| blob | 1289d64f071deedd75e091567ffd528a7b263139 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2016 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);
212 location_t);
220 /* Make the current scope suitable for access checking when we are
221 processing T. T can be FUNCTION_DECL for instantiated function
222 template, VAR_DECL for static member variable, or TYPE_DECL for
223 alias template (needed by instantiate_decl). */
225 static void
227 {
235 else
239 {
240 saved_access_scope = tree_cons
243 }
244 }
246 /* Restore the scope set up by push_access_scope. T is the node we
247 are processing. */
249 static void
251 {
253 {
256 }
260 else
262 }
264 /* Do any processing required when DECL (a member template
265 declaration) is finished. Returns the TEMPLATE_DECL corresponding
266 to DECL, unless it is a specialization, in which case the DECL
267 itself is returned. */
269 tree
271 {
278 {
279 tree type;
287 {
291 }
293 }
297 {
299 {
302 }
303 else
305 }
306 else
310 }
312 /* Create a template info node. */
314 tree
316 {
321 }
323 /* Return the template info node corresponding to T, whatever T is. */
325 tree
327 {
349 }
351 /* Returns the template nesting level of the indicated class TYPE.
353 For example, in:
354 template <class T>
355 struct A
356 {
357 template <class U>
358 struct B {};
359 };
361 A<T>::B<U> has depth two, while A<T> has depth one.
362 Both A<T>::B<int> and A<int>::B<U> have depth one, if
363 they are instantiations, not specializations.
365 This function is guaranteed to return 0 if passed NULL_TREE so
366 that, for example, `template_class_depth (current_class_type)' is
367 always safe. */
369 int
371 {
375 {
386 else
388 }
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Returns true if processing DECL needs us to push template parms. */
396 static bool
398 {
404 }
406 /* Subroutine of maybe_begin_member_template_processing.
407 Push the template parms in PARMS, starting from LEVELS steps into the
408 chain, and ending at the beginning, since template parms are listed
409 innermost first. */
411 static void
413 {
421 current_template_parms
427 NULL);
429 {
438 {
445 /* Push the CONST_DECL. */
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to call pushdecl_with_scope on the
653 TEMPLATE_DECL for S2. */
659 /* Add a dummy parameter level while we process the parameter list. */
660 current_template_parms
663 current_template_parms);
664 }
666 /* This routine is called when a specialization is declared. If it is
667 invalid to declare a specialization here, an error is reported and
668 false is returned, otherwise this routine will return true. */
670 static bool
672 {
675 /* [temp.expl.spec]
677 An explicit specialization shall be declared in the namespace of
678 which the template is a member, or, for member templates, in the
679 namespace of which the enclosing class or enclosing class
680 template is a member. An explicit specialization of a member
681 function, member class or static data member of a class template
682 shall be declared in the namespace of which the class template
683 is a member. */
685 {
688 }
690 /* [temp.expl.spec]
692 In an explicit specialization declaration for a member of a class
693 template or a member template that appears in namespace scope,
694 the member template and some of its enclosing class templates may
695 remain unspecialized, except that the declaration shall not
696 explicitly specialize a class member template if its enclosing
697 class templates are not explicitly specialized as well. */
699 {
702 }
705 }
707 /* We've just seen template <>. */
709 bool
711 {
715 }
717 /* Called at then end of processing a declaration preceded by
718 template<>. */
720 void
722 {
725 }
727 /* Any template <>'s that we have seen thus far are not referring to a
728 function specialization. */
730 void
732 {
735 }
737 /* We've just seen a template header. If SPECIALIZATION is nonzero,
738 it was of the form template <>. */
740 static void
742 {
744 template_header_count++;
745 }
747 /* We're beginning an explicit instantiation. */
749 void
751 {
754 }
757 void
759 {
762 }
764 /* An explicit specialization or partial specialization of TMPL is being
765 declared. Check that the namespace in which the specialization is
766 occurring is permissible. Returns false iff it is invalid to
767 specialize TMPL in the current namespace. */
769 static bool
771 {
774 /* [tmpl.expl.spec]
776 An explicit specialization shall be declared in the namespace of
777 which the template is a member, or, for member templates, in the
778 namespace of which the enclosing class or enclosing class
779 template is a member. An explicit specialization of a member
780 function, member class or static data member of a class template
781 shall be declared in the namespace of which the class template is
782 a member. */
785 {
788 }
790 /* Same or super-using 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.
901 /* We only need a separate type node for storing the definition of this
902 partial specialization; uses of S<T*> are unconstrained, so all are
903 equivalent. So keep TYPE_CANONICAL the same. */
906 // Build the corresponding type decl.
912 }
915 }
917 /* The TYPE is being declared. If it is a template type, that means it
918 is a partial specialization. Do appropriate error-checking. */
920 tree
922 {
923 tree context;
928 /* A lambda that appears in specialization context is not itself a
929 specialization. */
934 {
938 }
943 {
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 {
1603 /* Dup decl failed, but this is a new definition. Set the
1604 line number so any errors match this new
1605 definition. */
1609 }
1610 }
1614 /* A specialization must be declared in the same namespace as the
1615 template it is specializing. */
1621 {
1630 /* If TMPL is a forward declaration of a template function, keep a list
1631 of all specializations in case we need to reassign them to a friend
1632 template later in tsubst_friend_function.
1634 Also keep a list of all variable template instantiations so that
1635 process_partial_specialization can check whether a later partial
1636 specialization would have used it. */
1639 }
1642 }
1644 /* Returns true iff two spec_entry nodes are equivalent. */
1648 bool
1650 {
1657 /* tmpl could be a FIELD_DECL for a capture pack. */
1661 {
1662 /* Partial specializations of a variable template can be distinguished by
1663 constraints. */
1667 }
1671 }
1673 /* Returns a hash for a template TMPL and template arguments ARGS. */
1675 static hashval_t
1677 {
1680 }
1682 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1683 ignoring SPEC. */
1685 hashval_t
1687 {
1689 }
1691 /* Recursively calculate a hash value for a template argument ARG, for use
1692 in the hash tables of template specializations. */
1694 hashval_t
1696 {
1708 /* We can get one of these when re-hashing a previous entry in the middle
1709 of substituting into a pack expansion. Just look through it. */
1718 {
1726 {
1731 }
1753 {
1757 {
1760 }
1762 }
1766 {
1769 }
1780 val = iterative_hash_template_arg
1792 val);
1794 val);
1803 /* A lambda can't appear in a template arg, but don't crash on
1804 erroneous input. */
1816 /* Now hash operands as usual. */
1821 }
1824 {
1827 {
1828 // We want an alias specialization that survived strip_typedefs
1829 // to hash differently from its TYPE_CANONICAL, to avoid hash
1830 // collisions that compare as different in template_args_equal.
1831 // These could be dependent specializations that strip_typedefs
1832 // left alone, or untouched specializations because
1833 // coerce_template_parms returns the unconverted template
1834 // arguments if it sees incomplete argument packs.
1837 }
1840 val);
1843 /* Otherwise just compare the types during lookup. */
1852 {
1857 }
1858 }
1861 }
1863 /* Unregister the specialization SPEC as a specialization of TMPL.
1864 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1865 if the SPEC was listed as a specialization of TMPL.
1867 Note that SPEC has been ggc_freed, so we can't look inside it. */
1869 bool
1871 {
1873 spec_entry elt;
1881 {
1886 }
1889 }
1891 /* Like register_specialization, but for local declarations. We are
1892 registering SPEC, an instantiation of TMPL. */
1894 void
1896 {
1898 }
1900 /* TYPE is a class type. Returns true if TYPE is an explicitly
1901 specialized class. */
1903 bool
1905 {
1909 }
1911 /* Print the list of functions at FNS, going through all the overloads
1912 for each element of the list. Alternatively, FNS can not be a
1913 TREE_LIST, in which case it will be printed together with all the
1914 overloads.
1916 MORE and *STR should respectively be FALSE and NULL when the function
1917 is called from the outside. They are used internally on recursive
1918 calls. print_candidates manages the two parameters and leaves NULL
1919 in *STR when it ends. */
1921 static void
1923 {
1929 {
1933 }
1934 else
1935 {
1938 {
1939 /* Pick the prefix string. */
1941 {
1945 }
1949 }
1952 }
1955 {
1958 }
1959 }
1961 /* Print the list of candidate FNS in an error message. FNS can also
1962 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1964 void
1966 {
1970 }
1972 /* Get a (possibly) constrained template declaration for the
1973 purpose of ordering candidates. */
1974 static tree
1976 {
1982 }
1984 /* Among candidates having the same signature, return the
1985 most constrained or NULL_TREE if there is no best candidate.
1986 If the signatures of candidates vary (e.g., template
1987 specialization vs. member function), then there can be no
1988 most constrained.
1990 Note that we don't compare constraints on the functions
1991 themselves, but rather those of their templates. */
1992 static tree
1994 {
1995 // Try to find the best candidate in a first pass.
1998 {
2005 }
2007 // Verify that the champ is better than previous candidates.
2012 }
2015 }
2018 /* Returns the template (one of the functions given by TEMPLATE_ID)
2019 which can be specialized to match the indicated DECL with the
2020 explicit template args given in TEMPLATE_ID. The DECL may be
2021 NULL_TREE if none is available. In that case, the functions in
2022 TEMPLATE_ID are non-members.
2024 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2025 specialization of a member template.
2027 The TEMPLATE_COUNT is the number of references to qualifying
2028 template classes that appeared in the name of the function. See
2029 check_explicit_specialization for a more accurate description.
2031 TSK indicates what kind of template declaration (if any) is being
2032 declared. TSK_TEMPLATE indicates that the declaration given by
2033 DECL, though a FUNCTION_DECL, has template parameters, and is
2034 therefore a template function.
2036 The template args (those explicitly specified and those deduced)
2037 are output in a newly created vector *TARGS_OUT.
2039 If it is impossible to determine the result, an error message is
2040 issued. The error_mark_node is returned to indicate failure. */
2042 static tree
2044 tree decl,
2048 tmpl_spec_kind tsk)
2049 {
2050 tree fns;
2051 tree targs;
2052 tree explicit_targs;
2055 /* A TREE_LIST of templates of which DECL may be a specialization.
2056 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2057 corresponding TREE_PURPOSE is the set of template arguments that,
2058 when used to instantiate the template, would produce a function
2059 with the signature of DECL. */
2069 /* We shouldn't be specializing a member template of an
2070 unspecialized class template; we already gave an error in
2071 check_specialization_scope, now avoid crashing. */
2074 {
2077 }
2085 /* Check for baselinks. */
2090 {
2093 }
2095 {
2098 }
2100 /* Count the number of template headers specified for this
2101 specialization. */
2111 {
2114 tf_warning_or_error,
2118 }
2120 {
2124 {
2125 tree decl_arg_types;
2126 tree fn_arg_types;
2127 tree insttype;
2129 /* In case of explicit specialization, we need to check if
2130 the number of template headers appearing in the specialization
2131 is correct. This is usually done in check_explicit_specialization,
2132 but the check done there cannot be exhaustive when specializing
2133 member functions. Consider the following code:
2135 template <> void A<int>::f(int);
2136 template <> template <> void A<int>::f(int);
2138 Assuming that A<int> is not itself an explicit specialization
2139 already, the first line specializes "f" which is a non-template
2140 member function, whilst the second line specializes "f" which
2141 is a template member function. So both lines are syntactically
2142 correct, and check_explicit_specialization does not reject
2143 them.
2145 Here, we can do better, as we are matching the specialization
2146 against the declarations. We count the number of template
2147 headers, and we check if they match TEMPLATE_COUNT + 1
2148 (TEMPLATE_COUNT is the number of qualifying template classes,
2149 plus there must be another header for the member template
2150 itself).
2152 Notice that if header_count is zero, this is not a
2153 specialization but rather a template instantiation, so there
2154 is no check we can perform here. */
2158 /* Check that the number of template arguments at the
2159 innermost level for DECL is the same as for FN. */
2167 /* DECL might be a specialization of FN. */
2171 /* For a non-static member function, we need to make sure
2172 that the const qualification is the same. Since
2173 get_bindings does not try to merge the "this" parameter,
2174 we must do the comparison explicitly. */
2180 /* Skip the "this" parameter and, for constructors of
2181 classes with virtual bases, the VTT parameter. A
2182 full specialization of a constructor will have a VTT
2183 parameter, but a template never will. */
2184 decl_arg_types
2186 fn_arg_types
2189 /* Function templates cannot be specializations; there are
2190 no partial specializations of functions. Therefore, if
2191 the type of DECL does not match FN, there is no
2192 match.
2194 Note that it should never be the case that we have both
2195 candidates added here, and for regular member functions
2196 below. */
2198 {
2202 }
2204 /* See whether this function might be a specialization of this
2205 template. Suppress access control because we might be trying
2206 to make this specialization a friend, and we have already done
2207 access control for the declaration of the specialization. */
2213 /* We cannot deduce template arguments that when used to
2214 specialize TMPL will produce DECL. */
2217 /* Remove, from the set of candidates, all those functions
2218 whose constraints are not satisfied. */
2222 // Then, try to form the new function type.
2226 fn_arg_types
2231 /* Save this template, and the arguments deduced. */
2233 }
2235 /* FN is an ordinary member function, and we need a
2236 specialization of a member template. */
2237 ;
2239 /* We can get IDENTIFIER_NODEs here in certain erroneous
2240 cases. */
2241 ;
2243 /* This is just an ordinary non-member function. Nothing can
2244 be a specialization of that. */
2245 ;
2247 /* Cannot specialize functions that are created implicitly. */
2248 ;
2249 else
2250 {
2251 tree decl_arg_types;
2253 /* This is an ordinary member function. However, since
2254 we're here, we can assume its enclosing class is a
2255 template class. For example,
2257 template <typename T> struct S { void f(); };
2258 template <> void S<int>::f() {}
2260 Here, S<int>::f is a non-template, but S<int> is a
2261 template class. If FN has the same type as DECL, we
2262 might be in business. */
2265 /* Its enclosing class is an explicit specialization
2266 of a template class. This is not a candidate. */
2271 /* The return types differ. */
2274 /* Adjust the type of DECL in case FN is a static member. */
2281 decl_arg_types))
2284 // If the deduced arguments do not satisfy the constraints,
2285 // this is not a candidate.
2289 // Add the candidate.
2291 }
2292 }
2295 {
2296 /* We have:
2298 [temp.expl.spec]
2300 It is possible for a specialization with a given function
2301 signature to be instantiated from more than one function
2302 template. In such cases, explicit specification of the
2303 template arguments must be used to uniquely identify the
2304 function template specialization being specialized.
2306 Note that here, there's no suggestion that we're supposed to
2307 determine which of the candidate templates is most
2308 specialized. However, we, also have:
2310 [temp.func.order]
2312 Partial ordering of overloaded function template
2313 declarations is used in the following contexts to select
2314 the function template to which a function template
2315 specialization refers:
2317 -- when an explicit specialization refers to a function
2318 template.
2320 So, we do use the partial ordering rules, at least for now.
2321 This extension can only serve to make invalid programs valid,
2322 so it's safe. And, there is strong anecdotal evidence that
2323 the committee intended the partial ordering rules to apply;
2324 the EDG front end has that behavior, and John Spicer claims
2325 that the committee simply forgot to delete the wording in
2326 [temp.expl.spec]. */
2329 {
2332 }
2333 }
2335 // Concepts allows multiple declarations of member functions
2336 // with the same signature. Like above, we need to rely on
2337 // on the partial ordering of those candidates to determine which
2338 // is the best.
2340 {
2342 {
2345 }
2346 }
2349 {
2356 else
2359 }
2363 {
2369 }
2371 /* We have one, and exactly one, match. */
2373 {
2377 // Propagate the candidate's constraints to the declaration.
2380 /* DECL is a re-declaration or partial instantiation of a template
2381 function. */
2384 /* It was a specialization of an ordinary member function in a
2385 template class. */
2387 }
2389 /* It was a specialization of a template. */
2392 {
2397 }
2398 else
2401 }
2403 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2404 but with the default argument values filled in from those in the
2405 TMPL_TYPES. */
2407 static tree
2409 tree tmpl_types)
2410 {
2411 tree new_spec_types;
2419 /* Substitute into the rest of the list. */
2420 new_spec_types =
2424 /* Add the default argument for this parameter. */
2427 new_spec_types);
2428 }
2430 /* DECL is an explicit specialization. Replicate default arguments
2431 from the template it specializes. (That way, code like:
2433 template <class T> void f(T = 3);
2434 template <> void f(double);
2435 void g () { f (); }
2437 works, as required.) An alternative approach would be to look up
2438 the correct default arguments at the call-site, but this approach
2439 is consistent with how implicit instantiations are handled. */
2441 static void
2443 {
2444 tree tmpl;
2445 tree spec_types;
2446 tree tmpl_types;
2447 tree new_spec_types;
2448 tree old_type;
2449 tree new_type;
2450 tree t;
2455 /* See if there's anything we need to do. */
2468 {
2469 /* Remove the this pointer, but remember the object's type for
2470 CV quals. */
2476 {
2477 /* DECL may contain more parameters than TMPL due to the extra
2478 in-charge parameter in constructors and destructors. */
2481 }
2483 {
2486 }
2487 }
2489 /* Compute the merged default arguments. */
2490 new_spec_types =
2493 /* Compute the new FUNCTION_TYPE. */
2495 {
2499 new_spec_types);
2502 /* Put the in-charge parameter back. */
2505 new_spec_types);
2509 new_spec_types);
2510 }
2511 else
2513 new_spec_types);
2523 }
2525 /* Return the number of template headers we expect to see for a definition
2526 or specialization of CTYPE or one of its non-template members. */
2528 int
2530 {
2534 {
2535 /* You're supposed to have one `template <...>' for every
2536 template class, but you don't need one for a full
2537 specialization. For example:
2539 template <class T> struct S{};
2540 template <> struct S<int> { void f(); };
2541 void S<int>::f () {}
2543 is correct; there shouldn't be a `template <>' for the
2544 definition of `S<int>::f'. */
2546 /* If CTYPE does not have template information of any
2547 kind, then it is not a template, nor is it nested
2548 within a template. */
2556 }
2559 }
2561 /* Do a simple sanity check on the template headers that precede the
2562 variable declaration DECL. */
2564 void
2566 {
2571 {
2574 "variable templates only available with "
2577 // Namespace-scope variable templates should have a template header.
2579 }
2581 {
2588 "members of an explicitly specialized class are defined "
2590 }
2591 }
2593 /* Check to see if the function just declared, as indicated in
2594 DECLARATOR, and in DECL, is a specialization of a function
2595 template. We may also discover that the declaration is an explicit
2596 instantiation at this point.
2598 Returns DECL, or an equivalent declaration that should be used
2599 instead if all goes well. Issues an error message if something is
2600 amiss. Returns error_mark_node if the error is not easily
2601 recoverable.
2603 FLAGS is a bitmask consisting of the following flags:
2605 2: The function has a definition.
2606 4: The function is a friend.
2608 The TEMPLATE_COUNT is the number of references to qualifying
2609 template classes that appeared in the name of the function. For
2610 example, in
2612 template <class T> struct S { void f(); };
2613 void S<int>::f();
2615 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2616 classes are not counted in the TEMPLATE_COUNT, so that in
2618 template <class T> struct S {};
2619 template <> struct S<int> { void f(); }
2620 template <> void S<int>::f();
2622 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2623 invalid; there should be no template <>.)
2625 If the function is a specialization, it is marked as such via
2626 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2627 is set up correctly, and it is added to the list of specializations
2628 for that template. */
2630 tree
2632 tree decl,
2635 {
2644 tmpl_spec_kind tsk;
2647 {
2650 else
2652 }
2653 else
2657 {
2660 {
2663 }
2665 {
2667 /* This could be something like:
2669 template <class T> void f(T);
2670 class S { friend void f<>(int); } */
2672 else
2673 {
2674 /* This case handles bogus declarations like template <>
2675 template <class T> void f<int>(); */
2678 declarator);
2680 }
2681 }
2685 /* The error has already been reported in
2686 check_specialization_scope. */
2692 /* Fall through. */
2705 decl);
2708 else
2712 /* Fall through. */
2718 /* In cases like template<> constexpr bool v = true;
2719 We'll give an error in check_template_variable. */
2725 else
2731 {
2732 /* This case handles bogus declarations like template <>
2733 template <class T> void f<int>(); */
2737 declarator);
2739 {
2740 /* Partial specialization of variable template. */
2744 }
2748 else
2752 ok:;
2753 }
2756 /* This is a specialization of a member template, without
2757 specialization the containing class. Something like:
2759 template <class T> struct S {
2760 template <class U> void f (U);
2761 };
2762 template <> template <class U> void S<int>::f(U) {}
2764 That's a specialization -- but of the entire template. */
2770 }
2773 /* This doesn't apply to variable templates. */
2776 {
2780 {
2784 }
2785 }
2788 {
2793 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2795 {
2796 tree fns;
2801 else
2802 {
2803 /* If there is no class context, the explicit instantiation
2804 must be at namespace scope. */
2807 /* Find the namespace binding, using the declaration
2808 context. */
2812 {
2815 }
2816 }
2819 }
2825 {
2827 /* A specialization in class scope. This is invalid,
2828 but the error will already have been flagged by
2829 check_specialization_scope. */
2831 else
2832 {
2833 /* It's not valid to write an explicit instantiation in
2834 class scope, e.g.:
2836 class C { template void f(); }
2838 This case is caught by the parser. However, on
2839 something like:
2841 template class C { void f(); };
2843 (which is invalid) we can get here. The error will be
2844 issued later. */
2845 ;
2846 }
2849 }
2852 {
2853 // We'll match variable templates in start_decl.
2857 /* Find the list of functions in ctype that have the same
2858 name as the declared function. */
2864 {
2869 {
2870 /* From [temp.expl.spec]:
2872 If such an explicit specialization for the member
2873 of a class template names an implicitly-declared
2874 special member function (clause _special_), the
2875 program is ill-formed.
2877 Similar language is found in [temp.explicit]. */
2880 }
2883 }
2886 {
2890 }
2891 else
2892 {
2894 tree ovl;
2896 /* For a type-conversion operator, we cannot do a
2897 name-based lookup. We might be looking for `operator
2898 int' which will be a specialization of `operator T'.
2899 So, we find *all* the conversion operators, and then
2900 select from them. */
2908 {
2910 /* There are no more conversion functions. */
2913 /* Glue all these conversion functions together
2914 with those we already have. */
2917 }
2918 }
2921 {
2924 }
2925 else
2927 }
2929 /* Figure out what exactly is being specialized at this point.
2930 Note that for an explicit instantiation, even one for a
2931 member function, we cannot tell apriori whether the
2932 instantiation is for a member template, or just a member
2933 function of a template class. Even if a member template is
2934 being instantiated, the member template arguments may be
2935 elided if they can be deduced from the rest of the
2936 declaration. */
2939 member_specialization,
2940 template_count,
2941 tsk);
2944 /* We couldn't figure out what this declaration was
2945 specializing. */
2947 else
2948 {
2960 {
2961 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2962 is done by do_decl_instantiation later. */
2968 {
2969 /* If TMPL is not the most general template (for
2970 example, if TMPL is a friend template that is
2971 injected into namespace scope), then there will
2972 be too many levels of TARGS. Remove some of them
2973 here. */
2975 tree new_targs;
2982 }
2985 }
2987 /* If we thought that the DECL was a member function, but it
2988 turns out to be specializing a static member function,
2989 make DECL a static member function as well. */
2995 /* If this is a specialization of a member template of a
2996 template class, we want to return the TEMPLATE_DECL, not
2997 the specialization of it. */
2999 {
3004 {
3005 tree parm;
3009 /* We want to use the argument list specified in the
3010 definition, not in the original declaration. */
3015 }
3018 }
3020 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3026 /* Inherit default function arguments from the template
3027 DECL is specializing. */
3031 /* This specialization has the same protection as the
3032 template it specializes. */
3036 /* 7.1.1-1 [dcl.stc]
3038 A storage-class-specifier shall not be specified in an
3039 explicit specialization...
3041 The parser rejects these, so unless action is taken here,
3042 explicit function specializations will always appear with
3043 global linkage.
3045 The action recommended by the C++ CWG in response to C++
3046 defect report 605 is to make the storage class and linkage
3047 of the explicit specialization match the templated function:
3049 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3050 */
3052 {
3056 /* A concept cannot be specialized. */
3058 {
3060 gen_tmpl);
3062 }
3064 /* This specialization has the same linkage and visibility as
3065 the function template it specializes. */
3068 {
3071 }
3074 {
3077 }
3078 }
3080 /* If DECL is a friend declaration, declared using an
3081 unqualified name, the namespace associated with DECL may
3082 have been set incorrectly. For example, in:
3084 template <typename T> void f(T);
3085 namespace N {
3086 struct S { friend void f<int>(int); }
3087 }
3089 we will have set the DECL_CONTEXT for the friend
3090 declaration to N, rather than to the global namespace. */
3095 /* This is not really a declaration of a specialization.
3096 It's just the name of an instantiation. But, it's not
3097 a request for an instantiation, either. */
3100 /* A specialization is not necessarily COMDAT. */
3106 /* If this is a full specialization, register it so that we can find
3107 it again. Partial specializations will be registered in
3108 process_partial_specialization. */
3113 /* A 'structor should already have clones. */
3119 }
3120 }
3123 }
3125 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3126 parameters. These are represented in the same format used for
3127 DECL_TEMPLATE_PARMS. */
3129 int
3131 {
3132 const_tree p1;
3133 const_tree p2;
3141 {
3153 {
3157 /* If either of the template parameters are invalid, assume
3158 they match for the sake of error recovery. */
3171 }
3172 }
3175 /* One set of parameters has more parameters lists than the
3176 other. */
3180 }
3182 /* Determine whether PARM is a parameter pack. */
3184 bool
3186 {
3187 /* Determine if we have a non-type template parameter pack. */
3194 /* If this is a list of template parameters, we could get a
3195 TYPE_DECL or a TEMPLATE_DECL. */
3199 /* Otherwise it must be a type template parameter. */
3203 }
3205 /* Determine if T is a function parameter pack. */
3207 bool
3209 {
3213 }
3215 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3216 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3218 tree
3220 {
3227 }
3229 /* Return true iff the function parameter PARAM_DECL was expanded
3230 from the function parameter pack PACK. */
3232 bool
3234 {
3239 /* The parameter pack and its pack arguments have the same
3240 DECL_PARM_INDEX. */
3242 }
3244 /* Determine whether ARGS describes a variadic template args list,
3245 i.e., one that is terminated by a template argument pack. */
3247 static bool
3249 {
3251 tree last_parm;
3265 }
3267 /* Generate a new name for the parameter pack name NAME (an
3268 IDENTIFIER_NODE) that incorporates its */
3270 static tree
3272 {
3273 /* Munge the name to include the parameter index. */
3274 #define NUMBUF_LEN 128
3288 }
3290 /* Return true if T is a primary function, class or alias template
3291 instantiation. */
3293 bool
3295 {
3309 }
3311 /* Return true if PARM is a template template parameter. */
3313 bool
3315 {
3317 }
3319 /* Return true iff PARM is a DECL representing a type template
3320 parameter. */
3322 bool
3324 {
3329 }
3331 /* Return the template parameters of T if T is a
3332 primary template instantiation, NULL otherwise. */
3334 tree
3336 {
3341 parms = INNERMOST_TEMPLATE_PARMS
3345 }
3347 /* Return the template parameters of the LEVELth level from the full list
3348 of template parameters PARMS. */
3350 tree
3352 {
3353 tree p;
3364 }
3366 /* Returns the template arguments of T if T is a template instantiation,
3367 NULL otherwise. */
3369 tree
3371 {
3379 }
3381 /* Return the argument pack elements of T if T is a template argument pack,
3382 NULL otherwise. */
3384 tree
3386 {
3392 }
3394 /* Structure used to track the progress of find_parameter_packs_r. */
3395 struct find_parameter_pack_data
3396 {
3397 /* TREE_LIST that will contain all of the parameter packs found by
3398 the traversal. */
3401 /* Set of AST nodes that have been visited by the traversal. */
3404 /* True iff we're making a type pack expansion. */
3406 };
3408 /* Identifies all of the argument packs that occur in a template
3409 argument and appends them to the TREE_LIST inside DATA, which is a
3410 find_parameter_pack_data structure. This is a subroutine of
3411 make_pack_expansion and uses_parameter_packs. */
3412 static tree
3414 {
3420 /* Handle type aliases/typedefs. */
3422 {
3429 }
3431 /* Identify whether this is a parameter pack or not. */
3433 {
3442 /* If the placeholder appears in the decl-specifier-seq of a function
3443 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3444 is a pack expansion, the invented template parameter is a template
3445 parameter pack. */
3455 {
3456 /* We don't want to walk into the type of a PARM_DECL,
3457 because we don't want to see the type parameter pack. */
3460 }
3463 /* Look through a lambda capture proxy to the field pack. */
3466 {
3472 }
3474 {
3476 find_parameter_packs_r,
3479 }
3486 /* Not a parameter pack. */
3488 }
3491 {
3492 /* Add this parameter pack to the list. */
3494 }
3500 /* This switch statement will return immediately if we don't find a
3501 parameter pack. */
3503 {
3508 /* Check the template itself. */
3511 /* Check the template arguments. */
3527 /* Fall through. */
3568 {
3569 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3570 type_pack_expansion_p to false so that any placeholders
3571 within the expression don't get marked as parameter packs. */
3579 }
3583 }
3586 }
3588 /* Determines if the expression or type T uses any parameter packs. */
3589 bool
3591 {
3600 }
3602 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3603 representation a base-class initializer into a parameter pack
3604 expansion. If all goes well, the resulting node will be an
3605 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3606 respectively. */
3607 tree
3609 {
3610 tree result;
3619 {
3620 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3621 class initializer. In this case, the TREE_PURPOSE will be a
3622 _TYPE node (representing the base class expansion we're
3623 initializing) and the TREE_VALUE will be a TREE_LIST
3624 containing the initialization arguments.
3626 The resulting expansion looks somewhat different from most
3627 expansions. Rather than returning just one _EXPANSION, we
3628 return a TREE_LIST whose TREE_PURPOSE is a
3629 TYPE_PACK_EXPANSION containing the bases that will be
3630 initialized. The TREE_VALUE will be identical to the
3631 original TREE_VALUE, which is a list of arguments that will
3632 be passed to each base. We do not introduce any new pack
3633 expansion nodes into the TREE_VALUE (although it is possible
3634 that some already exist), because the TREE_PURPOSE and
3635 TREE_VALUE all need to be expanded together with the same
3636 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3637 resulting TREE_PURPOSE will mention the parameter packs in
3638 both the bases and the arguments to the bases. */
3639 tree purpose;
3640 tree value;
3643 /* Determine which parameter packs will be used by the base
3644 class expansion. */
3653 {
3657 }
3660 {
3661 /* Collect the sets of parameter packs used in each of the
3662 initialization arguments. */
3664 {
3665 /* Determine which parameter packs will be expanded in this
3666 argument. */
3669 }
3670 }
3674 /* Create the pack expansion type for the base type. */
3679 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3680 they will rarely be compared to anything. */
3684 }
3689 /* Build the PACK_EXPANSION_* node. */
3690 result = for_types
3695 {
3696 /* Propagate type and const-expression information. */
3699 /* Mark this read now, since the expansion might be length 0. */
3701 }
3702 else
3703 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3704 they will rarely be compared to anything. */
3707 /* Determine which parameter packs will be expanded. */
3714 /* Make sure we found some parameter packs. */
3716 {
3719 else
3722 }
3728 }
3730 /* Checks T for any "bare" parameter packs, which have not yet been
3731 expanded, and issues an error if any are found. This operation can
3732 only be done on full expressions or types (e.g., an expression
3733 statement, "if" condition, etc.), because we could have expressions like:
3735 foo(f(g(h(args)))...)
3737 where "args" is a parameter pack. check_for_bare_parameter_packs
3738 should not be called for the subexpressions args, h(args),
3739 g(h(args)), or f(g(h(args))), because we would produce erroneous
3740 error messages.
3742 Returns TRUE and emits an error if there were bare parameter packs,
3743 returns FALSE otherwise. */
3744 bool
3746 {
3763 {
3766 {
3775 else
3780 else
3784 }
3787 }
3790 }
3792 /* Expand any parameter packs that occur in the template arguments in
3793 ARGS. */
3794 tree
3796 {
3802 /* First, determine if we need to expand anything, and the number of
3803 slots we'll need. */
3805 {
3810 {
3814 else
3816 }
3817 else
3818 {
3820 num_result_args++;
3821 }
3822 }
3824 /* If no expansion is necessary, we're done. */
3828 /* Expand arguments. */
3831 non_default_args_count =
3834 {
3837 {
3844 }
3845 else
3846 {
3849 }
3850 }
3854 }
3856 /* Checks if DECL shadows a template parameter.
3858 [temp.local]: A template-parameter shall not be redeclared within its
3859 scope (including nested scopes).
3861 Emits an error and returns TRUE if the DECL shadows a parameter,
3862 returns FALSE otherwise. */
3864 bool
3866 {
3867 tree olddecl;
3869 /* If we're not in a template, we can't possibly shadow a template
3870 parameter. */
3874 /* Figure out what we're shadowing. */
3879 /* If there's no previous binding for this name, we're not shadowing
3880 anything, let alone a template parameter. */
3884 /* If we're not shadowing a template parameter, we're done. Note
3885 that OLDDECL might be an OVERLOAD (or perhaps even an
3886 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3887 node. */
3891 /* We check for decl != olddecl to avoid bogus errors for using a
3892 name inside a class. We check TPFI to avoid duplicate errors for
3893 inline member templates. */
3899 /* Don't complain about the injected class name, as we've already
3900 complained about the class itself. */
3907 else
3912 }
3914 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3915 ORIG_LEVEL, DECL, and TYPE. */
3917 static tree
3921 tree decl,
3922 tree type)
3923 {
3934 }
3936 /* Find the canonical type parameter for the given template type
3937 parameter. Returns the canonical type parameter, which may be TYPE
3938 if no such parameter existed. */
3940 static tree
3942 {
3943 tree list;
3957 else
3958 {
3963 }
3964 }
3966 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3967 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3968 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3969 new one is created. */
3971 static tree
3973 tsubst_flags_t complain)
3974 {
3979 {
3998 /* Template template parameters need this. */
4000 {
4007 }
4008 }
4011 }
4013 /* Process information from new template parameter PARM and append it
4014 to the LIST being built. This new parameter is a non-type
4015 parameter iff IS_NON_TYPE is true. This new parameter is a
4016 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4017 is in PARM_LOC. */
4019 tree
4022 {
4031 {
4035 {
4039 else
4041 }
4044 }
4047 {
4053 {
4054 /* [temp.param]
4056 The top-level cv-qualifiers on the template-parameter are
4057 ignored when determining its type. */
4062 && !is_parameter_pack
4063 /* If we're in a nested template parameter list, the template
4064 template parameter could be a parameter pack. */
4066 {
4067 /* This template parameter is not a parameter pack, but it
4068 should be. Complain about "bare" parameter packs. */
4071 /* Recover by calling this a parameter pack. */
4073 }
4074 }
4076 /* A template parameter is not modifiable. */
4085 processing_template_decl,
4090 }
4091 else
4092 {
4093 tree t;
4097 {
4099 /* This is for distinguishing between real templates and template
4100 template parameters */
4104 }
4105 else
4106 {
4108 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4111 }
4118 processing_template_decl,
4122 }
4126 /* Build requirements for the type/template parameter.
4127 This must be done after SET_DECL_TEMPLATE_PARM_P or
4128 process_template_parm could fail. */
4133 /* Build the parameter node linking the parameter declaration,
4134 its default argument (if any), and its constraints (if any). */
4139 }
4141 /* The end of a template parameter list has been reached. Process the
4142 tree list into a parameter vector, converting each parameter into a more
4143 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4144 as PARM_DECLs. */
4146 tree
4148 {
4153 /* Pop the dummy parameter level and add the real one. */
4156 current_template_parms
4161 {
4165 }
4170 }
4172 // Explicitly indicate the end of the template parameter list. We assume
4173 // that the current template parameters have been constructed and/or
4174 // managed explicitly, as when creating new template template parameters
4175 // from a shorthand constraint.
4176 void
4178 {
4180 }
4182 /* end_template_decl is called after a template declaration is seen. */
4184 void
4186 {
4192 /* This matches the pushlevel in begin_template_parm_list. */
4197 }
4199 /* Takes a TREE_LIST representing a template parameter and convert it
4200 into an argument suitable to be passed to the type substitution
4201 functions. Note that If the TREE_LIST contains an error_mark
4202 node, the returned argument is error_mark_node. */
4204 tree
4206 {
4219 {
4223 {
4224 /* Turn this argument into a TYPE_ARGUMENT_PACK
4225 with a single element, which expands T. */
4234 }
4235 }
4236 else
4237 {
4241 {
4242 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4243 with a single element, which expands T. */
4255 }
4256 else
4258 }
4260 }
4262 /* Given a set of template parameters, return them as a set of template
4263 arguments. The template parameters are represented as a TREE_VEC, in
4264 the form documented in cp-tree.h for template arguments. */
4266 static tree
4268 {
4269 tree header;
4274 /* If there is only one level of template parameters, we do not
4275 create a TREE_VEC of TREE_VECs. Instead, we return a single
4276 TREE_VEC containing the arguments. */
4281 {
4294 else
4296 }
4299 }
4301 /* Within the declaration of a template, return the currently active
4302 template parameters as an argument TREE_VEC. */
4304 static tree
4306 {
4308 }
4310 /* Update the declared TYPE by doing any lookups which were thought to be
4311 dependent, but are not now that we know the SCOPE of the declarator. */
4313 tree
4315 {
4326 /* Don't bother building up the args in this case. */
4328 {
4329 /* tsubst in the args corresponding to the template parameters,
4330 including auto if present. Most things will be unchanged, but
4331 make_typename_type and tsubst_qualified_id will resolve
4332 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4335 tree pushed;
4337 {
4341 }
4346 }
4352 {
4355 else
4357 }
4359 }
4361 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4362 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4363 the new template is a member template. */
4365 tree
4367 {
4375 }
4377 struct template_parm_data
4378 {
4379 /* The level of the template parameters we are currently
4380 processing. */
4383 /* The index of the specialization argument we are currently
4384 processing. */
4387 /* An array whose size is the number of template parameters. The
4388 elements are nonzero if the parameter has been used in any one
4389 of the arguments processed so far. */
4392 /* An array whose size is the number of template arguments. The
4393 elements are nonzero if the argument makes use of template
4394 parameters of this level. */
4396 };
4398 /* Subroutine of push_template_decl used to see if each template
4399 parameter in a partial specialization is used in the explicit
4400 argument list. If T is of the LEVEL given in DATA (which is
4401 treated as a template_parm_data*), then DATA->PARMS is marked
4402 appropriately. */
4404 static int
4406 {
4414 {
4417 }
4419 /* Return zero so that for_each_template_parm will continue the
4420 traversal of the tree; we want to mark *every* template parm. */
4422 }
4424 /* Process the partial specialization DECL. */
4426 static tree
4428 {
4435 tree inner_parms;
4436 tree inst;
4446 /* A concept cannot be specialized. */
4448 {
4451 }
4456 /* We check that each of the template parameters given in the
4457 partial specialization is used in the argument list to the
4458 specialization. For example:
4460 template <class T> struct S;
4461 template <class T> struct S<T*>;
4463 The second declaration is OK because `T*' uses the template
4464 parameter T, whereas
4466 template <class T> struct S<int>;
4468 is no good. Even trickier is:
4470 template <class T>
4471 struct S1
4472 {
4473 template <class U>
4474 struct S2;
4475 template <class U>
4476 struct S2<T>;
4477 };
4479 The S2<T> declaration is actually invalid; it is a
4480 full-specialization. Of course,
4482 template <class U>
4483 struct S2<T (*)(U)>;
4485 or some such would have been OK. */
4493 {
4498 NULL,
4500 }
4503 {
4504 /* One of the template parms was not used in a deduced context in the
4505 specialization. */
4507 {
4511 }
4515 }
4520 /* [temp.class.spec]
4522 The argument list of the specialization shall not be identical to
4523 the implicit argument list of the primary template. */
4524 tree main_args
4527 && (!flag_concepts
4530 {
4534 else
4538 }
4540 /* A partial specialization that replaces multiple parameters of the
4541 primary template with a pack expansion is less specialized for those
4542 parameters. */
4544 {
4546 "primary template because it replaces multiple parameters "
4550 }
4552 /* [temp.class.spec]
4554 A partially specialized non-type argument expression shall not
4555 involve template parameters of the partial specialization except
4556 when the argument expression is a simple identifier.
4558 The type of a template parameter corresponding to a specialized
4559 non-type argument shall not be dependent on a parameter of the
4560 specialization.
4562 Also, we verify that pack expansions only occur at the
4563 end of the argument list. */
4567 {
4574 {
4575 /* Extract the arguments from the argument pack. We'll be
4576 iterating over these in the following loop. */
4579 }
4582 {
4584 /* Get the Jth argument in the parameter pack. */
4588 {
4589 /* Pack expansions must come at the end of the
4590 argument list. */
4593 {
4597 else
4600 }
4601 }
4604 /* We only care about the pattern. */
4610 /* This next two lines are the `argument expression is not just a
4611 simple identifier' condition and also the `specialized
4612 non-type argument' bit. */
4616 {
4620 arg);
4621 else
4622 {
4623 /* Look at the corresponding template parameter,
4624 marking which template parameters its type depends
4625 upon. */
4629 {
4630 /* We haven't yet initialized TPD2. Do so now. */
4632 /* The number of parameters here is the number in the
4633 main template, which, as checked in the assertion
4634 above, is NARGS. */
4638 }
4640 /* Mark the template parameters. But this time, we're
4641 looking for the template parameters of the main
4642 template, not in the specialization. */
4649 NULL,
4653 {
4654 /* The type depended on some template parameters.
4655 If they are fully specialized in the
4656 specialization, that's OK. */
4665 "type %qT of template argument %qE depends "
4667 "type %qT of template argument %qE depends "
4669 type,
4670 arg);
4671 }
4672 }
4673 }
4674 }
4675 }
4677 /* We should only get here once. */
4681 // Build the template decl.
4691 /* We didn't register this in check_explicit_specialization so we could
4692 wait until the constraints were set. */
4694 else
4704 {
4710 {
4718 "declaration of %qD ambiguates earlier template "
4722 "partial specialization of %qD after instantiation "
4724 }
4725 }
4728 }
4730 /* PARM is a template parameter of some form; return the corresponding
4731 TEMPLATE_PARM_INDEX. */
4733 static tree
4735 {
4748 }
4750 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4751 parameter packs used by the template parameter PARM. */
4753 static void
4755 {
4756 /* A type parm can't refer to another parm. */
4760 {
4764 }
4771 }
4773 /* PARM is a template parameter pack. Return any parameter packs used in
4774 its type or the type of any of its template parameters. If there are
4775 any such packs, it will be instantiated into a fixed template parameter
4776 list by partial instantiation rather than be fully deduced. */
4778 tree
4780 {
4781 /* This can only be true in a member template. */
4784 /* This can only be true for a parameter pack. */
4787 /* A type parm can't refer to another parm. */
4801 }
4803 /* Check that a template declaration's use of default arguments and
4804 parameter packs is not invalid. Here, PARMS are the template
4805 parameters. IS_PRIMARY is true if DECL is the thing declared by
4806 a primary template. IS_PARTIAL is true if DECL is a partial
4807 specialization.
4809 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4810 declaration (but not a definition); 1 indicates a declaration, 2
4811 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4812 emitted for extraneous default arguments.
4814 Returns TRUE if there were no errors found, FALSE otherwise. */
4816 bool
4819 {
4822 tree parm_level;
4825 /* [temp.param]
4827 A default template-argument shall not be specified in a
4828 function template declaration or a function template definition, nor
4829 in the template-parameter-list of the definition of a member of a
4830 class template. */
4834 /* You can't have a function template declaration in a local
4835 scope, nor you can you define a member of a class template in a
4836 local scope. */
4844 /* A lambda doesn't have an explicit declaration; don't complain
4845 about the parms of the enclosing class. */
4852 /* If this is either a friend defined in the scope of the class
4853 or a member function. */
4859 /* And, if it was a member function, it really was defined in
4860 the scope of the class. */
4863 /* We already checked these parameters when the template was
4864 declared, so there's no need to do it again now. This function
4865 was defined in class scope, but we're processing its body now
4866 that the class is complete. */
4869 /* Core issue 226 (C++0x only): the following only applies to class
4870 templates. */
4873 {
4874 /* [temp.param]
4876 If a template-parameter has a default template-argument, all
4877 subsequent template-parameters shall have a default
4878 template-argument supplied. */
4880 {
4887 {
4897 {
4899 /* For better subsequent error-recovery, we indicate that
4900 there should have been a default argument. */
4903 }
4905 && !is_friend_decl
4906 /* Don't complain about an enclosing partial
4907 specialization. */
4912 /* A fixed parameter pack will be partially
4913 instantiated into a fixed length list. */
4915 {
4916 /* A primary class template can only have one
4917 parameter pack, at the end of the template
4918 parameter list. */
4926 }
4927 }
4928 }
4929 }
4932 || is_partial
4933 || !is_primary
4935 /* For an ordinary class template, default template arguments are
4936 allowed at the innermost level, e.g.:
4937 template <class T = int>
4938 struct S {};
4939 but, in a partial specialization, they're not allowed even
4940 there, as we have in [temp.class.spec]:
4942 The template parameter list of a specialization shall not
4943 contain default template argument values.
4945 So, for a partial specialization, or for a function template
4946 (in C++98/C++03), we look at all of them. */
4947 ;
4948 else
4949 /* But, for a primary class template that is not a partial
4950 specialization we look at all template parameters except the
4951 innermost ones. */
4954 /* Figure out what error message to issue. */
4969 else
4970 /* Per [temp.param]/9, "A default template-argument shall not be
4971 specified in the template-parameter-lists of the definition of
4972 a member of a class template that appears outside of the member's
4973 class.", thus if we aren't handling a member of a class template
4974 there is no need to examine the parameters. */
4978 /* If we're inside a class definition, there's no need to
4979 examine the parameters to the class itself. On the one
4980 hand, they will be checked when the class is defined, and,
4981 on the other, default arguments are valid in things like:
4982 template <class T = double>
4983 struct S { template <class U> void f(U); };
4984 Here the default argument for `S' has no bearing on the
4985 declaration of `f'. */
4987 else
4988 /* Check everything. */
4994 {
5001 {
5006 {
5008 {
5015 }
5017 /* Clear out the default argument so that we are not
5018 confused later. */
5020 }
5021 }
5023 /* At this point, if we're still interested in issuing messages,
5024 they must apply to classes surrounding the object declared. */
5028 }
5031 }
5033 /* Worker for push_template_decl_real, called via
5034 for_each_template_parm. DATA is really an int, indicating the
5035 level of the parameters we are interested in. If T is a template
5036 parameter of that level, return nonzero. */
5038 static int
5040 {
5046 else
5049 }
5051 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5052 parameters given by current_template_args, or reuses a
5053 previously existing one, if appropriate. Returns the DECL, or an
5054 equivalent one, if it is replaced via a call to duplicate_decls.
5056 If IS_FRIEND is true, DECL is a friend declaration. */
5058 tree
5060 {
5061 tree tmpl;
5062 tree args;
5063 tree info;
5064 tree ctx;
5068 /* True if the template is a member template, in the sense of
5069 [temp.mem]. */
5075 /* See if this is a partial specialization. */
5088 /* For a friend, we want the context of the friend function, not
5089 the type of which it is a friend. */
5093 /* In the case of a virtual function, we want the class in which
5094 it is defined. */
5096 else
5097 /* Otherwise, if we're currently defining some class, the DECL
5098 is assumed to be a member of the class. */
5107 /* See if this is a primary template. */
5110 /* A friend template that specifies a class context, i.e.
5111 template <typename T> friend void A<T>::f();
5112 is not primary. */
5117 else
5121 {
5128 {
5131 }
5133 {
5135 {
5138 }
5140 {
5141 /* [temp.mem]
5143 A destructor shall not be a member template. */
5146 }
5153 {
5154 /* [basic.stc.dynamic.allocation]
5156 An allocation function can be a function
5157 template. ... Template allocation functions shall
5158 have two or more parameters. */
5161 }
5162 }
5168 /* alias-declaration */
5172 else
5173 {
5176 }
5177 }
5179 /* Check to see that the rules regarding the use of default
5180 arguments are not being violated. */
5184 /* Ensure that there are no parameter packs in the type of this
5185 declaration that have not been expanded. */
5187 {
5188 /* Check each of the arguments individually to see if there are
5189 any bare parameter packs. */
5195 {
5198 {
5199 /* This is a PARM_DECL that contains unexpanded parameter
5200 packs. We have already complained about this in the
5201 check_for_bare_parameter_packs call, so just replace
5202 these types with ERROR_MARK_NODE. */
5205 }
5209 }
5211 /* Check for bare parameter packs in the return type and the
5212 exception specifiers. */
5214 /* Errors were already issued, set return type to int
5215 as the frontend doesn't expect error_mark_node as
5216 the return type. */
5220 }
5225 {
5228 }
5241 {
5246 /* If DECL is a TYPE_DECL for a class-template, then there won't
5247 be DECL_LANG_SPECIFIC. The information equivalent to
5248 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5252 {
5253 /* Since a template declaration already existed for this
5254 class-type, we must be redeclaring it here. Make sure
5255 that the redeclaration is valid. */
5257 current_template_parms,
5259 /* We don't need to create a new TEMPLATE_DECL; just use the
5260 one we already had. */
5262 }
5263 else
5264 {
5266 member_template_p);
5271 {
5272 /* A specialization of a member template of a template
5273 class. */
5277 }
5278 }
5279 }
5280 else
5281 {
5287 {
5290 }
5298 {
5299 tree new_tmpl;
5301 /* The declaration is a specialization of a member
5302 template, declared outside the class. Therefore, the
5303 innermost template arguments will be NULL, so we
5304 replace them with the arguments determined by the
5305 earlier call to check_explicit_specialization. */
5308 new_tmpl
5310 member_template_p);
5320 args,
5323 }
5325 /* Make sure the template headers we got make sense. */
5330 {
5335 }
5336 else
5338 {
5343 {
5347 else
5351 /* Avoid crash in import_export_decl. */
5354 }
5359 /* Can happen in erroneous input. */
5361 else
5363 }
5365 /* Check that the parms are used in the appropriate qualifying scopes
5366 in the declarator. */
5370 {
5376 /* Avoid crash in import_export_decl. */
5379 }
5380 }
5385 /* Push template declarations for global functions and types. Note
5386 that we do not try to push a global template friend declared in a
5387 template class; such a thing may well depend on the template
5388 parameters of the class. */
5391 {
5396 /* Hide template friend classes that haven't been declared yet. */
5398 {
5401 }
5402 }
5405 {
5411 {
5414 /* It is a conversion operator. See if the type converted to
5415 depends on innermost template operands. */
5418 depth))
5420 }
5422 /* Give template template parms a DECL_CONTEXT of the template
5423 for which they are a parameter. */
5426 {
5430 }
5436 }
5438 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5439 back to its most general template. If TMPL is a specialization,
5440 ARGS may only have the innermost set of arguments. Add the missing
5441 argument levels if necessary. */
5449 else
5450 {
5455 }
5458 && !is_friend
5461 /* Set DECL_COMDAT on template instantiations; if we force
5462 them to be emitted by explicit instantiation or -frepo,
5463 mark_needed will tell cgraph to do the right thing. */
5467 }
5469 tree
5471 {
5473 }
5475 /* FN is an inheriting constructor that inherits from the constructor
5476 template INHERITED; turn FN into a constructor template with a matching
5477 template header. */
5479 tree
5481 {
5482 tree inner_parms
5485 tree parms
5496 }
5498 /* Called when a class template TYPE is redeclared with the indicated
5499 template PARMS, e.g.:
5501 template <class T> struct S;
5502 template <class T> struct S {}; */
5504 bool
5506 {
5507 tree tmpl;
5508 tree tmpl_parms;
5512 {
5515 }
5519 /* The type is nested in some template class. Nothing to worry
5520 about here; there are no new template parameters for the nested
5521 type. */
5525 {
5527 tmpl);
5529 }
5535 {
5545 }
5548 {
5549 tree tmpl_parm;
5550 tree parm;
5551 tree tmpl_default;
5552 tree parm_default;
5566 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5567 TEMPLATE_DECL. */
5577 {
5581 }
5584 {
5585 /* We have in [temp.param]:
5587 A template-parameter may not be given default arguments
5588 by two different declarations in the same scope. */
5593 }
5596 /* Update the previous template parameters (which are the ones
5597 that will really count) with the new default value. */
5600 /* Update the new parameters, too; they'll be used as the
5601 parameters for any members. */
5604 /* Give each template template parm in this redeclaration a
5605 DECL_CONTEXT of the template for which they are a parameter. */
5607 {
5610 }
5611 }
5613 // Cannot redeclare a class template with a different set of constraints.
5615 {
5620 }
5623 }
5625 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5626 to be used when the caller has already checked
5627 (processing_template_decl
5628 && !instantiation_dependent_expression_p (expr)
5629 && potential_constant_expression (expr))
5630 and cleared processing_template_decl. */
5632 tree
5634 {
5637 complain,
5641 }
5643 /* Simplify EXPR if it is a non-dependent expression. Returns the
5644 (possibly simplified) expression. */
5646 tree
5648 {
5652 /* If we're in a template, but EXPR isn't value dependent, simplify
5653 it. We're supposed to treat:
5655 template <typename T> void f(T[1 + 1]);
5656 template <typename T> void f(T[2]);
5658 as two declarations of the same function, for example. */
5661 {
5662 processing_template_decl_sentinel s;
5664 }
5666 }
5668 tree
5670 {
5672 }
5674 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5675 an uninstantiated expression. */
5677 tree
5679 {
5683 {
5686 else
5687 {
5688 processing_template_decl_sentinel s;
5690 }
5691 }
5693 }
5695 /* True iff T is a specialization of a variable template. */
5697 bool
5699 {
5704 }
5706 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5707 template declaration, or a TYPE_DECL for an alias declaration. */
5709 bool
5711 {
5719 }
5721 /* Return TRUE iff T is a specialization of an alias template. */
5723 bool
5725 {
5726 /* It's an alias template specialization if it's an alias and its
5727 TYPE_NAME is a specialization of a primary template. */
5729 {
5733 {
5736 }
5737 }
5739 }
5741 /* An alias template is complex from a SFINAE perspective if a template-id
5742 using that alias can be ill-formed when the expansion is not, as with
5743 the void_t template. We determine this by checking whether the
5744 expansion for the alias template uses all its template parameters. */
5746 struct uses_all_template_parms_data
5747 {
5750 };
5752 static int
5754 {
5762 }
5764 static bool
5766 {
5781 }
5783 /* Return TRUE iff T is a specialization of a complex alias template with
5784 dependent template-arguments. */
5786 bool
5788 {
5791 && (any_dependent_template_arguments_p
5793 }
5795 /* Return the number of innermost template parameters in TMPL. */
5797 static int
5799 {
5802 }
5804 /* Return either TMPL or another template that it is equivalent to under DR
5805 1286: An alias that just changes the name of a template is equivalent to
5806 the other template. */
5808 static tree
5810 {
5813 {
5816 {
5821 {
5822 tree alias_args = INNERMOST_TEMPLATE_ARGS
5826 /* The alias type is equivalent to the pattern of the
5827 underlying template, so strip the alias. */
5830 }
5831 }
5833 }
5835 }
5837 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5838 must be a function or a pointer-to-function type, as specified
5839 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5840 and check that the resulting function has external linkage. */
5842 static tree
5844 tsubst_flags_t complain)
5845 {
5848 linkage_kind linkage;
5860 /* [temp.arg.nontype]/1
5862 A template-argument for a non-type, non-template template-parameter
5863 shall be one of:
5864 [...]
5865 -- the address of an object or function with external [C++11: or
5866 internal] linkage. */
5869 {
5871 {
5877 else
5880 }
5882 }
5886 {
5888 {
5893 else
5897 }
5899 }
5902 }
5904 /* Subroutine of convert_nontype_argument.
5905 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5906 Emit an error otherwise. */
5908 static bool
5910 tsubst_flags_t complain)
5911 {
5922 {
5926 }
5928 }
5930 /* Returns TRUE iff the address of OP is value-dependent.
5932 14.6.2.4 [temp.dep.temp]:
5933 A non-integral non-type template-argument is dependent if its type is
5934 dependent or it has either of the following forms
5935 qualified-id
5936 & qualified-id
5937 and contains a nested-name-specifier which specifies a class-name that
5938 names a dependent type.
5940 We generalize this to just say that the address of a member of a
5941 dependent class is value-dependent; the above doesn't cover the
5942 address of a static data member named with an unqualified-id. */
5944 static bool
5946 {
5947 /* We could use get_inner_reference here, but there's no need;
5948 this is only relevant for template non-type arguments, which
5949 can only be expressed as &id-expression. */
5951 {
5955 }
5958 }
5960 /* The next set of functions are used for providing helpful explanatory
5961 diagnostics for failed overload resolution. Their messages should be
5962 indented by two spaces for consistency with the messages in
5963 call.c */
5965 static int
5967 {
5969 }
5971 static int
5973 {
5978 }
5980 static int
5982 {
5984 }
5986 static int
5988 {
5994 }
5996 static int
5998 {
6002 }
6004 static int
6006 {
6009 " template parameter %qD is not a parameter pack, but "
6013 }
6015 static int
6017 {
6020 " template argument %qE does not match "
6024 }
6026 static int
6028 {
6032 }
6034 static int
6036 {
6042 }
6044 static int
6046 {
6048 {
6053 else
6055 " deduced conflicting values for non-type parameter "
6057 }
6059 }
6061 static int
6063 {
6066 " variable-sized array type %qT is not "
6068 arg);
6070 }
6072 static int
6074 {
6078 arg);
6080 }
6082 static int
6084 {
6086 {
6092 else
6097 }
6099 }
6101 static int
6103 {
6105 }
6107 static int
6110 {
6112 }
6114 static int
6117 {
6123 }
6125 static int
6128 {
6131 {
6139 }
6141 }
6143 static int
6145 {
6148 " template parameters of a template template argument are "
6151 }
6153 static int
6155 {
6161 }
6163 static int
6165 {
6170 }
6172 static int
6174 {
6178 arg);
6180 }
6182 /* Attempt to convert the non-type template parameter EXPR to the
6183 indicated TYPE. If the conversion is successful, return the
6184 converted value. If the conversion is unsuccessful, return
6185 NULL_TREE if we issued an error message, or error_mark_node if we
6186 did not. We issue error messages for out-and-out bad template
6187 parameters, but not simply because the conversion failed, since we
6188 might be just trying to do argument deduction. Both TYPE and EXPR
6189 must be non-dependent.
6191 The conversion follows the special rules described in
6192 [temp.arg.nontype], and it is much more strict than an implicit
6193 conversion.
6195 This function is called twice for each template argument (see
6196 lookup_template_class for a more accurate description of this
6197 problem). This means that we need to handle expressions which
6198 are not valid in a C++ source, but can be created from the
6199 first call (for instance, casts to perform conversions). These
6200 hacks can go away after we fix the double coercion problem. */
6202 static tree
6204 {
6205 tree expr_type;
6207 /* Detect immediately string literals as invalid non-type argument.
6208 This special-case is not needed for correctness (we would easily
6209 catch this later), but only to provide better diagnostic for this
6210 common user mistake. As suggested by DR 100, we do not mention
6211 linkage issues in the diagnostic as this is not the point. */
6212 /* FIXME we're making this OK. */
6214 {
6220 }
6222 /* Add the ADDR_EXPR now for the benefit of
6223 value_dependent_expression_p. */
6226 {
6230 }
6232 /* If we are in a template, EXPR may be non-dependent, but still
6233 have a syntactic, rather than semantic, form. For example, EXPR
6234 might be a SCOPE_REF, rather than the VAR_DECL to which the
6235 SCOPE_REF refers. Preserving the qualifying scope is necessary
6236 so that access checking can be performed when the template is
6237 instantiated -- but here we need the resolved form so that we can
6238 convert the argument. */
6251 else
6254 /* If the argument is non-dependent, perform any conversions in
6255 non-dependent context as well. */
6260 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6261 to a non-type argument of "nullptr". */
6265 /* In C++11, integral or enumeration non-type template arguments can be
6266 arbitrary constant expressions. Pointer and pointer to
6267 member arguments can be general constant expressions that evaluate
6268 to a null value, but otherwise still need to be of a specific form. */
6270 {
6272 /* A PTRMEM_CST is already constant, and a valid template
6273 argument for a parameter of pointer to member type, we just want
6274 to leave it in that form rather than lower it to a
6279 {
6283 {
6287 }
6288 }
6290 {
6295 }
6296 }
6298 /* HACK: Due to double coercion, we can get a
6299 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6300 which is the tree that we built on the first call (see
6301 below when coercing to reference to object or to reference to
6302 function). We just strip everything and get to the arg.
6303 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6304 for examples. */
6306 {
6312 {
6313 /* ??? Maybe we could use convert_from_reference here, but we
6314 would need to relax its constraints because the NOP_EXPR
6315 could actually change the type to something more cv-qualified,
6316 and this is not folded by convert_from_reference. */
6321 && (same_type_ignoring_top_level_qualifiers_p
6324 {
6327 }
6328 }
6329 }
6331 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6332 parameter is a pointer to object, through decay and
6333 qualification conversion. Let's strip everything. */
6335 {
6340 {
6341 /* Skip the ADDR_EXPR only if it is part of the decay for
6342 an array. Otherwise, it is part of the original argument
6343 in the source code. */
6348 }
6349 }
6351 /* [temp.arg.nontype]/5, bullet 1
6353 For a non-type template-parameter of integral or enumeration type,
6354 integral promotions (_conv.prom_) and integral conversions
6355 (_conv.integral_) are applied. */
6357 {
6366 /* Notice that there are constant expressions like '4 % 0' which
6367 do not fold into integer constants. */
6369 {
6371 {
6382 /* else cxx_constant_value complained but gave us
6383 a real constant, so go ahead. */
6385 }
6386 else
6388 }
6390 /* Avoid typedef problems. */
6393 }
6394 /* [temp.arg.nontype]/5, bullet 2
6396 For a non-type template-parameter of type pointer to object,
6397 qualification conversions (_conv.qual_) and the array-to-pointer
6398 conversion (_conv.array_) are applied. */
6400 {
6401 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6403 A template-argument for a non-type, non-template template-parameter
6404 shall be one of: [...]
6406 -- the name of a non-type template-parameter;
6407 -- the address of an object or function with external linkage, [...]
6408 expressed as "& id-expression" where the & is optional if the name
6409 refers to a function or array, or if the corresponding
6410 template-parameter is a reference.
6412 Here, we do not care about functions, as they are invalid anyway
6413 for a parameter of type pointer-to-object. */
6416 /* Non-type template parameters are OK. */
6417 ;
6422 {
6424 {
6427 "because %qD is a variable, not the address of "
6430 }
6432 {
6438 }
6439 /* Other values, like integer constants, might be valid
6440 non-type arguments of some other type. */
6442 }
6443 else
6444 {
6445 tree decl;
6450 {
6455 }
6457 {
6463 }
6465 {
6470 }
6471 }
6480 }
6481 /* [temp.arg.nontype]/5, bullet 3
6483 For a non-type template-parameter of type reference to object, no
6484 conversions apply. The type referred to by the reference may be more
6485 cv-qualified than the (otherwise identical) type of the
6486 template-argument. The template-parameter is bound directly to the
6487 template-argument, which must be an lvalue. */
6489 {
6491 expr_type))
6495 {
6500 }
6503 {
6508 }
6510 /* [temp.arg.nontype]/1
6512 A template-argument for a non-type, non-template template-parameter
6513 shall be one of: [...]
6515 -- the address of an object or function with external linkage. */
6518 {
6521 {
6524 "because a reference variable does not have a constant "
6527 }
6528 }
6531 {
6537 }
6539 /* DR 1155 allows internal linkage in C++11 and up. */
6542 {
6548 }
6551 }
6552 /* [temp.arg.nontype]/5, bullet 4
6554 For a non-type template-parameter of type pointer to function, only
6555 the function-to-pointer conversion (_conv.func_) is applied. If the
6556 template-argument represents a set of overloaded functions (or a
6557 pointer to such), the matching function is selected from the set
6558 (_over.over_). */
6560 {
6561 /* If the argument is a template-id, we might not have enough
6562 context information to decay the pointer. */
6564 {
6568 }
6571 /* Null pointer values are OK in C++11. */
6577 }
6578 /* [temp.arg.nontype]/5, bullet 5
6580 For a non-type template-parameter of type reference to function, no
6581 conversions apply. If the template-argument represents a set of
6582 overloaded functions, the matching function is selected from the set
6583 (_over.over_). */
6585 {
6587 {
6589 {
6594 }
6596 }
6603 }
6604 /* [temp.arg.nontype]/5, bullet 6
6606 For a non-type template-parameter of type pointer to member function,
6607 no conversions apply. If the template-argument represents a set of
6608 overloaded member functions, the matching member function is selected
6609 from the set (_over.over_). */
6611 {
6616 /* [temp.arg.nontype] bullet 1 says the pointer to member
6617 expression must be a pointer-to-member constant. */
6621 /* There is no way to disable standard conversions in
6622 resolve_address_of_overloaded_function (called by
6623 instantiate_type). It is possible that the call succeeded by
6624 converting &B::I to &D::I (where B is a base of D), so we need
6625 to reject this conversion here.
6627 Actually, even if there was a way to disable standard conversions,
6628 it would still be better to reject them here so that we can
6629 provide a superior diagnostic. */
6631 {
6633 {
6637 /* If we are just one standard conversion off, explain. */
6641 }
6643 }
6644 }
6645 /* [temp.arg.nontype]/5, bullet 7
6647 For a non-type template-parameter of type pointer to data member,
6648 qualification conversions (_conv.qual_) are applied. */
6650 {
6651 /* [temp.arg.nontype] bullet 1 says the pointer to member
6652 expression must be a pointer-to-member constant. */
6659 }
6661 {
6663 {
6668 }
6670 }
6671 /* A template non-type parameter must be one of the above. */
6672 else
6675 /* Sanity check: did we actually convert the argument to the
6676 right type? */
6680 }
6682 /* Subroutine of coerce_template_template_parms, which returns 1 if
6683 PARM_PARM and ARG_PARM match using the rule for the template
6684 parameters of template template parameters. Both PARM and ARG are
6685 template parameters; the rest of the arguments are the same as for
6686 coerce_template_template_parms.
6687 */
6688 static int
6690 tree arg,
6691 tsubst_flags_t complain,
6692 tree in_decl,
6693 tree outer_args)
6694 {
6703 {
6705 /* We encounter instantiations of templates like
6706 template <template <template <class> class> class TT>
6707 class C; */
6708 {
6715 }
6716 /* Fall through. */
6721 /* Argument is a parameter pack but parameter is not. */
6726 /* The tsubst call is used to handle cases such as
6728 template <int> class C {};
6729 template <class T, template <T> class TT> class D {};
6730 D<int, C> d;
6732 i.e. the parameter list of TT depends on earlier parameters. */
6734 {
6739 }
6743 /* Argument is a parameter pack but parameter is not. */
6750 }
6753 }
6756 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6757 template template parameters. Both PARM_PARMS and ARG_PARMS are
6758 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6759 or PARM_DECL.
6761 Consider the example:
6762 template <class T> class A;
6763 template<template <class U> class TT> class B;
6765 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6766 the parameters to A, and OUTER_ARGS contains A. */
6768 static int
6770 tree arg_parms,
6771 tsubst_flags_t complain,
6772 tree in_decl,
6773 tree outer_args)
6774 {
6785 /* Determine whether we have a parameter pack at the end of the
6786 template template parameter's template parameter list. */
6788 {
6795 {
6809 }
6810 }
6816 /* Check all of the template parameters except the parameter pack at
6817 the end (if any). */
6819 {
6828 outer_args))
6831 }
6834 {
6835 /* Check each of the template parameters in the template
6836 argument against the template parameter pack at the end of
6837 the template template parameter. */
6844 {
6851 outer_args))
6853 }
6854 }
6857 }
6859 /* Verifies that the deduced template arguments (in TARGS) for the
6860 template template parameters (in TPARMS) represent valid bindings,
6861 by comparing the template parameter list of each template argument
6862 to the template parameter list of its corresponding template
6863 template parameter, in accordance with DR150. This
6864 routine can only be called after all template arguments have been
6865 deduced. It will return TRUE if all of the template template
6866 parameter bindings are okay, FALSE otherwise. */
6867 bool
6869 {
6873 /* We're dealing with template parms in this process. */
6879 {
6884 {
6889 {
6890 /* Look inside the argument pack. */
6893 }
6896 {
6900 /* Extract the next argument from the argument
6901 pack. */
6905 /* Look at the pattern of the pack expansion. */
6908 /* Extract the template parameters from the template
6909 argument. */
6915 /* Verify that we can coerce the template template
6916 parameters from the template argument to the template
6917 parameter. This requires an exact match. */
6919 && !coerce_template_template_parms
6921 targ_parms,
6922 tf_none,
6923 tparm,
6924 targs))
6925 {
6928 }
6929 }
6930 }
6931 }
6933 out:
6937 }
6939 /* Since type attributes aren't mangled, we need to strip them from
6940 template type arguments. */
6942 static tree
6944 {
6954 }
6956 // A template declaration can be substituted for a constrained
6957 // template template parameter only when the argument is more
6958 // constrained than the parameter.
6959 static bool
6961 {
6964 /* For now, allow constrained template template arguments
6965 and unconstrained template template parameters. */
6971 // If the template parameter is constrained, we need to rewrite its
6972 // constraints in terms of the ARG's template parameters. This ensures
6973 // that all of the template parameter types will have the same depth.
6974 //
6975 // Note that this is only valid when coerce_template_template_parm is
6976 // true for the innermost template parameters of PARM and ARG. In other
6977 // words, because coercion is successful, this conversion will be valid.
6979 {
6986 }
6989 }
6991 // Convert a placeholder argument into a binding to the original
6992 // parameter. The original parameter is saved as the TREE_TYPE of
6993 // ARG.
6996 {
6999 }
7001 /* Convert the indicated template ARG as necessary to match the
7002 indicated template PARM. Returns the converted ARG, or
7003 error_mark_node if the conversion was unsuccessful. Error and
7004 warning messages are issued under control of COMPLAIN. This
7005 conversion is for the Ith parameter in the parameter list. ARGS is
7006 the full set of template arguments deduced so far. */
7008 static tree
7010 tree arg,
7011 tree args,
7012 tsubst_flags_t complain,
7014 tree in_decl)
7015 {
7016 tree orig_arg;
7017 tree val;
7023 /* Trivially convert placeholders. */
7029 {
7030 /* The template argument was the name of some
7031 member function. That's usually
7032 invalid, but static members are OK. In any
7033 case, grab the underlying fields/functions
7034 and issue an error later if required. */
7037 }
7045 /* When determining whether an argument pack expansion is a template,
7046 look at the pattern. */
7050 /* Deal with an injected-class-name used as a template template arg. */
7052 {
7055 {
7065 }
7066 }
7068 is_tmpl_type =
7084 {
7086 {
7090 }
7093 "to refer to a type member of a template parameter, "
7098 typename_type,
7099 complain);
7102 }
7104 {
7106 {
7108 {
7120 else
7123 }
7124 }
7126 }
7128 {
7130 {
7137 else
7140 }
7142 }
7145 {
7147 {
7151 /* The number of argument required is not known yet.
7152 Just accept it for now. */
7154 else
7155 {
7157 tree argparm;
7159 /* Strip alias templates that are equivalent to another
7160 template. */
7166 args))
7167 {
7170 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7171 TEMPLATE_DECL. */
7173 {
7178 }
7179 }
7180 else
7181 {
7183 {
7190 }
7193 }
7195 // Check that the constraints are compatible before allowing the
7196 // substitution.
7199 {
7201 {
7207 }
7209 }
7210 }
7211 }
7212 else
7214 /* We only form one instance of each template specialization.
7215 Therefore, if we use a non-canonical variant (i.e., a
7216 typedef), any future messages referring to the type will use
7217 the typedef, which is confusing if those future uses do not
7218 themselves also use the typedef. */
7221 }
7222 else
7223 {
7230 {
7233 else
7234 {
7235 /* Not sure if this is reachable, but it doesn't hurt
7236 to be robust. */
7239 }
7240 }
7243 /* We used to call digest_init here. However, digest_init
7244 will report errors, which we don't want when complain
7245 is zero. More importantly, digest_init will try too
7246 hard to convert things: for example, `0' should not be
7247 converted to pointer type at this point according to
7248 the standard. Accepting this is not merely an
7249 extension, since deciding whether or not these
7250 conversions can occur is part of determining which
7251 function template to call, or whether a given explicit
7252 argument specification is valid. */
7254 else
7255 {
7258 }
7266 {
7267 /* Reject template arguments that are references to built-in
7268 functions with no library fallbacks. */
7276 }
7279 {
7280 /* Strip typedefs from the SCOPE_REF. */
7283 complain);
7286 }
7287 }
7290 }
7292 /* Coerces the remaining template arguments in INNER_ARGS (from
7293 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7294 Returns the coerced argument pack. PARM_IDX is the position of this
7295 parameter in the template parameter list. ARGS is the original
7296 template argument list. */
7297 static tree
7300 tree args,
7301 tree inner_args,
7303 tree new_args,
7305 tree in_decl,
7306 tsubst_flags_t complain)
7307 {
7310 tree packed_args;
7311 tree argument_pack;
7318 {
7319 /* When the template parameter is a non-type template parameter pack
7320 or template template parameter pack whose type or template
7321 parameters use parameter packs, we know exactly how many arguments
7322 we are looking for. Build a vector of the instantiated decls for
7323 these template parameters in PACKED_PARMS. */
7324 /* We can't use make_pack_expansion here because it would interpret a
7325 _DECL as a use rather than a declaration. */
7339 /* If we're doing a partial instantiation of a member template,
7340 verify that all of the types used for the non-type
7341 template parameter pack are, in fact, valid for non-type
7342 template parameters. */
7345 {
7348 {
7352 }
7353 /* We don't know how many args we have yet, just
7354 use the unconverted ones for now. */
7356 }
7359 }
7360 /* Check if we have a placeholder pack, which indicates we're
7361 in the context of a introduction list. In that case we want
7362 to match this pack to the single placeholder. */
7366 {
7369 }
7370 else
7373 /* Convert the remaining arguments, which will be a part of the
7374 parameter pack "parm". */
7376 {
7382 {
7383 /* Once we've packed as many args as we have types, stop. */
7387 /* We don't know how many args we have yet, just
7388 use the unconverted ones for now. */
7390 else
7392 }
7395 {
7398 }
7399 else
7402 in_decl);
7406 }
7410 {
7415 }
7420 else
7421 {
7426 }
7433 }
7435 /* Returns the number of pack expansions in the template argument vector
7436 ARGS. */
7438 static int
7440 {
7445 {
7449 }
7451 }
7453 /* Convert all template arguments to their appropriate types, and
7454 return a vector containing the innermost resulting template
7455 arguments. If any error occurs, return error_mark_node. Error and
7456 warning messages are issued under control of COMPLAIN.
7458 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7459 for arguments not specified in ARGS. Otherwise, if
7460 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7461 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7462 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7463 ARGS. */
7465 static tree
7467 tree args,
7468 tree in_decl,
7469 tsubst_flags_t complain,
7472 {
7474 tree orig_inner_args;
7475 tree inner_args;
7476 tree new_args;
7477 tree new_inner_args;
7481 /* When used as a boolean value, indicates whether this is a
7482 variadic template parameter list. Since it's an int, we can also
7483 subtract it from nparms to get the number of non-variadic
7484 parameters. */
7489 /* Likewise for parameters with default arguments. */
7497 /* Determine if there are any parameter packs or default arguments. */
7499 {
7507 }
7510 /* If there are no parameters that follow a parameter pack, we need to
7511 expand any argument packs so that we can deduce a parameter pack from
7512 some non-packed args followed by an argument pack, as in variadic85.C.
7513 If there are such parameters, we need to leave argument packs intact
7514 so the arguments are assigned properly. This can happen when dealing
7515 with a nested class inside a partial specialization of a class
7516 template, as in variadic92.C, or when deducing a template parameter pack
7517 from a sub-declarator, as in variadic114.C. */
7521 /* Count any pack expansion args. */
7527 && require_all_args
7528 && !variadic_args_p
7529 && (!use_default_args
7532 {
7534 {
7536 {
7540 }
7541 else
7548 }
7551 }
7552 /* We can't pass a pack expansion to a non-pack parameter of an alias
7553 template (DR 1430). */
7557 && variadic_args_p
7559 {
7561 {
7563 {
7569 {
7572 "pack expansion argument for non-pack parameter "
7574 else
7576 "pack expansion argument for non-pack parameter "
7580 }
7581 }
7583 found:;
7584 }
7586 }
7588 /* We need to evaluate the template arguments, even though this
7589 template-id may be nested within a "sizeof". */
7598 {
7599 tree arg;
7600 tree parm;
7602 /* Get the Ith template parameter. */
7606 {
7609 }
7611 /* Calculate the next argument. */
7614 else
7619 {
7620 /* Some arguments will be placed in the
7621 template parameter pack PARM. */
7628 {
7629 /* We don't know how many args we have yet, just use the
7630 unconverted (and still packed) ones for now. */
7634 }
7638 /* Store this argument. */
7640 {
7641 lost++;
7642 /* We are done with all of the arguments. */
7644 }
7645 else
7646 {
7649 }
7652 }
7654 {
7656 {
7657 /* "If every valid specialization of a variadic template
7658 requires an empty template parameter pack, the template is
7659 ill-formed, no diagnostic required." So check that the
7660 pattern works with this parameter. */
7665 in_decl);
7667 {
7671 }
7673 /* Recover from missing typename. */
7677 /* We don't know how many args we have yet, just
7678 use the unconverted ones for now. */
7682 }
7683 }
7685 {
7686 /* There must be a default arg in this case. */
7689 /* The position of the first default template argument,
7690 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7691 Record that. */
7695 }
7696 else
7700 {
7703 }
7705 /* This only occurs if there was an error in the template
7706 parameter list itself (which we would already have
7707 reported) that we are trying to recover from, e.g., a class
7708 template with a parameter list such as
7709 template<typename..., typename>. */
7711 else
7717 lost++;
7719 }
7724 {
7726 {
7731 }
7733 }
7743 }
7745 /* Convert all template arguments to their appropriate types, and
7746 return a vector containing the innermost resulting template
7747 arguments. If any error occurs, return error_mark_node. Error and
7748 warning messages are not issued.
7750 Note that no function argument deduction is performed, and default
7751 arguments are used to fill in unspecified arguments. */
7752 tree
7754 {
7756 }
7758 /* Convert all template arguments to their appropriate type, and
7759 instantiate default arguments as needed. This returns a vector
7760 containing the innermost resulting template arguments, or
7761 error_mark_node if unsuccessful. */
7762 tree
7764 tsubst_flags_t complain)
7765 {
7767 }
7769 /* Like coerce_template_parms. If PARMS represents all template
7770 parameters levels, this function returns a vector of vectors
7771 representing all the resulting argument levels. Note that in this
7772 case, only the innermost arguments are coerced because the
7773 outermost ones are supposed to have been coerced already.
7775 Otherwise, if PARMS represents only (the innermost) vector of
7776 parameters, this function returns a vector containing just the
7777 innermost resulting arguments. */
7779 static tree
7781 tree args,
7782 tree in_decl,
7783 tsubst_flags_t complain,
7786 {
7789 tree coerced_args;
7792 {
7794 tree level;
7800 {
7801 tree l;
7805 require_all_args,
7806 use_default_args);
7807 else
7814 }
7815 }
7816 else
7819 require_all_args,
7820 use_default_args);
7822 }
7824 /* Returns 1 if template args OT and NT are equivalent. */
7826 static int
7828 {
7835 /* For member templates */
7844 {
7861 }
7863 {
7864 /* We get here probably because we are in the middle of substituting
7865 into the pattern of a pack expansion. In that case the
7866 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7867 interested in. So we want to use the initial pack argument for
7868 the comparison. */
7873 }
7875 {
7878 /* Don't treat an alias template specialization with dependent
7879 arguments as equivalent to its underlying type when used as a
7880 template argument; we need them to be distinct so that we
7881 substitute into the specialization arguments at instantiation
7882 time. And aliases can't be equivalent without being ==, so
7883 we don't need to look any deeper. */
7886 else
7888 }
7891 else
7892 {
7893 /* Try to treat a template non-type argument that has been converted
7894 to the parameter type as equivalent to one that hasn't yet. */
7907 }
7908 }
7910 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7911 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7912 NEWARG_PTR with the offending arguments if they are non-NULL. */
7914 int
7917 {
7930 {
7935 {
7941 }
7942 }
7944 }
7946 static void
7948 {
7958 /* We are called both from instantiate_decl, where we've already had a
7959 tinst_level pushed, and instantiate_template, where we haven't.
7960 Compensate. */
7971 else
7980 }
7983 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7984 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7985 documentation for TEMPLATE_ID_EXPR. */
7987 tree
7989 {
7990 tree type;
7998 {
8001 }
8004 {
8006 unknown_type_node,
8008 arglist);
8010 }
8017 }
8019 /* Within the scope of a template class S<T>, the name S gets bound
8020 (in build_self_reference) to a TYPE_DECL for the class, not a
8021 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8022 or one of its enclosing classes, and that type is a template,
8023 return the associated TEMPLATE_DECL. Otherwise, the original
8024 DECL is returned.
8026 Also handle the case when DECL is a TREE_LIST of ambiguous
8027 injected-class-names from different bases. */
8029 tree
8031 {
8035 /* DR 176: A lookup that finds an injected-class-name (10.2
8036 [class.member.lookup]) can result in an ambiguity in certain cases
8037 (for example, if it is found in more than one base class). If all of
8038 the injected-class-names that are found refer to specializations of
8039 the same class template, and if the name is followed by a
8040 template-argument-list, the reference refers to the class template
8041 itself and not a specialization thereof, and is not ambiguous. */
8043 {
8046 {
8052 }
8055 else
8057 }
8063 }
8065 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8066 parameters, find the desired type.
8068 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8070 IN_DECL, if non-NULL, is the template declaration we are trying to
8071 instantiate.
8073 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8074 the class we are looking up.
8076 Issue error and warning messages under control of COMPLAIN.
8078 If the template class is really a local class in a template
8079 function, then the FUNCTION_CONTEXT is the function in which it is
8080 being instantiated.
8082 ??? Note that this function is currently called *twice* for each
8083 template-id: the first time from the parser, while creating the
8084 incomplete type (finish_template_type), and the second type during the
8085 real instantiation (instantiate_template_class). This is surely something
8086 that we want to avoid. It also causes some problems with argument
8087 coercion (see convert_nontype_argument for more information on this). */
8089 static tree
8092 {
8094 tree t;
8097 spec_entry elt;
8098 hashval_t hash;
8101 {
8105 else
8106 {
8113 }
8116 }
8118 {
8121 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8122 an implicit typename for the second A. Deal with it. */
8127 {
8130 }
8131 }
8134 {
8137 }
8139 {
8143 }
8145 {
8148 }
8150 /* Issue an error message if we didn't find a template. */
8152 {
8156 }
8159 /* Make sure it's a user visible template, if it was named by
8160 the user. */
8163 {
8165 {
8169 }
8171 }
8175 /* An alias that just changes the name of a template is equivalent to the
8176 other template, so if any of the arguments are pack expansions, strip
8177 the alias to avoid problems with a pack expansion passed to a non-pack
8178 alias template parameter (DR 1430). */
8183 {
8184 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
8185 template arguments */
8187 tree parm;
8188 tree arglist2;
8189 tree outer;
8193 /* Consider an example where a template template parameter declared as
8195 template <class T, class U = std::allocator<T> > class TT
8197 The template parameter level of T and U are one level larger than
8198 of TT. To proper process the default argument of U, say when an
8199 instantiation `TT<int>' is seen, we need to build the full
8200 arguments containing {int} as the innermost level. Outer levels,
8201 available when not appearing as default template argument, can be
8202 obtained from the arguments of the enclosing template.
8204 Suppose that TT is later substituted with std::vector. The above
8205 instantiation is `TT<int, std::allocator<T> >' with TT at
8206 level 1, and T at level 2, while the template arguments at level 1
8207 becomes {std::vector} and the inner level 2 is {int}. */
8213 {
8214 /* This is an argument of the current template, so we haven't set
8215 DECL_CONTEXT yet. */
8216 tree relevant_template_parms;
8218 /* Parameter levels that are greater than the level of the given
8219 template template parm are irrelevant. */
8226 }
8232 complain,
8242 }
8243 else
8244 {
8246 tree gen_tmpl;
8247 tree type_decl;
8255 /* An error occurred while building the template TEMPL, and a
8256 diagnostic has most certainly been emitted for that
8257 already. Let's propagate that error. */
8266 {
8267 /* We've been given an incomplete set of template arguments.
8268 For example, given:
8270 template <class T> struct S1 {
8271 template <class U> struct S2 {};
8272 template <class U> struct S2<U*> {};
8273 };
8275 we will be called with an ARGLIST of `U*', but the
8276 TEMPLATE will be `template <class T> template
8277 <class U> struct S1<T>::S2'. We must fill in the missing
8278 arguments. */
8279 arglist
8281 arglist);
8283 }
8285 /* Now we should have enough arguments. */
8288 /* From here on, we're only interested in the most general
8289 template. */
8291 /* Calculate the BOUND_ARGS. These will be the args that are
8292 actually tsubst'd into the definition to create the
8293 instantiation. */
8295 complain,
8300 /* We were unable to bind the arguments. */
8303 /* In the scope of a template class, explicit references to the
8304 template class refer to the type of the template, not any
8305 instantiation of it. For example, in:
8307 template <class T> class C { void f(C<T>); }
8309 the `C<T>' is just the same as `C'. Outside of the
8310 class, however, such a reference is an instantiation. */
8314 /* comp_template_args is expensive, check it last. */
8316 arglist))
8319 /* If we already have this specialization, return it. */
8329 /* If the the template's constraints are not satisfied,
8330 then we cannot form a valid type.
8332 Note that the check is deferred until after the hash
8333 lookup. This prevents redundant checks on previously
8334 instantiated specializations. */
8336 {
8338 {
8341 }
8343 }
8347 /* If the deduced arguments are invalid, then the binding
8348 failed. */
8352 complain))
8359 {
8364 }
8374 /* Create the type. */
8376 {
8377 /* The user referred to a specialization of an alias
8378 template represented by GEN_TMPL.
8380 [temp.alias]/2 says:
8382 When a template-id refers to the specialization of an
8383 alias template, it is equivalent to the associated
8384 type obtained by substitution of its
8385 template-arguments for the template-parameters in the
8386 type-id of the alias template. */
8389 /* Note that the call above (by indirectly calling
8390 register_specialization in tsubst_decl) registers the
8391 TYPE_DECL representing the specialization of the alias
8392 template. So next time someone substitutes ARGLIST for
8393 the template parms into the alias template (GEN_TMPL),
8394 she'll get that TYPE_DECL back. */
8398 }
8400 {
8402 {
8413 }
8414 else
8415 {
8416 /* We don't want to call start_enum for this type, since
8417 the values for the enumeration constants may involve
8418 template parameters. And, no one should be interested
8419 in the enumeration constants for such a type. */
8422 }
8426 }
8428 {
8435 /* A local class. Make sure the decl gets registered properly. */
8440 /* This instantiation is another name for the primary
8441 template type. Set the TYPE_CANONICAL field
8442 appropriately. */
8445 /* Some of the template arguments require structural
8446 equality testing, so this template class requires
8447 structural equality testing. */
8449 }
8450 else
8453 /* If we called start_enum or pushtag above, this information
8454 will already be set up. */
8456 {
8463 }
8464 else
8468 {
8474 {
8477 }
8478 }
8482 {
8486 {
8487 tree attributes
8495 }
8496 }
8498 /* Let's consider the explicit specialization of a member
8499 of a class template specialization that is implicitly instantiated,
8500 e.g.:
8501 template<class T>
8502 struct S
8503 {
8504 template<class U> struct M {}; //#0
8505 };
8507 template<>
8508 template<>
8509 struct S<int>::M<char> //#1
8510 {
8511 int i;
8512 };
8513 [temp.expl.spec]/4 says this is valid.
8515 In this case, when we write:
8516 S<int>::M<char> m;
8518 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8519 the one of #0.
8521 When we encounter #1, we want to store the partial instantiation
8522 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8524 For all cases other than this "explicit specialization of member of a
8525 class template", we just want to store the most general template into
8526 the CLASSTYPE_TI_TEMPLATE of M.
8528 This case of "explicit specialization of member of a class template"
8529 only happens when:
8530 1/ the enclosing class is an instantiation of, and therefore not
8531 the same as, the context of the most general template, and
8532 2/ we aren't looking at the partial instantiation itself, i.e.
8533 the innermost arguments are not the same as the innermost parms of
8534 the most general template.
8536 So it's only when 1/ and 2/ happens that we want to use the partial
8537 instantiation of the member template in lieu of its most general
8538 template. */
8542 /* the enclosing class must be an instantiation... */
8545 {
8546 tree partial_inst_args;
8549 partial_inst_args =
8557 use_partial_inst_tmpl =
8558 /*...and we must not be looking at the partial instantiation
8559 itself. */
8561 partial_inst_args);
8562 }
8565 /* This case is easy; there are no member templates involved. */
8567 else
8568 {
8569 /* This is a full instantiation of a member template. Find
8570 the partial instantiation of which this is an instance. */
8572 /* Temporarily reduce by one the number of levels in the ARGLIST
8573 so as to avoid comparing the last set of arguments. */
8577 /* FOUND is either a proper class type, or an alias
8578 template specialization. In the later case, it's a
8579 TYPE_DECL, resulting from the substituting of arguments
8580 for parameters in the TYPE_DECL of the alias template
8581 done earlier. So be careful while getting the template
8582 of FOUND. */
8586 }
8588 // Build template info for the new specialization.
8597 /* Note this use of the partial instantiation so we can check it
8598 later in maybe_process_partial_specialization. */
8605 /* Now that the type has been registered on the instantiations
8606 list, we set up the enumerators. Because the enumeration
8607 constants may involve the enumeration type itself, we make
8608 sure to register the type first, and then create the
8609 constants. That way, doing tsubst_expr for the enumeration
8610 constants won't result in recursive calls here; we'll find
8611 the instantiation and exit above. */
8615 /* If the type makes use of template parameters, the
8616 code that generates debugging information will crash. */
8619 /* Possibly limit visibility based on template args. */
8626 }
8627 }
8629 /* Wrapper for lookup_template_class_1. */
8631 tree
8634 {
8635 tree ret;
8641 }
8643 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
8645 tree
8647 {
8648 /* The type of the expression is NULL_TREE since the template-id could refer
8649 to an explicit or partial specialization. */
8652 /* Except that concepts are always bool. */
8655 }
8657 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8659 tree
8661 {
8665 /* We never want to return a VAR_DECL for a variable concept, since they
8666 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
8680 {
8682 {
8685 }
8687 }
8689 /* If a template-id refers to a specialization of a variable
8690 concept, then the expression is true if and only if the
8691 concept's constraints are satisfied by the given template
8692 arguments.
8694 NOTE: This is an extension of Concepts Lite TS that
8695 allows constraints to be used in expressions. */
8697 {
8700 }
8703 }
8705 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
8706 TARGS template args, and instantiate it if it's not dependent. */
8708 static tree
8710 tsubst_flags_t complain)
8711 {
8714 {
8717 }
8720 }
8722 \f
8723 struct pair_fn_data
8724 {
8725 tree_fn_t fn;
8727 /* True when we should also visit template parameters that occur in
8728 non-deduced contexts. */
8731 };
8733 /* Called from for_each_template_parm via walk_tree. */
8735 static tree
8737 {
8744 #define WALK_SUBTREE(NODE) \
8745 do \
8746 { \
8747 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
8748 pfd->include_nondeduced_p); \
8749 if (result) goto out; \
8750 } \
8751 while (0)
8758 {
8762 /* Fall through. */
8768 else
8778 /* Since we're not going to walk subtrees, we have to do this
8779 explicitly here. */
8781 /* Fall through. */
8784 /* Check the return type. */
8787 /* Check the parameter types. Since default arguments are not
8788 instantiated until they are needed, the TYPE_ARG_TYPES may
8789 contain expressions that involve template parameters. But,
8790 no-one should be looking at them yet. And, once they're
8791 instantiated, they don't contain template parameters, so
8792 there's no point in looking at them then, either. */
8793 {
8794 tree parm;
8799 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8800 want walk_tree walking into them itself. */
8802 }
8818 /* Fall through. */
8830 /* Record template parameters such as `T' inside `TT<T>'. */
8832 /* Fall through. */
8844 /* A template template parameter is encountered. */
8848 /* Already substituted template template parameter */
8853 /* A template-id in a TYPENAME_TYPE might be a deduced context after
8854 partial instantiation. */
8866 /* If there's no type, then this thing must be some expression
8867 involving template parameters. */
8889 }
8891 #undef WALK_SUBTREE
8893 /* We didn't find any template parameters we liked. */
8894 out:
8896 }
8898 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8899 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8900 call FN with the parameter and the DATA.
8901 If FN returns nonzero, the iteration is terminated, and
8902 for_each_template_parm returns 1. Otherwise, the iteration
8903 continues. If FN never returns a nonzero value, the value
8904 returned by for_each_template_parm is 0. If FN is NULL, it is
8905 considered to be the function which always returns 1.
8907 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8908 parameters that occur in non-deduced contexts. When false, only
8909 visits those template parameters that can be deduced. */
8911 static tree
8915 {
8917 tree result;
8919 /* Set up. */
8924 /* Walk the tree. (Conceptually, we would like to walk without
8925 duplicates, but for_each_template_parm_r recursively calls
8926 for_each_template_parm, so we would need to reorganize a fair
8927 bit to use walk_tree_without_duplicates, so we keep our own
8928 visited list.) */
8931 else
8934 for_each_template_parm_r,
8938 /* Clean up. */
8940 {
8943 }
8946 }
8948 /* Returns true if T depends on any template parameter. */
8950 int
8952 {
8982 else
8983 {
8986 }
8991 }
8993 /* Returns true iff current_function_decl is an incompletely instantiated
8994 template. Useful instead of processing_template_decl because the latter
8995 is set to 0 during instantiate_non_dependent_expr. */
8997 bool
8999 {
9008 }
9010 /* Returns true if T depends on any template parameter with level LEVEL. */
9012 bool
9014 {
9017 }
9019 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9020 ill-formed translation unit, i.e. a variable or function that isn't
9021 usable in a constant expression. */
9025 {
9029 }
9031 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9032 neglectable and instantiated from within an erroneous instantiation. */
9034 static bool
9036 {
9047 }
9055 /* We're starting to instantiate D; record the template instantiation context
9056 for diagnostics and to restore it later. */
9058 bool
9060 {
9062 }
9064 /* We're starting to instantiate D; record the template instantiation context
9065 at LOC for diagnostics and to restore it later. */
9067 bool
9069 {
9073 {
9075 "template instantiation depth exceeds maximum of %d"
9077 max_tinst_depth);
9079 }
9081 /* If the current instantiation caused problems, don't let it instantiate
9082 anything else. Do allow deduction substitution and decls usable in
9083 constant expressions. */
9100 }
9102 /* We're done instantiating this template; return to the instantiation
9103 context. */
9105 void
9107 {
9108 /* Restore the filename and line number stashed away when we started
9109 this instantiation. */
9113 }
9115 /* We're instantiating a deferred template; restore the template
9116 instantiation context in which the instantiation was requested, which
9117 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9119 static tree
9121 {
9133 }
9135 /* Returns the TINST_LEVEL which gives the original instantiation
9136 context. */
9140 {
9146 }
9148 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9149 vector of template arguments, as for tsubst.
9151 Returns an appropriate tsubst'd friend declaration. */
9153 static tree
9155 {
9156 tree new_friend;
9161 /* This was a friend declared with an explicit template
9162 argument list, e.g.:
9164 friend void f<>(T);
9166 to indicate that f was a template instantiation, not a new
9167 function declaration. Now, we have to figure out what
9168 instantiation of what template. */
9169 {
9171 tree new_args;
9172 tree tmpl;
9175 /* Friend functions are looked up in the containing namespace scope.
9176 We must enter that scope, to avoid finding member functions of the
9177 current class with same name. */
9192 tsk_none);
9194 }
9198 /* The NEW_FRIEND will look like an instantiation, to the
9199 compiler, but is not an instantiation from the point of view of
9200 the language. For example, we might have had:
9202 template <class T> struct S {
9203 template <class U> friend void f(T, U);
9204 };
9206 Then, in S<int>, template <class U> void f(int, U) is not an
9207 instantiation of anything. */
9213 {
9217 }
9219 /* The mangled name for the NEW_FRIEND is incorrect. The function
9220 is not a template instantiation and should not be mangled like
9221 one. Therefore, we forget the mangling here; we'll recompute it
9222 later if we need it. */
9224 {
9227 }
9230 {
9231 tree old_decl;
9232 tree new_friend_template_info;
9233 tree new_friend_result_template_info;
9234 tree ns;
9237 /* We must save some information from NEW_FRIEND before calling
9238 duplicate decls since that function will free NEW_FRIEND if
9239 possible. */
9241 new_friend_is_defn =
9246 {
9247 /* This declaration is a `primary' template. */
9250 new_friend_result_template_info
9252 }
9253 else
9256 /* Make the init_value nonzero so pushdecl knows this is a defn. */
9260 /* Inside pushdecl_namespace_level, we will push into the
9261 current namespace. However, the friend function should go
9262 into the namespace of the template. */
9272 {
9273 /* This new friend declaration matched an existing
9274 declaration. For example, given:
9276 template <class T> void f(T);
9277 template <class U> class C {
9278 template <class T> friend void f(T) {}
9279 };
9281 the friend declaration actually provides the definition
9282 of `f', once C has been instantiated for some type. So,
9283 old_decl will be the out-of-class template declaration,
9284 while new_friend is the in-class definition.
9286 But, if `f' was called before this point, the
9287 instantiation of `f' will have DECL_TI_ARGS corresponding
9288 to `T' but not to `U', references to which might appear
9289 in the definition of `f'. Previously, the most general
9290 template for an instantiation of `f' was the out-of-class
9291 version; now it is the in-class version. Therefore, we
9292 run through all specialization of `f', adding to their
9293 DECL_TI_ARGS appropriately. In particular, they need a
9294 new set of outer arguments, corresponding to the
9295 arguments for this class instantiation.
9297 The same situation can arise with something like this:
9299 friend void f(int);
9300 template <class T> class C {
9301 friend void f(T) {}
9302 };
9304 when `C<int>' is instantiated. Now, `f(int)' is defined
9305 in the class. */
9308 /* On the other hand, if the in-class declaration does
9309 *not* provide a definition, then we don't want to alter
9310 existing definitions. We can just leave everything
9311 alone. */
9312 ;
9313 else
9314 {
9318 /* Overwrite whatever template info was there before, if
9319 any, with the new template information pertaining to
9320 the declaration. */
9324 {
9325 /* We should have called reregister_specialization in
9326 duplicate_decls. */
9331 /* Instantiate it if the global has already been used. */
9335 }
9336 else
9337 {
9338 tree t;
9340 /* Indicate that the old function template is a partial
9341 instantiation. */
9349 /* Reassign any specializations already in the hash table
9350 to the new more general template, and add the
9351 additional template args. */
9355 {
9357 spec_entry elt;
9369 register_specialization
9372 }
9374 }
9375 }
9377 /* The information from NEW_FRIEND has been merged into OLD_DECL
9378 by duplicate_decls. */
9380 }
9381 }
9382 else
9383 {
9387 /* In the code
9388 template <class T> class C {
9389 template <class U> friend void C1<U>::f (); // case 1
9390 friend void C2<T>::f (); // case 2
9391 };
9392 we only need to make sure CONTEXT is a complete type for
9393 case 2. To distinguish between the two cases, we note that
9394 CONTEXT of case 1 remains dependent type after tsubst while
9395 this isn't true for case 2. */
9405 {
9407 /* do_friend adds the TEMPLATE_DECL for any member friend
9408 template even if it isn't a member template, i.e.
9409 template <class T> friend A<T>::f();
9410 Look through it in that case. */
9414 /* Check to see that the declaration is really present, and,
9415 possibly obtain an improved declaration. */
9420 }
9421 }
9424 }
9426 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9427 template arguments, as for tsubst.
9429 Returns an appropriate tsubst'd friend type or error_mark_node on
9430 failure. */
9432 static tree
9434 {
9435 tree friend_type;
9436 tree tmpl;
9437 tree context;
9440 {
9443 }
9448 {
9451 else
9453 }
9455 /* Look for a class template declaration. We look for hidden names
9456 because two friend declarations of the same template are the
9457 same. For example, in:
9459 struct A {
9460 template <typename> friend class F;
9461 };
9462 template <typename> struct B {
9463 template <typename> friend class F;
9464 };
9466 both F templates are the same. */
9470 /* But, if we don't find one, it might be because we're in a
9471 situation like this:
9473 template <class T>
9474 struct S {
9475 template <class U>
9476 friend struct S;
9477 };
9479 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9480 for `S<int>', not the TEMPLATE_DECL. */
9482 {
9485 }
9488 {
9489 /* The friend template has already been declared. Just
9490 check to see that the declarations match, and install any new
9491 default parameters. We must tsubst the default parameters,
9492 of course. We only need the innermost template parameters
9493 because that is all that redeclare_class_template will look
9494 at. */
9497 {
9498 tree parms;
9499 location_t saved_input_location;
9509 }
9512 }
9513 else
9514 {
9515 /* The friend template has not already been declared. In this
9516 case, the instantiation of the template class will cause the
9517 injection of this template into the global scope. */
9522 /* The new TMPL is not an instantiation of anything, so we
9523 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
9524 the new type because that is supposed to be the corresponding
9525 template decl, i.e., TMPL. */
9532 /* Inject this template into the global scope. */
9534 }
9537 {
9540 else
9542 }
9545 }
9547 /* Returns zero if TYPE cannot be completed later due to circularity.
9548 Otherwise returns one. */
9550 static int
9552 {
9562 else
9564 }
9569 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
9570 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
9572 static tree
9575 {
9584 {
9591 clauses
9595 else
9597 }
9598 /* If the first attribute argument is an identifier, don't
9599 pass it through tsubst. Attributes like mode, format,
9600 cleanup and several target specific attributes expect it
9601 unmodified. */
9603 {
9604 tree chain
9609 }
9611 {
9612 /* An attribute pack expansion. */
9619 {
9623 }
9625 }
9626 else
9633 }
9635 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
9636 unchanged or a new TREE_LIST chain. */
9638 static tree
9641 {
9646 {
9650 }
9654 {
9657 {
9662 do
9666 }
9667 }
9670 }
9672 /* Apply any attributes which had to be deferred until instantiation
9673 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
9674 ARGS, COMPLAIN, IN_DECL are as tsubst. */
9676 static void
9679 {
9681 tree t;
9686 {
9690 }
9693 {
9697 }
9698 else
9702 {
9707 {
9710 {
9714 do
9717 }
9718 else
9720 }
9723 }
9724 }
9726 /* Perform (or defer) access check for typedefs that were referenced
9727 from within the template TMPL code.
9728 This is a subroutine of instantiate_decl and instantiate_class_template.
9729 TMPL is the template to consider and TARGS is the list of arguments of
9730 that template. */
9732 static void
9734 {
9735 location_t saved_location;
9746 {
9758 /* Make access check error messages point to the location
9759 of the use of the typedef. */
9763 tf_warning_or_error);
9764 }
9766 }
9768 static tree
9770 {
9772 tree typedecl;
9773 tree pbinfo;
9774 tree base_list;
9776 tree fn_context;
9785 /* Figure out which template is being instantiated. */
9789 /* Determine what specialization of the original template to
9790 instantiate. */
9793 {
9796 }
9798 {
9799 /* This TYPE is actually an instantiation of a partial
9800 specialization. We replace the innermost set of ARGS with
9801 the arguments appropriate for substitution. For example,
9802 given:
9804 template <class T> struct S {};
9805 template <class T> struct S<T*> {};
9807 and supposing that we are instantiating S<int*>, ARGS will
9808 presently be {int*} -- but we need {int}. */
9811 }
9812 else
9813 {
9816 }
9818 /* If the template we're instantiating is incomplete, then clearly
9819 there's nothing we can do. */
9823 /* If we've recursively instantiated too many templates, stop. */
9827 /* Now we're really doing the instantiation. Mark the type as in
9828 the process of being defined. */
9831 /* We may be in the middle of deferred access check. Disable
9832 it now. */
9839 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9844 else
9845 {
9848 }
9849 /* Use #pragma pack from the template context. */
9855 /* Set the input location to the most specialized template definition.
9856 This is needed if tsubsting causes an error. */
9868 {
9871 /* Adjust visibility for template arguments. */
9873 }
9879 /* We should never instantiate a nested class before its enclosing
9880 class; we need to look up the nested class by name before we can
9881 instantiate it, and that lookup should instantiate the enclosing
9882 class. */
9888 {
9889 tree pbase_binfo;
9890 tree pushed_scope;
9893 /* We must enter the scope containing the type, as that is where
9894 the accessibility of types named in dependent bases are
9895 looked up from. */
9898 /* Substitute into each of the bases to determine the actual
9899 basetypes. */
9901 {
9902 tree base;
9908 {
9909 expanded_bases =
9916 }
9919 {
9921 /* Extract the already-expanded base class. */
9923 else
9924 /* Substitute to figure out the base class. */
9926 NULL_TREE);
9934 }
9935 }
9937 /* The list is now in reverse order; correct that. */
9942 }
9943 /* Now call xref_basetypes to set up all the base-class
9944 information. */
9952 /* Now that our base classes are set up, enter the scope of the
9953 class, so that name lookups into base classes, etc. will work
9954 correctly. This is precisely analogous to what we do in
9955 begin_class_definition when defining an ordinary non-template
9956 class, except we also need to push the enclosing classes. */
9959 /* Now members are processed in the order of declaration. */
9962 {
9966 {
9968 {
9969 /* Build new CLASSTYPE_NESTED_UTDS. */
9971 tree newtag;
9977 /* If the member is a class template, then -- even after
9978 substitution -- there may be dependent types in the
9979 template argument list for the class. We increment
9980 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9981 that function will assume that no types are dependent
9982 when outside of a template. */
9992 {
9996 /* Unfortunately, lookup_template_class sets
9997 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9998 instantiation (i.e., for the type of a member
9999 template class nested within a template class.)
10000 This behavior is required for
10001 maybe_process_partial_specialization to work
10002 correctly, but is not accurate in this case;
10003 the TAG is not an instantiation of anything.
10004 (The corresponding TEMPLATE_DECL is an
10005 instantiation, but the TYPE is not.) */
10008 /* Now, we call pushtag to put this NEWTAG into the scope of
10009 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10010 pushtag calling push_template_decl. We don't have to do
10011 this for enums because it will already have been done in
10012 tsubst_enum. */
10016 }
10017 }
10019 {
10020 /* Build new TYPE_METHODS. */
10021 tree r;
10030 /* Instantiate members marked with attribute used. */
10036 }
10039 /* A closure type for a lambda in a default argument for a
10040 member template. Ignore it; it will be instantiated with
10042 else
10043 {
10044 /* Build new TYPE_FIELDS. */
10046 {
10047 tree condition;
10050 condition =
10060 }
10062 {
10063 tree r;
10067 /* The file and line for this declaration, to
10068 assist in error message reporting. Since we
10069 called push_tinst_level above, we don't need to
10070 restore these. */
10080 {
10081 /* A capture pack became multiple fields. */
10084 }
10087 {
10091 {
10092 /* In [temp.inst]:
10094 [t]he initialization (and any associated
10095 side-effects) of a static data member does
10096 not occur unless the static data member is
10097 itself used in a way that requires the
10098 definition of the static data member to
10099 exist.
10101 Therefore, we do not substitute into the
10102 initialized for the static data member here. */
10103 finish_static_data_member_decl
10109 /* Instantiate members marked with attribute used. */
10112 }
10114 {
10115 /* Determine whether R has a valid type and can be
10116 completed later. If R is invalid, then its type
10117 is replaced by error_mark_node. */
10126 {
10127 /* Flexible array mmembers of elements
10128 of complete type have an incomplete type
10129 and that's okay. */
10130 }
10132 {
10135 }
10136 }
10138 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10139 such a thing will already have been added to the field
10140 list by tsubst_enum in finish_member_declaration in the
10141 CLASSTYPE_NESTED_UTDS case above. */
10145 {
10148 }
10149 }
10150 }
10151 }
10152 }
10153 else
10154 {
10157 {
10158 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10164 {
10165 /* template <class T> friend class C; */
10168 }
10170 {
10171 /* template <class T> friend class C::D; */
10177 }
10180 {
10181 /* This could be either
10183 friend class T::C;
10185 when dependent_type_p is false or
10187 template <class U> friend class T::C;
10189 otherwise. */
10190 /* Bump processing_template_decl in case this is something like
10191 template <class T> friend struct A<T>::B. */
10198 }
10201 {
10202 /* friend class C;
10204 where C hasn't been declared yet. Let's lookup name
10205 from namespace scope directly, bypassing any name that
10206 come from dependent base class. */
10209 /* The call to xref_tag_from_type does injection for friend
10210 classes. */
10212 friend_type =
10216 }
10218 /* friend class C<T>; */
10221 /* Otherwise it's
10223 friend class C;
10225 where C is already declared or
10227 friend class C<int>;
10229 We don't have to do anything in these cases. */
10232 /* Trick make_friend_class into realizing that the friend
10233 we're adding is a template, not an ordinary class. It's
10234 important that we use make_friend_class since it will
10235 perform some error-checking and output cross-reference
10236 information. */
10244 }
10245 else
10246 {
10247 /* Build new DECL_FRIENDLIST. */
10248 tree r;
10250 /* The file and line for this declaration, to
10251 assist in error message reporting. Since we
10252 called push_tinst_level above, we don't need to
10253 restore these. */
10257 {
10260 }
10265 {
10268 }
10269 }
10270 }
10271 }
10274 {
10275 /* Restore these before substituting into the lambda capture
10276 initializers. */
10279 }
10282 {
10285 {
10288 {
10289 /* Set function_depth to avoid garbage collection. */
10293 }
10295 /* We need to instantiate the capture list from the template
10296 after we've instantiated the closure members, but before we
10297 consider adding the conversion op. Also keep any captures
10298 that may have been added during instantiation of the op(). */
10300 tree tmpl_cap
10309 }
10310 else
10312 }
10314 /* Set the file and line number information to whatever is given for
10315 the class itself. This puts error messages involving generated
10316 implicit functions at a predictable point, and the same point
10317 that would be used for non-template classes. */
10324 /* We don't instantiate default arguments for member functions. 14.7.1:
10326 The implicit instantiation of a class template specialization causes
10327 the implicit instantiation of the declarations, but not of the
10328 definitions or default arguments, of the class member functions,
10329 member classes, static data members and member templates.... */
10331 /* Some typedefs referenced from within the template code need to be access
10332 checked at template instantiation time, i.e now. These types were
10333 added to the template at parsing time. Let's get those and perform
10334 the access checks then. */
10344 /* The vtable for a template class can be emitted in any translation
10345 unit in which the class is instantiated. When there is no key
10346 method, however, finish_struct_1 will already have added TYPE to
10347 the keyed_classes list. */
10352 }
10354 /* Wrapper for instantiate_class_template_1. */
10356 tree
10358 {
10359 tree ret;
10364 }
10366 static tree
10368 {
10369 tree r;
10375 else
10376 {
10383 }
10385 }
10387 /* Given a function parameter pack TMPL_PARM and some function parameters
10388 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10389 and set *SPEC_P to point at the next point in the list. */
10391 tree
10393 {
10394 /* Collect all of the extra "packed" parameters into an
10395 argument pack. */
10396 tree parmvec;
10397 tree parmtypevec;
10408 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10413 {
10416 }
10418 /* Build the argument packs. */
10425 }
10427 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10428 NONTYPE_ARGUMENT_PACK. */
10430 static tree
10432 {
10434 }
10436 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10437 pack expansion with no extra args, 2 if it has extra args, or 0
10438 if it is not a pack expansion. */
10440 static int
10442 {
10448 /* A decl pack is itself an expansion. */
10455 }
10458 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10460 static tree
10462 {
10469 }
10471 /* This is a subroutine of tsubst_pack_expansion.
10473 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10474 mechanism to store the (non complete list of) arguments of the
10475 substitution and return a non substituted pack expansion, in order
10476 to wait for when we have enough arguments to really perform the
10477 substitution. */
10479 static bool
10483 {
10484 /* If one pack has an expansion and another pack has a normal
10485 argument or if one pack has an empty argument and an another
10486 one hasn't then tsubst_pack_expansion cannot perform the
10487 substitution and need to fall back on the
10488 PACK_EXPANSION_EXTRA mechanism. */
10496 {
10499 parm_pack;
10501 {
10506 /* We can't substitute a pack expansion with extra args into
10507 our pattern. */
10511 else
10513 }
10517 }
10519 }
10521 /* [temp.variadic]/6 says that:
10523 The instantiation of a pack expansion [...]
10524 produces a list E1,E2, ..., En, where N is the number of elements
10525 in the pack expansion parameters.
10527 This subroutine of tsubst_pack_expansion produces one of these Ei.
10529 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
10530 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
10531 PATTERN, and each TREE_VALUE is its corresponding argument pack.
10532 INDEX is the index 'i' of the element Ei to produce. ARGS,
10533 COMPLAIN, and IN_DECL are the same parameters as for the
10534 tsubst_pack_expansion function.
10536 The function returns the resulting Ei upon successful completion,
10537 or error_mark_node.
10539 Note that this function possibly modifies the ARGS parameter, so
10540 it's the responsibility of the caller to restore it. */
10542 static tree
10544 tree parm_packs,
10546 tree args /* This parm gets
10548 tsubst_flags_t complain,
10549 tree in_decl)
10550 {
10551 tree t;
10554 /* For each parameter pack, change the substitution of the parameter
10555 pack to the ith argument in its argument pack, then expand the
10556 pattern. */
10558 {
10563 ith_elem_is_expansion |=
10566 /* Select the Ith argument from the pack. */
10569 {
10571 {
10576 }
10577 else
10579 }
10580 else
10581 {
10586 {
10588 /* Update the corresponding argument. */
10590 }
10591 else
10592 /* Re-use the ARGUMENT_PACK_SELECT. */
10594 }
10596 }
10598 /* Substitute into the PATTERN with the (possibly altered)
10599 arguments. */
10601 /* Expanding a fixed parameter pack from
10602 coerce_template_parameter_pack. */
10607 {
10610 else
10613 }
10617 else
10620 /* If the Ith argument pack element is a pack expansion, then
10621 the Ith element resulting from the substituting is going to
10622 be a pack expansion as well. */
10627 }
10629 /* When the unexpanded parameter pack in a fold expression expands to an empty
10630 sequence, the value of the expression is as follows; the program is
10631 ill-formed if the operator is not listed in this table.
10633 && true
10634 || false
10635 , void() */
10637 tree
10639 {
10643 {
10652 }
10658 }
10660 /* Given a fold-expression T and a current LEFT and RIGHT operand,
10661 form an expression that combines the two terms using the
10662 operator of T. */
10664 static tree
10666 {
10670 // Handle compound assignment operators.
10675 {
10685 complain);
10686 }
10687 }
10689 /* Substitute ARGS into the pack of a fold expression T. */
10693 {
10695 }
10697 /* Substitute ARGS into the pack of a fold expression T. */
10701 {
10703 }
10705 /* Expand a PACK of arguments into a grouped as left fold.
10706 Given a pack containing elements A0, A1, ..., An and an
10707 operator @, this builds the expression:
10709 ((A0 @ A1) @ A2) ... @ An
10711 Note that PACK must not be empty.
10713 The operator is defined by the original fold expression T. */
10715 static tree
10717 {
10720 {
10723 }
10725 }
10727 /* Substitute into a unary left fold expression. */
10729 static tree
10731 tree in_decl)
10732 {
10738 else
10740 }
10742 /* Substitute into a binary left fold expression.
10744 Do ths by building a single (non-empty) vector of argumnts and
10745 building the expression from those elements. */
10747 static tree
10749 tree in_decl)
10750 {
10764 }
10766 /* Expand a PACK of arguments into a grouped as right fold.
10767 Given a pack containing elementns A0, A1, ..., and an
10768 operator @, this builds the expression:
10770 A0@ ... (An-2 @ (An-1 @ An))
10772 Note that PACK must not be empty.
10774 The operator is defined by the original fold expression T. */
10776 tree
10778 {
10779 // Build the expression.
10783 {
10786 }
10788 }
10790 /* Substitute into a unary right fold expression. */
10792 static tree
10794 tree in_decl)
10795 {
10801 else
10803 }
10805 /* Substitute into a binary right fold expression.
10807 Do ths by building a single (non-empty) vector of arguments and
10808 building the expression from those elements. */
10810 static tree
10812 tree in_decl)
10813 {
10828 }
10831 /* Substitute ARGS into T, which is an pack expansion
10832 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
10833 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
10834 (if only a partial substitution could be performed) or
10835 ERROR_MARK_NODE if there was an error. */
10836 tree
10838 tree in_decl)
10839 {
10840 tree pattern;
10844 tree result;
10852 /* Add in any args remembered from an earlier partial instantiation. */
10857 /* Determine the argument packs that will instantiate the parameter
10858 packs used in the expansion expression. While we're at it,
10859 compute the number of arguments to be expanded and make sure it
10860 is consistent. */
10863 {
10870 {
10874 else
10877 }
10879 {
10880 /* We know we have correct local_specializations if this
10881 expansion is at function scope, or if we're dealing with a
10882 local parameter in a requires expression; for the latter,
10883 tsubst_requires_expr set it up appropriately. */
10886 else
10887 /* We can't rely on local_specializations for a parameter
10888 name used later in a function declaration (such as in a
10889 late-specified return type). Even if it exists, it might
10890 have the wrong value for a recursive call. */
10894 {
10895 /* This parameter pack was used in an unevaluated context. Just
10896 make a dummy decl, since it's only used for its type. */
10899 /* Partial instantiation of the parm_pack, we can't build
10900 up an argument pack yet. */
10902 else
10904 }
10905 }
10908 else
10909 {
10915 }
10922 /* This can only happen if we forget to expand an argument
10923 pack somewhere else. Just return an error, silently. */
10924 {
10928 }
10931 {
10935 /* Don't bother trying to do a partial substitution with
10936 incomplete packs; we'll try again after deduction. */
10943 {
10949 pattern);
10950 else
10953 pattern);
10955 }
10957 /* Keep track of the parameter packs and their corresponding
10958 argument packs. */
10961 }
10962 else
10963 {
10964 /* We can't substitute for this parameter pack. We use a flag as
10965 well as the missing_level counter because function parameter
10966 packs don't have a level. */
10969 }
10970 }
10972 /* If the expansion is just T..., return the matching argument pack, unless
10973 we need to call convert_from_reference on all the elements. This is an
10974 important optimization; see c++/68422. */
10977 {
10979 /* Types need no adjustment, nor does sizeof..., and if we still have
10980 some pack expansion args we won't do anything yet. */
10985 /* Also optimize expression pack expansions if we can tell that the
10986 elements won't have reference type. */
10992 /* Otherwise use the normal path so we get convert_from_reference. */
10993 }
10995 /* We cannot expand this expansion expression, because we don't have
10996 all of the argument packs we need. */
10998 {
10999 /* We got some full packs, but we can't substitute them in until we
11000 have values for all the packs. So remember these until then. */
11005 }
11007 {
11008 /* There were no real arguments, we're just replacing a parameter
11009 pack with another version of itself. Substitute into the
11010 pattern and return a PACK_EXPANSION_*. The caller will need to
11011 deal with that. */
11015 else
11019 }
11024 {
11025 /* We're in a late-specified return type, so create our own local
11026 specializations map; the current map is either NULL or (in the
11027 case of recursive unification) might have bindings that we don't
11028 want to use or alter. */
11031 }
11033 /* For each argument in each argument pack, substitute into the
11034 pattern. */
11038 {
11040 i,
11042 in_decl);
11045 {
11048 }
11049 }
11051 /* Update ARGS to restore the substitution from parameter packs to
11052 their argument packs. */
11054 {
11060 else
11061 {
11069 /* Update the corresponding argument. */
11073 else
11075 }
11076 }
11079 {
11082 }
11085 }
11087 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11088 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11089 parameter packs; all parms generated from a function parameter pack will
11090 have the same DECL_PARM_INDEX. */
11092 tree
11094 {
11096 tree patparm;
11099 {
11105 }
11106 else
11107 {
11112 }
11115 }
11117 /* Make an argument pack out of the TREE_VEC VEC. */
11119 static tree
11121 {
11122 tree pack;
11126 else
11127 {
11131 }
11134 }
11136 /* Return an exact copy of template args T that can be modified
11137 independently. */
11139 static tree
11141 {
11149 {
11154 }
11160 }
11162 /* Substitute ARGS into the vector or list of template arguments T. */
11164 static tree
11166 {
11178 {
11180 tree new_arg;
11185 {
11186 /* Substitute into an expansion expression. */
11190 /* Add to the expanded length adjustment the number of
11191 expanded arguments. We subtract one from this
11192 measurement, because the argument pack expression
11193 itself is already counted as 1 in
11194 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11195 the argument pack is empty. */
11197 }
11199 {
11200 /* Substitute into each of the arguments. */
11206 new_arg,
11220 }
11221 }
11222 else
11231 }
11236 /* Make space for the expanded arguments coming from template
11237 argument packs. */
11239 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11240 arguments for a member template.
11241 In that case each TREE_VEC in ORIG_T represents a level of template
11242 arguments, and ORIG_T won't carry any non defaulted argument count.
11243 It will rather be the nested TREE_VECs that will carry one.
11244 In other words, ORIG_T carries a non defaulted argument count only
11245 if it doesn't contain any nested TREE_VEC. */
11247 {
11251 }
11253 {
11257 {
11260 /* Now expand the template argument pack "in place". */
11263 }
11264 else
11265 {
11267 out++;
11268 }
11269 }
11272 }
11274 /* Return the result of substituting ARGS into the template parameters
11275 given by PARMS. If there are m levels of ARGS and m + n levels of
11276 PARMS, then the result will contain n levels of PARMS. For
11277 example, if PARMS is `template <class T> template <class U>
11278 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11279 result will be `template <int*, double, class V>'. */
11281 static tree
11283 {
11287 /* When substituting into a template, we must set
11288 PROCESSING_TEMPLATE_DECL as the template parameters may be
11289 dependent if they are based on one-another, and the dependency
11290 predicates are short-circuit outside of templates. */
11297 {
11298 tree new_vec =
11303 {
11304 tree tuple;
11316 }
11322 }
11327 }
11329 /* Return the result of substituting ARGS into one template parameter
11330 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11331 parameter and which TREE_PURPOSE is the default argument of the
11332 template parameter. */
11334 static tree
11336 {
11357 }
11359 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11360 type T. If T is not an aggregate or enumeration type, it is
11361 handled as if by tsubst. IN_DECL is as for tsubst. If
11362 ENTERING_SCOPE is nonzero, T is the context for a template which
11363 we are presently tsubst'ing. Return the substituted value. */
11365 static tree
11367 tree args,
11368 tsubst_flags_t complain,
11369 tree in_decl,
11371 {
11376 {
11381 /* Else fall through. */
11385 {
11386 tree argvec;
11387 tree context;
11388 tree r;
11392 /* In "sizeof(X<I>)" we need to evaluate "I". */
11398 /* First, determine the context for the type we are looking
11399 up. */
11402 {
11405 /* If context is a nested class inside a class template,
11406 it may still need to be instantiated (c++/33959). */
11408 }
11410 /* Then, figure out what arguments are appropriate for the
11411 type we are trying to find. For example, given:
11413 template <class T> struct S;
11414 template <class T, class U> void f(T, U) { S<U> su; }
11416 and supposing that we are instantiating f<int, double>,
11417 then our ARGS will be {int, double}, but, when looking up
11418 S we only want {double}. */
11423 else
11424 {
11428 }
11434 }
11435 else
11436 /* This is not a template type, so there's nothing to do. */
11441 }
11442 }
11444 /* Substitute into the default argument ARG (a default argument for
11445 FN), which has the indicated TYPE. */
11447 tree
11449 {
11454 /* This can happen in invalid code. */
11458 /* This default argument came from a template. Instantiate the
11459 default argument here, not in tsubst. In the case of
11460 something like:
11462 template <class T>
11463 struct S {
11464 static T t();
11465 void f(T = t());
11466 };
11468 we must be careful to do name lookup in the scope of S<T>,
11469 rather than in the current class. */
11471 /* The "this" pointer is not valid in a default argument. */
11473 {
11478 }
11481 /* The default argument expression may cause implicitly defined
11482 member functions to be synthesized, which will result in garbage
11483 collection. We must treat this situation as if we were within
11484 the body of function so as to avoid collecting live data on the
11485 stack. */
11493 /* Restore the "this" pointer. */
11495 {
11498 }
11505 /* Make sure the default argument is reasonable. */
11511 }
11513 /* Substitute into all the default arguments for FN. */
11515 static void
11517 {
11518 tree arg;
11519 tree tmpl_args;
11523 /* If this function is not yet instantiated, we certainly don't need
11524 its default arguments. */
11527 /* Don't do this again for clones. */
11532 arg;
11538 complain);
11539 }
11541 /* Substitute the ARGS into the T, which is a _DECL. Return the
11542 result of the substitution. Issue error and warning messages under
11543 control of COMPLAIN. */
11545 static tree
11547 {
11548 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
11549 location_t saved_loc;
11554 /* Set the filename and linenumber to improve error-reporting. */
11559 {
11561 {
11562 /* We can get here when processing a member function template,
11563 member class template, or template template parameter. */
11565 tree spec;
11566 tree tmpl_args;
11567 tree full_args;
11570 {
11571 /* Template template parameter is treated here. */
11575 /* If we get a real template back, return it. This can happen in
11576 the context of most_specialized_partial_spec. */
11579 else
11580 /* The new TEMPLATE_DECL was built in
11581 reduce_template_parm_level. */
11584 }
11586 /* We might already have an instance of this template.
11587 The ARGS are for the surrounding class type, so the
11588 full args contain the tsubst'd args for the context,
11589 plus the innermost args from the template decl. */
11593 /* Because this is a template, the arguments will still be
11594 dependent, even after substitution. If
11595 PROCESSING_TEMPLATE_DECL is not set, the dependency
11596 predicates will short-circuit. */
11604 /* If this is a default template template argument,
11605 tsubst might not have changed anything. */
11612 {
11615 }
11617 /* Make a new template decl. It will be similar to the
11618 original, but will record the current template arguments.
11619 We also create a new function declaration, which is just
11620 like the old one, but points to this new template, rather
11621 than the old one. */
11626 // Build new template info linking to the original template decl.
11631 {
11632 tree new_type;
11640 /* For a partial specialization, we need to keep pointing to
11641 the primary template. */
11647 }
11648 else
11649 {
11650 tree new_decl;
11662 }
11668 /* The template parameters for this new template are all the
11669 template parameters for the old template, except the
11670 outermost level of parameters. */
11673 complain);
11679 /* Record this non-type partial instantiation. */
11683 }
11687 {
11688 tree ctx;
11691 tree gen_tmpl;
11692 tree type;
11697 /* Nobody should be tsubst'ing into non-template functions. */
11701 {
11702 tree spec;
11705 /* If T is not dependent, just return it. We have to
11706 increment PROCESSING_TEMPLATE_DECL because
11707 value_dependent_expression_p assumes that nothing is
11708 dependent when PROCESSING_TEMPLATE_DECL is zero. */
11715 /* Calculate the most general template of which R is a
11716 specialization, and the complete set of arguments used to
11717 specialize R. */
11720 (DECL_TEMPLATE_RESULT
11726 /* Check to see if we already have this specialization. */
11731 {
11734 }
11736 /* We can see more levels of arguments than parameters if
11737 there was a specialization of a member template, like
11738 this:
11740 template <class T> struct S { template <class U> void f(); }
11741 template <> template <class U> void S<int>::f(U);
11743 Here, we'll be substituting into the specialization,
11744 because that's where we can find the code we actually
11745 want to generate, but we'll have enough arguments for
11746 the most general template.
11748 We also deal with the peculiar case:
11750 template <class T> struct S {
11751 template <class U> friend void f();
11752 };
11753 template <class U> void f() {}
11754 template S<int>;
11755 template void f<double>();
11757 Here, the ARGS for the instantiation of will be {int,
11758 double}. But, we only need as many ARGS as there are
11759 levels of template parameters in CODE_PATTERN. We are
11760 careful not to get fooled into reducing the ARGS in
11761 situations like:
11763 template <class T> struct S { template <class U> void f(U); }
11764 template <class T> template <> void S<T>::f(int) {}
11766 which we can spot because the pattern will be a
11767 specialization in this case. */
11769 parms_depth =
11774 }
11775 else
11776 {
11777 /* This special case arises when we have something like this:
11779 template <class T> struct S {
11780 friend void f<int>(int, double);
11781 };
11783 Here, the DECL_TI_TEMPLATE for the friend declaration
11784 will be an IDENTIFIER_NODE. We are being called from
11785 tsubst_friend_function, and we want only to create a
11786 new decl (R) with appropriate types so that we can call
11787 determine_specialization. */
11789 }
11792 {
11795 else
11799 }
11800 else
11801 {
11804 }
11809 /* If we hit excessive deduction depth, the type is bogus even if
11810 it isn't error_mark_node, so don't build a decl. */
11814 /* We do NOT check for matching decls pushed separately at this
11815 point, as they may not represent instantiations of this
11816 template, and in any case are considered separate under the
11817 discrete model. */
11821 /* Clear out the mangled name and RTL for the instantiation. */
11824 /* Leave DECL_INITIAL set on deleted instantiations. */
11829 /* OpenMP UDRs have the only argument a reference to the declared
11830 type. We want to diagnose if the declared type is a reference,
11831 which is invalid, but as references to references are usually
11832 quietly merged, diagnose it here. */
11834 {
11835 tree argtype
11840 "reference type %qT in "
11844 argtype);
11845 }
11848 /* Type-conversion operator. Reconstruct the name, in
11849 case it's the name of one of the template's parameters. */
11859 /* If this is an instantiation of a function with internal
11860 linkage, we already know what object file linkage will be
11861 assigned to the instantiation. */
11870 /* We'll re-clone as appropriate in instantiate_template. */
11873 /* If we aren't complaining now, return on error before we register
11874 the specialization so that we'll complain eventually. */
11880 /* When instantiating a constrained member, substitute
11881 into the constraints to create a new constraint. */
11884 {
11887 }
11889 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
11890 this in the special friend case mentioned above where
11891 GEN_TMPL is NULL. */
11893 {
11898 tree new_r
11901 /* We instantiated this while substituting into
11902 the type earlier (template/friend54.C). */
11905 /* We're not supposed to instantiate default arguments
11906 until they are called, for a template. But, for a
11907 declaration like:
11909 template <class T> void f ()
11910 { extern void g(int i = T()); }
11912 we should do the substitution when the template is
11913 instantiated. We handle the member function case in
11914 instantiate_class_template since the default arguments
11915 might refer to other members of the class. */
11920 }
11921 else
11924 /* Copy the list of befriending classes. */
11928 {
11932 in_decl);
11933 }
11936 {
11942 /* If this is an instantiation of a member template, clone it.
11943 If it isn't, that'll be handled by
11944 clone_constructors_and_destructors. */
11947 }
11958 /* Possibly limit visibility based on template args. */
11961 {
11965 }
11973 }
11977 {
11985 {
11986 /* If there is a local specialization that isn't a
11987 parameter pack, it means that we're doing a "simple"
11988 substitution from inside tsubst_pack_expansion. Just
11989 return the local specialization (which will be a single
11990 parm). */
11997 /* Expand the TYPE_PACK_EXPANSION that provides the types for
11998 the parameters in this function parameter pack. */
12002 {
12005 /* Zero-length parameter packs are boring. Just substitute
12006 into the chain. */
12010 }
12011 else
12012 {
12013 /* All we did was update the type. Make a note of that. */
12016 }
12017 }
12019 /* Loop through all of the parameters we'll build. When T is
12020 a function parameter pack, LEN is the number of expanded
12021 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12024 {
12031 /* We're on the Ith parameter of the function parameter
12032 pack. */
12033 {
12034 /* Get the Ith type. */
12037 /* Rename the parameter to include the index. */
12040 }
12042 /* We're dealing with a normal parameter. */
12050 {
12053 else
12056 }
12066 /* Keep track of the first new parameter we
12067 generate. That's what will be returned to the
12068 caller. */
12072 /* Build a proper chain of parameters when substituting
12073 into a function parameter pack. */
12076 }
12078 /* If cp_unevaluated_operand is set, we're just looking for a
12079 single dummy parameter, so don't keep going. */
12084 /* FIRST_R contains the start of the chain we've built. */
12086 }
12090 {
12097 {
12098 /* This field is a lambda capture pack. Return a TREE_VEC of
12099 the expanded fields to instantiate_class_template_1 and
12100 store them in the specializations hash table as a
12101 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12105 {
12108 }
12109 else
12110 {
12111 /* All we did was update the type. Make a note of that. */
12114 }
12115 }
12118 {
12121 {
12125 }
12135 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12136 non-bit-fields DECL_INITIAL is a non-static data member
12137 initializer, which gets deferred instantiation. */
12143 {
12144 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12145 NSDMI in perform_member_init. Still set DECL_INITIAL
12146 so that we know there is one. */
12151 }
12152 /* We don't have to set DECL_CONTEXT here; it is set by
12153 finish_member_declaration. */
12161 }
12164 {
12172 }
12173 }
12177 /* We reach here only for member using decls. We also need to check
12178 uses_template_parms because DECL_DEPENDENT_P is not set for a
12179 using-declaration that designates a member of the current
12180 instantiation (c++/53549). */
12183 {
12190 else
12191 {
12194 }
12195 }
12196 else
12197 {
12200 }
12205 {
12208 tree spec;
12210 tree ctx;
12219 {
12220 /* If this is the canonical decl, we don't have to
12221 mess with instantiations, and often we can't (for
12222 typename, template type parms and such). Note that
12223 TYPE_NAME is not correct for the above test if
12224 we've copied the type for a typedef. */
12230 }
12232 /* Check to see if we already have the specialization we
12233 need. */
12236 {
12237 /* T is a static data member or namespace-scope entity.
12238 We have to substitute into namespace-scope variables
12239 (not just variable templates) because of cases like:
12241 template <class T> void f() { extern T t; }
12243 where the entity referenced is not known until
12244 instantiation time. */
12248 {
12250 complain,
12252 /* If CTX is unchanged, then T is in fact the
12253 specialization we want. That situation occurs when
12254 referencing a static data member within in its own
12255 class. We can use pointer equality, rather than
12256 same_type_p, because DECL_CONTEXT is always
12257 canonical... */
12259 /* ... unless T is a member template; in which
12260 case our caller can be willing to create a
12261 specialization of that template represented
12262 by T. */
12266 }
12269 {
12274 argvec = (coerce_innermost_template_parms
12282 }
12283 }
12284 else
12285 {
12286 /* A local variable. */
12288 /* Subsequent calls to pushdecl will fill this in. */
12291 }
12292 /* If we already have the specialization we need, there is
12293 nothing more to do. */
12295 {
12298 }
12300 /* Create a new node for the specialization we need. */
12303 {
12306 else
12313 }
12315 {
12316 /* Even if the original location is out of scope, the
12317 newly substituted one is not. */
12324 {
12325 /* It may seem that this case cannot occur, since:
12327 typedef void f();
12328 void g() { f x; }
12330 declares a function, not a variable. However:
12332 typedef void f();
12333 template <typename T> void g() { T t; }
12334 template void g<f>();
12336 is an attempt to declare a variable with function
12337 type. */
12339 /* R is not yet sufficiently initialized, so we
12340 just use its name. */
12343 }
12345 /* Wait until cp_finish_decl to set this again, to handle
12346 circular dependency (template/instantiate6.C). */
12351 {
12356 {
12359 }
12361 }
12365 }
12371 /* Clear out the mangled name and RTL for the instantiation. */
12375 /* The initializer must not be expanded until it is required;
12376 see [temp.inst]. */
12384 {
12385 /* Possibly limit visibility based on template args. */
12388 {
12392 }
12394 }
12397 {
12398 /* A static data member declaration is always marked
12399 external when it is declared in-class, even if an
12400 initializer is present. We mimic the non-template
12401 processing here. */
12409 }
12410 else
12411 {
12416 }
12424 /* Preserve a typedef that names a type. */
12426 {
12430 /* An alias template specialization can be dependent
12431 even if its underlying type is not. */
12433 }
12436 }
12441 }
12442 #undef RETURN
12444 out:
12445 /* Restore the file and line information. */
12449 }
12451 /* Substitute into the ARG_TYPES of a function type.
12452 If END is a TREE_CHAIN, leave it and any following types
12453 un-substituted. */
12455 static tree
12457 tree args,
12458 tree end,
12459 tsubst_flags_t complain,
12460 tree in_decl)
12461 {
12462 tree remaining_arg_types;
12466 tree default_arg;
12477 {
12478 /* For a pack expansion, perform substitution on the
12479 entire expression. Later on, we'll handle the arguments
12480 one-by-one. */
12485 /* So that we'll spin through the parameters, one by one. */
12487 else
12488 {
12489 /* We only partially substituted into the parameter
12490 pack. Our type is TYPE_PACK_EXPANSION. */
12493 }
12494 }
12507 {
12509 {
12513 }
12515 }
12516 /* DR 657. */
12520 /* Do array-to-pointer, function-to-pointer conversion, and ignore
12521 top-level qualifiers as required. */
12524 /* We do not substitute into default arguments here. The standard
12525 mandates that they be instantiated only when needed, which is
12526 done in build_over_call. */
12530 {
12531 /* We've instantiated a template before its default arguments
12532 have been parsed. This can happen for a nested template
12533 class, and is not an error unless we require the default
12534 argument in a call of this function. */
12535 remaining_arg_types =
12538 }
12539 else
12540 remaining_arg_types =
12542 }
12545 }
12547 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
12548 *not* handle the exception-specification for FNTYPE, because the
12549 initial substitution of explicitly provided template parameters
12550 during argument deduction forbids substitution into the
12551 exception-specification:
12553 [temp.deduct]
12555 All references in the function type of the function template to the
12556 corresponding template parameters are replaced by the specified tem-
12557 plate argument values. If a substitution in a template parameter or
12558 in the function type of the function template results in an invalid
12559 type, type deduction fails. [Note: The equivalent substitution in
12560 exception specifications is done only when the function is instanti-
12561 ated, at which point a program is ill-formed if the substitution
12562 results in an invalid type.] */
12564 static tree
12566 tree args,
12567 tsubst_flags_t complain,
12568 tree in_decl)
12569 {
12570 tree return_type;
12572 tree fntype;
12574 /* The TYPE_CONTEXT is not used for function/method types. */
12577 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
12578 failure. */
12582 {
12583 /* Substitute the argument types. */
12595 {
12596 /* DR 1207: 'this' is in scope in the trailing return type. */
12598 }
12600 /* Substitute the return type. */
12604 {
12607 }
12608 }
12609 else
12610 /* Substitute the return type. */
12615 /* DR 486 clarifies that creation of a function type with an
12616 invalid return type is a deduction failure. */
12619 {
12621 {
12624 else
12626 }
12628 }
12629 /* And DR 657. */
12634 {
12635 /* Substitute the argument types. */
12640 }
12642 /* Construct a new type node and return it. */
12644 {
12649 }
12650 else
12651 {
12653 /* Don't pick up extra function qualifiers from the basetype. */
12656 {
12657 /* [temp.deduct]
12659 Type deduction may fail for any of the following
12660 reasons:
12662 -- Attempting to create "pointer to member of T" when T
12663 is not a class type. */
12666 r);
12668 }
12673 }
12680 }
12682 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
12683 ARGS into that specification, and return the substituted
12684 specification. If there is no specification, return NULL_TREE. */
12686 static tree
12688 tree args,
12689 tsubst_flags_t complain,
12690 tree in_decl,
12692 {
12693 tree specs;
12694 tree new_specs;
12699 {
12700 /* A noexcept-specifier. */
12705 {
12706 /* Defer instantiation of noexcept-specifiers to avoid
12707 excessive instantiations (c++/49107). */
12710 {
12711 /* We already partially instantiated this member template,
12712 so combine the new args with the old. */
12717 }
12718 else
12719 {
12722 }
12723 }
12724 else
12725 new_specs = tsubst_copy_and_build
12729 }
12731 {
12734 else
12736 {
12737 tree spec;
12742 {
12743 /* Expand the pack expansion type. */
12746 in_decl);
12752 else
12753 {
12754 /* We're substituting into a member template, so
12755 we got a TYPE_PACK_EXPANSION back. Add that
12756 expansion and move on. */
12760 expanded_specs,
12761 complain);
12764 }
12765 }
12768 {
12771 else
12776 complain);
12777 }
12780 }
12781 }
12783 }
12785 /* Take the tree structure T and replace template parameters used
12786 therein with the argument vector ARGS. IN_DECL is an associated
12787 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
12788 Issue error and warning messages under control of COMPLAIN. Note
12789 that we must be relatively non-tolerant of extensions here, in
12790 order to preserve conformance; if we allow substitutions that
12791 should not be allowed, we may allow argument deductions that should
12792 not succeed, and therefore report ambiguous overload situations
12793 where there are none. In theory, we could allow the substitution,
12794 but indicate that it should have failed, and allow our caller to
12795 make sure that the right thing happens, but we don't try to do this
12796 yet.
12798 This function is used for dealing with types, decls and the like;
12799 for expressions, use tsubst_expr or tsubst_copy. */
12801 tree
12803 {
12826 else
12831 /* Reuse typedefs. We need to do this to handle dependent attributes,
12832 such as attribute aligned. */
12835 {
12839 {
12840 /* DECL represents an alias template and we want to
12841 instantiate it. */
12845 }
12849 {
12853 }
12858 else
12859 /* The typedef is from a non-template context. */
12863 {
12865 r = cp_build_qualified_type_real
12869 }
12870 else
12871 {
12872 /* We don't have an instantiation yet, so drop the typedef. */
12877 }
12878 }
12891 {
12917 {
12923 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
12924 needed. */
12930 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
12931 with TREE_SIDE_EFFECTS that indicates this is not an integral
12932 constant expression. */
12935 {
12938 }
12941 }
12947 {
12953 /* Early in template argument deduction substitution, we don't
12954 want to reduce the level of 'auto', or it will be confused
12955 with a normal template parm in subsequent deduction. */
12967 {
12971 {
12972 /* See through ARGUMENT_PACK_SELECT arguments. */
12974 /* If the selected argument is an expansion E, that most
12975 likely means we were called from
12976 gen_elem_of_pack_expansion_instantiation during the
12977 substituting of pack an argument pack (which Ith
12978 element is a pack expansion, where I is
12979 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
12980 In this case, the Ith element resulting from this
12981 substituting is going to be a pack expansion, which
12982 pattern is the pattern of E. Let's return the
12983 pattern of E, and
12984 gen_elem_of_pack_expansion_instantiation will
12985 build the resulting pack expansion from it. */
12987 {
12988 /* Make sure we aren't throwing away arg info. */
12991 }
12992 }
12993 }
12998 {
13000 /* If ARG is an argument pack, we don't actually want to
13001 perform a substitution here, because substitutions
13002 for argument packs are only done
13003 element-by-element. We can get to this point when
13004 substituting the type of a non-type template
13005 parameter pack, when that type actually contains
13006 template parameter packs from an outer template, e.g.,
13008 template<typename... Types> struct A {
13009 template<Types... Values> struct B { };
13010 }; */
13014 {
13020 return cp_build_qualified_type_real
13022 }
13024 {
13025 /* We are processing a type constructed from a
13026 template template parameter. */
13037 /* Consider this code:
13039 template <template <class> class Template>
13040 struct Internal {
13041 template <class Arg> using Bind = Template<Arg>;
13042 };
13044 template <template <class> class Template, class Arg>
13045 using Instantiate = Template<Arg>; //#0
13047 template <template <class> class Template,
13048 class Argument>
13049 using Bind =
13050 Instantiate<Internal<Template>::template Bind,
13051 Argument>; //#1
13053 When #1 is parsed, the
13054 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13055 parameter `Template' in #0 matches the
13056 UNBOUND_CLASS_TEMPLATE representing the argument
13057 `Internal<Template>::template Bind'; We then want
13058 to assemble the type `Bind<Argument>' that can't
13059 be fully created right now, because
13060 `Internal<Template>' not being complete, the Bind
13061 template cannot be looked up in that context. So
13062 we need to "store" `Bind<Argument>' for later
13063 when the context of Bind becomes complete. Let's
13064 store that in a TYPENAME_TYPE. */
13068 argvec),
13069 typename_type,
13070 complain);
13072 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13073 are resolving nested-types in the signature of a
13074 member function templates. Otherwise ARG is a
13075 TEMPLATE_DECL and is the real template to be
13076 instantiated. */
13084 complain);
13085 return cp_build_qualified_type_real
13087 }
13088 else
13089 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
13091 }
13094 /* This can happen during the attempted tsubst'ing in
13095 unify. This means that we don't yet have any information
13096 about the template parameter in question. */
13099 /* If we get here, we must have been looking at a parm for a
13100 more deeply nested template. Make a new version of this
13101 template parameter, but with a lower level. */
13103 {
13108 {
13110 r = cp_build_qualified_type_real
13114 }
13121 /* Break infinite recursion when substituting the constraints
13123 else
13124 {
13134 /* Propagate constraints on placeholders. */
13141 /* We have reduced the level of the template
13142 template parameter, but not the levels of its
13143 template parameters, so canonical_type_parameter
13144 will not be able to find the canonical template
13145 template parameter for this level. Thus, we
13146 require structural equality checking to compare
13147 TEMPLATE_TEMPLATE_PARMs. */
13151 else
13155 {
13163 }
13164 }
13173 }
13176 }
13179 {
13187 {
13191 }
13194 {
13198 }
13201 {
13205 }
13211 }
13214 /* We should never be tsubsting a binfo. */
13218 /* A vector of template arguments. */
13224 {
13228 /* [temp.deduct]
13230 Type deduction may fail for any of the following
13231 reasons:
13233 -- Attempting to create a pointer to reference type.
13234 -- Attempting to create a reference to a reference type or
13235 a reference to void.
13237 Core issue 106 says that creating a reference to a reference
13238 during instantiation is no longer a cause for failure. We
13239 only enforce this check in strict C++98 mode. */
13243 {
13246 /* We keep track of the last time we issued this error
13247 message to avoid spewing a ton of messages during a
13248 single bad template instantiation. */
13251 {
13256 else
13259 }
13262 }
13266 {
13268 {
13271 type);
13272 else
13274 type);
13275 }
13277 }
13279 {
13283 }
13285 /* In C++0x, during template argument substitution, when there is an
13286 attempt to create a reference to a reference type, reference
13287 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13289 "If a template-argument for a template-parameter T names a type
13290 that is a reference to a type A, an attempt to create the type
13291 'lvalue reference to cv T' creates the type 'lvalue reference to
13292 A,' while an attempt to create the type type rvalue reference to
13293 cv T' creates the type T"
13294 */
13295 r = cp_build_reference_type
13298 else
13303 /* Will this ever be needed for TYPE_..._TO values? */
13307 }
13309 {
13312 {
13313 /* [temp.deduct]
13315 Type deduction may fail for any of the following
13316 reasons:
13318 -- Attempting to create "pointer to member of T" when T
13319 is not a class type. */
13323 }
13325 {
13329 }
13331 {
13335 }
13338 {
13339 /* The type of the implicit object parameter gets its
13340 cv-qualifiers from the FUNCTION_TYPE. */
13341 tree memptr;
13342 tree method_type
13347 complain);
13348 }
13349 else
13352 complain);
13353 }
13356 {
13357 tree fntype;
13358 tree specs;
13363 /* Substitute the exception specification. */
13371 }
13373 {
13378 /* As an optimization, we avoid regenerating the array type if
13379 it will obviously be the same as T. */
13383 /* These checks should match the ones in create_array_type_for_decl.
13385 [temp.deduct]
13387 The deduction may fail for any of the following reasons:
13389 -- Attempting to create an array with an element type that
13390 is void, a function type, or a reference type, or [DR337]
13391 an abstract class type. */
13397 {
13401 }
13409 {
13412 }
13415 }
13418 {
13428 {
13432 }
13434 {
13435 /* Normally, make_typename_type does not require that the CTX
13436 have complete type in order to allow things like:
13438 template <class T> struct S { typename S<T>::X Y; };
13440 But, such constructs have already been resolved by this
13441 point, so here CTX really should have complete type, unless
13442 it's a partial instantiation. */
13445 {
13449 }
13450 }
13457 {
13460 }
13463 {
13465 {
13469 else
13471 }
13473 {
13477 else
13479 }
13480 }
13482 return cp_build_qualified_type_real
13484 }
13487 {
13499 }
13502 {
13503 tree type;
13519 complain);
13520 }
13523 {
13524 tree type;
13542 else
13543 {
13547 /* In a template ~id could be either a complement expression
13548 or an unqualified-id naming a destructor; if instantiating
13549 it produces an expression, it's not an id-expression or
13550 member access. */
13553 }
13558 }
13561 {
13565 }
13569 {
13571 tree packed_out =
13573 args,
13574 complain,
13575 in_decl);
13578 /* For template nontype argument packs, also substitute into
13579 the type. */
13584 }
13600 /* We should use one of the expression tsubsts for these codes. */
13606 }
13607 }
13609 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
13610 type of the expression on the left-hand side of the "." or "->"
13611 operator. */
13613 static tree
13616 {
13617 tree name;
13618 tree qualifying_scope;
13619 tree fns;
13620 tree optype;
13625 /* A baselink indicates a function from a base class. Both the
13626 BASELINK_ACCESS_BINFO and the base class referenced may
13627 indicate bases of the template class, rather than the
13628 instantiated class. In addition, lookups that were not
13629 ambiguous before may be ambiguous now. Therefore, we perform
13630 the lookup again. */
13637 {
13644 }
13650 {
13652 {
13656 }
13658 }
13660 /* If lookup found a single function, mark it as used at this
13661 point. (If it lookup found multiple functions the one selected
13662 later by overload resolution will be marked as used at that
13663 point.) */
13670 /* Add back the template arguments, if present. */
13674 unknown_type_node,
13676 template_args);
13677 /* Update the conversion operator type. */
13685 qualifying_scope,
13686 object_type);
13688 }
13690 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
13691 true if the qualified-id will be a postfix-expression in-and-of
13692 itself; false if more of the postfix-expression follows the
13693 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
13694 of "&". */
13696 static tree
13700 {
13701 tree expr;
13702 tree scope;
13703 tree name;
13705 tree template_args;
13710 /* Figure out what name to look up. */
13713 {
13721 }
13722 else
13723 {
13726 }
13728 /* Substitute into the qualifying scope. When there are no ARGS, we
13729 are just trying to simplify a non-dependent expression. In that
13730 case the qualifying scope may be dependent, and, in any case,
13731 substituting will not help. */
13734 {
13737 }
13738 else
13742 {
13747 }
13750 {
13752 {
13753 /* A BIT_NOT_EXPR is used to represent a destructor. */
13755 {
13759 }
13760 else
13763 }
13764 else
13768 {
13770 {
13774 }
13776 }
13777 }
13780 {
13782 scope);
13783 /* Remember that there was a reference to this entity. */
13786 }
13789 {
13795 }
13798 {
13801 complain);
13802 else
13804 }
13810 {
13811 expr = (adjust_result_of_qualified_name_lookup
13813 expr = (finish_qualified_id_expr
13817 }
13819 /* Expressions do not generally have reference type. */
13821 /* However, if we're about to form a pointer-to-member, we just
13822 want the referenced member referenced. */
13827 }
13829 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
13830 initializer, DECL is the substituted VAR_DECL. Other arguments are as
13831 for tsubst. */
13833 static tree
13836 {
13843 {
13844 /* If we had an initializer but it
13845 instantiated to nothing,
13846 value-initialize the object. This will
13847 only occur when the initializer was a
13848 pack expansion where the parameter packs
13849 used in that expansion were of length
13850 zero. */
13852 complain);
13855 }
13858 }
13860 /* Like tsubst, but deals with expressions. This function just replaces
13861 template parms; to finish processing the resultant expression, use
13862 tsubst_copy_and_build or tsubst_expr. */
13864 static tree
13866 {
13868 tree r;
13876 {
13881 {
13882 /* We get here for a use of 'this' in an NSDMI as part of a
13883 constructor call or as part of an aggregate initialization. */
13885 && ((current_function_decl
13887 || (current_class_ref
13891 /* This can happen for a parameter name used later in a function
13892 declaration (such as in a late-specified return type). Just
13893 make a dummy decl, since it's only used for its type. */
13896 /* Give it the template pattern as its context; its true context
13897 hasn't been instantiated yet and this is good enough for
13898 mangling. */
13900 }
13909 {
13910 tree enum_type;
13911 tree v;
13915 /* There is no need to substitute into namespace-scope
13916 enumerators. */
13919 /* If ARGS is NULL, then T is known to be non-dependent. */
13923 /* Unfortunately, we cannot just call lookup_name here.
13924 Consider:
13926 template <int I> int f() {
13927 enum E { a = I };
13928 struct S { void g() { E e = a; } };
13929 };
13931 When we instantiate f<7>::S::g(), say, lookup_name is not
13932 clever enough to find f<7>::a. */
13933 enum_type
13943 /* We didn't find the name. That should never happen; if
13944 name-lookup found it during preliminary parsing, we
13945 should find it again here during instantiation. */
13947 }
13952 {
13953 /* Check for a local specialization set up by
13954 tsubst_pack_expansion. */
13956 {
13960 }
13962 /* When retrieving a capture pack from a generic lambda, remove the
13963 lambda call op's own template argument list from ARGS. Only the
13964 template arguments active for the closure type should be used to
13965 retrieve the pack specialization. */
13971 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
13972 tsubst_decl put in the hash table. */
13974 }
13977 {
13978 tree ctx;
13983 {
13986 {
13990 }
13992 }
13993 }
14002 {
14005 {
14006 /* First try name lookup to find the instantiation. */
14009 {
14010 /* Make sure that the one we found is the one we want. */
14016 }
14020 else
14021 {
14022 /* This can happen for a variable used in a
14023 late-specified return type of a local lambda, or for a
14024 local static or constant. Building a new VAR_DECL
14025 should be OK in all those cases. */
14028 {
14029 /* We can't call cp_finish_decl, so handle the
14030 initializer by hand. */
14041 }
14046 {
14049 at_eof);
14050 else
14052 }
14053 }
14054 /* Remember this for subsequent uses. */
14057 }
14058 }
14059 else
14069 /* An OVERLOAD will always be a non-dependent overload set; an
14070 overload set from function scope will just be represented with an
14071 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14087 {
14088 /* Template template argument like the following example need
14089 special treatment:
14091 template <template <class> class TT> struct C {};
14092 template <class T> struct D {
14093 template <class U> struct E {};
14094 C<E> c; // #1
14095 };
14096 D<int> d; // #2
14098 We are processing the template argument `E' in #1 for
14099 the template instantiation #2. Originally, `E' is a
14100 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14101 have to substitute this with one having context `D<int>'. */
14105 }
14106 else
14107 /* Ordinary template template argument. */
14118 {
14122 }
14127 {
14136 /* We only want to compute the number of arguments. */
14139 else
14146 {
14148 /* Set TREE_USED for the benefit of -Wunused. */
14151 }
14159 {
14164 else
14170 else
14173 }
14174 else
14176 }
14178 {
14186 }
14187 /* Fall through */
14203 {
14207 }
14210 {
14211 tree object;
14212 tree name;
14217 {
14221 }
14224 {
14234 }
14239 in_decl);
14240 else
14243 }
14281 {
14285 }
14288 {
14293 }
14296 {
14300 }
14303 {
14311 }
14317 {
14324 }
14327 {
14334 }
14337 {
14344 }
14347 {
14348 /* Substituted template arguments */
14357 }
14360 {
14380 }
14405 /* Fall through. */
14408 {
14411 }
14412 else
14416 /* This is handled by tsubst_copy_and_build. */
14420 {
14424 }
14427 /* We shouldn't have built any of these during initial template
14428 generation. Instead, they should be built during instantiation
14429 in response to the saved STMT_IS_FULL_EXPR_P setting. */
14433 {
14443 }
14461 {
14462 /* Instantiate any typedefs in the type. */
14467 }
14470 /* These can sometimes show up in a partial instantiation, but never
14471 involve template parms. */
14485 /* We shouldn't get here, but keep going if !flag_checking. */
14489 }
14490 }
14492 /* Helper function for tsubst_omp_clauses, used for instantiation of
14493 OMP_CLAUSE_DECL of clauses. */
14495 static tree
14497 tree in_decl)
14498 {
14502 /* Handle an OpenMP array section represented as a TREE_LIST (or
14503 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
14504 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
14505 TREE_LIST. We can handle it exactly the same as an array section
14506 (purpose, value, and a chain), even though the nomenclature
14507 (low_bound, length, etc) is different. */
14509 {
14510 tree low_bound
14516 in_decl);
14525 }
14528 /* Undo convert_from_reference tsubst_expr could have called. */
14534 }
14536 /* Like tsubst_copy, but specifically for OpenMP clauses. */
14538 static tree
14541 {
14546 {
14552 {
14555 {
14561 }
14562 /* FALLTHRU */
14577 in_decl);
14608 {
14611 {
14618 }
14619 else
14621 }
14624 in_decl);
14630 in_decl);
14638 in_decl);
14640 {
14643 }
14648 else
14651 in_decl,
14674 {
14678 loc;
14680 {
14683 }
14684 }
14688 }
14691 {
14701 /* tsubst_expr on SCOPE_REF results in returning
14702 finish_non_static_data_member result. Undo that here. */
14706 {
14711 {
14715 CASE_CONVERT:
14724 /* FALLTHRU */
14728 }
14729 }
14735 {
14738 {
14742 }
14743 }
14747 }
14748 }
14752 {
14757 {
14760 }
14761 }
14763 }
14765 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
14767 static tree
14769 tree in_decl)
14770 {
14771 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
14791 {
14794 else
14795 {
14799 }
14800 }
14805 #undef RECUR
14806 }
14808 /* Used to temporarily communicate the list of #pragma omp parallel
14809 clauses to #pragma omp for instantiation if they are combined
14810 together. */
14814 /* Substitute one OMP_FOR iterator. */
14816 static void
14821 {
14822 #define RECUR(NODE) \
14823 tsubst_expr ((NODE), args, complain, in_decl, \
14824 integral_constant_expression_p)
14831 {
14834 }
14840 {
14841 /* We need to jump through some hoops to handle declarations in the
14842 for-init-statement, since we might need to handle auto deduction,
14843 but we need to keep control of initialization. */
14847 }
14848 else
14849 {
14851 {
14854 {
14858 {
14862 CASE_CONVERT:
14870 {
14873 }
14874 /* FALLTHRU */
14878 }
14879 }
14880 }
14881 else
14883 }
14894 {
14896 {
14897 /* Declare the variable, but don't let that initialize it. */
14902 }
14907 {
14912 }
14913 else
14920 }
14923 {
14924 /* Declare and initialize the variable. */
14927 }
14929 {
14933 {
14935 {
14941 {
14944 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
14949 }
14952 {
14954 decl);
14956 }
14959 {
14961 decl);
14963 }
14964 else
14966 }
14969 }
14971 {
14976 {
14979 }
14980 }
14981 }
14984 {
14988 }
14989 else
14993 {
15004 {
15012 }
15013 else
15019 {
15025 }
15029 {
15037 }
15038 else
15044 }
15050 #undef RECUR
15051 }
15053 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15054 of OMP_TARGET's body. */
15056 static tree
15058 {
15061 {
15070 }
15072 }
15074 /* Like tsubst_copy for expressions, etc. but also does semantic
15075 processing. */
15077 tree
15080 {
15081 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15082 #define RECUR(NODE) \
15083 tsubst_expr ((NODE), args, complain, in_decl, \
15084 integral_constant_expression_p)
15087 tree r;
15088 location_t loc;
15100 {
15102 {
15103 tree_stmt_iterator i;
15107 }
15122 else
15131 {
15133 tree init;
15139 {
15149 else
15151 }
15153 {
15154 /* Don't build up decls for a variadic capture proxy, we'll
15155 instantiate the elements directly as needed. */
15157 }
15158 else
15159 {
15163 {
15164 /* By marking the declaration as instantiated, we avoid
15165 trying to instantiate it. Since instantiate_decl can't
15166 handle local variables, and since we've already done
15167 all that needs to be done, that's the right thing to
15168 do. */
15173 /* Anonymous aggregates are a special case. */
15176 {
15179 {
15183 }
15185 }
15191 {
15196 }
15197 else
15198 {
15203 {
15204 /* For __PRETTY_FUNCTION__ we have to adjust the
15205 initializer. */
15209 }
15210 else
15214 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15217 }
15218 }
15219 }
15222 }
15237 {
15247 }
15274 {
15278 }
15286 else
15294 else
15315 {
15319 }
15323 {
15325 tree label;
15330 }
15336 /* Computed goto's must be tsubst'd into. On the other hand,
15337 non-computed gotos must not be; the identifier in question
15338 will have no binding. */
15340 else
15346 {
15362 }
15367 {
15372 }
15373 else
15374 {
15379 else
15386 else
15392 else
15394 }
15398 {
15402 {
15404 /* Prevent instantiate_decl from trying to instantiate
15405 this variable. We've already done all that needs to be
15406 done. */
15409 }
15414 }
15420 {
15421 /* Local classes are not independent templates; they are
15422 instantiated along with their containing function. And this
15423 way we don't have to deal with pushing out of one local class
15424 to instantiate a member of another local class. */
15425 tree fn;
15426 /* Closures are handled by the LAMBDA_EXPR. */
15432 }
15436 {
15437 tree condition;
15440 condition =
15442 args,
15451 }
15457 in_decl);
15494 {
15509 in_decl);
15511 {
15518 }
15530 integral_constant_expression_p);
15541 else
15542 {
15550 }
15554 }
15559 /* FALLTHRU */
15566 in_decl);
15583 in_decl);
15594 {
15597 {
15598 /* For combined target teams, ensure the num_teams and
15599 thread_limit clause expressions are evaluated on the host,
15600 before entering the target construct. */
15601 tree c;
15607 {
15616 OMP_CLAUSE_FIRSTPRIVATE);
15620 }
15621 }
15622 }
15682 {
15687 {
15690 }
15696 }
15697 else
15698 {
15705 {
15708 }
15711 {
15716 {
15719 }
15725 }
15726 else
15727 {
15731 }
15734 }
15738 {
15744 {
15748 {
15753 }
15757 }
15758 else
15759 {
15764 }
15765 }
15769 {
15773 }
15793 /* If the first operand was a statement, we're done with it. */
15797 complain));
15809 integral_constant_expression_p));
15810 }
15813 out:
15816 #undef RECUR
15817 #undef RETURN
15818 }
15820 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
15821 function. For description of the body see comment above
15822 cp_parser_omp_declare_reduction_exprs. */
15824 static void
15826 {
15832 tree_stmt_iterator tsi;
15843 {
15862 }
15864 {
15884 }
15885 }
15887 /* T is a postfix-expression that is not being used in a function
15888 call. Return the substituted version of T. */
15890 static tree
15892 tsubst_flags_t complain,
15893 tree in_decl)
15894 {
15898 else
15904 }
15906 /* Like tsubst but deals with expressions and performs semantic
15907 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
15909 tree
15911 tree args,
15912 tsubst_flags_t complain,
15913 tree in_decl,
15916 {
15917 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
15918 #define RECUR(NODE) \
15919 tsubst_copy_and_build (NODE, args, complain, in_decl, \
15921 integral_constant_expression_p)
15924 location_t loc;
15933 /* N3276 decltype magic only applies to calls at the top level or on the
15934 right side of a comma. */
15939 {
15942 /* Fall through. */
15944 {
15945 tree decl;
15946 cp_id_kind idk;
15951 {
15954 }
15956 /* Look up the name. */
15959 /* By convention, expressions use ERROR_MARK_NODE to indicate
15960 failure, not NULL_TREE. */
15966 integral_constant_expression_p,
15974 input_location);
15978 {
15982 }
15984 }
15987 {
15988 tree object;
16001 {
16004 }
16005 else
16012 else
16014 }
16017 {
16021 {
16022 /* A type conversion to reference type will be enclosed in
16023 such an indirect ref, but the substitution of the cast
16024 will have also added such an indirect ref. */
16027 }
16028 else
16036 }
16039 {
16043 }
16046 {
16053 flags));
16054 }
16057 {
16061 }
16068 {
16069 tree type;
16075 {
16080 }
16086 {
16104 }
16107 }
16141 else
16143 in_decl);
16178 {
16185 tree r = build_x_binary_op
16187 op0,
16189 ? ERROR_MARK
16191 op1,
16193 ? ERROR_MARK
16201 }
16204 {
16208 }
16221 {
16230 }
16235 /* Fall through */
16238 {
16239 tree r;
16245 {
16246 /* When there are no ARGS, we are trying to evaluate a
16247 non-dependent expression from the parser. Trying to do
16248 the substitutions may not work. */
16251 }
16252 else
16253 {
16258 else
16261 /*integral_constant_expression_p=*/
16265 }
16269 else
16273 {
16275 {
16277 {
16281 }
16282 else
16286 }
16288 }
16290 }
16293 {
16303 }
16319 {
16323 tree r = build_x_modify_expr
16326 /* TREE_NO_WARNING must be set if either the expression was
16327 parenthesized or it uses an operator such as >>= rather
16328 than plain assignment. In the former case, it was already
16329 set and must be copied. In the latter case,
16330 build_x_modify_expr sets it and it must not be reset
16331 here. */
16336 }
16341 /* Remember that there was a reference to this entity. */
16348 {
16353 tree ret;
16357 else
16358 {
16362 }
16364 /* If there was an initializer in the original tree, but it
16365 instantiated to an empty list, then we should pass a
16366 non-NULL empty vector to tell build_new that it was an
16367 empty initializer() rather than no initializer. This can
16368 only happen when the initializer is a pack expansion whose
16369 parameter packs are of length zero. */
16372 else
16373 {
16377 else
16378 {
16381 }
16382 }
16388 complain);
16396 }
16399 {
16405 complain));
16406 }
16409 {
16413 integral_constant_expression_p);
16415 op0,
16418 }
16421 {
16422 tree function;
16427 tree ret;
16430 /* When we parsed the expression, we determined whether or
16431 not Koenig lookup should be performed. */
16434 {
16439 }
16441 {
16442 /* Do nothing; calling tsubst_copy_and_build on an identifier
16443 would incorrectly perform unqualified lookup again.
16445 Note that we can also have an IDENTIFIER_NODE if the earlier
16446 unqualified lookup found a member function; in that case
16447 koenig_p will be false and we do want to do the lookup
16448 again to find the instantiated member function.
16450 FIXME but doing that causes c++/15272, so we need to stop
16451 using IDENTIFIER_NODE in that situation. */
16453 }
16454 else
16455 {
16457 {
16463 }
16464 else
16469 /* Avoid error about taking the address of a constructor. */
16473 in_decl,
16475 integral_constant_expression_p);
16479 }
16484 {
16489 else
16490 {
16491 /* Expand the pack expansion and push each entry onto
16492 CALL_ARGS. */
16495 {
16500 {
16505 }
16506 }
16507 else
16508 {
16509 /* A partial substitution. Add one entry. */
16511 }
16512 }
16513 }
16515 /* We do not perform argument-dependent lookup if normal
16516 lookup finds a non-function, in accordance with the
16517 expected resolution of DR 218. */
16520 /* If lookup found a member function, the Koenig lookup is
16521 not appropriate, even if an unqualified-name was used
16522 to denote the function. */
16525 /* Only do this when substitution turns a dependent call
16526 into a non-dependent call. */
16533 {
16535 {
16536 /* For backwards compatibility and good diagnostics, try
16537 the unqualified lookup again if we aren't in SFINAE
16538 context. */
16539 tree unq = (tsubst_copy_and_build
16541 integral_constant_expression_p));
16546 {
16555 "%qD was not declared in this scope, "
16556 "and no declarations were found by "
16557 "argument-dependent lookup at the point "
16559 {
16563 {
16565 input_location);
16567 "declarations in dependent base %qT are "
16573 else
16577 }
16578 else
16580 "%qD declared here, later in the "
16582 }
16584 }
16585 }
16587 {
16592 }
16593 }
16595 /* Remember that there was a reference to this entity. */
16600 /* Put back tf_decltype for the actual call. */
16605 complain);
16607 {
16622 complain);
16623 else
16624 ret = (build_new_method_call
16629 complain));
16630 }
16631 else
16634 koenig_p,
16635 complain);
16640 }
16643 {
16649 {
16651 {
16656 }
16657 else
16658 {
16663 }
16665 }
16666 else
16667 {
16670 }
16674 }
16677 {
16682 input_location));
16683 }
16686 {
16694 {
16695 /* We have pack expansions, so expand those and
16696 create a new list out of it. */
16699 tree chain;
16702 /* Expand the argument expressions. */
16710 /* Build the rest of the list. */
16715 /* Determine the number of arguments. */
16717 {
16720 }
16723 else
16724 {
16725 /* Since we only performed a partial substitution into
16726 the argument pack, we only RETURN (a single list
16727 node. */
16734 }
16736 /* Convert the argument vectors into a TREE_LIST */
16739 {
16740 /* Grab the Ith values. */
16741 i--;
16744 value
16748 /* Build the list (backwards). */
16750 }
16753 }
16769 }
16772 {
16773 tree object;
16774 tree object_type;
16775 tree member;
16776 tree r;
16780 /* Remember that there was a reference to this entity. */
16791 else
16799 {
16801 {
16806 {
16809 }
16811 {
16816 }
16817 }
16818 }
16821 {
16822 /* Lookup the template functions now that we know what the
16823 scope is. */
16831 {
16834 args);
16835 member = (adjust_result_of_qualified_name_lookup
16837 object_type));
16838 }
16839 else
16840 {
16842 input_location);
16844 }
16845 }
16849 {
16851 {
16855 else
16858 }
16860 }
16862 {
16867 }
16871 complain);
16875 }
16882 {
16890 tree r;
16895 /* digest_init will do the wrong thing if we let it. */
16899 /* We do not want to process the index of aggregate
16900 initializers as they are identifier nodes which will be
16901 looked up by digest_init. */
16907 {
16909 /* An identifier index is looked up in the type
16910 being initialized, not the current scope. */
16915 {
16916 /* Substitute into the pack expansion. */
16918 in_decl);
16922 ;
16924 /* Just move the argument into place. */
16926 else
16927 {
16928 /* Update the length of the final CONSTRUCTOR
16929 arguments vector, and note that we will need to
16930 copy.*/
16933 }
16934 }
16935 else
16937 }
16940 {
16945 {
16947 {
16952 }
16953 else
16955 }
16956 }
16966 }
16969 {
16972 {
16975 }
16976 else
16977 {
16980 }
16981 }
16987 {
16988 /* We don't build decls for an instantiation of a
16989 variadic capture proxy, we instantiate the elements
16990 when needed. */
16993 }
16994 /* Fall through */
16997 {
16999 /* ??? We're doing a subset of finish_id_expression here. */
17001 && !processing_template_decl
17002 && !cp_unevaluated_operand
17005 {
17007 /* Replace an evaluated use of the thread_local variable with
17008 a call to its wrapper. */
17010 }
17012 {
17016 }
17019 /* If the original type was a reference, we'll be wrapped in
17020 the appropriate INDIRECT_REF. */
17023 }
17026 {
17030 }
17037 {
17048 }
17051 {
17057 integral_constant_expression_p);
17061 /* If the resulting list of expression statement is empty,
17062 fold it further into void_node. */
17067 }
17070 {
17088 /* For a function or variable scope, we want to use tsubst so that we
17089 don't complain about referring to an auto before deduction. */
17092 {
17093 /* Look up the parameter we want directly, as tsubst_copy
17094 doesn't do what we need. */
17100 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17103 }
17105 /* For a field, use tsubst_copy so that we look up the existing field
17106 rather than build a new one. */
17108 else
17115 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17117 /* Now that we know visibility, instantiate the type so we have a
17118 declaration of the op() for later calls to lambda_function. */
17129 }
17132 /* We can get here for a constant initializer of non-dependent type.
17133 FIXME stop folding in cp_parser_initializer_clause. */
17134 {
17136 complain);
17138 }
17142 integral_constant_expression_p));
17148 {
17153 complain));
17154 }
17160 /* Handle Objective-C++ constructs, if appropriate. */
17161 {
17162 tree subst
17167 }
17169 }
17171 #undef RECUR
17172 #undef RETURN
17173 out:
17176 }
17178 /* Verify that the instantiated ARGS are valid. For type arguments,
17179 make sure that the type's linkage is ok. For non-type arguments,
17180 make sure they are constants if they are integral or enumerations.
17181 Emit an error under control of COMPLAIN, and return TRUE on error. */
17183 static bool
17185 {
17189 {
17199 }
17201 {
17202 /* [basic.link]: A name with no linkage (notably, the name
17203 of a class or enumeration declared in a local scope)
17204 shall not be used to declare an entity with linkage.
17205 This implies that names with no linkage cannot be used as
17206 template arguments
17208 DR 757 relaxes this restriction for C++0x. */
17213 {
17214 /* DR 488 makes use of a type with no linkage cause
17215 type deduction to fail. */
17217 {
17220 else
17223 }
17225 }
17226 /* In order to avoid all sorts of complications, we do not
17227 allow variably-modified types as template arguments. */
17229 {
17233 }
17234 }
17235 /* Class template and alias template arguments should be OK. */
17237 ;
17238 /* A non-type argument of integral or enumerated type must be a
17239 constant. */
17244 {
17248 }
17250 }
17252 static bool
17254 {
17259 {
17262 }
17266 }
17268 /* We're out of SFINAE context now, so generate diagnostics for the access
17269 errors we saw earlier when instantiating D from TMPL and ARGS. */
17271 static void
17273 {
17285 }
17287 /* Instantiate the indicated variable, function, or alias template TMPL with
17288 the template arguments in TARG_PTR. */
17290 static tree
17292 {
17294 tree fndecl;
17295 tree gen_tmpl;
17296 tree spec;
17304 /* If this function is a clone, handle it specially. */
17306 {
17307 tree spec;
17308 tree clone;
17310 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
17311 DECL_CLONED_FUNCTION. */
17317 /* Look for the clone. */
17321 /* We should always have found the clone by now. */
17324 }
17329 /* Check to see if we already have this specialization. */
17332 /* The TMPL is a partial instantiation. To get a full set of
17333 arguments we must add the arguments used to perform the
17334 partial instantiation. */
17336 targ_ptr);
17338 /* It would be nice to avoid hashing here and then again in tsubst_decl,
17339 but it doesn't seem to be on the hot path. */
17348 {
17350 {
17354 }
17356 }
17359 complain))
17362 /* We are building a FUNCTION_DECL, during which the access of its
17363 parameters and return types have to be checked. However this
17364 FUNCTION_DECL which is the desired context for access checking
17365 is not built yet. We solve this chicken-and-egg problem by
17366 deferring all checks until we have the FUNCTION_DECL. */
17369 /* Instantiation of the function happens in the context of the function
17370 template, not the context of the overload resolution we're doing. */
17372 /* If there are dependent arguments, e.g. because we're doing partial
17373 ordering, make sure processing_template_decl stays set. */
17377 {
17381 }
17386 {
17387 /* We need to determine if we're using a partial or explicit
17388 specialization now, because the type of the variable could be
17389 different. */
17395 {
17399 }
17400 }
17402 /* Substitute template parameters to obtain the specialization. */
17409 {
17412 }
17414 /* The DECL_TI_TEMPLATE should always be the immediate parent
17415 template, not the most general template. */
17419 /* Now we know the specialization, compute access previously
17420 deferred. */
17427 /* If we've just instantiated the main entry point for a function,
17428 instantiate all the alternate entry points as well. We do this
17429 by cloning the instantiation of the main entry point, not by
17430 instantiating the template clones. */
17435 {
17437 {
17438 /* Remember to reinstantiate when we're out of SFINAE so the user
17439 can see the errors. */
17441 }
17443 }
17445 }
17447 /* Wrapper for instantiate_template_1. */
17449 tree
17451 {
17452 tree ret;
17457 }
17459 /* Instantiate the alias template TMPL with ARGS. Also push a template
17460 instantiation level, which instantiate_template doesn't do because
17461 functions and variables have sufficient context established by the
17462 callers. */
17464 static tree
17466 {
17473 {
17476 }
17478 args =
17486 /* We can't free this if a pending_template entry or last_error_tinst_level
17487 is pointing at it. */
17493 }
17495 /* PARM is a template parameter pack for FN. Returns true iff
17496 PARM is used in a deducible way in the argument list of FN. */
17498 static bool
17500 {
17503 {
17505 tree packs;
17511 {
17512 /* The template parameter pack is used in a function parameter
17513 pack. If this is the end of the parameter list, the
17514 template parameter pack is deducible. */
17517 else
17518 /* Otherwise, not. Well, it could be deduced from
17519 a non-pack parameter, but doing so would end up with
17520 a deduction mismatch, so don't bother. */
17522 }
17523 }
17524 /* The template parameter pack isn't used in any function parameter
17525 packs, but it might be used deeper, e.g. tuple<Args...>. */
17527 }
17529 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
17530 NARGS elements of the arguments that are being used when calling
17531 it. TARGS is a vector into which the deduced template arguments
17532 are placed.
17534 Returns either a FUNCTION_DECL for the matching specialization of FN or
17535 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
17536 true, diagnostics will be printed to explain why it failed.
17538 If FN is a conversion operator, or we are trying to produce a specific
17539 specialization, RETURN_TYPE is the return type desired.
17541 The EXPLICIT_TARGS are explicit template arguments provided via a
17542 template-id.
17544 The parameter STRICT is one of:
17546 DEDUCE_CALL:
17547 We are deducing arguments for a function call, as in
17548 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
17549 deducing arguments for a call to the result of a conversion
17550 function template, as in [over.call.object].
17552 DEDUCE_CONV:
17553 We are deducing arguments for a conversion function, as in
17554 [temp.deduct.conv].
17556 DEDUCE_EXACT:
17557 We are deducing arguments when doing an explicit instantiation
17558 as in [temp.explicit], when determining an explicit specialization
17559 as in [temp.expl.spec], or when taking the address of a function
17560 template, as in [temp.deduct.funcaddr]. */
17562 tree
17564 tree explicit_targs,
17565 tree targs,
17568 tree return_type,
17569 unification_kind_t strict,
17573 {
17574 tree parms;
17575 tree fntype;
17583 tree tinst;
17589 /* In C++0x, it's possible to have a function template whose type depends
17590 on itself recursively. This is most obvious with decltype, but can also
17591 occur with enumeration scope (c++/48969). So we need to catch infinite
17592 recursion and reject the substitution at deduction time; this function
17593 will return error_mark_node for any repeated substitution.
17595 This also catches excessive recursion such as when f<N> depends on
17596 f<N-1> across all integers, and returns error_mark_node for all the
17597 substitutions back up to the initial one.
17599 This is, of course, not reentrant. */
17609 {
17610 /* [temp.deduct]
17612 The specified template arguments must match the template
17613 parameters in kind (i.e., type, nontype, template), and there
17614 must not be more arguments than there are parameters;
17615 otherwise type deduction fails.
17617 Nontype arguments must match the types of the corresponding
17618 nontype template parameters, or must be convertible to the
17619 types of the corresponding nontype parameters as specified in
17620 _temp.arg.nontype_, otherwise type deduction fails.
17622 All references in the function type of the function template
17623 to the corresponding template parameters are replaced by the
17624 specified template argument values. If a substitution in a
17625 template parameter or in the function type of the function
17626 template results in an invalid type, type deduction fails. */
17631 /* Adjust any explicit template arguments before entering the
17632 substitution context. */
17633 explicit_targs
17635 complain,
17641 /* Substitute the explicit args into the function type. This is
17642 necessary so that, for instance, explicitly declared function
17643 arguments can match null pointed constants. If we were given
17644 an incomplete set of explicit args, we must not do semantic
17645 processing during substitution as we could create partial
17646 instantiations. */
17648 {
17653 /* Dig out the actual parm. */
17656 {
17659 }
17661 {
17664 }
17667 /* No explicit argument for this template parameter. */
17671 {
17672 /* Mark the argument pack as "incomplete". We could
17673 still deduce more arguments during unification.
17674 We remove this mark in type_unification_real. */
17676 {
17680 }
17682 /* We have some incomplete argument packs. */
17684 }
17685 }
17689 {
17692 }
17695 /* Ignore any access checks; we'll see them again in
17696 instantiate_template and they might have the wrong
17697 access path at this point. */
17709 /* Place the explicitly specified arguments in TARGS. */
17712 }
17714 /* Never do unification on the 'this' parameter. */
17718 {
17719 /* We're deducing for a call to the result of a template conversion
17720 function. The parms we really want are in return_type. */
17724 }
17726 {
17735 }
17737 /* We allow incomplete unification without an error message here
17738 because the standard doesn't seem to explicitly prohibit it. Our
17739 callers must be ready to deal with unification failures in any
17740 event. */
17743 /* If we aren't explaining yet, push tinst context so we can see where
17744 any errors (e.g. from class instantiations triggered by instantiation
17745 of default template arguments) come from. If we are explaining, this
17746 context is redundant. */
17748 {
17751 }
17753 /* type_unification_real will pass back any access checks from default
17754 template argument substitution. */
17766 /* Now that we have bindings for all of the template arguments,
17767 ensure that the arguments deduced for the template template
17768 parameters have compatible template parameter lists. We cannot
17769 check this property before we have deduced all template
17770 arguments, because the template parameter types of a template
17771 template parameter might depend on prior template parameters
17772 deduced after the template template parameter. The following
17773 ill-formed example illustrates this issue:
17775 template<typename T, template<T> class C> void f(C<5>, T);
17777 template<int N> struct X {};
17779 void g() {
17780 f(X<5>(), 5l); // error: template argument deduction fails
17781 }
17783 The template parameter list of 'C' depends on the template type
17784 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
17785 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
17786 time that we deduce 'C'. */
17789 {
17792 }
17794 /* All is well so far. Now, check:
17796 [temp.deduct]
17798 When all template arguments have been deduced, all uses of
17799 template parameters in nondeduced contexts are replaced with
17800 the corresponding deduced argument values. If the
17801 substitution results in an invalid type, as described above,
17802 type deduction fails. */
17805 {
17808 }
17810 /* Also collect access checks from the instantiation. */
17823 /* Now perform any access checks encountered during substitution. */
17830 /* If we're looking for an exact match, check that what we got
17831 is indeed an exact match. It might not be if some template
17832 parameters are used in non-deduced contexts. But don't check
17833 for an exact match if we have dependent template arguments;
17834 in that case we're doing partial ordering, and we already know
17835 that we have two candidates that will provide the actual type. */
17837 {
17841 tree sarg
17847 {
17851 }
17852 }
17856 fail:
17859 {
17861 /* Reset once we're all the way out. */
17863 }
17865 /* We can't free this if a pending_template entry or last_error_tinst_level
17866 is pointing at it. */
17872 }
17874 /* Adjust types before performing type deduction, as described in
17875 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
17876 sections are symmetric. PARM is the type of a function parameter
17877 or the return type of the conversion function. ARG is the type of
17878 the argument passed to the call, or the type of the value
17879 initialized with the result of the conversion function.
17880 ARG_EXPR is the original argument expression, which may be null. */
17882 static int
17886 tree arg_expr)
17887 {
17891 {
17896 /* Swap PARM and ARG throughout the remainder of this
17897 function; the handling is precisely symmetric since PARM
17898 will initialize ARG rather than vice versa. */
17903 /* Core issue #873: Do the DR606 thing (see below) for these cases,
17904 too, but here handle it by stripping the reference from PARM
17905 rather than by adding it to ARG. */
17913 /* Nothing else to do in this case. */
17918 }
17921 {
17922 /* [temp.deduct.call]
17924 If P is not a reference type:
17926 --If A is an array type, the pointer type produced by the
17927 array-to-pointer standard conversion (_conv.array_) is
17928 used in place of A for type deduction; otherwise,
17930 --If A is a function type, the pointer type produced by
17931 the function-to-pointer standard conversion
17932 (_conv.func_) is used in place of A for type deduction;
17933 otherwise,
17935 --If A is a cv-qualified type, the top level
17936 cv-qualifiers of A's type are ignored for type
17937 deduction. */
17942 else
17944 }
17946 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
17947 of the form T&&, where T is a template parameter, and the argument
17948 is an lvalue, T is deduced as A& */
17954 /* try_one_overload doesn't provide an arg_expr, but
17955 functions are always lvalues. */
17959 /* [temp.deduct.call]
17961 If P is a cv-qualified type, the top level cv-qualifiers
17962 of P's type are ignored for type deduction. If P is a
17963 reference type, the type referred to by P is used for
17964 type deduction. */
17967 {
17970 }
17972 /* DR 322. For conversion deduction, remove a reference type on parm
17973 too (which has been swapped into ARG). */
17978 }
17980 /* Subroutine of unify_one_argument. PARM is a function parameter of a
17981 template which does contain any deducible template parameters; check if
17982 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
17983 unify_one_argument. */
17985 static int
17988 {
17989 tree type;
17993 else
18000 {
18004 }
18006 {
18011 }
18015 else
18017 }
18021 /* Returns true iff the expression EXPR is one from which a template
18022 argument can be deduced. In other words, if it's an undecorated
18023 use of a template non-type parameter. */
18025 static bool
18027 {
18029 }
18031 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18032 deducible way; that is, if it has a max value of <PARM> - 1. */
18034 static bool
18036 {
18045 }
18047 /* Returns true iff the template arguments ARGS use a template parameter
18048 in a deducible way. */
18050 static bool
18052 {
18054 {
18059 else
18060 {
18067 else
18069 }
18072 }
18074 }
18076 /* Returns true iff TYPE contains any deducible references to template
18077 parameters, as per 14.8.2.5. */
18079 static bool
18081 {
18085 /* T
18086 cv-list T
18087 TT<T>
18088 TT<i>
18089 TT<> */
18094 /* T*
18095 T&
18096 T&& */
18100 /* T[integer-constant ]
18101 type [i] */
18106 /* T type ::*
18107 type T::*
18108 T T::*
18109 T (type ::*)()
18110 type (T::*)()
18111 type (type ::*)(T)
18112 type (T::*)(T)
18113 T (type ::*)(T)
18114 T (T::*)()
18115 T (T::*)(T) */
18118 || (uses_deducible_template_parms
18121 /* template-name <T> (where template-name refers to a class template)
18122 template-name <i> (where template-name refers to a class template) */
18129 /* type (T)
18130 T()
18131 T(T) */
18134 {
18143 }
18146 }
18148 /* Subroutine of type_unification_real and unify_pack_expansion to
18149 handle unification of a single P/A pair. Parameters are as
18150 for those functions. */
18152 static int
18156 {
18163 /* We can't deduce anything from this, but we might get all the
18164 template args from other function args. */
18167 /* Implicit conversions (Clause 4) will be performed on a function
18168 argument to convert it to the type of the corresponding function
18169 parameter if the parameter type contains no template-parameters that
18170 participate in template argument deduction. */
18173 /* For function parameters with no deducible template parameters,
18174 just return. We'll check non-dependent conversions later. */
18178 {
18180 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
18181 | UNIFY_ALLOW_MORE_CV_QUAL
18195 }
18197 /* We only do these transformations if this is the top-level
18198 parameter_type_list in a call or declaration matching; in other
18199 situations (nested function declarators, template argument lists) we
18200 won't be comparing a type to an expression, and we don't do any type
18201 adjustments. */
18203 {
18205 {
18208 {
18209 /* [temp.deduct.type] A template-argument can be
18210 deduced from a pointer to function or pointer
18211 to member function argument if the set of
18212 overloaded functions does not contain function
18213 templates and at most one of a set of
18214 overloaded functions provides a unique
18215 match. */
18222 }
18228 }
18230 arg_strict |=
18232 }
18233 else
18238 /* For deduction from an init-list we need the actual list. */
18242 }
18244 /* Most parms like fn_type_unification.
18246 If SUBR is 1, we're being called recursively (to unify the
18247 arguments of a function or method parameter of a function
18248 template).
18250 CHECKS is a pointer to a vector of access checks encountered while
18251 substituting default template arguments. */
18253 static int
18255 tree targs,
18256 tree xparms,
18260 unification_kind_t strict,
18264 {
18269 tree parms;
18278 /* Reset the number of non-defaulted template arguments contained
18279 in TARGS. */
18282 again:
18290 {
18295 /* For a function parameter pack that occurs at the end of the
18296 parameter-declaration-list, the type A of each remaining
18297 argument of the call is compared with the type P of the
18298 declarator-id of the function parameter pack. */
18304 /* For a function parameter pack that does not occur at the
18305 end of the parameter-declaration-list, the type of the
18306 parameter pack is a non-deduced context. */
18313 explain_p))
18315 }
18320 {
18321 /* Unify the remaining arguments with the pack expansion type. */
18322 tree argvec;
18325 /* Allocate a TREE_VEC and copy in all of the arguments */
18330 /* Copy the parameter into parmvec. */
18336 /* Advance to the end of the list of parameters. */
18338 }
18340 /* Fail if we've reached the end of the parm list, and more args
18341 are present, and the parm list isn't variadic. */
18344 /* Fail if parms are left and they don't have default values and
18345 they aren't all deduced as empty packs (c++/57397). This is
18346 consistent with sufficient_parms_p. */
18349 {
18353 do
18354 {
18357 count++;
18359 }
18363 type_pack_p);
18364 }
18367 {
18368 tsubst_flags_t complain = (explain_p
18369 ? tf_warning_or_error
18373 {
18377 /* Clear the "incomplete" flags on all argument packs now so that
18378 substituting them into later default arguments works. */
18380 {
18383 }
18389 /* If this is an undeduced nontype parameter that depends on
18390 a type parameter, try another pass; its type may have been
18391 deduced from a later argument than the one from which
18392 this parameter can be deduced. */
18396 {
18399 }
18401 /* Core issue #226 (C++0x) [temp.deduct]:
18403 If a template argument has not been deduced, its
18404 default template argument, if any, is used.
18406 When we are in C++98 mode, TREE_PURPOSE will either
18407 be NULL_TREE or ERROR_MARK_NODE, so we do not need
18408 to explicitly check cxx_dialect here. */
18410 /* OK, there is a default argument. Wait until after the
18411 conversion check to do substitution. */
18414 /* If the type parameter is a parameter pack, then it will
18415 be deduced to an empty parameter pack. */
18417 {
18418 tree arg;
18421 {
18425 }
18426 else
18433 }
18436 }
18438 /* DR 1391: All parameters have args, now check non-dependent parms for
18439 convertibility. */
18443 {
18449 /* For a function parameter pack that occurs at the end of the
18450 parameter-declaration-list, the type A of each remaining
18451 argument of the call is compared with the type P of the
18452 declarator-id of the function parameter pack. */
18458 /* For a function parameter pack that does not occur at the
18459 end of the parameter-declaration-list, the type of the
18460 parameter pack is a non-deduced context. */
18469 explain_p))
18471 }
18473 /* Now substitute into the default template arguments. */
18475 {
18501 else
18502 {
18504 /* The position of the first default template argument,
18505 is also the number of non-defaulted arguments in TARGS.
18506 Record that. */
18510 }
18511 }
18515 }
18521 }
18523 /* Subroutine of type_unification_real. Args are like the variables
18524 at the call site. ARG is an overloaded function (or template-id);
18525 we try deducing template args from each of the overloads, and if
18526 only one succeeds, we go with that. Modifies TARGS and returns
18527 true on success. */
18529 static bool
18531 tree targs,
18532 tree parm,
18533 tree arg,
18534 unification_kind_t strict,
18537 {
18544 {
18547 }
18548 else
18552 /* Handle `&x' where `x' is some static or non-static member
18553 function name. */
18559 /* Strip baselink information. */
18564 {
18565 /* If we got some explicit template args, we need to plug them into
18566 the affected templates before we try to unify, in case the
18567 explicit args will completely resolve the templates in question. */
18574 {
18587 {
18592 {
18595 }
18596 }
18599 }
18600 /* If no templates (or more than one) are fully resolved by the
18601 explicit arguments, this template-id is a non-deduced context; it
18602 could still be OK if we deduce all template arguments for the
18603 enclosing call through other arguments. */
18606 }
18609 /* If ARG is, for example, "(0, &f)" then its type will be unknown
18610 -- but the deduction does not succeed because the expression is
18611 not just the function on its own. */
18613 else
18619 {
18622 }
18624 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18625 to function or pointer to member function argument if the set of
18626 overloaded functions does not contain function templates and at most
18627 one of a set of overloaded functions provides a unique match.
18629 So if we found multiple possibilities, we return success but don't
18630 deduce anything. */
18633 {
18637 {
18642 /* Don't forget explicit template arguments in a pack. */
18646 }
18647 }
18652 }
18654 /* Core DR 115: In contexts where deduction is done and fails, or in
18655 contexts where deduction is not done, if a template argument list is
18656 specified and it, along with any default template arguments, identifies
18657 a single function template specialization, then the template-id is an
18658 lvalue for the function template specialization. */
18660 tree
18662 {
18675 {
18678 }
18680 {
18683 }
18685 {
18688 }
18691 {
18695 /* If we got some explicit template args, we need to plug them into
18696 the affected templates before we try to unify, in case the
18697 explicit args will completely resolve the templates in question. */
18705 {
18718 {
18721 {
18724 }
18726 {
18729 }
18730 }
18731 }
18733 {
18741 {
18742 tree base
18745 }
18749 }
18751 /* There were no good options and at least one bad one, so let the
18752 user know what the problem is. */
18754 }
18756 }
18758 /* Subroutine of resolve_overloaded_unification; does deduction for a single
18759 overload. Fills TARGS with any deduced arguments, or error_mark_node if
18760 different overloads deduce different arguments for a given parm.
18761 ADDR_P is true if the expression for which deduction is being
18762 performed was of the form "& fn" rather than simply "fn".
18764 Returns 1 on success. */
18766 static int
18768 tree orig_targs,
18769 tree targs,
18770 tree parm,
18771 tree arg,
18772 unification_kind_t strict,
18776 {
18778 tree tempargs;
18784 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18785 to function or pointer to member function argument if the set of
18786 overloaded functions does not contain function templates and at most
18787 one of a set of overloaded functions provides a unique match.
18789 So if this is a template, just return success. */
18801 /* We don't copy orig_targs for this because if we have already deduced
18802 some template args from previous args, unify would complain when we
18803 try to deduce a template parameter for the same argument, even though
18804 there isn't really a conflict. */
18811 /* First make sure we didn't deduce anything that conflicts with
18812 explicitly specified args. */
18814 {
18821 /* Since we're unifying against ourselves, we will fill in
18822 template args used in the function parm list with our own
18823 template parms. Discard them. */
18826 {
18827 /* Check that the argument at each index of the deduced argument pack
18828 is equivalent to the corresponding explicitly specified argument.
18829 We may have deduced more arguments than were explicitly specified,
18830 and that's OK. */
18846 }
18849 }
18852 {
18857 }
18860 }
18862 /* PARM is a template class (perhaps with unbound template
18863 parameters). ARG is a fully instantiated type. If ARG can be
18864 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
18865 TARGS are as for unify. */
18867 static tree
18870 {
18871 tree copy_of_targs;
18878 /* We need to make a new template argument vector for the call to
18879 unify. If we used TARGS, we'd clutter it up with the result of
18880 the attempted unification, even if this class didn't work out.
18881 We also don't want to commit ourselves to all the unifications
18882 we've already done, since unification is supposed to be done on
18883 an argument-by-argument basis. In other words, consider the
18884 following pathological case:
18886 template <int I, int J, int K>
18887 struct S {};
18889 template <int I, int J>
18890 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
18892 template <int I, int J, int K>
18893 void f(S<I, J, K>, S<I, I, I>);
18895 void g() {
18896 S<0, 0, 0> s0;
18897 S<0, 1, 2> s2;
18899 f(s0, s2);
18900 }
18902 Now, by the time we consider the unification involving `s2', we
18903 already know that we must have `f<0, 0, 0>'. But, even though
18904 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
18905 because there are two ways to unify base classes of S<0, 1, 2>
18906 with S<I, I, I>. If we kept the already deduced knowledge, we
18907 would reject the possibility I=1. */
18910 /* If unification failed, we're done. */
18916 }
18918 /* Given a template type PARM and a class type ARG, find the unique
18919 base type in ARG that is an instance of PARM. We do not examine
18920 ARG itself; only its base-classes. If there is not exactly one
18921 appropriate base class, return NULL_TREE. PARM may be the type of
18922 a partial specialization, as well as a plain template type. Used
18923 by unify. */
18925 static enum template_base_result
18928 {
18930 tree binfo;
18936 {
18937 /* The type could not be completed. */
18940 }
18942 /* Walk in inheritance graph order. The search order is not
18943 important, and this avoids multiple walks of virtual bases. */
18945 {
18950 {
18951 /* If there is more than one satisfactory baseclass, then:
18953 [temp.deduct.call]
18955 If they yield more than one possible deduced A, the type
18956 deduction fails.
18958 applies. */
18960 {
18963 }
18966 }
18967 }
18971 }
18973 /* Returns the level of DECL, which declares a template parameter. */
18975 static int
18977 {
18979 {
18989 }
18991 }
18993 /* Decide whether ARG can be unified with PARM, considering only the
18994 cv-qualifiers of each type, given STRICT as documented for unify.
18995 Returns nonzero iff the unification is OK on that basis. */
18997 static int
18999 {
19005 {
19006 /* Although a CVR qualifier is ignored when being applied to a
19007 substituted template parameter ([8.3.2]/1 for example), that
19008 does not allow us to unify "const T" with "int&" because both
19009 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19010 It is ok when we're allowing additional CV qualifiers
19011 at the outer level [14.8.2.1]/3,1st bullet. */
19021 }
19032 }
19034 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19035 void
19037 {
19041 {
19044 }
19045 else
19046 {
19049 }
19050 }
19052 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19053 do { \
19054 if (unify (TP, TA, P, A, S, EP)) \
19055 return 1; \
19056 } while (0);
19058 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19059 expansion at the end of PACKED_PARMS. Returns 0 if the type
19060 deduction succeeds, 1 otherwise. STRICT is the same as in
19061 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
19062 call argument list. We'll need to adjust the arguments to make them
19063 types. SUBR tells us if this is from a recursive call to
19064 type_unification_real, or for comparing two template argument
19065 lists. */
19067 static int
19071 {
19072 tree parm
19082 /* Determine the parameter packs we will be deducing from the
19083 pattern, and record their current deductions. */
19086 {
19090 /* Determine the index and level of this parameter pack. */
19093 /* Keep track of the parameter packs and their corresponding
19094 argument packs. */
19097 }
19099 /* Loop through all of the arguments that have not yet been
19100 unified and unify each with the pattern. */
19102 {
19103 tree parm;
19107 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
19108 or the element of its argument pack at the current index if
19109 this argument was explicitly specified. */
19111 {
19120 {
19123 }
19125 }
19127 /* If we had explicit template arguments, substitute them into the
19128 pattern before deduction. */
19130 {
19131 /* Some arguments might still be unspecified or dependent. */
19139 NULL_TREE);
19144 }
19145 else
19148 /* Unify the pattern with the current argument. */
19150 explain_p))
19153 /* For each parameter pack, collect the deduced value. */
19155 {
19161 }
19162 }
19164 /* Verify that the results of unification with the parameter packs
19165 produce results consistent with what we've seen before, and make
19166 the deduced argument packs available. */
19168 {
19175 /* By default keep the original deduced argument pack.
19176 If necessary, more specific code is going to update the
19177 resulting deduced argument later down in this function. */
19181 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
19182 actually deduce anything. */
19190 {
19191 /* If we had fewer function args than explicit template args,
19192 just use the explicits. */
19197 }
19200 {
19201 tree result;
19202 /* Build the deduced *_ARGUMENT_PACK. */
19204 {
19209 }
19210 else
19215 /* Note the deduced argument packs for this parameter
19216 pack. */
19218 }
19222 {
19223 /* We only had the explicitly-provided arguments before, but
19224 now we have a complete set of arguments. */
19230 }
19231 else
19232 {
19238 /* Inconsistent unification of this parameter pack. */
19240 bad_old_arg,
19241 bad_new_arg);
19242 }
19243 }
19246 }
19248 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
19249 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
19250 parameters and return value are as for unify. */
19252 static int
19256 {
19257 tree parm_max;
19258 tree arg_max;
19262 /* Our representation of array types uses "N - 1" as the
19263 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
19264 not an integer constant. We cannot unify arbitrarily
19265 complex expressions, so we eliminate the MINUS_EXPRs
19266 here. */
19270 {
19273 }
19277 {
19278 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
19279 trying to unify the type of a variable with the type
19280 of a template parameter. For example:
19282 template <unsigned int N>
19283 void f (char (&) [N]);
19284 int g();
19285 void h(int i) {
19286 char a[g(i)];
19287 f(a);
19288 }
19290 Here, the type of the ARG will be "int [g(i)]", and
19291 may be a SAVE_EXPR, etc. */
19295 }
19297 /* If only one of the bounds used a MINUS_EXPR, compensate
19298 by adding one to the other bound. */
19301 integer_type_node,
19302 parm_max,
19303 integer_one_node);
19306 integer_type_node,
19307 arg_max,
19308 integer_one_node);
19312 }
19314 /* Deduce the value of template parameters. TPARMS is the (innermost)
19315 set of template parameters to a template. TARGS is the bindings
19316 for those template parameters, as determined thus far; TARGS may
19317 include template arguments for outer levels of template parameters
19318 as well. PARM is a parameter to a template function, or a
19319 subcomponent of that parameter; ARG is the corresponding argument.
19320 This function attempts to match PARM with ARG in a manner
19321 consistent with the existing assignments in TARGS. If more values
19322 are deduced, then TARGS is updated.
19324 Returns 0 if the type deduction succeeds, 1 otherwise. The
19325 parameter STRICT is a bitwise or of the following flags:
19327 UNIFY_ALLOW_NONE:
19328 Require an exact match between PARM and ARG.
19329 UNIFY_ALLOW_MORE_CV_QUAL:
19330 Allow the deduced ARG to be more cv-qualified (by qualification
19331 conversion) than ARG.
19332 UNIFY_ALLOW_LESS_CV_QUAL:
19333 Allow the deduced ARG to be less cv-qualified than ARG.
19334 UNIFY_ALLOW_DERIVED:
19335 Allow the deduced ARG to be a template base class of ARG,
19336 or a pointer to a template base class of the type pointed to by
19337 ARG.
19338 UNIFY_ALLOW_INTEGER:
19339 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
19340 case for more information.
19341 UNIFY_ALLOW_OUTER_LEVEL:
19342 This is the outermost level of a deduction. Used to determine validity
19343 of qualification conversions. A valid qualification conversion must
19344 have const qualified pointers leading up to the inner type which
19345 requires additional CV quals, except at the outer level, where const
19346 is not required [conv.qual]. It would be normal to set this flag in
19347 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
19348 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
19349 This is the outermost level of a deduction, and PARM can be more CV
19350 qualified at this point.
19351 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
19352 This is the outermost level of a deduction, and PARM can be less CV
19353 qualified at this point. */
19355 static int
19358 {
19360 tree targ;
19361 tree tparm;
19364 /* I don't think this will do the right thing with respect to types.
19365 But the only case I've seen it in so far has been array bounds, where
19366 signedness is the only information lost, and I think that will be
19367 okay. */
19375 /* We can't deduce anything from this, but we might get all the
19376 template args from other function args. */
19379 /* If PARM uses template parameters, then we can't bail out here,
19380 even if ARG == PARM, since we won't record unifications for the
19381 template parameters. We might need them if we're trying to
19382 figure out which of two things is more specialized. */
19386 /* Handle init lists early, so the rest of the function can assume
19387 we're dealing with a type. */
19389 {
19394 /* Replace T with std::initializer_list<T> for deduction. */
19401 /* We can only deduce from an initializer list argument if the
19402 parameter is std::initializer_list or an array; otherwise this
19403 is a non-deduced context. */
19408 else
19409 {
19411 /* Deduction is defined in terms of a single type, so just punt
19412 on the (bizarre) std::initializer_list<T...>. */
19415 }
19418 {
19425 {
19429 /* It should only be possible to get here for a call. */
19431 elt_strict |= maybe_adjust_types_for_deduction
19434 }
19437 explain_p);
19438 }
19442 {
19443 /* Also deduce from the length of the initializer list. */
19450 }
19452 /* If the std::initializer_list<T> deduction worked, replace the
19453 deduced A with std::initializer_list<A>. */
19455 {
19460 }
19462 }
19464 /* Immediately reject some pairs that won't unify because of
19465 cv-qualification mismatches. */
19468 /* It is the elements of the array which hold the cv quals of an array
19469 type, and the elements might be template type parms. We'll check
19470 when we recurse. */
19472 /* We check the cv-qualifiers when unifying with template type
19473 parameters below. We want to allow ARG `const T' to unify with
19474 PARM `T' for example, when computing which of two templates
19475 is more specialized, for example. */
19489 {
19493 /* In a type which contains a nested-name-specifier, template
19494 argument values cannot be deduced for template parameters used
19495 within the nested-name-specifier. */
19507 /* The PARM is not one we're trying to unify. Just check
19508 to see if it matches ARG. */
19509 {
19514 else
19516 }
19523 /* Check for mixed types and values. */
19531 {
19532 /* ARG must be constructed from a template class or a template
19533 template parameter. */
19537 {
19539 /* An alias template name is never deduced. */
19544 tree parm_parms
19545 = DECL_INNERMOST_TEMPLATE_PARMS
19550 /* The resolution to DR150 makes clear that default
19551 arguments for an N-argument may not be used to bind T
19552 to a template template parameter with fewer than N
19553 parameters. It is not safe to permit the binding of
19554 default arguments as an extension, as that may change
19555 the meaning of a conforming program. Consider:
19557 struct Dense { static const unsigned int dim = 1; };
19559 template <template <typename> class View,
19560 typename Block>
19561 void operator+(float, View<Block> const&);
19563 template <typename Block,
19564 unsigned int Dim = Block::dim>
19565 struct Lvalue_proxy { operator float() const; };
19567 void
19568 test_1d (void) {
19569 Lvalue_proxy<Dense> p;
19570 float b;
19571 b + p;
19572 }
19574 Here, if Lvalue_proxy is permitted to bind to View, then
19575 the global operator+ will be used; if they are not, the
19576 Lvalue_proxy will be converted to float. */
19578 full_argvec,
19580 (explain_p
19581 ? tf_warning_or_error
19588 /* Deduce arguments T, i from TT<T> or TT<i>.
19589 We check each element of PARMVEC and ARGVEC individually
19590 rather than the whole TREE_VEC since they can have
19591 different number of elements. */
19598 /* Check if the parameters end in a pack, making them
19599 variadic. */
19605 /* If the template argument list of P contains a pack
19606 expansion that is not the last template argument, the
19607 entire template argument list is a non-deduced
19608 context. */
19617 {
19622 }
19627 DEDUCE_EXACT,
19630 }
19633 /* Fall through to deduce template name. */
19634 }
19638 {
19639 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
19641 /* Simple cases: Value already set, does match or doesn't. */
19646 }
19647 else
19648 {
19649 /* If PARM is `const T' and ARG is only `int', we don't have
19650 a match unless we are allowing additional qualification.
19651 If ARG is `const int' and PARM is just `T' that's OK;
19652 that binds `const int' to `T'. */
19657 /* Consider the case where ARG is `const volatile int' and
19658 PARM is `const T'. Then, T should be `volatile int'. */
19659 arg = cp_build_qualified_type_real
19664 /* Simple cases: Value already set, does match or doesn't. */
19670 /* Make sure that ARG is not a variable-sized array. (Note
19671 that were talking about variable-sized arrays (like
19672 `int[n]'), rather than arrays of unknown size (like
19673 `int[]').) We'll get very confused by such a type since
19674 the bound of the array is not constant, and therefore
19675 not mangleable. Besides, such types are not allowed in
19676 ISO C++, so we can do as we please here. We do allow
19677 them for 'auto' deduction, since that isn't ABI-exposed. */
19681 /* Strip typedefs as in convert_template_argument. */
19683 }
19685 /* If ARG is a parameter pack or an expansion, we cannot unify
19686 against it unless PARM is also a parameter pack. */
19691 /* If the argument deduction results is a METHOD_TYPE,
19692 then there is a problem.
19693 METHOD_TYPE doesn't map to any real C++ type the result of
19694 the deduction can not be of that type. */
19708 {
19709 /* The PARM is not one we're trying to unify. Just check
19710 to see if it matches ARG. */
19716 }
19722 {
19727 }
19729 /* [temp.deduct.type] If, in the declaration of a function template
19730 with a non-type template-parameter, the non-type
19731 template-parameter is used in an expression in the function
19732 parameter-list and, if the corresponding template-argument is
19733 deduced, the template-argument type shall match the type of the
19734 template-parameter exactly, except that a template-argument
19735 deduced from an array bound may be of any integral type.
19736 The non-type parameter might use already deduced type parameters. */
19739 /* Template-parameter dependent expression. Just accept it for now.
19740 It will later be processed in convert_template_argument. */
19741 ;
19746 /* Convert the ARG to the type of PARM; the deduced non-type
19747 template argument must exactly match the types of the
19748 corresponding parameter. */
19751 /* We haven't deduced the type of this parameter yet. Try again
19752 later. */
19754 else
19757 /* If ARG is a parameter pack or an expansion, we cannot unify
19758 against it unless PARM is also a parameter pack. */
19763 {
19766 }
19771 {
19772 /* A pointer-to-member constant can be unified only with
19773 another constant. */
19777 /* Just unify the class member. It would be useless (and possibly
19778 wrong, depending on the strict flags) to unify also
19779 PTRMEM_CST_CLASS, because we want to be sure that both parm and
19780 arg refer to the same variable, even if through different
19781 classes. For instance:
19783 struct A { int x; };
19784 struct B : A { };
19786 Unification of &A::x and &B::x must succeed. */
19789 }
19792 {
19796 /* [temp.deduct.call]
19798 A can be another pointer or pointer to member type that can
19799 be converted to the deduced A via a qualification
19800 conversion (_conv.qual_).
19802 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
19803 This will allow for additional cv-qualification of the
19804 pointed-to types if appropriate. */
19807 /* The derived-to-base conversion only persists through one
19808 level of pointers. */
19813 }
19845 /* We have already checked cv-qualification at the top of the
19846 function. */
19850 /* As far as unification is concerned, this wins. Later checks
19851 will invalidate it if necessary. */
19854 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
19855 /* Type INTEGER_CST can come from ordinary constant template args. */
19867 {
19877 /* Check for pack expansions in the parameters. */
19879 {
19881 {
19883 /* We can unify against something with a trailing
19884 parameter pack. */
19886 else
19887 /* [temp.deduct.type]/9: If the template argument list of
19888 P contains a pack expansion that is not the last
19889 template argument, the entire template argument list
19890 is a non-deduced context. */
19892 }
19893 }
19895 /* If we don't have enough arguments to satisfy the parameters
19896 (not counting the pack expression at the end), or we have
19897 too many arguments for a parameter list that doesn't end in
19898 a pack expression, we can't unify. */
19904 /* Unify all of the parameters that precede the (optional)
19905 pack expression. */
19907 {
19912 }
19915 DEDUCE_EXACT,
19918 }
19926 {
19934 }
19939 {
19943 {
19944 /* First, we try to unify the PARM and ARG directly. */
19949 {
19950 /* Fallback to the special case allowed in
19951 [temp.deduct.call]:
19953 If P is a class, and P has the form
19954 template-id, then A can be a derived class of
19955 the deduced A. Likewise, if P is a pointer to
19956 a class of the form template-id, A can be a
19957 pointer to a derived class pointed to by the
19958 deduced A. */
19964 {
19965 /* Don't give the derived diagnostic if we're
19966 already dealing with the same template. */
19967 bool same_template
19973 }
19974 }
19975 }
19979 /* Perhaps PARM is something like S<U> and ARG is S<int>.
19980 Then, we should unify `int' and `U'. */
19982 else
19983 /* There's no chance of unification succeeding. */
19988 }
19995 {
19998 tree a;
20004 /* CV qualifications for methods can never be deduced, they must
20005 match exactly. We need to check them explicitly here,
20006 because type_unification_real treats them as any other
20007 cv-qualified parameter. */
20009 && (!check_cv_quals_for_unify
20029 }
20032 /* Unify a pointer to member with a pointer to member function, which
20033 deduces the type of the member as a function type. */
20035 {
20036 /* Check top-level cv qualifiers */
20044 /* Determine the type of the function we are unifying against. */
20048 }
20067 /* Matched cases are handled by the ARG == PARM test above. */
20071 /* We might get a variable as a non-type template argument in parm if the
20072 corresponding parameter is type-dependent. Make any necessary
20073 adjustments based on whether arg is a reference. */
20077 {
20082 }
20083 /* Now use the normal expression code to check whether they match. */
20094 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
20095 or UNDERLYING_TYPE nodes. */
20099 /* Unification fails if we hit an error node. */
20104 {
20109 }
20110 /* FALLTHRU */
20113 /* An unresolved overload is a nondeduced context. */
20117 expr:
20118 /* We must be looking at an expression. This can happen with
20119 something like:
20121 template <int I>
20122 void foo(S<I>, S<I + 2>);
20124 This is a "nondeduced context":
20126 [deduct.type]
20128 The nondeduced contexts are:
20130 --A type that is a template-id in which one or more of
20131 the template-arguments is an expression that references
20132 a template-parameter.
20134 In these cases, we assume deduction succeeded, but don't
20135 actually infer any unifications. */
20140 else
20142 }
20143 }
20144 #undef RECUR_AND_CHECK_FAILURE
20145 \f
20146 /* Note that DECL can be defined in this translation unit, if
20147 required. */
20149 static void
20151 {
20152 tree clone;
20156 }
20158 /* Called if RESULT is explicitly instantiated, or is a member of an
20159 explicitly instantiated class. */
20161 void
20163 {
20166 /* If this entity has already been written out, it's too late to
20167 make any modifications. */
20171 /* For anonymous namespace we don't need to do anything. */
20173 {
20176 }
20179 /* The TREE_PUBLIC flag for function declarations will have been
20180 set correctly by tsubst. */
20183 /* This might have been set by an earlier implicit instantiation. */
20188 else
20189 {
20192 /* Always make artificials weak. */
20195 /* For WIN32 we also want to put explicit instantiations in
20196 linkonce sections. */
20199 }
20201 /* If EXTERN_P, then this function will not be emitted -- unless
20202 followed by an explicit instantiation, at which point its linkage
20203 will be adjusted. If !EXTERN_P, then this function will be
20204 emitted here. In neither circumstance do we want
20205 import_export_decl to adjust the linkage. */
20207 }
20209 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
20210 important template arguments. If any are missing, we check whether
20211 they're important by using error_mark_node for substituting into any
20212 args that were used for partial ordering (the ones between ARGS and END)
20213 and seeing if it bubbles up. */
20215 static bool
20217 {
20222 {
20225 }
20227 {
20231 }
20233 }
20235 /* Given two function templates PAT1 and PAT2, return:
20237 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
20238 -1 if PAT2 is more specialized than PAT1.
20239 0 if neither is more specialized.
20241 LEN indicates the number of parameters we should consider
20242 (defaulted parameters should not be considered).
20244 The 1998 std underspecified function template partial ordering, and
20245 DR214 addresses the issue. We take pairs of arguments, one from
20246 each of the templates, and deduce them against each other. One of
20247 the templates will be more specialized if all the *other*
20248 template's arguments deduce against its arguments and at least one
20249 of its arguments *does* *not* deduce against the other template's
20250 corresponding argument. Deduction is done as for class templates.
20251 The arguments used in deduction have reference and top level cv
20252 qualifiers removed. Iff both arguments were originally reference
20253 types *and* deduction succeeds in both directions, an lvalue reference
20254 wins against an rvalue reference and otherwise the template
20255 with the more cv-qualified argument wins for that pairing (if
20256 neither is more cv-qualified, they both are equal). Unlike regular
20257 deduction, after all the arguments have been deduced in this way,
20258 we do *not* verify the deduced template argument values can be
20259 substituted into non-deduced contexts.
20261 The logic can be a bit confusing here, because we look at deduce1 and
20262 targs1 to see if pat2 is at least as specialized, and vice versa; if we
20263 can find template arguments for pat1 to make arg1 look like arg2, that
20264 means that arg2 is at least as specialized as arg1. */
20266 int
20268 {
20281 /* Remove the this parameter from non-static member functions. If
20282 one is a non-static member function and the other is not a static
20283 member function, remove the first parameter from that function
20284 also. This situation occurs for operator functions where we
20285 locate both a member function (with this pointer) and non-member
20286 operator (with explicit first operand). */
20288 {
20293 }
20295 {
20298 {
20299 len--;
20301 }
20302 }
20304 /* If only one is a conversion operator, they are unordered. */
20308 /* Consider the return type for a conversion function */
20310 {
20313 len++;
20314 }
20316 processing_template_decl++;
20322 /* Stop when an ellipsis is seen. */
20324 {
20335 {
20336 /* When both arguments are pack expansions, we need only
20337 unify the patterns themselves. */
20341 /* This is the last comparison we need to do. */
20343 }
20346 {
20350 }
20353 {
20357 }
20363 {
20369 /* Setup the parameter vector, which contains only ARG1. */
20372 /* Setup the argument vector, which contains the remaining
20373 arguments. */
20382 /* We cannot deduce in the other direction, because ARG1 is
20383 a pack expansion but ARG2 is not. */
20385 }
20387 {
20393 /* Setup the parameter vector, which contains only ARG1. */
20396 /* Setup the argument vector, which contains the remaining
20397 arguments. */
20406 /* We cannot deduce in the other direction, because ARG2 is
20407 a pack expansion but ARG1 is not.*/
20409 }
20411 else
20412 {
20413 /* The normal case, where neither argument is a pack
20414 expansion. */
20421 }
20423 /* If we couldn't deduce arguments for tparms1 to make arg1 match
20424 arg2, then arg2 is not as specialized as arg1. */
20430 /* "If, for a given type, deduction succeeds in both directions
20431 (i.e., the types are identical after the transformations above)
20432 and both P and A were reference types (before being replaced with
20433 the type referred to above):
20434 - if the type from the argument template was an lvalue reference and
20435 the type from the parameter template was not, the argument type is
20436 considered to be more specialized than the other; otherwise,
20437 - if the type from the argument template is more cv-qualified
20438 than the type from the parameter template (as described above),
20439 the argument type is considered to be more specialized than the other;
20440 otherwise,
20441 - neither type is more specialized than the other." */
20444 {
20446 {
20449 else
20451 }
20453 {
20458 }
20459 }
20462 /* We've failed to deduce something in either direction.
20463 These must be unordered. */
20468 /* We have already processed all of the arguments in our
20469 handing of the pack expansion type. */
20474 }
20476 /* "In most cases, all template parameters must have values in order for
20477 deduction to succeed, but for partial ordering purposes a template
20478 parameter may remain without a value provided it is not used in the
20479 types being used for partial ordering."
20481 Thus, if we are missing any of the targs1 we need to substitute into
20482 origs1, then pat2 is not as specialized as pat1. This can happen when
20483 there is a nondeduced context. */
20489 processing_template_decl--;
20491 /* If both deductions succeed, the partial ordering selects the more
20492 constrained template. */
20494 {
20499 }
20501 /* All things being equal, if the next argument is a pack expansion
20502 for one function but not for the other, prefer the
20503 non-variadic function. FIXME this is bogus; see c++/41958. */
20507 {
20510 }
20516 else
20518 }
20520 /* Determine which of two partial specializations of TMPL is more
20521 specialized.
20523 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
20524 to the first partial specialization. The TREE_PURPOSE is the
20525 innermost set of template parameters for the partial
20526 specialization. PAT2 is similar, but for the second template.
20528 Return 1 if the first partial specialization is more specialized;
20529 -1 if the second is more specialized; 0 if neither is more
20530 specialized.
20532 See [temp.class.order] for information about determining which of
20533 two templates is more specialized. */
20535 static int
20537 {
20538 tree targs;
20549 /* Just like what happens for functions, if we are ordering between
20550 different template specializations, we may encounter dependent
20551 types in the arguments, and we need our dependency check functions
20552 to behave correctly. */
20556 {
20559 }
20563 {
20566 }
20569 /* If both deductions succeed, the partial ordering selects the more
20570 constrained template. */
20574 /* In the case of a tie where at least one of the templates
20575 has a parameter pack at the end, the template with the most
20576 non-packed parameters wins. */
20578 && any_deductions
20581 {
20587 /* We don't count the pack expansion at the end. */
20597 }
20600 }
20602 /* Return the template arguments that will produce the function signature
20603 DECL from the function template FN, with the explicit template
20604 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
20605 also match. Return NULL_TREE if no satisfactory arguments could be
20606 found. */
20608 static tree
20610 {
20614 tree decl_arg_types;
20617 tree arg;
20621 /* Never do unification on the 'this' parameter. */
20642 }
20644 /* Return the innermost template arguments that, when applied to a partial
20645 specialization of TMPL whose innermost template parameters are
20646 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
20647 ARGS.
20649 For example, suppose we have:
20651 template <class T, class U> struct S {};
20652 template <class T> struct S<T*, int> {};
20654 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
20655 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
20656 int}. The resulting vector will be {double}, indicating that `T'
20657 is bound to `double'. */
20659 static tree
20661 {
20663 tree deduced_args;
20664 tree innermost_deduced_args;
20668 {
20672 innermost_deduced_args);
20673 }
20674 else
20687 /* Verify that nondeduced template arguments agree with the type
20688 obtained from argument deduction.
20690 For example:
20692 struct A { typedef int X; };
20693 template <class T, class U> struct C {};
20694 template <class T> struct C<T, typename T::X> {};
20696 Then with the instantiation `C<A, int>', we can deduce that
20697 `T' is `A' but unify () does not check whether `typename T::X'
20698 is `int'. */
20704 /* We only need to check the innermost arguments; the other
20705 arguments will always agree. */
20710 /* Now that we have bindings for all of the template arguments,
20711 ensure that the arguments deduced for the template template
20712 parameters have compatible template parameter lists. See the use
20713 of template_template_parm_bindings_ok_p in fn_type_unification
20714 for more information. */
20719 }
20721 // Compare two function templates T1 and T2 by deducing bindings
20722 // from one against the other. If both deductions succeed, compare
20723 // constraints to see which is more constrained.
20724 static int
20726 {
20731 {
20734 }
20737 {
20740 }
20742 // If both deductions succeed, then one may be more constrained.
20747 }
20749 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
20750 Return the TREE_LIST node with the most specialized template, if
20751 any. If there is no most specialized template, the error_mark_node
20752 is returned.
20754 Note that this function does not look at, or modify, the
20755 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
20756 returned is one of the elements of INSTANTIATIONS, callers may
20757 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
20758 and retrieve it from the value returned. */
20760 tree
20762 {
20769 {
20774 {
20775 /* Equally specialized, move to next function. If there
20776 is no next function, nothing's most specialized. */
20781 }
20782 }
20785 /* Now verify that champ is better than everything earlier in the
20786 instantiation list. */
20789 {
20792 }
20793 }
20795 processing_template_decl--;
20801 }
20803 /* If DECL is a specialization of some template, return the most
20804 general such template. Otherwise, returns NULL_TREE.
20806 For example, given:
20808 template <class T> struct S { template <class U> void f(U); };
20810 if TMPL is `template <class U> void S<int>::f(U)' this will return
20811 the full template. This function will not trace past partial
20812 specializations, however. For example, given in addition:
20814 template <class T> struct S<T*> { template <class U> void f(U); };
20816 if TMPL is `template <class U> void S<int*>::f(U)' this will return
20817 `template <class T> template <class U> S<T*>::f(U)'. */
20819 tree
20821 {
20823 {
20826 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
20827 template friend, or a FIELD_DECL for a capture pack. */
20830 }
20832 /* Look for more and more general templates. */
20834 {
20835 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
20836 (See cp-tree.h for details.) */
20845 /* Stop if we run into an explicitly specialized class template. */
20852 }
20855 }
20857 /* True iff the TEMPLATE_DECL tmpl is a partial specialization. */
20859 static bool
20861 {
20862 /* Any specialization has DECL_TEMPLATE_SPECIALIZATION. */
20866 /* A specialization that fully specializes one of the containing classes is
20867 not a partial specialization. */
20870 }
20872 /* If TMPL is a partial specialization, return the arguments for its primary
20873 template. */
20875 static tree
20877 {
20881 /* If TMPL is a partial specialization, we need to substitute to get
20882 the args for the primary template. */
20885 }
20887 /* Return the most specialized of the template partial specializations
20888 which can produce TARGET, a specialization of some class or variable
20889 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
20890 a TEMPLATE_DECL node corresponding to the partial specialization, while
20891 the TREE_PURPOSE is the set of template arguments that must be
20892 substituted into the template pattern in order to generate TARGET.
20894 If the choice of partial specialization is ambiguous, a diagnostic
20895 is issued, and the error_mark_node is returned. If there are no
20896 partial specializations matching TARGET, then NULL_TREE is
20897 returned, indicating that the primary template should be used. */
20899 static tree
20901 {
20903 tree t;
20904 tree champ;
20911 {
20915 }
20917 {
20920 }
20922 {
20926 }
20927 else
20932 /* For determining which partial specialization to use, only the
20933 innermost args are interesting. */
20935 {
20938 }
20941 {
20942 tree partial_spec_args;
20943 tree spec_args;
20951 {
20952 /* Discard the outer levels of args, and then substitute in the
20953 template args from the enclosing class. */
20955 partial_spec_args = tsubst_template_args
20958 /* And the same for the partial specialization TEMPLATE_DECL. */
20960 }
20962 partial_spec_args =
20964 partial_spec_args,
20978 partial_spec_args,
20979 args);
20981 {
20985 /* Keep the candidate only if the constraints are satisfied,
20986 or if we're not compiling with concepts. */
20989 {
20992 }
20993 }
20994 }
21004 {
21007 ;
21008 else
21009 {
21011 {
21014 {
21017 }
21018 }
21020 }
21021 }
21025 {
21028 {
21031 }
21032 }
21035 {
21042 else
21046 {
21051 }
21054 }
21057 }
21059 /* Explicitly instantiate DECL. */
21061 void
21063 {
21068 /* An error occurred, for which grokdeclarator has already issued
21069 an appropriate message. */
21072 {
21075 }
21081 {
21082 /* There is an asymmetry here in the way VAR_DECLs and
21083 FUNCTION_DECLs are handled by grokdeclarator. In the case of
21084 the latter, the DECL we get back will be marked as a
21085 template instantiation, and the appropriate
21086 DECL_TEMPLATE_INFO will be set up. This does not happen for
21087 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
21088 should handle VAR_DECLs as it currently handles
21089 FUNCTION_DECLs. */
21091 {
21094 }
21097 {
21100 }
21102 {
21107 }
21108 }
21110 {
21113 }
21114 else
21117 /* Check for various error cases. Note that if the explicit
21118 instantiation is valid the RESULT will currently be marked as an
21119 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
21120 until we get here. */
21123 {
21124 /* DR 259 [temp.spec].
21126 Both an explicit instantiation and a declaration of an explicit
21127 specialization shall not appear in a program unless the explicit
21128 instantiation follows a declaration of the explicit specialization.
21130 For a given set of template parameters, if an explicit
21131 instantiation of a template appears after a declaration of an
21132 explicit specialization for that template, the explicit
21133 instantiation has no effect. */
21135 }
21137 {
21138 /* [temp.spec]
21140 No program shall explicitly instantiate any template more
21141 than once.
21143 We check DECL_NOT_REALLY_EXTERN so as not to complain when
21144 the first instantiation was `extern' and the second is not,
21145 and EXTERN_P for the opposite case. */
21148 /* If an "extern" explicit instantiation follows an ordinary
21149 explicit instantiation, the template is instantiated. */
21152 }
21154 {
21157 }
21159 {
21162 }
21165 ;
21167 {
21170 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
21173 }
21174 else
21182 }
21184 static void
21186 {
21192 {
21195 }
21196 }
21198 /* Called from do_type_instantiation through binding_table_foreach to
21199 do recursive instantiation for the type bound in ENTRY. */
21200 static void
21202 {
21208 }
21210 /* Called from do_type_instantiation to instantiate a member
21211 (a member function or a static member variable) of an
21212 explicitly instantiated class template. */
21213 static void
21215 {
21220 }
21222 /* Perform an explicit instantiation of template class T. STORAGE, if
21223 non-null, is the RID for extern, inline or static. COMPLAIN is
21224 nonzero if this is called from the parser, zero if called recursively,
21225 since the standard is unclear (as detailed below). */
21227 void
21229 {
21239 {
21240 tree tmpl =
21244 else
21247 }
21252 {
21255 t);
21257 }
21260 {
21262 {
21264 {
21267 "ISO C++ 1998 forbids the use of %<extern%> on "
21269 }
21270 else
21272 "ISO C++ forbids the use of %qE"
21274 }
21282 else
21283 {
21285 storage);
21287 }
21288 }
21291 {
21292 /* DR 259 [temp.spec].
21294 Both an explicit instantiation and a declaration of an explicit
21295 specialization shall not appear in a program unless the explicit
21296 instantiation follows a declaration of the explicit specialization.
21298 For a given set of template parameters, if an explicit
21299 instantiation of a template appears after a declaration of an
21300 explicit specialization for that template, the explicit
21301 instantiation has no effect. */
21303 }
21305 {
21306 /* [temp.spec]
21308 No program shall explicitly instantiate any template more
21309 than once.
21311 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
21312 instantiation was `extern'. If EXTERN_P then the second is.
21313 These cases are OK. */
21320 /* If we've already instantiated the template, just return now. */
21323 }
21331 {
21332 tree tmp;
21334 /* In contrast to implicit instantiation, where only the
21335 declarations, and not the definitions, of members are
21336 instantiated, we have here:
21338 [temp.explicit]
21340 The explicit instantiation of a class template specialization
21341 implies the instantiation of all of its members not
21342 previously explicitly specialized in the translation unit
21343 containing the explicit instantiation.
21345 Of course, we can't instantiate member template classes, since
21346 we don't have any arguments for them. Note that the standard
21347 is unclear on whether the instantiation of the members are
21348 *explicit* instantiations or not. However, the most natural
21349 interpretation is that it should be an explicit instantiation. */
21364 }
21365 }
21367 /* Given a function DECL, which is a specialization of TMPL, modify
21368 DECL to be a re-instantiation of TMPL with the same template
21369 arguments. TMPL should be the template into which tsubst'ing
21370 should occur for DECL, not the most general template.
21372 One reason for doing this is a scenario like this:
21374 template <class T>
21375 void f(const T&, int i);
21377 void g() { f(3, 7); }
21379 template <class T>
21380 void f(const T& t, const int i) { }
21382 Note that when the template is first instantiated, with
21383 instantiate_template, the resulting DECL will have no name for the
21384 first parameter, and the wrong type for the second. So, when we go
21385 to instantiate the DECL, we regenerate it. */
21387 static void
21389 {
21390 /* The arguments used to instantiate DECL, from the most general
21391 template. */
21392 tree args;
21393 tree code_pattern;
21398 /* Make sure that we can see identifiers, and compute access
21399 correctly. */
21403 {
21404 tree decl_parm;
21405 tree pattern_parm;
21406 tree specs;
21420 specs);
21422 /* Merge parameter declarations. */
21425 pattern_parm
21429 {
21430 tree parm_type;
21431 tree attributes;
21436 NULL_TREE);
21442 {
21445 }
21448 }
21449 /* Merge any parameters that match with the function parameter
21450 pack. */
21452 {
21454 tree expanded_types;
21455 /* Expand the TYPE_PACK_EXPANSION that provides the types for
21456 the parameters in this function parameter pack. */
21461 {
21462 tree parm_type;
21463 tree attributes;
21466 /* Rename the parameter to include the index. */
21475 {
21478 }
21480 }
21481 }
21482 /* Merge additional specifiers from the CODE_PATTERN. */
21486 }
21488 {
21496 }
21497 else
21501 }
21503 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
21504 substituted to get DECL. */
21506 tree
21508 {
21511 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
21512 for the instantiation. This is not always the most general
21513 template. Consider, for example:
21515 template <class T>
21516 struct S { template <class U> void f();
21517 template <> void f<int>(); };
21519 and an instantiation of S<double>::f<int>. We want TD to be the
21520 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
21522 more general template. */
21524 /* We must also deal with friend templates. Given:
21526 template <class T> struct S {
21527 template <class U> friend void f() {};
21528 };
21530 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
21531 so far as the language is concerned, but that's still
21532 where we get the pattern for the instantiation from. On
21533 other hand, if the definition comes outside the class, say:
21535 template <class T> struct S {
21536 template <class U> friend void f();
21537 };
21538 template <class U> friend void f() {}
21540 we don't need to look any further. That's what the check for
21541 DECL_INITIAL is for. */
21545 {
21546 /* The present template, TD, should not be a definition. If it
21547 were a definition, we should be using it! Note that we
21548 cannot restructure the loop to just keep going until we find
21549 a template with a definition, since that might go too far if
21550 a specialization was declared, but not defined. */
21552 /* Fetch the more general template. */
21554 }
21557 }
21559 /* Returns true if we need to instantiate this template instance even if we
21560 know we aren't going to emit it. */
21562 bool
21564 {
21565 /* We always instantiate inline functions so that we can inline them. An
21566 explicit instantiation declaration prohibits implicit instantiation of
21567 non-inline functions. With high levels of optimization, we would
21568 normally inline non-inline functions -- but we're not allowed to do
21569 that for "extern template" functions. Therefore, we check
21570 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
21574 /* And we need to instantiate static data members so that
21575 their initializers are available in integral constant
21576 expressions. */
21579 }
21581 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
21582 instantiate it now, modifying TREE_TYPE (fn). */
21584 void
21586 {
21589 /* Don't instantiate a noexcept-specification from template context. */
21604 {
21608 {
21623 }
21624 else
21628 }
21631 {
21634 else
21636 }
21637 }
21639 /* Produce the definition of D, a _DECL generated from a template. If
21640 DEFER_OK is nonzero, then we don't have to actually do the
21641 instantiation now; we just have to do it sometime. Normally it is
21642 an error if this is an explicit instantiation but D is undefined.
21643 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
21644 explicitly instantiated class template. */
21646 tree
21649 {
21651 tree gen_args;
21652 tree args;
21653 tree td;
21654 tree code_pattern;
21655 tree spec;
21656 tree gen_tmpl;
21663 tree fn_context;
21666 /* This function should only be used to instantiate templates for
21667 functions and static member variables. */
21670 /* A concept is never instantiated. */
21673 /* Variables are never deferred; if instantiation is required, they
21674 are instantiated right away. That allows for better code in the
21675 case that an expression refers to the value of the variable --
21676 if the variable has a constant value the referring expression can
21677 take advantage of that fact. */
21682 /* Don't instantiate cloned functions. Instead, instantiate the
21683 functions they cloned. */
21691 /* D has already been instantiated or explicitly specialized, so
21692 there's nothing for us to do here.
21694 It might seem reasonable to check whether or not D is an explicit
21695 instantiation, and, if so, stop here. But when an explicit
21696 instantiation is deferred until the end of the compilation,
21697 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
21698 the instantiation. */
21701 /* Check to see whether we know that this template will be
21702 instantiated in some other file, as with "extern template"
21703 extension. */
21706 /* In general, we do not instantiate such templates. */
21714 /* We should already have the extra args. */
21717 /* And what's in the hash table should match D. */
21721 /* This needs to happen before any tsubsting. */
21727 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
21728 for the instantiation. */
21732 /* We should never be trying to instantiate a member of a class
21733 template or partial specialization. */
21738 /* In the case of a friend template whose definition is provided
21739 outside the class, we may have too many arguments. Drop the
21740 ones we don't need. The same is true for specializations. */
21741 args = get_innermost_template_args
21743 else
21747 {
21753 }
21754 else
21755 {
21758 }
21760 /* We may be in the middle of deferred access check. Disable it now. */
21763 /* Unless an explicit instantiation directive has already determined
21764 the linkage of D, remember that a definition is available for
21765 this entity. */
21775 /* If D is a member of an explicitly instantiated class template,
21776 and no definition is available, treat it like an implicit
21777 instantiation. */
21780 {
21781 /* Leave linkage flags alone on instantiations with anonymous
21782 visibility. */
21784 {
21787 }
21789 }
21791 /* Defer all other templates, unless we have been explicitly
21792 forbidden from doing so. */
21794 template. */
21795 ! pattern_defined
21796 /* If it's OK to postpone instantiation, do so. */
21797 || defer_ok
21798 /* If this is a static data member that will be defined
21799 elsewhere, we don't want to instantiate the entire data
21800 member, but we do want to instantiate the initializer so that
21801 we can substitute that elsewhere. */
21803 /* Handle here a deleted function too, avoid generating
21804 its body (c++/61080). */
21806 {
21807 /* The definition of the static data member is now required so
21808 we must substitute the initializer. */
21812 {
21813 tree ns;
21814 tree init;
21823 args,
21826 /* If instantiating the initializer involved instantiating this
21827 again, don't call cp_finish_decl twice. */
21829 {
21830 /* Make sure the initializer is still constant, in case of
21831 circular dependency (template/instantiate6.C). */
21832 const_init
21836 LOOKUP_ONLYCONVERTING);
21837 }
21841 }
21843 /* We restore the source position here because it's used by
21844 add_pending_template. */
21850 /* [temp.explicit]
21852 The definition of a non-exported function template, a
21853 non-exported member function template, or a non-exported
21854 member function or static data member of a class template
21855 shall be present in every translation unit in which it is
21856 explicitly instantiated. */
21860 /* If we're in unevaluated context, we just wanted to get the
21861 constant value; this isn't an odr use, so don't queue
21862 a full instantiation. */
21865 /* ??? Historically, we have instantiated inline functions, even
21866 when marked as "extern template". */
21870 }
21871 /* Tell the repository that D is available in this translation unit
21872 -- and see if it is supposed to be instantiated here. */
21874 {
21875 /* In a PCH file, despite the fact that the repository hasn't
21876 requested instantiation in the PCH it is still possible that
21877 an instantiation will be required in a file that includes the
21878 PCH. */
21881 /* Instantiate inline functions so that the inliner can do its
21882 job, even though we'll not be emitting a copy of this
21883 function. */
21886 }
21896 else
21897 {
21902 }
21904 /* Mark D as instantiated so that recursive calls to
21905 instantiate_decl do not try to instantiate it again. */
21908 /* Regenerate the declaration in case the template has been modified
21909 by a subsequent redeclaration. */
21912 /* We already set the file and line above. Reset them now in case
21913 they changed as a result of calling regenerate_decl_from_template. */
21917 {
21918 tree init;
21921 /* Clear out DECL_RTL; whatever was there before may not be right
21922 since we've reset the type of the declaration. */
21926 /* The initializer is placed in DECL_INITIAL by
21927 regenerate_decl_from_template so we don't need to
21928 push/pop_access_scope again here. Pull it out so that
21929 cp_finish_decl can process it. */
21934 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
21935 initializer. That function will defer actual emission until
21936 we have a chance to determine linkage. */
21939 /* Enter the scope of D so that access-checking works correctly. */
21952 }
21956 {
21958 tree subst_decl;
21959 tree tmpl_parm;
21960 tree spec_parm;
21963 /* Save away the current list, in case we are instantiating one
21964 template from within the body of another. */
21967 /* Set up the list of local specializations. */
21970 /* Set up context. */
21974 else
21977 /* Some typedefs referenced from within the template code need to be
21978 access checked at template instantiation time, i.e now. These
21979 types were added to the template at parsing time. Let's get those
21980 and perform the access checks then. */
21982 gen_args);
21984 /* Create substitution entries for the parameters. */
21989 {
21993 }
21995 {
21997 {
22000 }
22001 else
22002 {
22003 /* Register the (value) argument pack as a specialization of
22004 TMPL_PARM, then move on. */
22007 }
22008 }
22011 /* Substitute into the body of the function. */
22015 else
22016 {
22021 /* Set the current input_location to the end of the function
22022 so that finish_function knows where we are. */
22023 input_location
22026 /* Remember if we saw an infinite loop in the template. */
22027 current_function_infinite_loop
22029 }
22031 /* We don't need the local specializations any more. */
22035 /* Finish the function. */
22039 else
22040 {
22043 }
22047 }
22049 /* We're not deferring instantiation any more. */
22057 out:
22069 }
22071 /* Run through the list of templates that we wish we could
22072 instantiate, and instantiate any we can. RETRIES is the
22073 number of times we retry pending template instantiation. */
22075 void
22077 {
22081 /* Instantiating templates may trigger vtable generation. This in turn
22082 may require further template instantiations. We place a limit here
22083 to avoid infinite loop. */
22085 {
22089 "template instantiation depth exceeds maximum of %d"
22090 " instantiating %q+D, possibly from virtual table generation"
22094 /* Pretend that we defined it. */
22097 }
22099 do
22100 {
22105 {
22110 {
22111 tree fn;
22114 {
22118 fn;
22126 }
22129 }
22130 else
22131 {
22134 {
22135 instantiation
22141 }
22145 }
22148 /* If INSTANTIATION has been instantiated, then we don't
22149 need to consider it again in the future. */
22151 else
22152 {
22155 }
22158 }
22160 }
22164 }
22166 /* Substitute ARGVEC into T, which is a list of initializers for
22167 either base class or a non-static data member. The TREE_PURPOSEs
22168 are DECLs, and the TREE_VALUEs are the initializer values. Used by
22169 instantiate_decl. */
22171 static tree
22173 {
22177 {
22178 tree decl;
22179 tree init;
22185 {
22186 tree expr;
22187 tree arg;
22189 /* Expand the base class expansion type into separate base
22190 classes. */
22192 tf_warning_or_error,
22193 NULL_TREE);
22197 /* We'll be building separate TREE_LISTs of arguments for
22198 each base. */
22204 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
22205 expand each argument in the TREE_VALUE of t. */
22212 /* VOID_TYPE_NODE is used to indicate
22213 value-initialization. */
22214 {
22217 }
22218 else
22219 {
22220 /* Substitute parameter packs into each argument in the
22221 TREE_LIST. */
22224 {
22225 tree expanded_exprs;
22227 /* Expand the argument. */
22229 expanded_exprs
22231 tf_warning_or_error,
22232 NULL_TREE);
22236 /* Prepend each of the expanded expressions to the
22237 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
22239 {
22244 }
22245 }
22248 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
22249 since we built them backwards. */
22251 {
22254 }
22255 }
22256 }
22259 {
22261 {
22265 }
22266 else
22267 {
22268 tree tmp;
22283 /* If we had an initializer but it instantiated to nothing,
22284 value-initialize the object. This will only occur when
22285 the initializer was a pack expansion where the parameter
22286 packs used in that expansion were of length zero. */
22289 }
22292 {
22296 }
22297 }
22298 }
22300 }
22302 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
22304 static void
22306 {
22311 else
22313 }
22315 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
22316 is the instantiation (which should have been created with
22317 start_enum) and ARGS are the template arguments to use. */
22319 static void
22321 {
22322 tree e;
22328 {
22329 tree value;
22330 tree decl;
22333 /* Note that in a template enum, the TREE_VALUE is the
22334 CONST_DECL, not the corresponding INTEGER_CST. */
22339 /* Give this enumeration constant the correct access. */
22342 /* Actually build the enumerator itself. Here we're assuming that
22343 enumerators can't have dependent attributes. */
22346 }
22356 }
22358 /* DECL is a FUNCTION_DECL that is a template specialization. Return
22359 its type -- but without substituting the innermost set of template
22360 arguments. So, innermost set of template parameters will appear in
22361 the type. */
22363 tree
22365 {
22366 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
22368 }
22370 /* Return truthvalue if we're processing a template different from
22371 the last one involved in diagnostics. */
22372 bool
22374 {
22376 }
22378 /* Remember current template involved in diagnostics. */
22379 void
22381 {
22383 }
22387 {
22389 }
22391 /* Return TRUE if current_function_decl is being instantiated, false
22392 otherwise. */
22394 bool
22396 {
22399 }
22401 /* [temp.param] Check that template non-type parm TYPE is of an allowable
22402 type. Return zero for ok, nonzero for disallowed. Issue error and
22403 warning messages under control of COMPLAIN. */
22405 static int
22407 {
22422 /* A bound template template parm could later be instantiated to have a valid
22423 nontype parm type via an alias template. */
22429 {
22432 else
22434 type);
22435 }
22437 }
22439 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
22440 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
22442 static bool
22444 {
22445 tree scope;
22447 /* [temp.dep.type]
22449 A type is dependent if it is:
22451 -- a template parameter. Template template parameters are types
22452 for us (since TYPE_P holds true for them) so we handle
22453 them here. */
22457 /* -- a qualified-id with a nested-name-specifier which contains a
22458 class-name that names a dependent type or whose unqualified-id
22459 names a dependent type. */
22463 /* An alias template specialization can be dependent even if the
22464 resulting type is not. */
22468 /* -- a cv-qualified type where the cv-unqualified type is
22469 dependent.
22470 No code is necessary for this bullet; the code below handles
22471 cv-qualified types, and we don't want to strip aliases with
22472 TYPE_MAIN_VARIANT because of DR 1558. */
22473 /* -- a compound type constructed from any dependent type. */
22483 {
22484 tree arg_type;
22489 arg_type;
22494 }
22495 /* -- an array type constructed from any dependent type or whose
22496 size is specified by a constant expression that is
22497 value-dependent.
22499 We checked for type- and value-dependence of the bounds in
22500 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
22502 {
22507 }
22509 /* -- a template-id in which either the template name is a template
22510 parameter ... */
22513 /* ... or any of the template arguments is a dependent type or
22514 an expression that is type-dependent or value-dependent. */
22516 && (any_dependent_template_arguments_p
22520 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
22521 dependent; if the argument of the `typeof' expression is not
22522 type-dependent, then it should already been have resolved. */
22528 /* A template argument pack is dependent if any of its packed
22529 arguments are. */
22531 {
22537 }
22539 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
22540 be template parameters. */
22544 /* The standard does not specifically mention types that are local
22545 to template functions or local classes, but they should be
22546 considered dependent too. For example:
22548 template <int I> void f() {
22549 enum E { a = I };
22550 S<sizeof (E)> s;
22551 }
22553 The size of `E' cannot be known until the value of `I' has been
22554 determined. Therefore, `E' must be considered dependent. */
22558 /* Don't use type_dependent_expression_p here, as it can lead
22559 to infinite recursion trying to determine whether a lambda
22560 nested in a lambda is dependent (c++/47687). */
22564 && (any_dependent_template_arguments_p
22568 /* Other types are non-dependent. */
22570 }
22572 /* Returns TRUE if TYPE is dependent, in the sense of
22573 [temp.dep.type]. Note that a NULL type is considered dependent. */
22575 bool
22577 {
22578 /* If there are no template parameters in scope, then there can't be
22579 any dependent types. */
22581 {
22582 /* If we are not processing a template, then nobody should be
22583 providing us with a dependent type. */
22587 }
22589 /* If the type is NULL, we have not computed a type for the entity
22590 in question; in that case, the type is dependent. */
22594 /* Erroneous types can be considered non-dependent. */
22598 /* If we have not already computed the appropriate value for TYPE,
22599 do so now. */
22601 {
22604 }
22607 }
22609 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
22610 lookup. In other words, a dependent type that is not the current
22611 instantiation. */
22613 bool
22615 {
22618 }
22620 /* T is a SCOPE_REF; return whether we need to consider it
22621 instantiation-dependent so that we can check access at instantiation
22622 time even though we know which member it resolves to. */
22624 static bool
22626 {
22632 else
22634 }
22636 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
22637 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
22638 expression. */
22640 /* Note that this predicate is not appropriate for general expressions;
22641 only constant expressions (that satisfy potential_constant_expression)
22642 can be tested for value dependence. */
22644 bool
22646 {
22650 /* A name declared with a dependent type. */
22655 {
22657 /* A name that has not been looked up -- must be dependent. */
22661 /* A non-type template parm. */
22665 /* A non-type template parm. */
22671 /* A constant with literal type and is initialized
22672 with an expression that is value-dependent.
22674 Note that a non-dependent parenthesized initializer will have
22675 already been replaced with its constant value, so if we see
22676 a TREE_LIST it must be dependent. */
22680 /* cp_finish_decl doesn't fold reference initializers. */
22692 /* These expressions are value-dependent if the type to which
22693 the cast occurs is dependent or the expression being casted
22694 is value-dependent. */
22695 {
22701 /* A functional cast has a list of operands. */
22704 {
22705 /* If there are no operands, it must be an expression such
22706 as "int()". This should not happen for aggregate types
22707 because it would form non-constant expressions. */
22712 }
22718 }
22723 /* FALLTHRU */
22726 /* A `sizeof' expression is value-dependent if the operand is
22727 type-dependent or is a pack expansion. */
22736 /* An 'encode' expression is value-dependent if the operand is
22737 type-dependent. */
22746 /* All instantiation-dependent expressions should also be considered
22747 value-dependent. */
22755 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
22756 is value-dependent. */
22757 {
22766 }
22769 {
22773 }
22784 {
22788 }
22791 /* Treat all requires-expressions as value-dependent so
22792 we don't try to fold them. */
22799 {
22806 {
22808 /* In a call to a constexpr member function, look through the
22809 implicit ADDR_EXPR on the object argument so that it doesn't
22810 cause the call to be considered value-dependent. We also
22811 look through it in potential_constant_expression. */
22818 }
22820 }
22823 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
22824 type-dependent. */
22829 {
22831 tree val;
22838 }
22841 /* Treat a GNU statement expression as dependent to avoid crashing
22842 under instantiate_non_dependent_expr; it can't be constant. */
22846 /* A constant expression is value-dependent if any subexpression is
22847 value-dependent. */
22849 {
22856 {
22860 {
22863 /* In some cases, some of the operands may be missing.l
22864 (For example, in the case of PREDECREMENT_EXPR, the
22865 amount to increment by may be missing.) That doesn't
22866 make the expression dependent. */
22869 }
22870 }
22874 }
22876 }
22878 /* The expression is not value-dependent. */
22880 }
22882 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
22883 [temp.dep.expr]. Note that an expression with no type is
22884 considered dependent. Other parts of the compiler arrange for an
22885 expression with type-dependent subexpressions to have no type, so
22886 this function doesn't have to be fully recursive. */
22888 bool
22890 {
22897 /* An unresolved name is always dependent. */
22903 /* A fold expression is type-dependent. */
22910 /* Some expression forms are never type-dependent. */
22924 /* The types of these expressions depends only on the type to which
22925 the cast occurs. */
22934 /* The types of these expressions depends only on the type created
22935 by the expression. */
22938 {
22939 /* For NEW_EXPR tree nodes created inside a template, either
22940 the object type itself or a TREE_LIST may appear as the
22941 operand 1. */
22944 /* This is an array type. We need to check array dimensions
22945 as well. */
22947 || value_dependent_expression_p
22949 else
22951 }
22954 {
22958 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
22959 contains an identifier associated by name lookup with one or more
22960 declarations declared with a dependent type, or...a
22961 nested-name-specifier or qualified-id that names a member of an
22962 unknown specialization. */
22965 }
22967 /* A function template specialization is type-dependent if it has any
22968 dependent template arguments. */
22982 {
22983 tree elt;
22987 {
22990 }
22992 }
22994 /* A static data member of the current instantiation with incomplete
22995 array type is type-dependent, as the definition and specializations
22996 can have different bounds. */
23003 /* An array of unknown bound depending on a variadic parameter, eg:
23005 template<typename... Args>
23006 void foo (Args... args)
23007 {
23008 int arr[] = { args... };
23009 }
23011 template<int... vals>
23012 void bar ()
23013 {
23014 int arr[] = { vals... };
23015 }
23017 If the array has no length and has an initializer, it must be that
23018 we couldn't determine its length in cp_complete_array_type because
23019 it is dependent. */
23026 /* A variable template specialization is type-dependent if it has any
23027 dependent template arguments. */
23034 /* Always dependent, on the number of arguments if nothing else. */
23039 {
23044 {
23050 }
23051 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
23056 {
23061 }
23064 {
23071 }
23077 {
23081 }
23083 }
23088 }
23090 /* walk_tree callback function for instantiation_dependent_expression_p,
23091 below. Returns non-zero if a dependent subexpression is found. */
23093 static tree
23096 {
23098 {
23099 /* We don't have to worry about decltype currently because decltype
23100 of an instantiation-dependent expr is a dependent type. This
23101 might change depending on the resolution of DR 1172. */
23104 }
23107 {
23108 /* Don't treat an argument list as dependent just because it has no
23109 TREE_TYPE. */
23117 /* Handle expressions with type operands. */
23122 {
23127 {
23130 else
23131 {
23134 }
23135 }
23137 }
23141 /* In a template, finish_class_member_access_expr creates a
23142 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
23143 type-dependent, so that we can check access control at
23144 instantiation time (PR 42277). See also Core issue 1273. */
23151 else
23154 /* Treat statement-expressions as dependent. */
23158 /* Treat requires-expressions as dependent. */
23163 /* Treat calls to function concepts as dependent. */
23169 /* And variable concepts. */
23176 }
23180 else
23182 }
23184 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
23185 sense defined by the ABI:
23187 "An expression is instantiation-dependent if it is type-dependent
23188 or value-dependent, or it has a subexpression that is type-dependent
23189 or value-dependent."
23191 Except don't actually check value-dependence for unevaluated expressions,
23192 because in sizeof(i) we don't care about the value of i. Checking
23193 type-dependence will in turn check value-dependence of array bounds/template
23194 arguments as needed. */
23196 bool
23198 {
23199 tree result;
23210 }
23212 /* As above, but also check value-dependence of the expression as a whole. */
23214 bool
23216 {
23219 }
23221 /* Like type_dependent_expression_p, but it also works while not processing
23222 a template definition, i.e. during substitution or mangling. */
23224 bool
23226 {
23232 }
23234 /* Returns TRUE if ARGS contains a type-dependent expression. */
23236 bool
23238 {
23240 tree arg;
23243 {
23246 }
23248 }
23250 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
23251 expressions) contains any type-dependent expressions. */
23253 bool
23255 {
23261 }
23263 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
23264 expressions) contains any value-dependent expressions. */
23266 bool
23268 {
23274 }
23276 /* Returns TRUE if the ARG (a template argument) is dependent. */
23278 bool
23280 {
23284 /* Assume a template argument that was wrongly written by the user
23285 is dependent. This is consistent with what
23286 any_dependent_template_arguments_p [that calls this function]
23287 does. */
23298 {
23302 {
23305 }
23308 }
23311 else
23314 }
23316 /* Returns true if ARGS (a collection of template arguments) contains
23317 any types that require structural equality testing. */
23319 bool
23321 {
23331 {
23334 {
23340 {
23341 /* Look inside the argument pack. */
23344 }
23347 {
23360 }
23361 }
23362 }
23365 }
23367 /* Returns true if ARGS (a collection of template arguments) contains
23368 any dependent arguments. */
23370 bool
23372 {
23382 {
23387 }
23390 }
23392 /* Returns TRUE if the template TMPL is dependent. */
23394 bool
23396 {
23398 {
23400 {
23404 }
23406 }
23408 /* Template template parameters are dependent. */
23412 /* So are names that have not been looked up. */
23415 /* So are member templates of dependent classes. */
23419 }
23421 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
23423 bool
23425 {
23428 }
23430 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
23431 are dependent. */
23433 bool
23435 {
23442 {
23464 {
23468 }
23472 {
23476 {
23481 }
23482 }
23483 }
23486 }
23488 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
23489 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
23490 no such TYPE can be found. Note that this function peers inside
23491 uninstantiated templates and therefore should be used only in
23492 extremely limited situations. ONLY_CURRENT_P restricts this
23493 peering to the currently open classes hierarchy (which is required
23494 when comparing types). */
23496 tree
23498 {
23499 tree scope;
23500 tree name;
23501 tree decl;
23503 tree pushed_scope;
23504 tree result;
23509 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
23510 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
23511 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
23512 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
23513 identifier of the TYPENAME_TYPE anymore.
23514 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
23515 TYPENAME_TYPE instead, we avoid messing up with a possible
23516 typedef variant case. */
23519 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
23520 it first before we can figure out what NAME refers to. */
23522 {
23524 /* Given a class template A with a dependent base with nested type C,
23525 typedef typename A::C::C C will land us here, as trying to resolve
23526 the initial A::C leads to the local C typedef, which leads back to
23527 A::C::C. So we break the recursion now. */
23529 else
23531 }
23532 /* If we don't know what SCOPE refers to, then we cannot resolve the
23533 TYPENAME_TYPE. */
23536 /* If the SCOPE is a template type parameter, we have no way of
23537 resolving the name. */
23540 /* If the SCOPE is not the current instantiation, there's no reason
23541 to look inside it. */
23544 /* If this is a typedef, we don't want to look inside (c++/11987). */
23547 /* If SCOPE isn't the template itself, it will not have a valid
23548 TYPE_FIELDS list. */
23551 /* scope is either the template itself or a compatible instantiation
23552 like X<T>, so look up the name in the original template. */
23554 else
23555 /* scope is a partial instantiation, so we can't do the lookup or we
23556 will lose the template arguments. */
23558 /* Enter the SCOPE so that name lookup will be resolved as if we
23559 were in the class definition. In particular, SCOPE will no
23560 longer be considered a dependent type. */
23562 /* Look up the declaration. */
23564 tf_warning_or_error);
23568 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
23569 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
23574 {
23578 }
23581 {
23582 tree tmpl;
23583 tree args;
23584 /* Obtain the template and the arguments. */
23587 /* Instantiate the template. */
23593 }
23595 /* Leave the SCOPE. */
23599 /* If we failed to resolve it, return the original typename. */
23603 /* If lookup found a typename type, resolve that too. */
23605 {
23606 /* Ill-formed programs can cause infinite recursion here, so we
23607 must catch that. */
23611 }
23613 /* Qualify the resulting type. */
23619 }
23621 /* EXPR is an expression which is not type-dependent. Return a proxy
23622 for EXPR that can be used to compute the types of larger
23623 expressions containing EXPR. */
23625 tree
23627 {
23628 tree inner_expr;
23630 /* When checking, try to get a constant value for all non-dependent
23631 expressions in order to expose bugs in *_dependent_expression_p
23632 and constexpr. This can affect code generation, see PR70704, so
23633 only do this for -fchecking=2. */
23636 /* Don't do this during nsdmi parsing as it can lead to
23637 unexpected recursive instantiations. */
23641 /* Preserve OVERLOADs; the functions must be available to resolve
23642 types. */
23653 /* There is no need to return a proxy for a variable. */
23656 /* Preserve string constants; conversions from string constants to
23657 "char *" are allowed, even though normally a "const char *"
23658 cannot be used to initialize a "char *". */
23661 /* Preserve void and arithmetic constants, as an optimization -- there is no
23662 reason to create a new node. */
23667 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
23668 There is at least one place where we want to know that a
23669 particular expression is a throw-expression: when checking a ?:
23670 expression, there are special rules if the second or third
23671 argument is a throw-expression. */
23675 /* Don't wrap an initializer list, we need to be able to look inside. */
23679 /* Don't wrap a dummy object, we need to be able to test for it. */
23698 /* If the type is unknown, it can't really be non-dependent */
23701 /* Otherwise, build a NON_DEPENDENT_EXPR. */
23703 }
23705 /* ARGS is a vector of expressions as arguments to a function call.
23706 Replace the arguments with equivalent non-dependent expressions.
23707 This modifies ARGS in place. */
23709 void
23711 {
23713 tree arg;
23716 {
23720 }
23721 }
23723 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
23724 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
23725 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
23727 static tree
23729 {
23743 }
23745 tree
23747 {
23749 }
23751 tree
23753 {
23755 }
23757 /* Make a "constrained auto" type-specifier. This is an
23758 auto type with constraints that must be associated after
23759 deduction. The constraint is formed from the given
23760 CONC and its optional sequence of arguments, which are
23761 non-null if written as partial-concept-id. */
23763 tree
23765 {
23768 /* Build the constraint. */
23770 tree expr;
23773 else
23779 /* Our canonical type depends on the constraint. */
23782 /* Attach the constraint to the type declaration. */
23785 }
23787 /* Given type ARG, return std::initializer_list<ARG>. */
23789 static tree
23791 {
23792 tree std_init_list = namespace_binding
23794 tree argvec;
23796 {
23800 }
23805 }
23807 /* Replace auto in TYPE with std::initializer_list<auto>. */
23809 static tree
23811 {
23818 }
23820 /* Hash traits for hashing possibly constrained 'auto'
23821 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
23824 {
23827 };
23829 /* Hash the 'auto' T. */
23831 inline hashval_t
23833 {
23835 /* Matching constrained-type-specifiers denote the same template
23836 parameter, so hash the constraint. */
23838 else
23839 /* But unconstrained autos are all separate, so just hash the pointer. */
23841 }
23843 /* Compare two 'auto's. */
23847 {
23854 /* Two unconstrained autos are distinct. */
23859 }
23861 /* for_each_template_parm callback for extract_autos: if t is a (possibly
23862 constrained) auto, add it to the vector. */
23864 static int
23866 {
23869 {
23870 /* All the autos were built with index 0; fix that up now. */
23874 /* If this is a repeated constrained-type-specifier, use the index we
23875 chose before. */
23877 else
23878 {
23879 /* Otherwise this is new, so use the current count. */
23882 }
23884 }
23886 /* Always keep walking. */
23888 }
23890 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
23891 says they can appear anywhere in the type. */
23893 static tree
23895 {
23904 {
23909 }
23912 }
23914 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23915 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
23917 tree
23919 {
23921 tf_warning_or_error,
23922 adc_unspecified);
23923 }
23925 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23926 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
23927 The CONTEXT determines the context in which auto deduction is performed
23928 and is used to control error diagnostics. */
23930 tree
23933 {
23934 tree targs;
23940 /* Defining a subset of type-dependent expressions that we can deduce
23941 from ahead of time isn't worth the trouble. */
23944 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
23945 with either a new invented type template parameter U or, if the
23946 initializer is a braced-init-list (8.5.4), with
23947 std::initializer_list<U>. */
23949 {
23954 else
23955 {
23957 {
23961 "for deduction to %<std::initializer_list%>, use copy-"
23963 }
23965 }
23966 }
23974 {
23981 {
23985 }
23986 }
23987 else
23988 {
23990 tree tparms;
23994 else
23995 {
23999 }
24006 {
24008 /* Try again at instantiation time. */
24012 /* If type is error_mark_node a diagnostic must have been
24013 emitted by now. Also, having a mention to '<type error>'
24014 in the diagnostic is not really useful to the user. */
24015 {
24019 else
24024 }
24026 }
24027 }
24029 /* Check any placeholder constraints against the deduced type. */
24032 {
24033 /* Use the deduced type to check the associated constraints. */
24035 {
24037 {
24039 {
24055 }
24057 }
24059 }
24060 }
24065 }
24067 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
24068 result. */
24070 tree
24072 {
24074 {
24080 /* In an abbreviated function template we didn't know we were dealing
24081 with a function template when we saw the auto return type, so update
24082 it to have the correct level. */
24084 }
24086 }
24088 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
24089 'decltype(auto)'. */
24091 bool
24093 {
24098 else
24100 }
24102 /* for_each_template_parm callback for type_uses_auto. */
24104 int
24106 {
24108 }
24110 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
24111 a use of `auto'. Returns NULL_TREE otherwise. */
24113 tree
24115 {
24119 {
24120 /* The Concepts TS allows multiple autos in one type-specifier; just
24121 return the first one we find, do_auto_deduction will collect all of
24122 them. */
24126 else
24128 }
24129 else
24131 }
24133 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
24134 'decltype(auto)' or a concept. */
24136 bool
24138 {
24140 }
24142 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
24143 a concept identifier) iff TYPE contains a use of a generic type. Returns
24144 NULL_TREE otherwise. */
24146 tree
24148 {
24150 }
24153 /* For a given template T, return the vector of typedefs referenced
24154 in T for which access check is needed at T instantiation time.
24155 T is either a FUNCTION_DECL or a RECORD_TYPE.
24156 Those typedefs were added to T by the function
24157 append_type_to_template_for_access_check. */
24161 {
24162 tree ti;
24173 {
24178 }
24181 }
24183 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
24184 tied to T. That list of typedefs will be access checked at
24185 T instantiation time.
24186 T is either a FUNCTION_DECL or a RECORD_TYPE.
24187 TYPE_DECL is a TYPE_DECL node representing a typedef.
24188 SCOPE is the scope through which TYPE_DECL is accessed.
24189 LOCATION is the location of the usage point of TYPE_DECL.
24191 This function is a subroutine of
24192 append_type_to_template_for_access_check. */
24194 static void
24196 tree type_decl,
24197 tree scope,
24198 location_t location)
24199 {
24200 qualified_typedef_usage_t typedef_usage;
24201 tree ti;
24208 && type_decl
24222 }
24224 /* Append TYPE_DECL to the template TEMPL.
24225 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
24226 At TEMPL instanciation time, TYPE_DECL will be checked to see
24227 if it can be accessed through SCOPE.
24228 LOCATION is the location of the usage point of TYPE_DECL.
24230 e.g. consider the following code snippet:
24232 class C
24233 {
24234 typedef int myint;
24235 };
24237 template<class U> struct S
24238 {
24239 C::myint mi; // <-- usage point of the typedef C::myint
24240 };
24242 S<char> s;
24244 At S<char> instantiation time, we need to check the access of C::myint
24245 In other words, we need to check the access of the myint typedef through
24246 the C scope. For that purpose, this function will add the myint typedef
24247 and the scope C through which its being accessed to a list of typedefs
24248 tied to the template S. That list will be walked at template instantiation
24249 time and access check performed on each typedefs it contains.
24250 Note that this particular code snippet should yield an error because
24251 myint is private to C. */
24253 void
24255 tree type_decl,
24256 tree scope,
24257 location_t location)
24258 {
24264 /* Make sure we don't append the type to the template twice. */
24271 }
24273 /* Convert the generic type parameters in PARM that match the types given in the
24274 range [START_IDX, END_IDX) from the current_template_parms into generic type
24275 packs. */
24277 tree
24279 {
24290 {
24291 /* Create a distinct parameter pack type from the current parm and add it
24292 to the replacement args to tsubst below into the generic function
24293 parameter. */
24308 }
24314 /* If there are more levels then build up the replacement with the outer
24315 template parms. */
24319 replacement);
24322 }
24324 /* Entries in the decl_constraint hash table. */
24326 {
24327 tree decl;
24328 tree ci;
24329 };
24331 /* Hashing function and equality for constraint entries. */
24333 {
24335 {
24337 }
24340 {
24342 }
24343 };
24345 /* A mapping from declarations to constraint information. Note that
24346 both templates and their underlying declarations are mapped to the
24347 same constraint information.
24349 FIXME: This is defined in pt.c because garbage collection
24350 code is not being generated for constraint.cc. */
24354 /* Returns true iff cinfo contains a valid set of constraints.
24355 This is the case when the associated requirements have been
24356 successfully decomposed into lists of atomic constraints.
24357 That is, when the saved assumptions are not error_mark_node. */
24359 bool
24361 {
24364 }
24366 /* Returns the template constraints of declaration T. If T is not
24367 constrained, return NULL_TREE. Note that T must be non-null. */
24369 tree
24371 {
24379 else
24381 }
24383 /* Associate the given constraint information CI with the declaration
24384 T. If T is a template, then the constraints are associated with
24385 its underlying declaration. Don't build associations if CI is
24386 NULL_TREE. */
24388 void
24390 {
24402 }
24404 /* Remove the associated constraints of the declaration T. */
24406 void
24408 {
24417 }
24419 /* Set up the hash table for constraint association. */
24421 void
24423 {
24425 }
24427 /* Set up the hash tables for template instantiations. */
24429 void
24431 {
24434 }
24436 /* Print stats about the template hash tables for -fstats. */
24438 void
24440 {
24449 }