| blob | 710333ddabaca795be672775719bf0889f221f78 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
45 /* The type of functions taking a tree, and some additional data, and
46 returning an int. */
49 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
50 instantiations have been deferred, either because their definitions
51 were not yet available, or because we were putting off doing the work. */
55 };
70 /* Live only within one (recursive) call to tsubst_expr. We use
71 this to pass the statement expression node from the STMT_EXPR
72 to the EXPR_STMT that is its result. */
75 // -------------------------------------------------------------------------- //
76 // Local Specialization Stack
77 //
78 // Implementation of the RAII helper for creating new local
79 // specializations.
82 {
85 else
87 }
90 {
93 }
95 /* True if we've recursed into fn_type_unification too many times. */
99 {
100 tree tmpl;
101 tree args;
102 tree spec;
103 };
106 {
109 };
115 /* Contains canonical template parameter types. The vector is indexed by
116 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
117 TREE_LIST, whose TREE_VALUEs contain the canonical template
118 parameters of various types and levels. */
121 #define UNIFY_ALLOW_NONE 0
122 #define UNIFY_ALLOW_MORE_CV_QUAL 1
123 #define UNIFY_ALLOW_LESS_CV_QUAL 2
124 #define UNIFY_ALLOW_DERIVED 4
125 #define UNIFY_ALLOW_INTEGER 8
126 #define UNIFY_ALLOW_OUTER_LEVEL 16
127 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
128 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
131 tbr_incomplete_type,
132 tbr_ambiguous_baseclass,
133 tbr_success
134 };
157 tree);
214 location_t);
225 /* Make the current scope suitable for access checking when we are
226 processing T. T can be FUNCTION_DECL for instantiated function
227 template, VAR_DECL for static member variable, or TYPE_DECL for
228 alias template (needed by instantiate_decl). */
230 static void
232 {
240 else
244 {
245 saved_access_scope = tree_cons
248 }
249 }
251 /* Restore the scope set up by push_access_scope. T is the node we
252 are processing. */
254 static void
256 {
258 {
261 }
265 else
267 }
269 /* Do any processing required when DECL (a member template
270 declaration) is finished. Returns the TEMPLATE_DECL corresponding
271 to DECL, unless it is a specialization, in which case the DECL
272 itself is returned. */
274 tree
276 {
283 {
284 tree type;
292 {
296 }
298 }
302 {
304 {
307 }
308 else
310 }
311 else
315 }
317 /* Create a template info node. */
319 tree
321 {
326 }
328 /* Return the template info node corresponding to T, whatever T is. */
330 tree
332 {
354 }
356 /* Returns the template nesting level of the indicated class TYPE.
358 For example, in:
359 template <class T>
360 struct A
361 {
362 template <class U>
363 struct B {};
364 };
366 A<T>::B<U> has depth two, while A<T> has depth one.
367 Both A<T>::B<int> and A<int>::B<U> have depth one, if
368 they are instantiations, not specializations.
370 This function is guaranteed to return 0 if passed NULL_TREE so
371 that, for example, `template_class_depth (current_class_type)' is
372 always safe. */
374 int
376 {
380 {
391 else
393 }
396 }
398 /* Subroutine of maybe_begin_member_template_processing.
399 Returns true if processing DECL needs us to push template parms. */
401 static bool
403 {
409 }
411 /* Subroutine of maybe_begin_member_template_processing.
412 Push the template parms in PARMS, starting from LEVELS steps into the
413 chain, and ending at the beginning, since template parms are listed
414 innermost first. */
416 static void
418 {
426 current_template_parms
432 NULL);
434 {
443 {
450 /* Push the CONST_DECL. */
456 }
457 }
458 }
460 /* Restore the template parameter context for a member template, a
461 friend template defined in a class definition, or a non-template
462 member of template class. */
464 void
466 {
467 tree parms;
472 {
475 /* Disregard full specializations (c++/60999). */
478 }
481 {
486 {
489 }
492 }
494 /* Remember how many levels of template parameters we pushed so that
495 we can pop them later. */
497 }
499 /* Undo the effects of maybe_begin_member_template_processing. */
501 void
503 {
512 {
516 }
517 }
519 /* Return a new template argument vector which contains all of ARGS,
520 but has as its innermost set of arguments the EXTRA_ARGS. */
522 static tree
524 {
525 tree new_args;
543 }
545 /* Like add_to_template_args, but only the outermost ARGS are added to
546 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
547 (EXTRA_ARGS) levels are added. This function is used to combine
548 the template arguments from a partial instantiation with the
549 template arguments used to attain the full instantiation from the
550 partial instantiation. */
552 static tree
554 {
555 tree new_args;
557 /* If there are more levels of EXTRA_ARGS than there are ARGS,
558 something very fishy is going on. */
561 /* If *all* the new arguments will be the EXTRA_ARGS, just return
562 them. */
566 /* For the moment, we make ARGS look like it contains fewer levels. */
571 /* Now, we restore ARGS to its full dimensions. */
575 }
577 /* Return the N levels of innermost template arguments from the ARGS. */
579 tree
581 {
582 tree new_args;
588 /* If N is 1, just return the innermost set of template arguments. */
592 /* If we're not removing anything, just return the arguments we were
593 given. */
599 /* Make a new set of arguments, not containing the outer arguments. */
606 }
608 /* The inverse of get_innermost_template_args: Return all but the innermost
609 EXTRA_LEVELS levels of template arguments from the ARGS. */
611 static tree
613 {
614 tree new_args;
620 /* If N is 1, just return the outermost set of template arguments. */
624 /* If we're not removing anything, just return the arguments we were
625 given. */
630 /* Make a new set of arguments, not containing the inner arguments. */
637 }
639 /* We've got a template header coming up; push to a new level for storing
640 the parms. */
642 void
644 {
645 /* We use a non-tag-transparent scope here, which causes pushtag to
646 put tags in this scope, rather than in the enclosing class or
647 namespace scope. This is the right thing, since we want
648 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
649 global template class, push_template_decl handles putting the
650 TEMPLATE_DECL into top-level scope. For a nested template class,
651 e.g.:
653 template <class T> struct S1 {
654 template <class T> struct S2 {};
655 };
657 pushtag contains special code to insert the TEMPLATE_DECL for S2
658 at the right scope. */
664 /* Add a dummy parameter level while we process the parameter list. */
665 current_template_parms
668 current_template_parms);
669 }
671 /* This routine is called when a specialization is declared. If it is
672 invalid to declare a specialization here, an error is reported and
673 false is returned, otherwise this routine will return true. */
675 static bool
677 {
680 /* [temp.expl.spec]
682 An explicit specialization shall be declared in the namespace of
683 which the template is a member, or, for member templates, in the
684 namespace of which the enclosing class or enclosing class
685 template is a member. An explicit specialization of a member
686 function, member class or static data member of a class template
687 shall be declared in the namespace of which the class template
688 is a member. */
690 {
693 }
695 /* [temp.expl.spec]
697 In an explicit specialization declaration for a member of a class
698 template or a member template that appears in namespace scope,
699 the member template and some of its enclosing class templates may
700 remain unspecialized, except that the declaration shall not
701 explicitly specialize a class member template if its enclosing
702 class templates are not explicitly specialized as well. */
704 {
707 }
710 }
712 /* We've just seen template <>. */
714 bool
716 {
720 }
722 /* Called at then end of processing a declaration preceded by
723 template<>. */
725 void
727 {
730 }
732 /* Any template <>'s that we have seen thus far are not referring to a
733 function specialization. */
735 void
737 {
740 }
742 /* We've just seen a template header. If SPECIALIZATION is nonzero,
743 it was of the form template <>. */
745 static void
747 {
749 template_header_count++;
750 }
752 /* We're beginning an explicit instantiation. */
754 void
756 {
759 }
762 void
764 {
767 }
769 /* An explicit specialization or partial specialization of TMPL is being
770 declared. Check that the namespace in which the specialization is
771 occurring is permissible. Returns false iff it is invalid to
772 specialize TMPL in the current namespace. */
774 static bool
776 {
779 /* [tmpl.expl.spec]
781 An explicit specialization shall be declared in a namespace enclosing the
782 specialized template. An explicit specialization whose declarator-id is
783 not qualified shall be declared in the nearest enclosing namespace of the
784 template, or, if the namespace is inline (7.3.1), any namespace from its
785 enclosing namespace set. */
788 {
791 }
794 /* Same or enclosing namespace. */
796 else
797 {
803 }
804 }
806 /* SPEC is an explicit instantiation. Check that it is valid to
807 perform this explicit instantiation in the current namespace. */
809 static void
811 {
812 tree ns;
814 /* DR 275: An explicit instantiation shall appear in an enclosing
815 namespace of its template. */
821 }
823 // Returns the type of a template specialization only if that
824 // specialization needs to be defined. Otherwise (e.g., if the type has
825 // already been defined), the function returns NULL_TREE.
826 static tree
828 {
829 // An implicit instantiation of an incomplete type implies
830 // the definition of a new class template.
831 //
832 // template<typename T>
833 // struct S;
834 //
835 // template<typename T>
836 // struct S<T*>;
837 //
838 // Here, S<T*> is an implicit instantiation of S whose type
839 // is incomplete.
843 // It can also be the case that TYPE is a completed specialization.
844 // Continuing the previous example, suppose we also declare:
845 //
846 // template<typename T>
847 // requires Integral<T>
848 // struct S<T*>;
849 //
850 // Here, S<T*> refers to the specialization S<T*> defined
851 // above. However, we need to differentiate definitions because
852 // we intend to define a new partial specialization. In this case,
853 // we rely on the fact that the constraints are different for
854 // this declaration than that above.
855 //
856 // Note that we also get here for injected class names and
857 // late-parsed template definitions. We must ensure that we
858 // do not create new type declarations for those cases.
860 {
864 // If there are no template parameters, this cannot be a new
865 // partial template specializtion?
869 // The injected-class-name is not a new partial specialization.
873 // If the constraints are not the same as those of the primary
874 // then, we can probably create a new specialization.
878 {
882 }
884 // Also, if there's a pre-existing specialization with matching
885 // constraints, then this also isn't new.
888 {
896 }
898 // Create a new type node (and corresponding type decl)
899 // for the newly declared specialization.
904 /* We only need a separate type node for storing the definition of this
905 partial specialization; uses of S<T*> are unconstrained, so all are
906 equivalent. So keep TYPE_CANONICAL the same. */
909 // Build the corresponding type decl.
915 }
918 }
920 /* The TYPE is being declared. If it is a template type, that means it
921 is a partial specialization. Do appropriate error-checking. */
923 tree
925 {
926 tree context;
931 /* A lambda that appears in specialization context is not itself a
932 specialization. */
937 {
941 }
946 {
952 else
955 }
957 {
958 /* This is for ordinary explicit specialization and partial
959 specialization of a template class such as:
961 template <> class C<int>;
963 or:
965 template <class T> class C<T*>;
967 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
970 {
977 {
982 }
983 }
989 /* Trying to define a specialization either without a template<> header
990 or in an inappropriate place. We've already given an error, so just
991 bail now so we don't actually define the specialization. */
993 }
999 {
1000 /* This is for an explicit specialization of member class
1001 template according to [temp.expl.spec/18]:
1003 template <> template <class U> class C<int>::D;
1005 The context `C<int>' must be an implicit instantiation.
1006 Otherwise this is just a member class template declared
1007 earlier like:
1009 template <> class C<int> { template <class U> class D; };
1010 template <> template <class U> class C<int>::D;
1012 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1013 while in the second case, `C<int>::D' is a primary template
1014 and `C<T>::D' may not exist. */
1018 {
1019 tree t;
1024 {
1029 }
1031 /* Check for invalid specialization after instantiation:
1033 template <> template <> class C<int>::D<int>;
1034 template <> template <class U> class C<int>::D; */
1038 {
1042 {
1043 /* We already have a full specialization of this partial
1044 instantiation, or a full specialization has been
1045 looked up but not instantiated. Reassign it to the
1046 new member specialization template. */
1047 spec_entry elt;
1059 spec_entry **slot
1064 }
1065 else
1066 /* But if we've had an implicit instantiation, that's a
1067 problem ([temp.expl.spec]/6). */
1070 }
1072 /* Mark TYPE as a specialization. And as a result, we only
1073 have one level of template argument for the innermost
1074 class template. */
1079 }
1080 }
1082 {
1083 /* Someday C++0x may allow for enum template specialization. */
1088 else
1089 {
1092 }
1093 }
1096 }
1098 /* Returns nonzero if we can optimize the retrieval of specializations
1099 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1100 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1104 {
1107 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1108 parameter. */
1110 /* The optimized lookup depends on the fact that the
1111 template arguments for the member function template apply
1112 purely to the containing class, which is not true if the
1113 containing class is an explicit or partial
1114 specialization. */
1118 /* It is possible to have a template that is not a member
1119 template and is not a member of a template class:
1121 template <typename T>
1122 struct S { friend A::f(); };
1124 Here, the friend function is a template, but the context does
1125 not have template information. The optimized lookup relies
1126 on having ARGS be the template arguments for both the class
1127 and the function template. */
1129 }
1131 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1132 gone through coerce_template_parms by now. */
1134 static void
1136 {
1139 {
1142 {
1149 /* Allow typedefs on the type of a non-type argument, since a
1151 else
1153 }
1154 }
1156 }
1158 /* Retrieve the specialization (in the sense of [temp.spec] - a
1159 specialization is either an instantiation or an explicit
1160 specialization) of TMPL for the given template ARGS. If there is
1161 no such specialization, return NULL_TREE. The ARGS are a vector of
1162 arguments, or a vector of vectors of arguments, in the case of
1163 templates with more than one level of parameters.
1165 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1166 then we search for a partial specialization matching ARGS. This
1167 parameter is ignored if TMPL is not a class template.
1169 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1170 result is a NONTYPE_ARGUMENT_PACK. */
1172 static tree
1174 {
1184 /* There should be as many levels of arguments as there are
1185 levels of parameters. */
1194 /* Lambda functions in templates aren't instantiated normally, but through
1195 tsubst_lambda_expr. */
1200 {
1201 /* The template arguments actually apply to the containing
1202 class. Find the class specialization with those
1203 arguments. */
1205 tree class_specialization
1210 /* Find the instance of TMPL. */
1213 {
1216 /* using-declarations can add base methods to the method vec,
1217 and we don't want those here. */
1220 }
1222 }
1223 else
1224 {
1226 spec_entry elt;
1235 else
1243 }
1246 }
1248 /* Like retrieve_specialization, but for local declarations. */
1250 tree
1252 {
1258 }
1260 /* Returns nonzero iff DECL is a specialization of TMPL. */
1262 int
1264 {
1265 tree t;
1268 {
1274 }
1275 else
1276 {
1285 }
1288 }
1290 /* Returns nonzero iff DECL is a specialization of friend declaration
1291 FRIEND_DECL according to [temp.friend]. */
1293 bool
1295 {
1302 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1303 of a template class, we want to check if DECL is a specialization
1304 if this. */
1308 {
1309 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1312 }
1317 /* There is nothing to do if this is not a template friend. */
1324 /* [temp.friend/6]
1325 A member of a class template may be declared to be a friend of a
1326 non-template class. In this case, the corresponding member of
1327 every specialization of the class template is a friend of the
1328 class granting friendship.
1330 For example, given a template friend declaration
1332 template <class T> friend void A<T>::f();
1334 the member function below is considered a friend
1336 template <> struct A<int> {
1337 void f();
1338 };
1340 For this type of template friend, TEMPLATE_DEPTH below will be
1341 nonzero. To determine if DECL is a friend of FRIEND, we first
1342 check if the enclosing class is a specialization of another. */
1349 {
1350 /* Next, we check the members themselves. In order to handle
1351 a few tricky cases, such as when FRIEND_DECL's are
1353 template <class T> friend void A<T>::g(T t);
1354 template <class T> template <T t> friend void A<T>::h();
1356 and DECL's are
1358 void A<int>::g(int);
1359 template <int> void A<int>::h();
1361 we need to figure out ARGS, the template arguments from
1362 the context of DECL. This is required for template substitution
1363 of `T' in the function parameter of `g' and template parameter
1364 of `h' in the above examples. Here ARGS corresponds to `int'. */
1371 {
1373 {
1376 else
1378 current_depth++;
1379 }
1381 }
1384 {
1386 tree friend_type;
1387 tree decl_type;
1388 tree friend_args_type;
1389 tree decl_args_type;
1391 /* Make sure that both DECL and FRIEND_DECL are templates or
1392 non-templates. */
1398 {
1399 /* If both are templates, check template parameter list. */
1400 tree friend_parms
1405 friend_parms))
1409 }
1410 else
1418 /* Check if return types match. */
1422 /* Check if function parameter types match, ignoring the
1423 `this' parameter. */
1432 }
1433 else
1434 {
1435 /* DECL is a TYPE_DECL */
1439 /* Make sure that both DECL and FRIEND_DECL are templates or
1440 non-templates. */
1441 is_template
1448 {
1449 tree friend_parms;
1450 /* If both are templates, check the name of the two
1451 TEMPLATE_DECL's first because is_friend didn't. */
1456 /* Now check template parameter list. */
1457 friend_parms
1460 return comp_template_parms
1462 friend_parms);
1463 }
1464 else
1467 }
1468 }
1470 }
1472 /* Register the specialization SPEC as a specialization of TMPL with
1473 the indicated ARGS. IS_FRIEND indicates whether the specialization
1474 is actually just a friend declaration. Returns SPEC, or an
1475 equivalent prior declaration, if available.
1477 We also store instantiations of field packs in the hash table, even
1478 though they are not themselves templates, to make lookup easier. */
1480 static tree
1482 hashval_t hash)
1483 {
1484 tree fn;
1486 spec_entry elt;
1494 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1495 register it; we want the corresponding TEMPLATE_DECL instead.
1496 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1497 the more obvious `uses_template_parms (spec)' to avoid problems
1498 with default function arguments. In particular, given
1499 something like this:
1501 template <class T> void f(T t1, T t = T())
1503 the default argument expression is not substituted for in an
1504 instantiation unless and until it is actually needed. */
1508 /* We don't put these specializations in the hash table, but we might
1509 want to give an error about a mismatch. */
1511 else
1512 {
1520 slot =
1524 else
1526 }
1528 /* We can sometimes try to re-register a specialization that we've
1529 already got. In particular, regenerate_decl_from_template calls
1530 duplicate_decls which will update the specialization list. But,
1531 we'll still get called again here anyhow. It's more convenient
1532 to simply allow this than to try to prevent it. */
1536 {
1538 {
1541 {
1543 fn);
1545 }
1546 else
1547 {
1548 tree clone;
1549 /* This situation should occur only if the first
1550 specialization is an implicit instantiation, the
1551 second is an explicit specialization, and the
1552 implicit instantiation has not yet been used. That
1553 situation can occur if we have implicitly
1554 instantiated a member function and then specialized
1555 it later.
1557 We can also wind up here if a friend declaration that
1558 looked like an instantiation turns out to be a
1559 specialization:
1561 template <class T> void foo(T);
1562 class S { friend void foo<>(int) };
1563 template <> void foo(int);
1565 We transform the existing DECL in place so that any
1566 pointers to it become pointers to the updated
1567 declaration.
1569 If there was a definition for the template, but not
1570 for the specialization, we want this to look as if
1571 there were no definition, and vice versa. */
1574 /* The call to duplicate_decls will have applied
1575 [temp.expl.spec]:
1577 An explicit specialization of a function template
1578 is inline only if it is explicitly declared to be,
1579 and independently of whether its function template
1580 is.
1582 to the primary function; now copy the inline bits to
1583 the various clones. */
1585 {
1592 }
1596 }
1597 }
1599 {
1602 /* We've already complained in duplicate_decls. */
1606 /* Dup decl failed, but this is a new definition. Set the
1607 line number so any errors match this new
1608 definition. */
1612 }
1613 }
1617 /* A specialization must be declared in the same namespace as the
1618 template it is specializing. */
1624 {
1633 /* If TMPL is a forward declaration of a template function, keep a list
1634 of all specializations in case we need to reassign them to a friend
1635 template later in tsubst_friend_function.
1637 Also keep a list of all variable template instantiations so that
1638 process_partial_specialization can check whether a later partial
1639 specialization would have used it. */
1642 }
1645 }
1647 /* Returns true iff two spec_entry nodes are equivalent. */
1651 bool
1653 {
1660 /* tmpl could be a FIELD_DECL for a capture pack. */
1664 {
1665 /* Partial specializations of a variable template can be distinguished by
1666 constraints. */
1670 }
1674 }
1676 /* Returns a hash for a template TMPL and template arguments ARGS. */
1678 static hashval_t
1680 {
1683 }
1685 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1686 ignoring SPEC. */
1688 hashval_t
1690 {
1692 }
1694 /* Recursively calculate a hash value for a template argument ARG, for use
1695 in the hash tables of template specializations. */
1697 hashval_t
1699 {
1719 {
1727 {
1732 }
1754 {
1758 {
1761 }
1763 }
1767 {
1770 }
1781 val = iterative_hash_template_arg
1793 val);
1795 val);
1804 /* A lambda can't appear in a template arg, but don't crash on
1805 erroneous input. */
1817 /* Now hash operands as usual. */
1822 }
1825 {
1828 {
1829 // We want an alias specialization that survived strip_typedefs
1830 // to hash differently from its TYPE_CANONICAL, to avoid hash
1831 // collisions that compare as different in template_args_equal.
1832 // These could be dependent specializations that strip_typedefs
1833 // left alone, or untouched specializations because
1834 // coerce_template_parms returns the unconverted template
1835 // arguments if it sees incomplete argument packs.
1838 }
1841 val);
1844 /* Otherwise just compare the types during lookup. */
1853 {
1858 }
1859 }
1862 }
1864 /* Unregister the specialization SPEC as a specialization of TMPL.
1865 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1866 if the SPEC was listed as a specialization of TMPL.
1868 Note that SPEC has been ggc_freed, so we can't look inside it. */
1870 bool
1872 {
1874 spec_entry elt;
1882 {
1887 }
1890 }
1892 /* Like register_specialization, but for local declarations. We are
1893 registering SPEC, an instantiation of TMPL. */
1895 void
1897 {
1900 }
1902 /* TYPE is a class type. Returns true if TYPE is an explicitly
1903 specialized class. */
1905 bool
1907 {
1911 }
1913 /* Print the list of functions at FNS, going through all the overloads
1914 for each element of the list. Alternatively, FNS can not be a
1915 TREE_LIST, in which case it will be printed together with all the
1916 overloads.
1918 MORE and *STR should respectively be FALSE and NULL when the function
1919 is called from the outside. They are used internally on recursive
1920 calls. print_candidates manages the two parameters and leaves NULL
1921 in *STR when it ends. */
1923 static void
1925 {
1929 else
1931 {
1937 {
1940 else
1943 }
1945 }
1946 }
1948 /* Print the list of candidate FNS in an error message. FNS can also
1949 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1951 void
1953 {
1957 }
1959 /* Get a (possibly) constrained template declaration for the
1960 purpose of ordering candidates. */
1961 static tree
1963 {
1969 }
1971 /* Among candidates having the same signature, return the
1972 most constrained or NULL_TREE if there is no best candidate.
1973 If the signatures of candidates vary (e.g., template
1974 specialization vs. member function), then there can be no
1975 most constrained.
1977 Note that we don't compare constraints on the functions
1978 themselves, but rather those of their templates. */
1979 static tree
1981 {
1982 // Try to find the best candidate in a first pass.
1985 {
1992 }
1994 // Verify that the champ is better than previous candidates.
1999 }
2002 }
2005 /* Returns the template (one of the functions given by TEMPLATE_ID)
2006 which can be specialized to match the indicated DECL with the
2007 explicit template args given in TEMPLATE_ID. The DECL may be
2008 NULL_TREE if none is available. In that case, the functions in
2009 TEMPLATE_ID are non-members.
2011 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2012 specialization of a member template.
2014 The TEMPLATE_COUNT is the number of references to qualifying
2015 template classes that appeared in the name of the function. See
2016 check_explicit_specialization for a more accurate description.
2018 TSK indicates what kind of template declaration (if any) is being
2019 declared. TSK_TEMPLATE indicates that the declaration given by
2020 DECL, though a FUNCTION_DECL, has template parameters, and is
2021 therefore a template function.
2023 The template args (those explicitly specified and those deduced)
2024 are output in a newly created vector *TARGS_OUT.
2026 If it is impossible to determine the result, an error message is
2027 issued. The error_mark_node is returned to indicate failure. */
2029 static tree
2031 tree decl,
2035 tmpl_spec_kind tsk)
2036 {
2037 tree fns;
2038 tree targs;
2039 tree explicit_targs;
2042 /* A TREE_LIST of templates of which DECL may be a specialization.
2043 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2044 corresponding TREE_PURPOSE is the set of template arguments that,
2045 when used to instantiate the template, would produce a function
2046 with the signature of DECL. */
2056 /* We shouldn't be specializing a member template of an
2057 unspecialized class template; we already gave an error in
2058 check_specialization_scope, now avoid crashing. */
2061 {
2064 }
2072 /* Check for baselinks. */
2077 {
2080 }
2082 {
2085 }
2087 /* Count the number of template headers specified for this
2088 specialization. */
2098 {
2101 tf_warning_or_error,
2105 }
2107 {
2111 {
2112 tree decl_arg_types;
2113 tree fn_arg_types;
2114 tree insttype;
2116 /* In case of explicit specialization, we need to check if
2117 the number of template headers appearing in the specialization
2118 is correct. This is usually done in check_explicit_specialization,
2119 but the check done there cannot be exhaustive when specializing
2120 member functions. Consider the following code:
2122 template <> void A<int>::f(int);
2123 template <> template <> void A<int>::f(int);
2125 Assuming that A<int> is not itself an explicit specialization
2126 already, the first line specializes "f" which is a non-template
2127 member function, whilst the second line specializes "f" which
2128 is a template member function. So both lines are syntactically
2129 correct, and check_explicit_specialization does not reject
2130 them.
2132 Here, we can do better, as we are matching the specialization
2133 against the declarations. We count the number of template
2134 headers, and we check if they match TEMPLATE_COUNT + 1
2135 (TEMPLATE_COUNT is the number of qualifying template classes,
2136 plus there must be another header for the member template
2137 itself).
2139 Notice that if header_count is zero, this is not a
2140 specialization but rather a template instantiation, so there
2141 is no check we can perform here. */
2145 /* Check that the number of template arguments at the
2146 innermost level for DECL is the same as for FN. */
2154 /* DECL might be a specialization of FN. */
2158 /* For a non-static member function, we need to make sure
2159 that the const qualification is the same. Since
2160 get_bindings does not try to merge the "this" parameter,
2161 we must do the comparison explicitly. */
2167 /* Skip the "this" parameter and, for constructors of
2168 classes with virtual bases, the VTT parameter. A
2169 full specialization of a constructor will have a VTT
2170 parameter, but a template never will. */
2171 decl_arg_types
2173 fn_arg_types
2176 /* Function templates cannot be specializations; there are
2177 no partial specializations of functions. Therefore, if
2178 the type of DECL does not match FN, there is no
2179 match.
2181 Note that it should never be the case that we have both
2182 candidates added here, and for regular member functions
2183 below. */
2185 {
2189 }
2191 /* See whether this function might be a specialization of this
2192 template. Suppress access control because we might be trying
2193 to make this specialization a friend, and we have already done
2194 access control for the declaration of the specialization. */
2200 /* We cannot deduce template arguments that when used to
2201 specialize TMPL will produce DECL. */
2204 /* Remove, from the set of candidates, all those functions
2205 whose constraints are not satisfied. */
2209 // Then, try to form the new function type.
2213 fn_arg_types
2218 /* Save this template, and the arguments deduced. */
2220 }
2222 /* FN is an ordinary member function, and we need a
2223 specialization of a member template. */
2224 ;
2226 /* We can get IDENTIFIER_NODEs here in certain erroneous
2227 cases. */
2228 ;
2230 /* This is just an ordinary non-member function. Nothing can
2231 be a specialization of that. */
2232 ;
2234 /* Cannot specialize functions that are created implicitly. */
2235 ;
2236 else
2237 {
2238 tree decl_arg_types;
2240 /* This is an ordinary member function. However, since
2241 we're here, we can assume its enclosing class is a
2242 template class. For example,
2244 template <typename T> struct S { void f(); };
2245 template <> void S<int>::f() {}
2247 Here, S<int>::f is a non-template, but S<int> is a
2248 template class. If FN has the same type as DECL, we
2249 might be in business. */
2252 /* Its enclosing class is an explicit specialization
2253 of a template class. This is not a candidate. */
2258 /* The return types differ. */
2261 /* Adjust the type of DECL in case FN is a static member. */
2268 decl_arg_types))
2271 // If the deduced arguments do not satisfy the constraints,
2272 // this is not a candidate.
2276 // Add the candidate.
2278 }
2279 }
2282 {
2283 /* We have:
2285 [temp.expl.spec]
2287 It is possible for a specialization with a given function
2288 signature to be instantiated from more than one function
2289 template. In such cases, explicit specification of the
2290 template arguments must be used to uniquely identify the
2291 function template specialization being specialized.
2293 Note that here, there's no suggestion that we're supposed to
2294 determine which of the candidate templates is most
2295 specialized. However, we, also have:
2297 [temp.func.order]
2299 Partial ordering of overloaded function template
2300 declarations is used in the following contexts to select
2301 the function template to which a function template
2302 specialization refers:
2304 -- when an explicit specialization refers to a function
2305 template.
2307 So, we do use the partial ordering rules, at least for now.
2308 This extension can only serve to make invalid programs valid,
2309 so it's safe. And, there is strong anecdotal evidence that
2310 the committee intended the partial ordering rules to apply;
2311 the EDG front end has that behavior, and John Spicer claims
2312 that the committee simply forgot to delete the wording in
2313 [temp.expl.spec]. */
2316 {
2319 }
2320 }
2322 // Concepts allows multiple declarations of member functions
2323 // with the same signature. Like above, we need to rely on
2324 // on the partial ordering of those candidates to determine which
2325 // is the best.
2327 {
2329 {
2332 }
2333 }
2336 {
2343 else
2346 }
2350 {
2356 }
2358 /* We have one, and exactly one, match. */
2360 {
2364 // Propagate the candidate's constraints to the declaration.
2367 /* DECL is a re-declaration or partial instantiation of a template
2368 function. */
2371 /* It was a specialization of an ordinary member function in a
2372 template class. */
2374 }
2376 /* It was a specialization of a template. */
2379 {
2384 }
2385 else
2388 }
2390 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2391 but with the default argument values filled in from those in the
2392 TMPL_TYPES. */
2394 static tree
2396 tree tmpl_types)
2397 {
2398 tree new_spec_types;
2406 /* Substitute into the rest of the list. */
2407 new_spec_types =
2411 /* Add the default argument for this parameter. */
2414 new_spec_types);
2415 }
2417 /* DECL is an explicit specialization. Replicate default arguments
2418 from the template it specializes. (That way, code like:
2420 template <class T> void f(T = 3);
2421 template <> void f(double);
2422 void g () { f (); }
2424 works, as required.) An alternative approach would be to look up
2425 the correct default arguments at the call-site, but this approach
2426 is consistent with how implicit instantiations are handled. */
2428 static void
2430 {
2431 tree tmpl;
2432 tree spec_types;
2433 tree tmpl_types;
2434 tree new_spec_types;
2435 tree old_type;
2436 tree new_type;
2437 tree t;
2442 /* See if there's anything we need to do. */
2455 {
2456 /* Remove the this pointer, but remember the object's type for
2457 CV quals. */
2463 {
2464 /* DECL may contain more parameters than TMPL due to the extra
2465 in-charge parameter in constructors and destructors. */
2468 }
2470 {
2473 }
2474 }
2476 /* Compute the merged default arguments. */
2477 new_spec_types =
2480 /* Compute the new FUNCTION_TYPE. */
2482 {
2486 new_spec_types);
2489 /* Put the in-charge parameter back. */
2492 new_spec_types);
2496 new_spec_types);
2497 }
2498 else
2500 new_spec_types);
2510 }
2512 /* Return the number of template headers we expect to see for a definition
2513 or specialization of CTYPE or one of its non-template members. */
2515 int
2517 {
2521 {
2522 /* You're supposed to have one `template <...>' for every
2523 template class, but you don't need one for a full
2524 specialization. For example:
2526 template <class T> struct S{};
2527 template <> struct S<int> { void f(); };
2528 void S<int>::f () {}
2530 is correct; there shouldn't be a `template <>' for the
2531 definition of `S<int>::f'. */
2533 /* If CTYPE does not have template information of any
2534 kind, then it is not a template, nor is it nested
2535 within a template. */
2543 }
2546 }
2548 /* Do a simple sanity check on the template headers that precede the
2549 variable declaration DECL. */
2551 void
2553 {
2558 {
2561 "variable templates only available with "
2564 // Namespace-scope variable templates should have a template header.
2566 }
2568 {
2570 "too many template headers for %qD "
2576 "members of an explicitly specialized class are defined "
2578 }
2579 }
2581 /* An explicit specialization whose declarator-id or class-head-name is not
2582 qualified shall be declared in the nearest enclosing namespace of the
2583 template, or, if the namespace is inline (7.3.1), any namespace from its
2584 enclosing namespace set.
2586 If the name declared in the explicit instantiation is an unqualified name,
2587 the explicit instantiation shall appear in the namespace where its template
2588 is declared or, if that namespace is inline (7.3.1), any namespace from its
2589 enclosing namespace set. */
2591 void
2593 {
2598 {
2604 /* This was allowed in C++98, so only pedwarn. */
2606 "outside its namespace must use a nested-name-"
2608 }
2609 }
2611 /* Check to see if the function just declared, as indicated in
2612 DECLARATOR, and in DECL, is a specialization of a function
2613 template. We may also discover that the declaration is an explicit
2614 instantiation at this point.
2616 Returns DECL, or an equivalent declaration that should be used
2617 instead if all goes well. Issues an error message if something is
2618 amiss. Returns error_mark_node if the error is not easily
2619 recoverable.
2621 FLAGS is a bitmask consisting of the following flags:
2623 2: The function has a definition.
2624 4: The function is a friend.
2626 The TEMPLATE_COUNT is the number of references to qualifying
2627 template classes that appeared in the name of the function. For
2628 example, in
2630 template <class T> struct S { void f(); };
2631 void S<int>::f();
2633 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2634 classes are not counted in the TEMPLATE_COUNT, so that in
2636 template <class T> struct S {};
2637 template <> struct S<int> { void f(); }
2638 template <> void S<int>::f();
2640 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2641 invalid; there should be no template <>.)
2643 If the function is a specialization, it is marked as such via
2644 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2645 is set up correctly, and it is added to the list of specializations
2646 for that template. */
2648 tree
2650 tree decl,
2653 {
2662 tmpl_spec_kind tsk;
2665 {
2668 else
2670 }
2671 else
2675 {
2678 {
2681 }
2683 {
2685 /* This could be something like:
2687 template <class T> void f(T);
2688 class S { friend void f<>(int); } */
2690 else
2691 {
2692 /* This case handles bogus declarations like template <>
2693 template <class T> void f<int>(); */
2696 declarator);
2698 }
2699 }
2703 /* The error has already been reported in
2704 check_specialization_scope. */
2710 /* Fall through. */
2723 decl);
2726 else
2730 /* Fall through. */
2736 /* In cases like template<> constexpr bool v = true;
2737 We'll give an error in check_template_variable. */
2743 else
2749 {
2750 /* This case handles bogus declarations like template <>
2751 template <class T> void f<int>(); */
2755 declarator);
2757 {
2758 /* Partial specialization of variable template. */
2762 }
2766 else
2770 ok:;
2771 }
2774 /* This is a specialization of a member template, without
2775 specialization the containing class. Something like:
2777 template <class T> struct S {
2778 template <class U> void f (U);
2779 };
2780 template <> template <class U> void S<int>::f(U) {}
2782 That's a specialization -- but of the entire template. */
2788 }
2791 /* This doesn't apply to variable templates. */
2794 {
2798 {
2802 }
2803 }
2806 {
2811 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2813 {
2814 tree fns;
2819 else
2820 {
2821 /* If there is no class context, the explicit instantiation
2822 must be at namespace scope. */
2825 /* Find the namespace binding, using the declaration
2826 context. */
2830 /* If lookup fails, look for a friend declaration so we can
2831 give a better diagnostic. */
2837 {
2840 }
2841 }
2844 }
2850 {
2852 /* A specialization in class scope. This is invalid,
2853 but the error will already have been flagged by
2854 check_specialization_scope. */
2856 else
2857 {
2858 /* It's not valid to write an explicit instantiation in
2859 class scope, e.g.:
2861 class C { template void f(); }
2863 This case is caught by the parser. However, on
2864 something like:
2866 template class C { void f(); };
2868 (which is invalid) we can get here. The error will be
2869 issued later. */
2870 ;
2871 }
2874 }
2877 {
2878 // We'll match variable templates in start_decl.
2882 /* Find the list of functions in ctype that have the same
2883 name as the declared function. */
2887 {
2891 {
2892 /* From [temp.expl.spec]:
2894 If such an explicit specialization for the member
2895 of a class template names an implicitly-declared
2896 special member function (clause _special_), the
2897 program is ill-formed.
2899 Similar language is found in [temp.explicit]. */
2902 }
2905 }
2907 /* For a type-conversion operator, We might be looking for
2908 `operator int' which will be a specialization of
2909 `operator T'. Grab all the conversion operators, and
2910 then select from them. */
2915 {
2918 }
2919 else
2921 }
2923 /* Figure out what exactly is being specialized at this point.
2924 Note that for an explicit instantiation, even one for a
2925 member function, we cannot tell a priori whether the
2926 instantiation is for a member template, or just a member
2927 function of a template class. Even if a member template is
2928 being instantiated, the member template arguments may be
2929 elided if they can be deduced from the rest of the
2930 declaration. */
2933 member_specialization,
2934 template_count,
2935 tsk);
2938 /* We couldn't figure out what this declaration was
2939 specializing. */
2941 else
2942 {
2945 {
2947 "friend declaration %qD is not visible to "
2951 }
2959 {
2960 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2961 is done by do_decl_instantiation later. */
2967 {
2968 /* If TMPL is not the most general template (for
2969 example, if TMPL is a friend template that is
2970 injected into namespace scope), then there will
2971 be too many levels of TARGS. Remove some of them
2972 here. */
2974 tree new_targs;
2981 }
2984 }
2986 /* If we thought that the DECL was a member function, but it
2987 turns out to be specializing a static member function,
2988 make DECL a static member function as well. */
2994 /* If this is a specialization of a member template of a
2995 template class, we want to return the TEMPLATE_DECL, not
2996 the specialization of it. */
2998 {
3003 {
3004 tree parm;
3008 /* We want to use the argument list specified in the
3009 definition, not in the original declaration. */
3014 }
3017 }
3019 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3025 /* Inherit default function arguments from the template
3026 DECL is specializing. */
3030 /* This specialization has the same protection as the
3031 template it specializes. */
3035 /* 7.1.1-1 [dcl.stc]
3037 A storage-class-specifier shall not be specified in an
3038 explicit specialization...
3040 The parser rejects these, so unless action is taken here,
3041 explicit function specializations will always appear with
3042 global linkage.
3044 The action recommended by the C++ CWG in response to C++
3045 defect report 605 is to make the storage class and linkage
3046 of the explicit specialization match the templated function:
3048 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3049 */
3051 {
3055 /* A concept cannot be specialized. */
3057 {
3059 gen_tmpl);
3061 }
3063 /* This specialization has the same linkage and visibility as
3064 the function template it specializes. */
3067 {
3070 }
3073 {
3076 }
3077 }
3079 /* If DECL is a friend declaration, declared using an
3080 unqualified name, the namespace associated with DECL may
3081 have been set incorrectly. For example, in:
3083 template <typename T> void f(T);
3084 namespace N {
3085 struct S { friend void f<int>(int); }
3086 }
3088 we will have set the DECL_CONTEXT for the friend
3089 declaration to N, rather than to the global namespace. */
3094 /* This is not really a declaration of a specialization.
3095 It's just the name of an instantiation. But, it's not
3096 a request for an instantiation, either. */
3099 /* A specialization is not necessarily COMDAT. */
3105 /* If this is a full specialization, register it so that we can find
3106 it again. Partial specializations will be registered in
3107 process_partial_specialization. */
3112 /* A 'structor should already have clones. */
3118 }
3119 }
3122 }
3124 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3125 parameters. These are represented in the same format used for
3126 DECL_TEMPLATE_PARMS. */
3128 int
3130 {
3131 const_tree p1;
3132 const_tree p2;
3140 {
3152 {
3156 /* If either of the template parameters are invalid, assume
3157 they match for the sake of error recovery. */
3170 }
3171 }
3174 /* One set of parameters has more parameters lists than the
3175 other. */
3179 }
3181 /* Determine whether PARM is a parameter pack. */
3183 bool
3185 {
3186 /* Determine if we have a non-type template parameter pack. */
3193 /* If this is a list of template parameters, we could get a
3194 TYPE_DECL or a TEMPLATE_DECL. */
3198 /* Otherwise it must be a type template parameter. */
3202 }
3204 /* Determine if T is a function parameter pack. */
3206 bool
3208 {
3212 }
3214 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3215 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3217 tree
3219 {
3226 }
3228 /* Return true iff the function parameter PARAM_DECL was expanded
3229 from the function parameter pack PACK. */
3231 bool
3233 {
3238 /* The parameter pack and its pack arguments have the same
3239 DECL_PARM_INDEX. */
3241 }
3243 /* Determine whether ARGS describes a variadic template args list,
3244 i.e., one that is terminated by a template argument pack. */
3246 static bool
3248 {
3250 tree last_parm;
3264 }
3266 /* Generate a new name for the parameter pack name NAME (an
3267 IDENTIFIER_NODE) that incorporates its */
3269 static tree
3271 {
3272 /* Munge the name to include the parameter index. */
3273 #define NUMBUF_LEN 128
3287 }
3289 /* Return true if T is a primary function, class or alias template
3290 instantiation. */
3292 bool
3294 {
3308 }
3310 /* Return true if PARM is a template template parameter. */
3312 bool
3314 {
3316 }
3318 /* Return true iff PARM is a DECL representing a type template
3319 parameter. */
3321 bool
3323 {
3328 }
3330 /* Return the template parameters of T if T is a
3331 primary template instantiation, NULL otherwise. */
3333 tree
3335 {
3340 parms = INNERMOST_TEMPLATE_PARMS
3344 }
3346 /* Return the template parameters of the LEVELth level from the full list
3347 of template parameters PARMS. */
3349 tree
3351 {
3352 tree p;
3363 }
3365 /* Returns the template arguments of T if T is a template instantiation,
3366 NULL otherwise. */
3368 tree
3370 {
3378 }
3380 /* Return the argument pack elements of T if T is a template argument pack,
3381 NULL otherwise. */
3383 tree
3385 {
3391 }
3393 /* True iff FN is a function representing a built-in variadic parameter
3394 pack. */
3396 bool
3398 {
3408 }
3410 /* True iff CALL is a call to a function representing a built-in variadic
3411 parameter pack. */
3413 static bool
3415 {
3419 }
3421 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3423 static tree
3425 tree in_decl)
3426 {
3432 {
3434 {
3437 }
3442 }
3443 else
3444 {
3448 /* Calculate the largest value of len that won't make the size of the vec
3449 overflow an int. The compiler will exceed resource limits long before
3450 this, but it seems a decent place to diagnose. */
3454 {
3459 }
3467 }
3468 }
3470 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3471 CALL. */
3473 static tree
3475 tree in_decl)
3476 {
3486 }
3488 /* Structure used to track the progress of find_parameter_packs_r. */
3489 struct find_parameter_pack_data
3490 {
3491 /* TREE_LIST that will contain all of the parameter packs found by
3492 the traversal. */
3495 /* Set of AST nodes that have been visited by the traversal. */
3498 /* True iff we're making a type pack expansion. */
3500 };
3502 /* Identifies all of the argument packs that occur in a template
3503 argument and appends them to the TREE_LIST inside DATA, which is a
3504 find_parameter_pack_data structure. This is a subroutine of
3505 make_pack_expansion and uses_parameter_packs. */
3506 static tree
3508 {
3514 /* Handle type aliases/typedefs. */
3516 {
3523 }
3525 /* Identify whether this is a parameter pack or not. */
3527 {
3535 /* FALLTHRU */
3537 /* If the placeholder appears in the decl-specifier-seq of a function
3538 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3539 is a pack expansion, the invented template parameter is a template
3540 parameter pack. */
3550 {
3551 /* We don't want to walk into the type of a PARM_DECL,
3552 because we don't want to see the type parameter pack. */
3555 }
3558 /* Look through a lambda capture proxy to the field pack. */
3561 {
3567 }
3569 {
3571 find_parameter_packs_r,
3574 }
3586 /* Not a parameter pack. */
3588 }
3591 {
3592 /* Add this parameter pack to the list. */
3594 }
3600 /* This switch statement will return immediately if we don't find a
3601 parameter pack. */
3603 {
3608 /* Check the template itself. */
3611 /* Check the template arguments. */
3625 /* Ignore the declaration of a capture proxy for a parameter pack. */
3633 /* Fall through. */
3678 {
3684 }
3687 {
3688 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3689 type_pack_expansion_p to false so that any placeholders
3690 within the expression don't get marked as parameter packs. */
3698 }
3702 }
3705 }
3707 /* Determines if the expression or type T uses any parameter packs. */
3708 bool
3710 {
3719 }
3721 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3722 representation a base-class initializer into a parameter pack
3723 expansion. If all goes well, the resulting node will be an
3724 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3725 respectively. */
3726 tree
3728 {
3729 tree result;
3738 {
3739 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3740 class initializer. In this case, the TREE_PURPOSE will be a
3741 _TYPE node (representing the base class expansion we're
3742 initializing) and the TREE_VALUE will be a TREE_LIST
3743 containing the initialization arguments.
3745 The resulting expansion looks somewhat different from most
3746 expansions. Rather than returning just one _EXPANSION, we
3747 return a TREE_LIST whose TREE_PURPOSE is a
3748 TYPE_PACK_EXPANSION containing the bases that will be
3749 initialized. The TREE_VALUE will be identical to the
3750 original TREE_VALUE, which is a list of arguments that will
3751 be passed to each base. We do not introduce any new pack
3752 expansion nodes into the TREE_VALUE (although it is possible
3753 that some already exist), because the TREE_PURPOSE and
3754 TREE_VALUE all need to be expanded together with the same
3755 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3756 resulting TREE_PURPOSE will mention the parameter packs in
3757 both the bases and the arguments to the bases. */
3758 tree purpose;
3759 tree value;
3762 /* Determine which parameter packs will be used by the base
3763 class expansion. */
3772 {
3775 arg);
3778 }
3781 {
3782 /* Collect the sets of parameter packs used in each of the
3783 initialization arguments. */
3785 {
3786 /* Determine which parameter packs will be expanded in this
3787 argument. */
3790 }
3791 }
3795 /* Create the pack expansion type for the base type. */
3801 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3802 they will rarely be compared to anything. */
3806 }
3811 /* Build the PACK_EXPANSION_* node. */
3812 result = for_types
3817 {
3818 /* Propagate type and const-expression information. */
3821 /* Mark this read now, since the expansion might be length 0. */
3823 }
3824 else
3825 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3826 they will rarely be compared to anything. */
3829 /* Determine which parameter packs will be expanded. */
3836 /* Make sure we found some parameter packs. */
3838 {
3840 {
3843 else
3845 }
3847 }
3853 }
3855 /* Checks T for any "bare" parameter packs, which have not yet been
3856 expanded, and issues an error if any are found. This operation can
3857 only be done on full expressions or types (e.g., an expression
3858 statement, "if" condition, etc.), because we could have expressions like:
3860 foo(f(g(h(args)))...)
3862 where "args" is a parameter pack. check_for_bare_parameter_packs
3863 should not be called for the subexpressions args, h(args),
3864 g(h(args)), or f(g(h(args))), because we would produce erroneous
3865 error messages.
3867 Returns TRUE and emits an error if there were bare parameter packs,
3868 returns FALSE otherwise. */
3869 bool
3871 {
3878 /* A lambda might use a parameter pack from the containing context. */
3892 {
3896 {
3907 else
3912 else
3916 }
3919 }
3922 }
3924 /* Expand any parameter packs that occur in the template arguments in
3925 ARGS. */
3926 tree
3928 {
3937 /* First, determine if we need to expand anything, and the number of
3938 slots we'll need. */
3940 {
3945 {
3949 else
3951 }
3952 else
3953 {
3955 num_result_args++;
3956 }
3957 }
3959 /* If no expansion is necessary, we're done. */
3963 /* Expand arguments. */
3966 non_default_args_count =
3969 {
3972 {
3979 }
3980 else
3981 {
3984 }
3985 }
3989 }
3991 /* Checks if DECL shadows a template parameter.
3993 [temp.local]: A template-parameter shall not be redeclared within its
3994 scope (including nested scopes).
3996 Emits an error and returns TRUE if the DECL shadows a parameter,
3997 returns FALSE otherwise. */
3999 bool
4001 {
4002 tree olddecl;
4004 /* If we're not in a template, we can't possibly shadow a template
4005 parameter. */
4009 /* Figure out what we're shadowing. */
4013 /* If there's no previous binding for this name, we're not shadowing
4014 anything, let alone a template parameter. */
4018 /* If we're not shadowing a template parameter, we're done. Note
4019 that OLDDECL might be an OVERLOAD (or perhaps even an
4020 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4021 node. */
4025 /* We check for decl != olddecl to avoid bogus errors for using a
4026 name inside a class. We check TPFI to avoid duplicate errors for
4027 inline member templates. */
4033 /* Don't complain about the injected class name, as we've already
4034 complained about the class itself. */
4041 else
4046 }
4048 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4049 ORIG_LEVEL, DECL, and TYPE. */
4051 static tree
4055 tree decl,
4056 tree type)
4057 {
4068 }
4070 /* Find the canonical type parameter for the given template type
4071 parameter. Returns the canonical type parameter, which may be TYPE
4072 if no such parameter existed. */
4074 static tree
4076 {
4077 tree list;
4091 else
4092 {
4096 }
4097 }
4099 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4100 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4101 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4102 new one is created. */
4104 static tree
4106 tsubst_flags_t complain)
4107 {
4112 {
4131 /* Template template parameters need this. */
4133 {
4140 }
4141 }
4144 }
4146 /* Process information from new template parameter PARM and append it
4147 to the LIST being built. This new parameter is a non-type
4148 parameter iff IS_NON_TYPE is true. This new parameter is a
4149 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4150 is in PARM_LOC. */
4152 tree
4155 {
4164 {
4168 {
4172 else
4174 }
4177 }
4180 {
4186 {
4187 /* [temp.param]
4189 The top-level cv-qualifiers on the template-parameter are
4190 ignored when determining its type. */
4195 && !is_parameter_pack
4196 /* If we're in a nested template parameter list, the template
4197 template parameter could be a parameter pack. */
4199 {
4200 /* This template parameter is not a parameter pack, but it
4201 should be. Complain about "bare" parameter packs. */
4204 /* Recover by calling this a parameter pack. */
4206 }
4207 }
4209 /* A template parameter is not modifiable. */
4218 processing_template_decl,
4223 }
4224 else
4225 {
4226 tree t;
4230 {
4232 /* This is for distinguishing between real templates and template
4233 template parameters */
4237 }
4238 else
4239 {
4241 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4244 }
4251 processing_template_decl,
4255 }
4259 /* Build requirements for the type/template parameter.
4260 This must be done after SET_DECL_TEMPLATE_PARM_P or
4261 process_template_parm could fail. */
4266 /* Build the parameter node linking the parameter declaration,
4267 its default argument (if any), and its constraints (if any). */
4272 }
4274 /* The end of a template parameter list has been reached. Process the
4275 tree list into a parameter vector, converting each parameter into a more
4276 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4277 as PARM_DECLs. */
4279 tree
4281 {
4286 /* Pop the dummy parameter level and add the real one. */
4289 current_template_parms
4294 {
4298 }
4303 }
4305 // Explicitly indicate the end of the template parameter list. We assume
4306 // that the current template parameters have been constructed and/or
4307 // managed explicitly, as when creating new template template parameters
4308 // from a shorthand constraint.
4309 void
4311 {
4313 }
4315 /* end_template_decl is called after a template declaration is seen. */
4317 void
4319 {
4325 /* This matches the pushlevel in begin_template_parm_list. */
4330 }
4332 /* Takes a TREE_LIST representing a template parameter and convert it
4333 into an argument suitable to be passed to the type substitution
4334 functions. Note that If the TREE_LIST contains an error_mark
4335 node, the returned argument is error_mark_node. */
4337 tree
4339 {
4352 {
4356 {
4357 /* Turn this argument into a TYPE_ARGUMENT_PACK
4358 with a single element, which expands T. */
4367 }
4368 }
4369 else
4370 {
4374 {
4375 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4376 with a single element, which expands T. */
4386 }
4387 else
4389 }
4391 }
4393 /* Given a single level of template parameters (a TREE_VEC), return it
4394 as a set of template arguments. */
4396 static tree
4398 {
4408 }
4410 /* Given a set of template parameters, return them as a set of template
4411 arguments. The template parameters are represented as a TREE_VEC, in
4412 the form documented in cp-tree.h for template arguments. */
4414 static tree
4416 {
4417 tree header;
4422 /* If there is only one level of template parameters, we do not
4423 create a TREE_VEC of TREE_VECs. Instead, we return a single
4424 TREE_VEC containing the arguments. */
4429 {
4434 else
4436 }
4439 }
4441 /* Within the declaration of a template, return the currently active
4442 template parameters as an argument TREE_VEC. */
4444 static tree
4446 {
4448 }
4450 /* Update the declared TYPE by doing any lookups which were thought to be
4451 dependent, but are not now that we know the SCOPE of the declarator. */
4453 tree
4455 {
4466 /* Don't bother building up the args in this case. */
4468 {
4469 /* tsubst in the args corresponding to the template parameters,
4470 including auto if present. Most things will be unchanged, but
4471 make_typename_type and tsubst_qualified_id will resolve
4472 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4475 tree pushed;
4477 {
4481 }
4486 }
4492 {
4495 else
4497 }
4499 }
4501 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4502 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4503 the new template is a member template. */
4505 tree
4507 {
4515 }
4517 struct template_parm_data
4518 {
4519 /* The level of the template parameters we are currently
4520 processing. */
4523 /* The index of the specialization argument we are currently
4524 processing. */
4527 /* An array whose size is the number of template parameters. The
4528 elements are nonzero if the parameter has been used in any one
4529 of the arguments processed so far. */
4532 /* An array whose size is the number of template arguments. The
4533 elements are nonzero if the argument makes use of template
4534 parameters of this level. */
4536 };
4538 /* Subroutine of push_template_decl used to see if each template
4539 parameter in a partial specialization is used in the explicit
4540 argument list. If T is of the LEVEL given in DATA (which is
4541 treated as a template_parm_data*), then DATA->PARMS is marked
4542 appropriately. */
4544 static int
4546 {
4554 {
4557 }
4559 /* In C++17 the type of a non-type argument is a deduced context. */
4564 data,
4565 NULL,
4568 /* Return zero so that for_each_template_parm will continue the
4569 traversal of the tree; we want to mark *every* template parm. */
4571 }
4573 /* Process the partial specialization DECL. */
4575 static tree
4577 {
4584 tree inner_parms;
4585 tree inst;
4595 /* A concept cannot be specialized. */
4597 {
4600 }
4605 /* We check that each of the template parameters given in the
4606 partial specialization is used in the argument list to the
4607 specialization. For example:
4609 template <class T> struct S;
4610 template <class T> struct S<T*>;
4612 The second declaration is OK because `T*' uses the template
4613 parameter T, whereas
4615 template <class T> struct S<int>;
4617 is no good. Even trickier is:
4619 template <class T>
4620 struct S1
4621 {
4622 template <class U>
4623 struct S2;
4624 template <class U>
4625 struct S2<T>;
4626 };
4628 The S2<T> declaration is actually invalid; it is a
4629 full-specialization. Of course,
4631 template <class U>
4632 struct S2<T (*)(U)>;
4634 or some such would have been OK. */
4642 {
4647 NULL,
4649 }
4652 {
4653 /* One of the template parms was not used in a deduced context in the
4654 specialization. */
4656 {
4660 }
4664 }
4669 /* [temp.class.spec]
4671 The argument list of the specialization shall not be identical to
4672 the implicit argument list of the primary template. */
4673 tree main_args
4676 && (!flag_concepts
4679 {
4683 else
4687 }
4689 /* A partial specialization that replaces multiple parameters of the
4690 primary template with a pack expansion is less specialized for those
4691 parameters. */
4693 {
4695 "primary template because it replaces multiple parameters "
4698 /* Avoid crash in process_partial_specialization. */
4700 }
4702 /* If we aren't in a dependent class, we can actually try deduction. */
4704 /* FIXME we should be able to handle a partial specialization of a
4705 partial instantiation, but currently we can't (c++/41727). */
4708 {
4712 maintmpl);
4713 }
4715 /* [temp.class.spec]
4717 A partially specialized non-type argument expression shall not
4718 involve template parameters of the partial specialization except
4719 when the argument expression is a simple identifier.
4721 The type of a template parameter corresponding to a specialized
4722 non-type argument shall not be dependent on a parameter of the
4723 specialization.
4725 Also, we verify that pack expansions only occur at the
4726 end of the argument list. */
4730 {
4737 {
4738 /* Extract the arguments from the argument pack. We'll be
4739 iterating over these in the following loop. */
4742 }
4745 {
4747 /* Get the Jth argument in the parameter pack. */
4751 {
4752 /* Pack expansions must come at the end of the
4753 argument list. */
4756 {
4760 else
4763 }
4764 }
4767 /* We only care about the pattern. */
4773 /* This next two lines are the `argument expression is not just a
4774 simple identifier' condition and also the `specialized
4775 non-type argument' bit. */
4779 {
4783 arg);
4784 else
4785 {
4786 /* Look at the corresponding template parameter,
4787 marking which template parameters its type depends
4788 upon. */
4792 {
4793 /* We haven't yet initialized TPD2. Do so now. */
4795 /* The number of parameters here is the number in the
4796 main template, which, as checked in the assertion
4797 above, is NARGS. */
4801 }
4803 /* Mark the template parameters. But this time, we're
4804 looking for the template parameters of the main
4805 template, not in the specialization. */
4812 NULL,
4816 {
4817 /* The type depended on some template parameters.
4818 If they are fully specialized in the
4819 specialization, that's OK. */
4828 "type %qT of template argument %qE depends "
4830 "type %qT of template argument %qE depends "
4832 type,
4833 arg);
4834 }
4835 }
4836 }
4837 }
4838 }
4840 /* We should only get here once. */
4844 // Build the template decl.
4853 /* Give template template parms a DECL_CONTEXT of the template
4854 for which they are a parameter. */
4856 {
4860 }
4863 /* We didn't register this in check_explicit_specialization so we could
4864 wait until the constraints were set. */
4866 else
4876 {
4882 {
4890 "declaration of %qD ambiguates earlier template "
4894 "partial specialization of %qD after instantiation "
4896 }
4897 }
4900 }
4902 /* PARM is a template parameter of some form; return the corresponding
4903 TEMPLATE_PARM_INDEX. */
4905 static tree
4907 {
4920 }
4922 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4923 parameter packs used by the template parameter PARM. */
4925 static void
4927 {
4928 /* A type parm can't refer to another parm. */
4932 {
4936 }
4943 }
4945 /* PARM is a template parameter pack. Return any parameter packs used in
4946 its type or the type of any of its template parameters. If there are
4947 any such packs, it will be instantiated into a fixed template parameter
4948 list by partial instantiation rather than be fully deduced. */
4950 tree
4952 {
4953 /* This can only be true in a member template. */
4956 /* This can only be true for a parameter pack. */
4959 /* A type parm can't refer to another parm. */
4973 }
4975 /* Check that a template declaration's use of default arguments and
4976 parameter packs is not invalid. Here, PARMS are the template
4977 parameters. IS_PRIMARY is true if DECL is the thing declared by
4978 a primary template. IS_PARTIAL is true if DECL is a partial
4979 specialization.
4981 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4982 declaration (but not a definition); 1 indicates a declaration, 2
4983 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4984 emitted for extraneous default arguments.
4986 Returns TRUE if there were no errors found, FALSE otherwise. */
4988 bool
4991 {
4994 tree parm_level;
4997 /* [temp.param]
4999 A default template-argument shall not be specified in a
5000 function template declaration or a function template definition, nor
5001 in the template-parameter-list of the definition of a member of a
5002 class template. */
5006 /* You can't have a function template declaration in a local
5007 scope, nor you can you define a member of a class template in a
5008 local scope. */
5016 /* A lambda doesn't have an explicit declaration; don't complain
5017 about the parms of the enclosing class. */
5024 /* If this is either a friend defined in the scope of the class
5025 or a member function. */
5031 /* And, if it was a member function, it really was defined in
5032 the scope of the class. */
5035 /* We already checked these parameters when the template was
5036 declared, so there's no need to do it again now. This function
5037 was defined in class scope, but we're processing its body now
5038 that the class is complete. */
5041 /* Core issue 226 (C++0x only): the following only applies to class
5042 templates. */
5045 {
5046 /* [temp.param]
5048 If a template-parameter has a default template-argument, all
5049 subsequent template-parameters shall have a default
5050 template-argument supplied. */
5052 {
5059 {
5069 {
5071 /* For better subsequent error-recovery, we indicate that
5072 there should have been a default argument. */
5075 }
5077 && !is_friend_decl
5078 /* Don't complain about an enclosing partial
5079 specialization. */
5084 /* A fixed parameter pack will be partially
5085 instantiated into a fixed length list. */
5087 {
5088 /* A primary class template can only have one
5089 parameter pack, at the end of the template
5090 parameter list. */
5098 }
5099 }
5100 }
5101 }
5104 || is_partial
5105 || !is_primary
5107 /* For an ordinary class template, default template arguments are
5108 allowed at the innermost level, e.g.:
5109 template <class T = int>
5110 struct S {};
5111 but, in a partial specialization, they're not allowed even
5112 there, as we have in [temp.class.spec]:
5114 The template parameter list of a specialization shall not
5115 contain default template argument values.
5117 So, for a partial specialization, or for a function template
5118 (in C++98/C++03), we look at all of them. */
5119 ;
5120 else
5121 /* But, for a primary class template that is not a partial
5122 specialization we look at all template parameters except the
5123 innermost ones. */
5126 /* Figure out what error message to issue. */
5141 else
5142 /* Per [temp.param]/9, "A default template-argument shall not be
5143 specified in the template-parameter-lists of the definition of
5144 a member of a class template that appears outside of the member's
5145 class.", thus if we aren't handling a member of a class template
5146 there is no need to examine the parameters. */
5150 /* If we're inside a class definition, there's no need to
5151 examine the parameters to the class itself. On the one
5152 hand, they will be checked when the class is defined, and,
5153 on the other, default arguments are valid in things like:
5154 template <class T = double>
5155 struct S { template <class U> void f(U); };
5156 Here the default argument for `S' has no bearing on the
5157 declaration of `f'. */
5159 else
5160 /* Check everything. */
5166 {
5173 {
5178 {
5180 {
5187 }
5189 /* Clear out the default argument so that we are not
5190 confused later. */
5192 }
5193 }
5195 /* At this point, if we're still interested in issuing messages,
5196 they must apply to classes surrounding the object declared. */
5200 }
5203 }
5205 /* Worker for push_template_decl_real, called via
5206 for_each_template_parm. DATA is really an int, indicating the
5207 level of the parameters we are interested in. If T is a template
5208 parameter of that level, return nonzero. */
5210 static int
5212 {
5218 else
5221 }
5223 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5224 DATA is really an int, indicating the innermost outer level of parameters.
5225 If T is a template parameter of that level or further out, return
5226 nonzero. */
5228 static int
5230 {
5236 else
5239 }
5241 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5242 parameters given by current_template_args, or reuses a
5243 previously existing one, if appropriate. Returns the DECL, or an
5244 equivalent one, if it is replaced via a call to duplicate_decls.
5246 If IS_FRIEND is true, DECL is a friend declaration. */
5248 tree
5250 {
5251 tree tmpl;
5252 tree args;
5253 tree info;
5254 tree ctx;
5258 /* True if the template is a member template, in the sense of
5259 [temp.mem]. */
5265 /* See if this is a partial specialization. */
5278 /* For a friend, we want the context of the friend function, not
5279 the type of which it is a friend. */
5283 /* In the case of a virtual function, we want the class in which
5284 it is defined. */
5286 else
5287 /* Otherwise, if we're currently defining some class, the DECL
5288 is assumed to be a member of the class. */
5297 /* See if this is a primary template. */
5300 /* A friend template that specifies a class context, i.e.
5301 template <typename T> friend void A<T>::f();
5302 is not primary. */
5307 else
5311 {
5318 {
5321 }
5323 {
5325 {
5328 }
5330 {
5331 /* [temp.mem]
5333 A destructor shall not be a member template. */
5336 }
5343 {
5344 /* [basic.stc.dynamic.allocation]
5346 An allocation function can be a function
5347 template. ... Template allocation functions shall
5348 have two or more parameters. */
5351 }
5352 }
5355 {
5356 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5359 {
5365 }
5366 }
5369 /* alias-declaration */
5373 else
5374 {
5377 }
5378 }
5380 /* Check to see that the rules regarding the use of default
5381 arguments are not being violated. */
5385 /* Ensure that there are no parameter packs in the type of this
5386 declaration that have not been expanded. */
5388 {
5389 /* Check each of the arguments individually to see if there are
5390 any bare parameter packs. */
5396 {
5399 {
5400 /* This is a PARM_DECL that contains unexpanded parameter
5401 packs. We have already complained about this in the
5402 check_for_bare_parameter_packs call, so just replace
5403 these types with ERROR_MARK_NODE. */
5406 }
5410 }
5412 /* Check for bare parameter packs in the return type and the
5413 exception specifiers. */
5415 /* Errors were already issued, set return type to int
5416 as the frontend doesn't expect error_mark_node as
5417 the return type. */
5421 }
5426 {
5429 }
5442 {
5447 /* If DECL is a TYPE_DECL for a class-template, then there won't
5448 be DECL_LANG_SPECIFIC. The information equivalent to
5449 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5453 {
5454 /* Since a template declaration already existed for this
5455 class-type, we must be redeclaring it here. Make sure
5456 that the redeclaration is valid. */
5458 current_template_parms,
5460 /* We don't need to create a new TEMPLATE_DECL; just use the
5461 one we already had. */
5463 }
5464 else
5465 {
5467 member_template_p);
5472 {
5473 /* A specialization of a member template of a template
5474 class. */
5478 }
5479 }
5480 }
5481 else
5482 {
5488 {
5491 }
5499 {
5500 tree new_tmpl;
5502 /* The declaration is a specialization of a member
5503 template, declared outside the class. Therefore, the
5504 innermost template arguments will be NULL, so we
5505 replace them with the arguments determined by the
5506 earlier call to check_explicit_specialization. */
5509 new_tmpl
5511 member_template_p);
5521 args,
5524 }
5526 /* Make sure the template headers we got make sense. */
5531 {
5536 }
5537 else
5539 {
5544 {
5548 else
5552 /* Avoid crash in import_export_decl. */
5555 }
5560 /* Can happen in erroneous input. */
5562 else
5564 }
5566 /* Check that the parms are used in the appropriate qualifying scopes
5567 in the declarator. */
5571 {
5577 /* Avoid crash in import_export_decl. */
5580 }
5581 }
5586 /* Push template declarations for global functions and types. Note
5587 that we do not try to push a global template friend declared in a
5588 template class; such a thing may well depend on the template
5589 parameters of the class. */
5592 {
5597 /* Hide template friend classes that haven't been declared yet. */
5599 {
5602 }
5603 }
5606 {
5611 /* Give template template parms a DECL_CONTEXT of the template
5612 for which they are a parameter. */
5615 {
5619 }
5625 }
5627 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5628 back to its most general template. If TMPL is a specialization,
5629 ARGS may only have the innermost set of arguments. Add the missing
5630 argument levels if necessary. */
5638 else
5639 {
5644 }
5647 && !is_friend
5650 /* Set DECL_COMDAT on template instantiations; if we force
5651 them to be emitted by explicit instantiation or -frepo,
5652 mark_needed will tell cgraph to do the right thing. */
5656 }
5658 tree
5660 {
5662 }
5664 /* FN is an inheriting constructor that inherits from the constructor
5665 template INHERITED; turn FN into a constructor template with a matching
5666 template header. */
5668 tree
5670 {
5671 tree inner_parms
5674 tree parms
5685 }
5687 /* Called when a class template TYPE is redeclared with the indicated
5688 template PARMS, e.g.:
5690 template <class T> struct S;
5691 template <class T> struct S {}; */
5693 bool
5695 {
5696 tree tmpl;
5697 tree tmpl_parms;
5701 {
5704 }
5708 /* The type is nested in some template class. Nothing to worry
5709 about here; there are no new template parameters for the nested
5710 type. */
5714 {
5716 tmpl);
5718 }
5724 {
5734 }
5737 {
5738 tree tmpl_parm;
5739 tree parm;
5740 tree tmpl_default;
5741 tree parm_default;
5755 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5756 TEMPLATE_DECL. */
5766 {
5770 }
5773 {
5774 /* We have in [temp.param]:
5776 A template-parameter may not be given default arguments
5777 by two different declarations in the same scope. */
5782 }
5785 /* Update the previous template parameters (which are the ones
5786 that will really count) with the new default value. */
5789 /* Update the new parameters, too; they'll be used as the
5790 parameters for any members. */
5793 /* Give each template template parm in this redeclaration a
5794 DECL_CONTEXT of the template for which they are a parameter. */
5796 {
5799 }
5803 }
5805 // Cannot redeclare a class template with a different set of constraints.
5807 {
5812 }
5815 }
5817 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5818 to be used when the caller has already checked
5819 (processing_template_decl
5820 && !instantiation_dependent_expression_p (expr)
5821 && potential_constant_expression (expr))
5822 and cleared processing_template_decl. */
5824 tree
5826 {
5829 complain,
5833 }
5835 /* Simplify EXPR if it is a non-dependent expression. Returns the
5836 (possibly simplified) expression. */
5838 tree
5840 {
5844 /* If we're in a template, but EXPR isn't value dependent, simplify
5845 it. We're supposed to treat:
5847 template <typename T> void f(T[1 + 1]);
5848 template <typename T> void f(T[2]);
5850 as two declarations of the same function, for example. */
5853 {
5854 processing_template_decl_sentinel s;
5856 }
5858 }
5860 tree
5862 {
5864 }
5866 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5867 an uninstantiated expression. */
5869 tree
5871 {
5875 {
5878 else
5879 {
5880 processing_template_decl_sentinel s;
5882 }
5883 }
5885 }
5887 /* True iff T is a specialization of a variable template. */
5889 bool
5891 {
5896 }
5898 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5899 template declaration, or a TYPE_DECL for an alias declaration. */
5901 bool
5903 {
5911 }
5913 /* Return TRUE iff T is a specialization of an alias template. */
5915 bool
5917 {
5918 /* It's an alias template specialization if it's an alias and its
5919 TYPE_NAME is a specialization of a primary template. */
5925 }
5927 /* An alias template is complex from a SFINAE perspective if a template-id
5928 using that alias can be ill-formed when the expansion is not, as with
5929 the void_t template. We determine this by checking whether the
5930 expansion for the alias template uses all its template parameters. */
5932 struct uses_all_template_parms_data
5933 {
5936 };
5938 static int
5940 {
5948 }
5950 static bool
5952 {
5967 }
5969 /* Return TRUE iff T is a specialization of a complex alias template with
5970 dependent template-arguments. */
5972 bool
5974 {
5987 }
5989 /* Return the number of innermost template parameters in TMPL. */
5991 static int
5993 {
5996 }
5998 /* Return either TMPL or another template that it is equivalent to under DR
5999 1286: An alias that just changes the name of a template is equivalent to
6000 the other template. */
6002 static tree
6004 {
6007 {
6008 /* Determine if the alias is equivalent to an underlying template. */
6020 tree alias_args = INNERMOST_TEMPLATE_ARGS
6025 /* Alias is equivalent. Strip it and repeat. */
6027 }
6030 }
6032 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6033 must be a reference-to-function or a pointer-to-function type, as specified
6034 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6035 and check that the resulting function has external linkage. */
6037 static tree
6039 tsubst_flags_t complain)
6040 {
6043 linkage_kind linkage;
6058 /* [temp.arg.nontype]/1
6060 A template-argument for a non-type, non-template template-parameter
6061 shall be one of:
6062 [...]
6063 -- the address of an object or function with external [C++11: or
6064 internal] linkage. */
6067 {
6069 {
6075 else
6078 }
6080 }
6084 {
6086 {
6091 else
6095 }
6097 }
6099 accept:
6106 }
6108 /* Subroutine of convert_nontype_argument.
6109 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6110 Emit an error otherwise. */
6112 static bool
6114 tsubst_flags_t complain)
6115 {
6132 {
6137 else
6139 }
6141 }
6143 /* Returns TRUE iff the address of OP is value-dependent.
6145 14.6.2.4 [temp.dep.temp]:
6146 A non-integral non-type template-argument is dependent if its type is
6147 dependent or it has either of the following forms
6148 qualified-id
6149 & qualified-id
6150 and contains a nested-name-specifier which specifies a class-name that
6151 names a dependent type.
6153 We generalize this to just say that the address of a member of a
6154 dependent class is value-dependent; the above doesn't cover the
6155 address of a static data member named with an unqualified-id. */
6157 static bool
6159 {
6160 /* We could use get_inner_reference here, but there's no need;
6161 this is only relevant for template non-type arguments, which
6162 can only be expressed as &id-expression. */
6164 {
6168 }
6171 }
6173 /* The next set of functions are used for providing helpful explanatory
6174 diagnostics for failed overload resolution. Their messages should be
6175 indented by two spaces for consistency with the messages in
6176 call.c */
6178 static int
6180 {
6182 }
6184 /* Other failure functions should call this one, to provide a single function
6185 for setting a breakpoint on. */
6187 static int
6189 {
6191 }
6193 static int
6195 {
6200 }
6202 static int
6204 {
6210 }
6212 static int
6214 {
6218 }
6220 static int
6222 {
6225 " template parameter %qD is not a parameter pack, but "
6229 }
6231 static int
6233 {
6236 " template argument %qE does not match "
6240 }
6242 static int
6244 {
6248 }
6250 static int
6252 {
6258 }
6260 static int
6262 {
6264 {
6269 else
6271 " deduced conflicting values for non-type parameter "
6273 }
6275 }
6277 static int
6279 {
6282 " variable-sized array type %qT is not "
6284 arg);
6286 }
6288 static int
6290 {
6294 arg);
6296 }
6298 static int
6300 {
6302 {
6308 else
6313 }
6315 }
6317 static int
6319 {
6321 }
6323 static int
6326 {
6328 }
6330 static int
6333 {
6339 }
6341 static int
6344 {
6347 {
6355 }
6357 }
6359 static int
6361 {
6364 " template parameters of a template template argument are "
6367 }
6369 static int
6371 {
6377 }
6379 static int
6381 {
6386 }
6388 /* Attempt to convert the non-type template parameter EXPR to the
6389 indicated TYPE. If the conversion is successful, return the
6390 converted value. If the conversion is unsuccessful, return
6391 NULL_TREE if we issued an error message, or error_mark_node if we
6392 did not. We issue error messages for out-and-out bad template
6393 parameters, but not simply because the conversion failed, since we
6394 might be just trying to do argument deduction. Both TYPE and EXPR
6395 must be non-dependent.
6397 The conversion follows the special rules described in
6398 [temp.arg.nontype], and it is much more strict than an implicit
6399 conversion.
6401 This function is called twice for each template argument (see
6402 lookup_template_class for a more accurate description of this
6403 problem). This means that we need to handle expressions which
6404 are not valid in a C++ source, but can be created from the
6405 first call (for instance, casts to perform conversions). These
6406 hacks can go away after we fix the double coercion problem. */
6408 static tree
6410 {
6411 tree expr_type;
6415 /* Detect immediately string literals as invalid non-type argument.
6416 This special-case is not needed for correctness (we would easily
6417 catch this later), but only to provide better diagnostic for this
6418 common user mistake. As suggested by DR 100, we do not mention
6419 linkage issues in the diagnostic as this is not the point. */
6420 /* FIXME we're making this OK. */
6422 {
6428 }
6430 /* Add the ADDR_EXPR now for the benefit of
6431 value_dependent_expression_p. */
6434 {
6438 }
6440 /* If we are in a template, EXPR may be non-dependent, but still
6441 have a syntactic, rather than semantic, form. For example, EXPR
6442 might be a SCOPE_REF, rather than the VAR_DECL to which the
6443 SCOPE_REF refers. Preserving the qualifying scope is necessary
6444 so that access checking can be performed when the template is
6445 instantiated -- but here we need the resolved form so that we can
6446 convert the argument. */
6458 /* If the argument is non-dependent, perform any conversions in
6459 non-dependent context as well. */
6467 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6468 to a non-type argument of "nullptr". */
6472 /* In C++11, integral or enumeration non-type template arguments can be
6473 arbitrary constant expressions. Pointer and pointer to
6474 member arguments can be general constant expressions that evaluate
6475 to a null value, but otherwise still need to be of a specific form. */
6477 {
6479 /* A PTRMEM_CST is already constant, and a valid template
6480 argument for a parameter of pointer to member type, we just want
6481 to leave it in that form rather than lower it to a
6485 {
6486 /* C++17: A template-argument for a non-type template-parameter shall
6487 be a converted constant expression (8.20) of the type of the
6488 template-parameter. */
6494 }
6496 {
6501 }
6502 }
6506 else
6509 /* HACK: Due to double coercion, we can get a
6510 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6511 which is the tree that we built on the first call (see
6512 below when coercing to reference to object or to reference to
6513 function). We just strip everything and get to the arg.
6514 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6515 for examples. */
6517 {
6523 {
6524 /* ??? Maybe we could use convert_from_reference here, but we
6525 would need to relax its constraints because the NOP_EXPR
6526 could actually change the type to something more cv-qualified,
6527 and this is not folded by convert_from_reference. */
6532 && (same_type_ignoring_top_level_qualifiers_p
6535 {
6538 }
6539 }
6540 }
6542 /* [temp.arg.nontype]/5, bullet 1
6544 For a non-type template-parameter of integral or enumeration type,
6545 integral promotions (_conv.prom_) and integral conversions
6546 (_conv.integral_) are applied. */
6548 {
6550 {
6555 }
6560 /* Notice that there are constant expressions like '4 % 0' which
6561 do not fold into integer constants. */
6564 {
6566 {
6570 else
6576 /* else cxx_constant_value complained but gave us
6577 a real constant, so go ahead. */
6579 }
6580 else
6582 }
6584 /* Avoid typedef problems. */
6587 }
6588 /* [temp.arg.nontype]/5, bullet 2
6590 For a non-type template-parameter of type pointer to object,
6591 qualification conversions (_conv.qual_) and the array-to-pointer
6592 conversion (_conv.array_) are applied. */
6594 {
6597 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6598 decay_conversion or an explicit cast. If it's a problematic cast,
6599 we'll complain about it below. */
6601 {
6606 {
6609 }
6610 }
6612 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6614 A template-argument for a non-type, non-template template-parameter
6615 shall be one of: [...]
6617 -- the name of a non-type template-parameter;
6618 -- the address of an object or function with external linkage, [...]
6619 expressed as "& id-expression" where the & is optional if the name
6620 refers to a function or array, or if the corresponding
6621 template-parameter is a reference.
6623 Here, we do not care about functions, as they are invalid anyway
6624 for a parameter of type pointer-to-object. */
6627 /* Non-type template parameters are OK. */
6628 ;
6632 {
6634 {
6637 "because %qD is a variable, not the address of "
6640 }
6642 {
6648 }
6649 /* Other values, like integer constants, might be valid
6650 non-type arguments of some other type. */
6652 }
6653 else
6654 {
6658 {
6663 }
6665 {
6671 }
6674 {
6679 }
6680 /* C++17: For a non-type template-parameter of reference or pointer
6681 type, the value of the constant expression shall not refer to (or
6682 for a pointer type, shall not be the address of):
6683 * a subobject (4.5),
6684 * a temporary object (15.2),
6685 * a string literal (5.13.5),
6686 * the result of a typeid expression (8.2.8), or
6687 * a predefined __func__ variable (11.4.1). */
6689 {
6692 decl);
6694 }
6698 {
6703 }
6705 {
6709 decl);
6711 }
6712 }
6719 }
6720 /* [temp.arg.nontype]/5, bullet 3
6722 For a non-type template-parameter of type reference to object, no
6723 conversions apply. The type referred to by the reference may be more
6724 cv-qualified than the (otherwise identical) type of the
6725 template-argument. The template-parameter is bound directly to the
6726 template-argument, which must be an lvalue. */
6728 {
6730 expr_type))
6734 {
6739 }
6742 {
6747 }
6749 /* [temp.arg.nontype]/1
6751 A template-argument for a non-type, non-template template-parameter
6752 shall be one of: [...]
6754 -- the address of an object or function with external linkage. */
6757 {
6760 {
6763 "because a reference variable does not have a constant "
6766 }
6767 }
6771 /* OK, dependent reference. We don't want to ask whether a DECL is
6773 else
6774 {
6776 {
6782 }
6784 /* DR 1155 allows internal linkage in C++11 and up. */
6787 {
6793 }
6796 }
6800 }
6801 /* [temp.arg.nontype]/5, bullet 4
6803 For a non-type template-parameter of type pointer to function, only
6804 the function-to-pointer conversion (_conv.func_) is applied. If the
6805 template-argument represents a set of overloaded functions (or a
6806 pointer to such), the matching function is selected from the set
6807 (_over.over_). */
6809 {
6810 /* If the argument is a template-id, we might not have enough
6811 context information to decay the pointer. */
6813 {
6817 }
6820 /* Null pointer values are OK in C++11. */
6826 }
6827 /* [temp.arg.nontype]/5, bullet 5
6829 For a non-type template-parameter of type reference to function, no
6830 conversions apply. If the template-argument represents a set of
6831 overloaded functions, the matching function is selected from the set
6832 (_over.over_). */
6834 {
6836 {
6838 {
6843 }
6845 }
6850 }
6851 /* [temp.arg.nontype]/5, bullet 6
6853 For a non-type template-parameter of type pointer to member function,
6854 no conversions apply. If the template-argument represents a set of
6855 overloaded member functions, the matching member function is selected
6856 from the set (_over.over_). */
6858 {
6863 /* [temp.arg.nontype] bullet 1 says the pointer to member
6864 expression must be a pointer-to-member constant. */
6869 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6870 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6873 }
6874 /* [temp.arg.nontype]/5, bullet 7
6876 For a non-type template-parameter of type pointer to data member,
6877 qualification conversions (_conv.qual_) are applied. */
6879 {
6880 /* [temp.arg.nontype] bullet 1 says the pointer to member
6881 expression must be a pointer-to-member constant. */
6889 }
6891 {
6893 {
6898 }
6900 }
6901 /* A template non-type parameter must be one of the above. */
6902 else
6905 /* Sanity check: did we actually convert the argument to the
6906 right type? */
6910 }
6912 /* Subroutine of coerce_template_template_parms, which returns 1 if
6913 PARM_PARM and ARG_PARM match using the rule for the template
6914 parameters of template template parameters. Both PARM and ARG are
6915 template parameters; the rest of the arguments are the same as for
6916 coerce_template_template_parms.
6917 */
6918 static int
6920 tree arg,
6921 tsubst_flags_t complain,
6922 tree in_decl,
6923 tree outer_args)
6924 {
6933 {
6935 /* We encounter instantiations of templates like
6936 template <template <template <class> class> class TT>
6937 class C; */
6938 {
6945 }
6946 /* Fall through. */
6951 /* Argument is a parameter pack but parameter is not. */
6956 /* The tsubst call is used to handle cases such as
6958 template <int> class C {};
6959 template <class T, template <T> class TT> class D {};
6960 D<int, C> d;
6962 i.e. the parameter list of TT depends on earlier parameters. */
6964 {
6969 }
6973 /* Argument is a parameter pack but parameter is not. */
6980 }
6983 }
6985 /* Coerce template argument list ARGLIST for use with template
6986 template-parameter TEMPL. */
6988 static tree
6990 tsubst_flags_t complain)
6991 {
6992 /* Consider an example where a template template parameter declared as
6994 template <class T, class U = std::allocator<T> > class TT
6996 The template parameter level of T and U are one level larger than
6997 of TT. To proper process the default argument of U, say when an
6998 instantiation `TT<int>' is seen, we need to build the full
6999 arguments containing {int} as the innermost level. Outer levels,
7000 available when not appearing as default template argument, can be
7001 obtained from the arguments of the enclosing template.
7003 Suppose that TT is later substituted with std::vector. The above
7004 instantiation is `TT<int, std::allocator<T> >' with TT at
7005 level 1, and T at level 2, while the template arguments at level 1
7006 becomes {std::vector} and the inner level 2 is {int}. */
7010 {
7012 /* We want arguments for the partial specialization, not arguments for
7013 the primary template. */
7015 else
7017 }
7019 {
7020 /* This is an argument of the current template, so we haven't set
7021 DECL_CONTEXT yet. */
7022 tree relevant_template_parms;
7024 /* Parameter levels that are greater than the level of the given
7025 template template parm are irrelevant. */
7032 }
7039 complain,
7042 }
7044 /* A cache of template template parameters with match-all default
7045 arguments. */
7047 static void
7049 {
7053 }
7054 static tree
7056 {
7061 }
7063 /* T is a bound template template-parameter. Copy its arguments into default
7064 arguments of the template template-parameter's template parameters. */
7066 static tree
7068 {
7091 {
7094 {
7097 }
7098 }
7102 }
7104 /* ARG is a bound potential template template-argument, and PARGS is a list
7105 of arguments for the corresponding template template-parameter. Adjust
7106 PARGS as appropriate for application to ARG's template, and if ARG is a
7107 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7108 arguments to the template template parameter. */
7110 static tree
7112 {
7116 {
7117 /* When comparing two template template-parameters in partial ordering,
7118 rewrite the one currently being used as an argument to have default
7119 arguments for all parameters. */
7125 }
7126 else
7127 {
7128 tree aparms
7133 }
7136 }
7138 /* Subroutine of unify for the case when PARM is a
7139 BOUND_TEMPLATE_TEMPLATE_PARM. */
7141 static int
7144 {
7148 /* The template template parm might be variadic and the argument
7149 not, so flatten both argument lists. */
7154 {
7155 /* In keeping with P0522R0, adjust P's template arguments
7156 to apply to A's template; then flatten it again. */
7165 /* If the P0522 adjustment eliminated a pack expansion, deduce
7166 empty packs. */
7172 }
7173 else
7174 {
7175 /* Deduce arguments T, i from TT<T> or TT<i>.
7176 We check each element of PARMVEC and ARGVEC individually
7177 rather than the whole TREE_VEC since they can have
7178 different number of elements, which is allowed under N2555. */
7182 /* Check if the parameters end in a pack, making them
7183 variadic. */
7190 /* If the template argument list of P contains a pack
7191 expansion that is not the last template argument, the
7192 entire template argument list is a non-deduced
7193 context. */
7211 DEDUCE_EXACT,
7214 }
7217 }
7219 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7220 template template parameters. Both PARM_PARMS and ARG_PARMS are
7221 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7222 or PARM_DECL.
7224 Consider the example:
7225 template <class T> class A;
7226 template<template <class U> class TT> class B;
7228 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7229 the parameters to A, and OUTER_ARGS contains A. */
7231 static int
7233 tree arg_parms,
7234 tsubst_flags_t complain,
7235 tree in_decl,
7236 tree outer_args)
7237 {
7249 {
7250 /* P0522R0: A template template-parameter P is at least as specialized as
7251 a template template-argument A if, given the following rewrite to two
7252 function templates, the function template corresponding to P is at
7253 least as specialized as the function template corresponding to A
7254 according to the partial ordering rules for function templates
7255 ([temp.func.order]). Given an invented class template X with the
7256 template parameter list of A (including default arguments):
7258 * Each of the two function templates has the same template parameters,
7259 respectively, as P or A.
7261 * Each function template has a single function parameter whose type is
7262 a specialization of X with template arguments corresponding to the
7263 template parameters from the respective function template where, for
7264 each template parameter PP in the template parameter list of the
7265 function template, a corresponding template argument AA is formed. If
7266 PP declares a parameter pack, then AA is the pack expansion
7267 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7269 If the rewrite produces an invalid type, then P is not at least as
7270 specialized as A. */
7272 /* So coerce P's args to apply to A's parms, and then deduce between A's
7273 args and the converted args. If that succeeds, A is at least as
7274 specialized as P, so they match.*/
7281 {
7287 }
7288 }
7290 /* Determine whether we have a parameter pack at the end of the
7291 template template parameter's template parameter list. */
7293 {
7300 {
7314 }
7315 }
7321 /* Check all of the template parameters except the parameter pack at
7322 the end (if any). */
7324 {
7333 outer_args))
7336 }
7339 {
7340 /* Check each of the template parameters in the template
7341 argument against the template parameter pack at the end of
7342 the template template parameter. */
7349 {
7356 outer_args))
7358 }
7359 }
7362 }
7364 /* Verifies that the deduced template arguments (in TARGS) for the
7365 template template parameters (in TPARMS) represent valid bindings,
7366 by comparing the template parameter list of each template argument
7367 to the template parameter list of its corresponding template
7368 template parameter, in accordance with DR150. This
7369 routine can only be called after all template arguments have been
7370 deduced. It will return TRUE if all of the template template
7371 parameter bindings are okay, FALSE otherwise. */
7372 bool
7374 {
7378 /* We're dealing with template parms in this process. */
7384 {
7389 {
7394 {
7395 /* Look inside the argument pack. */
7398 }
7401 {
7405 /* Extract the next argument from the argument
7406 pack. */
7410 /* Look at the pattern of the pack expansion. */
7413 /* Extract the template parameters from the template
7414 argument. */
7420 /* Verify that we can coerce the template template
7421 parameters from the template argument to the template
7422 parameter. This requires an exact match. */
7424 && !coerce_template_template_parms
7426 targ_parms,
7427 tf_none,
7428 tparm,
7429 targs))
7430 {
7433 }
7434 }
7435 }
7436 }
7438 out:
7442 }
7444 /* Since type attributes aren't mangled, we need to strip them from
7445 template type arguments. */
7447 static tree
7449 {
7459 }
7461 /* And from inside dependent non-type arguments like sizeof(Type). */
7463 static tree
7465 {
7475 }
7477 // A template declaration can be substituted for a constrained
7478 // template template parameter only when the argument is more
7479 // constrained than the parameter.
7480 static bool
7482 {
7485 /* For now, allow constrained template template arguments
7486 and unconstrained template template parameters. */
7492 // If the template parameter is constrained, we need to rewrite its
7493 // constraints in terms of the ARG's template parameters. This ensures
7494 // that all of the template parameter types will have the same depth.
7495 //
7496 // Note that this is only valid when coerce_template_template_parm is
7497 // true for the innermost template parameters of PARM and ARG. In other
7498 // words, because coercion is successful, this conversion will be valid.
7500 {
7507 }
7510 }
7512 // Convert a placeholder argument into a binding to the original
7513 // parameter. The original parameter is saved as the TREE_TYPE of
7514 // ARG.
7517 {
7520 }
7522 /* Convert the indicated template ARG as necessary to match the
7523 indicated template PARM. Returns the converted ARG, or
7524 error_mark_node if the conversion was unsuccessful. Error and
7525 warning messages are issued under control of COMPLAIN. This
7526 conversion is for the Ith parameter in the parameter list. ARGS is
7527 the full set of template arguments deduced so far. */
7529 static tree
7531 tree arg,
7532 tree args,
7533 tsubst_flags_t complain,
7535 tree in_decl)
7536 {
7537 tree orig_arg;
7538 tree val;
7544 /* Trivially convert placeholders. */
7553 {
7554 /* The template argument was the name of some
7555 member function. That's usually
7556 invalid, but static members are OK. In any
7557 case, grab the underlying fields/functions
7558 and issue an error later if required. */
7561 }
7569 /* When determining whether an argument pack expansion is a template,
7570 look at the pattern. */
7574 /* Deal with an injected-class-name used as a template template arg. */
7576 {
7579 {
7589 }
7590 }
7592 is_tmpl_type =
7608 {
7610 {
7614 }
7617 "to refer to a type member of a template parameter, "
7622 typename_type,
7623 complain);
7626 }
7628 {
7630 {
7632 {
7644 else
7647 }
7648 }
7650 }
7652 {
7654 {
7661 else
7664 }
7666 }
7669 /* We already did the appropriate conversion when packing args. */
7672 {
7674 {
7676 /* The number of argument required is not known yet.
7677 Just accept it for now. */
7679 else
7680 {
7682 tree argparm;
7684 /* Strip alias templates that are equivalent to another
7685 template. */
7691 args))
7692 {
7695 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7696 TEMPLATE_DECL. */
7698 {
7703 }
7704 }
7705 else
7706 {
7708 {
7715 }
7718 }
7720 // Check that the constraints are compatible before allowing the
7721 // substitution.
7724 {
7726 {
7732 }
7734 }
7735 }
7736 }
7737 else
7739 /* We only form one instance of each template specialization.
7740 Therefore, if we use a non-canonical variant (i.e., a
7741 typedef), any future messages referring to the type will use
7742 the typedef, which is confusing if those future uses do not
7743 themselves also use the typedef. */
7746 }
7747 else
7748 {
7752 {
7756 }
7757 else
7765 /* We used to call digest_init here. However, digest_init
7766 will report errors, which we don't want when complain
7767 is zero. More importantly, digest_init will try too
7768 hard to convert things: for example, `0' should not be
7769 converted to pointer type at this point according to
7770 the standard. Accepting this is not merely an
7771 extension, since deciding whether or not these
7772 conversions can occur is part of determining which
7773 function template to call, or whether a given explicit
7774 argument specification is valid. */
7776 else
7786 {
7787 /* Reject template arguments that are references to built-in
7788 functions with no library fallbacks. */
7797 }
7800 {
7801 /* Strip typedefs from the SCOPE_REF. */
7804 complain);
7807 }
7808 }
7811 }
7813 /* Coerces the remaining template arguments in INNER_ARGS (from
7814 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7815 Returns the coerced argument pack. PARM_IDX is the position of this
7816 parameter in the template parameter list. ARGS is the original
7817 template argument list. */
7818 static tree
7821 tree args,
7822 tree inner_args,
7824 tree new_args,
7826 tree in_decl,
7827 tsubst_flags_t complain)
7828 {
7831 tree packed_args;
7832 tree argument_pack;
7839 {
7840 /* When the template parameter is a non-type template parameter pack
7841 or template template parameter pack whose type or template
7842 parameters use parameter packs, we know exactly how many arguments
7843 we are looking for. Build a vector of the instantiated decls for
7844 these template parameters in PACKED_PARMS. */
7845 /* We can't use make_pack_expansion here because it would interpret a
7846 _DECL as a use rather than a declaration. */
7860 /* If we're doing a partial instantiation of a member template,
7861 verify that all of the types used for the non-type
7862 template parameter pack are, in fact, valid for non-type
7863 template parameters. */
7866 {
7869 {
7873 }
7874 /* We don't know how many args we have yet, just
7875 use the unconverted ones for now. */
7877 }
7880 }
7881 /* Check if we have a placeholder pack, which indicates we're
7882 in the context of a introduction list. In that case we want
7883 to match this pack to the single placeholder. */
7887 {
7890 }
7891 else
7894 /* Convert the remaining arguments, which will be a part of the
7895 parameter pack "parm". */
7898 {
7904 {
7905 /* Once we've packed as many args as we have types, stop. */
7909 /* We don't know how many args we have yet, just
7910 use the unconverted ones for now. */
7912 else
7914 }
7917 {
7920 }
7921 else
7924 in_decl);
7928 }
7932 {
7937 }
7942 else
7943 {
7946 }
7953 }
7955 /* Returns the number of pack expansions in the template argument vector
7956 ARGS. */
7958 static int
7960 {
7965 {
7969 }
7971 }
7973 /* Convert all template arguments to their appropriate types, and
7974 return a vector containing the innermost resulting template
7975 arguments. If any error occurs, return error_mark_node. Error and
7976 warning messages are issued under control of COMPLAIN.
7978 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7979 for arguments not specified in ARGS. Otherwise, if
7980 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7981 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7982 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7983 ARGS. */
7985 static tree
7987 tree args,
7988 tree in_decl,
7989 tsubst_flags_t complain,
7992 {
7994 tree orig_inner_args;
7995 tree inner_args;
7996 tree new_args;
7997 tree new_inner_args;
8001 /* When used as a boolean value, indicates whether this is a
8002 variadic template parameter list. Since it's an int, we can also
8003 subtract it from nparms to get the number of non-variadic
8004 parameters. */
8009 /* Likewise for parameters with default arguments. */
8017 /* Determine if there are any parameter packs or default arguments. */
8019 {
8027 }
8030 /* If there are no parameters that follow a parameter pack, we need to
8031 expand any argument packs so that we can deduce a parameter pack from
8032 some non-packed args followed by an argument pack, as in variadic85.C.
8033 If there are such parameters, we need to leave argument packs intact
8034 so the arguments are assigned properly. This can happen when dealing
8035 with a nested class inside a partial specialization of a class
8036 template, as in variadic92.C, or when deducing a template parameter pack
8037 from a sub-declarator, as in variadic114.C. */
8041 /* Count any pack expansion args. */
8047 && require_all_args
8048 && !variadic_args_p
8049 && (!use_default_args
8052 {
8054 {
8056 {
8060 }
8061 else
8068 }
8071 }
8072 /* We can't pass a pack expansion to a non-pack parameter of an alias
8073 template (DR 1430). */
8077 && variadic_args_p
8079 {
8081 {
8083 {
8089 {
8092 "pack expansion argument for non-pack parameter "
8094 else
8096 "pack expansion argument for non-pack parameter "
8100 }
8101 }
8103 found:;
8104 }
8106 }
8108 /* We need to evaluate the template arguments, even though this
8109 template-id may be nested within a "sizeof". */
8118 {
8119 tree arg;
8120 tree parm;
8122 /* Get the Ith template parameter. */
8126 {
8129 }
8131 /* Calculate the next argument. */
8134 else
8139 {
8140 /* Some arguments will be placed in the
8141 template parameter pack PARM. */
8148 {
8149 /* We don't know how many args we have yet, just use the
8150 unconverted (and still packed) ones for now. */
8154 }
8158 /* Store this argument. */
8160 {
8161 lost++;
8162 /* We are done with all of the arguments. */
8164 }
8165 else
8166 {
8169 }
8172 }
8174 {
8176 {
8177 /* "If every valid specialization of a variadic template
8178 requires an empty template parameter pack, the template is
8179 ill-formed, no diagnostic required." So check that the
8180 pattern works with this parameter. */
8185 in_decl);
8187 {
8192 }
8194 /* Recover from missing typename. */
8198 /* We don't know how many args we have yet, just
8199 use the unconverted ones for now. */
8203 }
8204 }
8206 {
8207 /* There must be a default arg in this case. */
8210 /* The position of the first default template argument,
8211 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8212 Record that. */
8216 }
8217 else
8221 {
8224 }
8226 /* This only occurs if there was an error in the template
8227 parameter list itself (which we would already have
8228 reported) that we are trying to recover from, e.g., a class
8229 template with a parameter list such as
8230 template<typename..., typename>. */
8232 else
8238 lost++;
8240 }
8245 {
8247 {
8252 }
8254 }
8264 }
8266 /* Convert all template arguments to their appropriate types, and
8267 return a vector containing the innermost resulting template
8268 arguments. If any error occurs, return error_mark_node. Error and
8269 warning messages are not issued.
8271 Note that no function argument deduction is performed, and default
8272 arguments are used to fill in unspecified arguments. */
8273 tree
8275 {
8277 }
8279 /* Convert all template arguments to their appropriate type, and
8280 instantiate default arguments as needed. This returns a vector
8281 containing the innermost resulting template arguments, or
8282 error_mark_node if unsuccessful. */
8283 tree
8285 tsubst_flags_t complain)
8286 {
8288 }
8290 /* Like coerce_template_parms. If PARMS represents all template
8291 parameters levels, this function returns a vector of vectors
8292 representing all the resulting argument levels. Note that in this
8293 case, only the innermost arguments are coerced because the
8294 outermost ones are supposed to have been coerced already.
8296 Otherwise, if PARMS represents only (the innermost) vector of
8297 parameters, this function returns a vector containing just the
8298 innermost resulting arguments. */
8300 static tree
8302 tree args,
8303 tree in_decl,
8304 tsubst_flags_t complain,
8307 {
8310 tree coerced_args;
8313 {
8315 tree level;
8321 {
8322 tree l;
8326 require_all_args,
8327 use_default_args);
8328 else
8335 }
8336 }
8337 else
8340 require_all_args,
8341 use_default_args);
8343 }
8345 /* Returns 1 if template args OT and NT are equivalent. */
8347 int
8349 {
8358 /* For member templates */
8367 {
8384 }
8388 {
8391 /* Don't treat an alias template specialization with dependent
8392 arguments as equivalent to its underlying type when used as a
8393 template argument; we need them to be distinct so that we
8394 substitute into the specialization arguments at instantiation
8395 time. And aliases can't be equivalent without being ==, so
8396 we don't need to look any deeper.
8398 During partial ordering, however, we need to treat them normally so
8399 that we can order uses of the same alias with different
8400 cv-qualification (79960). */
8404 else
8406 }
8409 else
8410 {
8411 /* Try to treat a template non-type argument that has been converted
8412 to the parameter type as equivalent to one that hasn't yet. */
8425 }
8426 }
8428 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8429 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8430 NEWARG_PTR with the offending arguments if they are non-NULL. */
8432 int
8436 {
8449 {
8454 {
8460 }
8461 }
8463 }
8467 {
8469 }
8471 static void
8473 {
8483 /* We are called both from instantiate_decl, where we've already had a
8484 tinst_level pushed, and instantiate_template, where we haven't.
8485 Compensate. */
8496 else
8505 }
8508 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8509 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8510 documentation for TEMPLATE_ID_EXPR. */
8512 tree
8514 {
8515 tree type;
8523 {
8526 }
8529 {
8531 unknown_type_node,
8533 arglist);
8535 }
8542 }
8544 /* Within the scope of a template class S<T>, the name S gets bound
8545 (in build_self_reference) to a TYPE_DECL for the class, not a
8546 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8547 or one of its enclosing classes, and that type is a template,
8548 return the associated TEMPLATE_DECL. Otherwise, the original
8549 DECL is returned.
8551 Also handle the case when DECL is a TREE_LIST of ambiguous
8552 injected-class-names from different bases. */
8554 tree
8556 {
8560 /* DR 176: A lookup that finds an injected-class-name (10.2
8561 [class.member.lookup]) can result in an ambiguity in certain cases
8562 (for example, if it is found in more than one base class). If all of
8563 the injected-class-names that are found refer to specializations of
8564 the same class template, and if the name is followed by a
8565 template-argument-list, the reference refers to the class template
8566 itself and not a specialization thereof, and is not ambiguous. */
8568 {
8571 {
8577 }
8580 else
8582 }
8588 }
8590 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8591 parameters, find the desired type.
8593 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8595 IN_DECL, if non-NULL, is the template declaration we are trying to
8596 instantiate.
8598 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8599 the class we are looking up.
8601 Issue error and warning messages under control of COMPLAIN.
8603 If the template class is really a local class in a template
8604 function, then the FUNCTION_CONTEXT is the function in which it is
8605 being instantiated.
8607 ??? Note that this function is currently called *twice* for each
8608 template-id: the first time from the parser, while creating the
8609 incomplete type (finish_template_type), and the second type during the
8610 real instantiation (instantiate_template_class). This is surely something
8611 that we want to avoid. It also causes some problems with argument
8612 coercion (see convert_nontype_argument for more information on this). */
8614 static tree
8617 {
8619 tree t;
8622 spec_entry elt;
8623 hashval_t hash;
8626 {
8630 else
8631 {
8638 }
8641 }
8643 {
8646 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8647 an implicit typename for the second A. Deal with it. */
8652 {
8655 }
8656 }
8659 {
8662 }
8664 {
8668 }
8670 {
8673 }
8675 /* Issue an error message if we didn't find a template. */
8677 {
8681 }
8684 /* Make sure it's a user visible template, if it was named by
8685 the user. */
8688 {
8690 {
8694 }
8696 }
8700 /* An alias that just changes the name of a template is equivalent to the
8701 other template, so if any of the arguments are pack expansions, strip
8702 the alias to avoid problems with a pack expansion passed to a non-pack
8703 alias template parameter (DR 1430). */
8708 {
8709 tree parm;
8718 }
8719 else
8720 {
8722 tree gen_tmpl;
8723 tree type_decl;
8731 /* An error occurred while building the template TEMPL, and a
8732 diagnostic has most certainly been emitted for that
8733 already. Let's propagate that error. */
8742 {
8743 /* We've been given an incomplete set of template arguments.
8744 For example, given:
8746 template <class T> struct S1 {
8747 template <class U> struct S2 {};
8748 template <class U> struct S2<U*> {};
8749 };
8751 we will be called with an ARGLIST of `U*', but the
8752 TEMPLATE will be `template <class T> template
8753 <class U> struct S1<T>::S2'. We must fill in the missing
8754 arguments. */
8758 }
8760 /* Now we should have enough arguments. */
8763 /* From here on, we're only interested in the most general
8764 template. */
8766 /* Calculate the BOUND_ARGS. These will be the args that are
8767 actually tsubst'd into the definition to create the
8768 instantiation. */
8770 complain,
8775 /* We were unable to bind the arguments. */
8778 /* In the scope of a template class, explicit references to the
8779 template class refer to the type of the template, not any
8780 instantiation of it. For example, in:
8782 template <class T> class C { void f(C<T>); }
8784 the `C<T>' is just the same as `C'. Outside of the
8785 class, however, such a reference is an instantiation. */
8789 {
8794 }
8796 /* If we already have this specialization, return it. */
8806 /* If the the template's constraints are not satisfied,
8807 then we cannot form a valid type.
8809 Note that the check is deferred until after the hash
8810 lookup. This prevents redundant checks on previously
8811 instantiated specializations. */
8813 {
8815 {
8818 }
8820 }
8824 /* If the deduced arguments are invalid, then the binding
8825 failed. */
8829 complain))
8836 {
8841 }
8851 /* Create the type. */
8853 {
8854 /* The user referred to a specialization of an alias
8855 template represented by GEN_TMPL.
8857 [temp.alias]/2 says:
8859 When a template-id refers to the specialization of an
8860 alias template, it is equivalent to the associated
8861 type obtained by substitution of its
8862 template-arguments for the template-parameters in the
8863 type-id of the alias template. */
8866 /* Note that the call above (by indirectly calling
8867 register_specialization in tsubst_decl) registers the
8868 TYPE_DECL representing the specialization of the alias
8869 template. So next time someone substitutes ARGLIST for
8870 the template parms into the alias template (GEN_TMPL),
8871 she'll get that TYPE_DECL back. */
8875 }
8877 {
8879 {
8890 }
8891 else
8892 {
8893 /* We don't want to call start_enum for this type, since
8894 the values for the enumeration constants may involve
8895 template parameters. And, no one should be interested
8896 in the enumeration constants for such a type. */
8899 }
8903 }
8905 {
8911 /* A local class. Make sure the decl gets registered properly. */
8916 /* This instantiation is another name for the primary
8917 template type. Set the TYPE_CANONICAL field
8918 appropriately. */
8921 /* Some of the template arguments require structural
8922 equality testing, so this template class requires
8923 structural equality testing. */
8925 }
8926 else
8929 /* If we called start_enum or pushtag above, this information
8930 will already be set up. */
8932 {
8939 }
8940 else
8944 {
8950 {
8953 }
8954 }
8958 {
8962 {
8963 tree attributes
8971 }
8972 }
8974 /* Let's consider the explicit specialization of a member
8975 of a class template specialization that is implicitly instantiated,
8976 e.g.:
8977 template<class T>
8978 struct S
8979 {
8980 template<class U> struct M {}; //#0
8981 };
8983 template<>
8984 template<>
8985 struct S<int>::M<char> //#1
8986 {
8987 int i;
8988 };
8989 [temp.expl.spec]/4 says this is valid.
8991 In this case, when we write:
8992 S<int>::M<char> m;
8994 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8995 the one of #0.
8997 When we encounter #1, we want to store the partial instantiation
8998 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9000 For all cases other than this "explicit specialization of member of a
9001 class template", we just want to store the most general template into
9002 the CLASSTYPE_TI_TEMPLATE of M.
9004 This case of "explicit specialization of member of a class template"
9005 only happens when:
9006 1/ the enclosing class is an instantiation of, and therefore not
9007 the same as, the context of the most general template, and
9008 2/ we aren't looking at the partial instantiation itself, i.e.
9009 the innermost arguments are not the same as the innermost parms of
9010 the most general template.
9012 So it's only when 1/ and 2/ happens that we want to use the partial
9013 instantiation of the member template in lieu of its most general
9014 template. */
9018 /* the enclosing class must be an instantiation... */
9021 {
9025 tree partial_inst_args =
9032 use_partial_inst_tmpl =
9033 /*...and we must not be looking at the partial instantiation
9034 itself. */
9036 partial_inst_args);
9037 }
9040 /* This case is easy; there are no member templates involved. */
9042 else
9043 {
9044 /* This is a full instantiation of a member template. Find
9045 the partial instantiation of which this is an instance. */
9047 /* Temporarily reduce by one the number of levels in the ARGLIST
9048 so as to avoid comparing the last set of arguments. */
9052 /* FOUND is either a proper class type, or an alias
9053 template specialization. In the later case, it's a
9054 TYPE_DECL, resulting from the substituting of arguments
9055 for parameters in the TYPE_DECL of the alias template
9056 done earlier. So be careful while getting the template
9057 of FOUND. */
9059 ? found
9063 }
9065 // Build template info for the new specialization.
9074 /* Note this use of the partial instantiation so we can check it
9075 later in maybe_process_partial_specialization. */
9082 /* Now that the type has been registered on the instantiations
9083 list, we set up the enumerators. Because the enumeration
9084 constants may involve the enumeration type itself, we make
9085 sure to register the type first, and then create the
9086 constants. That way, doing tsubst_expr for the enumeration
9087 constants won't result in recursive calls here; we'll find
9088 the instantiation and exit above. */
9092 /* If the type makes use of template parameters, the
9093 code that generates debugging information will crash. */
9096 /* Possibly limit visibility based on template args. */
9103 }
9104 }
9106 /* Wrapper for lookup_template_class_1. */
9108 tree
9111 {
9112 tree ret;
9118 }
9120 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9122 tree
9124 {
9125 /* The type of the expression is NULL_TREE since the template-id could refer
9126 to an explicit or partial specialization. */
9129 /* Except that concepts are always bool. */
9132 }
9134 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9136 tree
9138 {
9142 /* We never want to return a VAR_DECL for a variable concept, since they
9143 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9158 {
9160 {
9163 }
9165 }
9167 /* If a template-id refers to a specialization of a variable
9168 concept, then the expression is true if and only if the
9169 concept's constraints are satisfied by the given template
9170 arguments.
9172 NOTE: This is an extension of Concepts Lite TS that
9173 allows constraints to be used in expressions. */
9175 {
9178 }
9181 }
9183 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9184 TARGS template args, and instantiate it if it's not dependent. */
9186 tree
9188 tsubst_flags_t complain)
9189 {
9192 {
9195 }
9198 }
9200 \f
9201 struct pair_fn_data
9202 {
9203 tree_fn_t fn;
9204 tree_fn_t any_fn;
9206 /* True when we should also visit template parameters that occur in
9207 non-deduced contexts. */
9210 };
9212 /* Called from for_each_template_parm via walk_tree. */
9214 static tree
9216 {
9223 #define WALK_SUBTREE(NODE) \
9224 do \
9225 { \
9226 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9227 pfd->include_nondeduced_p, \
9228 pfd->any_fn); \
9229 if (result) goto out; \
9230 } \
9231 while (0)
9241 {
9245 /* Fall through. */
9251 else
9261 /* Since we're not going to walk subtrees, we have to do this
9262 explicitly here. */
9264 /* Fall through. */
9267 /* Check the return type. */
9270 /* Check the parameter types. Since default arguments are not
9271 instantiated until they are needed, the TYPE_ARG_TYPES may
9272 contain expressions that involve template parameters. But,
9273 no-one should be looking at them yet. And, once they're
9274 instantiated, they don't contain template parameters, so
9275 there's no point in looking at them then, either. */
9276 {
9277 tree parm;
9282 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9283 want walk_tree walking into them itself. */
9285 }
9288 {
9292 }
9309 /* Fall through. */
9321 /* Record template parameters such as `T' inside `TT<T>'. */
9323 /* Fall through. */
9335 /* A template template parameter is encountered. */
9339 /* Already substituted template template parameter */
9344 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9345 partial instantiation. */
9357 /* If there's no type, then this thing must be some expression
9358 involving template parameters. */
9380 }
9382 #undef WALK_SUBTREE
9384 /* We didn't find any template parameters we liked. */
9385 out:
9387 }
9389 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9390 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9391 call FN with the parameter and the DATA.
9392 If FN returns nonzero, the iteration is terminated, and
9393 for_each_template_parm returns 1. Otherwise, the iteration
9394 continues. If FN never returns a nonzero value, the value
9395 returned by for_each_template_parm is 0. If FN is NULL, it is
9396 considered to be the function which always returns 1.
9398 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9399 parameters that occur in non-deduced contexts. When false, only
9400 visits those template parameters that can be deduced. */
9402 static tree
9406 tree_fn_t any_fn)
9407 {
9409 tree result;
9411 /* Set up. */
9417 /* Walk the tree. (Conceptually, we would like to walk without
9418 duplicates, but for_each_template_parm_r recursively calls
9419 for_each_template_parm, so we would need to reorganize a fair
9420 bit to use walk_tree_without_duplicates, so we keep our own
9421 visited list.) */
9424 else
9427 for_each_template_parm_r,
9431 /* Clean up. */
9433 {
9436 }
9439 }
9441 /* Returns true if T depends on any template parameter. */
9443 int
9445 {
9475 else
9476 {
9479 }
9484 }
9486 /* Returns true iff current_function_decl is an incompletely instantiated
9487 template. Useful instead of processing_template_decl because the latter
9488 is set to 0 during instantiate_non_dependent_expr. */
9490 bool
9492 {
9501 }
9503 /* Returns true iff we are currently within a template other than a
9504 default-capturing generic lambda, so we don't need to worry about semantic
9505 processing. */
9507 bool
9509 {
9511 }
9513 /* Returns true if T depends on any template parameter with level LEVEL. */
9515 bool
9517 {
9520 }
9522 /* Returns true if the signature of DECL depends on any template parameter from
9523 its enclosing class. */
9525 bool
9527 {
9537 template_parm_outer_level,
9547 }
9549 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9550 ill-formed translation unit, i.e. a variable or function that isn't
9551 usable in a constant expression. */
9555 {
9560 }
9562 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9563 neglectable and instantiated from within an erroneous instantiation. */
9565 static bool
9567 {
9578 }
9586 /* We're starting to instantiate D; record the template instantiation context
9587 for diagnostics and to restore it later. */
9589 bool
9591 {
9593 }
9595 /* We're starting to instantiate D; record the template instantiation context
9596 at LOC for diagnostics and to restore it later. */
9598 bool
9600 {
9604 {
9605 /* Tell error.c not to try to instantiate any templates. */
9608 "template instantiation depth exceeds maximum of %d"
9610 max_tinst_depth);
9612 }
9614 /* If the current instantiation caused problems, don't let it instantiate
9615 anything else. Do allow deduction substitution and decls usable in
9616 constant expressions. */
9620 /* When not -quiet, dump template instantiations other than functions, since
9621 announce_function will take care of those. */
9640 }
9642 /* We're done instantiating this template; return to the instantiation
9643 context. */
9645 void
9647 {
9648 /* Restore the filename and line number stashed away when we started
9649 this instantiation. */
9653 }
9655 /* We're instantiating a deferred template; restore the template
9656 instantiation context in which the instantiation was requested, which
9657 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9659 static tree
9661 {
9673 }
9675 /* Returns the TINST_LEVEL which gives the original instantiation
9676 context. */
9680 {
9686 }
9688 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9689 vector of template arguments, as for tsubst.
9691 Returns an appropriate tsubst'd friend declaration. */
9693 static tree
9695 {
9696 tree new_friend;
9701 /* This was a friend declared with an explicit template
9702 argument list, e.g.:
9704 friend void f<>(T);
9706 to indicate that f was a template instantiation, not a new
9707 function declaration. Now, we have to figure out what
9708 instantiation of what template. */
9709 {
9711 tree new_args;
9712 tree tmpl;
9715 /* Friend functions are looked up in the containing namespace scope.
9716 We must enter that scope, to avoid finding member functions of the
9717 current class with same name. */
9732 tsk_none);
9734 }
9738 /* The NEW_FRIEND will look like an instantiation, to the
9739 compiler, but is not an instantiation from the point of view of
9740 the language. For example, we might have had:
9742 template <class T> struct S {
9743 template <class U> friend void f(T, U);
9744 };
9746 Then, in S<int>, template <class U> void f(int, U) is not an
9747 instantiation of anything. */
9753 {
9757 }
9759 /* The mangled name for the NEW_FRIEND is incorrect. The function
9760 is not a template instantiation and should not be mangled like
9761 one. Therefore, we forget the mangling here; we'll recompute it
9762 later if we need it. */
9764 {
9767 }
9770 {
9771 tree old_decl;
9772 tree new_friend_template_info;
9773 tree new_friend_result_template_info;
9774 tree ns;
9777 /* We must save some information from NEW_FRIEND before calling
9778 duplicate decls since that function will free NEW_FRIEND if
9779 possible. */
9781 new_friend_is_defn =
9786 {
9787 /* This declaration is a `primary' template. */
9790 new_friend_result_template_info
9792 }
9793 else
9796 /* Inside pushdecl_namespace_level, we will push into the
9797 current namespace. However, the friend function should go
9798 into the namespace of the template. */
9808 {
9809 /* This new friend declaration matched an existing
9810 declaration. For example, given:
9812 template <class T> void f(T);
9813 template <class U> class C {
9814 template <class T> friend void f(T) {}
9815 };
9817 the friend declaration actually provides the definition
9818 of `f', once C has been instantiated for some type. So,
9819 old_decl will be the out-of-class template declaration,
9820 while new_friend is the in-class definition.
9822 But, if `f' was called before this point, the
9823 instantiation of `f' will have DECL_TI_ARGS corresponding
9824 to `T' but not to `U', references to which might appear
9825 in the definition of `f'. Previously, the most general
9826 template for an instantiation of `f' was the out-of-class
9827 version; now it is the in-class version. Therefore, we
9828 run through all specialization of `f', adding to their
9829 DECL_TI_ARGS appropriately. In particular, they need a
9830 new set of outer arguments, corresponding to the
9831 arguments for this class instantiation.
9833 The same situation can arise with something like this:
9835 friend void f(int);
9836 template <class T> class C {
9837 friend void f(T) {}
9838 };
9840 when `C<int>' is instantiated. Now, `f(int)' is defined
9841 in the class. */
9844 /* On the other hand, if the in-class declaration does
9845 *not* provide a definition, then we don't want to alter
9846 existing definitions. We can just leave everything
9847 alone. */
9848 ;
9849 else
9850 {
9854 /* Overwrite whatever template info was there before, if
9855 any, with the new template information pertaining to
9856 the declaration. */
9860 {
9861 /* We should have called reregister_specialization in
9862 duplicate_decls. */
9867 /* Instantiate it if the global has already been used. */
9871 }
9872 else
9873 {
9874 tree t;
9876 /* Indicate that the old function template is a partial
9877 instantiation. */
9885 /* Reassign any specializations already in the hash table
9886 to the new more general template, and add the
9887 additional template args. */
9891 {
9893 spec_entry elt;
9905 register_specialization
9908 }
9910 }
9911 }
9913 /* The information from NEW_FRIEND has been merged into OLD_DECL
9914 by duplicate_decls. */
9916 }
9917 }
9918 else
9919 {
9923 /* In the code
9924 template <class T> class C {
9925 template <class U> friend void C1<U>::f (); // case 1
9926 friend void C2<T>::f (); // case 2
9927 };
9928 we only need to make sure CONTEXT is a complete type for
9929 case 2. To distinguish between the two cases, we note that
9930 CONTEXT of case 1 remains dependent type after tsubst while
9931 this isn't true for case 2. */
9941 {
9943 /* do_friend adds the TEMPLATE_DECL for any member friend
9944 template even if it isn't a member template, i.e.
9945 template <class T> friend A<T>::f();
9946 Look through it in that case. */
9950 /* Check to see that the declaration is really present, and,
9951 possibly obtain an improved declaration. */
9956 }
9957 }
9960 }
9962 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9963 template arguments, as for tsubst.
9965 Returns an appropriate tsubst'd friend type or error_mark_node on
9966 failure. */
9968 static tree
9970 {
9971 tree friend_type;
9972 tree tmpl;
9973 tree context;
9976 {
9979 }
9984 {
9987 else
9989 }
9991 /* Look for a class template declaration. We look for hidden names
9992 because two friend declarations of the same template are the
9993 same. For example, in:
9995 struct A {
9996 template <typename> friend class F;
9997 };
9998 template <typename> struct B {
9999 template <typename> friend class F;
10000 };
10002 both F templates are the same. */
10006 /* But, if we don't find one, it might be because we're in a
10007 situation like this:
10009 template <class T>
10010 struct S {
10011 template <class U>
10012 friend struct S;
10013 };
10015 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
10016 for `S<int>', not the TEMPLATE_DECL. */
10018 {
10021 }
10024 {
10025 /* The friend template has already been declared. Just
10026 check to see that the declarations match, and install any new
10027 default parameters. We must tsubst the default parameters,
10028 of course. We only need the innermost template parameters
10029 because that is all that redeclare_class_template will look
10030 at. */
10033 {
10034 tree parms;
10035 location_t saved_input_location;
10045 }
10048 }
10049 else
10050 {
10051 /* The friend template has not already been declared. In this
10052 case, the instantiation of the template class will cause the
10053 injection of this template into the global scope. */
10058 /* The new TMPL is not an instantiation of anything, so we
10059 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10060 the new type because that is supposed to be the corresponding
10061 template decl, i.e., TMPL. */
10068 /* Inject this template into the global scope. */
10070 }
10073 {
10076 else
10078 }
10081 }
10083 /* Returns zero if TYPE cannot be completed later due to circularity.
10084 Otherwise returns one. */
10086 static int
10088 {
10098 else
10100 }
10105 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10106 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10108 static tree
10111 {
10120 {
10127 clauses
10131 else
10133 }
10134 /* If the first attribute argument is an identifier, don't
10135 pass it through tsubst. Attributes like mode, format,
10136 cleanup and several target specific attributes expect it
10137 unmodified. */
10139 {
10140 tree chain
10145 }
10147 {
10148 /* An attribute pack expansion. */
10157 {
10161 }
10163 }
10164 else
10171 }
10173 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10174 unchanged or a new TREE_LIST chain. */
10176 static tree
10179 {
10184 {
10188 }
10192 {
10195 {
10198 {
10200 do
10205 }
10206 }
10208 }
10211 }
10213 /* Apply any attributes which had to be deferred until instantiation
10214 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10215 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10217 static void
10220 {
10222 tree t;
10229 {
10233 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10234 to our attributes parameter. */
10236 }
10237 else
10238 {
10240 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10241 lookup_template_class_1, and should be preserved. */
10245 }
10249 {
10253 }
10257 {
10262 {
10265 {
10269 do
10272 }
10273 else
10275 }
10278 }
10279 }
10281 /* Perform (or defer) access check for typedefs that were referenced
10282 from within the template TMPL code.
10283 This is a subroutine of instantiate_decl and instantiate_class_template.
10284 TMPL is the template to consider and TARGS is the list of arguments of
10285 that template. */
10287 static void
10289 {
10290 location_t saved_location;
10301 {
10313 /* Make access check error messages point to the location
10314 of the use of the typedef. */
10318 tf_warning_or_error);
10319 }
10321 }
10323 static tree
10325 {
10327 tree typedecl;
10328 tree pbinfo;
10329 tree base_list;
10331 tree fn_context;
10340 /* Figure out which template is being instantiated. */
10344 /* Determine what specialization of the original template to
10345 instantiate. */
10348 {
10351 }
10353 {
10354 /* This TYPE is actually an instantiation of a partial
10355 specialization. We replace the innermost set of ARGS with
10356 the arguments appropriate for substitution. For example,
10357 given:
10359 template <class T> struct S {};
10360 template <class T> struct S<T*> {};
10362 and supposing that we are instantiating S<int*>, ARGS will
10363 presently be {int*} -- but we need {int}. */
10366 }
10367 else
10368 {
10371 }
10373 /* If the template we're instantiating is incomplete, then clearly
10374 there's nothing we can do. */
10378 /* If we've recursively instantiated too many templates, stop. */
10382 /* Now we're really doing the instantiation. Mark the type as in
10383 the process of being defined. */
10386 /* We may be in the middle of deferred access check. Disable
10387 it now. */
10394 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10399 else
10400 {
10403 }
10404 /* Use #pragma pack from the template context. */
10410 /* Set the input location to the most specialized template definition.
10411 This is needed if tsubsting causes an error. */
10423 {
10426 /* Adjust visibility for template arguments. */
10428 }
10434 /* We should never instantiate a nested class before its enclosing
10435 class; we need to look up the nested class by name before we can
10436 instantiate it, and that lookup should instantiate the enclosing
10437 class. */
10443 {
10444 tree pbase_binfo;
10445 tree pushed_scope;
10448 /* We must enter the scope containing the type, as that is where
10449 the accessibility of types named in dependent bases are
10450 looked up from. */
10453 /* Substitute into each of the bases to determine the actual
10454 basetypes. */
10456 {
10457 tree base;
10463 {
10464 expanded_bases =
10471 }
10474 {
10476 /* Extract the already-expanded base class. */
10478 else
10479 /* Substitute to figure out the base class. */
10481 NULL_TREE);
10489 }
10490 }
10492 /* The list is now in reverse order; correct that. */
10497 }
10498 /* Now call xref_basetypes to set up all the base-class
10499 information. */
10507 /* Now that our base classes are set up, enter the scope of the
10508 class, so that name lookups into base classes, etc. will work
10509 correctly. This is precisely analogous to what we do in
10510 begin_class_definition when defining an ordinary non-template
10511 class, except we also need to push the enclosing classes. */
10514 /* Now members are processed in the order of declaration. */
10517 {
10521 {
10523 {
10524 /* Build new CLASSTYPE_NESTED_UTDS. */
10526 tree newtag;
10532 /* If the member is a class template, then -- even after
10533 substitution -- there may be dependent types in the
10534 template argument list for the class. We increment
10535 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10536 that function will assume that no types are dependent
10537 when outside of a template. */
10547 {
10551 /* Unfortunately, lookup_template_class sets
10552 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10553 instantiation (i.e., for the type of a member
10554 template class nested within a template class.)
10555 This behavior is required for
10556 maybe_process_partial_specialization to work
10557 correctly, but is not accurate in this case;
10558 the TAG is not an instantiation of anything.
10559 (The corresponding TEMPLATE_DECL is an
10560 instantiation, but the TYPE is not.) */
10563 /* Now, we call pushtag to put this NEWTAG into the scope of
10564 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10565 pushtag calling push_template_decl. We don't have to do
10566 this for enums because it will already have been done in
10567 tsubst_enum. */
10571 }
10572 }
10574 {
10575 tree r;
10584 /* Instantiate members marked with attribute used. */
10590 }
10593 /* A closure type for a lambda in a default argument for a
10594 member template. Ignore it; it will be instantiated with
10596 else
10597 {
10598 /* Build new TYPE_FIELDS. */
10600 {
10601 tree condition;
10604 condition =
10614 }
10616 {
10617 tree r;
10621 /* The file and line for this declaration, to
10622 assist in error message reporting. Since we
10623 called push_tinst_level above, we don't need to
10624 restore these. */
10634 {
10635 /* A capture pack became multiple fields. */
10638 }
10641 {
10645 {
10646 /* In [temp.inst]:
10648 [t]he initialization (and any associated
10649 side-effects) of a static data member does
10650 not occur unless the static data member is
10651 itself used in a way that requires the
10652 definition of the static data member to
10653 exist.
10655 Therefore, we do not substitute into the
10656 initialized for the static data member here. */
10657 finish_static_data_member_decl
10663 /* Instantiate members marked with attribute used. */
10666 }
10668 {
10669 /* Determine whether R has a valid type and can be
10670 completed later. If R is invalid, then its type
10671 is replaced by error_mark_node. */
10677 {
10678 /* If R's type couldn't be completed and
10679 it isn't a flexible array member (whose
10680 type is incomplete by definition) give
10681 an error. */
10684 }
10685 }
10687 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10688 such a thing will already have been added to the field
10689 list by tsubst_enum in finish_member_declaration in the
10690 CLASSTYPE_NESTED_UTDS case above. */
10694 {
10697 }
10698 }
10699 }
10700 }
10701 }
10702 else
10703 {
10706 {
10707 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10713 {
10714 /* template <class T> friend class C; */
10717 }
10719 {
10720 /* template <class T> friend class C::D; */
10726 }
10729 {
10730 /* This could be either
10732 friend class T::C;
10734 when dependent_type_p is false or
10736 template <class U> friend class T::C;
10738 otherwise. */
10739 /* Bump processing_template_decl in case this is something like
10740 template <class T> friend struct A<T>::B. */
10747 }
10751 {
10752 /* friend class C;
10754 where C hasn't been declared yet. Let's lookup name
10755 from namespace scope directly, bypassing any name that
10756 come from dependent base class. */
10759 /* The call to xref_tag_from_type does injection for friend
10760 classes. */
10762 friend_type =
10766 }
10768 /* friend class C<T>; */
10771 /* Otherwise it's
10773 friend class C;
10775 where C is already declared or
10777 friend class C<int>;
10779 We don't have to do anything in these cases. */
10782 /* Trick make_friend_class into realizing that the friend
10783 we're adding is a template, not an ordinary class. It's
10784 important that we use make_friend_class since it will
10785 perform some error-checking and output cross-reference
10786 information. */
10794 }
10795 else
10796 {
10797 /* Build new DECL_FRIENDLIST. */
10798 tree r;
10800 /* The file and line for this declaration, to
10801 assist in error message reporting. Since we
10802 called push_tinst_level above, we don't need to
10803 restore these. */
10807 {
10810 }
10815 {
10818 }
10819 }
10820 }
10821 }
10824 {
10825 /* Restore these before substituting into the lambda capture
10826 initializers. */
10829 }
10832 {
10835 {
10841 {
10842 /* Set function_depth to avoid garbage collection. */
10846 }
10848 /* We need to instantiate the capture list from the template
10849 after we've instantiated the closure members, but before we
10850 consider adding the conversion op. Also keep any captures
10851 that may have been added during instantiation of the op(). */
10853 tree tmpl_cap
10862 }
10863 else
10865 }
10867 /* Set the file and line number information to whatever is given for
10868 the class itself. This puts error messages involving generated
10869 implicit functions at a predictable point, and the same point
10870 that would be used for non-template classes. */
10877 /* We don't instantiate default arguments for member functions. 14.7.1:
10879 The implicit instantiation of a class template specialization causes
10880 the implicit instantiation of the declarations, but not of the
10881 definitions or default arguments, of the class member functions,
10882 member classes, static data members and member templates.... */
10884 /* Some typedefs referenced from within the template code need to be access
10885 checked at template instantiation time, i.e now. These types were
10886 added to the template at parsing time. Let's get those and perform
10887 the access checks then. */
10897 /* The vtable for a template class can be emitted in any translation
10898 unit in which the class is instantiated. When there is no key
10899 method, however, finish_struct_1 will already have added TYPE to
10900 the keyed_classes. */
10905 }
10907 /* Wrapper for instantiate_class_template_1. */
10909 tree
10911 {
10912 tree ret;
10917 }
10919 static tree
10921 {
10922 tree r;
10928 else
10929 {
10936 }
10938 }
10940 /* Given a function parameter pack TMPL_PARM and some function parameters
10941 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10942 and set *SPEC_P to point at the next point in the list. */
10944 tree
10946 {
10947 /* Collect all of the extra "packed" parameters into an
10948 argument pack. */
10949 tree parmvec;
10959 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10965 /* Build the argument packs. */
10970 }
10972 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10973 NONTYPE_ARGUMENT_PACK. */
10975 static tree
10977 {
10979 }
10981 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10982 pack expansion with no extra args, 2 if it has extra args, or 0
10983 if it is not a pack expansion. */
10985 static int
10987 {
10993 /* A decl pack is itself an expansion. */
11000 }
11003 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11005 static tree
11007 {
11014 }
11016 /* This is a subroutine of tsubst_pack_expansion.
11018 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11019 mechanism to store the (non complete list of) arguments of the
11020 substitution and return a non substituted pack expansion, in order
11021 to wait for when we have enough arguments to really perform the
11022 substitution. */
11024 static bool
11028 {
11029 /* If one pack has an expansion and another pack has a normal
11030 argument or if one pack has an empty argument and an another
11031 one hasn't then tsubst_pack_expansion cannot perform the
11032 substitution and need to fall back on the
11033 PACK_EXPANSION_EXTRA mechanism. */
11041 {
11044 parm_pack;
11046 {
11051 /* We can't substitute a pack expansion with extra args into
11052 our pattern. */
11056 else
11058 }
11062 }
11064 }
11066 /* [temp.variadic]/6 says that:
11068 The instantiation of a pack expansion [...]
11069 produces a list E1,E2, ..., En, where N is the number of elements
11070 in the pack expansion parameters.
11072 This subroutine of tsubst_pack_expansion produces one of these Ei.
11074 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11075 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11076 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11077 INDEX is the index 'i' of the element Ei to produce. ARGS,
11078 COMPLAIN, and IN_DECL are the same parameters as for the
11079 tsubst_pack_expansion function.
11081 The function returns the resulting Ei upon successful completion,
11082 or error_mark_node.
11084 Note that this function possibly modifies the ARGS parameter, so
11085 it's the responsibility of the caller to restore it. */
11087 static tree
11089 tree parm_packs,
11091 tree args /* This parm gets
11093 tsubst_flags_t complain,
11094 tree in_decl)
11095 {
11096 tree t;
11099 /* For each parameter pack, change the substitution of the parameter
11100 pack to the ith argument in its argument pack, then expand the
11101 pattern. */
11103 {
11108 ith_elem_is_expansion |=
11111 /* Select the Ith argument from the pack. */
11114 {
11116 {
11121 }
11122 else
11124 }
11125 else
11126 {
11131 {
11133 /* Update the corresponding argument. */
11135 }
11136 else
11137 /* Re-use the ARGUMENT_PACK_SELECT. */
11139 }
11141 }
11143 /* Substitute into the PATTERN with the (possibly altered)
11144 arguments. */
11146 /* Expanding a fixed parameter pack from
11147 coerce_template_parameter_pack. */
11152 {
11155 else
11158 }
11162 else
11165 /* If the Ith argument pack element is a pack expansion, then
11166 the Ith element resulting from the substituting is going to
11167 be a pack expansion as well. */
11172 }
11174 /* When the unexpanded parameter pack in a fold expression expands to an empty
11175 sequence, the value of the expression is as follows; the program is
11176 ill-formed if the operator is not listed in this table.
11178 && true
11179 || false
11180 , void() */
11182 tree
11184 {
11188 {
11197 }
11203 }
11205 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11206 form an expression that combines the two terms using the
11207 operator of T. */
11209 static tree
11211 {
11215 // Handle compound assignment operators.
11220 {
11230 complain);
11231 }
11232 }
11234 /* Substitute ARGS into the pack of a fold expression T. */
11238 {
11240 }
11242 /* Substitute ARGS into the pack of a fold expression T. */
11246 {
11248 }
11250 /* Expand a PACK of arguments into a grouped as left fold.
11251 Given a pack containing elements A0, A1, ..., An and an
11252 operator @, this builds the expression:
11254 ((A0 @ A1) @ A2) ... @ An
11256 Note that PACK must not be empty.
11258 The operator is defined by the original fold expression T. */
11260 static tree
11262 {
11265 {
11268 }
11270 }
11272 /* Substitute into a unary left fold expression. */
11274 static tree
11276 tree in_decl)
11277 {
11282 {
11286 }
11289 else
11291 }
11293 /* Substitute into a binary left fold expression.
11295 Do ths by building a single (non-empty) vector of argumnts and
11296 building the expression from those elements. */
11298 static tree
11300 tree in_decl)
11301 {
11310 {
11315 }
11323 }
11325 /* Expand a PACK of arguments into a grouped as right fold.
11326 Given a pack containing elementns A0, A1, ..., and an
11327 operator @, this builds the expression:
11329 A0@ ... (An-2 @ (An-1 @ An))
11331 Note that PACK must not be empty.
11333 The operator is defined by the original fold expression T. */
11335 tree
11337 {
11338 // Build the expression.
11342 {
11345 }
11347 }
11349 /* Substitute into a unary right fold expression. */
11351 static tree
11353 tree in_decl)
11354 {
11359 {
11363 }
11366 else
11368 }
11370 /* Substitute into a binary right fold expression.
11372 Do ths by building a single (non-empty) vector of arguments and
11373 building the expression from those elements. */
11375 static tree
11377 tree in_decl)
11378 {
11387 {
11392 }
11401 }
11404 /* Substitute ARGS into T, which is an pack expansion
11405 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11406 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11407 (if only a partial substitution could be performed) or
11408 ERROR_MARK_NODE if there was an error. */
11409 tree
11411 tree in_decl)
11412 {
11413 tree pattern;
11417 tree result;
11425 /* Add in any args remembered from an earlier partial instantiation. */
11430 /* Determine the argument packs that will instantiate the parameter
11431 packs used in the expansion expression. While we're at it,
11432 compute the number of arguments to be expanded and make sure it
11433 is consistent. */
11436 {
11443 {
11448 else
11451 }
11453 {
11454 /* ??? Support use in other patterns. */
11458 }
11460 {
11461 /* We know we have correct local_specializations if this
11462 expansion is at function scope, or if we're dealing with a
11463 local parameter in a requires expression; for the latter,
11464 tsubst_requires_expr set it up appropriately. */
11467 else
11468 /* We can't rely on local_specializations for a parameter
11469 name used later in a function declaration (such as in a
11470 late-specified return type). Even if it exists, it might
11471 have the wrong value for a recursive call. */
11475 {
11476 /* This parameter pack was used in an unevaluated context. Just
11477 make a dummy decl, since it's only used for its type. */
11480 /* Partial instantiation of the parm_pack, we can't build
11481 up an argument pack yet. */
11483 else
11485 }
11486 }
11489 else
11490 {
11496 }
11503 /* This can only happen if we forget to expand an argument
11504 pack somewhere else. Just return an error, silently. */
11505 {
11509 }
11512 {
11516 /* Don't bother trying to do a partial substitution with
11517 incomplete packs; we'll try again after deduction. */
11524 {
11529 pattern);
11530 else
11532 pattern);
11534 }
11536 /* Keep track of the parameter packs and their corresponding
11537 argument packs. */
11540 }
11541 else
11542 {
11543 /* We can't substitute for this parameter pack. We use a flag as
11544 well as the missing_level counter because function parameter
11545 packs don't have a level. */
11548 }
11549 }
11551 /* If the expansion is just T..., return the matching argument pack, unless
11552 we need to call convert_from_reference on all the elements. This is an
11553 important optimization; see c++/68422. */
11556 {
11558 /* Types need no adjustment, nor does sizeof..., and if we still have
11559 some pack expansion args we won't do anything yet. */
11564 /* Also optimize expression pack expansions if we can tell that the
11565 elements won't have reference type. */
11571 /* Otherwise use the normal path so we get convert_from_reference. */
11572 }
11574 /* We cannot expand this expansion expression, because we don't have
11575 all of the argument packs we need. */
11577 {
11578 /* We got some full packs, but we can't substitute them in until we
11579 have values for all the packs. So remember these until then. */
11584 }
11586 {
11587 /* There were no real arguments, we're just replacing a parameter
11588 pack with another version of itself. Substitute into the
11589 pattern and return a PACK_EXPANSION_*. The caller will need to
11590 deal with that. */
11594 else
11598 }
11603 {
11604 /* We're in a late-specified return type, so create our own local
11605 specializations map; the current map is either NULL or (in the
11606 case of recursive unification) might have bindings that we don't
11607 want to use or alter. */
11610 }
11612 /* For each argument in each argument pack, substitute into the
11613 pattern. */
11617 {
11619 i,
11621 in_decl);
11624 {
11627 }
11628 }
11630 /* Update ARGS to restore the substitution from parameter packs to
11631 their argument packs. */
11633 {
11639 else
11640 {
11648 /* Update the corresponding argument. */
11652 else
11654 }
11655 }
11658 {
11661 }
11663 /* If the dependent pack arguments were such that we end up with only a
11664 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11670 }
11672 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11673 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11674 parameter packs; all parms generated from a function parameter pack will
11675 have the same DECL_PARM_INDEX. */
11677 tree
11679 {
11681 tree patparm;
11684 {
11690 }
11691 else
11692 {
11697 }
11700 }
11702 /* Make an argument pack out of the TREE_VEC VEC. */
11704 static tree
11706 {
11707 tree pack;
11711 else
11712 {
11715 }
11718 }
11720 /* Return an exact copy of template args T that can be modified
11721 independently. */
11723 static tree
11725 {
11733 {
11738 }
11744 }
11746 /* Substitute ARGS into the vector or list of template arguments T. */
11748 static tree
11750 {
11762 {
11764 tree new_arg;
11769 {
11770 /* Substitute into an expansion expression. */
11774 /* Add to the expanded length adjustment the number of
11775 expanded arguments. We subtract one from this
11776 measurement, because the argument pack expression
11777 itself is already counted as 1 in
11778 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11779 the argument pack is empty. */
11781 }
11783 {
11784 /* Substitute into each of the arguments. */
11793 else
11798 }
11799 else
11808 }
11813 /* Make space for the expanded arguments coming from template
11814 argument packs. */
11816 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11817 arguments for a member template.
11818 In that case each TREE_VEC in ORIG_T represents a level of template
11819 arguments, and ORIG_T won't carry any non defaulted argument count.
11820 It will rather be the nested TREE_VECs that will carry one.
11821 In other words, ORIG_T carries a non defaulted argument count only
11822 if it doesn't contain any nested TREE_VEC. */
11824 {
11828 }
11830 {
11834 {
11837 /* Now expand the template argument pack "in place". */
11840 }
11841 else
11842 {
11844 out++;
11845 }
11846 }
11849 }
11851 /* Substitute ARGS into one level PARMS of template parameters. */
11853 static tree
11855 {
11862 {
11870 }
11873 }
11875 /* Return the result of substituting ARGS into the template parameters
11876 given by PARMS. If there are m levels of ARGS and m + n levels of
11877 PARMS, then the result will contain n levels of PARMS. For
11878 example, if PARMS is `template <class T> template <class U>
11879 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11880 result will be `template <int*, double, class V>'. */
11882 static tree
11884 {
11888 /* When substituting into a template, we must set
11889 PROCESSING_TEMPLATE_DECL as the template parameters may be
11890 dependent if they are based on one-another, and the dependency
11891 predicates are short-circuit outside of templates. */
11898 {
11905 }
11910 }
11912 /* Return the result of substituting ARGS into one template parameter
11913 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11914 parameter and which TREE_PURPOSE is the default argument of the
11915 template parameter. */
11917 static tree
11919 {
11940 }
11942 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11943 type T. If T is not an aggregate or enumeration type, it is
11944 handled as if by tsubst. IN_DECL is as for tsubst. If
11945 ENTERING_SCOPE is nonzero, T is the context for a template which
11946 we are presently tsubst'ing. Return the substituted value. */
11948 static tree
11950 tree args,
11951 tsubst_flags_t complain,
11952 tree in_decl,
11954 {
11959 {
11964 /* Fall through. */
11968 {
11969 tree argvec;
11970 tree context;
11971 tree r;
11975 /* In "sizeof(X<I>)" we need to evaluate "I". */
11981 /* First, determine the context for the type we are looking
11982 up. */
11985 {
11988 /* If context is a nested class inside a class template,
11989 it may still need to be instantiated (c++/33959). */
11991 }
11993 /* Then, figure out what arguments are appropriate for the
11994 type we are trying to find. For example, given:
11996 template <class T> struct S;
11997 template <class T, class U> void f(T, U) { S<U> su; }
11999 and supposing that we are instantiating f<int, double>,
12000 then our ARGS will be {int, double}, but, when looking up
12001 S we only want {double}. */
12006 else
12007 {
12011 }
12017 }
12018 else
12019 /* This is not a template type, so there's nothing to do. */
12024 }
12025 }
12029 /* Substitute into the default argument ARG (a default argument for
12030 FN), which has the indicated TYPE. */
12032 tree
12034 tsubst_flags_t complain)
12035 {
12040 /* This can happen in invalid code. */
12055 /* This default argument came from a template. Instantiate the
12056 default argument here, not in tsubst. In the case of
12057 something like:
12059 template <class T>
12060 struct S {
12061 static T t();
12062 void f(T = t());
12063 };
12065 we must be careful to do name lookup in the scope of S<T>,
12066 rather than in the current class. */
12068 /* The "this" pointer is not valid in a default argument. */
12070 {
12075 }
12080 /* The default argument expression may cause implicitly defined
12081 member functions to be synthesized, which will result in garbage
12082 collection. We must treat this situation as if we were within
12083 the body of function so as to avoid collecting live data on the
12084 stack. */
12094 /* Restore the "this" pointer. */
12096 {
12099 }
12106 /* Make sure the default argument is reasonable. */
12112 {
12116 }
12119 }
12121 /* Substitute into all the default arguments for FN. */
12123 static void
12125 {
12126 tree arg;
12127 tree tmpl_args;
12131 /* If this function is not yet instantiated, we certainly don't need
12132 its default arguments. */
12135 /* Don't do this again for clones. */
12141 arg;
12147 complain);
12148 }
12150 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12152 static tree
12154 tree lambda_fntype)
12155 {
12160 /* Nobody should be tsubst'ing into non-template functions. */
12164 {
12165 /* If T is not dependent, just return it. */
12169 /* Calculate the most general template of which R is a
12170 specialization, and the complete set of arguments used to
12171 specialize R. */
12174 (DECL_TEMPLATE_RESULT
12180 /* Check to see if we already have this specialization. */
12182 {
12186 }
12188 /* We can see more levels of arguments than parameters if
12189 there was a specialization of a member template, like
12190 this:
12192 template <class T> struct S { template <class U> void f(); }
12193 template <> template <class U> void S<int>::f(U);
12195 Here, we'll be substituting into the specialization,
12196 because that's where we can find the code we actually
12197 want to generate, but we'll have enough arguments for
12198 the most general template.
12200 We also deal with the peculiar case:
12202 template <class T> struct S {
12203 template <class U> friend void f();
12204 };
12205 template <class U> void f() {}
12206 template S<int>;
12207 template void f<double>();
12209 Here, the ARGS for the instantiation of will be {int,
12210 double}. But, we only need as many ARGS as there are
12211 levels of template parameters in CODE_PATTERN. We are
12212 careful not to get fooled into reducing the ARGS in
12213 situations like:
12215 template <class T> struct S { template <class U> void f(U); }
12216 template <class T> template <> void S<T>::f(int) {}
12218 which we can spot because the pattern will be a
12219 specialization in this case. */
12226 }
12227 else
12228 {
12229 /* This special case arises when we have something like this:
12231 template <class T> struct S {
12232 friend void f<int>(int, double);
12233 };
12235 Here, the DECL_TI_TEMPLATE for the friend declaration
12236 will be an IDENTIFIER_NODE. We are being called from
12237 tsubst_friend_function, and we want only to create a
12238 new decl (R) with appropriate types so that we can call
12239 determine_specialization. */
12242 }
12259 /* If we hit excessive deduction depth, the type is bogus even if
12260 it isn't error_mark_node, so don't build a decl. */
12264 /* We do NOT check for matching decls pushed separately at this
12265 point, as they may not represent instantiations of this
12266 template, and in any case are considered separate under the
12267 discrete model. */
12271 /* Clear out the mangled name and RTL for the instantiation. */
12274 /* Leave DECL_INITIAL set on deleted instantiations. */
12279 /* OpenMP UDRs have the only argument a reference to the declared
12280 type. We want to diagnose if the declared type is a reference,
12281 which is invalid, but as references to references are usually
12282 quietly merged, diagnose it here. */
12284 {
12285 tree argtype
12290 "reference type %qT in "
12294 argtype);
12295 }
12298 /* Type-conversion operator. Reconstruct the name, in
12299 case it's the name of one of the template's parameters. */
12309 {
12313 }
12320 /* If this is an instantiation of a function with internal
12321 linkage, we already know what object file linkage will be
12322 assigned to the instantiation. */
12331 /* We'll re-clone as appropriate in instantiate_template. */
12334 /* If we aren't complaining now, return on error before we register
12335 the specialization so that we'll complain eventually. */
12341 /* When instantiating a constrained member, substitute
12342 into the constraints to create a new constraint. */
12345 {
12348 }
12350 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12351 this in the special friend case mentioned above where
12352 GEN_TMPL is NULL. */
12354 {
12359 tree new_r
12362 /* We instantiated this while substituting into
12363 the type earlier (template/friend54.C). */
12366 /* We're not supposed to instantiate default arguments
12367 until they are called, for a template. But, for a
12368 declaration like:
12370 template <class T> void f ()
12371 { extern void g(int i = T()); }
12373 we should do the substitution when the template is
12374 instantiated. We handle the member function case in
12375 instantiate_class_template since the default arguments
12376 might refer to other members of the class. */
12381 }
12382 else
12385 /* Copy the list of befriending classes. */
12389 {
12393 }
12396 {
12400 /* If this is an instantiation of a member template, clone it.
12401 If it isn't, that'll be handled by
12402 clone_constructors_and_destructors. */
12405 }
12416 /* Possibly limit visibility based on template args. */
12419 {
12423 }
12432 }
12434 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12436 static tree
12438 tree lambda_fntype)
12439 {
12440 /* We can get here when processing a member function template,
12441 member class template, or template template parameter. */
12444 tree spec;
12445 tree tmpl_args;
12446 tree full_args;
12447 tree r;
12451 {
12452 /* Template template parameter is treated here. */
12456 /* If we get a real template back, return it. This can happen in
12457 the context of most_specialized_partial_spec. */
12460 else
12461 /* The new TEMPLATE_DECL was built in
12462 reduce_template_parm_level. */
12465 }
12468 {
12469 /* We might already have an instance of this template.
12470 The ARGS are for the surrounding class type, so the
12471 full args contain the tsubst'd args for the context,
12472 plus the innermost args from the template decl. */
12476 /* Because this is a template, the arguments will still be
12477 dependent, even after substitution. If
12478 PROCESSING_TEMPLATE_DECL is not set, the dependency
12479 predicates will short-circuit. */
12487 /* If this is a default template template argument,
12488 tsubst might not have changed anything. */
12496 }
12498 /* Make a new template decl. It will be similar to the
12499 original, but will record the current template arguments.
12500 We also create a new function declaration, which is just
12501 like the old one, but points to this new template, rather
12502 than the old one. */
12507 // Build new template info linking to the original template decl.
12509 {
12512 }
12513 else
12516 /* The template parameters for this new template are all the
12517 template parameters for the old template, except the
12518 outermost level of parameters. */
12521 complain);
12525 {
12526 tree new_type;
12534 /* For a partial specialization, we need to keep pointing to
12535 the primary template. */
12541 }
12542 else
12543 {
12544 tree new_decl;
12548 else
12558 {
12561 }
12562 else
12563 {
12566 }
12567 }
12577 /* Record this non-type partial instantiation. */
12583 }
12585 /* True if FN is the op() for a lambda in an uninstantiated template. */
12587 bool
12589 {
12594 }
12596 /* True if FN is the op() for a lambda regenerated from a lambda in an
12597 uninstantiated template. */
12599 bool
12601 {
12604 }
12606 /* We're instantiating a variable from template function TCTX. Return the
12607 corresponding current enclosing scope. This gets complicated because lambda
12608 functions in templates are regenerated rather than instantiated, but generic
12609 lambda functions are subsequently instantiated. */
12611 static tree
12613 {
12621 {
12632 {
12636 }
12638 }
12640 }
12642 /* Substitute the ARGS into the T, which is a _DECL. Return the
12643 result of the substitution. Issue error and warning messages under
12644 control of COMPLAIN. */
12646 static tree
12648 {
12649 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12650 location_t saved_loc;
12655 /* Set the filename and linenumber to improve error-reporting. */
12660 {
12670 {
12678 {
12679 /* If there is a local specialization that isn't a
12680 parameter pack, it means that we're doing a "simple"
12681 substitution from inside tsubst_pack_expansion. Just
12682 return the local specialization (which will be a single
12683 parm). */
12690 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12691 the parameters in this function parameter pack. */
12695 {
12698 /* Zero-length parameter packs are boring. Just substitute
12699 into the chain. */
12703 }
12704 else
12705 {
12706 /* All we did was update the type. Make a note of that. */
12709 }
12710 }
12712 /* Loop through all of the parameters we'll build. When T is
12713 a function parameter pack, LEN is the number of expanded
12714 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12717 {
12724 /* We're on the Ith parameter of the function parameter
12725 pack. */
12726 {
12727 /* Get the Ith type. */
12730 /* Rename the parameter to include the index. */
12733 }
12735 /* We're dealing with a normal parameter. */
12743 {
12746 else
12749 }
12759 /* Keep track of the first new parameter we
12760 generate. That's what will be returned to the
12761 caller. */
12765 /* Build a proper chain of parameters when substituting
12766 into a function parameter pack. */
12769 }
12771 /* If cp_unevaluated_operand is set, we're just looking for a
12772 single dummy parameter, so don't keep going. */
12777 /* FIRST_R contains the start of the chain we've built. */
12779 }
12783 {
12790 {
12791 /* This field is a lambda capture pack. Return a TREE_VEC of
12792 the expanded fields to instantiate_class_template_1 and
12793 store them in the specializations hash table as a
12794 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12798 {
12801 }
12802 else
12803 {
12804 /* All we did was update the type. Make a note of that. */
12807 }
12808 }
12811 {
12814 {
12818 }
12828 /* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
12829 number of bits. */
12835 {
12836 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12837 NSDMI in perform_member_init. Still set DECL_INITIAL
12838 so that we know there is one. */
12843 }
12844 /* We don't have to set DECL_CONTEXT here; it is set by
12845 finish_member_declaration. */
12853 }
12856 {
12861 }
12862 }
12866 /* We reach here only for member using decls. We also need to check
12867 uses_template_parms because DECL_DEPENDENT_P is not set for a
12868 using-declaration that designates a member of the current
12869 instantiation (c++/53549). */
12872 {
12876 {
12881 {
12885 {
12888 }
12889 else
12890 {
12893 }
12895 }
12896 }
12897 else
12898 {
12904 else
12905 {
12908 }
12909 }
12910 }
12911 else
12912 {
12915 }
12920 {
12923 tree spec;
12925 tree ctx;
12934 {
12935 /* If this is the canonical decl, we don't have to
12936 mess with instantiations, and often we can't (for
12937 typename, template type parms and such). Note that
12938 TYPE_NAME is not correct for the above test if
12939 we've copied the type for a typedef. */
12945 }
12947 /* Check to see if we already have the specialization we
12948 need. */
12951 {
12952 /* T is a static data member or namespace-scope entity.
12953 We have to substitute into namespace-scope variables
12954 (not just variable templates) because of cases like:
12956 template <class T> void f() { extern T t; }
12958 where the entity referenced is not known until
12959 instantiation time. */
12963 {
12965 complain,
12967 /* If CTX is unchanged, then T is in fact the
12968 specialization we want. That situation occurs when
12969 referencing a static data member within in its own
12970 class. We can use pointer equality, rather than
12971 same_type_p, because DECL_CONTEXT is always
12972 canonical... */
12974 /* ... unless T is a member template; in which
12975 case our caller can be willing to create a
12976 specialization of that template represented
12977 by T. */
12981 }
12984 {
12989 argvec = (coerce_innermost_template_parms
12997 }
12998 }
12999 else
13000 {
13001 /* A local variable. */
13003 /* Subsequent calls to pushdecl will fill this in. */
13005 /* Unless this is a reference to a static variable from an
13006 enclosing function, in which case we need to fill it in now. */
13008 {
13012 }
13014 }
13015 /* If we already have the specialization we need, there is
13016 nothing more to do. */
13018 {
13021 }
13023 /* Create a new node for the specialization we need. */
13026 {
13029 else
13037 {
13038 /* Mask off any template args past the variable's context so we
13039 don't replace the auto with an unrelated argument. */
13043 /* This should never happen with the new lambda instantiation
13044 model, but keep the handling just in case. */
13047 }
13049 }
13051 {
13052 /* Even if the original location is out of scope, the
13053 newly substituted one is not. */
13060 {
13061 /* It may seem that this case cannot occur, since:
13063 typedef void f();
13064 void g() { f x; }
13066 declares a function, not a variable. However:
13068 typedef void f();
13069 template <typename T> void g() { T t; }
13070 template void g<f>();
13072 is an attempt to declare a variable with function
13073 type. */
13075 /* R is not yet sufficiently initialized, so we
13076 just use its name. */
13079 }
13081 /* Wait until cp_finish_decl to set this again, to handle
13082 circular dependency (template/instantiate6.C). */
13087 {
13092 {
13095 }
13097 }
13101 }
13107 /* Clear out the mangled name and RTL for the instantiation. */
13111 /* The initializer must not be expanded until it is required;
13112 see [temp.inst]. */
13116 {
13119 /* Possibly limit visibility based on template args. */
13122 {
13126 }
13128 }
13131 {
13132 /* A static data member declaration is always marked
13133 external when it is declared in-class, even if an
13134 initializer is present. We mimic the non-template
13135 processing here. */
13143 }
13144 else
13145 {
13150 }
13158 /* Preserve a typedef that names a type. */
13160 {
13164 /* An alias template specialization can be dependent
13165 even if its underlying type is not. */
13167 }
13170 }
13175 }
13176 #undef RETURN
13178 out:
13179 /* Restore the file and line information. */
13183 }
13185 /* Substitute into the ARG_TYPES of a function type.
13186 If END is a TREE_CHAIN, leave it and any following types
13187 un-substituted. */
13189 static tree
13191 tree args,
13192 tree end,
13193 tsubst_flags_t complain,
13194 tree in_decl)
13195 {
13196 tree remaining_arg_types;
13200 tree default_arg;
13211 {
13212 /* For a pack expansion, perform substitution on the
13213 entire expression. Later on, we'll handle the arguments
13214 one-by-one. */
13219 /* So that we'll spin through the parameters, one by one. */
13221 else
13222 {
13223 /* We only partially substituted into the parameter
13224 pack. Our type is TYPE_PACK_EXPANSION. */
13227 }
13228 }
13241 {
13243 {
13247 }
13249 }
13250 /* DR 657. */
13254 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13255 top-level qualifiers as required. */
13258 /* We do not substitute into default arguments here. The standard
13259 mandates that they be instantiated only when needed, which is
13260 done in build_over_call. */
13263 /* Except that we do substitute default arguments under tsubst_lambda_expr,
13264 since the new op() won't have any associated template arguments for us
13265 to refer to later. */
13271 {
13272 /* We've instantiated a template before its default arguments
13273 have been parsed. This can happen for a nested template
13274 class, and is not an error unless we require the default
13275 argument in a call of this function. */
13276 remaining_arg_types =
13279 }
13280 else
13281 remaining_arg_types =
13283 }
13286 }
13288 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13289 *not* handle the exception-specification for FNTYPE, because the
13290 initial substitution of explicitly provided template parameters
13291 during argument deduction forbids substitution into the
13292 exception-specification:
13294 [temp.deduct]
13296 All references in the function type of the function template to the
13297 corresponding template parameters are replaced by the specified tem-
13298 plate argument values. If a substitution in a template parameter or
13299 in the function type of the function template results in an invalid
13300 type, type deduction fails. [Note: The equivalent substitution in
13301 exception specifications is done only when the function is instanti-
13302 ated, at which point a program is ill-formed if the substitution
13303 results in an invalid type.] */
13305 static tree
13307 tree args,
13308 tsubst_flags_t complain,
13309 tree in_decl)
13310 {
13311 tree return_type;
13313 tree fntype;
13315 /* The TYPE_CONTEXT is not used for function/method types. */
13318 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13319 failure. */
13323 {
13324 /* Substitute the argument types. */
13336 {
13337 /* DR 1207: 'this' is in scope in the trailing return type. */
13339 }
13341 /* Substitute the return type. */
13345 {
13348 }
13349 }
13350 else
13351 /* Substitute the return type. */
13356 /* DR 486 clarifies that creation of a function type with an
13357 invalid return type is a deduction failure. */
13360 {
13362 {
13365 else
13367 }
13369 }
13370 /* And DR 657. */
13375 {
13376 /* Substitute the argument types. */
13381 }
13383 /* Construct a new type node and return it. */
13385 {
13390 }
13391 else
13392 {
13394 /* Don't pick up extra function qualifiers from the basetype. */
13397 {
13398 /* [temp.deduct]
13400 Type deduction may fail for any of the following
13401 reasons:
13403 -- Attempting to create "pointer to member of T" when T
13404 is not a class type. */
13407 r);
13409 }
13414 }
13421 }
13423 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13424 ARGS into that specification, and return the substituted
13425 specification. If there is no specification, return NULL_TREE. */
13427 static tree
13429 tree args,
13430 tsubst_flags_t complain,
13431 tree in_decl,
13433 {
13434 tree specs;
13435 tree new_specs;
13440 {
13441 /* A noexcept-specifier. */
13446 {
13447 /* Defer instantiation of noexcept-specifiers to avoid
13448 excessive instantiations (c++/49107). */
13451 {
13452 /* We already partially instantiated this member template,
13453 so combine the new args with the old. */
13458 }
13459 else
13460 {
13463 }
13464 }
13465 else
13466 new_specs = tsubst_copy_and_build
13470 }
13472 {
13475 else
13477 {
13478 tree spec;
13483 {
13484 /* Expand the pack expansion type. */
13487 in_decl);
13493 else
13494 {
13495 /* We're substituting into a member template, so
13496 we got a TYPE_PACK_EXPANSION back. Add that
13497 expansion and move on. */
13501 expanded_specs,
13502 complain);
13505 }
13506 }
13509 {
13512 else
13517 complain);
13518 }
13521 }
13522 }
13524 }
13526 /* Take the tree structure T and replace template parameters used
13527 therein with the argument vector ARGS. IN_DECL is an associated
13528 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13529 Issue error and warning messages under control of COMPLAIN. Note
13530 that we must be relatively non-tolerant of extensions here, in
13531 order to preserve conformance; if we allow substitutions that
13532 should not be allowed, we may allow argument deductions that should
13533 not succeed, and therefore report ambiguous overload situations
13534 where there are none. In theory, we could allow the substitution,
13535 but indicate that it should have failed, and allow our caller to
13536 make sure that the right thing happens, but we don't try to do this
13537 yet.
13539 This function is used for dealing with types, decls and the like;
13540 for expressions, use tsubst_expr or tsubst_copy. */
13542 tree
13544 {
13567 else
13572 /* Reuse typedefs. We need to do this to handle dependent attributes,
13573 such as attribute aligned. */
13576 {
13580 {
13581 /* DECL represents an alias template and we want to
13582 instantiate it. */
13586 }
13590 {
13594 }
13599 else
13600 /* The typedef is from a non-template context. */
13604 {
13606 r = cp_build_qualified_type_real
13610 }
13611 else
13612 {
13613 /* We don't have an instantiation yet, so drop the typedef. */
13618 }
13619 }
13636 {
13662 {
13668 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13669 needed. */
13675 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13676 with TREE_SIDE_EFFECTS that indicates this is not an integral
13677 constant expression. */
13680 {
13683 }
13686 }
13692 {
13698 /* Early in template argument deduction substitution, we don't
13699 want to reduce the level of 'auto', or it will be confused
13700 with a normal template parm in subsequent deduction. */
13712 {
13716 {
13717 /* See through ARGUMENT_PACK_SELECT arguments. */
13719 /* If the selected argument is an expansion E, that most
13720 likely means we were called from
13721 gen_elem_of_pack_expansion_instantiation during the
13722 substituting of pack an argument pack (which Ith
13723 element is a pack expansion, where I is
13724 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13725 In this case, the Ith element resulting from this
13726 substituting is going to be a pack expansion, which
13727 pattern is the pattern of E. Let's return the
13728 pattern of E, and
13729 gen_elem_of_pack_expansion_instantiation will
13730 build the resulting pack expansion from it. */
13732 {
13733 /* Make sure we aren't throwing away arg info. */
13736 }
13737 }
13738 }
13743 {
13745 /* If ARG is an argument pack, we don't actually want to
13746 perform a substitution here, because substitutions
13747 for argument packs are only done
13748 element-by-element. We can get to this point when
13749 substituting the type of a non-type template
13750 parameter pack, when that type actually contains
13751 template parameter packs from an outer template, e.g.,
13753 template<typename... Types> struct A {
13754 template<Types... Values> struct B { };
13755 }; */
13759 {
13765 return cp_build_qualified_type_real
13767 }
13769 {
13770 /* We are processing a type constructed from a
13771 template template parameter. */
13782 /* Consider this code:
13784 template <template <class> class Template>
13785 struct Internal {
13786 template <class Arg> using Bind = Template<Arg>;
13787 };
13789 template <template <class> class Template, class Arg>
13790 using Instantiate = Template<Arg>; //#0
13792 template <template <class> class Template,
13793 class Argument>
13794 using Bind =
13795 Instantiate<Internal<Template>::template Bind,
13796 Argument>; //#1
13798 When #1 is parsed, the
13799 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13800 parameter `Template' in #0 matches the
13801 UNBOUND_CLASS_TEMPLATE representing the argument
13802 `Internal<Template>::template Bind'; We then want
13803 to assemble the type `Bind<Argument>' that can't
13804 be fully created right now, because
13805 `Internal<Template>' not being complete, the Bind
13806 template cannot be looked up in that context. So
13807 we need to "store" `Bind<Argument>' for later
13808 when the context of Bind becomes complete. Let's
13809 store that in a TYPENAME_TYPE. */
13813 argvec),
13814 typename_type,
13815 complain);
13817 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13818 are resolving nested-types in the signature of a
13819 member function templates. Otherwise ARG is a
13820 TEMPLATE_DECL and is the real template to be
13821 instantiated. */
13829 complain);
13830 return cp_build_qualified_type_real
13832 }
13835 else
13836 /* TEMPLATE_PARM_INDEX. */
13838 }
13841 /* This can happen during the attempted tsubst'ing in
13842 unify. This means that we don't yet have any information
13843 about the template parameter in question. */
13846 /* If we get here, we must have been looking at a parm for a
13847 more deeply nested template. Make a new version of this
13848 template parameter, but with a lower level. */
13850 {
13855 {
13857 r = cp_build_qualified_type_real
13861 }
13868 /* Break infinite recursion when substituting the constraints
13870 else
13871 {
13882 {
13883 /* Propagate constraints on placeholders. */
13888 {
13892 }
13893 }
13896 /* We have reduced the level of the template
13897 template parameter, but not the levels of its
13898 template parameters, so canonical_type_parameter
13899 will not be able to find the canonical template
13900 template parameter for this level. Thus, we
13901 require structural equality checking to compare
13902 TEMPLATE_TEMPLATE_PARMs. */
13906 else
13910 {
13912 /* We might need to substitute into the types of non-type
13913 template parameters. */
13925 }
13926 }
13930 /* OK, now substitute the type of the non-type parameter. We
13931 couldn't do it earlier because it might be an auto parameter,
13932 and we wouldn't need to if we had an argument. */
13941 }
13944 }
13947 {
13955 {
13959 }
13962 {
13966 }
13969 {
13973 }
13979 }
13982 /* We should never be tsubsting a binfo. */
13986 /* A vector of template arguments. */
13992 {
13996 /* [temp.deduct]
13998 Type deduction may fail for any of the following
13999 reasons:
14001 -- Attempting to create a pointer to reference type.
14002 -- Attempting to create a reference to a reference type or
14003 a reference to void.
14005 Core issue 106 says that creating a reference to a reference
14006 during instantiation is no longer a cause for failure. We
14007 only enforce this check in strict C++98 mode. */
14011 {
14014 /* We keep track of the last time we issued this error
14015 message to avoid spewing a ton of messages during a
14016 single bad template instantiation. */
14019 {
14024 else
14027 }
14030 }
14034 {
14036 {
14039 type);
14040 else
14042 type);
14043 }
14045 }
14047 {
14051 }
14053 /* In C++0x, during template argument substitution, when there is an
14054 attempt to create a reference to a reference type, reference
14055 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14057 "If a template-argument for a template-parameter T names a type
14058 that is a reference to a type A, an attempt to create the type
14059 'lvalue reference to cv T' creates the type 'lvalue reference to
14060 A,' while an attempt to create the type type rvalue reference to
14061 cv T' creates the type T"
14062 */
14063 r = cp_build_reference_type
14066 else
14071 /* Will this ever be needed for TYPE_..._TO values? */
14075 }
14077 {
14080 {
14081 /* [temp.deduct]
14083 Type deduction may fail for any of the following
14084 reasons:
14086 -- Attempting to create "pointer to member of T" when T
14087 is not a class type. */
14091 }
14093 {
14097 }
14099 {
14103 }
14106 {
14107 /* The type of the implicit object parameter gets its
14108 cv-qualifiers from the FUNCTION_TYPE. */
14109 tree memptr;
14110 tree method_type
14115 complain);
14116 }
14117 else
14120 complain);
14121 }
14124 {
14125 tree fntype;
14126 tree specs;
14131 /* Substitute the exception specification. */
14139 }
14141 {
14146 /* As an optimization, we avoid regenerating the array type if
14147 it will obviously be the same as T. */
14151 /* These checks should match the ones in create_array_type_for_decl.
14153 [temp.deduct]
14155 The deduction may fail for any of the following reasons:
14157 -- Attempting to create an array with an element type that
14158 is void, a function type, or a reference type, or [DR337]
14159 an abstract class type. */
14165 {
14169 }
14177 {
14180 }
14183 }
14186 {
14198 {
14202 }
14204 {
14205 /* Normally, make_typename_type does not require that the CTX
14206 have complete type in order to allow things like:
14208 template <class T> struct S { typename S<T>::X Y; };
14210 But, such constructs have already been resolved by this
14211 point, so here CTX really should have complete type, unless
14212 it's a partial instantiation. */
14215 {
14219 }
14220 }
14227 {
14230 }
14233 {
14235 {
14239 else
14241 }
14243 {
14247 else
14249 }
14250 }
14252 return cp_build_qualified_type_real
14254 }
14257 {
14269 }
14272 {
14273 tree type;
14289 complain);
14290 }
14293 {
14294 tree type;
14305 {
14307 {
14311 }
14314 }
14325 else
14326 {
14330 /* In a template ~id could be either a complement expression
14331 or an unqualified-id naming a destructor; if instantiating
14332 it produces an expression, it's not an id-expression or
14333 member access. */
14336 }
14341 }
14344 {
14348 }
14352 {
14353 tree r;
14357 else
14365 }
14380 /* We should use one of the expression tsubsts for these codes. */
14386 }
14387 }
14389 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14390 expression on the left-hand side of the "." or "->" operator. A
14391 baselink indicates a function from a base class. Both the
14392 BASELINK_ACCESS_BINFO and the base class referenced may indicate
14393 bases of the template class, rather than the instantiated class.
14394 In addition, lookups that were not ambiguous before may be
14395 ambiguous now. Therefore, we perform the lookup again. */
14397 static tree
14400 {
14413 {
14420 }
14428 {
14433 }
14435 /* If lookup found a single function, mark it as used at this point.
14436 (If it lookup found multiple functions the one selected later by
14437 overload resolution will be marked as used at that point.) */
14445 {
14446 /* Add back the template arguments, if present. */
14452 /* Update the conversion operator type. */
14454 }
14460 {
14462 qualifying_scope,
14463 object_type);
14465 /* We need to call adjust_result_of_qualified_name_lookup in case the
14466 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14467 so that we still get virtual function binding. */
14469 }
14472 }
14474 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14475 true if the qualified-id will be a postfix-expression in-and-of
14476 itself; false if more of the postfix-expression follows the
14477 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14478 of "&". */
14480 static tree
14484 {
14485 tree expr;
14486 tree scope;
14487 tree name;
14489 tree template_args;
14494 /* Figure out what name to look up. */
14497 {
14507 }
14508 else
14509 {
14512 }
14514 /* Substitute into the qualifying scope. When there are no ARGS, we
14515 are just trying to simplify a non-dependent expression. In that
14516 case the qualifying scope may be dependent, and, in any case,
14517 substituting will not help. */
14520 {
14523 }
14524 else
14528 {
14535 }
14538 {
14540 {
14541 /* A BIT_NOT_EXPR is used to represent a destructor. */
14543 {
14547 }
14548 else
14551 }
14552 else
14556 {
14558 {
14562 }
14564 }
14565 }
14568 {
14570 scope);
14571 /* Remember that there was a reference to this entity. */
14574 }
14577 {
14583 }
14586 {
14589 complain);
14590 else
14592 }
14598 {
14599 expr = (adjust_result_of_qualified_name_lookup
14601 expr = (finish_qualified_id_expr
14605 }
14607 /* Expressions do not generally have reference type. */
14609 /* However, if we're about to form a pointer-to-member, we just
14610 want the referenced member referenced. */
14618 }
14620 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14621 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14622 for tsubst. */
14624 static tree
14627 {
14634 {
14635 /* If we had an initializer but it
14636 instantiated to nothing,
14637 value-initialize the object. This will
14638 only occur when the initializer was a
14639 pack expansion where the parameter packs
14640 used in that expansion were of length
14641 zero. */
14643 complain);
14648 }
14651 }
14653 /* Like tsubst, but deals with expressions. This function just replaces
14654 template parms; to finish processing the resultant expression, use
14655 tsubst_copy_and_build or tsubst_expr. */
14657 static tree
14659 {
14661 tree r;
14669 {
14674 {
14675 /* We get here for a use of 'this' in an NSDMI. */
14679 /* This can happen for a parameter name used later in a function
14680 declaration (such as in a late-specified return type). Just
14681 make a dummy decl, since it's only used for its type. */
14684 /* Give it the template pattern as its context; its true context
14685 hasn't been instantiated yet and this is good enough for
14686 mangling. */
14688 }
14697 {
14698 tree enum_type;
14699 tree v;
14703 /* There is no need to substitute into namespace-scope
14704 enumerators. */
14707 /* If ARGS is NULL, then T is known to be non-dependent. */
14711 /* Unfortunately, we cannot just call lookup_name here.
14712 Consider:
14714 template <int I> int f() {
14715 enum E { a = I };
14716 struct S { void g() { E e = a; } };
14717 };
14719 When we instantiate f<7>::S::g(), say, lookup_name is not
14720 clever enough to find f<7>::a. */
14721 enum_type
14731 /* We didn't find the name. That should never happen; if
14732 name-lookup found it during preliminary parsing, we
14733 should find it again here during instantiation. */
14735 }
14740 {
14741 /* Check for a local specialization set up by
14742 tsubst_pack_expansion. */
14744 {
14748 }
14750 /* When retrieving a capture pack from a generic lambda, remove the
14751 lambda call op's own template argument list from ARGS. Only the
14752 template arguments active for the closure type should be used to
14753 retrieve the pack specialization. */
14759 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14760 tsubst_decl put in the hash table. */
14762 }
14765 {
14766 tree ctx;
14771 {
14774 {
14778 }
14780 }
14781 }
14791 {
14794 {
14795 /* First try name lookup to find the instantiation. */
14798 {
14799 /* Make sure that the one we found is the one we want. */
14803 }
14807 else
14808 {
14809 /* This can happen for a variable used in a
14810 late-specified return type of a local lambda, or for a
14811 local static or constant. Building a new VAR_DECL
14812 should be OK in all those cases. */
14815 /* Avoid infinite recursion (79640). */
14818 {
14819 /* We can't call cp_finish_decl, so handle the
14820 initializer by hand. */
14835 }
14842 }
14843 /* Remember this for subsequent uses. */
14846 }
14847 }
14848 else
14858 /* An OVERLOAD will always be a non-dependent overload set; an
14859 overload set from function scope will just be represented with an
14860 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14862 /* We must have marked any lookups as persistent. */
14878 {
14879 /* Template template argument like the following example need
14880 special treatment:
14882 template <template <class> class TT> struct C {};
14883 template <class T> struct D {
14884 template <class U> struct E {};
14885 C<E> c; // #1
14886 };
14887 D<int> d; // #2
14889 We are processing the template argument `E' in #1 for
14890 the template instantiation #2. Originally, `E' is a
14891 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14892 have to substitute this with one having context `D<int>'. */
14896 {
14897 /* When rewriting a constructor into a deduction guide, a
14898 non-dependent name can become dependent, so memtmpl<args>
14899 becomes context::template memtmpl<args>. */
14903 }
14905 }
14906 else
14907 /* Ordinary template template argument. */
14918 {
14922 }
14927 {
14936 /* We only want to compute the number of arguments. */
14939 else
14946 {
14948 /* Set TREE_USED for the benefit of -Wunused. */
14952 }
14960 {
14965 else
14971 else
14974 }
14975 else
14977 }
14979 {
14987 }
14988 /* Fall through */
15004 {
15008 }
15011 {
15012 tree object;
15013 tree name;
15018 {
15022 }
15025 {
15035 }
15040 in_decl);
15041 else
15044 }
15082 {
15086 }
15089 {
15094 }
15097 {
15101 }
15104 {
15112 }
15118 {
15125 }
15128 {
15135 }
15138 {
15145 }
15148 {
15149 /* Substituted template arguments */
15158 }
15161 {
15181 }
15206 /* Fall through. */
15209 {
15212 }
15213 else
15217 /* This is handled by tsubst_copy_and_build. */
15221 {
15225 }
15228 /* We shouldn't have built any of these during initial template
15229 generation. Instead, they should be built during instantiation
15230 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15234 {
15244 }
15262 {
15263 /* Instantiate any typedefs in the type. */
15268 }
15271 /* These can sometimes show up in a partial instantiation, but never
15272 involve template parms. */
15288 /* We shouldn't get here, but keep going if !flag_checking. */
15292 }
15293 }
15295 /* Helper function for tsubst_omp_clauses, used for instantiation of
15296 OMP_CLAUSE_DECL of clauses. */
15298 static tree
15300 tree in_decl)
15301 {
15305 /* Handle an OpenMP array section represented as a TREE_LIST (or
15306 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15307 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15308 TREE_LIST. We can handle it exactly the same as an array section
15309 (purpose, value, and a chain), even though the nomenclature
15310 (low_bound, length, etc) is different. */
15312 {
15313 tree low_bound
15319 in_decl);
15328 }
15331 /* Undo convert_from_reference tsubst_expr could have called. */
15337 }
15339 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15341 static tree
15344 {
15349 {
15355 {
15358 {
15364 }
15365 /* FALLTHRU */
15380 in_decl);
15412 {
15415 {
15422 }
15423 else
15425 }
15428 in_decl);
15434 in_decl);
15442 in_decl);
15444 {
15447 }
15452 else
15455 in_decl,
15479 }
15482 {
15492 /* tsubst_expr on SCOPE_REF results in returning
15493 finish_non_static_data_member result. Undo that here. */
15497 {
15502 {
15506 CASE_CONVERT:
15515 /* FALLTHRU */
15519 }
15520 }
15526 {
15529 {
15532 }
15533 }
15537 }
15538 }
15542 {
15547 {
15550 }
15551 }
15553 }
15555 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15557 static tree
15559 tree in_decl)
15560 {
15561 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15581 {
15584 else
15585 {
15589 }
15590 }
15595 #undef RECUR
15596 }
15598 /* Used to temporarily communicate the list of #pragma omp parallel
15599 clauses to #pragma omp for instantiation if they are combined
15600 together. */
15604 /* Substitute one OMP_FOR iterator. */
15606 static void
15611 {
15612 #define RECUR(NODE) \
15613 tsubst_expr ((NODE), args, complain, in_decl, \
15614 integral_constant_expression_p)
15621 {
15624 }
15630 {
15631 /* We need to jump through some hoops to handle declarations in the
15632 init-statement, since we might need to handle auto deduction,
15633 but we need to keep control of initialization. */
15637 }
15638 else
15639 {
15641 {
15644 {
15648 {
15652 CASE_CONVERT:
15660 {
15663 }
15664 /* FALLTHRU */
15668 }
15669 }
15670 }
15671 else
15673 }
15684 {
15686 {
15687 /* Declare the variable, but don't let that initialize it. */
15692 }
15697 {
15702 }
15703 else
15710 }
15713 {
15714 /* Declare and initialize the variable. */
15717 }
15719 {
15723 {
15725 {
15731 {
15734 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15739 }
15742 {
15744 decl);
15746 }
15749 {
15751 decl);
15753 }
15754 else
15756 }
15759 }
15761 {
15766 {
15769 }
15770 }
15771 }
15774 {
15778 }
15779 else
15783 {
15794 {
15802 }
15803 else
15809 {
15815 }
15819 {
15827 }
15828 else
15834 }
15840 #undef RECUR
15841 }
15843 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15844 of OMP_TARGET's body. */
15846 static tree
15848 {
15851 {
15860 }
15862 }
15864 /* Helper function for tsubst_expr. For decomposition declaration
15865 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15866 also the corresponding decls representing the identifiers
15867 of the decomposition declaration. Return DECL if successful
15868 or error_mark_node otherwise, set *FIRST to the first decl
15869 in the list chained through DECL_CHAIN and *CNT to the number
15870 of such decls. */
15872 static tree
15876 {
15881 decl2
15886 {
15888 {
15891 }
15908 {
15911 }
15912 else
15914 }
15917 }
15919 /* Like tsubst_copy for expressions, etc. but also does semantic
15920 processing. */
15922 tree
15925 {
15926 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15927 #define RECUR(NODE) \
15928 tsubst_expr ((NODE), args, complain, in_decl, \
15929 integral_constant_expression_p)
15932 tree r;
15933 location_t loc;
15945 {
15947 {
15948 tree_stmt_iterator i;
15952 }
15967 else
15977 {
15979 tree init;
15985 {
15995 else
15997 }
15999 {
16000 /* Don't build up decls for a variadic capture proxy, we'll
16001 instantiate the elements directly as needed. */
16003 }
16006 {
16007 /* We're in tsubst_lambda_expr, we've already inserted a new
16008 capture proxy, so look it up and register it. */
16014 }
16017 /* Don't copy the old closure; we'll create a new one in
16018 tsubst_lambda_expr. */
16020 else
16021 {
16025 {
16026 /* By marking the declaration as instantiated, we avoid
16027 trying to instantiate it. Since instantiate_decl can't
16028 handle local variables, and since we've already done
16029 all that needs to be done, that's the right thing to
16030 do. */
16035 /* Anonymous aggregates are a special case. */
16038 {
16041 {
16045 }
16047 }
16053 {
16058 }
16059 else
16060 {
16065 {
16066 /* For __PRETTY_FUNCTION__ we have to adjust the
16067 initializer. */
16071 }
16072 else
16076 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16082 {
16084 tree first;
16090 }
16091 }
16092 }
16093 }
16096 }
16111 {
16119 {
16121 tree first;
16126 }
16127 else
16132 }
16158 else
16159 {
16166 }
16172 {
16181 }
16189 else
16197 else
16218 {
16225 }
16229 {
16231 tree label;
16238 }
16244 /* Computed goto's must be tsubst'd into. On the other hand,
16245 non-computed gotos must not be; the identifier in question
16246 will have no binding. */
16248 else
16254 {
16270 }
16275 {
16280 }
16281 else
16282 {
16287 else
16294 else
16300 else
16302 }
16306 {
16310 {
16312 /* Prevent instantiate_decl from trying to instantiate
16313 this variable. We've already done all that needs to be
16314 done. */
16317 }
16322 }
16328 {
16329 /* Local classes are not independent templates; they are
16330 instantiated along with their containing function. And this
16331 way we don't have to deal with pushing out of one local class
16332 to instantiate a member of another local class. */
16333 /* Closures are handled by the LAMBDA_EXPR. */
16343 }
16347 {
16348 tree condition;
16351 condition =
16353 args,
16362 }
16368 in_decl);
16405 {
16420 in_decl);
16422 {
16429 }
16441 integral_constant_expression_p);
16452 else
16453 {
16461 }
16465 }
16470 /* FALLTHRU */
16477 in_decl);
16494 in_decl);
16505 {
16508 {
16509 /* For combined target teams, ensure the num_teams and
16510 thread_limit clause expressions are evaluated on the host,
16511 before entering the target construct. */
16512 tree c;
16518 {
16527 OMP_CLAUSE_FIRSTPRIVATE);
16531 }
16532 }
16533 }
16593 {
16598 {
16601 }
16607 }
16608 else
16609 {
16616 {
16619 }
16622 {
16627 {
16630 }
16636 }
16637 else
16638 {
16642 }
16645 }
16649 {
16655 {
16659 {
16664 }
16668 }
16669 else
16670 {
16675 }
16676 }
16680 {
16684 }
16704 /* If the first operand was a statement, we're done with it. */
16708 complain));
16720 integral_constant_expression_p));
16721 }
16724 out:
16727 #undef RECUR
16728 #undef RETURN
16729 }
16731 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16732 function. For description of the body see comment above
16733 cp_parser_omp_declare_reduction_exprs. */
16735 static void
16737 {
16743 tree_stmt_iterator tsi;
16754 {
16773 }
16775 {
16795 }
16796 }
16798 /* T is a postfix-expression that is not being used in a function
16799 call. Return the substituted version of T. */
16801 static tree
16803 tsubst_flags_t complain,
16804 tree in_decl)
16805 {
16809 else
16815 }
16817 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16818 instantiation context. Instantiating a pack expansion containing a lambda
16819 might result in multiple lambdas all based on the same lambda in the
16820 template. */
16822 tree
16824 {
16838 else
16846 {
16858 else
16863 {
16872 }
16873 else
16874 {
16880 }
16881 }
16885 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
16903 else
16904 {
16905 /* Fix the type of 'this'. */
16911 {
16915 }
16916 else
16917 {
16921 }
16923 /* Let finish_function set this. */
16944 /* The capture list was built up in reverse order; fix that now. */
16951 }
16958 }
16960 /* Like tsubst but deals with expressions and performs semantic
16961 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16963 tree
16965 tree args,
16966 tsubst_flags_t complain,
16967 tree in_decl,
16970 {
16971 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16972 #define RECUR(NODE) \
16973 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16975 integral_constant_expression_p)
16978 location_t loc;
16987 /* N3276 decltype magic only applies to calls at the top level or on the
16988 right side of a comma. */
16993 {
16996 /* Fall through. */
16998 {
16999 tree decl;
17000 cp_id_kind idk;
17005 {
17008 }
17010 /* Look up the name. */
17013 /* By convention, expressions use ERROR_MARK_NODE to indicate
17014 failure, not NULL_TREE. */
17020 integral_constant_expression_p,
17028 input_location);
17032 {
17036 }
17038 }
17041 {
17042 tree object;
17052 {
17057 }
17063 {
17066 }
17067 else
17074 else
17076 }
17079 {
17083 {
17084 /* A type conversion to reference type will be enclosed in
17085 such an indirect ref, but the substitution of the cast
17086 will have also added such an indirect ref. */
17088 }
17089 else
17097 }
17100 {
17104 }
17107 {
17114 flags));
17115 }
17118 {
17122 }
17129 {
17130 tree type;
17136 {
17141 }
17147 {
17165 }
17168 }
17202 else
17204 in_decl);
17239 {
17246 tree r = build_x_binary_op
17248 op0,
17250 ? ERROR_MARK
17252 op1,
17254 ? ERROR_MARK
17262 }
17265 {
17269 }
17282 {
17291 }
17296 /* Fall through */
17299 {
17300 tree r;
17306 {
17307 /* When there are no ARGS, we are trying to evaluate a
17308 non-dependent expression from the parser. Trying to do
17309 the substitutions may not work. */
17312 }
17313 else
17314 {
17319 else
17322 /*integral_constant_expression_p=*/
17326 }
17330 else
17334 {
17336 {
17338 {
17342 }
17343 else
17347 }
17349 }
17351 }
17354 {
17364 }
17380 {
17384 tree r = build_x_modify_expr
17387 /* TREE_NO_WARNING must be set if either the expression was
17388 parenthesized or it uses an operator such as >>= rather
17389 than plain assignment. In the former case, it was already
17390 set and must be copied. In the latter case,
17391 build_x_modify_expr sets it and it must not be reset
17392 here. */
17397 }
17402 /* Remember that there was a reference to this entity. */
17409 {
17414 tree ret;
17418 else
17419 {
17423 }
17425 /* If there was an initializer in the original tree, but it
17426 instantiated to an empty list, then we should pass a
17427 non-NULL empty vector to tell build_new that it was an
17428 empty initializer() rather than no initializer. This can
17429 only happen when the initializer is a pack expansion whose
17430 parameter packs are of length zero. */
17433 else
17434 {
17438 else
17439 {
17442 }
17443 }
17449 complain);
17457 }
17460 {
17466 complain));
17467 }
17470 {
17474 integral_constant_expression_p);
17476 op0,
17479 }
17482 {
17483 tree function;
17488 tree ret;
17491 /* Internal function with no arguments. */
17495 /* When we parsed the expression, we determined whether or
17496 not Koenig lookup should be performed. */
17499 {
17502 }
17504 {
17509 }
17511 {
17512 /* Do nothing; calling tsubst_copy_and_build on an identifier
17513 would incorrectly perform unqualified lookup again.
17515 Note that we can also have an IDENTIFIER_NODE if the earlier
17516 unqualified lookup found a member function; in that case
17517 koenig_p will be false and we do want to do the lookup
17518 again to find the instantiated member function.
17520 FIXME but doing that causes c++/15272, so we need to stop
17521 using IDENTIFIER_NODE in that situation. */
17523 }
17524 else
17525 {
17527 {
17533 }
17534 else
17539 /* Avoid error about taking the address of a constructor. */
17543 in_decl,
17545 integral_constant_expression_p);
17549 }
17554 {
17559 else
17560 {
17561 /* Expand the pack expansion and push each entry onto
17562 CALL_ARGS. */
17565 {
17570 {
17575 }
17576 }
17577 else
17578 {
17579 /* A partial substitution. Add one entry. */
17581 }
17582 }
17583 }
17585 /* We do not perform argument-dependent lookup if normal
17586 lookup finds a non-function, in accordance with the
17587 expected resolution of DR 218. */
17590 /* If lookup found a member function, the Koenig lookup is
17591 not appropriate, even if an unqualified-name was used
17592 to denote the function. */
17595 /* Only do this when substitution turns a dependent call
17596 into a non-dependent call. */
17604 {
17606 {
17607 /* For backwards compatibility and good diagnostics, try
17608 the unqualified lookup again if we aren't in SFINAE
17609 context. */
17610 tree unq = (tsubst_copy_and_build
17612 integral_constant_expression_p));
17614 {
17617 }
17620 {
17621 /* In a lambda fn, we have to be careful to not
17622 introduce new this captures. Legacy code can't
17623 be using lambdas anyway, so it's ok to be
17624 stricter. */
17629 "and no declarations were found by "
17630 "argument-dependent lookup at the point "
17637 else
17641 {
17652 {
17654 input_location);
17656 "declarations in dependent base %qT are "
17662 else
17666 }
17667 else
17669 "%qD declared here, later in the "
17672 {
17675 }
17676 }
17679 }
17680 }
17682 {
17687 }
17688 }
17690 /* Remember that there was a reference to this entity. */
17694 {
17697 }
17699 /* Put back tf_decltype for the actual call. */
17704 {
17708 {
17710 "wrong number of arguments to "
17713 }
17714 else
17716 input_location),
17721 /* Unsupported internal function with arguments. */
17723 }
17726 complain);
17728 {
17743 complain);
17744 else
17745 ret = (build_new_method_call
17750 complain));
17751 }
17752 else
17755 koenig_p,
17756 complain);
17761 {
17767 {
17773 {
17775 /* The thunk location is not interesting. */
17777 }
17778 }
17779 }
17782 }
17785 {
17791 {
17793 {
17798 }
17799 else
17800 {
17805 }
17807 }
17808 else
17809 {
17812 }
17816 }
17819 {
17824 input_location));
17825 }
17828 {
17836 {
17837 /* We have pack expansions, so expand those and
17838 create a new list out of it. */
17841 tree chain;
17844 /* Expand the argument expressions. */
17852 /* Build the rest of the list. */
17857 /* Determine the number of arguments. */
17859 {
17862 }
17865 else
17866 {
17867 /* Since we only performed a partial substitution into
17868 the argument pack, we only RETURN (a single list
17869 node. */
17876 }
17878 /* Convert the argument vectors into a TREE_LIST */
17881 {
17882 /* Grab the Ith values. */
17883 i--;
17886 value
17890 /* Build the list (backwards). */
17892 }
17895 }
17911 }
17914 {
17915 tree object;
17916 tree object_type;
17917 tree member;
17918 tree r;
17922 /* Remember that there was a reference to this entity. */
17933 else
17939 {
17944 }
17948 {
17950 {
17955 {
17958 }
17960 {
17965 }
17966 }
17967 }
17970 {
17971 /* Lookup the template functions now that we know what the
17972 scope is. */
17980 {
17983 args);
17984 member = (adjust_result_of_qualified_name_lookup
17986 object_type));
17987 }
17988 else
17989 {
17991 input_location);
17993 }
17994 }
17998 {
18000 {
18004 else
18007 }
18009 }
18013 complain);
18017 }
18024 {
18032 tree r;
18037 /* digest_init will do the wrong thing if we let it. */
18041 /* We do not want to process the index of aggregate
18042 initializers as they are identifier nodes which will be
18043 looked up by digest_init. */
18049 {
18051 /* An identifier index is looked up in the type
18052 being initialized, not the current scope. */
18057 {
18058 /* Substitute into the pack expansion. */
18060 in_decl);
18064 ;
18066 /* Just move the argument into place. */
18068 else
18069 {
18070 /* Update the length of the final CONSTRUCTOR
18071 arguments vector, and note that we will need to
18072 copy.*/
18075 }
18076 }
18077 else
18079 }
18082 {
18087 {
18089 {
18094 }
18095 else
18097 }
18098 }
18104 {
18109 }
18113 }
18116 {
18119 {
18122 }
18123 else
18124 {
18127 }
18128 }
18134 {
18135 /* We don't build decls for an instantiation of a
18136 variadic capture proxy, we instantiate the elements
18137 when needed. */
18140 }
18141 /* Fall through */
18144 {
18146 /* ??? We're doing a subset of finish_id_expression here. */
18148 && !processing_template_decl
18149 && !cp_unevaluated_operand
18152 {
18154 /* Replace an evaluated use of the thread_local variable with
18155 a call to its wrapper. */
18157 }
18162 /* If the original type was a reference, we'll be wrapped in
18163 the appropriate INDIRECT_REF. */
18166 }
18169 {
18173 }
18176 {
18177 tree object_ptr
18184 }
18191 {
18202 }
18205 {
18211 integral_constant_expression_p);
18215 /* If the resulting list of expression statement is empty,
18216 fold it further into void_node. */
18221 }
18224 {
18228 }
18231 /* We can get here for a constant initializer of non-dependent type.
18232 FIXME stop folding in cp_parser_initializer_clause. */
18233 {
18235 complain);
18237 }
18241 integral_constant_expression_p));
18247 {
18252 complain));
18253 }
18259 /* Handle Objective-C++ constructs, if appropriate. */
18260 {
18261 tree subst
18266 }
18268 }
18270 #undef RECUR
18271 #undef RETURN
18272 out:
18275 }
18277 /* Verify that the instantiated ARGS are valid. For type arguments,
18278 make sure that the type's linkage is ok. For non-type arguments,
18279 make sure they are constants if they are integral or enumerations.
18280 Emit an error under control of COMPLAIN, and return TRUE on error. */
18282 static bool
18284 {
18288 {
18298 }
18300 {
18301 /* [basic.link]: A name with no linkage (notably, the name
18302 of a class or enumeration declared in a local scope)
18303 shall not be used to declare an entity with linkage.
18304 This implies that names with no linkage cannot be used as
18305 template arguments
18307 DR 757 relaxes this restriction for C++0x. */
18312 {
18313 /* DR 488 makes use of a type with no linkage cause
18314 type deduction to fail. */
18316 {
18319 else
18322 }
18324 }
18325 /* In order to avoid all sorts of complications, we do not
18326 allow variably-modified types as template arguments. */
18328 {
18332 }
18333 }
18334 /* Class template and alias template arguments should be OK. */
18336 ;
18337 /* A non-type argument of integral or enumerated type must be a
18338 constant. */
18343 {
18347 }
18349 }
18351 static bool
18353 {
18358 {
18361 }
18365 }
18367 /* We're out of SFINAE context now, so generate diagnostics for the access
18368 errors we saw earlier when instantiating D from TMPL and ARGS. */
18370 static void
18372 {
18384 }
18386 /* Instantiate the indicated variable, function, or alias template TMPL with
18387 the template arguments in TARG_PTR. */
18389 static tree
18391 {
18393 tree fndecl;
18394 tree gen_tmpl;
18395 tree spec;
18403 /* If this function is a clone, handle it specially. */
18405 {
18406 tree spec;
18407 tree clone;
18409 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18410 DECL_CLONED_FUNCTION. */
18416 /* Look for the clone. */
18420 /* We should always have found the clone by now. */
18423 }
18428 /* Check to see if we already have this specialization. */
18432 /* targ_ptr only has the innermost template args, so add the outer ones
18433 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18434 the case of a non-dependent call within a template definition). */
18435 targ_ptr = (add_outermost_template_args
18437 targ_ptr));
18439 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18440 but it doesn't seem to be on the hot path. */
18449 {
18451 {
18455 }
18457 }
18460 complain))
18463 /* We are building a FUNCTION_DECL, during which the access of its
18464 parameters and return types have to be checked. However this
18465 FUNCTION_DECL which is the desired context for access checking
18466 is not built yet. We solve this chicken-and-egg problem by
18467 deferring all checks until we have the FUNCTION_DECL. */
18470 /* Instantiation of the function happens in the context of the function
18471 template, not the context of the overload resolution we're doing. */
18473 /* If there are dependent arguments, e.g. because we're doing partial
18474 ordering, make sure processing_template_decl stays set. */
18478 {
18482 }
18488 {
18489 /* We need to determine if we're using a partial or explicit
18490 specialization now, because the type of the variable could be
18491 different. */
18497 {
18502 }
18503 }
18505 /* Substitute template parameters to obtain the specialization. */
18513 {
18516 }
18518 /* The DECL_TI_TEMPLATE should always be the immediate parent
18519 template, not the most general template. */
18523 /* Now we know the specialization, compute access previously
18524 deferred. Do no access control for inheriting constructors,
18525 as we already checked access for the inherited constructor. */
18528 {
18533 }
18536 /* If we've just instantiated the main entry point for a function,
18537 instantiate all the alternate entry points as well. We do this
18538 by cloning the instantiation of the main entry point, not by
18539 instantiating the template clones. */
18544 {
18546 {
18547 /* Remember to reinstantiate when we're out of SFINAE so the user
18548 can see the errors. */
18550 }
18552 }
18554 }
18556 /* Wrapper for instantiate_template_1. */
18558 tree
18560 {
18561 tree ret;
18566 }
18568 /* Instantiate the alias template TMPL with ARGS. Also push a template
18569 instantiation level, which instantiate_template doesn't do because
18570 functions and variables have sufficient context established by the
18571 callers. */
18573 static tree
18575 {
18582 {
18585 }
18587 args =
18595 /* We can't free this if a pending_template entry or last_error_tinst_level
18596 is pointing at it. */
18602 }
18604 /* PARM is a template parameter pack for FN. Returns true iff
18605 PARM is used in a deducible way in the argument list of FN. */
18607 static bool
18609 {
18612 {
18614 tree packs;
18620 {
18621 /* The template parameter pack is used in a function parameter
18622 pack. If this is the end of the parameter list, the
18623 template parameter pack is deducible. */
18626 else
18627 /* Otherwise, not. Well, it could be deduced from
18628 a non-pack parameter, but doing so would end up with
18629 a deduction mismatch, so don't bother. */
18631 }
18632 }
18633 /* The template parameter pack isn't used in any function parameter
18634 packs, but it might be used deeper, e.g. tuple<Args...>. */
18636 }
18638 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18639 NARGS elements of the arguments that are being used when calling
18640 it. TARGS is a vector into which the deduced template arguments
18641 are placed.
18643 Returns either a FUNCTION_DECL for the matching specialization of FN or
18644 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18645 true, diagnostics will be printed to explain why it failed.
18647 If FN is a conversion operator, or we are trying to produce a specific
18648 specialization, RETURN_TYPE is the return type desired.
18650 The EXPLICIT_TARGS are explicit template arguments provided via a
18651 template-id.
18653 The parameter STRICT is one of:
18655 DEDUCE_CALL:
18656 We are deducing arguments for a function call, as in
18657 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18658 deducing arguments for a call to the result of a conversion
18659 function template, as in [over.call.object].
18661 DEDUCE_CONV:
18662 We are deducing arguments for a conversion function, as in
18663 [temp.deduct.conv].
18665 DEDUCE_EXACT:
18666 We are deducing arguments when doing an explicit instantiation
18667 as in [temp.explicit], when determining an explicit specialization
18668 as in [temp.expl.spec], or when taking the address of a function
18669 template, as in [temp.deduct.funcaddr]. */
18671 tree
18673 tree explicit_targs,
18674 tree targs,
18677 tree return_type,
18678 unification_kind_t strict,
18682 {
18683 tree parms;
18684 tree fntype;
18697 tree tinst;
18703 full_targs = (add_outermost_template_args
18705 targs));
18710 /* In C++0x, it's possible to have a function template whose type depends
18711 on itself recursively. This is most obvious with decltype, but can also
18712 occur with enumeration scope (c++/48969). So we need to catch infinite
18713 recursion and reject the substitution at deduction time; this function
18714 will return error_mark_node for any repeated substitution.
18716 This also catches excessive recursion such as when f<N> depends on
18717 f<N-1> across all integers, and returns error_mark_node for all the
18718 substitutions back up to the initial one.
18720 This is, of course, not reentrant. */
18730 {
18731 /* [temp.deduct]
18733 The specified template arguments must match the template
18734 parameters in kind (i.e., type, nontype, template), and there
18735 must not be more arguments than there are parameters;
18736 otherwise type deduction fails.
18738 Nontype arguments must match the types of the corresponding
18739 nontype template parameters, or must be convertible to the
18740 types of the corresponding nontype parameters as specified in
18741 _temp.arg.nontype_, otherwise type deduction fails.
18743 All references in the function type of the function template
18744 to the corresponding template parameters are replaced by the
18745 specified template argument values. If a substitution in a
18746 template parameter or in the function type of the function
18747 template results in an invalid type, type deduction fails. */
18758 explicit_targs);
18760 /* Adjust any explicit template arguments before entering the
18761 substitution context. */
18762 explicit_targs
18764 complain,
18770 /* Substitute the explicit args into the function type. This is
18771 necessary so that, for instance, explicitly declared function
18772 arguments can match null pointed constants. If we were given
18773 an incomplete set of explicit args, we must not do semantic
18774 processing during substitution as we could create partial
18775 instantiations. */
18777 {
18782 /* Dig out the actual parm. */
18785 {
18788 }
18790 {
18793 }
18796 /* No explicit argument for this template parameter. */
18800 {
18801 /* Mark the argument pack as "incomplete". We could
18802 still deduce more arguments during unification.
18803 We remove this mark in type_unification_real. */
18805 {
18809 }
18811 /* We have some incomplete argument packs. */
18813 }
18814 }
18818 {
18821 }
18824 /* Ignore any access checks; we'll see them again in
18825 instantiate_template and they might have the wrong
18826 access path at this point. */
18838 /* Place the explicitly specified arguments in TARGS. */
18842 }
18844 /* Never do unification on the 'this' parameter. */
18848 {
18849 /* We're deducing for a call to the result of a template conversion
18850 function. The parms we really want are in return_type. */
18854 }
18856 {
18865 }
18867 /* We allow incomplete unification without an error message here
18868 because the standard doesn't seem to explicitly prohibit it. Our
18869 callers must be ready to deal with unification failures in any
18870 event. */
18873 /* If we aren't explaining yet, push tinst context so we can see where
18874 any errors (e.g. from class instantiations triggered by instantiation
18875 of default template arguments) come from. If we are explaining, this
18876 context is redundant. */
18878 {
18881 }
18883 /* type_unification_real will pass back any access checks from default
18884 template argument substitution. */
18896 /* Now that we have bindings for all of the template arguments,
18897 ensure that the arguments deduced for the template template
18898 parameters have compatible template parameter lists. We cannot
18899 check this property before we have deduced all template
18900 arguments, because the template parameter types of a template
18901 template parameter might depend on prior template parameters
18902 deduced after the template template parameter. The following
18903 ill-formed example illustrates this issue:
18905 template<typename T, template<T> class C> void f(C<5>, T);
18907 template<int N> struct X {};
18909 void g() {
18910 f(X<5>(), 5l); // error: template argument deduction fails
18911 }
18913 The template parameter list of 'C' depends on the template type
18914 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18915 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18916 time that we deduce 'C'. */
18919 {
18922 }
18924 /* All is well so far. Now, check:
18926 [temp.deduct]
18928 When all template arguments have been deduced, all uses of
18929 template parameters in nondeduced contexts are replaced with
18930 the corresponding deduced argument values. If the
18931 substitution results in an invalid type, as described above,
18932 type deduction fails. */
18935 {
18938 }
18940 /* Also collect access checks from the instantiation. */
18953 /* Now perform any access checks encountered during substitution. */
18960 /* If we're looking for an exact match, check that what we got
18961 is indeed an exact match. It might not be if some template
18962 parameters are used in non-deduced contexts. But don't check
18963 for an exact match if we have dependent template arguments;
18964 in that case we're doing partial ordering, and we already know
18965 that we have two candidates that will provide the actual type. */
18967 {
18971 tree sarg
18977 {
18981 }
18982 }
18984 /* After doing deduction with the inherited constructor, actually return an
18985 instantiation of the inheriting constructor. */
18991 fail:
18994 {
18996 /* Reset once we're all the way out. */
18998 }
19000 /* We can't free this if a pending_template entry or last_error_tinst_level
19001 is pointing at it. */
19007 }
19009 /* Adjust types before performing type deduction, as described in
19010 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
19011 sections are symmetric. PARM is the type of a function parameter
19012 or the return type of the conversion function. ARG is the type of
19013 the argument passed to the call, or the type of the value
19014 initialized with the result of the conversion function.
19015 ARG_EXPR is the original argument expression, which may be null. */
19017 static int
19021 tree arg_expr)
19022 {
19026 {
19031 /* Swap PARM and ARG throughout the remainder of this
19032 function; the handling is precisely symmetric since PARM
19033 will initialize ARG rather than vice versa. */
19038 /* Core issue #873: Do the DR606 thing (see below) for these cases,
19039 too, but here handle it by stripping the reference from PARM
19040 rather than by adding it to ARG. */
19048 /* Nothing else to do in this case. */
19053 }
19056 {
19057 /* [temp.deduct.call]
19059 If P is not a reference type:
19061 --If A is an array type, the pointer type produced by the
19062 array-to-pointer standard conversion (_conv.array_) is
19063 used in place of A for type deduction; otherwise,
19065 --If A is a function type, the pointer type produced by
19066 the function-to-pointer standard conversion
19067 (_conv.func_) is used in place of A for type deduction;
19068 otherwise,
19070 --If A is a cv-qualified type, the top level
19071 cv-qualifiers of A's type are ignored for type
19072 deduction. */
19077 else
19079 }
19081 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19082 reference to a cv-unqualified template parameter that does not represent a
19083 template parameter of a class template (during class template argument
19084 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19085 an lvalue, the type "lvalue reference to A" is used in place of A for type
19086 deduction. */
19093 /* try_one_overload doesn't provide an arg_expr, but
19094 functions are always lvalues. */
19098 /* [temp.deduct.call]
19100 If P is a cv-qualified type, the top level cv-qualifiers
19101 of P's type are ignored for type deduction. If P is a
19102 reference type, the type referred to by P is used for
19103 type deduction. */
19106 {
19109 }
19111 /* DR 322. For conversion deduction, remove a reference type on parm
19112 too (which has been swapped into ARG). */
19117 }
19119 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19120 template which does contain any deducible template parameters; check if
19121 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19122 unify_one_argument. */
19124 static int
19127 {
19128 tree type;
19132 else
19139 {
19143 }
19145 {
19150 }
19154 else
19156 }
19160 /* Returns true iff the expression EXPR is one from which a template
19161 argument can be deduced. In other words, if it's an undecorated
19162 use of a template non-type parameter. */
19164 static bool
19166 {
19167 /* Strip implicit conversions. */
19171 }
19173 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19174 deducible way; that is, if it has a max value of <PARM> - 1. */
19176 static bool
19178 {
19187 }
19189 /* Returns true iff the template arguments ARGS use a template parameter
19190 in a deducible way. */
19192 static bool
19194 {
19196 {
19201 else
19202 {
19209 else
19211 }
19214 }
19216 }
19218 /* Returns true iff TYPE contains any deducible references to template
19219 parameters, as per 14.8.2.5. */
19221 static bool
19223 {
19227 /* T
19228 cv-list T
19229 TT<T>
19230 TT<i>
19231 TT<> */
19236 /* T*
19237 T&
19238 T&& */
19242 /* T[integer-constant ]
19243 type [i] */
19248 /* T type ::*
19249 type T::*
19250 T T::*
19251 T (type ::*)()
19252 type (T::*)()
19253 type (type ::*)(T)
19254 type (T::*)(T)
19255 T (type ::*)(T)
19256 T (T::*)()
19257 T (T::*)(T) */
19260 || (uses_deducible_template_parms
19263 /* template-name <T> (where template-name refers to a class template)
19264 template-name <i> (where template-name refers to a class template) */
19271 /* type (T)
19272 T()
19273 T(T) */
19276 {
19285 }
19288 }
19290 /* Subroutine of type_unification_real and unify_pack_expansion to
19291 handle unification of a single P/A pair. Parameters are as
19292 for those functions. */
19294 static int
19298 {
19305 /* We can't deduce anything from this, but we might get all the
19306 template args from other function args. */
19309 /* Implicit conversions (Clause 4) will be performed on a function
19310 argument to convert it to the type of the corresponding function
19311 parameter if the parameter type contains no template-parameters that
19312 participate in template argument deduction. */
19315 /* For function parameters with no deducible template parameters,
19316 just return. We'll check non-dependent conversions later. */
19320 {
19322 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19323 | UNIFY_ALLOW_MORE_CV_QUAL
19337 }
19339 /* We only do these transformations if this is the top-level
19340 parameter_type_list in a call or declaration matching; in other
19341 situations (nested function declarators, template argument lists) we
19342 won't be comparing a type to an expression, and we don't do any type
19343 adjustments. */
19345 {
19347 {
19350 {
19351 /* [temp.deduct.type] A template-argument can be
19352 deduced from a pointer to function or pointer
19353 to member function argument if the set of
19354 overloaded functions does not contain function
19355 templates and at most one of a set of
19356 overloaded functions provides a unique
19357 match. */
19361 /* If a unique match was not found, this is a
19362 non-deduced context, so we still succeed. */
19364 }
19370 }
19372 arg_strict |=
19374 }
19375 else
19380 /* For deduction from an init-list we need the actual list. */
19384 }
19386 /* for_each_template_parm callback that always returns 0. */
19388 static int
19390 {
19392 }
19394 /* for_each_template_parm any_fn callback to handle deduction of a template
19395 type argument from the type of an array bound. */
19397 static int
19399 {
19407 {
19413 }
19415 /* Keep walking. */
19417 }
19419 /* Try to deduce any not-yet-deduced template type arguments from the type of
19420 an array bound. This is handled separately from unify because 14.8.2.5 says
19421 "The type of a type parameter is only deduced from an array bound if it is
19422 not otherwise deduced." */
19424 static void
19426 {
19431 }
19433 /* Most parms like fn_type_unification.
19435 If SUBR is 1, we're being called recursively (to unify the
19436 arguments of a function or method parameter of a function
19437 template).
19439 CHECKS is a pointer to a vector of access checks encountered while
19440 substituting default template arguments. */
19442 static int
19444 tree full_targs,
19445 tree xparms,
19449 unification_kind_t strict,
19453 {
19458 tree parms;
19469 /* Reset the number of non-defaulted template arguments contained
19470 in TARGS. */
19473 again:
19481 {
19486 /* For a function parameter pack that occurs at the end of the
19487 parameter-declaration-list, the type A of each remaining
19488 argument of the call is compared with the type P of the
19489 declarator-id of the function parameter pack. */
19495 /* For a function parameter pack that does not occur at the
19496 end of the parameter-declaration-list, the type of the
19497 parameter pack is a non-deduced context. */
19504 explain_p))
19506 }
19511 {
19512 /* Unify the remaining arguments with the pack expansion type. */
19513 tree argvec;
19516 /* Allocate a TREE_VEC and copy in all of the arguments */
19521 /* Copy the parameter into parmvec. */
19527 /* Advance to the end of the list of parameters. */
19529 }
19531 /* Fail if we've reached the end of the parm list, and more args
19532 are present, and the parm list isn't variadic. */
19535 /* Fail if parms are left and they don't have default values and
19536 they aren't all deduced as empty packs (c++/57397). This is
19537 consistent with sufficient_parms_p. */
19540 {
19544 do
19545 {
19548 count++;
19550 }
19554 type_pack_p);
19555 }
19558 {
19559 tsubst_flags_t complain = (explain_p
19560 ? tf_warning_or_error
19565 {
19569 /* Clear the "incomplete" flags on all argument packs now so that
19570 substituting them into later default arguments works. */
19572 {
19575 }
19583 {
19588 }
19590 /* If this is an undeduced nontype parameter that depends on
19591 a type parameter, try another pass; its type may have been
19592 deduced from a later argument than the one from which
19593 this parameter can be deduced. */
19597 {
19600 }
19602 /* Core issue #226 (C++0x) [temp.deduct]:
19604 If a template argument has not been deduced, its
19605 default template argument, if any, is used.
19607 When we are in C++98 mode, TREE_PURPOSE will either
19608 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19609 to explicitly check cxx_dialect here. */
19611 /* OK, there is a default argument. Wait until after the
19612 conversion check to do substitution. */
19615 /* If the type parameter is a parameter pack, then it will
19616 be deduced to an empty parameter pack. */
19618 {
19619 tree arg;
19622 {
19625 }
19626 else
19633 }
19636 }
19638 /* DR 1391: All parameters have args, now check non-dependent parms for
19639 convertibility. */
19643 {
19649 /* For a function parameter pack that occurs at the end of the
19650 parameter-declaration-list, the type A of each remaining
19651 argument of the call is compared with the type P of the
19652 declarator-id of the function parameter pack. */
19658 /* For a function parameter pack that does not occur at the
19659 end of the parameter-declaration-list, the type of the
19660 parameter pack is a non-deduced context. */
19669 explain_p))
19671 }
19673 /* Now substitute into the default template arguments. */
19675 {
19699 else
19707 {
19709 /* The position of the first default template argument,
19710 is also the number of non-defaulted arguments in TARGS.
19711 Record that. */
19714 }
19715 }
19719 }
19725 }
19727 /* Subroutine of type_unification_real. Args are like the variables
19728 at the call site. ARG is an overloaded function (or template-id);
19729 we try deducing template args from each of the overloads, and if
19730 only one succeeds, we go with that. Modifies TARGS and returns
19731 true on success. */
19733 static bool
19735 tree targs,
19736 tree parm,
19737 tree arg,
19738 unification_kind_t strict,
19741 {
19748 {
19751 }
19752 else
19756 /* Handle `&x' where `x' is some static or non-static member
19757 function name. */
19763 /* Strip baselink information. */
19768 {
19769 /* If we got some explicit template args, we need to plug them into
19770 the affected templates before we try to unify, in case the
19771 explicit args will completely resolve the templates in question. */
19778 {
19791 {
19796 {
19799 }
19800 }
19803 }
19804 /* If no templates (or more than one) are fully resolved by the
19805 explicit arguments, this template-id is a non-deduced context; it
19806 could still be OK if we deduce all template arguments for the
19807 enclosing call through other arguments. */
19810 }
19813 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19814 -- but the deduction does not succeed because the expression is
19815 not just the function on its own. */
19817 else
19819 {
19824 {
19827 }
19828 }
19830 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19831 to function or pointer to member function argument if the set of
19832 overloaded functions does not contain function templates and at most
19833 one of a set of overloaded functions provides a unique match.
19835 So if we found multiple possibilities, we return success but don't
19836 deduce anything. */
19839 {
19843 {
19848 /* Don't forget explicit template arguments in a pack. */
19852 }
19853 }
19858 }
19860 /* Core DR 115: In contexts where deduction is done and fails, or in
19861 contexts where deduction is not done, if a template argument list is
19862 specified and it, along with any default template arguments, identifies
19863 a single function template specialization, then the template-id is an
19864 lvalue for the function template specialization. */
19866 tree
19868 {
19881 {
19884 }
19886 {
19889 }
19891 {
19894 }
19897 {
19901 /* If we got some explicit template args, we need to plug them into
19902 the affected templates before we try to unify, in case the
19903 explicit args will completely resolve the templates in question. */
19911 {
19924 {
19927 {
19930 }
19932 {
19935 }
19936 }
19937 }
19939 {
19947 {
19948 tree base
19951 }
19955 }
19957 /* There were no good options and at least one bad one, so let the
19958 user know what the problem is. */
19960 }
19962 }
19964 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19965 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19966 different overloads deduce different arguments for a given parm.
19967 ADDR_P is true if the expression for which deduction is being
19968 performed was of the form "& fn" rather than simply "fn".
19970 Returns 1 on success. */
19972 static int
19974 tree orig_targs,
19975 tree targs,
19976 tree parm,
19977 tree arg,
19978 unification_kind_t strict,
19982 {
19984 tree tempargs;
19990 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19991 to function or pointer to member function argument if the set of
19992 overloaded functions does not contain function templates and at most
19993 one of a set of overloaded functions provides a unique match.
19995 So if this is a template, just return success. */
20007 /* We don't copy orig_targs for this because if we have already deduced
20008 some template args from previous args, unify would complain when we
20009 try to deduce a template parameter for the same argument, even though
20010 there isn't really a conflict. */
20017 /* First make sure we didn't deduce anything that conflicts with
20018 explicitly specified args. */
20020 {
20027 /* Since we're unifying against ourselves, we will fill in
20028 template args used in the function parm list with our own
20029 template parms. Discard them. */
20032 {
20033 /* Check that the argument at each index of the deduced argument pack
20034 is equivalent to the corresponding explicitly specified argument.
20035 We may have deduced more arguments than were explicitly specified,
20036 and that's OK. */
20038 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
20039 that's wrong if we deduce the same argument pack from multiple
20040 function arguments: it's only incomplete the first time. */
20053 }
20056 }
20059 {
20064 }
20067 }
20069 /* PARM is a template class (perhaps with unbound template
20070 parameters). ARG is a fully instantiated type. If ARG can be
20071 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20072 TARGS are as for unify. */
20074 static tree
20077 {
20078 tree copy_of_targs;
20088 /* We need to make a new template argument vector for the call to
20089 unify. If we used TARGS, we'd clutter it up with the result of
20090 the attempted unification, even if this class didn't work out.
20091 We also don't want to commit ourselves to all the unifications
20092 we've already done, since unification is supposed to be done on
20093 an argument-by-argument basis. In other words, consider the
20094 following pathological case:
20096 template <int I, int J, int K>
20097 struct S {};
20099 template <int I, int J>
20100 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20102 template <int I, int J, int K>
20103 void f(S<I, J, K>, S<I, I, I>);
20105 void g() {
20106 S<0, 0, 0> s0;
20107 S<0, 1, 2> s2;
20109 f(s0, s2);
20110 }
20112 Now, by the time we consider the unification involving `s2', we
20113 already know that we must have `f<0, 0, 0>'. But, even though
20114 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20115 because there are two ways to unify base classes of S<0, 1, 2>
20116 with S<I, I, I>. If we kept the already deduced knowledge, we
20117 would reject the possibility I=1. */
20121 {
20125 }
20127 /* If unification failed, we're done. */
20133 }
20135 /* Given a template type PARM and a class type ARG, find the unique
20136 base type in ARG that is an instance of PARM. We do not examine
20137 ARG itself; only its base-classes. If there is not exactly one
20138 appropriate base class, return NULL_TREE. PARM may be the type of
20139 a partial specialization, as well as a plain template type. Used
20140 by unify. */
20142 static enum template_base_result
20145 {
20147 tree binfo;
20153 {
20154 /* The type could not be completed. */
20157 }
20159 /* Walk in inheritance graph order. The search order is not
20160 important, and this avoids multiple walks of virtual bases. */
20162 {
20167 {
20168 /* If there is more than one satisfactory baseclass, then:
20170 [temp.deduct.call]
20172 If they yield more than one possible deduced A, the type
20173 deduction fails.
20175 applies. */
20177 {
20180 }
20183 }
20184 }
20188 }
20190 /* Returns the level of DECL, which declares a template parameter. */
20192 static int
20194 {
20196 {
20206 }
20208 }
20210 /* Decide whether ARG can be unified with PARM, considering only the
20211 cv-qualifiers of each type, given STRICT as documented for unify.
20212 Returns nonzero iff the unification is OK on that basis. */
20214 static int
20216 {
20222 {
20223 /* Although a CVR qualifier is ignored when being applied to a
20224 substituted template parameter ([8.3.2]/1 for example), that
20225 does not allow us to unify "const T" with "int&" because both
20226 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20227 It is ok when we're allowing additional CV qualifiers
20228 at the outer level [14.8.2.1]/3,1st bullet. */
20238 }
20249 }
20251 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20252 void
20254 {
20258 {
20261 }
20262 else
20263 {
20266 }
20267 }
20269 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20270 do { \
20271 if (unify (TP, TA, P, A, S, EP)) \
20272 return 1; \
20273 } while (0)
20275 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20276 expansion at the end of PACKED_PARMS. Returns 0 if the type
20277 deduction succeeds, 1 otherwise. STRICT is the same as in
20278 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20279 function call argument list. We'll need to adjust the arguments to make them
20280 types. SUBR tells us if this is from a recursive call to
20281 type_unification_real, or for comparing two template argument
20282 lists. */
20284 static int
20288 {
20289 tree parm
20295 /* Add in any args remembered from an earlier partial instantiation. */
20302 /* Determine the parameter packs we will be deducing from the
20303 pattern, and record their current deductions. */
20306 {
20310 /* Determine the index and level of this parameter pack. */
20313 /* Keep track of the parameter packs and their corresponding
20314 argument packs. */
20317 }
20319 /* Loop through all of the arguments that have not yet been
20320 unified and unify each with the pattern. */
20322 {
20323 tree parm;
20327 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20328 or the element of its argument pack at the current index if
20329 this argument was explicitly specified. */
20331 {
20340 {
20343 }
20345 }
20347 /* If we had explicit template arguments, substitute them into the
20348 pattern before deduction. */
20350 {
20351 /* Some arguments might still be unspecified or dependent. */
20359 NULL_TREE);
20364 }
20365 else
20368 /* Unify the pattern with the current argument. */
20370 explain_p))
20373 /* For each parameter pack, collect the deduced value. */
20375 {
20381 }
20382 }
20384 /* Verify that the results of unification with the parameter packs
20385 produce results consistent with what we've seen before, and make
20386 the deduced argument packs available. */
20388 {
20395 /* By default keep the original deduced argument pack.
20396 If necessary, more specific code is going to update the
20397 resulting deduced argument later down in this function. */
20401 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20402 actually deduce anything. */
20410 {
20411 /* If we had fewer function args than explicit template args,
20412 just use the explicits. */
20417 }
20420 {
20421 tree result;
20422 /* Build the deduced *_ARGUMENT_PACK. */
20424 {
20427 }
20428 else
20433 /* Note the deduced argument packs for this parameter
20434 pack. */
20436 }
20440 {
20441 /* We only had the explicitly-provided arguments before, but
20442 now we have a complete set of arguments. */
20448 }
20449 else
20450 {
20456 /* Inconsistent unification of this parameter pack. */
20458 bad_old_arg,
20459 bad_new_arg);
20460 }
20461 }
20464 }
20466 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20467 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20468 parameters and return value are as for unify. */
20470 static int
20474 {
20475 tree parm_max;
20476 tree arg_max;
20480 /* Our representation of array types uses "N - 1" as the
20481 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20482 not an integer constant. We cannot unify arbitrarily
20483 complex expressions, so we eliminate the MINUS_EXPRs
20484 here. */
20488 {
20491 }
20495 {
20496 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20497 trying to unify the type of a variable with the type
20498 of a template parameter. For example:
20500 template <unsigned int N>
20501 void f (char (&) [N]);
20502 int g();
20503 void h(int i) {
20504 char a[g(i)];
20505 f(a);
20506 }
20508 Here, the type of the ARG will be "int [g(i)]", and
20509 may be a SAVE_EXPR, etc. */
20513 }
20515 /* If only one of the bounds used a MINUS_EXPR, compensate
20516 by adding one to the other bound. */
20519 integer_type_node,
20520 parm_max,
20521 integer_one_node);
20524 integer_type_node,
20525 arg_max,
20526 integer_one_node);
20530 }
20532 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20536 static pa_kind_t
20538 {
20547 else
20549 }
20551 /* Deduce the value of template parameters. TPARMS is the (innermost)
20552 set of template parameters to a template. TARGS is the bindings
20553 for those template parameters, as determined thus far; TARGS may
20554 include template arguments for outer levels of template parameters
20555 as well. PARM is a parameter to a template function, or a
20556 subcomponent of that parameter; ARG is the corresponding argument.
20557 This function attempts to match PARM with ARG in a manner
20558 consistent with the existing assignments in TARGS. If more values
20559 are deduced, then TARGS is updated.
20561 Returns 0 if the type deduction succeeds, 1 otherwise. The
20562 parameter STRICT is a bitwise or of the following flags:
20564 UNIFY_ALLOW_NONE:
20565 Require an exact match between PARM and ARG.
20566 UNIFY_ALLOW_MORE_CV_QUAL:
20567 Allow the deduced ARG to be more cv-qualified (by qualification
20568 conversion) than ARG.
20569 UNIFY_ALLOW_LESS_CV_QUAL:
20570 Allow the deduced ARG to be less cv-qualified than ARG.
20571 UNIFY_ALLOW_DERIVED:
20572 Allow the deduced ARG to be a template base class of ARG,
20573 or a pointer to a template base class of the type pointed to by
20574 ARG.
20575 UNIFY_ALLOW_INTEGER:
20576 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20577 case for more information.
20578 UNIFY_ALLOW_OUTER_LEVEL:
20579 This is the outermost level of a deduction. Used to determine validity
20580 of qualification conversions. A valid qualification conversion must
20581 have const qualified pointers leading up to the inner type which
20582 requires additional CV quals, except at the outer level, where const
20583 is not required [conv.qual]. It would be normal to set this flag in
20584 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20585 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20586 This is the outermost level of a deduction, and PARM can be more CV
20587 qualified at this point.
20588 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20589 This is the outermost level of a deduction, and PARM can be less CV
20590 qualified at this point. */
20592 static int
20595 {
20597 tree targ;
20598 tree tparm;
20600 tsubst_flags_t complain = (explain_p
20601 ? tf_warning_or_error
20604 /* I don't think this will do the right thing with respect to types.
20605 But the only case I've seen it in so far has been array bounds, where
20606 signedness is the only information lost, and I think that will be
20607 okay. */
20615 /* We can't deduce anything from this, but we might get all the
20616 template args from other function args. */
20622 /* If PARM uses template parameters, then we can't bail out here,
20623 even if ARG == PARM, since we won't record unifications for the
20624 template parameters. We might need them if we're trying to
20625 figure out which of two things is more specialized. */
20629 /* Handle init lists early, so the rest of the function can assume
20630 we're dealing with a type. */
20632 {
20637 /* Replace T with std::initializer_list<T> for deduction. */
20644 /* We can only deduce from an initializer list argument if the
20645 parameter is std::initializer_list or an array; otherwise this
20646 is a non-deduced context. */
20651 else
20652 {
20654 /* Deduction is defined in terms of a single type, so just punt
20655 on the (bizarre) std::initializer_list<T...>. */
20658 }
20661 {
20668 {
20672 /* It should only be possible to get here for a call. */
20674 elt_strict |= maybe_adjust_types_for_deduction
20677 }
20680 explain_p);
20681 }
20685 {
20686 /* Also deduce from the length of the initializer list. */
20693 }
20695 /* If the std::initializer_list<T> deduction worked, replace the
20696 deduced A with std::initializer_list<A>. */
20698 {
20703 }
20705 }
20707 /* If parm and arg aren't the same kind of thing (template, type, or
20708 expression), fail early. */
20712 /* Immediately reject some pairs that won't unify because of
20713 cv-qualification mismatches. */
20716 /* It is the elements of the array which hold the cv quals of an array
20717 type, and the elements might be template type parms. We'll check
20718 when we recurse. */
20720 /* We check the cv-qualifiers when unifying with template type
20721 parameters below. We want to allow ARG `const T' to unify with
20722 PARM `T' for example, when computing which of two templates
20723 is more specialized, for example. */
20737 {
20741 /* In a type which contains a nested-name-specifier, template
20742 argument values cannot be deduced for template parameters used
20743 within the nested-name-specifier. */
20755 /* The PARM is not one we're trying to unify. Just check
20756 to see if it matches ARG. */
20757 {
20762 else
20764 }
20771 /* Check for mixed types and values. */
20779 {
20782 {
20783 /* First try to match ARG directly. */
20785 explain_p);
20787 {
20788 /* Otherwise, look for a suitable base of ARG, as below. */
20795 }
20796 }
20797 /* ARG must be constructed from a template class or a template
20798 template parameter. */
20803 /* Deduce arguments T, i from TT<T> or TT<i>. */
20809 /* Fall through to deduce template name. */
20810 }
20814 {
20815 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20817 /* Simple cases: Value already set, does match or doesn't. */
20822 }
20823 else
20824 {
20825 /* If PARM is `const T' and ARG is only `int', we don't have
20826 a match unless we are allowing additional qualification.
20827 If ARG is `const int' and PARM is just `T' that's OK;
20828 that binds `const int' to `T'. */
20833 /* Consider the case where ARG is `const volatile int' and
20834 PARM is `const T'. Then, T should be `volatile int'. */
20835 arg = cp_build_qualified_type_real
20840 /* Simple cases: Value already set, does match or doesn't. */
20846 /* Make sure that ARG is not a variable-sized array. (Note
20847 that were talking about variable-sized arrays (like
20848 `int[n]'), rather than arrays of unknown size (like
20849 `int[]').) We'll get very confused by such a type since
20850 the bound of the array is not constant, and therefore
20851 not mangleable. Besides, such types are not allowed in
20852 ISO C++, so we can do as we please here. We do allow
20853 them for 'auto' deduction, since that isn't ABI-exposed. */
20857 /* Strip typedefs as in convert_template_argument. */
20859 }
20861 /* If ARG is a parameter pack or an expansion, we cannot unify
20862 against it unless PARM is also a parameter pack. */
20867 /* If the argument deduction results is a METHOD_TYPE,
20868 then there is a problem.
20869 METHOD_TYPE doesn't map to any real C++ type the result of
20870 the deduction can not be of that type. */
20884 {
20885 /* The PARM is not one we're trying to unify. Just check
20886 to see if it matches ARG. */
20892 }
20898 {
20903 }
20905 /* [temp.deduct.type] If, in the declaration of a function template
20906 with a non-type template-parameter, the non-type
20907 template-parameter is used in an expression in the function
20908 parameter-list and, if the corresponding template-argument is
20909 deduced, the template-argument type shall match the type of the
20910 template-parameter exactly, except that a template-argument
20911 deduced from an array bound may be of any integral type.
20912 The non-type parameter might use already deduced type parameters. */
20915 {
20919 }
20922 /* Template-parameter dependent expression. Just accept it for now.
20923 It will later be processed in convert_template_argument. */
20924 ;
20930 /* Convert the ARG to the type of PARM; the deduced non-type
20931 template argument must exactly match the types of the
20932 corresponding parameter. */
20935 {
20936 /* We haven't deduced the type of this parameter yet. */
20938 /* We deduce from array bounds in try_array_deduction. */
20940 {
20941 /* Deduce it from the non-type argument. */
20946 }
20947 else
20948 /* Try again later. */
20950 }
20951 else
20954 /* If ARG is a parameter pack or an expansion, we cannot unify
20955 against it unless PARM is also a parameter pack. */
20960 {
20963 }
20968 {
20969 /* A pointer-to-member constant can be unified only with
20970 another constant. */
20974 /* Just unify the class member. It would be useless (and possibly
20975 wrong, depending on the strict flags) to unify also
20976 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20977 arg refer to the same variable, even if through different
20978 classes. For instance:
20980 struct A { int x; };
20981 struct B : A { };
20983 Unification of &A::x and &B::x must succeed. */
20986 }
20989 {
20993 /* [temp.deduct.call]
20995 A can be another pointer or pointer to member type that can
20996 be converted to the deduced A via a qualification
20997 conversion (_conv.qual_).
20999 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
21000 This will allow for additional cv-qualification of the
21001 pointed-to types if appropriate. */
21004 /* The derived-to-base conversion only persists through one
21005 level of pointers. */
21010 }
21042 /* We have already checked cv-qualification at the top of the
21043 function. */
21047 /* As far as unification is concerned, this wins. Later checks
21048 will invalidate it if necessary. */
21051 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21052 /* Type INTEGER_CST can come from ordinary constant template args. */
21064 {
21074 /* Check for pack expansions in the parameters. */
21076 {
21078 {
21080 /* We can unify against something with a trailing
21081 parameter pack. */
21083 else
21084 /* [temp.deduct.type]/9: If the template argument list of
21085 P contains a pack expansion that is not the last
21086 template argument, the entire template argument list
21087 is a non-deduced context. */
21089 }
21090 }
21092 /* If we don't have enough arguments to satisfy the parameters
21093 (not counting the pack expression at the end), or we have
21094 too many arguments for a parameter list that doesn't end in
21095 a pack expression, we can't unify. */
21101 /* Unify all of the parameters that precede the (optional)
21102 pack expression. */
21104 {
21109 }
21112 DEDUCE_EXACT,
21115 }
21123 {
21131 }
21136 {
21140 {
21141 /* First, we try to unify the PARM and ARG directly. */
21146 {
21147 /* Fallback to the special case allowed in
21148 [temp.deduct.call]:
21150 If P is a class, and P has the form
21151 template-id, then A can be a derived class of
21152 the deduced A. Likewise, if P is a pointer to
21153 a class of the form template-id, A can be a
21154 pointer to a derived class pointed to by the
21155 deduced A. */
21161 {
21162 /* Don't give the derived diagnostic if we're
21163 already dealing with the same template. */
21164 bool same_template
21170 }
21171 }
21172 }
21176 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21177 Then, we should unify `int' and `U'. */
21179 else
21180 /* There's no chance of unification succeeding. */
21185 }
21192 {
21195 tree a;
21201 /* CV qualifications for methods can never be deduced, they must
21202 match exactly. We need to check them explicitly here,
21203 because type_unification_real treats them as any other
21204 cv-qualified parameter. */
21206 && (!check_cv_quals_for_unify
21234 {
21246 }
21249 }
21252 /* Unify a pointer to member with a pointer to member function, which
21253 deduces the type of the member as a function type. */
21255 {
21256 /* Check top-level cv qualifiers */
21264 /* Determine the type of the function we are unifying against. */
21268 }
21287 /* Matched cases are handled by the ARG == PARM test above. */
21291 /* We might get a variable as a non-type template argument in parm if the
21292 corresponding parameter is type-dependent. Make any necessary
21293 adjustments based on whether arg is a reference. */
21297 {
21302 }
21303 /* Now use the normal expression code to check whether they match. */
21314 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21315 or UNDERLYING_TYPE nodes. */
21319 /* Unification fails if we hit an error node. */
21324 {
21334 }
21335 /* FALLTHRU */
21338 /* An unresolved overload is a nondeduced context. */
21342 expr:
21343 /* We must be looking at an expression. This can happen with
21344 something like:
21346 template <int I>
21347 void foo(S<I>, S<I + 2>);
21349 This is a "nondeduced context":
21351 [deduct.type]
21353 The nondeduced contexts are:
21355 --A type that is a template-id in which one or more of
21356 the template-arguments is an expression that references
21357 a template-parameter.
21359 In these cases, we assume deduction succeeded, but don't
21360 actually infer any unifications. */
21365 else
21367 }
21368 }
21369 #undef RECUR_AND_CHECK_FAILURE
21370 \f
21371 /* Note that DECL can be defined in this translation unit, if
21372 required. */
21374 static void
21376 {
21377 tree clone;
21381 }
21383 /* Called if RESULT is explicitly instantiated, or is a member of an
21384 explicitly instantiated class. */
21386 void
21388 {
21391 /* If this entity has already been written out, it's too late to
21392 make any modifications. */
21396 /* For anonymous namespace we don't need to do anything. */
21398 {
21401 }
21404 /* The TREE_PUBLIC flag for function declarations will have been
21405 set correctly by tsubst. */
21408 /* This might have been set by an earlier implicit instantiation. */
21413 else
21414 {
21417 /* Always make artificials weak. */
21420 /* For WIN32 we also want to put explicit instantiations in
21421 linkonce sections. */
21424 }
21426 /* If EXTERN_P, then this function will not be emitted -- unless
21427 followed by an explicit instantiation, at which point its linkage
21428 will be adjusted. If !EXTERN_P, then this function will be
21429 emitted here. In neither circumstance do we want
21430 import_export_decl to adjust the linkage. */
21432 }
21434 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21435 important template arguments. If any are missing, we check whether
21436 they're important by using error_mark_node for substituting into any
21437 args that were used for partial ordering (the ones between ARGS and END)
21438 and seeing if it bubbles up. */
21440 static bool
21442 {
21447 {
21450 }
21452 {
21456 }
21458 }
21460 /* Given two function templates PAT1 and PAT2, return:
21462 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21463 -1 if PAT2 is more specialized than PAT1.
21464 0 if neither is more specialized.
21466 LEN indicates the number of parameters we should consider
21467 (defaulted parameters should not be considered).
21469 The 1998 std underspecified function template partial ordering, and
21470 DR214 addresses the issue. We take pairs of arguments, one from
21471 each of the templates, and deduce them against each other. One of
21472 the templates will be more specialized if all the *other*
21473 template's arguments deduce against its arguments and at least one
21474 of its arguments *does* *not* deduce against the other template's
21475 corresponding argument. Deduction is done as for class templates.
21476 The arguments used in deduction have reference and top level cv
21477 qualifiers removed. Iff both arguments were originally reference
21478 types *and* deduction succeeds in both directions, an lvalue reference
21479 wins against an rvalue reference and otherwise the template
21480 with the more cv-qualified argument wins for that pairing (if
21481 neither is more cv-qualified, they both are equal). Unlike regular
21482 deduction, after all the arguments have been deduced in this way,
21483 we do *not* verify the deduced template argument values can be
21484 substituted into non-deduced contexts.
21486 The logic can be a bit confusing here, because we look at deduce1 and
21487 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21488 can find template arguments for pat1 to make arg1 look like arg2, that
21489 means that arg2 is at least as specialized as arg1. */
21491 int
21493 {
21506 /* Remove the this parameter from non-static member functions. If
21507 one is a non-static member function and the other is not a static
21508 member function, remove the first parameter from that function
21509 also. This situation occurs for operator functions where we
21510 locate both a member function (with this pointer) and non-member
21511 operator (with explicit first operand). */
21513 {
21518 }
21520 {
21523 {
21524 len--;
21526 }
21527 }
21529 /* If only one is a conversion operator, they are unordered. */
21533 /* Consider the return type for a conversion function */
21535 {
21538 len++;
21539 }
21541 processing_template_decl++;
21547 /* Stop when an ellipsis is seen. */
21549 {
21560 {
21561 /* When both arguments are pack expansions, we need only
21562 unify the patterns themselves. */
21566 /* This is the last comparison we need to do. */
21568 }
21570 /* DR 1847: If a particular P contains no template-parameters that
21571 participate in template argument deduction, that P is not used to
21572 determine the ordering. */
21578 {
21582 }
21585 {
21589 }
21595 {
21601 /* Setup the parameter vector, which contains only ARG1. */
21604 /* Setup the argument vector, which contains the remaining
21605 arguments. */
21614 /* We cannot deduce in the other direction, because ARG1 is
21615 a pack expansion but ARG2 is not. */
21617 }
21619 {
21625 /* Setup the parameter vector, which contains only ARG1. */
21628 /* Setup the argument vector, which contains the remaining
21629 arguments. */
21638 /* We cannot deduce in the other direction, because ARG2 is
21639 a pack expansion but ARG1 is not.*/
21641 }
21643 else
21644 {
21645 /* The normal case, where neither argument is a pack
21646 expansion. */
21653 }
21655 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21656 arg2, then arg2 is not as specialized as arg1. */
21662 /* "If, for a given type, deduction succeeds in both directions
21663 (i.e., the types are identical after the transformations above)
21664 and both P and A were reference types (before being replaced with
21665 the type referred to above):
21666 - if the type from the argument template was an lvalue reference and
21667 the type from the parameter template was not, the argument type is
21668 considered to be more specialized than the other; otherwise,
21669 - if the type from the argument template is more cv-qualified
21670 than the type from the parameter template (as described above),
21671 the argument type is considered to be more specialized than the other;
21672 otherwise,
21673 - neither type is more specialized than the other." */
21676 {
21678 {
21681 else
21683 }
21685 {
21690 }
21691 }
21694 /* We've failed to deduce something in either direction.
21695 These must be unordered. */
21698 next:
21702 /* We have already processed all of the arguments in our
21703 handing of the pack expansion type. */
21708 }
21710 /* "In most cases, all template parameters must have values in order for
21711 deduction to succeed, but for partial ordering purposes a template
21712 parameter may remain without a value provided it is not used in the
21713 types being used for partial ordering."
21715 Thus, if we are missing any of the targs1 we need to substitute into
21716 origs1, then pat2 is not as specialized as pat1. This can happen when
21717 there is a nondeduced context. */
21723 processing_template_decl--;
21725 /* If both deductions succeed, the partial ordering selects the more
21726 constrained template. */
21728 {
21733 }
21735 /* All things being equal, if the next argument is a pack expansion
21736 for one function but not for the other, prefer the
21737 non-variadic function. FIXME this is bogus; see c++/41958. */
21741 {
21744 }
21750 else
21752 }
21754 /* Determine which of two partial specializations of TMPL is more
21755 specialized.
21757 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21758 to the first partial specialization. The TREE_PURPOSE is the
21759 innermost set of template parameters for the partial
21760 specialization. PAT2 is similar, but for the second template.
21762 Return 1 if the first partial specialization is more specialized;
21763 -1 if the second is more specialized; 0 if neither is more
21764 specialized.
21766 See [temp.class.order] for information about determining which of
21767 two templates is more specialized. */
21769 static int
21771 {
21772 tree targs;
21781 /* Just like what happens for functions, if we are ordering between
21782 different template specializations, we may encounter dependent
21783 types in the arguments, and we need our dependency check functions
21784 to behave correctly. */
21788 {
21791 }
21795 {
21798 }
21801 /* If both deductions succeed, the partial ordering selects the more
21802 constrained template. */
21806 /* In the case of a tie where at least one of the templates
21807 has a parameter pack at the end, the template with the most
21808 non-packed parameters wins. */
21810 && any_deductions
21813 {
21819 /* We don't count the pack expansion at the end. */
21829 }
21832 }
21834 /* Return the template arguments that will produce the function signature
21835 DECL from the function template FN, with the explicit template
21836 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21837 also match. Return NULL_TREE if no satisfactory arguments could be
21838 found. */
21840 static tree
21842 {
21846 tree decl_arg_types;
21849 tree arg;
21853 /* Never do unification on the 'this' parameter. */
21874 }
21876 /* Return the innermost template arguments that, when applied to a partial
21877 specialization SPEC_TMPL of TMPL, yield the ARGS.
21879 For example, suppose we have:
21881 template <class T, class U> struct S {};
21882 template <class T> struct S<T*, int> {};
21884 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21885 partial specialization and the ARGS will be {double*, int}. The resulting
21886 vector will be {double}, indicating that `T' is bound to `double'. */
21888 static tree
21890 {
21892 tree spec_args
21895 tree deduced_args;
21896 tree innermost_deduced_args;
21900 {
21904 innermost_deduced_args);
21905 }
21906 else
21910 again:
21919 {
21921 {
21927 }
21929 }
21933 {
21936 }
21938 /* Verify that nondeduced template arguments agree with the type
21939 obtained from argument deduction.
21941 For example:
21943 struct A { typedef int X; };
21944 template <class T, class U> struct C {};
21945 template <class T> struct C<T, typename T::X> {};
21947 Then with the instantiation `C<A, int>', we can deduce that
21948 `T' is `A' but unify () does not check whether `typename T::X'
21949 is `int'. */
21960 /* We only need to check the innermost arguments; the other
21961 arguments will always agree. */
21966 /* Now that we have bindings for all of the template arguments,
21967 ensure that the arguments deduced for the template template
21968 parameters have compatible template parameter lists. See the use
21969 of template_template_parm_bindings_ok_p in fn_type_unification
21970 for more information. */
21975 }
21977 // Compare two function templates T1 and T2 by deducing bindings
21978 // from one against the other. If both deductions succeed, compare
21979 // constraints to see which is more constrained.
21980 static int
21982 {
21987 {
21990 }
21993 {
21996 }
21998 // If both deductions succeed, then one may be more constrained.
22003 }
22005 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
22006 Return the TREE_LIST node with the most specialized template, if
22007 any. If there is no most specialized template, the error_mark_node
22008 is returned.
22010 Note that this function does not look at, or modify, the
22011 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
22012 returned is one of the elements of INSTANTIATIONS, callers may
22013 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
22014 and retrieve it from the value returned. */
22016 tree
22018 {
22025 {
22031 {
22032 /* Equally specialized, move to next function. If there
22033 is no next function, nothing's most specialized. */
22038 }
22039 }
22042 /* Now verify that champ is better than everything earlier in the
22043 instantiation list. */
22046 {
22049 }
22050 }
22052 processing_template_decl--;
22058 }
22060 /* If DECL is a specialization of some template, return the most
22061 general such template. Otherwise, returns NULL_TREE.
22063 For example, given:
22065 template <class T> struct S { template <class U> void f(U); };
22067 if TMPL is `template <class U> void S<int>::f(U)' this will return
22068 the full template. This function will not trace past partial
22069 specializations, however. For example, given in addition:
22071 template <class T> struct S<T*> { template <class U> void f(U); };
22073 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22074 `template <class T> template <class U> S<T*>::f(U)'. */
22076 tree
22078 {
22080 {
22083 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22084 template friend, or a FIELD_DECL for a capture pack. */
22087 }
22089 /* Look for more and more general templates. */
22091 {
22092 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22093 (See cp-tree.h for details.) */
22102 /* Stop if we run into an explicitly specialized class template. */
22109 }
22112 }
22114 /* Return the most specialized of the template partial specializations
22115 which can produce TARGET, a specialization of some class or variable
22116 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22117 a TEMPLATE_DECL node corresponding to the partial specialization, while
22118 the TREE_PURPOSE is the set of template arguments that must be
22119 substituted into the template pattern in order to generate TARGET.
22121 If the choice of partial specialization is ambiguous, a diagnostic
22122 is issued, and the error_mark_node is returned. If there are no
22123 partial specializations matching TARGET, then NULL_TREE is
22124 returned, indicating that the primary template should be used. */
22126 static tree
22128 {
22130 tree t;
22131 tree champ;
22138 {
22142 }
22144 {
22147 }
22149 {
22153 }
22154 else
22159 /* For determining which partial specialization to use, only the
22160 innermost args are interesting. */
22162 {
22165 }
22168 {
22169 tree spec_args;
22173 {
22174 /* Substitute in the template args from the enclosing class. */
22178 }
22185 {
22189 /* Keep the candidate only if the constraints are satisfied,
22190 or if we're not compiling with concepts. */
22193 {
22196 }
22197 }
22198 }
22208 {
22211 ;
22212 else
22213 {
22215 {
22218 {
22221 }
22222 }
22224 }
22225 }
22229 {
22232 {
22235 }
22236 }
22239 {
22246 else
22250 {
22255 }
22258 }
22261 }
22263 /* Explicitly instantiate DECL. */
22265 void
22267 {
22272 /* An error occurred, for which grokdeclarator has already issued
22273 an appropriate message. */
22276 {
22279 }
22285 {
22286 /* There is an asymmetry here in the way VAR_DECLs and
22287 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22288 the latter, the DECL we get back will be marked as a
22289 template instantiation, and the appropriate
22290 DECL_TEMPLATE_INFO will be set up. This does not happen for
22291 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22292 should handle VAR_DECLs as it currently handles
22293 FUNCTION_DECLs. */
22295 {
22298 }
22301 {
22304 }
22306 {
22311 }
22312 }
22314 {
22317 }
22318 else
22321 /* Check for various error cases. Note that if the explicit
22322 instantiation is valid the RESULT will currently be marked as an
22323 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22324 until we get here. */
22327 {
22328 /* DR 259 [temp.spec].
22330 Both an explicit instantiation and a declaration of an explicit
22331 specialization shall not appear in a program unless the explicit
22332 instantiation follows a declaration of the explicit specialization.
22334 For a given set of template parameters, if an explicit
22335 instantiation of a template appears after a declaration of an
22336 explicit specialization for that template, the explicit
22337 instantiation has no effect. */
22339 }
22341 {
22342 /* [temp.spec]
22344 No program shall explicitly instantiate any template more
22345 than once.
22347 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22348 the first instantiation was `extern' and the second is not,
22349 and EXTERN_P for the opposite case. */
22352 /* If an "extern" explicit instantiation follows an ordinary
22353 explicit instantiation, the template is instantiated. */
22356 }
22358 {
22361 }
22363 {
22366 }
22369 ;
22371 {
22374 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22377 }
22378 else
22386 }
22388 static void
22390 {
22396 {
22399 }
22400 }
22402 /* Called from do_type_instantiation through binding_table_foreach to
22403 do recursive instantiation for the type bound in ENTRY. */
22404 static void
22406 {
22412 }
22414 /* Perform an explicit instantiation of template class T. STORAGE, if
22415 non-null, is the RID for extern, inline or static. COMPLAIN is
22416 nonzero if this is called from the parser, zero if called recursively,
22417 since the standard is unclear (as detailed below). */
22419 void
22421 {
22431 {
22432 tree tmpl =
22436 else
22439 }
22444 {
22447 t);
22449 }
22452 {
22454 {
22456 {
22459 "ISO C++ 1998 forbids the use of %<extern%> on "
22461 }
22462 else
22464 "ISO C++ forbids the use of %qE"
22466 }
22474 else
22475 {
22477 storage);
22479 }
22480 }
22483 {
22484 /* DR 259 [temp.spec].
22486 Both an explicit instantiation and a declaration of an explicit
22487 specialization shall not appear in a program unless the explicit
22488 instantiation follows a declaration of the explicit specialization.
22490 For a given set of template parameters, if an explicit
22491 instantiation of a template appears after a declaration of an
22492 explicit specialization for that template, the explicit
22493 instantiation has no effect. */
22495 }
22497 {
22498 /* [temp.spec]
22500 No program shall explicitly instantiate any template more
22501 than once.
22503 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22504 instantiation was `extern'. If EXTERN_P then the second is.
22505 These cases are OK. */
22512 /* If we've already instantiated the template, just return now. */
22515 }
22523 /* In contrast to implicit instantiation, where only the
22524 declarations, and not the definitions, of members are
22525 instantiated, we have here:
22527 [temp.explicit]
22529 The explicit instantiation of a class template specialization
22530 implies the instantiation of all of its members not
22531 previously explicitly specialized in the translation unit
22532 containing the explicit instantiation.
22534 Of course, we can't instantiate member template classes, since we
22535 don't have any arguments for them. Note that the standard is
22536 unclear on whether the instantiation of the members are
22537 *explicit* instantiations or not. However, the most natural
22538 interpretation is that it should be an explicit
22539 instantiation. */
22543 && !static_p
22546 {
22551 }
22556 }
22558 /* Given a function DECL, which is a specialization of TMPL, modify
22559 DECL to be a re-instantiation of TMPL with the same template
22560 arguments. TMPL should be the template into which tsubst'ing
22561 should occur for DECL, not the most general template.
22563 One reason for doing this is a scenario like this:
22565 template <class T>
22566 void f(const T&, int i);
22568 void g() { f(3, 7); }
22570 template <class T>
22571 void f(const T& t, const int i) { }
22573 Note that when the template is first instantiated, with
22574 instantiate_template, the resulting DECL will have no name for the
22575 first parameter, and the wrong type for the second. So, when we go
22576 to instantiate the DECL, we regenerate it. */
22578 static void
22580 {
22581 /* The arguments used to instantiate DECL, from the most general
22582 template. */
22583 tree code_pattern;
22587 /* Make sure that we can see identifiers, and compute access
22588 correctly. */
22592 {
22593 tree decl_parm;
22594 tree pattern_parm;
22595 tree specs;
22609 specs);
22611 /* Merge parameter declarations. */
22614 pattern_parm
22618 {
22619 tree parm_type;
22620 tree attributes;
22625 NULL_TREE);
22631 {
22634 }
22637 }
22638 /* Merge any parameters that match with the function parameter
22639 pack. */
22641 {
22643 tree expanded_types;
22644 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22645 the parameters in this function parameter pack. */
22650 {
22651 tree parm_type;
22652 tree attributes;
22655 /* Rename the parameter to include the index. */
22664 {
22667 }
22669 }
22670 }
22671 /* Merge additional specifiers from the CODE_PATTERN. */
22675 }
22677 {
22687 }
22688 else
22692 }
22694 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22695 substituted to get DECL. */
22697 tree
22699 {
22702 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22703 for the instantiation. This is not always the most general
22704 template. Consider, for example:
22706 template <class T>
22707 struct S { template <class U> void f();
22708 template <> void f<int>(); };
22710 and an instantiation of S<double>::f<int>. We want TD to be the
22711 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22713 more general template. */
22715 /* We must also deal with friend templates. Given:
22717 template <class T> struct S {
22718 template <class U> friend void f() {};
22719 };
22721 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22722 so far as the language is concerned, but that's still
22723 where we get the pattern for the instantiation from. On
22724 other hand, if the definition comes outside the class, say:
22726 template <class T> struct S {
22727 template <class U> friend void f();
22728 };
22729 template <class U> friend void f() {}
22731 we don't need to look any further. That's what the check for
22732 DECL_INITIAL is for. */
22736 {
22737 /* The present template, TD, should not be a definition. If it
22738 were a definition, we should be using it! Note that we
22739 cannot restructure the loop to just keep going until we find
22740 a template with a definition, since that might go too far if
22741 a specialization was declared, but not defined. */
22743 /* Fetch the more general template. */
22745 }
22748 }
22750 /* Returns true if we need to instantiate this template instance even if we
22751 know we aren't going to emit it. */
22753 bool
22755 {
22756 /* We always instantiate inline functions so that we can inline them. An
22757 explicit instantiation declaration prohibits implicit instantiation of
22758 non-inline functions. With high levels of optimization, we would
22759 normally inline non-inline functions -- but we're not allowed to do
22760 that for "extern template" functions. Therefore, we check
22761 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22765 /* And we need to instantiate static data members so that
22766 their initializers are available in integral constant
22767 expressions. */
22770 }
22772 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22773 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22774 error, true otherwise. */
22776 bool
22778 {
22781 /* Don't instantiate a noexcept-specification from template context. */
22796 {
22802 {
22803 /* If hash_set::add returns true, the element was already there. */
22808 fn);
22810 }
22812 {
22827 }
22828 else
22838 }
22841 {
22844 else
22846 }
22849 }
22851 /* We're starting to process the function INST, an instantiation of PATTERN;
22852 add their parameters to local_specializations. */
22854 static void
22856 {
22860 {
22864 }
22866 {
22868 {
22871 }
22872 else
22873 {
22874 /* Register the (value) argument pack as a specialization of
22875 TMPL_PARM, then move on. */
22878 }
22879 }
22881 }
22883 /* Produce the definition of D, a _DECL generated from a template. If
22884 DEFER_OK is true, then we don't have to actually do the
22885 instantiation now; we just have to do it sometime. Normally it is
22886 an error if this is an explicit instantiation but D is undefined.
22887 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22888 instantiated class template. */
22890 tree
22892 {
22894 tree gen_args;
22895 tree args;
22896 tree td;
22897 tree code_pattern;
22898 tree spec;
22899 tree gen_tmpl;
22907 /* This function should only be used to instantiate templates for
22908 functions and static member variables. */
22911 /* A concept is never instantiated. */
22914 /* Variables are never deferred; if instantiation is required, they
22915 are instantiated right away. That allows for better code in the
22916 case that an expression refers to the value of the variable --
22917 if the variable has a constant value the referring expression can
22918 take advantage of that fact. */
22922 /* Don't instantiate cloned functions. Instead, instantiate the
22923 functions they cloned. */
22931 /* D has already been instantiated or explicitly specialized, so
22932 there's nothing for us to do here.
22934 It might seem reasonable to check whether or not D is an explicit
22935 instantiation, and, if so, stop here. But when an explicit
22936 instantiation is deferred until the end of the compilation,
22937 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22938 the instantiation. */
22941 /* Check to see whether we know that this template will be
22942 instantiated in some other file, as with "extern template"
22943 extension. */
22946 /* In general, we do not instantiate such templates. */
22954 /* We should already have the extra args. */
22957 /* And what's in the hash table should match D. */
22961 /* This needs to happen before any tsubsting. */
22967 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22968 for the instantiation. */
22973 {
22974 /* Look up an explicit specialization, if any. */
22978 {
22981 }
22982 }
22986 /* We should never be trying to instantiate a member of a class
22987 template or partial specialization. */
22992 /* In the case of a friend template whose definition is provided
22993 outside the class, we may have too many arguments. Drop the
22994 ones we don't need. The same is true for specializations. */
22995 args = get_innermost_template_args
22999 {
23005 }
23006 else
23007 {
23012 else
23014 }
23016 /* We may be in the middle of deferred access check. Disable it now. */
23019 /* Unless an explicit instantiation directive has already determined
23020 the linkage of D, remember that a definition is available for
23021 this entity. */
23031 /* If D is a member of an explicitly instantiated class template,
23032 and no definition is available, treat it like an implicit
23033 instantiation. */
23036 {
23037 /* Leave linkage flags alone on instantiations with anonymous
23038 visibility. */
23040 {
23043 }
23045 }
23047 /* Defer all other templates, unless we have been explicitly
23048 forbidden from doing so. */
23050 template. */
23051 ! pattern_defined
23052 /* If it's OK to postpone instantiation, do so. */
23053 || defer_ok
23054 /* If this is a static data member that will be defined
23055 elsewhere, we don't want to instantiate the entire data
23056 member, but we do want to instantiate the initializer so that
23057 we can substitute that elsewhere. */
23059 /* Handle here a deleted function too, avoid generating
23060 its body (c++/61080). */
23062 {
23063 /* The definition of the static data member is now required so
23064 we must substitute the initializer. */
23068 {
23069 tree ns;
23070 tree init;
23079 args,
23082 /* If instantiating the initializer involved instantiating this
23083 again, don't call cp_finish_decl twice. */
23085 {
23086 /* Make sure the initializer is still constant, in case of
23087 circular dependency (template/instantiate6.C). */
23088 const_init
23092 LOOKUP_ONLYCONVERTING);
23093 }
23097 }
23099 /* We restore the source position here because it's used by
23100 add_pending_template. */
23106 /* [temp.explicit]
23108 The definition of a non-exported function template, a
23109 non-exported member function template, or a non-exported
23110 member function or static data member of a class template
23111 shall be present in every translation unit in which it is
23112 explicitly instantiated. */
23116 /* If we're in unevaluated context, we just wanted to get the
23117 constant value; this isn't an odr use, so don't queue
23118 a full instantiation. */
23121 /* ??? Historically, we have instantiated inline functions, even
23122 when marked as "extern template". */
23126 }
23127 /* Tell the repository that D is available in this translation unit
23128 -- and see if it is supposed to be instantiated here. */
23130 {
23131 /* In a PCH file, despite the fact that the repository hasn't
23132 requested instantiation in the PCH it is still possible that
23133 an instantiation will be required in a file that includes the
23134 PCH. */
23137 /* Instantiate inline functions so that the inliner can do its
23138 job, even though we'll not be emitting a copy of this
23139 function. */
23142 }
23145 tree fn_context;
23156 else
23157 {
23161 }
23163 /* Mark D as instantiated so that recursive calls to
23164 instantiate_decl do not try to instantiate it again. */
23167 /* Regenerate the declaration in case the template has been modified
23168 by a subsequent redeclaration. */
23171 /* We already set the file and line above. Reset them now in case
23172 they changed as a result of calling regenerate_decl_from_template. */
23176 {
23177 tree init;
23180 /* Clear out DECL_RTL; whatever was there before may not be right
23181 since we've reset the type of the declaration. */
23185 /* The initializer is placed in DECL_INITIAL by
23186 regenerate_decl_from_template so we don't need to
23187 push/pop_access_scope again here. Pull it out so that
23188 cp_finish_decl can process it. */
23193 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23194 initializer. That function will defer actual emission until
23195 we have a chance to determine linkage. */
23198 /* Enter the scope of D so that access-checking works correctly. */
23211 }
23215 {
23216 /* Set up the list of local specializations. */
23220 /* Set up context. */
23224 else
23227 /* Some typedefs referenced from within the template code need to be
23228 access checked at template instantiation time, i.e now. These
23229 types were added to the template at parsing time. Let's get those
23230 and perform the access checks then. */
23232 args);
23234 /* Create substitution entries for the parameters. */
23237 /* Substitute into the body of the function. */
23241 else
23242 {
23247 /* Set the current input_location to the end of the function
23248 so that finish_function knows where we are. */
23249 input_location
23252 /* Remember if we saw an infinite loop in the template. */
23253 current_function_infinite_loop
23255 }
23257 /* Finish the function. */
23261 else
23262 {
23265 }
23269 }
23271 /* We're not deferring instantiation any more. */
23276 else
23282 out:
23291 }
23293 /* Run through the list of templates that we wish we could
23294 instantiate, and instantiate any we can. RETRIES is the
23295 number of times we retry pending template instantiation. */
23297 void
23299 {
23303 /* Instantiating templates may trigger vtable generation. This in turn
23304 may require further template instantiations. We place a limit here
23305 to avoid infinite loop. */
23307 {
23311 "template instantiation depth exceeds maximum of %d"
23312 " instantiating %q+D, possibly from virtual table generation"
23316 /* Pretend that we defined it. */
23319 }
23321 do
23322 {
23327 {
23332 {
23334 {
23349 }
23352 }
23353 else
23354 {
23357 {
23358 instantiation
23364 }
23368 }
23371 /* If INSTANTIATION has been instantiated, then we don't
23372 need to consider it again in the future. */
23374 else
23375 {
23378 }
23381 }
23383 }
23387 }
23389 /* Substitute ARGVEC into T, which is a list of initializers for
23390 either base class or a non-static data member. The TREE_PURPOSEs
23391 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23392 instantiate_decl. */
23394 static tree
23396 {
23400 {
23401 tree decl;
23402 tree init;
23408 {
23409 tree expr;
23410 tree arg;
23412 /* Expand the base class expansion type into separate base
23413 classes. */
23415 tf_warning_or_error,
23416 NULL_TREE);
23420 /* We'll be building separate TREE_LISTs of arguments for
23421 each base. */
23427 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23428 expand each argument in the TREE_VALUE of t. */
23435 /* VOID_TYPE_NODE is used to indicate
23436 value-initialization. */
23437 {
23440 }
23441 else
23442 {
23443 /* Substitute parameter packs into each argument in the
23444 TREE_LIST. */
23447 {
23448 tree expanded_exprs;
23450 /* Expand the argument. */
23452 expanded_exprs
23454 tf_warning_or_error,
23455 NULL_TREE);
23459 /* Prepend each of the expanded expressions to the
23460 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23462 {
23467 }
23468 }
23471 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23472 since we built them backwards. */
23474 {
23477 }
23478 }
23479 }
23482 {
23484 {
23488 }
23489 else
23490 {
23491 tree tmp;
23506 /* If we had an initializer but it instantiated to nothing,
23507 value-initialize the object. This will only occur when
23508 the initializer was a pack expansion where the parameter
23509 packs used in that expansion were of length zero. */
23512 }
23515 {
23519 }
23520 }
23521 }
23523 }
23525 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23527 static void
23529 {
23534 else
23536 }
23538 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23539 is the instantiation (which should have been created with
23540 start_enum) and ARGS are the template arguments to use. */
23542 static void
23544 {
23545 tree e;
23551 {
23552 tree value;
23553 tree decl;
23556 /* Note that in a template enum, the TREE_VALUE is the
23557 CONST_DECL, not the corresponding INTEGER_CST. */
23562 /* Give this enumeration constant the correct access. */
23565 /* Actually build the enumerator itself. Here we're assuming that
23566 enumerators can't have dependent attributes. */
23569 }
23579 }
23581 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23582 its type -- but without substituting the innermost set of template
23583 arguments. So, innermost set of template parameters will appear in
23584 the type. */
23586 tree
23588 {
23589 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23591 }
23593 /* Return truthvalue if we're processing a template different from
23594 the last one involved in diagnostics. */
23595 bool
23597 {
23599 }
23601 /* Remember current template involved in diagnostics. */
23602 void
23604 {
23606 }
23610 {
23612 }
23614 /* Return TRUE if current_function_decl is being instantiated, false
23615 otherwise. */
23617 bool
23619 {
23622 }
23624 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23625 type. Return false for ok, true for disallowed. Issue error and
23626 inform messages under control of COMPLAIN. */
23628 static bool
23630 {
23645 /* A bound template template parm could later be instantiated to have a valid
23646 nontype parm type via an alias template. */
23652 {
23655 else
23657 type);
23658 }
23660 }
23662 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23663 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23665 static bool
23667 {
23668 tree scope;
23670 /* [temp.dep.type]
23672 A type is dependent if it is:
23674 -- a template parameter. Template template parameters are types
23675 for us (since TYPE_P holds true for them) so we handle
23676 them here. */
23680 /* -- a qualified-id with a nested-name-specifier which contains a
23681 class-name that names a dependent type or whose unqualified-id
23682 names a dependent type. */
23686 /* An alias template specialization can be dependent even if the
23687 resulting type is not. */
23691 /* -- a cv-qualified type where the cv-unqualified type is
23692 dependent.
23693 No code is necessary for this bullet; the code below handles
23694 cv-qualified types, and we don't want to strip aliases with
23695 TYPE_MAIN_VARIANT because of DR 1558. */
23696 /* -- a compound type constructed from any dependent type. */
23706 {
23707 tree arg_type;
23712 arg_type;
23717 {
23718 /* A value-dependent noexcept-specifier makes the type dependent. */
23723 }
23725 }
23726 /* -- an array type constructed from any dependent type or whose
23727 size is specified by a constant expression that is
23728 value-dependent.
23730 We checked for type- and value-dependence of the bounds in
23731 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23733 {
23738 }
23740 /* -- a template-id in which either the template name is a template
23741 parameter ... */
23744 /* ... or any of the template arguments is a dependent type or
23745 an expression that is type-dependent or value-dependent. */
23747 && (any_dependent_template_arguments_p
23751 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23752 dependent; if the argument of the `typeof' expression is not
23753 type-dependent, then it should already been have resolved. */
23759 /* A template argument pack is dependent if any of its packed
23760 arguments are. */
23762 {
23768 }
23770 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23771 be template parameters. */
23778 /* The standard does not specifically mention types that are local
23779 to template functions or local classes, but they should be
23780 considered dependent too. For example:
23782 template <int I> void f() {
23783 enum E { a = I };
23784 S<sizeof (E)> s;
23785 }
23787 The size of `E' cannot be known until the value of `I' has been
23788 determined. Therefore, `E' must be considered dependent. */
23792 /* Don't use type_dependent_expression_p here, as it can lead
23793 to infinite recursion trying to determine whether a lambda
23794 nested in a lambda is dependent (c++/47687). */
23798 && (any_dependent_template_arguments_p
23802 /* Other types are non-dependent. */
23804 }
23806 /* Returns TRUE if TYPE is dependent, in the sense of
23807 [temp.dep.type]. Note that a NULL type is considered dependent. */
23809 bool
23811 {
23812 /* If there are no template parameters in scope, then there can't be
23813 any dependent types. */
23815 {
23816 /* If we are not processing a template, then nobody should be
23817 providing us with a dependent type. */
23821 }
23823 /* If the type is NULL, we have not computed a type for the entity
23824 in question; in that case, the type is dependent. */
23828 /* Erroneous types can be considered non-dependent. */
23832 /* Getting here with global_type_node means we improperly called this
23833 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23836 /* If we have not already computed the appropriate value for TYPE,
23837 do so now. */
23839 {
23842 }
23845 }
23847 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23848 lookup. In other words, a dependent type that is not the current
23849 instantiation. */
23851 bool
23853 {
23856 }
23858 /* T is a SCOPE_REF; return whether we need to consider it
23859 instantiation-dependent so that we can check access at instantiation
23860 time even though we know which member it resolves to. */
23862 static bool
23864 {
23870 else
23872 }
23874 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23875 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23876 expression. */
23878 /* Note that this predicate is not appropriate for general expressions;
23879 only constant expressions (that satisfy potential_constant_expression)
23880 can be tested for value dependence. */
23882 bool
23884 {
23888 /* A name declared with a dependent type. */
23893 {
23895 /* A dependent member function of the current instantiation. */
23899 /* A dependent member function of the current instantiation. */
23906 /* A name that has not been looked up -- must be dependent. */
23910 /* A non-type template parm. */
23914 /* A non-type template parm. */
23920 /* A constant with literal type and is initialized
23921 with an expression that is value-dependent.
23923 Note that a non-dependent parenthesized initializer will have
23924 already been replaced with its constant value, so if we see
23925 a TREE_LIST it must be dependent. */
23929 /* cp_finish_decl doesn't fold reference initializers. */
23935 {
23939 }
23947 /* These expressions are value-dependent if the type to which
23948 the cast occurs is dependent or the expression being casted
23949 is value-dependent. */
23950 {
23956 /* A functional cast has a list of operands. */
23959 {
23960 /* If there are no operands, it must be an expression such
23961 as "int()". This should not happen for aggregate types
23962 because it would form non-constant expressions. */
23967 }
23973 }
23978 /* FALLTHRU */
23981 /* A `sizeof' expression is value-dependent if the operand is
23982 type-dependent or is a pack expansion. */
23991 /* An 'encode' expression is value-dependent if the operand is
23992 type-dependent. */
24001 /* All instantiation-dependent expressions should also be considered
24002 value-dependent. */
24010 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
24011 is value-dependent. */
24012 {
24021 }
24024 {
24041 }
24052 {
24056 }
24059 /* Treat all requires-expressions as value-dependent so
24060 we don't try to fold them. */
24067 {
24074 {
24076 /* In a call to a constexpr member function, look through the
24077 implicit ADDR_EXPR on the object argument so that it doesn't
24078 cause the call to be considered value-dependent. We also
24079 look through it in potential_constant_expression. */
24086 }
24088 }
24091 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
24092 type-dependent. */
24097 {
24099 tree val;
24106 }
24109 /* Treat a GNU statement expression as dependent to avoid crashing
24110 under instantiate_non_dependent_expr; it can't be constant. */
24114 /* A constant expression is value-dependent if any subexpression is
24115 value-dependent. */
24117 {
24124 {
24128 {
24131 /* In some cases, some of the operands may be missing.
24132 (For example, in the case of PREDECREMENT_EXPR, the
24133 amount to increment by may be missing.) That doesn't
24134 make the expression dependent. */
24137 }
24138 }
24142 }
24144 }
24146 /* The expression is not value-dependent. */
24148 }
24150 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24151 [temp.dep.expr]. Note that an expression with no type is
24152 considered dependent. Other parts of the compiler arrange for an
24153 expression with type-dependent subexpressions to have no type, so
24154 this function doesn't have to be fully recursive. */
24156 bool
24158 {
24165 /* An unresolved name is always dependent. */
24171 /* A fold expression is type-dependent. */
24178 /* Some expression forms are never type-dependent. */
24192 /* The types of these expressions depends only on the type to which
24193 the cast occurs. */
24202 /* The types of these expressions depends only on the type created
24203 by the expression. */
24206 {
24207 /* For NEW_EXPR tree nodes created inside a template, either
24208 the object type itself or a TREE_LIST may appear as the
24209 operand 1. */
24212 /* This is an array type. We need to check array dimensions
24213 as well. */
24215 || value_dependent_expression_p
24217 else
24219 }
24222 {
24226 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24227 contains an identifier associated by name lookup with one or more
24228 declarations declared with a dependent type, or...a
24229 nested-name-specifier or qualified-id that names a member of an
24230 unknown specialization. */
24233 }
24243 {
24244 tree elt;
24248 {
24251 }
24253 }
24255 /* A static data member of the current instantiation with incomplete
24256 array type is type-dependent, as the definition and specializations
24257 can have different bounds. */
24264 /* An array of unknown bound depending on a variadic parameter, eg:
24266 template<typename... Args>
24267 void foo (Args... args)
24268 {
24269 int arr[] = { args... };
24270 }
24272 template<int... vals>
24273 void bar ()
24274 {
24275 int arr[] = { vals... };
24276 }
24278 If the array has no length and has an initializer, it must be that
24279 we couldn't determine its length in cp_complete_array_type because
24280 it is dependent. */
24288 /* A function or variable template-id is type-dependent if it has any
24289 dependent template arguments. */
24293 {
24294 /* Consider the innermost template arguments, since those are the ones
24295 that come from the template-id; the template arguments for the
24296 enclosing class do not make it type-dependent unless they are used in
24297 the type of the decl. */
24299 && (any_dependent_template_arguments_p
24302 }
24304 /* Otherwise, if the function decl isn't from a dependent scope, it can't be
24305 type-dependent. Checking this is important for functions with auto return
24306 type, which looks like a dependent type. */
24314 {
24318 }
24320 /* Always dependent, on the number of arguments if nothing else. */
24325 {
24330 {
24336 }
24337 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24342 {
24347 }
24350 {
24357 }
24367 }
24371 /* Dependent type attributes might not have made it from the decl to
24372 the type yet. */
24378 }
24380 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24381 type-dependent if the expression refers to a member of the current
24382 instantiation and the type of the referenced member is dependent, or the
24383 class member access expression refers to a member of an unknown
24384 specialization.
24386 This function returns true if the OBJECT in such a class member access
24387 expression is of an unknown specialization. */
24389 bool
24391 {
24392 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24393 dependent. */
24398 }
24400 /* walk_tree callback function for instantiation_dependent_expression_p,
24401 below. Returns non-zero if a dependent subexpression is found. */
24403 static tree
24406 {
24408 {
24409 /* We don't have to worry about decltype currently because decltype
24410 of an instantiation-dependent expr is a dependent type. This
24411 might change depending on the resolution of DR 1172. */
24414 }
24417 {
24418 /* Don't treat an argument list as dependent just because it has no
24419 TREE_TYPE. */
24427 /* Handle expressions with type operands. */
24432 {
24437 {
24440 else
24441 {
24444 }
24445 }
24447 }
24451 /* In a template, finish_class_member_access_expr creates a
24452 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24453 type-dependent, so that we can check access control at
24454 instantiation time (PR 42277). See also Core issue 1273. */
24461 else
24464 /* Treat statement-expressions as dependent. */
24468 /* Treat requires-expressions as dependent. */
24473 /* Treat calls to function concepts as dependent. */
24479 /* And variable concepts. */
24486 }
24490 else
24492 }
24494 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24495 sense defined by the ABI:
24497 "An expression is instantiation-dependent if it is type-dependent
24498 or value-dependent, or it has a subexpression that is type-dependent
24499 or value-dependent."
24501 Except don't actually check value-dependence for unevaluated expressions,
24502 because in sizeof(i) we don't care about the value of i. Checking
24503 type-dependence will in turn check value-dependence of array bounds/template
24504 arguments as needed. */
24506 bool
24508 {
24509 tree result;
24520 }
24522 /* As above, but also check value-dependence of the expression as a whole. */
24524 bool
24526 {
24529 }
24531 /* Like type_dependent_expression_p, but it also works while not processing
24532 a template definition, i.e. during substitution or mangling. */
24534 bool
24536 {
24542 }
24544 /* Returns TRUE if ARGS contains a type-dependent expression. */
24546 bool
24548 {
24550 tree arg;
24553 {
24556 }
24558 }
24560 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24561 expressions) contains any type-dependent expressions. */
24563 bool
24565 {
24571 }
24573 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24574 expressions) contains any value-dependent expressions. */
24576 bool
24578 {
24584 }
24586 /* Returns TRUE if the ARG (a template argument) is dependent. */
24588 bool
24590 {
24594 /* Assume a template argument that was wrongly written by the user
24595 is dependent. This is consistent with what
24596 any_dependent_template_arguments_p [that calls this function]
24597 does. */
24607 {
24610 /* A member template of a dependent class is not necessarily
24611 type-dependent, but it is a dependent template argument because it
24612 will be a member of an unknown specialization to that template. */
24615 }
24617 {
24621 {
24624 }
24627 }
24630 else
24633 }
24635 /* Returns true if ARGS (a collection of template arguments) contains
24636 any types that require structural equality testing. */
24638 bool
24640 {
24650 {
24653 {
24659 {
24660 /* Look inside the argument pack. */
24663 }
24666 {
24679 }
24680 }
24681 }
24684 }
24686 /* Returns true if ARGS (a collection of template arguments) contains
24687 any dependent arguments. */
24689 bool
24691 {
24701 {
24706 }
24709 }
24711 /* Returns TRUE if the template TMPL is type-dependent. */
24713 bool
24715 {
24717 {
24722 }
24724 /* Template template parameters are dependent. */
24728 /* So are names that have not been looked up. */
24732 }
24734 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24736 bool
24738 {
24741 }
24743 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24744 are dependent. */
24746 bool
24748 {
24755 {
24777 {
24781 }
24785 {
24789 {
24794 }
24795 }
24796 }
24799 }
24801 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24802 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24803 no such TYPE can be found. Note that this function peers inside
24804 uninstantiated templates and therefore should be used only in
24805 extremely limited situations. ONLY_CURRENT_P restricts this
24806 peering to the currently open classes hierarchy (which is required
24807 when comparing types). */
24809 tree
24811 {
24812 tree scope;
24813 tree name;
24814 tree decl;
24816 tree pushed_scope;
24817 tree result;
24822 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24823 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24824 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24825 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24826 identifier of the TYPENAME_TYPE anymore.
24827 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24828 TYPENAME_TYPE instead, we avoid messing up with a possible
24829 typedef variant case. */
24832 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24833 it first before we can figure out what NAME refers to. */
24835 {
24837 /* Given a class template A with a dependent base with nested type C,
24838 typedef typename A::C::C C will land us here, as trying to resolve
24839 the initial A::C leads to the local C typedef, which leads back to
24840 A::C::C. So we break the recursion now. */
24842 else
24844 }
24845 /* If we don't know what SCOPE refers to, then we cannot resolve the
24846 TYPENAME_TYPE. */
24849 /* If this is a typedef, we don't want to look inside (c++/11987). */
24852 /* If SCOPE isn't the template itself, it will not have a valid
24853 TYPE_FIELDS list. */
24855 /* scope is either the template itself or a compatible instantiation
24856 like X<T>, so look up the name in the original template. */
24858 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24860 /* If scope has no fields, it can't be a current instantiation. Check this
24861 before currently_open_class to avoid infinite recursion (71515). */
24864 /* If the SCOPE is not the current instantiation, there's no reason
24865 to look inside it. */
24868 /* Enter the SCOPE so that name lookup will be resolved as if we
24869 were in the class definition. In particular, SCOPE will no
24870 longer be considered a dependent type. */
24872 /* Look up the declaration. */
24874 tf_warning_or_error);
24878 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24879 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24885 {
24889 }
24892 {
24893 /* Obtain the template and the arguments. */
24896 {
24897 /* We get here with a plain identifier because a previous tentative
24898 parse of the nested-name-specifier as part of a ptr-operator saw
24899 ::template X<A>. The use of ::template is necessary in a
24900 ptr-operator, but wrong in a declarator-id.
24902 [temp.names]: In a qualified-id of a declarator-id, the keyword
24903 template shall not appear at the top level. */
24907 }
24909 /* Instantiate the template. */
24915 }
24917 /* Leave the SCOPE. */
24921 /* If we failed to resolve it, return the original typename. */
24925 /* If lookup found a typename type, resolve that too. */
24927 {
24928 /* Ill-formed programs can cause infinite recursion here, so we
24929 must catch that. */
24933 }
24935 /* Qualify the resulting type. */
24941 }
24943 /* EXPR is an expression which is not type-dependent. Return a proxy
24944 for EXPR that can be used to compute the types of larger
24945 expressions containing EXPR. */
24947 tree
24949 {
24950 tree inner_expr;
24952 /* When checking, try to get a constant value for all non-dependent
24953 expressions in order to expose bugs in *_dependent_expression_p
24954 and constexpr. This can affect code generation, see PR70704, so
24955 only do this for -fchecking=2. */
24958 /* Don't do this during nsdmi parsing as it can lead to
24959 unexpected recursive instantiations. */
24961 /* Don't do this during concept expansion either and for
24962 the same reason. */
24966 /* Preserve OVERLOADs; the functions must be available to resolve
24967 types. */
24978 /* There is no need to return a proxy for a variable. */
24981 /* Preserve string constants; conversions from string constants to
24982 "char *" are allowed, even though normally a "const char *"
24983 cannot be used to initialize a "char *". */
24986 /* Preserve void and arithmetic constants, as an optimization -- there is no
24987 reason to create a new node. */
24992 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24993 There is at least one place where we want to know that a
24994 particular expression is a throw-expression: when checking a ?:
24995 expression, there are special rules if the second or third
24996 argument is a throw-expression. */
25000 /* Don't wrap an initializer list, we need to be able to look inside. */
25004 /* Don't wrap a dummy object, we need to be able to test for it. */
25023 /* If the type is unknown, it can't really be non-dependent */
25026 /* Otherwise, build a NON_DEPENDENT_EXPR. */
25028 }
25030 /* ARGS is a vector of expressions as arguments to a function call.
25031 Replace the arguments with equivalent non-dependent expressions.
25032 This modifies ARGS in place. */
25034 void
25036 {
25038 tree arg;
25041 {
25045 }
25046 }
25048 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
25049 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
25050 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
25052 static tree
25054 {
25068 }
25070 tree
25072 {
25074 }
25076 tree
25078 {
25080 }
25082 /* Return a C++17 deduction placeholder for class template TMPL. */
25084 tree
25086 {
25090 }
25092 /* True iff T is a C++17 class template deduction placeholder. */
25094 bool
25096 {
25098 }
25100 /* Make a "constrained auto" type-specifier. This is an
25101 auto type with constraints that must be associated after
25102 deduction. The constraint is formed from the given
25103 CONC and its optional sequence of arguments, which are
25104 non-null if written as partial-concept-id. */
25106 tree
25108 {
25111 /* Build the constraint. */
25119 /* Our canonical type depends on the constraint. */
25122 /* Attach the constraint to the type declaration. */
25125 }
25127 /* Given type ARG, return std::initializer_list<ARG>. */
25129 static tree
25131 {
25135 {
25139 "deducing from brace-enclosed initializer list"
25143 }
25149 }
25151 /* Replace auto in TYPE with std::initializer_list<auto>. */
25153 static tree
25155 {
25162 }
25164 /* Hash traits for hashing possibly constrained 'auto'
25165 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25168 {
25171 };
25173 /* Hash the 'auto' T. */
25175 inline hashval_t
25177 {
25179 /* Matching constrained-type-specifiers denote the same template
25180 parameter, so hash the constraint. */
25182 else
25183 /* But unconstrained autos are all separate, so just hash the pointer. */
25185 }
25187 /* Compare two 'auto's. */
25191 {
25198 /* Two unconstrained autos are distinct. */
25203 }
25205 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25206 constrained) auto, add it to the vector. */
25208 static int
25210 {
25213 {
25214 /* All the autos were built with index 0; fix that up now. */
25218 /* If this is a repeated constrained-type-specifier, use the index we
25219 chose before. */
25221 else
25222 {
25223 /* Otherwise this is new, so use the current count. */
25226 }
25228 }
25230 /* Always keep walking. */
25232 }
25234 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25235 says they can appear anywhere in the type. */
25237 static tree
25239 {
25248 {
25253 }
25256 }
25258 /* The stem for deduction guide names. */
25261 /* Return the name for a deduction guide for class template TMPL. */
25263 tree
25265 {
25276 }
25278 /* True if NAME is the name of a deduction guide. */
25280 bool
25282 {
25286 }
25288 /* True if FN is a deduction guide. */
25290 bool
25292 {
25297 }
25299 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25301 bool
25303 {
25310 }
25312 /* True if FN is a guide generated from a constructor template. */
25314 bool
25316 {
25324 }
25326 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25327 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25328 template parameter types. Note that the handling of template template
25329 parameters relies on current_template_parms being set appropriately for the
25330 new template. */
25332 static tree
25335 {
25338 tree newtype;
25341 {
25348 }
25349 else
25353 tree newdecl
25358 tree newidx;
25361 {
25371 {
25376 // First create a copy (ttargs) of tsubst_args with an
25377 // additional level for the template template parameter's own
25378 // template parameters (ttparms).
25379 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25387 // Substitute ttargs into ttparms to fix references to
25388 // other template parameters.
25390 complain);
25391 // Now substitute again with args based on tparms, to reduce
25392 // the level of the ttparms.
25395 complain);
25396 // Finally, tack the adjusted parms onto tparms.
25398 current_template_parms);
25400 }
25401 }
25402 else
25403 {
25405 tree newconst
25417 }
25420 }
25422 /* Returns a C++17 class deduction guide template based on the constructor
25423 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25424 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25426 static tree
25428 {
25432 location_t loc;
25436 {
25440 {
25443 }
25444 else
25454 }
25455 else
25456 {
25459 fn_tmpl
25469 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25470 fully specialized args for the enclosing class. Strip those off, as
25471 the deduction guide won't have those template parameters. */
25474 /* Discard the 'this' parameter. */
25482 {
25485 /* For a member template constructor, we need to flatten the two
25486 template parameter lists into one, and then adjust the function
25487 signature accordingly. This gets...complicated. */
25490 /* For a member template we should have two levels of parms/args, one
25491 for the class and one for the constructor. We stripped
25492 specialized args for further enclosing classes above. */
25496 /* Template args for translating references to the two-level template
25497 parameters into references to the one-level template parameters we
25498 are creating. */
25503 /* Template parms for the constructor template. */
25506 /* Template parms for the class template. */
25510 /* Template parms for the deduction guide start as a copy of the
25511 template parms for the class. We set current_template_parms for
25512 lookup_template_class_1. */
25518 /* Now we need to rewrite the constructor parms to append them to the
25519 class parms. */
25521 {
25536 }
25538 /* Now we have a final set of template parms to substitute into the
25539 function signature. */
25548 }
25550 }
25553 {
25554 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25558 }
25562 FUNCTION_DECL,
25579 }
25581 /* Deduce template arguments for the class template placeholder PTYPE for
25582 template TMPL based on the initializer INIT, and return the resulting
25583 type. */
25585 static tree
25587 tsubst_flags_t complain)
25588 {
25590 {
25591 /* We should have handled this in the caller. */
25597 }
25608 {
25611 {
25612 /* As an exception, the first phase in 16.3.1.7 (considering the
25613 initializer list as a single argument) is omitted if the
25614 initializer list consists of a single expression of type cv U,
25615 where U is a specialization of C or a class derived from a
25616 specialization of C. */
25627 }
25630 else
25632 }
25633 else
25644 /* Prune explicit deduction guides in copy-initialization context. */
25646 {
25652 {
25653 /* Found a nonconverting guide, prune the candidates. */
25660 }
25661 }
25666 {
25669 }
25672 // FIXME cache artificial deduction guides
25674 {
25679 else
25683 }
25687 /* If this is list-initialization and the class has a list constructor, first
25688 try deducing from the list as a single argument, as [over.match.list]. */
25692 {
25696 }
25698 {
25704 {
25705 /* That didn't work, now try treating the list as a sequence of
25706 arguments. */
25709 }
25710 }
25712 /* Maybe generate an implicit deduction guide. */
25714 {
25718 /* Generate a copy guide. */
25721 /* Generate a default guide. */
25725 {
25728 }
25729 }
25732 {
25734 " of %qT, as it has no non-explicit deduction guides or "
25737 }
25739 {
25743 }
25746 {
25750 }
25753 {
25763 }
25768 }
25770 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25771 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25773 tree
25775 {
25777 tf_warning_or_error,
25778 adc_unspecified);
25779 }
25781 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25782 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25783 The CONTEXT determines the context in which auto deduction is performed
25784 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25785 OUTER_TARGS are used during template argument deduction
25786 (context == adc_unify) to properly substitute the result, and is ignored
25787 in other contexts.
25789 For partial-concept-ids, extra args may be appended to the list of deduced
25790 template arguments prior to determining constraint satisfaction. */
25792 tree
25796 {
25797 tree targs;
25804 /* Defining a subset of type-dependent expressions that we can deduce
25805 from ahead of time isn't worth the trouble. */
25809 /* C++17 class template argument deduction. */
25813 /* Nothing we can do with this, even in deduction context. */
25816 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25817 with either a new invented type template parameter U or, if the
25818 initializer is a braced-init-list (8.5.4), with
25819 std::initializer_list<U>. */
25821 {
25826 else
25827 {
25829 {
25833 "for deduction to %<std::initializer_list%>, use copy-"
25835 }
25837 }
25838 }
25849 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25850 and initializer has array type, deduce cv-qualified array type. */
25852 complain);
25854 {
25863 {
25867 }
25868 }
25869 else
25870 {
25872 tree tparms;
25876 else
25877 {
25881 }
25888 {
25890 /* Try again at instantiation time. */
25894 /* If type is error_mark_node a diagnostic must have been
25895 emitted by now. Also, having a mention to '<type error>'
25896 in the diagnostic is not really useful to the user. */
25897 {
25901 else
25906 }
25908 }
25909 }
25911 /* Check any placeholder constraints against the deduced type. */
25914 {
25915 /* Use the deduced type to check the associated constraints. If we
25916 have a partial-concept-id, rebuild the argument list so that
25917 we check using the extra arguments. */
25921 {
25924 }
25925 else
25928 {
25930 {
25932 {
25950 }
25952 }
25954 }
25955 }
25961 }
25963 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25964 result. */
25966 tree
25968 {
25970 {
25976 /* In an abbreviated function template we didn't know we were dealing
25977 with a function template when we saw the auto return type, so update
25978 it to have the correct level. */
25980 }
25982 }
25984 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25985 'decltype(auto)' or a deduced class template. */
25987 bool
25989 {
25995 else
25997 }
25999 /* for_each_template_parm callback for type_uses_auto. */
26001 int
26003 {
26005 }
26007 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
26008 a use of `auto'. Returns NULL_TREE otherwise. */
26010 tree
26012 {
26016 {
26017 /* The Concepts TS allows multiple autos in one type-specifier; just
26018 return the first one we find, do_auto_deduction will collect all of
26019 them. */
26023 else
26025 }
26026 else
26028 }
26030 /* For a given template T, return the vector of typedefs referenced
26031 in T for which access check is needed at T instantiation time.
26032 T is either a FUNCTION_DECL or a RECORD_TYPE.
26033 Those typedefs were added to T by the function
26034 append_type_to_template_for_access_check. */
26038 {
26039 tree ti;
26050 {
26055 }
26058 }
26060 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26061 tied to T. That list of typedefs will be access checked at
26062 T instantiation time.
26063 T is either a FUNCTION_DECL or a RECORD_TYPE.
26064 TYPE_DECL is a TYPE_DECL node representing a typedef.
26065 SCOPE is the scope through which TYPE_DECL is accessed.
26066 LOCATION is the location of the usage point of TYPE_DECL.
26068 This function is a subroutine of
26069 append_type_to_template_for_access_check. */
26071 static void
26073 tree type_decl,
26074 tree scope,
26075 location_t location)
26076 {
26077 qualified_typedef_usage_t typedef_usage;
26078 tree ti;
26085 && type_decl
26099 }
26101 /* Append TYPE_DECL to the template TEMPL.
26102 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26103 At TEMPL instanciation time, TYPE_DECL will be checked to see
26104 if it can be accessed through SCOPE.
26105 LOCATION is the location of the usage point of TYPE_DECL.
26107 e.g. consider the following code snippet:
26109 class C
26110 {
26111 typedef int myint;
26112 };
26114 template<class U> struct S
26115 {
26116 C::myint mi; // <-- usage point of the typedef C::myint
26117 };
26119 S<char> s;
26121 At S<char> instantiation time, we need to check the access of C::myint
26122 In other words, we need to check the access of the myint typedef through
26123 the C scope. For that purpose, this function will add the myint typedef
26124 and the scope C through which its being accessed to a list of typedefs
26125 tied to the template S. That list will be walked at template instantiation
26126 time and access check performed on each typedefs it contains.
26127 Note that this particular code snippet should yield an error because
26128 myint is private to C. */
26130 void
26132 tree type_decl,
26133 tree scope,
26134 location_t location)
26135 {
26141 /* Make sure we don't append the type to the template twice. */
26148 }
26150 /* Convert the generic type parameters in PARM that match the types given in the
26151 range [START_IDX, END_IDX) from the current_template_parms into generic type
26152 packs. */
26154 tree
26156 {
26167 {
26168 /* Create a distinct parameter pack type from the current parm and add it
26169 to the replacement args to tsubst below into the generic function
26170 parameter. */
26185 }
26191 /* If there are more levels then build up the replacement with the outer
26192 template parms. */
26196 replacement);
26199 }
26201 /* Entries in the decl_constraint hash table. */
26203 {
26204 tree decl;
26205 tree ci;
26206 };
26208 /* Hashing function and equality for constraint entries. */
26210 {
26212 {
26214 }
26217 {
26219 }
26220 };
26222 /* A mapping from declarations to constraint information. Note that
26223 both templates and their underlying declarations are mapped to the
26224 same constraint information.
26226 FIXME: This is defined in pt.c because garbage collection
26227 code is not being generated for constraint.cc. */
26231 /* Returns the template constraints of declaration T. If T is not
26232 constrained, return NULL_TREE. Note that T must be non-null. */
26234 tree
26236 {
26247 else
26249 }
26251 /* Associate the given constraint information CI with the declaration
26252 T. If T is a template, then the constraints are associated with
26253 its underlying declaration. Don't build associations if CI is
26254 NULL_TREE. */
26256 void
26258 {
26270 }
26272 /* Remove the associated constraints of the declaration T. */
26274 void
26276 {
26285 }
26287 /* Memoized satisfaction results for declarations. This
26288 maps the pair (constraint_info, arguments) to the result computed
26289 by constraints_satisfied_p. */
26292 {
26293 tree ci;
26294 tree args;
26295 tree result;
26296 };
26298 /* Hashing function and equality for constraint entries. */
26301 {
26303 {
26306 }
26309 {
26311 }
26312 };
26314 /* Memoized satisfaction results for concept checks. */
26317 {
26318 tree tmpl;
26319 tree args;
26320 tree result;
26321 };
26323 /* Hashing function and equality for constraint entries. */
26326 {
26328 {
26330 }
26333 {
26338 }
26339 };
26344 /* Search for a memoized satisfaction result. Returns one of the
26345 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26347 tree
26349 {
26354 else
26356 }
26358 /* Memoize the result of a satisfication test. Returns the saved result. */
26360 tree
26362 {
26369 }
26371 /* Search for a memoized satisfaction result for a concept. */
26373 tree
26375 {
26380 else
26382 }
26384 /* Memoize the result of a concept check. Returns the saved result. */
26386 tree
26388 {
26395 }
26399 /* Returns a prior concept specialization. This returns the substituted
26400 and normalized constraints defined by the concept. */
26402 tree
26404 {
26409 else
26411 }
26413 /* Save a concept expansion for later. */
26415 tree
26417 {
26424 }
26426 static hashval_t
26428 {
26437 }
26439 /* Compare the constraints of two subsumption entries. The LEFT1 and
26440 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26441 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26443 static bool
26445 {
26453 }
26455 /* Key/value pair for learning and memoizing subsumption results. This
26456 associates a pair of check constraints (including arguments) with
26457 a boolean value indicating the result. */
26460 {
26461 tree t1;
26462 tree t2;
26464 };
26466 /* Hashing function and equality for constraint entries. */
26469 {
26471 {
26473 }
26476 {
26481 }
26482 };
26486 /* Search for a previously cached subsumption result. */
26490 {
26495 else
26497 }
26499 /* Save a subsumption result. */
26501 bool
26503 {
26510 }
26512 /* Set up the hash table for constraint association. */
26514 void
26516 {
26525 }
26527 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26528 0..N-1. */
26530 void
26532 {
26535 integer_type_node,
26536 NULL_TREE),
26540 }
26542 /* Set up the hash tables for template instantiations. */
26544 void
26546 {
26552 }
26554 /* Print stats about the template hash tables for -fstats. */
26556 void
26558 {
26567 }