| blob | e5238ad2fa5ced2d88b69077e6b7616431e04966 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
44 /* The type of functions taking a tree, and some additional data, and
45 returning an int. */
48 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
49 instantiations have been deferred, either because their definitions
50 were not yet available, or because we were putting off doing the work. */
54 };
69 /* Live only within one (recursive) call to tsubst_expr. We use
70 this to pass the statement expression node from the STMT_EXPR
71 to the EXPR_STMT that is its result. */
74 // -------------------------------------------------------------------------- //
75 // Local Specialization Stack
76 //
77 // Implementation of the RAII helper for creating new local
78 // specializations.
81 {
83 }
86 {
89 }
91 /* True if we've recursed into fn_type_unification too many times. */
95 {
96 tree tmpl;
97 tree args;
98 tree spec;
99 };
102 {
105 };
111 /* Contains canonical template parameter types. The vector is indexed by
112 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
113 TREE_LIST, whose TREE_VALUEs contain the canonical template
114 parameters of various types and levels. */
117 #define UNIFY_ALLOW_NONE 0
118 #define UNIFY_ALLOW_MORE_CV_QUAL 1
119 #define UNIFY_ALLOW_LESS_CV_QUAL 2
120 #define UNIFY_ALLOW_DERIVED 4
121 #define UNIFY_ALLOW_INTEGER 8
122 #define UNIFY_ALLOW_OUTER_LEVEL 16
123 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
124 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
127 tbr_incomplete_type,
128 tbr_ambiguous_baseclass,
129 tbr_success
130 };
153 tree);
210 location_t);
220 /* Make the current scope suitable for access checking when we are
221 processing T. T can be FUNCTION_DECL for instantiated function
222 template, VAR_DECL for static member variable, or TYPE_DECL for
223 alias template (needed by instantiate_decl). */
225 static void
227 {
235 else
239 {
240 saved_access_scope = tree_cons
243 }
244 }
246 /* Restore the scope set up by push_access_scope. T is the node we
247 are processing. */
249 static void
251 {
253 {
256 }
260 else
262 }
264 /* Do any processing required when DECL (a member template
265 declaration) is finished. Returns the TEMPLATE_DECL corresponding
266 to DECL, unless it is a specialization, in which case the DECL
267 itself is returned. */
269 tree
271 {
278 {
279 tree type;
287 {
291 }
293 }
297 {
299 {
302 }
303 else
305 }
306 else
310 }
312 /* Create a template info node. */
314 tree
316 {
321 }
323 /* Return the template info node corresponding to T, whatever T is. */
325 tree
327 {
349 }
351 /* Returns the template nesting level of the indicated class TYPE.
353 For example, in:
354 template <class T>
355 struct A
356 {
357 template <class U>
358 struct B {};
359 };
361 A<T>::B<U> has depth two, while A<T> has depth one.
362 Both A<T>::B<int> and A<int>::B<U> have depth one, if
363 they are instantiations, not specializations.
365 This function is guaranteed to return 0 if passed NULL_TREE so
366 that, for example, `template_class_depth (current_class_type)' is
367 always safe. */
369 int
371 {
375 {
386 else
388 }
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Returns true if processing DECL needs us to push template parms. */
396 static bool
398 {
404 }
406 /* Subroutine of maybe_begin_member_template_processing.
407 Push the template parms in PARMS, starting from LEVELS steps into the
408 chain, and ending at the beginning, since template parms are listed
409 innermost first. */
411 static void
413 {
421 current_template_parms
427 NULL);
429 {
438 {
445 /* Push the CONST_DECL. */
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to insert the TEMPLATE_DECL for S2
653 at the right scope. */
659 /* Add a dummy parameter level while we process the parameter list. */
660 current_template_parms
663 current_template_parms);
664 }
666 /* This routine is called when a specialization is declared. If it is
667 invalid to declare a specialization here, an error is reported and
668 false is returned, otherwise this routine will return true. */
670 static bool
672 {
675 /* [temp.expl.spec]
677 An explicit specialization shall be declared in the namespace of
678 which the template is a member, or, for member templates, in the
679 namespace of which the enclosing class or enclosing class
680 template is a member. An explicit specialization of a member
681 function, member class or static data member of a class template
682 shall be declared in the namespace of which the class template
683 is a member. */
685 {
688 }
690 /* [temp.expl.spec]
692 In an explicit specialization declaration for a member of a class
693 template or a member template that appears in namespace scope,
694 the member template and some of its enclosing class templates may
695 remain unspecialized, except that the declaration shall not
696 explicitly specialize a class member template if its enclosing
697 class templates are not explicitly specialized as well. */
699 {
702 }
705 }
707 /* We've just seen template <>. */
709 bool
711 {
715 }
717 /* Called at then end of processing a declaration preceded by
718 template<>. */
720 void
722 {
725 }
727 /* Any template <>'s that we have seen thus far are not referring to a
728 function specialization. */
730 void
732 {
735 }
737 /* We've just seen a template header. If SPECIALIZATION is nonzero,
738 it was of the form template <>. */
740 static void
742 {
744 template_header_count++;
745 }
747 /* We're beginning an explicit instantiation. */
749 void
751 {
754 }
757 void
759 {
762 }
764 /* An explicit specialization or partial specialization of TMPL is being
765 declared. Check that the namespace in which the specialization is
766 occurring is permissible. Returns false iff it is invalid to
767 specialize TMPL in the current namespace. */
769 static bool
771 {
774 /* [tmpl.expl.spec]
776 An explicit specialization shall be declared in a namespace enclosing the
777 specialized template. An explicit specialization whose declarator-id is
778 not qualified shall be declared in the nearest enclosing namespace of the
779 template, or, if the namespace is inline (7.3.1), any namespace from its
780 enclosing namespace set. */
783 {
786 }
789 /* Same or enclosing namespace. */
791 else
792 {
798 }
799 }
801 /* SPEC is an explicit instantiation. Check that it is valid to
802 perform this explicit instantiation in the current namespace. */
804 static void
806 {
807 tree ns;
809 /* DR 275: An explicit instantiation shall appear in an enclosing
810 namespace of its template. */
816 }
818 // Returns the type of a template specialization only if that
819 // specialization needs to be defined. Otherwise (e.g., if the type has
820 // already been defined), the function returns NULL_TREE.
821 static tree
823 {
824 // An implicit instantiation of an incomplete type implies
825 // the definition of a new class template.
826 //
827 // template<typename T>
828 // struct S;
829 //
830 // template<typename T>
831 // struct S<T*>;
832 //
833 // Here, S<T*> is an implicit instantiation of S whose type
834 // is incomplete.
838 // It can also be the case that TYPE is a completed specialization.
839 // Continuing the previous example, suppose we also declare:
840 //
841 // template<typename T>
842 // requires Integral<T>
843 // struct S<T*>;
844 //
845 // Here, S<T*> refers to the specialization S<T*> defined
846 // above. However, we need to differentiate definitions because
847 // we intend to define a new partial specialization. In this case,
848 // we rely on the fact that the constraints are different for
849 // this declaration than that above.
850 //
851 // Note that we also get here for injected class names and
852 // late-parsed template definitions. We must ensure that we
853 // do not create new type declarations for those cases.
855 {
859 // If there are no template parameters, this cannot be a new
860 // partial template specializtion?
864 // The injected-class-name is not a new partial specialization.
868 // If the constraints are not the same as those of the primary
869 // then, we can probably create a new specialization.
873 {
877 }
879 // Also, if there's a pre-existing specialization with matching
880 // constraints, then this also isn't new.
883 {
891 }
893 // Create a new type node (and corresponding type decl)
894 // for the newly declared specialization.
899 /* We only need a separate type node for storing the definition of this
900 partial specialization; uses of S<T*> are unconstrained, so all are
901 equivalent. So keep TYPE_CANONICAL the same. */
904 // Build the corresponding type decl.
910 }
913 }
915 /* The TYPE is being declared. If it is a template type, that means it
916 is a partial specialization. Do appropriate error-checking. */
918 tree
920 {
921 tree context;
926 /* A lambda that appears in specialization context is not itself a
927 specialization. */
932 {
936 }
941 {
947 else
950 }
952 {
953 /* This is for ordinary explicit specialization and partial
954 specialization of a template class such as:
956 template <> class C<int>;
958 or:
960 template <class T> class C<T*>;
962 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
965 {
972 {
977 }
978 }
984 /* Trying to define a specialization either without a template<> header
985 or in an inappropriate place. We've already given an error, so just
986 bail now so we don't actually define the specialization. */
988 }
994 {
995 /* This is for an explicit specialization of member class
996 template according to [temp.expl.spec/18]:
998 template <> template <class U> class C<int>::D;
1000 The context `C<int>' must be an implicit instantiation.
1001 Otherwise this is just a member class template declared
1002 earlier like:
1004 template <> class C<int> { template <class U> class D; };
1005 template <> template <class U> class C<int>::D;
1007 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1008 while in the second case, `C<int>::D' is a primary template
1009 and `C<T>::D' may not exist. */
1013 {
1014 tree t;
1019 {
1024 }
1026 /* Check for invalid specialization after instantiation:
1028 template <> template <> class C<int>::D<int>;
1029 template <> template <class U> class C<int>::D; */
1033 {
1037 {
1038 /* We already have a full specialization of this partial
1039 instantiation, or a full specialization has been
1040 looked up but not instantiated. Reassign it to the
1041 new member specialization template. */
1042 spec_entry elt;
1054 spec_entry **slot
1059 }
1060 else
1061 /* But if we've had an implicit instantiation, that's a
1062 problem ([temp.expl.spec]/6). */
1065 }
1067 /* Mark TYPE as a specialization. And as a result, we only
1068 have one level of template argument for the innermost
1069 class template. */
1074 }
1075 }
1077 {
1078 /* Someday C++0x may allow for enum template specialization. */
1083 else
1084 {
1087 }
1088 }
1091 }
1093 /* Returns nonzero if we can optimize the retrieval of specializations
1094 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1095 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1099 {
1102 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1103 parameter. */
1105 /* The optimized lookup depends on the fact that the
1106 template arguments for the member function template apply
1107 purely to the containing class, which is not true if the
1108 containing class is an explicit or partial
1109 specialization. */
1113 /* It is possible to have a template that is not a member
1114 template and is not a member of a template class:
1116 template <typename T>
1117 struct S { friend A::f(); };
1119 Here, the friend function is a template, but the context does
1120 not have template information. The optimized lookup relies
1121 on having ARGS be the template arguments for both the class
1122 and the function template. */
1124 }
1126 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1127 gone through coerce_template_parms by now. */
1129 static void
1131 {
1134 {
1137 {
1144 /* Allow typedefs on the type of a non-type argument, since a
1146 else
1148 }
1149 }
1151 }
1153 /* Retrieve the specialization (in the sense of [temp.spec] - a
1154 specialization is either an instantiation or an explicit
1155 specialization) of TMPL for the given template ARGS. If there is
1156 no such specialization, return NULL_TREE. The ARGS are a vector of
1157 arguments, or a vector of vectors of arguments, in the case of
1158 templates with more than one level of parameters.
1160 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1161 then we search for a partial specialization matching ARGS. This
1162 parameter is ignored if TMPL is not a class template.
1164 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1165 result is a NONTYPE_ARGUMENT_PACK. */
1167 static tree
1169 {
1179 /* There should be as many levels of arguments as there are
1180 levels of parameters. */
1190 {
1191 /* The template arguments actually apply to the containing
1192 class. Find the class specialization with those
1193 arguments. */
1195 tree class_specialization
1199 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1200 for the specialization. */
1204 /* Iterate through the methods with the indicated name, looking
1205 for the one that has an instance of TMPL. */
1208 {
1211 /* using-declarations can add base methods to the method vec,
1212 and we don't want those here. */
1215 }
1217 }
1218 else
1219 {
1221 spec_entry elt;
1230 else
1238 }
1241 }
1243 /* Like retrieve_specialization, but for local declarations. */
1245 tree
1247 {
1253 }
1255 /* Returns nonzero iff DECL is a specialization of TMPL. */
1257 int
1259 {
1260 tree t;
1263 {
1269 }
1270 else
1271 {
1280 }
1283 }
1285 /* Returns nonzero iff DECL is a specialization of friend declaration
1286 FRIEND_DECL according to [temp.friend]. */
1288 bool
1290 {
1297 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1298 of a template class, we want to check if DECL is a specialization
1299 if this. */
1303 {
1304 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1307 }
1312 /* There is nothing to do if this is not a template friend. */
1319 /* [temp.friend/6]
1320 A member of a class template may be declared to be a friend of a
1321 non-template class. In this case, the corresponding member of
1322 every specialization of the class template is a friend of the
1323 class granting friendship.
1325 For example, given a template friend declaration
1327 template <class T> friend void A<T>::f();
1329 the member function below is considered a friend
1331 template <> struct A<int> {
1332 void f();
1333 };
1335 For this type of template friend, TEMPLATE_DEPTH below will be
1336 nonzero. To determine if DECL is a friend of FRIEND, we first
1337 check if the enclosing class is a specialization of another. */
1344 {
1345 /* Next, we check the members themselves. In order to handle
1346 a few tricky cases, such as when FRIEND_DECL's are
1348 template <class T> friend void A<T>::g(T t);
1349 template <class T> template <T t> friend void A<T>::h();
1351 and DECL's are
1353 void A<int>::g(int);
1354 template <int> void A<int>::h();
1356 we need to figure out ARGS, the template arguments from
1357 the context of DECL. This is required for template substitution
1358 of `T' in the function parameter of `g' and template parameter
1359 of `h' in the above examples. Here ARGS corresponds to `int'. */
1366 {
1368 {
1371 else
1373 current_depth++;
1374 }
1376 }
1379 {
1381 tree friend_type;
1382 tree decl_type;
1383 tree friend_args_type;
1384 tree decl_args_type;
1386 /* Make sure that both DECL and FRIEND_DECL are templates or
1387 non-templates. */
1393 {
1394 /* If both are templates, check template parameter list. */
1395 tree friend_parms
1400 friend_parms))
1404 }
1405 else
1413 /* Check if return types match. */
1417 /* Check if function parameter types match, ignoring the
1418 `this' parameter. */
1427 }
1428 else
1429 {
1430 /* DECL is a TYPE_DECL */
1434 /* Make sure that both DECL and FRIEND_DECL are templates or
1435 non-templates. */
1436 is_template
1443 {
1444 tree friend_parms;
1445 /* If both are templates, check the name of the two
1446 TEMPLATE_DECL's first because is_friend didn't. */
1451 /* Now check template parameter list. */
1452 friend_parms
1455 return comp_template_parms
1457 friend_parms);
1458 }
1459 else
1462 }
1463 }
1465 }
1467 /* Register the specialization SPEC as a specialization of TMPL with
1468 the indicated ARGS. IS_FRIEND indicates whether the specialization
1469 is actually just a friend declaration. Returns SPEC, or an
1470 equivalent prior declaration, if available.
1472 We also store instantiations of field packs in the hash table, even
1473 though they are not themselves templates, to make lookup easier. */
1475 static tree
1477 hashval_t hash)
1478 {
1479 tree fn;
1481 spec_entry elt;
1489 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1490 register it; we want the corresponding TEMPLATE_DECL instead.
1491 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1492 the more obvious `uses_template_parms (spec)' to avoid problems
1493 with default function arguments. In particular, given
1494 something like this:
1496 template <class T> void f(T t1, T t = T())
1498 the default argument expression is not substituted for in an
1499 instantiation unless and until it is actually needed. */
1503 /* We don't put these specializations in the hash table, but we might
1504 want to give an error about a mismatch. */
1506 else
1507 {
1515 slot =
1519 else
1521 }
1523 /* We can sometimes try to re-register a specialization that we've
1524 already got. In particular, regenerate_decl_from_template calls
1525 duplicate_decls which will update the specialization list. But,
1526 we'll still get called again here anyhow. It's more convenient
1527 to simply allow this than to try to prevent it. */
1531 {
1533 {
1536 {
1538 fn);
1540 }
1541 else
1542 {
1543 tree clone;
1544 /* This situation should occur only if the first
1545 specialization is an implicit instantiation, the
1546 second is an explicit specialization, and the
1547 implicit instantiation has not yet been used. That
1548 situation can occur if we have implicitly
1549 instantiated a member function and then specialized
1550 it later.
1552 We can also wind up here if a friend declaration that
1553 looked like an instantiation turns out to be a
1554 specialization:
1556 template <class T> void foo(T);
1557 class S { friend void foo<>(int) };
1558 template <> void foo(int);
1560 We transform the existing DECL in place so that any
1561 pointers to it become pointers to the updated
1562 declaration.
1564 If there was a definition for the template, but not
1565 for the specialization, we want this to look as if
1566 there were no definition, and vice versa. */
1569 /* The call to duplicate_decls will have applied
1570 [temp.expl.spec]:
1572 An explicit specialization of a function template
1573 is inline only if it is explicitly declared to be,
1574 and independently of whether its function template
1575 is.
1577 to the primary function; now copy the inline bits to
1578 the various clones. */
1580 {
1587 }
1591 }
1592 }
1594 {
1597 /* We've already complained in duplicate_decls. */
1601 /* Dup decl failed, but this is a new definition. Set the
1602 line number so any errors match this new
1603 definition. */
1607 }
1608 }
1612 /* A specialization must be declared in the same namespace as the
1613 template it is specializing. */
1619 {
1628 /* If TMPL is a forward declaration of a template function, keep a list
1629 of all specializations in case we need to reassign them to a friend
1630 template later in tsubst_friend_function.
1632 Also keep a list of all variable template instantiations so that
1633 process_partial_specialization can check whether a later partial
1634 specialization would have used it. */
1637 }
1640 }
1642 /* Returns true iff two spec_entry nodes are equivalent. */
1646 bool
1648 {
1655 /* tmpl could be a FIELD_DECL for a capture pack. */
1659 {
1660 /* Partial specializations of a variable template can be distinguished by
1661 constraints. */
1665 }
1669 }
1671 /* Returns a hash for a template TMPL and template arguments ARGS. */
1673 static hashval_t
1675 {
1678 }
1680 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1681 ignoring SPEC. */
1683 hashval_t
1685 {
1687 }
1689 /* Recursively calculate a hash value for a template argument ARG, for use
1690 in the hash tables of template specializations. */
1692 hashval_t
1694 {
1714 {
1722 {
1727 }
1749 {
1753 {
1756 }
1758 }
1762 {
1765 }
1776 val = iterative_hash_template_arg
1788 val);
1790 val);
1799 /* A lambda can't appear in a template arg, but don't crash on
1800 erroneous input. */
1812 /* Now hash operands as usual. */
1817 }
1820 {
1823 {
1824 // We want an alias specialization that survived strip_typedefs
1825 // to hash differently from its TYPE_CANONICAL, to avoid hash
1826 // collisions that compare as different in template_args_equal.
1827 // These could be dependent specializations that strip_typedefs
1828 // left alone, or untouched specializations because
1829 // coerce_template_parms returns the unconverted template
1830 // arguments if it sees incomplete argument packs.
1833 }
1836 val);
1839 /* Otherwise just compare the types during lookup. */
1848 {
1853 }
1854 }
1857 }
1859 /* Unregister the specialization SPEC as a specialization of TMPL.
1860 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1861 if the SPEC was listed as a specialization of TMPL.
1863 Note that SPEC has been ggc_freed, so we can't look inside it. */
1865 bool
1867 {
1869 spec_entry elt;
1877 {
1882 }
1885 }
1887 /* Like register_specialization, but for local declarations. We are
1888 registering SPEC, an instantiation of TMPL. */
1890 void
1892 {
1894 }
1896 /* TYPE is a class type. Returns true if TYPE is an explicitly
1897 specialized class. */
1899 bool
1901 {
1905 }
1907 /* Print the list of functions at FNS, going through all the overloads
1908 for each element of the list. Alternatively, FNS can not be a
1909 TREE_LIST, in which case it will be printed together with all the
1910 overloads.
1912 MORE and *STR should respectively be FALSE and NULL when the function
1913 is called from the outside. They are used internally on recursive
1914 calls. print_candidates manages the two parameters and leaves NULL
1915 in *STR when it ends. */
1917 static void
1919 {
1923 else
1925 {
1931 {
1934 else
1937 }
1939 }
1940 }
1942 /* Print the list of candidate FNS in an error message. FNS can also
1943 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1945 void
1947 {
1951 }
1953 /* Get a (possibly) constrained template declaration for the
1954 purpose of ordering candidates. */
1955 static tree
1957 {
1963 }
1965 /* Among candidates having the same signature, return the
1966 most constrained or NULL_TREE if there is no best candidate.
1967 If the signatures of candidates vary (e.g., template
1968 specialization vs. member function), then there can be no
1969 most constrained.
1971 Note that we don't compare constraints on the functions
1972 themselves, but rather those of their templates. */
1973 static tree
1975 {
1976 // Try to find the best candidate in a first pass.
1979 {
1986 }
1988 // Verify that the champ is better than previous candidates.
1993 }
1996 }
1999 /* Returns the template (one of the functions given by TEMPLATE_ID)
2000 which can be specialized to match the indicated DECL with the
2001 explicit template args given in TEMPLATE_ID. The DECL may be
2002 NULL_TREE if none is available. In that case, the functions in
2003 TEMPLATE_ID are non-members.
2005 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2006 specialization of a member template.
2008 The TEMPLATE_COUNT is the number of references to qualifying
2009 template classes that appeared in the name of the function. See
2010 check_explicit_specialization for a more accurate description.
2012 TSK indicates what kind of template declaration (if any) is being
2013 declared. TSK_TEMPLATE indicates that the declaration given by
2014 DECL, though a FUNCTION_DECL, has template parameters, and is
2015 therefore a template function.
2017 The template args (those explicitly specified and those deduced)
2018 are output in a newly created vector *TARGS_OUT.
2020 If it is impossible to determine the result, an error message is
2021 issued. The error_mark_node is returned to indicate failure. */
2023 static tree
2025 tree decl,
2029 tmpl_spec_kind tsk)
2030 {
2031 tree fns;
2032 tree targs;
2033 tree explicit_targs;
2036 /* A TREE_LIST of templates of which DECL may be a specialization.
2037 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2038 corresponding TREE_PURPOSE is the set of template arguments that,
2039 when used to instantiate the template, would produce a function
2040 with the signature of DECL. */
2050 /* We shouldn't be specializing a member template of an
2051 unspecialized class template; we already gave an error in
2052 check_specialization_scope, now avoid crashing. */
2055 {
2058 }
2066 /* Check for baselinks. */
2071 {
2074 }
2076 {
2079 }
2081 /* Count the number of template headers specified for this
2082 specialization. */
2092 {
2095 tf_warning_or_error,
2099 }
2101 {
2105 {
2106 tree decl_arg_types;
2107 tree fn_arg_types;
2108 tree insttype;
2110 /* In case of explicit specialization, we need to check if
2111 the number of template headers appearing in the specialization
2112 is correct. This is usually done in check_explicit_specialization,
2113 but the check done there cannot be exhaustive when specializing
2114 member functions. Consider the following code:
2116 template <> void A<int>::f(int);
2117 template <> template <> void A<int>::f(int);
2119 Assuming that A<int> is not itself an explicit specialization
2120 already, the first line specializes "f" which is a non-template
2121 member function, whilst the second line specializes "f" which
2122 is a template member function. So both lines are syntactically
2123 correct, and check_explicit_specialization does not reject
2124 them.
2126 Here, we can do better, as we are matching the specialization
2127 against the declarations. We count the number of template
2128 headers, and we check if they match TEMPLATE_COUNT + 1
2129 (TEMPLATE_COUNT is the number of qualifying template classes,
2130 plus there must be another header for the member template
2131 itself).
2133 Notice that if header_count is zero, this is not a
2134 specialization but rather a template instantiation, so there
2135 is no check we can perform here. */
2139 /* Check that the number of template arguments at the
2140 innermost level for DECL is the same as for FN. */
2148 /* DECL might be a specialization of FN. */
2152 /* For a non-static member function, we need to make sure
2153 that the const qualification is the same. Since
2154 get_bindings does not try to merge the "this" parameter,
2155 we must do the comparison explicitly. */
2161 /* Skip the "this" parameter and, for constructors of
2162 classes with virtual bases, the VTT parameter. A
2163 full specialization of a constructor will have a VTT
2164 parameter, but a template never will. */
2165 decl_arg_types
2167 fn_arg_types
2170 /* Function templates cannot be specializations; there are
2171 no partial specializations of functions. Therefore, if
2172 the type of DECL does not match FN, there is no
2173 match.
2175 Note that it should never be the case that we have both
2176 candidates added here, and for regular member functions
2177 below. */
2179 {
2183 }
2185 /* See whether this function might be a specialization of this
2186 template. Suppress access control because we might be trying
2187 to make this specialization a friend, and we have already done
2188 access control for the declaration of the specialization. */
2194 /* We cannot deduce template arguments that when used to
2195 specialize TMPL will produce DECL. */
2198 /* Remove, from the set of candidates, all those functions
2199 whose constraints are not satisfied. */
2203 // Then, try to form the new function type.
2207 fn_arg_types
2212 /* Save this template, and the arguments deduced. */
2214 }
2216 /* FN is an ordinary member function, and we need a
2217 specialization of a member template. */
2218 ;
2220 /* We can get IDENTIFIER_NODEs here in certain erroneous
2221 cases. */
2222 ;
2224 /* This is just an ordinary non-member function. Nothing can
2225 be a specialization of that. */
2226 ;
2228 /* Cannot specialize functions that are created implicitly. */
2229 ;
2230 else
2231 {
2232 tree decl_arg_types;
2234 /* This is an ordinary member function. However, since
2235 we're here, we can assume its enclosing class is a
2236 template class. For example,
2238 template <typename T> struct S { void f(); };
2239 template <> void S<int>::f() {}
2241 Here, S<int>::f is a non-template, but S<int> is a
2242 template class. If FN has the same type as DECL, we
2243 might be in business. */
2246 /* Its enclosing class is an explicit specialization
2247 of a template class. This is not a candidate. */
2252 /* The return types differ. */
2255 /* Adjust the type of DECL in case FN is a static member. */
2262 decl_arg_types))
2265 // If the deduced arguments do not satisfy the constraints,
2266 // this is not a candidate.
2270 // Add the candidate.
2272 }
2273 }
2276 {
2277 /* We have:
2279 [temp.expl.spec]
2281 It is possible for a specialization with a given function
2282 signature to be instantiated from more than one function
2283 template. In such cases, explicit specification of the
2284 template arguments must be used to uniquely identify the
2285 function template specialization being specialized.
2287 Note that here, there's no suggestion that we're supposed to
2288 determine which of the candidate templates is most
2289 specialized. However, we, also have:
2291 [temp.func.order]
2293 Partial ordering of overloaded function template
2294 declarations is used in the following contexts to select
2295 the function template to which a function template
2296 specialization refers:
2298 -- when an explicit specialization refers to a function
2299 template.
2301 So, we do use the partial ordering rules, at least for now.
2302 This extension can only serve to make invalid programs valid,
2303 so it's safe. And, there is strong anecdotal evidence that
2304 the committee intended the partial ordering rules to apply;
2305 the EDG front end has that behavior, and John Spicer claims
2306 that the committee simply forgot to delete the wording in
2307 [temp.expl.spec]. */
2310 {
2313 }
2314 }
2316 // Concepts allows multiple declarations of member functions
2317 // with the same signature. Like above, we need to rely on
2318 // on the partial ordering of those candidates to determine which
2319 // is the best.
2321 {
2323 {
2326 }
2327 }
2330 {
2337 else
2340 }
2344 {
2350 }
2352 /* We have one, and exactly one, match. */
2354 {
2358 // Propagate the candidate's constraints to the declaration.
2361 /* DECL is a re-declaration or partial instantiation of a template
2362 function. */
2365 /* It was a specialization of an ordinary member function in a
2366 template class. */
2368 }
2370 /* It was a specialization of a template. */
2373 {
2378 }
2379 else
2382 }
2384 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2385 but with the default argument values filled in from those in the
2386 TMPL_TYPES. */
2388 static tree
2390 tree tmpl_types)
2391 {
2392 tree new_spec_types;
2400 /* Substitute into the rest of the list. */
2401 new_spec_types =
2405 /* Add the default argument for this parameter. */
2408 new_spec_types);
2409 }
2411 /* DECL is an explicit specialization. Replicate default arguments
2412 from the template it specializes. (That way, code like:
2414 template <class T> void f(T = 3);
2415 template <> void f(double);
2416 void g () { f (); }
2418 works, as required.) An alternative approach would be to look up
2419 the correct default arguments at the call-site, but this approach
2420 is consistent with how implicit instantiations are handled. */
2422 static void
2424 {
2425 tree tmpl;
2426 tree spec_types;
2427 tree tmpl_types;
2428 tree new_spec_types;
2429 tree old_type;
2430 tree new_type;
2431 tree t;
2436 /* See if there's anything we need to do. */
2449 {
2450 /* Remove the this pointer, but remember the object's type for
2451 CV quals. */
2457 {
2458 /* DECL may contain more parameters than TMPL due to the extra
2459 in-charge parameter in constructors and destructors. */
2462 }
2464 {
2467 }
2468 }
2470 /* Compute the merged default arguments. */
2471 new_spec_types =
2474 /* Compute the new FUNCTION_TYPE. */
2476 {
2480 new_spec_types);
2483 /* Put the in-charge parameter back. */
2486 new_spec_types);
2490 new_spec_types);
2491 }
2492 else
2494 new_spec_types);
2504 }
2506 /* Return the number of template headers we expect to see for a definition
2507 or specialization of CTYPE or one of its non-template members. */
2509 int
2511 {
2515 {
2516 /* You're supposed to have one `template <...>' for every
2517 template class, but you don't need one for a full
2518 specialization. For example:
2520 template <class T> struct S{};
2521 template <> struct S<int> { void f(); };
2522 void S<int>::f () {}
2524 is correct; there shouldn't be a `template <>' for the
2525 definition of `S<int>::f'. */
2527 /* If CTYPE does not have template information of any
2528 kind, then it is not a template, nor is it nested
2529 within a template. */
2537 }
2540 }
2542 /* Do a simple sanity check on the template headers that precede the
2543 variable declaration DECL. */
2545 void
2547 {
2552 {
2555 "variable templates only available with "
2558 // Namespace-scope variable templates should have a template header.
2560 }
2562 {
2564 "too many template headers for %qD "
2570 "members of an explicitly specialized class are defined "
2572 }
2573 }
2575 /* An explicit specialization whose declarator-id or class-head-name is not
2576 qualified shall be declared in the nearest enclosing namespace of the
2577 template, or, if the namespace is inline (7.3.1), any namespace from its
2578 enclosing namespace set.
2580 If the name declared in the explicit instantiation is an unqualified name,
2581 the explicit instantiation shall appear in the namespace where its template
2582 is declared or, if that namespace is inline (7.3.1), any namespace from its
2583 enclosing namespace set. */
2585 void
2587 {
2592 {
2598 /* This was allowed in C++98, so only pedwarn. */
2600 "outside its namespace must use a nested-name-"
2602 }
2603 }
2605 /* Check to see if the function just declared, as indicated in
2606 DECLARATOR, and in DECL, is a specialization of a function
2607 template. We may also discover that the declaration is an explicit
2608 instantiation at this point.
2610 Returns DECL, or an equivalent declaration that should be used
2611 instead if all goes well. Issues an error message if something is
2612 amiss. Returns error_mark_node if the error is not easily
2613 recoverable.
2615 FLAGS is a bitmask consisting of the following flags:
2617 2: The function has a definition.
2618 4: The function is a friend.
2620 The TEMPLATE_COUNT is the number of references to qualifying
2621 template classes that appeared in the name of the function. For
2622 example, in
2624 template <class T> struct S { void f(); };
2625 void S<int>::f();
2627 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2628 classes are not counted in the TEMPLATE_COUNT, so that in
2630 template <class T> struct S {};
2631 template <> struct S<int> { void f(); }
2632 template <> void S<int>::f();
2634 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2635 invalid; there should be no template <>.)
2637 If the function is a specialization, it is marked as such via
2638 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2639 is set up correctly, and it is added to the list of specializations
2640 for that template. */
2642 tree
2644 tree decl,
2647 {
2656 tmpl_spec_kind tsk;
2659 {
2662 else
2664 }
2665 else
2669 {
2672 {
2675 }
2677 {
2679 /* This could be something like:
2681 template <class T> void f(T);
2682 class S { friend void f<>(int); } */
2684 else
2685 {
2686 /* This case handles bogus declarations like template <>
2687 template <class T> void f<int>(); */
2690 declarator);
2692 }
2693 }
2697 /* The error has already been reported in
2698 check_specialization_scope. */
2704 /* Fall through. */
2717 decl);
2720 else
2724 /* Fall through. */
2730 /* In cases like template<> constexpr bool v = true;
2731 We'll give an error in check_template_variable. */
2737 else
2743 {
2744 /* This case handles bogus declarations like template <>
2745 template <class T> void f<int>(); */
2749 declarator);
2751 {
2752 /* Partial specialization of variable template. */
2756 }
2760 else
2764 ok:;
2765 }
2768 /* This is a specialization of a member template, without
2769 specialization the containing class. Something like:
2771 template <class T> struct S {
2772 template <class U> void f (U);
2773 };
2774 template <> template <class U> void S<int>::f(U) {}
2776 That's a specialization -- but of the entire template. */
2782 }
2785 /* This doesn't apply to variable templates. */
2788 {
2792 {
2796 }
2797 }
2800 {
2805 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2807 {
2808 tree fns;
2813 else
2814 {
2815 /* If there is no class context, the explicit instantiation
2816 must be at namespace scope. */
2819 /* Find the namespace binding, using the declaration
2820 context. */
2824 /* If lookup fails, look for a friend declaration so we can
2825 give a better diagnostic. */
2831 {
2834 }
2835 }
2838 }
2844 {
2846 /* A specialization in class scope. This is invalid,
2847 but the error will already have been flagged by
2848 check_specialization_scope. */
2850 else
2851 {
2852 /* It's not valid to write an explicit instantiation in
2853 class scope, e.g.:
2855 class C { template void f(); }
2857 This case is caught by the parser. However, on
2858 something like:
2860 template class C { void f(); };
2862 (which is invalid) we can get here. The error will be
2863 issued later. */
2864 ;
2865 }
2868 }
2871 {
2872 // We'll match variable templates in start_decl.
2876 /* Find the list of functions in ctype that have the same
2877 name as the declared function. */
2883 {
2888 {
2889 /* From [temp.expl.spec]:
2891 If such an explicit specialization for the member
2892 of a class template names an implicitly-declared
2893 special member function (clause _special_), the
2894 program is ill-formed.
2896 Similar language is found in [temp.explicit]. */
2899 }
2902 }
2905 {
2909 }
2910 else
2911 {
2913 tree ovl;
2915 /* For a type-conversion operator, we cannot do a
2916 name-based lookup. We might be looking for `operator
2917 int' which will be a specialization of `operator T'.
2918 So, we find *all* the conversion operators, and then
2919 select from them. */
2927 {
2929 /* There are no more conversion functions. */
2932 /* Glue all these conversion functions together
2933 with those we already have. */
2935 }
2936 }
2939 {
2942 }
2943 else
2945 }
2947 /* Figure out what exactly is being specialized at this point.
2948 Note that for an explicit instantiation, even one for a
2949 member function, we cannot tell a priori whether the
2950 instantiation is for a member template, or just a member
2951 function of a template class. Even if a member template is
2952 being instantiated, the member template arguments may be
2953 elided if they can be deduced from the rest of the
2954 declaration. */
2957 member_specialization,
2958 template_count,
2959 tsk);
2962 /* We couldn't figure out what this declaration was
2963 specializing. */
2965 else
2966 {
2969 {
2971 "friend declaration %qD is not visible to "
2975 }
2983 {
2984 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2985 is done by do_decl_instantiation later. */
2991 {
2992 /* If TMPL is not the most general template (for
2993 example, if TMPL is a friend template that is
2994 injected into namespace scope), then there will
2995 be too many levels of TARGS. Remove some of them
2996 here. */
2998 tree new_targs;
3005 }
3008 }
3010 /* If we thought that the DECL was a member function, but it
3011 turns out to be specializing a static member function,
3012 make DECL a static member function as well. */
3018 /* If this is a specialization of a member template of a
3019 template class, we want to return the TEMPLATE_DECL, not
3020 the specialization of it. */
3022 {
3027 {
3028 tree parm;
3032 /* We want to use the argument list specified in the
3033 definition, not in the original declaration. */
3038 }
3041 }
3043 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3049 /* Inherit default function arguments from the template
3050 DECL is specializing. */
3054 /* This specialization has the same protection as the
3055 template it specializes. */
3059 /* 7.1.1-1 [dcl.stc]
3061 A storage-class-specifier shall not be specified in an
3062 explicit specialization...
3064 The parser rejects these, so unless action is taken here,
3065 explicit function specializations will always appear with
3066 global linkage.
3068 The action recommended by the C++ CWG in response to C++
3069 defect report 605 is to make the storage class and linkage
3070 of the explicit specialization match the templated function:
3072 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3073 */
3075 {
3079 /* A concept cannot be specialized. */
3081 {
3083 gen_tmpl);
3085 }
3087 /* This specialization has the same linkage and visibility as
3088 the function template it specializes. */
3091 {
3094 }
3097 {
3100 }
3101 }
3103 /* If DECL is a friend declaration, declared using an
3104 unqualified name, the namespace associated with DECL may
3105 have been set incorrectly. For example, in:
3107 template <typename T> void f(T);
3108 namespace N {
3109 struct S { friend void f<int>(int); }
3110 }
3112 we will have set the DECL_CONTEXT for the friend
3113 declaration to N, rather than to the global namespace. */
3118 /* This is not really a declaration of a specialization.
3119 It's just the name of an instantiation. But, it's not
3120 a request for an instantiation, either. */
3123 /* A specialization is not necessarily COMDAT. */
3129 /* If this is a full specialization, register it so that we can find
3130 it again. Partial specializations will be registered in
3131 process_partial_specialization. */
3136 /* A 'structor should already have clones. */
3142 }
3143 }
3146 }
3148 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3149 parameters. These are represented in the same format used for
3150 DECL_TEMPLATE_PARMS. */
3152 int
3154 {
3155 const_tree p1;
3156 const_tree p2;
3164 {
3176 {
3180 /* If either of the template parameters are invalid, assume
3181 they match for the sake of error recovery. */
3194 }
3195 }
3198 /* One set of parameters has more parameters lists than the
3199 other. */
3203 }
3205 /* Determine whether PARM is a parameter pack. */
3207 bool
3209 {
3210 /* Determine if we have a non-type template parameter pack. */
3217 /* If this is a list of template parameters, we could get a
3218 TYPE_DECL or a TEMPLATE_DECL. */
3222 /* Otherwise it must be a type template parameter. */
3226 }
3228 /* Determine if T is a function parameter pack. */
3230 bool
3232 {
3236 }
3238 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3239 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3241 tree
3243 {
3250 }
3252 /* Return true iff the function parameter PARAM_DECL was expanded
3253 from the function parameter pack PACK. */
3255 bool
3257 {
3262 /* The parameter pack and its pack arguments have the same
3263 DECL_PARM_INDEX. */
3265 }
3267 /* Determine whether ARGS describes a variadic template args list,
3268 i.e., one that is terminated by a template argument pack. */
3270 static bool
3272 {
3274 tree last_parm;
3288 }
3290 /* Generate a new name for the parameter pack name NAME (an
3291 IDENTIFIER_NODE) that incorporates its */
3293 static tree
3295 {
3296 /* Munge the name to include the parameter index. */
3297 #define NUMBUF_LEN 128
3311 }
3313 /* Return true if T is a primary function, class or alias template
3314 instantiation. */
3316 bool
3318 {
3332 }
3334 /* Return true if PARM is a template template parameter. */
3336 bool
3338 {
3340 }
3342 /* Return true iff PARM is a DECL representing a type template
3343 parameter. */
3345 bool
3347 {
3352 }
3354 /* Return the template parameters of T if T is a
3355 primary template instantiation, NULL otherwise. */
3357 tree
3359 {
3364 parms = INNERMOST_TEMPLATE_PARMS
3368 }
3370 /* Return the template parameters of the LEVELth level from the full list
3371 of template parameters PARMS. */
3373 tree
3375 {
3376 tree p;
3387 }
3389 /* Returns the template arguments of T if T is a template instantiation,
3390 NULL otherwise. */
3392 tree
3394 {
3402 }
3404 /* Return the argument pack elements of T if T is a template argument pack,
3405 NULL otherwise. */
3407 tree
3409 {
3415 }
3417 /* True iff FN is a function representing a built-in variadic parameter
3418 pack. */
3420 bool
3422 {
3432 }
3434 /* True iff CALL is a call to a function representing a built-in variadic
3435 parameter pack. */
3437 static bool
3439 {
3443 }
3445 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3447 static tree
3449 tree in_decl)
3450 {
3456 {
3458 {
3461 }
3466 }
3467 else
3468 {
3472 /* Calculate the largest value of len that won't make the size of the vec
3473 overflow an int. The compiler will exceed resource limits long before
3474 this, but it seems a decent place to diagnose. */
3478 {
3483 }
3491 }
3492 }
3494 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3495 CALL. */
3497 static tree
3499 tree in_decl)
3500 {
3510 }
3512 /* Structure used to track the progress of find_parameter_packs_r. */
3513 struct find_parameter_pack_data
3514 {
3515 /* TREE_LIST that will contain all of the parameter packs found by
3516 the traversal. */
3519 /* Set of AST nodes that have been visited by the traversal. */
3522 /* True iff we're making a type pack expansion. */
3524 };
3526 /* Identifies all of the argument packs that occur in a template
3527 argument and appends them to the TREE_LIST inside DATA, which is a
3528 find_parameter_pack_data structure. This is a subroutine of
3529 make_pack_expansion and uses_parameter_packs. */
3530 static tree
3532 {
3538 /* Handle type aliases/typedefs. */
3540 {
3547 }
3549 /* Identify whether this is a parameter pack or not. */
3551 {
3559 /* FALLTHRU */
3561 /* If the placeholder appears in the decl-specifier-seq of a function
3562 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3563 is a pack expansion, the invented template parameter is a template
3564 parameter pack. */
3574 {
3575 /* We don't want to walk into the type of a PARM_DECL,
3576 because we don't want to see the type parameter pack. */
3579 }
3582 /* Look through a lambda capture proxy to the field pack. */
3585 {
3591 }
3593 {
3595 find_parameter_packs_r,
3598 }
3610 /* Not a parameter pack. */
3612 }
3615 {
3616 /* Add this parameter pack to the list. */
3618 }
3624 /* This switch statement will return immediately if we don't find a
3625 parameter pack. */
3627 {
3632 /* Check the template itself. */
3635 /* Check the template arguments. */
3651 /* Fall through. */
3696 {
3697 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3698 type_pack_expansion_p to false so that any placeholders
3699 within the expression don't get marked as parameter packs. */
3707 }
3711 }
3714 }
3716 /* Determines if the expression or type T uses any parameter packs. */
3717 bool
3719 {
3728 }
3730 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3731 representation a base-class initializer into a parameter pack
3732 expansion. If all goes well, the resulting node will be an
3733 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3734 respectively. */
3735 tree
3737 {
3738 tree result;
3747 {
3748 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3749 class initializer. In this case, the TREE_PURPOSE will be a
3750 _TYPE node (representing the base class expansion we're
3751 initializing) and the TREE_VALUE will be a TREE_LIST
3752 containing the initialization arguments.
3754 The resulting expansion looks somewhat different from most
3755 expansions. Rather than returning just one _EXPANSION, we
3756 return a TREE_LIST whose TREE_PURPOSE is a
3757 TYPE_PACK_EXPANSION containing the bases that will be
3758 initialized. The TREE_VALUE will be identical to the
3759 original TREE_VALUE, which is a list of arguments that will
3760 be passed to each base. We do not introduce any new pack
3761 expansion nodes into the TREE_VALUE (although it is possible
3762 that some already exist), because the TREE_PURPOSE and
3763 TREE_VALUE all need to be expanded together with the same
3764 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3765 resulting TREE_PURPOSE will mention the parameter packs in
3766 both the bases and the arguments to the bases. */
3767 tree purpose;
3768 tree value;
3771 /* Determine which parameter packs will be used by the base
3772 class expansion. */
3781 {
3785 }
3788 {
3789 /* Collect the sets of parameter packs used in each of the
3790 initialization arguments. */
3792 {
3793 /* Determine which parameter packs will be expanded in this
3794 argument. */
3797 }
3798 }
3802 /* Create the pack expansion type for the base type. */
3807 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3808 they will rarely be compared to anything. */
3812 }
3817 /* Build the PACK_EXPANSION_* node. */
3818 result = for_types
3823 {
3824 /* Propagate type and const-expression information. */
3827 /* Mark this read now, since the expansion might be length 0. */
3829 }
3830 else
3831 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3832 they will rarely be compared to anything. */
3835 /* Determine which parameter packs will be expanded. */
3842 /* Make sure we found some parameter packs. */
3844 {
3847 else
3850 }
3856 }
3858 /* Checks T for any "bare" parameter packs, which have not yet been
3859 expanded, and issues an error if any are found. This operation can
3860 only be done on full expressions or types (e.g., an expression
3861 statement, "if" condition, etc.), because we could have expressions like:
3863 foo(f(g(h(args)))...)
3865 where "args" is a parameter pack. check_for_bare_parameter_packs
3866 should not be called for the subexpressions args, h(args),
3867 g(h(args)), or f(g(h(args))), because we would produce erroneous
3868 error messages.
3870 Returns TRUE and emits an error if there were bare parameter packs,
3871 returns FALSE otherwise. */
3872 bool
3874 {
3891 {
3895 {
3906 else
3911 else
3915 }
3918 }
3921 }
3923 /* Expand any parameter packs that occur in the template arguments in
3924 ARGS. */
3925 tree
3927 {
3936 /* First, determine if we need to expand anything, and the number of
3937 slots we'll need. */
3939 {
3944 {
3948 else
3950 }
3951 else
3952 {
3954 num_result_args++;
3955 }
3956 }
3958 /* If no expansion is necessary, we're done. */
3962 /* Expand arguments. */
3965 non_default_args_count =
3968 {
3971 {
3978 }
3979 else
3980 {
3983 }
3984 }
3988 }
3990 /* Checks if DECL shadows a template parameter.
3992 [temp.local]: A template-parameter shall not be redeclared within its
3993 scope (including nested scopes).
3995 Emits an error and returns TRUE if the DECL shadows a parameter,
3996 returns FALSE otherwise. */
3998 bool
4000 {
4001 tree olddecl;
4003 /* If we're not in a template, we can't possibly shadow a template
4004 parameter. */
4008 /* Figure out what we're shadowing. */
4012 /* If there's no previous binding for this name, we're not shadowing
4013 anything, let alone a template parameter. */
4017 /* If we're not shadowing a template parameter, we're done. Note
4018 that OLDDECL might be an OVERLOAD (or perhaps even an
4019 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4020 node. */
4024 /* We check for decl != olddecl to avoid bogus errors for using a
4025 name inside a class. We check TPFI to avoid duplicate errors for
4026 inline member templates. */
4032 /* Don't complain about the injected class name, as we've already
4033 complained about the class itself. */
4040 else
4045 }
4047 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4048 ORIG_LEVEL, DECL, and TYPE. */
4050 static tree
4054 tree decl,
4055 tree type)
4056 {
4067 }
4069 /* Find the canonical type parameter for the given template type
4070 parameter. Returns the canonical type parameter, which may be TYPE
4071 if no such parameter existed. */
4073 static tree
4075 {
4076 tree list;
4090 else
4091 {
4095 }
4096 }
4098 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4099 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4100 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4101 new one is created. */
4103 static tree
4105 tsubst_flags_t complain)
4106 {
4111 {
4130 /* Template template parameters need this. */
4132 {
4139 }
4140 }
4143 }
4145 /* Process information from new template parameter PARM and append it
4146 to the LIST being built. This new parameter is a non-type
4147 parameter iff IS_NON_TYPE is true. This new parameter is a
4148 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4149 is in PARM_LOC. */
4151 tree
4154 {
4163 {
4167 {
4171 else
4173 }
4176 }
4179 {
4185 {
4186 /* [temp.param]
4188 The top-level cv-qualifiers on the template-parameter are
4189 ignored when determining its type. */
4194 && !is_parameter_pack
4195 /* If we're in a nested template parameter list, the template
4196 template parameter could be a parameter pack. */
4198 {
4199 /* This template parameter is not a parameter pack, but it
4200 should be. Complain about "bare" parameter packs. */
4203 /* Recover by calling this a parameter pack. */
4205 }
4206 }
4208 /* A template parameter is not modifiable. */
4217 processing_template_decl,
4222 }
4223 else
4224 {
4225 tree t;
4229 {
4231 /* This is for distinguishing between real templates and template
4232 template parameters */
4236 }
4237 else
4238 {
4240 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4243 }
4250 processing_template_decl,
4254 }
4258 /* Build requirements for the type/template parameter.
4259 This must be done after SET_DECL_TEMPLATE_PARM_P or
4260 process_template_parm could fail. */
4265 /* Build the parameter node linking the parameter declaration,
4266 its default argument (if any), and its constraints (if any). */
4271 }
4273 /* The end of a template parameter list has been reached. Process the
4274 tree list into a parameter vector, converting each parameter into a more
4275 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4276 as PARM_DECLs. */
4278 tree
4280 {
4285 /* Pop the dummy parameter level and add the real one. */
4288 current_template_parms
4293 {
4297 }
4302 }
4304 // Explicitly indicate the end of the template parameter list. We assume
4305 // that the current template parameters have been constructed and/or
4306 // managed explicitly, as when creating new template template parameters
4307 // from a shorthand constraint.
4308 void
4310 {
4312 }
4314 /* end_template_decl is called after a template declaration is seen. */
4316 void
4318 {
4324 /* This matches the pushlevel in begin_template_parm_list. */
4329 }
4331 /* Takes a TREE_LIST representing a template parameter and convert it
4332 into an argument suitable to be passed to the type substitution
4333 functions. Note that If the TREE_LIST contains an error_mark
4334 node, the returned argument is error_mark_node. */
4336 tree
4338 {
4351 {
4355 {
4356 /* Turn this argument into a TYPE_ARGUMENT_PACK
4357 with a single element, which expands T. */
4366 }
4367 }
4368 else
4369 {
4373 {
4374 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4375 with a single element, which expands T. */
4385 }
4386 else
4388 }
4390 }
4392 /* Given a single level of template parameters (a TREE_VEC), return it
4393 as a set of template arguments. */
4395 static tree
4397 {
4407 }
4409 /* Given a set of template parameters, return them as a set of template
4410 arguments. The template parameters are represented as a TREE_VEC, in
4411 the form documented in cp-tree.h for template arguments. */
4413 static tree
4415 {
4416 tree header;
4421 /* If there is only one level of template parameters, we do not
4422 create a TREE_VEC of TREE_VECs. Instead, we return a single
4423 TREE_VEC containing the arguments. */
4428 {
4433 else
4435 }
4438 }
4440 /* Within the declaration of a template, return the currently active
4441 template parameters as an argument TREE_VEC. */
4443 static tree
4445 {
4447 }
4449 /* Update the declared TYPE by doing any lookups which were thought to be
4450 dependent, but are not now that we know the SCOPE of the declarator. */
4452 tree
4454 {
4465 /* Don't bother building up the args in this case. */
4467 {
4468 /* tsubst in the args corresponding to the template parameters,
4469 including auto if present. Most things will be unchanged, but
4470 make_typename_type and tsubst_qualified_id will resolve
4471 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4474 tree pushed;
4476 {
4480 }
4485 }
4491 {
4494 else
4496 }
4498 }
4500 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4501 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4502 the new template is a member template. */
4504 tree
4506 {
4514 }
4516 struct template_parm_data
4517 {
4518 /* The level of the template parameters we are currently
4519 processing. */
4522 /* The index of the specialization argument we are currently
4523 processing. */
4526 /* An array whose size is the number of template parameters. The
4527 elements are nonzero if the parameter has been used in any one
4528 of the arguments processed so far. */
4531 /* An array whose size is the number of template arguments. The
4532 elements are nonzero if the argument makes use of template
4533 parameters of this level. */
4535 };
4537 /* Subroutine of push_template_decl used to see if each template
4538 parameter in a partial specialization is used in the explicit
4539 argument list. If T is of the LEVEL given in DATA (which is
4540 treated as a template_parm_data*), then DATA->PARMS is marked
4541 appropriately. */
4543 static int
4545 {
4553 {
4556 }
4558 /* In C++17 the type of a non-type argument is a deduced context. */
4563 data,
4564 NULL,
4567 /* Return zero so that for_each_template_parm will continue the
4568 traversal of the tree; we want to mark *every* template parm. */
4570 }
4572 /* Process the partial specialization DECL. */
4574 static tree
4576 {
4583 tree inner_parms;
4584 tree inst;
4594 /* A concept cannot be specialized. */
4596 {
4599 }
4604 /* We check that each of the template parameters given in the
4605 partial specialization is used in the argument list to the
4606 specialization. For example:
4608 template <class T> struct S;
4609 template <class T> struct S<T*>;
4611 The second declaration is OK because `T*' uses the template
4612 parameter T, whereas
4614 template <class T> struct S<int>;
4616 is no good. Even trickier is:
4618 template <class T>
4619 struct S1
4620 {
4621 template <class U>
4622 struct S2;
4623 template <class U>
4624 struct S2<T>;
4625 };
4627 The S2<T> declaration is actually invalid; it is a
4628 full-specialization. Of course,
4630 template <class U>
4631 struct S2<T (*)(U)>;
4633 or some such would have been OK. */
4641 {
4646 NULL,
4648 }
4651 {
4652 /* One of the template parms was not used in a deduced context in the
4653 specialization. */
4655 {
4659 }
4663 }
4668 /* [temp.class.spec]
4670 The argument list of the specialization shall not be identical to
4671 the implicit argument list of the primary template. */
4672 tree main_args
4675 && (!flag_concepts
4678 {
4682 else
4686 }
4688 /* A partial specialization that replaces multiple parameters of the
4689 primary template with a pack expansion is less specialized for those
4690 parameters. */
4692 {
4694 "primary template because it replaces multiple parameters "
4697 /* Avoid crash in process_partial_specialization. */
4699 }
4701 /* If we aren't in a dependent class, we can actually try deduction. */
4703 /* FIXME we should be able to handle a partial specialization of a
4704 partial instantiation, but currently we can't (c++/41727). */
4707 {
4711 maintmpl);
4712 }
4714 /* [temp.class.spec]
4716 A partially specialized non-type argument expression shall not
4717 involve template parameters of the partial specialization except
4718 when the argument expression is a simple identifier.
4720 The type of a template parameter corresponding to a specialized
4721 non-type argument shall not be dependent on a parameter of the
4722 specialization.
4724 Also, we verify that pack expansions only occur at the
4725 end of the argument list. */
4729 {
4736 {
4737 /* Extract the arguments from the argument pack. We'll be
4738 iterating over these in the following loop. */
4741 }
4744 {
4746 /* Get the Jth argument in the parameter pack. */
4750 {
4751 /* Pack expansions must come at the end of the
4752 argument list. */
4755 {
4759 else
4762 }
4763 }
4766 /* We only care about the pattern. */
4772 /* This next two lines are the `argument expression is not just a
4773 simple identifier' condition and also the `specialized
4774 non-type argument' bit. */
4778 {
4782 arg);
4783 else
4784 {
4785 /* Look at the corresponding template parameter,
4786 marking which template parameters its type depends
4787 upon. */
4791 {
4792 /* We haven't yet initialized TPD2. Do so now. */
4794 /* The number of parameters here is the number in the
4795 main template, which, as checked in the assertion
4796 above, is NARGS. */
4800 }
4802 /* Mark the template parameters. But this time, we're
4803 looking for the template parameters of the main
4804 template, not in the specialization. */
4811 NULL,
4815 {
4816 /* The type depended on some template parameters.
4817 If they are fully specialized in the
4818 specialization, that's OK. */
4827 "type %qT of template argument %qE depends "
4829 "type %qT of template argument %qE depends "
4831 type,
4832 arg);
4833 }
4834 }
4835 }
4836 }
4837 }
4839 /* We should only get here once. */
4843 // Build the template decl.
4852 /* Give template template parms a DECL_CONTEXT of the template
4853 for which they are a parameter. */
4855 {
4859 }
4862 /* We didn't register this in check_explicit_specialization so we could
4863 wait until the constraints were set. */
4865 else
4875 {
4881 {
4889 "declaration of %qD ambiguates earlier template "
4893 "partial specialization of %qD after instantiation "
4895 }
4896 }
4899 }
4901 /* PARM is a template parameter of some form; return the corresponding
4902 TEMPLATE_PARM_INDEX. */
4904 static tree
4906 {
4919 }
4921 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4922 parameter packs used by the template parameter PARM. */
4924 static void
4926 {
4927 /* A type parm can't refer to another parm. */
4931 {
4935 }
4942 }
4944 /* PARM is a template parameter pack. Return any parameter packs used in
4945 its type or the type of any of its template parameters. If there are
4946 any such packs, it will be instantiated into a fixed template parameter
4947 list by partial instantiation rather than be fully deduced. */
4949 tree
4951 {
4952 /* This can only be true in a member template. */
4955 /* This can only be true for a parameter pack. */
4958 /* A type parm can't refer to another parm. */
4972 }
4974 /* Check that a template declaration's use of default arguments and
4975 parameter packs is not invalid. Here, PARMS are the template
4976 parameters. IS_PRIMARY is true if DECL is the thing declared by
4977 a primary template. IS_PARTIAL is true if DECL is a partial
4978 specialization.
4980 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4981 declaration (but not a definition); 1 indicates a declaration, 2
4982 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4983 emitted for extraneous default arguments.
4985 Returns TRUE if there were no errors found, FALSE otherwise. */
4987 bool
4990 {
4993 tree parm_level;
4996 /* [temp.param]
4998 A default template-argument shall not be specified in a
4999 function template declaration or a function template definition, nor
5000 in the template-parameter-list of the definition of a member of a
5001 class template. */
5005 /* You can't have a function template declaration in a local
5006 scope, nor you can you define a member of a class template in a
5007 local scope. */
5015 /* A lambda doesn't have an explicit declaration; don't complain
5016 about the parms of the enclosing class. */
5023 /* If this is either a friend defined in the scope of the class
5024 or a member function. */
5030 /* And, if it was a member function, it really was defined in
5031 the scope of the class. */
5034 /* We already checked these parameters when the template was
5035 declared, so there's no need to do it again now. This function
5036 was defined in class scope, but we're processing its body now
5037 that the class is complete. */
5040 /* Core issue 226 (C++0x only): the following only applies to class
5041 templates. */
5044 {
5045 /* [temp.param]
5047 If a template-parameter has a default template-argument, all
5048 subsequent template-parameters shall have a default
5049 template-argument supplied. */
5051 {
5058 {
5068 {
5070 /* For better subsequent error-recovery, we indicate that
5071 there should have been a default argument. */
5074 }
5076 && !is_friend_decl
5077 /* Don't complain about an enclosing partial
5078 specialization. */
5083 /* A fixed parameter pack will be partially
5084 instantiated into a fixed length list. */
5086 {
5087 /* A primary class template can only have one
5088 parameter pack, at the end of the template
5089 parameter list. */
5097 }
5098 }
5099 }
5100 }
5103 || is_partial
5104 || !is_primary
5106 /* For an ordinary class template, default template arguments are
5107 allowed at the innermost level, e.g.:
5108 template <class T = int>
5109 struct S {};
5110 but, in a partial specialization, they're not allowed even
5111 there, as we have in [temp.class.spec]:
5113 The template parameter list of a specialization shall not
5114 contain default template argument values.
5116 So, for a partial specialization, or for a function template
5117 (in C++98/C++03), we look at all of them. */
5118 ;
5119 else
5120 /* But, for a primary class template that is not a partial
5121 specialization we look at all template parameters except the
5122 innermost ones. */
5125 /* Figure out what error message to issue. */
5140 else
5141 /* Per [temp.param]/9, "A default template-argument shall not be
5142 specified in the template-parameter-lists of the definition of
5143 a member of a class template that appears outside of the member's
5144 class.", thus if we aren't handling a member of a class template
5145 there is no need to examine the parameters. */
5149 /* If we're inside a class definition, there's no need to
5150 examine the parameters to the class itself. On the one
5151 hand, they will be checked when the class is defined, and,
5152 on the other, default arguments are valid in things like:
5153 template <class T = double>
5154 struct S { template <class U> void f(U); };
5155 Here the default argument for `S' has no bearing on the
5156 declaration of `f'. */
5158 else
5159 /* Check everything. */
5165 {
5172 {
5177 {
5179 {
5186 }
5188 /* Clear out the default argument so that we are not
5189 confused later. */
5191 }
5192 }
5194 /* At this point, if we're still interested in issuing messages,
5195 they must apply to classes surrounding the object declared. */
5199 }
5202 }
5204 /* Worker for push_template_decl_real, called via
5205 for_each_template_parm. DATA is really an int, indicating the
5206 level of the parameters we are interested in. If T is a template
5207 parameter of that level, return nonzero. */
5209 static int
5211 {
5217 else
5220 }
5222 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5223 DATA is really an int, indicating the innermost outer level of parameters.
5224 If T is a template parameter of that level or further out, return
5225 nonzero. */
5227 static int
5229 {
5235 else
5238 }
5240 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5241 parameters given by current_template_args, or reuses a
5242 previously existing one, if appropriate. Returns the DECL, or an
5243 equivalent one, if it is replaced via a call to duplicate_decls.
5245 If IS_FRIEND is true, DECL is a friend declaration. */
5247 tree
5249 {
5250 tree tmpl;
5251 tree args;
5252 tree info;
5253 tree ctx;
5257 /* True if the template is a member template, in the sense of
5258 [temp.mem]. */
5264 /* See if this is a partial specialization. */
5277 /* For a friend, we want the context of the friend function, not
5278 the type of which it is a friend. */
5282 /* In the case of a virtual function, we want the class in which
5283 it is defined. */
5285 else
5286 /* Otherwise, if we're currently defining some class, the DECL
5287 is assumed to be a member of the class. */
5296 /* See if this is a primary template. */
5299 /* A friend template that specifies a class context, i.e.
5300 template <typename T> friend void A<T>::f();
5301 is not primary. */
5306 else
5310 {
5317 {
5320 }
5322 {
5324 {
5327 }
5329 {
5330 /* [temp.mem]
5332 A destructor shall not be a member template. */
5335 }
5342 {
5343 /* [basic.stc.dynamic.allocation]
5345 An allocation function can be a function
5346 template. ... Template allocation functions shall
5347 have two or more parameters. */
5350 }
5351 }
5354 {
5355 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5358 {
5364 }
5365 }
5368 /* alias-declaration */
5372 else
5373 {
5376 }
5377 }
5379 /* Check to see that the rules regarding the use of default
5380 arguments are not being violated. */
5384 /* Ensure that there are no parameter packs in the type of this
5385 declaration that have not been expanded. */
5387 {
5388 /* Check each of the arguments individually to see if there are
5389 any bare parameter packs. */
5395 {
5398 {
5399 /* This is a PARM_DECL that contains unexpanded parameter
5400 packs. We have already complained about this in the
5401 check_for_bare_parameter_packs call, so just replace
5402 these types with ERROR_MARK_NODE. */
5405 }
5409 }
5411 /* Check for bare parameter packs in the return type and the
5412 exception specifiers. */
5414 /* Errors were already issued, set return type to int
5415 as the frontend doesn't expect error_mark_node as
5416 the return type. */
5420 }
5425 {
5428 }
5441 {
5446 /* If DECL is a TYPE_DECL for a class-template, then there won't
5447 be DECL_LANG_SPECIFIC. The information equivalent to
5448 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5452 {
5453 /* Since a template declaration already existed for this
5454 class-type, we must be redeclaring it here. Make sure
5455 that the redeclaration is valid. */
5457 current_template_parms,
5459 /* We don't need to create a new TEMPLATE_DECL; just use the
5460 one we already had. */
5462 }
5463 else
5464 {
5466 member_template_p);
5471 {
5472 /* A specialization of a member template of a template
5473 class. */
5477 }
5478 }
5479 }
5480 else
5481 {
5487 {
5490 }
5498 {
5499 tree new_tmpl;
5501 /* The declaration is a specialization of a member
5502 template, declared outside the class. Therefore, the
5503 innermost template arguments will be NULL, so we
5504 replace them with the arguments determined by the
5505 earlier call to check_explicit_specialization. */
5508 new_tmpl
5510 member_template_p);
5520 args,
5523 }
5525 /* Make sure the template headers we got make sense. */
5530 {
5535 }
5536 else
5538 {
5543 {
5547 else
5551 /* Avoid crash in import_export_decl. */
5554 }
5559 /* Can happen in erroneous input. */
5561 else
5563 }
5565 /* Check that the parms are used in the appropriate qualifying scopes
5566 in the declarator. */
5570 {
5576 /* Avoid crash in import_export_decl. */
5579 }
5580 }
5585 /* Push template declarations for global functions and types. Note
5586 that we do not try to push a global template friend declared in a
5587 template class; such a thing may well depend on the template
5588 parameters of the class. */
5591 {
5596 /* Hide template friend classes that haven't been declared yet. */
5598 {
5601 }
5602 }
5605 {
5611 {
5614 /* It is a conversion operator. See if the type converted to
5615 depends on innermost template operands. */
5618 depth))
5620 }
5622 /* Give template template parms a DECL_CONTEXT of the template
5623 for which they are a parameter. */
5626 {
5630 }
5636 }
5638 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5639 back to its most general template. If TMPL is a specialization,
5640 ARGS may only have the innermost set of arguments. Add the missing
5641 argument levels if necessary. */
5649 else
5650 {
5655 }
5658 && !is_friend
5661 /* Set DECL_COMDAT on template instantiations; if we force
5662 them to be emitted by explicit instantiation or -frepo,
5663 mark_needed will tell cgraph to do the right thing. */
5667 }
5669 tree
5671 {
5673 }
5675 /* FN is an inheriting constructor that inherits from the constructor
5676 template INHERITED; turn FN into a constructor template with a matching
5677 template header. */
5679 tree
5681 {
5682 tree inner_parms
5685 tree parms
5696 }
5698 /* Called when a class template TYPE is redeclared with the indicated
5699 template PARMS, e.g.:
5701 template <class T> struct S;
5702 template <class T> struct S {}; */
5704 bool
5706 {
5707 tree tmpl;
5708 tree tmpl_parms;
5712 {
5715 }
5719 /* The type is nested in some template class. Nothing to worry
5720 about here; there are no new template parameters for the nested
5721 type. */
5725 {
5727 tmpl);
5729 }
5735 {
5745 }
5748 {
5749 tree tmpl_parm;
5750 tree parm;
5751 tree tmpl_default;
5752 tree parm_default;
5766 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5767 TEMPLATE_DECL. */
5777 {
5781 }
5784 {
5785 /* We have in [temp.param]:
5787 A template-parameter may not be given default arguments
5788 by two different declarations in the same scope. */
5793 }
5796 /* Update the previous template parameters (which are the ones
5797 that will really count) with the new default value. */
5800 /* Update the new parameters, too; they'll be used as the
5801 parameters for any members. */
5804 /* Give each template template parm in this redeclaration a
5805 DECL_CONTEXT of the template for which they are a parameter. */
5807 {
5810 }
5814 }
5816 // Cannot redeclare a class template with a different set of constraints.
5818 {
5823 }
5826 }
5828 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5829 to be used when the caller has already checked
5830 (processing_template_decl
5831 && !instantiation_dependent_expression_p (expr)
5832 && potential_constant_expression (expr))
5833 and cleared processing_template_decl. */
5835 tree
5837 {
5840 complain,
5844 }
5846 /* Simplify EXPR if it is a non-dependent expression. Returns the
5847 (possibly simplified) expression. */
5849 tree
5851 {
5855 /* If we're in a template, but EXPR isn't value dependent, simplify
5856 it. We're supposed to treat:
5858 template <typename T> void f(T[1 + 1]);
5859 template <typename T> void f(T[2]);
5861 as two declarations of the same function, for example. */
5864 {
5865 processing_template_decl_sentinel s;
5867 }
5869 }
5871 tree
5873 {
5875 }
5877 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5878 an uninstantiated expression. */
5880 tree
5882 {
5886 {
5889 else
5890 {
5891 processing_template_decl_sentinel s;
5893 }
5894 }
5896 }
5898 /* True iff T is a specialization of a variable template. */
5900 bool
5902 {
5907 }
5909 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5910 template declaration, or a TYPE_DECL for an alias declaration. */
5912 bool
5914 {
5922 }
5924 /* Return TRUE iff T is a specialization of an alias template. */
5926 bool
5928 {
5929 /* It's an alias template specialization if it's an alias and its
5930 TYPE_NAME is a specialization of a primary template. */
5936 }
5938 /* An alias template is complex from a SFINAE perspective if a template-id
5939 using that alias can be ill-formed when the expansion is not, as with
5940 the void_t template. We determine this by checking whether the
5941 expansion for the alias template uses all its template parameters. */
5943 struct uses_all_template_parms_data
5944 {
5947 };
5949 static int
5951 {
5959 }
5961 static bool
5963 {
5978 }
5980 /* Return TRUE iff T is a specialization of a complex alias template with
5981 dependent template-arguments. */
5983 bool
5985 {
5998 }
6000 /* Return the number of innermost template parameters in TMPL. */
6002 static int
6004 {
6007 }
6009 /* Return either TMPL or another template that it is equivalent to under DR
6010 1286: An alias that just changes the name of a template is equivalent to
6011 the other template. */
6013 static tree
6015 {
6018 {
6019 /* Determine if the alias is equivalent to an underlying template. */
6031 tree alias_args = INNERMOST_TEMPLATE_ARGS
6036 /* Alias is equivalent. Strip it and repeat. */
6038 }
6041 }
6043 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6044 must be a reference-to-function or a pointer-to-function type, as specified
6045 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6046 and check that the resulting function has external linkage. */
6048 static tree
6050 tsubst_flags_t complain)
6051 {
6054 linkage_kind linkage;
6069 /* [temp.arg.nontype]/1
6071 A template-argument for a non-type, non-template template-parameter
6072 shall be one of:
6073 [...]
6074 -- the address of an object or function with external [C++11: or
6075 internal] linkage. */
6078 {
6080 {
6086 else
6089 }
6091 }
6095 {
6097 {
6102 else
6106 }
6108 }
6110 accept:
6117 }
6119 /* Subroutine of convert_nontype_argument.
6120 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6121 Emit an error otherwise. */
6123 static bool
6125 tsubst_flags_t complain)
6126 {
6143 {
6148 else
6150 }
6152 }
6154 /* Returns TRUE iff the address of OP is value-dependent.
6156 14.6.2.4 [temp.dep.temp]:
6157 A non-integral non-type template-argument is dependent if its type is
6158 dependent or it has either of the following forms
6159 qualified-id
6160 & qualified-id
6161 and contains a nested-name-specifier which specifies a class-name that
6162 names a dependent type.
6164 We generalize this to just say that the address of a member of a
6165 dependent class is value-dependent; the above doesn't cover the
6166 address of a static data member named with an unqualified-id. */
6168 static bool
6170 {
6171 /* We could use get_inner_reference here, but there's no need;
6172 this is only relevant for template non-type arguments, which
6173 can only be expressed as &id-expression. */
6175 {
6179 }
6182 }
6184 /* The next set of functions are used for providing helpful explanatory
6185 diagnostics for failed overload resolution. Their messages should be
6186 indented by two spaces for consistency with the messages in
6187 call.c */
6189 static int
6191 {
6193 }
6195 /* Other failure functions should call this one, to provide a single function
6196 for setting a breakpoint on. */
6198 static int
6200 {
6202 }
6204 static int
6206 {
6211 }
6213 static int
6215 {
6221 }
6223 static int
6225 {
6229 }
6231 static int
6233 {
6236 " template parameter %qD is not a parameter pack, but "
6240 }
6242 static int
6244 {
6247 " template argument %qE does not match "
6251 }
6253 static int
6255 {
6259 }
6261 static int
6263 {
6269 }
6271 static int
6273 {
6275 {
6280 else
6282 " deduced conflicting values for non-type parameter "
6284 }
6286 }
6288 static int
6290 {
6293 " variable-sized array type %qT is not "
6295 arg);
6297 }
6299 static int
6301 {
6305 arg);
6307 }
6309 static int
6311 {
6313 {
6319 else
6324 }
6326 }
6328 static int
6330 {
6332 }
6334 static int
6337 {
6339 }
6341 static int
6344 {
6350 }
6352 static int
6355 {
6358 {
6366 }
6368 }
6370 static int
6372 {
6375 " template parameters of a template template argument are "
6378 }
6380 static int
6382 {
6388 }
6390 static int
6392 {
6397 }
6399 static int
6401 {
6405 arg);
6407 }
6409 /* Attempt to convert the non-type template parameter EXPR to the
6410 indicated TYPE. If the conversion is successful, return the
6411 converted value. If the conversion is unsuccessful, return
6412 NULL_TREE if we issued an error message, or error_mark_node if we
6413 did not. We issue error messages for out-and-out bad template
6414 parameters, but not simply because the conversion failed, since we
6415 might be just trying to do argument deduction. Both TYPE and EXPR
6416 must be non-dependent.
6418 The conversion follows the special rules described in
6419 [temp.arg.nontype], and it is much more strict than an implicit
6420 conversion.
6422 This function is called twice for each template argument (see
6423 lookup_template_class for a more accurate description of this
6424 problem). This means that we need to handle expressions which
6425 are not valid in a C++ source, but can be created from the
6426 first call (for instance, casts to perform conversions). These
6427 hacks can go away after we fix the double coercion problem. */
6429 static tree
6431 {
6432 tree expr_type;
6436 /* Detect immediately string literals as invalid non-type argument.
6437 This special-case is not needed for correctness (we would easily
6438 catch this later), but only to provide better diagnostic for this
6439 common user mistake. As suggested by DR 100, we do not mention
6440 linkage issues in the diagnostic as this is not the point. */
6441 /* FIXME we're making this OK. */
6443 {
6449 }
6451 /* Add the ADDR_EXPR now for the benefit of
6452 value_dependent_expression_p. */
6455 {
6459 }
6461 /* If we are in a template, EXPR may be non-dependent, but still
6462 have a syntactic, rather than semantic, form. For example, EXPR
6463 might be a SCOPE_REF, rather than the VAR_DECL to which the
6464 SCOPE_REF refers. Preserving the qualifying scope is necessary
6465 so that access checking can be performed when the template is
6466 instantiated -- but here we need the resolved form so that we can
6467 convert the argument. */
6480 else
6483 /* If the argument is non-dependent, perform any conversions in
6484 non-dependent context as well. */
6492 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6493 to a non-type argument of "nullptr". */
6497 /* In C++11, integral or enumeration non-type template arguments can be
6498 arbitrary constant expressions. Pointer and pointer to
6499 member arguments can be general constant expressions that evaluate
6500 to a null value, but otherwise still need to be of a specific form. */
6502 {
6504 /* A PTRMEM_CST is already constant, and a valid template
6505 argument for a parameter of pointer to member type, we just want
6506 to leave it in that form rather than lower it to a
6510 {
6511 /* C++17: A template-argument for a non-type template-parameter shall
6512 be a converted constant expression (8.20) of the type of the
6513 template-parameter. */
6519 }
6521 {
6526 }
6527 }
6529 /* HACK: Due to double coercion, we can get a
6530 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6531 which is the tree that we built on the first call (see
6532 below when coercing to reference to object or to reference to
6533 function). We just strip everything and get to the arg.
6534 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6535 for examples. */
6537 {
6543 {
6544 /* ??? Maybe we could use convert_from_reference here, but we
6545 would need to relax its constraints because the NOP_EXPR
6546 could actually change the type to something more cv-qualified,
6547 and this is not folded by convert_from_reference. */
6552 && (same_type_ignoring_top_level_qualifiers_p
6555 {
6558 }
6559 }
6560 }
6562 /* [temp.arg.nontype]/5, bullet 1
6564 For a non-type template-parameter of integral or enumeration type,
6565 integral promotions (_conv.prom_) and integral conversions
6566 (_conv.integral_) are applied. */
6568 {
6570 {
6575 }
6580 /* Notice that there are constant expressions like '4 % 0' which
6581 do not fold into integer constants. */
6584 {
6586 {
6596 /* else cxx_constant_value complained but gave us
6597 a real constant, so go ahead. */
6599 }
6600 else
6602 }
6604 /* Avoid typedef problems. */
6607 }
6608 /* [temp.arg.nontype]/5, bullet 2
6610 For a non-type template-parameter of type pointer to object,
6611 qualification conversions (_conv.qual_) and the array-to-pointer
6612 conversion (_conv.array_) are applied. */
6614 {
6617 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6618 decay_conversion or an explicit cast. If it's a problematic cast,
6619 we'll complain about it below. */
6621 {
6626 {
6629 }
6630 }
6632 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6634 A template-argument for a non-type, non-template template-parameter
6635 shall be one of: [...]
6637 -- the name of a non-type template-parameter;
6638 -- the address of an object or function with external linkage, [...]
6639 expressed as "& id-expression" where the & is optional if the name
6640 refers to a function or array, or if the corresponding
6641 template-parameter is a reference.
6643 Here, we do not care about functions, as they are invalid anyway
6644 for a parameter of type pointer-to-object. */
6647 /* Non-type template parameters are OK. */
6648 ;
6652 {
6654 {
6657 "because %qD is a variable, not the address of "
6660 }
6662 {
6668 }
6669 /* Other values, like integer constants, might be valid
6670 non-type arguments of some other type. */
6672 }
6673 else
6674 {
6678 {
6683 }
6685 {
6691 }
6694 {
6699 }
6700 /* C++17: For a non-type template-parameter of reference or pointer
6701 type, the value of the constant expression shall not refer to (or
6702 for a pointer type, shall not be the address of):
6703 * a subobject (4.5),
6704 * a temporary object (15.2),
6705 * a string literal (5.13.5),
6706 * the result of a typeid expression (8.2.8), or
6707 * a predefined __func__ variable (11.4.1). */
6709 {
6712 decl);
6714 }
6718 {
6723 }
6725 {
6729 decl);
6731 }
6732 }
6739 }
6740 /* [temp.arg.nontype]/5, bullet 3
6742 For a non-type template-parameter of type reference to object, no
6743 conversions apply. The type referred to by the reference may be more
6744 cv-qualified than the (otherwise identical) type of the
6745 template-argument. The template-parameter is bound directly to the
6746 template-argument, which must be an lvalue. */
6748 {
6750 expr_type))
6754 {
6759 }
6762 {
6767 }
6769 /* [temp.arg.nontype]/1
6771 A template-argument for a non-type, non-template template-parameter
6772 shall be one of: [...]
6774 -- the address of an object or function with external linkage. */
6777 {
6780 {
6783 "because a reference variable does not have a constant "
6786 }
6787 }
6791 /* OK, dependent reference. We don't want to ask whether a DECL is
6793 else
6794 {
6796 {
6802 }
6804 /* DR 1155 allows internal linkage in C++11 and up. */
6807 {
6813 }
6816 }
6820 }
6821 /* [temp.arg.nontype]/5, bullet 4
6823 For a non-type template-parameter of type pointer to function, only
6824 the function-to-pointer conversion (_conv.func_) is applied. If the
6825 template-argument represents a set of overloaded functions (or a
6826 pointer to such), the matching function is selected from the set
6827 (_over.over_). */
6829 {
6830 /* If the argument is a template-id, we might not have enough
6831 context information to decay the pointer. */
6833 {
6837 }
6840 /* Null pointer values are OK in C++11. */
6846 }
6847 /* [temp.arg.nontype]/5, bullet 5
6849 For a non-type template-parameter of type reference to function, no
6850 conversions apply. If the template-argument represents a set of
6851 overloaded functions, the matching function is selected from the set
6852 (_over.over_). */
6854 {
6856 {
6858 {
6863 }
6865 }
6870 }
6871 /* [temp.arg.nontype]/5, bullet 6
6873 For a non-type template-parameter of type pointer to member function,
6874 no conversions apply. If the template-argument represents a set of
6875 overloaded member functions, the matching member function is selected
6876 from the set (_over.over_). */
6878 {
6883 /* [temp.arg.nontype] bullet 1 says the pointer to member
6884 expression must be a pointer-to-member constant. */
6889 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6890 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6893 }
6894 /* [temp.arg.nontype]/5, bullet 7
6896 For a non-type template-parameter of type pointer to data member,
6897 qualification conversions (_conv.qual_) are applied. */
6899 {
6900 /* [temp.arg.nontype] bullet 1 says the pointer to member
6901 expression must be a pointer-to-member constant. */
6909 }
6911 {
6913 {
6918 }
6920 }
6921 /* A template non-type parameter must be one of the above. */
6922 else
6925 /* Sanity check: did we actually convert the argument to the
6926 right type? */
6930 }
6932 /* Subroutine of coerce_template_template_parms, which returns 1 if
6933 PARM_PARM and ARG_PARM match using the rule for the template
6934 parameters of template template parameters. Both PARM and ARG are
6935 template parameters; the rest of the arguments are the same as for
6936 coerce_template_template_parms.
6937 */
6938 static int
6940 tree arg,
6941 tsubst_flags_t complain,
6942 tree in_decl,
6943 tree outer_args)
6944 {
6953 {
6955 /* We encounter instantiations of templates like
6956 template <template <template <class> class> class TT>
6957 class C; */
6958 {
6965 }
6966 /* Fall through. */
6971 /* Argument is a parameter pack but parameter is not. */
6976 /* The tsubst call is used to handle cases such as
6978 template <int> class C {};
6979 template <class T, template <T> class TT> class D {};
6980 D<int, C> d;
6982 i.e. the parameter list of TT depends on earlier parameters. */
6984 {
6989 }
6993 /* Argument is a parameter pack but parameter is not. */
7000 }
7003 }
7005 /* Coerce template argument list ARGLIST for use with template
7006 template-parameter TEMPL. */
7008 static tree
7010 tsubst_flags_t complain)
7011 {
7012 /* Consider an example where a template template parameter declared as
7014 template <class T, class U = std::allocator<T> > class TT
7016 The template parameter level of T and U are one level larger than
7017 of TT. To proper process the default argument of U, say when an
7018 instantiation `TT<int>' is seen, we need to build the full
7019 arguments containing {int} as the innermost level. Outer levels,
7020 available when not appearing as default template argument, can be
7021 obtained from the arguments of the enclosing template.
7023 Suppose that TT is later substituted with std::vector. The above
7024 instantiation is `TT<int, std::allocator<T> >' with TT at
7025 level 1, and T at level 2, while the template arguments at level 1
7026 becomes {std::vector} and the inner level 2 is {int}. */
7030 {
7032 /* We want arguments for the partial specialization, not arguments for
7033 the primary template. */
7035 else
7037 }
7039 {
7040 /* This is an argument of the current template, so we haven't set
7041 DECL_CONTEXT yet. */
7042 tree relevant_template_parms;
7044 /* Parameter levels that are greater than the level of the given
7045 template template parm are irrelevant. */
7052 }
7059 complain,
7062 }
7064 /* A cache of template template parameters with match-all default
7065 arguments. */
7067 static void
7069 {
7073 }
7074 static tree
7076 {
7081 }
7083 /* T is a bound template template-parameter. Copy its arguments into default
7084 arguments of the template template-parameter's template parameters. */
7086 static tree
7088 {
7111 {
7114 {
7117 }
7118 }
7122 }
7124 /* ARG is a bound potential template template-argument, and PARGS is a list
7125 of arguments for the corresponding template template-parameter. Adjust
7126 PARGS as appropriate for application to ARG's template, and if ARG is a
7127 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7128 arguments to the template template parameter. */
7130 static tree
7132 {
7136 {
7137 /* When comparing two template template-parameters in partial ordering,
7138 rewrite the one currently being used as an argument to have default
7139 arguments for all parameters. */
7145 }
7146 else
7147 {
7148 tree aparms
7153 }
7156 }
7158 /* Subroutine of unify for the case when PARM is a
7159 BOUND_TEMPLATE_TEMPLATE_PARM. */
7161 static int
7164 {
7168 /* The template template parm might be variadic and the argument
7169 not, so flatten both argument lists. */
7175 {
7176 /* In keeping with P0522R0, adjust P's template arguments
7177 to apply to A's template; then flatten it again. */
7180 }
7186 /* If the P0522 adjustment eliminated a pack expansion, deduce
7187 empty packs. */
7195 }
7197 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7198 template template parameters. Both PARM_PARMS and ARG_PARMS are
7199 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7200 or PARM_DECL.
7202 Consider the example:
7203 template <class T> class A;
7204 template<template <class U> class TT> class B;
7206 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7207 the parameters to A, and OUTER_ARGS contains A. */
7209 static int
7211 tree arg_parms,
7212 tsubst_flags_t complain,
7213 tree in_decl,
7214 tree outer_args)
7215 {
7227 {
7228 /* P0522R0: A template template-parameter P is at least as specialized as
7229 a template template-argument A if, given the following rewrite to two
7230 function templates, the function template corresponding to P is at
7231 least as specialized as the function template corresponding to A
7232 according to the partial ordering rules for function templates
7233 ([temp.func.order]). Given an invented class template X with the
7234 template parameter list of A (including default arguments):
7236 * Each of the two function templates has the same template parameters,
7237 respectively, as P or A.
7239 * Each function template has a single function parameter whose type is
7240 a specialization of X with template arguments corresponding to the
7241 template parameters from the respective function template where, for
7242 each template parameter PP in the template parameter list of the
7243 function template, a corresponding template argument AA is formed. If
7244 PP declares a parameter pack, then AA is the pack expansion
7245 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7247 If the rewrite produces an invalid type, then P is not at least as
7248 specialized as A. */
7250 /* So coerce P's args to apply to A's parms, and then deduce between A's
7251 args and the converted args. If that succeeds, A is at least as
7252 specialized as P, so they match.*/
7259 {
7265 }
7266 }
7268 /* Determine whether we have a parameter pack at the end of the
7269 template template parameter's template parameter list. */
7271 {
7278 {
7292 }
7293 }
7299 /* Check all of the template parameters except the parameter pack at
7300 the end (if any). */
7302 {
7311 outer_args))
7314 }
7317 {
7318 /* Check each of the template parameters in the template
7319 argument against the template parameter pack at the end of
7320 the template template parameter. */
7327 {
7334 outer_args))
7336 }
7337 }
7340 }
7342 /* Verifies that the deduced template arguments (in TARGS) for the
7343 template template parameters (in TPARMS) represent valid bindings,
7344 by comparing the template parameter list of each template argument
7345 to the template parameter list of its corresponding template
7346 template parameter, in accordance with DR150. This
7347 routine can only be called after all template arguments have been
7348 deduced. It will return TRUE if all of the template template
7349 parameter bindings are okay, FALSE otherwise. */
7350 bool
7352 {
7356 /* We're dealing with template parms in this process. */
7362 {
7367 {
7372 {
7373 /* Look inside the argument pack. */
7376 }
7379 {
7383 /* Extract the next argument from the argument
7384 pack. */
7388 /* Look at the pattern of the pack expansion. */
7391 /* Extract the template parameters from the template
7392 argument. */
7398 /* Verify that we can coerce the template template
7399 parameters from the template argument to the template
7400 parameter. This requires an exact match. */
7402 && !coerce_template_template_parms
7404 targ_parms,
7405 tf_none,
7406 tparm,
7407 targs))
7408 {
7411 }
7412 }
7413 }
7414 }
7416 out:
7420 }
7422 /* Since type attributes aren't mangled, we need to strip them from
7423 template type arguments. */
7425 static tree
7427 {
7437 }
7439 /* And from inside dependent non-type arguments like sizeof(Type). */
7441 static tree
7443 {
7453 }
7455 // A template declaration can be substituted for a constrained
7456 // template template parameter only when the argument is more
7457 // constrained than the parameter.
7458 static bool
7460 {
7463 /* For now, allow constrained template template arguments
7464 and unconstrained template template parameters. */
7470 // If the template parameter is constrained, we need to rewrite its
7471 // constraints in terms of the ARG's template parameters. This ensures
7472 // that all of the template parameter types will have the same depth.
7473 //
7474 // Note that this is only valid when coerce_template_template_parm is
7475 // true for the innermost template parameters of PARM and ARG. In other
7476 // words, because coercion is successful, this conversion will be valid.
7478 {
7485 }
7488 }
7490 // Convert a placeholder argument into a binding to the original
7491 // parameter. The original parameter is saved as the TREE_TYPE of
7492 // ARG.
7495 {
7498 }
7500 /* Convert the indicated template ARG as necessary to match the
7501 indicated template PARM. Returns the converted ARG, or
7502 error_mark_node if the conversion was unsuccessful. Error and
7503 warning messages are issued under control of COMPLAIN. This
7504 conversion is for the Ith parameter in the parameter list. ARGS is
7505 the full set of template arguments deduced so far. */
7507 static tree
7509 tree arg,
7510 tree args,
7511 tsubst_flags_t complain,
7513 tree in_decl)
7514 {
7515 tree orig_arg;
7516 tree val;
7522 /* Trivially convert placeholders. */
7531 {
7532 /* The template argument was the name of some
7533 member function. That's usually
7534 invalid, but static members are OK. In any
7535 case, grab the underlying fields/functions
7536 and issue an error later if required. */
7539 }
7547 /* When determining whether an argument pack expansion is a template,
7548 look at the pattern. */
7552 /* Deal with an injected-class-name used as a template template arg. */
7554 {
7557 {
7567 }
7568 }
7570 is_tmpl_type =
7586 {
7588 {
7592 }
7595 "to refer to a type member of a template parameter, "
7600 typename_type,
7601 complain);
7604 }
7606 {
7608 {
7610 {
7622 else
7625 }
7626 }
7628 }
7630 {
7632 {
7639 else
7642 }
7644 }
7647 /* We already did the appropriate conversion when packing args. */
7650 {
7652 {
7654 /* The number of argument required is not known yet.
7655 Just accept it for now. */
7657 else
7658 {
7660 tree argparm;
7662 /* Strip alias templates that are equivalent to another
7663 template. */
7669 args))
7670 {
7673 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7674 TEMPLATE_DECL. */
7676 {
7681 }
7682 }
7683 else
7684 {
7686 {
7693 }
7696 }
7698 // Check that the constraints are compatible before allowing the
7699 // substitution.
7702 {
7704 {
7710 }
7712 }
7713 }
7714 }
7715 else
7717 /* We only form one instance of each template specialization.
7718 Therefore, if we use a non-canonical variant (i.e., a
7719 typedef), any future messages referring to the type will use
7720 the typedef, which is confusing if those future uses do not
7721 themselves also use the typedef. */
7724 }
7725 else
7726 {
7730 {
7734 }
7735 else
7743 /* We used to call digest_init here. However, digest_init
7744 will report errors, which we don't want when complain
7745 is zero. More importantly, digest_init will try too
7746 hard to convert things: for example, `0' should not be
7747 converted to pointer type at this point according to
7748 the standard. Accepting this is not merely an
7749 extension, since deciding whether or not these
7750 conversions can occur is part of determining which
7751 function template to call, or whether a given explicit
7752 argument specification is valid. */
7754 else
7764 {
7765 /* Reject template arguments that are references to built-in
7766 functions with no library fallbacks. */
7775 }
7778 {
7779 /* Strip typedefs from the SCOPE_REF. */
7782 complain);
7785 }
7786 }
7789 }
7791 /* Coerces the remaining template arguments in INNER_ARGS (from
7792 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7793 Returns the coerced argument pack. PARM_IDX is the position of this
7794 parameter in the template parameter list. ARGS is the original
7795 template argument list. */
7796 static tree
7799 tree args,
7800 tree inner_args,
7802 tree new_args,
7804 tree in_decl,
7805 tsubst_flags_t complain)
7806 {
7809 tree packed_args;
7810 tree argument_pack;
7817 {
7818 /* When the template parameter is a non-type template parameter pack
7819 or template template parameter pack whose type or template
7820 parameters use parameter packs, we know exactly how many arguments
7821 we are looking for. Build a vector of the instantiated decls for
7822 these template parameters in PACKED_PARMS. */
7823 /* We can't use make_pack_expansion here because it would interpret a
7824 _DECL as a use rather than a declaration. */
7838 /* If we're doing a partial instantiation of a member template,
7839 verify that all of the types used for the non-type
7840 template parameter pack are, in fact, valid for non-type
7841 template parameters. */
7844 {
7847 {
7851 }
7852 /* We don't know how many args we have yet, just
7853 use the unconverted ones for now. */
7855 }
7858 }
7859 /* Check if we have a placeholder pack, which indicates we're
7860 in the context of a introduction list. In that case we want
7861 to match this pack to the single placeholder. */
7865 {
7868 }
7869 else
7872 /* Convert the remaining arguments, which will be a part of the
7873 parameter pack "parm". */
7876 {
7882 {
7883 /* Once we've packed as many args as we have types, stop. */
7887 /* We don't know how many args we have yet, just
7888 use the unconverted ones for now. */
7890 else
7892 }
7895 {
7898 }
7899 else
7902 in_decl);
7906 }
7910 {
7915 }
7920 else
7921 {
7924 }
7931 }
7933 /* Returns the number of pack expansions in the template argument vector
7934 ARGS. */
7936 static int
7938 {
7943 {
7947 }
7949 }
7951 /* Convert all template arguments to their appropriate types, and
7952 return a vector containing the innermost resulting template
7953 arguments. If any error occurs, return error_mark_node. Error and
7954 warning messages are issued under control of COMPLAIN.
7956 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7957 for arguments not specified in ARGS. Otherwise, if
7958 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7959 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7960 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7961 ARGS. */
7963 static tree
7965 tree args,
7966 tree in_decl,
7967 tsubst_flags_t complain,
7970 {
7972 tree orig_inner_args;
7973 tree inner_args;
7974 tree new_args;
7975 tree new_inner_args;
7979 /* When used as a boolean value, indicates whether this is a
7980 variadic template parameter list. Since it's an int, we can also
7981 subtract it from nparms to get the number of non-variadic
7982 parameters. */
7987 /* Likewise for parameters with default arguments. */
7995 /* Determine if there are any parameter packs or default arguments. */
7997 {
8005 }
8008 /* If there are no parameters that follow a parameter pack, we need to
8009 expand any argument packs so that we can deduce a parameter pack from
8010 some non-packed args followed by an argument pack, as in variadic85.C.
8011 If there are such parameters, we need to leave argument packs intact
8012 so the arguments are assigned properly. This can happen when dealing
8013 with a nested class inside a partial specialization of a class
8014 template, as in variadic92.C, or when deducing a template parameter pack
8015 from a sub-declarator, as in variadic114.C. */
8019 /* Count any pack expansion args. */
8025 && require_all_args
8026 && !variadic_args_p
8027 && (!use_default_args
8030 {
8032 {
8034 {
8038 }
8039 else
8046 }
8049 }
8050 /* We can't pass a pack expansion to a non-pack parameter of an alias
8051 template (DR 1430). */
8055 && variadic_args_p
8057 {
8059 {
8061 {
8067 {
8070 "pack expansion argument for non-pack parameter "
8072 else
8074 "pack expansion argument for non-pack parameter "
8078 }
8079 }
8081 found:;
8082 }
8084 }
8086 /* We need to evaluate the template arguments, even though this
8087 template-id may be nested within a "sizeof". */
8096 {
8097 tree arg;
8098 tree parm;
8100 /* Get the Ith template parameter. */
8104 {
8107 }
8109 /* Calculate the next argument. */
8112 else
8117 {
8118 /* Some arguments will be placed in the
8119 template parameter pack PARM. */
8126 {
8127 /* We don't know how many args we have yet, just use the
8128 unconverted (and still packed) ones for now. */
8132 }
8136 /* Store this argument. */
8138 {
8139 lost++;
8140 /* We are done with all of the arguments. */
8142 }
8143 else
8144 {
8147 }
8150 }
8152 {
8154 {
8155 /* "If every valid specialization of a variadic template
8156 requires an empty template parameter pack, the template is
8157 ill-formed, no diagnostic required." So check that the
8158 pattern works with this parameter. */
8163 in_decl);
8165 {
8170 }
8172 /* Recover from missing typename. */
8176 /* We don't know how many args we have yet, just
8177 use the unconverted ones for now. */
8181 }
8182 }
8184 {
8185 /* There must be a default arg in this case. */
8188 /* The position of the first default template argument,
8189 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8190 Record that. */
8194 }
8195 else
8199 {
8202 }
8204 /* This only occurs if there was an error in the template
8205 parameter list itself (which we would already have
8206 reported) that we are trying to recover from, e.g., a class
8207 template with a parameter list such as
8208 template<typename..., typename>. */
8210 else
8216 lost++;
8218 }
8223 {
8225 {
8230 }
8232 }
8242 }
8244 /* Convert all template arguments to their appropriate types, and
8245 return a vector containing the innermost resulting template
8246 arguments. If any error occurs, return error_mark_node. Error and
8247 warning messages are not issued.
8249 Note that no function argument deduction is performed, and default
8250 arguments are used to fill in unspecified arguments. */
8251 tree
8253 {
8255 }
8257 /* Convert all template arguments to their appropriate type, and
8258 instantiate default arguments as needed. This returns a vector
8259 containing the innermost resulting template arguments, or
8260 error_mark_node if unsuccessful. */
8261 tree
8263 tsubst_flags_t complain)
8264 {
8266 }
8268 /* Like coerce_template_parms. If PARMS represents all template
8269 parameters levels, this function returns a vector of vectors
8270 representing all the resulting argument levels. Note that in this
8271 case, only the innermost arguments are coerced because the
8272 outermost ones are supposed to have been coerced already.
8274 Otherwise, if PARMS represents only (the innermost) vector of
8275 parameters, this function returns a vector containing just the
8276 innermost resulting arguments. */
8278 static tree
8280 tree args,
8281 tree in_decl,
8282 tsubst_flags_t complain,
8285 {
8288 tree coerced_args;
8291 {
8293 tree level;
8299 {
8300 tree l;
8304 require_all_args,
8305 use_default_args);
8306 else
8313 }
8314 }
8315 else
8318 require_all_args,
8319 use_default_args);
8321 }
8323 /* Returns 1 if template args OT and NT are equivalent. */
8325 int
8327 {
8336 /* For member templates */
8345 {
8362 }
8366 {
8369 /* Don't treat an alias template specialization with dependent
8370 arguments as equivalent to its underlying type when used as a
8371 template argument; we need them to be distinct so that we
8372 substitute into the specialization arguments at instantiation
8373 time. And aliases can't be equivalent without being ==, so
8374 we don't need to look any deeper.
8376 During partial ordering, however, we need to treat them normally so
8377 that we can order uses of the same alias with different
8378 cv-qualification (79960). */
8382 else
8384 }
8387 else
8388 {
8389 /* Try to treat a template non-type argument that has been converted
8390 to the parameter type as equivalent to one that hasn't yet. */
8403 }
8404 }
8406 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8407 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8408 NEWARG_PTR with the offending arguments if they are non-NULL. */
8410 int
8414 {
8427 {
8432 {
8438 }
8439 }
8441 }
8445 {
8447 }
8449 static void
8451 {
8461 /* We are called both from instantiate_decl, where we've already had a
8462 tinst_level pushed, and instantiate_template, where we haven't.
8463 Compensate. */
8474 else
8483 }
8486 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8487 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8488 documentation for TEMPLATE_ID_EXPR. */
8490 tree
8492 {
8493 tree type;
8501 {
8504 }
8507 {
8509 unknown_type_node,
8511 arglist);
8513 }
8520 }
8522 /* Within the scope of a template class S<T>, the name S gets bound
8523 (in build_self_reference) to a TYPE_DECL for the class, not a
8524 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8525 or one of its enclosing classes, and that type is a template,
8526 return the associated TEMPLATE_DECL. Otherwise, the original
8527 DECL is returned.
8529 Also handle the case when DECL is a TREE_LIST of ambiguous
8530 injected-class-names from different bases. */
8532 tree
8534 {
8538 /* DR 176: A lookup that finds an injected-class-name (10.2
8539 [class.member.lookup]) can result in an ambiguity in certain cases
8540 (for example, if it is found in more than one base class). If all of
8541 the injected-class-names that are found refer to specializations of
8542 the same class template, and if the name is followed by a
8543 template-argument-list, the reference refers to the class template
8544 itself and not a specialization thereof, and is not ambiguous. */
8546 {
8549 {
8555 }
8558 else
8560 }
8566 }
8568 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8569 parameters, find the desired type.
8571 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8573 IN_DECL, if non-NULL, is the template declaration we are trying to
8574 instantiate.
8576 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8577 the class we are looking up.
8579 Issue error and warning messages under control of COMPLAIN.
8581 If the template class is really a local class in a template
8582 function, then the FUNCTION_CONTEXT is the function in which it is
8583 being instantiated.
8585 ??? Note that this function is currently called *twice* for each
8586 template-id: the first time from the parser, while creating the
8587 incomplete type (finish_template_type), and the second type during the
8588 real instantiation (instantiate_template_class). This is surely something
8589 that we want to avoid. It also causes some problems with argument
8590 coercion (see convert_nontype_argument for more information on this). */
8592 static tree
8595 {
8597 tree t;
8600 spec_entry elt;
8601 hashval_t hash;
8604 {
8608 else
8609 {
8616 }
8619 }
8621 {
8624 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8625 an implicit typename for the second A. Deal with it. */
8630 {
8633 }
8634 }
8637 {
8640 }
8642 {
8646 }
8648 {
8651 }
8653 /* Issue an error message if we didn't find a template. */
8655 {
8659 }
8662 /* Make sure it's a user visible template, if it was named by
8663 the user. */
8666 {
8668 {
8672 }
8674 }
8678 /* An alias that just changes the name of a template is equivalent to the
8679 other template, so if any of the arguments are pack expansions, strip
8680 the alias to avoid problems with a pack expansion passed to a non-pack
8681 alias template parameter (DR 1430). */
8686 {
8687 tree parm;
8696 }
8697 else
8698 {
8700 tree gen_tmpl;
8701 tree type_decl;
8709 /* An error occurred while building the template TEMPL, and a
8710 diagnostic has most certainly been emitted for that
8711 already. Let's propagate that error. */
8720 {
8721 /* We've been given an incomplete set of template arguments.
8722 For example, given:
8724 template <class T> struct S1 {
8725 template <class U> struct S2 {};
8726 template <class U> struct S2<U*> {};
8727 };
8729 we will be called with an ARGLIST of `U*', but the
8730 TEMPLATE will be `template <class T> template
8731 <class U> struct S1<T>::S2'. We must fill in the missing
8732 arguments. */
8736 }
8738 /* Now we should have enough arguments. */
8741 /* From here on, we're only interested in the most general
8742 template. */
8744 /* Calculate the BOUND_ARGS. These will be the args that are
8745 actually tsubst'd into the definition to create the
8746 instantiation. */
8748 complain,
8753 /* We were unable to bind the arguments. */
8756 /* In the scope of a template class, explicit references to the
8757 template class refer to the type of the template, not any
8758 instantiation of it. For example, in:
8760 template <class T> class C { void f(C<T>); }
8762 the `C<T>' is just the same as `C'. Outside of the
8763 class, however, such a reference is an instantiation. */
8767 {
8772 }
8774 /* If we already have this specialization, return it. */
8784 /* If the the template's constraints are not satisfied,
8785 then we cannot form a valid type.
8787 Note that the check is deferred until after the hash
8788 lookup. This prevents redundant checks on previously
8789 instantiated specializations. */
8791 {
8793 {
8796 }
8798 }
8802 /* If the deduced arguments are invalid, then the binding
8803 failed. */
8807 complain))
8814 {
8819 }
8829 /* Create the type. */
8831 {
8832 /* The user referred to a specialization of an alias
8833 template represented by GEN_TMPL.
8835 [temp.alias]/2 says:
8837 When a template-id refers to the specialization of an
8838 alias template, it is equivalent to the associated
8839 type obtained by substitution of its
8840 template-arguments for the template-parameters in the
8841 type-id of the alias template. */
8844 /* Note that the call above (by indirectly calling
8845 register_specialization in tsubst_decl) registers the
8846 TYPE_DECL representing the specialization of the alias
8847 template. So next time someone substitutes ARGLIST for
8848 the template parms into the alias template (GEN_TMPL),
8849 she'll get that TYPE_DECL back. */
8853 }
8855 {
8857 {
8868 }
8869 else
8870 {
8871 /* We don't want to call start_enum for this type, since
8872 the values for the enumeration constants may involve
8873 template parameters. And, no one should be interested
8874 in the enumeration constants for such a type. */
8877 }
8881 }
8883 {
8889 /* A local class. Make sure the decl gets registered properly. */
8894 /* This instantiation is another name for the primary
8895 template type. Set the TYPE_CANONICAL field
8896 appropriately. */
8899 /* Some of the template arguments require structural
8900 equality testing, so this template class requires
8901 structural equality testing. */
8903 }
8904 else
8907 /* If we called start_enum or pushtag above, this information
8908 will already be set up. */
8910 {
8917 }
8918 else
8922 {
8928 {
8931 }
8932 }
8936 {
8940 {
8941 tree attributes
8949 }
8950 }
8952 /* Let's consider the explicit specialization of a member
8953 of a class template specialization that is implicitly instantiated,
8954 e.g.:
8955 template<class T>
8956 struct S
8957 {
8958 template<class U> struct M {}; //#0
8959 };
8961 template<>
8962 template<>
8963 struct S<int>::M<char> //#1
8964 {
8965 int i;
8966 };
8967 [temp.expl.spec]/4 says this is valid.
8969 In this case, when we write:
8970 S<int>::M<char> m;
8972 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8973 the one of #0.
8975 When we encounter #1, we want to store the partial instantiation
8976 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8978 For all cases other than this "explicit specialization of member of a
8979 class template", we just want to store the most general template into
8980 the CLASSTYPE_TI_TEMPLATE of M.
8982 This case of "explicit specialization of member of a class template"
8983 only happens when:
8984 1/ the enclosing class is an instantiation of, and therefore not
8985 the same as, the context of the most general template, and
8986 2/ we aren't looking at the partial instantiation itself, i.e.
8987 the innermost arguments are not the same as the innermost parms of
8988 the most general template.
8990 So it's only when 1/ and 2/ happens that we want to use the partial
8991 instantiation of the member template in lieu of its most general
8992 template. */
8996 /* the enclosing class must be an instantiation... */
8999 {
9003 tree partial_inst_args =
9010 use_partial_inst_tmpl =
9011 /*...and we must not be looking at the partial instantiation
9012 itself. */
9014 partial_inst_args);
9015 }
9018 /* This case is easy; there are no member templates involved. */
9020 else
9021 {
9022 /* This is a full instantiation of a member template. Find
9023 the partial instantiation of which this is an instance. */
9025 /* Temporarily reduce by one the number of levels in the ARGLIST
9026 so as to avoid comparing the last set of arguments. */
9030 /* FOUND is either a proper class type, or an alias
9031 template specialization. In the later case, it's a
9032 TYPE_DECL, resulting from the substituting of arguments
9033 for parameters in the TYPE_DECL of the alias template
9034 done earlier. So be careful while getting the template
9035 of FOUND. */
9037 ? found
9041 }
9043 // Build template info for the new specialization.
9052 /* Note this use of the partial instantiation so we can check it
9053 later in maybe_process_partial_specialization. */
9060 /* Now that the type has been registered on the instantiations
9061 list, we set up the enumerators. Because the enumeration
9062 constants may involve the enumeration type itself, we make
9063 sure to register the type first, and then create the
9064 constants. That way, doing tsubst_expr for the enumeration
9065 constants won't result in recursive calls here; we'll find
9066 the instantiation and exit above. */
9070 /* If the type makes use of template parameters, the
9071 code that generates debugging information will crash. */
9074 /* Possibly limit visibility based on template args. */
9081 }
9082 }
9084 /* Wrapper for lookup_template_class_1. */
9086 tree
9089 {
9090 tree ret;
9096 }
9098 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9100 tree
9102 {
9103 /* The type of the expression is NULL_TREE since the template-id could refer
9104 to an explicit or partial specialization. */
9107 /* Except that concepts are always bool. */
9110 }
9112 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9114 tree
9116 {
9120 /* We never want to return a VAR_DECL for a variable concept, since they
9121 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9136 {
9138 {
9141 }
9143 }
9145 /* If a template-id refers to a specialization of a variable
9146 concept, then the expression is true if and only if the
9147 concept's constraints are satisfied by the given template
9148 arguments.
9150 NOTE: This is an extension of Concepts Lite TS that
9151 allows constraints to be used in expressions. */
9153 {
9156 }
9159 }
9161 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9162 TARGS template args, and instantiate it if it's not dependent. */
9164 tree
9166 tsubst_flags_t complain)
9167 {
9170 {
9173 }
9176 }
9178 \f
9179 struct pair_fn_data
9180 {
9181 tree_fn_t fn;
9182 tree_fn_t any_fn;
9184 /* True when we should also visit template parameters that occur in
9185 non-deduced contexts. */
9188 };
9190 /* Called from for_each_template_parm via walk_tree. */
9192 static tree
9194 {
9201 #define WALK_SUBTREE(NODE) \
9202 do \
9203 { \
9204 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9205 pfd->include_nondeduced_p, \
9206 pfd->any_fn); \
9207 if (result) goto out; \
9208 } \
9209 while (0)
9219 {
9223 /* Fall through. */
9229 else
9239 /* Since we're not going to walk subtrees, we have to do this
9240 explicitly here. */
9242 /* Fall through. */
9245 /* Check the return type. */
9248 /* Check the parameter types. Since default arguments are not
9249 instantiated until they are needed, the TYPE_ARG_TYPES may
9250 contain expressions that involve template parameters. But,
9251 no-one should be looking at them yet. And, once they're
9252 instantiated, they don't contain template parameters, so
9253 there's no point in looking at them then, either. */
9254 {
9255 tree parm;
9260 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9261 want walk_tree walking into them itself. */
9263 }
9266 {
9270 }
9287 /* Fall through. */
9299 /* Record template parameters such as `T' inside `TT<T>'. */
9301 /* Fall through. */
9313 /* A template template parameter is encountered. */
9317 /* Already substituted template template parameter */
9322 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9323 partial instantiation. */
9335 /* If there's no type, then this thing must be some expression
9336 involving template parameters. */
9358 }
9360 #undef WALK_SUBTREE
9362 /* We didn't find any template parameters we liked. */
9363 out:
9365 }
9367 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9368 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9369 call FN with the parameter and the DATA.
9370 If FN returns nonzero, the iteration is terminated, and
9371 for_each_template_parm returns 1. Otherwise, the iteration
9372 continues. If FN never returns a nonzero value, the value
9373 returned by for_each_template_parm is 0. If FN is NULL, it is
9374 considered to be the function which always returns 1.
9376 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9377 parameters that occur in non-deduced contexts. When false, only
9378 visits those template parameters that can be deduced. */
9380 static tree
9384 tree_fn_t any_fn)
9385 {
9387 tree result;
9389 /* Set up. */
9395 /* Walk the tree. (Conceptually, we would like to walk without
9396 duplicates, but for_each_template_parm_r recursively calls
9397 for_each_template_parm, so we would need to reorganize a fair
9398 bit to use walk_tree_without_duplicates, so we keep our own
9399 visited list.) */
9402 else
9405 for_each_template_parm_r,
9409 /* Clean up. */
9411 {
9414 }
9417 }
9419 /* Returns true if T depends on any template parameter. */
9421 int
9423 {
9453 else
9454 {
9457 }
9462 }
9464 /* Returns true iff current_function_decl is an incompletely instantiated
9465 template. Useful instead of processing_template_decl because the latter
9466 is set to 0 during instantiate_non_dependent_expr. */
9468 bool
9470 {
9479 }
9481 /* Returns true if T depends on any template parameter with level LEVEL. */
9483 bool
9485 {
9488 }
9490 /* Returns true if the signature of DECL depends on any template parameter from
9491 its enclosing class. */
9493 bool
9495 {
9505 template_parm_outer_level,
9515 }
9517 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9518 ill-formed translation unit, i.e. a variable or function that isn't
9519 usable in a constant expression. */
9523 {
9527 }
9529 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9530 neglectable and instantiated from within an erroneous instantiation. */
9532 static bool
9534 {
9545 }
9553 /* We're starting to instantiate D; record the template instantiation context
9554 for diagnostics and to restore it later. */
9556 bool
9558 {
9560 }
9562 /* We're starting to instantiate D; record the template instantiation context
9563 at LOC for diagnostics and to restore it later. */
9565 bool
9567 {
9571 {
9572 /* Tell error.c not to try to instantiate any templates. */
9575 "template instantiation depth exceeds maximum of %d"
9577 max_tinst_depth);
9579 }
9581 /* If the current instantiation caused problems, don't let it instantiate
9582 anything else. Do allow deduction substitution and decls usable in
9583 constant expressions. */
9587 /* When not -quiet, dump template instantiations other than functions, since
9588 announce_function will take care of those. */
9607 }
9609 /* We're done instantiating this template; return to the instantiation
9610 context. */
9612 void
9614 {
9615 /* Restore the filename and line number stashed away when we started
9616 this instantiation. */
9620 }
9622 /* We're instantiating a deferred template; restore the template
9623 instantiation context in which the instantiation was requested, which
9624 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9626 static tree
9628 {
9640 }
9642 /* Returns the TINST_LEVEL which gives the original instantiation
9643 context. */
9647 {
9653 }
9655 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9656 vector of template arguments, as for tsubst.
9658 Returns an appropriate tsubst'd friend declaration. */
9660 static tree
9662 {
9663 tree new_friend;
9668 /* This was a friend declared with an explicit template
9669 argument list, e.g.:
9671 friend void f<>(T);
9673 to indicate that f was a template instantiation, not a new
9674 function declaration. Now, we have to figure out what
9675 instantiation of what template. */
9676 {
9678 tree new_args;
9679 tree tmpl;
9682 /* Friend functions are looked up in the containing namespace scope.
9683 We must enter that scope, to avoid finding member functions of the
9684 current class with same name. */
9699 tsk_none);
9701 }
9705 /* The NEW_FRIEND will look like an instantiation, to the
9706 compiler, but is not an instantiation from the point of view of
9707 the language. For example, we might have had:
9709 template <class T> struct S {
9710 template <class U> friend void f(T, U);
9711 };
9713 Then, in S<int>, template <class U> void f(int, U) is not an
9714 instantiation of anything. */
9720 {
9724 }
9726 /* The mangled name for the NEW_FRIEND is incorrect. The function
9727 is not a template instantiation and should not be mangled like
9728 one. Therefore, we forget the mangling here; we'll recompute it
9729 later if we need it. */
9731 {
9734 }
9737 {
9738 tree old_decl;
9739 tree new_friend_template_info;
9740 tree new_friend_result_template_info;
9741 tree ns;
9744 /* We must save some information from NEW_FRIEND before calling
9745 duplicate decls since that function will free NEW_FRIEND if
9746 possible. */
9748 new_friend_is_defn =
9753 {
9754 /* This declaration is a `primary' template. */
9757 new_friend_result_template_info
9759 }
9760 else
9763 /* Inside pushdecl_namespace_level, we will push into the
9764 current namespace. However, the friend function should go
9765 into the namespace of the template. */
9775 {
9776 /* This new friend declaration matched an existing
9777 declaration. For example, given:
9779 template <class T> void f(T);
9780 template <class U> class C {
9781 template <class T> friend void f(T) {}
9782 };
9784 the friend declaration actually provides the definition
9785 of `f', once C has been instantiated for some type. So,
9786 old_decl will be the out-of-class template declaration,
9787 while new_friend is the in-class definition.
9789 But, if `f' was called before this point, the
9790 instantiation of `f' will have DECL_TI_ARGS corresponding
9791 to `T' but not to `U', references to which might appear
9792 in the definition of `f'. Previously, the most general
9793 template for an instantiation of `f' was the out-of-class
9794 version; now it is the in-class version. Therefore, we
9795 run through all specialization of `f', adding to their
9796 DECL_TI_ARGS appropriately. In particular, they need a
9797 new set of outer arguments, corresponding to the
9798 arguments for this class instantiation.
9800 The same situation can arise with something like this:
9802 friend void f(int);
9803 template <class T> class C {
9804 friend void f(T) {}
9805 };
9807 when `C<int>' is instantiated. Now, `f(int)' is defined
9808 in the class. */
9811 /* On the other hand, if the in-class declaration does
9812 *not* provide a definition, then we don't want to alter
9813 existing definitions. We can just leave everything
9814 alone. */
9815 ;
9816 else
9817 {
9821 /* Overwrite whatever template info was there before, if
9822 any, with the new template information pertaining to
9823 the declaration. */
9827 {
9828 /* We should have called reregister_specialization in
9829 duplicate_decls. */
9834 /* Instantiate it if the global has already been used. */
9838 }
9839 else
9840 {
9841 tree t;
9843 /* Indicate that the old function template is a partial
9844 instantiation. */
9852 /* Reassign any specializations already in the hash table
9853 to the new more general template, and add the
9854 additional template args. */
9858 {
9860 spec_entry elt;
9872 register_specialization
9875 }
9877 }
9878 }
9880 /* The information from NEW_FRIEND has been merged into OLD_DECL
9881 by duplicate_decls. */
9883 }
9884 }
9885 else
9886 {
9890 /* In the code
9891 template <class T> class C {
9892 template <class U> friend void C1<U>::f (); // case 1
9893 friend void C2<T>::f (); // case 2
9894 };
9895 we only need to make sure CONTEXT is a complete type for
9896 case 2. To distinguish between the two cases, we note that
9897 CONTEXT of case 1 remains dependent type after tsubst while
9898 this isn't true for case 2. */
9908 {
9910 /* do_friend adds the TEMPLATE_DECL for any member friend
9911 template even if it isn't a member template, i.e.
9912 template <class T> friend A<T>::f();
9913 Look through it in that case. */
9917 /* Check to see that the declaration is really present, and,
9918 possibly obtain an improved declaration. */
9923 }
9924 }
9927 }
9929 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9930 template arguments, as for tsubst.
9932 Returns an appropriate tsubst'd friend type or error_mark_node on
9933 failure. */
9935 static tree
9937 {
9938 tree friend_type;
9939 tree tmpl;
9940 tree context;
9943 {
9946 }
9951 {
9954 else
9956 }
9958 /* Look for a class template declaration. We look for hidden names
9959 because two friend declarations of the same template are the
9960 same. For example, in:
9962 struct A {
9963 template <typename> friend class F;
9964 };
9965 template <typename> struct B {
9966 template <typename> friend class F;
9967 };
9969 both F templates are the same. */
9973 /* But, if we don't find one, it might be because we're in a
9974 situation like this:
9976 template <class T>
9977 struct S {
9978 template <class U>
9979 friend struct S;
9980 };
9982 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9983 for `S<int>', not the TEMPLATE_DECL. */
9985 {
9988 }
9991 {
9992 /* The friend template has already been declared. Just
9993 check to see that the declarations match, and install any new
9994 default parameters. We must tsubst the default parameters,
9995 of course. We only need the innermost template parameters
9996 because that is all that redeclare_class_template will look
9997 at. */
10000 {
10001 tree parms;
10002 location_t saved_input_location;
10012 }
10015 }
10016 else
10017 {
10018 /* The friend template has not already been declared. In this
10019 case, the instantiation of the template class will cause the
10020 injection of this template into the global scope. */
10025 /* The new TMPL is not an instantiation of anything, so we
10026 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10027 the new type because that is supposed to be the corresponding
10028 template decl, i.e., TMPL. */
10035 /* Inject this template into the global scope. */
10037 }
10040 {
10043 else
10045 }
10048 }
10050 /* Returns zero if TYPE cannot be completed later due to circularity.
10051 Otherwise returns one. */
10053 static int
10055 {
10065 else
10067 }
10072 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10073 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10075 static tree
10078 {
10087 {
10094 clauses
10098 else
10100 }
10101 /* If the first attribute argument is an identifier, don't
10102 pass it through tsubst. Attributes like mode, format,
10103 cleanup and several target specific attributes expect it
10104 unmodified. */
10106 {
10107 tree chain
10112 }
10114 {
10115 /* An attribute pack expansion. */
10124 {
10128 }
10130 }
10131 else
10138 }
10140 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10141 unchanged or a new TREE_LIST chain. */
10143 static tree
10146 {
10151 {
10155 }
10159 {
10162 {
10165 {
10167 do
10172 }
10173 }
10175 }
10178 }
10180 /* Apply any attributes which had to be deferred until instantiation
10181 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10182 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10184 static void
10187 {
10189 tree t;
10196 {
10200 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10201 to our attributes parameter. */
10203 }
10204 else
10205 {
10207 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10208 lookup_template_class_1, and should be preserved. */
10212 }
10216 {
10220 }
10224 {
10229 {
10232 {
10236 do
10239 }
10240 else
10242 }
10245 }
10246 }
10248 /* Perform (or defer) access check for typedefs that were referenced
10249 from within the template TMPL code.
10250 This is a subroutine of instantiate_decl and instantiate_class_template.
10251 TMPL is the template to consider and TARGS is the list of arguments of
10252 that template. */
10254 static void
10256 {
10257 location_t saved_location;
10268 {
10280 /* Make access check error messages point to the location
10281 of the use of the typedef. */
10285 tf_warning_or_error);
10286 }
10288 }
10290 static tree
10292 {
10294 tree typedecl;
10295 tree pbinfo;
10296 tree base_list;
10298 tree fn_context;
10307 /* Figure out which template is being instantiated. */
10311 /* Determine what specialization of the original template to
10312 instantiate. */
10315 {
10318 }
10320 {
10321 /* This TYPE is actually an instantiation of a partial
10322 specialization. We replace the innermost set of ARGS with
10323 the arguments appropriate for substitution. For example,
10324 given:
10326 template <class T> struct S {};
10327 template <class T> struct S<T*> {};
10329 and supposing that we are instantiating S<int*>, ARGS will
10330 presently be {int*} -- but we need {int}. */
10333 }
10334 else
10335 {
10338 }
10340 /* If the template we're instantiating is incomplete, then clearly
10341 there's nothing we can do. */
10345 /* If we've recursively instantiated too many templates, stop. */
10349 /* Now we're really doing the instantiation. Mark the type as in
10350 the process of being defined. */
10353 /* We may be in the middle of deferred access check. Disable
10354 it now. */
10361 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10366 else
10367 {
10370 }
10371 /* Use #pragma pack from the template context. */
10377 /* Set the input location to the most specialized template definition.
10378 This is needed if tsubsting causes an error. */
10390 {
10393 /* Adjust visibility for template arguments. */
10395 }
10401 /* We should never instantiate a nested class before its enclosing
10402 class; we need to look up the nested class by name before we can
10403 instantiate it, and that lookup should instantiate the enclosing
10404 class. */
10410 {
10411 tree pbase_binfo;
10412 tree pushed_scope;
10415 /* We must enter the scope containing the type, as that is where
10416 the accessibility of types named in dependent bases are
10417 looked up from. */
10420 /* Substitute into each of the bases to determine the actual
10421 basetypes. */
10423 {
10424 tree base;
10430 {
10431 expanded_bases =
10438 }
10441 {
10443 /* Extract the already-expanded base class. */
10445 else
10446 /* Substitute to figure out the base class. */
10448 NULL_TREE);
10456 }
10457 }
10459 /* The list is now in reverse order; correct that. */
10464 }
10465 /* Now call xref_basetypes to set up all the base-class
10466 information. */
10474 /* Now that our base classes are set up, enter the scope of the
10475 class, so that name lookups into base classes, etc. will work
10476 correctly. This is precisely analogous to what we do in
10477 begin_class_definition when defining an ordinary non-template
10478 class, except we also need to push the enclosing classes. */
10481 /* Now members are processed in the order of declaration. */
10484 {
10488 {
10490 {
10491 /* Build new CLASSTYPE_NESTED_UTDS. */
10493 tree newtag;
10499 /* If the member is a class template, then -- even after
10500 substitution -- there may be dependent types in the
10501 template argument list for the class. We increment
10502 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10503 that function will assume that no types are dependent
10504 when outside of a template. */
10514 {
10518 /* Unfortunately, lookup_template_class sets
10519 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10520 instantiation (i.e., for the type of a member
10521 template class nested within a template class.)
10522 This behavior is required for
10523 maybe_process_partial_specialization to work
10524 correctly, but is not accurate in this case;
10525 the TAG is not an instantiation of anything.
10526 (The corresponding TEMPLATE_DECL is an
10527 instantiation, but the TYPE is not.) */
10530 /* Now, we call pushtag to put this NEWTAG into the scope of
10531 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10532 pushtag calling push_template_decl. We don't have to do
10533 this for enums because it will already have been done in
10534 tsubst_enum. */
10538 }
10539 }
10541 {
10542 /* Build new TYPE_METHODS. */
10543 tree r;
10552 /* Instantiate members marked with attribute used. */
10558 }
10561 /* A closure type for a lambda in a default argument for a
10562 member template. Ignore it; it will be instantiated with
10564 else
10565 {
10566 /* Build new TYPE_FIELDS. */
10568 {
10569 tree condition;
10572 condition =
10582 }
10584 {
10585 tree r;
10589 /* The file and line for this declaration, to
10590 assist in error message reporting. Since we
10591 called push_tinst_level above, we don't need to
10592 restore these. */
10602 {
10603 /* A capture pack became multiple fields. */
10606 }
10609 {
10613 {
10614 /* In [temp.inst]:
10616 [t]he initialization (and any associated
10617 side-effects) of a static data member does
10618 not occur unless the static data member is
10619 itself used in a way that requires the
10620 definition of the static data member to
10621 exist.
10623 Therefore, we do not substitute into the
10624 initialized for the static data member here. */
10625 finish_static_data_member_decl
10631 /* Instantiate members marked with attribute used. */
10634 }
10636 {
10637 /* Determine whether R has a valid type and can be
10638 completed later. If R is invalid, then its type
10639 is replaced by error_mark_node. */
10645 {
10646 /* If R's type couldn't be completed and
10647 it isn't a flexible array member (whose
10648 type is incomplete by definition) give
10649 an error. */
10652 }
10653 }
10655 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10656 such a thing will already have been added to the field
10657 list by tsubst_enum in finish_member_declaration in the
10658 CLASSTYPE_NESTED_UTDS case above. */
10662 {
10665 }
10666 }
10667 }
10668 }
10669 }
10670 else
10671 {
10674 {
10675 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10681 {
10682 /* template <class T> friend class C; */
10685 }
10687 {
10688 /* template <class T> friend class C::D; */
10694 }
10697 {
10698 /* This could be either
10700 friend class T::C;
10702 when dependent_type_p is false or
10704 template <class U> friend class T::C;
10706 otherwise. */
10707 /* Bump processing_template_decl in case this is something like
10708 template <class T> friend struct A<T>::B. */
10715 }
10718 {
10719 /* friend class C;
10721 where C hasn't been declared yet. Let's lookup name
10722 from namespace scope directly, bypassing any name that
10723 come from dependent base class. */
10726 /* The call to xref_tag_from_type does injection for friend
10727 classes. */
10729 friend_type =
10733 }
10735 /* friend class C<T>; */
10738 /* Otherwise it's
10740 friend class C;
10742 where C is already declared or
10744 friend class C<int>;
10746 We don't have to do anything in these cases. */
10749 /* Trick make_friend_class into realizing that the friend
10750 we're adding is a template, not an ordinary class. It's
10751 important that we use make_friend_class since it will
10752 perform some error-checking and output cross-reference
10753 information. */
10761 }
10762 else
10763 {
10764 /* Build new DECL_FRIENDLIST. */
10765 tree r;
10767 /* The file and line for this declaration, to
10768 assist in error message reporting. Since we
10769 called push_tinst_level above, we don't need to
10770 restore these. */
10774 {
10777 }
10782 {
10785 }
10786 }
10787 }
10788 }
10791 {
10792 /* Restore these before substituting into the lambda capture
10793 initializers. */
10796 }
10799 {
10802 {
10808 {
10809 /* Set function_depth to avoid garbage collection. */
10813 }
10815 /* We need to instantiate the capture list from the template
10816 after we've instantiated the closure members, but before we
10817 consider adding the conversion op. Also keep any captures
10818 that may have been added during instantiation of the op(). */
10820 tree tmpl_cap
10829 }
10830 else
10832 }
10834 /* Set the file and line number information to whatever is given for
10835 the class itself. This puts error messages involving generated
10836 implicit functions at a predictable point, and the same point
10837 that would be used for non-template classes. */
10844 /* We don't instantiate default arguments for member functions. 14.7.1:
10846 The implicit instantiation of a class template specialization causes
10847 the implicit instantiation of the declarations, but not of the
10848 definitions or default arguments, of the class member functions,
10849 member classes, static data members and member templates.... */
10851 /* Some typedefs referenced from within the template code need to be access
10852 checked at template instantiation time, i.e now. These types were
10853 added to the template at parsing time. Let's get those and perform
10854 the access checks then. */
10864 /* The vtable for a template class can be emitted in any translation
10865 unit in which the class is instantiated. When there is no key
10866 method, however, finish_struct_1 will already have added TYPE to
10867 the keyed_classes. */
10872 }
10874 /* Wrapper for instantiate_class_template_1. */
10876 tree
10878 {
10879 tree ret;
10884 }
10886 static tree
10888 {
10889 tree r;
10895 else
10896 {
10903 }
10905 }
10907 /* Given a function parameter pack TMPL_PARM and some function parameters
10908 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10909 and set *SPEC_P to point at the next point in the list. */
10911 tree
10913 {
10914 /* Collect all of the extra "packed" parameters into an
10915 argument pack. */
10916 tree parmvec;
10926 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10932 /* Build the argument packs. */
10937 }
10939 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10940 NONTYPE_ARGUMENT_PACK. */
10942 static tree
10944 {
10946 }
10948 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10949 pack expansion with no extra args, 2 if it has extra args, or 0
10950 if it is not a pack expansion. */
10952 static int
10954 {
10960 /* A decl pack is itself an expansion. */
10967 }
10970 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10972 static tree
10974 {
10981 }
10983 /* This is a subroutine of tsubst_pack_expansion.
10985 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10986 mechanism to store the (non complete list of) arguments of the
10987 substitution and return a non substituted pack expansion, in order
10988 to wait for when we have enough arguments to really perform the
10989 substitution. */
10991 static bool
10995 {
10996 /* If one pack has an expansion and another pack has a normal
10997 argument or if one pack has an empty argument and an another
10998 one hasn't then tsubst_pack_expansion cannot perform the
10999 substitution and need to fall back on the
11000 PACK_EXPANSION_EXTRA mechanism. */
11008 {
11011 parm_pack;
11013 {
11018 /* We can't substitute a pack expansion with extra args into
11019 our pattern. */
11023 else
11025 }
11029 }
11031 }
11033 /* [temp.variadic]/6 says that:
11035 The instantiation of a pack expansion [...]
11036 produces a list E1,E2, ..., En, where N is the number of elements
11037 in the pack expansion parameters.
11039 This subroutine of tsubst_pack_expansion produces one of these Ei.
11041 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11042 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11043 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11044 INDEX is the index 'i' of the element Ei to produce. ARGS,
11045 COMPLAIN, and IN_DECL are the same parameters as for the
11046 tsubst_pack_expansion function.
11048 The function returns the resulting Ei upon successful completion,
11049 or error_mark_node.
11051 Note that this function possibly modifies the ARGS parameter, so
11052 it's the responsibility of the caller to restore it. */
11054 static tree
11056 tree parm_packs,
11058 tree args /* This parm gets
11060 tsubst_flags_t complain,
11061 tree in_decl)
11062 {
11063 tree t;
11066 /* For each parameter pack, change the substitution of the parameter
11067 pack to the ith argument in its argument pack, then expand the
11068 pattern. */
11070 {
11075 ith_elem_is_expansion |=
11078 /* Select the Ith argument from the pack. */
11081 {
11083 {
11088 }
11089 else
11091 }
11092 else
11093 {
11098 {
11100 /* Update the corresponding argument. */
11102 }
11103 else
11104 /* Re-use the ARGUMENT_PACK_SELECT. */
11106 }
11108 }
11110 /* Substitute into the PATTERN with the (possibly altered)
11111 arguments. */
11113 /* Expanding a fixed parameter pack from
11114 coerce_template_parameter_pack. */
11119 {
11122 else
11125 }
11129 else
11132 /* If the Ith argument pack element is a pack expansion, then
11133 the Ith element resulting from the substituting is going to
11134 be a pack expansion as well. */
11139 }
11141 /* When the unexpanded parameter pack in a fold expression expands to an empty
11142 sequence, the value of the expression is as follows; the program is
11143 ill-formed if the operator is not listed in this table.
11145 && true
11146 || false
11147 , void() */
11149 tree
11151 {
11155 {
11164 }
11170 }
11172 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11173 form an expression that combines the two terms using the
11174 operator of T. */
11176 static tree
11178 {
11182 // Handle compound assignment operators.
11187 {
11197 complain);
11198 }
11199 }
11201 /* Substitute ARGS into the pack of a fold expression T. */
11205 {
11207 }
11209 /* Substitute ARGS into the pack of a fold expression T. */
11213 {
11215 }
11217 /* Expand a PACK of arguments into a grouped as left fold.
11218 Given a pack containing elements A0, A1, ..., An and an
11219 operator @, this builds the expression:
11221 ((A0 @ A1) @ A2) ... @ An
11223 Note that PACK must not be empty.
11225 The operator is defined by the original fold expression T. */
11227 static tree
11229 {
11232 {
11235 }
11237 }
11239 /* Substitute into a unary left fold expression. */
11241 static tree
11243 tree in_decl)
11244 {
11249 {
11253 }
11256 else
11258 }
11260 /* Substitute into a binary left fold expression.
11262 Do ths by building a single (non-empty) vector of argumnts and
11263 building the expression from those elements. */
11265 static tree
11267 tree in_decl)
11268 {
11277 {
11282 }
11290 }
11292 /* Expand a PACK of arguments into a grouped as right fold.
11293 Given a pack containing elementns A0, A1, ..., and an
11294 operator @, this builds the expression:
11296 A0@ ... (An-2 @ (An-1 @ An))
11298 Note that PACK must not be empty.
11300 The operator is defined by the original fold expression T. */
11302 tree
11304 {
11305 // Build the expression.
11309 {
11312 }
11314 }
11316 /* Substitute into a unary right fold expression. */
11318 static tree
11320 tree in_decl)
11321 {
11326 {
11330 }
11333 else
11335 }
11337 /* Substitute into a binary right fold expression.
11339 Do ths by building a single (non-empty) vector of arguments and
11340 building the expression from those elements. */
11342 static tree
11344 tree in_decl)
11345 {
11354 {
11359 }
11368 }
11371 /* Substitute ARGS into T, which is an pack expansion
11372 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11373 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11374 (if only a partial substitution could be performed) or
11375 ERROR_MARK_NODE if there was an error. */
11376 tree
11378 tree in_decl)
11379 {
11380 tree pattern;
11384 tree result;
11392 /* Add in any args remembered from an earlier partial instantiation. */
11397 /* Determine the argument packs that will instantiate the parameter
11398 packs used in the expansion expression. While we're at it,
11399 compute the number of arguments to be expanded and make sure it
11400 is consistent. */
11403 {
11410 {
11415 else
11418 }
11420 {
11421 /* ??? Support use in other patterns. */
11425 }
11427 {
11428 /* We know we have correct local_specializations if this
11429 expansion is at function scope, or if we're dealing with a
11430 local parameter in a requires expression; for the latter,
11431 tsubst_requires_expr set it up appropriately. */
11434 else
11435 /* We can't rely on local_specializations for a parameter
11436 name used later in a function declaration (such as in a
11437 late-specified return type). Even if it exists, it might
11438 have the wrong value for a recursive call. */
11442 {
11443 /* This parameter pack was used in an unevaluated context. Just
11444 make a dummy decl, since it's only used for its type. */
11447 /* Partial instantiation of the parm_pack, we can't build
11448 up an argument pack yet. */
11450 else
11452 }
11453 }
11456 else
11457 {
11463 }
11470 /* This can only happen if we forget to expand an argument
11471 pack somewhere else. Just return an error, silently. */
11472 {
11476 }
11479 {
11483 /* Don't bother trying to do a partial substitution with
11484 incomplete packs; we'll try again after deduction. */
11491 {
11496 pattern);
11497 else
11499 pattern);
11501 }
11503 /* Keep track of the parameter packs and their corresponding
11504 argument packs. */
11507 }
11508 else
11509 {
11510 /* We can't substitute for this parameter pack. We use a flag as
11511 well as the missing_level counter because function parameter
11512 packs don't have a level. */
11515 }
11516 }
11518 /* If the expansion is just T..., return the matching argument pack, unless
11519 we need to call convert_from_reference on all the elements. This is an
11520 important optimization; see c++/68422. */
11523 {
11525 /* Types need no adjustment, nor does sizeof..., and if we still have
11526 some pack expansion args we won't do anything yet. */
11531 /* Also optimize expression pack expansions if we can tell that the
11532 elements won't have reference type. */
11538 /* Otherwise use the normal path so we get convert_from_reference. */
11539 }
11541 /* We cannot expand this expansion expression, because we don't have
11542 all of the argument packs we need. */
11544 {
11545 /* We got some full packs, but we can't substitute them in until we
11546 have values for all the packs. So remember these until then. */
11551 }
11553 {
11554 /* There were no real arguments, we're just replacing a parameter
11555 pack with another version of itself. Substitute into the
11556 pattern and return a PACK_EXPANSION_*. The caller will need to
11557 deal with that. */
11561 else
11565 }
11570 {
11571 /* We're in a late-specified return type, so create our own local
11572 specializations map; the current map is either NULL or (in the
11573 case of recursive unification) might have bindings that we don't
11574 want to use or alter. */
11577 }
11579 /* For each argument in each argument pack, substitute into the
11580 pattern. */
11584 {
11586 i,
11588 in_decl);
11591 {
11594 }
11595 }
11597 /* Update ARGS to restore the substitution from parameter packs to
11598 their argument packs. */
11600 {
11606 else
11607 {
11615 /* Update the corresponding argument. */
11619 else
11621 }
11622 }
11625 {
11628 }
11630 /* If the dependent pack arguments were such that we end up with only a
11631 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11637 }
11639 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11640 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11641 parameter packs; all parms generated from a function parameter pack will
11642 have the same DECL_PARM_INDEX. */
11644 tree
11646 {
11648 tree patparm;
11651 {
11657 }
11658 else
11659 {
11664 }
11667 }
11669 /* Make an argument pack out of the TREE_VEC VEC. */
11671 static tree
11673 {
11674 tree pack;
11678 else
11679 {
11682 }
11685 }
11687 /* Return an exact copy of template args T that can be modified
11688 independently. */
11690 static tree
11692 {
11700 {
11705 }
11711 }
11713 /* Substitute ARGS into the vector or list of template arguments T. */
11715 static tree
11717 {
11729 {
11731 tree new_arg;
11736 {
11737 /* Substitute into an expansion expression. */
11741 /* Add to the expanded length adjustment the number of
11742 expanded arguments. We subtract one from this
11743 measurement, because the argument pack expression
11744 itself is already counted as 1 in
11745 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11746 the argument pack is empty. */
11748 }
11750 {
11751 /* Substitute into each of the arguments. */
11760 else
11765 }
11766 else
11775 }
11780 /* Make space for the expanded arguments coming from template
11781 argument packs. */
11783 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11784 arguments for a member template.
11785 In that case each TREE_VEC in ORIG_T represents a level of template
11786 arguments, and ORIG_T won't carry any non defaulted argument count.
11787 It will rather be the nested TREE_VECs that will carry one.
11788 In other words, ORIG_T carries a non defaulted argument count only
11789 if it doesn't contain any nested TREE_VEC. */
11791 {
11795 }
11797 {
11801 {
11804 /* Now expand the template argument pack "in place". */
11807 }
11808 else
11809 {
11811 out++;
11812 }
11813 }
11816 }
11818 /* Substitute ARGS into one level PARMS of template parameters. */
11820 static tree
11822 {
11829 {
11837 }
11840 }
11842 /* Return the result of substituting ARGS into the template parameters
11843 given by PARMS. If there are m levels of ARGS and m + n levels of
11844 PARMS, then the result will contain n levels of PARMS. For
11845 example, if PARMS is `template <class T> template <class U>
11846 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11847 result will be `template <int*, double, class V>'. */
11849 static tree
11851 {
11855 /* When substituting into a template, we must set
11856 PROCESSING_TEMPLATE_DECL as the template parameters may be
11857 dependent if they are based on one-another, and the dependency
11858 predicates are short-circuit outside of templates. */
11865 {
11872 }
11877 }
11879 /* Return the result of substituting ARGS into one template parameter
11880 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11881 parameter and which TREE_PURPOSE is the default argument of the
11882 template parameter. */
11884 static tree
11886 {
11907 }
11909 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11910 type T. If T is not an aggregate or enumeration type, it is
11911 handled as if by tsubst. IN_DECL is as for tsubst. If
11912 ENTERING_SCOPE is nonzero, T is the context for a template which
11913 we are presently tsubst'ing. Return the substituted value. */
11915 static tree
11917 tree args,
11918 tsubst_flags_t complain,
11919 tree in_decl,
11921 {
11926 {
11931 /* Fall through. */
11935 {
11936 tree argvec;
11937 tree context;
11938 tree r;
11942 /* In "sizeof(X<I>)" we need to evaluate "I". */
11948 /* First, determine the context for the type we are looking
11949 up. */
11952 {
11955 /* If context is a nested class inside a class template,
11956 it may still need to be instantiated (c++/33959). */
11958 }
11960 /* Then, figure out what arguments are appropriate for the
11961 type we are trying to find. For example, given:
11963 template <class T> struct S;
11964 template <class T, class U> void f(T, U) { S<U> su; }
11966 and supposing that we are instantiating f<int, double>,
11967 then our ARGS will be {int, double}, but, when looking up
11968 S we only want {double}. */
11973 else
11974 {
11978 }
11984 }
11985 else
11986 /* This is not a template type, so there's nothing to do. */
11991 }
11992 }
11994 /* Substitute into the default argument ARG (a default argument for
11995 FN), which has the indicated TYPE. */
11997 tree
11999 {
12004 /* This can happen in invalid code. */
12008 /* This default argument came from a template. Instantiate the
12009 default argument here, not in tsubst. In the case of
12010 something like:
12012 template <class T>
12013 struct S {
12014 static T t();
12015 void f(T = t());
12016 };
12018 we must be careful to do name lookup in the scope of S<T>,
12019 rather than in the current class. */
12021 /* The "this" pointer is not valid in a default argument. */
12023 {
12028 }
12031 /* The default argument expression may cause implicitly defined
12032 member functions to be synthesized, which will result in garbage
12033 collection. We must treat this situation as if we were within
12034 the body of function so as to avoid collecting live data on the
12035 stack. */
12043 /* Restore the "this" pointer. */
12045 {
12048 }
12055 /* Make sure the default argument is reasonable. */
12061 }
12063 /* Substitute into all the default arguments for FN. */
12065 static void
12067 {
12068 tree arg;
12069 tree tmpl_args;
12073 /* If this function is not yet instantiated, we certainly don't need
12074 its default arguments. */
12077 /* Don't do this again for clones. */
12082 arg;
12088 complain);
12089 }
12091 /* Substitute the ARGS into the T, which is a _DECL. Return the
12092 result of the substitution. Issue error and warning messages under
12093 control of COMPLAIN. */
12095 static tree
12097 {
12098 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12099 location_t saved_loc;
12104 /* Set the filename and linenumber to improve error-reporting. */
12109 {
12111 {
12112 /* We can get here when processing a member function template,
12113 member class template, or template template parameter. */
12115 tree spec;
12116 tree tmpl_args;
12117 tree full_args;
12120 {
12121 /* Template template parameter is treated here. */
12125 /* If we get a real template back, return it. This can happen in
12126 the context of most_specialized_partial_spec. */
12129 else
12130 /* The new TEMPLATE_DECL was built in
12131 reduce_template_parm_level. */
12134 }
12136 /* We might already have an instance of this template.
12137 The ARGS are for the surrounding class type, so the
12138 full args contain the tsubst'd args for the context,
12139 plus the innermost args from the template decl. */
12143 /* Because this is a template, the arguments will still be
12144 dependent, even after substitution. If
12145 PROCESSING_TEMPLATE_DECL is not set, the dependency
12146 predicates will short-circuit. */
12154 /* If this is a default template template argument,
12155 tsubst might not have changed anything. */
12162 {
12165 }
12167 /* Make a new template decl. It will be similar to the
12168 original, but will record the current template arguments.
12169 We also create a new function declaration, which is just
12170 like the old one, but points to this new template, rather
12171 than the old one. */
12176 // Build new template info linking to the original template decl.
12181 {
12182 tree new_type;
12190 /* For a partial specialization, we need to keep pointing to
12191 the primary template. */
12197 }
12198 else
12199 {
12200 tree new_decl;
12212 }
12218 /* The template parameters for this new template are all the
12219 template parameters for the old template, except the
12220 outermost level of parameters. */
12223 complain);
12229 /* Record this non-type partial instantiation. */
12233 }
12237 {
12238 tree ctx;
12241 tree gen_tmpl;
12242 tree type;
12247 /* Nobody should be tsubst'ing into non-template functions. */
12251 {
12252 tree spec;
12254 /* If T is not dependent, just return it. */
12258 /* Calculate the most general template of which R is a
12259 specialization, and the complete set of arguments used to
12260 specialize R. */
12263 (DECL_TEMPLATE_RESULT
12269 /* Check to see if we already have this specialization. */
12274 {
12277 }
12279 /* We can see more levels of arguments than parameters if
12280 there was a specialization of a member template, like
12281 this:
12283 template <class T> struct S { template <class U> void f(); }
12284 template <> template <class U> void S<int>::f(U);
12286 Here, we'll be substituting into the specialization,
12287 because that's where we can find the code we actually
12288 want to generate, but we'll have enough arguments for
12289 the most general template.
12291 We also deal with the peculiar case:
12293 template <class T> struct S {
12294 template <class U> friend void f();
12295 };
12296 template <class U> void f() {}
12297 template S<int>;
12298 template void f<double>();
12300 Here, the ARGS for the instantiation of will be {int,
12301 double}. But, we only need as many ARGS as there are
12302 levels of template parameters in CODE_PATTERN. We are
12303 careful not to get fooled into reducing the ARGS in
12304 situations like:
12306 template <class T> struct S { template <class U> void f(U); }
12307 template <class T> template <> void S<T>::f(int) {}
12309 which we can spot because the pattern will be a
12310 specialization in this case. */
12312 parms_depth =
12317 }
12318 else
12319 {
12320 /* This special case arises when we have something like this:
12322 template <class T> struct S {
12323 friend void f<int>(int, double);
12324 };
12326 Here, the DECL_TI_TEMPLATE for the friend declaration
12327 will be an IDENTIFIER_NODE. We are being called from
12328 tsubst_friend_function, and we want only to create a
12329 new decl (R) with appropriate types so that we can call
12330 determine_specialization. */
12332 }
12335 {
12338 else
12342 }
12343 else
12344 {
12347 }
12352 /* If we hit excessive deduction depth, the type is bogus even if
12353 it isn't error_mark_node, so don't build a decl. */
12357 /* We do NOT check for matching decls pushed separately at this
12358 point, as they may not represent instantiations of this
12359 template, and in any case are considered separate under the
12360 discrete model. */
12364 /* Clear out the mangled name and RTL for the instantiation. */
12367 /* Leave DECL_INITIAL set on deleted instantiations. */
12372 /* OpenMP UDRs have the only argument a reference to the declared
12373 type. We want to diagnose if the declared type is a reference,
12374 which is invalid, but as references to references are usually
12375 quietly merged, diagnose it here. */
12377 {
12378 tree argtype
12383 "reference type %qT in "
12387 argtype);
12388 }
12391 /* Type-conversion operator. Reconstruct the name, in
12392 case it's the name of one of the template's parameters. */
12402 /* If this is an instantiation of a function with internal
12403 linkage, we already know what object file linkage will be
12404 assigned to the instantiation. */
12413 /* We'll re-clone as appropriate in instantiate_template. */
12416 /* If we aren't complaining now, return on error before we register
12417 the specialization so that we'll complain eventually. */
12423 /* When instantiating a constrained member, substitute
12424 into the constraints to create a new constraint. */
12427 {
12430 }
12432 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12433 this in the special friend case mentioned above where
12434 GEN_TMPL is NULL. */
12436 {
12441 tree new_r
12444 /* We instantiated this while substituting into
12445 the type earlier (template/friend54.C). */
12448 /* We're not supposed to instantiate default arguments
12449 until they are called, for a template. But, for a
12450 declaration like:
12452 template <class T> void f ()
12453 { extern void g(int i = T()); }
12455 we should do the substitution when the template is
12456 instantiated. We handle the member function case in
12457 instantiate_class_template since the default arguments
12458 might refer to other members of the class. */
12463 }
12464 else
12467 /* Copy the list of befriending classes. */
12471 {
12475 in_decl);
12476 }
12479 {
12483 /* If this is an instantiation of a member template, clone it.
12484 If it isn't, that'll be handled by
12485 clone_constructors_and_destructors. */
12488 }
12499 /* Possibly limit visibility based on template args. */
12502 {
12506 }
12514 }
12518 {
12526 {
12527 /* If there is a local specialization that isn't a
12528 parameter pack, it means that we're doing a "simple"
12529 substitution from inside tsubst_pack_expansion. Just
12530 return the local specialization (which will be a single
12531 parm). */
12538 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12539 the parameters in this function parameter pack. */
12543 {
12546 /* Zero-length parameter packs are boring. Just substitute
12547 into the chain. */
12551 }
12552 else
12553 {
12554 /* All we did was update the type. Make a note of that. */
12557 }
12558 }
12560 /* Loop through all of the parameters we'll build. When T is
12561 a function parameter pack, LEN is the number of expanded
12562 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12565 {
12572 /* We're on the Ith parameter of the function parameter
12573 pack. */
12574 {
12575 /* Get the Ith type. */
12578 /* Rename the parameter to include the index. */
12581 }
12583 /* We're dealing with a normal parameter. */
12591 {
12594 else
12597 }
12607 /* Keep track of the first new parameter we
12608 generate. That's what will be returned to the
12609 caller. */
12613 /* Build a proper chain of parameters when substituting
12614 into a function parameter pack. */
12617 }
12619 /* If cp_unevaluated_operand is set, we're just looking for a
12620 single dummy parameter, so don't keep going. */
12625 /* FIRST_R contains the start of the chain we've built. */
12627 }
12631 {
12638 {
12639 /* This field is a lambda capture pack. Return a TREE_VEC of
12640 the expanded fields to instantiate_class_template_1 and
12641 store them in the specializations hash table as a
12642 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12646 {
12649 }
12650 else
12651 {
12652 /* All we did was update the type. Make a note of that. */
12655 }
12656 }
12659 {
12662 {
12666 }
12676 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12677 non-bit-fields DECL_INITIAL is a non-static data member
12678 initializer, which gets deferred instantiation. */
12684 {
12685 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12686 NSDMI in perform_member_init. Still set DECL_INITIAL
12687 so that we know there is one. */
12692 }
12693 /* We don't have to set DECL_CONTEXT here; it is set by
12694 finish_member_declaration. */
12702 }
12705 {
12710 }
12711 }
12715 /* We reach here only for member using decls. We also need to check
12716 uses_template_parms because DECL_DEPENDENT_P is not set for a
12717 using-declaration that designates a member of the current
12718 instantiation (c++/53549). */
12721 {
12725 {
12730 {
12734 {
12737 }
12738 else
12739 {
12742 }
12744 }
12745 }
12746 else
12747 {
12753 else
12754 {
12757 }
12758 }
12759 }
12760 else
12761 {
12764 }
12769 {
12772 tree spec;
12774 tree ctx;
12783 {
12784 /* If this is the canonical decl, we don't have to
12785 mess with instantiations, and often we can't (for
12786 typename, template type parms and such). Note that
12787 TYPE_NAME is not correct for the above test if
12788 we've copied the type for a typedef. */
12794 }
12796 /* Check to see if we already have the specialization we
12797 need. */
12800 {
12801 /* T is a static data member or namespace-scope entity.
12802 We have to substitute into namespace-scope variables
12803 (not just variable templates) because of cases like:
12805 template <class T> void f() { extern T t; }
12807 where the entity referenced is not known until
12808 instantiation time. */
12812 {
12814 complain,
12816 /* If CTX is unchanged, then T is in fact the
12817 specialization we want. That situation occurs when
12818 referencing a static data member within in its own
12819 class. We can use pointer equality, rather than
12820 same_type_p, because DECL_CONTEXT is always
12821 canonical... */
12823 /* ... unless T is a member template; in which
12824 case our caller can be willing to create a
12825 specialization of that template represented
12826 by T. */
12830 }
12833 {
12838 argvec = (coerce_innermost_template_parms
12846 }
12847 }
12848 else
12849 {
12850 /* A local variable. */
12852 /* Subsequent calls to pushdecl will fill this in. */
12854 /* Unless this is a reference to a static variable from an
12855 enclosing function, in which case we need to fill it in now. */
12857 {
12861 }
12863 }
12864 /* If we already have the specialization we need, there is
12865 nothing more to do. */
12867 {
12870 }
12872 /* Create a new node for the specialization we need. */
12875 {
12878 else
12885 }
12887 {
12888 /* Even if the original location is out of scope, the
12889 newly substituted one is not. */
12896 {
12897 /* It may seem that this case cannot occur, since:
12899 typedef void f();
12900 void g() { f x; }
12902 declares a function, not a variable. However:
12904 typedef void f();
12905 template <typename T> void g() { T t; }
12906 template void g<f>();
12908 is an attempt to declare a variable with function
12909 type. */
12911 /* R is not yet sufficiently initialized, so we
12912 just use its name. */
12915 }
12917 /* Wait until cp_finish_decl to set this again, to handle
12918 circular dependency (template/instantiate6.C). */
12923 {
12928 {
12931 }
12933 }
12937 }
12943 /* Clear out the mangled name and RTL for the instantiation. */
12947 /* The initializer must not be expanded until it is required;
12948 see [temp.inst]. */
12952 {
12955 /* Possibly limit visibility based on template args. */
12958 {
12962 }
12964 }
12967 {
12968 /* A static data member declaration is always marked
12969 external when it is declared in-class, even if an
12970 initializer is present. We mimic the non-template
12971 processing here. */
12979 }
12980 else
12981 {
12986 }
12994 /* Preserve a typedef that names a type. */
12996 {
13000 /* An alias template specialization can be dependent
13001 even if its underlying type is not. */
13003 }
13006 }
13011 }
13012 #undef RETURN
13014 out:
13015 /* Restore the file and line information. */
13019 }
13021 /* Substitute into the ARG_TYPES of a function type.
13022 If END is a TREE_CHAIN, leave it and any following types
13023 un-substituted. */
13025 static tree
13027 tree args,
13028 tree end,
13029 tsubst_flags_t complain,
13030 tree in_decl)
13031 {
13032 tree remaining_arg_types;
13036 tree default_arg;
13047 {
13048 /* For a pack expansion, perform substitution on the
13049 entire expression. Later on, we'll handle the arguments
13050 one-by-one. */
13055 /* So that we'll spin through the parameters, one by one. */
13057 else
13058 {
13059 /* We only partially substituted into the parameter
13060 pack. Our type is TYPE_PACK_EXPANSION. */
13063 }
13064 }
13077 {
13079 {
13083 }
13085 }
13086 /* DR 657. */
13090 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13091 top-level qualifiers as required. */
13094 /* We do not substitute into default arguments here. The standard
13095 mandates that they be instantiated only when needed, which is
13096 done in build_over_call. */
13100 {
13101 /* We've instantiated a template before its default arguments
13102 have been parsed. This can happen for a nested template
13103 class, and is not an error unless we require the default
13104 argument in a call of this function. */
13105 remaining_arg_types =
13108 }
13109 else
13110 remaining_arg_types =
13112 }
13115 }
13117 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13118 *not* handle the exception-specification for FNTYPE, because the
13119 initial substitution of explicitly provided template parameters
13120 during argument deduction forbids substitution into the
13121 exception-specification:
13123 [temp.deduct]
13125 All references in the function type of the function template to the
13126 corresponding template parameters are replaced by the specified tem-
13127 plate argument values. If a substitution in a template parameter or
13128 in the function type of the function template results in an invalid
13129 type, type deduction fails. [Note: The equivalent substitution in
13130 exception specifications is done only when the function is instanti-
13131 ated, at which point a program is ill-formed if the substitution
13132 results in an invalid type.] */
13134 static tree
13136 tree args,
13137 tsubst_flags_t complain,
13138 tree in_decl)
13139 {
13140 tree return_type;
13142 tree fntype;
13144 /* The TYPE_CONTEXT is not used for function/method types. */
13147 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13148 failure. */
13152 {
13153 /* Substitute the argument types. */
13165 {
13166 /* DR 1207: 'this' is in scope in the trailing return type. */
13168 }
13170 /* Substitute the return type. */
13174 {
13177 }
13178 }
13179 else
13180 /* Substitute the return type. */
13185 /* DR 486 clarifies that creation of a function type with an
13186 invalid return type is a deduction failure. */
13189 {
13191 {
13194 else
13196 }
13198 }
13199 /* And DR 657. */
13204 {
13205 /* Substitute the argument types. */
13210 }
13212 /* Construct a new type node and return it. */
13214 {
13219 }
13220 else
13221 {
13223 /* Don't pick up extra function qualifiers from the basetype. */
13226 {
13227 /* [temp.deduct]
13229 Type deduction may fail for any of the following
13230 reasons:
13232 -- Attempting to create "pointer to member of T" when T
13233 is not a class type. */
13236 r);
13238 }
13243 }
13250 }
13252 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13253 ARGS into that specification, and return the substituted
13254 specification. If there is no specification, return NULL_TREE. */
13256 static tree
13258 tree args,
13259 tsubst_flags_t complain,
13260 tree in_decl,
13262 {
13263 tree specs;
13264 tree new_specs;
13269 {
13270 /* A noexcept-specifier. */
13275 {
13276 /* Defer instantiation of noexcept-specifiers to avoid
13277 excessive instantiations (c++/49107). */
13280 {
13281 /* We already partially instantiated this member template,
13282 so combine the new args with the old. */
13287 }
13288 else
13289 {
13292 }
13293 }
13294 else
13295 new_specs = tsubst_copy_and_build
13299 }
13301 {
13304 else
13306 {
13307 tree spec;
13312 {
13313 /* Expand the pack expansion type. */
13316 in_decl);
13322 else
13323 {
13324 /* We're substituting into a member template, so
13325 we got a TYPE_PACK_EXPANSION back. Add that
13326 expansion and move on. */
13330 expanded_specs,
13331 complain);
13334 }
13335 }
13338 {
13341 else
13346 complain);
13347 }
13350 }
13351 }
13353 }
13355 /* Take the tree structure T and replace template parameters used
13356 therein with the argument vector ARGS. IN_DECL is an associated
13357 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13358 Issue error and warning messages under control of COMPLAIN. Note
13359 that we must be relatively non-tolerant of extensions here, in
13360 order to preserve conformance; if we allow substitutions that
13361 should not be allowed, we may allow argument deductions that should
13362 not succeed, and therefore report ambiguous overload situations
13363 where there are none. In theory, we could allow the substitution,
13364 but indicate that it should have failed, and allow our caller to
13365 make sure that the right thing happens, but we don't try to do this
13366 yet.
13368 This function is used for dealing with types, decls and the like;
13369 for expressions, use tsubst_expr or tsubst_copy. */
13371 tree
13373 {
13396 else
13401 /* Reuse typedefs. We need to do this to handle dependent attributes,
13402 such as attribute aligned. */
13405 {
13409 {
13410 /* DECL represents an alias template and we want to
13411 instantiate it. */
13415 }
13419 {
13423 }
13428 else
13429 /* The typedef is from a non-template context. */
13433 {
13435 r = cp_build_qualified_type_real
13439 }
13440 else
13441 {
13442 /* We don't have an instantiation yet, so drop the typedef. */
13447 }
13448 }
13465 {
13491 {
13497 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13498 needed. */
13504 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13505 with TREE_SIDE_EFFECTS that indicates this is not an integral
13506 constant expression. */
13509 {
13512 }
13515 }
13521 {
13527 /* Early in template argument deduction substitution, we don't
13528 want to reduce the level of 'auto', or it will be confused
13529 with a normal template parm in subsequent deduction. */
13541 {
13545 {
13546 /* See through ARGUMENT_PACK_SELECT arguments. */
13548 /* If the selected argument is an expansion E, that most
13549 likely means we were called from
13550 gen_elem_of_pack_expansion_instantiation during the
13551 substituting of pack an argument pack (which Ith
13552 element is a pack expansion, where I is
13553 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13554 In this case, the Ith element resulting from this
13555 substituting is going to be a pack expansion, which
13556 pattern is the pattern of E. Let's return the
13557 pattern of E, and
13558 gen_elem_of_pack_expansion_instantiation will
13559 build the resulting pack expansion from it. */
13561 {
13562 /* Make sure we aren't throwing away arg info. */
13565 }
13566 }
13567 }
13572 {
13574 /* If ARG is an argument pack, we don't actually want to
13575 perform a substitution here, because substitutions
13576 for argument packs are only done
13577 element-by-element. We can get to this point when
13578 substituting the type of a non-type template
13579 parameter pack, when that type actually contains
13580 template parameter packs from an outer template, e.g.,
13582 template<typename... Types> struct A {
13583 template<Types... Values> struct B { };
13584 }; */
13588 {
13594 return cp_build_qualified_type_real
13596 }
13598 {
13599 /* We are processing a type constructed from a
13600 template template parameter. */
13611 /* Consider this code:
13613 template <template <class> class Template>
13614 struct Internal {
13615 template <class Arg> using Bind = Template<Arg>;
13616 };
13618 template <template <class> class Template, class Arg>
13619 using Instantiate = Template<Arg>; //#0
13621 template <template <class> class Template,
13622 class Argument>
13623 using Bind =
13624 Instantiate<Internal<Template>::template Bind,
13625 Argument>; //#1
13627 When #1 is parsed, the
13628 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13629 parameter `Template' in #0 matches the
13630 UNBOUND_CLASS_TEMPLATE representing the argument
13631 `Internal<Template>::template Bind'; We then want
13632 to assemble the type `Bind<Argument>' that can't
13633 be fully created right now, because
13634 `Internal<Template>' not being complete, the Bind
13635 template cannot be looked up in that context. So
13636 we need to "store" `Bind<Argument>' for later
13637 when the context of Bind becomes complete. Let's
13638 store that in a TYPENAME_TYPE. */
13642 argvec),
13643 typename_type,
13644 complain);
13646 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13647 are resolving nested-types in the signature of a
13648 member function templates. Otherwise ARG is a
13649 TEMPLATE_DECL and is the real template to be
13650 instantiated. */
13658 complain);
13659 return cp_build_qualified_type_real
13661 }
13664 else
13665 /* TEMPLATE_PARM_INDEX. */
13667 }
13670 /* This can happen during the attempted tsubst'ing in
13671 unify. This means that we don't yet have any information
13672 about the template parameter in question. */
13675 /* If we get here, we must have been looking at a parm for a
13676 more deeply nested template. Make a new version of this
13677 template parameter, but with a lower level. */
13679 {
13684 {
13686 r = cp_build_qualified_type_real
13690 }
13697 /* Break infinite recursion when substituting the constraints
13699 else
13700 {
13711 {
13712 /* Propagate constraints on placeholders. */
13717 {
13721 }
13722 }
13725 /* We have reduced the level of the template
13726 template parameter, but not the levels of its
13727 template parameters, so canonical_type_parameter
13728 will not be able to find the canonical template
13729 template parameter for this level. Thus, we
13730 require structural equality checking to compare
13731 TEMPLATE_TEMPLATE_PARMs. */
13735 else
13739 {
13741 /* We might need to substitute into the types of non-type
13742 template parameters. */
13754 }
13755 }
13759 /* OK, now substitute the type of the non-type parameter. We
13760 couldn't do it earlier because it might be an auto parameter,
13761 and we wouldn't need to if we had an argument. */
13768 }
13771 }
13774 {
13782 {
13786 }
13789 {
13793 }
13796 {
13800 }
13806 }
13809 /* We should never be tsubsting a binfo. */
13813 /* A vector of template arguments. */
13819 {
13823 /* [temp.deduct]
13825 Type deduction may fail for any of the following
13826 reasons:
13828 -- Attempting to create a pointer to reference type.
13829 -- Attempting to create a reference to a reference type or
13830 a reference to void.
13832 Core issue 106 says that creating a reference to a reference
13833 during instantiation is no longer a cause for failure. We
13834 only enforce this check in strict C++98 mode. */
13838 {
13841 /* We keep track of the last time we issued this error
13842 message to avoid spewing a ton of messages during a
13843 single bad template instantiation. */
13846 {
13851 else
13854 }
13857 }
13861 {
13863 {
13866 type);
13867 else
13869 type);
13870 }
13872 }
13874 {
13878 }
13880 /* In C++0x, during template argument substitution, when there is an
13881 attempt to create a reference to a reference type, reference
13882 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13884 "If a template-argument for a template-parameter T names a type
13885 that is a reference to a type A, an attempt to create the type
13886 'lvalue reference to cv T' creates the type 'lvalue reference to
13887 A,' while an attempt to create the type type rvalue reference to
13888 cv T' creates the type T"
13889 */
13890 r = cp_build_reference_type
13893 else
13898 /* Will this ever be needed for TYPE_..._TO values? */
13902 }
13904 {
13907 {
13908 /* [temp.deduct]
13910 Type deduction may fail for any of the following
13911 reasons:
13913 -- Attempting to create "pointer to member of T" when T
13914 is not a class type. */
13918 }
13920 {
13924 }
13926 {
13930 }
13933 {
13934 /* The type of the implicit object parameter gets its
13935 cv-qualifiers from the FUNCTION_TYPE. */
13936 tree memptr;
13937 tree method_type
13942 complain);
13943 }
13944 else
13947 complain);
13948 }
13951 {
13952 tree fntype;
13953 tree specs;
13958 /* Substitute the exception specification. */
13966 }
13968 {
13973 /* As an optimization, we avoid regenerating the array type if
13974 it will obviously be the same as T. */
13978 /* These checks should match the ones in create_array_type_for_decl.
13980 [temp.deduct]
13982 The deduction may fail for any of the following reasons:
13984 -- Attempting to create an array with an element type that
13985 is void, a function type, or a reference type, or [DR337]
13986 an abstract class type. */
13992 {
13996 }
14004 {
14007 }
14010 }
14013 {
14025 {
14029 }
14031 {
14032 /* Normally, make_typename_type does not require that the CTX
14033 have complete type in order to allow things like:
14035 template <class T> struct S { typename S<T>::X Y; };
14037 But, such constructs have already been resolved by this
14038 point, so here CTX really should have complete type, unless
14039 it's a partial instantiation. */
14042 {
14046 }
14047 }
14054 {
14057 }
14060 {
14062 {
14066 else
14068 }
14070 {
14074 else
14076 }
14077 }
14079 return cp_build_qualified_type_real
14081 }
14084 {
14096 }
14099 {
14100 tree type;
14116 complain);
14117 }
14120 {
14121 tree type;
14132 {
14134 {
14138 }
14141 }
14152 else
14153 {
14157 /* In a template ~id could be either a complement expression
14158 or an unqualified-id naming a destructor; if instantiating
14159 it produces an expression, it's not an id-expression or
14160 member access. */
14163 }
14168 }
14171 {
14175 }
14179 {
14180 tree r;
14184 else
14192 }
14207 /* We should use one of the expression tsubsts for these codes. */
14213 }
14214 }
14216 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14217 expression on the left-hand side of the "." or "->" operator. A
14218 baselink indicates a function from a base class. Both the
14219 BASELINK_ACCESS_BINFO and the base class referenced may indicate
14220 bases of the template class, rather than the instantiated class.
14221 In addition, lookups that were not ambiguous before may be
14222 ambiguous now. Therefore, we perform the lookup again. */
14224 static tree
14227 {
14240 {
14247 }
14255 {
14260 }
14262 /* If lookup found a single function, mark it as used at this point.
14263 (If it lookup found multiple functions the one selected later by
14264 overload resolution will be marked as used at that point.) */
14272 {
14273 /* Add back the template arguments, if present. */
14279 /* Update the conversion operator type. */
14281 }
14287 {
14289 qualifying_scope,
14290 object_type);
14292 /* We need to call adjust_result_of_qualified_name_lookup in case the
14293 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14294 so that we still get virtual function binding. */
14296 }
14299 }
14301 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14302 true if the qualified-id will be a postfix-expression in-and-of
14303 itself; false if more of the postfix-expression follows the
14304 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14305 of "&". */
14307 static tree
14311 {
14312 tree expr;
14313 tree scope;
14314 tree name;
14316 tree template_args;
14321 /* Figure out what name to look up. */
14324 {
14334 }
14335 else
14336 {
14339 }
14341 /* Substitute into the qualifying scope. When there are no ARGS, we
14342 are just trying to simplify a non-dependent expression. In that
14343 case the qualifying scope may be dependent, and, in any case,
14344 substituting will not help. */
14347 {
14350 }
14351 else
14355 {
14362 }
14365 {
14367 {
14368 /* A BIT_NOT_EXPR is used to represent a destructor. */
14370 {
14374 }
14375 else
14378 }
14379 else
14383 {
14385 {
14389 }
14391 }
14392 }
14395 {
14397 scope);
14398 /* Remember that there was a reference to this entity. */
14401 }
14404 {
14410 }
14413 {
14416 complain);
14417 else
14419 }
14425 {
14426 expr = (adjust_result_of_qualified_name_lookup
14428 expr = (finish_qualified_id_expr
14432 }
14434 /* Expressions do not generally have reference type. */
14436 /* However, if we're about to form a pointer-to-member, we just
14437 want the referenced member referenced. */
14445 }
14447 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14448 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14449 for tsubst. */
14451 static tree
14454 {
14461 {
14462 /* If we had an initializer but it
14463 instantiated to nothing,
14464 value-initialize the object. This will
14465 only occur when the initializer was a
14466 pack expansion where the parameter packs
14467 used in that expansion were of length
14468 zero. */
14470 complain);
14475 }
14478 }
14480 /* Like tsubst, but deals with expressions. This function just replaces
14481 template parms; to finish processing the resultant expression, use
14482 tsubst_copy_and_build or tsubst_expr. */
14484 static tree
14486 {
14488 tree r;
14496 {
14501 {
14502 /* We get here for a use of 'this' in an NSDMI as part of a
14503 constructor call or as part of an aggregate initialization. */
14505 && ((current_function_decl
14507 || (current_class_ref
14511 /* This can happen for a parameter name used later in a function
14512 declaration (such as in a late-specified return type). Just
14513 make a dummy decl, since it's only used for its type. */
14516 /* Give it the template pattern as its context; its true context
14517 hasn't been instantiated yet and this is good enough for
14518 mangling. */
14520 }
14529 {
14530 tree enum_type;
14531 tree v;
14535 /* There is no need to substitute into namespace-scope
14536 enumerators. */
14539 /* If ARGS is NULL, then T is known to be non-dependent. */
14543 /* Unfortunately, we cannot just call lookup_name here.
14544 Consider:
14546 template <int I> int f() {
14547 enum E { a = I };
14548 struct S { void g() { E e = a; } };
14549 };
14551 When we instantiate f<7>::S::g(), say, lookup_name is not
14552 clever enough to find f<7>::a. */
14553 enum_type
14563 /* We didn't find the name. That should never happen; if
14564 name-lookup found it during preliminary parsing, we
14565 should find it again here during instantiation. */
14567 }
14572 {
14573 /* Check for a local specialization set up by
14574 tsubst_pack_expansion. */
14576 {
14580 }
14582 /* When retrieving a capture pack from a generic lambda, remove the
14583 lambda call op's own template argument list from ARGS. Only the
14584 template arguments active for the closure type should be used to
14585 retrieve the pack specialization. */
14591 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14592 tsubst_decl put in the hash table. */
14594 }
14597 {
14598 tree ctx;
14603 {
14606 {
14610 }
14612 }
14613 }
14623 {
14626 {
14627 /* First try name lookup to find the instantiation. */
14630 {
14631 /* Make sure that the one we found is the one we want. */
14637 }
14641 else
14642 {
14643 /* This can happen for a variable used in a
14644 late-specified return type of a local lambda, or for a
14645 local static or constant. Building a new VAR_DECL
14646 should be OK in all those cases. */
14649 /* Avoid infinite recursion (79640). */
14652 {
14653 /* We can't call cp_finish_decl, so handle the
14654 initializer by hand. */
14665 }
14672 }
14673 /* Remember this for subsequent uses. */
14676 }
14677 }
14678 else
14688 /* An OVERLOAD will always be a non-dependent overload set; an
14689 overload set from function scope will just be represented with an
14690 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14692 /* We must have marked any lookups as persistent. */
14708 {
14709 /* Template template argument like the following example need
14710 special treatment:
14712 template <template <class> class TT> struct C {};
14713 template <class T> struct D {
14714 template <class U> struct E {};
14715 C<E> c; // #1
14716 };
14717 D<int> d; // #2
14719 We are processing the template argument `E' in #1 for
14720 the template instantiation #2. Originally, `E' is a
14721 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14722 have to substitute this with one having context `D<int>'. */
14726 {
14727 /* When rewriting a constructor into a deduction guide, a
14728 non-dependent name can become dependent, so memtmpl<args>
14729 becomes context::template memtmpl<args>. */
14733 }
14735 }
14736 else
14737 /* Ordinary template template argument. */
14748 {
14752 }
14757 {
14766 /* We only want to compute the number of arguments. */
14769 else
14776 {
14778 /* Set TREE_USED for the benefit of -Wunused. */
14782 }
14790 {
14795 else
14801 else
14804 }
14805 else
14807 }
14809 {
14817 }
14818 /* Fall through */
14834 {
14838 }
14841 {
14842 tree object;
14843 tree name;
14848 {
14852 }
14855 {
14865 }
14870 in_decl);
14871 else
14874 }
14912 {
14916 }
14919 {
14924 }
14927 {
14931 }
14934 {
14942 }
14948 {
14955 }
14958 {
14965 }
14968 {
14975 }
14978 {
14979 /* Substituted template arguments */
14988 }
14991 {
15011 }
15036 /* Fall through. */
15039 {
15042 }
15043 else
15047 /* This is handled by tsubst_copy_and_build. */
15051 {
15055 }
15058 /* We shouldn't have built any of these during initial template
15059 generation. Instead, they should be built during instantiation
15060 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15064 {
15074 }
15092 {
15093 /* Instantiate any typedefs in the type. */
15098 }
15101 /* These can sometimes show up in a partial instantiation, but never
15102 involve template parms. */
15116 /* We shouldn't get here, but keep going if !flag_checking. */
15120 }
15121 }
15123 /* Helper function for tsubst_omp_clauses, used for instantiation of
15124 OMP_CLAUSE_DECL of clauses. */
15126 static tree
15128 tree in_decl)
15129 {
15133 /* Handle an OpenMP array section represented as a TREE_LIST (or
15134 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15135 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15136 TREE_LIST. We can handle it exactly the same as an array section
15137 (purpose, value, and a chain), even though the nomenclature
15138 (low_bound, length, etc) is different. */
15140 {
15141 tree low_bound
15147 in_decl);
15156 }
15159 /* Undo convert_from_reference tsubst_expr could have called. */
15165 }
15167 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15169 static tree
15172 {
15177 {
15183 {
15186 {
15192 }
15193 /* FALLTHRU */
15208 in_decl);
15240 {
15243 {
15250 }
15251 else
15253 }
15256 in_decl);
15262 in_decl);
15270 in_decl);
15272 {
15275 }
15280 else
15283 in_decl,
15307 }
15310 {
15320 /* tsubst_expr on SCOPE_REF results in returning
15321 finish_non_static_data_member result. Undo that here. */
15325 {
15330 {
15334 CASE_CONVERT:
15343 /* FALLTHRU */
15347 }
15348 }
15354 {
15357 {
15360 }
15361 }
15365 }
15366 }
15370 {
15375 {
15378 }
15379 }
15381 }
15383 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15385 static tree
15387 tree in_decl)
15388 {
15389 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15409 {
15412 else
15413 {
15417 }
15418 }
15423 #undef RECUR
15424 }
15426 /* Used to temporarily communicate the list of #pragma omp parallel
15427 clauses to #pragma omp for instantiation if they are combined
15428 together. */
15432 /* Substitute one OMP_FOR iterator. */
15434 static void
15439 {
15440 #define RECUR(NODE) \
15441 tsubst_expr ((NODE), args, complain, in_decl, \
15442 integral_constant_expression_p)
15449 {
15452 }
15458 {
15459 /* We need to jump through some hoops to handle declarations in the
15460 init-statement, since we might need to handle auto deduction,
15461 but we need to keep control of initialization. */
15465 }
15466 else
15467 {
15469 {
15472 {
15476 {
15480 CASE_CONVERT:
15488 {
15491 }
15492 /* FALLTHRU */
15496 }
15497 }
15498 }
15499 else
15501 }
15512 {
15514 {
15515 /* Declare the variable, but don't let that initialize it. */
15520 }
15525 {
15530 }
15531 else
15538 }
15541 {
15542 /* Declare and initialize the variable. */
15545 }
15547 {
15551 {
15553 {
15559 {
15562 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15567 }
15570 {
15572 decl);
15574 }
15577 {
15579 decl);
15581 }
15582 else
15584 }
15587 }
15589 {
15594 {
15597 }
15598 }
15599 }
15602 {
15606 }
15607 else
15611 {
15622 {
15630 }
15631 else
15637 {
15643 }
15647 {
15655 }
15656 else
15662 }
15668 #undef RECUR
15669 }
15671 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15672 of OMP_TARGET's body. */
15674 static tree
15676 {
15679 {
15688 }
15690 }
15692 /* Helper function for tsubst_expr. For decomposition declaration
15693 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15694 also the corresponding decls representing the identifiers
15695 of the decomposition declaration. Return DECL if successful
15696 or error_mark_node otherwise, set *FIRST to the first decl
15697 in the list chained through DECL_CHAIN and *CNT to the number
15698 of such decls. */
15700 static tree
15704 {
15709 decl2
15714 {
15716 {
15719 }
15736 {
15739 }
15740 else
15742 }
15745 }
15747 /* Like tsubst_copy for expressions, etc. but also does semantic
15748 processing. */
15750 tree
15753 {
15754 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15755 #define RECUR(NODE) \
15756 tsubst_expr ((NODE), args, complain, in_decl, \
15757 integral_constant_expression_p)
15760 tree r;
15761 location_t loc;
15773 {
15775 {
15776 tree_stmt_iterator i;
15780 }
15795 else
15805 {
15807 tree init;
15813 {
15823 else
15825 }
15827 {
15828 /* Don't build up decls for a variadic capture proxy, we'll
15829 instantiate the elements directly as needed. */
15831 }
15832 else
15833 {
15837 {
15838 /* By marking the declaration as instantiated, we avoid
15839 trying to instantiate it. Since instantiate_decl can't
15840 handle local variables, and since we've already done
15841 all that needs to be done, that's the right thing to
15842 do. */
15847 /* Anonymous aggregates are a special case. */
15850 {
15853 {
15857 }
15859 }
15865 {
15870 }
15871 else
15872 {
15877 {
15878 /* For __PRETTY_FUNCTION__ we have to adjust the
15879 initializer. */
15883 }
15884 else
15888 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15894 {
15896 tree first;
15902 }
15903 }
15904 }
15905 }
15908 }
15923 {
15931 {
15933 tree first;
15938 }
15939 else
15944 }
15970 else
15971 {
15978 }
15984 {
15993 }
16001 else
16009 else
16030 {
16037 }
16041 {
16043 tree label;
16050 }
16056 /* Computed goto's must be tsubst'd into. On the other hand,
16057 non-computed gotos must not be; the identifier in question
16058 will have no binding. */
16060 else
16066 {
16082 }
16087 {
16092 }
16093 else
16094 {
16099 else
16106 else
16112 else
16114 }
16118 {
16122 {
16124 /* Prevent instantiate_decl from trying to instantiate
16125 this variable. We've already done all that needs to be
16126 done. */
16129 }
16134 }
16140 {
16141 /* Local classes are not independent templates; they are
16142 instantiated along with their containing function. And this
16143 way we don't have to deal with pushing out of one local class
16144 to instantiate a member of another local class. */
16145 tree fn;
16146 /* Closures are handled by the LAMBDA_EXPR. */
16153 }
16157 {
16158 tree condition;
16161 condition =
16163 args,
16172 }
16178 in_decl);
16215 {
16230 in_decl);
16232 {
16239 }
16251 integral_constant_expression_p);
16262 else
16263 {
16271 }
16275 }
16280 /* FALLTHRU */
16287 in_decl);
16304 in_decl);
16315 {
16318 {
16319 /* For combined target teams, ensure the num_teams and
16320 thread_limit clause expressions are evaluated on the host,
16321 before entering the target construct. */
16322 tree c;
16328 {
16337 OMP_CLAUSE_FIRSTPRIVATE);
16341 }
16342 }
16343 }
16403 {
16408 {
16411 }
16417 }
16418 else
16419 {
16426 {
16429 }
16432 {
16437 {
16440 }
16446 }
16447 else
16448 {
16452 }
16455 }
16459 {
16465 {
16469 {
16474 }
16478 }
16479 else
16480 {
16485 }
16486 }
16490 {
16494 }
16514 /* If the first operand was a statement, we're done with it. */
16518 complain));
16530 integral_constant_expression_p));
16531 }
16534 out:
16537 #undef RECUR
16538 #undef RETURN
16539 }
16541 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16542 function. For description of the body see comment above
16543 cp_parser_omp_declare_reduction_exprs. */
16545 static void
16547 {
16553 tree_stmt_iterator tsi;
16564 {
16583 }
16585 {
16605 }
16606 }
16608 /* T is a postfix-expression that is not being used in a function
16609 call. Return the substituted version of T. */
16611 static tree
16613 tsubst_flags_t complain,
16614 tree in_decl)
16615 {
16619 else
16625 }
16627 /* Like tsubst but deals with expressions and performs semantic
16628 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16630 tree
16632 tree args,
16633 tsubst_flags_t complain,
16634 tree in_decl,
16637 {
16638 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16639 #define RECUR(NODE) \
16640 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16642 integral_constant_expression_p)
16645 location_t loc;
16654 /* N3276 decltype magic only applies to calls at the top level or on the
16655 right side of a comma. */
16660 {
16663 /* Fall through. */
16665 {
16666 tree decl;
16667 cp_id_kind idk;
16672 {
16675 }
16677 /* Look up the name. */
16680 /* By convention, expressions use ERROR_MARK_NODE to indicate
16681 failure, not NULL_TREE. */
16687 integral_constant_expression_p,
16695 input_location);
16699 {
16703 }
16705 }
16708 {
16709 tree object;
16719 {
16724 }
16730 {
16733 }
16734 else
16741 else
16743 }
16746 {
16750 {
16751 /* A type conversion to reference type will be enclosed in
16752 such an indirect ref, but the substitution of the cast
16753 will have also added such an indirect ref. */
16756 }
16757 else
16765 }
16768 {
16772 }
16775 {
16782 flags));
16783 }
16786 {
16790 }
16797 {
16798 tree type;
16804 {
16809 }
16815 {
16833 }
16836 }
16870 else
16872 in_decl);
16907 {
16914 tree r = build_x_binary_op
16916 op0,
16918 ? ERROR_MARK
16920 op1,
16922 ? ERROR_MARK
16930 }
16933 {
16937 }
16950 {
16959 }
16964 /* Fall through */
16967 {
16968 tree r;
16974 {
16975 /* When there are no ARGS, we are trying to evaluate a
16976 non-dependent expression from the parser. Trying to do
16977 the substitutions may not work. */
16980 }
16981 else
16982 {
16987 else
16990 /*integral_constant_expression_p=*/
16994 }
16998 else
17002 {
17004 {
17006 {
17010 }
17011 else
17015 }
17017 }
17019 }
17022 {
17032 }
17048 {
17052 tree r = build_x_modify_expr
17055 /* TREE_NO_WARNING must be set if either the expression was
17056 parenthesized or it uses an operator such as >>= rather
17057 than plain assignment. In the former case, it was already
17058 set and must be copied. In the latter case,
17059 build_x_modify_expr sets it and it must not be reset
17060 here. */
17065 }
17070 /* Remember that there was a reference to this entity. */
17077 {
17082 tree ret;
17086 else
17087 {
17091 }
17093 /* If there was an initializer in the original tree, but it
17094 instantiated to an empty list, then we should pass a
17095 non-NULL empty vector to tell build_new that it was an
17096 empty initializer() rather than no initializer. This can
17097 only happen when the initializer is a pack expansion whose
17098 parameter packs are of length zero. */
17101 else
17102 {
17106 else
17107 {
17110 }
17111 }
17117 complain);
17125 }
17128 {
17134 complain));
17135 }
17138 {
17142 integral_constant_expression_p);
17144 op0,
17147 }
17150 {
17151 tree function;
17156 tree ret;
17159 /* Internal function with no arguments. */
17163 /* When we parsed the expression, we determined whether or
17164 not Koenig lookup should be performed. */
17167 {
17170 }
17172 {
17177 }
17179 {
17180 /* Do nothing; calling tsubst_copy_and_build on an identifier
17181 would incorrectly perform unqualified lookup again.
17183 Note that we can also have an IDENTIFIER_NODE if the earlier
17184 unqualified lookup found a member function; in that case
17185 koenig_p will be false and we do want to do the lookup
17186 again to find the instantiated member function.
17188 FIXME but doing that causes c++/15272, so we need to stop
17189 using IDENTIFIER_NODE in that situation. */
17191 }
17192 else
17193 {
17195 {
17201 }
17202 else
17207 /* Avoid error about taking the address of a constructor. */
17211 in_decl,
17213 integral_constant_expression_p);
17217 }
17222 {
17227 else
17228 {
17229 /* Expand the pack expansion and push each entry onto
17230 CALL_ARGS. */
17233 {
17238 {
17243 }
17244 }
17245 else
17246 {
17247 /* A partial substitution. Add one entry. */
17249 }
17250 }
17251 }
17253 /* We do not perform argument-dependent lookup if normal
17254 lookup finds a non-function, in accordance with the
17255 expected resolution of DR 218. */
17258 /* If lookup found a member function, the Koenig lookup is
17259 not appropriate, even if an unqualified-name was used
17260 to denote the function. */
17263 /* Only do this when substitution turns a dependent call
17264 into a non-dependent call. */
17272 {
17274 {
17275 /* For backwards compatibility and good diagnostics, try
17276 the unqualified lookup again if we aren't in SFINAE
17277 context. */
17278 tree unq = (tsubst_copy_and_build
17280 integral_constant_expression_p));
17282 {
17285 }
17288 {
17289 /* In a lambda fn, we have to be careful to not
17290 introduce new this captures. Legacy code can't
17291 be using lambdas anyway, so it's ok to be
17292 stricter. */
17297 "and no declarations were found by "
17298 "argument-dependent lookup at the point "
17305 else
17309 {
17320 {
17322 input_location);
17324 "declarations in dependent base %qT are "
17330 else
17334 }
17335 else
17337 "%qD declared here, later in the "
17340 {
17343 }
17344 }
17347 }
17348 }
17350 {
17355 }
17356 }
17358 /* Remember that there was a reference to this entity. */
17362 {
17365 }
17367 /* Put back tf_decltype for the actual call. */
17372 {
17376 {
17378 "wrong number of arguments to "
17381 }
17382 else
17384 input_location),
17389 /* Unsupported internal function with arguments. */
17391 }
17394 complain);
17396 {
17411 complain);
17412 else
17413 ret = (build_new_method_call
17418 complain));
17419 }
17420 else
17423 koenig_p,
17424 complain);
17429 {
17435 {
17441 {
17443 /* The thunk location is not interesting. */
17445 }
17446 }
17447 }
17450 }
17453 {
17459 {
17461 {
17466 }
17467 else
17468 {
17473 }
17475 }
17476 else
17477 {
17480 }
17484 }
17487 {
17492 input_location));
17493 }
17496 {
17504 {
17505 /* We have pack expansions, so expand those and
17506 create a new list out of it. */
17509 tree chain;
17512 /* Expand the argument expressions. */
17520 /* Build the rest of the list. */
17525 /* Determine the number of arguments. */
17527 {
17530 }
17533 else
17534 {
17535 /* Since we only performed a partial substitution into
17536 the argument pack, we only RETURN (a single list
17537 node. */
17544 }
17546 /* Convert the argument vectors into a TREE_LIST */
17549 {
17550 /* Grab the Ith values. */
17551 i--;
17554 value
17558 /* Build the list (backwards). */
17560 }
17563 }
17579 }
17582 {
17583 tree object;
17584 tree object_type;
17585 tree member;
17586 tree r;
17590 /* Remember that there was a reference to this entity. */
17601 else
17607 {
17612 }
17616 {
17618 {
17623 {
17626 }
17628 {
17633 }
17634 }
17635 }
17638 {
17639 /* Lookup the template functions now that we know what the
17640 scope is. */
17648 {
17651 args);
17652 member = (adjust_result_of_qualified_name_lookup
17654 object_type));
17655 }
17656 else
17657 {
17659 input_location);
17661 }
17662 }
17666 {
17668 {
17672 else
17675 }
17677 }
17681 complain);
17685 }
17692 {
17700 tree r;
17705 /* digest_init will do the wrong thing if we let it. */
17709 /* We do not want to process the index of aggregate
17710 initializers as they are identifier nodes which will be
17711 looked up by digest_init. */
17717 {
17719 /* An identifier index is looked up in the type
17720 being initialized, not the current scope. */
17725 {
17726 /* Substitute into the pack expansion. */
17728 in_decl);
17732 ;
17734 /* Just move the argument into place. */
17736 else
17737 {
17738 /* Update the length of the final CONSTRUCTOR
17739 arguments vector, and note that we will need to
17740 copy.*/
17743 }
17744 }
17745 else
17747 }
17750 {
17755 {
17757 {
17762 }
17763 else
17765 }
17766 }
17772 {
17777 }
17781 }
17784 {
17787 {
17790 }
17791 else
17792 {
17795 }
17796 }
17802 {
17803 /* We don't build decls for an instantiation of a
17804 variadic capture proxy, we instantiate the elements
17805 when needed. */
17808 }
17809 /* Fall through */
17812 {
17814 /* ??? We're doing a subset of finish_id_expression here. */
17816 && !processing_template_decl
17817 && !cp_unevaluated_operand
17820 {
17822 /* Replace an evaluated use of the thread_local variable with
17823 a call to its wrapper. */
17825 }
17827 {
17831 }
17834 /* If the original type was a reference, we'll be wrapped in
17835 the appropriate INDIRECT_REF. */
17838 }
17841 {
17845 }
17848 {
17849 tree object_ptr
17856 }
17863 {
17874 }
17877 {
17883 integral_constant_expression_p);
17887 /* If the resulting list of expression statement is empty,
17888 fold it further into void_node. */
17893 }
17896 {
17914 /* For a function or variable scope, we want to use tsubst so that we
17915 don't complain about referring to an auto before deduction. */
17918 {
17919 /* Look up the parameter we want directly, as tsubst_copy
17920 doesn't do what we need. */
17926 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17929 }
17931 /* For a field, use tsubst_copy so that we look up the existing field
17932 rather than build a new one. */
17934 else
17941 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17943 /* Now that we know visibility, instantiate the type so we have a
17944 declaration of the op() for later calls to lambda_function. */
17955 }
17958 /* We can get here for a constant initializer of non-dependent type.
17959 FIXME stop folding in cp_parser_initializer_clause. */
17960 {
17962 complain);
17964 }
17968 integral_constant_expression_p));
17974 {
17979 complain));
17980 }
17986 /* Handle Objective-C++ constructs, if appropriate. */
17987 {
17988 tree subst
17993 }
17995 }
17997 #undef RECUR
17998 #undef RETURN
17999 out:
18002 }
18004 /* Verify that the instantiated ARGS are valid. For type arguments,
18005 make sure that the type's linkage is ok. For non-type arguments,
18006 make sure they are constants if they are integral or enumerations.
18007 Emit an error under control of COMPLAIN, and return TRUE on error. */
18009 static bool
18011 {
18015 {
18025 }
18027 {
18028 /* [basic.link]: A name with no linkage (notably, the name
18029 of a class or enumeration declared in a local scope)
18030 shall not be used to declare an entity with linkage.
18031 This implies that names with no linkage cannot be used as
18032 template arguments
18034 DR 757 relaxes this restriction for C++0x. */
18039 {
18040 /* DR 488 makes use of a type with no linkage cause
18041 type deduction to fail. */
18043 {
18046 else
18049 }
18051 }
18052 /* In order to avoid all sorts of complications, we do not
18053 allow variably-modified types as template arguments. */
18055 {
18059 }
18060 }
18061 /* Class template and alias template arguments should be OK. */
18063 ;
18064 /* A non-type argument of integral or enumerated type must be a
18065 constant. */
18070 {
18074 }
18076 }
18078 static bool
18080 {
18085 {
18088 }
18092 }
18094 /* We're out of SFINAE context now, so generate diagnostics for the access
18095 errors we saw earlier when instantiating D from TMPL and ARGS. */
18097 static void
18099 {
18111 }
18113 /* Instantiate the indicated variable, function, or alias template TMPL with
18114 the template arguments in TARG_PTR. */
18116 static tree
18118 {
18120 tree fndecl;
18121 tree gen_tmpl;
18122 tree spec;
18130 /* If this function is a clone, handle it specially. */
18132 {
18133 tree spec;
18134 tree clone;
18136 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18137 DECL_CLONED_FUNCTION. */
18143 /* Look for the clone. */
18147 /* We should always have found the clone by now. */
18150 }
18155 /* Check to see if we already have this specialization. */
18159 /* targ_ptr only has the innermost template args, so add the outer ones
18160 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18161 the case of a non-dependent call within a template definition). */
18162 targ_ptr = (add_outermost_template_args
18164 targ_ptr));
18166 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18167 but it doesn't seem to be on the hot path. */
18176 {
18178 {
18182 }
18184 }
18187 complain))
18190 /* We are building a FUNCTION_DECL, during which the access of its
18191 parameters and return types have to be checked. However this
18192 FUNCTION_DECL which is the desired context for access checking
18193 is not built yet. We solve this chicken-and-egg problem by
18194 deferring all checks until we have the FUNCTION_DECL. */
18197 /* Instantiation of the function happens in the context of the function
18198 template, not the context of the overload resolution we're doing. */
18200 /* If there are dependent arguments, e.g. because we're doing partial
18201 ordering, make sure processing_template_decl stays set. */
18205 {
18209 }
18215 {
18216 /* We need to determine if we're using a partial or explicit
18217 specialization now, because the type of the variable could be
18218 different. */
18224 {
18229 }
18230 }
18232 /* Substitute template parameters to obtain the specialization. */
18240 {
18243 }
18245 /* The DECL_TI_TEMPLATE should always be the immediate parent
18246 template, not the most general template. */
18250 /* Now we know the specialization, compute access previously
18251 deferred. Do no access control for inheriting constructors,
18252 as we already checked access for the inherited constructor. */
18255 {
18260 }
18263 /* If we've just instantiated the main entry point for a function,
18264 instantiate all the alternate entry points as well. We do this
18265 by cloning the instantiation of the main entry point, not by
18266 instantiating the template clones. */
18271 {
18273 {
18274 /* Remember to reinstantiate when we're out of SFINAE so the user
18275 can see the errors. */
18277 }
18279 }
18281 }
18283 /* Wrapper for instantiate_template_1. */
18285 tree
18287 {
18288 tree ret;
18293 }
18295 /* Instantiate the alias template TMPL with ARGS. Also push a template
18296 instantiation level, which instantiate_template doesn't do because
18297 functions and variables have sufficient context established by the
18298 callers. */
18300 static tree
18302 {
18309 {
18312 }
18314 args =
18322 /* We can't free this if a pending_template entry or last_error_tinst_level
18323 is pointing at it. */
18329 }
18331 /* PARM is a template parameter pack for FN. Returns true iff
18332 PARM is used in a deducible way in the argument list of FN. */
18334 static bool
18336 {
18339 {
18341 tree packs;
18347 {
18348 /* The template parameter pack is used in a function parameter
18349 pack. If this is the end of the parameter list, the
18350 template parameter pack is deducible. */
18353 else
18354 /* Otherwise, not. Well, it could be deduced from
18355 a non-pack parameter, but doing so would end up with
18356 a deduction mismatch, so don't bother. */
18358 }
18359 }
18360 /* The template parameter pack isn't used in any function parameter
18361 packs, but it might be used deeper, e.g. tuple<Args...>. */
18363 }
18365 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18366 NARGS elements of the arguments that are being used when calling
18367 it. TARGS is a vector into which the deduced template arguments
18368 are placed.
18370 Returns either a FUNCTION_DECL for the matching specialization of FN or
18371 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18372 true, diagnostics will be printed to explain why it failed.
18374 If FN is a conversion operator, or we are trying to produce a specific
18375 specialization, RETURN_TYPE is the return type desired.
18377 The EXPLICIT_TARGS are explicit template arguments provided via a
18378 template-id.
18380 The parameter STRICT is one of:
18382 DEDUCE_CALL:
18383 We are deducing arguments for a function call, as in
18384 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18385 deducing arguments for a call to the result of a conversion
18386 function template, as in [over.call.object].
18388 DEDUCE_CONV:
18389 We are deducing arguments for a conversion function, as in
18390 [temp.deduct.conv].
18392 DEDUCE_EXACT:
18393 We are deducing arguments when doing an explicit instantiation
18394 as in [temp.explicit], when determining an explicit specialization
18395 as in [temp.expl.spec], or when taking the address of a function
18396 template, as in [temp.deduct.funcaddr]. */
18398 tree
18400 tree explicit_targs,
18401 tree targs,
18404 tree return_type,
18405 unification_kind_t strict,
18409 {
18410 tree parms;
18411 tree fntype;
18424 tree tinst;
18430 full_targs = (add_outermost_template_args
18432 targs));
18437 /* In C++0x, it's possible to have a function template whose type depends
18438 on itself recursively. This is most obvious with decltype, but can also
18439 occur with enumeration scope (c++/48969). So we need to catch infinite
18440 recursion and reject the substitution at deduction time; this function
18441 will return error_mark_node for any repeated substitution.
18443 This also catches excessive recursion such as when f<N> depends on
18444 f<N-1> across all integers, and returns error_mark_node for all the
18445 substitutions back up to the initial one.
18447 This is, of course, not reentrant. */
18457 {
18458 /* [temp.deduct]
18460 The specified template arguments must match the template
18461 parameters in kind (i.e., type, nontype, template), and there
18462 must not be more arguments than there are parameters;
18463 otherwise type deduction fails.
18465 Nontype arguments must match the types of the corresponding
18466 nontype template parameters, or must be convertible to the
18467 types of the corresponding nontype parameters as specified in
18468 _temp.arg.nontype_, otherwise type deduction fails.
18470 All references in the function type of the function template
18471 to the corresponding template parameters are replaced by the
18472 specified template argument values. If a substitution in a
18473 template parameter or in the function type of the function
18474 template results in an invalid type, type deduction fails. */
18485 explicit_targs);
18487 /* Adjust any explicit template arguments before entering the
18488 substitution context. */
18489 explicit_targs
18491 complain,
18497 /* Substitute the explicit args into the function type. This is
18498 necessary so that, for instance, explicitly declared function
18499 arguments can match null pointed constants. If we were given
18500 an incomplete set of explicit args, we must not do semantic
18501 processing during substitution as we could create partial
18502 instantiations. */
18504 {
18509 /* Dig out the actual parm. */
18512 {
18515 }
18517 {
18520 }
18523 /* No explicit argument for this template parameter. */
18527 {
18528 /* Mark the argument pack as "incomplete". We could
18529 still deduce more arguments during unification.
18530 We remove this mark in type_unification_real. */
18532 {
18536 }
18538 /* We have some incomplete argument packs. */
18540 }
18541 }
18545 {
18548 }
18551 /* Ignore any access checks; we'll see them again in
18552 instantiate_template and they might have the wrong
18553 access path at this point. */
18565 /* Place the explicitly specified arguments in TARGS. */
18569 }
18571 /* Never do unification on the 'this' parameter. */
18575 {
18576 /* We're deducing for a call to the result of a template conversion
18577 function. The parms we really want are in return_type. */
18581 }
18583 {
18592 }
18594 /* We allow incomplete unification without an error message here
18595 because the standard doesn't seem to explicitly prohibit it. Our
18596 callers must be ready to deal with unification failures in any
18597 event. */
18600 /* If we aren't explaining yet, push tinst context so we can see where
18601 any errors (e.g. from class instantiations triggered by instantiation
18602 of default template arguments) come from. If we are explaining, this
18603 context is redundant. */
18605 {
18608 }
18610 /* type_unification_real will pass back any access checks from default
18611 template argument substitution. */
18623 /* Now that we have bindings for all of the template arguments,
18624 ensure that the arguments deduced for the template template
18625 parameters have compatible template parameter lists. We cannot
18626 check this property before we have deduced all template
18627 arguments, because the template parameter types of a template
18628 template parameter might depend on prior template parameters
18629 deduced after the template template parameter. The following
18630 ill-formed example illustrates this issue:
18632 template<typename T, template<T> class C> void f(C<5>, T);
18634 template<int N> struct X {};
18636 void g() {
18637 f(X<5>(), 5l); // error: template argument deduction fails
18638 }
18640 The template parameter list of 'C' depends on the template type
18641 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18642 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18643 time that we deduce 'C'. */
18646 {
18649 }
18651 /* All is well so far. Now, check:
18653 [temp.deduct]
18655 When all template arguments have been deduced, all uses of
18656 template parameters in nondeduced contexts are replaced with
18657 the corresponding deduced argument values. If the
18658 substitution results in an invalid type, as described above,
18659 type deduction fails. */
18662 {
18665 }
18667 /* Also collect access checks from the instantiation. */
18680 /* Now perform any access checks encountered during substitution. */
18687 /* If we're looking for an exact match, check that what we got
18688 is indeed an exact match. It might not be if some template
18689 parameters are used in non-deduced contexts. But don't check
18690 for an exact match if we have dependent template arguments;
18691 in that case we're doing partial ordering, and we already know
18692 that we have two candidates that will provide the actual type. */
18694 {
18698 tree sarg
18704 {
18708 }
18709 }
18711 /* After doing deduction with the inherited constructor, actually return an
18712 instantiation of the inheriting constructor. */
18718 fail:
18721 {
18723 /* Reset once we're all the way out. */
18725 }
18727 /* We can't free this if a pending_template entry or last_error_tinst_level
18728 is pointing at it. */
18734 }
18736 /* Adjust types before performing type deduction, as described in
18737 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18738 sections are symmetric. PARM is the type of a function parameter
18739 or the return type of the conversion function. ARG is the type of
18740 the argument passed to the call, or the type of the value
18741 initialized with the result of the conversion function.
18742 ARG_EXPR is the original argument expression, which may be null. */
18744 static int
18748 tree arg_expr)
18749 {
18753 {
18758 /* Swap PARM and ARG throughout the remainder of this
18759 function; the handling is precisely symmetric since PARM
18760 will initialize ARG rather than vice versa. */
18765 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18766 too, but here handle it by stripping the reference from PARM
18767 rather than by adding it to ARG. */
18775 /* Nothing else to do in this case. */
18780 }
18783 {
18784 /* [temp.deduct.call]
18786 If P is not a reference type:
18788 --If A is an array type, the pointer type produced by the
18789 array-to-pointer standard conversion (_conv.array_) is
18790 used in place of A for type deduction; otherwise,
18792 --If A is a function type, the pointer type produced by
18793 the function-to-pointer standard conversion
18794 (_conv.func_) is used in place of A for type deduction;
18795 otherwise,
18797 --If A is a cv-qualified type, the top level
18798 cv-qualifiers of A's type are ignored for type
18799 deduction. */
18804 else
18806 }
18808 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18809 reference to a cv-unqualified template parameter that does not represent a
18810 template parameter of a class template (during class template argument
18811 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18812 an lvalue, the type "lvalue reference to A" is used in place of A for type
18813 deduction. */
18820 /* try_one_overload doesn't provide an arg_expr, but
18821 functions are always lvalues. */
18825 /* [temp.deduct.call]
18827 If P is a cv-qualified type, the top level cv-qualifiers
18828 of P's type are ignored for type deduction. If P is a
18829 reference type, the type referred to by P is used for
18830 type deduction. */
18833 {
18836 }
18838 /* DR 322. For conversion deduction, remove a reference type on parm
18839 too (which has been swapped into ARG). */
18844 }
18846 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18847 template which does contain any deducible template parameters; check if
18848 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18849 unify_one_argument. */
18851 static int
18854 {
18855 tree type;
18859 else
18866 {
18870 }
18872 {
18877 }
18881 else
18883 }
18887 /* Returns true iff the expression EXPR is one from which a template
18888 argument can be deduced. In other words, if it's an undecorated
18889 use of a template non-type parameter. */
18891 static bool
18893 {
18894 /* Strip implicit conversions. */
18898 }
18900 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18901 deducible way; that is, if it has a max value of <PARM> - 1. */
18903 static bool
18905 {
18914 }
18916 /* Returns true iff the template arguments ARGS use a template parameter
18917 in a deducible way. */
18919 static bool
18921 {
18923 {
18928 else
18929 {
18936 else
18938 }
18941 }
18943 }
18945 /* Returns true iff TYPE contains any deducible references to template
18946 parameters, as per 14.8.2.5. */
18948 static bool
18950 {
18954 /* T
18955 cv-list T
18956 TT<T>
18957 TT<i>
18958 TT<> */
18963 /* T*
18964 T&
18965 T&& */
18969 /* T[integer-constant ]
18970 type [i] */
18975 /* T type ::*
18976 type T::*
18977 T T::*
18978 T (type ::*)()
18979 type (T::*)()
18980 type (type ::*)(T)
18981 type (T::*)(T)
18982 T (type ::*)(T)
18983 T (T::*)()
18984 T (T::*)(T) */
18987 || (uses_deducible_template_parms
18990 /* template-name <T> (where template-name refers to a class template)
18991 template-name <i> (where template-name refers to a class template) */
18998 /* type (T)
18999 T()
19000 T(T) */
19003 {
19012 }
19015 }
19017 /* Subroutine of type_unification_real and unify_pack_expansion to
19018 handle unification of a single P/A pair. Parameters are as
19019 for those functions. */
19021 static int
19025 {
19032 /* We can't deduce anything from this, but we might get all the
19033 template args from other function args. */
19036 /* Implicit conversions (Clause 4) will be performed on a function
19037 argument to convert it to the type of the corresponding function
19038 parameter if the parameter type contains no template-parameters that
19039 participate in template argument deduction. */
19042 /* For function parameters with no deducible template parameters,
19043 just return. We'll check non-dependent conversions later. */
19047 {
19049 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19050 | UNIFY_ALLOW_MORE_CV_QUAL
19064 }
19066 /* We only do these transformations if this is the top-level
19067 parameter_type_list in a call or declaration matching; in other
19068 situations (nested function declarators, template argument lists) we
19069 won't be comparing a type to an expression, and we don't do any type
19070 adjustments. */
19072 {
19074 {
19077 {
19078 /* [temp.deduct.type] A template-argument can be
19079 deduced from a pointer to function or pointer
19080 to member function argument if the set of
19081 overloaded functions does not contain function
19082 templates and at most one of a set of
19083 overloaded functions provides a unique
19084 match. */
19091 }
19097 }
19099 arg_strict |=
19101 }
19102 else
19107 /* For deduction from an init-list we need the actual list. */
19111 }
19113 /* for_each_template_parm callback that always returns 0. */
19115 static int
19117 {
19119 }
19121 /* for_each_template_parm any_fn callback to handle deduction of a template
19122 type argument from the type of an array bound. */
19124 static int
19126 {
19134 {
19140 }
19142 /* Keep walking. */
19144 }
19146 /* Try to deduce any not-yet-deduced template type arguments from the type of
19147 an array bound. This is handled separately from unify because 14.8.2.5 says
19148 "The type of a type parameter is only deduced from an array bound if it is
19149 not otherwise deduced." */
19151 static void
19153 {
19158 }
19160 /* Most parms like fn_type_unification.
19162 If SUBR is 1, we're being called recursively (to unify the
19163 arguments of a function or method parameter of a function
19164 template).
19166 CHECKS is a pointer to a vector of access checks encountered while
19167 substituting default template arguments. */
19169 static int
19171 tree full_targs,
19172 tree xparms,
19176 unification_kind_t strict,
19180 {
19185 tree parms;
19196 /* Reset the number of non-defaulted template arguments contained
19197 in TARGS. */
19200 again:
19208 {
19213 /* For a function parameter pack that occurs at the end of the
19214 parameter-declaration-list, the type A of each remaining
19215 argument of the call is compared with the type P of the
19216 declarator-id of the function parameter pack. */
19222 /* For a function parameter pack that does not occur at the
19223 end of the parameter-declaration-list, the type of the
19224 parameter pack is a non-deduced context. */
19231 explain_p))
19233 }
19238 {
19239 /* Unify the remaining arguments with the pack expansion type. */
19240 tree argvec;
19243 /* Allocate a TREE_VEC and copy in all of the arguments */
19248 /* Copy the parameter into parmvec. */
19254 /* Advance to the end of the list of parameters. */
19256 }
19258 /* Fail if we've reached the end of the parm list, and more args
19259 are present, and the parm list isn't variadic. */
19262 /* Fail if parms are left and they don't have default values and
19263 they aren't all deduced as empty packs (c++/57397). This is
19264 consistent with sufficient_parms_p. */
19267 {
19271 do
19272 {
19275 count++;
19277 }
19281 type_pack_p);
19282 }
19285 {
19286 tsubst_flags_t complain = (explain_p
19287 ? tf_warning_or_error
19292 {
19296 /* Clear the "incomplete" flags on all argument packs now so that
19297 substituting them into later default arguments works. */
19299 {
19302 }
19310 {
19315 }
19317 /* If this is an undeduced nontype parameter that depends on
19318 a type parameter, try another pass; its type may have been
19319 deduced from a later argument than the one from which
19320 this parameter can be deduced. */
19324 {
19327 }
19329 /* Core issue #226 (C++0x) [temp.deduct]:
19331 If a template argument has not been deduced, its
19332 default template argument, if any, is used.
19334 When we are in C++98 mode, TREE_PURPOSE will either
19335 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19336 to explicitly check cxx_dialect here. */
19338 /* OK, there is a default argument. Wait until after the
19339 conversion check to do substitution. */
19342 /* If the type parameter is a parameter pack, then it will
19343 be deduced to an empty parameter pack. */
19345 {
19346 tree arg;
19349 {
19352 }
19353 else
19360 }
19363 }
19365 /* DR 1391: All parameters have args, now check non-dependent parms for
19366 convertibility. */
19370 {
19376 /* For a function parameter pack that occurs at the end of the
19377 parameter-declaration-list, the type A of each remaining
19378 argument of the call is compared with the type P of the
19379 declarator-id of the function parameter pack. */
19385 /* For a function parameter pack that does not occur at the
19386 end of the parameter-declaration-list, the type of the
19387 parameter pack is a non-deduced context. */
19396 explain_p))
19398 }
19400 /* Now substitute into the default template arguments. */
19402 {
19426 else
19434 {
19436 /* The position of the first default template argument,
19437 is also the number of non-defaulted arguments in TARGS.
19438 Record that. */
19441 }
19442 }
19446 }
19452 }
19454 /* Subroutine of type_unification_real. Args are like the variables
19455 at the call site. ARG is an overloaded function (or template-id);
19456 we try deducing template args from each of the overloads, and if
19457 only one succeeds, we go with that. Modifies TARGS and returns
19458 true on success. */
19460 static bool
19462 tree targs,
19463 tree parm,
19464 tree arg,
19465 unification_kind_t strict,
19468 {
19475 {
19478 }
19479 else
19483 /* Handle `&x' where `x' is some static or non-static member
19484 function name. */
19490 /* Strip baselink information. */
19495 {
19496 /* If we got some explicit template args, we need to plug them into
19497 the affected templates before we try to unify, in case the
19498 explicit args will completely resolve the templates in question. */
19505 {
19518 {
19523 {
19526 }
19527 }
19530 }
19531 /* If no templates (or more than one) are fully resolved by the
19532 explicit arguments, this template-id is a non-deduced context; it
19533 could still be OK if we deduce all template arguments for the
19534 enclosing call through other arguments. */
19537 }
19540 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19541 -- but the deduction does not succeed because the expression is
19542 not just the function on its own. */
19544 else
19546 {
19551 {
19554 }
19555 }
19557 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19558 to function or pointer to member function argument if the set of
19559 overloaded functions does not contain function templates and at most
19560 one of a set of overloaded functions provides a unique match.
19562 So if we found multiple possibilities, we return success but don't
19563 deduce anything. */
19566 {
19570 {
19575 /* Don't forget explicit template arguments in a pack. */
19579 }
19580 }
19585 }
19587 /* Core DR 115: In contexts where deduction is done and fails, or in
19588 contexts where deduction is not done, if a template argument list is
19589 specified and it, along with any default template arguments, identifies
19590 a single function template specialization, then the template-id is an
19591 lvalue for the function template specialization. */
19593 tree
19595 {
19608 {
19611 }
19613 {
19616 }
19618 {
19621 }
19624 {
19628 /* If we got some explicit template args, we need to plug them into
19629 the affected templates before we try to unify, in case the
19630 explicit args will completely resolve the templates in question. */
19638 {
19651 {
19654 {
19657 }
19659 {
19662 }
19663 }
19664 }
19666 {
19674 {
19675 tree base
19678 }
19682 }
19684 /* There were no good options and at least one bad one, so let the
19685 user know what the problem is. */
19687 }
19689 }
19691 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19692 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19693 different overloads deduce different arguments for a given parm.
19694 ADDR_P is true if the expression for which deduction is being
19695 performed was of the form "& fn" rather than simply "fn".
19697 Returns 1 on success. */
19699 static int
19701 tree orig_targs,
19702 tree targs,
19703 tree parm,
19704 tree arg,
19705 unification_kind_t strict,
19709 {
19711 tree tempargs;
19717 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19718 to function or pointer to member function argument if the set of
19719 overloaded functions does not contain function templates and at most
19720 one of a set of overloaded functions provides a unique match.
19722 So if this is a template, just return success. */
19734 /* We don't copy orig_targs for this because if we have already deduced
19735 some template args from previous args, unify would complain when we
19736 try to deduce a template parameter for the same argument, even though
19737 there isn't really a conflict. */
19744 /* First make sure we didn't deduce anything that conflicts with
19745 explicitly specified args. */
19747 {
19754 /* Since we're unifying against ourselves, we will fill in
19755 template args used in the function parm list with our own
19756 template parms. Discard them. */
19759 {
19760 /* Check that the argument at each index of the deduced argument pack
19761 is equivalent to the corresponding explicitly specified argument.
19762 We may have deduced more arguments than were explicitly specified,
19763 and that's OK. */
19765 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19766 that's wrong if we deduce the same argument pack from multiple
19767 function arguments: it's only incomplete the first time. */
19780 }
19783 }
19786 {
19791 }
19794 }
19796 /* PARM is a template class (perhaps with unbound template
19797 parameters). ARG is a fully instantiated type. If ARG can be
19798 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19799 TARGS are as for unify. */
19801 static tree
19804 {
19805 tree copy_of_targs;
19815 /* We need to make a new template argument vector for the call to
19816 unify. If we used TARGS, we'd clutter it up with the result of
19817 the attempted unification, even if this class didn't work out.
19818 We also don't want to commit ourselves to all the unifications
19819 we've already done, since unification is supposed to be done on
19820 an argument-by-argument basis. In other words, consider the
19821 following pathological case:
19823 template <int I, int J, int K>
19824 struct S {};
19826 template <int I, int J>
19827 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19829 template <int I, int J, int K>
19830 void f(S<I, J, K>, S<I, I, I>);
19832 void g() {
19833 S<0, 0, 0> s0;
19834 S<0, 1, 2> s2;
19836 f(s0, s2);
19837 }
19839 Now, by the time we consider the unification involving `s2', we
19840 already know that we must have `f<0, 0, 0>'. But, even though
19841 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19842 because there are two ways to unify base classes of S<0, 1, 2>
19843 with S<I, I, I>. If we kept the already deduced knowledge, we
19844 would reject the possibility I=1. */
19848 {
19852 }
19854 /* If unification failed, we're done. */
19860 }
19862 /* Given a template type PARM and a class type ARG, find the unique
19863 base type in ARG that is an instance of PARM. We do not examine
19864 ARG itself; only its base-classes. If there is not exactly one
19865 appropriate base class, return NULL_TREE. PARM may be the type of
19866 a partial specialization, as well as a plain template type. Used
19867 by unify. */
19869 static enum template_base_result
19872 {
19874 tree binfo;
19880 {
19881 /* The type could not be completed. */
19884 }
19886 /* Walk in inheritance graph order. The search order is not
19887 important, and this avoids multiple walks of virtual bases. */
19889 {
19894 {
19895 /* If there is more than one satisfactory baseclass, then:
19897 [temp.deduct.call]
19899 If they yield more than one possible deduced A, the type
19900 deduction fails.
19902 applies. */
19904 {
19907 }
19910 }
19911 }
19915 }
19917 /* Returns the level of DECL, which declares a template parameter. */
19919 static int
19921 {
19923 {
19933 }
19935 }
19937 /* Decide whether ARG can be unified with PARM, considering only the
19938 cv-qualifiers of each type, given STRICT as documented for unify.
19939 Returns nonzero iff the unification is OK on that basis. */
19941 static int
19943 {
19949 {
19950 /* Although a CVR qualifier is ignored when being applied to a
19951 substituted template parameter ([8.3.2]/1 for example), that
19952 does not allow us to unify "const T" with "int&" because both
19953 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19954 It is ok when we're allowing additional CV qualifiers
19955 at the outer level [14.8.2.1]/3,1st bullet. */
19965 }
19976 }
19978 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19979 void
19981 {
19985 {
19988 }
19989 else
19990 {
19993 }
19994 }
19996 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19997 do { \
19998 if (unify (TP, TA, P, A, S, EP)) \
19999 return 1; \
20000 } while (0)
20002 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20003 expansion at the end of PACKED_PARMS. Returns 0 if the type
20004 deduction succeeds, 1 otherwise. STRICT is the same as in
20005 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20006 function call argument list. We'll need to adjust the arguments to make them
20007 types. SUBR tells us if this is from a recursive call to
20008 type_unification_real, or for comparing two template argument
20009 lists. */
20011 static int
20015 {
20016 tree parm
20026 /* Determine the parameter packs we will be deducing from the
20027 pattern, and record their current deductions. */
20030 {
20034 /* Determine the index and level of this parameter pack. */
20037 /* Keep track of the parameter packs and their corresponding
20038 argument packs. */
20041 }
20043 /* Loop through all of the arguments that have not yet been
20044 unified and unify each with the pattern. */
20046 {
20047 tree parm;
20051 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20052 or the element of its argument pack at the current index if
20053 this argument was explicitly specified. */
20055 {
20064 {
20067 }
20069 }
20071 /* If we had explicit template arguments, substitute them into the
20072 pattern before deduction. */
20074 {
20075 /* Some arguments might still be unspecified or dependent. */
20083 NULL_TREE);
20088 }
20089 else
20092 /* Unify the pattern with the current argument. */
20094 explain_p))
20097 /* For each parameter pack, collect the deduced value. */
20099 {
20105 }
20106 }
20108 /* Verify that the results of unification with the parameter packs
20109 produce results consistent with what we've seen before, and make
20110 the deduced argument packs available. */
20112 {
20119 /* By default keep the original deduced argument pack.
20120 If necessary, more specific code is going to update the
20121 resulting deduced argument later down in this function. */
20125 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20126 actually deduce anything. */
20134 {
20135 /* If we had fewer function args than explicit template args,
20136 just use the explicits. */
20141 }
20144 {
20145 tree result;
20146 /* Build the deduced *_ARGUMENT_PACK. */
20148 {
20151 }
20152 else
20157 /* Note the deduced argument packs for this parameter
20158 pack. */
20160 }
20164 {
20165 /* We only had the explicitly-provided arguments before, but
20166 now we have a complete set of arguments. */
20172 }
20173 else
20174 {
20180 /* Inconsistent unification of this parameter pack. */
20182 bad_old_arg,
20183 bad_new_arg);
20184 }
20185 }
20188 }
20190 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20191 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20192 parameters and return value are as for unify. */
20194 static int
20198 {
20199 tree parm_max;
20200 tree arg_max;
20204 /* Our representation of array types uses "N - 1" as the
20205 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20206 not an integer constant. We cannot unify arbitrarily
20207 complex expressions, so we eliminate the MINUS_EXPRs
20208 here. */
20212 {
20215 }
20219 {
20220 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20221 trying to unify the type of a variable with the type
20222 of a template parameter. For example:
20224 template <unsigned int N>
20225 void f (char (&) [N]);
20226 int g();
20227 void h(int i) {
20228 char a[g(i)];
20229 f(a);
20230 }
20232 Here, the type of the ARG will be "int [g(i)]", and
20233 may be a SAVE_EXPR, etc. */
20237 }
20239 /* If only one of the bounds used a MINUS_EXPR, compensate
20240 by adding one to the other bound. */
20243 integer_type_node,
20244 parm_max,
20245 integer_one_node);
20248 integer_type_node,
20249 arg_max,
20250 integer_one_node);
20254 }
20256 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20260 static pa_kind_t
20262 {
20271 else
20273 }
20275 /* Deduce the value of template parameters. TPARMS is the (innermost)
20276 set of template parameters to a template. TARGS is the bindings
20277 for those template parameters, as determined thus far; TARGS may
20278 include template arguments for outer levels of template parameters
20279 as well. PARM is a parameter to a template function, or a
20280 subcomponent of that parameter; ARG is the corresponding argument.
20281 This function attempts to match PARM with ARG in a manner
20282 consistent with the existing assignments in TARGS. If more values
20283 are deduced, then TARGS is updated.
20285 Returns 0 if the type deduction succeeds, 1 otherwise. The
20286 parameter STRICT is a bitwise or of the following flags:
20288 UNIFY_ALLOW_NONE:
20289 Require an exact match between PARM and ARG.
20290 UNIFY_ALLOW_MORE_CV_QUAL:
20291 Allow the deduced ARG to be more cv-qualified (by qualification
20292 conversion) than ARG.
20293 UNIFY_ALLOW_LESS_CV_QUAL:
20294 Allow the deduced ARG to be less cv-qualified than ARG.
20295 UNIFY_ALLOW_DERIVED:
20296 Allow the deduced ARG to be a template base class of ARG,
20297 or a pointer to a template base class of the type pointed to by
20298 ARG.
20299 UNIFY_ALLOW_INTEGER:
20300 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20301 case for more information.
20302 UNIFY_ALLOW_OUTER_LEVEL:
20303 This is the outermost level of a deduction. Used to determine validity
20304 of qualification conversions. A valid qualification conversion must
20305 have const qualified pointers leading up to the inner type which
20306 requires additional CV quals, except at the outer level, where const
20307 is not required [conv.qual]. It would be normal to set this flag in
20308 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20309 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20310 This is the outermost level of a deduction, and PARM can be more CV
20311 qualified at this point.
20312 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20313 This is the outermost level of a deduction, and PARM can be less CV
20314 qualified at this point. */
20316 static int
20319 {
20321 tree targ;
20322 tree tparm;
20324 tsubst_flags_t complain = (explain_p
20325 ? tf_warning_or_error
20328 /* I don't think this will do the right thing with respect to types.
20329 But the only case I've seen it in so far has been array bounds, where
20330 signedness is the only information lost, and I think that will be
20331 okay. */
20339 /* We can't deduce anything from this, but we might get all the
20340 template args from other function args. */
20346 /* If PARM uses template parameters, then we can't bail out here,
20347 even if ARG == PARM, since we won't record unifications for the
20348 template parameters. We might need them if we're trying to
20349 figure out which of two things is more specialized. */
20353 /* Handle init lists early, so the rest of the function can assume
20354 we're dealing with a type. */
20356 {
20361 /* Replace T with std::initializer_list<T> for deduction. */
20368 /* We can only deduce from an initializer list argument if the
20369 parameter is std::initializer_list or an array; otherwise this
20370 is a non-deduced context. */
20375 else
20376 {
20378 /* Deduction is defined in terms of a single type, so just punt
20379 on the (bizarre) std::initializer_list<T...>. */
20382 }
20385 {
20392 {
20396 /* It should only be possible to get here for a call. */
20398 elt_strict |= maybe_adjust_types_for_deduction
20401 }
20404 explain_p);
20405 }
20409 {
20410 /* Also deduce from the length of the initializer list. */
20417 }
20419 /* If the std::initializer_list<T> deduction worked, replace the
20420 deduced A with std::initializer_list<A>. */
20422 {
20427 }
20429 }
20431 /* If parm and arg aren't the same kind of thing (template, type, or
20432 expression), fail early. */
20436 /* Immediately reject some pairs that won't unify because of
20437 cv-qualification mismatches. */
20440 /* It is the elements of the array which hold the cv quals of an array
20441 type, and the elements might be template type parms. We'll check
20442 when we recurse. */
20444 /* We check the cv-qualifiers when unifying with template type
20445 parameters below. We want to allow ARG `const T' to unify with
20446 PARM `T' for example, when computing which of two templates
20447 is more specialized, for example. */
20461 {
20465 /* In a type which contains a nested-name-specifier, template
20466 argument values cannot be deduced for template parameters used
20467 within the nested-name-specifier. */
20479 /* The PARM is not one we're trying to unify. Just check
20480 to see if it matches ARG. */
20481 {
20486 else
20488 }
20495 /* Check for mixed types and values. */
20503 {
20506 {
20507 /* First try to match ARG directly. */
20509 explain_p);
20511 {
20512 /* Otherwise, look for a suitable base of ARG, as below. */
20519 }
20520 }
20521 /* ARG must be constructed from a template class or a template
20522 template parameter. */
20527 /* Deduce arguments T, i from TT<T> or TT<i>. */
20533 /* Fall through to deduce template name. */
20534 }
20538 {
20539 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20541 /* Simple cases: Value already set, does match or doesn't. */
20546 }
20547 else
20548 {
20549 /* If PARM is `const T' and ARG is only `int', we don't have
20550 a match unless we are allowing additional qualification.
20551 If ARG is `const int' and PARM is just `T' that's OK;
20552 that binds `const int' to `T'. */
20557 /* Consider the case where ARG is `const volatile int' and
20558 PARM is `const T'. Then, T should be `volatile int'. */
20559 arg = cp_build_qualified_type_real
20564 /* Simple cases: Value already set, does match or doesn't. */
20570 /* Make sure that ARG is not a variable-sized array. (Note
20571 that were talking about variable-sized arrays (like
20572 `int[n]'), rather than arrays of unknown size (like
20573 `int[]').) We'll get very confused by such a type since
20574 the bound of the array is not constant, and therefore
20575 not mangleable. Besides, such types are not allowed in
20576 ISO C++, so we can do as we please here. We do allow
20577 them for 'auto' deduction, since that isn't ABI-exposed. */
20581 /* Strip typedefs as in convert_template_argument. */
20583 }
20585 /* If ARG is a parameter pack or an expansion, we cannot unify
20586 against it unless PARM is also a parameter pack. */
20591 /* If the argument deduction results is a METHOD_TYPE,
20592 then there is a problem.
20593 METHOD_TYPE doesn't map to any real C++ type the result of
20594 the deduction can not be of that type. */
20608 {
20609 /* The PARM is not one we're trying to unify. Just check
20610 to see if it matches ARG. */
20616 }
20622 {
20627 }
20629 /* [temp.deduct.type] If, in the declaration of a function template
20630 with a non-type template-parameter, the non-type
20631 template-parameter is used in an expression in the function
20632 parameter-list and, if the corresponding template-argument is
20633 deduced, the template-argument type shall match the type of the
20634 template-parameter exactly, except that a template-argument
20635 deduced from an array bound may be of any integral type.
20636 The non-type parameter might use already deduced type parameters. */
20639 {
20643 }
20646 /* Template-parameter dependent expression. Just accept it for now.
20647 It will later be processed in convert_template_argument. */
20648 ;
20654 /* Convert the ARG to the type of PARM; the deduced non-type
20655 template argument must exactly match the types of the
20656 corresponding parameter. */
20659 {
20660 /* We haven't deduced the type of this parameter yet. */
20662 /* We deduce from array bounds in try_array_deduction. */
20664 {
20665 /* Deduce it from the non-type argument. */
20670 }
20671 else
20672 /* Try again later. */
20674 }
20675 else
20678 /* If ARG is a parameter pack or an expansion, we cannot unify
20679 against it unless PARM is also a parameter pack. */
20684 {
20687 }
20692 {
20693 /* A pointer-to-member constant can be unified only with
20694 another constant. */
20698 /* Just unify the class member. It would be useless (and possibly
20699 wrong, depending on the strict flags) to unify also
20700 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20701 arg refer to the same variable, even if through different
20702 classes. For instance:
20704 struct A { int x; };
20705 struct B : A { };
20707 Unification of &A::x and &B::x must succeed. */
20710 }
20713 {
20717 /* [temp.deduct.call]
20719 A can be another pointer or pointer to member type that can
20720 be converted to the deduced A via a qualification
20721 conversion (_conv.qual_).
20723 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20724 This will allow for additional cv-qualification of the
20725 pointed-to types if appropriate. */
20728 /* The derived-to-base conversion only persists through one
20729 level of pointers. */
20734 }
20766 /* We have already checked cv-qualification at the top of the
20767 function. */
20771 /* As far as unification is concerned, this wins. Later checks
20772 will invalidate it if necessary. */
20775 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20776 /* Type INTEGER_CST can come from ordinary constant template args. */
20788 {
20798 /* Check for pack expansions in the parameters. */
20800 {
20802 {
20804 /* We can unify against something with a trailing
20805 parameter pack. */
20807 else
20808 /* [temp.deduct.type]/9: If the template argument list of
20809 P contains a pack expansion that is not the last
20810 template argument, the entire template argument list
20811 is a non-deduced context. */
20813 }
20814 }
20816 /* If we don't have enough arguments to satisfy the parameters
20817 (not counting the pack expression at the end), or we have
20818 too many arguments for a parameter list that doesn't end in
20819 a pack expression, we can't unify. */
20825 /* Unify all of the parameters that precede the (optional)
20826 pack expression. */
20828 {
20833 }
20836 DEDUCE_EXACT,
20839 }
20847 {
20855 }
20860 {
20864 {
20865 /* First, we try to unify the PARM and ARG directly. */
20870 {
20871 /* Fallback to the special case allowed in
20872 [temp.deduct.call]:
20874 If P is a class, and P has the form
20875 template-id, then A can be a derived class of
20876 the deduced A. Likewise, if P is a pointer to
20877 a class of the form template-id, A can be a
20878 pointer to a derived class pointed to by the
20879 deduced A. */
20885 {
20886 /* Don't give the derived diagnostic if we're
20887 already dealing with the same template. */
20888 bool same_template
20894 }
20895 }
20896 }
20900 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20901 Then, we should unify `int' and `U'. */
20903 else
20904 /* There's no chance of unification succeeding. */
20909 }
20916 {
20919 tree a;
20925 /* CV qualifications for methods can never be deduced, they must
20926 match exactly. We need to check them explicitly here,
20927 because type_unification_real treats them as any other
20928 cv-qualified parameter. */
20930 && (!check_cv_quals_for_unify
20958 {
20970 }
20973 }
20976 /* Unify a pointer to member with a pointer to member function, which
20977 deduces the type of the member as a function type. */
20979 {
20980 /* Check top-level cv qualifiers */
20988 /* Determine the type of the function we are unifying against. */
20992 }
21011 /* Matched cases are handled by the ARG == PARM test above. */
21015 /* We might get a variable as a non-type template argument in parm if the
21016 corresponding parameter is type-dependent. Make any necessary
21017 adjustments based on whether arg is a reference. */
21021 {
21026 }
21027 /* Now use the normal expression code to check whether they match. */
21038 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21039 or UNDERLYING_TYPE nodes. */
21043 /* Unification fails if we hit an error node. */
21048 {
21058 }
21059 /* FALLTHRU */
21062 /* An unresolved overload is a nondeduced context. */
21066 expr:
21067 /* We must be looking at an expression. This can happen with
21068 something like:
21070 template <int I>
21071 void foo(S<I>, S<I + 2>);
21073 This is a "nondeduced context":
21075 [deduct.type]
21077 The nondeduced contexts are:
21079 --A type that is a template-id in which one or more of
21080 the template-arguments is an expression that references
21081 a template-parameter.
21083 In these cases, we assume deduction succeeded, but don't
21084 actually infer any unifications. */
21089 else
21091 }
21092 }
21093 #undef RECUR_AND_CHECK_FAILURE
21094 \f
21095 /* Note that DECL can be defined in this translation unit, if
21096 required. */
21098 static void
21100 {
21101 tree clone;
21105 }
21107 /* Called if RESULT is explicitly instantiated, or is a member of an
21108 explicitly instantiated class. */
21110 void
21112 {
21115 /* If this entity has already been written out, it's too late to
21116 make any modifications. */
21120 /* For anonymous namespace we don't need to do anything. */
21122 {
21125 }
21128 /* The TREE_PUBLIC flag for function declarations will have been
21129 set correctly by tsubst. */
21132 /* This might have been set by an earlier implicit instantiation. */
21137 else
21138 {
21141 /* Always make artificials weak. */
21144 /* For WIN32 we also want to put explicit instantiations in
21145 linkonce sections. */
21148 }
21150 /* If EXTERN_P, then this function will not be emitted -- unless
21151 followed by an explicit instantiation, at which point its linkage
21152 will be adjusted. If !EXTERN_P, then this function will be
21153 emitted here. In neither circumstance do we want
21154 import_export_decl to adjust the linkage. */
21156 }
21158 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21159 important template arguments. If any are missing, we check whether
21160 they're important by using error_mark_node for substituting into any
21161 args that were used for partial ordering (the ones between ARGS and END)
21162 and seeing if it bubbles up. */
21164 static bool
21166 {
21171 {
21174 }
21176 {
21180 }
21182 }
21184 /* Given two function templates PAT1 and PAT2, return:
21186 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21187 -1 if PAT2 is more specialized than PAT1.
21188 0 if neither is more specialized.
21190 LEN indicates the number of parameters we should consider
21191 (defaulted parameters should not be considered).
21193 The 1998 std underspecified function template partial ordering, and
21194 DR214 addresses the issue. We take pairs of arguments, one from
21195 each of the templates, and deduce them against each other. One of
21196 the templates will be more specialized if all the *other*
21197 template's arguments deduce against its arguments and at least one
21198 of its arguments *does* *not* deduce against the other template's
21199 corresponding argument. Deduction is done as for class templates.
21200 The arguments used in deduction have reference and top level cv
21201 qualifiers removed. Iff both arguments were originally reference
21202 types *and* deduction succeeds in both directions, an lvalue reference
21203 wins against an rvalue reference and otherwise the template
21204 with the more cv-qualified argument wins for that pairing (if
21205 neither is more cv-qualified, they both are equal). Unlike regular
21206 deduction, after all the arguments have been deduced in this way,
21207 we do *not* verify the deduced template argument values can be
21208 substituted into non-deduced contexts.
21210 The logic can be a bit confusing here, because we look at deduce1 and
21211 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21212 can find template arguments for pat1 to make arg1 look like arg2, that
21213 means that arg2 is at least as specialized as arg1. */
21215 int
21217 {
21230 /* Remove the this parameter from non-static member functions. If
21231 one is a non-static member function and the other is not a static
21232 member function, remove the first parameter from that function
21233 also. This situation occurs for operator functions where we
21234 locate both a member function (with this pointer) and non-member
21235 operator (with explicit first operand). */
21237 {
21242 }
21244 {
21247 {
21248 len--;
21250 }
21251 }
21253 /* If only one is a conversion operator, they are unordered. */
21257 /* Consider the return type for a conversion function */
21259 {
21262 len++;
21263 }
21265 processing_template_decl++;
21271 /* Stop when an ellipsis is seen. */
21273 {
21284 {
21285 /* When both arguments are pack expansions, we need only
21286 unify the patterns themselves. */
21290 /* This is the last comparison we need to do. */
21292 }
21294 /* DR 1847: If a particular P contains no template-parameters that
21295 participate in template argument deduction, that P is not used to
21296 determine the ordering. */
21302 {
21306 }
21309 {
21313 }
21319 {
21325 /* Setup the parameter vector, which contains only ARG1. */
21328 /* Setup the argument vector, which contains the remaining
21329 arguments. */
21338 /* We cannot deduce in the other direction, because ARG1 is
21339 a pack expansion but ARG2 is not. */
21341 }
21343 {
21349 /* Setup the parameter vector, which contains only ARG1. */
21352 /* Setup the argument vector, which contains the remaining
21353 arguments. */
21362 /* We cannot deduce in the other direction, because ARG2 is
21363 a pack expansion but ARG1 is not.*/
21365 }
21367 else
21368 {
21369 /* The normal case, where neither argument is a pack
21370 expansion. */
21377 }
21379 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21380 arg2, then arg2 is not as specialized as arg1. */
21386 /* "If, for a given type, deduction succeeds in both directions
21387 (i.e., the types are identical after the transformations above)
21388 and both P and A were reference types (before being replaced with
21389 the type referred to above):
21390 - if the type from the argument template was an lvalue reference and
21391 the type from the parameter template was not, the argument type is
21392 considered to be more specialized than the other; otherwise,
21393 - if the type from the argument template is more cv-qualified
21394 than the type from the parameter template (as described above),
21395 the argument type is considered to be more specialized than the other;
21396 otherwise,
21397 - neither type is more specialized than the other." */
21400 {
21402 {
21405 else
21407 }
21409 {
21414 }
21415 }
21418 /* We've failed to deduce something in either direction.
21419 These must be unordered. */
21422 next:
21426 /* We have already processed all of the arguments in our
21427 handing of the pack expansion type. */
21432 }
21434 /* "In most cases, all template parameters must have values in order for
21435 deduction to succeed, but for partial ordering purposes a template
21436 parameter may remain without a value provided it is not used in the
21437 types being used for partial ordering."
21439 Thus, if we are missing any of the targs1 we need to substitute into
21440 origs1, then pat2 is not as specialized as pat1. This can happen when
21441 there is a nondeduced context. */
21447 processing_template_decl--;
21449 /* If both deductions succeed, the partial ordering selects the more
21450 constrained template. */
21452 {
21457 }
21459 /* All things being equal, if the next argument is a pack expansion
21460 for one function but not for the other, prefer the
21461 non-variadic function. FIXME this is bogus; see c++/41958. */
21465 {
21468 }
21474 else
21476 }
21478 /* Determine which of two partial specializations of TMPL is more
21479 specialized.
21481 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21482 to the first partial specialization. The TREE_PURPOSE is the
21483 innermost set of template parameters for the partial
21484 specialization. PAT2 is similar, but for the second template.
21486 Return 1 if the first partial specialization is more specialized;
21487 -1 if the second is more specialized; 0 if neither is more
21488 specialized.
21490 See [temp.class.order] for information about determining which of
21491 two templates is more specialized. */
21493 static int
21495 {
21496 tree targs;
21505 /* Just like what happens for functions, if we are ordering between
21506 different template specializations, we may encounter dependent
21507 types in the arguments, and we need our dependency check functions
21508 to behave correctly. */
21512 {
21515 }
21519 {
21522 }
21525 /* If both deductions succeed, the partial ordering selects the more
21526 constrained template. */
21530 /* In the case of a tie where at least one of the templates
21531 has a parameter pack at the end, the template with the most
21532 non-packed parameters wins. */
21534 && any_deductions
21537 {
21543 /* We don't count the pack expansion at the end. */
21553 }
21556 }
21558 /* Return the template arguments that will produce the function signature
21559 DECL from the function template FN, with the explicit template
21560 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21561 also match. Return NULL_TREE if no satisfactory arguments could be
21562 found. */
21564 static tree
21566 {
21570 tree decl_arg_types;
21573 tree arg;
21577 /* Never do unification on the 'this' parameter. */
21598 }
21600 /* Return the innermost template arguments that, when applied to a partial
21601 specialization SPEC_TMPL of TMPL, yield the ARGS.
21603 For example, suppose we have:
21605 template <class T, class U> struct S {};
21606 template <class T> struct S<T*, int> {};
21608 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21609 partial specialization and the ARGS will be {double*, int}. The resulting
21610 vector will be {double}, indicating that `T' is bound to `double'. */
21612 static tree
21614 {
21616 tree spec_args
21619 tree deduced_args;
21620 tree innermost_deduced_args;
21624 {
21628 innermost_deduced_args);
21629 }
21630 else
21634 again:
21643 {
21645 {
21651 }
21653 }
21657 {
21660 }
21662 /* Verify that nondeduced template arguments agree with the type
21663 obtained from argument deduction.
21665 For example:
21667 struct A { typedef int X; };
21668 template <class T, class U> struct C {};
21669 template <class T> struct C<T, typename T::X> {};
21671 Then with the instantiation `C<A, int>', we can deduce that
21672 `T' is `A' but unify () does not check whether `typename T::X'
21673 is `int'. */
21684 /* We only need to check the innermost arguments; the other
21685 arguments will always agree. */
21690 /* Now that we have bindings for all of the template arguments,
21691 ensure that the arguments deduced for the template template
21692 parameters have compatible template parameter lists. See the use
21693 of template_template_parm_bindings_ok_p in fn_type_unification
21694 for more information. */
21699 }
21701 // Compare two function templates T1 and T2 by deducing bindings
21702 // from one against the other. If both deductions succeed, compare
21703 // constraints to see which is more constrained.
21704 static int
21706 {
21711 {
21714 }
21717 {
21720 }
21722 // If both deductions succeed, then one may be more constrained.
21727 }
21729 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21730 Return the TREE_LIST node with the most specialized template, if
21731 any. If there is no most specialized template, the error_mark_node
21732 is returned.
21734 Note that this function does not look at, or modify, the
21735 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21736 returned is one of the elements of INSTANTIATIONS, callers may
21737 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21738 and retrieve it from the value returned. */
21740 tree
21742 {
21749 {
21755 {
21756 /* Equally specialized, move to next function. If there
21757 is no next function, nothing's most specialized. */
21762 }
21763 }
21766 /* Now verify that champ is better than everything earlier in the
21767 instantiation list. */
21770 {
21773 }
21774 }
21776 processing_template_decl--;
21782 }
21784 /* If DECL is a specialization of some template, return the most
21785 general such template. Otherwise, returns NULL_TREE.
21787 For example, given:
21789 template <class T> struct S { template <class U> void f(U); };
21791 if TMPL is `template <class U> void S<int>::f(U)' this will return
21792 the full template. This function will not trace past partial
21793 specializations, however. For example, given in addition:
21795 template <class T> struct S<T*> { template <class U> void f(U); };
21797 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21798 `template <class T> template <class U> S<T*>::f(U)'. */
21800 tree
21802 {
21804 {
21807 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21808 template friend, or a FIELD_DECL for a capture pack. */
21811 }
21813 /* Look for more and more general templates. */
21815 {
21816 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21817 (See cp-tree.h for details.) */
21826 /* Stop if we run into an explicitly specialized class template. */
21833 }
21836 }
21838 /* Return the most specialized of the template partial specializations
21839 which can produce TARGET, a specialization of some class or variable
21840 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21841 a TEMPLATE_DECL node corresponding to the partial specialization, while
21842 the TREE_PURPOSE is the set of template arguments that must be
21843 substituted into the template pattern in order to generate TARGET.
21845 If the choice of partial specialization is ambiguous, a diagnostic
21846 is issued, and the error_mark_node is returned. If there are no
21847 partial specializations matching TARGET, then NULL_TREE is
21848 returned, indicating that the primary template should be used. */
21850 static tree
21852 {
21854 tree t;
21855 tree champ;
21862 {
21866 }
21868 {
21871 }
21873 {
21877 }
21878 else
21883 /* For determining which partial specialization to use, only the
21884 innermost args are interesting. */
21886 {
21889 }
21892 {
21893 tree spec_args;
21897 {
21898 /* Substitute in the template args from the enclosing class. */
21902 }
21909 {
21913 /* Keep the candidate only if the constraints are satisfied,
21914 or if we're not compiling with concepts. */
21917 {
21920 }
21921 }
21922 }
21932 {
21935 ;
21936 else
21937 {
21939 {
21942 {
21945 }
21946 }
21948 }
21949 }
21953 {
21956 {
21959 }
21960 }
21963 {
21970 else
21974 {
21979 }
21982 }
21985 }
21987 /* Explicitly instantiate DECL. */
21989 void
21991 {
21996 /* An error occurred, for which grokdeclarator has already issued
21997 an appropriate message. */
22000 {
22003 }
22009 {
22010 /* There is an asymmetry here in the way VAR_DECLs and
22011 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22012 the latter, the DECL we get back will be marked as a
22013 template instantiation, and the appropriate
22014 DECL_TEMPLATE_INFO will be set up. This does not happen for
22015 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22016 should handle VAR_DECLs as it currently handles
22017 FUNCTION_DECLs. */
22019 {
22022 }
22025 {
22028 }
22030 {
22035 }
22036 }
22038 {
22041 }
22042 else
22045 /* Check for various error cases. Note that if the explicit
22046 instantiation is valid the RESULT will currently be marked as an
22047 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22048 until we get here. */
22051 {
22052 /* DR 259 [temp.spec].
22054 Both an explicit instantiation and a declaration of an explicit
22055 specialization shall not appear in a program unless the explicit
22056 instantiation follows a declaration of the explicit specialization.
22058 For a given set of template parameters, if an explicit
22059 instantiation of a template appears after a declaration of an
22060 explicit specialization for that template, the explicit
22061 instantiation has no effect. */
22063 }
22065 {
22066 /* [temp.spec]
22068 No program shall explicitly instantiate any template more
22069 than once.
22071 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22072 the first instantiation was `extern' and the second is not,
22073 and EXTERN_P for the opposite case. */
22076 /* If an "extern" explicit instantiation follows an ordinary
22077 explicit instantiation, the template is instantiated. */
22080 }
22082 {
22085 }
22087 {
22090 }
22093 ;
22095 {
22098 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22101 }
22102 else
22110 }
22112 static void
22114 {
22120 {
22123 }
22124 }
22126 /* Called from do_type_instantiation through binding_table_foreach to
22127 do recursive instantiation for the type bound in ENTRY. */
22128 static void
22130 {
22136 }
22138 /* Called from do_type_instantiation to instantiate a member
22139 (a member function or a static member variable) of an
22140 explicitly instantiated class template. */
22141 static void
22143 {
22148 }
22150 /* Perform an explicit instantiation of template class T. STORAGE, if
22151 non-null, is the RID for extern, inline or static. COMPLAIN is
22152 nonzero if this is called from the parser, zero if called recursively,
22153 since the standard is unclear (as detailed below). */
22155 void
22157 {
22167 {
22168 tree tmpl =
22172 else
22175 }
22180 {
22183 t);
22185 }
22188 {
22190 {
22192 {
22195 "ISO C++ 1998 forbids the use of %<extern%> on "
22197 }
22198 else
22200 "ISO C++ forbids the use of %qE"
22202 }
22210 else
22211 {
22213 storage);
22215 }
22216 }
22219 {
22220 /* DR 259 [temp.spec].
22222 Both an explicit instantiation and a declaration of an explicit
22223 specialization shall not appear in a program unless the explicit
22224 instantiation follows a declaration of the explicit specialization.
22226 For a given set of template parameters, if an explicit
22227 instantiation of a template appears after a declaration of an
22228 explicit specialization for that template, the explicit
22229 instantiation has no effect. */
22231 }
22233 {
22234 /* [temp.spec]
22236 No program shall explicitly instantiate any template more
22237 than once.
22239 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22240 instantiation was `extern'. If EXTERN_P then the second is.
22241 These cases are OK. */
22248 /* If we've already instantiated the template, just return now. */
22251 }
22259 {
22260 tree tmp;
22262 /* In contrast to implicit instantiation, where only the
22263 declarations, and not the definitions, of members are
22264 instantiated, we have here:
22266 [temp.explicit]
22268 The explicit instantiation of a class template specialization
22269 implies the instantiation of all of its members not
22270 previously explicitly specialized in the translation unit
22271 containing the explicit instantiation.
22273 Of course, we can't instantiate member template classes, since
22274 we don't have any arguments for them. Note that the standard
22275 is unclear on whether the instantiation of the members are
22276 *explicit* instantiations or not. However, the most natural
22277 interpretation is that it should be an explicit instantiation. */
22293 }
22294 }
22296 /* Given a function DECL, which is a specialization of TMPL, modify
22297 DECL to be a re-instantiation of TMPL with the same template
22298 arguments. TMPL should be the template into which tsubst'ing
22299 should occur for DECL, not the most general template.
22301 One reason for doing this is a scenario like this:
22303 template <class T>
22304 void f(const T&, int i);
22306 void g() { f(3, 7); }
22308 template <class T>
22309 void f(const T& t, const int i) { }
22311 Note that when the template is first instantiated, with
22312 instantiate_template, the resulting DECL will have no name for the
22313 first parameter, and the wrong type for the second. So, when we go
22314 to instantiate the DECL, we regenerate it. */
22316 static void
22318 {
22319 /* The arguments used to instantiate DECL, from the most general
22320 template. */
22321 tree code_pattern;
22325 /* Make sure that we can see identifiers, and compute access
22326 correctly. */
22330 {
22331 tree decl_parm;
22332 tree pattern_parm;
22333 tree specs;
22347 specs);
22349 /* Merge parameter declarations. */
22352 pattern_parm
22356 {
22357 tree parm_type;
22358 tree attributes;
22363 NULL_TREE);
22369 {
22372 }
22375 }
22376 /* Merge any parameters that match with the function parameter
22377 pack. */
22379 {
22381 tree expanded_types;
22382 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22383 the parameters in this function parameter pack. */
22388 {
22389 tree parm_type;
22390 tree attributes;
22393 /* Rename the parameter to include the index. */
22402 {
22405 }
22407 }
22408 }
22409 /* Merge additional specifiers from the CODE_PATTERN. */
22413 }
22415 {
22423 }
22424 else
22428 }
22430 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22431 substituted to get DECL. */
22433 tree
22435 {
22438 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22439 for the instantiation. This is not always the most general
22440 template. Consider, for example:
22442 template <class T>
22443 struct S { template <class U> void f();
22444 template <> void f<int>(); };
22446 and an instantiation of S<double>::f<int>. We want TD to be the
22447 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22449 more general template. */
22451 /* We must also deal with friend templates. Given:
22453 template <class T> struct S {
22454 template <class U> friend void f() {};
22455 };
22457 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22458 so far as the language is concerned, but that's still
22459 where we get the pattern for the instantiation from. On
22460 other hand, if the definition comes outside the class, say:
22462 template <class T> struct S {
22463 template <class U> friend void f();
22464 };
22465 template <class U> friend void f() {}
22467 we don't need to look any further. That's what the check for
22468 DECL_INITIAL is for. */
22472 {
22473 /* The present template, TD, should not be a definition. If it
22474 were a definition, we should be using it! Note that we
22475 cannot restructure the loop to just keep going until we find
22476 a template with a definition, since that might go too far if
22477 a specialization was declared, but not defined. */
22479 /* Fetch the more general template. */
22481 }
22484 }
22486 /* Returns true if we need to instantiate this template instance even if we
22487 know we aren't going to emit it. */
22489 bool
22491 {
22492 /* We always instantiate inline functions so that we can inline them. An
22493 explicit instantiation declaration prohibits implicit instantiation of
22494 non-inline functions. With high levels of optimization, we would
22495 normally inline non-inline functions -- but we're not allowed to do
22496 that for "extern template" functions. Therefore, we check
22497 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22501 /* And we need to instantiate static data members so that
22502 their initializers are available in integral constant
22503 expressions. */
22506 }
22508 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22509 instantiate it now, modifying TREE_TYPE (fn). */
22511 void
22513 {
22516 /* Don't instantiate a noexcept-specification from template context. */
22531 {
22535 {
22550 }
22551 else
22555 }
22558 {
22561 else
22563 }
22564 }
22566 /* Produce the definition of D, a _DECL generated from a template. If
22567 DEFER_OK is true, then we don't have to actually do the
22568 instantiation now; we just have to do it sometime. Normally it is
22569 an error if this is an explicit instantiation but D is undefined.
22570 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22571 instantiated class template. */
22573 tree
22575 {
22577 tree gen_args;
22578 tree args;
22579 tree td;
22580 tree code_pattern;
22581 tree spec;
22582 tree gen_tmpl;
22590 /* This function should only be used to instantiate templates for
22591 functions and static member variables. */
22594 /* A concept is never instantiated. */
22597 /* Variables are never deferred; if instantiation is required, they
22598 are instantiated right away. That allows for better code in the
22599 case that an expression refers to the value of the variable --
22600 if the variable has a constant value the referring expression can
22601 take advantage of that fact. */
22605 /* Don't instantiate cloned functions. Instead, instantiate the
22606 functions they cloned. */
22614 /* D has already been instantiated or explicitly specialized, so
22615 there's nothing for us to do here.
22617 It might seem reasonable to check whether or not D is an explicit
22618 instantiation, and, if so, stop here. But when an explicit
22619 instantiation is deferred until the end of the compilation,
22620 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22621 the instantiation. */
22624 /* Check to see whether we know that this template will be
22625 instantiated in some other file, as with "extern template"
22626 extension. */
22629 /* In general, we do not instantiate such templates. */
22637 /* We should already have the extra args. */
22640 /* And what's in the hash table should match D. */
22644 /* This needs to happen before any tsubsting. */
22650 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22651 for the instantiation. */
22656 {
22657 /* Look up an explicit specialization, if any. */
22661 {
22664 }
22665 }
22669 /* We should never be trying to instantiate a member of a class
22670 template or partial specialization. */
22675 /* In the case of a friend template whose definition is provided
22676 outside the class, we may have too many arguments. Drop the
22677 ones we don't need. The same is true for specializations. */
22678 args = get_innermost_template_args
22682 {
22688 }
22689 else
22690 {
22695 else
22697 }
22699 /* We may be in the middle of deferred access check. Disable it now. */
22702 /* Unless an explicit instantiation directive has already determined
22703 the linkage of D, remember that a definition is available for
22704 this entity. */
22714 /* If D is a member of an explicitly instantiated class template,
22715 and no definition is available, treat it like an implicit
22716 instantiation. */
22719 {
22720 /* Leave linkage flags alone on instantiations with anonymous
22721 visibility. */
22723 {
22726 }
22728 }
22730 /* Defer all other templates, unless we have been explicitly
22731 forbidden from doing so. */
22733 template. */
22734 ! pattern_defined
22735 /* If it's OK to postpone instantiation, do so. */
22736 || defer_ok
22737 /* If this is a static data member that will be defined
22738 elsewhere, we don't want to instantiate the entire data
22739 member, but we do want to instantiate the initializer so that
22740 we can substitute that elsewhere. */
22742 /* Handle here a deleted function too, avoid generating
22743 its body (c++/61080). */
22745 {
22746 /* The definition of the static data member is now required so
22747 we must substitute the initializer. */
22751 {
22752 tree ns;
22753 tree init;
22762 args,
22765 /* If instantiating the initializer involved instantiating this
22766 again, don't call cp_finish_decl twice. */
22768 {
22769 /* Make sure the initializer is still constant, in case of
22770 circular dependency (template/instantiate6.C). */
22771 const_init
22775 LOOKUP_ONLYCONVERTING);
22776 }
22780 }
22782 /* We restore the source position here because it's used by
22783 add_pending_template. */
22789 /* [temp.explicit]
22791 The definition of a non-exported function template, a
22792 non-exported member function template, or a non-exported
22793 member function or static data member of a class template
22794 shall be present in every translation unit in which it is
22795 explicitly instantiated. */
22799 /* If we're in unevaluated context, we just wanted to get the
22800 constant value; this isn't an odr use, so don't queue
22801 a full instantiation. */
22804 /* ??? Historically, we have instantiated inline functions, even
22805 when marked as "extern template". */
22809 }
22810 /* Tell the repository that D is available in this translation unit
22811 -- and see if it is supposed to be instantiated here. */
22813 {
22814 /* In a PCH file, despite the fact that the repository hasn't
22815 requested instantiation in the PCH it is still possible that
22816 an instantiation will be required in a file that includes the
22817 PCH. */
22820 /* Instantiate inline functions so that the inliner can do its
22821 job, even though we'll not be emitting a copy of this
22822 function. */
22825 }
22828 tree fn_context;
22839 else
22840 {
22844 }
22846 /* Mark D as instantiated so that recursive calls to
22847 instantiate_decl do not try to instantiate it again. */
22850 /* Regenerate the declaration in case the template has been modified
22851 by a subsequent redeclaration. */
22854 /* We already set the file and line above. Reset them now in case
22855 they changed as a result of calling regenerate_decl_from_template. */
22859 {
22860 tree init;
22863 /* Clear out DECL_RTL; whatever was there before may not be right
22864 since we've reset the type of the declaration. */
22868 /* The initializer is placed in DECL_INITIAL by
22869 regenerate_decl_from_template so we don't need to
22870 push/pop_access_scope again here. Pull it out so that
22871 cp_finish_decl can process it. */
22876 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22877 initializer. That function will defer actual emission until
22878 we have a chance to determine linkage. */
22881 /* Enter the scope of D so that access-checking works correctly. */
22894 }
22898 {
22900 tree tmpl_parm;
22901 tree spec_parm;
22905 /* Save away the current list, in case we are instantiating one
22906 template from within the body of another. */
22909 /* Set up the list of local specializations. */
22912 /* Set up context. */
22916 else
22917 {
22919 {
22920 /* When instantiating a lambda's templated function
22921 operator, we need to push the non-lambda class scope
22922 of the lambda itself so that the nested function
22923 stack is sufficiently correct to deal with this
22924 capture. */
22926 do
22931 }
22933 }
22935 /* Some typedefs referenced from within the template code need to be
22936 access checked at template instantiation time, i.e now. These
22937 types were added to the template at parsing time. Let's get those
22938 and perform the access checks then. */
22940 args);
22942 /* Create substitution entries for the parameters. */
22946 {
22950 }
22952 {
22954 {
22957 }
22958 else
22959 {
22960 /* Register the (value) argument pack as a specialization of
22961 TMPL_PARM, then move on. */
22964 }
22965 }
22968 /* Substitute into the body of the function. */
22972 else
22973 {
22978 /* Set the current input_location to the end of the function
22979 so that finish_function knows where we are. */
22980 input_location
22983 /* Remember if we saw an infinite loop in the template. */
22984 current_function_infinite_loop
22986 }
22988 /* We don't need the local specializations any more. */
22992 /* Finish the function. */
22996 else
22997 {
23000 }
23006 }
23008 /* We're not deferring instantiation any more. */
23013 else
23019 out:
23028 }
23030 /* Run through the list of templates that we wish we could
23031 instantiate, and instantiate any we can. RETRIES is the
23032 number of times we retry pending template instantiation. */
23034 void
23036 {
23040 /* Instantiating templates may trigger vtable generation. This in turn
23041 may require further template instantiations. We place a limit here
23042 to avoid infinite loop. */
23044 {
23048 "template instantiation depth exceeds maximum of %d"
23049 " instantiating %q+D, possibly from virtual table generation"
23053 /* Pretend that we defined it. */
23056 }
23058 do
23059 {
23064 {
23069 {
23070 tree fn;
23073 {
23077 fn;
23085 }
23088 }
23089 else
23090 {
23093 {
23094 instantiation
23100 }
23104 }
23107 /* If INSTANTIATION has been instantiated, then we don't
23108 need to consider it again in the future. */
23110 else
23111 {
23114 }
23117 }
23119 }
23123 }
23125 /* Substitute ARGVEC into T, which is a list of initializers for
23126 either base class or a non-static data member. The TREE_PURPOSEs
23127 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23128 instantiate_decl. */
23130 static tree
23132 {
23136 {
23137 tree decl;
23138 tree init;
23144 {
23145 tree expr;
23146 tree arg;
23148 /* Expand the base class expansion type into separate base
23149 classes. */
23151 tf_warning_or_error,
23152 NULL_TREE);
23156 /* We'll be building separate TREE_LISTs of arguments for
23157 each base. */
23163 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23164 expand each argument in the TREE_VALUE of t. */
23171 /* VOID_TYPE_NODE is used to indicate
23172 value-initialization. */
23173 {
23176 }
23177 else
23178 {
23179 /* Substitute parameter packs into each argument in the
23180 TREE_LIST. */
23183 {
23184 tree expanded_exprs;
23186 /* Expand the argument. */
23188 expanded_exprs
23190 tf_warning_or_error,
23191 NULL_TREE);
23195 /* Prepend each of the expanded expressions to the
23196 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23198 {
23203 }
23204 }
23207 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23208 since we built them backwards. */
23210 {
23213 }
23214 }
23215 }
23218 {
23220 {
23224 }
23225 else
23226 {
23227 tree tmp;
23242 /* If we had an initializer but it instantiated to nothing,
23243 value-initialize the object. This will only occur when
23244 the initializer was a pack expansion where the parameter
23245 packs used in that expansion were of length zero. */
23248 }
23251 {
23255 }
23256 }
23257 }
23259 }
23261 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23263 static void
23265 {
23270 else
23272 }
23274 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23275 is the instantiation (which should have been created with
23276 start_enum) and ARGS are the template arguments to use. */
23278 static void
23280 {
23281 tree e;
23287 {
23288 tree value;
23289 tree decl;
23292 /* Note that in a template enum, the TREE_VALUE is the
23293 CONST_DECL, not the corresponding INTEGER_CST. */
23298 /* Give this enumeration constant the correct access. */
23301 /* Actually build the enumerator itself. Here we're assuming that
23302 enumerators can't have dependent attributes. */
23305 }
23315 }
23317 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23318 its type -- but without substituting the innermost set of template
23319 arguments. So, innermost set of template parameters will appear in
23320 the type. */
23322 tree
23324 {
23325 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23327 }
23329 /* Return truthvalue if we're processing a template different from
23330 the last one involved in diagnostics. */
23331 bool
23333 {
23335 }
23337 /* Remember current template involved in diagnostics. */
23338 void
23340 {
23342 }
23346 {
23348 }
23350 /* Return TRUE if current_function_decl is being instantiated, false
23351 otherwise. */
23353 bool
23355 {
23358 }
23360 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23361 type. Return zero for ok, nonzero for disallowed. Issue error and
23362 warning messages under control of COMPLAIN. */
23364 static int
23366 {
23381 /* A bound template template parm could later be instantiated to have a valid
23382 nontype parm type via an alias template. */
23388 {
23391 else
23393 type);
23394 }
23396 }
23398 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23399 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23401 static bool
23403 {
23404 tree scope;
23406 /* [temp.dep.type]
23408 A type is dependent if it is:
23410 -- a template parameter. Template template parameters are types
23411 for us (since TYPE_P holds true for them) so we handle
23412 them here. */
23416 /* -- a qualified-id with a nested-name-specifier which contains a
23417 class-name that names a dependent type or whose unqualified-id
23418 names a dependent type. */
23422 /* An alias template specialization can be dependent even if the
23423 resulting type is not. */
23427 /* -- a cv-qualified type where the cv-unqualified type is
23428 dependent.
23429 No code is necessary for this bullet; the code below handles
23430 cv-qualified types, and we don't want to strip aliases with
23431 TYPE_MAIN_VARIANT because of DR 1558. */
23432 /* -- a compound type constructed from any dependent type. */
23442 {
23443 tree arg_type;
23448 arg_type;
23453 {
23454 /* A value-dependent noexcept-specifier makes the type dependent. */
23459 }
23461 }
23462 /* -- an array type constructed from any dependent type or whose
23463 size is specified by a constant expression that is
23464 value-dependent.
23466 We checked for type- and value-dependence of the bounds in
23467 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23469 {
23474 }
23476 /* -- a template-id in which either the template name is a template
23477 parameter ... */
23480 /* ... or any of the template arguments is a dependent type or
23481 an expression that is type-dependent or value-dependent. */
23483 && (any_dependent_template_arguments_p
23487 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23488 dependent; if the argument of the `typeof' expression is not
23489 type-dependent, then it should already been have resolved. */
23495 /* A template argument pack is dependent if any of its packed
23496 arguments are. */
23498 {
23504 }
23506 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23507 be template parameters. */
23514 /* The standard does not specifically mention types that are local
23515 to template functions or local classes, but they should be
23516 considered dependent too. For example:
23518 template <int I> void f() {
23519 enum E { a = I };
23520 S<sizeof (E)> s;
23521 }
23523 The size of `E' cannot be known until the value of `I' has been
23524 determined. Therefore, `E' must be considered dependent. */
23528 /* Don't use type_dependent_expression_p here, as it can lead
23529 to infinite recursion trying to determine whether a lambda
23530 nested in a lambda is dependent (c++/47687). */
23534 && (any_dependent_template_arguments_p
23538 /* Other types are non-dependent. */
23540 }
23542 /* Returns TRUE if TYPE is dependent, in the sense of
23543 [temp.dep.type]. Note that a NULL type is considered dependent. */
23545 bool
23547 {
23548 /* If there are no template parameters in scope, then there can't be
23549 any dependent types. */
23551 {
23552 /* If we are not processing a template, then nobody should be
23553 providing us with a dependent type. */
23557 }
23559 /* If the type is NULL, we have not computed a type for the entity
23560 in question; in that case, the type is dependent. */
23564 /* Erroneous types can be considered non-dependent. */
23568 /* Getting here with global_type_node means we improperly called this
23569 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23572 /* If we have not already computed the appropriate value for TYPE,
23573 do so now. */
23575 {
23578 }
23581 }
23583 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23584 lookup. In other words, a dependent type that is not the current
23585 instantiation. */
23587 bool
23589 {
23592 }
23594 /* T is a SCOPE_REF; return whether we need to consider it
23595 instantiation-dependent so that we can check access at instantiation
23596 time even though we know which member it resolves to. */
23598 static bool
23600 {
23606 else
23608 }
23610 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23611 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23612 expression. */
23614 /* Note that this predicate is not appropriate for general expressions;
23615 only constant expressions (that satisfy potential_constant_expression)
23616 can be tested for value dependence. */
23618 bool
23620 {
23624 /* A name declared with a dependent type. */
23629 {
23631 /* A dependent member function of the current instantiation. */
23635 /* A dependent member function of the current instantiation. */
23642 /* A name that has not been looked up -- must be dependent. */
23646 /* A non-type template parm. */
23650 /* A non-type template parm. */
23656 /* A constant with literal type and is initialized
23657 with an expression that is value-dependent.
23659 Note that a non-dependent parenthesized initializer will have
23660 already been replaced with its constant value, so if we see
23661 a TREE_LIST it must be dependent. */
23665 /* cp_finish_decl doesn't fold reference initializers. */
23671 {
23675 }
23683 /* These expressions are value-dependent if the type to which
23684 the cast occurs is dependent or the expression being casted
23685 is value-dependent. */
23686 {
23692 /* A functional cast has a list of operands. */
23695 {
23696 /* If there are no operands, it must be an expression such
23697 as "int()". This should not happen for aggregate types
23698 because it would form non-constant expressions. */
23703 }
23709 }
23714 /* FALLTHRU */
23717 /* A `sizeof' expression is value-dependent if the operand is
23718 type-dependent or is a pack expansion. */
23727 /* An 'encode' expression is value-dependent if the operand is
23728 type-dependent. */
23737 /* All instantiation-dependent expressions should also be considered
23738 value-dependent. */
23746 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23747 is value-dependent. */
23748 {
23757 }
23760 {
23764 }
23775 {
23779 }
23782 /* Treat all requires-expressions as value-dependent so
23783 we don't try to fold them. */
23790 {
23797 {
23799 /* In a call to a constexpr member function, look through the
23800 implicit ADDR_EXPR on the object argument so that it doesn't
23801 cause the call to be considered value-dependent. We also
23802 look through it in potential_constant_expression. */
23809 }
23811 }
23814 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23815 type-dependent. */
23820 {
23822 tree val;
23829 }
23832 /* Treat a GNU statement expression as dependent to avoid crashing
23833 under instantiate_non_dependent_expr; it can't be constant. */
23837 /* A constant expression is value-dependent if any subexpression is
23838 value-dependent. */
23840 {
23847 {
23851 {
23854 /* In some cases, some of the operands may be missing.
23855 (For example, in the case of PREDECREMENT_EXPR, the
23856 amount to increment by may be missing.) That doesn't
23857 make the expression dependent. */
23860 }
23861 }
23865 }
23867 }
23869 /* The expression is not value-dependent. */
23871 }
23873 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23874 [temp.dep.expr]. Note that an expression with no type is
23875 considered dependent. Other parts of the compiler arrange for an
23876 expression with type-dependent subexpressions to have no type, so
23877 this function doesn't have to be fully recursive. */
23879 bool
23881 {
23888 /* An unresolved name is always dependent. */
23894 /* A fold expression is type-dependent. */
23901 /* Some expression forms are never type-dependent. */
23915 /* The types of these expressions depends only on the type to which
23916 the cast occurs. */
23925 /* The types of these expressions depends only on the type created
23926 by the expression. */
23929 {
23930 /* For NEW_EXPR tree nodes created inside a template, either
23931 the object type itself or a TREE_LIST may appear as the
23932 operand 1. */
23935 /* This is an array type. We need to check array dimensions
23936 as well. */
23938 || value_dependent_expression_p
23940 else
23942 }
23945 {
23949 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23950 contains an identifier associated by name lookup with one or more
23951 declarations declared with a dependent type, or...a
23952 nested-name-specifier or qualified-id that names a member of an
23953 unknown specialization. */
23956 }
23966 {
23967 tree elt;
23971 {
23974 }
23976 }
23978 /* A static data member of the current instantiation with incomplete
23979 array type is type-dependent, as the definition and specializations
23980 can have different bounds. */
23987 /* An array of unknown bound depending on a variadic parameter, eg:
23989 template<typename... Args>
23990 void foo (Args... args)
23991 {
23992 int arr[] = { args... };
23993 }
23995 template<int... vals>
23996 void bar ()
23997 {
23998 int arr[] = { vals... };
23999 }
24001 If the array has no length and has an initializer, it must be that
24002 we couldn't determine its length in cp_complete_array_type because
24003 it is dependent. */
24011 /* A function or variable template-id is type-dependent if it has any
24012 dependent template arguments. */
24016 {
24017 /* Consider the innermost template arguments, since those are the ones
24018 that come from the template-id; the template arguments for the
24019 enclosing class do not make it type-dependent unless they are used in
24020 the type of the decl. */
24022 && (any_dependent_template_arguments_p
24026 /* Otherwise, if the decl isn't from a dependent scope, it can't be
24027 type-dependent. Checking this is important for functions with auto
24028 return type, which looks like a dependent type. */
24035 {
24039 }
24040 }
24042 /* Always dependent, on the number of arguments if nothing else. */
24047 {
24052 {
24058 }
24059 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24064 {
24069 }
24072 {
24079 }
24089 }
24093 /* Dependent type attributes might not have made it from the decl to
24094 the type yet. */
24100 }
24102 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24103 type-dependent if the expression refers to a member of the current
24104 instantiation and the type of the referenced member is dependent, or the
24105 class member access expression refers to a member of an unknown
24106 specialization.
24108 This function returns true if the OBJECT in such a class member access
24109 expression is of an unknown specialization. */
24111 bool
24113 {
24114 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24115 dependent. */
24120 }
24122 /* walk_tree callback function for instantiation_dependent_expression_p,
24123 below. Returns non-zero if a dependent subexpression is found. */
24125 static tree
24128 {
24130 {
24131 /* We don't have to worry about decltype currently because decltype
24132 of an instantiation-dependent expr is a dependent type. This
24133 might change depending on the resolution of DR 1172. */
24136 }
24139 {
24140 /* Don't treat an argument list as dependent just because it has no
24141 TREE_TYPE. */
24149 /* Handle expressions with type operands. */
24154 {
24159 {
24162 else
24163 {
24166 }
24167 }
24169 }
24173 /* In a template, finish_class_member_access_expr creates a
24174 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24175 type-dependent, so that we can check access control at
24176 instantiation time (PR 42277). See also Core issue 1273. */
24183 else
24186 /* Treat statement-expressions as dependent. */
24190 /* Treat requires-expressions as dependent. */
24195 /* Treat calls to function concepts as dependent. */
24201 /* And variable concepts. */
24208 }
24212 else
24214 }
24216 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24217 sense defined by the ABI:
24219 "An expression is instantiation-dependent if it is type-dependent
24220 or value-dependent, or it has a subexpression that is type-dependent
24221 or value-dependent."
24223 Except don't actually check value-dependence for unevaluated expressions,
24224 because in sizeof(i) we don't care about the value of i. Checking
24225 type-dependence will in turn check value-dependence of array bounds/template
24226 arguments as needed. */
24228 bool
24230 {
24231 tree result;
24242 }
24244 /* As above, but also check value-dependence of the expression as a whole. */
24246 bool
24248 {
24251 }
24253 /* Like type_dependent_expression_p, but it also works while not processing
24254 a template definition, i.e. during substitution or mangling. */
24256 bool
24258 {
24264 }
24266 /* Returns TRUE if ARGS contains a type-dependent expression. */
24268 bool
24270 {
24272 tree arg;
24275 {
24278 }
24280 }
24282 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24283 expressions) contains any type-dependent expressions. */
24285 bool
24287 {
24293 }
24295 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24296 expressions) contains any value-dependent expressions. */
24298 bool
24300 {
24306 }
24308 /* Returns TRUE if the ARG (a template argument) is dependent. */
24310 bool
24312 {
24316 /* Assume a template argument that was wrongly written by the user
24317 is dependent. This is consistent with what
24318 any_dependent_template_arguments_p [that calls this function]
24319 does. */
24329 {
24332 /* A member template of a dependent class is not necessarily
24333 type-dependent, but it is a dependent template argument because it
24334 will be a member of an unknown specialization to that template. */
24337 }
24339 {
24343 {
24346 }
24349 }
24352 else
24355 }
24357 /* Returns true if ARGS (a collection of template arguments) contains
24358 any types that require structural equality testing. */
24360 bool
24362 {
24372 {
24375 {
24381 {
24382 /* Look inside the argument pack. */
24385 }
24388 {
24401 }
24402 }
24403 }
24406 }
24408 /* Returns true if ARGS (a collection of template arguments) contains
24409 any dependent arguments. */
24411 bool
24413 {
24423 {
24428 }
24431 }
24433 /* Returns TRUE if the template TMPL is type-dependent. */
24435 bool
24437 {
24439 {
24444 }
24446 /* Template template parameters are dependent. */
24450 /* So are names that have not been looked up. */
24454 }
24456 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24458 bool
24460 {
24463 }
24465 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24466 are dependent. */
24468 bool
24470 {
24477 {
24499 {
24503 }
24507 {
24511 {
24516 }
24517 }
24518 }
24521 }
24523 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24524 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24525 no such TYPE can be found. Note that this function peers inside
24526 uninstantiated templates and therefore should be used only in
24527 extremely limited situations. ONLY_CURRENT_P restricts this
24528 peering to the currently open classes hierarchy (which is required
24529 when comparing types). */
24531 tree
24533 {
24534 tree scope;
24535 tree name;
24536 tree decl;
24538 tree pushed_scope;
24539 tree result;
24544 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24545 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24546 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24547 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24548 identifier of the TYPENAME_TYPE anymore.
24549 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24550 TYPENAME_TYPE instead, we avoid messing up with a possible
24551 typedef variant case. */
24554 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24555 it first before we can figure out what NAME refers to. */
24557 {
24559 /* Given a class template A with a dependent base with nested type C,
24560 typedef typename A::C::C C will land us here, as trying to resolve
24561 the initial A::C leads to the local C typedef, which leads back to
24562 A::C::C. So we break the recursion now. */
24564 else
24566 }
24567 /* If we don't know what SCOPE refers to, then we cannot resolve the
24568 TYPENAME_TYPE. */
24571 /* If this is a typedef, we don't want to look inside (c++/11987). */
24574 /* If SCOPE isn't the template itself, it will not have a valid
24575 TYPE_FIELDS list. */
24577 /* scope is either the template itself or a compatible instantiation
24578 like X<T>, so look up the name in the original template. */
24580 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24582 /* If scope has no fields, it can't be a current instantiation. Check this
24583 before currently_open_class to avoid infinite recursion (71515). */
24586 /* If the SCOPE is not the current instantiation, there's no reason
24587 to look inside it. */
24590 /* Enter the SCOPE so that name lookup will be resolved as if we
24591 were in the class definition. In particular, SCOPE will no
24592 longer be considered a dependent type. */
24594 /* Look up the declaration. */
24596 tf_warning_or_error);
24600 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24601 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24606 {
24610 }
24613 {
24614 tree tmpl;
24615 tree args;
24616 /* Obtain the template and the arguments. */
24619 /* Instantiate the template. */
24625 }
24627 /* Leave the SCOPE. */
24631 /* If we failed to resolve it, return the original typename. */
24635 /* If lookup found a typename type, resolve that too. */
24637 {
24638 /* Ill-formed programs can cause infinite recursion here, so we
24639 must catch that. */
24643 }
24645 /* Qualify the resulting type. */
24651 }
24653 /* EXPR is an expression which is not type-dependent. Return a proxy
24654 for EXPR that can be used to compute the types of larger
24655 expressions containing EXPR. */
24657 tree
24659 {
24660 tree inner_expr;
24662 /* When checking, try to get a constant value for all non-dependent
24663 expressions in order to expose bugs in *_dependent_expression_p
24664 and constexpr. This can affect code generation, see PR70704, so
24665 only do this for -fchecking=2. */
24668 /* Don't do this during nsdmi parsing as it can lead to
24669 unexpected recursive instantiations. */
24671 /* Don't do this during concept expansion either and for
24672 the same reason. */
24676 /* Preserve OVERLOADs; the functions must be available to resolve
24677 types. */
24688 /* There is no need to return a proxy for a variable. */
24691 /* Preserve string constants; conversions from string constants to
24692 "char *" are allowed, even though normally a "const char *"
24693 cannot be used to initialize a "char *". */
24696 /* Preserve void and arithmetic constants, as an optimization -- there is no
24697 reason to create a new node. */
24702 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24703 There is at least one place where we want to know that a
24704 particular expression is a throw-expression: when checking a ?:
24705 expression, there are special rules if the second or third
24706 argument is a throw-expression. */
24710 /* Don't wrap an initializer list, we need to be able to look inside. */
24714 /* Don't wrap a dummy object, we need to be able to test for it. */
24733 /* If the type is unknown, it can't really be non-dependent */
24736 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24738 }
24740 /* ARGS is a vector of expressions as arguments to a function call.
24741 Replace the arguments with equivalent non-dependent expressions.
24742 This modifies ARGS in place. */
24744 void
24746 {
24748 tree arg;
24751 {
24755 }
24756 }
24758 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24759 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24760 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24762 static tree
24764 {
24778 }
24780 tree
24782 {
24784 }
24786 tree
24788 {
24790 }
24792 /* Return a C++17 deduction placeholder for class template TMPL. */
24794 tree
24796 {
24800 }
24802 /* Make a "constrained auto" type-specifier. This is an
24803 auto type with constraints that must be associated after
24804 deduction. The constraint is formed from the given
24805 CONC and its optional sequence of arguments, which are
24806 non-null if written as partial-concept-id. */
24808 tree
24810 {
24813 /* Build the constraint. */
24821 /* Our canonical type depends on the constraint. */
24824 /* Attach the constraint to the type declaration. */
24827 }
24829 /* Given type ARG, return std::initializer_list<ARG>. */
24831 static tree
24833 {
24837 {
24841 }
24847 }
24849 /* Replace auto in TYPE with std::initializer_list<auto>. */
24851 static tree
24853 {
24860 }
24862 /* Hash traits for hashing possibly constrained 'auto'
24863 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24866 {
24869 };
24871 /* Hash the 'auto' T. */
24873 inline hashval_t
24875 {
24877 /* Matching constrained-type-specifiers denote the same template
24878 parameter, so hash the constraint. */
24880 else
24881 /* But unconstrained autos are all separate, so just hash the pointer. */
24883 }
24885 /* Compare two 'auto's. */
24889 {
24896 /* Two unconstrained autos are distinct. */
24901 }
24903 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24904 constrained) auto, add it to the vector. */
24906 static int
24908 {
24911 {
24912 /* All the autos were built with index 0; fix that up now. */
24916 /* If this is a repeated constrained-type-specifier, use the index we
24917 chose before. */
24919 else
24920 {
24921 /* Otherwise this is new, so use the current count. */
24924 }
24926 }
24928 /* Always keep walking. */
24930 }
24932 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24933 says they can appear anywhere in the type. */
24935 static tree
24937 {
24946 {
24951 }
24954 }
24956 /* The stem for deduction guide names. */
24959 /* Return the name for a deduction guide for class template TMPL. */
24961 tree
24963 {
24974 }
24976 /* True if NAME is the name of a deduction guide. */
24978 bool
24980 {
24984 }
24986 /* True if FN is a deduction guide. */
24988 bool
24990 {
24995 }
24997 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24999 bool
25001 {
25008 }
25010 /* True if FN is a guide generated from a constructor template. */
25012 bool
25014 {
25019 {
25022 }
25024 }
25026 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25027 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25028 template parameter types. Note that the handling of template template
25029 parameters relies on current_template_parms being set appropriately for the
25030 new template. */
25032 static tree
25035 {
25038 tree newtype;
25041 {
25048 }
25049 else
25053 tree newdecl
25058 tree newidx;
25061 {
25071 {
25076 // First create a copy (ttargs) of tsubst_args with an
25077 // additional level for the template template parameter's own
25078 // template parameters (ttparms).
25079 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25087 // Substitute ttargs into ttparms to fix references to
25088 // other template parameters.
25090 complain);
25091 // Now substitute again with args based on tparms, to reduce
25092 // the level of the ttparms.
25095 complain);
25096 // Finally, tack the adjusted parms onto tparms.
25098 current_template_parms);
25100 }
25101 }
25102 else
25103 {
25105 tree newconst
25117 }
25120 }
25122 /* Returns a C++17 class deduction guide template based on the constructor
25123 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25124 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25126 static tree
25128 {
25132 location_t loc;
25135 {
25139 {
25142 }
25143 else
25153 }
25154 else
25155 {
25159 tree fn_tmpl;
25161 {
25164 }
25165 else
25169 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25170 fully specialized args for the enclosing class. Strip those off, as
25171 the deduction guide won't have those template parameters. */
25174 /* Discard the 'this' parameter. */
25182 {
25185 /* For a member template constructor, we need to flatten the two
25186 template parameter lists into one, and then adjust the function
25187 signature accordingly. This gets...complicated. */
25191 /* For a member template we should have two levels of parms/args, one
25192 for the class and one for the constructor. We stripped
25193 specialized args for further enclosing classes above. */
25197 /* Template args for translating references to the two-level template
25198 parameters into references to the one-level template parameters we
25199 are creating. */
25204 /* Template parms for the constructor template. */
25207 /* Template parms for the class template. */
25211 /* Template parms for the deduction guide start as a copy of the
25212 template parms for the class. We set current_template_parms for
25213 lookup_template_class_1. */
25219 /* Now we need to rewrite the constructor parms to append them to the
25220 class parms. */
25222 {
25237 }
25239 /* Now we have a final set of template parms to substitute into the
25240 function signature. */
25250 }
25251 }
25254 {
25255 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25259 }
25263 FUNCTION_DECL,
25280 }
25282 /* Deduce template arguments for the class template placeholder PTYPE for
25283 template TMPL based on the initializer INIT, and return the resulting
25284 type. */
25286 static tree
25288 tsubst_flags_t complain)
25289 {
25291 {
25292 /* We should have handled this in the caller. */
25298 }
25310 else
25321 /* Prune explicit deduction guides in copy-initialization context. */
25323 {
25329 {
25330 /* Found a nonconverting guide, prune the candidates. */
25337 }
25338 }
25343 {
25346 }
25350 // FIXME cache artificial deduction guides
25353 {
25358 else
25362 }
25365 {
25374 {
25379 else
25381 }
25382 }
25385 {
25387 " of %qT, as it has no non-explicit deduction guides or "
25390 }
25396 {
25402 }
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. */
25413 tree
25415 {
25417 tf_warning_or_error,
25418 adc_unspecified);
25419 }
25421 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25422 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25423 The CONTEXT determines the context in which auto deduction is performed
25424 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25425 OUTER_TARGS are used during template argument deduction
25426 (context == adc_unify) to properly substitute the result, and is ignored
25427 in other contexts.
25429 For partial-concept-ids, extra args may be appended to the list of deduced
25430 template arguments prior to determining constraint satisfaction. */
25432 tree
25436 {
25437 tree targs;
25444 /* Defining a subset of type-dependent expressions that we can deduce
25445 from ahead of time isn't worth the trouble. */
25449 /* C++17 class template argument deduction. */
25453 /* Nothing we can do with this, even in deduction context. */
25456 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25457 with either a new invented type template parameter U or, if the
25458 initializer is a braced-init-list (8.5.4), with
25459 std::initializer_list<U>. */
25461 {
25466 else
25467 {
25469 {
25473 "for deduction to %<std::initializer_list%>, use copy-"
25475 }
25477 }
25478 }
25489 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25490 and initializer has array type, deduce cv-qualified array type. */
25492 complain);
25494 {
25503 {
25507 }
25508 }
25509 else
25510 {
25512 tree tparms;
25516 else
25517 {
25521 }
25528 {
25530 /* Try again at instantiation time. */
25534 /* If type is error_mark_node a diagnostic must have been
25535 emitted by now. Also, having a mention to '<type error>'
25536 in the diagnostic is not really useful to the user. */
25537 {
25541 else
25546 }
25548 }
25549 }
25551 /* Check any placeholder constraints against the deduced type. */
25554 {
25555 /* Use the deduced type to check the associated constraints. If we
25556 have a partial-concept-id, rebuild the argument list so that
25557 we check using the extra arguments. */
25561 {
25564 }
25565 else
25568 {
25570 {
25572 {
25590 }
25592 }
25594 }
25595 }
25601 }
25603 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25604 result. */
25606 tree
25608 {
25610 {
25616 /* In an abbreviated function template we didn't know we were dealing
25617 with a function template when we saw the auto return type, so update
25618 it to have the correct level. */
25620 }
25622 }
25624 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25625 'decltype(auto)' or a deduced class template. */
25627 bool
25629 {
25635 else
25637 }
25639 /* for_each_template_parm callback for type_uses_auto. */
25641 int
25643 {
25645 }
25647 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25648 a use of `auto'. Returns NULL_TREE otherwise. */
25650 tree
25652 {
25656 {
25657 /* The Concepts TS allows multiple autos in one type-specifier; just
25658 return the first one we find, do_auto_deduction will collect all of
25659 them. */
25663 else
25665 }
25666 else
25668 }
25670 /* For a given template T, return the vector of typedefs referenced
25671 in T for which access check is needed at T instantiation time.
25672 T is either a FUNCTION_DECL or a RECORD_TYPE.
25673 Those typedefs were added to T by the function
25674 append_type_to_template_for_access_check. */
25678 {
25679 tree ti;
25690 {
25695 }
25698 }
25700 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25701 tied to T. That list of typedefs will be access checked at
25702 T instantiation time.
25703 T is either a FUNCTION_DECL or a RECORD_TYPE.
25704 TYPE_DECL is a TYPE_DECL node representing a typedef.
25705 SCOPE is the scope through which TYPE_DECL is accessed.
25706 LOCATION is the location of the usage point of TYPE_DECL.
25708 This function is a subroutine of
25709 append_type_to_template_for_access_check. */
25711 static void
25713 tree type_decl,
25714 tree scope,
25715 location_t location)
25716 {
25717 qualified_typedef_usage_t typedef_usage;
25718 tree ti;
25725 && type_decl
25739 }
25741 /* Append TYPE_DECL to the template TEMPL.
25742 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25743 At TEMPL instanciation time, TYPE_DECL will be checked to see
25744 if it can be accessed through SCOPE.
25745 LOCATION is the location of the usage point of TYPE_DECL.
25747 e.g. consider the following code snippet:
25749 class C
25750 {
25751 typedef int myint;
25752 };
25754 template<class U> struct S
25755 {
25756 C::myint mi; // <-- usage point of the typedef C::myint
25757 };
25759 S<char> s;
25761 At S<char> instantiation time, we need to check the access of C::myint
25762 In other words, we need to check the access of the myint typedef through
25763 the C scope. For that purpose, this function will add the myint typedef
25764 and the scope C through which its being accessed to a list of typedefs
25765 tied to the template S. That list will be walked at template instantiation
25766 time and access check performed on each typedefs it contains.
25767 Note that this particular code snippet should yield an error because
25768 myint is private to C. */
25770 void
25772 tree type_decl,
25773 tree scope,
25774 location_t location)
25775 {
25781 /* Make sure we don't append the type to the template twice. */
25788 }
25790 /* Convert the generic type parameters in PARM that match the types given in the
25791 range [START_IDX, END_IDX) from the current_template_parms into generic type
25792 packs. */
25794 tree
25796 {
25807 {
25808 /* Create a distinct parameter pack type from the current parm and add it
25809 to the replacement args to tsubst below into the generic function
25810 parameter. */
25825 }
25831 /* If there are more levels then build up the replacement with the outer
25832 template parms. */
25836 replacement);
25839 }
25841 /* Entries in the decl_constraint hash table. */
25843 {
25844 tree decl;
25845 tree ci;
25846 };
25848 /* Hashing function and equality for constraint entries. */
25850 {
25852 {
25854 }
25857 {
25859 }
25860 };
25862 /* A mapping from declarations to constraint information. Note that
25863 both templates and their underlying declarations are mapped to the
25864 same constraint information.
25866 FIXME: This is defined in pt.c because garbage collection
25867 code is not being generated for constraint.cc. */
25871 /* Returns the template constraints of declaration T. If T is not
25872 constrained, return NULL_TREE. Note that T must be non-null. */
25874 tree
25876 {
25887 else
25889 }
25891 /* Associate the given constraint information CI with the declaration
25892 T. If T is a template, then the constraints are associated with
25893 its underlying declaration. Don't build associations if CI is
25894 NULL_TREE. */
25896 void
25898 {
25910 }
25912 /* Remove the associated constraints of the declaration T. */
25914 void
25916 {
25925 }
25927 /* Memoized satisfaction results for declarations. This
25928 maps the pair (constraint_info, arguments) to the result computed
25929 by constraints_satisfied_p. */
25932 {
25933 tree ci;
25934 tree args;
25935 tree result;
25936 };
25938 /* Hashing function and equality for constraint entries. */
25941 {
25943 {
25946 }
25949 {
25951 }
25952 };
25954 /* Memoized satisfaction results for concept checks. */
25957 {
25958 tree tmpl;
25959 tree args;
25960 tree result;
25961 };
25963 /* Hashing function and equality for constraint entries. */
25966 {
25968 {
25970 }
25973 {
25978 }
25979 };
25984 /* Search for a memoized satisfaction result. Returns one of the
25985 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25987 tree
25989 {
25994 else
25996 }
25998 /* Memoize the result of a satisfication test. Returns the saved result. */
26000 tree
26002 {
26009 }
26011 /* Search for a memoized satisfaction result for a concept. */
26013 tree
26015 {
26020 else
26022 }
26024 /* Memoize the result of a concept check. Returns the saved result. */
26026 tree
26028 {
26035 }
26039 /* Returns a prior concept specialization. This returns the substituted
26040 and normalized constraints defined by the concept. */
26042 tree
26044 {
26049 else
26051 }
26053 /* Save a concept expansion for later. */
26055 tree
26057 {
26064 }
26066 static hashval_t
26068 {
26077 }
26079 /* Compare the constraints of two subsumption entries. The LEFT1 and
26080 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26081 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26083 static bool
26085 {
26093 }
26095 /* Key/value pair for learning and memoizing subsumption results. This
26096 associates a pair of check constraints (including arguments) with
26097 a boolean value indicating the result. */
26100 {
26101 tree t1;
26102 tree t2;
26104 };
26106 /* Hashing function and equality for constraint entries. */
26109 {
26111 {
26113 }
26116 {
26121 }
26122 };
26126 /* Search for a previously cached subsumption result. */
26130 {
26135 else
26137 }
26139 /* Save a subsumption result. */
26141 bool
26143 {
26150 }
26152 /* Set up the hash table for constraint association. */
26154 void
26156 {
26165 }
26167 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26168 0..N-1. */
26170 void
26172 {
26175 integer_type_node,
26176 NULL_TREE),
26180 }
26182 /* Set up the hash tables for template instantiations. */
26184 void
26186 {
26192 }
26194 /* Print stats about the template hash tables for -fstats. */
26196 void
26198 {
26207 }