| blob | 9c423366102440840e71197842135d754a33b089 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 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". */
44 /* The type of functions taking a tree, and some additional data, and
45 returning an int. */
48 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
49 instantiations have been deferred, either because their definitions
50 were not yet available, or because we were putting off doing the work. */
54 };
69 /* Live only within one (recursive) call to tsubst_expr. We use
70 this to pass the statement expression node from the STMT_EXPR
71 to the EXPR_STMT that is its result. */
74 // -------------------------------------------------------------------------- //
75 // Local Specialization Stack
76 //
77 // Implementation of the RAII helper for creating new local
78 // specializations.
81 {
83 }
86 {
89 }
91 /* True if we've recursed into fn_type_unification too many times. */
95 {
96 tree tmpl;
97 tree args;
98 tree spec;
99 };
102 {
105 };
111 /* Contains canonical template parameter types. The vector is indexed by
112 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
113 TREE_LIST, whose TREE_VALUEs contain the canonical template
114 parameters of various types and levels. */
117 #define UNIFY_ALLOW_NONE 0
118 #define UNIFY_ALLOW_MORE_CV_QUAL 1
119 #define UNIFY_ALLOW_LESS_CV_QUAL 2
120 #define UNIFY_ALLOW_DERIVED 4
121 #define UNIFY_ALLOW_INTEGER 8
122 #define UNIFY_ALLOW_OUTER_LEVEL 16
123 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
124 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
127 tbr_incomplete_type,
128 tbr_ambiguous_baseclass,
129 tbr_success
130 };
153 tree);
210 location_t);
220 /* Make the current scope suitable for access checking when we are
221 processing T. T can be FUNCTION_DECL for instantiated function
222 template, VAR_DECL for static member variable, or TYPE_DECL for
223 alias template (needed by instantiate_decl). */
225 static void
227 {
235 else
239 {
240 saved_access_scope = tree_cons
243 }
244 }
246 /* Restore the scope set up by push_access_scope. T is the node we
247 are processing. */
249 static void
251 {
253 {
256 }
260 else
262 }
264 /* Do any processing required when DECL (a member template
265 declaration) is finished. Returns the TEMPLATE_DECL corresponding
266 to DECL, unless it is a specialization, in which case the DECL
267 itself is returned. */
269 tree
271 {
278 {
279 tree type;
287 {
291 }
293 }
297 {
299 {
302 }
303 else
305 }
306 else
310 }
312 /* Create a template info node. */
314 tree
316 {
321 }
323 /* Return the template info node corresponding to T, whatever T is. */
325 tree
327 {
349 }
351 /* Returns the template nesting level of the indicated class TYPE.
353 For example, in:
354 template <class T>
355 struct A
356 {
357 template <class U>
358 struct B {};
359 };
361 A<T>::B<U> has depth two, while A<T> has depth one.
362 Both A<T>::B<int> and A<int>::B<U> have depth one, if
363 they are instantiations, not specializations.
365 This function is guaranteed to return 0 if passed NULL_TREE so
366 that, for example, `template_class_depth (current_class_type)' is
367 always safe. */
369 int
371 {
375 {
386 else
388 }
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Returns true if processing DECL needs us to push template parms. */
396 static bool
398 {
404 }
406 /* Subroutine of maybe_begin_member_template_processing.
407 Push the template parms in PARMS, starting from LEVELS steps into the
408 chain, and ending at the beginning, since template parms are listed
409 innermost first. */
411 static void
413 {
421 current_template_parms
427 NULL);
429 {
438 {
445 /* Push the CONST_DECL. */
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to insert the TEMPLATE_DECL for S2
653 at the right scope. */
659 /* Add a dummy parameter level while we process the parameter list. */
660 current_template_parms
663 current_template_parms);
664 }
666 /* This routine is called when a specialization is declared. If it is
667 invalid to declare a specialization here, an error is reported and
668 false is returned, otherwise this routine will return true. */
670 static bool
672 {
675 /* [temp.expl.spec]
677 An explicit specialization shall be declared in the namespace of
678 which the template is a member, or, for member templates, in the
679 namespace of which the enclosing class or enclosing class
680 template is a member. An explicit specialization of a member
681 function, member class or static data member of a class template
682 shall be declared in the namespace of which the class template
683 is a member. */
685 {
688 }
690 /* [temp.expl.spec]
692 In an explicit specialization declaration for a member of a class
693 template or a member template that appears in namespace scope,
694 the member template and some of its enclosing class templates may
695 remain unspecialized, except that the declaration shall not
696 explicitly specialize a class member template if its enclosing
697 class templates are not explicitly specialized as well. */
699 {
702 }
705 }
707 /* We've just seen template <>. */
709 bool
711 {
715 }
717 /* Called at then end of processing a declaration preceded by
718 template<>. */
720 void
722 {
725 }
727 /* Any template <>'s that we have seen thus far are not referring to a
728 function specialization. */
730 void
732 {
735 }
737 /* We've just seen a template header. If SPECIALIZATION is nonzero,
738 it was of the form template <>. */
740 static void
742 {
744 template_header_count++;
745 }
747 /* We're beginning an explicit instantiation. */
749 void
751 {
754 }
757 void
759 {
762 }
764 /* An explicit specialization or partial specialization of TMPL is being
765 declared. Check that the namespace in which the specialization is
766 occurring is permissible. Returns false iff it is invalid to
767 specialize TMPL in the current namespace. */
769 static bool
771 {
774 /* [tmpl.expl.spec]
776 An explicit specialization shall be declared in a namespace enclosing the
777 specialized template. An explicit specialization whose declarator-id is
778 not qualified shall be declared in the nearest enclosing namespace of the
779 template, or, if the namespace is inline (7.3.1), any namespace from its
780 enclosing namespace set. */
783 {
786 }
789 /* Same or enclosing namespace. */
791 else
792 {
798 }
799 }
801 /* SPEC is an explicit instantiation. Check that it is valid to
802 perform this explicit instantiation in the current namespace. */
804 static void
806 {
807 tree ns;
809 /* DR 275: An explicit instantiation shall appear in an enclosing
810 namespace of its template. */
816 }
818 // Returns the type of a template specialization only if that
819 // specialization needs to be defined. Otherwise (e.g., if the type has
820 // already been defined), the function returns NULL_TREE.
821 static tree
823 {
824 // An implicit instantiation of an incomplete type implies
825 // the definition of a new class template.
826 //
827 // template<typename T>
828 // struct S;
829 //
830 // template<typename T>
831 // struct S<T*>;
832 //
833 // Here, S<T*> is an implicit instantiation of S whose type
834 // is incomplete.
838 // It can also be the case that TYPE is a completed specialization.
839 // Continuing the previous example, suppose we also declare:
840 //
841 // template<typename T>
842 // requires Integral<T>
843 // struct S<T*>;
844 //
845 // Here, S<T*> refers to the specialization S<T*> defined
846 // above. However, we need to differentiate definitions because
847 // we intend to define a new partial specialization. In this case,
848 // we rely on the fact that the constraints are different for
849 // this declaration than that above.
850 //
851 // Note that we also get here for injected class names and
852 // late-parsed template definitions. We must ensure that we
853 // do not create new type declarations for those cases.
855 {
859 // If there are no template parameters, this cannot be a new
860 // partial template specializtion?
864 // The injected-class-name is not a new partial specialization.
868 // If the constraints are not the same as those of the primary
869 // then, we can probably create a new specialization.
873 {
877 }
879 // Also, if there's a pre-existing specialization with matching
880 // constraints, then this also isn't new.
883 {
891 }
893 // Create a new type node (and corresponding type decl)
894 // for the newly declared specialization.
899 /* We only need a separate type node for storing the definition of this
900 partial specialization; uses of S<T*> are unconstrained, so all are
901 equivalent. So keep TYPE_CANONICAL the same. */
904 // Build the corresponding type decl.
910 }
913 }
915 /* The TYPE is being declared. If it is a template type, that means it
916 is a partial specialization. Do appropriate error-checking. */
918 tree
920 {
921 tree context;
926 /* A lambda that appears in specialization context is not itself a
927 specialization. */
932 {
936 }
941 {
947 else
950 }
952 {
953 /* This is for ordinary explicit specialization and partial
954 specialization of a template class such as:
956 template <> class C<int>;
958 or:
960 template <class T> class C<T*>;
962 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
965 {
972 {
977 }
978 }
984 /* Trying to define a specialization either without a template<> header
985 or in an inappropriate place. We've already given an error, so just
986 bail now so we don't actually define the specialization. */
988 }
994 {
995 /* This is for an explicit specialization of member class
996 template according to [temp.expl.spec/18]:
998 template <> template <class U> class C<int>::D;
1000 The context `C<int>' must be an implicit instantiation.
1001 Otherwise this is just a member class template declared
1002 earlier like:
1004 template <> class C<int> { template <class U> class D; };
1005 template <> template <class U> class C<int>::D;
1007 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1008 while in the second case, `C<int>::D' is a primary template
1009 and `C<T>::D' may not exist. */
1013 {
1014 tree t;
1019 {
1024 }
1026 /* Check for invalid specialization after instantiation:
1028 template <> template <> class C<int>::D<int>;
1029 template <> template <class U> class C<int>::D; */
1033 {
1037 {
1038 /* We already have a full specialization of this partial
1039 instantiation, or a full specialization has been
1040 looked up but not instantiated. Reassign it to the
1041 new member specialization template. */
1042 spec_entry elt;
1054 spec_entry **slot
1059 }
1060 else
1061 /* But if we've had an implicit instantiation, that's a
1062 problem ([temp.expl.spec]/6). */
1065 }
1067 /* Mark TYPE as a specialization. And as a result, we only
1068 have one level of template argument for the innermost
1069 class template. */
1074 }
1075 }
1077 {
1078 /* Someday C++0x may allow for enum template specialization. */
1083 else
1084 {
1087 }
1088 }
1091 }
1093 /* Returns nonzero if we can optimize the retrieval of specializations
1094 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1095 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1099 {
1102 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1103 parameter. */
1105 /* The optimized lookup depends on the fact that the
1106 template arguments for the member function template apply
1107 purely to the containing class, which is not true if the
1108 containing class is an explicit or partial
1109 specialization. */
1113 /* It is possible to have a template that is not a member
1114 template and is not a member of a template class:
1116 template <typename T>
1117 struct S { friend A::f(); };
1119 Here, the friend function is a template, but the context does
1120 not have template information. The optimized lookup relies
1121 on having ARGS be the template arguments for both the class
1122 and the function template. */
1124 }
1126 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1127 gone through coerce_template_parms by now. */
1129 static void
1131 {
1134 {
1137 {
1144 /* Allow typedefs on the type of a non-type argument, since a
1146 else
1148 }
1149 }
1151 }
1153 /* Retrieve the specialization (in the sense of [temp.spec] - a
1154 specialization is either an instantiation or an explicit
1155 specialization) of TMPL for the given template ARGS. If there is
1156 no such specialization, return NULL_TREE. The ARGS are a vector of
1157 arguments, or a vector of vectors of arguments, in the case of
1158 templates with more than one level of parameters.
1160 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1161 then we search for a partial specialization matching ARGS. This
1162 parameter is ignored if TMPL is not a class template.
1164 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1165 result is a NONTYPE_ARGUMENT_PACK. */
1167 static tree
1169 {
1179 /* There should be as many levels of arguments as there are
1180 levels of parameters. */
1190 {
1191 /* The template arguments actually apply to the containing
1192 class. Find the class specialization with those
1193 arguments. */
1195 tree class_specialization
1199 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1200 for the specialization. */
1204 /* Iterate through the methods with the indicated name, looking
1205 for the one that has an instance of TMPL. */
1208 {
1211 /* using-declarations can add base methods to the method vec,
1212 and we don't want those here. */
1215 }
1217 }
1218 else
1219 {
1221 spec_entry elt;
1230 else
1238 }
1241 }
1243 /* Like retrieve_specialization, but for local declarations. */
1245 tree
1247 {
1253 }
1255 /* Returns nonzero iff DECL is a specialization of TMPL. */
1257 int
1259 {
1260 tree t;
1263 {
1269 }
1270 else
1271 {
1280 }
1283 }
1285 /* Returns nonzero iff DECL is a specialization of friend declaration
1286 FRIEND_DECL according to [temp.friend]. */
1288 bool
1290 {
1297 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1298 of a template class, we want to check if DECL is a specialization
1299 if this. */
1303 {
1304 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1307 }
1312 /* There is nothing to do if this is not a template friend. */
1319 /* [temp.friend/6]
1320 A member of a class template may be declared to be a friend of a
1321 non-template class. In this case, the corresponding member of
1322 every specialization of the class template is a friend of the
1323 class granting friendship.
1325 For example, given a template friend declaration
1327 template <class T> friend void A<T>::f();
1329 the member function below is considered a friend
1331 template <> struct A<int> {
1332 void f();
1333 };
1335 For this type of template friend, TEMPLATE_DEPTH below will be
1336 nonzero. To determine if DECL is a friend of FRIEND, we first
1337 check if the enclosing class is a specialization of another. */
1344 {
1345 /* Next, we check the members themselves. In order to handle
1346 a few tricky cases, such as when FRIEND_DECL's are
1348 template <class T> friend void A<T>::g(T t);
1349 template <class T> template <T t> friend void A<T>::h();
1351 and DECL's are
1353 void A<int>::g(int);
1354 template <int> void A<int>::h();
1356 we need to figure out ARGS, the template arguments from
1357 the context of DECL. This is required for template substitution
1358 of `T' in the function parameter of `g' and template parameter
1359 of `h' in the above examples. Here ARGS corresponds to `int'. */
1366 {
1368 {
1371 else
1373 current_depth++;
1374 }
1376 }
1379 {
1381 tree friend_type;
1382 tree decl_type;
1383 tree friend_args_type;
1384 tree decl_args_type;
1386 /* Make sure that both DECL and FRIEND_DECL are templates or
1387 non-templates. */
1393 {
1394 /* If both are templates, check template parameter list. */
1395 tree friend_parms
1400 friend_parms))
1404 }
1405 else
1413 /* Check if return types match. */
1417 /* Check if function parameter types match, ignoring the
1418 `this' parameter. */
1427 }
1428 else
1429 {
1430 /* DECL is a TYPE_DECL */
1434 /* Make sure that both DECL and FRIEND_DECL are templates or
1435 non-templates. */
1436 is_template
1443 {
1444 tree friend_parms;
1445 /* If both are templates, check the name of the two
1446 TEMPLATE_DECL's first because is_friend didn't. */
1451 /* Now check template parameter list. */
1452 friend_parms
1455 return comp_template_parms
1457 friend_parms);
1458 }
1459 else
1462 }
1463 }
1465 }
1467 /* Register the specialization SPEC as a specialization of TMPL with
1468 the indicated ARGS. IS_FRIEND indicates whether the specialization
1469 is actually just a friend declaration. Returns SPEC, or an
1470 equivalent prior declaration, if available.
1472 We also store instantiations of field packs in the hash table, even
1473 though they are not themselves templates, to make lookup easier. */
1475 static tree
1477 hashval_t hash)
1478 {
1479 tree fn;
1481 spec_entry elt;
1489 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1490 register it; we want the corresponding TEMPLATE_DECL instead.
1491 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1492 the more obvious `uses_template_parms (spec)' to avoid problems
1493 with default function arguments. In particular, given
1494 something like this:
1496 template <class T> void f(T t1, T t = T())
1498 the default argument expression is not substituted for in an
1499 instantiation unless and until it is actually needed. */
1503 /* We don't put these specializations in the hash table, but we might
1504 want to give an error about a mismatch. */
1506 else
1507 {
1515 slot =
1519 else
1521 }
1523 /* We can sometimes try to re-register a specialization that we've
1524 already got. In particular, regenerate_decl_from_template calls
1525 duplicate_decls which will update the specialization list. But,
1526 we'll still get called again here anyhow. It's more convenient
1527 to simply allow this than to try to prevent it. */
1531 {
1533 {
1536 {
1538 fn);
1540 }
1541 else
1542 {
1543 tree clone;
1544 /* This situation should occur only if the first
1545 specialization is an implicit instantiation, the
1546 second is an explicit specialization, and the
1547 implicit instantiation has not yet been used. That
1548 situation can occur if we have implicitly
1549 instantiated a member function and then specialized
1550 it later.
1552 We can also wind up here if a friend declaration that
1553 looked like an instantiation turns out to be a
1554 specialization:
1556 template <class T> void foo(T);
1557 class S { friend void foo<>(int) };
1558 template <> void foo(int);
1560 We transform the existing DECL in place so that any
1561 pointers to it become pointers to the updated
1562 declaration.
1564 If there was a definition for the template, but not
1565 for the specialization, we want this to look as if
1566 there were no definition, and vice versa. */
1569 /* The call to duplicate_decls will have applied
1570 [temp.expl.spec]:
1572 An explicit specialization of a function template
1573 is inline only if it is explicitly declared to be,
1574 and independently of whether its function template
1575 is.
1577 to the primary function; now copy the inline bits to
1578 the various clones. */
1580 {
1587 }
1591 }
1592 }
1594 {
1597 /* We've already complained in duplicate_decls. */
1601 /* Dup decl failed, but this is a new definition. Set the
1602 line number so any errors match this new
1603 definition. */
1607 }
1608 }
1612 /* A specialization must be declared in the same namespace as the
1613 template it is specializing. */
1619 {
1628 /* If TMPL is a forward declaration of a template function, keep a list
1629 of all specializations in case we need to reassign them to a friend
1630 template later in tsubst_friend_function.
1632 Also keep a list of all variable template instantiations so that
1633 process_partial_specialization can check whether a later partial
1634 specialization would have used it. */
1637 }
1640 }
1642 /* Returns true iff two spec_entry nodes are equivalent. */
1646 bool
1648 {
1655 /* tmpl could be a FIELD_DECL for a capture pack. */
1659 {
1660 /* Partial specializations of a variable template can be distinguished by
1661 constraints. */
1665 }
1669 }
1671 /* Returns a hash for a template TMPL and template arguments ARGS. */
1673 static hashval_t
1675 {
1678 }
1680 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1681 ignoring SPEC. */
1683 hashval_t
1685 {
1687 }
1689 /* Recursively calculate a hash value for a template argument ARG, for use
1690 in the hash tables of template specializations. */
1692 hashval_t
1694 {
1714 {
1722 {
1727 }
1749 {
1753 {
1756 }
1758 }
1762 {
1765 }
1776 val = iterative_hash_template_arg
1788 val);
1790 val);
1799 /* A lambda can't appear in a template arg, but don't crash on
1800 erroneous input. */
1812 /* Now hash operands as usual. */
1817 }
1820 {
1823 {
1824 // We want an alias specialization that survived strip_typedefs
1825 // to hash differently from its TYPE_CANONICAL, to avoid hash
1826 // collisions that compare as different in template_args_equal.
1827 // These could be dependent specializations that strip_typedefs
1828 // left alone, or untouched specializations because
1829 // coerce_template_parms returns the unconverted template
1830 // arguments if it sees incomplete argument packs.
1833 }
1836 val);
1839 /* Otherwise just compare the types during lookup. */
1848 {
1853 }
1854 }
1857 }
1859 /* Unregister the specialization SPEC as a specialization of TMPL.
1860 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1861 if the SPEC was listed as a specialization of TMPL.
1863 Note that SPEC has been ggc_freed, so we can't look inside it. */
1865 bool
1867 {
1869 spec_entry elt;
1877 {
1882 }
1885 }
1887 /* Like register_specialization, but for local declarations. We are
1888 registering SPEC, an instantiation of TMPL. */
1890 void
1892 {
1894 }
1896 /* TYPE is a class type. Returns true if TYPE is an explicitly
1897 specialized class. */
1899 bool
1901 {
1905 }
1907 /* Print the list of functions at FNS, going through all the overloads
1908 for each element of the list. Alternatively, FNS can not be a
1909 TREE_LIST, in which case it will be printed together with all the
1910 overloads.
1912 MORE and *STR should respectively be FALSE and NULL when the function
1913 is called from the outside. They are used internally on recursive
1914 calls. print_candidates manages the two parameters and leaves NULL
1915 in *STR when it ends. */
1917 static void
1919 {
1923 else
1925 {
1931 {
1934 else
1937 }
1939 }
1940 }
1942 /* Print the list of candidate FNS in an error message. FNS can also
1943 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1945 void
1947 {
1951 }
1953 /* Get a (possibly) constrained template declaration for the
1954 purpose of ordering candidates. */
1955 static tree
1957 {
1963 }
1965 /* Among candidates having the same signature, return the
1966 most constrained or NULL_TREE if there is no best candidate.
1967 If the signatures of candidates vary (e.g., template
1968 specialization vs. member function), then there can be no
1969 most constrained.
1971 Note that we don't compare constraints on the functions
1972 themselves, but rather those of their templates. */
1973 static tree
1975 {
1976 // Try to find the best candidate in a first pass.
1979 {
1986 }
1988 // Verify that the champ is better than previous candidates.
1993 }
1996 }
1999 /* Returns the template (one of the functions given by TEMPLATE_ID)
2000 which can be specialized to match the indicated DECL with the
2001 explicit template args given in TEMPLATE_ID. The DECL may be
2002 NULL_TREE if none is available. In that case, the functions in
2003 TEMPLATE_ID are non-members.
2005 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2006 specialization of a member template.
2008 The TEMPLATE_COUNT is the number of references to qualifying
2009 template classes that appeared in the name of the function. See
2010 check_explicit_specialization for a more accurate description.
2012 TSK indicates what kind of template declaration (if any) is being
2013 declared. TSK_TEMPLATE indicates that the declaration given by
2014 DECL, though a FUNCTION_DECL, has template parameters, and is
2015 therefore a template function.
2017 The template args (those explicitly specified and those deduced)
2018 are output in a newly created vector *TARGS_OUT.
2020 If it is impossible to determine the result, an error message is
2021 issued. The error_mark_node is returned to indicate failure. */
2023 static tree
2025 tree decl,
2029 tmpl_spec_kind tsk)
2030 {
2031 tree fns;
2032 tree targs;
2033 tree explicit_targs;
2036 /* A TREE_LIST of templates of which DECL may be a specialization.
2037 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2038 corresponding TREE_PURPOSE is the set of template arguments that,
2039 when used to instantiate the template, would produce a function
2040 with the signature of DECL. */
2050 /* We shouldn't be specializing a member template of an
2051 unspecialized class template; we already gave an error in
2052 check_specialization_scope, now avoid crashing. */
2055 {
2058 }
2066 /* Check for baselinks. */
2071 {
2074 }
2076 {
2079 }
2081 /* Count the number of template headers specified for this
2082 specialization. */
2092 {
2095 tf_warning_or_error,
2099 }
2101 {
2105 {
2106 tree decl_arg_types;
2107 tree fn_arg_types;
2108 tree insttype;
2110 /* In case of explicit specialization, we need to check if
2111 the number of template headers appearing in the specialization
2112 is correct. This is usually done in check_explicit_specialization,
2113 but the check done there cannot be exhaustive when specializing
2114 member functions. Consider the following code:
2116 template <> void A<int>::f(int);
2117 template <> template <> void A<int>::f(int);
2119 Assuming that A<int> is not itself an explicit specialization
2120 already, the first line specializes "f" which is a non-template
2121 member function, whilst the second line specializes "f" which
2122 is a template member function. So both lines are syntactically
2123 correct, and check_explicit_specialization does not reject
2124 them.
2126 Here, we can do better, as we are matching the specialization
2127 against the declarations. We count the number of template
2128 headers, and we check if they match TEMPLATE_COUNT + 1
2129 (TEMPLATE_COUNT is the number of qualifying template classes,
2130 plus there must be another header for the member template
2131 itself).
2133 Notice that if header_count is zero, this is not a
2134 specialization but rather a template instantiation, so there
2135 is no check we can perform here. */
2139 /* Check that the number of template arguments at the
2140 innermost level for DECL is the same as for FN. */
2148 /* DECL might be a specialization of FN. */
2152 /* For a non-static member function, we need to make sure
2153 that the const qualification is the same. Since
2154 get_bindings does not try to merge the "this" parameter,
2155 we must do the comparison explicitly. */
2161 /* Skip the "this" parameter and, for constructors of
2162 classes with virtual bases, the VTT parameter. A
2163 full specialization of a constructor will have a VTT
2164 parameter, but a template never will. */
2165 decl_arg_types
2167 fn_arg_types
2170 /* Function templates cannot be specializations; there are
2171 no partial specializations of functions. Therefore, if
2172 the type of DECL does not match FN, there is no
2173 match.
2175 Note that it should never be the case that we have both
2176 candidates added here, and for regular member functions
2177 below. */
2179 {
2183 }
2185 /* See whether this function might be a specialization of this
2186 template. Suppress access control because we might be trying
2187 to make this specialization a friend, and we have already done
2188 access control for the declaration of the specialization. */
2194 /* We cannot deduce template arguments that when used to
2195 specialize TMPL will produce DECL. */
2198 /* Remove, from the set of candidates, all those functions
2199 whose constraints are not satisfied. */
2203 // Then, try to form the new function type.
2207 fn_arg_types
2212 /* Save this template, and the arguments deduced. */
2214 }
2216 /* FN is an ordinary member function, and we need a
2217 specialization of a member template. */
2218 ;
2220 /* We can get IDENTIFIER_NODEs here in certain erroneous
2221 cases. */
2222 ;
2224 /* This is just an ordinary non-member function. Nothing can
2225 be a specialization of that. */
2226 ;
2228 /* Cannot specialize functions that are created implicitly. */
2229 ;
2230 else
2231 {
2232 tree decl_arg_types;
2234 /* This is an ordinary member function. However, since
2235 we're here, we can assume its enclosing class is a
2236 template class. For example,
2238 template <typename T> struct S { void f(); };
2239 template <> void S<int>::f() {}
2241 Here, S<int>::f is a non-template, but S<int> is a
2242 template class. If FN has the same type as DECL, we
2243 might be in business. */
2246 /* Its enclosing class is an explicit specialization
2247 of a template class. This is not a candidate. */
2252 /* The return types differ. */
2255 /* Adjust the type of DECL in case FN is a static member. */
2262 decl_arg_types))
2265 // If the deduced arguments do not satisfy the constraints,
2266 // this is not a candidate.
2270 // Add the candidate.
2272 }
2273 }
2276 {
2277 /* We have:
2279 [temp.expl.spec]
2281 It is possible for a specialization with a given function
2282 signature to be instantiated from more than one function
2283 template. In such cases, explicit specification of the
2284 template arguments must be used to uniquely identify the
2285 function template specialization being specialized.
2287 Note that here, there's no suggestion that we're supposed to
2288 determine which of the candidate templates is most
2289 specialized. However, we, also have:
2291 [temp.func.order]
2293 Partial ordering of overloaded function template
2294 declarations is used in the following contexts to select
2295 the function template to which a function template
2296 specialization refers:
2298 -- when an explicit specialization refers to a function
2299 template.
2301 So, we do use the partial ordering rules, at least for now.
2302 This extension can only serve to make invalid programs valid,
2303 so it's safe. And, there is strong anecdotal evidence that
2304 the committee intended the partial ordering rules to apply;
2305 the EDG front end has that behavior, and John Spicer claims
2306 that the committee simply forgot to delete the wording in
2307 [temp.expl.spec]. */
2310 {
2313 }
2314 }
2316 // Concepts allows multiple declarations of member functions
2317 // with the same signature. Like above, we need to rely on
2318 // on the partial ordering of those candidates to determine which
2319 // is the best.
2321 {
2323 {
2326 }
2327 }
2330 {
2337 else
2340 }
2344 {
2350 }
2352 /* We have one, and exactly one, match. */
2354 {
2358 // Propagate the candidate's constraints to the declaration.
2361 /* DECL is a re-declaration or partial instantiation of a template
2362 function. */
2365 /* It was a specialization of an ordinary member function in a
2366 template class. */
2368 }
2370 /* It was a specialization of a template. */
2373 {
2378 }
2379 else
2382 }
2384 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2385 but with the default argument values filled in from those in the
2386 TMPL_TYPES. */
2388 static tree
2390 tree tmpl_types)
2391 {
2392 tree new_spec_types;
2400 /* Substitute into the rest of the list. */
2401 new_spec_types =
2405 /* Add the default argument for this parameter. */
2408 new_spec_types);
2409 }
2411 /* DECL is an explicit specialization. Replicate default arguments
2412 from the template it specializes. (That way, code like:
2414 template <class T> void f(T = 3);
2415 template <> void f(double);
2416 void g () { f (); }
2418 works, as required.) An alternative approach would be to look up
2419 the correct default arguments at the call-site, but this approach
2420 is consistent with how implicit instantiations are handled. */
2422 static void
2424 {
2425 tree tmpl;
2426 tree spec_types;
2427 tree tmpl_types;
2428 tree new_spec_types;
2429 tree old_type;
2430 tree new_type;
2431 tree t;
2436 /* See if there's anything we need to do. */
2449 {
2450 /* Remove the this pointer, but remember the object's type for
2451 CV quals. */
2457 {
2458 /* DECL may contain more parameters than TMPL due to the extra
2459 in-charge parameter in constructors and destructors. */
2462 }
2464 {
2467 }
2468 }
2470 /* Compute the merged default arguments. */
2471 new_spec_types =
2474 /* Compute the new FUNCTION_TYPE. */
2476 {
2480 new_spec_types);
2483 /* Put the in-charge parameter back. */
2486 new_spec_types);
2490 new_spec_types);
2491 }
2492 else
2494 new_spec_types);
2504 }
2506 /* Return the number of template headers we expect to see for a definition
2507 or specialization of CTYPE or one of its non-template members. */
2509 int
2511 {
2515 {
2516 /* You're supposed to have one `template <...>' for every
2517 template class, but you don't need one for a full
2518 specialization. For example:
2520 template <class T> struct S{};
2521 template <> struct S<int> { void f(); };
2522 void S<int>::f () {}
2524 is correct; there shouldn't be a `template <>' for the
2525 definition of `S<int>::f'. */
2527 /* If CTYPE does not have template information of any
2528 kind, then it is not a template, nor is it nested
2529 within a template. */
2537 }
2540 }
2542 /* Do a simple sanity check on the template headers that precede the
2543 variable declaration DECL. */
2545 void
2547 {
2552 {
2555 "variable templates only available with "
2558 // Namespace-scope variable templates should have a template header.
2560 }
2562 {
2564 "too many template headers for %qD "
2570 "members of an explicitly specialized class are defined "
2572 }
2573 }
2575 /* An explicit specialization whose declarator-id or class-head-name is not
2576 qualified shall be declared in the nearest enclosing namespace of the
2577 template, or, if the namespace is inline (7.3.1), any namespace from its
2578 enclosing namespace set.
2580 If the name declared in the explicit instantiation is an unqualified name,
2581 the explicit instantiation shall appear in the namespace where its template
2582 is declared or, if that namespace is inline (7.3.1), any namespace from its
2583 enclosing namespace set. */
2585 void
2587 {
2592 {
2598 /* This was allowed in C++98, so only pedwarn. */
2600 "outside its namespace must use a nested-name-"
2602 }
2603 }
2605 /* Check to see if the function just declared, as indicated in
2606 DECLARATOR, and in DECL, is a specialization of a function
2607 template. We may also discover that the declaration is an explicit
2608 instantiation at this point.
2610 Returns DECL, or an equivalent declaration that should be used
2611 instead if all goes well. Issues an error message if something is
2612 amiss. Returns error_mark_node if the error is not easily
2613 recoverable.
2615 FLAGS is a bitmask consisting of the following flags:
2617 2: The function has a definition.
2618 4: The function is a friend.
2620 The TEMPLATE_COUNT is the number of references to qualifying
2621 template classes that appeared in the name of the function. For
2622 example, in
2624 template <class T> struct S { void f(); };
2625 void S<int>::f();
2627 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2628 classes are not counted in the TEMPLATE_COUNT, so that in
2630 template <class T> struct S {};
2631 template <> struct S<int> { void f(); }
2632 template <> void S<int>::f();
2634 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2635 invalid; there should be no template <>.)
2637 If the function is a specialization, it is marked as such via
2638 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2639 is set up correctly, and it is added to the list of specializations
2640 for that template. */
2642 tree
2644 tree decl,
2647 {
2656 tmpl_spec_kind tsk;
2659 {
2662 else
2664 }
2665 else
2669 {
2672 {
2675 }
2677 {
2679 /* This could be something like:
2681 template <class T> void f(T);
2682 class S { friend void f<>(int); } */
2684 else
2685 {
2686 /* This case handles bogus declarations like template <>
2687 template <class T> void f<int>(); */
2690 declarator);
2692 }
2693 }
2697 /* The error has already been reported in
2698 check_specialization_scope. */
2704 /* Fall through. */
2717 decl);
2720 else
2724 /* Fall through. */
2730 /* In cases like template<> constexpr bool v = true;
2731 We'll give an error in check_template_variable. */
2737 else
2743 {
2744 /* This case handles bogus declarations like template <>
2745 template <class T> void f<int>(); */
2749 declarator);
2751 {
2752 /* Partial specialization of variable template. */
2756 }
2760 else
2764 ok:;
2765 }
2768 /* This is a specialization of a member template, without
2769 specialization the containing class. Something like:
2771 template <class T> struct S {
2772 template <class U> void f (U);
2773 };
2774 template <> template <class U> void S<int>::f(U) {}
2776 That's a specialization -- but of the entire template. */
2782 }
2785 /* This doesn't apply to variable templates. */
2788 {
2792 {
2796 }
2797 }
2800 {
2805 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2807 {
2808 tree fns;
2813 else
2814 {
2815 /* If there is no class context, the explicit instantiation
2816 must be at namespace scope. */
2819 /* Find the namespace binding, using the declaration
2820 context. */
2824 /* If lookup fails, look for a friend declaration so we can
2825 give a better diagnostic. */
2831 {
2834 }
2835 }
2838 }
2844 {
2846 /* A specialization in class scope. This is invalid,
2847 but the error will already have been flagged by
2848 check_specialization_scope. */
2850 else
2851 {
2852 /* It's not valid to write an explicit instantiation in
2853 class scope, e.g.:
2855 class C { template void f(); }
2857 This case is caught by the parser. However, on
2858 something like:
2860 template class C { void f(); };
2862 (which is invalid) we can get here. The error will be
2863 issued later. */
2864 ;
2865 }
2868 }
2871 {
2872 // We'll match variable templates in start_decl.
2876 /* Find the list of functions in ctype that have the same
2877 name as the declared function. */
2883 {
2888 {
2889 /* From [temp.expl.spec]:
2891 If such an explicit specialization for the member
2892 of a class template names an implicitly-declared
2893 special member function (clause _special_), the
2894 program is ill-formed.
2896 Similar language is found in [temp.explicit]. */
2899 }
2902 }
2905 {
2909 }
2910 else
2911 {
2913 tree ovl;
2915 /* For a type-conversion operator, we cannot do a
2916 name-based lookup. We might be looking for `operator
2917 int' which will be a specialization of `operator T'.
2918 So, we find *all* the conversion operators, and then
2919 select from them. */
2927 {
2929 /* There are no more conversion functions. */
2932 /* Glue all these conversion functions together
2933 with those we already have. */
2935 }
2936 }
2939 {
2942 }
2943 else
2945 }
2947 /* Figure out what exactly is being specialized at this point.
2948 Note that for an explicit instantiation, even one for a
2949 member function, we cannot tell a priori whether the
2950 instantiation is for a member template, or just a member
2951 function of a template class. Even if a member template is
2952 being instantiated, the member template arguments may be
2953 elided if they can be deduced from the rest of the
2954 declaration. */
2957 member_specialization,
2958 template_count,
2959 tsk);
2962 /* We couldn't figure out what this declaration was
2963 specializing. */
2965 else
2966 {
2969 {
2971 "friend declaration %qD is not visible to "
2975 }
2983 {
2984 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2985 is done by do_decl_instantiation later. */
2991 {
2992 /* If TMPL is not the most general template (for
2993 example, if TMPL is a friend template that is
2994 injected into namespace scope), then there will
2995 be too many levels of TARGS. Remove some of them
2996 here. */
2998 tree new_targs;
3005 }
3008 }
3010 /* If we thought that the DECL was a member function, but it
3011 turns out to be specializing a static member function,
3012 make DECL a static member function as well. */
3018 /* If this is a specialization of a member template of a
3019 template class, we want to return the TEMPLATE_DECL, not
3020 the specialization of it. */
3022 {
3027 {
3028 tree parm;
3032 /* We want to use the argument list specified in the
3033 definition, not in the original declaration. */
3038 }
3041 }
3043 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3049 /* Inherit default function arguments from the template
3050 DECL is specializing. */
3054 /* This specialization has the same protection as the
3055 template it specializes. */
3059 /* 7.1.1-1 [dcl.stc]
3061 A storage-class-specifier shall not be specified in an
3062 explicit specialization...
3064 The parser rejects these, so unless action is taken here,
3065 explicit function specializations will always appear with
3066 global linkage.
3068 The action recommended by the C++ CWG in response to C++
3069 defect report 605 is to make the storage class and linkage
3070 of the explicit specialization match the templated function:
3072 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3073 */
3075 {
3079 /* A concept cannot be specialized. */
3081 {
3083 gen_tmpl);
3085 }
3087 /* This specialization has the same linkage and visibility as
3088 the function template it specializes. */
3091 {
3094 }
3097 {
3100 }
3101 }
3103 /* If DECL is a friend declaration, declared using an
3104 unqualified name, the namespace associated with DECL may
3105 have been set incorrectly. For example, in:
3107 template <typename T> void f(T);
3108 namespace N {
3109 struct S { friend void f<int>(int); }
3110 }
3112 we will have set the DECL_CONTEXT for the friend
3113 declaration to N, rather than to the global namespace. */
3118 /* This is not really a declaration of a specialization.
3119 It's just the name of an instantiation. But, it's not
3120 a request for an instantiation, either. */
3123 /* A specialization is not necessarily COMDAT. */
3129 /* If this is a full specialization, register it so that we can find
3130 it again. Partial specializations will be registered in
3131 process_partial_specialization. */
3136 /* A 'structor should already have clones. */
3142 }
3143 }
3146 }
3148 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3149 parameters. These are represented in the same format used for
3150 DECL_TEMPLATE_PARMS. */
3152 int
3154 {
3155 const_tree p1;
3156 const_tree p2;
3164 {
3176 {
3180 /* If either of the template parameters are invalid, assume
3181 they match for the sake of error recovery. */
3194 }
3195 }
3198 /* One set of parameters has more parameters lists than the
3199 other. */
3203 }
3205 /* Determine whether PARM is a parameter pack. */
3207 bool
3209 {
3210 /* Determine if we have a non-type template parameter pack. */
3217 /* If this is a list of template parameters, we could get a
3218 TYPE_DECL or a TEMPLATE_DECL. */
3222 /* Otherwise it must be a type template parameter. */
3226 }
3228 /* Determine if T is a function parameter pack. */
3230 bool
3232 {
3236 }
3238 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3239 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3241 tree
3243 {
3250 }
3252 /* Return true iff the function parameter PARAM_DECL was expanded
3253 from the function parameter pack PACK. */
3255 bool
3257 {
3262 /* The parameter pack and its pack arguments have the same
3263 DECL_PARM_INDEX. */
3265 }
3267 /* Determine whether ARGS describes a variadic template args list,
3268 i.e., one that is terminated by a template argument pack. */
3270 static bool
3272 {
3274 tree last_parm;
3288 }
3290 /* Generate a new name for the parameter pack name NAME (an
3291 IDENTIFIER_NODE) that incorporates its */
3293 static tree
3295 {
3296 /* Munge the name to include the parameter index. */
3297 #define NUMBUF_LEN 128
3311 }
3313 /* Return true if T is a primary function, class or alias template
3314 instantiation. */
3316 bool
3318 {
3332 }
3334 /* Return true if PARM is a template template parameter. */
3336 bool
3338 {
3340 }
3342 /* Return true iff PARM is a DECL representing a type template
3343 parameter. */
3345 bool
3347 {
3352 }
3354 /* Return the template parameters of T if T is a
3355 primary template instantiation, NULL otherwise. */
3357 tree
3359 {
3364 parms = INNERMOST_TEMPLATE_PARMS
3368 }
3370 /* Return the template parameters of the LEVELth level from the full list
3371 of template parameters PARMS. */
3373 tree
3375 {
3376 tree p;
3387 }
3389 /* Returns the template arguments of T if T is a template instantiation,
3390 NULL otherwise. */
3392 tree
3394 {
3402 }
3404 /* Return the argument pack elements of T if T is a template argument pack,
3405 NULL otherwise. */
3407 tree
3409 {
3415 }
3417 /* True iff FN is a function representing a built-in variadic parameter
3418 pack. */
3420 bool
3422 {
3432 }
3434 /* True iff CALL is a call to a function representing a built-in variadic
3435 parameter pack. */
3437 static bool
3439 {
3443 }
3445 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3447 static tree
3449 tree in_decl)
3450 {
3456 {
3458 {
3461 }
3466 }
3467 else
3468 {
3472 /* Calculate the largest value of len that won't make the size of the vec
3473 overflow an int. The compiler will exceed resource limits long before
3474 this, but it seems a decent place to diagnose. */
3478 {
3483 }
3491 }
3492 }
3494 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3495 CALL. */
3497 static tree
3499 tree in_decl)
3500 {
3510 }
3512 /* Structure used to track the progress of find_parameter_packs_r. */
3513 struct find_parameter_pack_data
3514 {
3515 /* TREE_LIST that will contain all of the parameter packs found by
3516 the traversal. */
3519 /* Set of AST nodes that have been visited by the traversal. */
3522 /* True iff we're making a type pack expansion. */
3524 };
3526 /* Identifies all of the argument packs that occur in a template
3527 argument and appends them to the TREE_LIST inside DATA, which is a
3528 find_parameter_pack_data structure. This is a subroutine of
3529 make_pack_expansion and uses_parameter_packs. */
3530 static tree
3532 {
3538 /* Handle type aliases/typedefs. */
3540 {
3547 }
3549 /* Identify whether this is a parameter pack or not. */
3551 {
3559 /* FALLTHRU */
3561 /* If the placeholder appears in the decl-specifier-seq of a function
3562 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3563 is a pack expansion, the invented template parameter is a template
3564 parameter pack. */
3574 {
3575 /* We don't want to walk into the type of a PARM_DECL,
3576 because we don't want to see the type parameter pack. */
3579 }
3582 /* Look through a lambda capture proxy to the field pack. */
3585 {
3591 }
3593 {
3595 find_parameter_packs_r,
3598 }
3610 /* Not a parameter pack. */
3612 }
3615 {
3616 /* Add this parameter pack to the list. */
3618 }
3624 /* This switch statement will return immediately if we don't find a
3625 parameter pack. */
3627 {
3632 /* Check the template itself. */
3635 /* Check the template arguments. */
3651 /* Fall through. */
3696 {
3697 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3698 type_pack_expansion_p to false so that any placeholders
3699 within the expression don't get marked as parameter packs. */
3707 }
3711 }
3714 }
3716 /* Determines if the expression or type T uses any parameter packs. */
3717 bool
3719 {
3728 }
3730 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3731 representation a base-class initializer into a parameter pack
3732 expansion. If all goes well, the resulting node will be an
3733 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3734 respectively. */
3735 tree
3737 {
3738 tree result;
3747 {
3748 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3749 class initializer. In this case, the TREE_PURPOSE will be a
3750 _TYPE node (representing the base class expansion we're
3751 initializing) and the TREE_VALUE will be a TREE_LIST
3752 containing the initialization arguments.
3754 The resulting expansion looks somewhat different from most
3755 expansions. Rather than returning just one _EXPANSION, we
3756 return a TREE_LIST whose TREE_PURPOSE is a
3757 TYPE_PACK_EXPANSION containing the bases that will be
3758 initialized. The TREE_VALUE will be identical to the
3759 original TREE_VALUE, which is a list of arguments that will
3760 be passed to each base. We do not introduce any new pack
3761 expansion nodes into the TREE_VALUE (although it is possible
3762 that some already exist), because the TREE_PURPOSE and
3763 TREE_VALUE all need to be expanded together with the same
3764 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3765 resulting TREE_PURPOSE will mention the parameter packs in
3766 both the bases and the arguments to the bases. */
3767 tree purpose;
3768 tree value;
3771 /* Determine which parameter packs will be used by the base
3772 class expansion. */
3781 {
3785 }
3788 {
3789 /* Collect the sets of parameter packs used in each of the
3790 initialization arguments. */
3792 {
3793 /* Determine which parameter packs will be expanded in this
3794 argument. */
3797 }
3798 }
3802 /* Create the pack expansion type for the base type. */
3807 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3808 they will rarely be compared to anything. */
3812 }
3817 /* Build the PACK_EXPANSION_* node. */
3818 result = for_types
3823 {
3824 /* Propagate type and const-expression information. */
3827 /* Mark this read now, since the expansion might be length 0. */
3829 }
3830 else
3831 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3832 they will rarely be compared to anything. */
3835 /* Determine which parameter packs will be expanded. */
3842 /* Make sure we found some parameter packs. */
3844 {
3847 else
3850 }
3856 }
3858 /* Checks T for any "bare" parameter packs, which have not yet been
3859 expanded, and issues an error if any are found. This operation can
3860 only be done on full expressions or types (e.g., an expression
3861 statement, "if" condition, etc.), because we could have expressions like:
3863 foo(f(g(h(args)))...)
3865 where "args" is a parameter pack. check_for_bare_parameter_packs
3866 should not be called for the subexpressions args, h(args),
3867 g(h(args)), or f(g(h(args))), because we would produce erroneous
3868 error messages.
3870 Returns TRUE and emits an error if there were bare parameter packs,
3871 returns FALSE otherwise. */
3872 bool
3874 {
3891 {
3895 {
3906 else
3911 else
3915 }
3918 }
3921 }
3923 /* Expand any parameter packs that occur in the template arguments in
3924 ARGS. */
3925 tree
3927 {
3936 /* First, determine if we need to expand anything, and the number of
3937 slots we'll need. */
3939 {
3944 {
3948 else
3950 }
3951 else
3952 {
3954 num_result_args++;
3955 }
3956 }
3958 /* If no expansion is necessary, we're done. */
3962 /* Expand arguments. */
3965 non_default_args_count =
3968 {
3971 {
3978 }
3979 else
3980 {
3983 }
3984 }
3988 }
3990 /* Checks if DECL shadows a template parameter.
3992 [temp.local]: A template-parameter shall not be redeclared within its
3993 scope (including nested scopes).
3995 Emits an error and returns TRUE if the DECL shadows a parameter,
3996 returns FALSE otherwise. */
3998 bool
4000 {
4001 tree olddecl;
4003 /* If we're not in a template, we can't possibly shadow a template
4004 parameter. */
4008 /* Figure out what we're shadowing. */
4012 /* If there's no previous binding for this name, we're not shadowing
4013 anything, let alone a template parameter. */
4017 /* If we're not shadowing a template parameter, we're done. Note
4018 that OLDDECL might be an OVERLOAD (or perhaps even an
4019 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4020 node. */
4024 /* We check for decl != olddecl to avoid bogus errors for using a
4025 name inside a class. We check TPFI to avoid duplicate errors for
4026 inline member templates. */
4032 /* Don't complain about the injected class name, as we've already
4033 complained about the class itself. */
4040 else
4045 }
4047 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4048 ORIG_LEVEL, DECL, and TYPE. */
4050 static tree
4054 tree decl,
4055 tree type)
4056 {
4067 }
4069 /* Find the canonical type parameter for the given template type
4070 parameter. Returns the canonical type parameter, which may be TYPE
4071 if no such parameter existed. */
4073 static tree
4075 {
4076 tree list;
4090 else
4091 {
4095 }
4096 }
4098 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4099 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4100 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4101 new one is created. */
4103 static tree
4105 tsubst_flags_t complain)
4106 {
4111 {
4130 /* Template template parameters need this. */
4132 {
4139 }
4140 }
4143 }
4145 /* Process information from new template parameter PARM and append it
4146 to the LIST being built. This new parameter is a non-type
4147 parameter iff IS_NON_TYPE is true. This new parameter is a
4148 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4149 is in PARM_LOC. */
4151 tree
4154 {
4163 {
4167 {
4171 else
4173 }
4176 }
4179 {
4185 {
4186 /* [temp.param]
4188 The top-level cv-qualifiers on the template-parameter are
4189 ignored when determining its type. */
4194 && !is_parameter_pack
4195 /* If we're in a nested template parameter list, the template
4196 template parameter could be a parameter pack. */
4198 {
4199 /* This template parameter is not a parameter pack, but it
4200 should be. Complain about "bare" parameter packs. */
4203 /* Recover by calling this a parameter pack. */
4205 }
4206 }
4208 /* A template parameter is not modifiable. */
4217 processing_template_decl,
4222 }
4223 else
4224 {
4225 tree t;
4229 {
4231 /* This is for distinguishing between real templates and template
4232 template parameters */
4236 }
4237 else
4238 {
4240 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4243 }
4250 processing_template_decl,
4254 }
4258 /* Build requirements for the type/template parameter.
4259 This must be done after SET_DECL_TEMPLATE_PARM_P or
4260 process_template_parm could fail. */
4265 /* Build the parameter node linking the parameter declaration,
4266 its default argument (if any), and its constraints (if any). */
4271 }
4273 /* The end of a template parameter list has been reached. Process the
4274 tree list into a parameter vector, converting each parameter into a more
4275 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4276 as PARM_DECLs. */
4278 tree
4280 {
4285 /* Pop the dummy parameter level and add the real one. */
4288 current_template_parms
4293 {
4297 }
4302 }
4304 // Explicitly indicate the end of the template parameter list. We assume
4305 // that the current template parameters have been constructed and/or
4306 // managed explicitly, as when creating new template template parameters
4307 // from a shorthand constraint.
4308 void
4310 {
4312 }
4314 /* end_template_decl is called after a template declaration is seen. */
4316 void
4318 {
4324 /* This matches the pushlevel in begin_template_parm_list. */
4329 }
4331 /* Takes a TREE_LIST representing a template parameter and convert it
4332 into an argument suitable to be passed to the type substitution
4333 functions. Note that If the TREE_LIST contains an error_mark
4334 node, the returned argument is error_mark_node. */
4336 tree
4338 {
4351 {
4355 {
4356 /* Turn this argument into a TYPE_ARGUMENT_PACK
4357 with a single element, which expands T. */
4366 }
4367 }
4368 else
4369 {
4373 {
4374 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4375 with a single element, which expands T. */
4385 }
4386 else
4388 }
4390 }
4392 /* Given a single level of template parameters (a TREE_VEC), return it
4393 as a set of template arguments. */
4395 static tree
4397 {
4407 }
4409 /* Given a set of template parameters, return them as a set of template
4410 arguments. The template parameters are represented as a TREE_VEC, in
4411 the form documented in cp-tree.h for template arguments. */
4413 static tree
4415 {
4416 tree header;
4421 /* If there is only one level of template parameters, we do not
4422 create a TREE_VEC of TREE_VECs. Instead, we return a single
4423 TREE_VEC containing the arguments. */
4428 {
4433 else
4435 }
4438 }
4440 /* Within the declaration of a template, return the currently active
4441 template parameters as an argument TREE_VEC. */
4443 static tree
4445 {
4447 }
4449 /* Update the declared TYPE by doing any lookups which were thought to be
4450 dependent, but are not now that we know the SCOPE of the declarator. */
4452 tree
4454 {
4465 /* Don't bother building up the args in this case. */
4467 {
4468 /* tsubst in the args corresponding to the template parameters,
4469 including auto if present. Most things will be unchanged, but
4470 make_typename_type and tsubst_qualified_id will resolve
4471 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4474 tree pushed;
4476 {
4480 }
4485 }
4491 {
4494 else
4496 }
4498 }
4500 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4501 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4502 the new template is a member template. */
4504 tree
4506 {
4514 }
4516 struct template_parm_data
4517 {
4518 /* The level of the template parameters we are currently
4519 processing. */
4522 /* The index of the specialization argument we are currently
4523 processing. */
4526 /* An array whose size is the number of template parameters. The
4527 elements are nonzero if the parameter has been used in any one
4528 of the arguments processed so far. */
4531 /* An array whose size is the number of template arguments. The
4532 elements are nonzero if the argument makes use of template
4533 parameters of this level. */
4535 };
4537 /* Subroutine of push_template_decl used to see if each template
4538 parameter in a partial specialization is used in the explicit
4539 argument list. If T is of the LEVEL given in DATA (which is
4540 treated as a template_parm_data*), then DATA->PARMS is marked
4541 appropriately. */
4543 static int
4545 {
4553 {
4556 }
4558 /* In C++17 the type of a non-type argument is a deduced context. */
4563 data,
4564 NULL,
4567 /* Return zero so that for_each_template_parm will continue the
4568 traversal of the tree; we want to mark *every* template parm. */
4570 }
4572 /* Process the partial specialization DECL. */
4574 static tree
4576 {
4583 tree inner_parms;
4584 tree inst;
4594 /* A concept cannot be specialized. */
4596 {
4599 }
4604 /* We check that each of the template parameters given in the
4605 partial specialization is used in the argument list to the
4606 specialization. For example:
4608 template <class T> struct S;
4609 template <class T> struct S<T*>;
4611 The second declaration is OK because `T*' uses the template
4612 parameter T, whereas
4614 template <class T> struct S<int>;
4616 is no good. Even trickier is:
4618 template <class T>
4619 struct S1
4620 {
4621 template <class U>
4622 struct S2;
4623 template <class U>
4624 struct S2<T>;
4625 };
4627 The S2<T> declaration is actually invalid; it is a
4628 full-specialization. Of course,
4630 template <class U>
4631 struct S2<T (*)(U)>;
4633 or some such would have been OK. */
4641 {
4646 NULL,
4648 }
4651 {
4652 /* One of the template parms was not used in a deduced context in the
4653 specialization. */
4655 {
4659 }
4663 }
4668 /* [temp.class.spec]
4670 The argument list of the specialization shall not be identical to
4671 the implicit argument list of the primary template. */
4672 tree main_args
4675 && (!flag_concepts
4678 {
4682 else
4686 }
4688 /* A partial specialization that replaces multiple parameters of the
4689 primary template with a pack expansion is less specialized for those
4690 parameters. */
4692 {
4694 "primary template because it replaces multiple parameters "
4697 /* Avoid crash in process_partial_specialization. */
4699 }
4701 /* If we aren't in a dependent class, we can actually try deduction. */
4703 /* FIXME we should be able to handle a partial specialization of a
4704 partial instantiation, but currently we can't (c++/41727). */
4707 {
4711 maintmpl);
4712 }
4714 /* [temp.class.spec]
4716 A partially specialized non-type argument expression shall not
4717 involve template parameters of the partial specialization except
4718 when the argument expression is a simple identifier.
4720 The type of a template parameter corresponding to a specialized
4721 non-type argument shall not be dependent on a parameter of the
4722 specialization.
4724 Also, we verify that pack expansions only occur at the
4725 end of the argument list. */
4729 {
4736 {
4737 /* Extract the arguments from the argument pack. We'll be
4738 iterating over these in the following loop. */
4741 }
4744 {
4746 /* Get the Jth argument in the parameter pack. */
4750 {
4751 /* Pack expansions must come at the end of the
4752 argument list. */
4755 {
4759 else
4762 }
4763 }
4766 /* We only care about the pattern. */
4772 /* This next two lines are the `argument expression is not just a
4773 simple identifier' condition and also the `specialized
4774 non-type argument' bit. */
4778 {
4782 arg);
4783 else
4784 {
4785 /* Look at the corresponding template parameter,
4786 marking which template parameters its type depends
4787 upon. */
4791 {
4792 /* We haven't yet initialized TPD2. Do so now. */
4794 /* The number of parameters here is the number in the
4795 main template, which, as checked in the assertion
4796 above, is NARGS. */
4800 }
4802 /* Mark the template parameters. But this time, we're
4803 looking for the template parameters of the main
4804 template, not in the specialization. */
4811 NULL,
4815 {
4816 /* The type depended on some template parameters.
4817 If they are fully specialized in the
4818 specialization, that's OK. */
4827 "type %qT of template argument %qE depends "
4829 "type %qT of template argument %qE depends "
4831 type,
4832 arg);
4833 }
4834 }
4835 }
4836 }
4837 }
4839 /* We should only get here once. */
4843 // Build the template decl.
4852 /* Give template template parms a DECL_CONTEXT of the template
4853 for which they are a parameter. */
4855 {
4859 }
4862 /* We didn't register this in check_explicit_specialization so we could
4863 wait until the constraints were set. */
4865 else
4875 {
4881 {
4889 "declaration of %qD ambiguates earlier template "
4893 "partial specialization of %qD after instantiation "
4895 }
4896 }
4899 }
4901 /* PARM is a template parameter of some form; return the corresponding
4902 TEMPLATE_PARM_INDEX. */
4904 static tree
4906 {
4919 }
4921 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4922 parameter packs used by the template parameter PARM. */
4924 static void
4926 {
4927 /* A type parm can't refer to another parm. */
4931 {
4935 }
4942 }
4944 /* PARM is a template parameter pack. Return any parameter packs used in
4945 its type or the type of any of its template parameters. If there are
4946 any such packs, it will be instantiated into a fixed template parameter
4947 list by partial instantiation rather than be fully deduced. */
4949 tree
4951 {
4952 /* This can only be true in a member template. */
4955 /* This can only be true for a parameter pack. */
4958 /* A type parm can't refer to another parm. */
4972 }
4974 /* Check that a template declaration's use of default arguments and
4975 parameter packs is not invalid. Here, PARMS are the template
4976 parameters. IS_PRIMARY is true if DECL is the thing declared by
4977 a primary template. IS_PARTIAL is true if DECL is a partial
4978 specialization.
4980 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4981 declaration (but not a definition); 1 indicates a declaration, 2
4982 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4983 emitted for extraneous default arguments.
4985 Returns TRUE if there were no errors found, FALSE otherwise. */
4987 bool
4990 {
4993 tree parm_level;
4996 /* [temp.param]
4998 A default template-argument shall not be specified in a
4999 function template declaration or a function template definition, nor
5000 in the template-parameter-list of the definition of a member of a
5001 class template. */
5005 /* You can't have a function template declaration in a local
5006 scope, nor you can you define a member of a class template in a
5007 local scope. */
5015 /* A lambda doesn't have an explicit declaration; don't complain
5016 about the parms of the enclosing class. */
5023 /* If this is either a friend defined in the scope of the class
5024 or a member function. */
5030 /* And, if it was a member function, it really was defined in
5031 the scope of the class. */
5034 /* We already checked these parameters when the template was
5035 declared, so there's no need to do it again now. This function
5036 was defined in class scope, but we're processing its body now
5037 that the class is complete. */
5040 /* Core issue 226 (C++0x only): the following only applies to class
5041 templates. */
5044 {
5045 /* [temp.param]
5047 If a template-parameter has a default template-argument, all
5048 subsequent template-parameters shall have a default
5049 template-argument supplied. */
5051 {
5058 {
5068 {
5070 /* For better subsequent error-recovery, we indicate that
5071 there should have been a default argument. */
5074 }
5076 && !is_friend_decl
5077 /* Don't complain about an enclosing partial
5078 specialization. */
5083 /* A fixed parameter pack will be partially
5084 instantiated into a fixed length list. */
5086 {
5087 /* A primary class template can only have one
5088 parameter pack, at the end of the template
5089 parameter list. */
5097 }
5098 }
5099 }
5100 }
5103 || is_partial
5104 || !is_primary
5106 /* For an ordinary class template, default template arguments are
5107 allowed at the innermost level, e.g.:
5108 template <class T = int>
5109 struct S {};
5110 but, in a partial specialization, they're not allowed even
5111 there, as we have in [temp.class.spec]:
5113 The template parameter list of a specialization shall not
5114 contain default template argument values.
5116 So, for a partial specialization, or for a function template
5117 (in C++98/C++03), we look at all of them. */
5118 ;
5119 else
5120 /* But, for a primary class template that is not a partial
5121 specialization we look at all template parameters except the
5122 innermost ones. */
5125 /* Figure out what error message to issue. */
5140 else
5141 /* Per [temp.param]/9, "A default template-argument shall not be
5142 specified in the template-parameter-lists of the definition of
5143 a member of a class template that appears outside of the member's
5144 class.", thus if we aren't handling a member of a class template
5145 there is no need to examine the parameters. */
5149 /* If we're inside a class definition, there's no need to
5150 examine the parameters to the class itself. On the one
5151 hand, they will be checked when the class is defined, and,
5152 on the other, default arguments are valid in things like:
5153 template <class T = double>
5154 struct S { template <class U> void f(U); };
5155 Here the default argument for `S' has no bearing on the
5156 declaration of `f'. */
5158 else
5159 /* Check everything. */
5165 {
5172 {
5177 {
5179 {
5186 }
5188 /* Clear out the default argument so that we are not
5189 confused later. */
5191 }
5192 }
5194 /* At this point, if we're still interested in issuing messages,
5195 they must apply to classes surrounding the object declared. */
5199 }
5202 }
5204 /* Worker for push_template_decl_real, called via
5205 for_each_template_parm. DATA is really an int, indicating the
5206 level of the parameters we are interested in. If T is a template
5207 parameter of that level, return nonzero. */
5209 static int
5211 {
5217 else
5220 }
5222 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5223 DATA is really an int, indicating the innermost outer level of parameters.
5224 If T is a template parameter of that level or further out, return
5225 nonzero. */
5227 static int
5229 {
5235 else
5238 }
5240 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5241 parameters given by current_template_args, or reuses a
5242 previously existing one, if appropriate. Returns the DECL, or an
5243 equivalent one, if it is replaced via a call to duplicate_decls.
5245 If IS_FRIEND is true, DECL is a friend declaration. */
5247 tree
5249 {
5250 tree tmpl;
5251 tree args;
5252 tree info;
5253 tree ctx;
5257 /* True if the template is a member template, in the sense of
5258 [temp.mem]. */
5264 /* See if this is a partial specialization. */
5277 /* For a friend, we want the context of the friend function, not
5278 the type of which it is a friend. */
5282 /* In the case of a virtual function, we want the class in which
5283 it is defined. */
5285 else
5286 /* Otherwise, if we're currently defining some class, the DECL
5287 is assumed to be a member of the class. */
5296 /* See if this is a primary template. */
5299 /* A friend template that specifies a class context, i.e.
5300 template <typename T> friend void A<T>::f();
5301 is not primary. */
5306 else
5310 {
5317 {
5320 }
5322 {
5324 {
5327 }
5329 {
5330 /* [temp.mem]
5332 A destructor shall not be a member template. */
5335 }
5342 {
5343 /* [basic.stc.dynamic.allocation]
5345 An allocation function can be a function
5346 template. ... Template allocation functions shall
5347 have two or more parameters. */
5350 }
5351 }
5354 {
5355 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5358 {
5364 }
5365 }
5368 /* alias-declaration */
5372 else
5373 {
5376 }
5377 }
5379 /* Check to see that the rules regarding the use of default
5380 arguments are not being violated. */
5384 /* Ensure that there are no parameter packs in the type of this
5385 declaration that have not been expanded. */
5387 {
5388 /* Check each of the arguments individually to see if there are
5389 any bare parameter packs. */
5395 {
5398 {
5399 /* This is a PARM_DECL that contains unexpanded parameter
5400 packs. We have already complained about this in the
5401 check_for_bare_parameter_packs call, so just replace
5402 these types with ERROR_MARK_NODE. */
5405 }
5409 }
5411 /* Check for bare parameter packs in the return type and the
5412 exception specifiers. */
5414 /* Errors were already issued, set return type to int
5415 as the frontend doesn't expect error_mark_node as
5416 the return type. */
5420 }
5425 {
5428 }
5441 {
5446 /* If DECL is a TYPE_DECL for a class-template, then there won't
5447 be DECL_LANG_SPECIFIC. The information equivalent to
5448 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5452 {
5453 /* Since a template declaration already existed for this
5454 class-type, we must be redeclaring it here. Make sure
5455 that the redeclaration is valid. */
5457 current_template_parms,
5459 /* We don't need to create a new TEMPLATE_DECL; just use the
5460 one we already had. */
5462 }
5463 else
5464 {
5466 member_template_p);
5471 {
5472 /* A specialization of a member template of a template
5473 class. */
5477 }
5478 }
5479 }
5480 else
5481 {
5487 {
5490 }
5498 {
5499 tree new_tmpl;
5501 /* The declaration is a specialization of a member
5502 template, declared outside the class. Therefore, the
5503 innermost template arguments will be NULL, so we
5504 replace them with the arguments determined by the
5505 earlier call to check_explicit_specialization. */
5508 new_tmpl
5510 member_template_p);
5520 args,
5523 }
5525 /* Make sure the template headers we got make sense. */
5530 {
5535 }
5536 else
5538 {
5543 {
5547 else
5551 /* Avoid crash in import_export_decl. */
5554 }
5559 /* Can happen in erroneous input. */
5561 else
5563 }
5565 /* Check that the parms are used in the appropriate qualifying scopes
5566 in the declarator. */
5570 {
5576 /* Avoid crash in import_export_decl. */
5579 }
5580 }
5585 /* Push template declarations for global functions and types. Note
5586 that we do not try to push a global template friend declared in a
5587 template class; such a thing may well depend on the template
5588 parameters of the class. */
5591 {
5596 /* Hide template friend classes that haven't been declared yet. */
5598 {
5601 }
5602 }
5605 {
5611 {
5614 /* It is a conversion operator. See if the type converted to
5615 depends on innermost template operands. */
5618 depth))
5620 }
5622 /* Give template template parms a DECL_CONTEXT of the template
5623 for which they are a parameter. */
5626 {
5630 }
5636 }
5638 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5639 back to its most general template. If TMPL is a specialization,
5640 ARGS may only have the innermost set of arguments. Add the missing
5641 argument levels if necessary. */
5649 else
5650 {
5655 }
5658 && !is_friend
5661 /* Set DECL_COMDAT on template instantiations; if we force
5662 them to be emitted by explicit instantiation or -frepo,
5663 mark_needed will tell cgraph to do the right thing. */
5667 }
5669 tree
5671 {
5673 }
5675 /* FN is an inheriting constructor that inherits from the constructor
5676 template INHERITED; turn FN into a constructor template with a matching
5677 template header. */
5679 tree
5681 {
5682 tree inner_parms
5685 tree parms
5696 }
5698 /* Called when a class template TYPE is redeclared with the indicated
5699 template PARMS, e.g.:
5701 template <class T> struct S;
5702 template <class T> struct S {}; */
5704 bool
5706 {
5707 tree tmpl;
5708 tree tmpl_parms;
5712 {
5715 }
5719 /* The type is nested in some template class. Nothing to worry
5720 about here; there are no new template parameters for the nested
5721 type. */
5725 {
5727 tmpl);
5729 }
5735 {
5745 }
5748 {
5749 tree tmpl_parm;
5750 tree parm;
5751 tree tmpl_default;
5752 tree parm_default;
5766 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5767 TEMPLATE_DECL. */
5777 {
5781 }
5784 {
5785 /* We have in [temp.param]:
5787 A template-parameter may not be given default arguments
5788 by two different declarations in the same scope. */
5793 }
5796 /* Update the previous template parameters (which are the ones
5797 that will really count) with the new default value. */
5800 /* Update the new parameters, too; they'll be used as the
5801 parameters for any members. */
5804 /* Give each template template parm in this redeclaration a
5805 DECL_CONTEXT of the template for which they are a parameter. */
5807 {
5810 }
5814 }
5816 // Cannot redeclare a class template with a different set of constraints.
5818 {
5823 }
5826 }
5828 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5829 to be used when the caller has already checked
5830 (processing_template_decl
5831 && !instantiation_dependent_expression_p (expr)
5832 && potential_constant_expression (expr))
5833 and cleared processing_template_decl. */
5835 tree
5837 {
5840 complain,
5844 }
5846 /* Simplify EXPR if it is a non-dependent expression. Returns the
5847 (possibly simplified) expression. */
5849 tree
5851 {
5855 /* If we're in a template, but EXPR isn't value dependent, simplify
5856 it. We're supposed to treat:
5858 template <typename T> void f(T[1 + 1]);
5859 template <typename T> void f(T[2]);
5861 as two declarations of the same function, for example. */
5864 {
5865 processing_template_decl_sentinel s;
5867 }
5869 }
5871 tree
5873 {
5875 }
5877 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5878 an uninstantiated expression. */
5880 tree
5882 {
5886 {
5889 else
5890 {
5891 processing_template_decl_sentinel s;
5893 }
5894 }
5896 }
5898 /* True iff T is a specialization of a variable template. */
5900 bool
5902 {
5907 }
5909 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5910 template declaration, or a TYPE_DECL for an alias declaration. */
5912 bool
5914 {
5922 }
5924 /* Return TRUE iff T is a specialization of an alias template. */
5926 bool
5928 {
5929 /* It's an alias template specialization if it's an alias and its
5930 TYPE_NAME is a specialization of a primary template. */
5936 }
5938 /* An alias template is complex from a SFINAE perspective if a template-id
5939 using that alias can be ill-formed when the expansion is not, as with
5940 the void_t template. We determine this by checking whether the
5941 expansion for the alias template uses all its template parameters. */
5943 struct uses_all_template_parms_data
5944 {
5947 };
5949 static int
5951 {
5959 }
5961 static bool
5963 {
5978 }
5980 /* Return TRUE iff T is a specialization of a complex alias template with
5981 dependent template-arguments. */
5983 bool
5985 {
5998 }
6000 /* Return the number of innermost template parameters in TMPL. */
6002 static int
6004 {
6007 }
6009 /* Return either TMPL or another template that it is equivalent to under DR
6010 1286: An alias that just changes the name of a template is equivalent to
6011 the other template. */
6013 static tree
6015 {
6018 {
6019 /* Determine if the alias is equivalent to an underlying template. */
6031 tree alias_args = INNERMOST_TEMPLATE_ARGS
6036 /* Alias is equivalent. Strip it and repeat. */
6038 }
6041 }
6043 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6044 must be a reference-to-function or a pointer-to-function type, as specified
6045 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6046 and check that the resulting function has external linkage. */
6048 static tree
6050 tsubst_flags_t complain)
6051 {
6054 linkage_kind linkage;
6069 /* [temp.arg.nontype]/1
6071 A template-argument for a non-type, non-template template-parameter
6072 shall be one of:
6073 [...]
6074 -- the address of an object or function with external [C++11: or
6075 internal] linkage. */
6078 {
6080 {
6086 else
6089 }
6091 }
6095 {
6097 {
6102 else
6106 }
6108 }
6110 accept:
6117 }
6119 /* Subroutine of convert_nontype_argument.
6120 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6121 Emit an error otherwise. */
6123 static bool
6125 tsubst_flags_t complain)
6126 {
6137 {
6141 }
6143 }
6145 /* Returns TRUE iff the address of OP is value-dependent.
6147 14.6.2.4 [temp.dep.temp]:
6148 A non-integral non-type template-argument is dependent if its type is
6149 dependent or it has either of the following forms
6150 qualified-id
6151 & qualified-id
6152 and contains a nested-name-specifier which specifies a class-name that
6153 names a dependent type.
6155 We generalize this to just say that the address of a member of a
6156 dependent class is value-dependent; the above doesn't cover the
6157 address of a static data member named with an unqualified-id. */
6159 static bool
6161 {
6162 /* We could use get_inner_reference here, but there's no need;
6163 this is only relevant for template non-type arguments, which
6164 can only be expressed as &id-expression. */
6166 {
6170 }
6173 }
6175 /* The next set of functions are used for providing helpful explanatory
6176 diagnostics for failed overload resolution. Their messages should be
6177 indented by two spaces for consistency with the messages in
6178 call.c */
6180 static int
6182 {
6184 }
6186 /* Other failure functions should call this one, to provide a single function
6187 for setting a breakpoint on. */
6189 static int
6191 {
6193 }
6195 static int
6197 {
6202 }
6204 static int
6206 {
6212 }
6214 static int
6216 {
6220 }
6222 static int
6224 {
6227 " template parameter %qD is not a parameter pack, but "
6231 }
6233 static int
6235 {
6238 " template argument %qE does not match "
6242 }
6244 static int
6246 {
6250 }
6252 static int
6254 {
6260 }
6262 static int
6264 {
6266 {
6271 else
6273 " deduced conflicting values for non-type parameter "
6275 }
6277 }
6279 static int
6281 {
6284 " variable-sized array type %qT is not "
6286 arg);
6288 }
6290 static int
6292 {
6296 arg);
6298 }
6300 static int
6302 {
6304 {
6310 else
6315 }
6317 }
6319 static int
6321 {
6323 }
6325 static int
6328 {
6330 }
6332 static int
6335 {
6341 }
6343 static int
6346 {
6349 {
6357 }
6359 }
6361 static int
6363 {
6366 " template parameters of a template template argument are "
6369 }
6371 static int
6373 {
6379 }
6381 static int
6383 {
6388 }
6390 static int
6392 {
6396 arg);
6398 }
6400 /* Attempt to convert the non-type template parameter EXPR to the
6401 indicated TYPE. If the conversion is successful, return the
6402 converted value. If the conversion is unsuccessful, return
6403 NULL_TREE if we issued an error message, or error_mark_node if we
6404 did not. We issue error messages for out-and-out bad template
6405 parameters, but not simply because the conversion failed, since we
6406 might be just trying to do argument deduction. Both TYPE and EXPR
6407 must be non-dependent.
6409 The conversion follows the special rules described in
6410 [temp.arg.nontype], and it is much more strict than an implicit
6411 conversion.
6413 This function is called twice for each template argument (see
6414 lookup_template_class for a more accurate description of this
6415 problem). This means that we need to handle expressions which
6416 are not valid in a C++ source, but can be created from the
6417 first call (for instance, casts to perform conversions). These
6418 hacks can go away after we fix the double coercion problem. */
6420 static tree
6422 {
6423 tree expr_type;
6425 /* Detect immediately string literals as invalid non-type argument.
6426 This special-case is not needed for correctness (we would easily
6427 catch this later), but only to provide better diagnostic for this
6428 common user mistake. As suggested by DR 100, we do not mention
6429 linkage issues in the diagnostic as this is not the point. */
6430 /* FIXME we're making this OK. */
6432 {
6438 }
6440 /* Add the ADDR_EXPR now for the benefit of
6441 value_dependent_expression_p. */
6444 {
6448 }
6450 /* If we are in a template, EXPR may be non-dependent, but still
6451 have a syntactic, rather than semantic, form. For example, EXPR
6452 might be a SCOPE_REF, rather than the VAR_DECL to which the
6453 SCOPE_REF refers. Preserving the qualifying scope is necessary
6454 so that access checking can be performed when the template is
6455 instantiated -- but here we need the resolved form so that we can
6456 convert the argument. */
6469 else
6472 /* If the argument is non-dependent, perform any conversions in
6473 non-dependent context as well. */
6481 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6482 to a non-type argument of "nullptr". */
6486 /* In C++11, integral or enumeration non-type template arguments can be
6487 arbitrary constant expressions. Pointer and pointer to
6488 member arguments can be general constant expressions that evaluate
6489 to a null value, but otherwise still need to be of a specific form. */
6491 {
6493 /* A PTRMEM_CST is already constant, and a valid template
6494 argument for a parameter of pointer to member type, we just want
6495 to leave it in that form rather than lower it to a
6500 {
6504 {
6508 }
6509 }
6511 {
6516 }
6517 }
6519 /* HACK: Due to double coercion, we can get a
6520 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6521 which is the tree that we built on the first call (see
6522 below when coercing to reference to object or to reference to
6523 function). We just strip everything and get to the arg.
6524 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6525 for examples. */
6527 {
6533 {
6534 /* ??? Maybe we could use convert_from_reference here, but we
6535 would need to relax its constraints because the NOP_EXPR
6536 could actually change the type to something more cv-qualified,
6537 and this is not folded by convert_from_reference. */
6542 && (same_type_ignoring_top_level_qualifiers_p
6545 {
6548 }
6549 }
6550 }
6552 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6553 parameter is a pointer to object, through decay and
6554 qualification conversion. Let's strip everything. */
6556 {
6561 {
6562 /* Skip the ADDR_EXPR only if it is part of the decay for
6563 an array. Otherwise, it is part of the original argument
6564 in the source code. */
6569 }
6570 }
6572 /* [temp.arg.nontype]/5, bullet 1
6574 For a non-type template-parameter of integral or enumeration type,
6575 integral promotions (_conv.prom_) and integral conversions
6576 (_conv.integral_) are applied. */
6578 {
6587 /* Notice that there are constant expressions like '4 % 0' which
6588 do not fold into integer constants. */
6591 {
6593 {
6604 /* else cxx_constant_value complained but gave us
6605 a real constant, so go ahead. */
6607 }
6608 else
6610 }
6612 /* Avoid typedef problems. */
6615 }
6616 /* [temp.arg.nontype]/5, bullet 2
6618 For a non-type template-parameter of type pointer to object,
6619 qualification conversions (_conv.qual_) and the array-to-pointer
6620 conversion (_conv.array_) are applied. */
6622 {
6623 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6625 A template-argument for a non-type, non-template template-parameter
6626 shall be one of: [...]
6628 -- the name of a non-type template-parameter;
6629 -- the address of an object or function with external linkage, [...]
6630 expressed as "& id-expression" where the & is optional if the name
6631 refers to a function or array, or if the corresponding
6632 template-parameter is a reference.
6634 Here, we do not care about functions, as they are invalid anyway
6635 for a parameter of type pointer-to-object. */
6638 /* Non-type template parameters are OK. */
6639 ;
6644 {
6646 {
6649 "because %qD is a variable, not the address of "
6652 }
6654 {
6660 }
6661 /* Other values, like integer constants, might be valid
6662 non-type arguments of some other type. */
6664 }
6665 else
6666 {
6667 tree decl;
6672 {
6677 }
6679 {
6685 }
6687 {
6692 }
6693 }
6702 }
6703 /* [temp.arg.nontype]/5, bullet 3
6705 For a non-type template-parameter of type reference to object, no
6706 conversions apply. The type referred to by the reference may be more
6707 cv-qualified than the (otherwise identical) type of the
6708 template-argument. The template-parameter is bound directly to the
6709 template-argument, which must be an lvalue. */
6711 {
6713 expr_type))
6717 {
6722 }
6725 {
6730 }
6732 /* [temp.arg.nontype]/1
6734 A template-argument for a non-type, non-template template-parameter
6735 shall be one of: [...]
6737 -- the address of an object or function with external linkage. */
6740 {
6743 {
6746 "because a reference variable does not have a constant "
6749 }
6750 }
6753 {
6755 {
6761 }
6763 /* DR 1155 allows internal linkage in C++11 and up. */
6766 {
6772 }
6775 }
6776 }
6777 /* [temp.arg.nontype]/5, bullet 4
6779 For a non-type template-parameter of type pointer to function, only
6780 the function-to-pointer conversion (_conv.func_) is applied. If the
6781 template-argument represents a set of overloaded functions (or a
6782 pointer to such), the matching function is selected from the set
6783 (_over.over_). */
6785 {
6786 /* If the argument is a template-id, we might not have enough
6787 context information to decay the pointer. */
6789 {
6793 }
6796 /* Null pointer values are OK in C++11. */
6802 }
6803 /* [temp.arg.nontype]/5, bullet 5
6805 For a non-type template-parameter of type reference to function, no
6806 conversions apply. If the template-argument represents a set of
6807 overloaded functions, the matching function is selected from the set
6808 (_over.over_). */
6810 {
6812 {
6814 {
6819 }
6821 }
6826 }
6827 /* [temp.arg.nontype]/5, bullet 6
6829 For a non-type template-parameter of type pointer to member function,
6830 no conversions apply. If the template-argument represents a set of
6831 overloaded member functions, the matching member function is selected
6832 from the set (_over.over_). */
6834 {
6839 /* [temp.arg.nontype] bullet 1 says the pointer to member
6840 expression must be a pointer-to-member constant. */
6845 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6846 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6850 /* There is no way to disable standard conversions in
6851 resolve_address_of_overloaded_function (called by
6852 instantiate_type). It is possible that the call succeeded by
6853 converting &B::I to &D::I (where B is a base of D), so we need
6854 to reject this conversion here.
6856 Actually, even if there was a way to disable standard conversions,
6857 it would still be better to reject them here so that we can
6858 provide a superior diagnostic. */
6860 {
6862 {
6866 /* If we are just one standard conversion off, explain. */
6870 }
6872 }
6873 }
6874 /* [temp.arg.nontype]/5, bullet 7
6876 For a non-type template-parameter of type pointer to data member,
6877 qualification conversions (_conv.qual_) are applied. */
6879 {
6880 /* [temp.arg.nontype] bullet 1 says the pointer to member
6881 expression must be a pointer-to-member constant. */
6889 }
6891 {
6893 {
6898 }
6900 }
6901 /* A template non-type parameter must be one of the above. */
6902 else
6905 /* Sanity check: did we actually convert the argument to the
6906 right type? */
6910 }
6912 /* Subroutine of coerce_template_template_parms, which returns 1 if
6913 PARM_PARM and ARG_PARM match using the rule for the template
6914 parameters of template template parameters. Both PARM and ARG are
6915 template parameters; the rest of the arguments are the same as for
6916 coerce_template_template_parms.
6917 */
6918 static int
6920 tree arg,
6921 tsubst_flags_t complain,
6922 tree in_decl,
6923 tree outer_args)
6924 {
6933 {
6935 /* We encounter instantiations of templates like
6936 template <template <template <class> class> class TT>
6937 class C; */
6938 {
6945 }
6946 /* Fall through. */
6951 /* Argument is a parameter pack but parameter is not. */
6956 /* The tsubst call is used to handle cases such as
6958 template <int> class C {};
6959 template <class T, template <T> class TT> class D {};
6960 D<int, C> d;
6962 i.e. the parameter list of TT depends on earlier parameters. */
6964 {
6969 }
6973 /* Argument is a parameter pack but parameter is not. */
6980 }
6983 }
6985 /* Coerce template argument list ARGLIST for use with template
6986 template-parameter TEMPL. */
6988 static tree
6990 tsubst_flags_t complain)
6991 {
6992 /* Consider an example where a template template parameter declared as
6994 template <class T, class U = std::allocator<T> > class TT
6996 The template parameter level of T and U are one level larger than
6997 of TT. To proper process the default argument of U, say when an
6998 instantiation `TT<int>' is seen, we need to build the full
6999 arguments containing {int} as the innermost level. Outer levels,
7000 available when not appearing as default template argument, can be
7001 obtained from the arguments of the enclosing template.
7003 Suppose that TT is later substituted with std::vector. The above
7004 instantiation is `TT<int, std::allocator<T> >' with TT at
7005 level 1, and T at level 2, while the template arguments at level 1
7006 becomes {std::vector} and the inner level 2 is {int}. */
7010 {
7012 /* We want arguments for the partial specialization, not arguments for
7013 the primary template. */
7015 else
7017 }
7019 {
7020 /* This is an argument of the current template, so we haven't set
7021 DECL_CONTEXT yet. */
7022 tree relevant_template_parms;
7024 /* Parameter levels that are greater than the level of the given
7025 template template parm are irrelevant. */
7032 }
7039 complain,
7042 }
7044 /* A cache of template template parameters with match-all default
7045 arguments. */
7047 static void
7049 {
7053 }
7054 static tree
7056 {
7061 }
7063 /* T is a bound template template-parameter. Copy its arguments into default
7064 arguments of the template template-parameter's template parameters. */
7066 static tree
7068 {
7091 {
7094 {
7097 }
7098 }
7102 }
7104 /* ARG is a bound potential template template-argument, and PARGS is a list
7105 of arguments for the corresponding template template-parameter. Adjust
7106 PARGS as appropriate for application to ARG's template, and if ARG is a
7107 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7108 arguments to the template template parameter. */
7110 static tree
7112 {
7116 {
7117 /* When comparing two template template-parameters in partial ordering,
7118 rewrite the one currently being used as an argument to have default
7119 arguments for all parameters. */
7125 }
7126 else
7127 {
7128 tree aparms
7133 }
7136 }
7138 /* Subroutine of unify for the case when PARM is a
7139 BOUND_TEMPLATE_TEMPLATE_PARM. */
7141 static int
7144 {
7148 /* The template template parm might be variadic and the argument
7149 not, so flatten both argument lists. */
7155 {
7156 /* In keeping with P0522R0, adjust P's template arguments
7157 to apply to A's template; then flatten it again. */
7160 }
7166 /* If the P0522 adjustment eliminated a pack expansion, deduce
7167 empty packs. */
7175 }
7177 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7178 template template parameters. Both PARM_PARMS and ARG_PARMS are
7179 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7180 or PARM_DECL.
7182 Consider the example:
7183 template <class T> class A;
7184 template<template <class U> class TT> class B;
7186 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7187 the parameters to A, and OUTER_ARGS contains A. */
7189 static int
7191 tree arg_parms,
7192 tsubst_flags_t complain,
7193 tree in_decl,
7194 tree outer_args)
7195 {
7207 {
7208 /* P0522R0: A template template-parameter P is at least as specialized as
7209 a template template-argument A if, given the following rewrite to two
7210 function templates, the function template corresponding to P is at
7211 least as specialized as the function template corresponding to A
7212 according to the partial ordering rules for function templates
7213 ([temp.func.order]). Given an invented class template X with the
7214 template parameter list of A (including default arguments):
7216 * Each of the two function templates has the same template parameters,
7217 respectively, as P or A.
7219 * Each function template has a single function parameter whose type is
7220 a specialization of X with template arguments corresponding to the
7221 template parameters from the respective function template where, for
7222 each template parameter PP in the template parameter list of the
7223 function template, a corresponding template argument AA is formed. If
7224 PP declares a parameter pack, then AA is the pack expansion
7225 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7227 If the rewrite produces an invalid type, then P is not at least as
7228 specialized as A. */
7230 /* So coerce P's args to apply to A's parms, and then deduce between A's
7231 args and the converted args. If that succeeds, A is at least as
7232 specialized as P, so they match.*/
7239 {
7245 }
7246 }
7248 /* Determine whether we have a parameter pack at the end of the
7249 template template parameter's template parameter list. */
7251 {
7258 {
7272 }
7273 }
7279 /* Check all of the template parameters except the parameter pack at
7280 the end (if any). */
7282 {
7291 outer_args))
7294 }
7297 {
7298 /* Check each of the template parameters in the template
7299 argument against the template parameter pack at the end of
7300 the template template parameter. */
7307 {
7314 outer_args))
7316 }
7317 }
7320 }
7322 /* Verifies that the deduced template arguments (in TARGS) for the
7323 template template parameters (in TPARMS) represent valid bindings,
7324 by comparing the template parameter list of each template argument
7325 to the template parameter list of its corresponding template
7326 template parameter, in accordance with DR150. This
7327 routine can only be called after all template arguments have been
7328 deduced. It will return TRUE if all of the template template
7329 parameter bindings are okay, FALSE otherwise. */
7330 bool
7332 {
7336 /* We're dealing with template parms in this process. */
7342 {
7347 {
7352 {
7353 /* Look inside the argument pack. */
7356 }
7359 {
7363 /* Extract the next argument from the argument
7364 pack. */
7368 /* Look at the pattern of the pack expansion. */
7371 /* Extract the template parameters from the template
7372 argument. */
7378 /* Verify that we can coerce the template template
7379 parameters from the template argument to the template
7380 parameter. This requires an exact match. */
7382 && !coerce_template_template_parms
7384 targ_parms,
7385 tf_none,
7386 tparm,
7387 targs))
7388 {
7391 }
7392 }
7393 }
7394 }
7396 out:
7400 }
7402 /* Since type attributes aren't mangled, we need to strip them from
7403 template type arguments. */
7405 static tree
7407 {
7417 }
7419 /* And from inside dependent non-type arguments like sizeof(Type). */
7421 static tree
7423 {
7433 }
7435 // A template declaration can be substituted for a constrained
7436 // template template parameter only when the argument is more
7437 // constrained than the parameter.
7438 static bool
7440 {
7443 /* For now, allow constrained template template arguments
7444 and unconstrained template template parameters. */
7450 // If the template parameter is constrained, we need to rewrite its
7451 // constraints in terms of the ARG's template parameters. This ensures
7452 // that all of the template parameter types will have the same depth.
7453 //
7454 // Note that this is only valid when coerce_template_template_parm is
7455 // true for the innermost template parameters of PARM and ARG. In other
7456 // words, because coercion is successful, this conversion will be valid.
7458 {
7465 }
7468 }
7470 // Convert a placeholder argument into a binding to the original
7471 // parameter. The original parameter is saved as the TREE_TYPE of
7472 // ARG.
7475 {
7478 }
7480 /* Convert the indicated template ARG as necessary to match the
7481 indicated template PARM. Returns the converted ARG, or
7482 error_mark_node if the conversion was unsuccessful. Error and
7483 warning messages are issued under control of COMPLAIN. This
7484 conversion is for the Ith parameter in the parameter list. ARGS is
7485 the full set of template arguments deduced so far. */
7487 static tree
7489 tree arg,
7490 tree args,
7491 tsubst_flags_t complain,
7493 tree in_decl)
7494 {
7495 tree orig_arg;
7496 tree val;
7502 /* Trivially convert placeholders. */
7511 {
7512 /* The template argument was the name of some
7513 member function. That's usually
7514 invalid, but static members are OK. In any
7515 case, grab the underlying fields/functions
7516 and issue an error later if required. */
7519 }
7527 /* When determining whether an argument pack expansion is a template,
7528 look at the pattern. */
7532 /* Deal with an injected-class-name used as a template template arg. */
7534 {
7537 {
7547 }
7548 }
7550 is_tmpl_type =
7566 {
7568 {
7572 }
7575 "to refer to a type member of a template parameter, "
7580 typename_type,
7581 complain);
7584 }
7586 {
7588 {
7590 {
7602 else
7605 }
7606 }
7608 }
7610 {
7612 {
7619 else
7622 }
7624 }
7627 /* We already did the appropriate conversion when packing args. */
7630 {
7632 {
7634 /* The number of argument required is not known yet.
7635 Just accept it for now. */
7637 else
7638 {
7640 tree argparm;
7642 /* Strip alias templates that are equivalent to another
7643 template. */
7649 args))
7650 {
7653 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7654 TEMPLATE_DECL. */
7656 {
7661 }
7662 }
7663 else
7664 {
7666 {
7673 }
7676 }
7678 // Check that the constraints are compatible before allowing the
7679 // substitution.
7682 {
7684 {
7690 }
7692 }
7693 }
7694 }
7695 else
7697 /* We only form one instance of each template specialization.
7698 Therefore, if we use a non-canonical variant (i.e., a
7699 typedef), any future messages referring to the type will use
7700 the typedef, which is confusing if those future uses do not
7701 themselves also use the typedef. */
7704 }
7705 else
7706 {
7710 {
7714 }
7715 else
7723 /* We used to call digest_init here. However, digest_init
7724 will report errors, which we don't want when complain
7725 is zero. More importantly, digest_init will try too
7726 hard to convert things: for example, `0' should not be
7727 converted to pointer type at this point according to
7728 the standard. Accepting this is not merely an
7729 extension, since deciding whether or not these
7730 conversions can occur is part of determining which
7731 function template to call, or whether a given explicit
7732 argument specification is valid. */
7734 else
7744 {
7745 /* Reject template arguments that are references to built-in
7746 functions with no library fallbacks. */
7755 }
7758 {
7759 /* Strip typedefs from the SCOPE_REF. */
7762 complain);
7765 }
7766 }
7769 }
7771 /* Coerces the remaining template arguments in INNER_ARGS (from
7772 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7773 Returns the coerced argument pack. PARM_IDX is the position of this
7774 parameter in the template parameter list. ARGS is the original
7775 template argument list. */
7776 static tree
7779 tree args,
7780 tree inner_args,
7782 tree new_args,
7784 tree in_decl,
7785 tsubst_flags_t complain)
7786 {
7789 tree packed_args;
7790 tree argument_pack;
7797 {
7798 /* When the template parameter is a non-type template parameter pack
7799 or template template parameter pack whose type or template
7800 parameters use parameter packs, we know exactly how many arguments
7801 we are looking for. Build a vector of the instantiated decls for
7802 these template parameters in PACKED_PARMS. */
7803 /* We can't use make_pack_expansion here because it would interpret a
7804 _DECL as a use rather than a declaration. */
7818 /* If we're doing a partial instantiation of a member template,
7819 verify that all of the types used for the non-type
7820 template parameter pack are, in fact, valid for non-type
7821 template parameters. */
7824 {
7827 {
7831 }
7832 /* We don't know how many args we have yet, just
7833 use the unconverted ones for now. */
7835 }
7838 }
7839 /* Check if we have a placeholder pack, which indicates we're
7840 in the context of a introduction list. In that case we want
7841 to match this pack to the single placeholder. */
7845 {
7848 }
7849 else
7852 /* Convert the remaining arguments, which will be a part of the
7853 parameter pack "parm". */
7856 {
7862 {
7863 /* Once we've packed as many args as we have types, stop. */
7867 /* We don't know how many args we have yet, just
7868 use the unconverted ones for now. */
7870 else
7872 }
7875 {
7878 }
7879 else
7882 in_decl);
7886 }
7890 {
7895 }
7900 else
7901 {
7904 }
7911 }
7913 /* Returns the number of pack expansions in the template argument vector
7914 ARGS. */
7916 static int
7918 {
7923 {
7927 }
7929 }
7931 /* Convert all template arguments to their appropriate types, and
7932 return a vector containing the innermost resulting template
7933 arguments. If any error occurs, return error_mark_node. Error and
7934 warning messages are issued under control of COMPLAIN.
7936 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7937 for arguments not specified in ARGS. Otherwise, if
7938 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7939 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7940 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7941 ARGS. */
7943 static tree
7945 tree args,
7946 tree in_decl,
7947 tsubst_flags_t complain,
7950 {
7952 tree orig_inner_args;
7953 tree inner_args;
7954 tree new_args;
7955 tree new_inner_args;
7959 /* When used as a boolean value, indicates whether this is a
7960 variadic template parameter list. Since it's an int, we can also
7961 subtract it from nparms to get the number of non-variadic
7962 parameters. */
7967 /* Likewise for parameters with default arguments. */
7975 /* Determine if there are any parameter packs or default arguments. */
7977 {
7985 }
7988 /* If there are no parameters that follow a parameter pack, we need to
7989 expand any argument packs so that we can deduce a parameter pack from
7990 some non-packed args followed by an argument pack, as in variadic85.C.
7991 If there are such parameters, we need to leave argument packs intact
7992 so the arguments are assigned properly. This can happen when dealing
7993 with a nested class inside a partial specialization of a class
7994 template, as in variadic92.C, or when deducing a template parameter pack
7995 from a sub-declarator, as in variadic114.C. */
7999 /* Count any pack expansion args. */
8005 && require_all_args
8006 && !variadic_args_p
8007 && (!use_default_args
8010 {
8012 {
8014 {
8018 }
8019 else
8026 }
8029 }
8030 /* We can't pass a pack expansion to a non-pack parameter of an alias
8031 template (DR 1430). */
8035 && variadic_args_p
8037 {
8039 {
8041 {
8047 {
8050 "pack expansion argument for non-pack parameter "
8052 else
8054 "pack expansion argument for non-pack parameter "
8058 }
8059 }
8061 found:;
8062 }
8064 }
8066 /* We need to evaluate the template arguments, even though this
8067 template-id may be nested within a "sizeof". */
8076 {
8077 tree arg;
8078 tree parm;
8080 /* Get the Ith template parameter. */
8084 {
8087 }
8089 /* Calculate the next argument. */
8092 else
8097 {
8098 /* Some arguments will be placed in the
8099 template parameter pack PARM. */
8106 {
8107 /* We don't know how many args we have yet, just use the
8108 unconverted (and still packed) ones for now. */
8112 }
8116 /* Store this argument. */
8118 {
8119 lost++;
8120 /* We are done with all of the arguments. */
8122 }
8123 else
8124 {
8127 }
8130 }
8132 {
8134 {
8135 /* "If every valid specialization of a variadic template
8136 requires an empty template parameter pack, the template is
8137 ill-formed, no diagnostic required." So check that the
8138 pattern works with this parameter. */
8143 in_decl);
8145 {
8150 }
8152 /* Recover from missing typename. */
8156 /* We don't know how many args we have yet, just
8157 use the unconverted ones for now. */
8161 }
8162 }
8164 {
8165 /* There must be a default arg in this case. */
8168 /* The position of the first default template argument,
8169 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8170 Record that. */
8174 }
8175 else
8179 {
8182 }
8184 /* This only occurs if there was an error in the template
8185 parameter list itself (which we would already have
8186 reported) that we are trying to recover from, e.g., a class
8187 template with a parameter list such as
8188 template<typename..., typename>. */
8190 else
8196 lost++;
8198 }
8203 {
8205 {
8210 }
8212 }
8222 }
8224 /* Convert all template arguments to their appropriate types, and
8225 return a vector containing the innermost resulting template
8226 arguments. If any error occurs, return error_mark_node. Error and
8227 warning messages are not issued.
8229 Note that no function argument deduction is performed, and default
8230 arguments are used to fill in unspecified arguments. */
8231 tree
8233 {
8235 }
8237 /* Convert all template arguments to their appropriate type, and
8238 instantiate default arguments as needed. This returns a vector
8239 containing the innermost resulting template arguments, or
8240 error_mark_node if unsuccessful. */
8241 tree
8243 tsubst_flags_t complain)
8244 {
8246 }
8248 /* Like coerce_template_parms. If PARMS represents all template
8249 parameters levels, this function returns a vector of vectors
8250 representing all the resulting argument levels. Note that in this
8251 case, only the innermost arguments are coerced because the
8252 outermost ones are supposed to have been coerced already.
8254 Otherwise, if PARMS represents only (the innermost) vector of
8255 parameters, this function returns a vector containing just the
8256 innermost resulting arguments. */
8258 static tree
8260 tree args,
8261 tree in_decl,
8262 tsubst_flags_t complain,
8265 {
8268 tree coerced_args;
8271 {
8273 tree level;
8279 {
8280 tree l;
8284 require_all_args,
8285 use_default_args);
8286 else
8293 }
8294 }
8295 else
8298 require_all_args,
8299 use_default_args);
8301 }
8303 /* Returns 1 if template args OT and NT are equivalent. */
8305 int
8307 {
8316 /* For member templates */
8325 {
8342 }
8346 {
8349 /* Don't treat an alias template specialization with dependent
8350 arguments as equivalent to its underlying type when used as a
8351 template argument; we need them to be distinct so that we
8352 substitute into the specialization arguments at instantiation
8353 time. And aliases can't be equivalent without being ==, so
8354 we don't need to look any deeper.
8356 During partial ordering, however, we need to treat them normally so
8357 that we can order uses of the same alias with different
8358 cv-qualification (79960). */
8362 else
8364 }
8367 else
8368 {
8369 /* Try to treat a template non-type argument that has been converted
8370 to the parameter type as equivalent to one that hasn't yet. */
8383 }
8384 }
8386 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8387 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8388 NEWARG_PTR with the offending arguments if they are non-NULL. */
8390 int
8394 {
8407 {
8412 {
8418 }
8419 }
8421 }
8425 {
8427 }
8429 static void
8431 {
8441 /* We are called both from instantiate_decl, where we've already had a
8442 tinst_level pushed, and instantiate_template, where we haven't.
8443 Compensate. */
8454 else
8463 }
8466 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8467 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8468 documentation for TEMPLATE_ID_EXPR. */
8470 tree
8472 {
8473 tree type;
8481 {
8484 }
8487 {
8489 unknown_type_node,
8491 arglist);
8493 }
8500 }
8502 /* Within the scope of a template class S<T>, the name S gets bound
8503 (in build_self_reference) to a TYPE_DECL for the class, not a
8504 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8505 or one of its enclosing classes, and that type is a template,
8506 return the associated TEMPLATE_DECL. Otherwise, the original
8507 DECL is returned.
8509 Also handle the case when DECL is a TREE_LIST of ambiguous
8510 injected-class-names from different bases. */
8512 tree
8514 {
8518 /* DR 176: A lookup that finds an injected-class-name (10.2
8519 [class.member.lookup]) can result in an ambiguity in certain cases
8520 (for example, if it is found in more than one base class). If all of
8521 the injected-class-names that are found refer to specializations of
8522 the same class template, and if the name is followed by a
8523 template-argument-list, the reference refers to the class template
8524 itself and not a specialization thereof, and is not ambiguous. */
8526 {
8529 {
8535 }
8538 else
8540 }
8546 }
8548 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8549 parameters, find the desired type.
8551 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8553 IN_DECL, if non-NULL, is the template declaration we are trying to
8554 instantiate.
8556 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8557 the class we are looking up.
8559 Issue error and warning messages under control of COMPLAIN.
8561 If the template class is really a local class in a template
8562 function, then the FUNCTION_CONTEXT is the function in which it is
8563 being instantiated.
8565 ??? Note that this function is currently called *twice* for each
8566 template-id: the first time from the parser, while creating the
8567 incomplete type (finish_template_type), and the second type during the
8568 real instantiation (instantiate_template_class). This is surely something
8569 that we want to avoid. It also causes some problems with argument
8570 coercion (see convert_nontype_argument for more information on this). */
8572 static tree
8575 {
8577 tree t;
8580 spec_entry elt;
8581 hashval_t hash;
8584 {
8588 else
8589 {
8596 }
8599 }
8601 {
8604 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8605 an implicit typename for the second A. Deal with it. */
8610 {
8613 }
8614 }
8617 {
8620 }
8622 {
8626 }
8628 {
8631 }
8633 /* Issue an error message if we didn't find a template. */
8635 {
8639 }
8642 /* Make sure it's a user visible template, if it was named by
8643 the user. */
8646 {
8648 {
8652 }
8654 }
8658 /* An alias that just changes the name of a template is equivalent to the
8659 other template, so if any of the arguments are pack expansions, strip
8660 the alias to avoid problems with a pack expansion passed to a non-pack
8661 alias template parameter (DR 1430). */
8666 {
8667 tree parm;
8676 }
8677 else
8678 {
8680 tree gen_tmpl;
8681 tree type_decl;
8689 /* An error occurred while building the template TEMPL, and a
8690 diagnostic has most certainly been emitted for that
8691 already. Let's propagate that error. */
8700 {
8701 /* We've been given an incomplete set of template arguments.
8702 For example, given:
8704 template <class T> struct S1 {
8705 template <class U> struct S2 {};
8706 template <class U> struct S2<U*> {};
8707 };
8709 we will be called with an ARGLIST of `U*', but the
8710 TEMPLATE will be `template <class T> template
8711 <class U> struct S1<T>::S2'. We must fill in the missing
8712 arguments. */
8716 }
8718 /* Now we should have enough arguments. */
8721 /* From here on, we're only interested in the most general
8722 template. */
8724 /* Calculate the BOUND_ARGS. These will be the args that are
8725 actually tsubst'd into the definition to create the
8726 instantiation. */
8728 complain,
8733 /* We were unable to bind the arguments. */
8736 /* In the scope of a template class, explicit references to the
8737 template class refer to the type of the template, not any
8738 instantiation of it. For example, in:
8740 template <class T> class C { void f(C<T>); }
8742 the `C<T>' is just the same as `C'. Outside of the
8743 class, however, such a reference is an instantiation. */
8747 {
8752 }
8754 /* If we already have this specialization, return it. */
8764 /* If the the template's constraints are not satisfied,
8765 then we cannot form a valid type.
8767 Note that the check is deferred until after the hash
8768 lookup. This prevents redundant checks on previously
8769 instantiated specializations. */
8771 {
8773 {
8776 }
8778 }
8782 /* If the deduced arguments are invalid, then the binding
8783 failed. */
8787 complain))
8794 {
8799 }
8809 /* Create the type. */
8811 {
8812 /* The user referred to a specialization of an alias
8813 template represented by GEN_TMPL.
8815 [temp.alias]/2 says:
8817 When a template-id refers to the specialization of an
8818 alias template, it is equivalent to the associated
8819 type obtained by substitution of its
8820 template-arguments for the template-parameters in the
8821 type-id of the alias template. */
8824 /* Note that the call above (by indirectly calling
8825 register_specialization in tsubst_decl) registers the
8826 TYPE_DECL representing the specialization of the alias
8827 template. So next time someone substitutes ARGLIST for
8828 the template parms into the alias template (GEN_TMPL),
8829 she'll get that TYPE_DECL back. */
8833 }
8835 {
8837 {
8848 }
8849 else
8850 {
8851 /* We don't want to call start_enum for this type, since
8852 the values for the enumeration constants may involve
8853 template parameters. And, no one should be interested
8854 in the enumeration constants for such a type. */
8857 }
8861 }
8863 {
8869 /* A local class. Make sure the decl gets registered properly. */
8874 /* This instantiation is another name for the primary
8875 template type. Set the TYPE_CANONICAL field
8876 appropriately. */
8879 /* Some of the template arguments require structural
8880 equality testing, so this template class requires
8881 structural equality testing. */
8883 }
8884 else
8887 /* If we called start_enum or pushtag above, this information
8888 will already be set up. */
8890 {
8897 }
8898 else
8902 {
8908 {
8911 }
8912 }
8916 {
8920 {
8921 tree attributes
8929 }
8930 }
8932 /* Let's consider the explicit specialization of a member
8933 of a class template specialization that is implicitly instantiated,
8934 e.g.:
8935 template<class T>
8936 struct S
8937 {
8938 template<class U> struct M {}; //#0
8939 };
8941 template<>
8942 template<>
8943 struct S<int>::M<char> //#1
8944 {
8945 int i;
8946 };
8947 [temp.expl.spec]/4 says this is valid.
8949 In this case, when we write:
8950 S<int>::M<char> m;
8952 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8953 the one of #0.
8955 When we encounter #1, we want to store the partial instantiation
8956 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8958 For all cases other than this "explicit specialization of member of a
8959 class template", we just want to store the most general template into
8960 the CLASSTYPE_TI_TEMPLATE of M.
8962 This case of "explicit specialization of member of a class template"
8963 only happens when:
8964 1/ the enclosing class is an instantiation of, and therefore not
8965 the same as, the context of the most general template, and
8966 2/ we aren't looking at the partial instantiation itself, i.e.
8967 the innermost arguments are not the same as the innermost parms of
8968 the most general template.
8970 So it's only when 1/ and 2/ happens that we want to use the partial
8971 instantiation of the member template in lieu of its most general
8972 template. */
8976 /* the enclosing class must be an instantiation... */
8979 {
8983 tree partial_inst_args =
8990 use_partial_inst_tmpl =
8991 /*...and we must not be looking at the partial instantiation
8992 itself. */
8994 partial_inst_args);
8995 }
8998 /* This case is easy; there are no member templates involved. */
9000 else
9001 {
9002 /* This is a full instantiation of a member template. Find
9003 the partial instantiation of which this is an instance. */
9005 /* Temporarily reduce by one the number of levels in the ARGLIST
9006 so as to avoid comparing the last set of arguments. */
9010 /* FOUND is either a proper class type, or an alias
9011 template specialization. In the later case, it's a
9012 TYPE_DECL, resulting from the substituting of arguments
9013 for parameters in the TYPE_DECL of the alias template
9014 done earlier. So be careful while getting the template
9015 of FOUND. */
9017 ? found
9021 }
9023 // Build template info for the new specialization.
9032 /* Note this use of the partial instantiation so we can check it
9033 later in maybe_process_partial_specialization. */
9040 /* Now that the type has been registered on the instantiations
9041 list, we set up the enumerators. Because the enumeration
9042 constants may involve the enumeration type itself, we make
9043 sure to register the type first, and then create the
9044 constants. That way, doing tsubst_expr for the enumeration
9045 constants won't result in recursive calls here; we'll find
9046 the instantiation and exit above. */
9050 /* If the type makes use of template parameters, the
9051 code that generates debugging information will crash. */
9054 /* Possibly limit visibility based on template args. */
9061 }
9062 }
9064 /* Wrapper for lookup_template_class_1. */
9066 tree
9069 {
9070 tree ret;
9076 }
9078 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9080 tree
9082 {
9083 /* The type of the expression is NULL_TREE since the template-id could refer
9084 to an explicit or partial specialization. */
9087 /* Except that concepts are always bool. */
9090 }
9092 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9094 tree
9096 {
9100 /* We never want to return a VAR_DECL for a variable concept, since they
9101 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9116 {
9118 {
9121 }
9123 }
9125 /* If a template-id refers to a specialization of a variable
9126 concept, then the expression is true if and only if the
9127 concept's constraints are satisfied by the given template
9128 arguments.
9130 NOTE: This is an extension of Concepts Lite TS that
9131 allows constraints to be used in expressions. */
9133 {
9136 }
9139 }
9141 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9142 TARGS template args, and instantiate it if it's not dependent. */
9144 tree
9146 tsubst_flags_t complain)
9147 {
9150 {
9153 }
9156 }
9158 \f
9159 struct pair_fn_data
9160 {
9161 tree_fn_t fn;
9162 tree_fn_t any_fn;
9164 /* True when we should also visit template parameters that occur in
9165 non-deduced contexts. */
9168 };
9170 /* Called from for_each_template_parm via walk_tree. */
9172 static tree
9174 {
9181 #define WALK_SUBTREE(NODE) \
9182 do \
9183 { \
9184 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9185 pfd->include_nondeduced_p, \
9186 pfd->any_fn); \
9187 if (result) goto out; \
9188 } \
9189 while (0)
9199 {
9203 /* Fall through. */
9209 else
9219 /* Since we're not going to walk subtrees, we have to do this
9220 explicitly here. */
9222 /* Fall through. */
9225 /* Check the return type. */
9228 /* Check the parameter types. Since default arguments are not
9229 instantiated until they are needed, the TYPE_ARG_TYPES may
9230 contain expressions that involve template parameters. But,
9231 no-one should be looking at them yet. And, once they're
9232 instantiated, they don't contain template parameters, so
9233 there's no point in looking at them then, either. */
9234 {
9235 tree parm;
9240 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9241 want walk_tree walking into them itself. */
9243 }
9246 {
9250 }
9267 /* Fall through. */
9279 /* Record template parameters such as `T' inside `TT<T>'. */
9281 /* Fall through. */
9293 /* A template template parameter is encountered. */
9297 /* Already substituted template template parameter */
9302 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9303 partial instantiation. */
9315 /* If there's no type, then this thing must be some expression
9316 involving template parameters. */
9338 }
9340 #undef WALK_SUBTREE
9342 /* We didn't find any template parameters we liked. */
9343 out:
9345 }
9347 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9348 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9349 call FN with the parameter and the DATA.
9350 If FN returns nonzero, the iteration is terminated, and
9351 for_each_template_parm returns 1. Otherwise, the iteration
9352 continues. If FN never returns a nonzero value, the value
9353 returned by for_each_template_parm is 0. If FN is NULL, it is
9354 considered to be the function which always returns 1.
9356 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9357 parameters that occur in non-deduced contexts. When false, only
9358 visits those template parameters that can be deduced. */
9360 static tree
9364 tree_fn_t any_fn)
9365 {
9367 tree result;
9369 /* Set up. */
9375 /* Walk the tree. (Conceptually, we would like to walk without
9376 duplicates, but for_each_template_parm_r recursively calls
9377 for_each_template_parm, so we would need to reorganize a fair
9378 bit to use walk_tree_without_duplicates, so we keep our own
9379 visited list.) */
9382 else
9385 for_each_template_parm_r,
9389 /* Clean up. */
9391 {
9394 }
9397 }
9399 /* Returns true if T depends on any template parameter. */
9401 int
9403 {
9433 else
9434 {
9437 }
9442 }
9444 /* Returns true iff current_function_decl is an incompletely instantiated
9445 template. Useful instead of processing_template_decl because the latter
9446 is set to 0 during instantiate_non_dependent_expr. */
9448 bool
9450 {
9459 }
9461 /* Returns true if T depends on any template parameter with level LEVEL. */
9463 bool
9465 {
9468 }
9470 /* Returns true if the signature of DECL depends on any template parameter from
9471 its enclosing class. */
9473 bool
9475 {
9485 template_parm_outer_level,
9495 }
9497 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9498 ill-formed translation unit, i.e. a variable or function that isn't
9499 usable in a constant expression. */
9503 {
9507 }
9509 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9510 neglectable and instantiated from within an erroneous instantiation. */
9512 static bool
9514 {
9525 }
9533 /* We're starting to instantiate D; record the template instantiation context
9534 for diagnostics and to restore it later. */
9536 bool
9538 {
9540 }
9542 /* We're starting to instantiate D; record the template instantiation context
9543 at LOC for diagnostics and to restore it later. */
9545 bool
9547 {
9551 {
9552 /* Tell error.c not to try to instantiate any templates. */
9555 "template instantiation depth exceeds maximum of %d"
9557 max_tinst_depth);
9559 }
9561 /* If the current instantiation caused problems, don't let it instantiate
9562 anything else. Do allow deduction substitution and decls usable in
9563 constant expressions. */
9567 /* When not -quiet, dump template instantiations other than functions, since
9568 announce_function will take care of those. */
9587 }
9589 /* We're done instantiating this template; return to the instantiation
9590 context. */
9592 void
9594 {
9595 /* Restore the filename and line number stashed away when we started
9596 this instantiation. */
9600 }
9602 /* We're instantiating a deferred template; restore the template
9603 instantiation context in which the instantiation was requested, which
9604 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9606 static tree
9608 {
9620 }
9622 /* Returns the TINST_LEVEL which gives the original instantiation
9623 context. */
9627 {
9633 }
9635 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9636 vector of template arguments, as for tsubst.
9638 Returns an appropriate tsubst'd friend declaration. */
9640 static tree
9642 {
9643 tree new_friend;
9648 /* This was a friend declared with an explicit template
9649 argument list, e.g.:
9651 friend void f<>(T);
9653 to indicate that f was a template instantiation, not a new
9654 function declaration. Now, we have to figure out what
9655 instantiation of what template. */
9656 {
9658 tree new_args;
9659 tree tmpl;
9662 /* Friend functions are looked up in the containing namespace scope.
9663 We must enter that scope, to avoid finding member functions of the
9664 current class with same name. */
9679 tsk_none);
9681 }
9685 /* The NEW_FRIEND will look like an instantiation, to the
9686 compiler, but is not an instantiation from the point of view of
9687 the language. For example, we might have had:
9689 template <class T> struct S {
9690 template <class U> friend void f(T, U);
9691 };
9693 Then, in S<int>, template <class U> void f(int, U) is not an
9694 instantiation of anything. */
9700 {
9704 }
9706 /* The mangled name for the NEW_FRIEND is incorrect. The function
9707 is not a template instantiation and should not be mangled like
9708 one. Therefore, we forget the mangling here; we'll recompute it
9709 later if we need it. */
9711 {
9714 }
9717 {
9718 tree old_decl;
9719 tree new_friend_template_info;
9720 tree new_friend_result_template_info;
9721 tree ns;
9724 /* We must save some information from NEW_FRIEND before calling
9725 duplicate decls since that function will free NEW_FRIEND if
9726 possible. */
9728 new_friend_is_defn =
9733 {
9734 /* This declaration is a `primary' template. */
9737 new_friend_result_template_info
9739 }
9740 else
9743 /* Inside pushdecl_namespace_level, we will push into the
9744 current namespace. However, the friend function should go
9745 into the namespace of the template. */
9755 {
9756 /* This new friend declaration matched an existing
9757 declaration. For example, given:
9759 template <class T> void f(T);
9760 template <class U> class C {
9761 template <class T> friend void f(T) {}
9762 };
9764 the friend declaration actually provides the definition
9765 of `f', once C has been instantiated for some type. So,
9766 old_decl will be the out-of-class template declaration,
9767 while new_friend is the in-class definition.
9769 But, if `f' was called before this point, the
9770 instantiation of `f' will have DECL_TI_ARGS corresponding
9771 to `T' but not to `U', references to which might appear
9772 in the definition of `f'. Previously, the most general
9773 template for an instantiation of `f' was the out-of-class
9774 version; now it is the in-class version. Therefore, we
9775 run through all specialization of `f', adding to their
9776 DECL_TI_ARGS appropriately. In particular, they need a
9777 new set of outer arguments, corresponding to the
9778 arguments for this class instantiation.
9780 The same situation can arise with something like this:
9782 friend void f(int);
9783 template <class T> class C {
9784 friend void f(T) {}
9785 };
9787 when `C<int>' is instantiated. Now, `f(int)' is defined
9788 in the class. */
9791 /* On the other hand, if the in-class declaration does
9792 *not* provide a definition, then we don't want to alter
9793 existing definitions. We can just leave everything
9794 alone. */
9795 ;
9796 else
9797 {
9801 /* Overwrite whatever template info was there before, if
9802 any, with the new template information pertaining to
9803 the declaration. */
9807 {
9808 /* We should have called reregister_specialization in
9809 duplicate_decls. */
9814 /* Instantiate it if the global has already been used. */
9818 }
9819 else
9820 {
9821 tree t;
9823 /* Indicate that the old function template is a partial
9824 instantiation. */
9832 /* Reassign any specializations already in the hash table
9833 to the new more general template, and add the
9834 additional template args. */
9838 {
9840 spec_entry elt;
9852 register_specialization
9855 }
9857 }
9858 }
9860 /* The information from NEW_FRIEND has been merged into OLD_DECL
9861 by duplicate_decls. */
9863 }
9864 }
9865 else
9866 {
9870 /* In the code
9871 template <class T> class C {
9872 template <class U> friend void C1<U>::f (); // case 1
9873 friend void C2<T>::f (); // case 2
9874 };
9875 we only need to make sure CONTEXT is a complete type for
9876 case 2. To distinguish between the two cases, we note that
9877 CONTEXT of case 1 remains dependent type after tsubst while
9878 this isn't true for case 2. */
9888 {
9890 /* do_friend adds the TEMPLATE_DECL for any member friend
9891 template even if it isn't a member template, i.e.
9892 template <class T> friend A<T>::f();
9893 Look through it in that case. */
9897 /* Check to see that the declaration is really present, and,
9898 possibly obtain an improved declaration. */
9903 }
9904 }
9907 }
9909 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9910 template arguments, as for tsubst.
9912 Returns an appropriate tsubst'd friend type or error_mark_node on
9913 failure. */
9915 static tree
9917 {
9918 tree friend_type;
9919 tree tmpl;
9920 tree context;
9923 {
9926 }
9931 {
9934 else
9936 }
9938 /* Look for a class template declaration. We look for hidden names
9939 because two friend declarations of the same template are the
9940 same. For example, in:
9942 struct A {
9943 template <typename> friend class F;
9944 };
9945 template <typename> struct B {
9946 template <typename> friend class F;
9947 };
9949 both F templates are the same. */
9953 /* But, if we don't find one, it might be because we're in a
9954 situation like this:
9956 template <class T>
9957 struct S {
9958 template <class U>
9959 friend struct S;
9960 };
9962 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9963 for `S<int>', not the TEMPLATE_DECL. */
9965 {
9968 }
9971 {
9972 /* The friend template has already been declared. Just
9973 check to see that the declarations match, and install any new
9974 default parameters. We must tsubst the default parameters,
9975 of course. We only need the innermost template parameters
9976 because that is all that redeclare_class_template will look
9977 at. */
9980 {
9981 tree parms;
9982 location_t saved_input_location;
9992 }
9995 }
9996 else
9997 {
9998 /* The friend template has not already been declared. In this
9999 case, the instantiation of the template class will cause the
10000 injection of this template into the global scope. */
10005 /* The new TMPL is not an instantiation of anything, so we
10006 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10007 the new type because that is supposed to be the corresponding
10008 template decl, i.e., TMPL. */
10015 /* Inject this template into the global scope. */
10017 }
10020 {
10023 else
10025 }
10028 }
10030 /* Returns zero if TYPE cannot be completed later due to circularity.
10031 Otherwise returns one. */
10033 static int
10035 {
10045 else
10047 }
10052 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10053 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10055 static tree
10058 {
10067 {
10074 clauses
10078 else
10080 }
10081 /* If the first attribute argument is an identifier, don't
10082 pass it through tsubst. Attributes like mode, format,
10083 cleanup and several target specific attributes expect it
10084 unmodified. */
10086 {
10087 tree chain
10092 }
10094 {
10095 /* An attribute pack expansion. */
10104 {
10108 }
10110 }
10111 else
10118 }
10120 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10121 unchanged or a new TREE_LIST chain. */
10123 static tree
10126 {
10131 {
10135 }
10139 {
10142 {
10145 {
10147 do
10152 }
10153 }
10155 }
10158 }
10160 /* Apply any attributes which had to be deferred until instantiation
10161 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10162 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10164 static void
10167 {
10169 tree t;
10176 {
10180 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10181 to our attributes parameter. */
10183 }
10184 else
10185 {
10187 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10188 lookup_template_class_1, and should be preserved. */
10192 }
10196 {
10200 }
10204 {
10209 {
10212 {
10216 do
10219 }
10220 else
10222 }
10225 }
10226 }
10228 /* Perform (or defer) access check for typedefs that were referenced
10229 from within the template TMPL code.
10230 This is a subroutine of instantiate_decl and instantiate_class_template.
10231 TMPL is the template to consider and TARGS is the list of arguments of
10232 that template. */
10234 static void
10236 {
10237 location_t saved_location;
10248 {
10260 /* Make access check error messages point to the location
10261 of the use of the typedef. */
10265 tf_warning_or_error);
10266 }
10268 }
10270 static tree
10272 {
10274 tree typedecl;
10275 tree pbinfo;
10276 tree base_list;
10278 tree fn_context;
10287 /* Figure out which template is being instantiated. */
10291 /* Determine what specialization of the original template to
10292 instantiate. */
10295 {
10298 }
10300 {
10301 /* This TYPE is actually an instantiation of a partial
10302 specialization. We replace the innermost set of ARGS with
10303 the arguments appropriate for substitution. For example,
10304 given:
10306 template <class T> struct S {};
10307 template <class T> struct S<T*> {};
10309 and supposing that we are instantiating S<int*>, ARGS will
10310 presently be {int*} -- but we need {int}. */
10313 }
10314 else
10315 {
10318 }
10320 /* If the template we're instantiating is incomplete, then clearly
10321 there's nothing we can do. */
10325 /* If we've recursively instantiated too many templates, stop. */
10329 /* Now we're really doing the instantiation. Mark the type as in
10330 the process of being defined. */
10333 /* We may be in the middle of deferred access check. Disable
10334 it now. */
10341 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10346 else
10347 {
10350 }
10351 /* Use #pragma pack from the template context. */
10357 /* Set the input location to the most specialized template definition.
10358 This is needed if tsubsting causes an error. */
10370 {
10373 /* Adjust visibility for template arguments. */
10375 }
10381 /* We should never instantiate a nested class before its enclosing
10382 class; we need to look up the nested class by name before we can
10383 instantiate it, and that lookup should instantiate the enclosing
10384 class. */
10390 {
10391 tree pbase_binfo;
10392 tree pushed_scope;
10395 /* We must enter the scope containing the type, as that is where
10396 the accessibility of types named in dependent bases are
10397 looked up from. */
10400 /* Substitute into each of the bases to determine the actual
10401 basetypes. */
10403 {
10404 tree base;
10410 {
10411 expanded_bases =
10418 }
10421 {
10423 /* Extract the already-expanded base class. */
10425 else
10426 /* Substitute to figure out the base class. */
10428 NULL_TREE);
10436 }
10437 }
10439 /* The list is now in reverse order; correct that. */
10444 }
10445 /* Now call xref_basetypes to set up all the base-class
10446 information. */
10454 /* Now that our base classes are set up, enter the scope of the
10455 class, so that name lookups into base classes, etc. will work
10456 correctly. This is precisely analogous to what we do in
10457 begin_class_definition when defining an ordinary non-template
10458 class, except we also need to push the enclosing classes. */
10461 /* Now members are processed in the order of declaration. */
10464 {
10468 {
10470 {
10471 /* Build new CLASSTYPE_NESTED_UTDS. */
10473 tree newtag;
10479 /* If the member is a class template, then -- even after
10480 substitution -- there may be dependent types in the
10481 template argument list for the class. We increment
10482 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10483 that function will assume that no types are dependent
10484 when outside of a template. */
10494 {
10498 /* Unfortunately, lookup_template_class sets
10499 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10500 instantiation (i.e., for the type of a member
10501 template class nested within a template class.)
10502 This behavior is required for
10503 maybe_process_partial_specialization to work
10504 correctly, but is not accurate in this case;
10505 the TAG is not an instantiation of anything.
10506 (The corresponding TEMPLATE_DECL is an
10507 instantiation, but the TYPE is not.) */
10510 /* Now, we call pushtag to put this NEWTAG into the scope of
10511 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10512 pushtag calling push_template_decl. We don't have to do
10513 this for enums because it will already have been done in
10514 tsubst_enum. */
10518 }
10519 }
10521 {
10522 /* Build new TYPE_METHODS. */
10523 tree r;
10532 /* Instantiate members marked with attribute used. */
10538 }
10541 /* A closure type for a lambda in a default argument for a
10542 member template. Ignore it; it will be instantiated with
10544 else
10545 {
10546 /* Build new TYPE_FIELDS. */
10548 {
10549 tree condition;
10552 condition =
10562 }
10564 {
10565 tree r;
10569 /* The file and line for this declaration, to
10570 assist in error message reporting. Since we
10571 called push_tinst_level above, we don't need to
10572 restore these. */
10582 {
10583 /* A capture pack became multiple fields. */
10586 }
10589 {
10593 {
10594 /* In [temp.inst]:
10596 [t]he initialization (and any associated
10597 side-effects) of a static data member does
10598 not occur unless the static data member is
10599 itself used in a way that requires the
10600 definition of the static data member to
10601 exist.
10603 Therefore, we do not substitute into the
10604 initialized for the static data member here. */
10605 finish_static_data_member_decl
10611 /* Instantiate members marked with attribute used. */
10614 }
10616 {
10617 /* Determine whether R has a valid type and can be
10618 completed later. If R is invalid, then its type
10619 is replaced by error_mark_node. */
10625 {
10626 /* If R's type couldn't be completed and
10627 it isn't a flexible array member (whose
10628 type is incomplete by definition) give
10629 an error. */
10632 }
10633 }
10635 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10636 such a thing will already have been added to the field
10637 list by tsubst_enum in finish_member_declaration in the
10638 CLASSTYPE_NESTED_UTDS case above. */
10642 {
10645 }
10646 }
10647 }
10648 }
10649 }
10650 else
10651 {
10654 {
10655 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10661 {
10662 /* template <class T> friend class C; */
10665 }
10667 {
10668 /* template <class T> friend class C::D; */
10674 }
10677 {
10678 /* This could be either
10680 friend class T::C;
10682 when dependent_type_p is false or
10684 template <class U> friend class T::C;
10686 otherwise. */
10687 /* Bump processing_template_decl in case this is something like
10688 template <class T> friend struct A<T>::B. */
10695 }
10698 {
10699 /* friend class C;
10701 where C hasn't been declared yet. Let's lookup name
10702 from namespace scope directly, bypassing any name that
10703 come from dependent base class. */
10706 /* The call to xref_tag_from_type does injection for friend
10707 classes. */
10709 friend_type =
10713 }
10715 /* friend class C<T>; */
10718 /* Otherwise it's
10720 friend class C;
10722 where C is already declared or
10724 friend class C<int>;
10726 We don't have to do anything in these cases. */
10729 /* Trick make_friend_class into realizing that the friend
10730 we're adding is a template, not an ordinary class. It's
10731 important that we use make_friend_class since it will
10732 perform some error-checking and output cross-reference
10733 information. */
10741 }
10742 else
10743 {
10744 /* Build new DECL_FRIENDLIST. */
10745 tree r;
10747 /* The file and line for this declaration, to
10748 assist in error message reporting. Since we
10749 called push_tinst_level above, we don't need to
10750 restore these. */
10754 {
10757 }
10762 {
10765 }
10766 }
10767 }
10768 }
10771 {
10772 /* Restore these before substituting into the lambda capture
10773 initializers. */
10776 }
10779 {
10782 {
10788 {
10789 /* Set function_depth to avoid garbage collection. */
10793 }
10795 /* We need to instantiate the capture list from the template
10796 after we've instantiated the closure members, but before we
10797 consider adding the conversion op. Also keep any captures
10798 that may have been added during instantiation of the op(). */
10800 tree tmpl_cap
10809 }
10810 else
10812 }
10814 /* Set the file and line number information to whatever is given for
10815 the class itself. This puts error messages involving generated
10816 implicit functions at a predictable point, and the same point
10817 that would be used for non-template classes. */
10824 /* We don't instantiate default arguments for member functions. 14.7.1:
10826 The implicit instantiation of a class template specialization causes
10827 the implicit instantiation of the declarations, but not of the
10828 definitions or default arguments, of the class member functions,
10829 member classes, static data members and member templates.... */
10831 /* Some typedefs referenced from within the template code need to be access
10832 checked at template instantiation time, i.e now. These types were
10833 added to the template at parsing time. Let's get those and perform
10834 the access checks then. */
10844 /* The vtable for a template class can be emitted in any translation
10845 unit in which the class is instantiated. When there is no key
10846 method, however, finish_struct_1 will already have added TYPE to
10847 the keyed_classes list. */
10852 }
10854 /* Wrapper for instantiate_class_template_1. */
10856 tree
10858 {
10859 tree ret;
10864 }
10866 static tree
10868 {
10869 tree r;
10875 else
10876 {
10883 }
10885 }
10887 /* Given a function parameter pack TMPL_PARM and some function parameters
10888 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10889 and set *SPEC_P to point at the next point in the list. */
10891 tree
10893 {
10894 /* Collect all of the extra "packed" parameters into an
10895 argument pack. */
10896 tree parmvec;
10906 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10912 /* Build the argument packs. */
10917 }
10919 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10920 NONTYPE_ARGUMENT_PACK. */
10922 static tree
10924 {
10926 }
10928 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10929 pack expansion with no extra args, 2 if it has extra args, or 0
10930 if it is not a pack expansion. */
10932 static int
10934 {
10940 /* A decl pack is itself an expansion. */
10947 }
10950 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10952 static tree
10954 {
10961 }
10963 /* This is a subroutine of tsubst_pack_expansion.
10965 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10966 mechanism to store the (non complete list of) arguments of the
10967 substitution and return a non substituted pack expansion, in order
10968 to wait for when we have enough arguments to really perform the
10969 substitution. */
10971 static bool
10975 {
10976 /* If one pack has an expansion and another pack has a normal
10977 argument or if one pack has an empty argument and an another
10978 one hasn't then tsubst_pack_expansion cannot perform the
10979 substitution and need to fall back on the
10980 PACK_EXPANSION_EXTRA mechanism. */
10988 {
10991 parm_pack;
10993 {
10998 /* We can't substitute a pack expansion with extra args into
10999 our pattern. */
11003 else
11005 }
11009 }
11011 }
11013 /* [temp.variadic]/6 says that:
11015 The instantiation of a pack expansion [...]
11016 produces a list E1,E2, ..., En, where N is the number of elements
11017 in the pack expansion parameters.
11019 This subroutine of tsubst_pack_expansion produces one of these Ei.
11021 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11022 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11023 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11024 INDEX is the index 'i' of the element Ei to produce. ARGS,
11025 COMPLAIN, and IN_DECL are the same parameters as for the
11026 tsubst_pack_expansion function.
11028 The function returns the resulting Ei upon successful completion,
11029 or error_mark_node.
11031 Note that this function possibly modifies the ARGS parameter, so
11032 it's the responsibility of the caller to restore it. */
11034 static tree
11036 tree parm_packs,
11038 tree args /* This parm gets
11040 tsubst_flags_t complain,
11041 tree in_decl)
11042 {
11043 tree t;
11046 /* For each parameter pack, change the substitution of the parameter
11047 pack to the ith argument in its argument pack, then expand the
11048 pattern. */
11050 {
11055 ith_elem_is_expansion |=
11058 /* Select the Ith argument from the pack. */
11061 {
11063 {
11068 }
11069 else
11071 }
11072 else
11073 {
11078 {
11080 /* Update the corresponding argument. */
11082 }
11083 else
11084 /* Re-use the ARGUMENT_PACK_SELECT. */
11086 }
11088 }
11090 /* Substitute into the PATTERN with the (possibly altered)
11091 arguments. */
11093 /* Expanding a fixed parameter pack from
11094 coerce_template_parameter_pack. */
11099 {
11102 else
11105 }
11109 else
11112 /* If the Ith argument pack element is a pack expansion, then
11113 the Ith element resulting from the substituting is going to
11114 be a pack expansion as well. */
11119 }
11121 /* When the unexpanded parameter pack in a fold expression expands to an empty
11122 sequence, the value of the expression is as follows; the program is
11123 ill-formed if the operator is not listed in this table.
11125 && true
11126 || false
11127 , void() */
11129 tree
11131 {
11135 {
11144 }
11150 }
11152 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11153 form an expression that combines the two terms using the
11154 operator of T. */
11156 static tree
11158 {
11162 // Handle compound assignment operators.
11167 {
11177 complain);
11178 }
11179 }
11181 /* Substitute ARGS into the pack of a fold expression T. */
11185 {
11187 }
11189 /* Substitute ARGS into the pack of a fold expression T. */
11193 {
11195 }
11197 /* Expand a PACK of arguments into a grouped as left fold.
11198 Given a pack containing elements A0, A1, ..., An and an
11199 operator @, this builds the expression:
11201 ((A0 @ A1) @ A2) ... @ An
11203 Note that PACK must not be empty.
11205 The operator is defined by the original fold expression T. */
11207 static tree
11209 {
11212 {
11215 }
11217 }
11219 /* Substitute into a unary left fold expression. */
11221 static tree
11223 tree in_decl)
11224 {
11229 {
11233 }
11236 else
11238 }
11240 /* Substitute into a binary left fold expression.
11242 Do ths by building a single (non-empty) vector of argumnts and
11243 building the expression from those elements. */
11245 static tree
11247 tree in_decl)
11248 {
11257 {
11262 }
11270 }
11272 /* Expand a PACK of arguments into a grouped as right fold.
11273 Given a pack containing elementns A0, A1, ..., and an
11274 operator @, this builds the expression:
11276 A0@ ... (An-2 @ (An-1 @ An))
11278 Note that PACK must not be empty.
11280 The operator is defined by the original fold expression T. */
11282 tree
11284 {
11285 // Build the expression.
11289 {
11292 }
11294 }
11296 /* Substitute into a unary right fold expression. */
11298 static tree
11300 tree in_decl)
11301 {
11306 {
11310 }
11313 else
11315 }
11317 /* Substitute into a binary right fold expression.
11319 Do ths by building a single (non-empty) vector of arguments and
11320 building the expression from those elements. */
11322 static tree
11324 tree in_decl)
11325 {
11334 {
11339 }
11348 }
11351 /* Substitute ARGS into T, which is an pack expansion
11352 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11353 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11354 (if only a partial substitution could be performed) or
11355 ERROR_MARK_NODE if there was an error. */
11356 tree
11358 tree in_decl)
11359 {
11360 tree pattern;
11364 tree result;
11372 /* Add in any args remembered from an earlier partial instantiation. */
11377 /* Determine the argument packs that will instantiate the parameter
11378 packs used in the expansion expression. While we're at it,
11379 compute the number of arguments to be expanded and make sure it
11380 is consistent. */
11383 {
11390 {
11395 else
11398 }
11400 {
11401 /* ??? Support use in other patterns. */
11405 }
11407 {
11408 /* We know we have correct local_specializations if this
11409 expansion is at function scope, or if we're dealing with a
11410 local parameter in a requires expression; for the latter,
11411 tsubst_requires_expr set it up appropriately. */
11414 else
11415 /* We can't rely on local_specializations for a parameter
11416 name used later in a function declaration (such as in a
11417 late-specified return type). Even if it exists, it might
11418 have the wrong value for a recursive call. */
11422 {
11423 /* This parameter pack was used in an unevaluated context. Just
11424 make a dummy decl, since it's only used for its type. */
11427 /* Partial instantiation of the parm_pack, we can't build
11428 up an argument pack yet. */
11430 else
11432 }
11433 }
11436 else
11437 {
11443 }
11450 /* This can only happen if we forget to expand an argument
11451 pack somewhere else. Just return an error, silently. */
11452 {
11456 }
11459 {
11463 /* Don't bother trying to do a partial substitution with
11464 incomplete packs; we'll try again after deduction. */
11471 {
11476 pattern);
11477 else
11479 pattern);
11481 }
11483 /* Keep track of the parameter packs and their corresponding
11484 argument packs. */
11487 }
11488 else
11489 {
11490 /* We can't substitute for this parameter pack. We use a flag as
11491 well as the missing_level counter because function parameter
11492 packs don't have a level. */
11495 }
11496 }
11498 /* If the expansion is just T..., return the matching argument pack, unless
11499 we need to call convert_from_reference on all the elements. This is an
11500 important optimization; see c++/68422. */
11503 {
11505 /* Types need no adjustment, nor does sizeof..., and if we still have
11506 some pack expansion args we won't do anything yet. */
11511 /* Also optimize expression pack expansions if we can tell that the
11512 elements won't have reference type. */
11518 /* Otherwise use the normal path so we get convert_from_reference. */
11519 }
11521 /* We cannot expand this expansion expression, because we don't have
11522 all of the argument packs we need. */
11524 {
11525 /* We got some full packs, but we can't substitute them in until we
11526 have values for all the packs. So remember these until then. */
11531 }
11533 {
11534 /* There were no real arguments, we're just replacing a parameter
11535 pack with another version of itself. Substitute into the
11536 pattern and return a PACK_EXPANSION_*. The caller will need to
11537 deal with that. */
11541 else
11545 }
11550 {
11551 /* We're in a late-specified return type, so create our own local
11552 specializations map; the current map is either NULL or (in the
11553 case of recursive unification) might have bindings that we don't
11554 want to use or alter. */
11557 }
11559 /* For each argument in each argument pack, substitute into the
11560 pattern. */
11564 {
11566 i,
11568 in_decl);
11571 {
11574 }
11575 }
11577 /* Update ARGS to restore the substitution from parameter packs to
11578 their argument packs. */
11580 {
11586 else
11587 {
11595 /* Update the corresponding argument. */
11599 else
11601 }
11602 }
11605 {
11608 }
11610 /* If the dependent pack arguments were such that we end up with only a
11611 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11617 }
11619 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11620 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11621 parameter packs; all parms generated from a function parameter pack will
11622 have the same DECL_PARM_INDEX. */
11624 tree
11626 {
11628 tree patparm;
11631 {
11637 }
11638 else
11639 {
11644 }
11647 }
11649 /* Make an argument pack out of the TREE_VEC VEC. */
11651 static tree
11653 {
11654 tree pack;
11658 else
11659 {
11662 }
11665 }
11667 /* Return an exact copy of template args T that can be modified
11668 independently. */
11670 static tree
11672 {
11680 {
11685 }
11691 }
11693 /* Substitute ARGS into the vector or list of template arguments T. */
11695 static tree
11697 {
11709 {
11711 tree new_arg;
11716 {
11717 /* Substitute into an expansion expression. */
11721 /* Add to the expanded length adjustment the number of
11722 expanded arguments. We subtract one from this
11723 measurement, because the argument pack expression
11724 itself is already counted as 1 in
11725 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11726 the argument pack is empty. */
11728 }
11730 {
11731 /* Substitute into each of the arguments. */
11740 else
11745 }
11746 else
11755 }
11760 /* Make space for the expanded arguments coming from template
11761 argument packs. */
11763 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11764 arguments for a member template.
11765 In that case each TREE_VEC in ORIG_T represents a level of template
11766 arguments, and ORIG_T won't carry any non defaulted argument count.
11767 It will rather be the nested TREE_VECs that will carry one.
11768 In other words, ORIG_T carries a non defaulted argument count only
11769 if it doesn't contain any nested TREE_VEC. */
11771 {
11775 }
11777 {
11781 {
11784 /* Now expand the template argument pack "in place". */
11787 }
11788 else
11789 {
11791 out++;
11792 }
11793 }
11796 }
11798 /* Substitute ARGS into one level PARMS of template parameters. */
11800 static tree
11802 {
11809 {
11817 }
11820 }
11822 /* Return the result of substituting ARGS into the template parameters
11823 given by PARMS. If there are m levels of ARGS and m + n levels of
11824 PARMS, then the result will contain n levels of PARMS. For
11825 example, if PARMS is `template <class T> template <class U>
11826 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11827 result will be `template <int*, double, class V>'. */
11829 static tree
11831 {
11835 /* When substituting into a template, we must set
11836 PROCESSING_TEMPLATE_DECL as the template parameters may be
11837 dependent if they are based on one-another, and the dependency
11838 predicates are short-circuit outside of templates. */
11845 {
11852 }
11857 }
11859 /* Return the result of substituting ARGS into one template parameter
11860 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11861 parameter and which TREE_PURPOSE is the default argument of the
11862 template parameter. */
11864 static tree
11866 {
11887 }
11889 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11890 type T. If T is not an aggregate or enumeration type, it is
11891 handled as if by tsubst. IN_DECL is as for tsubst. If
11892 ENTERING_SCOPE is nonzero, T is the context for a template which
11893 we are presently tsubst'ing. Return the substituted value. */
11895 static tree
11897 tree args,
11898 tsubst_flags_t complain,
11899 tree in_decl,
11901 {
11906 {
11911 /* Fall through. */
11915 {
11916 tree argvec;
11917 tree context;
11918 tree r;
11922 /* In "sizeof(X<I>)" we need to evaluate "I". */
11928 /* First, determine the context for the type we are looking
11929 up. */
11932 {
11935 /* If context is a nested class inside a class template,
11936 it may still need to be instantiated (c++/33959). */
11938 }
11940 /* Then, figure out what arguments are appropriate for the
11941 type we are trying to find. For example, given:
11943 template <class T> struct S;
11944 template <class T, class U> void f(T, U) { S<U> su; }
11946 and supposing that we are instantiating f<int, double>,
11947 then our ARGS will be {int, double}, but, when looking up
11948 S we only want {double}. */
11953 else
11954 {
11958 }
11964 }
11965 else
11966 /* This is not a template type, so there's nothing to do. */
11971 }
11972 }
11974 /* Substitute into the default argument ARG (a default argument for
11975 FN), which has the indicated TYPE. */
11977 tree
11979 {
11984 /* This can happen in invalid code. */
11988 /* This default argument came from a template. Instantiate the
11989 default argument here, not in tsubst. In the case of
11990 something like:
11992 template <class T>
11993 struct S {
11994 static T t();
11995 void f(T = t());
11996 };
11998 we must be careful to do name lookup in the scope of S<T>,
11999 rather than in the current class. */
12001 /* The "this" pointer is not valid in a default argument. */
12003 {
12008 }
12011 /* The default argument expression may cause implicitly defined
12012 member functions to be synthesized, which will result in garbage
12013 collection. We must treat this situation as if we were within
12014 the body of function so as to avoid collecting live data on the
12015 stack. */
12023 /* Restore the "this" pointer. */
12025 {
12028 }
12035 /* Make sure the default argument is reasonable. */
12041 }
12043 /* Substitute into all the default arguments for FN. */
12045 static void
12047 {
12048 tree arg;
12049 tree tmpl_args;
12053 /* If this function is not yet instantiated, we certainly don't need
12054 its default arguments. */
12057 /* Don't do this again for clones. */
12062 arg;
12068 complain);
12069 }
12071 /* Substitute the ARGS into the T, which is a _DECL. Return the
12072 result of the substitution. Issue error and warning messages under
12073 control of COMPLAIN. */
12075 static tree
12077 {
12078 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12079 location_t saved_loc;
12084 /* Set the filename and linenumber to improve error-reporting. */
12089 {
12091 {
12092 /* We can get here when processing a member function template,
12093 member class template, or template template parameter. */
12095 tree spec;
12096 tree tmpl_args;
12097 tree full_args;
12100 {
12101 /* Template template parameter is treated here. */
12105 /* If we get a real template back, return it. This can happen in
12106 the context of most_specialized_partial_spec. */
12109 else
12110 /* The new TEMPLATE_DECL was built in
12111 reduce_template_parm_level. */
12114 }
12116 /* We might already have an instance of this template.
12117 The ARGS are for the surrounding class type, so the
12118 full args contain the tsubst'd args for the context,
12119 plus the innermost args from the template decl. */
12123 /* Because this is a template, the arguments will still be
12124 dependent, even after substitution. If
12125 PROCESSING_TEMPLATE_DECL is not set, the dependency
12126 predicates will short-circuit. */
12134 /* If this is a default template template argument,
12135 tsubst might not have changed anything. */
12142 {
12145 }
12147 /* Make a new template decl. It will be similar to the
12148 original, but will record the current template arguments.
12149 We also create a new function declaration, which is just
12150 like the old one, but points to this new template, rather
12151 than the old one. */
12156 // Build new template info linking to the original template decl.
12161 {
12162 tree new_type;
12170 /* For a partial specialization, we need to keep pointing to
12171 the primary template. */
12177 }
12178 else
12179 {
12180 tree new_decl;
12192 }
12198 /* The template parameters for this new template are all the
12199 template parameters for the old template, except the
12200 outermost level of parameters. */
12203 complain);
12209 /* Record this non-type partial instantiation. */
12213 }
12217 {
12218 tree ctx;
12221 tree gen_tmpl;
12222 tree type;
12227 /* Nobody should be tsubst'ing into non-template functions. */
12231 {
12232 tree spec;
12234 /* If T is not dependent, just return it. */
12238 /* Calculate the most general template of which R is a
12239 specialization, and the complete set of arguments used to
12240 specialize R. */
12243 (DECL_TEMPLATE_RESULT
12249 /* Check to see if we already have this specialization. */
12254 {
12257 }
12259 /* We can see more levels of arguments than parameters if
12260 there was a specialization of a member template, like
12261 this:
12263 template <class T> struct S { template <class U> void f(); }
12264 template <> template <class U> void S<int>::f(U);
12266 Here, we'll be substituting into the specialization,
12267 because that's where we can find the code we actually
12268 want to generate, but we'll have enough arguments for
12269 the most general template.
12271 We also deal with the peculiar case:
12273 template <class T> struct S {
12274 template <class U> friend void f();
12275 };
12276 template <class U> void f() {}
12277 template S<int>;
12278 template void f<double>();
12280 Here, the ARGS for the instantiation of will be {int,
12281 double}. But, we only need as many ARGS as there are
12282 levels of template parameters in CODE_PATTERN. We are
12283 careful not to get fooled into reducing the ARGS in
12284 situations like:
12286 template <class T> struct S { template <class U> void f(U); }
12287 template <class T> template <> void S<T>::f(int) {}
12289 which we can spot because the pattern will be a
12290 specialization in this case. */
12292 parms_depth =
12297 }
12298 else
12299 {
12300 /* This special case arises when we have something like this:
12302 template <class T> struct S {
12303 friend void f<int>(int, double);
12304 };
12306 Here, the DECL_TI_TEMPLATE for the friend declaration
12307 will be an IDENTIFIER_NODE. We are being called from
12308 tsubst_friend_function, and we want only to create a
12309 new decl (R) with appropriate types so that we can call
12310 determine_specialization. */
12312 }
12315 {
12318 else
12322 }
12323 else
12324 {
12327 }
12332 /* If we hit excessive deduction depth, the type is bogus even if
12333 it isn't error_mark_node, so don't build a decl. */
12337 /* We do NOT check for matching decls pushed separately at this
12338 point, as they may not represent instantiations of this
12339 template, and in any case are considered separate under the
12340 discrete model. */
12344 /* Clear out the mangled name and RTL for the instantiation. */
12347 /* Leave DECL_INITIAL set on deleted instantiations. */
12352 /* OpenMP UDRs have the only argument a reference to the declared
12353 type. We want to diagnose if the declared type is a reference,
12354 which is invalid, but as references to references are usually
12355 quietly merged, diagnose it here. */
12357 {
12358 tree argtype
12363 "reference type %qT in "
12367 argtype);
12368 }
12371 /* Type-conversion operator. Reconstruct the name, in
12372 case it's the name of one of the template's parameters. */
12382 /* If this is an instantiation of a function with internal
12383 linkage, we already know what object file linkage will be
12384 assigned to the instantiation. */
12393 /* We'll re-clone as appropriate in instantiate_template. */
12396 /* If we aren't complaining now, return on error before we register
12397 the specialization so that we'll complain eventually. */
12403 /* When instantiating a constrained member, substitute
12404 into the constraints to create a new constraint. */
12407 {
12410 }
12412 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12413 this in the special friend case mentioned above where
12414 GEN_TMPL is NULL. */
12416 {
12421 tree new_r
12424 /* We instantiated this while substituting into
12425 the type earlier (template/friend54.C). */
12428 /* We're not supposed to instantiate default arguments
12429 until they are called, for a template. But, for a
12430 declaration like:
12432 template <class T> void f ()
12433 { extern void g(int i = T()); }
12435 we should do the substitution when the template is
12436 instantiated. We handle the member function case in
12437 instantiate_class_template since the default arguments
12438 might refer to other members of the class. */
12443 }
12444 else
12447 /* Copy the list of befriending classes. */
12451 {
12455 in_decl);
12456 }
12459 {
12463 /* If this is an instantiation of a member template, clone it.
12464 If it isn't, that'll be handled by
12465 clone_constructors_and_destructors. */
12468 }
12479 /* Possibly limit visibility based on template args. */
12482 {
12486 }
12494 }
12498 {
12506 {
12507 /* If there is a local specialization that isn't a
12508 parameter pack, it means that we're doing a "simple"
12509 substitution from inside tsubst_pack_expansion. Just
12510 return the local specialization (which will be a single
12511 parm). */
12518 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12519 the parameters in this function parameter pack. */
12523 {
12526 /* Zero-length parameter packs are boring. Just substitute
12527 into the chain. */
12531 }
12532 else
12533 {
12534 /* All we did was update the type. Make a note of that. */
12537 }
12538 }
12540 /* Loop through all of the parameters we'll build. When T is
12541 a function parameter pack, LEN is the number of expanded
12542 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12545 {
12552 /* We're on the Ith parameter of the function parameter
12553 pack. */
12554 {
12555 /* Get the Ith type. */
12558 /* Rename the parameter to include the index. */
12561 }
12563 /* We're dealing with a normal parameter. */
12571 {
12574 else
12577 }
12587 /* Keep track of the first new parameter we
12588 generate. That's what will be returned to the
12589 caller. */
12593 /* Build a proper chain of parameters when substituting
12594 into a function parameter pack. */
12597 }
12599 /* If cp_unevaluated_operand is set, we're just looking for a
12600 single dummy parameter, so don't keep going. */
12605 /* FIRST_R contains the start of the chain we've built. */
12607 }
12611 {
12618 {
12619 /* This field is a lambda capture pack. Return a TREE_VEC of
12620 the expanded fields to instantiate_class_template_1 and
12621 store them in the specializations hash table as a
12622 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12626 {
12629 }
12630 else
12631 {
12632 /* All we did was update the type. Make a note of that. */
12635 }
12636 }
12639 {
12642 {
12646 }
12656 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12657 non-bit-fields DECL_INITIAL is a non-static data member
12658 initializer, which gets deferred instantiation. */
12664 {
12665 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12666 NSDMI in perform_member_init. Still set DECL_INITIAL
12667 so that we know there is one. */
12672 }
12673 /* We don't have to set DECL_CONTEXT here; it is set by
12674 finish_member_declaration. */
12682 }
12685 {
12690 }
12691 }
12695 /* We reach here only for member using decls. We also need to check
12696 uses_template_parms because DECL_DEPENDENT_P is not set for a
12697 using-declaration that designates a member of the current
12698 instantiation (c++/53549). */
12701 {
12705 {
12710 {
12714 {
12717 }
12718 else
12719 {
12722 }
12724 }
12725 }
12726 else
12727 {
12733 else
12734 {
12737 }
12738 }
12739 }
12740 else
12741 {
12744 }
12749 {
12752 tree spec;
12754 tree ctx;
12763 {
12764 /* If this is the canonical decl, we don't have to
12765 mess with instantiations, and often we can't (for
12766 typename, template type parms and such). Note that
12767 TYPE_NAME is not correct for the above test if
12768 we've copied the type for a typedef. */
12774 }
12776 /* Check to see if we already have the specialization we
12777 need. */
12780 {
12781 /* T is a static data member or namespace-scope entity.
12782 We have to substitute into namespace-scope variables
12783 (not just variable templates) because of cases like:
12785 template <class T> void f() { extern T t; }
12787 where the entity referenced is not known until
12788 instantiation time. */
12792 {
12794 complain,
12796 /* If CTX is unchanged, then T is in fact the
12797 specialization we want. That situation occurs when
12798 referencing a static data member within in its own
12799 class. We can use pointer equality, rather than
12800 same_type_p, because DECL_CONTEXT is always
12801 canonical... */
12803 /* ... unless T is a member template; in which
12804 case our caller can be willing to create a
12805 specialization of that template represented
12806 by T. */
12810 }
12813 {
12818 argvec = (coerce_innermost_template_parms
12826 }
12827 }
12828 else
12829 {
12830 /* A local variable. */
12832 /* Subsequent calls to pushdecl will fill this in. */
12834 /* Unless this is a reference to a static variable from an
12835 enclosing function, in which case we need to fill it in now. */
12837 {
12841 }
12843 }
12844 /* If we already have the specialization we need, there is
12845 nothing more to do. */
12847 {
12850 }
12852 /* Create a new node for the specialization we need. */
12855 {
12858 else
12865 }
12867 {
12868 /* Even if the original location is out of scope, the
12869 newly substituted one is not. */
12876 {
12877 /* It may seem that this case cannot occur, since:
12879 typedef void f();
12880 void g() { f x; }
12882 declares a function, not a variable. However:
12884 typedef void f();
12885 template <typename T> void g() { T t; }
12886 template void g<f>();
12888 is an attempt to declare a variable with function
12889 type. */
12891 /* R is not yet sufficiently initialized, so we
12892 just use its name. */
12895 }
12897 /* Wait until cp_finish_decl to set this again, to handle
12898 circular dependency (template/instantiate6.C). */
12903 {
12908 {
12911 }
12913 }
12917 }
12923 /* Clear out the mangled name and RTL for the instantiation. */
12927 /* The initializer must not be expanded until it is required;
12928 see [temp.inst]. */
12936 {
12937 /* Possibly limit visibility based on template args. */
12940 {
12944 }
12946 }
12949 {
12950 /* A static data member declaration is always marked
12951 external when it is declared in-class, even if an
12952 initializer is present. We mimic the non-template
12953 processing here. */
12961 }
12962 else
12963 {
12968 }
12976 /* Preserve a typedef that names a type. */
12978 {
12982 /* An alias template specialization can be dependent
12983 even if its underlying type is not. */
12985 }
12988 }
12993 }
12994 #undef RETURN
12996 out:
12997 /* Restore the file and line information. */
13001 }
13003 /* Substitute into the ARG_TYPES of a function type.
13004 If END is a TREE_CHAIN, leave it and any following types
13005 un-substituted. */
13007 static tree
13009 tree args,
13010 tree end,
13011 tsubst_flags_t complain,
13012 tree in_decl)
13013 {
13014 tree remaining_arg_types;
13018 tree default_arg;
13029 {
13030 /* For a pack expansion, perform substitution on the
13031 entire expression. Later on, we'll handle the arguments
13032 one-by-one. */
13037 /* So that we'll spin through the parameters, one by one. */
13039 else
13040 {
13041 /* We only partially substituted into the parameter
13042 pack. Our type is TYPE_PACK_EXPANSION. */
13045 }
13046 }
13059 {
13061 {
13065 }
13067 }
13068 /* DR 657. */
13072 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13073 top-level qualifiers as required. */
13076 /* We do not substitute into default arguments here. The standard
13077 mandates that they be instantiated only when needed, which is
13078 done in build_over_call. */
13082 {
13083 /* We've instantiated a template before its default arguments
13084 have been parsed. This can happen for a nested template
13085 class, and is not an error unless we require the default
13086 argument in a call of this function. */
13087 remaining_arg_types =
13090 }
13091 else
13092 remaining_arg_types =
13094 }
13097 }
13099 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13100 *not* handle the exception-specification for FNTYPE, because the
13101 initial substitution of explicitly provided template parameters
13102 during argument deduction forbids substitution into the
13103 exception-specification:
13105 [temp.deduct]
13107 All references in the function type of the function template to the
13108 corresponding template parameters are replaced by the specified tem-
13109 plate argument values. If a substitution in a template parameter or
13110 in the function type of the function template results in an invalid
13111 type, type deduction fails. [Note: The equivalent substitution in
13112 exception specifications is done only when the function is instanti-
13113 ated, at which point a program is ill-formed if the substitution
13114 results in an invalid type.] */
13116 static tree
13118 tree args,
13119 tsubst_flags_t complain,
13120 tree in_decl)
13121 {
13122 tree return_type;
13124 tree fntype;
13126 /* The TYPE_CONTEXT is not used for function/method types. */
13129 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13130 failure. */
13134 {
13135 /* Substitute the argument types. */
13147 {
13148 /* DR 1207: 'this' is in scope in the trailing return type. */
13150 }
13152 /* Substitute the return type. */
13156 {
13159 }
13160 }
13161 else
13162 /* Substitute the return type. */
13167 /* DR 486 clarifies that creation of a function type with an
13168 invalid return type is a deduction failure. */
13171 {
13173 {
13176 else
13178 }
13180 }
13181 /* And DR 657. */
13186 {
13187 /* Substitute the argument types. */
13192 }
13194 /* Construct a new type node and return it. */
13196 {
13201 }
13202 else
13203 {
13205 /* Don't pick up extra function qualifiers from the basetype. */
13208 {
13209 /* [temp.deduct]
13211 Type deduction may fail for any of the following
13212 reasons:
13214 -- Attempting to create "pointer to member of T" when T
13215 is not a class type. */
13218 r);
13220 }
13225 }
13232 }
13234 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13235 ARGS into that specification, and return the substituted
13236 specification. If there is no specification, return NULL_TREE. */
13238 static tree
13240 tree args,
13241 tsubst_flags_t complain,
13242 tree in_decl,
13244 {
13245 tree specs;
13246 tree new_specs;
13251 {
13252 /* A noexcept-specifier. */
13257 {
13258 /* Defer instantiation of noexcept-specifiers to avoid
13259 excessive instantiations (c++/49107). */
13262 {
13263 /* We already partially instantiated this member template,
13264 so combine the new args with the old. */
13269 }
13270 else
13271 {
13274 }
13275 }
13276 else
13277 new_specs = tsubst_copy_and_build
13281 }
13283 {
13286 else
13288 {
13289 tree spec;
13294 {
13295 /* Expand the pack expansion type. */
13298 in_decl);
13304 else
13305 {
13306 /* We're substituting into a member template, so
13307 we got a TYPE_PACK_EXPANSION back. Add that
13308 expansion and move on. */
13312 expanded_specs,
13313 complain);
13316 }
13317 }
13320 {
13323 else
13328 complain);
13329 }
13332 }
13333 }
13335 }
13337 /* Take the tree structure T and replace template parameters used
13338 therein with the argument vector ARGS. IN_DECL is an associated
13339 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13340 Issue error and warning messages under control of COMPLAIN. Note
13341 that we must be relatively non-tolerant of extensions here, in
13342 order to preserve conformance; if we allow substitutions that
13343 should not be allowed, we may allow argument deductions that should
13344 not succeed, and therefore report ambiguous overload situations
13345 where there are none. In theory, we could allow the substitution,
13346 but indicate that it should have failed, and allow our caller to
13347 make sure that the right thing happens, but we don't try to do this
13348 yet.
13350 This function is used for dealing with types, decls and the like;
13351 for expressions, use tsubst_expr or tsubst_copy. */
13353 tree
13355 {
13378 else
13383 /* Reuse typedefs. We need to do this to handle dependent attributes,
13384 such as attribute aligned. */
13387 {
13391 {
13392 /* DECL represents an alias template and we want to
13393 instantiate it. */
13397 }
13401 {
13405 }
13410 else
13411 /* The typedef is from a non-template context. */
13415 {
13417 r = cp_build_qualified_type_real
13421 }
13422 else
13423 {
13424 /* We don't have an instantiation yet, so drop the typedef. */
13429 }
13430 }
13447 {
13473 {
13479 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13480 needed. */
13486 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13487 with TREE_SIDE_EFFECTS that indicates this is not an integral
13488 constant expression. */
13491 {
13494 }
13497 }
13503 {
13509 /* Early in template argument deduction substitution, we don't
13510 want to reduce the level of 'auto', or it will be confused
13511 with a normal template parm in subsequent deduction. */
13523 {
13527 {
13528 /* See through ARGUMENT_PACK_SELECT arguments. */
13530 /* If the selected argument is an expansion E, that most
13531 likely means we were called from
13532 gen_elem_of_pack_expansion_instantiation during the
13533 substituting of pack an argument pack (which Ith
13534 element is a pack expansion, where I is
13535 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13536 In this case, the Ith element resulting from this
13537 substituting is going to be a pack expansion, which
13538 pattern is the pattern of E. Let's return the
13539 pattern of E, and
13540 gen_elem_of_pack_expansion_instantiation will
13541 build the resulting pack expansion from it. */
13543 {
13544 /* Make sure we aren't throwing away arg info. */
13547 }
13548 }
13549 }
13554 {
13556 /* If ARG is an argument pack, we don't actually want to
13557 perform a substitution here, because substitutions
13558 for argument packs are only done
13559 element-by-element. We can get to this point when
13560 substituting the type of a non-type template
13561 parameter pack, when that type actually contains
13562 template parameter packs from an outer template, e.g.,
13564 template<typename... Types> struct A {
13565 template<Types... Values> struct B { };
13566 }; */
13570 {
13576 return cp_build_qualified_type_real
13578 }
13580 {
13581 /* We are processing a type constructed from a
13582 template template parameter. */
13593 /* Consider this code:
13595 template <template <class> class Template>
13596 struct Internal {
13597 template <class Arg> using Bind = Template<Arg>;
13598 };
13600 template <template <class> class Template, class Arg>
13601 using Instantiate = Template<Arg>; //#0
13603 template <template <class> class Template,
13604 class Argument>
13605 using Bind =
13606 Instantiate<Internal<Template>::template Bind,
13607 Argument>; //#1
13609 When #1 is parsed, the
13610 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13611 parameter `Template' in #0 matches the
13612 UNBOUND_CLASS_TEMPLATE representing the argument
13613 `Internal<Template>::template Bind'; We then want
13614 to assemble the type `Bind<Argument>' that can't
13615 be fully created right now, because
13616 `Internal<Template>' not being complete, the Bind
13617 template cannot be looked up in that context. So
13618 we need to "store" `Bind<Argument>' for later
13619 when the context of Bind becomes complete. Let's
13620 store that in a TYPENAME_TYPE. */
13624 argvec),
13625 typename_type,
13626 complain);
13628 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13629 are resolving nested-types in the signature of a
13630 member function templates. Otherwise ARG is a
13631 TEMPLATE_DECL and is the real template to be
13632 instantiated. */
13640 complain);
13641 return cp_build_qualified_type_real
13643 }
13646 else
13647 /* TEMPLATE_PARM_INDEX. */
13649 }
13652 /* This can happen during the attempted tsubst'ing in
13653 unify. This means that we don't yet have any information
13654 about the template parameter in question. */
13657 /* If we get here, we must have been looking at a parm for a
13658 more deeply nested template. Make a new version of this
13659 template parameter, but with a lower level. */
13661 {
13666 {
13668 r = cp_build_qualified_type_real
13672 }
13679 /* Break infinite recursion when substituting the constraints
13681 else
13682 {
13693 {
13694 /* Propagate constraints on placeholders. */
13699 {
13703 }
13704 }
13707 /* We have reduced the level of the template
13708 template parameter, but not the levels of its
13709 template parameters, so canonical_type_parameter
13710 will not be able to find the canonical template
13711 template parameter for this level. Thus, we
13712 require structural equality checking to compare
13713 TEMPLATE_TEMPLATE_PARMs. */
13717 else
13721 {
13723 /* We might need to substitute into the types of non-type
13724 template parameters. */
13736 }
13737 }
13741 /* OK, now substitute the type of the non-type parameter. We
13742 couldn't do it earlier because it might be an auto parameter,
13743 and we wouldn't need to if we had an argument. */
13750 }
13753 }
13756 {
13764 {
13768 }
13771 {
13775 }
13778 {
13782 }
13788 }
13791 /* We should never be tsubsting a binfo. */
13795 /* A vector of template arguments. */
13801 {
13805 /* [temp.deduct]
13807 Type deduction may fail for any of the following
13808 reasons:
13810 -- Attempting to create a pointer to reference type.
13811 -- Attempting to create a reference to a reference type or
13812 a reference to void.
13814 Core issue 106 says that creating a reference to a reference
13815 during instantiation is no longer a cause for failure. We
13816 only enforce this check in strict C++98 mode. */
13820 {
13823 /* We keep track of the last time we issued this error
13824 message to avoid spewing a ton of messages during a
13825 single bad template instantiation. */
13828 {
13833 else
13836 }
13839 }
13843 {
13845 {
13848 type);
13849 else
13851 type);
13852 }
13854 }
13856 {
13860 }
13862 /* In C++0x, during template argument substitution, when there is an
13863 attempt to create a reference to a reference type, reference
13864 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13866 "If a template-argument for a template-parameter T names a type
13867 that is a reference to a type A, an attempt to create the type
13868 'lvalue reference to cv T' creates the type 'lvalue reference to
13869 A,' while an attempt to create the type type rvalue reference to
13870 cv T' creates the type T"
13871 */
13872 r = cp_build_reference_type
13875 else
13880 /* Will this ever be needed for TYPE_..._TO values? */
13884 }
13886 {
13889 {
13890 /* [temp.deduct]
13892 Type deduction may fail for any of the following
13893 reasons:
13895 -- Attempting to create "pointer to member of T" when T
13896 is not a class type. */
13900 }
13902 {
13906 }
13908 {
13912 }
13915 {
13916 /* The type of the implicit object parameter gets its
13917 cv-qualifiers from the FUNCTION_TYPE. */
13918 tree memptr;
13919 tree method_type
13924 complain);
13925 }
13926 else
13929 complain);
13930 }
13933 {
13934 tree fntype;
13935 tree specs;
13940 /* Substitute the exception specification. */
13948 }
13950 {
13955 /* As an optimization, we avoid regenerating the array type if
13956 it will obviously be the same as T. */
13960 /* These checks should match the ones in create_array_type_for_decl.
13962 [temp.deduct]
13964 The deduction may fail for any of the following reasons:
13966 -- Attempting to create an array with an element type that
13967 is void, a function type, or a reference type, or [DR337]
13968 an abstract class type. */
13974 {
13978 }
13986 {
13989 }
13992 }
13995 {
14007 {
14011 }
14013 {
14014 /* Normally, make_typename_type does not require that the CTX
14015 have complete type in order to allow things like:
14017 template <class T> struct S { typename S<T>::X Y; };
14019 But, such constructs have already been resolved by this
14020 point, so here CTX really should have complete type, unless
14021 it's a partial instantiation. */
14024 {
14028 }
14029 }
14036 {
14039 }
14042 {
14044 {
14048 else
14050 }
14052 {
14056 else
14058 }
14059 }
14061 return cp_build_qualified_type_real
14063 }
14066 {
14078 }
14081 {
14082 tree type;
14098 complain);
14099 }
14102 {
14103 tree type;
14114 {
14116 {
14120 }
14123 }
14134 else
14135 {
14139 /* In a template ~id could be either a complement expression
14140 or an unqualified-id naming a destructor; if instantiating
14141 it produces an expression, it's not an id-expression or
14142 member access. */
14145 }
14150 }
14153 {
14157 }
14161 {
14162 tree r;
14166 else
14174 }
14189 /* We should use one of the expression tsubsts for these codes. */
14195 }
14196 }
14198 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
14199 type of the expression on the left-hand side of the "." or "->"
14200 operator. */
14202 static tree
14205 {
14206 tree name;
14207 tree qualifying_scope;
14208 tree fns;
14209 tree optype;
14214 /* A baselink indicates a function from a base class. Both the
14215 BASELINK_ACCESS_BINFO and the base class referenced may
14216 indicate bases of the template class, rather than the
14217 instantiated class. In addition, lookups that were not
14218 ambiguous before may be ambiguous now. Therefore, we perform
14219 the lookup again. */
14226 {
14233 }
14239 {
14241 {
14245 }
14247 }
14249 /* If lookup found a single function, mark it as used at this
14250 point. (If it lookup found multiple functions the one selected
14251 later by overload resolution will be marked as used at that
14252 point.) */
14259 /* Add back the template arguments, if present. */
14263 unknown_type_node,
14265 template_args);
14266 /* Update the conversion operator type. */
14274 {
14276 qualifying_scope,
14277 object_type);
14279 /* We need to call adjust_result_of_qualified_name_lookup in case the
14280 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14281 so that we still get virtual function binding. */
14283 }
14285 }
14287 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14288 true if the qualified-id will be a postfix-expression in-and-of
14289 itself; false if more of the postfix-expression follows the
14290 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14291 of "&". */
14293 static tree
14297 {
14298 tree expr;
14299 tree scope;
14300 tree name;
14302 tree template_args;
14307 /* Figure out what name to look up. */
14310 {
14320 }
14321 else
14322 {
14325 }
14327 /* Substitute into the qualifying scope. When there are no ARGS, we
14328 are just trying to simplify a non-dependent expression. In that
14329 case the qualifying scope may be dependent, and, in any case,
14330 substituting will not help. */
14333 {
14336 }
14337 else
14341 {
14348 }
14351 {
14353 {
14354 /* A BIT_NOT_EXPR is used to represent a destructor. */
14356 {
14360 }
14361 else
14364 }
14365 else
14369 {
14371 {
14375 }
14377 }
14378 }
14381 {
14383 scope);
14384 /* Remember that there was a reference to this entity. */
14387 }
14390 {
14396 }
14399 {
14402 complain);
14403 else
14405 }
14411 {
14412 expr = (adjust_result_of_qualified_name_lookup
14414 expr = (finish_qualified_id_expr
14418 }
14420 /* Expressions do not generally have reference type. */
14422 /* However, if we're about to form a pointer-to-member, we just
14423 want the referenced member referenced. */
14431 }
14433 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14434 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14435 for tsubst. */
14437 static tree
14440 {
14447 {
14448 /* If we had an initializer but it
14449 instantiated to nothing,
14450 value-initialize the object. This will
14451 only occur when the initializer was a
14452 pack expansion where the parameter packs
14453 used in that expansion were of length
14454 zero. */
14456 complain);
14461 }
14464 }
14466 /* Like tsubst, but deals with expressions. This function just replaces
14467 template parms; to finish processing the resultant expression, use
14468 tsubst_copy_and_build or tsubst_expr. */
14470 static tree
14472 {
14474 tree r;
14482 {
14487 {
14488 /* We get here for a use of 'this' in an NSDMI as part of a
14489 constructor call or as part of an aggregate initialization. */
14491 && ((current_function_decl
14493 || (current_class_ref
14497 /* This can happen for a parameter name used later in a function
14498 declaration (such as in a late-specified return type). Just
14499 make a dummy decl, since it's only used for its type. */
14502 /* Give it the template pattern as its context; its true context
14503 hasn't been instantiated yet and this is good enough for
14504 mangling. */
14506 }
14515 {
14516 tree enum_type;
14517 tree v;
14521 /* There is no need to substitute into namespace-scope
14522 enumerators. */
14525 /* If ARGS is NULL, then T is known to be non-dependent. */
14529 /* Unfortunately, we cannot just call lookup_name here.
14530 Consider:
14532 template <int I> int f() {
14533 enum E { a = I };
14534 struct S { void g() { E e = a; } };
14535 };
14537 When we instantiate f<7>::S::g(), say, lookup_name is not
14538 clever enough to find f<7>::a. */
14539 enum_type
14549 /* We didn't find the name. That should never happen; if
14550 name-lookup found it during preliminary parsing, we
14551 should find it again here during instantiation. */
14553 }
14558 {
14559 /* Check for a local specialization set up by
14560 tsubst_pack_expansion. */
14562 {
14566 }
14568 /* When retrieving a capture pack from a generic lambda, remove the
14569 lambda call op's own template argument list from ARGS. Only the
14570 template arguments active for the closure type should be used to
14571 retrieve the pack specialization. */
14577 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14578 tsubst_decl put in the hash table. */
14580 }
14583 {
14584 tree ctx;
14589 {
14592 {
14596 }
14598 }
14599 }
14609 {
14612 {
14613 /* First try name lookup to find the instantiation. */
14616 {
14617 /* Make sure that the one we found is the one we want. */
14623 }
14627 else
14628 {
14629 /* This can happen for a variable used in a
14630 late-specified return type of a local lambda, or for a
14631 local static or constant. Building a new VAR_DECL
14632 should be OK in all those cases. */
14635 /* Avoid infinite recursion (79640). */
14638 {
14639 /* We can't call cp_finish_decl, so handle the
14640 initializer by hand. */
14651 }
14658 }
14659 /* Remember this for subsequent uses. */
14662 }
14663 }
14664 else
14674 /* An OVERLOAD will always be a non-dependent overload set; an
14675 overload set from function scope will just be represented with an
14676 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14678 /* We must have marked any lookups as persistent. */
14694 {
14695 /* Template template argument like the following example need
14696 special treatment:
14698 template <template <class> class TT> struct C {};
14699 template <class T> struct D {
14700 template <class U> struct E {};
14701 C<E> c; // #1
14702 };
14703 D<int> d; // #2
14705 We are processing the template argument `E' in #1 for
14706 the template instantiation #2. Originally, `E' is a
14707 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14708 have to substitute this with one having context `D<int>'. */
14712 {
14713 /* When rewriting a constructor into a deduction guide, a
14714 non-dependent name can become dependent, so memtmpl<args>
14715 becomes context::template memtmpl<args>. */
14719 }
14721 }
14722 else
14723 /* Ordinary template template argument. */
14734 {
14738 }
14743 {
14752 /* We only want to compute the number of arguments. */
14755 else
14762 {
14764 /* Set TREE_USED for the benefit of -Wunused. */
14768 }
14776 {
14781 else
14787 else
14790 }
14791 else
14793 }
14795 {
14803 }
14804 /* Fall through */
14820 {
14824 }
14827 {
14828 tree object;
14829 tree name;
14834 {
14838 }
14841 {
14851 }
14856 in_decl);
14857 else
14860 }
14898 {
14902 }
14905 {
14910 }
14913 {
14917 }
14920 {
14928 }
14934 {
14941 }
14944 {
14951 }
14954 {
14961 }
14964 {
14965 /* Substituted template arguments */
14974 }
14977 {
14997 }
15022 /* Fall through. */
15025 {
15028 }
15029 else
15033 /* This is handled by tsubst_copy_and_build. */
15037 {
15041 }
15044 /* We shouldn't have built any of these during initial template
15045 generation. Instead, they should be built during instantiation
15046 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15050 {
15060 }
15078 {
15079 /* Instantiate any typedefs in the type. */
15084 }
15087 /* These can sometimes show up in a partial instantiation, but never
15088 involve template parms. */
15102 /* We shouldn't get here, but keep going if !flag_checking. */
15106 }
15107 }
15109 /* Helper function for tsubst_omp_clauses, used for instantiation of
15110 OMP_CLAUSE_DECL of clauses. */
15112 static tree
15114 tree in_decl)
15115 {
15119 /* Handle an OpenMP array section represented as a TREE_LIST (or
15120 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15121 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15122 TREE_LIST. We can handle it exactly the same as an array section
15123 (purpose, value, and a chain), even though the nomenclature
15124 (low_bound, length, etc) is different. */
15126 {
15127 tree low_bound
15133 in_decl);
15142 }
15145 /* Undo convert_from_reference tsubst_expr could have called. */
15151 }
15153 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15155 static tree
15158 {
15163 {
15169 {
15172 {
15178 }
15179 /* FALLTHRU */
15194 in_decl);
15226 {
15229 {
15236 }
15237 else
15239 }
15242 in_decl);
15248 in_decl);
15256 in_decl);
15258 {
15261 }
15266 else
15269 in_decl,
15293 }
15296 {
15306 /* tsubst_expr on SCOPE_REF results in returning
15307 finish_non_static_data_member result. Undo that here. */
15311 {
15316 {
15320 CASE_CONVERT:
15329 /* FALLTHRU */
15333 }
15334 }
15340 {
15343 {
15346 }
15347 }
15351 }
15352 }
15356 {
15361 {
15364 }
15365 }
15367 }
15369 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15371 static tree
15373 tree in_decl)
15374 {
15375 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15395 {
15398 else
15399 {
15403 }
15404 }
15409 #undef RECUR
15410 }
15412 /* Used to temporarily communicate the list of #pragma omp parallel
15413 clauses to #pragma omp for instantiation if they are combined
15414 together. */
15418 /* Substitute one OMP_FOR iterator. */
15420 static void
15425 {
15426 #define RECUR(NODE) \
15427 tsubst_expr ((NODE), args, complain, in_decl, \
15428 integral_constant_expression_p)
15435 {
15438 }
15444 {
15445 /* We need to jump through some hoops to handle declarations in the
15446 init-statement, since we might need to handle auto deduction,
15447 but we need to keep control of initialization. */
15451 }
15452 else
15453 {
15455 {
15458 {
15462 {
15466 CASE_CONVERT:
15474 {
15477 }
15478 /* FALLTHRU */
15482 }
15483 }
15484 }
15485 else
15487 }
15498 {
15500 {
15501 /* Declare the variable, but don't let that initialize it. */
15506 }
15511 {
15516 }
15517 else
15524 }
15527 {
15528 /* Declare and initialize the variable. */
15531 }
15533 {
15537 {
15539 {
15545 {
15548 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15553 }
15556 {
15558 decl);
15560 }
15563 {
15565 decl);
15567 }
15568 else
15570 }
15573 }
15575 {
15580 {
15583 }
15584 }
15585 }
15588 {
15592 }
15593 else
15597 {
15608 {
15616 }
15617 else
15623 {
15629 }
15633 {
15641 }
15642 else
15648 }
15654 #undef RECUR
15655 }
15657 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15658 of OMP_TARGET's body. */
15660 static tree
15662 {
15665 {
15674 }
15676 }
15678 /* Helper function for tsubst_expr. For decomposition declaration
15679 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15680 also the corresponding decls representing the identifiers
15681 of the decomposition declaration. Return DECL if successful
15682 or error_mark_node otherwise, set *FIRST to the first decl
15683 in the list chained through DECL_CHAIN and *CNT to the number
15684 of such decls. */
15686 static tree
15690 {
15695 decl2
15700 {
15702 {
15705 }
15722 {
15725 }
15726 else
15728 }
15731 }
15733 /* Like tsubst_copy for expressions, etc. but also does semantic
15734 processing. */
15736 tree
15739 {
15740 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15741 #define RECUR(NODE) \
15742 tsubst_expr ((NODE), args, complain, in_decl, \
15743 integral_constant_expression_p)
15746 tree r;
15747 location_t loc;
15759 {
15761 {
15762 tree_stmt_iterator i;
15766 }
15781 else
15791 {
15793 tree init;
15799 {
15809 else
15811 }
15813 {
15814 /* Don't build up decls for a variadic capture proxy, we'll
15815 instantiate the elements directly as needed. */
15817 }
15818 else
15819 {
15823 {
15824 /* By marking the declaration as instantiated, we avoid
15825 trying to instantiate it. Since instantiate_decl can't
15826 handle local variables, and since we've already done
15827 all that needs to be done, that's the right thing to
15828 do. */
15833 /* Anonymous aggregates are a special case. */
15836 {
15839 {
15843 }
15845 }
15851 {
15856 }
15857 else
15858 {
15863 {
15864 /* For __PRETTY_FUNCTION__ we have to adjust the
15865 initializer. */
15869 }
15870 else
15874 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15880 {
15882 tree first;
15888 }
15889 }
15890 }
15891 }
15894 }
15909 {
15917 {
15919 tree first;
15924 }
15925 else
15930 }
15956 else
15957 {
15964 }
15970 {
15979 }
15987 else
15995 else
16016 {
16023 }
16027 {
16029 tree label;
16036 }
16042 /* Computed goto's must be tsubst'd into. On the other hand,
16043 non-computed gotos must not be; the identifier in question
16044 will have no binding. */
16046 else
16052 {
16068 }
16073 {
16078 }
16079 else
16080 {
16085 else
16092 else
16098 else
16100 }
16104 {
16108 {
16110 /* Prevent instantiate_decl from trying to instantiate
16111 this variable. We've already done all that needs to be
16112 done. */
16115 }
16120 }
16126 {
16127 /* Local classes are not independent templates; they are
16128 instantiated along with their containing function. And this
16129 way we don't have to deal with pushing out of one local class
16130 to instantiate a member of another local class. */
16131 tree fn;
16132 /* Closures are handled by the LAMBDA_EXPR. */
16139 }
16143 {
16144 tree condition;
16147 condition =
16149 args,
16158 }
16164 in_decl);
16201 {
16216 in_decl);
16218 {
16225 }
16237 integral_constant_expression_p);
16248 else
16249 {
16257 }
16261 }
16266 /* FALLTHRU */
16273 in_decl);
16290 in_decl);
16301 {
16304 {
16305 /* For combined target teams, ensure the num_teams and
16306 thread_limit clause expressions are evaluated on the host,
16307 before entering the target construct. */
16308 tree c;
16314 {
16323 OMP_CLAUSE_FIRSTPRIVATE);
16327 }
16328 }
16329 }
16389 {
16394 {
16397 }
16403 }
16404 else
16405 {
16412 {
16415 }
16418 {
16423 {
16426 }
16432 }
16433 else
16434 {
16438 }
16441 }
16445 {
16451 {
16455 {
16460 }
16464 }
16465 else
16466 {
16471 }
16472 }
16476 {
16480 }
16500 /* If the first operand was a statement, we're done with it. */
16504 complain));
16516 integral_constant_expression_p));
16517 }
16520 out:
16523 #undef RECUR
16524 #undef RETURN
16525 }
16527 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16528 function. For description of the body see comment above
16529 cp_parser_omp_declare_reduction_exprs. */
16531 static void
16533 {
16539 tree_stmt_iterator tsi;
16550 {
16569 }
16571 {
16591 }
16592 }
16594 /* T is a postfix-expression that is not being used in a function
16595 call. Return the substituted version of T. */
16597 static tree
16599 tsubst_flags_t complain,
16600 tree in_decl)
16601 {
16605 else
16611 }
16613 /* Like tsubst but deals with expressions and performs semantic
16614 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16616 tree
16618 tree args,
16619 tsubst_flags_t complain,
16620 tree in_decl,
16623 {
16624 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16625 #define RECUR(NODE) \
16626 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16628 integral_constant_expression_p)
16631 location_t loc;
16640 /* N3276 decltype magic only applies to calls at the top level or on the
16641 right side of a comma. */
16646 {
16649 /* Fall through. */
16651 {
16652 tree decl;
16653 cp_id_kind idk;
16658 {
16661 }
16663 /* Look up the name. */
16666 /* By convention, expressions use ERROR_MARK_NODE to indicate
16667 failure, not NULL_TREE. */
16673 integral_constant_expression_p,
16681 input_location);
16685 {
16689 }
16691 }
16694 {
16695 tree object;
16705 {
16710 }
16716 {
16719 }
16720 else
16727 else
16729 }
16732 {
16736 {
16737 /* A type conversion to reference type will be enclosed in
16738 such an indirect ref, but the substitution of the cast
16739 will have also added such an indirect ref. */
16742 }
16743 else
16751 }
16754 {
16758 }
16761 {
16768 flags));
16769 }
16772 {
16776 }
16783 {
16784 tree type;
16790 {
16795 }
16801 {
16819 }
16822 }
16856 else
16858 in_decl);
16893 {
16900 tree r = build_x_binary_op
16902 op0,
16904 ? ERROR_MARK
16906 op1,
16908 ? ERROR_MARK
16916 }
16919 {
16923 }
16936 {
16945 }
16950 /* Fall through */
16953 {
16954 tree r;
16960 {
16961 /* When there are no ARGS, we are trying to evaluate a
16962 non-dependent expression from the parser. Trying to do
16963 the substitutions may not work. */
16966 }
16967 else
16968 {
16973 else
16976 /*integral_constant_expression_p=*/
16980 }
16984 else
16988 {
16990 {
16992 {
16996 }
16997 else
17001 }
17003 }
17005 }
17008 {
17018 }
17034 {
17038 tree r = build_x_modify_expr
17041 /* TREE_NO_WARNING must be set if either the expression was
17042 parenthesized or it uses an operator such as >>= rather
17043 than plain assignment. In the former case, it was already
17044 set and must be copied. In the latter case,
17045 build_x_modify_expr sets it and it must not be reset
17046 here. */
17051 }
17056 /* Remember that there was a reference to this entity. */
17063 {
17068 tree ret;
17072 else
17073 {
17077 }
17079 /* If there was an initializer in the original tree, but it
17080 instantiated to an empty list, then we should pass a
17081 non-NULL empty vector to tell build_new that it was an
17082 empty initializer() rather than no initializer. This can
17083 only happen when the initializer is a pack expansion whose
17084 parameter packs are of length zero. */
17087 else
17088 {
17092 else
17093 {
17096 }
17097 }
17103 complain);
17111 }
17114 {
17120 complain));
17121 }
17124 {
17128 integral_constant_expression_p);
17130 op0,
17133 }
17136 {
17137 tree function;
17142 tree ret;
17145 /* Internal function with no arguments. */
17149 /* When we parsed the expression, we determined whether or
17150 not Koenig lookup should be performed. */
17153 {
17156 }
17158 {
17163 }
17165 {
17166 /* Do nothing; calling tsubst_copy_and_build on an identifier
17167 would incorrectly perform unqualified lookup again.
17169 Note that we can also have an IDENTIFIER_NODE if the earlier
17170 unqualified lookup found a member function; in that case
17171 koenig_p will be false and we do want to do the lookup
17172 again to find the instantiated member function.
17174 FIXME but doing that causes c++/15272, so we need to stop
17175 using IDENTIFIER_NODE in that situation. */
17177 }
17178 else
17179 {
17181 {
17187 }
17188 else
17193 /* Avoid error about taking the address of a constructor. */
17197 in_decl,
17199 integral_constant_expression_p);
17203 }
17208 {
17213 else
17214 {
17215 /* Expand the pack expansion and push each entry onto
17216 CALL_ARGS. */
17219 {
17224 {
17229 }
17230 }
17231 else
17232 {
17233 /* A partial substitution. Add one entry. */
17235 }
17236 }
17237 }
17239 /* We do not perform argument-dependent lookup if normal
17240 lookup finds a non-function, in accordance with the
17241 expected resolution of DR 218. */
17244 /* If lookup found a member function, the Koenig lookup is
17245 not appropriate, even if an unqualified-name was used
17246 to denote the function. */
17249 /* Only do this when substitution turns a dependent call
17250 into a non-dependent call. */
17258 {
17260 {
17261 /* For backwards compatibility and good diagnostics, try
17262 the unqualified lookup again if we aren't in SFINAE
17263 context. */
17264 tree unq = (tsubst_copy_and_build
17266 integral_constant_expression_p));
17268 {
17271 }
17274 {
17275 /* In a lambda fn, we have to be careful to not
17276 introduce new this captures. Legacy code can't
17277 be using lambdas anyway, so it's ok to be
17278 stricter. */
17283 "and no declarations were found by "
17284 "argument-dependent lookup at the point "
17291 else
17295 {
17306 {
17308 input_location);
17310 "declarations in dependent base %qT are "
17316 else
17320 }
17321 else
17323 "%qD declared here, later in the "
17326 {
17329 }
17330 }
17333 }
17334 }
17336 {
17341 }
17342 }
17344 /* Remember that there was a reference to this entity. */
17348 {
17351 }
17353 /* Put back tf_decltype for the actual call. */
17358 {
17362 {
17364 "wrong number of arguments to "
17367 }
17368 else
17370 input_location),
17375 /* Unsupported internal function with arguments. */
17377 }
17380 complain);
17382 {
17397 complain);
17398 else
17399 ret = (build_new_method_call
17404 complain));
17405 }
17406 else
17409 koenig_p,
17410 complain);
17415 {
17421 {
17427 {
17429 /* The thunk location is not interesting. */
17431 }
17432 }
17433 }
17436 }
17439 {
17445 {
17447 {
17452 }
17453 else
17454 {
17459 }
17461 }
17462 else
17463 {
17466 }
17470 }
17473 {
17478 input_location));
17479 }
17482 {
17490 {
17491 /* We have pack expansions, so expand those and
17492 create a new list out of it. */
17495 tree chain;
17498 /* Expand the argument expressions. */
17506 /* Build the rest of the list. */
17511 /* Determine the number of arguments. */
17513 {
17516 }
17519 else
17520 {
17521 /* Since we only performed a partial substitution into
17522 the argument pack, we only RETURN (a single list
17523 node. */
17530 }
17532 /* Convert the argument vectors into a TREE_LIST */
17535 {
17536 /* Grab the Ith values. */
17537 i--;
17540 value
17544 /* Build the list (backwards). */
17546 }
17549 }
17565 }
17568 {
17569 tree object;
17570 tree object_type;
17571 tree member;
17572 tree r;
17576 /* Remember that there was a reference to this entity. */
17587 else
17593 {
17598 }
17602 {
17604 {
17609 {
17612 }
17614 {
17619 }
17620 }
17621 }
17624 {
17625 /* Lookup the template functions now that we know what the
17626 scope is. */
17634 {
17637 args);
17638 member = (adjust_result_of_qualified_name_lookup
17640 object_type));
17641 }
17642 else
17643 {
17645 input_location);
17647 }
17648 }
17652 {
17654 {
17658 else
17661 }
17663 }
17667 complain);
17671 }
17678 {
17686 tree r;
17691 /* digest_init will do the wrong thing if we let it. */
17695 /* We do not want to process the index of aggregate
17696 initializers as they are identifier nodes which will be
17697 looked up by digest_init. */
17703 {
17705 /* An identifier index is looked up in the type
17706 being initialized, not the current scope. */
17711 {
17712 /* Substitute into the pack expansion. */
17714 in_decl);
17718 ;
17720 /* Just move the argument into place. */
17722 else
17723 {
17724 /* Update the length of the final CONSTRUCTOR
17725 arguments vector, and note that we will need to
17726 copy.*/
17729 }
17730 }
17731 else
17733 }
17736 {
17741 {
17743 {
17748 }
17749 else
17751 }
17752 }
17758 {
17763 }
17767 }
17770 {
17773 {
17776 }
17777 else
17778 {
17781 }
17782 }
17788 {
17789 /* We don't build decls for an instantiation of a
17790 variadic capture proxy, we instantiate the elements
17791 when needed. */
17794 }
17795 /* Fall through */
17798 {
17800 /* ??? We're doing a subset of finish_id_expression here. */
17802 && !processing_template_decl
17803 && !cp_unevaluated_operand
17806 {
17808 /* Replace an evaluated use of the thread_local variable with
17809 a call to its wrapper. */
17811 }
17813 {
17817 }
17820 /* If the original type was a reference, we'll be wrapped in
17821 the appropriate INDIRECT_REF. */
17824 }
17827 {
17831 }
17834 {
17835 tree object_ptr
17842 }
17849 {
17860 }
17863 {
17869 integral_constant_expression_p);
17873 /* If the resulting list of expression statement is empty,
17874 fold it further into void_node. */
17879 }
17882 {
17900 /* For a function or variable scope, we want to use tsubst so that we
17901 don't complain about referring to an auto before deduction. */
17904 {
17905 /* Look up the parameter we want directly, as tsubst_copy
17906 doesn't do what we need. */
17912 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17915 }
17917 /* For a field, use tsubst_copy so that we look up the existing field
17918 rather than build a new one. */
17920 else
17927 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17929 /* Now that we know visibility, instantiate the type so we have a
17930 declaration of the op() for later calls to lambda_function. */
17941 }
17944 /* We can get here for a constant initializer of non-dependent type.
17945 FIXME stop folding in cp_parser_initializer_clause. */
17946 {
17948 complain);
17950 }
17954 integral_constant_expression_p));
17960 {
17965 complain));
17966 }
17972 /* Handle Objective-C++ constructs, if appropriate. */
17973 {
17974 tree subst
17979 }
17981 }
17983 #undef RECUR
17984 #undef RETURN
17985 out:
17988 }
17990 /* Verify that the instantiated ARGS are valid. For type arguments,
17991 make sure that the type's linkage is ok. For non-type arguments,
17992 make sure they are constants if they are integral or enumerations.
17993 Emit an error under control of COMPLAIN, and return TRUE on error. */
17995 static bool
17997 {
18001 {
18011 }
18013 {
18014 /* [basic.link]: A name with no linkage (notably, the name
18015 of a class or enumeration declared in a local scope)
18016 shall not be used to declare an entity with linkage.
18017 This implies that names with no linkage cannot be used as
18018 template arguments
18020 DR 757 relaxes this restriction for C++0x. */
18025 {
18026 /* DR 488 makes use of a type with no linkage cause
18027 type deduction to fail. */
18029 {
18032 else
18035 }
18037 }
18038 /* In order to avoid all sorts of complications, we do not
18039 allow variably-modified types as template arguments. */
18041 {
18045 }
18046 }
18047 /* Class template and alias template arguments should be OK. */
18049 ;
18050 /* A non-type argument of integral or enumerated type must be a
18051 constant. */
18056 {
18060 }
18062 }
18064 static bool
18066 {
18071 {
18074 }
18078 }
18080 /* We're out of SFINAE context now, so generate diagnostics for the access
18081 errors we saw earlier when instantiating D from TMPL and ARGS. */
18083 static void
18085 {
18097 }
18099 /* Instantiate the indicated variable, function, or alias template TMPL with
18100 the template arguments in TARG_PTR. */
18102 static tree
18104 {
18106 tree fndecl;
18107 tree gen_tmpl;
18108 tree spec;
18116 /* If this function is a clone, handle it specially. */
18118 {
18119 tree spec;
18120 tree clone;
18122 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18123 DECL_CLONED_FUNCTION. */
18129 /* Look for the clone. */
18133 /* We should always have found the clone by now. */
18136 }
18141 /* Check to see if we already have this specialization. */
18145 /* targ_ptr only has the innermost template args, so add the outer ones
18146 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18147 the case of a non-dependent call within a template definition). */
18148 targ_ptr = (add_outermost_template_args
18150 targ_ptr));
18152 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18153 but it doesn't seem to be on the hot path. */
18162 {
18164 {
18168 }
18170 }
18173 complain))
18176 /* We are building a FUNCTION_DECL, during which the access of its
18177 parameters and return types have to be checked. However this
18178 FUNCTION_DECL which is the desired context for access checking
18179 is not built yet. We solve this chicken-and-egg problem by
18180 deferring all checks until we have the FUNCTION_DECL. */
18183 /* Instantiation of the function happens in the context of the function
18184 template, not the context of the overload resolution we're doing. */
18186 /* If there are dependent arguments, e.g. because we're doing partial
18187 ordering, make sure processing_template_decl stays set. */
18191 {
18195 }
18201 {
18202 /* We need to determine if we're using a partial or explicit
18203 specialization now, because the type of the variable could be
18204 different. */
18210 {
18215 }
18216 }
18218 /* Substitute template parameters to obtain the specialization. */
18226 {
18229 }
18231 /* The DECL_TI_TEMPLATE should always be the immediate parent
18232 template, not the most general template. */
18236 /* Now we know the specialization, compute access previously
18237 deferred. Do no access control for inheriting constructors,
18238 as we already checked access for the inherited constructor. */
18241 {
18246 }
18249 /* If we've just instantiated the main entry point for a function,
18250 instantiate all the alternate entry points as well. We do this
18251 by cloning the instantiation of the main entry point, not by
18252 instantiating the template clones. */
18257 {
18259 {
18260 /* Remember to reinstantiate when we're out of SFINAE so the user
18261 can see the errors. */
18263 }
18265 }
18267 }
18269 /* Wrapper for instantiate_template_1. */
18271 tree
18273 {
18274 tree ret;
18279 }
18281 /* Instantiate the alias template TMPL with ARGS. Also push a template
18282 instantiation level, which instantiate_template doesn't do because
18283 functions and variables have sufficient context established by the
18284 callers. */
18286 static tree
18288 {
18295 {
18298 }
18300 args =
18308 /* We can't free this if a pending_template entry or last_error_tinst_level
18309 is pointing at it. */
18315 }
18317 /* PARM is a template parameter pack for FN. Returns true iff
18318 PARM is used in a deducible way in the argument list of FN. */
18320 static bool
18322 {
18325 {
18327 tree packs;
18333 {
18334 /* The template parameter pack is used in a function parameter
18335 pack. If this is the end of the parameter list, the
18336 template parameter pack is deducible. */
18339 else
18340 /* Otherwise, not. Well, it could be deduced from
18341 a non-pack parameter, but doing so would end up with
18342 a deduction mismatch, so don't bother. */
18344 }
18345 }
18346 /* The template parameter pack isn't used in any function parameter
18347 packs, but it might be used deeper, e.g. tuple<Args...>. */
18349 }
18351 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18352 NARGS elements of the arguments that are being used when calling
18353 it. TARGS is a vector into which the deduced template arguments
18354 are placed.
18356 Returns either a FUNCTION_DECL for the matching specialization of FN or
18357 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18358 true, diagnostics will be printed to explain why it failed.
18360 If FN is a conversion operator, or we are trying to produce a specific
18361 specialization, RETURN_TYPE is the return type desired.
18363 The EXPLICIT_TARGS are explicit template arguments provided via a
18364 template-id.
18366 The parameter STRICT is one of:
18368 DEDUCE_CALL:
18369 We are deducing arguments for a function call, as in
18370 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18371 deducing arguments for a call to the result of a conversion
18372 function template, as in [over.call.object].
18374 DEDUCE_CONV:
18375 We are deducing arguments for a conversion function, as in
18376 [temp.deduct.conv].
18378 DEDUCE_EXACT:
18379 We are deducing arguments when doing an explicit instantiation
18380 as in [temp.explicit], when determining an explicit specialization
18381 as in [temp.expl.spec], or when taking the address of a function
18382 template, as in [temp.deduct.funcaddr]. */
18384 tree
18386 tree explicit_targs,
18387 tree targs,
18390 tree return_type,
18391 unification_kind_t strict,
18395 {
18396 tree parms;
18397 tree fntype;
18410 tree tinst;
18416 full_targs = (add_outermost_template_args
18418 targs));
18423 /* In C++0x, it's possible to have a function template whose type depends
18424 on itself recursively. This is most obvious with decltype, but can also
18425 occur with enumeration scope (c++/48969). So we need to catch infinite
18426 recursion and reject the substitution at deduction time; this function
18427 will return error_mark_node for any repeated substitution.
18429 This also catches excessive recursion such as when f<N> depends on
18430 f<N-1> across all integers, and returns error_mark_node for all the
18431 substitutions back up to the initial one.
18433 This is, of course, not reentrant. */
18443 {
18444 /* [temp.deduct]
18446 The specified template arguments must match the template
18447 parameters in kind (i.e., type, nontype, template), and there
18448 must not be more arguments than there are parameters;
18449 otherwise type deduction fails.
18451 Nontype arguments must match the types of the corresponding
18452 nontype template parameters, or must be convertible to the
18453 types of the corresponding nontype parameters as specified in
18454 _temp.arg.nontype_, otherwise type deduction fails.
18456 All references in the function type of the function template
18457 to the corresponding template parameters are replaced by the
18458 specified template argument values. If a substitution in a
18459 template parameter or in the function type of the function
18460 template results in an invalid type, type deduction fails. */
18471 explicit_targs);
18473 /* Adjust any explicit template arguments before entering the
18474 substitution context. */
18475 explicit_targs
18477 complain,
18483 /* Substitute the explicit args into the function type. This is
18484 necessary so that, for instance, explicitly declared function
18485 arguments can match null pointed constants. If we were given
18486 an incomplete set of explicit args, we must not do semantic
18487 processing during substitution as we could create partial
18488 instantiations. */
18490 {
18495 /* Dig out the actual parm. */
18498 {
18501 }
18503 {
18506 }
18509 /* No explicit argument for this template parameter. */
18513 {
18514 /* Mark the argument pack as "incomplete". We could
18515 still deduce more arguments during unification.
18516 We remove this mark in type_unification_real. */
18518 {
18522 }
18524 /* We have some incomplete argument packs. */
18526 }
18527 }
18531 {
18534 }
18537 /* Ignore any access checks; we'll see them again in
18538 instantiate_template and they might have the wrong
18539 access path at this point. */
18551 /* Place the explicitly specified arguments in TARGS. */
18555 }
18557 /* Never do unification on the 'this' parameter. */
18561 {
18562 /* We're deducing for a call to the result of a template conversion
18563 function. The parms we really want are in return_type. */
18567 }
18569 {
18578 }
18580 /* We allow incomplete unification without an error message here
18581 because the standard doesn't seem to explicitly prohibit it. Our
18582 callers must be ready to deal with unification failures in any
18583 event. */
18586 /* If we aren't explaining yet, push tinst context so we can see where
18587 any errors (e.g. from class instantiations triggered by instantiation
18588 of default template arguments) come from. If we are explaining, this
18589 context is redundant. */
18591 {
18594 }
18596 /* type_unification_real will pass back any access checks from default
18597 template argument substitution. */
18609 /* Now that we have bindings for all of the template arguments,
18610 ensure that the arguments deduced for the template template
18611 parameters have compatible template parameter lists. We cannot
18612 check this property before we have deduced all template
18613 arguments, because the template parameter types of a template
18614 template parameter might depend on prior template parameters
18615 deduced after the template template parameter. The following
18616 ill-formed example illustrates this issue:
18618 template<typename T, template<T> class C> void f(C<5>, T);
18620 template<int N> struct X {};
18622 void g() {
18623 f(X<5>(), 5l); // error: template argument deduction fails
18624 }
18626 The template parameter list of 'C' depends on the template type
18627 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18628 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18629 time that we deduce 'C'. */
18632 {
18635 }
18637 /* All is well so far. Now, check:
18639 [temp.deduct]
18641 When all template arguments have been deduced, all uses of
18642 template parameters in nondeduced contexts are replaced with
18643 the corresponding deduced argument values. If the
18644 substitution results in an invalid type, as described above,
18645 type deduction fails. */
18648 {
18651 }
18653 /* Also collect access checks from the instantiation. */
18666 /* Now perform any access checks encountered during substitution. */
18673 /* If we're looking for an exact match, check that what we got
18674 is indeed an exact match. It might not be if some template
18675 parameters are used in non-deduced contexts. But don't check
18676 for an exact match if we have dependent template arguments;
18677 in that case we're doing partial ordering, and we already know
18678 that we have two candidates that will provide the actual type. */
18680 {
18684 tree sarg
18690 {
18694 }
18695 }
18697 /* After doing deduction with the inherited constructor, actually return an
18698 instantiation of the inheriting constructor. */
18704 fail:
18707 {
18709 /* Reset once we're all the way out. */
18711 }
18713 /* We can't free this if a pending_template entry or last_error_tinst_level
18714 is pointing at it. */
18720 }
18722 /* Adjust types before performing type deduction, as described in
18723 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18724 sections are symmetric. PARM is the type of a function parameter
18725 or the return type of the conversion function. ARG is the type of
18726 the argument passed to the call, or the type of the value
18727 initialized with the result of the conversion function.
18728 ARG_EXPR is the original argument expression, which may be null. */
18730 static int
18734 tree arg_expr)
18735 {
18739 {
18744 /* Swap PARM and ARG throughout the remainder of this
18745 function; the handling is precisely symmetric since PARM
18746 will initialize ARG rather than vice versa. */
18751 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18752 too, but here handle it by stripping the reference from PARM
18753 rather than by adding it to ARG. */
18761 /* Nothing else to do in this case. */
18766 }
18769 {
18770 /* [temp.deduct.call]
18772 If P is not a reference type:
18774 --If A is an array type, the pointer type produced by the
18775 array-to-pointer standard conversion (_conv.array_) is
18776 used in place of A for type deduction; otherwise,
18778 --If A is a function type, the pointer type produced by
18779 the function-to-pointer standard conversion
18780 (_conv.func_) is used in place of A for type deduction;
18781 otherwise,
18783 --If A is a cv-qualified type, the top level
18784 cv-qualifiers of A's type are ignored for type
18785 deduction. */
18790 else
18792 }
18794 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18795 reference to a cv-unqualified template parameter that does not represent a
18796 template parameter of a class template (during class template argument
18797 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18798 an lvalue, the type "lvalue reference to A" is used in place of A for type
18799 deduction. */
18806 /* try_one_overload doesn't provide an arg_expr, but
18807 functions are always lvalues. */
18811 /* [temp.deduct.call]
18813 If P is a cv-qualified type, the top level cv-qualifiers
18814 of P's type are ignored for type deduction. If P is a
18815 reference type, the type referred to by P is used for
18816 type deduction. */
18819 {
18822 }
18824 /* DR 322. For conversion deduction, remove a reference type on parm
18825 too (which has been swapped into ARG). */
18830 }
18832 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18833 template which does contain any deducible template parameters; check if
18834 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18835 unify_one_argument. */
18837 static int
18840 {
18841 tree type;
18845 else
18852 {
18856 }
18858 {
18863 }
18867 else
18869 }
18873 /* Returns true iff the expression EXPR is one from which a template
18874 argument can be deduced. In other words, if it's an undecorated
18875 use of a template non-type parameter. */
18877 static bool
18879 {
18880 /* Strip implicit conversions. */
18884 }
18886 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18887 deducible way; that is, if it has a max value of <PARM> - 1. */
18889 static bool
18891 {
18900 }
18902 /* Returns true iff the template arguments ARGS use a template parameter
18903 in a deducible way. */
18905 static bool
18907 {
18909 {
18914 else
18915 {
18922 else
18924 }
18927 }
18929 }
18931 /* Returns true iff TYPE contains any deducible references to template
18932 parameters, as per 14.8.2.5. */
18934 static bool
18936 {
18940 /* T
18941 cv-list T
18942 TT<T>
18943 TT<i>
18944 TT<> */
18949 /* T*
18950 T&
18951 T&& */
18955 /* T[integer-constant ]
18956 type [i] */
18961 /* T type ::*
18962 type T::*
18963 T T::*
18964 T (type ::*)()
18965 type (T::*)()
18966 type (type ::*)(T)
18967 type (T::*)(T)
18968 T (type ::*)(T)
18969 T (T::*)()
18970 T (T::*)(T) */
18973 || (uses_deducible_template_parms
18976 /* template-name <T> (where template-name refers to a class template)
18977 template-name <i> (where template-name refers to a class template) */
18984 /* type (T)
18985 T()
18986 T(T) */
18989 {
18998 }
19001 }
19003 /* Subroutine of type_unification_real and unify_pack_expansion to
19004 handle unification of a single P/A pair. Parameters are as
19005 for those functions. */
19007 static int
19011 {
19018 /* We can't deduce anything from this, but we might get all the
19019 template args from other function args. */
19022 /* Implicit conversions (Clause 4) will be performed on a function
19023 argument to convert it to the type of the corresponding function
19024 parameter if the parameter type contains no template-parameters that
19025 participate in template argument deduction. */
19028 /* For function parameters with no deducible template parameters,
19029 just return. We'll check non-dependent conversions later. */
19033 {
19035 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19036 | UNIFY_ALLOW_MORE_CV_QUAL
19050 }
19052 /* We only do these transformations if this is the top-level
19053 parameter_type_list in a call or declaration matching; in other
19054 situations (nested function declarators, template argument lists) we
19055 won't be comparing a type to an expression, and we don't do any type
19056 adjustments. */
19058 {
19060 {
19063 {
19064 /* [temp.deduct.type] A template-argument can be
19065 deduced from a pointer to function or pointer
19066 to member function argument if the set of
19067 overloaded functions does not contain function
19068 templates and at most one of a set of
19069 overloaded functions provides a unique
19070 match. */
19077 }
19083 }
19085 arg_strict |=
19087 }
19088 else
19093 /* For deduction from an init-list we need the actual list. */
19097 }
19099 /* for_each_template_parm callback that always returns 0. */
19101 static int
19103 {
19105 }
19107 /* for_each_template_parm any_fn callback to handle deduction of a template
19108 type argument from the type of an array bound. */
19110 static int
19112 {
19120 {
19126 }
19128 /* Keep walking. */
19130 }
19132 /* Try to deduce any not-yet-deduced template type arguments from the type of
19133 an array bound. This is handled separately from unify because 14.8.2.5 says
19134 "The type of a type parameter is only deduced from an array bound if it is
19135 not otherwise deduced." */
19137 static void
19139 {
19144 }
19146 /* Most parms like fn_type_unification.
19148 If SUBR is 1, we're being called recursively (to unify the
19149 arguments of a function or method parameter of a function
19150 template).
19152 CHECKS is a pointer to a vector of access checks encountered while
19153 substituting default template arguments. */
19155 static int
19157 tree full_targs,
19158 tree xparms,
19162 unification_kind_t strict,
19166 {
19171 tree parms;
19182 /* Reset the number of non-defaulted template arguments contained
19183 in TARGS. */
19186 again:
19194 {
19199 /* For a function parameter pack that occurs at the end of the
19200 parameter-declaration-list, the type A of each remaining
19201 argument of the call is compared with the type P of the
19202 declarator-id of the function parameter pack. */
19208 /* For a function parameter pack that does not occur at the
19209 end of the parameter-declaration-list, the type of the
19210 parameter pack is a non-deduced context. */
19217 explain_p))
19219 }
19224 {
19225 /* Unify the remaining arguments with the pack expansion type. */
19226 tree argvec;
19229 /* Allocate a TREE_VEC and copy in all of the arguments */
19234 /* Copy the parameter into parmvec. */
19240 /* Advance to the end of the list of parameters. */
19242 }
19244 /* Fail if we've reached the end of the parm list, and more args
19245 are present, and the parm list isn't variadic. */
19248 /* Fail if parms are left and they don't have default values and
19249 they aren't all deduced as empty packs (c++/57397). This is
19250 consistent with sufficient_parms_p. */
19253 {
19257 do
19258 {
19261 count++;
19263 }
19267 type_pack_p);
19268 }
19271 {
19272 tsubst_flags_t complain = (explain_p
19273 ? tf_warning_or_error
19278 {
19282 /* Clear the "incomplete" flags on all argument packs now so that
19283 substituting them into later default arguments works. */
19285 {
19288 }
19296 {
19301 }
19303 /* If this is an undeduced nontype parameter that depends on
19304 a type parameter, try another pass; its type may have been
19305 deduced from a later argument than the one from which
19306 this parameter can be deduced. */
19310 {
19313 }
19315 /* Core issue #226 (C++0x) [temp.deduct]:
19317 If a template argument has not been deduced, its
19318 default template argument, if any, is used.
19320 When we are in C++98 mode, TREE_PURPOSE will either
19321 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19322 to explicitly check cxx_dialect here. */
19324 /* OK, there is a default argument. Wait until after the
19325 conversion check to do substitution. */
19328 /* If the type parameter is a parameter pack, then it will
19329 be deduced to an empty parameter pack. */
19331 {
19332 tree arg;
19335 {
19338 }
19339 else
19346 }
19349 }
19351 /* DR 1391: All parameters have args, now check non-dependent parms for
19352 convertibility. */
19356 {
19362 /* For a function parameter pack that occurs at the end of the
19363 parameter-declaration-list, the type A of each remaining
19364 argument of the call is compared with the type P of the
19365 declarator-id of the function parameter pack. */
19371 /* For a function parameter pack that does not occur at the
19372 end of the parameter-declaration-list, the type of the
19373 parameter pack is a non-deduced context. */
19382 explain_p))
19384 }
19386 /* Now substitute into the default template arguments. */
19388 {
19412 else
19420 {
19422 /* The position of the first default template argument,
19423 is also the number of non-defaulted arguments in TARGS.
19424 Record that. */
19427 }
19428 }
19432 }
19438 }
19440 /* Subroutine of type_unification_real. Args are like the variables
19441 at the call site. ARG is an overloaded function (or template-id);
19442 we try deducing template args from each of the overloads, and if
19443 only one succeeds, we go with that. Modifies TARGS and returns
19444 true on success. */
19446 static bool
19448 tree targs,
19449 tree parm,
19450 tree arg,
19451 unification_kind_t strict,
19454 {
19461 {
19464 }
19465 else
19469 /* Handle `&x' where `x' is some static or non-static member
19470 function name. */
19476 /* Strip baselink information. */
19481 {
19482 /* If we got some explicit template args, we need to plug them into
19483 the affected templates before we try to unify, in case the
19484 explicit args will completely resolve the templates in question. */
19491 {
19504 {
19509 {
19512 }
19513 }
19516 }
19517 /* If no templates (or more than one) are fully resolved by the
19518 explicit arguments, this template-id is a non-deduced context; it
19519 could still be OK if we deduce all template arguments for the
19520 enclosing call through other arguments. */
19523 }
19526 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19527 -- but the deduction does not succeed because the expression is
19528 not just the function on its own. */
19530 else
19532 {
19537 {
19540 }
19541 }
19543 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19544 to function or pointer to member function argument if the set of
19545 overloaded functions does not contain function templates and at most
19546 one of a set of overloaded functions provides a unique match.
19548 So if we found multiple possibilities, we return success but don't
19549 deduce anything. */
19552 {
19556 {
19561 /* Don't forget explicit template arguments in a pack. */
19565 }
19566 }
19571 }
19573 /* Core DR 115: In contexts where deduction is done and fails, or in
19574 contexts where deduction is not done, if a template argument list is
19575 specified and it, along with any default template arguments, identifies
19576 a single function template specialization, then the template-id is an
19577 lvalue for the function template specialization. */
19579 tree
19581 {
19594 {
19597 }
19599 {
19602 }
19604 {
19607 }
19610 {
19614 /* If we got some explicit template args, we need to plug them into
19615 the affected templates before we try to unify, in case the
19616 explicit args will completely resolve the templates in question. */
19624 {
19637 {
19640 {
19643 }
19645 {
19648 }
19649 }
19650 }
19652 {
19660 {
19661 tree base
19664 }
19668 }
19670 /* There were no good options and at least one bad one, so let the
19671 user know what the problem is. */
19673 }
19675 }
19677 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19678 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19679 different overloads deduce different arguments for a given parm.
19680 ADDR_P is true if the expression for which deduction is being
19681 performed was of the form "& fn" rather than simply "fn".
19683 Returns 1 on success. */
19685 static int
19687 tree orig_targs,
19688 tree targs,
19689 tree parm,
19690 tree arg,
19691 unification_kind_t strict,
19695 {
19697 tree tempargs;
19703 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19704 to function or pointer to member function argument if the set of
19705 overloaded functions does not contain function templates and at most
19706 one of a set of overloaded functions provides a unique match.
19708 So if this is a template, just return success. */
19720 /* We don't copy orig_targs for this because if we have already deduced
19721 some template args from previous args, unify would complain when we
19722 try to deduce a template parameter for the same argument, even though
19723 there isn't really a conflict. */
19730 /* First make sure we didn't deduce anything that conflicts with
19731 explicitly specified args. */
19733 {
19740 /* Since we're unifying against ourselves, we will fill in
19741 template args used in the function parm list with our own
19742 template parms. Discard them. */
19745 {
19746 /* Check that the argument at each index of the deduced argument pack
19747 is equivalent to the corresponding explicitly specified argument.
19748 We may have deduced more arguments than were explicitly specified,
19749 and that's OK. */
19751 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19752 that's wrong if we deduce the same argument pack from multiple
19753 function arguments: it's only incomplete the first time. */
19766 }
19769 }
19772 {
19777 }
19780 }
19782 /* PARM is a template class (perhaps with unbound template
19783 parameters). ARG is a fully instantiated type. If ARG can be
19784 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19785 TARGS are as for unify. */
19787 static tree
19790 {
19791 tree copy_of_targs;
19801 /* We need to make a new template argument vector for the call to
19802 unify. If we used TARGS, we'd clutter it up with the result of
19803 the attempted unification, even if this class didn't work out.
19804 We also don't want to commit ourselves to all the unifications
19805 we've already done, since unification is supposed to be done on
19806 an argument-by-argument basis. In other words, consider the
19807 following pathological case:
19809 template <int I, int J, int K>
19810 struct S {};
19812 template <int I, int J>
19813 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19815 template <int I, int J, int K>
19816 void f(S<I, J, K>, S<I, I, I>);
19818 void g() {
19819 S<0, 0, 0> s0;
19820 S<0, 1, 2> s2;
19822 f(s0, s2);
19823 }
19825 Now, by the time we consider the unification involving `s2', we
19826 already know that we must have `f<0, 0, 0>'. But, even though
19827 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19828 because there are two ways to unify base classes of S<0, 1, 2>
19829 with S<I, I, I>. If we kept the already deduced knowledge, we
19830 would reject the possibility I=1. */
19834 {
19838 }
19840 /* If unification failed, we're done. */
19846 }
19848 /* Given a template type PARM and a class type ARG, find the unique
19849 base type in ARG that is an instance of PARM. We do not examine
19850 ARG itself; only its base-classes. If there is not exactly one
19851 appropriate base class, return NULL_TREE. PARM may be the type of
19852 a partial specialization, as well as a plain template type. Used
19853 by unify. */
19855 static enum template_base_result
19858 {
19860 tree binfo;
19866 {
19867 /* The type could not be completed. */
19870 }
19872 /* Walk in inheritance graph order. The search order is not
19873 important, and this avoids multiple walks of virtual bases. */
19875 {
19880 {
19881 /* If there is more than one satisfactory baseclass, then:
19883 [temp.deduct.call]
19885 If they yield more than one possible deduced A, the type
19886 deduction fails.
19888 applies. */
19890 {
19893 }
19896 }
19897 }
19901 }
19903 /* Returns the level of DECL, which declares a template parameter. */
19905 static int
19907 {
19909 {
19919 }
19921 }
19923 /* Decide whether ARG can be unified with PARM, considering only the
19924 cv-qualifiers of each type, given STRICT as documented for unify.
19925 Returns nonzero iff the unification is OK on that basis. */
19927 static int
19929 {
19935 {
19936 /* Although a CVR qualifier is ignored when being applied to a
19937 substituted template parameter ([8.3.2]/1 for example), that
19938 does not allow us to unify "const T" with "int&" because both
19939 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19940 It is ok when we're allowing additional CV qualifiers
19941 at the outer level [14.8.2.1]/3,1st bullet. */
19951 }
19962 }
19964 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19965 void
19967 {
19971 {
19974 }
19975 else
19976 {
19979 }
19980 }
19982 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19983 do { \
19984 if (unify (TP, TA, P, A, S, EP)) \
19985 return 1; \
19986 } while (0)
19988 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19989 expansion at the end of PACKED_PARMS. Returns 0 if the type
19990 deduction succeeds, 1 otherwise. STRICT is the same as in
19991 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
19992 function call argument list. We'll need to adjust the arguments to make them
19993 types. SUBR tells us if this is from a recursive call to
19994 type_unification_real, or for comparing two template argument
19995 lists. */
19997 static int
20001 {
20002 tree parm
20012 /* Determine the parameter packs we will be deducing from the
20013 pattern, and record their current deductions. */
20016 {
20020 /* Determine the index and level of this parameter pack. */
20023 /* Keep track of the parameter packs and their corresponding
20024 argument packs. */
20027 }
20029 /* Loop through all of the arguments that have not yet been
20030 unified and unify each with the pattern. */
20032 {
20033 tree parm;
20037 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20038 or the element of its argument pack at the current index if
20039 this argument was explicitly specified. */
20041 {
20050 {
20053 }
20055 }
20057 /* If we had explicit template arguments, substitute them into the
20058 pattern before deduction. */
20060 {
20061 /* Some arguments might still be unspecified or dependent. */
20069 NULL_TREE);
20074 }
20075 else
20078 /* Unify the pattern with the current argument. */
20080 explain_p))
20083 /* For each parameter pack, collect the deduced value. */
20085 {
20091 }
20092 }
20094 /* Verify that the results of unification with the parameter packs
20095 produce results consistent with what we've seen before, and make
20096 the deduced argument packs available. */
20098 {
20105 /* By default keep the original deduced argument pack.
20106 If necessary, more specific code is going to update the
20107 resulting deduced argument later down in this function. */
20111 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20112 actually deduce anything. */
20120 {
20121 /* If we had fewer function args than explicit template args,
20122 just use the explicits. */
20127 }
20130 {
20131 tree result;
20132 /* Build the deduced *_ARGUMENT_PACK. */
20134 {
20137 }
20138 else
20143 /* Note the deduced argument packs for this parameter
20144 pack. */
20146 }
20150 {
20151 /* We only had the explicitly-provided arguments before, but
20152 now we have a complete set of arguments. */
20158 }
20159 else
20160 {
20166 /* Inconsistent unification of this parameter pack. */
20168 bad_old_arg,
20169 bad_new_arg);
20170 }
20171 }
20174 }
20176 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20177 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20178 parameters and return value are as for unify. */
20180 static int
20184 {
20185 tree parm_max;
20186 tree arg_max;
20190 /* Our representation of array types uses "N - 1" as the
20191 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20192 not an integer constant. We cannot unify arbitrarily
20193 complex expressions, so we eliminate the MINUS_EXPRs
20194 here. */
20198 {
20201 }
20205 {
20206 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20207 trying to unify the type of a variable with the type
20208 of a template parameter. For example:
20210 template <unsigned int N>
20211 void f (char (&) [N]);
20212 int g();
20213 void h(int i) {
20214 char a[g(i)];
20215 f(a);
20216 }
20218 Here, the type of the ARG will be "int [g(i)]", and
20219 may be a SAVE_EXPR, etc. */
20223 }
20225 /* If only one of the bounds used a MINUS_EXPR, compensate
20226 by adding one to the other bound. */
20229 integer_type_node,
20230 parm_max,
20231 integer_one_node);
20234 integer_type_node,
20235 arg_max,
20236 integer_one_node);
20240 }
20242 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20246 static pa_kind_t
20248 {
20257 else
20259 }
20261 /* Deduce the value of template parameters. TPARMS is the (innermost)
20262 set of template parameters to a template. TARGS is the bindings
20263 for those template parameters, as determined thus far; TARGS may
20264 include template arguments for outer levels of template parameters
20265 as well. PARM is a parameter to a template function, or a
20266 subcomponent of that parameter; ARG is the corresponding argument.
20267 This function attempts to match PARM with ARG in a manner
20268 consistent with the existing assignments in TARGS. If more values
20269 are deduced, then TARGS is updated.
20271 Returns 0 if the type deduction succeeds, 1 otherwise. The
20272 parameter STRICT is a bitwise or of the following flags:
20274 UNIFY_ALLOW_NONE:
20275 Require an exact match between PARM and ARG.
20276 UNIFY_ALLOW_MORE_CV_QUAL:
20277 Allow the deduced ARG to be more cv-qualified (by qualification
20278 conversion) than ARG.
20279 UNIFY_ALLOW_LESS_CV_QUAL:
20280 Allow the deduced ARG to be less cv-qualified than ARG.
20281 UNIFY_ALLOW_DERIVED:
20282 Allow the deduced ARG to be a template base class of ARG,
20283 or a pointer to a template base class of the type pointed to by
20284 ARG.
20285 UNIFY_ALLOW_INTEGER:
20286 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20287 case for more information.
20288 UNIFY_ALLOW_OUTER_LEVEL:
20289 This is the outermost level of a deduction. Used to determine validity
20290 of qualification conversions. A valid qualification conversion must
20291 have const qualified pointers leading up to the inner type which
20292 requires additional CV quals, except at the outer level, where const
20293 is not required [conv.qual]. It would be normal to set this flag in
20294 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20295 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20296 This is the outermost level of a deduction, and PARM can be more CV
20297 qualified at this point.
20298 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20299 This is the outermost level of a deduction, and PARM can be less CV
20300 qualified at this point. */
20302 static int
20305 {
20307 tree targ;
20308 tree tparm;
20310 tsubst_flags_t complain = (explain_p
20311 ? tf_warning_or_error
20314 /* I don't think this will do the right thing with respect to types.
20315 But the only case I've seen it in so far has been array bounds, where
20316 signedness is the only information lost, and I think that will be
20317 okay. */
20325 /* We can't deduce anything from this, but we might get all the
20326 template args from other function args. */
20332 /* If PARM uses template parameters, then we can't bail out here,
20333 even if ARG == PARM, since we won't record unifications for the
20334 template parameters. We might need them if we're trying to
20335 figure out which of two things is more specialized. */
20339 /* Handle init lists early, so the rest of the function can assume
20340 we're dealing with a type. */
20342 {
20347 /* Replace T with std::initializer_list<T> for deduction. */
20354 /* We can only deduce from an initializer list argument if the
20355 parameter is std::initializer_list or an array; otherwise this
20356 is a non-deduced context. */
20361 else
20362 {
20364 /* Deduction is defined in terms of a single type, so just punt
20365 on the (bizarre) std::initializer_list<T...>. */
20368 }
20371 {
20378 {
20382 /* It should only be possible to get here for a call. */
20384 elt_strict |= maybe_adjust_types_for_deduction
20387 }
20390 explain_p);
20391 }
20395 {
20396 /* Also deduce from the length of the initializer list. */
20403 }
20405 /* If the std::initializer_list<T> deduction worked, replace the
20406 deduced A with std::initializer_list<A>. */
20408 {
20413 }
20415 }
20417 /* If parm and arg aren't the same kind of thing (template, type, or
20418 expression), fail early. */
20422 /* Immediately reject some pairs that won't unify because of
20423 cv-qualification mismatches. */
20426 /* It is the elements of the array which hold the cv quals of an array
20427 type, and the elements might be template type parms. We'll check
20428 when we recurse. */
20430 /* We check the cv-qualifiers when unifying with template type
20431 parameters below. We want to allow ARG `const T' to unify with
20432 PARM `T' for example, when computing which of two templates
20433 is more specialized, for example. */
20447 {
20451 /* In a type which contains a nested-name-specifier, template
20452 argument values cannot be deduced for template parameters used
20453 within the nested-name-specifier. */
20465 /* The PARM is not one we're trying to unify. Just check
20466 to see if it matches ARG. */
20467 {
20472 else
20474 }
20481 /* Check for mixed types and values. */
20489 {
20492 {
20493 /* First try to match ARG directly. */
20495 explain_p);
20497 {
20498 /* Otherwise, look for a suitable base of ARG, as below. */
20505 }
20506 }
20507 /* ARG must be constructed from a template class or a template
20508 template parameter. */
20513 /* Deduce arguments T, i from TT<T> or TT<i>. */
20519 /* Fall through to deduce template name. */
20520 }
20524 {
20525 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20527 /* Simple cases: Value already set, does match or doesn't. */
20532 }
20533 else
20534 {
20535 /* If PARM is `const T' and ARG is only `int', we don't have
20536 a match unless we are allowing additional qualification.
20537 If ARG is `const int' and PARM is just `T' that's OK;
20538 that binds `const int' to `T'. */
20543 /* Consider the case where ARG is `const volatile int' and
20544 PARM is `const T'. Then, T should be `volatile int'. */
20545 arg = cp_build_qualified_type_real
20550 /* Simple cases: Value already set, does match or doesn't. */
20556 /* Make sure that ARG is not a variable-sized array. (Note
20557 that were talking about variable-sized arrays (like
20558 `int[n]'), rather than arrays of unknown size (like
20559 `int[]').) We'll get very confused by such a type since
20560 the bound of the array is not constant, and therefore
20561 not mangleable. Besides, such types are not allowed in
20562 ISO C++, so we can do as we please here. We do allow
20563 them for 'auto' deduction, since that isn't ABI-exposed. */
20567 /* Strip typedefs as in convert_template_argument. */
20569 }
20571 /* If ARG is a parameter pack or an expansion, we cannot unify
20572 against it unless PARM is also a parameter pack. */
20577 /* If the argument deduction results is a METHOD_TYPE,
20578 then there is a problem.
20579 METHOD_TYPE doesn't map to any real C++ type the result of
20580 the deduction can not be of that type. */
20594 {
20595 /* The PARM is not one we're trying to unify. Just check
20596 to see if it matches ARG. */
20602 }
20608 {
20613 }
20616 /* We deduce from array bounds in try_array_deduction. */
20620 {
20625 }
20627 /* [temp.deduct.type] If, in the declaration of a function template
20628 with a non-type template-parameter, the non-type
20629 template-parameter is used in an expression in the function
20630 parameter-list and, if the corresponding template-argument is
20631 deduced, the template-argument type shall match the type of the
20632 template-parameter exactly, except that a template-argument
20633 deduced from an array bound may be of any integral type.
20634 The non-type parameter might use already deduced type parameters. */
20637 {
20641 }
20644 /* Template-parameter dependent expression. Just accept it for now.
20645 It will later be processed in convert_template_argument. */
20646 ;
20651 /* Convert the ARG to the type of PARM; the deduced non-type
20652 template argument must exactly match the types of the
20653 corresponding parameter. */
20656 /* We haven't deduced the type of this parameter yet. Try again
20657 later. */
20659 else
20662 /* If ARG is a parameter pack or an expansion, we cannot unify
20663 against it unless PARM is also a parameter pack. */
20668 {
20671 }
20676 {
20677 /* A pointer-to-member constant can be unified only with
20678 another constant. */
20682 /* Just unify the class member. It would be useless (and possibly
20683 wrong, depending on the strict flags) to unify also
20684 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20685 arg refer to the same variable, even if through different
20686 classes. For instance:
20688 struct A { int x; };
20689 struct B : A { };
20691 Unification of &A::x and &B::x must succeed. */
20694 }
20697 {
20701 /* [temp.deduct.call]
20703 A can be another pointer or pointer to member type that can
20704 be converted to the deduced A via a qualification
20705 conversion (_conv.qual_).
20707 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20708 This will allow for additional cv-qualification of the
20709 pointed-to types if appropriate. */
20712 /* The derived-to-base conversion only persists through one
20713 level of pointers. */
20718 }
20750 /* We have already checked cv-qualification at the top of the
20751 function. */
20755 /* As far as unification is concerned, this wins. Later checks
20756 will invalidate it if necessary. */
20759 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20760 /* Type INTEGER_CST can come from ordinary constant template args. */
20772 {
20782 /* Check for pack expansions in the parameters. */
20784 {
20786 {
20788 /* We can unify against something with a trailing
20789 parameter pack. */
20791 else
20792 /* [temp.deduct.type]/9: If the template argument list of
20793 P contains a pack expansion that is not the last
20794 template argument, the entire template argument list
20795 is a non-deduced context. */
20797 }
20798 }
20800 /* If we don't have enough arguments to satisfy the parameters
20801 (not counting the pack expression at the end), or we have
20802 too many arguments for a parameter list that doesn't end in
20803 a pack expression, we can't unify. */
20809 /* Unify all of the parameters that precede the (optional)
20810 pack expression. */
20812 {
20817 }
20820 DEDUCE_EXACT,
20823 }
20831 {
20839 }
20844 {
20848 {
20849 /* First, we try to unify the PARM and ARG directly. */
20854 {
20855 /* Fallback to the special case allowed in
20856 [temp.deduct.call]:
20858 If P is a class, and P has the form
20859 template-id, then A can be a derived class of
20860 the deduced A. Likewise, if P is a pointer to
20861 a class of the form template-id, A can be a
20862 pointer to a derived class pointed to by the
20863 deduced A. */
20869 {
20870 /* Don't give the derived diagnostic if we're
20871 already dealing with the same template. */
20872 bool same_template
20878 }
20879 }
20880 }
20884 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20885 Then, we should unify `int' and `U'. */
20887 else
20888 /* There's no chance of unification succeeding. */
20893 }
20900 {
20903 tree a;
20909 /* CV qualifications for methods can never be deduced, they must
20910 match exactly. We need to check them explicitly here,
20911 because type_unification_real treats them as any other
20912 cv-qualified parameter. */
20914 && (!check_cv_quals_for_unify
20942 {
20954 }
20957 }
20960 /* Unify a pointer to member with a pointer to member function, which
20961 deduces the type of the member as a function type. */
20963 {
20964 /* Check top-level cv qualifiers */
20972 /* Determine the type of the function we are unifying against. */
20976 }
20995 /* Matched cases are handled by the ARG == PARM test above. */
20999 /* We might get a variable as a non-type template argument in parm if the
21000 corresponding parameter is type-dependent. Make any necessary
21001 adjustments based on whether arg is a reference. */
21005 {
21010 }
21011 /* Now use the normal expression code to check whether they match. */
21022 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21023 or UNDERLYING_TYPE nodes. */
21027 /* Unification fails if we hit an error node. */
21032 {
21042 }
21043 /* FALLTHRU */
21046 /* An unresolved overload is a nondeduced context. */
21050 expr:
21051 /* We must be looking at an expression. This can happen with
21052 something like:
21054 template <int I>
21055 void foo(S<I>, S<I + 2>);
21057 This is a "nondeduced context":
21059 [deduct.type]
21061 The nondeduced contexts are:
21063 --A type that is a template-id in which one or more of
21064 the template-arguments is an expression that references
21065 a template-parameter.
21067 In these cases, we assume deduction succeeded, but don't
21068 actually infer any unifications. */
21073 else
21075 }
21076 }
21077 #undef RECUR_AND_CHECK_FAILURE
21078 \f
21079 /* Note that DECL can be defined in this translation unit, if
21080 required. */
21082 static void
21084 {
21085 tree clone;
21089 }
21091 /* Called if RESULT is explicitly instantiated, or is a member of an
21092 explicitly instantiated class. */
21094 void
21096 {
21099 /* If this entity has already been written out, it's too late to
21100 make any modifications. */
21104 /* For anonymous namespace we don't need to do anything. */
21106 {
21109 }
21112 /* The TREE_PUBLIC flag for function declarations will have been
21113 set correctly by tsubst. */
21116 /* This might have been set by an earlier implicit instantiation. */
21121 else
21122 {
21125 /* Always make artificials weak. */
21128 /* For WIN32 we also want to put explicit instantiations in
21129 linkonce sections. */
21132 }
21134 /* If EXTERN_P, then this function will not be emitted -- unless
21135 followed by an explicit instantiation, at which point its linkage
21136 will be adjusted. If !EXTERN_P, then this function will be
21137 emitted here. In neither circumstance do we want
21138 import_export_decl to adjust the linkage. */
21140 }
21142 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21143 important template arguments. If any are missing, we check whether
21144 they're important by using error_mark_node for substituting into any
21145 args that were used for partial ordering (the ones between ARGS and END)
21146 and seeing if it bubbles up. */
21148 static bool
21150 {
21155 {
21158 }
21160 {
21164 }
21166 }
21168 /* Given two function templates PAT1 and PAT2, return:
21170 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21171 -1 if PAT2 is more specialized than PAT1.
21172 0 if neither is more specialized.
21174 LEN indicates the number of parameters we should consider
21175 (defaulted parameters should not be considered).
21177 The 1998 std underspecified function template partial ordering, and
21178 DR214 addresses the issue. We take pairs of arguments, one from
21179 each of the templates, and deduce them against each other. One of
21180 the templates will be more specialized if all the *other*
21181 template's arguments deduce against its arguments and at least one
21182 of its arguments *does* *not* deduce against the other template's
21183 corresponding argument. Deduction is done as for class templates.
21184 The arguments used in deduction have reference and top level cv
21185 qualifiers removed. Iff both arguments were originally reference
21186 types *and* deduction succeeds in both directions, an lvalue reference
21187 wins against an rvalue reference and otherwise the template
21188 with the more cv-qualified argument wins for that pairing (if
21189 neither is more cv-qualified, they both are equal). Unlike regular
21190 deduction, after all the arguments have been deduced in this way,
21191 we do *not* verify the deduced template argument values can be
21192 substituted into non-deduced contexts.
21194 The logic can be a bit confusing here, because we look at deduce1 and
21195 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21196 can find template arguments for pat1 to make arg1 look like arg2, that
21197 means that arg2 is at least as specialized as arg1. */
21199 int
21201 {
21214 /* Remove the this parameter from non-static member functions. If
21215 one is a non-static member function and the other is not a static
21216 member function, remove the first parameter from that function
21217 also. This situation occurs for operator functions where we
21218 locate both a member function (with this pointer) and non-member
21219 operator (with explicit first operand). */
21221 {
21226 }
21228 {
21231 {
21232 len--;
21234 }
21235 }
21237 /* If only one is a conversion operator, they are unordered. */
21241 /* Consider the return type for a conversion function */
21243 {
21246 len++;
21247 }
21249 processing_template_decl++;
21255 /* Stop when an ellipsis is seen. */
21257 {
21268 {
21269 /* When both arguments are pack expansions, we need only
21270 unify the patterns themselves. */
21274 /* This is the last comparison we need to do. */
21276 }
21278 /* DR 1847: If a particular P contains no template-parameters that
21279 participate in template argument deduction, that P is not used to
21280 determine the ordering. */
21286 {
21290 }
21293 {
21297 }
21303 {
21309 /* Setup the parameter vector, which contains only ARG1. */
21312 /* Setup the argument vector, which contains the remaining
21313 arguments. */
21322 /* We cannot deduce in the other direction, because ARG1 is
21323 a pack expansion but ARG2 is not. */
21325 }
21327 {
21333 /* Setup the parameter vector, which contains only ARG1. */
21336 /* Setup the argument vector, which contains the remaining
21337 arguments. */
21346 /* We cannot deduce in the other direction, because ARG2 is
21347 a pack expansion but ARG1 is not.*/
21349 }
21351 else
21352 {
21353 /* The normal case, where neither argument is a pack
21354 expansion. */
21361 }
21363 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21364 arg2, then arg2 is not as specialized as arg1. */
21370 /* "If, for a given type, deduction succeeds in both directions
21371 (i.e., the types are identical after the transformations above)
21372 and both P and A were reference types (before being replaced with
21373 the type referred to above):
21374 - if the type from the argument template was an lvalue reference and
21375 the type from the parameter template was not, the argument type is
21376 considered to be more specialized than the other; otherwise,
21377 - if the type from the argument template is more cv-qualified
21378 than the type from the parameter template (as described above),
21379 the argument type is considered to be more specialized than the other;
21380 otherwise,
21381 - neither type is more specialized than the other." */
21384 {
21386 {
21389 else
21391 }
21393 {
21398 }
21399 }
21402 /* We've failed to deduce something in either direction.
21403 These must be unordered. */
21406 next:
21410 /* We have already processed all of the arguments in our
21411 handing of the pack expansion type. */
21416 }
21418 /* "In most cases, all template parameters must have values in order for
21419 deduction to succeed, but for partial ordering purposes a template
21420 parameter may remain without a value provided it is not used in the
21421 types being used for partial ordering."
21423 Thus, if we are missing any of the targs1 we need to substitute into
21424 origs1, then pat2 is not as specialized as pat1. This can happen when
21425 there is a nondeduced context. */
21431 processing_template_decl--;
21433 /* If both deductions succeed, the partial ordering selects the more
21434 constrained template. */
21436 {
21441 }
21443 /* All things being equal, if the next argument is a pack expansion
21444 for one function but not for the other, prefer the
21445 non-variadic function. FIXME this is bogus; see c++/41958. */
21449 {
21452 }
21458 else
21460 }
21462 /* Determine which of two partial specializations of TMPL is more
21463 specialized.
21465 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21466 to the first partial specialization. The TREE_PURPOSE is the
21467 innermost set of template parameters for the partial
21468 specialization. PAT2 is similar, but for the second template.
21470 Return 1 if the first partial specialization is more specialized;
21471 -1 if the second is more specialized; 0 if neither is more
21472 specialized.
21474 See [temp.class.order] for information about determining which of
21475 two templates is more specialized. */
21477 static int
21479 {
21480 tree targs;
21489 /* Just like what happens for functions, if we are ordering between
21490 different template specializations, we may encounter dependent
21491 types in the arguments, and we need our dependency check functions
21492 to behave correctly. */
21496 {
21499 }
21503 {
21506 }
21509 /* If both deductions succeed, the partial ordering selects the more
21510 constrained template. */
21514 /* In the case of a tie where at least one of the templates
21515 has a parameter pack at the end, the template with the most
21516 non-packed parameters wins. */
21518 && any_deductions
21521 {
21527 /* We don't count the pack expansion at the end. */
21537 }
21540 }
21542 /* Return the template arguments that will produce the function signature
21543 DECL from the function template FN, with the explicit template
21544 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21545 also match. Return NULL_TREE if no satisfactory arguments could be
21546 found. */
21548 static tree
21550 {
21554 tree decl_arg_types;
21557 tree arg;
21561 /* Never do unification on the 'this' parameter. */
21582 }
21584 /* Return the innermost template arguments that, when applied to a partial
21585 specialization SPEC_TMPL of TMPL, yield the ARGS.
21587 For example, suppose we have:
21589 template <class T, class U> struct S {};
21590 template <class T> struct S<T*, int> {};
21592 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21593 partial specialization and the ARGS will be {double*, int}. The resulting
21594 vector will be {double}, indicating that `T' is bound to `double'. */
21596 static tree
21598 {
21600 tree spec_args
21603 tree deduced_args;
21604 tree innermost_deduced_args;
21608 {
21612 innermost_deduced_args);
21613 }
21614 else
21618 again:
21627 {
21629 {
21635 }
21637 }
21641 {
21644 }
21646 /* Verify that nondeduced template arguments agree with the type
21647 obtained from argument deduction.
21649 For example:
21651 struct A { typedef int X; };
21652 template <class T, class U> struct C {};
21653 template <class T> struct C<T, typename T::X> {};
21655 Then with the instantiation `C<A, int>', we can deduce that
21656 `T' is `A' but unify () does not check whether `typename T::X'
21657 is `int'. */
21666 /* We only need to check the innermost arguments; the other
21667 arguments will always agree. */
21672 /* Now that we have bindings for all of the template arguments,
21673 ensure that the arguments deduced for the template template
21674 parameters have compatible template parameter lists. See the use
21675 of template_template_parm_bindings_ok_p in fn_type_unification
21676 for more information. */
21681 }
21683 // Compare two function templates T1 and T2 by deducing bindings
21684 // from one against the other. If both deductions succeed, compare
21685 // constraints to see which is more constrained.
21686 static int
21688 {
21693 {
21696 }
21699 {
21702 }
21704 // If both deductions succeed, then one may be more constrained.
21709 }
21711 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21712 Return the TREE_LIST node with the most specialized template, if
21713 any. If there is no most specialized template, the error_mark_node
21714 is returned.
21716 Note that this function does not look at, or modify, the
21717 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21718 returned is one of the elements of INSTANTIATIONS, callers may
21719 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21720 and retrieve it from the value returned. */
21722 tree
21724 {
21731 {
21736 {
21737 /* Equally specialized, move to next function. If there
21738 is no next function, nothing's most specialized. */
21743 }
21744 }
21747 /* Now verify that champ is better than everything earlier in the
21748 instantiation list. */
21751 {
21754 }
21755 }
21757 processing_template_decl--;
21763 }
21765 /* If DECL is a specialization of some template, return the most
21766 general such template. Otherwise, returns NULL_TREE.
21768 For example, given:
21770 template <class T> struct S { template <class U> void f(U); };
21772 if TMPL is `template <class U> void S<int>::f(U)' this will return
21773 the full template. This function will not trace past partial
21774 specializations, however. For example, given in addition:
21776 template <class T> struct S<T*> { template <class U> void f(U); };
21778 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21779 `template <class T> template <class U> S<T*>::f(U)'. */
21781 tree
21783 {
21785 {
21788 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21789 template friend, or a FIELD_DECL for a capture pack. */
21792 }
21794 /* Look for more and more general templates. */
21796 {
21797 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21798 (See cp-tree.h for details.) */
21807 /* Stop if we run into an explicitly specialized class template. */
21814 }
21817 }
21819 /* Return the most specialized of the template partial specializations
21820 which can produce TARGET, a specialization of some class or variable
21821 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21822 a TEMPLATE_DECL node corresponding to the partial specialization, while
21823 the TREE_PURPOSE is the set of template arguments that must be
21824 substituted into the template pattern in order to generate TARGET.
21826 If the choice of partial specialization is ambiguous, a diagnostic
21827 is issued, and the error_mark_node is returned. If there are no
21828 partial specializations matching TARGET, then NULL_TREE is
21829 returned, indicating that the primary template should be used. */
21831 static tree
21833 {
21835 tree t;
21836 tree champ;
21843 {
21847 }
21849 {
21852 }
21854 {
21858 }
21859 else
21864 /* For determining which partial specialization to use, only the
21865 innermost args are interesting. */
21867 {
21870 }
21873 {
21874 tree spec_args;
21878 {
21879 /* Substitute in the template args from the enclosing class. */
21883 }
21890 {
21894 /* Keep the candidate only if the constraints are satisfied,
21895 or if we're not compiling with concepts. */
21898 {
21901 }
21902 }
21903 }
21913 {
21916 ;
21917 else
21918 {
21920 {
21923 {
21926 }
21927 }
21929 }
21930 }
21934 {
21937 {
21940 }
21941 }
21944 {
21951 else
21955 {
21960 }
21963 }
21966 }
21968 /* Explicitly instantiate DECL. */
21970 void
21972 {
21977 /* An error occurred, for which grokdeclarator has already issued
21978 an appropriate message. */
21981 {
21984 }
21990 {
21991 /* There is an asymmetry here in the way VAR_DECLs and
21992 FUNCTION_DECLs are handled by grokdeclarator. In the case of
21993 the latter, the DECL we get back will be marked as a
21994 template instantiation, and the appropriate
21995 DECL_TEMPLATE_INFO will be set up. This does not happen for
21996 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
21997 should handle VAR_DECLs as it currently handles
21998 FUNCTION_DECLs. */
22000 {
22003 }
22006 {
22009 }
22011 {
22016 }
22017 }
22019 {
22022 }
22023 else
22026 /* Check for various error cases. Note that if the explicit
22027 instantiation is valid the RESULT will currently be marked as an
22028 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22029 until we get here. */
22032 {
22033 /* DR 259 [temp.spec].
22035 Both an explicit instantiation and a declaration of an explicit
22036 specialization shall not appear in a program unless the explicit
22037 instantiation follows a declaration of the explicit specialization.
22039 For a given set of template parameters, if an explicit
22040 instantiation of a template appears after a declaration of an
22041 explicit specialization for that template, the explicit
22042 instantiation has no effect. */
22044 }
22046 {
22047 /* [temp.spec]
22049 No program shall explicitly instantiate any template more
22050 than once.
22052 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22053 the first instantiation was `extern' and the second is not,
22054 and EXTERN_P for the opposite case. */
22057 /* If an "extern" explicit instantiation follows an ordinary
22058 explicit instantiation, the template is instantiated. */
22061 }
22063 {
22066 }
22068 {
22071 }
22074 ;
22076 {
22079 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22082 }
22083 else
22091 }
22093 static void
22095 {
22101 {
22104 }
22105 }
22107 /* Called from do_type_instantiation through binding_table_foreach to
22108 do recursive instantiation for the type bound in ENTRY. */
22109 static void
22111 {
22117 }
22119 /* Called from do_type_instantiation to instantiate a member
22120 (a member function or a static member variable) of an
22121 explicitly instantiated class template. */
22122 static void
22124 {
22129 }
22131 /* Perform an explicit instantiation of template class T. STORAGE, if
22132 non-null, is the RID for extern, inline or static. COMPLAIN is
22133 nonzero if this is called from the parser, zero if called recursively,
22134 since the standard is unclear (as detailed below). */
22136 void
22138 {
22148 {
22149 tree tmpl =
22153 else
22156 }
22161 {
22164 t);
22166 }
22169 {
22171 {
22173 {
22176 "ISO C++ 1998 forbids the use of %<extern%> on "
22178 }
22179 else
22181 "ISO C++ forbids the use of %qE"
22183 }
22191 else
22192 {
22194 storage);
22196 }
22197 }
22200 {
22201 /* DR 259 [temp.spec].
22203 Both an explicit instantiation and a declaration of an explicit
22204 specialization shall not appear in a program unless the explicit
22205 instantiation follows a declaration of the explicit specialization.
22207 For a given set of template parameters, if an explicit
22208 instantiation of a template appears after a declaration of an
22209 explicit specialization for that template, the explicit
22210 instantiation has no effect. */
22212 }
22214 {
22215 /* [temp.spec]
22217 No program shall explicitly instantiate any template more
22218 than once.
22220 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22221 instantiation was `extern'. If EXTERN_P then the second is.
22222 These cases are OK. */
22229 /* If we've already instantiated the template, just return now. */
22232 }
22240 {
22241 tree tmp;
22243 /* In contrast to implicit instantiation, where only the
22244 declarations, and not the definitions, of members are
22245 instantiated, we have here:
22247 [temp.explicit]
22249 The explicit instantiation of a class template specialization
22250 implies the instantiation of all of its members not
22251 previously explicitly specialized in the translation unit
22252 containing the explicit instantiation.
22254 Of course, we can't instantiate member template classes, since
22255 we don't have any arguments for them. Note that the standard
22256 is unclear on whether the instantiation of the members are
22257 *explicit* instantiations or not. However, the most natural
22258 interpretation is that it should be an explicit instantiation. */
22274 }
22275 }
22277 /* Given a function DECL, which is a specialization of TMPL, modify
22278 DECL to be a re-instantiation of TMPL with the same template
22279 arguments. TMPL should be the template into which tsubst'ing
22280 should occur for DECL, not the most general template.
22282 One reason for doing this is a scenario like this:
22284 template <class T>
22285 void f(const T&, int i);
22287 void g() { f(3, 7); }
22289 template <class T>
22290 void f(const T& t, const int i) { }
22292 Note that when the template is first instantiated, with
22293 instantiate_template, the resulting DECL will have no name for the
22294 first parameter, and the wrong type for the second. So, when we go
22295 to instantiate the DECL, we regenerate it. */
22297 static void
22299 {
22300 /* The arguments used to instantiate DECL, from the most general
22301 template. */
22302 tree code_pattern;
22306 /* Make sure that we can see identifiers, and compute access
22307 correctly. */
22311 {
22312 tree decl_parm;
22313 tree pattern_parm;
22314 tree specs;
22328 specs);
22330 /* Merge parameter declarations. */
22333 pattern_parm
22337 {
22338 tree parm_type;
22339 tree attributes;
22344 NULL_TREE);
22350 {
22353 }
22356 }
22357 /* Merge any parameters that match with the function parameter
22358 pack. */
22360 {
22362 tree expanded_types;
22363 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22364 the parameters in this function parameter pack. */
22369 {
22370 tree parm_type;
22371 tree attributes;
22374 /* Rename the parameter to include the index. */
22383 {
22386 }
22388 }
22389 }
22390 /* Merge additional specifiers from the CODE_PATTERN. */
22394 }
22396 {
22404 }
22405 else
22409 }
22411 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22412 substituted to get DECL. */
22414 tree
22416 {
22419 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22420 for the instantiation. This is not always the most general
22421 template. Consider, for example:
22423 template <class T>
22424 struct S { template <class U> void f();
22425 template <> void f<int>(); };
22427 and an instantiation of S<double>::f<int>. We want TD to be the
22428 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22430 more general template. */
22432 /* We must also deal with friend templates. Given:
22434 template <class T> struct S {
22435 template <class U> friend void f() {};
22436 };
22438 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22439 so far as the language is concerned, but that's still
22440 where we get the pattern for the instantiation from. On
22441 other hand, if the definition comes outside the class, say:
22443 template <class T> struct S {
22444 template <class U> friend void f();
22445 };
22446 template <class U> friend void f() {}
22448 we don't need to look any further. That's what the check for
22449 DECL_INITIAL is for. */
22453 {
22454 /* The present template, TD, should not be a definition. If it
22455 were a definition, we should be using it! Note that we
22456 cannot restructure the loop to just keep going until we find
22457 a template with a definition, since that might go too far if
22458 a specialization was declared, but not defined. */
22460 /* Fetch the more general template. */
22462 }
22465 }
22467 /* Returns true if we need to instantiate this template instance even if we
22468 know we aren't going to emit it. */
22470 bool
22472 {
22473 /* We always instantiate inline functions so that we can inline them. An
22474 explicit instantiation declaration prohibits implicit instantiation of
22475 non-inline functions. With high levels of optimization, we would
22476 normally inline non-inline functions -- but we're not allowed to do
22477 that for "extern template" functions. Therefore, we check
22478 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22482 /* And we need to instantiate static data members so that
22483 their initializers are available in integral constant
22484 expressions. */
22487 }
22489 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22490 instantiate it now, modifying TREE_TYPE (fn). */
22492 void
22494 {
22497 /* Don't instantiate a noexcept-specification from template context. */
22512 {
22516 {
22531 }
22532 else
22536 }
22539 {
22542 else
22544 }
22545 }
22547 /* Produce the definition of D, a _DECL generated from a template. If
22548 DEFER_OK is true, then we don't have to actually do the
22549 instantiation now; we just have to do it sometime. Normally it is
22550 an error if this is an explicit instantiation but D is undefined.
22551 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22552 instantiated class template. */
22554 tree
22556 {
22558 tree gen_args;
22559 tree args;
22560 tree td;
22561 tree code_pattern;
22562 tree spec;
22563 tree gen_tmpl;
22571 /* This function should only be used to instantiate templates for
22572 functions and static member variables. */
22575 /* A concept is never instantiated. */
22578 /* Variables are never deferred; if instantiation is required, they
22579 are instantiated right away. That allows for better code in the
22580 case that an expression refers to the value of the variable --
22581 if the variable has a constant value the referring expression can
22582 take advantage of that fact. */
22586 /* Don't instantiate cloned functions. Instead, instantiate the
22587 functions they cloned. */
22595 /* D has already been instantiated or explicitly specialized, so
22596 there's nothing for us to do here.
22598 It might seem reasonable to check whether or not D is an explicit
22599 instantiation, and, if so, stop here. But when an explicit
22600 instantiation is deferred until the end of the compilation,
22601 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22602 the instantiation. */
22605 /* Check to see whether we know that this template will be
22606 instantiated in some other file, as with "extern template"
22607 extension. */
22610 /* In general, we do not instantiate such templates. */
22618 /* We should already have the extra args. */
22621 /* And what's in the hash table should match D. */
22625 /* This needs to happen before any tsubsting. */
22631 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22632 for the instantiation. */
22637 {
22638 /* Look up an explicit specialization, if any. */
22642 {
22645 }
22646 }
22650 /* We should never be trying to instantiate a member of a class
22651 template or partial specialization. */
22656 /* In the case of a friend template whose definition is provided
22657 outside the class, we may have too many arguments. Drop the
22658 ones we don't need. The same is true for specializations. */
22659 args = get_innermost_template_args
22663 {
22669 }
22670 else
22671 {
22676 else
22678 }
22680 /* We may be in the middle of deferred access check. Disable it now. */
22683 /* Unless an explicit instantiation directive has already determined
22684 the linkage of D, remember that a definition is available for
22685 this entity. */
22695 /* If D is a member of an explicitly instantiated class template,
22696 and no definition is available, treat it like an implicit
22697 instantiation. */
22700 {
22701 /* Leave linkage flags alone on instantiations with anonymous
22702 visibility. */
22704 {
22707 }
22709 }
22711 /* Defer all other templates, unless we have been explicitly
22712 forbidden from doing so. */
22714 template. */
22715 ! pattern_defined
22716 /* If it's OK to postpone instantiation, do so. */
22717 || defer_ok
22718 /* If this is a static data member that will be defined
22719 elsewhere, we don't want to instantiate the entire data
22720 member, but we do want to instantiate the initializer so that
22721 we can substitute that elsewhere. */
22723 /* Handle here a deleted function too, avoid generating
22724 its body (c++/61080). */
22726 {
22727 /* The definition of the static data member is now required so
22728 we must substitute the initializer. */
22732 {
22733 tree ns;
22734 tree init;
22743 args,
22746 /* If instantiating the initializer involved instantiating this
22747 again, don't call cp_finish_decl twice. */
22749 {
22750 /* Make sure the initializer is still constant, in case of
22751 circular dependency (template/instantiate6.C). */
22752 const_init
22756 LOOKUP_ONLYCONVERTING);
22757 }
22761 }
22763 /* We restore the source position here because it's used by
22764 add_pending_template. */
22770 /* [temp.explicit]
22772 The definition of a non-exported function template, a
22773 non-exported member function template, or a non-exported
22774 member function or static data member of a class template
22775 shall be present in every translation unit in which it is
22776 explicitly instantiated. */
22780 /* If we're in unevaluated context, we just wanted to get the
22781 constant value; this isn't an odr use, so don't queue
22782 a full instantiation. */
22785 /* ??? Historically, we have instantiated inline functions, even
22786 when marked as "extern template". */
22790 }
22791 /* Tell the repository that D is available in this translation unit
22792 -- and see if it is supposed to be instantiated here. */
22794 {
22795 /* In a PCH file, despite the fact that the repository hasn't
22796 requested instantiation in the PCH it is still possible that
22797 an instantiation will be required in a file that includes the
22798 PCH. */
22801 /* Instantiate inline functions so that the inliner can do its
22802 job, even though we'll not be emitting a copy of this
22803 function. */
22806 }
22809 tree fn_context;
22820 else
22821 {
22825 }
22827 /* Mark D as instantiated so that recursive calls to
22828 instantiate_decl do not try to instantiate it again. */
22831 /* Regenerate the declaration in case the template has been modified
22832 by a subsequent redeclaration. */
22835 /* We already set the file and line above. Reset them now in case
22836 they changed as a result of calling regenerate_decl_from_template. */
22840 {
22841 tree init;
22844 /* Clear out DECL_RTL; whatever was there before may not be right
22845 since we've reset the type of the declaration. */
22849 /* The initializer is placed in DECL_INITIAL by
22850 regenerate_decl_from_template so we don't need to
22851 push/pop_access_scope again here. Pull it out so that
22852 cp_finish_decl can process it. */
22857 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22858 initializer. That function will defer actual emission until
22859 we have a chance to determine linkage. */
22862 /* Enter the scope of D so that access-checking works correctly. */
22875 }
22879 {
22881 tree tmpl_parm;
22882 tree spec_parm;
22886 /* Save away the current list, in case we are instantiating one
22887 template from within the body of another. */
22890 /* Set up the list of local specializations. */
22893 /* Set up context. */
22897 else
22898 {
22900 {
22901 /* When instantiating a lambda's templated function
22902 operator, we need to push the non-lambda class scope
22903 of the lambda itself so that the nested function
22904 stack is sufficiently correct to deal with this
22905 capture. */
22907 do
22912 }
22914 }
22916 /* Some typedefs referenced from within the template code need to be
22917 access checked at template instantiation time, i.e now. These
22918 types were added to the template at parsing time. Let's get those
22919 and perform the access checks then. */
22921 args);
22923 /* Create substitution entries for the parameters. */
22927 {
22931 }
22933 {
22935 {
22938 }
22939 else
22940 {
22941 /* Register the (value) argument pack as a specialization of
22942 TMPL_PARM, then move on. */
22945 }
22946 }
22949 /* Substitute into the body of the function. */
22953 else
22954 {
22959 /* Set the current input_location to the end of the function
22960 so that finish_function knows where we are. */
22961 input_location
22964 /* Remember if we saw an infinite loop in the template. */
22965 current_function_infinite_loop
22967 }
22969 /* We don't need the local specializations any more. */
22973 /* Finish the function. */
22977 else
22978 {
22981 }
22987 }
22989 /* We're not deferring instantiation any more. */
22994 else
23000 out:
23009 }
23011 /* Run through the list of templates that we wish we could
23012 instantiate, and instantiate any we can. RETRIES is the
23013 number of times we retry pending template instantiation. */
23015 void
23017 {
23021 /* Instantiating templates may trigger vtable generation. This in turn
23022 may require further template instantiations. We place a limit here
23023 to avoid infinite loop. */
23025 {
23029 "template instantiation depth exceeds maximum of %d"
23030 " instantiating %q+D, possibly from virtual table generation"
23034 /* Pretend that we defined it. */
23037 }
23039 do
23040 {
23045 {
23050 {
23051 tree fn;
23054 {
23058 fn;
23066 }
23069 }
23070 else
23071 {
23074 {
23075 instantiation
23081 }
23085 }
23088 /* If INSTANTIATION has been instantiated, then we don't
23089 need to consider it again in the future. */
23091 else
23092 {
23095 }
23098 }
23100 }
23104 }
23106 /* Substitute ARGVEC into T, which is a list of initializers for
23107 either base class or a non-static data member. The TREE_PURPOSEs
23108 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23109 instantiate_decl. */
23111 static tree
23113 {
23117 {
23118 tree decl;
23119 tree init;
23125 {
23126 tree expr;
23127 tree arg;
23129 /* Expand the base class expansion type into separate base
23130 classes. */
23132 tf_warning_or_error,
23133 NULL_TREE);
23137 /* We'll be building separate TREE_LISTs of arguments for
23138 each base. */
23144 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23145 expand each argument in the TREE_VALUE of t. */
23152 /* VOID_TYPE_NODE is used to indicate
23153 value-initialization. */
23154 {
23157 }
23158 else
23159 {
23160 /* Substitute parameter packs into each argument in the
23161 TREE_LIST. */
23164 {
23165 tree expanded_exprs;
23167 /* Expand the argument. */
23169 expanded_exprs
23171 tf_warning_or_error,
23172 NULL_TREE);
23176 /* Prepend each of the expanded expressions to the
23177 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23179 {
23184 }
23185 }
23188 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23189 since we built them backwards. */
23191 {
23194 }
23195 }
23196 }
23199 {
23201 {
23205 }
23206 else
23207 {
23208 tree tmp;
23223 /* If we had an initializer but it instantiated to nothing,
23224 value-initialize the object. This will only occur when
23225 the initializer was a pack expansion where the parameter
23226 packs used in that expansion were of length zero. */
23229 }
23232 {
23236 }
23237 }
23238 }
23240 }
23242 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23244 static void
23246 {
23251 else
23253 }
23255 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23256 is the instantiation (which should have been created with
23257 start_enum) and ARGS are the template arguments to use. */
23259 static void
23261 {
23262 tree e;
23268 {
23269 tree value;
23270 tree decl;
23273 /* Note that in a template enum, the TREE_VALUE is the
23274 CONST_DECL, not the corresponding INTEGER_CST. */
23279 /* Give this enumeration constant the correct access. */
23282 /* Actually build the enumerator itself. Here we're assuming that
23283 enumerators can't have dependent attributes. */
23286 }
23296 }
23298 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23299 its type -- but without substituting the innermost set of template
23300 arguments. So, innermost set of template parameters will appear in
23301 the type. */
23303 tree
23305 {
23306 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23308 }
23310 /* Return truthvalue if we're processing a template different from
23311 the last one involved in diagnostics. */
23312 bool
23314 {
23316 }
23318 /* Remember current template involved in diagnostics. */
23319 void
23321 {
23323 }
23327 {
23329 }
23331 /* Return TRUE if current_function_decl is being instantiated, false
23332 otherwise. */
23334 bool
23336 {
23339 }
23341 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23342 type. Return zero for ok, nonzero for disallowed. Issue error and
23343 warning messages under control of COMPLAIN. */
23345 static int
23347 {
23362 /* A bound template template parm could later be instantiated to have a valid
23363 nontype parm type via an alias template. */
23369 {
23372 else
23374 type);
23375 }
23377 }
23379 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23380 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23382 static bool
23384 {
23385 tree scope;
23387 /* [temp.dep.type]
23389 A type is dependent if it is:
23391 -- a template parameter. Template template parameters are types
23392 for us (since TYPE_P holds true for them) so we handle
23393 them here. */
23397 /* -- a qualified-id with a nested-name-specifier which contains a
23398 class-name that names a dependent type or whose unqualified-id
23399 names a dependent type. */
23403 /* An alias template specialization can be dependent even if the
23404 resulting type is not. */
23408 /* -- a cv-qualified type where the cv-unqualified type is
23409 dependent.
23410 No code is necessary for this bullet; the code below handles
23411 cv-qualified types, and we don't want to strip aliases with
23412 TYPE_MAIN_VARIANT because of DR 1558. */
23413 /* -- a compound type constructed from any dependent type. */
23423 {
23424 tree arg_type;
23429 arg_type;
23434 }
23435 /* -- an array type constructed from any dependent type or whose
23436 size is specified by a constant expression that is
23437 value-dependent.
23439 We checked for type- and value-dependence of the bounds in
23440 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23442 {
23447 }
23449 /* -- a template-id in which either the template name is a template
23450 parameter ... */
23453 /* ... or any of the template arguments is a dependent type or
23454 an expression that is type-dependent or value-dependent. */
23456 && (any_dependent_template_arguments_p
23460 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23461 dependent; if the argument of the `typeof' expression is not
23462 type-dependent, then it should already been have resolved. */
23468 /* A template argument pack is dependent if any of its packed
23469 arguments are. */
23471 {
23477 }
23479 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23480 be template parameters. */
23487 /* The standard does not specifically mention types that are local
23488 to template functions or local classes, but they should be
23489 considered dependent too. For example:
23491 template <int I> void f() {
23492 enum E { a = I };
23493 S<sizeof (E)> s;
23494 }
23496 The size of `E' cannot be known until the value of `I' has been
23497 determined. Therefore, `E' must be considered dependent. */
23501 /* Don't use type_dependent_expression_p here, as it can lead
23502 to infinite recursion trying to determine whether a lambda
23503 nested in a lambda is dependent (c++/47687). */
23507 && (any_dependent_template_arguments_p
23511 /* Other types are non-dependent. */
23513 }
23515 /* Returns TRUE if TYPE is dependent, in the sense of
23516 [temp.dep.type]. Note that a NULL type is considered dependent. */
23518 bool
23520 {
23521 /* If there are no template parameters in scope, then there can't be
23522 any dependent types. */
23524 {
23525 /* If we are not processing a template, then nobody should be
23526 providing us with a dependent type. */
23530 }
23532 /* If the type is NULL, we have not computed a type for the entity
23533 in question; in that case, the type is dependent. */
23537 /* Erroneous types can be considered non-dependent. */
23541 /* Getting here with global_type_node means we improperly called this
23542 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23545 /* If we have not already computed the appropriate value for TYPE,
23546 do so now. */
23548 {
23551 }
23554 }
23556 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23557 lookup. In other words, a dependent type that is not the current
23558 instantiation. */
23560 bool
23562 {
23565 }
23567 /* T is a SCOPE_REF; return whether we need to consider it
23568 instantiation-dependent so that we can check access at instantiation
23569 time even though we know which member it resolves to. */
23571 static bool
23573 {
23579 else
23581 }
23583 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23584 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23585 expression. */
23587 /* Note that this predicate is not appropriate for general expressions;
23588 only constant expressions (that satisfy potential_constant_expression)
23589 can be tested for value dependence. */
23591 bool
23593 {
23597 /* A name declared with a dependent type. */
23602 {
23604 /* A dependent member function of the current instantiation. */
23608 /* A dependent member function of the current instantiation. */
23615 /* A name that has not been looked up -- must be dependent. */
23619 /* A non-type template parm. */
23623 /* A non-type template parm. */
23629 /* A constant with literal type and is initialized
23630 with an expression that is value-dependent.
23632 Note that a non-dependent parenthesized initializer will have
23633 already been replaced with its constant value, so if we see
23634 a TREE_LIST it must be dependent. */
23638 /* cp_finish_decl doesn't fold reference initializers. */
23644 {
23648 }
23656 /* These expressions are value-dependent if the type to which
23657 the cast occurs is dependent or the expression being casted
23658 is value-dependent. */
23659 {
23665 /* A functional cast has a list of operands. */
23668 {
23669 /* If there are no operands, it must be an expression such
23670 as "int()". This should not happen for aggregate types
23671 because it would form non-constant expressions. */
23676 }
23682 }
23687 /* FALLTHRU */
23690 /* A `sizeof' expression is value-dependent if the operand is
23691 type-dependent or is a pack expansion. */
23700 /* An 'encode' expression is value-dependent if the operand is
23701 type-dependent. */
23710 /* All instantiation-dependent expressions should also be considered
23711 value-dependent. */
23719 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23720 is value-dependent. */
23721 {
23730 }
23733 {
23737 }
23748 {
23752 }
23755 /* Treat all requires-expressions as value-dependent so
23756 we don't try to fold them. */
23763 {
23770 {
23772 /* In a call to a constexpr member function, look through the
23773 implicit ADDR_EXPR on the object argument so that it doesn't
23774 cause the call to be considered value-dependent. We also
23775 look through it in potential_constant_expression. */
23782 }
23784 }
23787 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23788 type-dependent. */
23793 {
23795 tree val;
23802 }
23805 /* Treat a GNU statement expression as dependent to avoid crashing
23806 under instantiate_non_dependent_expr; it can't be constant. */
23810 /* A constant expression is value-dependent if any subexpression is
23811 value-dependent. */
23813 {
23820 {
23824 {
23827 /* In some cases, some of the operands may be missing.l
23828 (For example, in the case of PREDECREMENT_EXPR, the
23829 amount to increment by may be missing.) That doesn't
23830 make the expression dependent. */
23833 }
23834 }
23838 }
23840 }
23842 /* The expression is not value-dependent. */
23844 }
23846 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23847 [temp.dep.expr]. Note that an expression with no type is
23848 considered dependent. Other parts of the compiler arrange for an
23849 expression with type-dependent subexpressions to have no type, so
23850 this function doesn't have to be fully recursive. */
23852 bool
23854 {
23861 /* An unresolved name is always dependent. */
23867 /* A fold expression is type-dependent. */
23874 /* Some expression forms are never type-dependent. */
23888 /* The types of these expressions depends only on the type to which
23889 the cast occurs. */
23898 /* The types of these expressions depends only on the type created
23899 by the expression. */
23902 {
23903 /* For NEW_EXPR tree nodes created inside a template, either
23904 the object type itself or a TREE_LIST may appear as the
23905 operand 1. */
23908 /* This is an array type. We need to check array dimensions
23909 as well. */
23911 || value_dependent_expression_p
23913 else
23915 }
23918 {
23922 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23923 contains an identifier associated by name lookup with one or more
23924 declarations declared with a dependent type, or...a
23925 nested-name-specifier or qualified-id that names a member of an
23926 unknown specialization. */
23929 }
23939 {
23940 tree elt;
23944 {
23947 }
23949 }
23951 /* A static data member of the current instantiation with incomplete
23952 array type is type-dependent, as the definition and specializations
23953 can have different bounds. */
23960 /* An array of unknown bound depending on a variadic parameter, eg:
23962 template<typename... Args>
23963 void foo (Args... args)
23964 {
23965 int arr[] = { args... };
23966 }
23968 template<int... vals>
23969 void bar ()
23970 {
23971 int arr[] = { vals... };
23972 }
23974 If the array has no length and has an initializer, it must be that
23975 we couldn't determine its length in cp_complete_array_type because
23976 it is dependent. */
23984 /* A function or variable template-id is type-dependent if it has any
23985 dependent template arguments. Note that we only consider the innermost
23986 template arguments here, since those are the ones that come from the
23987 template-id; the template arguments for the enclosing class do not make it
23988 type-dependent, they only make a member function value-dependent. */
23993 && (any_dependent_template_arguments_p
23997 /* Always dependent, on the number of arguments if nothing else. */
24002 {
24007 {
24013 }
24014 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24019 {
24024 }
24027 {
24034 }
24044 }
24048 /* Dependent type attributes might not have made it from the decl to
24049 the type yet. */
24055 }
24057 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24058 type-dependent if the expression refers to a member of the current
24059 instantiation and the type of the referenced member is dependent, or the
24060 class member access expression refers to a member of an unknown
24061 specialization.
24063 This function returns true if the OBJECT in such a class member access
24064 expression is of an unknown specialization. */
24066 bool
24068 {
24069 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24070 dependent. */
24075 }
24077 /* walk_tree callback function for instantiation_dependent_expression_p,
24078 below. Returns non-zero if a dependent subexpression is found. */
24080 static tree
24083 {
24085 {
24086 /* We don't have to worry about decltype currently because decltype
24087 of an instantiation-dependent expr is a dependent type. This
24088 might change depending on the resolution of DR 1172. */
24091 }
24094 {
24095 /* Don't treat an argument list as dependent just because it has no
24096 TREE_TYPE. */
24104 /* Handle expressions with type operands. */
24109 {
24114 {
24117 else
24118 {
24121 }
24122 }
24124 }
24128 /* In a template, finish_class_member_access_expr creates a
24129 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24130 type-dependent, so that we can check access control at
24131 instantiation time (PR 42277). See also Core issue 1273. */
24138 else
24141 /* Treat statement-expressions as dependent. */
24145 /* Treat requires-expressions as dependent. */
24150 /* Treat calls to function concepts as dependent. */
24156 /* And variable concepts. */
24163 }
24167 else
24169 }
24171 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24172 sense defined by the ABI:
24174 "An expression is instantiation-dependent if it is type-dependent
24175 or value-dependent, or it has a subexpression that is type-dependent
24176 or value-dependent."
24178 Except don't actually check value-dependence for unevaluated expressions,
24179 because in sizeof(i) we don't care about the value of i. Checking
24180 type-dependence will in turn check value-dependence of array bounds/template
24181 arguments as needed. */
24183 bool
24185 {
24186 tree result;
24197 }
24199 /* As above, but also check value-dependence of the expression as a whole. */
24201 bool
24203 {
24206 }
24208 /* Like type_dependent_expression_p, but it also works while not processing
24209 a template definition, i.e. during substitution or mangling. */
24211 bool
24213 {
24219 }
24221 /* Returns TRUE if ARGS contains a type-dependent expression. */
24223 bool
24225 {
24227 tree arg;
24230 {
24233 }
24235 }
24237 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24238 expressions) contains any type-dependent expressions. */
24240 bool
24242 {
24248 }
24250 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24251 expressions) contains any value-dependent expressions. */
24253 bool
24255 {
24261 }
24263 /* Returns TRUE if the ARG (a template argument) is dependent. */
24265 bool
24267 {
24271 /* Assume a template argument that was wrongly written by the user
24272 is dependent. This is consistent with what
24273 any_dependent_template_arguments_p [that calls this function]
24274 does. */
24284 {
24287 /* A member template of a dependent class is not necessarily
24288 type-dependent, but it is a dependent template argument because it
24289 will be a member of an unknown specialization to that template. */
24292 }
24294 {
24298 {
24301 }
24304 }
24307 else
24310 }
24312 /* Returns true if ARGS (a collection of template arguments) contains
24313 any types that require structural equality testing. */
24315 bool
24317 {
24327 {
24330 {
24336 {
24337 /* Look inside the argument pack. */
24340 }
24343 {
24356 }
24357 }
24358 }
24361 }
24363 /* Returns true if ARGS (a collection of template arguments) contains
24364 any dependent arguments. */
24366 bool
24368 {
24378 {
24383 }
24386 }
24388 /* Returns TRUE if the template TMPL is type-dependent. */
24390 bool
24392 {
24394 {
24399 }
24401 /* Template template parameters are dependent. */
24405 /* So are names that have not been looked up. */
24409 }
24411 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24413 bool
24415 {
24418 }
24420 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24421 are dependent. */
24423 bool
24425 {
24432 {
24454 {
24458 }
24462 {
24466 {
24471 }
24472 }
24473 }
24476 }
24478 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24479 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24480 no such TYPE can be found. Note that this function peers inside
24481 uninstantiated templates and therefore should be used only in
24482 extremely limited situations. ONLY_CURRENT_P restricts this
24483 peering to the currently open classes hierarchy (which is required
24484 when comparing types). */
24486 tree
24488 {
24489 tree scope;
24490 tree name;
24491 tree decl;
24493 tree pushed_scope;
24494 tree result;
24499 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24500 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24501 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24502 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24503 identifier of the TYPENAME_TYPE anymore.
24504 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24505 TYPENAME_TYPE instead, we avoid messing up with a possible
24506 typedef variant case. */
24509 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24510 it first before we can figure out what NAME refers to. */
24512 {
24514 /* Given a class template A with a dependent base with nested type C,
24515 typedef typename A::C::C C will land us here, as trying to resolve
24516 the initial A::C leads to the local C typedef, which leads back to
24517 A::C::C. So we break the recursion now. */
24519 else
24521 }
24522 /* If we don't know what SCOPE refers to, then we cannot resolve the
24523 TYPENAME_TYPE. */
24526 /* If this is a typedef, we don't want to look inside (c++/11987). */
24529 /* If SCOPE isn't the template itself, it will not have a valid
24530 TYPE_FIELDS list. */
24532 /* scope is either the template itself or a compatible instantiation
24533 like X<T>, so look up the name in the original template. */
24535 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24537 /* If scope has no fields, it can't be a current instantiation. Check this
24538 before currently_open_class to avoid infinite recursion (71515). */
24541 /* If the SCOPE is not the current instantiation, there's no reason
24542 to look inside it. */
24545 /* Enter the SCOPE so that name lookup will be resolved as if we
24546 were in the class definition. In particular, SCOPE will no
24547 longer be considered a dependent type. */
24549 /* Look up the declaration. */
24551 tf_warning_or_error);
24555 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24556 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24561 {
24565 }
24568 {
24569 tree tmpl;
24570 tree args;
24571 /* Obtain the template and the arguments. */
24574 /* Instantiate the template. */
24580 }
24582 /* Leave the SCOPE. */
24586 /* If we failed to resolve it, return the original typename. */
24590 /* If lookup found a typename type, resolve that too. */
24592 {
24593 /* Ill-formed programs can cause infinite recursion here, so we
24594 must catch that. */
24598 }
24600 /* Qualify the resulting type. */
24606 }
24608 /* EXPR is an expression which is not type-dependent. Return a proxy
24609 for EXPR that can be used to compute the types of larger
24610 expressions containing EXPR. */
24612 tree
24614 {
24615 tree inner_expr;
24617 /* When checking, try to get a constant value for all non-dependent
24618 expressions in order to expose bugs in *_dependent_expression_p
24619 and constexpr. This can affect code generation, see PR70704, so
24620 only do this for -fchecking=2. */
24623 /* Don't do this during nsdmi parsing as it can lead to
24624 unexpected recursive instantiations. */
24626 /* Don't do this during concept expansion either and for
24627 the same reason. */
24631 /* Preserve OVERLOADs; the functions must be available to resolve
24632 types. */
24643 /* There is no need to return a proxy for a variable. */
24646 /* Preserve string constants; conversions from string constants to
24647 "char *" are allowed, even though normally a "const char *"
24648 cannot be used to initialize a "char *". */
24651 /* Preserve void and arithmetic constants, as an optimization -- there is no
24652 reason to create a new node. */
24657 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24658 There is at least one place where we want to know that a
24659 particular expression is a throw-expression: when checking a ?:
24660 expression, there are special rules if the second or third
24661 argument is a throw-expression. */
24665 /* Don't wrap an initializer list, we need to be able to look inside. */
24669 /* Don't wrap a dummy object, we need to be able to test for it. */
24688 /* If the type is unknown, it can't really be non-dependent */
24691 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24693 }
24695 /* ARGS is a vector of expressions as arguments to a function call.
24696 Replace the arguments with equivalent non-dependent expressions.
24697 This modifies ARGS in place. */
24699 void
24701 {
24703 tree arg;
24706 {
24710 }
24711 }
24713 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24714 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24715 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24717 static tree
24719 {
24733 }
24735 tree
24737 {
24739 }
24741 tree
24743 {
24745 }
24747 /* Return a C++17 deduction placeholder for class template TMPL. */
24749 tree
24751 {
24755 }
24757 /* Make a "constrained auto" type-specifier. This is an
24758 auto type with constraints that must be associated after
24759 deduction. The constraint is formed from the given
24760 CONC and its optional sequence of arguments, which are
24761 non-null if written as partial-concept-id. */
24763 tree
24765 {
24768 /* Build the constraint. */
24776 /* Our canonical type depends on the constraint. */
24779 /* Attach the constraint to the type declaration. */
24782 }
24784 /* Given type ARG, return std::initializer_list<ARG>. */
24786 static tree
24788 {
24790 tree argvec;
24792 {
24796 }
24801 }
24803 /* Replace auto in TYPE with std::initializer_list<auto>. */
24805 static tree
24807 {
24814 }
24816 /* Hash traits for hashing possibly constrained 'auto'
24817 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24820 {
24823 };
24825 /* Hash the 'auto' T. */
24827 inline hashval_t
24829 {
24831 /* Matching constrained-type-specifiers denote the same template
24832 parameter, so hash the constraint. */
24834 else
24835 /* But unconstrained autos are all separate, so just hash the pointer. */
24837 }
24839 /* Compare two 'auto's. */
24843 {
24850 /* Two unconstrained autos are distinct. */
24855 }
24857 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24858 constrained) auto, add it to the vector. */
24860 static int
24862 {
24865 {
24866 /* All the autos were built with index 0; fix that up now. */
24870 /* If this is a repeated constrained-type-specifier, use the index we
24871 chose before. */
24873 else
24874 {
24875 /* Otherwise this is new, so use the current count. */
24878 }
24880 }
24882 /* Always keep walking. */
24884 }
24886 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24887 says they can appear anywhere in the type. */
24889 static tree
24891 {
24900 {
24905 }
24908 }
24910 /* The stem for deduction guide names. */
24913 /* Return the name for a deduction guide for class template TMPL. */
24915 tree
24917 {
24928 }
24930 /* True if NAME is the name of a deduction guide. */
24932 bool
24934 {
24938 }
24940 /* True if FN is a deduction guide. */
24942 bool
24944 {
24949 }
24951 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24953 bool
24955 {
24962 }
24964 /* True if FN is a guide generated from a constructor template. */
24966 bool
24968 {
24973 {
24976 }
24978 }
24980 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
24981 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
24982 template parameter types. Note that the handling of template template
24983 parameters relies on current_template_parms being set appropriately for the
24984 new template. */
24986 static tree
24989 {
24992 tree newtype;
24995 {
25002 }
25003 else
25007 tree newdecl
25012 tree newidx;
25015 {
25025 {
25030 // First create a copy (ttargs) of tsubst_args with an
25031 // additional level for the template template parameter's own
25032 // template parameters (ttparms).
25033 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25041 // Substitute ttargs into ttparms to fix references to
25042 // other template parameters.
25044 complain);
25045 // Now substitute again with args based on tparms, to reduce
25046 // the level of the ttparms.
25049 complain);
25050 // Finally, tack the adjusted parms onto tparms.
25052 current_template_parms);
25054 }
25055 }
25056 else
25057 {
25059 tree newconst
25071 }
25074 }
25076 /* Returns a C++17 class deduction guide template based on the constructor
25077 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25078 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25080 static tree
25082 {
25086 location_t loc;
25089 {
25093 {
25096 }
25097 else
25107 }
25108 else
25109 {
25113 tree fn_tmpl;
25115 {
25118 }
25119 else
25123 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25124 fully specialized args for the enclosing class. Strip those off, as
25125 the deduction guide won't have those template parameters. */
25128 /* Discard the 'this' parameter. */
25136 {
25139 /* For a member template constructor, we need to flatten the two
25140 template parameter lists into one, and then adjust the function
25141 signature accordingly. This gets...complicated. */
25145 /* For a member template we should have two levels of parms/args, one
25146 for the class and one for the constructor. We stripped
25147 specialized args for further enclosing classes above. */
25151 /* Template args for translating references to the two-level template
25152 parameters into references to the one-level template parameters we
25153 are creating. */
25158 /* Template parms for the constructor template. */
25161 /* Template parms for the class template. */
25165 /* Template parms for the deduction guide start as a copy of the
25166 template parms for the class. We set current_template_parms for
25167 lookup_template_class_1. */
25173 /* Now we need to rewrite the constructor parms to append them to the
25174 class parms. */
25176 {
25191 }
25193 /* Now we have a final set of template parms to substitute into the
25194 function signature. */
25204 }
25205 }
25208 {
25209 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25213 }
25217 FUNCTION_DECL,
25234 }
25236 /* Deduce template arguments for the class template placeholder PTYPE for
25237 template TMPL based on the initializer INIT, and return the resulting
25238 type. */
25240 static tree
25242 tsubst_flags_t complain)
25243 {
25245 {
25246 /* We should have handled this in the caller. */
25252 }
25264 else
25275 /* Prune explicit deduction guides in copy-initialization context. */
25277 {
25283 {
25284 /* Found a nonconverting guide, prune the candidates. */
25291 }
25292 }
25297 {
25300 }
25304 // FIXME cache artificial deduction guides
25307 {
25312 else
25316 }
25319 {
25328 {
25333 else
25335 }
25336 }
25339 {
25341 " of %qT, as it has no non-explicit deduction guides or "
25344 }
25350 {
25356 }
25362 }
25364 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25365 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25367 tree
25369 {
25371 tf_warning_or_error,
25372 adc_unspecified);
25373 }
25375 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25376 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25377 The CONTEXT determines the context in which auto deduction is performed
25378 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25379 OUTER_TARGS are used during template argument deduction
25380 (context == adc_unify) to properly substitute the result, and is ignored
25381 in other contexts.
25383 For partial-concept-ids, extra args may be appended to the list of deduced
25384 template arguments prior to determining constraint satisfaction. */
25386 tree
25390 {
25391 tree targs;
25398 /* Defining a subset of type-dependent expressions that we can deduce
25399 from ahead of time isn't worth the trouble. */
25403 /* C++17 class template argument deduction. */
25407 /* Nothing we can do with this, even in deduction context. */
25410 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25411 with either a new invented type template parameter U or, if the
25412 initializer is a braced-init-list (8.5.4), with
25413 std::initializer_list<U>. */
25415 {
25420 else
25421 {
25423 {
25427 "for deduction to %<std::initializer_list%>, use copy-"
25429 }
25431 }
25432 }
25443 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25444 and initializer has array type, deduce cv-qualified array type. */
25446 complain);
25448 {
25457 {
25461 }
25462 }
25463 else
25464 {
25466 tree tparms;
25470 else
25471 {
25475 }
25482 {
25484 /* Try again at instantiation time. */
25488 /* If type is error_mark_node a diagnostic must have been
25489 emitted by now. Also, having a mention to '<type error>'
25490 in the diagnostic is not really useful to the user. */
25491 {
25495 else
25500 }
25502 }
25503 }
25505 /* Check any placeholder constraints against the deduced type. */
25508 {
25509 /* Use the deduced type to check the associated constraints. If we
25510 have a partial-concept-id, rebuild the argument list so that
25511 we check using the extra arguments. */
25515 {
25518 }
25519 else
25522 {
25524 {
25526 {
25544 }
25546 }
25548 }
25549 }
25555 }
25557 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25558 result. */
25560 tree
25562 {
25564 {
25570 /* In an abbreviated function template we didn't know we were dealing
25571 with a function template when we saw the auto return type, so update
25572 it to have the correct level. */
25574 }
25576 }
25578 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25579 'decltype(auto)' or a deduced class template. */
25581 bool
25583 {
25589 else
25591 }
25593 /* for_each_template_parm callback for type_uses_auto. */
25595 int
25597 {
25599 }
25601 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25602 a use of `auto'. Returns NULL_TREE otherwise. */
25604 tree
25606 {
25610 {
25611 /* The Concepts TS allows multiple autos in one type-specifier; just
25612 return the first one we find, do_auto_deduction will collect all of
25613 them. */
25617 else
25619 }
25620 else
25622 }
25624 /* For a given template T, return the vector of typedefs referenced
25625 in T for which access check is needed at T instantiation time.
25626 T is either a FUNCTION_DECL or a RECORD_TYPE.
25627 Those typedefs were added to T by the function
25628 append_type_to_template_for_access_check. */
25632 {
25633 tree ti;
25644 {
25649 }
25652 }
25654 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25655 tied to T. That list of typedefs will be access checked at
25656 T instantiation time.
25657 T is either a FUNCTION_DECL or a RECORD_TYPE.
25658 TYPE_DECL is a TYPE_DECL node representing a typedef.
25659 SCOPE is the scope through which TYPE_DECL is accessed.
25660 LOCATION is the location of the usage point of TYPE_DECL.
25662 This function is a subroutine of
25663 append_type_to_template_for_access_check. */
25665 static void
25667 tree type_decl,
25668 tree scope,
25669 location_t location)
25670 {
25671 qualified_typedef_usage_t typedef_usage;
25672 tree ti;
25679 && type_decl
25693 }
25695 /* Append TYPE_DECL to the template TEMPL.
25696 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25697 At TEMPL instanciation time, TYPE_DECL will be checked to see
25698 if it can be accessed through SCOPE.
25699 LOCATION is the location of the usage point of TYPE_DECL.
25701 e.g. consider the following code snippet:
25703 class C
25704 {
25705 typedef int myint;
25706 };
25708 template<class U> struct S
25709 {
25710 C::myint mi; // <-- usage point of the typedef C::myint
25711 };
25713 S<char> s;
25715 At S<char> instantiation time, we need to check the access of C::myint
25716 In other words, we need to check the access of the myint typedef through
25717 the C scope. For that purpose, this function will add the myint typedef
25718 and the scope C through which its being accessed to a list of typedefs
25719 tied to the template S. That list will be walked at template instantiation
25720 time and access check performed on each typedefs it contains.
25721 Note that this particular code snippet should yield an error because
25722 myint is private to C. */
25724 void
25726 tree type_decl,
25727 tree scope,
25728 location_t location)
25729 {
25735 /* Make sure we don't append the type to the template twice. */
25742 }
25744 /* Convert the generic type parameters in PARM that match the types given in the
25745 range [START_IDX, END_IDX) from the current_template_parms into generic type
25746 packs. */
25748 tree
25750 {
25761 {
25762 /* Create a distinct parameter pack type from the current parm and add it
25763 to the replacement args to tsubst below into the generic function
25764 parameter. */
25779 }
25785 /* If there are more levels then build up the replacement with the outer
25786 template parms. */
25790 replacement);
25793 }
25795 /* Entries in the decl_constraint hash table. */
25797 {
25798 tree decl;
25799 tree ci;
25800 };
25802 /* Hashing function and equality for constraint entries. */
25804 {
25806 {
25808 }
25811 {
25813 }
25814 };
25816 /* A mapping from declarations to constraint information. Note that
25817 both templates and their underlying declarations are mapped to the
25818 same constraint information.
25820 FIXME: This is defined in pt.c because garbage collection
25821 code is not being generated for constraint.cc. */
25825 /* Returns the template constraints of declaration T. If T is not
25826 constrained, return NULL_TREE. Note that T must be non-null. */
25828 tree
25830 {
25841 else
25843 }
25845 /* Associate the given constraint information CI with the declaration
25846 T. If T is a template, then the constraints are associated with
25847 its underlying declaration. Don't build associations if CI is
25848 NULL_TREE. */
25850 void
25852 {
25864 }
25866 /* Remove the associated constraints of the declaration T. */
25868 void
25870 {
25879 }
25881 /* Memoized satisfaction results for declarations. This
25882 maps the pair (constraint_info, arguments) to the result computed
25883 by constraints_satisfied_p. */
25886 {
25887 tree ci;
25888 tree args;
25889 tree result;
25890 };
25892 /* Hashing function and equality for constraint entries. */
25895 {
25897 {
25900 }
25903 {
25905 }
25906 };
25908 /* Memoized satisfaction results for concept checks. */
25911 {
25912 tree tmpl;
25913 tree args;
25914 tree result;
25915 };
25917 /* Hashing function and equality for constraint entries. */
25920 {
25922 {
25924 }
25927 {
25932 }
25933 };
25938 /* Search for a memoized satisfaction result. Returns one of the
25939 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25941 tree
25943 {
25948 else
25950 }
25952 /* Memoize the result of a satisfication test. Returns the saved result. */
25954 tree
25956 {
25963 }
25965 /* Search for a memoized satisfaction result for a concept. */
25967 tree
25969 {
25974 else
25976 }
25978 /* Memoize the result of a concept check. Returns the saved result. */
25980 tree
25982 {
25989 }
25993 /* Returns a prior concept specialization. This returns the substituted
25994 and normalized constraints defined by the concept. */
25996 tree
25998 {
26003 else
26005 }
26007 /* Save a concept expansion for later. */
26009 tree
26011 {
26018 }
26020 static hashval_t
26022 {
26031 }
26033 /* Compare the constraints of two subsumption entries. The LEFT1 and
26034 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26035 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26037 static bool
26039 {
26047 }
26049 /* Key/value pair for learning and memoizing subsumption results. This
26050 associates a pair of check constraints (including arguments) with
26051 a boolean value indicating the result. */
26054 {
26055 tree t1;
26056 tree t2;
26058 };
26060 /* Hashing function and equality for constraint entries. */
26063 {
26065 {
26067 }
26070 {
26075 }
26076 };
26080 /* Search for a previously cached subsumption result. */
26084 {
26089 else
26091 }
26093 /* Save a subsumption result. */
26095 bool
26097 {
26104 }
26106 /* Set up the hash table for constraint association. */
26108 void
26110 {
26119 }
26121 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26122 0..N-1. */
26124 void
26126 {
26129 integer_type_node,
26130 NULL_TREE),
26134 }
26136 /* Set up the hash tables for template instantiations. */
26138 void
26140 {
26146 }
26148 /* Print stats about the template hash tables for -fstats. */
26150 void
26152 {
26161 }