| blob | db947cc632e382424957db96fc7cb966af658440 |
1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2015 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". */
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
61 };
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
81 // -------------------------------------------------------------------------- //
82 // Local Specialization Stack
83 //
84 // Implementation of the RAII helper for creating new local
85 // specializations.
88 {
90 }
93 {
96 }
98 /* True if we've recursed into fn_type_unification too many times. */
102 {
103 tree tmpl;
104 tree args;
105 tree spec;
106 };
109 {
112 };
118 /* Contains canonical template parameter types. The vector is indexed by
119 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
120 TREE_LIST, whose TREE_VALUEs contain the canonical template
121 parameters of various types and levels. */
124 #define UNIFY_ALLOW_NONE 0
125 #define UNIFY_ALLOW_MORE_CV_QUAL 1
126 #define UNIFY_ALLOW_LESS_CV_QUAL 2
127 #define UNIFY_ALLOW_DERIVED 4
128 #define UNIFY_ALLOW_INTEGER 8
129 #define UNIFY_ALLOW_OUTER_LEVEL 16
130 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
131 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
134 tbr_incomplete_type,
135 tbr_ambiguous_baseclass,
136 tbr_success
137 };
160 tree);
218 location_t);
225 /* Make the current scope suitable for access checking when we are
226 processing T. T can be FUNCTION_DECL for instantiated function
227 template, VAR_DECL for static member variable, or TYPE_DECL for
228 alias template (needed by instantiate_decl). */
230 static void
232 {
240 else
244 {
245 saved_access_scope = tree_cons
248 }
249 }
251 /* Restore the scope set up by push_access_scope. T is the node we
252 are processing. */
254 static void
256 {
258 {
261 }
265 else
267 }
269 /* Do any processing required when DECL (a member template
270 declaration) is finished. Returns the TEMPLATE_DECL corresponding
271 to DECL, unless it is a specialization, in which case the DECL
272 itself is returned. */
274 tree
276 {
283 {
284 tree type;
292 {
296 }
298 }
302 {
304 {
307 }
308 else
310 }
311 else
315 }
317 /* Create a template info node. */
319 tree
321 {
326 }
328 /* Return the template info node corresponding to T, whatever T is. */
330 tree
332 {
353 }
355 /* Returns the template nesting level of the indicated class TYPE.
357 For example, in:
358 template <class T>
359 struct A
360 {
361 template <class U>
362 struct B {};
363 };
365 A<T>::B<U> has depth two, while A<T> has depth one.
366 Both A<T>::B<int> and A<int>::B<U> have depth one, if
367 they are instantiations, not specializations.
369 This function is guaranteed to return 0 if passed NULL_TREE so
370 that, for example, `template_class_depth (current_class_type)' is
371 always safe. */
373 int
375 {
382 {
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 {
446 /* Make a CONST_DECL as is done in process_template_parm.
447 It is ugly that we recreate this here; the original
448 version built in process_template_parm is no longer
449 available. */
459 }
464 }
465 }
466 }
468 /* Restore the template parameter context for a member template, a
469 friend template defined in a class definition, or a non-template
470 member of template class. */
472 void
474 {
475 tree parms;
480 {
483 /* Disregard full specializations (c++/60999). */
486 }
489 {
494 {
497 }
500 }
502 /* Remember how many levels of template parameters we pushed so that
503 we can pop them later. */
505 }
507 /* Undo the effects of maybe_begin_member_template_processing. */
509 void
511 {
520 {
524 }
525 }
527 /* Return a new template argument vector which contains all of ARGS,
528 but has as its innermost set of arguments the EXTRA_ARGS. */
530 static tree
532 {
533 tree new_args;
551 }
553 /* Like add_to_template_args, but only the outermost ARGS are added to
554 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
555 (EXTRA_ARGS) levels are added. This function is used to combine
556 the template arguments from a partial instantiation with the
557 template arguments used to attain the full instantiation from the
558 partial instantiation. */
560 static tree
562 {
563 tree new_args;
565 /* If there are more levels of EXTRA_ARGS than there are ARGS,
566 something very fishy is going on. */
569 /* If *all* the new arguments will be the EXTRA_ARGS, just return
570 them. */
574 /* For the moment, we make ARGS look like it contains fewer levels. */
579 /* Now, we restore ARGS to its full dimensions. */
583 }
585 /* Return the N levels of innermost template arguments from the ARGS. */
587 tree
589 {
590 tree new_args;
596 /* If N is 1, just return the innermost set of template arguments. */
600 /* If we're not removing anything, just return the arguments we were
601 given. */
607 /* Make a new set of arguments, not containing the outer arguments. */
614 }
616 /* The inverse of get_innermost_template_args: Return all but the innermost
617 EXTRA_LEVELS levels of template arguments from the ARGS. */
619 static tree
621 {
622 tree new_args;
628 /* If N is 1, just return the outermost set of template arguments. */
632 /* If we're not removing anything, just return the arguments we were
633 given. */
638 /* Make a new set of arguments, not containing the inner arguments. */
645 }
647 /* We've got a template header coming up; push to a new level for storing
648 the parms. */
650 void
652 {
653 /* We use a non-tag-transparent scope here, which causes pushtag to
654 put tags in this scope, rather than in the enclosing class or
655 namespace scope. This is the right thing, since we want
656 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
657 global template class, push_template_decl handles putting the
658 TEMPLATE_DECL into top-level scope. For a nested template class,
659 e.g.:
661 template <class T> struct S1 {
662 template <class T> struct S2 {};
663 };
665 pushtag contains special code to call pushdecl_with_scope on the
666 TEMPLATE_DECL for S2. */
672 /* Add a dummy parameter level while we process the parameter list. */
673 current_template_parms
676 current_template_parms);
677 }
679 /* This routine is called when a specialization is declared. If it is
680 invalid to declare a specialization here, an error is reported and
681 false is returned, otherwise this routine will return true. */
683 static bool
685 {
688 /* [temp.expl.spec]
690 An explicit specialization shall be declared in the namespace of
691 which the template is a member, or, for member templates, in the
692 namespace of which the enclosing class or enclosing class
693 template is a member. An explicit specialization of a member
694 function, member class or static data member of a class template
695 shall be declared in the namespace of which the class template
696 is a member. */
698 {
701 }
703 /* [temp.expl.spec]
705 In an explicit specialization declaration for a member of a class
706 template or a member template that appears in namespace scope,
707 the member template and some of its enclosing class templates may
708 remain unspecialized, except that the declaration shall not
709 explicitly specialize a class member template if its enclosing
710 class templates are not explicitly specialized as well. */
712 {
715 }
718 }
720 /* We've just seen template <>. */
722 bool
724 {
728 }
730 /* Called at then end of processing a declaration preceded by
731 template<>. */
733 void
735 {
738 }
740 /* Any template <>'s that we have seen thus far are not referring to a
741 function specialization. */
743 void
745 {
748 }
750 /* We've just seen a template header. If SPECIALIZATION is nonzero,
751 it was of the form template <>. */
753 static void
755 {
757 template_header_count++;
758 }
760 /* We're beginning an explicit instantiation. */
762 void
764 {
767 }
770 void
772 {
775 }
777 /* An explicit specialization or partial specialization of TMPL is being
778 declared. Check that the namespace in which the specialization is
779 occurring is permissible. Returns false iff it is invalid to
780 specialize TMPL in the current namespace. */
782 static bool
784 {
787 /* [tmpl.expl.spec]
789 An explicit specialization shall be declared in the namespace of
790 which the template is a member, or, for member templates, in the
791 namespace of which the enclosing class or enclosing class
792 template is a member. An explicit specialization of a member
793 function, member class or static data member of a class template
794 shall be declared in the namespace of which the class template is
795 a member. */
798 {
801 }
803 /* Same or super-using namespace. */
805 else
806 {
812 }
813 }
815 /* SPEC is an explicit instantiation. Check that it is valid to
816 perform this explicit instantiation in the current namespace. */
818 static void
820 {
821 tree ns;
823 /* DR 275: An explicit instantiation shall appear in an enclosing
824 namespace of its template. */
830 }
832 // Returns the type of a template specialization only if that
833 // specialization needs to be defined. Otherwise (e.g., if the type has
834 // already been defined), the function returns NULL_TREE.
835 static tree
837 {
838 // An implicit instantiation of an incomplete type implies
839 // the definition of a new class template.
840 //
841 // template<typename T>
842 // struct S;
843 //
844 // template<typename T>
845 // struct S<T*>;
846 //
847 // Here, S<T*> is an implicit instantiation of S whose type
848 // is incomplete.
852 // It can also be the case that TYPE is a completed specialization.
853 // Continuing the previous example, suppose we also declare:
854 //
855 // template<typename T>
856 // requires Integral<T>
857 // struct S<T*>;
858 //
859 // Here, S<T*> refers to the specialization S<T*> defined
860 // above. However, we need to differentiate definitions because
861 // we intend to define a new partial specialization. In this case,
862 // we rely on the fact that the constraints are different for
863 // this declaration than that above.
864 //
865 // Note that we also get here for injected class names and
866 // late-parsed template definitions. We must ensure that we
867 // do not create new type declarations for those cases.
869 {
873 // If there are no template parameters, this cannot be a new
874 // partial template specializtion?
878 // If the constraints are not the same as those of the primary
879 // then, we can probably create a new specialization.
887 // Also, if there's a pre-existing specialization with matching
888 // constraints, then this also isn't new.
891 {
899 }
901 // Create a new type node (and corresponding type decl)
902 // for the newly declared specialization.
908 /* We only need a separate type node for storing the definition of this
909 partial specialization; uses of S<T*> are unconstrained, so all are
910 equivalent. So keep TYPE_CANONICAL the same. */
913 // Build the corresponding type decl.
919 }
922 }
924 /* The TYPE is being declared. If it is a template type, that means it
925 is a partial specialization. Do appropriate error-checking. */
927 tree
929 {
930 tree context;
935 /* A lambda that appears in specialization context is not itself a
936 specialization. */
941 {
945 }
950 {
955 else
958 }
960 {
961 /* This is for ordinary explicit specialization and partial
962 specialization of a template class such as:
964 template <> class C<int>;
966 or:
968 template <class T> class C<T*>;
970 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
973 {
980 {
985 }
986 }
992 /* Trying to define a specialization either without a template<> header
993 or in an inappropriate place. We've already given an error, so just
994 bail now so we don't actually define the specialization. */
996 }
1002 {
1003 /* This is for an explicit specialization of member class
1004 template according to [temp.expl.spec/18]:
1006 template <> template <class U> class C<int>::D;
1008 The context `C<int>' must be an implicit instantiation.
1009 Otherwise this is just a member class template declared
1010 earlier like:
1012 template <> class C<int> { template <class U> class D; };
1013 template <> template <class U> class C<int>::D;
1015 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1016 while in the second case, `C<int>::D' is a primary template
1017 and `C<T>::D' may not exist. */
1021 {
1022 tree t;
1027 {
1032 }
1034 /* Check for invalid specialization after instantiation:
1036 template <> template <> class C<int>::D<int>;
1037 template <> template <class U> class C<int>::D; */
1041 {
1045 {
1046 /* We already have a full specialization of this partial
1047 instantiation, or a full specialization has been
1048 looked up but not instantiated. Reassign it to the
1049 new member specialization template. */
1050 spec_entry elt;
1062 spec_entry **slot
1067 }
1068 else
1069 /* But if we've had an implicit instantiation, that's a
1070 problem ([temp.expl.spec]/6). */
1073 }
1075 /* Mark TYPE as a specialization. And as a result, we only
1076 have one level of template argument for the innermost
1077 class template. */
1082 }
1083 }
1085 {
1086 /* Someday C++0x may allow for enum template specialization. */
1091 else
1092 {
1095 }
1096 }
1099 }
1101 /* Returns nonzero if we can optimize the retrieval of specializations
1102 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1103 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1107 {
1110 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1111 parameter. */
1113 /* The optimized lookup depends on the fact that the
1114 template arguments for the member function template apply
1115 purely to the containing class, which is not true if the
1116 containing class is an explicit or partial
1117 specialization. */
1121 /* It is possible to have a template that is not a member
1122 template and is not a member of a template class:
1124 template <typename T>
1125 struct S { friend A::f(); };
1127 Here, the friend function is a template, but the context does
1128 not have template information. The optimized lookup relies
1129 on having ARGS be the template arguments for both the class
1130 and the function template. */
1132 }
1134 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1135 gone through coerce_template_parms by now. */
1137 static void
1139 {
1140 #ifdef ENABLE_CHECKING
1143 {
1146 {
1153 /* Allow typedefs on the type of a non-type argument, since a
1155 else
1157 }
1158 }
1160 #endif
1161 }
1163 /* Retrieve the specialization (in the sense of [temp.spec] - a
1164 specialization is either an instantiation or an explicit
1165 specialization) of TMPL for the given template ARGS. If there is
1166 no such specialization, return NULL_TREE. The ARGS are a vector of
1167 arguments, or a vector of vectors of arguments, in the case of
1168 templates with more than one level of parameters.
1170 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1171 then we search for a partial specialization matching ARGS. This
1172 parameter is ignored if TMPL is not a class template.
1174 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1175 result is a NONTYPE_ARGUMENT_PACK. */
1177 static tree
1179 {
1189 /* There should be as many levels of arguments as there are
1190 levels of parameters. */
1199 {
1200 tree class_template;
1201 tree class_specialization;
1203 tree fns;
1206 /* The template arguments actually apply to the containing
1207 class. Find the class specialization with those
1208 arguments. */
1210 class_specialization
1214 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1215 for the specialization. */
1219 /* Iterate through the methods with the indicated name, looking
1220 for the one that has an instance of TMPL. */
1223 {
1226 /* using-declarations can add base methods to the method vec,
1227 and we don't want those here. */
1230 }
1232 }
1233 else
1234 {
1236 spec_entry elt;
1245 else
1253 }
1256 }
1258 /* Like retrieve_specialization, but for local declarations. */
1260 tree
1262 {
1268 }
1270 /* Returns nonzero iff DECL is a specialization of TMPL. */
1272 int
1274 {
1275 tree t;
1278 {
1284 }
1285 else
1286 {
1295 }
1298 }
1300 /* Returns nonzero iff DECL is a specialization of friend declaration
1301 FRIEND_DECL according to [temp.friend]. */
1303 bool
1305 {
1312 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1313 of a template class, we want to check if DECL is a specialization
1314 if this. */
1318 {
1319 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1322 }
1327 /* There is nothing to do if this is not a template friend. */
1334 /* [temp.friend/6]
1335 A member of a class template may be declared to be a friend of a
1336 non-template class. In this case, the corresponding member of
1337 every specialization of the class template is a friend of the
1338 class granting friendship.
1340 For example, given a template friend declaration
1342 template <class T> friend void A<T>::f();
1344 the member function below is considered a friend
1346 template <> struct A<int> {
1347 void f();
1348 };
1350 For this type of template friend, TEMPLATE_DEPTH below will be
1351 nonzero. To determine if DECL is a friend of FRIEND, we first
1352 check if the enclosing class is a specialization of another. */
1359 {
1360 /* Next, we check the members themselves. In order to handle
1361 a few tricky cases, such as when FRIEND_DECL's are
1363 template <class T> friend void A<T>::g(T t);
1364 template <class T> template <T t> friend void A<T>::h();
1366 and DECL's are
1368 void A<int>::g(int);
1369 template <int> void A<int>::h();
1371 we need to figure out ARGS, the template arguments from
1372 the context of DECL. This is required for template substitution
1373 of `T' in the function parameter of `g' and template parameter
1374 of `h' in the above examples. Here ARGS corresponds to `int'. */
1381 {
1383 {
1386 else
1388 current_depth++;
1389 }
1391 }
1394 {
1396 tree friend_type;
1397 tree decl_type;
1398 tree friend_args_type;
1399 tree decl_args_type;
1401 /* Make sure that both DECL and FRIEND_DECL are templates or
1402 non-templates. */
1408 {
1409 /* If both are templates, check template parameter list. */
1410 tree friend_parms
1415 friend_parms))
1419 }
1420 else
1428 /* Check if return types match. */
1432 /* Check if function parameter types match, ignoring the
1433 `this' parameter. */
1442 }
1443 else
1444 {
1445 /* DECL is a TYPE_DECL */
1449 /* Make sure that both DECL and FRIEND_DECL are templates or
1450 non-templates. */
1451 is_template
1458 {
1459 tree friend_parms;
1460 /* If both are templates, check the name of the two
1461 TEMPLATE_DECL's first because is_friend didn't. */
1466 /* Now check template parameter list. */
1467 friend_parms
1470 return comp_template_parms
1472 friend_parms);
1473 }
1474 else
1477 }
1478 }
1480 }
1482 /* Register the specialization SPEC as a specialization of TMPL with
1483 the indicated ARGS. IS_FRIEND indicates whether the specialization
1484 is actually just a friend declaration. Returns SPEC, or an
1485 equivalent prior declaration, if available.
1487 We also store instantiations of field packs in the hash table, even
1488 though they are not themselves templates, to make lookup easier. */
1490 static tree
1492 hashval_t hash)
1493 {
1494 tree fn;
1496 spec_entry elt;
1504 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1505 register it; we want the corresponding TEMPLATE_DECL instead.
1506 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1507 the more obvious `uses_template_parms (spec)' to avoid problems
1508 with default function arguments. In particular, given
1509 something like this:
1511 template <class T> void f(T t1, T t = T())
1513 the default argument expression is not substituted for in an
1514 instantiation unless and until it is actually needed. */
1518 /* We don't put these specializations in the hash table, but we might
1519 want to give an error about a mismatch. */
1521 else
1522 {
1530 slot =
1534 else
1536 }
1538 /* We can sometimes try to re-register a specialization that we've
1539 already got. In particular, regenerate_decl_from_template calls
1540 duplicate_decls which will update the specialization list. But,
1541 we'll still get called again here anyhow. It's more convenient
1542 to simply allow this than to try to prevent it. */
1546 {
1548 {
1551 {
1553 fn);
1555 }
1556 else
1557 {
1558 tree clone;
1559 /* This situation should occur only if the first
1560 specialization is an implicit instantiation, the
1561 second is an explicit specialization, and the
1562 implicit instantiation has not yet been used. That
1563 situation can occur if we have implicitly
1564 instantiated a member function and then specialized
1565 it later.
1567 We can also wind up here if a friend declaration that
1568 looked like an instantiation turns out to be a
1569 specialization:
1571 template <class T> void foo(T);
1572 class S { friend void foo<>(int) };
1573 template <> void foo(int);
1575 We transform the existing DECL in place so that any
1576 pointers to it become pointers to the updated
1577 declaration.
1579 If there was a definition for the template, but not
1580 for the specialization, we want this to look as if
1581 there were no definition, and vice versa. */
1584 /* The call to duplicate_decls will have applied
1585 [temp.expl.spec]:
1587 An explicit specialization of a function template
1588 is inline only if it is explicitly declared to be,
1589 and independently of whether its function template
1590 is.
1592 to the primary function; now copy the inline bits to
1593 the various clones. */
1595 {
1602 }
1606 }
1607 }
1609 {
1611 /* Dup decl failed, but this is a new definition. Set the
1612 line number so any errors match this new
1613 definition. */
1617 }
1618 }
1622 /* A specialization must be declared in the same namespace as the
1623 template it is specializing. */
1629 {
1638 /* If TMPL is a forward declaration of a template function, keep a list
1639 of all specializations in case we need to reassign them to a friend
1640 template later in tsubst_friend_function.
1642 Also keep a list of all variable template instantiations so that
1643 process_partial_specialization can check whether a later partial
1644 specialization would have used it. */
1647 }
1650 }
1652 /* Returns true iff two spec_entry nodes are equivalent. */
1656 bool
1658 {
1665 /* tmpl could be a FIELD_DECL for a capture pack. */
1669 {
1670 /* Partial specializations of a variable template can be distinguished by
1671 constraints. */
1675 }
1679 }
1681 /* Returns a hash for a template TMPL and template arguments ARGS. */
1683 static hashval_t
1685 {
1688 }
1690 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1691 ignoring SPEC. */
1693 hashval_t
1695 {
1697 }
1699 /* Recursively calculate a hash value for a template argument ARG, for use
1700 in the hash tables of template specializations. */
1702 hashval_t
1704 {
1716 /* We can get one of these when re-hashing a previous entry in the middle
1717 of substituting into a pack expansion. Just look through it. */
1726 {
1734 {
1739 }
1761 {
1765 {
1768 }
1770 }
1774 {
1777 }
1788 val = iterative_hash_template_arg
1800 val);
1802 val);
1811 /* A lambda can't appear in a template arg, but don't crash on
1812 erroneous input. */
1824 /* Now hash operands as usual. */
1829 }
1832 {
1835 {
1836 // We want an alias specialization that survived strip_typedefs
1837 // to hash differently from its TYPE_CANONICAL, to avoid hash
1838 // collisions that compare as different in template_args_equal.
1839 // These could be dependent specializations that strip_typedefs
1840 // left alone, or untouched specializations because
1841 // coerce_template_parms returns the unconverted template
1842 // arguments if it sees incomplete argument packs.
1845 }
1848 val);
1851 /* Otherwise just compare the types during lookup. */
1860 {
1865 }
1866 }
1869 }
1871 /* Unregister the specialization SPEC as a specialization of TMPL.
1872 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1873 if the SPEC was listed as a specialization of TMPL.
1875 Note that SPEC has been ggc_freed, so we can't look inside it. */
1877 bool
1879 {
1881 spec_entry elt;
1889 {
1894 }
1897 }
1899 /* Like register_specialization, but for local declarations. We are
1900 registering SPEC, an instantiation of TMPL. */
1902 void
1904 {
1906 }
1908 /* TYPE is a class type. Returns true if TYPE is an explicitly
1909 specialized class. */
1911 bool
1913 {
1917 }
1919 /* Print the list of functions at FNS, going through all the overloads
1920 for each element of the list. Alternatively, FNS can not be a
1921 TREE_LIST, in which case it will be printed together with all the
1922 overloads.
1924 MORE and *STR should respectively be FALSE and NULL when the function
1925 is called from the outside. They are used internally on recursive
1926 calls. print_candidates manages the two parameters and leaves NULL
1927 in *STR when it ends. */
1929 static void
1931 {
1937 {
1941 }
1942 else
1943 {
1946 {
1947 /* Pick the prefix string. */
1949 {
1953 }
1957 }
1960 }
1963 {
1966 }
1967 }
1969 /* Print the list of candidate FNS in an error message. FNS can also
1970 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1972 void
1974 {
1978 }
1980 /* Get a (possibly) constrained template declaration for the
1981 purpose of ordering candidates. */
1982 static tree
1984 {
1990 }
1992 /* Among candidates having the same signature, return the
1993 most constrained or NULL_TREE if there is no best candidate.
1994 If the signatures of candidates vary (e.g., template
1995 specialization vs. member function), then there can be no
1996 most constrained.
1998 Note that we don't compare constraints on the functions
1999 themselves, but rather those of their templates. */
2000 static tree
2002 {
2003 // Try to find the best candidate in a first pass.
2006 {
2013 }
2015 // Verify that the champ is better than previous candidates.
2020 }
2023 }
2026 /* Returns the template (one of the functions given by TEMPLATE_ID)
2027 which can be specialized to match the indicated DECL with the
2028 explicit template args given in TEMPLATE_ID. The DECL may be
2029 NULL_TREE if none is available. In that case, the functions in
2030 TEMPLATE_ID are non-members.
2032 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2033 specialization of a member template.
2035 The TEMPLATE_COUNT is the number of references to qualifying
2036 template classes that appeared in the name of the function. See
2037 check_explicit_specialization for a more accurate description.
2039 TSK indicates what kind of template declaration (if any) is being
2040 declared. TSK_TEMPLATE indicates that the declaration given by
2041 DECL, though a FUNCTION_DECL, has template parameters, and is
2042 therefore a template function.
2044 The template args (those explicitly specified and those deduced)
2045 are output in a newly created vector *TARGS_OUT.
2047 If it is impossible to determine the result, an error message is
2048 issued. The error_mark_node is returned to indicate failure. */
2050 static tree
2052 tree decl,
2056 tmpl_spec_kind tsk)
2057 {
2058 tree fns;
2059 tree targs;
2060 tree explicit_targs;
2063 /* A TREE_LIST of templates of which DECL may be a specialization.
2064 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2065 corresponding TREE_PURPOSE is the set of template arguments that,
2066 when used to instantiate the template, would produce a function
2067 with the signature of DECL. */
2077 /* We shouldn't be specializing a member template of an
2078 unspecialized class template; we already gave an error in
2079 check_specialization_scope, now avoid crashing. */
2082 {
2085 }
2093 /* Check for baselinks. */
2098 {
2101 }
2103 {
2106 }
2108 /* Count the number of template headers specified for this
2109 specialization. */
2119 {
2122 tf_warning_or_error,
2126 }
2128 {
2132 {
2133 tree decl_arg_types;
2134 tree fn_arg_types;
2135 tree insttype;
2137 /* In case of explicit specialization, we need to check if
2138 the number of template headers appearing in the specialization
2139 is correct. This is usually done in check_explicit_specialization,
2140 but the check done there cannot be exhaustive when specializing
2141 member functions. Consider the following code:
2143 template <> void A<int>::f(int);
2144 template <> template <> void A<int>::f(int);
2146 Assuming that A<int> is not itself an explicit specialization
2147 already, the first line specializes "f" which is a non-template
2148 member function, whilst the second line specializes "f" which
2149 is a template member function. So both lines are syntactically
2150 correct, and check_explicit_specialization does not reject
2151 them.
2153 Here, we can do better, as we are matching the specialization
2154 against the declarations. We count the number of template
2155 headers, and we check if they match TEMPLATE_COUNT + 1
2156 (TEMPLATE_COUNT is the number of qualifying template classes,
2157 plus there must be another header for the member template
2158 itself).
2160 Notice that if header_count is zero, this is not a
2161 specialization but rather a template instantiation, so there
2162 is no check we can perform here. */
2166 /* Check that the number of template arguments at the
2167 innermost level for DECL is the same as for FN. */
2175 /* DECL might be a specialization of FN. */
2179 /* For a non-static member function, we need to make sure
2180 that the const qualification is the same. Since
2181 get_bindings does not try to merge the "this" parameter,
2182 we must do the comparison explicitly. */
2188 /* Skip the "this" parameter and, for constructors of
2189 classes with virtual bases, the VTT parameter. A
2190 full specialization of a constructor will have a VTT
2191 parameter, but a template never will. */
2192 decl_arg_types
2194 fn_arg_types
2197 /* Function templates cannot be specializations; there are
2198 no partial specializations of functions. Therefore, if
2199 the type of DECL does not match FN, there is no
2200 match.
2202 Note that it should never be the case that we have both
2203 candidates added here, and for regular member functions
2204 below. */
2206 {
2210 }
2212 /* See whether this function might be a specialization of this
2213 template. Suppress access control because we might be trying
2214 to make this specialization a friend, and we have already done
2215 access control for the declaration of the specialization. */
2221 /* We cannot deduce template arguments that when used to
2222 specialize TMPL will produce DECL. */
2225 /* Remove, from the set of candidates, all those functions
2226 whose constraints are not satisfied. */
2230 // Then, try to form the new function type.
2234 fn_arg_types
2239 /* Save this template, and the arguments deduced. */
2241 }
2243 /* FN is an ordinary member function, and we need a
2244 specialization of a member template. */
2245 ;
2247 /* We can get IDENTIFIER_NODEs here in certain erroneous
2248 cases. */
2249 ;
2251 /* This is just an ordinary non-member function. Nothing can
2252 be a specialization of that. */
2253 ;
2255 /* Cannot specialize functions that are created implicitly. */
2256 ;
2257 else
2258 {
2259 tree decl_arg_types;
2261 /* This is an ordinary member function. However, since
2262 we're here, we can assume its enclosing class is a
2263 template class. For example,
2265 template <typename T> struct S { void f(); };
2266 template <> void S<int>::f() {}
2268 Here, S<int>::f is a non-template, but S<int> is a
2269 template class. If FN has the same type as DECL, we
2270 might be in business. */
2273 /* Its enclosing class is an explicit specialization
2274 of a template class. This is not a candidate. */
2279 /* The return types differ. */
2282 /* Adjust the type of DECL in case FN is a static member. */
2289 decl_arg_types))
2292 // If the deduced arguments do not satisfy the constraints,
2293 // this is not a candidate.
2297 // Add the candidate.
2299 }
2300 }
2303 {
2304 /* We have:
2306 [temp.expl.spec]
2308 It is possible for a specialization with a given function
2309 signature to be instantiated from more than one function
2310 template. In such cases, explicit specification of the
2311 template arguments must be used to uniquely identify the
2312 function template specialization being specialized.
2314 Note that here, there's no suggestion that we're supposed to
2315 determine which of the candidate templates is most
2316 specialized. However, we, also have:
2318 [temp.func.order]
2320 Partial ordering of overloaded function template
2321 declarations is used in the following contexts to select
2322 the function template to which a function template
2323 specialization refers:
2325 -- when an explicit specialization refers to a function
2326 template.
2328 So, we do use the partial ordering rules, at least for now.
2329 This extension can only serve to make invalid programs valid,
2330 so it's safe. And, there is strong anecdotal evidence that
2331 the committee intended the partial ordering rules to apply;
2332 the EDG front end has that behavior, and John Spicer claims
2333 that the committee simply forgot to delete the wording in
2334 [temp.expl.spec]. */
2337 {
2340 }
2341 }
2343 // Concepts allows multiple declarations of member functions
2344 // with the same signature. Like above, we need to rely on
2345 // on the partial ordering of those candidates to determine which
2346 // is the best.
2348 {
2350 {
2353 }
2354 }
2357 {
2364 else
2367 }
2371 {
2377 }
2379 /* We have one, and exactly one, match. */
2381 {
2385 // Propagate the candidate's constraints to the declaration.
2388 /* DECL is a re-declaration or partial instantiation of a template
2389 function. */
2392 /* It was a specialization of an ordinary member function in a
2393 template class. */
2395 }
2397 /* It was a specialization of a template. */
2400 {
2405 }
2406 else
2409 }
2411 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2412 but with the default argument values filled in from those in the
2413 TMPL_TYPES. */
2415 static tree
2417 tree tmpl_types)
2418 {
2419 tree new_spec_types;
2427 /* Substitute into the rest of the list. */
2428 new_spec_types =
2432 /* Add the default argument for this parameter. */
2435 new_spec_types);
2436 }
2438 /* DECL is an explicit specialization. Replicate default arguments
2439 from the template it specializes. (That way, code like:
2441 template <class T> void f(T = 3);
2442 template <> void f(double);
2443 void g () { f (); }
2445 works, as required.) An alternative approach would be to look up
2446 the correct default arguments at the call-site, but this approach
2447 is consistent with how implicit instantiations are handled. */
2449 static void
2451 {
2452 tree tmpl;
2453 tree spec_types;
2454 tree tmpl_types;
2455 tree new_spec_types;
2456 tree old_type;
2457 tree new_type;
2458 tree t;
2463 /* See if there's anything we need to do. */
2476 {
2477 /* Remove the this pointer, but remember the object's type for
2478 CV quals. */
2484 {
2485 /* DECL may contain more parameters than TMPL due to the extra
2486 in-charge parameter in constructors and destructors. */
2489 }
2491 {
2494 }
2495 }
2497 /* Compute the merged default arguments. */
2498 new_spec_types =
2501 /* Compute the new FUNCTION_TYPE. */
2503 {
2507 new_spec_types);
2510 /* Put the in-charge parameter back. */
2513 new_spec_types);
2517 new_spec_types);
2518 }
2519 else
2521 new_spec_types);
2531 }
2533 /* Return the number of template headers we expect to see for a definition
2534 or specialization of CTYPE or one of its non-template members. */
2536 int
2538 {
2542 {
2543 /* You're supposed to have one `template <...>' for every
2544 template class, but you don't need one for a full
2545 specialization. For example:
2547 template <class T> struct S{};
2548 template <> struct S<int> { void f(); };
2549 void S<int>::f () {}
2551 is correct; there shouldn't be a `template <>' for the
2552 definition of `S<int>::f'. */
2554 /* If CTYPE does not have template information of any
2555 kind, then it is not a template, nor is it nested
2556 within a template. */
2564 }
2567 }
2569 /* Do a simple sanity check on the template headers that precede the
2570 variable declaration DECL. */
2572 void
2574 {
2579 {
2582 "variable templates only available with "
2585 // Namespace-scope variable templates should have a template header.
2587 }
2589 {
2596 "members of an explicitly specialized class are defined "
2598 }
2599 }
2601 /* Check to see if the function just declared, as indicated in
2602 DECLARATOR, and in DECL, is a specialization of a function
2603 template. We may also discover that the declaration is an explicit
2604 instantiation at this point.
2606 Returns DECL, or an equivalent declaration that should be used
2607 instead if all goes well. Issues an error message if something is
2608 amiss. Returns error_mark_node if the error is not easily
2609 recoverable.
2611 FLAGS is a bitmask consisting of the following flags:
2613 2: The function has a definition.
2614 4: The function is a friend.
2616 The TEMPLATE_COUNT is the number of references to qualifying
2617 template classes that appeared in the name of the function. For
2618 example, in
2620 template <class T> struct S { void f(); };
2621 void S<int>::f();
2623 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2624 classes are not counted in the TEMPLATE_COUNT, so that in
2626 template <class T> struct S {};
2627 template <> struct S<int> { void f(); }
2628 template <> void S<int>::f();
2630 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2631 invalid; there should be no template <>.)
2633 If the function is a specialization, it is marked as such via
2634 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2635 is set up correctly, and it is added to the list of specializations
2636 for that template. */
2638 tree
2640 tree decl,
2643 {
2652 tmpl_spec_kind tsk;
2655 {
2658 else
2660 }
2661 else
2665 {
2668 {
2671 }
2673 {
2675 /* This could be something like:
2677 template <class T> void f(T);
2678 class S { friend void f<>(int); } */
2680 else
2681 {
2682 /* This case handles bogus declarations like template <>
2683 template <class T> void f<int>(); */
2686 declarator);
2688 }
2689 }
2693 /* The error has already been reported in
2694 check_specialization_scope. */
2700 /* Fall through. */
2713 decl);
2716 else
2720 /* Fall through. */
2726 /* In cases like template<> constexpr bool v = true;
2727 We'll give an error in check_template_variable. */
2733 else
2739 {
2740 /* This case handles bogus declarations like template <>
2741 template <class T> void f<int>(); */
2745 declarator);
2747 {
2748 /* Partial specialization of variable template. */
2752 }
2756 else
2760 ok:;
2761 }
2764 /* This is a specialization of a member template, without
2765 specialization the containing class. Something like:
2767 template <class T> struct S {
2768 template <class U> void f (U);
2769 };
2770 template <> template <class U> void S<int>::f(U) {}
2772 That's a specialization -- but of the entire template. */
2778 }
2781 /* This doesn't apply to variable templates. */
2784 {
2788 {
2792 }
2793 }
2796 {
2801 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2803 {
2804 tree fns;
2809 else
2810 {
2811 /* If there is no class context, the explicit instantiation
2812 must be at namespace scope. */
2815 /* Find the namespace binding, using the declaration
2816 context. */
2820 {
2823 }
2824 else
2825 {
2831 }
2832 }
2835 }
2841 {
2843 /* A specialization in class scope. This is invalid,
2844 but the error will already have been flagged by
2845 check_specialization_scope. */
2847 else
2848 {
2849 /* It's not valid to write an explicit instantiation in
2850 class scope, e.g.:
2852 class C { template void f(); }
2854 This case is caught by the parser. However, on
2855 something like:
2857 template class C { void f(); };
2859 (which is invalid) we can get here. The error will be
2860 issued later. */
2861 ;
2862 }
2865 }
2868 {
2869 // We'll match variable templates in start_decl.
2873 /* Find the list of functions in ctype that have the same
2874 name as the declared function. */
2880 {
2885 {
2886 /* From [temp.expl.spec]:
2888 If such an explicit specialization for the member
2889 of a class template names an implicitly-declared
2890 special member function (clause _special_), the
2891 program is ill-formed.
2893 Similar language is found in [temp.explicit]. */
2896 }
2899 }
2902 {
2906 }
2907 else
2908 {
2910 tree ovl;
2912 /* For a type-conversion operator, we cannot do a
2913 name-based lookup. We might be looking for `operator
2914 int' which will be a specialization of `operator T'.
2915 So, we find *all* the conversion operators, and then
2916 select from them. */
2924 {
2926 /* There are no more conversion functions. */
2929 /* Glue all these conversion functions together
2930 with those we already have. */
2933 }
2934 }
2937 {
2940 }
2941 else
2943 }
2945 /* Figure out what exactly is being specialized at this point.
2946 Note that for an explicit instantiation, even one for a
2947 member function, we cannot tell apriori whether the
2948 instantiation is for a member template, or just a member
2949 function of a template class. Even if a member template is
2950 being instantiated, the member template arguments may be
2951 elided if they can be deduced from the rest of the
2952 declaration. */
2955 member_specialization,
2956 template_count,
2957 tsk);
2960 /* We couldn't figure out what this declaration was
2961 specializing. */
2963 else
2964 {
2968 {
2969 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2970 is done by do_decl_instantiation later. */
2976 {
2977 /* If TMPL is not the most general template (for
2978 example, if TMPL is a friend template that is
2979 injected into namespace scope), then there will
2980 be too many levels of TARGS. Remove some of them
2981 here. */
2983 tree new_targs;
2990 }
2993 }
2995 /* If we thought that the DECL was a member function, but it
2996 turns out to be specializing a static member function,
2997 make DECL a static member function as well. */
3003 /* If this is a specialization of a member template of a
3004 template class, we want to return the TEMPLATE_DECL, not
3005 the specialization of it. */
3007 {
3012 {
3013 tree parm;
3017 /* We want to use the argument list specified in the
3018 definition, not in the original declaration. */
3023 }
3026 }
3028 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3034 /* Inherit default function arguments from the template
3035 DECL is specializing. */
3039 /* This specialization has the same protection as the
3040 template it specializes. */
3044 /* 7.1.1-1 [dcl.stc]
3046 A storage-class-specifier shall not be specified in an
3047 explicit specialization...
3049 The parser rejects these, so unless action is taken here,
3050 explicit function specializations will always appear with
3051 global linkage.
3053 The action recommended by the C++ CWG in response to C++
3054 defect report 605 is to make the storage class and linkage
3055 of the explicit specialization match the templated function:
3057 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3058 */
3060 {
3064 /* A concept cannot be specialized. */
3066 {
3068 gen_tmpl);
3070 }
3072 /* This specialization has the same linkage and visibility as
3073 the function template it specializes. */
3076 {
3079 }
3082 {
3085 }
3086 }
3088 /* If DECL is a friend declaration, declared using an
3089 unqualified name, the namespace associated with DECL may
3090 have been set incorrectly. For example, in:
3092 template <typename T> void f(T);
3093 namespace N {
3094 struct S { friend void f<int>(int); }
3095 }
3097 we will have set the DECL_CONTEXT for the friend
3098 declaration to N, rather than to the global namespace. */
3103 /* This is not really a declaration of a specialization.
3104 It's just the name of an instantiation. But, it's not
3105 a request for an instantiation, either. */
3108 /* A specialization is not necessarily COMDAT. */
3114 /* If this is a full specialization, register it so that we can find
3115 it again. Partial specializations will be registered in
3116 process_partial_specialization. */
3121 /* A 'structor should already have clones. */
3127 }
3128 }
3131 }
3133 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3134 parameters. These are represented in the same format used for
3135 DECL_TEMPLATE_PARMS. */
3137 int
3139 {
3140 const_tree p1;
3141 const_tree p2;
3149 {
3161 {
3165 /* If either of the template parameters are invalid, assume
3166 they match for the sake of error recovery. */
3179 }
3180 }
3183 /* One set of parameters has more parameters lists than the
3184 other. */
3188 }
3190 /* Determine whether PARM is a parameter pack. */
3192 bool
3194 {
3195 /* Determine if we have a non-type template parameter pack. */
3202 /* If this is a list of template parameters, we could get a
3203 TYPE_DECL or a TEMPLATE_DECL. */
3207 /* Otherwise it must be a type template parameter. */
3211 }
3213 /* Determine if T is a function parameter pack. */
3215 bool
3217 {
3221 }
3223 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3224 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3226 tree
3228 {
3235 }
3237 /* Return true iff the function parameter PARAM_DECL was expanded
3238 from the function parameter pack PACK. */
3240 bool
3242 {
3247 /* The parameter pack and its pack arguments have the same
3248 DECL_PARM_INDEX. */
3250 }
3252 /* Determine whether ARGS describes a variadic template args list,
3253 i.e., one that is terminated by a template argument pack. */
3255 static bool
3257 {
3259 tree last_parm;
3273 }
3275 /* Generate a new name for the parameter pack name NAME (an
3276 IDENTIFIER_NODE) that incorporates its */
3278 static tree
3280 {
3281 /* Munge the name to include the parameter index. */
3282 #define NUMBUF_LEN 128
3296 }
3298 /* Return true if T is a primary function, class or alias template
3299 instantiation. */
3301 bool
3303 {
3317 }
3319 /* Return true if PARM is a template template parameter. */
3321 bool
3323 {
3325 }
3327 /* Return true iff PARM is a DECL representing a type template
3328 parameter. */
3330 bool
3332 {
3337 }
3339 /* Return the template parameters of T if T is a
3340 primary template instantiation, NULL otherwise. */
3342 tree
3344 {
3349 parms = INNERMOST_TEMPLATE_PARMS
3353 }
3355 /* Return the template parameters of the LEVELth level from the full list
3356 of template parameters PARMS. */
3358 tree
3360 {
3361 tree p;
3372 }
3374 /* Returns the template arguments of T if T is a template instantiation,
3375 NULL otherwise. */
3377 tree
3379 {
3387 }
3389 /* Return the argument pack elements of T if T is a template argument pack,
3390 NULL otherwise. */
3392 tree
3394 {
3400 }
3402 /* Structure used to track the progress of find_parameter_packs_r. */
3403 struct find_parameter_pack_data
3404 {
3405 /* TREE_LIST that will contain all of the parameter packs found by
3406 the traversal. */
3409 /* Set of AST nodes that have been visited by the traversal. */
3411 };
3413 /* Identifies all of the argument packs that occur in a template
3414 argument and appends them to the TREE_LIST inside DATA, which is a
3415 find_parameter_pack_data structure. This is a subroutine of
3416 make_pack_expansion and uses_parameter_packs. */
3417 static tree
3419 {
3425 /* Handle type aliases/typedefs. */
3427 {
3434 }
3436 /* Identify whether this is a parameter pack or not. */
3438 {
3454 {
3455 /* We don't want to walk into the type of a PARM_DECL,
3456 because we don't want to see the type parameter pack. */
3459 }
3462 /* Look through a lambda capture proxy to the field pack. */
3465 {
3471 }
3473 {
3475 find_parameter_packs_r,
3478 }
3485 /* Not a parameter pack. */
3487 }
3490 {
3491 /* Add this parameter pack to the list. */
3493 }
3499 /* This switch statement will return immediately if we don't find a
3500 parameter pack. */
3502 {
3507 /* Check the template itself. */
3510 /* Check the template arguments. */
3526 /* Fall through. */
3568 }
3571 }
3573 /* Determines if the expression or type T uses any parameter packs. */
3574 bool
3576 {
3584 }
3586 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3587 representation a base-class initializer into a parameter pack
3588 expansion. If all goes well, the resulting node will be an
3589 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3590 respectively. */
3591 tree
3593 {
3594 tree result;
3603 {
3604 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3605 class initializer. In this case, the TREE_PURPOSE will be a
3606 _TYPE node (representing the base class expansion we're
3607 initializing) and the TREE_VALUE will be a TREE_LIST
3608 containing the initialization arguments.
3610 The resulting expansion looks somewhat different from most
3611 expansions. Rather than returning just one _EXPANSION, we
3612 return a TREE_LIST whose TREE_PURPOSE is a
3613 TYPE_PACK_EXPANSION containing the bases that will be
3614 initialized. The TREE_VALUE will be identical to the
3615 original TREE_VALUE, which is a list of arguments that will
3616 be passed to each base. We do not introduce any new pack
3617 expansion nodes into the TREE_VALUE (although it is possible
3618 that some already exist), because the TREE_PURPOSE and
3619 TREE_VALUE all need to be expanded together with the same
3620 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3621 resulting TREE_PURPOSE will mention the parameter packs in
3622 both the bases and the arguments to the bases. */
3623 tree purpose;
3624 tree value;
3627 /* Determine which parameter packs will be used by the base
3628 class expansion. */
3635 {
3639 }
3642 {
3643 /* Collect the sets of parameter packs used in each of the
3644 initialization arguments. */
3646 {
3647 /* Determine which parameter packs will be expanded in this
3648 argument. */
3651 }
3652 }
3656 /* Create the pack expansion type for the base type. */
3661 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3662 they will rarely be compared to anything. */
3666 }
3671 /* Build the PACK_EXPANSION_* node. */
3672 result = for_types
3677 {
3678 /* Propagate type and const-expression information. */
3681 }
3682 else
3683 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3684 they will rarely be compared to anything. */
3687 /* Determine which parameter packs will be expanded. */
3693 /* Make sure we found some parameter packs. */
3695 {
3698 else
3701 }
3707 }
3709 /* Checks T for any "bare" parameter packs, which have not yet been
3710 expanded, and issues an error if any are found. This operation can
3711 only be done on full expressions or types (e.g., an expression
3712 statement, "if" condition, etc.), because we could have expressions like:
3714 foo(f(g(h(args)))...)
3716 where "args" is a parameter pack. check_for_bare_parameter_packs
3717 should not be called for the subexpressions args, h(args),
3718 g(h(args)), or f(g(h(args))), because we would produce erroneous
3719 error messages.
3721 Returns TRUE and emits an error if there were bare parameter packs,
3722 returns FALSE otherwise. */
3723 bool
3725 {
3741 {
3744 {
3753 else
3758 else
3762 }
3765 }
3768 }
3770 /* Expand any parameter packs that occur in the template arguments in
3771 ARGS. */
3772 tree
3774 {
3780 /* First, determine if we need to expand anything, and the number of
3781 slots we'll need. */
3783 {
3788 {
3792 else
3794 }
3795 else
3796 {
3798 num_result_args++;
3799 }
3800 }
3802 /* If no expansion is necessary, we're done. */
3806 /* Expand arguments. */
3809 non_default_args_count =
3812 {
3815 {
3822 }
3823 else
3824 {
3827 }
3828 }
3832 }
3834 /* Checks if DECL shadows a template parameter.
3836 [temp.local]: A template-parameter shall not be redeclared within its
3837 scope (including nested scopes).
3839 Emits an error and returns TRUE if the DECL shadows a parameter,
3840 returns FALSE otherwise. */
3842 bool
3844 {
3845 tree olddecl;
3847 /* If we're not in a template, we can't possibly shadow a template
3848 parameter. */
3852 /* Figure out what we're shadowing. */
3857 /* If there's no previous binding for this name, we're not shadowing
3858 anything, let alone a template parameter. */
3862 /* If we're not shadowing a template parameter, we're done. Note
3863 that OLDDECL might be an OVERLOAD (or perhaps even an
3864 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3865 node. */
3869 /* We check for decl != olddecl to avoid bogus errors for using a
3870 name inside a class. We check TPFI to avoid duplicate errors for
3871 inline member templates. */
3877 /* Don't complain about the injected class name, as we've already
3878 complained about the class itself. */
3885 else
3890 }
3892 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3893 ORIG_LEVEL, DECL, and TYPE. */
3895 static tree
3899 tree decl,
3900 tree type)
3901 {
3912 }
3914 /* Find the canonical type parameter for the given template type
3915 parameter. Returns the canonical type parameter, which may be TYPE
3916 if no such parameter existed. */
3918 static tree
3920 {
3921 tree list;
3935 else
3936 {
3941 }
3942 }
3944 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3945 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3946 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3947 new one is created. */
3949 static tree
3951 tsubst_flags_t complain)
3952 {
3957 {
3976 /* Template template parameters need this. */
3978 {
3985 }
3986 }
3989 }
3991 /* Process information from new template parameter PARM and append it
3992 to the LIST being built. This new parameter is a non-type
3993 parameter iff IS_NON_TYPE is true. This new parameter is a
3994 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3995 is in PARM_LOC. */
3997 tree
4000 {
4009 {
4013 {
4017 else
4019 }
4022 }
4025 {
4031 {
4032 /* [temp.param]
4034 The top-level cv-qualifiers on the template-parameter are
4035 ignored when determining its type. */
4040 && !is_parameter_pack
4041 /* If we're in a nested template parameter list, the template
4042 template parameter could be a parameter pack. */
4044 {
4045 /* This template parameter is not a parameter pack, but it
4046 should be. Complain about "bare" parameter packs. */
4049 /* Recover by calling this a parameter pack. */
4051 }
4052 }
4054 /* A template parameter is not modifiable. */
4063 processing_template_decl,
4068 }
4069 else
4070 {
4071 tree t;
4075 {
4077 /* This is for distinguishing between real templates and template
4078 template parameters */
4082 }
4083 else
4084 {
4086 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4089 }
4096 processing_template_decl,
4100 }
4104 /* Build requirements for the type/template parameter.
4105 This must be done after SET_DECL_TEMPLATE_PARM_P or
4106 process_template_parm could fail. */
4111 /* Build the parameter node linking the parameter declaration,
4112 its default argument (if any), and its constraints (if any). */
4117 }
4119 /* The end of a template parameter list has been reached. Process the
4120 tree list into a parameter vector, converting each parameter into a more
4121 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4122 as PARM_DECLs. */
4124 tree
4126 {
4131 /* Pop the dummy parameter level and add the real one. */
4134 current_template_parms
4139 {
4143 }
4148 }
4150 // Explicitly indicate the end of the template parameter list. We assume
4151 // that the current template parameters have been constructed and/or
4152 // managed explicitly, as when creating new template template parameters
4153 // from a shorthand constraint.
4154 void
4156 {
4158 }
4160 /* end_template_decl is called after a template declaration is seen. */
4162 void
4164 {
4170 /* This matches the pushlevel in begin_template_parm_list. */
4175 }
4177 /* Takes a TREE_LIST representing a template parameter and convert it
4178 into an argument suitable to be passed to the type substitution
4179 functions. Note that If the TREE_LIST contains an error_mark
4180 node, the returned argument is error_mark_node. */
4182 tree
4184 {
4197 {
4201 {
4202 /* Turn this argument into a TYPE_ARGUMENT_PACK
4203 with a single element, which expands T. */
4205 #ifdef ENABLE_CHECKING
4206 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4208 #endif
4213 }
4214 }
4215 else
4216 {
4220 {
4221 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4222 with a single element, which expands T. */
4225 #ifdef ENABLE_CHECKING
4226 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4228 #endif
4235 }
4236 else
4238 }
4240 }
4242 /* Given a set of template parameters, return them as a set of template
4243 arguments. The template parameters are represented as a TREE_VEC, in
4244 the form documented in cp-tree.h for template arguments. */
4246 static tree
4248 {
4249 tree header;
4254 /* If there is only one level of template parameters, we do not
4255 create a TREE_VEC of TREE_VECs. Instead, we return a single
4256 TREE_VEC containing the arguments. */
4261 {
4269 #ifdef ENABLE_CHECKING
4271 #endif
4275 else
4277 }
4280 }
4282 /* Within the declaration of a template, return the currently active
4283 template parameters as an argument TREE_VEC. */
4285 static tree
4287 {
4289 }
4291 /* Update the declared TYPE by doing any lookups which were thought to be
4292 dependent, but are not now that we know the SCOPE of the declarator. */
4294 tree
4296 {
4307 /* Don't bother building up the args in this case. */
4309 {
4310 /* tsubst in the args corresponding to the template parameters,
4311 including auto if present. Most things will be unchanged, but
4312 make_typename_type and tsubst_qualified_id will resolve
4313 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4316 tree pushed;
4318 {
4322 }
4327 }
4333 {
4336 else
4338 }
4340 }
4342 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4343 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4344 the new template is a member template. */
4346 tree
4348 {
4356 }
4358 struct template_parm_data
4359 {
4360 /* The level of the template parameters we are currently
4361 processing. */
4364 /* The index of the specialization argument we are currently
4365 processing. */
4368 /* An array whose size is the number of template parameters. The
4369 elements are nonzero if the parameter has been used in any one
4370 of the arguments processed so far. */
4373 /* An array whose size is the number of template arguments. The
4374 elements are nonzero if the argument makes use of template
4375 parameters of this level. */
4377 };
4379 /* Subroutine of push_template_decl used to see if each template
4380 parameter in a partial specialization is used in the explicit
4381 argument list. If T is of the LEVEL given in DATA (which is
4382 treated as a template_parm_data*), then DATA->PARMS is marked
4383 appropriately. */
4385 static int
4387 {
4395 {
4398 }
4400 /* Return zero so that for_each_template_parm will continue the
4401 traversal of the tree; we want to mark *every* template parm. */
4403 }
4405 /* Process the partial specialization DECL. */
4407 static tree
4409 {
4416 tree inner_parms;
4417 tree inst;
4427 /* A concept cannot be specialized. */
4429 {
4432 }
4437 /* We check that each of the template parameters given in the
4438 partial specialization is used in the argument list to the
4439 specialization. For example:
4441 template <class T> struct S;
4442 template <class T> struct S<T*>;
4444 The second declaration is OK because `T*' uses the template
4445 parameter T, whereas
4447 template <class T> struct S<int>;
4449 is no good. Even trickier is:
4451 template <class T>
4452 struct S1
4453 {
4454 template <class U>
4455 struct S2;
4456 template <class U>
4457 struct S2<T>;
4458 };
4460 The S2<T> declaration is actually invalid; it is a
4461 full-specialization. Of course,
4463 template <class U>
4464 struct S2<T (*)(U)>;
4466 or some such would have been OK. */
4474 {
4479 NULL,
4481 }
4484 {
4485 /* One of the template parms was not used in a deduced context in the
4486 specialization. */
4488 {
4492 }
4496 }
4501 /* [temp.class.spec]
4503 The argument list of the specialization shall not be identical to
4504 the implicit argument list of the primary template. */
4505 tree main_args
4508 && (!flag_concepts
4511 {
4515 else
4519 }
4521 /* A partial specialization that replaces multiple parameters of the
4522 primary template with a pack expansion is less specialized for those
4523 parameters. */
4525 {
4527 "primary template because it replaces multiple parameters "
4531 }
4533 /* [temp.class.spec]
4535 A partially specialized non-type argument expression shall not
4536 involve template parameters of the partial specialization except
4537 when the argument expression is a simple identifier.
4539 The type of a template parameter corresponding to a specialized
4540 non-type argument shall not be dependent on a parameter of the
4541 specialization.
4543 Also, we verify that pack expansions only occur at the
4544 end of the argument list. */
4548 {
4555 {
4556 /* Extract the arguments from the argument pack. We'll be
4557 iterating over these in the following loop. */
4560 }
4563 {
4565 /* Get the Jth argument in the parameter pack. */
4569 {
4570 /* Pack expansions must come at the end of the
4571 argument list. */
4574 {
4578 else
4581 }
4582 }
4585 /* We only care about the pattern. */
4591 /* This next two lines are the `argument expression is not just a
4592 simple identifier' condition and also the `specialized
4593 non-type argument' bit. */
4597 {
4601 arg);
4602 else
4603 {
4604 /* Look at the corresponding template parameter,
4605 marking which template parameters its type depends
4606 upon. */
4610 {
4611 /* We haven't yet initialized TPD2. Do so now. */
4613 /* The number of parameters here is the number in the
4614 main template, which, as checked in the assertion
4615 above, is NARGS. */
4619 }
4621 /* Mark the template parameters. But this time, we're
4622 looking for the template parameters of the main
4623 template, not in the specialization. */
4630 NULL,
4634 {
4635 /* The type depended on some template parameters.
4636 If they are fully specialized in the
4637 specialization, that's OK. */
4646 "type %qT of template argument %qE depends "
4648 "type %qT of template argument %qE depends "
4650 type,
4651 arg);
4652 }
4653 }
4654 }
4655 }
4656 }
4658 /* We should only get here once. */
4662 // Build the template decl.
4672 /* We didn't register this in check_explicit_specialization so we could
4673 wait until the constraints were set. */
4675 else
4685 {
4691 {
4694 {
4698 "partial specialization of %qD after instantiation "
4700 }
4701 }
4702 }
4705 }
4707 /* PARM is a template parameter of some form; return the corresponding
4708 TEMPLATE_PARM_INDEX. */
4710 static tree
4712 {
4725 }
4727 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4728 parameter packs used by the template parameter PARM. */
4730 static void
4732 {
4733 /* A type parm can't refer to another parm. */
4737 {
4741 }
4748 }
4750 /* PARM is a template parameter pack. Return any parameter packs used in
4751 its type or the type of any of its template parameters. If there are
4752 any such packs, it will be instantiated into a fixed template parameter
4753 list by partial instantiation rather than be fully deduced. */
4755 tree
4757 {
4758 /* This can only be true in a member template. */
4761 /* This can only be true for a parameter pack. */
4764 /* A type parm can't refer to another parm. */
4777 }
4779 /* Check that a template declaration's use of default arguments and
4780 parameter packs is not invalid. Here, PARMS are the template
4781 parameters. IS_PRIMARY is true if DECL is the thing declared by
4782 a primary template. IS_PARTIAL is true if DECL is a partial
4783 specialization.
4785 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4786 declaration (but not a definition); 1 indicates a declaration, 2
4787 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4788 emitted for extraneous default arguments.
4790 Returns TRUE if there were no errors found, FALSE otherwise. */
4792 bool
4795 {
4798 tree parm_level;
4801 /* [temp.param]
4803 A default template-argument shall not be specified in a
4804 function template declaration or a function template definition, nor
4805 in the template-parameter-list of the definition of a member of a
4806 class template. */
4810 /* You can't have a function template declaration in a local
4811 scope, nor you can you define a member of a class template in a
4812 local scope. */
4820 /* A lambda doesn't have an explicit declaration; don't complain
4821 about the parms of the enclosing class. */
4828 /* If this is either a friend defined in the scope of the class
4829 or a member function. */
4835 /* And, if it was a member function, it really was defined in
4836 the scope of the class. */
4839 /* We already checked these parameters when the template was
4840 declared, so there's no need to do it again now. This function
4841 was defined in class scope, but we're processing its body now
4842 that the class is complete. */
4845 /* Core issue 226 (C++0x only): the following only applies to class
4846 templates. */
4849 {
4850 /* [temp.param]
4852 If a template-parameter has a default template-argument, all
4853 subsequent template-parameters shall have a default
4854 template-argument supplied. */
4856 {
4863 {
4873 {
4875 /* For better subsequent error-recovery, we indicate that
4876 there should have been a default argument. */
4879 }
4881 && !is_friend_decl
4882 /* Don't complain about an enclosing partial
4883 specialization. */
4888 /* A fixed parameter pack will be partially
4889 instantiated into a fixed length list. */
4891 {
4892 /* A primary class template can only have one
4893 parameter pack, at the end of the template
4894 parameter list. */
4902 }
4903 }
4904 }
4905 }
4908 || is_partial
4909 || !is_primary
4911 /* For an ordinary class template, default template arguments are
4912 allowed at the innermost level, e.g.:
4913 template <class T = int>
4914 struct S {};
4915 but, in a partial specialization, they're not allowed even
4916 there, as we have in [temp.class.spec]:
4918 The template parameter list of a specialization shall not
4919 contain default template argument values.
4921 So, for a partial specialization, or for a function template
4922 (in C++98/C++03), we look at all of them. */
4923 ;
4924 else
4925 /* But, for a primary class template that is not a partial
4926 specialization we look at all template parameters except the
4927 innermost ones. */
4930 /* Figure out what error message to issue. */
4943 else
4947 /* If we're inside a class definition, there's no need to
4948 examine the parameters to the class itself. On the one
4949 hand, they will be checked when the class is defined, and,
4950 on the other, default arguments are valid in things like:
4951 template <class T = double>
4952 struct S { template <class U> void f(U); };
4953 Here the default argument for `S' has no bearing on the
4954 declaration of `f'. */
4956 else
4957 /* Check everything. */
4963 {
4970 {
4975 {
4977 {
4984 }
4986 /* Clear out the default argument so that we are not
4987 confused later. */
4989 }
4990 }
4992 /* At this point, if we're still interested in issuing messages,
4993 they must apply to classes surrounding the object declared. */
4997 }
5000 }
5002 /* Worker for push_template_decl_real, called via
5003 for_each_template_parm. DATA is really an int, indicating the
5004 level of the parameters we are interested in. If T is a template
5005 parameter of that level, return nonzero. */
5007 static int
5009 {
5015 else
5018 }
5020 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5021 parameters given by current_template_args, or reuses a
5022 previously existing one, if appropriate. Returns the DECL, or an
5023 equivalent one, if it is replaced via a call to duplicate_decls.
5025 If IS_FRIEND is true, DECL is a friend declaration. */
5027 tree
5029 {
5030 tree tmpl;
5031 tree args;
5032 tree info;
5033 tree ctx;
5037 /* True if the template is a member template, in the sense of
5038 [temp.mem]. */
5044 /* See if this is a partial specialization. */
5057 /* For a friend, we want the context of the friend function, not
5058 the type of which it is a friend. */
5062 /* In the case of a virtual function, we want the class in which
5063 it is defined. */
5065 else
5066 /* Otherwise, if we're currently defining some class, the DECL
5067 is assumed to be a member of the class. */
5076 /* See if this is a primary template. */
5079 /* A friend template that specifies a class context, i.e.
5080 template <typename T> friend void A<T>::f();
5081 is not primary. */
5086 else
5090 {
5097 {
5100 }
5102 {
5104 {
5107 }
5109 {
5110 /* [temp.mem]
5112 A destructor shall not be a member template. */
5115 }
5122 {
5123 /* [basic.stc.dynamic.allocation]
5125 An allocation function can be a function
5126 template. ... Template allocation functions shall
5127 have two or more parameters. */
5130 }
5131 }
5137 /* alias-declaration */
5141 else
5142 {
5145 }
5146 }
5148 /* Check to see that the rules regarding the use of default
5149 arguments are not being violated. */
5153 /* Ensure that there are no parameter packs in the type of this
5154 declaration that have not been expanded. */
5156 {
5157 /* Check each of the arguments individually to see if there are
5158 any bare parameter packs. */
5164 {
5167 {
5168 /* This is a PARM_DECL that contains unexpanded parameter
5169 packs. We have already complained about this in the
5170 check_for_bare_parameter_packs call, so just replace
5171 these types with ERROR_MARK_NODE. */
5174 }
5178 }
5180 /* Check for bare parameter packs in the return type and the
5181 exception specifiers. */
5183 /* Errors were already issued, set return type to int
5184 as the frontend doesn't expect error_mark_node as
5185 the return type. */
5189 }
5194 {
5197 }
5210 {
5215 /* If DECL is a TYPE_DECL for a class-template, then there won't
5216 be DECL_LANG_SPECIFIC. The information equivalent to
5217 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5221 {
5222 /* Since a template declaration already existed for this
5223 class-type, we must be redeclaring it here. Make sure
5224 that the redeclaration is valid. */
5226 current_template_parms,
5228 /* We don't need to create a new TEMPLATE_DECL; just use the
5229 one we already had. */
5231 }
5232 else
5233 {
5235 member_template_p);
5240 {
5241 /* A specialization of a member template of a template
5242 class. */
5246 }
5247 }
5248 }
5249 else
5250 {
5256 {
5259 }
5267 {
5268 tree new_tmpl;
5270 /* The declaration is a specialization of a member
5271 template, declared outside the class. Therefore, the
5272 innermost template arguments will be NULL, so we
5273 replace them with the arguments determined by the
5274 earlier call to check_explicit_specialization. */
5277 new_tmpl
5279 member_template_p);
5289 args,
5292 }
5294 /* Make sure the template headers we got make sense. */
5299 {
5304 }
5305 else
5307 {
5312 {
5316 else
5320 /* Avoid crash in import_export_decl. */
5323 }
5328 /* Can happen in erroneous input. */
5330 else
5332 }
5334 /* Check that the parms are used in the appropriate qualifying scopes
5335 in the declarator. */
5339 {
5345 /* Avoid crash in import_export_decl. */
5348 }
5349 }
5354 /* Push template declarations for global functions and types. Note
5355 that we do not try to push a global template friend declared in a
5356 template class; such a thing may well depend on the template
5357 parameters of the class. */
5360 {
5365 /* Hide template friend classes that haven't been declared yet. */
5367 {
5370 }
5371 }
5374 {
5380 {
5383 /* It is a conversion operator. See if the type converted to
5384 depends on innermost template operands. */
5387 depth))
5389 }
5391 /* Give template template parms a DECL_CONTEXT of the template
5392 for which they are a parameter. */
5395 {
5399 }
5405 }
5407 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5408 back to its most general template. If TMPL is a specialization,
5409 ARGS may only have the innermost set of arguments. Add the missing
5410 argument levels if necessary. */
5418 else
5419 {
5424 }
5427 && !is_friend
5430 /* Set DECL_COMDAT on template instantiations; if we force
5431 them to be emitted by explicit instantiation or -frepo,
5432 mark_needed will tell cgraph to do the right thing. */
5436 }
5438 tree
5440 {
5442 }
5444 /* FN is an inheriting constructor that inherits from the constructor
5445 template INHERITED; turn FN into a constructor template with a matching
5446 template header. */
5448 tree
5450 {
5451 tree inner_parms
5454 tree parms
5465 }
5467 /* Called when a class template TYPE is redeclared with the indicated
5468 template PARMS, e.g.:
5470 template <class T> struct S;
5471 template <class T> struct S {}; */
5473 bool
5475 {
5476 tree tmpl;
5477 tree tmpl_parms;
5481 {
5484 }
5488 /* The type is nested in some template class. Nothing to worry
5489 about here; there are no new template parameters for the nested
5490 type. */
5494 {
5496 tmpl);
5498 }
5504 {
5514 }
5517 {
5518 tree tmpl_parm;
5519 tree parm;
5520 tree tmpl_default;
5521 tree parm_default;
5535 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5536 TEMPLATE_DECL. */
5546 {
5550 }
5553 {
5554 /* We have in [temp.param]:
5556 A template-parameter may not be given default arguments
5557 by two different declarations in the same scope. */
5562 }
5565 /* Update the previous template parameters (which are the ones
5566 that will really count) with the new default value. */
5569 /* Update the new parameters, too; they'll be used as the
5570 parameters for any members. */
5573 /* Give each template template parm in this redeclaration a
5574 DECL_CONTEXT of the template for which they are a parameter. */
5576 {
5579 }
5580 }
5582 // Cannot redeclare a class template with a different set of constraints.
5584 {
5589 }
5592 }
5594 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5595 to be used when the caller has already checked
5596 (processing_template_decl
5597 && !instantiation_dependent_expression_p (expr)
5598 && potential_constant_expression (expr))
5599 and cleared processing_template_decl. */
5601 tree
5603 {
5606 complain,
5610 }
5612 /* Simplify EXPR if it is a non-dependent expression. Returns the
5613 (possibly simplified) expression. */
5615 tree
5617 {
5621 /* If we're in a template, but EXPR isn't value dependent, simplify
5622 it. We're supposed to treat:
5624 template <typename T> void f(T[1 + 1]);
5625 template <typename T> void f(T[2]);
5627 as two declarations of the same function, for example. */
5631 {
5632 processing_template_decl_sentinel s;
5634 }
5636 }
5638 tree
5640 {
5642 }
5644 /* True iff T is a specialization of a variable template. */
5646 bool
5648 {
5653 }
5655 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5656 template declaration, or a TYPE_DECL for an alias declaration. */
5658 bool
5660 {
5668 }
5670 /* Return TRUE iff T is a specialization of an alias template. */
5672 bool
5674 {
5675 /* It's an alias template specialization if it's an alias and its
5676 TYPE_NAME is a specialization of a primary template. */
5678 {
5682 {
5685 }
5686 }
5688 }
5690 /* An alias template is complex from a SFINAE perspective if a template-id
5691 using that alias can be ill-formed when the expansion is not, as with
5692 the void_t template. We determine this by checking whether the
5693 expansion for the alias template uses all its template parameters. */
5695 struct uses_all_template_parms_data
5696 {
5699 };
5701 static int
5703 {
5711 }
5713 static bool
5715 {
5730 }
5732 /* Return TRUE iff T is a specialization of a complex alias template with
5733 dependent template-arguments. */
5735 bool
5737 {
5740 && (any_dependent_template_arguments_p
5742 }
5744 /* Return the number of innermost template parameters in TMPL. */
5746 static int
5748 {
5751 }
5753 /* Return either TMPL or another template that it is equivalent to under DR
5754 1286: An alias that just changes the name of a template is equivalent to
5755 the other template. */
5757 static tree
5759 {
5762 {
5765 {
5770 {
5771 tree alias_args = INNERMOST_TEMPLATE_ARGS
5775 /* The alias type is equivalent to the pattern of the
5776 underlying template, so strip the alias. */
5779 }
5780 }
5782 }
5784 }
5786 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5787 must be a function or a pointer-to-function type, as specified
5788 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5789 and check that the resulting function has external linkage. */
5791 static tree
5793 tsubst_flags_t complain)
5794 {
5797 linkage_kind linkage;
5809 /* [temp.arg.nontype]/1
5811 A template-argument for a non-type, non-template template-parameter
5812 shall be one of:
5813 [...]
5814 -- the address of an object or function with external [C++11: or
5815 internal] linkage. */
5818 {
5820 {
5826 else
5829 }
5831 }
5835 {
5837 {
5842 else
5846 }
5848 }
5851 }
5853 /* Subroutine of convert_nontype_argument.
5854 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5855 Emit an error otherwise. */
5857 static bool
5859 tsubst_flags_t complain)
5860 {
5871 {
5875 }
5877 }
5879 /* Returns TRUE iff the address of OP is value-dependent.
5881 14.6.2.4 [temp.dep.temp]:
5882 A non-integral non-type template-argument is dependent if its type is
5883 dependent or it has either of the following forms
5884 qualified-id
5885 & qualified-id
5886 and contains a nested-name-specifier which specifies a class-name that
5887 names a dependent type.
5889 We generalize this to just say that the address of a member of a
5890 dependent class is value-dependent; the above doesn't cover the
5891 address of a static data member named with an unqualified-id. */
5893 static bool
5895 {
5896 /* We could use get_inner_reference here, but there's no need;
5897 this is only relevant for template non-type arguments, which
5898 can only be expressed as &id-expression. */
5900 {
5904 }
5907 }
5909 /* The next set of functions are used for providing helpful explanatory
5910 diagnostics for failed overload resolution. Their messages should be
5911 indented by two spaces for consistency with the messages in
5912 call.c */
5914 static int
5916 {
5918 }
5920 static int
5922 {
5927 }
5929 static int
5931 {
5933 }
5935 static int
5937 {
5943 }
5945 static int
5947 {
5951 }
5953 static int
5955 {
5958 " template parameter %qD is not a parameter pack, but "
5962 }
5964 static int
5966 {
5969 " template argument %qE does not match "
5973 }
5975 static int
5977 {
5981 }
5983 static int
5985 {
5991 }
5993 static int
5995 {
5997 {
6002 else
6004 " deduced conflicting values for non-type parameter "
6006 }
6008 }
6010 static int
6012 {
6015 " variable-sized array type %qT is not "
6017 arg);
6019 }
6021 static int
6023 {
6027 arg);
6029 }
6031 static int
6033 {
6035 {
6041 else
6046 }
6048 }
6050 static int
6052 {
6054 }
6056 static int
6059 {
6061 }
6063 static int
6066 {
6072 }
6074 static int
6077 {
6080 {
6088 }
6090 }
6092 static int
6094 {
6097 " template parameters of a template template argument are "
6100 }
6102 static int
6104 {
6110 }
6112 static int
6114 {
6119 }
6121 static int
6123 {
6127 arg);
6129 }
6131 /* Attempt to convert the non-type template parameter EXPR to the
6132 indicated TYPE. If the conversion is successful, return the
6133 converted value. If the conversion is unsuccessful, return
6134 NULL_TREE if we issued an error message, or error_mark_node if we
6135 did not. We issue error messages for out-and-out bad template
6136 parameters, but not simply because the conversion failed, since we
6137 might be just trying to do argument deduction. Both TYPE and EXPR
6138 must be non-dependent.
6140 The conversion follows the special rules described in
6141 [temp.arg.nontype], and it is much more strict than an implicit
6142 conversion.
6144 This function is called twice for each template argument (see
6145 lookup_template_class for a more accurate description of this
6146 problem). This means that we need to handle expressions which
6147 are not valid in a C++ source, but can be created from the
6148 first call (for instance, casts to perform conversions). These
6149 hacks can go away after we fix the double coercion problem. */
6151 static tree
6153 {
6154 tree expr_type;
6156 /* Detect immediately string literals as invalid non-type argument.
6157 This special-case is not needed for correctness (we would easily
6158 catch this later), but only to provide better diagnostic for this
6159 common user mistake. As suggested by DR 100, we do not mention
6160 linkage issues in the diagnostic as this is not the point. */
6161 /* FIXME we're making this OK. */
6163 {
6169 }
6171 /* Add the ADDR_EXPR now for the benefit of
6172 value_dependent_expression_p. */
6175 {
6179 }
6181 /* If we are in a template, EXPR may be non-dependent, but still
6182 have a syntactic, rather than semantic, form. For example, EXPR
6183 might be a SCOPE_REF, rather than the VAR_DECL to which the
6184 SCOPE_REF refers. Preserving the qualifying scope is necessary
6185 so that access checking can be performed when the template is
6186 instantiated -- but here we need the resolved form so that we can
6187 convert the argument. */
6193 && processing_template_decl
6202 else
6205 /* If the argument is non-dependent, perform any conversions in
6206 non-dependent context as well. */
6211 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6212 to a non-type argument of "nullptr". */
6216 /* In C++11, integral or enumeration non-type template arguments can be
6217 arbitrary constant expressions. Pointer and pointer to
6218 member arguments can be general constant expressions that evaluate
6219 to a null value, but otherwise still need to be of a specific form. */
6221 {
6223 /* A PTRMEM_CST is already constant, and a valid template
6224 argument for a parameter of pointer to member type, we just want
6225 to leave it in that form rather than lower it to a
6230 {
6235 }
6236 }
6238 /* HACK: Due to double coercion, we can get a
6239 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6240 which is the tree that we built on the first call (see
6241 below when coercing to reference to object or to reference to
6242 function). We just strip everything and get to the arg.
6243 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6244 for examples. */
6246 {
6252 {
6253 /* ??? Maybe we could use convert_from_reference here, but we
6254 would need to relax its constraints because the NOP_EXPR
6255 could actually change the type to something more cv-qualified,
6256 and this is not folded by convert_from_reference. */
6261 && (same_type_ignoring_top_level_qualifiers_p
6264 {
6267 }
6268 }
6269 }
6271 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6272 parameter is a pointer to object, through decay and
6273 qualification conversion. Let's strip everything. */
6275 {
6280 {
6281 /* Skip the ADDR_EXPR only if it is part of the decay for
6282 an array. Otherwise, it is part of the original argument
6283 in the source code. */
6288 }
6289 }
6291 /* [temp.arg.nontype]/5, bullet 1
6293 For a non-type template-parameter of integral or enumeration type,
6294 integral promotions (_conv.prom_) and integral conversions
6295 (_conv.integral_) are applied. */
6297 {
6306 /* Notice that there are constant expressions like '4 % 0' which
6307 do not fold into integer constants. */
6309 {
6311 {
6322 /* else cxx_constant_value complained but gave us
6323 a real constant, so go ahead. */
6325 }
6326 else
6328 }
6330 /* Avoid typedef problems. */
6333 }
6334 /* [temp.arg.nontype]/5, bullet 2
6336 For a non-type template-parameter of type pointer to object,
6337 qualification conversions (_conv.qual_) and the array-to-pointer
6338 conversion (_conv.array_) are applied. */
6340 {
6341 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6343 A template-argument for a non-type, non-template template-parameter
6344 shall be one of: [...]
6346 -- the name of a non-type template-parameter;
6347 -- the address of an object or function with external linkage, [...]
6348 expressed as "& id-expression" where the & is optional if the name
6349 refers to a function or array, or if the corresponding
6350 template-parameter is a reference.
6352 Here, we do not care about functions, as they are invalid anyway
6353 for a parameter of type pointer-to-object. */
6356 /* Non-type template parameters are OK. */
6357 ;
6362 {
6364 {
6367 "because %qD is a variable, not the address of "
6370 }
6372 {
6378 }
6379 /* Other values, like integer constants, might be valid
6380 non-type arguments of some other type. */
6382 }
6383 else
6384 {
6385 tree decl;
6390 {
6395 }
6397 {
6403 }
6405 {
6410 }
6411 }
6420 }
6421 /* [temp.arg.nontype]/5, bullet 3
6423 For a non-type template-parameter of type reference to object, no
6424 conversions apply. The type referred to by the reference may be more
6425 cv-qualified than the (otherwise identical) type of the
6426 template-argument. The template-parameter is bound directly to the
6427 template-argument, which must be an lvalue. */
6429 {
6431 expr_type))
6435 {
6440 }
6443 {
6448 }
6450 /* [temp.arg.nontype]/1
6452 A template-argument for a non-type, non-template template-parameter
6453 shall be one of: [...]
6455 -- the address of an object or function with external linkage. */
6458 {
6461 {
6464 "because a reference variable does not have a constant "
6467 }
6468 }
6471 {
6477 }
6479 /* DR 1155 allows internal linkage in C++11 and up. */
6482 {
6488 }
6491 }
6492 /* [temp.arg.nontype]/5, bullet 4
6494 For a non-type template-parameter of type pointer to function, only
6495 the function-to-pointer conversion (_conv.func_) is applied. If the
6496 template-argument represents a set of overloaded functions (or a
6497 pointer to such), the matching function is selected from the set
6498 (_over.over_). */
6500 {
6501 /* If the argument is a template-id, we might not have enough
6502 context information to decay the pointer. */
6504 {
6508 }
6511 /* Null pointer values are OK in C++11. */
6517 }
6518 /* [temp.arg.nontype]/5, bullet 5
6520 For a non-type template-parameter of type reference to function, no
6521 conversions apply. If the template-argument represents a set of
6522 overloaded functions, the matching function is selected from the set
6523 (_over.over_). */
6525 {
6527 {
6529 {
6534 }
6536 }
6543 }
6544 /* [temp.arg.nontype]/5, bullet 6
6546 For a non-type template-parameter of type pointer to member function,
6547 no conversions apply. If the template-argument represents a set of
6548 overloaded member functions, the matching member function is selected
6549 from the set (_over.over_). */
6551 {
6556 /* [temp.arg.nontype] bullet 1 says the pointer to member
6557 expression must be a pointer-to-member constant. */
6561 /* There is no way to disable standard conversions in
6562 resolve_address_of_overloaded_function (called by
6563 instantiate_type). It is possible that the call succeeded by
6564 converting &B::I to &D::I (where B is a base of D), so we need
6565 to reject this conversion here.
6567 Actually, even if there was a way to disable standard conversions,
6568 it would still be better to reject them here so that we can
6569 provide a superior diagnostic. */
6571 {
6573 {
6577 /* If we are just one standard conversion off, explain. */
6581 }
6583 }
6584 }
6585 /* [temp.arg.nontype]/5, bullet 7
6587 For a non-type template-parameter of type pointer to data member,
6588 qualification conversions (_conv.qual_) are applied. */
6590 {
6591 /* [temp.arg.nontype] bullet 1 says the pointer to member
6592 expression must be a pointer-to-member constant. */
6599 }
6601 {
6603 {
6608 }
6610 }
6611 /* A template non-type parameter must be one of the above. */
6612 else
6615 /* Sanity check: did we actually convert the argument to the
6616 right type? */
6620 }
6622 /* Subroutine of coerce_template_template_parms, which returns 1 if
6623 PARM_PARM and ARG_PARM match using the rule for the template
6624 parameters of template template parameters. Both PARM and ARG are
6625 template parameters; the rest of the arguments are the same as for
6626 coerce_template_template_parms.
6627 */
6628 static int
6630 tree arg,
6631 tsubst_flags_t complain,
6632 tree in_decl,
6633 tree outer_args)
6634 {
6643 {
6645 /* We encounter instantiations of templates like
6646 template <template <template <class> class> class TT>
6647 class C; */
6648 {
6655 }
6656 /* Fall through. */
6661 /* Argument is a parameter pack but parameter is not. */
6666 /* The tsubst call is used to handle cases such as
6668 template <int> class C {};
6669 template <class T, template <T> class TT> class D {};
6670 D<int, C> d;
6672 i.e. the parameter list of TT depends on earlier parameters. */
6674 {
6679 }
6683 /* Argument is a parameter pack but parameter is not. */
6690 }
6693 }
6696 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6697 template template parameters. Both PARM_PARMS and ARG_PARMS are
6698 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6699 or PARM_DECL.
6701 Consider the example:
6702 template <class T> class A;
6703 template<template <class U> class TT> class B;
6705 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6706 the parameters to A, and OUTER_ARGS contains A. */
6708 static int
6710 tree arg_parms,
6711 tsubst_flags_t complain,
6712 tree in_decl,
6713 tree outer_args)
6714 {
6725 /* Determine whether we have a parameter pack at the end of the
6726 template template parameter's template parameter list. */
6728 {
6735 {
6749 }
6750 }
6756 /* Check all of the template parameters except the parameter pack at
6757 the end (if any). */
6759 {
6768 outer_args))
6771 }
6774 {
6775 /* Check each of the template parameters in the template
6776 argument against the template parameter pack at the end of
6777 the template template parameter. */
6784 {
6791 outer_args))
6793 }
6794 }
6797 }
6799 /* Verifies that the deduced template arguments (in TARGS) for the
6800 template template parameters (in TPARMS) represent valid bindings,
6801 by comparing the template parameter list of each template argument
6802 to the template parameter list of its corresponding template
6803 template parameter, in accordance with DR150. This
6804 routine can only be called after all template arguments have been
6805 deduced. It will return TRUE if all of the template template
6806 parameter bindings are okay, FALSE otherwise. */
6807 bool
6809 {
6813 /* We're dealing with template parms in this process. */
6819 {
6824 {
6829 {
6830 /* Look inside the argument pack. */
6833 }
6836 {
6840 /* Extract the next argument from the argument
6841 pack. */
6845 /* Look at the pattern of the pack expansion. */
6848 /* Extract the template parameters from the template
6849 argument. */
6855 /* Verify that we can coerce the template template
6856 parameters from the template argument to the template
6857 parameter. This requires an exact match. */
6859 && !coerce_template_template_parms
6861 targ_parms,
6862 tf_none,
6863 tparm,
6864 targs))
6865 {
6868 }
6869 }
6870 }
6871 }
6873 out:
6877 }
6879 /* Since type attributes aren't mangled, we need to strip them from
6880 template type arguments. */
6882 static tree
6884 {
6893 }
6895 // A template declaration can be substituted for a constrained
6896 // template template parameter only when the argument is more
6897 // constrained than the parameter.
6898 static bool
6900 {
6903 /* For now, allow constrained template template arguments
6904 and unconstrained template template parameters. */
6910 // If the template parameter is constrained, we need to rewrite its
6911 // constraints in terms of the ARG's template parameters. This ensures
6912 // that all of the template parameter types will have the same depth.
6913 //
6914 // Note that this is only valid when coerce_template_template_parm is
6915 // true for the innermost template parameters of PARM and ARG. In other
6916 // words, because coercion is successful, this conversion will be valid.
6918 {
6925 }
6928 }
6930 // Convert a placeholder argument into a binding to the original
6931 // parameter. The original parameter is saved as the TREE_TYPE of
6932 // ARG.
6935 {
6938 }
6940 /* Convert the indicated template ARG as necessary to match the
6941 indicated template PARM. Returns the converted ARG, or
6942 error_mark_node if the conversion was unsuccessful. Error and
6943 warning messages are issued under control of COMPLAIN. This
6944 conversion is for the Ith parameter in the parameter list. ARGS is
6945 the full set of template arguments deduced so far. */
6947 static tree
6949 tree arg,
6950 tree args,
6951 tsubst_flags_t complain,
6953 tree in_decl)
6954 {
6955 tree orig_arg;
6956 tree val;
6962 /* Trivially convert placeholders. */
6968 {
6969 /* The template argument was the name of some
6970 member function. That's usually
6971 invalid, but static members are OK. In any
6972 case, grab the underlying fields/functions
6973 and issue an error later if required. */
6976 }
6984 /* When determining whether an argument pack expansion is a template,
6985 look at the pattern. */
6989 /* Deal with an injected-class-name used as a template template arg. */
6991 {
6994 {
7004 }
7005 }
7007 is_tmpl_type =
7023 {
7025 {
7029 }
7032 "to refer to a type member of a template parameter, "
7037 typename_type,
7038 complain);
7041 }
7043 {
7045 {
7047 {
7059 else
7062 }
7063 }
7065 }
7067 {
7069 {
7076 else
7079 }
7081 }
7084 {
7086 {
7090 /* The number of argument required is not known yet.
7091 Just accept it for now. */
7093 else
7094 {
7096 tree argparm;
7098 /* Strip alias templates that are equivalent to another
7099 template. */
7105 args))
7106 {
7109 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7110 TEMPLATE_DECL. */
7112 {
7117 }
7118 }
7119 else
7120 {
7122 {
7129 }
7132 }
7134 // Check that the constraints are compatible before allowing the
7135 // substitution.
7138 {
7140 {
7146 }
7148 }
7149 }
7150 }
7151 else
7153 /* We only form one instance of each template specialization.
7154 Therefore, if we use a non-canonical variant (i.e., a
7155 typedef), any future messages referring to the type will use
7156 the typedef, which is confusing if those future uses do not
7157 themselves also use the typedef. */
7160 }
7161 else
7162 {
7169 {
7172 else
7173 {
7174 /* Not sure if this is reachable, but it doesn't hurt
7175 to be robust. */
7178 }
7179 }
7182 /* We used to call digest_init here. However, digest_init
7183 will report errors, which we don't want when complain
7184 is zero. More importantly, digest_init will try too
7185 hard to convert things: for example, `0' should not be
7186 converted to pointer type at this point according to
7187 the standard. Accepting this is not merely an
7188 extension, since deciding whether or not these
7189 conversions can occur is part of determining which
7190 function template to call, or whether a given explicit
7191 argument specification is valid. */
7193 else
7194 {
7197 }
7205 {
7206 /* Reject template arguments that are references to built-in
7207 functions with no library fallbacks. */
7214 }
7217 {
7218 /* Strip typedefs from the SCOPE_REF. */
7221 complain);
7224 }
7225 }
7228 }
7230 /* Coerces the remaining template arguments in INNER_ARGS (from
7231 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7232 Returns the coerced argument pack. PARM_IDX is the position of this
7233 parameter in the template parameter list. ARGS is the original
7234 template argument list. */
7235 static tree
7238 tree args,
7239 tree inner_args,
7241 tree new_args,
7243 tree in_decl,
7244 tsubst_flags_t complain)
7245 {
7248 tree packed_args;
7249 tree argument_pack;
7256 {
7257 /* When the template parameter is a non-type template parameter pack
7258 or template template parameter pack whose type or template
7259 parameters use parameter packs, we know exactly how many arguments
7260 we are looking for. Build a vector of the instantiated decls for
7261 these template parameters in PACKED_PARMS. */
7262 /* We can't use make_pack_expansion here because it would interpret a
7263 _DECL as a use rather than a declaration. */
7277 /* If we're doing a partial instantiation of a member template,
7278 verify that all of the types used for the non-type
7279 template parameter pack are, in fact, valid for non-type
7280 template parameters. */
7283 {
7286 {
7290 }
7291 /* We don't know how many args we have yet, just
7292 use the unconverted ones for now. */
7294 }
7297 }
7298 /* Check if we have a placeholder pack, which indicates we're
7299 in the context of a introduction list. In that case we want
7300 to match this pack to the single placeholder. */
7304 {
7307 }
7308 else
7311 /* Convert the remaining arguments, which will be a part of the
7312 parameter pack "parm". */
7314 {
7320 {
7321 /* Once we've packed as many args as we have types, stop. */
7325 /* We don't know how many args we have yet, just
7326 use the unconverted ones for now. */
7328 else
7330 }
7333 {
7336 }
7337 else
7340 in_decl);
7344 }
7348 {
7353 }
7358 else
7359 {
7364 }
7367 #ifdef ENABLE_CHECKING
7370 #endif
7372 }
7374 /* Returns the number of pack expansions in the template argument vector
7375 ARGS. */
7377 static int
7379 {
7384 {
7388 }
7390 }
7392 /* Convert all template arguments to their appropriate types, and
7393 return a vector containing the innermost resulting template
7394 arguments. If any error occurs, return error_mark_node. Error and
7395 warning messages are issued under control of COMPLAIN.
7397 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7398 for arguments not specified in ARGS. Otherwise, if
7399 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7400 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7401 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7402 ARGS. */
7404 static tree
7406 tree args,
7407 tree in_decl,
7408 tsubst_flags_t complain,
7411 {
7413 tree orig_inner_args;
7414 tree inner_args;
7415 tree new_args;
7416 tree new_inner_args;
7420 /* When used as a boolean value, indicates whether this is a
7421 variadic template parameter list. Since it's an int, we can also
7422 subtract it from nparms to get the number of non-variadic
7423 parameters. */
7428 /* Likewise for parameters with default arguments. */
7436 /* Determine if there are any parameter packs or default arguments. */
7438 {
7446 }
7449 /* If there are no parameters that follow a parameter pack, we need to
7450 expand any argument packs so that we can deduce a parameter pack from
7451 some non-packed args followed by an argument pack, as in variadic85.C.
7452 If there are such parameters, we need to leave argument packs intact
7453 so the arguments are assigned properly. This can happen when dealing
7454 with a nested class inside a partial specialization of a class
7455 template, as in variadic92.C, or when deducing a template parameter pack
7456 from a sub-declarator, as in variadic114.C. */
7460 /* Count any pack expansion args. */
7466 && require_all_args
7467 && !variadic_args_p
7468 && (!use_default_args
7471 {
7473 {
7475 {
7479 }
7480 else
7487 }
7490 }
7491 /* We can't pass a pack expansion to a non-pack parameter of an alias
7492 template (DR 1430). */
7496 && variadic_args_p
7498 {
7500 {
7502 {
7508 {
7511 "pack expansion argument for non-pack parameter "
7513 else
7515 "pack expansion argument for non-pack parameter "
7519 }
7520 }
7522 found:;
7523 }
7525 }
7527 /* We need to evaluate the template arguments, even though this
7528 template-id may be nested within a "sizeof". */
7537 {
7538 tree arg;
7539 tree parm;
7541 /* Get the Ith template parameter. */
7545 {
7548 }
7550 /* Calculate the next argument. */
7553 else
7558 {
7559 /* Some arguments will be placed in the
7560 template parameter pack PARM. */
7567 {
7568 /* We don't know how many args we have yet, just use the
7569 unconverted (and still packed) ones for now. */
7573 }
7577 /* Store this argument. */
7579 {
7580 lost++;
7581 /* We are done with all of the arguments. */
7583 }
7584 else
7585 {
7588 }
7591 }
7593 {
7595 {
7596 /* "If every valid specialization of a variadic template
7597 requires an empty template parameter pack, the template is
7598 ill-formed, no diagnostic required." So check that the
7599 pattern works with this parameter. */
7604 in_decl);
7606 {
7610 }
7612 /* Recover from missing typename. */
7616 /* We don't know how many args we have yet, just
7617 use the unconverted ones for now. */
7621 }
7622 }
7624 {
7625 /* There must be a default arg in this case. */
7628 /* The position of the first default template argument,
7629 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7630 Record that. */
7634 }
7635 else
7639 {
7642 }
7644 /* This only occurs if there was an error in the template
7645 parameter list itself (which we would already have
7646 reported) that we are trying to recover from, e.g., a class
7647 template with a parameter list such as
7648 template<typename..., typename>. */
7650 else
7656 lost++;
7658 }
7663 {
7665 {
7670 }
7672 }
7677 #ifdef ENABLE_CHECKING
7681 #endif
7684 }
7686 /* Convert all template arguments to their appropriate types, and
7687 return a vector containing the innermost resulting template
7688 arguments. If any error occurs, return error_mark_node. Error and
7689 warning messages are not issued.
7691 Note that no function argument deduction is performed, and default
7692 arguments are used to fill in unspecified arguments. */
7693 tree
7695 {
7697 }
7699 /* Convert all template arguments to their appropriate type, and
7700 instantiate default arguments as needed. This returns a vector
7701 containing the innermost resulting template arguments, or
7702 error_mark_node if unsuccessful. */
7703 tree
7705 tsubst_flags_t complain)
7706 {
7708 }
7710 /* Like coerce_template_parms. If PARMS represents all template
7711 parameters levels, this function returns a vector of vectors
7712 representing all the resulting argument levels. Note that in this
7713 case, only the innermost arguments are coerced because the
7714 outermost ones are supposed to have been coerced already.
7716 Otherwise, if PARMS represents only (the innermost) vector of
7717 parameters, this function returns a vector containing just the
7718 innermost resulting arguments. */
7720 static tree
7722 tree args,
7723 tree in_decl,
7724 tsubst_flags_t complain,
7727 {
7730 tree coerced_args;
7733 {
7735 tree level;
7741 {
7742 tree l;
7746 require_all_args,
7747 use_default_args);
7748 else
7755 }
7756 }
7757 else
7760 require_all_args,
7761 use_default_args);
7763 }
7765 /* Returns 1 if template args OT and NT are equivalent. */
7767 static int
7769 {
7776 /* For member templates */
7785 {
7802 }
7804 {
7805 /* We get here probably because we are in the middle of substituting
7806 into the pattern of a pack expansion. In that case the
7807 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7808 interested in. So we want to use the initial pack argument for
7809 the comparison. */
7814 }
7816 {
7819 /* Don't treat an alias template specialization with dependent
7820 arguments as equivalent to its underlying type when used as a
7821 template argument; we need them to be distinct so that we
7822 substitute into the specialization arguments at instantiation
7823 time. And aliases can't be equivalent without being ==, so
7824 we don't need to look any deeper. */
7827 else
7829 }
7832 else
7833 {
7834 /* Try to treat a template non-type argument that has been converted
7835 to the parameter type as equivalent to one that hasn't yet. */
7848 }
7849 }
7851 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7852 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7853 NEWARG_PTR with the offending arguments if they are non-NULL. */
7855 static int
7858 {
7871 {
7876 {
7882 }
7883 }
7885 }
7887 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7888 of template arguments. Returns 0 otherwise. */
7890 int
7892 {
7894 }
7896 static void
7898 {
7908 /* We are called both from instantiate_decl, where we've already had a
7909 tinst_level pushed, and instantiate_template, where we haven't.
7910 Compensate. */
7921 else
7930 }
7933 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7934 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7935 documentation for TEMPLATE_ID_EXPR. */
7937 tree
7939 {
7940 tree type;
7948 {
7951 }
7954 {
7956 unknown_type_node,
7958 arglist);
7960 }
7967 }
7969 /* Within the scope of a template class S<T>, the name S gets bound
7970 (in build_self_reference) to a TYPE_DECL for the class, not a
7971 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7972 or one of its enclosing classes, and that type is a template,
7973 return the associated TEMPLATE_DECL. Otherwise, the original
7974 DECL is returned.
7976 Also handle the case when DECL is a TREE_LIST of ambiguous
7977 injected-class-names from different bases. */
7979 tree
7981 {
7985 /* DR 176: A lookup that finds an injected-class-name (10.2
7986 [class.member.lookup]) can result in an ambiguity in certain cases
7987 (for example, if it is found in more than one base class). If all of
7988 the injected-class-names that are found refer to specializations of
7989 the same class template, and if the name is followed by a
7990 template-argument-list, the reference refers to the class template
7991 itself and not a specialization thereof, and is not ambiguous. */
7993 {
7996 {
8002 }
8005 else
8007 }
8013 }
8015 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8016 parameters, find the desired type.
8018 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8020 IN_DECL, if non-NULL, is the template declaration we are trying to
8021 instantiate.
8023 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8024 the class we are looking up.
8026 Issue error and warning messages under control of COMPLAIN.
8028 If the template class is really a local class in a template
8029 function, then the FUNCTION_CONTEXT is the function in which it is
8030 being instantiated.
8032 ??? Note that this function is currently called *twice* for each
8033 template-id: the first time from the parser, while creating the
8034 incomplete type (finish_template_type), and the second type during the
8035 real instantiation (instantiate_template_class). This is surely something
8036 that we want to avoid. It also causes some problems with argument
8037 coercion (see convert_nontype_argument for more information on this). */
8039 static tree
8042 {
8044 tree t;
8047 spec_entry elt;
8048 hashval_t hash;
8051 {
8055 else
8056 {
8063 }
8066 }
8068 {
8071 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8072 an implicit typename for the second A. Deal with it. */
8077 {
8080 }
8081 }
8084 {
8087 }
8089 {
8093 }
8095 {
8098 }
8100 /* Issue an error message if we didn't find a template. */
8102 {
8106 }
8109 /* Make sure it's a user visible template, if it was named by
8110 the user. */
8113 {
8115 {
8119 }
8121 }
8125 /* An alias that just changes the name of a template is equivalent to the
8126 other template, so if any of the arguments are pack expansions, strip
8127 the alias to avoid problems with a pack expansion passed to a non-pack
8128 alias template parameter (DR 1430). */
8133 {
8134 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
8135 template arguments */
8137 tree parm;
8138 tree arglist2;
8139 tree outer;
8143 /* Consider an example where a template template parameter declared as
8145 template <class T, class U = std::allocator<T> > class TT
8147 The template parameter level of T and U are one level larger than
8148 of TT. To proper process the default argument of U, say when an
8149 instantiation `TT<int>' is seen, we need to build the full
8150 arguments containing {int} as the innermost level. Outer levels,
8151 available when not appearing as default template argument, can be
8152 obtained from the arguments of the enclosing template.
8154 Suppose that TT is later substituted with std::vector. The above
8155 instantiation is `TT<int, std::allocator<T> >' with TT at
8156 level 1, and T at level 2, while the template arguments at level 1
8157 becomes {std::vector} and the inner level 2 is {int}. */
8163 {
8164 /* This is an argument of the current template, so we haven't set
8165 DECL_CONTEXT yet. */
8166 tree relevant_template_parms;
8168 /* Parameter levels that are greater than the level of the given
8169 template template parm are irrelevant. */
8176 }
8182 complain,
8192 }
8193 else
8194 {
8196 tree gen_tmpl;
8197 tree type_decl;
8205 /* An error occurred while building the template TEMPL, and a
8206 diagnostic has most certainly been emitted for that
8207 already. Let's propagate that error. */
8216 {
8217 /* We've been given an incomplete set of template arguments.
8218 For example, given:
8220 template <class T> struct S1 {
8221 template <class U> struct S2 {};
8222 template <class U> struct S2<U*> {};
8223 };
8225 we will be called with an ARGLIST of `U*', but the
8226 TEMPLATE will be `template <class T> template
8227 <class U> struct S1<T>::S2'. We must fill in the missing
8228 arguments. */
8229 arglist
8231 arglist);
8233 }
8235 /* Now we should have enough arguments. */
8238 /* From here on, we're only interested in the most general
8239 template. */
8241 /* Calculate the BOUND_ARGS. These will be the args that are
8242 actually tsubst'd into the definition to create the
8243 instantiation. */
8245 complain,
8250 /* We were unable to bind the arguments. */
8253 /* In the scope of a template class, explicit references to the
8254 template class refer to the type of the template, not any
8255 instantiation of it. For example, in:
8257 template <class T> class C { void f(C<T>); }
8259 the `C<T>' is just the same as `C'. Outside of the
8260 class, however, such a reference is an instantiation. */
8264 /* comp_template_args is expensive, check it last. */
8266 arglist))
8269 /* If we already have this specialization, return it. */
8279 /* If the the template's constraints are not satisfied,
8280 then we cannot form a valid type.
8282 Note that the check is deferred until after the hash
8283 lookup. This prevents redundant checks on previously
8284 instantiated specializations. */
8286 {
8288 {
8291 }
8293 }
8297 /* If the deduced arguments are invalid, then the binding
8298 failed. */
8302 complain))
8309 {
8314 }
8324 /* Create the type. */
8326 {
8327 /* The user referred to a specialization of an alias
8328 template represented by GEN_TMPL.
8330 [temp.alias]/2 says:
8332 When a template-id refers to the specialization of an
8333 alias template, it is equivalent to the associated
8334 type obtained by substitution of its
8335 template-arguments for the template-parameters in the
8336 type-id of the alias template. */
8339 /* Note that the call above (by indirectly calling
8340 register_specialization in tsubst_decl) registers the
8341 TYPE_DECL representing the specialization of the alias
8342 template. So next time someone substitutes ARGLIST for
8343 the template parms into the alias template (GEN_TMPL),
8344 she'll get that TYPE_DECL back. */
8348 }
8350 {
8352 {
8361 }
8362 else
8363 {
8364 /* We don't want to call start_enum for this type, since
8365 the values for the enumeration constants may involve
8366 template parameters. And, no one should be interested
8367 in the enumeration constants for such a type. */
8370 }
8374 }
8376 {
8383 /* A local class. Make sure the decl gets registered properly. */
8388 /* This instantiation is another name for the primary
8389 template type. Set the TYPE_CANONICAL field
8390 appropriately. */
8393 /* Some of the template arguments require structural
8394 equality testing, so this template class requires
8395 structural equality testing. */
8397 }
8398 else
8401 /* If we called start_enum or pushtag above, this information
8402 will already be set up. */
8404 {
8411 }
8412 else
8416 {
8422 {
8425 }
8426 }
8430 {
8434 {
8435 tree attributes
8439 ;
8442 else
8447 }
8448 }
8450 /* Let's consider the explicit specialization of a member
8451 of a class template specialization that is implicitly instantiated,
8452 e.g.:
8453 template<class T>
8454 struct S
8455 {
8456 template<class U> struct M {}; //#0
8457 };
8459 template<>
8460 template<>
8461 struct S<int>::M<char> //#1
8462 {
8463 int i;
8464 };
8465 [temp.expl.spec]/4 says this is valid.
8467 In this case, when we write:
8468 S<int>::M<char> m;
8470 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8471 the one of #0.
8473 When we encounter #1, we want to store the partial instantiation
8474 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8476 For all cases other than this "explicit specialization of member of a
8477 class template", we just want to store the most general template into
8478 the CLASSTYPE_TI_TEMPLATE of M.
8480 This case of "explicit specialization of member of a class template"
8481 only happens when:
8482 1/ the enclosing class is an instantiation of, and therefore not
8483 the same as, the context of the most general template, and
8484 2/ we aren't looking at the partial instantiation itself, i.e.
8485 the innermost arguments are not the same as the innermost parms of
8486 the most general template.
8488 So it's only when 1/ and 2/ happens that we want to use the partial
8489 instantiation of the member template in lieu of its most general
8490 template. */
8494 /* the enclosing class must be an instantiation... */
8497 {
8498 tree partial_inst_args;
8501 partial_inst_args =
8507 use_partial_inst_tmpl =
8508 /*...and we must not be looking at the partial instantiation
8509 itself. */
8511 partial_inst_args);
8512 }
8515 /* This case is easy; there are no member templates involved. */
8517 else
8518 {
8519 /* This is a full instantiation of a member template. Find
8520 the partial instantiation of which this is an instance. */
8522 /* Temporarily reduce by one the number of levels in the ARGLIST
8523 so as to avoid comparing the last set of arguments. */
8527 /* FOUND is either a proper class type, or an alias
8528 template specialization. In the later case, it's a
8529 TYPE_DECL, resulting from the substituting of arguments
8530 for parameters in the TYPE_DECL of the alias template
8531 done earlier. So be careful while getting the template
8532 of FOUND. */
8536 }
8538 // Build template info for the new specialization.
8547 /* Note this use of the partial instantiation so we can check it
8548 later in maybe_process_partial_specialization. */
8555 /* Now that the type has been registered on the instantiations
8556 list, we set up the enumerators. Because the enumeration
8557 constants may involve the enumeration type itself, we make
8558 sure to register the type first, and then create the
8559 constants. That way, doing tsubst_expr for the enumeration
8560 constants won't result in recursive calls here; we'll find
8561 the instantiation and exit above. */
8565 /* If the type makes use of template parameters, the
8566 code that generates debugging information will crash. */
8569 /* Possibly limit visibility based on template args. */
8576 }
8577 }
8579 /* Wrapper for lookup_template_class_1. */
8581 tree
8584 {
8585 tree ret;
8591 }
8593 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
8595 tree
8597 {
8598 /* The type of the expression is NULL_TREE since the template-id could refer
8599 to an explicit or partial specialization. */
8602 /* Except that concepts are always bool. */
8605 }
8607 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8609 tree
8611 {
8615 /* We never want to return a VAR_DECL for a variable concept, since they
8616 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
8630 {
8632 {
8635 }
8637 }
8639 /* If a template-id refers to a specialization of a variable
8640 concept, then the expression is true if and only if the
8641 concept's constraints are satisfied by the given template
8642 arguments.
8644 NOTE: This is an extension of Concepts Lite TS that
8645 allows constraints to be used in expressions. */
8647 {
8650 }
8653 }
8654 \f
8655 struct pair_fn_data
8656 {
8657 tree_fn_t fn;
8659 /* True when we should also visit template parameters that occur in
8660 non-deduced contexts. */
8663 };
8665 /* Called from for_each_template_parm via walk_tree. */
8667 static tree
8669 {
8682 {
8686 /* Fall through. */
8709 /* Since we're not going to walk subtrees, we have to do this
8710 explicitly here. */
8714 /* Fall through. */
8717 /* Check the return type. */
8722 /* Check the parameter types. Since default arguments are not
8723 instantiated until they are needed, the TYPE_ARG_TYPES may
8724 contain expressions that involve template parameters. But,
8725 no-one should be looking at them yet. And, once they're
8726 instantiated, they don't contain template parameters, so
8727 there's no point in looking at them then, either. */
8728 {
8729 tree parm;
8736 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8737 want walk_tree walking into them itself. */
8739 }
8757 /* Fall through. */
8773 /* Record template parameters such as `T' inside `TT<T>'. */
8777 /* Fall through. */
8789 /* A template template parameter is encountered. */
8795 /* Already substituted template template parameter */
8818 /* If there's no type, then this thing must be some expression
8819 involving template parameters. */
8841 }
8843 /* We didn't find any template parameters we liked. */
8845 }
8847 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8848 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8849 call FN with the parameter and the DATA.
8850 If FN returns nonzero, the iteration is terminated, and
8851 for_each_template_parm returns 1. Otherwise, the iteration
8852 continues. If FN never returns a nonzero value, the value
8853 returned by for_each_template_parm is 0. If FN is NULL, it is
8854 considered to be the function which always returns 1.
8856 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8857 parameters that occur in non-deduced contexts. When false, only
8858 visits those template parameters that can be deduced. */
8860 static int
8864 {
8868 /* Set up. */
8873 /* Walk the tree. (Conceptually, we would like to walk without
8874 duplicates, but for_each_template_parm_r recursively calls
8875 for_each_template_parm, so we would need to reorganize a fair
8876 bit to use walk_tree_without_duplicates, so we keep our own
8877 visited list.) */
8880 else
8883 for_each_template_parm_r,
8887 /* Clean up. */
8889 {
8892 }
8895 }
8897 /* Returns true if T depends on any template parameter. */
8899 int
8901 {
8931 else
8932 {
8935 }
8940 }
8942 /* Returns true iff current_function_decl is an incompletely instantiated
8943 template. Useful instead of processing_template_decl because the latter
8944 is set to 0 during instantiate_non_dependent_expr. */
8946 bool
8948 {
8957 }
8959 /* Returns true if T depends on any template parameter with level LEVEL. */
8961 int
8963 {
8966 }
8968 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8969 ill-formed translation unit, i.e. a variable or function that isn't
8970 usable in a constant expression. */
8974 {
8978 }
8980 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8981 neglectable and instantiated from within an erroneous instantiation. */
8983 static bool
8985 {
8996 }
9004 /* We're starting to instantiate D; record the template instantiation context
9005 for diagnostics and to restore it later. */
9007 bool
9009 {
9011 }
9013 /* We're starting to instantiate D; record the template instantiation context
9014 at LOC for diagnostics and to restore it later. */
9016 bool
9018 {
9022 {
9024 "template instantiation depth exceeds maximum of %d"
9026 max_tinst_depth);
9028 }
9030 /* If the current instantiation caused problems, don't let it instantiate
9031 anything else. Do allow deduction substitution and decls usable in
9032 constant expressions. */
9049 }
9051 /* We're done instantiating this template; return to the instantiation
9052 context. */
9054 void
9056 {
9057 /* Restore the filename and line number stashed away when we started
9058 this instantiation. */
9062 }
9064 /* We're instantiating a deferred template; restore the template
9065 instantiation context in which the instantiation was requested, which
9066 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9068 static tree
9070 {
9082 }
9084 /* Returns the TINST_LEVEL which gives the original instantiation
9085 context. */
9089 {
9095 }
9097 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9098 vector of template arguments, as for tsubst.
9100 Returns an appropriate tsubst'd friend declaration. */
9102 static tree
9104 {
9105 tree new_friend;
9110 /* This was a friend declared with an explicit template
9111 argument list, e.g.:
9113 friend void f<>(T);
9115 to indicate that f was a template instantiation, not a new
9116 function declaration. Now, we have to figure out what
9117 instantiation of what template. */
9118 {
9120 tree new_args;
9121 tree tmpl;
9124 /* Friend functions are looked up in the containing namespace scope.
9125 We must enter that scope, to avoid finding member functions of the
9126 current class with same name. */
9141 tsk_none);
9143 }
9147 /* The NEW_FRIEND will look like an instantiation, to the
9148 compiler, but is not an instantiation from the point of view of
9149 the language. For example, we might have had:
9151 template <class T> struct S {
9152 template <class U> friend void f(T, U);
9153 };
9155 Then, in S<int>, template <class U> void f(int, U) is not an
9156 instantiation of anything. */
9162 {
9166 }
9168 /* The mangled name for the NEW_FRIEND is incorrect. The function
9169 is not a template instantiation and should not be mangled like
9170 one. Therefore, we forget the mangling here; we'll recompute it
9171 later if we need it. */
9173 {
9176 }
9179 {
9180 tree old_decl;
9181 tree new_friend_template_info;
9182 tree new_friend_result_template_info;
9183 tree ns;
9186 /* We must save some information from NEW_FRIEND before calling
9187 duplicate decls since that function will free NEW_FRIEND if
9188 possible. */
9190 new_friend_is_defn =
9195 {
9196 /* This declaration is a `primary' template. */
9199 new_friend_result_template_info
9201 }
9202 else
9205 /* Make the init_value nonzero so pushdecl knows this is a defn. */
9209 /* Inside pushdecl_namespace_level, we will push into the
9210 current namespace. However, the friend function should go
9211 into the namespace of the template. */
9221 {
9222 /* This new friend declaration matched an existing
9223 declaration. For example, given:
9225 template <class T> void f(T);
9226 template <class U> class C {
9227 template <class T> friend void f(T) {}
9228 };
9230 the friend declaration actually provides the definition
9231 of `f', once C has been instantiated for some type. So,
9232 old_decl will be the out-of-class template declaration,
9233 while new_friend is the in-class definition.
9235 But, if `f' was called before this point, the
9236 instantiation of `f' will have DECL_TI_ARGS corresponding
9237 to `T' but not to `U', references to which might appear
9238 in the definition of `f'. Previously, the most general
9239 template for an instantiation of `f' was the out-of-class
9240 version; now it is the in-class version. Therefore, we
9241 run through all specialization of `f', adding to their
9242 DECL_TI_ARGS appropriately. In particular, they need a
9243 new set of outer arguments, corresponding to the
9244 arguments for this class instantiation.
9246 The same situation can arise with something like this:
9248 friend void f(int);
9249 template <class T> class C {
9250 friend void f(T) {}
9251 };
9253 when `C<int>' is instantiated. Now, `f(int)' is defined
9254 in the class. */
9257 /* On the other hand, if the in-class declaration does
9258 *not* provide a definition, then we don't want to alter
9259 existing definitions. We can just leave everything
9260 alone. */
9261 ;
9262 else
9263 {
9267 /* Overwrite whatever template info was there before, if
9268 any, with the new template information pertaining to
9269 the declaration. */
9273 {
9274 /* We should have called reregister_specialization in
9275 duplicate_decls. */
9280 /* Instantiate it if the global has already been used. */
9284 }
9285 else
9286 {
9287 tree t;
9289 /* Indicate that the old function template is a partial
9290 instantiation. */
9298 /* Reassign any specializations already in the hash table
9299 to the new more general template, and add the
9300 additional template args. */
9304 {
9306 spec_entry elt;
9318 register_specialization
9321 }
9323 }
9324 }
9326 /* The information from NEW_FRIEND has been merged into OLD_DECL
9327 by duplicate_decls. */
9329 }
9330 }
9331 else
9332 {
9336 /* In the code
9337 template <class T> class C {
9338 template <class U> friend void C1<U>::f (); // case 1
9339 friend void C2<T>::f (); // case 2
9340 };
9341 we only need to make sure CONTEXT is a complete type for
9342 case 2. To distinguish between the two cases, we note that
9343 CONTEXT of case 1 remains dependent type after tsubst while
9344 this isn't true for case 2. */
9354 {
9356 /* do_friend adds the TEMPLATE_DECL for any member friend
9357 template even if it isn't a member template, i.e.
9358 template <class T> friend A<T>::f();
9359 Look through it in that case. */
9363 /* Check to see that the declaration is really present, and,
9364 possibly obtain an improved declaration. */
9369 }
9370 }
9373 }
9375 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9376 template arguments, as for tsubst.
9378 Returns an appropriate tsubst'd friend type or error_mark_node on
9379 failure. */
9381 static tree
9383 {
9384 tree friend_type;
9385 tree tmpl;
9386 tree context;
9389 {
9392 }
9397 {
9400 else
9402 }
9404 /* Look for a class template declaration. We look for hidden names
9405 because two friend declarations of the same template are the
9406 same. For example, in:
9408 struct A {
9409 template <typename> friend class F;
9410 };
9411 template <typename> struct B {
9412 template <typename> friend class F;
9413 };
9415 both F templates are the same. */
9419 /* But, if we don't find one, it might be because we're in a
9420 situation like this:
9422 template <class T>
9423 struct S {
9424 template <class U>
9425 friend struct S;
9426 };
9428 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9429 for `S<int>', not the TEMPLATE_DECL. */
9431 {
9434 }
9437 {
9438 /* The friend template has already been declared. Just
9439 check to see that the declarations match, and install any new
9440 default parameters. We must tsubst the default parameters,
9441 of course. We only need the innermost template parameters
9442 because that is all that redeclare_class_template will look
9443 at. */
9446 {
9447 tree parms;
9448 location_t saved_input_location;
9458 }
9461 }
9462 else
9463 {
9464 /* The friend template has not already been declared. In this
9465 case, the instantiation of the template class will cause the
9466 injection of this template into the global scope. */
9471 /* The new TMPL is not an instantiation of anything, so we
9472 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
9473 the new type because that is supposed to be the corresponding
9474 template decl, i.e., TMPL. */
9481 /* Inject this template into the global scope. */
9483 }
9486 {
9489 else
9491 }
9494 }
9496 /* Returns zero if TYPE cannot be completed later due to circularity.
9497 Otherwise returns one. */
9499 static int
9501 {
9511 else
9513 }
9517 /* Apply any attributes which had to be deferred until instantiation
9518 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
9519 ARGS, COMPLAIN, IN_DECL are as tsubst. */
9521 static void
9524 {
9526 tree t;
9531 {
9535 }
9538 {
9542 }
9543 else
9547 {
9552 {
9555 {
9562 {
9569 clauses
9573 else
9575 }
9576 /* If the first attribute argument is an identifier, don't
9577 pass it through tsubst. Attributes like mode, format,
9578 cleanup and several target specific attributes expect it
9579 unmodified. */
9582 {
9583 tree chain
9585 in_decl,
9590 chain);
9591 }
9593 {
9594 /* An attribute pack expansion. */
9596 tree pack = (tsubst_pack_expansion
9600 {
9604 }
9606 }
9607 else
9613 }
9614 else
9616 }
9619 }
9620 }
9622 /* Perform (or defer) access check for typedefs that were referenced
9623 from within the template TMPL code.
9624 This is a subroutine of instantiate_decl and instantiate_class_template.
9625 TMPL is the template to consider and TARGS is the list of arguments of
9626 that template. */
9628 static void
9630 {
9631 location_t saved_location;
9642 {
9654 /* Make access check error messages point to the location
9655 of the use of the typedef. */
9659 tf_warning_or_error);
9660 }
9662 }
9664 static tree
9666 {
9668 tree typedecl;
9669 tree pbinfo;
9670 tree base_list;
9672 tree fn_context;
9681 /* Figure out which template is being instantiated. */
9685 /* Determine what specialization of the original template to
9686 instantiate. */
9689 {
9692 }
9694 {
9695 /* This TYPE is actually an instantiation of a partial
9696 specialization. We replace the innermost set of ARGS with
9697 the arguments appropriate for substitution. For example,
9698 given:
9700 template <class T> struct S {};
9701 template <class T> struct S<T*> {};
9703 and supposing that we are instantiating S<int*>, ARGS will
9704 presently be {int*} -- but we need {int}. */
9707 }
9708 else
9709 {
9712 }
9714 /* If the template we're instantiating is incomplete, then clearly
9715 there's nothing we can do. */
9719 /* If we've recursively instantiated too many templates, stop. */
9723 /* Now we're really doing the instantiation. Mark the type as in
9724 the process of being defined. */
9727 /* We may be in the middle of deferred access check. Disable
9728 it now. */
9735 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9740 else
9741 {
9744 }
9745 /* Use #pragma pack from the template context. */
9751 /* Set the input location to the most specialized template definition.
9752 This is needed if tsubsting causes an error. */
9764 {
9767 /* Adjust visibility for template arguments. */
9769 }
9775 /* We should never instantiate a nested class before its enclosing
9776 class; we need to look up the nested class by name before we can
9777 instantiate it, and that lookup should instantiate the enclosing
9778 class. */
9784 {
9785 tree pbase_binfo;
9786 tree pushed_scope;
9789 /* We must enter the scope containing the type, as that is where
9790 the accessibility of types named in dependent bases are
9791 looked up from. */
9794 /* Substitute into each of the bases to determine the actual
9795 basetypes. */
9797 {
9798 tree base;
9804 {
9805 expanded_bases =
9812 }
9815 {
9817 /* Extract the already-expanded base class. */
9819 else
9820 /* Substitute to figure out the base class. */
9822 NULL_TREE);
9830 }
9831 }
9833 /* The list is now in reverse order; correct that. */
9838 }
9839 /* Now call xref_basetypes to set up all the base-class
9840 information. */
9848 /* Now that our base classes are set up, enter the scope of the
9849 class, so that name lookups into base classes, etc. will work
9850 correctly. This is precisely analogous to what we do in
9851 begin_class_definition when defining an ordinary non-template
9852 class, except we also need to push the enclosing classes. */
9855 /* Now members are processed in the order of declaration. */
9858 {
9862 {
9864 {
9865 /* Build new CLASSTYPE_NESTED_UTDS. */
9867 tree newtag;
9873 /* If the member is a class template, then -- even after
9874 substitution -- there may be dependent types in the
9875 template argument list for the class. We increment
9876 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9877 that function will assume that no types are dependent
9878 when outside of a template. */
9888 {
9892 /* Unfortunately, lookup_template_class sets
9893 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9894 instantiation (i.e., for the type of a member
9895 template class nested within a template class.)
9896 This behavior is required for
9897 maybe_process_partial_specialization to work
9898 correctly, but is not accurate in this case;
9899 the TAG is not an instantiation of anything.
9900 (The corresponding TEMPLATE_DECL is an
9901 instantiation, but the TYPE is not.) */
9904 /* Now, we call pushtag to put this NEWTAG into the scope of
9905 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9906 pushtag calling push_template_decl. We don't have to do
9907 this for enums because it will already have been done in
9908 tsubst_enum. */
9912 }
9913 }
9915 {
9916 /* Build new TYPE_METHODS. */
9917 tree r;
9926 /* Instantiate members marked with attribute used. */
9932 }
9935 /* A closure type for a lambda in a default argument for a
9936 member template. Ignore it; it will be instantiated with
9938 else
9939 {
9940 /* Build new TYPE_FIELDS. */
9942 {
9943 tree condition;
9946 condition =
9956 }
9958 {
9959 tree r;
9963 /* The file and line for this declaration, to
9964 assist in error message reporting. Since we
9965 called push_tinst_level above, we don't need to
9966 restore these. */
9976 {
9977 /* A capture pack became multiple fields. */
9980 }
9983 {
9987 {
9988 /* In [temp.inst]:
9990 [t]he initialization (and any associated
9991 side-effects) of a static data member does
9992 not occur unless the static data member is
9993 itself used in a way that requires the
9994 definition of the static data member to
9995 exist.
9997 Therefore, we do not substitute into the
9998 initialized for the static data member here. */
9999 finish_static_data_member_decl
10005 /* Instantiate members marked with attribute used. */
10008 }
10010 {
10011 /* Determine whether R has a valid type and can be
10012 completed later. If R is invalid, then its type
10013 is replaced by error_mark_node. */
10019 {
10022 }
10023 }
10025 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10026 such a thing will already have been added to the field
10027 list by tsubst_enum in finish_member_declaration in the
10028 CLASSTYPE_NESTED_UTDS case above. */
10032 {
10035 }
10036 }
10037 }
10038 }
10039 }
10040 else
10041 {
10044 {
10045 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10051 {
10052 /* template <class T> friend class C; */
10055 }
10057 {
10058 /* template <class T> friend class C::D; */
10064 }
10067 {
10068 /* This could be either
10070 friend class T::C;
10072 when dependent_type_p is false or
10074 template <class U> friend class T::C;
10076 otherwise. */
10079 /* Bump processing_template_decl for correct
10080 dependent_type_p calculation. */
10085 }
10088 {
10089 /* friend class C;
10091 where C hasn't been declared yet. Let's lookup name
10092 from namespace scope directly, bypassing any name that
10093 come from dependent base class. */
10096 /* The call to xref_tag_from_type does injection for friend
10097 classes. */
10099 friend_type =
10103 }
10105 /* friend class C<T>; */
10108 /* Otherwise it's
10110 friend class C;
10112 where C is already declared or
10114 friend class C<int>;
10116 We don't have to do anything in these cases. */
10119 /* Trick make_friend_class into realizing that the friend
10120 we're adding is a template, not an ordinary class. It's
10121 important that we use make_friend_class since it will
10122 perform some error-checking and output cross-reference
10123 information. */
10131 }
10132 else
10133 {
10134 /* Build new DECL_FRIENDLIST. */
10135 tree r;
10137 /* The file and line for this declaration, to
10138 assist in error message reporting. Since we
10139 called push_tinst_level above, we don't need to
10140 restore these. */
10144 {
10147 }
10152 {
10155 }
10156 }
10157 }
10158 }
10161 {
10162 /* Restore these before substituting into the lambda capture
10163 initializers. */
10166 }
10169 {
10172 {
10177 /* We need to instantiate the capture list from the template
10178 after we've instantiated the closure members, but before we
10179 consider adding the conversion op. Also keep any captures
10180 that may have been added during instantiation of the op(). */
10182 tree tmpl_cap
10191 }
10192 else
10194 }
10196 /* Set the file and line number information to whatever is given for
10197 the class itself. This puts error messages involving generated
10198 implicit functions at a predictable point, and the same point
10199 that would be used for non-template classes. */
10206 /* We don't instantiate default arguments for member functions. 14.7.1:
10208 The implicit instantiation of a class template specialization causes
10209 the implicit instantiation of the declarations, but not of the
10210 definitions or default arguments, of the class member functions,
10211 member classes, static data members and member templates.... */
10213 /* Some typedefs referenced from within the template code need to be access
10214 checked at template instantiation time, i.e now. These types were
10215 added to the template at parsing time. Let's get those and perform
10216 the access checks then. */
10226 /* The vtable for a template class can be emitted in any translation
10227 unit in which the class is instantiated. When there is no key
10228 method, however, finish_struct_1 will already have added TYPE to
10229 the keyed_classes list. */
10234 }
10236 /* Wrapper for instantiate_class_template_1. */
10238 tree
10240 {
10241 tree ret;
10246 }
10248 static tree
10250 {
10251 tree r;
10257 else
10258 {
10265 }
10267 }
10269 /* Given a function parameter pack TMPL_PARM and some function parameters
10270 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10271 and set *SPEC_P to point at the next point in the list. */
10273 tree
10275 {
10276 /* Collect all of the extra "packed" parameters into an
10277 argument pack. */
10278 tree parmvec;
10279 tree parmtypevec;
10290 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10295 {
10298 }
10300 /* Build the argument packs. */
10307 }
10309 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10310 NONTYPE_ARGUMENT_PACK. */
10312 static tree
10314 {
10316 }
10318 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10319 pack expansion with no extra args, 2 if it has extra args, or 0
10320 if it is not a pack expansion. */
10322 static int
10324 {
10330 /* A decl pack is itself an expansion. */
10337 }
10340 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10342 static tree
10344 {
10351 }
10353 /* This is a subroutine of tsubst_pack_expansion.
10355 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10356 mechanism to store the (non complete list of) arguments of the
10357 substitution and return a non substituted pack expansion, in order
10358 to wait for when we have enough arguments to really perform the
10359 substitution. */
10361 static bool
10365 {
10366 /* If one pack has an expansion and another pack has a normal
10367 argument or if one pack has an empty argument and an another
10368 one hasn't then tsubst_pack_expansion cannot perform the
10369 substitution and need to fall back on the
10370 PACK_EXPANSION_EXTRA mechanism. */
10378 {
10381 parm_pack;
10383 {
10388 /* We can't substitute a pack expansion with extra args into
10389 our pattern. */
10393 else
10395 }
10399 }
10401 }
10403 /* [temp.variadic]/6 says that:
10405 The instantiation of a pack expansion [...]
10406 produces a list E1,E2, ..., En, where N is the number of elements
10407 in the pack expansion parameters.
10409 This subroutine of tsubst_pack_expansion produces one of these Ei.
10411 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
10412 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
10413 PATTERN, and each TREE_VALUE is its corresponding argument pack.
10414 INDEX is the index 'i' of the element Ei to produce. ARGS,
10415 COMPLAIN, and IN_DECL are the same parameters as for the
10416 tsubst_pack_expansion function.
10418 The function returns the resulting Ei upon successful completion,
10419 or error_mark_node.
10421 Note that this function possibly modifies the ARGS parameter, so
10422 it's the responsibility of the caller to restore it. */
10424 static tree
10426 tree parm_packs,
10428 tree args /* This parm gets
10430 tsubst_flags_t complain,
10431 tree in_decl)
10432 {
10433 tree t;
10436 /* For each parameter pack, change the substitution of the parameter
10437 pack to the ith argument in its argument pack, then expand the
10438 pattern. */
10440 {
10445 ith_elem_is_expansion |=
10448 /* Select the Ith argument from the pack. */
10451 {
10453 {
10458 }
10459 else
10461 }
10462 else
10463 {
10468 {
10470 /* Update the corresponding argument. */
10472 }
10473 else
10474 /* Re-use the ARGUMENT_PACK_SELECT. */
10476 }
10478 }
10480 /* Substitute into the PATTERN with the (possibly altered)
10481 arguments. */
10483 /* Expanding a fixed parameter pack from
10484 coerce_template_parameter_pack. */
10489 {
10492 else
10495 }
10499 else
10502 /* If the Ith argument pack element is a pack expansion, then
10503 the Ith element resulting from the substituting is going to
10504 be a pack expansion as well. */
10509 }
10511 /* When the unexpanded parameter pack in a fold expression expands to an empty
10512 sequence, the value of the expression is as follows; the program is
10513 ill-formed if the operator is not listed in this table.
10515 * 1
10516 + 0
10517 & -1
10518 | 0
10519 && true
10520 || false
10521 , void() */
10523 tree
10525 {
10529 {
10546 }
10552 }
10554 /* Given a fold-expression T and a current LEFT and RIGHT operand,
10555 form an expression that combines the two terms using the
10556 operator of T. */
10558 static tree
10560 {
10564 // Handle compound assignment operators.
10569 {
10579 complain);
10580 }
10581 }
10583 /* Substitute ARGS into the pack of a fold expression T. */
10587 {
10589 }
10591 /* Substitute ARGS into the pack of a fold expression T. */
10595 {
10597 }
10599 /* Expand a PACK of arguments into a grouped as left fold.
10600 Given a pack containing elements A0, A1, ..., An and an
10601 operator @, this builds the expression:
10603 ((A0 @ A1) @ A2) ... @ An
10605 Note that PACK must not be empty.
10607 The operator is defined by the original fold expression T. */
10609 static tree
10611 {
10614 {
10617 }
10619 }
10621 /* Substitute into a unary left fold expression. */
10623 static tree
10625 tree in_decl)
10626 {
10630 else
10632 }
10634 /* Substitute into a binary left fold expression.
10636 Do ths by building a single (non-empty) vector of argumnts and
10637 building the expression from those elements. */
10639 static tree
10641 tree in_decl)
10642 {
10652 }
10654 /* Expand a PACK of arguments into a grouped as right fold.
10655 Given a pack containing elementns A0, A1, ..., and an
10656 operator @, this builds the expression:
10658 A0@ ... (An-2 @ (An-1 @ An))
10660 Note that PACK must not be empty.
10662 The operator is defined by the original fold expression T. */
10664 tree
10666 {
10667 // Build the expression.
10671 {
10674 }
10676 }
10678 /* Substitute into a unary right fold expression. */
10680 static tree
10682 tree in_decl)
10683 {
10687 else
10689 }
10691 /* Substitute into a binary right fold expression.
10693 Do ths by building a single (non-empty) vector of arguments and
10694 building the expression from those elements. */
10696 static tree
10698 tree in_decl)
10699 {
10710 }
10713 /* Substitute ARGS into T, which is an pack expansion
10714 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
10715 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
10716 (if only a partial substitution could be performed) or
10717 ERROR_MARK_NODE if there was an error. */
10718 tree
10720 tree in_decl)
10721 {
10722 tree pattern;
10726 tree result;
10734 /* Add in any args remembered from an earlier partial instantiation. */
10739 /* Determine the argument packs that will instantiate the parameter
10740 packs used in the expansion expression. While we're at it,
10741 compute the number of arguments to be expanded and make sure it
10742 is consistent. */
10745 {
10752 {
10756 else
10759 }
10761 {
10762 /* We know we have correct local_specializations if this
10763 expansion is at function scope, or if we're dealing with a
10764 local parameter in a requires expression; for the latter,
10765 tsubst_requires_expr set it up appropriately. */
10768 else
10769 {
10770 /* We can't rely on local_specializations for a parameter
10771 name used later in a function declaration (such as in a
10772 late-specified return type). Even if it exists, it might
10773 have the wrong value for a recursive call. Just make a
10774 dummy decl, since it's only used for its type. */
10777 /* Partial instantiation of the parm_pack, we can't build
10778 up an argument pack yet. */
10780 else
10783 }
10784 }
10787 else
10788 {
10794 }
10801 /* This can only happen if we forget to expand an argument
10802 pack somewhere else. Just return an error, silently. */
10803 {
10807 }
10810 {
10814 /* Don't bother trying to do a partial substitution with
10815 incomplete packs; we'll try again after deduction. */
10822 {
10828 pattern);
10829 else
10832 pattern);
10834 }
10836 /* Keep track of the parameter packs and their corresponding
10837 argument packs. */
10840 }
10841 else
10842 {
10843 /* We can't substitute for this parameter pack. We use a flag as
10844 well as the missing_level counter because function parameter
10845 packs don't have a level. */
10847 }
10848 }
10850 /* If the expansion is just T..., return the matching argument pack. */
10853 {
10858 /* Otherwise use the normal path so we get convert_from_reference. */
10859 }
10861 /* We cannot expand this expansion expression, because we don't have
10862 all of the argument packs we need. */
10864 {
10865 /* We got some full packs, but we can't substitute them in until we
10866 have values for all the packs. So remember these until then. */
10871 }
10873 {
10874 /* There were no real arguments, we're just replacing a parameter
10875 pack with another version of itself. Substitute into the
10876 pattern and return a PACK_EXPANSION_*. The caller will need to
10877 deal with that. */
10881 else
10885 }
10890 {
10891 /* We're in a late-specified return type, so create our own local
10892 specializations map; the current map is either NULL or (in the
10893 case of recursive unification) might have bindings that we don't
10894 want to use or alter. */
10897 }
10899 /* For each argument in each argument pack, substitute into the
10900 pattern. */
10903 {
10905 i,
10907 in_decl);
10910 {
10913 }
10914 }
10916 /* Update ARGS to restore the substitution from parameter packs to
10917 their argument packs. */
10919 {
10925 else
10926 {
10934 /* Update the corresponding argument. */
10938 else
10940 }
10941 }
10944 {
10947 }
10950 }
10952 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
10953 TMPL. We do this using DECL_PARM_INDEX, which should work even with
10954 parameter packs; all parms generated from a function parameter pack will
10955 have the same DECL_PARM_INDEX. */
10957 tree
10959 {
10961 tree patparm;
10964 {
10970 }
10971 else
10972 {
10977 }
10980 }
10982 /* Substitute ARGS into the vector or list of template arguments T. */
10984 static tree
10986 {
10998 {
11000 tree new_arg;
11005 {
11006 /* Substitute into an expansion expression. */
11010 /* Add to the expanded length adjustment the number of
11011 expanded arguments. We subtract one from this
11012 measurement, because the argument pack expression
11013 itself is already counted as 1 in
11014 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11015 the argument pack is empty. */
11017 }
11019 {
11020 /* Substitute into each of the arguments. */
11026 new_arg,
11040 }
11041 }
11042 else
11051 }
11056 /* Make space for the expanded arguments coming from template
11057 argument packs. */
11059 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11060 arguments for a member template.
11061 In that case each TREE_VEC in ORIG_T represents a level of template
11062 arguments, and ORIG_T won't carry any non defaulted argument count.
11063 It will rather be the nested TREE_VECs that will carry one.
11064 In other words, ORIG_T carries a non defaulted argument count only
11065 if it doesn't contain any nested TREE_VEC. */
11067 {
11071 }
11073 {
11077 {
11080 /* Now expand the template argument pack "in place". */
11083 }
11084 else
11085 {
11087 out++;
11088 }
11089 }
11092 }
11094 /* Return the result of substituting ARGS into the template parameters
11095 given by PARMS. If there are m levels of ARGS and m + n levels of
11096 PARMS, then the result will contain n levels of PARMS. For
11097 example, if PARMS is `template <class T> template <class U>
11098 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11099 result will be `template <int*, double, class V>'. */
11101 static tree
11103 {
11107 /* When substituting into a template, we must set
11108 PROCESSING_TEMPLATE_DECL as the template parameters may be
11109 dependent if they are based on one-another, and the dependency
11110 predicates are short-circuit outside of templates. */
11117 {
11118 tree new_vec =
11123 {
11124 tree tuple;
11136 }
11142 }
11147 }
11149 /* Return the result of substituting ARGS into one template parameter
11150 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11151 parameter and which TREE_PURPOSE is the default argument of the
11152 template parameter. */
11154 static tree
11156 {
11177 }
11179 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11180 type T. If T is not an aggregate or enumeration type, it is
11181 handled as if by tsubst. IN_DECL is as for tsubst. If
11182 ENTERING_SCOPE is nonzero, T is the context for a template which
11183 we are presently tsubst'ing. Return the substituted value. */
11185 static tree
11187 tree args,
11188 tsubst_flags_t complain,
11189 tree in_decl,
11191 {
11196 {
11201 /* Else fall through. */
11205 {
11206 tree argvec;
11207 tree context;
11208 tree r;
11212 /* In "sizeof(X<I>)" we need to evaluate "I". */
11218 /* First, determine the context for the type we are looking
11219 up. */
11222 {
11225 /* If context is a nested class inside a class template,
11226 it may still need to be instantiated (c++/33959). */
11228 }
11230 /* Then, figure out what arguments are appropriate for the
11231 type we are trying to find. For example, given:
11233 template <class T> struct S;
11234 template <class T, class U> void f(T, U) { S<U> su; }
11236 and supposing that we are instantiating f<int, double>,
11237 then our ARGS will be {int, double}, but, when looking up
11238 S we only want {double}. */
11243 else
11244 {
11248 }
11254 }
11255 else
11256 /* This is not a template type, so there's nothing to do. */
11261 }
11262 }
11264 /* Substitute into the default argument ARG (a default argument for
11265 FN), which has the indicated TYPE. */
11267 tree
11269 {
11274 /* This can happen in invalid code. */
11278 /* This default argument came from a template. Instantiate the
11279 default argument here, not in tsubst. In the case of
11280 something like:
11282 template <class T>
11283 struct S {
11284 static T t();
11285 void f(T = t());
11286 };
11288 we must be careful to do name lookup in the scope of S<T>,
11289 rather than in the current class. */
11291 /* The "this" pointer is not valid in a default argument. */
11293 {
11298 }
11301 /* The default argument expression may cause implicitly defined
11302 member functions to be synthesized, which will result in garbage
11303 collection. We must treat this situation as if we were within
11304 the body of function so as to avoid collecting live data on the
11305 stack. */
11313 /* Restore the "this" pointer. */
11315 {
11318 }
11325 /* Make sure the default argument is reasonable. */
11331 }
11333 /* Substitute into all the default arguments for FN. */
11335 static void
11337 {
11338 tree arg;
11339 tree tmpl_args;
11343 /* If this function is not yet instantiated, we certainly don't need
11344 its default arguments. */
11347 /* Don't do this again for clones. */
11352 arg;
11358 complain);
11359 }
11361 /* Substitute the ARGS into the T, which is a _DECL. Return the
11362 result of the substitution. Issue error and warning messages under
11363 control of COMPLAIN. */
11365 static tree
11367 {
11368 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
11369 location_t saved_loc;
11374 /* Set the filename and linenumber to improve error-reporting. */
11379 {
11381 {
11382 /* We can get here when processing a member function template,
11383 member class template, or template template parameter. */
11385 tree spec;
11386 tree tmpl_args;
11387 tree full_args;
11390 {
11391 /* Template template parameter is treated here. */
11395 /* If we get a real template back, return it. This can happen in
11396 the context of most_specialized_partial_spec. */
11399 else
11400 /* The new TEMPLATE_DECL was built in
11401 reduce_template_parm_level. */
11404 }
11406 /* We might already have an instance of this template.
11407 The ARGS are for the surrounding class type, so the
11408 full args contain the tsubst'd args for the context,
11409 plus the innermost args from the template decl. */
11413 /* Because this is a template, the arguments will still be
11414 dependent, even after substitution. If
11415 PROCESSING_TEMPLATE_DECL is not set, the dependency
11416 predicates will short-circuit. */
11424 /* If this is a default template template argument,
11425 tsubst might not have changed anything. */
11432 {
11435 }
11437 /* Make a new template decl. It will be similar to the
11438 original, but will record the current template arguments.
11439 We also create a new function declaration, which is just
11440 like the old one, but points to this new template, rather
11441 than the old one. */
11446 // Build new template info linking to the original template decl.
11451 {
11452 tree new_type;
11460 /* For a partial specialization, we need to keep pointing to
11461 the primary template. */
11467 }
11468 else
11469 {
11470 tree new_decl;
11482 }
11488 /* The template parameters for this new template are all the
11489 template parameters for the old template, except the
11490 outermost level of parameters. */
11493 complain);
11499 /* Record this non-type partial instantiation. */
11503 }
11507 {
11508 tree ctx;
11511 tree gen_tmpl;
11512 tree type;
11517 /* Nobody should be tsubst'ing into non-template functions. */
11521 {
11522 tree spec;
11525 /* If T is not dependent, just return it. We have to
11526 increment PROCESSING_TEMPLATE_DECL because
11527 value_dependent_expression_p assumes that nothing is
11528 dependent when PROCESSING_TEMPLATE_DECL is zero. */
11535 /* Calculate the most general template of which R is a
11536 specialization, and the complete set of arguments used to
11537 specialize R. */
11540 (DECL_TEMPLATE_RESULT
11546 /* Check to see if we already have this specialization. */
11551 {
11554 }
11556 /* We can see more levels of arguments than parameters if
11557 there was a specialization of a member template, like
11558 this:
11560 template <class T> struct S { template <class U> void f(); }
11561 template <> template <class U> void S<int>::f(U);
11563 Here, we'll be substituting into the specialization,
11564 because that's where we can find the code we actually
11565 want to generate, but we'll have enough arguments for
11566 the most general template.
11568 We also deal with the peculiar case:
11570 template <class T> struct S {
11571 template <class U> friend void f();
11572 };
11573 template <class U> void f() {}
11574 template S<int>;
11575 template void f<double>();
11577 Here, the ARGS for the instantiation of will be {int,
11578 double}. But, we only need as many ARGS as there are
11579 levels of template parameters in CODE_PATTERN. We are
11580 careful not to get fooled into reducing the ARGS in
11581 situations like:
11583 template <class T> struct S { template <class U> void f(U); }
11584 template <class T> template <> void S<T>::f(int) {}
11586 which we can spot because the pattern will be a
11587 specialization in this case. */
11589 parms_depth =
11594 }
11595 else
11596 {
11597 /* This special case arises when we have something like this:
11599 template <class T> struct S {
11600 friend void f<int>(int, double);
11601 };
11603 Here, the DECL_TI_TEMPLATE for the friend declaration
11604 will be an IDENTIFIER_NODE. We are being called from
11605 tsubst_friend_function, and we want only to create a
11606 new decl (R) with appropriate types so that we can call
11607 determine_specialization. */
11609 }
11612 {
11615 else
11619 }
11620 else
11621 {
11624 }
11629 /* If we hit excessive deduction depth, the type is bogus even if
11630 it isn't error_mark_node, so don't build a decl. */
11634 /* We do NOT check for matching decls pushed separately at this
11635 point, as they may not represent instantiations of this
11636 template, and in any case are considered separate under the
11637 discrete model. */
11641 /* Clear out the mangled name and RTL for the instantiation. */
11644 /* Leave DECL_INITIAL set on deleted instantiations. */
11649 /* OpenMP UDRs have the only argument a reference to the declared
11650 type. We want to diagnose if the declared type is a reference,
11651 which is invalid, but as references to references are usually
11652 quietly merged, diagnose it here. */
11654 {
11655 tree argtype
11660 "reference type %qT in "
11664 argtype);
11665 }
11668 /* Type-conversion operator. Reconstruct the name, in
11669 case it's the name of one of the template's parameters. */
11679 /* If this is an instantiation of a function with internal
11680 linkage, we already know what object file linkage will be
11681 assigned to the instantiation. */
11690 /* We'll re-clone as appropriate in instantiate_template. */
11693 /* If we aren't complaining now, return on error before we register
11694 the specialization so that we'll complain eventually. */
11700 /* When instantiating a constrained member, substitute
11701 into the constraints to create a new constraint. */
11704 {
11707 }
11709 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
11710 this in the special friend case mentioned above where
11711 GEN_TMPL is NULL. */
11713 {
11718 tree new_r
11721 /* We instantiated this while substituting into
11722 the type earlier (template/friend54.C). */
11725 /* We're not supposed to instantiate default arguments
11726 until they are called, for a template. But, for a
11727 declaration like:
11729 template <class T> void f ()
11730 { extern void g(int i = T()); }
11732 we should do the substitution when the template is
11733 instantiated. We handle the member function case in
11734 instantiate_class_template since the default arguments
11735 might refer to other members of the class. */
11740 }
11741 else
11744 /* Copy the list of befriending classes. */
11748 {
11752 in_decl);
11753 }
11756 {
11762 /* If this is an instantiation of a member template, clone it.
11763 If it isn't, that'll be handled by
11764 clone_constructors_and_destructors. */
11767 }
11778 /* Possibly limit visibility based on template args. */
11781 {
11785 }
11793 }
11797 {
11805 {
11806 /* If there is a local specialization that isn't a
11807 parameter pack, it means that we're doing a "simple"
11808 substitution from inside tsubst_pack_expansion. Just
11809 return the local specialization (which will be a single
11810 parm). */
11817 /* Expand the TYPE_PACK_EXPANSION that provides the types for
11818 the parameters in this function parameter pack. */
11822 {
11825 /* Zero-length parameter packs are boring. Just substitute
11826 into the chain. */
11830 }
11831 else
11832 {
11833 /* All we did was update the type. Make a note of that. */
11836 }
11837 }
11839 /* Loop through all of the parameters we'll build. When T is
11840 a function parameter pack, LEN is the number of expanded
11841 types in EXPANDED_TYPES; otherwise, LEN is 1. */
11844 {
11851 /* We're on the Ith parameter of the function parameter
11852 pack. */
11853 {
11854 /* Get the Ith type. */
11857 /* Rename the parameter to include the index. */
11860 }
11862 /* We're dealing with a normal parameter. */
11870 {
11873 else
11876 }
11886 /* Keep track of the first new parameter we
11887 generate. That's what will be returned to the
11888 caller. */
11892 /* Build a proper chain of parameters when substituting
11893 into a function parameter pack. */
11896 }
11898 /* If cp_unevaluated_operand is set, we're just looking for a
11899 single dummy parameter, so don't keep going. */
11904 /* FIRST_R contains the start of the chain we've built. */
11906 }
11910 {
11917 {
11918 /* This field is a lambda capture pack. Return a TREE_VEC of
11919 the expanded fields to instantiate_class_template_1 and
11920 store them in the specializations hash table as a
11921 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
11925 {
11928 }
11929 else
11930 {
11931 /* All we did was update the type. Make a note of that. */
11934 }
11935 }
11938 {
11941 {
11945 }
11955 /* For bit-fields, DECL_INITIAL gives the number of bits. For
11956 non-bit-fields DECL_INITIAL is a non-static data member
11957 initializer, which gets deferred instantiation. */
11963 {
11964 /* Set up DECL_TEMPLATE_INFO so that we can get at the
11965 NSDMI in perform_member_init. Still set DECL_INITIAL
11966 so that we know there is one. */
11971 }
11972 /* We don't have to set DECL_CONTEXT here; it is set by
11973 finish_member_declaration. */
11981 }
11984 {
11992 }
11993 }
11997 /* We reach here only for member using decls. We also need to check
11998 uses_template_parms because DECL_DEPENDENT_P is not set for a
11999 using-declaration that designates a member of the current
12000 instantiation (c++/53549). */
12003 {
12010 else
12011 {
12014 }
12015 }
12016 else
12017 {
12020 }
12025 {
12028 tree spec;
12030 tree ctx;
12039 {
12040 /* If this is the canonical decl, we don't have to
12041 mess with instantiations, and often we can't (for
12042 typename, template type parms and such). Note that
12043 TYPE_NAME is not correct for the above test if
12044 we've copied the type for a typedef. */
12050 }
12052 /* Check to see if we already have the specialization we
12053 need. */
12056 {
12057 /* T is a static data member or namespace-scope entity.
12058 We have to substitute into namespace-scope variables
12059 (not just variable templates) because of cases like:
12061 template <class T> void f() { extern T t; }
12063 where the entity referenced is not known until
12064 instantiation time. */
12068 {
12070 complain,
12072 /* If CTX is unchanged, then T is in fact the
12073 specialization we want. That situation occurs when
12074 referencing a static data member within in its own
12075 class. We can use pointer equality, rather than
12076 same_type_p, because DECL_CONTEXT is always
12077 canonical... */
12079 /* ... unless T is a member template; in which
12080 case our caller can be willing to create a
12081 specialization of that template represented
12082 by T. */
12086 }
12089 {
12094 argvec = (coerce_innermost_template_parms
12102 }
12103 }
12104 else
12105 {
12106 /* A local variable. */
12108 /* Subsequent calls to pushdecl will fill this in. */
12111 }
12112 /* If we already have the specialization we need, there is
12113 nothing more to do. */
12115 {
12118 }
12120 /* Create a new node for the specialization we need. */
12123 {
12126 else
12133 }
12135 {
12136 /* Even if the original location is out of scope, the
12137 newly substituted one is not. */
12144 {
12145 /* It may seem that this case cannot occur, since:
12147 typedef void f();
12148 void g() { f x; }
12150 declares a function, not a variable. However:
12152 typedef void f();
12153 template <typename T> void g() { T t; }
12154 template void g<f>();
12156 is an attempt to declare a variable with function
12157 type. */
12159 /* R is not yet sufficiently initialized, so we
12160 just use its name. */
12163 }
12165 /* Wait until cp_finish_decl to set this again, to handle
12166 circular dependency (template/instantiate6.C). */
12171 {
12176 {
12179 }
12181 }
12185 }
12191 /* Clear out the mangled name and RTL for the instantiation. */
12195 /* The initializer must not be expanded until it is required;
12196 see [temp.inst]. */
12202 {
12203 /* Possibly limit visibility based on template args. */
12206 {
12210 }
12212 }
12215 {
12216 /* A static data member declaration is always marked
12217 external when it is declared in-class, even if an
12218 initializer is present. We mimic the non-template
12219 processing here. */
12227 }
12237 /* Preserve a typedef that names a type. */
12239 {
12243 /* An alias template specialization can be dependent
12244 even if its underlying type is not. */
12246 }
12249 }
12254 }
12255 #undef RETURN
12257 out:
12258 /* Restore the file and line information. */
12262 }
12264 /* Substitute into the ARG_TYPES of a function type.
12265 If END is a TREE_CHAIN, leave it and any following types
12266 un-substituted. */
12268 static tree
12270 tree args,
12271 tree end,
12272 tsubst_flags_t complain,
12273 tree in_decl)
12274 {
12275 tree remaining_arg_types;
12279 tree default_arg;
12290 {
12291 /* For a pack expansion, perform substitution on the
12292 entire expression. Later on, we'll handle the arguments
12293 one-by-one. */
12298 /* So that we'll spin through the parameters, one by one. */
12300 else
12301 {
12302 /* We only partially substituted into the parameter
12303 pack. Our type is TYPE_PACK_EXPANSION. */
12306 }
12307 }
12320 {
12322 {
12326 }
12328 }
12329 /* DR 657. */
12333 /* Do array-to-pointer, function-to-pointer conversion, and ignore
12334 top-level qualifiers as required. */
12337 /* We do not substitute into default arguments here. The standard
12338 mandates that they be instantiated only when needed, which is
12339 done in build_over_call. */
12343 {
12344 /* We've instantiated a template before its default arguments
12345 have been parsed. This can happen for a nested template
12346 class, and is not an error unless we require the default
12347 argument in a call of this function. */
12348 remaining_arg_types =
12351 }
12352 else
12353 remaining_arg_types =
12355 }
12358 }
12360 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
12361 *not* handle the exception-specification for FNTYPE, because the
12362 initial substitution of explicitly provided template parameters
12363 during argument deduction forbids substitution into the
12364 exception-specification:
12366 [temp.deduct]
12368 All references in the function type of the function template to the
12369 corresponding template parameters are replaced by the specified tem-
12370 plate argument values. If a substitution in a template parameter or
12371 in the function type of the function template results in an invalid
12372 type, type deduction fails. [Note: The equivalent substitution in
12373 exception specifications is done only when the function is instanti-
12374 ated, at which point a program is ill-formed if the substitution
12375 results in an invalid type.] */
12377 static tree
12379 tree args,
12380 tsubst_flags_t complain,
12381 tree in_decl)
12382 {
12383 tree return_type;
12385 tree fntype;
12387 /* The TYPE_CONTEXT is not used for function/method types. */
12390 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
12391 failure. */
12395 {
12396 /* Substitute the argument types. */
12408 {
12409 /* DR 1207: 'this' is in scope in the trailing return type. */
12411 }
12413 /* Substitute the return type. */
12417 {
12420 }
12421 }
12422 else
12423 /* Substitute the return type. */
12428 /* DR 486 clarifies that creation of a function type with an
12429 invalid return type is a deduction failure. */
12432 {
12434 {
12437 else
12439 }
12441 }
12442 /* And DR 657. */
12447 {
12448 /* Substitute the argument types. */
12453 }
12455 /* Construct a new type node and return it. */
12457 {
12462 }
12463 else
12464 {
12466 /* Don't pick up extra function qualifiers from the basetype. */
12469 {
12470 /* [temp.deduct]
12472 Type deduction may fail for any of the following
12473 reasons:
12475 -- Attempting to create "pointer to member of T" when T
12476 is not a class type. */
12479 r);
12481 }
12486 }
12493 }
12495 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
12496 ARGS into that specification, and return the substituted
12497 specification. If there is no specification, return NULL_TREE. */
12499 static tree
12501 tree args,
12502 tsubst_flags_t complain,
12503 tree in_decl,
12505 {
12506 tree specs;
12507 tree new_specs;
12512 {
12513 /* A noexcept-specifier. */
12518 {
12519 /* Defer instantiation of noexcept-specifiers to avoid
12520 excessive instantiations (c++/49107). */
12523 {
12524 /* We already partially instantiated this member template,
12525 so combine the new args with the old. */
12530 }
12531 else
12532 {
12535 }
12536 }
12537 else
12538 new_specs = tsubst_copy_and_build
12542 }
12544 {
12547 else
12549 {
12550 tree spec;
12555 {
12556 /* Expand the pack expansion type. */
12559 in_decl);
12565 else
12566 {
12567 /* We're substituting into a member template, so
12568 we got a TYPE_PACK_EXPANSION back. Add that
12569 expansion and move on. */
12573 expanded_specs,
12574 complain);
12577 }
12578 }
12581 {
12584 else
12589 complain);
12590 }
12593 }
12594 }
12596 }
12598 /* Take the tree structure T and replace template parameters used
12599 therein with the argument vector ARGS. IN_DECL is an associated
12600 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
12601 Issue error and warning messages under control of COMPLAIN. Note
12602 that we must be relatively non-tolerant of extensions here, in
12603 order to preserve conformance; if we allow substitutions that
12604 should not be allowed, we may allow argument deductions that should
12605 not succeed, and therefore report ambiguous overload situations
12606 where there are none. In theory, we could allow the substitution,
12607 but indicate that it should have failed, and allow our caller to
12608 make sure that the right thing happens, but we don't try to do this
12609 yet.
12611 This function is used for dealing with types, decls and the like;
12612 for expressions, use tsubst_expr or tsubst_copy. */
12614 tree
12616 {
12639 else
12644 /* Reuse typedefs. We need to do this to handle dependent attributes,
12645 such as attribute aligned. */
12648 {
12652 {
12653 /* DECL represents an alias template and we want to
12654 instantiate it. */
12658 }
12662 {
12666 }
12671 else
12672 /* The typedef is from a non-template context. */
12676 {
12678 r = cp_build_qualified_type_real
12682 }
12683 else
12684 {
12685 /* We don't have an instantiation yet, so drop the typedef. */
12690 }
12691 }
12704 {
12730 {
12736 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
12737 needed. */
12743 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
12744 with TREE_SIDE_EFFECTS that indicates this is not an integral
12745 constant expression. */
12748 {
12751 }
12754 }
12760 {
12766 /* Early in template argument deduction substitution, we don't
12767 want to reduce the level of 'auto', or it will be confused
12768 with a normal template parm in subsequent deduction. */
12780 {
12784 {
12785 /* See through ARGUMENT_PACK_SELECT arguments. */
12787 /* If the selected argument is an expansion E, that most
12788 likely means we were called from
12789 gen_elem_of_pack_expansion_instantiation during the
12790 substituting of pack an argument pack (which Ith
12791 element is a pack expansion, where I is
12792 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
12793 In this case, the Ith element resulting from this
12794 substituting is going to be a pack expansion, which
12795 pattern is the pattern of E. Let's return the
12796 pattern of E, and
12797 gen_elem_of_pack_expansion_instantiation will
12798 build the resulting pack expansion from it. */
12800 {
12801 /* Make sure we aren't throwing away arg info. */
12804 }
12805 }
12806 }
12811 {
12813 /* If ARG is an argument pack, we don't actually want to
12814 perform a substitution here, because substitutions
12815 for argument packs are only done
12816 element-by-element. We can get to this point when
12817 substituting the type of a non-type template
12818 parameter pack, when that type actually contains
12819 template parameter packs from an outer template, e.g.,
12821 template<typename... Types> struct A {
12822 template<Types... Values> struct B { };
12823 }; */
12827 {
12833 return cp_build_qualified_type_real
12835 }
12837 {
12838 /* We are processing a type constructed from a
12839 template template parameter. */
12850 /* Consider this code:
12852 template <template <class> class Template>
12853 struct Internal {
12854 template <class Arg> using Bind = Template<Arg>;
12855 };
12857 template <template <class> class Template, class Arg>
12858 using Instantiate = Template<Arg>; //#0
12860 template <template <class> class Template,
12861 class Argument>
12862 using Bind =
12863 Instantiate<Internal<Template>::template Bind,
12864 Argument>; //#1
12866 When #1 is parsed, the
12867 BOUND_TEMPLATE_TEMPLATE_PARM representing the
12868 parameter `Template' in #0 matches the
12869 UNBOUND_CLASS_TEMPLATE representing the argument
12870 `Internal<Template>::template Bind'; We then want
12871 to assemble the type `Bind<Argument>' that can't
12872 be fully created right now, because
12873 `Internal<Template>' not being complete, the Bind
12874 template cannot be looked up in that context. So
12875 we need to "store" `Bind<Argument>' for later
12876 when the context of Bind becomes complete. Let's
12877 store that in a TYPENAME_TYPE. */
12881 argvec),
12882 typename_type,
12883 complain);
12885 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
12886 are resolving nested-types in the signature of a
12887 member function templates. Otherwise ARG is a
12888 TEMPLATE_DECL and is the real template to be
12889 instantiated. */
12897 complain);
12898 return cp_build_qualified_type_real
12900 }
12901 else
12902 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
12904 }
12907 /* This can happen during the attempted tsubst'ing in
12908 unify. This means that we don't yet have any information
12909 about the template parameter in question. */
12912 /* If we get here, we must have been looking at a parm for a
12913 more deeply nested template. Make a new version of this
12914 template parameter, but with a lower level. */
12916 {
12921 {
12923 r = cp_build_qualified_type_real
12927 }
12934 /* Break infinite recursion when substituting the constraints
12936 else
12937 {
12948 /* We have reduced the level of the template
12949 template parameter, but not the levels of its
12950 template parameters, so canonical_type_parameter
12951 will not be able to find the canonical template
12952 template parameter for this level. Thus, we
12953 require structural equality checking to compare
12954 TEMPLATE_TEMPLATE_PARMs. */
12958 else
12961 /* Propagate constraints on placeholders. */
12968 {
12976 }
12977 }
12986 }
12989 }
12992 {
13000 {
13004 }
13007 {
13011 }
13014 {
13018 }
13024 }
13027 /* We should never be tsubsting a binfo. */
13031 /* A vector of template arguments. */
13037 {
13041 /* [temp.deduct]
13043 Type deduction may fail for any of the following
13044 reasons:
13046 -- Attempting to create a pointer to reference type.
13047 -- Attempting to create a reference to a reference type or
13048 a reference to void.
13050 Core issue 106 says that creating a reference to a reference
13051 during instantiation is no longer a cause for failure. We
13052 only enforce this check in strict C++98 mode. */
13056 {
13059 /* We keep track of the last time we issued this error
13060 message to avoid spewing a ton of messages during a
13061 single bad template instantiation. */
13064 {
13069 else
13072 }
13075 }
13079 {
13081 {
13084 type);
13085 else
13087 type);
13088 }
13090 }
13092 {
13096 }
13098 /* In C++0x, during template argument substitution, when there is an
13099 attempt to create a reference to a reference type, reference
13100 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13102 "If a template-argument for a template-parameter T names a type
13103 that is a reference to a type A, an attempt to create the type
13104 'lvalue reference to cv T' creates the type 'lvalue reference to
13105 A,' while an attempt to create the type type rvalue reference to
13106 cv T' creates the type T"
13107 */
13108 r = cp_build_reference_type
13111 else
13116 /* Will this ever be needed for TYPE_..._TO values? */
13120 }
13122 {
13125 {
13126 /* [temp.deduct]
13128 Type deduction may fail for any of the following
13129 reasons:
13131 -- Attempting to create "pointer to member of T" when T
13132 is not a class type. */
13136 }
13138 {
13142 }
13144 {
13148 }
13151 {
13152 /* The type of the implicit object parameter gets its
13153 cv-qualifiers from the FUNCTION_TYPE. */
13154 tree memptr;
13155 tree method_type
13160 complain);
13161 }
13162 else
13165 complain);
13166 }
13169 {
13170 tree fntype;
13171 tree specs;
13176 /* Substitute the exception specification. */
13184 }
13186 {
13191 /* As an optimization, we avoid regenerating the array type if
13192 it will obviously be the same as T. */
13196 /* These checks should match the ones in create_array_type_for_decl.
13198 [temp.deduct]
13200 The deduction may fail for any of the following reasons:
13202 -- Attempting to create an array with an element type that
13203 is void, a function type, or a reference type, or [DR337]
13204 an abstract class type. */
13210 {
13214 }
13222 {
13225 }
13228 }
13231 {
13241 {
13245 }
13247 {
13248 /* Normally, make_typename_type does not require that the CTX
13249 have complete type in order to allow things like:
13251 template <class T> struct S { typename S<T>::X Y; };
13253 But, such constructs have already been resolved by this
13254 point, so here CTX really should have complete type, unless
13255 it's a partial instantiation. */
13258 {
13262 }
13263 }
13270 {
13273 }
13276 {
13278 {
13282 else
13284 }
13286 {
13290 else
13292 }
13293 }
13295 return cp_build_qualified_type_real
13297 }
13300 {
13312 }
13315 {
13316 tree type;
13332 complain);
13333 }
13336 {
13337 tree type;
13355 else
13356 {
13360 /* In a template ~id could be either a complement expression
13361 or an unqualified-id naming a destructor; if instantiating
13362 it produces an expression, it's not an id-expression or
13363 member access. */
13366 }
13371 }
13374 {
13378 }
13382 {
13384 tree packed_out =
13386 args,
13387 complain,
13388 in_decl);
13391 /* For template nontype argument packs, also substitute into
13392 the type. */
13397 }
13413 /* We should use one of the expression tsubsts for these codes. */
13419 }
13420 }
13422 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
13423 type of the expression on the left-hand side of the "." or "->"
13424 operator. */
13426 static tree
13429 {
13430 tree name;
13431 tree qualifying_scope;
13432 tree fns;
13433 tree optype;
13438 /* A baselink indicates a function from a base class. Both the
13439 BASELINK_ACCESS_BINFO and the base class referenced may
13440 indicate bases of the template class, rather than the
13441 instantiated class. In addition, lookups that were not
13442 ambiguous before may be ambiguous now. Therefore, we perform
13443 the lookup again. */
13450 {
13457 }
13465 /* If lookup found a single function, mark it as used at this
13466 point. (If it lookup found multiple functions the one selected
13467 later by overload resolution will be marked as used at that
13468 point.) */
13475 /* Add back the template arguments, if present. */
13480 template_args);
13481 /* Update the conversion operator type. */
13489 qualifying_scope,
13490 object_type);
13492 }
13494 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
13495 true if the qualified-id will be a postfix-expression in-and-of
13496 itself; false if more of the postfix-expression follows the
13497 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
13498 of "&". */
13500 static tree
13504 {
13505 tree expr;
13506 tree scope;
13507 tree name;
13509 tree template_args;
13514 /* Figure out what name to look up. */
13517 {
13525 }
13526 else
13527 {
13530 }
13532 /* Substitute into the qualifying scope. When there are no ARGS, we
13533 are just trying to simplify a non-dependent expression. In that
13534 case the qualifying scope may be dependent, and, in any case,
13535 substituting will not help. */
13538 {
13541 }
13542 else
13546 {
13551 }
13554 {
13556 {
13557 /* A BIT_NOT_EXPR is used to represent a destructor. */
13559 {
13563 }
13564 else
13567 }
13568 else
13572 {
13574 {
13578 }
13580 }
13581 }
13584 {
13586 scope);
13587 /* Remember that there was a reference to this entity. */
13590 }
13593 {
13599 }
13608 {
13609 expr = (adjust_result_of_qualified_name_lookup
13611 expr = (finish_qualified_id_expr
13615 }
13617 /* Expressions do not generally have reference type. */
13619 /* However, if we're about to form a pointer-to-member, we just
13620 want the referenced member referenced. */
13625 }
13627 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
13628 initializer, DECL is the substituted VAR_DECL. Other arguments are as
13629 for tsubst. */
13631 static tree
13634 {
13641 {
13642 /* If we had an initializer but it
13643 instantiated to nothing,
13644 value-initialize the object. This will
13645 only occur when the initializer was a
13646 pack expansion where the parameter packs
13647 used in that expansion were of length
13648 zero. */
13650 complain);
13653 }
13656 }
13658 /* Like tsubst, but deals with expressions. This function just replaces
13659 template parms; to finish processing the resultant expression, use
13660 tsubst_copy_and_build or tsubst_expr. */
13662 static tree
13664 {
13666 tree r;
13674 {
13679 {
13680 /* We get here for a use of 'this' in an NSDMI. */
13682 && current_function_decl
13686 /* This can happen for a parameter name used later in a function
13687 declaration (such as in a late-specified return type). Just
13688 make a dummy decl, since it's only used for its type. */
13691 /* Give it the template pattern as its context; its true context
13692 hasn't been instantiated yet and this is good enough for
13693 mangling. */
13695 }
13704 {
13705 tree enum_type;
13706 tree v;
13710 /* There is no need to substitute into namespace-scope
13711 enumerators. */
13714 /* If ARGS is NULL, then T is known to be non-dependent. */
13718 /* Unfortunately, we cannot just call lookup_name here.
13719 Consider:
13721 template <int I> int f() {
13722 enum E { a = I };
13723 struct S { void g() { E e = a; } };
13724 };
13726 When we instantiate f<7>::S::g(), say, lookup_name is not
13727 clever enough to find f<7>::a. */
13728 enum_type
13738 /* We didn't find the name. That should never happen; if
13739 name-lookup found it during preliminary parsing, we
13740 should find it again here during instantiation. */
13742 }
13747 {
13748 /* Check for a local specialization set up by
13749 tsubst_pack_expansion. */
13751 {
13755 }
13757 /* When retrieving a capture pack from a generic lambda, remove the
13758 lambda call op's own template argument list from ARGS. Only the
13759 template arguments active for the closure type should be used to
13760 retrieve the pack specialization. */
13766 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
13767 tsubst_decl put in the hash table. */
13769 }
13772 {
13773 tree ctx;
13778 {
13781 {
13785 }
13787 }
13788 }
13797 {
13800 {
13801 /* First try name lookup to find the instantiation. */
13804 {
13805 /* Make sure that the one we found is the one we want. */
13811 }
13815 else
13816 {
13817 /* This can happen for a variable used in a
13818 late-specified return type of a local lambda, or for a
13819 local static or constant. Building a new VAR_DECL
13820 should be OK in all those cases. */
13823 {
13824 /* We can't call cp_finish_decl, so handle the
13825 initializer by hand. */
13836 }
13841 {
13844 at_eof);
13845 else
13847 }
13848 }
13849 /* Remember this for subsequent uses. */
13852 }
13853 }
13854 else
13864 /* An OVERLOAD will always be a non-dependent overload set; an
13865 overload set from function scope will just be represented with an
13866 IDENTIFIER_NODE, and from class scope with a BASELINK. */
13882 {
13883 /* Template template argument like the following example need
13884 special treatment:
13886 template <template <class> class TT> struct C {};
13887 template <class T> struct D {
13888 template <class U> struct E {};
13889 C<E> c; // #1
13890 };
13891 D<int> d; // #2
13893 We are processing the template argument `E' in #1 for
13894 the template instantiation #2. Originally, `E' is a
13895 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
13896 have to substitute this with one having context `D<int>'. */
13900 }
13901 else
13902 /* Ordinary template template argument. */
13913 {
13917 }
13921 {
13931 /* We only want to compute the number of arguments. */
13945 {
13952 else
13955 }
13956 else
13958 }
13960 {
13968 }
13969 /* Fall through */
13985 {
13989 }
13992 {
13993 tree object;
13994 tree name;
13999 {
14003 }
14006 {
14016 }
14021 in_decl);
14022 else
14025 }
14063 {
14067 }
14070 {
14075 }
14078 {
14082 }
14085 {
14093 }
14099 {
14106 }
14109 {
14116 }
14119 {
14126 }
14129 {
14130 /* Substituted template arguments */
14139 }
14142 {
14162 }
14187 /* Fall through. */
14190 {
14193 }
14194 else
14198 /* This is handled by tsubst_copy_and_build. */
14202 {
14206 }
14209 /* We shouldn't have built any of these during initial template
14210 generation. Instead, they should be built during instantiation
14211 in response to the saved STMT_IS_FULL_EXPR_P setting. */
14215 {
14225 }
14243 {
14244 /* Instantiate any typedefs in the type. */
14249 }
14252 /* These can sometimes show up in a partial instantiation, but never
14253 involve template parms. */
14267 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
14270 }
14271 }
14273 /* Helper function for tsubst_omp_clauses, used for instantiation of
14274 OMP_CLAUSE_DECL of clauses that handles also OpenMP array sections
14275 represented with TREE_LIST. */
14277 static tree
14279 tree in_decl)
14280 {
14282 {
14283 tree low_bound
14289 in_decl);
14295 }
14297 }
14299 /* Like tsubst_copy, but specifically for OpenMP clauses. */
14301 static tree
14304 {
14308 {
14314 {
14317 {
14323 }
14324 /* FALLTHRU */
14340 in_decl);
14359 {
14362 {
14369 }
14370 else
14372 }
14399 }
14400 }
14406 }
14408 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
14410 static tree
14412 tree in_decl)
14413 {
14414 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
14434 {
14437 else
14438 {
14442 }
14443 }
14448 #undef RECUR
14449 }
14451 /* Substitute one OMP_FOR iterator. */
14453 static void
14458 {
14459 #define RECUR(NODE) \
14460 tsubst_expr ((NODE), args, complain, in_decl, \
14461 integral_constant_expression_p)
14470 {
14471 /* We need to jump through some hoops to handle declarations in the
14472 for-init-statement, since we might need to handle auto deduction,
14473 but we need to keep control of initialization. */
14477 }
14478 else
14490 {
14492 {
14493 /* Declare the variable, but don't let that initialize it. */
14498 }
14503 {
14508 }
14509 else
14516 }
14519 {
14520 /* Declare and initialize the variable. */
14523 }
14525 {
14526 tree c;
14528 {
14539 }
14541 {
14546 {
14549 }
14550 }
14551 }
14554 {
14558 }
14559 else
14563 {
14574 {
14582 }
14583 else
14589 {
14595 }
14599 {
14607 }
14608 else
14614 }
14620 #undef RECUR
14621 }
14623 /* Like tsubst_copy for expressions, etc. but also does semantic
14624 processing. */
14626 tree
14629 {
14630 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
14631 #define RECUR(NODE) \
14632 tsubst_expr ((NODE), args, complain, in_decl, \
14633 integral_constant_expression_p)
14636 tree r;
14637 location_t loc;
14649 {
14651 {
14652 tree_stmt_iterator i;
14656 }
14671 else
14680 {
14682 tree init;
14688 {
14691 tree decl;
14699 else
14701 }
14703 {
14704 /* Don't build up decls for a variadic capture proxy, we'll
14705 instantiate the elements directly as needed. */
14707 }
14708 else
14709 {
14713 {
14714 /* By marking the declaration as instantiated, we avoid
14715 trying to instantiate it. Since instantiate_decl can't
14716 handle local variables, and since we've already done
14717 all that needs to be done, that's the right thing to
14718 do. */
14723 /* Anonymous aggregates are a special case. */
14726 {
14729 {
14733 }
14735 }
14741 {
14746 }
14747 else
14748 {
14753 {
14754 /* For __PRETTY_FUNCTION__ we have to adjust the
14755 initializer. */
14759 }
14760 else
14764 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
14767 }
14768 }
14769 }
14772 }
14787 {
14797 }
14824 {
14828 }
14836 else
14844 else
14865 {
14869 }
14873 {
14875 tree label;
14880 }
14886 /* Computed goto's must be tsubst'd into. On the other hand,
14887 non-computed gotos must not be; the identifier in question
14888 will have no binding. */
14890 else
14896 {
14912 }
14917 {
14922 }
14923 else
14924 {
14929 else
14936 else
14942 else
14944 }
14948 {
14952 {
14954 /* Prevent instantiate_decl from trying to instantiate
14955 this variable. We've already done all that needs to be
14956 done. */
14959 }
14964 }
14970 {
14971 /* Local classes are not independent templates; they are
14972 instantiated along with their containing function. And this
14973 way we don't have to deal with pushing out of one local class
14974 to instantiate a member of another local class. */
14975 tree fn;
14976 /* Closures are handled by the LAMBDA_EXPR. */
14982 }
14986 {
14987 tree condition;
14990 condition =
14992 args,
15001 }
15026 {
15035 {
15040 }
15052 integral_constant_expression_p);
15061 else
15062 {
15070 }
15073 }
15132 {
15137 {
15140 }
15146 }
15147 else
15148 {
15155 {
15158 }
15161 {
15166 {
15169 }
15175 }
15176 else
15177 {
15181 }
15184 }
15188 {
15194 {
15198 {
15203 }
15207 }
15208 else
15209 {
15214 }
15215 }
15219 {
15223 }
15243 /* If the first operand was a statement, we're done with it. */
15247 complain));
15259 integral_constant_expression_p));
15260 }
15263 out:
15266 #undef RECUR
15267 #undef RETURN
15268 }
15270 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
15271 function. For description of the body see comment above
15272 cp_parser_omp_declare_reduction_exprs. */
15274 static void
15276 {
15282 tree_stmt_iterator tsi;
15293 {
15312 }
15314 {
15334 }
15335 }
15337 /* T is a postfix-expression that is not being used in a function
15338 call. Return the substituted version of T. */
15340 static tree
15342 tsubst_flags_t complain,
15343 tree in_decl)
15344 {
15348 else
15354 }
15356 /* Like tsubst but deals with expressions and performs semantic
15357 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
15359 tree
15361 tree args,
15362 tsubst_flags_t complain,
15363 tree in_decl,
15366 {
15367 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
15368 #define RECUR(NODE) \
15369 tsubst_copy_and_build (NODE, args, complain, in_decl, \
15371 integral_constant_expression_p)
15374 location_t loc;
15383 /* N3276 decltype magic only applies to calls at the top level or on the
15384 right side of a comma. */
15389 {
15392 /* Fall through. */
15394 {
15395 tree decl;
15396 cp_id_kind idk;
15401 {
15404 }
15406 /* Look up the name. */
15409 /* By convention, expressions use ERROR_MARK_NODE to indicate
15410 failure, not NULL_TREE. */
15416 integral_constant_expression_p,
15424 input_location);
15428 {
15432 }
15434 }
15437 {
15438 tree object;
15448 {
15451 {
15454 }
15456 }
15459 {
15462 }
15463 else
15470 else
15472 }
15475 {
15479 {
15480 /* A type conversion to reference type will be enclosed in
15481 such an indirect ref, but the substitution of the cast
15482 will have also added such an indirect ref. */
15485 }
15486 else
15490 }
15493 {
15497 }
15500 {
15507 flags));
15508 }
15511 {
15515 }
15522 {
15523 tree type;
15529 {
15534 }
15540 {
15558 }
15561 }
15595 else
15597 in_decl);
15632 {
15639 tree r = build_x_binary_op
15641 op0,
15643 ? ERROR_MARK
15645 op1,
15647 ? ERROR_MARK
15655 }
15658 {
15662 }
15675 {
15684 }
15688 /* Fall through */
15691 {
15692 tree r;
15698 {
15699 /* When there are no ARGS, we are trying to evaluate a
15700 non-dependent expression from the parser. Trying to do
15701 the substitutions may not work. */
15704 }
15705 else
15706 {
15711 else
15714 /*integral_constant_expression_p=*/
15718 }
15722 else
15726 {
15728 {
15730 {
15734 }
15735 else
15739 }
15741 }
15743 }
15746 {
15756 }
15772 {
15776 tree r = build_x_modify_expr
15779 /* TREE_NO_WARNING must be set if either the expression was
15780 parenthesized or it uses an operator such as >>= rather
15781 than plain assignment. In the former case, it was already
15782 set and must be copied. In the latter case,
15783 build_x_modify_expr sets it and it must not be reset
15784 here. */
15789 }
15794 /* Remember that there was a reference to this entity. */
15801 {
15806 tree ret;
15810 else
15811 {
15815 }
15817 /* If there was an initializer in the original tree, but it
15818 instantiated to an empty list, then we should pass a
15819 non-NULL empty vector to tell build_new that it was an
15820 empty initializer() rather than no initializer. This can
15821 only happen when the initializer is a pack expansion whose
15822 parameter packs are of length zero. */
15825 else
15826 {
15830 else
15831 {
15834 }
15835 }
15841 complain);
15849 }
15852 {
15858 complain));
15859 }
15862 {
15866 integral_constant_expression_p);
15868 op0,
15871 }
15874 {
15875 tree function;
15880 tree ret;
15883 /* When we parsed the expression, we determined whether or
15884 not Koenig lookup should be performed. */
15887 {
15892 }
15894 {
15895 /* Do nothing; calling tsubst_copy_and_build on an identifier
15896 would incorrectly perform unqualified lookup again.
15898 Note that we can also have an IDENTIFIER_NODE if the earlier
15899 unqualified lookup found a member function; in that case
15900 koenig_p will be false and we do want to do the lookup
15901 again to find the instantiated member function.
15903 FIXME but doing that causes c++/15272, so we need to stop
15904 using IDENTIFIER_NODE in that situation. */
15906 }
15907 else
15908 {
15910 {
15916 }
15917 else
15922 /* Avoid error about taking the address of a constructor. */
15926 in_decl,
15928 integral_constant_expression_p);
15932 }
15937 {
15942 else
15943 {
15944 /* Expand the pack expansion and push each entry onto
15945 CALL_ARGS. */
15948 {
15953 {
15958 }
15959 }
15960 else
15961 {
15962 /* A partial substitution. Add one entry. */
15964 }
15965 }
15966 }
15968 /* We do not perform argument-dependent lookup if normal
15969 lookup finds a non-function, in accordance with the
15970 expected resolution of DR 218. */
15973 /* If lookup found a member function, the Koenig lookup is
15974 not appropriate, even if an unqualified-name was used
15975 to denote the function. */
15978 /* Only do this when substitution turns a dependent call
15979 into a non-dependent call. */
15986 {
15988 {
15989 /* For backwards compatibility and good diagnostics, try
15990 the unqualified lookup again if we aren't in SFINAE
15991 context. */
15992 tree unq = (tsubst_copy_and_build
15994 integral_constant_expression_p));
15999 {
16008 "%qD was not declared in this scope, "
16009 "and no declarations were found by "
16010 "argument-dependent lookup at the point "
16012 {
16016 {
16018 input_location);
16020 "declarations in dependent base %qT are "
16026 else
16030 }
16031 else
16033 "%qD declared here, later in the "
16035 }
16037 }
16038 }
16040 {
16045 }
16046 }
16048 /* Remember that there was a reference to this entity. */
16053 /* Put back tf_decltype for the actual call. */
16058 complain);
16060 {
16075 complain);
16076 else
16077 ret = (build_new_method_call
16082 complain));
16083 }
16084 else
16087 koenig_p,
16088 complain);
16093 }
16096 {
16102 {
16104 {
16109 }
16110 else
16111 {
16116 }
16118 }
16119 else
16120 {
16123 }
16127 }
16130 {
16135 input_location));
16136 }
16139 {
16147 {
16148 /* We have pack expansions, so expand those and
16149 create a new list out of it. */
16152 tree chain;
16155 /* Expand the argument expressions. */
16163 /* Build the rest of the list. */
16168 /* Determine the number of arguments. */
16170 {
16173 }
16176 else
16177 {
16178 /* Since we only performed a partial substitution into
16179 the argument pack, we only RETURN (a single list
16180 node. */
16187 }
16189 /* Convert the argument vectors into a TREE_LIST */
16192 {
16193 /* Grab the Ith values. */
16194 i--;
16197 value
16201 /* Build the list (backwards). */
16203 }
16206 }
16222 }
16225 {
16226 tree object;
16227 tree object_type;
16228 tree member;
16229 tree r;
16233 /* Remember that there was a reference to this entity. */
16244 else
16252 {
16254 {
16259 {
16262 }
16264 {
16269 }
16270 }
16271 }
16274 {
16275 /* Lookup the template functions now that we know what the
16276 scope is. */
16284 {
16287 args);
16288 member = (adjust_result_of_qualified_name_lookup
16290 object_type));
16291 }
16292 else
16293 {
16295 input_location);
16297 }
16298 }
16302 {
16304 {
16308 else
16311 }
16313 }
16315 {
16320 }
16324 complain);
16328 }
16335 {
16343 tree r;
16348 /* digest_init will do the wrong thing if we let it. */
16352 /* We do not want to process the index of aggregate
16353 initializers as they are identifier nodes which will be
16354 looked up by digest_init. */
16360 {
16362 /* An identifier index is looked up in the type
16363 being initialized, not the current scope. */
16368 {
16369 /* Substitute into the pack expansion. */
16371 in_decl);
16375 ;
16377 /* Just move the argument into place. */
16379 else
16380 {
16381 /* Update the length of the final CONSTRUCTOR
16382 arguments vector, and note that we will need to
16383 copy.*/
16386 }
16387 }
16388 else
16390 }
16393 {
16398 {
16400 {
16405 }
16406 else
16408 }
16409 }
16419 }
16422 {
16425 {
16428 }
16429 else
16430 {
16433 }
16434 }
16440 {
16441 /* We don't build decls for an instantiation of a
16442 variadic capture proxy, we instantiate the elements
16443 when needed. */
16446 }
16447 /* Fall through */
16450 {
16452 /* ??? We're doing a subset of finish_id_expression here. */
16454 && !processing_template_decl
16455 && !cp_unevaluated_operand
16458 {
16460 /* Replace an evaluated use of the thread_local variable with
16461 a call to its wrapper. */
16463 }
16465 {
16469 }
16472 /* If the original type was a reference, we'll be wrapped in
16473 the appropriate INDIRECT_REF. */
16476 }
16479 {
16483 }
16490 {
16501 }
16504 {
16510 integral_constant_expression_p);
16514 /* If the resulting list of expression statement is empty,
16515 fold it further into void_node. */
16520 }
16523 {
16541 /* For a function or variable scope, we want to use tsubst so that we
16542 don't complain about referring to an auto before deduction. */
16545 {
16546 /* Look up the parameter we want directly, as tsubst_copy
16547 doesn't do what we need. */
16553 /* FIXME Work around the parm not having DECL_CONTEXT set. */
16556 }
16558 /* For a field, use tsubst_copy so that we look up the existing field
16559 rather than build a new one. */
16561 else
16570 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
16572 /* Now that we know visibility, instantiate the type so we have a
16573 declaration of the op() for later calls to lambda_function. */
16581 }
16584 /* We can get here for a constant initializer of non-dependent type.
16585 FIXME stop folding in cp_parser_initializer_clause. */
16586 {
16588 complain);
16590 }
16594 integral_constant_expression_p));
16600 {
16605 complain));
16606 }
16612 /* Handle Objective-C++ constructs, if appropriate. */
16613 {
16614 tree subst
16619 }
16621 }
16623 #undef RECUR
16624 #undef RETURN
16625 out:
16628 }
16630 /* Verify that the instantiated ARGS are valid. For type arguments,
16631 make sure that the type's linkage is ok. For non-type arguments,
16632 make sure they are constants if they are integral or enumerations.
16633 Emit an error under control of COMPLAIN, and return TRUE on error. */
16635 static bool
16637 {
16641 {
16651 }
16653 {
16654 /* [basic.link]: A name with no linkage (notably, the name
16655 of a class or enumeration declared in a local scope)
16656 shall not be used to declare an entity with linkage.
16657 This implies that names with no linkage cannot be used as
16658 template arguments
16660 DR 757 relaxes this restriction for C++0x. */
16665 {
16666 /* DR 488 makes use of a type with no linkage cause
16667 type deduction to fail. */
16669 {
16672 else
16675 }
16677 }
16678 /* In order to avoid all sorts of complications, we do not
16679 allow variably-modified types as template arguments. */
16681 {
16685 }
16686 }
16687 /* Class template and alias template arguments should be OK. */
16689 ;
16690 /* A non-type argument of integral or enumerated type must be a
16691 constant. */
16696 {
16700 }
16702 }
16704 static bool
16706 {
16711 {
16714 }
16718 }
16720 /* We're out of SFINAE context now, so generate diagnostics for the access
16721 errors we saw earlier when instantiating D from TMPL and ARGS. */
16723 static void
16725 {
16737 }
16739 /* Instantiate the indicated variable, function, or alias template TMPL with
16740 the template arguments in TARG_PTR. */
16742 static tree
16744 {
16746 tree fndecl;
16747 tree gen_tmpl;
16748 tree spec;
16756 /* If this function is a clone, handle it specially. */
16758 {
16759 tree spec;
16760 tree clone;
16762 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
16763 DECL_CLONED_FUNCTION. */
16769 /* Look for the clone. */
16773 /* We should always have found the clone by now. */
16776 }
16781 /* Check to see if we already have this specialization. */
16784 /* The TMPL is a partial instantiation. To get a full set of
16785 arguments we must add the arguments used to perform the
16786 partial instantiation. */
16788 targ_ptr);
16790 /* It would be nice to avoid hashing here and then again in tsubst_decl,
16791 but it doesn't seem to be on the hot path. */
16800 {
16802 {
16806 }
16808 }
16811 complain))
16814 /* We are building a FUNCTION_DECL, during which the access of its
16815 parameters and return types have to be checked. However this
16816 FUNCTION_DECL which is the desired context for access checking
16817 is not built yet. We solve this chicken-and-egg problem by
16818 deferring all checks until we have the FUNCTION_DECL. */
16821 /* Instantiation of the function happens in the context of the function
16822 template, not the context of the overload resolution we're doing. */
16824 /* If there are dependent arguments, e.g. because we're doing partial
16825 ordering, make sure processing_template_decl stays set. */
16829 {
16833 }
16838 {
16839 /* We need to determine if we're using a partial or explicit
16840 specialization now, because the type of the variable could be
16841 different. */
16847 {
16851 }
16852 }
16854 /* Substitute template parameters to obtain the specialization. */
16861 {
16864 }
16866 /* The DECL_TI_TEMPLATE should always be the immediate parent
16867 template, not the most general template. */
16871 /* Now we know the specialization, compute access previously
16872 deferred. */
16879 /* If we've just instantiated the main entry point for a function,
16880 instantiate all the alternate entry points as well. We do this
16881 by cloning the instantiation of the main entry point, not by
16882 instantiating the template clones. */
16887 {
16889 {
16890 /* Remember to reinstantiate when we're out of SFINAE so the user
16891 can see the errors. */
16893 }
16895 }
16897 }
16899 /* Wrapper for instantiate_template_1. */
16901 tree
16903 {
16904 tree ret;
16909 }
16911 /* Instantiate the alias template TMPL with ARGS. Also push a template
16912 instantiation level, which instantiate_template doesn't do because
16913 functions and variables have sufficient context established by the
16914 callers. */
16916 static tree
16918 {
16925 {
16928 }
16930 args =
16938 /* We can't free this if a pending_template entry or last_error_tinst_level
16939 is pointing at it. */
16945 }
16947 /* PARM is a template parameter pack for FN. Returns true iff
16948 PARM is used in a deducible way in the argument list of FN. */
16950 static bool
16952 {
16955 {
16957 tree packs;
16963 {
16964 /* The template parameter pack is used in a function parameter
16965 pack. If this is the end of the parameter list, the
16966 template parameter pack is deducible. */
16969 else
16970 /* Otherwise, not. Well, it could be deduced from
16971 a non-pack parameter, but doing so would end up with
16972 a deduction mismatch, so don't bother. */
16974 }
16975 }
16976 /* The template parameter pack isn't used in any function parameter
16977 packs, but it might be used deeper, e.g. tuple<Args...>. */
16979 }
16981 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
16982 NARGS elements of the arguments that are being used when calling
16983 it. TARGS is a vector into which the deduced template arguments
16984 are placed.
16986 Returns either a FUNCTION_DECL for the matching specialization of FN or
16987 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
16988 true, diagnostics will be printed to explain why it failed.
16990 If FN is a conversion operator, or we are trying to produce a specific
16991 specialization, RETURN_TYPE is the return type desired.
16993 The EXPLICIT_TARGS are explicit template arguments provided via a
16994 template-id.
16996 The parameter STRICT is one of:
16998 DEDUCE_CALL:
16999 We are deducing arguments for a function call, as in
17000 [temp.deduct.call].
17002 DEDUCE_CONV:
17003 We are deducing arguments for a conversion function, as in
17004 [temp.deduct.conv].
17006 DEDUCE_EXACT:
17007 We are deducing arguments when doing an explicit instantiation
17008 as in [temp.explicit], when determining an explicit specialization
17009 as in [temp.expl.spec], or when taking the address of a function
17010 template, as in [temp.deduct.funcaddr]. */
17012 tree
17014 tree explicit_targs,
17015 tree targs,
17018 tree return_type,
17019 unification_kind_t strict,
17023 {
17024 tree parms;
17025 tree fntype;
17033 tree tinst;
17039 /* In C++0x, it's possible to have a function template whose type depends
17040 on itself recursively. This is most obvious with decltype, but can also
17041 occur with enumeration scope (c++/48969). So we need to catch infinite
17042 recursion and reject the substitution at deduction time; this function
17043 will return error_mark_node for any repeated substitution.
17045 This also catches excessive recursion such as when f<N> depends on
17046 f<N-1> across all integers, and returns error_mark_node for all the
17047 substitutions back up to the initial one.
17049 This is, of course, not reentrant. */
17059 {
17060 /* [temp.deduct]
17062 The specified template arguments must match the template
17063 parameters in kind (i.e., type, nontype, template), and there
17064 must not be more arguments than there are parameters;
17065 otherwise type deduction fails.
17067 Nontype arguments must match the types of the corresponding
17068 nontype template parameters, or must be convertible to the
17069 types of the corresponding nontype parameters as specified in
17070 _temp.arg.nontype_, otherwise type deduction fails.
17072 All references in the function type of the function template
17073 to the corresponding template parameters are replaced by the
17074 specified template argument values. If a substitution in a
17075 template parameter or in the function type of the function
17076 template results in an invalid type, type deduction fails. */
17081 /* Adjust any explicit template arguments before entering the
17082 substitution context. */
17083 explicit_targs
17085 complain,
17091 /* Substitute the explicit args into the function type. This is
17092 necessary so that, for instance, explicitly declared function
17093 arguments can match null pointed constants. If we were given
17094 an incomplete set of explicit args, we must not do semantic
17095 processing during substitution as we could create partial
17096 instantiations. */
17098 {
17103 /* Dig out the actual parm. */
17106 {
17109 }
17111 {
17114 }
17117 /* No explicit argument for this template parameter. */
17121 {
17122 /* Mark the argument pack as "incomplete". We could
17123 still deduce more arguments during unification.
17124 We remove this mark in type_unification_real. */
17126 {
17130 }
17132 /* We have some incomplete argument packs. */
17134 }
17135 }
17139 {
17142 }
17145 /* Ignore any access checks; we'll see them again in
17146 instantiate_template and they might have the wrong
17147 access path at this point. */
17159 /* Place the explicitly specified arguments in TARGS. */
17162 }
17164 /* Never do unification on the 'this' parameter. */
17168 {
17177 }
17179 /* We allow incomplete unification without an error message here
17180 because the standard doesn't seem to explicitly prohibit it. Our
17181 callers must be ready to deal with unification failures in any
17182 event. */
17185 /* If we aren't explaining yet, push tinst context so we can see where
17186 any errors (e.g. from class instantiations triggered by instantiation
17187 of default template arguments) come from. If we are explaining, this
17188 context is redundant. */
17190 {
17193 }
17195 /* type_unification_real will pass back any access checks from default
17196 template argument substitution. */
17208 /* Now that we have bindings for all of the template arguments,
17209 ensure that the arguments deduced for the template template
17210 parameters have compatible template parameter lists. We cannot
17211 check this property before we have deduced all template
17212 arguments, because the template parameter types of a template
17213 template parameter might depend on prior template parameters
17214 deduced after the template template parameter. The following
17215 ill-formed example illustrates this issue:
17217 template<typename T, template<T> class C> void f(C<5>, T);
17219 template<int N> struct X {};
17221 void g() {
17222 f(X<5>(), 5l); // error: template argument deduction fails
17223 }
17225 The template parameter list of 'C' depends on the template type
17226 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
17227 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
17228 time that we deduce 'C'. */
17231 {
17234 }
17236 /* All is well so far. Now, check:
17238 [temp.deduct]
17240 When all template arguments have been deduced, all uses of
17241 template parameters in nondeduced contexts are replaced with
17242 the corresponding deduced argument values. If the
17243 substitution results in an invalid type, as described above,
17244 type deduction fails. */
17247 {
17250 }
17252 /* Also collect access checks from the instantiation. */
17265 /* Now perform any access checks encountered during substitution. */
17272 /* If we're looking for an exact match, check that what we got
17273 is indeed an exact match. It might not be if some template
17274 parameters are used in non-deduced contexts. But don't check
17275 for an exact match if we have dependent template arguments;
17276 in that case we're doing partial ordering, and we already know
17277 that we have two candidates that will provide the actual type. */
17279 {
17283 tree sarg
17289 {
17293 }
17294 }
17298 fail:
17301 {
17303 /* Reset once we're all the way out. */
17305 }
17307 /* We can't free this if a pending_template entry or last_error_tinst_level
17308 is pointing at it. */
17314 }
17316 /* Adjust types before performing type deduction, as described in
17317 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
17318 sections are symmetric. PARM is the type of a function parameter
17319 or the return type of the conversion function. ARG is the type of
17320 the argument passed to the call, or the type of the value
17321 initialized with the result of the conversion function.
17322 ARG_EXPR is the original argument expression, which may be null. */
17324 static int
17328 tree arg_expr)
17329 {
17333 {
17338 /* Swap PARM and ARG throughout the remainder of this
17339 function; the handling is precisely symmetric since PARM
17340 will initialize ARG rather than vice versa. */
17345 /* Core issue #873: Do the DR606 thing (see below) for these cases,
17346 too, but here handle it by stripping the reference from PARM
17347 rather than by adding it to ARG. */
17355 /* Nothing else to do in this case. */
17360 }
17363 {
17364 /* [temp.deduct.call]
17366 If P is not a reference type:
17368 --If A is an array type, the pointer type produced by the
17369 array-to-pointer standard conversion (_conv.array_) is
17370 used in place of A for type deduction; otherwise,
17372 --If A is a function type, the pointer type produced by
17373 the function-to-pointer standard conversion
17374 (_conv.func_) is used in place of A for type deduction;
17375 otherwise,
17377 --If A is a cv-qualified type, the top level
17378 cv-qualifiers of A's type are ignored for type
17379 deduction. */
17384 else
17386 }
17388 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
17389 of the form T&&, where T is a template parameter, and the argument
17390 is an lvalue, T is deduced as A& */
17396 /* try_one_overload doesn't provide an arg_expr, but
17397 functions are always lvalues. */
17401 /* [temp.deduct.call]
17403 If P is a cv-qualified type, the top level cv-qualifiers
17404 of P's type are ignored for type deduction. If P is a
17405 reference type, the type referred to by P is used for
17406 type deduction. */
17409 {
17412 }
17414 /* DR 322. For conversion deduction, remove a reference type on parm
17415 too (which has been swapped into ARG). */
17420 }
17422 /* Subroutine of unify_one_argument. PARM is a function parameter of a
17423 template which does contain any deducible template parameters; check if
17424 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
17425 unify_one_argument. */
17427 static int
17430 {
17431 tree type;
17435 else
17442 {
17446 }
17448 {
17453 }
17457 else
17459 }
17463 /* Returns true iff the expression EXPR is one from which a template
17464 argument can be deduced. In other words, if it's an undecorated
17465 use of a template non-type parameter. */
17467 static bool
17469 {
17471 }
17473 /* Returns true iff the array domain DOMAIN uses a template parameter in a
17474 deducible way; that is, if it has a max value of <PARM> - 1. */
17476 static bool
17478 {
17487 }
17489 /* Returns true iff the template arguments ARGS use a template parameter
17490 in a deducible way. */
17492 static bool
17494 {
17496 {
17501 else
17502 {
17509 else
17511 }
17514 }
17516 }
17518 /* Returns true iff TYPE contains any deducible references to template
17519 parameters, as per 14.8.2.5. */
17521 static bool
17523 {
17527 /* T
17528 cv-list T
17529 TT<T>
17530 TT<i>
17531 TT<> */
17536 /* T*
17537 T&
17538 T&& */
17542 /* T[integer-constant ]
17543 type [i] */
17548 /* T type ::*
17549 type T::*
17550 T T::*
17551 T (type ::*)()
17552 type (T::*)()
17553 type (type ::*)(T)
17554 type (T::*)(T)
17555 T (type ::*)(T)
17556 T (T::*)()
17557 T (T::*)(T) */
17560 || (uses_deducible_template_parms
17563 /* template-name <T> (where template-name refers to a class template)
17564 template-name <i> (where template-name refers to a class template) */
17571 /* type (T)
17572 T()
17573 T(T) */
17576 {
17585 }
17588 }
17590 /* Subroutine of type_unification_real and unify_pack_expansion to
17591 handle unification of a single P/A pair. Parameters are as
17592 for those functions. */
17594 static int
17598 {
17605 /* We can't deduce anything from this, but we might get all the
17606 template args from other function args. */
17609 /* Implicit conversions (Clause 4) will be performed on a function
17610 argument to convert it to the type of the corresponding function
17611 parameter if the parameter type contains no template-parameters that
17612 participate in template argument deduction. */
17615 /* For function parameters with no deducible template parameters,
17616 just return. We'll check non-dependent conversions later. */
17620 {
17622 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
17623 | UNIFY_ALLOW_MORE_CV_QUAL
17637 }
17639 /* We only do these transformations if this is the top-level
17640 parameter_type_list in a call or declaration matching; in other
17641 situations (nested function declarators, template argument lists) we
17642 won't be comparing a type to an expression, and we don't do any type
17643 adjustments. */
17645 {
17647 {
17650 {
17651 /* [temp.deduct.type] A template-argument can be
17652 deduced from a pointer to function or pointer
17653 to member function argument if the set of
17654 overloaded functions does not contain function
17655 templates and at most one of a set of
17656 overloaded functions provides a unique
17657 match. */
17664 }
17670 }
17672 arg_strict |=
17674 }
17675 else
17680 /* For deduction from an init-list we need the actual list. */
17684 }
17686 /* Most parms like fn_type_unification.
17688 If SUBR is 1, we're being called recursively (to unify the
17689 arguments of a function or method parameter of a function
17690 template).
17692 CHECKS is a pointer to a vector of access checks encountered while
17693 substituting default template arguments. */
17695 static int
17697 tree targs,
17698 tree xparms,
17702 unification_kind_t strict,
17706 {
17711 tree parms;
17720 /* Reset the number of non-defaulted template arguments contained
17721 in TARGS. */
17724 again:
17732 {
17737 /* For a function parameter pack that occurs at the end of the
17738 parameter-declaration-list, the type A of each remaining
17739 argument of the call is compared with the type P of the
17740 declarator-id of the function parameter pack. */
17746 /* For a function parameter pack that does not occur at the
17747 end of the parameter-declaration-list, the type of the
17748 parameter pack is a non-deduced context. */
17755 explain_p))
17757 }
17762 {
17763 /* Unify the remaining arguments with the pack expansion type. */
17764 tree argvec;
17767 /* Allocate a TREE_VEC and copy in all of the arguments */
17772 /* Copy the parameter into parmvec. */
17778 /* Advance to the end of the list of parameters. */
17780 }
17782 /* Fail if we've reached the end of the parm list, and more args
17783 are present, and the parm list isn't variadic. */
17786 /* Fail if parms are left and they don't have default values and
17787 they aren't all deduced as empty packs (c++/57397). This is
17788 consistent with sufficient_parms_p. */
17791 {
17795 do
17796 {
17799 count++;
17801 }
17805 type_pack_p);
17806 }
17809 {
17810 tsubst_flags_t complain = (explain_p
17811 ? tf_warning_or_error
17815 {
17819 /* Clear the "incomplete" flags on all argument packs now so that
17820 substituting them into later default arguments works. */
17822 {
17825 }
17831 /* If this is an undeduced nontype parameter that depends on
17832 a type parameter, try another pass; its type may have been
17833 deduced from a later argument than the one from which
17834 this parameter can be deduced. */
17838 {
17841 }
17843 /* Core issue #226 (C++0x) [temp.deduct]:
17845 If a template argument has not been deduced, its
17846 default template argument, if any, is used.
17848 When we are in C++98 mode, TREE_PURPOSE will either
17849 be NULL_TREE or ERROR_MARK_NODE, so we do not need
17850 to explicitly check cxx_dialect here. */
17852 /* OK, there is a default argument. Wait until after the
17853 conversion check to do substitution. */
17856 /* If the type parameter is a parameter pack, then it will
17857 be deduced to an empty parameter pack. */
17859 {
17860 tree arg;
17863 {
17867 }
17868 else
17875 }
17878 }
17880 /* DR 1391: All parameters have args, now check non-dependent parms for
17881 convertibility. */
17885 {
17891 /* For a function parameter pack that occurs at the end of the
17892 parameter-declaration-list, the type A of each remaining
17893 argument of the call is compared with the type P of the
17894 declarator-id of the function parameter pack. */
17900 /* For a function parameter pack that does not occur at the
17901 end of the parameter-declaration-list, the type of the
17902 parameter pack is a non-deduced context. */
17911 explain_p))
17913 }
17915 /* Now substitute into the default template arguments. */
17917 {
17943 else
17944 {
17946 /* The position of the first default template argument,
17947 is also the number of non-defaulted arguments in TARGS.
17948 Record that. */
17952 }
17953 }
17957 }
17958 #ifdef ENABLE_CHECKING
17961 #endif
17964 }
17966 /* Subroutine of type_unification_real. Args are like the variables
17967 at the call site. ARG is an overloaded function (or template-id);
17968 we try deducing template args from each of the overloads, and if
17969 only one succeeds, we go with that. Modifies TARGS and returns
17970 true on success. */
17972 static bool
17974 tree targs,
17975 tree parm,
17976 tree arg,
17977 unification_kind_t strict,
17980 {
17987 {
17990 }
17991 else
17995 /* Handle `&x' where `x' is some static or non-static member
17996 function name. */
18002 /* Strip baselink information. */
18007 {
18008 /* If we got some explicit template args, we need to plug them into
18009 the affected templates before we try to unify, in case the
18010 explicit args will completely resolve the templates in question. */
18017 {
18030 {
18035 {
18038 }
18039 }
18042 }
18043 /* If no templates (or more than one) are fully resolved by the
18044 explicit arguments, this template-id is a non-deduced context; it
18045 could still be OK if we deduce all template arguments for the
18046 enclosing call through other arguments. */
18049 }
18052 /* If ARG is, for example, "(0, &f)" then its type will be unknown
18053 -- but the deduction does not succeed because the expression is
18054 not just the function on its own. */
18056 else
18062 {
18065 }
18067 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18068 to function or pointer to member function argument if the set of
18069 overloaded functions does not contain function templates and at most
18070 one of a set of overloaded functions provides a unique match.
18072 So if we found multiple possibilities, we return success but don't
18073 deduce anything. */
18076 {
18080 {
18085 /* Don't forget explicit template arguments in a pack. */
18089 }
18090 }
18095 }
18097 /* Core DR 115: In contexts where deduction is done and fails, or in
18098 contexts where deduction is not done, if a template argument list is
18099 specified and it, along with any default template arguments, identifies
18100 a single function template specialization, then the template-id is an
18101 lvalue for the function template specialization. */
18103 tree
18105 {
18118 {
18121 }
18123 {
18126 }
18128 {
18131 }
18134 {
18138 /* If we got some explicit template args, we need to plug them into
18139 the affected templates before we try to unify, in case the
18140 explicit args will completely resolve the templates in question. */
18148 {
18161 {
18164 {
18167 }
18169 {
18172 }
18173 }
18174 }
18176 {
18184 {
18185 tree base
18188 }
18192 }
18194 /* There were no good options and at least one bad one, so let the
18195 user know what the problem is. */
18197 }
18199 }
18201 /* Subroutine of resolve_overloaded_unification; does deduction for a single
18202 overload. Fills TARGS with any deduced arguments, or error_mark_node if
18203 different overloads deduce different arguments for a given parm.
18204 ADDR_P is true if the expression for which deduction is being
18205 performed was of the form "& fn" rather than simply "fn".
18207 Returns 1 on success. */
18209 static int
18211 tree orig_targs,
18212 tree targs,
18213 tree parm,
18214 tree arg,
18215 unification_kind_t strict,
18219 {
18221 tree tempargs;
18227 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18228 to function or pointer to member function argument if the set of
18229 overloaded functions does not contain function templates and at most
18230 one of a set of overloaded functions provides a unique match.
18232 So if this is a template, just return success. */
18244 /* We don't copy orig_targs for this because if we have already deduced
18245 some template args from previous args, unify would complain when we
18246 try to deduce a template parameter for the same argument, even though
18247 there isn't really a conflict. */
18254 /* First make sure we didn't deduce anything that conflicts with
18255 explicitly specified args. */
18257 {
18264 /* Since we're unifying against ourselves, we will fill in
18265 template args used in the function parm list with our own
18266 template parms. Discard them. */
18270 }
18273 {
18278 }
18281 }
18283 /* PARM is a template class (perhaps with unbound template
18284 parameters). ARG is a fully instantiated type. If ARG can be
18285 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
18286 TARGS are as for unify. */
18288 static tree
18291 {
18292 tree copy_of_targs;
18299 /* We need to make a new template argument vector for the call to
18300 unify. If we used TARGS, we'd clutter it up with the result of
18301 the attempted unification, even if this class didn't work out.
18302 We also don't want to commit ourselves to all the unifications
18303 we've already done, since unification is supposed to be done on
18304 an argument-by-argument basis. In other words, consider the
18305 following pathological case:
18307 template <int I, int J, int K>
18308 struct S {};
18310 template <int I, int J>
18311 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
18313 template <int I, int J, int K>
18314 void f(S<I, J, K>, S<I, I, I>);
18316 void g() {
18317 S<0, 0, 0> s0;
18318 S<0, 1, 2> s2;
18320 f(s0, s2);
18321 }
18323 Now, by the time we consider the unification involving `s2', we
18324 already know that we must have `f<0, 0, 0>'. But, even though
18325 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
18326 because there are two ways to unify base classes of S<0, 1, 2>
18327 with S<I, I, I>. If we kept the already deduced knowledge, we
18328 would reject the possibility I=1. */
18331 /* If unification failed, we're done. */
18337 }
18339 /* Given a template type PARM and a class type ARG, find the unique
18340 base type in ARG that is an instance of PARM. We do not examine
18341 ARG itself; only its base-classes. If there is not exactly one
18342 appropriate base class, return NULL_TREE. PARM may be the type of
18343 a partial specialization, as well as a plain template type. Used
18344 by unify. */
18346 static enum template_base_result
18349 {
18351 tree binfo;
18357 {
18358 /* The type could not be completed. */
18361 }
18363 /* Walk in inheritance graph order. The search order is not
18364 important, and this avoids multiple walks of virtual bases. */
18366 {
18371 {
18372 /* If there is more than one satisfactory baseclass, then:
18374 [temp.deduct.call]
18376 If they yield more than one possible deduced A, the type
18377 deduction fails.
18379 applies. */
18381 {
18384 }
18387 }
18388 }
18392 }
18394 /* Returns the level of DECL, which declares a template parameter. */
18396 static int
18398 {
18400 {
18410 }
18412 }
18414 /* Decide whether ARG can be unified with PARM, considering only the
18415 cv-qualifiers of each type, given STRICT as documented for unify.
18416 Returns nonzero iff the unification is OK on that basis. */
18418 static int
18420 {
18426 {
18427 /* Although a CVR qualifier is ignored when being applied to a
18428 substituted template parameter ([8.3.2]/1 for example), that
18429 does not allow us to unify "const T" with "int&" because both
18430 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
18431 It is ok when we're allowing additional CV qualifiers
18432 at the outer level [14.8.2.1]/3,1st bullet. */
18442 }
18453 }
18455 /* Determines the LEVEL and INDEX for the template parameter PARM. */
18456 void
18458 {
18462 {
18465 }
18466 else
18467 {
18470 }
18471 }
18473 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
18474 do { \
18475 if (unify (TP, TA, P, A, S, EP)) \
18476 return 1; \
18477 } while (0);
18479 /* Unifies the remaining arguments in PACKED_ARGS with the pack
18480 expansion at the end of PACKED_PARMS. Returns 0 if the type
18481 deduction succeeds, 1 otherwise. STRICT is the same as in
18482 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
18483 call argument list. We'll need to adjust the arguments to make them
18484 types. SUBR tells us if this is from a recursive call to
18485 type_unification_real, or for comparing two template argument
18486 lists. */
18488 static int
18492 {
18493 tree parm
18503 /* Determine the parameter packs we will be deducing from the
18504 pattern, and record their current deductions. */
18507 {
18511 /* Determine the index and level of this parameter pack. */
18514 /* Keep track of the parameter packs and their corresponding
18515 argument packs. */
18518 }
18520 /* Loop through all of the arguments that have not yet been
18521 unified and unify each with the pattern. */
18523 {
18524 tree parm;
18528 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
18529 or the element of its argument pack at the current index if
18530 this argument was explicitly specified. */
18532 {
18541 {
18544 }
18546 }
18548 /* If we had explicit template arguments, substitute them into the
18549 pattern before deduction. */
18551 {
18552 /* Some arguments might still be unspecified or dependent. */
18560 NULL_TREE);
18565 }
18566 else
18569 /* Unify the pattern with the current argument. */
18571 explain_p))
18574 /* For each parameter pack, collect the deduced value. */
18576 {
18582 }
18583 }
18585 /* Verify that the results of unification with the parameter packs
18586 produce results consistent with what we've seen before, and make
18587 the deduced argument packs available. */
18589 {
18596 /* By default keep the original deduced argument pack.
18597 If necessary, more specific code is going to update the
18598 resulting deduced argument later down in this function. */
18602 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
18603 actually deduce anything. */
18611 {
18612 /* If we had fewer function args than explicit template args,
18613 just use the explicits. */
18618 }
18621 {
18622 tree result;
18623 /* Build the deduced *_ARGUMENT_PACK. */
18625 {
18630 }
18631 else
18636 /* Note the deduced argument packs for this parameter
18637 pack. */
18639 }
18643 {
18644 /* We only had the explicitly-provided arguments before, but
18645 now we have a complete set of arguments. */
18651 }
18652 else
18653 {
18659 /* Inconsistent unification of this parameter pack. */
18661 bad_old_arg,
18662 bad_new_arg);
18663 }
18664 }
18667 }
18669 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
18670 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
18671 parameters and return value are as for unify. */
18673 static int
18677 {
18678 tree parm_max;
18679 tree arg_max;
18683 /* Our representation of array types uses "N - 1" as the
18684 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
18685 not an integer constant. We cannot unify arbitrarily
18686 complex expressions, so we eliminate the MINUS_EXPRs
18687 here. */
18691 {
18694 }
18698 {
18699 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
18700 trying to unify the type of a variable with the type
18701 of a template parameter. For example:
18703 template <unsigned int N>
18704 void f (char (&) [N]);
18705 int g();
18706 void h(int i) {
18707 char a[g(i)];
18708 f(a);
18709 }
18711 Here, the type of the ARG will be "int [g(i)]", and
18712 may be a SAVE_EXPR, etc. */
18716 }
18718 /* If only one of the bounds used a MINUS_EXPR, compensate
18719 by adding one to the other bound. */
18722 integer_type_node,
18723 parm_max,
18724 integer_one_node);
18727 integer_type_node,
18728 arg_max,
18729 integer_one_node);
18733 }
18735 /* Deduce the value of template parameters. TPARMS is the (innermost)
18736 set of template parameters to a template. TARGS is the bindings
18737 for those template parameters, as determined thus far; TARGS may
18738 include template arguments for outer levels of template parameters
18739 as well. PARM is a parameter to a template function, or a
18740 subcomponent of that parameter; ARG is the corresponding argument.
18741 This function attempts to match PARM with ARG in a manner
18742 consistent with the existing assignments in TARGS. If more values
18743 are deduced, then TARGS is updated.
18745 Returns 0 if the type deduction succeeds, 1 otherwise. The
18746 parameter STRICT is a bitwise or of the following flags:
18748 UNIFY_ALLOW_NONE:
18749 Require an exact match between PARM and ARG.
18750 UNIFY_ALLOW_MORE_CV_QUAL:
18751 Allow the deduced ARG to be more cv-qualified (by qualification
18752 conversion) than ARG.
18753 UNIFY_ALLOW_LESS_CV_QUAL:
18754 Allow the deduced ARG to be less cv-qualified than ARG.
18755 UNIFY_ALLOW_DERIVED:
18756 Allow the deduced ARG to be a template base class of ARG,
18757 or a pointer to a template base class of the type pointed to by
18758 ARG.
18759 UNIFY_ALLOW_INTEGER:
18760 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
18761 case for more information.
18762 UNIFY_ALLOW_OUTER_LEVEL:
18763 This is the outermost level of a deduction. Used to determine validity
18764 of qualification conversions. A valid qualification conversion must
18765 have const qualified pointers leading up to the inner type which
18766 requires additional CV quals, except at the outer level, where const
18767 is not required [conv.qual]. It would be normal to set this flag in
18768 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
18769 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
18770 This is the outermost level of a deduction, and PARM can be more CV
18771 qualified at this point.
18772 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
18773 This is the outermost level of a deduction, and PARM can be less CV
18774 qualified at this point. */
18776 static int
18779 {
18781 tree targ;
18782 tree tparm;
18785 /* I don't think this will do the right thing with respect to types.
18786 But the only case I've seen it in so far has been array bounds, where
18787 signedness is the only information lost, and I think that will be
18788 okay. */
18796 /* We can't deduce anything from this, but we might get all the
18797 template args from other function args. */
18800 /* If PARM uses template parameters, then we can't bail out here,
18801 even if ARG == PARM, since we won't record unifications for the
18802 template parameters. We might need them if we're trying to
18803 figure out which of two things is more specialized. */
18807 /* Handle init lists early, so the rest of the function can assume
18808 we're dealing with a type. */
18810 {
18815 /* Replace T with std::initializer_list<T> for deduction. */
18822 /* We can only deduce from an initializer list argument if the
18823 parameter is std::initializer_list or an array; otherwise this
18824 is a non-deduced context. */
18829 else
18830 {
18832 /* Deduction is defined in terms of a single type, so just punt
18833 on the (bizarre) std::initializer_list<T...>. */
18836 }
18839 {
18846 {
18850 /* It should only be possible to get here for a call. */
18852 elt_strict |= maybe_adjust_types_for_deduction
18855 }
18858 explain_p);
18859 }
18863 {
18864 /* Also deduce from the length of the initializer list. */
18871 }
18873 /* If the std::initializer_list<T> deduction worked, replace the
18874 deduced A with std::initializer_list<A>. */
18876 {
18881 }
18883 }
18885 /* Immediately reject some pairs that won't unify because of
18886 cv-qualification mismatches. */
18889 /* It is the elements of the array which hold the cv quals of an array
18890 type, and the elements might be template type parms. We'll check
18891 when we recurse. */
18893 /* We check the cv-qualifiers when unifying with template type
18894 parameters below. We want to allow ARG `const T' to unify with
18895 PARM `T' for example, when computing which of two templates
18896 is more specialized, for example. */
18910 {
18914 /* In a type which contains a nested-name-specifier, template
18915 argument values cannot be deduced for template parameters used
18916 within the nested-name-specifier. */
18928 /* The PARM is not one we're trying to unify. Just check
18929 to see if it matches ARG. */
18930 {
18935 else
18937 }
18944 /* Check for mixed types and values. */
18952 {
18953 /* ARG must be constructed from a template class or a template
18954 template parameter. */
18958 {
18960 /* An alias template name is never deduced. */
18965 tree parm_parms
18966 = DECL_INNERMOST_TEMPLATE_PARMS
18971 /* The resolution to DR150 makes clear that default
18972 arguments for an N-argument may not be used to bind T
18973 to a template template parameter with fewer than N
18974 parameters. It is not safe to permit the binding of
18975 default arguments as an extension, as that may change
18976 the meaning of a conforming program. Consider:
18978 struct Dense { static const unsigned int dim = 1; };
18980 template <template <typename> class View,
18981 typename Block>
18982 void operator+(float, View<Block> const&);
18984 template <typename Block,
18985 unsigned int Dim = Block::dim>
18986 struct Lvalue_proxy { operator float() const; };
18988 void
18989 test_1d (void) {
18990 Lvalue_proxy<Dense> p;
18991 float b;
18992 b + p;
18993 }
18995 Here, if Lvalue_proxy is permitted to bind to View, then
18996 the global operator+ will be used; if they are not, the
18997 Lvalue_proxy will be converted to float. */
18999 full_argvec,
19001 (explain_p
19002 ? tf_warning_or_error
19009 /* Deduce arguments T, i from TT<T> or TT<i>.
19010 We check each element of PARMVEC and ARGVEC individually
19011 rather than the whole TREE_VEC since they can have
19012 different number of elements. */
19019 /* Check if the parameters end in a pack, making them
19020 variadic. */
19026 /* If the template argument list of P contains a pack
19027 expansion that is not the last template argument, the
19028 entire template argument list is a non-deduced
19029 context. */
19038 {
19043 }
19048 DEDUCE_EXACT,
19051 }
19054 /* Fall through to deduce template name. */
19055 }
19059 {
19060 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
19062 /* Simple cases: Value already set, does match or doesn't. */
19067 }
19068 else
19069 {
19070 /* If PARM is `const T' and ARG is only `int', we don't have
19071 a match unless we are allowing additional qualification.
19072 If ARG is `const int' and PARM is just `T' that's OK;
19073 that binds `const int' to `T'. */
19078 /* Consider the case where ARG is `const volatile int' and
19079 PARM is `const T'. Then, T should be `volatile int'. */
19080 arg = cp_build_qualified_type_real
19085 /* Simple cases: Value already set, does match or doesn't. */
19091 /* Make sure that ARG is not a variable-sized array. (Note
19092 that were talking about variable-sized arrays (like
19093 `int[n]'), rather than arrays of unknown size (like
19094 `int[]').) We'll get very confused by such a type since
19095 the bound of the array is not constant, and therefore
19096 not mangleable. Besides, such types are not allowed in
19097 ISO C++, so we can do as we please here. We do allow
19098 them for 'auto' deduction, since that isn't ABI-exposed. */
19102 /* Strip typedefs as in convert_template_argument. */
19104 }
19106 /* If ARG is a parameter pack or an expansion, we cannot unify
19107 against it unless PARM is also a parameter pack. */
19112 /* If the argument deduction results is a METHOD_TYPE,
19113 then there is a problem.
19114 METHOD_TYPE doesn't map to any real C++ type the result of
19115 the deduction can not be of that type. */
19129 {
19130 /* The PARM is not one we're trying to unify. Just check
19131 to see if it matches ARG. */
19137 }
19143 {
19148 }
19150 /* [temp.deduct.type] If, in the declaration of a function template
19151 with a non-type template-parameter, the non-type
19152 template-parameter is used in an expression in the function
19153 parameter-list and, if the corresponding template-argument is
19154 deduced, the template-argument type shall match the type of the
19155 template-parameter exactly, except that a template-argument
19156 deduced from an array bound may be of any integral type.
19157 The non-type parameter might use already deduced type parameters. */
19160 /* Template-parameter dependent expression. Just accept it for now.
19161 It will later be processed in convert_template_argument. */
19162 ;
19167 /* Convert the ARG to the type of PARM; the deduced non-type
19168 template argument must exactly match the types of the
19169 corresponding parameter. */
19172 /* We haven't deduced the type of this parameter yet. Try again
19173 later. */
19175 else
19178 /* If ARG is a parameter pack or an expansion, we cannot unify
19179 against it unless PARM is also a parameter pack. */
19184 {
19187 }
19192 {
19193 /* A pointer-to-member constant can be unified only with
19194 another constant. */
19198 /* Just unify the class member. It would be useless (and possibly
19199 wrong, depending on the strict flags) to unify also
19200 PTRMEM_CST_CLASS, because we want to be sure that both parm and
19201 arg refer to the same variable, even if through different
19202 classes. For instance:
19204 struct A { int x; };
19205 struct B : A { };
19207 Unification of &A::x and &B::x must succeed. */
19210 }
19213 {
19217 /* [temp.deduct.call]
19219 A can be another pointer or pointer to member type that can
19220 be converted to the deduced A via a qualification
19221 conversion (_conv.qual_).
19223 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
19224 This will allow for additional cv-qualification of the
19225 pointed-to types if appropriate. */
19228 /* The derived-to-base conversion only persists through one
19229 level of pointers. */
19234 }
19266 /* We have already checked cv-qualification at the top of the
19267 function. */
19271 /* As far as unification is concerned, this wins. Later checks
19272 will invalidate it if necessary. */
19275 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
19276 /* Type INTEGER_CST can come from ordinary constant template args. */
19288 {
19298 /* Check for pack expansions in the parameters. */
19300 {
19302 {
19304 /* We can unify against something with a trailing
19305 parameter pack. */
19307 else
19308 /* [temp.deduct.type]/9: If the template argument list of
19309 P contains a pack expansion that is not the last
19310 template argument, the entire template argument list
19311 is a non-deduced context. */
19313 }
19314 }
19316 /* If we don't have enough arguments to satisfy the parameters
19317 (not counting the pack expression at the end), or we have
19318 too many arguments for a parameter list that doesn't end in
19319 a pack expression, we can't unify. */
19325 /* Unify all of the parameters that precede the (optional)
19326 pack expression. */
19328 {
19333 }
19336 DEDUCE_EXACT,
19339 }
19347 {
19355 }
19360 {
19364 {
19365 /* First, we try to unify the PARM and ARG directly. */
19370 {
19371 /* Fallback to the special case allowed in
19372 [temp.deduct.call]:
19374 If P is a class, and P has the form
19375 template-id, then A can be a derived class of
19376 the deduced A. Likewise, if P is a pointer to
19377 a class of the form template-id, A can be a
19378 pointer to a derived class pointed to by the
19379 deduced A. */
19386 }
19387 }
19391 /* Perhaps PARM is something like S<U> and ARG is S<int>.
19392 Then, we should unify `int' and `U'. */
19394 else
19395 /* There's no chance of unification succeeding. */
19400 }
19407 {
19410 tree a;
19416 /* CV qualifications for methods can never be deduced, they must
19417 match exactly. We need to check them explicitly here,
19418 because type_unification_real treats them as any other
19419 cv-qualified parameter. */
19421 && (!check_cv_quals_for_unify
19441 }
19444 /* Unify a pointer to member with a pointer to member function, which
19445 deduces the type of the member as a function type. */
19447 {
19448 /* Check top-level cv qualifiers */
19456 /* Determine the type of the function we are unifying against. */
19460 }
19479 /* Matched cases are handled by the ARG == PARM test above. */
19483 /* A non-type template parameter that is a variable should be a
19484 an integral constant, in which case, it whould have been
19485 folded into its (constant) value. So we should not be getting
19486 a variable here. */
19497 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
19498 or UNDERLYING_TYPE nodes. */
19502 /* Unification fails if we hit an error node. */
19507 {
19512 }
19513 /* FALLTHRU */
19516 /* An unresolved overload is a nondeduced context. */
19521 /* We must be looking at an expression. This can happen with
19522 something like:
19524 template <int I>
19525 void foo(S<I>, S<I + 2>);
19527 This is a "nondeduced context":
19529 [deduct.type]
19531 The nondeduced contexts are:
19533 --A type that is a template-id in which one or more of
19534 the template-arguments is an expression that references
19535 a template-parameter.
19537 In these cases, we assume deduction succeeded, but don't
19538 actually infer any unifications. */
19543 else
19545 }
19546 }
19547 #undef RECUR_AND_CHECK_FAILURE
19548 \f
19549 /* Note that DECL can be defined in this translation unit, if
19550 required. */
19552 static void
19554 {
19555 tree clone;
19559 }
19561 /* Called if RESULT is explicitly instantiated, or is a member of an
19562 explicitly instantiated class. */
19564 void
19566 {
19569 /* If this entity has already been written out, it's too late to
19570 make any modifications. */
19574 /* For anonymous namespace we don't need to do anything. */
19576 {
19579 }
19582 /* The TREE_PUBLIC flag for function declarations will have been
19583 set correctly by tsubst. */
19586 /* This might have been set by an earlier implicit instantiation. */
19591 else
19592 {
19595 /* Always make artificials weak. */
19598 /* For WIN32 we also want to put explicit instantiations in
19599 linkonce sections. */
19602 }
19604 /* If EXTERN_P, then this function will not be emitted -- unless
19605 followed by an explicit instantiation, at which point its linkage
19606 will be adjusted. If !EXTERN_P, then this function will be
19607 emitted here. In neither circumstance do we want
19608 import_export_decl to adjust the linkage. */
19610 }
19612 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
19613 important template arguments. If any are missing, we check whether
19614 they're important by using error_mark_node for substituting into any
19615 args that were used for partial ordering (the ones between ARGS and END)
19616 and seeing if it bubbles up. */
19618 static bool
19620 {
19625 {
19628 }
19630 {
19634 }
19636 }
19638 /* Given two function templates PAT1 and PAT2, return:
19640 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
19641 -1 if PAT2 is more specialized than PAT1.
19642 0 if neither is more specialized.
19644 LEN indicates the number of parameters we should consider
19645 (defaulted parameters should not be considered).
19647 The 1998 std underspecified function template partial ordering, and
19648 DR214 addresses the issue. We take pairs of arguments, one from
19649 each of the templates, and deduce them against each other. One of
19650 the templates will be more specialized if all the *other*
19651 template's arguments deduce against its arguments and at least one
19652 of its arguments *does* *not* deduce against the other template's
19653 corresponding argument. Deduction is done as for class templates.
19654 The arguments used in deduction have reference and top level cv
19655 qualifiers removed. Iff both arguments were originally reference
19656 types *and* deduction succeeds in both directions, an lvalue reference
19657 wins against an rvalue reference and otherwise the template
19658 with the more cv-qualified argument wins for that pairing (if
19659 neither is more cv-qualified, they both are equal). Unlike regular
19660 deduction, after all the arguments have been deduced in this way,
19661 we do *not* verify the deduced template argument values can be
19662 substituted into non-deduced contexts.
19664 The logic can be a bit confusing here, because we look at deduce1 and
19665 targs1 to see if pat2 is at least as specialized, and vice versa; if we
19666 can find template arguments for pat1 to make arg1 look like arg2, that
19667 means that arg2 is at least as specialized as arg1. */
19669 int
19671 {
19684 /* Remove the this parameter from non-static member functions. If
19685 one is a non-static member function and the other is not a static
19686 member function, remove the first parameter from that function
19687 also. This situation occurs for operator functions where we
19688 locate both a member function (with this pointer) and non-member
19689 operator (with explicit first operand). */
19691 {
19696 }
19698 {
19701 {
19702 len--;
19704 }
19705 }
19707 /* If only one is a conversion operator, they are unordered. */
19711 /* Consider the return type for a conversion function */
19713 {
19716 len++;
19717 }
19719 processing_template_decl++;
19725 /* Stop when an ellipsis is seen. */
19727 {
19738 {
19739 /* When both arguments are pack expansions, we need only
19740 unify the patterns themselves. */
19744 /* This is the last comparison we need to do. */
19746 }
19749 {
19753 }
19756 {
19760 }
19766 {
19772 /* Setup the parameter vector, which contains only ARG1. */
19775 /* Setup the argument vector, which contains the remaining
19776 arguments. */
19785 /* We cannot deduce in the other direction, because ARG1 is
19786 a pack expansion but ARG2 is not. */
19788 }
19790 {
19796 /* Setup the parameter vector, which contains only ARG1. */
19799 /* Setup the argument vector, which contains the remaining
19800 arguments. */
19809 /* We cannot deduce in the other direction, because ARG2 is
19810 a pack expansion but ARG1 is not.*/
19812 }
19814 else
19815 {
19816 /* The normal case, where neither argument is a pack
19817 expansion. */
19824 }
19826 /* If we couldn't deduce arguments for tparms1 to make arg1 match
19827 arg2, then arg2 is not as specialized as arg1. */
19833 /* "If, for a given type, deduction succeeds in both directions
19834 (i.e., the types are identical after the transformations above)
19835 and both P and A were reference types (before being replaced with
19836 the type referred to above):
19837 - if the type from the argument template was an lvalue reference and
19838 the type from the parameter template was not, the argument type is
19839 considered to be more specialized than the other; otherwise,
19840 - if the type from the argument template is more cv-qualified
19841 than the type from the parameter template (as described above),
19842 the argument type is considered to be more specialized than the other;
19843 otherwise,
19844 - neither type is more specialized than the other." */
19847 {
19849 {
19852 else
19854 }
19856 {
19861 }
19862 }
19865 /* We've failed to deduce something in either direction.
19866 These must be unordered. */
19871 /* We have already processed all of the arguments in our
19872 handing of the pack expansion type. */
19877 }
19879 /* "In most cases, all template parameters must have values in order for
19880 deduction to succeed, but for partial ordering purposes a template
19881 parameter may remain without a value provided it is not used in the
19882 types being used for partial ordering."
19884 Thus, if we are missing any of the targs1 we need to substitute into
19885 origs1, then pat2 is not as specialized as pat1. This can happen when
19886 there is a nondeduced context. */
19892 processing_template_decl--;
19894 /* If both deductions succeed, the partial ordering selects the more
19895 constrained template. */
19897 {
19902 }
19904 /* All things being equal, if the next argument is a pack expansion
19905 for one function but not for the other, prefer the
19906 non-variadic function. FIXME this is bogus; see c++/41958. */
19910 {
19913 }
19919 else
19921 }
19923 /* Determine which of two partial specializations of TMPL is more
19924 specialized.
19926 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
19927 to the first partial specialization. The TREE_PURPOSE is the
19928 innermost set of template parameters for the partial
19929 specialization. PAT2 is similar, but for the second template.
19931 Return 1 if the first partial specialization is more specialized;
19932 -1 if the second is more specialized; 0 if neither is more
19933 specialized.
19935 See [temp.class.order] for information about determining which of
19936 two templates is more specialized. */
19938 static int
19940 {
19941 tree targs;
19952 /* Just like what happens for functions, if we are ordering between
19953 different template specializations, we may encounter dependent
19954 types in the arguments, and we need our dependency check functions
19955 to behave correctly. */
19959 {
19962 }
19966 {
19969 }
19972 /* If both deductions succeed, the partial ordering selects the more
19973 constrained template. */
19977 /* In the case of a tie where at least one of the templates
19978 has a parameter pack at the end, the template with the most
19979 non-packed parameters wins. */
19981 && any_deductions
19984 {
19990 /* We don't count the pack expansion at the end. */
20000 }
20003 }
20005 /* Return the template arguments that will produce the function signature
20006 DECL from the function template FN, with the explicit template
20007 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
20008 also match. Return NULL_TREE if no satisfactory arguments could be
20009 found. */
20011 static tree
20013 {
20017 tree decl_arg_types;
20020 tree arg;
20024 /* Never do unification on the 'this' parameter. */
20045 }
20047 /* Return the innermost template arguments that, when applied to a partial
20048 specialization of TMPL whose innermost template parameters are
20049 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
20050 ARGS.
20052 For example, suppose we have:
20054 template <class T, class U> struct S {};
20055 template <class T> struct S<T*, int> {};
20057 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
20058 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
20059 int}. The resulting vector will be {double}, indicating that `T'
20060 is bound to `double'. */
20062 static tree
20064 {
20066 tree deduced_args;
20067 tree innermost_deduced_args;
20071 {
20075 innermost_deduced_args);
20076 }
20077 else
20090 /* Verify that nondeduced template arguments agree with the type
20091 obtained from argument deduction.
20093 For example:
20095 struct A { typedef int X; };
20096 template <class T, class U> struct C {};
20097 template <class T> struct C<T, typename T::X> {};
20099 Then with the instantiation `C<A, int>', we can deduce that
20100 `T' is `A' but unify () does not check whether `typename T::X'
20101 is `int'. */
20107 /* We only need to check the innermost arguments; the other
20108 arguments will always agree. */
20113 /* Now that we have bindings for all of the template arguments,
20114 ensure that the arguments deduced for the template template
20115 parameters have compatible template parameter lists. See the use
20116 of template_template_parm_bindings_ok_p in fn_type_unification
20117 for more information. */
20122 }
20124 // Compare two function templates T1 and T2 by deducing bindings
20125 // from one against the other. If both deductions succeed, compare
20126 // constraints to see which is more constrained.
20127 static int
20129 {
20134 {
20137 }
20140 {
20143 }
20145 // If both deductions succeed, then one may be more constrained.
20150 }
20152 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
20153 Return the TREE_LIST node with the most specialized template, if
20154 any. If there is no most specialized template, the error_mark_node
20155 is returned.
20157 Note that this function does not look at, or modify, the
20158 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
20159 returned is one of the elements of INSTANTIATIONS, callers may
20160 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
20161 and retrieve it from the value returned. */
20163 tree
20165 {
20172 {
20177 {
20178 /* Equally specialized, move to next function. If there
20179 is no next function, nothing's most specialized. */
20184 }
20185 }
20188 /* Now verify that champ is better than everything earlier in the
20189 instantiation list. */
20192 {
20195 }
20196 }
20198 processing_template_decl--;
20204 }
20206 /* If DECL is a specialization of some template, return the most
20207 general such template. Otherwise, returns NULL_TREE.
20209 For example, given:
20211 template <class T> struct S { template <class U> void f(U); };
20213 if TMPL is `template <class U> void S<int>::f(U)' this will return
20214 the full template. This function will not trace past partial
20215 specializations, however. For example, given in addition:
20217 template <class T> struct S<T*> { template <class U> void f(U); };
20219 if TMPL is `template <class U> void S<int*>::f(U)' this will return
20220 `template <class T> template <class U> S<T*>::f(U)'. */
20222 tree
20224 {
20226 {
20229 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
20230 template friend, or a FIELD_DECL for a capture pack. */
20233 }
20235 /* Look for more and more general templates. */
20237 {
20238 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
20239 (See cp-tree.h for details.) */
20248 /* Stop if we run into an explicitly specialized class template. */
20255 }
20258 }
20260 /* Return the most specialized of the template partial specializations
20261 which can produce TARGET, a specialization of some class or variable
20262 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
20263 a TEMPLATE_DECL node corresponding to the partial specialization, while
20264 the TREE_PURPOSE is the set of template arguments that must be
20265 substituted into the template pattern in order to generate TARGET.
20267 If the choice of partial specialization is ambiguous, a diagnostic
20268 is issued, and the error_mark_node is returned. If there are no
20269 partial specializations matching TARGET, then NULL_TREE is
20270 returned, indicating that the primary template should be used. */
20272 static tree
20274 {
20276 tree t;
20277 tree champ;
20284 {
20288 }
20290 {
20293 }
20295 {
20299 }
20300 else
20305 /* For determining which partial specialization to use, only the
20306 innermost args are interesting. */
20308 {
20311 }
20314 {
20315 tree partial_spec_args;
20316 tree spec_args;
20324 {
20325 /* Discard the outer levels of args, and then substitute in the
20326 template args from the enclosing class. */
20328 partial_spec_args = tsubst_template_args
20331 /* And the same for the partial specialization TEMPLATE_DECL. */
20333 }
20335 partial_spec_args =
20337 partial_spec_args,
20351 partial_spec_args,
20352 args);
20354 {
20358 /* Keep the candidate only if the constraints are satisfied,
20359 or if we're not compiling with concepts. */
20362 {
20365 }
20366 }
20367 }
20377 {
20380 ;
20381 else
20382 {
20384 {
20387 {
20390 }
20391 }
20393 }
20394 }
20398 {
20401 {
20404 }
20405 }
20408 {
20415 else
20419 {
20424 }
20427 }
20430 }
20432 /* Explicitly instantiate DECL. */
20434 void
20436 {
20441 /* An error occurred, for which grokdeclarator has already issued
20442 an appropriate message. */
20445 {
20448 }
20454 {
20455 /* There is an asymmetry here in the way VAR_DECLs and
20456 FUNCTION_DECLs are handled by grokdeclarator. In the case of
20457 the latter, the DECL we get back will be marked as a
20458 template instantiation, and the appropriate
20459 DECL_TEMPLATE_INFO will be set up. This does not happen for
20460 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
20461 should handle VAR_DECLs as it currently handles
20462 FUNCTION_DECLs. */
20464 {
20467 }
20470 {
20473 }
20475 {
20480 }
20481 }
20483 {
20486 }
20487 else
20490 /* Check for various error cases. Note that if the explicit
20491 instantiation is valid the RESULT will currently be marked as an
20492 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
20493 until we get here. */
20496 {
20497 /* DR 259 [temp.spec].
20499 Both an explicit instantiation and a declaration of an explicit
20500 specialization shall not appear in a program unless the explicit
20501 instantiation follows a declaration of the explicit specialization.
20503 For a given set of template parameters, if an explicit
20504 instantiation of a template appears after a declaration of an
20505 explicit specialization for that template, the explicit
20506 instantiation has no effect. */
20508 }
20510 {
20511 /* [temp.spec]
20513 No program shall explicitly instantiate any template more
20514 than once.
20516 We check DECL_NOT_REALLY_EXTERN so as not to complain when
20517 the first instantiation was `extern' and the second is not,
20518 and EXTERN_P for the opposite case. */
20521 /* If an "extern" explicit instantiation follows an ordinary
20522 explicit instantiation, the template is instantiated. */
20525 }
20527 {
20530 }
20532 {
20535 }
20538 ;
20540 {
20543 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
20546 }
20547 else
20555 }
20557 static void
20559 {
20565 {
20568 }
20569 }
20571 /* Called from do_type_instantiation through binding_table_foreach to
20572 do recursive instantiation for the type bound in ENTRY. */
20573 static void
20575 {
20581 }
20583 /* Called from do_type_instantiation to instantiate a member
20584 (a member function or a static member variable) of an
20585 explicitly instantiated class template. */
20586 static void
20588 {
20593 }
20595 /* Perform an explicit instantiation of template class T. STORAGE, if
20596 non-null, is the RID for extern, inline or static. COMPLAIN is
20597 nonzero if this is called from the parser, zero if called recursively,
20598 since the standard is unclear (as detailed below). */
20600 void
20602 {
20612 {
20613 tree tmpl =
20617 else
20620 }
20625 {
20628 t);
20630 }
20633 {
20635 {
20637 {
20640 "ISO C++ 1998 forbids the use of %<extern%> on "
20642 }
20643 else
20645 "ISO C++ forbids the use of %qE"
20647 }
20655 else
20656 {
20658 storage);
20660 }
20661 }
20664 {
20665 /* DR 259 [temp.spec].
20667 Both an explicit instantiation and a declaration of an explicit
20668 specialization shall not appear in a program unless the explicit
20669 instantiation follows a declaration of the explicit specialization.
20671 For a given set of template parameters, if an explicit
20672 instantiation of a template appears after a declaration of an
20673 explicit specialization for that template, the explicit
20674 instantiation has no effect. */
20676 }
20678 {
20679 /* [temp.spec]
20681 No program shall explicitly instantiate any template more
20682 than once.
20684 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
20685 instantiation was `extern'. If EXTERN_P then the second is.
20686 These cases are OK. */
20693 /* If we've already instantiated the template, just return now. */
20696 }
20704 {
20705 tree tmp;
20707 /* In contrast to implicit instantiation, where only the
20708 declarations, and not the definitions, of members are
20709 instantiated, we have here:
20711 [temp.explicit]
20713 The explicit instantiation of a class template specialization
20714 implies the instantiation of all of its members not
20715 previously explicitly specialized in the translation unit
20716 containing the explicit instantiation.
20718 Of course, we can't instantiate member template classes, since
20719 we don't have any arguments for them. Note that the standard
20720 is unclear on whether the instantiation of the members are
20721 *explicit* instantiations or not. However, the most natural
20722 interpretation is that it should be an explicit instantiation. */
20737 }
20738 }
20740 /* Given a function DECL, which is a specialization of TMPL, modify
20741 DECL to be a re-instantiation of TMPL with the same template
20742 arguments. TMPL should be the template into which tsubst'ing
20743 should occur for DECL, not the most general template.
20745 One reason for doing this is a scenario like this:
20747 template <class T>
20748 void f(const T&, int i);
20750 void g() { f(3, 7); }
20752 template <class T>
20753 void f(const T& t, const int i) { }
20755 Note that when the template is first instantiated, with
20756 instantiate_template, the resulting DECL will have no name for the
20757 first parameter, and the wrong type for the second. So, when we go
20758 to instantiate the DECL, we regenerate it. */
20760 static void
20762 {
20763 /* The arguments used to instantiate DECL, from the most general
20764 template. */
20765 tree args;
20766 tree code_pattern;
20771 /* Make sure that we can see identifiers, and compute access
20772 correctly. */
20776 {
20777 tree decl_parm;
20778 tree pattern_parm;
20779 tree specs;
20793 specs);
20795 /* Merge parameter declarations. */
20798 pattern_parm
20802 {
20803 tree parm_type;
20804 tree attributes;
20809 NULL_TREE);
20815 {
20818 }
20821 }
20822 /* Merge any parameters that match with the function parameter
20823 pack. */
20825 {
20827 tree expanded_types;
20828 /* Expand the TYPE_PACK_EXPANSION that provides the types for
20829 the parameters in this function parameter pack. */
20834 {
20835 tree parm_type;
20836 tree attributes;
20839 /* Rename the parameter to include the index. */
20848 {
20851 }
20853 }
20854 }
20855 /* Merge additional specifiers from the CODE_PATTERN. */
20859 }
20861 {
20869 }
20870 else
20874 }
20876 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
20877 substituted to get DECL. */
20879 tree
20881 {
20884 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
20885 for the instantiation. This is not always the most general
20886 template. Consider, for example:
20888 template <class T>
20889 struct S { template <class U> void f();
20890 template <> void f<int>(); };
20892 and an instantiation of S<double>::f<int>. We want TD to be the
20893 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
20895 more general template. */
20897 /* We must also deal with friend templates. Given:
20899 template <class T> struct S {
20900 template <class U> friend void f() {};
20901 };
20903 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
20904 so far as the language is concerned, but that's still
20905 where we get the pattern for the instantiation from. On
20906 other hand, if the definition comes outside the class, say:
20908 template <class T> struct S {
20909 template <class U> friend void f();
20910 };
20911 template <class U> friend void f() {}
20913 we don't need to look any further. That's what the check for
20914 DECL_INITIAL is for. */
20918 {
20919 /* The present template, TD, should not be a definition. If it
20920 were a definition, we should be using it! Note that we
20921 cannot restructure the loop to just keep going until we find
20922 a template with a definition, since that might go too far if
20923 a specialization was declared, but not defined. */
20925 /* Fetch the more general template. */
20927 }
20930 }
20932 /* Returns true if we need to instantiate this template instance even if we
20933 know we aren't going to emit it. */
20935 bool
20937 {
20938 /* We always instantiate inline functions so that we can inline them. An
20939 explicit instantiation declaration prohibits implicit instantiation of
20940 non-inline functions. With high levels of optimization, we would
20941 normally inline non-inline functions -- but we're not allowed to do
20942 that for "extern template" functions. Therefore, we check
20943 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
20947 /* And we need to instantiate static data members so that
20948 their initializers are available in integral constant
20949 expressions. */
20952 }
20954 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
20955 instantiate it now, modifying TREE_TYPE (fn). */
20957 void
20959 {
20962 /* Don't instantiate a noexcept-specification from template context. */
20977 {
20981 {
20996 }
20997 else
21001 }
21004 {
21007 else
21009 }
21010 }
21012 /* Produce the definition of D, a _DECL generated from a template. If
21013 DEFER_OK is nonzero, then we don't have to actually do the
21014 instantiation now; we just have to do it sometime. Normally it is
21015 an error if this is an explicit instantiation but D is undefined.
21016 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
21017 explicitly instantiated class template. */
21019 tree
21022 {
21024 tree gen_args;
21025 tree args;
21026 tree td;
21027 tree code_pattern;
21028 tree spec;
21029 tree gen_tmpl;
21036 tree fn_context;
21039 /* This function should only be used to instantiate templates for
21040 functions and static member variables. */
21043 /* A concept is never instantiated. */
21046 /* Variables are never deferred; if instantiation is required, they
21047 are instantiated right away. That allows for better code in the
21048 case that an expression refers to the value of the variable --
21049 if the variable has a constant value the referring expression can
21050 take advantage of that fact. */
21055 /* Don't instantiate cloned functions. Instead, instantiate the
21056 functions they cloned. */
21064 /* D has already been instantiated or explicitly specialized, so
21065 there's nothing for us to do here.
21067 It might seem reasonable to check whether or not D is an explicit
21068 instantiation, and, if so, stop here. But when an explicit
21069 instantiation is deferred until the end of the compilation,
21070 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
21071 the instantiation. */
21074 /* Check to see whether we know that this template will be
21075 instantiated in some other file, as with "extern template"
21076 extension. */
21079 /* In general, we do not instantiate such templates. */
21087 /* We should already have the extra args. */
21090 /* And what's in the hash table should match D. */
21094 /* This needs to happen before any tsubsting. */
21100 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
21101 for the instantiation. */
21105 /* We should never be trying to instantiate a member of a class
21106 template or partial specialization. */
21111 /* In the case of a friend template whose definition is provided
21112 outside the class, we may have too many arguments. Drop the
21113 ones we don't need. The same is true for specializations. */
21114 args = get_innermost_template_args
21116 else
21120 {
21125 }
21126 else
21127 {
21130 }
21132 /* We may be in the middle of deferred access check. Disable it now. */
21135 /* Unless an explicit instantiation directive has already determined
21136 the linkage of D, remember that a definition is available for
21137 this entity. */
21147 /* If D is a member of an explicitly instantiated class template,
21148 and no definition is available, treat it like an implicit
21149 instantiation. */
21152 {
21153 /* Leave linkage flags alone on instantiations with anonymous
21154 visibility. */
21156 {
21159 }
21161 }
21163 /* Defer all other templates, unless we have been explicitly
21164 forbidden from doing so. */
21166 template. */
21167 ! pattern_defined
21168 /* If it's OK to postpone instantiation, do so. */
21169 || defer_ok
21170 /* If this is a static data member that will be defined
21171 elsewhere, we don't want to instantiate the entire data
21172 member, but we do want to instantiate the initializer so that
21173 we can substitute that elsewhere. */
21175 /* Handle here a deleted function too, avoid generating
21176 its body (c++/61080). */
21178 {
21179 /* The definition of the static data member is now required so
21180 we must substitute the initializer. */
21184 {
21185 tree ns;
21186 tree init;
21195 args,
21198 /* If instantiating the initializer involved instantiating this
21199 again, don't call cp_finish_decl twice. */
21201 {
21202 /* Make sure the initializer is still constant, in case of
21203 circular dependency (template/instantiate6.C). */
21204 const_init
21208 LOOKUP_ONLYCONVERTING);
21209 }
21213 }
21215 /* We restore the source position here because it's used by
21216 add_pending_template. */
21222 /* [temp.explicit]
21224 The definition of a non-exported function template, a
21225 non-exported member function template, or a non-exported
21226 member function or static data member of a class template
21227 shall be present in every translation unit in which it is
21228 explicitly instantiated. */
21232 /* If we're in unevaluated context, we just wanted to get the
21233 constant value; this isn't an odr use, so don't queue
21234 a full instantiation. */
21237 /* ??? Historically, we have instantiated inline functions, even
21238 when marked as "extern template". */
21242 }
21243 /* Tell the repository that D is available in this translation unit
21244 -- and see if it is supposed to be instantiated here. */
21246 {
21247 /* In a PCH file, despite the fact that the repository hasn't
21248 requested instantiation in the PCH it is still possible that
21249 an instantiation will be required in a file that includes the
21250 PCH. */
21253 /* Instantiate inline functions so that the inliner can do its
21254 job, even though we'll not be emitting a copy of this
21255 function. */
21258 }
21264 else
21265 {
21270 }
21272 /* Mark D as instantiated so that recursive calls to
21273 instantiate_decl do not try to instantiate it again. */
21276 /* Regenerate the declaration in case the template has been modified
21277 by a subsequent redeclaration. */
21280 /* We already set the file and line above. Reset them now in case
21281 they changed as a result of calling regenerate_decl_from_template. */
21285 {
21286 tree init;
21289 /* Clear out DECL_RTL; whatever was there before may not be right
21290 since we've reset the type of the declaration. */
21294 /* The initializer is placed in DECL_INITIAL by
21295 regenerate_decl_from_template so we don't need to
21296 push/pop_access_scope again here. Pull it out so that
21297 cp_finish_decl can process it. */
21302 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
21303 initializer. That function will defer actual emission until
21304 we have a chance to determine linkage. */
21307 /* Enter the scope of D so that access-checking works correctly. */
21320 }
21324 {
21326 tree subst_decl;
21327 tree tmpl_parm;
21328 tree spec_parm;
21331 /* Save away the current list, in case we are instantiating one
21332 template from within the body of another. */
21335 /* Set up the list of local specializations. */
21338 /* Set up context. */
21342 else
21345 /* Some typedefs referenced from within the template code need to be
21346 access checked at template instantiation time, i.e now. These
21347 types were added to the template at parsing time. Let's get those
21348 and perform the access checks then. */
21350 gen_args);
21352 /* Create substitution entries for the parameters. */
21357 {
21361 }
21363 {
21365 {
21368 }
21369 else
21370 {
21371 /* Register the (value) argument pack as a specialization of
21372 TMPL_PARM, then move on. */
21375 }
21376 }
21379 /* Substitute into the body of the function. */
21383 else
21384 {
21389 /* Set the current input_location to the end of the function
21390 so that finish_function knows where we are. */
21391 input_location
21394 /* Remember if we saw an infinite loop in the template. */
21395 current_function_infinite_loop
21397 }
21399 /* We don't need the local specializations any more. */
21403 /* Finish the function. */
21407 else
21408 {
21411 }
21415 }
21417 /* We're not deferring instantiation any more. */
21425 out:
21435 }
21437 /* Run through the list of templates that we wish we could
21438 instantiate, and instantiate any we can. RETRIES is the
21439 number of times we retry pending template instantiation. */
21441 void
21443 {
21447 /* Instantiating templates may trigger vtable generation. This in turn
21448 may require further template instantiations. We place a limit here
21449 to avoid infinite loop. */
21451 {
21455 "template instantiation depth exceeds maximum of %d"
21456 " instantiating %q+D, possibly from virtual table generation"
21460 /* Pretend that we defined it. */
21463 }
21465 do
21466 {
21471 {
21476 {
21477 tree fn;
21480 {
21484 fn;
21492 }
21495 }
21496 else
21497 {
21500 {
21501 instantiation
21507 }
21511 }
21514 /* If INSTANTIATION has been instantiated, then we don't
21515 need to consider it again in the future. */
21517 else
21518 {
21521 }
21524 }
21526 }
21530 }
21532 /* Substitute ARGVEC into T, which is a list of initializers for
21533 either base class or a non-static data member. The TREE_PURPOSEs
21534 are DECLs, and the TREE_VALUEs are the initializer values. Used by
21535 instantiate_decl. */
21537 static tree
21539 {
21543 {
21544 tree decl;
21545 tree init;
21551 {
21552 tree expr;
21553 tree arg;
21555 /* Expand the base class expansion type into separate base
21556 classes. */
21558 tf_warning_or_error,
21559 NULL_TREE);
21563 /* We'll be building separate TREE_LISTs of arguments for
21564 each base. */
21570 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
21571 expand each argument in the TREE_VALUE of t. */
21578 /* VOID_TYPE_NODE is used to indicate
21579 value-initialization. */
21580 {
21583 }
21584 else
21585 {
21586 /* Substitute parameter packs into each argument in the
21587 TREE_LIST. */
21590 {
21591 tree expanded_exprs;
21593 /* Expand the argument. */
21595 expanded_exprs
21597 tf_warning_or_error,
21598 NULL_TREE);
21602 /* Prepend each of the expanded expressions to the
21603 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
21605 {
21610 }
21611 }
21614 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
21615 since we built them backwards. */
21617 {
21620 }
21621 }
21622 }
21625 {
21627 {
21631 }
21632 else
21633 {
21634 tree tmp;
21649 /* If we had an initializer but it instantiated to nothing,
21650 value-initialize the object. This will only occur when
21651 the initializer was a pack expansion where the parameter
21652 packs used in that expansion were of length zero. */
21655 }
21658 {
21662 }
21663 }
21664 }
21666 }
21668 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
21670 static void
21672 {
21677 else
21679 }
21681 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
21682 is the instantiation (which should have been created with
21683 start_enum) and ARGS are the template arguments to use. */
21685 static void
21687 {
21688 tree e;
21694 {
21695 tree value;
21696 tree decl;
21699 /* Note that in a template enum, the TREE_VALUE is the
21700 CONST_DECL, not the corresponding INTEGER_CST. */
21705 /* Give this enumeration constant the correct access. */
21708 /* Actually build the enumerator itself. Here we're assuming that
21709 enumerators can't have dependent attributes. */
21712 }
21722 }
21724 /* DECL is a FUNCTION_DECL that is a template specialization. Return
21725 its type -- but without substituting the innermost set of template
21726 arguments. So, innermost set of template parameters will appear in
21727 the type. */
21729 tree
21731 {
21732 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
21734 }
21736 /* Return truthvalue if we're processing a template different from
21737 the last one involved in diagnostics. */
21738 bool
21740 {
21742 }
21744 /* Remember current template involved in diagnostics. */
21745 void
21747 {
21749 }
21753 {
21755 }
21757 /* Return TRUE if current_function_decl is being instantiated, false
21758 otherwise. */
21760 bool
21762 {
21765 }
21767 /* [temp.param] Check that template non-type parm TYPE is of an allowable
21768 type. Return zero for ok, nonzero for disallowed. Issue error and
21769 warning messages under control of COMPLAIN. */
21771 static int
21773 {
21788 /* A bound template template parm could later be instantiated to have a valid
21789 nontype parm type via an alias template. */
21795 {
21798 else
21800 type);
21801 }
21803 }
21805 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
21806 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
21808 static bool
21810 {
21811 tree scope;
21813 /* [temp.dep.type]
21815 A type is dependent if it is:
21817 -- a template parameter. Template template parameters are types
21818 for us (since TYPE_P holds true for them) so we handle
21819 them here. */
21823 /* -- a qualified-id with a nested-name-specifier which contains a
21824 class-name that names a dependent type or whose unqualified-id
21825 names a dependent type. */
21829 /* An alias template specialization can be dependent even if the
21830 resulting type is not. */
21834 /* -- a cv-qualified type where the cv-unqualified type is
21835 dependent.
21836 No code is necessary for this bullet; the code below handles
21837 cv-qualified types, and we don't want to strip aliases with
21838 TYPE_MAIN_VARIANT because of DR 1558. */
21839 /* -- a compound type constructed from any dependent type. */
21849 {
21850 tree arg_type;
21855 arg_type;
21860 }
21861 /* -- an array type constructed from any dependent type or whose
21862 size is specified by a constant expression that is
21863 value-dependent.
21865 We checked for type- and value-dependence of the bounds in
21866 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
21868 {
21873 }
21875 /* -- a template-id in which either the template name is a template
21876 parameter ... */
21879 /* ... or any of the template arguments is a dependent type or
21880 an expression that is type-dependent or value-dependent. */
21882 && (any_dependent_template_arguments_p
21886 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
21887 dependent; if the argument of the `typeof' expression is not
21888 type-dependent, then it should already been have resolved. */
21894 /* A template argument pack is dependent if any of its packed
21895 arguments are. */
21897 {
21903 }
21905 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
21906 be template parameters. */
21910 /* The standard does not specifically mention types that are local
21911 to template functions or local classes, but they should be
21912 considered dependent too. For example:
21914 template <int I> void f() {
21915 enum E { a = I };
21916 S<sizeof (E)> s;
21917 }
21919 The size of `E' cannot be known until the value of `I' has been
21920 determined. Therefore, `E' must be considered dependent. */
21924 /* Don't use type_dependent_expression_p here, as it can lead
21925 to infinite recursion trying to determine whether a lambda
21926 nested in a lambda is dependent (c++/47687). */
21930 && (any_dependent_template_arguments_p
21934 /* Other types are non-dependent. */
21936 }
21938 /* Returns TRUE if TYPE is dependent, in the sense of
21939 [temp.dep.type]. Note that a NULL type is considered dependent. */
21941 bool
21943 {
21944 /* If there are no template parameters in scope, then there can't be
21945 any dependent types. */
21947 {
21948 /* If we are not processing a template, then nobody should be
21949 providing us with a dependent type. */
21953 }
21955 /* If the type is NULL, we have not computed a type for the entity
21956 in question; in that case, the type is dependent. */
21960 /* Erroneous types can be considered non-dependent. */
21964 /* If we have not already computed the appropriate value for TYPE,
21965 do so now. */
21967 {
21970 }
21973 }
21975 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
21976 lookup. In other words, a dependent type that is not the current
21977 instantiation. */
21979 bool
21981 {
21984 }
21986 /* T is a SCOPE_REF; return whether we need to consider it
21987 instantiation-dependent so that we can check access at instantiation
21988 time even though we know which member it resolves to. */
21990 static bool
21992 {
21998 else
22000 }
22002 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
22003 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
22004 expression. */
22006 /* Note that this predicate is not appropriate for general expressions;
22007 only constant expressions (that satisfy potential_constant_expression)
22008 can be tested for value dependence. */
22010 bool
22012 {
22016 /* A name declared with a dependent type. */
22021 {
22023 /* A name that has not been looked up -- must be dependent. */
22027 /* A non-type template parm. */
22031 /* A non-type template parm. */
22037 /* A constant with literal type and is initialized
22038 with an expression that is value-dependent.
22040 Note that a non-dependent parenthesized initializer will have
22041 already been replaced with its constant value, so if we see
22042 a TREE_LIST it must be dependent. */
22046 /* cp_finish_decl doesn't fold reference initializers. */
22057 /* These expressions are value-dependent if the type to which
22058 the cast occurs is dependent or the expression being casted
22059 is value-dependent. */
22060 {
22066 /* A functional cast has a list of operands. */
22069 {
22070 /* If there are no operands, it must be an expression such
22071 as "int()". This should not happen for aggregate types
22072 because it would form non-constant expressions. */
22077 }
22083 }
22088 /* FALLTHRU */
22091 /* A `sizeof' expression is value-dependent if the operand is
22092 type-dependent or is a pack expansion. */
22101 /* An 'encode' expression is value-dependent if the operand is
22102 type-dependent. */
22111 /* All instantiation-dependent expressions should also be considered
22112 value-dependent. */
22120 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
22121 is value-dependent. */
22122 {
22131 }
22134 {
22138 }
22149 {
22153 }
22156 /* Treat all requires-expressions as value-dependent so
22157 we don't try to fold them. */
22164 {
22171 {
22173 /* In a call to a constexpr member function, look through the
22174 implicit ADDR_EXPR on the object argument so that it doesn't
22175 cause the call to be considered value-dependent. We also
22176 look through it in potential_constant_expression. */
22183 }
22185 }
22188 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
22189 type-dependent. */
22194 {
22196 tree val;
22203 }
22206 /* Treat a GNU statement expression as dependent to avoid crashing
22207 under instantiate_non_dependent_expr; it can't be constant. */
22211 /* A constant expression is value-dependent if any subexpression is
22212 value-dependent. */
22214 {
22221 {
22225 {
22228 /* In some cases, some of the operands may be missing.l
22229 (For example, in the case of PREDECREMENT_EXPR, the
22230 amount to increment by may be missing.) That doesn't
22231 make the expression dependent. */
22234 }
22235 }
22239 }
22241 }
22243 /* The expression is not value-dependent. */
22245 }
22247 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
22248 [temp.dep.expr]. Note that an expression with no type is
22249 considered dependent. Other parts of the compiler arrange for an
22250 expression with type-dependent subexpressions to have no type, so
22251 this function doesn't have to be fully recursive. */
22253 bool
22255 {
22262 /* An unresolved name is always dependent. */
22268 /* A fold expression is type-dependent. */
22275 /* Some expression forms are never type-dependent. */
22289 /* The types of these expressions depends only on the type to which
22290 the cast occurs. */
22299 /* The types of these expressions depends only on the type created
22300 by the expression. */
22303 {
22304 /* For NEW_EXPR tree nodes created inside a template, either
22305 the object type itself or a TREE_LIST may appear as the
22306 operand 1. */
22309 /* This is an array type. We need to check array dimensions
22310 as well. */
22312 || value_dependent_expression_p
22314 else
22316 }
22319 {
22323 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
22324 contains an identifier associated by name lookup with one or more
22325 declarations declared with a dependent type, or...a
22326 nested-name-specifier or qualified-id that names a member of an
22327 unknown specialization. */
22330 }
22335 && (any_dependent_template_arguments_p
22347 {
22348 tree elt;
22352 {
22355 }
22357 }
22359 /* A static data member of the current instantiation with incomplete
22360 array type is type-dependent, as the definition and specializations
22361 can have different bounds. */
22368 /* An array of unknown bound depending on a variadic parameter, eg:
22370 template<typename... Args>
22371 void foo (Args... args)
22372 {
22373 int arr[] = { args... };
22374 }
22376 template<int... vals>
22377 void bar ()
22378 {
22379 int arr[] = { vals... };
22380 }
22382 If the array has no length and has an initializer, it must be that
22383 we couldn't determine its length in cp_complete_array_type because
22384 it is dependent. */
22391 /* A variable template specialization is type-dependent if it has any
22392 dependent template arguments. */
22399 /* Always dependent, on the number of arguments if nothing else. */
22404 {
22409 {
22415 }
22416 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
22421 {
22426 }
22429 {
22436 }
22442 {
22446 }
22448 }
22453 }
22455 /* walk_tree callback function for instantiation_dependent_expression_p,
22456 below. Returns non-zero if a dependent subexpression is found. */
22458 static tree
22461 {
22463 {
22464 /* We don't have to worry about decltype currently because decltype
22465 of an instantiation-dependent expr is a dependent type. This
22466 might change depending on the resolution of DR 1172. */
22469 }
22472 {
22473 /* Don't treat an argument list as dependent just because it has no
22474 TREE_TYPE. */
22481 /* A constant with a dependent initializer is dependent. */
22489 /* Handle expressions with type operands. */
22494 {
22499 {
22502 else
22503 {
22506 }
22507 }
22509 }
22519 /* In a template, finish_class_member_access_expr creates a
22520 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
22521 type-dependent, so that we can check access control at
22522 instantiation time (PR 42277). See also Core issue 1273. */
22529 else
22532 /* Treat statement-expressions as dependent. */
22536 /* Treat requires-expressions as dependent. */
22541 /* Treat calls to function concepts as dependent. */
22547 /* And variable concepts. */
22554 }
22558 else
22560 }
22562 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
22563 sense defined by the ABI:
22565 "An expression is instantiation-dependent if it is type-dependent
22566 or value-dependent, or it has a subexpression that is type-dependent
22567 or value-dependent." */
22569 bool
22571 {
22572 tree result;
22583 }
22585 /* Like type_dependent_expression_p, but it also works while not processing
22586 a template definition, i.e. during substitution or mangling. */
22588 bool
22590 {
22596 }
22598 /* Returns TRUE if ARGS contains a type-dependent expression. */
22600 bool
22602 {
22604 tree arg;
22607 {
22610 }
22612 }
22614 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
22615 expressions) contains any type-dependent expressions. */
22617 bool
22619 {
22625 }
22627 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
22628 expressions) contains any value-dependent expressions. */
22630 bool
22632 {
22638 }
22640 /* Returns TRUE if the ARG (a template argument) is dependent. */
22642 bool
22644 {
22648 /* Assume a template argument that was wrongly written by the user
22649 is dependent. This is consistent with what
22650 any_dependent_template_arguments_p [that calls this function]
22651 does. */
22662 {
22666 {
22669 }
22672 }
22675 else
22678 }
22680 /* Returns true if ARGS (a collection of template arguments) contains
22681 any types that require structural equality testing. */
22683 bool
22685 {
22695 {
22698 {
22704 {
22705 /* Look inside the argument pack. */
22708 }
22711 {
22724 }
22725 }
22726 }
22729 }
22731 /* Returns true if ARGS (a collection of template arguments) contains
22732 any dependent arguments. */
22734 bool
22736 {
22746 {
22751 }
22754 }
22756 /* Returns TRUE if the template TMPL is dependent. */
22758 bool
22760 {
22762 {
22764 {
22768 }
22770 }
22772 /* Template template parameters are dependent. */
22776 /* So are names that have not been looked up. */
22779 /* So are member templates of dependent classes. */
22783 }
22785 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
22787 bool
22789 {
22792 }
22794 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
22795 is dependent. */
22797 bool
22799 {
22806 {
22827 {
22831 }
22835 {
22839 {
22844 }
22845 }
22846 }
22849 }
22851 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
22852 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
22853 no such TYPE can be found. Note that this function peers inside
22854 uninstantiated templates and therefore should be used only in
22855 extremely limited situations. ONLY_CURRENT_P restricts this
22856 peering to the currently open classes hierarchy (which is required
22857 when comparing types). */
22859 tree
22861 {
22862 tree scope;
22863 tree name;
22864 tree decl;
22866 tree pushed_scope;
22867 tree result;
22872 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
22873 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
22874 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
22875 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
22876 identifier of the TYPENAME_TYPE anymore.
22877 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
22878 TYPENAME_TYPE instead, we avoid messing up with a possible
22879 typedef variant case. */
22882 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
22883 it first before we can figure out what NAME refers to. */
22885 {
22887 /* Given a class template A with a dependent base with nested type C,
22888 typedef typename A::C::C C will land us here, as trying to resolve
22889 the initial A::C leads to the local C typedef, which leads back to
22890 A::C::C. So we break the recursion now. */
22892 else
22894 }
22895 /* If we don't know what SCOPE refers to, then we cannot resolve the
22896 TYPENAME_TYPE. */
22899 /* If the SCOPE is a template type parameter, we have no way of
22900 resolving the name. */
22903 /* If the SCOPE is not the current instantiation, there's no reason
22904 to look inside it. */
22907 /* If this is a typedef, we don't want to look inside (c++/11987). */
22910 /* If SCOPE isn't the template itself, it will not have a valid
22911 TYPE_FIELDS list. */
22914 /* scope is either the template itself or a compatible instantiation
22915 like X<T>, so look up the name in the original template. */
22917 else
22918 /* scope is a partial instantiation, so we can't do the lookup or we
22919 will lose the template arguments. */
22921 /* Enter the SCOPE so that name lookup will be resolved as if we
22922 were in the class definition. In particular, SCOPE will no
22923 longer be considered a dependent type. */
22925 /* Look up the declaration. */
22927 tf_warning_or_error);
22931 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
22932 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
22937 {
22941 }
22944 {
22945 tree tmpl;
22946 tree args;
22947 /* Obtain the template and the arguments. */
22950 /* Instantiate the template. */
22956 }
22958 /* Leave the SCOPE. */
22962 /* If we failed to resolve it, return the original typename. */
22966 /* If lookup found a typename type, resolve that too. */
22968 {
22969 /* Ill-formed programs can cause infinite recursion here, so we
22970 must catch that. */
22974 }
22976 /* Qualify the resulting type. */
22982 }
22984 /* EXPR is an expression which is not type-dependent. Return a proxy
22985 for EXPR that can be used to compute the types of larger
22986 expressions containing EXPR. */
22988 tree
22990 {
22991 tree inner_expr;
22993 #ifdef ENABLE_CHECKING
22994 /* Try to get a constant value for all non-dependent expressions in
22995 order to expose bugs in *_dependent_expression_p and constexpr. */
22998 #endif
23000 /* Preserve OVERLOADs; the functions must be available to resolve
23001 types. */
23012 /* There is no need to return a proxy for a variable. */
23015 /* Preserve string constants; conversions from string constants to
23016 "char *" are allowed, even though normally a "const char *"
23017 cannot be used to initialize a "char *". */
23020 /* Preserve void and arithmetic constants, as an optimization -- there is no
23021 reason to create a new node. */
23026 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
23027 There is at least one place where we want to know that a
23028 particular expression is a throw-expression: when checking a ?:
23029 expression, there are special rules if the second or third
23030 argument is a throw-expression. */
23034 /* Don't wrap an initializer list, we need to be able to look inside. */
23038 /* Don't wrap a dummy object, we need to be able to test for it. */
23057 /* If the type is unknown, it can't really be non-dependent */
23060 /* Otherwise, build a NON_DEPENDENT_EXPR. */
23062 }
23064 /* ARGS is a vector of expressions as arguments to a function call.
23065 Replace the arguments with equivalent non-dependent expressions.
23066 This modifies ARGS in place. */
23068 void
23070 {
23072 tree arg;
23075 {
23079 }
23080 }
23082 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
23083 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
23084 parms. */
23086 static tree
23088 {
23101 }
23103 tree
23105 {
23107 }
23109 tree
23111 {
23113 }
23115 /* Given type ARG, return std::initializer_list<ARG>. */
23117 static tree
23119 {
23120 tree std_init_list = namespace_binding
23122 tree argvec;
23124 {
23128 }
23133 }
23135 /* Replace auto in TYPE with std::initializer_list<auto>. */
23137 static tree
23139 {
23146 }
23148 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23149 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
23151 tree
23153 {
23155 tf_warning_or_error,
23156 adc_unspecified);
23157 }
23159 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23160 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
23161 The CONTEXT determines the context in which auto deduction is performed
23162 and is used to control error diagnostics. */
23164 tree
23167 {
23168 tree targs;
23174 /* Defining a subset of type-dependent expressions that we can deduce
23175 from ahead of time isn't worth the trouble. */
23178 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
23179 with either a new invented type template parameter U or, if the
23180 initializer is a braced-init-list (8.5.4), with
23181 std::initializer_list<U>. */
23183 {
23188 else
23189 {
23191 {
23195 "for deduction to %<std::initializer_list%>, use copy-"
23197 }
23199 }
23200 }
23206 {
23212 {
23216 }
23217 }
23218 else
23219 {
23230 {
23232 /* Try again at instantiation time. */
23236 /* If type is error_mark_node a diagnostic must have been
23237 emitted by now. Also, having a mention to '<type error>'
23238 in the diagnostic is not really useful to the user. */
23239 {
23243 else
23245 }
23247 }
23248 }
23250 /* If the list of declarators contains more than one declarator, the type
23251 of each declared variable is determined as described above. If the
23252 type deduced for the template parameter U is not the same in each
23253 deduction, the program is ill-formed. */
23256 {
23262 else
23266 }
23270 /* Check any placeholder constraints against the deduced type. */
23273 {
23274 /* Use the deduced type to check the associated constraints. */
23276 {
23278 {
23280 {
23296 }
23298 }
23300 }
23301 }
23306 }
23308 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
23309 result. */
23311 tree
23313 {
23315 {
23321 /* In an abbreviated function template we didn't know we were dealing
23322 with a function template when we saw the auto return type, so update
23323 it to have the correct level. */
23325 }
23327 }
23329 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
23330 'decltype(auto)'. */
23332 bool
23334 {
23339 else
23341 }
23343 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
23344 a use of `auto'. Returns NULL_TREE otherwise. */
23346 tree
23348 {
23350 }
23352 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
23353 'decltype(auto)' or a concept. */
23355 bool
23357 {
23359 }
23361 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
23362 a concept identifier) iff TYPE contains a use of a generic type. Returns
23363 NULL_TREE otherwise. */
23365 tree
23367 {
23369 }
23372 /* For a given template T, return the vector of typedefs referenced
23373 in T for which access check is needed at T instantiation time.
23374 T is either a FUNCTION_DECL or a RECORD_TYPE.
23375 Those typedefs were added to T by the function
23376 append_type_to_template_for_access_check. */
23380 {
23381 tree ti;
23392 {
23397 }
23400 }
23402 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
23403 tied to T. That list of typedefs will be access checked at
23404 T instantiation time.
23405 T is either a FUNCTION_DECL or a RECORD_TYPE.
23406 TYPE_DECL is a TYPE_DECL node representing a typedef.
23407 SCOPE is the scope through which TYPE_DECL is accessed.
23408 LOCATION is the location of the usage point of TYPE_DECL.
23410 This function is a subroutine of
23411 append_type_to_template_for_access_check. */
23413 static void
23415 tree type_decl,
23416 tree scope,
23417 location_t location)
23418 {
23419 qualified_typedef_usage_t typedef_usage;
23420 tree ti;
23427 && type_decl
23441 }
23443 /* Append TYPE_DECL to the template TEMPL.
23444 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
23445 At TEMPL instanciation time, TYPE_DECL will be checked to see
23446 if it can be accessed through SCOPE.
23447 LOCATION is the location of the usage point of TYPE_DECL.
23449 e.g. consider the following code snippet:
23451 class C
23452 {
23453 typedef int myint;
23454 };
23456 template<class U> struct S
23457 {
23458 C::myint mi; // <-- usage point of the typedef C::myint
23459 };
23461 S<char> s;
23463 At S<char> instantiation time, we need to check the access of C::myint
23464 In other words, we need to check the access of the myint typedef through
23465 the C scope. For that purpose, this function will add the myint typedef
23466 and the scope C through which its being accessed to a list of typedefs
23467 tied to the template S. That list will be walked at template instantiation
23468 time and access check performed on each typedefs it contains.
23469 Note that this particular code snippet should yield an error because
23470 myint is private to C. */
23472 void
23474 tree type_decl,
23475 tree scope,
23476 location_t location)
23477 {
23483 /* Make sure we don't append the type to the template twice. */
23490 }
23492 /* Convert the generic type parameters in PARM that match the types given in the
23493 range [START_IDX, END_IDX) from the current_template_parms into generic type
23494 packs. */
23496 tree
23498 {
23509 {
23510 /* Create a distinct parameter pack type from the current parm and add it
23511 to the replacement args to tsubst below into the generic function
23512 parameter. */
23527 }
23533 /* If there are more levels then build up the replacement with the outer
23534 template parms. */
23538 replacement);
23541 }
23543 /* Entries in the decl_constraint hash table. */
23545 {
23546 tree decl;
23547 tree ci;
23548 };
23550 /* Hashing function and equality for constraint entries. */
23552 {
23554 {
23556 }
23559 {
23561 }
23562 };
23564 /* A mapping from declarations to constraint information. Note that
23565 both templates and their underlying declarations are mapped to the
23566 same constraint information.
23568 FIXME: This is defined in pt.c because garbage collection
23569 code is not being generated for constraint.cc. */
23573 /* Returns true iff cinfo contains a valid set of constraints.
23574 This is the case when the associated requirements have been
23575 successfully decomposed into lists of atomic constraints.
23576 That is, when the saved assumptions are not error_mark_node. */
23578 bool
23580 {
23583 }
23585 /* Returns the template constraints of declaration T. If T is not
23586 constrained, return NULL_TREE. Note that T must be non-null. */
23588 tree
23590 {
23598 else
23600 }
23602 /* Associate the given constraint information CI with the declaration
23603 T. If T is a template, then the constraints are associated with
23604 its underlying declaration. Don't build associations if CI is
23605 NULL_TREE. */
23607 void
23609 {
23621 }
23623 /* Remove the associated constraints of the declaration T. */
23625 void
23627 {
23636 }
23638 /* Set up the hash table for constraint association. */
23640 void
23642 {
23644 }
23646 /* Set up the hash tables for template instantiations. */
23648 void
23650 {
23653 }
23655 /* Print stats about the template hash tables for -fstats. */
23657 void
23659 {
23668 }