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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;
6434 /* Detect immediately string literals as invalid non-type argument.
6435 This special-case is not needed for correctness (we would easily
6436 catch this later), but only to provide better diagnostic for this
6437 common user mistake. As suggested by DR 100, we do not mention
6438 linkage issues in the diagnostic as this is not the point. */
6439 /* FIXME we're making this OK. */
6441 {
6447 }
6449 /* Add the ADDR_EXPR now for the benefit of
6450 value_dependent_expression_p. */
6453 {
6457 }
6459 /* If we are in a template, EXPR may be non-dependent, but still
6460 have a syntactic, rather than semantic, form. For example, EXPR
6461 might be a SCOPE_REF, rather than the VAR_DECL to which the
6462 SCOPE_REF refers. Preserving the qualifying scope is necessary
6463 so that access checking can be performed when the template is
6464 instantiated -- but here we need the resolved form so that we can
6465 convert the argument. */
6478 else
6481 /* If the argument is non-dependent, perform any conversions in
6482 non-dependent context as well. */
6490 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6491 to a non-type argument of "nullptr". */
6495 /* In C++11, integral or enumeration non-type template arguments can be
6496 arbitrary constant expressions. Pointer and pointer to
6497 member arguments can be general constant expressions that evaluate
6498 to a null value, but otherwise still need to be of a specific form. */
6500 {
6502 /* A PTRMEM_CST is already constant, and a valid template
6503 argument for a parameter of pointer to member type, we just want
6504 to leave it in that form rather than lower it to a
6509 {
6513 {
6517 }
6518 }
6520 {
6525 }
6526 }
6528 /* HACK: Due to double coercion, we can get a
6529 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6530 which is the tree that we built on the first call (see
6531 below when coercing to reference to object or to reference to
6532 function). We just strip everything and get to the arg.
6533 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6534 for examples. */
6536 {
6542 {
6543 /* ??? Maybe we could use convert_from_reference here, but we
6544 would need to relax its constraints because the NOP_EXPR
6545 could actually change the type to something more cv-qualified,
6546 and this is not folded by convert_from_reference. */
6551 && (same_type_ignoring_top_level_qualifiers_p
6554 {
6557 }
6558 }
6559 }
6561 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6562 parameter is a pointer to object, through decay and
6563 qualification conversion. Let's strip everything. */
6565 {
6570 {
6571 /* Skip the ADDR_EXPR only if it is part of the decay for
6572 an array. Otherwise, it is part of the original argument
6573 in the source code. */
6578 }
6579 }
6581 /* [temp.arg.nontype]/5, bullet 1
6583 For a non-type template-parameter of integral or enumeration type,
6584 integral promotions (_conv.prom_) and integral conversions
6585 (_conv.integral_) are applied. */
6587 {
6596 /* Notice that there are constant expressions like '4 % 0' which
6597 do not fold into integer constants. */
6600 {
6602 {
6613 /* else cxx_constant_value complained but gave us
6614 a real constant, so go ahead. */
6616 }
6617 else
6619 }
6621 /* Avoid typedef problems. */
6624 }
6625 /* [temp.arg.nontype]/5, bullet 2
6627 For a non-type template-parameter of type pointer to object,
6628 qualification conversions (_conv.qual_) and the array-to-pointer
6629 conversion (_conv.array_) are applied. */
6631 {
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 ;
6653 {
6655 {
6658 "because %qD is a variable, not the address of "
6661 }
6663 {
6669 }
6670 /* Other values, like integer constants, might be valid
6671 non-type arguments of some other type. */
6673 }
6674 else
6675 {
6676 tree decl;
6681 {
6686 }
6688 {
6694 }
6697 {
6702 }
6703 /* C++17: For a non-type template-parameter of reference or pointer
6704 type, the value of the constant expression shall not refer to (or
6705 for a pointer type, shall not be the address of):
6706 * a subobject (4.5),
6707 * a temporary object (15.2),
6708 * a string literal (5.13.5),
6709 * the result of a typeid expression (8.2.8), or
6710 * a predefined __func__ variable (11.4.1). */
6712 {
6715 decl);
6717 }
6721 {
6726 }
6728 {
6732 decl);
6734 }
6735 }
6744 }
6745 /* [temp.arg.nontype]/5, bullet 3
6747 For a non-type template-parameter of type reference to object, no
6748 conversions apply. The type referred to by the reference may be more
6749 cv-qualified than the (otherwise identical) type of the
6750 template-argument. The template-parameter is bound directly to the
6751 template-argument, which must be an lvalue. */
6753 {
6755 expr_type))
6759 {
6764 }
6767 {
6772 }
6774 /* [temp.arg.nontype]/1
6776 A template-argument for a non-type, non-template template-parameter
6777 shall be one of: [...]
6779 -- the address of an object or function with external linkage. */
6782 {
6785 {
6788 "because a reference variable does not have a constant "
6791 }
6792 }
6796 /* OK, dependent reference. We don't want to ask whether a DECL is
6798 else
6799 {
6801 {
6807 }
6809 /* DR 1155 allows internal linkage in C++11 and up. */
6812 {
6818 }
6821 }
6825 }
6826 /* [temp.arg.nontype]/5, bullet 4
6828 For a non-type template-parameter of type pointer to function, only
6829 the function-to-pointer conversion (_conv.func_) is applied. If the
6830 template-argument represents a set of overloaded functions (or a
6831 pointer to such), the matching function is selected from the set
6832 (_over.over_). */
6834 {
6835 /* If the argument is a template-id, we might not have enough
6836 context information to decay the pointer. */
6838 {
6842 }
6845 /* Null pointer values are OK in C++11. */
6851 }
6852 /* [temp.arg.nontype]/5, bullet 5
6854 For a non-type template-parameter of type reference to function, no
6855 conversions apply. If the template-argument represents a set of
6856 overloaded functions, the matching function is selected from the set
6857 (_over.over_). */
6859 {
6861 {
6863 {
6868 }
6870 }
6875 }
6876 /* [temp.arg.nontype]/5, bullet 6
6878 For a non-type template-parameter of type pointer to member function,
6879 no conversions apply. If the template-argument represents a set of
6880 overloaded member functions, the matching member function is selected
6881 from the set (_over.over_). */
6883 {
6888 /* [temp.arg.nontype] bullet 1 says the pointer to member
6889 expression must be a pointer-to-member constant. */
6894 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6895 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6898 }
6899 /* [temp.arg.nontype]/5, bullet 7
6901 For a non-type template-parameter of type pointer to data member,
6902 qualification conversions (_conv.qual_) are applied. */
6904 {
6905 /* [temp.arg.nontype] bullet 1 says the pointer to member
6906 expression must be a pointer-to-member constant. */
6914 }
6916 {
6918 {
6923 }
6925 }
6926 /* A template non-type parameter must be one of the above. */
6927 else
6930 /* Sanity check: did we actually convert the argument to the
6931 right type? */
6935 }
6937 /* Subroutine of coerce_template_template_parms, which returns 1 if
6938 PARM_PARM and ARG_PARM match using the rule for the template
6939 parameters of template template parameters. Both PARM and ARG are
6940 template parameters; the rest of the arguments are the same as for
6941 coerce_template_template_parms.
6942 */
6943 static int
6945 tree arg,
6946 tsubst_flags_t complain,
6947 tree in_decl,
6948 tree outer_args)
6949 {
6958 {
6960 /* We encounter instantiations of templates like
6961 template <template <template <class> class> class TT>
6962 class C; */
6963 {
6970 }
6971 /* Fall through. */
6976 /* Argument is a parameter pack but parameter is not. */
6981 /* The tsubst call is used to handle cases such as
6983 template <int> class C {};
6984 template <class T, template <T> class TT> class D {};
6985 D<int, C> d;
6987 i.e. the parameter list of TT depends on earlier parameters. */
6989 {
6994 }
6998 /* Argument is a parameter pack but parameter is not. */
7005 }
7008 }
7010 /* Coerce template argument list ARGLIST for use with template
7011 template-parameter TEMPL. */
7013 static tree
7015 tsubst_flags_t complain)
7016 {
7017 /* Consider an example where a template template parameter declared as
7019 template <class T, class U = std::allocator<T> > class TT
7021 The template parameter level of T and U are one level larger than
7022 of TT. To proper process the default argument of U, say when an
7023 instantiation `TT<int>' is seen, we need to build the full
7024 arguments containing {int} as the innermost level. Outer levels,
7025 available when not appearing as default template argument, can be
7026 obtained from the arguments of the enclosing template.
7028 Suppose that TT is later substituted with std::vector. The above
7029 instantiation is `TT<int, std::allocator<T> >' with TT at
7030 level 1, and T at level 2, while the template arguments at level 1
7031 becomes {std::vector} and the inner level 2 is {int}. */
7035 {
7037 /* We want arguments for the partial specialization, not arguments for
7038 the primary template. */
7040 else
7042 }
7044 {
7045 /* This is an argument of the current template, so we haven't set
7046 DECL_CONTEXT yet. */
7047 tree relevant_template_parms;
7049 /* Parameter levels that are greater than the level of the given
7050 template template parm are irrelevant. */
7057 }
7064 complain,
7067 }
7069 /* A cache of template template parameters with match-all default
7070 arguments. */
7072 static void
7074 {
7078 }
7079 static tree
7081 {
7086 }
7088 /* T is a bound template template-parameter. Copy its arguments into default
7089 arguments of the template template-parameter's template parameters. */
7091 static tree
7093 {
7116 {
7119 {
7122 }
7123 }
7127 }
7129 /* ARG is a bound potential template template-argument, and PARGS is a list
7130 of arguments for the corresponding template template-parameter. Adjust
7131 PARGS as appropriate for application to ARG's template, and if ARG is a
7132 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7133 arguments to the template template parameter. */
7135 static tree
7137 {
7141 {
7142 /* When comparing two template template-parameters in partial ordering,
7143 rewrite the one currently being used as an argument to have default
7144 arguments for all parameters. */
7150 }
7151 else
7152 {
7153 tree aparms
7158 }
7161 }
7163 /* Subroutine of unify for the case when PARM is a
7164 BOUND_TEMPLATE_TEMPLATE_PARM. */
7166 static int
7169 {
7173 /* The template template parm might be variadic and the argument
7174 not, so flatten both argument lists. */
7180 {
7181 /* In keeping with P0522R0, adjust P's template arguments
7182 to apply to A's template; then flatten it again. */
7185 }
7191 /* If the P0522 adjustment eliminated a pack expansion, deduce
7192 empty packs. */
7200 }
7202 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7203 template template parameters. Both PARM_PARMS and ARG_PARMS are
7204 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7205 or PARM_DECL.
7207 Consider the example:
7208 template <class T> class A;
7209 template<template <class U> class TT> class B;
7211 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7212 the parameters to A, and OUTER_ARGS contains A. */
7214 static int
7216 tree arg_parms,
7217 tsubst_flags_t complain,
7218 tree in_decl,
7219 tree outer_args)
7220 {
7232 {
7233 /* P0522R0: A template template-parameter P is at least as specialized as
7234 a template template-argument A if, given the following rewrite to two
7235 function templates, the function template corresponding to P is at
7236 least as specialized as the function template corresponding to A
7237 according to the partial ordering rules for function templates
7238 ([temp.func.order]). Given an invented class template X with the
7239 template parameter list of A (including default arguments):
7241 * Each of the two function templates has the same template parameters,
7242 respectively, as P or A.
7244 * Each function template has a single function parameter whose type is
7245 a specialization of X with template arguments corresponding to the
7246 template parameters from the respective function template where, for
7247 each template parameter PP in the template parameter list of the
7248 function template, a corresponding template argument AA is formed. If
7249 PP declares a parameter pack, then AA is the pack expansion
7250 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7252 If the rewrite produces an invalid type, then P is not at least as
7253 specialized as A. */
7255 /* So coerce P's args to apply to A's parms, and then deduce between A's
7256 args and the converted args. If that succeeds, A is at least as
7257 specialized as P, so they match.*/
7264 {
7270 }
7271 }
7273 /* Determine whether we have a parameter pack at the end of the
7274 template template parameter's template parameter list. */
7276 {
7283 {
7297 }
7298 }
7304 /* Check all of the template parameters except the parameter pack at
7305 the end (if any). */
7307 {
7316 outer_args))
7319 }
7322 {
7323 /* Check each of the template parameters in the template
7324 argument against the template parameter pack at the end of
7325 the template template parameter. */
7332 {
7339 outer_args))
7341 }
7342 }
7345 }
7347 /* Verifies that the deduced template arguments (in TARGS) for the
7348 template template parameters (in TPARMS) represent valid bindings,
7349 by comparing the template parameter list of each template argument
7350 to the template parameter list of its corresponding template
7351 template parameter, in accordance with DR150. This
7352 routine can only be called after all template arguments have been
7353 deduced. It will return TRUE if all of the template template
7354 parameter bindings are okay, FALSE otherwise. */
7355 bool
7357 {
7361 /* We're dealing with template parms in this process. */
7367 {
7372 {
7377 {
7378 /* Look inside the argument pack. */
7381 }
7384 {
7388 /* Extract the next argument from the argument
7389 pack. */
7393 /* Look at the pattern of the pack expansion. */
7396 /* Extract the template parameters from the template
7397 argument. */
7403 /* Verify that we can coerce the template template
7404 parameters from the template argument to the template
7405 parameter. This requires an exact match. */
7407 && !coerce_template_template_parms
7409 targ_parms,
7410 tf_none,
7411 tparm,
7412 targs))
7413 {
7416 }
7417 }
7418 }
7419 }
7421 out:
7425 }
7427 /* Since type attributes aren't mangled, we need to strip them from
7428 template type arguments. */
7430 static tree
7432 {
7442 }
7444 /* And from inside dependent non-type arguments like sizeof(Type). */
7446 static tree
7448 {
7458 }
7460 // A template declaration can be substituted for a constrained
7461 // template template parameter only when the argument is more
7462 // constrained than the parameter.
7463 static bool
7465 {
7468 /* For now, allow constrained template template arguments
7469 and unconstrained template template parameters. */
7475 // If the template parameter is constrained, we need to rewrite its
7476 // constraints in terms of the ARG's template parameters. This ensures
7477 // that all of the template parameter types will have the same depth.
7478 //
7479 // Note that this is only valid when coerce_template_template_parm is
7480 // true for the innermost template parameters of PARM and ARG. In other
7481 // words, because coercion is successful, this conversion will be valid.
7483 {
7490 }
7493 }
7495 // Convert a placeholder argument into a binding to the original
7496 // parameter. The original parameter is saved as the TREE_TYPE of
7497 // ARG.
7500 {
7503 }
7505 /* Convert the indicated template ARG as necessary to match the
7506 indicated template PARM. Returns the converted ARG, or
7507 error_mark_node if the conversion was unsuccessful. Error and
7508 warning messages are issued under control of COMPLAIN. This
7509 conversion is for the Ith parameter in the parameter list. ARGS is
7510 the full set of template arguments deduced so far. */
7512 static tree
7514 tree arg,
7515 tree args,
7516 tsubst_flags_t complain,
7518 tree in_decl)
7519 {
7520 tree orig_arg;
7521 tree val;
7527 /* Trivially convert placeholders. */
7536 {
7537 /* The template argument was the name of some
7538 member function. That's usually
7539 invalid, but static members are OK. In any
7540 case, grab the underlying fields/functions
7541 and issue an error later if required. */
7544 }
7552 /* When determining whether an argument pack expansion is a template,
7553 look at the pattern. */
7557 /* Deal with an injected-class-name used as a template template arg. */
7559 {
7562 {
7572 }
7573 }
7575 is_tmpl_type =
7591 {
7593 {
7597 }
7600 "to refer to a type member of a template parameter, "
7605 typename_type,
7606 complain);
7609 }
7611 {
7613 {
7615 {
7627 else
7630 }
7631 }
7633 }
7635 {
7637 {
7644 else
7647 }
7649 }
7652 /* We already did the appropriate conversion when packing args. */
7655 {
7657 {
7659 /* The number of argument required is not known yet.
7660 Just accept it for now. */
7662 else
7663 {
7665 tree argparm;
7667 /* Strip alias templates that are equivalent to another
7668 template. */
7674 args))
7675 {
7678 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7679 TEMPLATE_DECL. */
7681 {
7686 }
7687 }
7688 else
7689 {
7691 {
7698 }
7701 }
7703 // Check that the constraints are compatible before allowing the
7704 // substitution.
7707 {
7709 {
7715 }
7717 }
7718 }
7719 }
7720 else
7722 /* We only form one instance of each template specialization.
7723 Therefore, if we use a non-canonical variant (i.e., a
7724 typedef), any future messages referring to the type will use
7725 the typedef, which is confusing if those future uses do not
7726 themselves also use the typedef. */
7729 }
7730 else
7731 {
7735 {
7739 }
7740 else
7748 /* We used to call digest_init here. However, digest_init
7749 will report errors, which we don't want when complain
7750 is zero. More importantly, digest_init will try too
7751 hard to convert things: for example, `0' should not be
7752 converted to pointer type at this point according to
7753 the standard. Accepting this is not merely an
7754 extension, since deciding whether or not these
7755 conversions can occur is part of determining which
7756 function template to call, or whether a given explicit
7757 argument specification is valid. */
7759 else
7769 {
7770 /* Reject template arguments that are references to built-in
7771 functions with no library fallbacks. */
7780 }
7783 {
7784 /* Strip typedefs from the SCOPE_REF. */
7787 complain);
7790 }
7791 }
7794 }
7796 /* Coerces the remaining template arguments in INNER_ARGS (from
7797 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7798 Returns the coerced argument pack. PARM_IDX is the position of this
7799 parameter in the template parameter list. ARGS is the original
7800 template argument list. */
7801 static tree
7804 tree args,
7805 tree inner_args,
7807 tree new_args,
7809 tree in_decl,
7810 tsubst_flags_t complain)
7811 {
7814 tree packed_args;
7815 tree argument_pack;
7822 {
7823 /* When the template parameter is a non-type template parameter pack
7824 or template template parameter pack whose type or template
7825 parameters use parameter packs, we know exactly how many arguments
7826 we are looking for. Build a vector of the instantiated decls for
7827 these template parameters in PACKED_PARMS. */
7828 /* We can't use make_pack_expansion here because it would interpret a
7829 _DECL as a use rather than a declaration. */
7843 /* If we're doing a partial instantiation of a member template,
7844 verify that all of the types used for the non-type
7845 template parameter pack are, in fact, valid for non-type
7846 template parameters. */
7849 {
7852 {
7856 }
7857 /* We don't know how many args we have yet, just
7858 use the unconverted ones for now. */
7860 }
7863 }
7864 /* Check if we have a placeholder pack, which indicates we're
7865 in the context of a introduction list. In that case we want
7866 to match this pack to the single placeholder. */
7870 {
7873 }
7874 else
7877 /* Convert the remaining arguments, which will be a part of the
7878 parameter pack "parm". */
7881 {
7887 {
7888 /* Once we've packed as many args as we have types, stop. */
7892 /* We don't know how many args we have yet, just
7893 use the unconverted ones for now. */
7895 else
7897 }
7900 {
7903 }
7904 else
7907 in_decl);
7911 }
7915 {
7920 }
7925 else
7926 {
7929 }
7936 }
7938 /* Returns the number of pack expansions in the template argument vector
7939 ARGS. */
7941 static int
7943 {
7948 {
7952 }
7954 }
7956 /* Convert all template arguments to their appropriate types, and
7957 return a vector containing the innermost resulting template
7958 arguments. If any error occurs, return error_mark_node. Error and
7959 warning messages are issued under control of COMPLAIN.
7961 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7962 for arguments not specified in ARGS. Otherwise, if
7963 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7964 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7965 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7966 ARGS. */
7968 static tree
7970 tree args,
7971 tree in_decl,
7972 tsubst_flags_t complain,
7975 {
7977 tree orig_inner_args;
7978 tree inner_args;
7979 tree new_args;
7980 tree new_inner_args;
7984 /* When used as a boolean value, indicates whether this is a
7985 variadic template parameter list. Since it's an int, we can also
7986 subtract it from nparms to get the number of non-variadic
7987 parameters. */
7992 /* Likewise for parameters with default arguments. */
8000 /* Determine if there are any parameter packs or default arguments. */
8002 {
8010 }
8013 /* If there are no parameters that follow a parameter pack, we need to
8014 expand any argument packs so that we can deduce a parameter pack from
8015 some non-packed args followed by an argument pack, as in variadic85.C.
8016 If there are such parameters, we need to leave argument packs intact
8017 so the arguments are assigned properly. This can happen when dealing
8018 with a nested class inside a partial specialization of a class
8019 template, as in variadic92.C, or when deducing a template parameter pack
8020 from a sub-declarator, as in variadic114.C. */
8024 /* Count any pack expansion args. */
8030 && require_all_args
8031 && !variadic_args_p
8032 && (!use_default_args
8035 {
8037 {
8039 {
8043 }
8044 else
8051 }
8054 }
8055 /* We can't pass a pack expansion to a non-pack parameter of an alias
8056 template (DR 1430). */
8060 && variadic_args_p
8062 {
8064 {
8066 {
8072 {
8075 "pack expansion argument for non-pack parameter "
8077 else
8079 "pack expansion argument for non-pack parameter "
8083 }
8084 }
8086 found:;
8087 }
8089 }
8091 /* We need to evaluate the template arguments, even though this
8092 template-id may be nested within a "sizeof". */
8101 {
8102 tree arg;
8103 tree parm;
8105 /* Get the Ith template parameter. */
8109 {
8112 }
8114 /* Calculate the next argument. */
8117 else
8122 {
8123 /* Some arguments will be placed in the
8124 template parameter pack PARM. */
8131 {
8132 /* We don't know how many args we have yet, just use the
8133 unconverted (and still packed) ones for now. */
8137 }
8141 /* Store this argument. */
8143 {
8144 lost++;
8145 /* We are done with all of the arguments. */
8147 }
8148 else
8149 {
8152 }
8155 }
8157 {
8159 {
8160 /* "If every valid specialization of a variadic template
8161 requires an empty template parameter pack, the template is
8162 ill-formed, no diagnostic required." So check that the
8163 pattern works with this parameter. */
8168 in_decl);
8170 {
8175 }
8177 /* Recover from missing typename. */
8181 /* We don't know how many args we have yet, just
8182 use the unconverted ones for now. */
8186 }
8187 }
8189 {
8190 /* There must be a default arg in this case. */
8193 /* The position of the first default template argument,
8194 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8195 Record that. */
8199 }
8200 else
8204 {
8207 }
8209 /* This only occurs if there was an error in the template
8210 parameter list itself (which we would already have
8211 reported) that we are trying to recover from, e.g., a class
8212 template with a parameter list such as
8213 template<typename..., typename>. */
8215 else
8221 lost++;
8223 }
8228 {
8230 {
8235 }
8237 }
8247 }
8249 /* Convert all template arguments to their appropriate types, and
8250 return a vector containing the innermost resulting template
8251 arguments. If any error occurs, return error_mark_node. Error and
8252 warning messages are not issued.
8254 Note that no function argument deduction is performed, and default
8255 arguments are used to fill in unspecified arguments. */
8256 tree
8258 {
8260 }
8262 /* Convert all template arguments to their appropriate type, and
8263 instantiate default arguments as needed. This returns a vector
8264 containing the innermost resulting template arguments, or
8265 error_mark_node if unsuccessful. */
8266 tree
8268 tsubst_flags_t complain)
8269 {
8271 }
8273 /* Like coerce_template_parms. If PARMS represents all template
8274 parameters levels, this function returns a vector of vectors
8275 representing all the resulting argument levels. Note that in this
8276 case, only the innermost arguments are coerced because the
8277 outermost ones are supposed to have been coerced already.
8279 Otherwise, if PARMS represents only (the innermost) vector of
8280 parameters, this function returns a vector containing just the
8281 innermost resulting arguments. */
8283 static tree
8285 tree args,
8286 tree in_decl,
8287 tsubst_flags_t complain,
8290 {
8293 tree coerced_args;
8296 {
8298 tree level;
8304 {
8305 tree l;
8309 require_all_args,
8310 use_default_args);
8311 else
8318 }
8319 }
8320 else
8323 require_all_args,
8324 use_default_args);
8326 }
8328 /* Returns 1 if template args OT and NT are equivalent. */
8330 int
8332 {
8341 /* For member templates */
8350 {
8367 }
8371 {
8374 /* Don't treat an alias template specialization with dependent
8375 arguments as equivalent to its underlying type when used as a
8376 template argument; we need them to be distinct so that we
8377 substitute into the specialization arguments at instantiation
8378 time. And aliases can't be equivalent without being ==, so
8379 we don't need to look any deeper.
8381 During partial ordering, however, we need to treat them normally so
8382 that we can order uses of the same alias with different
8383 cv-qualification (79960). */
8387 else
8389 }
8392 else
8393 {
8394 /* Try to treat a template non-type argument that has been converted
8395 to the parameter type as equivalent to one that hasn't yet. */
8408 }
8409 }
8411 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8412 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8413 NEWARG_PTR with the offending arguments if they are non-NULL. */
8415 int
8419 {
8432 {
8437 {
8443 }
8444 }
8446 }
8450 {
8452 }
8454 static void
8456 {
8466 /* We are called both from instantiate_decl, where we've already had a
8467 tinst_level pushed, and instantiate_template, where we haven't.
8468 Compensate. */
8479 else
8488 }
8491 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8492 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8493 documentation for TEMPLATE_ID_EXPR. */
8495 tree
8497 {
8498 tree type;
8506 {
8509 }
8512 {
8514 unknown_type_node,
8516 arglist);
8518 }
8525 }
8527 /* Within the scope of a template class S<T>, the name S gets bound
8528 (in build_self_reference) to a TYPE_DECL for the class, not a
8529 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8530 or one of its enclosing classes, and that type is a template,
8531 return the associated TEMPLATE_DECL. Otherwise, the original
8532 DECL is returned.
8534 Also handle the case when DECL is a TREE_LIST of ambiguous
8535 injected-class-names from different bases. */
8537 tree
8539 {
8543 /* DR 176: A lookup that finds an injected-class-name (10.2
8544 [class.member.lookup]) can result in an ambiguity in certain cases
8545 (for example, if it is found in more than one base class). If all of
8546 the injected-class-names that are found refer to specializations of
8547 the same class template, and if the name is followed by a
8548 template-argument-list, the reference refers to the class template
8549 itself and not a specialization thereof, and is not ambiguous. */
8551 {
8554 {
8560 }
8563 else
8565 }
8571 }
8573 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8574 parameters, find the desired type.
8576 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8578 IN_DECL, if non-NULL, is the template declaration we are trying to
8579 instantiate.
8581 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8582 the class we are looking up.
8584 Issue error and warning messages under control of COMPLAIN.
8586 If the template class is really a local class in a template
8587 function, then the FUNCTION_CONTEXT is the function in which it is
8588 being instantiated.
8590 ??? Note that this function is currently called *twice* for each
8591 template-id: the first time from the parser, while creating the
8592 incomplete type (finish_template_type), and the second type during the
8593 real instantiation (instantiate_template_class). This is surely something
8594 that we want to avoid. It also causes some problems with argument
8595 coercion (see convert_nontype_argument for more information on this). */
8597 static tree
8600 {
8602 tree t;
8605 spec_entry elt;
8606 hashval_t hash;
8609 {
8613 else
8614 {
8621 }
8624 }
8626 {
8629 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8630 an implicit typename for the second A. Deal with it. */
8635 {
8638 }
8639 }
8642 {
8645 }
8647 {
8651 }
8653 {
8656 }
8658 /* Issue an error message if we didn't find a template. */
8660 {
8664 }
8667 /* Make sure it's a user visible template, if it was named by
8668 the user. */
8671 {
8673 {
8677 }
8679 }
8683 /* An alias that just changes the name of a template is equivalent to the
8684 other template, so if any of the arguments are pack expansions, strip
8685 the alias to avoid problems with a pack expansion passed to a non-pack
8686 alias template parameter (DR 1430). */
8691 {
8692 tree parm;
8701 }
8702 else
8703 {
8705 tree gen_tmpl;
8706 tree type_decl;
8714 /* An error occurred while building the template TEMPL, and a
8715 diagnostic has most certainly been emitted for that
8716 already. Let's propagate that error. */
8725 {
8726 /* We've been given an incomplete set of template arguments.
8727 For example, given:
8729 template <class T> struct S1 {
8730 template <class U> struct S2 {};
8731 template <class U> struct S2<U*> {};
8732 };
8734 we will be called with an ARGLIST of `U*', but the
8735 TEMPLATE will be `template <class T> template
8736 <class U> struct S1<T>::S2'. We must fill in the missing
8737 arguments. */
8741 }
8743 /* Now we should have enough arguments. */
8746 /* From here on, we're only interested in the most general
8747 template. */
8749 /* Calculate the BOUND_ARGS. These will be the args that are
8750 actually tsubst'd into the definition to create the
8751 instantiation. */
8753 complain,
8758 /* We were unable to bind the arguments. */
8761 /* In the scope of a template class, explicit references to the
8762 template class refer to the type of the template, not any
8763 instantiation of it. For example, in:
8765 template <class T> class C { void f(C<T>); }
8767 the `C<T>' is just the same as `C'. Outside of the
8768 class, however, such a reference is an instantiation. */
8772 {
8777 }
8779 /* If we already have this specialization, return it. */
8789 /* If the the template's constraints are not satisfied,
8790 then we cannot form a valid type.
8792 Note that the check is deferred until after the hash
8793 lookup. This prevents redundant checks on previously
8794 instantiated specializations. */
8796 {
8798 {
8801 }
8803 }
8807 /* If the deduced arguments are invalid, then the binding
8808 failed. */
8812 complain))
8819 {
8824 }
8834 /* Create the type. */
8836 {
8837 /* The user referred to a specialization of an alias
8838 template represented by GEN_TMPL.
8840 [temp.alias]/2 says:
8842 When a template-id refers to the specialization of an
8843 alias template, it is equivalent to the associated
8844 type obtained by substitution of its
8845 template-arguments for the template-parameters in the
8846 type-id of the alias template. */
8849 /* Note that the call above (by indirectly calling
8850 register_specialization in tsubst_decl) registers the
8851 TYPE_DECL representing the specialization of the alias
8852 template. So next time someone substitutes ARGLIST for
8853 the template parms into the alias template (GEN_TMPL),
8854 she'll get that TYPE_DECL back. */
8858 }
8860 {
8862 {
8873 }
8874 else
8875 {
8876 /* We don't want to call start_enum for this type, since
8877 the values for the enumeration constants may involve
8878 template parameters. And, no one should be interested
8879 in the enumeration constants for such a type. */
8882 }
8886 }
8888 {
8894 /* A local class. Make sure the decl gets registered properly. */
8899 /* This instantiation is another name for the primary
8900 template type. Set the TYPE_CANONICAL field
8901 appropriately. */
8904 /* Some of the template arguments require structural
8905 equality testing, so this template class requires
8906 structural equality testing. */
8908 }
8909 else
8912 /* If we called start_enum or pushtag above, this information
8913 will already be set up. */
8915 {
8922 }
8923 else
8927 {
8933 {
8936 }
8937 }
8941 {
8945 {
8946 tree attributes
8954 }
8955 }
8957 /* Let's consider the explicit specialization of a member
8958 of a class template specialization that is implicitly instantiated,
8959 e.g.:
8960 template<class T>
8961 struct S
8962 {
8963 template<class U> struct M {}; //#0
8964 };
8966 template<>
8967 template<>
8968 struct S<int>::M<char> //#1
8969 {
8970 int i;
8971 };
8972 [temp.expl.spec]/4 says this is valid.
8974 In this case, when we write:
8975 S<int>::M<char> m;
8977 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8978 the one of #0.
8980 When we encounter #1, we want to store the partial instantiation
8981 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8983 For all cases other than this "explicit specialization of member of a
8984 class template", we just want to store the most general template into
8985 the CLASSTYPE_TI_TEMPLATE of M.
8987 This case of "explicit specialization of member of a class template"
8988 only happens when:
8989 1/ the enclosing class is an instantiation of, and therefore not
8990 the same as, the context of the most general template, and
8991 2/ we aren't looking at the partial instantiation itself, i.e.
8992 the innermost arguments are not the same as the innermost parms of
8993 the most general template.
8995 So it's only when 1/ and 2/ happens that we want to use the partial
8996 instantiation of the member template in lieu of its most general
8997 template. */
9001 /* the enclosing class must be an instantiation... */
9004 {
9008 tree partial_inst_args =
9015 use_partial_inst_tmpl =
9016 /*...and we must not be looking at the partial instantiation
9017 itself. */
9019 partial_inst_args);
9020 }
9023 /* This case is easy; there are no member templates involved. */
9025 else
9026 {
9027 /* This is a full instantiation of a member template. Find
9028 the partial instantiation of which this is an instance. */
9030 /* Temporarily reduce by one the number of levels in the ARGLIST
9031 so as to avoid comparing the last set of arguments. */
9035 /* FOUND is either a proper class type, or an alias
9036 template specialization. In the later case, it's a
9037 TYPE_DECL, resulting from the substituting of arguments
9038 for parameters in the TYPE_DECL of the alias template
9039 done earlier. So be careful while getting the template
9040 of FOUND. */
9042 ? found
9046 }
9048 // Build template info for the new specialization.
9057 /* Note this use of the partial instantiation so we can check it
9058 later in maybe_process_partial_specialization. */
9065 /* Now that the type has been registered on the instantiations
9066 list, we set up the enumerators. Because the enumeration
9067 constants may involve the enumeration type itself, we make
9068 sure to register the type first, and then create the
9069 constants. That way, doing tsubst_expr for the enumeration
9070 constants won't result in recursive calls here; we'll find
9071 the instantiation and exit above. */
9075 /* If the type makes use of template parameters, the
9076 code that generates debugging information will crash. */
9079 /* Possibly limit visibility based on template args. */
9086 }
9087 }
9089 /* Wrapper for lookup_template_class_1. */
9091 tree
9094 {
9095 tree ret;
9101 }
9103 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9105 tree
9107 {
9108 /* The type of the expression is NULL_TREE since the template-id could refer
9109 to an explicit or partial specialization. */
9112 /* Except that concepts are always bool. */
9115 }
9117 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9119 tree
9121 {
9125 /* We never want to return a VAR_DECL for a variable concept, since they
9126 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9141 {
9143 {
9146 }
9148 }
9150 /* If a template-id refers to a specialization of a variable
9151 concept, then the expression is true if and only if the
9152 concept's constraints are satisfied by the given template
9153 arguments.
9155 NOTE: This is an extension of Concepts Lite TS that
9156 allows constraints to be used in expressions. */
9158 {
9161 }
9164 }
9166 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9167 TARGS template args, and instantiate it if it's not dependent. */
9169 tree
9171 tsubst_flags_t complain)
9172 {
9175 {
9178 }
9181 }
9183 \f
9184 struct pair_fn_data
9185 {
9186 tree_fn_t fn;
9187 tree_fn_t any_fn;
9189 /* True when we should also visit template parameters that occur in
9190 non-deduced contexts. */
9193 };
9195 /* Called from for_each_template_parm via walk_tree. */
9197 static tree
9199 {
9206 #define WALK_SUBTREE(NODE) \
9207 do \
9208 { \
9209 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9210 pfd->include_nondeduced_p, \
9211 pfd->any_fn); \
9212 if (result) goto out; \
9213 } \
9214 while (0)
9224 {
9228 /* Fall through. */
9234 else
9244 /* Since we're not going to walk subtrees, we have to do this
9245 explicitly here. */
9247 /* Fall through. */
9250 /* Check the return type. */
9253 /* Check the parameter types. Since default arguments are not
9254 instantiated until they are needed, the TYPE_ARG_TYPES may
9255 contain expressions that involve template parameters. But,
9256 no-one should be looking at them yet. And, once they're
9257 instantiated, they don't contain template parameters, so
9258 there's no point in looking at them then, either. */
9259 {
9260 tree parm;
9265 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9266 want walk_tree walking into them itself. */
9268 }
9271 {
9275 }
9292 /* Fall through. */
9304 /* Record template parameters such as `T' inside `TT<T>'. */
9306 /* Fall through. */
9318 /* A template template parameter is encountered. */
9322 /* Already substituted template template parameter */
9327 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9328 partial instantiation. */
9340 /* If there's no type, then this thing must be some expression
9341 involving template parameters. */
9363 }
9365 #undef WALK_SUBTREE
9367 /* We didn't find any template parameters we liked. */
9368 out:
9370 }
9372 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9373 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9374 call FN with the parameter and the DATA.
9375 If FN returns nonzero, the iteration is terminated, and
9376 for_each_template_parm returns 1. Otherwise, the iteration
9377 continues. If FN never returns a nonzero value, the value
9378 returned by for_each_template_parm is 0. If FN is NULL, it is
9379 considered to be the function which always returns 1.
9381 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9382 parameters that occur in non-deduced contexts. When false, only
9383 visits those template parameters that can be deduced. */
9385 static tree
9389 tree_fn_t any_fn)
9390 {
9392 tree result;
9394 /* Set up. */
9400 /* Walk the tree. (Conceptually, we would like to walk without
9401 duplicates, but for_each_template_parm_r recursively calls
9402 for_each_template_parm, so we would need to reorganize a fair
9403 bit to use walk_tree_without_duplicates, so we keep our own
9404 visited list.) */
9407 else
9410 for_each_template_parm_r,
9414 /* Clean up. */
9416 {
9419 }
9422 }
9424 /* Returns true if T depends on any template parameter. */
9426 int
9428 {
9458 else
9459 {
9462 }
9467 }
9469 /* Returns true iff current_function_decl is an incompletely instantiated
9470 template. Useful instead of processing_template_decl because the latter
9471 is set to 0 during instantiate_non_dependent_expr. */
9473 bool
9475 {
9484 }
9486 /* Returns true if T depends on any template parameter with level LEVEL. */
9488 bool
9490 {
9493 }
9495 /* Returns true if the signature of DECL depends on any template parameter from
9496 its enclosing class. */
9498 bool
9500 {
9510 template_parm_outer_level,
9520 }
9522 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9523 ill-formed translation unit, i.e. a variable or function that isn't
9524 usable in a constant expression. */
9528 {
9532 }
9534 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9535 neglectable and instantiated from within an erroneous instantiation. */
9537 static bool
9539 {
9550 }
9558 /* We're starting to instantiate D; record the template instantiation context
9559 for diagnostics and to restore it later. */
9561 bool
9563 {
9565 }
9567 /* We're starting to instantiate D; record the template instantiation context
9568 at LOC for diagnostics and to restore it later. */
9570 bool
9572 {
9576 {
9577 /* Tell error.c not to try to instantiate any templates. */
9580 "template instantiation depth exceeds maximum of %d"
9582 max_tinst_depth);
9584 }
9586 /* If the current instantiation caused problems, don't let it instantiate
9587 anything else. Do allow deduction substitution and decls usable in
9588 constant expressions. */
9592 /* When not -quiet, dump template instantiations other than functions, since
9593 announce_function will take care of those. */
9612 }
9614 /* We're done instantiating this template; return to the instantiation
9615 context. */
9617 void
9619 {
9620 /* Restore the filename and line number stashed away when we started
9621 this instantiation. */
9625 }
9627 /* We're instantiating a deferred template; restore the template
9628 instantiation context in which the instantiation was requested, which
9629 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9631 static tree
9633 {
9645 }
9647 /* Returns the TINST_LEVEL which gives the original instantiation
9648 context. */
9652 {
9658 }
9660 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9661 vector of template arguments, as for tsubst.
9663 Returns an appropriate tsubst'd friend declaration. */
9665 static tree
9667 {
9668 tree new_friend;
9673 /* This was a friend declared with an explicit template
9674 argument list, e.g.:
9676 friend void f<>(T);
9678 to indicate that f was a template instantiation, not a new
9679 function declaration. Now, we have to figure out what
9680 instantiation of what template. */
9681 {
9683 tree new_args;
9684 tree tmpl;
9687 /* Friend functions are looked up in the containing namespace scope.
9688 We must enter that scope, to avoid finding member functions of the
9689 current class with same name. */
9704 tsk_none);
9706 }
9710 /* The NEW_FRIEND will look like an instantiation, to the
9711 compiler, but is not an instantiation from the point of view of
9712 the language. For example, we might have had:
9714 template <class T> struct S {
9715 template <class U> friend void f(T, U);
9716 };
9718 Then, in S<int>, template <class U> void f(int, U) is not an
9719 instantiation of anything. */
9725 {
9729 }
9731 /* The mangled name for the NEW_FRIEND is incorrect. The function
9732 is not a template instantiation and should not be mangled like
9733 one. Therefore, we forget the mangling here; we'll recompute it
9734 later if we need it. */
9736 {
9739 }
9742 {
9743 tree old_decl;
9744 tree new_friend_template_info;
9745 tree new_friend_result_template_info;
9746 tree ns;
9749 /* We must save some information from NEW_FRIEND before calling
9750 duplicate decls since that function will free NEW_FRIEND if
9751 possible. */
9753 new_friend_is_defn =
9758 {
9759 /* This declaration is a `primary' template. */
9762 new_friend_result_template_info
9764 }
9765 else
9768 /* Inside pushdecl_namespace_level, we will push into the
9769 current namespace. However, the friend function should go
9770 into the namespace of the template. */
9780 {
9781 /* This new friend declaration matched an existing
9782 declaration. For example, given:
9784 template <class T> void f(T);
9785 template <class U> class C {
9786 template <class T> friend void f(T) {}
9787 };
9789 the friend declaration actually provides the definition
9790 of `f', once C has been instantiated for some type. So,
9791 old_decl will be the out-of-class template declaration,
9792 while new_friend is the in-class definition.
9794 But, if `f' was called before this point, the
9795 instantiation of `f' will have DECL_TI_ARGS corresponding
9796 to `T' but not to `U', references to which might appear
9797 in the definition of `f'. Previously, the most general
9798 template for an instantiation of `f' was the out-of-class
9799 version; now it is the in-class version. Therefore, we
9800 run through all specialization of `f', adding to their
9801 DECL_TI_ARGS appropriately. In particular, they need a
9802 new set of outer arguments, corresponding to the
9803 arguments for this class instantiation.
9805 The same situation can arise with something like this:
9807 friend void f(int);
9808 template <class T> class C {
9809 friend void f(T) {}
9810 };
9812 when `C<int>' is instantiated. Now, `f(int)' is defined
9813 in the class. */
9816 /* On the other hand, if the in-class declaration does
9817 *not* provide a definition, then we don't want to alter
9818 existing definitions. We can just leave everything
9819 alone. */
9820 ;
9821 else
9822 {
9826 /* Overwrite whatever template info was there before, if
9827 any, with the new template information pertaining to
9828 the declaration. */
9832 {
9833 /* We should have called reregister_specialization in
9834 duplicate_decls. */
9839 /* Instantiate it if the global has already been used. */
9843 }
9844 else
9845 {
9846 tree t;
9848 /* Indicate that the old function template is a partial
9849 instantiation. */
9857 /* Reassign any specializations already in the hash table
9858 to the new more general template, and add the
9859 additional template args. */
9863 {
9865 spec_entry elt;
9877 register_specialization
9880 }
9882 }
9883 }
9885 /* The information from NEW_FRIEND has been merged into OLD_DECL
9886 by duplicate_decls. */
9888 }
9889 }
9890 else
9891 {
9895 /* In the code
9896 template <class T> class C {
9897 template <class U> friend void C1<U>::f (); // case 1
9898 friend void C2<T>::f (); // case 2
9899 };
9900 we only need to make sure CONTEXT is a complete type for
9901 case 2. To distinguish between the two cases, we note that
9902 CONTEXT of case 1 remains dependent type after tsubst while
9903 this isn't true for case 2. */
9913 {
9915 /* do_friend adds the TEMPLATE_DECL for any member friend
9916 template even if it isn't a member template, i.e.
9917 template <class T> friend A<T>::f();
9918 Look through it in that case. */
9922 /* Check to see that the declaration is really present, and,
9923 possibly obtain an improved declaration. */
9928 }
9929 }
9932 }
9934 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9935 template arguments, as for tsubst.
9937 Returns an appropriate tsubst'd friend type or error_mark_node on
9938 failure. */
9940 static tree
9942 {
9943 tree friend_type;
9944 tree tmpl;
9945 tree context;
9948 {
9951 }
9956 {
9959 else
9961 }
9963 /* Look for a class template declaration. We look for hidden names
9964 because two friend declarations of the same template are the
9965 same. For example, in:
9967 struct A {
9968 template <typename> friend class F;
9969 };
9970 template <typename> struct B {
9971 template <typename> friend class F;
9972 };
9974 both F templates are the same. */
9978 /* But, if we don't find one, it might be because we're in a
9979 situation like this:
9981 template <class T>
9982 struct S {
9983 template <class U>
9984 friend struct S;
9985 };
9987 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9988 for `S<int>', not the TEMPLATE_DECL. */
9990 {
9993 }
9996 {
9997 /* The friend template has already been declared. Just
9998 check to see that the declarations match, and install any new
9999 default parameters. We must tsubst the default parameters,
10000 of course. We only need the innermost template parameters
10001 because that is all that redeclare_class_template will look
10002 at. */
10005 {
10006 tree parms;
10007 location_t saved_input_location;
10017 }
10020 }
10021 else
10022 {
10023 /* The friend template has not already been declared. In this
10024 case, the instantiation of the template class will cause the
10025 injection of this template into the global scope. */
10030 /* The new TMPL is not an instantiation of anything, so we
10031 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10032 the new type because that is supposed to be the corresponding
10033 template decl, i.e., TMPL. */
10040 /* Inject this template into the global scope. */
10042 }
10045 {
10048 else
10050 }
10053 }
10055 /* Returns zero if TYPE cannot be completed later due to circularity.
10056 Otherwise returns one. */
10058 static int
10060 {
10070 else
10072 }
10077 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10078 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10080 static tree
10083 {
10092 {
10099 clauses
10103 else
10105 }
10106 /* If the first attribute argument is an identifier, don't
10107 pass it through tsubst. Attributes like mode, format,
10108 cleanup and several target specific attributes expect it
10109 unmodified. */
10111 {
10112 tree chain
10117 }
10119 {
10120 /* An attribute pack expansion. */
10129 {
10133 }
10135 }
10136 else
10143 }
10145 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10146 unchanged or a new TREE_LIST chain. */
10148 static tree
10151 {
10156 {
10160 }
10164 {
10167 {
10170 {
10172 do
10177 }
10178 }
10180 }
10183 }
10185 /* Apply any attributes which had to be deferred until instantiation
10186 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10187 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10189 static void
10192 {
10194 tree t;
10201 {
10205 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10206 to our attributes parameter. */
10208 }
10209 else
10210 {
10212 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10213 lookup_template_class_1, and should be preserved. */
10217 }
10221 {
10225 }
10229 {
10234 {
10237 {
10241 do
10244 }
10245 else
10247 }
10250 }
10251 }
10253 /* Perform (or defer) access check for typedefs that were referenced
10254 from within the template TMPL code.
10255 This is a subroutine of instantiate_decl and instantiate_class_template.
10256 TMPL is the template to consider and TARGS is the list of arguments of
10257 that template. */
10259 static void
10261 {
10262 location_t saved_location;
10273 {
10285 /* Make access check error messages point to the location
10286 of the use of the typedef. */
10290 tf_warning_or_error);
10291 }
10293 }
10295 static tree
10297 {
10299 tree typedecl;
10300 tree pbinfo;
10301 tree base_list;
10303 tree fn_context;
10312 /* Figure out which template is being instantiated. */
10316 /* Determine what specialization of the original template to
10317 instantiate. */
10320 {
10323 }
10325 {
10326 /* This TYPE is actually an instantiation of a partial
10327 specialization. We replace the innermost set of ARGS with
10328 the arguments appropriate for substitution. For example,
10329 given:
10331 template <class T> struct S {};
10332 template <class T> struct S<T*> {};
10334 and supposing that we are instantiating S<int*>, ARGS will
10335 presently be {int*} -- but we need {int}. */
10338 }
10339 else
10340 {
10343 }
10345 /* If the template we're instantiating is incomplete, then clearly
10346 there's nothing we can do. */
10350 /* If we've recursively instantiated too many templates, stop. */
10354 /* Now we're really doing the instantiation. Mark the type as in
10355 the process of being defined. */
10358 /* We may be in the middle of deferred access check. Disable
10359 it now. */
10366 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10371 else
10372 {
10375 }
10376 /* Use #pragma pack from the template context. */
10382 /* Set the input location to the most specialized template definition.
10383 This is needed if tsubsting causes an error. */
10395 {
10398 /* Adjust visibility for template arguments. */
10400 }
10406 /* We should never instantiate a nested class before its enclosing
10407 class; we need to look up the nested class by name before we can
10408 instantiate it, and that lookup should instantiate the enclosing
10409 class. */
10415 {
10416 tree pbase_binfo;
10417 tree pushed_scope;
10420 /* We must enter the scope containing the type, as that is where
10421 the accessibility of types named in dependent bases are
10422 looked up from. */
10425 /* Substitute into each of the bases to determine the actual
10426 basetypes. */
10428 {
10429 tree base;
10435 {
10436 expanded_bases =
10443 }
10446 {
10448 /* Extract the already-expanded base class. */
10450 else
10451 /* Substitute to figure out the base class. */
10453 NULL_TREE);
10461 }
10462 }
10464 /* The list is now in reverse order; correct that. */
10469 }
10470 /* Now call xref_basetypes to set up all the base-class
10471 information. */
10479 /* Now that our base classes are set up, enter the scope of the
10480 class, so that name lookups into base classes, etc. will work
10481 correctly. This is precisely analogous to what we do in
10482 begin_class_definition when defining an ordinary non-template
10483 class, except we also need to push the enclosing classes. */
10486 /* Now members are processed in the order of declaration. */
10489 {
10493 {
10495 {
10496 /* Build new CLASSTYPE_NESTED_UTDS. */
10498 tree newtag;
10504 /* If the member is a class template, then -- even after
10505 substitution -- there may be dependent types in the
10506 template argument list for the class. We increment
10507 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10508 that function will assume that no types are dependent
10509 when outside of a template. */
10519 {
10523 /* Unfortunately, lookup_template_class sets
10524 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10525 instantiation (i.e., for the type of a member
10526 template class nested within a template class.)
10527 This behavior is required for
10528 maybe_process_partial_specialization to work
10529 correctly, but is not accurate in this case;
10530 the TAG is not an instantiation of anything.
10531 (The corresponding TEMPLATE_DECL is an
10532 instantiation, but the TYPE is not.) */
10535 /* Now, we call pushtag to put this NEWTAG into the scope of
10536 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10537 pushtag calling push_template_decl. We don't have to do
10538 this for enums because it will already have been done in
10539 tsubst_enum. */
10543 }
10544 }
10546 {
10547 /* Build new TYPE_METHODS. */
10548 tree r;
10557 /* Instantiate members marked with attribute used. */
10563 }
10566 /* A closure type for a lambda in a default argument for a
10567 member template. Ignore it; it will be instantiated with
10569 else
10570 {
10571 /* Build new TYPE_FIELDS. */
10573 {
10574 tree condition;
10577 condition =
10587 }
10589 {
10590 tree r;
10594 /* The file and line for this declaration, to
10595 assist in error message reporting. Since we
10596 called push_tinst_level above, we don't need to
10597 restore these. */
10607 {
10608 /* A capture pack became multiple fields. */
10611 }
10614 {
10618 {
10619 /* In [temp.inst]:
10621 [t]he initialization (and any associated
10622 side-effects) of a static data member does
10623 not occur unless the static data member is
10624 itself used in a way that requires the
10625 definition of the static data member to
10626 exist.
10628 Therefore, we do not substitute into the
10629 initialized for the static data member here. */
10630 finish_static_data_member_decl
10636 /* Instantiate members marked with attribute used. */
10639 }
10641 {
10642 /* Determine whether R has a valid type and can be
10643 completed later. If R is invalid, then its type
10644 is replaced by error_mark_node. */
10650 {
10651 /* If R's type couldn't be completed and
10652 it isn't a flexible array member (whose
10653 type is incomplete by definition) give
10654 an error. */
10657 }
10658 }
10660 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10661 such a thing will already have been added to the field
10662 list by tsubst_enum in finish_member_declaration in the
10663 CLASSTYPE_NESTED_UTDS case above. */
10667 {
10670 }
10671 }
10672 }
10673 }
10674 }
10675 else
10676 {
10679 {
10680 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10686 {
10687 /* template <class T> friend class C; */
10690 }
10692 {
10693 /* template <class T> friend class C::D; */
10699 }
10702 {
10703 /* This could be either
10705 friend class T::C;
10707 when dependent_type_p is false or
10709 template <class U> friend class T::C;
10711 otherwise. */
10712 /* Bump processing_template_decl in case this is something like
10713 template <class T> friend struct A<T>::B. */
10720 }
10723 {
10724 /* friend class C;
10726 where C hasn't been declared yet. Let's lookup name
10727 from namespace scope directly, bypassing any name that
10728 come from dependent base class. */
10731 /* The call to xref_tag_from_type does injection for friend
10732 classes. */
10734 friend_type =
10738 }
10740 /* friend class C<T>; */
10743 /* Otherwise it's
10745 friend class C;
10747 where C is already declared or
10749 friend class C<int>;
10751 We don't have to do anything in these cases. */
10754 /* Trick make_friend_class into realizing that the friend
10755 we're adding is a template, not an ordinary class. It's
10756 important that we use make_friend_class since it will
10757 perform some error-checking and output cross-reference
10758 information. */
10766 }
10767 else
10768 {
10769 /* Build new DECL_FRIENDLIST. */
10770 tree r;
10772 /* The file and line for this declaration, to
10773 assist in error message reporting. Since we
10774 called push_tinst_level above, we don't need to
10775 restore these. */
10779 {
10782 }
10787 {
10790 }
10791 }
10792 }
10793 }
10796 {
10797 /* Restore these before substituting into the lambda capture
10798 initializers. */
10801 }
10804 {
10807 {
10813 {
10814 /* Set function_depth to avoid garbage collection. */
10818 }
10820 /* We need to instantiate the capture list from the template
10821 after we've instantiated the closure members, but before we
10822 consider adding the conversion op. Also keep any captures
10823 that may have been added during instantiation of the op(). */
10825 tree tmpl_cap
10834 }
10835 else
10837 }
10839 /* Set the file and line number information to whatever is given for
10840 the class itself. This puts error messages involving generated
10841 implicit functions at a predictable point, and the same point
10842 that would be used for non-template classes. */
10849 /* We don't instantiate default arguments for member functions. 14.7.1:
10851 The implicit instantiation of a class template specialization causes
10852 the implicit instantiation of the declarations, but not of the
10853 definitions or default arguments, of the class member functions,
10854 member classes, static data members and member templates.... */
10856 /* Some typedefs referenced from within the template code need to be access
10857 checked at template instantiation time, i.e now. These types were
10858 added to the template at parsing time. Let's get those and perform
10859 the access checks then. */
10869 /* The vtable for a template class can be emitted in any translation
10870 unit in which the class is instantiated. When there is no key
10871 method, however, finish_struct_1 will already have added TYPE to
10872 the keyed_classes list. */
10877 }
10879 /* Wrapper for instantiate_class_template_1. */
10881 tree
10883 {
10884 tree ret;
10889 }
10891 static tree
10893 {
10894 tree r;
10900 else
10901 {
10908 }
10910 }
10912 /* Given a function parameter pack TMPL_PARM and some function parameters
10913 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10914 and set *SPEC_P to point at the next point in the list. */
10916 tree
10918 {
10919 /* Collect all of the extra "packed" parameters into an
10920 argument pack. */
10921 tree parmvec;
10931 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10937 /* Build the argument packs. */
10942 }
10944 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10945 NONTYPE_ARGUMENT_PACK. */
10947 static tree
10949 {
10951 }
10953 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10954 pack expansion with no extra args, 2 if it has extra args, or 0
10955 if it is not a pack expansion. */
10957 static int
10959 {
10965 /* A decl pack is itself an expansion. */
10972 }
10975 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10977 static tree
10979 {
10986 }
10988 /* This is a subroutine of tsubst_pack_expansion.
10990 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10991 mechanism to store the (non complete list of) arguments of the
10992 substitution and return a non substituted pack expansion, in order
10993 to wait for when we have enough arguments to really perform the
10994 substitution. */
10996 static bool
11000 {
11001 /* If one pack has an expansion and another pack has a normal
11002 argument or if one pack has an empty argument and an another
11003 one hasn't then tsubst_pack_expansion cannot perform the
11004 substitution and need to fall back on the
11005 PACK_EXPANSION_EXTRA mechanism. */
11013 {
11016 parm_pack;
11018 {
11023 /* We can't substitute a pack expansion with extra args into
11024 our pattern. */
11028 else
11030 }
11034 }
11036 }
11038 /* [temp.variadic]/6 says that:
11040 The instantiation of a pack expansion [...]
11041 produces a list E1,E2, ..., En, where N is the number of elements
11042 in the pack expansion parameters.
11044 This subroutine of tsubst_pack_expansion produces one of these Ei.
11046 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11047 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11048 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11049 INDEX is the index 'i' of the element Ei to produce. ARGS,
11050 COMPLAIN, and IN_DECL are the same parameters as for the
11051 tsubst_pack_expansion function.
11053 The function returns the resulting Ei upon successful completion,
11054 or error_mark_node.
11056 Note that this function possibly modifies the ARGS parameter, so
11057 it's the responsibility of the caller to restore it. */
11059 static tree
11061 tree parm_packs,
11063 tree args /* This parm gets
11065 tsubst_flags_t complain,
11066 tree in_decl)
11067 {
11068 tree t;
11071 /* For each parameter pack, change the substitution of the parameter
11072 pack to the ith argument in its argument pack, then expand the
11073 pattern. */
11075 {
11080 ith_elem_is_expansion |=
11083 /* Select the Ith argument from the pack. */
11086 {
11088 {
11093 }
11094 else
11096 }
11097 else
11098 {
11103 {
11105 /* Update the corresponding argument. */
11107 }
11108 else
11109 /* Re-use the ARGUMENT_PACK_SELECT. */
11111 }
11113 }
11115 /* Substitute into the PATTERN with the (possibly altered)
11116 arguments. */
11118 /* Expanding a fixed parameter pack from
11119 coerce_template_parameter_pack. */
11124 {
11127 else
11130 }
11134 else
11137 /* If the Ith argument pack element is a pack expansion, then
11138 the Ith element resulting from the substituting is going to
11139 be a pack expansion as well. */
11144 }
11146 /* When the unexpanded parameter pack in a fold expression expands to an empty
11147 sequence, the value of the expression is as follows; the program is
11148 ill-formed if the operator is not listed in this table.
11150 && true
11151 || false
11152 , void() */
11154 tree
11156 {
11160 {
11169 }
11175 }
11177 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11178 form an expression that combines the two terms using the
11179 operator of T. */
11181 static tree
11183 {
11187 // Handle compound assignment operators.
11192 {
11202 complain);
11203 }
11204 }
11206 /* Substitute ARGS into the pack of a fold expression T. */
11210 {
11212 }
11214 /* Substitute ARGS into the pack of a fold expression T. */
11218 {
11220 }
11222 /* Expand a PACK of arguments into a grouped as left fold.
11223 Given a pack containing elements A0, A1, ..., An and an
11224 operator @, this builds the expression:
11226 ((A0 @ A1) @ A2) ... @ An
11228 Note that PACK must not be empty.
11230 The operator is defined by the original fold expression T. */
11232 static tree
11234 {
11237 {
11240 }
11242 }
11244 /* Substitute into a unary left fold expression. */
11246 static tree
11248 tree in_decl)
11249 {
11254 {
11258 }
11261 else
11263 }
11265 /* Substitute into a binary left fold expression.
11267 Do ths by building a single (non-empty) vector of argumnts and
11268 building the expression from those elements. */
11270 static tree
11272 tree in_decl)
11273 {
11282 {
11287 }
11295 }
11297 /* Expand a PACK of arguments into a grouped as right fold.
11298 Given a pack containing elementns A0, A1, ..., and an
11299 operator @, this builds the expression:
11301 A0@ ... (An-2 @ (An-1 @ An))
11303 Note that PACK must not be empty.
11305 The operator is defined by the original fold expression T. */
11307 tree
11309 {
11310 // Build the expression.
11314 {
11317 }
11319 }
11321 /* Substitute into a unary right fold expression. */
11323 static tree
11325 tree in_decl)
11326 {
11331 {
11335 }
11338 else
11340 }
11342 /* Substitute into a binary right fold expression.
11344 Do ths by building a single (non-empty) vector of arguments and
11345 building the expression from those elements. */
11347 static tree
11349 tree in_decl)
11350 {
11359 {
11364 }
11373 }
11376 /* Substitute ARGS into T, which is an pack expansion
11377 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11378 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11379 (if only a partial substitution could be performed) or
11380 ERROR_MARK_NODE if there was an error. */
11381 tree
11383 tree in_decl)
11384 {
11385 tree pattern;
11389 tree result;
11397 /* Add in any args remembered from an earlier partial instantiation. */
11402 /* Determine the argument packs that will instantiate the parameter
11403 packs used in the expansion expression. While we're at it,
11404 compute the number of arguments to be expanded and make sure it
11405 is consistent. */
11408 {
11415 {
11420 else
11423 }
11425 {
11426 /* ??? Support use in other patterns. */
11430 }
11432 {
11433 /* We know we have correct local_specializations if this
11434 expansion is at function scope, or if we're dealing with a
11435 local parameter in a requires expression; for the latter,
11436 tsubst_requires_expr set it up appropriately. */
11439 else
11440 /* We can't rely on local_specializations for a parameter
11441 name used later in a function declaration (such as in a
11442 late-specified return type). Even if it exists, it might
11443 have the wrong value for a recursive call. */
11447 {
11448 /* This parameter pack was used in an unevaluated context. Just
11449 make a dummy decl, since it's only used for its type. */
11452 /* Partial instantiation of the parm_pack, we can't build
11453 up an argument pack yet. */
11455 else
11457 }
11458 }
11461 else
11462 {
11468 }
11475 /* This can only happen if we forget to expand an argument
11476 pack somewhere else. Just return an error, silently. */
11477 {
11481 }
11484 {
11488 /* Don't bother trying to do a partial substitution with
11489 incomplete packs; we'll try again after deduction. */
11496 {
11501 pattern);
11502 else
11504 pattern);
11506 }
11508 /* Keep track of the parameter packs and their corresponding
11509 argument packs. */
11512 }
11513 else
11514 {
11515 /* We can't substitute for this parameter pack. We use a flag as
11516 well as the missing_level counter because function parameter
11517 packs don't have a level. */
11520 }
11521 }
11523 /* If the expansion is just T..., return the matching argument pack, unless
11524 we need to call convert_from_reference on all the elements. This is an
11525 important optimization; see c++/68422. */
11528 {
11530 /* Types need no adjustment, nor does sizeof..., and if we still have
11531 some pack expansion args we won't do anything yet. */
11536 /* Also optimize expression pack expansions if we can tell that the
11537 elements won't have reference type. */
11543 /* Otherwise use the normal path so we get convert_from_reference. */
11544 }
11546 /* We cannot expand this expansion expression, because we don't have
11547 all of the argument packs we need. */
11549 {
11550 /* We got some full packs, but we can't substitute them in until we
11551 have values for all the packs. So remember these until then. */
11556 }
11558 {
11559 /* There were no real arguments, we're just replacing a parameter
11560 pack with another version of itself. Substitute into the
11561 pattern and return a PACK_EXPANSION_*. The caller will need to
11562 deal with that. */
11566 else
11570 }
11575 {
11576 /* We're in a late-specified return type, so create our own local
11577 specializations map; the current map is either NULL or (in the
11578 case of recursive unification) might have bindings that we don't
11579 want to use or alter. */
11582 }
11584 /* For each argument in each argument pack, substitute into the
11585 pattern. */
11589 {
11591 i,
11593 in_decl);
11596 {
11599 }
11600 }
11602 /* Update ARGS to restore the substitution from parameter packs to
11603 their argument packs. */
11605 {
11611 else
11612 {
11620 /* Update the corresponding argument. */
11624 else
11626 }
11627 }
11630 {
11633 }
11635 /* If the dependent pack arguments were such that we end up with only a
11636 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11642 }
11644 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11645 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11646 parameter packs; all parms generated from a function parameter pack will
11647 have the same DECL_PARM_INDEX. */
11649 tree
11651 {
11653 tree patparm;
11656 {
11662 }
11663 else
11664 {
11669 }
11672 }
11674 /* Make an argument pack out of the TREE_VEC VEC. */
11676 static tree
11678 {
11679 tree pack;
11683 else
11684 {
11687 }
11690 }
11692 /* Return an exact copy of template args T that can be modified
11693 independently. */
11695 static tree
11697 {
11705 {
11710 }
11716 }
11718 /* Substitute ARGS into the vector or list of template arguments T. */
11720 static tree
11722 {
11734 {
11736 tree new_arg;
11741 {
11742 /* Substitute into an expansion expression. */
11746 /* Add to the expanded length adjustment the number of
11747 expanded arguments. We subtract one from this
11748 measurement, because the argument pack expression
11749 itself is already counted as 1 in
11750 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11751 the argument pack is empty. */
11753 }
11755 {
11756 /* Substitute into each of the arguments. */
11765 else
11770 }
11771 else
11780 }
11785 /* Make space for the expanded arguments coming from template
11786 argument packs. */
11788 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11789 arguments for a member template.
11790 In that case each TREE_VEC in ORIG_T represents a level of template
11791 arguments, and ORIG_T won't carry any non defaulted argument count.
11792 It will rather be the nested TREE_VECs that will carry one.
11793 In other words, ORIG_T carries a non defaulted argument count only
11794 if it doesn't contain any nested TREE_VEC. */
11796 {
11800 }
11802 {
11806 {
11809 /* Now expand the template argument pack "in place". */
11812 }
11813 else
11814 {
11816 out++;
11817 }
11818 }
11821 }
11823 /* Substitute ARGS into one level PARMS of template parameters. */
11825 static tree
11827 {
11834 {
11842 }
11845 }
11847 /* Return the result of substituting ARGS into the template parameters
11848 given by PARMS. If there are m levels of ARGS and m + n levels of
11849 PARMS, then the result will contain n levels of PARMS. For
11850 example, if PARMS is `template <class T> template <class U>
11851 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11852 result will be `template <int*, double, class V>'. */
11854 static tree
11856 {
11860 /* When substituting into a template, we must set
11861 PROCESSING_TEMPLATE_DECL as the template parameters may be
11862 dependent if they are based on one-another, and the dependency
11863 predicates are short-circuit outside of templates. */
11870 {
11877 }
11882 }
11884 /* Return the result of substituting ARGS into one template parameter
11885 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11886 parameter and which TREE_PURPOSE is the default argument of the
11887 template parameter. */
11889 static tree
11891 {
11912 }
11914 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11915 type T. If T is not an aggregate or enumeration type, it is
11916 handled as if by tsubst. IN_DECL is as for tsubst. If
11917 ENTERING_SCOPE is nonzero, T is the context for a template which
11918 we are presently tsubst'ing. Return the substituted value. */
11920 static tree
11922 tree args,
11923 tsubst_flags_t complain,
11924 tree in_decl,
11926 {
11931 {
11936 /* Fall through. */
11940 {
11941 tree argvec;
11942 tree context;
11943 tree r;
11947 /* In "sizeof(X<I>)" we need to evaluate "I". */
11953 /* First, determine the context for the type we are looking
11954 up. */
11957 {
11960 /* If context is a nested class inside a class template,
11961 it may still need to be instantiated (c++/33959). */
11963 }
11965 /* Then, figure out what arguments are appropriate for the
11966 type we are trying to find. For example, given:
11968 template <class T> struct S;
11969 template <class T, class U> void f(T, U) { S<U> su; }
11971 and supposing that we are instantiating f<int, double>,
11972 then our ARGS will be {int, double}, but, when looking up
11973 S we only want {double}. */
11978 else
11979 {
11983 }
11989 }
11990 else
11991 /* This is not a template type, so there's nothing to do. */
11996 }
11997 }
11999 /* Substitute into the default argument ARG (a default argument for
12000 FN), which has the indicated TYPE. */
12002 tree
12004 {
12009 /* This can happen in invalid code. */
12013 /* This default argument came from a template. Instantiate the
12014 default argument here, not in tsubst. In the case of
12015 something like:
12017 template <class T>
12018 struct S {
12019 static T t();
12020 void f(T = t());
12021 };
12023 we must be careful to do name lookup in the scope of S<T>,
12024 rather than in the current class. */
12026 /* The "this" pointer is not valid in a default argument. */
12028 {
12033 }
12036 /* The default argument expression may cause implicitly defined
12037 member functions to be synthesized, which will result in garbage
12038 collection. We must treat this situation as if we were within
12039 the body of function so as to avoid collecting live data on the
12040 stack. */
12048 /* Restore the "this" pointer. */
12050 {
12053 }
12060 /* Make sure the default argument is reasonable. */
12066 }
12068 /* Substitute into all the default arguments for FN. */
12070 static void
12072 {
12073 tree arg;
12074 tree tmpl_args;
12078 /* If this function is not yet instantiated, we certainly don't need
12079 its default arguments. */
12082 /* Don't do this again for clones. */
12087 arg;
12093 complain);
12094 }
12096 /* Substitute the ARGS into the T, which is a _DECL. Return the
12097 result of the substitution. Issue error and warning messages under
12098 control of COMPLAIN. */
12100 static tree
12102 {
12103 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12104 location_t saved_loc;
12109 /* Set the filename and linenumber to improve error-reporting. */
12114 {
12116 {
12117 /* We can get here when processing a member function template,
12118 member class template, or template template parameter. */
12120 tree spec;
12121 tree tmpl_args;
12122 tree full_args;
12125 {
12126 /* Template template parameter is treated here. */
12130 /* If we get a real template back, return it. This can happen in
12131 the context of most_specialized_partial_spec. */
12134 else
12135 /* The new TEMPLATE_DECL was built in
12136 reduce_template_parm_level. */
12139 }
12141 /* We might already have an instance of this template.
12142 The ARGS are for the surrounding class type, so the
12143 full args contain the tsubst'd args for the context,
12144 plus the innermost args from the template decl. */
12148 /* Because this is a template, the arguments will still be
12149 dependent, even after substitution. If
12150 PROCESSING_TEMPLATE_DECL is not set, the dependency
12151 predicates will short-circuit. */
12159 /* If this is a default template template argument,
12160 tsubst might not have changed anything. */
12167 {
12170 }
12172 /* Make a new template decl. It will be similar to the
12173 original, but will record the current template arguments.
12174 We also create a new function declaration, which is just
12175 like the old one, but points to this new template, rather
12176 than the old one. */
12181 // Build new template info linking to the original template decl.
12186 {
12187 tree new_type;
12195 /* For a partial specialization, we need to keep pointing to
12196 the primary template. */
12202 }
12203 else
12204 {
12205 tree new_decl;
12217 }
12223 /* The template parameters for this new template are all the
12224 template parameters for the old template, except the
12225 outermost level of parameters. */
12228 complain);
12234 /* Record this non-type partial instantiation. */
12238 }
12242 {
12243 tree ctx;
12246 tree gen_tmpl;
12247 tree type;
12252 /* Nobody should be tsubst'ing into non-template functions. */
12256 {
12257 tree spec;
12259 /* If T is not dependent, just return it. */
12263 /* Calculate the most general template of which R is a
12264 specialization, and the complete set of arguments used to
12265 specialize R. */
12268 (DECL_TEMPLATE_RESULT
12274 /* Check to see if we already have this specialization. */
12279 {
12282 }
12284 /* We can see more levels of arguments than parameters if
12285 there was a specialization of a member template, like
12286 this:
12288 template <class T> struct S { template <class U> void f(); }
12289 template <> template <class U> void S<int>::f(U);
12291 Here, we'll be substituting into the specialization,
12292 because that's where we can find the code we actually
12293 want to generate, but we'll have enough arguments for
12294 the most general template.
12296 We also deal with the peculiar case:
12298 template <class T> struct S {
12299 template <class U> friend void f();
12300 };
12301 template <class U> void f() {}
12302 template S<int>;
12303 template void f<double>();
12305 Here, the ARGS for the instantiation of will be {int,
12306 double}. But, we only need as many ARGS as there are
12307 levels of template parameters in CODE_PATTERN. We are
12308 careful not to get fooled into reducing the ARGS in
12309 situations like:
12311 template <class T> struct S { template <class U> void f(U); }
12312 template <class T> template <> void S<T>::f(int) {}
12314 which we can spot because the pattern will be a
12315 specialization in this case. */
12317 parms_depth =
12322 }
12323 else
12324 {
12325 /* This special case arises when we have something like this:
12327 template <class T> struct S {
12328 friend void f<int>(int, double);
12329 };
12331 Here, the DECL_TI_TEMPLATE for the friend declaration
12332 will be an IDENTIFIER_NODE. We are being called from
12333 tsubst_friend_function, and we want only to create a
12334 new decl (R) with appropriate types so that we can call
12335 determine_specialization. */
12337 }
12340 {
12343 else
12347 }
12348 else
12349 {
12352 }
12357 /* If we hit excessive deduction depth, the type is bogus even if
12358 it isn't error_mark_node, so don't build a decl. */
12362 /* We do NOT check for matching decls pushed separately at this
12363 point, as they may not represent instantiations of this
12364 template, and in any case are considered separate under the
12365 discrete model. */
12369 /* Clear out the mangled name and RTL for the instantiation. */
12372 /* Leave DECL_INITIAL set on deleted instantiations. */
12377 /* OpenMP UDRs have the only argument a reference to the declared
12378 type. We want to diagnose if the declared type is a reference,
12379 which is invalid, but as references to references are usually
12380 quietly merged, diagnose it here. */
12382 {
12383 tree argtype
12388 "reference type %qT in "
12392 argtype);
12393 }
12396 /* Type-conversion operator. Reconstruct the name, in
12397 case it's the name of one of the template's parameters. */
12407 /* If this is an instantiation of a function with internal
12408 linkage, we already know what object file linkage will be
12409 assigned to the instantiation. */
12418 /* We'll re-clone as appropriate in instantiate_template. */
12421 /* If we aren't complaining now, return on error before we register
12422 the specialization so that we'll complain eventually. */
12428 /* When instantiating a constrained member, substitute
12429 into the constraints to create a new constraint. */
12432 {
12435 }
12437 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12438 this in the special friend case mentioned above where
12439 GEN_TMPL is NULL. */
12441 {
12446 tree new_r
12449 /* We instantiated this while substituting into
12450 the type earlier (template/friend54.C). */
12453 /* We're not supposed to instantiate default arguments
12454 until they are called, for a template. But, for a
12455 declaration like:
12457 template <class T> void f ()
12458 { extern void g(int i = T()); }
12460 we should do the substitution when the template is
12461 instantiated. We handle the member function case in
12462 instantiate_class_template since the default arguments
12463 might refer to other members of the class. */
12468 }
12469 else
12472 /* Copy the list of befriending classes. */
12476 {
12480 in_decl);
12481 }
12484 {
12488 /* If this is an instantiation of a member template, clone it.
12489 If it isn't, that'll be handled by
12490 clone_constructors_and_destructors. */
12493 }
12504 /* Possibly limit visibility based on template args. */
12507 {
12511 }
12519 }
12523 {
12531 {
12532 /* If there is a local specialization that isn't a
12533 parameter pack, it means that we're doing a "simple"
12534 substitution from inside tsubst_pack_expansion. Just
12535 return the local specialization (which will be a single
12536 parm). */
12543 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12544 the parameters in this function parameter pack. */
12548 {
12551 /* Zero-length parameter packs are boring. Just substitute
12552 into the chain. */
12556 }
12557 else
12558 {
12559 /* All we did was update the type. Make a note of that. */
12562 }
12563 }
12565 /* Loop through all of the parameters we'll build. When T is
12566 a function parameter pack, LEN is the number of expanded
12567 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12570 {
12577 /* We're on the Ith parameter of the function parameter
12578 pack. */
12579 {
12580 /* Get the Ith type. */
12583 /* Rename the parameter to include the index. */
12586 }
12588 /* We're dealing with a normal parameter. */
12596 {
12599 else
12602 }
12612 /* Keep track of the first new parameter we
12613 generate. That's what will be returned to the
12614 caller. */
12618 /* Build a proper chain of parameters when substituting
12619 into a function parameter pack. */
12622 }
12624 /* If cp_unevaluated_operand is set, we're just looking for a
12625 single dummy parameter, so don't keep going. */
12630 /* FIRST_R contains the start of the chain we've built. */
12632 }
12636 {
12643 {
12644 /* This field is a lambda capture pack. Return a TREE_VEC of
12645 the expanded fields to instantiate_class_template_1 and
12646 store them in the specializations hash table as a
12647 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12651 {
12654 }
12655 else
12656 {
12657 /* All we did was update the type. Make a note of that. */
12660 }
12661 }
12664 {
12667 {
12671 }
12681 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12682 non-bit-fields DECL_INITIAL is a non-static data member
12683 initializer, which gets deferred instantiation. */
12689 {
12690 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12691 NSDMI in perform_member_init. Still set DECL_INITIAL
12692 so that we know there is one. */
12697 }
12698 /* We don't have to set DECL_CONTEXT here; it is set by
12699 finish_member_declaration. */
12707 }
12710 {
12715 }
12716 }
12720 /* We reach here only for member using decls. We also need to check
12721 uses_template_parms because DECL_DEPENDENT_P is not set for a
12722 using-declaration that designates a member of the current
12723 instantiation (c++/53549). */
12726 {
12730 {
12735 {
12739 {
12742 }
12743 else
12744 {
12747 }
12749 }
12750 }
12751 else
12752 {
12758 else
12759 {
12762 }
12763 }
12764 }
12765 else
12766 {
12769 }
12774 {
12777 tree spec;
12779 tree ctx;
12788 {
12789 /* If this is the canonical decl, we don't have to
12790 mess with instantiations, and often we can't (for
12791 typename, template type parms and such). Note that
12792 TYPE_NAME is not correct for the above test if
12793 we've copied the type for a typedef. */
12799 }
12801 /* Check to see if we already have the specialization we
12802 need. */
12805 {
12806 /* T is a static data member or namespace-scope entity.
12807 We have to substitute into namespace-scope variables
12808 (not just variable templates) because of cases like:
12810 template <class T> void f() { extern T t; }
12812 where the entity referenced is not known until
12813 instantiation time. */
12817 {
12819 complain,
12821 /* If CTX is unchanged, then T is in fact the
12822 specialization we want. That situation occurs when
12823 referencing a static data member within in its own
12824 class. We can use pointer equality, rather than
12825 same_type_p, because DECL_CONTEXT is always
12826 canonical... */
12828 /* ... unless T is a member template; in which
12829 case our caller can be willing to create a
12830 specialization of that template represented
12831 by T. */
12835 }
12838 {
12843 argvec = (coerce_innermost_template_parms
12851 }
12852 }
12853 else
12854 {
12855 /* A local variable. */
12857 /* Subsequent calls to pushdecl will fill this in. */
12859 /* Unless this is a reference to a static variable from an
12860 enclosing function, in which case we need to fill it in now. */
12862 {
12866 }
12868 }
12869 /* If we already have the specialization we need, there is
12870 nothing more to do. */
12872 {
12875 }
12877 /* Create a new node for the specialization we need. */
12880 {
12883 else
12890 }
12892 {
12893 /* Even if the original location is out of scope, the
12894 newly substituted one is not. */
12901 {
12902 /* It may seem that this case cannot occur, since:
12904 typedef void f();
12905 void g() { f x; }
12907 declares a function, not a variable. However:
12909 typedef void f();
12910 template <typename T> void g() { T t; }
12911 template void g<f>();
12913 is an attempt to declare a variable with function
12914 type. */
12916 /* R is not yet sufficiently initialized, so we
12917 just use its name. */
12920 }
12922 /* Wait until cp_finish_decl to set this again, to handle
12923 circular dependency (template/instantiate6.C). */
12928 {
12933 {
12936 }
12938 }
12942 }
12948 /* Clear out the mangled name and RTL for the instantiation. */
12952 /* The initializer must not be expanded until it is required;
12953 see [temp.inst]. */
12961 {
12962 /* Possibly limit visibility based on template args. */
12965 {
12969 }
12971 }
12974 {
12975 /* A static data member declaration is always marked
12976 external when it is declared in-class, even if an
12977 initializer is present. We mimic the non-template
12978 processing here. */
12986 }
12987 else
12988 {
12993 }
13001 /* Preserve a typedef that names a type. */
13003 {
13007 /* An alias template specialization can be dependent
13008 even if its underlying type is not. */
13010 }
13013 }
13018 }
13019 #undef RETURN
13021 out:
13022 /* Restore the file and line information. */
13026 }
13028 /* Substitute into the ARG_TYPES of a function type.
13029 If END is a TREE_CHAIN, leave it and any following types
13030 un-substituted. */
13032 static tree
13034 tree args,
13035 tree end,
13036 tsubst_flags_t complain,
13037 tree in_decl)
13038 {
13039 tree remaining_arg_types;
13043 tree default_arg;
13054 {
13055 /* For a pack expansion, perform substitution on the
13056 entire expression. Later on, we'll handle the arguments
13057 one-by-one. */
13062 /* So that we'll spin through the parameters, one by one. */
13064 else
13065 {
13066 /* We only partially substituted into the parameter
13067 pack. Our type is TYPE_PACK_EXPANSION. */
13070 }
13071 }
13084 {
13086 {
13090 }
13092 }
13093 /* DR 657. */
13097 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13098 top-level qualifiers as required. */
13101 /* We do not substitute into default arguments here. The standard
13102 mandates that they be instantiated only when needed, which is
13103 done in build_over_call. */
13107 {
13108 /* We've instantiated a template before its default arguments
13109 have been parsed. This can happen for a nested template
13110 class, and is not an error unless we require the default
13111 argument in a call of this function. */
13112 remaining_arg_types =
13115 }
13116 else
13117 remaining_arg_types =
13119 }
13122 }
13124 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13125 *not* handle the exception-specification for FNTYPE, because the
13126 initial substitution of explicitly provided template parameters
13127 during argument deduction forbids substitution into the
13128 exception-specification:
13130 [temp.deduct]
13132 All references in the function type of the function template to the
13133 corresponding template parameters are replaced by the specified tem-
13134 plate argument values. If a substitution in a template parameter or
13135 in the function type of the function template results in an invalid
13136 type, type deduction fails. [Note: The equivalent substitution in
13137 exception specifications is done only when the function is instanti-
13138 ated, at which point a program is ill-formed if the substitution
13139 results in an invalid type.] */
13141 static tree
13143 tree args,
13144 tsubst_flags_t complain,
13145 tree in_decl)
13146 {
13147 tree return_type;
13149 tree fntype;
13151 /* The TYPE_CONTEXT is not used for function/method types. */
13154 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13155 failure. */
13159 {
13160 /* Substitute the argument types. */
13172 {
13173 /* DR 1207: 'this' is in scope in the trailing return type. */
13175 }
13177 /* Substitute the return type. */
13181 {
13184 }
13185 }
13186 else
13187 /* Substitute the return type. */
13192 /* DR 486 clarifies that creation of a function type with an
13193 invalid return type is a deduction failure. */
13196 {
13198 {
13201 else
13203 }
13205 }
13206 /* And DR 657. */
13211 {
13212 /* Substitute the argument types. */
13217 }
13219 /* Construct a new type node and return it. */
13221 {
13226 }
13227 else
13228 {
13230 /* Don't pick up extra function qualifiers from the basetype. */
13233 {
13234 /* [temp.deduct]
13236 Type deduction may fail for any of the following
13237 reasons:
13239 -- Attempting to create "pointer to member of T" when T
13240 is not a class type. */
13243 r);
13245 }
13250 }
13257 }
13259 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13260 ARGS into that specification, and return the substituted
13261 specification. If there is no specification, return NULL_TREE. */
13263 static tree
13265 tree args,
13266 tsubst_flags_t complain,
13267 tree in_decl,
13269 {
13270 tree specs;
13271 tree new_specs;
13276 {
13277 /* A noexcept-specifier. */
13282 {
13283 /* Defer instantiation of noexcept-specifiers to avoid
13284 excessive instantiations (c++/49107). */
13287 {
13288 /* We already partially instantiated this member template,
13289 so combine the new args with the old. */
13294 }
13295 else
13296 {
13299 }
13300 }
13301 else
13302 new_specs = tsubst_copy_and_build
13306 }
13308 {
13311 else
13313 {
13314 tree spec;
13319 {
13320 /* Expand the pack expansion type. */
13323 in_decl);
13329 else
13330 {
13331 /* We're substituting into a member template, so
13332 we got a TYPE_PACK_EXPANSION back. Add that
13333 expansion and move on. */
13337 expanded_specs,
13338 complain);
13341 }
13342 }
13345 {
13348 else
13353 complain);
13354 }
13357 }
13358 }
13360 }
13362 /* Take the tree structure T and replace template parameters used
13363 therein with the argument vector ARGS. IN_DECL is an associated
13364 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13365 Issue error and warning messages under control of COMPLAIN. Note
13366 that we must be relatively non-tolerant of extensions here, in
13367 order to preserve conformance; if we allow substitutions that
13368 should not be allowed, we may allow argument deductions that should
13369 not succeed, and therefore report ambiguous overload situations
13370 where there are none. In theory, we could allow the substitution,
13371 but indicate that it should have failed, and allow our caller to
13372 make sure that the right thing happens, but we don't try to do this
13373 yet.
13375 This function is used for dealing with types, decls and the like;
13376 for expressions, use tsubst_expr or tsubst_copy. */
13378 tree
13380 {
13403 else
13408 /* Reuse typedefs. We need to do this to handle dependent attributes,
13409 such as attribute aligned. */
13412 {
13416 {
13417 /* DECL represents an alias template and we want to
13418 instantiate it. */
13422 }
13426 {
13430 }
13435 else
13436 /* The typedef is from a non-template context. */
13440 {
13442 r = cp_build_qualified_type_real
13446 }
13447 else
13448 {
13449 /* We don't have an instantiation yet, so drop the typedef. */
13454 }
13455 }
13472 {
13498 {
13504 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13505 needed. */
13511 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13512 with TREE_SIDE_EFFECTS that indicates this is not an integral
13513 constant expression. */
13516 {
13519 }
13522 }
13528 {
13534 /* Early in template argument deduction substitution, we don't
13535 want to reduce the level of 'auto', or it will be confused
13536 with a normal template parm in subsequent deduction. */
13548 {
13552 {
13553 /* See through ARGUMENT_PACK_SELECT arguments. */
13555 /* If the selected argument is an expansion E, that most
13556 likely means we were called from
13557 gen_elem_of_pack_expansion_instantiation during the
13558 substituting of pack an argument pack (which Ith
13559 element is a pack expansion, where I is
13560 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13561 In this case, the Ith element resulting from this
13562 substituting is going to be a pack expansion, which
13563 pattern is the pattern of E. Let's return the
13564 pattern of E, and
13565 gen_elem_of_pack_expansion_instantiation will
13566 build the resulting pack expansion from it. */
13568 {
13569 /* Make sure we aren't throwing away arg info. */
13572 }
13573 }
13574 }
13579 {
13581 /* If ARG is an argument pack, we don't actually want to
13582 perform a substitution here, because substitutions
13583 for argument packs are only done
13584 element-by-element. We can get to this point when
13585 substituting the type of a non-type template
13586 parameter pack, when that type actually contains
13587 template parameter packs from an outer template, e.g.,
13589 template<typename... Types> struct A {
13590 template<Types... Values> struct B { };
13591 }; */
13595 {
13601 return cp_build_qualified_type_real
13603 }
13605 {
13606 /* We are processing a type constructed from a
13607 template template parameter. */
13618 /* Consider this code:
13620 template <template <class> class Template>
13621 struct Internal {
13622 template <class Arg> using Bind = Template<Arg>;
13623 };
13625 template <template <class> class Template, class Arg>
13626 using Instantiate = Template<Arg>; //#0
13628 template <template <class> class Template,
13629 class Argument>
13630 using Bind =
13631 Instantiate<Internal<Template>::template Bind,
13632 Argument>; //#1
13634 When #1 is parsed, the
13635 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13636 parameter `Template' in #0 matches the
13637 UNBOUND_CLASS_TEMPLATE representing the argument
13638 `Internal<Template>::template Bind'; We then want
13639 to assemble the type `Bind<Argument>' that can't
13640 be fully created right now, because
13641 `Internal<Template>' not being complete, the Bind
13642 template cannot be looked up in that context. So
13643 we need to "store" `Bind<Argument>' for later
13644 when the context of Bind becomes complete. Let's
13645 store that in a TYPENAME_TYPE. */
13649 argvec),
13650 typename_type,
13651 complain);
13653 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13654 are resolving nested-types in the signature of a
13655 member function templates. Otherwise ARG is a
13656 TEMPLATE_DECL and is the real template to be
13657 instantiated. */
13665 complain);
13666 return cp_build_qualified_type_real
13668 }
13671 else
13672 /* TEMPLATE_PARM_INDEX. */
13674 }
13677 /* This can happen during the attempted tsubst'ing in
13678 unify. This means that we don't yet have any information
13679 about the template parameter in question. */
13682 /* If we get here, we must have been looking at a parm for a
13683 more deeply nested template. Make a new version of this
13684 template parameter, but with a lower level. */
13686 {
13691 {
13693 r = cp_build_qualified_type_real
13697 }
13704 /* Break infinite recursion when substituting the constraints
13706 else
13707 {
13718 {
13719 /* Propagate constraints on placeholders. */
13724 {
13728 }
13729 }
13732 /* We have reduced the level of the template
13733 template parameter, but not the levels of its
13734 template parameters, so canonical_type_parameter
13735 will not be able to find the canonical template
13736 template parameter for this level. Thus, we
13737 require structural equality checking to compare
13738 TEMPLATE_TEMPLATE_PARMs. */
13742 else
13746 {
13748 /* We might need to substitute into the types of non-type
13749 template parameters. */
13761 }
13762 }
13766 /* OK, now substitute the type of the non-type parameter. We
13767 couldn't do it earlier because it might be an auto parameter,
13768 and we wouldn't need to if we had an argument. */
13775 }
13778 }
13781 {
13789 {
13793 }
13796 {
13800 }
13803 {
13807 }
13813 }
13816 /* We should never be tsubsting a binfo. */
13820 /* A vector of template arguments. */
13826 {
13830 /* [temp.deduct]
13832 Type deduction may fail for any of the following
13833 reasons:
13835 -- Attempting to create a pointer to reference type.
13836 -- Attempting to create a reference to a reference type or
13837 a reference to void.
13839 Core issue 106 says that creating a reference to a reference
13840 during instantiation is no longer a cause for failure. We
13841 only enforce this check in strict C++98 mode. */
13845 {
13848 /* We keep track of the last time we issued this error
13849 message to avoid spewing a ton of messages during a
13850 single bad template instantiation. */
13853 {
13858 else
13861 }
13864 }
13868 {
13870 {
13873 type);
13874 else
13876 type);
13877 }
13879 }
13881 {
13885 }
13887 /* In C++0x, during template argument substitution, when there is an
13888 attempt to create a reference to a reference type, reference
13889 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13891 "If a template-argument for a template-parameter T names a type
13892 that is a reference to a type A, an attempt to create the type
13893 'lvalue reference to cv T' creates the type 'lvalue reference to
13894 A,' while an attempt to create the type type rvalue reference to
13895 cv T' creates the type T"
13896 */
13897 r = cp_build_reference_type
13900 else
13905 /* Will this ever be needed for TYPE_..._TO values? */
13909 }
13911 {
13914 {
13915 /* [temp.deduct]
13917 Type deduction may fail for any of the following
13918 reasons:
13920 -- Attempting to create "pointer to member of T" when T
13921 is not a class type. */
13925 }
13927 {
13931 }
13933 {
13937 }
13940 {
13941 /* The type of the implicit object parameter gets its
13942 cv-qualifiers from the FUNCTION_TYPE. */
13943 tree memptr;
13944 tree method_type
13949 complain);
13950 }
13951 else
13954 complain);
13955 }
13958 {
13959 tree fntype;
13960 tree specs;
13965 /* Substitute the exception specification. */
13973 }
13975 {
13980 /* As an optimization, we avoid regenerating the array type if
13981 it will obviously be the same as T. */
13985 /* These checks should match the ones in create_array_type_for_decl.
13987 [temp.deduct]
13989 The deduction may fail for any of the following reasons:
13991 -- Attempting to create an array with an element type that
13992 is void, a function type, or a reference type, or [DR337]
13993 an abstract class type. */
13999 {
14003 }
14011 {
14014 }
14017 }
14020 {
14032 {
14036 }
14038 {
14039 /* Normally, make_typename_type does not require that the CTX
14040 have complete type in order to allow things like:
14042 template <class T> struct S { typename S<T>::X Y; };
14044 But, such constructs have already been resolved by this
14045 point, so here CTX really should have complete type, unless
14046 it's a partial instantiation. */
14049 {
14053 }
14054 }
14061 {
14064 }
14067 {
14069 {
14073 else
14075 }
14077 {
14081 else
14083 }
14084 }
14086 return cp_build_qualified_type_real
14088 }
14091 {
14103 }
14106 {
14107 tree type;
14123 complain);
14124 }
14127 {
14128 tree type;
14139 {
14141 {
14145 }
14148 }
14159 else
14160 {
14164 /* In a template ~id could be either a complement expression
14165 or an unqualified-id naming a destructor; if instantiating
14166 it produces an expression, it's not an id-expression or
14167 member access. */
14170 }
14175 }
14178 {
14182 }
14186 {
14187 tree r;
14191 else
14199 }
14214 /* We should use one of the expression tsubsts for these codes. */
14220 }
14221 }
14223 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
14224 type of the expression on the left-hand side of the "." or "->"
14225 operator. */
14227 static tree
14230 {
14231 tree name;
14232 tree qualifying_scope;
14233 tree fns;
14234 tree optype;
14239 /* A baselink indicates a function from a base class. Both the
14240 BASELINK_ACCESS_BINFO and the base class referenced may
14241 indicate bases of the template class, rather than the
14242 instantiated class. In addition, lookups that were not
14243 ambiguous before may be ambiguous now. Therefore, we perform
14244 the lookup again. */
14251 {
14258 }
14264 {
14266 {
14270 }
14272 }
14274 /* If lookup found a single function, mark it as used at this
14275 point. (If it lookup found multiple functions the one selected
14276 later by overload resolution will be marked as used at that
14277 point.) */
14284 /* Add back the template arguments, if present. */
14288 unknown_type_node,
14290 template_args);
14291 /* Update the conversion operator type. */
14299 {
14301 qualifying_scope,
14302 object_type);
14304 /* We need to call adjust_result_of_qualified_name_lookup in case the
14305 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14306 so that we still get virtual function binding. */
14308 }
14310 }
14312 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14313 true if the qualified-id will be a postfix-expression in-and-of
14314 itself; false if more of the postfix-expression follows the
14315 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14316 of "&". */
14318 static tree
14322 {
14323 tree expr;
14324 tree scope;
14325 tree name;
14327 tree template_args;
14332 /* Figure out what name to look up. */
14335 {
14345 }
14346 else
14347 {
14350 }
14352 /* Substitute into the qualifying scope. When there are no ARGS, we
14353 are just trying to simplify a non-dependent expression. In that
14354 case the qualifying scope may be dependent, and, in any case,
14355 substituting will not help. */
14358 {
14361 }
14362 else
14366 {
14373 }
14376 {
14378 {
14379 /* A BIT_NOT_EXPR is used to represent a destructor. */
14381 {
14385 }
14386 else
14389 }
14390 else
14394 {
14396 {
14400 }
14402 }
14403 }
14406 {
14408 scope);
14409 /* Remember that there was a reference to this entity. */
14412 }
14415 {
14421 }
14424 {
14427 complain);
14428 else
14430 }
14436 {
14437 expr = (adjust_result_of_qualified_name_lookup
14439 expr = (finish_qualified_id_expr
14443 }
14445 /* Expressions do not generally have reference type. */
14447 /* However, if we're about to form a pointer-to-member, we just
14448 want the referenced member referenced. */
14456 }
14458 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14459 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14460 for tsubst. */
14462 static tree
14465 {
14472 {
14473 /* If we had an initializer but it
14474 instantiated to nothing,
14475 value-initialize the object. This will
14476 only occur when the initializer was a
14477 pack expansion where the parameter packs
14478 used in that expansion were of length
14479 zero. */
14481 complain);
14486 }
14489 }
14491 /* Like tsubst, but deals with expressions. This function just replaces
14492 template parms; to finish processing the resultant expression, use
14493 tsubst_copy_and_build or tsubst_expr. */
14495 static tree
14497 {
14499 tree r;
14507 {
14512 {
14513 /* We get here for a use of 'this' in an NSDMI as part of a
14514 constructor call or as part of an aggregate initialization. */
14516 && ((current_function_decl
14518 || (current_class_ref
14522 /* This can happen for a parameter name used later in a function
14523 declaration (such as in a late-specified return type). Just
14524 make a dummy decl, since it's only used for its type. */
14527 /* Give it the template pattern as its context; its true context
14528 hasn't been instantiated yet and this is good enough for
14529 mangling. */
14531 }
14540 {
14541 tree enum_type;
14542 tree v;
14546 /* There is no need to substitute into namespace-scope
14547 enumerators. */
14550 /* If ARGS is NULL, then T is known to be non-dependent. */
14554 /* Unfortunately, we cannot just call lookup_name here.
14555 Consider:
14557 template <int I> int f() {
14558 enum E { a = I };
14559 struct S { void g() { E e = a; } };
14560 };
14562 When we instantiate f<7>::S::g(), say, lookup_name is not
14563 clever enough to find f<7>::a. */
14564 enum_type
14574 /* We didn't find the name. That should never happen; if
14575 name-lookup found it during preliminary parsing, we
14576 should find it again here during instantiation. */
14578 }
14583 {
14584 /* Check for a local specialization set up by
14585 tsubst_pack_expansion. */
14587 {
14591 }
14593 /* When retrieving a capture pack from a generic lambda, remove the
14594 lambda call op's own template argument list from ARGS. Only the
14595 template arguments active for the closure type should be used to
14596 retrieve the pack specialization. */
14602 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14603 tsubst_decl put in the hash table. */
14605 }
14608 {
14609 tree ctx;
14614 {
14617 {
14621 }
14623 }
14624 }
14634 {
14637 {
14638 /* First try name lookup to find the instantiation. */
14641 {
14642 /* Make sure that the one we found is the one we want. */
14648 }
14652 else
14653 {
14654 /* This can happen for a variable used in a
14655 late-specified return type of a local lambda, or for a
14656 local static or constant. Building a new VAR_DECL
14657 should be OK in all those cases. */
14660 /* Avoid infinite recursion (79640). */
14663 {
14664 /* We can't call cp_finish_decl, so handle the
14665 initializer by hand. */
14676 }
14683 }
14684 /* Remember this for subsequent uses. */
14687 }
14688 }
14689 else
14699 /* An OVERLOAD will always be a non-dependent overload set; an
14700 overload set from function scope will just be represented with an
14701 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14703 /* We must have marked any lookups as persistent. */
14719 {
14720 /* Template template argument like the following example need
14721 special treatment:
14723 template <template <class> class TT> struct C {};
14724 template <class T> struct D {
14725 template <class U> struct E {};
14726 C<E> c; // #1
14727 };
14728 D<int> d; // #2
14730 We are processing the template argument `E' in #1 for
14731 the template instantiation #2. Originally, `E' is a
14732 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14733 have to substitute this with one having context `D<int>'. */
14737 {
14738 /* When rewriting a constructor into a deduction guide, a
14739 non-dependent name can become dependent, so memtmpl<args>
14740 becomes context::template memtmpl<args>. */
14744 }
14746 }
14747 else
14748 /* Ordinary template template argument. */
14759 {
14763 }
14768 {
14777 /* We only want to compute the number of arguments. */
14780 else
14787 {
14789 /* Set TREE_USED for the benefit of -Wunused. */
14793 }
14801 {
14806 else
14812 else
14815 }
14816 else
14818 }
14820 {
14828 }
14829 /* Fall through */
14845 {
14849 }
14852 {
14853 tree object;
14854 tree name;
14859 {
14863 }
14866 {
14876 }
14881 in_decl);
14882 else
14885 }
14923 {
14927 }
14930 {
14935 }
14938 {
14942 }
14945 {
14953 }
14959 {
14966 }
14969 {
14976 }
14979 {
14986 }
14989 {
14990 /* Substituted template arguments */
14999 }
15002 {
15022 }
15047 /* Fall through. */
15050 {
15053 }
15054 else
15058 /* This is handled by tsubst_copy_and_build. */
15062 {
15066 }
15069 /* We shouldn't have built any of these during initial template
15070 generation. Instead, they should be built during instantiation
15071 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15075 {
15085 }
15103 {
15104 /* Instantiate any typedefs in the type. */
15109 }
15112 /* These can sometimes show up in a partial instantiation, but never
15113 involve template parms. */
15127 /* We shouldn't get here, but keep going if !flag_checking. */
15131 }
15132 }
15134 /* Helper function for tsubst_omp_clauses, used for instantiation of
15135 OMP_CLAUSE_DECL of clauses. */
15137 static tree
15139 tree in_decl)
15140 {
15144 /* Handle an OpenMP array section represented as a TREE_LIST (or
15145 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15146 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15147 TREE_LIST. We can handle it exactly the same as an array section
15148 (purpose, value, and a chain), even though the nomenclature
15149 (low_bound, length, etc) is different. */
15151 {
15152 tree low_bound
15158 in_decl);
15167 }
15170 /* Undo convert_from_reference tsubst_expr could have called. */
15176 }
15178 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15180 static tree
15183 {
15188 {
15194 {
15197 {
15203 }
15204 /* FALLTHRU */
15219 in_decl);
15251 {
15254 {
15261 }
15262 else
15264 }
15267 in_decl);
15273 in_decl);
15281 in_decl);
15283 {
15286 }
15291 else
15294 in_decl,
15318 }
15321 {
15331 /* tsubst_expr on SCOPE_REF results in returning
15332 finish_non_static_data_member result. Undo that here. */
15336 {
15341 {
15345 CASE_CONVERT:
15354 /* FALLTHRU */
15358 }
15359 }
15365 {
15368 {
15371 }
15372 }
15376 }
15377 }
15381 {
15386 {
15389 }
15390 }
15392 }
15394 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15396 static tree
15398 tree in_decl)
15399 {
15400 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15420 {
15423 else
15424 {
15428 }
15429 }
15434 #undef RECUR
15435 }
15437 /* Used to temporarily communicate the list of #pragma omp parallel
15438 clauses to #pragma omp for instantiation if they are combined
15439 together. */
15443 /* Substitute one OMP_FOR iterator. */
15445 static void
15450 {
15451 #define RECUR(NODE) \
15452 tsubst_expr ((NODE), args, complain, in_decl, \
15453 integral_constant_expression_p)
15460 {
15463 }
15469 {
15470 /* We need to jump through some hoops to handle declarations in the
15471 init-statement, since we might need to handle auto deduction,
15472 but we need to keep control of initialization. */
15476 }
15477 else
15478 {
15480 {
15483 {
15487 {
15491 CASE_CONVERT:
15499 {
15502 }
15503 /* FALLTHRU */
15507 }
15508 }
15509 }
15510 else
15512 }
15523 {
15525 {
15526 /* Declare the variable, but don't let that initialize it. */
15531 }
15536 {
15541 }
15542 else
15549 }
15552 {
15553 /* Declare and initialize the variable. */
15556 }
15558 {
15562 {
15564 {
15570 {
15573 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15578 }
15581 {
15583 decl);
15585 }
15588 {
15590 decl);
15592 }
15593 else
15595 }
15598 }
15600 {
15605 {
15608 }
15609 }
15610 }
15613 {
15617 }
15618 else
15622 {
15633 {
15641 }
15642 else
15648 {
15654 }
15658 {
15666 }
15667 else
15673 }
15679 #undef RECUR
15680 }
15682 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15683 of OMP_TARGET's body. */
15685 static tree
15687 {
15690 {
15699 }
15701 }
15703 /* Helper function for tsubst_expr. For decomposition declaration
15704 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15705 also the corresponding decls representing the identifiers
15706 of the decomposition declaration. Return DECL if successful
15707 or error_mark_node otherwise, set *FIRST to the first decl
15708 in the list chained through DECL_CHAIN and *CNT to the number
15709 of such decls. */
15711 static tree
15715 {
15720 decl2
15725 {
15727 {
15730 }
15747 {
15750 }
15751 else
15753 }
15756 }
15758 /* Like tsubst_copy for expressions, etc. but also does semantic
15759 processing. */
15761 tree
15764 {
15765 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15766 #define RECUR(NODE) \
15767 tsubst_expr ((NODE), args, complain, in_decl, \
15768 integral_constant_expression_p)
15771 tree r;
15772 location_t loc;
15784 {
15786 {
15787 tree_stmt_iterator i;
15791 }
15806 else
15816 {
15818 tree init;
15824 {
15834 else
15836 }
15838 {
15839 /* Don't build up decls for a variadic capture proxy, we'll
15840 instantiate the elements directly as needed. */
15842 }
15843 else
15844 {
15848 {
15849 /* By marking the declaration as instantiated, we avoid
15850 trying to instantiate it. Since instantiate_decl can't
15851 handle local variables, and since we've already done
15852 all that needs to be done, that's the right thing to
15853 do. */
15858 /* Anonymous aggregates are a special case. */
15861 {
15864 {
15868 }
15870 }
15876 {
15881 }
15882 else
15883 {
15888 {
15889 /* For __PRETTY_FUNCTION__ we have to adjust the
15890 initializer. */
15894 }
15895 else
15899 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15905 {
15907 tree first;
15913 }
15914 }
15915 }
15916 }
15919 }
15934 {
15942 {
15944 tree first;
15949 }
15950 else
15955 }
15981 else
15982 {
15989 }
15995 {
16004 }
16012 else
16020 else
16041 {
16048 }
16052 {
16054 tree label;
16061 }
16067 /* Computed goto's must be tsubst'd into. On the other hand,
16068 non-computed gotos must not be; the identifier in question
16069 will have no binding. */
16071 else
16077 {
16093 }
16098 {
16103 }
16104 else
16105 {
16110 else
16117 else
16123 else
16125 }
16129 {
16133 {
16135 /* Prevent instantiate_decl from trying to instantiate
16136 this variable. We've already done all that needs to be
16137 done. */
16140 }
16145 }
16151 {
16152 /* Local classes are not independent templates; they are
16153 instantiated along with their containing function. And this
16154 way we don't have to deal with pushing out of one local class
16155 to instantiate a member of another local class. */
16156 tree fn;
16157 /* Closures are handled by the LAMBDA_EXPR. */
16164 }
16168 {
16169 tree condition;
16172 condition =
16174 args,
16183 }
16189 in_decl);
16226 {
16241 in_decl);
16243 {
16250 }
16262 integral_constant_expression_p);
16273 else
16274 {
16282 }
16286 }
16291 /* FALLTHRU */
16298 in_decl);
16315 in_decl);
16326 {
16329 {
16330 /* For combined target teams, ensure the num_teams and
16331 thread_limit clause expressions are evaluated on the host,
16332 before entering the target construct. */
16333 tree c;
16339 {
16348 OMP_CLAUSE_FIRSTPRIVATE);
16352 }
16353 }
16354 }
16414 {
16419 {
16422 }
16428 }
16429 else
16430 {
16437 {
16440 }
16443 {
16448 {
16451 }
16457 }
16458 else
16459 {
16463 }
16466 }
16470 {
16476 {
16480 {
16485 }
16489 }
16490 else
16491 {
16496 }
16497 }
16501 {
16505 }
16525 /* If the first operand was a statement, we're done with it. */
16529 complain));
16541 integral_constant_expression_p));
16542 }
16545 out:
16548 #undef RECUR
16549 #undef RETURN
16550 }
16552 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16553 function. For description of the body see comment above
16554 cp_parser_omp_declare_reduction_exprs. */
16556 static void
16558 {
16564 tree_stmt_iterator tsi;
16575 {
16594 }
16596 {
16616 }
16617 }
16619 /* T is a postfix-expression that is not being used in a function
16620 call. Return the substituted version of T. */
16622 static tree
16624 tsubst_flags_t complain,
16625 tree in_decl)
16626 {
16630 else
16636 }
16638 /* Like tsubst but deals with expressions and performs semantic
16639 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16641 tree
16643 tree args,
16644 tsubst_flags_t complain,
16645 tree in_decl,
16648 {
16649 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16650 #define RECUR(NODE) \
16651 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16653 integral_constant_expression_p)
16656 location_t loc;
16665 /* N3276 decltype magic only applies to calls at the top level or on the
16666 right side of a comma. */
16671 {
16674 /* Fall through. */
16676 {
16677 tree decl;
16678 cp_id_kind idk;
16683 {
16686 }
16688 /* Look up the name. */
16691 /* By convention, expressions use ERROR_MARK_NODE to indicate
16692 failure, not NULL_TREE. */
16698 integral_constant_expression_p,
16706 input_location);
16710 {
16714 }
16716 }
16719 {
16720 tree object;
16730 {
16735 }
16741 {
16744 }
16745 else
16752 else
16754 }
16757 {
16761 {
16762 /* A type conversion to reference type will be enclosed in
16763 such an indirect ref, but the substitution of the cast
16764 will have also added such an indirect ref. */
16767 }
16768 else
16776 }
16779 {
16783 }
16786 {
16793 flags));
16794 }
16797 {
16801 }
16808 {
16809 tree type;
16815 {
16820 }
16826 {
16844 }
16847 }
16881 else
16883 in_decl);
16918 {
16925 tree r = build_x_binary_op
16927 op0,
16929 ? ERROR_MARK
16931 op1,
16933 ? ERROR_MARK
16941 }
16944 {
16948 }
16961 {
16970 }
16975 /* Fall through */
16978 {
16979 tree r;
16985 {
16986 /* When there are no ARGS, we are trying to evaluate a
16987 non-dependent expression from the parser. Trying to do
16988 the substitutions may not work. */
16991 }
16992 else
16993 {
16998 else
17001 /*integral_constant_expression_p=*/
17005 }
17009 else
17013 {
17015 {
17017 {
17021 }
17022 else
17026 }
17028 }
17030 }
17033 {
17043 }
17059 {
17063 tree r = build_x_modify_expr
17066 /* TREE_NO_WARNING must be set if either the expression was
17067 parenthesized or it uses an operator such as >>= rather
17068 than plain assignment. In the former case, it was already
17069 set and must be copied. In the latter case,
17070 build_x_modify_expr sets it and it must not be reset
17071 here. */
17076 }
17081 /* Remember that there was a reference to this entity. */
17088 {
17093 tree ret;
17097 else
17098 {
17102 }
17104 /* If there was an initializer in the original tree, but it
17105 instantiated to an empty list, then we should pass a
17106 non-NULL empty vector to tell build_new that it was an
17107 empty initializer() rather than no initializer. This can
17108 only happen when the initializer is a pack expansion whose
17109 parameter packs are of length zero. */
17112 else
17113 {
17117 else
17118 {
17121 }
17122 }
17128 complain);
17136 }
17139 {
17145 complain));
17146 }
17149 {
17153 integral_constant_expression_p);
17155 op0,
17158 }
17161 {
17162 tree function;
17167 tree ret;
17170 /* Internal function with no arguments. */
17174 /* When we parsed the expression, we determined whether or
17175 not Koenig lookup should be performed. */
17178 {
17181 }
17183 {
17188 }
17190 {
17191 /* Do nothing; calling tsubst_copy_and_build on an identifier
17192 would incorrectly perform unqualified lookup again.
17194 Note that we can also have an IDENTIFIER_NODE if the earlier
17195 unqualified lookup found a member function; in that case
17196 koenig_p will be false and we do want to do the lookup
17197 again to find the instantiated member function.
17199 FIXME but doing that causes c++/15272, so we need to stop
17200 using IDENTIFIER_NODE in that situation. */
17202 }
17203 else
17204 {
17206 {
17212 }
17213 else
17218 /* Avoid error about taking the address of a constructor. */
17222 in_decl,
17224 integral_constant_expression_p);
17228 }
17233 {
17238 else
17239 {
17240 /* Expand the pack expansion and push each entry onto
17241 CALL_ARGS. */
17244 {
17249 {
17254 }
17255 }
17256 else
17257 {
17258 /* A partial substitution. Add one entry. */
17260 }
17261 }
17262 }
17264 /* We do not perform argument-dependent lookup if normal
17265 lookup finds a non-function, in accordance with the
17266 expected resolution of DR 218. */
17269 /* If lookup found a member function, the Koenig lookup is
17270 not appropriate, even if an unqualified-name was used
17271 to denote the function. */
17274 /* Only do this when substitution turns a dependent call
17275 into a non-dependent call. */
17283 {
17285 {
17286 /* For backwards compatibility and good diagnostics, try
17287 the unqualified lookup again if we aren't in SFINAE
17288 context. */
17289 tree unq = (tsubst_copy_and_build
17291 integral_constant_expression_p));
17293 {
17296 }
17299 {
17300 /* In a lambda fn, we have to be careful to not
17301 introduce new this captures. Legacy code can't
17302 be using lambdas anyway, so it's ok to be
17303 stricter. */
17308 "and no declarations were found by "
17309 "argument-dependent lookup at the point "
17316 else
17320 {
17331 {
17333 input_location);
17335 "declarations in dependent base %qT are "
17341 else
17345 }
17346 else
17348 "%qD declared here, later in the "
17351 {
17354 }
17355 }
17358 }
17359 }
17361 {
17366 }
17367 }
17369 /* Remember that there was a reference to this entity. */
17373 {
17376 }
17378 /* Put back tf_decltype for the actual call. */
17383 {
17387 {
17389 "wrong number of arguments to "
17392 }
17393 else
17395 input_location),
17400 /* Unsupported internal function with arguments. */
17402 }
17405 complain);
17407 {
17422 complain);
17423 else
17424 ret = (build_new_method_call
17429 complain));
17430 }
17431 else
17434 koenig_p,
17435 complain);
17440 {
17446 {
17452 {
17454 /* The thunk location is not interesting. */
17456 }
17457 }
17458 }
17461 }
17464 {
17470 {
17472 {
17477 }
17478 else
17479 {
17484 }
17486 }
17487 else
17488 {
17491 }
17495 }
17498 {
17503 input_location));
17504 }
17507 {
17515 {
17516 /* We have pack expansions, so expand those and
17517 create a new list out of it. */
17520 tree chain;
17523 /* Expand the argument expressions. */
17531 /* Build the rest of the list. */
17536 /* Determine the number of arguments. */
17538 {
17541 }
17544 else
17545 {
17546 /* Since we only performed a partial substitution into
17547 the argument pack, we only RETURN (a single list
17548 node. */
17555 }
17557 /* Convert the argument vectors into a TREE_LIST */
17560 {
17561 /* Grab the Ith values. */
17562 i--;
17565 value
17569 /* Build the list (backwards). */
17571 }
17574 }
17590 }
17593 {
17594 tree object;
17595 tree object_type;
17596 tree member;
17597 tree r;
17601 /* Remember that there was a reference to this entity. */
17612 else
17618 {
17623 }
17627 {
17629 {
17634 {
17637 }
17639 {
17644 }
17645 }
17646 }
17649 {
17650 /* Lookup the template functions now that we know what the
17651 scope is. */
17659 {
17662 args);
17663 member = (adjust_result_of_qualified_name_lookup
17665 object_type));
17666 }
17667 else
17668 {
17670 input_location);
17672 }
17673 }
17677 {
17679 {
17683 else
17686 }
17688 }
17692 complain);
17696 }
17703 {
17711 tree r;
17716 /* digest_init will do the wrong thing if we let it. */
17720 /* We do not want to process the index of aggregate
17721 initializers as they are identifier nodes which will be
17722 looked up by digest_init. */
17728 {
17730 /* An identifier index is looked up in the type
17731 being initialized, not the current scope. */
17736 {
17737 /* Substitute into the pack expansion. */
17739 in_decl);
17743 ;
17745 /* Just move the argument into place. */
17747 else
17748 {
17749 /* Update the length of the final CONSTRUCTOR
17750 arguments vector, and note that we will need to
17751 copy.*/
17754 }
17755 }
17756 else
17758 }
17761 {
17766 {
17768 {
17773 }
17774 else
17776 }
17777 }
17783 {
17788 }
17792 }
17795 {
17798 {
17801 }
17802 else
17803 {
17806 }
17807 }
17813 {
17814 /* We don't build decls for an instantiation of a
17815 variadic capture proxy, we instantiate the elements
17816 when needed. */
17819 }
17820 /* Fall through */
17823 {
17825 /* ??? We're doing a subset of finish_id_expression here. */
17827 && !processing_template_decl
17828 && !cp_unevaluated_operand
17831 {
17833 /* Replace an evaluated use of the thread_local variable with
17834 a call to its wrapper. */
17836 }
17838 {
17842 }
17845 /* If the original type was a reference, we'll be wrapped in
17846 the appropriate INDIRECT_REF. */
17849 }
17852 {
17856 }
17859 {
17860 tree object_ptr
17867 }
17874 {
17885 }
17888 {
17894 integral_constant_expression_p);
17898 /* If the resulting list of expression statement is empty,
17899 fold it further into void_node. */
17904 }
17907 {
17925 /* For a function or variable scope, we want to use tsubst so that we
17926 don't complain about referring to an auto before deduction. */
17929 {
17930 /* Look up the parameter we want directly, as tsubst_copy
17931 doesn't do what we need. */
17937 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17940 }
17942 /* For a field, use tsubst_copy so that we look up the existing field
17943 rather than build a new one. */
17945 else
17952 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17954 /* Now that we know visibility, instantiate the type so we have a
17955 declaration of the op() for later calls to lambda_function. */
17966 }
17969 /* We can get here for a constant initializer of non-dependent type.
17970 FIXME stop folding in cp_parser_initializer_clause. */
17971 {
17973 complain);
17975 }
17979 integral_constant_expression_p));
17985 {
17990 complain));
17991 }
17997 /* Handle Objective-C++ constructs, if appropriate. */
17998 {
17999 tree subst
18004 }
18006 }
18008 #undef RECUR
18009 #undef RETURN
18010 out:
18013 }
18015 /* Verify that the instantiated ARGS are valid. For type arguments,
18016 make sure that the type's linkage is ok. For non-type arguments,
18017 make sure they are constants if they are integral or enumerations.
18018 Emit an error under control of COMPLAIN, and return TRUE on error. */
18020 static bool
18022 {
18026 {
18036 }
18038 {
18039 /* [basic.link]: A name with no linkage (notably, the name
18040 of a class or enumeration declared in a local scope)
18041 shall not be used to declare an entity with linkage.
18042 This implies that names with no linkage cannot be used as
18043 template arguments
18045 DR 757 relaxes this restriction for C++0x. */
18050 {
18051 /* DR 488 makes use of a type with no linkage cause
18052 type deduction to fail. */
18054 {
18057 else
18060 }
18062 }
18063 /* In order to avoid all sorts of complications, we do not
18064 allow variably-modified types as template arguments. */
18066 {
18070 }
18071 }
18072 /* Class template and alias template arguments should be OK. */
18074 ;
18075 /* A non-type argument of integral or enumerated type must be a
18076 constant. */
18081 {
18085 }
18087 }
18089 static bool
18091 {
18096 {
18099 }
18103 }
18105 /* We're out of SFINAE context now, so generate diagnostics for the access
18106 errors we saw earlier when instantiating D from TMPL and ARGS. */
18108 static void
18110 {
18122 }
18124 /* Instantiate the indicated variable, function, or alias template TMPL with
18125 the template arguments in TARG_PTR. */
18127 static tree
18129 {
18131 tree fndecl;
18132 tree gen_tmpl;
18133 tree spec;
18141 /* If this function is a clone, handle it specially. */
18143 {
18144 tree spec;
18145 tree clone;
18147 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18148 DECL_CLONED_FUNCTION. */
18154 /* Look for the clone. */
18158 /* We should always have found the clone by now. */
18161 }
18166 /* Check to see if we already have this specialization. */
18170 /* targ_ptr only has the innermost template args, so add the outer ones
18171 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18172 the case of a non-dependent call within a template definition). */
18173 targ_ptr = (add_outermost_template_args
18175 targ_ptr));
18177 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18178 but it doesn't seem to be on the hot path. */
18187 {
18189 {
18193 }
18195 }
18198 complain))
18201 /* We are building a FUNCTION_DECL, during which the access of its
18202 parameters and return types have to be checked. However this
18203 FUNCTION_DECL which is the desired context for access checking
18204 is not built yet. We solve this chicken-and-egg problem by
18205 deferring all checks until we have the FUNCTION_DECL. */
18208 /* Instantiation of the function happens in the context of the function
18209 template, not the context of the overload resolution we're doing. */
18211 /* If there are dependent arguments, e.g. because we're doing partial
18212 ordering, make sure processing_template_decl stays set. */
18216 {
18220 }
18226 {
18227 /* We need to determine if we're using a partial or explicit
18228 specialization now, because the type of the variable could be
18229 different. */
18235 {
18240 }
18241 }
18243 /* Substitute template parameters to obtain the specialization. */
18251 {
18254 }
18256 /* The DECL_TI_TEMPLATE should always be the immediate parent
18257 template, not the most general template. */
18261 /* Now we know the specialization, compute access previously
18262 deferred. Do no access control for inheriting constructors,
18263 as we already checked access for the inherited constructor. */
18266 {
18271 }
18274 /* If we've just instantiated the main entry point for a function,
18275 instantiate all the alternate entry points as well. We do this
18276 by cloning the instantiation of the main entry point, not by
18277 instantiating the template clones. */
18282 {
18284 {
18285 /* Remember to reinstantiate when we're out of SFINAE so the user
18286 can see the errors. */
18288 }
18290 }
18292 }
18294 /* Wrapper for instantiate_template_1. */
18296 tree
18298 {
18299 tree ret;
18304 }
18306 /* Instantiate the alias template TMPL with ARGS. Also push a template
18307 instantiation level, which instantiate_template doesn't do because
18308 functions and variables have sufficient context established by the
18309 callers. */
18311 static tree
18313 {
18320 {
18323 }
18325 args =
18333 /* We can't free this if a pending_template entry or last_error_tinst_level
18334 is pointing at it. */
18340 }
18342 /* PARM is a template parameter pack for FN. Returns true iff
18343 PARM is used in a deducible way in the argument list of FN. */
18345 static bool
18347 {
18350 {
18352 tree packs;
18358 {
18359 /* The template parameter pack is used in a function parameter
18360 pack. If this is the end of the parameter list, the
18361 template parameter pack is deducible. */
18364 else
18365 /* Otherwise, not. Well, it could be deduced from
18366 a non-pack parameter, but doing so would end up with
18367 a deduction mismatch, so don't bother. */
18369 }
18370 }
18371 /* The template parameter pack isn't used in any function parameter
18372 packs, but it might be used deeper, e.g. tuple<Args...>. */
18374 }
18376 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18377 NARGS elements of the arguments that are being used when calling
18378 it. TARGS is a vector into which the deduced template arguments
18379 are placed.
18381 Returns either a FUNCTION_DECL for the matching specialization of FN or
18382 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18383 true, diagnostics will be printed to explain why it failed.
18385 If FN is a conversion operator, or we are trying to produce a specific
18386 specialization, RETURN_TYPE is the return type desired.
18388 The EXPLICIT_TARGS are explicit template arguments provided via a
18389 template-id.
18391 The parameter STRICT is one of:
18393 DEDUCE_CALL:
18394 We are deducing arguments for a function call, as in
18395 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18396 deducing arguments for a call to the result of a conversion
18397 function template, as in [over.call.object].
18399 DEDUCE_CONV:
18400 We are deducing arguments for a conversion function, as in
18401 [temp.deduct.conv].
18403 DEDUCE_EXACT:
18404 We are deducing arguments when doing an explicit instantiation
18405 as in [temp.explicit], when determining an explicit specialization
18406 as in [temp.expl.spec], or when taking the address of a function
18407 template, as in [temp.deduct.funcaddr]. */
18409 tree
18411 tree explicit_targs,
18412 tree targs,
18415 tree return_type,
18416 unification_kind_t strict,
18420 {
18421 tree parms;
18422 tree fntype;
18435 tree tinst;
18441 full_targs = (add_outermost_template_args
18443 targs));
18448 /* In C++0x, it's possible to have a function template whose type depends
18449 on itself recursively. This is most obvious with decltype, but can also
18450 occur with enumeration scope (c++/48969). So we need to catch infinite
18451 recursion and reject the substitution at deduction time; this function
18452 will return error_mark_node for any repeated substitution.
18454 This also catches excessive recursion such as when f<N> depends on
18455 f<N-1> across all integers, and returns error_mark_node for all the
18456 substitutions back up to the initial one.
18458 This is, of course, not reentrant. */
18468 {
18469 /* [temp.deduct]
18471 The specified template arguments must match the template
18472 parameters in kind (i.e., type, nontype, template), and there
18473 must not be more arguments than there are parameters;
18474 otherwise type deduction fails.
18476 Nontype arguments must match the types of the corresponding
18477 nontype template parameters, or must be convertible to the
18478 types of the corresponding nontype parameters as specified in
18479 _temp.arg.nontype_, otherwise type deduction fails.
18481 All references in the function type of the function template
18482 to the corresponding template parameters are replaced by the
18483 specified template argument values. If a substitution in a
18484 template parameter or in the function type of the function
18485 template results in an invalid type, type deduction fails. */
18496 explicit_targs);
18498 /* Adjust any explicit template arguments before entering the
18499 substitution context. */
18500 explicit_targs
18502 complain,
18508 /* Substitute the explicit args into the function type. This is
18509 necessary so that, for instance, explicitly declared function
18510 arguments can match null pointed constants. If we were given
18511 an incomplete set of explicit args, we must not do semantic
18512 processing during substitution as we could create partial
18513 instantiations. */
18515 {
18520 /* Dig out the actual parm. */
18523 {
18526 }
18528 {
18531 }
18534 /* No explicit argument for this template parameter. */
18538 {
18539 /* Mark the argument pack as "incomplete". We could
18540 still deduce more arguments during unification.
18541 We remove this mark in type_unification_real. */
18543 {
18547 }
18549 /* We have some incomplete argument packs. */
18551 }
18552 }
18556 {
18559 }
18562 /* Ignore any access checks; we'll see them again in
18563 instantiate_template and they might have the wrong
18564 access path at this point. */
18576 /* Place the explicitly specified arguments in TARGS. */
18580 }
18582 /* Never do unification on the 'this' parameter. */
18586 {
18587 /* We're deducing for a call to the result of a template conversion
18588 function. The parms we really want are in return_type. */
18592 }
18594 {
18603 }
18605 /* We allow incomplete unification without an error message here
18606 because the standard doesn't seem to explicitly prohibit it. Our
18607 callers must be ready to deal with unification failures in any
18608 event. */
18611 /* If we aren't explaining yet, push tinst context so we can see where
18612 any errors (e.g. from class instantiations triggered by instantiation
18613 of default template arguments) come from. If we are explaining, this
18614 context is redundant. */
18616 {
18619 }
18621 /* type_unification_real will pass back any access checks from default
18622 template argument substitution. */
18634 /* Now that we have bindings for all of the template arguments,
18635 ensure that the arguments deduced for the template template
18636 parameters have compatible template parameter lists. We cannot
18637 check this property before we have deduced all template
18638 arguments, because the template parameter types of a template
18639 template parameter might depend on prior template parameters
18640 deduced after the template template parameter. The following
18641 ill-formed example illustrates this issue:
18643 template<typename T, template<T> class C> void f(C<5>, T);
18645 template<int N> struct X {};
18647 void g() {
18648 f(X<5>(), 5l); // error: template argument deduction fails
18649 }
18651 The template parameter list of 'C' depends on the template type
18652 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18653 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18654 time that we deduce 'C'. */
18657 {
18660 }
18662 /* All is well so far. Now, check:
18664 [temp.deduct]
18666 When all template arguments have been deduced, all uses of
18667 template parameters in nondeduced contexts are replaced with
18668 the corresponding deduced argument values. If the
18669 substitution results in an invalid type, as described above,
18670 type deduction fails. */
18673 {
18676 }
18678 /* Also collect access checks from the instantiation. */
18691 /* Now perform any access checks encountered during substitution. */
18698 /* If we're looking for an exact match, check that what we got
18699 is indeed an exact match. It might not be if some template
18700 parameters are used in non-deduced contexts. But don't check
18701 for an exact match if we have dependent template arguments;
18702 in that case we're doing partial ordering, and we already know
18703 that we have two candidates that will provide the actual type. */
18705 {
18709 tree sarg
18715 {
18719 }
18720 }
18722 /* After doing deduction with the inherited constructor, actually return an
18723 instantiation of the inheriting constructor. */
18729 fail:
18732 {
18734 /* Reset once we're all the way out. */
18736 }
18738 /* We can't free this if a pending_template entry or last_error_tinst_level
18739 is pointing at it. */
18745 }
18747 /* Adjust types before performing type deduction, as described in
18748 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18749 sections are symmetric. PARM is the type of a function parameter
18750 or the return type of the conversion function. ARG is the type of
18751 the argument passed to the call, or the type of the value
18752 initialized with the result of the conversion function.
18753 ARG_EXPR is the original argument expression, which may be null. */
18755 static int
18759 tree arg_expr)
18760 {
18764 {
18769 /* Swap PARM and ARG throughout the remainder of this
18770 function; the handling is precisely symmetric since PARM
18771 will initialize ARG rather than vice versa. */
18776 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18777 too, but here handle it by stripping the reference from PARM
18778 rather than by adding it to ARG. */
18786 /* Nothing else to do in this case. */
18791 }
18794 {
18795 /* [temp.deduct.call]
18797 If P is not a reference type:
18799 --If A is an array type, the pointer type produced by the
18800 array-to-pointer standard conversion (_conv.array_) is
18801 used in place of A for type deduction; otherwise,
18803 --If A is a function type, the pointer type produced by
18804 the function-to-pointer standard conversion
18805 (_conv.func_) is used in place of A for type deduction;
18806 otherwise,
18808 --If A is a cv-qualified type, the top level
18809 cv-qualifiers of A's type are ignored for type
18810 deduction. */
18815 else
18817 }
18819 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18820 reference to a cv-unqualified template parameter that does not represent a
18821 template parameter of a class template (during class template argument
18822 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18823 an lvalue, the type "lvalue reference to A" is used in place of A for type
18824 deduction. */
18831 /* try_one_overload doesn't provide an arg_expr, but
18832 functions are always lvalues. */
18836 /* [temp.deduct.call]
18838 If P is a cv-qualified type, the top level cv-qualifiers
18839 of P's type are ignored for type deduction. If P is a
18840 reference type, the type referred to by P is used for
18841 type deduction. */
18844 {
18847 }
18849 /* DR 322. For conversion deduction, remove a reference type on parm
18850 too (which has been swapped into ARG). */
18855 }
18857 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18858 template which does contain any deducible template parameters; check if
18859 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18860 unify_one_argument. */
18862 static int
18865 {
18866 tree type;
18870 else
18877 {
18881 }
18883 {
18888 }
18892 else
18894 }
18898 /* Returns true iff the expression EXPR is one from which a template
18899 argument can be deduced. In other words, if it's an undecorated
18900 use of a template non-type parameter. */
18902 static bool
18904 {
18905 /* Strip implicit conversions. */
18909 }
18911 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18912 deducible way; that is, if it has a max value of <PARM> - 1. */
18914 static bool
18916 {
18925 }
18927 /* Returns true iff the template arguments ARGS use a template parameter
18928 in a deducible way. */
18930 static bool
18932 {
18934 {
18939 else
18940 {
18947 else
18949 }
18952 }
18954 }
18956 /* Returns true iff TYPE contains any deducible references to template
18957 parameters, as per 14.8.2.5. */
18959 static bool
18961 {
18965 /* T
18966 cv-list T
18967 TT<T>
18968 TT<i>
18969 TT<> */
18974 /* T*
18975 T&
18976 T&& */
18980 /* T[integer-constant ]
18981 type [i] */
18986 /* T type ::*
18987 type T::*
18988 T T::*
18989 T (type ::*)()
18990 type (T::*)()
18991 type (type ::*)(T)
18992 type (T::*)(T)
18993 T (type ::*)(T)
18994 T (T::*)()
18995 T (T::*)(T) */
18998 || (uses_deducible_template_parms
19001 /* template-name <T> (where template-name refers to a class template)
19002 template-name <i> (where template-name refers to a class template) */
19009 /* type (T)
19010 T()
19011 T(T) */
19014 {
19023 }
19026 }
19028 /* Subroutine of type_unification_real and unify_pack_expansion to
19029 handle unification of a single P/A pair. Parameters are as
19030 for those functions. */
19032 static int
19036 {
19043 /* We can't deduce anything from this, but we might get all the
19044 template args from other function args. */
19047 /* Implicit conversions (Clause 4) will be performed on a function
19048 argument to convert it to the type of the corresponding function
19049 parameter if the parameter type contains no template-parameters that
19050 participate in template argument deduction. */
19053 /* For function parameters with no deducible template parameters,
19054 just return. We'll check non-dependent conversions later. */
19058 {
19060 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19061 | UNIFY_ALLOW_MORE_CV_QUAL
19075 }
19077 /* We only do these transformations if this is the top-level
19078 parameter_type_list in a call or declaration matching; in other
19079 situations (nested function declarators, template argument lists) we
19080 won't be comparing a type to an expression, and we don't do any type
19081 adjustments. */
19083 {
19085 {
19088 {
19089 /* [temp.deduct.type] A template-argument can be
19090 deduced from a pointer to function or pointer
19091 to member function argument if the set of
19092 overloaded functions does not contain function
19093 templates and at most one of a set of
19094 overloaded functions provides a unique
19095 match. */
19102 }
19108 }
19110 arg_strict |=
19112 }
19113 else
19118 /* For deduction from an init-list we need the actual list. */
19122 }
19124 /* for_each_template_parm callback that always returns 0. */
19126 static int
19128 {
19130 }
19132 /* for_each_template_parm any_fn callback to handle deduction of a template
19133 type argument from the type of an array bound. */
19135 static int
19137 {
19145 {
19151 }
19153 /* Keep walking. */
19155 }
19157 /* Try to deduce any not-yet-deduced template type arguments from the type of
19158 an array bound. This is handled separately from unify because 14.8.2.5 says
19159 "The type of a type parameter is only deduced from an array bound if it is
19160 not otherwise deduced." */
19162 static void
19164 {
19169 }
19171 /* Most parms like fn_type_unification.
19173 If SUBR is 1, we're being called recursively (to unify the
19174 arguments of a function or method parameter of a function
19175 template).
19177 CHECKS is a pointer to a vector of access checks encountered while
19178 substituting default template arguments. */
19180 static int
19182 tree full_targs,
19183 tree xparms,
19187 unification_kind_t strict,
19191 {
19196 tree parms;
19207 /* Reset the number of non-defaulted template arguments contained
19208 in TARGS. */
19211 again:
19219 {
19224 /* For a function parameter pack that occurs at the end of the
19225 parameter-declaration-list, the type A of each remaining
19226 argument of the call is compared with the type P of the
19227 declarator-id of the function parameter pack. */
19233 /* For a function parameter pack that does not occur at the
19234 end of the parameter-declaration-list, the type of the
19235 parameter pack is a non-deduced context. */
19242 explain_p))
19244 }
19249 {
19250 /* Unify the remaining arguments with the pack expansion type. */
19251 tree argvec;
19254 /* Allocate a TREE_VEC and copy in all of the arguments */
19259 /* Copy the parameter into parmvec. */
19265 /* Advance to the end of the list of parameters. */
19267 }
19269 /* Fail if we've reached the end of the parm list, and more args
19270 are present, and the parm list isn't variadic. */
19273 /* Fail if parms are left and they don't have default values and
19274 they aren't all deduced as empty packs (c++/57397). This is
19275 consistent with sufficient_parms_p. */
19278 {
19282 do
19283 {
19286 count++;
19288 }
19292 type_pack_p);
19293 }
19296 {
19297 tsubst_flags_t complain = (explain_p
19298 ? tf_warning_or_error
19303 {
19307 /* Clear the "incomplete" flags on all argument packs now so that
19308 substituting them into later default arguments works. */
19310 {
19313 }
19321 {
19326 }
19328 /* If this is an undeduced nontype parameter that depends on
19329 a type parameter, try another pass; its type may have been
19330 deduced from a later argument than the one from which
19331 this parameter can be deduced. */
19335 {
19338 }
19340 /* Core issue #226 (C++0x) [temp.deduct]:
19342 If a template argument has not been deduced, its
19343 default template argument, if any, is used.
19345 When we are in C++98 mode, TREE_PURPOSE will either
19346 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19347 to explicitly check cxx_dialect here. */
19349 /* OK, there is a default argument. Wait until after the
19350 conversion check to do substitution. */
19353 /* If the type parameter is a parameter pack, then it will
19354 be deduced to an empty parameter pack. */
19356 {
19357 tree arg;
19360 {
19363 }
19364 else
19371 }
19374 }
19376 /* DR 1391: All parameters have args, now check non-dependent parms for
19377 convertibility. */
19381 {
19387 /* For a function parameter pack that occurs at the end of the
19388 parameter-declaration-list, the type A of each remaining
19389 argument of the call is compared with the type P of the
19390 declarator-id of the function parameter pack. */
19396 /* For a function parameter pack that does not occur at the
19397 end of the parameter-declaration-list, the type of the
19398 parameter pack is a non-deduced context. */
19407 explain_p))
19409 }
19411 /* Now substitute into the default template arguments. */
19413 {
19437 else
19445 {
19447 /* The position of the first default template argument,
19448 is also the number of non-defaulted arguments in TARGS.
19449 Record that. */
19452 }
19453 }
19457 }
19463 }
19465 /* Subroutine of type_unification_real. Args are like the variables
19466 at the call site. ARG is an overloaded function (or template-id);
19467 we try deducing template args from each of the overloads, and if
19468 only one succeeds, we go with that. Modifies TARGS and returns
19469 true on success. */
19471 static bool
19473 tree targs,
19474 tree parm,
19475 tree arg,
19476 unification_kind_t strict,
19479 {
19486 {
19489 }
19490 else
19494 /* Handle `&x' where `x' is some static or non-static member
19495 function name. */
19501 /* Strip baselink information. */
19506 {
19507 /* If we got some explicit template args, we need to plug them into
19508 the affected templates before we try to unify, in case the
19509 explicit args will completely resolve the templates in question. */
19516 {
19529 {
19534 {
19537 }
19538 }
19541 }
19542 /* If no templates (or more than one) are fully resolved by the
19543 explicit arguments, this template-id is a non-deduced context; it
19544 could still be OK if we deduce all template arguments for the
19545 enclosing call through other arguments. */
19548 }
19551 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19552 -- but the deduction does not succeed because the expression is
19553 not just the function on its own. */
19555 else
19557 {
19562 {
19565 }
19566 }
19568 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19569 to function or pointer to member function argument if the set of
19570 overloaded functions does not contain function templates and at most
19571 one of a set of overloaded functions provides a unique match.
19573 So if we found multiple possibilities, we return success but don't
19574 deduce anything. */
19577 {
19581 {
19586 /* Don't forget explicit template arguments in a pack. */
19590 }
19591 }
19596 }
19598 /* Core DR 115: In contexts where deduction is done and fails, or in
19599 contexts where deduction is not done, if a template argument list is
19600 specified and it, along with any default template arguments, identifies
19601 a single function template specialization, then the template-id is an
19602 lvalue for the function template specialization. */
19604 tree
19606 {
19619 {
19622 }
19624 {
19627 }
19629 {
19632 }
19635 {
19639 /* If we got some explicit template args, we need to plug them into
19640 the affected templates before we try to unify, in case the
19641 explicit args will completely resolve the templates in question. */
19649 {
19662 {
19665 {
19668 }
19670 {
19673 }
19674 }
19675 }
19677 {
19685 {
19686 tree base
19689 }
19693 }
19695 /* There were no good options and at least one bad one, so let the
19696 user know what the problem is. */
19698 }
19700 }
19702 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19703 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19704 different overloads deduce different arguments for a given parm.
19705 ADDR_P is true if the expression for which deduction is being
19706 performed was of the form "& fn" rather than simply "fn".
19708 Returns 1 on success. */
19710 static int
19712 tree orig_targs,
19713 tree targs,
19714 tree parm,
19715 tree arg,
19716 unification_kind_t strict,
19720 {
19722 tree tempargs;
19728 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19729 to function or pointer to member function argument if the set of
19730 overloaded functions does not contain function templates and at most
19731 one of a set of overloaded functions provides a unique match.
19733 So if this is a template, just return success. */
19745 /* We don't copy orig_targs for this because if we have already deduced
19746 some template args from previous args, unify would complain when we
19747 try to deduce a template parameter for the same argument, even though
19748 there isn't really a conflict. */
19755 /* First make sure we didn't deduce anything that conflicts with
19756 explicitly specified args. */
19758 {
19765 /* Since we're unifying against ourselves, we will fill in
19766 template args used in the function parm list with our own
19767 template parms. Discard them. */
19770 {
19771 /* Check that the argument at each index of the deduced argument pack
19772 is equivalent to the corresponding explicitly specified argument.
19773 We may have deduced more arguments than were explicitly specified,
19774 and that's OK. */
19776 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19777 that's wrong if we deduce the same argument pack from multiple
19778 function arguments: it's only incomplete the first time. */
19791 }
19794 }
19797 {
19802 }
19805 }
19807 /* PARM is a template class (perhaps with unbound template
19808 parameters). ARG is a fully instantiated type. If ARG can be
19809 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19810 TARGS are as for unify. */
19812 static tree
19815 {
19816 tree copy_of_targs;
19826 /* We need to make a new template argument vector for the call to
19827 unify. If we used TARGS, we'd clutter it up with the result of
19828 the attempted unification, even if this class didn't work out.
19829 We also don't want to commit ourselves to all the unifications
19830 we've already done, since unification is supposed to be done on
19831 an argument-by-argument basis. In other words, consider the
19832 following pathological case:
19834 template <int I, int J, int K>
19835 struct S {};
19837 template <int I, int J>
19838 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19840 template <int I, int J, int K>
19841 void f(S<I, J, K>, S<I, I, I>);
19843 void g() {
19844 S<0, 0, 0> s0;
19845 S<0, 1, 2> s2;
19847 f(s0, s2);
19848 }
19850 Now, by the time we consider the unification involving `s2', we
19851 already know that we must have `f<0, 0, 0>'. But, even though
19852 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19853 because there are two ways to unify base classes of S<0, 1, 2>
19854 with S<I, I, I>. If we kept the already deduced knowledge, we
19855 would reject the possibility I=1. */
19859 {
19863 }
19865 /* If unification failed, we're done. */
19871 }
19873 /* Given a template type PARM and a class type ARG, find the unique
19874 base type in ARG that is an instance of PARM. We do not examine
19875 ARG itself; only its base-classes. If there is not exactly one
19876 appropriate base class, return NULL_TREE. PARM may be the type of
19877 a partial specialization, as well as a plain template type. Used
19878 by unify. */
19880 static enum template_base_result
19883 {
19885 tree binfo;
19891 {
19892 /* The type could not be completed. */
19895 }
19897 /* Walk in inheritance graph order. The search order is not
19898 important, and this avoids multiple walks of virtual bases. */
19900 {
19905 {
19906 /* If there is more than one satisfactory baseclass, then:
19908 [temp.deduct.call]
19910 If they yield more than one possible deduced A, the type
19911 deduction fails.
19913 applies. */
19915 {
19918 }
19921 }
19922 }
19926 }
19928 /* Returns the level of DECL, which declares a template parameter. */
19930 static int
19932 {
19934 {
19944 }
19946 }
19948 /* Decide whether ARG can be unified with PARM, considering only the
19949 cv-qualifiers of each type, given STRICT as documented for unify.
19950 Returns nonzero iff the unification is OK on that basis. */
19952 static int
19954 {
19960 {
19961 /* Although a CVR qualifier is ignored when being applied to a
19962 substituted template parameter ([8.3.2]/1 for example), that
19963 does not allow us to unify "const T" with "int&" because both
19964 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19965 It is ok when we're allowing additional CV qualifiers
19966 at the outer level [14.8.2.1]/3,1st bullet. */
19976 }
19987 }
19989 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19990 void
19992 {
19996 {
19999 }
20000 else
20001 {
20004 }
20005 }
20007 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20008 do { \
20009 if (unify (TP, TA, P, A, S, EP)) \
20010 return 1; \
20011 } while (0)
20013 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20014 expansion at the end of PACKED_PARMS. Returns 0 if the type
20015 deduction succeeds, 1 otherwise. STRICT is the same as in
20016 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20017 function call argument list. We'll need to adjust the arguments to make them
20018 types. SUBR tells us if this is from a recursive call to
20019 type_unification_real, or for comparing two template argument
20020 lists. */
20022 static int
20026 {
20027 tree parm
20037 /* Determine the parameter packs we will be deducing from the
20038 pattern, and record their current deductions. */
20041 {
20045 /* Determine the index and level of this parameter pack. */
20048 /* Keep track of the parameter packs and their corresponding
20049 argument packs. */
20052 }
20054 /* Loop through all of the arguments that have not yet been
20055 unified and unify each with the pattern. */
20057 {
20058 tree parm;
20062 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20063 or the element of its argument pack at the current index if
20064 this argument was explicitly specified. */
20066 {
20075 {
20078 }
20080 }
20082 /* If we had explicit template arguments, substitute them into the
20083 pattern before deduction. */
20085 {
20086 /* Some arguments might still be unspecified or dependent. */
20094 NULL_TREE);
20099 }
20100 else
20103 /* Unify the pattern with the current argument. */
20105 explain_p))
20108 /* For each parameter pack, collect the deduced value. */
20110 {
20116 }
20117 }
20119 /* Verify that the results of unification with the parameter packs
20120 produce results consistent with what we've seen before, and make
20121 the deduced argument packs available. */
20123 {
20130 /* By default keep the original deduced argument pack.
20131 If necessary, more specific code is going to update the
20132 resulting deduced argument later down in this function. */
20136 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20137 actually deduce anything. */
20145 {
20146 /* If we had fewer function args than explicit template args,
20147 just use the explicits. */
20152 }
20155 {
20156 tree result;
20157 /* Build the deduced *_ARGUMENT_PACK. */
20159 {
20162 }
20163 else
20168 /* Note the deduced argument packs for this parameter
20169 pack. */
20171 }
20175 {
20176 /* We only had the explicitly-provided arguments before, but
20177 now we have a complete set of arguments. */
20183 }
20184 else
20185 {
20191 /* Inconsistent unification of this parameter pack. */
20193 bad_old_arg,
20194 bad_new_arg);
20195 }
20196 }
20199 }
20201 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20202 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20203 parameters and return value are as for unify. */
20205 static int
20209 {
20210 tree parm_max;
20211 tree arg_max;
20215 /* Our representation of array types uses "N - 1" as the
20216 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20217 not an integer constant. We cannot unify arbitrarily
20218 complex expressions, so we eliminate the MINUS_EXPRs
20219 here. */
20223 {
20226 }
20230 {
20231 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20232 trying to unify the type of a variable with the type
20233 of a template parameter. For example:
20235 template <unsigned int N>
20236 void f (char (&) [N]);
20237 int g();
20238 void h(int i) {
20239 char a[g(i)];
20240 f(a);
20241 }
20243 Here, the type of the ARG will be "int [g(i)]", and
20244 may be a SAVE_EXPR, etc. */
20248 }
20250 /* If only one of the bounds used a MINUS_EXPR, compensate
20251 by adding one to the other bound. */
20254 integer_type_node,
20255 parm_max,
20256 integer_one_node);
20259 integer_type_node,
20260 arg_max,
20261 integer_one_node);
20265 }
20267 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20271 static pa_kind_t
20273 {
20282 else
20284 }
20286 /* Deduce the value of template parameters. TPARMS is the (innermost)
20287 set of template parameters to a template. TARGS is the bindings
20288 for those template parameters, as determined thus far; TARGS may
20289 include template arguments for outer levels of template parameters
20290 as well. PARM is a parameter to a template function, or a
20291 subcomponent of that parameter; ARG is the corresponding argument.
20292 This function attempts to match PARM with ARG in a manner
20293 consistent with the existing assignments in TARGS. If more values
20294 are deduced, then TARGS is updated.
20296 Returns 0 if the type deduction succeeds, 1 otherwise. The
20297 parameter STRICT is a bitwise or of the following flags:
20299 UNIFY_ALLOW_NONE:
20300 Require an exact match between PARM and ARG.
20301 UNIFY_ALLOW_MORE_CV_QUAL:
20302 Allow the deduced ARG to be more cv-qualified (by qualification
20303 conversion) than ARG.
20304 UNIFY_ALLOW_LESS_CV_QUAL:
20305 Allow the deduced ARG to be less cv-qualified than ARG.
20306 UNIFY_ALLOW_DERIVED:
20307 Allow the deduced ARG to be a template base class of ARG,
20308 or a pointer to a template base class of the type pointed to by
20309 ARG.
20310 UNIFY_ALLOW_INTEGER:
20311 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20312 case for more information.
20313 UNIFY_ALLOW_OUTER_LEVEL:
20314 This is the outermost level of a deduction. Used to determine validity
20315 of qualification conversions. A valid qualification conversion must
20316 have const qualified pointers leading up to the inner type which
20317 requires additional CV quals, except at the outer level, where const
20318 is not required [conv.qual]. It would be normal to set this flag in
20319 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20320 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20321 This is the outermost level of a deduction, and PARM can be more CV
20322 qualified at this point.
20323 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20324 This is the outermost level of a deduction, and PARM can be less CV
20325 qualified at this point. */
20327 static int
20330 {
20332 tree targ;
20333 tree tparm;
20335 tsubst_flags_t complain = (explain_p
20336 ? tf_warning_or_error
20339 /* I don't think this will do the right thing with respect to types.
20340 But the only case I've seen it in so far has been array bounds, where
20341 signedness is the only information lost, and I think that will be
20342 okay. */
20350 /* We can't deduce anything from this, but we might get all the
20351 template args from other function args. */
20357 /* If PARM uses template parameters, then we can't bail out here,
20358 even if ARG == PARM, since we won't record unifications for the
20359 template parameters. We might need them if we're trying to
20360 figure out which of two things is more specialized. */
20364 /* Handle init lists early, so the rest of the function can assume
20365 we're dealing with a type. */
20367 {
20372 /* Replace T with std::initializer_list<T> for deduction. */
20379 /* We can only deduce from an initializer list argument if the
20380 parameter is std::initializer_list or an array; otherwise this
20381 is a non-deduced context. */
20386 else
20387 {
20389 /* Deduction is defined in terms of a single type, so just punt
20390 on the (bizarre) std::initializer_list<T...>. */
20393 }
20396 {
20403 {
20407 /* It should only be possible to get here for a call. */
20409 elt_strict |= maybe_adjust_types_for_deduction
20412 }
20415 explain_p);
20416 }
20420 {
20421 /* Also deduce from the length of the initializer list. */
20428 }
20430 /* If the std::initializer_list<T> deduction worked, replace the
20431 deduced A with std::initializer_list<A>. */
20433 {
20438 }
20440 }
20442 /* If parm and arg aren't the same kind of thing (template, type, or
20443 expression), fail early. */
20447 /* Immediately reject some pairs that won't unify because of
20448 cv-qualification mismatches. */
20451 /* It is the elements of the array which hold the cv quals of an array
20452 type, and the elements might be template type parms. We'll check
20453 when we recurse. */
20455 /* We check the cv-qualifiers when unifying with template type
20456 parameters below. We want to allow ARG `const T' to unify with
20457 PARM `T' for example, when computing which of two templates
20458 is more specialized, for example. */
20472 {
20476 /* In a type which contains a nested-name-specifier, template
20477 argument values cannot be deduced for template parameters used
20478 within the nested-name-specifier. */
20490 /* The PARM is not one we're trying to unify. Just check
20491 to see if it matches ARG. */
20492 {
20497 else
20499 }
20506 /* Check for mixed types and values. */
20514 {
20517 {
20518 /* First try to match ARG directly. */
20520 explain_p);
20522 {
20523 /* Otherwise, look for a suitable base of ARG, as below. */
20530 }
20531 }
20532 /* ARG must be constructed from a template class or a template
20533 template parameter. */
20538 /* Deduce arguments T, i from TT<T> or TT<i>. */
20544 /* Fall through to deduce template name. */
20545 }
20549 {
20550 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20552 /* Simple cases: Value already set, does match or doesn't. */
20557 }
20558 else
20559 {
20560 /* If PARM is `const T' and ARG is only `int', we don't have
20561 a match unless we are allowing additional qualification.
20562 If ARG is `const int' and PARM is just `T' that's OK;
20563 that binds `const int' to `T'. */
20568 /* Consider the case where ARG is `const volatile int' and
20569 PARM is `const T'. Then, T should be `volatile int'. */
20570 arg = cp_build_qualified_type_real
20575 /* Simple cases: Value already set, does match or doesn't. */
20581 /* Make sure that ARG is not a variable-sized array. (Note
20582 that were talking about variable-sized arrays (like
20583 `int[n]'), rather than arrays of unknown size (like
20584 `int[]').) We'll get very confused by such a type since
20585 the bound of the array is not constant, and therefore
20586 not mangleable. Besides, such types are not allowed in
20587 ISO C++, so we can do as we please here. We do allow
20588 them for 'auto' deduction, since that isn't ABI-exposed. */
20592 /* Strip typedefs as in convert_template_argument. */
20594 }
20596 /* If ARG is a parameter pack or an expansion, we cannot unify
20597 against it unless PARM is also a parameter pack. */
20602 /* If the argument deduction results is a METHOD_TYPE,
20603 then there is a problem.
20604 METHOD_TYPE doesn't map to any real C++ type the result of
20605 the deduction can not be of that type. */
20619 {
20620 /* The PARM is not one we're trying to unify. Just check
20621 to see if it matches ARG. */
20627 }
20633 {
20638 }
20641 /* We deduce from array bounds in try_array_deduction. */
20645 {
20650 }
20652 /* [temp.deduct.type] If, in the declaration of a function template
20653 with a non-type template-parameter, the non-type
20654 template-parameter is used in an expression in the function
20655 parameter-list and, if the corresponding template-argument is
20656 deduced, the template-argument type shall match the type of the
20657 template-parameter exactly, except that a template-argument
20658 deduced from an array bound may be of any integral type.
20659 The non-type parameter might use already deduced type parameters. */
20662 {
20666 }
20669 /* Template-parameter dependent expression. Just accept it for now.
20670 It will later be processed in convert_template_argument. */
20671 ;
20676 /* Convert the ARG to the type of PARM; the deduced non-type
20677 template argument must exactly match the types of the
20678 corresponding parameter. */
20681 /* We haven't deduced the type of this parameter yet. Try again
20682 later. */
20684 else
20687 /* If ARG is a parameter pack or an expansion, we cannot unify
20688 against it unless PARM is also a parameter pack. */
20693 {
20696 }
20701 {
20702 /* A pointer-to-member constant can be unified only with
20703 another constant. */
20707 /* Just unify the class member. It would be useless (and possibly
20708 wrong, depending on the strict flags) to unify also
20709 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20710 arg refer to the same variable, even if through different
20711 classes. For instance:
20713 struct A { int x; };
20714 struct B : A { };
20716 Unification of &A::x and &B::x must succeed. */
20719 }
20722 {
20726 /* [temp.deduct.call]
20728 A can be another pointer or pointer to member type that can
20729 be converted to the deduced A via a qualification
20730 conversion (_conv.qual_).
20732 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20733 This will allow for additional cv-qualification of the
20734 pointed-to types if appropriate. */
20737 /* The derived-to-base conversion only persists through one
20738 level of pointers. */
20743 }
20775 /* We have already checked cv-qualification at the top of the
20776 function. */
20780 /* As far as unification is concerned, this wins. Later checks
20781 will invalidate it if necessary. */
20784 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20785 /* Type INTEGER_CST can come from ordinary constant template args. */
20797 {
20807 /* Check for pack expansions in the parameters. */
20809 {
20811 {
20813 /* We can unify against something with a trailing
20814 parameter pack. */
20816 else
20817 /* [temp.deduct.type]/9: If the template argument list of
20818 P contains a pack expansion that is not the last
20819 template argument, the entire template argument list
20820 is a non-deduced context. */
20822 }
20823 }
20825 /* If we don't have enough arguments to satisfy the parameters
20826 (not counting the pack expression at the end), or we have
20827 too many arguments for a parameter list that doesn't end in
20828 a pack expression, we can't unify. */
20834 /* Unify all of the parameters that precede the (optional)
20835 pack expression. */
20837 {
20842 }
20845 DEDUCE_EXACT,
20848 }
20856 {
20864 }
20869 {
20873 {
20874 /* First, we try to unify the PARM and ARG directly. */
20879 {
20880 /* Fallback to the special case allowed in
20881 [temp.deduct.call]:
20883 If P is a class, and P has the form
20884 template-id, then A can be a derived class of
20885 the deduced A. Likewise, if P is a pointer to
20886 a class of the form template-id, A can be a
20887 pointer to a derived class pointed to by the
20888 deduced A. */
20894 {
20895 /* Don't give the derived diagnostic if we're
20896 already dealing with the same template. */
20897 bool same_template
20903 }
20904 }
20905 }
20909 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20910 Then, we should unify `int' and `U'. */
20912 else
20913 /* There's no chance of unification succeeding. */
20918 }
20925 {
20928 tree a;
20934 /* CV qualifications for methods can never be deduced, they must
20935 match exactly. We need to check them explicitly here,
20936 because type_unification_real treats them as any other
20937 cv-qualified parameter. */
20939 && (!check_cv_quals_for_unify
20967 {
20979 }
20982 }
20985 /* Unify a pointer to member with a pointer to member function, which
20986 deduces the type of the member as a function type. */
20988 {
20989 /* Check top-level cv qualifiers */
20997 /* Determine the type of the function we are unifying against. */
21001 }
21020 /* Matched cases are handled by the ARG == PARM test above. */
21024 /* We might get a variable as a non-type template argument in parm if the
21025 corresponding parameter is type-dependent. Make any necessary
21026 adjustments based on whether arg is a reference. */
21030 {
21035 }
21036 /* Now use the normal expression code to check whether they match. */
21047 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21048 or UNDERLYING_TYPE nodes. */
21052 /* Unification fails if we hit an error node. */
21057 {
21067 }
21068 /* FALLTHRU */
21071 /* An unresolved overload is a nondeduced context. */
21075 expr:
21076 /* We must be looking at an expression. This can happen with
21077 something like:
21079 template <int I>
21080 void foo(S<I>, S<I + 2>);
21082 This is a "nondeduced context":
21084 [deduct.type]
21086 The nondeduced contexts are:
21088 --A type that is a template-id in which one or more of
21089 the template-arguments is an expression that references
21090 a template-parameter.
21092 In these cases, we assume deduction succeeded, but don't
21093 actually infer any unifications. */
21098 else
21100 }
21101 }
21102 #undef RECUR_AND_CHECK_FAILURE
21103 \f
21104 /* Note that DECL can be defined in this translation unit, if
21105 required. */
21107 static void
21109 {
21110 tree clone;
21114 }
21116 /* Called if RESULT is explicitly instantiated, or is a member of an
21117 explicitly instantiated class. */
21119 void
21121 {
21124 /* If this entity has already been written out, it's too late to
21125 make any modifications. */
21129 /* For anonymous namespace we don't need to do anything. */
21131 {
21134 }
21137 /* The TREE_PUBLIC flag for function declarations will have been
21138 set correctly by tsubst. */
21141 /* This might have been set by an earlier implicit instantiation. */
21146 else
21147 {
21150 /* Always make artificials weak. */
21153 /* For WIN32 we also want to put explicit instantiations in
21154 linkonce sections. */
21157 }
21159 /* If EXTERN_P, then this function will not be emitted -- unless
21160 followed by an explicit instantiation, at which point its linkage
21161 will be adjusted. If !EXTERN_P, then this function will be
21162 emitted here. In neither circumstance do we want
21163 import_export_decl to adjust the linkage. */
21165 }
21167 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21168 important template arguments. If any are missing, we check whether
21169 they're important by using error_mark_node for substituting into any
21170 args that were used for partial ordering (the ones between ARGS and END)
21171 and seeing if it bubbles up. */
21173 static bool
21175 {
21180 {
21183 }
21185 {
21189 }
21191 }
21193 /* Given two function templates PAT1 and PAT2, return:
21195 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21196 -1 if PAT2 is more specialized than PAT1.
21197 0 if neither is more specialized.
21199 LEN indicates the number of parameters we should consider
21200 (defaulted parameters should not be considered).
21202 The 1998 std underspecified function template partial ordering, and
21203 DR214 addresses the issue. We take pairs of arguments, one from
21204 each of the templates, and deduce them against each other. One of
21205 the templates will be more specialized if all the *other*
21206 template's arguments deduce against its arguments and at least one
21207 of its arguments *does* *not* deduce against the other template's
21208 corresponding argument. Deduction is done as for class templates.
21209 The arguments used in deduction have reference and top level cv
21210 qualifiers removed. Iff both arguments were originally reference
21211 types *and* deduction succeeds in both directions, an lvalue reference
21212 wins against an rvalue reference and otherwise the template
21213 with the more cv-qualified argument wins for that pairing (if
21214 neither is more cv-qualified, they both are equal). Unlike regular
21215 deduction, after all the arguments have been deduced in this way,
21216 we do *not* verify the deduced template argument values can be
21217 substituted into non-deduced contexts.
21219 The logic can be a bit confusing here, because we look at deduce1 and
21220 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21221 can find template arguments for pat1 to make arg1 look like arg2, that
21222 means that arg2 is at least as specialized as arg1. */
21224 int
21226 {
21239 /* Remove the this parameter from non-static member functions. If
21240 one is a non-static member function and the other is not a static
21241 member function, remove the first parameter from that function
21242 also. This situation occurs for operator functions where we
21243 locate both a member function (with this pointer) and non-member
21244 operator (with explicit first operand). */
21246 {
21251 }
21253 {
21256 {
21257 len--;
21259 }
21260 }
21262 /* If only one is a conversion operator, they are unordered. */
21266 /* Consider the return type for a conversion function */
21268 {
21271 len++;
21272 }
21274 processing_template_decl++;
21280 /* Stop when an ellipsis is seen. */
21282 {
21293 {
21294 /* When both arguments are pack expansions, we need only
21295 unify the patterns themselves. */
21299 /* This is the last comparison we need to do. */
21301 }
21303 /* DR 1847: If a particular P contains no template-parameters that
21304 participate in template argument deduction, that P is not used to
21305 determine the ordering. */
21311 {
21315 }
21318 {
21322 }
21328 {
21334 /* Setup the parameter vector, which contains only ARG1. */
21337 /* Setup the argument vector, which contains the remaining
21338 arguments. */
21347 /* We cannot deduce in the other direction, because ARG1 is
21348 a pack expansion but ARG2 is not. */
21350 }
21352 {
21358 /* Setup the parameter vector, which contains only ARG1. */
21361 /* Setup the argument vector, which contains the remaining
21362 arguments. */
21371 /* We cannot deduce in the other direction, because ARG2 is
21372 a pack expansion but ARG1 is not.*/
21374 }
21376 else
21377 {
21378 /* The normal case, where neither argument is a pack
21379 expansion. */
21386 }
21388 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21389 arg2, then arg2 is not as specialized as arg1. */
21395 /* "If, for a given type, deduction succeeds in both directions
21396 (i.e., the types are identical after the transformations above)
21397 and both P and A were reference types (before being replaced with
21398 the type referred to above):
21399 - if the type from the argument template was an lvalue reference and
21400 the type from the parameter template was not, the argument type is
21401 considered to be more specialized than the other; otherwise,
21402 - if the type from the argument template is more cv-qualified
21403 than the type from the parameter template (as described above),
21404 the argument type is considered to be more specialized than the other;
21405 otherwise,
21406 - neither type is more specialized than the other." */
21409 {
21411 {
21414 else
21416 }
21418 {
21423 }
21424 }
21427 /* We've failed to deduce something in either direction.
21428 These must be unordered. */
21431 next:
21435 /* We have already processed all of the arguments in our
21436 handing of the pack expansion type. */
21441 }
21443 /* "In most cases, all template parameters must have values in order for
21444 deduction to succeed, but for partial ordering purposes a template
21445 parameter may remain without a value provided it is not used in the
21446 types being used for partial ordering."
21448 Thus, if we are missing any of the targs1 we need to substitute into
21449 origs1, then pat2 is not as specialized as pat1. This can happen when
21450 there is a nondeduced context. */
21456 processing_template_decl--;
21458 /* If both deductions succeed, the partial ordering selects the more
21459 constrained template. */
21461 {
21466 }
21468 /* All things being equal, if the next argument is a pack expansion
21469 for one function but not for the other, prefer the
21470 non-variadic function. FIXME this is bogus; see c++/41958. */
21474 {
21477 }
21483 else
21485 }
21487 /* Determine which of two partial specializations of TMPL is more
21488 specialized.
21490 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21491 to the first partial specialization. The TREE_PURPOSE is the
21492 innermost set of template parameters for the partial
21493 specialization. PAT2 is similar, but for the second template.
21495 Return 1 if the first partial specialization is more specialized;
21496 -1 if the second is more specialized; 0 if neither is more
21497 specialized.
21499 See [temp.class.order] for information about determining which of
21500 two templates is more specialized. */
21502 static int
21504 {
21505 tree targs;
21514 /* Just like what happens for functions, if we are ordering between
21515 different template specializations, we may encounter dependent
21516 types in the arguments, and we need our dependency check functions
21517 to behave correctly. */
21521 {
21524 }
21528 {
21531 }
21534 /* If both deductions succeed, the partial ordering selects the more
21535 constrained template. */
21539 /* In the case of a tie where at least one of the templates
21540 has a parameter pack at the end, the template with the most
21541 non-packed parameters wins. */
21543 && any_deductions
21546 {
21552 /* We don't count the pack expansion at the end. */
21562 }
21565 }
21567 /* Return the template arguments that will produce the function signature
21568 DECL from the function template FN, with the explicit template
21569 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21570 also match. Return NULL_TREE if no satisfactory arguments could be
21571 found. */
21573 static tree
21575 {
21579 tree decl_arg_types;
21582 tree arg;
21586 /* Never do unification on the 'this' parameter. */
21607 }
21609 /* Return the innermost template arguments that, when applied to a partial
21610 specialization SPEC_TMPL of TMPL, yield the ARGS.
21612 For example, suppose we have:
21614 template <class T, class U> struct S {};
21615 template <class T> struct S<T*, int> {};
21617 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21618 partial specialization and the ARGS will be {double*, int}. The resulting
21619 vector will be {double}, indicating that `T' is bound to `double'. */
21621 static tree
21623 {
21625 tree spec_args
21628 tree deduced_args;
21629 tree innermost_deduced_args;
21633 {
21637 innermost_deduced_args);
21638 }
21639 else
21643 again:
21652 {
21654 {
21660 }
21662 }
21666 {
21669 }
21671 /* Verify that nondeduced template arguments agree with the type
21672 obtained from argument deduction.
21674 For example:
21676 struct A { typedef int X; };
21677 template <class T, class U> struct C {};
21678 template <class T> struct C<T, typename T::X> {};
21680 Then with the instantiation `C<A, int>', we can deduce that
21681 `T' is `A' but unify () does not check whether `typename T::X'
21682 is `int'. */
21691 /* We only need to check the innermost arguments; the other
21692 arguments will always agree. */
21697 /* Now that we have bindings for all of the template arguments,
21698 ensure that the arguments deduced for the template template
21699 parameters have compatible template parameter lists. See the use
21700 of template_template_parm_bindings_ok_p in fn_type_unification
21701 for more information. */
21706 }
21708 // Compare two function templates T1 and T2 by deducing bindings
21709 // from one against the other. If both deductions succeed, compare
21710 // constraints to see which is more constrained.
21711 static int
21713 {
21718 {
21721 }
21724 {
21727 }
21729 // If both deductions succeed, then one may be more constrained.
21734 }
21736 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21737 Return the TREE_LIST node with the most specialized template, if
21738 any. If there is no most specialized template, the error_mark_node
21739 is returned.
21741 Note that this function does not look at, or modify, the
21742 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21743 returned is one of the elements of INSTANTIATIONS, callers may
21744 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21745 and retrieve it from the value returned. */
21747 tree
21749 {
21756 {
21762 {
21763 /* Equally specialized, move to next function. If there
21764 is no next function, nothing's most specialized. */
21769 }
21770 }
21773 /* Now verify that champ is better than everything earlier in the
21774 instantiation list. */
21777 {
21780 }
21781 }
21783 processing_template_decl--;
21789 }
21791 /* If DECL is a specialization of some template, return the most
21792 general such template. Otherwise, returns NULL_TREE.
21794 For example, given:
21796 template <class T> struct S { template <class U> void f(U); };
21798 if TMPL is `template <class U> void S<int>::f(U)' this will return
21799 the full template. This function will not trace past partial
21800 specializations, however. For example, given in addition:
21802 template <class T> struct S<T*> { template <class U> void f(U); };
21804 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21805 `template <class T> template <class U> S<T*>::f(U)'. */
21807 tree
21809 {
21811 {
21814 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21815 template friend, or a FIELD_DECL for a capture pack. */
21818 }
21820 /* Look for more and more general templates. */
21822 {
21823 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21824 (See cp-tree.h for details.) */
21833 /* Stop if we run into an explicitly specialized class template. */
21840 }
21843 }
21845 /* Return the most specialized of the template partial specializations
21846 which can produce TARGET, a specialization of some class or variable
21847 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21848 a TEMPLATE_DECL node corresponding to the partial specialization, while
21849 the TREE_PURPOSE is the set of template arguments that must be
21850 substituted into the template pattern in order to generate TARGET.
21852 If the choice of partial specialization is ambiguous, a diagnostic
21853 is issued, and the error_mark_node is returned. If there are no
21854 partial specializations matching TARGET, then NULL_TREE is
21855 returned, indicating that the primary template should be used. */
21857 static tree
21859 {
21861 tree t;
21862 tree champ;
21869 {
21873 }
21875 {
21878 }
21880 {
21884 }
21885 else
21890 /* For determining which partial specialization to use, only the
21891 innermost args are interesting. */
21893 {
21896 }
21899 {
21900 tree spec_args;
21904 {
21905 /* Substitute in the template args from the enclosing class. */
21909 }
21916 {
21920 /* Keep the candidate only if the constraints are satisfied,
21921 or if we're not compiling with concepts. */
21924 {
21927 }
21928 }
21929 }
21939 {
21942 ;
21943 else
21944 {
21946 {
21949 {
21952 }
21953 }
21955 }
21956 }
21960 {
21963 {
21966 }
21967 }
21970 {
21977 else
21981 {
21986 }
21989 }
21992 }
21994 /* Explicitly instantiate DECL. */
21996 void
21998 {
22003 /* An error occurred, for which grokdeclarator has already issued
22004 an appropriate message. */
22007 {
22010 }
22016 {
22017 /* There is an asymmetry here in the way VAR_DECLs and
22018 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22019 the latter, the DECL we get back will be marked as a
22020 template instantiation, and the appropriate
22021 DECL_TEMPLATE_INFO will be set up. This does not happen for
22022 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22023 should handle VAR_DECLs as it currently handles
22024 FUNCTION_DECLs. */
22026 {
22029 }
22032 {
22035 }
22037 {
22042 }
22043 }
22045 {
22048 }
22049 else
22052 /* Check for various error cases. Note that if the explicit
22053 instantiation is valid the RESULT will currently be marked as an
22054 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22055 until we get here. */
22058 {
22059 /* DR 259 [temp.spec].
22061 Both an explicit instantiation and a declaration of an explicit
22062 specialization shall not appear in a program unless the explicit
22063 instantiation follows a declaration of the explicit specialization.
22065 For a given set of template parameters, if an explicit
22066 instantiation of a template appears after a declaration of an
22067 explicit specialization for that template, the explicit
22068 instantiation has no effect. */
22070 }
22072 {
22073 /* [temp.spec]
22075 No program shall explicitly instantiate any template more
22076 than once.
22078 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22079 the first instantiation was `extern' and the second is not,
22080 and EXTERN_P for the opposite case. */
22083 /* If an "extern" explicit instantiation follows an ordinary
22084 explicit instantiation, the template is instantiated. */
22087 }
22089 {
22092 }
22094 {
22097 }
22100 ;
22102 {
22105 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22108 }
22109 else
22117 }
22119 static void
22121 {
22127 {
22130 }
22131 }
22133 /* Called from do_type_instantiation through binding_table_foreach to
22134 do recursive instantiation for the type bound in ENTRY. */
22135 static void
22137 {
22143 }
22145 /* Called from do_type_instantiation to instantiate a member
22146 (a member function or a static member variable) of an
22147 explicitly instantiated class template. */
22148 static void
22150 {
22155 }
22157 /* Perform an explicit instantiation of template class T. STORAGE, if
22158 non-null, is the RID for extern, inline or static. COMPLAIN is
22159 nonzero if this is called from the parser, zero if called recursively,
22160 since the standard is unclear (as detailed below). */
22162 void
22164 {
22174 {
22175 tree tmpl =
22179 else
22182 }
22187 {
22190 t);
22192 }
22195 {
22197 {
22199 {
22202 "ISO C++ 1998 forbids the use of %<extern%> on "
22204 }
22205 else
22207 "ISO C++ forbids the use of %qE"
22209 }
22217 else
22218 {
22220 storage);
22222 }
22223 }
22226 {
22227 /* DR 259 [temp.spec].
22229 Both an explicit instantiation and a declaration of an explicit
22230 specialization shall not appear in a program unless the explicit
22231 instantiation follows a declaration of the explicit specialization.
22233 For a given set of template parameters, if an explicit
22234 instantiation of a template appears after a declaration of an
22235 explicit specialization for that template, the explicit
22236 instantiation has no effect. */
22238 }
22240 {
22241 /* [temp.spec]
22243 No program shall explicitly instantiate any template more
22244 than once.
22246 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22247 instantiation was `extern'. If EXTERN_P then the second is.
22248 These cases are OK. */
22255 /* If we've already instantiated the template, just return now. */
22258 }
22266 {
22267 tree tmp;
22269 /* In contrast to implicit instantiation, where only the
22270 declarations, and not the definitions, of members are
22271 instantiated, we have here:
22273 [temp.explicit]
22275 The explicit instantiation of a class template specialization
22276 implies the instantiation of all of its members not
22277 previously explicitly specialized in the translation unit
22278 containing the explicit instantiation.
22280 Of course, we can't instantiate member template classes, since
22281 we don't have any arguments for them. Note that the standard
22282 is unclear on whether the instantiation of the members are
22283 *explicit* instantiations or not. However, the most natural
22284 interpretation is that it should be an explicit instantiation. */
22300 }
22301 }
22303 /* Given a function DECL, which is a specialization of TMPL, modify
22304 DECL to be a re-instantiation of TMPL with the same template
22305 arguments. TMPL should be the template into which tsubst'ing
22306 should occur for DECL, not the most general template.
22308 One reason for doing this is a scenario like this:
22310 template <class T>
22311 void f(const T&, int i);
22313 void g() { f(3, 7); }
22315 template <class T>
22316 void f(const T& t, const int i) { }
22318 Note that when the template is first instantiated, with
22319 instantiate_template, the resulting DECL will have no name for the
22320 first parameter, and the wrong type for the second. So, when we go
22321 to instantiate the DECL, we regenerate it. */
22323 static void
22325 {
22326 /* The arguments used to instantiate DECL, from the most general
22327 template. */
22328 tree code_pattern;
22332 /* Make sure that we can see identifiers, and compute access
22333 correctly. */
22337 {
22338 tree decl_parm;
22339 tree pattern_parm;
22340 tree specs;
22354 specs);
22356 /* Merge parameter declarations. */
22359 pattern_parm
22363 {
22364 tree parm_type;
22365 tree attributes;
22370 NULL_TREE);
22376 {
22379 }
22382 }
22383 /* Merge any parameters that match with the function parameter
22384 pack. */
22386 {
22388 tree expanded_types;
22389 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22390 the parameters in this function parameter pack. */
22395 {
22396 tree parm_type;
22397 tree attributes;
22400 /* Rename the parameter to include the index. */
22409 {
22412 }
22414 }
22415 }
22416 /* Merge additional specifiers from the CODE_PATTERN. */
22420 }
22422 {
22430 }
22431 else
22435 }
22437 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22438 substituted to get DECL. */
22440 tree
22442 {
22445 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22446 for the instantiation. This is not always the most general
22447 template. Consider, for example:
22449 template <class T>
22450 struct S { template <class U> void f();
22451 template <> void f<int>(); };
22453 and an instantiation of S<double>::f<int>. We want TD to be the
22454 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22456 more general template. */
22458 /* We must also deal with friend templates. Given:
22460 template <class T> struct S {
22461 template <class U> friend void f() {};
22462 };
22464 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22465 so far as the language is concerned, but that's still
22466 where we get the pattern for the instantiation from. On
22467 other hand, if the definition comes outside the class, say:
22469 template <class T> struct S {
22470 template <class U> friend void f();
22471 };
22472 template <class U> friend void f() {}
22474 we don't need to look any further. That's what the check for
22475 DECL_INITIAL is for. */
22479 {
22480 /* The present template, TD, should not be a definition. If it
22481 were a definition, we should be using it! Note that we
22482 cannot restructure the loop to just keep going until we find
22483 a template with a definition, since that might go too far if
22484 a specialization was declared, but not defined. */
22486 /* Fetch the more general template. */
22488 }
22491 }
22493 /* Returns true if we need to instantiate this template instance even if we
22494 know we aren't going to emit it. */
22496 bool
22498 {
22499 /* We always instantiate inline functions so that we can inline them. An
22500 explicit instantiation declaration prohibits implicit instantiation of
22501 non-inline functions. With high levels of optimization, we would
22502 normally inline non-inline functions -- but we're not allowed to do
22503 that for "extern template" functions. Therefore, we check
22504 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22508 /* And we need to instantiate static data members so that
22509 their initializers are available in integral constant
22510 expressions. */
22513 }
22515 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22516 instantiate it now, modifying TREE_TYPE (fn). */
22518 void
22520 {
22523 /* Don't instantiate a noexcept-specification from template context. */
22538 {
22542 {
22557 }
22558 else
22562 }
22565 {
22568 else
22570 }
22571 }
22573 /* Produce the definition of D, a _DECL generated from a template. If
22574 DEFER_OK is true, then we don't have to actually do the
22575 instantiation now; we just have to do it sometime. Normally it is
22576 an error if this is an explicit instantiation but D is undefined.
22577 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22578 instantiated class template. */
22580 tree
22582 {
22584 tree gen_args;
22585 tree args;
22586 tree td;
22587 tree code_pattern;
22588 tree spec;
22589 tree gen_tmpl;
22597 /* This function should only be used to instantiate templates for
22598 functions and static member variables. */
22601 /* A concept is never instantiated. */
22604 /* Variables are never deferred; if instantiation is required, they
22605 are instantiated right away. That allows for better code in the
22606 case that an expression refers to the value of the variable --
22607 if the variable has a constant value the referring expression can
22608 take advantage of that fact. */
22612 /* Don't instantiate cloned functions. Instead, instantiate the
22613 functions they cloned. */
22621 /* D has already been instantiated or explicitly specialized, so
22622 there's nothing for us to do here.
22624 It might seem reasonable to check whether or not D is an explicit
22625 instantiation, and, if so, stop here. But when an explicit
22626 instantiation is deferred until the end of the compilation,
22627 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22628 the instantiation. */
22631 /* Check to see whether we know that this template will be
22632 instantiated in some other file, as with "extern template"
22633 extension. */
22636 /* In general, we do not instantiate such templates. */
22644 /* We should already have the extra args. */
22647 /* And what's in the hash table should match D. */
22651 /* This needs to happen before any tsubsting. */
22657 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22658 for the instantiation. */
22663 {
22664 /* Look up an explicit specialization, if any. */
22668 {
22671 }
22672 }
22676 /* We should never be trying to instantiate a member of a class
22677 template or partial specialization. */
22682 /* In the case of a friend template whose definition is provided
22683 outside the class, we may have too many arguments. Drop the
22684 ones we don't need. The same is true for specializations. */
22685 args = get_innermost_template_args
22689 {
22695 }
22696 else
22697 {
22702 else
22704 }
22706 /* We may be in the middle of deferred access check. Disable it now. */
22709 /* Unless an explicit instantiation directive has already determined
22710 the linkage of D, remember that a definition is available for
22711 this entity. */
22721 /* If D is a member of an explicitly instantiated class template,
22722 and no definition is available, treat it like an implicit
22723 instantiation. */
22726 {
22727 /* Leave linkage flags alone on instantiations with anonymous
22728 visibility. */
22730 {
22733 }
22735 }
22737 /* Defer all other templates, unless we have been explicitly
22738 forbidden from doing so. */
22740 template. */
22741 ! pattern_defined
22742 /* If it's OK to postpone instantiation, do so. */
22743 || defer_ok
22744 /* If this is a static data member that will be defined
22745 elsewhere, we don't want to instantiate the entire data
22746 member, but we do want to instantiate the initializer so that
22747 we can substitute that elsewhere. */
22749 /* Handle here a deleted function too, avoid generating
22750 its body (c++/61080). */
22752 {
22753 /* The definition of the static data member is now required so
22754 we must substitute the initializer. */
22758 {
22759 tree ns;
22760 tree init;
22769 args,
22772 /* If instantiating the initializer involved instantiating this
22773 again, don't call cp_finish_decl twice. */
22775 {
22776 /* Make sure the initializer is still constant, in case of
22777 circular dependency (template/instantiate6.C). */
22778 const_init
22782 LOOKUP_ONLYCONVERTING);
22783 }
22787 }
22789 /* We restore the source position here because it's used by
22790 add_pending_template. */
22796 /* [temp.explicit]
22798 The definition of a non-exported function template, a
22799 non-exported member function template, or a non-exported
22800 member function or static data member of a class template
22801 shall be present in every translation unit in which it is
22802 explicitly instantiated. */
22806 /* If we're in unevaluated context, we just wanted to get the
22807 constant value; this isn't an odr use, so don't queue
22808 a full instantiation. */
22811 /* ??? Historically, we have instantiated inline functions, even
22812 when marked as "extern template". */
22816 }
22817 /* Tell the repository that D is available in this translation unit
22818 -- and see if it is supposed to be instantiated here. */
22820 {
22821 /* In a PCH file, despite the fact that the repository hasn't
22822 requested instantiation in the PCH it is still possible that
22823 an instantiation will be required in a file that includes the
22824 PCH. */
22827 /* Instantiate inline functions so that the inliner can do its
22828 job, even though we'll not be emitting a copy of this
22829 function. */
22832 }
22835 tree fn_context;
22846 else
22847 {
22851 }
22853 /* Mark D as instantiated so that recursive calls to
22854 instantiate_decl do not try to instantiate it again. */
22857 /* Regenerate the declaration in case the template has been modified
22858 by a subsequent redeclaration. */
22861 /* We already set the file and line above. Reset them now in case
22862 they changed as a result of calling regenerate_decl_from_template. */
22866 {
22867 tree init;
22870 /* Clear out DECL_RTL; whatever was there before may not be right
22871 since we've reset the type of the declaration. */
22875 /* The initializer is placed in DECL_INITIAL by
22876 regenerate_decl_from_template so we don't need to
22877 push/pop_access_scope again here. Pull it out so that
22878 cp_finish_decl can process it. */
22883 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22884 initializer. That function will defer actual emission until
22885 we have a chance to determine linkage. */
22888 /* Enter the scope of D so that access-checking works correctly. */
22901 }
22905 {
22907 tree tmpl_parm;
22908 tree spec_parm;
22912 /* Save away the current list, in case we are instantiating one
22913 template from within the body of another. */
22916 /* Set up the list of local specializations. */
22919 /* Set up context. */
22923 else
22924 {
22926 {
22927 /* When instantiating a lambda's templated function
22928 operator, we need to push the non-lambda class scope
22929 of the lambda itself so that the nested function
22930 stack is sufficiently correct to deal with this
22931 capture. */
22933 do
22938 }
22940 }
22942 /* Some typedefs referenced from within the template code need to be
22943 access checked at template instantiation time, i.e now. These
22944 types were added to the template at parsing time. Let's get those
22945 and perform the access checks then. */
22947 args);
22949 /* Create substitution entries for the parameters. */
22953 {
22957 }
22959 {
22961 {
22964 }
22965 else
22966 {
22967 /* Register the (value) argument pack as a specialization of
22968 TMPL_PARM, then move on. */
22971 }
22972 }
22975 /* Substitute into the body of the function. */
22979 else
22980 {
22985 /* Set the current input_location to the end of the function
22986 so that finish_function knows where we are. */
22987 input_location
22990 /* Remember if we saw an infinite loop in the template. */
22991 current_function_infinite_loop
22993 }
22995 /* We don't need the local specializations any more. */
22999 /* Finish the function. */
23003 else
23004 {
23007 }
23013 }
23015 /* We're not deferring instantiation any more. */
23020 else
23026 out:
23035 }
23037 /* Run through the list of templates that we wish we could
23038 instantiate, and instantiate any we can. RETRIES is the
23039 number of times we retry pending template instantiation. */
23041 void
23043 {
23047 /* Instantiating templates may trigger vtable generation. This in turn
23048 may require further template instantiations. We place a limit here
23049 to avoid infinite loop. */
23051 {
23055 "template instantiation depth exceeds maximum of %d"
23056 " instantiating %q+D, possibly from virtual table generation"
23060 /* Pretend that we defined it. */
23063 }
23065 do
23066 {
23071 {
23076 {
23077 tree fn;
23080 {
23084 fn;
23092 }
23095 }
23096 else
23097 {
23100 {
23101 instantiation
23107 }
23111 }
23114 /* If INSTANTIATION has been instantiated, then we don't
23115 need to consider it again in the future. */
23117 else
23118 {
23121 }
23124 }
23126 }
23130 }
23132 /* Substitute ARGVEC into T, which is a list of initializers for
23133 either base class or a non-static data member. The TREE_PURPOSEs
23134 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23135 instantiate_decl. */
23137 static tree
23139 {
23143 {
23144 tree decl;
23145 tree init;
23151 {
23152 tree expr;
23153 tree arg;
23155 /* Expand the base class expansion type into separate base
23156 classes. */
23158 tf_warning_or_error,
23159 NULL_TREE);
23163 /* We'll be building separate TREE_LISTs of arguments for
23164 each base. */
23170 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23171 expand each argument in the TREE_VALUE of t. */
23178 /* VOID_TYPE_NODE is used to indicate
23179 value-initialization. */
23180 {
23183 }
23184 else
23185 {
23186 /* Substitute parameter packs into each argument in the
23187 TREE_LIST. */
23190 {
23191 tree expanded_exprs;
23193 /* Expand the argument. */
23195 expanded_exprs
23197 tf_warning_or_error,
23198 NULL_TREE);
23202 /* Prepend each of the expanded expressions to the
23203 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23205 {
23210 }
23211 }
23214 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23215 since we built them backwards. */
23217 {
23220 }
23221 }
23222 }
23225 {
23227 {
23231 }
23232 else
23233 {
23234 tree tmp;
23249 /* If we had an initializer but it instantiated to nothing,
23250 value-initialize the object. This will only occur when
23251 the initializer was a pack expansion where the parameter
23252 packs used in that expansion were of length zero. */
23255 }
23258 {
23262 }
23263 }
23264 }
23266 }
23268 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23270 static void
23272 {
23277 else
23279 }
23281 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23282 is the instantiation (which should have been created with
23283 start_enum) and ARGS are the template arguments to use. */
23285 static void
23287 {
23288 tree e;
23294 {
23295 tree value;
23296 tree decl;
23299 /* Note that in a template enum, the TREE_VALUE is the
23300 CONST_DECL, not the corresponding INTEGER_CST. */
23305 /* Give this enumeration constant the correct access. */
23308 /* Actually build the enumerator itself. Here we're assuming that
23309 enumerators can't have dependent attributes. */
23312 }
23322 }
23324 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23325 its type -- but without substituting the innermost set of template
23326 arguments. So, innermost set of template parameters will appear in
23327 the type. */
23329 tree
23331 {
23332 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23334 }
23336 /* Return truthvalue if we're processing a template different from
23337 the last one involved in diagnostics. */
23338 bool
23340 {
23342 }
23344 /* Remember current template involved in diagnostics. */
23345 void
23347 {
23349 }
23353 {
23355 }
23357 /* Return TRUE if current_function_decl is being instantiated, false
23358 otherwise. */
23360 bool
23362 {
23365 }
23367 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23368 type. Return zero for ok, nonzero for disallowed. Issue error and
23369 warning messages under control of COMPLAIN. */
23371 static int
23373 {
23388 /* A bound template template parm could later be instantiated to have a valid
23389 nontype parm type via an alias template. */
23395 {
23398 else
23400 type);
23401 }
23403 }
23405 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23406 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23408 static bool
23410 {
23411 tree scope;
23413 /* [temp.dep.type]
23415 A type is dependent if it is:
23417 -- a template parameter. Template template parameters are types
23418 for us (since TYPE_P holds true for them) so we handle
23419 them here. */
23423 /* -- a qualified-id with a nested-name-specifier which contains a
23424 class-name that names a dependent type or whose unqualified-id
23425 names a dependent type. */
23429 /* An alias template specialization can be dependent even if the
23430 resulting type is not. */
23434 /* -- a cv-qualified type where the cv-unqualified type is
23435 dependent.
23436 No code is necessary for this bullet; the code below handles
23437 cv-qualified types, and we don't want to strip aliases with
23438 TYPE_MAIN_VARIANT because of DR 1558. */
23439 /* -- a compound type constructed from any dependent type. */
23449 {
23450 tree arg_type;
23455 arg_type;
23460 {
23461 /* A value-dependent noexcept-specifier makes the type dependent. */
23466 }
23468 }
23469 /* -- an array type constructed from any dependent type or whose
23470 size is specified by a constant expression that is
23471 value-dependent.
23473 We checked for type- and value-dependence of the bounds in
23474 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23476 {
23481 }
23483 /* -- a template-id in which either the template name is a template
23484 parameter ... */
23487 /* ... or any of the template arguments is a dependent type or
23488 an expression that is type-dependent or value-dependent. */
23490 && (any_dependent_template_arguments_p
23494 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23495 dependent; if the argument of the `typeof' expression is not
23496 type-dependent, then it should already been have resolved. */
23502 /* A template argument pack is dependent if any of its packed
23503 arguments are. */
23505 {
23511 }
23513 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23514 be template parameters. */
23521 /* The standard does not specifically mention types that are local
23522 to template functions or local classes, but they should be
23523 considered dependent too. For example:
23525 template <int I> void f() {
23526 enum E { a = I };
23527 S<sizeof (E)> s;
23528 }
23530 The size of `E' cannot be known until the value of `I' has been
23531 determined. Therefore, `E' must be considered dependent. */
23535 /* Don't use type_dependent_expression_p here, as it can lead
23536 to infinite recursion trying to determine whether a lambda
23537 nested in a lambda is dependent (c++/47687). */
23541 && (any_dependent_template_arguments_p
23545 /* Other types are non-dependent. */
23547 }
23549 /* Returns TRUE if TYPE is dependent, in the sense of
23550 [temp.dep.type]. Note that a NULL type is considered dependent. */
23552 bool
23554 {
23555 /* If there are no template parameters in scope, then there can't be
23556 any dependent types. */
23558 {
23559 /* If we are not processing a template, then nobody should be
23560 providing us with a dependent type. */
23564 }
23566 /* If the type is NULL, we have not computed a type for the entity
23567 in question; in that case, the type is dependent. */
23571 /* Erroneous types can be considered non-dependent. */
23575 /* Getting here with global_type_node means we improperly called this
23576 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23579 /* If we have not already computed the appropriate value for TYPE,
23580 do so now. */
23582 {
23585 }
23588 }
23590 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23591 lookup. In other words, a dependent type that is not the current
23592 instantiation. */
23594 bool
23596 {
23599 }
23601 /* T is a SCOPE_REF; return whether we need to consider it
23602 instantiation-dependent so that we can check access at instantiation
23603 time even though we know which member it resolves to. */
23605 static bool
23607 {
23613 else
23615 }
23617 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23618 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23619 expression. */
23621 /* Note that this predicate is not appropriate for general expressions;
23622 only constant expressions (that satisfy potential_constant_expression)
23623 can be tested for value dependence. */
23625 bool
23627 {
23631 /* A name declared with a dependent type. */
23636 {
23638 /* A dependent member function of the current instantiation. */
23642 /* A dependent member function of the current instantiation. */
23649 /* A name that has not been looked up -- must be dependent. */
23653 /* A non-type template parm. */
23657 /* A non-type template parm. */
23663 /* A constant with literal type and is initialized
23664 with an expression that is value-dependent.
23666 Note that a non-dependent parenthesized initializer will have
23667 already been replaced with its constant value, so if we see
23668 a TREE_LIST it must be dependent. */
23672 /* cp_finish_decl doesn't fold reference initializers. */
23678 {
23682 }
23690 /* These expressions are value-dependent if the type to which
23691 the cast occurs is dependent or the expression being casted
23692 is value-dependent. */
23693 {
23699 /* A functional cast has a list of operands. */
23702 {
23703 /* If there are no operands, it must be an expression such
23704 as "int()". This should not happen for aggregate types
23705 because it would form non-constant expressions. */
23710 }
23716 }
23721 /* FALLTHRU */
23724 /* A `sizeof' expression is value-dependent if the operand is
23725 type-dependent or is a pack expansion. */
23734 /* An 'encode' expression is value-dependent if the operand is
23735 type-dependent. */
23744 /* All instantiation-dependent expressions should also be considered
23745 value-dependent. */
23753 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23754 is value-dependent. */
23755 {
23764 }
23767 {
23771 }
23782 {
23786 }
23789 /* Treat all requires-expressions as value-dependent so
23790 we don't try to fold them. */
23797 {
23804 {
23806 /* In a call to a constexpr member function, look through the
23807 implicit ADDR_EXPR on the object argument so that it doesn't
23808 cause the call to be considered value-dependent. We also
23809 look through it in potential_constant_expression. */
23816 }
23818 }
23821 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23822 type-dependent. */
23827 {
23829 tree val;
23836 }
23839 /* Treat a GNU statement expression as dependent to avoid crashing
23840 under instantiate_non_dependent_expr; it can't be constant. */
23844 /* A constant expression is value-dependent if any subexpression is
23845 value-dependent. */
23847 {
23854 {
23858 {
23861 /* In some cases, some of the operands may be missing.l
23862 (For example, in the case of PREDECREMENT_EXPR, the
23863 amount to increment by may be missing.) That doesn't
23864 make the expression dependent. */
23867 }
23868 }
23872 }
23874 }
23876 /* The expression is not value-dependent. */
23878 }
23880 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23881 [temp.dep.expr]. Note that an expression with no type is
23882 considered dependent. Other parts of the compiler arrange for an
23883 expression with type-dependent subexpressions to have no type, so
23884 this function doesn't have to be fully recursive. */
23886 bool
23888 {
23895 /* An unresolved name is always dependent. */
23901 /* A fold expression is type-dependent. */
23908 /* Some expression forms are never type-dependent. */
23922 /* The types of these expressions depends only on the type to which
23923 the cast occurs. */
23932 /* The types of these expressions depends only on the type created
23933 by the expression. */
23936 {
23937 /* For NEW_EXPR tree nodes created inside a template, either
23938 the object type itself or a TREE_LIST may appear as the
23939 operand 1. */
23942 /* This is an array type. We need to check array dimensions
23943 as well. */
23945 || value_dependent_expression_p
23947 else
23949 }
23952 {
23956 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23957 contains an identifier associated by name lookup with one or more
23958 declarations declared with a dependent type, or...a
23959 nested-name-specifier or qualified-id that names a member of an
23960 unknown specialization. */
23963 }
23973 {
23974 tree elt;
23978 {
23981 }
23983 }
23985 /* A static data member of the current instantiation with incomplete
23986 array type is type-dependent, as the definition and specializations
23987 can have different bounds. */
23994 /* An array of unknown bound depending on a variadic parameter, eg:
23996 template<typename... Args>
23997 void foo (Args... args)
23998 {
23999 int arr[] = { args... };
24000 }
24002 template<int... vals>
24003 void bar ()
24004 {
24005 int arr[] = { vals... };
24006 }
24008 If the array has no length and has an initializer, it must be that
24009 we couldn't determine its length in cp_complete_array_type because
24010 it is dependent. */
24018 /* A function or variable template-id is type-dependent if it has any
24019 dependent template arguments. Note that we only consider the innermost
24020 template arguments here, since those are the ones that come from the
24021 template-id; the template arguments for the enclosing class do not make it
24022 type-dependent, they only make a member function value-dependent. */
24027 && (any_dependent_template_arguments_p
24031 /* Always dependent, on the number of arguments if nothing else. */
24036 {
24041 {
24047 }
24048 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24053 {
24058 }
24061 {
24068 }
24078 }
24082 /* Dependent type attributes might not have made it from the decl to
24083 the type yet. */
24089 }
24091 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24092 type-dependent if the expression refers to a member of the current
24093 instantiation and the type of the referenced member is dependent, or the
24094 class member access expression refers to a member of an unknown
24095 specialization.
24097 This function returns true if the OBJECT in such a class member access
24098 expression is of an unknown specialization. */
24100 bool
24102 {
24103 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24104 dependent. */
24109 }
24111 /* walk_tree callback function for instantiation_dependent_expression_p,
24112 below. Returns non-zero if a dependent subexpression is found. */
24114 static tree
24117 {
24119 {
24120 /* We don't have to worry about decltype currently because decltype
24121 of an instantiation-dependent expr is a dependent type. This
24122 might change depending on the resolution of DR 1172. */
24125 }
24128 {
24129 /* Don't treat an argument list as dependent just because it has no
24130 TREE_TYPE. */
24138 /* Handle expressions with type operands. */
24143 {
24148 {
24151 else
24152 {
24155 }
24156 }
24158 }
24162 /* In a template, finish_class_member_access_expr creates a
24163 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24164 type-dependent, so that we can check access control at
24165 instantiation time (PR 42277). See also Core issue 1273. */
24172 else
24175 /* Treat statement-expressions as dependent. */
24179 /* Treat requires-expressions as dependent. */
24184 /* Treat calls to function concepts as dependent. */
24190 /* And variable concepts. */
24197 }
24201 else
24203 }
24205 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24206 sense defined by the ABI:
24208 "An expression is instantiation-dependent if it is type-dependent
24209 or value-dependent, or it has a subexpression that is type-dependent
24210 or value-dependent."
24212 Except don't actually check value-dependence for unevaluated expressions,
24213 because in sizeof(i) we don't care about the value of i. Checking
24214 type-dependence will in turn check value-dependence of array bounds/template
24215 arguments as needed. */
24217 bool
24219 {
24220 tree result;
24231 }
24233 /* As above, but also check value-dependence of the expression as a whole. */
24235 bool
24237 {
24240 }
24242 /* Like type_dependent_expression_p, but it also works while not processing
24243 a template definition, i.e. during substitution or mangling. */
24245 bool
24247 {
24253 }
24255 /* Returns TRUE if ARGS contains a type-dependent expression. */
24257 bool
24259 {
24261 tree arg;
24264 {
24267 }
24269 }
24271 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24272 expressions) contains any type-dependent expressions. */
24274 bool
24276 {
24282 }
24284 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24285 expressions) contains any value-dependent expressions. */
24287 bool
24289 {
24295 }
24297 /* Returns TRUE if the ARG (a template argument) is dependent. */
24299 bool
24301 {
24305 /* Assume a template argument that was wrongly written by the user
24306 is dependent. This is consistent with what
24307 any_dependent_template_arguments_p [that calls this function]
24308 does. */
24318 {
24321 /* A member template of a dependent class is not necessarily
24322 type-dependent, but it is a dependent template argument because it
24323 will be a member of an unknown specialization to that template. */
24326 }
24328 {
24332 {
24335 }
24338 }
24341 else
24344 }
24346 /* Returns true if ARGS (a collection of template arguments) contains
24347 any types that require structural equality testing. */
24349 bool
24351 {
24361 {
24364 {
24370 {
24371 /* Look inside the argument pack. */
24374 }
24377 {
24390 }
24391 }
24392 }
24395 }
24397 /* Returns true if ARGS (a collection of template arguments) contains
24398 any dependent arguments. */
24400 bool
24402 {
24412 {
24417 }
24420 }
24422 /* Returns TRUE if the template TMPL is type-dependent. */
24424 bool
24426 {
24428 {
24433 }
24435 /* Template template parameters are dependent. */
24439 /* So are names that have not been looked up. */
24443 }
24445 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24447 bool
24449 {
24452 }
24454 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24455 are dependent. */
24457 bool
24459 {
24466 {
24488 {
24492 }
24496 {
24500 {
24505 }
24506 }
24507 }
24510 }
24512 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24513 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24514 no such TYPE can be found. Note that this function peers inside
24515 uninstantiated templates and therefore should be used only in
24516 extremely limited situations. ONLY_CURRENT_P restricts this
24517 peering to the currently open classes hierarchy (which is required
24518 when comparing types). */
24520 tree
24522 {
24523 tree scope;
24524 tree name;
24525 tree decl;
24527 tree pushed_scope;
24528 tree result;
24533 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24534 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24535 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24536 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24537 identifier of the TYPENAME_TYPE anymore.
24538 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24539 TYPENAME_TYPE instead, we avoid messing up with a possible
24540 typedef variant case. */
24543 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24544 it first before we can figure out what NAME refers to. */
24546 {
24548 /* Given a class template A with a dependent base with nested type C,
24549 typedef typename A::C::C C will land us here, as trying to resolve
24550 the initial A::C leads to the local C typedef, which leads back to
24551 A::C::C. So we break the recursion now. */
24553 else
24555 }
24556 /* If we don't know what SCOPE refers to, then we cannot resolve the
24557 TYPENAME_TYPE. */
24560 /* If this is a typedef, we don't want to look inside (c++/11987). */
24563 /* If SCOPE isn't the template itself, it will not have a valid
24564 TYPE_FIELDS list. */
24566 /* scope is either the template itself or a compatible instantiation
24567 like X<T>, so look up the name in the original template. */
24569 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24571 /* If scope has no fields, it can't be a current instantiation. Check this
24572 before currently_open_class to avoid infinite recursion (71515). */
24575 /* If the SCOPE is not the current instantiation, there's no reason
24576 to look inside it. */
24579 /* Enter the SCOPE so that name lookup will be resolved as if we
24580 were in the class definition. In particular, SCOPE will no
24581 longer be considered a dependent type. */
24583 /* Look up the declaration. */
24585 tf_warning_or_error);
24589 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24590 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24595 {
24599 }
24602 {
24603 tree tmpl;
24604 tree args;
24605 /* Obtain the template and the arguments. */
24608 /* Instantiate the template. */
24614 }
24616 /* Leave the SCOPE. */
24620 /* If we failed to resolve it, return the original typename. */
24624 /* If lookup found a typename type, resolve that too. */
24626 {
24627 /* Ill-formed programs can cause infinite recursion here, so we
24628 must catch that. */
24632 }
24634 /* Qualify the resulting type. */
24640 }
24642 /* EXPR is an expression which is not type-dependent. Return a proxy
24643 for EXPR that can be used to compute the types of larger
24644 expressions containing EXPR. */
24646 tree
24648 {
24649 tree inner_expr;
24651 /* When checking, try to get a constant value for all non-dependent
24652 expressions in order to expose bugs in *_dependent_expression_p
24653 and constexpr. This can affect code generation, see PR70704, so
24654 only do this for -fchecking=2. */
24657 /* Don't do this during nsdmi parsing as it can lead to
24658 unexpected recursive instantiations. */
24660 /* Don't do this during concept expansion either and for
24661 the same reason. */
24665 /* Preserve OVERLOADs; the functions must be available to resolve
24666 types. */
24677 /* There is no need to return a proxy for a variable. */
24680 /* Preserve string constants; conversions from string constants to
24681 "char *" are allowed, even though normally a "const char *"
24682 cannot be used to initialize a "char *". */
24685 /* Preserve void and arithmetic constants, as an optimization -- there is no
24686 reason to create a new node. */
24691 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24692 There is at least one place where we want to know that a
24693 particular expression is a throw-expression: when checking a ?:
24694 expression, there are special rules if the second or third
24695 argument is a throw-expression. */
24699 /* Don't wrap an initializer list, we need to be able to look inside. */
24703 /* Don't wrap a dummy object, we need to be able to test for it. */
24722 /* If the type is unknown, it can't really be non-dependent */
24725 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24727 }
24729 /* ARGS is a vector of expressions as arguments to a function call.
24730 Replace the arguments with equivalent non-dependent expressions.
24731 This modifies ARGS in place. */
24733 void
24735 {
24737 tree arg;
24740 {
24744 }
24745 }
24747 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24748 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24749 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24751 static tree
24753 {
24767 }
24769 tree
24771 {
24773 }
24775 tree
24777 {
24779 }
24781 /* Return a C++17 deduction placeholder for class template TMPL. */
24783 tree
24785 {
24789 }
24791 /* Make a "constrained auto" type-specifier. This is an
24792 auto type with constraints that must be associated after
24793 deduction. The constraint is formed from the given
24794 CONC and its optional sequence of arguments, which are
24795 non-null if written as partial-concept-id. */
24797 tree
24799 {
24802 /* Build the constraint. */
24810 /* Our canonical type depends on the constraint. */
24813 /* Attach the constraint to the type declaration. */
24816 }
24818 /* Given type ARG, return std::initializer_list<ARG>. */
24820 static tree
24822 {
24826 {
24830 }
24836 }
24838 /* Replace auto in TYPE with std::initializer_list<auto>. */
24840 static tree
24842 {
24849 }
24851 /* Hash traits for hashing possibly constrained 'auto'
24852 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24855 {
24858 };
24860 /* Hash the 'auto' T. */
24862 inline hashval_t
24864 {
24866 /* Matching constrained-type-specifiers denote the same template
24867 parameter, so hash the constraint. */
24869 else
24870 /* But unconstrained autos are all separate, so just hash the pointer. */
24872 }
24874 /* Compare two 'auto's. */
24878 {
24885 /* Two unconstrained autos are distinct. */
24890 }
24892 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24893 constrained) auto, add it to the vector. */
24895 static int
24897 {
24900 {
24901 /* All the autos were built with index 0; fix that up now. */
24905 /* If this is a repeated constrained-type-specifier, use the index we
24906 chose before. */
24908 else
24909 {
24910 /* Otherwise this is new, so use the current count. */
24913 }
24915 }
24917 /* Always keep walking. */
24919 }
24921 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24922 says they can appear anywhere in the type. */
24924 static tree
24926 {
24935 {
24940 }
24943 }
24945 /* The stem for deduction guide names. */
24948 /* Return the name for a deduction guide for class template TMPL. */
24950 tree
24952 {
24963 }
24965 /* True if NAME is the name of a deduction guide. */
24967 bool
24969 {
24973 }
24975 /* True if FN is a deduction guide. */
24977 bool
24979 {
24984 }
24986 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24988 bool
24990 {
24997 }
24999 /* True if FN is a guide generated from a constructor template. */
25001 bool
25003 {
25008 {
25011 }
25013 }
25015 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25016 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25017 template parameter types. Note that the handling of template template
25018 parameters relies on current_template_parms being set appropriately for the
25019 new template. */
25021 static tree
25024 {
25027 tree newtype;
25030 {
25037 }
25038 else
25042 tree newdecl
25047 tree newidx;
25050 {
25060 {
25065 // First create a copy (ttargs) of tsubst_args with an
25066 // additional level for the template template parameter's own
25067 // template parameters (ttparms).
25068 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25076 // Substitute ttargs into ttparms to fix references to
25077 // other template parameters.
25079 complain);
25080 // Now substitute again with args based on tparms, to reduce
25081 // the level of the ttparms.
25084 complain);
25085 // Finally, tack the adjusted parms onto tparms.
25087 current_template_parms);
25089 }
25090 }
25091 else
25092 {
25094 tree newconst
25106 }
25109 }
25111 /* Returns a C++17 class deduction guide template based on the constructor
25112 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25113 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25115 static tree
25117 {
25121 location_t loc;
25124 {
25128 {
25131 }
25132 else
25142 }
25143 else
25144 {
25148 tree fn_tmpl;
25150 {
25153 }
25154 else
25158 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25159 fully specialized args for the enclosing class. Strip those off, as
25160 the deduction guide won't have those template parameters. */
25163 /* Discard the 'this' parameter. */
25171 {
25174 /* For a member template constructor, we need to flatten the two
25175 template parameter lists into one, and then adjust the function
25176 signature accordingly. This gets...complicated. */
25180 /* For a member template we should have two levels of parms/args, one
25181 for the class and one for the constructor. We stripped
25182 specialized args for further enclosing classes above. */
25186 /* Template args for translating references to the two-level template
25187 parameters into references to the one-level template parameters we
25188 are creating. */
25193 /* Template parms for the constructor template. */
25196 /* Template parms for the class template. */
25200 /* Template parms for the deduction guide start as a copy of the
25201 template parms for the class. We set current_template_parms for
25202 lookup_template_class_1. */
25208 /* Now we need to rewrite the constructor parms to append them to the
25209 class parms. */
25211 {
25226 }
25228 /* Now we have a final set of template parms to substitute into the
25229 function signature. */
25239 }
25240 }
25243 {
25244 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25248 }
25252 FUNCTION_DECL,
25269 }
25271 /* Deduce template arguments for the class template placeholder PTYPE for
25272 template TMPL based on the initializer INIT, and return the resulting
25273 type. */
25275 static tree
25277 tsubst_flags_t complain)
25278 {
25280 {
25281 /* We should have handled this in the caller. */
25287 }
25299 else
25310 /* Prune explicit deduction guides in copy-initialization context. */
25312 {
25318 {
25319 /* Found a nonconverting guide, prune the candidates. */
25326 }
25327 }
25332 {
25335 }
25339 // FIXME cache artificial deduction guides
25342 {
25347 else
25351 }
25354 {
25363 {
25368 else
25370 }
25371 }
25374 {
25376 " of %qT, as it has no non-explicit deduction guides or "
25379 }
25385 {
25391 }
25397 }
25399 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25400 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25402 tree
25404 {
25406 tf_warning_or_error,
25407 adc_unspecified);
25408 }
25410 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25411 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25412 The CONTEXT determines the context in which auto deduction is performed
25413 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25414 OUTER_TARGS are used during template argument deduction
25415 (context == adc_unify) to properly substitute the result, and is ignored
25416 in other contexts.
25418 For partial-concept-ids, extra args may be appended to the list of deduced
25419 template arguments prior to determining constraint satisfaction. */
25421 tree
25425 {
25426 tree targs;
25433 /* Defining a subset of type-dependent expressions that we can deduce
25434 from ahead of time isn't worth the trouble. */
25438 /* C++17 class template argument deduction. */
25442 /* Nothing we can do with this, even in deduction context. */
25445 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25446 with either a new invented type template parameter U or, if the
25447 initializer is a braced-init-list (8.5.4), with
25448 std::initializer_list<U>. */
25450 {
25455 else
25456 {
25458 {
25462 "for deduction to %<std::initializer_list%>, use copy-"
25464 }
25466 }
25467 }
25478 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25479 and initializer has array type, deduce cv-qualified array type. */
25481 complain);
25483 {
25492 {
25496 }
25497 }
25498 else
25499 {
25501 tree tparms;
25505 else
25506 {
25510 }
25517 {
25519 /* Try again at instantiation time. */
25523 /* If type is error_mark_node a diagnostic must have been
25524 emitted by now. Also, having a mention to '<type error>'
25525 in the diagnostic is not really useful to the user. */
25526 {
25530 else
25535 }
25537 }
25538 }
25540 /* Check any placeholder constraints against the deduced type. */
25543 {
25544 /* Use the deduced type to check the associated constraints. If we
25545 have a partial-concept-id, rebuild the argument list so that
25546 we check using the extra arguments. */
25550 {
25553 }
25554 else
25557 {
25559 {
25561 {
25579 }
25581 }
25583 }
25584 }
25590 }
25592 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25593 result. */
25595 tree
25597 {
25599 {
25605 /* In an abbreviated function template we didn't know we were dealing
25606 with a function template when we saw the auto return type, so update
25607 it to have the correct level. */
25609 }
25611 }
25613 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25614 'decltype(auto)' or a deduced class template. */
25616 bool
25618 {
25624 else
25626 }
25628 /* for_each_template_parm callback for type_uses_auto. */
25630 int
25632 {
25634 }
25636 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25637 a use of `auto'. Returns NULL_TREE otherwise. */
25639 tree
25641 {
25645 {
25646 /* The Concepts TS allows multiple autos in one type-specifier; just
25647 return the first one we find, do_auto_deduction will collect all of
25648 them. */
25652 else
25654 }
25655 else
25657 }
25659 /* For a given template T, return the vector of typedefs referenced
25660 in T for which access check is needed at T instantiation time.
25661 T is either a FUNCTION_DECL or a RECORD_TYPE.
25662 Those typedefs were added to T by the function
25663 append_type_to_template_for_access_check. */
25667 {
25668 tree ti;
25679 {
25684 }
25687 }
25689 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25690 tied to T. That list of typedefs will be access checked at
25691 T instantiation time.
25692 T is either a FUNCTION_DECL or a RECORD_TYPE.
25693 TYPE_DECL is a TYPE_DECL node representing a typedef.
25694 SCOPE is the scope through which TYPE_DECL is accessed.
25695 LOCATION is the location of the usage point of TYPE_DECL.
25697 This function is a subroutine of
25698 append_type_to_template_for_access_check. */
25700 static void
25702 tree type_decl,
25703 tree scope,
25704 location_t location)
25705 {
25706 qualified_typedef_usage_t typedef_usage;
25707 tree ti;
25714 && type_decl
25728 }
25730 /* Append TYPE_DECL to the template TEMPL.
25731 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25732 At TEMPL instanciation time, TYPE_DECL will be checked to see
25733 if it can be accessed through SCOPE.
25734 LOCATION is the location of the usage point of TYPE_DECL.
25736 e.g. consider the following code snippet:
25738 class C
25739 {
25740 typedef int myint;
25741 };
25743 template<class U> struct S
25744 {
25745 C::myint mi; // <-- usage point of the typedef C::myint
25746 };
25748 S<char> s;
25750 At S<char> instantiation time, we need to check the access of C::myint
25751 In other words, we need to check the access of the myint typedef through
25752 the C scope. For that purpose, this function will add the myint typedef
25753 and the scope C through which its being accessed to a list of typedefs
25754 tied to the template S. That list will be walked at template instantiation
25755 time and access check performed on each typedefs it contains.
25756 Note that this particular code snippet should yield an error because
25757 myint is private to C. */
25759 void
25761 tree type_decl,
25762 tree scope,
25763 location_t location)
25764 {
25770 /* Make sure we don't append the type to the template twice. */
25777 }
25779 /* Convert the generic type parameters in PARM that match the types given in the
25780 range [START_IDX, END_IDX) from the current_template_parms into generic type
25781 packs. */
25783 tree
25785 {
25796 {
25797 /* Create a distinct parameter pack type from the current parm and add it
25798 to the replacement args to tsubst below into the generic function
25799 parameter. */
25814 }
25820 /* If there are more levels then build up the replacement with the outer
25821 template parms. */
25825 replacement);
25828 }
25830 /* Entries in the decl_constraint hash table. */
25832 {
25833 tree decl;
25834 tree ci;
25835 };
25837 /* Hashing function and equality for constraint entries. */
25839 {
25841 {
25843 }
25846 {
25848 }
25849 };
25851 /* A mapping from declarations to constraint information. Note that
25852 both templates and their underlying declarations are mapped to the
25853 same constraint information.
25855 FIXME: This is defined in pt.c because garbage collection
25856 code is not being generated for constraint.cc. */
25860 /* Returns the template constraints of declaration T. If T is not
25861 constrained, return NULL_TREE. Note that T must be non-null. */
25863 tree
25865 {
25876 else
25878 }
25880 /* Associate the given constraint information CI with the declaration
25881 T. If T is a template, then the constraints are associated with
25882 its underlying declaration. Don't build associations if CI is
25883 NULL_TREE. */
25885 void
25887 {
25899 }
25901 /* Remove the associated constraints of the declaration T. */
25903 void
25905 {
25914 }
25916 /* Memoized satisfaction results for declarations. This
25917 maps the pair (constraint_info, arguments) to the result computed
25918 by constraints_satisfied_p. */
25921 {
25922 tree ci;
25923 tree args;
25924 tree result;
25925 };
25927 /* Hashing function and equality for constraint entries. */
25930 {
25932 {
25935 }
25938 {
25940 }
25941 };
25943 /* Memoized satisfaction results for concept checks. */
25946 {
25947 tree tmpl;
25948 tree args;
25949 tree result;
25950 };
25952 /* Hashing function and equality for constraint entries. */
25955 {
25957 {
25959 }
25962 {
25967 }
25968 };
25973 /* Search for a memoized satisfaction result. Returns one of the
25974 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25976 tree
25978 {
25983 else
25985 }
25987 /* Memoize the result of a satisfication test. Returns the saved result. */
25989 tree
25991 {
25998 }
26000 /* Search for a memoized satisfaction result for a concept. */
26002 tree
26004 {
26009 else
26011 }
26013 /* Memoize the result of a concept check. Returns the saved result. */
26015 tree
26017 {
26024 }
26028 /* Returns a prior concept specialization. This returns the substituted
26029 and normalized constraints defined by the concept. */
26031 tree
26033 {
26038 else
26040 }
26042 /* Save a concept expansion for later. */
26044 tree
26046 {
26053 }
26055 static hashval_t
26057 {
26066 }
26068 /* Compare the constraints of two subsumption entries. The LEFT1 and
26069 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26070 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26072 static bool
26074 {
26082 }
26084 /* Key/value pair for learning and memoizing subsumption results. This
26085 associates a pair of check constraints (including arguments) with
26086 a boolean value indicating the result. */
26089 {
26090 tree t1;
26091 tree t2;
26093 };
26095 /* Hashing function and equality for constraint entries. */
26098 {
26100 {
26102 }
26105 {
26110 }
26111 };
26115 /* Search for a previously cached subsumption result. */
26119 {
26124 else
26126 }
26128 /* Save a subsumption result. */
26130 bool
26132 {
26139 }
26141 /* Set up the hash table for constraint association. */
26143 void
26145 {
26154 }
26156 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26157 0..N-1. */
26159 void
26161 {
26164 integer_type_node,
26165 NULL_TREE),
26169 }
26171 /* Set up the hash tables for template instantiations. */
26173 void
26175 {
26181 }
26183 /* Print stats about the template hash tables for -fstats. */
26185 void
26187 {
26196 }