| blob | 416f1323f4fa5ff3e89549cc27322c00a9875ce3 |
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);
219 /* Make the current scope suitable for access checking when we are
220 processing T. T can be FUNCTION_DECL for instantiated function
221 template, VAR_DECL for static member variable, or TYPE_DECL for
222 alias template (needed by instantiate_decl). */
224 static void
226 {
234 else
238 {
239 saved_access_scope = tree_cons
242 }
243 }
245 /* Restore the scope set up by push_access_scope. T is the node we
246 are processing. */
248 static void
250 {
252 {
255 }
259 else
261 }
263 /* Do any processing required when DECL (a member template
264 declaration) is finished. Returns the TEMPLATE_DECL corresponding
265 to DECL, unless it is a specialization, in which case the DECL
266 itself is returned. */
268 tree
270 {
277 {
278 tree type;
286 {
290 }
292 }
296 {
298 {
301 }
302 else
304 }
305 else
309 }
311 /* Create a template info node. */
313 tree
315 {
320 }
322 /* Return the template info node corresponding to T, whatever T is. */
324 tree
326 {
348 }
350 /* Returns the template nesting level of the indicated class TYPE.
352 For example, in:
353 template <class T>
354 struct A
355 {
356 template <class U>
357 struct B {};
358 };
360 A<T>::B<U> has depth two, while A<T> has depth one.
361 Both A<T>::B<int> and A<int>::B<U> have depth one, if
362 they are instantiations, not specializations.
364 This function is guaranteed to return 0 if passed NULL_TREE so
365 that, for example, `template_class_depth (current_class_type)' is
366 always safe. */
368 int
370 {
374 {
385 else
387 }
390 }
392 /* Subroutine of maybe_begin_member_template_processing.
393 Returns true if processing DECL needs us to push template parms. */
395 static bool
397 {
403 }
405 /* Subroutine of maybe_begin_member_template_processing.
406 Push the template parms in PARMS, starting from LEVELS steps into the
407 chain, and ending at the beginning, since template parms are listed
408 innermost first. */
410 static void
412 {
420 current_template_parms
426 NULL);
428 {
437 {
444 /* Push the CONST_DECL. */
450 }
451 }
452 }
454 /* Restore the template parameter context for a member template, a
455 friend template defined in a class definition, or a non-template
456 member of template class. */
458 void
460 {
461 tree parms;
466 {
469 /* Disregard full specializations (c++/60999). */
472 }
475 {
480 {
483 }
486 }
488 /* Remember how many levels of template parameters we pushed so that
489 we can pop them later. */
491 }
493 /* Undo the effects of maybe_begin_member_template_processing. */
495 void
497 {
506 {
510 }
511 }
513 /* Return a new template argument vector which contains all of ARGS,
514 but has as its innermost set of arguments the EXTRA_ARGS. */
516 static tree
518 {
519 tree new_args;
537 }
539 /* Like add_to_template_args, but only the outermost ARGS are added to
540 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
541 (EXTRA_ARGS) levels are added. This function is used to combine
542 the template arguments from a partial instantiation with the
543 template arguments used to attain the full instantiation from the
544 partial instantiation. */
546 static tree
548 {
549 tree new_args;
551 /* If there are more levels of EXTRA_ARGS than there are ARGS,
552 something very fishy is going on. */
555 /* If *all* the new arguments will be the EXTRA_ARGS, just return
556 them. */
560 /* For the moment, we make ARGS look like it contains fewer levels. */
565 /* Now, we restore ARGS to its full dimensions. */
569 }
571 /* Return the N levels of innermost template arguments from the ARGS. */
573 tree
575 {
576 tree new_args;
582 /* If N is 1, just return the innermost set of template arguments. */
586 /* If we're not removing anything, just return the arguments we were
587 given. */
593 /* Make a new set of arguments, not containing the outer arguments. */
600 }
602 /* The inverse of get_innermost_template_args: Return all but the innermost
603 EXTRA_LEVELS levels of template arguments from the ARGS. */
605 static tree
607 {
608 tree new_args;
614 /* If N is 1, just return the outermost set of template arguments. */
618 /* If we're not removing anything, just return the arguments we were
619 given. */
624 /* Make a new set of arguments, not containing the inner arguments. */
631 }
633 /* We've got a template header coming up; push to a new level for storing
634 the parms. */
636 void
638 {
639 /* We use a non-tag-transparent scope here, which causes pushtag to
640 put tags in this scope, rather than in the enclosing class or
641 namespace scope. This is the right thing, since we want
642 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
643 global template class, push_template_decl handles putting the
644 TEMPLATE_DECL into top-level scope. For a nested template class,
645 e.g.:
647 template <class T> struct S1 {
648 template <class T> struct S2 {};
649 };
651 pushtag contains special code to call pushdecl_with_scope on the
652 TEMPLATE_DECL for S2. */
658 /* Add a dummy parameter level while we process the parameter list. */
659 current_template_parms
662 current_template_parms);
663 }
665 /* This routine is called when a specialization is declared. If it is
666 invalid to declare a specialization here, an error is reported and
667 false is returned, otherwise this routine will return true. */
669 static bool
671 {
674 /* [temp.expl.spec]
676 An explicit specialization shall be declared in the namespace of
677 which the template is a member, or, for member templates, in the
678 namespace of which the enclosing class or enclosing class
679 template is a member. An explicit specialization of a member
680 function, member class or static data member of a class template
681 shall be declared in the namespace of which the class template
682 is a member. */
684 {
687 }
689 /* [temp.expl.spec]
691 In an explicit specialization declaration for a member of a class
692 template or a member template that appears in namespace scope,
693 the member template and some of its enclosing class templates may
694 remain unspecialized, except that the declaration shall not
695 explicitly specialize a class member template if its enclosing
696 class templates are not explicitly specialized as well. */
698 {
701 }
704 }
706 /* We've just seen template <>. */
708 bool
710 {
714 }
716 /* Called at then end of processing a declaration preceded by
717 template<>. */
719 void
721 {
724 }
726 /* Any template <>'s that we have seen thus far are not referring to a
727 function specialization. */
729 void
731 {
734 }
736 /* We've just seen a template header. If SPECIALIZATION is nonzero,
737 it was of the form template <>. */
739 static void
741 {
743 template_header_count++;
744 }
746 /* We're beginning an explicit instantiation. */
748 void
750 {
753 }
756 void
758 {
761 }
763 /* An explicit specialization or partial specialization of TMPL is being
764 declared. Check that the namespace in which the specialization is
765 occurring is permissible. Returns false iff it is invalid to
766 specialize TMPL in the current namespace. */
768 static bool
770 {
773 /* [tmpl.expl.spec]
775 An explicit specialization shall be declared in a namespace enclosing the
776 specialized template. An explicit specialization whose declarator-id is
777 not qualified shall be declared in the nearest enclosing namespace of the
778 template, or, if the namespace is inline (7.3.1), any namespace from its
779 enclosing namespace set. */
782 {
785 }
790 /* Same or enclosing namespace. */
792 else
793 {
799 }
800 }
802 /* SPEC is an explicit instantiation. Check that it is valid to
803 perform this explicit instantiation in the current namespace. */
805 static void
807 {
808 tree ns;
810 /* DR 275: An explicit instantiation shall appear in an enclosing
811 namespace of its template. */
817 }
819 // Returns the type of a template specialization only if that
820 // specialization needs to be defined. Otherwise (e.g., if the type has
821 // already been defined), the function returns NULL_TREE.
822 static tree
824 {
825 // An implicit instantiation of an incomplete type implies
826 // the definition of a new class template.
827 //
828 // template<typename T>
829 // struct S;
830 //
831 // template<typename T>
832 // struct S<T*>;
833 //
834 // Here, S<T*> is an implicit instantiation of S whose type
835 // is incomplete.
839 // It can also be the case that TYPE is a completed specialization.
840 // Continuing the previous example, suppose we also declare:
841 //
842 // template<typename T>
843 // requires Integral<T>
844 // struct S<T*>;
845 //
846 // Here, S<T*> refers to the specialization S<T*> defined
847 // above. However, we need to differentiate definitions because
848 // we intend to define a new partial specialization. In this case,
849 // we rely on the fact that the constraints are different for
850 // this declaration than that above.
851 //
852 // Note that we also get here for injected class names and
853 // late-parsed template definitions. We must ensure that we
854 // do not create new type declarations for those cases.
856 {
860 // If there are no template parameters, this cannot be a new
861 // partial template specializtion?
865 // The injected-class-name is not a new partial specialization.
869 // If the constraints are not the same as those of the primary
870 // then, we can probably create a new specialization.
874 {
878 }
880 // Also, if there's a pre-existing specialization with matching
881 // constraints, then this also isn't new.
884 {
892 }
894 // Create a new type node (and corresponding type decl)
895 // for the newly declared specialization.
900 /* We only need a separate type node for storing the definition of this
901 partial specialization; uses of S<T*> are unconstrained, so all are
902 equivalent. So keep TYPE_CANONICAL the same. */
905 // Build the corresponding type decl.
911 }
914 }
916 /* The TYPE is being declared. If it is a template type, that means it
917 is a partial specialization. Do appropriate error-checking. */
919 tree
921 {
922 tree context;
927 /* A lambda that appears in specialization context is not itself a
928 specialization. */
933 {
937 }
942 {
948 else
951 }
953 {
954 /* This is for ordinary explicit specialization and partial
955 specialization of a template class such as:
957 template <> class C<int>;
959 or:
961 template <class T> class C<T*>;
963 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
966 {
973 {
978 }
979 }
985 /* Trying to define a specialization either without a template<> header
986 or in an inappropriate place. We've already given an error, so just
987 bail now so we don't actually define the specialization. */
989 }
995 {
996 /* This is for an explicit specialization of member class
997 template according to [temp.expl.spec/18]:
999 template <> template <class U> class C<int>::D;
1001 The context `C<int>' must be an implicit instantiation.
1002 Otherwise this is just a member class template declared
1003 earlier like:
1005 template <> class C<int> { template <class U> class D; };
1006 template <> template <class U> class C<int>::D;
1008 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1009 while in the second case, `C<int>::D' is a primary template
1010 and `C<T>::D' may not exist. */
1014 {
1015 tree t;
1020 {
1025 }
1027 /* Check for invalid specialization after instantiation:
1029 template <> template <> class C<int>::D<int>;
1030 template <> template <class U> class C<int>::D; */
1034 {
1038 {
1039 /* We already have a full specialization of this partial
1040 instantiation, or a full specialization has been
1041 looked up but not instantiated. Reassign it to the
1042 new member specialization template. */
1043 spec_entry elt;
1055 spec_entry **slot
1060 }
1061 else
1062 /* But if we've had an implicit instantiation, that's a
1063 problem ([temp.expl.spec]/6). */
1066 }
1068 /* Mark TYPE as a specialization. And as a result, we only
1069 have one level of template argument for the innermost
1070 class template. */
1075 }
1076 }
1078 {
1079 /* Someday C++0x may allow for enum template specialization. */
1084 else
1085 {
1088 }
1089 }
1092 }
1094 /* Returns nonzero if we can optimize the retrieval of specializations
1095 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1096 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1100 {
1103 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1104 parameter. */
1106 /* The optimized lookup depends on the fact that the
1107 template arguments for the member function template apply
1108 purely to the containing class, which is not true if the
1109 containing class is an explicit or partial
1110 specialization. */
1114 /* It is possible to have a template that is not a member
1115 template and is not a member of a template class:
1117 template <typename T>
1118 struct S { friend A::f(); };
1120 Here, the friend function is a template, but the context does
1121 not have template information. The optimized lookup relies
1122 on having ARGS be the template arguments for both the class
1123 and the function template. */
1125 }
1127 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1128 gone through coerce_template_parms by now. */
1130 static void
1132 {
1135 {
1138 {
1145 /* Allow typedefs on the type of a non-type argument, since a
1147 else
1149 }
1150 }
1152 }
1154 /* Retrieve the specialization (in the sense of [temp.spec] - a
1155 specialization is either an instantiation or an explicit
1156 specialization) of TMPL for the given template ARGS. If there is
1157 no such specialization, return NULL_TREE. The ARGS are a vector of
1158 arguments, or a vector of vectors of arguments, in the case of
1159 templates with more than one level of parameters.
1161 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1162 then we search for a partial specialization matching ARGS. This
1163 parameter is ignored if TMPL is not a class template.
1165 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1166 result is a NONTYPE_ARGUMENT_PACK. */
1168 static tree
1170 {
1180 /* There should be as many levels of arguments as there are
1181 levels of parameters. */
1191 {
1192 tree class_template;
1193 tree class_specialization;
1195 tree fns;
1198 /* The template arguments actually apply to the containing
1199 class. Find the class specialization with those
1200 arguments. */
1202 class_specialization
1206 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1207 for the specialization. */
1211 /* Iterate through the methods with the indicated name, looking
1212 for the one that has an instance of TMPL. */
1215 {
1218 /* using-declarations can add base methods to the method vec,
1219 and we don't want those here. */
1222 }
1224 }
1225 else
1226 {
1228 spec_entry elt;
1237 else
1245 }
1248 }
1250 /* Like retrieve_specialization, but for local declarations. */
1252 tree
1254 {
1260 }
1262 /* Returns nonzero iff DECL is a specialization of TMPL. */
1264 int
1266 {
1267 tree t;
1270 {
1276 }
1277 else
1278 {
1287 }
1290 }
1292 /* Returns nonzero iff DECL is a specialization of friend declaration
1293 FRIEND_DECL according to [temp.friend]. */
1295 bool
1297 {
1304 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1305 of a template class, we want to check if DECL is a specialization
1306 if this. */
1310 {
1311 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1314 }
1319 /* There is nothing to do if this is not a template friend. */
1326 /* [temp.friend/6]
1327 A member of a class template may be declared to be a friend of a
1328 non-template class. In this case, the corresponding member of
1329 every specialization of the class template is a friend of the
1330 class granting friendship.
1332 For example, given a template friend declaration
1334 template <class T> friend void A<T>::f();
1336 the member function below is considered a friend
1338 template <> struct A<int> {
1339 void f();
1340 };
1342 For this type of template friend, TEMPLATE_DEPTH below will be
1343 nonzero. To determine if DECL is a friend of FRIEND, we first
1344 check if the enclosing class is a specialization of another. */
1351 {
1352 /* Next, we check the members themselves. In order to handle
1353 a few tricky cases, such as when FRIEND_DECL's are
1355 template <class T> friend void A<T>::g(T t);
1356 template <class T> template <T t> friend void A<T>::h();
1358 and DECL's are
1360 void A<int>::g(int);
1361 template <int> void A<int>::h();
1363 we need to figure out ARGS, the template arguments from
1364 the context of DECL. This is required for template substitution
1365 of `T' in the function parameter of `g' and template parameter
1366 of `h' in the above examples. Here ARGS corresponds to `int'. */
1373 {
1375 {
1378 else
1380 current_depth++;
1381 }
1383 }
1386 {
1388 tree friend_type;
1389 tree decl_type;
1390 tree friend_args_type;
1391 tree decl_args_type;
1393 /* Make sure that both DECL and FRIEND_DECL are templates or
1394 non-templates. */
1400 {
1401 /* If both are templates, check template parameter list. */
1402 tree friend_parms
1407 friend_parms))
1411 }
1412 else
1420 /* Check if return types match. */
1424 /* Check if function parameter types match, ignoring the
1425 `this' parameter. */
1434 }
1435 else
1436 {
1437 /* DECL is a TYPE_DECL */
1441 /* Make sure that both DECL and FRIEND_DECL are templates or
1442 non-templates. */
1443 is_template
1450 {
1451 tree friend_parms;
1452 /* If both are templates, check the name of the two
1453 TEMPLATE_DECL's first because is_friend didn't. */
1458 /* Now check template parameter list. */
1459 friend_parms
1462 return comp_template_parms
1464 friend_parms);
1465 }
1466 else
1469 }
1470 }
1472 }
1474 /* Register the specialization SPEC as a specialization of TMPL with
1475 the indicated ARGS. IS_FRIEND indicates whether the specialization
1476 is actually just a friend declaration. Returns SPEC, or an
1477 equivalent prior declaration, if available.
1479 We also store instantiations of field packs in the hash table, even
1480 though they are not themselves templates, to make lookup easier. */
1482 static tree
1484 hashval_t hash)
1485 {
1486 tree fn;
1488 spec_entry elt;
1496 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1497 register it; we want the corresponding TEMPLATE_DECL instead.
1498 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1499 the more obvious `uses_template_parms (spec)' to avoid problems
1500 with default function arguments. In particular, given
1501 something like this:
1503 template <class T> void f(T t1, T t = T())
1505 the default argument expression is not substituted for in an
1506 instantiation unless and until it is actually needed. */
1510 /* We don't put these specializations in the hash table, but we might
1511 want to give an error about a mismatch. */
1513 else
1514 {
1522 slot =
1526 else
1528 }
1530 /* We can sometimes try to re-register a specialization that we've
1531 already got. In particular, regenerate_decl_from_template calls
1532 duplicate_decls which will update the specialization list. But,
1533 we'll still get called again here anyhow. It's more convenient
1534 to simply allow this than to try to prevent it. */
1538 {
1540 {
1543 {
1545 fn);
1547 }
1548 else
1549 {
1550 tree clone;
1551 /* This situation should occur only if the first
1552 specialization is an implicit instantiation, the
1553 second is an explicit specialization, and the
1554 implicit instantiation has not yet been used. That
1555 situation can occur if we have implicitly
1556 instantiated a member function and then specialized
1557 it later.
1559 We can also wind up here if a friend declaration that
1560 looked like an instantiation turns out to be a
1561 specialization:
1563 template <class T> void foo(T);
1564 class S { friend void foo<>(int) };
1565 template <> void foo(int);
1567 We transform the existing DECL in place so that any
1568 pointers to it become pointers to the updated
1569 declaration.
1571 If there was a definition for the template, but not
1572 for the specialization, we want this to look as if
1573 there were no definition, and vice versa. */
1576 /* The call to duplicate_decls will have applied
1577 [temp.expl.spec]:
1579 An explicit specialization of a function template
1580 is inline only if it is explicitly declared to be,
1581 and independently of whether its function template
1582 is.
1584 to the primary function; now copy the inline bits to
1585 the various clones. */
1587 {
1594 }
1598 }
1599 }
1601 {
1604 /* We've already complained in duplicate_decls. */
1608 /* Dup decl failed, but this is a new definition. Set the
1609 line number so any errors match this new
1610 definition. */
1614 }
1615 }
1619 /* A specialization must be declared in the same namespace as the
1620 template it is specializing. */
1626 {
1635 /* If TMPL is a forward declaration of a template function, keep a list
1636 of all specializations in case we need to reassign them to a friend
1637 template later in tsubst_friend_function.
1639 Also keep a list of all variable template instantiations so that
1640 process_partial_specialization can check whether a later partial
1641 specialization would have used it. */
1644 }
1647 }
1649 /* Returns true iff two spec_entry nodes are equivalent. */
1653 bool
1655 {
1662 /* tmpl could be a FIELD_DECL for a capture pack. */
1666 {
1667 /* Partial specializations of a variable template can be distinguished by
1668 constraints. */
1672 }
1676 }
1678 /* Returns a hash for a template TMPL and template arguments ARGS. */
1680 static hashval_t
1682 {
1685 }
1687 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1688 ignoring SPEC. */
1690 hashval_t
1692 {
1694 }
1696 /* Recursively calculate a hash value for a template argument ARG, for use
1697 in the hash tables of template specializations. */
1699 hashval_t
1701 {
1721 {
1729 {
1734 }
1756 {
1760 {
1763 }
1765 }
1769 {
1772 }
1783 val = iterative_hash_template_arg
1795 val);
1797 val);
1806 /* A lambda can't appear in a template arg, but don't crash on
1807 erroneous input. */
1819 /* Now hash operands as usual. */
1824 }
1827 {
1830 {
1831 // We want an alias specialization that survived strip_typedefs
1832 // to hash differently from its TYPE_CANONICAL, to avoid hash
1833 // collisions that compare as different in template_args_equal.
1834 // These could be dependent specializations that strip_typedefs
1835 // left alone, or untouched specializations because
1836 // coerce_template_parms returns the unconverted template
1837 // arguments if it sees incomplete argument packs.
1840 }
1843 val);
1846 /* Otherwise just compare the types during lookup. */
1855 {
1860 }
1861 }
1864 }
1866 /* Unregister the specialization SPEC as a specialization of TMPL.
1867 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1868 if the SPEC was listed as a specialization of TMPL.
1870 Note that SPEC has been ggc_freed, so we can't look inside it. */
1872 bool
1874 {
1876 spec_entry elt;
1884 {
1889 }
1892 }
1894 /* Like register_specialization, but for local declarations. We are
1895 registering SPEC, an instantiation of TMPL. */
1897 void
1899 {
1901 }
1903 /* TYPE is a class type. Returns true if TYPE is an explicitly
1904 specialized class. */
1906 bool
1908 {
1912 }
1914 /* Print the list of functions at FNS, going through all the overloads
1915 for each element of the list. Alternatively, FNS can not be a
1916 TREE_LIST, in which case it will be printed together with all the
1917 overloads.
1919 MORE and *STR should respectively be FALSE and NULL when the function
1920 is called from the outside. They are used internally on recursive
1921 calls. print_candidates manages the two parameters and leaves NULL
1922 in *STR when it ends. */
1924 static void
1926 {
1932 {
1936 }
1937 else
1938 {
1941 {
1942 /* Pick the prefix string. */
1944 {
1948 }
1952 }
1955 }
1958 {
1961 }
1962 }
1964 /* Print the list of candidate FNS in an error message. FNS can also
1965 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1967 void
1969 {
1973 }
1975 /* Get a (possibly) constrained template declaration for the
1976 purpose of ordering candidates. */
1977 static tree
1979 {
1985 }
1987 /* Among candidates having the same signature, return the
1988 most constrained or NULL_TREE if there is no best candidate.
1989 If the signatures of candidates vary (e.g., template
1990 specialization vs. member function), then there can be no
1991 most constrained.
1993 Note that we don't compare constraints on the functions
1994 themselves, but rather those of their templates. */
1995 static tree
1997 {
1998 // Try to find the best candidate in a first pass.
2001 {
2008 }
2010 // Verify that the champ is better than previous candidates.
2015 }
2018 }
2021 /* Returns the template (one of the functions given by TEMPLATE_ID)
2022 which can be specialized to match the indicated DECL with the
2023 explicit template args given in TEMPLATE_ID. The DECL may be
2024 NULL_TREE if none is available. In that case, the functions in
2025 TEMPLATE_ID are non-members.
2027 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2028 specialization of a member template.
2030 The TEMPLATE_COUNT is the number of references to qualifying
2031 template classes that appeared in the name of the function. See
2032 check_explicit_specialization for a more accurate description.
2034 TSK indicates what kind of template declaration (if any) is being
2035 declared. TSK_TEMPLATE indicates that the declaration given by
2036 DECL, though a FUNCTION_DECL, has template parameters, and is
2037 therefore a template function.
2039 The template args (those explicitly specified and those deduced)
2040 are output in a newly created vector *TARGS_OUT.
2042 If it is impossible to determine the result, an error message is
2043 issued. The error_mark_node is returned to indicate failure. */
2045 static tree
2047 tree decl,
2051 tmpl_spec_kind tsk)
2052 {
2053 tree fns;
2054 tree targs;
2055 tree explicit_targs;
2058 /* A TREE_LIST of templates of which DECL may be a specialization.
2059 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2060 corresponding TREE_PURPOSE is the set of template arguments that,
2061 when used to instantiate the template, would produce a function
2062 with the signature of DECL. */
2072 /* We shouldn't be specializing a member template of an
2073 unspecialized class template; we already gave an error in
2074 check_specialization_scope, now avoid crashing. */
2077 {
2080 }
2088 /* Check for baselinks. */
2093 {
2096 }
2098 {
2101 }
2103 /* Count the number of template headers specified for this
2104 specialization. */
2114 {
2117 tf_warning_or_error,
2121 }
2123 {
2127 {
2128 tree decl_arg_types;
2129 tree fn_arg_types;
2130 tree insttype;
2132 /* In case of explicit specialization, we need to check if
2133 the number of template headers appearing in the specialization
2134 is correct. This is usually done in check_explicit_specialization,
2135 but the check done there cannot be exhaustive when specializing
2136 member functions. Consider the following code:
2138 template <> void A<int>::f(int);
2139 template <> template <> void A<int>::f(int);
2141 Assuming that A<int> is not itself an explicit specialization
2142 already, the first line specializes "f" which is a non-template
2143 member function, whilst the second line specializes "f" which
2144 is a template member function. So both lines are syntactically
2145 correct, and check_explicit_specialization does not reject
2146 them.
2148 Here, we can do better, as we are matching the specialization
2149 against the declarations. We count the number of template
2150 headers, and we check if they match TEMPLATE_COUNT + 1
2151 (TEMPLATE_COUNT is the number of qualifying template classes,
2152 plus there must be another header for the member template
2153 itself).
2155 Notice that if header_count is zero, this is not a
2156 specialization but rather a template instantiation, so there
2157 is no check we can perform here. */
2161 /* Check that the number of template arguments at the
2162 innermost level for DECL is the same as for FN. */
2170 /* DECL might be a specialization of FN. */
2174 /* For a non-static member function, we need to make sure
2175 that the const qualification is the same. Since
2176 get_bindings does not try to merge the "this" parameter,
2177 we must do the comparison explicitly. */
2183 /* Skip the "this" parameter and, for constructors of
2184 classes with virtual bases, the VTT parameter. A
2185 full specialization of a constructor will have a VTT
2186 parameter, but a template never will. */
2187 decl_arg_types
2189 fn_arg_types
2192 /* Function templates cannot be specializations; there are
2193 no partial specializations of functions. Therefore, if
2194 the type of DECL does not match FN, there is no
2195 match.
2197 Note that it should never be the case that we have both
2198 candidates added here, and for regular member functions
2199 below. */
2201 {
2205 }
2207 /* See whether this function might be a specialization of this
2208 template. Suppress access control because we might be trying
2209 to make this specialization a friend, and we have already done
2210 access control for the declaration of the specialization. */
2216 /* We cannot deduce template arguments that when used to
2217 specialize TMPL will produce DECL. */
2220 /* Remove, from the set of candidates, all those functions
2221 whose constraints are not satisfied. */
2225 // Then, try to form the new function type.
2229 fn_arg_types
2234 /* Save this template, and the arguments deduced. */
2236 }
2238 /* FN is an ordinary member function, and we need a
2239 specialization of a member template. */
2240 ;
2242 /* We can get IDENTIFIER_NODEs here in certain erroneous
2243 cases. */
2244 ;
2246 /* This is just an ordinary non-member function. Nothing can
2247 be a specialization of that. */
2248 ;
2250 /* Cannot specialize functions that are created implicitly. */
2251 ;
2252 else
2253 {
2254 tree decl_arg_types;
2256 /* This is an ordinary member function. However, since
2257 we're here, we can assume its enclosing class is a
2258 template class. For example,
2260 template <typename T> struct S { void f(); };
2261 template <> void S<int>::f() {}
2263 Here, S<int>::f is a non-template, but S<int> is a
2264 template class. If FN has the same type as DECL, we
2265 might be in business. */
2268 /* Its enclosing class is an explicit specialization
2269 of a template class. This is not a candidate. */
2274 /* The return types differ. */
2277 /* Adjust the type of DECL in case FN is a static member. */
2284 decl_arg_types))
2287 // If the deduced arguments do not satisfy the constraints,
2288 // this is not a candidate.
2292 // Add the candidate.
2294 }
2295 }
2298 {
2299 /* We have:
2301 [temp.expl.spec]
2303 It is possible for a specialization with a given function
2304 signature to be instantiated from more than one function
2305 template. In such cases, explicit specification of the
2306 template arguments must be used to uniquely identify the
2307 function template specialization being specialized.
2309 Note that here, there's no suggestion that we're supposed to
2310 determine which of the candidate templates is most
2311 specialized. However, we, also have:
2313 [temp.func.order]
2315 Partial ordering of overloaded function template
2316 declarations is used in the following contexts to select
2317 the function template to which a function template
2318 specialization refers:
2320 -- when an explicit specialization refers to a function
2321 template.
2323 So, we do use the partial ordering rules, at least for now.
2324 This extension can only serve to make invalid programs valid,
2325 so it's safe. And, there is strong anecdotal evidence that
2326 the committee intended the partial ordering rules to apply;
2327 the EDG front end has that behavior, and John Spicer claims
2328 that the committee simply forgot to delete the wording in
2329 [temp.expl.spec]. */
2332 {
2335 }
2336 }
2338 // Concepts allows multiple declarations of member functions
2339 // with the same signature. Like above, we need to rely on
2340 // on the partial ordering of those candidates to determine which
2341 // is the best.
2343 {
2345 {
2348 }
2349 }
2352 {
2359 else
2362 }
2366 {
2372 }
2374 /* We have one, and exactly one, match. */
2376 {
2380 // Propagate the candidate's constraints to the declaration.
2383 /* DECL is a re-declaration or partial instantiation of a template
2384 function. */
2387 /* It was a specialization of an ordinary member function in a
2388 template class. */
2390 }
2392 /* It was a specialization of a template. */
2395 {
2400 }
2401 else
2404 }
2406 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2407 but with the default argument values filled in from those in the
2408 TMPL_TYPES. */
2410 static tree
2412 tree tmpl_types)
2413 {
2414 tree new_spec_types;
2422 /* Substitute into the rest of the list. */
2423 new_spec_types =
2427 /* Add the default argument for this parameter. */
2430 new_spec_types);
2431 }
2433 /* DECL is an explicit specialization. Replicate default arguments
2434 from the template it specializes. (That way, code like:
2436 template <class T> void f(T = 3);
2437 template <> void f(double);
2438 void g () { f (); }
2440 works, as required.) An alternative approach would be to look up
2441 the correct default arguments at the call-site, but this approach
2442 is consistent with how implicit instantiations are handled. */
2444 static void
2446 {
2447 tree tmpl;
2448 tree spec_types;
2449 tree tmpl_types;
2450 tree new_spec_types;
2451 tree old_type;
2452 tree new_type;
2453 tree t;
2458 /* See if there's anything we need to do. */
2471 {
2472 /* Remove the this pointer, but remember the object's type for
2473 CV quals. */
2479 {
2480 /* DECL may contain more parameters than TMPL due to the extra
2481 in-charge parameter in constructors and destructors. */
2484 }
2486 {
2489 }
2490 }
2492 /* Compute the merged default arguments. */
2493 new_spec_types =
2496 /* Compute the new FUNCTION_TYPE. */
2498 {
2502 new_spec_types);
2505 /* Put the in-charge parameter back. */
2508 new_spec_types);
2512 new_spec_types);
2513 }
2514 else
2516 new_spec_types);
2526 }
2528 /* Return the number of template headers we expect to see for a definition
2529 or specialization of CTYPE or one of its non-template members. */
2531 int
2533 {
2537 {
2538 /* You're supposed to have one `template <...>' for every
2539 template class, but you don't need one for a full
2540 specialization. For example:
2542 template <class T> struct S{};
2543 template <> struct S<int> { void f(); };
2544 void S<int>::f () {}
2546 is correct; there shouldn't be a `template <>' for the
2547 definition of `S<int>::f'. */
2549 /* If CTYPE does not have template information of any
2550 kind, then it is not a template, nor is it nested
2551 within a template. */
2559 }
2562 }
2564 /* Do a simple sanity check on the template headers that precede the
2565 variable declaration DECL. */
2567 void
2569 {
2574 {
2577 "variable templates only available with "
2580 // Namespace-scope variable templates should have a template header.
2582 }
2584 {
2591 "members of an explicitly specialized class are defined "
2593 }
2594 }
2596 /* An explicit specialization whose declarator-id or class-head-name is not
2597 qualified shall be declared in the nearest enclosing namespace of the
2598 template, or, if the namespace is inline (7.3.1), any namespace from its
2599 enclosing namespace set.
2601 If the name declared in the explicit instantiation is an unqualified name,
2602 the explicit instantiation shall appear in the namespace where its template
2603 is declared or, if that namespace is inline (7.3.1), any namespace from its
2604 enclosing namespace set. */
2606 void
2608 {
2613 {
2619 /* This was allowed in C++98, so only pedwarn. */
2621 "outside its namespace must use a nested-name-"
2623 }
2624 }
2626 /* Check to see if the function just declared, as indicated in
2627 DECLARATOR, and in DECL, is a specialization of a function
2628 template. We may also discover that the declaration is an explicit
2629 instantiation at this point.
2631 Returns DECL, or an equivalent declaration that should be used
2632 instead if all goes well. Issues an error message if something is
2633 amiss. Returns error_mark_node if the error is not easily
2634 recoverable.
2636 FLAGS is a bitmask consisting of the following flags:
2638 2: The function has a definition.
2639 4: The function is a friend.
2641 The TEMPLATE_COUNT is the number of references to qualifying
2642 template classes that appeared in the name of the function. For
2643 example, in
2645 template <class T> struct S { void f(); };
2646 void S<int>::f();
2648 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2649 classes are not counted in the TEMPLATE_COUNT, so that in
2651 template <class T> struct S {};
2652 template <> struct S<int> { void f(); }
2653 template <> void S<int>::f();
2655 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2656 invalid; there should be no template <>.)
2658 If the function is a specialization, it is marked as such via
2659 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2660 is set up correctly, and it is added to the list of specializations
2661 for that template. */
2663 tree
2665 tree decl,
2668 {
2677 tmpl_spec_kind tsk;
2680 {
2683 else
2685 }
2686 else
2690 {
2693 {
2696 }
2698 {
2700 /* This could be something like:
2702 template <class T> void f(T);
2703 class S { friend void f<>(int); } */
2705 else
2706 {
2707 /* This case handles bogus declarations like template <>
2708 template <class T> void f<int>(); */
2711 declarator);
2713 }
2714 }
2718 /* The error has already been reported in
2719 check_specialization_scope. */
2725 /* Fall through. */
2738 decl);
2741 else
2745 /* Fall through. */
2751 /* In cases like template<> constexpr bool v = true;
2752 We'll give an error in check_template_variable. */
2758 else
2764 {
2765 /* This case handles bogus declarations like template <>
2766 template <class T> void f<int>(); */
2770 declarator);
2772 {
2773 /* Partial specialization of variable template. */
2777 }
2781 else
2785 ok:;
2786 }
2789 /* This is a specialization of a member template, without
2790 specialization the containing class. Something like:
2792 template <class T> struct S {
2793 template <class U> void f (U);
2794 };
2795 template <> template <class U> void S<int>::f(U) {}
2797 That's a specialization -- but of the entire template. */
2803 }
2806 /* This doesn't apply to variable templates. */
2809 {
2813 {
2817 }
2818 }
2821 {
2826 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2828 {
2829 tree fns;
2834 else
2835 {
2836 /* If there is no class context, the explicit instantiation
2837 must be at namespace scope. */
2840 /* Find the namespace binding, using the declaration
2841 context. */
2845 /* If lookup fails, look for a friend declaration so we can
2846 give a better diagnostic. */
2852 {
2855 }
2856 }
2859 }
2865 {
2867 /* A specialization in class scope. This is invalid,
2868 but the error will already have been flagged by
2869 check_specialization_scope. */
2871 else
2872 {
2873 /* It's not valid to write an explicit instantiation in
2874 class scope, e.g.:
2876 class C { template void f(); }
2878 This case is caught by the parser. However, on
2879 something like:
2881 template class C { void f(); };
2883 (which is invalid) we can get here. The error will be
2884 issued later. */
2885 ;
2886 }
2889 }
2892 {
2893 // We'll match variable templates in start_decl.
2897 /* Find the list of functions in ctype that have the same
2898 name as the declared function. */
2904 {
2909 {
2910 /* From [temp.expl.spec]:
2912 If such an explicit specialization for the member
2913 of a class template names an implicitly-declared
2914 special member function (clause _special_), the
2915 program is ill-formed.
2917 Similar language is found in [temp.explicit]. */
2920 }
2923 }
2926 {
2930 }
2931 else
2932 {
2934 tree ovl;
2936 /* For a type-conversion operator, we cannot do a
2937 name-based lookup. We might be looking for `operator
2938 int' which will be a specialization of `operator T'.
2939 So, we find *all* the conversion operators, and then
2940 select from them. */
2948 {
2950 /* There are no more conversion functions. */
2953 /* Glue all these conversion functions together
2954 with those we already have. */
2957 }
2958 }
2961 {
2964 }
2965 else
2967 }
2969 /* Figure out what exactly is being specialized at this point.
2970 Note that for an explicit instantiation, even one for a
2971 member function, we cannot tell apriori whether the
2972 instantiation is for a member template, or just a member
2973 function of a template class. Even if a member template is
2974 being instantiated, the member template arguments may be
2975 elided if they can be deduced from the rest of the
2976 declaration. */
2979 member_specialization,
2980 template_count,
2981 tsk);
2984 /* We couldn't figure out what this declaration was
2985 specializing. */
2987 else
2988 {
2991 {
2993 "friend declaration %qD is not visible to "
2997 }
3005 {
3006 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
3007 is done by do_decl_instantiation later. */
3013 {
3014 /* If TMPL is not the most general template (for
3015 example, if TMPL is a friend template that is
3016 injected into namespace scope), then there will
3017 be too many levels of TARGS. Remove some of them
3018 here. */
3020 tree new_targs;
3027 }
3030 }
3032 /* If we thought that the DECL was a member function, but it
3033 turns out to be specializing a static member function,
3034 make DECL a static member function as well. */
3040 /* If this is a specialization of a member template of a
3041 template class, we want to return the TEMPLATE_DECL, not
3042 the specialization of it. */
3044 {
3049 {
3050 tree parm;
3054 /* We want to use the argument list specified in the
3055 definition, not in the original declaration. */
3060 }
3063 }
3065 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3071 /* Inherit default function arguments from the template
3072 DECL is specializing. */
3076 /* This specialization has the same protection as the
3077 template it specializes. */
3081 /* 7.1.1-1 [dcl.stc]
3083 A storage-class-specifier shall not be specified in an
3084 explicit specialization...
3086 The parser rejects these, so unless action is taken here,
3087 explicit function specializations will always appear with
3088 global linkage.
3090 The action recommended by the C++ CWG in response to C++
3091 defect report 605 is to make the storage class and linkage
3092 of the explicit specialization match the templated function:
3094 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3095 */
3097 {
3101 /* A concept cannot be specialized. */
3103 {
3105 gen_tmpl);
3107 }
3109 /* This specialization has the same linkage and visibility as
3110 the function template it specializes. */
3113 {
3116 }
3119 {
3122 }
3123 }
3125 /* If DECL is a friend declaration, declared using an
3126 unqualified name, the namespace associated with DECL may
3127 have been set incorrectly. For example, in:
3129 template <typename T> void f(T);
3130 namespace N {
3131 struct S { friend void f<int>(int); }
3132 }
3134 we will have set the DECL_CONTEXT for the friend
3135 declaration to N, rather than to the global namespace. */
3140 /* This is not really a declaration of a specialization.
3141 It's just the name of an instantiation. But, it's not
3142 a request for an instantiation, either. */
3145 /* A specialization is not necessarily COMDAT. */
3151 /* If this is a full specialization, register it so that we can find
3152 it again. Partial specializations will be registered in
3153 process_partial_specialization. */
3158 /* A 'structor should already have clones. */
3164 }
3165 }
3168 }
3170 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3171 parameters. These are represented in the same format used for
3172 DECL_TEMPLATE_PARMS. */
3174 int
3176 {
3177 const_tree p1;
3178 const_tree p2;
3186 {
3198 {
3202 /* If either of the template parameters are invalid, assume
3203 they match for the sake of error recovery. */
3216 }
3217 }
3220 /* One set of parameters has more parameters lists than the
3221 other. */
3225 }
3227 /* Determine whether PARM is a parameter pack. */
3229 bool
3231 {
3232 /* Determine if we have a non-type template parameter pack. */
3239 /* If this is a list of template parameters, we could get a
3240 TYPE_DECL or a TEMPLATE_DECL. */
3244 /* Otherwise it must be a type template parameter. */
3248 }
3250 /* Determine if T is a function parameter pack. */
3252 bool
3254 {
3258 }
3260 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3261 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3263 tree
3265 {
3272 }
3274 /* Return true iff the function parameter PARAM_DECL was expanded
3275 from the function parameter pack PACK. */
3277 bool
3279 {
3284 /* The parameter pack and its pack arguments have the same
3285 DECL_PARM_INDEX. */
3287 }
3289 /* Determine whether ARGS describes a variadic template args list,
3290 i.e., one that is terminated by a template argument pack. */
3292 static bool
3294 {
3296 tree last_parm;
3310 }
3312 /* Generate a new name for the parameter pack name NAME (an
3313 IDENTIFIER_NODE) that incorporates its */
3315 static tree
3317 {
3318 /* Munge the name to include the parameter index. */
3319 #define NUMBUF_LEN 128
3333 }
3335 /* Return true if T is a primary function, class or alias template
3336 instantiation. */
3338 bool
3340 {
3354 }
3356 /* Return true if PARM is a template template parameter. */
3358 bool
3360 {
3362 }
3364 /* Return true iff PARM is a DECL representing a type template
3365 parameter. */
3367 bool
3369 {
3374 }
3376 /* Return the template parameters of T if T is a
3377 primary template instantiation, NULL otherwise. */
3379 tree
3381 {
3386 parms = INNERMOST_TEMPLATE_PARMS
3390 }
3392 /* Return the template parameters of the LEVELth level from the full list
3393 of template parameters PARMS. */
3395 tree
3397 {
3398 tree p;
3409 }
3411 /* Returns the template arguments of T if T is a template instantiation,
3412 NULL otherwise. */
3414 tree
3416 {
3424 }
3426 /* Return the argument pack elements of T if T is a template argument pack,
3427 NULL otherwise. */
3429 tree
3431 {
3437 }
3439 /* Structure used to track the progress of find_parameter_packs_r. */
3440 struct find_parameter_pack_data
3441 {
3442 /* TREE_LIST that will contain all of the parameter packs found by
3443 the traversal. */
3446 /* Set of AST nodes that have been visited by the traversal. */
3449 /* True iff we're making a type pack expansion. */
3451 };
3453 /* Identifies all of the argument packs that occur in a template
3454 argument and appends them to the TREE_LIST inside DATA, which is a
3455 find_parameter_pack_data structure. This is a subroutine of
3456 make_pack_expansion and uses_parameter_packs. */
3457 static tree
3459 {
3465 /* Handle type aliases/typedefs. */
3467 {
3474 }
3476 /* Identify whether this is a parameter pack or not. */
3478 {
3486 /* FALLTHRU */
3488 /* If the placeholder appears in the decl-specifier-seq of a function
3489 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3490 is a pack expansion, the invented template parameter is a template
3491 parameter pack. */
3501 {
3502 /* We don't want to walk into the type of a PARM_DECL,
3503 because we don't want to see the type parameter pack. */
3506 }
3509 /* Look through a lambda capture proxy to the field pack. */
3512 {
3518 }
3520 {
3522 find_parameter_packs_r,
3525 }
3532 /* Not a parameter pack. */
3534 }
3537 {
3538 /* Add this parameter pack to the list. */
3540 }
3546 /* This switch statement will return immediately if we don't find a
3547 parameter pack. */
3549 {
3554 /* Check the template itself. */
3557 /* Check the template arguments. */
3573 /* Fall through. */
3618 {
3619 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3620 type_pack_expansion_p to false so that any placeholders
3621 within the expression don't get marked as parameter packs. */
3629 }
3633 }
3636 }
3638 /* Determines if the expression or type T uses any parameter packs. */
3639 bool
3641 {
3650 }
3652 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3653 representation a base-class initializer into a parameter pack
3654 expansion. If all goes well, the resulting node will be an
3655 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3656 respectively. */
3657 tree
3659 {
3660 tree result;
3669 {
3670 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3671 class initializer. In this case, the TREE_PURPOSE will be a
3672 _TYPE node (representing the base class expansion we're
3673 initializing) and the TREE_VALUE will be a TREE_LIST
3674 containing the initialization arguments.
3676 The resulting expansion looks somewhat different from most
3677 expansions. Rather than returning just one _EXPANSION, we
3678 return a TREE_LIST whose TREE_PURPOSE is a
3679 TYPE_PACK_EXPANSION containing the bases that will be
3680 initialized. The TREE_VALUE will be identical to the
3681 original TREE_VALUE, which is a list of arguments that will
3682 be passed to each base. We do not introduce any new pack
3683 expansion nodes into the TREE_VALUE (although it is possible
3684 that some already exist), because the TREE_PURPOSE and
3685 TREE_VALUE all need to be expanded together with the same
3686 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3687 resulting TREE_PURPOSE will mention the parameter packs in
3688 both the bases and the arguments to the bases. */
3689 tree purpose;
3690 tree value;
3693 /* Determine which parameter packs will be used by the base
3694 class expansion. */
3703 {
3707 }
3710 {
3711 /* Collect the sets of parameter packs used in each of the
3712 initialization arguments. */
3714 {
3715 /* Determine which parameter packs will be expanded in this
3716 argument. */
3719 }
3720 }
3724 /* Create the pack expansion type for the base type. */
3729 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3730 they will rarely be compared to anything. */
3734 }
3739 /* Build the PACK_EXPANSION_* node. */
3740 result = for_types
3745 {
3746 /* Propagate type and const-expression information. */
3749 /* Mark this read now, since the expansion might be length 0. */
3751 }
3752 else
3753 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3754 they will rarely be compared to anything. */
3757 /* Determine which parameter packs will be expanded. */
3764 /* Make sure we found some parameter packs. */
3766 {
3769 else
3772 }
3778 }
3780 /* Checks T for any "bare" parameter packs, which have not yet been
3781 expanded, and issues an error if any are found. This operation can
3782 only be done on full expressions or types (e.g., an expression
3783 statement, "if" condition, etc.), because we could have expressions like:
3785 foo(f(g(h(args)))...)
3787 where "args" is a parameter pack. check_for_bare_parameter_packs
3788 should not be called for the subexpressions args, h(args),
3789 g(h(args)), or f(g(h(args))), because we would produce erroneous
3790 error messages.
3792 Returns TRUE and emits an error if there were bare parameter packs,
3793 returns FALSE otherwise. */
3794 bool
3796 {
3813 {
3817 {
3826 else
3831 else
3835 }
3838 }
3841 }
3843 /* Expand any parameter packs that occur in the template arguments in
3844 ARGS. */
3845 tree
3847 {
3856 /* First, determine if we need to expand anything, and the number of
3857 slots we'll need. */
3859 {
3864 {
3868 else
3870 }
3871 else
3872 {
3874 num_result_args++;
3875 }
3876 }
3878 /* If no expansion is necessary, we're done. */
3882 /* Expand arguments. */
3885 non_default_args_count =
3888 {
3891 {
3898 }
3899 else
3900 {
3903 }
3904 }
3908 }
3910 /* Checks if DECL shadows a template parameter.
3912 [temp.local]: A template-parameter shall not be redeclared within its
3913 scope (including nested scopes).
3915 Emits an error and returns TRUE if the DECL shadows a parameter,
3916 returns FALSE otherwise. */
3918 bool
3920 {
3921 tree olddecl;
3923 /* If we're not in a template, we can't possibly shadow a template
3924 parameter. */
3928 /* Figure out what we're shadowing. */
3933 /* If there's no previous binding for this name, we're not shadowing
3934 anything, let alone a template parameter. */
3938 /* If we're not shadowing a template parameter, we're done. Note
3939 that OLDDECL might be an OVERLOAD (or perhaps even an
3940 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3941 node. */
3945 /* We check for decl != olddecl to avoid bogus errors for using a
3946 name inside a class. We check TPFI to avoid duplicate errors for
3947 inline member templates. */
3953 /* Don't complain about the injected class name, as we've already
3954 complained about the class itself. */
3961 else
3966 }
3968 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3969 ORIG_LEVEL, DECL, and TYPE. */
3971 static tree
3975 tree decl,
3976 tree type)
3977 {
3988 }
3990 /* Find the canonical type parameter for the given template type
3991 parameter. Returns the canonical type parameter, which may be TYPE
3992 if no such parameter existed. */
3994 static tree
3996 {
3997 tree list;
4011 else
4012 {
4017 }
4018 }
4020 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4021 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4022 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4023 new one is created. */
4025 static tree
4027 tsubst_flags_t complain)
4028 {
4033 {
4052 /* Template template parameters need this. */
4054 {
4061 }
4062 }
4065 }
4067 /* Process information from new template parameter PARM and append it
4068 to the LIST being built. This new parameter is a non-type
4069 parameter iff IS_NON_TYPE is true. This new parameter is a
4070 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4071 is in PARM_LOC. */
4073 tree
4076 {
4085 {
4089 {
4093 else
4095 }
4098 }
4101 {
4107 {
4108 /* [temp.param]
4110 The top-level cv-qualifiers on the template-parameter are
4111 ignored when determining its type. */
4116 && !is_parameter_pack
4117 /* If we're in a nested template parameter list, the template
4118 template parameter could be a parameter pack. */
4120 {
4121 /* This template parameter is not a parameter pack, but it
4122 should be. Complain about "bare" parameter packs. */
4125 /* Recover by calling this a parameter pack. */
4127 }
4128 }
4130 /* A template parameter is not modifiable. */
4139 processing_template_decl,
4144 }
4145 else
4146 {
4147 tree t;
4151 {
4153 /* This is for distinguishing between real templates and template
4154 template parameters */
4158 }
4159 else
4160 {
4162 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4165 }
4172 processing_template_decl,
4176 }
4180 /* Build requirements for the type/template parameter.
4181 This must be done after SET_DECL_TEMPLATE_PARM_P or
4182 process_template_parm could fail. */
4187 /* Build the parameter node linking the parameter declaration,
4188 its default argument (if any), and its constraints (if any). */
4193 }
4195 /* The end of a template parameter list has been reached. Process the
4196 tree list into a parameter vector, converting each parameter into a more
4197 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4198 as PARM_DECLs. */
4200 tree
4202 {
4207 /* Pop the dummy parameter level and add the real one. */
4210 current_template_parms
4215 {
4219 }
4224 }
4226 // Explicitly indicate the end of the template parameter list. We assume
4227 // that the current template parameters have been constructed and/or
4228 // managed explicitly, as when creating new template template parameters
4229 // from a shorthand constraint.
4230 void
4232 {
4234 }
4236 /* end_template_decl is called after a template declaration is seen. */
4238 void
4240 {
4246 /* This matches the pushlevel in begin_template_parm_list. */
4251 }
4253 /* Takes a TREE_LIST representing a template parameter and convert it
4254 into an argument suitable to be passed to the type substitution
4255 functions. Note that If the TREE_LIST contains an error_mark
4256 node, the returned argument is error_mark_node. */
4258 tree
4260 {
4273 {
4277 {
4278 /* Turn this argument into a TYPE_ARGUMENT_PACK
4279 with a single element, which expands T. */
4288 }
4289 }
4290 else
4291 {
4295 {
4296 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4297 with a single element, which expands T. */
4309 }
4310 else
4312 }
4314 }
4316 /* Given a single level of template parameters (a TREE_VEC), return it
4317 as a set of template arguments. */
4319 static tree
4321 {
4331 }
4333 /* Given a set of template parameters, return them as a set of template
4334 arguments. The template parameters are represented as a TREE_VEC, in
4335 the form documented in cp-tree.h for template arguments. */
4337 static tree
4339 {
4340 tree header;
4345 /* If there is only one level of template parameters, we do not
4346 create a TREE_VEC of TREE_VECs. Instead, we return a single
4347 TREE_VEC containing the arguments. */
4352 {
4357 else
4359 }
4362 }
4364 /* Within the declaration of a template, return the currently active
4365 template parameters as an argument TREE_VEC. */
4367 static tree
4369 {
4371 }
4373 /* Update the declared TYPE by doing any lookups which were thought to be
4374 dependent, but are not now that we know the SCOPE of the declarator. */
4376 tree
4378 {
4389 /* Don't bother building up the args in this case. */
4391 {
4392 /* tsubst in the args corresponding to the template parameters,
4393 including auto if present. Most things will be unchanged, but
4394 make_typename_type and tsubst_qualified_id will resolve
4395 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4398 tree pushed;
4400 {
4404 }
4409 }
4415 {
4418 else
4420 }
4422 }
4424 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4425 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4426 the new template is a member template. */
4428 tree
4430 {
4438 }
4440 struct template_parm_data
4441 {
4442 /* The level of the template parameters we are currently
4443 processing. */
4446 /* The index of the specialization argument we are currently
4447 processing. */
4450 /* An array whose size is the number of template parameters. The
4451 elements are nonzero if the parameter has been used in any one
4452 of the arguments processed so far. */
4455 /* An array whose size is the number of template arguments. The
4456 elements are nonzero if the argument makes use of template
4457 parameters of this level. */
4459 };
4461 /* Subroutine of push_template_decl used to see if each template
4462 parameter in a partial specialization is used in the explicit
4463 argument list. If T is of the LEVEL given in DATA (which is
4464 treated as a template_parm_data*), then DATA->PARMS is marked
4465 appropriately. */
4467 static int
4469 {
4477 {
4480 }
4482 /* In C++17 the type of a non-type argument is a deduced context. */
4487 data,
4488 NULL,
4491 /* Return zero so that for_each_template_parm will continue the
4492 traversal of the tree; we want to mark *every* template parm. */
4494 }
4496 /* Process the partial specialization DECL. */
4498 static tree
4500 {
4507 tree inner_parms;
4508 tree inst;
4518 /* A concept cannot be specialized. */
4520 {
4523 }
4528 /* We check that each of the template parameters given in the
4529 partial specialization is used in the argument list to the
4530 specialization. For example:
4532 template <class T> struct S;
4533 template <class T> struct S<T*>;
4535 The second declaration is OK because `T*' uses the template
4536 parameter T, whereas
4538 template <class T> struct S<int>;
4540 is no good. Even trickier is:
4542 template <class T>
4543 struct S1
4544 {
4545 template <class U>
4546 struct S2;
4547 template <class U>
4548 struct S2<T>;
4549 };
4551 The S2<T> declaration is actually invalid; it is a
4552 full-specialization. Of course,
4554 template <class U>
4555 struct S2<T (*)(U)>;
4557 or some such would have been OK. */
4565 {
4570 NULL,
4572 }
4575 {
4576 /* One of the template parms was not used in a deduced context in the
4577 specialization. */
4579 {
4583 }
4587 }
4592 /* [temp.class.spec]
4594 The argument list of the specialization shall not be identical to
4595 the implicit argument list of the primary template. */
4596 tree main_args
4599 && (!flag_concepts
4602 {
4606 else
4610 }
4612 /* A partial specialization that replaces multiple parameters of the
4613 primary template with a pack expansion is less specialized for those
4614 parameters. */
4616 {
4618 "primary template because it replaces multiple parameters "
4621 /* Avoid crash in process_partial_specialization. */
4623 }
4625 /* If we aren't in a dependent class, we can actually try deduction. */
4627 /* FIXME we should be able to handle a partial specialization of a
4628 partial instantiation, but currently we can't (c++/41727). */
4631 {
4635 maintmpl);
4636 }
4638 /* [temp.class.spec]
4640 A partially specialized non-type argument expression shall not
4641 involve template parameters of the partial specialization except
4642 when the argument expression is a simple identifier.
4644 The type of a template parameter corresponding to a specialized
4645 non-type argument shall not be dependent on a parameter of the
4646 specialization.
4648 Also, we verify that pack expansions only occur at the
4649 end of the argument list. */
4653 {
4660 {
4661 /* Extract the arguments from the argument pack. We'll be
4662 iterating over these in the following loop. */
4665 }
4668 {
4670 /* Get the Jth argument in the parameter pack. */
4674 {
4675 /* Pack expansions must come at the end of the
4676 argument list. */
4679 {
4683 else
4686 }
4687 }
4690 /* We only care about the pattern. */
4696 /* This next two lines are the `argument expression is not just a
4697 simple identifier' condition and also the `specialized
4698 non-type argument' bit. */
4702 {
4706 arg);
4707 else
4708 {
4709 /* Look at the corresponding template parameter,
4710 marking which template parameters its type depends
4711 upon. */
4715 {
4716 /* We haven't yet initialized TPD2. Do so now. */
4718 /* The number of parameters here is the number in the
4719 main template, which, as checked in the assertion
4720 above, is NARGS. */
4724 }
4726 /* Mark the template parameters. But this time, we're
4727 looking for the template parameters of the main
4728 template, not in the specialization. */
4735 NULL,
4739 {
4740 /* The type depended on some template parameters.
4741 If they are fully specialized in the
4742 specialization, that's OK. */
4751 "type %qT of template argument %qE depends "
4753 "type %qT of template argument %qE depends "
4755 type,
4756 arg);
4757 }
4758 }
4759 }
4760 }
4761 }
4763 /* We should only get here once. */
4767 // Build the template decl.
4776 /* Give template template parms a DECL_CONTEXT of the template
4777 for which they are a parameter. */
4779 {
4783 }
4786 /* We didn't register this in check_explicit_specialization so we could
4787 wait until the constraints were set. */
4789 else
4799 {
4805 {
4813 "declaration of %qD ambiguates earlier template "
4817 "partial specialization of %qD after instantiation "
4819 }
4820 }
4823 }
4825 /* PARM is a template parameter of some form; return the corresponding
4826 TEMPLATE_PARM_INDEX. */
4828 static tree
4830 {
4843 }
4845 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4846 parameter packs used by the template parameter PARM. */
4848 static void
4850 {
4851 /* A type parm can't refer to another parm. */
4855 {
4859 }
4866 }
4868 /* PARM is a template parameter pack. Return any parameter packs used in
4869 its type or the type of any of its template parameters. If there are
4870 any such packs, it will be instantiated into a fixed template parameter
4871 list by partial instantiation rather than be fully deduced. */
4873 tree
4875 {
4876 /* This can only be true in a member template. */
4879 /* This can only be true for a parameter pack. */
4882 /* A type parm can't refer to another parm. */
4896 }
4898 /* Check that a template declaration's use of default arguments and
4899 parameter packs is not invalid. Here, PARMS are the template
4900 parameters. IS_PRIMARY is true if DECL is the thing declared by
4901 a primary template. IS_PARTIAL is true if DECL is a partial
4902 specialization.
4904 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4905 declaration (but not a definition); 1 indicates a declaration, 2
4906 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4907 emitted for extraneous default arguments.
4909 Returns TRUE if there were no errors found, FALSE otherwise. */
4911 bool
4914 {
4917 tree parm_level;
4920 /* [temp.param]
4922 A default template-argument shall not be specified in a
4923 function template declaration or a function template definition, nor
4924 in the template-parameter-list of the definition of a member of a
4925 class template. */
4929 /* You can't have a function template declaration in a local
4930 scope, nor you can you define a member of a class template in a
4931 local scope. */
4939 /* A lambda doesn't have an explicit declaration; don't complain
4940 about the parms of the enclosing class. */
4947 /* If this is either a friend defined in the scope of the class
4948 or a member function. */
4954 /* And, if it was a member function, it really was defined in
4955 the scope of the class. */
4958 /* We already checked these parameters when the template was
4959 declared, so there's no need to do it again now. This function
4960 was defined in class scope, but we're processing its body now
4961 that the class is complete. */
4964 /* Core issue 226 (C++0x only): the following only applies to class
4965 templates. */
4968 {
4969 /* [temp.param]
4971 If a template-parameter has a default template-argument, all
4972 subsequent template-parameters shall have a default
4973 template-argument supplied. */
4975 {
4982 {
4992 {
4994 /* For better subsequent error-recovery, we indicate that
4995 there should have been a default argument. */
4998 }
5000 && !is_friend_decl
5001 /* Don't complain about an enclosing partial
5002 specialization. */
5007 /* A fixed parameter pack will be partially
5008 instantiated into a fixed length list. */
5010 {
5011 /* A primary class template can only have one
5012 parameter pack, at the end of the template
5013 parameter list. */
5021 }
5022 }
5023 }
5024 }
5027 || is_partial
5028 || !is_primary
5030 /* For an ordinary class template, default template arguments are
5031 allowed at the innermost level, e.g.:
5032 template <class T = int>
5033 struct S {};
5034 but, in a partial specialization, they're not allowed even
5035 there, as we have in [temp.class.spec]:
5037 The template parameter list of a specialization shall not
5038 contain default template argument values.
5040 So, for a partial specialization, or for a function template
5041 (in C++98/C++03), we look at all of them. */
5042 ;
5043 else
5044 /* But, for a primary class template that is not a partial
5045 specialization we look at all template parameters except the
5046 innermost ones. */
5049 /* Figure out what error message to issue. */
5064 else
5065 /* Per [temp.param]/9, "A default template-argument shall not be
5066 specified in the template-parameter-lists of the definition of
5067 a member of a class template that appears outside of the member's
5068 class.", thus if we aren't handling a member of a class template
5069 there is no need to examine the parameters. */
5073 /* If we're inside a class definition, there's no need to
5074 examine the parameters to the class itself. On the one
5075 hand, they will be checked when the class is defined, and,
5076 on the other, default arguments are valid in things like:
5077 template <class T = double>
5078 struct S { template <class U> void f(U); };
5079 Here the default argument for `S' has no bearing on the
5080 declaration of `f'. */
5082 else
5083 /* Check everything. */
5089 {
5096 {
5101 {
5103 {
5110 }
5112 /* Clear out the default argument so that we are not
5113 confused later. */
5115 }
5116 }
5118 /* At this point, if we're still interested in issuing messages,
5119 they must apply to classes surrounding the object declared. */
5123 }
5126 }
5128 /* Worker for push_template_decl_real, called via
5129 for_each_template_parm. DATA is really an int, indicating the
5130 level of the parameters we are interested in. If T is a template
5131 parameter of that level, return nonzero. */
5133 static int
5135 {
5141 else
5144 }
5146 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5147 DATA is really an int, indicating the innermost outer level of parameters.
5148 If T is a template parameter of that level or further out, return
5149 nonzero. */
5151 static int
5153 {
5159 else
5162 }
5164 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5165 parameters given by current_template_args, or reuses a
5166 previously existing one, if appropriate. Returns the DECL, or an
5167 equivalent one, if it is replaced via a call to duplicate_decls.
5169 If IS_FRIEND is true, DECL is a friend declaration. */
5171 tree
5173 {
5174 tree tmpl;
5175 tree args;
5176 tree info;
5177 tree ctx;
5181 /* True if the template is a member template, in the sense of
5182 [temp.mem]. */
5188 /* See if this is a partial specialization. */
5201 /* For a friend, we want the context of the friend function, not
5202 the type of which it is a friend. */
5206 /* In the case of a virtual function, we want the class in which
5207 it is defined. */
5209 else
5210 /* Otherwise, if we're currently defining some class, the DECL
5211 is assumed to be a member of the class. */
5220 /* See if this is a primary template. */
5223 /* A friend template that specifies a class context, i.e.
5224 template <typename T> friend void A<T>::f();
5225 is not primary. */
5230 else
5234 {
5241 {
5244 }
5246 {
5248 {
5251 }
5253 {
5254 /* [temp.mem]
5256 A destructor shall not be a member template. */
5259 }
5266 {
5267 /* [basic.stc.dynamic.allocation]
5269 An allocation function can be a function
5270 template. ... Template allocation functions shall
5271 have two or more parameters. */
5274 }
5275 }
5278 {
5279 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5282 {
5288 }
5289 }
5292 /* alias-declaration */
5296 else
5297 {
5300 }
5301 }
5303 /* Check to see that the rules regarding the use of default
5304 arguments are not being violated. */
5308 /* Ensure that there are no parameter packs in the type of this
5309 declaration that have not been expanded. */
5311 {
5312 /* Check each of the arguments individually to see if there are
5313 any bare parameter packs. */
5319 {
5322 {
5323 /* This is a PARM_DECL that contains unexpanded parameter
5324 packs. We have already complained about this in the
5325 check_for_bare_parameter_packs call, so just replace
5326 these types with ERROR_MARK_NODE. */
5329 }
5333 }
5335 /* Check for bare parameter packs in the return type and the
5336 exception specifiers. */
5338 /* Errors were already issued, set return type to int
5339 as the frontend doesn't expect error_mark_node as
5340 the return type. */
5344 }
5349 {
5352 }
5365 {
5370 /* If DECL is a TYPE_DECL for a class-template, then there won't
5371 be DECL_LANG_SPECIFIC. The information equivalent to
5372 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5376 {
5377 /* Since a template declaration already existed for this
5378 class-type, we must be redeclaring it here. Make sure
5379 that the redeclaration is valid. */
5381 current_template_parms,
5383 /* We don't need to create a new TEMPLATE_DECL; just use the
5384 one we already had. */
5386 }
5387 else
5388 {
5390 member_template_p);
5395 {
5396 /* A specialization of a member template of a template
5397 class. */
5401 }
5402 }
5403 }
5404 else
5405 {
5411 {
5414 }
5422 {
5423 tree new_tmpl;
5425 /* The declaration is a specialization of a member
5426 template, declared outside the class. Therefore, the
5427 innermost template arguments will be NULL, so we
5428 replace them with the arguments determined by the
5429 earlier call to check_explicit_specialization. */
5432 new_tmpl
5434 member_template_p);
5444 args,
5447 }
5449 /* Make sure the template headers we got make sense. */
5454 {
5459 }
5460 else
5462 {
5467 {
5471 else
5475 /* Avoid crash in import_export_decl. */
5478 }
5483 /* Can happen in erroneous input. */
5485 else
5487 }
5489 /* Check that the parms are used in the appropriate qualifying scopes
5490 in the declarator. */
5494 {
5500 /* Avoid crash in import_export_decl. */
5503 }
5504 }
5509 /* Push template declarations for global functions and types. Note
5510 that we do not try to push a global template friend declared in a
5511 template class; such a thing may well depend on the template
5512 parameters of the class. */
5515 {
5520 /* Hide template friend classes that haven't been declared yet. */
5522 {
5525 }
5526 }
5529 {
5535 {
5538 /* It is a conversion operator. See if the type converted to
5539 depends on innermost template operands. */
5542 depth))
5544 }
5546 /* Give template template parms a DECL_CONTEXT of the template
5547 for which they are a parameter. */
5550 {
5554 }
5560 }
5562 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5563 back to its most general template. If TMPL is a specialization,
5564 ARGS may only have the innermost set of arguments. Add the missing
5565 argument levels if necessary. */
5573 else
5574 {
5579 }
5582 && !is_friend
5585 /* Set DECL_COMDAT on template instantiations; if we force
5586 them to be emitted by explicit instantiation or -frepo,
5587 mark_needed will tell cgraph to do the right thing. */
5591 }
5593 tree
5595 {
5597 }
5599 /* FN is an inheriting constructor that inherits from the constructor
5600 template INHERITED; turn FN into a constructor template with a matching
5601 template header. */
5603 tree
5605 {
5606 tree inner_parms
5609 tree parms
5620 }
5622 /* Called when a class template TYPE is redeclared with the indicated
5623 template PARMS, e.g.:
5625 template <class T> struct S;
5626 template <class T> struct S {}; */
5628 bool
5630 {
5631 tree tmpl;
5632 tree tmpl_parms;
5636 {
5639 }
5643 /* The type is nested in some template class. Nothing to worry
5644 about here; there are no new template parameters for the nested
5645 type. */
5649 {
5651 tmpl);
5653 }
5659 {
5669 }
5672 {
5673 tree tmpl_parm;
5674 tree parm;
5675 tree tmpl_default;
5676 tree parm_default;
5690 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5691 TEMPLATE_DECL. */
5701 {
5705 }
5708 {
5709 /* We have in [temp.param]:
5711 A template-parameter may not be given default arguments
5712 by two different declarations in the same scope. */
5717 }
5720 /* Update the previous template parameters (which are the ones
5721 that will really count) with the new default value. */
5724 /* Update the new parameters, too; they'll be used as the
5725 parameters for any members. */
5728 /* Give each template template parm in this redeclaration a
5729 DECL_CONTEXT of the template for which they are a parameter. */
5731 {
5734 }
5738 }
5740 // Cannot redeclare a class template with a different set of constraints.
5742 {
5747 }
5750 }
5752 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5753 to be used when the caller has already checked
5754 (processing_template_decl
5755 && !instantiation_dependent_expression_p (expr)
5756 && potential_constant_expression (expr))
5757 and cleared processing_template_decl. */
5759 tree
5761 {
5764 complain,
5768 }
5770 /* Simplify EXPR if it is a non-dependent expression. Returns the
5771 (possibly simplified) expression. */
5773 tree
5775 {
5779 /* If we're in a template, but EXPR isn't value dependent, simplify
5780 it. We're supposed to treat:
5782 template <typename T> void f(T[1 + 1]);
5783 template <typename T> void f(T[2]);
5785 as two declarations of the same function, for example. */
5788 {
5789 processing_template_decl_sentinel s;
5791 }
5793 }
5795 tree
5797 {
5799 }
5801 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5802 an uninstantiated expression. */
5804 tree
5806 {
5810 {
5813 else
5814 {
5815 processing_template_decl_sentinel s;
5817 }
5818 }
5820 }
5822 /* True iff T is a specialization of a variable template. */
5824 bool
5826 {
5831 }
5833 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5834 template declaration, or a TYPE_DECL for an alias declaration. */
5836 bool
5838 {
5846 }
5848 /* Return TRUE iff T is a specialization of an alias template. */
5850 bool
5852 {
5853 /* It's an alias template specialization if it's an alias and its
5854 TYPE_NAME is a specialization of a primary template. */
5860 }
5862 /* An alias template is complex from a SFINAE perspective if a template-id
5863 using that alias can be ill-formed when the expansion is not, as with
5864 the void_t template. We determine this by checking whether the
5865 expansion for the alias template uses all its template parameters. */
5867 struct uses_all_template_parms_data
5868 {
5871 };
5873 static int
5875 {
5883 }
5885 static bool
5887 {
5902 }
5904 /* Return TRUE iff T is a specialization of a complex alias template with
5905 dependent template-arguments. */
5907 bool
5909 {
5922 }
5924 /* Return the number of innermost template parameters in TMPL. */
5926 static int
5928 {
5931 }
5933 /* Return either TMPL or another template that it is equivalent to under DR
5934 1286: An alias that just changes the name of a template is equivalent to
5935 the other template. */
5937 static tree
5939 {
5942 {
5943 /* Determine if the alias is equivalent to an underlying template. */
5955 tree alias_args = INNERMOST_TEMPLATE_ARGS
5960 /* Alias is equivalent. Strip it and repeat. */
5962 }
5965 }
5967 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5968 must be a reference-to-function or a pointer-to-function type, as specified
5969 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5970 and check that the resulting function has external linkage. */
5972 static tree
5974 tsubst_flags_t complain)
5975 {
5978 linkage_kind linkage;
5993 /* [temp.arg.nontype]/1
5995 A template-argument for a non-type, non-template template-parameter
5996 shall be one of:
5997 [...]
5998 -- the address of an object or function with external [C++11: or
5999 internal] linkage. */
6002 {
6004 {
6010 else
6013 }
6015 }
6019 {
6021 {
6026 else
6030 }
6032 }
6040 }
6042 /* Subroutine of convert_nontype_argument.
6043 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6044 Emit an error otherwise. */
6046 static bool
6048 tsubst_flags_t complain)
6049 {
6060 {
6064 }
6066 }
6068 /* Returns TRUE iff the address of OP is value-dependent.
6070 14.6.2.4 [temp.dep.temp]:
6071 A non-integral non-type template-argument is dependent if its type is
6072 dependent or it has either of the following forms
6073 qualified-id
6074 & qualified-id
6075 and contains a nested-name-specifier which specifies a class-name that
6076 names a dependent type.
6078 We generalize this to just say that the address of a member of a
6079 dependent class is value-dependent; the above doesn't cover the
6080 address of a static data member named with an unqualified-id. */
6082 static bool
6084 {
6085 /* We could use get_inner_reference here, but there's no need;
6086 this is only relevant for template non-type arguments, which
6087 can only be expressed as &id-expression. */
6089 {
6093 }
6096 }
6098 /* The next set of functions are used for providing helpful explanatory
6099 diagnostics for failed overload resolution. Their messages should be
6100 indented by two spaces for consistency with the messages in
6101 call.c */
6103 static int
6105 {
6107 }
6109 static int
6111 {
6116 }
6118 static int
6120 {
6122 }
6124 static int
6126 {
6132 }
6134 static int
6136 {
6140 }
6142 static int
6144 {
6147 " template parameter %qD is not a parameter pack, but "
6151 }
6153 static int
6155 {
6158 " template argument %qE does not match "
6162 }
6164 static int
6166 {
6170 }
6172 static int
6174 {
6180 }
6182 static int
6184 {
6186 {
6191 else
6193 " deduced conflicting values for non-type parameter "
6195 }
6197 }
6199 static int
6201 {
6204 " variable-sized array type %qT is not "
6206 arg);
6208 }
6210 static int
6212 {
6216 arg);
6218 }
6220 static int
6222 {
6224 {
6230 else
6235 }
6237 }
6239 static int
6241 {
6243 }
6245 static int
6248 {
6250 }
6252 static int
6255 {
6261 }
6263 static int
6266 {
6269 {
6277 }
6279 }
6281 static int
6283 {
6286 " template parameters of a template template argument are "
6289 }
6291 static int
6293 {
6299 }
6301 static int
6303 {
6308 }
6310 static int
6312 {
6316 arg);
6318 }
6320 /* Attempt to convert the non-type template parameter EXPR to the
6321 indicated TYPE. If the conversion is successful, return the
6322 converted value. If the conversion is unsuccessful, return
6323 NULL_TREE if we issued an error message, or error_mark_node if we
6324 did not. We issue error messages for out-and-out bad template
6325 parameters, but not simply because the conversion failed, since we
6326 might be just trying to do argument deduction. Both TYPE and EXPR
6327 must be non-dependent.
6329 The conversion follows the special rules described in
6330 [temp.arg.nontype], and it is much more strict than an implicit
6331 conversion.
6333 This function is called twice for each template argument (see
6334 lookup_template_class for a more accurate description of this
6335 problem). This means that we need to handle expressions which
6336 are not valid in a C++ source, but can be created from the
6337 first call (for instance, casts to perform conversions). These
6338 hacks can go away after we fix the double coercion problem. */
6340 static tree
6342 {
6343 tree expr_type;
6345 /* Detect immediately string literals as invalid non-type argument.
6346 This special-case is not needed for correctness (we would easily
6347 catch this later), but only to provide better diagnostic for this
6348 common user mistake. As suggested by DR 100, we do not mention
6349 linkage issues in the diagnostic as this is not the point. */
6350 /* FIXME we're making this OK. */
6352 {
6358 }
6360 /* Add the ADDR_EXPR now for the benefit of
6361 value_dependent_expression_p. */
6364 {
6368 }
6370 /* If we are in a template, EXPR may be non-dependent, but still
6371 have a syntactic, rather than semantic, form. For example, EXPR
6372 might be a SCOPE_REF, rather than the VAR_DECL to which the
6373 SCOPE_REF refers. Preserving the qualifying scope is necessary
6374 so that access checking can be performed when the template is
6375 instantiated -- but here we need the resolved form so that we can
6376 convert the argument. */
6389 else
6392 /* If the argument is non-dependent, perform any conversions in
6393 non-dependent context as well. */
6401 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6402 to a non-type argument of "nullptr". */
6406 /* In C++11, integral or enumeration non-type template arguments can be
6407 arbitrary constant expressions. Pointer and pointer to
6408 member arguments can be general constant expressions that evaluate
6409 to a null value, but otherwise still need to be of a specific form. */
6411 {
6413 /* A PTRMEM_CST is already constant, and a valid template
6414 argument for a parameter of pointer to member type, we just want
6415 to leave it in that form rather than lower it to a
6420 {
6424 {
6428 }
6429 }
6431 {
6436 }
6437 }
6439 /* HACK: Due to double coercion, we can get a
6440 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6441 which is the tree that we built on the first call (see
6442 below when coercing to reference to object or to reference to
6443 function). We just strip everything and get to the arg.
6444 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6445 for examples. */
6447 {
6453 {
6454 /* ??? Maybe we could use convert_from_reference here, but we
6455 would need to relax its constraints because the NOP_EXPR
6456 could actually change the type to something more cv-qualified,
6457 and this is not folded by convert_from_reference. */
6462 && (same_type_ignoring_top_level_qualifiers_p
6465 {
6468 }
6469 }
6470 }
6472 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6473 parameter is a pointer to object, through decay and
6474 qualification conversion. Let's strip everything. */
6476 {
6481 {
6482 /* Skip the ADDR_EXPR only if it is part of the decay for
6483 an array. Otherwise, it is part of the original argument
6484 in the source code. */
6489 }
6490 }
6492 /* [temp.arg.nontype]/5, bullet 1
6494 For a non-type template-parameter of integral or enumeration type,
6495 integral promotions (_conv.prom_) and integral conversions
6496 (_conv.integral_) are applied. */
6498 {
6507 /* Notice that there are constant expressions like '4 % 0' which
6508 do not fold into integer constants. */
6511 {
6513 {
6524 /* else cxx_constant_value complained but gave us
6525 a real constant, so go ahead. */
6527 }
6528 else
6530 }
6532 /* Avoid typedef problems. */
6535 }
6536 /* [temp.arg.nontype]/5, bullet 2
6538 For a non-type template-parameter of type pointer to object,
6539 qualification conversions (_conv.qual_) and the array-to-pointer
6540 conversion (_conv.array_) are applied. */
6542 {
6543 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6545 A template-argument for a non-type, non-template template-parameter
6546 shall be one of: [...]
6548 -- the name of a non-type template-parameter;
6549 -- the address of an object or function with external linkage, [...]
6550 expressed as "& id-expression" where the & is optional if the name
6551 refers to a function or array, or if the corresponding
6552 template-parameter is a reference.
6554 Here, we do not care about functions, as they are invalid anyway
6555 for a parameter of type pointer-to-object. */
6558 /* Non-type template parameters are OK. */
6559 ;
6564 {
6566 {
6569 "because %qD is a variable, not the address of "
6572 }
6574 {
6580 }
6581 /* Other values, like integer constants, might be valid
6582 non-type arguments of some other type. */
6584 }
6585 else
6586 {
6587 tree decl;
6592 {
6597 }
6599 {
6605 }
6607 {
6612 }
6613 }
6622 }
6623 /* [temp.arg.nontype]/5, bullet 3
6625 For a non-type template-parameter of type reference to object, no
6626 conversions apply. The type referred to by the reference may be more
6627 cv-qualified than the (otherwise identical) type of the
6628 template-argument. The template-parameter is bound directly to the
6629 template-argument, which must be an lvalue. */
6631 {
6633 expr_type))
6637 {
6642 }
6645 {
6650 }
6652 /* [temp.arg.nontype]/1
6654 A template-argument for a non-type, non-template template-parameter
6655 shall be one of: [...]
6657 -- the address of an object or function with external linkage. */
6660 {
6663 {
6666 "because a reference variable does not have a constant "
6669 }
6670 }
6673 {
6675 {
6681 }
6683 /* DR 1155 allows internal linkage in C++11 and up. */
6686 {
6692 }
6695 }
6696 }
6697 /* [temp.arg.nontype]/5, bullet 4
6699 For a non-type template-parameter of type pointer to function, only
6700 the function-to-pointer conversion (_conv.func_) is applied. If the
6701 template-argument represents a set of overloaded functions (or a
6702 pointer to such), the matching function is selected from the set
6703 (_over.over_). */
6705 {
6706 /* If the argument is a template-id, we might not have enough
6707 context information to decay the pointer. */
6709 {
6713 }
6716 /* Null pointer values are OK in C++11. */
6722 }
6723 /* [temp.arg.nontype]/5, bullet 5
6725 For a non-type template-parameter of type reference to function, no
6726 conversions apply. If the template-argument represents a set of
6727 overloaded functions, the matching function is selected from the set
6728 (_over.over_). */
6730 {
6732 {
6734 {
6739 }
6741 }
6746 }
6747 /* [temp.arg.nontype]/5, bullet 6
6749 For a non-type template-parameter of type pointer to member function,
6750 no conversions apply. If the template-argument represents a set of
6751 overloaded member functions, the matching member function is selected
6752 from the set (_over.over_). */
6754 {
6759 /* [temp.arg.nontype] bullet 1 says the pointer to member
6760 expression must be a pointer-to-member constant. */
6765 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6766 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6770 /* There is no way to disable standard conversions in
6771 resolve_address_of_overloaded_function (called by
6772 instantiate_type). It is possible that the call succeeded by
6773 converting &B::I to &D::I (where B is a base of D), so we need
6774 to reject this conversion here.
6776 Actually, even if there was a way to disable standard conversions,
6777 it would still be better to reject them here so that we can
6778 provide a superior diagnostic. */
6780 {
6782 {
6786 /* If we are just one standard conversion off, explain. */
6790 }
6792 }
6793 }
6794 /* [temp.arg.nontype]/5, bullet 7
6796 For a non-type template-parameter of type pointer to data member,
6797 qualification conversions (_conv.qual_) are applied. */
6799 {
6800 /* [temp.arg.nontype] bullet 1 says the pointer to member
6801 expression must be a pointer-to-member constant. */
6809 }
6811 {
6813 {
6818 }
6820 }
6821 /* A template non-type parameter must be one of the above. */
6822 else
6825 /* Sanity check: did we actually convert the argument to the
6826 right type? */
6830 }
6832 /* Subroutine of coerce_template_template_parms, which returns 1 if
6833 PARM_PARM and ARG_PARM match using the rule for the template
6834 parameters of template template parameters. Both PARM and ARG are
6835 template parameters; the rest of the arguments are the same as for
6836 coerce_template_template_parms.
6837 */
6838 static int
6840 tree arg,
6841 tsubst_flags_t complain,
6842 tree in_decl,
6843 tree outer_args)
6844 {
6853 {
6855 /* We encounter instantiations of templates like
6856 template <template <template <class> class> class TT>
6857 class C; */
6858 {
6865 }
6866 /* Fall through. */
6871 /* Argument is a parameter pack but parameter is not. */
6876 /* The tsubst call is used to handle cases such as
6878 template <int> class C {};
6879 template <class T, template <T> class TT> class D {};
6880 D<int, C> d;
6882 i.e. the parameter list of TT depends on earlier parameters. */
6884 {
6889 }
6893 /* Argument is a parameter pack but parameter is not. */
6900 }
6903 }
6905 /* Coerce template argument list ARGLIST for use with template
6906 template-parameter TEMPL. */
6908 static tree
6910 tsubst_flags_t complain)
6911 {
6912 /* Consider an example where a template template parameter declared as
6914 template <class T, class U = std::allocator<T> > class TT
6916 The template parameter level of T and U are one level larger than
6917 of TT. To proper process the default argument of U, say when an
6918 instantiation `TT<int>' is seen, we need to build the full
6919 arguments containing {int} as the innermost level. Outer levels,
6920 available when not appearing as default template argument, can be
6921 obtained from the arguments of the enclosing template.
6923 Suppose that TT is later substituted with std::vector. The above
6924 instantiation is `TT<int, std::allocator<T> >' with TT at
6925 level 1, and T at level 2, while the template arguments at level 1
6926 becomes {std::vector} and the inner level 2 is {int}. */
6930 {
6932 /* We want arguments for the partial specialization, not arguments for
6933 the primary template. */
6935 else
6937 }
6939 {
6940 /* This is an argument of the current template, so we haven't set
6941 DECL_CONTEXT yet. */
6942 tree relevant_template_parms;
6944 /* Parameter levels that are greater than the level of the given
6945 template template parm are irrelevant. */
6952 }
6959 complain,
6962 }
6964 /* A cache of template template parameters with match-all default
6965 arguments. */
6967 static void
6969 {
6973 }
6974 static tree
6976 {
6981 }
6983 /* T is a bound template template-parameter. Copy its arguments into default
6984 arguments of the template template-parameter's template parameters. */
6986 static tree
6988 {
7011 {
7014 {
7017 }
7018 }
7022 }
7024 /* ARG is a bound potential template template-argument, and PARGS is a list
7025 of arguments for the corresponding template template-parameter. Adjust
7026 PARGS as appropriate for application to ARG's template, and if ARG is a
7027 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7028 arguments to the template template parameter. */
7030 static tree
7032 {
7036 {
7037 /* When comparing two template template-parameters in partial ordering,
7038 rewrite the one currently being used as an argument to have default
7039 arguments for all parameters. */
7045 }
7046 else
7047 {
7048 tree aparms
7053 }
7056 }
7058 /* Subroutine of unify for the case when PARM is a
7059 BOUND_TEMPLATE_TEMPLATE_PARM. */
7061 static int
7064 {
7068 /* The template template parm might be variadic and the argument
7069 not, so flatten both argument lists. */
7075 {
7076 /* In keeping with P0522R0, adjust P's template arguments
7077 to apply to A's template; then flatten it again. */
7080 }
7086 /* If the P0522 adjustment eliminated a pack expansion, deduce
7087 empty packs. */
7095 }
7097 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7098 template template parameters. Both PARM_PARMS and ARG_PARMS are
7099 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7100 or PARM_DECL.
7102 Consider the example:
7103 template <class T> class A;
7104 template<template <class U> class TT> class B;
7106 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7107 the parameters to A, and OUTER_ARGS contains A. */
7109 static int
7111 tree arg_parms,
7112 tsubst_flags_t complain,
7113 tree in_decl,
7114 tree outer_args)
7115 {
7127 {
7128 /* P0522R0: A template template-parameter P is at least as specialized as
7129 a template template-argument A if, given the following rewrite to two
7130 function templates, the function template corresponding to P is at
7131 least as specialized as the function template corresponding to A
7132 according to the partial ordering rules for function templates
7133 ([temp.func.order]). Given an invented class template X with the
7134 template parameter list of A (including default arguments):
7136 * Each of the two function templates has the same template parameters,
7137 respectively, as P or A.
7139 * Each function template has a single function parameter whose type is
7140 a specialization of X with template arguments corresponding to the
7141 template parameters from the respective function template where, for
7142 each template parameter PP in the template parameter list of the
7143 function template, a corresponding template argument AA is formed. If
7144 PP declares a parameter pack, then AA is the pack expansion
7145 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7147 If the rewrite produces an invalid type, then P is not at least as
7148 specialized as A. */
7150 /* So coerce P's args to apply to A's parms, and then deduce between A's
7151 args and the converted args. If that succeeds, A is at least as
7152 specialized as P, so they match.*/
7159 {
7165 }
7166 }
7168 /* Determine whether we have a parameter pack at the end of the
7169 template template parameter's template parameter list. */
7171 {
7178 {
7192 }
7193 }
7199 /* Check all of the template parameters except the parameter pack at
7200 the end (if any). */
7202 {
7211 outer_args))
7214 }
7217 {
7218 /* Check each of the template parameters in the template
7219 argument against the template parameter pack at the end of
7220 the template template parameter. */
7227 {
7234 outer_args))
7236 }
7237 }
7240 }
7242 /* Verifies that the deduced template arguments (in TARGS) for the
7243 template template parameters (in TPARMS) represent valid bindings,
7244 by comparing the template parameter list of each template argument
7245 to the template parameter list of its corresponding template
7246 template parameter, in accordance with DR150. This
7247 routine can only be called after all template arguments have been
7248 deduced. It will return TRUE if all of the template template
7249 parameter bindings are okay, FALSE otherwise. */
7250 bool
7252 {
7256 /* We're dealing with template parms in this process. */
7262 {
7267 {
7272 {
7273 /* Look inside the argument pack. */
7276 }
7279 {
7283 /* Extract the next argument from the argument
7284 pack. */
7288 /* Look at the pattern of the pack expansion. */
7291 /* Extract the template parameters from the template
7292 argument. */
7298 /* Verify that we can coerce the template template
7299 parameters from the template argument to the template
7300 parameter. This requires an exact match. */
7302 && !coerce_template_template_parms
7304 targ_parms,
7305 tf_none,
7306 tparm,
7307 targs))
7308 {
7311 }
7312 }
7313 }
7314 }
7316 out:
7320 }
7322 /* Since type attributes aren't mangled, we need to strip them from
7323 template type arguments. */
7325 static tree
7327 {
7337 }
7339 /* And from inside dependent non-type arguments like sizeof(Type). */
7341 static tree
7343 {
7353 }
7355 // A template declaration can be substituted for a constrained
7356 // template template parameter only when the argument is more
7357 // constrained than the parameter.
7358 static bool
7360 {
7363 /* For now, allow constrained template template arguments
7364 and unconstrained template template parameters. */
7370 // If the template parameter is constrained, we need to rewrite its
7371 // constraints in terms of the ARG's template parameters. This ensures
7372 // that all of the template parameter types will have the same depth.
7373 //
7374 // Note that this is only valid when coerce_template_template_parm is
7375 // true for the innermost template parameters of PARM and ARG. In other
7376 // words, because coercion is successful, this conversion will be valid.
7378 {
7385 }
7388 }
7390 // Convert a placeholder argument into a binding to the original
7391 // parameter. The original parameter is saved as the TREE_TYPE of
7392 // ARG.
7395 {
7398 }
7400 /* Convert the indicated template ARG as necessary to match the
7401 indicated template PARM. Returns the converted ARG, or
7402 error_mark_node if the conversion was unsuccessful. Error and
7403 warning messages are issued under control of COMPLAIN. This
7404 conversion is for the Ith parameter in the parameter list. ARGS is
7405 the full set of template arguments deduced so far. */
7407 static tree
7409 tree arg,
7410 tree args,
7411 tsubst_flags_t complain,
7413 tree in_decl)
7414 {
7415 tree orig_arg;
7416 tree val;
7422 /* Trivially convert placeholders. */
7431 {
7432 /* The template argument was the name of some
7433 member function. That's usually
7434 invalid, but static members are OK. In any
7435 case, grab the underlying fields/functions
7436 and issue an error later if required. */
7439 }
7447 /* When determining whether an argument pack expansion is a template,
7448 look at the pattern. */
7452 /* Deal with an injected-class-name used as a template template arg. */
7454 {
7457 {
7467 }
7468 }
7470 is_tmpl_type =
7486 {
7488 {
7492 }
7495 "to refer to a type member of a template parameter, "
7500 typename_type,
7501 complain);
7504 }
7506 {
7508 {
7510 {
7522 else
7525 }
7526 }
7528 }
7530 {
7532 {
7539 else
7542 }
7544 }
7547 {
7549 {
7553 /* The number of argument required is not known yet.
7554 Just accept it for now. */
7556 else
7557 {
7559 tree argparm;
7561 /* Strip alias templates that are equivalent to another
7562 template. */
7568 args))
7569 {
7572 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7573 TEMPLATE_DECL. */
7575 {
7580 }
7581 }
7582 else
7583 {
7585 {
7592 }
7595 }
7597 // Check that the constraints are compatible before allowing the
7598 // substitution.
7601 {
7603 {
7609 }
7611 }
7612 }
7613 }
7614 else
7616 /* We only form one instance of each template specialization.
7617 Therefore, if we use a non-canonical variant (i.e., a
7618 typedef), any future messages referring to the type will use
7619 the typedef, which is confusing if those future uses do not
7620 themselves also use the typedef. */
7623 }
7624 else
7625 {
7629 {
7631 /* There's nothing to check for an auto argument pack. */
7637 }
7638 else
7645 {
7648 else
7649 {
7650 /* Not sure if this is reachable, but it doesn't hurt
7651 to be robust. */
7654 }
7655 }
7658 /* We used to call digest_init here. However, digest_init
7659 will report errors, which we don't want when complain
7660 is zero. More importantly, digest_init will try too
7661 hard to convert things: for example, `0' should not be
7662 converted to pointer type at this point according to
7663 the standard. Accepting this is not merely an
7664 extension, since deciding whether or not these
7665 conversions can occur is part of determining which
7666 function template to call, or whether a given explicit
7667 argument specification is valid. */
7669 else
7679 {
7680 /* Reject template arguments that are references to built-in
7681 functions with no library fallbacks. */
7690 }
7693 {
7694 /* Strip typedefs from the SCOPE_REF. */
7697 complain);
7700 }
7701 }
7704 }
7706 /* Coerces the remaining template arguments in INNER_ARGS (from
7707 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7708 Returns the coerced argument pack. PARM_IDX is the position of this
7709 parameter in the template parameter list. ARGS is the original
7710 template argument list. */
7711 static tree
7714 tree args,
7715 tree inner_args,
7717 tree new_args,
7719 tree in_decl,
7720 tsubst_flags_t complain)
7721 {
7724 tree packed_args;
7725 tree argument_pack;
7732 {
7733 /* When the template parameter is a non-type template parameter pack
7734 or template template parameter pack whose type or template
7735 parameters use parameter packs, we know exactly how many arguments
7736 we are looking for. Build a vector of the instantiated decls for
7737 these template parameters in PACKED_PARMS. */
7738 /* We can't use make_pack_expansion here because it would interpret a
7739 _DECL as a use rather than a declaration. */
7753 /* If we're doing a partial instantiation of a member template,
7754 verify that all of the types used for the non-type
7755 template parameter pack are, in fact, valid for non-type
7756 template parameters. */
7759 {
7762 {
7766 }
7767 /* We don't know how many args we have yet, just
7768 use the unconverted ones for now. */
7770 }
7773 }
7774 /* Check if we have a placeholder pack, which indicates we're
7775 in the context of a introduction list. In that case we want
7776 to match this pack to the single placeholder. */
7780 {
7783 }
7784 else
7787 /* Convert the remaining arguments, which will be a part of the
7788 parameter pack "parm". */
7791 {
7797 {
7798 /* Once we've packed as many args as we have types, stop. */
7802 /* We don't know how many args we have yet, just
7803 use the unconverted ones for now. */
7805 else
7807 }
7810 {
7813 }
7814 else
7817 in_decl);
7821 }
7825 {
7830 }
7835 else
7836 {
7841 }
7848 }
7850 /* Returns the number of pack expansions in the template argument vector
7851 ARGS. */
7853 static int
7855 {
7860 {
7864 }
7866 }
7868 /* Convert all template arguments to their appropriate types, and
7869 return a vector containing the innermost resulting template
7870 arguments. If any error occurs, return error_mark_node. Error and
7871 warning messages are issued under control of COMPLAIN.
7873 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7874 for arguments not specified in ARGS. Otherwise, if
7875 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7876 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7877 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7878 ARGS. */
7880 static tree
7882 tree args,
7883 tree in_decl,
7884 tsubst_flags_t complain,
7887 {
7889 tree orig_inner_args;
7890 tree inner_args;
7891 tree new_args;
7892 tree new_inner_args;
7896 /* When used as a boolean value, indicates whether this is a
7897 variadic template parameter list. Since it's an int, we can also
7898 subtract it from nparms to get the number of non-variadic
7899 parameters. */
7904 /* Likewise for parameters with default arguments. */
7912 /* Determine if there are any parameter packs or default arguments. */
7914 {
7922 }
7925 /* If there are no parameters that follow a parameter pack, we need to
7926 expand any argument packs so that we can deduce a parameter pack from
7927 some non-packed args followed by an argument pack, as in variadic85.C.
7928 If there are such parameters, we need to leave argument packs intact
7929 so the arguments are assigned properly. This can happen when dealing
7930 with a nested class inside a partial specialization of a class
7931 template, as in variadic92.C, or when deducing a template parameter pack
7932 from a sub-declarator, as in variadic114.C. */
7936 /* Count any pack expansion args. */
7942 && require_all_args
7943 && !variadic_args_p
7944 && (!use_default_args
7947 {
7949 {
7951 {
7955 }
7956 else
7963 }
7966 }
7967 /* We can't pass a pack expansion to a non-pack parameter of an alias
7968 template (DR 1430). */
7972 && variadic_args_p
7974 {
7976 {
7978 {
7984 {
7987 "pack expansion argument for non-pack parameter "
7989 else
7991 "pack expansion argument for non-pack parameter "
7995 }
7996 }
7998 found:;
7999 }
8001 }
8003 /* We need to evaluate the template arguments, even though this
8004 template-id may be nested within a "sizeof". */
8013 {
8014 tree arg;
8015 tree parm;
8017 /* Get the Ith template parameter. */
8021 {
8024 }
8026 /* Calculate the next argument. */
8029 else
8034 {
8035 /* Some arguments will be placed in the
8036 template parameter pack PARM. */
8043 {
8044 /* We don't know how many args we have yet, just use the
8045 unconverted (and still packed) ones for now. */
8049 }
8053 /* Store this argument. */
8055 {
8056 lost++;
8057 /* We are done with all of the arguments. */
8059 }
8060 else
8061 {
8064 }
8067 }
8069 {
8071 {
8072 /* "If every valid specialization of a variadic template
8073 requires an empty template parameter pack, the template is
8074 ill-formed, no diagnostic required." So check that the
8075 pattern works with this parameter. */
8080 in_decl);
8082 {
8087 }
8089 /* Recover from missing typename. */
8093 /* We don't know how many args we have yet, just
8094 use the unconverted ones for now. */
8098 }
8099 }
8101 {
8102 /* There must be a default arg in this case. */
8105 /* The position of the first default template argument,
8106 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8107 Record that. */
8111 }
8112 else
8116 {
8119 }
8121 /* This only occurs if there was an error in the template
8122 parameter list itself (which we would already have
8123 reported) that we are trying to recover from, e.g., a class
8124 template with a parameter list such as
8125 template<typename..., typename>. */
8127 else
8133 lost++;
8135 }
8140 {
8142 {
8147 }
8149 }
8159 }
8161 /* Convert all template arguments to their appropriate types, and
8162 return a vector containing the innermost resulting template
8163 arguments. If any error occurs, return error_mark_node. Error and
8164 warning messages are not issued.
8166 Note that no function argument deduction is performed, and default
8167 arguments are used to fill in unspecified arguments. */
8168 tree
8170 {
8172 }
8174 /* Convert all template arguments to their appropriate type, and
8175 instantiate default arguments as needed. This returns a vector
8176 containing the innermost resulting template arguments, or
8177 error_mark_node if unsuccessful. */
8178 tree
8180 tsubst_flags_t complain)
8181 {
8183 }
8185 /* Like coerce_template_parms. If PARMS represents all template
8186 parameters levels, this function returns a vector of vectors
8187 representing all the resulting argument levels. Note that in this
8188 case, only the innermost arguments are coerced because the
8189 outermost ones are supposed to have been coerced already.
8191 Otherwise, if PARMS represents only (the innermost) vector of
8192 parameters, this function returns a vector containing just the
8193 innermost resulting arguments. */
8195 static tree
8197 tree args,
8198 tree in_decl,
8199 tsubst_flags_t complain,
8202 {
8205 tree coerced_args;
8208 {
8210 tree level;
8216 {
8217 tree l;
8221 require_all_args,
8222 use_default_args);
8223 else
8230 }
8231 }
8232 else
8235 require_all_args,
8236 use_default_args);
8238 }
8240 /* Returns 1 if template args OT and NT are equivalent. */
8242 int
8244 {
8253 /* For member templates */
8262 {
8279 }
8283 {
8286 /* Don't treat an alias template specialization with dependent
8287 arguments as equivalent to its underlying type when used as a
8288 template argument; we need them to be distinct so that we
8289 substitute into the specialization arguments at instantiation
8290 time. And aliases can't be equivalent without being ==, so
8291 we don't need to look any deeper. */
8294 else
8296 }
8299 else
8300 {
8301 /* Try to treat a template non-type argument that has been converted
8302 to the parameter type as equivalent to one that hasn't yet. */
8315 }
8316 }
8318 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8319 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8320 NEWARG_PTR with the offending arguments if they are non-NULL. */
8322 int
8325 {
8338 {
8343 {
8349 }
8350 }
8352 }
8354 static void
8356 {
8366 /* We are called both from instantiate_decl, where we've already had a
8367 tinst_level pushed, and instantiate_template, where we haven't.
8368 Compensate. */
8379 else
8388 }
8391 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8392 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8393 documentation for TEMPLATE_ID_EXPR. */
8395 tree
8397 {
8398 tree type;
8406 {
8409 }
8412 {
8414 unknown_type_node,
8416 arglist);
8418 }
8425 }
8427 /* Within the scope of a template class S<T>, the name S gets bound
8428 (in build_self_reference) to a TYPE_DECL for the class, not a
8429 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8430 or one of its enclosing classes, and that type is a template,
8431 return the associated TEMPLATE_DECL. Otherwise, the original
8432 DECL is returned.
8434 Also handle the case when DECL is a TREE_LIST of ambiguous
8435 injected-class-names from different bases. */
8437 tree
8439 {
8443 /* DR 176: A lookup that finds an injected-class-name (10.2
8444 [class.member.lookup]) can result in an ambiguity in certain cases
8445 (for example, if it is found in more than one base class). If all of
8446 the injected-class-names that are found refer to specializations of
8447 the same class template, and if the name is followed by a
8448 template-argument-list, the reference refers to the class template
8449 itself and not a specialization thereof, and is not ambiguous. */
8451 {
8454 {
8460 }
8463 else
8465 }
8471 }
8473 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8474 parameters, find the desired type.
8476 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8478 IN_DECL, if non-NULL, is the template declaration we are trying to
8479 instantiate.
8481 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8482 the class we are looking up.
8484 Issue error and warning messages under control of COMPLAIN.
8486 If the template class is really a local class in a template
8487 function, then the FUNCTION_CONTEXT is the function in which it is
8488 being instantiated.
8490 ??? Note that this function is currently called *twice* for each
8491 template-id: the first time from the parser, while creating the
8492 incomplete type (finish_template_type), and the second type during the
8493 real instantiation (instantiate_template_class). This is surely something
8494 that we want to avoid. It also causes some problems with argument
8495 coercion (see convert_nontype_argument for more information on this). */
8497 static tree
8500 {
8502 tree t;
8505 spec_entry elt;
8506 hashval_t hash;
8509 {
8513 else
8514 {
8521 }
8524 }
8526 {
8529 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8530 an implicit typename for the second A. Deal with it. */
8535 {
8538 }
8539 }
8542 {
8545 }
8547 {
8551 }
8553 {
8556 }
8558 /* Issue an error message if we didn't find a template. */
8560 {
8564 }
8567 /* Make sure it's a user visible template, if it was named by
8568 the user. */
8571 {
8573 {
8577 }
8579 }
8583 /* An alias that just changes the name of a template is equivalent to the
8584 other template, so if any of the arguments are pack expansions, strip
8585 the alias to avoid problems with a pack expansion passed to a non-pack
8586 alias template parameter (DR 1430). */
8591 {
8592 tree parm;
8601 }
8602 else
8603 {
8605 tree gen_tmpl;
8606 tree type_decl;
8614 /* An error occurred while building the template TEMPL, and a
8615 diagnostic has most certainly been emitted for that
8616 already. Let's propagate that error. */
8625 {
8626 /* We've been given an incomplete set of template arguments.
8627 For example, given:
8629 template <class T> struct S1 {
8630 template <class U> struct S2 {};
8631 template <class U> struct S2<U*> {};
8632 };
8634 we will be called with an ARGLIST of `U*', but the
8635 TEMPLATE will be `template <class T> template
8636 <class U> struct S1<T>::S2'. We must fill in the missing
8637 arguments. */
8641 }
8643 /* Now we should have enough arguments. */
8646 /* From here on, we're only interested in the most general
8647 template. */
8649 /* Calculate the BOUND_ARGS. These will be the args that are
8650 actually tsubst'd into the definition to create the
8651 instantiation. */
8653 complain,
8658 /* We were unable to bind the arguments. */
8661 /* In the scope of a template class, explicit references to the
8662 template class refer to the type of the template, not any
8663 instantiation of it. For example, in:
8665 template <class T> class C { void f(C<T>); }
8667 the `C<T>' is just the same as `C'. Outside of the
8668 class, however, such a reference is an instantiation. */
8672 {
8677 }
8679 /* If we already have this specialization, return it. */
8689 /* If the the template's constraints are not satisfied,
8690 then we cannot form a valid type.
8692 Note that the check is deferred until after the hash
8693 lookup. This prevents redundant checks on previously
8694 instantiated specializations. */
8696 {
8698 {
8701 }
8703 }
8707 /* If the deduced arguments are invalid, then the binding
8708 failed. */
8712 complain))
8719 {
8724 }
8734 /* Create the type. */
8736 {
8737 /* The user referred to a specialization of an alias
8738 template represented by GEN_TMPL.
8740 [temp.alias]/2 says:
8742 When a template-id refers to the specialization of an
8743 alias template, it is equivalent to the associated
8744 type obtained by substitution of its
8745 template-arguments for the template-parameters in the
8746 type-id of the alias template. */
8749 /* Note that the call above (by indirectly calling
8750 register_specialization in tsubst_decl) registers the
8751 TYPE_DECL representing the specialization of the alias
8752 template. So next time someone substitutes ARGLIST for
8753 the template parms into the alias template (GEN_TMPL),
8754 she'll get that TYPE_DECL back. */
8758 }
8760 {
8762 {
8773 }
8774 else
8775 {
8776 /* We don't want to call start_enum for this type, since
8777 the values for the enumeration constants may involve
8778 template parameters. And, no one should be interested
8779 in the enumeration constants for such a type. */
8782 }
8786 }
8788 {
8794 /* A local class. Make sure the decl gets registered properly. */
8799 /* This instantiation is another name for the primary
8800 template type. Set the TYPE_CANONICAL field
8801 appropriately. */
8804 /* Some of the template arguments require structural
8805 equality testing, so this template class requires
8806 structural equality testing. */
8808 }
8809 else
8812 /* If we called start_enum or pushtag above, this information
8813 will already be set up. */
8815 {
8822 }
8823 else
8827 {
8833 {
8836 }
8837 }
8841 {
8845 {
8846 tree attributes
8854 }
8855 }
8857 /* Let's consider the explicit specialization of a member
8858 of a class template specialization that is implicitly instantiated,
8859 e.g.:
8860 template<class T>
8861 struct S
8862 {
8863 template<class U> struct M {}; //#0
8864 };
8866 template<>
8867 template<>
8868 struct S<int>::M<char> //#1
8869 {
8870 int i;
8871 };
8872 [temp.expl.spec]/4 says this is valid.
8874 In this case, when we write:
8875 S<int>::M<char> m;
8877 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8878 the one of #0.
8880 When we encounter #1, we want to store the partial instantiation
8881 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8883 For all cases other than this "explicit specialization of member of a
8884 class template", we just want to store the most general template into
8885 the CLASSTYPE_TI_TEMPLATE of M.
8887 This case of "explicit specialization of member of a class template"
8888 only happens when:
8889 1/ the enclosing class is an instantiation of, and therefore not
8890 the same as, the context of the most general template, and
8891 2/ we aren't looking at the partial instantiation itself, i.e.
8892 the innermost arguments are not the same as the innermost parms of
8893 the most general template.
8895 So it's only when 1/ and 2/ happens that we want to use the partial
8896 instantiation of the member template in lieu of its most general
8897 template. */
8901 /* the enclosing class must be an instantiation... */
8904 {
8908 tree partial_inst_args =
8915 use_partial_inst_tmpl =
8916 /*...and we must not be looking at the partial instantiation
8917 itself. */
8919 partial_inst_args);
8920 }
8923 /* This case is easy; there are no member templates involved. */
8925 else
8926 {
8927 /* This is a full instantiation of a member template. Find
8928 the partial instantiation of which this is an instance. */
8930 /* Temporarily reduce by one the number of levels in the ARGLIST
8931 so as to avoid comparing the last set of arguments. */
8935 /* FOUND is either a proper class type, or an alias
8936 template specialization. In the later case, it's a
8937 TYPE_DECL, resulting from the substituting of arguments
8938 for parameters in the TYPE_DECL of the alias template
8939 done earlier. So be careful while getting the template
8940 of FOUND. */
8942 ? found
8946 }
8948 // Build template info for the new specialization.
8957 /* Note this use of the partial instantiation so we can check it
8958 later in maybe_process_partial_specialization. */
8965 /* Now that the type has been registered on the instantiations
8966 list, we set up the enumerators. Because the enumeration
8967 constants may involve the enumeration type itself, we make
8968 sure to register the type first, and then create the
8969 constants. That way, doing tsubst_expr for the enumeration
8970 constants won't result in recursive calls here; we'll find
8971 the instantiation and exit above. */
8975 /* If the type makes use of template parameters, the
8976 code that generates debugging information will crash. */
8979 /* Possibly limit visibility based on template args. */
8986 }
8987 }
8989 /* Wrapper for lookup_template_class_1. */
8991 tree
8994 {
8995 tree ret;
9001 }
9003 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9005 tree
9007 {
9008 /* The type of the expression is NULL_TREE since the template-id could refer
9009 to an explicit or partial specialization. */
9012 /* Except that concepts are always bool. */
9015 }
9017 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9019 tree
9021 {
9025 /* We never want to return a VAR_DECL for a variable concept, since they
9026 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9041 {
9043 {
9046 }
9048 }
9050 /* If a template-id refers to a specialization of a variable
9051 concept, then the expression is true if and only if the
9052 concept's constraints are satisfied by the given template
9053 arguments.
9055 NOTE: This is an extension of Concepts Lite TS that
9056 allows constraints to be used in expressions. */
9058 {
9061 }
9064 }
9066 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9067 TARGS template args, and instantiate it if it's not dependent. */
9069 tree
9071 tsubst_flags_t complain)
9072 {
9075 {
9078 }
9081 }
9083 \f
9084 struct pair_fn_data
9085 {
9086 tree_fn_t fn;
9087 tree_fn_t any_fn;
9089 /* True when we should also visit template parameters that occur in
9090 non-deduced contexts. */
9093 };
9095 /* Called from for_each_template_parm via walk_tree. */
9097 static tree
9099 {
9106 #define WALK_SUBTREE(NODE) \
9107 do \
9108 { \
9109 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9110 pfd->include_nondeduced_p, \
9111 pfd->any_fn); \
9112 if (result) goto out; \
9113 } \
9114 while (0)
9124 {
9128 /* Fall through. */
9134 else
9144 /* Since we're not going to walk subtrees, we have to do this
9145 explicitly here. */
9147 /* Fall through. */
9150 /* Check the return type. */
9153 /* Check the parameter types. Since default arguments are not
9154 instantiated until they are needed, the TYPE_ARG_TYPES may
9155 contain expressions that involve template parameters. But,
9156 no-one should be looking at them yet. And, once they're
9157 instantiated, they don't contain template parameters, so
9158 there's no point in looking at them then, either. */
9159 {
9160 tree parm;
9165 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9166 want walk_tree walking into them itself. */
9168 }
9171 {
9175 }
9192 /* Fall through. */
9204 /* Record template parameters such as `T' inside `TT<T>'. */
9206 /* Fall through. */
9218 /* A template template parameter is encountered. */
9222 /* Already substituted template template parameter */
9227 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9228 partial instantiation. */
9240 /* If there's no type, then this thing must be some expression
9241 involving template parameters. */
9263 }
9265 #undef WALK_SUBTREE
9267 /* We didn't find any template parameters we liked. */
9268 out:
9270 }
9272 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9273 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9274 call FN with the parameter and the DATA.
9275 If FN returns nonzero, the iteration is terminated, and
9276 for_each_template_parm returns 1. Otherwise, the iteration
9277 continues. If FN never returns a nonzero value, the value
9278 returned by for_each_template_parm is 0. If FN is NULL, it is
9279 considered to be the function which always returns 1.
9281 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9282 parameters that occur in non-deduced contexts. When false, only
9283 visits those template parameters that can be deduced. */
9285 static tree
9289 tree_fn_t any_fn)
9290 {
9292 tree result;
9294 /* Set up. */
9300 /* Walk the tree. (Conceptually, we would like to walk without
9301 duplicates, but for_each_template_parm_r recursively calls
9302 for_each_template_parm, so we would need to reorganize a fair
9303 bit to use walk_tree_without_duplicates, so we keep our own
9304 visited list.) */
9307 else
9310 for_each_template_parm_r,
9314 /* Clean up. */
9316 {
9319 }
9322 }
9324 /* Returns true if T depends on any template parameter. */
9326 int
9328 {
9358 else
9359 {
9362 }
9367 }
9369 /* Returns true iff current_function_decl is an incompletely instantiated
9370 template. Useful instead of processing_template_decl because the latter
9371 is set to 0 during instantiate_non_dependent_expr. */
9373 bool
9375 {
9384 }
9386 /* Returns true if T depends on any template parameter with level LEVEL. */
9388 bool
9390 {
9393 }
9395 /* Returns true if the signature of DECL depends on any template parameter from
9396 its enclosing class. */
9398 bool
9400 {
9410 template_parm_outer_level,
9420 }
9422 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9423 ill-formed translation unit, i.e. a variable or function that isn't
9424 usable in a constant expression. */
9428 {
9432 }
9434 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9435 neglectable and instantiated from within an erroneous instantiation. */
9437 static bool
9439 {
9450 }
9458 /* We're starting to instantiate D; record the template instantiation context
9459 for diagnostics and to restore it later. */
9461 bool
9463 {
9465 }
9467 /* We're starting to instantiate D; record the template instantiation context
9468 at LOC for diagnostics and to restore it later. */
9470 bool
9472 {
9476 {
9477 /* Tell error.c not to try to instantiate any templates. */
9480 "template instantiation depth exceeds maximum of %d"
9482 max_tinst_depth);
9484 }
9486 /* If the current instantiation caused problems, don't let it instantiate
9487 anything else. Do allow deduction substitution and decls usable in
9488 constant expressions. */
9492 /* When not -quiet, dump template instantiations other than functions, since
9493 announce_function will take care of those. */
9512 }
9514 /* We're done instantiating this template; return to the instantiation
9515 context. */
9517 void
9519 {
9520 /* Restore the filename and line number stashed away when we started
9521 this instantiation. */
9525 }
9527 /* We're instantiating a deferred template; restore the template
9528 instantiation context in which the instantiation was requested, which
9529 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9531 static tree
9533 {
9545 }
9547 /* Returns the TINST_LEVEL which gives the original instantiation
9548 context. */
9552 {
9558 }
9560 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9561 vector of template arguments, as for tsubst.
9563 Returns an appropriate tsubst'd friend declaration. */
9565 static tree
9567 {
9568 tree new_friend;
9573 /* This was a friend declared with an explicit template
9574 argument list, e.g.:
9576 friend void f<>(T);
9578 to indicate that f was a template instantiation, not a new
9579 function declaration. Now, we have to figure out what
9580 instantiation of what template. */
9581 {
9583 tree new_args;
9584 tree tmpl;
9587 /* Friend functions are looked up in the containing namespace scope.
9588 We must enter that scope, to avoid finding member functions of the
9589 current class with same name. */
9604 tsk_none);
9606 }
9610 /* The NEW_FRIEND will look like an instantiation, to the
9611 compiler, but is not an instantiation from the point of view of
9612 the language. For example, we might have had:
9614 template <class T> struct S {
9615 template <class U> friend void f(T, U);
9616 };
9618 Then, in S<int>, template <class U> void f(int, U) is not an
9619 instantiation of anything. */
9625 {
9629 }
9631 /* The mangled name for the NEW_FRIEND is incorrect. The function
9632 is not a template instantiation and should not be mangled like
9633 one. Therefore, we forget the mangling here; we'll recompute it
9634 later if we need it. */
9636 {
9639 }
9642 {
9643 tree old_decl;
9644 tree new_friend_template_info;
9645 tree new_friend_result_template_info;
9646 tree ns;
9649 /* We must save some information from NEW_FRIEND before calling
9650 duplicate decls since that function will free NEW_FRIEND if
9651 possible. */
9653 new_friend_is_defn =
9658 {
9659 /* This declaration is a `primary' template. */
9662 new_friend_result_template_info
9664 }
9665 else
9668 /* Inside pushdecl_namespace_level, we will push into the
9669 current namespace. However, the friend function should go
9670 into the namespace of the template. */
9680 {
9681 /* This new friend declaration matched an existing
9682 declaration. For example, given:
9684 template <class T> void f(T);
9685 template <class U> class C {
9686 template <class T> friend void f(T) {}
9687 };
9689 the friend declaration actually provides the definition
9690 of `f', once C has been instantiated for some type. So,
9691 old_decl will be the out-of-class template declaration,
9692 while new_friend is the in-class definition.
9694 But, if `f' was called before this point, the
9695 instantiation of `f' will have DECL_TI_ARGS corresponding
9696 to `T' but not to `U', references to which might appear
9697 in the definition of `f'. Previously, the most general
9698 template for an instantiation of `f' was the out-of-class
9699 version; now it is the in-class version. Therefore, we
9700 run through all specialization of `f', adding to their
9701 DECL_TI_ARGS appropriately. In particular, they need a
9702 new set of outer arguments, corresponding to the
9703 arguments for this class instantiation.
9705 The same situation can arise with something like this:
9707 friend void f(int);
9708 template <class T> class C {
9709 friend void f(T) {}
9710 };
9712 when `C<int>' is instantiated. Now, `f(int)' is defined
9713 in the class. */
9716 /* On the other hand, if the in-class declaration does
9717 *not* provide a definition, then we don't want to alter
9718 existing definitions. We can just leave everything
9719 alone. */
9720 ;
9721 else
9722 {
9726 /* Overwrite whatever template info was there before, if
9727 any, with the new template information pertaining to
9728 the declaration. */
9732 {
9733 /* We should have called reregister_specialization in
9734 duplicate_decls. */
9739 /* Instantiate it if the global has already been used. */
9743 }
9744 else
9745 {
9746 tree t;
9748 /* Indicate that the old function template is a partial
9749 instantiation. */
9757 /* Reassign any specializations already in the hash table
9758 to the new more general template, and add the
9759 additional template args. */
9763 {
9765 spec_entry elt;
9777 register_specialization
9780 }
9782 }
9783 }
9785 /* The information from NEW_FRIEND has been merged into OLD_DECL
9786 by duplicate_decls. */
9788 }
9789 }
9790 else
9791 {
9795 /* In the code
9796 template <class T> class C {
9797 template <class U> friend void C1<U>::f (); // case 1
9798 friend void C2<T>::f (); // case 2
9799 };
9800 we only need to make sure CONTEXT is a complete type for
9801 case 2. To distinguish between the two cases, we note that
9802 CONTEXT of case 1 remains dependent type after tsubst while
9803 this isn't true for case 2. */
9813 {
9815 /* do_friend adds the TEMPLATE_DECL for any member friend
9816 template even if it isn't a member template, i.e.
9817 template <class T> friend A<T>::f();
9818 Look through it in that case. */
9822 /* Check to see that the declaration is really present, and,
9823 possibly obtain an improved declaration. */
9828 }
9829 }
9832 }
9834 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9835 template arguments, as for tsubst.
9837 Returns an appropriate tsubst'd friend type or error_mark_node on
9838 failure. */
9840 static tree
9842 {
9843 tree friend_type;
9844 tree tmpl;
9845 tree context;
9848 {
9851 }
9856 {
9859 else
9861 }
9863 /* Look for a class template declaration. We look for hidden names
9864 because two friend declarations of the same template are the
9865 same. For example, in:
9867 struct A {
9868 template <typename> friend class F;
9869 };
9870 template <typename> struct B {
9871 template <typename> friend class F;
9872 };
9874 both F templates are the same. */
9878 /* But, if we don't find one, it might be because we're in a
9879 situation like this:
9881 template <class T>
9882 struct S {
9883 template <class U>
9884 friend struct S;
9885 };
9887 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9888 for `S<int>', not the TEMPLATE_DECL. */
9890 {
9893 }
9896 {
9897 /* The friend template has already been declared. Just
9898 check to see that the declarations match, and install any new
9899 default parameters. We must tsubst the default parameters,
9900 of course. We only need the innermost template parameters
9901 because that is all that redeclare_class_template will look
9902 at. */
9905 {
9906 tree parms;
9907 location_t saved_input_location;
9917 }
9920 }
9921 else
9922 {
9923 /* The friend template has not already been declared. In this
9924 case, the instantiation of the template class will cause the
9925 injection of this template into the global scope. */
9930 /* The new TMPL is not an instantiation of anything, so we
9931 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
9932 the new type because that is supposed to be the corresponding
9933 template decl, i.e., TMPL. */
9940 /* Inject this template into the global scope. */
9942 }
9945 {
9948 else
9950 }
9953 }
9955 /* Returns zero if TYPE cannot be completed later due to circularity.
9956 Otherwise returns one. */
9958 static int
9960 {
9970 else
9972 }
9977 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
9978 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
9980 static tree
9983 {
9992 {
9999 clauses
10003 else
10005 }
10006 /* If the first attribute argument is an identifier, don't
10007 pass it through tsubst. Attributes like mode, format,
10008 cleanup and several target specific attributes expect it
10009 unmodified. */
10011 {
10012 tree chain
10017 }
10019 {
10020 /* An attribute pack expansion. */
10029 {
10033 }
10035 }
10036 else
10043 }
10045 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10046 unchanged or a new TREE_LIST chain. */
10048 static tree
10051 {
10056 {
10060 }
10064 {
10067 {
10070 {
10072 do
10077 }
10078 }
10080 }
10083 }
10085 /* Apply any attributes which had to be deferred until instantiation
10086 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10087 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10089 static void
10092 {
10094 tree t;
10101 {
10105 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10106 to our attributes parameter. */
10108 }
10109 else
10110 {
10112 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10113 lookup_template_class_1, and should be preserved. */
10117 }
10121 {
10125 }
10129 {
10134 {
10137 {
10141 do
10144 }
10145 else
10147 }
10150 }
10151 }
10153 /* Perform (or defer) access check for typedefs that were referenced
10154 from within the template TMPL code.
10155 This is a subroutine of instantiate_decl and instantiate_class_template.
10156 TMPL is the template to consider and TARGS is the list of arguments of
10157 that template. */
10159 static void
10161 {
10162 location_t saved_location;
10173 {
10185 /* Make access check error messages point to the location
10186 of the use of the typedef. */
10190 tf_warning_or_error);
10191 }
10193 }
10195 static tree
10197 {
10199 tree typedecl;
10200 tree pbinfo;
10201 tree base_list;
10203 tree fn_context;
10212 /* Figure out which template is being instantiated. */
10216 /* Determine what specialization of the original template to
10217 instantiate. */
10220 {
10223 }
10225 {
10226 /* This TYPE is actually an instantiation of a partial
10227 specialization. We replace the innermost set of ARGS with
10228 the arguments appropriate for substitution. For example,
10229 given:
10231 template <class T> struct S {};
10232 template <class T> struct S<T*> {};
10234 and supposing that we are instantiating S<int*>, ARGS will
10235 presently be {int*} -- but we need {int}. */
10238 }
10239 else
10240 {
10243 }
10245 /* If the template we're instantiating is incomplete, then clearly
10246 there's nothing we can do. */
10250 /* If we've recursively instantiated too many templates, stop. */
10254 /* Now we're really doing the instantiation. Mark the type as in
10255 the process of being defined. */
10258 /* We may be in the middle of deferred access check. Disable
10259 it now. */
10266 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10271 else
10272 {
10275 }
10276 /* Use #pragma pack from the template context. */
10282 /* Set the input location to the most specialized template definition.
10283 This is needed if tsubsting causes an error. */
10295 {
10298 /* Adjust visibility for template arguments. */
10300 }
10306 /* We should never instantiate a nested class before its enclosing
10307 class; we need to look up the nested class by name before we can
10308 instantiate it, and that lookup should instantiate the enclosing
10309 class. */
10315 {
10316 tree pbase_binfo;
10317 tree pushed_scope;
10320 /* We must enter the scope containing the type, as that is where
10321 the accessibility of types named in dependent bases are
10322 looked up from. */
10325 /* Substitute into each of the bases to determine the actual
10326 basetypes. */
10328 {
10329 tree base;
10335 {
10336 expanded_bases =
10343 }
10346 {
10348 /* Extract the already-expanded base class. */
10350 else
10351 /* Substitute to figure out the base class. */
10353 NULL_TREE);
10361 }
10362 }
10364 /* The list is now in reverse order; correct that. */
10369 }
10370 /* Now call xref_basetypes to set up all the base-class
10371 information. */
10379 /* Now that our base classes are set up, enter the scope of the
10380 class, so that name lookups into base classes, etc. will work
10381 correctly. This is precisely analogous to what we do in
10382 begin_class_definition when defining an ordinary non-template
10383 class, except we also need to push the enclosing classes. */
10386 /* Now members are processed in the order of declaration. */
10389 {
10393 {
10395 {
10396 /* Build new CLASSTYPE_NESTED_UTDS. */
10398 tree newtag;
10404 /* If the member is a class template, then -- even after
10405 substitution -- there may be dependent types in the
10406 template argument list for the class. We increment
10407 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10408 that function will assume that no types are dependent
10409 when outside of a template. */
10419 {
10423 /* Unfortunately, lookup_template_class sets
10424 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10425 instantiation (i.e., for the type of a member
10426 template class nested within a template class.)
10427 This behavior is required for
10428 maybe_process_partial_specialization to work
10429 correctly, but is not accurate in this case;
10430 the TAG is not an instantiation of anything.
10431 (The corresponding TEMPLATE_DECL is an
10432 instantiation, but the TYPE is not.) */
10435 /* Now, we call pushtag to put this NEWTAG into the scope of
10436 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10437 pushtag calling push_template_decl. We don't have to do
10438 this for enums because it will already have been done in
10439 tsubst_enum. */
10443 }
10444 }
10446 {
10447 /* Build new TYPE_METHODS. */
10448 tree r;
10457 /* Instantiate members marked with attribute used. */
10463 }
10466 /* A closure type for a lambda in a default argument for a
10467 member template. Ignore it; it will be instantiated with
10469 else
10470 {
10471 /* Build new TYPE_FIELDS. */
10473 {
10474 tree condition;
10477 condition =
10487 }
10489 {
10490 tree r;
10494 /* The file and line for this declaration, to
10495 assist in error message reporting. Since we
10496 called push_tinst_level above, we don't need to
10497 restore these. */
10507 {
10508 /* A capture pack became multiple fields. */
10511 }
10514 {
10518 {
10519 /* In [temp.inst]:
10521 [t]he initialization (and any associated
10522 side-effects) of a static data member does
10523 not occur unless the static data member is
10524 itself used in a way that requires the
10525 definition of the static data member to
10526 exist.
10528 Therefore, we do not substitute into the
10529 initialized for the static data member here. */
10530 finish_static_data_member_decl
10536 /* Instantiate members marked with attribute used. */
10539 }
10541 {
10542 /* Determine whether R has a valid type and can be
10543 completed later. If R is invalid, then its type
10544 is replaced by error_mark_node. */
10550 {
10551 /* If R's type couldn't be completed and
10552 it isn't a flexible array member (whose
10553 type is incomplete by definition) give
10554 an error. */
10557 }
10558 }
10560 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10561 such a thing will already have been added to the field
10562 list by tsubst_enum in finish_member_declaration in the
10563 CLASSTYPE_NESTED_UTDS case above. */
10567 {
10570 }
10571 }
10572 }
10573 }
10574 }
10575 else
10576 {
10579 {
10580 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10586 {
10587 /* template <class T> friend class C; */
10590 }
10592 {
10593 /* template <class T> friend class C::D; */
10599 }
10602 {
10603 /* This could be either
10605 friend class T::C;
10607 when dependent_type_p is false or
10609 template <class U> friend class T::C;
10611 otherwise. */
10612 /* Bump processing_template_decl in case this is something like
10613 template <class T> friend struct A<T>::B. */
10620 }
10623 {
10624 /* friend class C;
10626 where C hasn't been declared yet. Let's lookup name
10627 from namespace scope directly, bypassing any name that
10628 come from dependent base class. */
10631 /* The call to xref_tag_from_type does injection for friend
10632 classes. */
10634 friend_type =
10638 }
10640 /* friend class C<T>; */
10643 /* Otherwise it's
10645 friend class C;
10647 where C is already declared or
10649 friend class C<int>;
10651 We don't have to do anything in these cases. */
10654 /* Trick make_friend_class into realizing that the friend
10655 we're adding is a template, not an ordinary class. It's
10656 important that we use make_friend_class since it will
10657 perform some error-checking and output cross-reference
10658 information. */
10666 }
10667 else
10668 {
10669 /* Build new DECL_FRIENDLIST. */
10670 tree r;
10672 /* The file and line for this declaration, to
10673 assist in error message reporting. Since we
10674 called push_tinst_level above, we don't need to
10675 restore these. */
10679 {
10682 }
10687 {
10690 }
10691 }
10692 }
10693 }
10696 {
10697 /* Restore these before substituting into the lambda capture
10698 initializers. */
10701 }
10704 {
10707 {
10713 {
10714 /* Set function_depth to avoid garbage collection. */
10718 }
10720 /* We need to instantiate the capture list from the template
10721 after we've instantiated the closure members, but before we
10722 consider adding the conversion op. Also keep any captures
10723 that may have been added during instantiation of the op(). */
10725 tree tmpl_cap
10734 }
10735 else
10737 }
10739 /* Set the file and line number information to whatever is given for
10740 the class itself. This puts error messages involving generated
10741 implicit functions at a predictable point, and the same point
10742 that would be used for non-template classes. */
10749 /* We don't instantiate default arguments for member functions. 14.7.1:
10751 The implicit instantiation of a class template specialization causes
10752 the implicit instantiation of the declarations, but not of the
10753 definitions or default arguments, of the class member functions,
10754 member classes, static data members and member templates.... */
10756 /* Some typedefs referenced from within the template code need to be access
10757 checked at template instantiation time, i.e now. These types were
10758 added to the template at parsing time. Let's get those and perform
10759 the access checks then. */
10769 /* The vtable for a template class can be emitted in any translation
10770 unit in which the class is instantiated. When there is no key
10771 method, however, finish_struct_1 will already have added TYPE to
10772 the keyed_classes list. */
10777 }
10779 /* Wrapper for instantiate_class_template_1. */
10781 tree
10783 {
10784 tree ret;
10789 }
10791 static tree
10793 {
10794 tree r;
10800 else
10801 {
10808 }
10810 }
10812 /* Given a function parameter pack TMPL_PARM and some function parameters
10813 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10814 and set *SPEC_P to point at the next point in the list. */
10816 tree
10818 {
10819 /* Collect all of the extra "packed" parameters into an
10820 argument pack. */
10821 tree parmvec;
10822 tree parmtypevec;
10833 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10838 {
10841 }
10843 /* Build the argument packs. */
10850 }
10852 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10853 NONTYPE_ARGUMENT_PACK. */
10855 static tree
10857 {
10859 }
10861 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10862 pack expansion with no extra args, 2 if it has extra args, or 0
10863 if it is not a pack expansion. */
10865 static int
10867 {
10873 /* A decl pack is itself an expansion. */
10880 }
10883 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10885 static tree
10887 {
10894 }
10896 /* This is a subroutine of tsubst_pack_expansion.
10898 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10899 mechanism to store the (non complete list of) arguments of the
10900 substitution and return a non substituted pack expansion, in order
10901 to wait for when we have enough arguments to really perform the
10902 substitution. */
10904 static bool
10908 {
10909 /* If one pack has an expansion and another pack has a normal
10910 argument or if one pack has an empty argument and an another
10911 one hasn't then tsubst_pack_expansion cannot perform the
10912 substitution and need to fall back on the
10913 PACK_EXPANSION_EXTRA mechanism. */
10921 {
10924 parm_pack;
10926 {
10931 /* We can't substitute a pack expansion with extra args into
10932 our pattern. */
10936 else
10938 }
10942 }
10944 }
10946 /* [temp.variadic]/6 says that:
10948 The instantiation of a pack expansion [...]
10949 produces a list E1,E2, ..., En, where N is the number of elements
10950 in the pack expansion parameters.
10952 This subroutine of tsubst_pack_expansion produces one of these Ei.
10954 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
10955 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
10956 PATTERN, and each TREE_VALUE is its corresponding argument pack.
10957 INDEX is the index 'i' of the element Ei to produce. ARGS,
10958 COMPLAIN, and IN_DECL are the same parameters as for the
10959 tsubst_pack_expansion function.
10961 The function returns the resulting Ei upon successful completion,
10962 or error_mark_node.
10964 Note that this function possibly modifies the ARGS parameter, so
10965 it's the responsibility of the caller to restore it. */
10967 static tree
10969 tree parm_packs,
10971 tree args /* This parm gets
10973 tsubst_flags_t complain,
10974 tree in_decl)
10975 {
10976 tree t;
10979 /* For each parameter pack, change the substitution of the parameter
10980 pack to the ith argument in its argument pack, then expand the
10981 pattern. */
10983 {
10988 ith_elem_is_expansion |=
10991 /* Select the Ith argument from the pack. */
10994 {
10996 {
11001 }
11002 else
11004 }
11005 else
11006 {
11011 {
11013 /* Update the corresponding argument. */
11015 }
11016 else
11017 /* Re-use the ARGUMENT_PACK_SELECT. */
11019 }
11021 }
11023 /* Substitute into the PATTERN with the (possibly altered)
11024 arguments. */
11026 /* Expanding a fixed parameter pack from
11027 coerce_template_parameter_pack. */
11032 {
11035 else
11038 }
11042 else
11045 /* If the Ith argument pack element is a pack expansion, then
11046 the Ith element resulting from the substituting is going to
11047 be a pack expansion as well. */
11052 }
11054 /* When the unexpanded parameter pack in a fold expression expands to an empty
11055 sequence, the value of the expression is as follows; the program is
11056 ill-formed if the operator is not listed in this table.
11058 && true
11059 || false
11060 , void() */
11062 tree
11064 {
11068 {
11077 }
11083 }
11085 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11086 form an expression that combines the two terms using the
11087 operator of T. */
11089 static tree
11091 {
11095 // Handle compound assignment operators.
11100 {
11110 complain);
11111 }
11112 }
11114 /* Substitute ARGS into the pack of a fold expression T. */
11118 {
11120 }
11122 /* Substitute ARGS into the pack of a fold expression T. */
11126 {
11128 }
11130 /* Expand a PACK of arguments into a grouped as left fold.
11131 Given a pack containing elements A0, A1, ..., An and an
11132 operator @, this builds the expression:
11134 ((A0 @ A1) @ A2) ... @ An
11136 Note that PACK must not be empty.
11138 The operator is defined by the original fold expression T. */
11140 static tree
11142 {
11145 {
11148 }
11150 }
11152 /* Substitute into a unary left fold expression. */
11154 static tree
11156 tree in_decl)
11157 {
11162 {
11166 }
11169 else
11171 }
11173 /* Substitute into a binary left fold expression.
11175 Do ths by building a single (non-empty) vector of argumnts and
11176 building the expression from those elements. */
11178 static tree
11180 tree in_decl)
11181 {
11190 {
11195 }
11203 }
11205 /* Expand a PACK of arguments into a grouped as right fold.
11206 Given a pack containing elementns A0, A1, ..., and an
11207 operator @, this builds the expression:
11209 A0@ ... (An-2 @ (An-1 @ An))
11211 Note that PACK must not be empty.
11213 The operator is defined by the original fold expression T. */
11215 tree
11217 {
11218 // Build the expression.
11222 {
11225 }
11227 }
11229 /* Substitute into a unary right fold expression. */
11231 static tree
11233 tree in_decl)
11234 {
11239 {
11243 }
11246 else
11248 }
11250 /* Substitute into a binary right fold expression.
11252 Do ths by building a single (non-empty) vector of arguments and
11253 building the expression from those elements. */
11255 static tree
11257 tree in_decl)
11258 {
11267 {
11272 }
11281 }
11284 /* Substitute ARGS into T, which is an pack expansion
11285 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11286 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11287 (if only a partial substitution could be performed) or
11288 ERROR_MARK_NODE if there was an error. */
11289 tree
11291 tree in_decl)
11292 {
11293 tree pattern;
11297 tree result;
11305 /* Add in any args remembered from an earlier partial instantiation. */
11310 /* Determine the argument packs that will instantiate the parameter
11311 packs used in the expansion expression. While we're at it,
11312 compute the number of arguments to be expanded and make sure it
11313 is consistent. */
11316 {
11323 {
11327 else
11330 }
11332 {
11333 /* We know we have correct local_specializations if this
11334 expansion is at function scope, or if we're dealing with a
11335 local parameter in a requires expression; for the latter,
11336 tsubst_requires_expr set it up appropriately. */
11339 else
11340 /* We can't rely on local_specializations for a parameter
11341 name used later in a function declaration (such as in a
11342 late-specified return type). Even if it exists, it might
11343 have the wrong value for a recursive call. */
11347 {
11348 /* This parameter pack was used in an unevaluated context. Just
11349 make a dummy decl, since it's only used for its type. */
11352 /* Partial instantiation of the parm_pack, we can't build
11353 up an argument pack yet. */
11355 else
11357 }
11358 }
11361 else
11362 {
11368 }
11375 /* This can only happen if we forget to expand an argument
11376 pack somewhere else. Just return an error, silently. */
11377 {
11381 }
11384 {
11388 /* Don't bother trying to do a partial substitution with
11389 incomplete packs; we'll try again after deduction. */
11396 {
11402 pattern);
11403 else
11406 pattern);
11408 }
11410 /* Keep track of the parameter packs and their corresponding
11411 argument packs. */
11414 }
11415 else
11416 {
11417 /* We can't substitute for this parameter pack. We use a flag as
11418 well as the missing_level counter because function parameter
11419 packs don't have a level. */
11422 }
11423 }
11425 /* If the expansion is just T..., return the matching argument pack, unless
11426 we need to call convert_from_reference on all the elements. This is an
11427 important optimization; see c++/68422. */
11430 {
11432 /* Types need no adjustment, nor does sizeof..., and if we still have
11433 some pack expansion args we won't do anything yet. */
11438 /* Also optimize expression pack expansions if we can tell that the
11439 elements won't have reference type. */
11445 /* Otherwise use the normal path so we get convert_from_reference. */
11446 }
11448 /* We cannot expand this expansion expression, because we don't have
11449 all of the argument packs we need. */
11451 {
11452 /* We got some full packs, but we can't substitute them in until we
11453 have values for all the packs. So remember these until then. */
11458 }
11460 {
11461 /* There were no real arguments, we're just replacing a parameter
11462 pack with another version of itself. Substitute into the
11463 pattern and return a PACK_EXPANSION_*. The caller will need to
11464 deal with that. */
11468 else
11472 }
11477 {
11478 /* We're in a late-specified return type, so create our own local
11479 specializations map; the current map is either NULL or (in the
11480 case of recursive unification) might have bindings that we don't
11481 want to use or alter. */
11484 }
11486 /* For each argument in each argument pack, substitute into the
11487 pattern. */
11491 {
11493 i,
11495 in_decl);
11498 {
11501 }
11502 }
11504 /* Update ARGS to restore the substitution from parameter packs to
11505 their argument packs. */
11507 {
11513 else
11514 {
11522 /* Update the corresponding argument. */
11526 else
11528 }
11529 }
11532 {
11535 }
11537 /* If the dependent pack arguments were such that we end up with only a
11538 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11544 }
11546 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11547 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11548 parameter packs; all parms generated from a function parameter pack will
11549 have the same DECL_PARM_INDEX. */
11551 tree
11553 {
11555 tree patparm;
11558 {
11564 }
11565 else
11566 {
11571 }
11574 }
11576 /* Make an argument pack out of the TREE_VEC VEC. */
11578 static tree
11580 {
11581 tree pack;
11585 else
11586 {
11590 }
11593 }
11595 /* Return an exact copy of template args T that can be modified
11596 independently. */
11598 static tree
11600 {
11608 {
11613 }
11619 }
11621 /* Substitute ARGS into the vector or list of template arguments T. */
11623 static tree
11625 {
11637 {
11639 tree new_arg;
11644 {
11645 /* Substitute into an expansion expression. */
11649 /* Add to the expanded length adjustment the number of
11650 expanded arguments. We subtract one from this
11651 measurement, because the argument pack expression
11652 itself is already counted as 1 in
11653 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11654 the argument pack is empty. */
11656 }
11658 {
11659 /* Substitute into each of the arguments. */
11665 new_arg,
11675 else
11682 }
11683 }
11684 else
11693 }
11698 /* Make space for the expanded arguments coming from template
11699 argument packs. */
11701 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11702 arguments for a member template.
11703 In that case each TREE_VEC in ORIG_T represents a level of template
11704 arguments, and ORIG_T won't carry any non defaulted argument count.
11705 It will rather be the nested TREE_VECs that will carry one.
11706 In other words, ORIG_T carries a non defaulted argument count only
11707 if it doesn't contain any nested TREE_VEC. */
11709 {
11713 }
11715 {
11719 {
11722 /* Now expand the template argument pack "in place". */
11725 }
11726 else
11727 {
11729 out++;
11730 }
11731 }
11734 }
11736 /* Substitute ARGS into one level PARMS of template parameters. */
11738 static tree
11740 {
11747 {
11755 }
11758 }
11760 /* Return the result of substituting ARGS into the template parameters
11761 given by PARMS. If there are m levels of ARGS and m + n levels of
11762 PARMS, then the result will contain n levels of PARMS. For
11763 example, if PARMS is `template <class T> template <class U>
11764 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11765 result will be `template <int*, double, class V>'. */
11767 static tree
11769 {
11773 /* When substituting into a template, we must set
11774 PROCESSING_TEMPLATE_DECL as the template parameters may be
11775 dependent if they are based on one-another, and the dependency
11776 predicates are short-circuit outside of templates. */
11783 {
11790 }
11795 }
11797 /* Return the result of substituting ARGS into one template parameter
11798 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11799 parameter and which TREE_PURPOSE is the default argument of the
11800 template parameter. */
11802 static tree
11804 {
11825 }
11827 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11828 type T. If T is not an aggregate or enumeration type, it is
11829 handled as if by tsubst. IN_DECL is as for tsubst. If
11830 ENTERING_SCOPE is nonzero, T is the context for a template which
11831 we are presently tsubst'ing. Return the substituted value. */
11833 static tree
11835 tree args,
11836 tsubst_flags_t complain,
11837 tree in_decl,
11839 {
11844 {
11849 /* Fall through. */
11853 {
11854 tree argvec;
11855 tree context;
11856 tree r;
11860 /* In "sizeof(X<I>)" we need to evaluate "I". */
11866 /* First, determine the context for the type we are looking
11867 up. */
11870 {
11873 /* If context is a nested class inside a class template,
11874 it may still need to be instantiated (c++/33959). */
11876 }
11878 /* Then, figure out what arguments are appropriate for the
11879 type we are trying to find. For example, given:
11881 template <class T> struct S;
11882 template <class T, class U> void f(T, U) { S<U> su; }
11884 and supposing that we are instantiating f<int, double>,
11885 then our ARGS will be {int, double}, but, when looking up
11886 S we only want {double}. */
11891 else
11892 {
11896 }
11902 }
11903 else
11904 /* This is not a template type, so there's nothing to do. */
11909 }
11910 }
11912 /* Substitute into the default argument ARG (a default argument for
11913 FN), which has the indicated TYPE. */
11915 tree
11917 {
11922 /* This can happen in invalid code. */
11926 /* This default argument came from a template. Instantiate the
11927 default argument here, not in tsubst. In the case of
11928 something like:
11930 template <class T>
11931 struct S {
11932 static T t();
11933 void f(T = t());
11934 };
11936 we must be careful to do name lookup in the scope of S<T>,
11937 rather than in the current class. */
11939 /* The "this" pointer is not valid in a default argument. */
11941 {
11946 }
11949 /* The default argument expression may cause implicitly defined
11950 member functions to be synthesized, which will result in garbage
11951 collection. We must treat this situation as if we were within
11952 the body of function so as to avoid collecting live data on the
11953 stack. */
11961 /* Restore the "this" pointer. */
11963 {
11966 }
11973 /* Make sure the default argument is reasonable. */
11979 }
11981 /* Substitute into all the default arguments for FN. */
11983 static void
11985 {
11986 tree arg;
11987 tree tmpl_args;
11991 /* If this function is not yet instantiated, we certainly don't need
11992 its default arguments. */
11995 /* Don't do this again for clones. */
12000 arg;
12006 complain);
12007 }
12009 /* Substitute the ARGS into the T, which is a _DECL. Return the
12010 result of the substitution. Issue error and warning messages under
12011 control of COMPLAIN. */
12013 static tree
12015 {
12016 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12017 location_t saved_loc;
12022 /* Set the filename and linenumber to improve error-reporting. */
12027 {
12029 {
12030 /* We can get here when processing a member function template,
12031 member class template, or template template parameter. */
12033 tree spec;
12034 tree tmpl_args;
12035 tree full_args;
12038 {
12039 /* Template template parameter is treated here. */
12043 /* If we get a real template back, return it. This can happen in
12044 the context of most_specialized_partial_spec. */
12047 else
12048 /* The new TEMPLATE_DECL was built in
12049 reduce_template_parm_level. */
12052 }
12054 /* We might already have an instance of this template.
12055 The ARGS are for the surrounding class type, so the
12056 full args contain the tsubst'd args for the context,
12057 plus the innermost args from the template decl. */
12061 /* Because this is a template, the arguments will still be
12062 dependent, even after substitution. If
12063 PROCESSING_TEMPLATE_DECL is not set, the dependency
12064 predicates will short-circuit. */
12072 /* If this is a default template template argument,
12073 tsubst might not have changed anything. */
12080 {
12083 }
12085 /* Make a new template decl. It will be similar to the
12086 original, but will record the current template arguments.
12087 We also create a new function declaration, which is just
12088 like the old one, but points to this new template, rather
12089 than the old one. */
12094 // Build new template info linking to the original template decl.
12099 {
12100 tree new_type;
12108 /* For a partial specialization, we need to keep pointing to
12109 the primary template. */
12115 }
12116 else
12117 {
12118 tree new_decl;
12130 }
12136 /* The template parameters for this new template are all the
12137 template parameters for the old template, except the
12138 outermost level of parameters. */
12141 complain);
12147 /* Record this non-type partial instantiation. */
12151 }
12155 {
12156 tree ctx;
12159 tree gen_tmpl;
12160 tree type;
12165 /* Nobody should be tsubst'ing into non-template functions. */
12169 {
12170 tree spec;
12172 /* If T is not dependent, just return it. */
12176 /* Calculate the most general template of which R is a
12177 specialization, and the complete set of arguments used to
12178 specialize R. */
12181 (DECL_TEMPLATE_RESULT
12187 /* Check to see if we already have this specialization. */
12192 {
12195 }
12197 /* We can see more levels of arguments than parameters if
12198 there was a specialization of a member template, like
12199 this:
12201 template <class T> struct S { template <class U> void f(); }
12202 template <> template <class U> void S<int>::f(U);
12204 Here, we'll be substituting into the specialization,
12205 because that's where we can find the code we actually
12206 want to generate, but we'll have enough arguments for
12207 the most general template.
12209 We also deal with the peculiar case:
12211 template <class T> struct S {
12212 template <class U> friend void f();
12213 };
12214 template <class U> void f() {}
12215 template S<int>;
12216 template void f<double>();
12218 Here, the ARGS for the instantiation of will be {int,
12219 double}. But, we only need as many ARGS as there are
12220 levels of template parameters in CODE_PATTERN. We are
12221 careful not to get fooled into reducing the ARGS in
12222 situations like:
12224 template <class T> struct S { template <class U> void f(U); }
12225 template <class T> template <> void S<T>::f(int) {}
12227 which we can spot because the pattern will be a
12228 specialization in this case. */
12230 parms_depth =
12235 }
12236 else
12237 {
12238 /* This special case arises when we have something like this:
12240 template <class T> struct S {
12241 friend void f<int>(int, double);
12242 };
12244 Here, the DECL_TI_TEMPLATE for the friend declaration
12245 will be an IDENTIFIER_NODE. We are being called from
12246 tsubst_friend_function, and we want only to create a
12247 new decl (R) with appropriate types so that we can call
12248 determine_specialization. */
12250 }
12253 {
12256 else
12260 }
12261 else
12262 {
12265 }
12270 /* If we hit excessive deduction depth, the type is bogus even if
12271 it isn't error_mark_node, so don't build a decl. */
12275 /* We do NOT check for matching decls pushed separately at this
12276 point, as they may not represent instantiations of this
12277 template, and in any case are considered separate under the
12278 discrete model. */
12282 /* Clear out the mangled name and RTL for the instantiation. */
12285 /* Leave DECL_INITIAL set on deleted instantiations. */
12290 /* OpenMP UDRs have the only argument a reference to the declared
12291 type. We want to diagnose if the declared type is a reference,
12292 which is invalid, but as references to references are usually
12293 quietly merged, diagnose it here. */
12295 {
12296 tree argtype
12301 "reference type %qT in "
12305 argtype);
12306 }
12309 /* Type-conversion operator. Reconstruct the name, in
12310 case it's the name of one of the template's parameters. */
12320 /* If this is an instantiation of a function with internal
12321 linkage, we already know what object file linkage will be
12322 assigned to the instantiation. */
12331 /* We'll re-clone as appropriate in instantiate_template. */
12334 /* If we aren't complaining now, return on error before we register
12335 the specialization so that we'll complain eventually. */
12341 /* When instantiating a constrained member, substitute
12342 into the constraints to create a new constraint. */
12345 {
12348 }
12350 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12351 this in the special friend case mentioned above where
12352 GEN_TMPL is NULL. */
12354 {
12359 tree new_r
12362 /* We instantiated this while substituting into
12363 the type earlier (template/friend54.C). */
12366 /* We're not supposed to instantiate default arguments
12367 until they are called, for a template. But, for a
12368 declaration like:
12370 template <class T> void f ()
12371 { extern void g(int i = T()); }
12373 we should do the substitution when the template is
12374 instantiated. We handle the member function case in
12375 instantiate_class_template since the default arguments
12376 might refer to other members of the class. */
12381 }
12382 else
12385 /* Copy the list of befriending classes. */
12389 {
12393 in_decl);
12394 }
12397 {
12401 /* If this is an instantiation of a member template, clone it.
12402 If it isn't, that'll be handled by
12403 clone_constructors_and_destructors. */
12406 }
12417 /* Possibly limit visibility based on template args. */
12420 {
12424 }
12432 }
12436 {
12444 {
12445 /* If there is a local specialization that isn't a
12446 parameter pack, it means that we're doing a "simple"
12447 substitution from inside tsubst_pack_expansion. Just
12448 return the local specialization (which will be a single
12449 parm). */
12456 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12457 the parameters in this function parameter pack. */
12461 {
12464 /* Zero-length parameter packs are boring. Just substitute
12465 into the chain. */
12469 }
12470 else
12471 {
12472 /* All we did was update the type. Make a note of that. */
12475 }
12476 }
12478 /* Loop through all of the parameters we'll build. When T is
12479 a function parameter pack, LEN is the number of expanded
12480 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12483 {
12490 /* We're on the Ith parameter of the function parameter
12491 pack. */
12492 {
12493 /* Get the Ith type. */
12496 /* Rename the parameter to include the index. */
12499 }
12501 /* We're dealing with a normal parameter. */
12509 {
12512 else
12515 }
12525 /* Keep track of the first new parameter we
12526 generate. That's what will be returned to the
12527 caller. */
12531 /* Build a proper chain of parameters when substituting
12532 into a function parameter pack. */
12535 }
12537 /* If cp_unevaluated_operand is set, we're just looking for a
12538 single dummy parameter, so don't keep going. */
12543 /* FIRST_R contains the start of the chain we've built. */
12545 }
12549 {
12556 {
12557 /* This field is a lambda capture pack. Return a TREE_VEC of
12558 the expanded fields to instantiate_class_template_1 and
12559 store them in the specializations hash table as a
12560 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12564 {
12567 }
12568 else
12569 {
12570 /* All we did was update the type. Make a note of that. */
12573 }
12574 }
12577 {
12580 {
12584 }
12594 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12595 non-bit-fields DECL_INITIAL is a non-static data member
12596 initializer, which gets deferred instantiation. */
12602 {
12603 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12604 NSDMI in perform_member_init. Still set DECL_INITIAL
12605 so that we know there is one. */
12610 }
12611 /* We don't have to set DECL_CONTEXT here; it is set by
12612 finish_member_declaration. */
12620 }
12623 {
12631 }
12632 }
12636 /* We reach here only for member using decls. We also need to check
12637 uses_template_parms because DECL_DEPENDENT_P is not set for a
12638 using-declaration that designates a member of the current
12639 instantiation (c++/53549). */
12642 {
12646 {
12651 {
12655 {
12658 }
12659 else
12660 {
12663 }
12665 }
12666 }
12667 else
12668 {
12674 else
12675 {
12678 }
12679 }
12680 }
12681 else
12682 {
12685 }
12690 {
12693 tree spec;
12695 tree ctx;
12704 {
12705 /* If this is the canonical decl, we don't have to
12706 mess with instantiations, and often we can't (for
12707 typename, template type parms and such). Note that
12708 TYPE_NAME is not correct for the above test if
12709 we've copied the type for a typedef. */
12715 }
12717 /* Check to see if we already have the specialization we
12718 need. */
12721 {
12722 /* T is a static data member or namespace-scope entity.
12723 We have to substitute into namespace-scope variables
12724 (not just variable templates) because of cases like:
12726 template <class T> void f() { extern T t; }
12728 where the entity referenced is not known until
12729 instantiation time. */
12733 {
12735 complain,
12737 /* If CTX is unchanged, then T is in fact the
12738 specialization we want. That situation occurs when
12739 referencing a static data member within in its own
12740 class. We can use pointer equality, rather than
12741 same_type_p, because DECL_CONTEXT is always
12742 canonical... */
12744 /* ... unless T is a member template; in which
12745 case our caller can be willing to create a
12746 specialization of that template represented
12747 by T. */
12751 }
12754 {
12759 argvec = (coerce_innermost_template_parms
12767 }
12768 }
12769 else
12770 {
12771 /* A local variable. */
12773 /* Subsequent calls to pushdecl will fill this in. */
12775 /* Unless this is a reference to a static variable from an
12776 enclosing function, in which case we need to fill it in now. */
12778 {
12782 }
12784 }
12785 /* If we already have the specialization we need, there is
12786 nothing more to do. */
12788 {
12791 }
12793 /* Create a new node for the specialization we need. */
12796 {
12799 else
12806 }
12808 {
12809 /* Even if the original location is out of scope, the
12810 newly substituted one is not. */
12817 {
12818 /* It may seem that this case cannot occur, since:
12820 typedef void f();
12821 void g() { f x; }
12823 declares a function, not a variable. However:
12825 typedef void f();
12826 template <typename T> void g() { T t; }
12827 template void g<f>();
12829 is an attempt to declare a variable with function
12830 type. */
12832 /* R is not yet sufficiently initialized, so we
12833 just use its name. */
12836 }
12838 /* Wait until cp_finish_decl to set this again, to handle
12839 circular dependency (template/instantiate6.C). */
12844 {
12849 {
12852 }
12854 }
12858 }
12864 /* Clear out the mangled name and RTL for the instantiation. */
12868 /* The initializer must not be expanded until it is required;
12869 see [temp.inst]. */
12877 {
12878 /* Possibly limit visibility based on template args. */
12881 {
12885 }
12887 }
12890 {
12891 /* A static data member declaration is always marked
12892 external when it is declared in-class, even if an
12893 initializer is present. We mimic the non-template
12894 processing here. */
12902 }
12903 else
12904 {
12909 }
12917 /* Preserve a typedef that names a type. */
12919 {
12923 /* An alias template specialization can be dependent
12924 even if its underlying type is not. */
12926 }
12929 }
12934 }
12935 #undef RETURN
12937 out:
12938 /* Restore the file and line information. */
12942 }
12944 /* Substitute into the ARG_TYPES of a function type.
12945 If END is a TREE_CHAIN, leave it and any following types
12946 un-substituted. */
12948 static tree
12950 tree args,
12951 tree end,
12952 tsubst_flags_t complain,
12953 tree in_decl)
12954 {
12955 tree remaining_arg_types;
12959 tree default_arg;
12970 {
12971 /* For a pack expansion, perform substitution on the
12972 entire expression. Later on, we'll handle the arguments
12973 one-by-one. */
12978 /* So that we'll spin through the parameters, one by one. */
12980 else
12981 {
12982 /* We only partially substituted into the parameter
12983 pack. Our type is TYPE_PACK_EXPANSION. */
12986 }
12987 }
13000 {
13002 {
13006 }
13008 }
13009 /* DR 657. */
13013 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13014 top-level qualifiers as required. */
13017 /* We do not substitute into default arguments here. The standard
13018 mandates that they be instantiated only when needed, which is
13019 done in build_over_call. */
13023 {
13024 /* We've instantiated a template before its default arguments
13025 have been parsed. This can happen for a nested template
13026 class, and is not an error unless we require the default
13027 argument in a call of this function. */
13028 remaining_arg_types =
13031 }
13032 else
13033 remaining_arg_types =
13035 }
13038 }
13040 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13041 *not* handle the exception-specification for FNTYPE, because the
13042 initial substitution of explicitly provided template parameters
13043 during argument deduction forbids substitution into the
13044 exception-specification:
13046 [temp.deduct]
13048 All references in the function type of the function template to the
13049 corresponding template parameters are replaced by the specified tem-
13050 plate argument values. If a substitution in a template parameter or
13051 in the function type of the function template results in an invalid
13052 type, type deduction fails. [Note: The equivalent substitution in
13053 exception specifications is done only when the function is instanti-
13054 ated, at which point a program is ill-formed if the substitution
13055 results in an invalid type.] */
13057 static tree
13059 tree args,
13060 tsubst_flags_t complain,
13061 tree in_decl)
13062 {
13063 tree return_type;
13065 tree fntype;
13067 /* The TYPE_CONTEXT is not used for function/method types. */
13070 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13071 failure. */
13075 {
13076 /* Substitute the argument types. */
13088 {
13089 /* DR 1207: 'this' is in scope in the trailing return type. */
13091 }
13093 /* Substitute the return type. */
13097 {
13100 }
13101 }
13102 else
13103 /* Substitute the return type. */
13108 /* DR 486 clarifies that creation of a function type with an
13109 invalid return type is a deduction failure. */
13112 {
13114 {
13117 else
13119 }
13121 }
13122 /* And DR 657. */
13127 {
13128 /* Substitute the argument types. */
13133 }
13135 /* Construct a new type node and return it. */
13137 {
13142 }
13143 else
13144 {
13146 /* Don't pick up extra function qualifiers from the basetype. */
13149 {
13150 /* [temp.deduct]
13152 Type deduction may fail for any of the following
13153 reasons:
13155 -- Attempting to create "pointer to member of T" when T
13156 is not a class type. */
13159 r);
13161 }
13166 }
13173 }
13175 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13176 ARGS into that specification, and return the substituted
13177 specification. If there is no specification, return NULL_TREE. */
13179 static tree
13181 tree args,
13182 tsubst_flags_t complain,
13183 tree in_decl,
13185 {
13186 tree specs;
13187 tree new_specs;
13192 {
13193 /* A noexcept-specifier. */
13198 {
13199 /* Defer instantiation of noexcept-specifiers to avoid
13200 excessive instantiations (c++/49107). */
13203 {
13204 /* We already partially instantiated this member template,
13205 so combine the new args with the old. */
13210 }
13211 else
13212 {
13215 }
13216 }
13217 else
13218 new_specs = tsubst_copy_and_build
13222 }
13224 {
13227 else
13229 {
13230 tree spec;
13235 {
13236 /* Expand the pack expansion type. */
13239 in_decl);
13245 else
13246 {
13247 /* We're substituting into a member template, so
13248 we got a TYPE_PACK_EXPANSION back. Add that
13249 expansion and move on. */
13253 expanded_specs,
13254 complain);
13257 }
13258 }
13261 {
13264 else
13269 complain);
13270 }
13273 }
13274 }
13276 }
13278 /* Take the tree structure T and replace template parameters used
13279 therein with the argument vector ARGS. IN_DECL is an associated
13280 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13281 Issue error and warning messages under control of COMPLAIN. Note
13282 that we must be relatively non-tolerant of extensions here, in
13283 order to preserve conformance; if we allow substitutions that
13284 should not be allowed, we may allow argument deductions that should
13285 not succeed, and therefore report ambiguous overload situations
13286 where there are none. In theory, we could allow the substitution,
13287 but indicate that it should have failed, and allow our caller to
13288 make sure that the right thing happens, but we don't try to do this
13289 yet.
13291 This function is used for dealing with types, decls and the like;
13292 for expressions, use tsubst_expr or tsubst_copy. */
13294 tree
13296 {
13319 else
13324 /* Reuse typedefs. We need to do this to handle dependent attributes,
13325 such as attribute aligned. */
13328 {
13332 {
13333 /* DECL represents an alias template and we want to
13334 instantiate it. */
13338 }
13342 {
13346 }
13351 else
13352 /* The typedef is from a non-template context. */
13356 {
13358 r = cp_build_qualified_type_real
13362 }
13363 else
13364 {
13365 /* We don't have an instantiation yet, so drop the typedef. */
13370 }
13371 }
13387 {
13413 {
13419 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13420 needed. */
13426 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13427 with TREE_SIDE_EFFECTS that indicates this is not an integral
13428 constant expression. */
13431 {
13434 }
13437 }
13443 {
13449 /* Early in template argument deduction substitution, we don't
13450 want to reduce the level of 'auto', or it will be confused
13451 with a normal template parm in subsequent deduction. */
13463 {
13467 {
13468 /* See through ARGUMENT_PACK_SELECT arguments. */
13470 /* If the selected argument is an expansion E, that most
13471 likely means we were called from
13472 gen_elem_of_pack_expansion_instantiation during the
13473 substituting of pack an argument pack (which Ith
13474 element is a pack expansion, where I is
13475 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13476 In this case, the Ith element resulting from this
13477 substituting is going to be a pack expansion, which
13478 pattern is the pattern of E. Let's return the
13479 pattern of E, and
13480 gen_elem_of_pack_expansion_instantiation will
13481 build the resulting pack expansion from it. */
13483 {
13484 /* Make sure we aren't throwing away arg info. */
13487 }
13488 }
13489 }
13494 {
13496 /* If ARG is an argument pack, we don't actually want to
13497 perform a substitution here, because substitutions
13498 for argument packs are only done
13499 element-by-element. We can get to this point when
13500 substituting the type of a non-type template
13501 parameter pack, when that type actually contains
13502 template parameter packs from an outer template, e.g.,
13504 template<typename... Types> struct A {
13505 template<Types... Values> struct B { };
13506 }; */
13510 {
13516 return cp_build_qualified_type_real
13518 }
13520 {
13521 /* We are processing a type constructed from a
13522 template template parameter. */
13533 /* Consider this code:
13535 template <template <class> class Template>
13536 struct Internal {
13537 template <class Arg> using Bind = Template<Arg>;
13538 };
13540 template <template <class> class Template, class Arg>
13541 using Instantiate = Template<Arg>; //#0
13543 template <template <class> class Template,
13544 class Argument>
13545 using Bind =
13546 Instantiate<Internal<Template>::template Bind,
13547 Argument>; //#1
13549 When #1 is parsed, the
13550 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13551 parameter `Template' in #0 matches the
13552 UNBOUND_CLASS_TEMPLATE representing the argument
13553 `Internal<Template>::template Bind'; We then want
13554 to assemble the type `Bind<Argument>' that can't
13555 be fully created right now, because
13556 `Internal<Template>' not being complete, the Bind
13557 template cannot be looked up in that context. So
13558 we need to "store" `Bind<Argument>' for later
13559 when the context of Bind becomes complete. Let's
13560 store that in a TYPENAME_TYPE. */
13564 argvec),
13565 typename_type,
13566 complain);
13568 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13569 are resolving nested-types in the signature of a
13570 member function templates. Otherwise ARG is a
13571 TEMPLATE_DECL and is the real template to be
13572 instantiated. */
13580 complain);
13581 return cp_build_qualified_type_real
13583 }
13586 else
13587 /* TEMPLATE_PARM_INDEX. */
13589 }
13592 /* This can happen during the attempted tsubst'ing in
13593 unify. This means that we don't yet have any information
13594 about the template parameter in question. */
13597 /* If we get here, we must have been looking at a parm for a
13598 more deeply nested template. Make a new version of this
13599 template parameter, but with a lower level. */
13601 {
13606 {
13608 r = cp_build_qualified_type_real
13612 }
13619 /* Break infinite recursion when substituting the constraints
13621 else
13622 {
13633 {
13634 /* Propagate constraints on placeholders. */
13639 {
13643 }
13644 }
13647 /* We have reduced the level of the template
13648 template parameter, but not the levels of its
13649 template parameters, so canonical_type_parameter
13650 will not be able to find the canonical template
13651 template parameter for this level. Thus, we
13652 require structural equality checking to compare
13653 TEMPLATE_TEMPLATE_PARMs. */
13657 else
13661 {
13663 /* We might need to substitute into the types of non-type
13664 template parameters. */
13676 }
13677 }
13686 }
13689 }
13692 {
13700 {
13704 }
13707 {
13711 }
13714 {
13718 }
13724 }
13727 /* We should never be tsubsting a binfo. */
13731 /* A vector of template arguments. */
13737 {
13741 /* [temp.deduct]
13743 Type deduction may fail for any of the following
13744 reasons:
13746 -- Attempting to create a pointer to reference type.
13747 -- Attempting to create a reference to a reference type or
13748 a reference to void.
13750 Core issue 106 says that creating a reference to a reference
13751 during instantiation is no longer a cause for failure. We
13752 only enforce this check in strict C++98 mode. */
13756 {
13759 /* We keep track of the last time we issued this error
13760 message to avoid spewing a ton of messages during a
13761 single bad template instantiation. */
13764 {
13769 else
13772 }
13775 }
13779 {
13781 {
13784 type);
13785 else
13787 type);
13788 }
13790 }
13792 {
13796 }
13798 /* In C++0x, during template argument substitution, when there is an
13799 attempt to create a reference to a reference type, reference
13800 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13802 "If a template-argument for a template-parameter T names a type
13803 that is a reference to a type A, an attempt to create the type
13804 'lvalue reference to cv T' creates the type 'lvalue reference to
13805 A,' while an attempt to create the type type rvalue reference to
13806 cv T' creates the type T"
13807 */
13808 r = cp_build_reference_type
13811 else
13816 /* Will this ever be needed for TYPE_..._TO values? */
13820 }
13822 {
13825 {
13826 /* [temp.deduct]
13828 Type deduction may fail for any of the following
13829 reasons:
13831 -- Attempting to create "pointer to member of T" when T
13832 is not a class type. */
13836 }
13838 {
13842 }
13844 {
13848 }
13851 {
13852 /* The type of the implicit object parameter gets its
13853 cv-qualifiers from the FUNCTION_TYPE. */
13854 tree memptr;
13855 tree method_type
13860 complain);
13861 }
13862 else
13865 complain);
13866 }
13869 {
13870 tree fntype;
13871 tree specs;
13876 /* Substitute the exception specification. */
13884 }
13886 {
13891 /* As an optimization, we avoid regenerating the array type if
13892 it will obviously be the same as T. */
13896 /* These checks should match the ones in create_array_type_for_decl.
13898 [temp.deduct]
13900 The deduction may fail for any of the following reasons:
13902 -- Attempting to create an array with an element type that
13903 is void, a function type, or a reference type, or [DR337]
13904 an abstract class type. */
13910 {
13914 }
13922 {
13925 }
13928 }
13931 {
13943 {
13947 }
13949 {
13950 /* Normally, make_typename_type does not require that the CTX
13951 have complete type in order to allow things like:
13953 template <class T> struct S { typename S<T>::X Y; };
13955 But, such constructs have already been resolved by this
13956 point, so here CTX really should have complete type, unless
13957 it's a partial instantiation. */
13960 {
13964 }
13965 }
13972 {
13975 }
13978 {
13980 {
13984 else
13986 }
13988 {
13992 else
13994 }
13995 }
13997 return cp_build_qualified_type_real
13999 }
14002 {
14014 }
14017 {
14018 tree type;
14034 complain);
14035 }
14038 {
14039 tree type;
14050 {
14052 {
14056 }
14059 }
14070 else
14071 {
14075 /* In a template ~id could be either a complement expression
14076 or an unqualified-id naming a destructor; if instantiating
14077 it produces an expression, it's not an id-expression or
14078 member access. */
14081 }
14086 }
14089 {
14093 }
14097 {
14098 tree r;
14101 {
14103 /* Set the already-substituted type. */
14105 }
14106 else
14114 }
14129 /* We should use one of the expression tsubsts for these codes. */
14135 }
14136 }
14138 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
14139 type of the expression on the left-hand side of the "." or "->"
14140 operator. */
14142 static tree
14145 {
14146 tree name;
14147 tree qualifying_scope;
14148 tree fns;
14149 tree optype;
14154 /* A baselink indicates a function from a base class. Both the
14155 BASELINK_ACCESS_BINFO and the base class referenced may
14156 indicate bases of the template class, rather than the
14157 instantiated class. In addition, lookups that were not
14158 ambiguous before may be ambiguous now. Therefore, we perform
14159 the lookup again. */
14166 {
14173 }
14179 {
14181 {
14185 }
14187 }
14189 /* If lookup found a single function, mark it as used at this
14190 point. (If it lookup found multiple functions the one selected
14191 later by overload resolution will be marked as used at that
14192 point.) */
14199 /* Add back the template arguments, if present. */
14203 unknown_type_node,
14205 template_args);
14206 /* Update the conversion operator type. */
14214 {
14216 qualifying_scope,
14217 object_type);
14219 /* We need to call adjust_result_of_qualified_name_lookup in case the
14220 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14221 so that we still get virtual function binding. */
14223 }
14225 }
14227 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14228 true if the qualified-id will be a postfix-expression in-and-of
14229 itself; false if more of the postfix-expression follows the
14230 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14231 of "&". */
14233 static tree
14237 {
14238 tree expr;
14239 tree scope;
14240 tree name;
14242 tree template_args;
14247 /* Figure out what name to look up. */
14250 {
14260 }
14261 else
14262 {
14265 }
14267 /* Substitute into the qualifying scope. When there are no ARGS, we
14268 are just trying to simplify a non-dependent expression. In that
14269 case the qualifying scope may be dependent, and, in any case,
14270 substituting will not help. */
14273 {
14276 }
14277 else
14281 {
14288 }
14291 {
14293 {
14294 /* A BIT_NOT_EXPR is used to represent a destructor. */
14296 {
14300 }
14301 else
14304 }
14305 else
14309 {
14311 {
14315 }
14317 }
14318 }
14321 {
14323 scope);
14324 /* Remember that there was a reference to this entity. */
14327 }
14330 {
14336 }
14339 {
14342 complain);
14343 else
14345 }
14351 {
14352 expr = (adjust_result_of_qualified_name_lookup
14354 expr = (finish_qualified_id_expr
14358 }
14360 /* Expressions do not generally have reference type. */
14362 /* However, if we're about to form a pointer-to-member, we just
14363 want the referenced member referenced. */
14371 }
14373 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14374 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14375 for tsubst. */
14377 static tree
14380 {
14387 {
14388 /* If we had an initializer but it
14389 instantiated to nothing,
14390 value-initialize the object. This will
14391 only occur when the initializer was a
14392 pack expansion where the parameter packs
14393 used in that expansion were of length
14394 zero. */
14396 complain);
14399 }
14402 }
14404 /* Like tsubst, but deals with expressions. This function just replaces
14405 template parms; to finish processing the resultant expression, use
14406 tsubst_copy_and_build or tsubst_expr. */
14408 static tree
14410 {
14412 tree r;
14420 {
14425 {
14426 /* We get here for a use of 'this' in an NSDMI as part of a
14427 constructor call or as part of an aggregate initialization. */
14429 && ((current_function_decl
14431 || (current_class_ref
14435 /* This can happen for a parameter name used later in a function
14436 declaration (such as in a late-specified return type). Just
14437 make a dummy decl, since it's only used for its type. */
14440 /* Give it the template pattern as its context; its true context
14441 hasn't been instantiated yet and this is good enough for
14442 mangling. */
14444 }
14453 {
14454 tree enum_type;
14455 tree v;
14459 /* There is no need to substitute into namespace-scope
14460 enumerators. */
14463 /* If ARGS is NULL, then T is known to be non-dependent. */
14467 /* Unfortunately, we cannot just call lookup_name here.
14468 Consider:
14470 template <int I> int f() {
14471 enum E { a = I };
14472 struct S { void g() { E e = a; } };
14473 };
14475 When we instantiate f<7>::S::g(), say, lookup_name is not
14476 clever enough to find f<7>::a. */
14477 enum_type
14487 /* We didn't find the name. That should never happen; if
14488 name-lookup found it during preliminary parsing, we
14489 should find it again here during instantiation. */
14491 }
14496 {
14497 /* Check for a local specialization set up by
14498 tsubst_pack_expansion. */
14500 {
14504 }
14506 /* When retrieving a capture pack from a generic lambda, remove the
14507 lambda call op's own template argument list from ARGS. Only the
14508 template arguments active for the closure type should be used to
14509 retrieve the pack specialization. */
14515 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14516 tsubst_decl put in the hash table. */
14518 }
14521 {
14522 tree ctx;
14527 {
14530 {
14534 }
14536 }
14537 }
14547 {
14550 {
14551 /* First try name lookup to find the instantiation. */
14554 {
14555 /* Make sure that the one we found is the one we want. */
14561 }
14565 else
14566 {
14567 /* This can happen for a variable used in a
14568 late-specified return type of a local lambda, or for a
14569 local static or constant. Building a new VAR_DECL
14570 should be OK in all those cases. */
14573 {
14574 /* We can't call cp_finish_decl, so handle the
14575 initializer by hand. */
14586 }
14593 }
14594 /* Remember this for subsequent uses. */
14597 }
14598 }
14599 else
14609 /* An OVERLOAD will always be a non-dependent overload set; an
14610 overload set from function scope will just be represented with an
14611 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14627 {
14628 /* Template template argument like the following example need
14629 special treatment:
14631 template <template <class> class TT> struct C {};
14632 template <class T> struct D {
14633 template <class U> struct E {};
14634 C<E> c; // #1
14635 };
14636 D<int> d; // #2
14638 We are processing the template argument `E' in #1 for
14639 the template instantiation #2. Originally, `E' is a
14640 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14641 have to substitute this with one having context `D<int>'. */
14645 {
14646 /* When rewriting a constructor into a deduction guide, a
14647 non-dependent name can become dependent, so memtmpl<args>
14648 becomes context::template memtmpl<args>. */
14652 }
14654 }
14655 else
14656 /* Ordinary template template argument. */
14667 {
14671 }
14676 {
14685 /* We only want to compute the number of arguments. */
14688 else
14695 {
14697 /* Set TREE_USED for the benefit of -Wunused. */
14701 }
14709 {
14714 else
14720 else
14723 }
14724 else
14726 }
14728 {
14736 }
14737 /* Fall through */
14753 {
14757 }
14760 {
14761 tree object;
14762 tree name;
14767 {
14771 }
14774 {
14784 }
14789 in_decl);
14790 else
14793 }
14831 {
14835 }
14838 {
14843 }
14846 {
14850 }
14853 {
14861 }
14867 {
14874 }
14877 {
14884 }
14887 {
14894 }
14897 {
14898 /* Substituted template arguments */
14907 }
14910 {
14930 }
14955 /* Fall through. */
14958 {
14961 }
14962 else
14966 /* This is handled by tsubst_copy_and_build. */
14970 {
14974 }
14977 /* We shouldn't have built any of these during initial template
14978 generation. Instead, they should be built during instantiation
14979 in response to the saved STMT_IS_FULL_EXPR_P setting. */
14983 {
14993 }
15011 {
15012 /* Instantiate any typedefs in the type. */
15017 }
15020 /* These can sometimes show up in a partial instantiation, but never
15021 involve template parms. */
15035 /* We shouldn't get here, but keep going if !flag_checking. */
15039 }
15040 }
15042 /* Helper function for tsubst_omp_clauses, used for instantiation of
15043 OMP_CLAUSE_DECL of clauses. */
15045 static tree
15047 tree in_decl)
15048 {
15052 /* Handle an OpenMP array section represented as a TREE_LIST (or
15053 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15054 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15055 TREE_LIST. We can handle it exactly the same as an array section
15056 (purpose, value, and a chain), even though the nomenclature
15057 (low_bound, length, etc) is different. */
15059 {
15060 tree low_bound
15066 in_decl);
15075 }
15078 /* Undo convert_from_reference tsubst_expr could have called. */
15084 }
15086 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15088 static tree
15091 {
15096 {
15102 {
15105 {
15111 }
15112 /* FALLTHRU */
15127 in_decl);
15159 {
15162 {
15169 }
15170 else
15172 }
15175 in_decl);
15181 in_decl);
15189 in_decl);
15191 {
15194 }
15199 else
15202 in_decl,
15226 }
15229 {
15239 /* tsubst_expr on SCOPE_REF results in returning
15240 finish_non_static_data_member result. Undo that here. */
15244 {
15249 {
15253 CASE_CONVERT:
15262 /* FALLTHRU */
15266 }
15267 }
15273 {
15276 {
15280 }
15281 }
15285 }
15286 }
15290 {
15295 {
15298 }
15299 }
15301 }
15303 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15305 static tree
15307 tree in_decl)
15308 {
15309 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15329 {
15332 else
15333 {
15337 }
15338 }
15343 #undef RECUR
15344 }
15346 /* Used to temporarily communicate the list of #pragma omp parallel
15347 clauses to #pragma omp for instantiation if they are combined
15348 together. */
15352 /* Substitute one OMP_FOR iterator. */
15354 static void
15359 {
15360 #define RECUR(NODE) \
15361 tsubst_expr ((NODE), args, complain, in_decl, \
15362 integral_constant_expression_p)
15369 {
15372 }
15378 {
15379 /* We need to jump through some hoops to handle declarations in the
15380 init-statement, since we might need to handle auto deduction,
15381 but we need to keep control of initialization. */
15385 }
15386 else
15387 {
15389 {
15392 {
15396 {
15400 CASE_CONVERT:
15408 {
15411 }
15412 /* FALLTHRU */
15416 }
15417 }
15418 }
15419 else
15421 }
15432 {
15434 {
15435 /* Declare the variable, but don't let that initialize it. */
15440 }
15445 {
15450 }
15451 else
15458 }
15461 {
15462 /* Declare and initialize the variable. */
15465 }
15467 {
15471 {
15473 {
15479 {
15482 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15487 }
15490 {
15492 decl);
15494 }
15497 {
15499 decl);
15501 }
15502 else
15504 }
15507 }
15509 {
15514 {
15517 }
15518 }
15519 }
15522 {
15526 }
15527 else
15531 {
15542 {
15550 }
15551 else
15557 {
15563 }
15567 {
15575 }
15576 else
15582 }
15588 #undef RECUR
15589 }
15591 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15592 of OMP_TARGET's body. */
15594 static tree
15596 {
15599 {
15608 }
15610 }
15612 /* Helper function for tsubst_expr. For decomposition declaration
15613 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15614 also the corresponding decls representing the identifiers
15615 of the decomposition declaration. Return DECL if successful
15616 or error_mark_node otherwise, set *FIRST to the first decl
15617 in the list chained through DECL_CHAIN and *CNT to the number
15618 of such decls. */
15620 static tree
15624 {
15629 decl2
15634 {
15636 {
15639 }
15655 {
15658 }
15659 else
15661 }
15664 }
15666 /* Like tsubst_copy for expressions, etc. but also does semantic
15667 processing. */
15669 tree
15672 {
15673 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15674 #define RECUR(NODE) \
15675 tsubst_expr ((NODE), args, complain, in_decl, \
15676 integral_constant_expression_p)
15679 tree r;
15680 location_t loc;
15692 {
15694 {
15695 tree_stmt_iterator i;
15699 }
15714 else
15723 {
15725 tree init;
15731 {
15741 else
15743 }
15745 {
15746 /* Don't build up decls for a variadic capture proxy, we'll
15747 instantiate the elements directly as needed. */
15749 }
15750 else
15751 {
15755 {
15756 /* By marking the declaration as instantiated, we avoid
15757 trying to instantiate it. Since instantiate_decl can't
15758 handle local variables, and since we've already done
15759 all that needs to be done, that's the right thing to
15760 do. */
15765 /* Anonymous aggregates are a special case. */
15768 {
15771 {
15775 }
15777 }
15783 {
15788 }
15789 else
15790 {
15795 {
15796 /* For __PRETTY_FUNCTION__ we have to adjust the
15797 initializer. */
15801 }
15802 else
15806 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15812 {
15814 tree first;
15820 }
15821 }
15822 }
15823 }
15826 }
15841 {
15849 {
15851 tree first;
15856 }
15857 else
15862 }
15888 else
15889 {
15896 }
15902 {
15911 }
15919 else
15927 else
15948 {
15955 }
15959 {
15961 tree label;
15968 }
15974 /* Computed goto's must be tsubst'd into. On the other hand,
15975 non-computed gotos must not be; the identifier in question
15976 will have no binding. */
15978 else
15984 {
16000 }
16005 {
16010 }
16011 else
16012 {
16017 else
16024 else
16030 else
16032 }
16036 {
16040 {
16042 /* Prevent instantiate_decl from trying to instantiate
16043 this variable. We've already done all that needs to be
16044 done. */
16047 }
16052 }
16058 {
16059 /* Local classes are not independent templates; they are
16060 instantiated along with their containing function. And this
16061 way we don't have to deal with pushing out of one local class
16062 to instantiate a member of another local class. */
16063 tree fn;
16064 /* Closures are handled by the LAMBDA_EXPR. */
16071 }
16075 {
16076 tree condition;
16079 condition =
16081 args,
16090 }
16096 in_decl);
16133 {
16148 in_decl);
16150 {
16157 }
16169 integral_constant_expression_p);
16180 else
16181 {
16189 }
16193 }
16198 /* FALLTHRU */
16205 in_decl);
16222 in_decl);
16233 {
16236 {
16237 /* For combined target teams, ensure the num_teams and
16238 thread_limit clause expressions are evaluated on the host,
16239 before entering the target construct. */
16240 tree c;
16246 {
16255 OMP_CLAUSE_FIRSTPRIVATE);
16259 }
16260 }
16261 }
16321 {
16326 {
16329 }
16335 }
16336 else
16337 {
16344 {
16347 }
16350 {
16355 {
16358 }
16364 }
16365 else
16366 {
16370 }
16373 }
16377 {
16383 {
16387 {
16392 }
16396 }
16397 else
16398 {
16403 }
16404 }
16408 {
16412 }
16432 /* If the first operand was a statement, we're done with it. */
16436 complain));
16448 integral_constant_expression_p));
16449 }
16452 out:
16455 #undef RECUR
16456 #undef RETURN
16457 }
16459 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16460 function. For description of the body see comment above
16461 cp_parser_omp_declare_reduction_exprs. */
16463 static void
16465 {
16471 tree_stmt_iterator tsi;
16482 {
16501 }
16503 {
16523 }
16524 }
16526 /* T is a postfix-expression that is not being used in a function
16527 call. Return the substituted version of T. */
16529 static tree
16531 tsubst_flags_t complain,
16532 tree in_decl)
16533 {
16537 else
16543 }
16545 /* Like tsubst but deals with expressions and performs semantic
16546 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16548 tree
16550 tree args,
16551 tsubst_flags_t complain,
16552 tree in_decl,
16555 {
16556 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16557 #define RECUR(NODE) \
16558 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16560 integral_constant_expression_p)
16563 location_t loc;
16572 /* N3276 decltype magic only applies to calls at the top level or on the
16573 right side of a comma. */
16578 {
16581 /* Fall through. */
16583 {
16584 tree decl;
16585 cp_id_kind idk;
16590 {
16593 }
16595 /* Look up the name. */
16598 /* By convention, expressions use ERROR_MARK_NODE to indicate
16599 failure, not NULL_TREE. */
16605 integral_constant_expression_p,
16613 input_location);
16617 {
16621 }
16623 }
16626 {
16627 tree object;
16637 {
16642 }
16648 {
16651 }
16652 else
16659 else
16661 }
16664 {
16668 {
16669 /* A type conversion to reference type will be enclosed in
16670 such an indirect ref, but the substitution of the cast
16671 will have also added such an indirect ref. */
16674 }
16675 else
16683 }
16686 {
16690 }
16693 {
16700 flags));
16701 }
16704 {
16708 }
16715 {
16716 tree type;
16722 {
16727 }
16733 {
16751 }
16754 }
16788 else
16790 in_decl);
16825 {
16832 tree r = build_x_binary_op
16834 op0,
16836 ? ERROR_MARK
16838 op1,
16840 ? ERROR_MARK
16848 }
16851 {
16855 }
16868 {
16877 }
16882 /* Fall through */
16885 {
16886 tree r;
16892 {
16893 /* When there are no ARGS, we are trying to evaluate a
16894 non-dependent expression from the parser. Trying to do
16895 the substitutions may not work. */
16898 }
16899 else
16900 {
16905 else
16908 /*integral_constant_expression_p=*/
16912 }
16916 else
16920 {
16922 {
16924 {
16928 }
16929 else
16933 }
16935 }
16937 }
16940 {
16950 }
16966 {
16970 tree r = build_x_modify_expr
16973 /* TREE_NO_WARNING must be set if either the expression was
16974 parenthesized or it uses an operator such as >>= rather
16975 than plain assignment. In the former case, it was already
16976 set and must be copied. In the latter case,
16977 build_x_modify_expr sets it and it must not be reset
16978 here. */
16983 }
16988 /* Remember that there was a reference to this entity. */
16995 {
17000 tree ret;
17004 else
17005 {
17009 }
17011 /* If there was an initializer in the original tree, but it
17012 instantiated to an empty list, then we should pass a
17013 non-NULL empty vector to tell build_new that it was an
17014 empty initializer() rather than no initializer. This can
17015 only happen when the initializer is a pack expansion whose
17016 parameter packs are of length zero. */
17019 else
17020 {
17024 else
17025 {
17028 }
17029 }
17035 complain);
17043 }
17046 {
17052 complain));
17053 }
17056 {
17060 integral_constant_expression_p);
17062 op0,
17065 }
17068 {
17069 tree function;
17074 tree ret;
17077 /* Internal function with no arguments. */
17081 /* When we parsed the expression, we determined whether or
17082 not Koenig lookup should be performed. */
17085 {
17088 }
17090 {
17095 }
17097 {
17098 /* Do nothing; calling tsubst_copy_and_build on an identifier
17099 would incorrectly perform unqualified lookup again.
17101 Note that we can also have an IDENTIFIER_NODE if the earlier
17102 unqualified lookup found a member function; in that case
17103 koenig_p will be false and we do want to do the lookup
17104 again to find the instantiated member function.
17106 FIXME but doing that causes c++/15272, so we need to stop
17107 using IDENTIFIER_NODE in that situation. */
17109 }
17110 else
17111 {
17113 {
17119 }
17120 else
17125 /* Avoid error about taking the address of a constructor. */
17129 in_decl,
17131 integral_constant_expression_p);
17135 }
17140 {
17145 else
17146 {
17147 /* Expand the pack expansion and push each entry onto
17148 CALL_ARGS. */
17151 {
17156 {
17161 }
17162 }
17163 else
17164 {
17165 /* A partial substitution. Add one entry. */
17167 }
17168 }
17169 }
17171 /* We do not perform argument-dependent lookup if normal
17172 lookup finds a non-function, in accordance with the
17173 expected resolution of DR 218. */
17176 /* If lookup found a member function, the Koenig lookup is
17177 not appropriate, even if an unqualified-name was used
17178 to denote the function. */
17181 /* Only do this when substitution turns a dependent call
17182 into a non-dependent call. */
17190 {
17192 {
17193 /* For backwards compatibility and good diagnostics, try
17194 the unqualified lookup again if we aren't in SFINAE
17195 context. */
17196 tree unq = (tsubst_copy_and_build
17198 integral_constant_expression_p));
17200 {
17203 }
17206 {
17207 /* In a lambda fn, we have to be careful to not
17208 introduce new this captures. Legacy code can't
17209 be using lambdas anyway, so it's ok to be
17210 stricter. */
17215 "and no declarations were found by "
17216 "argument-dependent lookup at the point "
17223 else
17227 {
17239 {
17241 input_location);
17243 "declarations in dependent base %qT are "
17249 else
17253 }
17254 else
17256 "%qD declared here, later in the "
17259 {
17262 }
17263 }
17266 }
17267 }
17269 {
17274 }
17275 }
17277 /* Remember that there was a reference to this entity. */
17281 {
17284 }
17286 /* Put back tf_decltype for the actual call. */
17291 {
17295 {
17297 "wrong number of arguments to "
17300 }
17301 else
17303 input_location),
17308 /* Unsupported internal function with arguments. */
17310 }
17313 complain);
17315 {
17330 complain);
17331 else
17332 ret = (build_new_method_call
17337 complain));
17338 }
17339 else
17342 koenig_p,
17343 complain);
17348 {
17354 {
17360 {
17362 /* The thunk location is not interesting. */
17364 }
17365 }
17366 }
17369 }
17372 {
17378 {
17380 {
17385 }
17386 else
17387 {
17392 }
17394 }
17395 else
17396 {
17399 }
17403 }
17406 {
17411 input_location));
17412 }
17415 {
17423 {
17424 /* We have pack expansions, so expand those and
17425 create a new list out of it. */
17428 tree chain;
17431 /* Expand the argument expressions. */
17439 /* Build the rest of the list. */
17444 /* Determine the number of arguments. */
17446 {
17449 }
17452 else
17453 {
17454 /* Since we only performed a partial substitution into
17455 the argument pack, we only RETURN (a single list
17456 node. */
17463 }
17465 /* Convert the argument vectors into a TREE_LIST */
17468 {
17469 /* Grab the Ith values. */
17470 i--;
17473 value
17477 /* Build the list (backwards). */
17479 }
17482 }
17498 }
17501 {
17502 tree object;
17503 tree object_type;
17504 tree member;
17505 tree r;
17509 /* Remember that there was a reference to this entity. */
17520 else
17526 {
17531 }
17535 {
17537 {
17542 {
17545 }
17547 {
17552 }
17553 }
17554 }
17557 {
17558 /* Lookup the template functions now that we know what the
17559 scope is. */
17567 {
17570 args);
17571 member = (adjust_result_of_qualified_name_lookup
17573 object_type));
17574 }
17575 else
17576 {
17578 input_location);
17580 }
17581 }
17585 {
17587 {
17591 else
17594 }
17596 }
17600 complain);
17604 }
17611 {
17619 tree r;
17624 /* digest_init will do the wrong thing if we let it. */
17628 /* We do not want to process the index of aggregate
17629 initializers as they are identifier nodes which will be
17630 looked up by digest_init. */
17636 {
17638 /* An identifier index is looked up in the type
17639 being initialized, not the current scope. */
17644 {
17645 /* Substitute into the pack expansion. */
17647 in_decl);
17651 ;
17653 /* Just move the argument into place. */
17655 else
17656 {
17657 /* Update the length of the final CONSTRUCTOR
17658 arguments vector, and note that we will need to
17659 copy.*/
17662 }
17663 }
17664 else
17666 }
17669 {
17674 {
17676 {
17681 }
17682 else
17684 }
17685 }
17695 }
17698 {
17701 {
17704 }
17705 else
17706 {
17709 }
17710 }
17716 {
17717 /* We don't build decls for an instantiation of a
17718 variadic capture proxy, we instantiate the elements
17719 when needed. */
17722 }
17723 /* Fall through */
17726 {
17728 /* ??? We're doing a subset of finish_id_expression here. */
17730 && !processing_template_decl
17731 && !cp_unevaluated_operand
17734 {
17736 /* Replace an evaluated use of the thread_local variable with
17737 a call to its wrapper. */
17739 }
17741 {
17745 }
17748 /* If the original type was a reference, we'll be wrapped in
17749 the appropriate INDIRECT_REF. */
17752 }
17755 {
17759 }
17762 {
17763 tree object_ptr
17770 }
17777 {
17788 }
17791 {
17797 integral_constant_expression_p);
17801 /* If the resulting list of expression statement is empty,
17802 fold it further into void_node. */
17807 }
17810 {
17828 /* For a function or variable scope, we want to use tsubst so that we
17829 don't complain about referring to an auto before deduction. */
17832 {
17833 /* Look up the parameter we want directly, as tsubst_copy
17834 doesn't do what we need. */
17840 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17843 }
17845 /* For a field, use tsubst_copy so that we look up the existing field
17846 rather than build a new one. */
17848 else
17855 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17857 /* Now that we know visibility, instantiate the type so we have a
17858 declaration of the op() for later calls to lambda_function. */
17869 }
17872 /* We can get here for a constant initializer of non-dependent type.
17873 FIXME stop folding in cp_parser_initializer_clause. */
17874 {
17876 complain);
17878 }
17882 integral_constant_expression_p));
17888 {
17893 complain));
17894 }
17900 /* Handle Objective-C++ constructs, if appropriate. */
17901 {
17902 tree subst
17907 }
17909 }
17911 #undef RECUR
17912 #undef RETURN
17913 out:
17916 }
17918 /* Verify that the instantiated ARGS are valid. For type arguments,
17919 make sure that the type's linkage is ok. For non-type arguments,
17920 make sure they are constants if they are integral or enumerations.
17921 Emit an error under control of COMPLAIN, and return TRUE on error. */
17923 static bool
17925 {
17929 {
17939 }
17941 {
17942 /* [basic.link]: A name with no linkage (notably, the name
17943 of a class or enumeration declared in a local scope)
17944 shall not be used to declare an entity with linkage.
17945 This implies that names with no linkage cannot be used as
17946 template arguments
17948 DR 757 relaxes this restriction for C++0x. */
17953 {
17954 /* DR 488 makes use of a type with no linkage cause
17955 type deduction to fail. */
17957 {
17960 else
17963 }
17965 }
17966 /* In order to avoid all sorts of complications, we do not
17967 allow variably-modified types as template arguments. */
17969 {
17973 }
17974 }
17975 /* Class template and alias template arguments should be OK. */
17977 ;
17978 /* A non-type argument of integral or enumerated type must be a
17979 constant. */
17984 {
17988 }
17990 }
17992 static bool
17994 {
17999 {
18002 }
18006 }
18008 /* We're out of SFINAE context now, so generate diagnostics for the access
18009 errors we saw earlier when instantiating D from TMPL and ARGS. */
18011 static void
18013 {
18025 }
18027 /* Instantiate the indicated variable, function, or alias template TMPL with
18028 the template arguments in TARG_PTR. */
18030 static tree
18032 {
18034 tree fndecl;
18035 tree gen_tmpl;
18036 tree spec;
18044 /* If this function is a clone, handle it specially. */
18046 {
18047 tree spec;
18048 tree clone;
18050 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18051 DECL_CLONED_FUNCTION. */
18057 /* Look for the clone. */
18061 /* We should always have found the clone by now. */
18064 }
18069 /* Check to see if we already have this specialization. */
18073 /* targ_ptr only has the innermost template args, so add the outer ones
18074 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18075 the case of a non-dependent call within a template definition). */
18076 targ_ptr = (add_outermost_template_args
18078 targ_ptr));
18080 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18081 but it doesn't seem to be on the hot path. */
18090 {
18092 {
18096 }
18098 }
18101 complain))
18104 /* We are building a FUNCTION_DECL, during which the access of its
18105 parameters and return types have to be checked. However this
18106 FUNCTION_DECL which is the desired context for access checking
18107 is not built yet. We solve this chicken-and-egg problem by
18108 deferring all checks until we have the FUNCTION_DECL. */
18111 /* Instantiation of the function happens in the context of the function
18112 template, not the context of the overload resolution we're doing. */
18114 /* If there are dependent arguments, e.g. because we're doing partial
18115 ordering, make sure processing_template_decl stays set. */
18119 {
18123 }
18129 {
18130 /* We need to determine if we're using a partial or explicit
18131 specialization now, because the type of the variable could be
18132 different. */
18138 {
18143 }
18144 }
18146 /* Substitute template parameters to obtain the specialization. */
18154 {
18157 }
18159 /* The DECL_TI_TEMPLATE should always be the immediate parent
18160 template, not the most general template. */
18164 /* Now we know the specialization, compute access previously
18165 deferred. Do no access control for inheriting constructors,
18166 as we already checked access for the inherited constructor. */
18169 {
18174 }
18177 /* If we've just instantiated the main entry point for a function,
18178 instantiate all the alternate entry points as well. We do this
18179 by cloning the instantiation of the main entry point, not by
18180 instantiating the template clones. */
18185 {
18187 {
18188 /* Remember to reinstantiate when we're out of SFINAE so the user
18189 can see the errors. */
18191 }
18193 }
18195 }
18197 /* Wrapper for instantiate_template_1. */
18199 tree
18201 {
18202 tree ret;
18207 }
18209 /* Instantiate the alias template TMPL with ARGS. Also push a template
18210 instantiation level, which instantiate_template doesn't do because
18211 functions and variables have sufficient context established by the
18212 callers. */
18214 static tree
18216 {
18223 {
18226 }
18228 args =
18236 /* We can't free this if a pending_template entry or last_error_tinst_level
18237 is pointing at it. */
18243 }
18245 /* PARM is a template parameter pack for FN. Returns true iff
18246 PARM is used in a deducible way in the argument list of FN. */
18248 static bool
18250 {
18253 {
18255 tree packs;
18261 {
18262 /* The template parameter pack is used in a function parameter
18263 pack. If this is the end of the parameter list, the
18264 template parameter pack is deducible. */
18267 else
18268 /* Otherwise, not. Well, it could be deduced from
18269 a non-pack parameter, but doing so would end up with
18270 a deduction mismatch, so don't bother. */
18272 }
18273 }
18274 /* The template parameter pack isn't used in any function parameter
18275 packs, but it might be used deeper, e.g. tuple<Args...>. */
18277 }
18279 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18280 NARGS elements of the arguments that are being used when calling
18281 it. TARGS is a vector into which the deduced template arguments
18282 are placed.
18284 Returns either a FUNCTION_DECL for the matching specialization of FN or
18285 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18286 true, diagnostics will be printed to explain why it failed.
18288 If FN is a conversion operator, or we are trying to produce a specific
18289 specialization, RETURN_TYPE is the return type desired.
18291 The EXPLICIT_TARGS are explicit template arguments provided via a
18292 template-id.
18294 The parameter STRICT is one of:
18296 DEDUCE_CALL:
18297 We are deducing arguments for a function call, as in
18298 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18299 deducing arguments for a call to the result of a conversion
18300 function template, as in [over.call.object].
18302 DEDUCE_CONV:
18303 We are deducing arguments for a conversion function, as in
18304 [temp.deduct.conv].
18306 DEDUCE_EXACT:
18307 We are deducing arguments when doing an explicit instantiation
18308 as in [temp.explicit], when determining an explicit specialization
18309 as in [temp.expl.spec], or when taking the address of a function
18310 template, as in [temp.deduct.funcaddr]. */
18312 tree
18314 tree explicit_targs,
18315 tree targs,
18318 tree return_type,
18319 unification_kind_t strict,
18323 {
18324 tree parms;
18325 tree fntype;
18338 tree tinst;
18344 full_targs = (add_outermost_template_args
18346 targs));
18351 /* In C++0x, it's possible to have a function template whose type depends
18352 on itself recursively. This is most obvious with decltype, but can also
18353 occur with enumeration scope (c++/48969). So we need to catch infinite
18354 recursion and reject the substitution at deduction time; this function
18355 will return error_mark_node for any repeated substitution.
18357 This also catches excessive recursion such as when f<N> depends on
18358 f<N-1> across all integers, and returns error_mark_node for all the
18359 substitutions back up to the initial one.
18361 This is, of course, not reentrant. */
18371 {
18372 /* [temp.deduct]
18374 The specified template arguments must match the template
18375 parameters in kind (i.e., type, nontype, template), and there
18376 must not be more arguments than there are parameters;
18377 otherwise type deduction fails.
18379 Nontype arguments must match the types of the corresponding
18380 nontype template parameters, or must be convertible to the
18381 types of the corresponding nontype parameters as specified in
18382 _temp.arg.nontype_, otherwise type deduction fails.
18384 All references in the function type of the function template
18385 to the corresponding template parameters are replaced by the
18386 specified template argument values. If a substitution in a
18387 template parameter or in the function type of the function
18388 template results in an invalid type, type deduction fails. */
18399 explicit_targs);
18401 /* Adjust any explicit template arguments before entering the
18402 substitution context. */
18403 explicit_targs
18405 complain,
18411 /* Substitute the explicit args into the function type. This is
18412 necessary so that, for instance, explicitly declared function
18413 arguments can match null pointed constants. If we were given
18414 an incomplete set of explicit args, we must not do semantic
18415 processing during substitution as we could create partial
18416 instantiations. */
18418 {
18423 /* Dig out the actual parm. */
18426 {
18429 }
18431 {
18434 }
18437 /* No explicit argument for this template parameter. */
18441 {
18442 /* Mark the argument pack as "incomplete". We could
18443 still deduce more arguments during unification.
18444 We remove this mark in type_unification_real. */
18446 {
18450 }
18452 /* We have some incomplete argument packs. */
18454 }
18455 }
18459 {
18462 }
18465 /* Ignore any access checks; we'll see them again in
18466 instantiate_template and they might have the wrong
18467 access path at this point. */
18479 /* Place the explicitly specified arguments in TARGS. */
18483 }
18485 /* Never do unification on the 'this' parameter. */
18489 {
18490 /* We're deducing for a call to the result of a template conversion
18491 function. The parms we really want are in return_type. */
18495 }
18497 {
18506 }
18508 /* We allow incomplete unification without an error message here
18509 because the standard doesn't seem to explicitly prohibit it. Our
18510 callers must be ready to deal with unification failures in any
18511 event. */
18514 /* If we aren't explaining yet, push tinst context so we can see where
18515 any errors (e.g. from class instantiations triggered by instantiation
18516 of default template arguments) come from. If we are explaining, this
18517 context is redundant. */
18519 {
18522 }
18524 /* type_unification_real will pass back any access checks from default
18525 template argument substitution. */
18537 /* Now that we have bindings for all of the template arguments,
18538 ensure that the arguments deduced for the template template
18539 parameters have compatible template parameter lists. We cannot
18540 check this property before we have deduced all template
18541 arguments, because the template parameter types of a template
18542 template parameter might depend on prior template parameters
18543 deduced after the template template parameter. The following
18544 ill-formed example illustrates this issue:
18546 template<typename T, template<T> class C> void f(C<5>, T);
18548 template<int N> struct X {};
18550 void g() {
18551 f(X<5>(), 5l); // error: template argument deduction fails
18552 }
18554 The template parameter list of 'C' depends on the template type
18555 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18556 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18557 time that we deduce 'C'. */
18560 {
18563 }
18565 /* All is well so far. Now, check:
18567 [temp.deduct]
18569 When all template arguments have been deduced, all uses of
18570 template parameters in nondeduced contexts are replaced with
18571 the corresponding deduced argument values. If the
18572 substitution results in an invalid type, as described above,
18573 type deduction fails. */
18576 {
18579 }
18581 /* Also collect access checks from the instantiation. */
18594 /* Now perform any access checks encountered during substitution. */
18601 /* If we're looking for an exact match, check that what we got
18602 is indeed an exact match. It might not be if some template
18603 parameters are used in non-deduced contexts. But don't check
18604 for an exact match if we have dependent template arguments;
18605 in that case we're doing partial ordering, and we already know
18606 that we have two candidates that will provide the actual type. */
18608 {
18612 tree sarg
18618 {
18622 }
18623 }
18625 /* After doing deduction with the inherited constructor, actually return an
18626 instantiation of the inheriting constructor. */
18632 fail:
18635 {
18637 /* Reset once we're all the way out. */
18639 }
18641 /* We can't free this if a pending_template entry or last_error_tinst_level
18642 is pointing at it. */
18648 }
18650 /* Adjust types before performing type deduction, as described in
18651 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18652 sections are symmetric. PARM is the type of a function parameter
18653 or the return type of the conversion function. ARG is the type of
18654 the argument passed to the call, or the type of the value
18655 initialized with the result of the conversion function.
18656 ARG_EXPR is the original argument expression, which may be null. */
18658 static int
18662 tree arg_expr)
18663 {
18667 {
18672 /* Swap PARM and ARG throughout the remainder of this
18673 function; the handling is precisely symmetric since PARM
18674 will initialize ARG rather than vice versa. */
18679 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18680 too, but here handle it by stripping the reference from PARM
18681 rather than by adding it to ARG. */
18689 /* Nothing else to do in this case. */
18694 }
18697 {
18698 /* [temp.deduct.call]
18700 If P is not a reference type:
18702 --If A is an array type, the pointer type produced by the
18703 array-to-pointer standard conversion (_conv.array_) is
18704 used in place of A for type deduction; otherwise,
18706 --If A is a function type, the pointer type produced by
18707 the function-to-pointer standard conversion
18708 (_conv.func_) is used in place of A for type deduction;
18709 otherwise,
18711 --If A is a cv-qualified type, the top level
18712 cv-qualifiers of A's type are ignored for type
18713 deduction. */
18718 else
18720 }
18722 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18723 reference to a cv-unqualified template parameter that does not represent a
18724 template parameter of a class template (during class template argument
18725 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18726 an lvalue, the type "lvalue reference to A" is used in place of A for type
18727 deduction. */
18734 /* try_one_overload doesn't provide an arg_expr, but
18735 functions are always lvalues. */
18739 /* [temp.deduct.call]
18741 If P is a cv-qualified type, the top level cv-qualifiers
18742 of P's type are ignored for type deduction. If P is a
18743 reference type, the type referred to by P is used for
18744 type deduction. */
18747 {
18750 }
18752 /* DR 322. For conversion deduction, remove a reference type on parm
18753 too (which has been swapped into ARG). */
18758 }
18760 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18761 template which does contain any deducible template parameters; check if
18762 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18763 unify_one_argument. */
18765 static int
18768 {
18769 tree type;
18773 else
18780 {
18784 }
18786 {
18791 }
18795 else
18797 }
18801 /* Returns true iff the expression EXPR is one from which a template
18802 argument can be deduced. In other words, if it's an undecorated
18803 use of a template non-type parameter. */
18805 static bool
18807 {
18808 /* Strip implicit conversions. */
18812 }
18814 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18815 deducible way; that is, if it has a max value of <PARM> - 1. */
18817 static bool
18819 {
18828 }
18830 /* Returns true iff the template arguments ARGS use a template parameter
18831 in a deducible way. */
18833 static bool
18835 {
18837 {
18842 else
18843 {
18850 else
18852 }
18855 }
18857 }
18859 /* Returns true iff TYPE contains any deducible references to template
18860 parameters, as per 14.8.2.5. */
18862 static bool
18864 {
18868 /* T
18869 cv-list T
18870 TT<T>
18871 TT<i>
18872 TT<> */
18877 /* T*
18878 T&
18879 T&& */
18883 /* T[integer-constant ]
18884 type [i] */
18889 /* T type ::*
18890 type T::*
18891 T T::*
18892 T (type ::*)()
18893 type (T::*)()
18894 type (type ::*)(T)
18895 type (T::*)(T)
18896 T (type ::*)(T)
18897 T (T::*)()
18898 T (T::*)(T) */
18901 || (uses_deducible_template_parms
18904 /* template-name <T> (where template-name refers to a class template)
18905 template-name <i> (where template-name refers to a class template) */
18912 /* type (T)
18913 T()
18914 T(T) */
18917 {
18926 }
18929 }
18931 /* Subroutine of type_unification_real and unify_pack_expansion to
18932 handle unification of a single P/A pair. Parameters are as
18933 for those functions. */
18935 static int
18939 {
18946 /* We can't deduce anything from this, but we might get all the
18947 template args from other function args. */
18950 /* Implicit conversions (Clause 4) will be performed on a function
18951 argument to convert it to the type of the corresponding function
18952 parameter if the parameter type contains no template-parameters that
18953 participate in template argument deduction. */
18956 /* For function parameters with no deducible template parameters,
18957 just return. We'll check non-dependent conversions later. */
18961 {
18963 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
18964 | UNIFY_ALLOW_MORE_CV_QUAL
18978 }
18980 /* We only do these transformations if this is the top-level
18981 parameter_type_list in a call or declaration matching; in other
18982 situations (nested function declarators, template argument lists) we
18983 won't be comparing a type to an expression, and we don't do any type
18984 adjustments. */
18986 {
18988 {
18991 {
18992 /* [temp.deduct.type] A template-argument can be
18993 deduced from a pointer to function or pointer
18994 to member function argument if the set of
18995 overloaded functions does not contain function
18996 templates and at most one of a set of
18997 overloaded functions provides a unique
18998 match. */
19005 }
19011 }
19013 arg_strict |=
19015 }
19016 else
19021 /* For deduction from an init-list we need the actual list. */
19025 }
19027 /* for_each_template_parm callback that always returns 0. */
19029 static int
19031 {
19033 }
19035 /* for_each_template_parm any_fn callback to handle deduction of a template
19036 type argument from the type of an array bound. */
19038 static int
19040 {
19048 {
19054 }
19056 /* Keep walking. */
19058 }
19060 /* Try to deduce any not-yet-deduced template type arguments from the type of
19061 an array bound. This is handled separately from unify because 14.8.2.5 says
19062 "The type of a type parameter is only deduced from an array bound if it is
19063 not otherwise deduced." */
19065 static void
19067 {
19072 }
19074 /* Most parms like fn_type_unification.
19076 If SUBR is 1, we're being called recursively (to unify the
19077 arguments of a function or method parameter of a function
19078 template).
19080 CHECKS is a pointer to a vector of access checks encountered while
19081 substituting default template arguments. */
19083 static int
19085 tree full_targs,
19086 tree xparms,
19090 unification_kind_t strict,
19094 {
19099 tree parms;
19110 /* Reset the number of non-defaulted template arguments contained
19111 in TARGS. */
19114 again:
19122 {
19127 /* For a function parameter pack that occurs at the end of the
19128 parameter-declaration-list, the type A of each remaining
19129 argument of the call is compared with the type P of the
19130 declarator-id of the function parameter pack. */
19136 /* For a function parameter pack that does not occur at the
19137 end of the parameter-declaration-list, the type of the
19138 parameter pack is a non-deduced context. */
19145 explain_p))
19147 }
19152 {
19153 /* Unify the remaining arguments with the pack expansion type. */
19154 tree argvec;
19157 /* Allocate a TREE_VEC and copy in all of the arguments */
19162 /* Copy the parameter into parmvec. */
19168 /* Advance to the end of the list of parameters. */
19170 }
19172 /* Fail if we've reached the end of the parm list, and more args
19173 are present, and the parm list isn't variadic. */
19176 /* Fail if parms are left and they don't have default values and
19177 they aren't all deduced as empty packs (c++/57397). This is
19178 consistent with sufficient_parms_p. */
19181 {
19185 do
19186 {
19189 count++;
19191 }
19195 type_pack_p);
19196 }
19199 {
19200 tsubst_flags_t complain = (explain_p
19201 ? tf_warning_or_error
19206 {
19210 /* Clear the "incomplete" flags on all argument packs now so that
19211 substituting them into later default arguments works. */
19213 {
19216 }
19224 {
19229 }
19231 /* If this is an undeduced nontype parameter that depends on
19232 a type parameter, try another pass; its type may have been
19233 deduced from a later argument than the one from which
19234 this parameter can be deduced. */
19238 {
19241 }
19243 /* Core issue #226 (C++0x) [temp.deduct]:
19245 If a template argument has not been deduced, its
19246 default template argument, if any, is used.
19248 When we are in C++98 mode, TREE_PURPOSE will either
19249 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19250 to explicitly check cxx_dialect here. */
19252 /* OK, there is a default argument. Wait until after the
19253 conversion check to do substitution. */
19256 /* If the type parameter is a parameter pack, then it will
19257 be deduced to an empty parameter pack. */
19259 {
19260 tree arg;
19263 {
19267 }
19268 else
19275 }
19278 }
19280 /* DR 1391: All parameters have args, now check non-dependent parms for
19281 convertibility. */
19285 {
19291 /* For a function parameter pack that occurs at the end of the
19292 parameter-declaration-list, the type A of each remaining
19293 argument of the call is compared with the type P of the
19294 declarator-id of the function parameter pack. */
19300 /* For a function parameter pack that does not occur at the
19301 end of the parameter-declaration-list, the type of the
19302 parameter pack is a non-deduced context. */
19311 explain_p))
19313 }
19315 /* Now substitute into the default template arguments. */
19317 {
19341 else
19349 {
19351 /* The position of the first default template argument,
19352 is also the number of non-defaulted arguments in TARGS.
19353 Record that. */
19356 }
19357 }
19361 }
19367 }
19369 /* Subroutine of type_unification_real. Args are like the variables
19370 at the call site. ARG is an overloaded function (or template-id);
19371 we try deducing template args from each of the overloads, and if
19372 only one succeeds, we go with that. Modifies TARGS and returns
19373 true on success. */
19375 static bool
19377 tree targs,
19378 tree parm,
19379 tree arg,
19380 unification_kind_t strict,
19383 {
19390 {
19393 }
19394 else
19398 /* Handle `&x' where `x' is some static or non-static member
19399 function name. */
19405 /* Strip baselink information. */
19410 {
19411 /* If we got some explicit template args, we need to plug them into
19412 the affected templates before we try to unify, in case the
19413 explicit args will completely resolve the templates in question. */
19420 {
19433 {
19438 {
19441 }
19442 }
19445 }
19446 /* If no templates (or more than one) are fully resolved by the
19447 explicit arguments, this template-id is a non-deduced context; it
19448 could still be OK if we deduce all template arguments for the
19449 enclosing call through other arguments. */
19452 }
19455 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19456 -- but the deduction does not succeed because the expression is
19457 not just the function on its own. */
19459 else
19465 {
19468 }
19470 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19471 to function or pointer to member function argument if the set of
19472 overloaded functions does not contain function templates and at most
19473 one of a set of overloaded functions provides a unique match.
19475 So if we found multiple possibilities, we return success but don't
19476 deduce anything. */
19479 {
19483 {
19488 /* Don't forget explicit template arguments in a pack. */
19492 }
19493 }
19498 }
19500 /* Core DR 115: In contexts where deduction is done and fails, or in
19501 contexts where deduction is not done, if a template argument list is
19502 specified and it, along with any default template arguments, identifies
19503 a single function template specialization, then the template-id is an
19504 lvalue for the function template specialization. */
19506 tree
19508 {
19521 {
19524 }
19526 {
19529 }
19531 {
19534 }
19537 {
19541 /* If we got some explicit template args, we need to plug them into
19542 the affected templates before we try to unify, in case the
19543 explicit args will completely resolve the templates in question. */
19551 {
19564 {
19567 {
19570 }
19572 {
19575 }
19576 }
19577 }
19579 {
19587 {
19588 tree base
19591 }
19595 }
19597 /* There were no good options and at least one bad one, so let the
19598 user know what the problem is. */
19600 }
19602 }
19604 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19605 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19606 different overloads deduce different arguments for a given parm.
19607 ADDR_P is true if the expression for which deduction is being
19608 performed was of the form "& fn" rather than simply "fn".
19610 Returns 1 on success. */
19612 static int
19614 tree orig_targs,
19615 tree targs,
19616 tree parm,
19617 tree arg,
19618 unification_kind_t strict,
19622 {
19624 tree tempargs;
19630 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19631 to function or pointer to member function argument if the set of
19632 overloaded functions does not contain function templates and at most
19633 one of a set of overloaded functions provides a unique match.
19635 So if this is a template, just return success. */
19647 /* We don't copy orig_targs for this because if we have already deduced
19648 some template args from previous args, unify would complain when we
19649 try to deduce a template parameter for the same argument, even though
19650 there isn't really a conflict. */
19657 /* First make sure we didn't deduce anything that conflicts with
19658 explicitly specified args. */
19660 {
19667 /* Since we're unifying against ourselves, we will fill in
19668 template args used in the function parm list with our own
19669 template parms. Discard them. */
19672 {
19673 /* Check that the argument at each index of the deduced argument pack
19674 is equivalent to the corresponding explicitly specified argument.
19675 We may have deduced more arguments than were explicitly specified,
19676 and that's OK. */
19692 }
19695 }
19698 {
19703 }
19706 }
19708 /* PARM is a template class (perhaps with unbound template
19709 parameters). ARG is a fully instantiated type. If ARG can be
19710 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19711 TARGS are as for unify. */
19713 static tree
19716 {
19717 tree copy_of_targs;
19727 /* We need to make a new template argument vector for the call to
19728 unify. If we used TARGS, we'd clutter it up with the result of
19729 the attempted unification, even if this class didn't work out.
19730 We also don't want to commit ourselves to all the unifications
19731 we've already done, since unification is supposed to be done on
19732 an argument-by-argument basis. In other words, consider the
19733 following pathological case:
19735 template <int I, int J, int K>
19736 struct S {};
19738 template <int I, int J>
19739 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19741 template <int I, int J, int K>
19742 void f(S<I, J, K>, S<I, I, I>);
19744 void g() {
19745 S<0, 0, 0> s0;
19746 S<0, 1, 2> s2;
19748 f(s0, s2);
19749 }
19751 Now, by the time we consider the unification involving `s2', we
19752 already know that we must have `f<0, 0, 0>'. But, even though
19753 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19754 because there are two ways to unify base classes of S<0, 1, 2>
19755 with S<I, I, I>. If we kept the already deduced knowledge, we
19756 would reject the possibility I=1. */
19760 {
19764 }
19766 /* If unification failed, we're done. */
19772 }
19774 /* Given a template type PARM and a class type ARG, find the unique
19775 base type in ARG that is an instance of PARM. We do not examine
19776 ARG itself; only its base-classes. If there is not exactly one
19777 appropriate base class, return NULL_TREE. PARM may be the type of
19778 a partial specialization, as well as a plain template type. Used
19779 by unify. */
19781 static enum template_base_result
19784 {
19786 tree binfo;
19792 {
19793 /* The type could not be completed. */
19796 }
19798 /* Walk in inheritance graph order. The search order is not
19799 important, and this avoids multiple walks of virtual bases. */
19801 {
19806 {
19807 /* If there is more than one satisfactory baseclass, then:
19809 [temp.deduct.call]
19811 If they yield more than one possible deduced A, the type
19812 deduction fails.
19814 applies. */
19816 {
19819 }
19822 }
19823 }
19827 }
19829 /* Returns the level of DECL, which declares a template parameter. */
19831 static int
19833 {
19835 {
19845 }
19847 }
19849 /* Decide whether ARG can be unified with PARM, considering only the
19850 cv-qualifiers of each type, given STRICT as documented for unify.
19851 Returns nonzero iff the unification is OK on that basis. */
19853 static int
19855 {
19861 {
19862 /* Although a CVR qualifier is ignored when being applied to a
19863 substituted template parameter ([8.3.2]/1 for example), that
19864 does not allow us to unify "const T" with "int&" because both
19865 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19866 It is ok when we're allowing additional CV qualifiers
19867 at the outer level [14.8.2.1]/3,1st bullet. */
19877 }
19888 }
19890 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19891 void
19893 {
19897 {
19900 }
19901 else
19902 {
19905 }
19906 }
19908 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19909 do { \
19910 if (unify (TP, TA, P, A, S, EP)) \
19911 return 1; \
19912 } while (0)
19914 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19915 expansion at the end of PACKED_PARMS. Returns 0 if the type
19916 deduction succeeds, 1 otherwise. STRICT is the same as in
19917 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
19918 function call argument list. We'll need to adjust the arguments to make them
19919 types. SUBR tells us if this is from a recursive call to
19920 type_unification_real, or for comparing two template argument
19921 lists. */
19923 static int
19927 {
19928 tree parm
19938 /* Determine the parameter packs we will be deducing from the
19939 pattern, and record their current deductions. */
19942 {
19946 /* Determine the index and level of this parameter pack. */
19949 /* Keep track of the parameter packs and their corresponding
19950 argument packs. */
19953 }
19955 /* Loop through all of the arguments that have not yet been
19956 unified and unify each with the pattern. */
19958 {
19959 tree parm;
19963 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
19964 or the element of its argument pack at the current index if
19965 this argument was explicitly specified. */
19967 {
19976 {
19979 }
19981 }
19983 /* If we had explicit template arguments, substitute them into the
19984 pattern before deduction. */
19986 {
19987 /* Some arguments might still be unspecified or dependent. */
19995 NULL_TREE);
20000 }
20001 else
20004 /* Unify the pattern with the current argument. */
20006 explain_p))
20009 /* For each parameter pack, collect the deduced value. */
20011 {
20017 }
20018 }
20020 /* Verify that the results of unification with the parameter packs
20021 produce results consistent with what we've seen before, and make
20022 the deduced argument packs available. */
20024 {
20031 /* By default keep the original deduced argument pack.
20032 If necessary, more specific code is going to update the
20033 resulting deduced argument later down in this function. */
20037 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20038 actually deduce anything. */
20046 {
20047 /* If we had fewer function args than explicit template args,
20048 just use the explicits. */
20053 }
20056 {
20057 tree result;
20058 /* Build the deduced *_ARGUMENT_PACK. */
20060 {
20065 }
20066 else
20071 /* Note the deduced argument packs for this parameter
20072 pack. */
20074 }
20078 {
20079 /* We only had the explicitly-provided arguments before, but
20080 now we have a complete set of arguments. */
20086 }
20087 else
20088 {
20094 /* Inconsistent unification of this parameter pack. */
20096 bad_old_arg,
20097 bad_new_arg);
20098 }
20099 }
20102 }
20104 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20105 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20106 parameters and return value are as for unify. */
20108 static int
20112 {
20113 tree parm_max;
20114 tree arg_max;
20118 /* Our representation of array types uses "N - 1" as the
20119 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20120 not an integer constant. We cannot unify arbitrarily
20121 complex expressions, so we eliminate the MINUS_EXPRs
20122 here. */
20126 {
20129 }
20133 {
20134 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20135 trying to unify the type of a variable with the type
20136 of a template parameter. For example:
20138 template <unsigned int N>
20139 void f (char (&) [N]);
20140 int g();
20141 void h(int i) {
20142 char a[g(i)];
20143 f(a);
20144 }
20146 Here, the type of the ARG will be "int [g(i)]", and
20147 may be a SAVE_EXPR, etc. */
20151 }
20153 /* If only one of the bounds used a MINUS_EXPR, compensate
20154 by adding one to the other bound. */
20157 integer_type_node,
20158 parm_max,
20159 integer_one_node);
20162 integer_type_node,
20163 arg_max,
20164 integer_one_node);
20168 }
20170 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20174 static pa_kind_t
20176 {
20185 else
20187 }
20189 /* Deduce the value of template parameters. TPARMS is the (innermost)
20190 set of template parameters to a template. TARGS is the bindings
20191 for those template parameters, as determined thus far; TARGS may
20192 include template arguments for outer levels of template parameters
20193 as well. PARM is a parameter to a template function, or a
20194 subcomponent of that parameter; ARG is the corresponding argument.
20195 This function attempts to match PARM with ARG in a manner
20196 consistent with the existing assignments in TARGS. If more values
20197 are deduced, then TARGS is updated.
20199 Returns 0 if the type deduction succeeds, 1 otherwise. The
20200 parameter STRICT is a bitwise or of the following flags:
20202 UNIFY_ALLOW_NONE:
20203 Require an exact match between PARM and ARG.
20204 UNIFY_ALLOW_MORE_CV_QUAL:
20205 Allow the deduced ARG to be more cv-qualified (by qualification
20206 conversion) than ARG.
20207 UNIFY_ALLOW_LESS_CV_QUAL:
20208 Allow the deduced ARG to be less cv-qualified than ARG.
20209 UNIFY_ALLOW_DERIVED:
20210 Allow the deduced ARG to be a template base class of ARG,
20211 or a pointer to a template base class of the type pointed to by
20212 ARG.
20213 UNIFY_ALLOW_INTEGER:
20214 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20215 case for more information.
20216 UNIFY_ALLOW_OUTER_LEVEL:
20217 This is the outermost level of a deduction. Used to determine validity
20218 of qualification conversions. A valid qualification conversion must
20219 have const qualified pointers leading up to the inner type which
20220 requires additional CV quals, except at the outer level, where const
20221 is not required [conv.qual]. It would be normal to set this flag in
20222 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20223 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20224 This is the outermost level of a deduction, and PARM can be more CV
20225 qualified at this point.
20226 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20227 This is the outermost level of a deduction, and PARM can be less CV
20228 qualified at this point. */
20230 static int
20233 {
20235 tree targ;
20236 tree tparm;
20238 tsubst_flags_t complain = (explain_p
20239 ? tf_warning_or_error
20242 /* I don't think this will do the right thing with respect to types.
20243 But the only case I've seen it in so far has been array bounds, where
20244 signedness is the only information lost, and I think that will be
20245 okay. */
20253 /* We can't deduce anything from this, but we might get all the
20254 template args from other function args. */
20260 /* If PARM uses template parameters, then we can't bail out here,
20261 even if ARG == PARM, since we won't record unifications for the
20262 template parameters. We might need them if we're trying to
20263 figure out which of two things is more specialized. */
20267 /* Handle init lists early, so the rest of the function can assume
20268 we're dealing with a type. */
20270 {
20275 /* Replace T with std::initializer_list<T> for deduction. */
20282 /* We can only deduce from an initializer list argument if the
20283 parameter is std::initializer_list or an array; otherwise this
20284 is a non-deduced context. */
20289 else
20290 {
20292 /* Deduction is defined in terms of a single type, so just punt
20293 on the (bizarre) std::initializer_list<T...>. */
20296 }
20299 {
20306 {
20310 /* It should only be possible to get here for a call. */
20312 elt_strict |= maybe_adjust_types_for_deduction
20315 }
20318 explain_p);
20319 }
20323 {
20324 /* Also deduce from the length of the initializer list. */
20331 }
20333 /* If the std::initializer_list<T> deduction worked, replace the
20334 deduced A with std::initializer_list<A>. */
20336 {
20341 }
20343 }
20345 /* If parm and arg aren't the same kind of thing (template, type, or
20346 expression), fail early. */
20350 /* Immediately reject some pairs that won't unify because of
20351 cv-qualification mismatches. */
20354 /* It is the elements of the array which hold the cv quals of an array
20355 type, and the elements might be template type parms. We'll check
20356 when we recurse. */
20358 /* We check the cv-qualifiers when unifying with template type
20359 parameters below. We want to allow ARG `const T' to unify with
20360 PARM `T' for example, when computing which of two templates
20361 is more specialized, for example. */
20375 {
20379 /* In a type which contains a nested-name-specifier, template
20380 argument values cannot be deduced for template parameters used
20381 within the nested-name-specifier. */
20393 /* The PARM is not one we're trying to unify. Just check
20394 to see if it matches ARG. */
20395 {
20400 else
20402 }
20409 /* Check for mixed types and values. */
20417 {
20420 {
20421 /* First try to match ARG directly. */
20423 explain_p);
20425 {
20426 /* Otherwise, look for a suitable base of ARG, as below. */
20433 }
20434 }
20435 /* ARG must be constructed from a template class or a template
20436 template parameter. */
20441 /* Deduce arguments T, i from TT<T> or TT<i>. */
20447 /* Fall through to deduce template name. */
20448 }
20452 {
20453 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20455 /* Simple cases: Value already set, does match or doesn't. */
20460 }
20461 else
20462 {
20463 /* If PARM is `const T' and ARG is only `int', we don't have
20464 a match unless we are allowing additional qualification.
20465 If ARG is `const int' and PARM is just `T' that's OK;
20466 that binds `const int' to `T'. */
20471 /* Consider the case where ARG is `const volatile int' and
20472 PARM is `const T'. Then, T should be `volatile int'. */
20473 arg = cp_build_qualified_type_real
20478 /* Simple cases: Value already set, does match or doesn't. */
20484 /* Make sure that ARG is not a variable-sized array. (Note
20485 that were talking about variable-sized arrays (like
20486 `int[n]'), rather than arrays of unknown size (like
20487 `int[]').) We'll get very confused by such a type since
20488 the bound of the array is not constant, and therefore
20489 not mangleable. Besides, such types are not allowed in
20490 ISO C++, so we can do as we please here. We do allow
20491 them for 'auto' deduction, since that isn't ABI-exposed. */
20495 /* Strip typedefs as in convert_template_argument. */
20497 }
20499 /* If ARG is a parameter pack or an expansion, we cannot unify
20500 against it unless PARM is also a parameter pack. */
20505 /* If the argument deduction results is a METHOD_TYPE,
20506 then there is a problem.
20507 METHOD_TYPE doesn't map to any real C++ type the result of
20508 the deduction can not be of that type. */
20522 {
20523 /* The PARM is not one we're trying to unify. Just check
20524 to see if it matches ARG. */
20530 }
20536 {
20541 }
20544 /* We deduce from array bounds in try_array_deduction. */
20548 {
20553 }
20555 /* [temp.deduct.type] If, in the declaration of a function template
20556 with a non-type template-parameter, the non-type
20557 template-parameter is used in an expression in the function
20558 parameter-list and, if the corresponding template-argument is
20559 deduced, the template-argument type shall match the type of the
20560 template-parameter exactly, except that a template-argument
20561 deduced from an array bound may be of any integral type.
20562 The non-type parameter might use already deduced type parameters. */
20565 {
20569 }
20572 /* Template-parameter dependent expression. Just accept it for now.
20573 It will later be processed in convert_template_argument. */
20574 ;
20579 /* Convert the ARG to the type of PARM; the deduced non-type
20580 template argument must exactly match the types of the
20581 corresponding parameter. */
20584 /* We haven't deduced the type of this parameter yet. Try again
20585 later. */
20587 else
20590 /* If ARG is a parameter pack or an expansion, we cannot unify
20591 against it unless PARM is also a parameter pack. */
20596 {
20599 }
20604 {
20605 /* A pointer-to-member constant can be unified only with
20606 another constant. */
20610 /* Just unify the class member. It would be useless (and possibly
20611 wrong, depending on the strict flags) to unify also
20612 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20613 arg refer to the same variable, even if through different
20614 classes. For instance:
20616 struct A { int x; };
20617 struct B : A { };
20619 Unification of &A::x and &B::x must succeed. */
20622 }
20625 {
20629 /* [temp.deduct.call]
20631 A can be another pointer or pointer to member type that can
20632 be converted to the deduced A via a qualification
20633 conversion (_conv.qual_).
20635 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20636 This will allow for additional cv-qualification of the
20637 pointed-to types if appropriate. */
20640 /* The derived-to-base conversion only persists through one
20641 level of pointers. */
20646 }
20678 /* We have already checked cv-qualification at the top of the
20679 function. */
20683 /* As far as unification is concerned, this wins. Later checks
20684 will invalidate it if necessary. */
20687 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20688 /* Type INTEGER_CST can come from ordinary constant template args. */
20700 {
20710 /* Check for pack expansions in the parameters. */
20712 {
20714 {
20716 /* We can unify against something with a trailing
20717 parameter pack. */
20719 else
20720 /* [temp.deduct.type]/9: If the template argument list of
20721 P contains a pack expansion that is not the last
20722 template argument, the entire template argument list
20723 is a non-deduced context. */
20725 }
20726 }
20728 /* If we don't have enough arguments to satisfy the parameters
20729 (not counting the pack expression at the end), or we have
20730 too many arguments for a parameter list that doesn't end in
20731 a pack expression, we can't unify. */
20737 /* Unify all of the parameters that precede the (optional)
20738 pack expression. */
20740 {
20745 }
20748 DEDUCE_EXACT,
20751 }
20759 {
20767 }
20772 {
20776 {
20777 /* First, we try to unify the PARM and ARG directly. */
20782 {
20783 /* Fallback to the special case allowed in
20784 [temp.deduct.call]:
20786 If P is a class, and P has the form
20787 template-id, then A can be a derived class of
20788 the deduced A. Likewise, if P is a pointer to
20789 a class of the form template-id, A can be a
20790 pointer to a derived class pointed to by the
20791 deduced A. */
20797 {
20798 /* Don't give the derived diagnostic if we're
20799 already dealing with the same template. */
20800 bool same_template
20806 }
20807 }
20808 }
20812 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20813 Then, we should unify `int' and `U'. */
20815 else
20816 /* There's no chance of unification succeeding. */
20821 }
20828 {
20831 tree a;
20837 /* CV qualifications for methods can never be deduced, they must
20838 match exactly. We need to check them explicitly here,
20839 because type_unification_real treats them as any other
20840 cv-qualified parameter. */
20842 && (!check_cv_quals_for_unify
20870 {
20882 }
20885 }
20888 /* Unify a pointer to member with a pointer to member function, which
20889 deduces the type of the member as a function type. */
20891 {
20892 /* Check top-level cv qualifiers */
20900 /* Determine the type of the function we are unifying against. */
20904 }
20923 /* Matched cases are handled by the ARG == PARM test above. */
20927 /* We might get a variable as a non-type template argument in parm if the
20928 corresponding parameter is type-dependent. Make any necessary
20929 adjustments based on whether arg is a reference. */
20933 {
20938 }
20939 /* Now use the normal expression code to check whether they match. */
20950 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
20951 or UNDERLYING_TYPE nodes. */
20955 /* Unification fails if we hit an error node. */
20960 {
20970 }
20971 /* FALLTHRU */
20974 /* An unresolved overload is a nondeduced context. */
20978 expr:
20979 /* We must be looking at an expression. This can happen with
20980 something like:
20982 template <int I>
20983 void foo(S<I>, S<I + 2>);
20985 This is a "nondeduced context":
20987 [deduct.type]
20989 The nondeduced contexts are:
20991 --A type that is a template-id in which one or more of
20992 the template-arguments is an expression that references
20993 a template-parameter.
20995 In these cases, we assume deduction succeeded, but don't
20996 actually infer any unifications. */
21001 else
21003 }
21004 }
21005 #undef RECUR_AND_CHECK_FAILURE
21006 \f
21007 /* Note that DECL can be defined in this translation unit, if
21008 required. */
21010 static void
21012 {
21013 tree clone;
21017 }
21019 /* Called if RESULT is explicitly instantiated, or is a member of an
21020 explicitly instantiated class. */
21022 void
21024 {
21027 /* If this entity has already been written out, it's too late to
21028 make any modifications. */
21032 /* For anonymous namespace we don't need to do anything. */
21034 {
21037 }
21040 /* The TREE_PUBLIC flag for function declarations will have been
21041 set correctly by tsubst. */
21044 /* This might have been set by an earlier implicit instantiation. */
21049 else
21050 {
21053 /* Always make artificials weak. */
21056 /* For WIN32 we also want to put explicit instantiations in
21057 linkonce sections. */
21060 }
21062 /* If EXTERN_P, then this function will not be emitted -- unless
21063 followed by an explicit instantiation, at which point its linkage
21064 will be adjusted. If !EXTERN_P, then this function will be
21065 emitted here. In neither circumstance do we want
21066 import_export_decl to adjust the linkage. */
21068 }
21070 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21071 important template arguments. If any are missing, we check whether
21072 they're important by using error_mark_node for substituting into any
21073 args that were used for partial ordering (the ones between ARGS and END)
21074 and seeing if it bubbles up. */
21076 static bool
21078 {
21083 {
21086 }
21088 {
21092 }
21094 }
21096 /* Given two function templates PAT1 and PAT2, return:
21098 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21099 -1 if PAT2 is more specialized than PAT1.
21100 0 if neither is more specialized.
21102 LEN indicates the number of parameters we should consider
21103 (defaulted parameters should not be considered).
21105 The 1998 std underspecified function template partial ordering, and
21106 DR214 addresses the issue. We take pairs of arguments, one from
21107 each of the templates, and deduce them against each other. One of
21108 the templates will be more specialized if all the *other*
21109 template's arguments deduce against its arguments and at least one
21110 of its arguments *does* *not* deduce against the other template's
21111 corresponding argument. Deduction is done as for class templates.
21112 The arguments used in deduction have reference and top level cv
21113 qualifiers removed. Iff both arguments were originally reference
21114 types *and* deduction succeeds in both directions, an lvalue reference
21115 wins against an rvalue reference and otherwise the template
21116 with the more cv-qualified argument wins for that pairing (if
21117 neither is more cv-qualified, they both are equal). Unlike regular
21118 deduction, after all the arguments have been deduced in this way,
21119 we do *not* verify the deduced template argument values can be
21120 substituted into non-deduced contexts.
21122 The logic can be a bit confusing here, because we look at deduce1 and
21123 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21124 can find template arguments for pat1 to make arg1 look like arg2, that
21125 means that arg2 is at least as specialized as arg1. */
21127 int
21129 {
21142 /* Remove the this parameter from non-static member functions. If
21143 one is a non-static member function and the other is not a static
21144 member function, remove the first parameter from that function
21145 also. This situation occurs for operator functions where we
21146 locate both a member function (with this pointer) and non-member
21147 operator (with explicit first operand). */
21149 {
21154 }
21156 {
21159 {
21160 len--;
21162 }
21163 }
21165 /* If only one is a conversion operator, they are unordered. */
21169 /* Consider the return type for a conversion function */
21171 {
21174 len++;
21175 }
21177 processing_template_decl++;
21183 /* Stop when an ellipsis is seen. */
21185 {
21196 {
21197 /* When both arguments are pack expansions, we need only
21198 unify the patterns themselves. */
21202 /* This is the last comparison we need to do. */
21204 }
21207 {
21211 }
21214 {
21218 }
21224 {
21230 /* Setup the parameter vector, which contains only ARG1. */
21233 /* Setup the argument vector, which contains the remaining
21234 arguments. */
21243 /* We cannot deduce in the other direction, because ARG1 is
21244 a pack expansion but ARG2 is not. */
21246 }
21248 {
21254 /* Setup the parameter vector, which contains only ARG1. */
21257 /* Setup the argument vector, which contains the remaining
21258 arguments. */
21267 /* We cannot deduce in the other direction, because ARG2 is
21268 a pack expansion but ARG1 is not.*/
21270 }
21272 else
21273 {
21274 /* The normal case, where neither argument is a pack
21275 expansion. */
21282 }
21284 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21285 arg2, then arg2 is not as specialized as arg1. */
21291 /* "If, for a given type, deduction succeeds in both directions
21292 (i.e., the types are identical after the transformations above)
21293 and both P and A were reference types (before being replaced with
21294 the type referred to above):
21295 - if the type from the argument template was an lvalue reference and
21296 the type from the parameter template was not, the argument type is
21297 considered to be more specialized than the other; otherwise,
21298 - if the type from the argument template is more cv-qualified
21299 than the type from the parameter template (as described above),
21300 the argument type is considered to be more specialized than the other;
21301 otherwise,
21302 - neither type is more specialized than the other." */
21305 {
21307 {
21310 else
21312 }
21314 {
21319 }
21320 }
21323 /* We've failed to deduce something in either direction.
21324 These must be unordered. */
21329 /* We have already processed all of the arguments in our
21330 handing of the pack expansion type. */
21335 }
21337 /* "In most cases, all template parameters must have values in order for
21338 deduction to succeed, but for partial ordering purposes a template
21339 parameter may remain without a value provided it is not used in the
21340 types being used for partial ordering."
21342 Thus, if we are missing any of the targs1 we need to substitute into
21343 origs1, then pat2 is not as specialized as pat1. This can happen when
21344 there is a nondeduced context. */
21350 processing_template_decl--;
21352 /* If both deductions succeed, the partial ordering selects the more
21353 constrained template. */
21355 {
21360 }
21362 /* All things being equal, if the next argument is a pack expansion
21363 for one function but not for the other, prefer the
21364 non-variadic function. FIXME this is bogus; see c++/41958. */
21368 {
21371 }
21377 else
21379 }
21381 /* Determine which of two partial specializations of TMPL is more
21382 specialized.
21384 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21385 to the first partial specialization. The TREE_PURPOSE is the
21386 innermost set of template parameters for the partial
21387 specialization. PAT2 is similar, but for the second template.
21389 Return 1 if the first partial specialization is more specialized;
21390 -1 if the second is more specialized; 0 if neither is more
21391 specialized.
21393 See [temp.class.order] for information about determining which of
21394 two templates is more specialized. */
21396 static int
21398 {
21399 tree targs;
21408 /* Just like what happens for functions, if we are ordering between
21409 different template specializations, we may encounter dependent
21410 types in the arguments, and we need our dependency check functions
21411 to behave correctly. */
21415 {
21418 }
21422 {
21425 }
21428 /* If both deductions succeed, the partial ordering selects the more
21429 constrained template. */
21433 /* In the case of a tie where at least one of the templates
21434 has a parameter pack at the end, the template with the most
21435 non-packed parameters wins. */
21437 && any_deductions
21440 {
21446 /* We don't count the pack expansion at the end. */
21456 }
21459 }
21461 /* Return the template arguments that will produce the function signature
21462 DECL from the function template FN, with the explicit template
21463 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21464 also match. Return NULL_TREE if no satisfactory arguments could be
21465 found. */
21467 static tree
21469 {
21473 tree decl_arg_types;
21476 tree arg;
21480 /* Never do unification on the 'this' parameter. */
21501 }
21503 /* Return the innermost template arguments that, when applied to a partial
21504 specialization SPEC_TMPL of TMPL, yield the ARGS.
21506 For example, suppose we have:
21508 template <class T, class U> struct S {};
21509 template <class T> struct S<T*, int> {};
21511 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21512 partial specialization and the ARGS will be {double*, int}. The resulting
21513 vector will be {double}, indicating that `T' is bound to `double'. */
21515 static tree
21517 {
21519 tree spec_args
21522 tree deduced_args;
21523 tree innermost_deduced_args;
21527 {
21531 innermost_deduced_args);
21532 }
21533 else
21537 again:
21546 {
21548 {
21554 }
21556 }
21560 {
21563 }
21565 /* Verify that nondeduced template arguments agree with the type
21566 obtained from argument deduction.
21568 For example:
21570 struct A { typedef int X; };
21571 template <class T, class U> struct C {};
21572 template <class T> struct C<T, typename T::X> {};
21574 Then with the instantiation `C<A, int>', we can deduce that
21575 `T' is `A' but unify () does not check whether `typename T::X'
21576 is `int'. */
21585 /* We only need to check the innermost arguments; the other
21586 arguments will always agree. */
21591 /* Now that we have bindings for all of the template arguments,
21592 ensure that the arguments deduced for the template template
21593 parameters have compatible template parameter lists. See the use
21594 of template_template_parm_bindings_ok_p in fn_type_unification
21595 for more information. */
21600 }
21602 // Compare two function templates T1 and T2 by deducing bindings
21603 // from one against the other. If both deductions succeed, compare
21604 // constraints to see which is more constrained.
21605 static int
21607 {
21612 {
21615 }
21618 {
21621 }
21623 // If both deductions succeed, then one may be more constrained.
21628 }
21630 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21631 Return the TREE_LIST node with the most specialized template, if
21632 any. If there is no most specialized template, the error_mark_node
21633 is returned.
21635 Note that this function does not look at, or modify, the
21636 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21637 returned is one of the elements of INSTANTIATIONS, callers may
21638 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21639 and retrieve it from the value returned. */
21641 tree
21643 {
21650 {
21655 {
21656 /* Equally specialized, move to next function. If there
21657 is no next function, nothing's most specialized. */
21662 }
21663 }
21666 /* Now verify that champ is better than everything earlier in the
21667 instantiation list. */
21670 {
21673 }
21674 }
21676 processing_template_decl--;
21682 }
21684 /* If DECL is a specialization of some template, return the most
21685 general such template. Otherwise, returns NULL_TREE.
21687 For example, given:
21689 template <class T> struct S { template <class U> void f(U); };
21691 if TMPL is `template <class U> void S<int>::f(U)' this will return
21692 the full template. This function will not trace past partial
21693 specializations, however. For example, given in addition:
21695 template <class T> struct S<T*> { template <class U> void f(U); };
21697 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21698 `template <class T> template <class U> S<T*>::f(U)'. */
21700 tree
21702 {
21704 {
21707 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21708 template friend, or a FIELD_DECL for a capture pack. */
21711 }
21713 /* Look for more and more general templates. */
21715 {
21716 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21717 (See cp-tree.h for details.) */
21726 /* Stop if we run into an explicitly specialized class template. */
21733 }
21736 }
21738 /* Return the most specialized of the template partial specializations
21739 which can produce TARGET, a specialization of some class or variable
21740 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21741 a TEMPLATE_DECL node corresponding to the partial specialization, while
21742 the TREE_PURPOSE is the set of template arguments that must be
21743 substituted into the template pattern in order to generate TARGET.
21745 If the choice of partial specialization is ambiguous, a diagnostic
21746 is issued, and the error_mark_node is returned. If there are no
21747 partial specializations matching TARGET, then NULL_TREE is
21748 returned, indicating that the primary template should be used. */
21750 static tree
21752 {
21754 tree t;
21755 tree champ;
21762 {
21766 }
21768 {
21771 }
21773 {
21777 }
21778 else
21783 /* For determining which partial specialization to use, only the
21784 innermost args are interesting. */
21786 {
21789 }
21792 {
21793 tree spec_args;
21797 {
21798 /* Substitute in the template args from the enclosing class. */
21802 }
21809 {
21813 /* Keep the candidate only if the constraints are satisfied,
21814 or if we're not compiling with concepts. */
21817 {
21820 }
21821 }
21822 }
21832 {
21835 ;
21836 else
21837 {
21839 {
21842 {
21845 }
21846 }
21848 }
21849 }
21853 {
21856 {
21859 }
21860 }
21863 {
21870 else
21874 {
21879 }
21882 }
21885 }
21887 /* Explicitly instantiate DECL. */
21889 void
21891 {
21896 /* An error occurred, for which grokdeclarator has already issued
21897 an appropriate message. */
21900 {
21903 }
21909 {
21910 /* There is an asymmetry here in the way VAR_DECLs and
21911 FUNCTION_DECLs are handled by grokdeclarator. In the case of
21912 the latter, the DECL we get back will be marked as a
21913 template instantiation, and the appropriate
21914 DECL_TEMPLATE_INFO will be set up. This does not happen for
21915 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
21916 should handle VAR_DECLs as it currently handles
21917 FUNCTION_DECLs. */
21919 {
21922 }
21925 {
21928 }
21930 {
21935 }
21936 }
21938 {
21941 }
21942 else
21945 /* Check for various error cases. Note that if the explicit
21946 instantiation is valid the RESULT will currently be marked as an
21947 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
21948 until we get here. */
21951 {
21952 /* DR 259 [temp.spec].
21954 Both an explicit instantiation and a declaration of an explicit
21955 specialization shall not appear in a program unless the explicit
21956 instantiation follows a declaration of the explicit specialization.
21958 For a given set of template parameters, if an explicit
21959 instantiation of a template appears after a declaration of an
21960 explicit specialization for that template, the explicit
21961 instantiation has no effect. */
21963 }
21965 {
21966 /* [temp.spec]
21968 No program shall explicitly instantiate any template more
21969 than once.
21971 We check DECL_NOT_REALLY_EXTERN so as not to complain when
21972 the first instantiation was `extern' and the second is not,
21973 and EXTERN_P for the opposite case. */
21976 /* If an "extern" explicit instantiation follows an ordinary
21977 explicit instantiation, the template is instantiated. */
21980 }
21982 {
21985 }
21987 {
21990 }
21993 ;
21995 {
21998 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22001 }
22002 else
22010 }
22012 static void
22014 {
22020 {
22023 }
22024 }
22026 /* Called from do_type_instantiation through binding_table_foreach to
22027 do recursive instantiation for the type bound in ENTRY. */
22028 static void
22030 {
22036 }
22038 /* Called from do_type_instantiation to instantiate a member
22039 (a member function or a static member variable) of an
22040 explicitly instantiated class template. */
22041 static void
22043 {
22048 }
22050 /* Perform an explicit instantiation of template class T. STORAGE, if
22051 non-null, is the RID for extern, inline or static. COMPLAIN is
22052 nonzero if this is called from the parser, zero if called recursively,
22053 since the standard is unclear (as detailed below). */
22055 void
22057 {
22067 {
22068 tree tmpl =
22072 else
22075 }
22080 {
22083 t);
22085 }
22088 {
22090 {
22092 {
22095 "ISO C++ 1998 forbids the use of %<extern%> on "
22097 }
22098 else
22100 "ISO C++ forbids the use of %qE"
22102 }
22110 else
22111 {
22113 storage);
22115 }
22116 }
22119 {
22120 /* DR 259 [temp.spec].
22122 Both an explicit instantiation and a declaration of an explicit
22123 specialization shall not appear in a program unless the explicit
22124 instantiation follows a declaration of the explicit specialization.
22126 For a given set of template parameters, if an explicit
22127 instantiation of a template appears after a declaration of an
22128 explicit specialization for that template, the explicit
22129 instantiation has no effect. */
22131 }
22133 {
22134 /* [temp.spec]
22136 No program shall explicitly instantiate any template more
22137 than once.
22139 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22140 instantiation was `extern'. If EXTERN_P then the second is.
22141 These cases are OK. */
22148 /* If we've already instantiated the template, just return now. */
22151 }
22159 {
22160 tree tmp;
22162 /* In contrast to implicit instantiation, where only the
22163 declarations, and not the definitions, of members are
22164 instantiated, we have here:
22166 [temp.explicit]
22168 The explicit instantiation of a class template specialization
22169 implies the instantiation of all of its members not
22170 previously explicitly specialized in the translation unit
22171 containing the explicit instantiation.
22173 Of course, we can't instantiate member template classes, since
22174 we don't have any arguments for them. Note that the standard
22175 is unclear on whether the instantiation of the members are
22176 *explicit* instantiations or not. However, the most natural
22177 interpretation is that it should be an explicit instantiation. */
22193 }
22194 }
22196 /* Given a function DECL, which is a specialization of TMPL, modify
22197 DECL to be a re-instantiation of TMPL with the same template
22198 arguments. TMPL should be the template into which tsubst'ing
22199 should occur for DECL, not the most general template.
22201 One reason for doing this is a scenario like this:
22203 template <class T>
22204 void f(const T&, int i);
22206 void g() { f(3, 7); }
22208 template <class T>
22209 void f(const T& t, const int i) { }
22211 Note that when the template is first instantiated, with
22212 instantiate_template, the resulting DECL will have no name for the
22213 first parameter, and the wrong type for the second. So, when we go
22214 to instantiate the DECL, we regenerate it. */
22216 static void
22218 {
22219 /* The arguments used to instantiate DECL, from the most general
22220 template. */
22221 tree code_pattern;
22225 /* Make sure that we can see identifiers, and compute access
22226 correctly. */
22230 {
22231 tree decl_parm;
22232 tree pattern_parm;
22233 tree specs;
22247 specs);
22249 /* Merge parameter declarations. */
22252 pattern_parm
22256 {
22257 tree parm_type;
22258 tree attributes;
22263 NULL_TREE);
22269 {
22272 }
22275 }
22276 /* Merge any parameters that match with the function parameter
22277 pack. */
22279 {
22281 tree expanded_types;
22282 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22283 the parameters in this function parameter pack. */
22288 {
22289 tree parm_type;
22290 tree attributes;
22293 /* Rename the parameter to include the index. */
22302 {
22305 }
22307 }
22308 }
22309 /* Merge additional specifiers from the CODE_PATTERN. */
22313 }
22315 {
22323 }
22324 else
22328 }
22330 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22331 substituted to get DECL. */
22333 tree
22335 {
22338 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22339 for the instantiation. This is not always the most general
22340 template. Consider, for example:
22342 template <class T>
22343 struct S { template <class U> void f();
22344 template <> void f<int>(); };
22346 and an instantiation of S<double>::f<int>. We want TD to be the
22347 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22349 more general template. */
22351 /* We must also deal with friend templates. Given:
22353 template <class T> struct S {
22354 template <class U> friend void f() {};
22355 };
22357 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22358 so far as the language is concerned, but that's still
22359 where we get the pattern for the instantiation from. On
22360 other hand, if the definition comes outside the class, say:
22362 template <class T> struct S {
22363 template <class U> friend void f();
22364 };
22365 template <class U> friend void f() {}
22367 we don't need to look any further. That's what the check for
22368 DECL_INITIAL is for. */
22372 {
22373 /* The present template, TD, should not be a definition. If it
22374 were a definition, we should be using it! Note that we
22375 cannot restructure the loop to just keep going until we find
22376 a template with a definition, since that might go too far if
22377 a specialization was declared, but not defined. */
22379 /* Fetch the more general template. */
22381 }
22384 }
22386 /* Returns true if we need to instantiate this template instance even if we
22387 know we aren't going to emit it. */
22389 bool
22391 {
22392 /* We always instantiate inline functions so that we can inline them. An
22393 explicit instantiation declaration prohibits implicit instantiation of
22394 non-inline functions. With high levels of optimization, we would
22395 normally inline non-inline functions -- but we're not allowed to do
22396 that for "extern template" functions. Therefore, we check
22397 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22401 /* And we need to instantiate static data members so that
22402 their initializers are available in integral constant
22403 expressions. */
22406 }
22408 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22409 instantiate it now, modifying TREE_TYPE (fn). */
22411 void
22413 {
22416 /* Don't instantiate a noexcept-specification from template context. */
22431 {
22435 {
22450 }
22451 else
22455 }
22458 {
22461 else
22463 }
22464 }
22466 /* Produce the definition of D, a _DECL generated from a template. If
22467 DEFER_OK is true, then we don't have to actually do the
22468 instantiation now; we just have to do it sometime. Normally it is
22469 an error if this is an explicit instantiation but D is undefined.
22470 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22471 instantiated class template. */
22473 tree
22475 {
22477 tree gen_args;
22478 tree args;
22479 tree td;
22480 tree code_pattern;
22481 tree spec;
22482 tree gen_tmpl;
22490 /* This function should only be used to instantiate templates for
22491 functions and static member variables. */
22494 /* A concept is never instantiated. */
22497 /* Variables are never deferred; if instantiation is required, they
22498 are instantiated right away. That allows for better code in the
22499 case that an expression refers to the value of the variable --
22500 if the variable has a constant value the referring expression can
22501 take advantage of that fact. */
22505 /* Don't instantiate cloned functions. Instead, instantiate the
22506 functions they cloned. */
22514 /* D has already been instantiated or explicitly specialized, so
22515 there's nothing for us to do here.
22517 It might seem reasonable to check whether or not D is an explicit
22518 instantiation, and, if so, stop here. But when an explicit
22519 instantiation is deferred until the end of the compilation,
22520 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22521 the instantiation. */
22524 /* Check to see whether we know that this template will be
22525 instantiated in some other file, as with "extern template"
22526 extension. */
22529 /* In general, we do not instantiate such templates. */
22537 /* We should already have the extra args. */
22540 /* And what's in the hash table should match D. */
22544 /* This needs to happen before any tsubsting. */
22550 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22551 for the instantiation. */
22556 {
22557 /* Look up an explicit specialization, if any. */
22561 {
22564 }
22565 }
22569 /* We should never be trying to instantiate a member of a class
22570 template or partial specialization. */
22575 /* In the case of a friend template whose definition is provided
22576 outside the class, we may have too many arguments. Drop the
22577 ones we don't need. The same is true for specializations. */
22578 args = get_innermost_template_args
22582 {
22588 }
22589 else
22590 {
22595 else
22597 }
22599 /* We may be in the middle of deferred access check. Disable it now. */
22602 /* Unless an explicit instantiation directive has already determined
22603 the linkage of D, remember that a definition is available for
22604 this entity. */
22614 /* If D is a member of an explicitly instantiated class template,
22615 and no definition is available, treat it like an implicit
22616 instantiation. */
22619 {
22620 /* Leave linkage flags alone on instantiations with anonymous
22621 visibility. */
22623 {
22626 }
22628 }
22630 /* Defer all other templates, unless we have been explicitly
22631 forbidden from doing so. */
22633 template. */
22634 ! pattern_defined
22635 /* If it's OK to postpone instantiation, do so. */
22636 || defer_ok
22637 /* If this is a static data member that will be defined
22638 elsewhere, we don't want to instantiate the entire data
22639 member, but we do want to instantiate the initializer so that
22640 we can substitute that elsewhere. */
22642 /* Handle here a deleted function too, avoid generating
22643 its body (c++/61080). */
22645 {
22646 /* The definition of the static data member is now required so
22647 we must substitute the initializer. */
22651 {
22652 tree ns;
22653 tree init;
22662 args,
22665 /* If instantiating the initializer involved instantiating this
22666 again, don't call cp_finish_decl twice. */
22668 {
22669 /* Make sure the initializer is still constant, in case of
22670 circular dependency (template/instantiate6.C). */
22671 const_init
22675 LOOKUP_ONLYCONVERTING);
22676 }
22680 }
22682 /* We restore the source position here because it's used by
22683 add_pending_template. */
22689 /* [temp.explicit]
22691 The definition of a non-exported function template, a
22692 non-exported member function template, or a non-exported
22693 member function or static data member of a class template
22694 shall be present in every translation unit in which it is
22695 explicitly instantiated. */
22699 /* If we're in unevaluated context, we just wanted to get the
22700 constant value; this isn't an odr use, so don't queue
22701 a full instantiation. */
22704 /* ??? Historically, we have instantiated inline functions, even
22705 when marked as "extern template". */
22709 }
22710 /* Tell the repository that D is available in this translation unit
22711 -- and see if it is supposed to be instantiated here. */
22713 {
22714 /* In a PCH file, despite the fact that the repository hasn't
22715 requested instantiation in the PCH it is still possible that
22716 an instantiation will be required in a file that includes the
22717 PCH. */
22720 /* Instantiate inline functions so that the inliner can do its
22721 job, even though we'll not be emitting a copy of this
22722 function. */
22725 }
22728 tree fn_context;
22739 else
22740 {
22744 }
22746 /* Mark D as instantiated so that recursive calls to
22747 instantiate_decl do not try to instantiate it again. */
22750 /* Regenerate the declaration in case the template has been modified
22751 by a subsequent redeclaration. */
22754 /* We already set the file and line above. Reset them now in case
22755 they changed as a result of calling regenerate_decl_from_template. */
22759 {
22760 tree init;
22763 /* Clear out DECL_RTL; whatever was there before may not be right
22764 since we've reset the type of the declaration. */
22768 /* The initializer is placed in DECL_INITIAL by
22769 regenerate_decl_from_template so we don't need to
22770 push/pop_access_scope again here. Pull it out so that
22771 cp_finish_decl can process it. */
22776 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22777 initializer. That function will defer actual emission until
22778 we have a chance to determine linkage. */
22781 /* Enter the scope of D so that access-checking works correctly. */
22794 }
22798 {
22800 tree tmpl_parm;
22801 tree spec_parm;
22805 /* Save away the current list, in case we are instantiating one
22806 template from within the body of another. */
22809 /* Set up the list of local specializations. */
22812 /* Set up context. */
22816 else
22817 {
22819 {
22820 /* When instantiating a lambda's templated function
22821 operator, we need to push the non-lambda class scope
22822 of the lambda itself so that the nested function
22823 stack is sufficiently correct to deal with this
22824 capture. */
22826 do
22831 }
22833 }
22835 /* Some typedefs referenced from within the template code need to be
22836 access checked at template instantiation time, i.e now. These
22837 types were added to the template at parsing time. Let's get those
22838 and perform the access checks then. */
22840 args);
22842 /* Create substitution entries for the parameters. */
22846 {
22850 }
22852 {
22854 {
22857 }
22858 else
22859 {
22860 /* Register the (value) argument pack as a specialization of
22861 TMPL_PARM, then move on. */
22864 }
22865 }
22868 /* Substitute into the body of the function. */
22872 else
22873 {
22878 /* Set the current input_location to the end of the function
22879 so that finish_function knows where we are. */
22880 input_location
22883 /* Remember if we saw an infinite loop in the template. */
22884 current_function_infinite_loop
22886 }
22888 /* We don't need the local specializations any more. */
22892 /* Finish the function. */
22896 else
22897 {
22900 }
22906 }
22908 /* We're not deferring instantiation any more. */
22913 else
22919 out:
22928 }
22930 /* Run through the list of templates that we wish we could
22931 instantiate, and instantiate any we can. RETRIES is the
22932 number of times we retry pending template instantiation. */
22934 void
22936 {
22940 /* Instantiating templates may trigger vtable generation. This in turn
22941 may require further template instantiations. We place a limit here
22942 to avoid infinite loop. */
22944 {
22948 "template instantiation depth exceeds maximum of %d"
22949 " instantiating %q+D, possibly from virtual table generation"
22953 /* Pretend that we defined it. */
22956 }
22958 do
22959 {
22964 {
22969 {
22970 tree fn;
22973 {
22977 fn;
22985 }
22988 }
22989 else
22990 {
22993 {
22994 instantiation
23000 }
23004 }
23007 /* If INSTANTIATION has been instantiated, then we don't
23008 need to consider it again in the future. */
23010 else
23011 {
23014 }
23017 }
23019 }
23023 }
23025 /* Substitute ARGVEC into T, which is a list of initializers for
23026 either base class or a non-static data member. The TREE_PURPOSEs
23027 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23028 instantiate_decl. */
23030 static tree
23032 {
23036 {
23037 tree decl;
23038 tree init;
23044 {
23045 tree expr;
23046 tree arg;
23048 /* Expand the base class expansion type into separate base
23049 classes. */
23051 tf_warning_or_error,
23052 NULL_TREE);
23056 /* We'll be building separate TREE_LISTs of arguments for
23057 each base. */
23063 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23064 expand each argument in the TREE_VALUE of t. */
23071 /* VOID_TYPE_NODE is used to indicate
23072 value-initialization. */
23073 {
23076 }
23077 else
23078 {
23079 /* Substitute parameter packs into each argument in the
23080 TREE_LIST. */
23083 {
23084 tree expanded_exprs;
23086 /* Expand the argument. */
23088 expanded_exprs
23090 tf_warning_or_error,
23091 NULL_TREE);
23095 /* Prepend each of the expanded expressions to the
23096 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23098 {
23103 }
23104 }
23107 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23108 since we built them backwards. */
23110 {
23113 }
23114 }
23115 }
23118 {
23120 {
23124 }
23125 else
23126 {
23127 tree tmp;
23142 /* If we had an initializer but it instantiated to nothing,
23143 value-initialize the object. This will only occur when
23144 the initializer was a pack expansion where the parameter
23145 packs used in that expansion were of length zero. */
23148 }
23151 {
23155 }
23156 }
23157 }
23159 }
23161 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23163 static void
23165 {
23170 else
23172 }
23174 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23175 is the instantiation (which should have been created with
23176 start_enum) and ARGS are the template arguments to use. */
23178 static void
23180 {
23181 tree e;
23187 {
23188 tree value;
23189 tree decl;
23192 /* Note that in a template enum, the TREE_VALUE is the
23193 CONST_DECL, not the corresponding INTEGER_CST. */
23198 /* Give this enumeration constant the correct access. */
23201 /* Actually build the enumerator itself. Here we're assuming that
23202 enumerators can't have dependent attributes. */
23205 }
23215 }
23217 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23218 its type -- but without substituting the innermost set of template
23219 arguments. So, innermost set of template parameters will appear in
23220 the type. */
23222 tree
23224 {
23225 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23227 }
23229 /* Return truthvalue if we're processing a template different from
23230 the last one involved in diagnostics. */
23231 bool
23233 {
23235 }
23237 /* Remember current template involved in diagnostics. */
23238 void
23240 {
23242 }
23246 {
23248 }
23250 /* Return TRUE if current_function_decl is being instantiated, false
23251 otherwise. */
23253 bool
23255 {
23258 }
23260 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23261 type. Return zero for ok, nonzero for disallowed. Issue error and
23262 warning messages under control of COMPLAIN. */
23264 static int
23266 {
23281 /* A bound template template parm could later be instantiated to have a valid
23282 nontype parm type via an alias template. */
23288 {
23291 else
23293 type);
23294 }
23296 }
23298 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23299 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23301 static bool
23303 {
23304 tree scope;
23306 /* [temp.dep.type]
23308 A type is dependent if it is:
23310 -- a template parameter. Template template parameters are types
23311 for us (since TYPE_P holds true for them) so we handle
23312 them here. */
23316 /* -- a qualified-id with a nested-name-specifier which contains a
23317 class-name that names a dependent type or whose unqualified-id
23318 names a dependent type. */
23322 /* An alias template specialization can be dependent even if the
23323 resulting type is not. */
23327 /* -- a cv-qualified type where the cv-unqualified type is
23328 dependent.
23329 No code is necessary for this bullet; the code below handles
23330 cv-qualified types, and we don't want to strip aliases with
23331 TYPE_MAIN_VARIANT because of DR 1558. */
23332 /* -- a compound type constructed from any dependent type. */
23342 {
23343 tree arg_type;
23348 arg_type;
23353 }
23354 /* -- an array type constructed from any dependent type or whose
23355 size is specified by a constant expression that is
23356 value-dependent.
23358 We checked for type- and value-dependence of the bounds in
23359 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23361 {
23366 }
23368 /* -- a template-id in which either the template name is a template
23369 parameter ... */
23372 /* ... or any of the template arguments is a dependent type or
23373 an expression that is type-dependent or value-dependent. */
23375 && (any_dependent_template_arguments_p
23379 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23380 dependent; if the argument of the `typeof' expression is not
23381 type-dependent, then it should already been have resolved. */
23387 /* A template argument pack is dependent if any of its packed
23388 arguments are. */
23390 {
23396 }
23398 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23399 be template parameters. */
23406 /* The standard does not specifically mention types that are local
23407 to template functions or local classes, but they should be
23408 considered dependent too. For example:
23410 template <int I> void f() {
23411 enum E { a = I };
23412 S<sizeof (E)> s;
23413 }
23415 The size of `E' cannot be known until the value of `I' has been
23416 determined. Therefore, `E' must be considered dependent. */
23420 /* Don't use type_dependent_expression_p here, as it can lead
23421 to infinite recursion trying to determine whether a lambda
23422 nested in a lambda is dependent (c++/47687). */
23426 && (any_dependent_template_arguments_p
23430 /* Other types are non-dependent. */
23432 }
23434 /* Returns TRUE if TYPE is dependent, in the sense of
23435 [temp.dep.type]. Note that a NULL type is considered dependent. */
23437 bool
23439 {
23440 /* If there are no template parameters in scope, then there can't be
23441 any dependent types. */
23443 {
23444 /* If we are not processing a template, then nobody should be
23445 providing us with a dependent type. */
23449 }
23451 /* If the type is NULL, we have not computed a type for the entity
23452 in question; in that case, the type is dependent. */
23456 /* Erroneous types can be considered non-dependent. */
23460 /* If we have not already computed the appropriate value for TYPE,
23461 do so now. */
23463 {
23466 }
23469 }
23471 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23472 lookup. In other words, a dependent type that is not the current
23473 instantiation. */
23475 bool
23477 {
23480 }
23482 /* T is a SCOPE_REF; return whether we need to consider it
23483 instantiation-dependent so that we can check access at instantiation
23484 time even though we know which member it resolves to. */
23486 static bool
23488 {
23494 else
23496 }
23498 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23499 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23500 expression. */
23502 /* Note that this predicate is not appropriate for general expressions;
23503 only constant expressions (that satisfy potential_constant_expression)
23504 can be tested for value dependence. */
23506 bool
23508 {
23512 /* A name declared with a dependent type. */
23517 {
23519 /* A dependent member function of the current instantiation. */
23523 /* A dependent member function of the current instantiation. */
23530 /* A name that has not been looked up -- must be dependent. */
23534 /* A non-type template parm. */
23538 /* A non-type template parm. */
23544 /* A constant with literal type and is initialized
23545 with an expression that is value-dependent.
23547 Note that a non-dependent parenthesized initializer will have
23548 already been replaced with its constant value, so if we see
23549 a TREE_LIST it must be dependent. */
23553 /* cp_finish_decl doesn't fold reference initializers. */
23565 /* These expressions are value-dependent if the type to which
23566 the cast occurs is dependent or the expression being casted
23567 is value-dependent. */
23568 {
23574 /* A functional cast has a list of operands. */
23577 {
23578 /* If there are no operands, it must be an expression such
23579 as "int()". This should not happen for aggregate types
23580 because it would form non-constant expressions. */
23585 }
23591 }
23596 /* FALLTHRU */
23599 /* A `sizeof' expression is value-dependent if the operand is
23600 type-dependent or is a pack expansion. */
23609 /* An 'encode' expression is value-dependent if the operand is
23610 type-dependent. */
23619 /* All instantiation-dependent expressions should also be considered
23620 value-dependent. */
23628 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23629 is value-dependent. */
23630 {
23639 }
23642 {
23646 }
23657 {
23661 }
23664 /* Treat all requires-expressions as value-dependent so
23665 we don't try to fold them. */
23672 {
23679 {
23681 /* In a call to a constexpr member function, look through the
23682 implicit ADDR_EXPR on the object argument so that it doesn't
23683 cause the call to be considered value-dependent. We also
23684 look through it in potential_constant_expression. */
23691 }
23693 }
23696 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23697 type-dependent. */
23702 {
23704 tree val;
23711 }
23714 /* Treat a GNU statement expression as dependent to avoid crashing
23715 under instantiate_non_dependent_expr; it can't be constant. */
23719 /* A constant expression is value-dependent if any subexpression is
23720 value-dependent. */
23722 {
23729 {
23733 {
23736 /* In some cases, some of the operands may be missing.l
23737 (For example, in the case of PREDECREMENT_EXPR, the
23738 amount to increment by may be missing.) That doesn't
23739 make the expression dependent. */
23742 }
23743 }
23747 }
23749 }
23751 /* The expression is not value-dependent. */
23753 }
23755 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23756 [temp.dep.expr]. Note that an expression with no type is
23757 considered dependent. Other parts of the compiler arrange for an
23758 expression with type-dependent subexpressions to have no type, so
23759 this function doesn't have to be fully recursive. */
23761 bool
23763 {
23770 /* An unresolved name is always dependent. */
23776 /* A fold expression is type-dependent. */
23783 /* Some expression forms are never type-dependent. */
23797 /* The types of these expressions depends only on the type to which
23798 the cast occurs. */
23807 /* The types of these expressions depends only on the type created
23808 by the expression. */
23811 {
23812 /* For NEW_EXPR tree nodes created inside a template, either
23813 the object type itself or a TREE_LIST may appear as the
23814 operand 1. */
23817 /* This is an array type. We need to check array dimensions
23818 as well. */
23820 || value_dependent_expression_p
23822 else
23824 }
23827 {
23831 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23832 contains an identifier associated by name lookup with one or more
23833 declarations declared with a dependent type, or...a
23834 nested-name-specifier or qualified-id that names a member of an
23835 unknown specialization. */
23838 }
23848 {
23849 tree elt;
23853 {
23856 }
23858 }
23860 /* A static data member of the current instantiation with incomplete
23861 array type is type-dependent, as the definition and specializations
23862 can have different bounds. */
23869 /* An array of unknown bound depending on a variadic parameter, eg:
23871 template<typename... Args>
23872 void foo (Args... args)
23873 {
23874 int arr[] = { args... };
23875 }
23877 template<int... vals>
23878 void bar ()
23879 {
23880 int arr[] = { vals... };
23881 }
23883 If the array has no length and has an initializer, it must be that
23884 we couldn't determine its length in cp_complete_array_type because
23885 it is dependent. */
23893 /* A function or variable template-id is type-dependent if it has any
23894 dependent template arguments. Note that we only consider the innermost
23895 template arguments here, since those are the ones that come from the
23896 template-id; the template arguments for the enclosing class do not make it
23897 type-dependent, they only make a member function value-dependent. */
23902 && (any_dependent_template_arguments_p
23906 /* Always dependent, on the number of arguments if nothing else. */
23911 {
23916 {
23922 }
23923 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
23928 {
23933 }
23936 {
23943 }
23949 {
23953 }
23955 }
23959 /* Dependent type attributes might not have made it from the decl to
23960 the type yet. */
23966 }
23968 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
23969 type-dependent if the expression refers to a member of the current
23970 instantiation and the type of the referenced member is dependent, or the
23971 class member access expression refers to a member of an unknown
23972 specialization.
23974 This function returns true if the OBJECT in such a class member access
23975 expression is of an unknown specialization. */
23977 bool
23979 {
23980 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
23981 dependent. */
23986 }
23988 /* walk_tree callback function for instantiation_dependent_expression_p,
23989 below. Returns non-zero if a dependent subexpression is found. */
23991 static tree
23994 {
23996 {
23997 /* We don't have to worry about decltype currently because decltype
23998 of an instantiation-dependent expr is a dependent type. This
23999 might change depending on the resolution of DR 1172. */
24002 }
24005 {
24006 /* Don't treat an argument list as dependent just because it has no
24007 TREE_TYPE. */
24015 /* Handle expressions with type operands. */
24020 {
24025 {
24028 else
24029 {
24032 }
24033 }
24035 }
24039 /* In a template, finish_class_member_access_expr creates a
24040 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24041 type-dependent, so that we can check access control at
24042 instantiation time (PR 42277). See also Core issue 1273. */
24049 else
24052 /* Treat statement-expressions as dependent. */
24056 /* Treat requires-expressions as dependent. */
24061 /* Treat calls to function concepts as dependent. */
24067 /* And variable concepts. */
24074 }
24078 else
24080 }
24082 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24083 sense defined by the ABI:
24085 "An expression is instantiation-dependent if it is type-dependent
24086 or value-dependent, or it has a subexpression that is type-dependent
24087 or value-dependent."
24089 Except don't actually check value-dependence for unevaluated expressions,
24090 because in sizeof(i) we don't care about the value of i. Checking
24091 type-dependence will in turn check value-dependence of array bounds/template
24092 arguments as needed. */
24094 bool
24096 {
24097 tree result;
24108 }
24110 /* As above, but also check value-dependence of the expression as a whole. */
24112 bool
24114 {
24117 }
24119 /* Like type_dependent_expression_p, but it also works while not processing
24120 a template definition, i.e. during substitution or mangling. */
24122 bool
24124 {
24130 }
24132 /* Returns TRUE if ARGS contains a type-dependent expression. */
24134 bool
24136 {
24138 tree arg;
24141 {
24144 }
24146 }
24148 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24149 expressions) contains any type-dependent expressions. */
24151 bool
24153 {
24159 }
24161 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24162 expressions) contains any value-dependent expressions. */
24164 bool
24166 {
24172 }
24174 /* Returns TRUE if the ARG (a template argument) is dependent. */
24176 bool
24178 {
24182 /* Assume a template argument that was wrongly written by the user
24183 is dependent. This is consistent with what
24184 any_dependent_template_arguments_p [that calls this function]
24185 does. */
24195 {
24198 /* A member template of a dependent class is not necessarily
24199 type-dependent, but it is a dependent template argument because it
24200 will be a member of an unknown specialization to that template. */
24203 }
24205 {
24209 {
24212 }
24215 }
24218 else
24221 }
24223 /* Returns true if ARGS (a collection of template arguments) contains
24224 any types that require structural equality testing. */
24226 bool
24228 {
24238 {
24241 {
24247 {
24248 /* Look inside the argument pack. */
24251 }
24254 {
24267 }
24268 }
24269 }
24272 }
24274 /* Returns true if ARGS (a collection of template arguments) contains
24275 any dependent arguments. */
24277 bool
24279 {
24289 {
24294 }
24297 }
24299 /* Returns TRUE if the template TMPL is type-dependent. */
24301 bool
24303 {
24305 {
24307 {
24311 }
24313 }
24315 /* Template template parameters are dependent. */
24319 /* So are names that have not been looked up. */
24323 }
24325 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24327 bool
24329 {
24332 }
24334 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24335 are dependent. */
24337 bool
24339 {
24346 {
24368 {
24372 }
24376 {
24380 {
24385 }
24386 }
24387 }
24390 }
24392 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24393 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24394 no such TYPE can be found. Note that this function peers inside
24395 uninstantiated templates and therefore should be used only in
24396 extremely limited situations. ONLY_CURRENT_P restricts this
24397 peering to the currently open classes hierarchy (which is required
24398 when comparing types). */
24400 tree
24402 {
24403 tree scope;
24404 tree name;
24405 tree decl;
24407 tree pushed_scope;
24408 tree result;
24413 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24414 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24415 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24416 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24417 identifier of the TYPENAME_TYPE anymore.
24418 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24419 TYPENAME_TYPE instead, we avoid messing up with a possible
24420 typedef variant case. */
24423 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24424 it first before we can figure out what NAME refers to. */
24426 {
24428 /* Given a class template A with a dependent base with nested type C,
24429 typedef typename A::C::C C will land us here, as trying to resolve
24430 the initial A::C leads to the local C typedef, which leads back to
24431 A::C::C. So we break the recursion now. */
24433 else
24435 }
24436 /* If we don't know what SCOPE refers to, then we cannot resolve the
24437 TYPENAME_TYPE. */
24440 /* If this is a typedef, we don't want to look inside (c++/11987). */
24443 /* If SCOPE isn't the template itself, it will not have a valid
24444 TYPE_FIELDS list. */
24446 /* scope is either the template itself or a compatible instantiation
24447 like X<T>, so look up the name in the original template. */
24449 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24451 /* If scope has no fields, it can't be a current instantiation. Check this
24452 before currently_open_class to avoid infinite recursion (71515). */
24455 /* If the SCOPE is not the current instantiation, there's no reason
24456 to look inside it. */
24459 /* Enter the SCOPE so that name lookup will be resolved as if we
24460 were in the class definition. In particular, SCOPE will no
24461 longer be considered a dependent type. */
24463 /* Look up the declaration. */
24465 tf_warning_or_error);
24469 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24470 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24475 {
24479 }
24482 {
24483 tree tmpl;
24484 tree args;
24485 /* Obtain the template and the arguments. */
24488 /* Instantiate the template. */
24494 }
24496 /* Leave the SCOPE. */
24500 /* If we failed to resolve it, return the original typename. */
24504 /* If lookup found a typename type, resolve that too. */
24506 {
24507 /* Ill-formed programs can cause infinite recursion here, so we
24508 must catch that. */
24512 }
24514 /* Qualify the resulting type. */
24520 }
24522 /* EXPR is an expression which is not type-dependent. Return a proxy
24523 for EXPR that can be used to compute the types of larger
24524 expressions containing EXPR. */
24526 tree
24528 {
24529 tree inner_expr;
24531 /* When checking, try to get a constant value for all non-dependent
24532 expressions in order to expose bugs in *_dependent_expression_p
24533 and constexpr. This can affect code generation, see PR70704, so
24534 only do this for -fchecking=2. */
24537 /* Don't do this during nsdmi parsing as it can lead to
24538 unexpected recursive instantiations. */
24540 /* Don't do this during concept expansion either and for
24541 the same reason. */
24545 /* Preserve OVERLOADs; the functions must be available to resolve
24546 types. */
24557 /* There is no need to return a proxy for a variable. */
24560 /* Preserve string constants; conversions from string constants to
24561 "char *" are allowed, even though normally a "const char *"
24562 cannot be used to initialize a "char *". */
24565 /* Preserve void and arithmetic constants, as an optimization -- there is no
24566 reason to create a new node. */
24571 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24572 There is at least one place where we want to know that a
24573 particular expression is a throw-expression: when checking a ?:
24574 expression, there are special rules if the second or third
24575 argument is a throw-expression. */
24579 /* Don't wrap an initializer list, we need to be able to look inside. */
24583 /* Don't wrap a dummy object, we need to be able to test for it. */
24602 /* If the type is unknown, it can't really be non-dependent */
24605 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24607 }
24609 /* ARGS is a vector of expressions as arguments to a function call.
24610 Replace the arguments with equivalent non-dependent expressions.
24611 This modifies ARGS in place. */
24613 void
24615 {
24617 tree arg;
24620 {
24624 }
24625 }
24627 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24628 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24629 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24631 static tree
24633 {
24647 }
24649 tree
24651 {
24653 }
24655 tree
24657 {
24659 }
24661 /* Return a C++17 deduction placeholder for class template TMPL. */
24663 tree
24665 {
24669 }
24671 /* Make a "constrained auto" type-specifier. This is an
24672 auto type with constraints that must be associated after
24673 deduction. The constraint is formed from the given
24674 CONC and its optional sequence of arguments, which are
24675 non-null if written as partial-concept-id. */
24677 tree
24679 {
24682 /* Build the constraint. */
24684 tree expr;
24687 else
24693 /* Our canonical type depends on the constraint. */
24696 /* Attach the constraint to the type declaration. */
24699 }
24701 /* Given type ARG, return std::initializer_list<ARG>. */
24703 static tree
24705 {
24706 tree std_init_list = namespace_binding
24708 tree argvec;
24710 {
24714 }
24719 }
24721 /* Replace auto in TYPE with std::initializer_list<auto>. */
24723 static tree
24725 {
24732 }
24734 /* Hash traits for hashing possibly constrained 'auto'
24735 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24738 {
24741 };
24743 /* Hash the 'auto' T. */
24745 inline hashval_t
24747 {
24749 /* Matching constrained-type-specifiers denote the same template
24750 parameter, so hash the constraint. */
24752 else
24753 /* But unconstrained autos are all separate, so just hash the pointer. */
24755 }
24757 /* Compare two 'auto's. */
24761 {
24768 /* Two unconstrained autos are distinct. */
24773 }
24775 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24776 constrained) auto, add it to the vector. */
24778 static int
24780 {
24783 {
24784 /* All the autos were built with index 0; fix that up now. */
24788 /* If this is a repeated constrained-type-specifier, use the index we
24789 chose before. */
24791 else
24792 {
24793 /* Otherwise this is new, so use the current count. */
24796 }
24798 }
24800 /* Always keep walking. */
24802 }
24804 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24805 says they can appear anywhere in the type. */
24807 static tree
24809 {
24818 {
24823 }
24826 }
24828 /* The stem for deduction guide names. */
24831 /* Return the name for a deduction guide for class template TMPL. */
24833 tree
24835 {
24846 }
24848 /* True if NAME is the name of a deduction guide. */
24850 bool
24852 {
24856 }
24858 /* True if FN is a deduction guide. */
24860 bool
24862 {
24867 }
24869 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24871 bool
24873 {
24880 }
24882 /* True if FN is a guide generated from a constructor template. */
24884 bool
24886 {
24891 {
24894 }
24896 }
24898 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
24899 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
24900 template parameter types. Note that the handling of template template
24901 parameters relies on current_template_parms being set appropriately for the
24902 new template. */
24904 static tree
24907 {
24910 tree newtype;
24913 {
24920 }
24921 else
24925 tree newdecl
24930 tree newidx;
24933 {
24941 {
24946 // First create a copy (ttargs) of tsubst_args with an
24947 // additional level for the template template parameter's own
24948 // template parameters (ttparms).
24949 tree ttparms = (INNERMOST_TEMPLATE_PARMS
24957 // Substitute ttargs into ttparms to fix references to
24958 // other template parameters.
24960 complain);
24961 // Now substitute again with args based on tparms, to reduce
24962 // the level of the ttparms.
24965 complain);
24966 // Finally, tack the adjusted parms onto tparms.
24968 current_template_parms);
24970 }
24971 }
24972 else
24973 {
24975 tree newconst
24985 }
24990 }
24992 /* Returns a C++17 class deduction guide template based on the constructor
24993 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
24994 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
24996 static tree
24998 {
25002 location_t loc;
25005 {
25009 {
25012 }
25013 else
25023 }
25024 else
25025 {
25029 tree fn_tmpl;
25031 {
25034 }
25035 else
25039 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25040 fully specialized args for the enclosing class. Strip those off, as
25041 the deduction guide won't have those template parameters. */
25044 /* Discard the 'this' parameter. */
25052 {
25055 /* For a member template constructor, we need to flatten the two
25056 template parameter lists into one, and then adjust the function
25057 signature accordingly. This gets...complicated. */
25061 /* For a member template we should have two levels of parms/args, one
25062 for the class and one for the constructor. We stripped
25063 specialized args for further enclosing classes above. */
25067 /* Template args for translating references to the two-level template
25068 parameters into references to the one-level template parameters we
25069 are creating. */
25074 /* Template parms for the constructor template. */
25077 /* Template parms for the class template. */
25081 /* Template parms for the deduction guide start as a copy of the
25082 template parms for the class. We set current_template_parms for
25083 lookup_template_class_1. */
25089 /* Now we need to rewrite the constructor parms to append them to the
25090 class parms. */
25092 {
25107 }
25109 /* Now we have a final set of template parms to substitute into the
25110 function signature. */
25120 }
25121 }
25124 {
25125 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25129 }
25133 FUNCTION_DECL,
25150 }
25152 /* Deduce template arguments for the class template placeholder PTYPE for
25153 template TMPL based on the initializer INIT, and return the resulting
25154 type. */
25156 static tree
25158 tsubst_flags_t complain)
25159 {
25161 {
25162 /* We should have handled this in the caller. */
25168 }
25180 else
25193 {
25196 }
25200 // FIXME cache artificial deduction guides
25202 {
25208 }
25211 {
25214 }
25216 {
25220 }
25222 /* Prune explicit deduction guides in copy-initialization context. */
25225 {
25231 {
25234 {
25238 }
25241 {
25243 " of %qT, as it has no non-explicit deduction guides or "
25246 }
25247 }
25248 }
25252 tf_decltype);
25255 {
25262 }
25268 }
25270 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25271 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25273 tree
25275 {
25277 tf_warning_or_error,
25278 adc_unspecified);
25279 }
25281 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25282 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25283 The CONTEXT determines the context in which auto deduction is performed
25284 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25285 OUTER_TARGS are used during template argument deduction
25286 (context == adc_unify) to properly substitute the result, and is ignored
25287 in other contexts.
25289 For partial-concept-ids, extra args may be appended to the list of deduced
25290 template arguments prior to determining constraint satisfaction. */
25292 tree
25296 {
25297 tree targs;
25304 /* Defining a subset of type-dependent expressions that we can deduce
25305 from ahead of time isn't worth the trouble. */
25309 /* C++17 class template argument deduction. */
25313 /* Nothing we can do with this, even in deduction context. */
25316 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25317 with either a new invented type template parameter U or, if the
25318 initializer is a braced-init-list (8.5.4), with
25319 std::initializer_list<U>. */
25321 {
25326 else
25327 {
25329 {
25333 "for deduction to %<std::initializer_list%>, use copy-"
25335 }
25337 }
25338 }
25349 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25350 and initializer has array type, deduce cv-qualified array type. */
25352 complain);
25354 {
25363 {
25367 }
25368 }
25369 else
25370 {
25372 tree tparms;
25376 else
25377 {
25381 }
25388 {
25390 /* Try again at instantiation time. */
25394 /* If type is error_mark_node a diagnostic must have been
25395 emitted by now. Also, having a mention to '<type error>'
25396 in the diagnostic is not really useful to the user. */
25397 {
25401 else
25406 }
25408 }
25409 }
25411 /* Check any placeholder constraints against the deduced type. */
25414 {
25415 /* Use the deduced type to check the associated constraints. If we
25416 have a partial-concept-id, rebuild the argument list so that
25417 we check using the extra arguments. */
25421 {
25424 }
25425 else
25428 {
25430 {
25432 {
25450 }
25452 }
25454 }
25455 }
25461 }
25463 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25464 result. */
25466 tree
25468 {
25470 {
25476 /* In an abbreviated function template we didn't know we were dealing
25477 with a function template when we saw the auto return type, so update
25478 it to have the correct level. */
25480 }
25482 }
25484 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25485 'decltype(auto)' or a deduced class template. */
25487 bool
25489 {
25495 else
25497 }
25499 /* for_each_template_parm callback for type_uses_auto. */
25501 int
25503 {
25505 }
25507 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25508 a use of `auto'. Returns NULL_TREE otherwise. */
25510 tree
25512 {
25516 {
25517 /* The Concepts TS allows multiple autos in one type-specifier; just
25518 return the first one we find, do_auto_deduction will collect all of
25519 them. */
25523 else
25525 }
25526 else
25528 }
25530 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
25531 'decltype(auto)' or a concept. */
25533 bool
25535 {
25537 }
25539 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
25540 a concept identifier) iff TYPE contains a use of a generic type. Returns
25541 NULL_TREE otherwise. */
25543 tree
25545 {
25547 }
25550 /* For a given template T, return the vector of typedefs referenced
25551 in T for which access check is needed at T instantiation time.
25552 T is either a FUNCTION_DECL or a RECORD_TYPE.
25553 Those typedefs were added to T by the function
25554 append_type_to_template_for_access_check. */
25558 {
25559 tree ti;
25570 {
25575 }
25578 }
25580 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25581 tied to T. That list of typedefs will be access checked at
25582 T instantiation time.
25583 T is either a FUNCTION_DECL or a RECORD_TYPE.
25584 TYPE_DECL is a TYPE_DECL node representing a typedef.
25585 SCOPE is the scope through which TYPE_DECL is accessed.
25586 LOCATION is the location of the usage point of TYPE_DECL.
25588 This function is a subroutine of
25589 append_type_to_template_for_access_check. */
25591 static void
25593 tree type_decl,
25594 tree scope,
25595 location_t location)
25596 {
25597 qualified_typedef_usage_t typedef_usage;
25598 tree ti;
25605 && type_decl
25619 }
25621 /* Append TYPE_DECL to the template TEMPL.
25622 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25623 At TEMPL instanciation time, TYPE_DECL will be checked to see
25624 if it can be accessed through SCOPE.
25625 LOCATION is the location of the usage point of TYPE_DECL.
25627 e.g. consider the following code snippet:
25629 class C
25630 {
25631 typedef int myint;
25632 };
25634 template<class U> struct S
25635 {
25636 C::myint mi; // <-- usage point of the typedef C::myint
25637 };
25639 S<char> s;
25641 At S<char> instantiation time, we need to check the access of C::myint
25642 In other words, we need to check the access of the myint typedef through
25643 the C scope. For that purpose, this function will add the myint typedef
25644 and the scope C through which its being accessed to a list of typedefs
25645 tied to the template S. That list will be walked at template instantiation
25646 time and access check performed on each typedefs it contains.
25647 Note that this particular code snippet should yield an error because
25648 myint is private to C. */
25650 void
25652 tree type_decl,
25653 tree scope,
25654 location_t location)
25655 {
25661 /* Make sure we don't append the type to the template twice. */
25668 }
25670 /* Convert the generic type parameters in PARM that match the types given in the
25671 range [START_IDX, END_IDX) from the current_template_parms into generic type
25672 packs. */
25674 tree
25676 {
25687 {
25688 /* Create a distinct parameter pack type from the current parm and add it
25689 to the replacement args to tsubst below into the generic function
25690 parameter. */
25705 }
25711 /* If there are more levels then build up the replacement with the outer
25712 template parms. */
25716 replacement);
25719 }
25721 /* Entries in the decl_constraint hash table. */
25723 {
25724 tree decl;
25725 tree ci;
25726 };
25728 /* Hashing function and equality for constraint entries. */
25730 {
25732 {
25734 }
25737 {
25739 }
25740 };
25742 /* A mapping from declarations to constraint information. Note that
25743 both templates and their underlying declarations are mapped to the
25744 same constraint information.
25746 FIXME: This is defined in pt.c because garbage collection
25747 code is not being generated for constraint.cc. */
25751 /* Returns the template constraints of declaration T. If T is not
25752 constrained, return NULL_TREE. Note that T must be non-null. */
25754 tree
25756 {
25767 else
25769 }
25771 /* Associate the given constraint information CI with the declaration
25772 T. If T is a template, then the constraints are associated with
25773 its underlying declaration. Don't build associations if CI is
25774 NULL_TREE. */
25776 void
25778 {
25790 }
25792 /* Remove the associated constraints of the declaration T. */
25794 void
25796 {
25805 }
25807 /* Memoized satisfaction results for declarations. This
25808 maps the pair (constraint_info, arguments) to the result computed
25809 by constraints_satisfied_p. */
25812 {
25813 tree ci;
25814 tree args;
25815 tree result;
25816 };
25818 /* Hashing function and equality for constraint entries. */
25821 {
25823 {
25826 }
25829 {
25831 }
25832 };
25834 /* Memoized satisfaction results for concept checks. */
25837 {
25838 tree tmpl;
25839 tree args;
25840 tree result;
25841 };
25843 /* Hashing function and equality for constraint entries. */
25846 {
25848 {
25850 }
25853 {
25858 }
25859 };
25864 /* Search for a memoized satisfaction result. Returns one of the
25865 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25867 tree
25869 {
25874 else
25876 }
25878 /* Memoize the result of a satisfication test. Returns the saved result. */
25880 tree
25882 {
25889 }
25891 /* Search for a memoized satisfaction result for a concept. */
25893 tree
25895 {
25900 else
25902 }
25904 /* Memoize the result of a concept check. Returns the saved result. */
25906 tree
25908 {
25915 }
25919 /* Returns a prior concept specialization. This returns the substituted
25920 and normalized constraints defined by the concept. */
25922 tree
25924 {
25929 else
25931 }
25933 /* Save a concept expansion for later. */
25935 tree
25937 {
25944 }
25946 static hashval_t
25948 {
25957 }
25959 /* Compare the constraints of two subsumption entries. The LEFT1 and
25960 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
25961 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
25963 static bool
25965 {
25973 }
25975 /* Key/value pair for learning and memoizing subsumption results. This
25976 associates a pair of check constraints (including arguments) with
25977 a boolean value indicating the result. */
25980 {
25981 tree t1;
25982 tree t2;
25984 };
25986 /* Hashing function and equality for constraint entries. */
25989 {
25991 {
25993 }
25996 {
26001 }
26002 };
26006 /* Search for a previously cached subsumption result. */
26010 {
26015 else
26017 }
26019 /* Save a subsumption result. */
26021 bool
26023 {
26030 }
26032 /* Set up the hash table for constraint association. */
26034 void
26036 {
26045 }
26047 /* Set up the hash tables for template instantiations. */
26049 void
26051 {
26054 }
26056 /* Print stats about the template hash tables for -fstats. */
26058 void
26060 {
26069 }