| blob | bc03f0e818e954ac42862bf0035139bade3d0849 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2018 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". */
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
50 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
51 instantiations have been deferred, either because their definitions
52 were not yet available, or because we were putting off doing the work. */
56 };
71 /* Live only within one (recursive) call to tsubst_expr. We use
72 this to pass the statement expression node from the STMT_EXPR
73 to the EXPR_STMT that is its result. */
76 // -------------------------------------------------------------------------- //
77 // Local Specialization Stack
78 //
79 // Implementation of the RAII helper for creating new local
80 // specializations.
83 {
86 else
88 }
91 {
94 }
96 /* True if we've recursed into fn_type_unification too many times. */
100 {
101 tree tmpl;
102 tree args;
103 tree spec;
104 };
107 {
110 };
116 /* Contains canonical template parameter types. The vector is indexed by
117 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
118 TREE_LIST, whose TREE_VALUEs contain the canonical template
119 parameters of various types and levels. */
122 #define UNIFY_ALLOW_NONE 0
123 #define UNIFY_ALLOW_MORE_CV_QUAL 1
124 #define UNIFY_ALLOW_LESS_CV_QUAL 2
125 #define UNIFY_ALLOW_DERIVED 4
126 #define UNIFY_ALLOW_INTEGER 8
127 #define UNIFY_ALLOW_OUTER_LEVEL 16
128 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
129 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
132 tbr_incomplete_type,
133 tbr_ambiguous_baseclass,
134 tbr_success
135 };
158 tree);
215 location_t);
227 /* Make the current scope suitable for access checking when we are
228 processing T. T can be FUNCTION_DECL for instantiated function
229 template, VAR_DECL for static member variable, or TYPE_DECL for
230 alias template (needed by instantiate_decl). */
232 static void
234 {
242 else
246 {
247 saved_access_scope = tree_cons
250 }
251 }
253 /* Restore the scope set up by push_access_scope. T is the node we
254 are processing. */
256 static void
258 {
260 {
263 }
267 else
269 }
271 /* Do any processing required when DECL (a member template
272 declaration) is finished. Returns the TEMPLATE_DECL corresponding
273 to DECL, unless it is a specialization, in which case the DECL
274 itself is returned. */
276 tree
278 {
285 {
286 tree type;
294 {
298 }
300 }
304 {
306 {
309 }
310 else
312 }
313 else
317 }
319 /* Create a template info node. */
321 tree
323 {
328 }
330 /* Return the template info node corresponding to T, whatever T is. */
332 tree
334 {
356 }
358 /* Returns the template nesting level of the indicated class TYPE.
360 For example, in:
361 template <class T>
362 struct A
363 {
364 template <class U>
365 struct B {};
366 };
368 A<T>::B<U> has depth two, while A<T> has depth one.
369 Both A<T>::B<int> and A<int>::B<U> have depth one, if
370 they are instantiations, not specializations.
372 This function is guaranteed to return 0 if passed NULL_TREE so
373 that, for example, `template_class_depth (current_class_type)' is
374 always safe. */
376 int
378 {
382 {
393 else
395 }
398 }
400 /* Subroutine of maybe_begin_member_template_processing.
401 Returns true if processing DECL needs us to push template parms. */
403 static bool
405 {
411 }
413 /* Subroutine of maybe_begin_member_template_processing.
414 Push the template parms in PARMS, starting from LEVELS steps into the
415 chain, and ending at the beginning, since template parms are listed
416 innermost first. */
418 static void
420 {
428 current_template_parms
434 NULL);
436 {
445 {
452 /* Push the CONST_DECL. */
458 }
459 }
460 }
462 /* Restore the template parameter context for a member template, a
463 friend template defined in a class definition, or a non-template
464 member of template class. */
466 void
468 {
469 tree parms;
474 {
477 /* Disregard full specializations (c++/60999). */
480 }
483 {
488 {
491 }
494 }
496 /* Remember how many levels of template parameters we pushed so that
497 we can pop them later. */
499 }
501 /* Undo the effects of maybe_begin_member_template_processing. */
503 void
505 {
514 {
518 }
519 }
521 /* Return a new template argument vector which contains all of ARGS,
522 but has as its innermost set of arguments the EXTRA_ARGS. */
524 static tree
526 {
527 tree new_args;
545 }
547 /* Like add_to_template_args, but only the outermost ARGS are added to
548 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
549 (EXTRA_ARGS) levels are added. This function is used to combine
550 the template arguments from a partial instantiation with the
551 template arguments used to attain the full instantiation from the
552 partial instantiation. */
554 static tree
556 {
557 tree new_args;
559 /* If there are more levels of EXTRA_ARGS than there are ARGS,
560 something very fishy is going on. */
563 /* If *all* the new arguments will be the EXTRA_ARGS, just return
564 them. */
568 /* For the moment, we make ARGS look like it contains fewer levels. */
573 /* Now, we restore ARGS to its full dimensions. */
577 }
579 /* Return the N levels of innermost template arguments from the ARGS. */
581 tree
583 {
584 tree new_args;
590 /* If N is 1, just return the innermost set of template arguments. */
594 /* If we're not removing anything, just return the arguments we were
595 given. */
601 /* Make a new set of arguments, not containing the outer arguments. */
608 }
610 /* The inverse of get_innermost_template_args: Return all but the innermost
611 EXTRA_LEVELS levels of template arguments from the ARGS. */
613 static tree
615 {
616 tree new_args;
622 /* If N is 1, just return the outermost set of template arguments. */
626 /* If we're not removing anything, just return the arguments we were
627 given. */
632 /* Make a new set of arguments, not containing the inner arguments. */
639 }
641 /* We've got a template header coming up; push to a new level for storing
642 the parms. */
644 void
646 {
647 /* We use a non-tag-transparent scope here, which causes pushtag to
648 put tags in this scope, rather than in the enclosing class or
649 namespace scope. This is the right thing, since we want
650 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
651 global template class, push_template_decl handles putting the
652 TEMPLATE_DECL into top-level scope. For a nested template class,
653 e.g.:
655 template <class T> struct S1 {
656 template <class T> struct S2 {};
657 };
659 pushtag contains special code to insert the TEMPLATE_DECL for S2
660 at the right scope. */
666 /* Add a dummy parameter level while we process the parameter list. */
667 current_template_parms
670 current_template_parms);
671 }
673 /* This routine is called when a specialization is declared. If it is
674 invalid to declare a specialization here, an error is reported and
675 false is returned, otherwise this routine will return true. */
677 static bool
679 {
682 /* [temp.expl.spec]
684 An explicit specialization shall be declared in the namespace of
685 which the template is a member, or, for member templates, in the
686 namespace of which the enclosing class or enclosing class
687 template is a member. An explicit specialization of a member
688 function, member class or static data member of a class template
689 shall be declared in the namespace of which the class template
690 is a member. */
692 {
695 }
697 /* [temp.expl.spec]
699 In an explicit specialization declaration for a member of a class
700 template or a member template that appears in namespace scope,
701 the member template and some of its enclosing class templates may
702 remain unspecialized, except that the declaration shall not
703 explicitly specialize a class member template if its enclosing
704 class templates are not explicitly specialized as well. */
706 {
709 }
712 }
714 /* We've just seen template <>. */
716 bool
718 {
722 }
724 /* Called at then end of processing a declaration preceded by
725 template<>. */
727 void
729 {
732 }
734 /* Any template <>'s that we have seen thus far are not referring to a
735 function specialization. */
737 void
739 {
742 }
744 /* We've just seen a template header. If SPECIALIZATION is nonzero,
745 it was of the form template <>. */
747 static void
749 {
751 template_header_count++;
752 }
754 /* We're beginning an explicit instantiation. */
756 void
758 {
761 }
764 void
766 {
769 }
771 /* An explicit specialization or partial specialization of TMPL is being
772 declared. Check that the namespace in which the specialization is
773 occurring is permissible. Returns false iff it is invalid to
774 specialize TMPL in the current namespace. */
776 static bool
778 {
781 /* [tmpl.expl.spec]
783 An explicit specialization shall be declared in a namespace enclosing the
784 specialized template. An explicit specialization whose declarator-id is
785 not qualified shall be declared in the nearest enclosing namespace of the
786 template, or, if the namespace is inline (7.3.1), any namespace from its
787 enclosing namespace set. */
790 {
793 }
796 /* Same or enclosing namespace. */
798 else
799 {
805 }
806 }
808 /* SPEC is an explicit instantiation. Check that it is valid to
809 perform this explicit instantiation in the current namespace. */
811 static void
813 {
814 tree ns;
816 /* DR 275: An explicit instantiation shall appear in an enclosing
817 namespace of its template. */
823 }
825 // Returns the type of a template specialization only if that
826 // specialization needs to be defined. Otherwise (e.g., if the type has
827 // already been defined), the function returns NULL_TREE.
828 static tree
830 {
831 // An implicit instantiation of an incomplete type implies
832 // the definition of a new class template.
833 //
834 // template<typename T>
835 // struct S;
836 //
837 // template<typename T>
838 // struct S<T*>;
839 //
840 // Here, S<T*> is an implicit instantiation of S whose type
841 // is incomplete.
845 // It can also be the case that TYPE is a completed specialization.
846 // Continuing the previous example, suppose we also declare:
847 //
848 // template<typename T>
849 // requires Integral<T>
850 // struct S<T*>;
851 //
852 // Here, S<T*> refers to the specialization S<T*> defined
853 // above. However, we need to differentiate definitions because
854 // we intend to define a new partial specialization. In this case,
855 // we rely on the fact that the constraints are different for
856 // this declaration than that above.
857 //
858 // Note that we also get here for injected class names and
859 // late-parsed template definitions. We must ensure that we
860 // do not create new type declarations for those cases.
862 {
866 // If there are no template parameters, this cannot be a new
867 // partial template specializtion?
871 // The injected-class-name is not a new partial specialization.
875 // If the constraints are not the same as those of the primary
876 // then, we can probably create a new specialization.
880 {
884 }
886 // Also, if there's a pre-existing specialization with matching
887 // constraints, then this also isn't new.
890 {
898 }
900 // Create a new type node (and corresponding type decl)
901 // for the newly declared specialization.
906 /* We only need a separate type node for storing the definition of this
907 partial specialization; uses of S<T*> are unconstrained, so all are
908 equivalent. So keep TYPE_CANONICAL the same. */
911 // Build the corresponding type decl.
917 }
920 }
922 /* The TYPE is being declared. If it is a template type, that means it
923 is a partial specialization. Do appropriate error-checking. */
925 tree
927 {
928 tree context;
933 /* A lambda that appears in specialization context is not itself a
934 specialization. */
939 {
943 }
948 {
954 else
957 }
959 {
960 /* This is for ordinary explicit specialization and partial
961 specialization of a template class such as:
963 template <> class C<int>;
965 or:
967 template <class T> class C<T*>;
969 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
972 {
979 {
984 }
985 }
991 /* Trying to define a specialization either without a template<> header
992 or in an inappropriate place. We've already given an error, so just
993 bail now so we don't actually define the specialization. */
995 }
1001 {
1002 /* This is for an explicit specialization of member class
1003 template according to [temp.expl.spec/18]:
1005 template <> template <class U> class C<int>::D;
1007 The context `C<int>' must be an implicit instantiation.
1008 Otherwise this is just a member class template declared
1009 earlier like:
1011 template <> class C<int> { template <class U> class D; };
1012 template <> template <class U> class C<int>::D;
1014 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1015 while in the second case, `C<int>::D' is a primary template
1016 and `C<T>::D' may not exist. */
1020 {
1021 tree t;
1026 {
1031 }
1033 /* Check for invalid specialization after instantiation:
1035 template <> template <> class C<int>::D<int>;
1036 template <> template <class U> class C<int>::D; */
1040 {
1044 {
1045 /* We already have a full specialization of this partial
1046 instantiation, or a full specialization has been
1047 looked up but not instantiated. Reassign it to the
1048 new member specialization template. */
1049 spec_entry elt;
1061 spec_entry **slot
1066 }
1067 else
1068 /* But if we've had an implicit instantiation, that's a
1069 problem ([temp.expl.spec]/6). */
1072 }
1074 /* Mark TYPE as a specialization. And as a result, we only
1075 have one level of template argument for the innermost
1076 class template. */
1081 }
1082 }
1084 {
1085 /* Someday C++0x may allow for enum template specialization. */
1090 else
1091 {
1094 }
1095 }
1098 }
1100 /* Returns nonzero if we can optimize the retrieval of specializations
1101 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1102 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1106 {
1109 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1110 parameter. */
1112 /* The optimized lookup depends on the fact that the
1113 template arguments for the member function template apply
1114 purely to the containing class, which is not true if the
1115 containing class is an explicit or partial
1116 specialization. */
1120 /* It is possible to have a template that is not a member
1121 template and is not a member of a template class:
1123 template <typename T>
1124 struct S { friend A::f(); };
1126 Here, the friend function is a template, but the context does
1127 not have template information. The optimized lookup relies
1128 on having ARGS be the template arguments for both the class
1129 and the function template. */
1131 }
1133 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1134 gone through coerce_template_parms by now. */
1136 static void
1138 {
1141 {
1144 {
1151 /* Allow typedefs on the type of a non-type argument, since a
1153 else
1155 }
1156 }
1158 }
1160 /* Retrieve the specialization (in the sense of [temp.spec] - a
1161 specialization is either an instantiation or an explicit
1162 specialization) of TMPL for the given template ARGS. If there is
1163 no such specialization, return NULL_TREE. The ARGS are a vector of
1164 arguments, or a vector of vectors of arguments, in the case of
1165 templates with more than one level of parameters.
1167 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1168 then we search for a partial specialization matching ARGS. This
1169 parameter is ignored if TMPL is not a class template.
1171 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1172 result is a NONTYPE_ARGUMENT_PACK. */
1174 static tree
1176 {
1186 /* There should be as many levels of arguments as there are
1187 levels of parameters. */
1196 /* Lambda functions in templates aren't instantiated normally, but through
1197 tsubst_lambda_expr. */
1202 {
1203 /* The template arguments actually apply to the containing
1204 class. Find the class specialization with those
1205 arguments. */
1207 tree class_specialization
1212 /* Find the instance of TMPL. */
1215 {
1218 /* using-declarations can add base methods to the method vec,
1219 and we don't want those here. */
1222 }
1224 }
1225 else
1226 {
1228 spec_entry elt;
1237 else
1245 }
1248 }
1250 /* Like retrieve_specialization, but for local declarations. */
1252 tree
1254 {
1260 }
1262 /* Returns nonzero iff DECL is a specialization of TMPL. */
1264 int
1266 {
1267 tree t;
1270 {
1276 }
1277 else
1278 {
1287 }
1290 }
1292 /* Returns nonzero iff DECL is a specialization of friend declaration
1293 FRIEND_DECL according to [temp.friend]. */
1295 bool
1297 {
1304 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1305 of a template class, we want to check if DECL is a specialization
1306 if this. */
1310 {
1311 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1314 }
1319 /* There is nothing to do if this is not a template friend. */
1326 /* [temp.friend/6]
1327 A member of a class template may be declared to be a friend of a
1328 non-template class. In this case, the corresponding member of
1329 every specialization of the class template is a friend of the
1330 class granting friendship.
1332 For example, given a template friend declaration
1334 template <class T> friend void A<T>::f();
1336 the member function below is considered a friend
1338 template <> struct A<int> {
1339 void f();
1340 };
1342 For this type of template friend, TEMPLATE_DEPTH below will be
1343 nonzero. To determine if DECL is a friend of FRIEND, we first
1344 check if the enclosing class is a specialization of another. */
1351 {
1352 /* Next, we check the members themselves. In order to handle
1353 a few tricky cases, such as when FRIEND_DECL's are
1355 template <class T> friend void A<T>::g(T t);
1356 template <class T> template <T t> friend void A<T>::h();
1358 and DECL's are
1360 void A<int>::g(int);
1361 template <int> void A<int>::h();
1363 we need to figure out ARGS, the template arguments from
1364 the context of DECL. This is required for template substitution
1365 of `T' in the function parameter of `g' and template parameter
1366 of `h' in the above examples. Here ARGS corresponds to `int'. */
1373 {
1375 {
1378 else
1380 current_depth++;
1381 }
1383 }
1386 {
1388 tree friend_type;
1389 tree decl_type;
1390 tree friend_args_type;
1391 tree decl_args_type;
1393 /* Make sure that both DECL and FRIEND_DECL are templates or
1394 non-templates. */
1400 {
1401 /* If both are templates, check template parameter list. */
1402 tree friend_parms
1407 friend_parms))
1411 }
1412 else
1420 /* Check if return types match. */
1424 /* Check if function parameter types match, ignoring the
1425 `this' parameter. */
1434 }
1435 else
1436 {
1437 /* DECL is a TYPE_DECL */
1441 /* Make sure that both DECL and FRIEND_DECL are templates or
1442 non-templates. */
1443 is_template
1450 {
1451 tree friend_parms;
1452 /* If both are templates, check the name of the two
1453 TEMPLATE_DECL's first because is_friend didn't. */
1458 /* Now check template parameter list. */
1459 friend_parms
1462 return comp_template_parms
1464 friend_parms);
1465 }
1466 else
1469 }
1470 }
1472 }
1474 /* Register the specialization SPEC as a specialization of TMPL with
1475 the indicated ARGS. IS_FRIEND indicates whether the specialization
1476 is actually just a friend declaration. Returns SPEC, or an
1477 equivalent prior declaration, if available.
1479 We also store instantiations of field packs in the hash table, even
1480 though they are not themselves templates, to make lookup easier. */
1482 static tree
1484 hashval_t hash)
1485 {
1486 tree fn;
1488 spec_entry elt;
1496 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1497 register it; we want the corresponding TEMPLATE_DECL instead.
1498 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1499 the more obvious `uses_template_parms (spec)' to avoid problems
1500 with default function arguments. In particular, given
1501 something like this:
1503 template <class T> void f(T t1, T t = T())
1505 the default argument expression is not substituted for in an
1506 instantiation unless and until it is actually needed. */
1510 /* We don't put these specializations in the hash table, but we might
1511 want to give an error about a mismatch. */
1513 else
1514 {
1522 slot =
1526 else
1528 }
1530 /* We can sometimes try to re-register a specialization that we've
1531 already got. In particular, regenerate_decl_from_template calls
1532 duplicate_decls which will update the specialization list. But,
1533 we'll still get called again here anyhow. It's more convenient
1534 to simply allow this than to try to prevent it. */
1538 {
1540 {
1543 {
1545 fn);
1547 }
1548 else
1549 {
1550 tree clone;
1551 /* This situation should occur only if the first
1552 specialization is an implicit instantiation, the
1553 second is an explicit specialization, and the
1554 implicit instantiation has not yet been used. That
1555 situation can occur if we have implicitly
1556 instantiated a member function and then specialized
1557 it later.
1559 We can also wind up here if a friend declaration that
1560 looked like an instantiation turns out to be a
1561 specialization:
1563 template <class T> void foo(T);
1564 class S { friend void foo<>(int) };
1565 template <> void foo(int);
1567 We transform the existing DECL in place so that any
1568 pointers to it become pointers to the updated
1569 declaration.
1571 If there was a definition for the template, but not
1572 for the specialization, we want this to look as if
1573 there were no definition, and vice versa. */
1576 /* The call to duplicate_decls will have applied
1577 [temp.expl.spec]:
1579 An explicit specialization of a function template
1580 is inline only if it is explicitly declared to be,
1581 and independently of whether its function template
1582 is.
1584 to the primary function; now copy the inline bits to
1585 the various clones. */
1587 {
1594 }
1598 }
1599 }
1601 {
1604 /* We've already complained in duplicate_decls. */
1608 /* Dup decl failed, but this is a new definition. Set the
1609 line number so any errors match this new
1610 definition. */
1614 }
1615 }
1619 /* A specialization must be declared in the same namespace as the
1620 template it is specializing. */
1626 {
1635 /* If TMPL is a forward declaration of a template function, keep a list
1636 of all specializations in case we need to reassign them to a friend
1637 template later in tsubst_friend_function.
1639 Also keep a list of all variable template instantiations so that
1640 process_partial_specialization can check whether a later partial
1641 specialization would have used it. */
1644 }
1647 }
1649 /* Returns true iff two spec_entry nodes are equivalent. */
1653 bool
1655 {
1662 /* tmpl could be a FIELD_DECL for a capture pack. */
1666 {
1667 /* Partial specializations of a variable template can be distinguished by
1668 constraints. */
1672 }
1676 }
1678 /* Returns a hash for a template TMPL and template arguments ARGS. */
1680 static hashval_t
1682 {
1685 }
1687 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1688 ignoring SPEC. */
1690 hashval_t
1692 {
1694 }
1696 /* Recursively calculate a hash value for a template argument ARG, for use
1697 in the hash tables of template specializations. */
1699 hashval_t
1701 {
1721 {
1729 {
1734 }
1756 {
1760 {
1763 }
1765 }
1769 {
1772 }
1783 val = iterative_hash_template_arg
1795 val);
1797 val);
1806 /* A lambda can't appear in a template arg, but don't crash on
1807 erroneous input. */
1819 /* Now hash operands as usual. */
1824 }
1827 {
1830 {
1831 // We want an alias specialization that survived strip_typedefs
1832 // to hash differently from its TYPE_CANONICAL, to avoid hash
1833 // collisions that compare as different in template_args_equal.
1834 // These could be dependent specializations that strip_typedefs
1835 // left alone, or untouched specializations because
1836 // coerce_template_parms returns the unconverted template
1837 // arguments if it sees incomplete argument packs.
1840 }
1843 val);
1846 /* Otherwise just compare the types during lookup. */
1855 {
1860 }
1861 }
1864 }
1866 /* Unregister the specialization SPEC as a specialization of TMPL.
1867 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1868 if the SPEC was listed as a specialization of TMPL.
1870 Note that SPEC has been ggc_freed, so we can't look inside it. */
1872 bool
1874 {
1876 spec_entry elt;
1884 {
1889 }
1892 }
1894 /* Like register_specialization, but for local declarations. We are
1895 registering SPEC, an instantiation of TMPL. */
1897 void
1899 {
1902 }
1904 /* TYPE is a class type. Returns true if TYPE is an explicitly
1905 specialized class. */
1907 bool
1909 {
1913 }
1915 /* Print the list of functions at FNS, going through all the overloads
1916 for each element of the list. Alternatively, FNS can not be a
1917 TREE_LIST, in which case it will be printed together with all the
1918 overloads.
1920 MORE and *STR should respectively be FALSE and NULL when the function
1921 is called from the outside. They are used internally on recursive
1922 calls. print_candidates manages the two parameters and leaves NULL
1923 in *STR when it ends. */
1925 static void
1927 {
1931 else
1933 {
1939 {
1942 else
1945 }
1947 }
1948 }
1950 /* Print the list of candidate FNS in an error message. FNS can also
1951 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1953 void
1955 {
1959 }
1961 /* Get a (possibly) constrained template declaration for the
1962 purpose of ordering candidates. */
1963 static tree
1965 {
1971 }
1973 /* Among candidates having the same signature, return the
1974 most constrained or NULL_TREE if there is no best candidate.
1975 If the signatures of candidates vary (e.g., template
1976 specialization vs. member function), then there can be no
1977 most constrained.
1979 Note that we don't compare constraints on the functions
1980 themselves, but rather those of their templates. */
1981 static tree
1983 {
1984 // Try to find the best candidate in a first pass.
1987 {
1994 }
1996 // Verify that the champ is better than previous candidates.
2001 }
2004 }
2007 /* Returns the template (one of the functions given by TEMPLATE_ID)
2008 which can be specialized to match the indicated DECL with the
2009 explicit template args given in TEMPLATE_ID. The DECL may be
2010 NULL_TREE if none is available. In that case, the functions in
2011 TEMPLATE_ID are non-members.
2013 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2014 specialization of a member template.
2016 The TEMPLATE_COUNT is the number of references to qualifying
2017 template classes that appeared in the name of the function. See
2018 check_explicit_specialization for a more accurate description.
2020 TSK indicates what kind of template declaration (if any) is being
2021 declared. TSK_TEMPLATE indicates that the declaration given by
2022 DECL, though a FUNCTION_DECL, has template parameters, and is
2023 therefore a template function.
2025 The template args (those explicitly specified and those deduced)
2026 are output in a newly created vector *TARGS_OUT.
2028 If it is impossible to determine the result, an error message is
2029 issued. The error_mark_node is returned to indicate failure. */
2031 static tree
2033 tree decl,
2037 tmpl_spec_kind tsk)
2038 {
2039 tree fns;
2040 tree targs;
2041 tree explicit_targs;
2044 /* A TREE_LIST of templates of which DECL may be a specialization.
2045 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2046 corresponding TREE_PURPOSE is the set of template arguments that,
2047 when used to instantiate the template, would produce a function
2048 with the signature of DECL. */
2058 /* We shouldn't be specializing a member template of an
2059 unspecialized class template; we already gave an error in
2060 check_specialization_scope, now avoid crashing. */
2063 {
2066 }
2074 /* Check for baselinks. */
2079 {
2082 }
2084 {
2087 }
2089 /* Count the number of template headers specified for this
2090 specialization. */
2100 {
2103 tf_warning_or_error,
2107 }
2109 {
2113 {
2114 tree decl_arg_types;
2115 tree fn_arg_types;
2116 tree insttype;
2118 /* In case of explicit specialization, we need to check if
2119 the number of template headers appearing in the specialization
2120 is correct. This is usually done in check_explicit_specialization,
2121 but the check done there cannot be exhaustive when specializing
2122 member functions. Consider the following code:
2124 template <> void A<int>::f(int);
2125 template <> template <> void A<int>::f(int);
2127 Assuming that A<int> is not itself an explicit specialization
2128 already, the first line specializes "f" which is a non-template
2129 member function, whilst the second line specializes "f" which
2130 is a template member function. So both lines are syntactically
2131 correct, and check_explicit_specialization does not reject
2132 them.
2134 Here, we can do better, as we are matching the specialization
2135 against the declarations. We count the number of template
2136 headers, and we check if they match TEMPLATE_COUNT + 1
2137 (TEMPLATE_COUNT is the number of qualifying template classes,
2138 plus there must be another header for the member template
2139 itself).
2141 Notice that if header_count is zero, this is not a
2142 specialization but rather a template instantiation, so there
2143 is no check we can perform here. */
2147 /* Check that the number of template arguments at the
2148 innermost level for DECL is the same as for FN. */
2156 /* DECL might be a specialization of FN. */
2160 /* For a non-static member function, we need to make sure
2161 that the const qualification is the same. Since
2162 get_bindings does not try to merge the "this" parameter,
2163 we must do the comparison explicitly. */
2169 /* Skip the "this" parameter and, for constructors of
2170 classes with virtual bases, the VTT parameter. A
2171 full specialization of a constructor will have a VTT
2172 parameter, but a template never will. */
2173 decl_arg_types
2175 fn_arg_types
2178 /* Function templates cannot be specializations; there are
2179 no partial specializations of functions. Therefore, if
2180 the type of DECL does not match FN, there is no
2181 match.
2183 Note that it should never be the case that we have both
2184 candidates added here, and for regular member functions
2185 below. */
2187 {
2191 }
2193 /* See whether this function might be a specialization of this
2194 template. Suppress access control because we might be trying
2195 to make this specialization a friend, and we have already done
2196 access control for the declaration of the specialization. */
2202 /* We cannot deduce template arguments that when used to
2203 specialize TMPL will produce DECL. */
2207 /* We deduced something involving 'auto', which isn't a valid
2208 template argument. */
2211 /* Remove, from the set of candidates, all those functions
2212 whose constraints are not satisfied. */
2216 // Then, try to form the new function type.
2220 fn_arg_types
2225 /* Save this template, and the arguments deduced. */
2227 }
2229 /* FN is an ordinary member function, and we need a
2230 specialization of a member template. */
2231 ;
2233 /* We can get IDENTIFIER_NODEs here in certain erroneous
2234 cases. */
2235 ;
2237 /* This is just an ordinary non-member function. Nothing can
2238 be a specialization of that. */
2239 ;
2241 /* Cannot specialize functions that are created implicitly. */
2242 ;
2243 else
2244 {
2245 tree decl_arg_types;
2247 /* This is an ordinary member function. However, since
2248 we're here, we can assume its enclosing class is a
2249 template class. For example,
2251 template <typename T> struct S { void f(); };
2252 template <> void S<int>::f() {}
2254 Here, S<int>::f is a non-template, but S<int> is a
2255 template class. If FN has the same type as DECL, we
2256 might be in business. */
2259 /* Its enclosing class is an explicit specialization
2260 of a template class. This is not a candidate. */
2265 /* The return types differ. */
2268 /* Adjust the type of DECL in case FN is a static member. */
2275 decl_arg_types))
2278 // If the deduced arguments do not satisfy the constraints,
2279 // this is not a candidate.
2283 // Add the candidate.
2285 }
2286 }
2289 {
2290 /* We have:
2292 [temp.expl.spec]
2294 It is possible for a specialization with a given function
2295 signature to be instantiated from more than one function
2296 template. In such cases, explicit specification of the
2297 template arguments must be used to uniquely identify the
2298 function template specialization being specialized.
2300 Note that here, there's no suggestion that we're supposed to
2301 determine which of the candidate templates is most
2302 specialized. However, we, also have:
2304 [temp.func.order]
2306 Partial ordering of overloaded function template
2307 declarations is used in the following contexts to select
2308 the function template to which a function template
2309 specialization refers:
2311 -- when an explicit specialization refers to a function
2312 template.
2314 So, we do use the partial ordering rules, at least for now.
2315 This extension can only serve to make invalid programs valid,
2316 so it's safe. And, there is strong anecdotal evidence that
2317 the committee intended the partial ordering rules to apply;
2318 the EDG front end has that behavior, and John Spicer claims
2319 that the committee simply forgot to delete the wording in
2320 [temp.expl.spec]. */
2323 {
2326 }
2327 }
2329 // Concepts allows multiple declarations of member functions
2330 // with the same signature. Like above, we need to rely on
2331 // on the partial ordering of those candidates to determine which
2332 // is the best.
2334 {
2336 {
2339 }
2340 }
2343 {
2350 else
2353 }
2357 {
2363 }
2365 /* We have one, and exactly one, match. */
2367 {
2371 // Propagate the candidate's constraints to the declaration.
2374 /* DECL is a re-declaration or partial instantiation of a template
2375 function. */
2378 /* It was a specialization of an ordinary member function in a
2379 template class. */
2381 }
2383 /* It was a specialization of a template. */
2386 {
2391 }
2392 else
2395 }
2397 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2398 but with the default argument values filled in from those in the
2399 TMPL_TYPES. */
2401 static tree
2403 tree tmpl_types)
2404 {
2405 tree new_spec_types;
2413 /* Substitute into the rest of the list. */
2414 new_spec_types =
2418 /* Add the default argument for this parameter. */
2421 new_spec_types);
2422 }
2424 /* DECL is an explicit specialization. Replicate default arguments
2425 from the template it specializes. (That way, code like:
2427 template <class T> void f(T = 3);
2428 template <> void f(double);
2429 void g () { f (); }
2431 works, as required.) An alternative approach would be to look up
2432 the correct default arguments at the call-site, but this approach
2433 is consistent with how implicit instantiations are handled. */
2435 static void
2437 {
2438 tree tmpl;
2439 tree spec_types;
2440 tree tmpl_types;
2441 tree new_spec_types;
2442 tree old_type;
2443 tree new_type;
2444 tree t;
2449 /* See if there's anything we need to do. */
2462 {
2463 /* Remove the this pointer, but remember the object's type for
2464 CV quals. */
2470 {
2471 /* DECL may contain more parameters than TMPL due to the extra
2472 in-charge parameter in constructors and destructors. */
2475 }
2477 {
2480 }
2481 }
2483 /* Compute the merged default arguments. */
2484 new_spec_types =
2487 /* Compute the new FUNCTION_TYPE. */
2489 {
2493 new_spec_types);
2496 /* Put the in-charge parameter back. */
2499 new_spec_types);
2503 new_spec_types);
2504 }
2505 else
2507 new_spec_types);
2517 }
2519 /* Return the number of template headers we expect to see for a definition
2520 or specialization of CTYPE or one of its non-template members. */
2522 int
2524 {
2528 {
2529 /* You're supposed to have one `template <...>' for every
2530 template class, but you don't need one for a full
2531 specialization. For example:
2533 template <class T> struct S{};
2534 template <> struct S<int> { void f(); };
2535 void S<int>::f () {}
2537 is correct; there shouldn't be a `template <>' for the
2538 definition of `S<int>::f'. */
2540 /* If CTYPE does not have template information of any
2541 kind, then it is not a template, nor is it nested
2542 within a template. */
2550 }
2553 }
2555 /* Do a simple sanity check on the template headers that precede the
2556 variable declaration DECL. */
2558 void
2560 {
2565 {
2568 "variable templates only available with "
2571 // Namespace-scope variable templates should have a template header.
2573 }
2575 {
2577 "too many template headers for %qD "
2583 "members of an explicitly specialized class are defined "
2585 }
2586 }
2588 /* An explicit specialization whose declarator-id or class-head-name is not
2589 qualified shall be declared in the nearest enclosing namespace of the
2590 template, or, if the namespace is inline (7.3.1), any namespace from its
2591 enclosing namespace set.
2593 If the name declared in the explicit instantiation is an unqualified name,
2594 the explicit instantiation shall appear in the namespace where its template
2595 is declared or, if that namespace is inline (7.3.1), any namespace from its
2596 enclosing namespace set. */
2598 void
2600 {
2605 {
2611 /* This was allowed in C++98, so only pedwarn. */
2613 "outside its namespace must use a nested-name-"
2615 }
2616 }
2618 /* Check to see if the function just declared, as indicated in
2619 DECLARATOR, and in DECL, is a specialization of a function
2620 template. We may also discover that the declaration is an explicit
2621 instantiation at this point.
2623 Returns DECL, or an equivalent declaration that should be used
2624 instead if all goes well. Issues an error message if something is
2625 amiss. Returns error_mark_node if the error is not easily
2626 recoverable.
2628 FLAGS is a bitmask consisting of the following flags:
2630 2: The function has a definition.
2631 4: The function is a friend.
2633 The TEMPLATE_COUNT is the number of references to qualifying
2634 template classes that appeared in the name of the function. For
2635 example, in
2637 template <class T> struct S { void f(); };
2638 void S<int>::f();
2640 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2641 classes are not counted in the TEMPLATE_COUNT, so that in
2643 template <class T> struct S {};
2644 template <> struct S<int> { void f(); }
2645 template <> void S<int>::f();
2647 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2648 invalid; there should be no template <>.)
2650 If the function is a specialization, it is marked as such via
2651 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2652 is set up correctly, and it is added to the list of specializations
2653 for that template. */
2655 tree
2657 tree decl,
2660 {
2669 tmpl_spec_kind tsk;
2672 {
2675 else
2677 }
2678 else
2682 {
2685 {
2688 }
2690 {
2692 /* This could be something like:
2694 template <class T> void f(T);
2695 class S { friend void f<>(int); } */
2697 else
2698 {
2699 /* This case handles bogus declarations like template <>
2700 template <class T> void f<int>(); */
2703 declarator);
2705 }
2706 }
2710 /* The error has already been reported in
2711 check_specialization_scope. */
2717 /* Fall through. */
2730 decl);
2733 else
2737 /* Fall through. */
2743 /* In cases like template<> constexpr bool v = true;
2744 We'll give an error in check_template_variable. */
2750 else
2756 {
2757 /* This case handles bogus declarations like template <>
2758 template <class T> void f<int>(); */
2762 declarator);
2764 {
2765 /* Partial specialization of variable template. */
2769 }
2773 else
2777 ok:;
2778 }
2781 /* This is a specialization of a member template, without
2782 specialization the containing class. Something like:
2784 template <class T> struct S {
2785 template <class U> void f (U);
2786 };
2787 template <> template <class U> void S<int>::f(U) {}
2789 That's a specialization -- but of the entire template. */
2795 }
2798 /* This doesn't apply to variable templates. */
2801 {
2805 {
2809 }
2810 }
2813 {
2818 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2820 {
2821 tree fns;
2826 else
2827 {
2828 /* If there is no class context, the explicit instantiation
2829 must be at namespace scope. */
2832 /* Find the namespace binding, using the declaration
2833 context. */
2837 /* If lookup fails, look for a friend declaration so we can
2838 give a better diagnostic. */
2844 {
2847 }
2848 }
2851 }
2857 {
2859 /* A specialization in class scope. This is invalid,
2860 but the error will already have been flagged by
2861 check_specialization_scope. */
2863 else
2864 {
2865 /* It's not valid to write an explicit instantiation in
2866 class scope, e.g.:
2868 class C { template void f(); }
2870 This case is caught by the parser. However, on
2871 something like:
2873 template class C { void f(); };
2875 (which is invalid) we can get here. The error will be
2876 issued later. */
2877 ;
2878 }
2881 }
2884 {
2885 // We'll match variable templates in start_decl.
2889 /* Find the list of functions in ctype that have the same
2890 name as the declared function. */
2894 {
2898 {
2899 /* From [temp.expl.spec]:
2901 If such an explicit specialization for the member
2902 of a class template names an implicitly-declared
2903 special member function (clause _special_), the
2904 program is ill-formed.
2906 Similar language is found in [temp.explicit]. */
2909 }
2912 }
2914 /* For a type-conversion operator, We might be looking for
2915 `operator int' which will be a specialization of
2916 `operator T'. Grab all the conversion operators, and
2917 then select from them. */
2922 {
2925 }
2926 else
2928 }
2930 /* Figure out what exactly is being specialized at this point.
2931 Note that for an explicit instantiation, even one for a
2932 member function, we cannot tell a priori whether the
2933 instantiation is for a member template, or just a member
2934 function of a template class. Even if a member template is
2935 being instantiated, the member template arguments may be
2936 elided if they can be deduced from the rest of the
2937 declaration. */
2940 member_specialization,
2941 template_count,
2942 tsk);
2945 /* We couldn't figure out what this declaration was
2946 specializing. */
2948 else
2949 {
2952 {
2954 "friend declaration %qD is not visible to "
2958 }
2966 {
2967 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2968 is done by do_decl_instantiation later. */
2974 {
2975 /* If TMPL is not the most general template (for
2976 example, if TMPL is a friend template that is
2977 injected into namespace scope), then there will
2978 be too many levels of TARGS. Remove some of them
2979 here. */
2981 tree new_targs;
2988 }
2991 }
2993 /* If we thought that the DECL was a member function, but it
2994 turns out to be specializing a static member function,
2995 make DECL a static member function as well. */
3001 /* If this is a specialization of a member template of a
3002 template class, we want to return the TEMPLATE_DECL, not
3003 the specialization of it. */
3005 {
3010 {
3011 tree parm;
3015 /* We want to use the argument list specified in the
3016 definition, not in the original declaration. */
3021 }
3024 }
3026 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3032 /* Inherit default function arguments from the template
3033 DECL is specializing. */
3037 /* This specialization has the same protection as the
3038 template it specializes. */
3042 /* 7.1.1-1 [dcl.stc]
3044 A storage-class-specifier shall not be specified in an
3045 explicit specialization...
3047 The parser rejects these, so unless action is taken here,
3048 explicit function specializations will always appear with
3049 global linkage.
3051 The action recommended by the C++ CWG in response to C++
3052 defect report 605 is to make the storage class and linkage
3053 of the explicit specialization match the templated function:
3055 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3056 */
3058 {
3062 /* A concept cannot be specialized. */
3064 {
3066 gen_tmpl);
3068 }
3070 /* This specialization has the same linkage and visibility as
3071 the function template it specializes. */
3074 {
3077 }
3080 {
3083 }
3084 }
3086 /* If DECL is a friend declaration, declared using an
3087 unqualified name, the namespace associated with DECL may
3088 have been set incorrectly. For example, in:
3090 template <typename T> void f(T);
3091 namespace N {
3092 struct S { friend void f<int>(int); }
3093 }
3095 we will have set the DECL_CONTEXT for the friend
3096 declaration to N, rather than to the global namespace. */
3101 /* This is not really a declaration of a specialization.
3102 It's just the name of an instantiation. But, it's not
3103 a request for an instantiation, either. */
3106 /* A specialization is not necessarily COMDAT. */
3112 /* If this is a full specialization, register it so that we can find
3113 it again. Partial specializations will be registered in
3114 process_partial_specialization. */
3119 /* A 'structor should already have clones. */
3125 }
3126 }
3129 }
3131 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3132 parameters. These are represented in the same format used for
3133 DECL_TEMPLATE_PARMS. */
3135 int
3137 {
3138 const_tree p1;
3139 const_tree p2;
3147 {
3159 {
3163 /* If either of the template parameters are invalid, assume
3164 they match for the sake of error recovery. */
3177 }
3178 }
3181 /* One set of parameters has more parameters lists than the
3182 other. */
3186 }
3188 /* Determine whether PARM is a parameter pack. */
3190 bool
3192 {
3193 /* Determine if we have a non-type template parameter pack. */
3200 /* If this is a list of template parameters, we could get a
3201 TYPE_DECL or a TEMPLATE_DECL. */
3205 /* Otherwise it must be a type template parameter. */
3209 }
3211 /* Determine if T is a function parameter pack. */
3213 bool
3215 {
3219 }
3221 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3222 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3224 tree
3226 {
3233 }
3235 /* Return true iff the function parameter PARAM_DECL was expanded
3236 from the function parameter pack PACK. */
3238 bool
3240 {
3245 /* The parameter pack and its pack arguments have the same
3246 DECL_PARM_INDEX. */
3248 }
3250 /* Determine whether ARGS describes a variadic template args list,
3251 i.e., one that is terminated by a template argument pack. */
3253 static bool
3255 {
3257 tree last_parm;
3271 }
3273 /* Generate a new name for the parameter pack name NAME (an
3274 IDENTIFIER_NODE) that incorporates its */
3276 static tree
3278 {
3279 /* Munge the name to include the parameter index. */
3280 #define NUMBUF_LEN 128
3294 }
3296 /* Return true if T is a primary function, class or alias template
3297 specialization, not including the template pattern. */
3299 bool
3301 {
3317 }
3319 /* Return true if PARM is a template template parameter. */
3321 bool
3323 {
3325 }
3327 /* Return true iff PARM is a DECL representing a type template
3328 parameter. */
3330 bool
3332 {
3337 }
3339 /* Return the template parameters of T if T is a
3340 primary template instantiation, NULL otherwise. */
3342 tree
3344 {
3349 parms = INNERMOST_TEMPLATE_PARMS
3353 }
3355 /* Return the template parameters of the LEVELth level from the full list
3356 of template parameters PARMS. */
3358 tree
3360 {
3361 tree p;
3372 }
3374 /* Returns the template arguments of T if T is a template instantiation,
3375 NULL otherwise. */
3377 tree
3379 {
3387 }
3389 /* Return the argument pack elements of T if T is a template argument pack,
3390 NULL otherwise. */
3392 tree
3394 {
3400 }
3402 /* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
3403 ARGUMENT_PACK_SELECT represents. */
3405 static tree
3407 {
3411 /* If the selected argument is an expansion E, that most likely means we were
3412 called from gen_elem_of_pack_expansion_instantiation during the
3413 substituting of an argument pack (of which the Ith element is a pack
3414 expansion, where I is ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
3415 In this case, the Ith element resulting from this substituting is going to
3416 be a pack expansion, which pattern is the pattern of E. Let's return the
3417 pattern of E, and gen_elem_of_pack_expansion_instantiation will build the
3418 resulting pack expansion from it. */
3420 {
3421 /* Make sure we aren't throwing away arg info. */
3424 }
3427 }
3430 /* True iff FN is a function representing a built-in variadic parameter
3431 pack. */
3433 bool
3435 {
3445 }
3447 /* True iff CALL is a call to a function representing a built-in variadic
3448 parameter pack. */
3450 static bool
3452 {
3456 }
3458 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3460 static tree
3462 tree in_decl)
3463 {
3469 {
3471 {
3474 }
3479 }
3480 else
3481 {
3485 /* Calculate the largest value of len that won't make the size of the vec
3486 overflow an int. The compiler will exceed resource limits long before
3487 this, but it seems a decent place to diagnose. */
3491 {
3496 }
3504 }
3505 }
3507 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3508 CALL. */
3510 static tree
3512 tree in_decl)
3513 {
3523 }
3525 /* Structure used to track the progress of find_parameter_packs_r. */
3526 struct find_parameter_pack_data
3527 {
3528 /* TREE_LIST that will contain all of the parameter packs found by
3529 the traversal. */
3532 /* Set of AST nodes that have been visited by the traversal. */
3535 /* True iff we're making a type pack expansion. */
3537 };
3539 /* Identifies all of the argument packs that occur in a template
3540 argument and appends them to the TREE_LIST inside DATA, which is a
3541 find_parameter_pack_data structure. This is a subroutine of
3542 make_pack_expansion and uses_parameter_packs. */
3543 static tree
3545 {
3551 /* Handle type aliases/typedefs. */
3553 {
3560 }
3562 /* Identify whether this is a parameter pack or not. */
3564 {
3572 /* FALLTHRU */
3574 /* If the placeholder appears in the decl-specifier-seq of a function
3575 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3576 is a pack expansion, the invented template parameter is a template
3577 parameter pack. */
3587 {
3588 /* We don't want to walk into the type of a PARM_DECL,
3589 because we don't want to see the type parameter pack. */
3592 }
3597 {
3598 /* We don't want to walk into the type of a variadic capture proxy,
3599 because we don't want to see the type parameter pack. */
3602 }
3604 {
3606 find_parameter_packs_r,
3609 }
3621 /* Not a parameter pack. */
3623 }
3626 {
3627 /* Add this parameter pack to the list. */
3629 }
3635 /* This switch statement will return immediately if we don't find a
3636 parameter pack. */
3638 {
3643 /* Check the template itself. */
3646 /* Check the template arguments. */
3660 /* Ignore the declaration of a capture proxy for a parameter pack. */
3668 /* Fall through. */
3713 {
3714 /* Look at explicit captures. */
3719 /* Since we defer implicit capture, look in the body as well. */
3725 }
3728 {
3729 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3730 type_pack_expansion_p to false so that any placeholders
3731 within the expression don't get marked as parameter packs. */
3739 }
3743 }
3746 }
3748 /* Determines if the expression or type T uses any parameter packs. */
3749 bool
3751 {
3760 }
3762 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3763 representation a base-class initializer into a parameter pack
3764 expansion. If all goes well, the resulting node will be an
3765 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3766 respectively. */
3767 tree
3769 {
3770 tree result;
3779 {
3780 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3781 class initializer. In this case, the TREE_PURPOSE will be a
3782 _TYPE node (representing the base class expansion we're
3783 initializing) and the TREE_VALUE will be a TREE_LIST
3784 containing the initialization arguments.
3786 The resulting expansion looks somewhat different from most
3787 expansions. Rather than returning just one _EXPANSION, we
3788 return a TREE_LIST whose TREE_PURPOSE is a
3789 TYPE_PACK_EXPANSION containing the bases that will be
3790 initialized. The TREE_VALUE will be identical to the
3791 original TREE_VALUE, which is a list of arguments that will
3792 be passed to each base. We do not introduce any new pack
3793 expansion nodes into the TREE_VALUE (although it is possible
3794 that some already exist), because the TREE_PURPOSE and
3795 TREE_VALUE all need to be expanded together with the same
3796 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3797 resulting TREE_PURPOSE will mention the parameter packs in
3798 both the bases and the arguments to the bases. */
3799 tree purpose;
3800 tree value;
3803 /* Determine which parameter packs will be used by the base
3804 class expansion. */
3813 {
3816 arg);
3819 }
3822 {
3823 /* Collect the sets of parameter packs used in each of the
3824 initialization arguments. */
3826 {
3827 /* Determine which parameter packs will be expanded in this
3828 argument. */
3831 }
3832 }
3836 /* Create the pack expansion type for the base type. */
3842 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3843 they will rarely be compared to anything. */
3847 }
3852 /* Build the PACK_EXPANSION_* node. */
3853 result = for_types
3858 {
3859 /* Propagate type and const-expression information. */
3862 /* Mark this read now, since the expansion might be length 0. */
3864 }
3865 else
3866 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3867 they will rarely be compared to anything. */
3870 /* Determine which parameter packs will be expanded. */
3877 /* Make sure we found some parameter packs. */
3879 {
3881 {
3884 else
3886 }
3888 }
3894 }
3896 /* Checks T for any "bare" parameter packs, which have not yet been
3897 expanded, and issues an error if any are found. This operation can
3898 only be done on full expressions or types (e.g., an expression
3899 statement, "if" condition, etc.), because we could have expressions like:
3901 foo(f(g(h(args)))...)
3903 where "args" is a parameter pack. check_for_bare_parameter_packs
3904 should not be called for the subexpressions args, h(args),
3905 g(h(args)), or f(g(h(args))), because we would produce erroneous
3906 error messages.
3908 Returns TRUE and emits an error if there were bare parameter packs,
3909 returns FALSE otherwise. */
3910 bool
3912 {
3919 /* A lambda might use a parameter pack from the containing context. */
3933 {
3937 {
3948 else
3953 else
3957 }
3960 }
3963 }
3965 /* Expand any parameter packs that occur in the template arguments in
3966 ARGS. */
3967 tree
3969 {
3978 /* First, determine if we need to expand anything, and the number of
3979 slots we'll need. */
3981 {
3986 {
3990 else
3992 }
3993 else
3994 {
3996 num_result_args++;
3997 }
3998 }
4000 /* If no expansion is necessary, we're done. */
4004 /* Expand arguments. */
4007 non_default_args_count =
4010 {
4013 {
4020 }
4021 else
4022 {
4025 }
4026 }
4030 }
4032 /* Checks if DECL shadows a template parameter.
4034 [temp.local]: A template-parameter shall not be redeclared within its
4035 scope (including nested scopes).
4037 Emits an error and returns TRUE if the DECL shadows a parameter,
4038 returns FALSE otherwise. */
4040 bool
4042 {
4043 tree olddecl;
4045 /* If we're not in a template, we can't possibly shadow a template
4046 parameter. */
4050 /* Figure out what we're shadowing. */
4054 /* If there's no previous binding for this name, we're not shadowing
4055 anything, let alone a template parameter. */
4059 /* If we're not shadowing a template parameter, we're done. Note
4060 that OLDDECL might be an OVERLOAD (or perhaps even an
4061 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4062 node. */
4066 /* We check for decl != olddecl to avoid bogus errors for using a
4067 name inside a class. We check TPFI to avoid duplicate errors for
4068 inline member templates. */
4074 /* Don't complain about the injected class name, as we've already
4075 complained about the class itself. */
4082 else
4087 }
4089 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4090 ORIG_LEVEL, DECL, and TYPE. */
4092 static tree
4096 tree decl,
4097 tree type)
4098 {
4109 }
4111 /* Find the canonical type parameter for the given template type
4112 parameter. Returns the canonical type parameter, which may be TYPE
4113 if no such parameter existed. */
4115 static tree
4117 {
4118 tree list;
4132 else
4133 {
4137 }
4138 }
4140 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4141 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4142 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4143 new one is created. */
4145 static tree
4147 tsubst_flags_t complain)
4148 {
4153 {
4172 /* Template template parameters need this. */
4174 {
4181 }
4182 }
4185 }
4187 /* Process information from new template parameter PARM and append it
4188 to the LIST being built. This new parameter is a non-type
4189 parameter iff IS_NON_TYPE is true. This new parameter is a
4190 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4191 is in PARM_LOC. */
4193 tree
4196 {
4205 {
4209 {
4213 else
4215 }
4218 }
4221 {
4227 {
4228 /* [temp.param]
4230 The top-level cv-qualifiers on the template-parameter are
4231 ignored when determining its type. */
4236 && !is_parameter_pack
4237 /* If we're in a nested template parameter list, the template
4238 template parameter could be a parameter pack. */
4240 {
4241 /* This template parameter is not a parameter pack, but it
4242 should be. Complain about "bare" parameter packs. */
4245 /* Recover by calling this a parameter pack. */
4247 }
4248 }
4250 /* A template parameter is not modifiable. */
4259 processing_template_decl,
4264 }
4265 else
4266 {
4267 tree t;
4271 {
4273 /* This is for distinguishing between real templates and template
4274 template parameters */
4278 }
4279 else
4280 {
4282 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4285 }
4292 processing_template_decl,
4296 }
4300 /* Build requirements for the type/template parameter.
4301 This must be done after SET_DECL_TEMPLATE_PARM_P or
4302 process_template_parm could fail. */
4307 /* Build the parameter node linking the parameter declaration,
4308 its default argument (if any), and its constraints (if any). */
4313 }
4315 /* The end of a template parameter list has been reached. Process the
4316 tree list into a parameter vector, converting each parameter into a more
4317 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4318 as PARM_DECLs. */
4320 tree
4322 {
4327 /* Pop the dummy parameter level and add the real one. */
4330 current_template_parms
4335 {
4339 }
4344 }
4346 // Explicitly indicate the end of the template parameter list. We assume
4347 // that the current template parameters have been constructed and/or
4348 // managed explicitly, as when creating new template template parameters
4349 // from a shorthand constraint.
4350 void
4352 {
4354 }
4356 /* end_template_decl is called after a template declaration is seen. */
4358 void
4360 {
4366 /* This matches the pushlevel in begin_template_parm_list. */
4371 }
4373 /* Takes a TREE_LIST representing a template parameter and convert it
4374 into an argument suitable to be passed to the type substitution
4375 functions. Note that If the TREE_LIST contains an error_mark
4376 node, the returned argument is error_mark_node. */
4378 tree
4380 {
4393 {
4397 {
4398 /* Turn this argument into a TYPE_ARGUMENT_PACK
4399 with a single element, which expands T. */
4408 }
4409 }
4410 else
4411 {
4415 {
4416 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4417 with a single element, which expands T. */
4427 }
4428 else
4430 }
4432 }
4434 /* Given a single level of template parameters (a TREE_VEC), return it
4435 as a set of template arguments. */
4437 static tree
4439 {
4449 }
4451 /* Given a set of template parameters, return them as a set of template
4452 arguments. The template parameters are represented as a TREE_VEC, in
4453 the form documented in cp-tree.h for template arguments. */
4455 static tree
4457 {
4458 tree header;
4463 /* If there is only one level of template parameters, we do not
4464 create a TREE_VEC of TREE_VECs. Instead, we return a single
4465 TREE_VEC containing the arguments. */
4470 {
4475 else
4477 }
4480 }
4482 /* Within the declaration of a template, return the currently active
4483 template parameters as an argument TREE_VEC. */
4485 static tree
4487 {
4489 }
4491 /* Update the declared TYPE by doing any lookups which were thought to be
4492 dependent, but are not now that we know the SCOPE of the declarator. */
4494 tree
4496 {
4507 /* Don't bother building up the args in this case. */
4509 {
4510 /* tsubst in the args corresponding to the template parameters,
4511 including auto if present. Most things will be unchanged, but
4512 make_typename_type and tsubst_qualified_id will resolve
4513 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4516 tree pushed;
4518 {
4522 }
4527 }
4533 {
4536 else
4538 }
4540 }
4542 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4543 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4544 the new template is a member template. */
4546 tree
4548 {
4556 }
4558 struct template_parm_data
4559 {
4560 /* The level of the template parameters we are currently
4561 processing. */
4564 /* The index of the specialization argument we are currently
4565 processing. */
4568 /* An array whose size is the number of template parameters. The
4569 elements are nonzero if the parameter has been used in any one
4570 of the arguments processed so far. */
4573 /* An array whose size is the number of template arguments. The
4574 elements are nonzero if the argument makes use of template
4575 parameters of this level. */
4577 };
4579 /* Subroutine of push_template_decl used to see if each template
4580 parameter in a partial specialization is used in the explicit
4581 argument list. If T is of the LEVEL given in DATA (which is
4582 treated as a template_parm_data*), then DATA->PARMS is marked
4583 appropriately. */
4585 static int
4587 {
4595 {
4598 }
4600 /* In C++17 the type of a non-type argument is a deduced context. */
4605 data,
4606 NULL,
4609 /* Return zero so that for_each_template_parm will continue the
4610 traversal of the tree; we want to mark *every* template parm. */
4612 }
4614 /* Process the partial specialization DECL. */
4616 static tree
4618 {
4625 tree inner_parms;
4626 tree inst;
4636 /* A concept cannot be specialized. */
4638 {
4641 }
4646 /* We check that each of the template parameters given in the
4647 partial specialization is used in the argument list to the
4648 specialization. For example:
4650 template <class T> struct S;
4651 template <class T> struct S<T*>;
4653 The second declaration is OK because `T*' uses the template
4654 parameter T, whereas
4656 template <class T> struct S<int>;
4658 is no good. Even trickier is:
4660 template <class T>
4661 struct S1
4662 {
4663 template <class U>
4664 struct S2;
4665 template <class U>
4666 struct S2<T>;
4667 };
4669 The S2<T> declaration is actually invalid; it is a
4670 full-specialization. Of course,
4672 template <class U>
4673 struct S2<T (*)(U)>;
4675 or some such would have been OK. */
4683 {
4688 NULL,
4690 }
4693 {
4694 /* One of the template parms was not used in a deduced context in the
4695 specialization. */
4697 {
4701 }
4705 }
4710 /* [temp.class.spec]
4712 The argument list of the specialization shall not be identical to
4713 the implicit argument list of the primary template. */
4714 tree main_args
4717 && (!flag_concepts
4720 {
4724 else
4728 }
4730 /* A partial specialization that replaces multiple parameters of the
4731 primary template with a pack expansion is less specialized for those
4732 parameters. */
4734 {
4736 "primary template because it replaces multiple parameters "
4739 /* Avoid crash in process_partial_specialization. */
4741 }
4743 /* If we aren't in a dependent class, we can actually try deduction. */
4745 /* FIXME we should be able to handle a partial specialization of a
4746 partial instantiation, but currently we can't (c++/41727). */
4749 {
4753 maintmpl);
4754 }
4756 /* [temp.class.spec]
4758 A partially specialized non-type argument expression shall not
4759 involve template parameters of the partial specialization except
4760 when the argument expression is a simple identifier.
4762 The type of a template parameter corresponding to a specialized
4763 non-type argument shall not be dependent on a parameter of the
4764 specialization.
4766 Also, we verify that pack expansions only occur at the
4767 end of the argument list. */
4771 {
4778 {
4779 /* Extract the arguments from the argument pack. We'll be
4780 iterating over these in the following loop. */
4783 }
4786 {
4788 /* Get the Jth argument in the parameter pack. */
4792 {
4793 /* Pack expansions must come at the end of the
4794 argument list. */
4797 {
4801 else
4804 }
4805 }
4808 /* We only care about the pattern. */
4814 /* This next two lines are the `argument expression is not just a
4815 simple identifier' condition and also the `specialized
4816 non-type argument' bit. */
4820 {
4824 arg);
4825 else
4826 {
4827 /* Look at the corresponding template parameter,
4828 marking which template parameters its type depends
4829 upon. */
4833 {
4834 /* We haven't yet initialized TPD2. Do so now. */
4836 /* The number of parameters here is the number in the
4837 main template, which, as checked in the assertion
4838 above, is NARGS. */
4842 }
4844 /* Mark the template parameters. But this time, we're
4845 looking for the template parameters of the main
4846 template, not in the specialization. */
4853 NULL,
4857 {
4858 /* The type depended on some template parameters.
4859 If they are fully specialized in the
4860 specialization, that's OK. */
4869 "type %qT of template argument %qE depends "
4871 "type %qT of template argument %qE depends "
4873 type,
4874 arg);
4875 }
4876 }
4877 }
4878 }
4879 }
4881 /* We should only get here once. */
4885 // Build the template decl.
4894 /* Give template template parms a DECL_CONTEXT of the template
4895 for which they are a parameter. */
4897 {
4901 }
4904 /* We didn't register this in check_explicit_specialization so we could
4905 wait until the constraints were set. */
4907 else
4917 {
4923 {
4931 "declaration of %qD ambiguates earlier template "
4935 "partial specialization of %qD after instantiation "
4937 }
4938 }
4941 }
4943 /* PARM is a template parameter of some form; return the corresponding
4944 TEMPLATE_PARM_INDEX. */
4946 static tree
4948 {
4961 }
4963 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4964 parameter packs used by the template parameter PARM. */
4966 static void
4968 {
4969 /* A type parm can't refer to another parm. */
4973 {
4977 }
4984 }
4986 /* PARM is a template parameter pack. Return any parameter packs used in
4987 its type or the type of any of its template parameters. If there are
4988 any such packs, it will be instantiated into a fixed template parameter
4989 list by partial instantiation rather than be fully deduced. */
4991 tree
4993 {
4994 /* This can only be true in a member template. */
4997 /* This can only be true for a parameter pack. */
5000 /* A type parm can't refer to another parm. */
5014 }
5016 /* Check that a template declaration's use of default arguments and
5017 parameter packs is not invalid. Here, PARMS are the template
5018 parameters. IS_PRIMARY is true if DECL is the thing declared by
5019 a primary template. IS_PARTIAL is true if DECL is a partial
5020 specialization.
5022 IS_FRIEND_DECL is nonzero if DECL is either a non-defining friend
5023 function template declaration or a friend class template
5024 declaration. In the function case, 1 indicates a declaration, 2
5025 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
5026 emitted for extraneous default arguments.
5028 Returns TRUE if there were no errors found, FALSE otherwise. */
5030 bool
5033 {
5036 tree parm_level;
5039 /* [temp.param]
5041 A default template-argument shall not be specified in a
5042 function template declaration or a function template definition, nor
5043 in the template-parameter-list of the definition of a member of a
5044 class template. */
5048 /* You can't have a function template declaration in a local
5049 scope, nor you can you define a member of a class template in a
5050 local scope. */
5058 /* A lambda doesn't have an explicit declaration; don't complain
5059 about the parms of the enclosing class. */
5066 /* If this is either a friend defined in the scope of the class
5067 or a member function. */
5073 /* And, if it was a member function, it really was defined in
5074 the scope of the class. */
5077 /* We already checked these parameters when the template was
5078 declared, so there's no need to do it again now. This function
5079 was defined in class scope, but we're processing its body now
5080 that the class is complete. */
5083 /* Core issue 226 (C++0x only): the following only applies to class
5084 templates. */
5087 {
5088 /* [temp.param]
5090 If a template-parameter has a default template-argument, all
5091 subsequent template-parameters shall have a default
5092 template-argument supplied. */
5094 {
5101 {
5111 {
5113 /* For better subsequent error-recovery, we indicate that
5114 there should have been a default argument. */
5117 }
5119 && !is_friend_decl
5120 /* Don't complain about an enclosing partial
5121 specialization. */
5126 /* A fixed parameter pack will be partially
5127 instantiated into a fixed length list. */
5129 {
5130 /* A primary class template can only have one
5131 parameter pack, at the end of the template
5132 parameter list. */
5140 }
5141 }
5142 }
5143 }
5146 || is_partial
5147 || !is_primary
5149 /* For an ordinary class template, default template arguments are
5150 allowed at the innermost level, e.g.:
5151 template <class T = int>
5152 struct S {};
5153 but, in a partial specialization, they're not allowed even
5154 there, as we have in [temp.class.spec]:
5156 The template parameter list of a specialization shall not
5157 contain default template argument values.
5159 So, for a partial specialization, or for a function template
5160 (in C++98/C++03), we look at all of them. */
5161 ;
5162 else
5163 /* But, for a primary class template that is not a partial
5164 specialization we look at all template parameters except the
5165 innermost ones. */
5168 /* Figure out what error message to issue. */
5183 else
5184 /* Per [temp.param]/9, "A default template-argument shall not be
5185 specified in the template-parameter-lists of the definition of
5186 a member of a class template that appears outside of the member's
5187 class.", thus if we aren't handling a member of a class template
5188 there is no need to examine the parameters. */
5192 /* If we're inside a class definition, there's no need to
5193 examine the parameters to the class itself. On the one
5194 hand, they will be checked when the class is defined, and,
5195 on the other, default arguments are valid in things like:
5196 template <class T = double>
5197 struct S { template <class U> void f(U); };
5198 Here the default argument for `S' has no bearing on the
5199 declaration of `f'. */
5201 else
5202 /* Check everything. */
5208 {
5215 {
5220 {
5222 {
5229 }
5231 /* Clear out the default argument so that we are not
5232 confused later. */
5234 }
5235 }
5237 /* At this point, if we're still interested in issuing messages,
5238 they must apply to classes surrounding the object declared. */
5242 }
5245 }
5247 /* Worker for push_template_decl_real, called via
5248 for_each_template_parm. DATA is really an int, indicating the
5249 level of the parameters we are interested in. If T is a template
5250 parameter of that level, return nonzero. */
5252 static int
5254 {
5260 else
5263 }
5265 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5266 DATA is really an int, indicating the innermost outer level of parameters.
5267 If T is a template parameter of that level or further out, return
5268 nonzero. */
5270 static int
5272 {
5278 else
5281 }
5283 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5284 parameters given by current_template_args, or reuses a
5285 previously existing one, if appropriate. Returns the DECL, or an
5286 equivalent one, if it is replaced via a call to duplicate_decls.
5288 If IS_FRIEND is true, DECL is a friend declaration. */
5290 tree
5292 {
5293 tree tmpl;
5294 tree args;
5295 tree info;
5296 tree ctx;
5300 /* True if the template is a member template, in the sense of
5301 [temp.mem]. */
5307 /* See if this is a partial specialization. */
5320 /* For a friend, we want the context of the friend, not
5321 the type of which it is a friend. */
5325 /* In the case of a virtual function, we want the class in which
5326 it is defined. */
5328 else
5329 /* Otherwise, if we're currently defining some class, the DECL
5330 is assumed to be a member of the class. */
5339 /* See if this is a primary template. */
5342 /* A friend template that specifies a class context, i.e.
5343 template <typename T> friend void A<T>::f();
5344 is not primary. */
5349 else
5353 {
5360 {
5363 }
5365 {
5367 {
5370 }
5372 {
5373 /* [temp.mem]
5375 A destructor shall not be a member template. */
5378 }
5385 {
5386 /* [basic.stc.dynamic.allocation]
5388 An allocation function can be a function
5389 template. ... Template allocation functions shall
5390 have two or more parameters. */
5393 }
5394 }
5397 {
5398 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5401 {
5407 }
5408 }
5411 /* alias-declaration */
5415 else
5416 {
5419 }
5420 }
5422 /* Check to see that the rules regarding the use of default
5423 arguments are not being violated. We check args for a friend
5424 functions when we know whether it's a definition, introducing
5425 declaration or re-declaration. */
5430 /* Ensure that there are no parameter packs in the type of this
5431 declaration that have not been expanded. */
5433 {
5434 /* Check each of the arguments individually to see if there are
5435 any bare parameter packs. */
5441 {
5444 {
5445 /* This is a PARM_DECL that contains unexpanded parameter
5446 packs. We have already complained about this in the
5447 check_for_bare_parameter_packs call, so just replace
5448 these types with ERROR_MARK_NODE. */
5451 }
5455 }
5457 /* Check for bare parameter packs in the return type and the
5458 exception specifiers. */
5460 /* Errors were already issued, set return type to int
5461 as the frontend doesn't expect error_mark_node as
5462 the return type. */
5466 }
5471 {
5474 }
5487 {
5492 /* If DECL is a TYPE_DECL for a class-template, then there won't
5493 be DECL_LANG_SPECIFIC. The information equivalent to
5494 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5498 {
5499 /* Since a template declaration already existed for this
5500 class-type, we must be redeclaring it here. Make sure
5501 that the redeclaration is valid. */
5503 current_template_parms,
5505 /* We don't need to create a new TEMPLATE_DECL; just use the
5506 one we already had. */
5508 }
5509 else
5510 {
5512 member_template_p);
5517 {
5518 /* A specialization of a member template of a template
5519 class. */
5523 }
5524 }
5525 }
5526 else
5527 {
5533 {
5536 }
5544 {
5545 tree new_tmpl;
5547 /* The declaration is a specialization of a member
5548 template, declared outside the class. Therefore, the
5549 innermost template arguments will be NULL, so we
5550 replace them with the arguments determined by the
5551 earlier call to check_explicit_specialization. */
5554 new_tmpl
5556 member_template_p);
5566 args,
5569 }
5571 /* Make sure the template headers we got make sense. */
5576 {
5581 }
5582 else
5584 {
5589 {
5593 else
5597 /* Avoid crash in import_export_decl. */
5600 }
5605 /* Can happen in erroneous input. */
5607 else
5609 }
5611 /* Check that the parms are used in the appropriate qualifying scopes
5612 in the declarator. */
5616 {
5622 /* Avoid crash in import_export_decl. */
5625 }
5626 }
5631 /* Push template declarations for global functions and types. Note
5632 that we do not try to push a global template friend declared in a
5633 template class; such a thing may well depend on the template
5634 parameters of the class. */
5637 {
5642 /* Hide template friend classes that haven't been declared yet. */
5644 {
5647 }
5648 }
5651 {
5656 /* Give template template parms a DECL_CONTEXT of the template
5657 for which they are a parameter. */
5660 {
5664 }
5670 }
5672 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5673 back to its most general template. If TMPL is a specialization,
5674 ARGS may only have the innermost set of arguments. Add the missing
5675 argument levels if necessary. */
5683 else
5684 {
5689 }
5692 && !is_friend
5695 /* Set DECL_COMDAT on template instantiations; if we force
5696 them to be emitted by explicit instantiation or -frepo,
5697 mark_needed will tell cgraph to do the right thing. */
5701 }
5703 tree
5705 {
5707 }
5709 /* FN is an inheriting constructor that inherits from the constructor
5710 template INHERITED; turn FN into a constructor template with a matching
5711 template header. */
5713 tree
5715 {
5716 tree inner_parms
5719 tree parms
5730 }
5732 /* Called when a class template TYPE is redeclared with the indicated
5733 template PARMS, e.g.:
5735 template <class T> struct S;
5736 template <class T> struct S {}; */
5738 bool
5740 {
5741 tree tmpl;
5742 tree tmpl_parms;
5746 {
5749 }
5753 /* The type is nested in some template class. Nothing to worry
5754 about here; there are no new template parameters for the nested
5755 type. */
5759 {
5761 tmpl);
5763 }
5769 {
5779 }
5782 {
5783 tree tmpl_parm;
5784 tree parm;
5785 tree tmpl_default;
5786 tree parm_default;
5800 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5801 TEMPLATE_DECL. */
5811 {
5815 }
5818 {
5819 /* We have in [temp.param]:
5821 A template-parameter may not be given default arguments
5822 by two different declarations in the same scope. */
5827 }
5830 /* Update the previous template parameters (which are the ones
5831 that will really count) with the new default value. */
5834 /* Update the new parameters, too; they'll be used as the
5835 parameters for any members. */
5838 /* Give each template template parm in this redeclaration a
5839 DECL_CONTEXT of the template for which they are a parameter. */
5841 {
5844 }
5848 }
5850 // Cannot redeclare a class template with a different set of constraints.
5852 {
5857 }
5860 }
5862 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5863 to be used when the caller has already checked
5864 (processing_template_decl
5865 && !instantiation_dependent_expression_p (expr)
5866 && potential_constant_expression (expr))
5867 and cleared processing_template_decl. */
5869 tree
5871 {
5874 complain,
5878 }
5880 /* Simplify EXPR if it is a non-dependent expression. Returns the
5881 (possibly simplified) expression. */
5883 tree
5885 {
5889 /* If we're in a template, but EXPR isn't value dependent, simplify
5890 it. We're supposed to treat:
5892 template <typename T> void f(T[1 + 1]);
5893 template <typename T> void f(T[2]);
5895 as two declarations of the same function, for example. */
5898 {
5899 processing_template_decl_sentinel s;
5901 }
5903 }
5905 tree
5907 {
5909 }
5911 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5912 an uninstantiated expression. */
5914 tree
5916 {
5920 {
5923 else
5924 {
5925 processing_template_decl_sentinel s;
5927 }
5928 }
5930 }
5932 /* True iff T is a specialization of a variable template. */
5934 bool
5936 {
5941 }
5943 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5944 template declaration, or a TYPE_DECL for an alias declaration. */
5946 bool
5948 {
5956 }
5958 /* Return TRUE iff T is a specialization of an alias template. */
5960 bool
5962 {
5963 /* It's an alias template specialization if it's an alias and its
5964 TYPE_NAME is a specialization of a primary template. */
5970 }
5972 /* An alias template is complex from a SFINAE perspective if a template-id
5973 using that alias can be ill-formed when the expansion is not, as with
5974 the void_t template. We determine this by checking whether the
5975 expansion for the alias template uses all its template parameters. */
5977 struct uses_all_template_parms_data
5978 {
5981 };
5983 static int
5985 {
5993 }
5995 static bool
5997 {
6012 }
6014 /* Return TRUE iff T is a specialization of a complex alias template with
6015 dependent template-arguments. */
6017 bool
6019 {
6032 }
6034 /* Return the number of innermost template parameters in TMPL. */
6036 static int
6038 {
6041 }
6043 /* Return either TMPL or another template that it is equivalent to under DR
6044 1286: An alias that just changes the name of a template is equivalent to
6045 the other template. */
6047 static tree
6049 {
6052 {
6053 /* Determine if the alias is equivalent to an underlying template. */
6065 tree alias_args = INNERMOST_TEMPLATE_ARGS
6070 /* Alias is equivalent. Strip it and repeat. */
6072 }
6075 }
6077 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6078 must be a reference-to-function or a pointer-to-function type, as specified
6079 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6080 and check that the resulting function has external linkage. */
6082 static tree
6084 tsubst_flags_t complain)
6085 {
6088 linkage_kind linkage;
6103 /* [temp.arg.nontype]/1
6105 A template-argument for a non-type, non-template template-parameter
6106 shall be one of:
6107 [...]
6108 -- the address of an object or function with external [C++11: or
6109 internal] linkage. */
6112 {
6114 {
6120 else
6123 }
6125 }
6129 {
6131 {
6136 else
6140 }
6142 }
6144 accept:
6146 {
6149 else
6151 }
6156 }
6158 /* Subroutine of convert_nontype_argument.
6159 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6160 Emit an error otherwise. */
6162 static bool
6164 tsubst_flags_t complain)
6165 {
6182 {
6187 else
6189 }
6191 }
6193 /* Returns TRUE iff the address of OP is value-dependent.
6195 14.6.2.4 [temp.dep.temp]:
6196 A non-integral non-type template-argument is dependent if its type is
6197 dependent or it has either of the following forms
6198 qualified-id
6199 & qualified-id
6200 and contains a nested-name-specifier which specifies a class-name that
6201 names a dependent type.
6203 We generalize this to just say that the address of a member of a
6204 dependent class is value-dependent; the above doesn't cover the
6205 address of a static data member named with an unqualified-id. */
6207 static bool
6209 {
6210 /* We could use get_inner_reference here, but there's no need;
6211 this is only relevant for template non-type arguments, which
6212 can only be expressed as &id-expression. */
6214 {
6218 }
6221 }
6223 /* The next set of functions are used for providing helpful explanatory
6224 diagnostics for failed overload resolution. Their messages should be
6225 indented by two spaces for consistency with the messages in
6226 call.c */
6228 static int
6230 {
6232 }
6234 /* Other failure functions should call this one, to provide a single function
6235 for setting a breakpoint on. */
6237 static int
6239 {
6241 }
6243 static int
6245 {
6250 }
6252 static int
6254 {
6260 }
6262 static int
6264 {
6268 }
6270 static int
6272 {
6275 " template parameter %qD is not a parameter pack, but "
6279 }
6281 static int
6283 {
6286 " template argument %qE does not match "
6290 }
6292 static int
6294 {
6298 }
6300 static int
6302 {
6308 }
6310 static int
6312 {
6314 {
6319 else
6321 " deduced conflicting values for non-type parameter "
6323 }
6325 }
6327 static int
6329 {
6332 " variable-sized array type %qT is not "
6334 arg);
6336 }
6338 static int
6340 {
6344 arg);
6346 }
6348 static int
6350 {
6352 {
6358 else
6363 }
6365 }
6367 static int
6369 {
6371 }
6373 static int
6376 {
6378 }
6380 static int
6383 {
6389 }
6391 static int
6394 {
6397 {
6405 }
6407 }
6409 static int
6411 {
6414 " template parameters of a template template argument are "
6417 }
6419 static int
6421 {
6427 }
6429 static int
6431 {
6436 }
6438 /* Attempt to convert the non-type template parameter EXPR to the
6439 indicated TYPE. If the conversion is successful, return the
6440 converted value. If the conversion is unsuccessful, return
6441 NULL_TREE if we issued an error message, or error_mark_node if we
6442 did not. We issue error messages for out-and-out bad template
6443 parameters, but not simply because the conversion failed, since we
6444 might be just trying to do argument deduction. Both TYPE and EXPR
6445 must be non-dependent.
6447 The conversion follows the special rules described in
6448 [temp.arg.nontype], and it is much more strict than an implicit
6449 conversion.
6451 This function is called twice for each template argument (see
6452 lookup_template_class for a more accurate description of this
6453 problem). This means that we need to handle expressions which
6454 are not valid in a C++ source, but can be created from the
6455 first call (for instance, casts to perform conversions). These
6456 hacks can go away after we fix the double coercion problem. */
6458 static tree
6460 {
6461 tree expr_type;
6465 /* Detect immediately string literals as invalid non-type argument.
6466 This special-case is not needed for correctness (we would easily
6467 catch this later), but only to provide better diagnostic for this
6468 common user mistake. As suggested by DR 100, we do not mention
6469 linkage issues in the diagnostic as this is not the point. */
6470 /* FIXME we're making this OK. */
6472 {
6478 }
6480 /* Add the ADDR_EXPR now for the benefit of
6481 value_dependent_expression_p. */
6484 {
6488 }
6490 /* If we are in a template, EXPR may be non-dependent, but still
6491 have a syntactic, rather than semantic, form. For example, EXPR
6492 might be a SCOPE_REF, rather than the VAR_DECL to which the
6493 SCOPE_REF refers. Preserving the qualifying scope is necessary
6494 so that access checking can be performed when the template is
6495 instantiated -- but here we need the resolved form so that we can
6496 convert the argument. */
6508 /* If the argument is non-dependent, perform any conversions in
6509 non-dependent context as well. */
6517 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6518 to a non-type argument of "nullptr". */
6522 /* In C++11, integral or enumeration non-type template arguments can be
6523 arbitrary constant expressions. Pointer and pointer to
6524 member arguments can be general constant expressions that evaluate
6525 to a null value, but otherwise still need to be of a specific form. */
6527 {
6529 /* A PTRMEM_CST is already constant, and a valid template
6530 argument for a parameter of pointer to member type, we just want
6531 to leave it in that form rather than lower it to a
6535 {
6536 /* C++17: A template-argument for a non-type template-parameter shall
6537 be a converted constant expression (8.20) of the type of the
6538 template-parameter. */
6544 }
6546 {
6551 }
6552 }
6556 else
6559 /* HACK: Due to double coercion, we can get a
6560 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6561 which is the tree that we built on the first call (see
6562 below when coercing to reference to object or to reference to
6563 function). We just strip everything and get to the arg.
6564 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6565 for examples. */
6567 {
6573 {
6574 /* ??? Maybe we could use convert_from_reference here, but we
6575 would need to relax its constraints because the NOP_EXPR
6576 could actually change the type to something more cv-qualified,
6577 and this is not folded by convert_from_reference. */
6582 && (same_type_ignoring_top_level_qualifiers_p
6585 {
6588 }
6589 }
6590 }
6592 /* [temp.arg.nontype]/5, bullet 1
6594 For a non-type template-parameter of integral or enumeration type,
6595 integral promotions (_conv.prom_) and integral conversions
6596 (_conv.integral_) are applied. */
6598 {
6600 {
6605 }
6610 /* Notice that there are constant expressions like '4 % 0' which
6611 do not fold into integer constants. */
6614 {
6616 {
6620 else
6626 /* else cxx_constant_value complained but gave us
6627 a real constant, so go ahead. */
6629 {
6630 /* Some assemble time constant expressions like
6631 (intptr_t)&&lab1 - (intptr_t)&&lab2 or
6632 4 + (intptr_t)&&var satisfy reduced_constant_expression_p
6633 as we can emit them into .rodata initializers of
6634 variables, yet they can't fold into an INTEGER_CST at
6635 compile time. Refuse them here. */
6640 }
6641 }
6642 else
6644 }
6646 /* Avoid typedef problems. */
6649 }
6650 /* [temp.arg.nontype]/5, bullet 2
6652 For a non-type template-parameter of type pointer to object,
6653 qualification conversions (_conv.qual_) and the array-to-pointer
6654 conversion (_conv.array_) are applied. */
6656 {
6659 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6660 decay_conversion or an explicit cast. If it's a problematic cast,
6661 we'll complain about it below. */
6663 {
6668 {
6671 }
6672 }
6674 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6676 A template-argument for a non-type, non-template template-parameter
6677 shall be one of: [...]
6679 -- the name of a non-type template-parameter;
6680 -- the address of an object or function with external linkage, [...]
6681 expressed as "& id-expression" where the & is optional if the name
6682 refers to a function or array, or if the corresponding
6683 template-parameter is a reference.
6685 Here, we do not care about functions, as they are invalid anyway
6686 for a parameter of type pointer-to-object. */
6689 /* Non-type template parameters are OK. */
6690 ;
6694 {
6696 {
6699 "because %qD is a variable, not the address of "
6702 }
6704 {
6710 }
6711 /* Other values, like integer constants, might be valid
6712 non-type arguments of some other type. */
6714 }
6715 else
6716 {
6720 {
6725 }
6727 {
6733 }
6736 {
6741 }
6742 /* C++17: For a non-type template-parameter of reference or pointer
6743 type, the value of the constant expression shall not refer to (or
6744 for a pointer type, shall not be the address of):
6745 * a subobject (4.5),
6746 * a temporary object (15.2),
6747 * a string literal (5.13.5),
6748 * the result of a typeid expression (8.2.8), or
6749 * a predefined __func__ variable (11.4.1). */
6751 {
6754 decl);
6756 }
6760 {
6765 }
6767 {
6771 decl);
6773 }
6774 }
6781 }
6782 /* [temp.arg.nontype]/5, bullet 3
6784 For a non-type template-parameter of type reference to object, no
6785 conversions apply. The type referred to by the reference may be more
6786 cv-qualified than the (otherwise identical) type of the
6787 template-argument. The template-parameter is bound directly to the
6788 template-argument, which must be an lvalue. */
6790 {
6792 expr_type))
6796 {
6801 }
6804 {
6809 }
6811 /* [temp.arg.nontype]/1
6813 A template-argument for a non-type, non-template template-parameter
6814 shall be one of: [...]
6816 -- the address of an object or function with external linkage. */
6819 {
6822 {
6825 "because a reference variable does not have a constant "
6828 }
6829 }
6833 /* OK, dependent reference. We don't want to ask whether a DECL is
6835 else
6836 {
6838 {
6844 }
6846 /* DR 1155 allows internal linkage in C++11 and up. */
6849 {
6855 }
6858 }
6862 }
6863 /* [temp.arg.nontype]/5, bullet 4
6865 For a non-type template-parameter of type pointer to function, only
6866 the function-to-pointer conversion (_conv.func_) is applied. If the
6867 template-argument represents a set of overloaded functions (or a
6868 pointer to such), the matching function is selected from the set
6869 (_over.over_). */
6871 {
6872 /* If the argument is a template-id, we might not have enough
6873 context information to decay the pointer. */
6875 {
6879 }
6882 /* Null pointer values are OK in C++11. */
6888 }
6889 /* [temp.arg.nontype]/5, bullet 5
6891 For a non-type template-parameter of type reference to function, no
6892 conversions apply. If the template-argument represents a set of
6893 overloaded functions, the matching function is selected from the set
6894 (_over.over_). */
6896 {
6898 {
6900 {
6905 }
6907 }
6912 }
6913 /* [temp.arg.nontype]/5, bullet 6
6915 For a non-type template-parameter of type pointer to member function,
6916 no conversions apply. If the template-argument represents a set of
6917 overloaded member functions, the matching member function is selected
6918 from the set (_over.over_). */
6920 {
6925 /* [temp.arg.nontype] bullet 1 says the pointer to member
6926 expression must be a pointer-to-member constant. */
6931 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6932 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6935 }
6936 /* [temp.arg.nontype]/5, bullet 7
6938 For a non-type template-parameter of type pointer to data member,
6939 qualification conversions (_conv.qual_) are applied. */
6941 {
6942 /* [temp.arg.nontype] bullet 1 says the pointer to member
6943 expression must be a pointer-to-member constant. */
6951 }
6953 {
6955 {
6960 }
6962 }
6963 /* A template non-type parameter must be one of the above. */
6964 else
6967 /* Sanity check: did we actually convert the argument to the
6968 right type? */
6972 }
6974 /* Subroutine of coerce_template_template_parms, which returns 1 if
6975 PARM_PARM and ARG_PARM match using the rule for the template
6976 parameters of template template parameters. Both PARM and ARG are
6977 template parameters; the rest of the arguments are the same as for
6978 coerce_template_template_parms.
6979 */
6980 static int
6982 tree arg,
6983 tsubst_flags_t complain,
6984 tree in_decl,
6985 tree outer_args)
6986 {
6995 {
6997 /* We encounter instantiations of templates like
6998 template <template <template <class> class> class TT>
6999 class C; */
7000 {
7007 }
7008 /* Fall through. */
7013 /* Argument is a parameter pack but parameter is not. */
7018 /* The tsubst call is used to handle cases such as
7020 template <int> class C {};
7021 template <class T, template <T> class TT> class D {};
7022 D<int, C> d;
7024 i.e. the parameter list of TT depends on earlier parameters. */
7026 {
7031 }
7035 /* Argument is a parameter pack but parameter is not. */
7042 }
7045 }
7047 /* Coerce template argument list ARGLIST for use with template
7048 template-parameter TEMPL. */
7050 static tree
7052 tsubst_flags_t complain)
7053 {
7054 /* Consider an example where a template template parameter declared as
7056 template <class T, class U = std::allocator<T> > class TT
7058 The template parameter level of T and U are one level larger than
7059 of TT. To proper process the default argument of U, say when an
7060 instantiation `TT<int>' is seen, we need to build the full
7061 arguments containing {int} as the innermost level. Outer levels,
7062 available when not appearing as default template argument, can be
7063 obtained from the arguments of the enclosing template.
7065 Suppose that TT is later substituted with std::vector. The above
7066 instantiation is `TT<int, std::allocator<T> >' with TT at
7067 level 1, and T at level 2, while the template arguments at level 1
7068 becomes {std::vector} and the inner level 2 is {int}. */
7072 {
7074 /* We want arguments for the partial specialization, not arguments for
7075 the primary template. */
7077 else
7079 }
7081 {
7082 /* This is an argument of the current template, so we haven't set
7083 DECL_CONTEXT yet. */
7084 tree relevant_template_parms;
7086 /* Parameter levels that are greater than the level of the given
7087 template template parm are irrelevant. */
7094 }
7101 complain,
7104 }
7106 /* A cache of template template parameters with match-all default
7107 arguments. */
7109 static void
7111 {
7115 }
7116 static tree
7118 {
7123 }
7125 /* T is a bound template template-parameter. Copy its arguments into default
7126 arguments of the template template-parameter's template parameters. */
7128 static tree
7130 {
7153 {
7156 {
7159 }
7160 }
7164 }
7166 /* ARG is a bound potential template template-argument, and PARGS is a list
7167 of arguments for the corresponding template template-parameter. Adjust
7168 PARGS as appropriate for application to ARG's template, and if ARG is a
7169 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7170 arguments to the template template parameter. */
7172 static tree
7174 {
7178 {
7179 /* When comparing two template template-parameters in partial ordering,
7180 rewrite the one currently being used as an argument to have default
7181 arguments for all parameters. */
7187 }
7188 else
7189 {
7190 tree aparms
7195 }
7198 }
7200 /* Subroutine of unify for the case when PARM is a
7201 BOUND_TEMPLATE_TEMPLATE_PARM. */
7203 static int
7206 {
7210 /* The template template parm might be variadic and the argument
7211 not, so flatten both argument lists. */
7216 {
7217 /* In keeping with P0522R0, adjust P's template arguments
7218 to apply to A's template; then flatten it again. */
7227 /* If the P0522 adjustment eliminated a pack expansion, deduce
7228 empty packs. */
7234 }
7235 else
7236 {
7237 /* Deduce arguments T, i from TT<T> or TT<i>.
7238 We check each element of PARMVEC and ARGVEC individually
7239 rather than the whole TREE_VEC since they can have
7240 different number of elements, which is allowed under N2555. */
7244 /* Check if the parameters end in a pack, making them
7245 variadic. */
7252 /* If the template argument list of P contains a pack
7253 expansion that is not the last template argument, the
7254 entire template argument list is a non-deduced
7255 context. */
7273 DEDUCE_EXACT,
7276 }
7279 }
7281 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7282 template template parameters. Both PARM_PARMS and ARG_PARMS are
7283 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7284 or PARM_DECL.
7286 Consider the example:
7287 template <class T> class A;
7288 template<template <class U> class TT> class B;
7290 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7291 the parameters to A, and OUTER_ARGS contains A. */
7293 static int
7295 tree arg_parms,
7296 tsubst_flags_t complain,
7297 tree in_decl,
7298 tree outer_args)
7299 {
7311 {
7312 /* P0522R0: A template template-parameter P is at least as specialized as
7313 a template template-argument A if, given the following rewrite to two
7314 function templates, the function template corresponding to P is at
7315 least as specialized as the function template corresponding to A
7316 according to the partial ordering rules for function templates
7317 ([temp.func.order]). Given an invented class template X with the
7318 template parameter list of A (including default arguments):
7320 * Each of the two function templates has the same template parameters,
7321 respectively, as P or A.
7323 * Each function template has a single function parameter whose type is
7324 a specialization of X with template arguments corresponding to the
7325 template parameters from the respective function template where, for
7326 each template parameter PP in the template parameter list of the
7327 function template, a corresponding template argument AA is formed. If
7328 PP declares a parameter pack, then AA is the pack expansion
7329 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7331 If the rewrite produces an invalid type, then P is not at least as
7332 specialized as A. */
7334 /* So coerce P's args to apply to A's parms, and then deduce between A's
7335 args and the converted args. If that succeeds, A is at least as
7336 specialized as P, so they match.*/
7343 {
7349 }
7350 }
7352 /* Determine whether we have a parameter pack at the end of the
7353 template template parameter's template parameter list. */
7355 {
7362 {
7376 }
7377 }
7383 /* Check all of the template parameters except the parameter pack at
7384 the end (if any). */
7386 {
7395 outer_args))
7398 }
7401 {
7402 /* Check each of the template parameters in the template
7403 argument against the template parameter pack at the end of
7404 the template template parameter. */
7411 {
7418 outer_args))
7420 }
7421 }
7424 }
7426 /* Verifies that the deduced template arguments (in TARGS) for the
7427 template template parameters (in TPARMS) represent valid bindings,
7428 by comparing the template parameter list of each template argument
7429 to the template parameter list of its corresponding template
7430 template parameter, in accordance with DR150. This
7431 routine can only be called after all template arguments have been
7432 deduced. It will return TRUE if all of the template template
7433 parameter bindings are okay, FALSE otherwise. */
7434 bool
7436 {
7440 /* We're dealing with template parms in this process. */
7446 {
7451 {
7456 {
7457 /* Look inside the argument pack. */
7460 }
7463 {
7467 /* Extract the next argument from the argument
7468 pack. */
7472 /* Look at the pattern of the pack expansion. */
7475 /* Extract the template parameters from the template
7476 argument. */
7482 /* Verify that we can coerce the template template
7483 parameters from the template argument to the template
7484 parameter. This requires an exact match. */
7486 && !coerce_template_template_parms
7488 targ_parms,
7489 tf_none,
7490 tparm,
7491 targs))
7492 {
7495 }
7496 }
7497 }
7498 }
7500 out:
7504 }
7506 /* Since type attributes aren't mangled, we need to strip them from
7507 template type arguments. */
7509 static tree
7511 {
7521 }
7523 /* And from inside dependent non-type arguments like sizeof(Type). */
7525 static tree
7527 {
7537 }
7539 // A template declaration can be substituted for a constrained
7540 // template template parameter only when the argument is more
7541 // constrained than the parameter.
7542 static bool
7544 {
7547 /* For now, allow constrained template template arguments
7548 and unconstrained template template parameters. */
7554 // If the template parameter is constrained, we need to rewrite its
7555 // constraints in terms of the ARG's template parameters. This ensures
7556 // that all of the template parameter types will have the same depth.
7557 //
7558 // Note that this is only valid when coerce_template_template_parm is
7559 // true for the innermost template parameters of PARM and ARG. In other
7560 // words, because coercion is successful, this conversion will be valid.
7562 {
7569 }
7572 }
7574 // Convert a placeholder argument into a binding to the original
7575 // parameter. The original parameter is saved as the TREE_TYPE of
7576 // ARG.
7579 {
7582 }
7584 /* We can't fully resolve ARG given as a non-type template argument to TYPE,
7585 because one of them is dependent. But we need to represent the
7586 conversion for the benefit of cp_tree_equal. */
7588 static tree
7590 {
7591 /* Auto parms get no conversion. */
7594 /* We don't need or want to add this conversion now if we're going to use the
7595 argument for deduction. */
7607 }
7609 /* Convert the indicated template ARG as necessary to match the
7610 indicated template PARM. Returns the converted ARG, or
7611 error_mark_node if the conversion was unsuccessful. Error and
7612 warning messages are issued under control of COMPLAIN. This
7613 conversion is for the Ith parameter in the parameter list. ARGS is
7614 the full set of template arguments deduced so far. */
7616 static tree
7618 tree arg,
7619 tree args,
7620 tsubst_flags_t complain,
7622 tree in_decl)
7623 {
7624 tree orig_arg;
7625 tree val;
7631 /* Trivially convert placeholders. */
7640 {
7641 /* The template argument was the name of some
7642 member function. That's usually
7643 invalid, but static members are OK. In any
7644 case, grab the underlying fields/functions
7645 and issue an error later if required. */
7648 }
7656 /* When determining whether an argument pack expansion is a template,
7657 look at the pattern. */
7661 /* Deal with an injected-class-name used as a template template arg. */
7663 {
7666 {
7676 }
7677 }
7679 is_tmpl_type =
7695 {
7697 {
7701 }
7704 "to refer to a type member of a template parameter, "
7709 typename_type,
7710 complain);
7713 }
7715 {
7717 {
7719 {
7731 else
7734 }
7735 }
7737 }
7739 {
7741 {
7748 else
7751 }
7753 }
7756 /* We already did the appropriate conversion when packing args. */
7759 {
7761 {
7763 /* The number of argument required is not known yet.
7764 Just accept it for now. */
7766 else
7767 {
7769 tree argparm;
7771 /* Strip alias templates that are equivalent to another
7772 template. */
7778 args))
7779 {
7782 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7783 TEMPLATE_DECL. */
7785 {
7790 }
7791 }
7792 else
7793 {
7795 {
7802 }
7805 }
7807 // Check that the constraints are compatible before allowing the
7808 // substitution.
7811 {
7813 {
7819 }
7821 }
7822 }
7823 }
7824 else
7826 /* We only form one instance of each template specialization.
7827 Therefore, if we use a non-canonical variant (i.e., a
7828 typedef), any future messages referring to the type will use
7829 the typedef, which is confusing if those future uses do not
7830 themselves also use the typedef. */
7833 }
7834 else
7835 {
7839 {
7843 }
7844 else
7852 /* We used to call digest_init here. However, digest_init
7853 will report errors, which we don't want when complain
7854 is zero. More importantly, digest_init will try too
7855 hard to convert things: for example, `0' should not be
7856 converted to pointer type at this point according to
7857 the standard. Accepting this is not merely an
7858 extension, since deciding whether or not these
7859 conversions can occur is part of determining which
7860 function template to call, or whether a given explicit
7861 argument specification is valid. */
7863 else
7864 {
7867 }
7877 {
7878 /* Reject template arguments that are references to built-in
7879 functions with no library fallbacks. */
7888 }
7891 {
7892 /* Strip typedefs from the SCOPE_REF. */
7895 complain);
7898 }
7899 }
7902 }
7904 /* Coerces the remaining template arguments in INNER_ARGS (from
7905 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7906 Returns the coerced argument pack. PARM_IDX is the position of this
7907 parameter in the template parameter list. ARGS is the original
7908 template argument list. */
7909 static tree
7912 tree args,
7913 tree inner_args,
7915 tree new_args,
7917 tree in_decl,
7918 tsubst_flags_t complain)
7919 {
7922 tree packed_args;
7923 tree argument_pack;
7930 {
7931 /* When the template parameter is a non-type template parameter pack
7932 or template template parameter pack whose type or template
7933 parameters use parameter packs, we know exactly how many arguments
7934 we are looking for. Build a vector of the instantiated decls for
7935 these template parameters in PACKED_PARMS. */
7936 /* We can't use make_pack_expansion here because it would interpret a
7937 _DECL as a use rather than a declaration. */
7951 /* If we're doing a partial instantiation of a member template,
7952 verify that all of the types used for the non-type
7953 template parameter pack are, in fact, valid for non-type
7954 template parameters. */
7957 {
7960 {
7964 }
7965 /* We don't know how many args we have yet, just
7966 use the unconverted ones for now. */
7968 }
7971 }
7972 /* Check if we have a placeholder pack, which indicates we're
7973 in the context of a introduction list. In that case we want
7974 to match this pack to the single placeholder. */
7978 {
7981 }
7982 else
7985 /* Convert the remaining arguments, which will be a part of the
7986 parameter pack "parm". */
7989 {
7995 {
7996 /* Once we've packed as many args as we have types, stop. */
8000 /* We don't know how many args we have yet, just
8001 use the unconverted ones for now. */
8003 else
8005 }
8008 {
8011 }
8012 else
8015 in_decl);
8019 }
8023 {
8028 }
8033 else
8034 {
8037 }
8044 }
8046 /* Returns the number of pack expansions in the template argument vector
8047 ARGS. */
8049 static int
8051 {
8056 {
8060 }
8062 }
8064 /* Convert all template arguments to their appropriate types, and
8065 return a vector containing the innermost resulting template
8066 arguments. If any error occurs, return error_mark_node. Error and
8067 warning messages are issued under control of COMPLAIN.
8069 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
8070 for arguments not specified in ARGS. Otherwise, if
8071 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8072 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8073 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8074 ARGS. */
8076 static tree
8078 tree args,
8079 tree in_decl,
8080 tsubst_flags_t complain,
8083 {
8085 tree orig_inner_args;
8086 tree inner_args;
8087 tree new_args;
8088 tree new_inner_args;
8092 /* When used as a boolean value, indicates whether this is a
8093 variadic template parameter list. Since it's an int, we can also
8094 subtract it from nparms to get the number of non-variadic
8095 parameters. */
8100 /* Likewise for parameters with default arguments. */
8108 /* Determine if there are any parameter packs or default arguments. */
8110 {
8118 }
8121 /* If there are no parameters that follow a parameter pack, we need to
8122 expand any argument packs so that we can deduce a parameter pack from
8123 some non-packed args followed by an argument pack, as in variadic85.C.
8124 If there are such parameters, we need to leave argument packs intact
8125 so the arguments are assigned properly. This can happen when dealing
8126 with a nested class inside a partial specialization of a class
8127 template, as in variadic92.C, or when deducing a template parameter pack
8128 from a sub-declarator, as in variadic114.C. */
8132 /* Count any pack expansion args. */
8138 && require_all_args
8139 && !variadic_args_p
8140 && (!use_default_args
8143 {
8145 {
8147 {
8151 }
8152 else
8159 }
8162 }
8163 /* We can't pass a pack expansion to a non-pack parameter of an alias
8164 template (DR 1430). */
8168 && variadic_args_p
8170 {
8172 {
8174 {
8180 {
8183 "pack expansion argument for non-pack parameter "
8185 else
8187 "pack expansion argument for non-pack parameter "
8191 }
8192 }
8194 found:;
8195 }
8197 }
8199 /* We need to evaluate the template arguments, even though this
8200 template-id may be nested within a "sizeof". */
8209 {
8210 tree arg;
8211 tree parm;
8213 /* Get the Ith template parameter. */
8217 {
8220 }
8222 /* Calculate the next argument. */
8225 else
8230 {
8231 /* Some arguments will be placed in the
8232 template parameter pack PARM. */
8239 {
8240 /* We don't know how many args we have yet, just use the
8241 unconverted (and still packed) ones for now. */
8245 }
8249 /* Store this argument. */
8251 {
8252 lost++;
8253 /* We are done with all of the arguments. */
8255 }
8256 else
8257 {
8260 }
8263 }
8265 {
8267 {
8268 /* "If every valid specialization of a variadic template
8269 requires an empty template parameter pack, the template is
8270 ill-formed, no diagnostic required." So check that the
8271 pattern works with this parameter. */
8276 in_decl);
8278 {
8283 }
8285 /* Recover from missing typename. */
8289 /* We don't know how many args we have yet, just
8290 use the unconverted ones for now. */
8294 }
8295 }
8297 {
8298 /* There must be a default arg in this case. */
8301 /* The position of the first default template argument,
8302 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8303 Record that. */
8307 }
8308 else
8312 {
8315 }
8317 /* This only occurs if there was an error in the template
8318 parameter list itself (which we would already have
8319 reported) that we are trying to recover from, e.g., a class
8320 template with a parameter list such as
8321 template<typename..., typename>. */
8323 else
8329 lost++;
8331 }
8336 {
8338 {
8343 }
8345 }
8355 }
8357 /* Convert all template arguments to their appropriate types, and
8358 return a vector containing the innermost resulting template
8359 arguments. If any error occurs, return error_mark_node. Error and
8360 warning messages are not issued.
8362 Note that no function argument deduction is performed, and default
8363 arguments are used to fill in unspecified arguments. */
8364 tree
8366 {
8368 }
8370 /* Convert all template arguments to their appropriate type, and
8371 instantiate default arguments as needed. This returns a vector
8372 containing the innermost resulting template arguments, or
8373 error_mark_node if unsuccessful. */
8374 tree
8376 tsubst_flags_t complain)
8377 {
8379 }
8381 /* Like coerce_template_parms. If PARMS represents all template
8382 parameters levels, this function returns a vector of vectors
8383 representing all the resulting argument levels. Note that in this
8384 case, only the innermost arguments are coerced because the
8385 outermost ones are supposed to have been coerced already.
8387 Otherwise, if PARMS represents only (the innermost) vector of
8388 parameters, this function returns a vector containing just the
8389 innermost resulting arguments. */
8391 static tree
8393 tree args,
8394 tree in_decl,
8395 tsubst_flags_t complain,
8398 {
8401 tree coerced_args;
8404 {
8406 tree level;
8412 {
8413 tree l;
8417 require_all_args,
8418 use_default_args);
8419 else
8426 }
8427 }
8428 else
8431 require_all_args,
8432 use_default_args);
8434 }
8436 /* Returns 1 if template args OT and NT are equivalent. */
8438 int
8440 {
8449 /* For member templates */
8458 {
8475 }
8479 {
8482 /* Don't treat an alias template specialization with dependent
8483 arguments as equivalent to its underlying type when used as a
8484 template argument; we need them to be distinct so that we
8485 substitute into the specialization arguments at instantiation
8486 time. And aliases can't be equivalent without being ==, so
8487 we don't need to look any deeper.
8489 During partial ordering, however, we need to treat them normally so
8490 that we can order uses of the same alias with different
8491 cv-qualification (79960). */
8495 else
8497 }
8500 else
8501 {
8502 /* Try to treat a template non-type argument that has been converted
8503 to the parameter type as equivalent to one that hasn't yet. */
8516 }
8517 }
8519 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8520 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8521 NEWARG_PTR with the offending arguments if they are non-NULL. */
8523 int
8527 {
8540 {
8545 {
8551 }
8552 }
8554 }
8558 {
8560 }
8562 static void
8564 {
8574 /* We are called both from instantiate_decl, where we've already had a
8575 tinst_level pushed, and instantiate_template, where we haven't.
8576 Compensate. */
8587 else
8596 }
8599 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8600 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8601 documentation for TEMPLATE_ID_EXPR. */
8603 tree
8605 {
8606 tree type;
8614 {
8617 }
8620 {
8622 unknown_type_node,
8624 arglist);
8626 }
8633 }
8635 /* Within the scope of a template class S<T>, the name S gets bound
8636 (in build_self_reference) to a TYPE_DECL for the class, not a
8637 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8638 or one of its enclosing classes, and that type is a template,
8639 return the associated TEMPLATE_DECL. Otherwise, the original
8640 DECL is returned.
8642 Also handle the case when DECL is a TREE_LIST of ambiguous
8643 injected-class-names from different bases. */
8645 tree
8647 {
8651 /* DR 176: A lookup that finds an injected-class-name (10.2
8652 [class.member.lookup]) can result in an ambiguity in certain cases
8653 (for example, if it is found in more than one base class). If all of
8654 the injected-class-names that are found refer to specializations of
8655 the same class template, and if the name is followed by a
8656 template-argument-list, the reference refers to the class template
8657 itself and not a specialization thereof, and is not ambiguous. */
8659 {
8662 {
8668 }
8671 else
8673 }
8679 }
8681 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8682 parameters, find the desired type.
8684 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8686 IN_DECL, if non-NULL, is the template declaration we are trying to
8687 instantiate.
8689 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8690 the class we are looking up.
8692 Issue error and warning messages under control of COMPLAIN.
8694 If the template class is really a local class in a template
8695 function, then the FUNCTION_CONTEXT is the function in which it is
8696 being instantiated.
8698 ??? Note that this function is currently called *twice* for each
8699 template-id: the first time from the parser, while creating the
8700 incomplete type (finish_template_type), and the second type during the
8701 real instantiation (instantiate_template_class). This is surely something
8702 that we want to avoid. It also causes some problems with argument
8703 coercion (see convert_nontype_argument for more information on this). */
8705 static tree
8708 {
8710 tree t;
8713 spec_entry elt;
8714 hashval_t hash;
8717 {
8721 else
8722 {
8729 }
8732 }
8734 {
8737 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8738 an implicit typename for the second A. Deal with it. */
8743 {
8746 }
8747 }
8750 {
8753 }
8755 {
8759 }
8761 {
8764 }
8766 /* Issue an error message if we didn't find a template. */
8768 {
8772 }
8775 /* Make sure it's a user visible template, if it was named by
8776 the user. */
8779 {
8781 {
8785 }
8787 }
8791 /* An alias that just changes the name of a template is equivalent to the
8792 other template, so if any of the arguments are pack expansions, strip
8793 the alias to avoid problems with a pack expansion passed to a non-pack
8794 alias template parameter (DR 1430). */
8799 {
8800 tree parm;
8809 }
8810 else
8811 {
8813 tree gen_tmpl;
8814 tree type_decl;
8822 /* An error occurred while building the template TEMPL, and a
8823 diagnostic has most certainly been emitted for that
8824 already. Let's propagate that error. */
8833 {
8834 /* We've been given an incomplete set of template arguments.
8835 For example, given:
8837 template <class T> struct S1 {
8838 template <class U> struct S2 {};
8839 template <class U> struct S2<U*> {};
8840 };
8842 we will be called with an ARGLIST of `U*', but the
8843 TEMPLATE will be `template <class T> template
8844 <class U> struct S1<T>::S2'. We must fill in the missing
8845 arguments. */
8849 }
8851 /* Now we should have enough arguments. */
8854 /* From here on, we're only interested in the most general
8855 template. */
8857 /* Calculate the BOUND_ARGS. These will be the args that are
8858 actually tsubst'd into the definition to create the
8859 instantiation. */
8861 complain,
8866 /* We were unable to bind the arguments. */
8869 /* In the scope of a template class, explicit references to the
8870 template class refer to the type of the template, not any
8871 instantiation of it. For example, in:
8873 template <class T> class C { void f(C<T>); }
8875 the `C<T>' is just the same as `C'. Outside of the
8876 class, however, such a reference is an instantiation. */
8880 {
8885 }
8887 /* If we already have this specialization, return it. */
8897 /* If the the template's constraints are not satisfied,
8898 then we cannot form a valid type.
8900 Note that the check is deferred until after the hash
8901 lookup. This prevents redundant checks on previously
8902 instantiated specializations. */
8904 {
8906 {
8909 }
8911 }
8915 /* If the deduced arguments are invalid, then the binding
8916 failed. */
8920 complain))
8927 {
8932 }
8942 /* Create the type. */
8944 {
8945 /* The user referred to a specialization of an alias
8946 template represented by GEN_TMPL.
8948 [temp.alias]/2 says:
8950 When a template-id refers to the specialization of an
8951 alias template, it is equivalent to the associated
8952 type obtained by substitution of its
8953 template-arguments for the template-parameters in the
8954 type-id of the alias template. */
8957 /* Note that the call above (by indirectly calling
8958 register_specialization in tsubst_decl) registers the
8959 TYPE_DECL representing the specialization of the alias
8960 template. So next time someone substitutes ARGLIST for
8961 the template parms into the alias template (GEN_TMPL),
8962 she'll get that TYPE_DECL back. */
8966 }
8968 {
8970 {
8981 }
8982 else
8983 {
8984 /* We don't want to call start_enum for this type, since
8985 the values for the enumeration constants may involve
8986 template parameters. And, no one should be interested
8987 in the enumeration constants for such a type. */
8990 }
8994 }
8996 {
8997 /* Lambda closures are regenerated in tsubst_lambda_expr, not
8998 instantiated here. */
9006 /* A local class. Make sure the decl gets registered properly. */
9011 /* This instantiation is another name for the primary
9012 template type. Set the TYPE_CANONICAL field
9013 appropriately. */
9016 /* Some of the template arguments require structural
9017 equality testing, so this template class requires
9018 structural equality testing. */
9020 }
9021 else
9024 /* If we called start_enum or pushtag above, this information
9025 will already be set up. */
9027 {
9034 }
9035 else
9039 {
9045 {
9048 }
9049 }
9053 {
9057 {
9058 tree attributes
9066 }
9067 }
9069 /* Let's consider the explicit specialization of a member
9070 of a class template specialization that is implicitly instantiated,
9071 e.g.:
9072 template<class T>
9073 struct S
9074 {
9075 template<class U> struct M {}; //#0
9076 };
9078 template<>
9079 template<>
9080 struct S<int>::M<char> //#1
9081 {
9082 int i;
9083 };
9084 [temp.expl.spec]/4 says this is valid.
9086 In this case, when we write:
9087 S<int>::M<char> m;
9089 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9090 the one of #0.
9092 When we encounter #1, we want to store the partial instantiation
9093 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9095 For all cases other than this "explicit specialization of member of a
9096 class template", we just want to store the most general template into
9097 the CLASSTYPE_TI_TEMPLATE of M.
9099 This case of "explicit specialization of member of a class template"
9100 only happens when:
9101 1/ the enclosing class is an instantiation of, and therefore not
9102 the same as, the context of the most general template, and
9103 2/ we aren't looking at the partial instantiation itself, i.e.
9104 the innermost arguments are not the same as the innermost parms of
9105 the most general template.
9107 So it's only when 1/ and 2/ happens that we want to use the partial
9108 instantiation of the member template in lieu of its most general
9109 template. */
9113 /* the enclosing class must be an instantiation... */
9116 {
9120 tree partial_inst_args =
9127 use_partial_inst_tmpl =
9128 /*...and we must not be looking at the partial instantiation
9129 itself. */
9131 partial_inst_args);
9132 }
9135 /* This case is easy; there are no member templates involved. */
9137 else
9138 {
9139 /* This is a full instantiation of a member template. Find
9140 the partial instantiation of which this is an instance. */
9142 /* Temporarily reduce by one the number of levels in the ARGLIST
9143 so as to avoid comparing the last set of arguments. */
9147 /* FOUND is either a proper class type, or an alias
9148 template specialization. In the later case, it's a
9149 TYPE_DECL, resulting from the substituting of arguments
9150 for parameters in the TYPE_DECL of the alias template
9151 done earlier. So be careful while getting the template
9152 of FOUND. */
9154 ? found
9158 }
9160 // Build template info for the new specialization.
9169 /* Note this use of the partial instantiation so we can check it
9170 later in maybe_process_partial_specialization. */
9177 /* Now that the type has been registered on the instantiations
9178 list, we set up the enumerators. Because the enumeration
9179 constants may involve the enumeration type itself, we make
9180 sure to register the type first, and then create the
9181 constants. That way, doing tsubst_expr for the enumeration
9182 constants won't result in recursive calls here; we'll find
9183 the instantiation and exit above. */
9187 /* If the type makes use of template parameters, the
9188 code that generates debugging information will crash. */
9191 /* Possibly limit visibility based on template args. */
9198 }
9199 }
9201 /* Wrapper for lookup_template_class_1. */
9203 tree
9206 {
9207 tree ret;
9213 }
9215 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9217 tree
9219 {
9220 /* The type of the expression is NULL_TREE since the template-id could refer
9221 to an explicit or partial specialization. */
9224 /* Except that concepts are always bool. */
9227 }
9229 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9231 tree
9233 {
9237 /* We never want to return a VAR_DECL for a variable concept, since they
9238 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9253 {
9255 {
9258 }
9260 }
9262 /* If a template-id refers to a specialization of a variable
9263 concept, then the expression is true if and only if the
9264 concept's constraints are satisfied by the given template
9265 arguments.
9267 NOTE: This is an extension of Concepts Lite TS that
9268 allows constraints to be used in expressions. */
9270 {
9273 }
9276 }
9278 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9279 TARGS template args, and instantiate it if it's not dependent. */
9281 tree
9283 tsubst_flags_t complain)
9284 {
9287 {
9290 }
9293 }
9295 \f
9296 struct pair_fn_data
9297 {
9298 tree_fn_t fn;
9299 tree_fn_t any_fn;
9301 /* True when we should also visit template parameters that occur in
9302 non-deduced contexts. */
9305 };
9307 /* Called from for_each_template_parm via walk_tree. */
9309 static tree
9311 {
9318 #define WALK_SUBTREE(NODE) \
9319 do \
9320 { \
9321 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9322 pfd->include_nondeduced_p, \
9323 pfd->any_fn); \
9324 if (result) goto out; \
9325 } \
9326 while (0)
9336 {
9340 /* Fall through. */
9346 else
9356 /* Since we're not going to walk subtrees, we have to do this
9357 explicitly here. */
9359 /* Fall through. */
9362 /* Check the return type. */
9365 /* Check the parameter types. Since default arguments are not
9366 instantiated until they are needed, the TYPE_ARG_TYPES may
9367 contain expressions that involve template parameters. But,
9368 no-one should be looking at them yet. And, once they're
9369 instantiated, they don't contain template parameters, so
9370 there's no point in looking at them then, either. */
9371 {
9372 tree parm;
9377 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9378 want walk_tree walking into them itself. */
9380 }
9383 {
9387 }
9404 /* Fall through. */
9416 /* Record template parameters such as `T' inside `TT<T>'. */
9418 /* Fall through. */
9430 /* A template template parameter is encountered. */
9434 /* Already substituted template template parameter */
9439 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9440 partial instantiation. */
9452 /* If there's no type, then this thing must be some expression
9453 involving template parameters. */
9475 }
9477 #undef WALK_SUBTREE
9479 /* We didn't find any template parameters we liked. */
9480 out:
9482 }
9484 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9485 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9486 call FN with the parameter and the DATA.
9487 If FN returns nonzero, the iteration is terminated, and
9488 for_each_template_parm returns 1. Otherwise, the iteration
9489 continues. If FN never returns a nonzero value, the value
9490 returned by for_each_template_parm is 0. If FN is NULL, it is
9491 considered to be the function which always returns 1.
9493 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9494 parameters that occur in non-deduced contexts. When false, only
9495 visits those template parameters that can be deduced. */
9497 static tree
9501 tree_fn_t any_fn)
9502 {
9504 tree result;
9506 /* Set up. */
9512 /* Walk the tree. (Conceptually, we would like to walk without
9513 duplicates, but for_each_template_parm_r recursively calls
9514 for_each_template_parm, so we would need to reorganize a fair
9515 bit to use walk_tree_without_duplicates, so we keep our own
9516 visited list.) */
9519 else
9522 for_each_template_parm_r,
9526 /* Clean up. */
9528 {
9531 }
9534 }
9536 /* Returns true if T depends on any template parameter. */
9538 int
9540 {
9570 else
9571 {
9574 }
9579 }
9581 /* Returns true iff current_function_decl is an incompletely instantiated
9582 template. Useful instead of processing_template_decl because the latter
9583 is set to 0 during instantiate_non_dependent_expr. */
9585 bool
9587 {
9596 }
9598 /* Returns true if T depends on any template parameter with level LEVEL. */
9600 bool
9602 {
9605 }
9607 /* Returns true if the signature of DECL depends on any template parameter from
9608 its enclosing class. */
9610 bool
9612 {
9622 template_parm_outer_level,
9632 }
9634 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9635 ill-formed translation unit, i.e. a variable or function that isn't
9636 usable in a constant expression. */
9640 {
9645 }
9647 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9648 neglectable and instantiated from within an erroneous instantiation. */
9650 static bool
9652 {
9663 }
9671 /* We're starting to instantiate D; record the template instantiation context
9672 for diagnostics and to restore it later. */
9674 bool
9676 {
9678 }
9680 /* We're starting to instantiate D; record the template instantiation context
9681 at LOC for diagnostics and to restore it later. */
9683 bool
9685 {
9689 {
9690 /* Tell error.c not to try to instantiate any templates. */
9693 "template instantiation depth exceeds maximum of %d"
9695 max_tinst_depth);
9697 }
9699 /* If the current instantiation caused problems, don't let it instantiate
9700 anything else. Do allow deduction substitution and decls usable in
9701 constant expressions. */
9705 /* When not -quiet, dump template instantiations other than functions, since
9706 announce_function will take care of those. */
9725 }
9727 /* We're done instantiating this template; return to the instantiation
9728 context. */
9730 void
9732 {
9733 /* Restore the filename and line number stashed away when we started
9734 this instantiation. */
9738 }
9740 /* We're instantiating a deferred template; restore the template
9741 instantiation context in which the instantiation was requested, which
9742 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9744 static tree
9746 {
9758 }
9760 /* Returns the TINST_LEVEL which gives the original instantiation
9761 context. */
9765 {
9771 }
9773 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9774 vector of template arguments, as for tsubst.
9776 Returns an appropriate tsubst'd friend declaration. */
9778 static tree
9780 {
9781 tree new_friend;
9786 /* This was a friend declared with an explicit template
9787 argument list, e.g.:
9789 friend void f<>(T);
9791 to indicate that f was a template instantiation, not a new
9792 function declaration. Now, we have to figure out what
9793 instantiation of what template. */
9794 {
9796 tree new_args;
9797 tree tmpl;
9800 /* Friend functions are looked up in the containing namespace scope.
9801 We must enter that scope, to avoid finding member functions of the
9802 current class with same name. */
9817 tsk_none);
9819 }
9823 /* The NEW_FRIEND will look like an instantiation, to the
9824 compiler, but is not an instantiation from the point of view of
9825 the language. For example, we might have had:
9827 template <class T> struct S {
9828 template <class U> friend void f(T, U);
9829 };
9831 Then, in S<int>, template <class U> void f(int, U) is not an
9832 instantiation of anything. */
9838 {
9842 }
9844 /* The mangled name for the NEW_FRIEND is incorrect. The function
9845 is not a template instantiation and should not be mangled like
9846 one. Therefore, we forget the mangling here; we'll recompute it
9847 later if we need it. */
9849 {
9852 }
9855 {
9856 tree old_decl;
9857 tree new_friend_template_info;
9858 tree new_friend_result_template_info;
9859 tree ns;
9862 /* We must save some information from NEW_FRIEND before calling
9863 duplicate decls since that function will free NEW_FRIEND if
9864 possible. */
9866 new_friend_is_defn =
9871 {
9872 /* This declaration is a `primary' template. */
9875 new_friend_result_template_info
9877 }
9878 else
9881 /* Inside pushdecl_namespace_level, we will push into the
9882 current namespace. However, the friend function should go
9883 into the namespace of the template. */
9893 {
9894 /* This new friend declaration matched an existing
9895 declaration. For example, given:
9897 template <class T> void f(T);
9898 template <class U> class C {
9899 template <class T> friend void f(T) {}
9900 };
9902 the friend declaration actually provides the definition
9903 of `f', once C has been instantiated for some type. So,
9904 old_decl will be the out-of-class template declaration,
9905 while new_friend is the in-class definition.
9907 But, if `f' was called before this point, the
9908 instantiation of `f' will have DECL_TI_ARGS corresponding
9909 to `T' but not to `U', references to which might appear
9910 in the definition of `f'. Previously, the most general
9911 template for an instantiation of `f' was the out-of-class
9912 version; now it is the in-class version. Therefore, we
9913 run through all specialization of `f', adding to their
9914 DECL_TI_ARGS appropriately. In particular, they need a
9915 new set of outer arguments, corresponding to the
9916 arguments for this class instantiation.
9918 The same situation can arise with something like this:
9920 friend void f(int);
9921 template <class T> class C {
9922 friend void f(T) {}
9923 };
9925 when `C<int>' is instantiated. Now, `f(int)' is defined
9926 in the class. */
9929 /* On the other hand, if the in-class declaration does
9930 *not* provide a definition, then we don't want to alter
9931 existing definitions. We can just leave everything
9932 alone. */
9933 ;
9934 else
9935 {
9939 /* Overwrite whatever template info was there before, if
9940 any, with the new template information pertaining to
9941 the declaration. */
9945 {
9946 /* We should have called reregister_specialization in
9947 duplicate_decls. */
9952 /* Instantiate it if the global has already been used. */
9956 }
9957 else
9958 {
9959 tree t;
9961 /* Indicate that the old function template is a partial
9962 instantiation. */
9970 /* Reassign any specializations already in the hash table
9971 to the new more general template, and add the
9972 additional template args. */
9976 {
9978 spec_entry elt;
9990 register_specialization
9993 }
9995 }
9996 }
9998 /* The information from NEW_FRIEND has been merged into OLD_DECL
9999 by duplicate_decls. */
10001 }
10002 }
10003 else
10004 {
10008 /* In the code
10009 template <class T> class C {
10010 template <class U> friend void C1<U>::f (); // case 1
10011 friend void C2<T>::f (); // case 2
10012 };
10013 we only need to make sure CONTEXT is a complete type for
10014 case 2. To distinguish between the two cases, we note that
10015 CONTEXT of case 1 remains dependent type after tsubst while
10016 this isn't true for case 2. */
10026 {
10028 /* do_friend adds the TEMPLATE_DECL for any member friend
10029 template even if it isn't a member template, i.e.
10030 template <class T> friend A<T>::f();
10031 Look through it in that case. */
10035 /* Check to see that the declaration is really present, and,
10036 possibly obtain an improved declaration. */
10041 }
10042 }
10045 }
10047 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
10048 template arguments, as for tsubst.
10050 Returns an appropriate tsubst'd friend type or error_mark_node on
10051 failure. */
10053 static tree
10055 {
10056 tree tmpl;
10059 {
10062 }
10067 else
10075 {
10076 /* The friend template has already been declared. Just
10077 check to see that the declarations match, and install any new
10078 default parameters. We must tsubst the default parameters,
10079 of course. We only need the innermost template parameters
10080 because that is all that redeclare_class_template will look
10081 at. */
10084 {
10092 }
10093 }
10094 else
10095 {
10096 /* The friend template has not already been declared. In this
10097 case, the instantiation of the template class will cause the
10098 injection of this template into the namespace scope. */
10102 {
10103 /* The new TMPL is not an instantiation of anything, so we
10104 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
10105 for the new type because that is supposed to be the
10106 corresponding template decl, i.e., TMPL. */
10113 /* It is hidden. */
10118 /* Inject this template into the enclosing namspace scope. */
10120 }
10121 }
10125 else
10129 }
10131 /* Returns zero if TYPE cannot be completed later due to circularity.
10132 Otherwise returns one. */
10134 static int
10136 {
10146 else
10148 }
10153 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10154 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10156 static tree
10159 {
10168 {
10175 clauses
10179 else
10181 }
10182 /* If the first attribute argument is an identifier, don't
10183 pass it through tsubst. Attributes like mode, format,
10184 cleanup and several target specific attributes expect it
10185 unmodified. */
10187 {
10188 tree chain
10193 }
10195 {
10196 /* An attribute pack expansion. */
10205 {
10209 }
10211 }
10212 else
10219 }
10221 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10222 unchanged or a new TREE_LIST chain. */
10224 static tree
10227 {
10232 {
10236 }
10240 {
10243 {
10246 {
10248 do
10253 }
10254 }
10256 }
10259 }
10261 /* Apply any attributes which had to be deferred until instantiation
10262 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10263 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10265 static void
10268 {
10270 tree t;
10277 {
10281 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10282 to our attributes parameter. */
10284 }
10285 else
10286 {
10288 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10289 lookup_template_class_1, and should be preserved. */
10293 }
10297 {
10301 }
10305 {
10310 {
10313 {
10317 do
10320 }
10321 else
10323 }
10326 }
10327 }
10329 /* Perform (or defer) access check for typedefs that were referenced
10330 from within the template TMPL code.
10331 This is a subroutine of instantiate_decl and instantiate_class_template.
10332 TMPL is the template to consider and TARGS is the list of arguments of
10333 that template. */
10335 static void
10337 {
10338 location_t saved_location;
10349 {
10361 /* Make access check error messages point to the location
10362 of the use of the typedef. */
10366 tf_warning_or_error);
10367 }
10369 }
10371 static tree
10373 {
10375 tree typedecl;
10376 tree pbinfo;
10377 tree base_list;
10379 tree fn_context;
10388 /* Figure out which template is being instantiated. */
10392 /* Mark the type as in the process of being defined. */
10395 /* Determine what specialization of the original template to
10396 instantiate. */
10401 {
10402 /* This TYPE is actually an instantiation of a partial
10403 specialization. We replace the innermost set of ARGS with
10404 the arguments appropriate for substitution. For example,
10405 given:
10407 template <class T> struct S {};
10408 template <class T> struct S<T*> {};
10410 and supposing that we are instantiating S<int*>, ARGS will
10411 presently be {int*} -- but we need {int}. */
10414 }
10415 else
10416 {
10419 }
10421 /* If the template we're instantiating is incomplete, then clearly
10422 there's nothing we can do. */
10424 {
10425 /* We can try again later. */
10428 }
10430 /* If we've recursively instantiated too many templates, stop. */
10434 /* We may be in the middle of deferred access check. Disable
10435 it now. */
10442 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10447 else
10448 {
10451 }
10452 /* Use #pragma pack from the template context. */
10458 /* Set the input location to the most specialized template definition.
10459 This is needed if tsubsting causes an error. */
10471 {
10474 /* Adjust visibility for template arguments. */
10476 }
10482 /* We should never instantiate a nested class before its enclosing
10483 class; we need to look up the nested class by name before we can
10484 instantiate it, and that lookup should instantiate the enclosing
10485 class. */
10491 {
10492 tree pbase_binfo;
10493 tree pushed_scope;
10496 /* We must enter the scope containing the type, as that is where
10497 the accessibility of types named in dependent bases are
10498 looked up from. */
10501 /* Substitute into each of the bases to determine the actual
10502 basetypes. */
10504 {
10505 tree base;
10511 {
10512 expanded_bases =
10519 }
10522 {
10524 /* Extract the already-expanded base class. */
10526 else
10527 /* Substitute to figure out the base class. */
10529 NULL_TREE);
10537 }
10538 }
10540 /* The list is now in reverse order; correct that. */
10545 }
10546 /* Now call xref_basetypes to set up all the base-class
10547 information. */
10555 /* Now that our base classes are set up, enter the scope of the
10556 class, so that name lookups into base classes, etc. will work
10557 correctly. This is precisely analogous to what we do in
10558 begin_class_definition when defining an ordinary non-template
10559 class, except we also need to push the enclosing classes. */
10562 /* Now members are processed in the order of declaration. */
10565 {
10569 {
10571 {
10573 /* A closure type for a lambda in an NSDMI or default argument.
10574 Ignore it; it will be regenerated when needed. */
10577 /* Build new CLASSTYPE_NESTED_UTDS. */
10579 tree newtag;
10585 /* If the member is a class template, then -- even after
10586 substitution -- there may be dependent types in the
10587 template argument list for the class. We increment
10588 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10589 that function will assume that no types are dependent
10590 when outside of a template. */
10600 {
10604 /* Unfortunately, lookup_template_class sets
10605 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10606 instantiation (i.e., for the type of a member
10607 template class nested within a template class.)
10608 This behavior is required for
10609 maybe_process_partial_specialization to work
10610 correctly, but is not accurate in this case;
10611 the TAG is not an instantiation of anything.
10612 (The corresponding TEMPLATE_DECL is an
10613 instantiation, but the TYPE is not.) */
10616 /* Now, we call pushtag to put this NEWTAG into the scope of
10617 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10618 pushtag calling push_template_decl. We don't have to do
10619 this for enums because it will already have been done in
10620 tsubst_enum. */
10624 }
10625 }
10627 {
10628 tree r;
10637 /* Instantiate members marked with attribute used. */
10643 }
10646 /* A closure type for a lambda in an NSDMI or default argument.
10648 else
10649 {
10650 /* Build new TYPE_FIELDS. */
10652 {
10653 tree condition;
10656 condition =
10666 }
10668 {
10669 tree r;
10673 /* The file and line for this declaration, to
10674 assist in error message reporting. Since we
10675 called push_tinst_level above, we don't need to
10676 restore these. */
10686 {
10687 /* A capture pack became multiple fields. */
10690 }
10693 {
10697 {
10698 /* In [temp.inst]:
10700 [t]he initialization (and any associated
10701 side-effects) of a static data member does
10702 not occur unless the static data member is
10703 itself used in a way that requires the
10704 definition of the static data member to
10705 exist.
10707 Therefore, we do not substitute into the
10708 initialized for the static data member here. */
10709 finish_static_data_member_decl
10715 /* Instantiate members marked with attribute used. */
10718 }
10720 {
10721 /* Determine whether R has a valid type and can be
10722 completed later. If R is invalid, then its type
10723 is replaced by error_mark_node. */
10729 {
10730 /* If R's type couldn't be completed and
10731 it isn't a flexible array member (whose
10732 type is incomplete by definition) give
10733 an error. */
10736 }
10737 }
10739 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10740 such a thing will already have been added to the field
10741 list by tsubst_enum in finish_member_declaration in the
10742 CLASSTYPE_NESTED_UTDS case above. */
10746 {
10749 }
10750 }
10751 }
10752 }
10753 }
10754 else
10755 {
10758 {
10759 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10765 {
10766 /* template <class T> friend class C; */
10769 }
10771 {
10772 /* template <class T> friend class C::D; */
10778 }
10781 {
10782 /* This could be either
10784 friend class T::C;
10786 when dependent_type_p is false or
10788 template <class U> friend class T::C;
10790 otherwise. */
10791 /* Bump processing_template_decl in case this is something like
10792 template <class T> friend struct A<T>::B. */
10799 }
10803 {
10804 /* friend class C;
10806 where C hasn't been declared yet. Let's lookup name
10807 from namespace scope directly, bypassing any name that
10808 come from dependent base class. */
10811 /* The call to xref_tag_from_type does injection for friend
10812 classes. */
10814 friend_type =
10818 }
10820 /* friend class C<T>; */
10823 /* Otherwise it's
10825 friend class C;
10827 where C is already declared or
10829 friend class C<int>;
10831 We don't have to do anything in these cases. */
10834 /* Trick make_friend_class into realizing that the friend
10835 we're adding is a template, not an ordinary class. It's
10836 important that we use make_friend_class since it will
10837 perform some error-checking and output cross-reference
10838 information. */
10846 }
10847 else
10848 {
10849 /* Build new DECL_FRIENDLIST. */
10850 tree r;
10852 /* The file and line for this declaration, to
10853 assist in error message reporting. Since we
10854 called push_tinst_level above, we don't need to
10855 restore these. */
10859 {
10862 }
10867 {
10870 }
10871 }
10872 }
10873 }
10876 {
10877 /* Restore these before substituting into the lambda capture
10878 initializers. */
10881 }
10883 /* Set the file and line number information to whatever is given for
10884 the class itself. This puts error messages involving generated
10885 implicit functions at a predictable point, and the same point
10886 that would be used for non-template classes. */
10893 /* We don't instantiate default arguments for member functions. 14.7.1:
10895 The implicit instantiation of a class template specialization causes
10896 the implicit instantiation of the declarations, but not of the
10897 definitions or default arguments, of the class member functions,
10898 member classes, static data members and member templates.... */
10900 /* Some typedefs referenced from within the template code need to be access
10901 checked at template instantiation time, i.e now. These types were
10902 added to the template at parsing time. Let's get those and perform
10903 the access checks then. */
10913 /* The vtable for a template class can be emitted in any translation
10914 unit in which the class is instantiated. When there is no key
10915 method, however, finish_struct_1 will already have added TYPE to
10916 the keyed_classes. */
10921 }
10923 /* Wrapper for instantiate_class_template_1. */
10925 tree
10927 {
10928 tree ret;
10933 }
10935 static tree
10937 {
10938 tree r;
10944 else
10945 {
10952 }
10954 }
10956 /* Given a function parameter pack TMPL_PARM and some function parameters
10957 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10958 and set *SPEC_P to point at the next point in the list. */
10960 tree
10962 {
10963 /* Collect all of the extra "packed" parameters into an
10964 argument pack. */
10965 tree parmvec;
10975 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10979 {
10984 }
10986 /* Build the argument packs. */
10991 }
10993 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10994 NONTYPE_ARGUMENT_PACK. */
10996 static tree
10998 {
11000 }
11002 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
11003 pack expansion with no extra args, 2 if it has extra args, or 0
11004 if it is not a pack expansion. */
11006 static int
11008 {
11014 /* A decl pack is itself an expansion. */
11021 }
11024 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11026 static tree
11028 {
11035 }
11037 /* This is a subroutine of tsubst_pack_expansion.
11039 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11040 mechanism to store the (non complete list of) arguments of the
11041 substitution and return a non substituted pack expansion, in order
11042 to wait for when we have enough arguments to really perform the
11043 substitution. */
11045 static bool
11049 {
11050 /* If one pack has an expansion and another pack has a normal
11051 argument or if one pack has an empty argument and an another
11052 one hasn't then tsubst_pack_expansion cannot perform the
11053 substitution and need to fall back on the
11054 PACK_EXPANSION_EXTRA mechanism. */
11062 {
11065 parm_pack;
11067 {
11072 /* We can't substitute a pack expansion with extra args into
11073 our pattern. */
11077 else
11079 }
11083 }
11085 }
11087 /* [temp.variadic]/6 says that:
11089 The instantiation of a pack expansion [...]
11090 produces a list E1,E2, ..., En, where N is the number of elements
11091 in the pack expansion parameters.
11093 This subroutine of tsubst_pack_expansion produces one of these Ei.
11095 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11096 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11097 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11098 INDEX is the index 'i' of the element Ei to produce. ARGS,
11099 COMPLAIN, and IN_DECL are the same parameters as for the
11100 tsubst_pack_expansion function.
11102 The function returns the resulting Ei upon successful completion,
11103 or error_mark_node.
11105 Note that this function possibly modifies the ARGS parameter, so
11106 it's the responsibility of the caller to restore it. */
11108 static tree
11110 tree parm_packs,
11112 tree args /* This parm gets
11114 tsubst_flags_t complain,
11115 tree in_decl)
11116 {
11117 tree t;
11120 /* For each parameter pack, change the substitution of the parameter
11121 pack to the ith argument in its argument pack, then expand the
11122 pattern. */
11124 {
11129 ith_elem_is_expansion |=
11132 /* Select the Ith argument from the pack. */
11136 {
11138 {
11143 }
11144 else
11146 }
11147 else
11148 {
11153 {
11155 /* Update the corresponding argument. */
11157 }
11158 else
11159 /* Re-use the ARGUMENT_PACK_SELECT. */
11161 }
11163 }
11165 /* Substitute into the PATTERN with the (possibly altered)
11166 arguments. */
11168 /* Expanding a fixed parameter pack from
11169 coerce_template_parameter_pack. */
11174 {
11177 else
11180 }
11184 else
11187 /* If the Ith argument pack element is a pack expansion, then
11188 the Ith element resulting from the substituting is going to
11189 be a pack expansion as well. */
11194 }
11196 /* When the unexpanded parameter pack in a fold expression expands to an empty
11197 sequence, the value of the expression is as follows; the program is
11198 ill-formed if the operator is not listed in this table.
11200 && true
11201 || false
11202 , void() */
11204 tree
11206 {
11210 {
11219 }
11225 }
11227 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11228 form an expression that combines the two terms using the
11229 operator of T. */
11231 static tree
11233 {
11237 // Handle compound assignment operators.
11242 {
11252 complain);
11253 }
11254 }
11256 /* Substitute ARGS into the pack of a fold expression T. */
11260 {
11262 }
11264 /* Substitute ARGS into the pack of a fold expression T. */
11268 {
11270 }
11272 /* Expand a PACK of arguments into a grouped as left fold.
11273 Given a pack containing elements A0, A1, ..., An and an
11274 operator @, this builds the expression:
11276 ((A0 @ A1) @ A2) ... @ An
11278 Note that PACK must not be empty.
11280 The operator is defined by the original fold expression T. */
11282 static tree
11284 {
11287 {
11290 }
11292 }
11294 /* Substitute into a unary left fold expression. */
11296 static tree
11298 tree in_decl)
11299 {
11304 {
11308 }
11311 else
11313 }
11315 /* Substitute into a binary left fold expression.
11317 Do ths by building a single (non-empty) vector of argumnts and
11318 building the expression from those elements. */
11320 static tree
11322 tree in_decl)
11323 {
11332 {
11337 }
11345 }
11347 /* Expand a PACK of arguments into a grouped as right fold.
11348 Given a pack containing elementns A0, A1, ..., and an
11349 operator @, this builds the expression:
11351 A0@ ... (An-2 @ (An-1 @ An))
11353 Note that PACK must not be empty.
11355 The operator is defined by the original fold expression T. */
11357 tree
11359 {
11360 // Build the expression.
11364 {
11367 }
11369 }
11371 /* Substitute into a unary right fold expression. */
11373 static tree
11375 tree in_decl)
11376 {
11381 {
11385 }
11388 else
11390 }
11392 /* Substitute into a binary right fold expression.
11394 Do ths by building a single (non-empty) vector of arguments and
11395 building the expression from those elements. */
11397 static tree
11399 tree in_decl)
11400 {
11409 {
11414 }
11423 }
11425 /* Walk through the pattern of a pack expansion, adding everything in
11426 local_specializations to a list. */
11428 struct el_data
11429 {
11430 tree extra;
11431 tsubst_flags_t complain;
11432 };
11433 static tree
11435 {
11440 {
11442 {
11443 /* Maybe pull out the PARM_DECL for a partial instantiation. */
11446 {
11452 }
11454 {
11455 /* Handle lambda capture here, since we aren't doing any
11456 substitution now, and so tsubst_copy won't call
11457 process_outer_var_ref. */
11461 {
11467 {
11468 /* Make a new NONTYPE_ARGUMENT_PACK of the capture
11469 proxies. */
11471 {
11476 }
11478 }
11479 }
11480 }
11481 }
11485 }
11487 }
11488 static tree
11490 {
11494 }
11496 /* Substitute ARGS into T, which is an pack expansion
11497 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11498 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11499 (if only a partial substitution could be performed) or
11500 ERROR_MARK_NODE if there was an error. */
11501 tree
11503 tree in_decl)
11504 {
11505 tree pattern;
11510 tree result;
11518 /* Add in any args remembered from an earlier partial instantiation. */
11521 {
11523 {
11524 /* The partial instantiation involved local declarations collected in
11525 extract_local_specs; map from the general template to our local
11526 context. */
11532 /* else inst is already a full instantiation of the pack. */
11534 }
11537 }
11542 /* Determine the argument packs that will instantiate the parameter
11543 packs used in the expansion expression. While we're at it,
11544 compute the number of arguments to be expanded and make sure it
11545 is consistent. */
11548 {
11555 {
11560 else
11563 }
11565 {
11566 /* ??? Support use in other patterns. */
11570 }
11572 {
11573 /* We know we have correct local_specializations if this
11574 expansion is at function scope, or if we're dealing with a
11575 local parameter in a requires expression; for the latter,
11576 tsubst_requires_expr set it up appropriately. */
11579 else
11580 /* We can't rely on local_specializations for a parameter
11581 name used later in a function declaration (such as in a
11582 late-specified return type). Even if it exists, it might
11583 have the wrong value for a recursive call. */
11587 {
11588 /* This parameter pack was used in an unevaluated context. Just
11589 make a dummy decl, since it's only used for its type. */
11592 /* Partial instantiation of the parm_pack, we can't build
11593 up an argument pack yet. */
11595 else
11597 }
11599 /* This argument pack isn't fully instantiated yet. We set this
11600 flag rather than clear arg_pack because we do want to do the
11601 optimization below, and we don't want to substitute directly
11602 into the pattern (as that would expose a NONTYPE_ARGUMENT_PACK
11603 where it isn't expected). */
11605 }
11607 {
11611 }
11612 else
11613 {
11619 }
11626 /* This can only happen if we forget to expand an argument
11627 pack somewhere else. Just return an error, silently. */
11628 {
11632 }
11635 {
11639 /* Don't bother trying to do a partial substitution with
11640 incomplete packs; we'll try again after deduction. */
11648 {
11653 pattern);
11654 else
11656 pattern);
11658 }
11660 /* Keep track of the parameter packs and their corresponding
11661 argument packs. */
11664 }
11665 else
11666 {
11667 /* We can't substitute for this parameter pack. We use a flag as
11668 well as the missing_level counter because function parameter
11669 packs don't have a level. */
11672 }
11673 }
11675 /* If the expansion is just T..., return the matching argument pack, unless
11676 we need to call convert_from_reference on all the elements. This is an
11677 important optimization; see c++/68422. */
11680 {
11683 /* If the argument pack is a single pack expansion, pull it out. */
11688 /* Types need no adjustment, nor does sizeof..., and if we still have
11689 some pack expansion args we won't do anything yet. */
11694 /* Also optimize expression pack expansions if we can tell that the
11695 elements won't have reference type. */
11701 /* Otherwise use the normal path so we get convert_from_reference. */
11702 }
11704 /* We cannot expand this expansion expression, because we don't have
11705 all of the argument packs we need. */
11707 {
11708 /* We got some full packs, but we can't substitute them in until we
11709 have values for all the packs. So remember these until then. */
11718 }
11720 {
11721 /* There were no real arguments, we're just replacing a parameter
11722 pack with another version of itself. Substitute into the
11723 pattern and return a PACK_EXPANSION_*. The caller will need to
11724 deal with that. */
11728 else
11732 }
11737 {
11738 /* We're in a late-specified return type, so create our own local
11739 specializations map; the current map is either NULL or (in the
11740 case of recursive unification) might have bindings that we don't
11741 want to use or alter. */
11744 }
11746 /* For each argument in each argument pack, substitute into the
11747 pattern. */
11751 {
11753 i,
11755 in_decl);
11758 {
11761 }
11762 }
11764 /* Update ARGS to restore the substitution from parameter packs to
11765 their argument packs. */
11767 {
11774 else
11775 {
11783 /* Update the corresponding argument. */
11787 else
11789 }
11790 }
11793 {
11796 }
11798 /* If the dependent pack arguments were such that we end up with only a
11799 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11805 }
11807 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11808 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11809 parameter packs; all parms generated from a function parameter pack will
11810 have the same DECL_PARM_INDEX. */
11812 tree
11814 {
11816 tree patparm;
11819 {
11825 }
11826 else
11827 {
11832 }
11835 }
11837 /* Make an argument pack out of the TREE_VEC VEC. */
11839 static tree
11841 {
11842 tree pack;
11846 else
11847 {
11850 }
11853 }
11855 /* Return an exact copy of template args T that can be modified
11856 independently. */
11858 static tree
11860 {
11868 {
11873 }
11879 }
11881 /* Substitute ARGS into the vector or list of template arguments T. */
11883 static tree
11885 {
11897 {
11899 tree new_arg;
11904 {
11905 /* Substitute into an expansion expression. */
11909 /* Add to the expanded length adjustment the number of
11910 expanded arguments. We subtract one from this
11911 measurement, because the argument pack expression
11912 itself is already counted as 1 in
11913 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11914 the argument pack is empty. */
11916 }
11918 {
11919 /* Substitute into each of the arguments. */
11928 else
11933 }
11934 else
11943 }
11948 /* Make space for the expanded arguments coming from template
11949 argument packs. */
11951 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11952 arguments for a member template.
11953 In that case each TREE_VEC in ORIG_T represents a level of template
11954 arguments, and ORIG_T won't carry any non defaulted argument count.
11955 It will rather be the nested TREE_VECs that will carry one.
11956 In other words, ORIG_T carries a non defaulted argument count only
11957 if it doesn't contain any nested TREE_VEC. */
11959 {
11963 }
11965 {
11969 {
11972 /* Now expand the template argument pack "in place". */
11975 }
11976 else
11977 {
11979 out++;
11980 }
11981 }
11984 }
11986 /* Substitute ARGS into one level PARMS of template parameters. */
11988 static tree
11990 {
11997 {
12005 }
12008 }
12010 /* Return the result of substituting ARGS into the template parameters
12011 given by PARMS. If there are m levels of ARGS and m + n levels of
12012 PARMS, then the result will contain n levels of PARMS. For
12013 example, if PARMS is `template <class T> template <class U>
12014 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
12015 result will be `template <int*, double, class V>'. */
12017 static tree
12019 {
12023 /* When substituting into a template, we must set
12024 PROCESSING_TEMPLATE_DECL as the template parameters may be
12025 dependent if they are based on one-another, and the dependency
12026 predicates are short-circuit outside of templates. */
12033 {
12040 }
12045 }
12047 /* Return the result of substituting ARGS into one template parameter
12048 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
12049 parameter and which TREE_PURPOSE is the default argument of the
12050 template parameter. */
12052 static tree
12054 {
12075 }
12077 /* Substitute the ARGS into the indicated aggregate (or enumeration)
12078 type T. If T is not an aggregate or enumeration type, it is
12079 handled as if by tsubst. IN_DECL is as for tsubst. If
12080 ENTERING_SCOPE is nonzero, T is the context for a template which
12081 we are presently tsubst'ing. Return the substituted value. */
12083 static tree
12085 tree args,
12086 tsubst_flags_t complain,
12087 tree in_decl,
12089 {
12094 {
12099 /* Fall through. */
12103 {
12104 tree argvec;
12105 tree context;
12106 tree r;
12110 /* In "sizeof(X<I>)" we need to evaluate "I". */
12116 /* First, determine the context for the type we are looking
12117 up. */
12120 {
12123 /* If context is a nested class inside a class template,
12124 it may still need to be instantiated (c++/33959). */
12126 }
12128 /* Then, figure out what arguments are appropriate for the
12129 type we are trying to find. For example, given:
12131 template <class T> struct S;
12132 template <class T, class U> void f(T, U) { S<U> su; }
12134 and supposing that we are instantiating f<int, double>,
12135 then our ARGS will be {int, double}, but, when looking up
12136 S we only want {double}. */
12141 else
12142 {
12146 }
12152 }
12153 else
12154 /* This is not a template type, so there's nothing to do. */
12159 }
12160 }
12164 /* Substitute into the default argument ARG (a default argument for
12165 FN), which has the indicated TYPE. */
12167 tree
12169 tsubst_flags_t complain)
12170 {
12175 /* This can happen in invalid code. */
12190 /* This default argument came from a template. Instantiate the
12191 default argument here, not in tsubst. In the case of
12192 something like:
12194 template <class T>
12195 struct S {
12196 static T t();
12197 void f(T = t());
12198 };
12200 we must be careful to do name lookup in the scope of S<T>,
12201 rather than in the current class. */
12203 /* The "this" pointer is not valid in a default argument. */
12205 {
12210 }
12215 /* The default argument expression may cause implicitly defined
12216 member functions to be synthesized, which will result in garbage
12217 collection. We must treat this situation as if we were within
12218 the body of function so as to avoid collecting live data on the
12219 stack. */
12229 /* Restore the "this" pointer. */
12231 {
12234 }
12241 /* Make sure the default argument is reasonable. */
12247 {
12251 }
12254 }
12256 /* Substitute into all the default arguments for FN. */
12258 static void
12260 {
12261 tree arg;
12262 tree tmpl_args;
12266 /* If this function is not yet instantiated, we certainly don't need
12267 its default arguments. */
12270 /* Don't do this again for clones. */
12276 arg;
12282 complain);
12283 }
12285 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12287 static tree
12289 tree lambda_fntype)
12290 {
12295 /* Nobody should be tsubst'ing into non-template functions. */
12299 {
12300 /* If T is not dependent, just return it. */
12304 /* Calculate the most general template of which R is a
12305 specialization. */
12308 /* We're substituting a lambda function under tsubst_lambda_expr but not
12309 directly from it; find the matching function we're already inside.
12310 But don't do this if T is a generic lambda with a single level of
12311 template parms, as in that case we're doing a normal instantiation. */
12317 /* Calculate the complete set of arguments used to
12318 specialize R. */
12320 (DECL_TEMPLATE_RESULT
12326 /* Check to see if we already have this specialization. */
12328 {
12332 }
12334 /* We can see more levels of arguments than parameters if
12335 there was a specialization of a member template, like
12336 this:
12338 template <class T> struct S { template <class U> void f(); }
12339 template <> template <class U> void S<int>::f(U);
12341 Here, we'll be substituting into the specialization,
12342 because that's where we can find the code we actually
12343 want to generate, but we'll have enough arguments for
12344 the most general template.
12346 We also deal with the peculiar case:
12348 template <class T> struct S {
12349 template <class U> friend void f();
12350 };
12351 template <class U> void f() {}
12352 template S<int>;
12353 template void f<double>();
12355 Here, the ARGS for the instantiation of will be {int,
12356 double}. But, we only need as many ARGS as there are
12357 levels of template parameters in CODE_PATTERN. We are
12358 careful not to get fooled into reducing the ARGS in
12359 situations like:
12361 template <class T> struct S { template <class U> void f(U); }
12362 template <class T> template <> void S<T>::f(int) {}
12364 which we can spot because the pattern will be a
12365 specialization in this case. */
12372 }
12373 else
12374 {
12375 /* This special case arises when we have something like this:
12377 template <class T> struct S {
12378 friend void f<int>(int, double);
12379 };
12381 Here, the DECL_TI_TEMPLATE for the friend declaration
12382 will be an IDENTIFIER_NODE. We are being called from
12383 tsubst_friend_function, and we want only to create a
12384 new decl (R) with appropriate types so that we can call
12385 determine_specialization. */
12388 }
12405 /* If we hit excessive deduction depth, the type is bogus even if
12406 it isn't error_mark_node, so don't build a decl. */
12410 /* We do NOT check for matching decls pushed separately at this
12411 point, as they may not represent instantiations of this
12412 template, and in any case are considered separate under the
12413 discrete model. */
12417 /* Clear out the mangled name and RTL for the instantiation. */
12420 /* Leave DECL_INITIAL set on deleted instantiations. */
12425 /* OpenMP UDRs have the only argument a reference to the declared
12426 type. We want to diagnose if the declared type is a reference,
12427 which is invalid, but as references to references are usually
12428 quietly merged, diagnose it here. */
12430 {
12431 tree argtype
12436 "reference type %qT in "
12440 argtype);
12441 }
12444 /* Type-conversion operator. Reconstruct the name, in
12445 case it's the name of one of the template's parameters. */
12455 {
12459 }
12466 /* If this is an instantiation of a function with internal
12467 linkage, we already know what object file linkage will be
12468 assigned to the instantiation. */
12477 /* We'll re-clone as appropriate in instantiate_template. */
12480 /* If we aren't complaining now, return on error before we register
12481 the specialization so that we'll complain eventually. */
12487 /* When instantiating a constrained member, substitute
12488 into the constraints to create a new constraint. */
12491 {
12494 }
12496 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12497 this in the special friend case mentioned above where
12498 GEN_TMPL is NULL. */
12500 {
12505 tree new_r
12508 /* We instantiated this while substituting into
12509 the type earlier (template/friend54.C). */
12512 /* We're not supposed to instantiate default arguments
12513 until they are called, for a template. But, for a
12514 declaration like:
12516 template <class T> void f ()
12517 { extern void g(int i = T()); }
12519 we should do the substitution when the template is
12520 instantiated. We handle the member function case in
12521 instantiate_class_template since the default arguments
12522 might refer to other members of the class. */
12527 }
12528 else
12531 /* Copy the list of befriending classes. */
12535 {
12539 }
12542 {
12546 /* If this is an instantiation of a member template, clone it.
12547 If it isn't, that'll be handled by
12548 clone_constructors_and_destructors. */
12551 }
12562 /* Possibly limit visibility based on template args. */
12565 {
12569 }
12578 }
12580 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12582 static tree
12584 tree lambda_fntype)
12585 {
12586 /* We can get here when processing a member function template,
12587 member class template, or template template parameter. */
12590 tree spec;
12591 tree tmpl_args;
12592 tree full_args;
12593 tree r;
12597 {
12598 /* Template template parameter is treated here. */
12602 /* If we get a real template back, return it. This can happen in
12603 the context of most_specialized_partial_spec. */
12606 else
12607 /* The new TEMPLATE_DECL was built in
12608 reduce_template_parm_level. */
12611 }
12614 {
12615 /* We might already have an instance of this template.
12616 The ARGS are for the surrounding class type, so the
12617 full args contain the tsubst'd args for the context,
12618 plus the innermost args from the template decl. */
12622 /* Because this is a template, the arguments will still be
12623 dependent, even after substitution. If
12624 PROCESSING_TEMPLATE_DECL is not set, the dependency
12625 predicates will short-circuit. */
12633 /* If this is a default template template argument,
12634 tsubst might not have changed anything. */
12642 }
12644 /* Make a new template decl. It will be similar to the
12645 original, but will record the current template arguments.
12646 We also create a new function declaration, which is just
12647 like the old one, but points to this new template, rather
12648 than the old one. */
12653 // Build new template info linking to the original template decl.
12655 {
12658 }
12659 else
12662 /* The template parameters for this new template are all the
12663 template parameters for the old template, except the
12664 outermost level of parameters. */
12667 complain);
12671 {
12672 tree new_type;
12680 /* For a partial specialization, we need to keep pointing to
12681 the primary template. */
12687 }
12688 else
12689 {
12690 tree new_decl;
12694 else
12704 {
12707 }
12708 else
12709 {
12712 }
12713 }
12723 /* Record this non-type partial instantiation. */
12729 }
12731 /* True if FN is the op() for a lambda in an uninstantiated template. */
12733 bool
12735 {
12740 }
12742 /* We're instantiating a variable from template function TCTX. Return the
12743 corresponding current enclosing scope. This gets complicated because lambda
12744 functions in templates are regenerated rather than instantiated, but generic
12745 lambda functions are subsequently instantiated. */
12747 static tree
12749 {
12758 {
12771 }
12773 }
12775 /* Substitute the ARGS into the T, which is a _DECL. Return the
12776 result of the substitution. Issue error and warning messages under
12777 control of COMPLAIN. */
12779 static tree
12781 {
12782 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12783 location_t saved_loc;
12788 /* Set the filename and linenumber to improve error-reporting. */
12793 {
12803 {
12811 {
12812 /* If there is a local specialization that isn't a
12813 parameter pack, it means that we're doing a "simple"
12814 substitution from inside tsubst_pack_expansion. Just
12815 return the local specialization (which will be a single
12816 parm). */
12823 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12824 the parameters in this function parameter pack. */
12828 {
12831 /* Zero-length parameter packs are boring. Just substitute
12832 into the chain. */
12836 }
12837 else
12838 {
12839 /* All we did was update the type. Make a note of that. */
12842 }
12843 }
12845 /* Loop through all of the parameters we'll build. When T is
12846 a function parameter pack, LEN is the number of expanded
12847 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12850 {
12857 /* We're on the Ith parameter of the function parameter
12858 pack. */
12859 {
12860 /* Get the Ith type. */
12863 /* Rename the parameter to include the index. */
12866 }
12868 /* We're dealing with a normal parameter. */
12876 {
12879 else
12882 }
12892 /* Keep track of the first new parameter we
12893 generate. That's what will be returned to the
12894 caller. */
12898 /* Build a proper chain of parameters when substituting
12899 into a function parameter pack. */
12902 }
12904 /* If cp_unevaluated_operand is set, we're just looking for a
12905 single dummy parameter, so don't keep going. */
12910 /* FIRST_R contains the start of the chain we've built. */
12912 }
12916 {
12923 {
12924 /* This field is a lambda capture pack. Return a TREE_VEC of
12925 the expanded fields to instantiate_class_template_1. */
12929 {
12932 }
12933 else
12934 {
12935 /* All we did was update the type. Make a note of that. */
12938 }
12939 }
12942 {
12945 {
12949 }
12959 /* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
12960 number of bits. */
12966 {
12967 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12968 NSDMI in perform_member_init. Still set DECL_INITIAL
12969 so that we know there is one. */
12974 }
12975 /* We don't have to set DECL_CONTEXT here; it is set by
12976 finish_member_declaration. */
12984 }
12988 }
12992 /* We reach here only for member using decls. We also need to check
12993 uses_template_parms because DECL_DEPENDENT_P is not set for a
12994 using-declaration that designates a member of the current
12995 instantiation (c++/53549). */
12998 {
13002 {
13007 {
13011 {
13014 }
13015 else
13016 {
13019 }
13021 }
13022 }
13023 else
13024 {
13030 else
13031 {
13034 }
13035 }
13036 }
13037 else
13038 {
13041 }
13046 {
13049 tree spec;
13051 tree ctx;
13060 {
13061 /* If this is the canonical decl, we don't have to
13062 mess with instantiations, and often we can't (for
13063 typename, template type parms and such). Note that
13064 TYPE_NAME is not correct for the above test if
13065 we've copied the type for a typedef. */
13071 }
13073 /* Check to see if we already have the specialization we
13074 need. */
13077 {
13078 /* T is a static data member or namespace-scope entity.
13079 We have to substitute into namespace-scope variables
13080 (not just variable templates) because of cases like:
13082 template <class T> void f() { extern T t; }
13084 where the entity referenced is not known until
13085 instantiation time. */
13089 {
13091 complain,
13093 /* If CTX is unchanged, then T is in fact the
13094 specialization we want. That situation occurs when
13095 referencing a static data member within in its own
13096 class. We can use pointer equality, rather than
13097 same_type_p, because DECL_CONTEXT is always
13098 canonical... */
13100 /* ... unless T is a member template; in which
13101 case our caller can be willing to create a
13102 specialization of that template represented
13103 by T. */
13107 }
13110 {
13115 argvec = (coerce_innermost_template_parms
13123 }
13124 }
13125 else
13126 {
13127 /* A local variable. */
13129 /* Subsequent calls to pushdecl will fill this in. */
13131 /* Unless this is a reference to a static variable from an
13132 enclosing function, in which case we need to fill it in now. */
13134 {
13138 }
13140 }
13141 /* If we already have the specialization we need, there is
13142 nothing more to do. */
13144 {
13147 }
13149 /* Create a new node for the specialization we need. */
13152 {
13155 else
13163 {
13164 /* Mask off any template args past the variable's context so we
13165 don't replace the auto with an unrelated argument. */
13169 /* This should never happen with the new lambda instantiation
13170 model, but keep the handling just in case. */
13173 }
13175 }
13177 {
13178 /* Even if the original location is out of scope, the
13179 newly substituted one is not. */
13186 {
13187 /* It may seem that this case cannot occur, since:
13189 typedef void f();
13190 void g() { f x; }
13192 declares a function, not a variable. However:
13194 typedef void f();
13195 template <typename T> void g() { T t; }
13196 template void g<f>();
13198 is an attempt to declare a variable with function
13199 type. */
13201 /* R is not yet sufficiently initialized, so we
13202 just use its name. */
13205 }
13207 /* Wait until cp_finish_decl to set this again, to handle
13208 circular dependency (template/instantiate6.C). */
13213 {
13218 {
13221 }
13223 }
13227 }
13233 /* Clear out the mangled name and RTL for the instantiation. */
13237 /* The initializer must not be expanded until it is required;
13238 see [temp.inst]. */
13242 {
13248 /* Possibly limit visibility based on template args. */
13251 {
13255 }
13257 }
13260 {
13261 /* A static data member declaration is always marked
13262 external when it is declared in-class, even if an
13263 initializer is present. We mimic the non-template
13264 processing here. */
13272 }
13273 else
13274 {
13279 }
13287 /* Preserve a typedef that names a type. */
13289 {
13293 /* An alias template specialization can be dependent
13294 even if its underlying type is not. */
13296 }
13299 }
13304 }
13305 #undef RETURN
13307 out:
13308 /* Restore the file and line information. */
13312 }
13314 /* Substitute into the ARG_TYPES of a function type.
13315 If END is a TREE_CHAIN, leave it and any following types
13316 un-substituted. */
13318 static tree
13320 tree args,
13321 tree end,
13322 tsubst_flags_t complain,
13323 tree in_decl)
13324 {
13325 tree remaining_arg_types;
13329 tree default_arg;
13340 {
13341 /* For a pack expansion, perform substitution on the
13342 entire expression. Later on, we'll handle the arguments
13343 one-by-one. */
13348 /* So that we'll spin through the parameters, one by one. */
13350 else
13351 {
13352 /* We only partially substituted into the parameter
13353 pack. Our type is TYPE_PACK_EXPANSION. */
13356 }
13357 }
13370 {
13372 {
13376 }
13378 }
13379 /* DR 657. */
13383 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13384 top-level qualifiers as required. */
13387 /* We do not substitute into default arguments here. The standard
13388 mandates that they be instantiated only when needed, which is
13389 done in build_over_call. */
13392 /* Except that we do substitute default arguments under tsubst_lambda_expr,
13393 since the new op() won't have any associated template arguments for us
13394 to refer to later. */
13400 {
13401 /* We've instantiated a template before its default arguments
13402 have been parsed. This can happen for a nested template
13403 class, and is not an error unless we require the default
13404 argument in a call of this function. */
13405 remaining_arg_types =
13408 }
13409 else
13410 remaining_arg_types =
13412 }
13415 }
13417 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13418 *not* handle the exception-specification for FNTYPE, because the
13419 initial substitution of explicitly provided template parameters
13420 during argument deduction forbids substitution into the
13421 exception-specification:
13423 [temp.deduct]
13425 All references in the function type of the function template to the
13426 corresponding template parameters are replaced by the specified tem-
13427 plate argument values. If a substitution in a template parameter or
13428 in the function type of the function template results in an invalid
13429 type, type deduction fails. [Note: The equivalent substitution in
13430 exception specifications is done only when the function is instanti-
13431 ated, at which point a program is ill-formed if the substitution
13432 results in an invalid type.] */
13434 static tree
13436 tree args,
13437 tsubst_flags_t complain,
13438 tree in_decl)
13439 {
13440 tree return_type;
13442 tree fntype;
13444 /* The TYPE_CONTEXT is not used for function/method types. */
13447 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13448 failure. */
13452 {
13453 /* Substitute the argument types. */
13465 {
13466 /* DR 1207: 'this' is in scope in the trailing return type. */
13468 }
13470 /* Substitute the return type. */
13474 {
13477 }
13478 }
13479 else
13480 /* Substitute the return type. */
13485 /* DR 486 clarifies that creation of a function type with an
13486 invalid return type is a deduction failure. */
13489 {
13491 {
13494 else
13496 }
13498 }
13499 /* And DR 657. */
13504 {
13505 /* Substitute the argument types. */
13510 }
13512 /* Construct a new type node and return it. */
13514 {
13519 }
13520 else
13521 {
13523 /* Don't pick up extra function qualifiers from the basetype. */
13526 {
13527 /* [temp.deduct]
13529 Type deduction may fail for any of the following
13530 reasons:
13532 -- Attempting to create "pointer to member of T" when T
13533 is not a class type. */
13536 r);
13538 }
13543 }
13550 }
13552 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13553 ARGS into that specification, and return the substituted
13554 specification. If there is no specification, return NULL_TREE. */
13556 static tree
13558 tree args,
13559 tsubst_flags_t complain,
13560 tree in_decl,
13562 {
13563 tree specs;
13564 tree new_specs;
13569 {
13570 /* A noexcept-specifier. */
13575 {
13576 /* Defer instantiation of noexcept-specifiers to avoid
13577 excessive instantiations (c++/49107). */
13580 {
13581 /* We already partially instantiated this member template,
13582 so combine the new args with the old. */
13587 }
13588 else
13589 {
13592 }
13593 }
13594 else
13595 new_specs = tsubst_copy_and_build
13599 }
13601 {
13604 else
13606 {
13607 tree spec;
13612 {
13613 /* Expand the pack expansion type. */
13616 in_decl);
13622 else
13623 {
13624 /* We're substituting into a member template, so
13625 we got a TYPE_PACK_EXPANSION back. Add that
13626 expansion and move on. */
13630 expanded_specs,
13631 complain);
13634 }
13635 }
13638 {
13641 else
13646 complain);
13647 }
13650 }
13651 }
13653 }
13655 /* Take the tree structure T and replace template parameters used
13656 therein with the argument vector ARGS. IN_DECL is an associated
13657 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13658 Issue error and warning messages under control of COMPLAIN. Note
13659 that we must be relatively non-tolerant of extensions here, in
13660 order to preserve conformance; if we allow substitutions that
13661 should not be allowed, we may allow argument deductions that should
13662 not succeed, and therefore report ambiguous overload situations
13663 where there are none. In theory, we could allow the substitution,
13664 but indicate that it should have failed, and allow our caller to
13665 make sure that the right thing happens, but we don't try to do this
13666 yet.
13668 This function is used for dealing with types, decls and the like;
13669 for expressions, use tsubst_expr or tsubst_copy. */
13671 tree
13673 {
13696 else
13701 /* Reuse typedefs. We need to do this to handle dependent attributes,
13702 such as attribute aligned. */
13705 {
13709 {
13710 /* DECL represents an alias template and we want to
13711 instantiate it. */
13715 }
13719 {
13723 }
13728 else
13729 /* The typedef is from a non-template context. */
13733 {
13735 r = cp_build_qualified_type_real
13739 }
13740 else
13741 {
13742 /* We don't have an instantiation yet, so drop the typedef. */
13747 }
13748 }
13765 {
13791 {
13797 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13798 needed. */
13804 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13805 with TREE_SIDE_EFFECTS that indicates this is not an integral
13806 constant expression. */
13809 {
13812 }
13815 }
13821 {
13827 /* Early in template argument deduction substitution, we don't
13828 want to reduce the level of 'auto', or it will be confused
13829 with a normal template parm in subsequent deduction. */
13841 {
13844 /* See through ARGUMENT_PACK_SELECT arguments. */
13847 }
13852 {
13854 /* If ARG is an argument pack, we don't actually want to
13855 perform a substitution here, because substitutions
13856 for argument packs are only done
13857 element-by-element. We can get to this point when
13858 substituting the type of a non-type template
13859 parameter pack, when that type actually contains
13860 template parameter packs from an outer template, e.g.,
13862 template<typename... Types> struct A {
13863 template<Types... Values> struct B { };
13864 }; */
13868 {
13874 return cp_build_qualified_type_real
13876 }
13878 {
13879 /* We are processing a type constructed from a
13880 template template parameter. */
13891 /* Consider this code:
13893 template <template <class> class Template>
13894 struct Internal {
13895 template <class Arg> using Bind = Template<Arg>;
13896 };
13898 template <template <class> class Template, class Arg>
13899 using Instantiate = Template<Arg>; //#0
13901 template <template <class> class Template,
13902 class Argument>
13903 using Bind =
13904 Instantiate<Internal<Template>::template Bind,
13905 Argument>; //#1
13907 When #1 is parsed, the
13908 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13909 parameter `Template' in #0 matches the
13910 UNBOUND_CLASS_TEMPLATE representing the argument
13911 `Internal<Template>::template Bind'; We then want
13912 to assemble the type `Bind<Argument>' that can't
13913 be fully created right now, because
13914 `Internal<Template>' not being complete, the Bind
13915 template cannot be looked up in that context. So
13916 we need to "store" `Bind<Argument>' for later
13917 when the context of Bind becomes complete. Let's
13918 store that in a TYPENAME_TYPE. */
13922 argvec),
13923 typename_type,
13924 complain);
13926 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13927 are resolving nested-types in the signature of a
13928 member function templates. Otherwise ARG is a
13929 TEMPLATE_DECL and is the real template to be
13930 instantiated. */
13938 complain);
13939 return cp_build_qualified_type_real
13941 }
13944 else
13945 /* TEMPLATE_PARM_INDEX. */
13947 }
13950 /* This can happen during the attempted tsubst'ing in
13951 unify. This means that we don't yet have any information
13952 about the template parameter in question. */
13955 /* If we get here, we must have been looking at a parm for a
13956 more deeply nested template. Make a new version of this
13957 template parameter, but with a lower level. */
13959 {
13964 {
13966 r = cp_build_qualified_type_real
13970 }
13977 /* Break infinite recursion when substituting the constraints
13979 else
13980 {
13991 {
13992 /* Propagate constraints on placeholders. */
13997 {
14001 }
14002 }
14005 /* We have reduced the level of the template
14006 template parameter, but not the levels of its
14007 template parameters, so canonical_type_parameter
14008 will not be able to find the canonical template
14009 template parameter for this level. Thus, we
14010 require structural equality checking to compare
14011 TEMPLATE_TEMPLATE_PARMs. */
14015 else
14019 {
14021 /* We might need to substitute into the types of non-type
14022 template parameters. */
14034 }
14035 }
14039 /* OK, now substitute the type of the non-type parameter. We
14040 couldn't do it earlier because it might be an auto parameter,
14041 and we wouldn't need to if we had an argument. */
14050 }
14053 }
14056 {
14064 {
14068 }
14071 {
14075 }
14078 {
14082 }
14088 }
14091 /* We should never be tsubsting a binfo. */
14095 /* A vector of template arguments. */
14101 {
14105 /* [temp.deduct]
14107 Type deduction may fail for any of the following
14108 reasons:
14110 -- Attempting to create a pointer to reference type.
14111 -- Attempting to create a reference to a reference type or
14112 a reference to void.
14114 Core issue 106 says that creating a reference to a reference
14115 during instantiation is no longer a cause for failure. We
14116 only enforce this check in strict C++98 mode. */
14120 {
14123 /* We keep track of the last time we issued this error
14124 message to avoid spewing a ton of messages during a
14125 single bad template instantiation. */
14128 {
14133 else
14136 }
14139 }
14143 {
14145 {
14148 type);
14149 else
14151 type);
14152 }
14154 }
14156 {
14160 }
14162 /* In C++0x, during template argument substitution, when there is an
14163 attempt to create a reference to a reference type, reference
14164 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14166 "If a template-argument for a template-parameter T names a type
14167 that is a reference to a type A, an attempt to create the type
14168 'lvalue reference to cv T' creates the type 'lvalue reference to
14169 A,' while an attempt to create the type type rvalue reference to
14170 cv T' creates the type T"
14171 */
14172 r = cp_build_reference_type
14175 else
14180 /* Will this ever be needed for TYPE_..._TO values? */
14184 }
14186 {
14189 {
14190 /* [temp.deduct]
14192 Type deduction may fail for any of the following
14193 reasons:
14195 -- Attempting to create "pointer to member of T" when T
14196 is not a class type. */
14200 }
14202 {
14206 }
14208 {
14212 }
14215 {
14216 /* The type of the implicit object parameter gets its
14217 cv-qualifiers from the FUNCTION_TYPE. */
14218 tree memptr;
14219 tree method_type
14224 complain);
14225 }
14226 else
14229 complain);
14230 }
14233 {
14234 tree fntype;
14235 tree specs;
14240 /* Substitute the exception specification. */
14248 }
14250 {
14255 /* As an optimization, we avoid regenerating the array type if
14256 it will obviously be the same as T. */
14260 /* These checks should match the ones in create_array_type_for_decl.
14262 [temp.deduct]
14264 The deduction may fail for any of the following reasons:
14266 -- Attempting to create an array with an element type that
14267 is void, a function type, or a reference type, or [DR337]
14268 an abstract class type. */
14274 {
14278 }
14286 {
14289 }
14292 }
14295 {
14307 {
14311 }
14313 {
14314 /* Normally, make_typename_type does not require that the CTX
14315 have complete type in order to allow things like:
14317 template <class T> struct S { typename S<T>::X Y; };
14319 But, such constructs have already been resolved by this
14320 point, so here CTX really should have complete type, unless
14321 it's a partial instantiation. */
14324 {
14328 }
14329 }
14336 {
14339 }
14342 {
14344 {
14348 else
14350 }
14352 {
14356 else
14358 }
14359 }
14361 return cp_build_qualified_type_real
14363 }
14366 {
14378 }
14381 {
14382 tree type;
14398 complain);
14399 }
14402 {
14403 tree type;
14414 {
14416 {
14420 }
14423 }
14434 else
14435 {
14439 /* In a template ~id could be either a complement expression
14440 or an unqualified-id naming a destructor; if instantiating
14441 it produces an expression, it's not an id-expression or
14442 member access. */
14445 }
14450 }
14453 {
14457 }
14461 {
14462 tree r;
14466 else
14474 }
14489 /* We should use one of the expression tsubsts for these codes. */
14495 }
14496 }
14498 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14499 expression on the left-hand side of the "." or "->" operator. We
14500 only do the lookup if we had a dependent BASELINK. Otherwise we
14501 adjust it onto the instantiated heirarchy. */
14503 static tree
14506 {
14518 {
14525 }
14532 {
14538 /* Treat as-if non-dependent below. */
14543 {
14549 }
14553 }
14554 else
14555 /* We're going to overwrite pieces below, make a duplicate. */
14558 /* If lookup found a single function, mark it as used at this point.
14559 (If lookup found multiple functions the one selected later by
14560 overload resolution will be marked as used at that point.) */
14566 {
14567 /* Add back the template arguments, if present. */
14572 /* Update the conversion operator type. */
14574 }
14580 {
14582 qualifying_scope,
14583 object_type);
14585 /* We need to call adjust_result_of_qualified_name_lookup in case the
14586 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14587 so that we still get virtual function binding. */
14589 }
14592 }
14594 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14595 true if the qualified-id will be a postfix-expression in-and-of
14596 itself; false if more of the postfix-expression follows the
14597 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14598 of "&". */
14600 static tree
14604 {
14605 tree expr;
14606 tree scope;
14607 tree name;
14609 tree template_args;
14614 /* Figure out what name to look up. */
14617 {
14627 }
14628 else
14629 {
14632 }
14634 /* Substitute into the qualifying scope. When there are no ARGS, we
14635 are just trying to simplify a non-dependent expression. In that
14636 case the qualifying scope may be dependent, and, in any case,
14637 substituting will not help. */
14640 {
14643 }
14644 else
14648 {
14655 }
14658 {
14660 {
14661 /* A BIT_NOT_EXPR is used to represent a destructor. */
14663 {
14667 }
14668 else
14671 }
14672 else
14676 {
14678 {
14682 }
14684 }
14685 }
14688 {
14690 scope);
14691 /* Remember that there was a reference to this entity. */
14694 }
14697 {
14703 }
14706 {
14709 complain);
14710 else
14712 }
14718 {
14719 expr = (adjust_result_of_qualified_name_lookup
14721 expr = (finish_qualified_id_expr
14725 }
14727 /* Expressions do not generally have reference type. */
14729 /* However, if we're about to form a pointer-to-member, we just
14730 want the referenced member referenced. */
14738 }
14740 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14741 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14742 for tsubst. */
14744 static tree
14747 {
14754 {
14755 /* If we had an initializer but it
14756 instantiated to nothing,
14757 value-initialize the object. This will
14758 only occur when the initializer was a
14759 pack expansion where the parameter packs
14760 used in that expansion were of length
14761 zero. */
14763 complain);
14768 }
14771 }
14773 /* Like tsubst, but deals with expressions. This function just replaces
14774 template parms; to finish processing the resultant expression, use
14775 tsubst_copy_and_build or tsubst_expr. */
14777 static tree
14779 {
14781 tree r;
14789 {
14794 {
14795 /* We get here for a use of 'this' in an NSDMI. */
14799 /* This can happen for a parameter name used later in a function
14800 declaration (such as in a late-specified return type). Just
14801 make a dummy decl, since it's only used for its type. */
14804 /* Give it the template pattern as its context; its true context
14805 hasn't been instantiated yet and this is good enough for
14806 mangling. */
14808 }
14817 {
14818 tree enum_type;
14819 tree v;
14823 /* There is no need to substitute into namespace-scope
14824 enumerators. */
14827 /* If ARGS is NULL, then T is known to be non-dependent. */
14831 /* Unfortunately, we cannot just call lookup_name here.
14832 Consider:
14834 template <int I> int f() {
14835 enum E { a = I };
14836 struct S { void g() { E e = a; } };
14837 };
14839 When we instantiate f<7>::S::g(), say, lookup_name is not
14840 clever enough to find f<7>::a. */
14841 enum_type
14851 /* We didn't find the name. That should never happen; if
14852 name-lookup found it during preliminary parsing, we
14853 should find it again here during instantiation. */
14855 }
14860 {
14861 tree ctx;
14866 {
14869 {
14873 }
14875 }
14876 }
14886 {
14889 {
14890 /* First try name lookup to find the instantiation. */
14893 {
14894 /* Make sure that the one we found is the one we want. */
14898 }
14902 else
14903 {
14904 /* This can happen for a variable used in a
14905 late-specified return type of a local lambda, or for a
14906 local static or constant. Building a new VAR_DECL
14907 should be OK in all those cases. */
14910 /* Avoid infinite recursion (79640). */
14913 {
14914 /* We can't call cp_finish_decl, so handle the
14915 initializer by hand. */
14930 }
14937 }
14938 /* Remember this for subsequent uses. */
14941 }
14944 }
14945 else
14955 /* An OVERLOAD will always be a non-dependent overload set; an
14956 overload set from function scope will just be represented with an
14957 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14959 /* We must have marked any lookups as persistent. */
14975 {
14976 /* Template template argument like the following example need
14977 special treatment:
14979 template <template <class> class TT> struct C {};
14980 template <class T> struct D {
14981 template <class U> struct E {};
14982 C<E> c; // #1
14983 };
14984 D<int> d; // #2
14986 We are processing the template argument `E' in #1 for
14987 the template instantiation #2. Originally, `E' is a
14988 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14989 have to substitute this with one having context `D<int>'. */
14993 {
14994 /* When rewriting a constructor into a deduction guide, a
14995 non-dependent name can become dependent, so memtmpl<args>
14996 becomes context::template memtmpl<args>. */
15000 }
15002 }
15003 else
15004 /* Ordinary template template argument. */
15009 {
15010 /* Handle location wrappers by substituting the wrapped node
15011 first, *then* reusing the resulting type. Doing the type
15012 first ensures that we handle template parameters and
15013 parameter pack expansions. */
15017 }
15027 {
15031 }
15036 {
15045 /* We only want to compute the number of arguments. */
15048 else
15055 {
15057 /* Set TREE_USED for the benefit of -Wunused. */
15061 }
15069 {
15074 else
15080 else
15083 }
15084 else
15086 }
15088 {
15096 }
15097 /* Fall through */
15113 {
15117 }
15120 {
15121 tree object;
15122 tree name;
15127 {
15131 }
15134 {
15144 }
15149 in_decl);
15150 else
15153 }
15191 {
15195 }
15198 {
15203 }
15206 {
15210 }
15213 {
15221 }
15227 {
15234 }
15237 {
15244 }
15247 {
15254 }
15257 {
15258 /* Substituted template arguments */
15267 }
15270 {
15290 }
15315 /* Fall through. */
15318 {
15321 }
15322 else
15326 /* This is handled by tsubst_copy_and_build. */
15330 {
15334 }
15337 /* We shouldn't have built any of these during initial template
15338 generation. Instead, they should be built during instantiation
15339 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15343 {
15353 }
15371 {
15372 /* Instantiate any typedefs in the type. */
15377 }
15380 /* These can sometimes show up in a partial instantiation, but never
15381 involve template parms. */
15397 /* ??? There's no point in copying it for now, but maybe some
15398 day it will contain more information, such as a pointer back
15399 to the containing function, inlined copy or so. */
15403 /* We shouldn't get here, but keep going if !flag_checking. */
15407 }
15408 }
15410 /* Helper function for tsubst_omp_clauses, used for instantiation of
15411 OMP_CLAUSE_DECL of clauses. */
15413 static tree
15415 tree in_decl)
15416 {
15420 /* Handle an OpenMP array section represented as a TREE_LIST (or
15421 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15422 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15423 TREE_LIST. We can handle it exactly the same as an array section
15424 (purpose, value, and a chain), even though the nomenclature
15425 (low_bound, length, etc) is different. */
15427 {
15428 tree low_bound
15434 in_decl);
15443 }
15446 /* Undo convert_from_reference tsubst_expr could have called. */
15452 }
15454 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15456 static tree
15459 {
15464 {
15470 {
15473 {
15479 }
15480 /* FALLTHRU */
15495 in_decl);
15527 {
15530 {
15537 }
15538 else
15540 }
15543 in_decl);
15549 in_decl);
15557 in_decl);
15559 {
15562 }
15567 else
15570 in_decl,
15594 }
15597 {
15607 /* tsubst_expr on SCOPE_REF results in returning
15608 finish_non_static_data_member result. Undo that here. */
15612 {
15617 {
15621 CASE_CONVERT:
15630 /* FALLTHRU */
15634 }
15635 }
15641 {
15644 {
15647 }
15648 }
15652 }
15653 }
15657 {
15662 {
15665 }
15666 }
15668 }
15670 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15672 static tree
15674 tree in_decl)
15675 {
15676 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15696 {
15699 else
15700 {
15704 }
15705 }
15710 #undef RECUR
15711 }
15713 /* Used to temporarily communicate the list of #pragma omp parallel
15714 clauses to #pragma omp for instantiation if they are combined
15715 together. */
15719 /* Substitute one OMP_FOR iterator. */
15721 static void
15726 {
15727 #define RECUR(NODE) \
15728 tsubst_expr ((NODE), args, complain, in_decl, \
15729 integral_constant_expression_p)
15736 {
15739 }
15745 {
15746 /* We need to jump through some hoops to handle declarations in the
15747 init-statement, since we might need to handle auto deduction,
15748 but we need to keep control of initialization. */
15752 }
15753 else
15754 {
15756 {
15759 {
15763 {
15767 CASE_CONVERT:
15775 {
15778 }
15779 /* FALLTHRU */
15783 }
15784 }
15785 }
15786 else
15788 }
15799 {
15801 {
15802 /* Declare the variable, but don't let that initialize it. */
15807 }
15812 {
15817 }
15818 else
15825 }
15828 {
15829 /* Declare and initialize the variable. */
15832 }
15834 {
15838 {
15840 {
15846 {
15849 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15854 }
15857 {
15859 decl);
15861 }
15864 {
15866 decl);
15868 }
15869 else
15871 }
15874 }
15876 {
15881 {
15884 }
15885 }
15886 }
15889 {
15893 }
15894 else
15898 {
15909 {
15917 }
15918 else
15924 {
15930 }
15934 {
15942 }
15943 else
15949 }
15955 #undef RECUR
15956 }
15958 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15959 of OMP_TARGET's body. */
15961 static tree
15963 {
15966 {
15975 }
15977 }
15979 /* Helper function for tsubst_expr. For decomposition declaration
15980 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15981 also the corresponding decls representing the identifiers
15982 of the decomposition declaration. Return DECL if successful
15983 or error_mark_node otherwise, set *FIRST to the first decl
15984 in the list chained through DECL_CHAIN and *CNT to the number
15985 of such decls. */
15987 static tree
15991 {
15996 decl2
16001 {
16003 {
16006 }
16023 {
16026 }
16027 else
16029 }
16032 }
16034 /* Like tsubst_copy for expressions, etc. but also does semantic
16035 processing. */
16037 tree
16040 {
16041 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
16042 #define RECUR(NODE) \
16043 tsubst_expr ((NODE), args, complain, in_decl, \
16044 integral_constant_expression_p)
16047 tree r;
16048 location_t loc;
16060 {
16062 {
16063 tree_stmt_iterator i;
16067 }
16082 else
16092 {
16094 tree init;
16100 {
16110 else
16112 }
16115 {
16116 /* We're in tsubst_lambda_expr, we've already inserted a new
16117 capture proxy, so look it up and register it. */
16118 tree inst;
16120 {
16121 inst = (retrieve_local_specialization
16124 }
16125 else
16126 {
16130 }
16133 }
16136 /* Don't copy the old closure; we'll create a new one in
16137 tsubst_lambda_expr. */
16139 else
16140 {
16144 {
16145 /* By marking the declaration as instantiated, we avoid
16146 trying to instantiate it. Since instantiate_decl can't
16147 handle local variables, and since we've already done
16148 all that needs to be done, that's the right thing to
16149 do. */
16154 /* Anonymous aggregates are a special case. */
16157 {
16160 {
16164 }
16166 }
16172 {
16177 }
16178 else
16179 {
16184 {
16185 /* For __PRETTY_FUNCTION__ we have to adjust the
16186 initializer. */
16190 }
16191 else
16195 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16200 {
16202 tree first;
16203 tree ndecl
16211 }
16212 else
16214 }
16215 }
16216 }
16219 }
16229 {
16233 }
16238 {
16239 /* Construct another range_for, if this is not a final
16240 substitution (for inside inside a generic lambda of a
16241 template). Otherwise convert to a regular for. */
16243 stmt = (processing_template_decl
16259 {
16263 }
16264 else
16265 {
16271 }
16277 }
16284 {
16288 }
16294 {
16298 }
16311 else
16312 {
16319 }
16325 {
16334 }
16342 else
16350 else
16371 {
16378 }
16382 {
16384 tree label;
16391 }
16397 /* Computed goto's must be tsubst'd into. On the other hand,
16398 non-computed gotos must not be; the identifier in question
16399 will have no binding. */
16401 else
16407 {
16423 }
16428 {
16433 }
16434 else
16435 {
16440 else
16447 else
16453 else
16455 }
16459 {
16463 {
16465 /* Prevent instantiate_decl from trying to instantiate
16466 this variable. We've already done all that needs to be
16467 done. */
16470 }
16475 }
16481 {
16482 /* Local classes are not independent templates; they are
16483 instantiated along with their containing function. And this
16484 way we don't have to deal with pushing out of one local class
16485 to instantiate a member of another local class. */
16486 /* Closures are handled by the LAMBDA_EXPR. */
16496 }
16500 {
16501 tree condition;
16504 condition =
16506 args,
16515 }
16521 in_decl);
16556 {
16569 in_decl);
16571 {
16578 }
16590 integral_constant_expression_p);
16601 else
16602 {
16610 }
16614 }
16619 /* FALLTHRU */
16626 in_decl);
16643 in_decl);
16654 {
16657 {
16658 /* For combined target teams, ensure the num_teams and
16659 thread_limit clause expressions are evaluated on the host,
16660 before entering the target construct. */
16661 tree c;
16667 {
16676 OMP_CLAUSE_FIRSTPRIVATE);
16680 }
16681 }
16682 }
16742 {
16747 {
16750 }
16756 }
16757 else
16758 {
16765 {
16768 }
16771 {
16776 {
16779 }
16785 }
16786 else
16787 {
16791 }
16794 }
16798 {
16804 {
16808 {
16813 }
16817 }
16818 else
16819 {
16824 }
16825 }
16829 {
16833 }
16846 /* If the first operand was a statement, we're done with it. */
16850 complain));
16864 integral_constant_expression_p));
16865 }
16868 out:
16871 #undef RECUR
16872 #undef RETURN
16873 }
16875 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16876 function. For description of the body see comment above
16877 cp_parser_omp_declare_reduction_exprs. */
16879 static void
16881 {
16887 tree_stmt_iterator tsi;
16898 {
16917 }
16919 {
16939 }
16940 }
16942 /* T is a postfix-expression that is not being used in a function
16943 call. Return the substituted version of T. */
16945 static tree
16947 tsubst_flags_t complain,
16948 tree in_decl)
16949 {
16953 else
16959 }
16961 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16962 instantiation context. Instantiating a pack expansion containing a lambda
16963 might result in multiple lambdas all based on the same lambda in the
16964 template. */
16966 tree
16968 {
16982 else
16990 {
17002 else
17007 {
17016 }
17017 else
17018 {
17024 }
17025 }
17029 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17047 else
17048 {
17049 /* Fix the type of 'this'. */
17055 {
17059 }
17060 else
17061 {
17065 }
17067 /* Let finish_function set this. */
17073 else
17074 /* Still increment function_depth so that we don't GC in the
17075 middle of an expression. */
17091 else
17094 /* The capture list was built up in reverse order; fix that now. */
17101 }
17108 }
17110 /* Like tsubst but deals with expressions and performs semantic
17111 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
17113 tree
17115 tree args,
17116 tsubst_flags_t complain,
17117 tree in_decl,
17120 {
17121 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
17122 #define RECUR(NODE) \
17123 tsubst_copy_and_build (NODE, args, complain, in_decl, \
17125 integral_constant_expression_p)
17128 location_t loc;
17137 /* N3276 decltype magic only applies to calls at the top level or on the
17138 right side of a comma. */
17143 {
17146 /* Fall through. */
17148 {
17149 tree decl;
17150 cp_id_kind idk;
17155 {
17158 }
17160 /* Look up the name. */
17163 /* By convention, expressions use ERROR_MARK_NODE to indicate
17164 failure, not NULL_TREE. */
17170 integral_constant_expression_p,
17178 input_location);
17182 {
17186 }
17188 }
17191 {
17192 tree object;
17202 {
17207 }
17213 {
17216 }
17217 else
17224 else
17226 }
17229 {
17233 {
17234 /* A type conversion to reference type will be enclosed in
17235 such an indirect ref, but the substitution of the cast
17236 will have also added such an indirect ref. */
17238 }
17239 else
17247 }
17250 {
17254 }
17257 {
17261 {
17266 }
17268 /* We'll pass this to convert_nontype_argument again, we don't need
17269 to actually perform any conversion here. */
17275 flags));
17276 }
17279 {
17283 }
17290 {
17291 tree type;
17297 {
17302 }
17309 {
17327 }
17330 }
17364 else
17366 in_decl);
17401 {
17408 tree r = build_x_binary_op
17410 op0,
17412 ? ERROR_MARK
17414 op1,
17416 ? ERROR_MARK
17424 }
17427 {
17431 }
17447 /* Fall through */
17450 {
17451 tree r;
17457 {
17458 /* When there are no ARGS, we are trying to evaluate a
17459 non-dependent expression from the parser. Trying to do
17460 the substitutions may not work. */
17463 }
17464 else
17465 {
17470 else
17473 /*integral_constant_expression_p=*/
17477 }
17481 else
17485 {
17487 {
17489 {
17493 }
17494 else
17498 }
17500 }
17502 }
17505 {
17515 }
17531 {
17535 tree r = build_x_modify_expr
17538 /* TREE_NO_WARNING must be set if either the expression was
17539 parenthesized or it uses an operator such as >>= rather
17540 than plain assignment. In the former case, it was already
17541 set and must be copied. In the latter case,
17542 build_x_modify_expr sets it and it must not be reset
17543 here. */
17548 }
17553 /* Remember that there was a reference to this entity. */
17560 {
17565 tree ret;
17569 else
17570 {
17574 }
17576 /* If there was an initializer in the original tree, but it
17577 instantiated to an empty list, then we should pass a
17578 non-NULL empty vector to tell build_new that it was an
17579 empty initializer() rather than no initializer. This can
17580 only happen when the initializer is a pack expansion whose
17581 parameter packs are of length zero. */
17584 else
17585 {
17589 else
17590 {
17593 }
17594 }
17600 complain);
17608 }
17611 {
17617 complain));
17618 }
17621 {
17625 integral_constant_expression_p);
17627 op0,
17630 }
17633 {
17634 tree function;
17639 tree ret;
17642 /* Internal function with no arguments. */
17646 /* When we parsed the expression, we determined whether or
17647 not Koenig lookup should be performed. */
17650 {
17653 }
17655 {
17660 }
17662 {
17663 /* Do nothing; calling tsubst_copy_and_build on an identifier
17664 would incorrectly perform unqualified lookup again.
17666 Note that we can also have an IDENTIFIER_NODE if the earlier
17667 unqualified lookup found a member function; in that case
17668 koenig_p will be false and we do want to do the lookup
17669 again to find the instantiated member function.
17671 FIXME but doing that causes c++/15272, so we need to stop
17672 using IDENTIFIER_NODE in that situation. */
17674 }
17675 else
17676 {
17678 {
17684 }
17685 else
17690 /* Avoid error about taking the address of a constructor. */
17694 in_decl,
17696 integral_constant_expression_p);
17700 }
17705 {
17710 else
17711 {
17712 /* Expand the pack expansion and push each entry onto
17713 CALL_ARGS. */
17716 {
17721 {
17726 }
17727 }
17728 else
17729 {
17730 /* A partial substitution. Add one entry. */
17732 }
17733 }
17734 }
17736 /* We do not perform argument-dependent lookup if normal
17737 lookup finds a non-function, in accordance with the
17738 expected resolution of DR 218. */
17741 /* If lookup found a member function, the Koenig lookup is
17742 not appropriate, even if an unqualified-name was used
17743 to denote the function. */
17746 /* Only do this when substitution turns a dependent call
17747 into a non-dependent call. */
17755 {
17757 {
17758 /* For backwards compatibility and good diagnostics, try
17759 the unqualified lookup again if we aren't in SFINAE
17760 context. */
17761 tree unq = (tsubst_copy_and_build
17763 integral_constant_expression_p));
17765 {
17768 }
17771 {
17772 /* In a lambda fn, we have to be careful to not
17773 introduce new this captures. Legacy code can't
17774 be using lambdas anyway, so it's ok to be
17775 stricter. */
17780 "and no declarations were found by "
17781 "argument-dependent lookup at the point "
17788 else
17792 {
17803 {
17805 input_location);
17807 "declarations in dependent base %qT are "
17813 else
17817 }
17818 else
17820 "%qD declared here, later in the "
17823 {
17826 }
17827 }
17830 }
17831 }
17833 {
17838 }
17839 }
17841 /* Remember that there was a reference to this entity. */
17845 {
17848 }
17850 /* Put back tf_decltype for the actual call. */
17855 {
17859 {
17861 "wrong number of arguments to "
17864 }
17865 else
17867 input_location),
17872 /* Unsupported internal function with arguments. */
17874 }
17877 complain);
17879 {
17894 complain);
17895 else
17896 ret = (build_new_method_call
17901 complain));
17902 }
17903 else
17906 koenig_p,
17907 complain);
17912 {
17918 {
17924 {
17927 else
17929 /* The thunk location is not interesting. */
17931 }
17932 }
17933 }
17936 }
17939 {
17945 {
17947 {
17952 }
17953 else
17954 {
17959 }
17961 }
17962 else
17963 {
17966 }
17971 }
17974 {
17979 input_location));
17980 }
17983 {
17991 {
17992 /* We have pack expansions, so expand those and
17993 create a new list out of it. */
17996 tree chain;
17999 /* Expand the argument expressions. */
18007 /* Build the rest of the list. */
18012 /* Determine the number of arguments. */
18014 {
18017 }
18020 else
18021 {
18022 /* Since we only performed a partial substitution into
18023 the argument pack, we only RETURN (a single list
18024 node. */
18031 }
18033 /* Convert the argument vectors into a TREE_LIST */
18036 {
18037 /* Grab the Ith values. */
18038 i--;
18041 value
18045 /* Build the list (backwards). */
18047 }
18050 }
18066 }
18069 {
18070 tree object;
18071 tree object_type;
18072 tree member;
18073 tree r;
18077 /* Remember that there was a reference to this entity. */
18088 else
18094 {
18099 }
18103 {
18105 {
18110 {
18113 }
18115 {
18120 }
18121 }
18122 }
18125 {
18126 /* Lookup the template functions now that we know what the
18127 scope is. */
18135 {
18138 args);
18139 member = (adjust_result_of_qualified_name_lookup
18141 object_type));
18142 }
18143 else
18144 {
18146 input_location);
18148 }
18149 }
18153 {
18155 {
18159 else
18162 }
18164 }
18168 complain);
18172 }
18179 {
18187 tree r;
18192 /* We do not want to process the index of aggregate
18193 initializers as they are identifier nodes which will be
18194 looked up by digest_init. */
18200 {
18202 /* An identifier index is looked up in the type
18203 being initialized, not the current scope. */
18208 {
18209 /* Substitute into the pack expansion. */
18211 in_decl);
18215 ;
18217 /* Just move the argument into place. */
18219 else
18220 {
18221 /* Update the length of the final CONSTRUCTOR
18222 arguments vector, and note that we will need to
18223 copy.*/
18226 }
18227 }
18228 else
18230 }
18233 {
18238 {
18240 {
18245 }
18246 else
18248 }
18249 }
18255 {
18260 }
18264 }
18267 {
18270 {
18273 }
18274 else
18275 {
18278 }
18279 }
18284 /* Fall through */
18287 {
18289 /* ??? We're doing a subset of finish_id_expression here. */
18291 && !processing_template_decl
18292 && !cp_unevaluated_operand
18295 {
18297 /* Replace an evaluated use of the thread_local variable with
18298 a call to its wrapper. */
18300 }
18305 /* If the original type was a reference, we'll be wrapped in
18306 the appropriate INDIRECT_REF. */
18309 }
18312 {
18316 }
18319 {
18320 tree object_ptr
18327 }
18334 {
18345 }
18348 {
18354 integral_constant_expression_p);
18358 /* If the resulting list of expression statement is empty,
18359 fold it further into void_node. */
18364 }
18367 {
18371 }
18374 /* We can get here for a constant initializer of non-dependent type.
18375 FIXME stop folding in cp_parser_initializer_clause. */
18376 {
18378 complain);
18380 }
18384 integral_constant_expression_p));
18390 {
18395 complain));
18396 }
18403 /* We should only see these for location wrapper nodes, or within
18404 instantiate_non_dependent_expr (when args is NULL_TREE). */
18409 /* fallthrough. */
18412 /* Handle Objective-C++ constructs, if appropriate. */
18413 {
18414 tree subst
18419 }
18421 }
18423 #undef RECUR
18424 #undef RETURN
18425 out:
18428 }
18430 /* Verify that the instantiated ARGS are valid. For type arguments,
18431 make sure that the type's linkage is ok. For non-type arguments,
18432 make sure they are constants if they are integral or enumerations.
18433 Emit an error under control of COMPLAIN, and return TRUE on error. */
18435 static bool
18437 {
18441 {
18451 }
18453 {
18454 /* [basic.link]: A name with no linkage (notably, the name
18455 of a class or enumeration declared in a local scope)
18456 shall not be used to declare an entity with linkage.
18457 This implies that names with no linkage cannot be used as
18458 template arguments
18460 DR 757 relaxes this restriction for C++0x. */
18465 {
18466 /* DR 488 makes use of a type with no linkage cause
18467 type deduction to fail. */
18469 {
18472 else
18475 }
18477 }
18478 /* In order to avoid all sorts of complications, we do not
18479 allow variably-modified types as template arguments. */
18481 {
18485 }
18486 }
18487 /* Class template and alias template arguments should be OK. */
18489 ;
18490 /* A non-type argument of integral or enumerated type must be a
18491 constant. */
18496 {
18500 }
18502 }
18504 static bool
18506 {
18511 {
18514 }
18518 }
18520 /* We're out of SFINAE context now, so generate diagnostics for the access
18521 errors we saw earlier when instantiating D from TMPL and ARGS. */
18523 static void
18525 {
18537 }
18539 /* Instantiate the indicated variable, function, or alias template TMPL with
18540 the template arguments in TARG_PTR. */
18542 static tree
18544 {
18546 tree fndecl;
18547 tree gen_tmpl;
18548 tree spec;
18556 /* If this function is a clone, handle it specially. */
18558 {
18559 tree spec;
18560 tree clone;
18562 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18563 DECL_CLONED_FUNCTION. */
18569 /* Look for the clone. */
18573 /* We should always have found the clone by now. */
18576 }
18581 /* Check to see if we already have this specialization. */
18585 /* targ_ptr only has the innermost template args, so add the outer ones
18586 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18587 the case of a non-dependent call within a template definition). */
18588 targ_ptr = (add_outermost_template_args
18590 targ_ptr));
18592 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18593 but it doesn't seem to be on the hot path. */
18602 {
18604 {
18608 }
18610 }
18613 complain))
18616 /* We are building a FUNCTION_DECL, during which the access of its
18617 parameters and return types have to be checked. However this
18618 FUNCTION_DECL which is the desired context for access checking
18619 is not built yet. We solve this chicken-and-egg problem by
18620 deferring all checks until we have the FUNCTION_DECL. */
18623 /* Instantiation of the function happens in the context of the function
18624 template, not the context of the overload resolution we're doing. */
18626 /* If there are dependent arguments, e.g. because we're doing partial
18627 ordering, make sure processing_template_decl stays set. */
18631 {
18635 }
18641 {
18642 /* We need to determine if we're using a partial or explicit
18643 specialization now, because the type of the variable could be
18644 different. */
18650 {
18655 }
18656 }
18658 /* Substitute template parameters to obtain the specialization. */
18666 {
18669 }
18671 /* The DECL_TI_TEMPLATE should always be the immediate parent
18672 template, not the most general template. */
18676 /* Now we know the specialization, compute access previously
18677 deferred. Do no access control for inheriting constructors,
18678 as we already checked access for the inherited constructor. */
18681 {
18686 }
18689 /* If we've just instantiated the main entry point for a function,
18690 instantiate all the alternate entry points as well. We do this
18691 by cloning the instantiation of the main entry point, not by
18692 instantiating the template clones. */
18697 {
18699 {
18700 /* Remember to reinstantiate when we're out of SFINAE so the user
18701 can see the errors. */
18703 }
18705 }
18707 }
18709 /* Wrapper for instantiate_template_1. */
18711 tree
18713 {
18714 tree ret;
18719 }
18721 /* Instantiate the alias template TMPL with ARGS. Also push a template
18722 instantiation level, which instantiate_template doesn't do because
18723 functions and variables have sufficient context established by the
18724 callers. */
18726 static tree
18728 {
18735 {
18738 }
18740 args =
18748 /* We can't free this if a pending_template entry or last_error_tinst_level
18749 is pointing at it. */
18755 }
18757 /* PARM is a template parameter pack for FN. Returns true iff
18758 PARM is used in a deducible way in the argument list of FN. */
18760 static bool
18762 {
18765 {
18767 tree packs;
18773 {
18774 /* The template parameter pack is used in a function parameter
18775 pack. If this is the end of the parameter list, the
18776 template parameter pack is deducible. */
18779 else
18780 /* Otherwise, not. Well, it could be deduced from
18781 a non-pack parameter, but doing so would end up with
18782 a deduction mismatch, so don't bother. */
18784 }
18785 }
18786 /* The template parameter pack isn't used in any function parameter
18787 packs, but it might be used deeper, e.g. tuple<Args...>. */
18789 }
18791 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18792 NARGS elements of the arguments that are being used when calling
18793 it. TARGS is a vector into which the deduced template arguments
18794 are placed.
18796 Returns either a FUNCTION_DECL for the matching specialization of FN or
18797 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18798 true, diagnostics will be printed to explain why it failed.
18800 If FN is a conversion operator, or we are trying to produce a specific
18801 specialization, RETURN_TYPE is the return type desired.
18803 The EXPLICIT_TARGS are explicit template arguments provided via a
18804 template-id.
18806 The parameter STRICT is one of:
18808 DEDUCE_CALL:
18809 We are deducing arguments for a function call, as in
18810 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18811 deducing arguments for a call to the result of a conversion
18812 function template, as in [over.call.object].
18814 DEDUCE_CONV:
18815 We are deducing arguments for a conversion function, as in
18816 [temp.deduct.conv].
18818 DEDUCE_EXACT:
18819 We are deducing arguments when doing an explicit instantiation
18820 as in [temp.explicit], when determining an explicit specialization
18821 as in [temp.expl.spec], or when taking the address of a function
18822 template, as in [temp.deduct.funcaddr]. */
18824 tree
18826 tree explicit_targs,
18827 tree targs,
18830 tree return_type,
18831 unification_kind_t strict,
18835 {
18836 tree parms;
18837 tree fntype;
18850 tree tinst;
18856 full_targs = (add_outermost_template_args
18858 targs));
18863 /* In C++0x, it's possible to have a function template whose type depends
18864 on itself recursively. This is most obvious with decltype, but can also
18865 occur with enumeration scope (c++/48969). So we need to catch infinite
18866 recursion and reject the substitution at deduction time; this function
18867 will return error_mark_node for any repeated substitution.
18869 This also catches excessive recursion such as when f<N> depends on
18870 f<N-1> across all integers, and returns error_mark_node for all the
18871 substitutions back up to the initial one.
18873 This is, of course, not reentrant. */
18883 {
18884 /* [temp.deduct]
18886 The specified template arguments must match the template
18887 parameters in kind (i.e., type, nontype, template), and there
18888 must not be more arguments than there are parameters;
18889 otherwise type deduction fails.
18891 Nontype arguments must match the types of the corresponding
18892 nontype template parameters, or must be convertible to the
18893 types of the corresponding nontype parameters as specified in
18894 _temp.arg.nontype_, otherwise type deduction fails.
18896 All references in the function type of the function template
18897 to the corresponding template parameters are replaced by the
18898 specified template argument values. If a substitution in a
18899 template parameter or in the function type of the function
18900 template results in an invalid type, type deduction fails. */
18911 explicit_targs);
18913 /* Adjust any explicit template arguments before entering the
18914 substitution context. */
18915 explicit_targs
18917 complain,
18923 /* Substitute the explicit args into the function type. This is
18924 necessary so that, for instance, explicitly declared function
18925 arguments can match null pointed constants. If we were given
18926 an incomplete set of explicit args, we must not do semantic
18927 processing during substitution as we could create partial
18928 instantiations. */
18930 {
18935 /* Dig out the actual parm. */
18938 {
18941 }
18943 {
18946 }
18949 /* No explicit argument for this template parameter. */
18953 {
18954 /* Mark the argument pack as "incomplete". We could
18955 still deduce more arguments during unification.
18956 We remove this mark in type_unification_real. */
18958 {
18962 }
18964 /* We have some incomplete argument packs. */
18966 }
18967 }
18971 {
18974 }
18977 /* Ignore any access checks; we'll see them again in
18978 instantiate_template and they might have the wrong
18979 access path at this point. */
18991 /* Place the explicitly specified arguments in TARGS. */
18995 }
18997 /* Never do unification on the 'this' parameter. */
19001 {
19002 /* We're deducing for a call to the result of a template conversion
19003 function. The parms we really want are in return_type. */
19007 }
19009 {
19018 }
19020 /* We allow incomplete unification without an error message here
19021 because the standard doesn't seem to explicitly prohibit it. Our
19022 callers must be ready to deal with unification failures in any
19023 event. */
19026 /* If we aren't explaining yet, push tinst context so we can see where
19027 any errors (e.g. from class instantiations triggered by instantiation
19028 of default template arguments) come from. If we are explaining, this
19029 context is redundant. */
19031 {
19034 }
19036 /* type_unification_real will pass back any access checks from default
19037 template argument substitution. */
19049 /* Now that we have bindings for all of the template arguments,
19050 ensure that the arguments deduced for the template template
19051 parameters have compatible template parameter lists. We cannot
19052 check this property before we have deduced all template
19053 arguments, because the template parameter types of a template
19054 template parameter might depend on prior template parameters
19055 deduced after the template template parameter. The following
19056 ill-formed example illustrates this issue:
19058 template<typename T, template<T> class C> void f(C<5>, T);
19060 template<int N> struct X {};
19062 void g() {
19063 f(X<5>(), 5l); // error: template argument deduction fails
19064 }
19066 The template parameter list of 'C' depends on the template type
19067 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
19068 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
19069 time that we deduce 'C'. */
19072 {
19075 }
19077 /* All is well so far. Now, check:
19079 [temp.deduct]
19081 When all template arguments have been deduced, all uses of
19082 template parameters in nondeduced contexts are replaced with
19083 the corresponding deduced argument values. If the
19084 substitution results in an invalid type, as described above,
19085 type deduction fails. */
19088 {
19091 }
19093 /* Also collect access checks from the instantiation. */
19106 /* Now perform any access checks encountered during substitution. */
19113 /* If we're looking for an exact match, check that what we got
19114 is indeed an exact match. It might not be if some template
19115 parameters are used in non-deduced contexts. But don't check
19116 for an exact match if we have dependent template arguments;
19117 in that case we're doing partial ordering, and we already know
19118 that we have two candidates that will provide the actual type. */
19120 {
19124 tree sarg
19130 {
19134 }
19135 }
19137 /* After doing deduction with the inherited constructor, actually return an
19138 instantiation of the inheriting constructor. */
19144 fail:
19147 {
19149 /* Reset once we're all the way out. */
19151 }
19153 /* We can't free this if a pending_template entry or last_error_tinst_level
19154 is pointing at it. */
19160 }
19162 /* Adjust types before performing type deduction, as described in
19163 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
19164 sections are symmetric. PARM is the type of a function parameter
19165 or the return type of the conversion function. ARG is the type of
19166 the argument passed to the call, or the type of the value
19167 initialized with the result of the conversion function.
19168 ARG_EXPR is the original argument expression, which may be null. */
19170 static int
19174 tree arg_expr)
19175 {
19179 {
19184 /* Swap PARM and ARG throughout the remainder of this
19185 function; the handling is precisely symmetric since PARM
19186 will initialize ARG rather than vice versa. */
19191 /* Core issue #873: Do the DR606 thing (see below) for these cases,
19192 too, but here handle it by stripping the reference from PARM
19193 rather than by adding it to ARG. */
19201 /* Nothing else to do in this case. */
19206 }
19209 {
19210 /* [temp.deduct.call]
19212 If P is not a reference type:
19214 --If A is an array type, the pointer type produced by the
19215 array-to-pointer standard conversion (_conv.array_) is
19216 used in place of A for type deduction; otherwise,
19218 --If A is a function type, the pointer type produced by
19219 the function-to-pointer standard conversion
19220 (_conv.func_) is used in place of A for type deduction;
19221 otherwise,
19223 --If A is a cv-qualified type, the top level
19224 cv-qualifiers of A's type are ignored for type
19225 deduction. */
19230 else
19232 }
19234 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19235 reference to a cv-unqualified template parameter that does not represent a
19236 template parameter of a class template (during class template argument
19237 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19238 an lvalue, the type "lvalue reference to A" is used in place of A for type
19239 deduction. */
19246 /* try_one_overload doesn't provide an arg_expr, but
19247 functions are always lvalues. */
19251 /* [temp.deduct.call]
19253 If P is a cv-qualified type, the top level cv-qualifiers
19254 of P's type are ignored for type deduction. If P is a
19255 reference type, the type referred to by P is used for
19256 type deduction. */
19259 {
19262 }
19264 /* DR 322. For conversion deduction, remove a reference type on parm
19265 too (which has been swapped into ARG). */
19270 }
19272 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19273 template which does contain any deducible template parameters; check if
19274 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19275 unify_one_argument. */
19277 static int
19280 {
19281 tree type;
19285 else
19292 {
19296 }
19298 {
19303 }
19307 else
19309 }
19313 /* Returns true iff the expression EXPR is one from which a template
19314 argument can be deduced. In other words, if it's an undecorated
19315 use of a template non-type parameter. */
19317 static bool
19319 {
19320 /* Strip implicit conversions. */
19324 }
19326 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19327 deducible way; that is, if it has a max value of <PARM> - 1. */
19329 static bool
19331 {
19340 }
19342 /* Returns true iff the template arguments ARGS use a template parameter
19343 in a deducible way. */
19345 static bool
19347 {
19349 {
19354 else
19355 {
19362 else
19364 }
19367 }
19369 }
19371 /* Returns true iff TYPE contains any deducible references to template
19372 parameters, as per 14.8.2.5. */
19374 static bool
19376 {
19380 /* T
19381 cv-list T
19382 TT<T>
19383 TT<i>
19384 TT<> */
19389 /* T*
19390 T&
19391 T&& */
19395 /* T[integer-constant ]
19396 type [i] */
19401 /* T type ::*
19402 type T::*
19403 T T::*
19404 T (type ::*)()
19405 type (T::*)()
19406 type (type ::*)(T)
19407 type (T::*)(T)
19408 T (type ::*)(T)
19409 T (T::*)()
19410 T (T::*)(T) */
19413 || (uses_deducible_template_parms
19416 /* template-name <T> (where template-name refers to a class template)
19417 template-name <i> (where template-name refers to a class template) */
19424 /* type (T)
19425 T()
19426 T(T) */
19429 {
19438 }
19441 }
19443 /* Subroutine of type_unification_real and unify_pack_expansion to
19444 handle unification of a single P/A pair. Parameters are as
19445 for those functions. */
19447 static int
19451 {
19458 /* We can't deduce anything from this, but we might get all the
19459 template args from other function args. */
19462 /* Implicit conversions (Clause 4) will be performed on a function
19463 argument to convert it to the type of the corresponding function
19464 parameter if the parameter type contains no template-parameters that
19465 participate in template argument deduction. */
19468 /* For function parameters with no deducible template parameters,
19469 just return. We'll check non-dependent conversions later. */
19473 {
19475 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19476 | UNIFY_ALLOW_MORE_CV_QUAL
19490 }
19492 /* We only do these transformations if this is the top-level
19493 parameter_type_list in a call or declaration matching; in other
19494 situations (nested function declarators, template argument lists) we
19495 won't be comparing a type to an expression, and we don't do any type
19496 adjustments. */
19498 {
19500 {
19503 {
19504 /* [temp.deduct.type] A template-argument can be
19505 deduced from a pointer to function or pointer
19506 to member function argument if the set of
19507 overloaded functions does not contain function
19508 templates and at most one of a set of
19509 overloaded functions provides a unique
19510 match. */
19514 /* If a unique match was not found, this is a
19515 non-deduced context, so we still succeed. */
19517 }
19523 }
19525 arg_strict |=
19527 }
19528 else
19533 /* For deduction from an init-list we need the actual list. */
19537 }
19539 /* for_each_template_parm callback that always returns 0. */
19541 static int
19543 {
19545 }
19547 /* for_each_template_parm any_fn callback to handle deduction of a template
19548 type argument from the type of an array bound. */
19550 static int
19552 {
19560 {
19566 }
19568 /* Keep walking. */
19570 }
19572 /* Try to deduce any not-yet-deduced template type arguments from the type of
19573 an array bound. This is handled separately from unify because 14.8.2.5 says
19574 "The type of a type parameter is only deduced from an array bound if it is
19575 not otherwise deduced." */
19577 static void
19579 {
19584 }
19586 /* Most parms like fn_type_unification.
19588 If SUBR is 1, we're being called recursively (to unify the
19589 arguments of a function or method parameter of a function
19590 template).
19592 CHECKS is a pointer to a vector of access checks encountered while
19593 substituting default template arguments. */
19595 static int
19597 tree full_targs,
19598 tree xparms,
19602 unification_kind_t strict,
19606 {
19611 tree parms;
19622 /* Reset the number of non-defaulted template arguments contained
19623 in TARGS. */
19626 again:
19634 {
19639 /* For a function parameter pack that occurs at the end of the
19640 parameter-declaration-list, the type A of each remaining
19641 argument of the call is compared with the type P of the
19642 declarator-id of the function parameter pack. */
19648 /* For a function parameter pack that does not occur at the
19649 end of the parameter-declaration-list, the type of the
19650 parameter pack is a non-deduced context. */
19657 explain_p))
19659 }
19664 {
19665 /* Unify the remaining arguments with the pack expansion type. */
19666 tree argvec;
19669 /* Allocate a TREE_VEC and copy in all of the arguments */
19674 /* Copy the parameter into parmvec. */
19680 /* Advance to the end of the list of parameters. */
19682 }
19684 /* Fail if we've reached the end of the parm list, and more args
19685 are present, and the parm list isn't variadic. */
19688 /* Fail if parms are left and they don't have default values and
19689 they aren't all deduced as empty packs (c++/57397). This is
19690 consistent with sufficient_parms_p. */
19693 {
19697 do
19698 {
19701 count++;
19703 }
19707 type_pack_p);
19708 }
19711 {
19712 tsubst_flags_t complain = (explain_p
19713 ? tf_warning_or_error
19718 {
19722 /* Clear the "incomplete" flags on all argument packs now so that
19723 substituting them into later default arguments works. */
19725 {
19728 }
19736 {
19741 }
19743 /* If this is an undeduced nontype parameter that depends on
19744 a type parameter, try another pass; its type may have been
19745 deduced from a later argument than the one from which
19746 this parameter can be deduced. */
19750 {
19753 }
19755 /* Core issue #226 (C++0x) [temp.deduct]:
19757 If a template argument has not been deduced, its
19758 default template argument, if any, is used.
19760 When we are in C++98 mode, TREE_PURPOSE will either
19761 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19762 to explicitly check cxx_dialect here. */
19764 /* OK, there is a default argument. Wait until after the
19765 conversion check to do substitution. */
19768 /* If the type parameter is a parameter pack, then it will
19769 be deduced to an empty parameter pack. */
19771 {
19772 tree arg;
19775 {
19778 }
19779 else
19786 }
19789 }
19791 /* DR 1391: All parameters have args, now check non-dependent parms for
19792 convertibility. */
19796 {
19802 /* For a function parameter pack that occurs at the end of the
19803 parameter-declaration-list, the type A of each remaining
19804 argument of the call is compared with the type P of the
19805 declarator-id of the function parameter pack. */
19811 /* For a function parameter pack that does not occur at the
19812 end of the parameter-declaration-list, the type of the
19813 parameter pack is a non-deduced context. */
19822 explain_p))
19824 }
19826 /* Now substitute into the default template arguments. */
19828 {
19852 else
19860 {
19862 /* The position of the first default template argument,
19863 is also the number of non-defaulted arguments in TARGS.
19864 Record that. */
19867 }
19868 }
19872 }
19878 }
19880 /* Subroutine of type_unification_real. Args are like the variables
19881 at the call site. ARG is an overloaded function (or template-id);
19882 we try deducing template args from each of the overloads, and if
19883 only one succeeds, we go with that. Modifies TARGS and returns
19884 true on success. */
19886 static bool
19888 tree targs,
19889 tree parm,
19890 tree arg,
19891 unification_kind_t strict,
19894 {
19901 {
19904 }
19905 else
19909 /* Handle `&x' where `x' is some static or non-static member
19910 function name. */
19916 /* Strip baselink information. */
19921 {
19922 /* If we got some explicit template args, we need to plug them into
19923 the affected templates before we try to unify, in case the
19924 explicit args will completely resolve the templates in question. */
19931 {
19944 {
19949 {
19952 }
19953 }
19956 }
19957 /* If no templates (or more than one) are fully resolved by the
19958 explicit arguments, this template-id is a non-deduced context; it
19959 could still be OK if we deduce all template arguments for the
19960 enclosing call through other arguments. */
19963 }
19966 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19967 -- but the deduction does not succeed because the expression is
19968 not just the function on its own. */
19970 else
19972 {
19977 {
19980 }
19981 }
19983 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19984 to function or pointer to member function argument if the set of
19985 overloaded functions does not contain function templates and at most
19986 one of a set of overloaded functions provides a unique match.
19988 So if we found multiple possibilities, we return success but don't
19989 deduce anything. */
19992 {
19996 {
20001 /* Don't forget explicit template arguments in a pack. */
20005 }
20006 }
20011 }
20013 /* Core DR 115: In contexts where deduction is done and fails, or in
20014 contexts where deduction is not done, if a template argument list is
20015 specified and it, along with any default template arguments, identifies
20016 a single function template specialization, then the template-id is an
20017 lvalue for the function template specialization. */
20019 tree
20021 {
20034 {
20037 }
20039 {
20042 }
20044 {
20047 }
20050 {
20054 /* If we got some explicit template args, we need to plug them into
20055 the affected templates before we try to unify, in case the
20056 explicit args will completely resolve the templates in question. */
20064 {
20077 {
20080 {
20083 }
20085 {
20088 }
20089 }
20090 }
20092 {
20100 {
20101 tree base
20104 }
20108 }
20110 /* There were no good options and at least one bad one, so let the
20111 user know what the problem is. */
20113 }
20115 }
20117 /* Subroutine of resolve_overloaded_unification; does deduction for a single
20118 overload. Fills TARGS with any deduced arguments, or error_mark_node if
20119 different overloads deduce different arguments for a given parm.
20120 ADDR_P is true if the expression for which deduction is being
20121 performed was of the form "& fn" rather than simply "fn".
20123 Returns 1 on success. */
20125 static int
20127 tree orig_targs,
20128 tree targs,
20129 tree parm,
20130 tree arg,
20131 unification_kind_t strict,
20135 {
20137 tree tempargs;
20143 /* [temp.deduct.type] A template-argument can be deduced from a pointer
20144 to function or pointer to member function argument if the set of
20145 overloaded functions does not contain function templates and at most
20146 one of a set of overloaded functions provides a unique match.
20148 So if this is a template, just return success. */
20160 /* We don't copy orig_targs for this because if we have already deduced
20161 some template args from previous args, unify would complain when we
20162 try to deduce a template parameter for the same argument, even though
20163 there isn't really a conflict. */
20170 /* First make sure we didn't deduce anything that conflicts with
20171 explicitly specified args. */
20173 {
20180 /* Since we're unifying against ourselves, we will fill in
20181 template args used in the function parm list with our own
20182 template parms. Discard them. */
20185 {
20186 /* Check that the argument at each index of the deduced argument pack
20187 is equivalent to the corresponding explicitly specified argument.
20188 We may have deduced more arguments than were explicitly specified,
20189 and that's OK. */
20191 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
20192 that's wrong if we deduce the same argument pack from multiple
20193 function arguments: it's only incomplete the first time. */
20206 }
20209 }
20212 {
20217 }
20220 }
20222 /* PARM is a template class (perhaps with unbound template
20223 parameters). ARG is a fully instantiated type. If ARG can be
20224 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20225 TARGS are as for unify. */
20227 static tree
20230 {
20231 tree copy_of_targs;
20241 /* We need to make a new template argument vector for the call to
20242 unify. If we used TARGS, we'd clutter it up with the result of
20243 the attempted unification, even if this class didn't work out.
20244 We also don't want to commit ourselves to all the unifications
20245 we've already done, since unification is supposed to be done on
20246 an argument-by-argument basis. In other words, consider the
20247 following pathological case:
20249 template <int I, int J, int K>
20250 struct S {};
20252 template <int I, int J>
20253 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20255 template <int I, int J, int K>
20256 void f(S<I, J, K>, S<I, I, I>);
20258 void g() {
20259 S<0, 0, 0> s0;
20260 S<0, 1, 2> s2;
20262 f(s0, s2);
20263 }
20265 Now, by the time we consider the unification involving `s2', we
20266 already know that we must have `f<0, 0, 0>'. But, even though
20267 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20268 because there are two ways to unify base classes of S<0, 1, 2>
20269 with S<I, I, I>. If we kept the already deduced knowledge, we
20270 would reject the possibility I=1. */
20274 {
20278 }
20280 /* If unification failed, we're done. */
20286 }
20288 /* Given a template type PARM and a class type ARG, find the unique
20289 base type in ARG that is an instance of PARM. We do not examine
20290 ARG itself; only its base-classes. If there is not exactly one
20291 appropriate base class, return NULL_TREE. PARM may be the type of
20292 a partial specialization, as well as a plain template type. Used
20293 by unify. */
20295 static enum template_base_result
20298 {
20300 tree binfo;
20306 {
20307 /* The type could not be completed. */
20310 }
20312 /* Walk in inheritance graph order. The search order is not
20313 important, and this avoids multiple walks of virtual bases. */
20315 {
20320 {
20321 /* If there is more than one satisfactory baseclass, then:
20323 [temp.deduct.call]
20325 If they yield more than one possible deduced A, the type
20326 deduction fails.
20328 applies. */
20330 {
20333 }
20336 }
20337 }
20341 }
20343 /* Returns the level of DECL, which declares a template parameter. */
20345 static int
20347 {
20349 {
20359 }
20361 }
20363 /* Decide whether ARG can be unified with PARM, considering only the
20364 cv-qualifiers of each type, given STRICT as documented for unify.
20365 Returns nonzero iff the unification is OK on that basis. */
20367 static int
20369 {
20375 {
20376 /* Although a CVR qualifier is ignored when being applied to a
20377 substituted template parameter ([8.3.2]/1 for example), that
20378 does not allow us to unify "const T" with "int&" because both
20379 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20380 It is ok when we're allowing additional CV qualifiers
20381 at the outer level [14.8.2.1]/3,1st bullet. */
20391 }
20402 }
20404 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20405 void
20407 {
20411 {
20414 }
20415 else
20416 {
20419 }
20420 }
20422 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20423 do { \
20424 if (unify (TP, TA, P, A, S, EP)) \
20425 return 1; \
20426 } while (0)
20428 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20429 expansion at the end of PACKED_PARMS. Returns 0 if the type
20430 deduction succeeds, 1 otherwise. STRICT is the same as in
20431 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20432 function call argument list. We'll need to adjust the arguments to make them
20433 types. SUBR tells us if this is from a recursive call to
20434 type_unification_real, or for comparing two template argument
20435 lists. */
20437 static int
20441 {
20442 tree parm
20448 /* Add in any args remembered from an earlier partial instantiation. */
20456 /* Determine the parameter packs we will be deducing from the
20457 pattern, and record their current deductions. */
20460 {
20464 /* Determine the index and level of this parameter pack. */
20469 /* Keep track of the parameter packs and their corresponding
20470 argument packs. */
20473 }
20475 /* Loop through all of the arguments that have not yet been
20476 unified and unify each with the pattern. */
20478 {
20479 tree parm;
20483 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20484 or the element of its argument pack at the current index if
20485 this argument was explicitly specified. */
20487 {
20496 {
20499 }
20501 }
20503 /* If we had explicit template arguments, substitute them into the
20504 pattern before deduction. */
20506 {
20507 /* Some arguments might still be unspecified or dependent. */
20515 NULL_TREE);
20520 }
20521 else
20524 /* Unify the pattern with the current argument. */
20526 explain_p))
20529 /* For each parameter pack, collect the deduced value. */
20531 {
20537 }
20538 }
20540 /* Verify that the results of unification with the parameter packs
20541 produce results consistent with what we've seen before, and make
20542 the deduced argument packs available. */
20544 {
20551 /* By default keep the original deduced argument pack.
20552 If necessary, more specific code is going to update the
20553 resulting deduced argument later down in this function. */
20557 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20558 actually deduce anything. */
20566 {
20567 /* If we had fewer function args than explicit template args,
20568 just use the explicits. */
20573 }
20576 {
20577 tree result;
20578 /* Build the deduced *_ARGUMENT_PACK. */
20580 {
20583 }
20584 else
20589 /* Note the deduced argument packs for this parameter
20590 pack. */
20592 }
20596 {
20597 /* We only had the explicitly-provided arguments before, but
20598 now we have a complete set of arguments. */
20604 }
20605 else
20606 {
20612 /* Inconsistent unification of this parameter pack. */
20614 bad_old_arg,
20615 bad_new_arg);
20616 }
20617 }
20620 }
20622 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20623 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20624 parameters and return value are as for unify. */
20626 static int
20630 {
20631 tree parm_max;
20632 tree arg_max;
20636 /* Our representation of array types uses "N - 1" as the
20637 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20638 not an integer constant. We cannot unify arbitrarily
20639 complex expressions, so we eliminate the MINUS_EXPRs
20640 here. */
20644 {
20647 }
20651 {
20652 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20653 trying to unify the type of a variable with the type
20654 of a template parameter. For example:
20656 template <unsigned int N>
20657 void f (char (&) [N]);
20658 int g();
20659 void h(int i) {
20660 char a[g(i)];
20661 f(a);
20662 }
20664 Here, the type of the ARG will be "int [g(i)]", and
20665 may be a SAVE_EXPR, etc. */
20669 }
20671 /* If only one of the bounds used a MINUS_EXPR, compensate
20672 by adding one to the other bound. */
20675 integer_type_node,
20676 parm_max,
20677 integer_one_node);
20680 integer_type_node,
20681 arg_max,
20682 integer_one_node);
20686 }
20688 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20692 static pa_kind_t
20694 {
20703 else
20705 }
20707 /* Deduce the value of template parameters. TPARMS is the (innermost)
20708 set of template parameters to a template. TARGS is the bindings
20709 for those template parameters, as determined thus far; TARGS may
20710 include template arguments for outer levels of template parameters
20711 as well. PARM is a parameter to a template function, or a
20712 subcomponent of that parameter; ARG is the corresponding argument.
20713 This function attempts to match PARM with ARG in a manner
20714 consistent with the existing assignments in TARGS. If more values
20715 are deduced, then TARGS is updated.
20717 Returns 0 if the type deduction succeeds, 1 otherwise. The
20718 parameter STRICT is a bitwise or of the following flags:
20720 UNIFY_ALLOW_NONE:
20721 Require an exact match between PARM and ARG.
20722 UNIFY_ALLOW_MORE_CV_QUAL:
20723 Allow the deduced ARG to be more cv-qualified (by qualification
20724 conversion) than ARG.
20725 UNIFY_ALLOW_LESS_CV_QUAL:
20726 Allow the deduced ARG to be less cv-qualified than ARG.
20727 UNIFY_ALLOW_DERIVED:
20728 Allow the deduced ARG to be a template base class of ARG,
20729 or a pointer to a template base class of the type pointed to by
20730 ARG.
20731 UNIFY_ALLOW_INTEGER:
20732 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20733 case for more information.
20734 UNIFY_ALLOW_OUTER_LEVEL:
20735 This is the outermost level of a deduction. Used to determine validity
20736 of qualification conversions. A valid qualification conversion must
20737 have const qualified pointers leading up to the inner type which
20738 requires additional CV quals, except at the outer level, where const
20739 is not required [conv.qual]. It would be normal to set this flag in
20740 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20741 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20742 This is the outermost level of a deduction, and PARM can be more CV
20743 qualified at this point.
20744 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20745 This is the outermost level of a deduction, and PARM can be less CV
20746 qualified at this point. */
20748 static int
20751 {
20753 tree targ;
20754 tree tparm;
20756 tsubst_flags_t complain = (explain_p
20757 ? tf_warning_or_error
20760 /* I don't think this will do the right thing with respect to types.
20761 But the only case I've seen it in so far has been array bounds, where
20762 signedness is the only information lost, and I think that will be
20763 okay. */
20771 /* We can't deduce anything from this, but we might get all the
20772 template args from other function args. */
20778 /* If PARM uses template parameters, then we can't bail out here,
20779 even if ARG == PARM, since we won't record unifications for the
20780 template parameters. We might need them if we're trying to
20781 figure out which of two things is more specialized. */
20785 /* Handle init lists early, so the rest of the function can assume
20786 we're dealing with a type. */
20788 {
20793 /* Replace T with std::initializer_list<T> for deduction. */
20800 /* We can only deduce from an initializer list argument if the
20801 parameter is std::initializer_list or an array; otherwise this
20802 is a non-deduced context. */
20807 else
20808 {
20810 /* Deduction is defined in terms of a single type, so just punt
20811 on the (bizarre) std::initializer_list<T...>. */
20814 }
20817 {
20824 {
20828 /* It should only be possible to get here for a call. */
20830 elt_strict |= maybe_adjust_types_for_deduction
20833 }
20836 explain_p);
20837 }
20841 {
20842 /* Also deduce from the length of the initializer list. */
20849 }
20851 /* If the std::initializer_list<T> deduction worked, replace the
20852 deduced A with std::initializer_list<A>. */
20854 {
20859 }
20861 }
20863 /* If parm and arg aren't the same kind of thing (template, type, or
20864 expression), fail early. */
20868 /* Immediately reject some pairs that won't unify because of
20869 cv-qualification mismatches. */
20872 /* It is the elements of the array which hold the cv quals of an array
20873 type, and the elements might be template type parms. We'll check
20874 when we recurse. */
20876 /* We check the cv-qualifiers when unifying with template type
20877 parameters below. We want to allow ARG `const T' to unify with
20878 PARM `T' for example, when computing which of two templates
20879 is more specialized, for example. */
20893 {
20897 /* In a type which contains a nested-name-specifier, template
20898 argument values cannot be deduced for template parameters used
20899 within the nested-name-specifier. */
20911 /* The PARM is not one we're trying to unify. Just check
20912 to see if it matches ARG. */
20913 {
20918 else
20920 }
20927 /* Check for mixed types and values. */
20935 {
20938 {
20939 /* First try to match ARG directly. */
20941 explain_p);
20943 {
20944 /* Otherwise, look for a suitable base of ARG, as below. */
20951 }
20952 }
20953 /* ARG must be constructed from a template class or a template
20954 template parameter. */
20959 /* Deduce arguments T, i from TT<T> or TT<i>. */
20965 /* Fall through to deduce template name. */
20966 }
20970 {
20971 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20973 /* Simple cases: Value already set, does match or doesn't. */
20978 }
20979 else
20980 {
20981 /* If PARM is `const T' and ARG is only `int', we don't have
20982 a match unless we are allowing additional qualification.
20983 If ARG is `const int' and PARM is just `T' that's OK;
20984 that binds `const int' to `T'. */
20989 /* Consider the case where ARG is `const volatile int' and
20990 PARM is `const T'. Then, T should be `volatile int'. */
20991 arg = cp_build_qualified_type_real
20996 /* Simple cases: Value already set, does match or doesn't. */
21002 /* Make sure that ARG is not a variable-sized array. (Note
21003 that were talking about variable-sized arrays (like
21004 `int[n]'), rather than arrays of unknown size (like
21005 `int[]').) We'll get very confused by such a type since
21006 the bound of the array is not constant, and therefore
21007 not mangleable. Besides, such types are not allowed in
21008 ISO C++, so we can do as we please here. We do allow
21009 them for 'auto' deduction, since that isn't ABI-exposed. */
21013 /* Strip typedefs as in convert_template_argument. */
21015 }
21017 /* If ARG is a parameter pack or an expansion, we cannot unify
21018 against it unless PARM is also a parameter pack. */
21023 /* If the argument deduction results is a METHOD_TYPE,
21024 then there is a problem.
21025 METHOD_TYPE doesn't map to any real C++ type the result of
21026 the deduction can not be of that type. */
21040 {
21041 /* The PARM is not one we're trying to unify. Just check
21042 to see if it matches ARG. */
21048 }
21054 {
21058 /* We're deducing from an array bound, the type doesn't matter. */
21064 }
21066 /* [temp.deduct.type] If, in the declaration of a function template
21067 with a non-type template-parameter, the non-type
21068 template-parameter is used in an expression in the function
21069 parameter-list and, if the corresponding template-argument is
21070 deduced, the template-argument type shall match the type of the
21071 template-parameter exactly, except that a template-argument
21072 deduced from an array bound may be of any integral type.
21073 The non-type parameter might use already deduced type parameters. */
21078 {
21082 }
21085 /* Template-parameter dependent expression. Just accept it for now.
21086 It will later be processed in convert_template_argument. */
21087 ;
21093 /* Convert the ARG to the type of PARM; the deduced non-type
21094 template argument must exactly match the types of the
21095 corresponding parameter. */
21098 {
21099 /* We haven't deduced the type of this parameter yet. */
21101 /* We deduce from array bounds in try_array_deduction. */
21103 {
21104 /* Deduce it from the non-type argument. */
21109 }
21110 else
21111 /* Try again later. */
21113 }
21114 else
21117 /* If ARG is a parameter pack or an expansion, we cannot unify
21118 against it unless PARM is also a parameter pack. */
21123 {
21126 }
21131 {
21132 /* A pointer-to-member constant can be unified only with
21133 another constant. */
21137 /* Just unify the class member. It would be useless (and possibly
21138 wrong, depending on the strict flags) to unify also
21139 PTRMEM_CST_CLASS, because we want to be sure that both parm and
21140 arg refer to the same variable, even if through different
21141 classes. For instance:
21143 struct A { int x; };
21144 struct B : A { };
21146 Unification of &A::x and &B::x must succeed. */
21149 }
21152 {
21156 /* [temp.deduct.call]
21158 A can be another pointer or pointer to member type that can
21159 be converted to the deduced A via a qualification
21160 conversion (_conv.qual_).
21162 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
21163 This will allow for additional cv-qualification of the
21164 pointed-to types if appropriate. */
21167 /* The derived-to-base conversion only persists through one
21168 level of pointers. */
21173 }
21205 /* We have already checked cv-qualification at the top of the
21206 function. */
21210 /* As far as unification is concerned, this wins. Later checks
21211 will invalidate it if necessary. */
21214 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21215 /* Type INTEGER_CST can come from ordinary constant template args. */
21227 {
21237 /* Check for pack expansions in the parameters. */
21239 {
21241 {
21243 /* We can unify against something with a trailing
21244 parameter pack. */
21246 else
21247 /* [temp.deduct.type]/9: If the template argument list of
21248 P contains a pack expansion that is not the last
21249 template argument, the entire template argument list
21250 is a non-deduced context. */
21252 }
21253 }
21255 /* If we don't have enough arguments to satisfy the parameters
21256 (not counting the pack expression at the end), or we have
21257 too many arguments for a parameter list that doesn't end in
21258 a pack expression, we can't unify. */
21264 /* Unify all of the parameters that precede the (optional)
21265 pack expression. */
21267 {
21272 }
21275 DEDUCE_EXACT,
21278 }
21286 {
21294 }
21299 {
21303 {
21304 /* First, we try to unify the PARM and ARG directly. */
21309 {
21310 /* Fallback to the special case allowed in
21311 [temp.deduct.call]:
21313 If P is a class, and P has the form
21314 template-id, then A can be a derived class of
21315 the deduced A. Likewise, if P is a pointer to
21316 a class of the form template-id, A can be a
21317 pointer to a derived class pointed to by the
21318 deduced A. */
21324 {
21325 /* Don't give the derived diagnostic if we're
21326 already dealing with the same template. */
21327 bool same_template
21333 }
21334 }
21335 }
21339 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21340 Then, we should unify `int' and `U'. */
21342 else
21343 /* There's no chance of unification succeeding. */
21348 }
21355 {
21358 tree a;
21364 /* CV qualifications for methods can never be deduced, they must
21365 match exactly. We need to check them explicitly here,
21366 because type_unification_real treats them as any other
21367 cv-qualified parameter. */
21369 && (!check_cv_quals_for_unify
21397 {
21409 }
21412 }
21415 /* Unify a pointer to member with a pointer to member function, which
21416 deduces the type of the member as a function type. */
21418 {
21419 /* Check top-level cv qualifiers */
21427 /* Determine the type of the function we are unifying against. */
21431 }
21450 /* Matched cases are handled by the ARG == PARM test above. */
21454 /* We might get a variable as a non-type template argument in parm if the
21455 corresponding parameter is type-dependent. Make any necessary
21456 adjustments based on whether arg is a reference. */
21460 {
21465 }
21466 /* Now use the normal expression code to check whether they match. */
21477 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21478 or UNDERLYING_TYPE nodes. */
21482 /* Unification fails if we hit an error node. */
21487 {
21497 }
21498 /* FALLTHRU */
21501 /* An unresolved overload is a nondeduced context. */
21505 expr:
21506 /* We must be looking at an expression. This can happen with
21507 something like:
21509 template <int I>
21510 void foo(S<I>, S<I + 2>);
21512 This is a "nondeduced context":
21514 [deduct.type]
21516 The nondeduced contexts are:
21518 --A type that is a template-id in which one or more of
21519 the template-arguments is an expression that references
21520 a template-parameter.
21522 In these cases, we assume deduction succeeded, but don't
21523 actually infer any unifications. */
21528 else
21530 }
21531 }
21532 #undef RECUR_AND_CHECK_FAILURE
21533 \f
21534 /* Note that DECL can be defined in this translation unit, if
21535 required. */
21537 static void
21539 {
21540 tree clone;
21544 }
21546 /* Called if RESULT is explicitly instantiated, or is a member of an
21547 explicitly instantiated class. */
21549 void
21551 {
21554 /* If this entity has already been written out, it's too late to
21555 make any modifications. */
21559 /* For anonymous namespace we don't need to do anything. */
21561 {
21564 }
21567 /* The TREE_PUBLIC flag for function declarations will have been
21568 set correctly by tsubst. */
21571 /* This might have been set by an earlier implicit instantiation. */
21576 else
21577 {
21580 /* Always make artificials weak. */
21583 /* For WIN32 we also want to put explicit instantiations in
21584 linkonce sections. */
21587 }
21589 /* If EXTERN_P, then this function will not be emitted -- unless
21590 followed by an explicit instantiation, at which point its linkage
21591 will be adjusted. If !EXTERN_P, then this function will be
21592 emitted here. In neither circumstance do we want
21593 import_export_decl to adjust the linkage. */
21595 }
21597 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21598 important template arguments. If any are missing, we check whether
21599 they're important by using error_mark_node for substituting into any
21600 args that were used for partial ordering (the ones between ARGS and END)
21601 and seeing if it bubbles up. */
21603 static bool
21605 {
21610 {
21613 }
21615 {
21619 }
21621 }
21623 /* Given two function templates PAT1 and PAT2, return:
21625 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21626 -1 if PAT2 is more specialized than PAT1.
21627 0 if neither is more specialized.
21629 LEN indicates the number of parameters we should consider
21630 (defaulted parameters should not be considered).
21632 The 1998 std underspecified function template partial ordering, and
21633 DR214 addresses the issue. We take pairs of arguments, one from
21634 each of the templates, and deduce them against each other. One of
21635 the templates will be more specialized if all the *other*
21636 template's arguments deduce against its arguments and at least one
21637 of its arguments *does* *not* deduce against the other template's
21638 corresponding argument. Deduction is done as for class templates.
21639 The arguments used in deduction have reference and top level cv
21640 qualifiers removed. Iff both arguments were originally reference
21641 types *and* deduction succeeds in both directions, an lvalue reference
21642 wins against an rvalue reference and otherwise the template
21643 with the more cv-qualified argument wins for that pairing (if
21644 neither is more cv-qualified, they both are equal). Unlike regular
21645 deduction, after all the arguments have been deduced in this way,
21646 we do *not* verify the deduced template argument values can be
21647 substituted into non-deduced contexts.
21649 The logic can be a bit confusing here, because we look at deduce1 and
21650 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21651 can find template arguments for pat1 to make arg1 look like arg2, that
21652 means that arg2 is at least as specialized as arg1. */
21654 int
21656 {
21669 /* Remove the this parameter from non-static member functions. If
21670 one is a non-static member function and the other is not a static
21671 member function, remove the first parameter from that function
21672 also. This situation occurs for operator functions where we
21673 locate both a member function (with this pointer) and non-member
21674 operator (with explicit first operand). */
21676 {
21681 }
21683 {
21686 {
21687 len--;
21689 }
21690 }
21692 /* If only one is a conversion operator, they are unordered. */
21696 /* Consider the return type for a conversion function */
21698 {
21701 len++;
21702 }
21704 processing_template_decl++;
21710 /* Stop when an ellipsis is seen. */
21712 {
21723 {
21724 /* When both arguments are pack expansions, we need only
21725 unify the patterns themselves. */
21729 /* This is the last comparison we need to do. */
21731 }
21733 /* DR 1847: If a particular P contains no template-parameters that
21734 participate in template argument deduction, that P is not used to
21735 determine the ordering. */
21741 {
21745 }
21748 {
21752 }
21758 {
21764 /* Setup the parameter vector, which contains only ARG1. */
21767 /* Setup the argument vector, which contains the remaining
21768 arguments. */
21777 /* We cannot deduce in the other direction, because ARG1 is
21778 a pack expansion but ARG2 is not. */
21780 }
21782 {
21788 /* Setup the parameter vector, which contains only ARG1. */
21791 /* Setup the argument vector, which contains the remaining
21792 arguments. */
21801 /* We cannot deduce in the other direction, because ARG2 is
21802 a pack expansion but ARG1 is not.*/
21804 }
21806 else
21807 {
21808 /* The normal case, where neither argument is a pack
21809 expansion. */
21816 }
21818 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21819 arg2, then arg2 is not as specialized as arg1. */
21825 /* "If, for a given type, deduction succeeds in both directions
21826 (i.e., the types are identical after the transformations above)
21827 and both P and A were reference types (before being replaced with
21828 the type referred to above):
21829 - if the type from the argument template was an lvalue reference and
21830 the type from the parameter template was not, the argument type is
21831 considered to be more specialized than the other; otherwise,
21832 - if the type from the argument template is more cv-qualified
21833 than the type from the parameter template (as described above),
21834 the argument type is considered to be more specialized than the other;
21835 otherwise,
21836 - neither type is more specialized than the other." */
21839 {
21841 {
21844 else
21846 }
21848 {
21853 }
21854 }
21857 /* We've failed to deduce something in either direction.
21858 These must be unordered. */
21861 next:
21865 /* We have already processed all of the arguments in our
21866 handing of the pack expansion type. */
21871 }
21873 /* "In most cases, all template parameters must have values in order for
21874 deduction to succeed, but for partial ordering purposes a template
21875 parameter may remain without a value provided it is not used in the
21876 types being used for partial ordering."
21878 Thus, if we are missing any of the targs1 we need to substitute into
21879 origs1, then pat2 is not as specialized as pat1. This can happen when
21880 there is a nondeduced context. */
21886 processing_template_decl--;
21888 /* If both deductions succeed, the partial ordering selects the more
21889 constrained template. */
21891 {
21896 }
21898 /* All things being equal, if the next argument is a pack expansion
21899 for one function but not for the other, prefer the
21900 non-variadic function. FIXME this is bogus; see c++/41958. */
21904 {
21907 }
21913 else
21915 }
21917 /* Determine which of two partial specializations of TMPL is more
21918 specialized.
21920 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21921 to the first partial specialization. The TREE_PURPOSE is the
21922 innermost set of template parameters for the partial
21923 specialization. PAT2 is similar, but for the second template.
21925 Return 1 if the first partial specialization is more specialized;
21926 -1 if the second is more specialized; 0 if neither is more
21927 specialized.
21929 See [temp.class.order] for information about determining which of
21930 two templates is more specialized. */
21932 static int
21934 {
21935 tree targs;
21944 /* Just like what happens for functions, if we are ordering between
21945 different template specializations, we may encounter dependent
21946 types in the arguments, and we need our dependency check functions
21947 to behave correctly. */
21951 {
21954 }
21958 {
21961 }
21964 /* If both deductions succeed, the partial ordering selects the more
21965 constrained template. */
21969 /* In the case of a tie where at least one of the templates
21970 has a parameter pack at the end, the template with the most
21971 non-packed parameters wins. */
21973 && any_deductions
21976 {
21982 /* We don't count the pack expansion at the end. */
21992 }
21995 }
21997 /* Return the template arguments that will produce the function signature
21998 DECL from the function template FN, with the explicit template
21999 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
22000 also match. Return NULL_TREE if no satisfactory arguments could be
22001 found. */
22003 static tree
22005 {
22009 tree decl_arg_types;
22012 tree arg;
22016 /* Never do unification on the 'this' parameter. */
22037 }
22039 /* Return the innermost template arguments that, when applied to a partial
22040 specialization SPEC_TMPL of TMPL, yield the ARGS.
22042 For example, suppose we have:
22044 template <class T, class U> struct S {};
22045 template <class T> struct S<T*, int> {};
22047 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
22048 partial specialization and the ARGS will be {double*, int}. The resulting
22049 vector will be {double}, indicating that `T' is bound to `double'. */
22051 static tree
22053 {
22055 tree spec_args
22058 tree deduced_args;
22059 tree innermost_deduced_args;
22063 {
22067 innermost_deduced_args);
22068 }
22069 else
22073 again:
22082 {
22084 {
22090 }
22092 }
22096 {
22099 }
22101 /* Verify that nondeduced template arguments agree with the type
22102 obtained from argument deduction.
22104 For example:
22106 struct A { typedef int X; };
22107 template <class T, class U> struct C {};
22108 template <class T> struct C<T, typename T::X> {};
22110 Then with the instantiation `C<A, int>', we can deduce that
22111 `T' is `A' but unify () does not check whether `typename T::X'
22112 is `int'. */
22123 /* We only need to check the innermost arguments; the other
22124 arguments will always agree. */
22129 /* Now that we have bindings for all of the template arguments,
22130 ensure that the arguments deduced for the template template
22131 parameters have compatible template parameter lists. See the use
22132 of template_template_parm_bindings_ok_p in fn_type_unification
22133 for more information. */
22138 }
22140 // Compare two function templates T1 and T2 by deducing bindings
22141 // from one against the other. If both deductions succeed, compare
22142 // constraints to see which is more constrained.
22143 static int
22145 {
22150 {
22153 }
22156 {
22159 }
22161 // If both deductions succeed, then one may be more constrained.
22166 }
22168 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
22169 Return the TREE_LIST node with the most specialized template, if
22170 any. If there is no most specialized template, the error_mark_node
22171 is returned.
22173 Note that this function does not look at, or modify, the
22174 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
22175 returned is one of the elements of INSTANTIATIONS, callers may
22176 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
22177 and retrieve it from the value returned. */
22179 tree
22181 {
22188 {
22194 {
22195 /* Equally specialized, move to next function. If there
22196 is no next function, nothing's most specialized. */
22201 }
22202 }
22205 /* Now verify that champ is better than everything earlier in the
22206 instantiation list. */
22209 {
22212 }
22213 }
22215 processing_template_decl--;
22221 }
22223 /* If DECL is a specialization of some template, return the most
22224 general such template. Otherwise, returns NULL_TREE.
22226 For example, given:
22228 template <class T> struct S { template <class U> void f(U); };
22230 if TMPL is `template <class U> void S<int>::f(U)' this will return
22231 the full template. This function will not trace past partial
22232 specializations, however. For example, given in addition:
22234 template <class T> struct S<T*> { template <class U> void f(U); };
22236 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22237 `template <class T> template <class U> S<T*>::f(U)'. */
22239 tree
22241 {
22243 {
22246 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22247 template friend, or a FIELD_DECL for a capture pack. */
22250 }
22252 /* Look for more and more general templates. */
22254 {
22255 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22256 (See cp-tree.h for details.) */
22265 /* Stop if we run into an explicitly specialized class template. */
22272 }
22275 }
22277 /* Return the most specialized of the template partial specializations
22278 which can produce TARGET, a specialization of some class or variable
22279 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22280 a TEMPLATE_DECL node corresponding to the partial specialization, while
22281 the TREE_PURPOSE is the set of template arguments that must be
22282 substituted into the template pattern in order to generate TARGET.
22284 If the choice of partial specialization is ambiguous, a diagnostic
22285 is issued, and the error_mark_node is returned. If there are no
22286 partial specializations matching TARGET, then NULL_TREE is
22287 returned, indicating that the primary template should be used. */
22289 static tree
22291 {
22293 tree t;
22294 tree champ;
22301 {
22305 }
22307 {
22310 }
22312 {
22316 }
22317 else
22322 /* For determining which partial specialization to use, only the
22323 innermost args are interesting. */
22325 {
22328 }
22331 {
22332 tree spec_args;
22336 {
22337 /* Substitute in the template args from the enclosing class. */
22341 }
22348 {
22352 /* Keep the candidate only if the constraints are satisfied,
22353 or if we're not compiling with concepts. */
22356 {
22359 }
22360 }
22361 }
22371 {
22374 ;
22375 else
22376 {
22378 {
22381 {
22384 }
22385 }
22387 }
22388 }
22392 {
22395 {
22398 }
22399 }
22402 {
22409 else
22413 {
22418 }
22421 }
22424 }
22426 /* Explicitly instantiate DECL. */
22428 void
22430 {
22435 /* An error occurred, for which grokdeclarator has already issued
22436 an appropriate message. */
22439 {
22442 }
22448 {
22449 /* There is an asymmetry here in the way VAR_DECLs and
22450 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22451 the latter, the DECL we get back will be marked as a
22452 template instantiation, and the appropriate
22453 DECL_TEMPLATE_INFO will be set up. This does not happen for
22454 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22455 should handle VAR_DECLs as it currently handles
22456 FUNCTION_DECLs. */
22458 {
22461 }
22464 {
22467 }
22469 {
22474 }
22475 }
22477 {
22480 }
22481 else
22484 /* Check for various error cases. Note that if the explicit
22485 instantiation is valid the RESULT will currently be marked as an
22486 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22487 until we get here. */
22490 {
22491 /* DR 259 [temp.spec].
22493 Both an explicit instantiation and a declaration of an explicit
22494 specialization shall not appear in a program unless the explicit
22495 instantiation follows a declaration of the explicit specialization.
22497 For a given set of template parameters, if an explicit
22498 instantiation of a template appears after a declaration of an
22499 explicit specialization for that template, the explicit
22500 instantiation has no effect. */
22502 }
22504 {
22505 /* [temp.spec]
22507 No program shall explicitly instantiate any template more
22508 than once.
22510 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22511 the first instantiation was `extern' and the second is not,
22512 and EXTERN_P for the opposite case. */
22515 /* If an "extern" explicit instantiation follows an ordinary
22516 explicit instantiation, the template is instantiated. */
22519 }
22521 {
22524 }
22526 {
22529 }
22532 ;
22534 {
22537 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22540 }
22541 else
22549 }
22551 static void
22553 {
22559 {
22562 }
22563 }
22565 /* Called from do_type_instantiation through binding_table_foreach to
22566 do recursive instantiation for the type bound in ENTRY. */
22567 static void
22569 {
22575 }
22577 /* Perform an explicit instantiation of template class T. STORAGE, if
22578 non-null, is the RID for extern, inline or static. COMPLAIN is
22579 nonzero if this is called from the parser, zero if called recursively,
22580 since the standard is unclear (as detailed below). */
22582 void
22584 {
22594 {
22595 tree tmpl =
22599 else
22602 }
22607 {
22610 t);
22612 }
22615 {
22617 {
22619 {
22622 "ISO C++ 1998 forbids the use of %<extern%> on "
22624 }
22625 else
22627 "ISO C++ forbids the use of %qE"
22629 }
22637 else
22638 {
22640 storage);
22642 }
22643 }
22646 {
22647 /* DR 259 [temp.spec].
22649 Both an explicit instantiation and a declaration of an explicit
22650 specialization shall not appear in a program unless the explicit
22651 instantiation follows a declaration of the explicit specialization.
22653 For a given set of template parameters, if an explicit
22654 instantiation of a template appears after a declaration of an
22655 explicit specialization for that template, the explicit
22656 instantiation has no effect. */
22658 }
22660 {
22661 /* [temp.spec]
22663 No program shall explicitly instantiate any template more
22664 than once.
22666 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22667 instantiation was `extern'. If EXTERN_P then the second is.
22668 These cases are OK. */
22675 /* If we've already instantiated the template, just return now. */
22678 }
22686 /* In contrast to implicit instantiation, where only the
22687 declarations, and not the definitions, of members are
22688 instantiated, we have here:
22690 [temp.explicit]
22692 The explicit instantiation of a class template specialization
22693 implies the instantiation of all of its members not
22694 previously explicitly specialized in the translation unit
22695 containing the explicit instantiation.
22697 Of course, we can't instantiate member template classes, since we
22698 don't have any arguments for them. Note that the standard is
22699 unclear on whether the instantiation of the members are
22700 *explicit* instantiations or not. However, the most natural
22701 interpretation is that it should be an explicit
22702 instantiation. */
22706 && !static_p
22709 {
22714 }
22719 }
22721 /* Given a function DECL, which is a specialization of TMPL, modify
22722 DECL to be a re-instantiation of TMPL with the same template
22723 arguments. TMPL should be the template into which tsubst'ing
22724 should occur for DECL, not the most general template.
22726 One reason for doing this is a scenario like this:
22728 template <class T>
22729 void f(const T&, int i);
22731 void g() { f(3, 7); }
22733 template <class T>
22734 void f(const T& t, const int i) { }
22736 Note that when the template is first instantiated, with
22737 instantiate_template, the resulting DECL will have no name for the
22738 first parameter, and the wrong type for the second. So, when we go
22739 to instantiate the DECL, we regenerate it. */
22741 static void
22743 {
22744 /* The arguments used to instantiate DECL, from the most general
22745 template. */
22746 tree code_pattern;
22750 /* Make sure that we can see identifiers, and compute access
22751 correctly. */
22755 {
22756 tree decl_parm;
22757 tree pattern_parm;
22758 tree specs;
22772 specs);
22774 /* Merge parameter declarations. */
22777 pattern_parm
22781 {
22782 tree parm_type;
22783 tree attributes;
22788 NULL_TREE);
22794 {
22797 }
22800 }
22801 /* Merge any parameters that match with the function parameter
22802 pack. */
22804 {
22806 tree expanded_types;
22807 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22808 the parameters in this function parameter pack. */
22813 {
22814 tree parm_type;
22815 tree attributes;
22818 /* Rename the parameter to include the index. */
22827 {
22830 }
22832 }
22833 }
22834 /* Merge additional specifiers from the CODE_PATTERN. */
22838 }
22840 {
22850 }
22851 else
22855 }
22857 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22858 substituted to get DECL. */
22860 tree
22862 {
22865 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22866 for the instantiation. This is not always the most general
22867 template. Consider, for example:
22869 template <class T>
22870 struct S { template <class U> void f();
22871 template <> void f<int>(); };
22873 and an instantiation of S<double>::f<int>. We want TD to be the
22874 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22876 more general template. */
22878 /* We must also deal with friend templates. Given:
22880 template <class T> struct S {
22881 template <class U> friend void f() {};
22882 };
22884 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22885 so far as the language is concerned, but that's still
22886 where we get the pattern for the instantiation from. On
22887 other hand, if the definition comes outside the class, say:
22889 template <class T> struct S {
22890 template <class U> friend void f();
22891 };
22892 template <class U> friend void f() {}
22894 we don't need to look any further. That's what the check for
22895 DECL_INITIAL is for. */
22899 {
22900 /* The present template, TD, should not be a definition. If it
22901 were a definition, we should be using it! Note that we
22902 cannot restructure the loop to just keep going until we find
22903 a template with a definition, since that might go too far if
22904 a specialization was declared, but not defined. */
22906 /* Fetch the more general template. */
22908 }
22911 }
22913 /* Returns true if we need to instantiate this template instance even if we
22914 know we aren't going to emit it. */
22916 bool
22918 {
22919 /* We always instantiate inline functions so that we can inline them. An
22920 explicit instantiation declaration prohibits implicit instantiation of
22921 non-inline functions. With high levels of optimization, we would
22922 normally inline non-inline functions -- but we're not allowed to do
22923 that for "extern template" functions. Therefore, we check
22924 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22928 /* And we need to instantiate static data members so that
22929 their initializers are available in integral constant
22930 expressions. */
22933 }
22935 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22936 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22937 error, true otherwise. */
22939 bool
22941 {
22944 /* Don't instantiate a noexcept-specification from template context. */
22959 {
22965 {
22966 /* If hash_set::add returns true, the element was already there. */
22971 fn);
22973 }
22975 {
22990 }
22991 else
23001 }
23004 {
23007 else
23009 }
23012 }
23014 /* We're starting to process the function INST, an instantiation of PATTERN;
23015 add their parameters to local_specializations. */
23017 static void
23019 {
23023 {
23027 }
23029 {
23031 {
23034 }
23035 else
23036 {
23037 /* Register the (value) argument pack as a specialization of
23038 TMPL_PARM, then move on. */
23041 }
23042 }
23044 }
23046 /* Produce the definition of D, a _DECL generated from a template. If
23047 DEFER_OK is true, then we don't have to actually do the
23048 instantiation now; we just have to do it sometime. Normally it is
23049 an error if this is an explicit instantiation but D is undefined.
23050 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
23051 instantiated class template. */
23053 tree
23055 {
23057 tree gen_args;
23058 tree args;
23059 tree td;
23060 tree code_pattern;
23061 tree spec;
23062 tree gen_tmpl;
23070 /* This function should only be used to instantiate templates for
23071 functions and static member variables. */
23074 /* A concept is never instantiated. */
23077 /* Variables are never deferred; if instantiation is required, they
23078 are instantiated right away. That allows for better code in the
23079 case that an expression refers to the value of the variable --
23080 if the variable has a constant value the referring expression can
23081 take advantage of that fact. */
23085 /* Don't instantiate cloned functions. Instead, instantiate the
23086 functions they cloned. */
23094 /* D has already been instantiated or explicitly specialized, so
23095 there's nothing for us to do here.
23097 It might seem reasonable to check whether or not D is an explicit
23098 instantiation, and, if so, stop here. But when an explicit
23099 instantiation is deferred until the end of the compilation,
23100 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
23101 the instantiation. */
23104 /* Check to see whether we know that this template will be
23105 instantiated in some other file, as with "extern template"
23106 extension. */
23109 /* In general, we do not instantiate such templates. */
23117 /* We should already have the extra args. */
23120 /* And what's in the hash table should match D. */
23124 /* This needs to happen before any tsubsting. */
23130 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
23131 for the instantiation. */
23136 {
23137 /* Look up an explicit specialization, if any. */
23141 {
23144 }
23145 }
23149 /* We should never be trying to instantiate a member of a class
23150 template or partial specialization. */
23155 /* In the case of a friend template whose definition is provided
23156 outside the class, we may have too many arguments. Drop the
23157 ones we don't need. The same is true for specializations. */
23158 args = get_innermost_template_args
23162 {
23168 }
23169 else
23170 {
23175 else
23177 }
23179 /* We may be in the middle of deferred access check. Disable it now. */
23182 /* Unless an explicit instantiation directive has already determined
23183 the linkage of D, remember that a definition is available for
23184 this entity. */
23194 /* If D is a member of an explicitly instantiated class template,
23195 and no definition is available, treat it like an implicit
23196 instantiation. */
23199 {
23200 /* Leave linkage flags alone on instantiations with anonymous
23201 visibility. */
23203 {
23206 }
23208 }
23210 /* Defer all other templates, unless we have been explicitly
23211 forbidden from doing so. */
23213 template. */
23214 ! pattern_defined
23215 /* If it's OK to postpone instantiation, do so. */
23216 || defer_ok
23217 /* If this is a static data member that will be defined
23218 elsewhere, we don't want to instantiate the entire data
23219 member, but we do want to instantiate the initializer so that
23220 we can substitute that elsewhere. */
23222 /* Handle here a deleted function too, avoid generating
23223 its body (c++/61080). */
23225 {
23226 /* The definition of the static data member is now required so
23227 we must substitute the initializer. */
23231 {
23232 tree ns;
23233 tree init;
23242 args,
23245 /* If instantiating the initializer involved instantiating this
23246 again, don't call cp_finish_decl twice. */
23248 {
23249 /* Make sure the initializer is still constant, in case of
23250 circular dependency (template/instantiate6.C). */
23251 const_init
23255 LOOKUP_ONLYCONVERTING);
23256 }
23260 }
23262 /* We restore the source position here because it's used by
23263 add_pending_template. */
23269 /* [temp.explicit]
23271 The definition of a non-exported function template, a
23272 non-exported member function template, or a non-exported
23273 member function or static data member of a class template
23274 shall be present in every translation unit in which it is
23275 explicitly instantiated. */
23279 /* If we're in unevaluated context, we just wanted to get the
23280 constant value; this isn't an odr use, so don't queue
23281 a full instantiation. */
23284 /* ??? Historically, we have instantiated inline functions, even
23285 when marked as "extern template". */
23289 }
23290 /* Tell the repository that D is available in this translation unit
23291 -- and see if it is supposed to be instantiated here. */
23293 {
23294 /* In a PCH file, despite the fact that the repository hasn't
23295 requested instantiation in the PCH it is still possible that
23296 an instantiation will be required in a file that includes the
23297 PCH. */
23300 /* Instantiate inline functions so that the inliner can do its
23301 job, even though we'll not be emitting a copy of this
23302 function. */
23305 }
23308 tree fn_context;
23319 else
23320 {
23324 }
23326 /* Mark D as instantiated so that recursive calls to
23327 instantiate_decl do not try to instantiate it again. */
23330 /* Regenerate the declaration in case the template has been modified
23331 by a subsequent redeclaration. */
23334 /* We already set the file and line above. Reset them now in case
23335 they changed as a result of calling regenerate_decl_from_template. */
23339 {
23340 tree init;
23343 /* Clear out DECL_RTL; whatever was there before may not be right
23344 since we've reset the type of the declaration. */
23348 /* The initializer is placed in DECL_INITIAL by
23349 regenerate_decl_from_template so we don't need to
23350 push/pop_access_scope again here. Pull it out so that
23351 cp_finish_decl can process it. */
23356 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23357 initializer. That function will defer actual emission until
23358 we have a chance to determine linkage. */
23361 /* Enter the scope of D so that access-checking works correctly. */
23374 }
23378 {
23379 /* Set up the list of local specializations. */
23383 /* Set up context. */
23387 else
23390 /* Some typedefs referenced from within the template code need to be
23391 access checked at template instantiation time, i.e now. These
23392 types were added to the template at parsing time. Let's get those
23393 and perform the access checks then. */
23395 args);
23397 /* Create substitution entries for the parameters. */
23400 /* Substitute into the body of the function. */
23404 else
23405 {
23410 /* Set the current input_location to the end of the function
23411 so that finish_function knows where we are. */
23412 input_location
23415 /* Remember if we saw an infinite loop in the template. */
23416 current_function_infinite_loop
23418 }
23420 /* Finish the function. */
23424 else
23425 {
23428 }
23432 }
23434 /* We're not deferring instantiation any more. */
23439 else
23445 out:
23454 }
23456 /* Run through the list of templates that we wish we could
23457 instantiate, and instantiate any we can. RETRIES is the
23458 number of times we retry pending template instantiation. */
23460 void
23462 {
23466 /* Instantiating templates may trigger vtable generation. This in turn
23467 may require further template instantiations. We place a limit here
23468 to avoid infinite loop. */
23470 {
23474 "template instantiation depth exceeds maximum of %d"
23475 " instantiating %q+D, possibly from virtual table generation"
23479 /* Pretend that we defined it. */
23482 }
23484 do
23485 {
23490 {
23495 {
23497 {
23512 }
23515 }
23516 else
23517 {
23520 {
23521 instantiation
23527 }
23531 }
23534 /* If INSTANTIATION has been instantiated, then we don't
23535 need to consider it again in the future. */
23537 else
23538 {
23541 }
23544 }
23546 }
23550 }
23552 /* Substitute ARGVEC into T, which is a list of initializers for
23553 either base class or a non-static data member. The TREE_PURPOSEs
23554 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23555 instantiate_decl. */
23557 static tree
23559 {
23563 {
23564 tree decl;
23565 tree init;
23571 {
23572 tree expr;
23573 tree arg;
23575 /* Expand the base class expansion type into separate base
23576 classes. */
23578 tf_warning_or_error,
23579 NULL_TREE);
23583 /* We'll be building separate TREE_LISTs of arguments for
23584 each base. */
23590 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23591 expand each argument in the TREE_VALUE of t. */
23598 /* VOID_TYPE_NODE is used to indicate
23599 value-initialization. */
23600 {
23603 }
23604 else
23605 {
23606 /* Substitute parameter packs into each argument in the
23607 TREE_LIST. */
23610 {
23611 tree expanded_exprs;
23613 /* Expand the argument. */
23615 expanded_exprs
23617 tf_warning_or_error,
23618 NULL_TREE);
23622 /* Prepend each of the expanded expressions to the
23623 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23625 {
23630 }
23631 }
23634 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23635 since we built them backwards. */
23637 {
23640 }
23641 }
23642 }
23645 {
23647 {
23651 }
23652 else
23653 {
23654 tree tmp;
23669 /* If we had an initializer but it instantiated to nothing,
23670 value-initialize the object. This will only occur when
23671 the initializer was a pack expansion where the parameter
23672 packs used in that expansion were of length zero. */
23675 }
23678 {
23682 }
23683 }
23684 }
23686 }
23688 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23690 static void
23692 {
23697 else
23699 }
23701 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23702 is the instantiation (which should have been created with
23703 start_enum) and ARGS are the template arguments to use. */
23705 static void
23707 {
23708 tree e;
23714 {
23715 tree value;
23716 tree decl;
23719 /* Note that in a template enum, the TREE_VALUE is the
23720 CONST_DECL, not the corresponding INTEGER_CST. */
23725 /* Give this enumeration constant the correct access. */
23728 /* Actually build the enumerator itself. Here we're assuming that
23729 enumerators can't have dependent attributes. */
23732 }
23742 }
23744 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23745 its type -- but without substituting the innermost set of template
23746 arguments. So, innermost set of template parameters will appear in
23747 the type. */
23749 tree
23751 {
23752 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23754 }
23756 /* Return truthvalue if we're processing a template different from
23757 the last one involved in diagnostics. */
23758 bool
23760 {
23762 }
23764 /* Remember current template involved in diagnostics. */
23765 void
23767 {
23769 }
23773 {
23775 }
23777 /* Return TRUE if current_function_decl is being instantiated, false
23778 otherwise. */
23780 bool
23782 {
23785 }
23787 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23788 type. Return false for ok, true for disallowed. Issue error and
23789 inform messages under control of COMPLAIN. */
23791 static bool
23793 {
23808 /* A bound template template parm could later be instantiated to have a valid
23809 nontype parm type via an alias template. */
23815 {
23818 else
23820 type);
23821 }
23823 }
23825 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23826 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23828 static bool
23830 {
23831 tree scope;
23833 /* [temp.dep.type]
23835 A type is dependent if it is:
23837 -- a template parameter. Template template parameters are types
23838 for us (since TYPE_P holds true for them) so we handle
23839 them here. */
23843 /* -- a qualified-id with a nested-name-specifier which contains a
23844 class-name that names a dependent type or whose unqualified-id
23845 names a dependent type. */
23849 /* An alias template specialization can be dependent even if the
23850 resulting type is not. */
23854 /* -- a cv-qualified type where the cv-unqualified type is
23855 dependent.
23856 No code is necessary for this bullet; the code below handles
23857 cv-qualified types, and we don't want to strip aliases with
23858 TYPE_MAIN_VARIANT because of DR 1558. */
23859 /* -- a compound type constructed from any dependent type. */
23869 {
23870 tree arg_type;
23875 arg_type;
23880 /* A value-dependent noexcept-specifier makes the type dependent. */
23883 /* Treat DEFERRED_NOEXCEPT as non-dependent, since it doesn't
23884 affect overload resolution and treating it as dependent breaks
23885 things. */
23890 }
23891 /* -- an array type constructed from any dependent type or whose
23892 size is specified by a constant expression that is
23893 value-dependent.
23895 We checked for type- and value-dependence of the bounds in
23896 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23898 {
23903 }
23905 /* -- a template-id in which either the template name is a template
23906 parameter ... */
23909 /* ... or any of the template arguments is a dependent type or
23910 an expression that is type-dependent or value-dependent. */
23912 && (any_dependent_template_arguments_p
23916 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23917 dependent; if the argument of the `typeof' expression is not
23918 type-dependent, then it should already been have resolved. */
23924 /* A template argument pack is dependent if any of its packed
23925 arguments are. */
23927 {
23933 }
23935 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23936 be template parameters. */
23943 /* The standard does not specifically mention types that are local
23944 to template functions or local classes, but they should be
23945 considered dependent too. For example:
23947 template <int I> void f() {
23948 enum E { a = I };
23949 S<sizeof (E)> s;
23950 }
23952 The size of `E' cannot be known until the value of `I' has been
23953 determined. Therefore, `E' must be considered dependent. */
23957 /* Don't use type_dependent_expression_p here, as it can lead
23958 to infinite recursion trying to determine whether a lambda
23959 nested in a lambda is dependent (c++/47687). */
23963 && (any_dependent_template_arguments_p
23967 /* Other types are non-dependent. */
23969 }
23971 /* Returns TRUE if TYPE is dependent, in the sense of
23972 [temp.dep.type]. Note that a NULL type is considered dependent. */
23974 bool
23976 {
23977 /* If there are no template parameters in scope, then there can't be
23978 any dependent types. */
23980 {
23981 /* If we are not processing a template, then nobody should be
23982 providing us with a dependent type. */
23986 }
23988 /* If the type is NULL, we have not computed a type for the entity
23989 in question; in that case, the type is dependent. */
23993 /* Erroneous types can be considered non-dependent. */
23997 /* Getting here with global_type_node means we improperly called this
23998 function on the TREE_TYPE of an IDENTIFIER_NODE. */
24001 /* If we have not already computed the appropriate value for TYPE,
24002 do so now. */
24004 {
24007 }
24010 }
24012 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
24013 lookup. In other words, a dependent type that is not the current
24014 instantiation. */
24016 bool
24018 {
24021 }
24023 /* T is a SCOPE_REF. Return whether it represents a non-static member of
24024 an unknown base of 'this' (and is therefore instantiation-dependent). */
24026 static bool
24028 {
24045 }
24047 /* T is a SCOPE_REF; return whether we need to consider it
24048 instantiation-dependent so that we can check access at instantiation
24049 time even though we know which member it resolves to. */
24051 static bool
24053 {
24060 else
24062 }
24064 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
24065 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
24066 expression. */
24068 /* Note that this predicate is not appropriate for general expressions;
24069 only constant expressions (that satisfy potential_constant_expression)
24070 can be tested for value dependence. */
24072 bool
24074 {
24078 /* A type-dependent expression is also value-dependent. */
24083 {
24085 /* A dependent member function of the current instantiation. */
24089 /* A dependent member function of the current instantiation. */
24096 /* A name that has not been looked up -- must be dependent. */
24100 /* A non-type template parm. */
24104 /* A non-type template parm. */
24110 /* A constant with literal type and is initialized
24111 with an expression that is value-dependent. */
24113 /* FIXME cp_finish_decl doesn't fold reference initializers. */
24117 {
24121 }
24130 /* These expressions are value-dependent if the type to which
24131 the cast occurs is dependent or the expression being casted
24132 is value-dependent. */
24133 {
24139 /* A functional cast has a list of operands. */
24142 {
24143 /* If there are no operands, it must be an expression such
24144 as "int()". This should not happen for aggregate types
24145 because it would form non-constant expressions. */
24150 }
24156 }
24161 /* FALLTHRU */
24164 /* A `sizeof' expression is value-dependent if the operand is
24165 type-dependent or is a pack expansion. */
24174 /* An 'encode' expression is value-dependent if the operand is
24175 type-dependent. */
24184 /* All instantiation-dependent expressions should also be considered
24185 value-dependent. */
24193 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
24194 is value-dependent. */
24195 {
24204 }
24207 {
24224 }
24235 {
24239 }
24242 /* Treat all requires-expressions as value-dependent so
24243 we don't try to fold them. */
24250 {
24257 {
24259 /* In a call to a constexpr member function, look through the
24260 implicit ADDR_EXPR on the object argument so that it doesn't
24261 cause the call to be considered value-dependent. We also
24262 look through it in potential_constant_expression. */
24269 }
24271 }
24277 {
24279 tree val;
24286 }
24289 /* Treat a GNU statement expression as dependent to avoid crashing
24290 under instantiate_non_dependent_expr; it can't be constant. */
24294 /* A constant expression is value-dependent if any subexpression is
24295 value-dependent. */
24297 {
24304 {
24308 {
24311 /* In some cases, some of the operands may be missing.
24312 (For example, in the case of PREDECREMENT_EXPR, the
24313 amount to increment by may be missing.) That doesn't
24314 make the expression dependent. */
24317 }
24318 }
24322 }
24324 }
24326 /* The expression is not value-dependent. */
24328 }
24330 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24331 [temp.dep.expr]. Note that an expression with no type is
24332 considered dependent. Other parts of the compiler arrange for an
24333 expression with type-dependent subexpressions to have no type, so
24334 this function doesn't have to be fully recursive. */
24336 bool
24338 {
24347 /* An unresolved name is always dependent. */
24353 /* A fold expression is type-dependent. */
24360 /* Some expression forms are never type-dependent. */
24374 /* The types of these expressions depends only on the type to which
24375 the cast occurs. */
24384 /* The types of these expressions depends only on the type created
24385 by the expression. */
24388 {
24389 /* For NEW_EXPR tree nodes created inside a template, either
24390 the object type itself or a TREE_LIST may appear as the
24391 operand 1. */
24394 /* This is an array type. We need to check array dimensions
24395 as well. */
24397 || value_dependent_expression_p
24399 else
24401 }
24404 {
24408 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24409 contains an identifier associated by name lookup with one or more
24410 declarations declared with a dependent type, or...a
24411 nested-name-specifier or qualified-id that names a member of an
24412 unknown specialization. */
24415 }
24425 {
24426 tree elt;
24430 {
24433 }
24435 }
24437 /* A static data member of the current instantiation with incomplete
24438 array type is type-dependent, as the definition and specializations
24439 can have different bounds. */
24446 /* An array of unknown bound depending on a variadic parameter, eg:
24448 template<typename... Args>
24449 void foo (Args... args)
24450 {
24451 int arr[] = { args... };
24452 }
24454 template<int... vals>
24455 void bar ()
24456 {
24457 int arr[] = { vals... };
24458 }
24460 If the array has no length and has an initializer, it must be that
24461 we couldn't determine its length in cp_complete_array_type because
24462 it is dependent. */
24470 /* A function or variable template-id is type-dependent if it has any
24471 dependent template arguments. */
24475 {
24476 /* Consider the innermost template arguments, since those are the ones
24477 that come from the template-id; the template arguments for the
24478 enclosing class do not make it type-dependent unless they are used in
24479 the type of the decl. */
24481 && (any_dependent_template_arguments_p
24484 }
24486 /* Otherwise, if the function decl isn't from a dependent scope, it can't be
24487 type-dependent. Checking this is important for functions with auto return
24488 type, which looks like a dependent type. */
24496 {
24500 }
24502 /* Always dependent, on the number of arguments if nothing else. */
24507 {
24512 {
24518 }
24519 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24524 {
24529 }
24532 {
24539 }
24549 }
24553 /* Dependent type attributes might not have made it from the decl to
24554 the type yet. */
24560 }
24562 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24563 type-dependent if the expression refers to a member of the current
24564 instantiation and the type of the referenced member is dependent, or the
24565 class member access expression refers to a member of an unknown
24566 specialization.
24568 This function returns true if the OBJECT in such a class member access
24569 expression is of an unknown specialization. */
24571 bool
24573 {
24574 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24575 dependent. */
24580 }
24582 /* walk_tree callback function for instantiation_dependent_expression_p,
24583 below. Returns non-zero if a dependent subexpression is found. */
24585 static tree
24588 {
24590 {
24591 /* We don't have to worry about decltype currently because decltype
24592 of an instantiation-dependent expr is a dependent type. This
24593 might change depending on the resolution of DR 1172. */
24596 }
24599 {
24600 /* Don't treat an argument list as dependent just because it has no
24601 TREE_TYPE. */
24609 /* Handle expressions with type operands. */
24614 {
24619 {
24622 else
24623 {
24626 }
24627 }
24629 }
24633 /* In a template, finish_class_member_access_expr creates a
24634 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24635 type-dependent, so that we can check access control at
24636 instantiation time (PR 42277). See also Core issue 1273. */
24643 else
24646 /* Treat statement-expressions as dependent. */
24650 /* Treat requires-expressions as dependent. */
24655 /* Treat calls to function concepts as dependent. */
24661 /* And variable concepts. */
24668 }
24672 else
24674 }
24676 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24677 sense defined by the ABI:
24679 "An expression is instantiation-dependent if it is type-dependent
24680 or value-dependent, or it has a subexpression that is type-dependent
24681 or value-dependent."
24683 Except don't actually check value-dependence for unevaluated expressions,
24684 because in sizeof(i) we don't care about the value of i. Checking
24685 type-dependence will in turn check value-dependence of array bounds/template
24686 arguments as needed. */
24688 bool
24690 {
24691 tree result;
24702 }
24704 /* As above, but also check value-dependence of the expression as a whole. */
24706 bool
24708 {
24711 }
24713 /* Like type_dependent_expression_p, but it also works while not processing
24714 a template definition, i.e. during substitution or mangling. */
24716 bool
24718 {
24724 }
24726 /* Returns TRUE if ARGS contains a type-dependent expression. */
24728 bool
24730 {
24732 tree arg;
24735 {
24738 }
24740 }
24742 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24743 expressions) contains any type-dependent expressions. */
24745 bool
24747 {
24753 }
24755 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24756 expressions) contains any value-dependent expressions. */
24758 bool
24760 {
24766 }
24768 /* Returns TRUE if the ARG (a template argument) is dependent. */
24770 bool
24772 {
24776 /* Assume a template argument that was wrongly written by the user
24777 is dependent. This is consistent with what
24778 any_dependent_template_arguments_p [that calls this function]
24779 does. */
24789 {
24792 /* A member template of a dependent class is not necessarily
24793 type-dependent, but it is a dependent template argument because it
24794 will be a member of an unknown specialization to that template. */
24797 }
24799 {
24803 {
24806 }
24809 }
24812 else
24815 }
24817 /* Returns true if ARGS (a collection of template arguments) contains
24818 any types that require structural equality testing. */
24820 bool
24822 {
24832 {
24835 {
24841 {
24842 /* Look inside the argument pack. */
24845 }
24848 {
24861 }
24862 }
24863 }
24866 }
24868 /* Returns true if ARGS (a collection of template arguments) contains
24869 any dependent arguments. */
24871 bool
24873 {
24883 {
24888 }
24891 }
24893 /* Returns TRUE if the template TMPL is type-dependent. */
24895 bool
24897 {
24899 {
24904 }
24906 /* Template template parameters are dependent. */
24910 /* So are names that have not been looked up. */
24914 }
24916 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24918 bool
24920 {
24923 }
24925 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24926 are dependent. */
24928 bool
24930 {
24937 {
24959 {
24963 }
24967 {
24971 {
24976 }
24977 }
24978 }
24981 }
24983 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24984 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24985 no such TYPE can be found. Note that this function peers inside
24986 uninstantiated templates and therefore should be used only in
24987 extremely limited situations. ONLY_CURRENT_P restricts this
24988 peering to the currently open classes hierarchy (which is required
24989 when comparing types). */
24991 tree
24993 {
24994 tree scope;
24995 tree name;
24996 tree decl;
24998 tree pushed_scope;
24999 tree result;
25004 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
25005 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
25006 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
25007 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
25008 identifier of the TYPENAME_TYPE anymore.
25009 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
25010 TYPENAME_TYPE instead, we avoid messing up with a possible
25011 typedef variant case. */
25014 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
25015 it first before we can figure out what NAME refers to. */
25017 {
25019 /* Given a class template A with a dependent base with nested type C,
25020 typedef typename A::C::C C will land us here, as trying to resolve
25021 the initial A::C leads to the local C typedef, which leads back to
25022 A::C::C. So we break the recursion now. */
25024 else
25026 }
25027 /* If we don't know what SCOPE refers to, then we cannot resolve the
25028 TYPENAME_TYPE. */
25031 /* If this is a typedef, we don't want to look inside (c++/11987). */
25034 /* If SCOPE isn't the template itself, it will not have a valid
25035 TYPE_FIELDS list. */
25037 /* scope is either the template itself or a compatible instantiation
25038 like X<T>, so look up the name in the original template. */
25040 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
25042 /* If scope has no fields, it can't be a current instantiation. Check this
25043 before currently_open_class to avoid infinite recursion (71515). */
25046 /* If the SCOPE is not the current instantiation, there's no reason
25047 to look inside it. */
25050 /* Enter the SCOPE so that name lookup will be resolved as if we
25051 were in the class definition. In particular, SCOPE will no
25052 longer be considered a dependent type. */
25054 /* Look up the declaration. */
25056 tf_warning_or_error);
25060 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
25061 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
25067 {
25071 }
25074 {
25075 /* Obtain the template and the arguments. */
25078 {
25079 /* We get here with a plain identifier because a previous tentative
25080 parse of the nested-name-specifier as part of a ptr-operator saw
25081 ::template X<A>. The use of ::template is necessary in a
25082 ptr-operator, but wrong in a declarator-id.
25084 [temp.names]: In a qualified-id of a declarator-id, the keyword
25085 template shall not appear at the top level. */
25089 }
25091 /* Instantiate the template. */
25097 }
25099 /* Leave the SCOPE. */
25103 /* If we failed to resolve it, return the original typename. */
25107 /* If lookup found a typename type, resolve that too. */
25109 {
25110 /* Ill-formed programs can cause infinite recursion here, so we
25111 must catch that. */
25115 }
25117 /* Qualify the resulting type. */
25123 }
25125 /* EXPR is an expression which is not type-dependent. Return a proxy
25126 for EXPR that can be used to compute the types of larger
25127 expressions containing EXPR. */
25129 tree
25131 {
25133 tree inner_expr;
25135 /* When checking, try to get a constant value for all non-dependent
25136 expressions in order to expose bugs in *_dependent_expression_p
25137 and constexpr. This can affect code generation, see PR70704, so
25138 only do this for -fchecking=2. */
25141 /* Don't do this during nsdmi parsing as it can lead to
25142 unexpected recursive instantiations. */
25144 /* Don't do this during concept expansion either and for
25145 the same reason. */
25151 /* Preserve OVERLOADs; the functions must be available to resolve
25152 types. */
25163 /* There is no need to return a proxy for a variable. */
25166 /* Preserve string constants; conversions from string constants to
25167 "char *" are allowed, even though normally a "const char *"
25168 cannot be used to initialize a "char *". */
25171 /* Preserve void and arithmetic constants, as an optimization -- there is no
25172 reason to create a new node. */
25177 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
25178 There is at least one place where we want to know that a
25179 particular expression is a throw-expression: when checking a ?:
25180 expression, there are special rules if the second or third
25181 argument is a throw-expression. */
25185 /* Don't wrap an initializer list, we need to be able to look inside. */
25189 /* Don't wrap a dummy object, we need to be able to test for it. */
25208 /* If the type is unknown, it can't really be non-dependent */
25211 /* Otherwise, build a NON_DEPENDENT_EXPR. */
25213 }
25215 /* ARGS is a vector of expressions as arguments to a function call.
25216 Replace the arguments with equivalent non-dependent expressions.
25217 This modifies ARGS in place. */
25219 void
25221 {
25223 tree arg;
25226 {
25230 }
25231 }
25233 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
25234 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
25235 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
25237 static tree
25239 {
25253 }
25255 tree
25257 {
25259 }
25261 tree
25263 {
25265 }
25267 /* Return a C++17 deduction placeholder for class template TMPL. */
25269 tree
25271 {
25275 }
25277 /* True iff T is a C++17 class template deduction placeholder. */
25279 bool
25281 {
25283 }
25285 /* Make a "constrained auto" type-specifier. This is an
25286 auto type with constraints that must be associated after
25287 deduction. The constraint is formed from the given
25288 CONC and its optional sequence of arguments, which are
25289 non-null if written as partial-concept-id. */
25291 tree
25293 {
25296 /* Build the constraint. */
25304 /* Our canonical type depends on the constraint. */
25307 /* Attach the constraint to the type declaration. */
25310 }
25312 /* Given type ARG, return std::initializer_list<ARG>. */
25314 static tree
25316 {
25320 {
25324 "deducing from brace-enclosed initializer list"
25328 }
25334 }
25336 /* Replace auto in TYPE with std::initializer_list<auto>. */
25338 static tree
25340 {
25347 }
25349 /* Hash traits for hashing possibly constrained 'auto'
25350 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25353 {
25356 };
25358 /* Hash the 'auto' T. */
25360 inline hashval_t
25362 {
25364 /* Matching constrained-type-specifiers denote the same template
25365 parameter, so hash the constraint. */
25367 else
25368 /* But unconstrained autos are all separate, so just hash the pointer. */
25370 }
25372 /* Compare two 'auto's. */
25376 {
25383 /* Two unconstrained autos are distinct. */
25388 }
25390 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25391 constrained) auto, add it to the vector. */
25393 static int
25395 {
25398 {
25399 /* All the autos were built with index 0; fix that up now. */
25403 /* If this is a repeated constrained-type-specifier, use the index we
25404 chose before. */
25406 else
25407 {
25408 /* Otherwise this is new, so use the current count. */
25411 }
25413 }
25415 /* Always keep walking. */
25417 }
25419 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25420 says they can appear anywhere in the type. */
25422 static tree
25424 {
25433 {
25438 }
25441 }
25443 /* The stem for deduction guide names. */
25446 /* Return the name for a deduction guide for class template TMPL. */
25448 tree
25450 {
25461 }
25463 /* True if NAME is the name of a deduction guide. */
25465 bool
25467 {
25472 }
25474 /* True if FN is a deduction guide. */
25476 bool
25478 {
25483 }
25485 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25487 bool
25489 {
25496 }
25498 /* True if FN is a guide generated from a constructor template. */
25500 bool
25502 {
25510 }
25512 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25513 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25514 template parameter types. Note that the handling of template template
25515 parameters relies on current_template_parms being set appropriately for the
25516 new template. */
25518 static tree
25521 {
25524 tree newtype;
25527 {
25534 }
25535 else
25539 tree newdecl
25544 tree newidx;
25547 {
25557 {
25562 // First create a copy (ttargs) of tsubst_args with an
25563 // additional level for the template template parameter's own
25564 // template parameters (ttparms).
25565 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25573 // Substitute ttargs into ttparms to fix references to
25574 // other template parameters.
25576 complain);
25577 // Now substitute again with args based on tparms, to reduce
25578 // the level of the ttparms.
25581 complain);
25582 // Finally, tack the adjusted parms onto tparms.
25584 current_template_parms);
25586 }
25587 }
25588 else
25589 {
25591 tree newconst
25603 }
25606 }
25608 /* Returns a C++17 class deduction guide template based on the constructor
25609 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25610 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25612 static tree
25614 {
25618 location_t loc;
25622 {
25626 {
25629 }
25630 else
25640 }
25641 else
25642 {
25645 fn_tmpl
25655 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25656 fully specialized args for the enclosing class. Strip those off, as
25657 the deduction guide won't have those template parameters. */
25660 /* Discard the 'this' parameter. */
25668 {
25671 /* For a member template constructor, we need to flatten the two
25672 template parameter lists into one, and then adjust the function
25673 signature accordingly. This gets...complicated. */
25676 /* For a member template we should have two levels of parms/args, one
25677 for the class and one for the constructor. We stripped
25678 specialized args for further enclosing classes above. */
25682 /* Template args for translating references to the two-level template
25683 parameters into references to the one-level template parameters we
25684 are creating. */
25689 /* Template parms for the constructor template. */
25692 /* Template parms for the class template. */
25696 /* Template parms for the deduction guide start as a copy of the
25697 template parms for the class. We set current_template_parms for
25698 lookup_template_class_1. */
25704 /* Now we need to rewrite the constructor parms to append them to the
25705 class parms. */
25707 {
25722 }
25724 /* Now we have a final set of template parms to substitute into the
25725 function signature. */
25734 }
25736 }
25739 {
25740 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25744 }
25748 FUNCTION_DECL,
25765 }
25767 /* Deduce template arguments for the class template placeholder PTYPE for
25768 template TMPL based on the initializer INIT, and return the resulting
25769 type. */
25771 static tree
25773 tsubst_flags_t complain)
25774 {
25776 {
25777 /* We should have handled this in the caller. */
25783 }
25794 {
25797 {
25798 /* As an exception, the first phase in 16.3.1.7 (considering the
25799 initializer list as a single argument) is omitted if the
25800 initializer list consists of a single expression of type cv U,
25801 where U is a specialization of C or a class derived from a
25802 specialization of C. */
25813 }
25816 else
25818 }
25819 else
25830 /* Prune explicit deduction guides in copy-initialization context. */
25832 {
25838 {
25839 /* Found a nonconverting guide, prune the candidates. */
25846 }
25847 }
25852 {
25855 }
25858 // FIXME cache artificial deduction guides
25860 {
25865 else
25869 }
25873 /* If this is list-initialization and the class has a list constructor, first
25874 try deducing from the list as a single argument, as [over.match.list]. */
25878 {
25882 }
25884 {
25890 {
25891 /* That didn't work, now try treating the list as a sequence of
25892 arguments. */
25895 }
25896 }
25898 /* Maybe generate an implicit deduction guide. */
25900 {
25904 /* Generate a copy guide. */
25907 /* Generate a default guide. */
25911 {
25914 }
25915 }
25918 {
25920 " of %qT, as it has no non-explicit deduction guides or "
25923 }
25925 {
25929 }
25932 {
25936 }
25939 {
25949 }
25954 }
25956 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25957 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25958 The CONTEXT determines the context in which auto deduction is performed
25959 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25960 OUTER_TARGS are used during template argument deduction
25961 (context == adc_unify) to properly substitute the result, and is ignored
25962 in other contexts.
25964 For partial-concept-ids, extra args may be appended to the list of deduced
25965 template arguments prior to determining constraint satisfaction. */
25967 tree
25971 {
25972 tree targs;
25979 /* Defining a subset of type-dependent expressions that we can deduce
25980 from ahead of time isn't worth the trouble. */
25983 /* Similarly, we can't deduce from another undeduced decl. */
25988 /* C++17 class template argument deduction. */
25992 /* Nothing we can do with this, even in deduction context. */
25995 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25996 with either a new invented type template parameter U or, if the
25997 initializer is a braced-init-list (8.5.4), with
25998 std::initializer_list<U>. */
26000 {
26005 else
26006 {
26008 {
26012 "for deduction to %<std::initializer_list%>, use copy-"
26014 }
26016 }
26017 }
26028 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
26029 and initializer has array type, deduce cv-qualified array type. */
26031 complain);
26033 {
26042 {
26046 }
26047 }
26048 else
26049 {
26051 tree tparms;
26055 else
26056 {
26060 }
26067 {
26069 /* Try again at instantiation time. */
26073 /* If type is error_mark_node a diagnostic must have been
26074 emitted by now. Also, having a mention to '<type error>'
26075 in the diagnostic is not really useful to the user. */
26076 {
26080 else
26085 }
26087 }
26088 }
26090 /* Check any placeholder constraints against the deduced type. */
26093 {
26094 /* Use the deduced type to check the associated constraints. If we
26095 have a partial-concept-id, rebuild the argument list so that
26096 we check using the extra arguments. */
26100 {
26103 }
26104 else
26107 {
26109 {
26111 {
26129 }
26131 }
26133 }
26134 }
26140 }
26142 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
26143 result. */
26145 tree
26147 {
26149 {
26155 /* In an abbreviated function template we didn't know we were dealing
26156 with a function template when we saw the auto return type, so update
26157 it to have the correct level. */
26159 }
26161 }
26163 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
26164 'decltype(auto)' or a deduced class template. */
26166 bool
26168 {
26174 else
26176 }
26178 /* for_each_template_parm callback for type_uses_auto. */
26180 int
26182 {
26184 }
26186 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
26187 a use of `auto'. Returns NULL_TREE otherwise. */
26189 tree
26191 {
26195 {
26196 /* The Concepts TS allows multiple autos in one type-specifier; just
26197 return the first one we find, do_auto_deduction will collect all of
26198 them. */
26202 else
26204 }
26205 else
26207 }
26209 /* For a given template T, return the vector of typedefs referenced
26210 in T for which access check is needed at T instantiation time.
26211 T is either a FUNCTION_DECL or a RECORD_TYPE.
26212 Those typedefs were added to T by the function
26213 append_type_to_template_for_access_check. */
26217 {
26218 tree ti;
26229 {
26234 }
26237 }
26239 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26240 tied to T. That list of typedefs will be access checked at
26241 T instantiation time.
26242 T is either a FUNCTION_DECL or a RECORD_TYPE.
26243 TYPE_DECL is a TYPE_DECL node representing a typedef.
26244 SCOPE is the scope through which TYPE_DECL is accessed.
26245 LOCATION is the location of the usage point of TYPE_DECL.
26247 This function is a subroutine of
26248 append_type_to_template_for_access_check. */
26250 static void
26252 tree type_decl,
26253 tree scope,
26254 location_t location)
26255 {
26256 qualified_typedef_usage_t typedef_usage;
26257 tree ti;
26264 && type_decl
26278 }
26280 /* Append TYPE_DECL to the template TEMPL.
26281 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26282 At TEMPL instanciation time, TYPE_DECL will be checked to see
26283 if it can be accessed through SCOPE.
26284 LOCATION is the location of the usage point of TYPE_DECL.
26286 e.g. consider the following code snippet:
26288 class C
26289 {
26290 typedef int myint;
26291 };
26293 template<class U> struct S
26294 {
26295 C::myint mi; // <-- usage point of the typedef C::myint
26296 };
26298 S<char> s;
26300 At S<char> instantiation time, we need to check the access of C::myint
26301 In other words, we need to check the access of the myint typedef through
26302 the C scope. For that purpose, this function will add the myint typedef
26303 and the scope C through which its being accessed to a list of typedefs
26304 tied to the template S. That list will be walked at template instantiation
26305 time and access check performed on each typedefs it contains.
26306 Note that this particular code snippet should yield an error because
26307 myint is private to C. */
26309 void
26311 tree type_decl,
26312 tree scope,
26313 location_t location)
26314 {
26320 /* Make sure we don't append the type to the template twice. */
26327 }
26329 /* Convert the generic type parameters in PARM that match the types given in the
26330 range [START_IDX, END_IDX) from the current_template_parms into generic type
26331 packs. */
26333 tree
26335 {
26346 {
26347 /* Create a distinct parameter pack type from the current parm and add it
26348 to the replacement args to tsubst below into the generic function
26349 parameter. */
26364 }
26370 /* If there are more levels then build up the replacement with the outer
26371 template parms. */
26375 replacement);
26378 }
26380 /* Entries in the decl_constraint hash table. */
26382 {
26383 tree decl;
26384 tree ci;
26385 };
26387 /* Hashing function and equality for constraint entries. */
26389 {
26391 {
26393 }
26396 {
26398 }
26399 };
26401 /* A mapping from declarations to constraint information. Note that
26402 both templates and their underlying declarations are mapped to the
26403 same constraint information.
26405 FIXME: This is defined in pt.c because garbage collection
26406 code is not being generated for constraint.cc. */
26410 /* Returns the template constraints of declaration T. If T is not
26411 constrained, return NULL_TREE. Note that T must be non-null. */
26413 tree
26415 {
26426 else
26428 }
26430 /* Associate the given constraint information CI with the declaration
26431 T. If T is a template, then the constraints are associated with
26432 its underlying declaration. Don't build associations if CI is
26433 NULL_TREE. */
26435 void
26437 {
26449 }
26451 /* Remove the associated constraints of the declaration T. */
26453 void
26455 {
26464 }
26466 /* Memoized satisfaction results for declarations. This
26467 maps the pair (constraint_info, arguments) to the result computed
26468 by constraints_satisfied_p. */
26471 {
26472 tree ci;
26473 tree args;
26474 tree result;
26475 };
26477 /* Hashing function and equality for constraint entries. */
26480 {
26482 {
26485 }
26488 {
26490 }
26491 };
26493 /* Memoized satisfaction results for concept checks. */
26496 {
26497 tree tmpl;
26498 tree args;
26499 tree result;
26500 };
26502 /* Hashing function and equality for constraint entries. */
26505 {
26507 {
26509 }
26512 {
26517 }
26518 };
26523 /* Search for a memoized satisfaction result. Returns one of the
26524 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26526 tree
26528 {
26533 else
26535 }
26537 /* Memoize the result of a satisfication test. Returns the saved result. */
26539 tree
26541 {
26548 }
26550 /* Search for a memoized satisfaction result for a concept. */
26552 tree
26554 {
26559 else
26561 }
26563 /* Memoize the result of a concept check. Returns the saved result. */
26565 tree
26567 {
26574 }
26578 /* Returns a prior concept specialization. This returns the substituted
26579 and normalized constraints defined by the concept. */
26581 tree
26583 {
26588 else
26590 }
26592 /* Save a concept expansion for later. */
26594 tree
26596 {
26603 }
26605 static hashval_t
26607 {
26616 }
26618 /* Compare the constraints of two subsumption entries. The LEFT1 and
26619 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26620 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26622 static bool
26624 {
26632 }
26634 /* Key/value pair for learning and memoizing subsumption results. This
26635 associates a pair of check constraints (including arguments) with
26636 a boolean value indicating the result. */
26639 {
26640 tree t1;
26641 tree t2;
26643 };
26645 /* Hashing function and equality for constraint entries. */
26648 {
26650 {
26652 }
26655 {
26660 }
26661 };
26665 /* Search for a previously cached subsumption result. */
26669 {
26674 else
26676 }
26678 /* Save a subsumption result. */
26680 bool
26682 {
26689 }
26691 /* Set up the hash table for constraint association. */
26693 void
26695 {
26704 }
26706 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26707 0..N-1. */
26709 void
26711 {
26714 integer_type_node,
26715 NULL_TREE),
26719 }
26721 /* Set up the hash tables for template instantiations. */
26723 void
26725 {
26731 }
26733 /* Print stats about the template hash tables for -fstats. */
26735 void
26737 {
26746 }
26748 #if CHECKING_P
26752 /* Verify that build_non_dependent_expr () works, for various expressions,
26753 and that location wrappers don't affect the results. */
26755 static void
26757 {
26760 /* Verify constants, without and with location wrappers. */
26777 }
26779 /* Verify that type_dependent_expression_p () works correctly, even
26780 in the presence of location wrapper nodes. */
26782 static void
26784 {
26789 /* If no templates are involved, nothing is type-dependent. */
26795 /* Within a template, an unresolved name is always type-dependent. */
26798 /* Ensure it copes with NULL_TREE and errors. */
26802 /* A USING_DECL in a template should be type-dependent, even if wrapped
26803 with a location wrapper (PR c++/83799). */
26812 }
26814 /* Run all of the selftests within this file. */
26816 void
26818 {
26821 }