| blob | 99f5b123a84ef0e6a266d55ce7b482d66e999b39 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2017 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
44 /* The type of functions taking a tree, and some additional data, and
45 returning an int. */
48 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
49 instantiations have been deferred, either because their definitions
50 were not yet available, or because we were putting off doing the work. */
54 };
69 /* Live only within one (recursive) call to tsubst_expr. We use
70 this to pass the statement expression node from the STMT_EXPR
71 to the EXPR_STMT that is its result. */
74 // -------------------------------------------------------------------------- //
75 // Local Specialization Stack
76 //
77 // Implementation of the RAII helper for creating new local
78 // specializations.
81 {
83 }
86 {
89 }
91 /* True if we've recursed into fn_type_unification too many times. */
95 {
96 tree tmpl;
97 tree args;
98 tree spec;
99 };
102 {
105 };
111 /* Contains canonical template parameter types. The vector is indexed by
112 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
113 TREE_LIST, whose TREE_VALUEs contain the canonical template
114 parameters of various types and levels. */
117 #define UNIFY_ALLOW_NONE 0
118 #define UNIFY_ALLOW_MORE_CV_QUAL 1
119 #define UNIFY_ALLOW_LESS_CV_QUAL 2
120 #define UNIFY_ALLOW_DERIVED 4
121 #define UNIFY_ALLOW_INTEGER 8
122 #define UNIFY_ALLOW_OUTER_LEVEL 16
123 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
124 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
127 tbr_incomplete_type,
128 tbr_ambiguous_baseclass,
129 tbr_success
130 };
153 tree);
210 location_t);
220 /* Make the current scope suitable for access checking when we are
221 processing T. T can be FUNCTION_DECL for instantiated function
222 template, VAR_DECL for static member variable, or TYPE_DECL for
223 alias template (needed by instantiate_decl). */
225 static void
227 {
235 else
239 {
240 saved_access_scope = tree_cons
243 }
244 }
246 /* Restore the scope set up by push_access_scope. T is the node we
247 are processing. */
249 static void
251 {
253 {
256 }
260 else
262 }
264 /* Do any processing required when DECL (a member template
265 declaration) is finished. Returns the TEMPLATE_DECL corresponding
266 to DECL, unless it is a specialization, in which case the DECL
267 itself is returned. */
269 tree
271 {
278 {
279 tree type;
287 {
291 }
293 }
297 {
299 {
302 }
303 else
305 }
306 else
310 }
312 /* Create a template info node. */
314 tree
316 {
321 }
323 /* Return the template info node corresponding to T, whatever T is. */
325 tree
327 {
349 }
351 /* Returns the template nesting level of the indicated class TYPE.
353 For example, in:
354 template <class T>
355 struct A
356 {
357 template <class U>
358 struct B {};
359 };
361 A<T>::B<U> has depth two, while A<T> has depth one.
362 Both A<T>::B<int> and A<int>::B<U> have depth one, if
363 they are instantiations, not specializations.
365 This function is guaranteed to return 0 if passed NULL_TREE so
366 that, for example, `template_class_depth (current_class_type)' is
367 always safe. */
369 int
371 {
375 {
386 else
388 }
391 }
393 /* Subroutine of maybe_begin_member_template_processing.
394 Returns true if processing DECL needs us to push template parms. */
396 static bool
398 {
404 }
406 /* Subroutine of maybe_begin_member_template_processing.
407 Push the template parms in PARMS, starting from LEVELS steps into the
408 chain, and ending at the beginning, since template parms are listed
409 innermost first. */
411 static void
413 {
421 current_template_parms
427 NULL);
429 {
438 {
445 /* Push the CONST_DECL. */
451 }
452 }
453 }
455 /* Restore the template parameter context for a member template, a
456 friend template defined in a class definition, or a non-template
457 member of template class. */
459 void
461 {
462 tree parms;
467 {
470 /* Disregard full specializations (c++/60999). */
473 }
476 {
481 {
484 }
487 }
489 /* Remember how many levels of template parameters we pushed so that
490 we can pop them later. */
492 }
494 /* Undo the effects of maybe_begin_member_template_processing. */
496 void
498 {
507 {
511 }
512 }
514 /* Return a new template argument vector which contains all of ARGS,
515 but has as its innermost set of arguments the EXTRA_ARGS. */
517 static tree
519 {
520 tree new_args;
538 }
540 /* Like add_to_template_args, but only the outermost ARGS are added to
541 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
542 (EXTRA_ARGS) levels are added. This function is used to combine
543 the template arguments from a partial instantiation with the
544 template arguments used to attain the full instantiation from the
545 partial instantiation. */
547 static tree
549 {
550 tree new_args;
552 /* If there are more levels of EXTRA_ARGS than there are ARGS,
553 something very fishy is going on. */
556 /* If *all* the new arguments will be the EXTRA_ARGS, just return
557 them. */
561 /* For the moment, we make ARGS look like it contains fewer levels. */
566 /* Now, we restore ARGS to its full dimensions. */
570 }
572 /* Return the N levels of innermost template arguments from the ARGS. */
574 tree
576 {
577 tree new_args;
583 /* If N is 1, just return the innermost set of template arguments. */
587 /* If we're not removing anything, just return the arguments we were
588 given. */
594 /* Make a new set of arguments, not containing the outer arguments. */
601 }
603 /* The inverse of get_innermost_template_args: Return all but the innermost
604 EXTRA_LEVELS levels of template arguments from the ARGS. */
606 static tree
608 {
609 tree new_args;
615 /* If N is 1, just return the outermost set of template arguments. */
619 /* If we're not removing anything, just return the arguments we were
620 given. */
625 /* Make a new set of arguments, not containing the inner arguments. */
632 }
634 /* We've got a template header coming up; push to a new level for storing
635 the parms. */
637 void
639 {
640 /* We use a non-tag-transparent scope here, which causes pushtag to
641 put tags in this scope, rather than in the enclosing class or
642 namespace scope. This is the right thing, since we want
643 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
644 global template class, push_template_decl handles putting the
645 TEMPLATE_DECL into top-level scope. For a nested template class,
646 e.g.:
648 template <class T> struct S1 {
649 template <class T> struct S2 {};
650 };
652 pushtag contains special code to insert the TEMPLATE_DECL for S2
653 at the right scope. */
659 /* Add a dummy parameter level while we process the parameter list. */
660 current_template_parms
663 current_template_parms);
664 }
666 /* This routine is called when a specialization is declared. If it is
667 invalid to declare a specialization here, an error is reported and
668 false is returned, otherwise this routine will return true. */
670 static bool
672 {
675 /* [temp.expl.spec]
677 An explicit specialization shall be declared in the namespace of
678 which the template is a member, or, for member templates, in the
679 namespace of which the enclosing class or enclosing class
680 template is a member. An explicit specialization of a member
681 function, member class or static data member of a class template
682 shall be declared in the namespace of which the class template
683 is a member. */
685 {
688 }
690 /* [temp.expl.spec]
692 In an explicit specialization declaration for a member of a class
693 template or a member template that appears in namespace scope,
694 the member template and some of its enclosing class templates may
695 remain unspecialized, except that the declaration shall not
696 explicitly specialize a class member template if its enclosing
697 class templates are not explicitly specialized as well. */
699 {
702 }
705 }
707 /* We've just seen template <>. */
709 bool
711 {
715 }
717 /* Called at then end of processing a declaration preceded by
718 template<>. */
720 void
722 {
725 }
727 /* Any template <>'s that we have seen thus far are not referring to a
728 function specialization. */
730 void
732 {
735 }
737 /* We've just seen a template header. If SPECIALIZATION is nonzero,
738 it was of the form template <>. */
740 static void
742 {
744 template_header_count++;
745 }
747 /* We're beginning an explicit instantiation. */
749 void
751 {
754 }
757 void
759 {
762 }
764 /* An explicit specialization or partial specialization of TMPL is being
765 declared. Check that the namespace in which the specialization is
766 occurring is permissible. Returns false iff it is invalid to
767 specialize TMPL in the current namespace. */
769 static bool
771 {
774 /* [tmpl.expl.spec]
776 An explicit specialization shall be declared in a namespace enclosing the
777 specialized template. An explicit specialization whose declarator-id is
778 not qualified shall be declared in the nearest enclosing namespace of the
779 template, or, if the namespace is inline (7.3.1), any namespace from its
780 enclosing namespace set. */
783 {
786 }
789 /* Same or enclosing namespace. */
791 else
792 {
798 }
799 }
801 /* SPEC is an explicit instantiation. Check that it is valid to
802 perform this explicit instantiation in the current namespace. */
804 static void
806 {
807 tree ns;
809 /* DR 275: An explicit instantiation shall appear in an enclosing
810 namespace of its template. */
816 }
818 // Returns the type of a template specialization only if that
819 // specialization needs to be defined. Otherwise (e.g., if the type has
820 // already been defined), the function returns NULL_TREE.
821 static tree
823 {
824 // An implicit instantiation of an incomplete type implies
825 // the definition of a new class template.
826 //
827 // template<typename T>
828 // struct S;
829 //
830 // template<typename T>
831 // struct S<T*>;
832 //
833 // Here, S<T*> is an implicit instantiation of S whose type
834 // is incomplete.
838 // It can also be the case that TYPE is a completed specialization.
839 // Continuing the previous example, suppose we also declare:
840 //
841 // template<typename T>
842 // requires Integral<T>
843 // struct S<T*>;
844 //
845 // Here, S<T*> refers to the specialization S<T*> defined
846 // above. However, we need to differentiate definitions because
847 // we intend to define a new partial specialization. In this case,
848 // we rely on the fact that the constraints are different for
849 // this declaration than that above.
850 //
851 // Note that we also get here for injected class names and
852 // late-parsed template definitions. We must ensure that we
853 // do not create new type declarations for those cases.
855 {
859 // If there are no template parameters, this cannot be a new
860 // partial template specializtion?
864 // The injected-class-name is not a new partial specialization.
868 // If the constraints are not the same as those of the primary
869 // then, we can probably create a new specialization.
873 {
877 }
879 // Also, if there's a pre-existing specialization with matching
880 // constraints, then this also isn't new.
883 {
891 }
893 // Create a new type node (and corresponding type decl)
894 // for the newly declared specialization.
899 /* We only need a separate type node for storing the definition of this
900 partial specialization; uses of S<T*> are unconstrained, so all are
901 equivalent. So keep TYPE_CANONICAL the same. */
904 // Build the corresponding type decl.
910 }
913 }
915 /* The TYPE is being declared. If it is a template type, that means it
916 is a partial specialization. Do appropriate error-checking. */
918 tree
920 {
921 tree context;
926 /* A lambda that appears in specialization context is not itself a
927 specialization. */
932 {
936 }
941 {
947 else
950 }
952 {
953 /* This is for ordinary explicit specialization and partial
954 specialization of a template class such as:
956 template <> class C<int>;
958 or:
960 template <class T> class C<T*>;
962 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
965 {
972 {
977 }
978 }
984 /* Trying to define a specialization either without a template<> header
985 or in an inappropriate place. We've already given an error, so just
986 bail now so we don't actually define the specialization. */
988 }
994 {
995 /* This is for an explicit specialization of member class
996 template according to [temp.expl.spec/18]:
998 template <> template <class U> class C<int>::D;
1000 The context `C<int>' must be an implicit instantiation.
1001 Otherwise this is just a member class template declared
1002 earlier like:
1004 template <> class C<int> { template <class U> class D; };
1005 template <> template <class U> class C<int>::D;
1007 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1008 while in the second case, `C<int>::D' is a primary template
1009 and `C<T>::D' may not exist. */
1013 {
1014 tree t;
1019 {
1024 }
1026 /* Check for invalid specialization after instantiation:
1028 template <> template <> class C<int>::D<int>;
1029 template <> template <class U> class C<int>::D; */
1033 {
1037 {
1038 /* We already have a full specialization of this partial
1039 instantiation, or a full specialization has been
1040 looked up but not instantiated. Reassign it to the
1041 new member specialization template. */
1042 spec_entry elt;
1054 spec_entry **slot
1059 }
1060 else
1061 /* But if we've had an implicit instantiation, that's a
1062 problem ([temp.expl.spec]/6). */
1065 }
1067 /* Mark TYPE as a specialization. And as a result, we only
1068 have one level of template argument for the innermost
1069 class template. */
1074 }
1075 }
1077 {
1078 /* Someday C++0x may allow for enum template specialization. */
1083 else
1084 {
1087 }
1088 }
1091 }
1093 /* Returns nonzero if we can optimize the retrieval of specializations
1094 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1095 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1099 {
1102 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1103 parameter. */
1105 /* The optimized lookup depends on the fact that the
1106 template arguments for the member function template apply
1107 purely to the containing class, which is not true if the
1108 containing class is an explicit or partial
1109 specialization. */
1113 /* It is possible to have a template that is not a member
1114 template and is not a member of a template class:
1116 template <typename T>
1117 struct S { friend A::f(); };
1119 Here, the friend function is a template, but the context does
1120 not have template information. The optimized lookup relies
1121 on having ARGS be the template arguments for both the class
1122 and the function template. */
1124 }
1126 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1127 gone through coerce_template_parms by now. */
1129 static void
1131 {
1134 {
1137 {
1144 /* Allow typedefs on the type of a non-type argument, since a
1146 else
1148 }
1149 }
1151 }
1153 /* Retrieve the specialization (in the sense of [temp.spec] - a
1154 specialization is either an instantiation or an explicit
1155 specialization) of TMPL for the given template ARGS. If there is
1156 no such specialization, return NULL_TREE. The ARGS are a vector of
1157 arguments, or a vector of vectors of arguments, in the case of
1158 templates with more than one level of parameters.
1160 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1161 then we search for a partial specialization matching ARGS. This
1162 parameter is ignored if TMPL is not a class template.
1164 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1165 result is a NONTYPE_ARGUMENT_PACK. */
1167 static tree
1169 {
1179 /* There should be as many levels of arguments as there are
1180 levels of parameters. */
1190 {
1191 /* The template arguments actually apply to the containing
1192 class. Find the class specialization with those
1193 arguments. */
1195 tree class_specialization
1199 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1200 for the specialization. */
1204 /* Iterate through the methods with the indicated name, looking
1205 for the one that has an instance of TMPL. */
1208 {
1211 /* using-declarations can add base methods to the method vec,
1212 and we don't want those here. */
1215 }
1217 }
1218 else
1219 {
1221 spec_entry elt;
1230 else
1238 }
1241 }
1243 /* Like retrieve_specialization, but for local declarations. */
1245 tree
1247 {
1253 }
1255 /* Returns nonzero iff DECL is a specialization of TMPL. */
1257 int
1259 {
1260 tree t;
1263 {
1269 }
1270 else
1271 {
1280 }
1283 }
1285 /* Returns nonzero iff DECL is a specialization of friend declaration
1286 FRIEND_DECL according to [temp.friend]. */
1288 bool
1290 {
1297 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1298 of a template class, we want to check if DECL is a specialization
1299 if this. */
1303 {
1304 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1307 }
1312 /* There is nothing to do if this is not a template friend. */
1319 /* [temp.friend/6]
1320 A member of a class template may be declared to be a friend of a
1321 non-template class. In this case, the corresponding member of
1322 every specialization of the class template is a friend of the
1323 class granting friendship.
1325 For example, given a template friend declaration
1327 template <class T> friend void A<T>::f();
1329 the member function below is considered a friend
1331 template <> struct A<int> {
1332 void f();
1333 };
1335 For this type of template friend, TEMPLATE_DEPTH below will be
1336 nonzero. To determine if DECL is a friend of FRIEND, we first
1337 check if the enclosing class is a specialization of another. */
1344 {
1345 /* Next, we check the members themselves. In order to handle
1346 a few tricky cases, such as when FRIEND_DECL's are
1348 template <class T> friend void A<T>::g(T t);
1349 template <class T> template <T t> friend void A<T>::h();
1351 and DECL's are
1353 void A<int>::g(int);
1354 template <int> void A<int>::h();
1356 we need to figure out ARGS, the template arguments from
1357 the context of DECL. This is required for template substitution
1358 of `T' in the function parameter of `g' and template parameter
1359 of `h' in the above examples. Here ARGS corresponds to `int'. */
1366 {
1368 {
1371 else
1373 current_depth++;
1374 }
1376 }
1379 {
1381 tree friend_type;
1382 tree decl_type;
1383 tree friend_args_type;
1384 tree decl_args_type;
1386 /* Make sure that both DECL and FRIEND_DECL are templates or
1387 non-templates. */
1393 {
1394 /* If both are templates, check template parameter list. */
1395 tree friend_parms
1400 friend_parms))
1404 }
1405 else
1413 /* Check if return types match. */
1417 /* Check if function parameter types match, ignoring the
1418 `this' parameter. */
1427 }
1428 else
1429 {
1430 /* DECL is a TYPE_DECL */
1434 /* Make sure that both DECL and FRIEND_DECL are templates or
1435 non-templates. */
1436 is_template
1443 {
1444 tree friend_parms;
1445 /* If both are templates, check the name of the two
1446 TEMPLATE_DECL's first because is_friend didn't. */
1451 /* Now check template parameter list. */
1452 friend_parms
1455 return comp_template_parms
1457 friend_parms);
1458 }
1459 else
1462 }
1463 }
1465 }
1467 /* Register the specialization SPEC as a specialization of TMPL with
1468 the indicated ARGS. IS_FRIEND indicates whether the specialization
1469 is actually just a friend declaration. Returns SPEC, or an
1470 equivalent prior declaration, if available.
1472 We also store instantiations of field packs in the hash table, even
1473 though they are not themselves templates, to make lookup easier. */
1475 static tree
1477 hashval_t hash)
1478 {
1479 tree fn;
1481 spec_entry elt;
1489 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1490 register it; we want the corresponding TEMPLATE_DECL instead.
1491 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1492 the more obvious `uses_template_parms (spec)' to avoid problems
1493 with default function arguments. In particular, given
1494 something like this:
1496 template <class T> void f(T t1, T t = T())
1498 the default argument expression is not substituted for in an
1499 instantiation unless and until it is actually needed. */
1503 /* We don't put these specializations in the hash table, but we might
1504 want to give an error about a mismatch. */
1506 else
1507 {
1515 slot =
1519 else
1521 }
1523 /* We can sometimes try to re-register a specialization that we've
1524 already got. In particular, regenerate_decl_from_template calls
1525 duplicate_decls which will update the specialization list. But,
1526 we'll still get called again here anyhow. It's more convenient
1527 to simply allow this than to try to prevent it. */
1531 {
1533 {
1536 {
1538 fn);
1540 }
1541 else
1542 {
1543 tree clone;
1544 /* This situation should occur only if the first
1545 specialization is an implicit instantiation, the
1546 second is an explicit specialization, and the
1547 implicit instantiation has not yet been used. That
1548 situation can occur if we have implicitly
1549 instantiated a member function and then specialized
1550 it later.
1552 We can also wind up here if a friend declaration that
1553 looked like an instantiation turns out to be a
1554 specialization:
1556 template <class T> void foo(T);
1557 class S { friend void foo<>(int) };
1558 template <> void foo(int);
1560 We transform the existing DECL in place so that any
1561 pointers to it become pointers to the updated
1562 declaration.
1564 If there was a definition for the template, but not
1565 for the specialization, we want this to look as if
1566 there were no definition, and vice versa. */
1569 /* The call to duplicate_decls will have applied
1570 [temp.expl.spec]:
1572 An explicit specialization of a function template
1573 is inline only if it is explicitly declared to be,
1574 and independently of whether its function template
1575 is.
1577 to the primary function; now copy the inline bits to
1578 the various clones. */
1580 {
1587 }
1591 }
1592 }
1594 {
1597 /* We've already complained in duplicate_decls. */
1601 /* Dup decl failed, but this is a new definition. Set the
1602 line number so any errors match this new
1603 definition. */
1607 }
1608 }
1612 /* A specialization must be declared in the same namespace as the
1613 template it is specializing. */
1619 {
1628 /* If TMPL is a forward declaration of a template function, keep a list
1629 of all specializations in case we need to reassign them to a friend
1630 template later in tsubst_friend_function.
1632 Also keep a list of all variable template instantiations so that
1633 process_partial_specialization can check whether a later partial
1634 specialization would have used it. */
1637 }
1640 }
1642 /* Returns true iff two spec_entry nodes are equivalent. */
1646 bool
1648 {
1655 /* tmpl could be a FIELD_DECL for a capture pack. */
1659 {
1660 /* Partial specializations of a variable template can be distinguished by
1661 constraints. */
1665 }
1669 }
1671 /* Returns a hash for a template TMPL and template arguments ARGS. */
1673 static hashval_t
1675 {
1678 }
1680 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1681 ignoring SPEC. */
1683 hashval_t
1685 {
1687 }
1689 /* Recursively calculate a hash value for a template argument ARG, for use
1690 in the hash tables of template specializations. */
1692 hashval_t
1694 {
1714 {
1722 {
1727 }
1749 {
1753 {
1756 }
1758 }
1762 {
1765 }
1776 val = iterative_hash_template_arg
1788 val);
1790 val);
1799 /* A lambda can't appear in a template arg, but don't crash on
1800 erroneous input. */
1812 /* Now hash operands as usual. */
1817 }
1820 {
1823 {
1824 // We want an alias specialization that survived strip_typedefs
1825 // to hash differently from its TYPE_CANONICAL, to avoid hash
1826 // collisions that compare as different in template_args_equal.
1827 // These could be dependent specializations that strip_typedefs
1828 // left alone, or untouched specializations because
1829 // coerce_template_parms returns the unconverted template
1830 // arguments if it sees incomplete argument packs.
1833 }
1836 val);
1839 /* Otherwise just compare the types during lookup. */
1848 {
1853 }
1854 }
1857 }
1859 /* Unregister the specialization SPEC as a specialization of TMPL.
1860 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1861 if the SPEC was listed as a specialization of TMPL.
1863 Note that SPEC has been ggc_freed, so we can't look inside it. */
1865 bool
1867 {
1869 spec_entry elt;
1877 {
1882 }
1885 }
1887 /* Like register_specialization, but for local declarations. We are
1888 registering SPEC, an instantiation of TMPL. */
1890 void
1892 {
1894 }
1896 /* TYPE is a class type. Returns true if TYPE is an explicitly
1897 specialized class. */
1899 bool
1901 {
1905 }
1907 /* Print the list of functions at FNS, going through all the overloads
1908 for each element of the list. Alternatively, FNS can not be a
1909 TREE_LIST, in which case it will be printed together with all the
1910 overloads.
1912 MORE and *STR should respectively be FALSE and NULL when the function
1913 is called from the outside. They are used internally on recursive
1914 calls. print_candidates manages the two parameters and leaves NULL
1915 in *STR when it ends. */
1917 static void
1919 {
1923 else
1925 {
1931 {
1934 else
1937 }
1939 }
1940 }
1942 /* Print the list of candidate FNS in an error message. FNS can also
1943 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1945 void
1947 {
1951 }
1953 /* Get a (possibly) constrained template declaration for the
1954 purpose of ordering candidates. */
1955 static tree
1957 {
1963 }
1965 /* Among candidates having the same signature, return the
1966 most constrained or NULL_TREE if there is no best candidate.
1967 If the signatures of candidates vary (e.g., template
1968 specialization vs. member function), then there can be no
1969 most constrained.
1971 Note that we don't compare constraints on the functions
1972 themselves, but rather those of their templates. */
1973 static tree
1975 {
1976 // Try to find the best candidate in a first pass.
1979 {
1986 }
1988 // Verify that the champ is better than previous candidates.
1993 }
1996 }
1999 /* Returns the template (one of the functions given by TEMPLATE_ID)
2000 which can be specialized to match the indicated DECL with the
2001 explicit template args given in TEMPLATE_ID. The DECL may be
2002 NULL_TREE if none is available. In that case, the functions in
2003 TEMPLATE_ID are non-members.
2005 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2006 specialization of a member template.
2008 The TEMPLATE_COUNT is the number of references to qualifying
2009 template classes that appeared in the name of the function. See
2010 check_explicit_specialization for a more accurate description.
2012 TSK indicates what kind of template declaration (if any) is being
2013 declared. TSK_TEMPLATE indicates that the declaration given by
2014 DECL, though a FUNCTION_DECL, has template parameters, and is
2015 therefore a template function.
2017 The template args (those explicitly specified and those deduced)
2018 are output in a newly created vector *TARGS_OUT.
2020 If it is impossible to determine the result, an error message is
2021 issued. The error_mark_node is returned to indicate failure. */
2023 static tree
2025 tree decl,
2029 tmpl_spec_kind tsk)
2030 {
2031 tree fns;
2032 tree targs;
2033 tree explicit_targs;
2036 /* A TREE_LIST of templates of which DECL may be a specialization.
2037 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2038 corresponding TREE_PURPOSE is the set of template arguments that,
2039 when used to instantiate the template, would produce a function
2040 with the signature of DECL. */
2050 /* We shouldn't be specializing a member template of an
2051 unspecialized class template; we already gave an error in
2052 check_specialization_scope, now avoid crashing. */
2055 {
2058 }
2066 /* Check for baselinks. */
2071 {
2074 }
2076 {
2079 }
2081 /* Count the number of template headers specified for this
2082 specialization. */
2092 {
2095 tf_warning_or_error,
2099 }
2101 {
2105 {
2106 tree decl_arg_types;
2107 tree fn_arg_types;
2108 tree insttype;
2110 /* In case of explicit specialization, we need to check if
2111 the number of template headers appearing in the specialization
2112 is correct. This is usually done in check_explicit_specialization,
2113 but the check done there cannot be exhaustive when specializing
2114 member functions. Consider the following code:
2116 template <> void A<int>::f(int);
2117 template <> template <> void A<int>::f(int);
2119 Assuming that A<int> is not itself an explicit specialization
2120 already, the first line specializes "f" which is a non-template
2121 member function, whilst the second line specializes "f" which
2122 is a template member function. So both lines are syntactically
2123 correct, and check_explicit_specialization does not reject
2124 them.
2126 Here, we can do better, as we are matching the specialization
2127 against the declarations. We count the number of template
2128 headers, and we check if they match TEMPLATE_COUNT + 1
2129 (TEMPLATE_COUNT is the number of qualifying template classes,
2130 plus there must be another header for the member template
2131 itself).
2133 Notice that if header_count is zero, this is not a
2134 specialization but rather a template instantiation, so there
2135 is no check we can perform here. */
2139 /* Check that the number of template arguments at the
2140 innermost level for DECL is the same as for FN. */
2148 /* DECL might be a specialization of FN. */
2152 /* For a non-static member function, we need to make sure
2153 that the const qualification is the same. Since
2154 get_bindings does not try to merge the "this" parameter,
2155 we must do the comparison explicitly. */
2161 /* Skip the "this" parameter and, for constructors of
2162 classes with virtual bases, the VTT parameter. A
2163 full specialization of a constructor will have a VTT
2164 parameter, but a template never will. */
2165 decl_arg_types
2167 fn_arg_types
2170 /* Function templates cannot be specializations; there are
2171 no partial specializations of functions. Therefore, if
2172 the type of DECL does not match FN, there is no
2173 match.
2175 Note that it should never be the case that we have both
2176 candidates added here, and for regular member functions
2177 below. */
2179 {
2183 }
2185 /* See whether this function might be a specialization of this
2186 template. Suppress access control because we might be trying
2187 to make this specialization a friend, and we have already done
2188 access control for the declaration of the specialization. */
2194 /* We cannot deduce template arguments that when used to
2195 specialize TMPL will produce DECL. */
2198 /* Remove, from the set of candidates, all those functions
2199 whose constraints are not satisfied. */
2203 // Then, try to form the new function type.
2207 fn_arg_types
2212 /* Save this template, and the arguments deduced. */
2214 }
2216 /* FN is an ordinary member function, and we need a
2217 specialization of a member template. */
2218 ;
2220 /* We can get IDENTIFIER_NODEs here in certain erroneous
2221 cases. */
2222 ;
2224 /* This is just an ordinary non-member function. Nothing can
2225 be a specialization of that. */
2226 ;
2228 /* Cannot specialize functions that are created implicitly. */
2229 ;
2230 else
2231 {
2232 tree decl_arg_types;
2234 /* This is an ordinary member function. However, since
2235 we're here, we can assume its enclosing class is a
2236 template class. For example,
2238 template <typename T> struct S { void f(); };
2239 template <> void S<int>::f() {}
2241 Here, S<int>::f is a non-template, but S<int> is a
2242 template class. If FN has the same type as DECL, we
2243 might be in business. */
2246 /* Its enclosing class is an explicit specialization
2247 of a template class. This is not a candidate. */
2252 /* The return types differ. */
2255 /* Adjust the type of DECL in case FN is a static member. */
2262 decl_arg_types))
2265 // If the deduced arguments do not satisfy the constraints,
2266 // this is not a candidate.
2270 // Add the candidate.
2272 }
2273 }
2276 {
2277 /* We have:
2279 [temp.expl.spec]
2281 It is possible for a specialization with a given function
2282 signature to be instantiated from more than one function
2283 template. In such cases, explicit specification of the
2284 template arguments must be used to uniquely identify the
2285 function template specialization being specialized.
2287 Note that here, there's no suggestion that we're supposed to
2288 determine which of the candidate templates is most
2289 specialized. However, we, also have:
2291 [temp.func.order]
2293 Partial ordering of overloaded function template
2294 declarations is used in the following contexts to select
2295 the function template to which a function template
2296 specialization refers:
2298 -- when an explicit specialization refers to a function
2299 template.
2301 So, we do use the partial ordering rules, at least for now.
2302 This extension can only serve to make invalid programs valid,
2303 so it's safe. And, there is strong anecdotal evidence that
2304 the committee intended the partial ordering rules to apply;
2305 the EDG front end has that behavior, and John Spicer claims
2306 that the committee simply forgot to delete the wording in
2307 [temp.expl.spec]. */
2310 {
2313 }
2314 }
2316 // Concepts allows multiple declarations of member functions
2317 // with the same signature. Like above, we need to rely on
2318 // on the partial ordering of those candidates to determine which
2319 // is the best.
2321 {
2323 {
2326 }
2327 }
2330 {
2337 else
2340 }
2344 {
2350 }
2352 /* We have one, and exactly one, match. */
2354 {
2358 // Propagate the candidate's constraints to the declaration.
2361 /* DECL is a re-declaration or partial instantiation of a template
2362 function. */
2365 /* It was a specialization of an ordinary member function in a
2366 template class. */
2368 }
2370 /* It was a specialization of a template. */
2373 {
2378 }
2379 else
2382 }
2384 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2385 but with the default argument values filled in from those in the
2386 TMPL_TYPES. */
2388 static tree
2390 tree tmpl_types)
2391 {
2392 tree new_spec_types;
2400 /* Substitute into the rest of the list. */
2401 new_spec_types =
2405 /* Add the default argument for this parameter. */
2408 new_spec_types);
2409 }
2411 /* DECL is an explicit specialization. Replicate default arguments
2412 from the template it specializes. (That way, code like:
2414 template <class T> void f(T = 3);
2415 template <> void f(double);
2416 void g () { f (); }
2418 works, as required.) An alternative approach would be to look up
2419 the correct default arguments at the call-site, but this approach
2420 is consistent with how implicit instantiations are handled. */
2422 static void
2424 {
2425 tree tmpl;
2426 tree spec_types;
2427 tree tmpl_types;
2428 tree new_spec_types;
2429 tree old_type;
2430 tree new_type;
2431 tree t;
2436 /* See if there's anything we need to do. */
2449 {
2450 /* Remove the this pointer, but remember the object's type for
2451 CV quals. */
2457 {
2458 /* DECL may contain more parameters than TMPL due to the extra
2459 in-charge parameter in constructors and destructors. */
2462 }
2464 {
2467 }
2468 }
2470 /* Compute the merged default arguments. */
2471 new_spec_types =
2474 /* Compute the new FUNCTION_TYPE. */
2476 {
2480 new_spec_types);
2483 /* Put the in-charge parameter back. */
2486 new_spec_types);
2490 new_spec_types);
2491 }
2492 else
2494 new_spec_types);
2504 }
2506 /* Return the number of template headers we expect to see for a definition
2507 or specialization of CTYPE or one of its non-template members. */
2509 int
2511 {
2515 {
2516 /* You're supposed to have one `template <...>' for every
2517 template class, but you don't need one for a full
2518 specialization. For example:
2520 template <class T> struct S{};
2521 template <> struct S<int> { void f(); };
2522 void S<int>::f () {}
2524 is correct; there shouldn't be a `template <>' for the
2525 definition of `S<int>::f'. */
2527 /* If CTYPE does not have template information of any
2528 kind, then it is not a template, nor is it nested
2529 within a template. */
2537 }
2540 }
2542 /* Do a simple sanity check on the template headers that precede the
2543 variable declaration DECL. */
2545 void
2547 {
2552 {
2555 "variable templates only available with "
2558 // Namespace-scope variable templates should have a template header.
2560 }
2562 {
2564 "too many template headers for %qD "
2570 "members of an explicitly specialized class are defined "
2572 }
2573 }
2575 /* An explicit specialization whose declarator-id or class-head-name is not
2576 qualified shall be declared in the nearest enclosing namespace of the
2577 template, or, if the namespace is inline (7.3.1), any namespace from its
2578 enclosing namespace set.
2580 If the name declared in the explicit instantiation is an unqualified name,
2581 the explicit instantiation shall appear in the namespace where its template
2582 is declared or, if that namespace is inline (7.3.1), any namespace from its
2583 enclosing namespace set. */
2585 void
2587 {
2592 {
2598 /* This was allowed in C++98, so only pedwarn. */
2600 "outside its namespace must use a nested-name-"
2602 }
2603 }
2605 /* Check to see if the function just declared, as indicated in
2606 DECLARATOR, and in DECL, is a specialization of a function
2607 template. We may also discover that the declaration is an explicit
2608 instantiation at this point.
2610 Returns DECL, or an equivalent declaration that should be used
2611 instead if all goes well. Issues an error message if something is
2612 amiss. Returns error_mark_node if the error is not easily
2613 recoverable.
2615 FLAGS is a bitmask consisting of the following flags:
2617 2: The function has a definition.
2618 4: The function is a friend.
2620 The TEMPLATE_COUNT is the number of references to qualifying
2621 template classes that appeared in the name of the function. For
2622 example, in
2624 template <class T> struct S { void f(); };
2625 void S<int>::f();
2627 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2628 classes are not counted in the TEMPLATE_COUNT, so that in
2630 template <class T> struct S {};
2631 template <> struct S<int> { void f(); }
2632 template <> void S<int>::f();
2634 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2635 invalid; there should be no template <>.)
2637 If the function is a specialization, it is marked as such via
2638 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2639 is set up correctly, and it is added to the list of specializations
2640 for that template. */
2642 tree
2644 tree decl,
2647 {
2656 tmpl_spec_kind tsk;
2659 {
2662 else
2664 }
2665 else
2669 {
2672 {
2675 }
2677 {
2679 /* This could be something like:
2681 template <class T> void f(T);
2682 class S { friend void f<>(int); } */
2684 else
2685 {
2686 /* This case handles bogus declarations like template <>
2687 template <class T> void f<int>(); */
2690 declarator);
2692 }
2693 }
2697 /* The error has already been reported in
2698 check_specialization_scope. */
2704 /* Fall through. */
2717 decl);
2720 else
2724 /* Fall through. */
2730 /* In cases like template<> constexpr bool v = true;
2731 We'll give an error in check_template_variable. */
2737 else
2743 {
2744 /* This case handles bogus declarations like template <>
2745 template <class T> void f<int>(); */
2749 declarator);
2751 {
2752 /* Partial specialization of variable template. */
2756 }
2760 else
2764 ok:;
2765 }
2768 /* This is a specialization of a member template, without
2769 specialization the containing class. Something like:
2771 template <class T> struct S {
2772 template <class U> void f (U);
2773 };
2774 template <> template <class U> void S<int>::f(U) {}
2776 That's a specialization -- but of the entire template. */
2782 }
2785 /* This doesn't apply to variable templates. */
2788 {
2792 {
2796 }
2797 }
2800 {
2805 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2807 {
2808 tree fns;
2813 else
2814 {
2815 /* If there is no class context, the explicit instantiation
2816 must be at namespace scope. */
2819 /* Find the namespace binding, using the declaration
2820 context. */
2824 /* If lookup fails, look for a friend declaration so we can
2825 give a better diagnostic. */
2831 {
2834 }
2835 }
2838 }
2844 {
2846 /* A specialization in class scope. This is invalid,
2847 but the error will already have been flagged by
2848 check_specialization_scope. */
2850 else
2851 {
2852 /* It's not valid to write an explicit instantiation in
2853 class scope, e.g.:
2855 class C { template void f(); }
2857 This case is caught by the parser. However, on
2858 something like:
2860 template class C { void f(); };
2862 (which is invalid) we can get here. The error will be
2863 issued later. */
2864 ;
2865 }
2868 }
2871 {
2872 // We'll match variable templates in start_decl.
2876 /* Find the list of functions in ctype that have the same
2877 name as the declared function. */
2883 {
2888 {
2889 /* From [temp.expl.spec]:
2891 If such an explicit specialization for the member
2892 of a class template names an implicitly-declared
2893 special member function (clause _special_), the
2894 program is ill-formed.
2896 Similar language is found in [temp.explicit]. */
2899 }
2902 }
2905 {
2909 }
2910 else
2911 {
2913 tree ovl;
2915 /* For a type-conversion operator, we cannot do a
2916 name-based lookup. We might be looking for `operator
2917 int' which will be a specialization of `operator T'.
2918 So, we find *all* the conversion operators, and then
2919 select from them. */
2927 {
2929 /* There are no more conversion functions. */
2932 /* Glue all these conversion functions together
2933 with those we already have. */
2935 }
2936 }
2939 {
2942 }
2943 else
2945 }
2947 /* Figure out what exactly is being specialized at this point.
2948 Note that for an explicit instantiation, even one for a
2949 member function, we cannot tell a priori whether the
2950 instantiation is for a member template, or just a member
2951 function of a template class. Even if a member template is
2952 being instantiated, the member template arguments may be
2953 elided if they can be deduced from the rest of the
2954 declaration. */
2957 member_specialization,
2958 template_count,
2959 tsk);
2962 /* We couldn't figure out what this declaration was
2963 specializing. */
2965 else
2966 {
2969 {
2971 "friend declaration %qD is not visible to "
2975 }
2983 {
2984 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2985 is done by do_decl_instantiation later. */
2991 {
2992 /* If TMPL is not the most general template (for
2993 example, if TMPL is a friend template that is
2994 injected into namespace scope), then there will
2995 be too many levels of TARGS. Remove some of them
2996 here. */
2998 tree new_targs;
3005 }
3008 }
3010 /* If we thought that the DECL was a member function, but it
3011 turns out to be specializing a static member function,
3012 make DECL a static member function as well. */
3018 /* If this is a specialization of a member template of a
3019 template class, we want to return the TEMPLATE_DECL, not
3020 the specialization of it. */
3022 {
3027 {
3028 tree parm;
3032 /* We want to use the argument list specified in the
3033 definition, not in the original declaration. */
3038 }
3041 }
3043 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3049 /* Inherit default function arguments from the template
3050 DECL is specializing. */
3054 /* This specialization has the same protection as the
3055 template it specializes. */
3059 /* 7.1.1-1 [dcl.stc]
3061 A storage-class-specifier shall not be specified in an
3062 explicit specialization...
3064 The parser rejects these, so unless action is taken here,
3065 explicit function specializations will always appear with
3066 global linkage.
3068 The action recommended by the C++ CWG in response to C++
3069 defect report 605 is to make the storage class and linkage
3070 of the explicit specialization match the templated function:
3072 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3073 */
3075 {
3079 /* A concept cannot be specialized. */
3081 {
3083 gen_tmpl);
3085 }
3087 /* This specialization has the same linkage and visibility as
3088 the function template it specializes. */
3091 {
3094 }
3097 {
3100 }
3101 }
3103 /* If DECL is a friend declaration, declared using an
3104 unqualified name, the namespace associated with DECL may
3105 have been set incorrectly. For example, in:
3107 template <typename T> void f(T);
3108 namespace N {
3109 struct S { friend void f<int>(int); }
3110 }
3112 we will have set the DECL_CONTEXT for the friend
3113 declaration to N, rather than to the global namespace. */
3118 /* This is not really a declaration of a specialization.
3119 It's just the name of an instantiation. But, it's not
3120 a request for an instantiation, either. */
3123 /* A specialization is not necessarily COMDAT. */
3129 /* If this is a full specialization, register it so that we can find
3130 it again. Partial specializations will be registered in
3131 process_partial_specialization. */
3136 /* A 'structor should already have clones. */
3142 }
3143 }
3146 }
3148 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3149 parameters. These are represented in the same format used for
3150 DECL_TEMPLATE_PARMS. */
3152 int
3154 {
3155 const_tree p1;
3156 const_tree p2;
3164 {
3176 {
3180 /* If either of the template parameters are invalid, assume
3181 they match for the sake of error recovery. */
3194 }
3195 }
3198 /* One set of parameters has more parameters lists than the
3199 other. */
3203 }
3205 /* Determine whether PARM is a parameter pack. */
3207 bool
3209 {
3210 /* Determine if we have a non-type template parameter pack. */
3217 /* If this is a list of template parameters, we could get a
3218 TYPE_DECL or a TEMPLATE_DECL. */
3222 /* Otherwise it must be a type template parameter. */
3226 }
3228 /* Determine if T is a function parameter pack. */
3230 bool
3232 {
3236 }
3238 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3239 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3241 tree
3243 {
3250 }
3252 /* Return true iff the function parameter PARAM_DECL was expanded
3253 from the function parameter pack PACK. */
3255 bool
3257 {
3262 /* The parameter pack and its pack arguments have the same
3263 DECL_PARM_INDEX. */
3265 }
3267 /* Determine whether ARGS describes a variadic template args list,
3268 i.e., one that is terminated by a template argument pack. */
3270 static bool
3272 {
3274 tree last_parm;
3288 }
3290 /* Generate a new name for the parameter pack name NAME (an
3291 IDENTIFIER_NODE) that incorporates its */
3293 static tree
3295 {
3296 /* Munge the name to include the parameter index. */
3297 #define NUMBUF_LEN 128
3311 }
3313 /* Return true if T is a primary function, class or alias template
3314 instantiation. */
3316 bool
3318 {
3332 }
3334 /* Return true if PARM is a template template parameter. */
3336 bool
3338 {
3340 }
3342 /* Return true iff PARM is a DECL representing a type template
3343 parameter. */
3345 bool
3347 {
3352 }
3354 /* Return the template parameters of T if T is a
3355 primary template instantiation, NULL otherwise. */
3357 tree
3359 {
3364 parms = INNERMOST_TEMPLATE_PARMS
3368 }
3370 /* Return the template parameters of the LEVELth level from the full list
3371 of template parameters PARMS. */
3373 tree
3375 {
3376 tree p;
3387 }
3389 /* Returns the template arguments of T if T is a template instantiation,
3390 NULL otherwise. */
3392 tree
3394 {
3402 }
3404 /* Return the argument pack elements of T if T is a template argument pack,
3405 NULL otherwise. */
3407 tree
3409 {
3415 }
3417 /* True iff FN is a function representing a built-in variadic parameter
3418 pack. */
3420 bool
3422 {
3432 }
3434 /* True iff CALL is a call to a function representing a built-in variadic
3435 parameter pack. */
3437 static bool
3439 {
3443 }
3445 /* Return a TREE_VEC for the expansion of __integer_pack(HI). */
3447 static tree
3449 tree in_decl)
3450 {
3456 {
3458 {
3461 }
3466 }
3467 else
3468 {
3472 /* Calculate the largest value of len that won't make the size of the vec
3473 overflow an int. The compiler will exceed resource limits long before
3474 this, but it seems a decent place to diagnose. */
3478 {
3483 }
3491 }
3492 }
3494 /* Return a TREE_VEC for the expansion of built-in template parameter pack
3495 CALL. */
3497 static tree
3499 tree in_decl)
3500 {
3510 }
3512 /* Structure used to track the progress of find_parameter_packs_r. */
3513 struct find_parameter_pack_data
3514 {
3515 /* TREE_LIST that will contain all of the parameter packs found by
3516 the traversal. */
3519 /* Set of AST nodes that have been visited by the traversal. */
3522 /* True iff we're making a type pack expansion. */
3524 };
3526 /* Identifies all of the argument packs that occur in a template
3527 argument and appends them to the TREE_LIST inside DATA, which is a
3528 find_parameter_pack_data structure. This is a subroutine of
3529 make_pack_expansion and uses_parameter_packs. */
3530 static tree
3532 {
3538 /* Handle type aliases/typedefs. */
3540 {
3547 }
3549 /* Identify whether this is a parameter pack or not. */
3551 {
3559 /* FALLTHRU */
3561 /* If the placeholder appears in the decl-specifier-seq of a function
3562 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3563 is a pack expansion, the invented template parameter is a template
3564 parameter pack. */
3574 {
3575 /* We don't want to walk into the type of a PARM_DECL,
3576 because we don't want to see the type parameter pack. */
3579 }
3582 /* Look through a lambda capture proxy to the field pack. */
3585 {
3591 }
3593 {
3595 find_parameter_packs_r,
3598 }
3610 /* Not a parameter pack. */
3612 }
3615 {
3616 /* Add this parameter pack to the list. */
3618 }
3624 /* This switch statement will return immediately if we don't find a
3625 parameter pack. */
3627 {
3632 /* Check the template itself. */
3635 /* Check the template arguments. */
3651 /* Fall through. */
3696 {
3697 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3698 type_pack_expansion_p to false so that any placeholders
3699 within the expression don't get marked as parameter packs. */
3707 }
3711 }
3714 }
3716 /* Determines if the expression or type T uses any parameter packs. */
3717 bool
3719 {
3728 }
3730 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3731 representation a base-class initializer into a parameter pack
3732 expansion. If all goes well, the resulting node will be an
3733 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3734 respectively. */
3735 tree
3737 {
3738 tree result;
3747 {
3748 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3749 class initializer. In this case, the TREE_PURPOSE will be a
3750 _TYPE node (representing the base class expansion we're
3751 initializing) and the TREE_VALUE will be a TREE_LIST
3752 containing the initialization arguments.
3754 The resulting expansion looks somewhat different from most
3755 expansions. Rather than returning just one _EXPANSION, we
3756 return a TREE_LIST whose TREE_PURPOSE is a
3757 TYPE_PACK_EXPANSION containing the bases that will be
3758 initialized. The TREE_VALUE will be identical to the
3759 original TREE_VALUE, which is a list of arguments that will
3760 be passed to each base. We do not introduce any new pack
3761 expansion nodes into the TREE_VALUE (although it is possible
3762 that some already exist), because the TREE_PURPOSE and
3763 TREE_VALUE all need to be expanded together with the same
3764 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3765 resulting TREE_PURPOSE will mention the parameter packs in
3766 both the bases and the arguments to the bases. */
3767 tree purpose;
3768 tree value;
3771 /* Determine which parameter packs will be used by the base
3772 class expansion. */
3781 {
3785 }
3788 {
3789 /* Collect the sets of parameter packs used in each of the
3790 initialization arguments. */
3792 {
3793 /* Determine which parameter packs will be expanded in this
3794 argument. */
3797 }
3798 }
3802 /* 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 {
3891 {
3895 {
3906 else
3911 else
3915 }
3918 }
3921 }
3923 /* Expand any parameter packs that occur in the template arguments in
3924 ARGS. */
3925 tree
3927 {
3936 /* First, determine if we need to expand anything, and the number of
3937 slots we'll need. */
3939 {
3944 {
3948 else
3950 }
3951 else
3952 {
3954 num_result_args++;
3955 }
3956 }
3958 /* If no expansion is necessary, we're done. */
3962 /* Expand arguments. */
3965 non_default_args_count =
3968 {
3971 {
3978 }
3979 else
3980 {
3983 }
3984 }
3988 }
3990 /* Checks if DECL shadows a template parameter.
3992 [temp.local]: A template-parameter shall not be redeclared within its
3993 scope (including nested scopes).
3995 Emits an error and returns TRUE if the DECL shadows a parameter,
3996 returns FALSE otherwise. */
3998 bool
4000 {
4001 tree olddecl;
4003 /* If we're not in a template, we can't possibly shadow a template
4004 parameter. */
4008 /* Figure out what we're shadowing. */
4012 /* If there's no previous binding for this name, we're not shadowing
4013 anything, let alone a template parameter. */
4017 /* If we're not shadowing a template parameter, we're done. Note
4018 that OLDDECL might be an OVERLOAD (or perhaps even an
4019 ERROR_MARK), so we can't just blithely assume it to be a _DECL
4020 node. */
4024 /* We check for decl != olddecl to avoid bogus errors for using a
4025 name inside a class. We check TPFI to avoid duplicate errors for
4026 inline member templates. */
4032 /* Don't complain about the injected class name, as we've already
4033 complained about the class itself. */
4040 else
4045 }
4047 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
4048 ORIG_LEVEL, DECL, and TYPE. */
4050 static tree
4054 tree decl,
4055 tree type)
4056 {
4067 }
4069 /* Find the canonical type parameter for the given template type
4070 parameter. Returns the canonical type parameter, which may be TYPE
4071 if no such parameter existed. */
4073 static tree
4075 {
4076 tree list;
4090 else
4091 {
4095 }
4096 }
4098 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
4099 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
4100 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
4101 new one is created. */
4103 static tree
4105 tsubst_flags_t complain)
4106 {
4111 {
4130 /* Template template parameters need this. */
4132 {
4139 }
4140 }
4143 }
4145 /* Process information from new template parameter PARM and append it
4146 to the LIST being built. This new parameter is a non-type
4147 parameter iff IS_NON_TYPE is true. This new parameter is a
4148 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4149 is in PARM_LOC. */
4151 tree
4154 {
4163 {
4167 {
4171 else
4173 }
4176 }
4179 {
4185 {
4186 /* [temp.param]
4188 The top-level cv-qualifiers on the template-parameter are
4189 ignored when determining its type. */
4194 && !is_parameter_pack
4195 /* If we're in a nested template parameter list, the template
4196 template parameter could be a parameter pack. */
4198 {
4199 /* This template parameter is not a parameter pack, but it
4200 should be. Complain about "bare" parameter packs. */
4203 /* Recover by calling this a parameter pack. */
4205 }
4206 }
4208 /* A template parameter is not modifiable. */
4217 processing_template_decl,
4222 }
4223 else
4224 {
4225 tree t;
4229 {
4231 /* This is for distinguishing between real templates and template
4232 template parameters */
4236 }
4237 else
4238 {
4240 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4243 }
4250 processing_template_decl,
4254 }
4258 /* Build requirements for the type/template parameter.
4259 This must be done after SET_DECL_TEMPLATE_PARM_P or
4260 process_template_parm could fail. */
4265 /* Build the parameter node linking the parameter declaration,
4266 its default argument (if any), and its constraints (if any). */
4271 }
4273 /* The end of a template parameter list has been reached. Process the
4274 tree list into a parameter vector, converting each parameter into a more
4275 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4276 as PARM_DECLs. */
4278 tree
4280 {
4285 /* Pop the dummy parameter level and add the real one. */
4288 current_template_parms
4293 {
4297 }
4302 }
4304 // Explicitly indicate the end of the template parameter list. We assume
4305 // that the current template parameters have been constructed and/or
4306 // managed explicitly, as when creating new template template parameters
4307 // from a shorthand constraint.
4308 void
4310 {
4312 }
4314 /* end_template_decl is called after a template declaration is seen. */
4316 void
4318 {
4324 /* This matches the pushlevel in begin_template_parm_list. */
4329 }
4331 /* Takes a TREE_LIST representing a template parameter and convert it
4332 into an argument suitable to be passed to the type substitution
4333 functions. Note that If the TREE_LIST contains an error_mark
4334 node, the returned argument is error_mark_node. */
4336 tree
4338 {
4351 {
4355 {
4356 /* Turn this argument into a TYPE_ARGUMENT_PACK
4357 with a single element, which expands T. */
4366 }
4367 }
4368 else
4369 {
4373 {
4374 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4375 with a single element, which expands T. */
4385 }
4386 else
4388 }
4390 }
4392 /* Given a single level of template parameters (a TREE_VEC), return it
4393 as a set of template arguments. */
4395 static tree
4397 {
4407 }
4409 /* Given a set of template parameters, return them as a set of template
4410 arguments. The template parameters are represented as a TREE_VEC, in
4411 the form documented in cp-tree.h for template arguments. */
4413 static tree
4415 {
4416 tree header;
4421 /* If there is only one level of template parameters, we do not
4422 create a TREE_VEC of TREE_VECs. Instead, we return a single
4423 TREE_VEC containing the arguments. */
4428 {
4433 else
4435 }
4438 }
4440 /* Within the declaration of a template, return the currently active
4441 template parameters as an argument TREE_VEC. */
4443 static tree
4445 {
4447 }
4449 /* Update the declared TYPE by doing any lookups which were thought to be
4450 dependent, but are not now that we know the SCOPE of the declarator. */
4452 tree
4454 {
4465 /* Don't bother building up the args in this case. */
4467 {
4468 /* tsubst in the args corresponding to the template parameters,
4469 including auto if present. Most things will be unchanged, but
4470 make_typename_type and tsubst_qualified_id will resolve
4471 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4474 tree pushed;
4476 {
4480 }
4485 }
4491 {
4494 else
4496 }
4498 }
4500 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4501 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4502 the new template is a member template. */
4504 tree
4506 {
4514 }
4516 struct template_parm_data
4517 {
4518 /* The level of the template parameters we are currently
4519 processing. */
4522 /* The index of the specialization argument we are currently
4523 processing. */
4526 /* An array whose size is the number of template parameters. The
4527 elements are nonzero if the parameter has been used in any one
4528 of the arguments processed so far. */
4531 /* An array whose size is the number of template arguments. The
4532 elements are nonzero if the argument makes use of template
4533 parameters of this level. */
4535 };
4537 /* Subroutine of push_template_decl used to see if each template
4538 parameter in a partial specialization is used in the explicit
4539 argument list. If T is of the LEVEL given in DATA (which is
4540 treated as a template_parm_data*), then DATA->PARMS is marked
4541 appropriately. */
4543 static int
4545 {
4553 {
4556 }
4558 /* In C++17 the type of a non-type argument is a deduced context. */
4563 data,
4564 NULL,
4567 /* Return zero so that for_each_template_parm will continue the
4568 traversal of the tree; we want to mark *every* template parm. */
4570 }
4572 /* Process the partial specialization DECL. */
4574 static tree
4576 {
4583 tree inner_parms;
4584 tree inst;
4594 /* A concept cannot be specialized. */
4596 {
4599 }
4604 /* We check that each of the template parameters given in the
4605 partial specialization is used in the argument list to the
4606 specialization. For example:
4608 template <class T> struct S;
4609 template <class T> struct S<T*>;
4611 The second declaration is OK because `T*' uses the template
4612 parameter T, whereas
4614 template <class T> struct S<int>;
4616 is no good. Even trickier is:
4618 template <class T>
4619 struct S1
4620 {
4621 template <class U>
4622 struct S2;
4623 template <class U>
4624 struct S2<T>;
4625 };
4627 The S2<T> declaration is actually invalid; it is a
4628 full-specialization. Of course,
4630 template <class U>
4631 struct S2<T (*)(U)>;
4633 or some such would have been OK. */
4641 {
4646 NULL,
4648 }
4651 {
4652 /* One of the template parms was not used in a deduced context in the
4653 specialization. */
4655 {
4659 }
4663 }
4668 /* [temp.class.spec]
4670 The argument list of the specialization shall not be identical to
4671 the implicit argument list of the primary template. */
4672 tree main_args
4675 && (!flag_concepts
4678 {
4682 else
4686 }
4688 /* A partial specialization that replaces multiple parameters of the
4689 primary template with a pack expansion is less specialized for those
4690 parameters. */
4692 {
4694 "primary template because it replaces multiple parameters "
4697 /* Avoid crash in process_partial_specialization. */
4699 }
4701 /* If we aren't in a dependent class, we can actually try deduction. */
4703 /* FIXME we should be able to handle a partial specialization of a
4704 partial instantiation, but currently we can't (c++/41727). */
4707 {
4711 maintmpl);
4712 }
4714 /* [temp.class.spec]
4716 A partially specialized non-type argument expression shall not
4717 involve template parameters of the partial specialization except
4718 when the argument expression is a simple identifier.
4720 The type of a template parameter corresponding to a specialized
4721 non-type argument shall not be dependent on a parameter of the
4722 specialization.
4724 Also, we verify that pack expansions only occur at the
4725 end of the argument list. */
4729 {
4736 {
4737 /* Extract the arguments from the argument pack. We'll be
4738 iterating over these in the following loop. */
4741 }
4744 {
4746 /* Get the Jth argument in the parameter pack. */
4750 {
4751 /* Pack expansions must come at the end of the
4752 argument list. */
4755 {
4759 else
4762 }
4763 }
4766 /* We only care about the pattern. */
4772 /* This next two lines are the `argument expression is not just a
4773 simple identifier' condition and also the `specialized
4774 non-type argument' bit. */
4778 {
4782 arg);
4783 else
4784 {
4785 /* Look at the corresponding template parameter,
4786 marking which template parameters its type depends
4787 upon. */
4791 {
4792 /* We haven't yet initialized TPD2. Do so now. */
4794 /* The number of parameters here is the number in the
4795 main template, which, as checked in the assertion
4796 above, is NARGS. */
4800 }
4802 /* Mark the template parameters. But this time, we're
4803 looking for the template parameters of the main
4804 template, not in the specialization. */
4811 NULL,
4815 {
4816 /* The type depended on some template parameters.
4817 If they are fully specialized in the
4818 specialization, that's OK. */
4827 "type %qT of template argument %qE depends "
4829 "type %qT of template argument %qE depends "
4831 type,
4832 arg);
4833 }
4834 }
4835 }
4836 }
4837 }
4839 /* We should only get here once. */
4843 // Build the template decl.
4852 /* Give template template parms a DECL_CONTEXT of the template
4853 for which they are a parameter. */
4855 {
4859 }
4862 /* We didn't register this in check_explicit_specialization so we could
4863 wait until the constraints were set. */
4865 else
4875 {
4881 {
4889 "declaration of %qD ambiguates earlier template "
4893 "partial specialization of %qD after instantiation "
4895 }
4896 }
4899 }
4901 /* PARM is a template parameter of some form; return the corresponding
4902 TEMPLATE_PARM_INDEX. */
4904 static tree
4906 {
4919 }
4921 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4922 parameter packs used by the template parameter PARM. */
4924 static void
4926 {
4927 /* A type parm can't refer to another parm. */
4931 {
4935 }
4942 }
4944 /* PARM is a template parameter pack. Return any parameter packs used in
4945 its type or the type of any of its template parameters. If there are
4946 any such packs, it will be instantiated into a fixed template parameter
4947 list by partial instantiation rather than be fully deduced. */
4949 tree
4951 {
4952 /* This can only be true in a member template. */
4955 /* This can only be true for a parameter pack. */
4958 /* A type parm can't refer to another parm. */
4972 }
4974 /* Check that a template declaration's use of default arguments and
4975 parameter packs is not invalid. Here, PARMS are the template
4976 parameters. IS_PRIMARY is true if DECL is the thing declared by
4977 a primary template. IS_PARTIAL is true if DECL is a partial
4978 specialization.
4980 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4981 declaration (but not a definition); 1 indicates a declaration, 2
4982 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4983 emitted for extraneous default arguments.
4985 Returns TRUE if there were no errors found, FALSE otherwise. */
4987 bool
4990 {
4993 tree parm_level;
4996 /* [temp.param]
4998 A default template-argument shall not be specified in a
4999 function template declaration or a function template definition, nor
5000 in the template-parameter-list of the definition of a member of a
5001 class template. */
5005 /* You can't have a function template declaration in a local
5006 scope, nor you can you define a member of a class template in a
5007 local scope. */
5015 /* A lambda doesn't have an explicit declaration; don't complain
5016 about the parms of the enclosing class. */
5023 /* If this is either a friend defined in the scope of the class
5024 or a member function. */
5030 /* And, if it was a member function, it really was defined in
5031 the scope of the class. */
5034 /* We already checked these parameters when the template was
5035 declared, so there's no need to do it again now. This function
5036 was defined in class scope, but we're processing its body now
5037 that the class is complete. */
5040 /* Core issue 226 (C++0x only): the following only applies to class
5041 templates. */
5044 {
5045 /* [temp.param]
5047 If a template-parameter has a default template-argument, all
5048 subsequent template-parameters shall have a default
5049 template-argument supplied. */
5051 {
5058 {
5068 {
5070 /* For better subsequent error-recovery, we indicate that
5071 there should have been a default argument. */
5074 }
5076 && !is_friend_decl
5077 /* Don't complain about an enclosing partial
5078 specialization. */
5083 /* A fixed parameter pack will be partially
5084 instantiated into a fixed length list. */
5086 {
5087 /* A primary class template can only have one
5088 parameter pack, at the end of the template
5089 parameter list. */
5097 }
5098 }
5099 }
5100 }
5103 || is_partial
5104 || !is_primary
5106 /* For an ordinary class template, default template arguments are
5107 allowed at the innermost level, e.g.:
5108 template <class T = int>
5109 struct S {};
5110 but, in a partial specialization, they're not allowed even
5111 there, as we have in [temp.class.spec]:
5113 The template parameter list of a specialization shall not
5114 contain default template argument values.
5116 So, for a partial specialization, or for a function template
5117 (in C++98/C++03), we look at all of them. */
5118 ;
5119 else
5120 /* But, for a primary class template that is not a partial
5121 specialization we look at all template parameters except the
5122 innermost ones. */
5125 /* Figure out what error message to issue. */
5140 else
5141 /* Per [temp.param]/9, "A default template-argument shall not be
5142 specified in the template-parameter-lists of the definition of
5143 a member of a class template that appears outside of the member's
5144 class.", thus if we aren't handling a member of a class template
5145 there is no need to examine the parameters. */
5149 /* If we're inside a class definition, there's no need to
5150 examine the parameters to the class itself. On the one
5151 hand, they will be checked when the class is defined, and,
5152 on the other, default arguments are valid in things like:
5153 template <class T = double>
5154 struct S { template <class U> void f(U); };
5155 Here the default argument for `S' has no bearing on the
5156 declaration of `f'. */
5158 else
5159 /* Check everything. */
5165 {
5172 {
5177 {
5179 {
5186 }
5188 /* Clear out the default argument so that we are not
5189 confused later. */
5191 }
5192 }
5194 /* At this point, if we're still interested in issuing messages,
5195 they must apply to classes surrounding the object declared. */
5199 }
5202 }
5204 /* Worker for push_template_decl_real, called via
5205 for_each_template_parm. DATA is really an int, indicating the
5206 level of the parameters we are interested in. If T is a template
5207 parameter of that level, return nonzero. */
5209 static int
5211 {
5217 else
5220 }
5222 /* Worker for uses_outer_template_parms, called via for_each_template_parm.
5223 DATA is really an int, indicating the innermost outer level of parameters.
5224 If T is a template parameter of that level or further out, return
5225 nonzero. */
5227 static int
5229 {
5235 else
5238 }
5240 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5241 parameters given by current_template_args, or reuses a
5242 previously existing one, if appropriate. Returns the DECL, or an
5243 equivalent one, if it is replaced via a call to duplicate_decls.
5245 If IS_FRIEND is true, DECL is a friend declaration. */
5247 tree
5249 {
5250 tree tmpl;
5251 tree args;
5252 tree info;
5253 tree ctx;
5257 /* True if the template is a member template, in the sense of
5258 [temp.mem]. */
5264 /* See if this is a partial specialization. */
5277 /* For a friend, we want the context of the friend function, not
5278 the type of which it is a friend. */
5282 /* In the case of a virtual function, we want the class in which
5283 it is defined. */
5285 else
5286 /* Otherwise, if we're currently defining some class, the DECL
5287 is assumed to be a member of the class. */
5296 /* See if this is a primary template. */
5299 /* A friend template that specifies a class context, i.e.
5300 template <typename T> friend void A<T>::f();
5301 is not primary. */
5306 else
5310 {
5317 {
5320 }
5322 {
5324 {
5327 }
5329 {
5330 /* [temp.mem]
5332 A destructor shall not be a member template. */
5335 }
5342 {
5343 /* [basic.stc.dynamic.allocation]
5345 An allocation function can be a function
5346 template. ... Template allocation functions shall
5347 have two or more parameters. */
5350 }
5351 }
5354 {
5355 /* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
5358 {
5364 }
5365 }
5368 /* alias-declaration */
5372 else
5373 {
5376 }
5377 }
5379 /* Check to see that the rules regarding the use of default
5380 arguments are not being violated. */
5384 /* Ensure that there are no parameter packs in the type of this
5385 declaration that have not been expanded. */
5387 {
5388 /* Check each of the arguments individually to see if there are
5389 any bare parameter packs. */
5395 {
5398 {
5399 /* This is a PARM_DECL that contains unexpanded parameter
5400 packs. We have already complained about this in the
5401 check_for_bare_parameter_packs call, so just replace
5402 these types with ERROR_MARK_NODE. */
5405 }
5409 }
5411 /* Check for bare parameter packs in the return type and the
5412 exception specifiers. */
5414 /* Errors were already issued, set return type to int
5415 as the frontend doesn't expect error_mark_node as
5416 the return type. */
5420 }
5425 {
5428 }
5441 {
5446 /* If DECL is a TYPE_DECL for a class-template, then there won't
5447 be DECL_LANG_SPECIFIC. The information equivalent to
5448 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5452 {
5453 /* Since a template declaration already existed for this
5454 class-type, we must be redeclaring it here. Make sure
5455 that the redeclaration is valid. */
5457 current_template_parms,
5459 /* We don't need to create a new TEMPLATE_DECL; just use the
5460 one we already had. */
5462 }
5463 else
5464 {
5466 member_template_p);
5471 {
5472 /* A specialization of a member template of a template
5473 class. */
5477 }
5478 }
5479 }
5480 else
5481 {
5487 {
5490 }
5498 {
5499 tree new_tmpl;
5501 /* The declaration is a specialization of a member
5502 template, declared outside the class. Therefore, the
5503 innermost template arguments will be NULL, so we
5504 replace them with the arguments determined by the
5505 earlier call to check_explicit_specialization. */
5508 new_tmpl
5510 member_template_p);
5520 args,
5523 }
5525 /* Make sure the template headers we got make sense. */
5530 {
5535 }
5536 else
5538 {
5543 {
5547 else
5551 /* Avoid crash in import_export_decl. */
5554 }
5559 /* Can happen in erroneous input. */
5561 else
5563 }
5565 /* Check that the parms are used in the appropriate qualifying scopes
5566 in the declarator. */
5570 {
5576 /* Avoid crash in import_export_decl. */
5579 }
5580 }
5585 /* Push template declarations for global functions and types. Note
5586 that we do not try to push a global template friend declared in a
5587 template class; such a thing may well depend on the template
5588 parameters of the class. */
5591 {
5596 /* Hide template friend classes that haven't been declared yet. */
5598 {
5601 }
5602 }
5605 {
5611 {
5614 /* It is a conversion operator. See if the type converted to
5615 depends on innermost template operands. */
5618 depth))
5620 }
5622 /* Give template template parms a DECL_CONTEXT of the template
5623 for which they are a parameter. */
5626 {
5630 }
5636 }
5638 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5639 back to its most general template. If TMPL is a specialization,
5640 ARGS may only have the innermost set of arguments. Add the missing
5641 argument levels if necessary. */
5649 else
5650 {
5655 }
5658 && !is_friend
5661 /* Set DECL_COMDAT on template instantiations; if we force
5662 them to be emitted by explicit instantiation or -frepo,
5663 mark_needed will tell cgraph to do the right thing. */
5667 }
5669 tree
5671 {
5673 }
5675 /* FN is an inheriting constructor that inherits from the constructor
5676 template INHERITED; turn FN into a constructor template with a matching
5677 template header. */
5679 tree
5681 {
5682 tree inner_parms
5685 tree parms
5696 }
5698 /* Called when a class template TYPE is redeclared with the indicated
5699 template PARMS, e.g.:
5701 template <class T> struct S;
5702 template <class T> struct S {}; */
5704 bool
5706 {
5707 tree tmpl;
5708 tree tmpl_parms;
5712 {
5715 }
5719 /* The type is nested in some template class. Nothing to worry
5720 about here; there are no new template parameters for the nested
5721 type. */
5725 {
5727 tmpl);
5729 }
5735 {
5745 }
5748 {
5749 tree tmpl_parm;
5750 tree parm;
5751 tree tmpl_default;
5752 tree parm_default;
5766 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5767 TEMPLATE_DECL. */
5777 {
5781 }
5784 {
5785 /* We have in [temp.param]:
5787 A template-parameter may not be given default arguments
5788 by two different declarations in the same scope. */
5793 }
5796 /* Update the previous template parameters (which are the ones
5797 that will really count) with the new default value. */
5800 /* Update the new parameters, too; they'll be used as the
5801 parameters for any members. */
5804 /* Give each template template parm in this redeclaration a
5805 DECL_CONTEXT of the template for which they are a parameter. */
5807 {
5810 }
5814 }
5816 // Cannot redeclare a class template with a different set of constraints.
5818 {
5823 }
5826 }
5828 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5829 to be used when the caller has already checked
5830 (processing_template_decl
5831 && !instantiation_dependent_expression_p (expr)
5832 && potential_constant_expression (expr))
5833 and cleared processing_template_decl. */
5835 tree
5837 {
5840 complain,
5844 }
5846 /* Simplify EXPR if it is a non-dependent expression. Returns the
5847 (possibly simplified) expression. */
5849 tree
5851 {
5855 /* If we're in a template, but EXPR isn't value dependent, simplify
5856 it. We're supposed to treat:
5858 template <typename T> void f(T[1 + 1]);
5859 template <typename T> void f(T[2]);
5861 as two declarations of the same function, for example. */
5864 {
5865 processing_template_decl_sentinel s;
5867 }
5869 }
5871 tree
5873 {
5875 }
5877 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5878 an uninstantiated expression. */
5880 tree
5882 {
5886 {
5889 else
5890 {
5891 processing_template_decl_sentinel s;
5893 }
5894 }
5896 }
5898 /* True iff T is a specialization of a variable template. */
5900 bool
5902 {
5907 }
5909 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5910 template declaration, or a TYPE_DECL for an alias declaration. */
5912 bool
5914 {
5922 }
5924 /* Return TRUE iff T is a specialization of an alias template. */
5926 bool
5928 {
5929 /* It's an alias template specialization if it's an alias and its
5930 TYPE_NAME is a specialization of a primary template. */
5936 }
5938 /* An alias template is complex from a SFINAE perspective if a template-id
5939 using that alias can be ill-formed when the expansion is not, as with
5940 the void_t template. We determine this by checking whether the
5941 expansion for the alias template uses all its template parameters. */
5943 struct uses_all_template_parms_data
5944 {
5947 };
5949 static int
5951 {
5959 }
5961 static bool
5963 {
5978 }
5980 /* Return TRUE iff T is a specialization of a complex alias template with
5981 dependent template-arguments. */
5983 bool
5985 {
5998 }
6000 /* Return the number of innermost template parameters in TMPL. */
6002 static int
6004 {
6007 }
6009 /* Return either TMPL or another template that it is equivalent to under DR
6010 1286: An alias that just changes the name of a template is equivalent to
6011 the other template. */
6013 static tree
6015 {
6018 {
6019 /* Determine if the alias is equivalent to an underlying template. */
6031 tree alias_args = INNERMOST_TEMPLATE_ARGS
6036 /* Alias is equivalent. Strip it and repeat. */
6038 }
6041 }
6043 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
6044 must be a reference-to-function or a pointer-to-function type, as specified
6045 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
6046 and check that the resulting function has external linkage. */
6048 static tree
6050 tsubst_flags_t complain)
6051 {
6054 linkage_kind linkage;
6069 /* [temp.arg.nontype]/1
6071 A template-argument for a non-type, non-template template-parameter
6072 shall be one of:
6073 [...]
6074 -- the address of an object or function with external [C++11: or
6075 internal] linkage. */
6078 {
6080 {
6086 else
6089 }
6091 }
6095 {
6097 {
6102 else
6106 }
6108 }
6110 accept:
6117 }
6119 /* Subroutine of convert_nontype_argument.
6120 Check if EXPR of type TYPE is a valid pointer-to-member constant.
6121 Emit an error otherwise. */
6123 static bool
6125 tsubst_flags_t complain)
6126 {
6137 {
6141 }
6143 }
6145 /* Returns TRUE iff the address of OP is value-dependent.
6147 14.6.2.4 [temp.dep.temp]:
6148 A non-integral non-type template-argument is dependent if its type is
6149 dependent or it has either of the following forms
6150 qualified-id
6151 & qualified-id
6152 and contains a nested-name-specifier which specifies a class-name that
6153 names a dependent type.
6155 We generalize this to just say that the address of a member of a
6156 dependent class is value-dependent; the above doesn't cover the
6157 address of a static data member named with an unqualified-id. */
6159 static bool
6161 {
6162 /* We could use get_inner_reference here, but there's no need;
6163 this is only relevant for template non-type arguments, which
6164 can only be expressed as &id-expression. */
6166 {
6170 }
6173 }
6175 /* The next set of functions are used for providing helpful explanatory
6176 diagnostics for failed overload resolution. Their messages should be
6177 indented by two spaces for consistency with the messages in
6178 call.c */
6180 static int
6182 {
6184 }
6186 /* Other failure functions should call this one, to provide a single function
6187 for setting a breakpoint on. */
6189 static int
6191 {
6193 }
6195 static int
6197 {
6202 }
6204 static int
6206 {
6212 }
6214 static int
6216 {
6220 }
6222 static int
6224 {
6227 " template parameter %qD is not a parameter pack, but "
6231 }
6233 static int
6235 {
6238 " template argument %qE does not match "
6242 }
6244 static int
6246 {
6250 }
6252 static int
6254 {
6260 }
6262 static int
6264 {
6266 {
6271 else
6273 " deduced conflicting values for non-type parameter "
6275 }
6277 }
6279 static int
6281 {
6284 " variable-sized array type %qT is not "
6286 arg);
6288 }
6290 static int
6292 {
6296 arg);
6298 }
6300 static int
6302 {
6304 {
6310 else
6315 }
6317 }
6319 static int
6321 {
6323 }
6325 static int
6328 {
6330 }
6332 static int
6335 {
6341 }
6343 static int
6346 {
6349 {
6357 }
6359 }
6361 static int
6363 {
6366 " template parameters of a template template argument are "
6369 }
6371 static int
6373 {
6379 }
6381 static int
6383 {
6388 }
6390 static int
6392 {
6396 arg);
6398 }
6400 /* Attempt to convert the non-type template parameter EXPR to the
6401 indicated TYPE. If the conversion is successful, return the
6402 converted value. If the conversion is unsuccessful, return
6403 NULL_TREE if we issued an error message, or error_mark_node if we
6404 did not. We issue error messages for out-and-out bad template
6405 parameters, but not simply because the conversion failed, since we
6406 might be just trying to do argument deduction. Both TYPE and EXPR
6407 must be non-dependent.
6409 The conversion follows the special rules described in
6410 [temp.arg.nontype], and it is much more strict than an implicit
6411 conversion.
6413 This function is called twice for each template argument (see
6414 lookup_template_class for a more accurate description of this
6415 problem). This means that we need to handle expressions which
6416 are not valid in a C++ source, but can be created from the
6417 first call (for instance, casts to perform conversions). These
6418 hacks can go away after we fix the double coercion problem. */
6420 static tree
6422 {
6423 tree expr_type;
6425 /* Detect immediately string literals as invalid non-type argument.
6426 This special-case is not needed for correctness (we would easily
6427 catch this later), but only to provide better diagnostic for this
6428 common user mistake. As suggested by DR 100, we do not mention
6429 linkage issues in the diagnostic as this is not the point. */
6430 /* FIXME we're making this OK. */
6432 {
6438 }
6440 /* Add the ADDR_EXPR now for the benefit of
6441 value_dependent_expression_p. */
6444 {
6448 }
6450 /* If we are in a template, EXPR may be non-dependent, but still
6451 have a syntactic, rather than semantic, form. For example, EXPR
6452 might be a SCOPE_REF, rather than the VAR_DECL to which the
6453 SCOPE_REF refers. Preserving the qualifying scope is necessary
6454 so that access checking can be performed when the template is
6455 instantiated -- but here we need the resolved form so that we can
6456 convert the argument. */
6469 else
6472 /* If the argument is non-dependent, perform any conversions in
6473 non-dependent context as well. */
6481 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6482 to a non-type argument of "nullptr". */
6486 /* In C++11, integral or enumeration non-type template arguments can be
6487 arbitrary constant expressions. Pointer and pointer to
6488 member arguments can be general constant expressions that evaluate
6489 to a null value, but otherwise still need to be of a specific form. */
6491 {
6493 /* A PTRMEM_CST is already constant, and a valid template
6494 argument for a parameter of pointer to member type, we just want
6495 to leave it in that form rather than lower it to a
6500 {
6504 {
6508 }
6509 }
6511 {
6516 }
6517 }
6519 /* HACK: Due to double coercion, we can get a
6520 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6521 which is the tree that we built on the first call (see
6522 below when coercing to reference to object or to reference to
6523 function). We just strip everything and get to the arg.
6524 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6525 for examples. */
6527 {
6533 {
6534 /* ??? Maybe we could use convert_from_reference here, but we
6535 would need to relax its constraints because the NOP_EXPR
6536 could actually change the type to something more cv-qualified,
6537 and this is not folded by convert_from_reference. */
6542 && (same_type_ignoring_top_level_qualifiers_p
6545 {
6548 }
6549 }
6550 }
6552 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6553 parameter is a pointer to object, through decay and
6554 qualification conversion. Let's strip everything. */
6556 {
6561 {
6562 /* Skip the ADDR_EXPR only if it is part of the decay for
6563 an array. Otherwise, it is part of the original argument
6564 in the source code. */
6569 }
6570 }
6572 /* [temp.arg.nontype]/5, bullet 1
6574 For a non-type template-parameter of integral or enumeration type,
6575 integral promotions (_conv.prom_) and integral conversions
6576 (_conv.integral_) are applied. */
6578 {
6587 /* Notice that there are constant expressions like '4 % 0' which
6588 do not fold into integer constants. */
6591 {
6593 {
6604 /* else cxx_constant_value complained but gave us
6605 a real constant, so go ahead. */
6607 }
6608 else
6610 }
6612 /* Avoid typedef problems. */
6615 }
6616 /* [temp.arg.nontype]/5, bullet 2
6618 For a non-type template-parameter of type pointer to object,
6619 qualification conversions (_conv.qual_) and the array-to-pointer
6620 conversion (_conv.array_) are applied. */
6622 {
6623 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6625 A template-argument for a non-type, non-template template-parameter
6626 shall be one of: [...]
6628 -- the name of a non-type template-parameter;
6629 -- the address of an object or function with external linkage, [...]
6630 expressed as "& id-expression" where the & is optional if the name
6631 refers to a function or array, or if the corresponding
6632 template-parameter is a reference.
6634 Here, we do not care about functions, as they are invalid anyway
6635 for a parameter of type pointer-to-object. */
6638 /* Non-type template parameters are OK. */
6639 ;
6644 {
6646 {
6649 "because %qD is a variable, not the address of "
6652 }
6654 {
6660 }
6661 /* Other values, like integer constants, might be valid
6662 non-type arguments of some other type. */
6664 }
6665 else
6666 {
6667 tree decl;
6672 {
6677 }
6679 {
6685 }
6687 {
6692 }
6693 }
6702 }
6703 /* [temp.arg.nontype]/5, bullet 3
6705 For a non-type template-parameter of type reference to object, no
6706 conversions apply. The type referred to by the reference may be more
6707 cv-qualified than the (otherwise identical) type of the
6708 template-argument. The template-parameter is bound directly to the
6709 template-argument, which must be an lvalue. */
6711 {
6713 expr_type))
6717 {
6722 }
6725 {
6730 }
6732 /* [temp.arg.nontype]/1
6734 A template-argument for a non-type, non-template template-parameter
6735 shall be one of: [...]
6737 -- the address of an object or function with external linkage. */
6740 {
6743 {
6746 "because a reference variable does not have a constant "
6749 }
6750 }
6754 /* OK, dependent reference. We don't want to ask whether a DECL is
6756 else
6757 {
6759 {
6765 }
6767 /* DR 1155 allows internal linkage in C++11 and up. */
6770 {
6776 }
6779 }
6783 }
6784 /* [temp.arg.nontype]/5, bullet 4
6786 For a non-type template-parameter of type pointer to function, only
6787 the function-to-pointer conversion (_conv.func_) is applied. If the
6788 template-argument represents a set of overloaded functions (or a
6789 pointer to such), the matching function is selected from the set
6790 (_over.over_). */
6792 {
6793 /* If the argument is a template-id, we might not have enough
6794 context information to decay the pointer. */
6796 {
6800 }
6803 /* Null pointer values are OK in C++11. */
6809 }
6810 /* [temp.arg.nontype]/5, bullet 5
6812 For a non-type template-parameter of type reference to function, no
6813 conversions apply. If the template-argument represents a set of
6814 overloaded functions, the matching function is selected from the set
6815 (_over.over_). */
6817 {
6819 {
6821 {
6826 }
6828 }
6833 }
6834 /* [temp.arg.nontype]/5, bullet 6
6836 For a non-type template-parameter of type pointer to member function,
6837 no conversions apply. If the template-argument represents a set of
6838 overloaded member functions, the matching member function is selected
6839 from the set (_over.over_). */
6841 {
6846 /* [temp.arg.nontype] bullet 1 says the pointer to member
6847 expression must be a pointer-to-member constant. */
6852 /* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
6853 into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
6857 /* There is no way to disable standard conversions in
6858 resolve_address_of_overloaded_function (called by
6859 instantiate_type). It is possible that the call succeeded by
6860 converting &B::I to &D::I (where B is a base of D), so we need
6861 to reject this conversion here.
6863 Actually, even if there was a way to disable standard conversions,
6864 it would still be better to reject them here so that we can
6865 provide a superior diagnostic. */
6867 {
6869 {
6873 /* If we are just one standard conversion off, explain. */
6877 }
6879 }
6880 }
6881 /* [temp.arg.nontype]/5, bullet 7
6883 For a non-type template-parameter of type pointer to data member,
6884 qualification conversions (_conv.qual_) are applied. */
6886 {
6887 /* [temp.arg.nontype] bullet 1 says the pointer to member
6888 expression must be a pointer-to-member constant. */
6896 }
6898 {
6900 {
6905 }
6907 }
6908 /* A template non-type parameter must be one of the above. */
6909 else
6912 /* Sanity check: did we actually convert the argument to the
6913 right type? */
6917 }
6919 /* Subroutine of coerce_template_template_parms, which returns 1 if
6920 PARM_PARM and ARG_PARM match using the rule for the template
6921 parameters of template template parameters. Both PARM and ARG are
6922 template parameters; the rest of the arguments are the same as for
6923 coerce_template_template_parms.
6924 */
6925 static int
6927 tree arg,
6928 tsubst_flags_t complain,
6929 tree in_decl,
6930 tree outer_args)
6931 {
6940 {
6942 /* We encounter instantiations of templates like
6943 template <template <template <class> class> class TT>
6944 class C; */
6945 {
6952 }
6953 /* Fall through. */
6958 /* Argument is a parameter pack but parameter is not. */
6963 /* The tsubst call is used to handle cases such as
6965 template <int> class C {};
6966 template <class T, template <T> class TT> class D {};
6967 D<int, C> d;
6969 i.e. the parameter list of TT depends on earlier parameters. */
6971 {
6976 }
6980 /* Argument is a parameter pack but parameter is not. */
6987 }
6990 }
6992 /* Coerce template argument list ARGLIST for use with template
6993 template-parameter TEMPL. */
6995 static tree
6997 tsubst_flags_t complain)
6998 {
6999 /* Consider an example where a template template parameter declared as
7001 template <class T, class U = std::allocator<T> > class TT
7003 The template parameter level of T and U are one level larger than
7004 of TT. To proper process the default argument of U, say when an
7005 instantiation `TT<int>' is seen, we need to build the full
7006 arguments containing {int} as the innermost level. Outer levels,
7007 available when not appearing as default template argument, can be
7008 obtained from the arguments of the enclosing template.
7010 Suppose that TT is later substituted with std::vector. The above
7011 instantiation is `TT<int, std::allocator<T> >' with TT at
7012 level 1, and T at level 2, while the template arguments at level 1
7013 becomes {std::vector} and the inner level 2 is {int}. */
7017 {
7019 /* We want arguments for the partial specialization, not arguments for
7020 the primary template. */
7022 else
7024 }
7026 {
7027 /* This is an argument of the current template, so we haven't set
7028 DECL_CONTEXT yet. */
7029 tree relevant_template_parms;
7031 /* Parameter levels that are greater than the level of the given
7032 template template parm are irrelevant. */
7039 }
7046 complain,
7049 }
7051 /* A cache of template template parameters with match-all default
7052 arguments. */
7054 static void
7056 {
7060 }
7061 static tree
7063 {
7068 }
7070 /* T is a bound template template-parameter. Copy its arguments into default
7071 arguments of the template template-parameter's template parameters. */
7073 static tree
7075 {
7098 {
7101 {
7104 }
7105 }
7109 }
7111 /* ARG is a bound potential template template-argument, and PARGS is a list
7112 of arguments for the corresponding template template-parameter. Adjust
7113 PARGS as appropriate for application to ARG's template, and if ARG is a
7114 BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
7115 arguments to the template template parameter. */
7117 static tree
7119 {
7123 {
7124 /* When comparing two template template-parameters in partial ordering,
7125 rewrite the one currently being used as an argument to have default
7126 arguments for all parameters. */
7132 }
7133 else
7134 {
7135 tree aparms
7140 }
7143 }
7145 /* Subroutine of unify for the case when PARM is a
7146 BOUND_TEMPLATE_TEMPLATE_PARM. */
7148 static int
7151 {
7155 /* The template template parm might be variadic and the argument
7156 not, so flatten both argument lists. */
7162 {
7163 /* In keeping with P0522R0, adjust P's template arguments
7164 to apply to A's template; then flatten it again. */
7167 }
7173 /* If the P0522 adjustment eliminated a pack expansion, deduce
7174 empty packs. */
7182 }
7184 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
7185 template template parameters. Both PARM_PARMS and ARG_PARMS are
7186 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
7187 or PARM_DECL.
7189 Consider the example:
7190 template <class T> class A;
7191 template<template <class U> class TT> class B;
7193 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
7194 the parameters to A, and OUTER_ARGS contains A. */
7196 static int
7198 tree arg_parms,
7199 tsubst_flags_t complain,
7200 tree in_decl,
7201 tree outer_args)
7202 {
7214 {
7215 /* P0522R0: A template template-parameter P is at least as specialized as
7216 a template template-argument A if, given the following rewrite to two
7217 function templates, the function template corresponding to P is at
7218 least as specialized as the function template corresponding to A
7219 according to the partial ordering rules for function templates
7220 ([temp.func.order]). Given an invented class template X with the
7221 template parameter list of A (including default arguments):
7223 * Each of the two function templates has the same template parameters,
7224 respectively, as P or A.
7226 * Each function template has a single function parameter whose type is
7227 a specialization of X with template arguments corresponding to the
7228 template parameters from the respective function template where, for
7229 each template parameter PP in the template parameter list of the
7230 function template, a corresponding template argument AA is formed. If
7231 PP declares a parameter pack, then AA is the pack expansion
7232 PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
7234 If the rewrite produces an invalid type, then P is not at least as
7235 specialized as A. */
7237 /* So coerce P's args to apply to A's parms, and then deduce between A's
7238 args and the converted args. If that succeeds, A is at least as
7239 specialized as P, so they match.*/
7246 {
7252 }
7253 }
7255 /* Determine whether we have a parameter pack at the end of the
7256 template template parameter's template parameter list. */
7258 {
7265 {
7279 }
7280 }
7286 /* Check all of the template parameters except the parameter pack at
7287 the end (if any). */
7289 {
7298 outer_args))
7301 }
7304 {
7305 /* Check each of the template parameters in the template
7306 argument against the template parameter pack at the end of
7307 the template template parameter. */
7314 {
7321 outer_args))
7323 }
7324 }
7327 }
7329 /* Verifies that the deduced template arguments (in TARGS) for the
7330 template template parameters (in TPARMS) represent valid bindings,
7331 by comparing the template parameter list of each template argument
7332 to the template parameter list of its corresponding template
7333 template parameter, in accordance with DR150. This
7334 routine can only be called after all template arguments have been
7335 deduced. It will return TRUE if all of the template template
7336 parameter bindings are okay, FALSE otherwise. */
7337 bool
7339 {
7343 /* We're dealing with template parms in this process. */
7349 {
7354 {
7359 {
7360 /* Look inside the argument pack. */
7363 }
7366 {
7370 /* Extract the next argument from the argument
7371 pack. */
7375 /* Look at the pattern of the pack expansion. */
7378 /* Extract the template parameters from the template
7379 argument. */
7385 /* Verify that we can coerce the template template
7386 parameters from the template argument to the template
7387 parameter. This requires an exact match. */
7389 && !coerce_template_template_parms
7391 targ_parms,
7392 tf_none,
7393 tparm,
7394 targs))
7395 {
7398 }
7399 }
7400 }
7401 }
7403 out:
7407 }
7409 /* Since type attributes aren't mangled, we need to strip them from
7410 template type arguments. */
7412 static tree
7414 {
7424 }
7426 /* And from inside dependent non-type arguments like sizeof(Type). */
7428 static tree
7430 {
7440 }
7442 // A template declaration can be substituted for a constrained
7443 // template template parameter only when the argument is more
7444 // constrained than the parameter.
7445 static bool
7447 {
7450 /* For now, allow constrained template template arguments
7451 and unconstrained template template parameters. */
7457 // If the template parameter is constrained, we need to rewrite its
7458 // constraints in terms of the ARG's template parameters. This ensures
7459 // that all of the template parameter types will have the same depth.
7460 //
7461 // Note that this is only valid when coerce_template_template_parm is
7462 // true for the innermost template parameters of PARM and ARG. In other
7463 // words, because coercion is successful, this conversion will be valid.
7465 {
7472 }
7475 }
7477 // Convert a placeholder argument into a binding to the original
7478 // parameter. The original parameter is saved as the TREE_TYPE of
7479 // ARG.
7482 {
7485 }
7487 /* Convert the indicated template ARG as necessary to match the
7488 indicated template PARM. Returns the converted ARG, or
7489 error_mark_node if the conversion was unsuccessful. Error and
7490 warning messages are issued under control of COMPLAIN. This
7491 conversion is for the Ith parameter in the parameter list. ARGS is
7492 the full set of template arguments deduced so far. */
7494 static tree
7496 tree arg,
7497 tree args,
7498 tsubst_flags_t complain,
7500 tree in_decl)
7501 {
7502 tree orig_arg;
7503 tree val;
7509 /* Trivially convert placeholders. */
7518 {
7519 /* The template argument was the name of some
7520 member function. That's usually
7521 invalid, but static members are OK. In any
7522 case, grab the underlying fields/functions
7523 and issue an error later if required. */
7526 }
7534 /* When determining whether an argument pack expansion is a template,
7535 look at the pattern. */
7539 /* Deal with an injected-class-name used as a template template arg. */
7541 {
7544 {
7554 }
7555 }
7557 is_tmpl_type =
7573 {
7575 {
7579 }
7582 "to refer to a type member of a template parameter, "
7587 typename_type,
7588 complain);
7591 }
7593 {
7595 {
7597 {
7609 else
7612 }
7613 }
7615 }
7617 {
7619 {
7626 else
7629 }
7631 }
7634 /* We already did the appropriate conversion when packing args. */
7637 {
7639 {
7641 /* The number of argument required is not known yet.
7642 Just accept it for now. */
7644 else
7645 {
7647 tree argparm;
7649 /* Strip alias templates that are equivalent to another
7650 template. */
7656 args))
7657 {
7660 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7661 TEMPLATE_DECL. */
7663 {
7668 }
7669 }
7670 else
7671 {
7673 {
7680 }
7683 }
7685 // Check that the constraints are compatible before allowing the
7686 // substitution.
7689 {
7691 {
7697 }
7699 }
7700 }
7701 }
7702 else
7704 /* We only form one instance of each template specialization.
7705 Therefore, if we use a non-canonical variant (i.e., a
7706 typedef), any future messages referring to the type will use
7707 the typedef, which is confusing if those future uses do not
7708 themselves also use the typedef. */
7711 }
7712 else
7713 {
7717 {
7721 }
7722 else
7730 /* We used to call digest_init here. However, digest_init
7731 will report errors, which we don't want when complain
7732 is zero. More importantly, digest_init will try too
7733 hard to convert things: for example, `0' should not be
7734 converted to pointer type at this point according to
7735 the standard. Accepting this is not merely an
7736 extension, since deciding whether or not these
7737 conversions can occur is part of determining which
7738 function template to call, or whether a given explicit
7739 argument specification is valid. */
7741 else
7751 {
7752 /* Reject template arguments that are references to built-in
7753 functions with no library fallbacks. */
7762 }
7765 {
7766 /* Strip typedefs from the SCOPE_REF. */
7769 complain);
7772 }
7773 }
7776 }
7778 /* Coerces the remaining template arguments in INNER_ARGS (from
7779 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7780 Returns the coerced argument pack. PARM_IDX is the position of this
7781 parameter in the template parameter list. ARGS is the original
7782 template argument list. */
7783 static tree
7786 tree args,
7787 tree inner_args,
7789 tree new_args,
7791 tree in_decl,
7792 tsubst_flags_t complain)
7793 {
7796 tree packed_args;
7797 tree argument_pack;
7804 {
7805 /* When the template parameter is a non-type template parameter pack
7806 or template template parameter pack whose type or template
7807 parameters use parameter packs, we know exactly how many arguments
7808 we are looking for. Build a vector of the instantiated decls for
7809 these template parameters in PACKED_PARMS. */
7810 /* We can't use make_pack_expansion here because it would interpret a
7811 _DECL as a use rather than a declaration. */
7825 /* If we're doing a partial instantiation of a member template,
7826 verify that all of the types used for the non-type
7827 template parameter pack are, in fact, valid for non-type
7828 template parameters. */
7831 {
7834 {
7838 }
7839 /* We don't know how many args we have yet, just
7840 use the unconverted ones for now. */
7842 }
7845 }
7846 /* Check if we have a placeholder pack, which indicates we're
7847 in the context of a introduction list. In that case we want
7848 to match this pack to the single placeholder. */
7852 {
7855 }
7856 else
7859 /* Convert the remaining arguments, which will be a part of the
7860 parameter pack "parm". */
7863 {
7869 {
7870 /* Once we've packed as many args as we have types, stop. */
7874 /* We don't know how many args we have yet, just
7875 use the unconverted ones for now. */
7877 else
7879 }
7882 {
7885 }
7886 else
7889 in_decl);
7893 }
7897 {
7902 }
7907 else
7908 {
7911 }
7918 }
7920 /* Returns the number of pack expansions in the template argument vector
7921 ARGS. */
7923 static int
7925 {
7930 {
7934 }
7936 }
7938 /* Convert all template arguments to their appropriate types, and
7939 return a vector containing the innermost resulting template
7940 arguments. If any error occurs, return error_mark_node. Error and
7941 warning messages are issued under control of COMPLAIN.
7943 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7944 for arguments not specified in ARGS. Otherwise, if
7945 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7946 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7947 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7948 ARGS. */
7950 static tree
7952 tree args,
7953 tree in_decl,
7954 tsubst_flags_t complain,
7957 {
7959 tree orig_inner_args;
7960 tree inner_args;
7961 tree new_args;
7962 tree new_inner_args;
7966 /* When used as a boolean value, indicates whether this is a
7967 variadic template parameter list. Since it's an int, we can also
7968 subtract it from nparms to get the number of non-variadic
7969 parameters. */
7974 /* Likewise for parameters with default arguments. */
7982 /* Determine if there are any parameter packs or default arguments. */
7984 {
7992 }
7995 /* If there are no parameters that follow a parameter pack, we need to
7996 expand any argument packs so that we can deduce a parameter pack from
7997 some non-packed args followed by an argument pack, as in variadic85.C.
7998 If there are such parameters, we need to leave argument packs intact
7999 so the arguments are assigned properly. This can happen when dealing
8000 with a nested class inside a partial specialization of a class
8001 template, as in variadic92.C, or when deducing a template parameter pack
8002 from a sub-declarator, as in variadic114.C. */
8006 /* Count any pack expansion args. */
8012 && require_all_args
8013 && !variadic_args_p
8014 && (!use_default_args
8017 {
8019 {
8021 {
8025 }
8026 else
8033 }
8036 }
8037 /* We can't pass a pack expansion to a non-pack parameter of an alias
8038 template (DR 1430). */
8042 && variadic_args_p
8044 {
8046 {
8048 {
8054 {
8057 "pack expansion argument for non-pack parameter "
8059 else
8061 "pack expansion argument for non-pack parameter "
8065 }
8066 }
8068 found:;
8069 }
8071 }
8073 /* We need to evaluate the template arguments, even though this
8074 template-id may be nested within a "sizeof". */
8083 {
8084 tree arg;
8085 tree parm;
8087 /* Get the Ith template parameter. */
8091 {
8094 }
8096 /* Calculate the next argument. */
8099 else
8104 {
8105 /* Some arguments will be placed in the
8106 template parameter pack PARM. */
8113 {
8114 /* We don't know how many args we have yet, just use the
8115 unconverted (and still packed) ones for now. */
8119 }
8123 /* Store this argument. */
8125 {
8126 lost++;
8127 /* We are done with all of the arguments. */
8129 }
8130 else
8131 {
8134 }
8137 }
8139 {
8141 {
8142 /* "If every valid specialization of a variadic template
8143 requires an empty template parameter pack, the template is
8144 ill-formed, no diagnostic required." So check that the
8145 pattern works with this parameter. */
8150 in_decl);
8152 {
8157 }
8159 /* Recover from missing typename. */
8163 /* We don't know how many args we have yet, just
8164 use the unconverted ones for now. */
8168 }
8169 }
8171 {
8172 /* There must be a default arg in this case. */
8175 /* The position of the first default template argument,
8176 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
8177 Record that. */
8181 }
8182 else
8186 {
8189 }
8191 /* This only occurs if there was an error in the template
8192 parameter list itself (which we would already have
8193 reported) that we are trying to recover from, e.g., a class
8194 template with a parameter list such as
8195 template<typename..., typename>. */
8197 else
8203 lost++;
8205 }
8210 {
8212 {
8217 }
8219 }
8229 }
8231 /* Convert all template arguments to their appropriate types, and
8232 return a vector containing the innermost resulting template
8233 arguments. If any error occurs, return error_mark_node. Error and
8234 warning messages are not issued.
8236 Note that no function argument deduction is performed, and default
8237 arguments are used to fill in unspecified arguments. */
8238 tree
8240 {
8242 }
8244 /* Convert all template arguments to their appropriate type, and
8245 instantiate default arguments as needed. This returns a vector
8246 containing the innermost resulting template arguments, or
8247 error_mark_node if unsuccessful. */
8248 tree
8250 tsubst_flags_t complain)
8251 {
8253 }
8255 /* Like coerce_template_parms. If PARMS represents all template
8256 parameters levels, this function returns a vector of vectors
8257 representing all the resulting argument levels. Note that in this
8258 case, only the innermost arguments are coerced because the
8259 outermost ones are supposed to have been coerced already.
8261 Otherwise, if PARMS represents only (the innermost) vector of
8262 parameters, this function returns a vector containing just the
8263 innermost resulting arguments. */
8265 static tree
8267 tree args,
8268 tree in_decl,
8269 tsubst_flags_t complain,
8272 {
8275 tree coerced_args;
8278 {
8280 tree level;
8286 {
8287 tree l;
8291 require_all_args,
8292 use_default_args);
8293 else
8300 }
8301 }
8302 else
8305 require_all_args,
8306 use_default_args);
8308 }
8310 /* Returns 1 if template args OT and NT are equivalent. */
8312 int
8314 {
8323 /* For member templates */
8332 {
8349 }
8353 {
8356 /* Don't treat an alias template specialization with dependent
8357 arguments as equivalent to its underlying type when used as a
8358 template argument; we need them to be distinct so that we
8359 substitute into the specialization arguments at instantiation
8360 time. And aliases can't be equivalent without being ==, so
8361 we don't need to look any deeper.
8363 During partial ordering, however, we need to treat them normally so
8364 that we can order uses of the same alias with different
8365 cv-qualification (79960). */
8369 else
8371 }
8374 else
8375 {
8376 /* Try to treat a template non-type argument that has been converted
8377 to the parameter type as equivalent to one that hasn't yet. */
8390 }
8391 }
8393 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
8394 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
8395 NEWARG_PTR with the offending arguments if they are non-NULL. */
8397 int
8401 {
8414 {
8419 {
8425 }
8426 }
8428 }
8432 {
8434 }
8436 static void
8438 {
8448 /* We are called both from instantiate_decl, where we've already had a
8449 tinst_level pushed, and instantiate_template, where we haven't.
8450 Compensate. */
8461 else
8470 }
8473 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
8474 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8475 documentation for TEMPLATE_ID_EXPR. */
8477 tree
8479 {
8480 tree type;
8488 {
8491 }
8494 {
8496 unknown_type_node,
8498 arglist);
8500 }
8507 }
8509 /* Within the scope of a template class S<T>, the name S gets bound
8510 (in build_self_reference) to a TYPE_DECL for the class, not a
8511 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8512 or one of its enclosing classes, and that type is a template,
8513 return the associated TEMPLATE_DECL. Otherwise, the original
8514 DECL is returned.
8516 Also handle the case when DECL is a TREE_LIST of ambiguous
8517 injected-class-names from different bases. */
8519 tree
8521 {
8525 /* DR 176: A lookup that finds an injected-class-name (10.2
8526 [class.member.lookup]) can result in an ambiguity in certain cases
8527 (for example, if it is found in more than one base class). If all of
8528 the injected-class-names that are found refer to specializations of
8529 the same class template, and if the name is followed by a
8530 template-argument-list, the reference refers to the class template
8531 itself and not a specialization thereof, and is not ambiguous. */
8533 {
8536 {
8542 }
8545 else
8547 }
8553 }
8555 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8556 parameters, find the desired type.
8558 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8560 IN_DECL, if non-NULL, is the template declaration we are trying to
8561 instantiate.
8563 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8564 the class we are looking up.
8566 Issue error and warning messages under control of COMPLAIN.
8568 If the template class is really a local class in a template
8569 function, then the FUNCTION_CONTEXT is the function in which it is
8570 being instantiated.
8572 ??? Note that this function is currently called *twice* for each
8573 template-id: the first time from the parser, while creating the
8574 incomplete type (finish_template_type), and the second type during the
8575 real instantiation (instantiate_template_class). This is surely something
8576 that we want to avoid. It also causes some problems with argument
8577 coercion (see convert_nontype_argument for more information on this). */
8579 static tree
8582 {
8584 tree t;
8587 spec_entry elt;
8588 hashval_t hash;
8591 {
8595 else
8596 {
8603 }
8606 }
8608 {
8611 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8612 an implicit typename for the second A. Deal with it. */
8617 {
8620 }
8621 }
8624 {
8627 }
8629 {
8633 }
8635 {
8638 }
8640 /* Issue an error message if we didn't find a template. */
8642 {
8646 }
8649 /* Make sure it's a user visible template, if it was named by
8650 the user. */
8653 {
8655 {
8659 }
8661 }
8665 /* An alias that just changes the name of a template is equivalent to the
8666 other template, so if any of the arguments are pack expansions, strip
8667 the alias to avoid problems with a pack expansion passed to a non-pack
8668 alias template parameter (DR 1430). */
8673 {
8674 tree parm;
8683 }
8684 else
8685 {
8687 tree gen_tmpl;
8688 tree type_decl;
8696 /* An error occurred while building the template TEMPL, and a
8697 diagnostic has most certainly been emitted for that
8698 already. Let's propagate that error. */
8707 {
8708 /* We've been given an incomplete set of template arguments.
8709 For example, given:
8711 template <class T> struct S1 {
8712 template <class U> struct S2 {};
8713 template <class U> struct S2<U*> {};
8714 };
8716 we will be called with an ARGLIST of `U*', but the
8717 TEMPLATE will be `template <class T> template
8718 <class U> struct S1<T>::S2'. We must fill in the missing
8719 arguments. */
8723 }
8725 /* Now we should have enough arguments. */
8728 /* From here on, we're only interested in the most general
8729 template. */
8731 /* Calculate the BOUND_ARGS. These will be the args that are
8732 actually tsubst'd into the definition to create the
8733 instantiation. */
8735 complain,
8740 /* We were unable to bind the arguments. */
8743 /* In the scope of a template class, explicit references to the
8744 template class refer to the type of the template, not any
8745 instantiation of it. For example, in:
8747 template <class T> class C { void f(C<T>); }
8749 the `C<T>' is just the same as `C'. Outside of the
8750 class, however, such a reference is an instantiation. */
8754 {
8759 }
8761 /* If we already have this specialization, return it. */
8771 /* If the the template's constraints are not satisfied,
8772 then we cannot form a valid type.
8774 Note that the check is deferred until after the hash
8775 lookup. This prevents redundant checks on previously
8776 instantiated specializations. */
8778 {
8780 {
8783 }
8785 }
8789 /* If the deduced arguments are invalid, then the binding
8790 failed. */
8794 complain))
8801 {
8806 }
8816 /* Create the type. */
8818 {
8819 /* The user referred to a specialization of an alias
8820 template represented by GEN_TMPL.
8822 [temp.alias]/2 says:
8824 When a template-id refers to the specialization of an
8825 alias template, it is equivalent to the associated
8826 type obtained by substitution of its
8827 template-arguments for the template-parameters in the
8828 type-id of the alias template. */
8831 /* Note that the call above (by indirectly calling
8832 register_specialization in tsubst_decl) registers the
8833 TYPE_DECL representing the specialization of the alias
8834 template. So next time someone substitutes ARGLIST for
8835 the template parms into the alias template (GEN_TMPL),
8836 she'll get that TYPE_DECL back. */
8840 }
8842 {
8844 {
8855 }
8856 else
8857 {
8858 /* We don't want to call start_enum for this type, since
8859 the values for the enumeration constants may involve
8860 template parameters. And, no one should be interested
8861 in the enumeration constants for such a type. */
8864 }
8868 }
8870 {
8876 /* A local class. Make sure the decl gets registered properly. */
8881 /* This instantiation is another name for the primary
8882 template type. Set the TYPE_CANONICAL field
8883 appropriately. */
8886 /* Some of the template arguments require structural
8887 equality testing, so this template class requires
8888 structural equality testing. */
8890 }
8891 else
8894 /* If we called start_enum or pushtag above, this information
8895 will already be set up. */
8897 {
8904 }
8905 else
8909 {
8915 {
8918 }
8919 }
8923 {
8927 {
8928 tree attributes
8936 }
8937 }
8939 /* Let's consider the explicit specialization of a member
8940 of a class template specialization that is implicitly instantiated,
8941 e.g.:
8942 template<class T>
8943 struct S
8944 {
8945 template<class U> struct M {}; //#0
8946 };
8948 template<>
8949 template<>
8950 struct S<int>::M<char> //#1
8951 {
8952 int i;
8953 };
8954 [temp.expl.spec]/4 says this is valid.
8956 In this case, when we write:
8957 S<int>::M<char> m;
8959 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8960 the one of #0.
8962 When we encounter #1, we want to store the partial instantiation
8963 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8965 For all cases other than this "explicit specialization of member of a
8966 class template", we just want to store the most general template into
8967 the CLASSTYPE_TI_TEMPLATE of M.
8969 This case of "explicit specialization of member of a class template"
8970 only happens when:
8971 1/ the enclosing class is an instantiation of, and therefore not
8972 the same as, the context of the most general template, and
8973 2/ we aren't looking at the partial instantiation itself, i.e.
8974 the innermost arguments are not the same as the innermost parms of
8975 the most general template.
8977 So it's only when 1/ and 2/ happens that we want to use the partial
8978 instantiation of the member template in lieu of its most general
8979 template. */
8983 /* the enclosing class must be an instantiation... */
8986 {
8990 tree partial_inst_args =
8997 use_partial_inst_tmpl =
8998 /*...and we must not be looking at the partial instantiation
8999 itself. */
9001 partial_inst_args);
9002 }
9005 /* This case is easy; there are no member templates involved. */
9007 else
9008 {
9009 /* This is a full instantiation of a member template. Find
9010 the partial instantiation of which this is an instance. */
9012 /* Temporarily reduce by one the number of levels in the ARGLIST
9013 so as to avoid comparing the last set of arguments. */
9017 /* FOUND is either a proper class type, or an alias
9018 template specialization. In the later case, it's a
9019 TYPE_DECL, resulting from the substituting of arguments
9020 for parameters in the TYPE_DECL of the alias template
9021 done earlier. So be careful while getting the template
9022 of FOUND. */
9024 ? found
9028 }
9030 // Build template info for the new specialization.
9039 /* Note this use of the partial instantiation so we can check it
9040 later in maybe_process_partial_specialization. */
9047 /* Now that the type has been registered on the instantiations
9048 list, we set up the enumerators. Because the enumeration
9049 constants may involve the enumeration type itself, we make
9050 sure to register the type first, and then create the
9051 constants. That way, doing tsubst_expr for the enumeration
9052 constants won't result in recursive calls here; we'll find
9053 the instantiation and exit above. */
9057 /* If the type makes use of template parameters, the
9058 code that generates debugging information will crash. */
9061 /* Possibly limit visibility based on template args. */
9068 }
9069 }
9071 /* Wrapper for lookup_template_class_1. */
9073 tree
9076 {
9077 tree ret;
9083 }
9085 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
9087 tree
9089 {
9090 /* The type of the expression is NULL_TREE since the template-id could refer
9091 to an explicit or partial specialization. */
9094 /* Except that concepts are always bool. */
9097 }
9099 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
9101 tree
9103 {
9107 /* We never want to return a VAR_DECL for a variable concept, since they
9108 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
9123 {
9125 {
9128 }
9130 }
9132 /* If a template-id refers to a specialization of a variable
9133 concept, then the expression is true if and only if the
9134 concept's constraints are satisfied by the given template
9135 arguments.
9137 NOTE: This is an extension of Concepts Lite TS that
9138 allows constraints to be used in expressions. */
9140 {
9143 }
9146 }
9148 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
9149 TARGS template args, and instantiate it if it's not dependent. */
9151 tree
9153 tsubst_flags_t complain)
9154 {
9157 {
9160 }
9163 }
9165 \f
9166 struct pair_fn_data
9167 {
9168 tree_fn_t fn;
9169 tree_fn_t any_fn;
9171 /* True when we should also visit template parameters that occur in
9172 non-deduced contexts. */
9175 };
9177 /* Called from for_each_template_parm via walk_tree. */
9179 static tree
9181 {
9188 #define WALK_SUBTREE(NODE) \
9189 do \
9190 { \
9191 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
9192 pfd->include_nondeduced_p, \
9193 pfd->any_fn); \
9194 if (result) goto out; \
9195 } \
9196 while (0)
9206 {
9210 /* Fall through. */
9216 else
9226 /* Since we're not going to walk subtrees, we have to do this
9227 explicitly here. */
9229 /* Fall through. */
9232 /* Check the return type. */
9235 /* Check the parameter types. Since default arguments are not
9236 instantiated until they are needed, the TYPE_ARG_TYPES may
9237 contain expressions that involve template parameters. But,
9238 no-one should be looking at them yet. And, once they're
9239 instantiated, they don't contain template parameters, so
9240 there's no point in looking at them then, either. */
9241 {
9242 tree parm;
9247 /* Since we've already handled the TYPE_ARG_TYPES, we don't
9248 want walk_tree walking into them itself. */
9250 }
9253 {
9257 }
9274 /* Fall through. */
9286 /* Record template parameters such as `T' inside `TT<T>'. */
9288 /* Fall through. */
9300 /* A template template parameter is encountered. */
9304 /* Already substituted template template parameter */
9309 /* A template-id in a TYPENAME_TYPE might be a deduced context after
9310 partial instantiation. */
9322 /* If there's no type, then this thing must be some expression
9323 involving template parameters. */
9345 }
9347 #undef WALK_SUBTREE
9349 /* We didn't find any template parameters we liked. */
9350 out:
9352 }
9354 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
9355 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
9356 call FN with the parameter and the DATA.
9357 If FN returns nonzero, the iteration is terminated, and
9358 for_each_template_parm returns 1. Otherwise, the iteration
9359 continues. If FN never returns a nonzero value, the value
9360 returned by for_each_template_parm is 0. If FN is NULL, it is
9361 considered to be the function which always returns 1.
9363 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
9364 parameters that occur in non-deduced contexts. When false, only
9365 visits those template parameters that can be deduced. */
9367 static tree
9371 tree_fn_t any_fn)
9372 {
9374 tree result;
9376 /* Set up. */
9382 /* Walk the tree. (Conceptually, we would like to walk without
9383 duplicates, but for_each_template_parm_r recursively calls
9384 for_each_template_parm, so we would need to reorganize a fair
9385 bit to use walk_tree_without_duplicates, so we keep our own
9386 visited list.) */
9389 else
9392 for_each_template_parm_r,
9396 /* Clean up. */
9398 {
9401 }
9404 }
9406 /* Returns true if T depends on any template parameter. */
9408 int
9410 {
9440 else
9441 {
9444 }
9449 }
9451 /* Returns true iff current_function_decl is an incompletely instantiated
9452 template. Useful instead of processing_template_decl because the latter
9453 is set to 0 during instantiate_non_dependent_expr. */
9455 bool
9457 {
9466 }
9468 /* Returns true if T depends on any template parameter with level LEVEL. */
9470 bool
9472 {
9475 }
9477 /* Returns true if the signature of DECL depends on any template parameter from
9478 its enclosing class. */
9480 bool
9482 {
9492 template_parm_outer_level,
9502 }
9504 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9505 ill-formed translation unit, i.e. a variable or function that isn't
9506 usable in a constant expression. */
9510 {
9514 }
9516 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9517 neglectable and instantiated from within an erroneous instantiation. */
9519 static bool
9521 {
9532 }
9540 /* We're starting to instantiate D; record the template instantiation context
9541 for diagnostics and to restore it later. */
9543 bool
9545 {
9547 }
9549 /* We're starting to instantiate D; record the template instantiation context
9550 at LOC for diagnostics and to restore it later. */
9552 bool
9554 {
9558 {
9559 /* Tell error.c not to try to instantiate any templates. */
9562 "template instantiation depth exceeds maximum of %d"
9564 max_tinst_depth);
9566 }
9568 /* If the current instantiation caused problems, don't let it instantiate
9569 anything else. Do allow deduction substitution and decls usable in
9570 constant expressions. */
9574 /* When not -quiet, dump template instantiations other than functions, since
9575 announce_function will take care of those. */
9594 }
9596 /* We're done instantiating this template; return to the instantiation
9597 context. */
9599 void
9601 {
9602 /* Restore the filename and line number stashed away when we started
9603 this instantiation. */
9607 }
9609 /* We're instantiating a deferred template; restore the template
9610 instantiation context in which the instantiation was requested, which
9611 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9613 static tree
9615 {
9627 }
9629 /* Returns the TINST_LEVEL which gives the original instantiation
9630 context. */
9634 {
9640 }
9642 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9643 vector of template arguments, as for tsubst.
9645 Returns an appropriate tsubst'd friend declaration. */
9647 static tree
9649 {
9650 tree new_friend;
9655 /* This was a friend declared with an explicit template
9656 argument list, e.g.:
9658 friend void f<>(T);
9660 to indicate that f was a template instantiation, not a new
9661 function declaration. Now, we have to figure out what
9662 instantiation of what template. */
9663 {
9665 tree new_args;
9666 tree tmpl;
9669 /* Friend functions are looked up in the containing namespace scope.
9670 We must enter that scope, to avoid finding member functions of the
9671 current class with same name. */
9686 tsk_none);
9688 }
9692 /* The NEW_FRIEND will look like an instantiation, to the
9693 compiler, but is not an instantiation from the point of view of
9694 the language. For example, we might have had:
9696 template <class T> struct S {
9697 template <class U> friend void f(T, U);
9698 };
9700 Then, in S<int>, template <class U> void f(int, U) is not an
9701 instantiation of anything. */
9707 {
9711 }
9713 /* The mangled name for the NEW_FRIEND is incorrect. The function
9714 is not a template instantiation and should not be mangled like
9715 one. Therefore, we forget the mangling here; we'll recompute it
9716 later if we need it. */
9718 {
9721 }
9724 {
9725 tree old_decl;
9726 tree new_friend_template_info;
9727 tree new_friend_result_template_info;
9728 tree ns;
9731 /* We must save some information from NEW_FRIEND before calling
9732 duplicate decls since that function will free NEW_FRIEND if
9733 possible. */
9735 new_friend_is_defn =
9740 {
9741 /* This declaration is a `primary' template. */
9744 new_friend_result_template_info
9746 }
9747 else
9750 /* Inside pushdecl_namespace_level, we will push into the
9751 current namespace. However, the friend function should go
9752 into the namespace of the template. */
9762 {
9763 /* This new friend declaration matched an existing
9764 declaration. For example, given:
9766 template <class T> void f(T);
9767 template <class U> class C {
9768 template <class T> friend void f(T) {}
9769 };
9771 the friend declaration actually provides the definition
9772 of `f', once C has been instantiated for some type. So,
9773 old_decl will be the out-of-class template declaration,
9774 while new_friend is the in-class definition.
9776 But, if `f' was called before this point, the
9777 instantiation of `f' will have DECL_TI_ARGS corresponding
9778 to `T' but not to `U', references to which might appear
9779 in the definition of `f'. Previously, the most general
9780 template for an instantiation of `f' was the out-of-class
9781 version; now it is the in-class version. Therefore, we
9782 run through all specialization of `f', adding to their
9783 DECL_TI_ARGS appropriately. In particular, they need a
9784 new set of outer arguments, corresponding to the
9785 arguments for this class instantiation.
9787 The same situation can arise with something like this:
9789 friend void f(int);
9790 template <class T> class C {
9791 friend void f(T) {}
9792 };
9794 when `C<int>' is instantiated. Now, `f(int)' is defined
9795 in the class. */
9798 /* On the other hand, if the in-class declaration does
9799 *not* provide a definition, then we don't want to alter
9800 existing definitions. We can just leave everything
9801 alone. */
9802 ;
9803 else
9804 {
9808 /* Overwrite whatever template info was there before, if
9809 any, with the new template information pertaining to
9810 the declaration. */
9814 {
9815 /* We should have called reregister_specialization in
9816 duplicate_decls. */
9821 /* Instantiate it if the global has already been used. */
9825 }
9826 else
9827 {
9828 tree t;
9830 /* Indicate that the old function template is a partial
9831 instantiation. */
9839 /* Reassign any specializations already in the hash table
9840 to the new more general template, and add the
9841 additional template args. */
9845 {
9847 spec_entry elt;
9859 register_specialization
9862 }
9864 }
9865 }
9867 /* The information from NEW_FRIEND has been merged into OLD_DECL
9868 by duplicate_decls. */
9870 }
9871 }
9872 else
9873 {
9877 /* In the code
9878 template <class T> class C {
9879 template <class U> friend void C1<U>::f (); // case 1
9880 friend void C2<T>::f (); // case 2
9881 };
9882 we only need to make sure CONTEXT is a complete type for
9883 case 2. To distinguish between the two cases, we note that
9884 CONTEXT of case 1 remains dependent type after tsubst while
9885 this isn't true for case 2. */
9895 {
9897 /* do_friend adds the TEMPLATE_DECL for any member friend
9898 template even if it isn't a member template, i.e.
9899 template <class T> friend A<T>::f();
9900 Look through it in that case. */
9904 /* Check to see that the declaration is really present, and,
9905 possibly obtain an improved declaration. */
9910 }
9911 }
9914 }
9916 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9917 template arguments, as for tsubst.
9919 Returns an appropriate tsubst'd friend type or error_mark_node on
9920 failure. */
9922 static tree
9924 {
9925 tree friend_type;
9926 tree tmpl;
9927 tree context;
9930 {
9933 }
9938 {
9941 else
9943 }
9945 /* Look for a class template declaration. We look for hidden names
9946 because two friend declarations of the same template are the
9947 same. For example, in:
9949 struct A {
9950 template <typename> friend class F;
9951 };
9952 template <typename> struct B {
9953 template <typename> friend class F;
9954 };
9956 both F templates are the same. */
9960 /* But, if we don't find one, it might be because we're in a
9961 situation like this:
9963 template <class T>
9964 struct S {
9965 template <class U>
9966 friend struct S;
9967 };
9969 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9970 for `S<int>', not the TEMPLATE_DECL. */
9972 {
9975 }
9978 {
9979 /* The friend template has already been declared. Just
9980 check to see that the declarations match, and install any new
9981 default parameters. We must tsubst the default parameters,
9982 of course. We only need the innermost template parameters
9983 because that is all that redeclare_class_template will look
9984 at. */
9987 {
9988 tree parms;
9989 location_t saved_input_location;
9999 }
10002 }
10003 else
10004 {
10005 /* The friend template has not already been declared. In this
10006 case, the instantiation of the template class will cause the
10007 injection of this template into the global scope. */
10012 /* The new TMPL is not an instantiation of anything, so we
10013 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
10014 the new type because that is supposed to be the corresponding
10015 template decl, i.e., TMPL. */
10022 /* Inject this template into the global scope. */
10024 }
10027 {
10030 else
10032 }
10035 }
10037 /* Returns zero if TYPE cannot be completed later due to circularity.
10038 Otherwise returns one. */
10040 static int
10042 {
10052 else
10054 }
10059 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
10060 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
10062 static tree
10065 {
10074 {
10081 clauses
10085 else
10087 }
10088 /* If the first attribute argument is an identifier, don't
10089 pass it through tsubst. Attributes like mode, format,
10090 cleanup and several target specific attributes expect it
10091 unmodified. */
10093 {
10094 tree chain
10099 }
10101 {
10102 /* An attribute pack expansion. */
10111 {
10115 }
10117 }
10118 else
10125 }
10127 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
10128 unchanged or a new TREE_LIST chain. */
10130 static tree
10133 {
10138 {
10142 }
10146 {
10149 {
10152 {
10154 do
10159 }
10160 }
10162 }
10165 }
10167 /* Apply any attributes which had to be deferred until instantiation
10168 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
10169 ARGS, COMPLAIN, IN_DECL are as tsubst. */
10171 static void
10174 {
10176 tree t;
10183 {
10187 /* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
10188 to our attributes parameter. */
10190 }
10191 else
10192 {
10194 /* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
10195 lookup_template_class_1, and should be preserved. */
10199 }
10203 {
10207 }
10211 {
10216 {
10219 {
10223 do
10226 }
10227 else
10229 }
10232 }
10233 }
10235 /* Perform (or defer) access check for typedefs that were referenced
10236 from within the template TMPL code.
10237 This is a subroutine of instantiate_decl and instantiate_class_template.
10238 TMPL is the template to consider and TARGS is the list of arguments of
10239 that template. */
10241 static void
10243 {
10244 location_t saved_location;
10255 {
10267 /* Make access check error messages point to the location
10268 of the use of the typedef. */
10272 tf_warning_or_error);
10273 }
10275 }
10277 static tree
10279 {
10281 tree typedecl;
10282 tree pbinfo;
10283 tree base_list;
10285 tree fn_context;
10294 /* Figure out which template is being instantiated. */
10298 /* Determine what specialization of the original template to
10299 instantiate. */
10302 {
10305 }
10307 {
10308 /* This TYPE is actually an instantiation of a partial
10309 specialization. We replace the innermost set of ARGS with
10310 the arguments appropriate for substitution. For example,
10311 given:
10313 template <class T> struct S {};
10314 template <class T> struct S<T*> {};
10316 and supposing that we are instantiating S<int*>, ARGS will
10317 presently be {int*} -- but we need {int}. */
10320 }
10321 else
10322 {
10325 }
10327 /* If the template we're instantiating is incomplete, then clearly
10328 there's nothing we can do. */
10332 /* If we've recursively instantiated too many templates, stop. */
10336 /* Now we're really doing the instantiation. Mark the type as in
10337 the process of being defined. */
10340 /* We may be in the middle of deferred access check. Disable
10341 it now. */
10348 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
10353 else
10354 {
10357 }
10358 /* Use #pragma pack from the template context. */
10364 /* Set the input location to the most specialized template definition.
10365 This is needed if tsubsting causes an error. */
10377 {
10380 /* Adjust visibility for template arguments. */
10382 }
10388 /* We should never instantiate a nested class before its enclosing
10389 class; we need to look up the nested class by name before we can
10390 instantiate it, and that lookup should instantiate the enclosing
10391 class. */
10397 {
10398 tree pbase_binfo;
10399 tree pushed_scope;
10402 /* We must enter the scope containing the type, as that is where
10403 the accessibility of types named in dependent bases are
10404 looked up from. */
10407 /* Substitute into each of the bases to determine the actual
10408 basetypes. */
10410 {
10411 tree base;
10417 {
10418 expanded_bases =
10425 }
10428 {
10430 /* Extract the already-expanded base class. */
10432 else
10433 /* Substitute to figure out the base class. */
10435 NULL_TREE);
10443 }
10444 }
10446 /* The list is now in reverse order; correct that. */
10451 }
10452 /* Now call xref_basetypes to set up all the base-class
10453 information. */
10461 /* Now that our base classes are set up, enter the scope of the
10462 class, so that name lookups into base classes, etc. will work
10463 correctly. This is precisely analogous to what we do in
10464 begin_class_definition when defining an ordinary non-template
10465 class, except we also need to push the enclosing classes. */
10468 /* Now members are processed in the order of declaration. */
10471 {
10475 {
10477 {
10478 /* Build new CLASSTYPE_NESTED_UTDS. */
10480 tree newtag;
10486 /* If the member is a class template, then -- even after
10487 substitution -- there may be dependent types in the
10488 template argument list for the class. We increment
10489 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10490 that function will assume that no types are dependent
10491 when outside of a template. */
10501 {
10505 /* Unfortunately, lookup_template_class sets
10506 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10507 instantiation (i.e., for the type of a member
10508 template class nested within a template class.)
10509 This behavior is required for
10510 maybe_process_partial_specialization to work
10511 correctly, but is not accurate in this case;
10512 the TAG is not an instantiation of anything.
10513 (The corresponding TEMPLATE_DECL is an
10514 instantiation, but the TYPE is not.) */
10517 /* Now, we call pushtag to put this NEWTAG into the scope of
10518 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10519 pushtag calling push_template_decl. We don't have to do
10520 this for enums because it will already have been done in
10521 tsubst_enum. */
10525 }
10526 }
10528 {
10529 /* Build new TYPE_METHODS. */
10530 tree r;
10539 /* Instantiate members marked with attribute used. */
10545 }
10548 /* A closure type for a lambda in a default argument for a
10549 member template. Ignore it; it will be instantiated with
10551 else
10552 {
10553 /* Build new TYPE_FIELDS. */
10555 {
10556 tree condition;
10559 condition =
10569 }
10571 {
10572 tree r;
10576 /* The file and line for this declaration, to
10577 assist in error message reporting. Since we
10578 called push_tinst_level above, we don't need to
10579 restore these. */
10589 {
10590 /* A capture pack became multiple fields. */
10593 }
10596 {
10600 {
10601 /* In [temp.inst]:
10603 [t]he initialization (and any associated
10604 side-effects) of a static data member does
10605 not occur unless the static data member is
10606 itself used in a way that requires the
10607 definition of the static data member to
10608 exist.
10610 Therefore, we do not substitute into the
10611 initialized for the static data member here. */
10612 finish_static_data_member_decl
10618 /* Instantiate members marked with attribute used. */
10621 }
10623 {
10624 /* Determine whether R has a valid type and can be
10625 completed later. If R is invalid, then its type
10626 is replaced by error_mark_node. */
10632 {
10633 /* If R's type couldn't be completed and
10634 it isn't a flexible array member (whose
10635 type is incomplete by definition) give
10636 an error. */
10639 }
10640 }
10642 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10643 such a thing will already have been added to the field
10644 list by tsubst_enum in finish_member_declaration in the
10645 CLASSTYPE_NESTED_UTDS case above. */
10649 {
10652 }
10653 }
10654 }
10655 }
10656 }
10657 else
10658 {
10661 {
10662 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10668 {
10669 /* template <class T> friend class C; */
10672 }
10674 {
10675 /* template <class T> friend class C::D; */
10681 }
10684 {
10685 /* This could be either
10687 friend class T::C;
10689 when dependent_type_p is false or
10691 template <class U> friend class T::C;
10693 otherwise. */
10694 /* Bump processing_template_decl in case this is something like
10695 template <class T> friend struct A<T>::B. */
10702 }
10705 {
10706 /* friend class C;
10708 where C hasn't been declared yet. Let's lookup name
10709 from namespace scope directly, bypassing any name that
10710 come from dependent base class. */
10713 /* The call to xref_tag_from_type does injection for friend
10714 classes. */
10716 friend_type =
10720 }
10722 /* friend class C<T>; */
10725 /* Otherwise it's
10727 friend class C;
10729 where C is already declared or
10731 friend class C<int>;
10733 We don't have to do anything in these cases. */
10736 /* Trick make_friend_class into realizing that the friend
10737 we're adding is a template, not an ordinary class. It's
10738 important that we use make_friend_class since it will
10739 perform some error-checking and output cross-reference
10740 information. */
10748 }
10749 else
10750 {
10751 /* Build new DECL_FRIENDLIST. */
10752 tree r;
10754 /* The file and line for this declaration, to
10755 assist in error message reporting. Since we
10756 called push_tinst_level above, we don't need to
10757 restore these. */
10761 {
10764 }
10769 {
10772 }
10773 }
10774 }
10775 }
10778 {
10779 /* Restore these before substituting into the lambda capture
10780 initializers. */
10783 }
10786 {
10789 {
10795 {
10796 /* Set function_depth to avoid garbage collection. */
10800 }
10802 /* We need to instantiate the capture list from the template
10803 after we've instantiated the closure members, but before we
10804 consider adding the conversion op. Also keep any captures
10805 that may have been added during instantiation of the op(). */
10807 tree tmpl_cap
10816 }
10817 else
10819 }
10821 /* Set the file and line number information to whatever is given for
10822 the class itself. This puts error messages involving generated
10823 implicit functions at a predictable point, and the same point
10824 that would be used for non-template classes. */
10831 /* We don't instantiate default arguments for member functions. 14.7.1:
10833 The implicit instantiation of a class template specialization causes
10834 the implicit instantiation of the declarations, but not of the
10835 definitions or default arguments, of the class member functions,
10836 member classes, static data members and member templates.... */
10838 /* Some typedefs referenced from within the template code need to be access
10839 checked at template instantiation time, i.e now. These types were
10840 added to the template at parsing time. Let's get those and perform
10841 the access checks then. */
10851 /* The vtable for a template class can be emitted in any translation
10852 unit in which the class is instantiated. When there is no key
10853 method, however, finish_struct_1 will already have added TYPE to
10854 the keyed_classes list. */
10859 }
10861 /* Wrapper for instantiate_class_template_1. */
10863 tree
10865 {
10866 tree ret;
10871 }
10873 static tree
10875 {
10876 tree r;
10882 else
10883 {
10890 }
10892 }
10894 /* Given a function parameter pack TMPL_PARM and some function parameters
10895 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10896 and set *SPEC_P to point at the next point in the list. */
10898 tree
10900 {
10901 /* Collect all of the extra "packed" parameters into an
10902 argument pack. */
10903 tree parmvec;
10913 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10919 /* Build the argument packs. */
10924 }
10926 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10927 NONTYPE_ARGUMENT_PACK. */
10929 static tree
10931 {
10933 }
10935 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10936 pack expansion with no extra args, 2 if it has extra args, or 0
10937 if it is not a pack expansion. */
10939 static int
10941 {
10947 /* A decl pack is itself an expansion. */
10954 }
10957 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10959 static tree
10961 {
10968 }
10970 /* This is a subroutine of tsubst_pack_expansion.
10972 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10973 mechanism to store the (non complete list of) arguments of the
10974 substitution and return a non substituted pack expansion, in order
10975 to wait for when we have enough arguments to really perform the
10976 substitution. */
10978 static bool
10982 {
10983 /* If one pack has an expansion and another pack has a normal
10984 argument or if one pack has an empty argument and an another
10985 one hasn't then tsubst_pack_expansion cannot perform the
10986 substitution and need to fall back on the
10987 PACK_EXPANSION_EXTRA mechanism. */
10995 {
10998 parm_pack;
11000 {
11005 /* We can't substitute a pack expansion with extra args into
11006 our pattern. */
11010 else
11012 }
11016 }
11018 }
11020 /* [temp.variadic]/6 says that:
11022 The instantiation of a pack expansion [...]
11023 produces a list E1,E2, ..., En, where N is the number of elements
11024 in the pack expansion parameters.
11026 This subroutine of tsubst_pack_expansion produces one of these Ei.
11028 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
11029 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
11030 PATTERN, and each TREE_VALUE is its corresponding argument pack.
11031 INDEX is the index 'i' of the element Ei to produce. ARGS,
11032 COMPLAIN, and IN_DECL are the same parameters as for the
11033 tsubst_pack_expansion function.
11035 The function returns the resulting Ei upon successful completion,
11036 or error_mark_node.
11038 Note that this function possibly modifies the ARGS parameter, so
11039 it's the responsibility of the caller to restore it. */
11041 static tree
11043 tree parm_packs,
11045 tree args /* This parm gets
11047 tsubst_flags_t complain,
11048 tree in_decl)
11049 {
11050 tree t;
11053 /* For each parameter pack, change the substitution of the parameter
11054 pack to the ith argument in its argument pack, then expand the
11055 pattern. */
11057 {
11062 ith_elem_is_expansion |=
11065 /* Select the Ith argument from the pack. */
11068 {
11070 {
11075 }
11076 else
11078 }
11079 else
11080 {
11085 {
11087 /* Update the corresponding argument. */
11089 }
11090 else
11091 /* Re-use the ARGUMENT_PACK_SELECT. */
11093 }
11095 }
11097 /* Substitute into the PATTERN with the (possibly altered)
11098 arguments. */
11100 /* Expanding a fixed parameter pack from
11101 coerce_template_parameter_pack. */
11106 {
11109 else
11112 }
11116 else
11119 /* If the Ith argument pack element is a pack expansion, then
11120 the Ith element resulting from the substituting is going to
11121 be a pack expansion as well. */
11126 }
11128 /* When the unexpanded parameter pack in a fold expression expands to an empty
11129 sequence, the value of the expression is as follows; the program is
11130 ill-formed if the operator is not listed in this table.
11132 && true
11133 || false
11134 , void() */
11136 tree
11138 {
11142 {
11151 }
11157 }
11159 /* Given a fold-expression T and a current LEFT and RIGHT operand,
11160 form an expression that combines the two terms using the
11161 operator of T. */
11163 static tree
11165 {
11169 // Handle compound assignment operators.
11174 {
11184 complain);
11185 }
11186 }
11188 /* Substitute ARGS into the pack of a fold expression T. */
11192 {
11194 }
11196 /* Substitute ARGS into the pack of a fold expression T. */
11200 {
11202 }
11204 /* Expand a PACK of arguments into a grouped as left fold.
11205 Given a pack containing elements A0, A1, ..., An and an
11206 operator @, this builds the expression:
11208 ((A0 @ A1) @ A2) ... @ An
11210 Note that PACK must not be empty.
11212 The operator is defined by the original fold expression T. */
11214 static tree
11216 {
11219 {
11222 }
11224 }
11226 /* Substitute into a unary left fold expression. */
11228 static tree
11230 tree in_decl)
11231 {
11236 {
11240 }
11243 else
11245 }
11247 /* Substitute into a binary left fold expression.
11249 Do ths by building a single (non-empty) vector of argumnts and
11250 building the expression from those elements. */
11252 static tree
11254 tree in_decl)
11255 {
11264 {
11269 }
11277 }
11279 /* Expand a PACK of arguments into a grouped as right fold.
11280 Given a pack containing elementns A0, A1, ..., and an
11281 operator @, this builds the expression:
11283 A0@ ... (An-2 @ (An-1 @ An))
11285 Note that PACK must not be empty.
11287 The operator is defined by the original fold expression T. */
11289 tree
11291 {
11292 // Build the expression.
11296 {
11299 }
11301 }
11303 /* Substitute into a unary right fold expression. */
11305 static tree
11307 tree in_decl)
11308 {
11313 {
11317 }
11320 else
11322 }
11324 /* Substitute into a binary right fold expression.
11326 Do ths by building a single (non-empty) vector of arguments and
11327 building the expression from those elements. */
11329 static tree
11331 tree in_decl)
11332 {
11341 {
11346 }
11355 }
11358 /* Substitute ARGS into T, which is an pack expansion
11359 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
11360 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
11361 (if only a partial substitution could be performed) or
11362 ERROR_MARK_NODE if there was an error. */
11363 tree
11365 tree in_decl)
11366 {
11367 tree pattern;
11371 tree result;
11379 /* Add in any args remembered from an earlier partial instantiation. */
11384 /* Determine the argument packs that will instantiate the parameter
11385 packs used in the expansion expression. While we're at it,
11386 compute the number of arguments to be expanded and make sure it
11387 is consistent. */
11390 {
11397 {
11402 else
11405 }
11407 {
11408 /* ??? Support use in other patterns. */
11412 }
11414 {
11415 /* We know we have correct local_specializations if this
11416 expansion is at function scope, or if we're dealing with a
11417 local parameter in a requires expression; for the latter,
11418 tsubst_requires_expr set it up appropriately. */
11421 else
11422 /* We can't rely on local_specializations for a parameter
11423 name used later in a function declaration (such as in a
11424 late-specified return type). Even if it exists, it might
11425 have the wrong value for a recursive call. */
11429 {
11430 /* This parameter pack was used in an unevaluated context. Just
11431 make a dummy decl, since it's only used for its type. */
11434 /* Partial instantiation of the parm_pack, we can't build
11435 up an argument pack yet. */
11437 else
11439 }
11440 }
11443 else
11444 {
11450 }
11457 /* This can only happen if we forget to expand an argument
11458 pack somewhere else. Just return an error, silently. */
11459 {
11463 }
11466 {
11470 /* Don't bother trying to do a partial substitution with
11471 incomplete packs; we'll try again after deduction. */
11478 {
11483 pattern);
11484 else
11486 pattern);
11488 }
11490 /* Keep track of the parameter packs and their corresponding
11491 argument packs. */
11494 }
11495 else
11496 {
11497 /* We can't substitute for this parameter pack. We use a flag as
11498 well as the missing_level counter because function parameter
11499 packs don't have a level. */
11502 }
11503 }
11505 /* If the expansion is just T..., return the matching argument pack, unless
11506 we need to call convert_from_reference on all the elements. This is an
11507 important optimization; see c++/68422. */
11510 {
11512 /* Types need no adjustment, nor does sizeof..., and if we still have
11513 some pack expansion args we won't do anything yet. */
11518 /* Also optimize expression pack expansions if we can tell that the
11519 elements won't have reference type. */
11525 /* Otherwise use the normal path so we get convert_from_reference. */
11526 }
11528 /* We cannot expand this expansion expression, because we don't have
11529 all of the argument packs we need. */
11531 {
11532 /* We got some full packs, but we can't substitute them in until we
11533 have values for all the packs. So remember these until then. */
11538 }
11540 {
11541 /* There were no real arguments, we're just replacing a parameter
11542 pack with another version of itself. Substitute into the
11543 pattern and return a PACK_EXPANSION_*. The caller will need to
11544 deal with that. */
11548 else
11552 }
11557 {
11558 /* We're in a late-specified return type, so create our own local
11559 specializations map; the current map is either NULL or (in the
11560 case of recursive unification) might have bindings that we don't
11561 want to use or alter. */
11564 }
11566 /* For each argument in each argument pack, substitute into the
11567 pattern. */
11571 {
11573 i,
11575 in_decl);
11578 {
11581 }
11582 }
11584 /* Update ARGS to restore the substitution from parameter packs to
11585 their argument packs. */
11587 {
11593 else
11594 {
11602 /* Update the corresponding argument. */
11606 else
11608 }
11609 }
11612 {
11615 }
11617 /* If the dependent pack arguments were such that we end up with only a
11618 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11624 }
11626 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11627 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11628 parameter packs; all parms generated from a function parameter pack will
11629 have the same DECL_PARM_INDEX. */
11631 tree
11633 {
11635 tree patparm;
11638 {
11644 }
11645 else
11646 {
11651 }
11654 }
11656 /* Make an argument pack out of the TREE_VEC VEC. */
11658 static tree
11660 {
11661 tree pack;
11665 else
11666 {
11669 }
11672 }
11674 /* Return an exact copy of template args T that can be modified
11675 independently. */
11677 static tree
11679 {
11687 {
11692 }
11698 }
11700 /* Substitute ARGS into the vector or list of template arguments T. */
11702 static tree
11704 {
11716 {
11718 tree new_arg;
11723 {
11724 /* Substitute into an expansion expression. */
11728 /* Add to the expanded length adjustment the number of
11729 expanded arguments. We subtract one from this
11730 measurement, because the argument pack expression
11731 itself is already counted as 1 in
11732 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11733 the argument pack is empty. */
11735 }
11737 {
11738 /* Substitute into each of the arguments. */
11747 else
11752 }
11753 else
11762 }
11767 /* Make space for the expanded arguments coming from template
11768 argument packs. */
11770 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11771 arguments for a member template.
11772 In that case each TREE_VEC in ORIG_T represents a level of template
11773 arguments, and ORIG_T won't carry any non defaulted argument count.
11774 It will rather be the nested TREE_VECs that will carry one.
11775 In other words, ORIG_T carries a non defaulted argument count only
11776 if it doesn't contain any nested TREE_VEC. */
11778 {
11782 }
11784 {
11788 {
11791 /* Now expand the template argument pack "in place". */
11794 }
11795 else
11796 {
11798 out++;
11799 }
11800 }
11803 }
11805 /* Substitute ARGS into one level PARMS of template parameters. */
11807 static tree
11809 {
11816 {
11824 }
11827 }
11829 /* Return the result of substituting ARGS into the template parameters
11830 given by PARMS. If there are m levels of ARGS and m + n levels of
11831 PARMS, then the result will contain n levels of PARMS. For
11832 example, if PARMS is `template <class T> template <class U>
11833 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11834 result will be `template <int*, double, class V>'. */
11836 static tree
11838 {
11842 /* When substituting into a template, we must set
11843 PROCESSING_TEMPLATE_DECL as the template parameters may be
11844 dependent if they are based on one-another, and the dependency
11845 predicates are short-circuit outside of templates. */
11852 {
11859 }
11864 }
11866 /* Return the result of substituting ARGS into one template parameter
11867 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11868 parameter and which TREE_PURPOSE is the default argument of the
11869 template parameter. */
11871 static tree
11873 {
11894 }
11896 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11897 type T. If T is not an aggregate or enumeration type, it is
11898 handled as if by tsubst. IN_DECL is as for tsubst. If
11899 ENTERING_SCOPE is nonzero, T is the context for a template which
11900 we are presently tsubst'ing. Return the substituted value. */
11902 static tree
11904 tree args,
11905 tsubst_flags_t complain,
11906 tree in_decl,
11908 {
11913 {
11918 /* Fall through. */
11922 {
11923 tree argvec;
11924 tree context;
11925 tree r;
11929 /* In "sizeof(X<I>)" we need to evaluate "I". */
11935 /* First, determine the context for the type we are looking
11936 up. */
11939 {
11942 /* If context is a nested class inside a class template,
11943 it may still need to be instantiated (c++/33959). */
11945 }
11947 /* Then, figure out what arguments are appropriate for the
11948 type we are trying to find. For example, given:
11950 template <class T> struct S;
11951 template <class T, class U> void f(T, U) { S<U> su; }
11953 and supposing that we are instantiating f<int, double>,
11954 then our ARGS will be {int, double}, but, when looking up
11955 S we only want {double}. */
11960 else
11961 {
11965 }
11971 }
11972 else
11973 /* This is not a template type, so there's nothing to do. */
11978 }
11979 }
11981 /* Substitute into the default argument ARG (a default argument for
11982 FN), which has the indicated TYPE. */
11984 tree
11986 {
11991 /* This can happen in invalid code. */
11995 /* This default argument came from a template. Instantiate the
11996 default argument here, not in tsubst. In the case of
11997 something like:
11999 template <class T>
12000 struct S {
12001 static T t();
12002 void f(T = t());
12003 };
12005 we must be careful to do name lookup in the scope of S<T>,
12006 rather than in the current class. */
12008 /* The "this" pointer is not valid in a default argument. */
12010 {
12015 }
12018 /* The default argument expression may cause implicitly defined
12019 member functions to be synthesized, which will result in garbage
12020 collection. We must treat this situation as if we were within
12021 the body of function so as to avoid collecting live data on the
12022 stack. */
12030 /* Restore the "this" pointer. */
12032 {
12035 }
12042 /* Make sure the default argument is reasonable. */
12048 }
12050 /* Substitute into all the default arguments for FN. */
12052 static void
12054 {
12055 tree arg;
12056 tree tmpl_args;
12060 /* If this function is not yet instantiated, we certainly don't need
12061 its default arguments. */
12064 /* Don't do this again for clones. */
12069 arg;
12075 complain);
12076 }
12078 /* Substitute the ARGS into the T, which is a _DECL. Return the
12079 result of the substitution. Issue error and warning messages under
12080 control of COMPLAIN. */
12082 static tree
12084 {
12085 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12086 location_t saved_loc;
12091 /* Set the filename and linenumber to improve error-reporting. */
12096 {
12098 {
12099 /* We can get here when processing a member function template,
12100 member class template, or template template parameter. */
12102 tree spec;
12103 tree tmpl_args;
12104 tree full_args;
12107 {
12108 /* Template template parameter is treated here. */
12112 /* If we get a real template back, return it. This can happen in
12113 the context of most_specialized_partial_spec. */
12116 else
12117 /* The new TEMPLATE_DECL was built in
12118 reduce_template_parm_level. */
12121 }
12123 /* We might already have an instance of this template.
12124 The ARGS are for the surrounding class type, so the
12125 full args contain the tsubst'd args for the context,
12126 plus the innermost args from the template decl. */
12130 /* Because this is a template, the arguments will still be
12131 dependent, even after substitution. If
12132 PROCESSING_TEMPLATE_DECL is not set, the dependency
12133 predicates will short-circuit. */
12141 /* If this is a default template template argument,
12142 tsubst might not have changed anything. */
12149 {
12152 }
12154 /* Make a new template decl. It will be similar to the
12155 original, but will record the current template arguments.
12156 We also create a new function declaration, which is just
12157 like the old one, but points to this new template, rather
12158 than the old one. */
12163 // Build new template info linking to the original template decl.
12168 {
12169 tree new_type;
12177 /* For a partial specialization, we need to keep pointing to
12178 the primary template. */
12184 }
12185 else
12186 {
12187 tree new_decl;
12199 }
12205 /* The template parameters for this new template are all the
12206 template parameters for the old template, except the
12207 outermost level of parameters. */
12210 complain);
12216 /* Record this non-type partial instantiation. */
12220 }
12224 {
12225 tree ctx;
12228 tree gen_tmpl;
12229 tree type;
12234 /* Nobody should be tsubst'ing into non-template functions. */
12238 {
12239 tree spec;
12241 /* If T is not dependent, just return it. */
12245 /* Calculate the most general template of which R is a
12246 specialization, and the complete set of arguments used to
12247 specialize R. */
12250 (DECL_TEMPLATE_RESULT
12256 /* Check to see if we already have this specialization. */
12261 {
12264 }
12266 /* We can see more levels of arguments than parameters if
12267 there was a specialization of a member template, like
12268 this:
12270 template <class T> struct S { template <class U> void f(); }
12271 template <> template <class U> void S<int>::f(U);
12273 Here, we'll be substituting into the specialization,
12274 because that's where we can find the code we actually
12275 want to generate, but we'll have enough arguments for
12276 the most general template.
12278 We also deal with the peculiar case:
12280 template <class T> struct S {
12281 template <class U> friend void f();
12282 };
12283 template <class U> void f() {}
12284 template S<int>;
12285 template void f<double>();
12287 Here, the ARGS for the instantiation of will be {int,
12288 double}. But, we only need as many ARGS as there are
12289 levels of template parameters in CODE_PATTERN. We are
12290 careful not to get fooled into reducing the ARGS in
12291 situations like:
12293 template <class T> struct S { template <class U> void f(U); }
12294 template <class T> template <> void S<T>::f(int) {}
12296 which we can spot because the pattern will be a
12297 specialization in this case. */
12299 parms_depth =
12304 }
12305 else
12306 {
12307 /* This special case arises when we have something like this:
12309 template <class T> struct S {
12310 friend void f<int>(int, double);
12311 };
12313 Here, the DECL_TI_TEMPLATE for the friend declaration
12314 will be an IDENTIFIER_NODE. We are being called from
12315 tsubst_friend_function, and we want only to create a
12316 new decl (R) with appropriate types so that we can call
12317 determine_specialization. */
12319 }
12322 {
12325 else
12329 }
12330 else
12331 {
12334 }
12339 /* If we hit excessive deduction depth, the type is bogus even if
12340 it isn't error_mark_node, so don't build a decl. */
12344 /* We do NOT check for matching decls pushed separately at this
12345 point, as they may not represent instantiations of this
12346 template, and in any case are considered separate under the
12347 discrete model. */
12351 /* Clear out the mangled name and RTL for the instantiation. */
12354 /* Leave DECL_INITIAL set on deleted instantiations. */
12359 /* OpenMP UDRs have the only argument a reference to the declared
12360 type. We want to diagnose if the declared type is a reference,
12361 which is invalid, but as references to references are usually
12362 quietly merged, diagnose it here. */
12364 {
12365 tree argtype
12370 "reference type %qT in "
12374 argtype);
12375 }
12378 /* Type-conversion operator. Reconstruct the name, in
12379 case it's the name of one of the template's parameters. */
12389 /* If this is an instantiation of a function with internal
12390 linkage, we already know what object file linkage will be
12391 assigned to the instantiation. */
12400 /* We'll re-clone as appropriate in instantiate_template. */
12403 /* If we aren't complaining now, return on error before we register
12404 the specialization so that we'll complain eventually. */
12410 /* When instantiating a constrained member, substitute
12411 into the constraints to create a new constraint. */
12414 {
12417 }
12419 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
12420 this in the special friend case mentioned above where
12421 GEN_TMPL is NULL. */
12423 {
12428 tree new_r
12431 /* We instantiated this while substituting into
12432 the type earlier (template/friend54.C). */
12435 /* We're not supposed to instantiate default arguments
12436 until they are called, for a template. But, for a
12437 declaration like:
12439 template <class T> void f ()
12440 { extern void g(int i = T()); }
12442 we should do the substitution when the template is
12443 instantiated. We handle the member function case in
12444 instantiate_class_template since the default arguments
12445 might refer to other members of the class. */
12450 }
12451 else
12454 /* Copy the list of befriending classes. */
12458 {
12462 in_decl);
12463 }
12466 {
12470 /* If this is an instantiation of a member template, clone it.
12471 If it isn't, that'll be handled by
12472 clone_constructors_and_destructors. */
12475 }
12486 /* Possibly limit visibility based on template args. */
12489 {
12493 }
12501 }
12505 {
12513 {
12514 /* If there is a local specialization that isn't a
12515 parameter pack, it means that we're doing a "simple"
12516 substitution from inside tsubst_pack_expansion. Just
12517 return the local specialization (which will be a single
12518 parm). */
12525 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12526 the parameters in this function parameter pack. */
12530 {
12533 /* Zero-length parameter packs are boring. Just substitute
12534 into the chain. */
12538 }
12539 else
12540 {
12541 /* All we did was update the type. Make a note of that. */
12544 }
12545 }
12547 /* Loop through all of the parameters we'll build. When T is
12548 a function parameter pack, LEN is the number of expanded
12549 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12552 {
12559 /* We're on the Ith parameter of the function parameter
12560 pack. */
12561 {
12562 /* Get the Ith type. */
12565 /* Rename the parameter to include the index. */
12568 }
12570 /* We're dealing with a normal parameter. */
12578 {
12581 else
12584 }
12594 /* Keep track of the first new parameter we
12595 generate. That's what will be returned to the
12596 caller. */
12600 /* Build a proper chain of parameters when substituting
12601 into a function parameter pack. */
12604 }
12606 /* If cp_unevaluated_operand is set, we're just looking for a
12607 single dummy parameter, so don't keep going. */
12612 /* FIRST_R contains the start of the chain we've built. */
12614 }
12618 {
12625 {
12626 /* This field is a lambda capture pack. Return a TREE_VEC of
12627 the expanded fields to instantiate_class_template_1 and
12628 store them in the specializations hash table as a
12629 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12633 {
12636 }
12637 else
12638 {
12639 /* All we did was update the type. Make a note of that. */
12642 }
12643 }
12646 {
12649 {
12653 }
12663 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12664 non-bit-fields DECL_INITIAL is a non-static data member
12665 initializer, which gets deferred instantiation. */
12671 {
12672 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12673 NSDMI in perform_member_init. Still set DECL_INITIAL
12674 so that we know there is one. */
12679 }
12680 /* We don't have to set DECL_CONTEXT here; it is set by
12681 finish_member_declaration. */
12689 }
12692 {
12697 }
12698 }
12702 /* We reach here only for member using decls. We also need to check
12703 uses_template_parms because DECL_DEPENDENT_P is not set for a
12704 using-declaration that designates a member of the current
12705 instantiation (c++/53549). */
12708 {
12712 {
12717 {
12721 {
12724 }
12725 else
12726 {
12729 }
12731 }
12732 }
12733 else
12734 {
12740 else
12741 {
12744 }
12745 }
12746 }
12747 else
12748 {
12751 }
12756 {
12759 tree spec;
12761 tree ctx;
12770 {
12771 /* If this is the canonical decl, we don't have to
12772 mess with instantiations, and often we can't (for
12773 typename, template type parms and such). Note that
12774 TYPE_NAME is not correct for the above test if
12775 we've copied the type for a typedef. */
12781 }
12783 /* Check to see if we already have the specialization we
12784 need. */
12787 {
12788 /* T is a static data member or namespace-scope entity.
12789 We have to substitute into namespace-scope variables
12790 (not just variable templates) because of cases like:
12792 template <class T> void f() { extern T t; }
12794 where the entity referenced is not known until
12795 instantiation time. */
12799 {
12801 complain,
12803 /* If CTX is unchanged, then T is in fact the
12804 specialization we want. That situation occurs when
12805 referencing a static data member within in its own
12806 class. We can use pointer equality, rather than
12807 same_type_p, because DECL_CONTEXT is always
12808 canonical... */
12810 /* ... unless T is a member template; in which
12811 case our caller can be willing to create a
12812 specialization of that template represented
12813 by T. */
12817 }
12820 {
12825 argvec = (coerce_innermost_template_parms
12833 }
12834 }
12835 else
12836 {
12837 /* A local variable. */
12839 /* Subsequent calls to pushdecl will fill this in. */
12841 /* Unless this is a reference to a static variable from an
12842 enclosing function, in which case we need to fill it in now. */
12844 {
12848 }
12850 }
12851 /* If we already have the specialization we need, there is
12852 nothing more to do. */
12854 {
12857 }
12859 /* Create a new node for the specialization we need. */
12862 {
12865 else
12872 }
12874 {
12875 /* Even if the original location is out of scope, the
12876 newly substituted one is not. */
12883 {
12884 /* It may seem that this case cannot occur, since:
12886 typedef void f();
12887 void g() { f x; }
12889 declares a function, not a variable. However:
12891 typedef void f();
12892 template <typename T> void g() { T t; }
12893 template void g<f>();
12895 is an attempt to declare a variable with function
12896 type. */
12898 /* R is not yet sufficiently initialized, so we
12899 just use its name. */
12902 }
12904 /* Wait until cp_finish_decl to set this again, to handle
12905 circular dependency (template/instantiate6.C). */
12910 {
12915 {
12918 }
12920 }
12924 }
12930 /* Clear out the mangled name and RTL for the instantiation. */
12934 /* The initializer must not be expanded until it is required;
12935 see [temp.inst]. */
12943 {
12944 /* Possibly limit visibility based on template args. */
12947 {
12951 }
12953 }
12956 {
12957 /* A static data member declaration is always marked
12958 external when it is declared in-class, even if an
12959 initializer is present. We mimic the non-template
12960 processing here. */
12968 }
12969 else
12970 {
12975 }
12983 /* Preserve a typedef that names a type. */
12985 {
12989 /* An alias template specialization can be dependent
12990 even if its underlying type is not. */
12992 }
12995 }
13000 }
13001 #undef RETURN
13003 out:
13004 /* Restore the file and line information. */
13008 }
13010 /* Substitute into the ARG_TYPES of a function type.
13011 If END is a TREE_CHAIN, leave it and any following types
13012 un-substituted. */
13014 static tree
13016 tree args,
13017 tree end,
13018 tsubst_flags_t complain,
13019 tree in_decl)
13020 {
13021 tree remaining_arg_types;
13025 tree default_arg;
13036 {
13037 /* For a pack expansion, perform substitution on the
13038 entire expression. Later on, we'll handle the arguments
13039 one-by-one. */
13044 /* So that we'll spin through the parameters, one by one. */
13046 else
13047 {
13048 /* We only partially substituted into the parameter
13049 pack. Our type is TYPE_PACK_EXPANSION. */
13052 }
13053 }
13066 {
13068 {
13072 }
13074 }
13075 /* DR 657. */
13079 /* Do array-to-pointer, function-to-pointer conversion, and ignore
13080 top-level qualifiers as required. */
13083 /* We do not substitute into default arguments here. The standard
13084 mandates that they be instantiated only when needed, which is
13085 done in build_over_call. */
13089 {
13090 /* We've instantiated a template before its default arguments
13091 have been parsed. This can happen for a nested template
13092 class, and is not an error unless we require the default
13093 argument in a call of this function. */
13094 remaining_arg_types =
13097 }
13098 else
13099 remaining_arg_types =
13101 }
13104 }
13106 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
13107 *not* handle the exception-specification for FNTYPE, because the
13108 initial substitution of explicitly provided template parameters
13109 during argument deduction forbids substitution into the
13110 exception-specification:
13112 [temp.deduct]
13114 All references in the function type of the function template to the
13115 corresponding template parameters are replaced by the specified tem-
13116 plate argument values. If a substitution in a template parameter or
13117 in the function type of the function template results in an invalid
13118 type, type deduction fails. [Note: The equivalent substitution in
13119 exception specifications is done only when the function is instanti-
13120 ated, at which point a program is ill-formed if the substitution
13121 results in an invalid type.] */
13123 static tree
13125 tree args,
13126 tsubst_flags_t complain,
13127 tree in_decl)
13128 {
13129 tree return_type;
13131 tree fntype;
13133 /* The TYPE_CONTEXT is not used for function/method types. */
13136 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
13137 failure. */
13141 {
13142 /* Substitute the argument types. */
13154 {
13155 /* DR 1207: 'this' is in scope in the trailing return type. */
13157 }
13159 /* Substitute the return type. */
13163 {
13166 }
13167 }
13168 else
13169 /* Substitute the return type. */
13174 /* DR 486 clarifies that creation of a function type with an
13175 invalid return type is a deduction failure. */
13178 {
13180 {
13183 else
13185 }
13187 }
13188 /* And DR 657. */
13193 {
13194 /* Substitute the argument types. */
13199 }
13201 /* Construct a new type node and return it. */
13203 {
13208 }
13209 else
13210 {
13212 /* Don't pick up extra function qualifiers from the basetype. */
13215 {
13216 /* [temp.deduct]
13218 Type deduction may fail for any of the following
13219 reasons:
13221 -- Attempting to create "pointer to member of T" when T
13222 is not a class type. */
13225 r);
13227 }
13232 }
13239 }
13241 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
13242 ARGS into that specification, and return the substituted
13243 specification. If there is no specification, return NULL_TREE. */
13245 static tree
13247 tree args,
13248 tsubst_flags_t complain,
13249 tree in_decl,
13251 {
13252 tree specs;
13253 tree new_specs;
13258 {
13259 /* A noexcept-specifier. */
13264 {
13265 /* Defer instantiation of noexcept-specifiers to avoid
13266 excessive instantiations (c++/49107). */
13269 {
13270 /* We already partially instantiated this member template,
13271 so combine the new args with the old. */
13276 }
13277 else
13278 {
13281 }
13282 }
13283 else
13284 new_specs = tsubst_copy_and_build
13288 }
13290 {
13293 else
13295 {
13296 tree spec;
13301 {
13302 /* Expand the pack expansion type. */
13305 in_decl);
13311 else
13312 {
13313 /* We're substituting into a member template, so
13314 we got a TYPE_PACK_EXPANSION back. Add that
13315 expansion and move on. */
13319 expanded_specs,
13320 complain);
13323 }
13324 }
13327 {
13330 else
13335 complain);
13336 }
13339 }
13340 }
13342 }
13344 /* Take the tree structure T and replace template parameters used
13345 therein with the argument vector ARGS. IN_DECL is an associated
13346 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
13347 Issue error and warning messages under control of COMPLAIN. Note
13348 that we must be relatively non-tolerant of extensions here, in
13349 order to preserve conformance; if we allow substitutions that
13350 should not be allowed, we may allow argument deductions that should
13351 not succeed, and therefore report ambiguous overload situations
13352 where there are none. In theory, we could allow the substitution,
13353 but indicate that it should have failed, and allow our caller to
13354 make sure that the right thing happens, but we don't try to do this
13355 yet.
13357 This function is used for dealing with types, decls and the like;
13358 for expressions, use tsubst_expr or tsubst_copy. */
13360 tree
13362 {
13385 else
13390 /* Reuse typedefs. We need to do this to handle dependent attributes,
13391 such as attribute aligned. */
13394 {
13398 {
13399 /* DECL represents an alias template and we want to
13400 instantiate it. */
13404 }
13408 {
13412 }
13417 else
13418 /* The typedef is from a non-template context. */
13422 {
13424 r = cp_build_qualified_type_real
13428 }
13429 else
13430 {
13431 /* We don't have an instantiation yet, so drop the typedef. */
13436 }
13437 }
13454 {
13480 {
13486 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
13487 needed. */
13493 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
13494 with TREE_SIDE_EFFECTS that indicates this is not an integral
13495 constant expression. */
13498 {
13501 }
13504 }
13510 {
13516 /* Early in template argument deduction substitution, we don't
13517 want to reduce the level of 'auto', or it will be confused
13518 with a normal template parm in subsequent deduction. */
13530 {
13534 {
13535 /* See through ARGUMENT_PACK_SELECT arguments. */
13537 /* If the selected argument is an expansion E, that most
13538 likely means we were called from
13539 gen_elem_of_pack_expansion_instantiation during the
13540 substituting of pack an argument pack (which Ith
13541 element is a pack expansion, where I is
13542 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13543 In this case, the Ith element resulting from this
13544 substituting is going to be a pack expansion, which
13545 pattern is the pattern of E. Let's return the
13546 pattern of E, and
13547 gen_elem_of_pack_expansion_instantiation will
13548 build the resulting pack expansion from it. */
13550 {
13551 /* Make sure we aren't throwing away arg info. */
13554 }
13555 }
13556 }
13561 {
13563 /* If ARG is an argument pack, we don't actually want to
13564 perform a substitution here, because substitutions
13565 for argument packs are only done
13566 element-by-element. We can get to this point when
13567 substituting the type of a non-type template
13568 parameter pack, when that type actually contains
13569 template parameter packs from an outer template, e.g.,
13571 template<typename... Types> struct A {
13572 template<Types... Values> struct B { };
13573 }; */
13577 {
13583 return cp_build_qualified_type_real
13585 }
13587 {
13588 /* We are processing a type constructed from a
13589 template template parameter. */
13600 /* Consider this code:
13602 template <template <class> class Template>
13603 struct Internal {
13604 template <class Arg> using Bind = Template<Arg>;
13605 };
13607 template <template <class> class Template, class Arg>
13608 using Instantiate = Template<Arg>; //#0
13610 template <template <class> class Template,
13611 class Argument>
13612 using Bind =
13613 Instantiate<Internal<Template>::template Bind,
13614 Argument>; //#1
13616 When #1 is parsed, the
13617 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13618 parameter `Template' in #0 matches the
13619 UNBOUND_CLASS_TEMPLATE representing the argument
13620 `Internal<Template>::template Bind'; We then want
13621 to assemble the type `Bind<Argument>' that can't
13622 be fully created right now, because
13623 `Internal<Template>' not being complete, the Bind
13624 template cannot be looked up in that context. So
13625 we need to "store" `Bind<Argument>' for later
13626 when the context of Bind becomes complete. Let's
13627 store that in a TYPENAME_TYPE. */
13631 argvec),
13632 typename_type,
13633 complain);
13635 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13636 are resolving nested-types in the signature of a
13637 member function templates. Otherwise ARG is a
13638 TEMPLATE_DECL and is the real template to be
13639 instantiated. */
13647 complain);
13648 return cp_build_qualified_type_real
13650 }
13653 else
13654 /* TEMPLATE_PARM_INDEX. */
13656 }
13659 /* This can happen during the attempted tsubst'ing in
13660 unify. This means that we don't yet have any information
13661 about the template parameter in question. */
13664 /* If we get here, we must have been looking at a parm for a
13665 more deeply nested template. Make a new version of this
13666 template parameter, but with a lower level. */
13668 {
13673 {
13675 r = cp_build_qualified_type_real
13679 }
13686 /* Break infinite recursion when substituting the constraints
13688 else
13689 {
13700 {
13701 /* Propagate constraints on placeholders. */
13706 {
13710 }
13711 }
13714 /* We have reduced the level of the template
13715 template parameter, but not the levels of its
13716 template parameters, so canonical_type_parameter
13717 will not be able to find the canonical template
13718 template parameter for this level. Thus, we
13719 require structural equality checking to compare
13720 TEMPLATE_TEMPLATE_PARMs. */
13724 else
13728 {
13730 /* We might need to substitute into the types of non-type
13731 template parameters. */
13743 }
13744 }
13748 /* OK, now substitute the type of the non-type parameter. We
13749 couldn't do it earlier because it might be an auto parameter,
13750 and we wouldn't need to if we had an argument. */
13757 }
13760 }
13763 {
13771 {
13775 }
13778 {
13782 }
13785 {
13789 }
13795 }
13798 /* We should never be tsubsting a binfo. */
13802 /* A vector of template arguments. */
13808 {
13812 /* [temp.deduct]
13814 Type deduction may fail for any of the following
13815 reasons:
13817 -- Attempting to create a pointer to reference type.
13818 -- Attempting to create a reference to a reference type or
13819 a reference to void.
13821 Core issue 106 says that creating a reference to a reference
13822 during instantiation is no longer a cause for failure. We
13823 only enforce this check in strict C++98 mode. */
13827 {
13830 /* We keep track of the last time we issued this error
13831 message to avoid spewing a ton of messages during a
13832 single bad template instantiation. */
13835 {
13840 else
13843 }
13846 }
13850 {
13852 {
13855 type);
13856 else
13858 type);
13859 }
13861 }
13863 {
13867 }
13869 /* In C++0x, during template argument substitution, when there is an
13870 attempt to create a reference to a reference type, reference
13871 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13873 "If a template-argument for a template-parameter T names a type
13874 that is a reference to a type A, an attempt to create the type
13875 'lvalue reference to cv T' creates the type 'lvalue reference to
13876 A,' while an attempt to create the type type rvalue reference to
13877 cv T' creates the type T"
13878 */
13879 r = cp_build_reference_type
13882 else
13887 /* Will this ever be needed for TYPE_..._TO values? */
13891 }
13893 {
13896 {
13897 /* [temp.deduct]
13899 Type deduction may fail for any of the following
13900 reasons:
13902 -- Attempting to create "pointer to member of T" when T
13903 is not a class type. */
13907 }
13909 {
13913 }
13915 {
13919 }
13922 {
13923 /* The type of the implicit object parameter gets its
13924 cv-qualifiers from the FUNCTION_TYPE. */
13925 tree memptr;
13926 tree method_type
13931 complain);
13932 }
13933 else
13936 complain);
13937 }
13940 {
13941 tree fntype;
13942 tree specs;
13947 /* Substitute the exception specification. */
13955 }
13957 {
13962 /* As an optimization, we avoid regenerating the array type if
13963 it will obviously be the same as T. */
13967 /* These checks should match the ones in create_array_type_for_decl.
13969 [temp.deduct]
13971 The deduction may fail for any of the following reasons:
13973 -- Attempting to create an array with an element type that
13974 is void, a function type, or a reference type, or [DR337]
13975 an abstract class type. */
13981 {
13985 }
13993 {
13996 }
13999 }
14002 {
14014 {
14018 }
14020 {
14021 /* Normally, make_typename_type does not require that the CTX
14022 have complete type in order to allow things like:
14024 template <class T> struct S { typename S<T>::X Y; };
14026 But, such constructs have already been resolved by this
14027 point, so here CTX really should have complete type, unless
14028 it's a partial instantiation. */
14031 {
14035 }
14036 }
14043 {
14046 }
14049 {
14051 {
14055 else
14057 }
14059 {
14063 else
14065 }
14066 }
14068 return cp_build_qualified_type_real
14070 }
14073 {
14085 }
14088 {
14089 tree type;
14105 complain);
14106 }
14109 {
14110 tree type;
14121 {
14123 {
14127 }
14130 }
14141 else
14142 {
14146 /* In a template ~id could be either a complement expression
14147 or an unqualified-id naming a destructor; if instantiating
14148 it produces an expression, it's not an id-expression or
14149 member access. */
14152 }
14157 }
14160 {
14164 }
14168 {
14169 tree r;
14173 else
14181 }
14196 /* We should use one of the expression tsubsts for these codes. */
14202 }
14203 }
14205 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
14206 type of the expression on the left-hand side of the "." or "->"
14207 operator. */
14209 static tree
14212 {
14213 tree name;
14214 tree qualifying_scope;
14215 tree fns;
14216 tree optype;
14221 /* A baselink indicates a function from a base class. Both the
14222 BASELINK_ACCESS_BINFO and the base class referenced may
14223 indicate bases of the template class, rather than the
14224 instantiated class. In addition, lookups that were not
14225 ambiguous before may be ambiguous now. Therefore, we perform
14226 the lookup again. */
14233 {
14240 }
14246 {
14248 {
14252 }
14254 }
14256 /* If lookup found a single function, mark it as used at this
14257 point. (If it lookup found multiple functions the one selected
14258 later by overload resolution will be marked as used at that
14259 point.) */
14266 /* Add back the template arguments, if present. */
14270 unknown_type_node,
14272 template_args);
14273 /* Update the conversion operator type. */
14281 {
14283 qualifying_scope,
14284 object_type);
14286 /* We need to call adjust_result_of_qualified_name_lookup in case the
14287 destructor names a base class, but we unset BASELINK_QUALIFIED_P
14288 so that we still get virtual function binding. */
14290 }
14292 }
14294 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
14295 true if the qualified-id will be a postfix-expression in-and-of
14296 itself; false if more of the postfix-expression follows the
14297 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
14298 of "&". */
14300 static tree
14304 {
14305 tree expr;
14306 tree scope;
14307 tree name;
14309 tree template_args;
14314 /* Figure out what name to look up. */
14317 {
14327 }
14328 else
14329 {
14332 }
14334 /* Substitute into the qualifying scope. When there are no ARGS, we
14335 are just trying to simplify a non-dependent expression. In that
14336 case the qualifying scope may be dependent, and, in any case,
14337 substituting will not help. */
14340 {
14343 }
14344 else
14348 {
14355 }
14358 {
14360 {
14361 /* A BIT_NOT_EXPR is used to represent a destructor. */
14363 {
14367 }
14368 else
14371 }
14372 else
14376 {
14378 {
14382 }
14384 }
14385 }
14388 {
14390 scope);
14391 /* Remember that there was a reference to this entity. */
14394 }
14397 {
14403 }
14406 {
14409 complain);
14410 else
14412 }
14418 {
14419 expr = (adjust_result_of_qualified_name_lookup
14421 expr = (finish_qualified_id_expr
14425 }
14427 /* Expressions do not generally have reference type. */
14429 /* However, if we're about to form a pointer-to-member, we just
14430 want the referenced member referenced. */
14438 }
14440 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
14441 initializer, DECL is the substituted VAR_DECL. Other arguments are as
14442 for tsubst. */
14444 static tree
14447 {
14454 {
14455 /* If we had an initializer but it
14456 instantiated to nothing,
14457 value-initialize the object. This will
14458 only occur when the initializer was a
14459 pack expansion where the parameter packs
14460 used in that expansion were of length
14461 zero. */
14463 complain);
14468 }
14471 }
14473 /* Like tsubst, but deals with expressions. This function just replaces
14474 template parms; to finish processing the resultant expression, use
14475 tsubst_copy_and_build or tsubst_expr. */
14477 static tree
14479 {
14481 tree r;
14489 {
14494 {
14495 /* We get here for a use of 'this' in an NSDMI as part of a
14496 constructor call or as part of an aggregate initialization. */
14498 && ((current_function_decl
14500 || (current_class_ref
14504 /* This can happen for a parameter name used later in a function
14505 declaration (such as in a late-specified return type). Just
14506 make a dummy decl, since it's only used for its type. */
14509 /* Give it the template pattern as its context; its true context
14510 hasn't been instantiated yet and this is good enough for
14511 mangling. */
14513 }
14522 {
14523 tree enum_type;
14524 tree v;
14528 /* There is no need to substitute into namespace-scope
14529 enumerators. */
14532 /* If ARGS is NULL, then T is known to be non-dependent. */
14536 /* Unfortunately, we cannot just call lookup_name here.
14537 Consider:
14539 template <int I> int f() {
14540 enum E { a = I };
14541 struct S { void g() { E e = a; } };
14542 };
14544 When we instantiate f<7>::S::g(), say, lookup_name is not
14545 clever enough to find f<7>::a. */
14546 enum_type
14556 /* We didn't find the name. That should never happen; if
14557 name-lookup found it during preliminary parsing, we
14558 should find it again here during instantiation. */
14560 }
14565 {
14566 /* Check for a local specialization set up by
14567 tsubst_pack_expansion. */
14569 {
14573 }
14575 /* When retrieving a capture pack from a generic lambda, remove the
14576 lambda call op's own template argument list from ARGS. Only the
14577 template arguments active for the closure type should be used to
14578 retrieve the pack specialization. */
14584 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14585 tsubst_decl put in the hash table. */
14587 }
14590 {
14591 tree ctx;
14596 {
14599 {
14603 }
14605 }
14606 }
14616 {
14619 {
14620 /* First try name lookup to find the instantiation. */
14623 {
14624 /* Make sure that the one we found is the one we want. */
14630 }
14634 else
14635 {
14636 /* This can happen for a variable used in a
14637 late-specified return type of a local lambda, or for a
14638 local static or constant. Building a new VAR_DECL
14639 should be OK in all those cases. */
14642 /* Avoid infinite recursion (79640). */
14645 {
14646 /* We can't call cp_finish_decl, so handle the
14647 initializer by hand. */
14658 }
14665 }
14666 /* Remember this for subsequent uses. */
14669 }
14670 }
14671 else
14681 /* An OVERLOAD will always be a non-dependent overload set; an
14682 overload set from function scope will just be represented with an
14683 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14685 /* We must have marked any lookups as persistent. */
14701 {
14702 /* Template template argument like the following example need
14703 special treatment:
14705 template <template <class> class TT> struct C {};
14706 template <class T> struct D {
14707 template <class U> struct E {};
14708 C<E> c; // #1
14709 };
14710 D<int> d; // #2
14712 We are processing the template argument `E' in #1 for
14713 the template instantiation #2. Originally, `E' is a
14714 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14715 have to substitute this with one having context `D<int>'. */
14719 {
14720 /* When rewriting a constructor into a deduction guide, a
14721 non-dependent name can become dependent, so memtmpl<args>
14722 becomes context::template memtmpl<args>. */
14726 }
14728 }
14729 else
14730 /* Ordinary template template argument. */
14741 {
14745 }
14750 {
14759 /* We only want to compute the number of arguments. */
14762 else
14769 {
14771 /* Set TREE_USED for the benefit of -Wunused. */
14775 }
14783 {
14788 else
14794 else
14797 }
14798 else
14800 }
14802 {
14810 }
14811 /* Fall through */
14827 {
14831 }
14834 {
14835 tree object;
14836 tree name;
14841 {
14845 }
14848 {
14858 }
14863 in_decl);
14864 else
14867 }
14905 {
14909 }
14912 {
14917 }
14920 {
14924 }
14927 {
14935 }
14941 {
14948 }
14951 {
14958 }
14961 {
14968 }
14971 {
14972 /* Substituted template arguments */
14981 }
14984 {
15004 }
15029 /* Fall through. */
15032 {
15035 }
15036 else
15040 /* This is handled by tsubst_copy_and_build. */
15044 {
15048 }
15051 /* We shouldn't have built any of these during initial template
15052 generation. Instead, they should be built during instantiation
15053 in response to the saved STMT_IS_FULL_EXPR_P setting. */
15057 {
15067 }
15085 {
15086 /* Instantiate any typedefs in the type. */
15091 }
15094 /* These can sometimes show up in a partial instantiation, but never
15095 involve template parms. */
15109 /* We shouldn't get here, but keep going if !flag_checking. */
15113 }
15114 }
15116 /* Helper function for tsubst_omp_clauses, used for instantiation of
15117 OMP_CLAUSE_DECL of clauses. */
15119 static tree
15121 tree in_decl)
15122 {
15126 /* Handle an OpenMP array section represented as a TREE_LIST (or
15127 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
15128 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
15129 TREE_LIST. We can handle it exactly the same as an array section
15130 (purpose, value, and a chain), even though the nomenclature
15131 (low_bound, length, etc) is different. */
15133 {
15134 tree low_bound
15140 in_decl);
15149 }
15152 /* Undo convert_from_reference tsubst_expr could have called. */
15158 }
15160 /* Like tsubst_copy, but specifically for OpenMP clauses. */
15162 static tree
15165 {
15170 {
15176 {
15179 {
15185 }
15186 /* FALLTHRU */
15201 in_decl);
15233 {
15236 {
15243 }
15244 else
15246 }
15249 in_decl);
15255 in_decl);
15263 in_decl);
15265 {
15268 }
15273 else
15276 in_decl,
15300 }
15303 {
15313 /* tsubst_expr on SCOPE_REF results in returning
15314 finish_non_static_data_member result. Undo that here. */
15318 {
15323 {
15327 CASE_CONVERT:
15336 /* FALLTHRU */
15340 }
15341 }
15347 {
15350 {
15353 }
15354 }
15358 }
15359 }
15363 {
15368 {
15371 }
15372 }
15374 }
15376 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
15378 static tree
15380 tree in_decl)
15381 {
15382 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
15402 {
15405 else
15406 {
15410 }
15411 }
15416 #undef RECUR
15417 }
15419 /* Used to temporarily communicate the list of #pragma omp parallel
15420 clauses to #pragma omp for instantiation if they are combined
15421 together. */
15425 /* Substitute one OMP_FOR iterator. */
15427 static void
15432 {
15433 #define RECUR(NODE) \
15434 tsubst_expr ((NODE), args, complain, in_decl, \
15435 integral_constant_expression_p)
15442 {
15445 }
15451 {
15452 /* We need to jump through some hoops to handle declarations in the
15453 init-statement, since we might need to handle auto deduction,
15454 but we need to keep control of initialization. */
15458 }
15459 else
15460 {
15462 {
15465 {
15469 {
15473 CASE_CONVERT:
15481 {
15484 }
15485 /* FALLTHRU */
15489 }
15490 }
15491 }
15492 else
15494 }
15505 {
15507 {
15508 /* Declare the variable, but don't let that initialize it. */
15513 }
15518 {
15523 }
15524 else
15531 }
15534 {
15535 /* Declare and initialize the variable. */
15538 }
15540 {
15544 {
15546 {
15552 {
15555 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15560 }
15563 {
15565 decl);
15567 }
15570 {
15572 decl);
15574 }
15575 else
15577 }
15580 }
15582 {
15587 {
15590 }
15591 }
15592 }
15595 {
15599 }
15600 else
15604 {
15615 {
15623 }
15624 else
15630 {
15636 }
15640 {
15648 }
15649 else
15655 }
15661 #undef RECUR
15662 }
15664 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15665 of OMP_TARGET's body. */
15667 static tree
15669 {
15672 {
15681 }
15683 }
15685 /* Helper function for tsubst_expr. For decomposition declaration
15686 artificial base DECL, which is tsubsted PATTERN_DECL, tsubst
15687 also the corresponding decls representing the identifiers
15688 of the decomposition declaration. Return DECL if successful
15689 or error_mark_node otherwise, set *FIRST to the first decl
15690 in the list chained through DECL_CHAIN and *CNT to the number
15691 of such decls. */
15693 static tree
15697 {
15702 decl2
15707 {
15709 {
15712 }
15729 {
15732 }
15733 else
15735 }
15738 }
15740 /* Like tsubst_copy for expressions, etc. but also does semantic
15741 processing. */
15743 tree
15746 {
15747 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15748 #define RECUR(NODE) \
15749 tsubst_expr ((NODE), args, complain, in_decl, \
15750 integral_constant_expression_p)
15753 tree r;
15754 location_t loc;
15766 {
15768 {
15769 tree_stmt_iterator i;
15773 }
15788 else
15798 {
15800 tree init;
15806 {
15816 else
15818 }
15820 {
15821 /* Don't build up decls for a variadic capture proxy, we'll
15822 instantiate the elements directly as needed. */
15824 }
15825 else
15826 {
15830 {
15831 /* By marking the declaration as instantiated, we avoid
15832 trying to instantiate it. Since instantiate_decl can't
15833 handle local variables, and since we've already done
15834 all that needs to be done, that's the right thing to
15835 do. */
15840 /* Anonymous aggregates are a special case. */
15843 {
15846 {
15850 }
15852 }
15858 {
15863 }
15864 else
15865 {
15870 {
15871 /* For __PRETTY_FUNCTION__ we have to adjust the
15872 initializer. */
15876 }
15877 else
15881 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15887 {
15889 tree first;
15895 }
15896 }
15897 }
15898 }
15901 }
15916 {
15924 {
15926 tree first;
15931 }
15932 else
15937 }
15963 else
15964 {
15971 }
15977 {
15986 }
15994 else
16002 else
16023 {
16030 }
16034 {
16036 tree label;
16043 }
16049 /* Computed goto's must be tsubst'd into. On the other hand,
16050 non-computed gotos must not be; the identifier in question
16051 will have no binding. */
16053 else
16059 {
16075 }
16080 {
16085 }
16086 else
16087 {
16092 else
16099 else
16105 else
16107 }
16111 {
16115 {
16117 /* Prevent instantiate_decl from trying to instantiate
16118 this variable. We've already done all that needs to be
16119 done. */
16122 }
16127 }
16133 {
16134 /* Local classes are not independent templates; they are
16135 instantiated along with their containing function. And this
16136 way we don't have to deal with pushing out of one local class
16137 to instantiate a member of another local class. */
16138 tree fn;
16139 /* Closures are handled by the LAMBDA_EXPR. */
16146 }
16150 {
16151 tree condition;
16154 condition =
16156 args,
16165 }
16171 in_decl);
16208 {
16223 in_decl);
16225 {
16232 }
16244 integral_constant_expression_p);
16255 else
16256 {
16264 }
16268 }
16273 /* FALLTHRU */
16280 in_decl);
16297 in_decl);
16308 {
16311 {
16312 /* For combined target teams, ensure the num_teams and
16313 thread_limit clause expressions are evaluated on the host,
16314 before entering the target construct. */
16315 tree c;
16321 {
16330 OMP_CLAUSE_FIRSTPRIVATE);
16334 }
16335 }
16336 }
16396 {
16401 {
16404 }
16410 }
16411 else
16412 {
16419 {
16422 }
16425 {
16430 {
16433 }
16439 }
16440 else
16441 {
16445 }
16448 }
16452 {
16458 {
16462 {
16467 }
16471 }
16472 else
16473 {
16478 }
16479 }
16483 {
16487 }
16507 /* If the first operand was a statement, we're done with it. */
16511 complain));
16523 integral_constant_expression_p));
16524 }
16527 out:
16530 #undef RECUR
16531 #undef RETURN
16532 }
16534 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
16535 function. For description of the body see comment above
16536 cp_parser_omp_declare_reduction_exprs. */
16538 static void
16540 {
16546 tree_stmt_iterator tsi;
16557 {
16576 }
16578 {
16598 }
16599 }
16601 /* T is a postfix-expression that is not being used in a function
16602 call. Return the substituted version of T. */
16604 static tree
16606 tsubst_flags_t complain,
16607 tree in_decl)
16608 {
16612 else
16618 }
16620 /* Like tsubst but deals with expressions and performs semantic
16621 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
16623 tree
16625 tree args,
16626 tsubst_flags_t complain,
16627 tree in_decl,
16630 {
16631 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
16632 #define RECUR(NODE) \
16633 tsubst_copy_and_build (NODE, args, complain, in_decl, \
16635 integral_constant_expression_p)
16638 location_t loc;
16647 /* N3276 decltype magic only applies to calls at the top level or on the
16648 right side of a comma. */
16653 {
16656 /* Fall through. */
16658 {
16659 tree decl;
16660 cp_id_kind idk;
16665 {
16668 }
16670 /* Look up the name. */
16673 /* By convention, expressions use ERROR_MARK_NODE to indicate
16674 failure, not NULL_TREE. */
16680 integral_constant_expression_p,
16688 input_location);
16692 {
16696 }
16698 }
16701 {
16702 tree object;
16712 {
16717 }
16723 {
16726 }
16727 else
16734 else
16736 }
16739 {
16743 {
16744 /* A type conversion to reference type will be enclosed in
16745 such an indirect ref, but the substitution of the cast
16746 will have also added such an indirect ref. */
16749 }
16750 else
16758 }
16761 {
16765 }
16768 {
16775 flags));
16776 }
16779 {
16783 }
16790 {
16791 tree type;
16797 {
16802 }
16808 {
16826 }
16829 }
16863 else
16865 in_decl);
16900 {
16907 tree r = build_x_binary_op
16909 op0,
16911 ? ERROR_MARK
16913 op1,
16915 ? ERROR_MARK
16923 }
16926 {
16930 }
16943 {
16952 }
16957 /* Fall through */
16960 {
16961 tree r;
16967 {
16968 /* When there are no ARGS, we are trying to evaluate a
16969 non-dependent expression from the parser. Trying to do
16970 the substitutions may not work. */
16973 }
16974 else
16975 {
16980 else
16983 /*integral_constant_expression_p=*/
16987 }
16991 else
16995 {
16997 {
16999 {
17003 }
17004 else
17008 }
17010 }
17012 }
17015 {
17025 }
17041 {
17045 tree r = build_x_modify_expr
17048 /* TREE_NO_WARNING must be set if either the expression was
17049 parenthesized or it uses an operator such as >>= rather
17050 than plain assignment. In the former case, it was already
17051 set and must be copied. In the latter case,
17052 build_x_modify_expr sets it and it must not be reset
17053 here. */
17058 }
17063 /* Remember that there was a reference to this entity. */
17070 {
17075 tree ret;
17079 else
17080 {
17084 }
17086 /* If there was an initializer in the original tree, but it
17087 instantiated to an empty list, then we should pass a
17088 non-NULL empty vector to tell build_new that it was an
17089 empty initializer() rather than no initializer. This can
17090 only happen when the initializer is a pack expansion whose
17091 parameter packs are of length zero. */
17094 else
17095 {
17099 else
17100 {
17103 }
17104 }
17110 complain);
17118 }
17121 {
17127 complain));
17128 }
17131 {
17135 integral_constant_expression_p);
17137 op0,
17140 }
17143 {
17144 tree function;
17149 tree ret;
17152 /* Internal function with no arguments. */
17156 /* When we parsed the expression, we determined whether or
17157 not Koenig lookup should be performed. */
17160 {
17163 }
17165 {
17170 }
17172 {
17173 /* Do nothing; calling tsubst_copy_and_build on an identifier
17174 would incorrectly perform unqualified lookup again.
17176 Note that we can also have an IDENTIFIER_NODE if the earlier
17177 unqualified lookup found a member function; in that case
17178 koenig_p will be false and we do want to do the lookup
17179 again to find the instantiated member function.
17181 FIXME but doing that causes c++/15272, so we need to stop
17182 using IDENTIFIER_NODE in that situation. */
17184 }
17185 else
17186 {
17188 {
17194 }
17195 else
17200 /* Avoid error about taking the address of a constructor. */
17204 in_decl,
17206 integral_constant_expression_p);
17210 }
17215 {
17220 else
17221 {
17222 /* Expand the pack expansion and push each entry onto
17223 CALL_ARGS. */
17226 {
17231 {
17236 }
17237 }
17238 else
17239 {
17240 /* A partial substitution. Add one entry. */
17242 }
17243 }
17244 }
17246 /* We do not perform argument-dependent lookup if normal
17247 lookup finds a non-function, in accordance with the
17248 expected resolution of DR 218. */
17251 /* If lookup found a member function, the Koenig lookup is
17252 not appropriate, even if an unqualified-name was used
17253 to denote the function. */
17256 /* Only do this when substitution turns a dependent call
17257 into a non-dependent call. */
17265 {
17267 {
17268 /* For backwards compatibility and good diagnostics, try
17269 the unqualified lookup again if we aren't in SFINAE
17270 context. */
17271 tree unq = (tsubst_copy_and_build
17273 integral_constant_expression_p));
17275 {
17278 }
17281 {
17282 /* In a lambda fn, we have to be careful to not
17283 introduce new this captures. Legacy code can't
17284 be using lambdas anyway, so it's ok to be
17285 stricter. */
17290 "and no declarations were found by "
17291 "argument-dependent lookup at the point "
17298 else
17302 {
17313 {
17315 input_location);
17317 "declarations in dependent base %qT are "
17323 else
17327 }
17328 else
17330 "%qD declared here, later in the "
17333 {
17336 }
17337 }
17340 }
17341 }
17343 {
17348 }
17349 }
17351 /* Remember that there was a reference to this entity. */
17355 {
17358 }
17360 /* Put back tf_decltype for the actual call. */
17365 {
17369 {
17371 "wrong number of arguments to "
17374 }
17375 else
17377 input_location),
17382 /* Unsupported internal function with arguments. */
17384 }
17387 complain);
17389 {
17404 complain);
17405 else
17406 ret = (build_new_method_call
17411 complain));
17412 }
17413 else
17416 koenig_p,
17417 complain);
17422 {
17428 {
17434 {
17436 /* The thunk location is not interesting. */
17438 }
17439 }
17440 }
17443 }
17446 {
17452 {
17454 {
17459 }
17460 else
17461 {
17466 }
17468 }
17469 else
17470 {
17473 }
17477 }
17480 {
17485 input_location));
17486 }
17489 {
17497 {
17498 /* We have pack expansions, so expand those and
17499 create a new list out of it. */
17502 tree chain;
17505 /* Expand the argument expressions. */
17513 /* Build the rest of the list. */
17518 /* Determine the number of arguments. */
17520 {
17523 }
17526 else
17527 {
17528 /* Since we only performed a partial substitution into
17529 the argument pack, we only RETURN (a single list
17530 node. */
17537 }
17539 /* Convert the argument vectors into a TREE_LIST */
17542 {
17543 /* Grab the Ith values. */
17544 i--;
17547 value
17551 /* Build the list (backwards). */
17553 }
17556 }
17572 }
17575 {
17576 tree object;
17577 tree object_type;
17578 tree member;
17579 tree r;
17583 /* Remember that there was a reference to this entity. */
17594 else
17600 {
17605 }
17609 {
17611 {
17616 {
17619 }
17621 {
17626 }
17627 }
17628 }
17631 {
17632 /* Lookup the template functions now that we know what the
17633 scope is. */
17641 {
17644 args);
17645 member = (adjust_result_of_qualified_name_lookup
17647 object_type));
17648 }
17649 else
17650 {
17652 input_location);
17654 }
17655 }
17659 {
17661 {
17665 else
17668 }
17670 }
17674 complain);
17678 }
17685 {
17693 tree r;
17698 /* digest_init will do the wrong thing if we let it. */
17702 /* We do not want to process the index of aggregate
17703 initializers as they are identifier nodes which will be
17704 looked up by digest_init. */
17710 {
17712 /* An identifier index is looked up in the type
17713 being initialized, not the current scope. */
17718 {
17719 /* Substitute into the pack expansion. */
17721 in_decl);
17725 ;
17727 /* Just move the argument into place. */
17729 else
17730 {
17731 /* Update the length of the final CONSTRUCTOR
17732 arguments vector, and note that we will need to
17733 copy.*/
17736 }
17737 }
17738 else
17740 }
17743 {
17748 {
17750 {
17755 }
17756 else
17758 }
17759 }
17765 {
17770 }
17774 }
17777 {
17780 {
17783 }
17784 else
17785 {
17788 }
17789 }
17795 {
17796 /* We don't build decls for an instantiation of a
17797 variadic capture proxy, we instantiate the elements
17798 when needed. */
17801 }
17802 /* Fall through */
17805 {
17807 /* ??? We're doing a subset of finish_id_expression here. */
17809 && !processing_template_decl
17810 && !cp_unevaluated_operand
17813 {
17815 /* Replace an evaluated use of the thread_local variable with
17816 a call to its wrapper. */
17818 }
17820 {
17824 }
17827 /* If the original type was a reference, we'll be wrapped in
17828 the appropriate INDIRECT_REF. */
17831 }
17834 {
17838 }
17841 {
17842 tree object_ptr
17849 }
17856 {
17867 }
17870 {
17876 integral_constant_expression_p);
17880 /* If the resulting list of expression statement is empty,
17881 fold it further into void_node. */
17886 }
17889 {
17907 /* For a function or variable scope, we want to use tsubst so that we
17908 don't complain about referring to an auto before deduction. */
17911 {
17912 /* Look up the parameter we want directly, as tsubst_copy
17913 doesn't do what we need. */
17919 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17922 }
17924 /* For a field, use tsubst_copy so that we look up the existing field
17925 rather than build a new one. */
17927 else
17934 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17936 /* Now that we know visibility, instantiate the type so we have a
17937 declaration of the op() for later calls to lambda_function. */
17948 }
17951 /* We can get here for a constant initializer of non-dependent type.
17952 FIXME stop folding in cp_parser_initializer_clause. */
17953 {
17955 complain);
17957 }
17961 integral_constant_expression_p));
17967 {
17972 complain));
17973 }
17979 /* Handle Objective-C++ constructs, if appropriate. */
17980 {
17981 tree subst
17986 }
17988 }
17990 #undef RECUR
17991 #undef RETURN
17992 out:
17995 }
17997 /* Verify that the instantiated ARGS are valid. For type arguments,
17998 make sure that the type's linkage is ok. For non-type arguments,
17999 make sure they are constants if they are integral or enumerations.
18000 Emit an error under control of COMPLAIN, and return TRUE on error. */
18002 static bool
18004 {
18008 {
18018 }
18020 {
18021 /* [basic.link]: A name with no linkage (notably, the name
18022 of a class or enumeration declared in a local scope)
18023 shall not be used to declare an entity with linkage.
18024 This implies that names with no linkage cannot be used as
18025 template arguments
18027 DR 757 relaxes this restriction for C++0x. */
18032 {
18033 /* DR 488 makes use of a type with no linkage cause
18034 type deduction to fail. */
18036 {
18039 else
18042 }
18044 }
18045 /* In order to avoid all sorts of complications, we do not
18046 allow variably-modified types as template arguments. */
18048 {
18052 }
18053 }
18054 /* Class template and alias template arguments should be OK. */
18056 ;
18057 /* A non-type argument of integral or enumerated type must be a
18058 constant. */
18063 {
18067 }
18069 }
18071 static bool
18073 {
18078 {
18081 }
18085 }
18087 /* We're out of SFINAE context now, so generate diagnostics for the access
18088 errors we saw earlier when instantiating D from TMPL and ARGS. */
18090 static void
18092 {
18104 }
18106 /* Instantiate the indicated variable, function, or alias template TMPL with
18107 the template arguments in TARG_PTR. */
18109 static tree
18111 {
18113 tree fndecl;
18114 tree gen_tmpl;
18115 tree spec;
18123 /* If this function is a clone, handle it specially. */
18125 {
18126 tree spec;
18127 tree clone;
18129 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
18130 DECL_CLONED_FUNCTION. */
18136 /* Look for the clone. */
18140 /* We should always have found the clone by now. */
18143 }
18148 /* Check to see if we already have this specialization. */
18152 /* targ_ptr only has the innermost template args, so add the outer ones
18153 from tmpl, which could be either a partial instantiation or gen_tmpl (in
18154 the case of a non-dependent call within a template definition). */
18155 targ_ptr = (add_outermost_template_args
18157 targ_ptr));
18159 /* It would be nice to avoid hashing here and then again in tsubst_decl,
18160 but it doesn't seem to be on the hot path. */
18169 {
18171 {
18175 }
18177 }
18180 complain))
18183 /* We are building a FUNCTION_DECL, during which the access of its
18184 parameters and return types have to be checked. However this
18185 FUNCTION_DECL which is the desired context for access checking
18186 is not built yet. We solve this chicken-and-egg problem by
18187 deferring all checks until we have the FUNCTION_DECL. */
18190 /* Instantiation of the function happens in the context of the function
18191 template, not the context of the overload resolution we're doing. */
18193 /* If there are dependent arguments, e.g. because we're doing partial
18194 ordering, make sure processing_template_decl stays set. */
18198 {
18202 }
18208 {
18209 /* We need to determine if we're using a partial or explicit
18210 specialization now, because the type of the variable could be
18211 different. */
18217 {
18222 }
18223 }
18225 /* Substitute template parameters to obtain the specialization. */
18233 {
18236 }
18238 /* The DECL_TI_TEMPLATE should always be the immediate parent
18239 template, not the most general template. */
18243 /* Now we know the specialization, compute access previously
18244 deferred. Do no access control for inheriting constructors,
18245 as we already checked access for the inherited constructor. */
18248 {
18253 }
18256 /* If we've just instantiated the main entry point for a function,
18257 instantiate all the alternate entry points as well. We do this
18258 by cloning the instantiation of the main entry point, not by
18259 instantiating the template clones. */
18264 {
18266 {
18267 /* Remember to reinstantiate when we're out of SFINAE so the user
18268 can see the errors. */
18270 }
18272 }
18274 }
18276 /* Wrapper for instantiate_template_1. */
18278 tree
18280 {
18281 tree ret;
18286 }
18288 /* Instantiate the alias template TMPL with ARGS. Also push a template
18289 instantiation level, which instantiate_template doesn't do because
18290 functions and variables have sufficient context established by the
18291 callers. */
18293 static tree
18295 {
18302 {
18305 }
18307 args =
18315 /* We can't free this if a pending_template entry or last_error_tinst_level
18316 is pointing at it. */
18322 }
18324 /* PARM is a template parameter pack for FN. Returns true iff
18325 PARM is used in a deducible way in the argument list of FN. */
18327 static bool
18329 {
18332 {
18334 tree packs;
18340 {
18341 /* The template parameter pack is used in a function parameter
18342 pack. If this is the end of the parameter list, the
18343 template parameter pack is deducible. */
18346 else
18347 /* Otherwise, not. Well, it could be deduced from
18348 a non-pack parameter, but doing so would end up with
18349 a deduction mismatch, so don't bother. */
18351 }
18352 }
18353 /* The template parameter pack isn't used in any function parameter
18354 packs, but it might be used deeper, e.g. tuple<Args...>. */
18356 }
18358 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
18359 NARGS elements of the arguments that are being used when calling
18360 it. TARGS is a vector into which the deduced template arguments
18361 are placed.
18363 Returns either a FUNCTION_DECL for the matching specialization of FN or
18364 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
18365 true, diagnostics will be printed to explain why it failed.
18367 If FN is a conversion operator, or we are trying to produce a specific
18368 specialization, RETURN_TYPE is the return type desired.
18370 The EXPLICIT_TARGS are explicit template arguments provided via a
18371 template-id.
18373 The parameter STRICT is one of:
18375 DEDUCE_CALL:
18376 We are deducing arguments for a function call, as in
18377 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
18378 deducing arguments for a call to the result of a conversion
18379 function template, as in [over.call.object].
18381 DEDUCE_CONV:
18382 We are deducing arguments for a conversion function, as in
18383 [temp.deduct.conv].
18385 DEDUCE_EXACT:
18386 We are deducing arguments when doing an explicit instantiation
18387 as in [temp.explicit], when determining an explicit specialization
18388 as in [temp.expl.spec], or when taking the address of a function
18389 template, as in [temp.deduct.funcaddr]. */
18391 tree
18393 tree explicit_targs,
18394 tree targs,
18397 tree return_type,
18398 unification_kind_t strict,
18402 {
18403 tree parms;
18404 tree fntype;
18417 tree tinst;
18423 full_targs = (add_outermost_template_args
18425 targs));
18430 /* In C++0x, it's possible to have a function template whose type depends
18431 on itself recursively. This is most obvious with decltype, but can also
18432 occur with enumeration scope (c++/48969). So we need to catch infinite
18433 recursion and reject the substitution at deduction time; this function
18434 will return error_mark_node for any repeated substitution.
18436 This also catches excessive recursion such as when f<N> depends on
18437 f<N-1> across all integers, and returns error_mark_node for all the
18438 substitutions back up to the initial one.
18440 This is, of course, not reentrant. */
18450 {
18451 /* [temp.deduct]
18453 The specified template arguments must match the template
18454 parameters in kind (i.e., type, nontype, template), and there
18455 must not be more arguments than there are parameters;
18456 otherwise type deduction fails.
18458 Nontype arguments must match the types of the corresponding
18459 nontype template parameters, or must be convertible to the
18460 types of the corresponding nontype parameters as specified in
18461 _temp.arg.nontype_, otherwise type deduction fails.
18463 All references in the function type of the function template
18464 to the corresponding template parameters are replaced by the
18465 specified template argument values. If a substitution in a
18466 template parameter or in the function type of the function
18467 template results in an invalid type, type deduction fails. */
18478 explicit_targs);
18480 /* Adjust any explicit template arguments before entering the
18481 substitution context. */
18482 explicit_targs
18484 complain,
18490 /* Substitute the explicit args into the function type. This is
18491 necessary so that, for instance, explicitly declared function
18492 arguments can match null pointed constants. If we were given
18493 an incomplete set of explicit args, we must not do semantic
18494 processing during substitution as we could create partial
18495 instantiations. */
18497 {
18502 /* Dig out the actual parm. */
18505 {
18508 }
18510 {
18513 }
18516 /* No explicit argument for this template parameter. */
18520 {
18521 /* Mark the argument pack as "incomplete". We could
18522 still deduce more arguments during unification.
18523 We remove this mark in type_unification_real. */
18525 {
18529 }
18531 /* We have some incomplete argument packs. */
18533 }
18534 }
18538 {
18541 }
18544 /* Ignore any access checks; we'll see them again in
18545 instantiate_template and they might have the wrong
18546 access path at this point. */
18558 /* Place the explicitly specified arguments in TARGS. */
18562 }
18564 /* Never do unification on the 'this' parameter. */
18568 {
18569 /* We're deducing for a call to the result of a template conversion
18570 function. The parms we really want are in return_type. */
18574 }
18576 {
18585 }
18587 /* We allow incomplete unification without an error message here
18588 because the standard doesn't seem to explicitly prohibit it. Our
18589 callers must be ready to deal with unification failures in any
18590 event. */
18593 /* If we aren't explaining yet, push tinst context so we can see where
18594 any errors (e.g. from class instantiations triggered by instantiation
18595 of default template arguments) come from. If we are explaining, this
18596 context is redundant. */
18598 {
18601 }
18603 /* type_unification_real will pass back any access checks from default
18604 template argument substitution. */
18616 /* Now that we have bindings for all of the template arguments,
18617 ensure that the arguments deduced for the template template
18618 parameters have compatible template parameter lists. We cannot
18619 check this property before we have deduced all template
18620 arguments, because the template parameter types of a template
18621 template parameter might depend on prior template parameters
18622 deduced after the template template parameter. The following
18623 ill-formed example illustrates this issue:
18625 template<typename T, template<T> class C> void f(C<5>, T);
18627 template<int N> struct X {};
18629 void g() {
18630 f(X<5>(), 5l); // error: template argument deduction fails
18631 }
18633 The template parameter list of 'C' depends on the template type
18634 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
18635 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
18636 time that we deduce 'C'. */
18639 {
18642 }
18644 /* All is well so far. Now, check:
18646 [temp.deduct]
18648 When all template arguments have been deduced, all uses of
18649 template parameters in nondeduced contexts are replaced with
18650 the corresponding deduced argument values. If the
18651 substitution results in an invalid type, as described above,
18652 type deduction fails. */
18655 {
18658 }
18660 /* Also collect access checks from the instantiation. */
18673 /* Now perform any access checks encountered during substitution. */
18680 /* If we're looking for an exact match, check that what we got
18681 is indeed an exact match. It might not be if some template
18682 parameters are used in non-deduced contexts. But don't check
18683 for an exact match if we have dependent template arguments;
18684 in that case we're doing partial ordering, and we already know
18685 that we have two candidates that will provide the actual type. */
18687 {
18691 tree sarg
18697 {
18701 }
18702 }
18704 /* After doing deduction with the inherited constructor, actually return an
18705 instantiation of the inheriting constructor. */
18711 fail:
18714 {
18716 /* Reset once we're all the way out. */
18718 }
18720 /* We can't free this if a pending_template entry or last_error_tinst_level
18721 is pointing at it. */
18727 }
18729 /* Adjust types before performing type deduction, as described in
18730 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
18731 sections are symmetric. PARM is the type of a function parameter
18732 or the return type of the conversion function. ARG is the type of
18733 the argument passed to the call, or the type of the value
18734 initialized with the result of the conversion function.
18735 ARG_EXPR is the original argument expression, which may be null. */
18737 static int
18741 tree arg_expr)
18742 {
18746 {
18751 /* Swap PARM and ARG throughout the remainder of this
18752 function; the handling is precisely symmetric since PARM
18753 will initialize ARG rather than vice versa. */
18758 /* Core issue #873: Do the DR606 thing (see below) for these cases,
18759 too, but here handle it by stripping the reference from PARM
18760 rather than by adding it to ARG. */
18768 /* Nothing else to do in this case. */
18773 }
18776 {
18777 /* [temp.deduct.call]
18779 If P is not a reference type:
18781 --If A is an array type, the pointer type produced by the
18782 array-to-pointer standard conversion (_conv.array_) is
18783 used in place of A for type deduction; otherwise,
18785 --If A is a function type, the pointer type produced by
18786 the function-to-pointer standard conversion
18787 (_conv.func_) is used in place of A for type deduction;
18788 otherwise,
18790 --If A is a cv-qualified type, the top level
18791 cv-qualifiers of A's type are ignored for type
18792 deduction. */
18797 else
18799 }
18801 /* [14.8.2.1/3 temp.deduct.call], "A forwarding reference is an rvalue
18802 reference to a cv-unqualified template parameter that does not represent a
18803 template parameter of a class template (during class template argument
18804 deduction (13.3.1.8)). If P is a forwarding reference and the argument is
18805 an lvalue, the type "lvalue reference to A" is used in place of A for type
18806 deduction. */
18813 /* try_one_overload doesn't provide an arg_expr, but
18814 functions are always lvalues. */
18818 /* [temp.deduct.call]
18820 If P is a cv-qualified type, the top level cv-qualifiers
18821 of P's type are ignored for type deduction. If P is a
18822 reference type, the type referred to by P is used for
18823 type deduction. */
18826 {
18829 }
18831 /* DR 322. For conversion deduction, remove a reference type on parm
18832 too (which has been swapped into ARG). */
18837 }
18839 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18840 template which does contain any deducible template parameters; check if
18841 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18842 unify_one_argument. */
18844 static int
18847 {
18848 tree type;
18852 else
18859 {
18863 }
18865 {
18870 }
18874 else
18876 }
18880 /* Returns true iff the expression EXPR is one from which a template
18881 argument can be deduced. In other words, if it's an undecorated
18882 use of a template non-type parameter. */
18884 static bool
18886 {
18887 /* Strip implicit conversions. */
18891 }
18893 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18894 deducible way; that is, if it has a max value of <PARM> - 1. */
18896 static bool
18898 {
18907 }
18909 /* Returns true iff the template arguments ARGS use a template parameter
18910 in a deducible way. */
18912 static bool
18914 {
18916 {
18921 else
18922 {
18929 else
18931 }
18934 }
18936 }
18938 /* Returns true iff TYPE contains any deducible references to template
18939 parameters, as per 14.8.2.5. */
18941 static bool
18943 {
18947 /* T
18948 cv-list T
18949 TT<T>
18950 TT<i>
18951 TT<> */
18956 /* T*
18957 T&
18958 T&& */
18962 /* T[integer-constant ]
18963 type [i] */
18968 /* T type ::*
18969 type T::*
18970 T T::*
18971 T (type ::*)()
18972 type (T::*)()
18973 type (type ::*)(T)
18974 type (T::*)(T)
18975 T (type ::*)(T)
18976 T (T::*)()
18977 T (T::*)(T) */
18980 || (uses_deducible_template_parms
18983 /* template-name <T> (where template-name refers to a class template)
18984 template-name <i> (where template-name refers to a class template) */
18991 /* type (T)
18992 T()
18993 T(T) */
18996 {
19005 }
19008 }
19010 /* Subroutine of type_unification_real and unify_pack_expansion to
19011 handle unification of a single P/A pair. Parameters are as
19012 for those functions. */
19014 static int
19018 {
19025 /* We can't deduce anything from this, but we might get all the
19026 template args from other function args. */
19029 /* Implicit conversions (Clause 4) will be performed on a function
19030 argument to convert it to the type of the corresponding function
19031 parameter if the parameter type contains no template-parameters that
19032 participate in template argument deduction. */
19035 /* For function parameters with no deducible template parameters,
19036 just return. We'll check non-dependent conversions later. */
19040 {
19042 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
19043 | UNIFY_ALLOW_MORE_CV_QUAL
19057 }
19059 /* We only do these transformations if this is the top-level
19060 parameter_type_list in a call or declaration matching; in other
19061 situations (nested function declarators, template argument lists) we
19062 won't be comparing a type to an expression, and we don't do any type
19063 adjustments. */
19065 {
19067 {
19070 {
19071 /* [temp.deduct.type] A template-argument can be
19072 deduced from a pointer to function or pointer
19073 to member function argument if the set of
19074 overloaded functions does not contain function
19075 templates and at most one of a set of
19076 overloaded functions provides a unique
19077 match. */
19084 }
19090 }
19092 arg_strict |=
19094 }
19095 else
19100 /* For deduction from an init-list we need the actual list. */
19104 }
19106 /* for_each_template_parm callback that always returns 0. */
19108 static int
19110 {
19112 }
19114 /* for_each_template_parm any_fn callback to handle deduction of a template
19115 type argument from the type of an array bound. */
19117 static int
19119 {
19127 {
19133 }
19135 /* Keep walking. */
19137 }
19139 /* Try to deduce any not-yet-deduced template type arguments from the type of
19140 an array bound. This is handled separately from unify because 14.8.2.5 says
19141 "The type of a type parameter is only deduced from an array bound if it is
19142 not otherwise deduced." */
19144 static void
19146 {
19151 }
19153 /* Most parms like fn_type_unification.
19155 If SUBR is 1, we're being called recursively (to unify the
19156 arguments of a function or method parameter of a function
19157 template).
19159 CHECKS is a pointer to a vector of access checks encountered while
19160 substituting default template arguments. */
19162 static int
19164 tree full_targs,
19165 tree xparms,
19169 unification_kind_t strict,
19173 {
19178 tree parms;
19189 /* Reset the number of non-defaulted template arguments contained
19190 in TARGS. */
19193 again:
19201 {
19206 /* For a function parameter pack that occurs at the end of the
19207 parameter-declaration-list, the type A of each remaining
19208 argument of the call is compared with the type P of the
19209 declarator-id of the function parameter pack. */
19215 /* For a function parameter pack that does not occur at the
19216 end of the parameter-declaration-list, the type of the
19217 parameter pack is a non-deduced context. */
19224 explain_p))
19226 }
19231 {
19232 /* Unify the remaining arguments with the pack expansion type. */
19233 tree argvec;
19236 /* Allocate a TREE_VEC and copy in all of the arguments */
19241 /* Copy the parameter into parmvec. */
19247 /* Advance to the end of the list of parameters. */
19249 }
19251 /* Fail if we've reached the end of the parm list, and more args
19252 are present, and the parm list isn't variadic. */
19255 /* Fail if parms are left and they don't have default values and
19256 they aren't all deduced as empty packs (c++/57397). This is
19257 consistent with sufficient_parms_p. */
19260 {
19264 do
19265 {
19268 count++;
19270 }
19274 type_pack_p);
19275 }
19278 {
19279 tsubst_flags_t complain = (explain_p
19280 ? tf_warning_or_error
19285 {
19289 /* Clear the "incomplete" flags on all argument packs now so that
19290 substituting them into later default arguments works. */
19292 {
19295 }
19303 {
19308 }
19310 /* If this is an undeduced nontype parameter that depends on
19311 a type parameter, try another pass; its type may have been
19312 deduced from a later argument than the one from which
19313 this parameter can be deduced. */
19317 {
19320 }
19322 /* Core issue #226 (C++0x) [temp.deduct]:
19324 If a template argument has not been deduced, its
19325 default template argument, if any, is used.
19327 When we are in C++98 mode, TREE_PURPOSE will either
19328 be NULL_TREE or ERROR_MARK_NODE, so we do not need
19329 to explicitly check cxx_dialect here. */
19331 /* OK, there is a default argument. Wait until after the
19332 conversion check to do substitution. */
19335 /* If the type parameter is a parameter pack, then it will
19336 be deduced to an empty parameter pack. */
19338 {
19339 tree arg;
19342 {
19345 }
19346 else
19353 }
19356 }
19358 /* DR 1391: All parameters have args, now check non-dependent parms for
19359 convertibility. */
19363 {
19369 /* For a function parameter pack that occurs at the end of the
19370 parameter-declaration-list, the type A of each remaining
19371 argument of the call is compared with the type P of the
19372 declarator-id of the function parameter pack. */
19378 /* For a function parameter pack that does not occur at the
19379 end of the parameter-declaration-list, the type of the
19380 parameter pack is a non-deduced context. */
19389 explain_p))
19391 }
19393 /* Now substitute into the default template arguments. */
19395 {
19419 else
19427 {
19429 /* The position of the first default template argument,
19430 is also the number of non-defaulted arguments in TARGS.
19431 Record that. */
19434 }
19435 }
19439 }
19445 }
19447 /* Subroutine of type_unification_real. Args are like the variables
19448 at the call site. ARG is an overloaded function (or template-id);
19449 we try deducing template args from each of the overloads, and if
19450 only one succeeds, we go with that. Modifies TARGS and returns
19451 true on success. */
19453 static bool
19455 tree targs,
19456 tree parm,
19457 tree arg,
19458 unification_kind_t strict,
19461 {
19468 {
19471 }
19472 else
19476 /* Handle `&x' where `x' is some static or non-static member
19477 function name. */
19483 /* Strip baselink information. */
19488 {
19489 /* If we got some explicit template args, we need to plug them into
19490 the affected templates before we try to unify, in case the
19491 explicit args will completely resolve the templates in question. */
19498 {
19511 {
19516 {
19519 }
19520 }
19523 }
19524 /* If no templates (or more than one) are fully resolved by the
19525 explicit arguments, this template-id is a non-deduced context; it
19526 could still be OK if we deduce all template arguments for the
19527 enclosing call through other arguments. */
19530 }
19533 /* If ARG is, for example, "(0, &f)" then its type will be unknown
19534 -- but the deduction does not succeed because the expression is
19535 not just the function on its own. */
19537 else
19539 {
19544 {
19547 }
19548 }
19550 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19551 to function or pointer to member function argument if the set of
19552 overloaded functions does not contain function templates and at most
19553 one of a set of overloaded functions provides a unique match.
19555 So if we found multiple possibilities, we return success but don't
19556 deduce anything. */
19559 {
19563 {
19568 /* Don't forget explicit template arguments in a pack. */
19572 }
19573 }
19578 }
19580 /* Core DR 115: In contexts where deduction is done and fails, or in
19581 contexts where deduction is not done, if a template argument list is
19582 specified and it, along with any default template arguments, identifies
19583 a single function template specialization, then the template-id is an
19584 lvalue for the function template specialization. */
19586 tree
19588 {
19601 {
19604 }
19606 {
19609 }
19611 {
19614 }
19617 {
19621 /* If we got some explicit template args, we need to plug them into
19622 the affected templates before we try to unify, in case the
19623 explicit args will completely resolve the templates in question. */
19631 {
19644 {
19647 {
19650 }
19652 {
19655 }
19656 }
19657 }
19659 {
19667 {
19668 tree base
19671 }
19675 }
19677 /* There were no good options and at least one bad one, so let the
19678 user know what the problem is. */
19680 }
19682 }
19684 /* Subroutine of resolve_overloaded_unification; does deduction for a single
19685 overload. Fills TARGS with any deduced arguments, or error_mark_node if
19686 different overloads deduce different arguments for a given parm.
19687 ADDR_P is true if the expression for which deduction is being
19688 performed was of the form "& fn" rather than simply "fn".
19690 Returns 1 on success. */
19692 static int
19694 tree orig_targs,
19695 tree targs,
19696 tree parm,
19697 tree arg,
19698 unification_kind_t strict,
19702 {
19704 tree tempargs;
19710 /* [temp.deduct.type] A template-argument can be deduced from a pointer
19711 to function or pointer to member function argument if the set of
19712 overloaded functions does not contain function templates and at most
19713 one of a set of overloaded functions provides a unique match.
19715 So if this is a template, just return success. */
19727 /* We don't copy orig_targs for this because if we have already deduced
19728 some template args from previous args, unify would complain when we
19729 try to deduce a template parameter for the same argument, even though
19730 there isn't really a conflict. */
19737 /* First make sure we didn't deduce anything that conflicts with
19738 explicitly specified args. */
19740 {
19747 /* Since we're unifying against ourselves, we will fill in
19748 template args used in the function parm list with our own
19749 template parms. Discard them. */
19752 {
19753 /* Check that the argument at each index of the deduced argument pack
19754 is equivalent to the corresponding explicitly specified argument.
19755 We may have deduced more arguments than were explicitly specified,
19756 and that's OK. */
19758 /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
19759 that's wrong if we deduce the same argument pack from multiple
19760 function arguments: it's only incomplete the first time. */
19773 }
19776 }
19779 {
19784 }
19787 }
19789 /* PARM is a template class (perhaps with unbound template
19790 parameters). ARG is a fully instantiated type. If ARG can be
19791 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
19792 TARGS are as for unify. */
19794 static tree
19797 {
19798 tree copy_of_targs;
19808 /* We need to make a new template argument vector for the call to
19809 unify. If we used TARGS, we'd clutter it up with the result of
19810 the attempted unification, even if this class didn't work out.
19811 We also don't want to commit ourselves to all the unifications
19812 we've already done, since unification is supposed to be done on
19813 an argument-by-argument basis. In other words, consider the
19814 following pathological case:
19816 template <int I, int J, int K>
19817 struct S {};
19819 template <int I, int J>
19820 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
19822 template <int I, int J, int K>
19823 void f(S<I, J, K>, S<I, I, I>);
19825 void g() {
19826 S<0, 0, 0> s0;
19827 S<0, 1, 2> s2;
19829 f(s0, s2);
19830 }
19832 Now, by the time we consider the unification involving `s2', we
19833 already know that we must have `f<0, 0, 0>'. But, even though
19834 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
19835 because there are two ways to unify base classes of S<0, 1, 2>
19836 with S<I, I, I>. If we kept the already deduced knowledge, we
19837 would reject the possibility I=1. */
19841 {
19845 }
19847 /* If unification failed, we're done. */
19853 }
19855 /* Given a template type PARM and a class type ARG, find the unique
19856 base type in ARG that is an instance of PARM. We do not examine
19857 ARG itself; only its base-classes. If there is not exactly one
19858 appropriate base class, return NULL_TREE. PARM may be the type of
19859 a partial specialization, as well as a plain template type. Used
19860 by unify. */
19862 static enum template_base_result
19865 {
19867 tree binfo;
19873 {
19874 /* The type could not be completed. */
19877 }
19879 /* Walk in inheritance graph order. The search order is not
19880 important, and this avoids multiple walks of virtual bases. */
19882 {
19887 {
19888 /* If there is more than one satisfactory baseclass, then:
19890 [temp.deduct.call]
19892 If they yield more than one possible deduced A, the type
19893 deduction fails.
19895 applies. */
19897 {
19900 }
19903 }
19904 }
19908 }
19910 /* Returns the level of DECL, which declares a template parameter. */
19912 static int
19914 {
19916 {
19926 }
19928 }
19930 /* Decide whether ARG can be unified with PARM, considering only the
19931 cv-qualifiers of each type, given STRICT as documented for unify.
19932 Returns nonzero iff the unification is OK on that basis. */
19934 static int
19936 {
19942 {
19943 /* Although a CVR qualifier is ignored when being applied to a
19944 substituted template parameter ([8.3.2]/1 for example), that
19945 does not allow us to unify "const T" with "int&" because both
19946 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19947 It is ok when we're allowing additional CV qualifiers
19948 at the outer level [14.8.2.1]/3,1st bullet. */
19958 }
19969 }
19971 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19972 void
19974 {
19978 {
19981 }
19982 else
19983 {
19986 }
19987 }
19989 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19990 do { \
19991 if (unify (TP, TA, P, A, S, EP)) \
19992 return 1; \
19993 } while (0)
19995 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19996 expansion at the end of PACKED_PARMS. Returns 0 if the type
19997 deduction succeeds, 1 otherwise. STRICT is the same as in
19998 fn_type_unification. CALL_ARGS_P is true iff PACKED_ARGS is actually a
19999 function call argument list. We'll need to adjust the arguments to make them
20000 types. SUBR tells us if this is from a recursive call to
20001 type_unification_real, or for comparing two template argument
20002 lists. */
20004 static int
20008 {
20009 tree parm
20019 /* Determine the parameter packs we will be deducing from the
20020 pattern, and record their current deductions. */
20023 {
20027 /* Determine the index and level of this parameter pack. */
20030 /* Keep track of the parameter packs and their corresponding
20031 argument packs. */
20034 }
20036 /* Loop through all of the arguments that have not yet been
20037 unified and unify each with the pattern. */
20039 {
20040 tree parm;
20044 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
20045 or the element of its argument pack at the current index if
20046 this argument was explicitly specified. */
20048 {
20057 {
20060 }
20062 }
20064 /* If we had explicit template arguments, substitute them into the
20065 pattern before deduction. */
20067 {
20068 /* Some arguments might still be unspecified or dependent. */
20076 NULL_TREE);
20081 }
20082 else
20085 /* Unify the pattern with the current argument. */
20087 explain_p))
20090 /* For each parameter pack, collect the deduced value. */
20092 {
20098 }
20099 }
20101 /* Verify that the results of unification with the parameter packs
20102 produce results consistent with what we've seen before, and make
20103 the deduced argument packs available. */
20105 {
20112 /* By default keep the original deduced argument pack.
20113 If necessary, more specific code is going to update the
20114 resulting deduced argument later down in this function. */
20118 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
20119 actually deduce anything. */
20127 {
20128 /* If we had fewer function args than explicit template args,
20129 just use the explicits. */
20134 }
20137 {
20138 tree result;
20139 /* Build the deduced *_ARGUMENT_PACK. */
20141 {
20144 }
20145 else
20150 /* Note the deduced argument packs for this parameter
20151 pack. */
20153 }
20157 {
20158 /* We only had the explicitly-provided arguments before, but
20159 now we have a complete set of arguments. */
20165 }
20166 else
20167 {
20173 /* Inconsistent unification of this parameter pack. */
20175 bad_old_arg,
20176 bad_new_arg);
20177 }
20178 }
20181 }
20183 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
20184 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
20185 parameters and return value are as for unify. */
20187 static int
20191 {
20192 tree parm_max;
20193 tree arg_max;
20197 /* Our representation of array types uses "N - 1" as the
20198 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
20199 not an integer constant. We cannot unify arbitrarily
20200 complex expressions, so we eliminate the MINUS_EXPRs
20201 here. */
20205 {
20208 }
20212 {
20213 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
20214 trying to unify the type of a variable with the type
20215 of a template parameter. For example:
20217 template <unsigned int N>
20218 void f (char (&) [N]);
20219 int g();
20220 void h(int i) {
20221 char a[g(i)];
20222 f(a);
20223 }
20225 Here, the type of the ARG will be "int [g(i)]", and
20226 may be a SAVE_EXPR, etc. */
20230 }
20232 /* If only one of the bounds used a MINUS_EXPR, compensate
20233 by adding one to the other bound. */
20236 integer_type_node,
20237 parm_max,
20238 integer_one_node);
20241 integer_type_node,
20242 arg_max,
20243 integer_one_node);
20247 }
20249 /* Returns whether T, a P or A in unify, is a type, template or expression. */
20253 static pa_kind_t
20255 {
20264 else
20266 }
20268 /* Deduce the value of template parameters. TPARMS is the (innermost)
20269 set of template parameters to a template. TARGS is the bindings
20270 for those template parameters, as determined thus far; TARGS may
20271 include template arguments for outer levels of template parameters
20272 as well. PARM is a parameter to a template function, or a
20273 subcomponent of that parameter; ARG is the corresponding argument.
20274 This function attempts to match PARM with ARG in a manner
20275 consistent with the existing assignments in TARGS. If more values
20276 are deduced, then TARGS is updated.
20278 Returns 0 if the type deduction succeeds, 1 otherwise. The
20279 parameter STRICT is a bitwise or of the following flags:
20281 UNIFY_ALLOW_NONE:
20282 Require an exact match between PARM and ARG.
20283 UNIFY_ALLOW_MORE_CV_QUAL:
20284 Allow the deduced ARG to be more cv-qualified (by qualification
20285 conversion) than ARG.
20286 UNIFY_ALLOW_LESS_CV_QUAL:
20287 Allow the deduced ARG to be less cv-qualified than ARG.
20288 UNIFY_ALLOW_DERIVED:
20289 Allow the deduced ARG to be a template base class of ARG,
20290 or a pointer to a template base class of the type pointed to by
20291 ARG.
20292 UNIFY_ALLOW_INTEGER:
20293 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
20294 case for more information.
20295 UNIFY_ALLOW_OUTER_LEVEL:
20296 This is the outermost level of a deduction. Used to determine validity
20297 of qualification conversions. A valid qualification conversion must
20298 have const qualified pointers leading up to the inner type which
20299 requires additional CV quals, except at the outer level, where const
20300 is not required [conv.qual]. It would be normal to set this flag in
20301 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
20302 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
20303 This is the outermost level of a deduction, and PARM can be more CV
20304 qualified at this point.
20305 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
20306 This is the outermost level of a deduction, and PARM can be less CV
20307 qualified at this point. */
20309 static int
20312 {
20314 tree targ;
20315 tree tparm;
20317 tsubst_flags_t complain = (explain_p
20318 ? tf_warning_or_error
20321 /* I don't think this will do the right thing with respect to types.
20322 But the only case I've seen it in so far has been array bounds, where
20323 signedness is the only information lost, and I think that will be
20324 okay. */
20332 /* We can't deduce anything from this, but we might get all the
20333 template args from other function args. */
20339 /* If PARM uses template parameters, then we can't bail out here,
20340 even if ARG == PARM, since we won't record unifications for the
20341 template parameters. We might need them if we're trying to
20342 figure out which of two things is more specialized. */
20346 /* Handle init lists early, so the rest of the function can assume
20347 we're dealing with a type. */
20349 {
20354 /* Replace T with std::initializer_list<T> for deduction. */
20361 /* We can only deduce from an initializer list argument if the
20362 parameter is std::initializer_list or an array; otherwise this
20363 is a non-deduced context. */
20368 else
20369 {
20371 /* Deduction is defined in terms of a single type, so just punt
20372 on the (bizarre) std::initializer_list<T...>. */
20375 }
20378 {
20385 {
20389 /* It should only be possible to get here for a call. */
20391 elt_strict |= maybe_adjust_types_for_deduction
20394 }
20397 explain_p);
20398 }
20402 {
20403 /* Also deduce from the length of the initializer list. */
20410 }
20412 /* If the std::initializer_list<T> deduction worked, replace the
20413 deduced A with std::initializer_list<A>. */
20415 {
20420 }
20422 }
20424 /* If parm and arg aren't the same kind of thing (template, type, or
20425 expression), fail early. */
20429 /* Immediately reject some pairs that won't unify because of
20430 cv-qualification mismatches. */
20433 /* It is the elements of the array which hold the cv quals of an array
20434 type, and the elements might be template type parms. We'll check
20435 when we recurse. */
20437 /* We check the cv-qualifiers when unifying with template type
20438 parameters below. We want to allow ARG `const T' to unify with
20439 PARM `T' for example, when computing which of two templates
20440 is more specialized, for example. */
20454 {
20458 /* In a type which contains a nested-name-specifier, template
20459 argument values cannot be deduced for template parameters used
20460 within the nested-name-specifier. */
20472 /* The PARM is not one we're trying to unify. Just check
20473 to see if it matches ARG. */
20474 {
20479 else
20481 }
20488 /* Check for mixed types and values. */
20496 {
20499 {
20500 /* First try to match ARG directly. */
20502 explain_p);
20504 {
20505 /* Otherwise, look for a suitable base of ARG, as below. */
20512 }
20513 }
20514 /* ARG must be constructed from a template class or a template
20515 template parameter. */
20520 /* Deduce arguments T, i from TT<T> or TT<i>. */
20526 /* Fall through to deduce template name. */
20527 }
20531 {
20532 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
20534 /* Simple cases: Value already set, does match or doesn't. */
20539 }
20540 else
20541 {
20542 /* If PARM is `const T' and ARG is only `int', we don't have
20543 a match unless we are allowing additional qualification.
20544 If ARG is `const int' and PARM is just `T' that's OK;
20545 that binds `const int' to `T'. */
20550 /* Consider the case where ARG is `const volatile int' and
20551 PARM is `const T'. Then, T should be `volatile int'. */
20552 arg = cp_build_qualified_type_real
20557 /* Simple cases: Value already set, does match or doesn't. */
20563 /* Make sure that ARG is not a variable-sized array. (Note
20564 that were talking about variable-sized arrays (like
20565 `int[n]'), rather than arrays of unknown size (like
20566 `int[]').) We'll get very confused by such a type since
20567 the bound of the array is not constant, and therefore
20568 not mangleable. Besides, such types are not allowed in
20569 ISO C++, so we can do as we please here. We do allow
20570 them for 'auto' deduction, since that isn't ABI-exposed. */
20574 /* Strip typedefs as in convert_template_argument. */
20576 }
20578 /* If ARG is a parameter pack or an expansion, we cannot unify
20579 against it unless PARM is also a parameter pack. */
20584 /* If the argument deduction results is a METHOD_TYPE,
20585 then there is a problem.
20586 METHOD_TYPE doesn't map to any real C++ type the result of
20587 the deduction can not be of that type. */
20601 {
20602 /* The PARM is not one we're trying to unify. Just check
20603 to see if it matches ARG. */
20609 }
20615 {
20620 }
20623 /* We deduce from array bounds in try_array_deduction. */
20627 {
20632 }
20634 /* [temp.deduct.type] If, in the declaration of a function template
20635 with a non-type template-parameter, the non-type
20636 template-parameter is used in an expression in the function
20637 parameter-list and, if the corresponding template-argument is
20638 deduced, the template-argument type shall match the type of the
20639 template-parameter exactly, except that a template-argument
20640 deduced from an array bound may be of any integral type.
20641 The non-type parameter might use already deduced type parameters. */
20644 {
20648 }
20651 /* Template-parameter dependent expression. Just accept it for now.
20652 It will later be processed in convert_template_argument. */
20653 ;
20658 /* Convert the ARG to the type of PARM; the deduced non-type
20659 template argument must exactly match the types of the
20660 corresponding parameter. */
20663 /* We haven't deduced the type of this parameter yet. Try again
20664 later. */
20666 else
20669 /* If ARG is a parameter pack or an expansion, we cannot unify
20670 against it unless PARM is also a parameter pack. */
20675 {
20678 }
20683 {
20684 /* A pointer-to-member constant can be unified only with
20685 another constant. */
20689 /* Just unify the class member. It would be useless (and possibly
20690 wrong, depending on the strict flags) to unify also
20691 PTRMEM_CST_CLASS, because we want to be sure that both parm and
20692 arg refer to the same variable, even if through different
20693 classes. For instance:
20695 struct A { int x; };
20696 struct B : A { };
20698 Unification of &A::x and &B::x must succeed. */
20701 }
20704 {
20708 /* [temp.deduct.call]
20710 A can be another pointer or pointer to member type that can
20711 be converted to the deduced A via a qualification
20712 conversion (_conv.qual_).
20714 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
20715 This will allow for additional cv-qualification of the
20716 pointed-to types if appropriate. */
20719 /* The derived-to-base conversion only persists through one
20720 level of pointers. */
20725 }
20757 /* We have already checked cv-qualification at the top of the
20758 function. */
20762 /* As far as unification is concerned, this wins. Later checks
20763 will invalidate it if necessary. */
20766 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
20767 /* Type INTEGER_CST can come from ordinary constant template args. */
20779 {
20789 /* Check for pack expansions in the parameters. */
20791 {
20793 {
20795 /* We can unify against something with a trailing
20796 parameter pack. */
20798 else
20799 /* [temp.deduct.type]/9: If the template argument list of
20800 P contains a pack expansion that is not the last
20801 template argument, the entire template argument list
20802 is a non-deduced context. */
20804 }
20805 }
20807 /* If we don't have enough arguments to satisfy the parameters
20808 (not counting the pack expression at the end), or we have
20809 too many arguments for a parameter list that doesn't end in
20810 a pack expression, we can't unify. */
20816 /* Unify all of the parameters that precede the (optional)
20817 pack expression. */
20819 {
20824 }
20827 DEDUCE_EXACT,
20830 }
20838 {
20846 }
20851 {
20855 {
20856 /* First, we try to unify the PARM and ARG directly. */
20861 {
20862 /* Fallback to the special case allowed in
20863 [temp.deduct.call]:
20865 If P is a class, and P has the form
20866 template-id, then A can be a derived class of
20867 the deduced A. Likewise, if P is a pointer to
20868 a class of the form template-id, A can be a
20869 pointer to a derived class pointed to by the
20870 deduced A. */
20876 {
20877 /* Don't give the derived diagnostic if we're
20878 already dealing with the same template. */
20879 bool same_template
20885 }
20886 }
20887 }
20891 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20892 Then, we should unify `int' and `U'. */
20894 else
20895 /* There's no chance of unification succeeding. */
20900 }
20907 {
20910 tree a;
20916 /* CV qualifications for methods can never be deduced, they must
20917 match exactly. We need to check them explicitly here,
20918 because type_unification_real treats them as any other
20919 cv-qualified parameter. */
20921 && (!check_cv_quals_for_unify
20949 {
20961 }
20964 }
20967 /* Unify a pointer to member with a pointer to member function, which
20968 deduces the type of the member as a function type. */
20970 {
20971 /* Check top-level cv qualifiers */
20979 /* Determine the type of the function we are unifying against. */
20983 }
21002 /* Matched cases are handled by the ARG == PARM test above. */
21006 /* We might get a variable as a non-type template argument in parm if the
21007 corresponding parameter is type-dependent. Make any necessary
21008 adjustments based on whether arg is a reference. */
21012 {
21017 }
21018 /* Now use the normal expression code to check whether they match. */
21029 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
21030 or UNDERLYING_TYPE nodes. */
21034 /* Unification fails if we hit an error node. */
21039 {
21049 }
21050 /* FALLTHRU */
21053 /* An unresolved overload is a nondeduced context. */
21057 expr:
21058 /* We must be looking at an expression. This can happen with
21059 something like:
21061 template <int I>
21062 void foo(S<I>, S<I + 2>);
21064 This is a "nondeduced context":
21066 [deduct.type]
21068 The nondeduced contexts are:
21070 --A type that is a template-id in which one or more of
21071 the template-arguments is an expression that references
21072 a template-parameter.
21074 In these cases, we assume deduction succeeded, but don't
21075 actually infer any unifications. */
21080 else
21082 }
21083 }
21084 #undef RECUR_AND_CHECK_FAILURE
21085 \f
21086 /* Note that DECL can be defined in this translation unit, if
21087 required. */
21089 static void
21091 {
21092 tree clone;
21096 }
21098 /* Called if RESULT is explicitly instantiated, or is a member of an
21099 explicitly instantiated class. */
21101 void
21103 {
21106 /* If this entity has already been written out, it's too late to
21107 make any modifications. */
21111 /* For anonymous namespace we don't need to do anything. */
21113 {
21116 }
21119 /* The TREE_PUBLIC flag for function declarations will have been
21120 set correctly by tsubst. */
21123 /* This might have been set by an earlier implicit instantiation. */
21128 else
21129 {
21132 /* Always make artificials weak. */
21135 /* For WIN32 we also want to put explicit instantiations in
21136 linkonce sections. */
21139 }
21141 /* If EXTERN_P, then this function will not be emitted -- unless
21142 followed by an explicit instantiation, at which point its linkage
21143 will be adjusted. If !EXTERN_P, then this function will be
21144 emitted here. In neither circumstance do we want
21145 import_export_decl to adjust the linkage. */
21147 }
21149 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
21150 important template arguments. If any are missing, we check whether
21151 they're important by using error_mark_node for substituting into any
21152 args that were used for partial ordering (the ones between ARGS and END)
21153 and seeing if it bubbles up. */
21155 static bool
21157 {
21162 {
21165 }
21167 {
21171 }
21173 }
21175 /* Given two function templates PAT1 and PAT2, return:
21177 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
21178 -1 if PAT2 is more specialized than PAT1.
21179 0 if neither is more specialized.
21181 LEN indicates the number of parameters we should consider
21182 (defaulted parameters should not be considered).
21184 The 1998 std underspecified function template partial ordering, and
21185 DR214 addresses the issue. We take pairs of arguments, one from
21186 each of the templates, and deduce them against each other. One of
21187 the templates will be more specialized if all the *other*
21188 template's arguments deduce against its arguments and at least one
21189 of its arguments *does* *not* deduce against the other template's
21190 corresponding argument. Deduction is done as for class templates.
21191 The arguments used in deduction have reference and top level cv
21192 qualifiers removed. Iff both arguments were originally reference
21193 types *and* deduction succeeds in both directions, an lvalue reference
21194 wins against an rvalue reference and otherwise the template
21195 with the more cv-qualified argument wins for that pairing (if
21196 neither is more cv-qualified, they both are equal). Unlike regular
21197 deduction, after all the arguments have been deduced in this way,
21198 we do *not* verify the deduced template argument values can be
21199 substituted into non-deduced contexts.
21201 The logic can be a bit confusing here, because we look at deduce1 and
21202 targs1 to see if pat2 is at least as specialized, and vice versa; if we
21203 can find template arguments for pat1 to make arg1 look like arg2, that
21204 means that arg2 is at least as specialized as arg1. */
21206 int
21208 {
21221 /* Remove the this parameter from non-static member functions. If
21222 one is a non-static member function and the other is not a static
21223 member function, remove the first parameter from that function
21224 also. This situation occurs for operator functions where we
21225 locate both a member function (with this pointer) and non-member
21226 operator (with explicit first operand). */
21228 {
21233 }
21235 {
21238 {
21239 len--;
21241 }
21242 }
21244 /* If only one is a conversion operator, they are unordered. */
21248 /* Consider the return type for a conversion function */
21250 {
21253 len++;
21254 }
21256 processing_template_decl++;
21262 /* Stop when an ellipsis is seen. */
21264 {
21275 {
21276 /* When both arguments are pack expansions, we need only
21277 unify the patterns themselves. */
21281 /* This is the last comparison we need to do. */
21283 }
21285 /* DR 1847: If a particular P contains no template-parameters that
21286 participate in template argument deduction, that P is not used to
21287 determine the ordering. */
21293 {
21297 }
21300 {
21304 }
21310 {
21316 /* Setup the parameter vector, which contains only ARG1. */
21319 /* Setup the argument vector, which contains the remaining
21320 arguments. */
21329 /* We cannot deduce in the other direction, because ARG1 is
21330 a pack expansion but ARG2 is not. */
21332 }
21334 {
21340 /* Setup the parameter vector, which contains only ARG1. */
21343 /* Setup the argument vector, which contains the remaining
21344 arguments. */
21353 /* We cannot deduce in the other direction, because ARG2 is
21354 a pack expansion but ARG1 is not.*/
21356 }
21358 else
21359 {
21360 /* The normal case, where neither argument is a pack
21361 expansion. */
21368 }
21370 /* If we couldn't deduce arguments for tparms1 to make arg1 match
21371 arg2, then arg2 is not as specialized as arg1. */
21377 /* "If, for a given type, deduction succeeds in both directions
21378 (i.e., the types are identical after the transformations above)
21379 and both P and A were reference types (before being replaced with
21380 the type referred to above):
21381 - if the type from the argument template was an lvalue reference and
21382 the type from the parameter template was not, the argument type is
21383 considered to be more specialized than the other; otherwise,
21384 - if the type from the argument template is more cv-qualified
21385 than the type from the parameter template (as described above),
21386 the argument type is considered to be more specialized than the other;
21387 otherwise,
21388 - neither type is more specialized than the other." */
21391 {
21393 {
21396 else
21398 }
21400 {
21405 }
21406 }
21409 /* We've failed to deduce something in either direction.
21410 These must be unordered. */
21413 next:
21417 /* We have already processed all of the arguments in our
21418 handing of the pack expansion type. */
21423 }
21425 /* "In most cases, all template parameters must have values in order for
21426 deduction to succeed, but for partial ordering purposes a template
21427 parameter may remain without a value provided it is not used in the
21428 types being used for partial ordering."
21430 Thus, if we are missing any of the targs1 we need to substitute into
21431 origs1, then pat2 is not as specialized as pat1. This can happen when
21432 there is a nondeduced context. */
21438 processing_template_decl--;
21440 /* If both deductions succeed, the partial ordering selects the more
21441 constrained template. */
21443 {
21448 }
21450 /* All things being equal, if the next argument is a pack expansion
21451 for one function but not for the other, prefer the
21452 non-variadic function. FIXME this is bogus; see c++/41958. */
21456 {
21459 }
21465 else
21467 }
21469 /* Determine which of two partial specializations of TMPL is more
21470 specialized.
21472 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
21473 to the first partial specialization. The TREE_PURPOSE is the
21474 innermost set of template parameters for the partial
21475 specialization. PAT2 is similar, but for the second template.
21477 Return 1 if the first partial specialization is more specialized;
21478 -1 if the second is more specialized; 0 if neither is more
21479 specialized.
21481 See [temp.class.order] for information about determining which of
21482 two templates is more specialized. */
21484 static int
21486 {
21487 tree targs;
21496 /* Just like what happens for functions, if we are ordering between
21497 different template specializations, we may encounter dependent
21498 types in the arguments, and we need our dependency check functions
21499 to behave correctly. */
21503 {
21506 }
21510 {
21513 }
21516 /* If both deductions succeed, the partial ordering selects the more
21517 constrained template. */
21521 /* In the case of a tie where at least one of the templates
21522 has a parameter pack at the end, the template with the most
21523 non-packed parameters wins. */
21525 && any_deductions
21528 {
21534 /* We don't count the pack expansion at the end. */
21544 }
21547 }
21549 /* Return the template arguments that will produce the function signature
21550 DECL from the function template FN, with the explicit template
21551 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
21552 also match. Return NULL_TREE if no satisfactory arguments could be
21553 found. */
21555 static tree
21557 {
21561 tree decl_arg_types;
21564 tree arg;
21568 /* Never do unification on the 'this' parameter. */
21589 }
21591 /* Return the innermost template arguments that, when applied to a partial
21592 specialization SPEC_TMPL of TMPL, yield the ARGS.
21594 For example, suppose we have:
21596 template <class T, class U> struct S {};
21597 template <class T> struct S<T*, int> {};
21599 Then, suppose we want to get `S<double*, int>'. SPEC_TMPL will be the
21600 partial specialization and the ARGS will be {double*, int}. The resulting
21601 vector will be {double}, indicating that `T' is bound to `double'. */
21603 static tree
21605 {
21607 tree spec_args
21610 tree deduced_args;
21611 tree innermost_deduced_args;
21615 {
21619 innermost_deduced_args);
21620 }
21621 else
21625 again:
21634 {
21636 {
21642 }
21644 }
21648 {
21651 }
21653 /* Verify that nondeduced template arguments agree with the type
21654 obtained from argument deduction.
21656 For example:
21658 struct A { typedef int X; };
21659 template <class T, class U> struct C {};
21660 template <class T> struct C<T, typename T::X> {};
21662 Then with the instantiation `C<A, int>', we can deduce that
21663 `T' is `A' but unify () does not check whether `typename T::X'
21664 is `int'. */
21673 /* We only need to check the innermost arguments; the other
21674 arguments will always agree. */
21679 /* Now that we have bindings for all of the template arguments,
21680 ensure that the arguments deduced for the template template
21681 parameters have compatible template parameter lists. See the use
21682 of template_template_parm_bindings_ok_p in fn_type_unification
21683 for more information. */
21688 }
21690 // Compare two function templates T1 and T2 by deducing bindings
21691 // from one against the other. If both deductions succeed, compare
21692 // constraints to see which is more constrained.
21693 static int
21695 {
21700 {
21703 }
21706 {
21709 }
21711 // If both deductions succeed, then one may be more constrained.
21716 }
21718 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
21719 Return the TREE_LIST node with the most specialized template, if
21720 any. If there is no most specialized template, the error_mark_node
21721 is returned.
21723 Note that this function does not look at, or modify, the
21724 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
21725 returned is one of the elements of INSTANTIATIONS, callers may
21726 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
21727 and retrieve it from the value returned. */
21729 tree
21731 {
21738 {
21744 {
21745 /* Equally specialized, move to next function. If there
21746 is no next function, nothing's most specialized. */
21751 }
21752 }
21755 /* Now verify that champ is better than everything earlier in the
21756 instantiation list. */
21759 {
21762 }
21763 }
21765 processing_template_decl--;
21771 }
21773 /* If DECL is a specialization of some template, return the most
21774 general such template. Otherwise, returns NULL_TREE.
21776 For example, given:
21778 template <class T> struct S { template <class U> void f(U); };
21780 if TMPL is `template <class U> void S<int>::f(U)' this will return
21781 the full template. This function will not trace past partial
21782 specializations, however. For example, given in addition:
21784 template <class T> struct S<T*> { template <class U> void f(U); };
21786 if TMPL is `template <class U> void S<int*>::f(U)' this will return
21787 `template <class T> template <class U> S<T*>::f(U)'. */
21789 tree
21791 {
21793 {
21796 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
21797 template friend, or a FIELD_DECL for a capture pack. */
21800 }
21802 /* Look for more and more general templates. */
21804 {
21805 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
21806 (See cp-tree.h for details.) */
21815 /* Stop if we run into an explicitly specialized class template. */
21822 }
21825 }
21827 /* Return the most specialized of the template partial specializations
21828 which can produce TARGET, a specialization of some class or variable
21829 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
21830 a TEMPLATE_DECL node corresponding to the partial specialization, while
21831 the TREE_PURPOSE is the set of template arguments that must be
21832 substituted into the template pattern in order to generate TARGET.
21834 If the choice of partial specialization is ambiguous, a diagnostic
21835 is issued, and the error_mark_node is returned. If there are no
21836 partial specializations matching TARGET, then NULL_TREE is
21837 returned, indicating that the primary template should be used. */
21839 static tree
21841 {
21843 tree t;
21844 tree champ;
21851 {
21855 }
21857 {
21860 }
21862 {
21866 }
21867 else
21872 /* For determining which partial specialization to use, only the
21873 innermost args are interesting. */
21875 {
21878 }
21881 {
21882 tree spec_args;
21886 {
21887 /* Substitute in the template args from the enclosing class. */
21891 }
21898 {
21902 /* Keep the candidate only if the constraints are satisfied,
21903 or if we're not compiling with concepts. */
21906 {
21909 }
21910 }
21911 }
21921 {
21924 ;
21925 else
21926 {
21928 {
21931 {
21934 }
21935 }
21937 }
21938 }
21942 {
21945 {
21948 }
21949 }
21952 {
21959 else
21963 {
21968 }
21971 }
21974 }
21976 /* Explicitly instantiate DECL. */
21978 void
21980 {
21985 /* An error occurred, for which grokdeclarator has already issued
21986 an appropriate message. */
21989 {
21992 }
21998 {
21999 /* There is an asymmetry here in the way VAR_DECLs and
22000 FUNCTION_DECLs are handled by grokdeclarator. In the case of
22001 the latter, the DECL we get back will be marked as a
22002 template instantiation, and the appropriate
22003 DECL_TEMPLATE_INFO will be set up. This does not happen for
22004 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
22005 should handle VAR_DECLs as it currently handles
22006 FUNCTION_DECLs. */
22008 {
22011 }
22014 {
22017 }
22019 {
22024 }
22025 }
22027 {
22030 }
22031 else
22034 /* Check for various error cases. Note that if the explicit
22035 instantiation is valid the RESULT will currently be marked as an
22036 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
22037 until we get here. */
22040 {
22041 /* DR 259 [temp.spec].
22043 Both an explicit instantiation and a declaration of an explicit
22044 specialization shall not appear in a program unless the explicit
22045 instantiation follows a declaration of the explicit specialization.
22047 For a given set of template parameters, if an explicit
22048 instantiation of a template appears after a declaration of an
22049 explicit specialization for that template, the explicit
22050 instantiation has no effect. */
22052 }
22054 {
22055 /* [temp.spec]
22057 No program shall explicitly instantiate any template more
22058 than once.
22060 We check DECL_NOT_REALLY_EXTERN so as not to complain when
22061 the first instantiation was `extern' and the second is not,
22062 and EXTERN_P for the opposite case. */
22065 /* If an "extern" explicit instantiation follows an ordinary
22066 explicit instantiation, the template is instantiated. */
22069 }
22071 {
22074 }
22076 {
22079 }
22082 ;
22084 {
22087 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
22090 }
22091 else
22099 }
22101 static void
22103 {
22109 {
22112 }
22113 }
22115 /* Called from do_type_instantiation through binding_table_foreach to
22116 do recursive instantiation for the type bound in ENTRY. */
22117 static void
22119 {
22125 }
22127 /* Called from do_type_instantiation to instantiate a member
22128 (a member function or a static member variable) of an
22129 explicitly instantiated class template. */
22130 static void
22132 {
22137 }
22139 /* Perform an explicit instantiation of template class T. STORAGE, if
22140 non-null, is the RID for extern, inline or static. COMPLAIN is
22141 nonzero if this is called from the parser, zero if called recursively,
22142 since the standard is unclear (as detailed below). */
22144 void
22146 {
22156 {
22157 tree tmpl =
22161 else
22164 }
22169 {
22172 t);
22174 }
22177 {
22179 {
22181 {
22184 "ISO C++ 1998 forbids the use of %<extern%> on "
22186 }
22187 else
22189 "ISO C++ forbids the use of %qE"
22191 }
22199 else
22200 {
22202 storage);
22204 }
22205 }
22208 {
22209 /* DR 259 [temp.spec].
22211 Both an explicit instantiation and a declaration of an explicit
22212 specialization shall not appear in a program unless the explicit
22213 instantiation follows a declaration of the explicit specialization.
22215 For a given set of template parameters, if an explicit
22216 instantiation of a template appears after a declaration of an
22217 explicit specialization for that template, the explicit
22218 instantiation has no effect. */
22220 }
22222 {
22223 /* [temp.spec]
22225 No program shall explicitly instantiate any template more
22226 than once.
22228 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
22229 instantiation was `extern'. If EXTERN_P then the second is.
22230 These cases are OK. */
22237 /* If we've already instantiated the template, just return now. */
22240 }
22248 {
22249 tree tmp;
22251 /* In contrast to implicit instantiation, where only the
22252 declarations, and not the definitions, of members are
22253 instantiated, we have here:
22255 [temp.explicit]
22257 The explicit instantiation of a class template specialization
22258 implies the instantiation of all of its members not
22259 previously explicitly specialized in the translation unit
22260 containing the explicit instantiation.
22262 Of course, we can't instantiate member template classes, since
22263 we don't have any arguments for them. Note that the standard
22264 is unclear on whether the instantiation of the members are
22265 *explicit* instantiations or not. However, the most natural
22266 interpretation is that it should be an explicit instantiation. */
22282 }
22283 }
22285 /* Given a function DECL, which is a specialization of TMPL, modify
22286 DECL to be a re-instantiation of TMPL with the same template
22287 arguments. TMPL should be the template into which tsubst'ing
22288 should occur for DECL, not the most general template.
22290 One reason for doing this is a scenario like this:
22292 template <class T>
22293 void f(const T&, int i);
22295 void g() { f(3, 7); }
22297 template <class T>
22298 void f(const T& t, const int i) { }
22300 Note that when the template is first instantiated, with
22301 instantiate_template, the resulting DECL will have no name for the
22302 first parameter, and the wrong type for the second. So, when we go
22303 to instantiate the DECL, we regenerate it. */
22305 static void
22307 {
22308 /* The arguments used to instantiate DECL, from the most general
22309 template. */
22310 tree code_pattern;
22314 /* Make sure that we can see identifiers, and compute access
22315 correctly. */
22319 {
22320 tree decl_parm;
22321 tree pattern_parm;
22322 tree specs;
22336 specs);
22338 /* Merge parameter declarations. */
22341 pattern_parm
22345 {
22346 tree parm_type;
22347 tree attributes;
22352 NULL_TREE);
22358 {
22361 }
22364 }
22365 /* Merge any parameters that match with the function parameter
22366 pack. */
22368 {
22370 tree expanded_types;
22371 /* Expand the TYPE_PACK_EXPANSION that provides the types for
22372 the parameters in this function parameter pack. */
22377 {
22378 tree parm_type;
22379 tree attributes;
22382 /* Rename the parameter to include the index. */
22391 {
22394 }
22396 }
22397 }
22398 /* Merge additional specifiers from the CODE_PATTERN. */
22402 }
22404 {
22412 }
22413 else
22417 }
22419 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
22420 substituted to get DECL. */
22422 tree
22424 {
22427 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
22428 for the instantiation. This is not always the most general
22429 template. Consider, for example:
22431 template <class T>
22432 struct S { template <class U> void f();
22433 template <> void f<int>(); };
22435 and an instantiation of S<double>::f<int>. We want TD to be the
22436 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
22438 more general template. */
22440 /* We must also deal with friend templates. Given:
22442 template <class T> struct S {
22443 template <class U> friend void f() {};
22444 };
22446 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
22447 so far as the language is concerned, but that's still
22448 where we get the pattern for the instantiation from. On
22449 other hand, if the definition comes outside the class, say:
22451 template <class T> struct S {
22452 template <class U> friend void f();
22453 };
22454 template <class U> friend void f() {}
22456 we don't need to look any further. That's what the check for
22457 DECL_INITIAL is for. */
22461 {
22462 /* The present template, TD, should not be a definition. If it
22463 were a definition, we should be using it! Note that we
22464 cannot restructure the loop to just keep going until we find
22465 a template with a definition, since that might go too far if
22466 a specialization was declared, but not defined. */
22468 /* Fetch the more general template. */
22470 }
22473 }
22475 /* Returns true if we need to instantiate this template instance even if we
22476 know we aren't going to emit it. */
22478 bool
22480 {
22481 /* We always instantiate inline functions so that we can inline them. An
22482 explicit instantiation declaration prohibits implicit instantiation of
22483 non-inline functions. With high levels of optimization, we would
22484 normally inline non-inline functions -- but we're not allowed to do
22485 that for "extern template" functions. Therefore, we check
22486 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
22490 /* And we need to instantiate static data members so that
22491 their initializers are available in integral constant
22492 expressions. */
22495 }
22497 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
22498 instantiate it now, modifying TREE_TYPE (fn). */
22500 void
22502 {
22505 /* Don't instantiate a noexcept-specification from template context. */
22520 {
22524 {
22539 }
22540 else
22544 }
22547 {
22550 else
22552 }
22553 }
22555 /* Produce the definition of D, a _DECL generated from a template. If
22556 DEFER_OK is true, then we don't have to actually do the
22557 instantiation now; we just have to do it sometime. Normally it is
22558 an error if this is an explicit instantiation but D is undefined.
22559 EXPL_INST_CLASS_MEM_P is true iff D is a member of an explicitly
22560 instantiated class template. */
22562 tree
22564 {
22566 tree gen_args;
22567 tree args;
22568 tree td;
22569 tree code_pattern;
22570 tree spec;
22571 tree gen_tmpl;
22579 /* This function should only be used to instantiate templates for
22580 functions and static member variables. */
22583 /* A concept is never instantiated. */
22586 /* Variables are never deferred; if instantiation is required, they
22587 are instantiated right away. That allows for better code in the
22588 case that an expression refers to the value of the variable --
22589 if the variable has a constant value the referring expression can
22590 take advantage of that fact. */
22594 /* Don't instantiate cloned functions. Instead, instantiate the
22595 functions they cloned. */
22603 /* D has already been instantiated or explicitly specialized, so
22604 there's nothing for us to do here.
22606 It might seem reasonable to check whether or not D is an explicit
22607 instantiation, and, if so, stop here. But when an explicit
22608 instantiation is deferred until the end of the compilation,
22609 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
22610 the instantiation. */
22613 /* Check to see whether we know that this template will be
22614 instantiated in some other file, as with "extern template"
22615 extension. */
22618 /* In general, we do not instantiate such templates. */
22626 /* We should already have the extra args. */
22629 /* And what's in the hash table should match D. */
22633 /* This needs to happen before any tsubsting. */
22639 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
22640 for the instantiation. */
22645 {
22646 /* Look up an explicit specialization, if any. */
22650 {
22653 }
22654 }
22658 /* We should never be trying to instantiate a member of a class
22659 template or partial specialization. */
22664 /* In the case of a friend template whose definition is provided
22665 outside the class, we may have too many arguments. Drop the
22666 ones we don't need. The same is true for specializations. */
22667 args = get_innermost_template_args
22671 {
22677 }
22678 else
22679 {
22684 else
22686 }
22688 /* We may be in the middle of deferred access check. Disable it now. */
22691 /* Unless an explicit instantiation directive has already determined
22692 the linkage of D, remember that a definition is available for
22693 this entity. */
22703 /* If D is a member of an explicitly instantiated class template,
22704 and no definition is available, treat it like an implicit
22705 instantiation. */
22708 {
22709 /* Leave linkage flags alone on instantiations with anonymous
22710 visibility. */
22712 {
22715 }
22717 }
22719 /* Defer all other templates, unless we have been explicitly
22720 forbidden from doing so. */
22722 template. */
22723 ! pattern_defined
22724 /* If it's OK to postpone instantiation, do so. */
22725 || defer_ok
22726 /* If this is a static data member that will be defined
22727 elsewhere, we don't want to instantiate the entire data
22728 member, but we do want to instantiate the initializer so that
22729 we can substitute that elsewhere. */
22731 /* Handle here a deleted function too, avoid generating
22732 its body (c++/61080). */
22734 {
22735 /* The definition of the static data member is now required so
22736 we must substitute the initializer. */
22740 {
22741 tree ns;
22742 tree init;
22751 args,
22754 /* If instantiating the initializer involved instantiating this
22755 again, don't call cp_finish_decl twice. */
22757 {
22758 /* Make sure the initializer is still constant, in case of
22759 circular dependency (template/instantiate6.C). */
22760 const_init
22764 LOOKUP_ONLYCONVERTING);
22765 }
22769 }
22771 /* We restore the source position here because it's used by
22772 add_pending_template. */
22778 /* [temp.explicit]
22780 The definition of a non-exported function template, a
22781 non-exported member function template, or a non-exported
22782 member function or static data member of a class template
22783 shall be present in every translation unit in which it is
22784 explicitly instantiated. */
22788 /* If we're in unevaluated context, we just wanted to get the
22789 constant value; this isn't an odr use, so don't queue
22790 a full instantiation. */
22793 /* ??? Historically, we have instantiated inline functions, even
22794 when marked as "extern template". */
22798 }
22799 /* Tell the repository that D is available in this translation unit
22800 -- and see if it is supposed to be instantiated here. */
22802 {
22803 /* In a PCH file, despite the fact that the repository hasn't
22804 requested instantiation in the PCH it is still possible that
22805 an instantiation will be required in a file that includes the
22806 PCH. */
22809 /* Instantiate inline functions so that the inliner can do its
22810 job, even though we'll not be emitting a copy of this
22811 function. */
22814 }
22817 tree fn_context;
22828 else
22829 {
22833 }
22835 /* Mark D as instantiated so that recursive calls to
22836 instantiate_decl do not try to instantiate it again. */
22839 /* Regenerate the declaration in case the template has been modified
22840 by a subsequent redeclaration. */
22843 /* We already set the file and line above. Reset them now in case
22844 they changed as a result of calling regenerate_decl_from_template. */
22848 {
22849 tree init;
22852 /* Clear out DECL_RTL; whatever was there before may not be right
22853 since we've reset the type of the declaration. */
22857 /* The initializer is placed in DECL_INITIAL by
22858 regenerate_decl_from_template so we don't need to
22859 push/pop_access_scope again here. Pull it out so that
22860 cp_finish_decl can process it. */
22865 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
22866 initializer. That function will defer actual emission until
22867 we have a chance to determine linkage. */
22870 /* Enter the scope of D so that access-checking works correctly. */
22883 }
22887 {
22889 tree tmpl_parm;
22890 tree spec_parm;
22894 /* Save away the current list, in case we are instantiating one
22895 template from within the body of another. */
22898 /* Set up the list of local specializations. */
22901 /* Set up context. */
22905 else
22906 {
22908 {
22909 /* When instantiating a lambda's templated function
22910 operator, we need to push the non-lambda class scope
22911 of the lambda itself so that the nested function
22912 stack is sufficiently correct to deal with this
22913 capture. */
22915 do
22920 }
22922 }
22924 /* Some typedefs referenced from within the template code need to be
22925 access checked at template instantiation time, i.e now. These
22926 types were added to the template at parsing time. Let's get those
22927 and perform the access checks then. */
22929 args);
22931 /* Create substitution entries for the parameters. */
22935 {
22939 }
22941 {
22943 {
22946 }
22947 else
22948 {
22949 /* Register the (value) argument pack as a specialization of
22950 TMPL_PARM, then move on. */
22953 }
22954 }
22957 /* Substitute into the body of the function. */
22961 else
22962 {
22967 /* Set the current input_location to the end of the function
22968 so that finish_function knows where we are. */
22969 input_location
22972 /* Remember if we saw an infinite loop in the template. */
22973 current_function_infinite_loop
22975 }
22977 /* We don't need the local specializations any more. */
22981 /* Finish the function. */
22985 else
22986 {
22989 }
22995 }
22997 /* We're not deferring instantiation any more. */
23002 else
23008 out:
23017 }
23019 /* Run through the list of templates that we wish we could
23020 instantiate, and instantiate any we can. RETRIES is the
23021 number of times we retry pending template instantiation. */
23023 void
23025 {
23029 /* Instantiating templates may trigger vtable generation. This in turn
23030 may require further template instantiations. We place a limit here
23031 to avoid infinite loop. */
23033 {
23037 "template instantiation depth exceeds maximum of %d"
23038 " instantiating %q+D, possibly from virtual table generation"
23042 /* Pretend that we defined it. */
23045 }
23047 do
23048 {
23053 {
23058 {
23059 tree fn;
23062 {
23066 fn;
23074 }
23077 }
23078 else
23079 {
23082 {
23083 instantiation
23089 }
23093 }
23096 /* If INSTANTIATION has been instantiated, then we don't
23097 need to consider it again in the future. */
23099 else
23100 {
23103 }
23106 }
23108 }
23112 }
23114 /* Substitute ARGVEC into T, which is a list of initializers for
23115 either base class or a non-static data member. The TREE_PURPOSEs
23116 are DECLs, and the TREE_VALUEs are the initializer values. Used by
23117 instantiate_decl. */
23119 static tree
23121 {
23125 {
23126 tree decl;
23127 tree init;
23133 {
23134 tree expr;
23135 tree arg;
23137 /* Expand the base class expansion type into separate base
23138 classes. */
23140 tf_warning_or_error,
23141 NULL_TREE);
23145 /* We'll be building separate TREE_LISTs of arguments for
23146 each base. */
23152 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
23153 expand each argument in the TREE_VALUE of t. */
23160 /* VOID_TYPE_NODE is used to indicate
23161 value-initialization. */
23162 {
23165 }
23166 else
23167 {
23168 /* Substitute parameter packs into each argument in the
23169 TREE_LIST. */
23172 {
23173 tree expanded_exprs;
23175 /* Expand the argument. */
23177 expanded_exprs
23179 tf_warning_or_error,
23180 NULL_TREE);
23184 /* Prepend each of the expanded expressions to the
23185 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
23187 {
23192 }
23193 }
23196 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
23197 since we built them backwards. */
23199 {
23202 }
23203 }
23204 }
23207 {
23209 {
23213 }
23214 else
23215 {
23216 tree tmp;
23231 /* If we had an initializer but it instantiated to nothing,
23232 value-initialize the object. This will only occur when
23233 the initializer was a pack expansion where the parameter
23234 packs used in that expansion were of length zero. */
23237 }
23240 {
23244 }
23245 }
23246 }
23248 }
23250 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
23252 static void
23254 {
23259 else
23261 }
23263 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
23264 is the instantiation (which should have been created with
23265 start_enum) and ARGS are the template arguments to use. */
23267 static void
23269 {
23270 tree e;
23276 {
23277 tree value;
23278 tree decl;
23281 /* Note that in a template enum, the TREE_VALUE is the
23282 CONST_DECL, not the corresponding INTEGER_CST. */
23287 /* Give this enumeration constant the correct access. */
23290 /* Actually build the enumerator itself. Here we're assuming that
23291 enumerators can't have dependent attributes. */
23294 }
23304 }
23306 /* DECL is a FUNCTION_DECL that is a template specialization. Return
23307 its type -- but without substituting the innermost set of template
23308 arguments. So, innermost set of template parameters will appear in
23309 the type. */
23311 tree
23313 {
23314 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
23316 }
23318 /* Return truthvalue if we're processing a template different from
23319 the last one involved in diagnostics. */
23320 bool
23322 {
23324 }
23326 /* Remember current template involved in diagnostics. */
23327 void
23329 {
23331 }
23335 {
23337 }
23339 /* Return TRUE if current_function_decl is being instantiated, false
23340 otherwise. */
23342 bool
23344 {
23347 }
23349 /* [temp.param] Check that template non-type parm TYPE is of an allowable
23350 type. Return zero for ok, nonzero for disallowed. Issue error and
23351 warning messages under control of COMPLAIN. */
23353 static int
23355 {
23370 /* A bound template template parm could later be instantiated to have a valid
23371 nontype parm type via an alias template. */
23377 {
23380 else
23382 type);
23383 }
23385 }
23387 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
23388 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
23390 static bool
23392 {
23393 tree scope;
23395 /* [temp.dep.type]
23397 A type is dependent if it is:
23399 -- a template parameter. Template template parameters are types
23400 for us (since TYPE_P holds true for them) so we handle
23401 them here. */
23405 /* -- a qualified-id with a nested-name-specifier which contains a
23406 class-name that names a dependent type or whose unqualified-id
23407 names a dependent type. */
23411 /* An alias template specialization can be dependent even if the
23412 resulting type is not. */
23416 /* -- a cv-qualified type where the cv-unqualified type is
23417 dependent.
23418 No code is necessary for this bullet; the code below handles
23419 cv-qualified types, and we don't want to strip aliases with
23420 TYPE_MAIN_VARIANT because of DR 1558. */
23421 /* -- a compound type constructed from any dependent type. */
23431 {
23432 tree arg_type;
23437 arg_type;
23442 {
23443 /* A value-dependent noexcept-specifier makes the type dependent. */
23448 }
23450 }
23451 /* -- an array type constructed from any dependent type or whose
23452 size is specified by a constant expression that is
23453 value-dependent.
23455 We checked for type- and value-dependence of the bounds in
23456 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
23458 {
23463 }
23465 /* -- a template-id in which either the template name is a template
23466 parameter ... */
23469 /* ... or any of the template arguments is a dependent type or
23470 an expression that is type-dependent or value-dependent. */
23472 && (any_dependent_template_arguments_p
23476 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
23477 dependent; if the argument of the `typeof' expression is not
23478 type-dependent, then it should already been have resolved. */
23484 /* A template argument pack is dependent if any of its packed
23485 arguments are. */
23487 {
23493 }
23495 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
23496 be template parameters. */
23503 /* The standard does not specifically mention types that are local
23504 to template functions or local classes, but they should be
23505 considered dependent too. For example:
23507 template <int I> void f() {
23508 enum E { a = I };
23509 S<sizeof (E)> s;
23510 }
23512 The size of `E' cannot be known until the value of `I' has been
23513 determined. Therefore, `E' must be considered dependent. */
23517 /* Don't use type_dependent_expression_p here, as it can lead
23518 to infinite recursion trying to determine whether a lambda
23519 nested in a lambda is dependent (c++/47687). */
23523 && (any_dependent_template_arguments_p
23527 /* Other types are non-dependent. */
23529 }
23531 /* Returns TRUE if TYPE is dependent, in the sense of
23532 [temp.dep.type]. Note that a NULL type is considered dependent. */
23534 bool
23536 {
23537 /* If there are no template parameters in scope, then there can't be
23538 any dependent types. */
23540 {
23541 /* If we are not processing a template, then nobody should be
23542 providing us with a dependent type. */
23546 }
23548 /* If the type is NULL, we have not computed a type for the entity
23549 in question; in that case, the type is dependent. */
23553 /* Erroneous types can be considered non-dependent. */
23557 /* Getting here with global_type_node means we improperly called this
23558 function on the TREE_TYPE of an IDENTIFIER_NODE. */
23561 /* If we have not already computed the appropriate value for TYPE,
23562 do so now. */
23564 {
23567 }
23570 }
23572 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
23573 lookup. In other words, a dependent type that is not the current
23574 instantiation. */
23576 bool
23578 {
23581 }
23583 /* T is a SCOPE_REF; return whether we need to consider it
23584 instantiation-dependent so that we can check access at instantiation
23585 time even though we know which member it resolves to. */
23587 static bool
23589 {
23595 else
23597 }
23599 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
23600 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
23601 expression. */
23603 /* Note that this predicate is not appropriate for general expressions;
23604 only constant expressions (that satisfy potential_constant_expression)
23605 can be tested for value dependence. */
23607 bool
23609 {
23613 /* A name declared with a dependent type. */
23618 {
23620 /* A dependent member function of the current instantiation. */
23624 /* A dependent member function of the current instantiation. */
23631 /* A name that has not been looked up -- must be dependent. */
23635 /* A non-type template parm. */
23639 /* A non-type template parm. */
23645 /* A constant with literal type and is initialized
23646 with an expression that is value-dependent.
23648 Note that a non-dependent parenthesized initializer will have
23649 already been replaced with its constant value, so if we see
23650 a TREE_LIST it must be dependent. */
23654 /* cp_finish_decl doesn't fold reference initializers. */
23660 {
23664 }
23672 /* These expressions are value-dependent if the type to which
23673 the cast occurs is dependent or the expression being casted
23674 is value-dependent. */
23675 {
23681 /* A functional cast has a list of operands. */
23684 {
23685 /* If there are no operands, it must be an expression such
23686 as "int()". This should not happen for aggregate types
23687 because it would form non-constant expressions. */
23692 }
23698 }
23703 /* FALLTHRU */
23706 /* A `sizeof' expression is value-dependent if the operand is
23707 type-dependent or is a pack expansion. */
23716 /* An 'encode' expression is value-dependent if the operand is
23717 type-dependent. */
23726 /* All instantiation-dependent expressions should also be considered
23727 value-dependent. */
23735 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
23736 is value-dependent. */
23737 {
23746 }
23749 {
23753 }
23764 {
23768 }
23771 /* Treat all requires-expressions as value-dependent so
23772 we don't try to fold them. */
23779 {
23786 {
23788 /* In a call to a constexpr member function, look through the
23789 implicit ADDR_EXPR on the object argument so that it doesn't
23790 cause the call to be considered value-dependent. We also
23791 look through it in potential_constant_expression. */
23798 }
23800 }
23803 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
23804 type-dependent. */
23809 {
23811 tree val;
23818 }
23821 /* Treat a GNU statement expression as dependent to avoid crashing
23822 under instantiate_non_dependent_expr; it can't be constant. */
23826 /* A constant expression is value-dependent if any subexpression is
23827 value-dependent. */
23829 {
23836 {
23840 {
23843 /* In some cases, some of the operands may be missing.l
23844 (For example, in the case of PREDECREMENT_EXPR, the
23845 amount to increment by may be missing.) That doesn't
23846 make the expression dependent. */
23849 }
23850 }
23854 }
23856 }
23858 /* The expression is not value-dependent. */
23860 }
23862 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
23863 [temp.dep.expr]. Note that an expression with no type is
23864 considered dependent. Other parts of the compiler arrange for an
23865 expression with type-dependent subexpressions to have no type, so
23866 this function doesn't have to be fully recursive. */
23868 bool
23870 {
23877 /* An unresolved name is always dependent. */
23883 /* A fold expression is type-dependent. */
23890 /* Some expression forms are never type-dependent. */
23904 /* The types of these expressions depends only on the type to which
23905 the cast occurs. */
23914 /* The types of these expressions depends only on the type created
23915 by the expression. */
23918 {
23919 /* For NEW_EXPR tree nodes created inside a template, either
23920 the object type itself or a TREE_LIST may appear as the
23921 operand 1. */
23924 /* This is an array type. We need to check array dimensions
23925 as well. */
23927 || value_dependent_expression_p
23929 else
23931 }
23934 {
23938 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23939 contains an identifier associated by name lookup with one or more
23940 declarations declared with a dependent type, or...a
23941 nested-name-specifier or qualified-id that names a member of an
23942 unknown specialization. */
23945 }
23955 {
23956 tree elt;
23960 {
23963 }
23965 }
23967 /* A static data member of the current instantiation with incomplete
23968 array type is type-dependent, as the definition and specializations
23969 can have different bounds. */
23976 /* An array of unknown bound depending on a variadic parameter, eg:
23978 template<typename... Args>
23979 void foo (Args... args)
23980 {
23981 int arr[] = { args... };
23982 }
23984 template<int... vals>
23985 void bar ()
23986 {
23987 int arr[] = { vals... };
23988 }
23990 If the array has no length and has an initializer, it must be that
23991 we couldn't determine its length in cp_complete_array_type because
23992 it is dependent. */
24000 /* A function or variable template-id is type-dependent if it has any
24001 dependent template arguments. Note that we only consider the innermost
24002 template arguments here, since those are the ones that come from the
24003 template-id; the template arguments for the enclosing class do not make it
24004 type-dependent, they only make a member function value-dependent. */
24009 && (any_dependent_template_arguments_p
24013 /* Always dependent, on the number of arguments if nothing else. */
24018 {
24023 {
24029 }
24030 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
24035 {
24040 }
24043 {
24050 }
24060 }
24064 /* Dependent type attributes might not have made it from the decl to
24065 the type yet. */
24071 }
24073 /* [temp.dep.expr]/5: A class member access expression (5.2.5) is
24074 type-dependent if the expression refers to a member of the current
24075 instantiation and the type of the referenced member is dependent, or the
24076 class member access expression refers to a member of an unknown
24077 specialization.
24079 This function returns true if the OBJECT in such a class member access
24080 expression is of an unknown specialization. */
24082 bool
24084 {
24085 /* An IDENTIFIER_NODE can sometimes have a TREE_TYPE, but it's still
24086 dependent. */
24091 }
24093 /* walk_tree callback function for instantiation_dependent_expression_p,
24094 below. Returns non-zero if a dependent subexpression is found. */
24096 static tree
24099 {
24101 {
24102 /* We don't have to worry about decltype currently because decltype
24103 of an instantiation-dependent expr is a dependent type. This
24104 might change depending on the resolution of DR 1172. */
24107 }
24110 {
24111 /* Don't treat an argument list as dependent just because it has no
24112 TREE_TYPE. */
24120 /* Handle expressions with type operands. */
24125 {
24130 {
24133 else
24134 {
24137 }
24138 }
24140 }
24144 /* In a template, finish_class_member_access_expr creates a
24145 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
24146 type-dependent, so that we can check access control at
24147 instantiation time (PR 42277). See also Core issue 1273. */
24154 else
24157 /* Treat statement-expressions as dependent. */
24161 /* Treat requires-expressions as dependent. */
24166 /* Treat calls to function concepts as dependent. */
24172 /* And variable concepts. */
24179 }
24183 else
24185 }
24187 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
24188 sense defined by the ABI:
24190 "An expression is instantiation-dependent if it is type-dependent
24191 or value-dependent, or it has a subexpression that is type-dependent
24192 or value-dependent."
24194 Except don't actually check value-dependence for unevaluated expressions,
24195 because in sizeof(i) we don't care about the value of i. Checking
24196 type-dependence will in turn check value-dependence of array bounds/template
24197 arguments as needed. */
24199 bool
24201 {
24202 tree result;
24213 }
24215 /* As above, but also check value-dependence of the expression as a whole. */
24217 bool
24219 {
24222 }
24224 /* Like type_dependent_expression_p, but it also works while not processing
24225 a template definition, i.e. during substitution or mangling. */
24227 bool
24229 {
24235 }
24237 /* Returns TRUE if ARGS contains a type-dependent expression. */
24239 bool
24241 {
24243 tree arg;
24246 {
24249 }
24251 }
24253 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24254 expressions) contains any type-dependent expressions. */
24256 bool
24258 {
24264 }
24266 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
24267 expressions) contains any value-dependent expressions. */
24269 bool
24271 {
24277 }
24279 /* Returns TRUE if the ARG (a template argument) is dependent. */
24281 bool
24283 {
24287 /* Assume a template argument that was wrongly written by the user
24288 is dependent. This is consistent with what
24289 any_dependent_template_arguments_p [that calls this function]
24290 does. */
24300 {
24303 /* A member template of a dependent class is not necessarily
24304 type-dependent, but it is a dependent template argument because it
24305 will be a member of an unknown specialization to that template. */
24308 }
24310 {
24314 {
24317 }
24320 }
24323 else
24326 }
24328 /* Returns true if ARGS (a collection of template arguments) contains
24329 any types that require structural equality testing. */
24331 bool
24333 {
24343 {
24346 {
24352 {
24353 /* Look inside the argument pack. */
24356 }
24359 {
24372 }
24373 }
24374 }
24377 }
24379 /* Returns true if ARGS (a collection of template arguments) contains
24380 any dependent arguments. */
24382 bool
24384 {
24394 {
24399 }
24402 }
24404 /* Returns TRUE if the template TMPL is type-dependent. */
24406 bool
24408 {
24410 {
24415 }
24417 /* Template template parameters are dependent. */
24421 /* So are names that have not been looked up. */
24425 }
24427 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
24429 bool
24431 {
24434 }
24436 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
24437 are dependent. */
24439 bool
24441 {
24448 {
24470 {
24474 }
24478 {
24482 {
24487 }
24488 }
24489 }
24492 }
24494 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
24495 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
24496 no such TYPE can be found. Note that this function peers inside
24497 uninstantiated templates and therefore should be used only in
24498 extremely limited situations. ONLY_CURRENT_P restricts this
24499 peering to the currently open classes hierarchy (which is required
24500 when comparing types). */
24502 tree
24504 {
24505 tree scope;
24506 tree name;
24507 tree decl;
24509 tree pushed_scope;
24510 tree result;
24515 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
24516 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
24517 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
24518 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
24519 identifier of the TYPENAME_TYPE anymore.
24520 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
24521 TYPENAME_TYPE instead, we avoid messing up with a possible
24522 typedef variant case. */
24525 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
24526 it first before we can figure out what NAME refers to. */
24528 {
24530 /* Given a class template A with a dependent base with nested type C,
24531 typedef typename A::C::C C will land us here, as trying to resolve
24532 the initial A::C leads to the local C typedef, which leads back to
24533 A::C::C. So we break the recursion now. */
24535 else
24537 }
24538 /* If we don't know what SCOPE refers to, then we cannot resolve the
24539 TYPENAME_TYPE. */
24542 /* If this is a typedef, we don't want to look inside (c++/11987). */
24545 /* If SCOPE isn't the template itself, it will not have a valid
24546 TYPE_FIELDS list. */
24548 /* scope is either the template itself or a compatible instantiation
24549 like X<T>, so look up the name in the original template. */
24551 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
24553 /* If scope has no fields, it can't be a current instantiation. Check this
24554 before currently_open_class to avoid infinite recursion (71515). */
24557 /* If the SCOPE is not the current instantiation, there's no reason
24558 to look inside it. */
24561 /* Enter the SCOPE so that name lookup will be resolved as if we
24562 were in the class definition. In particular, SCOPE will no
24563 longer be considered a dependent type. */
24565 /* Look up the declaration. */
24567 tf_warning_or_error);
24571 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
24572 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
24577 {
24581 }
24584 {
24585 tree tmpl;
24586 tree args;
24587 /* Obtain the template and the arguments. */
24590 /* Instantiate the template. */
24596 }
24598 /* Leave the SCOPE. */
24602 /* If we failed to resolve it, return the original typename. */
24606 /* If lookup found a typename type, resolve that too. */
24608 {
24609 /* Ill-formed programs can cause infinite recursion here, so we
24610 must catch that. */
24614 }
24616 /* Qualify the resulting type. */
24622 }
24624 /* EXPR is an expression which is not type-dependent. Return a proxy
24625 for EXPR that can be used to compute the types of larger
24626 expressions containing EXPR. */
24628 tree
24630 {
24631 tree inner_expr;
24633 /* When checking, try to get a constant value for all non-dependent
24634 expressions in order to expose bugs in *_dependent_expression_p
24635 and constexpr. This can affect code generation, see PR70704, so
24636 only do this for -fchecking=2. */
24639 /* Don't do this during nsdmi parsing as it can lead to
24640 unexpected recursive instantiations. */
24642 /* Don't do this during concept expansion either and for
24643 the same reason. */
24647 /* Preserve OVERLOADs; the functions must be available to resolve
24648 types. */
24659 /* There is no need to return a proxy for a variable. */
24662 /* Preserve string constants; conversions from string constants to
24663 "char *" are allowed, even though normally a "const char *"
24664 cannot be used to initialize a "char *". */
24667 /* Preserve void and arithmetic constants, as an optimization -- there is no
24668 reason to create a new node. */
24673 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
24674 There is at least one place where we want to know that a
24675 particular expression is a throw-expression: when checking a ?:
24676 expression, there are special rules if the second or third
24677 argument is a throw-expression. */
24681 /* Don't wrap an initializer list, we need to be able to look inside. */
24685 /* Don't wrap a dummy object, we need to be able to test for it. */
24704 /* If the type is unknown, it can't really be non-dependent */
24707 /* Otherwise, build a NON_DEPENDENT_EXPR. */
24709 }
24711 /* ARGS is a vector of expressions as arguments to a function call.
24712 Replace the arguments with equivalent non-dependent expressions.
24713 This modifies ARGS in place. */
24715 void
24717 {
24719 tree arg;
24722 {
24726 }
24727 }
24729 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
24730 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
24731 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
24733 static tree
24735 {
24749 }
24751 tree
24753 {
24755 }
24757 tree
24759 {
24761 }
24763 /* Return a C++17 deduction placeholder for class template TMPL. */
24765 tree
24767 {
24771 }
24773 /* Make a "constrained auto" type-specifier. This is an
24774 auto type with constraints that must be associated after
24775 deduction. The constraint is formed from the given
24776 CONC and its optional sequence of arguments, which are
24777 non-null if written as partial-concept-id. */
24779 tree
24781 {
24784 /* Build the constraint. */
24792 /* Our canonical type depends on the constraint. */
24795 /* Attach the constraint to the type declaration. */
24798 }
24800 /* Given type ARG, return std::initializer_list<ARG>. */
24802 static tree
24804 {
24808 {
24812 }
24818 }
24820 /* Replace auto in TYPE with std::initializer_list<auto>. */
24822 static tree
24824 {
24831 }
24833 /* Hash traits for hashing possibly constrained 'auto'
24834 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
24837 {
24840 };
24842 /* Hash the 'auto' T. */
24844 inline hashval_t
24846 {
24848 /* Matching constrained-type-specifiers denote the same template
24849 parameter, so hash the constraint. */
24851 else
24852 /* But unconstrained autos are all separate, so just hash the pointer. */
24854 }
24856 /* Compare two 'auto's. */
24860 {
24867 /* Two unconstrained autos are distinct. */
24872 }
24874 /* for_each_template_parm callback for extract_autos: if t is a (possibly
24875 constrained) auto, add it to the vector. */
24877 static int
24879 {
24882 {
24883 /* All the autos were built with index 0; fix that up now. */
24887 /* If this is a repeated constrained-type-specifier, use the index we
24888 chose before. */
24890 else
24891 {
24892 /* Otherwise this is new, so use the current count. */
24895 }
24897 }
24899 /* Always keep walking. */
24901 }
24903 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
24904 says they can appear anywhere in the type. */
24906 static tree
24908 {
24917 {
24922 }
24925 }
24927 /* The stem for deduction guide names. */
24930 /* Return the name for a deduction guide for class template TMPL. */
24932 tree
24934 {
24945 }
24947 /* True if NAME is the name of a deduction guide. */
24949 bool
24951 {
24955 }
24957 /* True if FN is a deduction guide. */
24959 bool
24961 {
24966 }
24968 /* True if FN is the copy deduction guide, i.e. A(A)->A. */
24970 bool
24972 {
24979 }
24981 /* True if FN is a guide generated from a constructor template. */
24983 bool
24985 {
24990 {
24993 }
24995 }
24997 /* OLDDECL is a _DECL for a template parameter. Return a similar parameter at
24998 LEVEL:INDEX, using tsubst_args and complain for substitution into non-type
24999 template parameter types. Note that the handling of template template
25000 parameters relies on current_template_parms being set appropriately for the
25001 new template. */
25003 static tree
25006 {
25009 tree newtype;
25012 {
25019 }
25020 else
25024 tree newdecl
25029 tree newidx;
25032 {
25042 {
25047 // First create a copy (ttargs) of tsubst_args with an
25048 // additional level for the template template parameter's own
25049 // template parameters (ttparms).
25050 tree ttparms = (INNERMOST_TEMPLATE_PARMS
25058 // Substitute ttargs into ttparms to fix references to
25059 // other template parameters.
25061 complain);
25062 // Now substitute again with args based on tparms, to reduce
25063 // the level of the ttparms.
25066 complain);
25067 // Finally, tack the adjusted parms onto tparms.
25069 current_template_parms);
25071 }
25072 }
25073 else
25074 {
25076 tree newconst
25088 }
25091 }
25093 /* Returns a C++17 class deduction guide template based on the constructor
25094 CTOR. As a special case, CTOR can be a RECORD_TYPE for an implicit default
25095 guide, or REFERENCE_TYPE for an implicit copy/move guide. */
25097 static tree
25099 {
25103 location_t loc;
25106 {
25110 {
25113 }
25114 else
25124 }
25125 else
25126 {
25130 tree fn_tmpl;
25132 {
25135 }
25136 else
25140 /* If type is a member class template, DECL_TI_ARGS (ctor) will have
25141 fully specialized args for the enclosing class. Strip those off, as
25142 the deduction guide won't have those template parameters. */
25145 /* Discard the 'this' parameter. */
25153 {
25156 /* For a member template constructor, we need to flatten the two
25157 template parameter lists into one, and then adjust the function
25158 signature accordingly. This gets...complicated. */
25162 /* For a member template we should have two levels of parms/args, one
25163 for the class and one for the constructor. We stripped
25164 specialized args for further enclosing classes above. */
25168 /* Template args for translating references to the two-level template
25169 parameters into references to the one-level template parameters we
25170 are creating. */
25175 /* Template parms for the constructor template. */
25178 /* Template parms for the class template. */
25182 /* Template parms for the deduction guide start as a copy of the
25183 template parms for the class. We set current_template_parms for
25184 lookup_template_class_1. */
25190 /* Now we need to rewrite the constructor parms to append them to the
25191 class parms. */
25193 {
25208 }
25210 /* Now we have a final set of template parms to substitute into the
25211 function signature. */
25221 }
25222 }
25225 {
25226 /* Copy the parms so we can set DECL_PRIMARY_TEMPLATE. */
25230 }
25234 FUNCTION_DECL,
25251 }
25253 /* Deduce template arguments for the class template placeholder PTYPE for
25254 template TMPL based on the initializer INIT, and return the resulting
25255 type. */
25257 static tree
25259 tsubst_flags_t complain)
25260 {
25262 {
25263 /* We should have handled this in the caller. */
25269 }
25281 else
25292 /* Prune explicit deduction guides in copy-initialization context. */
25294 {
25300 {
25301 /* Found a nonconverting guide, prune the candidates. */
25308 }
25309 }
25314 {
25317 }
25321 // FIXME cache artificial deduction guides
25324 {
25329 else
25333 }
25336 {
25345 {
25350 else
25352 }
25353 }
25356 {
25358 " of %qT, as it has no non-explicit deduction guides or "
25361 }
25367 {
25373 }
25379 }
25381 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25382 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
25384 tree
25386 {
25388 tf_warning_or_error,
25389 adc_unspecified);
25390 }
25392 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
25393 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
25394 The CONTEXT determines the context in which auto deduction is performed
25395 and is used to control error diagnostics. FLAGS are the LOOKUP_* flags.
25396 OUTER_TARGS are used during template argument deduction
25397 (context == adc_unify) to properly substitute the result, and is ignored
25398 in other contexts.
25400 For partial-concept-ids, extra args may be appended to the list of deduced
25401 template arguments prior to determining constraint satisfaction. */
25403 tree
25407 {
25408 tree targs;
25415 /* Defining a subset of type-dependent expressions that we can deduce
25416 from ahead of time isn't worth the trouble. */
25420 /* C++17 class template argument deduction. */
25424 /* Nothing we can do with this, even in deduction context. */
25427 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
25428 with either a new invented type template parameter U or, if the
25429 initializer is a braced-init-list (8.5.4), with
25430 std::initializer_list<U>. */
25432 {
25437 else
25438 {
25440 {
25444 "for deduction to %<std::initializer_list%>, use copy-"
25446 }
25448 }
25449 }
25460 /* [dcl.decomp]/1 - if decomposition declaration has no ref-qualifiers
25461 and initializer has array type, deduce cv-qualified array type. */
25463 complain);
25465 {
25474 {
25478 }
25479 }
25480 else
25481 {
25483 tree tparms;
25487 else
25488 {
25492 }
25499 {
25501 /* Try again at instantiation time. */
25505 /* If type is error_mark_node a diagnostic must have been
25506 emitted by now. Also, having a mention to '<type error>'
25507 in the diagnostic is not really useful to the user. */
25508 {
25512 else
25517 }
25519 }
25520 }
25522 /* Check any placeholder constraints against the deduced type. */
25525 {
25526 /* Use the deduced type to check the associated constraints. If we
25527 have a partial-concept-id, rebuild the argument list so that
25528 we check using the extra arguments. */
25532 {
25535 }
25536 else
25539 {
25541 {
25543 {
25561 }
25563 }
25565 }
25566 }
25572 }
25574 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
25575 result. */
25577 tree
25579 {
25581 {
25587 /* In an abbreviated function template we didn't know we were dealing
25588 with a function template when we saw the auto return type, so update
25589 it to have the correct level. */
25591 }
25593 }
25595 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
25596 'decltype(auto)' or a deduced class template. */
25598 bool
25600 {
25606 else
25608 }
25610 /* for_each_template_parm callback for type_uses_auto. */
25612 int
25614 {
25616 }
25618 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
25619 a use of `auto'. Returns NULL_TREE otherwise. */
25621 tree
25623 {
25627 {
25628 /* The Concepts TS allows multiple autos in one type-specifier; just
25629 return the first one we find, do_auto_deduction will collect all of
25630 them. */
25634 else
25636 }
25637 else
25639 }
25641 /* For a given template T, return the vector of typedefs referenced
25642 in T for which access check is needed at T instantiation time.
25643 T is either a FUNCTION_DECL or a RECORD_TYPE.
25644 Those typedefs were added to T by the function
25645 append_type_to_template_for_access_check. */
25649 {
25650 tree ti;
25661 {
25666 }
25669 }
25671 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
25672 tied to T. That list of typedefs will be access checked at
25673 T instantiation time.
25674 T is either a FUNCTION_DECL or a RECORD_TYPE.
25675 TYPE_DECL is a TYPE_DECL node representing a typedef.
25676 SCOPE is the scope through which TYPE_DECL is accessed.
25677 LOCATION is the location of the usage point of TYPE_DECL.
25679 This function is a subroutine of
25680 append_type_to_template_for_access_check. */
25682 static void
25684 tree type_decl,
25685 tree scope,
25686 location_t location)
25687 {
25688 qualified_typedef_usage_t typedef_usage;
25689 tree ti;
25696 && type_decl
25710 }
25712 /* Append TYPE_DECL to the template TEMPL.
25713 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
25714 At TEMPL instanciation time, TYPE_DECL will be checked to see
25715 if it can be accessed through SCOPE.
25716 LOCATION is the location of the usage point of TYPE_DECL.
25718 e.g. consider the following code snippet:
25720 class C
25721 {
25722 typedef int myint;
25723 };
25725 template<class U> struct S
25726 {
25727 C::myint mi; // <-- usage point of the typedef C::myint
25728 };
25730 S<char> s;
25732 At S<char> instantiation time, we need to check the access of C::myint
25733 In other words, we need to check the access of the myint typedef through
25734 the C scope. For that purpose, this function will add the myint typedef
25735 and the scope C through which its being accessed to a list of typedefs
25736 tied to the template S. That list will be walked at template instantiation
25737 time and access check performed on each typedefs it contains.
25738 Note that this particular code snippet should yield an error because
25739 myint is private to C. */
25741 void
25743 tree type_decl,
25744 tree scope,
25745 location_t location)
25746 {
25752 /* Make sure we don't append the type to the template twice. */
25759 }
25761 /* Convert the generic type parameters in PARM that match the types given in the
25762 range [START_IDX, END_IDX) from the current_template_parms into generic type
25763 packs. */
25765 tree
25767 {
25778 {
25779 /* Create a distinct parameter pack type from the current parm and add it
25780 to the replacement args to tsubst below into the generic function
25781 parameter. */
25796 }
25802 /* If there are more levels then build up the replacement with the outer
25803 template parms. */
25807 replacement);
25810 }
25812 /* Entries in the decl_constraint hash table. */
25814 {
25815 tree decl;
25816 tree ci;
25817 };
25819 /* Hashing function and equality for constraint entries. */
25821 {
25823 {
25825 }
25828 {
25830 }
25831 };
25833 /* A mapping from declarations to constraint information. Note that
25834 both templates and their underlying declarations are mapped to the
25835 same constraint information.
25837 FIXME: This is defined in pt.c because garbage collection
25838 code is not being generated for constraint.cc. */
25842 /* Returns the template constraints of declaration T. If T is not
25843 constrained, return NULL_TREE. Note that T must be non-null. */
25845 tree
25847 {
25858 else
25860 }
25862 /* Associate the given constraint information CI with the declaration
25863 T. If T is a template, then the constraints are associated with
25864 its underlying declaration. Don't build associations if CI is
25865 NULL_TREE. */
25867 void
25869 {
25881 }
25883 /* Remove the associated constraints of the declaration T. */
25885 void
25887 {
25896 }
25898 /* Memoized satisfaction results for declarations. This
25899 maps the pair (constraint_info, arguments) to the result computed
25900 by constraints_satisfied_p. */
25903 {
25904 tree ci;
25905 tree args;
25906 tree result;
25907 };
25909 /* Hashing function and equality for constraint entries. */
25912 {
25914 {
25917 }
25920 {
25922 }
25923 };
25925 /* Memoized satisfaction results for concept checks. */
25928 {
25929 tree tmpl;
25930 tree args;
25931 tree result;
25932 };
25934 /* Hashing function and equality for constraint entries. */
25937 {
25939 {
25941 }
25944 {
25949 }
25950 };
25955 /* Search for a memoized satisfaction result. Returns one of the
25956 truth value nodes if previously memoized, or NULL_TREE otherwise. */
25958 tree
25960 {
25965 else
25967 }
25969 /* Memoize the result of a satisfication test. Returns the saved result. */
25971 tree
25973 {
25980 }
25982 /* Search for a memoized satisfaction result for a concept. */
25984 tree
25986 {
25991 else
25993 }
25995 /* Memoize the result of a concept check. Returns the saved result. */
25997 tree
25999 {
26006 }
26010 /* Returns a prior concept specialization. This returns the substituted
26011 and normalized constraints defined by the concept. */
26013 tree
26015 {
26020 else
26022 }
26024 /* Save a concept expansion for later. */
26026 tree
26028 {
26035 }
26037 static hashval_t
26039 {
26048 }
26050 /* Compare the constraints of two subsumption entries. The LEFT1 and
26051 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
26052 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
26054 static bool
26056 {
26064 }
26066 /* Key/value pair for learning and memoizing subsumption results. This
26067 associates a pair of check constraints (including arguments) with
26068 a boolean value indicating the result. */
26071 {
26072 tree t1;
26073 tree t2;
26075 };
26077 /* Hashing function and equality for constraint entries. */
26080 {
26082 {
26084 }
26087 {
26092 }
26093 };
26097 /* Search for a previously cached subsumption result. */
26101 {
26106 else
26108 }
26110 /* Save a subsumption result. */
26112 bool
26114 {
26121 }
26123 /* Set up the hash table for constraint association. */
26125 void
26127 {
26136 }
26138 /* __integer_pack(N) in a pack expansion expands to a sequence of numbers from
26139 0..N-1. */
26141 void
26143 {
26146 integer_type_node,
26147 NULL_TREE),
26151 }
26153 /* Set up the hash tables for template instantiations. */
26155 void
26157 {
26163 }
26165 /* Print stats about the template hash tables for -fstats. */
26167 void
26169 {
26178 }