {
14410 integral_constant_expression_p);
14412 op0,
14415 }
14418 {
14419 tree function;
14424 tree ret;
14427 /* When we parsed the expression, we determined whether or
14428 not Koenig lookup should be performed. */
14431 {
14436 }
14438 {
14439 /* Do nothing; calling tsubst_copy_and_build on an identifier
14440 would incorrectly perform unqualified lookup again.
14442 Note that we can also have an IDENTIFIER_NODE if the earlier
14443 unqualified lookup found a member function; in that case
14444 koenig_p will be false and we do want to do the lookup
14445 again to find the instantiated member function.
14447 FIXME but doing that causes c++/15272, so we need to stop
14448 using IDENTIFIER_NODE in that situation. */
14450 }
14451 else
14452 {
14454 {
14460 }
14461 else
14466 /* Avoid error about taking the address of a constructor. */
14470 in_decl,
14472 integral_constant_expression_p);
14476 }
14481 {
14486 else
14487 {
14488 /* Expand the pack expansion and push each entry onto
14489 CALL_ARGS. */
14492 {
14497 {
14502 }
14503 }
14504 else
14505 {
14506 /* A partial substitution. Add one entry. */
14508 }
14509 }
14510 }
14512 /* We do not perform argument-dependent lookup if normal
14513 lookup finds a non-function, in accordance with the
14514 expected resolution of DR 218. */
14517 /* If lookup found a member function, the Koenig lookup is
14518 not appropriate, even if an unqualified-name was used
14519 to denote the function. */
14522 /* Only do this when substitution turns a dependent call
14523 into a non-dependent call. */
14530 {
14532 {
14533 /* For backwards compatibility and good diagnostics, try
14534 the unqualified lookup again if we aren't in SFINAE
14535 context. */
14536 tree unq = (tsubst_copy_and_build
14538 integral_constant_expression_p));
14543 {
14552 "%qD was not declared in this scope, "
14553 "and no declarations were found by "
14554 "argument-dependent lookup at the point "
14556 {
14560 {
14562 input_location);
14564 "declarations in dependent base %qT are "
14570 else
14574 }
14575 else
14578 }
14580 }
14581 }
14583 {
14588 }
14589 }
14591 /* Remember that there was a reference to this entity. */
14595 /* Put back tf_decltype for the actual call. */
14600 complain);
14602 {
14617 complain);
14618 else
14619 ret = (build_new_method_call
14624 complain));
14625 }
14626 else
14629 koenig_p,
14630 complain);
14635 }
14638 {
14643 {
14645 {
14650 }
14651 else
14652 {
14657 }
14658 }
14659 else
14660 {
14663 }
14667 }
14674 input_location));
14677 {
14685 {
14686 /* We have pack expansions, so expand those and
14687 create a new list out of it. */
14690 tree chain;
14693 /* Expand the argument expressions. */
14701 /* Build the rest of the list. */
14706 /* Determine the number of arguments. */
14708 {
14711 }
14714 else
14715 {
14716 /* Since we only performed a partial substitution into
14717 the argument pack, we only RETURN (a single list
14718 node. */
14725 }
14727 /* Convert the argument vectors into a TREE_LIST */
14730 {
14731 /* Grab the Ith values. */
14732 i--;
14735 value
14739 /* Build the list (backwards). */
14741 }
14744 }
14760 }
14763 {
14764 tree object;
14765 tree object_type;
14766 tree member;
14770 /* Remember that there was a reference to this entity. */
14780 else
14788 {
14790 {
14795 {
14798 }
14800 {
14805 }
14806 }
14807 }
14810 {
14811 /* Lookup the template functions now that we know what the
14812 scope is. */
14820 {
14823 args);
14824 member = (adjust_result_of_qualified_name_lookup
14826 object_type));
14827 }
14828 else
14829 {
14831 input_location);
14833 }
14834 }
14838 {
14840 {
14844 else
14847 }
14849 }
14855 complain));
14856 }
14863 {
14871 tree r;
14876 /* digest_init will do the wrong thing if we let it. */
14880 /* We do not want to process the index of aggregate
14881 initializers as they are identifier nodes which will be
14882 looked up by digest_init. */
14888 {
14890 /* An identifier index is looked up in the type
14891 being initialized, not the current scope. */
14896 {
14897 /* Substitute into the pack expansion. */
14899 in_decl);
14903 ;
14905 /* Just move the argument into place. */
14907 else
14908 {
14909 /* Update the length of the final CONSTRUCTOR
14910 arguments vector, and note that we will need to
14911 copy.*/
14914 }
14915 }
14916 else
14918 }
14921 {
14926 {
14928 {
14933 }
14934 else
14936 }
14937 }
14947 }
14950 {
14953 {
14956 }
14957 else
14958 {
14961 }
14962 }
14968 {
14969 /* We don't build decls for an instantiation of a
14970 variadic capture proxy, we instantiate the elements
14971 when needed. */
14974 }
14975 /* Fall through */
14978 {
14982 /* If the original type was a reference, we'll be wrapped in
14983 the appropriate INDIRECT_REF. */
14986 }
14997 {
15006 }
15009 {
15015 integral_constant_expression_p);
15019 /* If the resulting list of expression statement is empty,
15020 fold it further into void_zero_node. */
15025 }
15028 {
15042 /* For a function scope, we want to use tsubst so that we don't
15043 complain about referring to an auto function before its return
15044 type has been deduced. Otherwise, we want to use tsubst_copy so
15045 that we look up the existing field/parameter/variable rather
15046 than build a new one. */
15051 {
15052 /* Look up the parameter we want directly, as tsubst_copy
15053 doesn't do what we need. */
15059 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15062 }
15063 else
15072 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15074 /* Now that we know visibility, instantiate the type so we have a
15075 declaration of the op() for later calls to lambda_function. */
15081 }
15084 /* We can get here for a constant initializer of non-dependent type.
15085 FIXME stop folding in cp_parser_initializer_clause. */
15086 {
15088 complain);
15090 }
15094 integral_constant_expression_p));
15104 complain));
15107 /* Handle Objective-C++ constructs, if appropriate. */
15108 {
15109 tree subst
15114 }
15116 }
15118 #undef RECUR
15119 #undef RETURN
15120 out:
15123 }
15125 /* Verify that the instantiated ARGS are valid. For type arguments,
15126 make sure that the type's linkage is ok. For non-type arguments,
15127 make sure they are constants if they are integral or enumerations.
15128 Emit an error under control of COMPLAIN, and return TRUE on error. */
15130 static bool
15132 {
15136 {
15146 }
15148 {
15149 /* [basic.link]: A name with no linkage (notably, the name
15150 of a class or enumeration declared in a local scope)
15151 shall not be used to declare an entity with linkage.
15152 This implies that names with no linkage cannot be used as
15153 template arguments
15155 DR 757 relaxes this restriction for C++0x. */
15160 {
15161 /* DR 488 makes use of a type with no linkage cause
15162 type deduction to fail. */
15164 {
15167 else
15170 }
15172 }
15173 /* In order to avoid all sorts of complications, we do not
15174 allow variably-modified types as template arguments. */
15176 {
15180 }
15181 }
15182 /* Class template and alias template arguments should be OK. */
15184 ;
15185 /* A non-type argument of integral or enumerated type must be a
15186 constant. */
15190 {
15194 }
15196 }
15198 static bool
15200 {
15205 {
15208 }
15212 }
15214 /* We're out of SFINAE context now, so generate diagnostics for the access
15215 errors we saw earlier when instantiating D from TMPL and ARGS. */
15217 static void
15219 {
15231 }
15233 /* Instantiate the indicated variable, function, or alias template TMPL with
15234 the template arguments in TARG_PTR. */
15236 static tree
15238 {
15240 tree fndecl;
15241 tree gen_tmpl;
15242 tree spec;
15250 /* If this function is a clone, handle it specially. */
15252 {
15253 tree spec;
15254 tree clone;
15256 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15257 DECL_CLONED_FUNCTION. */
15263 /* Look for the clone. */
15267 /* We should always have found the clone by now. */
15270 }
15275 /* Check to see if we already have this specialization. */
15278 /* The TMPL is a partial instantiation. To get a full set of
15279 arguments we must add the arguments used to perform the
15280 partial instantiation. */
15282 targ_ptr);
15284 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15285 but it doesn't seem to be on the hot path. */
15294 {
15296 {
15300 }
15302 }
15305 complain))
15308 /* We are building a FUNCTION_DECL, during which the access of its
15309 parameters and return types have to be checked. However this
15310 FUNCTION_DECL which is the desired context for access checking
15311 is not built yet. We solve this chicken-and-egg problem by
15312 deferring all checks until we have the FUNCTION_DECL. */
15315 /* Instantiation of the function happens in the context of the function
15316 template, not the context of the overload resolution we're doing. */
15318 /* If there are dependent arguments, e.g. because we're doing partial
15319 ordering, make sure processing_template_decl stays set. */
15323 {
15327 }
15328 /* Substitute template parameters to obtain the specialization. */
15336 {
15339 }
15341 /* The DECL_TI_TEMPLATE should always be the immediate parent
15342 template, not the most general template. */
15345 /* Now we know the specialization, compute access previously
15346 deferred. */
15353 /* If we've just instantiated the main entry point for a function,
15354 instantiate all the alternate entry points as well. We do this
15355 by cloning the instantiation of the main entry point, not by
15356 instantiating the template clones. */
15361 {
15363 {
15364 /* Remember to reinstantiate when we're out of SFINAE so the user
15365 can see the errors. */
15367 }
15369 }
15371 }
15373 /* Wrapper for instantiate_template_1. */
15375 tree
15377 {
15378 tree ret;
15383 }
15385 /* Instantiate the alias template TMPL with ARGS. Also push a template
15386 instantiation level, which instantiate_template doesn't do because
15387 functions and variables have sufficient context established by the
15388 callers. */
15390 static tree
15392 {
15399 {
15402 }
15404 args =
15412 /* We can't free this if a pending_template entry or last_error_tinst_level
15413 is pointing at it. */
15419 }
15421 /* PARM is a template parameter pack for FN. Returns true iff
15422 PARM is used in a deducible way in the argument list of FN. */
15424 static bool
15426 {
15429 {
15431 tree packs;
15437 {
15438 /* The template parameter pack is used in a function parameter
15439 pack. If this is the end of the parameter list, the
15440 template parameter pack is deducible. */
15443 else
15444 /* Otherwise, not. Well, it could be deduced from
15445 a non-pack parameter, but doing so would end up with
15446 a deduction mismatch, so don't bother. */
15448 }
15449 }
15450 /* The template parameter pack isn't used in any function parameter
15451 packs, but it might be used deeper, e.g. tuple<Args...>. */
15453 }
15455 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15456 NARGS elements of the arguments that are being used when calling
15457 it. TARGS is a vector into which the deduced template arguments
15458 are placed.
15460 Returns either a FUNCTION_DECL for the matching specialization of FN or
15461 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15462 true, diagnostics will be printed to explain why it failed.
15464 If FN is a conversion operator, or we are trying to produce a specific
15465 specialization, RETURN_TYPE is the return type desired.
15467 The EXPLICIT_TARGS are explicit template arguments provided via a
15468 template-id.
15470 The parameter STRICT is one of:
15472 DEDUCE_CALL:
15473 We are deducing arguments for a function call, as in
15474 [temp.deduct.call].
15476 DEDUCE_CONV:
15477 We are deducing arguments for a conversion function, as in
15478 [temp.deduct.conv].
15480 DEDUCE_EXACT:
15481 We are deducing arguments when doing an explicit instantiation
15482 as in [temp.explicit], when determining an explicit specialization
15483 as in [temp.expl.spec], or when taking the address of a function
15484 template, as in [temp.deduct.funcaddr]. */
15486 tree
15488 tree explicit_targs,
15489 tree targs,
15492 tree return_type,
15493 unification_kind_t strict,
15497 {
15498 tree parms;
15499 tree fntype;
15507 tree tinst;
15513 /* In C++0x, it's possible to have a function template whose type depends
15514 on itself recursively. This is most obvious with decltype, but can also
15515 occur with enumeration scope (c++/48969). So we need to catch infinite
15516 recursion and reject the substitution at deduction time; this function
15517 will return error_mark_node for any repeated substitution.
15519 This also catches excessive recursion such as when f<N> depends on
15520 f<N-1> across all integers, and returns error_mark_node for all the
15521 substitutions back up to the initial one.
15523 This is, of course, not reentrant. */
15533 {
15534 /* [temp.deduct]
15536 The specified template arguments must match the template
15537 parameters in kind (i.e., type, nontype, template), and there
15538 must not be more arguments than there are parameters;
15539 otherwise type deduction fails.
15541 Nontype arguments must match the types of the corresponding
15542 nontype template parameters, or must be convertible to the
15543 types of the corresponding nontype parameters as specified in
15544 _temp.arg.nontype_, otherwise type deduction fails.
15546 All references in the function type of the function template
15547 to the corresponding template parameters are replaced by the
15548 specified template argument values. If a substitution in a
15549 template parameter or in the function type of the function
15550 template results in an invalid type, type deduction fails. */
15555 /* Adjust any explicit template arguments before entering the
15556 substitution context. */
15557 explicit_targs
15559 complain,
15565 /* Substitute the explicit args into the function type. This is
15566 necessary so that, for instance, explicitly declared function
15567 arguments can match null pointed constants. If we were given
15568 an incomplete set of explicit args, we must not do semantic
15569 processing during substitution as we could create partial
15570 instantiations. */
15572 {
15577 /* Dig out the actual parm. */
15580 {
15583 }
15585 {
15588 }
15591 /* No explicit argument for this template parameter. */
15595 {
15596 /* Mark the argument pack as "incomplete". We could
15597 still deduce more arguments during unification.
15598 We remove this mark in type_unification_real. */
15600 {
15604 }
15606 /* We have some incomplete argument packs. */
15608 }
15609 }
15613 {
15616 }
15619 /* Ignore any access checks; we'll see them again in
15620 instantiate_template and they might have the wrong
15621 access path at this point. */
15633 /* Place the explicitly specified arguments in TARGS. */
15636 }
15638 /* Never do unification on the 'this' parameter. */
15642 {
15651 }
15653 /* We allow incomplete unification without an error message here
15654 because the standard doesn't seem to explicitly prohibit it. Our
15655 callers must be ready to deal with unification failures in any
15656 event. */
15659 /* If we aren't explaining yet, push tinst context so we can see where
15660 any errors (e.g. from class instantiations triggered by instantiation
15661 of default template arguments) come from. If we are explaining, this
15662 context is redundant. */
15664 {
15667 }
15669 /* type_unification_real will pass back any access checks from default
15670 template argument substitution. */
15682 /* Now that we have bindings for all of the template arguments,
15683 ensure that the arguments deduced for the template template
15684 parameters have compatible template parameter lists. We cannot
15685 check this property before we have deduced all template
15686 arguments, because the template parameter types of a template
15687 template parameter might depend on prior template parameters
15688 deduced after the template template parameter. The following
15689 ill-formed example illustrates this issue:
15691 template<typename T, template<T> class C> void f(C<5>, T);
15693 template<int N> struct X {};
15695 void g() {
15696 f(X<5>(), 5l); // error: template argument deduction fails
15697 }
15699 The template parameter list of 'C' depends on the template type
15700 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15701 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15702 time that we deduce 'C'. */
15705 {
15708 }
15710 /* All is well so far. Now, check:
15712 [temp.deduct]
15714 When all template arguments have been deduced, all uses of
15715 template parameters in nondeduced contexts are replaced with
15716 the corresponding deduced argument values. If the
15717 substitution results in an invalid type, as described above,
15718 type deduction fails. */
15721 {
15724 }
15726 /* Also collect access checks from the instantiation. */
15739 /* Now perform any access checks encountered during substitution. */
15746 /* If we're looking for an exact match, check that what we got
15747 is indeed an exact match. It might not be if some template
15748 parameters are used in non-deduced contexts. But don't check
15749 for an exact match if we have dependent template arguments;
15750 in that case we're doing partial ordering, and we already know
15751 that we have two candidates that will provide the actual type. */
15753 {
15757 tree sarg
15763 {
15767 }
15768 }
15772 fail:
15775 {
15777 /* Reset once we're all the way out. */
15779 }
15781 /* We can't free this if a pending_template entry or last_error_tinst_level
15782 is pointing at it. */
15788 }
15790 /* Adjust types before performing type deduction, as described in
15791 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15792 sections are symmetric. PARM is the type of a function parameter
15793 or the return type of the conversion function. ARG is the type of
15794 the argument passed to the call, or the type of the value
15795 initialized with the result of the conversion function.
15796 ARG_EXPR is the original argument expression, which may be null. */
15798 static int
15802 tree arg_expr)
15803 {
15807 {
15812 {
15813 /* Swap PARM and ARG throughout the remainder of this
15814 function; the handling is precisely symmetric since PARM
15815 will initialize ARG rather than vice versa. */
15820 }
15823 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15824 too, but here handle it by stripping the reference from PARM
15825 rather than by adding it to ARG. */
15833 /* Nothing else to do in this case. */
15838 }
15841 {
15842 /* [temp.deduct.call]
15844 If P is not a reference type:
15846 --If A is an array type, the pointer type produced by the
15847 array-to-pointer standard conversion (_conv.array_) is
15848 used in place of A for type deduction; otherwise,
15850 --If A is a function type, the pointer type produced by
15851 the function-to-pointer standard conversion
15852 (_conv.func_) is used in place of A for type deduction;
15853 otherwise,
15855 --If A is a cv-qualified type, the top level
15856 cv-qualifiers of A's type are ignored for type
15857 deduction. */
15862 else
15864 }
15866 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15867 of the form T&&, where T is a template parameter, and the argument
15868 is an lvalue, T is deduced as A& */
15874 /* try_one_overload doesn't provide an arg_expr, but
15875 functions are always lvalues. */
15879 /* [temp.deduct.call]
15881 If P is a cv-qualified type, the top level cv-qualifiers
15882 of P's type are ignored for type deduction. If P is a
15883 reference type, the type referred to by P is used for
15884 type deduction. */
15887 {
15890 }
15892 /* DR 322. For conversion deduction, remove a reference type on parm
15893 too (which has been swapped into ARG). */
15898 }
15900 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15901 template which does contain any deducible template parameters; check if
15902 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15903 unify_one_argument. */
15905 static int
15908 {
15909 tree type;
15913 else
15920 {
15924 }
15926 {
15931 }
15935 else
15937 }
15941 /* Returns true iff the expression EXPR is one from which a template
15942 argument can be deduced. In other words, if it's an undecorated
15943 use of a template non-type parameter. */
15945 static bool
15947 {
15949 }
15951 /* Returns true iff the array domain DOMAIN uses a template parameter in a
15952 deducible way; that is, if it has a max value of <PARM> - 1. */
15954 static bool
15956 {
15965 }
15967 /* Returns true iff the template arguments ARGS use a template parameter
15968 in a deducible way. */
15970 static bool
15972 {
15974 {
15979 else
15980 {
15987 else
15989 }
15992 }
15994 }
15996 /* Returns true iff TYPE contains any deducible references to template
15997 parameters, as per 14.8.2.5. */
15999 static bool
16001 {
16005 /* T
16006 cv-list T
16007 TT<T>
16008 TT<i>
16009 TT<> */
16014 /* T*
16015 T&
16016 T&& */
16020 /* T[integer-constant ]
16021 type [i] */
16026 /* T type ::*
16027 type T::*
16028 T T::*
16029 T (type ::*)()
16030 type (T::*)()
16031 type (type ::*)(T)
16032 type (T::*)(T)
16033 T (type ::*)(T)
16034 T (T::*)()
16035 T (T::*)(T) */
16038 || (uses_deducible_template_parms
16041 /* template-name <T> (where template-name refers to a class template)
16042 template-name <i> (where template-name refers to a class template) */
16049 /* type (T)
16050 T()
16051 T(T) */
16054 {
16063 }
16066 }
16068 /* Subroutine of type_unification_real and unify_pack_expansion to
16069 handle unification of a single P/A pair. Parameters are as
16070 for those functions. */
16072 static int
16076 {
16083 /* We can't deduce anything from this, but we might get all the
16084 template args from other function args. */
16087 /* Implicit conversions (Clause 4) will be performed on a function
16088 argument to convert it to the type of the corresponding function
16089 parameter if the parameter type contains no template-parameters that
16090 participate in template argument deduction. */
16092 /* For function parameters that contain no template-parameters at all,
16093 we have historically checked for convertibility in order to shortcut
16094 consideration of this candidate. */
16096 explain_p);
16099 /* For function parameters with only non-deducible template parameters,
16100 just return. */
16104 {
16106 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16107 | UNIFY_ALLOW_MORE_CV_QUAL
16121 }
16123 /* We only do these transformations if this is the top-level
16124 parameter_type_list in a call or declaration matching; in other
16125 situations (nested function declarators, template argument lists) we
16126 won't be comparing a type to an expression, and we don't do any type
16127 adjustments. */
16129 {
16131 {
16134 {
16135 /* [temp.deduct.type] A template-argument can be
16136 deduced from a pointer to function or pointer
16137 to member function argument if the set of
16138 overloaded functions does not contain function
16139 templates and at most one of a set of
16140 overloaded functions provides a unique
16141 match. */
16148 }
16154 }
16156 arg_strict |=
16158 }
16159 else
16163 /* For deduction from an init-list we need the actual list. */
16167 }
16169 /* Most parms like fn_type_unification.
16171 If SUBR is 1, we're being called recursively (to unify the
16172 arguments of a function or method parameter of a function
16173 template).
16175 CHECKS is a pointer to a vector of access checks encountered while
16176 substituting default template arguments. */
16178 static int
16180 tree targs,
16181 tree xparms,
16185 unification_kind_t strict,
16189 {
16194 tree parms;
16203 /* Reset the number of non-defaulted template arguments contained
16204 in TARGS. */
16207 again:
16215 {
16220 /* For a function parameter pack that occurs at the end of the
16221 parameter-declaration-list, the type A of each remaining
16222 argument of the call is compared with the type P of the
16223 declarator-id of the function parameter pack. */
16229 /* For a function parameter pack that does not occur at the
16230 end of the parameter-declaration-list, the type of the
16231 parameter pack is a non-deduced context. */
16240 }
16245 {
16246 /* Unify the remaining arguments with the pack expansion type. */
16247 tree argvec;
16250 /* Allocate a TREE_VEC and copy in all of the arguments */
16255 /* Copy the parameter into parmvec. */
16261 /* Advance to the end of the list of parameters. */
16263 }
16265 /* Fail if we've reached the end of the parm list, and more args
16266 are present, and the parm list isn't variadic. */
16269 /* Fail if parms are left and they don't have default values. */
16272 {
16276 {
16277 count++;
16279 }
16281 }
16284 {
16285 tsubst_flags_t complain = (explain_p
16286 ? tf_warning_or_error
16290 {
16294 /* Clear the "incomplete" flags on all argument packs now so that
16295 substituting them into later default arguments works. */
16297 {
16300 }
16306 /* If this is an undeduced nontype parameter that depends on
16307 a type parameter, try another pass; its type may have been
16308 deduced from a later argument than the one from which
16309 this parameter can be deduced. */
16315 /* Core issue #226 (C++0x) [temp.deduct]:
16317 If a template argument has not been deduced, its
16318 default template argument, if any, is used.
16320 When we are in C++98 mode, TREE_PURPOSE will either
16321 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16322 to explicitly check cxx_dialect here. */
16324 {
16339 else
16340 {
16342 /* The position of the first default template argument,
16343 is also the number of non-defaulted arguments in TARGS.
16344 Record that. */
16348 }
16349 }
16351 /* If the type parameter is a parameter pack, then it will
16352 be deduced to an empty parameter pack. */
16354 {
16355 tree arg;
16358 {
16362 }
16363 else
16370 }
16373 }
16374 }
16375 #ifdef ENABLE_CHECKING
16378 #endif
16381 }
16383 /* Subroutine of type_unification_real. Args are like the variables
16384 at the call site. ARG is an overloaded function (or template-id);
16385 we try deducing template args from each of the overloads, and if
16386 only one succeeds, we go with that. Modifies TARGS and returns
16387 true on success. */
16389 static bool
16391 tree targs,
16392 tree parm,
16393 tree arg,
16394 unification_kind_t strict,
16397 {
16404 {
16407 }
16408 else
16412 /* Handle `&x' where `x' is some static or non-static member
16413 function name. */
16419 /* Strip baselink information. */
16424 {
16425 /* If we got some explicit template args, we need to plug them into
16426 the affected templates before we try to unify, in case the
16427 explicit args will completely resolve the templates in question. */
16434 {
16447 {
16452 {
16455 }
16456 }
16459 }
16460 /* If no templates (or more than one) are fully resolved by the
16461 explicit arguments, this template-id is a non-deduced context; it
16462 could still be OK if we deduce all template arguments for the
16463 enclosing call through other arguments. */
16466 }
16469 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16470 -- but the deduction does not succeed because the expression is
16471 not just the function on its own. */
16473 else
16479 {
16482 }
16484 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16485 to function or pointer to member function argument if the set of
16486 overloaded functions does not contain function templates and at most
16487 one of a set of overloaded functions provides a unique match.
16489 So if we found multiple possibilities, we return success but don't
16490 deduce anything. */
16493 {
16498 }
16503 }
16505 /* Core DR 115: In contexts where deduction is done and fails, or in
16506 contexts where deduction is not done, if a template argument list is
16507 specified and it, along with any default template arguments, identifies
16508 a single function template specialization, then the template-id is an
16509 lvalue for the function template specialization. */
16511 tree
16513 {
16526 {
16529 }
16531 {
16534 }
16536 {
16539 }
16542 {
16546 /* If we got some explicit template args, we need to plug them into
16547 the affected templates before we try to unify, in case the
16548 explicit args will completely resolve the templates in question. */
16556 {
16569 {
16572 {
16575 }
16577 {
16580 }
16581 }
16582 }
16584 {
16592 {
16593 tree base
16596 }
16600 }
16602 /* There were no good options and at least one bad one, so let the
16603 user know what the problem is. */
16605 }
16607 }
16609 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16610 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16611 different overloads deduce different arguments for a given parm.
16612 ADDR_P is true if the expression for which deduction is being
16613 performed was of the form "& fn" rather than simply "fn".
16615 Returns 1 on success. */
16617 static int
16619 tree orig_targs,
16620 tree targs,
16621 tree parm,
16622 tree arg,
16623 unification_kind_t strict,
16627 {
16629 tree tempargs;
16635 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16636 to function or pointer to member function argument if the set of
16637 overloaded functions does not contain function templates and at most
16638 one of a set of overloaded functions provides a unique match.
16640 So if this is a template, just return success. */
16652 /* We don't copy orig_targs for this because if we have already deduced
16653 some template args from previous args, unify would complain when we
16654 try to deduce a template parameter for the same argument, even though
16655 there isn't really a conflict. */
16662 /* First make sure we didn't deduce anything that conflicts with
16663 explicitly specified args. */
16665 {
16672 /* Since we're unifying against ourselves, we will fill in
16673 template args used in the function parm list with our own
16674 template parms. Discard them. */
16678 }
16681 {
16686 }
16689 }
16691 /* PARM is a template class (perhaps with unbound template
16692 parameters). ARG is a fully instantiated type. If ARG can be
16693 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16694 TARGS are as for unify. */
16696 static tree
16699 {
16700 tree copy_of_targs;
16707 /* We need to make a new template argument vector for the call to
16708 unify. If we used TARGS, we'd clutter it up with the result of
16709 the attempted unification, even if this class didn't work out.
16710 We also don't want to commit ourselves to all the unifications
16711 we've already done, since unification is supposed to be done on
16712 an argument-by-argument basis. In other words, consider the
16713 following pathological case:
16715 template <int I, int J, int K>
16716 struct S {};
16718 template <int I, int J>
16719 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16721 template <int I, int J, int K>
16722 void f(S<I, J, K>, S<I, I, I>);
16724 void g() {
16725 S<0, 0, 0> s0;
16726 S<0, 1, 2> s2;
16728 f(s0, s2);
16729 }
16731 Now, by the time we consider the unification involving `s2', we
16732 already know that we must have `f<0, 0, 0>'. But, even though
16733 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
16734 because there are two ways to unify base classes of S<0, 1, 2>
16735 with S<I, I, I>. If we kept the already deduced knowledge, we
16736 would reject the possibility I=1. */
16739 /* If unification failed, we're done. */
16745 }
16747 /* Given a template type PARM and a class type ARG, find the unique
16748 base type in ARG that is an instance of PARM. We do not examine
16749 ARG itself; only its base-classes. If there is not exactly one
16750 appropriate base class, return NULL_TREE. PARM may be the type of
16751 a partial specialization, as well as a plain template type. Used
16752 by unify. */
16754 static enum template_base_result
16757 {
16759 tree binfo;
16765 {
16766 /* The type could not be completed. */
16769 }
16771 /* Walk in inheritance graph order. The search order is not
16772 important, and this avoids multiple walks of virtual bases. */
16774 {
16779 {
16780 /* If there is more than one satisfactory baseclass, then:
16782 [temp.deduct.call]
16784 If they yield more than one possible deduced A, the type
16785 deduction fails.
16787 applies. */
16789 {
16792 }
16795 }
16796 }
16800 }
16802 /* Returns the level of DECL, which declares a template parameter. */
16804 static int
16806 {
16808 {
16818 }
16820 }
16822 /* Decide whether ARG can be unified with PARM, considering only the
16823 cv-qualifiers of each type, given STRICT as documented for unify.
16824 Returns nonzero iff the unification is OK on that basis. */
16826 static int
16828 {
16834 {
16835 /* Although a CVR qualifier is ignored when being applied to a
16836 substituted template parameter ([8.3.2]/1 for example), that
16837 does not allow us to unify "const T" with "int&" because both
16838 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16839 It is ok when we're allowing additional CV qualifiers
16840 at the outer level [14.8.2.1]/3,1st bullet. */
16850 }
16861 }
16863 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16864 void
16866 {
16870 {
16873 }
16874 else
16875 {
16878 }
16879 }
16881 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16882 do { \
16883 if (unify (TP, TA, P, A, S, EP)) \
16884 return 1; \
16885 } while (0);
16887 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16888 expansion at the end of PACKED_PARMS. Returns 0 if the type
16889 deduction succeeds, 1 otherwise. STRICT is the same as in
16890 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16891 call argument list. We'll need to adjust the arguments to make them
16892 types. SUBR tells us if this is from a recursive call to
16893 type_unification_real, or for comparing two template argument
16894 lists. */
16896 static int
16900 {
16901 tree parm
16911 /* Determine the parameter packs we will be deducing from the
16912 pattern, and record their current deductions. */
16915 {
16919 /* Determine the index and level of this parameter pack. */
16922 /* Keep track of the parameter packs and their corresponding
16923 argument packs. */
16926 }
16928 /* Loop through all of the arguments that have not yet been
16929 unified and unify each with the pattern. */
16931 {
16932 tree parm;
16936 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16937 or the element of its argument pack at the current index if
16938 this argument was explicitly specified. */
16940 {
16949 {
16952 }
16954 }
16956 /* If we had explicit template arguments, substitute them into the
16957 pattern before deduction. */
16959 {
16960 /* Some arguments might still be unspecified or dependent. */
16968 NULL_TREE);
16973 }
16974 else
16977 /* Unify the pattern with the current argument. */
16982 /* For each parameter pack, collect the deduced value. */
16984 {
16990 }
16991 }
16993 /* Verify that the results of unification with the parameter packs
16994 produce results consistent with what we've seen before, and make
16995 the deduced argument packs available. */
16997 {
17004 /* By default keep the original deduced argument pack.
17005 If necessary, more specific code is going to update the
17006 resulting deduced argument later down in this function. */
17010 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17011 actually deduce anything. */
17019 {
17020 /* If we had fewer function args than explicit template args,
17021 just use the explicits. */
17026 }
17029 {
17030 tree result;
17031 /* Build the deduced *_ARGUMENT_PACK. */
17033 {
17038 }
17039 else
17044 /* Note the deduced argument packs for this parameter
17045 pack. */
17047 }
17051 {
17052 /* We only had the explicitly-provided arguments before, but
17053 now we have a complete set of arguments. */
17059 }
17060 else
17061 {
17067 /* Inconsistent unification of this parameter pack. */
17069 bad_old_arg,
17070 bad_new_arg);
17071 }
17072 }
17075 }
17077 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17078 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17079 parameters and return value are as for unify. */
17081 static int
17085 {
17086 tree parm_max;
17087 tree arg_max;
17091 /* Our representation of array types uses "N - 1" as the
17092 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17093 not an integer constant. We cannot unify arbitrarily
17094 complex expressions, so we eliminate the MINUS_EXPRs
17095 here. */
17099 {
17102 }
17106 {
17107 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17108 trying to unify the type of a variable with the type
17109 of a template parameter. For example:
17111 template <unsigned int N>
17112 void f (char (&) [N]);
17113 int g();
17114 void h(int i) {
17115 char a[g(i)];
17116 f(a);
17117 }
17119 Here, the type of the ARG will be "int [g(i)]", and
17120 may be a SAVE_EXPR, etc. */
17124 }
17126 /* If only one of the bounds used a MINUS_EXPR, compensate
17127 by adding one to the other bound. */
17130 integer_type_node,
17131 parm_max,
17132 integer_one_node);
17135 integer_type_node,
17136 arg_max,
17137 integer_one_node);
17141 }
17143 /* Deduce the value of template parameters. TPARMS is the (innermost)
17144 set of template parameters to a template. TARGS is the bindings
17145 for those template parameters, as determined thus far; TARGS may
17146 include template arguments for outer levels of template parameters
17147 as well. PARM is a parameter to a template function, or a
17148 subcomponent of that parameter; ARG is the corresponding argument.
17149 This function attempts to match PARM with ARG in a manner
17150 consistent with the existing assignments in TARGS. If more values
17151 are deduced, then TARGS is updated.
17153 Returns 0 if the type deduction succeeds, 1 otherwise. The
17154 parameter STRICT is a bitwise or of the following flags:
17156 UNIFY_ALLOW_NONE:
17157 Require an exact match between PARM and ARG.
17158 UNIFY_ALLOW_MORE_CV_QUAL:
17159 Allow the deduced ARG to be more cv-qualified (by qualification
17160 conversion) than ARG.
17161 UNIFY_ALLOW_LESS_CV_QUAL:
17162 Allow the deduced ARG to be less cv-qualified than ARG.
17163 UNIFY_ALLOW_DERIVED:
17164 Allow the deduced ARG to be a template base class of ARG,
17165 or a pointer to a template base class of the type pointed to by
17166 ARG.
17167 UNIFY_ALLOW_INTEGER:
17168 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17169 case for more information.
17170 UNIFY_ALLOW_OUTER_LEVEL:
17171 This is the outermost level of a deduction. Used to determine validity
17172 of qualification conversions. A valid qualification conversion must
17173 have const qualified pointers leading up to the inner type which
17174 requires additional CV quals, except at the outer level, where const
17175 is not required [conv.qual]. It would be normal to set this flag in
17176 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17177 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17178 This is the outermost level of a deduction, and PARM can be more CV
17179 qualified at this point.
17180 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17181 This is the outermost level of a deduction, and PARM can be less CV
17182 qualified at this point. */
17184 static int
17187 {
17189 tree targ;
17190 tree tparm;
17193 /* I don't think this will do the right thing with respect to types.
17194 But the only case I've seen it in so far has been array bounds, where
17195 signedness is the only information lost, and I think that will be
17196 okay. */
17204 /* We can't deduce anything from this, but we might get all the
17205 template args from other function args. */
17208 /* If PARM uses template parameters, then we can't bail out here,
17209 even if ARG == PARM, since we won't record unifications for the
17210 template parameters. We might need them if we're trying to
17211 figure out which of two things is more specialized. */
17215 /* Handle init lists early, so the rest of the function can assume
17216 we're dealing with a type. */
17218 {
17223 /* Replace T with std::initializer_list<T> for deduction. */
17230 /* We can only deduce from an initializer list argument if the
17231 parameter is std::initializer_list or an array; otherwise this
17232 is a non-deduced context. */
17237 else
17241 {
17248 {
17250 /* It should only be possible to get here for a call. */
17252 elt_strict |= maybe_adjust_types_for_deduction
17255 }
17258 explain_p);
17259 }
17262 {
17263 /* Also deduce from the length of the initializer list. */
17269 }
17271 /* If the std::initializer_list<T> deduction worked, replace the
17272 deduced A with std::initializer_list<A>. */
17274 {
17279 }
17281 }
17283 /* Immediately reject some pairs that won't unify because of
17284 cv-qualification mismatches. */
17287 /* It is the elements of the array which hold the cv quals of an array
17288 type, and the elements might be template type parms. We'll check
17289 when we recurse. */
17291 /* We check the cv-qualifiers when unifying with template type
17292 parameters below. We want to allow ARG `const T' to unify with
17293 PARM `T' for example, when computing which of two templates
17294 is more specialized, for example. */
17308 {
17312 /* In a type which contains a nested-name-specifier, template
17313 argument values cannot be deduced for template parameters used
17314 within the nested-name-specifier. */
17326 /* The PARM is not one we're trying to unify. Just check
17327 to see if it matches ARG. */
17328 {
17333 else
17335 }
17342 /* Check for mixed types and values. */
17350 {
17351 /* ARG must be constructed from a template class or a template
17352 template parameter. */
17357 {
17361 tree parm_parms
17362 = DECL_INNERMOST_TEMPLATE_PARMS
17367 /* The resolution to DR150 makes clear that default
17368 arguments for an N-argument may not be used to bind T
17369 to a template template parameter with fewer than N
17370 parameters. It is not safe to permit the binding of
17371 default arguments as an extension, as that may change
17372 the meaning of a conforming program. Consider:
17374 struct Dense { static const unsigned int dim = 1; };
17376 template <template <typename> class View,
17377 typename Block>
17378 void operator+(float, View<Block> const&);
17380 template <typename Block,
17381 unsigned int Dim = Block::dim>
17382 struct Lvalue_proxy { operator float() const; };
17384 void
17385 test_1d (void) {
17386 Lvalue_proxy<Dense> p;
17387 float b;
17388 b + p;
17389 }
17391 Here, if Lvalue_proxy is permitted to bind to View, then
17392 the global operator+ will be used; if they are not, the
17393 Lvalue_proxy will be converted to float. */
17395 full_argvec,
17397 (explain_p
17398 ? tf_warning_or_error
17405 /* Deduce arguments T, i from TT<T> or TT<i>.
17406 We check each element of PARMVEC and ARGVEC individually
17407 rather than the whole TREE_VEC since they can have
17408 different number of elements. */
17415 /* Check if the parameters end in a pack, making them
17416 variadic. */
17422 /* If the template argument list of P contains a pack
17423 expansion that is not the last template argument, the
17424 entire template argument list is a non-deduced
17425 context. */
17434 {
17439 }
17444 DEDUCE_EXACT,
17447 }
17450 /* Fall through to deduce template name. */
17451 }
17455 {
17456 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17458 /* Simple cases: Value already set, does match or doesn't. */
17463 }
17464 else
17465 {
17466 /* If PARM is `const T' and ARG is only `int', we don't have
17467 a match unless we are allowing additional qualification.
17468 If ARG is `const int' and PARM is just `T' that's OK;
17469 that binds `const int' to `T'. */
17474 /* Consider the case where ARG is `const volatile int' and
17475 PARM is `const T'. Then, T should be `volatile int'. */
17476 arg = cp_build_qualified_type_real
17481 /* Simple cases: Value already set, does match or doesn't. */
17487 /* Make sure that ARG is not a variable-sized array. (Note
17488 that were talking about variable-sized arrays (like
17489 `int[n]'), rather than arrays of unknown size (like
17490 `int[]').) We'll get very confused by such a type since
17491 the bound of the array is not constant, and therefore
17492 not mangleable. Besides, such types are not allowed in
17493 ISO C++, so we can do as we please here. We do allow
17494 them for 'auto' deduction, since that isn't ABI-exposed. */
17498 /* Strip typedefs as in convert_template_argument. */
17500 }
17502 /* If ARG is a parameter pack or an expansion, we cannot unify
17503 against it unless PARM is also a parameter pack. */
17508 /* If the argument deduction results is a METHOD_TYPE,
17509 then there is a problem.
17510 METHOD_TYPE doesn't map to any real C++ type the result of
17511 the deduction can not be of that type. */
17525 {
17526 /* The PARM is not one we're trying to unify. Just check
17527 to see if it matches ARG. */
17533 }
17539 {
17544 }
17546 /* [temp.deduct.type] If, in the declaration of a function template
17547 with a non-type template-parameter, the non-type
17548 template-parameter is used in an expression in the function
17549 parameter-list and, if the corresponding template-argument is
17550 deduced, the template-argument type shall match the type of the
17551 template-parameter exactly, except that a template-argument
17552 deduced from an array bound may be of any integral type.
17553 The non-type parameter might use already deduced type parameters. */
17556 /* Template-parameter dependent expression. Just accept it for now.
17557 It will later be processed in convert_template_argument. */
17558 ;
17563 /* Convert the ARG to the type of PARM; the deduced non-type
17564 template argument must exactly match the types of the
17565 corresponding parameter. */
17568 /* We haven't deduced the type of this parameter yet. Try again
17569 later. */
17571 else
17574 /* If ARG is a parameter pack or an expansion, we cannot unify
17575 against it unless PARM is also a parameter pack. */
17585 {
17586 /* A pointer-to-member constant can be unified only with
17587 another constant. */
17591 /* Just unify the class member. It would be useless (and possibly
17592 wrong, depending on the strict flags) to unify also
17593 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17594 arg refer to the same variable, even if through different
17595 classes. For instance:
17597 struct A { int x; };
17598 struct B : A { };
17600 Unification of &A::x and &B::x must succeed. */
17603 }
17606 {
17610 /* [temp.deduct.call]
17612 A can be another pointer or pointer to member type that can
17613 be converted to the deduced A via a qualification
17614 conversion (_conv.qual_).
17616 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17617 This will allow for additional cv-qualification of the
17618 pointed-to types if appropriate. */
17621 /* The derived-to-base conversion only persists through one
17622 level of pointers. */
17627 }
17659 /* We have already checked cv-qualification at the top of the
17660 function. */
17664 /* As far as unification is concerned, this wins. Later checks
17665 will invalidate it if necessary. */
17668 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17669 /* Type INTEGER_CST can come from ordinary constant template args. */
17681 {
17691 /* Check for pack expansions in the parameters. */
17693 {
17695 {
17697 /* We can unify against something with a trailing
17698 parameter pack. */
17700 else
17701 /* [temp.deduct.type]/9: If the template argument list of
17702 P contains a pack expansion that is not the last
17703 template argument, the entire template argument list
17704 is a non-deduced context. */
17706 }
17707 }
17709 /* If we don't have enough arguments to satisfy the parameters
17710 (not counting the pack expression at the end), or we have
17711 too many arguments for a parameter list that doesn't end in
17712 a pack expression, we can't unify. */
17718 /* Unify all of the parameters that precede the (optional)
17719 pack expression. */
17721 {
17726 }
17729 DEDUCE_EXACT,
17732 }
17740 {
17748 }
17751 {
17755 {
17756 /* First, we try to unify the PARM and ARG directly. */
17761 {
17762 /* Fallback to the special case allowed in
17763 [temp.deduct.call]:
17765 If P is a class, and P has the form
17766 template-id, then A can be a derived class of
17767 the deduced A. Likewise, if P is a pointer to
17768 a class of the form template-id, A can be a
17769 pointer to a derived class pointed to by the
17770 deduced A. */
17777 }
17778 }
17782 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17783 Then, we should unify `int' and `U'. */
17785 else
17786 /* There's no chance of unification succeeding. */
17791 }
17798 {
17801 tree a;
17807 /* CV qualifications for methods can never be deduced, they must
17808 match exactly. We need to check them explicitly here,
17809 because type_unification_real treats them as any other
17810 cv-qualified parameter. */
17812 && (!check_cv_quals_for_unify
17832 }
17835 /* Unify a pointer to member with a pointer to member function, which
17836 deduces the type of the member as a function type. */
17838 {
17839 /* Check top-level cv qualifiers */
17847 /* Determine the type of the function we are unifying against. */
17851 }
17870 /* Matched cases are handled by the ARG == PARM test above. */
17874 /* A non-type template parameter that is a variable should be a
17875 an integral constant, in which case, it whould have been
17876 folded into its (constant) value. So we should not be getting
17877 a variable here. */
17888 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17889 or UNDERLYING_TYPE nodes. */
17893 /* Unification fails if we hit an error node. */
17897 /* An unresolved overload is a nondeduced context. */
17902 /* We must be looking at an expression. This can happen with
17903 something like:
17905 template <int I>
17906 void foo(S<I>, S<I + 2>);
17908 This is a "nondeduced context":
17910 [deduct.type]
17912 The nondeduced contexts are:
17914 --A type that is a template-id in which one or more of
17915 the template-arguments is an expression that references
17916 a template-parameter.
17918 In these cases, we assume deduction succeeded, but don't
17919 actually infer any unifications. */
17924 else
17926 }
17927 }
17928 #undef RECUR_AND_CHECK_FAILURE
17929 \f
17930 /* Note that DECL can be defined in this translation unit, if
17931 required. */
17933 static void
17935 {
17936 tree clone;
17940 }
17942 /* Called if RESULT is explicitly instantiated, or is a member of an
17943 explicitly instantiated class. */
17945 void
17947 {
17950 /* If this entity has already been written out, it's too late to
17951 make any modifications. */
17955 /* For anonymous namespace we don't need to do anything. */
17957 {
17960 }
17963 /* The TREE_PUBLIC flag for function declarations will have been
17964 set correctly by tsubst. */
17967 /* This might have been set by an earlier implicit instantiation. */
17972 else
17973 {
17976 /* Always make artificials weak. */
17979 /* For WIN32 we also want to put explicit instantiations in
17980 linkonce sections. */
17983 }
17985 /* If EXTERN_P, then this function will not be emitted -- unless
17986 followed by an explicit instantiation, at which point its linkage
17987 will be adjusted. If !EXTERN_P, then this function will be
17988 emitted here. In neither circumstance do we want
17989 import_export_decl to adjust the linkage. */
17991 }
17993 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17994 important template arguments. If any are missing, we check whether
17995 they're important by using error_mark_node for substituting into any
17996 args that were used for partial ordering (the ones between ARGS and END)
17997 and seeing if it bubbles up. */
17999 static bool
18001 {
18006 {
18009 }
18011 {
18015 }
18017 }
18019 /* Given two function templates PAT1 and PAT2, return:
18021 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18022 -1 if PAT2 is more specialized than PAT1.
18023 0 if neither is more specialized.
18025 LEN indicates the number of parameters we should consider
18026 (defaulted parameters should not be considered).
18028 The 1998 std underspecified function template partial ordering, and
18029 DR214 addresses the issue. We take pairs of arguments, one from
18030 each of the templates, and deduce them against each other. One of
18031 the templates will be more specialized if all the *other*
18032 template's arguments deduce against its arguments and at least one
18033 of its arguments *does* *not* deduce against the other template's
18034 corresponding argument. Deduction is done as for class templates.
18035 The arguments used in deduction have reference and top level cv
18036 qualifiers removed. Iff both arguments were originally reference
18037 types *and* deduction succeeds in both directions, an lvalue reference
18038 wins against an rvalue reference and otherwise the template
18039 with the more cv-qualified argument wins for that pairing (if
18040 neither is more cv-qualified, they both are equal). Unlike regular
18041 deduction, after all the arguments have been deduced in this way,
18042 we do *not* verify the deduced template argument values can be
18043 substituted into non-deduced contexts.
18045 The logic can be a bit confusing here, because we look at deduce1 and
18046 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18047 can find template arguments for pat1 to make arg1 look like arg2, that
18048 means that arg2 is at least as specialized as arg1. */
18050 int
18052 {
18065 /* Remove the this parameter from non-static member functions. If
18066 one is a non-static member function and the other is not a static
18067 member function, remove the first parameter from that function
18068 also. This situation occurs for operator functions where we
18069 locate both a member function (with this pointer) and non-member
18070 operator (with explicit first operand). */
18072 {
18077 }
18079 {
18082 {
18083 len--;
18085 }
18086 }
18088 /* If only one is a conversion operator, they are unordered. */
18092 /* Consider the return type for a conversion function */
18094 {
18097 len++;
18098 }
18100 processing_template_decl++;
18106 /* Stop when an ellipsis is seen. */
18108 {
18119 {
18120 /* When both arguments are pack expansions, we need only
18121 unify the patterns themselves. */
18125 /* This is the last comparison we need to do. */
18127 }
18130 {
18134 }
18137 {
18141 }
18147 {
18153 /* Setup the parameter vector, which contains only ARG1. */
18156 /* Setup the argument vector, which contains the remaining
18157 arguments. */
18166 /* We cannot deduce in the other direction, because ARG1 is
18167 a pack expansion but ARG2 is not. */
18169 }
18171 {
18177 /* Setup the parameter vector, which contains only ARG1. */
18180 /* Setup the argument vector, which contains the remaining
18181 arguments. */
18190 /* We cannot deduce in the other direction, because ARG2 is
18191 a pack expansion but ARG1 is not.*/
18193 }
18195 else
18196 {
18197 /* The normal case, where neither argument is a pack
18198 expansion. */
18205 }
18207 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18208 arg2, then arg2 is not as specialized as arg1. */
18214 /* "If, for a given type, deduction succeeds in both directions
18215 (i.e., the types are identical after the transformations above)
18216 and both P and A were reference types (before being replaced with
18217 the type referred to above):
18218 - if the type from the argument template was an lvalue reference and
18219 the type from the parameter template was not, the argument type is
18220 considered to be more specialized than the other; otherwise,
18221 - if the type from the argument template is more cv-qualified
18222 than the type from the parameter template (as described above),
18223 the argument type is considered to be more specialized than the other;
18224 otherwise,
18225 - neither type is more specialized than the other." */
18228 {
18230 {
18233 else
18235 }
18237 {
18242 }
18243 }
18246 /* We've failed to deduce something in either direction.
18247 These must be unordered. */
18252 /* We have already processed all of the arguments in our
18253 handing of the pack expansion type. */
18258 }
18260 /* "In most cases, all template parameters must have values in order for
18261 deduction to succeed, but for partial ordering purposes a template
18262 parameter may remain without a value provided it is not used in the
18263 types being used for partial ordering."
18265 Thus, if we are missing any of the targs1 we need to substitute into
18266 origs1, then pat2 is not as specialized as pat1. This can happen when
18267 there is a nondeduced context. */
18273 processing_template_decl--;
18275 /* All things being equal, if the next argument is a pack expansion
18276 for one function but not for the other, prefer the
18277 non-variadic function. FIXME this is bogus; see c++/41958. */
18281 {
18284 }
18290 else
18292 }
18294 /* Determine which of two partial specializations of TMPL is more
18295 specialized.
18297 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18298 to the first partial specialization. The TREE_VALUE is the
18299 innermost set of template parameters for the partial
18300 specialization. PAT2 is similar, but for the second template.
18302 Return 1 if the first partial specialization is more specialized;
18303 -1 if the second is more specialized; 0 if neither is more
18304 specialized.
18306 See [temp.class.order] for information about determining which of
18307 two templates is more specialized. */
18309 static int
18311 {
18312 tree targs;
18320 /* Just like what happens for functions, if we are ordering between
18321 different class template specializations, we may encounter dependent
18322 types in the arguments, and we need our dependency check functions
18323 to behave correctly. */
18329 {
18332 }
18338 {
18341 }
18344 /* In the case of a tie where at least one of the class templates
18345 has a parameter pack at the end, the template with the most
18346 non-packed parameters wins. */
18348 && any_deductions
18351 {
18357 /* We don't count the pack expansion at the end. */
18367 }
18370 }
18372 /* Return the template arguments that will produce the function signature
18373 DECL from the function template FN, with the explicit template
18374 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18375 also match. Return NULL_TREE if no satisfactory arguments could be
18376 found. */
18378 static tree
18380 {
18384 tree decl_arg_types;
18387 tree arg;
18391 /* Never do unification on the 'this' parameter. */
18412 }
18414 /* Return the innermost template arguments that, when applied to a partial
18415 specialization of TMPL whose innermost template parameters are
18416 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18417 ARGS.
18419 For example, suppose we have:
18421 template <class T, class U> struct S {};
18422 template <class T> struct S<T*, int> {};
18424 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18425 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18426 int}. The resulting vector will be {double}, indicating that `T'
18427 is bound to `double'. */
18429 static tree
18431 {
18433 tree deduced_args;
18434 tree innermost_deduced_args;
18438 {
18442 innermost_deduced_args);
18443 }
18444 else
18457 /* Verify that nondeduced template arguments agree with the type
18458 obtained from argument deduction.
18460 For example:
18462 struct A { typedef int X; };
18463 template <class T, class U> struct C {};
18464 template <class T> struct C<T, typename T::X> {};
18466 Then with the instantiation `C<A, int>', we can deduce that
18467 `T' is `A' but unify () does not check whether `typename T::X'
18468 is `int'. */
18474 /* We only need to check the innermost arguments; the other
18475 arguments will always agree. */
18480 /* Now that we have bindings for all of the template arguments,
18481 ensure that the arguments deduced for the template template
18482 parameters have compatible template parameter lists. See the use
18483 of template_template_parm_bindings_ok_p in fn_type_unification
18484 for more information. */
18489 }
18491 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18492 Return the TREE_LIST node with the most specialized template, if
18493 any. If there is no most specialized template, the error_mark_node
18494 is returned.
18496 Note that this function does not look at, or modify, the
18497 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18498 returned is one of the elements of INSTANTIATIONS, callers may
18499 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18500 and retrieve it from the value returned. */
18502 tree
18504 {
18511 {
18517 fate--;
18522 fate++;
18527 {
18528 /* Equally specialized, move to next function. If there
18529 is no next function, nothing's most specialized. */
18534 }
18535 }
18538 /* Now verify that champ is better than everything earlier in the
18539 instantiation list. */
18547 {
18550 }
18552 processing_template_decl--;
18558 }
18560 /* If DECL is a specialization of some template, return the most
18561 general such template. Otherwise, returns NULL_TREE.
18563 For example, given:
18565 template <class T> struct S { template <class U> void f(U); };
18567 if TMPL is `template <class U> void S<int>::f(U)' this will return
18568 the full template. This function will not trace past partial
18569 specializations, however. For example, given in addition:
18571 template <class T> struct S<T*> { template <class U> void f(U); };
18573 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18574 `template <class T> template <class U> S<T*>::f(U)'. */
18576 tree
18578 {
18579 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
18580 an immediate specialization. */
18582 {
18586 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
18587 template friend. */
18592 }
18594 /* Look for more and more general templates. */
18596 {
18597 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18598 (See cp-tree.h for details.) */
18606 /* Stop if we run into an explicitly specialized class template. */
18613 }
18616 }
18618 /* Return the most specialized of the class template partial
18619 specializations which can produce TYPE, a specialization of some class
18620 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18621 a _TYPE node corresponding to the partial specialization, while the
18622 TREE_PURPOSE is the set of template arguments that must be
18623 substituted into the TREE_TYPE in order to generate TYPE.
18625 If the choice of partial specialization is ambiguous, a diagnostic
18626 is issued, and the error_mark_node is returned. If there are no
18627 partial specializations matching TYPE, then NULL_TREE is
18628 returned, indicating that the primary template should be used. */
18630 static tree
18632 {
18634 tree t;
18635 tree champ;
18644 /* For determining which partial specialization to use, only the
18645 innermost args are interesting. */
18647 {
18650 }
18653 {
18654 tree partial_spec_args;
18655 tree spec_args;
18664 {
18665 /* Discard the outer levels of args, and then substitute in the
18666 template args from the enclosing class. */
18668 partial_spec_args = tsubst_template_args
18671 /* And the same for the partial specialization TEMPLATE_DECL. */
18673 }
18675 partial_spec_args =
18677 partial_spec_args,
18691 partial_spec_args,
18692 args);
18694 {
18699 }
18700 }
18710 {
18713 ;
18714 else
18715 {
18717 {
18720 {
18723 }
18724 }
18726 }
18727 }
18731 {
18734 {
18737 }
18738 }
18741 {
18749 {
18752 }
18755 }
18758 }
18760 /* Explicitly instantiate DECL. */
18762 void
18764 {
18769 /* An error occurred, for which grokdeclarator has already issued
18770 an appropriate message. */
18773 {
18776 }
18778 {
18779 /* There is an asymmetry here in the way VAR_DECLs and
18780 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18781 the latter, the DECL we get back will be marked as a
18782 template instantiation, and the appropriate
18783 DECL_TEMPLATE_INFO will be set up. This does not happen for
18784 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18785 should handle VAR_DECLs as it currently handles
18786 FUNCTION_DECLs. */
18788 {
18791 }
18794 {
18797 }
18799 {
18804 }
18805 }
18807 {
18810 }
18811 else
18814 /* Check for various error cases. Note that if the explicit
18815 instantiation is valid the RESULT will currently be marked as an
18816 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18817 until we get here. */
18820 {
18821 /* DR 259 [temp.spec].
18823 Both an explicit instantiation and a declaration of an explicit
18824 specialization shall not appear in a program unless the explicit
18825 instantiation follows a declaration of the explicit specialization.
18827 For a given set of template parameters, if an explicit
18828 instantiation of a template appears after a declaration of an
18829 explicit specialization for that template, the explicit
18830 instantiation has no effect. */
18832 }
18834 {
18835 /* [temp.spec]
18837 No program shall explicitly instantiate any template more
18838 than once.
18840 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18841 the first instantiation was `extern' and the second is not,
18842 and EXTERN_P for the opposite case. */
18845 /* If an "extern" explicit instantiation follows an ordinary
18846 explicit instantiation, the template is instantiated. */
18849 }
18851 {
18854 }
18856 {
18859 }
18862 ;
18864 {
18867 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18870 }
18871 else
18879 }
18881 static void
18883 {
18889 {
18892 }
18893 }
18895 /* Called from do_type_instantiation through binding_table_foreach to
18896 do recursive instantiation for the type bound in ENTRY. */
18897 static void
18899 {
18905 }
18907 /* Called from do_type_instantiation to instantiate a member
18908 (a member function or a static member variable) of an
18909 explicitly instantiated class template. */
18910 static void
18912 {
18917 }
18919 /* Perform an explicit instantiation of template class T. STORAGE, if
18920 non-null, is the RID for extern, inline or static. COMPLAIN is
18921 nonzero if this is called from the parser, zero if called recursively,
18922 since the standard is unclear (as detailed below). */
18924 void
18926 {
18936 {
18937 tree tmpl =
18941 else
18944 }
18949 {
18952 t);
18954 }
18957 {
18959 {
18961 {
18964 "ISO C++ 1998 forbids the use of %<extern%> on "
18966 }
18967 else
18969 "ISO C++ forbids the use of %qE"
18971 }
18979 else
18980 {
18982 storage);
18984 }
18985 }
18988 {
18989 /* DR 259 [temp.spec].
18991 Both an explicit instantiation and a declaration of an explicit
18992 specialization shall not appear in a program unless the explicit
18993 instantiation follows a declaration of the explicit specialization.
18995 For a given set of template parameters, if an explicit
18996 instantiation of a template appears after a declaration of an
18997 explicit specialization for that template, the explicit
18998 instantiation has no effect. */
19000 }
19002 {
19003 /* [temp.spec]
19005 No program shall explicitly instantiate any template more
19006 than once.
19008 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19009 instantiation was `extern'. If EXTERN_P then the second is.
19010 These cases are OK. */
19017 /* If we've already instantiated the template, just return now. */
19020 }
19028 {
19029 tree tmp;
19031 /* In contrast to implicit instantiation, where only the
19032 declarations, and not the definitions, of members are
19033 instantiated, we have here:
19035 [temp.explicit]
19037 The explicit instantiation of a class template specialization
19038 implies the instantiation of all of its members not
19039 previously explicitly specialized in the translation unit
19040 containing the explicit instantiation.
19042 Of course, we can't instantiate member template classes, since
19043 we don't have any arguments for them. Note that the standard
19044 is unclear on whether the instantiation of the members are
19045 *explicit* instantiations or not. However, the most natural
19046 interpretation is that it should be an explicit instantiation. */
19061 }
19062 }
19064 /* Given a function DECL, which is a specialization of TMPL, modify
19065 DECL to be a re-instantiation of TMPL with the same template
19066 arguments. TMPL should be the template into which tsubst'ing
19067 should occur for DECL, not the most general template.
19069 One reason for doing this is a scenario like this:
19071 template <class T>
19072 void f(const T&, int i);
19074 void g() { f(3, 7); }
19076 template <class T>
19077 void f(const T& t, const int i) { }
19079 Note that when the template is first instantiated, with
19080 instantiate_template, the resulting DECL will have no name for the
19081 first parameter, and the wrong type for the second. So, when we go
19082 to instantiate the DECL, we regenerate it. */
19084 static void
19086 {
19087 /* The arguments used to instantiate DECL, from the most general
19088 template. */
19089 tree args;
19090 tree code_pattern;
19095 /* Make sure that we can see identifiers, and compute access
19096 correctly. */
19100 {
19101 tree decl_parm;
19102 tree pattern_parm;
19103 tree specs;
19117 specs);
19119 /* Merge parameter declarations. */
19122 pattern_parm
19126 {
19127 tree parm_type;
19128 tree attributes;
19133 NULL_TREE);
19139 {
19142 }
19145 }
19146 /* Merge any parameters that match with the function parameter
19147 pack. */
19149 {
19151 tree expanded_types;
19152 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19153 the parameters in this function parameter pack. */
19158 {
19159 tree parm_type;
19160 tree attributes;
19163 /* Rename the parameter to include the index. */
19172 {
19175 }
19177 }
19178 }
19179 /* Merge additional specifiers from the CODE_PATTERN. */
19183 }
19185 {
19193 }
19194 else
19198 }
19200 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19201 substituted to get DECL. */
19203 tree
19205 {
19208 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19209 for the instantiation. This is not always the most general
19210 template. Consider, for example:
19212 template <class T>
19213 struct S { template <class U> void f();
19214 template <> void f<int>(); };
19216 and an instantiation of S<double>::f<int>. We want TD to be the
19217 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19219 more general template. */
19221 /* We must also deal with friend templates. Given:
19223 template <class T> struct S {
19224 template <class U> friend void f() {};
19225 };
19227 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19228 so far as the language is concerned, but that's still
19229 where we get the pattern for the instantiation from. On
19230 other hand, if the definition comes outside the class, say:
19232 template <class T> struct S {
19233 template <class U> friend void f();
19234 };
19235 template <class U> friend void f() {}
19237 we don't need to look any further. That's what the check for
19238 DECL_INITIAL is for. */
19242 {
19243 /* The present template, TD, should not be a definition. If it
19244 were a definition, we should be using it! Note that we
19245 cannot restructure the loop to just keep going until we find
19246 a template with a definition, since that might go too far if
19247 a specialization was declared, but not defined. */
19251 /* Fetch the more general template. */
19253 }
19256 }
19258 /* Returns true if we need to instantiate this template instance even if we
19259 know we aren't going to emit it.. */
19261 bool
19263 {
19264 /* We always instantiate inline functions so that we can inline them. An
19265 explicit instantiation declaration prohibits implicit instantiation of
19266 non-inline functions. With high levels of optimization, we would
19267 normally inline non-inline functions -- but we're not allowed to do
19268 that for "extern template" functions. Therefore, we check
19269 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19273 /* And we need to instantiate static data members so that
19274 their initializers are available in integral constant
19275 expressions. */
19278 }
19280 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19281 instantiate it now, modifying TREE_TYPE (fn). */
19283 void
19285 {
19288 /* Don't instantiate a noexcept-specification from template context. */
19303 {
19305 {
19320 }
19321 else
19323 }
19324 else
19325 {
19326 /* This is an implicitly declared function, so NOEX is a list of
19327 other functions to evaluate and merge. */
19328 tree elt;
19331 {
19333 tree subspec;
19337 }
19338 }
19343 {
19346 else
19348 }
19349 }
19351 /* Produce the definition of D, a _DECL generated from a template. If
19352 DEFER_OK is nonzero, then we don't have to actually do the
19353 instantiation now; we just have to do it sometime. Normally it is
19354 an error if this is an explicit instantiation but D is undefined.
19355 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19356 explicitly instantiated class template. */
19358 tree
19361 {
19363 tree gen_args;
19364 tree args;
19365 tree td;
19366 tree code_pattern;
19367 tree spec;
19368 tree gen_tmpl;
19374 tree fn_context;
19377 /* This function should only be used to instantiate templates for
19378 functions and static member variables. */
19381 /* Variables are never deferred; if instantiation is required, they
19382 are instantiated right away. That allows for better code in the
19383 case that an expression refers to the value of the variable --
19384 if the variable has a constant value the referring expression can
19385 take advantage of that fact. */
19390 /* Don't instantiate cloned functions. Instead, instantiate the
19391 functions they cloned. */
19399 /* D has already been instantiated or explicitly specialized, so
19400 there's nothing for us to do here.
19402 It might seem reasonable to check whether or not D is an explicit
19403 instantiation, and, if so, stop here. But when an explicit
19404 instantiation is deferred until the end of the compilation,
19405 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19406 the instantiation. */
19409 /* Check to see whether we know that this template will be
19410 instantiated in some other file, as with "extern template"
19411 extension. */
19414 /* In general, we do not instantiate such templates. */
19422 /* We should already have the extra args. */
19425 /* And what's in the hash table should match D. */
19429 /* This needs to happen before any tsubsting. */
19435 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19436 for the instantiation. */
19440 /* We should never be trying to instantiate a member of a class
19441 template or partial specialization. */
19446 /* In the case of a friend template whose definition is provided
19447 outside the class, we may have too many arguments. Drop the
19448 ones we don't need. The same is true for specializations. */
19449 args = get_innermost_template_args
19451 else
19457 else
19460 /* We may be in the middle of deferred access check. Disable it now. */
19463 /* Unless an explicit instantiation directive has already determined
19464 the linkage of D, remember that a definition is available for
19465 this entity. */
19475 /* If D is a member of an explicitly instantiated class template,
19476 and no definition is available, treat it like an implicit
19477 instantiation. */
19480 {
19481 /* Leave linkage flags alone on instantiations with anonymous
19482 visibility. */
19484 {
19487 }
19489 }
19494 /* Defer all other templates, unless we have been explicitly
19495 forbidden from doing so. */
19497 template. */
19498 ! pattern_defined
19499 /* If it's OK to postpone instantiation, do so. */
19500 || defer_ok
19501 /* If this is a static data member that will be defined
19502 elsewhere, we don't want to instantiate the entire data
19503 member, but we do want to instantiate the initializer so that
19504 we can substitute that elsewhere. */
19506 {
19507 /* The definition of the static data member is now required so
19508 we must substitute the initializer. */
19512 {
19513 tree ns;
19514 tree init;
19521 args,
19524 /* Make sure the initializer is still constant, in case of
19525 circular dependency (template/instantiate6.C). */
19526 const_init
19530 LOOKUP_ONLYCONVERTING);
19533 }
19535 /* We restore the source position here because it's used by
19536 add_pending_template. */
19542 /* [temp.explicit]
19544 The definition of a non-exported function template, a
19545 non-exported member function template, or a non-exported
19546 member function or static data member of a class template
19547 shall be present in every translation unit in which it is
19548 explicitly instantiated. */
19552 /* If we're in unevaluated context, we just wanted to get the
19553 constant value; this isn't an odr use, so don't queue
19554 a full instantiation. */
19557 /* ??? Historically, we have instantiated inline functions, even
19558 when marked as "extern template". */
19562 }
19563 /* Tell the repository that D is available in this translation unit
19564 -- and see if it is supposed to be instantiated here. */
19566 {
19567 /* In a PCH file, despite the fact that the repository hasn't
19568 requested instantiation in the PCH it is still possible that
19569 an instantiation will be required in a file that includes the
19570 PCH. */
19573 /* Instantiate inline functions so that the inliner can do its
19574 job, even though we'll not be emitting a copy of this
19575 function. */
19578 }
19584 else
19585 {
19590 }
19592 /* Mark D as instantiated so that recursive calls to
19593 instantiate_decl do not try to instantiate it again. */
19596 /* Regenerate the declaration in case the template has been modified
19597 by a subsequent redeclaration. */
19600 /* We already set the file and line above. Reset them now in case
19601 they changed as a result of calling regenerate_decl_from_template. */
19605 {
19606 tree init;
19609 /* Clear out DECL_RTL; whatever was there before may not be right
19610 since we've reset the type of the declaration. */
19614 /* The initializer is placed in DECL_INITIAL by
19615 regenerate_decl_from_template so we don't need to
19616 push/pop_access_scope again here. Pull it out so that
19617 cp_finish_decl can process it. */
19622 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19623 initializer. That function will defer actual emission until
19624 we have a chance to determine linkage. */
19627 /* Enter the scope of D so that access-checking works correctly. */
19632 }
19636 {
19638 tree subst_decl;
19639 tree tmpl_parm;
19640 tree spec_parm;
19643 /* Save away the current list, in case we are instantiating one
19644 template from within the body of another. */
19647 /* Set up the list of local specializations. */
19650 /* Set up context. */
19654 else
19657 /* Some typedefs referenced from within the template code need to be
19658 access checked at template instantiation time, i.e now. These
19659 types were added to the template at parsing time. Let's get those
19660 and perform the access checks then. */
19662 gen_args);
19664 /* Create substitution entries for the parameters. */
19669 {
19673 }
19675 {
19677 {
19680 }
19681 else
19682 {
19683 /* Register the (value) argument pack as a specialization of
19684 TMPL_PARM, then move on. */
19687 }
19688 }
19691 /* Substitute into the body of the function. */
19695 else
19696 {
19701 /* Set the current input_location to the end of the function
19702 so that finish_function knows where we are. */
19703 input_location
19706 /* Remember if we saw an infinite loop in the template. */
19707 current_function_infinite_loop
19709 }
19711 /* We don't need the local specializations any more. */
19715 /* Finish the function. */
19719 else
19720 {
19723 }
19727 }
19729 /* We're not deferring instantiation any more. */
19737 out:
19747 }
19749 /* Run through the list of templates that we wish we could
19750 instantiate, and instantiate any we can. RETRIES is the
19751 number of times we retry pending template instantiation. */
19753 void
19755 {
19759 /* Instantiating templates may trigger vtable generation. This in turn
19760 may require further template instantiations. We place a limit here
19761 to avoid infinite loop. */
19763 {
19767 " instantiating %q+D, possibly from virtual table generation"
19771 /* Pretend that we defined it. */
19774 }
19776 do
19777 {
19782 {
19787 {
19788 tree fn;
19791 {
19795 fn;
19803 }
19806 }
19807 else
19808 {
19811 {
19812 instantiation
19818 }
19822 }
19825 /* If INSTANTIATION has been instantiated, then we don't
19826 need to consider it again in the future. */
19828 else
19829 {
19832 }
19835 }
19837 }
19841 }
19843 /* Substitute ARGVEC into T, which is a list of initializers for
19844 either base class or a non-static data member. The TREE_PURPOSEs
19845 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19846 instantiate_decl. */
19848 static tree
19850 {
19854 {
19855 tree decl;
19856 tree init;
19862 {
19863 tree expr;
19864 tree arg;
19866 /* Expand the base class expansion type into separate base
19867 classes. */
19869 tf_warning_or_error,
19870 NULL_TREE);
19874 /* We'll be building separate TREE_LISTs of arguments for
19875 each base. */
19881 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19882 expand each argument in the TREE_VALUE of t. */
19889 /* VOID_TYPE_NODE is used to indicate
19890 value-initialization. */
19891 {
19894 }
19895 else
19896 {
19897 /* Substitute parameter packs into each argument in the
19898 TREE_LIST. */
19901 {
19902 tree expanded_exprs;
19904 /* Expand the argument. */
19906 expanded_exprs
19908 tf_warning_or_error,
19909 NULL_TREE);
19913 /* Prepend each of the expanded expressions to the
19914 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19916 {
19921 }
19922 }
19925 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19926 since we built them backwards. */
19928 {
19931 }
19932 }
19933 }
19936 {
19938 {
19942 }
19943 else
19944 {
19945 tree tmp;
19960 /* If we had an initializer but it instantiated to nothing,
19961 value-initialize the object. This will only occur when
19962 the initializer was a pack expansion where the parameter
19963 packs used in that expansion were of length zero. */
19966 }
19969 {
19973 }
19974 }
19975 }
19977 }
19979 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19981 static void
19983 {
19988 else
19990 }
19992 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19993 is the instantiation (which should have been created with
19994 start_enum) and ARGS are the template arguments to use. */
19996 static void
19998 {
19999 tree e;
20005 {
20006 tree value;
20007 tree decl;
20010 /* Note that in a template enum, the TREE_VALUE is the
20011 CONST_DECL, not the corresponding INTEGER_CST. */
20016 /* Give this enumeration constant the correct access. */
20019 /* Actually build the enumerator itself. */
20020 build_enumerator
20022 }
20032 }
20034 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20035 its type -- but without substituting the innermost set of template
20036 arguments. So, innermost set of template parameters will appear in
20037 the type. */
20039 tree
20041 {
20042 tree fn_type;
20043 tree tmpl;
20044 tree targs;
20045 tree tparms;
20053 /* There should be as many levels of arguments as there are levels
20054 of parameters. */
20060 /* No substitution is necessary. */
20061 ;
20062 else
20063 {
20065 tree partial_args;
20067 /* Replace the innermost level of the TARGS with NULL_TREEs to
20068 let tsubst know not to substitute for those parameters. */
20077 /* Make sure that we can see identifiers, and compute access
20078 correctly. */
20082 /* Now, do the (partial) substitution to figure out the
20083 appropriate function type. */
20087 /* Substitute into the template parameters to obtain the real
20088 innermost set of parameters. This step is important if the
20089 innermost set of template parameters contains value
20090 parameters whose types depend on outer template parameters. */
20095 }
20098 }
20100 /* Return truthvalue if we're processing a template different from
20101 the last one involved in diagnostics. */
20102 int
20104 {
20106 }
20108 /* Remember current template involved in diagnostics. */
20109 void
20111 {
20113 }
20117 {
20119 }
20121 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20122 type. Return zero for ok, nonzero for disallowed. Issue error and
20123 warning messages under control of COMPLAIN. */
20125 static int
20127 {
20144 {
20147 else
20149 type);
20150 }
20152 }
20154 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20155 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20157 static bool
20159 {
20160 tree scope;
20162 /* [temp.dep.type]
20164 A type is dependent if it is:
20166 -- a template parameter. Template template parameters are types
20167 for us (since TYPE_P holds true for them) so we handle
20168 them here. */
20172 /* -- a qualified-id with a nested-name-specifier which contains a
20173 class-name that names a dependent type or whose unqualified-id
20174 names a dependent type. */
20177 /* -- a cv-qualified type where the cv-unqualified type is
20178 dependent. */
20180 /* -- a compound type constructed from any dependent type. */
20190 {
20191 tree arg_type;
20196 arg_type;
20201 }
20202 /* -- an array type constructed from any dependent type or whose
20203 size is specified by a constant expression that is
20204 value-dependent.
20206 We checked for type- and value-dependence of the bounds in
20207 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20209 {
20214 }
20216 /* -- a template-id in which either the template name is a template
20217 parameter ... */
20220 /* ... or any of the template arguments is a dependent type or
20221 an expression that is type-dependent or value-dependent. */
20223 && (any_dependent_template_arguments_p
20227 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20228 dependent; if the argument of the `typeof' expression is not
20229 type-dependent, then it should already been have resolved. */
20235 /* A template argument pack is dependent if any of its packed
20236 arguments are. */
20238 {
20244 }
20246 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20247 be template parameters. */
20251 /* The standard does not specifically mention types that are local
20252 to template functions or local classes, but they should be
20253 considered dependent too. For example:
20255 template <int I> void f() {
20256 enum E { a = I };
20257 S<sizeof (E)> s;
20258 }
20260 The size of `E' cannot be known until the value of `I' has been
20261 determined. Therefore, `E' must be considered dependent. */
20265 /* Don't use type_dependent_expression_p here, as it can lead
20266 to infinite recursion trying to determine whether a lambda
20267 nested in a lambda is dependent (c++/47687). */
20271 && (any_dependent_template_arguments_p
20275 /* Other types are non-dependent. */
20277 }
20279 /* Returns TRUE if TYPE is dependent, in the sense of
20280 [temp.dep.type]. Note that a NULL type is considered dependent. */
20282 bool
20284 {
20285 /* If there are no template parameters in scope, then there can't be
20286 any dependent types. */
20288 {
20289 /* If we are not processing a template, then nobody should be
20290 providing us with a dependent type. */
20294 }
20296 /* If the type is NULL, we have not computed a type for the entity
20297 in question; in that case, the type is dependent. */
20301 /* Erroneous types can be considered non-dependent. */
20305 /* If we have not already computed the appropriate value for TYPE,
20306 do so now. */
20308 {
20311 }
20314 }
20316 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20317 lookup. In other words, a dependent type that is not the current
20318 instantiation. */
20320 bool
20322 {
20325 }
20327 /* T is a SCOPE_REF; return whether we need to consider it
20328 instantiation-dependent so that we can check access at instantiation
20329 time even though we know which member it resolves to. */
20331 static bool
20333 {
20339 else
20341 }
20343 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20344 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20345 expression. */
20347 /* Note that this predicate is not appropriate for general expressions;
20348 only constant expressions (that satisfy potential_constant_expression)
20349 can be tested for value dependence. */
20351 bool
20353 {
20357 /* A name declared with a dependent type. */
20362 {
20364 /* A name that has not been looked up -- must be dependent. */
20368 /* A non-type template parm. */
20372 /* A non-type template parm. */
20378 /* A constant with literal type and is initialized
20379 with an expression that is value-dependent.
20381 Note that a non-dependent parenthesized initializer will have
20382 already been replaced with its constant value, so if we see
20383 a TREE_LIST it must be dependent. */
20396 /* These expressions are value-dependent if the type to which
20397 the cast occurs is dependent or the expression being casted
20398 is value-dependent. */
20399 {
20405 /* A functional cast has a list of operands. */
20408 {
20409 /* If there are no operands, it must be an expression such
20410 as "int()". This should not happen for aggregate types
20411 because it would form non-constant expressions. */
20416 }
20422 }
20427 /* FALLTHRU */
20430 /* A `sizeof' expression is value-dependent if the operand is
20431 type-dependent or is a pack expansion. */
20440 /* An 'encode' expression is value-dependent if the operand is
20441 type-dependent. */
20450 /* All instantiation-dependent expressions should also be considered
20451 value-dependent. */
20459 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20460 is value-dependent. */
20461 {
20470 }
20473 {
20477 }
20488 {
20492 }
20495 {
20502 {
20504 /* In a call to a constexpr member function, look through the
20505 implicit ADDR_EXPR on the object argument so that it doesn't
20506 cause the call to be considered value-dependent. We also
20507 look through it in potential_constant_expression. */
20514 }
20516 }
20519 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20520 type-dependent. */
20524 {
20526 tree val;
20531 }
20534 /* Treat a GNU statement expression as dependent to avoid crashing
20535 under fold_non_dependent_expr; it can't be constant. */
20539 /* A constant expression is value-dependent if any subexpression is
20540 value-dependent. */
20542 {
20549 {
20553 {
20556 /* In some cases, some of the operands may be missing.l
20557 (For example, in the case of PREDECREMENT_EXPR, the
20558 amount to increment by may be missing.) That doesn't
20559 make the expression dependent. */
20562 }
20563 }
20567 }
20569 }
20571 /* The expression is not value-dependent. */
20573 }
20575 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20576 [temp.dep.expr]. Note that an expression with no type is
20577 considered dependent. Other parts of the compiler arrange for an
20578 expression with type-dependent subexpressions to have no type, so
20579 this function doesn't have to be fully recursive. */
20581 bool
20583 {
20590 /* An unresolved name is always dependent. */
20594 /* Some expression forms are never type-dependent. */
20607 /* The types of these expressions depends only on the type to which
20608 the cast occurs. */
20617 /* The types of these expressions depends only on the type created
20618 by the expression. */
20621 {
20622 /* For NEW_EXPR tree nodes created inside a template, either
20623 the object type itself or a TREE_LIST may appear as the
20624 operand 1. */
20627 /* This is an array type. We need to check array dimensions
20628 as well. */
20630 || value_dependent_expression_p
20632 else
20634 }
20637 {
20641 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20642 contains an identifier associated by name lookup with one or more
20643 declarations declared with a dependent type, or...a
20644 nested-name-specifier or qualified-id that names a member of an
20645 unknown specialization. */
20648 }
20653 && (any_dependent_template_arguments_p
20665 {
20666 tree elt;
20670 {
20673 }
20675 }
20677 /* A static data member of the current instantiation with incomplete
20678 array type is type-dependent, as the definition and specializations
20679 can have different bounds. */
20686 /* An array of unknown bound depending on a variadic parameter, eg:
20688 template<typename... Args>
20689 void foo (Args... args)
20690 {
20691 int arr[] = { args... };
20692 }
20694 template<int... vals>
20695 void bar ()
20696 {
20697 int arr[] = { vals... };
20698 }
20700 If the array has no length and has an initializer, it must be that
20701 we couldn't determine its length in cp_complete_array_type because
20702 it is dependent. */
20710 {
20715 {
20721 }
20722 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20726 /* Always dependent, on the number of arguments if nothing else. */
20734 {
20739 }
20744 {
20748 }
20750 }
20755 }
20757 /* walk_tree callback function for instantiation_dependent_expression_p,
20758 below. Returns non-zero if a dependent subexpression is found. */
20760 static tree
20763 {
20765 {
20766 /* We don't have to worry about decltype currently because decltype
20767 of an instantiation-dependent expr is a dependent type. This
20768 might change depending on the resolution of DR 1172. */
20771 }
20774 {
20775 /* Don't treat an argument list as dependent just because it has no
20776 TREE_TYPE. */
20783 /* A constant with a dependent initializer is dependent. */
20791 /* Handle expressions with type operands. */
20796 {
20801 {
20804 else
20805 {
20808 }
20809 }
20811 }
20823 /* In a template, finish_class_member_access_expr creates a
20824 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
20825 type-dependent, so that we can check access control at
20826 instantiation time (PR 42277). See also Core issue 1273. */
20833 else
20836 /* Treat statement-expressions as dependent. */
20842 }
20846 else
20848 }
20850 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20851 sense defined by the ABI:
20853 "An expression is instantiation-dependent if it is type-dependent
20854 or value-dependent, or it has a subexpression that is type-dependent
20855 or value-dependent." */
20857 bool
20859 {
20860 tree result;
20871 }
20873 /* Like type_dependent_expression_p, but it also works while not processing
20874 a template definition, i.e. during substitution or mangling. */
20876 bool
20878 {
20884 }
20886 /* Returns TRUE if ARGS contains a type-dependent expression. */
20888 bool
20890 {
20892 tree arg;
20895 {
20898 }
20900 }
20902 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20903 expressions) contains any type-dependent expressions. */
20905 bool
20907 {
20913 }
20915 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20916 expressions) contains any value-dependent expressions. */
20918 bool
20920 {
20926 }
20928 /* Returns TRUE if the ARG (a template argument) is dependent. */
20930 bool
20932 {
20936 /* Assume a template argument that was wrongly written by the user
20937 is dependent. This is consistent with what
20938 any_dependent_template_arguments_p [that calls this function]
20939 does. */
20950 {
20954 {
20957 }
20960 }
20963 else
20966 }
20968 /* Returns true if ARGS (a collection of template arguments) contains
20969 any types that require structural equality testing. */
20971 bool
20973 {
20983 {
20986 {
20992 {
20993 /* Look inside the argument pack. */
20996 }
20999 {
21012 }
21013 }
21014 }
21017 }
21019 /* Returns true if ARGS (a collection of template arguments) contains
21020 any dependent arguments. */
21022 bool
21024 {
21034 {
21039 }
21042 }
21044 /* Returns TRUE if the template TMPL is dependent. */
21046 bool
21048 {
21050 {
21052 {
21056 }
21058 }
21060 /* Template template parameters are dependent. */
21064 /* So are names that have not been looked up. */
21067 /* So are member templates of dependent classes. */
21071 }
21073 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21075 bool
21077 {
21080 }
21082 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21083 is dependent. */
21085 bool
21087 {
21094 {
21115 {
21119 }
21123 {
21127 {
21132 }
21133 }
21134 }
21137 }
21139 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21140 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21141 no such TYPE can be found. Note that this function peers inside
21142 uninstantiated templates and therefore should be used only in
21143 extremely limited situations. ONLY_CURRENT_P restricts this
21144 peering to the currently open classes hierarchy (which is required
21145 when comparing types). */
21147 tree
21149 {
21150 tree scope;
21151 tree name;
21152 tree decl;
21154 tree pushed_scope;
21155 tree result;
21160 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21161 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21162 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21163 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21164 identifier of the TYPENAME_TYPE anymore.
21165 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21166 TYPENAME_TYPE instead, we avoid messing up with a possible
21167 typedef variant case. */
21170 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21171 it first before we can figure out what NAME refers to. */
21173 {
21175 /* Given a class template A with a dependent base with nested type C,
21176 typedef typename A::C::C C will land us here, as trying to resolve
21177 the initial A::C leads to the local C typedef, which leads back to
21178 A::C::C. So we break the recursion now. */
21180 else
21182 }
21183 /* If we don't know what SCOPE refers to, then we cannot resolve the
21184 TYPENAME_TYPE. */
21187 /* If the SCOPE is a template type parameter, we have no way of
21188 resolving the name. */
21191 /* If the SCOPE is not the current instantiation, there's no reason
21192 to look inside it. */
21195 /* If this is a typedef, we don't want to look inside (c++/11987). */
21198 /* If SCOPE isn't the template itself, it will not have a valid
21199 TYPE_FIELDS list. */
21201 /* scope is either the template itself or a compatible instantiation
21202 like X<T>, so look up the name in the original template. */
21204 else
21205 /* scope is a partial instantiation, so we can't do the lookup or we
21206 will lose the template arguments. */
21208 /* Enter the SCOPE so that name lookup will be resolved as if we
21209 were in the class definition. In particular, SCOPE will no
21210 longer be considered a dependent type. */
21212 /* Look up the declaration. */
21214 tf_warning_or_error);
21218 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21219 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21224 {
21228 }
21231 {
21232 tree tmpl;
21233 tree args;
21234 /* Obtain the template and the arguments. */
21237 /* Instantiate the template. */
21243 }
21245 /* Leave the SCOPE. */
21249 /* If we failed to resolve it, return the original typename. */
21253 /* If lookup found a typename type, resolve that too. */
21255 {
21256 /* Ill-formed programs can cause infinite recursion here, so we
21257 must catch that. */
21261 }
21263 /* Qualify the resulting type. */
21269 }
21271 /* EXPR is an expression which is not type-dependent. Return a proxy
21272 for EXPR that can be used to compute the types of larger
21273 expressions containing EXPR. */
21275 tree
21277 {
21278 tree inner_expr;
21280 #ifdef ENABLE_CHECKING
21281 /* Try to get a constant value for all non-dependent expressions in
21282 order to expose bugs in *_dependent_expression_p and constexpr. */
21285 #endif
21287 /* Preserve OVERLOADs; the functions must be available to resolve
21288 types. */
21299 /* There is no need to return a proxy for a variable. */
21302 /* Preserve string constants; conversions from string constants to
21303 "char *" are allowed, even though normally a "const char *"
21304 cannot be used to initialize a "char *". */
21307 /* Preserve arithmetic constants, as an optimization -- there is no
21308 reason to create a new node. */
21311 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21312 There is at least one place where we want to know that a
21313 particular expression is a throw-expression: when checking a ?:
21314 expression, there are special rules if the second or third
21315 argument is a throw-expression. */
21319 /* Don't wrap an initializer list, we need to be able to look inside. */
21323 /* Don't wrap a dummy object, we need to be able to test for it. */
21342 /* If the type is unknown, it can't really be non-dependent */
21345 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21347 }
21349 /* ARGS is a vector of expressions as arguments to a function call.
21350 Replace the arguments with equivalent non-dependent expressions.
21351 This modifies ARGS in place. */
21353 void
21355 {
21357 tree arg;
21360 {
21364 }
21365 }
21367 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21368 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21369 parms. */
21371 static tree
21373 {
21386 }
21388 tree
21390 {
21392 }
21394 tree
21396 {
21398 }
21400 /* Given type ARG, return std::initializer_list<ARG>. */
21402 static tree
21404 {
21405 tree std_init_list = namespace_binding
21407 tree argvec;
21409 {
21413 }
21418 }
21420 /* Replace auto in TYPE with std::initializer_list<auto>. */
21422 static tree
21424 {
21431 }
21433 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21434 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21436 tree
21438 {
21439 tree targs;
21445 /* Defining a subset of type-dependent expressions that we can deduce
21446 from ahead of time isn't worth the trouble. */
21449 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21450 with either a new invented type template parameter U or, if the
21451 initializer is a braced-init-list (8.5.4), with
21452 std::initializer_list<U>. */
21460 {
21465 {
21468 }
21469 }
21470 else
21471 {
21482 {
21484 /* Try again at instantiation time. */
21487 /* If type is error_mark_node a diagnostic must have been
21488 emitted by now. Also, having a mention to '<type error>'
21489 in the diagnostic is not really useful to the user. */
21490 {
21494 else
21496 }
21498 }
21499 }
21501 /* If the list of declarators contains more than one declarator, the type
21502 of each declared variable is determined as described above. If the
21503 type deduced for the template parameter U is not the same in each
21504 deduction, the program is ill-formed. */
21507 {
21513 else
21517 }
21523 }
21525 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21526 result. */
21528 tree
21530 {
21531 tree argvec;
21538 /* For a late-specified return type in a template type-parameter, we
21539 need to add a dummy argument level for its parmlist. */
21540 argvec = add_to_template_args
21545 }
21547 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21548 'decltype(auto)'. */
21550 bool
21552 {
21557 else
21559 }
21561 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21562 a use of `auto'. Returns NULL_TREE otherwise. */
21564 tree
21566 {
21568 }
21570 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21571 'decltype(auto)' or a concept. */
21573 bool
21575 {
21577 }
21579 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21580 a concept identifier) iff TYPE contains a use of a generic type. Returns
21581 NULL_TREE otherwise. */
21583 tree
21585 {
21587 }
21590 /* For a given template T, return the vector of typedefs referenced
21591 in T for which access check is needed at T instantiation time.
21592 T is either a FUNCTION_DECL or a RECORD_TYPE.
21593 Those typedefs were added to T by the function
21594 append_type_to_template_for_access_check. */
21598 {
21599 tree ti;
21610 {
21615 }
21618 }
21620 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21621 tied to T. That list of typedefs will be access checked at
21622 T instantiation time.
21623 T is either a FUNCTION_DECL or a RECORD_TYPE.
21624 TYPE_DECL is a TYPE_DECL node representing a typedef.
21625 SCOPE is the scope through which TYPE_DECL is accessed.
21626 LOCATION is the location of the usage point of TYPE_DECL.
21628 This function is a subroutine of
21629 append_type_to_template_for_access_check. */
21631 static void
21633 tree type_decl,
21634 tree scope,
21635 location_t location)
21636 {
21637 qualified_typedef_usage_t typedef_usage;
21638 tree ti;
21645 && type_decl
21659 }
21661 /* Append TYPE_DECL to the template TEMPL.
21662 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21663 At TEMPL instanciation time, TYPE_DECL will be checked to see
21664 if it can be accessed through SCOPE.
21665 LOCATION is the location of the usage point of TYPE_DECL.
21667 e.g. consider the following code snippet:
21669 class C
21670 {
21671 typedef int myint;
21672 };
21674 template<class U> struct S
21675 {
21676 C::myint mi; // <-- usage point of the typedef C::myint
21677 };
21679 S<char> s;
21681 At S<char> instantiation time, we need to check the access of C::myint
21682 In other words, we need to check the access of the myint typedef through
21683 the C scope. For that purpose, this function will add the myint typedef
21684 and the scope C through which its being accessed to a list of typedefs
21685 tied to the template S. That list will be walked at template instantiation
21686 time and access check performed on each typedefs it contains.
21687 Note that this particular code snippet should yield an error because
21688 myint is private to C. */
21690 void
21692 tree type_decl,
21693 tree scope,
21694 location_t location)
21695 {
21701 /* Make sure we don't append the type to the template twice. */
21708 }
21710 /* Convert the generic type parameters in PARM that match the types given in the
21711 range [START_IDX, END_IDX) from the current_template_parms into generic type
21712 packs. */
21714 tree
21716 {
21727 {
21728 /* Create a distinct parameter pack type from the current parm and add it
21729 to the replacement args to tsubst below into the generic function
21730 parameter. */
21745 }
21751 /* If there are more levels then build up the replacement with the outer
21752 template parms. */
21756 replacement);
21759 }
21762 /* Set up the hash tables for template instantiations. */
21764 void
21766 {
21768 hash_specialization,
21769 eq_specializations,
21770 ggc_free);
21772 hash_specialization,
21773 eq_specializations,
21774 ggc_free);
21775 }
21777 /* Print stats about the template hash tables for -fstats. */
21779 void
21781 {
21790 }