| blob | 43f9ca8b39e6b9ab4aab69bf27e3028814c78370 |
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 {
6143 {
6148 else
6150 }
6152 }
6154 /* Returns TRUE iff the address of OP is value-dependent.
6156 14.6.2.4 [temp.dep.temp]:
6157 A non-integral non-type template-argument is dependent if its type is
6158 dependent or it has either of the following forms
6159 qualified-id
6160 & qualified-id
6161 and contains a nested-name-specifier which specifies a class-name that
6162 names a dependent type.
6164 We generalize this to just say that the address of a member of a
6165 dependent class is value-dependent; the above doesn't cover the
6166 address of a static data member named with an unqualified-id. */
6168 static bool
6170 {
6171 /* We could use get_inner_reference here, but there's no need;
6172 this is only relevant for template non-type arguments, which
6173 can only be expressed as &id-expression. */
6175 {
6179 }
6182 }
6184 /* The next set of functions are used for providing helpful explanatory
6185 diagnostics for failed overload resolution. Their messages should be
6186 indented by two spaces for consistency with the messages in
6187 call.c */
6189 static int
6191 {
6193 }
6195 /* Other failure functions should call this one, to provide a single function
6196 for setting a breakpoint on. */
6198 static int
6200 {
6202 }
6204 static int
6206 {
6211 }
6213 static int
6215 {
6221 }
6223 static int
6225 {
6229 }
6231 static int
6233 {
6236 " template parameter %qD is not a parameter pack, but "
6240 }
6242 static int
6244 {
6247 " template argument %qE does not match "
6251 }
6253 static int
6255 {
6259 }
6261 static int
6263 {
6269 }
6271 static int
6273 {
6275 {
6280 else
6282 " deduced conflicting values for non-type parameter "
6284 }
6286 }
6288 static int
6290 {
6293 " variable-sized array type %qT is not "
6295 arg);
6297 }
6299 static int
6301 {
6305 arg);
6307 }
6309 static int
6311 {
6313 {
6319 else
6324 }
6326 }
6328 static int
6330 {
6332 }
6334 static int
6337 {
6339 }
6341 static int
6344 {
6350 }
6352 static int
6355 {
6358 {
6366 }
6368 }
6370 static int
6372 {
6375 " template parameters of a template template argument are "
6378 }
6380 static int
6382 {
6388 }
6390 static int
6392 {
6397 }
6399 static int
6401 {
6405 arg);
6407 }
6409 /* Attempt to convert the non-type template parameter EXPR to the
6410 indicated TYPE. If the conversion is successful, return the
6411 converted value. If the conversion is unsuccessful, return
6412 NULL_TREE if we issued an error message, or error_mark_node if we
6413 did not. We issue error messages for out-and-out bad template
6414 parameters, but not simply because the conversion failed, since we
6415 might be just trying to do argument deduction. Both TYPE and EXPR
6416 must be non-dependent.
6418 The conversion follows the special rules described in
6419 [temp.arg.nontype], and it is much more strict than an implicit
6420 conversion.
6422 This function is called twice for each template argument (see
6423 lookup_template_class for a more accurate description of this
6424 problem). This means that we need to handle expressions which
6425 are not valid in a C++ source, but can be created from the
6426 first call (for instance, casts to perform conversions). These
6427 hacks can go away after we fix the double coercion problem. */
6429 static tree
6431 {
6432 tree expr_type;
6436 /* Detect immediately string literals as invalid non-type argument.
6437 This special-case is not needed for correctness (we would easily
6438 catch this later), but only to provide better diagnostic for this
6439 common user mistake. As suggested by DR 100, we do not mention
6440 linkage issues in the diagnostic as this is not the point. */
6441 /* FIXME we're making this OK. */
6443 {
6449 }
6451 /* Add the ADDR_EXPR now for the benefit of
6452 value_dependent_expression_p. */
6455 {
6459 }
6461 /* If we are in a template, EXPR may be non-dependent, but still
6462 have a syntactic, rather than semantic, form. For example, EXPR
6463 might be a SCOPE_REF, rather than the VAR_DECL to which the
6464 SCOPE_REF refers. Preserving the qualifying scope is necessary
6465 so that access checking can be performed when the template is
6466 instantiated -- but here we need the resolved form so that we can
6467 convert the argument. */
6480 else
6483 /* If the argument is non-dependent, perform any conversions in
6484 non-dependent context as well. */
6492 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6493 to a non-type argument of "nullptr". */
6497 /* In C++11, integral or enumeration non-type template arguments can be
6498 arbitrary constant expressions. Pointer and pointer to
6499 member arguments can be general constant expressions that evaluate
6500 to a null value, but otherwise still need to be of a specific form. */
6502 {
6504 /* A PTRMEM_CST is already constant, and a valid template
6505 argument for a parameter of pointer to member type, we just want
6506 to leave it in that form rather than lower it to a
6510 {
6511 /* C++17: A template-argument for a non-type template-parameter shall
6512 be a converted constant expression (8.20) of the type of the
6513 template-parameter. */
6519 }
6521 {
6526 }
6527 }
6529 /* HACK: Due to double coercion, we can get a
6530 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6531 which is the tree that we built on the first call (see
6532 below when coercing to reference to object or to reference to
6533 function). We just strip everything and get to the arg.
6534 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6535 for examples. */
6537 {
6543 {
6544 /* ??? Maybe we could use convert_from_reference here, but we
6545 would need to relax its constraints because the NOP_EXPR
6546 could actually change the type to something more cv-qualified,
6547 and this is not folded by convert_from_reference. */
6552 && (same_type_ignoring_top_level_qualifiers_p
6555 {
6558 }
6559 }
6560 }
6562 /* [temp.arg.nontype]/5, bullet 1
6564 For a non-type template-parameter of integral or enumeration type,
6565 integral promotions (_conv.prom_) and integral conversions
6566 (_conv.integral_) are applied. */
6568 {
6570 {
6575 }
6580 /* Notice that there are constant expressions like '4 % 0' which
6581 do not fold into integer constants. */
6584 {
6586 {
6590 else
6596 /* else cxx_constant_value complained but gave us
6597 a real constant, so go ahead. */
6599 }
6600 else
6602 }
6604 /* Avoid typedef problems. */
6607 }
6608 /* [temp.arg.nontype]/5, bullet 2
6610 For a non-type template-parameter of type pointer to object,
6611 qualification conversions (_conv.qual_) and the array-to-pointer
6612 conversion (_conv.array_) are applied. */
6614 {
6617 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6618 decay_conversion or an explicit cast. If it's a problematic cast,
6619 we'll complain about it below. */
6621 {
6626 {
6629 }
6630 }
6632 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6634 A template-argument for a non-type, non-template template-parameter
6635 shall be one of: [...]
6637 -- the name of a non-type template-parameter;
6638 -- the address of an object or function with external linkage, [...]
6639 expressed as "& id-expression" where the & is optional if the name
6640 refers to a function or array, or if the corresponding
6641 template-parameter is a reference.
6643 Here, we do not care about functions, as they are invalid anyway
6644 for a parameter of type pointer-to-object. */
6647 /* Non-type template parameters are OK. */
6648 ;
6652 {
6654 {
6657 "because %qD is a variable, not the address of "
6660 }
6662 {
6668 }
6669 /* Other values, like integer constants, might be valid
6670 non-type arguments of some other type. */
6672 }
6673 else
6674 {
6678 {
6683 }
6685 {
6691 }
6694 {
6699 }
6700 /* C++17: For a non-type template-parameter of reference or pointer
6701 type, the value of the constant expression shall not refer to (or
6702 for a pointer type, shall not be the address of):
6703 * a subobject (4.5),
6704 * a temporary object (15.2),
6705 * a string literal (5.13.5),
6706 * the result of a typeid expression (8.2.8), or
6707 * a predefined __func__ variable (11.4.1). */
6709 {
6712 decl);
6714 }
6718 {
6723 }
6725 {
6729 decl);
6731 }
6732 }
6739 }
6740 /* [temp.arg.nontype]/5, bullet 3
6742 For a non-type template-parameter of type reference to object, no
6743 conversions apply. The type referred to by the reference may be more
6744 cv-qualified than the (otherwise identical) type of the
6745 template-argument. The template-parameter is bound directly to the
6746 template-argument, which must be an lvalue. */
6748 {
6750 expr_type))
6754 {
6759 }
6762 {
6767 }
6769 /* [temp.arg.nontype]/1
6771 A template-argument for a non-type, non-template template-parameter
6772 shall be one of: [...]
6774 -- the address of an object or function with external linkage. */
6777 {
6780 {
6783 "because a reference variable does not have a constant "
6786 }
6787 }
6791 /* OK, dependent reference. We don't want to ask whether a DECL is
6793 else
6794 {
6796 {
6802 }
6804 /* DR 1155 allows internal linkage in C++11 and up. */
6807 {
6813 }
6816 }
6820 }
6821 /* [temp.arg.nontype]/5, bullet 4
6823 For a non-type template-parameter of type pointer to function, only
6824 the function-to-pointer conversion (_conv.func_) is applied. If the
6825 template-argument represents a set of overloaded functions (or a
6826 pointer to such), the matching function is selected from the set
6827 (_over.over_). */
6829 {
6830 /* If the argument is a template-id, we might not have enough
6831 context information to decay the pointer. */
6833 {
6837 }
6840 /* Null pointer values are OK in C++11. */
6846 }
6847 /* [temp.arg.nontype]/5, bullet 5
6849 For a non-type template-parameter of type reference to function, no
6850 conversions apply. If the template-argument represents a set of
6851 overloaded functions, the matching function is selected from the set
6852 (_over.over_). */
6854 {
6856 {
6858 {
6863 }
6865 }
6870 }
6871 /* [temp.arg.nontype]/5, bullet 6
6873 For a non-type template-parameter of type pointer to member function,
6874 no conversions apply. If the template-argument represents a set of
6875 overloaded member functions, the matching member function is selected
6876 from the set (_over.over_). */
6878 {
6883 /* [temp.arg.nontype] bullet 1 says the pointer to member
6884 expression must be a pointer-to-member constant. */
6889 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6890 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6893 }
6894 /* [temp.arg.nontype]/5, bullet 7
6896 For a non-type template-parameter of type pointer to data member,
6897 qualification conversions (_conv.qual_) are applied. */
6899 {
6900 /* [temp.arg.nontype] bullet 1 says the pointer to member
6901 expression must be a pointer-to-member constant. */
6909 }
6911 {
6913 {
6918 }
6920 }
6921 /* A template non-type parameter must be one of the above. */
6922 else
6925 /* Sanity check: did we actually convert the argument to the
6926 right type? */
6930 }
6932 /* Subroutine of coerce_template_template_parms, which returns 1 if
6933 PARM_PARM and ARG_PARM match using the rule for the template
6934 parameters of template template parameters. Both PARM and ARG are
6935 template parameters; the rest of the arguments are the same as for
6936 coerce_template_template_parms.
6937 */
6938 static int
6940 tree arg,
6941 tsubst_flags_t complain,
6942 tree in_decl,
6943 tree outer_args)
6944 {
6953 {
6955 /* We encounter instantiations of templates like
6956 template <template <template <class> class> class TT>
6957 class C; */
6958 {
6965 }
6966 /* Fall through. */
6971 /* Argument is a parameter pack but parameter is not. */
6976 /* The tsubst call is used to handle cases such as
6978 template <int> class C {};
6979 template <class T, template <T> class TT> class D {};
6980 D<int, C> d;
6982 i.e. the parameter list of TT depends on earlier parameters. */
6984 {
6989 }
6993 /* Argument is a parameter pack but parameter is not. */
7000 }
7003 }
7005 /* Coerce template argument list ARGLIST for use with template
7006 template-parameter TEMPL. */
7008 static tree
7010 tsubst_flags_t complain)
7011 {
7012 /* Consider an example where a template template parameter declared as
7014 template <class T, class U = std::allocator<T> > class TT
7016 The template parameter level of T and U are one level larger than
7017 of TT. To proper process the default argument of U, say when an
7018 instantiation `TT<int>' is seen, we need to build the full
7019 arguments containing {int} as the innermost level. Outer levels,
7020 available when not appearing as default template argument, can be
7021 obtained from the arguments of the enclosing template.
7023 Suppose that TT is later substituted with std::vector. The above
7024 instantiation is `TT<int, std::allocator<T> >' with TT at
7025 level 1, and T at level 2, while the template arguments at level 1
7026 becomes {std::vector} and the inner level 2 is {int}. */
7030 {
7032 /* We want arguments for the partial specialization, not arguments for
7033 the primary template. */
7035 else
7037 }
7039 {
7040 /* This is an argument of the current template, so we haven't set
7041 DECL_CONTEXT yet. */
7042 tree relevant_template_parms;
7044 /* Parameter levels that are greater than the level of the given
7045 template template parm are irrelevant. */
7052 }
7059 complain,
7062 }
7064 /* A cache of template template parameters with match-all default
7065 arguments. */
7067 static void
7069 {
7073 }
7074 static tree
7076 {
7081 }
7083 /* T is a bound template template-parameter. Copy its arguments into default
7084 arguments of the template template-parameter's template parameters. */
7086 static tree
7088 {
7111 {
7114 {
7117 }
7118 }
7122 }
7124 /* ARG is a bound potential template template-argument, and PARGS is a list
7125 of arguments for the corresponding template template-parameter. Adjust
7126 PARGS as appropriate for application to ARG's template, and if ARG is a
7127 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7128 arguments to the template template parameter. */
7130 static tree
7132 {
7136 {
7137 /* When comparing two template template-parameters in partial ordering,
7138 rewrite the one currently being used as an argument to have default
7139 arguments for all parameters. */
7145 }
7146 else
7147 {
7148 tree aparms
7153 }
7156 }
7158 /* Subroutine of unify for the case when PARM is a
7159 BOUND_TEMPLATE_TEMPLATE_PARM. */
7161 static int
7164 {
7168 /* The template template parm might be variadic and the argument
7169 not, so flatten both argument lists. */
7174 {
7175 /* In keeping with P0522R0, adjust P's template arguments
7176 to apply to A's template; then flatten it again. */
7185 /* If the P0522 adjustment eliminated a pack expansion, deduce
7186 empty packs. */
7192 }
7193 else
7194 {
7195 /* Deduce arguments T, i from TT<T> or TT<i>.
7196 We check each element of PARMVEC and ARGVEC individually
7197 rather than the whole TREE_VEC since they can have
7198 different number of elements, which is allowed under N2555. */
7202 /* Check if the parameters end in a pack, making them
7203 variadic. */
7210 /* If the template argument list of P contains a pack
7211 expansion that is not the last template argument, the
7212 entire template argument list is a non-deduced
7213 context. */
7231 DEDUCE_EXACT,
7234 }
7237 }
7239 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7240 template template parameters. Both PARM_PARMS and ARG_PARMS are
7241 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7242 or PARM_DECL.
7244 Consider the example:
7245 template <class T> class A;
7246 template<template <class U> class TT> class B;
7248 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7249 the parameters to A, and OUTER_ARGS contains A. */
7251 static int
7253 tree arg_parms,
7254 tsubst_flags_t complain,
7255 tree in_decl,
7256 tree outer_args)
7257 {
7269 {
7270 /* P0522R0: A template template-parameter P is at least as specialized as
7271 a template template-argument A if, given the following rewrite to two
7272 function templates, the function template corresponding to P is at
7273 least as specialized as the function template corresponding to A
7274 according to the partial ordering rules for function templates
7275 ([temp.func.order]). Given an invented class template X with the
7276 template parameter list of A (including default arguments):
7278 * Each of the two function templates has the same template parameters,
7279 respectively, as P or A.
7281 * Each function template has a single function parameter whose type is
7282 a specialization of X with template arguments corresponding to the
7283 template parameters from the respective function template where, for
7284 each template parameter PP in the template parameter list of the
7285 function template, a corresponding template argument AA is formed. If
7286 PP declares a parameter pack, then AA is the pack expansion
7287 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7289 If the rewrite produces an invalid type, then P is not at least as
7290 specialized as A. */
7292 /* So coerce P's args to apply to A's parms, and then deduce between A's
7293 args and the converted args. If that succeeds, A is at least as
7294 specialized as P, so they match.*/
7301 {
7307 }
7308 }
7310 /* Determine whether we have a parameter pack at the end of the
7311 template template parameter's template parameter list. */
7313 {
7320 {
7334 }
7335 }
7341 /* Check all of the template parameters except the parameter pack at
7342 the end (if any). */
7344 {
7353 outer_args))
7356 }
7359 {
7360 /* Check each of the template parameters in the template
7361 argument against the template parameter pack at the end of
7362 the template template parameter. */
7369 {
7376 outer_args))
7378 }
7379 }
7382 }
7384 /* Verifies that the deduced template arguments (in TARGS) for the
7385 template template parameters (in TPARMS) represent valid bindings,
7386 by comparing the template parameter list of each template argument
7387 to the template parameter list of its corresponding template
7388 template parameter, in accordance with DR150. This
7389 routine can only be called after all template arguments have been
7390 deduced. It will return TRUE if all of the template template
7391 parameter bindings are okay, FALSE otherwise. */
7392 bool
7394 {
7398 /* We're dealing with template parms in this process. */
7404 {
7409 {
7414 {
7415 /* Look inside the argument pack. */
7418 }
7421 {
7425 /* Extract the next argument from the argument
7426 pack. */
7430 /* Look at the pattern of the pack expansion. */
7433 /* Extract the template parameters from the template
7434 argument. */
7440 /* Verify that we can coerce the template template
7441 parameters from the template argument to the template
7442 parameter. This requires an exact match. */
7444 && !coerce_template_template_parms
7446 targ_parms,
7447 tf_none,
7448 tparm,
7449 targs))
7450 {
7453 }
7454 }
7455 }
7456 }
7458 out:
7462 }
7464 /* Since type attributes aren't mangled, we need to strip them from
7465 template type arguments. */
7467 static tree
7469 {
7479 }
7481 /* And from inside dependent non-type arguments like sizeof(Type). */
7483 static tree
7485 {
7495 }
7497 // A template declaration can be substituted for a constrained
7498 // template template parameter only when the argument is more
7499 // constrained than the parameter.
7500 static bool
7502 {
7505 /* For now, allow constrained template template arguments
7506 and unconstrained template template parameters. */
7512 // If the template parameter is constrained, we need to rewrite its
7513 // constraints in terms of the ARG's template parameters. This ensures
7514 // that all of the template parameter types will have the same depth.
7515 //
7516 // Note that this is only valid when coerce_template_template_parm is
7517 // true for the innermost template parameters of PARM and ARG. In other
7518 // words, because coercion is successful, this conversion will be valid.
7520 {
7527 }
7530 }
7532 // Convert a placeholder argument into a binding to the original
7533 // parameter. The original parameter is saved as the TREE_TYPE of
7534 // ARG.
7537 {
7540 }
7542 /* Convert the indicated template ARG as necessary to match the
7543 indicated template PARM. Returns the converted ARG, or
7544 error_mark_node if the conversion was unsuccessful. Error and
7545 warning messages are issued under control of COMPLAIN. This
7546 conversion is for the Ith parameter in the parameter list. ARGS is
7547 the full set of template arguments deduced so far. */
7549 static tree
7551 tree arg,
7552 tree args,
7553 tsubst_flags_t complain,
7555 tree in_decl)
7556 {
7557 tree orig_arg;
7558 tree val;
7564 /* Trivially convert placeholders. */
7573 {
7574 /* The template argument was the name of some
7575 member function. That's usually
7576 invalid, but static members are OK. In any
7577 case, grab the underlying fields/functions
7578 and issue an error later if required. */
7581 }
7589 /* When determining whether an argument pack expansion is a template,
7590 look at the pattern. */
7594 /* Deal with an injected-class-name used as a template template arg. */
7596 {
7599 {
7609 }
7610 }
7612 is_tmpl_type =
7628 {
7630 {
7634 }
7637 "to refer to a type member of a template parameter, "
7642 typename_type,
7643 complain);
7646 }
7648 {
7650 {
7652 {
7664 else
7667 }
7668 }
7670 }
7672 {
7674 {
7681 else
7684 }
7686 }
7689 /* We already did the appropriate conversion when packing args. */
7692 {
7694 {
7696 /* The number of argument required is not known yet.
7697 Just accept it for now. */
7699 else
7700 {
7702 tree argparm;
7704 /* Strip alias templates that are equivalent to another
7705 template. */
7711 args))
7712 {
7715 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7716 TEMPLATE_DECL. */
7718 {
7723 }
7724 }
7725 else
7726 {
7728 {
7735 }
7738 }
7740 // Check that the constraints are compatible before allowing the
7741 // substitution.
7744 {
7746 {
7752 }
7754 }
7755 }
7756 }
7757 else
7759 /* We only form one instance of each template specialization.
7760 Therefore, if we use a non-canonical variant (i.e., a
7761 typedef), any future messages referring to the type will use
7762 the typedef, which is confusing if those future uses do not
7763 themselves also use the typedef. */
7766 }
7767 else
7768 {
7772 {
7776 }
7777 else
7785 /* We used to call digest_init here. However, digest_init
7786 will report errors, which we don't want when complain
7787 is zero. More importantly, digest_init will try too
7788 hard to convert things: for example, `0' should not be
7789 converted to pointer type at this point according to
7790 the standard. Accepting this is not merely an
7791 extension, since deciding whether or not these
7792 conversions can occur is part of determining which
7793 function template to call, or whether a given explicit
7794 argument specification is valid. */
7796 else
7806 {
7807 /* Reject template arguments that are references to built-in
7808 functions with no library fallbacks. */
7817 }
7820 {
7821 /* Strip typedefs from the SCOPE_REF. */
7824 complain);
7827 }
7828 }
7831 }
7833 /* Coerces the remaining template arguments in INNER_ARGS (from
7834 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7835 Returns the coerced argument pack. PARM_IDX is the position of this
7836 parameter in the template parameter list. ARGS is the original
7837 template argument list. */
7838 static tree
7841 tree args,
7842 tree inner_args,
7844 tree new_args,
7846 tree in_decl,
7847 tsubst_flags_t complain)
7848 {
7851 tree packed_args;
7852 tree argument_pack;
7859 {
7860 /* When the template parameter is a non-type template parameter pack
7861 or template template parameter pack whose type or template
7862 parameters use parameter packs, we know exactly how many arguments
7863 we are looking for. Build a vector of the instantiated decls for
7864 these template parameters in PACKED_PARMS. */
7865 /* We can't use make_pack_expansion here because it would interpret a
7866 _DECL as a use rather than a declaration. */
7880 /* If we're doing a partial instantiation of a member template,
7881 verify that all of the types used for the non-type
7882 template parameter pack are, in fact, valid for non-type
7883 template parameters. */
7886 {
7889 {
7893 }
7894 /* We don't know how many args we have yet, just
7895 use the unconverted ones for now. */
7897 }
7900 }
7901 /* Check if we have a placeholder pack, which indicates we're
7902 in the context of a introduction list. In that case we want
7903 to match this pack to the single placeholder. */
7907 {
7910 }
7911 else
7914 /* Convert the remaining arguments, which will be a part of the
7915 parameter pack "parm". */
7918 {
7924 {
7925 /* Once we've packed as many args as we have types, stop. */
7929 /* We don't know how many args we have yet, just
7930 use the unconverted ones for now. */
7932 else
7934 }
7937 {
7940 }
7941 else
7944 in_decl);
7948 }
7952 {
7957 }
7962 else
7963 {
7966 }
7973 }
7975 /* Returns the number of pack expansions in the template argument vector
7976 ARGS. */
7978 static int
7980 {
7985 {
7989 }
7991 }
7993 /* Convert all template arguments to their appropriate types, and
7994 return a vector containing the innermost resulting template
7995 arguments. If any error occurs, return error_mark_node. Error and
7996 warning messages are issued under control of COMPLAIN.
7998 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7999 for arguments not specified in ARGS. Otherwise, if
8000 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8001 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8002 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8003 ARGS. */
8005 static tree
8007 tree args,
8008 tree in_decl,
8009 tsubst_flags_t complain,
8012 {
8014 tree orig_inner_args;
8015 tree inner_args;
8016 tree new_args;
8017 tree new_inner_args;
8021 /* When used as a boolean value, indicates whether this is a
8022 variadic template parameter list. Since it's an int, we can also
8023 subtract it from nparms to get the number of non-variadic
8024 parameters. */
8029 /* Likewise for parameters with default arguments. */
8037 /* Determine if there are any parameter packs or default arguments. */
8039 {
8047 }
8050 /* If there are no parameters that follow a parameter pack, we need to
8051 expand any argument packs so that we can deduce a parameter pack from
8052 some non-packed args followed by an argument pack, as in variadic85.C.
8053 If there are such parameters, we need to leave argument packs intact
8054 so the arguments are assigned properly. This can happen when dealing
8055 with a nested class inside a partial specialization of a class
8056 template, as in variadic92.C, or when deducing a template parameter pack
8057 from a sub-declarator, as in variadic114.C. */
8061 /* Count any pack expansion args. */
8067 && require_all_args
8068 && !variadic_args_p
8069 && (!use_default_args
8072 {
8074 {
8076 {
8080 }
8081 else
8088 }
8091 }
8092 /* We can't pass a pack expansion to a non-pack parameter of an alias
8093 template (DR 1430). */
8097 && variadic_args_p
8099 {
8101 {
8103 {
8109 {
8112 "pack expansion argument for non-pack parameter "
8114 else
8116 "pack expansion argument for non-pack parameter "
8120 }
8121 }
8123 found:;
8124 }
8126 }
8128 /* We need to evaluate the template arguments, even though this
8129 template-id may be nested within a "sizeof". */
8138 {
8139 tree arg;
8140 tree parm;
8142 /* Get the Ith template parameter. */
8146 {
8149 }
8151 /* Calculate the next argument. */
8154 else
8159 {
8160 /* Some arguments will be placed in the
8161 template parameter pack PARM. */
8168 {
8169 /* We don't know how many args we have yet, just use the
8170 unconverted (and still packed) ones for now. */
8174 }
8178 /* Store this argument. */
8180 {
8181 lost++;
8182 /* We are done with all of the arguments. */
8184 }
8185 else
8186 {
8189 }
8192 }
8194 {
8196 {
8197 /* "If every valid specialization of a variadic template
8198 requires an empty template parameter pack, the template is
8199 ill-formed, no diagnostic required." So check that the
8200 pattern works with this parameter. */
8205 in_decl);
8207 {
8212 }
8214 /* Recover from missing typename. */
8218 /* We don't know how many args we have yet, just
8219 use the unconverted ones for now. */
8223 }
8224 }
8226 {
8227 /* There must be a default arg in this case. */
8230 /* The position of the first default template argument,
8231 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8232 Record that. */
8236 }
8237 else
8241 {
8244 }
8246 /* This only occurs if there was an error in the template
8247 parameter list itself (which we would already have
8248 reported) that we are trying to recover from, e.g., a class
8249 template with a parameter list such as
8250 template<typename..., typename>. */
8252 else
8258 lost++;
8260 }
8265 {
8267 {
8272 }
8274 }
8284 }
8286 /* Convert all template arguments to their appropriate types, and
8287 return a vector containing the innermost resulting template
8288 arguments. If any error occurs, return error_mark_node. Error and
8289 warning messages are not issued.
8291 Note that no function argument deduction is performed, and default
8292 arguments are used to fill in unspecified arguments. */
8293 tree
8295 {
8297 }
8299 /* Convert all template arguments to their appropriate type, and
8300 instantiate default arguments as needed. This returns a vector
8301 containing the innermost resulting template arguments, or
8302 error_mark_node if unsuccessful. */
8303 tree
8305 tsubst_flags_t complain)
8306 {
8308 }
8310 /* Like coerce_template_parms. If PARMS represents all template
8311 parameters levels, this function returns a vector of vectors
8312 representing all the resulting argument levels. Note that in this
8313 case, only the innermost arguments are coerced because the
8314 outermost ones are supposed to have been coerced already.
8316 Otherwise, if PARMS represents only (the innermost) vector of
8317 parameters, this function returns a vector containing just the
8318 innermost resulting arguments. */
8320 static tree
8322 tree args,
8323 tree in_decl,
8324 tsubst_flags_t complain,
8327 {
8330 tree coerced_args;
8333 {
8335 tree level;
8341 {
8342 tree l;
8346 require_all_args,
8347 use_default_args);
8348 else
8355 }
8356 }
8357 else
8360 require_all_args,
8361 use_default_args);
8363 }
8365 /* Returns 1 if template args OT and NT are equivalent. */
8367 int
8369 {
8378 /* For member templates */
8387 {
8404 }
8408 {
8411 /* Don't treat an alias template specialization with dependent
8412 arguments as equivalent to its underlying type when used as a
8413 template argument; we need them to be distinct so that we
8414 substitute into the specialization arguments at instantiation
8415 time. And aliases can't be equivalent without being ==, so
8416 we don't need to look any deeper.
8418 During partial ordering, however, we need to treat them normally so
8419 that we can order uses of the same alias with different
8420 cv-qualification (79960). */
8424 else
8426 }
8429 else
8430 {
8431 /* Try to treat a template non-type argument that has been converted
8432 to the parameter type as equivalent to one that hasn't yet. */
8445 }
8446 }
8448 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8449 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8450 NEWARG_PTR with the offending arguments if they are non-NULL. */
8452 int
8456 {
8469 {
8474 {
8480 }
8481 }
8483 }
8487 {
8489 }
8491 static void
8493 {
8503 /* We are called both from instantiate_decl, where we've already had a
8504 tinst_level pushed, and instantiate_template, where we haven't.
8505 Compensate. */
8516 else
8525 }
8528 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8529 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8530 documentation for TEMPLATE_ID_EXPR. */
8532 tree
8534 {
8535 tree type;
8543 {
8546 }
8549 {
8551 unknown_type_node,
8553 arglist);
8555 }
8562 }
8564 /* Within the scope of a template class S<T>, the name S gets bound
8565 (in build_self_reference) to a TYPE_DECL for the class, not a
8566 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8567 or one of its enclosing classes, and that type is a template,
8568 return the associated TEMPLATE_DECL. Otherwise, the original
8569 DECL is returned.
8571 Also handle the case when DECL is a TREE_LIST of ambiguous
8572 injected-class-names from different bases. */
8574 tree
8576 {
8580 /* DR 176: A lookup that finds an injected-class-name (10.2
8581 [class.member.lookup]) can result in an ambiguity in certain cases
8582 (for example, if it is found in more than one base class). If all of
8583 the injected-class-names that are found refer to specializations of
8584 the same class template, and if the name is followed by a
8585 template-argument-list, the reference refers to the class template
8586 itself and not a specialization thereof, and is not ambiguous. */
8588 {
8591 {
8597 }
8600 else
8602 }
8608 }
8610 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8611 parameters, find the desired type.
8613 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8615 IN_DECL, if non-NULL, is the template declaration we are trying to
8616 instantiate.
8618 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8619 the class we are looking up.
8621 Issue error and warning messages under control of COMPLAIN.
8623 If the template class is really a local class in a template
8624 function, then the FUNCTION_CONTEXT is the function in which it is
8625 being instantiated.
8627 ??? Note that this function is currently called *twice* for each
8628 template-id: the first time from the parser, while creating the
8629 incomplete type (finish_template_type), and the second type during the
8630 real instantiation (instantiate_template_class). This is surely something
8631 that we want to avoid. It also causes some problems with argument
8632 coercion (see convert_nontype_argument for more information on this). */
8634 static tree
8637 {
8639 tree t;
8642 spec_entry elt;
8643 hashval_t hash;
8646 {
8650 else
8651 {
8658 }
8661 }
8663 {
8666 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8667 an implicit typename for the second A. Deal with it. */
8672 {
8675 }
8676 }
8679 {
8682 }
8684 {
8688 }
8690 {
8693 }
8695 /* Issue an error message if we didn't find a template. */
8697 {
8701 }
8704 /* Make sure it's a user visible template, if it was named by
8705 the user. */
8708 {
8710 {
8714 }
8716 }
8720 /* An alias that just changes the name of a template is equivalent to the
8721 other template, so if any of the arguments are pack expansions, strip
8722 the alias to avoid problems with a pack expansion passed to a non-pack
8723 alias template parameter (DR 1430). */
8728 {
8729 tree parm;
8738 }
8739 else
8740 {
8742 tree gen_tmpl;
8743 tree type_decl;
8751 /* An error occurred while building the template TEMPL, and a
8752 diagnostic has most certainly been emitted for that
8753 already. Let's propagate that error. */
8762 {
8763 /* We've been given an incomplete set of template arguments.
8764 For example, given:
8766 template <class T> struct S1 {
8767 template <class U> struct S2 {};
8768 template <class U> struct S2<U*> {};
8769 };
8771 we will be called with an ARGLIST of `U*', but the
8772 TEMPLATE will be `template <class T> template
8773 <class U> struct S1<T>::S2'. We must fill in the missing
8774 arguments. */
8778 }
8780 /* Now we should have enough arguments. */
8783 /* From here on, we're only interested in the most general
8784 template. */
8786 /* Calculate the BOUND_ARGS. These will be the args that are
8787 actually tsubst'd into the definition to create the
8788 instantiation. */
8790 complain,
8795 /* We were unable to bind the arguments. */
8798 /* In the scope of a template class, explicit references to the
8799 template class refer to the type of the template, not any
8800 instantiation of it. For example, in:
8802 template <class T> class C { void f(C<T>); }
8804 the `C<T>' is just the same as `C'. Outside of the
8805 class, however, such a reference is an instantiation. */
8809 {
8814 }
8816 /* If we already have this specialization, return it. */
8826 /* If the the template's constraints are not satisfied,
8827 then we cannot form a valid type.
8829 Note that the check is deferred until after the hash
8830 lookup. This prevents redundant checks on previously
8831 instantiated specializations. */
8833 {
8835 {
8838 }
8840 }
8844 /* If the deduced arguments are invalid, then the binding
8845 failed. */
8849 complain))
8856 {
8861 }
8871 /* Create the type. */
8873 {
8874 /* The user referred to a specialization of an alias
8875 template represented by GEN_TMPL.
8877 [temp.alias]/2 says:
8879 When a template-id refers to the specialization of an
8880 alias template, it is equivalent to the associated
8881 type obtained by substitution of its
8882 template-arguments for the template-parameters in the
8883 type-id of the alias template. */
8886 /* Note that the call above (by indirectly calling
8887 register_specialization in tsubst_decl) registers the
8888 TYPE_DECL representing the specialization of the alias
8889 template. So next time someone substitutes ARGLIST for
8890 the template parms into the alias template (GEN_TMPL),
8891 she'll get that TYPE_DECL back. */
8895 }
8897 {
8899 {
8910 }
8911 else
8912 {
8913 /* We don't want to call start_enum for this type, since
8914 the values for the enumeration constants may involve
8915 template parameters. And, no one should be interested
8916 in the enumeration constants for such a type. */
8919 }
8923 }
8925 {
8931 /* A local class. Make sure the decl gets registered properly. */
8936 /* This instantiation is another name for the primary
8937 template type. Set the TYPE_CANONICAL field
8938 appropriately. */
8941 /* Some of the template arguments require structural
8942 equality testing, so this template class requires
8943 structural equality testing. */
8945 }
8946 else
8949 /* If we called start_enum or pushtag above, this information
8950 will already be set up. */
8952 {
8959 }
8960 else
8964 {
8970 {
8973 }
8974 }
8978 {
8982 {
8983 tree attributes
8991 }
8992 }
8994 /* Let's consider the explicit specialization of a member
8995 of a class template specialization that is implicitly instantiated,
8996 e.g.:
8997 template<class T>
8998 struct S
8999 {
9000 template<class U> struct M {}; //#0
9001 };
9003 template<>
9004 template<>
9005 struct S<int>::M<char> //#1
9006 {
9007 int i;
9008 };
9009 [temp.expl.spec]/4 says this is valid.
9011 In this case, when we write:
9012 S<int>::M<char> m;
9014 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9015 the one of #0.
9017 When we encounter #1, we want to store the partial instantiation
9018 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9020 For all cases other than this "explicit specialization of member of a
9021 class template", we just want to store the most general template into
9022 the CLASSTYPE_TI_TEMPLATE of M.
9024 This case of "explicit specialization of member of a class template"
9025 only happens when:
9026 1/ the enclosing class is an instantiation of, and therefore not
9027 the same as, the context of the most general template, and
9028 2/ we aren't looking at the partial instantiation itself, i.e.
9029 the innermost arguments are not the same as the innermost parms of
9030 the most general template.
9032 So it's only when 1/ and 2/ happens that we want to use the partial
9033 instantiation of the member template in lieu of its most general
9034 template. */
9038 /* the enclosing class must be an instantiation... */
9041 {
9045 tree partial_inst_args =
9052 use_partial_inst_tmpl =
9053 /*...and we must not be looking at the partial instantiation
9054 itself. */
9056 partial_inst_args);
9057 }
9060 /* This case is easy; there are no member templates involved. */
9062 else
9063 {
9064 /* This is a full instantiation of a member template. Find
9065 the partial instantiation of which this is an instance. */
9067 /* Temporarily reduce by one the number of levels in the ARGLIST
9068 so as to avoid comparing the last set of arguments. */
9072 /* FOUND is either a proper class type, or an alias
9073 template specialization. In the later case, it's a
9074 TYPE_DECL, resulting from the substituting of arguments
9075 for parameters in the TYPE_DECL of the alias template
9076 done earlier. So be careful while getting the template
9077 of FOUND. */
9079 ? found
9083 }
9085 // Build template info for the new specialization.
9094 /* Note this use of the partial instantiation so we can check it
9095 later in maybe_process_partial_specialization. */
9102 /* Now that the type has been registered on the instantiations
9103 list, we set up the enumerators. Because the enumeration
9104 constants may involve the enumeration type itself, we make
9105 sure to register the type first, and then create the
9106 constants. That way, doing tsubst_expr for the enumeration
9107 constants won't result in recursive calls here; we'll find
9108 the instantiation and exit above. */
9112 /* If the type makes use of template parameters, the
9113 code that generates debugging information will crash. */
9116 /* Possibly limit visibility based on template args. */
9123 }
9124 }
9126 /* Wrapper for lookup_template_class_1. */
9128 tree
9131 {
9132 tree ret;
9138 }
9140 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9142 tree
9144 {
9145 /* The type of the expression is NULL_TREE since the template-id could refer
9146 to an explicit or partial specialization. */
9149 /* Except that concepts are always bool. */
9152 }
9154 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9156 tree
9158 {
9162 /* We never want to return a VAR_DECL for a variable concept, since they
9163 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9178 {
9180 {
9183 }
9185 }
9187 /* If a template-id refers to a specialization of a variable
9188 concept, then the expression is true if and only if the
9189 concept's constraints are satisfied by the given template
9190 arguments.
9192 NOTE: This is an extension of Concepts Lite TS that
9193 allows constraints to be used in expressions. */
9195 {
9198 }
9201 }
9203 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9204 TARGS template args, and instantiate it if it's not dependent. */
9206 tree
9208 tsubst_flags_t complain)
9209 {
9212 {
9215 }
9218 }
9220 \f
9221 struct pair_fn_data
9222 {
9223 tree_fn_t fn;
9224 tree_fn_t any_fn;
9226 /* True when we should also visit template parameters that occur in
9227 non-deduced contexts. */
9230 };
9232 /* Called from for_each_template_parm via walk_tree. */
9234 static tree
9236 {
9243 #define WALK_SUBTREE(NODE) \
9244 do \
9245 { \
9246 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9247 pfd->include_nondeduced_p, \
9248 pfd->any_fn); \
9249 if (result) goto out; \
9250 } \
9251 while (0)
9261 {
9265 /* Fall through. */
9271 else
9281 /* Since we're not going to walk subtrees, we have to do this
9282 explicitly here. */
9284 /* Fall through. */
9287 /* Check the return type. */
9290 /* Check the parameter types. Since default arguments are not
9291 instantiated until they are needed, the TYPE_ARG_TYPES may
9292 contain expressions that involve template parameters. But,
9293 no-one should be looking at them yet. And, once they're
9294 instantiated, they don't contain template parameters, so
9295 there's no point in looking at them then, either. */
9296 {
9297 tree parm;
9302 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9303 want walk_tree walking into them itself. */
9305 }
9308 {
9312 }
9329 /* Fall through. */
9341 /* Record template parameters such as `T' inside `TT<T>'. */
9343 /* Fall through. */
9355 /* A template template parameter is encountered. */
9359 /* Already substituted template template parameter */
9364 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9365 partial instantiation. */
9377 /* If there's no type, then this thing must be some expression
9378 involving template parameters. */
9400 }
9402 #undef WALK_SUBTREE
9404 /* We didn't find any template parameters we liked. */
9405 out:
9407 }
9409 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9410 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9411 call FN with the parameter and the DATA.
9412 If FN returns nonzero, the iteration is terminated, and
9413 for_each_template_parm returns 1. Otherwise, the iteration
9414 continues. If FN never returns a nonzero value, the value
9415 returned by for_each_template_parm is 0. If FN is NULL, it is
9416 considered to be the function which always returns 1.
9418 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9419 parameters that occur in non-deduced contexts. When false, only
9420 visits those template parameters that can be deduced. */
9422 static tree
9426 tree_fn_t any_fn)
9427 {
9429 tree result;
9431 /* Set up. */
9437 /* Walk the tree. (Conceptually, we would like to walk without
9438 duplicates, but for_each_template_parm_r recursively calls
9439 for_each_template_parm, so we would need to reorganize a fair
9440 bit to use walk_tree_without_duplicates, so we keep our own
9441 visited list.) */
9444 else
9447 for_each_template_parm_r,
9451 /* Clean up. */
9453 {
9456 }
9459 }
9461 /* Returns true if T depends on any template parameter. */
9463 int
9465 {
9495 else
9496 {
9499 }
9504 }
9506 /* Returns true iff current_function_decl is an incompletely instantiated
9507 template. Useful instead of processing_template_decl because the latter
9508 is set to 0 during instantiate_non_dependent_expr. */
9510 bool
9512 {
9521 }
9523 /* Returns true if T depends on any template parameter with level LEVEL. */
9525 bool
9527 {
9530 }
9532 /* Returns true if the signature of DECL depends on any template parameter from
9533 its enclosing class. */
9535 bool
9537 {
9547 template_parm_outer_level,
9557 }
9559 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9560 ill-formed translation unit, i.e. a variable or function that isn't
9561 usable in a constant expression. */
9565 {
9569 }
9571 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9572 neglectable and instantiated from within an erroneous instantiation. */
9574 static bool
9576 {
9587 }
9595 /* We're starting to instantiate D; record the template instantiation context
9596 for diagnostics and to restore it later. */
9598 bool
9600 {
9602 }
9604 /* We're starting to instantiate D; record the template instantiation context
9605 at LOC for diagnostics and to restore it later. */
9607 bool
9609 {
9613 {
9614 /* Tell error.c not to try to instantiate any templates. */
9617 "template instantiation depth exceeds maximum of %d"
9619 max_tinst_depth);
9621 }
9623 /* If the current instantiation caused problems, don't let it instantiate
9624 anything else. Do allow deduction substitution and decls usable in
9625 constant expressions. */
9629 /* When not -quiet, dump template instantiations other than functions, since
9630 announce_function will take care of those. */
9649 }
9651 /* We're done instantiating this template; return to the instantiation
9652 context. */
9654 void
9656 {
9657 /* Restore the filename and line number stashed away when we started
9658 this instantiation. */
9662 }
9664 /* We're instantiating a deferred template; restore the template
9665 instantiation context in which the instantiation was requested, which
9666 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9668 static tree
9670 {
9682 }
9684 /* Returns the TINST_LEVEL which gives the original instantiation
9685 context. */
9689 {
9695 }
9697 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9698 vector of template arguments, as for tsubst.
9700 Returns an appropriate tsubst'd friend declaration. */
9702 static tree
9704 {
9705 tree new_friend;
9710 /* This was a friend declared with an explicit template
9711 argument list, e.g.:
9713 friend void f<>(T);
9715 to indicate that f was a template instantiation, not a new
9716 function declaration. Now, we have to figure out what
9717 instantiation of what template. */
9718 {
9720 tree new_args;
9721 tree tmpl;
9724 /* Friend functions are looked up in the containing namespace scope.
9725 We must enter that scope, to avoid finding member functions of the
9726 current class with same name. */
9741 tsk_none);
9743 }
9747 /* The NEW_FRIEND will look like an instantiation, to the
9748 compiler, but is not an instantiation from the point of view of
9749 the language. For example, we might have had:
9751 template <class T> struct S {
9752 template <class U> friend void f(T, U);
9753 };
9755 Then, in S<int>, template <class U> void f(int, U) is not an
9756 instantiation of anything. */
9762 {
9766 }
9768 /* The mangled name for the NEW_FRIEND is incorrect. The function
9769 is not a template instantiation and should not be mangled like
9770 one. Therefore, we forget the mangling here; we'll recompute it
9771 later if we need it. */
9773 {
9776 }
9779 {
9780 tree old_decl;
9781 tree new_friend_template_info;
9782 tree new_friend_result_template_info;
9783 tree ns;
9786 /* We must save some information from NEW_FRIEND before calling
9787 duplicate decls since that function will free NEW_FRIEND if
9788 possible. */
9790 new_friend_is_defn =
9795 {
9796 /* This declaration is a `primary' template. */
9799 new_friend_result_template_info
9801 }
9802 else
9805 /* Inside pushdecl_namespace_level, we will push into the
9806 current namespace. However, the friend function should go
9807 into the namespace of the template. */
9817 {
9818 /* This new friend declaration matched an existing
9819 declaration. For example, given:
9821 template <class T> void f(T);
9822 template <class U> class C {
9823 template <class T> friend void f(T) {}
9824 };
9826 the friend declaration actually provides the definition
9827 of `f', once C has been instantiated for some type. So,
9828 old_decl will be the out-of-class template declaration,
9829 while new_friend is the in-class definition.
9831 But, if `f' was called before this point, the
9832 instantiation of `f' will have DECL_TI_ARGS corresponding
9833 to `T' but not to `U', references to which might appear
9834 in the definition of `f'. Previously, the most general
9835 template for an instantiation of `f' was the out-of-class
9836 version; now it is the in-class version. Therefore, we
9837 run through all specialization of `f', adding to their
9838 DECL_TI_ARGS appropriately. In particular, they need a
9839 new set of outer arguments, corresponding to the
9840 arguments for this class instantiation.
9842 The same situation can arise with something like this:
9844 friend void f(int);
9845 template <class T> class C {
9846 friend void f(T) {}
9847 };
9849 when `C<int>' is instantiated. Now, `f(int)' is defined
9850 in the class. */
9853 /* On the other hand, if the in-class declaration does
9854 *not* provide a definition, then we don't want to alter
9855 existing definitions. We can just leave everything
9856 alone. */
9857 ;
9858 else
9859 {
9863 /* Overwrite whatever template info was there before, if
9864 any, with the new template information pertaining to
9865 the declaration. */
9869 {
9870 /* We should have called reregister_specialization in
9871 duplicate_decls. */
9876 /* Instantiate it if the global has already been used. */
9880 }
9881 else
9882 {
9883 tree t;
9885 /* Indicate that the old function template is a partial
9886 instantiation. */
9894 /* Reassign any specializations already in the hash table
9895 to the new more general template, and add the
9896 additional template args. */
9900 {
9902 spec_entry elt;
9914 register_specialization
9917 }
9919 }
9920 }
9922 /* The information from NEW_FRIEND has been merged into OLD_DECL
9923 by duplicate_decls. */
9925 }
9926 }
9927 else
9928 {
9932 /* In the code
9933 template <class T> class C {
9934 template <class U> friend void C1<U>::f (); // case 1
9935 friend void C2<T>::f (); // case 2
9936 };
9937 we only need to make sure CONTEXT is a complete type for
9938 case 2. To distinguish between the two cases, we note that
9939 CONTEXT of case 1 remains dependent type after tsubst while
9940 this isn't true for case 2. */
9950 {
9952 /* do_friend adds the TEMPLATE_DECL for any member friend
9953 template even if it isn't a member template, i.e.
9954 template <class T> friend A<T>::f();
9955 Look through it in that case. */
9959 /* Check to see that the declaration is really present, and,
9960 possibly obtain an improved declaration. */
9965 }
9966 }
9969 }
9971 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9972 template arguments, as for tsubst.
9974 Returns an appropriate tsubst'd friend type or error_mark_node on
9975 failure. */
9977 static tree
9979 {
9980 tree friend_type;
9981 tree tmpl;
9982 tree context;
9985 {
9988 }
9993 {
9996 else
9998 }
10000 /* Look for a class template declaration. We look for hidden names
10001 because two friend declarations of the same template are the
10002 same. For example, in:
10004 struct A {
10005 template <typename> friend class F;
10006 };
10007 template <typename> struct B {
10008 template <typename> friend class F;
10009 };
10011 both F templates are the same. */
10015 /* But, if we don't find one, it might be because we're in a
10016 situation like this:
10018 template <class T>
10019 struct S {
10020 template <class U>
10021 friend struct S;
10022 };
10024 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
10025 for `S<int>', not the TEMPLATE_DECL. */
10027 {
10030 }
10033 {
10034 /* The friend template has already been declared. Just
10035 check to see that the declarations match, and install any new
10036 default parameters. We must tsubst the default parameters,
10037 of course. We only need the innermost template parameters
10038 because that is all that redeclare_class_template will look
10039 at. */
10042 {
10043 tree parms;
10044 location_t saved_input_location;
10054 }
10057 }
10058 else
10059 {
10060 /* The friend template has not already been declared. In this
10061 case, the instantiation of the template class will cause the
10062 injection of this template into the global scope. */
10067 /* The new TMPL is not an instantiation of anything, so we
10068 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10069 the new type because that is supposed to be the corresponding
10070 template decl, i.e., TMPL. */
10077 /* Inject this template into the global scope. */
10079 }
10082 {
10085 else
10087 }
10090 }
10092 /* Returns zero if TYPE cannot be completed later due to circularity.
10093 Otherwise returns one. */
10095 static int
10097 {
10107 else
10109 }
10114 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10115 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10117 static tree
10120 {
10129 {
10136 clauses
10140 else
10142 }
10143 /* If the first attribute argument is an identifier, don't
10144 pass it through tsubst. Attributes like mode, format,
10145 cleanup and several target specific attributes expect it
10146 unmodified. */
10148 {
10149 tree chain
10154 }
10156 {
10157 /* An attribute pack expansion. */
10166 {
10170 }
10172 }
10173 else
10180 }
10182 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10183 unchanged or a new TREE_LIST chain. */
10185 static tree
10188 {
10193 {
10197 }
10201 {
10204 {
10207 {
10209 do
10214 }
10215 }
10217 }
10220 }
10222 /* Apply any attributes which had to be deferred until instantiation
10223 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10224 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10226 static void
10229 {
10231 tree t;
10238 {
10242 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10243 to our attributes parameter. */
10245 }
10246 else
10247 {
10249 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10250 lookup_template_class_1, and should be preserved. */
10254 }
10258 {
10262 }
10266 {
10271 {
10274 {
10278 do
10281 }
10282 else
10284 }
10287 }
10288 }
10290 /* Perform (or defer) access check for typedefs that were referenced
10291 from within the template TMPL code.
10292 This is a subroutine of instantiate_decl and instantiate_class_template.
10293 TMPL is the template to consider and TARGS is the list of arguments of
10294 that template. */
10296 static void
10298 {
10299 location_t saved_location;
10310 {
10322 /* Make access check error messages point to the location
10323 of the use of the typedef. */
10327 tf_warning_or_error);
10328 }
10330 }
10332 static tree
10334 {
10336 tree typedecl;
10337 tree pbinfo;
10338 tree base_list;
10340 tree fn_context;
10349 /* Figure out which template is being instantiated. */
10353 /* Determine what specialization of the original template to
10354 instantiate. */
10357 {
10360 }
10362 {
10363 /* This TYPE is actually an instantiation of a partial
10364 specialization. We replace the innermost set of ARGS with
10365 the arguments appropriate for substitution. For example,
10366 given:
10368 template <class T> struct S {};
10369 template <class T> struct S<T*> {};
10371 and supposing that we are instantiating S<int*>, ARGS will
10372 presently be {int*} -- but we need {int}. */
10375 }
10376 else
10377 {
10380 }
10382 /* If the template we're instantiating is incomplete, then clearly
10383 there's nothing we can do. */
10387 /* If we've recursively instantiated too many templates, stop. */
10391 /* Now we're really doing the instantiation. Mark the type as in
10392 the process of being defined. */
10395 /* We may be in the middle of deferred access check. Disable
10396 it now. */
10403 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10408 else
10409 {
10412 }
10413 /* Use #pragma pack from the template context. */
10419 /* Set the input location to the most specialized template definition.
10420 This is needed if tsubsting causes an error. */
10432 {
10435 /* Adjust visibility for template arguments. */
10437 }
10443 /* We should never instantiate a nested class before its enclosing
10444 class; we need to look up the nested class by name before we can
10445 instantiate it, and that lookup should instantiate the enclosing
10446 class. */
10452 {
10453 tree pbase_binfo;
10454 tree pushed_scope;
10457 /* We must enter the scope containing the type, as that is where
10458 the accessibility of types named in dependent bases are
10459 looked up from. */
10462 /* Substitute into each of the bases to determine the actual
10463 basetypes. */
10465 {
10466 tree base;
10472 {
10473 expanded_bases =
10480 }
10483 {
10485 /* Extract the already-expanded base class. */
10487 else
10488 /* Substitute to figure out the base class. */
10490 NULL_TREE);
10498 }
10499 }
10501 /* The list is now in reverse order; correct that. */
10506 }
10507 /* Now call xref_basetypes to set up all the base-class
10508 information. */
10516 /* Now that our base classes are set up, enter the scope of the
10517 class, so that name lookups into base classes, etc. will work
10518 correctly. This is precisely analogous to what we do in
10519 begin_class_definition when defining an ordinary non-template
10520 class, except we also need to push the enclosing classes. */
10523 /* Now members are processed in the order of declaration. */
10526 {
10530 {
10532 {
10533 /* Build new CLASSTYPE_NESTED_UTDS. */
10535 tree newtag;
10541 /* If the member is a class template, then -- even after
10542 substitution -- there may be dependent types in the
10543 template argument list for the class. We increment
10544 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10545 that function will assume that no types are dependent
10546 when outside of a template. */
10556 {
10560 /* Unfortunately, lookup_template_class sets
10561 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10562 instantiation (i.e., for the type of a member
10563 template class nested within a template class.)
10564 This behavior is required for
10565 maybe_process_partial_specialization to work
10566 correctly, but is not accurate in this case;
10567 the TAG is not an instantiation of anything.
10568 (The corresponding TEMPLATE_DECL is an
10569 instantiation, but the TYPE is not.) */
10572 /* Now, we call pushtag to put this NEWTAG into the scope of
10573 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10574 pushtag calling push_template_decl. We don't have to do
10575 this for enums because it will already have been done in
10576 tsubst_enum. */
10580 }
10581 }
10583 {
10584 /* Build new TYPE_METHODS. */
10585 tree r;
10594 /* Instantiate members marked with attribute used. */
10600 }
10603 /* A closure type for a lambda in a default argument for a
10604 member template. Ignore it; it will be instantiated with
10606 else
10607 {
10608 /* Build new TYPE_FIELDS. */
10610 {
10611 tree condition;
10614 condition =
10624 }
10626 {
10627 tree r;
10631 /* The file and line for this declaration, to
10632 assist in error message reporting. Since we
10633 called push_tinst_level above, we don't need to
10634 restore these. */
10644 {
10645 /* A capture pack became multiple fields. */
10648 }
10651 {
10655 {
10656 /* In [temp.inst]:
10658 [t]he initialization (and any associated
10659 side-effects) of a static data member does
10660 not occur unless the static data member is
10661 itself used in a way that requires the
10662 definition of the static data member to
10663 exist.
10665 Therefore, we do not substitute into the
10666 initialized for the static data member here. */
10667 finish_static_data_member_decl
10673 /* Instantiate members marked with attribute used. */
10676 }
10678 {
10679 /* Determine whether R has a valid type and can be
10680 completed later. If R is invalid, then its type
10681 is replaced by error_mark_node. */
10687 {
10688 /* If R's type couldn't be completed and
10689 it isn't a flexible array member (whose
10690 type is incomplete by definition) give
10691 an error. */
10694 }
10695 }
10697 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10698 such a thing will already have been added to the field
10699 list by tsubst_enum in finish_member_declaration in the
10700 CLASSTYPE_NESTED_UTDS case above. */
10704 {
10707 }
10708 }
10709 }
10710 }
10711 }
10712 else
10713 {
10716 {
10717 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10723 {
10724 /* template <class T> friend class C; */
10727 }
10729 {
10730 /* template <class T> friend class C::D; */
10736 }
10739 {
10740 /* This could be either
10742 friend class T::C;
10744 when dependent_type_p is false or
10746 template <class U> friend class T::C;
10748 otherwise. */
10749 /* Bump processing_template_decl in case this is something like
10750 template <class T> friend struct A<T>::B. */
10757 }
10760 {
10761 /* friend class C;
10763 where C hasn't been declared yet. Let's lookup name
10764 from namespace scope directly, bypassing any name that
10765 come from dependent base class. */
10768 /* The call to xref_tag_from_type does injection for friend
10769 classes. */
10771 friend_type =
10775 }
10777 /* friend class C<T>; */
10780 /* Otherwise it's
10782 friend class C;
10784 where C is already declared or
10786 friend class C<int>;
10788 We don't have to do anything in these cases. */
10791 /* Trick make_friend_class into realizing that the friend
10792 we're adding is a template, not an ordinary class. It's
10793 important that we use make_friend_class since it will
10794 perform some error-checking and output cross-reference
10795 information. */
10803 }
10804 else
10805 {
10806 /* Build new DECL_FRIENDLIST. */
10807 tree r;
10809 /* The file and line for this declaration, to
10810 assist in error message reporting. Since we
10811 called push_tinst_level above, we don't need to
10812 restore these. */
10816 {
10819 }
10824 {
10827 }
10828 }
10829 }
10830 }
10833 {
10834 /* Restore these before substituting into the lambda capture
10835 initializers. */
10838 }
10841 {
10844 {
10850 {
10851 /* Set function_depth to avoid garbage collection. */
10855 }
10857 /* We need to instantiate the capture list from the template
10858 after we've instantiated the closure members, but before we
10859 consider adding the conversion op. Also keep any captures
10860 that may have been added during instantiation of the op(). */
10862 tree tmpl_cap
10871 }
10872 else
10874 }
10876 /* Set the file and line number information to whatever is given for
10877 the class itself. This puts error messages involving generated
10878 implicit functions at a predictable point, and the same point
10879 that would be used for non-template classes. */
10886 /* We don't instantiate default arguments for member functions. 14.7.1:
10888 The implicit instantiation of a class template specialization causes
10889 the implicit instantiation of the declarations, but not of the
10890 definitions or default arguments, of the class member functions,
10891 member classes, static data members and member templates.... */
10893 /* Some typedefs referenced from within the template code need to be access
10894 checked at template instantiation time, i.e now. These types were
10895 added to the template at parsing time. Let's get those and perform
10896 the access checks then. */
10906 /* The vtable for a template class can be emitted in any translation
10907 unit in which the class is instantiated. When there is no key
10908 method, however, finish_struct_1 will already have added TYPE to
10909 the keyed_classes. */
10914 }
10916 /* Wrapper for instantiate_class_template_1. */
10918 tree
10920 {
10921 tree ret;
10926 }
10928 static tree
10930 {
10931 tree r;
10937 else
10938 {
10945 }
10947 }
10949 /* Given a function parameter pack TMPL_PARM and some function parameters
10950 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10951 and set *SPEC_P to point at the next point in the list. */
10953 tree
10955 {
10956 /* Collect all of the extra "packed" parameters into an
10957 argument pack. */
10958 tree parmvec;
10968 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10974 /* Build the argument packs. */
10979 }
10981 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10982 NONTYPE_ARGUMENT_PACK. */
10984 static tree
10986 {
10988 }
10990 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10991 pack expansion with no extra args, 2 if it has extra args, or 0
10992 if it is not a pack expansion. */
10994 static int
10996 {
11002 /* A decl pack is itself an expansion. */
11009 }
11012 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11014 static tree
11016 {
11023 }
11025 /* This is a subroutine of tsubst_pack_expansion.
11027 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11028 mechanism to store the (non complete list of) arguments of the
11029 substitution and return a non substituted pack expansion, in order
11030 to wait for when we have enough arguments to really perform the
11031 substitution. */
11033 static bool
11037 {
11038 /* If one pack has an expansion and another pack has a normal
11039 argument or if one pack has an empty argument and an another
11040 one hasn't then tsubst_pack_expansion cannot perform the
11041 substitution and need to fall back on the
11042 PACK_EXPANSION_EXTRA mechanism. */
11050 {
11053 parm_pack;
11055 {
11060 /* We can't substitute a pack expansion with extra args into
11061 our pattern. */
11065 else
11067 }
11071 }
11073 }
11075 /* [temp.variadic]/6 says that:
11077 The instantiation of a pack expansion [...]
11078 produces a list E1,E2, ..., En, where N is the number of elements
11079 in the pack expansion parameters.
11081 This subroutine of tsubst_pack_expansion produces one of these Ei.
11083 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11084 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11085 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11086 INDEX is the index 'i' of the element Ei to produce. ARGS,
11087 COMPLAIN, and IN_DECL are the same parameters as for the
11088 tsubst_pack_expansion function.
11090 The function returns the resulting Ei upon successful completion,
11091 or error_mark_node.
11093 Note that this function possibly modifies the ARGS parameter, so
11094 it's the responsibility of the caller to restore it. */
11096 static tree
11098 tree parm_packs,
11100 tree args /* This parm gets
11102 tsubst_flags_t complain,
11103 tree in_decl)
11104 {
11105 tree t;
11108 /* For each parameter pack, change the substitution of the parameter
11109 pack to the ith argument in its argument pack, then expand the
11110 pattern. */
11112 {
11117 ith_elem_is_expansion |=
11120 /* Select the Ith argument from the pack. */
11123 {
11125 {
11130 }
11131 else
11133 }
11134 else
11135 {
11140 {
11142 /* Update the corresponding argument. */
11144 }
11145 else
11146 /* Re-use the ARGUMENT_PACK_SELECT. */
11148 }
11150 }
11152 /* Substitute into the PATTERN with the (possibly altered)
11153 arguments. */
11155 /* Expanding a fixed parameter pack from
11156 coerce_template_parameter_pack. */
11161 {
11164 else
11167 }
11171 else
11174 /* If the Ith argument pack element is a pack expansion, then
11175 the Ith element resulting from the substituting is going to
11176 be a pack expansion as well. */
11181 }
11183 /* When the unexpanded parameter pack in a fold expression expands to an empty
11184 sequence, the value of the expression is as follows; the program is
11185 ill-formed if the operator is not listed in this table.
11187 && true
11188 || false
11189 , void() */
11191 tree
11193 {
11197 {
11206 }
11212 }
11214 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11215 form an expression that combines the two terms using the
11216 operator of T. */
11218 static tree
11220 {
11224 // Handle compound assignment operators.
11229 {
11239 complain);
11240 }
11241 }
11243 /* Substitute ARGS into the pack of a fold expression T. */
11247 {
11249 }
11251 /* Substitute ARGS into the pack of a fold expression T. */
11255 {
11257 }
11259 /* Expand a PACK of arguments into a grouped as left fold.
11260 Given a pack containing elements A0, A1, ..., An and an
11261 operator @, this builds the expression:
11263 ((A0 @ A1) @ A2) ... @ An
11265 Note that PACK must not be empty.
11267 The operator is defined by the original fold expression T. */
11269 static tree
11271 {
11274 {
11277 }
11279 }
11281 /* Substitute into a unary left fold expression. */
11283 static tree
11285 tree in_decl)
11286 {
11291 {
11295 }
11298 else
11300 }
11302 /* Substitute into a binary left fold expression.
11304 Do ths by building a single (non-empty) vector of argumnts and
11305 building the expression from those elements. */
11307 static tree
11309 tree in_decl)
11310 {
11319 {
11324 }
11332 }
11334 /* Expand a PACK of arguments into a grouped as right fold.
11335 Given a pack containing elementns A0, A1, ..., and an
11336 operator @, this builds the expression:
11338 A0@ ... (An-2 @ (An-1 @ An))
11340 Note that PACK must not be empty.
11342 The operator is defined by the original fold expression T. */
11344 tree
11346 {
11347 // Build the expression.
11351 {
11354 }
11356 }
11358 /* Substitute into a unary right fold expression. */
11360 static tree
11362 tree in_decl)
11363 {
11368 {
11372 }
11375 else
11377 }
11379 /* Substitute into a binary right fold expression.
11381 Do ths by building a single (non-empty) vector of arguments and
11382 building the expression from those elements. */
11384 static tree
11386 tree in_decl)
11387 {
11396 {
11401 }
11410 }
11413 /* Substitute ARGS into T, which is an pack expansion
11414 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11415 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11416 (if only a partial substitution could be performed) or
11417 ERROR_MARK_NODE if there was an error. */
11418 tree
11420 tree in_decl)
11421 {
11422 tree pattern;
11426 tree result;
11434 /* Add in any args remembered from an earlier partial instantiation. */
11439 /* Determine the argument packs that will instantiate the parameter
11440 packs used in the expansion expression. While we're at it,
11441 compute the number of arguments to be expanded and make sure it
11442 is consistent. */
11445 {
11452 {
11457 else
11460 }
11462 {
11463 /* ??? Support use in other patterns. */
11467 }
11469 {
11470 /* We know we have correct local_specializations if this
11471 expansion is at function scope, or if we're dealing with a
11472 local parameter in a requires expression; for the latter,
11473 tsubst_requires_expr set it up appropriately. */
11476 else
11477 /* We can't rely on local_specializations for a parameter
11478 name used later in a function declaration (such as in a
11479 late-specified return type). Even if it exists, it might
11480 have the wrong value for a recursive call. */
11484 {
11485 /* This parameter pack was used in an unevaluated context. Just
11486 make a dummy decl, since it's only used for its type. */
11489 /* Partial instantiation of the parm_pack, we can't build
11490 up an argument pack yet. */
11492 else
11494 }
11495 }
11498 else
11499 {
11505 }
11512 /* This can only happen if we forget to expand an argument
11513 pack somewhere else. Just return an error, silently. */
11514 {
11518 }
11521 {
11525 /* Don't bother trying to do a partial substitution with
11526 incomplete packs; we'll try again after deduction. */
11533 {
11538 pattern);
11539 else
11541 pattern);
11543 }
11545 /* Keep track of the parameter packs and their corresponding
11546 argument packs. */
11549 }
11550 else
11551 {
11552 /* We can't substitute for this parameter pack. We use a flag as
11553 well as the missing_level counter because function parameter
11554 packs don't have a level. */
11557 }
11558 }
11560 /* If the expansion is just T..., return the matching argument pack, unless
11561 we need to call convert_from_reference on all the elements. This is an
11562 important optimization; see c++/68422. */
11565 {
11567 /* Types need no adjustment, nor does sizeof..., and if we still have
11568 some pack expansion args we won't do anything yet. */
11573 /* Also optimize expression pack expansions if we can tell that the
11574 elements won't have reference type. */
11580 /* Otherwise use the normal path so we get convert_from_reference. */
11581 }
11583 /* We cannot expand this expansion expression, because we don't have
11584 all of the argument packs we need. */
11586 {
11587 /* We got some full packs, but we can't substitute them in until we
11588 have values for all the packs. So remember these until then. */
11593 }
11595 {
11596 /* There were no real arguments, we're just replacing a parameter
11597 pack with another version of itself. Substitute into the
11598 pattern and return a PACK_EXPANSION_*. The caller will need to
11599 deal with that. */
11603 else
11607 }
11612 {
11613 /* We're in a late-specified return type, so create our own local
11614 specializations map; the current map is either NULL or (in the
11615 case of recursive unification) might have bindings that we don't
11616 want to use or alter. */
11619 }
11621 /* For each argument in each argument pack, substitute into the
11622 pattern. */
11626 {
11628 i,
11630 in_decl);
11633 {
11636 }
11637 }
11639 /* Update ARGS to restore the substitution from parameter packs to
11640 their argument packs. */
11642 {
11648 else
11649 {
11657 /* Update the corresponding argument. */
11661 else
11663 }
11664 }
11667 {
11670 }
11672 /* If the dependent pack arguments were such that we end up with only a
11673 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11679 }
11681 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11682 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11683 parameter packs; all parms generated from a function parameter pack will
11684 have the same DECL_PARM_INDEX. */
11686 tree
11688 {
11690 tree patparm;
11693 {
11699 }
11700 else
11701 {
11706 }
11709 }
11711 /* Make an argument pack out of the TREE_VEC VEC. */
11713 static tree
11715 {
11716 tree pack;
11720 else
11721 {
11724 }
11727 }
11729 /* Return an exact copy of template args T that can be modified
11730 independently. */
11732 static tree
11734 {
11742 {
11747 }
11753 }
11755 /* Substitute ARGS into the vector or list of template arguments T. */
11757 static tree
11759 {
11771 {
11773 tree new_arg;
11778 {
11779 /* Substitute into an expansion expression. */
11783 /* Add to the expanded length adjustment the number of
11784 expanded arguments. We subtract one from this
11785 measurement, because the argument pack expression
11786 itself is already counted as 1 in
11787 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11788 the argument pack is empty. */
11790 }
11792 {
11793 /* Substitute into each of the arguments. */
11802 else
11807 }
11808 else
11817 }
11822 /* Make space for the expanded arguments coming from template
11823 argument packs. */
11825 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11826 arguments for a member template.
11827 In that case each TREE_VEC in ORIG_T represents a level of template
11828 arguments, and ORIG_T won't carry any non defaulted argument count.
11829 It will rather be the nested TREE_VECs that will carry one.
11830 In other words, ORIG_T carries a non defaulted argument count only
11831 if it doesn't contain any nested TREE_VEC. */
11833 {
11837 }
11839 {
11843 {
11846 /* Now expand the template argument pack "in place". */
11849 }
11850 else
11851 {
11853 out++;
11854 }
11855 }
11858 }
11860 /* Substitute ARGS into one level PARMS of template parameters. */
11862 static tree
11864 {
11871 {
11879 }
11882 }
11884 /* Return the result of substituting ARGS into the template parameters
11885 given by PARMS. If there are m levels of ARGS and m + n levels of
11886 PARMS, then the result will contain n levels of PARMS. For
11887 example, if PARMS is `template <class T> template <class U>
11888 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11889 result will be `template <int*, double, class V>'. */
11891 static tree
11893 {
11897 /* When substituting into a template, we must set
11898 PROCESSING_TEMPLATE_DECL as the template parameters may be
11899 dependent if they are based on one-another, and the dependency
11900 predicates are short-circuit outside of templates. */
11907 {
11914 }
11919 }
11921 /* Return the result of substituting ARGS into one template parameter
11922 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11923 parameter and which TREE_PURPOSE is the default argument of the
11924 template parameter. */
11926 static tree
11928 {
11949 }
11951 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11952 type T. If T is not an aggregate or enumeration type, it is
11953 handled as if by tsubst. IN_DECL is as for tsubst. If
11954 ENTERING_SCOPE is nonzero, T is the context for a template which
11955 we are presently tsubst'ing. Return the substituted value. */
11957 static tree
11959 tree args,
11960 tsubst_flags_t complain,
11961 tree in_decl,
11963 {
11968 {
11973 /* Fall through. */
11977 {
11978 tree argvec;
11979 tree context;
11980 tree r;
11984 /* In "sizeof(X<I>)" we need to evaluate "I". */
11990 /* First, determine the context for the type we are looking
11991 up. */
11994 {
11997 /* If context is a nested class inside a class template,
11998 it may still need to be instantiated (c++/33959). */
12000 }
12002 /* Then, figure out what arguments are appropriate for the
12003 type we are trying to find. For example, given:
12005 template <class T> struct S;
12006 template <class T, class U> void f(T, U) { S<U> su; }
12008 and supposing that we are instantiating f<int, double>,
12009 then our ARGS will be {int, double}, but, when looking up
12010 S we only want {double}. */
12015 else
12016 {
12020 }
12026 }
12027 else
12028 /* This is not a template type, so there's nothing to do. */
12033 }
12034 }
12036 /* Substitute into the default argument ARG (a default argument for
12037 FN), which has the indicated TYPE. */
12039 tree
12041 {
12046 /* This can happen in invalid code. */
12050 /* This default argument came from a template. Instantiate the
12051 default argument here, not in tsubst. In the case of
12052 something like:
12054 template <class T>
12055 struct S {
12056 static T t();
12057 void f(T = t());
12058 };
12060 we must be careful to do name lookup in the scope of S<T>,
12061 rather than in the current class. */
12063 /* The "this" pointer is not valid in a default argument. */
12065 {
12070 }
12073 /* The default argument expression may cause implicitly defined
12074 member functions to be synthesized, which will result in garbage
12075 collection. We must treat this situation as if we were within
12076 the body of function so as to avoid collecting live data on the
12077 stack. */
12085 /* Restore the "this" pointer. */
12087 {
12090 }
12097 /* Make sure the default argument is reasonable. */
12103 }
12105 /* Substitute into all the default arguments for FN. */
12107 static void
12109 {
12110 tree arg;
12111 tree tmpl_args;
12115 /* If this function is not yet instantiated, we certainly don't need
12116 its default arguments. */
12119 /* Don't do this again for clones. */
12124 arg;
12130 complain);
12131 }
12133 /* Substitute the ARGS into the T, which is a _DECL. Return the
12134 result of the substitution. Issue error and warning messages under
12135 control of COMPLAIN. */
12137 static tree
12139 {
12140 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12141 location_t saved_loc;
12146 /* Set the filename and linenumber to improve error-reporting. */
12151 {
12153 {
12154 /* We can get here when processing a member function template,
12155 member class template, or template template parameter. */
12157 tree spec;
12158 tree tmpl_args;
12159 tree full_args;
12162 {
12163 /* Template template parameter is treated here. */
12167 /* If we get a real template back, return it. This can happen in
12168 the context of most_specialized_partial_spec. */
12171 else
12172 /* The new TEMPLATE_DECL was built in
12173 reduce_template_parm_level. */
12176 }
12178 /* We might already have an instance of this template.
12179 The ARGS are for the surrounding class type, so the
12180 full args contain the tsubst'd args for the context,
12181 plus the innermost args from the template decl. */
12185 /* Because this is a template, the arguments will still be
12186 dependent, even after substitution. If
12187 PROCESSING_TEMPLATE_DECL is not set, the dependency
12188 predicates will short-circuit. */
12196 /* If this is a default template template argument,
12197 tsubst might not have changed anything. */
12204 {
12207 }
12209 /* Make a new template decl. It will be similar to the
12210 original, but will record the current template arguments.
12211 We also create a new function declaration, which is just
12212 like the old one, but points to this new template, rather
12213 than the old one. */
12218 // Build new template info linking to the original template decl.
12223 {
12224 tree new_type;
12232 /* For a partial specialization, we need to keep pointing to
12233 the primary template. */
12239 }
12240 else
12241 {
12242 tree new_decl;
12254 }
12260 /* The template parameters for this new template are all the
12261 template parameters for the old template, except the
12262 outermost level of parameters. */
12265 complain);
12271 /* Record this non-type partial instantiation. */
12275 }
12279 {
12280 tree ctx;
12283 tree gen_tmpl;
12284 tree type;
12289 /* Nobody should be tsubst'ing into non-template functions. */
12293 {
12294 tree spec;
12296 /* If T is not dependent, just return it. */
12300 /* Calculate the most general template of which R is a
12301 specialization, and the complete set of arguments used to
12302 specialize R. */
12305 (DECL_TEMPLATE_RESULT
12311 /* Check to see if we already have this specialization. */
12316 {
12319 }
12321 /* We can see more levels of arguments than parameters if
12322 there was a specialization of a member template, like
12323 this:
12325 template <class T> struct S { template <class U> void f(); }
12326 template <> template <class U> void S<int>::f(U);
12328 Here, we'll be substituting into the specialization,
12329 because that's where we can find the code we actually
12330 want to generate, but we'll have enough arguments for
12331 the most general template.
12333 We also deal with the peculiar case:
12335 template <class T> struct S {
12336 template <class U> friend void f();
12337 };
12338 template <class U> void f() {}
12339 template S<int>;
12340 template void f<double>();
12342 Here, the ARGS for the instantiation of will be {int,
12343 double}. But, we only need as many ARGS as there are
12344 levels of template parameters in CODE_PATTERN. We are
12345 careful not to get fooled into reducing the ARGS in
12346 situations like:
12348 template <class T> struct S { template <class U> void f(U); }
12349 template <class T> template <> void S<T>::f(int) {}
12351 which we can spot because the pattern will be a
12352 specialization in this case. */
12354 parms_depth =
12359 }
12360 else
12361 {
12362 /* This special case arises when we have something like this:
12364 template <class T> struct S {
12365 friend void f<int>(int, double);
12366 };
12368 Here, the DECL_TI_TEMPLATE for the friend declaration
12369 will be an IDENTIFIER_NODE. We are being called from
12370 tsubst_friend_function, and we want only to create a
12371 new decl (R) with appropriate types so that we can call
12372 determine_specialization. */
12374 }
12377 {
12380 else
12384 }
12385 else
12386 {
12389 }
12394 /* If we hit excessive deduction depth, the type is bogus even if
12395 it isn't error_mark_node, so don't build a decl. */
12399 /* We do NOT check for matching decls pushed separately at this
12400 point, as they may not represent instantiations of this
12401 template, and in any case are considered separate under the
12402 discrete model. */
12406 /* Clear out the mangled name and RTL for the instantiation. */
12409 /* Leave DECL_INITIAL set on deleted instantiations. */
12414 /* OpenMP UDRs have the only argument a reference to the declared
12415 type. We want to diagnose if the declared type is a reference,
12416 which is invalid, but as references to references are usually
12417 quietly merged, diagnose it here. */
12419 {
12420 tree argtype
12425 "reference type %qT in "
12429 argtype);
12430 }
12433 /* Type-conversion operator. Reconstruct the name, in
12434 case it's the name of one of the template's parameters. */
12444 /* If this is an instantiation of a function with internal
12445 linkage, we already know what object file linkage will be
12446 assigned to the instantiation. */
12455 /* We'll re-clone as appropriate in instantiate_template. */
12458 /* If we aren't complaining now, return on error before we register
12459 the specialization so that we'll complain eventually. */
12465 /* When instantiating a constrained member, substitute
12466 into the constraints to create a new constraint. */
12469 {
12472 }
12474 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12475 this in the special friend case mentioned above where
12476 GEN_TMPL is NULL. */
12478 {
12483 tree new_r
12486 /* We instantiated this while substituting into
12487 the type earlier (template/friend54.C). */
12490 /* We're not supposed to instantiate default arguments
12491 until they are called, for a template. But, for a
12492 declaration like:
12494 template <class T> void f ()
12495 { extern void g(int i = T()); }
12497 we should do the substitution when the template is
12498 instantiated. We handle the member function case in
12499 instantiate_class_template since the default arguments
12500 might refer to other members of the class. */
12505 }
12506 else
12509 /* Copy the list of befriending classes. */
12513 {
12517 in_decl);
12518 }
12521 {
12525 /* If this is an instantiation of a member template, clone it.
12526 If it isn't, that'll be handled by
12527 clone_constructors_and_destructors. */
12530 }
12541 /* Possibly limit visibility based on template args. */
12544 {
12548 }
12556 }
12560 {
12568 {
12569 /* If there is a local specialization that isn't a
12570 parameter pack, it means that we're doing a "simple"
12571 substitution from inside tsubst_pack_expansion. Just
12572 return the local specialization (which will be a single
12573 parm). */
12580 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12581 the parameters in this function parameter pack. */
12585 {
12588 /* Zero-length parameter packs are boring. Just substitute
12589 into the chain. */
12593 }
12594 else
12595 {
12596 /* All we did was update the type. Make a note of that. */
12599 }
12600 }
12602 /* Loop through all of the parameters we'll build. When T is
12603 a function parameter pack, LEN is the number of expanded
12604 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12607 {
12614 /* We're on the Ith parameter of the function parameter
12615 pack. */
12616 {
12617 /* Get the Ith type. */
12620 /* Rename the parameter to include the index. */
12623 }
12625 /* We're dealing with a normal parameter. */
12633 {
12636 else
12639 }
12649 /* Keep track of the first new parameter we
12650 generate. That's what will be returned to the
12651 caller. */
12655 /* Build a proper chain of parameters when substituting
12656 into a function parameter pack. */
12659 }
12661 /* If cp_unevaluated_operand is set, we're just looking for a
12662 single dummy parameter, so don't keep going. */
12667 /* FIRST_R contains the start of the chain we've built. */
12669 }
12673 {
12680 {
12681 /* This field is a lambda capture pack. Return a TREE_VEC of
12682 the expanded fields to instantiate_class_template_1 and
12683 store them in the specializations hash table as a
12684 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12688 {
12691 }
12692 else
12693 {
12694 /* All we did was update the type. Make a note of that. */
12697 }
12698 }
12701 {
12704 {
12708 }
12718 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12719 non-bit-fields DECL_INITIAL is a non-static data member
12720 initializer, which gets deferred instantiation. */
12726 {
12727 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12728 NSDMI in perform_member_init. Still set DECL_INITIAL
12729 so that we know there is one. */
12734 }
12735 /* We don't have to set DECL_CONTEXT here; it is set by
12736 finish_member_declaration. */
12744 }
12747 {
12752 }
12753 }
12757 /* We reach here only for member using decls. We also need to check
12758 uses_template_parms because DECL_DEPENDENT_P is not set for a
12759 using-declaration that designates a member of the current
12760 instantiation (c++/53549). */
12763 {
12767 {
12772 {
12776 {
12779 }
12780 else
12781 {
12784 }
12786 }
12787 }
12788 else
12789 {
12795 else
12796 {
12799 }
12800 }
12801 }
12802 else
12803 {
12806 }
12811 {
12814 tree spec;
12816 tree ctx;
12825 {
12826 /* If this is the canonical decl, we don't have to
12827 mess with instantiations, and often we can't (for
12828 typename, template type parms and such). Note that
12829 TYPE_NAME is not correct for the above test if
12830 we've copied the type for a typedef. */
12836 }
12838 /* Check to see if we already have the specialization we
12839 need. */
12842 {
12843 /* T is a static data member or namespace-scope entity.
12844 We have to substitute into namespace-scope variables
12845 (not just variable templates) because of cases like:
12847 template <class T> void f() { extern T t; }
12849 where the entity referenced is not known until
12850 instantiation time. */
12854 {
12856 complain,
12858 /* If CTX is unchanged, then T is in fact the
12859 specialization we want. That situation occurs when
12860 referencing a static data member within in its own
12861 class. We can use pointer equality, rather than
12862 same_type_p, because DECL_CONTEXT is always
12863 canonical... */
12865 /* ... unless T is a member template; in which
12866 case our caller can be willing to create a
12867 specialization of that template represented
12868 by T. */
12872 }
12875 {
12880 argvec = (coerce_innermost_template_parms
12888 }
12889 }
12890 else
12891 {
12892 /* A local variable. */
12894 /* Subsequent calls to pushdecl will fill this in. */
12896 /* Unless this is a reference to a static variable from an
12897 enclosing function, in which case we need to fill it in now. */
12899 {
12903 }
12905 }
12906 /* If we already have the specialization we need, there is
12907 nothing more to do. */
12909 {
12912 }
12914 /* Create a new node for the specialization we need. */
12917 {
12920 else
12927 }
12929 {
12930 /* Even if the original location is out of scope, the
12931 newly substituted one is not. */
12938 {
12939 /* It may seem that this case cannot occur, since:
12941 typedef void f();
12942 void g() { f x; }
12944 declares a function, not a variable. However:
12946 typedef void f();
12947 template <typename T> void g() { T t; }
12948 template void g<f>();
12950 is an attempt to declare a variable with function
12951 type. */
12953 /* R is not yet sufficiently initialized, so we
12954 just use its name. */
12957 }
12959 /* Wait until cp_finish_decl to set this again, to handle
12960 circular dependency (template/instantiate6.C). */
12965 {
12970 {
12973 }
12975 }
12979 }
12985 /* Clear out the mangled name and RTL for the instantiation. */
12989 /* The initializer must not be expanded until it is required;
12990 see [temp.inst]. */
12994 {
12997 /* Possibly limit visibility based on template args. */
13000 {
13004 }
13006 }
13009 {
13010 /* A static data member declaration is always marked
13011 external when it is declared in-class, even if an
13012 initializer is present. We mimic the non-template
13013 processing here. */
13021 }
13022 else
13023 {
13028 }
13036 /* Preserve a typedef that names a type. */
13038 {
13042 /* An alias template specialization can be dependent
13043 even if its underlying type is not. */
13045 }
13048 }
13053 }
13054 #undef RETURN
13056 out:
13057 /* Restore the file and line information. */
13061 }
13063 /* Substitute into the ARG_TYPES of a function type.
13064 If END is a TREE_CHAIN, leave it and any following types
13065 un-substituted. */
13067 static tree
13069 tree args,
13070 tree end,
13071 tsubst_flags_t complain,
13072 tree in_decl)
13073 {
13074 tree remaining_arg_types;
13078 tree default_arg;
13089 {
13090 /* For a pack expansion, perform substitution on the
13091 entire expression. Later on, we'll handle the arguments
13092 one-by-one. */
13097 /* So that we'll spin through the parameters, one by one. */
13099 else
13100 {
13101 /* We only partially substituted into the parameter
13102 pack. Our type is TYPE_PACK_EXPANSION. */
13105 }
13106 }
13119 {
13121 {
13125 }
13127 }
13128 /* DR 657. */
13132 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13133 top-level qualifiers as required. */
13136 /* We do not substitute into default arguments here. The standard
13137 mandates that they be instantiated only when needed, which is
13138 done in build_over_call. */
13142 {
13143 /* We've instantiated a template before its default arguments
13144 have been parsed. This can happen for a nested template
13145 class, and is not an error unless we require the default
13146 argument in a call of this function. */
13147 remaining_arg_types =
13150 }
13151 else
13152 remaining_arg_types =
13154 }
13157 }
13159 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13160 *not* handle the exception-specification for FNTYPE, because the
13161 initial substitution of explicitly provided template parameters
13162 during argument deduction forbids substitution into the
13163 exception-specification:
13165 [temp.deduct]
13167 All references in the function type of the function template to the
13168 corresponding template parameters are replaced by the specified tem-
13169 plate argument values. If a substitution in a template parameter or
13170 in the function type of the function template results in an invalid
13171 type, type deduction fails. [Note: The equivalent substitution in
13172 exception specifications is done only when the function is instanti-
13173 ated, at which point a program is ill-formed if the substitution
13174 results in an invalid type.] */
13176 static tree
13178 tree args,
13179 tsubst_flags_t complain,
13180 tree in_decl)
13181 {
13182 tree return_type;
13184 tree fntype;
13186 /* The TYPE_CONTEXT is not used for function/method types. */
13189 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13190 failure. */
13194 {
13195 /* Substitute the argument types. */
13207 {
13208 /* DR 1207: 'this' is in scope in the trailing return type. */
13210 }
13212 /* Substitute the return type. */
13216 {
13219 }
13220 }
13221 else
13222 /* Substitute the return type. */
13227 /* DR 486 clarifies that creation of a function type with an
13228 invalid return type is a deduction failure. */
13231 {
13233 {
13236 else
13238 }
13240 }
13241 /* And DR 657. */
13246 {
13247 /* Substitute the argument types. */
13252 }
13254 /* Construct a new type node and return it. */
13256 {
13261 }
13262 else
13263 {
13265 /* Don't pick up extra function qualifiers from the basetype. */
13268 {
13269 /* [temp.deduct]
13271 Type deduction may fail for any of the following
13272 reasons:
13274 -- Attempting to create "pointer to member of T" when T
13275 is not a class type. */
13278 r);
13280 }
13285 }
13292 }
13294 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13295 ARGS into that specification, and return the substituted
13296 specification. If there is no specification, return NULL_TREE. */
13298 static tree
13300 tree args,
13301 tsubst_flags_t complain,
13302 tree in_decl,
13304 {
13305 tree specs;
13306 tree new_specs;
13311 {
13312 /* A noexcept-specifier. */
13317 {
13318 /* Defer instantiation of noexcept-specifiers to avoid
13319 excessive instantiations (c++/49107). */
13322 {
13323 /* We already partially instantiated this member template,
13324 so combine the new args with the old. */
13329 }
13330 else
13331 {
13334 }
13335 }
13336 else
13337 new_specs = tsubst_copy_and_build
13341 }
13343 {
13346 else
13348 {
13349 tree spec;
13354 {
13355 /* Expand the pack expansion type. */
13358 in_decl);
13364 else
13365 {
13366 /* We're substituting into a member template, so
13367 we got a TYPE_PACK_EXPANSION back. Add that
13368 expansion and move on. */
13372 expanded_specs,
13373 complain);
13376 }
13377 }
13380 {
13383 else
13388 complain);
13389 }
13392 }
13393 }
13395 }
13397 /* Take the tree structure T and replace template parameters used
13398 therein with the argument vector ARGS. IN_DECL is an associated
13399 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13400 Issue error and warning messages under control of COMPLAIN. Note
13401 that we must be relatively non-tolerant of extensions here, in
13402 order to preserve conformance; if we allow substitutions that
13403 should not be allowed, we may allow argument deductions that should
13404 not succeed, and therefore report ambiguous overload situations
13405 where there are none. In theory, we could allow the substitution,
13406 but indicate that it should have failed, and allow our caller to
13407 make sure that the right thing happens, but we don't try to do this
13408 yet.
13410 This function is used for dealing with types, decls and the like;
13411 for expressions, use tsubst_expr or tsubst_copy. */
13413 tree
13415 {
13438 else
13443 /* Reuse typedefs. We need to do this to handle dependent attributes,
13444 such as attribute aligned. */
13447 {
13451 {
13452 /* DECL represents an alias template and we want to
13453 instantiate it. */
13457 }
13461 {
13465 }
13470 else
13471 /* The typedef is from a non-template context. */
13475 {
13477 r = cp_build_qualified_type_real
13481 }
13482 else
13483 {
13484 /* We don't have an instantiation yet, so drop the typedef. */
13489 }
13490 }
13507 {
13533 {
13539 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13540 needed. */
13546 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13547 with TREE_SIDE_EFFECTS that indicates this is not an integral
13548 constant expression. */
13551 {
13554 }
13557 }
13563 {
13569 /* Early in template argument deduction substitution, we don't
13570 want to reduce the level of 'auto', or it will be confused
13571 with a normal template parm in subsequent deduction. */
13583 {
13587 {
13588 /* See through ARGUMENT_PACK_SELECT arguments. */
13590 /* If the selected argument is an expansion E, that most
13591 likely means we were called from
13592 gen_elem_of_pack_expansion_instantiation during the
13593 substituting of pack an argument pack (which Ith
13594 element is a pack expansion, where I is
13595 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13596 In this case, the Ith element resulting from this
13597 substituting is going to be a pack expansion, which
13598 pattern is the pattern of E. Let's return the
13599 pattern of E, and
13600 gen_elem_of_pack_expansion_instantiation will
13601 build the resulting pack expansion from it. */
13603 {
13604 /* Make sure we aren't throwing away arg info. */
13607 }
13608 }
13609 }
13614 {
13616 /* If ARG is an argument pack, we don't actually want to
13617 perform a substitution here, because substitutions
13618 for argument packs are only done
13619 element-by-element. We can get to this point when
13620 substituting the type of a non-type template
13621 parameter pack, when that type actually contains
13622 template parameter packs from an outer template, e.g.,
13624 template<typename... Types> struct A {
13625 template<Types... Values> struct B { };
13626 }; */
13630 {
13636 return cp_build_qualified_type_real
13638 }
13640 {
13641 /* We are processing a type constructed from a
13642 template template parameter. */
13653 /* Consider this code:
13655 template <template <class> class Template>
13656 struct Internal {
13657 template <class Arg> using Bind = Template<Arg>;
13658 };
13660 template <template <class> class Template, class Arg>
13661 using Instantiate = Template<Arg>; //#0
13663 template <template <class> class Template,
13664 class Argument>
13665 using Bind =
13666 Instantiate<Internal<Template>::template Bind,
13667 Argument>; //#1
13669 When #1 is parsed, the
13670 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13671 parameter `Template' in #0 matches the
13672 UNBOUND_CLASS_TEMPLATE representing the argument
13673 `Internal<Template>::template Bind'; We then want
13674 to assemble the type `Bind<Argument>' that can't
13675 be fully created right now, because
13676 `Internal<Template>' not being complete, the Bind
13677 template cannot be looked up in that context. So
13678 we need to "store" `Bind<Argument>' for later
13679 when the context of Bind becomes complete. Let's
13680 store that in a TYPENAME_TYPE. */
13684 argvec),
13685 typename_type,
13686 complain);
13688 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13689 are resolving nested-types in the signature of a
13690 member function templates. Otherwise ARG is a
13691 TEMPLATE_DECL and is the real template to be
13692 instantiated. */
13700 complain);
13701 return cp_build_qualified_type_real
13703 }
13706 else
13707 /* TEMPLATE_PARM_INDEX. */
13709 }
13712 /* This can happen during the attempted tsubst'ing in
13713 unify. This means that we don't yet have any information
13714 about the template parameter in question. */
13717 /* If we get here, we must have been looking at a parm for a
13718 more deeply nested template. Make a new version of this
13719 template parameter, but with a lower level. */
13721 {
13726 {
13728 r = cp_build_qualified_type_real
13732 }
13739 /* Break infinite recursion when substituting the constraints
13741 else
13742 {
13753 {
13754 /* Propagate constraints on placeholders. */
13759 {
13763 }
13764 }
13767 /* We have reduced the level of the template
13768 template parameter, but not the levels of its
13769 template parameters, so canonical_type_parameter
13770 will not be able to find the canonical template
13771 template parameter for this level. Thus, we
13772 require structural equality checking to compare
13773 TEMPLATE_TEMPLATE_PARMs. */
13777 else
13781 {
13783 /* We might need to substitute into the types of non-type
13784 template parameters. */
13796 }
13797 }
13801 /* OK, now substitute the type of the non-type parameter. We
13802 couldn't do it earlier because it might be an auto parameter,
13803 and we wouldn't need to if we had an argument. */
13810 }
13813 }
13816 {
13824 {
13828 }
13831 {
13835 }
13838 {
13842 }
13848 }
13851 /* We should never be tsubsting a binfo. */
13855 /* A vector of template arguments. */
13861 {
13865 /* [temp.deduct]
13867 Type deduction may fail for any of the following
13868 reasons:
13870 -- Attempting to create a pointer to reference type.
13871 -- Attempting to create a reference to a reference type or
13872 a reference to void.
13874 Core issue 106 says that creating a reference to a reference
13875 during instantiation is no longer a cause for failure. We
13876 only enforce this check in strict C++98 mode. */
13880 {
13883 /* We keep track of the last time we issued this error
13884 message to avoid spewing a ton of messages during a
13885 single bad template instantiation. */
13888 {
13893 else
13896 }
13899 }
13903 {
13905 {
13908 type);
13909 else
13911 type);
13912 }
13914 }
13916 {
13920 }
13922 /* In C++0x, during template argument substitution, when there is an
13923 attempt to create a reference to a reference type, reference
13924 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13926 "If a template-argument for a template-parameter T names a type
13927 that is a reference to a type A, an attempt to create the type
13928 'lvalue reference to cv T' creates the type 'lvalue reference to
13929 A,' while an attempt to create the type type rvalue reference to
13930 cv T' creates the type T"
13931 */
13932 r = cp_build_reference_type
13935 else
13940 /* Will this ever be needed for TYPE_..._TO values? */
13944 }
13946 {
13949 {
13950 /* [temp.deduct]
13952 Type deduction may fail for any of the following
13953 reasons:
13955 -- Attempting to create "pointer to member of T" when T
13956 is not a class type. */
13960 }
13962 {
13966 }
13968 {
13972 }
13975 {
13976 /* The type of the implicit object parameter gets its
13977 cv-qualifiers from the FUNCTION_TYPE. */
13978 tree memptr;
13979 tree method_type
13984 complain);
13985 }
13986 else
13989 complain);
13990 }
13993 {
13994 tree fntype;
13995 tree specs;
14000 /* Substitute the exception specification. */
14008 }
14010 {
14015 /* As an optimization, we avoid regenerating the array type if
14016 it will obviously be the same as T. */
14020 /* These checks should match the ones in create_array_type_for_decl.
14022 [temp.deduct]
14024 The deduction may fail for any of the following reasons:
14026 -- Attempting to create an array with an element type that
14027 is void, a function type, or a reference type, or [DR337]
14028 an abstract class type. */
14034 {
14038 }
14046 {
14049 }
14052 }
14055 {
14067 {
14071 }
14073 {
14074 /* Normally, make_typename_type does not require that the CTX
14075 have complete type in order to allow things like:
14077 template <class T> struct S { typename S<T>::X Y; };
14079 But, such constructs have already been resolved by this
14080 point, so here CTX really should have complete type, unless
14081 it's a partial instantiation. */
14084 {
14088 }
14089 }
14096 {
14099 }
14102 {
14104 {
14108 else
14110 }
14112 {
14116 else
14118 }
14119 }
14121 return cp_build_qualified_type_real
14123 }
14126 {
14138 }
14141 {
14142 tree type;
14158 complain);
14159 }
14162 {
14163 tree type;
14174 {
14176 {
14180 }
14183 }
14194 else
14195 {
14199 /* In a template ~id could be either a complement expression
14200 or an unqualified-id naming a destructor; if instantiating
14201 it produces an expression, it's not an id-expression or
14202 member access. */
14205 }
14210 }
14213 {
14217 }
14221 {
14222 tree r;
14226 else
14234 }
14249 /* We should use one of the expression tsubsts for these codes. */
14255 }
14256 }
14258 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14259 expression on the left-hand side of the "." or "->" operator. A
14260 baselink indicates a function from a base class. Both the
14261 BASELINK_ACCESS_BINFO and the base class referenced may indicate
14262 bases of the template class, rather than the instantiated class.
14263 In addition, lookups that were not ambiguous before may be
14264 ambiguous now. Therefore, we perform the lookup again. */
14266 static tree
14269 {
14282 {
14289 }
14297 {
14302 }
14304 /* If lookup found a single function, mark it as used at this point.
14305 (If it lookup found multiple functions the one selected later by
14306 overload resolution will be marked as used at that point.) */
14314 {
14315 /* Add back the template arguments, if present. */
14321 /* Update the conversion operator type. */
14323 }
14329 {
14331 qualifying_scope,
14332 object_type);
14334 /* We need to call adjust_result_of_qualified_name_lookup in case the
14335 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14336 so that we still get virtual function binding. */
14338 }
14341 }
14343 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14344 true if the qualified-id will be a postfix-expression in-and-of
14345 itself; false if more of the postfix-expression follows the
14346 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14347 of "&". */
14349 static tree
14353 {
14354 tree expr;
14355 tree scope;
14356 tree name;
14358 tree template_args;
14363 /* Figure out what name to look up. */
14366 {
14376 }
14377 else
14378 {
14381 }
14383 /* Substitute into the qualifying scope. When there are no ARGS, we
14384 are just trying to simplify a non-dependent expression. In that
14385 case the qualifying scope may be dependent, and, in any case,
14386 substituting will not help. */
14389 {
14392 }
14393 else
14397 {
14404 }
14407 {
14409 {
14410 /* A BIT_NOT_EXPR is used to represent a destructor. */
14412 {
14416 }
14417 else
14420 }
14421 else
14425 {
14427 {
14431 }
14433 }
14434 }
14437 {
14439 scope);
14440 /* Remember that there was a reference to this entity. */
14443 }
14446 {
14452 }
14455 {
14458 complain);
14459 else
14461 }
14467 {
14468 expr = (adjust_result_of_qualified_name_lookup
14470 expr = (finish_qualified_id_expr
14474 }
14476 /* Expressions do not generally have reference type. */
14478 /* However, if we're about to form a pointer-to-member, we just
14479 want the referenced member referenced. */
14487 }
14489 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14490 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14491 for tsubst. */
14493 static tree
14496 {
14503 {
14504 /* If we had an initializer but it
14505 instantiated to nothing,
14506 value-initialize the object. This will
14507 only occur when the initializer was a
14508 pack expansion where the parameter packs
14509 used in that expansion were of length
14510 zero. */
14512 complain);
14517 }
14520 }
14522 /* Like tsubst, but deals with expressions. This function just replaces
14523 template parms; to finish processing the resultant expression, use
14524 tsubst_copy_and_build or tsubst_expr. */
14526 static tree
14528 {
14530 tree r;
14538 {
14543 {
14544 /* We get here for a use of 'this' in an NSDMI as part of a
14545 constructor call or as part of an aggregate initialization. */
14547 && ((current_function_decl
14549 || (current_class_ref
14553 /* This can happen for a parameter name used later in a function
14554 declaration (such as in a late-specified return type). Just
14555 make a dummy decl, since it's only used for its type. */
14558 /* Give it the template pattern as its context; its true context
14559 hasn't been instantiated yet and this is good enough for
14560 mangling. */
14562 }
14571 {
14572 tree enum_type;
14573 tree v;
14577 /* There is no need to substitute into namespace-scope
14578 enumerators. */
14581 /* If ARGS is NULL, then T is known to be non-dependent. */
14585 /* Unfortunately, we cannot just call lookup_name here.
14586 Consider:
14588 template <int I> int f() {
14589 enum E { a = I };
14590 struct S { void g() { E e = a; } };
14591 };
14593 When we instantiate f<7>::S::g(), say, lookup_name is not
14594 clever enough to find f<7>::a. */
14595 enum_type
14605 /* We didn't find the name. That should never happen; if
14606 name-lookup found it during preliminary parsing, we
14607 should find it again here during instantiation. */
14609 }
14614 {
14615 /* Check for a local specialization set up by
14616 tsubst_pack_expansion. */
14618 {
14622 }
14624 /* When retrieving a capture pack from a generic lambda, remove the
14625 lambda call op's own template argument list from ARGS. Only the
14626 template arguments active for the closure type should be used to
14627 retrieve the pack specialization. */
14633 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14634 tsubst_decl put in the hash table. */
14636 }
14639 {
14640 tree ctx;
14645 {
14648 {
14652 }
14654 }
14655 }
14665 {
14668 {
14669 /* First try name lookup to find the instantiation. */
14672 {
14673 /* Make sure that the one we found is the one we want. */
14679 }
14683 else
14684 {
14685 /* This can happen for a variable used in a
14686 late-specified return type of a local lambda, or for a
14687 local static or constant. Building a new VAR_DECL
14688 should be OK in all those cases. */
14691 /* Avoid infinite recursion (79640). */
14694 {
14695 /* We can't call cp_finish_decl, so handle the
14696 initializer by hand. */
14707 }
14714 }
14715 /* Remember this for subsequent uses. */
14718 }
14719 }
14720 else
14730 /* An OVERLOAD will always be a non-dependent overload set; an
14731 overload set from function scope will just be represented with an
14732 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14734 /* We must have marked any lookups as persistent. */
14750 {
14751 /* Template template argument like the following example need
14752 special treatment:
14754 template <template <class> class TT> struct C {};
14755 template <class T> struct D {
14756 template <class U> struct E {};
14757 C<E> c; // #1
14758 };
14759 D<int> d; // #2
14761 We are processing the template argument `E' in #1 for
14762 the template instantiation #2. Originally, `E' is a
14763 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14764 have to substitute this with one having context `D<int>'. */
14768 {
14769 /* When rewriting a constructor into a deduction guide, a
14770 non-dependent name can become dependent, so memtmpl<args>
14771 becomes context::template memtmpl<args>. */
14775 }
14777 }
14778 else
14779 /* Ordinary template template argument. */
14790 {
14794 }
14799 {
14808 /* We only want to compute the number of arguments. */
14811 else
14818 {
14820 /* Set TREE_USED for the benefit of -Wunused. */
14824 }
14832 {
14837 else
14843 else
14846 }
14847 else
14849 }
14851 {
14859 }
14860 /* Fall through */
14876 {
14880 }
14883 {
14884 tree object;
14885 tree name;
14890 {
14894 }
14897 {
14907 }
14912 in_decl);
14913 else
14916 }
14954 {
14958 }
14961 {
14966 }
14969 {
14973 }
14976 {
14984 }
14990 {
14997 }
15000 {
15007 }
15010 {
15017 }
15020 {
15021 /* Substituted template arguments */
15030 }
15033 {
15053 }
15078 /* Fall through. */
15081 {
15084 }
15085 else
15089 /* This is handled by tsubst_copy_and_build. */
15093 {
15097 }
15100 /* We shouldn't have built any of these during initial template
15101 generation. Instead, they should be built during instantiation
15102 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15106 {
15116 }
15134 {
15135 /* Instantiate any typedefs in the type. */
15140 }
15143 /* These can sometimes show up in a partial instantiation, but never
15144 involve template parms. */
15158 /* We shouldn't get here, but keep going if !flag_checking. */
15162 }
15163 }
15165 /* Helper function for tsubst_omp_clauses, used for instantiation of
15166 OMP_CLAUSE_DECL of clauses. */
15168 static tree
15170 tree in_decl)
15171 {
15175 /* Handle an OpenMP array section represented as a TREE_LIST (or
15176 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15177 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15178 TREE_LIST. We can handle it exactly the same as an array section
15179 (purpose, value, and a chain), even though the nomenclature
15180 (low_bound, length, etc) is different. */
15182 {
15183 tree low_bound
15189 in_decl);
15198 }
15201 /* Undo convert_from_reference tsubst_expr could have called. */
15207 }
15209 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15211 static tree
15214 {
15219 {
15225 {
15228 {
15234 }
15235 /* FALLTHRU */
15250 in_decl);
15282 {
15285 {
15292 }
15293 else
15295 }
15298 in_decl);
15304 in_decl);
15312 in_decl);
15314 {
15317 }
15322 else
15325 in_decl,
15349 }
15352 {
15362 /* tsubst_expr on SCOPE_REF results in returning
15363 finish_non_static_data_member result. Undo that here. */
15367 {
15372 {
15376 CASE_CONVERT:
15385 /* FALLTHRU */
15389 }
15390 }
15396 {
15399 {
15402 }
15403 }
15407 }
15408 }
15412 {
15417 {
15420 }
15421 }
15423 }
15425 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15427 static tree
15429 tree in_decl)
15430 {
15431 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15451 {
15454 else
15455 {
15459 }
15460 }
15465 #undef RECUR
15466 }
15468 /* Used to temporarily communicate the list of #pragma omp parallel
15469 clauses to #pragma omp for instantiation if they are combined
15470 together. */
15474 /* Substitute one OMP_FOR iterator. */
15476 static void
15481 {
15482 #define RECUR(NODE) \
15483 tsubst_expr ((NODE), args, complain, in_decl, \
15484 integral_constant_expression_p)
15491 {
15494 }
15500 {
15501 /* We need to jump through some hoops to handle declarations in the
15502 init-statement, since we might need to handle auto deduction,
15503 but we need to keep control of initialization. */
15507 }
15508 else
15509 {
15511 {
15514 {
15518 {
15522 CASE_CONVERT:
15530 {
15533 }
15534 /* FALLTHRU */
15538 }
15539 }
15540 }
15541 else
15543 }
15554 {
15556 {
15557 /* Declare the variable, but don't let that initialize it. */
15562 }
15567 {
15572 }
15573 else
15580 }
15583 {
15584 /* Declare and initialize the variable. */
15587 }
15589 {
15593 {
15595 {
15601 {
15604 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15609 }
15612 {
15614 decl);
15616 }
15619 {
15621 decl);
15623 }
15624 else
15626 }
15629 }
15631 {
15636 {
15639 }
15640 }
15641 }
15644 {
15648 }
15649 else
15653 {
15664 {
15672 }
15673 else
15679 {
15685 }
15689 {
15697 }
15698 else
15704 }
15710 #undef RECUR
15711 }
15713 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15714 of OMP_TARGET's body. */
15716 static tree
15718 {
15721 {
15730 }
15732 }
15734 /* Helper function for tsubst_expr. For decomposition declaration
15735 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15736 also the corresponding decls representing the identifiers
15737 of the decomposition declaration. Return DECL if successful
15738 or error_mark_node otherwise, set *FIRST to the first decl
15739 in the list chained through DECL_CHAIN and *CNT to the number
15740 of such decls. */
15742 static tree
15746 {
15751 decl2
15756 {
15758 {
15761 }
15778 {
15781 }
15782 else
15784 }
15787 }
15789 /* Like tsubst_copy for expressions, etc. but also does semantic
15790 processing. */
15792 tree
15795 {
15796 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15797 #define RECUR(NODE) \
15798 tsubst_expr ((NODE), args, complain, in_decl, \
15799 integral_constant_expression_p)
15802 tree r;
15803 location_t loc;
15815 {
15817 {
15818 tree_stmt_iterator i;
15822 }
15837 else
15847 {
15849 tree init;
15855 {
15865 else
15867 }
15869 {
15870 /* Don't build up decls for a variadic capture proxy, we'll
15871 instantiate the elements directly as needed. */
15873 }
15874 else
15875 {
15879 {
15880 /* By marking the declaration as instantiated, we avoid
15881 trying to instantiate it. Since instantiate_decl can't
15882 handle local variables, and since we've already done
15883 all that needs to be done, that's the right thing to
15884 do. */
15889 /* Anonymous aggregates are a special case. */
15892 {
15895 {
15899 }
15901 }
15907 {
15912 }
15913 else
15914 {
15919 {
15920 /* For __PRETTY_FUNCTION__ we have to adjust the
15921 initializer. */
15925 }
15926 else
15930 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15936 {
15938 tree first;
15944 }
15945 }
15946 }
15947 }
15950 }
15965 {
15973 {
15975 tree first;
15980 }
15981 else
15986 }
16012 else
16013 {
16020 }
16026 {
16035 }
16043 else
16051 else
16072 {
16079 }
16083 {
16085 tree label;
16092 }
16098 /* Computed goto's must be tsubst'd into. On the other hand,
16099 non-computed gotos must not be; the identifier in question
16100 will have no binding. */
16102 else
16108 {
16124 }
16129 {
16134 }
16135 else
16136 {
16141 else
16148 else
16154 else
16156 }
16160 {
16164 {
16166 /* Prevent instantiate_decl from trying to instantiate
16167 this variable. We've already done all that needs to be
16168 done. */
16171 }
16176 }
16182 {
16183 /* Local classes are not independent templates; they are
16184 instantiated along with their containing function. And this
16185 way we don't have to deal with pushing out of one local class
16186 to instantiate a member of another local class. */
16187 tree fn;
16188 /* Closures are handled by the LAMBDA_EXPR. */
16195 }
16199 {
16200 tree condition;
16203 condition =
16205 args,
16214 }
16220 in_decl);
16257 {
16272 in_decl);
16274 {
16281 }
16293 integral_constant_expression_p);
16304 else
16305 {
16313 }
16317 }
16322 /* FALLTHRU */
16329 in_decl);
16346 in_decl);
16357 {
16360 {
16361 /* For combined target teams, ensure the num_teams and
16362 thread_limit clause expressions are evaluated on the host,
16363 before entering the target construct. */
16364 tree c;
16370 {
16379 OMP_CLAUSE_FIRSTPRIVATE);
16383 }
16384 }
16385 }
16445 {
16450 {
16453 }
16459 }
16460 else
16461 {
16468 {
16471 }
16474 {
16479 {
16482 }
16488 }
16489 else
16490 {
16494 }
16497 }
16501 {
16507 {
16511 {
16516 }
16520 }
16521 else
16522 {
16527 }
16528 }
16532 {
16536 }
16556 /* If the first operand was a statement, we're done with it. */
16560 complain));
16572 integral_constant_expression_p));
16573 }
16576 out:
16579 #undef RECUR
16580 #undef RETURN
16581 }
16583 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16584 function. For description of the body see comment above
16585 cp_parser_omp_declare_reduction_exprs. */
16587 static void
16589 {
16595 tree_stmt_iterator tsi;
16606 {
16625 }
16627 {
16647 }
16648 }
16650 /* T is a postfix-expression that is not being used in a function
16651 call. Return the substituted version of T. */
16653 static tree
16655 tsubst_flags_t complain,
16656 tree in_decl)
16657 {
16661 else
16667 }
16669 /* Like tsubst but deals with expressions and performs semantic
16670 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16672 tree
16674 tree args,
16675 tsubst_flags_t complain,
16676 tree in_decl,
16679 {
16680 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16681 #define RECUR(NODE) \
16682 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16684 integral_constant_expression_p)
16687 location_t loc;
16696 /* N3276 decltype magic only applies to calls at the top level or on the
16697 right side of a comma. */
16702 {
16705 /* Fall through. */
16707 {
16708 tree decl;
16709 cp_id_kind idk;
16714 {
16717 }
16719 /* Look up the name. */
16722 /* By convention, expressions use ERROR_MARK_NODE to indicate
16723 failure, not NULL_TREE. */
16729 integral_constant_expression_p,
16737 input_location);
16741 {
16745 }
16747 }
16750 {
16751 tree object;
16761 {
16766 }
16772 {
16775 }
16776 else
16783 else
16785 }
16788 {
16792 {
16793 /* A type conversion to reference type will be enclosed in
16794 such an indirect ref, but the substitution of the cast
16795 will have also added such an indirect ref. */
16798 }
16799 else
16807 }
16810 {
16814 }
16817 {
16824 flags));
16825 }
16828 {
16832 }
16839 {
16840 tree type;
16846 {
16851 }
16857 {
16875 }
16878 }
16912 else
16914 in_decl);
16949 {
16956 tree r = build_x_binary_op
16958 op0,
16960 ? ERROR_MARK
16962 op1,
16964 ? ERROR_MARK
16972 }
16975 {
16979 }
16992 {
17001 }
17006 /* Fall through */
17009 {
17010 tree r;
17016 {
17017 /* When there are no ARGS, we are trying to evaluate a
17018 non-dependent expression from the parser. Trying to do
17019 the substitutions may not work. */
17022 }
17023 else
17024 {
17029 else
17032 /*integral_constant_expression_p=*/
17036 }
17040 else
17044 {
17046 {
17048 {
17052 }
17053 else
17057 }
17059 }
17061 }
17064 {
17074 }
17090 {
17094 tree r = build_x_modify_expr
17097 /* TREE_NO_WARNING must be set if either the expression was
17098 parenthesized or it uses an operator such as >>= rather
17099 than plain assignment. In the former case, it was already
17100 set and must be copied. In the latter case,
17101 build_x_modify_expr sets it and it must not be reset
17102 here. */
17107 }
17112 /* Remember that there was a reference to this entity. */
17119 {
17124 tree ret;
17128 else
17129 {
17133 }
17135 /* If there was an initializer in the original tree, but it
17136 instantiated to an empty list, then we should pass a
17137 non-NULL empty vector to tell build_new that it was an
17138 empty initializer() rather than no initializer. This can
17139 only happen when the initializer is a pack expansion whose
17140 parameter packs are of length zero. */
17143 else
17144 {
17148 else
17149 {
17152 }
17153 }
17159 complain);
17167 }
17170 {
17176 complain));
17177 }
17180 {
17184 integral_constant_expression_p);
17186 op0,
17189 }
17192 {
17193 tree function;
17198 tree ret;
17201 /* Internal function with no arguments. */
17205 /* When we parsed the expression, we determined whether or
17206 not Koenig lookup should be performed. */
17209 {
17212 }
17214 {
17219 }
17221 {
17222 /* Do nothing; calling tsubst_copy_and_build on an identifier
17223 would incorrectly perform unqualified lookup again.
17225 Note that we can also have an IDENTIFIER_NODE if the earlier
17226 unqualified lookup found a member function; in that case
17227 koenig_p will be false and we do want to do the lookup
17228 again to find the instantiated member function.
17230 FIXME but doing that causes c++/15272, so we need to stop
17231 using IDENTIFIER_NODE in that situation. */
17233 }
17234 else
17235 {
17237 {
17243 }
17244 else
17249 /* Avoid error about taking the address of a constructor. */
17253 in_decl,
17255 integral_constant_expression_p);
17259 }
17264 {
17269 else
17270 {
17271 /* Expand the pack expansion and push each entry onto
17272 CALL_ARGS. */
17275 {
17280 {
17285 }
17286 }
17287 else
17288 {
17289 /* A partial substitution. Add one entry. */
17291 }
17292 }
17293 }
17295 /* We do not perform argument-dependent lookup if normal
17296 lookup finds a non-function, in accordance with the
17297 expected resolution of DR 218. */
17300 /* If lookup found a member function, the Koenig lookup is
17301 not appropriate, even if an unqualified-name was used
17302 to denote the function. */
17305 /* Only do this when substitution turns a dependent call
17306 into a non-dependent call. */
17314 {
17316 {
17317 /* For backwards compatibility and good diagnostics, try
17318 the unqualified lookup again if we aren't in SFINAE
17319 context. */
17320 tree unq = (tsubst_copy_and_build
17322 integral_constant_expression_p));
17324 {
17327 }
17330 {
17331 /* In a lambda fn, we have to be careful to not
17332 introduce new this captures. Legacy code can't
17333 be using lambdas anyway, so it's ok to be
17334 stricter. */
17339 "and no declarations were found by "
17340 "argument-dependent lookup at the point "
17347 else
17351 {
17362 {
17364 input_location);
17366 "declarations in dependent base %qT are "
17372 else
17376 }
17377 else
17379 "%qD declared here, later in the "
17382 {
17385 }
17386 }
17389 }
17390 }
17392 {
17397 }
17398 }
17400 /* Remember that there was a reference to this entity. */
17404 {
17407 }
17409 /* Put back tf_decltype for the actual call. */
17414 {
17418 {
17420 "wrong number of arguments to "
17423 }
17424 else
17426 input_location),
17431 /* Unsupported internal function with arguments. */
17433 }
17436 complain);
17438 {
17453 complain);
17454 else
17455 ret = (build_new_method_call
17460 complain));
17461 }
17462 else
17465 koenig_p,
17466 complain);
17471 {
17477 {
17483 {
17485 /* The thunk location is not interesting. */
17487 }
17488 }
17489 }
17492 }
17495 {
17501 {
17503 {
17508 }
17509 else
17510 {
17515 }
17517 }
17518 else
17519 {
17522 }
17526 }
17529 {
17534 input_location));
17535 }
17538 {
17546 {
17547 /* We have pack expansions, so expand those and
17548 create a new list out of it. */
17551 tree chain;
17554 /* Expand the argument expressions. */
17562 /* Build the rest of the list. */
17567 /* Determine the number of arguments. */
17569 {
17572 }
17575 else
17576 {
17577 /* Since we only performed a partial substitution into
17578 the argument pack, we only RETURN (a single list
17579 node. */
17586 }
17588 /* Convert the argument vectors into a TREE_LIST */
17591 {
17592 /* Grab the Ith values. */
17593 i--;
17596 value
17600 /* Build the list (backwards). */
17602 }
17605 }
17621 }
17624 {
17625 tree object;
17626 tree object_type;
17627 tree member;
17628 tree r;
17632 /* Remember that there was a reference to this entity. */
17643 else
17649 {
17654 }
17658 {
17660 {
17665 {
17668 }
17670 {
17675 }
17676 }
17677 }
17680 {
17681 /* Lookup the template functions now that we know what the
17682 scope is. */
17690 {
17693 args);
17694 member = (adjust_result_of_qualified_name_lookup
17696 object_type));
17697 }
17698 else
17699 {
17701 input_location);
17703 }
17704 }
17708 {
17710 {
17714 else
17717 }
17719 }
17723 complain);
17727 }
17734 {
17742 tree r;
17747 /* digest_init will do the wrong thing if we let it. */
17751 /* We do not want to process the index of aggregate
17752 initializers as they are identifier nodes which will be
17753 looked up by digest_init. */
17759 {
17761 /* An identifier index is looked up in the type
17762 being initialized, not the current scope. */
17767 {
17768 /* Substitute into the pack expansion. */
17770 in_decl);
17774 ;
17776 /* Just move the argument into place. */
17778 else
17779 {
17780 /* Update the length of the final CONSTRUCTOR
17781 arguments vector, and note that we will need to
17782 copy.*/
17785 }
17786 }
17787 else
17789 }
17792 {
17797 {
17799 {
17804 }
17805 else
17807 }
17808 }
17814 {
17819 }
17823 }
17826 {
17829 {
17832 }
17833 else
17834 {
17837 }
17838 }
17844 {
17845 /* We don't build decls for an instantiation of a
17846 variadic capture proxy, we instantiate the elements
17847 when needed. */
17850 }
17851 /* Fall through */
17854 {
17856 /* ??? We're doing a subset of finish_id_expression here. */
17858 && !processing_template_decl
17859 && !cp_unevaluated_operand
17862 {
17864 /* Replace an evaluated use of the thread_local variable with
17865 a call to its wrapper. */
17867 }
17869 {
17873 }
17876 /* If the original type was a reference, we'll be wrapped in
17877 the appropriate INDIRECT_REF. */
17880 }
17883 {
17887 }
17890 {
17891 tree object_ptr
17898 }
17905 {
17916 }
17919 {
17925 integral_constant_expression_p);
17929 /* If the resulting list of expression statement is empty,
17930 fold it further into void_node. */
17935 }
17938 {
17956 /* For a function or variable scope, we want to use tsubst so that we
17957 don't complain about referring to an auto before deduction. */
17960 {
17961 /* Look up the parameter we want directly, as tsubst_copy
17962 doesn't do what we need. */
17968 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17971 }
17973 /* For a field, use tsubst_copy so that we look up the existing field
17974 rather than build a new one. */
17976 else
17983 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17985 /* Now that we know visibility, instantiate the type so we have a
17986 declaration of the op() for later calls to lambda_function. */
17997 }
18000 /* We can get here for a constant initializer of non-dependent type.
18001 FIXME stop folding in cp_parser_initializer_clause. */
18002 {
18004 complain);
18006 }
18010 integral_constant_expression_p));
18016 {
18021 complain));
18022 }
18028 /* Handle Objective-C++ constructs, if appropriate. */
18029 {
18030 tree subst
18035 }
18037 }
18039 #undef RECUR
18040 #undef RETURN
18041 out:
18044 }
18046 /* Verify that the instantiated ARGS are valid. For type arguments,
18047 make sure that the type's linkage is ok. For non-type arguments,
18048 make sure they are constants if they are integral or enumerations.
18049 Emit an error under control of COMPLAIN, and return TRUE on error. */
18051 static bool
18053 {
18057 {
18067 }
18069 {
18070 /* [basic.link]: A name with no linkage (notably, the name
18071 of a class or enumeration declared in a local scope)
18072 shall not be used to declare an entity with linkage.
18073 This implies that names with no linkage cannot be used as
18074 template arguments
18076 DR 757 relaxes this restriction for C++0x. */
18081 {
18082 /* DR 488 makes use of a type with no linkage cause
18083 type deduction to fail. */
18085 {
18088 else
18091 }
18093 }
18094 /* In order to avoid all sorts of complications, we do not
18095 allow variably-modified types as template arguments. */
18097 {
18101 }
18102 }
18103 /* Class template and alias template arguments should be OK. */
18105 ;
18106 /* A non-type argument of integral or enumerated type must be a
18107 constant. */
18112 {
18116 }
18118 }
18120 static bool
18122 {
18127 {
18130 }
18134 }
18136 /* We're out of SFINAE context now, so generate diagnostics for the access
18137 errors we saw earlier when instantiating D from TMPL and ARGS. */
18139 static void
18141 {
18153 }
18155 /* Instantiate the indicated variable, function, or alias template TMPL with
18156 the template arguments in TARG_PTR. */
18158 static tree
18160 {
18162 tree fndecl;
18163 tree gen_tmpl;
18164 tree spec;
18172 /* If this function is a clone, handle it specially. */
18174 {
18175 tree spec;
18176 tree clone;
18178 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18179 DECL_CLONED_FUNCTION. */
18185 /* Look for the clone. */
18189 /* We should always have found the clone by now. */
18192 }
18197 /* Check to see if we already have this specialization. */
18201 /* targ_ptr only has the innermost template args, so add the outer ones
18202 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18203 the case of a non-dependent call within a template definition). */
18204 targ_ptr = (add_outermost_template_args
18206 targ_ptr));
18208 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18209 but it doesn't seem to be on the hot path. */
18218 {
18220 {
18224 }
18226 }
18229 complain))
18232 /* We are building a FUNCTION_DECL, during which the access of its
18233 parameters and return types have to be checked. However this
18234 FUNCTION_DECL which is the desired context for access checking
18235 is not built yet. We solve this chicken-and-egg problem by
18236 deferring all checks until we have the FUNCTION_DECL. */
18239 /* Instantiation of the function happens in the context of the function
18240 template, not the context of the overload resolution we're doing. */
18242 /* If there are dependent arguments, e.g. because we're doing partial
18243 ordering, make sure processing_template_decl stays set. */
18247 {
18251 }
18257 {
18258 /* We need to determine if we're using a partial or explicit
18259 specialization now, because the type of the variable could be
18260 different. */
18266 {
18271 }
18272 }
18274 /* Substitute template parameters to obtain the specialization. */
18282 {
18285 }
18287 /* The DECL_TI_TEMPLATE should always be the immediate parent
18288 template, not the most general template. */
18292 /* Now we know the specialization, compute access previously
18293 deferred. Do no access control for inheriting constructors,
18294 as we already checked access for the inherited constructor. */
18297 {
18302 }
18305 /* If we've just instantiated the main entry point for a function,
18306 instantiate all the alternate entry points as well. We do this
18307 by cloning the instantiation of the main entry point, not by
18308 instantiating the template clones. */
18313 {
18315 {
18316 /* Remember to reinstantiate when we're out of SFINAE so the user
18317 can see the errors. */
18319 }
18321 }
18323 }
18325 /* Wrapper for instantiate_template_1. */
18327 tree
18329 {
18330 tree ret;
18335 }
18337 /* Instantiate the alias template TMPL with ARGS. Also push a template
18338 instantiation level, which instantiate_template doesn't do because
18339 functions and variables have sufficient context established by the
18340 callers. */
18342 static tree
18344 {
18351 {
18354 }
18356 args =
18364 /* We can't free this if a pending_template entry or last_error_tinst_level
18365 is pointing at it. */
18371 }
18373 /* PARM is a template parameter pack for FN. Returns true iff
18374 PARM is used in a deducible way in the argument list of FN. */
18376 static bool
18378 {
18381 {
18383 tree packs;
18389 {
18390 /* The template parameter pack is used in a function parameter
18391 pack. If this is the end of the parameter list, the
18392 template parameter pack is deducible. */
18395 else
18396 /* Otherwise, not. Well, it could be deduced from
18397 a non-pack parameter, but doing so would end up with
18398 a deduction mismatch, so don't bother. */
18400 }
18401 }
18402 /* The template parameter pack isn't used in any function parameter
18403 packs, but it might be used deeper, e.g. tuple<Args...>. */
18405 }
18407 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18408 NARGS elements of the arguments that are being used when calling
18409 it. TARGS is a vector into which the deduced template arguments
18410 are placed.
18412 Returns either a FUNCTION_DECL for the matching specialization of FN or
18413 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18414 true, diagnostics will be printed to explain why it failed.
18416 If FN is a conversion operator, or we are trying to produce a specific
18417 specialization, RETURN_TYPE is the return type desired.
18419 The EXPLICIT_TARGS are explicit template arguments provided via a
18420 template-id.
18422 The parameter STRICT is one of:
18424 DEDUCE_CALL:
18425 We are deducing arguments for a function call, as in
18426 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18427 deducing arguments for a call to the result of a conversion
18428 function template, as in [over.call.object].
18430 DEDUCE_CONV:
18431 We are deducing arguments for a conversion function, as in
18432 [temp.deduct.conv].
18434 DEDUCE_EXACT:
18435 We are deducing arguments when doing an explicit instantiation
18436 as in [temp.explicit], when determining an explicit specialization
18437 as in [temp.expl.spec], or when taking the address of a function
18438 template, as in [temp.deduct.funcaddr]. */
18440 tree
18442 tree explicit_targs,
18443 tree targs,
18446 tree return_type,
18447 unification_kind_t strict,
18451 {
18452 tree parms;
18453 tree fntype;
18466 tree tinst;
18472 full_targs = (add_outermost_template_args
18474 targs));
18479 /* In C++0x, it's possible to have a function template whose type depends
18480 on itself recursively. This is most obvious with decltype, but can also
18481 occur with enumeration scope (c++/48969). So we need to catch infinite
18482 recursion and reject the substitution at deduction time; this function
18483 will return error_mark_node for any repeated substitution.
18485 This also catches excessive recursion such as when f<N> depends on
18486 f<N-1> across all integers, and returns error_mark_node for all the
18487 substitutions back up to the initial one.
18489 This is, of course, not reentrant. */
18499 {
18500 /* [temp.deduct]
18502 The specified template arguments must match the template
18503 parameters in kind (i.e., type, nontype, template), and there
18504 must not be more arguments than there are parameters;
18505 otherwise type deduction fails.
18507 Nontype arguments must match the types of the corresponding
18508 nontype template parameters, or must be convertible to the
18509 types of the corresponding nontype parameters as specified in
18510 _temp.arg.nontype_, otherwise type deduction fails.
18512 All references in the function type of the function template
18513 to the corresponding template parameters are replaced by the
18514 specified template argument values. If a substitution in a
18515 template parameter or in the function type of the function
18516 template results in an invalid type, type deduction fails. */
18527 explicit_targs);
18529 /* Adjust any explicit template arguments before entering the
18530 substitution context. */
18531 explicit_targs
18533 complain,
18539 /* Substitute the explicit args into the function type. This is
18540 necessary so that, for instance, explicitly declared function
18541 arguments can match null pointed constants. If we were given
18542 an incomplete set of explicit args, we must not do semantic
18543 processing during substitution as we could create partial
18544 instantiations. */
18546 {
18551 /* Dig out the actual parm. */
18554 {
18557 }
18559 {
18562 }
18565 /* No explicit argument for this template parameter. */
18569 {
18570 /* Mark the argument pack as "incomplete". We could
18571 still deduce more arguments during unification.
18572 We remove this mark in type_unification_real. */
18574 {
18578 }
18580 /* We have some incomplete argument packs. */
18582 }
18583 }
18587 {
18590 }
18593 /* Ignore any access checks; we'll see them again in
18594 instantiate_template and they might have the wrong
18595 access path at this point. */
18607 /* Place the explicitly specified arguments in TARGS. */
18611 }
18613 /* Never do unification on the 'this' parameter. */
18617 {
18618 /* We're deducing for a call to the result of a template conversion
18619 function. The parms we really want are in return_type. */
18623 }
18625 {
18634 }
18636 /* We allow incomplete unification without an error message here
18637 because the standard doesn't seem to explicitly prohibit it. Our
18638 callers must be ready to deal with unification failures in any
18639 event. */
18642 /* If we aren't explaining yet, push tinst context so we can see where
18643 any errors (e.g. from class instantiations triggered by instantiation
18644 of default template arguments) come from. If we are explaining, this
18645 context is redundant. */
18647 {
18650 }
18652 /* type_unification_real will pass back any access checks from default
18653 template argument substitution. */
18665 /* Now that we have bindings for all of the template arguments,
18666 ensure that the arguments deduced for the template template
18667 parameters have compatible template parameter lists. We cannot
18668 check this property before we have deduced all template
18669 arguments, because the template parameter types of a template
18670 template parameter might depend on prior template parameters
18671 deduced after the template template parameter. The following
18672 ill-formed example illustrates this issue:
18674 template<typename T, template<T> class C> void f(C<5>, T);
18676 template<int N> struct X {};
18678 void g() {
18679 f(X<5>(), 5l); // error: template argument deduction fails
18680 }
18682 The template parameter list of 'C' depends on the template type
18683 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18684 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18685 time that we deduce 'C'. */
18688 {
18691 }
18693 /* All is well so far. Now, check:
18695 [temp.deduct]
18697 When all template arguments have been deduced, all uses of
18698 template parameters in nondeduced contexts are replaced with
18699 the corresponding deduced argument values. If the
18700 substitution results in an invalid type, as described above,
18701 type deduction fails. */
18704 {
18707 }
18709 /* Also collect access checks from the instantiation. */
18722 /* Now perform any access checks encountered during substitution. */
18729 /* If we're looking for an exact match, check that what we got
18730 is indeed an exact match. It might not be if some template
18731 parameters are used in non-deduced contexts. But don't check
18732 for an exact match if we have dependent template arguments;
18733 in that case we're doing partial ordering, and we already know
18734 that we have two candidates that will provide the actual type. */
18736 {
18740 tree sarg
18746 {
18750 }
18751 }
18753 /* After doing deduction with the inherited constructor, actually return an
18754 instantiation of the inheriting constructor. */
18760 fail:
18763 {
18765 /* Reset once we're all the way out. */
18767 }
18769 /* We can't free this if a pending_template entry or last_error_tinst_level
18770 is pointing at it. */
18776 }
18778 /* Adjust types before performing type deduction, as described in
18779 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18780 sections are symmetric. PARM is the type of a function parameter
18781 or the return type of the conversion function. ARG is the type of
18782 the argument passed to the call, or the type of the value
18783 initialized with the result of the conversion function.
18784 ARG_EXPR is the original argument expression, which may be null. */
18786 static int
18790 tree arg_expr)
18791 {
18795 {
18800 /* Swap PARM and ARG throughout the remainder of this
18801 function; the handling is precisely symmetric since PARM
18802 will initialize ARG rather than vice versa. */
18807 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18808 too, but here handle it by stripping the reference from PARM
18809 rather than by adding it to ARG. */
18817 /* Nothing else to do in this case. */
18822 }
18825 {
18826 /* [temp.deduct.call]
18828 If P is not a reference type:
18830 --If A is an array type, the pointer type produced by the
18831 array-to-pointer standard conversion (_conv.array_) is
18832 used in place of A for type deduction; otherwise,
18834 --If A is a function type, the pointer type produced by
18835 the function-to-pointer standard conversion
18836 (_conv.func_) is used in place of A for type deduction;
18837 otherwise,
18839 --If A is a cv-qualified type, the top level
18840 cv-qualifiers of A's type are ignored for type
18841 deduction. */
18846 else
18848 }
18850 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18851 reference to a cv-unqualified template parameter that does not represent a
18852 template parameter of a class template (during class template argument
18853 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18854 an lvalue, the type "lvalue reference to A" is used in place of A for type
18855 deduction. */
18862 /* try_one_overload doesn't provide an arg_expr, but
18863 functions are always lvalues. */
18867 /* [temp.deduct.call]
18869 If P is a cv-qualified type, the top level cv-qualifiers
18870 of P's type are ignored for type deduction. If P is a
18871 reference type, the type referred to by P is used for
18872 type deduction. */
18875 {
18878 }
18880 /* DR 322. For conversion deduction, remove a reference type on parm
18881 too (which has been swapped into ARG). */
18886 }
18888 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18889 template which does contain any deducible template parameters; check if
18890 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18891 unify_one_argument. */
18893 static int
18896 {
18897 tree type;
18901 else
18908 {
18912 }
18914 {
18919 }
18923 else
18925 }
18929 /* Returns true iff the expression EXPR is one from which a template
18930 argument can be deduced. In other words, if it's an undecorated
18931 use of a template non-type parameter. */
18933 static bool
18935 {
18936 /* Strip implicit conversions. */
18940 }
18942 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18943 deducible way; that is, if it has a max value of <PARM> - 1. */
18945 static bool
18947 {
18956 }
18958 /* Returns true iff the template arguments ARGS use a template parameter
18959 in a deducible way. */
18961 static bool
18963 {
18965 {
18970 else
18971 {
18978 else
18980 }
18983 }
18985 }
18987 /* Returns true iff TYPE contains any deducible references to template
18988 parameters, as per 14.8.2.5. */
18990 static bool
18992 {
18996 /* T
18997 cv-list T
18998 TT<T>
18999 TT<i>
19000 TT<> */
19005 /* T*
19006 T&
19007 T&& */
19011 /* T[integer-constant ]
19012 type [i] */
19017 /* T type ::*
19018 type T::*
19019 T T::*
19020 T (type ::*)()
19021 type (T::*)()
19022 type (type ::*)(T)
19023 type (T::*)(T)
19024 T (type ::*)(T)
19025 T (T::*)()
19026 T (T::*)(T) */
19029 || (uses_deducible_template_parms
19032 /* template-name <T> (where template-name refers to a class template)
19033 template-name <i> (where template-name refers to a class template) */
19040 /* type (T)
19041 T()
19042 T(T) */
19045 {
19054 }
19057 }
19059 /* Subroutine of type_unification_real and unify_pack_expansion to
19060 handle unification of a single P/A pair. Parameters are as
19061 for those functions. */
19063 static int
19067 {
19074 /* We can't deduce anything from this, but we might get all the
19075 template args from other function args. */
19078 /* Implicit conversions (Clause 4) will be performed on a function
19079 argument to convert it to the type of the corresponding function
19080 parameter if the parameter type contains no template-parameters that
19081 participate in template argument deduction. */
19084 /* For function parameters with no deducible template parameters,
19085 just return. We'll check non-dependent conversions later. */
19089 {
19091 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19092 | UNIFY_ALLOW_MORE_CV_QUAL
19106 }
19108 /* We only do these transformations if this is the top-level
19109 parameter_type_list in a call or declaration matching; in other
19110 situations (nested function declarators, template argument lists) we
19111 won't be comparing a type to an expression, and we don't do any type
19112 adjustments. */
19114 {
19116 {
19119 {
19120 /* [temp.deduct.type] A template-argument can be
19121 deduced from a pointer to function or pointer
19122 to member function argument if the set of
19123 overloaded functions does not contain function
19124 templates and at most one of a set of
19125 overloaded functions provides a unique
19126 match. */
19133 }
19139 }
19141 arg_strict |=
19143 }
19144 else
19149 /* For deduction from an init-list we need the actual list. */
19153 }
19155 /* for_each_template_parm callback that always returns 0. */
19157 static int
19159 {
19161 }
19163 /* for_each_template_parm any_fn callback to handle deduction of a template
19164 type argument from the type of an array bound. */
19166 static int
19168 {
19176 {
19182 }
19184 /* Keep walking. */
19186 }
19188 /* Try to deduce any not-yet-deduced template type arguments from the type of
19189 an array bound. This is handled separately from unify because 14.8.2.5 says
19190 "The type of a type parameter is only deduced from an array bound if it is
19191 not otherwise deduced." */
19193 static void
19195 {
19200 }
19202 /* Most parms like fn_type_unification.
19204 If SUBR is 1, we're being called recursively (to unify the
19205 arguments of a function or method parameter of a function
19206 template).
19208 CHECKS is a pointer to a vector of access checks encountered while
19209 substituting default template arguments. */
19211 static int
19213 tree full_targs,
19214 tree xparms,
19218 unification_kind_t strict,
19222 {
19227 tree parms;
19238 /* Reset the number of non-defaulted template arguments contained
19239 in TARGS. */
19242 again:
19250 {
19255 /* For a function parameter pack that occurs at the end of the
19256 parameter-declaration-list, the type A of each remaining
19257 argument of the call is compared with the type P of the
19258 declarator-id of the function parameter pack. */
19264 /* For a function parameter pack that does not occur at the
19265 end of the parameter-declaration-list, the type of the
19266 parameter pack is a non-deduced context. */
19273 explain_p))
19275 }
19280 {
19281 /* Unify the remaining arguments with the pack expansion type. */
19282 tree argvec;
19285 /* Allocate a TREE_VEC and copy in all of the arguments */
19290 /* Copy the parameter into parmvec. */
19296 /* Advance to the end of the list of parameters. */
19298 }
19300 /* Fail if we've reached the end of the parm list, and more args
19301 are present, and the parm list isn't variadic. */
19304 /* Fail if parms are left and they don't have default values and
19305 they aren't all deduced as empty packs (c++/57397). This is
19306 consistent with sufficient_parms_p. */
19309 {
19313 do
19314 {
19317 count++;
19319 }
19323 type_pack_p);
19324 }
19327 {
19328 tsubst_flags_t complain = (explain_p
19329 ? tf_warning_or_error
19334 {
19338 /* Clear the "incomplete" flags on all argument packs now so that
19339 substituting them into later default arguments works. */
19341 {
19344 }
19352 {
19357 }
19359 /* If this is an undeduced nontype parameter that depends on
19360 a type parameter, try another pass; its type may have been
19361 deduced from a later argument than the one from which
19362 this parameter can be deduced. */
19366 {
19369 }
19371 /* Core issue #226 (C++0x) [temp.deduct]:
19373 If a template argument has not been deduced, its
19374 default template argument, if any, is used.
19376 When we are in C++98 mode, TREE_PURPOSE will either
19377 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19378 to explicitly check cxx_dialect here. */
19380 /* OK, there is a default argument. Wait until after the
19381 conversion check to do substitution. */
19384 /* If the type parameter is a parameter pack, then it will
19385 be deduced to an empty parameter pack. */
19387 {
19388 tree arg;
19391 {
19394 }
19395 else
19402 }
19405 }
19407 /* DR 1391: All parameters have args, now check non-dependent parms for
19408 convertibility. */
19412 {
19418 /* For a function parameter pack that occurs at the end of the
19419 parameter-declaration-list, the type A of each remaining
19420 argument of the call is compared with the type P of the
19421 declarator-id of the function parameter pack. */
19427 /* For a function parameter pack that does not occur at the
19428 end of the parameter-declaration-list, the type of the
19429 parameter pack is a non-deduced context. */
19438 explain_p))
19440 }
19442 /* Now substitute into the default template arguments. */
19444 {
19468 else
19476 {
19478 /* The position of the first default template argument,
19479 is also the number of non-defaulted arguments in TARGS.
19480 Record that. */
19483 }
19484 }
19488 }
19494 }
19496 /* Subroutine of type_unification_real. Args are like the variables
19497 at the call site. ARG is an overloaded function (or template-id);
19498 we try deducing template args from each of the overloads, and if
19499 only one succeeds, we go with that. Modifies TARGS and returns
19500 true on success. */
19502 static bool
19504 tree targs,
19505 tree parm,
19506 tree arg,
19507 unification_kind_t strict,
19510 {
19517 {
19520 }
19521 else
19525 /* Handle `&x' where `x' is some static or non-static member
19526 function name. */
19532 /* Strip baselink information. */
19537 {
19538 /* If we got some explicit template args, we need to plug them into
19539 the affected templates before we try to unify, in case the
19540 explicit args will completely resolve the templates in question. */
19547 {
19560 {
19565 {
19568 }
19569 }
19572 }
19573 /* If no templates (or more than one) are fully resolved by the
19574 explicit arguments, this template-id is a non-deduced context; it
19575 could still be OK if we deduce all template arguments for the
19576 enclosing call through other arguments. */
19579 }
19582 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19583 -- but the deduction does not succeed because the expression is
19584 not just the function on its own. */
19586 else
19588 {
19593 {
19596 }
19597 }
19599 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19600 to function or pointer to member function argument if the set of
19601 overloaded functions does not contain function templates and at most
19602 one of a set of overloaded functions provides a unique match.
19604 So if we found multiple possibilities, we return success but don't
19605 deduce anything. */
19608 {
19612 {
19617 /* Don't forget explicit template arguments in a pack. */
19621 }
19622 }
19627 }
19629 /* Core DR 115: In contexts where deduction is done and fails, or in
19630 contexts where deduction is not done, if a template argument list is
19631 specified and it, along with any default template arguments, identifies
19632 a single function template specialization, then the template-id is an
19633 lvalue for the function template specialization. */
19635 tree
19637 {
19650 {
19653 }
19655 {
19658 }
19660 {
19663 }
19666 {
19670 /* If we got some explicit template args, we need to plug them into
19671 the affected templates before we try to unify, in case the
19672 explicit args will completely resolve the templates in question. */
19680 {
19693 {
19696 {
19699 }
19701 {
19704 }
19705 }
19706 }
19708 {
19716 {
19717 tree base
19720 }
19724 }
19726 /* There were no good options and at least one bad one, so let the
19727 user know what the problem is. */
19729 }
19731 }
19733 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19734 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19735 different overloads deduce different arguments for a given parm.
19736 ADDR_P is true if the expression for which deduction is being
19737 performed was of the form "& fn" rather than simply "fn".
19739 Returns 1 on success. */
19741 static int
19743 tree orig_targs,
19744 tree targs,
19745 tree parm,
19746 tree arg,
19747 unification_kind_t strict,
19751 {
19753 tree tempargs;
19759 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19760 to function or pointer to member function argument if the set of
19761 overloaded functions does not contain function templates and at most
19762 one of a set of overloaded functions provides a unique match.
19764 So if this is a template, just return success. */
19776 /* We don't copy orig_targs for this because if we have already deduced
19777 some template args from previous args, unify would complain when we
19778 try to deduce a template parameter for the same argument, even though
19779 there isn't really a conflict. */
19786 /* First make sure we didn't deduce anything that conflicts with
19787 explicitly specified args. */
19789 {
19796 /* Since we're unifying against ourselves, we will fill in
19797 template args used in the function parm list with our own
19798 template parms. Discard them. */
19801 {
19802 /* Check that the argument at each index of the deduced argument pack
19803 is equivalent to the corresponding explicitly specified argument.
19804 We may have deduced more arguments than were explicitly specified,
19805 and that's OK. */
19807 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19808 that's wrong if we deduce the same argument pack from multiple
19809 function arguments: it's only incomplete the first time. */
19822 }
19825 }
19828 {
19833 }
19836 }
19838 /* PARM is a template class (perhaps with unbound template
19839 parameters). ARG is a fully instantiated type. If ARG can be
19840 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19841 TARGS are as for unify. */
19843 static tree
19846 {
19847 tree copy_of_targs;
19857 /* We need to make a new template argument vector for the call to
19858 unify. If we used TARGS, we'd clutter it up with the result of
19859 the attempted unification, even if this class didn't work out.
19860 We also don't want to commit ourselves to all the unifications
19861 we've already done, since unification is supposed to be done on
19862 an argument-by-argument basis. In other words, consider the
19863 following pathological case:
19865 template <int I, int J, int K>
19866 struct S {};
19868 template <int I, int J>
19869 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19871 template <int I, int J, int K>
19872 void f(S<I, J, K>, S<I, I, I>);
19874 void g() {
19875 S<0, 0, 0> s0;
19876 S<0, 1, 2> s2;
19878 f(s0, s2);
19879 }
19881 Now, by the time we consider the unification involving `s2', we
19882 already know that we must have `f<0, 0, 0>'. But, even though
19883 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19884 because there are two ways to unify base classes of S<0, 1, 2>
19885 with S<I, I, I>. If we kept the already deduced knowledge, we
19886 would reject the possibility I=1. */
19890 {
19894 }
19896 /* If unification failed, we're done. */
19902 }
19904 /* Given a template type PARM and a class type ARG, find the unique
19905 base type in ARG that is an instance of PARM. We do not examine
19906 ARG itself; only its base-classes. If there is not exactly one
19907 appropriate base class, return NULL_TREE. PARM may be the type of
19908 a partial specialization, as well as a plain template type. Used
19909 by unify. */
19911 static enum template_base_result
19914 {
19916 tree binfo;
19922 {
19923 /* The type could not be completed. */
19926 }
19928 /* Walk in inheritance graph order. The search order is not
19929 important, and this avoids multiple walks of virtual bases. */
19931 {
19936 {
19937 /* If there is more than one satisfactory baseclass, then:
19939 [temp.deduct.call]
19941 If they yield more than one possible deduced A, the type
19942 deduction fails.
19944 applies. */
19946 {
19949 }
19952 }
19953 }
19957 }
19959 /* Returns the level of DECL, which declares a template parameter. */
19961 static int
19963 {
19965 {
19975 }
19977 }
19979 /* Decide whether ARG can be unified with PARM, considering only the
19980 cv-qualifiers of each type, given STRICT as documented for unify.
19981 Returns nonzero iff the unification is OK on that basis. */
19983 static int
19985 {
19991 {
19992 /* Although a CVR qualifier is ignored when being applied to a
19993 substituted template parameter ([8.3.2]/1 for example), that
19994 does not allow us to unify "const T" with "int&" because both
19995 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19996 It is ok when we're allowing additional CV qualifiers
19997 at the outer level [14.8.2.1]/3,1st bullet. */
20007 }
20018 }
20020 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20021 void
20023 {
20027 {
20030 }
20031 else
20032 {
20035 }
20036 }
20038 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20039 do { \
20040 if (unify (TP, TA, P, A, S, EP)) \
20041 return 1; \
20042 } while (0)
20044 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20045 expansion at the end of PACKED_PARMS. Returns 0 if the type
20046 deduction succeeds, 1 otherwise. STRICT is the same as in
20047 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20048 function call argument list. We'll need to adjust the arguments to make them
20049 types. SUBR tells us if this is from a recursive call to
20050 type_unification_real, or for comparing two template argument
20051 lists. */
20053 static int
20057 {
20058 tree parm
20068 /* Determine the parameter packs we will be deducing from the
20069 pattern, and record their current deductions. */
20072 {
20076 /* Determine the index and level of this parameter pack. */
20079 /* Keep track of the parameter packs and their corresponding
20080 argument packs. */
20083 }
20085 /* Loop through all of the arguments that have not yet been
20086 unified and unify each with the pattern. */
20088 {
20089 tree parm;
20093 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20094 or the element of its argument pack at the current index if
20095 this argument was explicitly specified. */
20097 {
20106 {
20109 }
20111 }
20113 /* If we had explicit template arguments, substitute them into the
20114 pattern before deduction. */
20116 {
20117 /* Some arguments might still be unspecified or dependent. */
20125 NULL_TREE);
20130 }
20131 else
20134 /* Unify the pattern with the current argument. */
20136 explain_p))
20139 /* For each parameter pack, collect the deduced value. */
20141 {
20147 }
20148 }
20150 /* Verify that the results of unification with the parameter packs
20151 produce results consistent with what we've seen before, and make
20152 the deduced argument packs available. */
20154 {
20161 /* By default keep the original deduced argument pack.
20162 If necessary, more specific code is going to update the
20163 resulting deduced argument later down in this function. */
20167 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20168 actually deduce anything. */
20176 {
20177 /* If we had fewer function args than explicit template args,
20178 just use the explicits. */
20183 }
20186 {
20187 tree result;
20188 /* Build the deduced *_ARGUMENT_PACK. */
20190 {
20193 }
20194 else
20199 /* Note the deduced argument packs for this parameter
20200 pack. */
20202 }
20206 {
20207 /* We only had the explicitly-provided arguments before, but
20208 now we have a complete set of arguments. */
20214 }
20215 else
20216 {
20222 /* Inconsistent unification of this parameter pack. */
20224 bad_old_arg,
20225 bad_new_arg);
20226 }
20227 }
20230 }
20232 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20233 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20234 parameters and return value are as for unify. */
20236 static int
20240 {
20241 tree parm_max;
20242 tree arg_max;
20246 /* Our representation of array types uses "N - 1" as the
20247 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20248 not an integer constant. We cannot unify arbitrarily
20249 complex expressions, so we eliminate the MINUS_EXPRs
20250 here. */
20254 {
20257 }
20261 {
20262 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20263 trying to unify the type of a variable with the type
20264 of a template parameter. For example:
20266 template <unsigned int N>
20267 void f (char (&) [N]);
20268 int g();
20269 void h(int i) {
20270 char a[g(i)];
20271 f(a);
20272 }
20274 Here, the type of the ARG will be "int [g(i)]", and
20275 may be a SAVE_EXPR, etc. */
20279 }
20281 /* If only one of the bounds used a MINUS_EXPR, compensate
20282 by adding one to the other bound. */
20285 integer_type_node,
20286 parm_max,
20287 integer_one_node);
20290 integer_type_node,
20291 arg_max,
20292 integer_one_node);
20296 }
20298 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20302 static pa_kind_t
20304 {
20313 else
20315 }
20317 /* Deduce the value of template parameters. TPARMS is the (innermost)
20318 set of template parameters to a template. TARGS is the bindings
20319 for those template parameters, as determined thus far; TARGS may
20320 include template arguments for outer levels of template parameters
20321 as well. PARM is a parameter to a template function, or a
20322 subcomponent of that parameter; ARG is the corresponding argument.
20323 This function attempts to match PARM with ARG in a manner
20324 consistent with the existing assignments in TARGS. If more values
20325 are deduced, then TARGS is updated.
20327 Returns 0 if the type deduction succeeds, 1 otherwise. The
20328 parameter STRICT is a bitwise or of the following flags:
20330 UNIFY_ALLOW_NONE:
20331 Require an exact match between PARM and ARG.
20332 UNIFY_ALLOW_MORE_CV_QUAL:
20333 Allow the deduced ARG to be more cv-qualified (by qualification
20334 conversion) than ARG.
20335 UNIFY_ALLOW_LESS_CV_QUAL:
20336 Allow the deduced ARG to be less cv-qualified than ARG.
20337 UNIFY_ALLOW_DERIVED:
20338 Allow the deduced ARG to be a template base class of ARG,
20339 or a pointer to a template base class of the type pointed to by
20340 ARG.
20341 UNIFY_ALLOW_INTEGER:
20342 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20343 case for more information.
20344 UNIFY_ALLOW_OUTER_LEVEL:
20345 This is the outermost level of a deduction. Used to determine validity
20346 of qualification conversions. A valid qualification conversion must
20347 have const qualified pointers leading up to the inner type which
20348 requires additional CV quals, except at the outer level, where const
20349 is not required [conv.qual]. It would be normal to set this flag in
20350 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20351 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20352 This is the outermost level of a deduction, and PARM can be more CV
20353 qualified at this point.
20354 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20355 This is the outermost level of a deduction, and PARM can be less CV
20356 qualified at this point. */
20358 static int
20361 {
20363 tree targ;
20364 tree tparm;
20366 tsubst_flags_t complain = (explain_p
20367 ? tf_warning_or_error
20370 /* I don't think this will do the right thing with respect to types.
20371 But the only case I've seen it in so far has been array bounds, where
20372 signedness is the only information lost, and I think that will be
20373 okay. */
20381 /* We can't deduce anything from this, but we might get all the
20382 template args from other function args. */
20388 /* If PARM uses template parameters, then we can't bail out here,
20389 even if ARG == PARM, since we won't record unifications for the
20390 template parameters. We might need them if we're trying to
20391 figure out which of two things is more specialized. */
20395 /* Handle init lists early, so the rest of the function can assume
20396 we're dealing with a type. */
20398 {
20403 /* Replace T with std::initializer_list<T> for deduction. */
20410 /* We can only deduce from an initializer list argument if the
20411 parameter is std::initializer_list or an array; otherwise this
20412 is a non-deduced context. */
20417 else
20418 {
20420 /* Deduction is defined in terms of a single type, so just punt
20421 on the (bizarre) std::initializer_list<T...>. */
20424 }
20427 {
20434 {
20438 /* It should only be possible to get here for a call. */
20440 elt_strict |= maybe_adjust_types_for_deduction
20443 }
20446 explain_p);
20447 }
20451 {
20452 /* Also deduce from the length of the initializer list. */
20459 }
20461 /* If the std::initializer_list<T> deduction worked, replace the
20462 deduced A with std::initializer_list<A>. */
20464 {
20469 }
20471 }
20473 /* If parm and arg aren't the same kind of thing (template, type, or
20474 expression), fail early. */
20478 /* Immediately reject some pairs that won't unify because of
20479 cv-qualification mismatches. */
20482 /* It is the elements of the array which hold the cv quals of an array
20483 type, and the elements might be template type parms. We'll check
20484 when we recurse. */
20486 /* We check the cv-qualifiers when unifying with template type
20487 parameters below. We want to allow ARG `const T' to unify with
20488 PARM `T' for example, when computing which of two templates
20489 is more specialized, for example. */
20503 {
20507 /* In a type which contains a nested-name-specifier, template
20508 argument values cannot be deduced for template parameters used
20509 within the nested-name-specifier. */
20521 /* The PARM is not one we're trying to unify. Just check
20522 to see if it matches ARG. */
20523 {
20528 else
20530 }
20537 /* Check for mixed types and values. */
20545 {
20548 {
20549 /* First try to match ARG directly. */
20551 explain_p);
20553 {
20554 /* Otherwise, look for a suitable base of ARG, as below. */
20561 }
20562 }
20563 /* ARG must be constructed from a template class or a template
20564 template parameter. */
20569 /* Deduce arguments T, i from TT<T> or TT<i>. */
20575 /* Fall through to deduce template name. */
20576 }
20580 {
20581 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20583 /* Simple cases: Value already set, does match or doesn't. */
20588 }
20589 else
20590 {
20591 /* If PARM is `const T' and ARG is only `int', we don't have
20592 a match unless we are allowing additional qualification.
20593 If ARG is `const int' and PARM is just `T' that's OK;
20594 that binds `const int' to `T'. */
20599 /* Consider the case where ARG is `const volatile int' and
20600 PARM is `const T'. Then, T should be `volatile int'. */
20601 arg = cp_build_qualified_type_real
20606 /* Simple cases: Value already set, does match or doesn't. */
20612 /* Make sure that ARG is not a variable-sized array. (Note
20613 that were talking about variable-sized arrays (like
20614 `int[n]'), rather than arrays of unknown size (like
20615 `int[]').) We'll get very confused by such a type since
20616 the bound of the array is not constant, and therefore
20617 not mangleable. Besides, such types are not allowed in
20618 ISO C++, so we can do as we please here. We do allow
20619 them for 'auto' deduction, since that isn't ABI-exposed. */
20623 /* Strip typedefs as in convert_template_argument. */
20625 }
20627 /* If ARG is a parameter pack or an expansion, we cannot unify
20628 against it unless PARM is also a parameter pack. */
20633 /* If the argument deduction results is a METHOD_TYPE,
20634 then there is a problem.
20635 METHOD_TYPE doesn't map to any real C++ type the result of
20636 the deduction can not be of that type. */
20650 {
20651 /* The PARM is not one we're trying to unify. Just check
20652 to see if it matches ARG. */
20658 }
20664 {
20669 }
20671 /* [temp.deduct.type] If, in the declaration of a function template
20672 with a non-type template-parameter, the non-type
20673 template-parameter is used in an expression in the function
20674 parameter-list and, if the corresponding template-argument is
20675 deduced, the template-argument type shall match the type of the
20676 template-parameter exactly, except that a template-argument
20677 deduced from an array bound may be of any integral type.
20678 The non-type parameter might use already deduced type parameters. */
20681 {
20685 }
20688 /* Template-parameter dependent expression. Just accept it for now.
20689 It will later be processed in convert_template_argument. */
20690 ;
20696 /* Convert the ARG to the type of PARM; the deduced non-type
20697 template argument must exactly match the types of the
20698 corresponding parameter. */
20701 {
20702 /* We haven't deduced the type of this parameter yet. */
20704 /* We deduce from array bounds in try_array_deduction. */
20706 {
20707 /* Deduce it from the non-type argument. */
20712 }
20713 else
20714 /* Try again later. */
20716 }
20717 else
20720 /* If ARG is a parameter pack or an expansion, we cannot unify
20721 against it unless PARM is also a parameter pack. */
20726 {
20729 }
20734 {
20735 /* A pointer-to-member constant can be unified only with
20736 another constant. */
20740 /* Just unify the class member. It would be useless (and possibly
20741 wrong, depending on the strict flags) to unify also
20742 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20743 arg refer to the same variable, even if through different
20744 classes. For instance:
20746 struct A { int x; };
20747 struct B : A { };
20749 Unification of &A::x and &B::x must succeed. */
20752 }
20755 {
20759 /* [temp.deduct.call]
20761 A can be another pointer or pointer to member type that can
20762 be converted to the deduced A via a qualification
20763 conversion (_conv.qual_).
20765 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20766 This will allow for additional cv-qualification of the
20767 pointed-to types if appropriate. */
20770 /* The derived-to-base conversion only persists through one
20771 level of pointers. */
20776 }
20808 /* We have already checked cv-qualification at the top of the
20809 function. */
20813 /* As far as unification is concerned, this wins. Later checks
20814 will invalidate it if necessary. */
20817 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20818 /* Type INTEGER_CST can come from ordinary constant template args. */
20830 {
20840 /* Check for pack expansions in the parameters. */
20842 {
20844 {
20846 /* We can unify against something with a trailing
20847 parameter pack. */
20849 else
20850 /* [temp.deduct.type]/9: If the template argument list of
20851 P contains a pack expansion that is not the last
20852 template argument, the entire template argument list
20853 is a non-deduced context. */
20855 }
20856 }
20858 /* If we don't have enough arguments to satisfy the parameters
20859 (not counting the pack expression at the end), or we have
20860 too many arguments for a parameter list that doesn't end in
20861 a pack expression, we can't unify. */
20867 /* Unify all of the parameters that precede the (optional)
20868 pack expression. */
20870 {
20875 }
20878 DEDUCE_EXACT,
20881 }
20889 {
20897 }
20902 {
20906 {
20907 /* First, we try to unify the PARM and ARG directly. */
20912 {
20913 /* Fallback to the special case allowed in
20914 [temp.deduct.call]:
20916 If P is a class, and P has the form
20917 template-id, then A can be a derived class of
20918 the deduced A. Likewise, if P is a pointer to
20919 a class of the form template-id, A can be a
20920 pointer to a derived class pointed to by the
20921 deduced A. */
20927 {
20928 /* Don't give the derived diagnostic if we're
20929 already dealing with the same template. */
20930 bool same_template
20936 }
20937 }
20938 }
20942 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20943 Then, we should unify `int' and `U'. */
20945 else
20946 /* There's no chance of unification succeeding. */
20951 }
20958 {
20961 tree a;
20967 /* CV qualifications for methods can never be deduced, they must
20968 match exactly. We need to check them explicitly here,
20969 because type_unification_real treats them as any other
20970 cv-qualified parameter. */
20972 && (!check_cv_quals_for_unify
21000 {
21012 }
21015 }
21018 /* Unify a pointer to member with a pointer to member function, which
21019 deduces the type of the member as a function type. */
21021 {
21022 /* Check top-level cv qualifiers */
21030 /* Determine the type of the function we are unifying against. */
21034 }
21053 /* Matched cases are handled by the ARG == PARM test above. */
21057 /* We might get a variable as a non-type template argument in parm if the
21058 corresponding parameter is type-dependent. Make any necessary
21059 adjustments based on whether arg is a reference. */
21063 {
21068 }
21069 /* Now use the normal expression code to check whether they match. */
21080 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21081 or UNDERLYING_TYPE nodes. */
21085 /* Unification fails if we hit an error node. */
21090 {
21100 }
21101 /* FALLTHRU */
21104 /* An unresolved overload is a nondeduced context. */
21108 expr:
21109 /* We must be looking at an expression. This can happen with
21110 something like:
21112 template <int I>
21113 void foo(S<I>, S<I + 2>);
21115 This is a "nondeduced context":
21117 [deduct.type]
21119 The nondeduced contexts are:
21121 --A type that is a template-id in which one or more of
21122 the template-arguments is an expression that references
21123 a template-parameter.
21125 In these cases, we assume deduction succeeded, but don't
21126 actually infer any unifications. */
21131 else
21133 }
21134 }
21135 #undef RECUR_AND_CHECK_FAILURE
21136 \f
21137 /* Note that DECL can be defined in this translation unit, if
21138 required. */
21140 static void
21142 {
21143 tree clone;
21147 }
21149 /* Called if RESULT is explicitly instantiated, or is a member of an
21150 explicitly instantiated class. */
21152 void
21154 {
21157 /* If this entity has already been written out, it's too late to
21158 make any modifications. */
21162 /* For anonymous namespace we don't need to do anything. */
21164 {
21167 }
21170 /* The TREE_PUBLIC flag for function declarations will have been
21171 set correctly by tsubst. */
21174 /* This might have been set by an earlier implicit instantiation. */
21179 else
21180 {
21183 /* Always make artificials weak. */
21186 /* For WIN32 we also want to put explicit instantiations in
21187 linkonce sections. */
21190 }
21192 /* If EXTERN_P, then this function will not be emitted -- unless
21193 followed by an explicit instantiation, at which point its linkage
21194 will be adjusted. If !EXTERN_P, then this function will be
21195 emitted here. In neither circumstance do we want
21196 import_export_decl to adjust the linkage. */
21198 }
21200 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21201 important template arguments. If any are missing, we check whether
21202 they're important by using error_mark_node for substituting into any
21203 args that were used for partial ordering (the ones between ARGS and END)
21204 and seeing if it bubbles up. */
21206 static bool
21208 {
21213 {
21216 }
21218 {
21222 }
21224 }
21226 /* Given two function templates PAT1 and PAT2, return:
21228 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21229 -1 if PAT2 is more specialized than PAT1.
21230 0 if neither is more specialized.
21232 LEN indicates the number of parameters we should consider
21233 (defaulted parameters should not be considered).
21235 The 1998 std underspecified function template partial ordering, and
21236 DR214 addresses the issue. We take pairs of arguments, one from
21237 each of the templates, and deduce them against each other. One of
21238 the templates will be more specialized if all the *other*
21239 template's arguments deduce against its arguments and at least one
21240 of its arguments *does* *not* deduce against the other template's
21241 corresponding argument. Deduction is done as for class templates.
21242 The arguments used in deduction have reference and top level cv
21243 qualifiers removed. Iff both arguments were originally reference
21244 types *and* deduction succeeds in both directions, an lvalue reference
21245 wins against an rvalue reference and otherwise the template
21246 with the more cv-qualified argument wins for that pairing (if
21247 neither is more cv-qualified, they both are equal). Unlike regular
21248 deduction, after all the arguments have been deduced in this way,
21249 we do *not* verify the deduced template argument values can be
21250 substituted into non-deduced contexts.
21252 The logic can be a bit confusing here, because we look at deduce1 and
21253 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21254 can find template arguments for pat1 to make arg1 look like arg2, that
21255 means that arg2 is at least as specialized as arg1. */
21257 int
21259 {
21272 /* Remove the this parameter from non-static member functions. If
21273 one is a non-static member function and the other is not a static
21274 member function, remove the first parameter from that function
21275 also. This situation occurs for operator functions where we
21276 locate both a member function (with this pointer) and non-member
21277 operator (with explicit first operand). */
21279 {
21284 }
21286 {
21289 {
21290 len--;
21292 }
21293 }
21295 /* If only one is a conversion operator, they are unordered. */
21299 /* Consider the return type for a conversion function */
21301 {
21304 len++;
21305 }
21307 processing_template_decl++;
21313 /* Stop when an ellipsis is seen. */
21315 {
21326 {
21327 /* When both arguments are pack expansions, we need only
21328 unify the patterns themselves. */
21332 /* This is the last comparison we need to do. */
21334 }
21336 /* DR 1847: If a particular P contains no template-parameters that
21337 participate in template argument deduction, that P is not used to
21338 determine the ordering. */
21344 {
21348 }
21351 {
21355 }
21361 {
21367 /* Setup the parameter vector, which contains only ARG1. */
21370 /* Setup the argument vector, which contains the remaining
21371 arguments. */
21380 /* We cannot deduce in the other direction, because ARG1 is
21381 a pack expansion but ARG2 is not. */
21383 }
21385 {
21391 /* Setup the parameter vector, which contains only ARG1. */
21394 /* Setup the argument vector, which contains the remaining
21395 arguments. */
21404 /* We cannot deduce in the other direction, because ARG2 is
21405 a pack expansion but ARG1 is not.*/
21407 }
21409 else
21410 {
21411 /* The normal case, where neither argument is a pack
21412 expansion. */
21419 }
21421 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21422 arg2, then arg2 is not as specialized as arg1. */
21428 /* "If, for a given type, deduction succeeds in both directions
21429 (i.e., the types are identical after the transformations above)
21430 and both P and A were reference types (before being replaced with
21431 the type referred to above):
21432 - if the type from the argument template was an lvalue reference and
21433 the type from the parameter template was not, the argument type is
21434 considered to be more specialized than the other; otherwise,
21435 - if the type from the argument template is more cv-qualified
21436 than the type from the parameter template (as described above),
21437 the argument type is considered to be more specialized than the other;
21438 otherwise,
21439 - neither type is more specialized than the other." */
21442 {
21444 {
21447 else
21449 }
21451 {
21456 }
21457 }
21460 /* We've failed to deduce something in either direction.
21461 These must be unordered. */
21464 next:
21468 /* We have already processed all of the arguments in our
21469 handing of the pack expansion type. */
21474 }
21476 /* "In most cases, all template parameters must have values in order for
21477 deduction to succeed, but for partial ordering purposes a template
21478 parameter may remain without a value provided it is not used in the
21479 types being used for partial ordering."
21481 Thus, if we are missing any of the targs1 we need to substitute into
21482 origs1, then pat2 is not as specialized as pat1. This can happen when
21483 there is a nondeduced context. */
21489 processing_template_decl--;
21491 /* If both deductions succeed, the partial ordering selects the more
21492 constrained template. */
21494 {
21499 }
21501 /* All things being equal, if the next argument is a pack expansion
21502 for one function but not for the other, prefer the
21503 non-variadic function. FIXME this is bogus; see c++/41958. */
21507 {
21510 }
21516 else
21518 }
21520 /* Determine which of two partial specializations of TMPL is more
21521 specialized.
21523 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21524 to the first partial specialization. The TREE_PURPOSE is the
21525 innermost set of template parameters for the partial
21526 specialization. PAT2 is similar, but for the second template.
21528 Return 1 if the first partial specialization is more specialized;
21529 -1 if the second is more specialized; 0 if neither is more
21530 specialized.
21532 See [temp.class.order] for information about determining which of
21533 two templates is more specialized. */
21535 static int
21537 {
21538 tree targs;
21547 /* Just like what happens for functions, if we are ordering between
21548 different template specializations, we may encounter dependent
21549 types in the arguments, and we need our dependency check functions
21550 to behave correctly. */
21554 {
21557 }
21561 {
21564 }
21567 /* If both deductions succeed, the partial ordering selects the more
21568 constrained template. */
21572 /* In the case of a tie where at least one of the templates
21573 has a parameter pack at the end, the template with the most
21574 non-packed parameters wins. */
21576 && any_deductions
21579 {
21585 /* We don't count the pack expansion at the end. */
21595 }
21598 }
21600 /* Return the template arguments that will produce the function signature
21601 DECL from the function template FN, with the explicit template
21602 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21603 also match. Return NULL_TREE if no satisfactory arguments could be
21604 found. */
21606 static tree
21608 {
21612 tree decl_arg_types;
21615 tree arg;
21619 /* Never do unification on the 'this' parameter. */
21640 }
21642 /* Return the innermost template arguments that, when applied to a partial
21643 specialization SPEC_TMPL of TMPL, yield the ARGS.
21645 For example, suppose we have:
21647 template <class T, class U> struct S {};
21648 template <class T> struct S<T*, int> {};
21650 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21651 partial specialization and the ARGS will be {double*, int}. The resulting
21652 vector will be {double}, indicating that `T' is bound to `double'. */
21654 static tree
21656 {
21658 tree spec_args
21661 tree deduced_args;
21662 tree innermost_deduced_args;
21666 {
21670 innermost_deduced_args);
21671 }
21672 else
21676 again:
21685 {
21687 {
21693 }
21695 }
21699 {
21702 }
21704 /* Verify that nondeduced template arguments agree with the type
21705 obtained from argument deduction.
21707 For example:
21709 struct A { typedef int X; };
21710 template <class T, class U> struct C {};
21711 template <class T> struct C<T, typename T::X> {};
21713 Then with the instantiation `C<A, int>', we can deduce that
21714 `T' is `A' but unify () does not check whether `typename T::X'
21715 is `int'. */
21726 /* We only need to check the innermost arguments; the other
21727 arguments will always agree. */
21732 /* Now that we have bindings for all of the template arguments,
21733 ensure that the arguments deduced for the template template
21734 parameters have compatible template parameter lists. See the use
21735 of template_template_parm_bindings_ok_p in fn_type_unification
21736 for more information. */
21741 }
21743 // Compare two function templates T1 and T2 by deducing bindings
21744 // from one against the other. If both deductions succeed, compare
21745 // constraints to see which is more constrained.
21746 static int
21748 {
21753 {
21756 }
21759 {
21762 }
21764 // If both deductions succeed, then one may be more constrained.
21769 }
21771 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21772 Return the TREE_LIST node with the most specialized template, if
21773 any. If there is no most specialized template, the error_mark_node
21774 is returned.
21776 Note that this function does not look at, or modify, the
21777 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21778 returned is one of the elements of INSTANTIATIONS, callers may
21779 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21780 and retrieve it from the value returned. */
21782 tree
21784 {
21791 {
21797 {
21798 /* Equally specialized, move to next function. If there
21799 is no next function, nothing's most specialized. */
21804 }
21805 }
21808 /* Now verify that champ is better than everything earlier in the
21809 instantiation list. */
21812 {
21815 }
21816 }
21818 processing_template_decl--;
21824 }
21826 /* If DECL is a specialization of some template, return the most
21827 general such template. Otherwise, returns NULL_TREE.
21829 For example, given:
21831 template <class T> struct S { template <class U> void f(U); };
21833 if TMPL is `template <class U> void S<int>::f(U)' this will return
21834 the full template. This function will not trace past partial
21835 specializations, however. For example, given in addition:
21837 template <class T> struct S<T*> { template <class U> void f(U); };
21839 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21840 `template <class T> template <class U> S<T*>::f(U)'. */
21842 tree
21844 {
21846 {
21849 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21850 template friend, or a FIELD_DECL for a capture pack. */
21853 }
21855 /* Look for more and more general templates. */
21857 {
21858 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21859 (See cp-tree.h for details.) */
21868 /* Stop if we run into an explicitly specialized class template. */
21875 }
21878 }
21880 /* Return the most specialized of the template partial specializations
21881 which can produce TARGET, a specialization of some class or variable
21882 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21883 a TEMPLATE_DECL node corresponding to the partial specialization, while
21884 the TREE_PURPOSE is the set of template arguments that must be
21885 substituted into the template pattern in order to generate TARGET.
21887 If the choice of partial specialization is ambiguous, a diagnostic
21888 is issued, and the error_mark_node is returned. If there are no
21889 partial specializations matching TARGET, then NULL_TREE is
21890 returned, indicating that the primary template should be used. */
21892 static tree
21894 {
21896 tree t;
21897 tree champ;
21904 {
21908 }
21910 {
21913 }
21915 {
21919 }
21920 else
21925 /* For determining which partial specialization to use, only the
21926 innermost args are interesting. */
21928 {
21931 }
21934 {
21935 tree spec_args;
21939 {
21940 /* Substitute in the template args from the enclosing class. */
21944 }
21951 {
21955 /* Keep the candidate only if the constraints are satisfied,
21956 or if we're not compiling with concepts. */
21959 {
21962 }
21963 }
21964 }
21974 {
21977 ;
21978 else
21979 {
21981 {
21984 {
21987 }
21988 }
21990 }
21991 }
21995 {
21998 {
22001 }
22002 }
22005 {
22012 else
22016 {
22021 }
22024 }
22027 }
22029 /* Explicitly instantiate DECL. */
22031 void
22033 {
22038 /* An error occurred, for which grokdeclarator has already issued
22039 an appropriate message. */
22042 {
22045 }
22051 {
22052 /* There is an asymmetry here in the way VAR_DECLs and
22053 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22054 the latter, the DECL we get back will be marked as a
22055 template instantiation, and the appropriate
22056 DECL_TEMPLATE_INFO will be set up. This does not happen for
22057 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22058 should handle VAR_DECLs as it currently handles
22059 FUNCTION_DECLs. */
22061 {
22064 }
22067 {
22070 }
22072 {
22077 }
22078 }
22080 {
22083 }
22084 else
22087 /* Check for various error cases. Note that if the explicit
22088 instantiation is valid the RESULT will currently be marked as an
22089 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22090 until we get here. */
22093 {
22094 /* DR 259 [temp.spec].
22096 Both an explicit instantiation and a declaration of an explicit
22097 specialization shall not appear in a program unless the explicit
22098 instantiation follows a declaration of the explicit specialization.
22100 For a given set of template parameters, if an explicit
22101 instantiation of a template appears after a declaration of an
22102 explicit specialization for that template, the explicit
22103 instantiation has no effect. */
22105 }
22107 {
22108 /* [temp.spec]
22110 No program shall explicitly instantiate any template more
22111 than once.
22113 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22114 the first instantiation was `extern' and the second is not,
22115 and EXTERN_P for the opposite case. */
22118 /* If an "extern" explicit instantiation follows an ordinary
22119 explicit instantiation, the template is instantiated. */
22122 }
22124 {
22127 }
22129 {
22132 }
22135 ;
22137 {
22140 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22143 }
22144 else
22152 }
22154 static void
22156 {
22162 {
22165 }
22166 }
22168 /* Called from do_type_instantiation through binding_table_foreach to
22169 do recursive instantiation for the type bound in ENTRY. */
22170 static void
22172 {
22178 }
22180 /* Called from do_type_instantiation to instantiate a member
22181 (a member function or a static member variable) of an
22182 explicitly instantiated class template. */
22183 static void
22185 {
22190 }
22192 /* Perform an explicit instantiation of template class T. STORAGE, if
22193 non-null, is the RID for extern, inline or static. COMPLAIN is
22194 nonzero if this is called from the parser, zero if called recursively,
22195 since the standard is unclear (as detailed below). */
22197 void
22199 {
22209 {
22210 tree tmpl =
22214 else
22217 }
22222 {
22225 t);
22227 }
22230 {
22232 {
22234 {
22237 "ISO C++ 1998 forbids the use of %<extern%> on "
22239 }
22240 else
22242 "ISO C++ forbids the use of %qE"
22244 }
22252 else
22253 {
22255 storage);
22257 }
22258 }
22261 {
22262 /* DR 259 [temp.spec].
22264 Both an explicit instantiation and a declaration of an explicit
22265 specialization shall not appear in a program unless the explicit
22266 instantiation follows a declaration of the explicit specialization.
22268 For a given set of template parameters, if an explicit
22269 instantiation of a template appears after a declaration of an
22270 explicit specialization for that template, the explicit
22271 instantiation has no effect. */
22273 }
22275 {
22276 /* [temp.spec]
22278 No program shall explicitly instantiate any template more
22279 than once.
22281 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22282 instantiation was `extern'. If EXTERN_P then the second is.
22283 These cases are OK. */
22290 /* If we've already instantiated the template, just return now. */
22293 }
22301 {
22302 tree tmp;
22304 /* In contrast to implicit instantiation, where only the
22305 declarations, and not the definitions, of members are
22306 instantiated, we have here:
22308 [temp.explicit]
22310 The explicit instantiation of a class template specialization
22311 implies the instantiation of all of its members not
22312 previously explicitly specialized in the translation unit
22313 containing the explicit instantiation.
22315 Of course, we can't instantiate member template classes, since
22316 we don't have any arguments for them. Note that the standard
22317 is unclear on whether the instantiation of the members are
22318 *explicit* instantiations or not. However, the most natural
22319 interpretation is that it should be an explicit instantiation. */
22335 }
22336 }
22338 /* Given a function DECL, which is a specialization of TMPL, modify
22339 DECL to be a re-instantiation of TMPL with the same template
22340 arguments. TMPL should be the template into which tsubst'ing
22341 should occur for DECL, not the most general template.
22343 One reason for doing this is a scenario like this:
22345 template <class T>
22346 void f(const T&, int i);
22348 void g() { f(3, 7); }
22350 template <class T>
22351 void f(const T& t, const int i) { }
22353 Note that when the template is first instantiated, with
22354 instantiate_template, the resulting DECL will have no name for the
22355 first parameter, and the wrong type for the second. So, when we go
22356 to instantiate the DECL, we regenerate it. */
22358 static void
22360 {
22361 /* The arguments used to instantiate DECL, from the most general
22362 template. */
22363 tree code_pattern;
22367 /* Make sure that we can see identifiers, and compute access
22368 correctly. */
22372 {
22373 tree decl_parm;
22374 tree pattern_parm;
22375 tree specs;
22389 specs);
22391 /* Merge parameter declarations. */
22394 pattern_parm
22398 {
22399 tree parm_type;
22400 tree attributes;
22405 NULL_TREE);
22411 {
22414 }
22417 }
22418 /* Merge any parameters that match with the function parameter
22419 pack. */
22421 {
22423 tree expanded_types;
22424 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22425 the parameters in this function parameter pack. */
22430 {
22431 tree parm_type;
22432 tree attributes;
22435 /* Rename the parameter to include the index. */
22444 {
22447 }
22449 }
22450 }
22451 /* Merge additional specifiers from the CODE_PATTERN. */
22455 }
22457 {
22465 }
22466 else
22470 }
22472 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22473 substituted to get DECL. */
22475 tree
22477 {
22480 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22481 for the instantiation. This is not always the most general
22482 template. Consider, for example:
22484 template <class T>
22485 struct S { template <class U> void f();
22486 template <> void f<int>(); };
22488 and an instantiation of S<double>::f<int>. We want TD to be the
22489 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22491 more general template. */
22493 /* We must also deal with friend templates. Given:
22495 template <class T> struct S {
22496 template <class U> friend void f() {};
22497 };
22499 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22500 so far as the language is concerned, but that's still
22501 where we get the pattern for the instantiation from. On
22502 other hand, if the definition comes outside the class, say:
22504 template <class T> struct S {
22505 template <class U> friend void f();
22506 };
22507 template <class U> friend void f() {}
22509 we don't need to look any further. That's what the check for
22510 DECL_INITIAL is for. */
22514 {
22515 /* The present template, TD, should not be a definition. If it
22516 were a definition, we should be using it! Note that we
22517 cannot restructure the loop to just keep going until we find
22518 a template with a definition, since that might go too far if
22519 a specialization was declared, but not defined. */
22521 /* Fetch the more general template. */
22523 }
22526 }
22528 /* Returns true if we need to instantiate this template instance even if we
22529 know we aren't going to emit it. */
22531 bool
22533 {
22534 /* We always instantiate inline functions so that we can inline them. An
22535 explicit instantiation declaration prohibits implicit instantiation of
22536 non-inline functions. With high levels of optimization, we would
22537 normally inline non-inline functions -- but we're not allowed to do
22538 that for "extern template" functions. Therefore, we check
22539 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22543 /* And we need to instantiate static data members so that
22544 their initializers are available in integral constant
22545 expressions. */
22548 }
22550 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22551 instantiate it now, modifying TREE_TYPE (fn). */
22553 void
22555 {
22558 /* Don't instantiate a noexcept-specification from template context. */
22573 {
22577 {
22592 }
22593 else
22597 }
22600 {
22603 else
22605 }
22606 }
22608 /* Produce the definition of D, a _DECL generated from a template. If
22609 DEFER_OK is true, then we don't have to actually do the
22610 instantiation now; we just have to do it sometime. Normally it is
22611 an error if this is an explicit instantiation but D is undefined.
22612 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22613 instantiated class template. */
22615 tree
22617 {
22619 tree gen_args;
22620 tree args;
22621 tree td;
22622 tree code_pattern;
22623 tree spec;
22624 tree gen_tmpl;
22632 /* This function should only be used to instantiate templates for
22633 functions and static member variables. */
22636 /* A concept is never instantiated. */
22639 /* Variables are never deferred; if instantiation is required, they
22640 are instantiated right away. That allows for better code in the
22641 case that an expression refers to the value of the variable --
22642 if the variable has a constant value the referring expression can
22643 take advantage of that fact. */
22647 /* Don't instantiate cloned functions. Instead, instantiate the
22648 functions they cloned. */
22656 /* D has already been instantiated or explicitly specialized, so
22657 there's nothing for us to do here.
22659 It might seem reasonable to check whether or not D is an explicit
22660 instantiation, and, if so, stop here. But when an explicit
22661 instantiation is deferred until the end of the compilation,
22662 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22663 the instantiation. */
22666 /* Check to see whether we know that this template will be
22667 instantiated in some other file, as with "extern template"
22668 extension. */
22671 /* In general, we do not instantiate such templates. */
22679 /* We should already have the extra args. */
22682 /* And what's in the hash table should match D. */
22686 /* This needs to happen before any tsubsting. */
22692 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22693 for the instantiation. */
22698 {
22699 /* Look up an explicit specialization, if any. */
22703 {
22706 }
22707 }
22711 /* We should never be trying to instantiate a member of a class
22712 template or partial specialization. */
22717 /* In the case of a friend template whose definition is provided
22718 outside the class, we may have too many arguments. Drop the
22719 ones we don't need. The same is true for specializations. */
22720 args = get_innermost_template_args
22724 {
22730 }
22731 else
22732 {
22737 else
22739 }
22741 /* We may be in the middle of deferred access check. Disable it now. */
22744 /* Unless an explicit instantiation directive has already determined
22745 the linkage of D, remember that a definition is available for
22746 this entity. */
22756 /* If D is a member of an explicitly instantiated class template,
22757 and no definition is available, treat it like an implicit
22758 instantiation. */
22761 {
22762 /* Leave linkage flags alone on instantiations with anonymous
22763 visibility. */
22765 {
22768 }
22770 }
22772 /* Defer all other templates, unless we have been explicitly
22773 forbidden from doing so. */
22775 template. */
22776 ! pattern_defined
22777 /* If it's OK to postpone instantiation, do so. */
22778 || defer_ok
22779 /* If this is a static data member that will be defined
22780 elsewhere, we don't want to instantiate the entire data
22781 member, but we do want to instantiate the initializer so that
22782 we can substitute that elsewhere. */
22784 /* Handle here a deleted function too, avoid generating
22785 its body (c++/61080). */
22787 {
22788 /* The definition of the static data member is now required so
22789 we must substitute the initializer. */
22793 {
22794 tree ns;
22795 tree init;
22804 args,
22807 /* If instantiating the initializer involved instantiating this
22808 again, don't call cp_finish_decl twice. */
22810 {
22811 /* Make sure the initializer is still constant, in case of
22812 circular dependency (template/instantiate6.C). */
22813 const_init
22817 LOOKUP_ONLYCONVERTING);
22818 }
22822 }
22824 /* We restore the source position here because it's used by
22825 add_pending_template. */
22831 /* [temp.explicit]
22833 The definition of a non-exported function template, a
22834 non-exported member function template, or a non-exported
22835 member function or static data member of a class template
22836 shall be present in every translation unit in which it is
22837 explicitly instantiated. */
22841 /* If we're in unevaluated context, we just wanted to get the
22842 constant value; this isn't an odr use, so don't queue
22843 a full instantiation. */
22846 /* ??? Historically, we have instantiated inline functions, even
22847 when marked as "extern template". */
22851 }
22852 /* Tell the repository that D is available in this translation unit
22853 -- and see if it is supposed to be instantiated here. */
22855 {
22856 /* In a PCH file, despite the fact that the repository hasn't
22857 requested instantiation in the PCH it is still possible that
22858 an instantiation will be required in a file that includes the
22859 PCH. */
22862 /* Instantiate inline functions so that the inliner can do its
22863 job, even though we'll not be emitting a copy of this
22864 function. */
22867 }
22870 tree fn_context;
22881 else
22882 {
22886 }
22888 /* Mark D as instantiated so that recursive calls to
22889 instantiate_decl do not try to instantiate it again. */
22892 /* Regenerate the declaration in case the template has been modified
22893 by a subsequent redeclaration. */
22896 /* We already set the file and line above. Reset them now in case
22897 they changed as a result of calling regenerate_decl_from_template. */
22901 {
22902 tree init;
22905 /* Clear out DECL_RTL; whatever was there before may not be right
22906 since we've reset the type of the declaration. */
22910 /* The initializer is placed in DECL_INITIAL by
22911 regenerate_decl_from_template so we don't need to
22912 push/pop_access_scope again here. Pull it out so that
22913 cp_finish_decl can process it. */
22918 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22919 initializer. That function will defer actual emission until
22920 we have a chance to determine linkage. */
22923 /* Enter the scope of D so that access-checking works correctly. */
22936 }
22940 {
22942 tree tmpl_parm;
22943 tree spec_parm;
22947 /* Save away the current list, in case we are instantiating one
22948 template from within the body of another. */
22951 /* Set up the list of local specializations. */
22954 /* Set up context. */
22958 else
22959 {
22961 {
22962 /* When instantiating a lambda's templated function
22963 operator, we need to push the non-lambda class scope
22964 of the lambda itself so that the nested function
22965 stack is sufficiently correct to deal with this
22966 capture. */
22968 do
22973 }
22975 }
22977 /* Some typedefs referenced from within the template code need to be
22978 access checked at template instantiation time, i.e now. These
22979 types were added to the template at parsing time. Let's get those
22980 and perform the access checks then. */
22982 args);
22984 /* Create substitution entries for the parameters. */
22988 {
22992 }
22994 {
22996 {
22999 }
23000 else
23001 {
23002 /* Register the (value) argument pack as a specialization of
23003 TMPL_PARM, then move on. */
23006 }
23007 }
23010 /* Substitute into the body of the function. */
23014 else
23015 {
23020 /* Set the current input_location to the end of the function
23021 so that finish_function knows where we are. */
23022 input_location
23025 /* Remember if we saw an infinite loop in the template. */
23026 current_function_infinite_loop
23028 }
23030 /* We don't need the local specializations any more. */
23034 /* Finish the function. */
23038 else
23039 {
23042 }
23048 }
23050 /* We're not deferring instantiation any more. */
23055 else
23061 out:
23070 }
23072 /* Run through the list of templates that we wish we could
23073 instantiate, and instantiate any we can. RETRIES is the
23074 number of times we retry pending template instantiation. */
23076 void
23078 {
23082 /* Instantiating templates may trigger vtable generation. This in turn
23083 may require further template instantiations. We place a limit here
23084 to avoid infinite loop. */
23086 {
23090 "template instantiation depth exceeds maximum of %d"
23091 " instantiating %q+D, possibly from virtual table generation"
23095 /* Pretend that we defined it. */
23098 }
23100 do
23101 {
23106 {
23111 {
23112 tree fn;
23115 {
23119 fn;
23127 }
23130 }
23131 else
23132 {
23135 {
23136 instantiation
23142 }
23146 }
23149 /* If INSTANTIATION has been instantiated, then we don't
23150 need to consider it again in the future. */
23152 else
23153 {
23156 }
23159 }
23161 }
23165 }
23167 /* Substitute ARGVEC into T, which is a list of initializers for
23168 either base class or a non-static data member. The TREE_PURPOSEs
23169 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23170 instantiate_decl. */
23172 static tree
23174 {
23178 {
23179 tree decl;
23180 tree init;
23186 {
23187 tree expr;
23188 tree arg;
23190 /* Expand the base class expansion type into separate base
23191 classes. */
23193 tf_warning_or_error,
23194 NULL_TREE);
23198 /* We'll be building separate TREE_LISTs of arguments for
23199 each base. */
23205 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23206 expand each argument in the TREE_VALUE of t. */
23213 /* VOID_TYPE_NODE is used to indicate
23214 value-initialization. */
23215 {
23218 }
23219 else
23220 {
23221 /* Substitute parameter packs into each argument in the
23222 TREE_LIST. */
23225 {
23226 tree expanded_exprs;
23228 /* Expand the argument. */
23230 expanded_exprs
23232 tf_warning_or_error,
23233 NULL_TREE);
23237 /* Prepend each of the expanded expressions to the
23238 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23240 {
23245 }
23246 }
23249 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23250 since we built them backwards. */
23252 {
23255 }
23256 }
23257 }
23260 {
23262 {
23266 }
23267 else
23268 {
23269 tree tmp;
23284 /* If we had an initializer but it instantiated to nothing,
23285 value-initialize the object. This will only occur when
23286 the initializer was a pack expansion where the parameter
23287 packs used in that expansion were of length zero. */
23290 }
23293 {
23297 }
23298 }
23299 }
23301 }
23303 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23305 static void
23307 {
23312 else
23314 }
23316 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23317 is the instantiation (which should have been created with
23318 start_enum) and ARGS are the template arguments to use. */
23320 static void
23322 {
23323 tree e;
23329 {
23330 tree value;
23331 tree decl;
23334 /* Note that in a template enum, the TREE_VALUE is the
23335 CONST_DECL, not the corresponding INTEGER_CST. */
23340 /* Give this enumeration constant the correct access. */
23343 /* Actually build the enumerator itself. Here we're assuming that
23344 enumerators can't have dependent attributes. */
23347 }
23357 }
23359 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23360 its type -- but without substituting the innermost set of template
23361 arguments. So, innermost set of template parameters will appear in
23362 the type. */
23364 tree
23366 {
23367 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23369 }
23371 /* Return truthvalue if we're processing a template different from
23372 the last one involved in diagnostics. */
23373 bool
23375 {
23377 }
23379 /* Remember current template involved in diagnostics. */
23380 void
23382 {
23384 }
23388 {
23390 }
23392 /* Return TRUE if current_function_decl is being instantiated, false
23393 otherwise. */
23395 bool
23397 {
23400 }
23402 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23403 type. Return zero for ok, nonzero for disallowed. Issue error and
23404 warning messages under control of COMPLAIN. */
23406 static int
23408 {
23423 /* A bound template template parm could later be instantiated to have a valid
23424 nontype parm type via an alias template. */
23430 {
23433 else
23435 type);
23436 }
23438 }
23440 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23441 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23443 static bool
23445 {
23446 tree scope;
23448 /* [temp.dep.type]
23450 A type is dependent if it is:
23452 -- a template parameter. Template template parameters are types
23453 for us (since TYPE_P holds true for them) so we handle
23454 them here. */
23458 /* -- a qualified-id with a nested-name-specifier which contains a
23459 class-name that names a dependent type or whose unqualified-id
23460 names a dependent type. */
23464 /* An alias template specialization can be dependent even if the
23465 resulting type is not. */
23469 /* -- a cv-qualified type where the cv-unqualified type is
23470 dependent.
23471 No code is necessary for this bullet; the code below handles
23472 cv-qualified types, and we don't want to strip aliases with
23473 TYPE_MAIN_VARIANT because of DR 1558. */
23474 /* -- a compound type constructed from any dependent type. */
23484 {
23485 tree arg_type;
23490 arg_type;
23495 {
23496 /* A value-dependent noexcept-specifier makes the type dependent. */
23501 }
23503 }
23504 /* -- an array type constructed from any dependent type or whose
23505 size is specified by a constant expression that is
23506 value-dependent.
23508 We checked for type- and value-dependence of the bounds in
23509 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23511 {
23516 }
23518 /* -- a template-id in which either the template name is a template
23519 parameter ... */
23522 /* ... or any of the template arguments is a dependent type or
23523 an expression that is type-dependent or value-dependent. */
23525 && (any_dependent_template_arguments_p
23529 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23530 dependent; if the argument of the `typeof' expression is not
23531 type-dependent, then it should already been have resolved. */
23537 /* A template argument pack is dependent if any of its packed
23538 arguments are. */
23540 {
23546 }
23548 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23549 be template parameters. */
23556 /* The standard does not specifically mention types that are local
23557 to template functions or local classes, but they should be
23558 considered dependent too. For example:
23560 template <int I> void f() {
23561 enum E { a = I };
23562 S<sizeof (E)> s;
23563 }
23565 The size of `E' cannot be known until the value of `I' has been
23566 determined. Therefore, `E' must be considered dependent. */
23570 /* Don't use type_dependent_expression_p here, as it can lead
23571 to infinite recursion trying to determine whether a lambda
23572 nested in a lambda is dependent (c++/47687). */
23576 && (any_dependent_template_arguments_p
23580 /* Other types are non-dependent. */
23582 }
23584 /* Returns TRUE if TYPE is dependent, in the sense of
23585 [temp.dep.type]. Note that a NULL type is considered dependent. */
23587 bool
23589 {
23590 /* If there are no template parameters in scope, then there can't be
23591 any dependent types. */
23593 {
23594 /* If we are not processing a template, then nobody should be
23595 providing us with a dependent type. */
23599 }
23601 /* If the type is NULL, we have not computed a type for the entity
23602 in question; in that case, the type is dependent. */
23606 /* Erroneous types can be considered non-dependent. */
23610 /* Getting here with global_type_node means we improperly called this
23611 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23614 /* If we have not already computed the appropriate value for TYPE,
23615 do so now. */
23617 {
23620 }
23623 }
23625 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23626 lookup. In other words, a dependent type that is not the current
23627 instantiation. */
23629 bool
23631 {
23634 }
23636 /* T is a SCOPE_REF; return whether we need to consider it
23637 instantiation-dependent so that we can check access at instantiation
23638 time even though we know which member it resolves to. */
23640 static bool
23642 {
23648 else
23650 }
23652 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23653 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23654 expression. */
23656 /* Note that this predicate is not appropriate for general expressions;
23657 only constant expressions (that satisfy potential_constant_expression)
23658 can be tested for value dependence. */
23660 bool
23662 {
23666 /* A name declared with a dependent type. */
23671 {
23673 /* A dependent member function of the current instantiation. */
23677 /* A dependent member function of the current instantiation. */
23684 /* A name that has not been looked up -- must be dependent. */
23688 /* A non-type template parm. */
23692 /* A non-type template parm. */
23698 /* A constant with literal type and is initialized
23699 with an expression that is value-dependent.
23701 Note that a non-dependent parenthesized initializer will have
23702 already been replaced with its constant value, so if we see
23703 a TREE_LIST it must be dependent. */
23707 /* cp_finish_decl doesn't fold reference initializers. */
23713 {
23717 }
23725 /* These expressions are value-dependent if the type to which
23726 the cast occurs is dependent or the expression being casted
23727 is value-dependent. */
23728 {
23734 /* A functional cast has a list of operands. */
23737 {
23738 /* If there are no operands, it must be an expression such
23739 as "int()". This should not happen for aggregate types
23740 because it would form non-constant expressions. */
23745 }
23751 }
23756 /* FALLTHRU */
23759 /* A `sizeof' expression is value-dependent if the operand is
23760 type-dependent or is a pack expansion. */
23769 /* An 'encode' expression is value-dependent if the operand is
23770 type-dependent. */
23779 /* All instantiation-dependent expressions should also be considered
23780 value-dependent. */
23788 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23789 is value-dependent. */
23790 {
23799 }
23802 {
23806 }
23817 {
23821 }
23824 /* Treat all requires-expressions as value-dependent so
23825 we don't try to fold them. */
23832 {
23839 {
23841 /* In a call to a constexpr member function, look through the
23842 implicit ADDR_EXPR on the object argument so that it doesn't
23843 cause the call to be considered value-dependent. We also
23844 look through it in potential_constant_expression. */
23851 }
23853 }
23856 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23857 type-dependent. */
23862 {
23864 tree val;
23871 }
23874 /* Treat a GNU statement expression as dependent to avoid crashing
23875 under instantiate_non_dependent_expr; it can't be constant. */
23879 /* A constant expression is value-dependent if any subexpression is
23880 value-dependent. */
23882 {
23889 {
23893 {
23896 /* In some cases, some of the operands may be missing.
23897 (For example, in the case of PREDECREMENT_EXPR, the
23898 amount to increment by may be missing.) That doesn't
23899 make the expression dependent. */
23902 }
23903 }
23907 }
23909 }
23911 /* The expression is not value-dependent. */
23913 }
23915 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23916 [temp.dep.expr]. Note that an expression with no type is
23917 considered dependent. Other parts of the compiler arrange for an
23918 expression with type-dependent subexpressions to have no type, so
23919 this function doesn't have to be fully recursive. */
23921 bool
23923 {
23930 /* An unresolved name is always dependent. */
23936 /* A fold expression is type-dependent. */
23943 /* Some expression forms are never type-dependent. */
23957 /* The types of these expressions depends only on the type to which
23958 the cast occurs. */
23967 /* The types of these expressions depends only on the type created
23968 by the expression. */
23971 {
23972 /* For NEW_EXPR tree nodes created inside a template, either
23973 the object type itself or a TREE_LIST may appear as the
23974 operand 1. */
23977 /* This is an array type. We need to check array dimensions
23978 as well. */
23980 || value_dependent_expression_p
23982 else
23984 }
23987 {
23991 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23992 contains an identifier associated by name lookup with one or more
23993 declarations declared with a dependent type, or...a
23994 nested-name-specifier or qualified-id that names a member of an
23995 unknown specialization. */
23998 }
24008 {
24009 tree elt;
24013 {
24016 }
24018 }
24020 /* A static data member of the current instantiation with incomplete
24021 array type is type-dependent, as the definition and specializations
24022 can have different bounds. */
24029 /* An array of unknown bound depending on a variadic parameter, eg:
24031 template<typename... Args>
24032 void foo (Args... args)
24033 {
24034 int arr[] = { args... };
24035 }
24037 template<int... vals>
24038 void bar ()
24039 {
24040 int arr[] = { vals... };
24041 }
24043 If the array has no length and has an initializer, it must be that
24044 we couldn't determine its length in cp_complete_array_type because
24045 it is dependent. */
24053 /* A function or variable template-id is type-dependent if it has any
24054 dependent template arguments. */
24058 {
24059 /* Consider the innermost template arguments, since those are the ones
24060 that come from the template-id; the template arguments for the
24061 enclosing class do not make it type-dependent unless they are used in
24062 the type of the decl. */
24064 && (any_dependent_template_arguments_p
24068 /* Otherwise, if the decl isn't from a dependent scope, it can't be
24069 type-dependent. Checking this is important for functions with auto
24070 return type, which looks like a dependent type. */
24077 {
24081 }
24082 }
24084 /* Always dependent, on the number of arguments if nothing else. */
24089 {
24094 {
24100 }
24101 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24106 {
24111 }
24114 {
24121 }
24131 }
24135 /* Dependent type attributes might not have made it from the decl to
24136 the type yet. */
24142 }
24144 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24145 type-dependent if the expression refers to a member of the current
24146 instantiation and the type of the referenced member is dependent, or the
24147 class member access expression refers to a member of an unknown
24148 specialization.
24150 This function returns true if the OBJECT in such a class member access
24151 expression is of an unknown specialization. */
24153 bool
24155 {
24156 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24157 dependent. */
24162 }
24164 /* walk_tree callback function for instantiation_dependent_expression_p,
24165 below. Returns non-zero if a dependent subexpression is found. */
24167 static tree
24170 {
24172 {
24173 /* We don't have to worry about decltype currently because decltype
24174 of an instantiation-dependent expr is a dependent type. This
24175 might change depending on the resolution of DR 1172. */
24178 }
24181 {
24182 /* Don't treat an argument list as dependent just because it has no
24183 TREE_TYPE. */
24191 /* Handle expressions with type operands. */
24196 {
24201 {
24204 else
24205 {
24208 }
24209 }
24211 }
24215 /* In a template, finish_class_member_access_expr creates a
24216 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24217 type-dependent, so that we can check access control at
24218 instantiation time (PR 42277). See also Core issue 1273. */
24225 else
24228 /* Treat statement-expressions as dependent. */
24232 /* Treat requires-expressions as dependent. */
24237 /* Treat calls to function concepts as dependent. */
24243 /* And variable concepts. */
24250 }
24254 else
24256 }
24258 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24259 sense defined by the ABI:
24261 "An expression is instantiation-dependent if it is type-dependent
24262 or value-dependent, or it has a subexpression that is type-dependent
24263 or value-dependent."
24265 Except don't actually check value-dependence for unevaluated expressions,
24266 because in sizeof(i) we don't care about the value of i. Checking
24267 type-dependence will in turn check value-dependence of array bounds/template
24268 arguments as needed. */
24270 bool
24272 {
24273 tree result;
24284 }
24286 /* As above, but also check value-dependence of the expression as a whole. */
24288 bool
24290 {
24293 }
24295 /* Like type_dependent_expression_p, but it also works while not processing
24296 a template definition, i.e. during substitution or mangling. */
24298 bool
24300 {
24306 }
24308 /* Returns TRUE if ARGS contains a type-dependent expression. */
24310 bool
24312 {
24314 tree arg;
24317 {
24320 }
24322 }
24324 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24325 expressions) contains any type-dependent expressions. */
24327 bool
24329 {
24335 }
24337 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24338 expressions) contains any value-dependent expressions. */
24340 bool
24342 {
24348 }
24350 /* Returns TRUE if the ARG (a template argument) is dependent. */
24352 bool
24354 {
24358 /* Assume a template argument that was wrongly written by the user
24359 is dependent. This is consistent with what
24360 any_dependent_template_arguments_p [that calls this function]
24361 does. */
24371 {
24374 /* A member template of a dependent class is not necessarily
24375 type-dependent, but it is a dependent template argument because it
24376 will be a member of an unknown specialization to that template. */
24379 }
24381 {
24385 {
24388 }
24391 }
24394 else
24397 }
24399 /* Returns true if ARGS (a collection of template arguments) contains
24400 any types that require structural equality testing. */
24402 bool
24404 {
24414 {
24417 {
24423 {
24424 /* Look inside the argument pack. */
24427 }
24430 {
24443 }
24444 }
24445 }
24448 }
24450 /* Returns true if ARGS (a collection of template arguments) contains
24451 any dependent arguments. */
24453 bool
24455 {
24465 {
24470 }
24473 }
24475 /* Returns TRUE if the template TMPL is type-dependent. */
24477 bool
24479 {
24481 {
24486 }
24488 /* Template template parameters are dependent. */
24492 /* So are names that have not been looked up. */
24496 }
24498 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24500 bool
24502 {
24505 }
24507 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24508 are dependent. */
24510 bool
24512 {
24519 {
24541 {
24545 }
24549 {
24553 {
24558 }
24559 }
24560 }
24563 }
24565 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24566 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24567 no such TYPE can be found. Note that this function peers inside
24568 uninstantiated templates and therefore should be used only in
24569 extremely limited situations. ONLY_CURRENT_P restricts this
24570 peering to the currently open classes hierarchy (which is required
24571 when comparing types). */
24573 tree
24575 {
24576 tree scope;
24577 tree name;
24578 tree decl;
24580 tree pushed_scope;
24581 tree result;
24586 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24587 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24588 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24589 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24590 identifier of the TYPENAME_TYPE anymore.
24591 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24592 TYPENAME_TYPE instead, we avoid messing up with a possible
24593 typedef variant case. */
24596 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24597 it first before we can figure out what NAME refers to. */
24599 {
24601 /* Given a class template A with a dependent base with nested type C,
24602 typedef typename A::C::C C will land us here, as trying to resolve
24603 the initial A::C leads to the local C typedef, which leads back to
24604 A::C::C. So we break the recursion now. */
24606 else
24608 }
24609 /* If we don't know what SCOPE refers to, then we cannot resolve the
24610 TYPENAME_TYPE. */
24613 /* If this is a typedef, we don't want to look inside (c++/11987). */
24616 /* If SCOPE isn't the template itself, it will not have a valid
24617 TYPE_FIELDS list. */
24619 /* scope is either the template itself or a compatible instantiation
24620 like X<T>, so look up the name in the original template. */
24622 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24624 /* If scope has no fields, it can't be a current instantiation. Check this
24625 before currently_open_class to avoid infinite recursion (71515). */
24628 /* If the SCOPE is not the current instantiation, there's no reason
24629 to look inside it. */
24632 /* Enter the SCOPE so that name lookup will be resolved as if we
24633 were in the class definition. In particular, SCOPE will no
24634 longer be considered a dependent type. */
24636 /* Look up the declaration. */
24638 tf_warning_or_error);
24642 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24643 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24648 {
24652 }
24655 {
24656 tree tmpl;
24657 tree args;
24658 /* Obtain the template and the arguments. */
24661 /* Instantiate the template. */
24667 }
24669 /* Leave the SCOPE. */
24673 /* If we failed to resolve it, return the original typename. */
24677 /* If lookup found a typename type, resolve that too. */
24679 {
24680 /* Ill-formed programs can cause infinite recursion here, so we
24681 must catch that. */
24685 }
24687 /* Qualify the resulting type. */
24693 }
24695 /* EXPR is an expression which is not type-dependent. Return a proxy
24696 for EXPR that can be used to compute the types of larger
24697 expressions containing EXPR. */
24699 tree
24701 {
24702 tree inner_expr;
24704 /* When checking, try to get a constant value for all non-dependent
24705 expressions in order to expose bugs in *_dependent_expression_p
24706 and constexpr. This can affect code generation, see PR70704, so
24707 only do this for -fchecking=2. */
24710 /* Don't do this during nsdmi parsing as it can lead to
24711 unexpected recursive instantiations. */
24713 /* Don't do this during concept expansion either and for
24714 the same reason. */
24718 /* Preserve OVERLOADs; the functions must be available to resolve
24719 types. */
24730 /* There is no need to return a proxy for a variable. */
24733 /* Preserve string constants; conversions from string constants to
24734 "char *" are allowed, even though normally a "const char *"
24735 cannot be used to initialize a "char *". */
24738 /* Preserve void and arithmetic constants, as an optimization -- there is no
24739 reason to create a new node. */
24744 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24745 There is at least one place where we want to know that a
24746 particular expression is a throw-expression: when checking a ?:
24747 expression, there are special rules if the second or third
24748 argument is a throw-expression. */
24752 /* Don't wrap an initializer list, we need to be able to look inside. */
24756 /* Don't wrap a dummy object, we need to be able to test for it. */
24775 /* If the type is unknown, it can't really be non-dependent */
24778 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24780 }
24782 /* ARGS is a vector of expressions as arguments to a function call.
24783 Replace the arguments with equivalent non-dependent expressions.
24784 This modifies ARGS in place. */
24786 void
24788 {
24790 tree arg;
24793 {
24797 }
24798 }
24800 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24801 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24802 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24804 static tree
24806 {
24820 }
24822 tree
24824 {
24826 }
24828 tree
24830 {
24832 }
24834 /* Return a C++17 deduction placeholder for class template TMPL. */
24836 tree
24838 {
24842 }
24844 /* True iff T is a C++17 class template deduction placeholder. */
24846 bool
24848 {
24850 }
24852 /* Make a "constrained auto" type-specifier. This is an
24853 auto type with constraints that must be associated after
24854 deduction. The constraint is formed from the given
24855 CONC and its optional sequence of arguments, which are
24856 non-null if written as partial-concept-id. */
24858 tree
24860 {
24863 /* Build the constraint. */
24871 /* Our canonical type depends on the constraint. */
24874 /* Attach the constraint to the type declaration. */
24877 }
24879 /* Given type ARG, return std::initializer_list<ARG>. */
24881 static tree
24883 {
24887 {
24891 }
24897 }
24899 /* Replace auto in TYPE with std::initializer_list<auto>. */
24901 static tree
24903 {
24910 }
24912 /* Hash traits for hashing possibly constrained 'auto'
24913 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24916 {
24919 };
24921 /* Hash the 'auto' T. */
24923 inline hashval_t
24925 {
24927 /* Matching constrained-type-specifiers denote the same template
24928 parameter, so hash the constraint. */
24930 else
24931 /* But unconstrained autos are all separate, so just hash the pointer. */
24933 }
24935 /* Compare two 'auto's. */
24939 {
24946 /* Two unconstrained autos are distinct. */
24951 }
24953 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24954 constrained) auto, add it to the vector. */
24956 static int
24958 {
24961 {
24962 /* All the autos were built with index 0; fix that up now. */
24966 /* If this is a repeated constrained-type-specifier, use the index we
24967 chose before. */
24969 else
24970 {
24971 /* Otherwise this is new, so use the current count. */
24974 }
24976 }
24978 /* Always keep walking. */
24980 }
24982 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24983 says they can appear anywhere in the type. */
24985 static tree
24987 {
24996 {
25001 }
25004 }
25006 /* The stem for deduction guide names. */
25009 /* Return the name for a deduction guide for class template TMPL. */
25011 tree
25013 {
25024 }
25026 /* True if NAME is the name of a deduction guide. */
25028 bool
25030 {
25034 }
25036 /* True if FN is a deduction guide. */
25038 bool
25040 {
25045 }
25047 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25049 bool
25051 {
25058 }
25060 /* True if FN is a guide generated from a constructor template. */
25062 bool
25064 {
25069 {
25072 }
25074 }
25076 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25077 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25078 template parameter types. Note that the handling of template template
25079 parameters relies on current_template_parms being set appropriately for the
25080 new template. */
25082 static tree
25085 {
25088 tree newtype;
25091 {
25098 }
25099 else
25103 tree newdecl
25108 tree newidx;
25111 {
25121 {
25126 // First create a copy (ttargs) of tsubst_args with an
25127 // additional level for the template template parameter's own
25128 // template parameters (ttparms).
25129 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25137 // Substitute ttargs into ttparms to fix references to
25138 // other template parameters.
25140 complain);
25141 // Now substitute again with args based on tparms, to reduce
25142 // the level of the ttparms.
25145 complain);
25146 // Finally, tack the adjusted parms onto tparms.
25148 current_template_parms);
25150 }
25151 }
25152 else
25153 {
25155 tree newconst
25167 }
25170 }
25172 /* Returns a C++17 class deduction guide template based on the constructor
25173 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25174 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25176 static tree
25178 {
25182 location_t loc;
25185 {
25189 {
25192 }
25193 else
25203 }
25204 else
25205 {
25209 tree fn_tmpl;
25211 {
25214 }
25215 else
25219 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25220 fully specialized args for the enclosing class. Strip those off, as
25221 the deduction guide won't have those template parameters. */
25224 /* Discard the 'this' parameter. */
25232 {
25235 /* For a member template constructor, we need to flatten the two
25236 template parameter lists into one, and then adjust the function
25237 signature accordingly. This gets...complicated. */
25241 /* For a member template we should have two levels of parms/args, one
25242 for the class and one for the constructor. We stripped
25243 specialized args for further enclosing classes above. */
25247 /* Template args for translating references to the two-level template
25248 parameters into references to the one-level template parameters we
25249 are creating. */
25254 /* Template parms for the constructor template. */
25257 /* Template parms for the class template. */
25261 /* Template parms for the deduction guide start as a copy of the
25262 template parms for the class. We set current_template_parms for
25263 lookup_template_class_1. */
25269 /* Now we need to rewrite the constructor parms to append them to the
25270 class parms. */
25272 {
25287 }
25289 /* Now we have a final set of template parms to substitute into the
25290 function signature. */
25300 }
25301 }
25304 {
25305 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25309 }
25313 FUNCTION_DECL,
25330 }
25332 /* Deduce template arguments for the class template placeholder PTYPE for
25333 template TMPL based on the initializer INIT, and return the resulting
25334 type. */
25336 static tree
25338 tsubst_flags_t complain)
25339 {
25341 {
25342 /* We should have handled this in the caller. */
25348 }
25360 else
25371 /* Prune explicit deduction guides in copy-initialization context. */
25373 {
25379 {
25380 /* Found a nonconverting guide, prune the candidates. */
25387 }
25388 }
25393 {
25396 }
25400 // FIXME cache artificial deduction guides
25403 {
25408 else
25412 }
25415 {
25424 {
25429 else
25431 }
25432 }
25435 {
25437 " of %qT, as it has no non-explicit deduction guides or "
25440 }
25446 {
25452 }
25458 }
25460 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25461 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25463 tree
25465 {
25467 tf_warning_or_error,
25468 adc_unspecified);
25469 }
25471 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25472 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25473 The CONTEXT determines the context in which auto deduction is performed
25474 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25475 OUTER_TARGS are used during template argument deduction
25476 (context == adc_unify) to properly substitute the result, and is ignored
25477 in other contexts.
25479 For partial-concept-ids, extra args may be appended to the list of deduced
25480 template arguments prior to determining constraint satisfaction. */
25482 tree
25486 {
25487 tree targs;
25494 /* Defining a subset of type-dependent expressions that we can deduce
25495 from ahead of time isn't worth the trouble. */
25499 /* C++17 class template argument deduction. */
25503 /* Nothing we can do with this, even in deduction context. */
25506 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25507 with either a new invented type template parameter U or, if the
25508 initializer is a braced-init-list (8.5.4), with
25509 std::initializer_list<U>. */
25511 {
25516 else
25517 {
25519 {
25523 "for deduction to %<std::initializer_list%>, use copy-"
25525 }
25527 }
25528 }
25539 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25540 and initializer has array type, deduce cv-qualified array type. */
25542 complain);
25544 {
25553 {
25557 }
25558 }
25559 else
25560 {
25562 tree tparms;
25566 else
25567 {
25571 }
25578 {
25580 /* Try again at instantiation time. */
25584 /* If type is error_mark_node a diagnostic must have been
25585 emitted by now. Also, having a mention to '<type error>'
25586 in the diagnostic is not really useful to the user. */
25587 {
25591 else
25596 }
25598 }
25599 }
25601 /* Check any placeholder constraints against the deduced type. */
25604 {
25605 /* Use the deduced type to check the associated constraints. If we
25606 have a partial-concept-id, rebuild the argument list so that
25607 we check using the extra arguments. */
25611 {
25614 }
25615 else
25618 {
25620 {
25622 {
25640 }
25642 }
25644 }
25645 }
25651 }
25653 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25654 result. */
25656 tree
25658 {
25660 {
25666 /* In an abbreviated function template we didn't know we were dealing
25667 with a function template when we saw the auto return type, so update
25668 it to have the correct level. */
25670 }
25672 }
25674 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25675 'decltype(auto)' or a deduced class template. */
25677 bool
25679 {
25685 else
25687 }
25689 /* for_each_template_parm callback for type_uses_auto. */
25691 int
25693 {
25695 }
25697 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25698 a use of `auto'. Returns NULL_TREE otherwise. */
25700 tree
25702 {
25706 {
25707 /* The Concepts TS allows multiple autos in one type-specifier; just
25708 return the first one we find, do_auto_deduction will collect all of
25709 them. */
25713 else
25715 }
25716 else
25718 }
25720 /* For a given template T, return the vector of typedefs referenced
25721 in T for which access check is needed at T instantiation time.
25722 T is either a FUNCTION_DECL or a RECORD_TYPE.
25723 Those typedefs were added to T by the function
25724 append_type_to_template_for_access_check. */
25728 {
25729 tree ti;
25740 {
25745 }
25748 }
25750 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25751 tied to T. That list of typedefs will be access checked at
25752 T instantiation time.
25753 T is either a FUNCTION_DECL or a RECORD_TYPE.
25754 TYPE_DECL is a TYPE_DECL node representing a typedef.
25755 SCOPE is the scope through which TYPE_DECL is accessed.
25756 LOCATION is the location of the usage point of TYPE_DECL.
25758 This function is a subroutine of
25759 append_type_to_template_for_access_check. */
25761 static void
25763 tree type_decl,
25764 tree scope,
25765 location_t location)
25766 {
25767 qualified_typedef_usage_t typedef_usage;
25768 tree ti;
25775 && type_decl
25789 }
25791 /* Append TYPE_DECL to the template TEMPL.
25792 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25793 At TEMPL instanciation time, TYPE_DECL will be checked to see
25794 if it can be accessed through SCOPE.
25795 LOCATION is the location of the usage point of TYPE_DECL.
25797 e.g. consider the following code snippet:
25799 class C
25800 {
25801 typedef int myint;
25802 };
25804 template<class U> struct S
25805 {
25806 C::myint mi; // <-- usage point of the typedef C::myint
25807 };
25809 S<char> s;
25811 At S<char> instantiation time, we need to check the access of C::myint
25812 In other words, we need to check the access of the myint typedef through
25813 the C scope. For that purpose, this function will add the myint typedef
25814 and the scope C through which its being accessed to a list of typedefs
25815 tied to the template S. That list will be walked at template instantiation
25816 time and access check performed on each typedefs it contains.
25817 Note that this particular code snippet should yield an error because
25818 myint is private to C. */
25820 void
25822 tree type_decl,
25823 tree scope,
25824 location_t location)
25825 {
25831 /* Make sure we don't append the type to the template twice. */
25838 }
25840 /* Convert the generic type parameters in PARM that match the types given in the
25841 range [START_IDX, END_IDX) from the current_template_parms into generic type
25842 packs. */
25844 tree
25846 {
25857 {
25858 /* Create a distinct parameter pack type from the current parm and add it
25859 to the replacement args to tsubst below into the generic function
25860 parameter. */
25875 }
25881 /* If there are more levels then build up the replacement with the outer
25882 template parms. */
25886 replacement);
25889 }
25891 /* Entries in the decl_constraint hash table. */
25893 {
25894 tree decl;
25895 tree ci;
25896 };
25898 /* Hashing function and equality for constraint entries. */
25900 {
25902 {
25904 }
25907 {
25909 }
25910 };
25912 /* A mapping from declarations to constraint information. Note that
25913 both templates and their underlying declarations are mapped to the
25914 same constraint information.
25916 FIXME: This is defined in pt.c because garbage collection
25917 code is not being generated for constraint.cc. */
25921 /* Returns the template constraints of declaration T. If T is not
25922 constrained, return NULL_TREE. Note that T must be non-null. */
25924 tree
25926 {
25937 else
25939 }
25941 /* Associate the given constraint information CI with the declaration
25942 T. If T is a template, then the constraints are associated with
25943 its underlying declaration. Don't build associations if CI is
25944 NULL_TREE. */
25946 void
25948 {
25960 }
25962 /* Remove the associated constraints of the declaration T. */
25964 void
25966 {
25975 }
25977 /* Memoized satisfaction results for declarations. This
25978 maps the pair (constraint_info, arguments) to the result computed
25979 by constraints_satisfied_p. */
25982 {
25983 tree ci;
25984 tree args;
25985 tree result;
25986 };
25988 /* Hashing function and equality for constraint entries. */
25991 {
25993 {
25996 }
25999 {
26001 }
26002 };
26004 /* Memoized satisfaction results for concept checks. */
26007 {
26008 tree tmpl;
26009 tree args;
26010 tree result;
26011 };
26013 /* Hashing function and equality for constraint entries. */
26016 {
26018 {
26020 }
26023 {
26028 }
26029 };
26034 /* Search for a memoized satisfaction result. Returns one of the
26035 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26037 tree
26039 {
26044 else
26046 }
26048 /* Memoize the result of a satisfication test. Returns the saved result. */
26050 tree
26052 {
26059 }
26061 /* Search for a memoized satisfaction result for a concept. */
26063 tree
26065 {
26070 else
26072 }
26074 /* Memoize the result of a concept check. Returns the saved result. */
26076 tree
26078 {
26085 }
26089 /* Returns a prior concept specialization. This returns the substituted
26090 and normalized constraints defined by the concept. */
26092 tree
26094 {
26099 else
26101 }
26103 /* Save a concept expansion for later. */
26105 tree
26107 {
26114 }
26116 static hashval_t
26118 {
26127 }
26129 /* Compare the constraints of two subsumption entries. The LEFT1 and
26130 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26131 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26133 static bool
26135 {
26143 }
26145 /* Key/value pair for learning and memoizing subsumption results. This
26146 associates a pair of check constraints (including arguments) with
26147 a boolean value indicating the result. */
26150 {
26151 tree t1;
26152 tree t2;
26154 };
26156 /* Hashing function and equality for constraint entries. */
26159 {
26161 {
26163 }
26166 {
26171 }
26172 };
26176 /* Search for a previously cached subsumption result. */
26180 {
26185 else
26187 }
26189 /* Save a subsumption result. */
26191 bool
26193 {
26200 }
26202 /* Set up the hash table for constraint association. */
26204 void
26206 {
26215 }
26217 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26218 0..N-1. */
26220 void
26222 {
26225 integer_type_node,
26226 NULL_TREE),
26230 }
26232 /* Set up the hash tables for template instantiations. */
26234 void
26236 {
26242 }
26244 /* Print stats about the template hash tables for -fstats. */
26246 void
26248 {
26257 }