| blob | 141b4d7564a8de9d1a2c0041cdfbce5ea5bda404 |
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. */
1197 {
1202 /* But generic lambda functions are instantiated normally, once their
1203 containing context is fully instantiated. */
1205 }
1208 {
1209 /* The template arguments actually apply to the containing
1210 class. Find the class specialization with those
1211 arguments. */
1213 tree class_specialization
1218 /* Find the instance of TMPL. */
1221 {
1224 /* using-declarations can add base methods to the method vec,
1225 and we don't want those here. */
1228 }
1230 }
1231 else
1232 {
1234 spec_entry elt;
1243 else
1251 }
1254 }
1256 /* Like retrieve_specialization, but for local declarations. */
1258 tree
1260 {
1266 }
1268 /* Returns nonzero iff DECL is a specialization of TMPL. */
1270 int
1272 {
1273 tree t;
1276 {
1282 }
1283 else
1284 {
1293 }
1296 }
1298 /* Returns nonzero iff DECL is a specialization of friend declaration
1299 FRIEND_DECL according to [temp.friend]. */
1301 bool
1303 {
1310 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1311 of a template class, we want to check if DECL is a specialization
1312 if this. */
1316 {
1317 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1320 }
1325 /* There is nothing to do if this is not a template friend. */
1332 /* [temp.friend/6]
1333 A member of a class template may be declared to be a friend of a
1334 non-template class. In this case, the corresponding member of
1335 every specialization of the class template is a friend of the
1336 class granting friendship.
1338 For example, given a template friend declaration
1340 template <class T> friend void A<T>::f();
1342 the member function below is considered a friend
1344 template <> struct A<int> {
1345 void f();
1346 };
1348 For this type of template friend, TEMPLATE_DEPTH below will be
1349 nonzero. To determine if DECL is a friend of FRIEND, we first
1350 check if the enclosing class is a specialization of another. */
1357 {
1358 /* Next, we check the members themselves. In order to handle
1359 a few tricky cases, such as when FRIEND_DECL's are
1361 template <class T> friend void A<T>::g(T t);
1362 template <class T> template <T t> friend void A<T>::h();
1364 and DECL's are
1366 void A<int>::g(int);
1367 template <int> void A<int>::h();
1369 we need to figure out ARGS, the template arguments from
1370 the context of DECL. This is required for template substitution
1371 of `T' in the function parameter of `g' and template parameter
1372 of `h' in the above examples. Here ARGS corresponds to `int'. */
1379 {
1381 {
1384 else
1386 current_depth++;
1387 }
1389 }
1392 {
1394 tree friend_type;
1395 tree decl_type;
1396 tree friend_args_type;
1397 tree decl_args_type;
1399 /* Make sure that both DECL and FRIEND_DECL are templates or
1400 non-templates. */
1406 {
1407 /* If both are templates, check template parameter list. */
1408 tree friend_parms
1413 friend_parms))
1417 }
1418 else
1426 /* Check if return types match. */
1430 /* Check if function parameter types match, ignoring the
1431 `this' parameter. */
1440 }
1441 else
1442 {
1443 /* DECL is a TYPE_DECL */
1447 /* Make sure that both DECL and FRIEND_DECL are templates or
1448 non-templates. */
1449 is_template
1456 {
1457 tree friend_parms;
1458 /* If both are templates, check the name of the two
1459 TEMPLATE_DECL's first because is_friend didn't. */
1464 /* Now check template parameter list. */
1465 friend_parms
1468 return comp_template_parms
1470 friend_parms);
1471 }
1472 else
1475 }
1476 }
1478 }
1480 /* Register the specialization SPEC as a specialization of TMPL with
1481 the indicated ARGS. IS_FRIEND indicates whether the specialization
1482 is actually just a friend declaration. Returns SPEC, or an
1483 equivalent prior declaration, if available.
1485 We also store instantiations of field packs in the hash table, even
1486 though they are not themselves templates, to make lookup easier. */
1488 static tree
1490 hashval_t hash)
1491 {
1492 tree fn;
1494 spec_entry elt;
1502 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1503 register it; we want the corresponding TEMPLATE_DECL instead.
1504 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1505 the more obvious `uses_template_parms (spec)' to avoid problems
1506 with default function arguments. In particular, given
1507 something like this:
1509 template <class T> void f(T t1, T t = T())
1511 the default argument expression is not substituted for in an
1512 instantiation unless and until it is actually needed. */
1516 /* We don't put these specializations in the hash table, but we might
1517 want to give an error about a mismatch. */
1519 else
1520 {
1528 slot =
1532 else
1534 }
1536 /* We can sometimes try to re-register a specialization that we've
1537 already got. In particular, regenerate_decl_from_template calls
1538 duplicate_decls which will update the specialization list. But,
1539 we'll still get called again here anyhow. It's more convenient
1540 to simply allow this than to try to prevent it. */
1544 {
1546 {
1549 {
1551 fn);
1553 }
1554 else
1555 {
1556 tree clone;
1557 /* This situation should occur only if the first
1558 specialization is an implicit instantiation, the
1559 second is an explicit specialization, and the
1560 implicit instantiation has not yet been used. That
1561 situation can occur if we have implicitly
1562 instantiated a member function and then specialized
1563 it later.
1565 We can also wind up here if a friend declaration that
1566 looked like an instantiation turns out to be a
1567 specialization:
1569 template <class T> void foo(T);
1570 class S { friend void foo<>(int) };
1571 template <> void foo(int);
1573 We transform the existing DECL in place so that any
1574 pointers to it become pointers to the updated
1575 declaration.
1577 If there was a definition for the template, but not
1578 for the specialization, we want this to look as if
1579 there were no definition, and vice versa. */
1582 /* The call to duplicate_decls will have applied
1583 [temp.expl.spec]:
1585 An explicit specialization of a function template
1586 is inline only if it is explicitly declared to be,
1587 and independently of whether its function template
1588 is.
1590 to the primary function; now copy the inline bits to
1591 the various clones. */
1593 {
1600 }
1604 }
1605 }
1607 {
1610 /* We've already complained in duplicate_decls. */
1614 /* Dup decl failed, but this is a new definition. Set the
1615 line number so any errors match this new
1616 definition. */
1620 }
1621 }
1625 /* A specialization must be declared in the same namespace as the
1626 template it is specializing. */
1632 {
1641 /* If TMPL is a forward declaration of a template function, keep a list
1642 of all specializations in case we need to reassign them to a friend
1643 template later in tsubst_friend_function.
1645 Also keep a list of all variable template instantiations so that
1646 process_partial_specialization can check whether a later partial
1647 specialization would have used it. */
1650 }
1653 }
1655 /* Returns true iff two spec_entry nodes are equivalent. */
1659 bool
1661 {
1668 /* tmpl could be a FIELD_DECL for a capture pack. */
1672 {
1673 /* Partial specializations of a variable template can be distinguished by
1674 constraints. */
1678 }
1682 }
1684 /* Returns a hash for a template TMPL and template arguments ARGS. */
1686 static hashval_t
1688 {
1691 }
1693 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1694 ignoring SPEC. */
1696 hashval_t
1698 {
1700 }
1702 /* Recursively calculate a hash value for a template argument ARG, for use
1703 in the hash tables of template specializations. */
1705 hashval_t
1707 {
1727 {
1735 {
1740 }
1762 {
1766 {
1769 }
1771 }
1775 {
1778 }
1789 val = iterative_hash_template_arg
1801 val);
1803 val);
1812 /* A lambda can't appear in a template arg, but don't crash on
1813 erroneous input. */
1825 /* Now hash operands as usual. */
1830 }
1833 {
1836 {
1837 // We want an alias specialization that survived strip_typedefs
1838 // to hash differently from its TYPE_CANONICAL, to avoid hash
1839 // collisions that compare as different in template_args_equal.
1840 // These could be dependent specializations that strip_typedefs
1841 // left alone, or untouched specializations because
1842 // coerce_template_parms returns the unconverted template
1843 // arguments if it sees incomplete argument packs.
1846 }
1849 val);
1852 /* Otherwise just compare the types during lookup. */
1861 {
1866 }
1867 }
1870 }
1872 /* Unregister the specialization SPEC as a specialization of TMPL.
1873 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1874 if the SPEC was listed as a specialization of TMPL.
1876 Note that SPEC has been ggc_freed, so we can't look inside it. */
1878 bool
1880 {
1882 spec_entry elt;
1890 {
1895 }
1898 }
1900 /* Like register_specialization, but for local declarations. We are
1901 registering SPEC, an instantiation of TMPL. */
1903 void
1905 {
1907 }
1909 /* TYPE is a class type. Returns true if TYPE is an explicitly
1910 specialized class. */
1912 bool
1914 {
1918 }
1920 /* Print the list of functions at FNS, going through all the overloads
1921 for each element of the list. Alternatively, FNS can not be a
1922 TREE_LIST, in which case it will be printed together with all the
1923 overloads.
1925 MORE and *STR should respectively be FALSE and NULL when the function
1926 is called from the outside. They are used internally on recursive
1927 calls. print_candidates manages the two parameters and leaves NULL
1928 in *STR when it ends. */
1930 static void
1932 {
1936 else
1938 {
1944 {
1947 else
1950 }
1952 }
1953 }
1955 /* Print the list of candidate FNS in an error message. FNS can also
1956 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1958 void
1960 {
1964 }
1966 /* Get a (possibly) constrained template declaration for the
1967 purpose of ordering candidates. */
1968 static tree
1970 {
1976 }
1978 /* Among candidates having the same signature, return the
1979 most constrained or NULL_TREE if there is no best candidate.
1980 If the signatures of candidates vary (e.g., template
1981 specialization vs. member function), then there can be no
1982 most constrained.
1984 Note that we don't compare constraints on the functions
1985 themselves, but rather those of their templates. */
1986 static tree
1988 {
1989 // Try to find the best candidate in a first pass.
1992 {
1999 }
2001 // Verify that the champ is better than previous candidates.
2006 }
2009 }
2012 /* Returns the template (one of the functions given by TEMPLATE_ID)
2013 which can be specialized to match the indicated DECL with the
2014 explicit template args given in TEMPLATE_ID. The DECL may be
2015 NULL_TREE if none is available. In that case, the functions in
2016 TEMPLATE_ID are non-members.
2018 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2019 specialization of a member template.
2021 The TEMPLATE_COUNT is the number of references to qualifying
2022 template classes that appeared in the name of the function. See
2023 check_explicit_specialization for a more accurate description.
2025 TSK indicates what kind of template declaration (if any) is being
2026 declared. TSK_TEMPLATE indicates that the declaration given by
2027 DECL, though a FUNCTION_DECL, has template parameters, and is
2028 therefore a template function.
2030 The template args (those explicitly specified and those deduced)
2031 are output in a newly created vector *TARGS_OUT.
2033 If it is impossible to determine the result, an error message is
2034 issued. The error_mark_node is returned to indicate failure. */
2036 static tree
2038 tree decl,
2042 tmpl_spec_kind tsk)
2043 {
2044 tree fns;
2045 tree targs;
2046 tree explicit_targs;
2049 /* A TREE_LIST of templates of which DECL may be a specialization.
2050 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2051 corresponding TREE_PURPOSE is the set of template arguments that,
2052 when used to instantiate the template, would produce a function
2053 with the signature of DECL. */
2063 /* We shouldn't be specializing a member template of an
2064 unspecialized class template; we already gave an error in
2065 check_specialization_scope, now avoid crashing. */
2068 {
2071 }
2079 /* Check for baselinks. */
2084 {
2087 }
2089 {
2092 }
2094 /* Count the number of template headers specified for this
2095 specialization. */
2105 {
2108 tf_warning_or_error,
2112 }
2114 {
2118 {
2119 tree decl_arg_types;
2120 tree fn_arg_types;
2121 tree insttype;
2123 /* In case of explicit specialization, we need to check if
2124 the number of template headers appearing in the specialization
2125 is correct. This is usually done in check_explicit_specialization,
2126 but the check done there cannot be exhaustive when specializing
2127 member functions. Consider the following code:
2129 template <> void A<int>::f(int);
2130 template <> template <> void A<int>::f(int);
2132 Assuming that A<int> is not itself an explicit specialization
2133 already, the first line specializes "f" which is a non-template
2134 member function, whilst the second line specializes "f" which
2135 is a template member function. So both lines are syntactically
2136 correct, and check_explicit_specialization does not reject
2137 them.
2139 Here, we can do better, as we are matching the specialization
2140 against the declarations. We count the number of template
2141 headers, and we check if they match TEMPLATE_COUNT + 1
2142 (TEMPLATE_COUNT is the number of qualifying template classes,
2143 plus there must be another header for the member template
2144 itself).
2146 Notice that if header_count is zero, this is not a
2147 specialization but rather a template instantiation, so there
2148 is no check we can perform here. */
2152 /* Check that the number of template arguments at the
2153 innermost level for DECL is the same as for FN. */
2161 /* DECL might be a specialization of FN. */
2165 /* For a non-static member function, we need to make sure
2166 that the const qualification is the same. Since
2167 get_bindings does not try to merge the "this" parameter,
2168 we must do the comparison explicitly. */
2174 /* Skip the "this" parameter and, for constructors of
2175 classes with virtual bases, the VTT parameter. A
2176 full specialization of a constructor will have a VTT
2177 parameter, but a template never will. */
2178 decl_arg_types
2180 fn_arg_types
2183 /* Function templates cannot be specializations; there are
2184 no partial specializations of functions. Therefore, if
2185 the type of DECL does not match FN, there is no
2186 match.
2188 Note that it should never be the case that we have both
2189 candidates added here, and for regular member functions
2190 below. */
2192 {
2196 }
2198 /* See whether this function might be a specialization of this
2199 template. Suppress access control because we might be trying
2200 to make this specialization a friend, and we have already done
2201 access control for the declaration of the specialization. */
2207 /* We cannot deduce template arguments that when used to
2208 specialize TMPL will produce DECL. */
2211 /* Remove, from the set of candidates, all those functions
2212 whose constraints are not satisfied. */
2216 // Then, try to form the new function type.
2220 fn_arg_types
2225 /* Save this template, and the arguments deduced. */
2227 }
2229 /* FN is an ordinary member function, and we need a
2230 specialization of a member template. */
2231 ;
2233 /* We can get IDENTIFIER_NODEs here in certain erroneous
2234 cases. */
2235 ;
2237 /* This is just an ordinary non-member function. Nothing can
2238 be a specialization of that. */
2239 ;
2241 /* Cannot specialize functions that are created implicitly. */
2242 ;
2243 else
2244 {
2245 tree decl_arg_types;
2247 /* This is an ordinary member function. However, since
2248 we're here, we can assume its enclosing class is a
2249 template class. For example,
2251 template <typename T> struct S { void f(); };
2252 template <> void S<int>::f() {}
2254 Here, S<int>::f is a non-template, but S<int> is a
2255 template class. If FN has the same type as DECL, we
2256 might be in business. */
2259 /* Its enclosing class is an explicit specialization
2260 of a template class. This is not a candidate. */
2265 /* The return types differ. */
2268 /* Adjust the type of DECL in case FN is a static member. */
2275 decl_arg_types))
2278 // If the deduced arguments do not satisfy the constraints,
2279 // this is not a candidate.
2283 // Add the candidate.
2285 }
2286 }
2289 {
2290 /* We have:
2292 [temp.expl.spec]
2294 It is possible for a specialization with a given function
2295 signature to be instantiated from more than one function
2296 template. In such cases, explicit specification of the
2297 template arguments must be used to uniquely identify the
2298 function template specialization being specialized.
2300 Note that here, there's no suggestion that we're supposed to
2301 determine which of the candidate templates is most
2302 specialized. However, we, also have:
2304 [temp.func.order]
2306 Partial ordering of overloaded function template
2307 declarations is used in the following contexts to select
2308 the function template to which a function template
2309 specialization refers:
2311 -- when an explicit specialization refers to a function
2312 template.
2314 So, we do use the partial ordering rules, at least for now.
2315 This extension can only serve to make invalid programs valid,
2316 so it's safe. And, there is strong anecdotal evidence that
2317 the committee intended the partial ordering rules to apply;
2318 the EDG front end has that behavior, and John Spicer claims
2319 that the committee simply forgot to delete the wording in
2320 [temp.expl.spec]. */
2323 {
2326 }
2327 }
2329 // Concepts allows multiple declarations of member functions
2330 // with the same signature. Like above, we need to rely on
2331 // on the partial ordering of those candidates to determine which
2332 // is the best.
2334 {
2336 {
2339 }
2340 }
2343 {
2350 else
2353 }
2357 {
2363 }
2365 /* We have one, and exactly one, match. */
2367 {
2371 // Propagate the candidate's constraints to the declaration.
2374 /* DECL is a re-declaration or partial instantiation of a template
2375 function. */
2378 /* It was a specialization of an ordinary member function in a
2379 template class. */
2381 }
2383 /* It was a specialization of a template. */
2386 {
2391 }
2392 else
2395 }
2397 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2398 but with the default argument values filled in from those in the
2399 TMPL_TYPES. */
2401 static tree
2403 tree tmpl_types)
2404 {
2405 tree new_spec_types;
2413 /* Substitute into the rest of the list. */
2414 new_spec_types =
2418 /* Add the default argument for this parameter. */
2421 new_spec_types);
2422 }
2424 /* DECL is an explicit specialization. Replicate default arguments
2425 from the template it specializes. (That way, code like:
2427 template <class T> void f(T = 3);
2428 template <> void f(double);
2429 void g () { f (); }
2431 works, as required.) An alternative approach would be to look up
2432 the correct default arguments at the call-site, but this approach
2433 is consistent with how implicit instantiations are handled. */
2435 static void
2437 {
2438 tree tmpl;
2439 tree spec_types;
2440 tree tmpl_types;
2441 tree new_spec_types;
2442 tree old_type;
2443 tree new_type;
2444 tree t;
2449 /* See if there's anything we need to do. */
2462 {
2463 /* Remove the this pointer, but remember the object's type for
2464 CV quals. */
2470 {
2471 /* DECL may contain more parameters than TMPL due to the extra
2472 in-charge parameter in constructors and destructors. */
2475 }
2477 {
2480 }
2481 }
2483 /* Compute the merged default arguments. */
2484 new_spec_types =
2487 /* Compute the new FUNCTION_TYPE. */
2489 {
2493 new_spec_types);
2496 /* Put the in-charge parameter back. */
2499 new_spec_types);
2503 new_spec_types);
2504 }
2505 else
2507 new_spec_types);
2517 }
2519 /* Return the number of template headers we expect to see for a definition
2520 or specialization of CTYPE or one of its non-template members. */
2522 int
2524 {
2528 {
2529 /* You're supposed to have one `template <...>' for every
2530 template class, but you don't need one for a full
2531 specialization. For example:
2533 template <class T> struct S{};
2534 template <> struct S<int> { void f(); };
2535 void S<int>::f () {}
2537 is correct; there shouldn't be a `template <>' for the
2538 definition of `S<int>::f'. */
2540 /* If CTYPE does not have template information of any
2541 kind, then it is not a template, nor is it nested
2542 within a template. */
2550 }
2553 }
2555 /* Do a simple sanity check on the template headers that precede the
2556 variable declaration DECL. */
2558 void
2560 {
2565 {
2568 "variable templates only available with "
2571 // Namespace-scope variable templates should have a template header.
2573 }
2575 {
2577 "too many template headers for %qD "
2583 "members of an explicitly specialized class are defined "
2585 }
2586 }
2588 /* An explicit specialization whose declarator-id or class-head-name is not
2589 qualified shall be declared in the nearest enclosing namespace of the
2590 template, or, if the namespace is inline (7.3.1), any namespace from its
2591 enclosing namespace set.
2593 If the name declared in the explicit instantiation is an unqualified name,
2594 the explicit instantiation shall appear in the namespace where its template
2595 is declared or, if that namespace is inline (7.3.1), any namespace from its
2596 enclosing namespace set. */
2598 void
2600 {
2605 {
2611 /* This was allowed in C++98, so only pedwarn. */
2613 "outside its namespace must use a nested-name-"
2615 }
2616 }
2618 /* Check to see if the function just declared, as indicated in
2619 DECLARATOR, and in DECL, is a specialization of a function
2620 template. We may also discover that the declaration is an explicit
2621 instantiation at this point.
2623 Returns DECL, or an equivalent declaration that should be used
2624 instead if all goes well. Issues an error message if something is
2625 amiss. Returns error_mark_node if the error is not easily
2626 recoverable.
2628 FLAGS is a bitmask consisting of the following flags:
2630 2: The function has a definition.
2631 4: The function is a friend.
2633 The TEMPLATE_COUNT is the number of references to qualifying
2634 template classes that appeared in the name of the function. For
2635 example, in
2637 template <class T> struct S { void f(); };
2638 void S<int>::f();
2640 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2641 classes are not counted in the TEMPLATE_COUNT, so that in
2643 template <class T> struct S {};
2644 template <> struct S<int> { void f(); }
2645 template <> void S<int>::f();
2647 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2648 invalid; there should be no template <>.)
2650 If the function is a specialization, it is marked as such via
2651 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2652 is set up correctly, and it is added to the list of specializations
2653 for that template. */
2655 tree
2657 tree decl,
2660 {
2669 tmpl_spec_kind tsk;
2672 {
2675 else
2677 }
2678 else
2682 {
2685 {
2688 }
2690 {
2692 /* This could be something like:
2694 template <class T> void f(T);
2695 class S { friend void f<>(int); } */
2697 else
2698 {
2699 /* This case handles bogus declarations like template <>
2700 template <class T> void f<int>(); */
2703 declarator);
2705 }
2706 }
2710 /* The error has already been reported in
2711 check_specialization_scope. */
2717 /* Fall through. */
2730 decl);
2733 else
2737 /* Fall through. */
2743 /* In cases like template<> constexpr bool v = true;
2744 We'll give an error in check_template_variable. */
2750 else
2756 {
2757 /* This case handles bogus declarations like template <>
2758 template <class T> void f<int>(); */
2762 declarator);
2764 {
2765 /* Partial specialization of variable template. */
2769 }
2773 else
2777 ok:;
2778 }
2781 /* This is a specialization of a member template, without
2782 specialization the containing class. Something like:
2784 template <class T> struct S {
2785 template <class U> void f (U);
2786 };
2787 template <> template <class U> void S<int>::f(U) {}
2789 That's a specialization -- but of the entire template. */
2795 }
2798 /* This doesn't apply to variable templates. */
2801 {
2805 {
2809 }
2810 }
2813 {
2818 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2820 {
2821 tree fns;
2826 else
2827 {
2828 /* If there is no class context, the explicit instantiation
2829 must be at namespace scope. */
2832 /* Find the namespace binding, using the declaration
2833 context. */
2837 /* If lookup fails, look for a friend declaration so we can
2838 give a better diagnostic. */
2844 {
2847 }
2848 }
2851 }
2857 {
2859 /* A specialization in class scope. This is invalid,
2860 but the error will already have been flagged by
2861 check_specialization_scope. */
2863 else
2864 {
2865 /* It's not valid to write an explicit instantiation in
2866 class scope, e.g.:
2868 class C { template void f(); }
2870 This case is caught by the parser. However, on
2871 something like:
2873 template class C { void f(); };
2875 (which is invalid) we can get here. The error will be
2876 issued later. */
2877 ;
2878 }
2881 }
2884 {
2885 // We'll match variable templates in start_decl.
2889 /* Find the list of functions in ctype that have the same
2890 name as the declared function. */
2894 {
2898 {
2899 /* From [temp.expl.spec]:
2901 If such an explicit specialization for the member
2902 of a class template names an implicitly-declared
2903 special member function (clause _special_), the
2904 program is ill-formed.
2906 Similar language is found in [temp.explicit]. */
2909 }
2912 }
2914 /* For a type-conversion operator, We might be looking for
2915 `operator int' which will be a specialization of
2916 `operator T'. Grab all the conversion operators, and
2917 then select from them. */
2923 {
2926 }
2927 else
2929 }
2931 /* Figure out what exactly is being specialized at this point.
2932 Note that for an explicit instantiation, even one for a
2933 member function, we cannot tell a priori whether the
2934 instantiation is for a member template, or just a member
2935 function of a template class. Even if a member template is
2936 being instantiated, the member template arguments may be
2937 elided if they can be deduced from the rest of the
2938 declaration. */
2941 member_specialization,
2942 template_count,
2943 tsk);
2946 /* We couldn't figure out what this declaration was
2947 specializing. */
2949 else
2950 {
2953 {
2955 "friend declaration %qD is not visible to "
2959 }
2967 {
2968 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2969 is done by do_decl_instantiation later. */
2975 {
2976 /* If TMPL is not the most general template (for
2977 example, if TMPL is a friend template that is
2978 injected into namespace scope), then there will
2979 be too many levels of TARGS. Remove some of them
2980 here. */
2982 tree new_targs;
2989 }
2992 }
2994 /* If we thought that the DECL was a member function, but it
2995 turns out to be specializing a static member function,
2996 make DECL a static member function as well. */
3002 /* If this is a specialization of a member template of a
3003 template class, we want to return the TEMPLATE_DECL, not
3004 the specialization of it. */
3006 {
3011 {
3012 tree parm;
3016 /* We want to use the argument list specified in the
3017 definition, not in the original declaration. */
3022 }
3025 }
3027 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3033 /* Inherit default function arguments from the template
3034 DECL is specializing. */
3038 /* This specialization has the same protection as the
3039 template it specializes. */
3043 /* 7.1.1-1 [dcl.stc]
3045 A storage-class-specifier shall not be specified in an
3046 explicit specialization...
3048 The parser rejects these, so unless action is taken here,
3049 explicit function specializations will always appear with
3050 global linkage.
3052 The action recommended by the C++ CWG in response to C++
3053 defect report 605 is to make the storage class and linkage
3054 of the explicit specialization match the templated function:
3056 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3057 */
3059 {
3063 /* A concept cannot be specialized. */
3065 {
3067 gen_tmpl);
3069 }
3071 /* This specialization has the same linkage and visibility as
3072 the function template it specializes. */
3075 {
3078 }
3081 {
3084 }
3085 }
3087 /* If DECL is a friend declaration, declared using an
3088 unqualified name, the namespace associated with DECL may
3089 have been set incorrectly. For example, in:
3091 template <typename T> void f(T);
3092 namespace N {
3093 struct S { friend void f<int>(int); }
3094 }
3096 we will have set the DECL_CONTEXT for the friend
3097 declaration to N, rather than to the global namespace. */
3102 /* This is not really a declaration of a specialization.
3103 It's just the name of an instantiation. But, it's not
3104 a request for an instantiation, either. */
3107 /* A specialization is not necessarily COMDAT. */
3113 /* If this is a full specialization, register it so that we can find
3114 it again. Partial specializations will be registered in
3115 process_partial_specialization. */
3120 /* A 'structor should already have clones. */
3126 }
3127 }
3130 }
3132 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3133 parameters. These are represented in the same format used for
3134 DECL_TEMPLATE_PARMS. */
3136 int
3138 {
3139 const_tree p1;
3140 const_tree p2;
3148 {
3160 {
3164 /* If either of the template parameters are invalid, assume
3165 they match for the sake of error recovery. */
3178 }
3179 }
3182 /* One set of parameters has more parameters lists than the
3183 other. */
3187 }
3189 /* Determine whether PARM is a parameter pack. */
3191 bool
3193 {
3194 /* Determine if we have a non-type template parameter pack. */
3201 /* If this is a list of template parameters, we could get a
3202 TYPE_DECL or a TEMPLATE_DECL. */
3206 /* Otherwise it must be a type template parameter. */
3210 }
3212 /* Determine if T is a function parameter pack. */
3214 bool
3216 {
3220 }
3222 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3223 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3225 tree
3227 {
3234 }
3236 /* Return true iff the function parameter PARAM_DECL was expanded
3237 from the function parameter pack PACK. */
3239 bool
3241 {
3246 /* The parameter pack and its pack arguments have the same
3247 DECL_PARM_INDEX. */
3249 }
3251 /* Determine whether ARGS describes a variadic template args list,
3252 i.e., one that is terminated by a template argument pack. */
3254 static bool
3256 {
3258 tree last_parm;
3272 }
3274 /* Generate a new name for the parameter pack name NAME (an
3275 IDENTIFIER_NODE) that incorporates its */
3277 static tree
3279 {
3280 /* Munge the name to include the parameter index. */
3281 #define NUMBUF_LEN 128
3295 }
3297 /* Return true if T is a primary function, class or alias template
3298 instantiation. */
3300 bool
3302 {
3316 }
3318 /* Return true if PARM is a template template parameter. */
3320 bool
3322 {
3324 }
3326 /* Return true iff PARM is a DECL representing a type template
3327 parameter. */
3329 bool
3331 {
3336 }
3338 /* Return the template parameters of T if T is a
3339 primary template instantiation, NULL otherwise. */
3341 tree
3343 {
3348 parms = INNERMOST_TEMPLATE_PARMS
3352 }
3354 /* Return the template parameters of the LEVELth level from the full list
3355 of template parameters PARMS. */
3357 tree
3359 {
3360 tree p;
3371 }
3373 /* Returns the template arguments of T if T is a template instantiation,
3374 NULL otherwise. */
3376 tree
3378 {
3386 }
3388 /* Return the argument pack elements of T if T is a template argument pack,
3389 NULL otherwise. */
3391 tree
3393 {
3399 }
3401 /* True iff FN is a function representing a built-in variadic parameter
3402 pack. */
3404 bool
3406 {
3416 }
3418 /* True iff CALL is a call to a function representing a built-in variadic
3419 parameter pack. */
3421 static bool
3423 {
3427 }
3429 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3431 static tree
3433 tree in_decl)
3434 {
3440 {
3442 {
3445 }
3450 }
3451 else
3452 {
3456 /* Calculate the largest value of len that won't make the size of the vec
3457 overflow an int. The compiler will exceed resource limits long before
3458 this, but it seems a decent place to diagnose. */
3462 {
3467 }
3475 }
3476 }
3478 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3479 CALL. */
3481 static tree
3483 tree in_decl)
3484 {
3494 }
3496 /* Structure used to track the progress of find_parameter_packs_r. */
3497 struct find_parameter_pack_data
3498 {
3499 /* TREE_LIST that will contain all of the parameter packs found by
3500 the traversal. */
3503 /* Set of AST nodes that have been visited by the traversal. */
3506 /* True iff we're making a type pack expansion. */
3508 };
3510 /* Identifies all of the argument packs that occur in a template
3511 argument and appends them to the TREE_LIST inside DATA, which is a
3512 find_parameter_pack_data structure. This is a subroutine of
3513 make_pack_expansion and uses_parameter_packs. */
3514 static tree
3516 {
3522 /* Handle type aliases/typedefs. */
3524 {
3531 }
3533 /* Identify whether this is a parameter pack or not. */
3535 {
3543 /* FALLTHRU */
3545 /* If the placeholder appears in the decl-specifier-seq of a function
3546 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3547 is a pack expansion, the invented template parameter is a template
3548 parameter pack. */
3558 {
3559 /* We don't want to walk into the type of a PARM_DECL,
3560 because we don't want to see the type parameter pack. */
3563 }
3566 /* Look through a lambda capture proxy to the field pack. */
3569 {
3575 }
3577 {
3579 find_parameter_packs_r,
3582 }
3594 /* Not a parameter pack. */
3596 }
3599 {
3600 /* Add this parameter pack to the list. */
3602 }
3608 /* This switch statement will return immediately if we don't find a
3609 parameter pack. */
3611 {
3616 /* Check the template itself. */
3619 /* Check the template arguments. */
3633 /* Ignore the declaration of a capture proxy for a parameter pack. */
3641 /* Fall through. */
3686 {
3692 }
3695 {
3696 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3697 type_pack_expansion_p to false so that any placeholders
3698 within the expression don't get marked as parameter packs. */
3706 }
3710 }
3713 }
3715 /* Determines if the expression or type T uses any parameter packs. */
3716 bool
3718 {
3727 }
3729 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3730 representation a base-class initializer into a parameter pack
3731 expansion. If all goes well, the resulting node will be an
3732 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3733 respectively. */
3734 tree
3736 {
3737 tree result;
3746 {
3747 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3748 class initializer. In this case, the TREE_PURPOSE will be a
3749 _TYPE node (representing the base class expansion we're
3750 initializing) and the TREE_VALUE will be a TREE_LIST
3751 containing the initialization arguments.
3753 The resulting expansion looks somewhat different from most
3754 expansions. Rather than returning just one _EXPANSION, we
3755 return a TREE_LIST whose TREE_PURPOSE is a
3756 TYPE_PACK_EXPANSION containing the bases that will be
3757 initialized. The TREE_VALUE will be identical to the
3758 original TREE_VALUE, which is a list of arguments that will
3759 be passed to each base. We do not introduce any new pack
3760 expansion nodes into the TREE_VALUE (although it is possible
3761 that some already exist), because the TREE_PURPOSE and
3762 TREE_VALUE all need to be expanded together with the same
3763 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3764 resulting TREE_PURPOSE will mention the parameter packs in
3765 both the bases and the arguments to the bases. */
3766 tree purpose;
3767 tree value;
3770 /* Determine which parameter packs will be used by the base
3771 class expansion. */
3780 {
3784 }
3787 {
3788 /* Collect the sets of parameter packs used in each of the
3789 initialization arguments. */
3791 {
3792 /* Determine which parameter packs will be expanded in this
3793 argument. */
3796 }
3797 }
3801 /* Create the pack expansion type for the base type. */
3807 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3808 they will rarely be compared to anything. */
3812 }
3817 /* Build the PACK_EXPANSION_* node. */
3818 result = for_types
3823 {
3824 /* Propagate type and const-expression information. */
3827 /* Mark this read now, since the expansion might be length 0. */
3829 }
3830 else
3831 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3832 they will rarely be compared to anything. */
3835 /* Determine which parameter packs will be expanded. */
3842 /* Make sure we found some parameter packs. */
3844 {
3847 else
3850 }
3856 }
3858 /* Checks T for any "bare" parameter packs, which have not yet been
3859 expanded, and issues an error if any are found. This operation can
3860 only be done on full expressions or types (e.g., an expression
3861 statement, "if" condition, etc.), because we could have expressions like:
3863 foo(f(g(h(args)))...)
3865 where "args" is a parameter pack. check_for_bare_parameter_packs
3866 should not be called for the subexpressions args, h(args),
3867 g(h(args)), or f(g(h(args))), because we would produce erroneous
3868 error messages.
3870 Returns TRUE and emits an error if there were bare parameter packs,
3871 returns FALSE otherwise. */
3872 bool
3874 {
3881 /* A lambda might use a parameter pack from the containing context. */
3895 {
3899 {
3910 else
3915 else
3919 }
3922 }
3925 }
3927 /* Expand any parameter packs that occur in the template arguments in
3928 ARGS. */
3929 tree
3931 {
3940 /* First, determine if we need to expand anything, and the number of
3941 slots we'll need. */
3943 {
3948 {
3952 else
3954 }
3955 else
3956 {
3958 num_result_args++;
3959 }
3960 }
3962 /* If no expansion is necessary, we're done. */
3966 /* Expand arguments. */
3969 non_default_args_count =
3972 {
3975 {
3982 }
3983 else
3984 {
3987 }
3988 }
3992 }
3994 /* Checks if DECL shadows a template parameter.
3996 [temp.local]: A template-parameter shall not be redeclared within its
3997 scope (including nested scopes).
3999 Emits an error and returns TRUE if the DECL shadows a parameter,
4000 returns FALSE otherwise. */
4002 bool
4004 {
4005 tree olddecl;
4007 /* If we're not in a template, we can't possibly shadow a template
4008 parameter. */
4012 /* Figure out what we're shadowing. */
4016 /* If there's no previous binding for this name, we're not shadowing
4017 anything, let alone a template parameter. */
4021 /* If we're not shadowing a template parameter, we're done. Note
4022 that OLDDECL might be an OVERLOAD (or perhaps even an
4023 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4024 node. */
4028 /* We check for decl != olddecl to avoid bogus errors for using a
4029 name inside a class. We check TPFI to avoid duplicate errors for
4030 inline member templates. */
4036 /* Don't complain about the injected class name, as we've already
4037 complained about the class itself. */
4044 else
4049 }
4051 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4052 ORIG_LEVEL, DECL, and TYPE. */
4054 static tree
4058 tree decl,
4059 tree type)
4060 {
4071 }
4073 /* Find the canonical type parameter for the given template type
4074 parameter. Returns the canonical type parameter, which may be TYPE
4075 if no such parameter existed. */
4077 static tree
4079 {
4080 tree list;
4094 else
4095 {
4099 }
4100 }
4102 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4103 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4104 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4105 new one is created. */
4107 static tree
4109 tsubst_flags_t complain)
4110 {
4115 {
4134 /* Template template parameters need this. */
4136 {
4143 }
4144 }
4147 }
4149 /* Process information from new template parameter PARM and append it
4150 to the LIST being built. This new parameter is a non-type
4151 parameter iff IS_NON_TYPE is true. This new parameter is a
4152 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4153 is in PARM_LOC. */
4155 tree
4158 {
4167 {
4171 {
4175 else
4177 }
4180 }
4183 {
4189 {
4190 /* [temp.param]
4192 The top-level cv-qualifiers on the template-parameter are
4193 ignored when determining its type. */
4198 && !is_parameter_pack
4199 /* If we're in a nested template parameter list, the template
4200 template parameter could be a parameter pack. */
4202 {
4203 /* This template parameter is not a parameter pack, but it
4204 should be. Complain about "bare" parameter packs. */
4207 /* Recover by calling this a parameter pack. */
4209 }
4210 }
4212 /* A template parameter is not modifiable. */
4221 processing_template_decl,
4226 }
4227 else
4228 {
4229 tree t;
4233 {
4235 /* This is for distinguishing between real templates and template
4236 template parameters */
4240 }
4241 else
4242 {
4244 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4247 }
4254 processing_template_decl,
4258 }
4262 /* Build requirements for the type/template parameter.
4263 This must be done after SET_DECL_TEMPLATE_PARM_P or
4264 process_template_parm could fail. */
4269 /* Build the parameter node linking the parameter declaration,
4270 its default argument (if any), and its constraints (if any). */
4275 }
4277 /* The end of a template parameter list has been reached. Process the
4278 tree list into a parameter vector, converting each parameter into a more
4279 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4280 as PARM_DECLs. */
4282 tree
4284 {
4289 /* Pop the dummy parameter level and add the real one. */
4292 current_template_parms
4297 {
4301 }
4306 }
4308 // Explicitly indicate the end of the template parameter list. We assume
4309 // that the current template parameters have been constructed and/or
4310 // managed explicitly, as when creating new template template parameters
4311 // from a shorthand constraint.
4312 void
4314 {
4316 }
4318 /* end_template_decl is called after a template declaration is seen. */
4320 void
4322 {
4328 /* This matches the pushlevel in begin_template_parm_list. */
4333 }
4335 /* Takes a TREE_LIST representing a template parameter and convert it
4336 into an argument suitable to be passed to the type substitution
4337 functions. Note that If the TREE_LIST contains an error_mark
4338 node, the returned argument is error_mark_node. */
4340 tree
4342 {
4355 {
4359 {
4360 /* Turn this argument into a TYPE_ARGUMENT_PACK
4361 with a single element, which expands T. */
4370 }
4371 }
4372 else
4373 {
4377 {
4378 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4379 with a single element, which expands T. */
4389 }
4390 else
4392 }
4394 }
4396 /* Given a single level of template parameters (a TREE_VEC), return it
4397 as a set of template arguments. */
4399 static tree
4401 {
4411 }
4413 /* Given a set of template parameters, return them as a set of template
4414 arguments. The template parameters are represented as a TREE_VEC, in
4415 the form documented in cp-tree.h for template arguments. */
4417 static tree
4419 {
4420 tree header;
4425 /* If there is only one level of template parameters, we do not
4426 create a TREE_VEC of TREE_VECs. Instead, we return a single
4427 TREE_VEC containing the arguments. */
4432 {
4437 else
4439 }
4442 }
4444 /* Within the declaration of a template, return the currently active
4445 template parameters as an argument TREE_VEC. */
4447 static tree
4449 {
4451 }
4453 /* Update the declared TYPE by doing any lookups which were thought to be
4454 dependent, but are not now that we know the SCOPE of the declarator. */
4456 tree
4458 {
4469 /* Don't bother building up the args in this case. */
4471 {
4472 /* tsubst in the args corresponding to the template parameters,
4473 including auto if present. Most things will be unchanged, but
4474 make_typename_type and tsubst_qualified_id will resolve
4475 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4478 tree pushed;
4480 {
4484 }
4489 }
4495 {
4498 else
4500 }
4502 }
4504 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4505 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4506 the new template is a member template. */
4508 tree
4510 {
4518 }
4520 struct template_parm_data
4521 {
4522 /* The level of the template parameters we are currently
4523 processing. */
4526 /* The index of the specialization argument we are currently
4527 processing. */
4530 /* An array whose size is the number of template parameters. The
4531 elements are nonzero if the parameter has been used in any one
4532 of the arguments processed so far. */
4535 /* An array whose size is the number of template arguments. The
4536 elements are nonzero if the argument makes use of template
4537 parameters of this level. */
4539 };
4541 /* Subroutine of push_template_decl used to see if each template
4542 parameter in a partial specialization is used in the explicit
4543 argument list. If T is of the LEVEL given in DATA (which is
4544 treated as a template_parm_data*), then DATA->PARMS is marked
4545 appropriately. */
4547 static int
4549 {
4557 {
4560 }
4562 /* In C++17 the type of a non-type argument is a deduced context. */
4567 data,
4568 NULL,
4571 /* Return zero so that for_each_template_parm will continue the
4572 traversal of the tree; we want to mark *every* template parm. */
4574 }
4576 /* Process the partial specialization DECL. */
4578 static tree
4580 {
4587 tree inner_parms;
4588 tree inst;
4598 /* A concept cannot be specialized. */
4600 {
4603 }
4608 /* We check that each of the template parameters given in the
4609 partial specialization is used in the argument list to the
4610 specialization. For example:
4612 template <class T> struct S;
4613 template <class T> struct S<T*>;
4615 The second declaration is OK because `T*' uses the template
4616 parameter T, whereas
4618 template <class T> struct S<int>;
4620 is no good. Even trickier is:
4622 template <class T>
4623 struct S1
4624 {
4625 template <class U>
4626 struct S2;
4627 template <class U>
4628 struct S2<T>;
4629 };
4631 The S2<T> declaration is actually invalid; it is a
4632 full-specialization. Of course,
4634 template <class U>
4635 struct S2<T (*)(U)>;
4637 or some such would have been OK. */
4645 {
4650 NULL,
4652 }
4655 {
4656 /* One of the template parms was not used in a deduced context in the
4657 specialization. */
4659 {
4663 }
4667 }
4672 /* [temp.class.spec]
4674 The argument list of the specialization shall not be identical to
4675 the implicit argument list of the primary template. */
4676 tree main_args
4679 && (!flag_concepts
4682 {
4686 else
4690 }
4692 /* A partial specialization that replaces multiple parameters of the
4693 primary template with a pack expansion is less specialized for those
4694 parameters. */
4696 {
4698 "primary template because it replaces multiple parameters "
4701 /* Avoid crash in process_partial_specialization. */
4703 }
4705 /* If we aren't in a dependent class, we can actually try deduction. */
4707 /* FIXME we should be able to handle a partial specialization of a
4708 partial instantiation, but currently we can't (c++/41727). */
4711 {
4715 maintmpl);
4716 }
4718 /* [temp.class.spec]
4720 A partially specialized non-type argument expression shall not
4721 involve template parameters of the partial specialization except
4722 when the argument expression is a simple identifier.
4724 The type of a template parameter corresponding to a specialized
4725 non-type argument shall not be dependent on a parameter of the
4726 specialization.
4728 Also, we verify that pack expansions only occur at the
4729 end of the argument list. */
4733 {
4740 {
4741 /* Extract the arguments from the argument pack. We'll be
4742 iterating over these in the following loop. */
4745 }
4748 {
4750 /* Get the Jth argument in the parameter pack. */
4754 {
4755 /* Pack expansions must come at the end of the
4756 argument list. */
4759 {
4763 else
4766 }
4767 }
4770 /* We only care about the pattern. */
4776 /* This next two lines are the `argument expression is not just a
4777 simple identifier' condition and also the `specialized
4778 non-type argument' bit. */
4782 {
4786 arg);
4787 else
4788 {
4789 /* Look at the corresponding template parameter,
4790 marking which template parameters its type depends
4791 upon. */
4795 {
4796 /* We haven't yet initialized TPD2. Do so now. */
4798 /* The number of parameters here is the number in the
4799 main template, which, as checked in the assertion
4800 above, is NARGS. */
4804 }
4806 /* Mark the template parameters. But this time, we're
4807 looking for the template parameters of the main
4808 template, not in the specialization. */
4815 NULL,
4819 {
4820 /* The type depended on some template parameters.
4821 If they are fully specialized in the
4822 specialization, that's OK. */
4831 "type %qT of template argument %qE depends "
4833 "type %qT of template argument %qE depends "
4835 type,
4836 arg);
4837 }
4838 }
4839 }
4840 }
4841 }
4843 /* We should only get here once. */
4847 // Build the template decl.
4856 /* Give template template parms a DECL_CONTEXT of the template
4857 for which they are a parameter. */
4859 {
4863 }
4866 /* We didn't register this in check_explicit_specialization so we could
4867 wait until the constraints were set. */
4869 else
4879 {
4885 {
4893 "declaration of %qD ambiguates earlier template "
4897 "partial specialization of %qD after instantiation "
4899 }
4900 }
4903 }
4905 /* PARM is a template parameter of some form; return the corresponding
4906 TEMPLATE_PARM_INDEX. */
4908 static tree
4910 {
4923 }
4925 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4926 parameter packs used by the template parameter PARM. */
4928 static void
4930 {
4931 /* A type parm can't refer to another parm. */
4935 {
4939 }
4946 }
4948 /* PARM is a template parameter pack. Return any parameter packs used in
4949 its type or the type of any of its template parameters. If there are
4950 any such packs, it will be instantiated into a fixed template parameter
4951 list by partial instantiation rather than be fully deduced. */
4953 tree
4955 {
4956 /* This can only be true in a member template. */
4959 /* This can only be true for a parameter pack. */
4962 /* A type parm can't refer to another parm. */
4976 }
4978 /* Check that a template declaration's use of default arguments and
4979 parameter packs is not invalid. Here, PARMS are the template
4980 parameters. IS_PRIMARY is true if DECL is the thing declared by
4981 a primary template. IS_PARTIAL is true if DECL is a partial
4982 specialization.
4984 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4985 declaration (but not a definition); 1 indicates a declaration, 2
4986 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4987 emitted for extraneous default arguments.
4989 Returns TRUE if there were no errors found, FALSE otherwise. */
4991 bool
4994 {
4997 tree parm_level;
5000 /* [temp.param]
5002 A default template-argument shall not be specified in a
5003 function template declaration or a function template definition, nor
5004 in the template-parameter-list of the definition of a member of a
5005 class template. */
5009 /* You can't have a function template declaration in a local
5010 scope, nor you can you define a member of a class template in a
5011 local scope. */
5019 /* A lambda doesn't have an explicit declaration; don't complain
5020 about the parms of the enclosing class. */
5027 /* If this is either a friend defined in the scope of the class
5028 or a member function. */
5034 /* And, if it was a member function, it really was defined in
5035 the scope of the class. */
5038 /* We already checked these parameters when the template was
5039 declared, so there's no need to do it again now. This function
5040 was defined in class scope, but we're processing its body now
5041 that the class is complete. */
5044 /* Core issue 226 (C++0x only): the following only applies to class
5045 templates. */
5048 {
5049 /* [temp.param]
5051 If a template-parameter has a default template-argument, all
5052 subsequent template-parameters shall have a default
5053 template-argument supplied. */
5055 {
5062 {
5072 {
5074 /* For better subsequent error-recovery, we indicate that
5075 there should have been a default argument. */
5078 }
5080 && !is_friend_decl
5081 /* Don't complain about an enclosing partial
5082 specialization. */
5087 /* A fixed parameter pack will be partially
5088 instantiated into a fixed length list. */
5090 {
5091 /* A primary class template can only have one
5092 parameter pack, at the end of the template
5093 parameter list. */
5101 }
5102 }
5103 }
5104 }
5107 || is_partial
5108 || !is_primary
5110 /* For an ordinary class template, default template arguments are
5111 allowed at the innermost level, e.g.:
5112 template <class T = int>
5113 struct S {};
5114 but, in a partial specialization, they're not allowed even
5115 there, as we have in [temp.class.spec]:
5117 The template parameter list of a specialization shall not
5118 contain default template argument values.
5120 So, for a partial specialization, or for a function template
5121 (in C++98/C++03), we look at all of them. */
5122 ;
5123 else
5124 /* But, for a primary class template that is not a partial
5125 specialization we look at all template parameters except the
5126 innermost ones. */
5129 /* Figure out what error message to issue. */
5144 else
5145 /* Per [temp.param]/9, "A default template-argument shall not be
5146 specified in the template-parameter-lists of the definition of
5147 a member of a class template that appears outside of the member's
5148 class.", thus if we aren't handling a member of a class template
5149 there is no need to examine the parameters. */
5153 /* If we're inside a class definition, there's no need to
5154 examine the parameters to the class itself. On the one
5155 hand, they will be checked when the class is defined, and,
5156 on the other, default arguments are valid in things like:
5157 template <class T = double>
5158 struct S { template <class U> void f(U); };
5159 Here the default argument for `S' has no bearing on the
5160 declaration of `f'. */
5162 else
5163 /* Check everything. */
5169 {
5176 {
5181 {
5183 {
5190 }
5192 /* Clear out the default argument so that we are not
5193 confused later. */
5195 }
5196 }
5198 /* At this point, if we're still interested in issuing messages,
5199 they must apply to classes surrounding the object declared. */
5203 }
5206 }
5208 /* Worker for push_template_decl_real, called via
5209 for_each_template_parm. DATA is really an int, indicating the
5210 level of the parameters we are interested in. If T is a template
5211 parameter of that level, return nonzero. */
5213 static int
5215 {
5221 else
5224 }
5226 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5227 DATA is really an int, indicating the innermost outer level of parameters.
5228 If T is a template parameter of that level or further out, return
5229 nonzero. */
5231 static int
5233 {
5239 else
5242 }
5244 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5245 parameters given by current_template_args, or reuses a
5246 previously existing one, if appropriate. Returns the DECL, or an
5247 equivalent one, if it is replaced via a call to duplicate_decls.
5249 If IS_FRIEND is true, DECL is a friend declaration. */
5251 tree
5253 {
5254 tree tmpl;
5255 tree args;
5256 tree info;
5257 tree ctx;
5261 /* True if the template is a member template, in the sense of
5262 [temp.mem]. */
5268 /* See if this is a partial specialization. */
5281 /* For a friend, we want the context of the friend function, not
5282 the type of which it is a friend. */
5286 /* In the case of a virtual function, we want the class in which
5287 it is defined. */
5289 else
5290 /* Otherwise, if we're currently defining some class, the DECL
5291 is assumed to be a member of the class. */
5300 /* See if this is a primary template. */
5303 /* A friend template that specifies a class context, i.e.
5304 template <typename T> friend void A<T>::f();
5305 is not primary. */
5310 else
5314 {
5321 {
5324 }
5326 {
5328 {
5331 }
5333 {
5334 /* [temp.mem]
5336 A destructor shall not be a member template. */
5339 }
5346 {
5347 /* [basic.stc.dynamic.allocation]
5349 An allocation function can be a function
5350 template. ... Template allocation functions shall
5351 have two or more parameters. */
5354 }
5355 }
5358 {
5359 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5362 {
5368 }
5369 }
5372 /* alias-declaration */
5376 else
5377 {
5380 }
5381 }
5383 /* Check to see that the rules regarding the use of default
5384 arguments are not being violated. */
5388 /* Ensure that there are no parameter packs in the type of this
5389 declaration that have not been expanded. */
5391 {
5392 /* Check each of the arguments individually to see if there are
5393 any bare parameter packs. */
5399 {
5402 {
5403 /* This is a PARM_DECL that contains unexpanded parameter
5404 packs. We have already complained about this in the
5405 check_for_bare_parameter_packs call, so just replace
5406 these types with ERROR_MARK_NODE. */
5409 }
5413 }
5415 /* Check for bare parameter packs in the return type and the
5416 exception specifiers. */
5418 /* Errors were already issued, set return type to int
5419 as the frontend doesn't expect error_mark_node as
5420 the return type. */
5424 }
5429 {
5432 }
5445 {
5450 /* If DECL is a TYPE_DECL for a class-template, then there won't
5451 be DECL_LANG_SPECIFIC. The information equivalent to
5452 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5456 {
5457 /* Since a template declaration already existed for this
5458 class-type, we must be redeclaring it here. Make sure
5459 that the redeclaration is valid. */
5461 current_template_parms,
5463 /* We don't need to create a new TEMPLATE_DECL; just use the
5464 one we already had. */
5466 }
5467 else
5468 {
5470 member_template_p);
5475 {
5476 /* A specialization of a member template of a template
5477 class. */
5481 }
5482 }
5483 }
5484 else
5485 {
5491 {
5494 }
5502 {
5503 tree new_tmpl;
5505 /* The declaration is a specialization of a member
5506 template, declared outside the class. Therefore, the
5507 innermost template arguments will be NULL, so we
5508 replace them with the arguments determined by the
5509 earlier call to check_explicit_specialization. */
5512 new_tmpl
5514 member_template_p);
5524 args,
5527 }
5529 /* Make sure the template headers we got make sense. */
5534 {
5539 }
5540 else
5542 {
5547 {
5551 else
5555 /* Avoid crash in import_export_decl. */
5558 }
5563 /* Can happen in erroneous input. */
5565 else
5567 }
5569 /* Check that the parms are used in the appropriate qualifying scopes
5570 in the declarator. */
5574 {
5580 /* Avoid crash in import_export_decl. */
5583 }
5584 }
5589 /* Push template declarations for global functions and types. Note
5590 that we do not try to push a global template friend declared in a
5591 template class; such a thing may well depend on the template
5592 parameters of the class. */
5595 {
5600 /* Hide template friend classes that haven't been declared yet. */
5602 {
5605 }
5606 }
5609 {
5615 {
5618 /* It is a conversion operator. See if the type converted to
5619 depends on innermost template operands. */
5622 depth))
5624 }
5626 /* Give template template parms a DECL_CONTEXT of the template
5627 for which they are a parameter. */
5630 {
5634 }
5640 }
5642 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5643 back to its most general template. If TMPL is a specialization,
5644 ARGS may only have the innermost set of arguments. Add the missing
5645 argument levels if necessary. */
5653 else
5654 {
5659 }
5662 && !is_friend
5665 /* Set DECL_COMDAT on template instantiations; if we force
5666 them to be emitted by explicit instantiation or -frepo,
5667 mark_needed will tell cgraph to do the right thing. */
5671 }
5673 tree
5675 {
5677 }
5679 /* FN is an inheriting constructor that inherits from the constructor
5680 template INHERITED; turn FN into a constructor template with a matching
5681 template header. */
5683 tree
5685 {
5686 tree inner_parms
5689 tree parms
5700 }
5702 /* Called when a class template TYPE is redeclared with the indicated
5703 template PARMS, e.g.:
5705 template <class T> struct S;
5706 template <class T> struct S {}; */
5708 bool
5710 {
5711 tree tmpl;
5712 tree tmpl_parms;
5716 {
5719 }
5723 /* The type is nested in some template class. Nothing to worry
5724 about here; there are no new template parameters for the nested
5725 type. */
5729 {
5731 tmpl);
5733 }
5739 {
5749 }
5752 {
5753 tree tmpl_parm;
5754 tree parm;
5755 tree tmpl_default;
5756 tree parm_default;
5770 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5771 TEMPLATE_DECL. */
5781 {
5785 }
5788 {
5789 /* We have in [temp.param]:
5791 A template-parameter may not be given default arguments
5792 by two different declarations in the same scope. */
5797 }
5800 /* Update the previous template parameters (which are the ones
5801 that will really count) with the new default value. */
5804 /* Update the new parameters, too; they'll be used as the
5805 parameters for any members. */
5808 /* Give each template template parm in this redeclaration a
5809 DECL_CONTEXT of the template for which they are a parameter. */
5811 {
5814 }
5818 }
5820 // Cannot redeclare a class template with a different set of constraints.
5822 {
5827 }
5830 }
5832 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5833 to be used when the caller has already checked
5834 (processing_template_decl
5835 && !instantiation_dependent_expression_p (expr)
5836 && potential_constant_expression (expr))
5837 and cleared processing_template_decl. */
5839 tree
5841 {
5844 complain,
5848 }
5850 /* Simplify EXPR if it is a non-dependent expression. Returns the
5851 (possibly simplified) expression. */
5853 tree
5855 {
5859 /* If we're in a template, but EXPR isn't value dependent, simplify
5860 it. We're supposed to treat:
5862 template <typename T> void f(T[1 + 1]);
5863 template <typename T> void f(T[2]);
5865 as two declarations of the same function, for example. */
5868 {
5869 processing_template_decl_sentinel s;
5871 }
5873 }
5875 tree
5877 {
5879 }
5881 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5882 an uninstantiated expression. */
5884 tree
5886 {
5890 {
5893 else
5894 {
5895 processing_template_decl_sentinel s;
5897 }
5898 }
5900 }
5902 /* True iff T is a specialization of a variable template. */
5904 bool
5906 {
5911 }
5913 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5914 template declaration, or a TYPE_DECL for an alias declaration. */
5916 bool
5918 {
5926 }
5928 /* Return TRUE iff T is a specialization of an alias template. */
5930 bool
5932 {
5933 /* It's an alias template specialization if it's an alias and its
5934 TYPE_NAME is a specialization of a primary template. */
5940 }
5942 /* An alias template is complex from a SFINAE perspective if a template-id
5943 using that alias can be ill-formed when the expansion is not, as with
5944 the void_t template. We determine this by checking whether the
5945 expansion for the alias template uses all its template parameters. */
5947 struct uses_all_template_parms_data
5948 {
5951 };
5953 static int
5955 {
5963 }
5965 static bool
5967 {
5982 }
5984 /* Return TRUE iff T is a specialization of a complex alias template with
5985 dependent template-arguments. */
5987 bool
5989 {
6002 }
6004 /* Return the number of innermost template parameters in TMPL. */
6006 static int
6008 {
6011 }
6013 /* Return either TMPL or another template that it is equivalent to under DR
6014 1286: An alias that just changes the name of a template is equivalent to
6015 the other template. */
6017 static tree
6019 {
6022 {
6023 /* Determine if the alias is equivalent to an underlying template. */
6035 tree alias_args = INNERMOST_TEMPLATE_ARGS
6040 /* Alias is equivalent. Strip it and repeat. */
6042 }
6045 }
6047 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6048 must be a reference-to-function or a pointer-to-function type, as specified
6049 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6050 and check that the resulting function has external linkage. */
6052 static tree
6054 tsubst_flags_t complain)
6055 {
6058 linkage_kind linkage;
6073 /* [temp.arg.nontype]/1
6075 A template-argument for a non-type, non-template template-parameter
6076 shall be one of:
6077 [...]
6078 -- the address of an object or function with external [C++11: or
6079 internal] linkage. */
6082 {
6084 {
6090 else
6093 }
6095 }
6099 {
6101 {
6106 else
6110 }
6112 }
6114 accept:
6121 }
6123 /* Subroutine of convert_nontype_argument.
6124 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6125 Emit an error otherwise. */
6127 static bool
6129 tsubst_flags_t complain)
6130 {
6147 {
6152 else
6154 }
6156 }
6158 /* Returns TRUE iff the address of OP is value-dependent.
6160 14.6.2.4 [temp.dep.temp]:
6161 A non-integral non-type template-argument is dependent if its type is
6162 dependent or it has either of the following forms
6163 qualified-id
6164 & qualified-id
6165 and contains a nested-name-specifier which specifies a class-name that
6166 names a dependent type.
6168 We generalize this to just say that the address of a member of a
6169 dependent class is value-dependent; the above doesn't cover the
6170 address of a static data member named with an unqualified-id. */
6172 static bool
6174 {
6175 /* We could use get_inner_reference here, but there's no need;
6176 this is only relevant for template non-type arguments, which
6177 can only be expressed as &id-expression. */
6179 {
6183 }
6186 }
6188 /* The next set of functions are used for providing helpful explanatory
6189 diagnostics for failed overload resolution. Their messages should be
6190 indented by two spaces for consistency with the messages in
6191 call.c */
6193 static int
6195 {
6197 }
6199 /* Other failure functions should call this one, to provide a single function
6200 for setting a breakpoint on. */
6202 static int
6204 {
6206 }
6208 static int
6210 {
6215 }
6217 static int
6219 {
6225 }
6227 static int
6229 {
6233 }
6235 static int
6237 {
6240 " template parameter %qD is not a parameter pack, but "
6244 }
6246 static int
6248 {
6251 " template argument %qE does not match "
6255 }
6257 static int
6259 {
6263 }
6265 static int
6267 {
6273 }
6275 static int
6277 {
6279 {
6284 else
6286 " deduced conflicting values for non-type parameter "
6288 }
6290 }
6292 static int
6294 {
6297 " variable-sized array type %qT is not "
6299 arg);
6301 }
6303 static int
6305 {
6309 arg);
6311 }
6313 static int
6315 {
6317 {
6323 else
6328 }
6330 }
6332 static int
6334 {
6336 }
6338 static int
6341 {
6343 }
6345 static int
6348 {
6354 }
6356 static int
6359 {
6362 {
6370 }
6372 }
6374 static int
6376 {
6379 " template parameters of a template template argument are "
6382 }
6384 static int
6386 {
6392 }
6394 static int
6396 {
6401 }
6403 static int
6405 {
6409 arg);
6411 }
6413 /* Attempt to convert the non-type template parameter EXPR to the
6414 indicated TYPE. If the conversion is successful, return the
6415 converted value. If the conversion is unsuccessful, return
6416 NULL_TREE if we issued an error message, or error_mark_node if we
6417 did not. We issue error messages for out-and-out bad template
6418 parameters, but not simply because the conversion failed, since we
6419 might be just trying to do argument deduction. Both TYPE and EXPR
6420 must be non-dependent.
6422 The conversion follows the special rules described in
6423 [temp.arg.nontype], and it is much more strict than an implicit
6424 conversion.
6426 This function is called twice for each template argument (see
6427 lookup_template_class for a more accurate description of this
6428 problem). This means that we need to handle expressions which
6429 are not valid in a C++ source, but can be created from the
6430 first call (for instance, casts to perform conversions). These
6431 hacks can go away after we fix the double coercion problem. */
6433 static tree
6435 {
6436 tree expr_type;
6440 /* Detect immediately string literals as invalid non-type argument.
6441 This special-case is not needed for correctness (we would easily
6442 catch this later), but only to provide better diagnostic for this
6443 common user mistake. As suggested by DR 100, we do not mention
6444 linkage issues in the diagnostic as this is not the point. */
6445 /* FIXME we're making this OK. */
6447 {
6453 }
6455 /* Add the ADDR_EXPR now for the benefit of
6456 value_dependent_expression_p. */
6459 {
6463 }
6465 /* If we are in a template, EXPR may be non-dependent, but still
6466 have a syntactic, rather than semantic, form. For example, EXPR
6467 might be a SCOPE_REF, rather than the VAR_DECL to which the
6468 SCOPE_REF refers. Preserving the qualifying scope is necessary
6469 so that access checking can be performed when the template is
6470 instantiated -- but here we need the resolved form so that we can
6471 convert the argument. */
6483 /* If the argument is non-dependent, perform any conversions in
6484 non-dependent context as well. */
6492 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6493 to a non-type argument of "nullptr". */
6497 /* In C++11, integral or enumeration non-type template arguments can be
6498 arbitrary constant expressions. Pointer and pointer to
6499 member arguments can be general constant expressions that evaluate
6500 to a null value, but otherwise still need to be of a specific form. */
6502 {
6504 /* A PTRMEM_CST is already constant, and a valid template
6505 argument for a parameter of pointer to member type, we just want
6506 to leave it in that form rather than lower it to a
6510 {
6511 /* C++17: A template-argument for a non-type template-parameter shall
6512 be a converted constant expression (8.20) of the type of the
6513 template-parameter. */
6519 }
6521 {
6526 }
6527 }
6531 else
6534 /* HACK: Due to double coercion, we can get a
6535 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6536 which is the tree that we built on the first call (see
6537 below when coercing to reference to object or to reference to
6538 function). We just strip everything and get to the arg.
6539 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6540 for examples. */
6542 {
6548 {
6549 /* ??? Maybe we could use convert_from_reference here, but we
6550 would need to relax its constraints because the NOP_EXPR
6551 could actually change the type to something more cv-qualified,
6552 and this is not folded by convert_from_reference. */
6557 && (same_type_ignoring_top_level_qualifiers_p
6560 {
6563 }
6564 }
6565 }
6567 /* [temp.arg.nontype]/5, bullet 1
6569 For a non-type template-parameter of integral or enumeration type,
6570 integral promotions (_conv.prom_) and integral conversions
6571 (_conv.integral_) are applied. */
6573 {
6575 {
6580 }
6585 /* Notice that there are constant expressions like '4 % 0' which
6586 do not fold into integer constants. */
6589 {
6591 {
6595 else
6601 /* else cxx_constant_value complained but gave us
6602 a real constant, so go ahead. */
6604 }
6605 else
6607 }
6609 /* Avoid typedef problems. */
6612 }
6613 /* [temp.arg.nontype]/5, bullet 2
6615 For a non-type template-parameter of type pointer to object,
6616 qualification conversions (_conv.qual_) and the array-to-pointer
6617 conversion (_conv.array_) are applied. */
6619 {
6622 /* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
6623 decay_conversion or an explicit cast. If it's a problematic cast,
6624 we'll complain about it below. */
6626 {
6631 {
6634 }
6635 }
6637 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6639 A template-argument for a non-type, non-template template-parameter
6640 shall be one of: [...]
6642 -- the name of a non-type template-parameter;
6643 -- the address of an object or function with external linkage, [...]
6644 expressed as "& id-expression" where the & is optional if the name
6645 refers to a function or array, or if the corresponding
6646 template-parameter is a reference.
6648 Here, we do not care about functions, as they are invalid anyway
6649 for a parameter of type pointer-to-object. */
6652 /* Non-type template parameters are OK. */
6653 ;
6657 {
6659 {
6662 "because %qD is a variable, not the address of "
6665 }
6667 {
6673 }
6674 /* Other values, like integer constants, might be valid
6675 non-type arguments of some other type. */
6677 }
6678 else
6679 {
6683 {
6688 }
6690 {
6696 }
6699 {
6704 }
6705 /* C++17: For a non-type template-parameter of reference or pointer
6706 type, the value of the constant expression shall not refer to (or
6707 for a pointer type, shall not be the address of):
6708 * a subobject (4.5),
6709 * a temporary object (15.2),
6710 * a string literal (5.13.5),
6711 * the result of a typeid expression (8.2.8), or
6712 * a predefined __func__ variable (11.4.1). */
6714 {
6717 decl);
6719 }
6723 {
6728 }
6730 {
6734 decl);
6736 }
6737 }
6744 }
6745 /* [temp.arg.nontype]/5, bullet 3
6747 For a non-type template-parameter of type reference to object, no
6748 conversions apply. The type referred to by the reference may be more
6749 cv-qualified than the (otherwise identical) type of the
6750 template-argument. The template-parameter is bound directly to the
6751 template-argument, which must be an lvalue. */
6753 {
6755 expr_type))
6759 {
6764 }
6767 {
6772 }
6774 /* [temp.arg.nontype]/1
6776 A template-argument for a non-type, non-template template-parameter
6777 shall be one of: [...]
6779 -- the address of an object or function with external linkage. */
6782 {
6785 {
6788 "because a reference variable does not have a constant "
6791 }
6792 }
6796 /* OK, dependent reference. We don't want to ask whether a DECL is
6798 else
6799 {
6801 {
6807 }
6809 /* DR 1155 allows internal linkage in C++11 and up. */
6812 {
6818 }
6821 }
6825 }
6826 /* [temp.arg.nontype]/5, bullet 4
6828 For a non-type template-parameter of type pointer to function, only
6829 the function-to-pointer conversion (_conv.func_) is applied. If the
6830 template-argument represents a set of overloaded functions (or a
6831 pointer to such), the matching function is selected from the set
6832 (_over.over_). */
6834 {
6835 /* If the argument is a template-id, we might not have enough
6836 context information to decay the pointer. */
6838 {
6842 }
6845 /* Null pointer values are OK in C++11. */
6851 }
6852 /* [temp.arg.nontype]/5, bullet 5
6854 For a non-type template-parameter of type reference to function, no
6855 conversions apply. If the template-argument represents a set of
6856 overloaded functions, the matching function is selected from the set
6857 (_over.over_). */
6859 {
6861 {
6863 {
6868 }
6870 }
6875 }
6876 /* [temp.arg.nontype]/5, bullet 6
6878 For a non-type template-parameter of type pointer to member function,
6879 no conversions apply. If the template-argument represents a set of
6880 overloaded member functions, the matching member function is selected
6881 from the set (_over.over_). */
6883 {
6888 /* [temp.arg.nontype] bullet 1 says the pointer to member
6889 expression must be a pointer-to-member constant. */
6894 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6895 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6898 }
6899 /* [temp.arg.nontype]/5, bullet 7
6901 For a non-type template-parameter of type pointer to data member,
6902 qualification conversions (_conv.qual_) are applied. */
6904 {
6905 /* [temp.arg.nontype] bullet 1 says the pointer to member
6906 expression must be a pointer-to-member constant. */
6914 }
6916 {
6918 {
6923 }
6925 }
6926 /* A template non-type parameter must be one of the above. */
6927 else
6930 /* Sanity check: did we actually convert the argument to the
6931 right type? */
6935 }
6937 /* Subroutine of coerce_template_template_parms, which returns 1 if
6938 PARM_PARM and ARG_PARM match using the rule for the template
6939 parameters of template template parameters. Both PARM and ARG are
6940 template parameters; the rest of the arguments are the same as for
6941 coerce_template_template_parms.
6942 */
6943 static int
6945 tree arg,
6946 tsubst_flags_t complain,
6947 tree in_decl,
6948 tree outer_args)
6949 {
6958 {
6960 /* We encounter instantiations of templates like
6961 template <template <template <class> class> class TT>
6962 class C; */
6963 {
6970 }
6971 /* Fall through. */
6976 /* Argument is a parameter pack but parameter is not. */
6981 /* The tsubst call is used to handle cases such as
6983 template <int> class C {};
6984 template <class T, template <T> class TT> class D {};
6985 D<int, C> d;
6987 i.e. the parameter list of TT depends on earlier parameters. */
6989 {
6994 }
6998 /* Argument is a parameter pack but parameter is not. */
7005 }
7008 }
7010 /* Coerce template argument list ARGLIST for use with template
7011 template-parameter TEMPL. */
7013 static tree
7015 tsubst_flags_t complain)
7016 {
7017 /* Consider an example where a template template parameter declared as
7019 template <class T, class U = std::allocator<T> > class TT
7021 The template parameter level of T and U are one level larger than
7022 of TT. To proper process the default argument of U, say when an
7023 instantiation `TT<int>' is seen, we need to build the full
7024 arguments containing {int} as the innermost level. Outer levels,
7025 available when not appearing as default template argument, can be
7026 obtained from the arguments of the enclosing template.
7028 Suppose that TT is later substituted with std::vector. The above
7029 instantiation is `TT<int, std::allocator<T> >' with TT at
7030 level 1, and T at level 2, while the template arguments at level 1
7031 becomes {std::vector} and the inner level 2 is {int}. */
7035 {
7037 /* We want arguments for the partial specialization, not arguments for
7038 the primary template. */
7040 else
7042 }
7044 {
7045 /* This is an argument of the current template, so we haven't set
7046 DECL_CONTEXT yet. */
7047 tree relevant_template_parms;
7049 /* Parameter levels that are greater than the level of the given
7050 template template parm are irrelevant. */
7057 }
7064 complain,
7067 }
7069 /* A cache of template template parameters with match-all default
7070 arguments. */
7072 static void
7074 {
7078 }
7079 static tree
7081 {
7086 }
7088 /* T is a bound template template-parameter. Copy its arguments into default
7089 arguments of the template template-parameter's template parameters. */
7091 static tree
7093 {
7116 {
7119 {
7122 }
7123 }
7127 }
7129 /* ARG is a bound potential template template-argument, and PARGS is a list
7130 of arguments for the corresponding template template-parameter. Adjust
7131 PARGS as appropriate for application to ARG's template, and if ARG is a
7132 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7133 arguments to the template template parameter. */
7135 static tree
7137 {
7141 {
7142 /* When comparing two template template-parameters in partial ordering,
7143 rewrite the one currently being used as an argument to have default
7144 arguments for all parameters. */
7150 }
7151 else
7152 {
7153 tree aparms
7158 }
7161 }
7163 /* Subroutine of unify for the case when PARM is a
7164 BOUND_TEMPLATE_TEMPLATE_PARM. */
7166 static int
7169 {
7173 /* The template template parm might be variadic and the argument
7174 not, so flatten both argument lists. */
7179 {
7180 /* In keeping with P0522R0, adjust P's template arguments
7181 to apply to A's template; then flatten it again. */
7190 /* If the P0522 adjustment eliminated a pack expansion, deduce
7191 empty packs. */
7197 }
7198 else
7199 {
7200 /* Deduce arguments T, i from TT<T> or TT<i>.
7201 We check each element of PARMVEC and ARGVEC individually
7202 rather than the whole TREE_VEC since they can have
7203 different number of elements, which is allowed under N2555. */
7207 /* Check if the parameters end in a pack, making them
7208 variadic. */
7215 /* If the template argument list of P contains a pack
7216 expansion that is not the last template argument, the
7217 entire template argument list is a non-deduced
7218 context. */
7236 DEDUCE_EXACT,
7239 }
7242 }
7244 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7245 template template parameters. Both PARM_PARMS and ARG_PARMS are
7246 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7247 or PARM_DECL.
7249 Consider the example:
7250 template <class T> class A;
7251 template<template <class U> class TT> class B;
7253 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7254 the parameters to A, and OUTER_ARGS contains A. */
7256 static int
7258 tree arg_parms,
7259 tsubst_flags_t complain,
7260 tree in_decl,
7261 tree outer_args)
7262 {
7274 {
7275 /* P0522R0: A template template-parameter P is at least as specialized as
7276 a template template-argument A if, given the following rewrite to two
7277 function templates, the function template corresponding to P is at
7278 least as specialized as the function template corresponding to A
7279 according to the partial ordering rules for function templates
7280 ([temp.func.order]). Given an invented class template X with the
7281 template parameter list of A (including default arguments):
7283 * Each of the two function templates has the same template parameters,
7284 respectively, as P or A.
7286 * Each function template has a single function parameter whose type is
7287 a specialization of X with template arguments corresponding to the
7288 template parameters from the respective function template where, for
7289 each template parameter PP in the template parameter list of the
7290 function template, a corresponding template argument AA is formed. If
7291 PP declares a parameter pack, then AA is the pack expansion
7292 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7294 If the rewrite produces an invalid type, then P is not at least as
7295 specialized as A. */
7297 /* So coerce P's args to apply to A's parms, and then deduce between A's
7298 args and the converted args. If that succeeds, A is at least as
7299 specialized as P, so they match.*/
7306 {
7312 }
7313 }
7315 /* Determine whether we have a parameter pack at the end of the
7316 template template parameter's template parameter list. */
7318 {
7325 {
7339 }
7340 }
7346 /* Check all of the template parameters except the parameter pack at
7347 the end (if any). */
7349 {
7358 outer_args))
7361 }
7364 {
7365 /* Check each of the template parameters in the template
7366 argument against the template parameter pack at the end of
7367 the template template parameter. */
7374 {
7381 outer_args))
7383 }
7384 }
7387 }
7389 /* Verifies that the deduced template arguments (in TARGS) for the
7390 template template parameters (in TPARMS) represent valid bindings,
7391 by comparing the template parameter list of each template argument
7392 to the template parameter list of its corresponding template
7393 template parameter, in accordance with DR150. This
7394 routine can only be called after all template arguments have been
7395 deduced. It will return TRUE if all of the template template
7396 parameter bindings are okay, FALSE otherwise. */
7397 bool
7399 {
7403 /* We're dealing with template parms in this process. */
7409 {
7414 {
7419 {
7420 /* Look inside the argument pack. */
7423 }
7426 {
7430 /* Extract the next argument from the argument
7431 pack. */
7435 /* Look at the pattern of the pack expansion. */
7438 /* Extract the template parameters from the template
7439 argument. */
7445 /* Verify that we can coerce the template template
7446 parameters from the template argument to the template
7447 parameter. This requires an exact match. */
7449 && !coerce_template_template_parms
7451 targ_parms,
7452 tf_none,
7453 tparm,
7454 targs))
7455 {
7458 }
7459 }
7460 }
7461 }
7463 out:
7467 }
7469 /* Since type attributes aren't mangled, we need to strip them from
7470 template type arguments. */
7472 static tree
7474 {
7484 }
7486 /* And from inside dependent non-type arguments like sizeof(Type). */
7488 static tree
7490 {
7500 }
7502 // A template declaration can be substituted for a constrained
7503 // template template parameter only when the argument is more
7504 // constrained than the parameter.
7505 static bool
7507 {
7510 /* For now, allow constrained template template arguments
7511 and unconstrained template template parameters. */
7517 // If the template parameter is constrained, we need to rewrite its
7518 // constraints in terms of the ARG's template parameters. This ensures
7519 // that all of the template parameter types will have the same depth.
7520 //
7521 // Note that this is only valid when coerce_template_template_parm is
7522 // true for the innermost template parameters of PARM and ARG. In other
7523 // words, because coercion is successful, this conversion will be valid.
7525 {
7532 }
7535 }
7537 // Convert a placeholder argument into a binding to the original
7538 // parameter. The original parameter is saved as the TREE_TYPE of
7539 // ARG.
7542 {
7545 }
7547 /* Convert the indicated template ARG as necessary to match the
7548 indicated template PARM. Returns the converted ARG, or
7549 error_mark_node if the conversion was unsuccessful. Error and
7550 warning messages are issued under control of COMPLAIN. This
7551 conversion is for the Ith parameter in the parameter list. ARGS is
7552 the full set of template arguments deduced so far. */
7554 static tree
7556 tree arg,
7557 tree args,
7558 tsubst_flags_t complain,
7560 tree in_decl)
7561 {
7562 tree orig_arg;
7563 tree val;
7569 /* Trivially convert placeholders. */
7578 {
7579 /* The template argument was the name of some
7580 member function. That's usually
7581 invalid, but static members are OK. In any
7582 case, grab the underlying fields/functions
7583 and issue an error later if required. */
7586 }
7594 /* When determining whether an argument pack expansion is a template,
7595 look at the pattern. */
7599 /* Deal with an injected-class-name used as a template template arg. */
7601 {
7604 {
7614 }
7615 }
7617 is_tmpl_type =
7633 {
7635 {
7639 }
7642 "to refer to a type member of a template parameter, "
7647 typename_type,
7648 complain);
7651 }
7653 {
7655 {
7657 {
7669 else
7672 }
7673 }
7675 }
7677 {
7679 {
7686 else
7689 }
7691 }
7694 /* We already did the appropriate conversion when packing args. */
7697 {
7699 {
7701 /* The number of argument required is not known yet.
7702 Just accept it for now. */
7704 else
7705 {
7707 tree argparm;
7709 /* Strip alias templates that are equivalent to another
7710 template. */
7716 args))
7717 {
7720 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7721 TEMPLATE_DECL. */
7723 {
7728 }
7729 }
7730 else
7731 {
7733 {
7740 }
7743 }
7745 // Check that the constraints are compatible before allowing the
7746 // substitution.
7749 {
7751 {
7757 }
7759 }
7760 }
7761 }
7762 else
7764 /* We only form one instance of each template specialization.
7765 Therefore, if we use a non-canonical variant (i.e., a
7766 typedef), any future messages referring to the type will use
7767 the typedef, which is confusing if those future uses do not
7768 themselves also use the typedef. */
7771 }
7772 else
7773 {
7777 {
7781 }
7782 else
7790 /* We used to call digest_init here. However, digest_init
7791 will report errors, which we don't want when complain
7792 is zero. More importantly, digest_init will try too
7793 hard to convert things: for example, `0' should not be
7794 converted to pointer type at this point according to
7795 the standard. Accepting this is not merely an
7796 extension, since deciding whether or not these
7797 conversions can occur is part of determining which
7798 function template to call, or whether a given explicit
7799 argument specification is valid. */
7801 else
7811 {
7812 /* Reject template arguments that are references to built-in
7813 functions with no library fallbacks. */
7822 }
7825 {
7826 /* Strip typedefs from the SCOPE_REF. */
7829 complain);
7832 }
7833 }
7836 }
7838 /* Coerces the remaining template arguments in INNER_ARGS (from
7839 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7840 Returns the coerced argument pack. PARM_IDX is the position of this
7841 parameter in the template parameter list. ARGS is the original
7842 template argument list. */
7843 static tree
7846 tree args,
7847 tree inner_args,
7849 tree new_args,
7851 tree in_decl,
7852 tsubst_flags_t complain)
7853 {
7856 tree packed_args;
7857 tree argument_pack;
7864 {
7865 /* When the template parameter is a non-type template parameter pack
7866 or template template parameter pack whose type or template
7867 parameters use parameter packs, we know exactly how many arguments
7868 we are looking for. Build a vector of the instantiated decls for
7869 these template parameters in PACKED_PARMS. */
7870 /* We can't use make_pack_expansion here because it would interpret a
7871 _DECL as a use rather than a declaration. */
7885 /* If we're doing a partial instantiation of a member template,
7886 verify that all of the types used for the non-type
7887 template parameter pack are, in fact, valid for non-type
7888 template parameters. */
7891 {
7894 {
7898 }
7899 /* We don't know how many args we have yet, just
7900 use the unconverted ones for now. */
7902 }
7905 }
7906 /* Check if we have a placeholder pack, which indicates we're
7907 in the context of a introduction list. In that case we want
7908 to match this pack to the single placeholder. */
7912 {
7915 }
7916 else
7919 /* Convert the remaining arguments, which will be a part of the
7920 parameter pack "parm". */
7923 {
7929 {
7930 /* Once we've packed as many args as we have types, stop. */
7934 /* We don't know how many args we have yet, just
7935 use the unconverted ones for now. */
7937 else
7939 }
7942 {
7945 }
7946 else
7949 in_decl);
7953 }
7957 {
7962 }
7967 else
7968 {
7971 }
7978 }
7980 /* Returns the number of pack expansions in the template argument vector
7981 ARGS. */
7983 static int
7985 {
7990 {
7994 }
7996 }
7998 /* Convert all template arguments to their appropriate types, and
7999 return a vector containing the innermost resulting template
8000 arguments. If any error occurs, return error_mark_node. Error and
8001 warning messages are issued under control of COMPLAIN.
8003 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
8004 for arguments not specified in ARGS. Otherwise, if
8005 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
8006 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
8007 USE_DEFAULT_ARGS is false, then all arguments must be specified in
8008 ARGS. */
8010 static tree
8012 tree args,
8013 tree in_decl,
8014 tsubst_flags_t complain,
8017 {
8019 tree orig_inner_args;
8020 tree inner_args;
8021 tree new_args;
8022 tree new_inner_args;
8026 /* When used as a boolean value, indicates whether this is a
8027 variadic template parameter list. Since it's an int, we can also
8028 subtract it from nparms to get the number of non-variadic
8029 parameters. */
8034 /* Likewise for parameters with default arguments. */
8042 /* Determine if there are any parameter packs or default arguments. */
8044 {
8052 }
8055 /* If there are no parameters that follow a parameter pack, we need to
8056 expand any argument packs so that we can deduce a parameter pack from
8057 some non-packed args followed by an argument pack, as in variadic85.C.
8058 If there are such parameters, we need to leave argument packs intact
8059 so the arguments are assigned properly. This can happen when dealing
8060 with a nested class inside a partial specialization of a class
8061 template, as in variadic92.C, or when deducing a template parameter pack
8062 from a sub-declarator, as in variadic114.C. */
8066 /* Count any pack expansion args. */
8072 && require_all_args
8073 && !variadic_args_p
8074 && (!use_default_args
8077 {
8079 {
8081 {
8085 }
8086 else
8093 }
8096 }
8097 /* We can't pass a pack expansion to a non-pack parameter of an alias
8098 template (DR 1430). */
8102 && variadic_args_p
8104 {
8106 {
8108 {
8114 {
8117 "pack expansion argument for non-pack parameter "
8119 else
8121 "pack expansion argument for non-pack parameter "
8125 }
8126 }
8128 found:;
8129 }
8131 }
8133 /* We need to evaluate the template arguments, even though this
8134 template-id may be nested within a "sizeof". */
8143 {
8144 tree arg;
8145 tree parm;
8147 /* Get the Ith template parameter. */
8151 {
8154 }
8156 /* Calculate the next argument. */
8159 else
8164 {
8165 /* Some arguments will be placed in the
8166 template parameter pack PARM. */
8173 {
8174 /* We don't know how many args we have yet, just use the
8175 unconverted (and still packed) ones for now. */
8179 }
8183 /* Store this argument. */
8185 {
8186 lost++;
8187 /* We are done with all of the arguments. */
8189 }
8190 else
8191 {
8194 }
8197 }
8199 {
8201 {
8202 /* "If every valid specialization of a variadic template
8203 requires an empty template parameter pack, the template is
8204 ill-formed, no diagnostic required." So check that the
8205 pattern works with this parameter. */
8210 in_decl);
8212 {
8217 }
8219 /* Recover from missing typename. */
8223 /* We don't know how many args we have yet, just
8224 use the unconverted ones for now. */
8228 }
8229 }
8231 {
8232 /* There must be a default arg in this case. */
8235 /* The position of the first default template argument,
8236 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8237 Record that. */
8241 }
8242 else
8246 {
8249 }
8251 /* This only occurs if there was an error in the template
8252 parameter list itself (which we would already have
8253 reported) that we are trying to recover from, e.g., a class
8254 template with a parameter list such as
8255 template<typename..., typename>. */
8257 else
8263 lost++;
8265 }
8270 {
8272 {
8277 }
8279 }
8289 }
8291 /* Convert all template arguments to their appropriate types, and
8292 return a vector containing the innermost resulting template
8293 arguments. If any error occurs, return error_mark_node. Error and
8294 warning messages are not issued.
8296 Note that no function argument deduction is performed, and default
8297 arguments are used to fill in unspecified arguments. */
8298 tree
8300 {
8302 }
8304 /* Convert all template arguments to their appropriate type, and
8305 instantiate default arguments as needed. This returns a vector
8306 containing the innermost resulting template arguments, or
8307 error_mark_node if unsuccessful. */
8308 tree
8310 tsubst_flags_t complain)
8311 {
8313 }
8315 /* Like coerce_template_parms. If PARMS represents all template
8316 parameters levels, this function returns a vector of vectors
8317 representing all the resulting argument levels. Note that in this
8318 case, only the innermost arguments are coerced because the
8319 outermost ones are supposed to have been coerced already.
8321 Otherwise, if PARMS represents only (the innermost) vector of
8322 parameters, this function returns a vector containing just the
8323 innermost resulting arguments. */
8325 static tree
8327 tree args,
8328 tree in_decl,
8329 tsubst_flags_t complain,
8332 {
8335 tree coerced_args;
8338 {
8340 tree level;
8346 {
8347 tree l;
8351 require_all_args,
8352 use_default_args);
8353 else
8360 }
8361 }
8362 else
8365 require_all_args,
8366 use_default_args);
8368 }
8370 /* Returns 1 if template args OT and NT are equivalent. */
8372 int
8374 {
8383 /* For member templates */
8392 {
8409 }
8413 {
8416 /* Don't treat an alias template specialization with dependent
8417 arguments as equivalent to its underlying type when used as a
8418 template argument; we need them to be distinct so that we
8419 substitute into the specialization arguments at instantiation
8420 time. And aliases can't be equivalent without being ==, so
8421 we don't need to look any deeper.
8423 During partial ordering, however, we need to treat them normally so
8424 that we can order uses of the same alias with different
8425 cv-qualification (79960). */
8429 else
8431 }
8434 else
8435 {
8436 /* Try to treat a template non-type argument that has been converted
8437 to the parameter type as equivalent to one that hasn't yet. */
8450 }
8451 }
8453 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8454 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8455 NEWARG_PTR with the offending arguments if they are non-NULL. */
8457 int
8461 {
8474 {
8479 {
8485 }
8486 }
8488 }
8492 {
8494 }
8496 static void
8498 {
8508 /* We are called both from instantiate_decl, where we've already had a
8509 tinst_level pushed, and instantiate_template, where we haven't.
8510 Compensate. */
8521 else
8530 }
8533 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8534 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8535 documentation for TEMPLATE_ID_EXPR. */
8537 tree
8539 {
8540 tree type;
8548 {
8551 }
8554 {
8556 unknown_type_node,
8558 arglist);
8560 }
8567 }
8569 /* Within the scope of a template class S<T>, the name S gets bound
8570 (in build_self_reference) to a TYPE_DECL for the class, not a
8571 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8572 or one of its enclosing classes, and that type is a template,
8573 return the associated TEMPLATE_DECL. Otherwise, the original
8574 DECL is returned.
8576 Also handle the case when DECL is a TREE_LIST of ambiguous
8577 injected-class-names from different bases. */
8579 tree
8581 {
8585 /* DR 176: A lookup that finds an injected-class-name (10.2
8586 [class.member.lookup]) can result in an ambiguity in certain cases
8587 (for example, if it is found in more than one base class). If all of
8588 the injected-class-names that are found refer to specializations of
8589 the same class template, and if the name is followed by a
8590 template-argument-list, the reference refers to the class template
8591 itself and not a specialization thereof, and is not ambiguous. */
8593 {
8596 {
8602 }
8605 else
8607 }
8613 }
8615 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8616 parameters, find the desired type.
8618 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8620 IN_DECL, if non-NULL, is the template declaration we are trying to
8621 instantiate.
8623 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8624 the class we are looking up.
8626 Issue error and warning messages under control of COMPLAIN.
8628 If the template class is really a local class in a template
8629 function, then the FUNCTION_CONTEXT is the function in which it is
8630 being instantiated.
8632 ??? Note that this function is currently called *twice* for each
8633 template-id: the first time from the parser, while creating the
8634 incomplete type (finish_template_type), and the second type during the
8635 real instantiation (instantiate_template_class). This is surely something
8636 that we want to avoid. It also causes some problems with argument
8637 coercion (see convert_nontype_argument for more information on this). */
8639 static tree
8642 {
8644 tree t;
8647 spec_entry elt;
8648 hashval_t hash;
8651 {
8655 else
8656 {
8663 }
8666 }
8668 {
8671 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8672 an implicit typename for the second A. Deal with it. */
8677 {
8680 }
8681 }
8684 {
8687 }
8689 {
8693 }
8695 {
8698 }
8700 /* Issue an error message if we didn't find a template. */
8702 {
8706 }
8709 /* Make sure it's a user visible template, if it was named by
8710 the user. */
8713 {
8715 {
8719 }
8721 }
8725 /* An alias that just changes the name of a template is equivalent to the
8726 other template, so if any of the arguments are pack expansions, strip
8727 the alias to avoid problems with a pack expansion passed to a non-pack
8728 alias template parameter (DR 1430). */
8733 {
8734 tree parm;
8743 }
8744 else
8745 {
8747 tree gen_tmpl;
8748 tree type_decl;
8756 /* An error occurred while building the template TEMPL, and a
8757 diagnostic has most certainly been emitted for that
8758 already. Let's propagate that error. */
8767 {
8768 /* We've been given an incomplete set of template arguments.
8769 For example, given:
8771 template <class T> struct S1 {
8772 template <class U> struct S2 {};
8773 template <class U> struct S2<U*> {};
8774 };
8776 we will be called with an ARGLIST of `U*', but the
8777 TEMPLATE will be `template <class T> template
8778 <class U> struct S1<T>::S2'. We must fill in the missing
8779 arguments. */
8783 }
8785 /* Now we should have enough arguments. */
8788 /* From here on, we're only interested in the most general
8789 template. */
8791 /* Calculate the BOUND_ARGS. These will be the args that are
8792 actually tsubst'd into the definition to create the
8793 instantiation. */
8795 complain,
8800 /* We were unable to bind the arguments. */
8803 /* In the scope of a template class, explicit references to the
8804 template class refer to the type of the template, not any
8805 instantiation of it. For example, in:
8807 template <class T> class C { void f(C<T>); }
8809 the `C<T>' is just the same as `C'. Outside of the
8810 class, however, such a reference is an instantiation. */
8814 {
8819 }
8821 /* If we already have this specialization, return it. */
8831 /* If the the template's constraints are not satisfied,
8832 then we cannot form a valid type.
8834 Note that the check is deferred until after the hash
8835 lookup. This prevents redundant checks on previously
8836 instantiated specializations. */
8838 {
8840 {
8843 }
8845 }
8849 /* If the deduced arguments are invalid, then the binding
8850 failed. */
8854 complain))
8861 {
8866 }
8876 /* Create the type. */
8878 {
8879 /* The user referred to a specialization of an alias
8880 template represented by GEN_TMPL.
8882 [temp.alias]/2 says:
8884 When a template-id refers to the specialization of an
8885 alias template, it is equivalent to the associated
8886 type obtained by substitution of its
8887 template-arguments for the template-parameters in the
8888 type-id of the alias template. */
8891 /* Note that the call above (by indirectly calling
8892 register_specialization in tsubst_decl) registers the
8893 TYPE_DECL representing the specialization of the alias
8894 template. So next time someone substitutes ARGLIST for
8895 the template parms into the alias template (GEN_TMPL),
8896 she'll get that TYPE_DECL back. */
8900 }
8902 {
8904 {
8915 }
8916 else
8917 {
8918 /* We don't want to call start_enum for this type, since
8919 the values for the enumeration constants may involve
8920 template parameters. And, no one should be interested
8921 in the enumeration constants for such a type. */
8924 }
8928 }
8930 {
8936 /* A local class. Make sure the decl gets registered properly. */
8941 /* This instantiation is another name for the primary
8942 template type. Set the TYPE_CANONICAL field
8943 appropriately. */
8946 /* Some of the template arguments require structural
8947 equality testing, so this template class requires
8948 structural equality testing. */
8950 }
8951 else
8954 /* If we called start_enum or pushtag above, this information
8955 will already be set up. */
8957 {
8964 }
8965 else
8969 {
8975 {
8978 }
8979 }
8983 {
8987 {
8988 tree attributes
8996 }
8997 }
8999 /* Let's consider the explicit specialization of a member
9000 of a class template specialization that is implicitly instantiated,
9001 e.g.:
9002 template<class T>
9003 struct S
9004 {
9005 template<class U> struct M {}; //#0
9006 };
9008 template<>
9009 template<>
9010 struct S<int>::M<char> //#1
9011 {
9012 int i;
9013 };
9014 [temp.expl.spec]/4 says this is valid.
9016 In this case, when we write:
9017 S<int>::M<char> m;
9019 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
9020 the one of #0.
9022 When we encounter #1, we want to store the partial instantiation
9023 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
9025 For all cases other than this "explicit specialization of member of a
9026 class template", we just want to store the most general template into
9027 the CLASSTYPE_TI_TEMPLATE of M.
9029 This case of "explicit specialization of member of a class template"
9030 only happens when:
9031 1/ the enclosing class is an instantiation of, and therefore not
9032 the same as, the context of the most general template, and
9033 2/ we aren't looking at the partial instantiation itself, i.e.
9034 the innermost arguments are not the same as the innermost parms of
9035 the most general template.
9037 So it's only when 1/ and 2/ happens that we want to use the partial
9038 instantiation of the member template in lieu of its most general
9039 template. */
9043 /* the enclosing class must be an instantiation... */
9046 {
9050 tree partial_inst_args =
9057 use_partial_inst_tmpl =
9058 /*...and we must not be looking at the partial instantiation
9059 itself. */
9061 partial_inst_args);
9062 }
9065 /* This case is easy; there are no member templates involved. */
9067 else
9068 {
9069 /* This is a full instantiation of a member template. Find
9070 the partial instantiation of which this is an instance. */
9072 /* Temporarily reduce by one the number of levels in the ARGLIST
9073 so as to avoid comparing the last set of arguments. */
9077 /* FOUND is either a proper class type, or an alias
9078 template specialization. In the later case, it's a
9079 TYPE_DECL, resulting from the substituting of arguments
9080 for parameters in the TYPE_DECL of the alias template
9081 done earlier. So be careful while getting the template
9082 of FOUND. */
9084 ? found
9088 }
9090 // Build template info for the new specialization.
9099 /* Note this use of the partial instantiation so we can check it
9100 later in maybe_process_partial_specialization. */
9107 /* Now that the type has been registered on the instantiations
9108 list, we set up the enumerators. Because the enumeration
9109 constants may involve the enumeration type itself, we make
9110 sure to register the type first, and then create the
9111 constants. That way, doing tsubst_expr for the enumeration
9112 constants won't result in recursive calls here; we'll find
9113 the instantiation and exit above. */
9117 /* If the type makes use of template parameters, the
9118 code that generates debugging information will crash. */
9121 /* Possibly limit visibility based on template args. */
9128 }
9129 }
9131 /* Wrapper for lookup_template_class_1. */
9133 tree
9136 {
9137 tree ret;
9143 }
9145 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9147 tree
9149 {
9150 /* The type of the expression is NULL_TREE since the template-id could refer
9151 to an explicit or partial specialization. */
9154 /* Except that concepts are always bool. */
9157 }
9159 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9161 tree
9163 {
9167 /* We never want to return a VAR_DECL for a variable concept, since they
9168 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9183 {
9185 {
9188 }
9190 }
9192 /* If a template-id refers to a specialization of a variable
9193 concept, then the expression is true if and only if the
9194 concept's constraints are satisfied by the given template
9195 arguments.
9197 NOTE: This is an extension of Concepts Lite TS that
9198 allows constraints to be used in expressions. */
9200 {
9203 }
9206 }
9208 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9209 TARGS template args, and instantiate it if it's not dependent. */
9211 tree
9213 tsubst_flags_t complain)
9214 {
9217 {
9220 }
9223 }
9225 \f
9226 struct pair_fn_data
9227 {
9228 tree_fn_t fn;
9229 tree_fn_t any_fn;
9231 /* True when we should also visit template parameters that occur in
9232 non-deduced contexts. */
9235 };
9237 /* Called from for_each_template_parm via walk_tree. */
9239 static tree
9241 {
9248 #define WALK_SUBTREE(NODE) \
9249 do \
9250 { \
9251 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9252 pfd->include_nondeduced_p, \
9253 pfd->any_fn); \
9254 if (result) goto out; \
9255 } \
9256 while (0)
9266 {
9270 /* Fall through. */
9276 else
9286 /* Since we're not going to walk subtrees, we have to do this
9287 explicitly here. */
9289 /* Fall through. */
9292 /* Check the return type. */
9295 /* Check the parameter types. Since default arguments are not
9296 instantiated until they are needed, the TYPE_ARG_TYPES may
9297 contain expressions that involve template parameters. But,
9298 no-one should be looking at them yet. And, once they're
9299 instantiated, they don't contain template parameters, so
9300 there's no point in looking at them then, either. */
9301 {
9302 tree parm;
9307 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9308 want walk_tree walking into them itself. */
9310 }
9313 {
9317 }
9334 /* Fall through. */
9346 /* Record template parameters such as `T' inside `TT<T>'. */
9348 /* Fall through. */
9360 /* A template template parameter is encountered. */
9364 /* Already substituted template template parameter */
9369 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9370 partial instantiation. */
9382 /* If there's no type, then this thing must be some expression
9383 involving template parameters. */
9405 }
9407 #undef WALK_SUBTREE
9409 /* We didn't find any template parameters we liked. */
9410 out:
9412 }
9414 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9415 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9416 call FN with the parameter and the DATA.
9417 If FN returns nonzero, the iteration is terminated, and
9418 for_each_template_parm returns 1. Otherwise, the iteration
9419 continues. If FN never returns a nonzero value, the value
9420 returned by for_each_template_parm is 0. If FN is NULL, it is
9421 considered to be the function which always returns 1.
9423 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9424 parameters that occur in non-deduced contexts. When false, only
9425 visits those template parameters that can be deduced. */
9427 static tree
9431 tree_fn_t any_fn)
9432 {
9434 tree result;
9436 /* Set up. */
9442 /* Walk the tree. (Conceptually, we would like to walk without
9443 duplicates, but for_each_template_parm_r recursively calls
9444 for_each_template_parm, so we would need to reorganize a fair
9445 bit to use walk_tree_without_duplicates, so we keep our own
9446 visited list.) */
9449 else
9452 for_each_template_parm_r,
9456 /* Clean up. */
9458 {
9461 }
9464 }
9466 /* Returns true if T depends on any template parameter. */
9468 int
9470 {
9500 else
9501 {
9504 }
9509 }
9511 /* Returns true iff current_function_decl is an incompletely instantiated
9512 template. Useful instead of processing_template_decl because the latter
9513 is set to 0 during instantiate_non_dependent_expr. */
9515 bool
9517 {
9526 }
9528 /* Returns true if T depends on any template parameter with level LEVEL. */
9530 bool
9532 {
9535 }
9537 /* Returns true if the signature of DECL depends on any template parameter from
9538 its enclosing class. */
9540 bool
9542 {
9552 template_parm_outer_level,
9562 }
9564 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9565 ill-formed translation unit, i.e. a variable or function that isn't
9566 usable in a constant expression. */
9570 {
9575 }
9577 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9578 neglectable and instantiated from within an erroneous instantiation. */
9580 static bool
9582 {
9593 }
9601 /* We're starting to instantiate D; record the template instantiation context
9602 for diagnostics and to restore it later. */
9604 bool
9606 {
9608 }
9610 /* We're starting to instantiate D; record the template instantiation context
9611 at LOC for diagnostics and to restore it later. */
9613 bool
9615 {
9619 {
9620 /* Tell error.c not to try to instantiate any templates. */
9623 "template instantiation depth exceeds maximum of %d"
9625 max_tinst_depth);
9627 }
9629 /* If the current instantiation caused problems, don't let it instantiate
9630 anything else. Do allow deduction substitution and decls usable in
9631 constant expressions. */
9635 /* When not -quiet, dump template instantiations other than functions, since
9636 announce_function will take care of those. */
9655 }
9657 /* We're done instantiating this template; return to the instantiation
9658 context. */
9660 void
9662 {
9663 /* Restore the filename and line number stashed away when we started
9664 this instantiation. */
9668 }
9670 /* We're instantiating a deferred template; restore the template
9671 instantiation context in which the instantiation was requested, which
9672 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9674 static tree
9676 {
9688 }
9690 /* Returns the TINST_LEVEL which gives the original instantiation
9691 context. */
9695 {
9701 }
9703 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9704 vector of template arguments, as for tsubst.
9706 Returns an appropriate tsubst'd friend declaration. */
9708 static tree
9710 {
9711 tree new_friend;
9716 /* This was a friend declared with an explicit template
9717 argument list, e.g.:
9719 friend void f<>(T);
9721 to indicate that f was a template instantiation, not a new
9722 function declaration. Now, we have to figure out what
9723 instantiation of what template. */
9724 {
9726 tree new_args;
9727 tree tmpl;
9730 /* Friend functions are looked up in the containing namespace scope.
9731 We must enter that scope, to avoid finding member functions of the
9732 current class with same name. */
9747 tsk_none);
9749 }
9753 /* The NEW_FRIEND will look like an instantiation, to the
9754 compiler, but is not an instantiation from the point of view of
9755 the language. For example, we might have had:
9757 template <class T> struct S {
9758 template <class U> friend void f(T, U);
9759 };
9761 Then, in S<int>, template <class U> void f(int, U) is not an
9762 instantiation of anything. */
9768 {
9772 }
9774 /* The mangled name for the NEW_FRIEND is incorrect. The function
9775 is not a template instantiation and should not be mangled like
9776 one. Therefore, we forget the mangling here; we'll recompute it
9777 later if we need it. */
9779 {
9782 }
9785 {
9786 tree old_decl;
9787 tree new_friend_template_info;
9788 tree new_friend_result_template_info;
9789 tree ns;
9792 /* We must save some information from NEW_FRIEND before calling
9793 duplicate decls since that function will free NEW_FRIEND if
9794 possible. */
9796 new_friend_is_defn =
9801 {
9802 /* This declaration is a `primary' template. */
9805 new_friend_result_template_info
9807 }
9808 else
9811 /* Inside pushdecl_namespace_level, we will push into the
9812 current namespace. However, the friend function should go
9813 into the namespace of the template. */
9823 {
9824 /* This new friend declaration matched an existing
9825 declaration. For example, given:
9827 template <class T> void f(T);
9828 template <class U> class C {
9829 template <class T> friend void f(T) {}
9830 };
9832 the friend declaration actually provides the definition
9833 of `f', once C has been instantiated for some type. So,
9834 old_decl will be the out-of-class template declaration,
9835 while new_friend is the in-class definition.
9837 But, if `f' was called before this point, the
9838 instantiation of `f' will have DECL_TI_ARGS corresponding
9839 to `T' but not to `U', references to which might appear
9840 in the definition of `f'. Previously, the most general
9841 template for an instantiation of `f' was the out-of-class
9842 version; now it is the in-class version. Therefore, we
9843 run through all specialization of `f', adding to their
9844 DECL_TI_ARGS appropriately. In particular, they need a
9845 new set of outer arguments, corresponding to the
9846 arguments for this class instantiation.
9848 The same situation can arise with something like this:
9850 friend void f(int);
9851 template <class T> class C {
9852 friend void f(T) {}
9853 };
9855 when `C<int>' is instantiated. Now, `f(int)' is defined
9856 in the class. */
9859 /* On the other hand, if the in-class declaration does
9860 *not* provide a definition, then we don't want to alter
9861 existing definitions. We can just leave everything
9862 alone. */
9863 ;
9864 else
9865 {
9869 /* Overwrite whatever template info was there before, if
9870 any, with the new template information pertaining to
9871 the declaration. */
9875 {
9876 /* We should have called reregister_specialization in
9877 duplicate_decls. */
9882 /* Instantiate it if the global has already been used. */
9886 }
9887 else
9888 {
9889 tree t;
9891 /* Indicate that the old function template is a partial
9892 instantiation. */
9900 /* Reassign any specializations already in the hash table
9901 to the new more general template, and add the
9902 additional template args. */
9906 {
9908 spec_entry elt;
9920 register_specialization
9923 }
9925 }
9926 }
9928 /* The information from NEW_FRIEND has been merged into OLD_DECL
9929 by duplicate_decls. */
9931 }
9932 }
9933 else
9934 {
9938 /* In the code
9939 template <class T> class C {
9940 template <class U> friend void C1<U>::f (); // case 1
9941 friend void C2<T>::f (); // case 2
9942 };
9943 we only need to make sure CONTEXT is a complete type for
9944 case 2. To distinguish between the two cases, we note that
9945 CONTEXT of case 1 remains dependent type after tsubst while
9946 this isn't true for case 2. */
9956 {
9958 /* do_friend adds the TEMPLATE_DECL for any member friend
9959 template even if it isn't a member template, i.e.
9960 template <class T> friend A<T>::f();
9961 Look through it in that case. */
9965 /* Check to see that the declaration is really present, and,
9966 possibly obtain an improved declaration. */
9971 }
9972 }
9975 }
9977 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9978 template arguments, as for tsubst.
9980 Returns an appropriate tsubst'd friend type or error_mark_node on
9981 failure. */
9983 static tree
9985 {
9986 tree friend_type;
9987 tree tmpl;
9988 tree context;
9991 {
9994 }
9999 {
10002 else
10004 }
10006 /* Look for a class template declaration. We look for hidden names
10007 because two friend declarations of the same template are the
10008 same. For example, in:
10010 struct A {
10011 template <typename> friend class F;
10012 };
10013 template <typename> struct B {
10014 template <typename> friend class F;
10015 };
10017 both F templates are the same. */
10021 /* But, if we don't find one, it might be because we're in a
10022 situation like this:
10024 template <class T>
10025 struct S {
10026 template <class U>
10027 friend struct S;
10028 };
10030 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
10031 for `S<int>', not the TEMPLATE_DECL. */
10033 {
10036 }
10039 {
10040 /* The friend template has already been declared. Just
10041 check to see that the declarations match, and install any new
10042 default parameters. We must tsubst the default parameters,
10043 of course. We only need the innermost template parameters
10044 because that is all that redeclare_class_template will look
10045 at. */
10048 {
10049 tree parms;
10050 location_t saved_input_location;
10060 }
10063 }
10064 else
10065 {
10066 /* The friend template has not already been declared. In this
10067 case, the instantiation of the template class will cause the
10068 injection of this template into the global scope. */
10073 /* The new TMPL is not an instantiation of anything, so we
10074 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10075 the new type because that is supposed to be the corresponding
10076 template decl, i.e., TMPL. */
10083 /* Inject this template into the global scope. */
10085 }
10088 {
10091 else
10093 }
10096 }
10098 /* Returns zero if TYPE cannot be completed later due to circularity.
10099 Otherwise returns one. */
10101 static int
10103 {
10113 else
10115 }
10120 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10121 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10123 static tree
10126 {
10135 {
10142 clauses
10146 else
10148 }
10149 /* If the first attribute argument is an identifier, don't
10150 pass it through tsubst. Attributes like mode, format,
10151 cleanup and several target specific attributes expect it
10152 unmodified. */
10154 {
10155 tree chain
10160 }
10162 {
10163 /* An attribute pack expansion. */
10172 {
10176 }
10178 }
10179 else
10186 }
10188 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10189 unchanged or a new TREE_LIST chain. */
10191 static tree
10194 {
10199 {
10203 }
10207 {
10210 {
10213 {
10215 do
10220 }
10221 }
10223 }
10226 }
10228 /* Apply any attributes which had to be deferred until instantiation
10229 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10230 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10232 static void
10235 {
10237 tree t;
10244 {
10248 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10249 to our attributes parameter. */
10251 }
10252 else
10253 {
10255 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10256 lookup_template_class_1, and should be preserved. */
10260 }
10264 {
10268 }
10272 {
10277 {
10280 {
10284 do
10287 }
10288 else
10290 }
10293 }
10294 }
10296 /* Perform (or defer) access check for typedefs that were referenced
10297 from within the template TMPL code.
10298 This is a subroutine of instantiate_decl and instantiate_class_template.
10299 TMPL is the template to consider and TARGS is the list of arguments of
10300 that template. */
10302 static void
10304 {
10305 location_t saved_location;
10316 {
10328 /* Make access check error messages point to the location
10329 of the use of the typedef. */
10333 tf_warning_or_error);
10334 }
10336 }
10338 static tree
10340 {
10342 tree typedecl;
10343 tree pbinfo;
10344 tree base_list;
10346 tree fn_context;
10355 /* Figure out which template is being instantiated. */
10359 /* Determine what specialization of the original template to
10360 instantiate. */
10363 {
10366 }
10368 {
10369 /* This TYPE is actually an instantiation of a partial
10370 specialization. We replace the innermost set of ARGS with
10371 the arguments appropriate for substitution. For example,
10372 given:
10374 template <class T> struct S {};
10375 template <class T> struct S<T*> {};
10377 and supposing that we are instantiating S<int*>, ARGS will
10378 presently be {int*} -- but we need {int}. */
10381 }
10382 else
10383 {
10386 }
10388 /* If the template we're instantiating is incomplete, then clearly
10389 there's nothing we can do. */
10393 /* If we've recursively instantiated too many templates, stop. */
10397 /* Now we're really doing the instantiation. Mark the type as in
10398 the process of being defined. */
10401 /* We may be in the middle of deferred access check. Disable
10402 it now. */
10409 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10414 else
10415 {
10418 }
10419 /* Use #pragma pack from the template context. */
10425 /* Set the input location to the most specialized template definition.
10426 This is needed if tsubsting causes an error. */
10438 {
10441 /* Adjust visibility for template arguments. */
10443 }
10449 /* We should never instantiate a nested class before its enclosing
10450 class; we need to look up the nested class by name before we can
10451 instantiate it, and that lookup should instantiate the enclosing
10452 class. */
10458 {
10459 tree pbase_binfo;
10460 tree pushed_scope;
10463 /* We must enter the scope containing the type, as that is where
10464 the accessibility of types named in dependent bases are
10465 looked up from. */
10468 /* Substitute into each of the bases to determine the actual
10469 basetypes. */
10471 {
10472 tree base;
10478 {
10479 expanded_bases =
10486 }
10489 {
10491 /* Extract the already-expanded base class. */
10493 else
10494 /* Substitute to figure out the base class. */
10496 NULL_TREE);
10504 }
10505 }
10507 /* The list is now in reverse order; correct that. */
10512 }
10513 /* Now call xref_basetypes to set up all the base-class
10514 information. */
10522 /* Now that our base classes are set up, enter the scope of the
10523 class, so that name lookups into base classes, etc. will work
10524 correctly. This is precisely analogous to what we do in
10525 begin_class_definition when defining an ordinary non-template
10526 class, except we also need to push the enclosing classes. */
10529 /* Now members are processed in the order of declaration. */
10532 {
10536 {
10538 {
10539 /* Build new CLASSTYPE_NESTED_UTDS. */
10541 tree newtag;
10547 /* If the member is a class template, then -- even after
10548 substitution -- there may be dependent types in the
10549 template argument list for the class. We increment
10550 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10551 that function will assume that no types are dependent
10552 when outside of a template. */
10562 {
10566 /* Unfortunately, lookup_template_class sets
10567 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10568 instantiation (i.e., for the type of a member
10569 template class nested within a template class.)
10570 This behavior is required for
10571 maybe_process_partial_specialization to work
10572 correctly, but is not accurate in this case;
10573 the TAG is not an instantiation of anything.
10574 (The corresponding TEMPLATE_DECL is an
10575 instantiation, but the TYPE is not.) */
10578 /* Now, we call pushtag to put this NEWTAG into the scope of
10579 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10580 pushtag calling push_template_decl. We don't have to do
10581 this for enums because it will already have been done in
10582 tsubst_enum. */
10586 }
10587 }
10589 {
10590 tree r;
10599 /* Instantiate members marked with attribute used. */
10605 }
10608 /* A closure type for a lambda in a default argument for a
10609 member template. Ignore it; it will be instantiated with
10611 else
10612 {
10613 /* Build new TYPE_FIELDS. */
10615 {
10616 tree condition;
10619 condition =
10629 }
10631 {
10632 tree r;
10636 /* The file and line for this declaration, to
10637 assist in error message reporting. Since we
10638 called push_tinst_level above, we don't need to
10639 restore these. */
10649 {
10650 /* A capture pack became multiple fields. */
10653 }
10656 {
10660 {
10661 /* In [temp.inst]:
10663 [t]he initialization (and any associated
10664 side-effects) of a static data member does
10665 not occur unless the static data member is
10666 itself used in a way that requires the
10667 definition of the static data member to
10668 exist.
10670 Therefore, we do not substitute into the
10671 initialized for the static data member here. */
10672 finish_static_data_member_decl
10678 /* Instantiate members marked with attribute used. */
10681 }
10683 {
10684 /* Determine whether R has a valid type and can be
10685 completed later. If R is invalid, then its type
10686 is replaced by error_mark_node. */
10692 {
10693 /* If R's type couldn't be completed and
10694 it isn't a flexible array member (whose
10695 type is incomplete by definition) give
10696 an error. */
10699 }
10700 }
10702 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10703 such a thing will already have been added to the field
10704 list by tsubst_enum in finish_member_declaration in the
10705 CLASSTYPE_NESTED_UTDS case above. */
10709 {
10712 }
10713 }
10714 }
10715 }
10716 }
10717 else
10718 {
10721 {
10722 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10728 {
10729 /* template <class T> friend class C; */
10732 }
10734 {
10735 /* template <class T> friend class C::D; */
10741 }
10744 {
10745 /* This could be either
10747 friend class T::C;
10749 when dependent_type_p is false or
10751 template <class U> friend class T::C;
10753 otherwise. */
10754 /* Bump processing_template_decl in case this is something like
10755 template <class T> friend struct A<T>::B. */
10762 }
10766 {
10767 /* friend class C;
10769 where C hasn't been declared yet. Let's lookup name
10770 from namespace scope directly, bypassing any name that
10771 come from dependent base class. */
10774 /* The call to xref_tag_from_type does injection for friend
10775 classes. */
10777 friend_type =
10781 }
10783 /* friend class C<T>; */
10786 /* Otherwise it's
10788 friend class C;
10790 where C is already declared or
10792 friend class C<int>;
10794 We don't have to do anything in these cases. */
10797 /* Trick make_friend_class into realizing that the friend
10798 we're adding is a template, not an ordinary class. It's
10799 important that we use make_friend_class since it will
10800 perform some error-checking and output cross-reference
10801 information. */
10809 }
10810 else
10811 {
10812 /* Build new DECL_FRIENDLIST. */
10813 tree r;
10815 /* The file and line for this declaration, to
10816 assist in error message reporting. Since we
10817 called push_tinst_level above, we don't need to
10818 restore these. */
10822 {
10825 }
10830 {
10833 }
10834 }
10835 }
10836 }
10839 {
10840 /* Restore these before substituting into the lambda capture
10841 initializers. */
10844 }
10847 {
10850 {
10856 {
10857 /* Set function_depth to avoid garbage collection. */
10861 }
10863 /* We need to instantiate the capture list from the template
10864 after we've instantiated the closure members, but before we
10865 consider adding the conversion op. Also keep any captures
10866 that may have been added during instantiation of the op(). */
10868 tree tmpl_cap
10877 }
10878 else
10880 }
10882 /* Set the file and line number information to whatever is given for
10883 the class itself. This puts error messages involving generated
10884 implicit functions at a predictable point, and the same point
10885 that would be used for non-template classes. */
10892 /* We don't instantiate default arguments for member functions. 14.7.1:
10894 The implicit instantiation of a class template specialization causes
10895 the implicit instantiation of the declarations, but not of the
10896 definitions or default arguments, of the class member functions,
10897 member classes, static data members and member templates.... */
10899 /* Some typedefs referenced from within the template code need to be access
10900 checked at template instantiation time, i.e now. These types were
10901 added to the template at parsing time. Let's get those and perform
10902 the access checks then. */
10912 /* The vtable for a template class can be emitted in any translation
10913 unit in which the class is instantiated. When there is no key
10914 method, however, finish_struct_1 will already have added TYPE to
10915 the keyed_classes. */
10920 }
10922 /* Wrapper for instantiate_class_template_1. */
10924 tree
10926 {
10927 tree ret;
10932 }
10934 static tree
10936 {
10937 tree r;
10943 else
10944 {
10951 }
10953 }
10955 /* Given a function parameter pack TMPL_PARM and some function parameters
10956 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10957 and set *SPEC_P to point at the next point in the list. */
10959 tree
10961 {
10962 /* Collect all of the extra "packed" parameters into an
10963 argument pack. */
10964 tree parmvec;
10974 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10980 /* Build the argument packs. */
10985 }
10987 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10988 NONTYPE_ARGUMENT_PACK. */
10990 static tree
10992 {
10994 }
10996 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10997 pack expansion with no extra args, 2 if it has extra args, or 0
10998 if it is not a pack expansion. */
11000 static int
11002 {
11008 /* A decl pack is itself an expansion. */
11015 }
11018 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
11020 static tree
11022 {
11029 }
11031 /* This is a subroutine of tsubst_pack_expansion.
11033 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
11034 mechanism to store the (non complete list of) arguments of the
11035 substitution and return a non substituted pack expansion, in order
11036 to wait for when we have enough arguments to really perform the
11037 substitution. */
11039 static bool
11043 {
11044 /* If one pack has an expansion and another pack has a normal
11045 argument or if one pack has an empty argument and an another
11046 one hasn't then tsubst_pack_expansion cannot perform the
11047 substitution and need to fall back on the
11048 PACK_EXPANSION_EXTRA mechanism. */
11056 {
11059 parm_pack;
11061 {
11066 /* We can't substitute a pack expansion with extra args into
11067 our pattern. */
11071 else
11073 }
11077 }
11079 }
11081 /* [temp.variadic]/6 says that:
11083 The instantiation of a pack expansion [...]
11084 produces a list E1,E2, ..., En, where N is the number of elements
11085 in the pack expansion parameters.
11087 This subroutine of tsubst_pack_expansion produces one of these Ei.
11089 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11090 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11091 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11092 INDEX is the index 'i' of the element Ei to produce. ARGS,
11093 COMPLAIN, and IN_DECL are the same parameters as for the
11094 tsubst_pack_expansion function.
11096 The function returns the resulting Ei upon successful completion,
11097 or error_mark_node.
11099 Note that this function possibly modifies the ARGS parameter, so
11100 it's the responsibility of the caller to restore it. */
11102 static tree
11104 tree parm_packs,
11106 tree args /* This parm gets
11108 tsubst_flags_t complain,
11109 tree in_decl)
11110 {
11111 tree t;
11114 /* For each parameter pack, change the substitution of the parameter
11115 pack to the ith argument in its argument pack, then expand the
11116 pattern. */
11118 {
11123 ith_elem_is_expansion |=
11126 /* Select the Ith argument from the pack. */
11129 {
11131 {
11136 }
11137 else
11139 }
11140 else
11141 {
11146 {
11148 /* Update the corresponding argument. */
11150 }
11151 else
11152 /* Re-use the ARGUMENT_PACK_SELECT. */
11154 }
11156 }
11158 /* Substitute into the PATTERN with the (possibly altered)
11159 arguments. */
11161 /* Expanding a fixed parameter pack from
11162 coerce_template_parameter_pack. */
11167 {
11170 else
11173 }
11177 else
11180 /* If the Ith argument pack element is a pack expansion, then
11181 the Ith element resulting from the substituting is going to
11182 be a pack expansion as well. */
11187 }
11189 /* When the unexpanded parameter pack in a fold expression expands to an empty
11190 sequence, the value of the expression is as follows; the program is
11191 ill-formed if the operator is not listed in this table.
11193 && true
11194 || false
11195 , void() */
11197 tree
11199 {
11203 {
11212 }
11218 }
11220 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11221 form an expression that combines the two terms using the
11222 operator of T. */
11224 static tree
11226 {
11230 // Handle compound assignment operators.
11235 {
11245 complain);
11246 }
11247 }
11249 /* Substitute ARGS into the pack of a fold expression T. */
11253 {
11255 }
11257 /* Substitute ARGS into the pack of a fold expression T. */
11261 {
11263 }
11265 /* Expand a PACK of arguments into a grouped as left fold.
11266 Given a pack containing elements A0, A1, ..., An and an
11267 operator @, this builds the expression:
11269 ((A0 @ A1) @ A2) ... @ An
11271 Note that PACK must not be empty.
11273 The operator is defined by the original fold expression T. */
11275 static tree
11277 {
11280 {
11283 }
11285 }
11287 /* Substitute into a unary left fold expression. */
11289 static tree
11291 tree in_decl)
11292 {
11297 {
11301 }
11304 else
11306 }
11308 /* Substitute into a binary left fold expression.
11310 Do ths by building a single (non-empty) vector of argumnts and
11311 building the expression from those elements. */
11313 static tree
11315 tree in_decl)
11316 {
11325 {
11330 }
11338 }
11340 /* Expand a PACK of arguments into a grouped as right fold.
11341 Given a pack containing elementns A0, A1, ..., and an
11342 operator @, this builds the expression:
11344 A0@ ... (An-2 @ (An-1 @ An))
11346 Note that PACK must not be empty.
11348 The operator is defined by the original fold expression T. */
11350 tree
11352 {
11353 // Build the expression.
11357 {
11360 }
11362 }
11364 /* Substitute into a unary right fold expression. */
11366 static tree
11368 tree in_decl)
11369 {
11374 {
11378 }
11381 else
11383 }
11385 /* Substitute into a binary right fold expression.
11387 Do ths by building a single (non-empty) vector of arguments and
11388 building the expression from those elements. */
11390 static tree
11392 tree in_decl)
11393 {
11402 {
11407 }
11416 }
11419 /* Substitute ARGS into T, which is an pack expansion
11420 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11421 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11422 (if only a partial substitution could be performed) or
11423 ERROR_MARK_NODE if there was an error. */
11424 tree
11426 tree in_decl)
11427 {
11428 tree pattern;
11432 tree result;
11440 /* Add in any args remembered from an earlier partial instantiation. */
11445 /* Determine the argument packs that will instantiate the parameter
11446 packs used in the expansion expression. While we're at it,
11447 compute the number of arguments to be expanded and make sure it
11448 is consistent. */
11451 {
11458 {
11463 else
11466 }
11468 {
11469 /* ??? Support use in other patterns. */
11473 }
11475 {
11476 /* We know we have correct local_specializations if this
11477 expansion is at function scope, or if we're dealing with a
11478 local parameter in a requires expression; for the latter,
11479 tsubst_requires_expr set it up appropriately. */
11482 else
11483 /* We can't rely on local_specializations for a parameter
11484 name used later in a function declaration (such as in a
11485 late-specified return type). Even if it exists, it might
11486 have the wrong value for a recursive call. */
11490 {
11491 /* This parameter pack was used in an unevaluated context. Just
11492 make a dummy decl, since it's only used for its type. */
11495 /* Partial instantiation of the parm_pack, we can't build
11496 up an argument pack yet. */
11498 else
11500 }
11501 }
11504 else
11505 {
11511 }
11518 /* This can only happen if we forget to expand an argument
11519 pack somewhere else. Just return an error, silently. */
11520 {
11524 }
11527 {
11531 /* Don't bother trying to do a partial substitution with
11532 incomplete packs; we'll try again after deduction. */
11539 {
11544 pattern);
11545 else
11547 pattern);
11549 }
11551 /* Keep track of the parameter packs and their corresponding
11552 argument packs. */
11555 }
11556 else
11557 {
11558 /* We can't substitute for this parameter pack. We use a flag as
11559 well as the missing_level counter because function parameter
11560 packs don't have a level. */
11563 }
11564 }
11566 /* If the expansion is just T..., return the matching argument pack, unless
11567 we need to call convert_from_reference on all the elements. This is an
11568 important optimization; see c++/68422. */
11571 {
11573 /* Types need no adjustment, nor does sizeof..., and if we still have
11574 some pack expansion args we won't do anything yet. */
11579 /* Also optimize expression pack expansions if we can tell that the
11580 elements won't have reference type. */
11586 /* Otherwise use the normal path so we get convert_from_reference. */
11587 }
11589 /* We cannot expand this expansion expression, because we don't have
11590 all of the argument packs we need. */
11592 {
11593 /* We got some full packs, but we can't substitute them in until we
11594 have values for all the packs. So remember these until then. */
11599 }
11601 {
11602 /* There were no real arguments, we're just replacing a parameter
11603 pack with another version of itself. Substitute into the
11604 pattern and return a PACK_EXPANSION_*. The caller will need to
11605 deal with that. */
11609 else
11613 }
11618 {
11619 /* We're in a late-specified return type, so create our own local
11620 specializations map; the current map is either NULL or (in the
11621 case of recursive unification) might have bindings that we don't
11622 want to use or alter. */
11625 }
11627 /* For each argument in each argument pack, substitute into the
11628 pattern. */
11632 {
11634 i,
11636 in_decl);
11639 {
11642 }
11643 }
11645 /* Update ARGS to restore the substitution from parameter packs to
11646 their argument packs. */
11648 {
11654 else
11655 {
11663 /* Update the corresponding argument. */
11667 else
11669 }
11670 }
11673 {
11676 }
11678 /* If the dependent pack arguments were such that we end up with only a
11679 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11685 }
11687 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11688 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11689 parameter packs; all parms generated from a function parameter pack will
11690 have the same DECL_PARM_INDEX. */
11692 tree
11694 {
11696 tree patparm;
11699 {
11705 }
11706 else
11707 {
11712 }
11715 }
11717 /* Make an argument pack out of the TREE_VEC VEC. */
11719 static tree
11721 {
11722 tree pack;
11726 else
11727 {
11730 }
11733 }
11735 /* Return an exact copy of template args T that can be modified
11736 independently. */
11738 static tree
11740 {
11748 {
11753 }
11759 }
11761 /* Substitute ARGS into the vector or list of template arguments T. */
11763 static tree
11765 {
11777 {
11779 tree new_arg;
11784 {
11785 /* Substitute into an expansion expression. */
11789 /* Add to the expanded length adjustment the number of
11790 expanded arguments. We subtract one from this
11791 measurement, because the argument pack expression
11792 itself is already counted as 1 in
11793 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11794 the argument pack is empty. */
11796 }
11798 {
11799 /* Substitute into each of the arguments. */
11808 else
11813 }
11814 else
11823 }
11828 /* Make space for the expanded arguments coming from template
11829 argument packs. */
11831 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11832 arguments for a member template.
11833 In that case each TREE_VEC in ORIG_T represents a level of template
11834 arguments, and ORIG_T won't carry any non defaulted argument count.
11835 It will rather be the nested TREE_VECs that will carry one.
11836 In other words, ORIG_T carries a non defaulted argument count only
11837 if it doesn't contain any nested TREE_VEC. */
11839 {
11843 }
11845 {
11849 {
11852 /* Now expand the template argument pack "in place". */
11855 }
11856 else
11857 {
11859 out++;
11860 }
11861 }
11864 }
11866 /* Substitute ARGS into one level PARMS of template parameters. */
11868 static tree
11870 {
11877 {
11885 }
11888 }
11890 /* Return the result of substituting ARGS into the template parameters
11891 given by PARMS. If there are m levels of ARGS and m + n levels of
11892 PARMS, then the result will contain n levels of PARMS. For
11893 example, if PARMS is `template <class T> template <class U>
11894 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11895 result will be `template <int*, double, class V>'. */
11897 static tree
11899 {
11903 /* When substituting into a template, we must set
11904 PROCESSING_TEMPLATE_DECL as the template parameters may be
11905 dependent if they are based on one-another, and the dependency
11906 predicates are short-circuit outside of templates. */
11913 {
11920 }
11925 }
11927 /* Return the result of substituting ARGS into one template parameter
11928 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11929 parameter and which TREE_PURPOSE is the default argument of the
11930 template parameter. */
11932 static tree
11934 {
11955 }
11957 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11958 type T. If T is not an aggregate or enumeration type, it is
11959 handled as if by tsubst. IN_DECL is as for tsubst. If
11960 ENTERING_SCOPE is nonzero, T is the context for a template which
11961 we are presently tsubst'ing. Return the substituted value. */
11963 static tree
11965 tree args,
11966 tsubst_flags_t complain,
11967 tree in_decl,
11969 {
11974 {
11979 /* Fall through. */
11983 {
11984 tree argvec;
11985 tree context;
11986 tree r;
11990 /* In "sizeof(X<I>)" we need to evaluate "I". */
11996 /* First, determine the context for the type we are looking
11997 up. */
12000 {
12003 /* If context is a nested class inside a class template,
12004 it may still need to be instantiated (c++/33959). */
12006 }
12008 /* Then, figure out what arguments are appropriate for the
12009 type we are trying to find. For example, given:
12011 template <class T> struct S;
12012 template <class T, class U> void f(T, U) { S<U> su; }
12014 and supposing that we are instantiating f<int, double>,
12015 then our ARGS will be {int, double}, but, when looking up
12016 S we only want {double}. */
12021 else
12022 {
12026 }
12032 }
12033 else
12034 /* This is not a template type, so there's nothing to do. */
12039 }
12040 }
12044 /* Substitute into the default argument ARG (a default argument for
12045 FN), which has the indicated TYPE. */
12047 tree
12049 tsubst_flags_t complain)
12050 {
12055 /* This can happen in invalid code. */
12070 /* This default argument came from a template. Instantiate the
12071 default argument here, not in tsubst. In the case of
12072 something like:
12074 template <class T>
12075 struct S {
12076 static T t();
12077 void f(T = t());
12078 };
12080 we must be careful to do name lookup in the scope of S<T>,
12081 rather than in the current class. */
12083 /* The "this" pointer is not valid in a default argument. */
12085 {
12090 }
12095 /* The default argument expression may cause implicitly defined
12096 member functions to be synthesized, which will result in garbage
12097 collection. We must treat this situation as if we were within
12098 the body of function so as to avoid collecting live data on the
12099 stack. */
12109 /* Restore the "this" pointer. */
12111 {
12114 }
12121 /* Make sure the default argument is reasonable. */
12127 {
12131 }
12134 }
12136 /* Substitute into all the default arguments for FN. */
12138 static void
12140 {
12141 tree arg;
12142 tree tmpl_args;
12146 /* If this function is not yet instantiated, we certainly don't need
12147 its default arguments. */
12150 /* Don't do this again for clones. */
12156 arg;
12162 complain);
12163 }
12165 /* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
12167 static tree
12169 tree lambda_fntype)
12170 {
12175 /* Nobody should be tsubst'ing into non-template functions. */
12179 {
12180 /* If T is not dependent, just return it. */
12184 /* Calculate the most general template of which R is a
12185 specialization, and the complete set of arguments used to
12186 specialize R. */
12189 (DECL_TEMPLATE_RESULT
12195 /* Check to see if we already have this specialization. */
12197 {
12201 }
12203 /* We can see more levels of arguments than parameters if
12204 there was a specialization of a member template, like
12205 this:
12207 template <class T> struct S { template <class U> void f(); }
12208 template <> template <class U> void S<int>::f(U);
12210 Here, we'll be substituting into the specialization,
12211 because that's where we can find the code we actually
12212 want to generate, but we'll have enough arguments for
12213 the most general template.
12215 We also deal with the peculiar case:
12217 template <class T> struct S {
12218 template <class U> friend void f();
12219 };
12220 template <class U> void f() {}
12221 template S<int>;
12222 template void f<double>();
12224 Here, the ARGS for the instantiation of will be {int,
12225 double}. But, we only need as many ARGS as there are
12226 levels of template parameters in CODE_PATTERN. We are
12227 careful not to get fooled into reducing the ARGS in
12228 situations like:
12230 template <class T> struct S { template <class U> void f(U); }
12231 template <class T> template <> void S<T>::f(int) {}
12233 which we can spot because the pattern will be a
12234 specialization in this case. */
12241 }
12242 else
12243 {
12244 /* This special case arises when we have something like this:
12246 template <class T> struct S {
12247 friend void f<int>(int, double);
12248 };
12250 Here, the DECL_TI_TEMPLATE for the friend declaration
12251 will be an IDENTIFIER_NODE. We are being called from
12252 tsubst_friend_function, and we want only to create a
12253 new decl (R) with appropriate types so that we can call
12254 determine_specialization. */
12257 }
12274 /* If we hit excessive deduction depth, the type is bogus even if
12275 it isn't error_mark_node, so don't build a decl. */
12279 /* We do NOT check for matching decls pushed separately at this
12280 point, as they may not represent instantiations of this
12281 template, and in any case are considered separate under the
12282 discrete model. */
12286 /* Clear out the mangled name and RTL for the instantiation. */
12289 /* Leave DECL_INITIAL set on deleted instantiations. */
12294 /* OpenMP UDRs have the only argument a reference to the declared
12295 type. We want to diagnose if the declared type is a reference,
12296 which is invalid, but as references to references are usually
12297 quietly merged, diagnose it here. */
12299 {
12300 tree argtype
12305 "reference type %qT in "
12309 argtype);
12310 }
12313 /* Type-conversion operator. Reconstruct the name, in
12314 case it's the name of one of the template's parameters. */
12324 {
12328 }
12335 /* If this is an instantiation of a function with internal
12336 linkage, we already know what object file linkage will be
12337 assigned to the instantiation. */
12346 /* We'll re-clone as appropriate in instantiate_template. */
12349 /* If we aren't complaining now, return on error before we register
12350 the specialization so that we'll complain eventually. */
12356 /* When instantiating a constrained member, substitute
12357 into the constraints to create a new constraint. */
12360 {
12363 }
12365 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12366 this in the special friend case mentioned above where
12367 GEN_TMPL is NULL. */
12369 {
12374 tree new_r
12377 /* We instantiated this while substituting into
12378 the type earlier (template/friend54.C). */
12381 /* We're not supposed to instantiate default arguments
12382 until they are called, for a template. But, for a
12383 declaration like:
12385 template <class T> void f ()
12386 { extern void g(int i = T()); }
12388 we should do the substitution when the template is
12389 instantiated. We handle the member function case in
12390 instantiate_class_template since the default arguments
12391 might refer to other members of the class. */
12396 }
12397 else
12400 /* Copy the list of befriending classes. */
12404 {
12408 }
12411 {
12415 /* If this is an instantiation of a member template, clone it.
12416 If it isn't, that'll be handled by
12417 clone_constructors_and_destructors. */
12420 }
12431 /* Possibly limit visibility based on template args. */
12434 {
12438 }
12447 }
12449 /* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
12451 static tree
12453 tree lambda_fntype)
12454 {
12455 /* We can get here when processing a member function template,
12456 member class template, or template template parameter. */
12459 tree spec;
12460 tree tmpl_args;
12461 tree full_args;
12462 tree r;
12466 {
12467 /* Template template parameter is treated here. */
12471 /* If we get a real template back, return it. This can happen in
12472 the context of most_specialized_partial_spec. */
12475 else
12476 /* The new TEMPLATE_DECL was built in
12477 reduce_template_parm_level. */
12480 }
12483 {
12484 /* We might already have an instance of this template.
12485 The ARGS are for the surrounding class type, so the
12486 full args contain the tsubst'd args for the context,
12487 plus the innermost args from the template decl. */
12491 /* Because this is a template, the arguments will still be
12492 dependent, even after substitution. If
12493 PROCESSING_TEMPLATE_DECL is not set, the dependency
12494 predicates will short-circuit. */
12502 /* If this is a default template template argument,
12503 tsubst might not have changed anything. */
12511 }
12513 /* Make a new template decl. It will be similar to the
12514 original, but will record the current template arguments.
12515 We also create a new function declaration, which is just
12516 like the old one, but points to this new template, rather
12517 than the old one. */
12522 // Build new template info linking to the original template decl.
12524 {
12527 }
12528 else
12531 /* The template parameters for this new template are all the
12532 template parameters for the old template, except the
12533 outermost level of parameters. */
12536 complain);
12540 {
12541 tree new_type;
12549 /* For a partial specialization, we need to keep pointing to
12550 the primary template. */
12556 }
12557 else
12558 {
12559 tree new_decl;
12563 else
12573 {
12576 }
12577 else
12578 {
12581 }
12582 }
12592 /* Record this non-type partial instantiation. */
12598 }
12600 /* Substitute the ARGS into the T, which is a _DECL. Return the
12601 result of the substitution. Issue error and warning messages under
12602 control of COMPLAIN. */
12604 static tree
12606 {
12607 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12608 location_t saved_loc;
12613 /* Set the filename and linenumber to improve error-reporting. */
12618 {
12628 {
12636 {
12637 /* If there is a local specialization that isn't a
12638 parameter pack, it means that we're doing a "simple"
12639 substitution from inside tsubst_pack_expansion. Just
12640 return the local specialization (which will be a single
12641 parm). */
12648 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12649 the parameters in this function parameter pack. */
12653 {
12656 /* Zero-length parameter packs are boring. Just substitute
12657 into the chain. */
12661 }
12662 else
12663 {
12664 /* All we did was update the type. Make a note of that. */
12667 }
12668 }
12670 /* Loop through all of the parameters we'll build. When T is
12671 a function parameter pack, LEN is the number of expanded
12672 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12675 {
12682 /* We're on the Ith parameter of the function parameter
12683 pack. */
12684 {
12685 /* Get the Ith type. */
12688 /* Rename the parameter to include the index. */
12691 }
12693 /* We're dealing with a normal parameter. */
12701 {
12704 else
12707 }
12717 /* Keep track of the first new parameter we
12718 generate. That's what will be returned to the
12719 caller. */
12723 /* Build a proper chain of parameters when substituting
12724 into a function parameter pack. */
12727 }
12729 /* If cp_unevaluated_operand is set, we're just looking for a
12730 single dummy parameter, so don't keep going. */
12735 /* FIRST_R contains the start of the chain we've built. */
12737 }
12741 {
12748 {
12749 /* This field is a lambda capture pack. Return a TREE_VEC of
12750 the expanded fields to instantiate_class_template_1 and
12751 store them in the specializations hash table as a
12752 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12756 {
12759 }
12760 else
12761 {
12762 /* All we did was update the type. Make a note of that. */
12765 }
12766 }
12769 {
12772 {
12776 }
12786 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12787 non-bit-fields DECL_INITIAL is a non-static data member
12788 initializer, which gets deferred instantiation. */
12794 {
12795 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12796 NSDMI in perform_member_init. Still set DECL_INITIAL
12797 so that we know there is one. */
12802 }
12803 /* We don't have to set DECL_CONTEXT here; it is set by
12804 finish_member_declaration. */
12812 }
12815 {
12820 }
12821 }
12825 /* We reach here only for member using decls. We also need to check
12826 uses_template_parms because DECL_DEPENDENT_P is not set for a
12827 using-declaration that designates a member of the current
12828 instantiation (c++/53549). */
12831 {
12835 {
12840 {
12844 {
12847 }
12848 else
12849 {
12852 }
12854 }
12855 }
12856 else
12857 {
12863 else
12864 {
12867 }
12868 }
12869 }
12870 else
12871 {
12874 }
12879 {
12882 tree spec;
12884 tree ctx;
12893 {
12894 /* If this is the canonical decl, we don't have to
12895 mess with instantiations, and often we can't (for
12896 typename, template type parms and such). Note that
12897 TYPE_NAME is not correct for the above test if
12898 we've copied the type for a typedef. */
12904 }
12906 /* Check to see if we already have the specialization we
12907 need. */
12910 {
12911 /* T is a static data member or namespace-scope entity.
12912 We have to substitute into namespace-scope variables
12913 (not just variable templates) because of cases like:
12915 template <class T> void f() { extern T t; }
12917 where the entity referenced is not known until
12918 instantiation time. */
12922 {
12924 complain,
12926 /* If CTX is unchanged, then T is in fact the
12927 specialization we want. That situation occurs when
12928 referencing a static data member within in its own
12929 class. We can use pointer equality, rather than
12930 same_type_p, because DECL_CONTEXT is always
12931 canonical... */
12933 /* ... unless T is a member template; in which
12934 case our caller can be willing to create a
12935 specialization of that template represented
12936 by T. */
12940 }
12943 {
12948 argvec = (coerce_innermost_template_parms
12956 }
12957 }
12958 else
12959 {
12960 /* A local variable. */
12962 /* Subsequent calls to pushdecl will fill this in. */
12964 /* Unless this is a reference to a static variable from an
12965 enclosing function, in which case we need to fill it in now. */
12967 {
12971 }
12973 }
12974 /* If we already have the specialization we need, there is
12975 nothing more to do. */
12977 {
12980 }
12982 /* Create a new node for the specialization we need. */
12985 {
12988 else
12997 /* Mask off any template args past the variable's context so we
12998 don't replace the auto with an unrelated argument. */
13003 }
13005 {
13006 /* Even if the original location is out of scope, the
13007 newly substituted one is not. */
13014 {
13015 /* It may seem that this case cannot occur, since:
13017 typedef void f();
13018 void g() { f x; }
13020 declares a function, not a variable. However:
13022 typedef void f();
13023 template <typename T> void g() { T t; }
13024 template void g<f>();
13026 is an attempt to declare a variable with function
13027 type. */
13029 /* R is not yet sufficiently initialized, so we
13030 just use its name. */
13033 }
13035 /* Wait until cp_finish_decl to set this again, to handle
13036 circular dependency (template/instantiate6.C). */
13041 {
13046 {
13049 }
13051 }
13055 }
13061 /* Clear out the mangled name and RTL for the instantiation. */
13065 /* The initializer must not be expanded until it is required;
13066 see [temp.inst]. */
13070 {
13073 /* Possibly limit visibility based on template args. */
13076 {
13080 }
13082 }
13085 {
13086 /* A static data member declaration is always marked
13087 external when it is declared in-class, even if an
13088 initializer is present. We mimic the non-template
13089 processing here. */
13097 }
13098 else
13099 {
13104 }
13112 /* Preserve a typedef that names a type. */
13114 {
13118 /* An alias template specialization can be dependent
13119 even if its underlying type is not. */
13121 }
13124 }
13129 }
13130 #undef RETURN
13132 out:
13133 /* Restore the file and line information. */
13137 }
13139 /* Substitute into the ARG_TYPES of a function type.
13140 If END is a TREE_CHAIN, leave it and any following types
13141 un-substituted. */
13143 static tree
13145 tree args,
13146 tree end,
13147 tsubst_flags_t complain,
13148 tree in_decl)
13149 {
13150 tree remaining_arg_types;
13154 tree default_arg;
13165 {
13166 /* For a pack expansion, perform substitution on the
13167 entire expression. Later on, we'll handle the arguments
13168 one-by-one. */
13173 /* So that we'll spin through the parameters, one by one. */
13175 else
13176 {
13177 /* We only partially substituted into the parameter
13178 pack. Our type is TYPE_PACK_EXPANSION. */
13181 }
13182 }
13195 {
13197 {
13201 }
13203 }
13204 /* DR 657. */
13208 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13209 top-level qualifiers as required. */
13212 /* We do not substitute into default arguments here. The standard
13213 mandates that they be instantiated only when needed, which is
13214 done in build_over_call. */
13218 {
13219 /* We've instantiated a template before its default arguments
13220 have been parsed. This can happen for a nested template
13221 class, and is not an error unless we require the default
13222 argument in a call of this function. */
13223 remaining_arg_types =
13226 }
13227 else
13228 remaining_arg_types =
13230 }
13233 }
13235 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13236 *not* handle the exception-specification for FNTYPE, because the
13237 initial substitution of explicitly provided template parameters
13238 during argument deduction forbids substitution into the
13239 exception-specification:
13241 [temp.deduct]
13243 All references in the function type of the function template to the
13244 corresponding template parameters are replaced by the specified tem-
13245 plate argument values. If a substitution in a template parameter or
13246 in the function type of the function template results in an invalid
13247 type, type deduction fails. [Note: The equivalent substitution in
13248 exception specifications is done only when the function is instanti-
13249 ated, at which point a program is ill-formed if the substitution
13250 results in an invalid type.] */
13252 static tree
13254 tree args,
13255 tsubst_flags_t complain,
13256 tree in_decl)
13257 {
13258 tree return_type;
13260 tree fntype;
13262 /* The TYPE_CONTEXT is not used for function/method types. */
13265 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13266 failure. */
13270 {
13271 /* Substitute the argument types. */
13283 {
13284 /* DR 1207: 'this' is in scope in the trailing return type. */
13286 }
13288 /* Substitute the return type. */
13292 {
13295 }
13296 }
13297 else
13298 /* Substitute the return type. */
13303 /* DR 486 clarifies that creation of a function type with an
13304 invalid return type is a deduction failure. */
13307 {
13309 {
13312 else
13314 }
13316 }
13317 /* And DR 657. */
13322 {
13323 /* Substitute the argument types. */
13328 }
13330 /* Construct a new type node and return it. */
13332 {
13337 }
13338 else
13339 {
13341 /* Don't pick up extra function qualifiers from the basetype. */
13344 {
13345 /* [temp.deduct]
13347 Type deduction may fail for any of the following
13348 reasons:
13350 -- Attempting to create "pointer to member of T" when T
13351 is not a class type. */
13354 r);
13356 }
13361 }
13368 }
13370 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13371 ARGS into that specification, and return the substituted
13372 specification. If there is no specification, return NULL_TREE. */
13374 static tree
13376 tree args,
13377 tsubst_flags_t complain,
13378 tree in_decl,
13380 {
13381 tree specs;
13382 tree new_specs;
13387 {
13388 /* A noexcept-specifier. */
13393 {
13394 /* Defer instantiation of noexcept-specifiers to avoid
13395 excessive instantiations (c++/49107). */
13398 {
13399 /* We already partially instantiated this member template,
13400 so combine the new args with the old. */
13405 }
13406 else
13407 {
13410 }
13411 }
13412 else
13413 new_specs = tsubst_copy_and_build
13417 }
13419 {
13422 else
13424 {
13425 tree spec;
13430 {
13431 /* Expand the pack expansion type. */
13434 in_decl);
13440 else
13441 {
13442 /* We're substituting into a member template, so
13443 we got a TYPE_PACK_EXPANSION back. Add that
13444 expansion and move on. */
13448 expanded_specs,
13449 complain);
13452 }
13453 }
13456 {
13459 else
13464 complain);
13465 }
13468 }
13469 }
13471 }
13473 /* Take the tree structure T and replace template parameters used
13474 therein with the argument vector ARGS. IN_DECL is an associated
13475 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13476 Issue error and warning messages under control of COMPLAIN. Note
13477 that we must be relatively non-tolerant of extensions here, in
13478 order to preserve conformance; if we allow substitutions that
13479 should not be allowed, we may allow argument deductions that should
13480 not succeed, and therefore report ambiguous overload situations
13481 where there are none. In theory, we could allow the substitution,
13482 but indicate that it should have failed, and allow our caller to
13483 make sure that the right thing happens, but we don't try to do this
13484 yet.
13486 This function is used for dealing with types, decls and the like;
13487 for expressions, use tsubst_expr or tsubst_copy. */
13489 tree
13491 {
13514 else
13519 /* Reuse typedefs. We need to do this to handle dependent attributes,
13520 such as attribute aligned. */
13523 {
13527 {
13528 /* DECL represents an alias template and we want to
13529 instantiate it. */
13533 }
13537 {
13541 }
13546 else
13547 /* The typedef is from a non-template context. */
13551 {
13553 r = cp_build_qualified_type_real
13557 }
13558 else
13559 {
13560 /* We don't have an instantiation yet, so drop the typedef. */
13565 }
13566 }
13583 {
13609 {
13615 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13616 needed. */
13622 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13623 with TREE_SIDE_EFFECTS that indicates this is not an integral
13624 constant expression. */
13627 {
13630 }
13633 }
13639 {
13645 /* Early in template argument deduction substitution, we don't
13646 want to reduce the level of 'auto', or it will be confused
13647 with a normal template parm in subsequent deduction. */
13659 {
13663 {
13664 /* See through ARGUMENT_PACK_SELECT arguments. */
13666 /* If the selected argument is an expansion E, that most
13667 likely means we were called from
13668 gen_elem_of_pack_expansion_instantiation during the
13669 substituting of pack an argument pack (which Ith
13670 element is a pack expansion, where I is
13671 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13672 In this case, the Ith element resulting from this
13673 substituting is going to be a pack expansion, which
13674 pattern is the pattern of E. Let's return the
13675 pattern of E, and
13676 gen_elem_of_pack_expansion_instantiation will
13677 build the resulting pack expansion from it. */
13679 {
13680 /* Make sure we aren't throwing away arg info. */
13683 }
13684 }
13685 }
13690 {
13692 /* If ARG is an argument pack, we don't actually want to
13693 perform a substitution here, because substitutions
13694 for argument packs are only done
13695 element-by-element. We can get to this point when
13696 substituting the type of a non-type template
13697 parameter pack, when that type actually contains
13698 template parameter packs from an outer template, e.g.,
13700 template<typename... Types> struct A {
13701 template<Types... Values> struct B { };
13702 }; */
13706 {
13712 return cp_build_qualified_type_real
13714 }
13716 {
13717 /* We are processing a type constructed from a
13718 template template parameter. */
13729 /* Consider this code:
13731 template <template <class> class Template>
13732 struct Internal {
13733 template <class Arg> using Bind = Template<Arg>;
13734 };
13736 template <template <class> class Template, class Arg>
13737 using Instantiate = Template<Arg>; //#0
13739 template <template <class> class Template,
13740 class Argument>
13741 using Bind =
13742 Instantiate<Internal<Template>::template Bind,
13743 Argument>; //#1
13745 When #1 is parsed, the
13746 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13747 parameter `Template' in #0 matches the
13748 UNBOUND_CLASS_TEMPLATE representing the argument
13749 `Internal<Template>::template Bind'; We then want
13750 to assemble the type `Bind<Argument>' that can't
13751 be fully created right now, because
13752 `Internal<Template>' not being complete, the Bind
13753 template cannot be looked up in that context. So
13754 we need to "store" `Bind<Argument>' for later
13755 when the context of Bind becomes complete. Let's
13756 store that in a TYPENAME_TYPE. */
13760 argvec),
13761 typename_type,
13762 complain);
13764 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13765 are resolving nested-types in the signature of a
13766 member function templates. Otherwise ARG is a
13767 TEMPLATE_DECL and is the real template to be
13768 instantiated. */
13776 complain);
13777 return cp_build_qualified_type_real
13779 }
13782 else
13783 /* TEMPLATE_PARM_INDEX. */
13785 }
13788 /* This can happen during the attempted tsubst'ing in
13789 unify. This means that we don't yet have any information
13790 about the template parameter in question. */
13793 /* If we get here, we must have been looking at a parm for a
13794 more deeply nested template. Make a new version of this
13795 template parameter, but with a lower level. */
13797 {
13802 {
13804 r = cp_build_qualified_type_real
13808 }
13815 /* Break infinite recursion when substituting the constraints
13817 else
13818 {
13829 {
13830 /* Propagate constraints on placeholders. */
13835 {
13839 }
13840 }
13843 /* We have reduced the level of the template
13844 template parameter, but not the levels of its
13845 template parameters, so canonical_type_parameter
13846 will not be able to find the canonical template
13847 template parameter for this level. Thus, we
13848 require structural equality checking to compare
13849 TEMPLATE_TEMPLATE_PARMs. */
13853 else
13857 {
13859 /* We might need to substitute into the types of non-type
13860 template parameters. */
13872 }
13873 }
13877 /* OK, now substitute the type of the non-type parameter. We
13878 couldn't do it earlier because it might be an auto parameter,
13879 and we wouldn't need to if we had an argument. */
13888 }
13891 }
13894 {
13902 {
13906 }
13909 {
13913 }
13916 {
13920 }
13926 }
13929 /* We should never be tsubsting a binfo. */
13933 /* A vector of template arguments. */
13939 {
13943 /* [temp.deduct]
13945 Type deduction may fail for any of the following
13946 reasons:
13948 -- Attempting to create a pointer to reference type.
13949 -- Attempting to create a reference to a reference type or
13950 a reference to void.
13952 Core issue 106 says that creating a reference to a reference
13953 during instantiation is no longer a cause for failure. We
13954 only enforce this check in strict C++98 mode. */
13958 {
13961 /* We keep track of the last time we issued this error
13962 message to avoid spewing a ton of messages during a
13963 single bad template instantiation. */
13966 {
13971 else
13974 }
13977 }
13981 {
13983 {
13986 type);
13987 else
13989 type);
13990 }
13992 }
13994 {
13998 }
14000 /* In C++0x, during template argument substitution, when there is an
14001 attempt to create a reference to a reference type, reference
14002 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
14004 "If a template-argument for a template-parameter T names a type
14005 that is a reference to a type A, an attempt to create the type
14006 'lvalue reference to cv T' creates the type 'lvalue reference to
14007 A,' while an attempt to create the type type rvalue reference to
14008 cv T' creates the type T"
14009 */
14010 r = cp_build_reference_type
14013 else
14018 /* Will this ever be needed for TYPE_..._TO values? */
14022 }
14024 {
14027 {
14028 /* [temp.deduct]
14030 Type deduction may fail for any of the following
14031 reasons:
14033 -- Attempting to create "pointer to member of T" when T
14034 is not a class type. */
14038 }
14040 {
14044 }
14046 {
14050 }
14053 {
14054 /* The type of the implicit object parameter gets its
14055 cv-qualifiers from the FUNCTION_TYPE. */
14056 tree memptr;
14057 tree method_type
14062 complain);
14063 }
14064 else
14067 complain);
14068 }
14071 {
14072 tree fntype;
14073 tree specs;
14078 /* Substitute the exception specification. */
14086 }
14088 {
14093 /* As an optimization, we avoid regenerating the array type if
14094 it will obviously be the same as T. */
14098 /* These checks should match the ones in create_array_type_for_decl.
14100 [temp.deduct]
14102 The deduction may fail for any of the following reasons:
14104 -- Attempting to create an array with an element type that
14105 is void, a function type, or a reference type, or [DR337]
14106 an abstract class type. */
14112 {
14116 }
14124 {
14127 }
14130 }
14133 {
14145 {
14149 }
14151 {
14152 /* Normally, make_typename_type does not require that the CTX
14153 have complete type in order to allow things like:
14155 template <class T> struct S { typename S<T>::X Y; };
14157 But, such constructs have already been resolved by this
14158 point, so here CTX really should have complete type, unless
14159 it's a partial instantiation. */
14162 {
14166 }
14167 }
14174 {
14177 }
14180 {
14182 {
14186 else
14188 }
14190 {
14194 else
14196 }
14197 }
14199 return cp_build_qualified_type_real
14201 }
14204 {
14216 }
14219 {
14220 tree type;
14236 complain);
14237 }
14240 {
14241 tree type;
14252 {
14254 {
14258 }
14261 }
14272 else
14273 {
14277 /* In a template ~id could be either a complement expression
14278 or an unqualified-id naming a destructor; if instantiating
14279 it produces an expression, it's not an id-expression or
14280 member access. */
14283 }
14288 }
14291 {
14295 }
14299 {
14300 tree r;
14304 else
14312 }
14327 /* We should use one of the expression tsubsts for these codes. */
14333 }
14334 }
14336 /* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
14337 expression on the left-hand side of the "." or "->" operator. A
14338 baselink indicates a function from a base class. Both the
14339 BASELINK_ACCESS_BINFO and the base class referenced may indicate
14340 bases of the template class, rather than the instantiated class.
14341 In addition, lookups that were not ambiguous before may be
14342 ambiguous now. Therefore, we perform the lookup again. */
14344 static tree
14347 {
14360 {
14367 }
14375 {
14380 }
14382 /* If lookup found a single function, mark it as used at this point.
14383 (If it lookup found multiple functions the one selected later by
14384 overload resolution will be marked as used at that point.) */
14392 {
14393 /* Add back the template arguments, if present. */
14399 /* Update the conversion operator type. */
14401 }
14407 {
14409 qualifying_scope,
14410 object_type);
14412 /* We need to call adjust_result_of_qualified_name_lookup in case the
14413 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14414 so that we still get virtual function binding. */
14416 }
14419 }
14421 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14422 true if the qualified-id will be a postfix-expression in-and-of
14423 itself; false if more of the postfix-expression follows the
14424 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14425 of "&". */
14427 static tree
14431 {
14432 tree expr;
14433 tree scope;
14434 tree name;
14436 tree template_args;
14441 /* Figure out what name to look up. */
14444 {
14454 }
14455 else
14456 {
14459 }
14461 /* Substitute into the qualifying scope. When there are no ARGS, we
14462 are just trying to simplify a non-dependent expression. In that
14463 case the qualifying scope may be dependent, and, in any case,
14464 substituting will not help. */
14467 {
14470 }
14471 else
14475 {
14482 }
14485 {
14487 {
14488 /* A BIT_NOT_EXPR is used to represent a destructor. */
14490 {
14494 }
14495 else
14498 }
14499 else
14503 {
14505 {
14509 }
14511 }
14512 }
14515 {
14517 scope);
14518 /* Remember that there was a reference to this entity. */
14521 }
14524 {
14530 }
14533 {
14536 complain);
14537 else
14539 }
14545 {
14546 expr = (adjust_result_of_qualified_name_lookup
14548 expr = (finish_qualified_id_expr
14552 }
14554 /* Expressions do not generally have reference type. */
14556 /* However, if we're about to form a pointer-to-member, we just
14557 want the referenced member referenced. */
14565 }
14567 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14568 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14569 for tsubst. */
14571 static tree
14574 {
14581 {
14582 /* If we had an initializer but it
14583 instantiated to nothing,
14584 value-initialize the object. This will
14585 only occur when the initializer was a
14586 pack expansion where the parameter packs
14587 used in that expansion were of length
14588 zero. */
14590 complain);
14595 }
14598 }
14600 /* Like tsubst, but deals with expressions. This function just replaces
14601 template parms; to finish processing the resultant expression, use
14602 tsubst_copy_and_build or tsubst_expr. */
14604 static tree
14606 {
14608 tree r;
14616 {
14621 {
14622 /* We get here for a use of 'this' in an NSDMI. */
14626 /* This can happen for a parameter name used later in a function
14627 declaration (such as in a late-specified return type). Just
14628 make a dummy decl, since it's only used for its type. */
14631 /* Give it the template pattern as its context; its true context
14632 hasn't been instantiated yet and this is good enough for
14633 mangling. */
14635 }
14644 {
14645 tree enum_type;
14646 tree v;
14650 /* There is no need to substitute into namespace-scope
14651 enumerators. */
14654 /* If ARGS is NULL, then T is known to be non-dependent. */
14658 /* Unfortunately, we cannot just call lookup_name here.
14659 Consider:
14661 template <int I> int f() {
14662 enum E { a = I };
14663 struct S { void g() { E e = a; } };
14664 };
14666 When we instantiate f<7>::S::g(), say, lookup_name is not
14667 clever enough to find f<7>::a. */
14668 enum_type
14678 /* We didn't find the name. That should never happen; if
14679 name-lookup found it during preliminary parsing, we
14680 should find it again here during instantiation. */
14682 }
14687 {
14688 /* Check for a local specialization set up by
14689 tsubst_pack_expansion. */
14691 {
14695 }
14697 /* When retrieving a capture pack from a generic lambda, remove the
14698 lambda call op's own template argument list from ARGS. Only the
14699 template arguments active for the closure type should be used to
14700 retrieve the pack specialization. */
14706 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14707 tsubst_decl put in the hash table. */
14709 }
14712 {
14713 tree ctx;
14718 {
14721 {
14725 }
14727 }
14728 }
14738 {
14741 {
14742 /* First try name lookup to find the instantiation. */
14745 {
14746 /* Make sure that the one we found is the one we want. */
14752 }
14756 else
14757 {
14758 /* This can happen for a variable used in a
14759 late-specified return type of a local lambda, or for a
14760 local static or constant. Building a new VAR_DECL
14761 should be OK in all those cases. */
14764 /* Avoid infinite recursion (79640). */
14767 {
14768 /* We can't call cp_finish_decl, so handle the
14769 initializer by hand. */
14784 }
14791 }
14792 /* Remember this for subsequent uses. */
14795 }
14796 }
14797 else
14807 /* An OVERLOAD will always be a non-dependent overload set; an
14808 overload set from function scope will just be represented with an
14809 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14811 /* We must have marked any lookups as persistent. */
14827 {
14828 /* Template template argument like the following example need
14829 special treatment:
14831 template <template <class> class TT> struct C {};
14832 template <class T> struct D {
14833 template <class U> struct E {};
14834 C<E> c; // #1
14835 };
14836 D<int> d; // #2
14838 We are processing the template argument `E' in #1 for
14839 the template instantiation #2. Originally, `E' is a
14840 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14841 have to substitute this with one having context `D<int>'. */
14845 {
14846 /* When rewriting a constructor into a deduction guide, a
14847 non-dependent name can become dependent, so memtmpl<args>
14848 becomes context::template memtmpl<args>. */
14852 }
14854 }
14855 else
14856 /* Ordinary template template argument. */
14867 {
14871 }
14876 {
14885 /* We only want to compute the number of arguments. */
14888 else
14895 {
14897 /* Set TREE_USED for the benefit of -Wunused. */
14901 }
14909 {
14914 else
14920 else
14923 }
14924 else
14926 }
14928 {
14936 }
14937 /* Fall through */
14953 {
14957 }
14960 {
14961 tree object;
14962 tree name;
14967 {
14971 }
14974 {
14984 }
14989 in_decl);
14990 else
14993 }
15031 {
15035 }
15038 {
15043 }
15046 {
15050 }
15053 {
15061 }
15067 {
15074 }
15077 {
15084 }
15087 {
15094 }
15097 {
15098 /* Substituted template arguments */
15107 }
15110 {
15130 }
15155 /* Fall through. */
15158 {
15161 }
15162 else
15166 /* This is handled by tsubst_copy_and_build. */
15170 {
15174 }
15177 /* We shouldn't have built any of these during initial template
15178 generation. Instead, they should be built during instantiation
15179 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15183 {
15193 }
15211 {
15212 /* Instantiate any typedefs in the type. */
15217 }
15220 /* These can sometimes show up in a partial instantiation, but never
15221 involve template parms. */
15237 /* We shouldn't get here, but keep going if !flag_checking. */
15241 }
15242 }
15244 /* Helper function for tsubst_omp_clauses, used for instantiation of
15245 OMP_CLAUSE_DECL of clauses. */
15247 static tree
15249 tree in_decl)
15250 {
15254 /* Handle an OpenMP array section represented as a TREE_LIST (or
15255 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15256 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15257 TREE_LIST. We can handle it exactly the same as an array section
15258 (purpose, value, and a chain), even though the nomenclature
15259 (low_bound, length, etc) is different. */
15261 {
15262 tree low_bound
15268 in_decl);
15277 }
15280 /* Undo convert_from_reference tsubst_expr could have called. */
15286 }
15288 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15290 static tree
15293 {
15298 {
15304 {
15307 {
15313 }
15314 /* FALLTHRU */
15329 in_decl);
15361 {
15364 {
15371 }
15372 else
15374 }
15377 in_decl);
15383 in_decl);
15391 in_decl);
15393 {
15396 }
15401 else
15404 in_decl,
15428 }
15431 {
15441 /* tsubst_expr on SCOPE_REF results in returning
15442 finish_non_static_data_member result. Undo that here. */
15446 {
15451 {
15455 CASE_CONVERT:
15464 /* FALLTHRU */
15468 }
15469 }
15475 {
15478 {
15481 }
15482 }
15486 }
15487 }
15491 {
15496 {
15499 }
15500 }
15502 }
15504 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15506 static tree
15508 tree in_decl)
15509 {
15510 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15530 {
15533 else
15534 {
15538 }
15539 }
15544 #undef RECUR
15545 }
15547 /* Used to temporarily communicate the list of #pragma omp parallel
15548 clauses to #pragma omp for instantiation if they are combined
15549 together. */
15553 /* Substitute one OMP_FOR iterator. */
15555 static void
15560 {
15561 #define RECUR(NODE) \
15562 tsubst_expr ((NODE), args, complain, in_decl, \
15563 integral_constant_expression_p)
15570 {
15573 }
15579 {
15580 /* We need to jump through some hoops to handle declarations in the
15581 init-statement, since we might need to handle auto deduction,
15582 but we need to keep control of initialization. */
15586 }
15587 else
15588 {
15590 {
15593 {
15597 {
15601 CASE_CONVERT:
15609 {
15612 }
15613 /* FALLTHRU */
15617 }
15618 }
15619 }
15620 else
15622 }
15633 {
15635 {
15636 /* Declare the variable, but don't let that initialize it. */
15641 }
15646 {
15651 }
15652 else
15659 }
15662 {
15663 /* Declare and initialize the variable. */
15666 }
15668 {
15672 {
15674 {
15680 {
15683 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15688 }
15691 {
15693 decl);
15695 }
15698 {
15700 decl);
15702 }
15703 else
15705 }
15708 }
15710 {
15715 {
15718 }
15719 }
15720 }
15723 {
15727 }
15728 else
15732 {
15743 {
15751 }
15752 else
15758 {
15764 }
15768 {
15776 }
15777 else
15783 }
15789 #undef RECUR
15790 }
15792 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15793 of OMP_TARGET's body. */
15795 static tree
15797 {
15800 {
15809 }
15811 }
15813 /* Helper function for tsubst_expr. For decomposition declaration
15814 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15815 also the corresponding decls representing the identifiers
15816 of the decomposition declaration. Return DECL if successful
15817 or error_mark_node otherwise, set *FIRST to the first decl
15818 in the list chained through DECL_CHAIN and *CNT to the number
15819 of such decls. */
15821 static tree
15825 {
15830 decl2
15835 {
15837 {
15840 }
15857 {
15860 }
15861 else
15863 }
15866 }
15868 /* Like tsubst_copy for expressions, etc. but also does semantic
15869 processing. */
15871 tree
15874 {
15875 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15876 #define RECUR(NODE) \
15877 tsubst_expr ((NODE), args, complain, in_decl, \
15878 integral_constant_expression_p)
15881 tree r;
15882 location_t loc;
15894 {
15896 {
15897 tree_stmt_iterator i;
15901 }
15916 else
15926 {
15928 tree init;
15934 {
15944 else
15946 }
15948 {
15949 /* Don't build up decls for a variadic capture proxy, we'll
15950 instantiate the elements directly as needed. */
15952 }
15955 {
15956 /* We're in tsubst_lambda_expr, we've already inserted new capture
15957 proxies, and uses will find them with lookup_name. */
15959 }
15962 /* Don't copy the old closure; we'll create a new one in
15963 tsubst_lambda_expr. */
15965 else
15966 {
15970 {
15971 /* By marking the declaration as instantiated, we avoid
15972 trying to instantiate it. Since instantiate_decl can't
15973 handle local variables, and since we've already done
15974 all that needs to be done, that's the right thing to
15975 do. */
15980 /* Anonymous aggregates are a special case. */
15983 {
15986 {
15990 }
15992 }
15998 {
16003 }
16004 else
16005 {
16010 {
16011 /* For __PRETTY_FUNCTION__ we have to adjust the
16012 initializer. */
16016 }
16017 else
16021 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
16027 {
16029 tree first;
16035 }
16036 }
16037 }
16038 }
16041 }
16056 {
16064 {
16066 tree first;
16071 }
16072 else
16077 }
16103 else
16104 {
16111 }
16117 {
16126 }
16134 else
16142 else
16163 {
16170 }
16174 {
16176 tree label;
16183 }
16189 /* Computed goto's must be tsubst'd into. On the other hand,
16190 non-computed gotos must not be; the identifier in question
16191 will have no binding. */
16193 else
16199 {
16215 }
16220 {
16225 }
16226 else
16227 {
16232 else
16239 else
16245 else
16247 }
16251 {
16255 {
16257 /* Prevent instantiate_decl from trying to instantiate
16258 this variable. We've already done all that needs to be
16259 done. */
16262 }
16267 }
16273 {
16274 /* Local classes are not independent templates; they are
16275 instantiated along with their containing function. And this
16276 way we don't have to deal with pushing out of one local class
16277 to instantiate a member of another local class. */
16278 /* Closures are handled by the LAMBDA_EXPR. */
16288 }
16292 {
16293 tree condition;
16296 condition =
16298 args,
16307 }
16313 in_decl);
16350 {
16365 in_decl);
16367 {
16374 }
16386 integral_constant_expression_p);
16397 else
16398 {
16406 }
16410 }
16415 /* FALLTHRU */
16422 in_decl);
16439 in_decl);
16450 {
16453 {
16454 /* For combined target teams, ensure the num_teams and
16455 thread_limit clause expressions are evaluated on the host,
16456 before entering the target construct. */
16457 tree c;
16463 {
16472 OMP_CLAUSE_FIRSTPRIVATE);
16476 }
16477 }
16478 }
16538 {
16543 {
16546 }
16552 }
16553 else
16554 {
16561 {
16564 }
16567 {
16572 {
16575 }
16581 }
16582 else
16583 {
16587 }
16590 }
16594 {
16600 {
16604 {
16609 }
16613 }
16614 else
16615 {
16620 }
16621 }
16625 {
16629 }
16649 /* If the first operand was a statement, we're done with it. */
16653 complain));
16665 integral_constant_expression_p));
16666 }
16669 out:
16672 #undef RECUR
16673 #undef RETURN
16674 }
16676 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16677 function. For description of the body see comment above
16678 cp_parser_omp_declare_reduction_exprs. */
16680 static void
16682 {
16688 tree_stmt_iterator tsi;
16699 {
16718 }
16720 {
16740 }
16741 }
16743 /* T is a postfix-expression that is not being used in a function
16744 call. Return the substituted version of T. */
16746 static tree
16748 tsubst_flags_t complain,
16749 tree in_decl)
16750 {
16754 else
16760 }
16762 /* T is a LAMBDA_EXPR. Generate a new LAMBDA_EXPR for the current
16763 instantiation context. Instantiating a pack expansion containing a lambda
16764 might result in multiple lambdas all based on the same lambda in the
16765 template. */
16767 tree
16769 {
16783 else
16791 {
16803 else
16808 {
16817 }
16818 else
16819 {
16825 }
16826 }
16830 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
16848 else
16849 {
16850 /* Fix the type of 'this'. */
16856 {
16860 }
16861 else
16862 {
16866 }
16868 /* Let finish_function set this. */
16889 /* The capture list was built up in reverse order; fix that now. */
16896 }
16903 }
16905 /* Like tsubst but deals with expressions and performs semantic
16906 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16908 tree
16910 tree args,
16911 tsubst_flags_t complain,
16912 tree in_decl,
16915 {
16916 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16917 #define RECUR(NODE) \
16918 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16920 integral_constant_expression_p)
16923 location_t loc;
16932 /* N3276 decltype magic only applies to calls at the top level or on the
16933 right side of a comma. */
16938 {
16941 /* Fall through. */
16943 {
16944 tree decl;
16945 cp_id_kind idk;
16950 {
16953 }
16955 /* Look up the name. */
16958 /* By convention, expressions use ERROR_MARK_NODE to indicate
16959 failure, not NULL_TREE. */
16965 integral_constant_expression_p,
16973 input_location);
16977 {
16981 }
16983 }
16986 {
16987 tree object;
16997 {
17002 }
17008 {
17011 }
17012 else
17019 else
17021 }
17024 {
17028 {
17029 /* A type conversion to reference type will be enclosed in
17030 such an indirect ref, but the substitution of the cast
17031 will have also added such an indirect ref. */
17034 }
17035 else
17043 }
17046 {
17050 }
17053 {
17060 flags));
17061 }
17064 {
17068 }
17075 {
17076 tree type;
17082 {
17087 }
17093 {
17111 }
17114 }
17148 else
17150 in_decl);
17185 {
17192 tree r = build_x_binary_op
17194 op0,
17196 ? ERROR_MARK
17198 op1,
17200 ? ERROR_MARK
17208 }
17211 {
17215 }
17228 {
17237 }
17242 /* Fall through */
17245 {
17246 tree r;
17252 {
17253 /* When there are no ARGS, we are trying to evaluate a
17254 non-dependent expression from the parser. Trying to do
17255 the substitutions may not work. */
17258 }
17259 else
17260 {
17265 else
17268 /*integral_constant_expression_p=*/
17272 }
17276 else
17280 {
17282 {
17284 {
17288 }
17289 else
17293 }
17295 }
17297 }
17300 {
17310 }
17326 {
17330 tree r = build_x_modify_expr
17333 /* TREE_NO_WARNING must be set if either the expression was
17334 parenthesized or it uses an operator such as >>= rather
17335 than plain assignment. In the former case, it was already
17336 set and must be copied. In the latter case,
17337 build_x_modify_expr sets it and it must not be reset
17338 here. */
17343 }
17348 /* Remember that there was a reference to this entity. */
17355 {
17360 tree ret;
17364 else
17365 {
17369 }
17371 /* If there was an initializer in the original tree, but it
17372 instantiated to an empty list, then we should pass a
17373 non-NULL empty vector to tell build_new that it was an
17374 empty initializer() rather than no initializer. This can
17375 only happen when the initializer is a pack expansion whose
17376 parameter packs are of length zero. */
17379 else
17380 {
17384 else
17385 {
17388 }
17389 }
17395 complain);
17403 }
17406 {
17412 complain));
17413 }
17416 {
17420 integral_constant_expression_p);
17422 op0,
17425 }
17428 {
17429 tree function;
17434 tree ret;
17437 /* Internal function with no arguments. */
17441 /* When we parsed the expression, we determined whether or
17442 not Koenig lookup should be performed. */
17445 {
17448 }
17450 {
17455 }
17457 {
17458 /* Do nothing; calling tsubst_copy_and_build on an identifier
17459 would incorrectly perform unqualified lookup again.
17461 Note that we can also have an IDENTIFIER_NODE if the earlier
17462 unqualified lookup found a member function; in that case
17463 koenig_p will be false and we do want to do the lookup
17464 again to find the instantiated member function.
17466 FIXME but doing that causes c++/15272, so we need to stop
17467 using IDENTIFIER_NODE in that situation. */
17469 }
17470 else
17471 {
17473 {
17479 }
17480 else
17485 /* Avoid error about taking the address of a constructor. */
17489 in_decl,
17491 integral_constant_expression_p);
17495 }
17500 {
17505 else
17506 {
17507 /* Expand the pack expansion and push each entry onto
17508 CALL_ARGS. */
17511 {
17516 {
17521 }
17522 }
17523 else
17524 {
17525 /* A partial substitution. Add one entry. */
17527 }
17528 }
17529 }
17531 /* We do not perform argument-dependent lookup if normal
17532 lookup finds a non-function, in accordance with the
17533 expected resolution of DR 218. */
17536 /* If lookup found a member function, the Koenig lookup is
17537 not appropriate, even if an unqualified-name was used
17538 to denote the function. */
17541 /* Only do this when substitution turns a dependent call
17542 into a non-dependent call. */
17550 {
17552 {
17553 /* For backwards compatibility and good diagnostics, try
17554 the unqualified lookup again if we aren't in SFINAE
17555 context. */
17556 tree unq = (tsubst_copy_and_build
17558 integral_constant_expression_p));
17560 {
17563 }
17566 {
17567 /* In a lambda fn, we have to be careful to not
17568 introduce new this captures. Legacy code can't
17569 be using lambdas anyway, so it's ok to be
17570 stricter. */
17575 "and no declarations were found by "
17576 "argument-dependent lookup at the point "
17583 else
17587 {
17598 {
17600 input_location);
17602 "declarations in dependent base %qT are "
17608 else
17612 }
17613 else
17615 "%qD declared here, later in the "
17618 {
17621 }
17622 }
17625 }
17626 }
17628 {
17633 }
17634 }
17636 /* Remember that there was a reference to this entity. */
17640 {
17643 }
17645 /* Put back tf_decltype for the actual call. */
17650 {
17654 {
17656 "wrong number of arguments to "
17659 }
17660 else
17662 input_location),
17667 /* Unsupported internal function with arguments. */
17669 }
17672 complain);
17674 {
17689 complain);
17690 else
17691 ret = (build_new_method_call
17696 complain));
17697 }
17698 else
17701 koenig_p,
17702 complain);
17707 {
17713 {
17719 {
17721 /* The thunk location is not interesting. */
17723 }
17724 }
17725 }
17728 }
17731 {
17737 {
17739 {
17744 }
17745 else
17746 {
17751 }
17753 }
17754 else
17755 {
17758 }
17762 }
17765 {
17770 input_location));
17771 }
17774 {
17782 {
17783 /* We have pack expansions, so expand those and
17784 create a new list out of it. */
17787 tree chain;
17790 /* Expand the argument expressions. */
17798 /* Build the rest of the list. */
17803 /* Determine the number of arguments. */
17805 {
17808 }
17811 else
17812 {
17813 /* Since we only performed a partial substitution into
17814 the argument pack, we only RETURN (a single list
17815 node. */
17822 }
17824 /* Convert the argument vectors into a TREE_LIST */
17827 {
17828 /* Grab the Ith values. */
17829 i--;
17832 value
17836 /* Build the list (backwards). */
17838 }
17841 }
17857 }
17860 {
17861 tree object;
17862 tree object_type;
17863 tree member;
17864 tree r;
17868 /* Remember that there was a reference to this entity. */
17879 else
17885 {
17890 }
17894 {
17896 {
17901 {
17904 }
17906 {
17911 }
17912 }
17913 }
17916 {
17917 /* Lookup the template functions now that we know what the
17918 scope is. */
17926 {
17929 args);
17930 member = (adjust_result_of_qualified_name_lookup
17932 object_type));
17933 }
17934 else
17935 {
17937 input_location);
17939 }
17940 }
17944 {
17946 {
17950 else
17953 }
17955 }
17959 complain);
17963 }
17970 {
17978 tree r;
17983 /* digest_init will do the wrong thing if we let it. */
17987 /* We do not want to process the index of aggregate
17988 initializers as they are identifier nodes which will be
17989 looked up by digest_init. */
17995 {
17997 /* An identifier index is looked up in the type
17998 being initialized, not the current scope. */
18003 {
18004 /* Substitute into the pack expansion. */
18006 in_decl);
18010 ;
18012 /* Just move the argument into place. */
18014 else
18015 {
18016 /* Update the length of the final CONSTRUCTOR
18017 arguments vector, and note that we will need to
18018 copy.*/
18021 }
18022 }
18023 else
18025 }
18028 {
18033 {
18035 {
18040 }
18041 else
18043 }
18044 }
18050 {
18055 }
18059 }
18062 {
18065 {
18068 }
18069 else
18070 {
18073 }
18074 }
18080 {
18081 /* We don't build decls for an instantiation of a
18082 variadic capture proxy, we instantiate the elements
18083 when needed. */
18086 }
18087 /* Fall through */
18090 {
18092 /* ??? We're doing a subset of finish_id_expression here. */
18094 && !processing_template_decl
18095 && !cp_unevaluated_operand
18098 {
18100 /* Replace an evaluated use of the thread_local variable with
18101 a call to its wrapper. */
18103 }
18105 {
18109 }
18112 /* If the original type was a reference, we'll be wrapped in
18113 the appropriate INDIRECT_REF. */
18116 }
18119 {
18123 }
18126 {
18127 tree object_ptr
18134 }
18141 {
18152 }
18155 {
18161 integral_constant_expression_p);
18165 /* If the resulting list of expression statement is empty,
18166 fold it further into void_node. */
18171 }
18174 {
18178 }
18181 /* We can get here for a constant initializer of non-dependent type.
18182 FIXME stop folding in cp_parser_initializer_clause. */
18183 {
18185 complain);
18187 }
18191 integral_constant_expression_p));
18197 {
18202 complain));
18203 }
18209 /* Handle Objective-C++ constructs, if appropriate. */
18210 {
18211 tree subst
18216 }
18218 }
18220 #undef RECUR
18221 #undef RETURN
18222 out:
18225 }
18227 /* Verify that the instantiated ARGS are valid. For type arguments,
18228 make sure that the type's linkage is ok. For non-type arguments,
18229 make sure they are constants if they are integral or enumerations.
18230 Emit an error under control of COMPLAIN, and return TRUE on error. */
18232 static bool
18234 {
18238 {
18248 }
18250 {
18251 /* [basic.link]: A name with no linkage (notably, the name
18252 of a class or enumeration declared in a local scope)
18253 shall not be used to declare an entity with linkage.
18254 This implies that names with no linkage cannot be used as
18255 template arguments
18257 DR 757 relaxes this restriction for C++0x. */
18262 {
18263 /* DR 488 makes use of a type with no linkage cause
18264 type deduction to fail. */
18266 {
18269 else
18272 }
18274 }
18275 /* In order to avoid all sorts of complications, we do not
18276 allow variably-modified types as template arguments. */
18278 {
18282 }
18283 }
18284 /* Class template and alias template arguments should be OK. */
18286 ;
18287 /* A non-type argument of integral or enumerated type must be a
18288 constant. */
18293 {
18297 }
18299 }
18301 static bool
18303 {
18308 {
18311 }
18315 }
18317 /* We're out of SFINAE context now, so generate diagnostics for the access
18318 errors we saw earlier when instantiating D from TMPL and ARGS. */
18320 static void
18322 {
18334 }
18336 /* Instantiate the indicated variable, function, or alias template TMPL with
18337 the template arguments in TARG_PTR. */
18339 static tree
18341 {
18343 tree fndecl;
18344 tree gen_tmpl;
18345 tree spec;
18353 /* If this function is a clone, handle it specially. */
18355 {
18356 tree spec;
18357 tree clone;
18359 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18360 DECL_CLONED_FUNCTION. */
18366 /* Look for the clone. */
18370 /* We should always have found the clone by now. */
18373 }
18378 /* Check to see if we already have this specialization. */
18382 /* targ_ptr only has the innermost template args, so add the outer ones
18383 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18384 the case of a non-dependent call within a template definition). */
18385 targ_ptr = (add_outermost_template_args
18387 targ_ptr));
18389 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18390 but it doesn't seem to be on the hot path. */
18399 {
18401 {
18405 }
18407 }
18410 complain))
18413 /* We are building a FUNCTION_DECL, during which the access of its
18414 parameters and return types have to be checked. However this
18415 FUNCTION_DECL which is the desired context for access checking
18416 is not built yet. We solve this chicken-and-egg problem by
18417 deferring all checks until we have the FUNCTION_DECL. */
18420 /* Instantiation of the function happens in the context of the function
18421 template, not the context of the overload resolution we're doing. */
18423 /* If there are dependent arguments, e.g. because we're doing partial
18424 ordering, make sure processing_template_decl stays set. */
18428 {
18432 }
18438 {
18439 /* We need to determine if we're using a partial or explicit
18440 specialization now, because the type of the variable could be
18441 different. */
18447 {
18452 }
18453 }
18455 /* Substitute template parameters to obtain the specialization. */
18463 {
18466 }
18468 /* The DECL_TI_TEMPLATE should always be the immediate parent
18469 template, not the most general template. */
18473 /* Now we know the specialization, compute access previously
18474 deferred. Do no access control for inheriting constructors,
18475 as we already checked access for the inherited constructor. */
18478 {
18483 }
18486 /* If we've just instantiated the main entry point for a function,
18487 instantiate all the alternate entry points as well. We do this
18488 by cloning the instantiation of the main entry point, not by
18489 instantiating the template clones. */
18494 {
18496 {
18497 /* Remember to reinstantiate when we're out of SFINAE so the user
18498 can see the errors. */
18500 }
18502 }
18504 }
18506 /* Wrapper for instantiate_template_1. */
18508 tree
18510 {
18511 tree ret;
18516 }
18518 /* Instantiate the alias template TMPL with ARGS. Also push a template
18519 instantiation level, which instantiate_template doesn't do because
18520 functions and variables have sufficient context established by the
18521 callers. */
18523 static tree
18525 {
18532 {
18535 }
18537 args =
18545 /* We can't free this if a pending_template entry or last_error_tinst_level
18546 is pointing at it. */
18552 }
18554 /* PARM is a template parameter pack for FN. Returns true iff
18555 PARM is used in a deducible way in the argument list of FN. */
18557 static bool
18559 {
18562 {
18564 tree packs;
18570 {
18571 /* The template parameter pack is used in a function parameter
18572 pack. If this is the end of the parameter list, the
18573 template parameter pack is deducible. */
18576 else
18577 /* Otherwise, not. Well, it could be deduced from
18578 a non-pack parameter, but doing so would end up with
18579 a deduction mismatch, so don't bother. */
18581 }
18582 }
18583 /* The template parameter pack isn't used in any function parameter
18584 packs, but it might be used deeper, e.g. tuple<Args...>. */
18586 }
18588 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18589 NARGS elements of the arguments that are being used when calling
18590 it. TARGS is a vector into which the deduced template arguments
18591 are placed.
18593 Returns either a FUNCTION_DECL for the matching specialization of FN or
18594 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18595 true, diagnostics will be printed to explain why it failed.
18597 If FN is a conversion operator, or we are trying to produce a specific
18598 specialization, RETURN_TYPE is the return type desired.
18600 The EXPLICIT_TARGS are explicit template arguments provided via a
18601 template-id.
18603 The parameter STRICT is one of:
18605 DEDUCE_CALL:
18606 We are deducing arguments for a function call, as in
18607 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18608 deducing arguments for a call to the result of a conversion
18609 function template, as in [over.call.object].
18611 DEDUCE_CONV:
18612 We are deducing arguments for a conversion function, as in
18613 [temp.deduct.conv].
18615 DEDUCE_EXACT:
18616 We are deducing arguments when doing an explicit instantiation
18617 as in [temp.explicit], when determining an explicit specialization
18618 as in [temp.expl.spec], or when taking the address of a function
18619 template, as in [temp.deduct.funcaddr]. */
18621 tree
18623 tree explicit_targs,
18624 tree targs,
18627 tree return_type,
18628 unification_kind_t strict,
18632 {
18633 tree parms;
18634 tree fntype;
18647 tree tinst;
18653 full_targs = (add_outermost_template_args
18655 targs));
18660 /* In C++0x, it's possible to have a function template whose type depends
18661 on itself recursively. This is most obvious with decltype, but can also
18662 occur with enumeration scope (c++/48969). So we need to catch infinite
18663 recursion and reject the substitution at deduction time; this function
18664 will return error_mark_node for any repeated substitution.
18666 This also catches excessive recursion such as when f<N> depends on
18667 f<N-1> across all integers, and returns error_mark_node for all the
18668 substitutions back up to the initial one.
18670 This is, of course, not reentrant. */
18680 {
18681 /* [temp.deduct]
18683 The specified template arguments must match the template
18684 parameters in kind (i.e., type, nontype, template), and there
18685 must not be more arguments than there are parameters;
18686 otherwise type deduction fails.
18688 Nontype arguments must match the types of the corresponding
18689 nontype template parameters, or must be convertible to the
18690 types of the corresponding nontype parameters as specified in
18691 _temp.arg.nontype_, otherwise type deduction fails.
18693 All references in the function type of the function template
18694 to the corresponding template parameters are replaced by the
18695 specified template argument values. If a substitution in a
18696 template parameter or in the function type of the function
18697 template results in an invalid type, type deduction fails. */
18708 explicit_targs);
18710 /* Adjust any explicit template arguments before entering the
18711 substitution context. */
18712 explicit_targs
18714 complain,
18720 /* Substitute the explicit args into the function type. This is
18721 necessary so that, for instance, explicitly declared function
18722 arguments can match null pointed constants. If we were given
18723 an incomplete set of explicit args, we must not do semantic
18724 processing during substitution as we could create partial
18725 instantiations. */
18727 {
18732 /* Dig out the actual parm. */
18735 {
18738 }
18740 {
18743 }
18746 /* No explicit argument for this template parameter. */
18750 {
18751 /* Mark the argument pack as "incomplete". We could
18752 still deduce more arguments during unification.
18753 We remove this mark in type_unification_real. */
18755 {
18759 }
18761 /* We have some incomplete argument packs. */
18763 }
18764 }
18768 {
18771 }
18774 /* Ignore any access checks; we'll see them again in
18775 instantiate_template and they might have the wrong
18776 access path at this point. */
18788 /* Place the explicitly specified arguments in TARGS. */
18792 }
18794 /* Never do unification on the 'this' parameter. */
18798 {
18799 /* We're deducing for a call to the result of a template conversion
18800 function. The parms we really want are in return_type. */
18804 }
18806 {
18815 }
18817 /* We allow incomplete unification without an error message here
18818 because the standard doesn't seem to explicitly prohibit it. Our
18819 callers must be ready to deal with unification failures in any
18820 event. */
18823 /* If we aren't explaining yet, push tinst context so we can see where
18824 any errors (e.g. from class instantiations triggered by instantiation
18825 of default template arguments) come from. If we are explaining, this
18826 context is redundant. */
18828 {
18831 }
18833 /* type_unification_real will pass back any access checks from default
18834 template argument substitution. */
18846 /* Now that we have bindings for all of the template arguments,
18847 ensure that the arguments deduced for the template template
18848 parameters have compatible template parameter lists. We cannot
18849 check this property before we have deduced all template
18850 arguments, because the template parameter types of a template
18851 template parameter might depend on prior template parameters
18852 deduced after the template template parameter. The following
18853 ill-formed example illustrates this issue:
18855 template<typename T, template<T> class C> void f(C<5>, T);
18857 template<int N> struct X {};
18859 void g() {
18860 f(X<5>(), 5l); // error: template argument deduction fails
18861 }
18863 The template parameter list of 'C' depends on the template type
18864 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18865 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18866 time that we deduce 'C'. */
18869 {
18872 }
18874 /* All is well so far. Now, check:
18876 [temp.deduct]
18878 When all template arguments have been deduced, all uses of
18879 template parameters in nondeduced contexts are replaced with
18880 the corresponding deduced argument values. If the
18881 substitution results in an invalid type, as described above,
18882 type deduction fails. */
18885 {
18888 }
18890 /* Also collect access checks from the instantiation. */
18903 /* Now perform any access checks encountered during substitution. */
18910 /* If we're looking for an exact match, check that what we got
18911 is indeed an exact match. It might not be if some template
18912 parameters are used in non-deduced contexts. But don't check
18913 for an exact match if we have dependent template arguments;
18914 in that case we're doing partial ordering, and we already know
18915 that we have two candidates that will provide the actual type. */
18917 {
18921 tree sarg
18927 {
18931 }
18932 }
18934 /* After doing deduction with the inherited constructor, actually return an
18935 instantiation of the inheriting constructor. */
18941 fail:
18944 {
18946 /* Reset once we're all the way out. */
18948 }
18950 /* We can't free this if a pending_template entry or last_error_tinst_level
18951 is pointing at it. */
18957 }
18959 /* Adjust types before performing type deduction, as described in
18960 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18961 sections are symmetric. PARM is the type of a function parameter
18962 or the return type of the conversion function. ARG is the type of
18963 the argument passed to the call, or the type of the value
18964 initialized with the result of the conversion function.
18965 ARG_EXPR is the original argument expression, which may be null. */
18967 static int
18971 tree arg_expr)
18972 {
18976 {
18981 /* Swap PARM and ARG throughout the remainder of this
18982 function; the handling is precisely symmetric since PARM
18983 will initialize ARG rather than vice versa. */
18988 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18989 too, but here handle it by stripping the reference from PARM
18990 rather than by adding it to ARG. */
18998 /* Nothing else to do in this case. */
19003 }
19006 {
19007 /* [temp.deduct.call]
19009 If P is not a reference type:
19011 --If A is an array type, the pointer type produced by the
19012 array-to-pointer standard conversion (_conv.array_) is
19013 used in place of A for type deduction; otherwise,
19015 --If A is a function type, the pointer type produced by
19016 the function-to-pointer standard conversion
19017 (_conv.func_) is used in place of A for type deduction;
19018 otherwise,
19020 --If A is a cv-qualified type, the top level
19021 cv-qualifiers of A's type are ignored for type
19022 deduction. */
19027 else
19029 }
19031 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
19032 reference to a cv-unqualified template parameter that does not represent a
19033 template parameter of a class template (during class template argument
19034 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
19035 an lvalue, the type "lvalue reference to A" is used in place of A for type
19036 deduction. */
19043 /* try_one_overload doesn't provide an arg_expr, but
19044 functions are always lvalues. */
19048 /* [temp.deduct.call]
19050 If P is a cv-qualified type, the top level cv-qualifiers
19051 of P's type are ignored for type deduction. If P is a
19052 reference type, the type referred to by P is used for
19053 type deduction. */
19056 {
19059 }
19061 /* DR 322. For conversion deduction, remove a reference type on parm
19062 too (which has been swapped into ARG). */
19067 }
19069 /* Subroutine of unify_one_argument. PARM is a function parameter of a
19070 template which does contain any deducible template parameters; check if
19071 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
19072 unify_one_argument. */
19074 static int
19077 {
19078 tree type;
19082 else
19089 {
19093 }
19095 {
19100 }
19104 else
19106 }
19110 /* Returns true iff the expression EXPR is one from which a template
19111 argument can be deduced. In other words, if it's an undecorated
19112 use of a template non-type parameter. */
19114 static bool
19116 {
19117 /* Strip implicit conversions. */
19121 }
19123 /* Returns true iff the array domain DOMAIN uses a template parameter in a
19124 deducible way; that is, if it has a max value of <PARM> - 1. */
19126 static bool
19128 {
19137 }
19139 /* Returns true iff the template arguments ARGS use a template parameter
19140 in a deducible way. */
19142 static bool
19144 {
19146 {
19151 else
19152 {
19159 else
19161 }
19164 }
19166 }
19168 /* Returns true iff TYPE contains any deducible references to template
19169 parameters, as per 14.8.2.5. */
19171 static bool
19173 {
19177 /* T
19178 cv-list T
19179 TT<T>
19180 TT<i>
19181 TT<> */
19186 /* T*
19187 T&
19188 T&& */
19192 /* T[integer-constant ]
19193 type [i] */
19198 /* T type ::*
19199 type T::*
19200 T T::*
19201 T (type ::*)()
19202 type (T::*)()
19203 type (type ::*)(T)
19204 type (T::*)(T)
19205 T (type ::*)(T)
19206 T (T::*)()
19207 T (T::*)(T) */
19210 || (uses_deducible_template_parms
19213 /* template-name <T> (where template-name refers to a class template)
19214 template-name <i> (where template-name refers to a class template) */
19221 /* type (T)
19222 T()
19223 T(T) */
19226 {
19235 }
19238 }
19240 /* Subroutine of type_unification_real and unify_pack_expansion to
19241 handle unification of a single P/A pair. Parameters are as
19242 for those functions. */
19244 static int
19248 {
19255 /* We can't deduce anything from this, but we might get all the
19256 template args from other function args. */
19259 /* Implicit conversions (Clause 4) will be performed on a function
19260 argument to convert it to the type of the corresponding function
19261 parameter if the parameter type contains no template-parameters that
19262 participate in template argument deduction. */
19265 /* For function parameters with no deducible template parameters,
19266 just return. We'll check non-dependent conversions later. */
19270 {
19272 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19273 | UNIFY_ALLOW_MORE_CV_QUAL
19287 }
19289 /* We only do these transformations if this is the top-level
19290 parameter_type_list in a call or declaration matching; in other
19291 situations (nested function declarators, template argument lists) we
19292 won't be comparing a type to an expression, and we don't do any type
19293 adjustments. */
19295 {
19297 {
19300 {
19301 /* [temp.deduct.type] A template-argument can be
19302 deduced from a pointer to function or pointer
19303 to member function argument if the set of
19304 overloaded functions does not contain function
19305 templates and at most one of a set of
19306 overloaded functions provides a unique
19307 match. */
19314 }
19320 }
19322 arg_strict |=
19324 }
19325 else
19330 /* For deduction from an init-list we need the actual list. */
19334 }
19336 /* for_each_template_parm callback that always returns 0. */
19338 static int
19340 {
19342 }
19344 /* for_each_template_parm any_fn callback to handle deduction of a template
19345 type argument from the type of an array bound. */
19347 static int
19349 {
19357 {
19363 }
19365 /* Keep walking. */
19367 }
19369 /* Try to deduce any not-yet-deduced template type arguments from the type of
19370 an array bound. This is handled separately from unify because 14.8.2.5 says
19371 "The type of a type parameter is only deduced from an array bound if it is
19372 not otherwise deduced." */
19374 static void
19376 {
19381 }
19383 /* Most parms like fn_type_unification.
19385 If SUBR is 1, we're being called recursively (to unify the
19386 arguments of a function or method parameter of a function
19387 template).
19389 CHECKS is a pointer to a vector of access checks encountered while
19390 substituting default template arguments. */
19392 static int
19394 tree full_targs,
19395 tree xparms,
19399 unification_kind_t strict,
19403 {
19408 tree parms;
19419 /* Reset the number of non-defaulted template arguments contained
19420 in TARGS. */
19423 again:
19431 {
19436 /* For a function parameter pack that occurs at the end of the
19437 parameter-declaration-list, the type A of each remaining
19438 argument of the call is compared with the type P of the
19439 declarator-id of the function parameter pack. */
19445 /* For a function parameter pack that does not occur at the
19446 end of the parameter-declaration-list, the type of the
19447 parameter pack is a non-deduced context. */
19454 explain_p))
19456 }
19461 {
19462 /* Unify the remaining arguments with the pack expansion type. */
19463 tree argvec;
19466 /* Allocate a TREE_VEC and copy in all of the arguments */
19471 /* Copy the parameter into parmvec. */
19477 /* Advance to the end of the list of parameters. */
19479 }
19481 /* Fail if we've reached the end of the parm list, and more args
19482 are present, and the parm list isn't variadic. */
19485 /* Fail if parms are left and they don't have default values and
19486 they aren't all deduced as empty packs (c++/57397). This is
19487 consistent with sufficient_parms_p. */
19490 {
19494 do
19495 {
19498 count++;
19500 }
19504 type_pack_p);
19505 }
19508 {
19509 tsubst_flags_t complain = (explain_p
19510 ? tf_warning_or_error
19515 {
19519 /* Clear the "incomplete" flags on all argument packs now so that
19520 substituting them into later default arguments works. */
19522 {
19525 }
19533 {
19538 }
19540 /* If this is an undeduced nontype parameter that depends on
19541 a type parameter, try another pass; its type may have been
19542 deduced from a later argument than the one from which
19543 this parameter can be deduced. */
19547 {
19550 }
19552 /* Core issue #226 (C++0x) [temp.deduct]:
19554 If a template argument has not been deduced, its
19555 default template argument, if any, is used.
19557 When we are in C++98 mode, TREE_PURPOSE will either
19558 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19559 to explicitly check cxx_dialect here. */
19561 /* OK, there is a default argument. Wait until after the
19562 conversion check to do substitution. */
19565 /* If the type parameter is a parameter pack, then it will
19566 be deduced to an empty parameter pack. */
19568 {
19569 tree arg;
19572 {
19575 }
19576 else
19583 }
19586 }
19588 /* DR 1391: All parameters have args, now check non-dependent parms for
19589 convertibility. */
19593 {
19599 /* For a function parameter pack that occurs at the end of the
19600 parameter-declaration-list, the type A of each remaining
19601 argument of the call is compared with the type P of the
19602 declarator-id of the function parameter pack. */
19608 /* For a function parameter pack that does not occur at the
19609 end of the parameter-declaration-list, the type of the
19610 parameter pack is a non-deduced context. */
19619 explain_p))
19621 }
19623 /* Now substitute into the default template arguments. */
19625 {
19649 else
19657 {
19659 /* The position of the first default template argument,
19660 is also the number of non-defaulted arguments in TARGS.
19661 Record that. */
19664 }
19665 }
19669 }
19675 }
19677 /* Subroutine of type_unification_real. Args are like the variables
19678 at the call site. ARG is an overloaded function (or template-id);
19679 we try deducing template args from each of the overloads, and if
19680 only one succeeds, we go with that. Modifies TARGS and returns
19681 true on success. */
19683 static bool
19685 tree targs,
19686 tree parm,
19687 tree arg,
19688 unification_kind_t strict,
19691 {
19698 {
19701 }
19702 else
19706 /* Handle `&x' where `x' is some static or non-static member
19707 function name. */
19713 /* Strip baselink information. */
19718 {
19719 /* If we got some explicit template args, we need to plug them into
19720 the affected templates before we try to unify, in case the
19721 explicit args will completely resolve the templates in question. */
19728 {
19741 {
19746 {
19749 }
19750 }
19753 }
19754 /* If no templates (or more than one) are fully resolved by the
19755 explicit arguments, this template-id is a non-deduced context; it
19756 could still be OK if we deduce all template arguments for the
19757 enclosing call through other arguments. */
19760 }
19763 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19764 -- but the deduction does not succeed because the expression is
19765 not just the function on its own. */
19767 else
19769 {
19774 {
19777 }
19778 }
19780 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19781 to function or pointer to member function argument if the set of
19782 overloaded functions does not contain function templates and at most
19783 one of a set of overloaded functions provides a unique match.
19785 So if we found multiple possibilities, we return success but don't
19786 deduce anything. */
19789 {
19793 {
19798 /* Don't forget explicit template arguments in a pack. */
19802 }
19803 }
19808 }
19810 /* Core DR 115: In contexts where deduction is done and fails, or in
19811 contexts where deduction is not done, if a template argument list is
19812 specified and it, along with any default template arguments, identifies
19813 a single function template specialization, then the template-id is an
19814 lvalue for the function template specialization. */
19816 tree
19818 {
19831 {
19834 }
19836 {
19839 }
19841 {
19844 }
19847 {
19851 /* If we got some explicit template args, we need to plug them into
19852 the affected templates before we try to unify, in case the
19853 explicit args will completely resolve the templates in question. */
19861 {
19874 {
19877 {
19880 }
19882 {
19885 }
19886 }
19887 }
19889 {
19897 {
19898 tree base
19901 }
19905 }
19907 /* There were no good options and at least one bad one, so let the
19908 user know what the problem is. */
19910 }
19912 }
19914 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19915 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19916 different overloads deduce different arguments for a given parm.
19917 ADDR_P is true if the expression for which deduction is being
19918 performed was of the form "& fn" rather than simply "fn".
19920 Returns 1 on success. */
19922 static int
19924 tree orig_targs,
19925 tree targs,
19926 tree parm,
19927 tree arg,
19928 unification_kind_t strict,
19932 {
19934 tree tempargs;
19940 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19941 to function or pointer to member function argument if the set of
19942 overloaded functions does not contain function templates and at most
19943 one of a set of overloaded functions provides a unique match.
19945 So if this is a template, just return success. */
19957 /* We don't copy orig_targs for this because if we have already deduced
19958 some template args from previous args, unify would complain when we
19959 try to deduce a template parameter for the same argument, even though
19960 there isn't really a conflict. */
19967 /* First make sure we didn't deduce anything that conflicts with
19968 explicitly specified args. */
19970 {
19977 /* Since we're unifying against ourselves, we will fill in
19978 template args used in the function parm list with our own
19979 template parms. Discard them. */
19982 {
19983 /* Check that the argument at each index of the deduced argument pack
19984 is equivalent to the corresponding explicitly specified argument.
19985 We may have deduced more arguments than were explicitly specified,
19986 and that's OK. */
19988 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19989 that's wrong if we deduce the same argument pack from multiple
19990 function arguments: it's only incomplete the first time. */
20003 }
20006 }
20009 {
20014 }
20017 }
20019 /* PARM is a template class (perhaps with unbound template
20020 parameters). ARG is a fully instantiated type. If ARG can be
20021 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
20022 TARGS are as for unify. */
20024 static tree
20027 {
20028 tree copy_of_targs;
20038 /* We need to make a new template argument vector for the call to
20039 unify. If we used TARGS, we'd clutter it up with the result of
20040 the attempted unification, even if this class didn't work out.
20041 We also don't want to commit ourselves to all the unifications
20042 we've already done, since unification is supposed to be done on
20043 an argument-by-argument basis. In other words, consider the
20044 following pathological case:
20046 template <int I, int J, int K>
20047 struct S {};
20049 template <int I, int J>
20050 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
20052 template <int I, int J, int K>
20053 void f(S<I, J, K>, S<I, I, I>);
20055 void g() {
20056 S<0, 0, 0> s0;
20057 S<0, 1, 2> s2;
20059 f(s0, s2);
20060 }
20062 Now, by the time we consider the unification involving `s2', we
20063 already know that we must have `f<0, 0, 0>'. But, even though
20064 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
20065 because there are two ways to unify base classes of S<0, 1, 2>
20066 with S<I, I, I>. If we kept the already deduced knowledge, we
20067 would reject the possibility I=1. */
20071 {
20075 }
20077 /* If unification failed, we're done. */
20083 }
20085 /* Given a template type PARM and a class type ARG, find the unique
20086 base type in ARG that is an instance of PARM. We do not examine
20087 ARG itself; only its base-classes. If there is not exactly one
20088 appropriate base class, return NULL_TREE. PARM may be the type of
20089 a partial specialization, as well as a plain template type. Used
20090 by unify. */
20092 static enum template_base_result
20095 {
20097 tree binfo;
20103 {
20104 /* The type could not be completed. */
20107 }
20109 /* Walk in inheritance graph order. The search order is not
20110 important, and this avoids multiple walks of virtual bases. */
20112 {
20117 {
20118 /* If there is more than one satisfactory baseclass, then:
20120 [temp.deduct.call]
20122 If they yield more than one possible deduced A, the type
20123 deduction fails.
20125 applies. */
20127 {
20130 }
20133 }
20134 }
20138 }
20140 /* Returns the level of DECL, which declares a template parameter. */
20142 static int
20144 {
20146 {
20156 }
20158 }
20160 /* Decide whether ARG can be unified with PARM, considering only the
20161 cv-qualifiers of each type, given STRICT as documented for unify.
20162 Returns nonzero iff the unification is OK on that basis. */
20164 static int
20166 {
20172 {
20173 /* Although a CVR qualifier is ignored when being applied to a
20174 substituted template parameter ([8.3.2]/1 for example), that
20175 does not allow us to unify "const T" with "int&" because both
20176 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
20177 It is ok when we're allowing additional CV qualifiers
20178 at the outer level [14.8.2.1]/3,1st bullet. */
20188 }
20199 }
20201 /* Determines the LEVEL and INDEX for the template parameter PARM. */
20202 void
20204 {
20208 {
20211 }
20212 else
20213 {
20216 }
20217 }
20219 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
20220 do { \
20221 if (unify (TP, TA, P, A, S, EP)) \
20222 return 1; \
20223 } while (0)
20225 /* Unifies the remaining arguments in PACKED_ARGS with the pack
20226 expansion at the end of PACKED_PARMS. Returns 0 if the type
20227 deduction succeeds, 1 otherwise. STRICT is the same as in
20228 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
20229 function call argument list. We'll need to adjust the arguments to make them
20230 types. SUBR tells us if this is from a recursive call to
20231 type_unification_real, or for comparing two template argument
20232 lists. */
20234 static int
20238 {
20239 tree parm
20245 /* Add in any args remembered from an earlier partial instantiation. */
20252 /* Determine the parameter packs we will be deducing from the
20253 pattern, and record their current deductions. */
20256 {
20260 /* Determine the index and level of this parameter pack. */
20263 /* Keep track of the parameter packs and their corresponding
20264 argument packs. */
20267 }
20269 /* Loop through all of the arguments that have not yet been
20270 unified and unify each with the pattern. */
20272 {
20273 tree parm;
20277 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20278 or the element of its argument pack at the current index if
20279 this argument was explicitly specified. */
20281 {
20290 {
20293 }
20295 }
20297 /* If we had explicit template arguments, substitute them into the
20298 pattern before deduction. */
20300 {
20301 /* Some arguments might still be unspecified or dependent. */
20309 NULL_TREE);
20314 }
20315 else
20318 /* Unify the pattern with the current argument. */
20320 explain_p))
20323 /* For each parameter pack, collect the deduced value. */
20325 {
20331 }
20332 }
20334 /* Verify that the results of unification with the parameter packs
20335 produce results consistent with what we've seen before, and make
20336 the deduced argument packs available. */
20338 {
20345 /* By default keep the original deduced argument pack.
20346 If necessary, more specific code is going to update the
20347 resulting deduced argument later down in this function. */
20351 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20352 actually deduce anything. */
20360 {
20361 /* If we had fewer function args than explicit template args,
20362 just use the explicits. */
20367 }
20370 {
20371 tree result;
20372 /* Build the deduced *_ARGUMENT_PACK. */
20374 {
20377 }
20378 else
20383 /* Note the deduced argument packs for this parameter
20384 pack. */
20386 }
20390 {
20391 /* We only had the explicitly-provided arguments before, but
20392 now we have a complete set of arguments. */
20398 }
20399 else
20400 {
20406 /* Inconsistent unification of this parameter pack. */
20408 bad_old_arg,
20409 bad_new_arg);
20410 }
20411 }
20414 }
20416 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20417 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20418 parameters and return value are as for unify. */
20420 static int
20424 {
20425 tree parm_max;
20426 tree arg_max;
20430 /* Our representation of array types uses "N - 1" as the
20431 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20432 not an integer constant. We cannot unify arbitrarily
20433 complex expressions, so we eliminate the MINUS_EXPRs
20434 here. */
20438 {
20441 }
20445 {
20446 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20447 trying to unify the type of a variable with the type
20448 of a template parameter. For example:
20450 template <unsigned int N>
20451 void f (char (&) [N]);
20452 int g();
20453 void h(int i) {
20454 char a[g(i)];
20455 f(a);
20456 }
20458 Here, the type of the ARG will be "int [g(i)]", and
20459 may be a SAVE_EXPR, etc. */
20463 }
20465 /* If only one of the bounds used a MINUS_EXPR, compensate
20466 by adding one to the other bound. */
20469 integer_type_node,
20470 parm_max,
20471 integer_one_node);
20474 integer_type_node,
20475 arg_max,
20476 integer_one_node);
20480 }
20482 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20486 static pa_kind_t
20488 {
20497 else
20499 }
20501 /* Deduce the value of template parameters. TPARMS is the (innermost)
20502 set of template parameters to a template. TARGS is the bindings
20503 for those template parameters, as determined thus far; TARGS may
20504 include template arguments for outer levels of template parameters
20505 as well. PARM is a parameter to a template function, or a
20506 subcomponent of that parameter; ARG is the corresponding argument.
20507 This function attempts to match PARM with ARG in a manner
20508 consistent with the existing assignments in TARGS. If more values
20509 are deduced, then TARGS is updated.
20511 Returns 0 if the type deduction succeeds, 1 otherwise. The
20512 parameter STRICT is a bitwise or of the following flags:
20514 UNIFY_ALLOW_NONE:
20515 Require an exact match between PARM and ARG.
20516 UNIFY_ALLOW_MORE_CV_QUAL:
20517 Allow the deduced ARG to be more cv-qualified (by qualification
20518 conversion) than ARG.
20519 UNIFY_ALLOW_LESS_CV_QUAL:
20520 Allow the deduced ARG to be less cv-qualified than ARG.
20521 UNIFY_ALLOW_DERIVED:
20522 Allow the deduced ARG to be a template base class of ARG,
20523 or a pointer to a template base class of the type pointed to by
20524 ARG.
20525 UNIFY_ALLOW_INTEGER:
20526 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20527 case for more information.
20528 UNIFY_ALLOW_OUTER_LEVEL:
20529 This is the outermost level of a deduction. Used to determine validity
20530 of qualification conversions. A valid qualification conversion must
20531 have const qualified pointers leading up to the inner type which
20532 requires additional CV quals, except at the outer level, where const
20533 is not required [conv.qual]. It would be normal to set this flag in
20534 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20535 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20536 This is the outermost level of a deduction, and PARM can be more CV
20537 qualified at this point.
20538 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20539 This is the outermost level of a deduction, and PARM can be less CV
20540 qualified at this point. */
20542 static int
20545 {
20547 tree targ;
20548 tree tparm;
20550 tsubst_flags_t complain = (explain_p
20551 ? tf_warning_or_error
20554 /* I don't think this will do the right thing with respect to types.
20555 But the only case I've seen it in so far has been array bounds, where
20556 signedness is the only information lost, and I think that will be
20557 okay. */
20565 /* We can't deduce anything from this, but we might get all the
20566 template args from other function args. */
20572 /* If PARM uses template parameters, then we can't bail out here,
20573 even if ARG == PARM, since we won't record unifications for the
20574 template parameters. We might need them if we're trying to
20575 figure out which of two things is more specialized. */
20579 /* Handle init lists early, so the rest of the function can assume
20580 we're dealing with a type. */
20582 {
20587 /* Replace T with std::initializer_list<T> for deduction. */
20594 /* We can only deduce from an initializer list argument if the
20595 parameter is std::initializer_list or an array; otherwise this
20596 is a non-deduced context. */
20601 else
20602 {
20604 /* Deduction is defined in terms of a single type, so just punt
20605 on the (bizarre) std::initializer_list<T...>. */
20608 }
20611 {
20618 {
20622 /* It should only be possible to get here for a call. */
20624 elt_strict |= maybe_adjust_types_for_deduction
20627 }
20630 explain_p);
20631 }
20635 {
20636 /* Also deduce from the length of the initializer list. */
20643 }
20645 /* If the std::initializer_list<T> deduction worked, replace the
20646 deduced A with std::initializer_list<A>. */
20648 {
20653 }
20655 }
20657 /* If parm and arg aren't the same kind of thing (template, type, or
20658 expression), fail early. */
20662 /* Immediately reject some pairs that won't unify because of
20663 cv-qualification mismatches. */
20666 /* It is the elements of the array which hold the cv quals of an array
20667 type, and the elements might be template type parms. We'll check
20668 when we recurse. */
20670 /* We check the cv-qualifiers when unifying with template type
20671 parameters below. We want to allow ARG `const T' to unify with
20672 PARM `T' for example, when computing which of two templates
20673 is more specialized, for example. */
20687 {
20691 /* In a type which contains a nested-name-specifier, template
20692 argument values cannot be deduced for template parameters used
20693 within the nested-name-specifier. */
20705 /* The PARM is not one we're trying to unify. Just check
20706 to see if it matches ARG. */
20707 {
20712 else
20714 }
20721 /* Check for mixed types and values. */
20729 {
20732 {
20733 /* First try to match ARG directly. */
20735 explain_p);
20737 {
20738 /* Otherwise, look for a suitable base of ARG, as below. */
20745 }
20746 }
20747 /* ARG must be constructed from a template class or a template
20748 template parameter. */
20753 /* Deduce arguments T, i from TT<T> or TT<i>. */
20759 /* Fall through to deduce template name. */
20760 }
20764 {
20765 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20767 /* Simple cases: Value already set, does match or doesn't. */
20772 }
20773 else
20774 {
20775 /* If PARM is `const T' and ARG is only `int', we don't have
20776 a match unless we are allowing additional qualification.
20777 If ARG is `const int' and PARM is just `T' that's OK;
20778 that binds `const int' to `T'. */
20783 /* Consider the case where ARG is `const volatile int' and
20784 PARM is `const T'. Then, T should be `volatile int'. */
20785 arg = cp_build_qualified_type_real
20790 /* Simple cases: Value already set, does match or doesn't. */
20796 /* Make sure that ARG is not a variable-sized array. (Note
20797 that were talking about variable-sized arrays (like
20798 `int[n]'), rather than arrays of unknown size (like
20799 `int[]').) We'll get very confused by such a type since
20800 the bound of the array is not constant, and therefore
20801 not mangleable. Besides, such types are not allowed in
20802 ISO C++, so we can do as we please here. We do allow
20803 them for 'auto' deduction, since that isn't ABI-exposed. */
20807 /* Strip typedefs as in convert_template_argument. */
20809 }
20811 /* If ARG is a parameter pack or an expansion, we cannot unify
20812 against it unless PARM is also a parameter pack. */
20817 /* If the argument deduction results is a METHOD_TYPE,
20818 then there is a problem.
20819 METHOD_TYPE doesn't map to any real C++ type the result of
20820 the deduction can not be of that type. */
20834 {
20835 /* The PARM is not one we're trying to unify. Just check
20836 to see if it matches ARG. */
20842 }
20848 {
20853 }
20855 /* [temp.deduct.type] If, in the declaration of a function template
20856 with a non-type template-parameter, the non-type
20857 template-parameter is used in an expression in the function
20858 parameter-list and, if the corresponding template-argument is
20859 deduced, the template-argument type shall match the type of the
20860 template-parameter exactly, except that a template-argument
20861 deduced from an array bound may be of any integral type.
20862 The non-type parameter might use already deduced type parameters. */
20865 {
20869 }
20872 /* Template-parameter dependent expression. Just accept it for now.
20873 It will later be processed in convert_template_argument. */
20874 ;
20880 /* Convert the ARG to the type of PARM; the deduced non-type
20881 template argument must exactly match the types of the
20882 corresponding parameter. */
20885 {
20886 /* We haven't deduced the type of this parameter yet. */
20888 /* We deduce from array bounds in try_array_deduction. */
20890 {
20891 /* Deduce it from the non-type argument. */
20896 }
20897 else
20898 /* Try again later. */
20900 }
20901 else
20904 /* If ARG is a parameter pack or an expansion, we cannot unify
20905 against it unless PARM is also a parameter pack. */
20910 {
20913 }
20918 {
20919 /* A pointer-to-member constant can be unified only with
20920 another constant. */
20924 /* Just unify the class member. It would be useless (and possibly
20925 wrong, depending on the strict flags) to unify also
20926 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20927 arg refer to the same variable, even if through different
20928 classes. For instance:
20930 struct A { int x; };
20931 struct B : A { };
20933 Unification of &A::x and &B::x must succeed. */
20936 }
20939 {
20943 /* [temp.deduct.call]
20945 A can be another pointer or pointer to member type that can
20946 be converted to the deduced A via a qualification
20947 conversion (_conv.qual_).
20949 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20950 This will allow for additional cv-qualification of the
20951 pointed-to types if appropriate. */
20954 /* The derived-to-base conversion only persists through one
20955 level of pointers. */
20960 }
20992 /* We have already checked cv-qualification at the top of the
20993 function. */
20997 /* As far as unification is concerned, this wins. Later checks
20998 will invalidate it if necessary. */
21001 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
21002 /* Type INTEGER_CST can come from ordinary constant template args. */
21014 {
21024 /* Check for pack expansions in the parameters. */
21026 {
21028 {
21030 /* We can unify against something with a trailing
21031 parameter pack. */
21033 else
21034 /* [temp.deduct.type]/9: If the template argument list of
21035 P contains a pack expansion that is not the last
21036 template argument, the entire template argument list
21037 is a non-deduced context. */
21039 }
21040 }
21042 /* If we don't have enough arguments to satisfy the parameters
21043 (not counting the pack expression at the end), or we have
21044 too many arguments for a parameter list that doesn't end in
21045 a pack expression, we can't unify. */
21051 /* Unify all of the parameters that precede the (optional)
21052 pack expression. */
21054 {
21059 }
21062 DEDUCE_EXACT,
21065 }
21073 {
21081 }
21086 {
21090 {
21091 /* First, we try to unify the PARM and ARG directly. */
21096 {
21097 /* Fallback to the special case allowed in
21098 [temp.deduct.call]:
21100 If P is a class, and P has the form
21101 template-id, then A can be a derived class of
21102 the deduced A. Likewise, if P is a pointer to
21103 a class of the form template-id, A can be a
21104 pointer to a derived class pointed to by the
21105 deduced A. */
21111 {
21112 /* Don't give the derived diagnostic if we're
21113 already dealing with the same template. */
21114 bool same_template
21120 }
21121 }
21122 }
21126 /* Perhaps PARM is something like S<U> and ARG is S<int>.
21127 Then, we should unify `int' and `U'. */
21129 else
21130 /* There's no chance of unification succeeding. */
21135 }
21142 {
21145 tree a;
21151 /* CV qualifications for methods can never be deduced, they must
21152 match exactly. We need to check them explicitly here,
21153 because type_unification_real treats them as any other
21154 cv-qualified parameter. */
21156 && (!check_cv_quals_for_unify
21184 {
21196 }
21199 }
21202 /* Unify a pointer to member with a pointer to member function, which
21203 deduces the type of the member as a function type. */
21205 {
21206 /* Check top-level cv qualifiers */
21214 /* Determine the type of the function we are unifying against. */
21218 }
21237 /* Matched cases are handled by the ARG == PARM test above. */
21241 /* We might get a variable as a non-type template argument in parm if the
21242 corresponding parameter is type-dependent. Make any necessary
21243 adjustments based on whether arg is a reference. */
21247 {
21252 }
21253 /* Now use the normal expression code to check whether they match. */
21264 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21265 or UNDERLYING_TYPE nodes. */
21269 /* Unification fails if we hit an error node. */
21274 {
21284 }
21285 /* FALLTHRU */
21288 /* An unresolved overload is a nondeduced context. */
21292 expr:
21293 /* We must be looking at an expression. This can happen with
21294 something like:
21296 template <int I>
21297 void foo(S<I>, S<I + 2>);
21299 This is a "nondeduced context":
21301 [deduct.type]
21303 The nondeduced contexts are:
21305 --A type that is a template-id in which one or more of
21306 the template-arguments is an expression that references
21307 a template-parameter.
21309 In these cases, we assume deduction succeeded, but don't
21310 actually infer any unifications. */
21315 else
21317 }
21318 }
21319 #undef RECUR_AND_CHECK_FAILURE
21320 \f
21321 /* Note that DECL can be defined in this translation unit, if
21322 required. */
21324 static void
21326 {
21327 tree clone;
21331 }
21333 /* Called if RESULT is explicitly instantiated, or is a member of an
21334 explicitly instantiated class. */
21336 void
21338 {
21341 /* If this entity has already been written out, it's too late to
21342 make any modifications. */
21346 /* For anonymous namespace we don't need to do anything. */
21348 {
21351 }
21354 /* The TREE_PUBLIC flag for function declarations will have been
21355 set correctly by tsubst. */
21358 /* This might have been set by an earlier implicit instantiation. */
21363 else
21364 {
21367 /* Always make artificials weak. */
21370 /* For WIN32 we also want to put explicit instantiations in
21371 linkonce sections. */
21374 }
21376 /* If EXTERN_P, then this function will not be emitted -- unless
21377 followed by an explicit instantiation, at which point its linkage
21378 will be adjusted. If !EXTERN_P, then this function will be
21379 emitted here. In neither circumstance do we want
21380 import_export_decl to adjust the linkage. */
21382 }
21384 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21385 important template arguments. If any are missing, we check whether
21386 they're important by using error_mark_node for substituting into any
21387 args that were used for partial ordering (the ones between ARGS and END)
21388 and seeing if it bubbles up. */
21390 static bool
21392 {
21397 {
21400 }
21402 {
21406 }
21408 }
21410 /* Given two function templates PAT1 and PAT2, return:
21412 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21413 -1 if PAT2 is more specialized than PAT1.
21414 0 if neither is more specialized.
21416 LEN indicates the number of parameters we should consider
21417 (defaulted parameters should not be considered).
21419 The 1998 std underspecified function template partial ordering, and
21420 DR214 addresses the issue. We take pairs of arguments, one from
21421 each of the templates, and deduce them against each other. One of
21422 the templates will be more specialized if all the *other*
21423 template's arguments deduce against its arguments and at least one
21424 of its arguments *does* *not* deduce against the other template's
21425 corresponding argument. Deduction is done as for class templates.
21426 The arguments used in deduction have reference and top level cv
21427 qualifiers removed. Iff both arguments were originally reference
21428 types *and* deduction succeeds in both directions, an lvalue reference
21429 wins against an rvalue reference and otherwise the template
21430 with the more cv-qualified argument wins for that pairing (if
21431 neither is more cv-qualified, they both are equal). Unlike regular
21432 deduction, after all the arguments have been deduced in this way,
21433 we do *not* verify the deduced template argument values can be
21434 substituted into non-deduced contexts.
21436 The logic can be a bit confusing here, because we look at deduce1 and
21437 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21438 can find template arguments for pat1 to make arg1 look like arg2, that
21439 means that arg2 is at least as specialized as arg1. */
21441 int
21443 {
21456 /* Remove the this parameter from non-static member functions. If
21457 one is a non-static member function and the other is not a static
21458 member function, remove the first parameter from that function
21459 also. This situation occurs for operator functions where we
21460 locate both a member function (with this pointer) and non-member
21461 operator (with explicit first operand). */
21463 {
21468 }
21470 {
21473 {
21474 len--;
21476 }
21477 }
21479 /* If only one is a conversion operator, they are unordered. */
21483 /* Consider the return type for a conversion function */
21485 {
21488 len++;
21489 }
21491 processing_template_decl++;
21497 /* Stop when an ellipsis is seen. */
21499 {
21510 {
21511 /* When both arguments are pack expansions, we need only
21512 unify the patterns themselves. */
21516 /* This is the last comparison we need to do. */
21518 }
21520 /* DR 1847: If a particular P contains no template-parameters that
21521 participate in template argument deduction, that P is not used to
21522 determine the ordering. */
21528 {
21532 }
21535 {
21539 }
21545 {
21551 /* Setup the parameter vector, which contains only ARG1. */
21554 /* Setup the argument vector, which contains the remaining
21555 arguments. */
21564 /* We cannot deduce in the other direction, because ARG1 is
21565 a pack expansion but ARG2 is not. */
21567 }
21569 {
21575 /* Setup the parameter vector, which contains only ARG1. */
21578 /* Setup the argument vector, which contains the remaining
21579 arguments. */
21588 /* We cannot deduce in the other direction, because ARG2 is
21589 a pack expansion but ARG1 is not.*/
21591 }
21593 else
21594 {
21595 /* The normal case, where neither argument is a pack
21596 expansion. */
21603 }
21605 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21606 arg2, then arg2 is not as specialized as arg1. */
21612 /* "If, for a given type, deduction succeeds in both directions
21613 (i.e., the types are identical after the transformations above)
21614 and both P and A were reference types (before being replaced with
21615 the type referred to above):
21616 - if the type from the argument template was an lvalue reference and
21617 the type from the parameter template was not, the argument type is
21618 considered to be more specialized than the other; otherwise,
21619 - if the type from the argument template is more cv-qualified
21620 than the type from the parameter template (as described above),
21621 the argument type is considered to be more specialized than the other;
21622 otherwise,
21623 - neither type is more specialized than the other." */
21626 {
21628 {
21631 else
21633 }
21635 {
21640 }
21641 }
21644 /* We've failed to deduce something in either direction.
21645 These must be unordered. */
21648 next:
21652 /* We have already processed all of the arguments in our
21653 handing of the pack expansion type. */
21658 }
21660 /* "In most cases, all template parameters must have values in order for
21661 deduction to succeed, but for partial ordering purposes a template
21662 parameter may remain without a value provided it is not used in the
21663 types being used for partial ordering."
21665 Thus, if we are missing any of the targs1 we need to substitute into
21666 origs1, then pat2 is not as specialized as pat1. This can happen when
21667 there is a nondeduced context. */
21673 processing_template_decl--;
21675 /* If both deductions succeed, the partial ordering selects the more
21676 constrained template. */
21678 {
21683 }
21685 /* All things being equal, if the next argument is a pack expansion
21686 for one function but not for the other, prefer the
21687 non-variadic function. FIXME this is bogus; see c++/41958. */
21691 {
21694 }
21700 else
21702 }
21704 /* Determine which of two partial specializations of TMPL is more
21705 specialized.
21707 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21708 to the first partial specialization. The TREE_PURPOSE is the
21709 innermost set of template parameters for the partial
21710 specialization. PAT2 is similar, but for the second template.
21712 Return 1 if the first partial specialization is more specialized;
21713 -1 if the second is more specialized; 0 if neither is more
21714 specialized.
21716 See [temp.class.order] for information about determining which of
21717 two templates is more specialized. */
21719 static int
21721 {
21722 tree targs;
21731 /* Just like what happens for functions, if we are ordering between
21732 different template specializations, we may encounter dependent
21733 types in the arguments, and we need our dependency check functions
21734 to behave correctly. */
21738 {
21741 }
21745 {
21748 }
21751 /* If both deductions succeed, the partial ordering selects the more
21752 constrained template. */
21756 /* In the case of a tie where at least one of the templates
21757 has a parameter pack at the end, the template with the most
21758 non-packed parameters wins. */
21760 && any_deductions
21763 {
21769 /* We don't count the pack expansion at the end. */
21779 }
21782 }
21784 /* Return the template arguments that will produce the function signature
21785 DECL from the function template FN, with the explicit template
21786 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21787 also match. Return NULL_TREE if no satisfactory arguments could be
21788 found. */
21790 static tree
21792 {
21796 tree decl_arg_types;
21799 tree arg;
21803 /* Never do unification on the 'this' parameter. */
21824 }
21826 /* Return the innermost template arguments that, when applied to a partial
21827 specialization SPEC_TMPL of TMPL, yield the ARGS.
21829 For example, suppose we have:
21831 template <class T, class U> struct S {};
21832 template <class T> struct S<T*, int> {};
21834 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21835 partial specialization and the ARGS will be {double*, int}. The resulting
21836 vector will be {double}, indicating that `T' is bound to `double'. */
21838 static tree
21840 {
21842 tree spec_args
21845 tree deduced_args;
21846 tree innermost_deduced_args;
21850 {
21854 innermost_deduced_args);
21855 }
21856 else
21860 again:
21869 {
21871 {
21877 }
21879 }
21883 {
21886 }
21888 /* Verify that nondeduced template arguments agree with the type
21889 obtained from argument deduction.
21891 For example:
21893 struct A { typedef int X; };
21894 template <class T, class U> struct C {};
21895 template <class T> struct C<T, typename T::X> {};
21897 Then with the instantiation `C<A, int>', we can deduce that
21898 `T' is `A' but unify () does not check whether `typename T::X'
21899 is `int'. */
21910 /* We only need to check the innermost arguments; the other
21911 arguments will always agree. */
21916 /* Now that we have bindings for all of the template arguments,
21917 ensure that the arguments deduced for the template template
21918 parameters have compatible template parameter lists. See the use
21919 of template_template_parm_bindings_ok_p in fn_type_unification
21920 for more information. */
21925 }
21927 // Compare two function templates T1 and T2 by deducing bindings
21928 // from one against the other. If both deductions succeed, compare
21929 // constraints to see which is more constrained.
21930 static int
21932 {
21937 {
21940 }
21943 {
21946 }
21948 // If both deductions succeed, then one may be more constrained.
21953 }
21955 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21956 Return the TREE_LIST node with the most specialized template, if
21957 any. If there is no most specialized template, the error_mark_node
21958 is returned.
21960 Note that this function does not look at, or modify, the
21961 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21962 returned is one of the elements of INSTANTIATIONS, callers may
21963 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21964 and retrieve it from the value returned. */
21966 tree
21968 {
21975 {
21981 {
21982 /* Equally specialized, move to next function. If there
21983 is no next function, nothing's most specialized. */
21988 }
21989 }
21992 /* Now verify that champ is better than everything earlier in the
21993 instantiation list. */
21996 {
21999 }
22000 }
22002 processing_template_decl--;
22008 }
22010 /* If DECL is a specialization of some template, return the most
22011 general such template. Otherwise, returns NULL_TREE.
22013 For example, given:
22015 template <class T> struct S { template <class U> void f(U); };
22017 if TMPL is `template <class U> void S<int>::f(U)' this will return
22018 the full template. This function will not trace past partial
22019 specializations, however. For example, given in addition:
22021 template <class T> struct S<T*> { template <class U> void f(U); };
22023 if TMPL is `template <class U> void S<int*>::f(U)' this will return
22024 `template <class T> template <class U> S<T*>::f(U)'. */
22026 tree
22028 {
22030 {
22033 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
22034 template friend, or a FIELD_DECL for a capture pack. */
22037 }
22039 /* Look for more and more general templates. */
22041 {
22042 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
22043 (See cp-tree.h for details.) */
22052 /* Stop if we run into an explicitly specialized class template. */
22059 }
22062 }
22064 /* Return the most specialized of the template partial specializations
22065 which can produce TARGET, a specialization of some class or variable
22066 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
22067 a TEMPLATE_DECL node corresponding to the partial specialization, while
22068 the TREE_PURPOSE is the set of template arguments that must be
22069 substituted into the template pattern in order to generate TARGET.
22071 If the choice of partial specialization is ambiguous, a diagnostic
22072 is issued, and the error_mark_node is returned. If there are no
22073 partial specializations matching TARGET, then NULL_TREE is
22074 returned, indicating that the primary template should be used. */
22076 static tree
22078 {
22080 tree t;
22081 tree champ;
22088 {
22092 }
22094 {
22097 }
22099 {
22103 }
22104 else
22109 /* For determining which partial specialization to use, only the
22110 innermost args are interesting. */
22112 {
22115 }
22118 {
22119 tree spec_args;
22123 {
22124 /* Substitute in the template args from the enclosing class. */
22128 }
22135 {
22139 /* Keep the candidate only if the constraints are satisfied,
22140 or if we're not compiling with concepts. */
22143 {
22146 }
22147 }
22148 }
22158 {
22161 ;
22162 else
22163 {
22165 {
22168 {
22171 }
22172 }
22174 }
22175 }
22179 {
22182 {
22185 }
22186 }
22189 {
22196 else
22200 {
22205 }
22208 }
22211 }
22213 /* Explicitly instantiate DECL. */
22215 void
22217 {
22222 /* An error occurred, for which grokdeclarator has already issued
22223 an appropriate message. */
22226 {
22229 }
22235 {
22236 /* There is an asymmetry here in the way VAR_DECLs and
22237 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22238 the latter, the DECL we get back will be marked as a
22239 template instantiation, and the appropriate
22240 DECL_TEMPLATE_INFO will be set up. This does not happen for
22241 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22242 should handle VAR_DECLs as it currently handles
22243 FUNCTION_DECLs. */
22245 {
22248 }
22251 {
22254 }
22256 {
22261 }
22262 }
22264 {
22267 }
22268 else
22271 /* Check for various error cases. Note that if the explicit
22272 instantiation is valid the RESULT will currently be marked as an
22273 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22274 until we get here. */
22277 {
22278 /* DR 259 [temp.spec].
22280 Both an explicit instantiation and a declaration of an explicit
22281 specialization shall not appear in a program unless the explicit
22282 instantiation follows a declaration of the explicit specialization.
22284 For a given set of template parameters, if an explicit
22285 instantiation of a template appears after a declaration of an
22286 explicit specialization for that template, the explicit
22287 instantiation has no effect. */
22289 }
22291 {
22292 /* [temp.spec]
22294 No program shall explicitly instantiate any template more
22295 than once.
22297 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22298 the first instantiation was `extern' and the second is not,
22299 and EXTERN_P for the opposite case. */
22302 /* If an "extern" explicit instantiation follows an ordinary
22303 explicit instantiation, the template is instantiated. */
22306 }
22308 {
22311 }
22313 {
22316 }
22319 ;
22321 {
22324 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22327 }
22328 else
22336 }
22338 static void
22340 {
22346 {
22349 }
22350 }
22352 /* Called from do_type_instantiation through binding_table_foreach to
22353 do recursive instantiation for the type bound in ENTRY. */
22354 static void
22356 {
22362 }
22364 /* Perform an explicit instantiation of template class T. STORAGE, if
22365 non-null, is the RID for extern, inline or static. COMPLAIN is
22366 nonzero if this is called from the parser, zero if called recursively,
22367 since the standard is unclear (as detailed below). */
22369 void
22371 {
22381 {
22382 tree tmpl =
22386 else
22389 }
22394 {
22397 t);
22399 }
22402 {
22404 {
22406 {
22409 "ISO C++ 1998 forbids the use of %<extern%> on "
22411 }
22412 else
22414 "ISO C++ forbids the use of %qE"
22416 }
22424 else
22425 {
22427 storage);
22429 }
22430 }
22433 {
22434 /* DR 259 [temp.spec].
22436 Both an explicit instantiation and a declaration of an explicit
22437 specialization shall not appear in a program unless the explicit
22438 instantiation follows a declaration of the explicit specialization.
22440 For a given set of template parameters, if an explicit
22441 instantiation of a template appears after a declaration of an
22442 explicit specialization for that template, the explicit
22443 instantiation has no effect. */
22445 }
22447 {
22448 /* [temp.spec]
22450 No program shall explicitly instantiate any template more
22451 than once.
22453 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22454 instantiation was `extern'. If EXTERN_P then the second is.
22455 These cases are OK. */
22462 /* If we've already instantiated the template, just return now. */
22465 }
22473 /* In contrast to implicit instantiation, where only the
22474 declarations, and not the definitions, of members are
22475 instantiated, we have here:
22477 [temp.explicit]
22479 The explicit instantiation of a class template specialization
22480 implies the instantiation of all of its members not
22481 previously explicitly specialized in the translation unit
22482 containing the explicit instantiation.
22484 Of course, we can't instantiate member template classes, since we
22485 don't have any arguments for them. Note that the standard is
22486 unclear on whether the instantiation of the members are
22487 *explicit* instantiations or not. However, the most natural
22488 interpretation is that it should be an explicit
22489 instantiation. */
22493 && !static_p
22496 {
22501 }
22506 }
22508 /* Given a function DECL, which is a specialization of TMPL, modify
22509 DECL to be a re-instantiation of TMPL with the same template
22510 arguments. TMPL should be the template into which tsubst'ing
22511 should occur for DECL, not the most general template.
22513 One reason for doing this is a scenario like this:
22515 template <class T>
22516 void f(const T&, int i);
22518 void g() { f(3, 7); }
22520 template <class T>
22521 void f(const T& t, const int i) { }
22523 Note that when the template is first instantiated, with
22524 instantiate_template, the resulting DECL will have no name for the
22525 first parameter, and the wrong type for the second. So, when we go
22526 to instantiate the DECL, we regenerate it. */
22528 static void
22530 {
22531 /* The arguments used to instantiate DECL, from the most general
22532 template. */
22533 tree code_pattern;
22537 /* Make sure that we can see identifiers, and compute access
22538 correctly. */
22542 {
22543 tree decl_parm;
22544 tree pattern_parm;
22545 tree specs;
22559 specs);
22561 /* Merge parameter declarations. */
22564 pattern_parm
22568 {
22569 tree parm_type;
22570 tree attributes;
22575 NULL_TREE);
22581 {
22584 }
22587 }
22588 /* Merge any parameters that match with the function parameter
22589 pack. */
22591 {
22593 tree expanded_types;
22594 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22595 the parameters in this function parameter pack. */
22600 {
22601 tree parm_type;
22602 tree attributes;
22605 /* Rename the parameter to include the index. */
22614 {
22617 }
22619 }
22620 }
22621 /* Merge additional specifiers from the CODE_PATTERN. */
22625 }
22627 {
22637 }
22638 else
22642 }
22644 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22645 substituted to get DECL. */
22647 tree
22649 {
22652 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22653 for the instantiation. This is not always the most general
22654 template. Consider, for example:
22656 template <class T>
22657 struct S { template <class U> void f();
22658 template <> void f<int>(); };
22660 and an instantiation of S<double>::f<int>. We want TD to be the
22661 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22663 more general template. */
22665 /* We must also deal with friend templates. Given:
22667 template <class T> struct S {
22668 template <class U> friend void f() {};
22669 };
22671 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22672 so far as the language is concerned, but that's still
22673 where we get the pattern for the instantiation from. On
22674 other hand, if the definition comes outside the class, say:
22676 template <class T> struct S {
22677 template <class U> friend void f();
22678 };
22679 template <class U> friend void f() {}
22681 we don't need to look any further. That's what the check for
22682 DECL_INITIAL is for. */
22686 {
22687 /* The present template, TD, should not be a definition. If it
22688 were a definition, we should be using it! Note that we
22689 cannot restructure the loop to just keep going until we find
22690 a template with a definition, since that might go too far if
22691 a specialization was declared, but not defined. */
22693 /* Fetch the more general template. */
22695 }
22698 }
22700 /* Returns true if we need to instantiate this template instance even if we
22701 know we aren't going to emit it. */
22703 bool
22705 {
22706 /* We always instantiate inline functions so that we can inline them. An
22707 explicit instantiation declaration prohibits implicit instantiation of
22708 non-inline functions. With high levels of optimization, we would
22709 normally inline non-inline functions -- but we're not allowed to do
22710 that for "extern template" functions. Therefore, we check
22711 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22715 /* And we need to instantiate static data members so that
22716 their initializers are available in integral constant
22717 expressions. */
22720 }
22722 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22723 instantiate it now, modifying TREE_TYPE (fn). Returns false on
22724 error, true otherwise. */
22726 bool
22728 {
22731 /* Don't instantiate a noexcept-specification from template context. */
22746 {
22752 {
22753 /* If hash_set::add returns true, the element was already there. */
22758 fn);
22760 }
22762 {
22777 }
22778 else
22788 }
22791 {
22794 else
22796 }
22799 }
22801 /* We're starting to process the function INST, an instantiation of PATTERN;
22802 add their parameters to local_specializations. */
22804 static void
22806 {
22810 {
22814 }
22816 {
22818 {
22821 }
22822 else
22823 {
22824 /* Register the (value) argument pack as a specialization of
22825 TMPL_PARM, then move on. */
22828 }
22829 }
22831 }
22833 /* Produce the definition of D, a _DECL generated from a template. If
22834 DEFER_OK is true, then we don't have to actually do the
22835 instantiation now; we just have to do it sometime. Normally it is
22836 an error if this is an explicit instantiation but D is undefined.
22837 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22838 instantiated class template. */
22840 tree
22842 {
22844 tree gen_args;
22845 tree args;
22846 tree td;
22847 tree code_pattern;
22848 tree spec;
22849 tree gen_tmpl;
22857 /* This function should only be used to instantiate templates for
22858 functions and static member variables. */
22861 /* A concept is never instantiated. */
22864 /* Variables are never deferred; if instantiation is required, they
22865 are instantiated right away. That allows for better code in the
22866 case that an expression refers to the value of the variable --
22867 if the variable has a constant value the referring expression can
22868 take advantage of that fact. */
22872 /* Don't instantiate cloned functions. Instead, instantiate the
22873 functions they cloned. */
22881 /* D has already been instantiated or explicitly specialized, so
22882 there's nothing for us to do here.
22884 It might seem reasonable to check whether or not D is an explicit
22885 instantiation, and, if so, stop here. But when an explicit
22886 instantiation is deferred until the end of the compilation,
22887 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22888 the instantiation. */
22891 /* Check to see whether we know that this template will be
22892 instantiated in some other file, as with "extern template"
22893 extension. */
22896 /* In general, we do not instantiate such templates. */
22904 /* We should already have the extra args. */
22907 /* And what's in the hash table should match D. */
22911 /* This needs to happen before any tsubsting. */
22917 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22918 for the instantiation. */
22923 {
22924 /* Look up an explicit specialization, if any. */
22928 {
22931 }
22932 }
22936 /* We should never be trying to instantiate a member of a class
22937 template or partial specialization. */
22942 /* In the case of a friend template whose definition is provided
22943 outside the class, we may have too many arguments. Drop the
22944 ones we don't need. The same is true for specializations. */
22945 args = get_innermost_template_args
22949 {
22955 }
22956 else
22957 {
22962 else
22964 }
22966 /* We may be in the middle of deferred access check. Disable it now. */
22969 /* Unless an explicit instantiation directive has already determined
22970 the linkage of D, remember that a definition is available for
22971 this entity. */
22981 /* If D is a member of an explicitly instantiated class template,
22982 and no definition is available, treat it like an implicit
22983 instantiation. */
22986 {
22987 /* Leave linkage flags alone on instantiations with anonymous
22988 visibility. */
22990 {
22993 }
22995 }
22997 /* Defer all other templates, unless we have been explicitly
22998 forbidden from doing so. */
23000 template. */
23001 ! pattern_defined
23002 /* If it's OK to postpone instantiation, do so. */
23003 || defer_ok
23004 /* If this is a static data member that will be defined
23005 elsewhere, we don't want to instantiate the entire data
23006 member, but we do want to instantiate the initializer so that
23007 we can substitute that elsewhere. */
23009 /* Handle here a deleted function too, avoid generating
23010 its body (c++/61080). */
23012 {
23013 /* The definition of the static data member is now required so
23014 we must substitute the initializer. */
23018 {
23019 tree ns;
23020 tree init;
23029 args,
23032 /* If instantiating the initializer involved instantiating this
23033 again, don't call cp_finish_decl twice. */
23035 {
23036 /* Make sure the initializer is still constant, in case of
23037 circular dependency (template/instantiate6.C). */
23038 const_init
23042 LOOKUP_ONLYCONVERTING);
23043 }
23047 }
23049 /* We restore the source position here because it's used by
23050 add_pending_template. */
23056 /* [temp.explicit]
23058 The definition of a non-exported function template, a
23059 non-exported member function template, or a non-exported
23060 member function or static data member of a class template
23061 shall be present in every translation unit in which it is
23062 explicitly instantiated. */
23066 /* If we're in unevaluated context, we just wanted to get the
23067 constant value; this isn't an odr use, so don't queue
23068 a full instantiation. */
23071 /* ??? Historically, we have instantiated inline functions, even
23072 when marked as "extern template". */
23076 }
23077 /* Tell the repository that D is available in this translation unit
23078 -- and see if it is supposed to be instantiated here. */
23080 {
23081 /* In a PCH file, despite the fact that the repository hasn't
23082 requested instantiation in the PCH it is still possible that
23083 an instantiation will be required in a file that includes the
23084 PCH. */
23087 /* Instantiate inline functions so that the inliner can do its
23088 job, even though we'll not be emitting a copy of this
23089 function. */
23092 }
23095 tree fn_context;
23106 else
23107 {
23111 }
23113 /* Mark D as instantiated so that recursive calls to
23114 instantiate_decl do not try to instantiate it again. */
23117 /* Regenerate the declaration in case the template has been modified
23118 by a subsequent redeclaration. */
23121 /* We already set the file and line above. Reset them now in case
23122 they changed as a result of calling regenerate_decl_from_template. */
23126 {
23127 tree init;
23130 /* Clear out DECL_RTL; whatever was there before may not be right
23131 since we've reset the type of the declaration. */
23135 /* The initializer is placed in DECL_INITIAL by
23136 regenerate_decl_from_template so we don't need to
23137 push/pop_access_scope again here. Pull it out so that
23138 cp_finish_decl can process it. */
23143 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
23144 initializer. That function will defer actual emission until
23145 we have a chance to determine linkage. */
23148 /* Enter the scope of D so that access-checking works correctly. */
23161 }
23165 {
23169 /* Save away the current list, in case we are instantiating one
23170 template from within the body of another. */
23173 /* Set up the list of local specializations. */
23176 /* Set up context. */
23180 else
23183 /* Some typedefs referenced from within the template code need to be
23184 access checked at template instantiation time, i.e now. These
23185 types were added to the template at parsing time. Let's get those
23186 and perform the access checks then. */
23188 args);
23190 /* Create substitution entries for the parameters. */
23193 /* Substitute into the body of the function. */
23197 else
23198 {
23203 /* Set the current input_location to the end of the function
23204 so that finish_function knows where we are. */
23205 input_location
23208 /* Remember if we saw an infinite loop in the template. */
23209 current_function_infinite_loop
23211 }
23213 /* We don't need the local specializations any more. */
23217 /* Finish the function. */
23221 else
23222 {
23225 }
23229 }
23231 /* We're not deferring instantiation any more. */
23236 else
23242 out:
23251 }
23253 /* Run through the list of templates that we wish we could
23254 instantiate, and instantiate any we can. RETRIES is the
23255 number of times we retry pending template instantiation. */
23257 void
23259 {
23263 /* Instantiating templates may trigger vtable generation. This in turn
23264 may require further template instantiations. We place a limit here
23265 to avoid infinite loop. */
23267 {
23271 "template instantiation depth exceeds maximum of %d"
23272 " instantiating %q+D, possibly from virtual table generation"
23276 /* Pretend that we defined it. */
23279 }
23281 do
23282 {
23287 {
23292 {
23294 {
23309 }
23312 }
23313 else
23314 {
23317 {
23318 instantiation
23324 }
23328 }
23331 /* If INSTANTIATION has been instantiated, then we don't
23332 need to consider it again in the future. */
23334 else
23335 {
23338 }
23341 }
23343 }
23347 }
23349 /* Substitute ARGVEC into T, which is a list of initializers for
23350 either base class or a non-static data member. The TREE_PURPOSEs
23351 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23352 instantiate_decl. */
23354 static tree
23356 {
23360 {
23361 tree decl;
23362 tree init;
23368 {
23369 tree expr;
23370 tree arg;
23372 /* Expand the base class expansion type into separate base
23373 classes. */
23375 tf_warning_or_error,
23376 NULL_TREE);
23380 /* We'll be building separate TREE_LISTs of arguments for
23381 each base. */
23387 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23388 expand each argument in the TREE_VALUE of t. */
23395 /* VOID_TYPE_NODE is used to indicate
23396 value-initialization. */
23397 {
23400 }
23401 else
23402 {
23403 /* Substitute parameter packs into each argument in the
23404 TREE_LIST. */
23407 {
23408 tree expanded_exprs;
23410 /* Expand the argument. */
23412 expanded_exprs
23414 tf_warning_or_error,
23415 NULL_TREE);
23419 /* Prepend each of the expanded expressions to the
23420 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23422 {
23427 }
23428 }
23431 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23432 since we built them backwards. */
23434 {
23437 }
23438 }
23439 }
23442 {
23444 {
23448 }
23449 else
23450 {
23451 tree tmp;
23466 /* If we had an initializer but it instantiated to nothing,
23467 value-initialize the object. This will only occur when
23468 the initializer was a pack expansion where the parameter
23469 packs used in that expansion were of length zero. */
23472 }
23475 {
23479 }
23480 }
23481 }
23483 }
23485 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23487 static void
23489 {
23494 else
23496 }
23498 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23499 is the instantiation (which should have been created with
23500 start_enum) and ARGS are the template arguments to use. */
23502 static void
23504 {
23505 tree e;
23511 {
23512 tree value;
23513 tree decl;
23516 /* Note that in a template enum, the TREE_VALUE is the
23517 CONST_DECL, not the corresponding INTEGER_CST. */
23522 /* Give this enumeration constant the correct access. */
23525 /* Actually build the enumerator itself. Here we're assuming that
23526 enumerators can't have dependent attributes. */
23529 }
23539 }
23541 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23542 its type -- but without substituting the innermost set of template
23543 arguments. So, innermost set of template parameters will appear in
23544 the type. */
23546 tree
23548 {
23549 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23551 }
23553 /* Return truthvalue if we're processing a template different from
23554 the last one involved in diagnostics. */
23555 bool
23557 {
23559 }
23561 /* Remember current template involved in diagnostics. */
23562 void
23564 {
23566 }
23570 {
23572 }
23574 /* Return TRUE if current_function_decl is being instantiated, false
23575 otherwise. */
23577 bool
23579 {
23582 }
23584 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23585 type. Return zero for ok, nonzero for disallowed. Issue error and
23586 warning messages under control of COMPLAIN. */
23588 static int
23590 {
23605 /* A bound template template parm could later be instantiated to have a valid
23606 nontype parm type via an alias template. */
23612 {
23615 else
23617 type);
23618 }
23620 }
23622 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23623 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23625 static bool
23627 {
23628 tree scope;
23630 /* [temp.dep.type]
23632 A type is dependent if it is:
23634 -- a template parameter. Template template parameters are types
23635 for us (since TYPE_P holds true for them) so we handle
23636 them here. */
23640 /* -- a qualified-id with a nested-name-specifier which contains a
23641 class-name that names a dependent type or whose unqualified-id
23642 names a dependent type. */
23646 /* An alias template specialization can be dependent even if the
23647 resulting type is not. */
23651 /* -- a cv-qualified type where the cv-unqualified type is
23652 dependent.
23653 No code is necessary for this bullet; the code below handles
23654 cv-qualified types, and we don't want to strip aliases with
23655 TYPE_MAIN_VARIANT because of DR 1558. */
23656 /* -- a compound type constructed from any dependent type. */
23666 {
23667 tree arg_type;
23672 arg_type;
23677 {
23678 /* A value-dependent noexcept-specifier makes the type dependent. */
23683 }
23685 }
23686 /* -- an array type constructed from any dependent type or whose
23687 size is specified by a constant expression that is
23688 value-dependent.
23690 We checked for type- and value-dependence of the bounds in
23691 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23693 {
23698 }
23700 /* -- a template-id in which either the template name is a template
23701 parameter ... */
23704 /* ... or any of the template arguments is a dependent type or
23705 an expression that is type-dependent or value-dependent. */
23707 && (any_dependent_template_arguments_p
23711 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23712 dependent; if the argument of the `typeof' expression is not
23713 type-dependent, then it should already been have resolved. */
23719 /* A template argument pack is dependent if any of its packed
23720 arguments are. */
23722 {
23728 }
23730 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23731 be template parameters. */
23738 /* The standard does not specifically mention types that are local
23739 to template functions or local classes, but they should be
23740 considered dependent too. For example:
23742 template <int I> void f() {
23743 enum E { a = I };
23744 S<sizeof (E)> s;
23745 }
23747 The size of `E' cannot be known until the value of `I' has been
23748 determined. Therefore, `E' must be considered dependent. */
23752 /* Don't use type_dependent_expression_p here, as it can lead
23753 to infinite recursion trying to determine whether a lambda
23754 nested in a lambda is dependent (c++/47687). */
23758 && (any_dependent_template_arguments_p
23762 /* Other types are non-dependent. */
23764 }
23766 /* Returns TRUE if TYPE is dependent, in the sense of
23767 [temp.dep.type]. Note that a NULL type is considered dependent. */
23769 bool
23771 {
23772 /* If there are no template parameters in scope, then there can't be
23773 any dependent types. */
23775 {
23776 /* If we are not processing a template, then nobody should be
23777 providing us with a dependent type. */
23781 }
23783 /* If the type is NULL, we have not computed a type for the entity
23784 in question; in that case, the type is dependent. */
23788 /* Erroneous types can be considered non-dependent. */
23792 /* Getting here with global_type_node means we improperly called this
23793 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23796 /* If we have not already computed the appropriate value for TYPE,
23797 do so now. */
23799 {
23802 }
23805 }
23807 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23808 lookup. In other words, a dependent type that is not the current
23809 instantiation. */
23811 bool
23813 {
23816 }
23818 /* T is a SCOPE_REF; return whether we need to consider it
23819 instantiation-dependent so that we can check access at instantiation
23820 time even though we know which member it resolves to. */
23822 static bool
23824 {
23830 else
23832 }
23834 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23835 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23836 expression. */
23838 /* Note that this predicate is not appropriate for general expressions;
23839 only constant expressions (that satisfy potential_constant_expression)
23840 can be tested for value dependence. */
23842 bool
23844 {
23848 /* A name declared with a dependent type. */
23853 {
23855 /* A dependent member function of the current instantiation. */
23859 /* A dependent member function of the current instantiation. */
23866 /* A name that has not been looked up -- must be dependent. */
23870 /* A non-type template parm. */
23874 /* A non-type template parm. */
23880 /* A constant with literal type and is initialized
23881 with an expression that is value-dependent.
23883 Note that a non-dependent parenthesized initializer will have
23884 already been replaced with its constant value, so if we see
23885 a TREE_LIST it must be dependent. */
23889 /* cp_finish_decl doesn't fold reference initializers. */
23895 {
23899 }
23907 /* These expressions are value-dependent if the type to which
23908 the cast occurs is dependent or the expression being casted
23909 is value-dependent. */
23910 {
23916 /* A functional cast has a list of operands. */
23919 {
23920 /* If there are no operands, it must be an expression such
23921 as "int()". This should not happen for aggregate types
23922 because it would form non-constant expressions. */
23927 }
23933 }
23938 /* FALLTHRU */
23941 /* A `sizeof' expression is value-dependent if the operand is
23942 type-dependent or is a pack expansion. */
23951 /* An 'encode' expression is value-dependent if the operand is
23952 type-dependent. */
23961 /* All instantiation-dependent expressions should also be considered
23962 value-dependent. */
23970 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23971 is value-dependent. */
23972 {
23981 }
23984 {
23988 }
23999 {
24003 }
24006 /* Treat all requires-expressions as value-dependent so
24007 we don't try to fold them. */
24014 {
24021 {
24023 /* In a call to a constexpr member function, look through the
24024 implicit ADDR_EXPR on the object argument so that it doesn't
24025 cause the call to be considered value-dependent. We also
24026 look through it in potential_constant_expression. */
24033 }
24035 }
24038 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
24039 type-dependent. */
24044 {
24046 tree val;
24053 }
24056 /* Treat a GNU statement expression as dependent to avoid crashing
24057 under instantiate_non_dependent_expr; it can't be constant. */
24061 /* A constant expression is value-dependent if any subexpression is
24062 value-dependent. */
24064 {
24071 {
24075 {
24078 /* In some cases, some of the operands may be missing.
24079 (For example, in the case of PREDECREMENT_EXPR, the
24080 amount to increment by may be missing.) That doesn't
24081 make the expression dependent. */
24084 }
24085 }
24089 }
24091 }
24093 /* The expression is not value-dependent. */
24095 }
24097 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
24098 [temp.dep.expr]. Note that an expression with no type is
24099 considered dependent. Other parts of the compiler arrange for an
24100 expression with type-dependent subexpressions to have no type, so
24101 this function doesn't have to be fully recursive. */
24103 bool
24105 {
24112 /* An unresolved name is always dependent. */
24118 /* A fold expression is type-dependent. */
24125 /* Some expression forms are never type-dependent. */
24139 /* The types of these expressions depends only on the type to which
24140 the cast occurs. */
24149 /* The types of these expressions depends only on the type created
24150 by the expression. */
24153 {
24154 /* For NEW_EXPR tree nodes created inside a template, either
24155 the object type itself or a TREE_LIST may appear as the
24156 operand 1. */
24159 /* This is an array type. We need to check array dimensions
24160 as well. */
24162 || value_dependent_expression_p
24164 else
24166 }
24169 {
24173 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
24174 contains an identifier associated by name lookup with one or more
24175 declarations declared with a dependent type, or...a
24176 nested-name-specifier or qualified-id that names a member of an
24177 unknown specialization. */
24180 }
24190 {
24191 tree elt;
24195 {
24198 }
24200 }
24202 /* A static data member of the current instantiation with incomplete
24203 array type is type-dependent, as the definition and specializations
24204 can have different bounds. */
24211 /* An array of unknown bound depending on a variadic parameter, eg:
24213 template<typename... Args>
24214 void foo (Args... args)
24215 {
24216 int arr[] = { args... };
24217 }
24219 template<int... vals>
24220 void bar ()
24221 {
24222 int arr[] = { vals... };
24223 }
24225 If the array has no length and has an initializer, it must be that
24226 we couldn't determine its length in cp_complete_array_type because
24227 it is dependent. */
24235 /* A function or variable template-id is type-dependent if it has any
24236 dependent template arguments. */
24240 {
24241 /* Consider the innermost template arguments, since those are the ones
24242 that come from the template-id; the template arguments for the
24243 enclosing class do not make it type-dependent unless they are used in
24244 the type of the decl. */
24246 && (any_dependent_template_arguments_p
24250 /* Otherwise, if the decl isn't from a dependent scope, it can't be
24251 type-dependent. Checking this is important for functions with auto
24252 return type, which looks like a dependent type. */
24259 {
24263 }
24264 }
24266 /* Always dependent, on the number of arguments if nothing else. */
24271 {
24276 {
24282 }
24283 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24288 {
24293 }
24296 {
24303 }
24313 }
24317 /* Dependent type attributes might not have made it from the decl to
24318 the type yet. */
24324 }
24326 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24327 type-dependent if the expression refers to a member of the current
24328 instantiation and the type of the referenced member is dependent, or the
24329 class member access expression refers to a member of an unknown
24330 specialization.
24332 This function returns true if the OBJECT in such a class member access
24333 expression is of an unknown specialization. */
24335 bool
24337 {
24338 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24339 dependent. */
24344 }
24346 /* walk_tree callback function for instantiation_dependent_expression_p,
24347 below. Returns non-zero if a dependent subexpression is found. */
24349 static tree
24352 {
24354 {
24355 /* We don't have to worry about decltype currently because decltype
24356 of an instantiation-dependent expr is a dependent type. This
24357 might change depending on the resolution of DR 1172. */
24360 }
24363 {
24364 /* Don't treat an argument list as dependent just because it has no
24365 TREE_TYPE. */
24373 /* Handle expressions with type operands. */
24378 {
24383 {
24386 else
24387 {
24390 }
24391 }
24393 }
24397 /* In a template, finish_class_member_access_expr creates a
24398 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24399 type-dependent, so that we can check access control at
24400 instantiation time (PR 42277). See also Core issue 1273. */
24407 else
24410 /* Treat statement-expressions as dependent. */
24414 /* Treat requires-expressions as dependent. */
24419 /* Treat calls to function concepts as dependent. */
24425 /* And variable concepts. */
24432 }
24436 else
24438 }
24440 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24441 sense defined by the ABI:
24443 "An expression is instantiation-dependent if it is type-dependent
24444 or value-dependent, or it has a subexpression that is type-dependent
24445 or value-dependent."
24447 Except don't actually check value-dependence for unevaluated expressions,
24448 because in sizeof(i) we don't care about the value of i. Checking
24449 type-dependence will in turn check value-dependence of array bounds/template
24450 arguments as needed. */
24452 bool
24454 {
24455 tree result;
24466 }
24468 /* As above, but also check value-dependence of the expression as a whole. */
24470 bool
24472 {
24475 }
24477 /* Like type_dependent_expression_p, but it also works while not processing
24478 a template definition, i.e. during substitution or mangling. */
24480 bool
24482 {
24488 }
24490 /* Returns TRUE if ARGS contains a type-dependent expression. */
24492 bool
24494 {
24496 tree arg;
24499 {
24502 }
24504 }
24506 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24507 expressions) contains any type-dependent expressions. */
24509 bool
24511 {
24517 }
24519 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24520 expressions) contains any value-dependent expressions. */
24522 bool
24524 {
24530 }
24532 /* Returns TRUE if the ARG (a template argument) is dependent. */
24534 bool
24536 {
24540 /* Assume a template argument that was wrongly written by the user
24541 is dependent. This is consistent with what
24542 any_dependent_template_arguments_p [that calls this function]
24543 does. */
24553 {
24556 /* A member template of a dependent class is not necessarily
24557 type-dependent, but it is a dependent template argument because it
24558 will be a member of an unknown specialization to that template. */
24561 }
24563 {
24567 {
24570 }
24573 }
24576 else
24579 }
24581 /* Returns true if ARGS (a collection of template arguments) contains
24582 any types that require structural equality testing. */
24584 bool
24586 {
24596 {
24599 {
24605 {
24606 /* Look inside the argument pack. */
24609 }
24612 {
24625 }
24626 }
24627 }
24630 }
24632 /* Returns true if ARGS (a collection of template arguments) contains
24633 any dependent arguments. */
24635 bool
24637 {
24647 {
24652 }
24655 }
24657 /* Returns TRUE if the template TMPL is type-dependent. */
24659 bool
24661 {
24663 {
24668 }
24670 /* Template template parameters are dependent. */
24674 /* So are names that have not been looked up. */
24678 }
24680 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24682 bool
24684 {
24687 }
24689 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24690 are dependent. */
24692 bool
24694 {
24701 {
24723 {
24727 }
24731 {
24735 {
24740 }
24741 }
24742 }
24745 }
24747 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24748 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24749 no such TYPE can be found. Note that this function peers inside
24750 uninstantiated templates and therefore should be used only in
24751 extremely limited situations. ONLY_CURRENT_P restricts this
24752 peering to the currently open classes hierarchy (which is required
24753 when comparing types). */
24755 tree
24757 {
24758 tree scope;
24759 tree name;
24760 tree decl;
24762 tree pushed_scope;
24763 tree result;
24768 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24769 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24770 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24771 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24772 identifier of the TYPENAME_TYPE anymore.
24773 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24774 TYPENAME_TYPE instead, we avoid messing up with a possible
24775 typedef variant case. */
24778 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24779 it first before we can figure out what NAME refers to. */
24781 {
24783 /* Given a class template A with a dependent base with nested type C,
24784 typedef typename A::C::C C will land us here, as trying to resolve
24785 the initial A::C leads to the local C typedef, which leads back to
24786 A::C::C. So we break the recursion now. */
24788 else
24790 }
24791 /* If we don't know what SCOPE refers to, then we cannot resolve the
24792 TYPENAME_TYPE. */
24795 /* If this is a typedef, we don't want to look inside (c++/11987). */
24798 /* If SCOPE isn't the template itself, it will not have a valid
24799 TYPE_FIELDS list. */
24801 /* scope is either the template itself or a compatible instantiation
24802 like X<T>, so look up the name in the original template. */
24804 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24806 /* If scope has no fields, it can't be a current instantiation. Check this
24807 before currently_open_class to avoid infinite recursion (71515). */
24810 /* If the SCOPE is not the current instantiation, there's no reason
24811 to look inside it. */
24814 /* Enter the SCOPE so that name lookup will be resolved as if we
24815 were in the class definition. In particular, SCOPE will no
24816 longer be considered a dependent type. */
24818 /* Look up the declaration. */
24820 tf_warning_or_error);
24824 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24825 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24831 {
24835 }
24838 {
24839 /* Obtain the template and the arguments. */
24842 {
24843 /* We get here with a plain identifier because a previous tentative
24844 parse of the nested-name-specifier as part of a ptr-operator saw
24845 ::template X<A>. The use of ::template is necessary in a
24846 ptr-operator, but wrong in a declarator-id.
24848 [temp.names]: In a qualified-id of a declarator-id, the keyword
24849 template shall not appear at the top level. */
24853 }
24855 /* Instantiate the template. */
24861 }
24863 /* Leave the SCOPE. */
24867 /* If we failed to resolve it, return the original typename. */
24871 /* If lookup found a typename type, resolve that too. */
24873 {
24874 /* Ill-formed programs can cause infinite recursion here, so we
24875 must catch that. */
24879 }
24881 /* Qualify the resulting type. */
24887 }
24889 /* EXPR is an expression which is not type-dependent. Return a proxy
24890 for EXPR that can be used to compute the types of larger
24891 expressions containing EXPR. */
24893 tree
24895 {
24896 tree inner_expr;
24898 /* When checking, try to get a constant value for all non-dependent
24899 expressions in order to expose bugs in *_dependent_expression_p
24900 and constexpr. This can affect code generation, see PR70704, so
24901 only do this for -fchecking=2. */
24904 /* Don't do this during nsdmi parsing as it can lead to
24905 unexpected recursive instantiations. */
24907 /* Don't do this during concept expansion either and for
24908 the same reason. */
24912 /* Preserve OVERLOADs; the functions must be available to resolve
24913 types. */
24924 /* There is no need to return a proxy for a variable. */
24927 /* Preserve string constants; conversions from string constants to
24928 "char *" are allowed, even though normally a "const char *"
24929 cannot be used to initialize a "char *". */
24932 /* Preserve void and arithmetic constants, as an optimization -- there is no
24933 reason to create a new node. */
24938 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24939 There is at least one place where we want to know that a
24940 particular expression is a throw-expression: when checking a ?:
24941 expression, there are special rules if the second or third
24942 argument is a throw-expression. */
24946 /* Don't wrap an initializer list, we need to be able to look inside. */
24950 /* Don't wrap a dummy object, we need to be able to test for it. */
24969 /* If the type is unknown, it can't really be non-dependent */
24972 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24974 }
24976 /* ARGS is a vector of expressions as arguments to a function call.
24977 Replace the arguments with equivalent non-dependent expressions.
24978 This modifies ARGS in place. */
24980 void
24982 {
24984 tree arg;
24987 {
24991 }
24992 }
24994 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24995 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24996 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24998 static tree
25000 {
25014 }
25016 tree
25018 {
25020 }
25022 tree
25024 {
25026 }
25028 /* Return a C++17 deduction placeholder for class template TMPL. */
25030 tree
25032 {
25036 }
25038 /* True iff T is a C++17 class template deduction placeholder. */
25040 bool
25042 {
25044 }
25046 /* Make a "constrained auto" type-specifier. This is an
25047 auto type with constraints that must be associated after
25048 deduction. The constraint is formed from the given
25049 CONC and its optional sequence of arguments, which are
25050 non-null if written as partial-concept-id. */
25052 tree
25054 {
25057 /* Build the constraint. */
25065 /* Our canonical type depends on the constraint. */
25068 /* Attach the constraint to the type declaration. */
25071 }
25073 /* Given type ARG, return std::initializer_list<ARG>. */
25075 static tree
25077 {
25081 {
25085 "deducing from brace-enclosed initializer list"
25089 }
25095 }
25097 /* Replace auto in TYPE with std::initializer_list<auto>. */
25099 static tree
25101 {
25108 }
25110 /* Hash traits for hashing possibly constrained 'auto'
25111 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
25114 {
25117 };
25119 /* Hash the 'auto' T. */
25121 inline hashval_t
25123 {
25125 /* Matching constrained-type-specifiers denote the same template
25126 parameter, so hash the constraint. */
25128 else
25129 /* But unconstrained autos are all separate, so just hash the pointer. */
25131 }
25133 /* Compare two 'auto's. */
25137 {
25144 /* Two unconstrained autos are distinct. */
25149 }
25151 /* for_each_template_parm callback for extract_autos: if t is a (possibly
25152 constrained) auto, add it to the vector. */
25154 static int
25156 {
25159 {
25160 /* All the autos were built with index 0; fix that up now. */
25164 /* If this is a repeated constrained-type-specifier, use the index we
25165 chose before. */
25167 else
25168 {
25169 /* Otherwise this is new, so use the current count. */
25172 }
25174 }
25176 /* Always keep walking. */
25178 }
25180 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
25181 says they can appear anywhere in the type. */
25183 static tree
25185 {
25194 {
25199 }
25202 }
25204 /* The stem for deduction guide names. */
25207 /* Return the name for a deduction guide for class template TMPL. */
25209 tree
25211 {
25222 }
25224 /* True if NAME is the name of a deduction guide. */
25226 bool
25228 {
25232 }
25234 /* True if FN is a deduction guide. */
25236 bool
25238 {
25243 }
25245 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
25247 bool
25249 {
25256 }
25258 /* True if FN is a guide generated from a constructor template. */
25260 bool
25262 {
25270 }
25272 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
25273 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
25274 template parameter types. Note that the handling of template template
25275 parameters relies on current_template_parms being set appropriately for the
25276 new template. */
25278 static tree
25281 {
25284 tree newtype;
25287 {
25294 }
25295 else
25299 tree newdecl
25304 tree newidx;
25307 {
25317 {
25322 // First create a copy (ttargs) of tsubst_args with an
25323 // additional level for the template template parameter's own
25324 // template parameters (ttparms).
25325 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25333 // Substitute ttargs into ttparms to fix references to
25334 // other template parameters.
25336 complain);
25337 // Now substitute again with args based on tparms, to reduce
25338 // the level of the ttparms.
25341 complain);
25342 // Finally, tack the adjusted parms onto tparms.
25344 current_template_parms);
25346 }
25347 }
25348 else
25349 {
25351 tree newconst
25363 }
25366 }
25368 /* Returns a C++17 class deduction guide template based on the constructor
25369 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25370 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25372 static tree
25374 {
25378 location_t loc;
25382 {
25386 {
25389 }
25390 else
25400 }
25401 else
25402 {
25405 fn_tmpl
25415 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25416 fully specialized args for the enclosing class. Strip those off, as
25417 the deduction guide won't have those template parameters. */
25420 /* Discard the 'this' parameter. */
25428 {
25431 /* For a member template constructor, we need to flatten the two
25432 template parameter lists into one, and then adjust the function
25433 signature accordingly. This gets...complicated. */
25436 /* For a member template we should have two levels of parms/args, one
25437 for the class and one for the constructor. We stripped
25438 specialized args for further enclosing classes above. */
25442 /* Template args for translating references to the two-level template
25443 parameters into references to the one-level template parameters we
25444 are creating. */
25449 /* Template parms for the constructor template. */
25452 /* Template parms for the class template. */
25456 /* Template parms for the deduction guide start as a copy of the
25457 template parms for the class. We set current_template_parms for
25458 lookup_template_class_1. */
25464 /* Now we need to rewrite the constructor parms to append them to the
25465 class parms. */
25467 {
25482 }
25484 /* Now we have a final set of template parms to substitute into the
25485 function signature. */
25494 }
25496 }
25499 {
25500 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25504 }
25508 FUNCTION_DECL,
25525 }
25527 /* Deduce template arguments for the class template placeholder PTYPE for
25528 template TMPL based on the initializer INIT, and return the resulting
25529 type. */
25531 static tree
25533 tsubst_flags_t complain)
25534 {
25536 {
25537 /* We should have handled this in the caller. */
25543 }
25554 {
25557 {
25558 /* As an exception, the first phase in 16.3.1.7 (considering the
25559 initializer list as a single argument) is omitted if the
25560 initializer list consists of a single expression of type cv U,
25561 where U is a specialization of C or a class derived from a
25562 specialization of C. */
25573 }
25576 else
25578 }
25579 else
25590 /* Prune explicit deduction guides in copy-initialization context. */
25592 {
25598 {
25599 /* Found a nonconverting guide, prune the candidates. */
25606 }
25607 }
25612 {
25615 }
25619 // FIXME cache artificial deduction guides
25622 {
25627 else
25631 }
25635 /* If this is list-initialization and the class has a list constructor, first
25636 try deducing from the list as a single argument, as [over.match.list]. */
25640 {
25644 }
25646 {
25652 {
25653 /* That didn't work, now try treating the list as a sequence of
25654 arguments. */
25657 }
25658 }
25660 /* Maybe generate an implicit deduction guide. */
25662 {
25666 /* Generate a copy guide. */
25669 /* Generate a default guide. */
25673 {
25676 }
25677 }
25680 {
25682 " of %qT, as it has no non-explicit deduction guides or "
25685 }
25687 {
25691 }
25694 {
25698 }
25701 {
25711 }
25716 }
25718 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25719 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25721 tree
25723 {
25725 tf_warning_or_error,
25726 adc_unspecified);
25727 }
25729 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25730 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25731 The CONTEXT determines the context in which auto deduction is performed
25732 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25733 OUTER_TARGS are used during template argument deduction
25734 (context == adc_unify) to properly substitute the result, and is ignored
25735 in other contexts.
25737 For partial-concept-ids, extra args may be appended to the list of deduced
25738 template arguments prior to determining constraint satisfaction. */
25740 tree
25744 {
25745 tree targs;
25752 /* Defining a subset of type-dependent expressions that we can deduce
25753 from ahead of time isn't worth the trouble. */
25757 /* C++17 class template argument deduction. */
25761 /* Nothing we can do with this, even in deduction context. */
25764 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25765 with either a new invented type template parameter U or, if the
25766 initializer is a braced-init-list (8.5.4), with
25767 std::initializer_list<U>. */
25769 {
25774 else
25775 {
25777 {
25781 "for deduction to %<std::initializer_list%>, use copy-"
25783 }
25785 }
25786 }
25797 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25798 and initializer has array type, deduce cv-qualified array type. */
25800 complain);
25802 {
25811 {
25815 }
25816 }
25817 else
25818 {
25820 tree tparms;
25824 else
25825 {
25829 }
25836 {
25838 /* Try again at instantiation time. */
25842 /* If type is error_mark_node a diagnostic must have been
25843 emitted by now. Also, having a mention to '<type error>'
25844 in the diagnostic is not really useful to the user. */
25845 {
25849 else
25854 }
25856 }
25857 }
25859 /* Check any placeholder constraints against the deduced type. */
25862 {
25863 /* Use the deduced type to check the associated constraints. If we
25864 have a partial-concept-id, rebuild the argument list so that
25865 we check using the extra arguments. */
25869 {
25872 }
25873 else
25876 {
25878 {
25880 {
25898 }
25900 }
25902 }
25903 }
25909 }
25911 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25912 result. */
25914 tree
25916 {
25918 {
25924 /* In an abbreviated function template we didn't know we were dealing
25925 with a function template when we saw the auto return type, so update
25926 it to have the correct level. */
25928 }
25930 }
25932 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25933 'decltype(auto)' or a deduced class template. */
25935 bool
25937 {
25943 else
25945 }
25947 /* for_each_template_parm callback for type_uses_auto. */
25949 int
25951 {
25953 }
25955 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25956 a use of `auto'. Returns NULL_TREE otherwise. */
25958 tree
25960 {
25964 {
25965 /* The Concepts TS allows multiple autos in one type-specifier; just
25966 return the first one we find, do_auto_deduction will collect all of
25967 them. */
25971 else
25973 }
25974 else
25976 }
25978 /* For a given template T, return the vector of typedefs referenced
25979 in T for which access check is needed at T instantiation time.
25980 T is either a FUNCTION_DECL or a RECORD_TYPE.
25981 Those typedefs were added to T by the function
25982 append_type_to_template_for_access_check. */
25986 {
25987 tree ti;
25998 {
26003 }
26006 }
26008 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
26009 tied to T. That list of typedefs will be access checked at
26010 T instantiation time.
26011 T is either a FUNCTION_DECL or a RECORD_TYPE.
26012 TYPE_DECL is a TYPE_DECL node representing a typedef.
26013 SCOPE is the scope through which TYPE_DECL is accessed.
26014 LOCATION is the location of the usage point of TYPE_DECL.
26016 This function is a subroutine of
26017 append_type_to_template_for_access_check. */
26019 static void
26021 tree type_decl,
26022 tree scope,
26023 location_t location)
26024 {
26025 qualified_typedef_usage_t typedef_usage;
26026 tree ti;
26033 && type_decl
26047 }
26049 /* Append TYPE_DECL to the template TEMPL.
26050 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
26051 At TEMPL instanciation time, TYPE_DECL will be checked to see
26052 if it can be accessed through SCOPE.
26053 LOCATION is the location of the usage point of TYPE_DECL.
26055 e.g. consider the following code snippet:
26057 class C
26058 {
26059 typedef int myint;
26060 };
26062 template<class U> struct S
26063 {
26064 C::myint mi; // <-- usage point of the typedef C::myint
26065 };
26067 S<char> s;
26069 At S<char> instantiation time, we need to check the access of C::myint
26070 In other words, we need to check the access of the myint typedef through
26071 the C scope. For that purpose, this function will add the myint typedef
26072 and the scope C through which its being accessed to a list of typedefs
26073 tied to the template S. That list will be walked at template instantiation
26074 time and access check performed on each typedefs it contains.
26075 Note that this particular code snippet should yield an error because
26076 myint is private to C. */
26078 void
26080 tree type_decl,
26081 tree scope,
26082 location_t location)
26083 {
26089 /* Make sure we don't append the type to the template twice. */
26096 }
26098 /* Convert the generic type parameters in PARM that match the types given in the
26099 range [START_IDX, END_IDX) from the current_template_parms into generic type
26100 packs. */
26102 tree
26104 {
26115 {
26116 /* Create a distinct parameter pack type from the current parm and add it
26117 to the replacement args to tsubst below into the generic function
26118 parameter. */
26133 }
26139 /* If there are more levels then build up the replacement with the outer
26140 template parms. */
26144 replacement);
26147 }
26149 /* Entries in the decl_constraint hash table. */
26151 {
26152 tree decl;
26153 tree ci;
26154 };
26156 /* Hashing function and equality for constraint entries. */
26158 {
26160 {
26162 }
26165 {
26167 }
26168 };
26170 /* A mapping from declarations to constraint information. Note that
26171 both templates and their underlying declarations are mapped to the
26172 same constraint information.
26174 FIXME: This is defined in pt.c because garbage collection
26175 code is not being generated for constraint.cc. */
26179 /* Returns the template constraints of declaration T. If T is not
26180 constrained, return NULL_TREE. Note that T must be non-null. */
26182 tree
26184 {
26195 else
26197 }
26199 /* Associate the given constraint information CI with the declaration
26200 T. If T is a template, then the constraints are associated with
26201 its underlying declaration. Don't build associations if CI is
26202 NULL_TREE. */
26204 void
26206 {
26218 }
26220 /* Remove the associated constraints of the declaration T. */
26222 void
26224 {
26233 }
26235 /* Memoized satisfaction results for declarations. This
26236 maps the pair (constraint_info, arguments) to the result computed
26237 by constraints_satisfied_p. */
26240 {
26241 tree ci;
26242 tree args;
26243 tree result;
26244 };
26246 /* Hashing function and equality for constraint entries. */
26249 {
26251 {
26254 }
26257 {
26259 }
26260 };
26262 /* Memoized satisfaction results for concept checks. */
26265 {
26266 tree tmpl;
26267 tree args;
26268 tree result;
26269 };
26271 /* Hashing function and equality for constraint entries. */
26274 {
26276 {
26278 }
26281 {
26286 }
26287 };
26292 /* Search for a memoized satisfaction result. Returns one of the
26293 truth value nodes if previously memoized, or NULL_TREE otherwise. */
26295 tree
26297 {
26302 else
26304 }
26306 /* Memoize the result of a satisfication test. Returns the saved result. */
26308 tree
26310 {
26317 }
26319 /* Search for a memoized satisfaction result for a concept. */
26321 tree
26323 {
26328 else
26330 }
26332 /* Memoize the result of a concept check. Returns the saved result. */
26334 tree
26336 {
26343 }
26347 /* Returns a prior concept specialization. This returns the substituted
26348 and normalized constraints defined by the concept. */
26350 tree
26352 {
26357 else
26359 }
26361 /* Save a concept expansion for later. */
26363 tree
26365 {
26372 }
26374 static hashval_t
26376 {
26385 }
26387 /* Compare the constraints of two subsumption entries. The LEFT1 and
26388 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26389 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26391 static bool
26393 {
26401 }
26403 /* Key/value pair for learning and memoizing subsumption results. This
26404 associates a pair of check constraints (including arguments) with
26405 a boolean value indicating the result. */
26408 {
26409 tree t1;
26410 tree t2;
26412 };
26414 /* Hashing function and equality for constraint entries. */
26417 {
26419 {
26421 }
26424 {
26429 }
26430 };
26434 /* Search for a previously cached subsumption result. */
26438 {
26443 else
26445 }
26447 /* Save a subsumption result. */
26449 bool
26451 {
26458 }
26460 /* Set up the hash table for constraint association. */
26462 void
26464 {
26473 }
26475 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26476 0..N-1. */
26478 void
26480 {
26483 integer_type_node,
26484 NULL_TREE),
26488 }
26490 /* Set up the hash tables for template instantiations. */
26492 void
26494 {
26500 }
26502 /* Print stats about the template hash tables for -fstats. */
26504 void
26506 {
26515 }